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Sample records for cerium-doped yttrium pyrosilicate

  1. Synthesis of Cerium-Doped Titania Nanoparticles and Nanotubes.

    Science.gov (United States)

    Cao, Wei; Suzuki, Takuya; Elsayed-Ali, Hani E; Abdel-Fattah, Tarek M

    2015-03-01

    Cerium-doped titania nanoparticles and nanotubes were synthesized via hydrothermal processes. X-Ray Diffraction revealed that cerium-doped titania nanoparticles have an anatase crystal structure, while cerium-doped titania nanotubes have an H2Ti3O7-type structure. Scanning electron microscopy and high resolution transmission electron microscopy showed that both types of titania are well crystallized with relatively uniform size distribution. The photocatalytic degradation of methylthioninium chloride known as methylene blue dye was tested and both cerium-doped titania nanoparticles and nanotubes. The preliminary photocatalytic degradation of Methylene Blue data showed significantly improved visible light photocatalytic activities as compared to commercial titania powders.

  2. Structural, optical and photocatalytic activity of cerium doped zinc aluminate

    Science.gov (United States)

    Sumathi, Shanmugam; Kavipriya, A.

    2017-03-01

    Zinc aluminate and cerium-doped zinc aluminate nanoparticles are synthesised by co-precipitation method. Ammonium hydroxide is used as a precipitating agent. The synthesised compounds are characterised by powder X-ray diffraction (XRD), Fourier transform Infrared spectroscopy (FT-IR), Ultraviolet diffuse reflectance spectroscopy (UV-DRS), Thermogravimetric analysis (TGA), Scanning electron microscopy (SEM) and Surface area measurements. The photocatalytic activity of zinc aluminate and cerium doped zinc aluminate nanoparticles are studied under the UV light and visible light taking methylene blue as a model pollutant. The amount of catalyst, concentration of dye solution and time are optimised under UV-light. Degradation of methylene blue under the UV-light is found to be 99% in 20 min with 10 mg of cerium doped catalyst. Compared to visible light degradation, the degradation of dye under UV-light is higher. Cerium doping in zinc aluminate (ZnAl2O4:Ce3+) increased the photocatalytic activity of zinc aluminate.

  3. Growth of bulk gadolinium pyrosilicate single crystals for scintillators

    Science.gov (United States)

    Gerasymov, I.; Sidletskiy, O.; Neicheva, S.; Grinyov, B.; Baumer, V.; Galenin, E.; Katrunov, K.; Tkachenko, S.; Voloshina, O.; Zhukov, A.

    2011-03-01

    Ce, Pr, and La-doped gadolinium pyrosilicate Gd2Si2O7 (GPS) single crystals were grown by the Czochralski and Top Seeded Solution Growth (TSSG) techniques for the first time. Formation conditions of different pyrosilicate phases were determined. X-ray luminescence integral intensity of Ce-doped GPS is about one order of magnitude higher in comparison with gadolinium oxyorthosilicate Gd2SiO5:Ce (GSO:Ce). All samples demonstrate temperature stability of luminescence yield up to 400 K.

  4. Room-temperature scintillation properties of cerium-doped REOX (RE=Y, La, Gd, and Lu; X=F, Cl, Br, and I)

    Energy Technology Data Exchange (ETDEWEB)

    Eagleman, Yetta; Bourret-Courchesne, Edith; Derenzo, Stephen

    2010-12-10

    The scintillation properties of cerium-doped oxyhalides following the general formula REOX (RE=Y, La, Gd, and Lu; X=F, Cl, Br, and I) are reported. These materials were synthesized under dry conditions as microcrystalline powders from conventional solid state reactions. The room temperature X-ray excited emission and scintillation decay curves were measured and analyzed for each material. Additionally, the hygroscopic nature of the oxychlorides and oxybromides was compared to that of their corresponding rare earth halides. The yttrium, lanthanum, and gadolinium oxychlorides, and all of the oxybromides and oxyiodides are found to be activated by Ce{sup 3+}. GdOBr doped with 0.5% Ce{sup 3+} has the highest light output with a relative luminosity of about one-half that of LaBr{sub 3}: Ce{sup 3+}. It displays a single exponential decay of 30 ns.

  5. Structural and luminescent studies on nanosized cerium doped strontium barium niobate

    Science.gov (United States)

    John, Nuja; Nandakumar, K.

    2017-06-01

    The nanosized cerium doped Strontium Barium Niobate ceramic powder system have been synthesized by sol-gel technique. The X-ray diffraction measurement confirmed the structure of cerium doped Strontium Barium Niobate ceramic powder system. The absorption peaks were analysed by FTIR spectroscopy. Particle morphology and size of the powder were examined using SEM and TEM. Crystal quality and structure were also examined by micro raman spectra. The transmission electron microscopy image of cerium doped Strontium Barium Niobate nano powder system consist of particles with average size of 20 nm. A band gap of the system was measured by optical absorption spectra. Photoluminescence data were recorded at room temperature. The emission peaks were detected under excitation at 305 nm wavelength. The peaks are assigned to the cerium electron transition from lowest 5d level to 2F5/2 and 2F7/2 of 4f, respectively. The decay time were also measured for cerium doped Strontium Barium Niobate powder system.

  6. Magnetic hysteresis of cerium doped bismuth ferrite thin films

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-15

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

  7. Structural, topographical and electrical properties of cerium doped strontium barium niobate (Ce:SBN60) ceramics

    Science.gov (United States)

    Raj, S. Gokul; Mathivanan, V.; Kumar, G. Ramesh; Yathavan, S.; Mohan, R.

    2016-05-01

    Tungsten bronze type cerium doped strontium barium niobate (Ce:SBN - Sr0.6B0.4Nb2O6) ceramics were synthesized by solid state process. Cerium was used as dopant to improve its electrical properties. Influence of Ce+ ions on the photoluminescence properties was investigated in detail. The grain size topographical behavior of SBN powders and their associated abnormal grain growth (AGG) were completely analyzed through SEM studies. Finally dielectric, measurement discusses about the broad phase transition observed due to cerium dopant The results were discussed in detail.

  8. Structural, topographical and electrical properties of cerium doped strontium barium niobate (Ce:SBN60) ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Raj, S. Gokul [Department of Physics, C. Kandaswami Naidu College For Men (CKNC), Annanagar, Chennai-600102 (India); Mathivanan, V.; Mohan, R. [Department of Physics, Presidency College, Chennai – 600005 (India); Kumar, G. Ramesh, E-mail: rameshvandhai@gmail.com; Yathavan, S. [Department of Physics, University College of Engineering Arni, Anna University Chennai, Arni-632317 (India)

    2016-05-06

    Tungsten bronze type cerium doped strontium barium niobate (Ce:SBN - Sr{sub 0.6}B{sub 0.4}Nb{sub 2}O{sub 6}) ceramics were synthesized by solid state process. Cerium was used as dopant to improve its electrical properties. Influence of Ce{sup +} ions on the photoluminescence properties was investigated in detail. The grain size topographical behavior of SBN powders and their associated abnormal grain growth (AGG) were completely analyzed through SEM studies. Finally dielectric, measurement discusses about the broad phase transition observed due to cerium dopant The results were discussed in detail.

  9. ARTICLES: Photoinduced light scattering in cerium-doped barium strontium niobate crystals

    Science.gov (United States)

    Voronov, Valerii V.; Dorosh, I. R.; Kuz'minov, Yu S.; Tkachenko, N. V.

    1980-11-01

    Photoinduced light scattering was observed in cerium-doped (SrxBa1-x)1-y(Nb2O6)y crystals having the composition x = 0.61, y = 0.4993. It was found that this effect is due to holographic amplification of light scattered by crystal defects. An analysis is made of static and dynamic characteristics of self-amplification of scattered light in the crystals. A theoretical model of the process is constructed assuming that the hologram recording process is of the diffusion type. Theoretical results are compared with the experiment.

  10. Photoinduced light scattering in cerium-doped barium strontium niobate crystals

    Science.gov (United States)

    Voronov, V. V.; Dorosh, I. R.; Kuz'minov, Yu. S.; Tkachenko, N. V.

    Photoinduced light scattering was observed in cerium-doped (Srx Ba1-x)1-y(Nb2O6)y crystals having the composition x = 0.61, y = 0.4993. It was found that this effect is due to holographic amplification of light scattered by crystal defects. An analysis is made of static and dynamic characteristics of self-amplification of scattered light in the crystals. A theoretical model of the process is constructed assuming that the hologram recording process is of the diffusion type. Theoretical results are compared with the experiment.

  11. Synthesis and Characterization of Cerium Doped Titanium Catalyst for the Degradation of Nitrobenzene Using Visible Light

    Directory of Open Access Journals (Sweden)

    Padmini Ellappan

    2014-01-01

    Full Text Available Cerium doped catalyst was synthesized using Titanium isopropoxide as the Titanium source. The metal doped nanoparticles semiconductor catalyst was prepared by sol-sol method with the sol of Cerium. The synthesized catalyst samples were characterized by powder X-ray diffraction, BET surface area, thermogravimetric analysis (TGA, scanning electron microscopy (SEM, and UV-vis diffuse reflectance measurements (DRS and compared with undoped TiO2 catalyst. The photocatalytic activity of the sample was investigated for the decomposition of nitrobenzene (NB using visible light as the artificial light source. Cerium doped catalyst was found to have better degradation of nitrobenzene owing to its shift in the band gap from UV to visible region as compared to undoped TiO2 catalyst. The operational parameters were optimized with catalyst dosage of 0.1 g L−1, pH of 9, and light intensity of 500 W. The degradation mechanism followed the Langmuir Hinshelwood kinetic model with the rate constant depending nonlinearly on the operational parameters as given by the relationship Kapp (theoretical = 2.29 * 10−4 * Intensity0.584 * Concentration−0.230 * Dosage0.425 * pH0.336.

  12. Catalytic activity of cerium-doped Ru/Al2O3 during ozonation of dimethyl phthalate

    Institute of Scientific and Technical Information of China (English)

    Yunrui ZHOU; Wanpeng ZHU; Xun CHEN

    2008-01-01

    In this paper, factors influencing the mineraliza-tion of dimethyl phthalate (DMP) during catalytic ozona-tion with a cerium-doped Ru/Al2O3 catalyst were studied. The catalytic contribution was calculated through the results of a companrison experiment. It showed that doping cerium significantly enhanced catalytic activity. The total organic carbon (TOC) removal over the doped catalyst at 100 rain reached 75.1%, 61.3% using Ru/Al2O3 catalyst and only 14.0% using ozone alone. Catalytic activity reached the maximum when 0.2% of ruthenium and 1.0% of cerium'were simultaneously loaded onto Al2O3 support. Results of experiments on oxidation by ozone alone, adsorption of the catalyst, Ce ion's and heterogeneous catalytic ozonation confirmed that the contribution of het-erogeneous catalytic ozonation was about 50%, which showed the obvious effect of Ru-Ce/Al2O3 on catalytic activity.

  13. Single crystal fiber growth of cerium doped strontium yttrate, SrY2O4:Ce3+

    Science.gov (United States)

    Philippen, J.; Guguschev, C.; Klimm, D.

    2017-02-01

    First single crystal fibers of cerium doped strontium yttrate were fabricated using the laser-heated pedestal growth technique. Through thermodynamic equilibrium calculations and by high-temperature mass spectrometry suitable growth conditions could be determined. The atmosphere played an important role during crystallization. It affected the composition shift, on the one hand, and the valence state of cerium, on the other hand. These dependencies can be explained by combining X-ray diffraction, elemental analysis, and optical spectroscopy. Crystallization in slightly reducing nitrogen atmosphere proved to be a reasonable choice, because evaporation is suppressed and trivalent cerium is stabilized. Strong green emission that depends on the oxygen fugacity during crystallization could be excited using UV light. Optical properties of SrY2O4:Ce3+ were measured for the first time.

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

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

    2015-06-01

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

  15. Synthesis and Characterization of Cerium-Doped Lutetium Aluminum Garnet Phosphors by Nitrate-citrate Sol-Gel Combustion Process

    Institute of Scientific and Technical Information of China (English)

    Li Huili; Liu Xuejian; Zhang Qitu; Huang Liping

    2007-01-01

    Nanosized cerium-doped lutetium aluminum garnet (LuAG:Ce) phosphors were prepared by nitrate-citrate sol-gel combustion process using 1:1 ratio of the citrate:nitrate. The prepared LuAG:Ce phosphors were characterized by XRD, TEM, photoluminescence and radioluminescence spectra excited by UV and X-ray, respectively. The purified crystalline phase of LuAG:Ce was obtained at 900 ℃ by directly crystallizing from amorphous materials. The resultant LuAG:Ce phosphors were uniform and had good dispersivity with an average particle size of about 30 nm. Both photoluminescence and radioluminescence were well-known Ce3+ emissions located in the range of 470~600 nm consisting of two emission bands because of the transition from the lowest 5d excited state (2D) to the 4f ground state of Ce3+, which matched well with the sensitivity curve of the Si-photodiode. There was a little red shift for the emission components from the UV-excited emission spectrum to the X-ray-excited emission spectrum. The fast scintillation decay component of 26 ns satisfies the requirements of fast scintillators.

  16. Combinatorial optimization of La, Ce-co-doped pyrosilicate phosphors as potential scintillator materials.

    Science.gov (United States)

    Wei, Qinhua; Wan, Jieqiong; Liu, Guanghui; Zhou, Zhenzhen; Yang, Hua; Wang, Jiacheng; Liu, Qian

    2015-04-13

    A combinatorial method was employed to rapidly screen the effects of La, Ce-co-doping on the luminescent properties of Gd2Si2O7 pyrosilicate using an 8 × 8 library. The candidate formulations (Gd1-x-yLax)2Si2O7:Ce2y were evaluated by luminescence pictures under ultraviolet excitation. The optimal composition was found to be (Gd0.89La0.1)2Si2O7:Ce0.02 after scaled-up preparation and detailed characterization of powder samples, which shows an excellent light output under both ultraviolet and X-ray excitation (about 5.43 times of commercial YAG:Ce powders). The XRD results indicate that the phase structure sequence is tetragonal-orthorhombic-triclinic for different calcination temperatures and doping ions. The (Gd0.89La0.1)2Si2O7:Ce0.02 powder sample also demonstrated excellent temperature stability of luminescence up to 200 °C and a short decay time of several tens of nanoseconds, suggesting that this may represent a new kind of scintillation material, such as single crystals, ceramics, glass, or phosphors.

  17. Scintillation and Luminescence Properties of Undoped and Cerium-doped LiGdCl4 and NaGdCl4

    OpenAIRE

    Porter-Chapman, Yetta D.

    2008-01-01

    We report the scintillation properties of the undoped and cerium-doped variations of LiGdCl4 and NaGdCl4. Powder samples of these materials exhibit significant scintillation under X-rays. The samples were synthesized by solid-state methods from a 1:1 molar ratio of lithium or sodium chloride and gadolinium chloride. Cerium trichloride was used as the dopant. The physical, optical, and scintillation properties of these materials were analyzed by powder X-ray diffraction, photoluminescence, X-r...

  18. Scintillation and Luminescence Properties of Undoped and Cerium-doped LiGdCl4 and NaGdCl4

    Energy Technology Data Exchange (ETDEWEB)

    Porter-Chapman, Yetta D.; Bourret-Courchesne, Edith D.; Bizarri, Gregory; Weber, Marvin J.; Derenzo, Stephen E.

    2008-10-05

    We report the scintillation properties of the undoped and cerium-doped variations of LiGdCl4 and NaGdCl4. Powder samples of these materials exhibit significant scintillation under X-rays. The samples were synthesized by solid-state methods from a 1:1 molar ratio of lithium or sodium chloride and gadolinium chloride. Cerium trichloride was used as the dopant. The physical, optical, and scintillation properties of these materials were analyzed by powder X-ray diffraction, photoluminescence, X-ray excited luminescence, and pulsed X-ray luminosity measurements. Increases in light yields are observed as the concentration of cerium increases. The highest light yields occurred at 20 percent cerium doping for both compounds. At larger concentrations neither compound formed, indicating a breakdown of the lattice with the addition of large amounts of cerium cations. At 20 percent cerium, LiGdCl4 and NaGdCl4 display scintillation light 3.6 times and 2.2 times the light yield of the reference material, YAlO3:Ce3+, respectively. Both emit in the ranges of 340 ? 350 nm and 365 - 370 nm and display multiexponential decays with cerium-like decay components at 33 ns (LiGdCl4:Ce) and 26 ns (NaGdCl4:Ce).

  19. Analysis of single and binary phases in cerium doped sodium bismuth titanate -inorganic materials Na{sub 0}.5Bi{sub (}0.5-x)Ce{sub x}TiO{sub 3}; Estudio de fases simples y binarias en BNT puro y dopado con cerio Na{sub 0},5Bi{sub (}0,5-x)Ce{sub x}TiO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Supriya, S.; Dos Santos-Garcia, A. J.; Frutos, J. de; Fernandez-Martinez, F.

    2015-07-01

    The pure and cerium doped sodium bismuth titanate (NBT) inorganic powders were synthesized by solid-state reaction method. The presence of rhombohedral phase was observed in cerium doped NBT compounds. When x= 0.05 of cerium doped NBT is heat treated at 1200 degree centigrade, the compound forms single perovskite phase. The samples of x = 0.10 and 0.15 were heat treated up to 1350 degree centigrade, the binary phases with cerium and bismuth oxides were observed. The X-ray diffraction, Fourier transform infrared spectroscopy, reflectance spectra, differential thermal analysis and thermogravimetric analysis were used to analyze the various properties of samples. Moreover, the effects of cerium doping and calcining temperature on NBT samples were investigated. In this work, we present our recent results on the synthesis and characterization of cerium doped sodium bismuth titanate materials. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Selles, O

    2006-12-15

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

  1. Simulated-sunlight-activated photocatalysis of Methylene Blue using cerium-doped SiO2/TiO2 nanostructured fibers

    Institute of Scientific and Technical Information of China (English)

    Yu Liu; Hongbing Yu; Zhenning Lv; Sihui Zhan; Jiangyao Yang; Xinhong Peng; Yixuan Ren; Xiaoyan Wu

    2012-01-01

    Cerium-doped SiO2/TiO2 nanostructured fibers were fabricated by electrospinning technology.The prepared fibers were characterized by thermogravimetric analysis (TGA),scanning electron microscopy (SEM),X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR).Using the fibers as catalysts,photocatalytic degradation of Methylene Blue (MB) aqueous solution was carried out under simulated sunlight.The 0.2% Ce doping proved to be the optimal concentration for the doping of TiO2/SiO2,compared to other Ce-doped molar concentrations.The 0.2% Ce-doped SiO2/TiO2 fibers exhibited higher photocatalytic activity than industrial Degussa P25 and the samples doped with only Ce or SiO2.The reasons for improving the photocatalytic activity were also discussed.Several operational parameters were studied,which showed that the photocatalytic efficiency of MB was influenced by parameters such as the initial dye concentration,the initial pH,inorganic anions,and so on.In addition,the influences of an electron acceptor and a radical scavenger suggested that OH was the dominant photooxidant during the photocatalytic process.The reuse evaluation of the fibers indicated that their photocatalytic activity had good stability.

  2. Fabrication of cerium-doped nonstoichiometric (Ce, Lu, Gd)3+δ(Ga, Al)5-δO12 transparent ceramics

    Institute of Scientific and Technical Information of China (English)

    陈先强; 秦海明; 张烨; 罗朝华; 刘永福; 蒋俊; 江浩川

    2015-01-01

    Cerium-doped nonstoichiometric (Ce,Lu,Gd)3+δ(Ga,Al)5–δO12 (LuGGAG) transparent garnet ceramic samples were fabri-cated via a solid state reaction method in this study. The ceramics were prepared via oxygen sintering followed by hot isostatic press-ing (HIP). The phase and microstructure of the samples were analyzed by X-ray diffraction and scanning electron microscopy (SEM), respectively. The excitation, emission and transmission spectra were also measured. The total optical transmittance of the annealed LuGGAG ceramics with thickness of 3 mm reached 47% at the emission wavelength of 555 nm. The decay time was about 60 ns. Compact microstructure of polycrystalline grains with scale around 5μm were gained according to scanning electron microscopy characterization. The successful preparation of the bulk ceramic material and implementation of the combined oxygen sintering-hot isostatic pressing treatment process provided an important method for the exploration of nonstoichiometric scintillator material.

  3. Performance of cerium-doped Gd3Al2Ga3O12 (GAGG:Ce) scintillator in gamma-ray spectrometry

    Science.gov (United States)

    Iwanowska, Joanna; Swiderski, Lukasz; Szczesniak, Tomasz; Sibczynski, Pawel; Moszynski, Marek; Grodzicka, Martyna; Kamada, Kei; Tsutsumi, Kousuke; Usuki, Yoshiyuki; Yanagida, Takayuki; Yoshikawa, Akira

    2013-06-01

    Performance of cerium-doped Gd3Al2Ga3O12 (GAGG:Ce) scintillator in gamma-ray spectrometry has been investigated. The measurements of two samples of GAGG:Ce cover the tests of emission spectra (maximum of emission at about 530 nm), light output, non-proportionality, energy resolution, time resolution and decay time of light pulses. We compare the results with commonly known scintillators, such as NaI(Tl), LSO, LuAG etc. The results show that GAGG:Ce has a high light yield of about 33000 ph/MeV as measured with Hamamatsu S3590-18 Si PiN photodiode [1]. The total energy resolution for 662 keV gamma-rays from 137Cs source is equal to about 6%, whereas intrinsic resolution is equal to 5.2%. Additionally, we made basic measurements of photoelectron yield, non-proportionality and total energy resolution of small sample (5×5×5 mm3) of GAGG:Ce crystal coupled to Hamamatsu MPPC array (6×6 mm2). The results show that the performance of GAGG:Ce measured with the MPPC array are similar to those measured with the PMT.

  4. 固结磨料研磨掺铈玻璃与K9玻璃的对比研究%Research on fixed abrasive lapping of cerium doped glass and K9 glass

    Institute of Scientific and Technical Information of China (English)

    夏磊; 李军; 李鹏鹏; 朱永伟; 王文泽; 左敦稳

    2013-01-01

    在相同研磨条件下,采用固结磨料研磨垫研磨掺铈玻璃和K9玻璃,比较掺铈玻璃和K9玻璃的研磨材料去除率,研磨摩擦系数值和加工后表面质量.研究结果表明:金刚石固结磨料研磨垫对掺铈玻璃的材料去除率和研磨摩擦系数小于K9玻璃,表面质量相对较优.掺铈玻璃残屑中的Ce与Si在金刚石颗粒表面及磨粒之间形成包裹层和填覆层,改变材料去除机理,导致材料去除率和摩擦系数下降,获得更优的表面质量.%Fixed abrasive pad was employed to lap cerium doped glass and K9 glass in the same condition. Material removal rate(MRR) , lapping friction coefficient and surface quality were investigated. Results showed that MRR and lapping friction coefficient of cerium doped glass were less than those of K9 glass, but surface quality was better. The Ce and Si from the chips of cerium doped glass formed a covering layer on diamond particle surface and a filling layer in the gap between abrasives, thus changing the material removal mechanism. MRR and friction coefficient declined, and surface quality got better.

  5. Photocatalysis of S-metolachlor in aqueous suspension of magnetic cerium-doped mTiO2 core-shell under simulated solar light.

    Science.gov (United States)

    Mermana, J; Sutthivaiyakit, P; Blaise, C; Gagné, F; Charnsethikul, S; Kidkhunthod, P; Sutthivaiyakit, S

    2017-02-01

    Magnetic cerium-doped mesoporous titanium dioxide was synthesized by combining sol-gel method and calcination using tetrabutanate and ammonium cerium nitrate as precursors and Pluronic P123 as a template coating on iron oxide covered with carbon in ethanol. The magnetic Ce-doped catalyst showed only anatase structure with a slight increase in lattice parameters compared to the undoped catalyst. The Ce LIII-edge X-ray absorption near-edge spectroscopy (XANES) spectra showed Ce(3+), and the cerium substitution doping into titanium dioxide was proposed. Degradation of S-metolachlor in aqueous magnetic photocatalyst suspension followed (pseudo) first-order kinetics in the presence of 0.5 g L(-1) of γ-Fe2O3@C@0.16 mol% Ce-mTiO2 with a half-life of 55.18 ± 1.63 min. Fifteen degradation products were identified, and their transformation routes of the photocatalytic degradation were then proposed. Complementary toxicity assessment of the treated S-metolachlor solution was undertaken with Environment Canada's algal microplate assay measuring growth inhibition (72-h IC50) in the freshwater chlorophyte Pseudokirchneriella subcapitata. This test method revealed a significant decrease in toxicity (1.7-fold reduction after 180 min of irradiation treatment), thereby confirming that the by-products formed following photocatalysis would be less harmful from an environmental point of view. Photocatalytic degradation of S-metolachlor thus appears to hold promise as a cost-effective treatment technology to diminish the presence of this herbicide in aquatic systems.

  6. Performance of cerium-doped Gd{sub 3}Al{sub 2}Ga{sub 3}O{sub 12} (GAGG:Ce) scintillator in gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Iwanowska, Joanna, E-mail: j.iwanowska@ncbj.gov.pl [National Centre for Nuclear Research, 05-400 Otwock/Swierk (Poland); Swiderski, Lukasz; Szczesniak, Tomasz; Sibczynski, Pawel; Moszynski, Marek; Grodzicka, Martyna [National Centre for Nuclear Research, 05-400 Otwock/Swierk (Poland); Kamada, Kei; Tsutsumi, Kousuke; Usuki, Yoshiyuki [Furukawa Company Ltd., Tsukuba, 305-0856 Ibaraki (Japan); Yanagida, Takayuki; Yoshikawa, Akira [IMRAM, Tohoku University, Aoba-ku, Sendai, 980-8577 Miyagi (Japan)

    2013-06-01

    Performance of cerium-doped Gd{sub 3}Al{sub 2}Ga{sub 3}O{sub 12} (GAGG:Ce) scintillator in gamma-ray spectrometry has been investigated. The measurements of two samples of GAGG:Ce cover the tests of emission spectra (maximum of emission at about 530 nm), light output, non-proportionality, energy resolution, time resolution and decay time of light pulses. We compare the results with commonly known scintillators, such as NaI(Tl), LSO, LuAG etc. The results show that GAGG:Ce has a high light yield of about 33000 ph/MeV as measured with Hamamatsu S3590–18 Si PiN photodiode [1]. The total energy resolution for 662 keV gamma-rays from {sup 137}Cs source is equal to about 6%, whereas intrinsic resolution is equal to 5.2%. Additionally, we made basic measurements of photoelectron yield, non-proportionality and total energy resolution of small sample (5×5×5 mm{sup 3}) of GAGG:Ce crystal coupled to Hamamatsu MPPC array (6×6 mm{sup 2}). The results show that the performance of GAGG:Ce measured with the MPPC array are similar to those measured with the PMT.

  7. Ce-MCM-41分子筛用于臭氧氧化对氯苯甲酸的活性评价%Synthesis of cerium-doped MCM-41 for ozonation of p-chlorobenzoic acid

    Institute of Scientific and Technical Information of China (English)

    邴吉帅; 曾俊喻; 廖高祖; 李旭凯; 蓝冰燕; 张秋云; 李来胜

    2012-01-01

    Cerium-doped MCM-41(Ce-MCM-41) was prepared by a hydrothermal method and its catalytic activity for ozonation of p-chlorobenzoic acid(p-CBA) in aqueous solution was studied.Ce-MCM-41 was characterized by low angle X-ray powder diffraction(XRD),nitrogen adsorption-desorption(BET),ultraviolet-visible diffuse reflection spectrum(UV-Vis DRS) and transmission electron microscopy(TEM).The results showed that the material retained a highly ordered mesopore structure of pure silica MCM-41 and had a high surface area.Cerium was incorporated into the framework of MCM-41,locating at tetrahedrally coordinated sites.Ce-MCM-41 significantly improved the effect of ozone oxidation.After 60 min reaction time,TOC removal rate was 63% with MCM-41,86% with Ce-MCM-41(Si/Ce=60),while only 52% with O3 alone.Besides,Ce-MCM-41 had much less cerium leaching(0.085 mg·L-1) compared with that of Ce/MCM-41(0.44 mg·L-1).After being used for three times,TOC removal rate decreased only by 5%,while p-CBA removal rate kept nearly constant.Ce-MCM-41 is a promising catalyst for ozonation process.%通过水热法合成了铈掺杂MCM-41(Ce-MCM-41)介孔分子筛,并将其用于臭氧氧化水中对氯苯甲酸(p-CBA).小角X射线衍射(XRD)、氮气吸附-脱附(BET)、紫外可见漫反射光谱(UV-Vis DRS)、透射电镜(TEM)表征结果表明,铈成功进入MCM-41分子筛骨架,以正四面体形式存在,且Ce-MCM-41保持了纯硅MCM-41有序的介孔结构,具有较高的比表面积;铈的掺杂显著提高MCM-41催化臭氧氧化对氯苯甲酸的活性,反应60 min后,TOC去除率由MCM-41的63%提高到86%(Si/Ce=60),而单独臭氧氧化仅为52%;铈的溶出仅为0.085 mg.L-1,较同样负载量的铈负载Ce/MCM-41的溶出(0.44 mg.L-1)有较大减少.催化剂重复使用3次后仍保持较高的活性,这表明Ce-MCM-41具有较好的活性和稳定性,是一种有前景的臭氧氧化催化剂.

  8. Carbochlorination of yttrium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Gaviria, J.P., E-mail: gaviriaj@cab.cnea.gov.ar [Division Cinetica Quimica - Complejo Tecnologico Pilcaniyeu, Centro Atomico Bariloche - Comision Nacional de Energia Atomica, Av. Bustillo km 9500 (8400), S.C. de Bariloche, Rio Negro (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (Argentina); Bohe, A.E. [Division Cinetica Quimica - Complejo Tecnologico Pilcaniyeu, Centro Atomico Bariloche - Comision Nacional de Energia Atomica, Av. Bustillo km 9500 (8400), S.C. de Bariloche, Rio Negro (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (Argentina); Centro Regional Universitario Bariloche, Universidad Nacional del Comahue (Argentina)

    2010-09-20

    The reaction of chlorination of a mixture composed by Y{sub 2}O{sub 3} and sucrose carbon was studied by thermogravimetry over a temperature range of 550-950 {sup o}C. The reaction proceeds through several successive stages. The first of them is the formation of solid yttrium oxychloride (YOCl) and subsequently the YOCl is carbochlorinated to produce YCl{sub 3} (solid or liquid, depending on the temperature) in two stages. The stoichiometries of the first stage and the global reaction were estimated by mass balances, taking into account the chlorine adsorbed by the remainder carbon. The results showed that the reactions involved progress with the formation of CO{sub 2} and CO in the temperature range of 600-775 {sup o}C. The interaction between sucrose carbon and chlorine was analyzed by thermogravimetry in order to quantify the amount of chlorine which is adsorbed on its surface. It was studied the effect of the temperature and initial mass of carbon. The morphological analysis performed by SEM of partially reacted samples showed that the formation of YOCl proceeds through a mechanism of nucleation and growth. For temperatures above 715 {sup o}C the final product of the carbochlorination is liquid YCl{sub 3}, whose evaporation is observed in the thermogravimetry. The evaporation kinetics was analyzed in argon atmosphere and from the thermogravimetric curves was determined a value of 250 kJ/mol for the heat of evaporation of YCl{sub 3}. This value is consistent with a partial dimerization of the gaseous chloride.

  9. Preparation of nanometer yttrium oxide

    Institute of Scientific and Technical Information of China (English)

    HUO; Cheng-zhang; LIU; Zhi-qiang; LIANG; Zhen-feng; LI; Xing-ying

    2005-01-01

    The nanometer yttrium oxides were obtained through precipitation in aqueous solution by reaction with ammonium bicarbonate. The reaction between yttrium chloride and ammonium bicarbonate, the effect of surfactants on particle size and the methods of controlling agglomeration were studied. Compared to other methods, the method of controlling the agglomeration by adding surfactant is one of the best methods for controlling the agglomeration of nanometer particles in wetchemical process. Increasing surfactants in process of precipitation deduced particle size, obtained narrow size distribution of primary particles. As for the concentration range studied, excess surfactants increased the particle size on the contrary. Characteristics of the thermal decomposition of yttrium carbonate were studied. It indicated that the approximate chemical composition of the precipi tate was Y(OH)Clx (CO3)(1-x/2) · 3H2O,the cubic Y2O3 was obtained above 600℃ , the specific surface and the remain chloride of nanometer Y2O3 was decreased with calcinating temperature rising. The spherical nanometer yttrium oxide was gained with primary particles<50 nm,agglomerate distribution D50 < 150 nm, BET> 35 m2/g, agglomerate constant (D50/DBET ) <6.

  10. Mechanical Properties, Purifying Techniques and Processing Methods of Metal Yttrium

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The mechanical properties of metal yttrium such as strength, plasticity, hardness and elasticity were introduced. The purifying techniques of yttrium were discussed in detail. The processing methods for metal yttrium including extruding, forging, rolling, wiredrawing and welding were also introduced. Finally, the potential use of yttrium and its alloys were prospected.

  11. 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.

  12. Lattice contraction in photochromic yttrium hydride

    Energy Technology Data Exchange (ETDEWEB)

    Maehlen, Jan Petter, E-mail: jepe@ife.no; Mongstad, Trygve T.; You, Chang Chuan; Karazhanov, Smagul

    2013-12-15

    Highlights: •Photochromic yttrium hydride films (YH:O) were prepared by reactive sputtering. •Black and transparent YH:O films were studied by time-resolved synchrotron XRD. •Both YH:O samples showed a lattice contraction upon illumination. •Also exposure to the X-ray beam itself results in a lattice contraction. -- Abstract: A strong photochromic effect was recently discovered in thin films of oxygen-containing yttrium hydride taking place at room temperature and reacting to ultraviolet and visible light. In this paper, we report on a lattice contraction upon illumination observed for thin-film samples of photochromic yttrium hydride, recorded by time-resolved X-ray diffraction using synchrotron radiation. The time dependence of the lattice contraction is consistent with the observed photochromic response of the samples.

  13. Yttrium doped BSCF membranes for oxygen separation

    DEFF Research Database (Denmark)

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

    2011-01-01

    (x = 0.2) for iron resulted in a non-cubic crystal structure that did not exhibit oxygen permeation. The yttrium partial substitution in BSCFY discs (1.2 mm thick) delivered best results for x = 0.025, as oxygen fluxes reached 2.05 ml cm−2 min−1 at 900 °C, an increase of 160% as compared to a blank...... 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....

  14. Polymerization of ethylene oxide using yttrium isopropoxide

    NARCIS (Netherlands)

    Choi, Young K.; Stevels, W.M.; Ankone, Martinus J.K.; Dijkstra, Pieter J.; Kim, Sung W.; Feijen, Jan

    1996-01-01

    Well defined poly(ethylene oxide)s were prepared using yttrium isopropoxide as an initiator. End group analysis using 1H- and 13C NMR spectroscopy revealed that only polymers with isopropyl ether and hydroxyl end groups were produced. The molecular weight is controlled by the initial amount of

  15. Magnetic structure of holmium-yttrium superlattices

    DEFF Research Database (Denmark)

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

    1993-01-01

    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......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...... 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...

  16. Emerging blue-UV luminescence in cerium doped YAG nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Shirmane, Liana [Institute of Solid State Physics, University of Latvia, Riga (Lithuania); Pankratov, Vladimir [Research Center of Molecular Materials, University of Oulu (Finland)

    2016-06-15

    Time-resolved luminescence properties of Ce{sup 3+} doped Y{sub 3}Al{sub 5}O{sub 12} (YAG) nanocrystals have been studied by means of vacuum-ultraviolet excitation spectroscopy. It was discovered that additionally to the regular Ce{sup 3+} yellow-green emission which is well-known luminescence in YAG, new emission covering a broad spectral range from 2.7 eV to 3.5 eV was revealed in the luminescence spectra for all YAG:Ce nanocrystals studied. This blue-UV emission has fast decay time about 7 ns as well as intensive well-resolved excitation band peaking at 5.9 eV and, in contrast to green Ce{sup 3+} emission, practically is not excited at higher energies. The origin of the blue-UV emission is tentatively suggested and discussed. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Electrorheological Effects of Cerium-Doped TiO2

    Institute of Scientific and Technical Information of China (English)

    尹剑波; 赵晓鹏

    2001-01-01

    It is found that the doping of cerium ion into anatase TiO2 can improve the electrorheological (ER) effects of TiO2 and broaden the operational temperature range. Especially, the substitution of 7-11 mol% of the cerium dopant for Ti can obtain a relatively high shear stress, t-7.4kPa (at 4kV/mm), which is ten times larger than that of pure TiO2 ER fluid. Also, the typical Ce-doped TiO2 ER fluid shows the highest shear stress at 80℃, but 40℃ for pure TiO2 ER fluid. The dielectric loss and dielectric constant at a low frequency of TiO2 is improved by the doping of cerium, and the temperature dependence of the dielectric properties shows an obvious differnce between pure and doped TiO2 ER fluids. These can well explain the ER behaviour of doped TiO2. Furthermore, the change of rheological and dielectric properties is discussed on the basis of the lattice distortion and defects in TiO2 arising from the doping of cerium.

  18. EPDM composite membranes modified with cerium doped lead zirconate titanate

    Science.gov (United States)

    Zaharescu, T.; Dumitru, A.; Lungulescu, M. E.; Velciu, G.

    2016-01-01

    This study was performed on γ-irradiated ethylene-propylene diene terpolymer (EPDM) loaded with lead zirconate titanate. The inorganic phase has a perovskite structure with general formula Pb(Zr0.65-xCexTi0.35)O3. The three composites with different Ce dopant concentrations revealed the stabilization activity of filler against oxidation proved by chemiluminescence investigation in respect to pristine polymer. The presence of cerium low concentrations in the solid lead zirconate titanate nanoparticles causes significant slowing of oxidation rate during radiation exposure. The improvement in the stabilization feature of filler is correlated with the existence of traps, whose interaction with free radicals assumes medium energy due to their convenient depth.

  19. Role of nitrogen vacancies in cerium doped aluminum nitride

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-15

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

  20. DC electrical conductivity study of cerium doped conducting glass systems

    Science.gov (United States)

    Barde, R. V.; Waghuley, S. A.

    2013-06-01

    The glass samples of composition 60V2O5-5P2O5-(35-x)B2O3-xCeO2, (1 ≤ x ≤ 5) were prepared by the conventional melt quench method. The samples were characterized by X-ray diffraction and thermo gravimetric-differential thermal analysis. The glass transition temperature and crystallization temperature determined from TG-DTA analysis. The DC electrical conductivity has been carried out in the temperature range 303-473 K. The maximum conductivity and minimum activation energy were found to be 0.039 Scm-1 and 0.15 eV at 473 K for x=1, respectively.

  1. Ferroelectricity in yttrium-doped hafnium oxide

    OpenAIRE

    Müller, J.; Schröder, U; Böscke, T. S.; Müller, I.; U. Böttger; De Wilde, L; Sundqvist, J.; Lemberger, M.; Kücher, P.; Mikolajick, T; Frey, Lothar

    2012-01-01

    Structural and electrical evidence for a ferroelectric phase in yttrium doped hafnium oxide thin films is presented. A doping series ranging from 2.3 to 12.3 mol% YO1.5 in HfO2 was deposited by a thermal atomic layer deposition process. Grazing incidence X-ray diffraction of the 10 nm thick films revealed an orthorhombic phase close to the stability region of the cubic phase. The potential ferroelectricity of this orthorhombic phase was confirmed by polarization hysteresis measurements on tit...

  2. 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.

  3. Unconventional Superfluidity in Yttrium Iron Garnet Films

    Science.gov (United States)

    Sun, Chen; Nattermann, Thomas; Pokrovsky, Valery L.

    2016-06-01

    We argue that the magnon condensate in yttrium iron garnet may display experimentally observable superfluidity at room temperature despite the 100 times dominance of the normal density over superfluid ones. The superfluidity has a more complicated nature than in known superfluids since the U(1) symmetry of the global phase shift is violated by the dipolar interaction leading to the exchange of spin moment between the condensate and the crystal lattice. It produces periodic inhomogeneity in the stationary superfluid flow. We discuss the manner of observation and possible applications of magnon superfluidity. It may strongly enhance the spin-torque effects and reduce the energy consumption of the magnonic devices.

  4. Thermal Spin Dynamics of Yttrium Iron Garnet

    Science.gov (United States)

    Barker, Joseph; Bauer, Gerrit E. W.

    2016-11-01

    The magnetic insulator yttrium iron garnet can be grown with near perfection and is therefore and ideal conduit for spin currents. It is a complex material with 20 magnetic moments in the unit cell. In spite of being a ferrimagnet, YIG is almost always modeled as a simple ferromagnet with a single spin wave mode. We use the method of atomistic spin dynamics to study the temperature evolution of the full spin wave spectrum, in quantitative agreement with neutron scattering experiments. The antiferromagnetic or optical mode is found to suppress the spin Seebeck effect at room temperature and beyond due to thermally pumped spin currents with opposite polarization to the ferromagnetic mode.

  5. Morphology controllable synthesis of yttrium oxide-based phosphors from yttrium citrate precursors

    Institute of Scientific and Technical Information of China (English)

    HUANG Manlian; GUO Kai; MAN Zhenyong; CHEN Haohong; YANG Xinxin; XU Fangfang; ZHAO Jingtai

    2011-01-01

    A novel yttrium citrate-templated conversion method for morphology controlled synthesis ofY2O3 microspheres,microflowers and microsheets was reported for the first time.The precursors with controllable morphologies were synthesized with a homogenous precipitation method in aqueous solution without any surfactant.Y2O3 samples with well-preserved morphological architectures were obtained by a subsequent thermal transformation strategy.The chemical formula of the precursor was identified and a two-stage growth mechanism was proposed.The effects of the aging time,reaction temperature,reactant concentration and molar ratio of yttrium nitrate to sodium citrate were discussed.The photoluminescence properties of the Y2O3∶Eu3+ microspheres,microflowers and microsheets prepared were also studied.

  6. Ferroelectricity in yttrium-doped hafnium oxide

    Science.gov (United States)

    Müller, J.; Schröder, U.; Böscke, T. S.; Müller, I.; Böttger, U.; Wilde, L.; Sundqvist, J.; Lemberger, M.; Kücher, P.; Mikolajick, T.; Frey, L.

    2011-12-01

    Structural and electrical evidence for a ferroelectric phase in yttrium doped hafnium oxide thin films is presented. A doping series ranging from 2.3 to 12.3 mol% YO1.5 in HfO2 was deposited by a thermal atomic layer deposition process. Grazing incidence X-ray diffraction of the 10 nm thick films revealed an orthorhombic phase close to the stability region of the cubic phase. The potential ferroelectricity of this orthorhombic phase was confirmed by polarization hysteresis measurements on titanium nitride based metal-insulator-metal capacitors. For 5.2 mol% YO1.5 admixture the remanent polarization peaked at 24 μC/cm2 with a coercive field of about 1.2 MV/cm. Considering the availability of conformal deposition processes and CMOS-compatibility, ferroelectric Y:HfO2 implies high scaling potential for future, ferroelectric memories.

  7. 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.

  8. 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.

  9. 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.

  10. Studies on yttrium-containing smart alloys

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-01

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

  11. Mechanical properties of lanthanum and yttrium chromites

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  12. 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.

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

    Science.gov (United States)

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

    2014-04-01

    This report introduces the discovery of crystalline defects that can form in the porcelain veneering layer when in contact with yttria-stabilized zirconia (YSZ). The focus was on dental prostheses and understanding the defects that form in the YSZ/porcelain system; however the data reported herein may have broader implications toward the use and stability of YSZ-based ceramics in general. Specimens were cut from fully sintered YSZ plates and veneering porcelain was applied (porcelain veneer. Local EDAX (SEM) was performed in the regions of visible inclusions and showed significant increases in yttrium concentration. TEM specimens also showed apparent inclusions in the porcelain and selected area electron diffraction was performed on these regions and found the inclusions to be crystalline and identified as either yttrium-silicate (Y2 SiO5 ) or yttrium-disilicate (Y2 Si2 O7 ). Micro-CT data showed that yttrium-silicate precipitates were distributed throughout the thickness of the porcelain veneer. Future studies are needed to determine whether many of the premature failures associated with this materials system may be the result of crystalline flaws that form as a result of high temperature yttrium diffusion near the surfaces of YSZ.

  14. 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...

  15. 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...

  16. Scintillation properties of Lu sub 2 Si sub 2 O sub 7 :Ce sup 3 sup + , a fast and efficient scintillator crystal

    CERN Document Server

    Pidol, L; Viana, B; Ferrand, B; Dorenbos, P; Haas, J; Eijk, C W E; Virey, E

    2003-01-01

    Cerium doped lutetium pyrosilicate Lu sub 2 Si sub 2 O sub 7 :Ce sup 3 sup + (LPS), a new inorganic scintillator, displays particularly promising performance. This material can be readily pulled from the melt. A high light output (average value: 26 300 ph MeV sup - sup 1), a relatively good energy resolution (9%) and a fast decay time (38 ns) without afterglow make this new scintillator very attractive, in particular for medical imaging. Optical characterizations and scintillation properties of LPS:Ce large single crystals are presented, including timing properties and study of the scintillation yields as a function of incident energy.

  17. 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.

  18. 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.

  19. High performance yttrium-doped BSCF hollow fibre membranes

    DEFF Research Database (Denmark)

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

    2012-01-01

    Oxygen production from BSCF (Ba0.5Sr0.5Co0.8Fe0.2O3−δ) and yttrium-doped BSCF (Ba0.5Sr0.5Co0.8Fe0.175Y0.025O3−δ) hollow fibres was investigated, and the role of yttrium in the crystal structure was further explored using high-temperature X-ray diffraction. Yttrium substitution acted to increase...... the oxygen flux significantly, from 4.9 to 7.0mlcm−2min−1 at 900°C for the BSCF and the BSCFY membranes, respectively. Permeation was particularly enhanced at lower temperatures, between 66% and 92% over the range 650–800°C. The lattice expansion determined from high temperature X-ray diffraction.......3mm) hollow fibres operating below the critical length (i.e. limited surface kinetics regime) indicates that yttrium has enhanced the surface exchange rates. XRD patterns showed split peaks around 2θ 31° and 56° above 200°C, likely corresponding to a coexisting hexagonal perovskite phase. This peak...

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  2. Yttrium-90 DOTATOC: first clinical results

    Energy Technology Data Exchange (ETDEWEB)

    Otte, A. [Basel Univ. (Switzerland). Nuklearmedizinische Abt.; Herrmann, R. [University Hospital, School of Medicine, Basel (Switzerland). Dept. of Oncology; Heppeler, A.; Behe, M.; Jermann, E.; Powell, P.; Maecke, H.R.; Muller, J. [University Hospital, School of Medicine, Basel (Switzerland). Inst. of Radiochemistry

    1999-11-01

    In a pilot study, DOTA-d-Phe{sup 1}-Tyr{sup 3}-octreotide (DOTATOC), which can be labelled with the {beta}-emitting radioisotope yttrium-90, has recently been used for the treatment of patients with advanced somatostatin receptor-positive tumours who had no other treatment option. The aim of the present study was to elucidate the therapeutic potential of {sup 90}Y-DOTATOC in a larger number of patients employing a standardized treatment protocol. Careful attention was paid to any side-effects (renal and/or haematological toxicity). Of 44 patients with advanced somatostatin receptor-positive tumours of different histology, 29 could be included in the study. The 15 patients who were excluded from the study protocol were assigned to our institution for purely compassionate reasons. The 29 patients who were included received four or more single doses of {sup 90}Y-DOTATOC with ascending activity at intervals of approximately 6 weeks (cumulative dose 6120{+-}1347 MBq/m{sup 2}) with the aim of performing an intra-patient dose escalation study. In total, 127 single treatments were given. In eight of these 127 single treatments, total doses of {>=}3700 MBq were administered. In an effort to prevent renal toxicity, two patients received Hartmann-Hepa 8% solution during all therapy cycles, while 13 patients did so during some but not all therapy cycles; in 14 patients no solution was administered during the therapy cycles. The treatment was monitored by computed tomography and indium-111 DOTATOC scintigraphy. Blood parameters were controlled weekly, while tumour markers and liver enzymes were controlled 6-weekly. Of the 29 patients, 24 patients showed no severe renal or haematological toxicity (toxicity {<=} grade 2 according to the National Cancer Institute grading criteria). These 24 patients received a cumulative dose of {<=}7400 MBq/m{sup 2}. Five patients developed renal and/or haematological toxicity. All of these five patients received a cumulative dose of >7400 MBq

  3. Synthesis and characterization of yttrium-aluminum-iron and yttrium-cerium-iron citric complexes

    Institute of Scientific and Technical Information of China (English)

    N. Petrova; D. Todorovsky; I. Mitov; Tyuliev

    2008-01-01

    Fe-, Y-Fe-Al- and Y-Ce-Fe- citrates were synthesized in ethylene glycol (EG) medium under conditions similar to those used in the polymerized complex method. Their elemental composition, IR, 13C and 1H NMR, X-ray photoelectron and Mossbauer spectra were studied, and formulae describing their composition were proposed. The complexes contained EG bonded as adduct and ester with citric acid ligand and did not contain ligands with deprotonated alcoholic groups. The complexes consisted of agglomerated spheres, 0.7-3μm in diameter. The local composition of the products was established by energy dispersive X-ray microanalysis. The comparison of the number of the ligands, their average electrical charge and the esterification degree of mono-, di- and trimetallic complexes proved the mixed-metal nature of the species studied. The thermal decomposition of the complexes was studied and a general scheme of the processes taking place was proposed. Highly crystalline, phase homogeneous Y3Fe4AlO12 was produced after heating the respective complex at 1000℃. Ce-doped yttrium-iron garnet, similarly prepared, contained traces of CeO2.

  4. Synthesis of aluminum-based scandium-yttrium master alloys

    Science.gov (United States)

    Bazhin, V. Yu.; Kosov, Ya. I.; Lobacheva, O. L.; Dzhevaga, N. V.

    2015-07-01

    The preparation technology for an Al-2% Sc-0.5% Y master alloy using aluminum-manganese alloys has been developed and tested. The microstructure of the prepared master alloy is studied and the compositions of intermetallics is determined. The efficient technological parameters of the synthesis are determined. It is shown that varying the compositions of starting reagents and alloying additions and optimizing the process conditions (temperature, mixing, etc.) allow us to forecast the manufacturing and operating characteristics of aluminum-based master alloys. Joint additions of scandium and yttrium oxides to a charge favor a substantial decrease in the grain size of the formed intermetallics; this effect appears to the utmost in the case of microallying with yttrium up to 0.5 wt %.

  5. 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...... 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...

  6. Hydrocarbon cracking with yttrium exchanged zeolite y catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Lochow, C.F.; Kovacs, D.B.

    1987-05-12

    A process is described for cracking a gas oil boiling range hydrocarbon feedstock comprising the step of contacting the feedstock in a catalytic cracking zone under catalytic cracking conditions to produce convulsion products comprising gasoline with a catalyst composition. The process comprises: a Y crystalline aluminosilicate zeolite, having the structure of faujasite and having uniform pore diameters and a silica to alumina mole ratio of at least about 5; an inorganic oxide matrix; and the zeolite having been ion exchanged with a mixture of rare earths prior to compositing with the matrix; and the zeolite having been subsequently further ion exchanged with yttrium following compositing with the matrix, whereby the catalyst composition contains 0.30 to 3.0 wt% yttrium.

  7. Determination of Trace Amount of Yttrium with Bromopyrogallol Red by Solid-phase Spectrophotometry

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A simple and sensitive method for the determination of trace amount of yttrium by solid-phase spectrophotometry has been studied. Yttrium can form a 1∶1 complex with bromopyrogallol red (BPR) on resin, which was determined directly at 605 nm, pH=6.5. It has a highly sensitivity ( = 6.3€?06) which is 300-fold higher than the corresponding spectrophotometry in solution. The method was applied to the determination of yttrium in churchite.

  8. Upconversion luminescence in Yb 3+-doped yttrium aluminum garnets

    Science.gov (United States)

    Xu, Xiaodong; Zhao, Zhiwei; Song, Pingxin; Jiang, Benxue; Zhou, Guoqing; Xu, Jun; Deng, Peizhen; Bourdet, Gilbert; Christophe Chanteloup, Jean; Zou, Ji-Ping; Fulop, Annabelle

    2005-03-01

    In this paper, we present results on upconversion luminescence performed on Yb 3+-doped yttrium aluminum garnets under 940 nm excitation. The upconversion luminescence was ascribed to Yb 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 3+ energy migration quenched the cooperative luminescence of Yb:YAG crystals with doping level over 15 at%.

  9. Collectivity of the neutron-deficient odd yttrium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Bucurescu, D.; Cata, G.; Ivascu, M.; Zamfir, N.V.; Liang, C.F.; Paris, P.

    1988-08-01

    Multishell IBFM-1 calculations are reported for the neutron-deficient odd yttrium isotopes (79-85), which give a good description of both the positive and negative parity levels known experimentally. An exchange force whose intensity varies with the mass number is required. This phenomenological variation reflects qualitatively the microscopic origin of the exchange term, and also points to possible systematics of the model parameters in the ALPHA approx. = 80 region of the Nsub(p)Nsub(n) type.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-03-01

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

  11. Kinetic characteristics of the luminescence decay for industrial yttrium-gadolinium-aluminium garnet based phosphors

    OpenAIRE

    Lisitsyn, Viktor Mikhailovich; Stepanov, Sergey Aleksandrovich; Valiev, Damir Talgatovich; Vishnyakova, E. A.; Abdullin, H. A.; Marhabaeva, A. A.; Tulegenova, A. T.

    2016-01-01

    The spectral and decay kinetic characteristics of pulse cathodoluminescence and photoluminescence of phosphors based on yttrium-gadolinium-aluminum garnet were investigated using pulsed optical time resolved spectroscopy.

  12. 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.

  13. Infrared spectra of oxygen-rich yttrium and lanthanum dioxygen/ozonide complexes in solid argon.

    Science.gov (United States)

    Gong, Yu; Ding, Chuanfan; Zhou, Mingfei

    2009-07-30

    The reactions of yttrium and lanthanum atoms with O(2) have been reinvestigated using matrix isolation infrared spectroscopy and theoretical calculations. The ground-state yttrium and lanthanum atoms react with O(2) to produce the inserted yttrium and lanthanum dioxide molecules as the initial products. The yttrium dioxide molecule interacts spontaneously with additional O(2) molecules to form the oxygen-rich OY(eta(2)-O(3)) complex and possibly the (eta(2)-O(2))Y(eta(2)-O(3))(2) complexes upon sample annealing, which can be regarded as the side-on bonded yttrium monoxide ozonide complex and the superoxo yttrium bisozonide complex, respectively. Visible irradiation induces the isomerization of the OY(eta(2)-O(3)) complex to the superoxo yttrium peroxide Y(eta(2)-O(2))(2) isomer, in which both the superoxo and peroxo ligands are side-on bonded to the yttrium center. The lanthanum dioxide molecule reacts with additional O(2) molecules to form the lanthanum dioxide-dioxygen complex with planar C(2v) symmetry, which rearranges to the lanthanum monoxide ozonide complex, OLa(eta(2)-O(3)), under near-infrared excitation.

  14. Effect of Yttrium on High Temperature Oxidation Resistance of a Directionally Solidified Superalloy

    Institute of Scientific and Technical Information of China (English)

    宋立国; 李树索; 郑运荣; 韩雅芳

    2004-01-01

    The effect of rare earth element yttrium on the high temperature oxidation resistance of a directionally solidified Ni-base superalloy was studied with scanning electron microscopy(SEM), energy dispersive spectrum(EDS)and X-ray diffraction(XRD)techniques. The results show that the oxidation resistance of the alloy is substantially improved by adding proper amount of yttrium.

  15. 40 CFR 721.10177 - Phosphoric acid, yttrium(3+) salt (1:1).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phosphoric acid, yttrium(3+) salt (1:1... Specific Chemical Substances § 721.10177 Phosphoric acid, yttrium(3+) salt (1:1). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-01-01

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

  17. Phase composition of yttrium-doped zirconia ceramics

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-06-01

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

  18. Spectroscopic properties of trivalent praseodymium in barium yttrium fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Di Bartolo, B. E-mail: dibartob@bc.edurinodiba@attbi.com; Bowlby, B.E

    2003-05-01

    We have conducted a spectroscopic investigation of Pr{sup 3+} in barium yttrium fluoride (BaY{sub 2}O{sub 8}). Two doping concentrations were used: BaY{sub 2}F{sub 8}:Pr{sup 3+} (0.3%) and BaY{sub 2}F{sub 8}:Pr{sup 3+} (1%). The measurements included absorption, luminescence under continuous and pulsed excitations, and thermal effects on some sharp lines. The experimental results were used to characterize this system.

  19. Structure of molten yttrium aluminates: a neutron diffraction study

    Energy Technology Data Exchange (ETDEWEB)

    Cristiglio, V [Centre de Recherche sur les Materiaux a Haute Temperature, CNRS-CRMHT, 1d avenue de la Recherche Scientifique, 45071 Orleans cedex 2 (France); Hennet, L [Centre de Recherche sur les Materiaux a Haute Temperature, CNRS-CRMHT, 1d avenue de la Recherche Scientifique, 45071 Orleans cedex 2 (France); Cuello, G J [Institut Laue-Langevin, 6 rue Jules Horowitz, BP48 Grenoble cedex 9 (France); Pozdnyakova, I [Centre de Recherche sur les Materiaux a Haute Temperature, CNRS-CRMHT, 1d avenue de la Recherche Scientifique, 45071 Orleans cedex 2 (France); Johnson, M R [Institut Laue-Langevin, 6 rue Jules Horowitz, BP48 Grenoble cedex 9 (France); Fischer, H E [Institut Laue-Langevin, 6 rue Jules Horowitz, BP48 Grenoble cedex 9 (France); Zanghi, D [Centre de Recherche sur les Materiaux a Haute Temperature, CNRS-CRMHT, 1d avenue de la Recherche Scientifique, 45071 Orleans cedex 2 (France); Van, Q Vu [Institute of Mathematical and Physical Sciences, University of Wales, Aberystwyth SY23 3BZ (United Kingdom); Wilding, M C [Institute of Mathematical and Physical Sciences, University of Wales, Aberystwyth SY23 3BZ (United Kingdom); Greaves, G N [Institute of Mathematical and Physical Sciences, University of Wales, Aberystwyth SY23 3BZ (United Kingdom); Price, D L [Centre de Recherche sur les Materiaux a Haute Temperature, CNRS-CRMHT, 1d avenue de la Recherche Scientifique, 45071 Orleans cedex 2 (France)

    2007-10-17

    We used the aerodynamic levitation technique combined with CO{sub 2} laser heating to study the structure of liquid yttrium aluminates above their melting point with neutron diffraction. For various yttria contents, we determined the structure factors and corresponding pair correlation functions describing the short-range order in the liquids. In particular, we derived Al-O and Y-O bond distances and coordination numbers. Experimental data are compared with ab initio molecular dynamics, carried out using the VASP code where the interatomic forces are obtained from density functional theory. In particular, partial pair correlation functions have been calculated and are in relatively good agreement with the experimental observations.

  20. Treatment of exhaust fluorescent lamps to recover yttrium: experimental and process analyses.

    Science.gov (United States)

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

    2011-12-01

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

  1. Yttrium oxide based three dimensional metamaterials for visible light cloaking

    Science.gov (United States)

    Rai, Pratyush; Kumar, Prashanth S.; Varadan, Vijay K.; Ruffin, Paul; Brantley, Christina; Edwards, Eugene

    2014-04-01

    Metamaterial with negative refractive index is the key phenomenon behind the concept of a cloaking device to hide an object from light in visible spectrum. Metamaterials made of two and three dimensional lattices of periodically placed electromagnetic resonant cells can achieve absorption and propagation of incident electromagnetic radiation as confined electromagnetic fields confined to a waveguide as surface plasmon polaritons, which can be used for shielding an object from in-tune electromagnetic radiation. The periodicity and dimensions of resonant cavity determine the frequency, which are very small as compared to the wavelength of incident light. Till now the phenomena have been demonstrated only for lights in near infrared spectrum. Recent advancements in fabrication techniques have made it possible to fabricate array of three dimensional nanostructures with cross-sections as small as 25 nm that are required for negative refractive index for wavelengths in visible light spectrum of 400-700 nm and for wider view angle. Two types of metamaterial designs, three dimensional concentric split ring and fishnet, are considered. Three dimensional structures consisted of metal-dielectric-metal stacks. The metal is silver and dielectric is yttrium oxide, other than conventional materials such as FR4 and Duroid. High κ dielectric and high refractive index as well as large crystal symmetry of Yttrium oxide has been investigated as encapsulating medium. Dependence of refractive index on wavelength and bandwidth of negative refractive index region are analyzed for application towards cloaking from light in visible spectrum.

  2. Theoretical investigation on homoleptic Yttrium tri-guanidinates

    Directory of Open Access Journals (Sweden)

    Salima Lakehal

    2014-12-01

    Full Text Available The electronic and molecular structures of the homoleptic Yttrium tris-guanidinates complexes Y[(NiPr2CNR1R2]3, [R1 = R2 = Me, Et and iPr] have been investigated employing DFT calculations in order to understand the structures, bonding and energies of the interactions between Yttrium metal and guanidinate ligands. The effect of the substitution on nitrogen position of guanidinate in these complexes has been also investigated employing DFT and TDDFT calculations for six kinds of models obtained by alternative substitution of alkyl on nitrogen of the guanidinate ligands. The results reveal that the substitution position plays a crucial role in the geometric structure by affecting the torsion angle and the HOMO–LUMO transitions. The energy decomposition analysis indicates a majority of ionic bonding in all systems; the exception is in the M4 (Y[(NYR2CNCR1R2]3; R = Et and R1 = R2 = H which present a significant degree of covalency.

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

    Science.gov (United States)

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

    2013-11-01

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

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

    Science.gov (United States)

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

    2013-11-01

    This work is focused on the recovery of yttrium and zinc from fluorescent powder of cathode ray tube (CRT). Metals are extracted by sulphuric acid in the presence of hydrogen peroxide. Leaching tests are carried out according to a 2(2) full factorial plan and the highest extraction yields for yttrium and zinc equal to 100% are observed under the following conditions: 3M of sulphuric acid, 10% v/v of H2O2 concentrated solution at 30% v/v, 10% w/w pulp density, 70°C and 3h of reaction. Two series of precipitation tests for zinc are carried out: a 2(2) full factorial design and a completely randomized factorial design. In these series the factors investigated are pH of solution during the precipitation and the amount of sodium sulphide added to precipitate zinc sulphide. The data of these tests are used to describe two empirical mathematical models for zinc and yttrium precipitation yields by regression analysis. The highest precipitation yields for zinc are obtained under the following conditions: pH equal to 2-2.5% and 10-12%v/v of Na2S concentrated solution at 10%w/v. In these conditions the coprecipitation of yttrium is of 15-20%. Finally further yttrium precipitation experiments by oxalic acid on the residual solutions, after removing of zinc, show that yttrium could be recovered and calcined to obtain the final product as yttrium oxide. The achieved results allow to propose a CRT recycling process based on leaching of fluorescent powder from cathode ray tube and recovery of yttrium oxide after removing of zinc by precipitation. The final recovery of yttrium is 75-80%.

  5. Development of yttrium alloy ion source and its application in nanofabrication

    Energy Technology Data Exchange (ETDEWEB)

    Kukharchyk, Nadezhda [Angewandte Festkoerperphysik, Ruhr-Universitaet Bochum, Bochum (Germany); Experimentalphysik, Universitaet des Saarlandes, Saarbruecken (Germany); Neumann, Ronna; Mazarov, Swetlana; Wieck, Andreas D. [Angewandte Festkoerperphysik, Ruhr-Universitaet Bochum, Bochum (Germany); Bushev, Pavel [Experimentalphysik, Universitaet des Saarlandes, Saarbruecken (Germany); Mazarov, Paul [Raith GmbH, Dortmund (Germany)

    2016-12-15

    We present a new YAuSi Liquid Metal Alloy Ion Source (LMAIS) generating focused ion beams of yttrium ions, and its prospective applications for nanofabrication, sample preparation, lithographic and implantation processes. Working parameters of the AuSiY LMAIS are similar to other gold-silicon based LMAIS. We found anomalously high emission current of triple charged yttrium ions. Influence of yttrium implantation on optical qualities of the implanted ion-ensembles is shown in luminescence of co-implanted Erbium ions. (orig.)

  6. Development of yttrium alloy ion source and its application in nanofabrication

    Science.gov (United States)

    Kukharchyk, Nadezhda; Neumann, Ronna; Mazarov, Swetlana; Bushev, Pavel; Wieck, Andreas D.; Mazarov, Paul

    2016-12-01

    We present a new YAuSi Liquid Metal Alloy Ion Source (LMAIS) generating focused ion beams of yttrium ions, and its prospective applications for nanofabrication, sample preparation, lithographic and implantation processes. Working parameters of the AuSiY LMAIS are similar to other gold-silicon based LMAIS. We found anomalously high emission current of triple charged yttrium ions. Influence of yttrium implantation on optical qualities of the implanted ion-ensembles is shown in luminescence of co-implanted Erbium ions.

  7. Development of Yttrium alloy ion source and its application in nanofabrication

    CERN Document Server

    Kukharchyk, Nadezhda; Mazarov, Swetlana; Bushev, Pavel; Wieck, Andreas; Mazarov, Paul

    2016-01-01

    We present a new YAuSi Liquid Metal Alloy Ion Source (LMAIS), generating focused ion beams of yttrium ions, and its prospective applications for nanofabrication, sample preparation, lithographic and implantation processes. Working parameters of the AuSiY LMAIS are similar to other gold-silicon based LMAIS. We found anomalously high emission current of triple charged Yttrium ions. Influence of Yttrium implantation on optical qualities of the implanted ion-ensembles is shown in luminescence of co-implanted Erbium ions.

  8. Hot Corrosion Behavior of Sputtered Nanocrystalline Coating with Yttrium Addition at 900 °C

    Directory of Open Access Journals (Sweden)

    Wei Jiang

    2014-04-01

    Full Text Available The high temperature corrosion behavior of sputtered nanocrystalline K38 coating with and without yttrium addition under mixed molten salt film in air was investigated. Accelerated corrosion occurred on the coating without yttrium (Y addition locally after 60 h exposure at 900 °C, which resulted in negative weight gain in kinetics. A uniform and protective alumina scale formed on surface of the coating containing yttrium in comparison. Y enriched particle as corrosion product was observed on the top of alumina scale. The results indicated the beneficial influence of Y on the chemical stability of the protective scale in the presence of chloride. The mechanism was discussed.

  9. Transport of yttrium metal ions through fibers supported liquid membrane solvent extraction

    Institute of Scientific and Technical Information of China (English)

    A.G.Gaikwad; A.M.Rajput

    2010-01-01

    A novel idea of transport of yttrium(Ⅲ) metal ions through fibers supported liquid membrane in two stage processes namely source to membrane and membrane to receiving phase has been proposed.The fibers supported liquid membrane was impregnated with different concentrations carrier.The experimental variables explored were concentration of yttrium(Ⅲ) ions,pH of source phase,PC-88A concentration in membrane phase,acid concentration in receiving phase and stirring speed.The pre-concentration of yttrium(Ⅲ) ions ...

  10. 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.

  11. Sol-Gel Synthesis and Antioxidant Properties of Yttrium Oxide Nanocrystallites Incorporating P-123

    OpenAIRE

    Rebeca Mellado-Vázquez; Margarita García-Hernández; Arturo López-Marure; Perla Yolanda López-Camacho; Ángel de Jesús Morales-Ramírez; Hiram Isaac Beltrán-Conde

    2014-01-01

    Yttrium oxide (Y2O3) nanocrystallites were synthesized by mean of a sol-gel method using two different precursors. Raw materials used were yttrium nitrate and yttrium chloride, in methanol. In order to promote oxygen vacancies, P-123 poloxamer was incorporated. Synthesized systems were heat-treated at temperatures from 700 °C to 900 °C. Systems at 900 °C were prepared in the presence and absence of P-123 using different molar ratios (P-123:Y = 1:1 and 2:1). Fourier transform infrared spectros...

  12. 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

  13. Yttrium-90 Radioembolization of Hepatic Metastases from Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Raval eMihir

    2014-07-01

    Full Text Available Liver metastases from colorectal cancer (CRC result in substantial morbidity and mortality. The primary treatment is systemic chemotherapy, and in selected patients, surgical resection; however, for patients who are not surgical candidates and/or fail systemic chemotherapy, liver-directed therapies are increasingly being utilized. Yttrium-90 (Y-90 microsphere therapy, also known as selective internal radiation therapy (SIRT or radioembolization, has proven to be effective in terms of extending time to progression of disease and also providing survival benefit. This review focuses on the use of Y-90 microsphere therapy in the treatment of liver metastases from CRC, including a comprehensive review of published clinical trials and prospective studies conducted thus far. We review the methodology, outcomes and side effects of Y-90 microsphere therapy for metastatic CRC

  14. Synthesis and characterization of yttrium aluminium garnet (YAG powders

    Directory of Open Access Journals (Sweden)

    Magdalena Zarzecka-Napierala

    2007-12-01

    Full Text Available In this paper synthesis and characterization of YAG powders, prepared by a process based on complexing properties of citric acid, was reported. Influence of citric acid estrification induced by 2-propanol or ethylene glycol on the system homogeneity was investigated. These reagents were introduced to aqueous solution of yttrium and aluminium nitrates. A variety of powders from Al2O3-Y2O3 system with different phase composition were obtained by altering the citrate to nitrate ratio. Evolution of the powders phase composition vs. temperature was investigated using DTA/TG, XRD, and FT-IR methods. The most interesting results were observed in case of the citric acid–propanol–relative nitrates system. The mole ratio of these reagents equal to 1:2.5:2.5 (nitrates (Al,Y:citric acid:2-propanol allowed to synthesize pure YAG phase powders at temperature as low as 950°C.

  15. 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...... into Y2O2CO3 with release of CO2 and 6-undecanone between 280°C and 490°C. A side reaction appears to yield elemental carbon and volatile decane (C10H22). Y2O2CO3 is converted to Y2O3 with release of CO2 between 500°C and 975°C....

  16. Local structure of oxygen-deficient Yttrium oxide

    Institute of Scientific and Technical Information of China (English)

    CHENG Xue-Rui; DAI Hai-Yang; QI Ze-Ming; WANG Yu-Yin; ZHANG Guo-Bin

    2013-01-01

    Yttrium oxide thin films have been deposited on Si (100) substrate by using pulsed laser deposition (PLD) method.X-ray diffraction (XRD),hard and soft X-ray absorption spectroscopy (XAFS) are employed to investigate the origin of oxygen vacancies and their influence on the structure and atomic distributions.The XRD results indicate that the Y2O3 thin films strongly orient the (111) axis of the cubic structure.Analyses on the Y K-edge extended X-ray absorption fine structures reveal that the coordination number of Y atoms decreases and the bond length of Y-O contracts due to the loss of oxygen atoms.The X-ray absorption near edge structure analysis together with a theoretical approach further confirms the oxygen vacancies formation and their possible location.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Swati, E-mail: sharma.swati1507@gmail.com; Kashyap, Jyoti; Kapoor, A. [Department of Electronic Science, University of Delhi South Campus, Benito Juarez Road, New Delhi-110021 (India); Gupta, Shubhra [Sri Venkateswara College, University of Delhi, New Delhi-110021 (India); Natasha [Maharaja Agrasen College, University of Delhi-110053 (India)

    2016-05-06

    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.

  18. 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.

  19. Dissociation behavior of protons incorporated in yttrium doped barium zirconate

    Science.gov (United States)

    Ishiyama, T.; Kishimoto, H.; Develos-Bagarinao, K.; Yamaji, K.; Yamaguchi, T.; Fujishiro, Y.

    2017-08-01

    The dissociation behavior of protons incorporated in yttrium-doped barium zirconate (BZY20) was investigated via combination of in-situ diffuse reflectance Fourier transform infrared spectroscopy (FT-IR) and evolved gas analysis. The vicinities of dopant or host ions were considered as sites of proton dissolution. The temperature dependence of the dissociation of protons from each site was evaluated. Protons which were considered to have dissolved in the vicinity of dopant ions were easily removed and dissociated as water. On the other hand, those which dissolved in the vicinity of host ions were dissociated as hydrogen at high temperatures. Such dissociation behavior was also detected after using D2O saturated gas for pre-treatment. These results suggest that some protons which dissolved in the perovskite oxide could dissociate as hydrogen without forming oxygen vacancies. (131words)

  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. Sorptive separation of yttrium and cerium on a weakly basic anionite

    Science.gov (United States)

    Cheremisina, O. V.; Ponomareva, M. A.; Chirkst, D. E.; Lobacheva, O. L.; Shul'gin, I. A.

    2015-01-01

    The sorption of complex yttrium ions with Trilon B onto the weakly basic anionite D-403 in nitrate form from an acidic medium at pH 3 with constant ionic strength (NaNO3, 1 mol/kg) is investigated. A thermodynamic evaluation of the sorption isotherm of anionic yttrium complexes is performed using a method based on the linearization of the equation of the law of active mass, modified for ionic exchange reactions. The ionic exchange constant, the Gibbs free energy of ionic exchange, the capacity of the anionite, and the sorption limit of ethylenediaminetetraacetatoyttrate ions (EDTA yttrate ions) are calculated. Using a frontal version of ion exchange chromatography, cerium and yttrium are separated on D-403 anionite with a fraction of pure yttrium at the column outlet of no less than 30%.

  3. 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.

  4. Synthesis,structure and catalytic behavior of yttrium complexes bearing a diaminobis(phenolate) ligand

    Institute of Scientific and Technical Information of China (English)

    SONG FengKui; YAN ChunHui; SUN HongMei; YAO YingMing; SHEN Qi; ZHANG Yong

    2009-01-01

    Yttrium complexes stabilized by a diaminobis(phenolate) ligand were synthesized and their catalytic behavior was explored. Reaction of YCI3 with 1 equiv of LNa2 [L=Me2NCH2CH2N{CH2-(2-O-C6H2-tBu2-3,5)}2]gave the yttrium chloride LYCI(THF) (1) in 92% yield. Complex 1 can be used as starting material to prepare the yttrium amido derivative. Complex 1 reacted with 1 equiv of LiNPh2 in THF to afford the expected yttrium amido complex LYNPh2 (2) in high yield. Both of complexes 1 and 2 have been well detected by elemental analysis,NMR spectra and single-crystal X-ray analysis. It was found that complex 2 can efficiently initiate the ring-opening polymerization of L-lactide and ε-caprolactone,and a controlled manner is observed in the former case.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-15

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

  6. Optical constants of yttrium-iron garnet single-crystal film structures

    Science.gov (United States)

    Sobol, V. R.; Volchik, T. V.; Arabei, S. M.; Korzun, B. V.; Kalanda, N. A.

    2009-03-01

    Light-attenuation spectra of yttrium-iron garnet single-crystal film structures grown on a gallium-gadolinium garnet substrate by liquid-phase epitaxy from the undercooled solution in the melt have been studied and compared with those of bulk yttrium-iron garnet samples. The calculated optical constants are discussed taking into account the influence of crystal field on the splitting of the energy states of iron ions in the film samples.

  7. Morpho-structural and luminescent investigations of niobium activated yttrium tantalate powders

    Energy Technology Data Exchange (ETDEWEB)

    Hristea, Amalia [' Raluca Ripan' Institute for Research in Chemistry, Fantanele 30, R-400294 Cluj-Napoca (Romania); Faculty of Chemistry and Chemical Engineering, ' Babes-Bolyai' University, 11 Arany Janos, 400028 Cluj-Napoca (Romania)], E-mail: amaliahristea@gmail.com; Popovici, Elisabeth-Jeanne; Muresan, Laura [' Raluca Ripan' Institute for Research in Chemistry, Fantanele 30, R-400294 Cluj-Napoca (Romania); Stefan, Maria [' Raluca Ripan' Institute for Research in Chemistry, Fantanele 30, R-400294 Cluj-Napoca (Romania); Faculty of Chemistry and Chemical Engineering, ' Babes-Bolyai' University, 11 Arany Janos, 400028 Cluj-Napoca (Romania); Grecu, Rodica [' Raluca Ripan' Institute for Research in Chemistry, Fantanele 30, R-400294 Cluj-Napoca (Romania); Johansson, Anders [Angstrom Laboratory, Department of Materials Chemistry, Uppsala University, Box 538, 751 21 Uppsala (Sweden); Boman, Mats [Angstrom Laboratory, Department of Materials Chemistry, Uppsala University, Box 538, 751 21 Uppsala (Sweden)], E-mail: mats.boman@mkem.uu.se

    2009-03-05

    Yttrium tantalate-based phosphors are a class of efficient luminescent materials used in medical imaging applications. The paper presents the influence of activator concentration, firing regime and flux nature on the crystalline structure, morphology and luminescent characteristics of niobium activated yttrium tantalate powders. Phosphors samples were prepared by solid-state reaction route and their properties were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) measurements and scanning electron microscopy (SEM)

  8. Pulsed Laser Deposition of YBCO With Yttrium Oxide Buffer Layers (Postprint)

    Science.gov (United States)

    2012-02-01

    AFRL-RZ-WP-TP-2012-0092 PULSED LASER DEPOSITION OF YBCO WITH YTTRIUM OXIDE BUFFER LAYERS (POSTPRINT) Paul N. Barnes, Timothy J. Haugan...Paper Postprint 01 January 2002 – 01 January 2004 4. TITLE AND SUBTITLE PULSED LASER DEPOSITION OF YBCO WITH YTTRIUM OXIDE BUFFER LAYERS (POSTPRINT...Textured metallic substrate based HTS coated conductors with the YBCO /CeO2/YSZ/CeO2/Ni architecture have already been shown to exhibit high current

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-01

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

  10. Strengthening and Toughening Effect of Yttrium on Al2O3/TiCN Ceramic Tool Material

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The strengthening and toughening effect of yttrium on an advanced Al2O3/TiCN ceramic tool material was studied by means of SEM, TEM and energy spectrum analysis. Results showed that yttrium can react with the impurity elements such as W, Fe, Cr, etc. Thus, the interfaces between ceramic phases are purified and the interfacial binding strength is increased. As a result, the mechanical properties of the Al2O3/TiCN ceramic tool material reinforced with yttrium are improved significantly. In addition, the effect of yttrium on particle strengthening of the solid solution TiCN may partly contribute to the improvement of the mechanical properties.

  11. The 4f-5d luminescence transitions in cerium-doped LuF3

    Science.gov (United States)

    Guerbous, L.; Krachni, O.

    Emission and excitation spectra of the Ce3+ ion in LuF3 single crystal were measured at 77 K. The broad bands observed in these spectra were attributed to the parity-allowed electric-dipole 4f ← 5d transitions within Ce3+ ion. No zero-phonon lines were observed, which is indicative of a strong electron-phonon coupling in this host. It is shown that Ce3+ 5d excited configuration splits into five crystal-field components in LuF3. The influence of the crystalline environment on the position of the lowest Ce3+ 5d level is investigated. The energy of the lowest level of the 4fN-15d excited configuration was predicted for all the trivalent rare earth ions embedded in LuF3. Positions of crystal field spitting levels of 4fN-15d configuration relative to the host electronic bands were discussed.

  12. Cerium-doped barium halide scintillators for x-ray and γ-ray detections

    NARCIS (Netherlands)

    Selling, J.; Schweizer, S.; Birowosuto, M.D.; Dorenbos, P.

    2007-01-01

    Single crystals of Ce-activated BaCl2, BaBr2, and BaI2 were investigated under x-ray and γ-ray excitation. The Ce3+-related x-ray excited luminescence in BaBr2 shifts significantly to longer wavelengths upon increasing the doping level from 0.1% to 1%. In Ce-activated BaCl2 only a slight shift can b

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

    CERN Document Server

    Auffray, Etiennette; Dafinei, I; Fay, J; Lecoq, P; Mares, J A; Martini, M; Mazé, G; Meinardi, F; Moine, B; Nikl, M; Pédrini, C; Poulain, M; Schneegans, M; Tavernier, Stefaan; Vedda, A

    1996-01-01

    The article is an overview of the research activity performed in the framework of the Crystal Clear Collaboration to produce scintillating glasses. The manufacturing of heavy metal fluoride glasses doped with Ce3+ is discussed. The luminescence and scintillation characteristics as well as the radiation hardness properties are extensively studied in the case of Ce doped fluorohafnate , found to be the most convenient glass scintillator for high energy physics applications.

  14. Fabrication and characterization of cerium-doped terbium gallium garnet with high magneto-optical properties.

    Science.gov (United States)

    Chen, Zhe; Hang, Yin; Yang, Lei; Wang, Jun; Wang, Xiangyong; Hong, Jiaqi; Zhang, Peixiong; Shi, Chunjun; Wang, Yaqi

    2015-03-01

    High optical quality (Tb((1-x))Ce(x))₃Ga₅O₁₂ (TCGG) single crystal has been grown by the Czochralski method. The optical and magneto-optical properties of the TCGG are analyzed in detail and the Verdet constant (V) of TCGG is compared with that of undoped terbium gallium garnet (TGG) crystal. TCGG presents a very high transmittance, particularly in the visible-near infrared (VIS-NIR) region, and its V is obviously larger than that of TGG in the VIS-NIR region. The figure of merit and optical features point out the superior characteristics of TCGG with respect to TGG.

  15. Grain Growth Behavior, Tensile Impact Ductility, and Weldability of Cerium-Doped Iridium Alloys

    Energy Technology Data Exchange (ETDEWEB)

    McKamey, C.G.

    2002-05-28

    An iridium alloy doped with small amounts of cerium and thorium is being developed as a potential replacement for the iridium-based DOP-26 alloy (doped with thorium only) that is currently used by the National Aeronautics and Space Administration (NASA) for cladding and post-impact containment of the radioactive fuel in radioisotope thermoelectric generator (RTG) heat sources which provide electric power for interplanetary spacecraft. This report summarizes results of studies conducted to date under the Iridium Alloy Characterization and Development subtask of the Radioisotope Power System Materials Production and Technology Program to characterize the properties of the iridium-based alloy (designated as DOP-40) containing both cerium and thorium. Included within this report are data on grain growth of sheet material in vacuum and low-pressure oxygen environments, grain growth in vacuum of the clad vent set cup material, weldability, and the effect of grain size and test temperature on tensile properties. Where applicable, data for the DOP-26 alloy are included for comparison. Both grain size and grain-boundary cohesion affect the ductility of iridium alloys. In this study it was found that cerium and thorium, when added together, refine grain size more effectively than when thorium is added by itself (especially at high temperatures). In addition, the effect of cerium additions on grain-boundary cohesion is similar to that of thorium. Mechanical testing at both low ({approx} 10{sup -3}s{sup -1}) and high ({approx} 10{sup -3}s{sup -1}) strain rates showed that the Ce/Th-doped alloys have tensile ductilities that are as good or better than the DOP-26 alloy. The general conclusion from these studies is that cerium can be used to replace some of the radioactive thorium currently used in DOP-26 while maintaining or improving its metallurgical properties. The current DOP-26 alloy meets all requirements for cladding the radioactive fuel in the RTG heat source, but the new DOP-40 alloy could serve as a back-up alloy to be used if the costs of refining, handling, and transporting DOP-26 become prohibitively high.

  16. Cerium-doped barium halide scintillators for x-ray and γ-ray detections

    NARCIS (Netherlands)

    Selling, J.; Schweizer, S.; Birowosuto, M.D.; Dorenbos, P.

    2007-01-01

    Single crystals of Ce-activated BaCl2, BaBr2, and BaI2 were investigated under x-ray and γ-ray excitation. The Ce3+-related x-ray excited luminescence in BaBr2 shifts significantly to longer wavelengths upon increasing the doping level from 0.1% to 1%. In Ce-activated BaCl2 only a slight shift can

  17. Studies on luminescence from a cerium-doped strontium stannate phosphor.

    Science.gov (United States)

    Karabulut, Yüksel; Ayvacikli, Mehmet; Canimoglu, Adil; Garcia Guinea, Javier; Can, Nurdogan

    2015-06-01

    The crystal structure and morphology of Ce(3+) -doped SrSnO3 materials prepared using the solid-state reaction method were extensively characterized using experimental techniques. X-Ray diffraction results show that the cerium substitution of strontium does not change the structure of the strontium stannate. Raman spectroscopy was used to investigate the microstructures and lattice vibrations. Environmental scanning electron microscopy images showed that phosphors aggregate and their particles form irregular shapes. SrSnO3 exhibits an intense green emission with a broad band originating from the 5d(1)  → 4f(1) transition of cerium. It was observed that, after exposure to beta-irradiation, the glow curve of this material has two broad thermoluminescence peaks, one centered at ~ 127°C and the other at ~ 245°C for a heating rate of 5 K/s. The kinetic parameters, which include the frequency factor and the activation energy of the material, were calculated using Chen's method, after beta-irradiation. The fading and reusability of the phosphor were also studied and it was found that the phosphor is suitable for radiation dosimetry. Copyright © 2014 John Wiley & Sons, Ltd.

  18. Gold-supported cerium-doped NiOx catalysts for water oxidation

    Science.gov (United States)

    Ng, Jia Wei Desmond; García-Melchor, Max; Bajdich, Michal; Chakthranont, Pongkarn; Kirk, Charlotte; Vojvodic, Aleksandra; Jaramillo, Thomas F.

    2016-05-01

    The development of high-performance catalysts for the oxygen-evolution reaction (OER) is paramount for cost-effective conversion of renewable electricity to fuels and chemicals. Here we report the significant enhancement of the OER activity of electrodeposited NiOx films resulting from the combined effects of using cerium as a dopant and gold as a metal support. This NiCeOx-Au catalyst delivers high OER activity in alkaline media, and is among the most active OER electrocatalysts yet reported. On the basis of experimental observations and theoretical modelling, we ascribe the activity to a combination of electronic, geometric and support effects, where highly active under-coordinated sites at the oxide support interface are modified by the local chemical binding environment and by doping the host Ni oxide with Ce. The NiCeOx-Au catalyst is further demonstrated in a device context by pairing it with a nickel-molybdenum hydrogen evolution catalyst in a water electrolyser, which delivers 50 mA consistently at 1.5 V over 24 h of continuous operation.

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

    CERN Document Server

    McGrath, B; Van de Voorde, M H

    1976-01-01

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

  20. Dielectric studies on cerium doped BaLa2Ti3O10

    Directory of Open Access Journals (Sweden)

    Parshuram B. Abhange

    2015-12-01

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

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

    Directory of Open Access Journals (Sweden)

    P Kameli

    2015-01-01

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

  2. Cerium doped red mud catalytic ozonation for bezafibrate degradation in wastewater: Efficiency, intermediates, and toxicity.

    Science.gov (United States)

    Xu, Bingbing; Qi, Fei; Sun, Dezhi; Chen, Zhonglin; Robert, Didier

    2016-03-01

    In this study, the performance of bezafibrate (BZF) degradation and detoxification in the aqueous phase using cerium-modified red mud (RM) catalysts prepared using different cerium sources and synthesis methods were evaluated. Experimental results showed that the surface cerium modification was responsible for the development of the catalytic activity of RM and this was influenced by the cerium source and the synthesis method. Catalyst prepared from cerium (IV) by precipitation was found to show the best catalytic activity in BZF degradation and detoxification. Reactive oxygen species including peroxides, hydroxyl radicals, and super oxide ions were identified in all reactions and we proposed the corresponding catalytic reaction mechanism for each catalyst that prepared from different cerium source and method. This was supported by the intermediates profiles that were generated upon BZF degradation. The surface and the structural properties of cerium-modified RM were characterized in detail by several analytical methods. Two interesting findings were made: (1) the surface texture (specific surface area and mesoporous volume) influenced the catalytic reaction pathway; and (2) Ce(III) species and oxygen vacancies were generated on the surface of the catalyst after cerium modification. This plays an important role in the development of the catalytic activity.

  3. Upconversion luminescence of cerium doped CoWO{sub 4} nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, Uma, E-mail: us00@yahoo.com [Department of Physics, Goa University, GOA-403 206 (India); Naik, S.J. [Department of Chemistry, Goa University, GOA-403 206 (India); Tangsali, R.B. [Department of Physics, Goa University, GOA-403 206 (India); Salker, A.V. [Department of Chemistry, Goa University, GOA-403 206 (India)

    2013-02-15

    In this paper we report the bluish green upconversion intrinsic photoluminescence (PL) observed at room temperature (RT) 300 K for the nanorange (27-50 nm) Ce{sup 3+} doped and undoped CoWO{sub 4} powder samples sintered in air at 600 Degree-Sign C. Excitation by Xenon lamp at 600 nm was done and the emission was observed between 400 nm and 550 nm. Co{sub 1-x}Ce{sub x}WO{sub 4} [where x=0.00, 0.02, and 0.03] compounds were prepared by the solution based co-precipitation method and characterised by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The surface morphology of the compounds was examined by scanning electron microscopy (SEM) techniques. Optical absorption and photoluminescence behaviour of the compounds in the rigid matrix were studied. High emission intensity and easy preparation make these systems potential candidates for application as luminescent materials. - Highlights: Black-Right-Pointing-Pointer Ce{sup 3+} doped CoWO{sub 4} nanosamples were prepared by the co-precipitation method. Black-Right-Pointing-Pointer Characterised by XRD, TEM, SEM and XPS. Black-Right-Pointing-Pointer Upconversion intrinsic luminescence observed for nanosamples. Black-Right-Pointing-Pointer Mechanism for the upconverted emission is explained. Black-Right-Pointing-Pointer No upconverted luminescence observed for bulk samples.

  4. Broadly tunable ultraviolet miniature cerium-doped LiLuF lasers.

    Science.gov (United States)

    Liu, H; Spence, D J; Coutts, D W; Sato, H; Fukuda, T

    2008-02-04

    Ultraviolet (UV) miniature cerium fluoride lasers have been demonstrated using a low cost, frequency-quadrupled microchip Nd:YAG pump laser. The use of miniature laser cavities was shown to significantly improve the laser performance in the low pump power region. We have achieved slope efficiencies up to 70% and pump thresholds as low as 100 nJ. Continuous tuning from 306 nm to 338 nm was achieved using a Brewster angle prism.

  5. Characterization of the alumina film with cerium doped on the iron-aluminide diffusion coating

    Energy Technology Data Exchange (ETDEWEB)

    Zhan, Q., E-mail: zhanqin1983@163.com; Yang, H.G.; Zhao, W.W.; Yuan, X.M.; Hu, Y.

    2013-11-15

    An iron-aluminide layer with a thin alumina film on the top as a composite tritium permeation barrier (TPB) coating was characterized under different oxidation conditions. The TPB coating was prepared initially on a China Low Activation Ferritic-Martensitic (CLAM) steel by a pack cementation aluminizing process and then an alumina film was formed on the surface of this iron-aluminide diffusion layer by an oxidizing process. To modify the properties of the FeAl/Al{sub 2}O{sub 3} composite TPB coatings, the rare earth element (cerium) was introduced as a dopant while oxidizing. Characterization showed that a continuous oxide scale with a thickness of about 300–400 nm was formed on the FeAl diffusion layer. The film was mainly composed of Al{sub 2}O{sub 3} doped with a little CeO{sub 2}. In addition, the concentration of α-Al{sub 2}O{sub 3} increased with elevated temperature while oxidizing. The phase transformation behavior of alumina scale on the surface of an iron-aluminide layer was studied in this paper.

  6. Pressure-induced luminescence of cerium-doped gadolinium gallium garnet crystal

    Science.gov (United States)

    Kaminska, A.; Duzynska, A.; Berkowski, M.; Trushkin, S.; Suchocki, A.

    2012-04-01

    Studies of the spectroscopic properties of Ce3+ dopant in bulk Gd3Ga5O12:Ce crystal under pressure are presented. In spite of strong intershell 4f→5d absorption bands at ambient pressure, the cerium luminescence in Gd3Ga5O12 is entirely quenched even at low temperature. It has been shown that applying pressure allows for recovery of the 5d→4f radiative transitions. Further increase of pressure improves the emission efficiency. This effect is analyzed in terms of two possible phenomena: (i) by pressure-induced electronic crossover of the excited 5d energy level of the Ce3+ with the conduction band bottom of the host crystal, and (ii) by decrease of electron-lattice coupling with increasing pressure, resulting in reduction of the Stokes shift and nonradiative transitions between the low vibrational levels of the 5d state and high vibrational levels of the ground 4f state. The results of high-pressure absorption and luminescence measurements point out that the ambient-pressure luminescence quenching is caused by the donor-like charge transfer processes due to the resonant location of the Ce3+ 5d electronic levels with respect to the host conduction band. In such a situation, the ionization of Ce3+ to Ce4+ occurs, accompanied by large lattice relaxation, which enables the nonradiative recombination to the Ce 4f state. The pressure-induced approach of the conduction-band bottom of the host crystal by the excited 5d energy level of the Ce3+ results in mixing between conduction band states and the 5d state, and the broadband luminescence from this mixed state is observed at pressures from 30 up to about 60 kbar. Then, for pressures exceeding 60 kbar, this luminescence is replaced by the classic Ce3+5d→4f transitions. Using a simple anticrossing model and configuration coordinate model in the appropriate pressure range, quantitative description of the system has been carried out, and the pressure-induced decrease of electron-lattice coupling has been shown.

  7. 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.

  8. Optical and structural characterization of yttrium calcium borate glasses

    Science.gov (United States)

    Santos, Cristiane; Meneses, Domingos D. S.; Echegut, Patrick; Neuville, Daniel R.; Hernandes, Antonio C.; Ibanez, Alain

    2010-03-01

    Structural and optical properties of new stable glasses in the Y2O3 -- CaO -- B2O3 system, containing the same Y/Ca ratio as the YCa4O(BO3)3 (YCOB) crystal, were determined from Raman and reflectance infrared spectroscopy [1]. We have obtained the optical functions using a dielectric function model and their evolution with composition are associated with an increase in the number of non-bridging oxygen and to calcium/yttrium oxides content with the formation of pentaborate, metaborate, orthoborate and pyroborate groups. The orthoborate and pyroborate signatures increase with increasing the modifier cations. Refractive indexes values (from 1.597 to 1.627 at λ = 2 μm) are in good agreement with those of the YCOB crystal, an indication that these glasses are potential candidates for doping with rare-earth ions for optical applications. [4pt] [1] C. N. Santos, D.D.S. Meneses, P. Echegut, D. R. Neuville, A. C. Hernandes, A. Ibanez, Appl. Phys. Lett. 94, 151901(2009).

  9. Optical properties of ytterbium-doped yttrium oxide ceramics

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-15

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

  10. Ab initio calculations of yttrium nitride: structural and electronic properties

    Energy Technology Data Exchange (ETDEWEB)

    Zerroug, S.; Ali Sahraoui, F. [Universite Ferhat Abbas, Laboratoire d' Optoelectronique et Composants, Departement de Physique, Setif (Algeria); Bouarissa, N. [King Khalid University, Department of Physics, Faculty of Science, P.O. Box 9004, Abha (Saudi Arabia)

    2009-11-15

    Using first principles total energy calculations within the full-potential linearized augmented plane wave method, we have studied the structural and electronic properties of yttrium nitride (YN) in the three phases, namely wurtzite, caesium chloride and rocksalt structures. The calculations are performed at zero and under hydrostatic pressure. In agreement with previous findings, it is found that the favored phase for YN is the rocksalt-like structure. We predict that at zero pressure YN in the rocksalt structure is a semiconductor with an indirect bandgap of 0.8 eV. A phase transition from a rocksalt to a caesium chloride structure is found to occur at {proportional_to}134 GPa. Besides, a transition from an indirect ({gamma}-X) bandgap semiconductor to a direct (X-X) one is predicted at pressure of {proportional_to}84 GPa. For the electron effective mass of rocksalt YN, these are the first results, to our knowledge. The information derived from the present study may be useful for the use of YN as an active layer in electronic devices such as diodes and transistors. (orig.)

  11. 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.

  12. 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.

  13. Studies on the synthesis of europium activated yttrium oxide by wet-chemical method

    Energy Technology Data Exchange (ETDEWEB)

    Muresan, Laura [Raluca Ripan Institute for Research in Chemistry, Fantanele 30, 400294 Cluj-Napoca (Romania)], E-mail: laura_muresan2003@yahoo.com; Popovici, Elisabeth-Jeanne; Grecu, Rodica [Raluca Ripan Institute for Research in Chemistry, Fantanele 30, 400294 Cluj-Napoca (Romania); Tudoran, Lucian Barbu [Electronic Microscopy Center, Babes-Bolyai University, 400028 Cluj-Napoca (Romania)

    2009-03-05

    Europium activated yttrium oxide phosphor powders (Y{sub 2}O{sub 3}:Eu{sup 3+}) were prepared from yttrium-europium precursors obtained by wet-chemical method. With this purpose in view, precursors were prepared using the reagent simultaneous addition SimAdd technique from yttrium-europium nitrate and chloride as rare-earth supplier and urea, ammonium oxalate, ammonium carbonate and oxalic acid as precipitating agents. Precursors, obtained under controlled concentration, temperature and pH conditions, were fired at 1200 deg. C in order to generate Y{sub 2}O{sub 3}:Eu{sup 3+} phosphor powders. Yttrium-europium precursors and Y{sub 2}O{sub 3}:Eu{sup 3+} phosphor powders were investigated by FTIR, TGA-DTA, X-ray diffraction (XRD), scanning electronic microscopy (SEM) and photoluminescence spectroscopy (PL) in order to put in evidence the influence of the quality of yttrium-europium precursors obtained by wet-chemical method, using the SimAdd technique on the properties of Y{sub 2}O{sub 3}:Eu{sup 3+} phosphor powders.

  14. 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.

  15. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hua, Guomin [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2G6 (Canada); Ahmadi, Hojat [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2G6 (Canada); Department of Mechanics of Agricultural Machinery, College of Agriculture and , Natural Resources, University of Tehran, Karaj (Iran, Islamic Republic of); Nouri, Meisam [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2G6 (Canada); Li, Dongyang, E-mail: dongyang.li@ualberta.ca [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2G6 (Canada)

    2015-01-15

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

  17. Preparation of nanosized yttrium doped CeO2 catalyst used for photocatalytic application

    Directory of Open Access Journals (Sweden)

    A. Akbari-Fakhrabadi

    2015-09-01

    Full Text Available In the present work, the pure CeO2 and yttrium doped CeO2 nanopowders were synthesized by the nitrate-fuel self-sustaining combustion method and calcined at 700 °C for 2 h. X-ray diffraction (XRD and high resolution electron transmission microscopy (HRTEM results demonstrated a cubic fluorite with high purity and the crystallite sizes less than 20 nm calculated from Scherrer’s formula. The BET specific surface area of yttrium doped CeO2 samples showed high values than those of pure CeO2. The photocatalytic activity of yttrium doped CeO2 showed high degradation of Rhodamine B solution under visible light illumination.

  18. Synthesis of yttrium doped nanocrystalline ZnO and its photocatalytic activity in methylene blue degradation

    OpenAIRE

    2016-01-01

    Yttrium doped zinc oxide was prepared by microwave irradiation of Y (NO3)3·6H2O and Zn(NO3)2·4H2O as precursors, in ethanol–water medium. Highly polar ethanol–water medium (30/70, v/v) with hexamine and urea assist the formation of ZnO nuclei very rapidly in a specific fashion. Furthermore, Y3+ ions infiltration into Zn(OH)2 precipitate was facilitated by microwaves (2.45 GHz, 950 W). Yttrium doped nanocrystalline ZnO (ZnO-99 and ZnO-95) was formed with 1 and 5 mol% yttrium precursor. The pow...

  19. Fractionation of yttrium and holmium during basaltic soil weathering

    Science.gov (United States)

    Thompson, Aaron; Amistadi, Mary Kay; Chadwick, Oliver A.; Chorover, Jon

    2013-10-01

    The anomalously low affinity of yttrium (Y) for iron (Fe) (oxyhydr)oxides relative to lanthanides with similar ionic radius (e.g., Ho) has been demonstrated in experiments with isolated Fe minerals and in a variety of marine systems that contain high concentrations of solid phase Fe. However, it has not previously been demonstrated to occur during soil genesis, despite the common observation that many soils become enriched in Fe over time. We hypothesized that Y would become progressively depleted in soils relative to Ho with increased weathering. Since, trivalent Y has an anomalously low Misono softness relative to other trivalent ions included in the rare earth element and yttrium group (REY3+), we also investigated whether soil REY fractionation reflects variation in Misono softness. To test this, we measured trends in total REY concentrations for Hawaiian soils derived from basaltic parent materials aged 0.3-4100 ky, and measured REYs released from the same samples during short-time (3 h) dissolution experiments conducted as part of a previous investigation linking dissolution with surface charge properties (Chorover et al., 2004). The chondrite-normalized Y/Ho ratios in the parent Hawaiian basalt (Chond[Y/Ho] = 0.998) and continental dust (Chond[Y/Ho] = 0.994) inputs are remarkably similar, and thus we can interpret deviations from Chond[Y/Ho] ∼ 1.0 to result from soil biogeochemical processes and not source mixing. Between 0.3 and 20 ky, the Chond[Y/Ho] ratio of the subsurface soils decreased from 0.96 ± 0.07(2σ) to 0.71 ± 0.05, and then remained unchanged across the rest of the weathering sequence. In contrast, the Chond[Y/Ho] ratio of the surface soils decreased from 0.99 ± 0.07 to 0.76 ± 0.05 at 150 ky and then, most likely due to continued dust inputs, increased to 1.04 ± 0.07 in the oldest soils. Analysis of the short-time dissolution experiments revealed preferential release of Y relative to Ho (and also La relative Pr) at intermediate pH where

  20. 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.

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

    Science.gov (United States)

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

    2016-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-15

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

  3. 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.

  4. Nanostructured yttrium aluminum garnet powders synthesized by co-precipitation method using tetraethylenepentamine

    Institute of Scientific and Technical Information of China (English)

    李先学; 王文菊

    2009-01-01

    Tetraethylenepentamine(C8H23N5,TEPA) has been used as a novel precipitant to synthesize yttrium aluminum garnet(Y3Al5O12,YAG) precursor from a mixed solution of aluminum and yttrium nitrates via a normal-strike co-precipitation method without controlling the pH value during precipitation process.The original precursor was analyzed by thermogravimetry/differential scanning calorimetry(TG/DSC).The evolution of phase composition and micro-structure of the as-synthesized YAG powders were characterized by X-ray ...

  5. EXTRACTION KINETICS OF YTTRIUM WITH PURIFIED CYANEX 923 FROM NITRATE MEDIUM

    Institute of Scientific and Technical Information of China (English)

    H. Tong; Y.G. Wang; J.H. Lei; D.Q. Li; P. Tang

    2003-01-01

    Mass transfer and extraction kinetics of yttrium with the purified Cyanex 923 in nheptane from nitrate medium have been investigated by using a constant interfacial cell with laminar flow at 298K. The interfacial adsorption properties of purified Cyanex 923-heptane-0. 20mol/L (H, Na)NO3 were studied at 298K. The experimental results show that the mass transfer is controlled by diffusion and the chemical reactions are carried out in the interfacial zone. The extraction rates of yttrium were measured at different chemical compositions by varying ionic strength, pH values and the purified Cyanex 923 concentrations. The initial extraction rate equations were obtained.

  6. 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.

  7. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-11-01

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

  9. The nature of photoinduced changes in the magnetostriction of yttrium-iron garnet single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Vorob' eva, N. V., E-mail: vnv@anrb.ru [Russian Academy of Sciences, Institute of Molecular and Crystals Physics (Russian Federation)

    2011-05-15

    A model of the occurrence of photoinduced changes in linear magnetostriction is proposed based on a complex experimental study of magnetostrictive strains in yttrium-iron garnets Y{sub 3}Fe{sub 5}O{sub 12} with low contents of different impurities. Analytical expressions for calculating the magnetostriction in yttrium-iron garnet single crystals with different types of doping are presented. The correlation of the photoinduced change in the magnetostriction with the crystallographic features of the samples is demonstrated. The changes in the magnetostriction constants are analyzed quantitatively for samples prepared in different ways.

  10. Magnetophotonic crystal with cerium substituted yttrium iron garnet and enhanced Faraday rotation angle.

    Science.gov (United States)

    Yoshimoto, Takuya; Goto, Taichi; Isogai, Ryosuke; Nakamura, Yuichi; Takagi, Hiroyuki; Ross, C A; Inoue, M

    2016-04-18

    Magnetophotonic crystals (MPCs) comprising cerium-substituted yttrium iron garnet (CeYIG) sandwiched by two Bragg mirrors were fabricated by vacuum annealing. CeYIG was deposited on Bragg mirrors at room temperature and annealed in 5 Pa of residual air. No ceria or other non-garnet phases were detected. Cerium 3 + ions substituted on the yttrium sites and no cerium 4 + ions were found. The Faraday rotation angle of the MPC was -2.92° at a wavelength of λ = 1570 nm was 30 times larger than that of the CeYIG film. These results showed good agreement with calculated values derived using a matrix approach.

  11. Two-photon-absorption cross section of Nd3+ in yttrium aluminum garnet and yttrium lithium fluoride near 1.06 μm

    Science.gov (United States)

    Chase, L. L.; Payne, Stephen A.

    1986-12-01

    We have measured the spectrally integrated two-photon-absorption (TPA) cross sections for the 4I9/2--> 4G7/2 transitions of Nd3+ and obtained values of 1.2×10-40 and 0.15×10-40 cm4 for Nd3+-doped yttrium aluminum garnet (YAG) and yttrium lithium fluoride (YLF), respectively. These results are in satisfactory agreement with theoretical calculations based on the properties of Nd3+ free-ion wave functions. The difference between YAG and YLF, however, is not accounted for by the free-ion theory and suggests that the intermediate-state energies and wave functions are considerably host dependent. In addition, we conclude, based on our measurements, that rare-earth TPA will not contribute significantly to either losses or the nonlinear refractive index in typical laser media employing rare-earth ions.

  12. Effect of yttrium addition on water-gas shift reaction over CuO/CeO2 catalysts

    Institute of Scientific and Technical Information of China (English)

    SHE Yusheng; LI Lei; ZHAN Yingying; LIN Xingyi; ZHENG Qi; WEI Kemei

    2009-01-01

    This paper presented a study on the role of yttrium addition to CuO/CeO2 catalyst for water-gas shift reaction. A single-step co-precipitation method was used for preparation of a series of yttrium doped CuO/CeO2 catalysts with yttrium content in the range of 0-5wt.%. Properties of the obtained samples were characterized and analyzed by X-ray diffraction (XRD), Raman spectroscopy, H2-TPR, cyclic voltammetry (CV) and the BET method. The results revealed that catalytic activity was increased with the yttrium content at first, but then decreased with the further increase of yttrium content. Herein, CuO/CeO2 catalyst doped with 2wt.% of yttrium showed the highest catalytic activity (CO conversion reaches 93.4% at 250℃) and thermal stability for WGS reaction. The catalytic activity was correlated with the surface area, the area of peak y of H2-TPR profile (I.e., the reduction of surface copper oxide (crystalline forms) interacted with surface oxygen vacancies on ceria), and the area of peak C2 and A1 (Cu0→Cu2+ in cyclic voltammetry process), respectively. Besides, Raman spectra provided evidences for a synergistic Cu-Ovacancy interaction, and it was indicated that doping yttrium may facilitate the formation of oxygen vacancies on ceria.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-15

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

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

    Directory of Open Access Journals (Sweden)

    Suchopár M.

    2017-01-01

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

  15. The effect of yttrium and thorium on the oxidation behavior of Ni-Cr-Al alloys

    Science.gov (United States)

    Kumar, A.; Nasrallah, M.; Douglass, D. L.

    1974-01-01

    The effect of quaternary additions of 0.5% Y, 0.5 and 1.0% Th to a base alloy of Ni-10CR-5Al on the oxidation behavior and mechanism was studied during oxidation in air over the range of 1000 to 1200 C. The presence of yttrium decreased the oxidation kinetics slightly, whereas, the addition of thorium caused a slight increase. Oxide scale adherence was markedly improved by the addition of the quaternary elements. Although a number of oxides formed on yttrium containing alloys, quantitative X-ray diffraction clearly showed that the rate-controlling step was the diffusion of aluminum through short circuit paths in a thin layer of alumina that formed parabolically with time. Although the scale adherence of the yttrium containing alloy was considerably better than the base alloys, spalling did occur that was attributed to the formation of the voluminous YAG particles which grew in a mushroom-like manner, lifting the protective scale off the subrate locally. The YAG particles formed primarily at grain boundaries in the substrate in which the yttrium originally existed as YNi9.

  16. Sol-Gel Synthesis and Antioxidant Properties of Yttrium Oxide Nanocrystallites Incorporating P-123

    Directory of Open Access Journals (Sweden)

    Rebeca Mellado-Vázquez

    2014-09-01

    Full Text Available Yttrium oxide (Y2O3 nanocrystallites were synthesized by mean of a sol-gel method using two different precursors. Raw materials used were yttrium nitrate and yttrium chloride, in methanol. In order to promote oxygen vacancies, P-123 poloxamer was incorporated. Synthesized systems were heat-treated at temperatures from 700 °C to 900 °C. Systems at 900 °C were prepared in the presence and absence of P-123 using different molar ratios (P-123:Y = 1:1 and 2:1. Fourier transform infrared spectroscopy (FTIR results revealed a characteristic absorption band of Y–O vibrations typical of Y2O3 matrix. The structural phase was analyzed by X-ray diffraction (XRD, showing the characteristic cubic phase in all systems. The diffraction peak that presented the major intensity corresponded to the sample prepared from yttrium chloride incorporating P-123 in a molar ratio of P-123:Y = 2:1 at 900 °C. Crystallites sizes were determined by Scherrer equation as between 21 nm and 32 nm. Antioxidant properties were estimated by 2,2-diphenyl-1-picrylhydrazyl (DPPH• assays; the results are discussed.

  17. Comparison of the excimer laser with the erbium yttrium aluminum garnet laser for applications in osteotomy

    Science.gov (United States)

    Li, Zhao-zhang; Van De Merwe, Willem P.; Reinisch, Lou

    1991-06-01

    The ablative removal of bone tissue and the accompanying acoustic wave have been studied in a liquid environment using an ultraviolet excimer laser (Argon Fluoride and Krypton Fluoride) and a mid-infrared Erbium Yttrium Aluminum Garnet (Er:YAG) laser

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

    NARCIS (Netherlands)

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

    2004-01-01

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

  19. On the synthesis of monopentamethylcyclopentadienyl derivatives of yttrium, lanthanum, and cerium

    NARCIS (Netherlands)

    Booij, Martin; Kiers, Niklaas H.; Heeres, Hero J.; Teuben, Jan H.

    1989-01-01

    Two routes leading to monopentamethylcyclopentadienyl-yttrium, -lanthanum and -cerium complexes have been explored. Transmetallation of LnCl3(THF)x with Cp*Li (Cp* = C5Me5) proved useful only in some particular cases. Acid-base reactions of homoleptic complexes LnR3 with Cp*H generally gave Cp*2LnR

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

    Science.gov (United States)

    Ghahramani, M R; Garibov, A A; Agayev, T N

    2014-09-01

    This paper reports on a new method to embed phosphorus particles into the matrix of yttrium aluminum silicate microspheres. Yttrium phosphorus glass microspheres about 20µm 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.

  3. 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...

  4. The effects of yttrium on the hydrogenation performance and surface properties of a ruthenium-supported catalyst

    Directory of Open Access Journals (Sweden)

    LAITAO LUO

    2005-12-01

    Full Text Available The effects of yttrium on the hydrogenation performance and surface properties of a Ru/sepiolite catalyst were studied. With CO2 methanation and CS2 poisoning as the testing reactons, TPR, TPD, XRD and CO chemisorption as the characterizations, the results showed that the presence of yttrium can increase the hydrogenation activity and anti-poisoning capacity of the Ru/sepiolite catalyst, which is due to a change of surface properties of the Ru/sepiolite. In the process of the catalytic reaction, the adjusting behavior of yttrium for the Ru/sepiolite catalyst aids in increasing the catalytic activity and anti-poisoning capacity of the catalyst.

  5. Variation of Eu{sup 3+} emissions in yttrium aluminum oxides controlled by amount of La{sup 3+} dopant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hwan, E-mail: kimjh@deu.ac.kr

    2017-01-15

    The nanophosphors of europium doped yttrium aluminum oxide were synthesized by a hydrothermal method. As the amount of La{sup 3+} ions substituted in yttrium sites was increased, the crystal structure was transformed from pure garnet to perovskite phase through the mixed phase of garnet and perovskite. Red emission centered at 618 nm wavelength radiated from a {sup 5}D{sub 0} → {sup 7}F{sub 2} of Eu{sup 3+} due to the forced electric dipole transition was remarkably enhanced by a factor 45, which is attributed to the phase transition of yttrium aluminum oxide by incorporation of La{sup 3+} ions.

  6. Effects of yttrium, aluminum and chromium concentrations in bond coatings on the performance of zirconia-yttria thermal barriers

    Science.gov (United States)

    Stecura, S.

    1980-01-01

    A cyclic furnace study was conducted on thermal barrier systems to evaluate the effects of yttrium, chromium and aluminum in nickel-base alloy bond coatings and the effect of bond coating thickness on yttria-stabilized zirconia thermal barrier coating life. Without yttrium in the bond coatings, the zirconia coatings failed very rapidly. Increasing chromium and aluminum in the Ni-Cr-Al-Y bond coatings increased total coating life. This effect was not as great as that due to yttrium. Increased bond coat thickness was also found to increase life.

  7. Yttrium (III chloride catalyzed Mannich reaction: An efficient procedure for the synthesis of β-amino carbonyl compounds

    Directory of Open Access Journals (Sweden)

    Venkateswarlu Yekkirala

    2014-12-01

    Full Text Available Yttrium (III chloride catalyzed Mannich reaction of aldehydes with ketones and amines in acetonitrile at reflux temperature to give various β-amino carbonyl compounds in very good yields.

  8. 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)

  9. Preparation and Characterization of Porous Yttrium Oxide Powders with High Specific Surface Area

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The porous cubic yttrium oxides with high specific surface area were prepared by the explosive decomposition of yttrium nitrate and its complex formed with methyl salicylate. The specific surface area and properties of powders synthesized at various temperatures were characterized using BET, X-ray diffraction (XRD), infrared spectra (IR), and scanning electron microscopy (SEM). The results indicate that the highest specific surface area is found to be 65.37 m2*g-1 at the calcination temperature of 600 ℃, and then decreases to 20.33 m2*g-1 with the calcination temperature rising from 600 to 900 ℃. The powders show strong surface activity for adsorping water and carbon dioxide in air, which also decreases with the rising calcination temperature. The drop both on the surface area and surface activity of samples at higher temperatures may be due to pore-narrowing(sintering) effects.

  10. Co-sputtering yttrium into hafnium oxide thin films to produce ferroelectric properties

    Science.gov (United States)

    Olsen, T.; Schröder, U.; Müller, S.; Krause, A.; Martin, D.; Singh, A.; Müller, J.; Geidel, M.; Mikolajick, T.

    2012-08-01

    Thin film capacitors were fabricated by sputtering TiN-Y doped HfO2-TiN stacks on silicon substrates. Yttrium was incorporated into the HfO2 layers by simultaneously sputtering from Y2O3 and HfO2 sources. Electric polarization and relative permittivity measurements yield distinct ferroelectric properties as a result of low yttrium dopant concentrations in the range of 0.9-1.9 mol. %. Grazing incidence x-ray diffraction measurements show the formation of an orthorhombic phase in this range. Compared to atomic layer deposition films, the highest remanent polarization and the highest relative permittivity were obtained at significantly lower doping concentrations in these sputtered films.

  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. 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....

  13. Effect of sintering on electrical properties of yttrium doped Li-based NASICON compounds

    Energy Technology Data Exchange (ETDEWEB)

    Kothari, Dharmesh H.; Kanchan, D. K., E-mail: dkkanchan.ssi@gmail.com; Dave, Gargi [Solid State Ionics & Glass Research Laboratory, Department of Physics, Faculty of Science, The M. S. University of Baroda, Vadodara, Gujarat-390002 (India)

    2015-08-28

    Electrical properties of Lithium based Li{sub 1.3}Al{sub 0.3-x}Y{sub x}Ti{sub 1.7}(PO{sub 4}){sub 3} (LAYTP) system was prepared using solid state reaction route. The samples were subjected to differing duration of sintering. X-ray diffraction was used to investigate the microstructure while density measurement was performed to determine the effect of sintering on the density of the prepared samples. Electrical properties of the material were studied using impedance spectroscopy, in frequency range 20 MHz to 1 Hz and in temperature range 303 K to 423 K. It was found that sample with least amount of yttrium and which was sintered for least duration had superior conductivity over other samples. It was also found that grain boundary conductivity improved marginally for sample with higher proportion of yttrium heat treated for longer duration.

  14. Demonstrating the potential of yttrium-doped barium zirconate electrolyte for high-performance fuel cells

    Science.gov (United States)

    Bae, Kiho; Jang, Dong Young; Choi, Hyung Jong; Kim, Donghwan; Hong, Jongsup; Kim, Byung-Kook; Lee, Jong-Ho; Son, Ji-Won; Shim, Joon Hyung

    2017-02-01

    In reducing the high operating temperatures (>=800 °C) of solid-oxide fuel cells, use of protonic ceramics as an alternative electrolyte material is attractive due to their high conductivity and low activation energy in a low-temperature regime (fuel cells. However, poor sinterability of yttrium-doped barium zirconate discourages its fabrication as a thin-film electrolyte and integration on porous anode supports, both of which are essential to achieve high performance. Here we fabricate a protonic-ceramic fuel cell using a thin-film-deposited yttrium-doped barium zirconate electrolyte with no impeding grain boundaries owing to the columnar structure tightly integrated with nanogranular cathode and nanoporous anode supports, which to the best of our knowledge exhibits a record high-power output of up to an order of magnitude higher than those of other reported barium zirconate-based fuel cells.

  15. Electrical resistivity of yttrium single crystals in the range 4. 2--300 K

    Energy Technology Data Exchange (ETDEWEB)

    Volkenshtein, N.V.; Dyakina, V.P.; Kumin, P.R.; Startsev, V.E.; Volkov, V.T.; Nikiforova, T.V.

    1984-08-01

    The electrical resistivity of pure yttrium single crystals (rho/sub 273.2//rho/sub 4.2/approx. =700) oriented along the <0001> and <1010> axes has been investigated in the temperature range 4.2--300 K. It was established that the scattering of electrons by phonons is described by the Bloch--Grueneisen function for both orientations over the whole temperature range, with the parameter THETA/sub R/ equal to the Debye temperature THETA/sub D/. It was found that a contribution to rho(T) quadratic in the temperature is two orders of magnitude greater than in other transition metals. It is shown that the anisotropy in the electrical resistivity of yttrium at Tapprox.THETA/sub D/ is completely determined by the anisotropy of its Fermi surface.

  16. 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.

  17. First principles DFT investigation of yttrium-doped graphene: Electronic structure and hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Desnavi, Sameerah, E-mail: sameerah-desnavi@zhcet.ac.in [Department of Electronic Engineering, ZHCET, Aligarh Muslim University, Aligarh-202002 (India); Chakraborty, Brahmananda; Ramaniah, Lavanya M. [High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)

    2014-04-24

    The electronic structure and hydrogen storage capability of Yttrium-doped grapheme has been theoretically investigated using first principles density functional theory (DFT). Yttrium atom prefers the hollow site of the hexagonal ring with a binding energy of 1.40 eV. Doping by Y makes the system metallic and magnetic with a magnetic moment of 2.11 μ{sub B}. Y decorated graphene can adsorb up to four hydrogen molecules with an average binding energy of 0.415 eV. All the hydrogen atoms are physisorbed with an average desorption temperature of 530.44 K. The Y atoms can be placed only in alternate hexagons, which imply a wt% of 6.17, close to the DoE criterion for hydrogen storage materials. Thus, this system is potential hydrogen storage medium with 100% recycling capability.

  18. Effect of Yttrium on Microstructure and Properties of High Temperature Alloys

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The effect of yttrium on the microstructure and properties of Ti-5.5Al-3.5Sn-3.0Zr-1Nb-0.3Mo-0.3Si (IMI 829) and Ti-14Al-21Nb high temperature alloys was studied by using optical microscope, SEM and mechanical property testing devices. The results show that the microstructure and grains of the two alloys can be fined by adding yttrium. For IMI829-0.2Y alloy, the favorable mechanical properties at room temperature and creep properties at 550℃ are obtained, and the high temperature mechanical properties of Ti-14Al-21Nb-0.1Y alloy are improved as well.

  19. Nano metric particles of yttrium ferrite; Particulas nanometricas de ferritas de itrio

    Energy Technology Data Exchange (ETDEWEB)

    Godoi, Ricardo H.M.; Jafelicci Junior, Miguel; Marques, Rodrigo F.C.; Varanda, Laudemir C. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Fisico-Quimica; Lima, Roberto C. [Instituto de Pesquisas da Marinha, Rio de Janeiro, RJ (Brazil)

    1999-12-01

    Nanoparticles of yttrium iron garnet (YIG) were obtained by coprecipitation. The particles were prepared by hydrolysis in acid medium with addition of ammonia or urea, for homogeneous nucleation, at 90 deg C. Different compositions and spherical morphologies were achieved by changing reactants concentrations and precipitation agent. X-ray diffractometry, transmission electron microscopy, differential thermal analysis and electrophoretic mobility were carried out on these particles to investigate the obtained phase, phase transition temperature, morphology, particle size and zeta potential, respectively. (author)

  20. Engineering of the band gap and optical properties of thin films of yttrium hydride

    Energy Technology Data Exchange (ETDEWEB)

    You, Chang Chuan; Mongstad, Trygve; Maehlen, Jan Petter; Karazhanov, Smagul, E-mail: smagulk@ife.no [Institute for Energy Technology, P.O. Box 40, NO-2027 Kjeller (Norway)

    2014-07-21

    Thin films of oxygen-containing yttrium hydride show photochromic effect at room temperature. In this work, we have studied structural and optical properties of the films deposited at different deposition pressures, discovering the possibility of engineering the optical band gap by variation of the oxygen content. In sum, the transparency of the films and the wavelength range of photons triggering the photochromic effect can be controlled by variation of the deposition pressure.

  1. Observation of spin rectification in Pt/yttrium iron garnet bilayer

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Jinwei; Fan, Xiaolong, E-mail: fanxiaolong@lzu.edu.cn; Zhou, Hengan; Zhao, Xiaobing; Zhao, Jing; Zhang, Fengzhen; Xue, Desheng [The Key Lab for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Ma, Li; Zhou, Shiming [Shanghai Key Laboratory of Special Artificial Microstructure and Technology and Pohl Institute of Solid State Physics and School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China)

    2015-05-07

    We used the ferromagnetic resonance (FMR) to study the dc voltage generation in Pt 20 nm layer deposited on yttrium iron garnet. Although the main contribution to the FMR voltage comes from the inverse spin Hall effect associated with spin pumping, the spin rectification would also contribute the resonance signal via the “new” magnetoresistance effect in Pt layer. Based on a symmetry consideration, we can separate those two effects through angular dependent resonance amplitude.

  2. 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.

  3. 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.

  4. High-spin europium and gadolinium centers in yttrium-aluminum garnet

    Science.gov (United States)

    Vazhenin, V. A.; Potapov, A. P.; Asatryan, G. R.; Uspenskaya, Yu. A.; Petrosyan, A. G.; Fokin, A. V.

    2016-08-01

    Electron-spin resonance spectra of Eu2+ and Gd3+ centers substituting Y3+ ions in single-crystal yttrium-aluminum garnet have been studied and the parameters of their rhombic spin Hamiltonian have been determined. The fine-structure parameters of the above ions have been calculated in the superposition model disregarding changes in the angular coordinates of the ligand environment of the impurity defect thus demonstrating the necessity of taking these changes into account.

  5. Fabrication, characterization, and fluorine-plasma exposure behavior of dense yttrium oxyfluoride ceramics

    Science.gov (United States)

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

    2017-06-01

    Yttrium oxyfluoride (YOF) ceramics are expected to be one of the attractive plasma-resistant materials for semiconductor production equipment. In this study, dense YOF ceramics were fabricated by hot pressing using YOF powder, and their physical, mechanical, and thermal properties were characterized. Moreover, behavior against fluorine-plasma exposure was investigated. The results suggest that the YOF ceramics showed excellent mechanical and thermal properties, and superior resistance for fluorine-plasma exposure to Y2O3 ceramics.

  6. Extraction of Yttrium (Ⅲ) into [C8mim][PF6] Containing Cyanex 923

    Institute of Scientific and Technical Information of China (English)

    Peng Bo; Sun Xiaoqi; Chen Ji; Ma Jiutong

    2007-01-01

    The extraction of Yttrium (Ⅲ) into [Cnmim] [PF6] (n=4,6,8) containing Cyanex 923 was studied in this paper. The mechanism of this extraction was indicated to be cation exchange. In addition, the extraction process is an endothermic reaction. The RTILs with shorter alkyl chain behave higher extraction efficiency during the extraction, however, which has also more loss to aqueous phase since the cation exchange mechanism.

  7. Yttrium-90 Radioembolization of Hepatocellular Carcinoma-Performance, Technical Advances, and Future Concepts.

    Science.gov (United States)

    Molvar, Christopher; Lewandowski, Robert

    2015-12-01

    Hepatocellular carcinoma (HCC) is a lethal tumor, claiming over half a million lives per year. Treatment of HCC is commonly performed without curative intent, and palliative options dominate, including catheter-based therapies, namely, transarterial chemoembolization and yttrium-90 ((90)Y) radioembolization. This review will showcase the performance of (90)Y radioembolization for the treatment of HCC, focusing on recent seminal data and technical advances. In particular, novel radioembolization treatment concepts are discussed and compared with conventional HCC therapy.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mozaffari, M., E-mail: mozafari@sci.ui.ac.ir; Amighian, J.; Tavakoli, R.

    2015-04-01

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

  9. 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.

  10. 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.

  11. Demonstrating the potential of yttrium-doped barium zirconate electrolyte for high-performance fuel cells.

    Science.gov (United States)

    Bae, Kiho; Jang, Dong Young; Choi, Hyung Jong; Kim, Donghwan; Hong, Jongsup; Kim, Byung-Kook; Lee, Jong-Ho; Son, Ji-Won; Shim, Joon Hyung

    2017-02-23

    In reducing the high operating temperatures (≥800 °C) of solid-oxide fuel cells, use of protonic ceramics as an alternative electrolyte material is attractive due to their high conductivity and low activation energy in a low-temperature regime (≤600 °C). Among many protonic ceramics, yttrium-doped barium zirconate has attracted attention due to its excellent chemical stability, which is the main issue in protonic-ceramic fuel cells. However, poor sinterability of yttrium-doped barium zirconate discourages its fabrication as a thin-film electrolyte and integration on porous anode supports, both of which are essential to achieve high performance. Here we fabricate a protonic-ceramic fuel cell using a thin-film-deposited yttrium-doped barium zirconate electrolyte with no impeding grain boundaries owing to the columnar structure tightly integrated with nanogranular cathode and nanoporous anode supports, which to the best of our knowledge exhibits a record high-power output of up to an order of magnitude higher than those of other reported barium zirconate-based fuel cells.

  12. Synthesis and characterization of branched yttrium hydroxide fluoride microcrystals with hierarchical tubular structure

    Institute of Scientific and Technical Information of China (English)

    TIAN Li; JIANG Wentao; SUN Qiliang; LIU Jin

    2012-01-01

    Hexagonal yttrium hydroxide fluoride microcrystals were prepared by a two-step hydrothermal route using yttrium nitrate,sodium hydroxide and sodium fluoride as raw materials to react in propanetriol solvent.The samples were characterized by powder X-ray diffraction (XRD),energy dispersive spectrum (EDS),scanning electron microscopy (SEM),transmission electron microscopy (TEM),Fourier transform infrared spectroscopy (FT-IR),thermogravimetre and differential-thermogravimetric analysis (TG-DTA),which revealed that Y(OH)2.14F0.86 microcrystals were multi-branched and that the branches of Y(OH)2.14F0.86 microcrystals were composed of hierarchical tubes.This novel multi-branched and intriguing hierarchical tubular structure of yttrium hydroxide fluoride maybe has a potential application in photoelectric crystals.The formation of branched Y(OH)2.14F0.86 microcrystals with hierarchical tubular structure were due to the substitution reaction and Oswald ripening.

  13. Effect of yttrium on the mechanical and magnetostrictive properties of Fe83Ga17 alloy

    Institute of Scientific and Technical Information of China (English)

    李纪恒; 肖锡铭; 袁超; 高学绪; 包小倩

    2015-01-01

    Polycrystalline rod samples of (Fe83Ga17)100–xYx(x=0, 0.16, 0.32, 0.48, 0.64) were prepared by induction melting under ar-gon atmosphere. Effect of yttrium on the mechanical and magnetostrictive properties of Fe83Ga17 alloy was investigated. Small amount of yttrium (0.16 at.%) increased the tensile strength of as-cast Fe83Ga17 alloys to 674 MPa and improved the ductility with elongation of 4.2% at room temperature. The Y2Fe17?xGax (6≤x≤7) phase was formed in the Y-doped Fe83Ga17 alloy since yttrium was hardly dissolved into theα-Fe lattice. Y2(FeGa)17 secondary phase dispersed along the grain boundaries and inside the grains played an important role for the enhancement of mechanical property. The 0.64 at.% Y-doped alloy had magnetostriction of 133 ppm, which was thought to be associated with the alteration of the grain shape and preferential orientation along the axial direction of rods.

  14. Crystal structure and switchable optical properties of yttrium hydride films covered by palladium layer

    Institute of Scientific and Technical Information of China (English)

    张文魁; 甘永平; 杨晓光; 黄辉; 余厉阳

    2003-01-01

    The palladium/yttrium films were prepared using magnetron sputtering technique.The changes of crystal structure,morphology and optical properties of the films during the hydrogen absorption/desorption process were investigated.The results of SEM and AFM analysis show that yttrium films have columnar structure,and the Pd cover layers on the surface of the yttrium films are composed of nanometer-sized Pd particles,which contain a large amount of smaller crystalline grains.During the gas hydrogen absorption/desorption process,YH3 and YH2 hydrides form on the sites of Pd grains contacting with Y grains.Upon hydrogenation,YH3 hydride forms and the switchable optical properties can be observed.The light transparency of the films increases with the increasing of hydrogen loading time and the light wavelength,and the absorption limitation occurs at λ=400 nm.Upon dehydrogenation,YH3 hydride dissociates into YH2 hydride,and the maximum transparency occurs at λ=689 nm.

  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. 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.

  17. Yttrium doped TiO2 porous film photoanode for dye-sensitized solar cells with enhanced photovoltaic performance

    Science.gov (United States)

    Qu, Xiaofei; Hou, Yuchen; Liu, Meihua; Shi, Liang; Zhang, Mingqian; Song, Hongbing; Du, Fanglin

    In this paper, TiO2 photoanodes were doped with yttrium under different doping concentrations via hydrothermal method and further employed to assemble dye-sensitized solar cells (DSSCs). XRD, XPS, SEM, TEM, UV-Vis DRS and PL measurements were carried out to investigate the yttrium doping effects on crystal structure, chemical status, optical properties and dye loading capacity of the photoanodes. The photovoltaic performance of the photoanodes with various yttrium doping concentration was measured by recording the photocurrent-photovoltaic curves, and the result indicated that TiO2:0.006 Y exhibited the best power conversion efficiency with high short circuit current density (Jsc) and open circuit voltage (Voc). This improvement may be due to the enhanced visible light harvesting, increased dye loading capacity and reduced photoelectron recombination.

  18. Corrosion Behavior of Mg-6Al-1Zn+XRE Magnesium Alloy with Minor Addition of Yttrium

    Science.gov (United States)

    Manivannan, S.; Babu, S. P. Kumaresh; Sundarrajan, Srinivasan

    2015-04-01

    The effect of yttrium addition on the microstructure of Mg-6Al-1Zn alloy was investigated by optical microscopy, x-ray diffraction analysis, and scanning electron microscopy. The experimental alloys were prepared by melting high-purity Mg, Al, Zn, and Y, respectively. Melting was carried out in a Inconel 718 crucible under SF6 and ultra pure Ar (99.999%) gas mixture environment using electric arc furnace. The corrosion behavior of Mg-6Al-1Zn+ xYttrium ( x = 0.5, 1.0 and 1.5 wt.% Y) magnesium alloy with different levels of yttrium additions was studied in 3.5 wt.% NaCl solution. Microstructure of yttrium-added alloy shows that higher grainrefinement is obtained in Mg-6Al-1Zn+0.5wt.%Y. Increasing yttrium content reduces the size of α-grain and alters the distribution of the β-phase (Mg17Al12) from continuous network morphology to small and dispersive distribution. It forms secondary intermetallic phase Al2Y which has high melting point along the grain boundary. The corrosion resistance of Mg-6Al-1Zn magnesium alloy improved with addition of Yttrium. It was confirmed by the results of electrochemical polarization test. Based on the polarization curves, it is seen that fine precipitates of Al-Y intermetallic phase in Mg-6Al-1Zn alloy decrease the corrosion current density, thereby improving the corrosion resistance of the Mg-6Al-1Zn magnesium alloy.

  19. 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

  20. Superconductivity in fluorine and yttrium co-doped SmFeAsO

    Science.gov (United States)

    Lai, K. T.; Kwong, F. L.; Ng, Dickon H. L.

    2012-05-01

    Polycrystalline fluorine and yttrium co-doped SmFeAsO samples are synthesized by solid state sintering and their physical properties are studied. The lattice parameters of the Sm1-yYyFeAsO0.8F0.2 samples decrease with the increasing y due to the smaller Y ions and the stiffness of the Y-O bond. The maximum critical temperature Tc of the samples is at y = 0.05. This may be due to the fact that the strong interaction between Sm and Fe of the Fe-As bond is being re-disturbed by the doped Y ions.

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

    Science.gov (United States)

    Chaptini, Cassandra; Huilgol, Shyamala C

    2015-08-01

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

  2. The Effect of Chelating Copolymer Additive on the Yttrium Iron Garnet Nanoparticle Formation

    Institute of Scientific and Technical Information of China (English)

    Wang; Cheng-chien

    2007-01-01

    1 Results Yttrium iron garnet (YIG) is a well-known ferromagnetic garnet material and has widely used in electronic devices[1].A new acrylic chelating polymer was developed to act as the additive of the preparation of YIG precursor in our previous study[2].The sintering temperature of YIG nanocrystal obtained by this YIG precursor (ACP) was magnificently descended from 1 000 to 600 ℃.In this study,we were further to study the effect of amount of chelating polymer and the compositions of chelating polyme...

  3. Synthesis and Characterization of Large Surface Area Yttrium Oxide by Precipitation Method

    Institute of Scientific and Technical Information of China (English)

    崔大立; 龙志奇; 张顺利; 崔梅生; 黄小卫

    2004-01-01

    The method for preparing yttrium oxide with large specific surface area was introduced. By means of BET, SEM, TG and DTA analysis, the effects of precipitant, stirring velocity, non-RE impurity in solution, calcination temperature, on the surface area were studied respectively. The Y2O3 sample with specific surface area of more than 60 m2*g-1 and L.O.I less than 1% was prepared in the suitable precipitation condition and calcinations temperature when the ammonia used as precipitant. The SEM shows that the Y2O3 prepared with large surface area is the aggregation of about 50 nm particles.

  4. A nonreciprocal racetrack resonator based on vacuum-annealed magnetooptical cerium-substituted yttrium iron garnet.

    Science.gov (United States)

    Goto, Taichi; Onbasli, Mehmet C; Kim, Dong Hun; Singh, Vivek; Inoue, M; Kimerling, Lionel C; Ross, C A

    2014-08-11

    Vacuum annealed polycrystalline cerium substituted yttrium iron garnet (CeYIG) films deposited by radio frequency magnetron sputtering on non-garnet substrates were used in nonreciprocal racetrack resonators. CeYIG annealed at 800°C for 30 min provided a large Faraday rotation angle, close to the single crystal value. Crystallinity, magnetic properties, refractive indices and absorption coefficients were measured. The resonant transmission peak of the racetrack resonator covered with CeYIG was non-reciprocally shifted by applying an in-plane magnetic field.

  5. 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

  6. 钇的光度分析进展%Advancement of Spectrophotometric Analysis for Determining Yttrium

    Institute of Scientific and Technical Information of China (English)

    杨乡珍

    2001-01-01

    The advancement of spectrophotometry for determining yttrium has been reviewed.There are conventional spectrophotometry ,chemiluminescence method,flow-injection kinetic photometry and fluorophotometry.52 references are quoted.%对钇的光度分析方法,包括常规光度法、化学发光法、流动注射动力学法和荧光光度法等近些年的进展进行了综述。参考文献52篇。

  7. 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.

  8. 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.

  9. 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.

  10. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-17

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

  12. 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.

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    Ranganaik Viswanath

    2014-01-01

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

  15. Migration mechanism for oversized solutes in cubic lattices: The case of yttrium in iron

    Science.gov (United States)

    Bocquet, Jean-Louis; Barouh, Caroline; Fu, Chu-Chun

    2017-06-01

    Substitutional solutes in metals generally diffuse by successive exchanges with vacancies, that is, via the so called vacancy mechanism. However, recent density functional theory (DFT) calculations predicted an atypical behavior for the oversized solute atoms (OSAs) in bcc and fcc iron. These solutes exhibit a very strong attraction with a nearby vacancy (V) at a first neighbor (1nn) distance. The attraction is so large that the 1nn OSA-V pair is no longer stable and relaxes spontaneously towards a new configuration where the OSA sits in the middle of the two half-vacancies (V/2). As a consequence, the diffusion of OSAs cannot be described by the standard vacancy mechanism. A new migration mechanism with a new formulation of correlation effects is required. The present study rests on a revised expression of the diffusion coefficient of the OSAs in bcc and fcc lattices, which introduces the concept of macrojumps. The formalism is applied presently to the case of yttrium (Y: a principal alloying element of advanced steels) in iron, using DFT data. But it is directly transferable to other OSAs in cubic metal lattices. At variance with the standard substitutional solutes, the Y atom is found to diffuse more rapidly than iron at all temperatures by orders of magnitude in the two cubic-Fe structures. This finding is opposite to the recent common belief that yttrium is a slow diffusing species in Fe alloys, based on experimental evidences. Several suggestions are proposed to solve this apparent inconsistency.

  16. The oxide phase formation modelling at the deoxidization process in yttrium steels

    Directory of Open Access Journals (Sweden)

    Петро Степанович Харлашин

    2016-11-01

    Full Text Available In recent years approaches to high-quality steel production have significantly changed. The influence of the oxide and sulfide non-metallic inclusions should be noted in particular. Modifying is followed with the change in the inclusions chemical composition, they are generally being MnS inclusions and fragile oxidic inclusions. Modification results in the formation of spherical oxides and yttrium sulfides that don’t deform at rolling. Nowadays modifying with rare-earth elements has no broad application because of the use of cheaper lime which possesses similar efficiency. That is why REM are applied generally as microparticles, and their deoxidating and desulphurizing abilities are limited because of their high cost in comparison with the expenditures on modern extra oven processing of steel. Nonmetallic inclusions hardly influence on «volume» processes of plastic deformation and hardening. The use of rare-earth metals and their combinations as nonmetallic inclusions modifiers appear to have considerable promise. Therefore the modelling and further calculation of oxygen and sulfur interaction with yttrium in metal were carried out

  17. Precision Wavelength Measurements And Identifications Of EUV Lines From Highly Charged L-Shell yttrium Ions

    Science.gov (United States)

    Silwal, Roshani; Dreiling, Joan; Gillaspy, John; Takacs, Endre; Ralchenko, Yuri

    2016-05-01

    We present the measurements of extreme-ultraviolet spectra of the L-shell ions of highly charged yttrium (Y29+- Y36+) created and trapped in the electron beam ion trap (EBIT) of the National Institute of Standards and Technology. Few Na-like, Mg-like and Al-like yttrium lines (Y26+- Y28+) are reported as well. In order to reach the desired ionization stages, the beam energy was systematically varied from 2.3 keV to 6 keV during the experiment. A flat-field grazing-incidence spectrometer was used to record the spectra in the wavelength range of 4.022 nm to 19.957 nm. The wavelength calibration was provided by the previously measured lines of neon, xenon, oxygen and iron. A total of 63 new spectral lines (allowed and forbidden) corresponding to the Δn = 0 transitions within n = 2 and 3 have been identified using collisional-radiative simulations of the non-Maxwellian EBIT plasma. The total uncertainties assigned to the measured wavelengths vary between 0.001 nm to 0.003 nm and include contributions from calibration uncertainties, statistical uncertainties from the line fits, and estimated systematic uncertainties.

  18. Microstructure, microhardness, and biocompatibility characteristics of yttrium hydroxyapatite doped with fluoride.

    Science.gov (United States)

    Toker, S M; Tezcaner, A; Evis, Z

    2011-02-01

    The current study focused on doping of hydroxyapatite (HA) with constant yttrium (Y(3+) ) and varying fluoride (F(-) ) compositions to investigate its microstructure, microhardness, and biocompatibility. HA was synthesized by precipitation method and sintered at 1100°C for 1 h. Y(3+) and F(-) ion dopings resulted in changes in densities. In x-ray diffraction analysis, no secondary phase formation was observed. Lattice parameters decreased upon ion substitutions. Scanning electron microscopy (SEM) results showed that ion addition resulted in smaller grains. In Fourier transform infrared spectroscopy analysis, F(-) ion substitution was confirmed. HA doped with 2.5% Y(3+) and 1% F(-) exhibited the highest microhardness. Y(3+) and F(-) ions improved Saos-2 cell proliferation on discs in Methylthiazolyldiphenyl-tetrazolium (MTT) assay. In SEM analysis, cells attached and proliferated on all disc surfaces. Alkaline phosphatase (ALP) assay showed that cell differentiation on the discs was improved by doping HA with an optimum F(-) amount. Dissolution tests revealed that structural stability of HA was improved with F(-) ion incorporation. The dissolution behavior of fluoridated samples exhibited a parallel pattern with the cell proliferation and differentiation behavior on these samples. Overall, this work shows that fluoride and yttrium cosubstitution into HA HA2.5Y1F was the most promising material for biomedical applications. Copyright © 2010 Wiley Periodicals, Inc.

  19. Eggshell- and fur-like microstructures of yttrium silicate film prepared by laser chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Akihiko, E-mail: itonium@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Miyagi (Japan); Endo, Jun; Kimura, Teiichi; Goto, Takashi [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Miyagi (Japan)

    2011-01-01

    Yttrium silicate (Y-Si-O) films with eggshell- and fur-like microstructures were prepared by laser chemical vapor deposition using a Nd:YAG laser, and tetraethyl orthosilicate (TEOS) and yttrium dipivaloylmethane (Y(dpm){sub 3}) precursors. Amorphous Y-Si-O films were prepared at deposition temperature below 1200 K. The crystalline Y-Si-O films with mixtures of Y{sub 4.67}(SiO{sub 4}){sub 3}O and {alpha}-Y{sub 2}Si{sub 2}O{sub 7} phases were obtained at deposition temperature above 1200 K. y-Y{sub 2}Si{sub 2}O{sub 7} and X1-Y{sub 2}SiO{sub 5} minor phases were also formed at a higher deposition temperature. At deposition temperature ranging between 1285 and 1355 K, a dome-like structure covered with fine fur-like projections was formed under a total pressure of 3.5 kPa, whereas an eggshell-like structure 200-300 {mu}m in diameter and 10-20 {mu}m in shell thickness was formed at 7.5 kPa. The deposition rate for the Y-Si-O films with fur- and eggshell-like microstructures reached 300 and 1000 {mu}m h{sup -1}, respectively.

  20. Intervalence Charge Transfer luminescence: The anomalous luminescence of Cerium-doped Cs2LiLuCl6 elpasolite

    CERN Document Server

    Seijo, Luis

    2014-01-01

    The existence of intervalence charge transfer (IVCT) luminescence is reported. It is shown that the so called anomalous luminescence of Ce-doped elpasolite Cs2LiLuCl6, which is characterized mainly by a very large Stokes shift and a very large band width, corresponds to an IVCT emission in Ce3+-Ce4+ pairs, from the 5deg orbital of Ce3+ to 4f orbitals of Ce4+. Its Stokes shift is the sum of the large reorganization energies of the Ce4+ and Ce3+ centers formed after the fixed-nuclei electron transfer and it is equal to the energy of the IVCT absorption commonly found in mixed-valence compounds, which is predicted to exist in this material and to be slightly larger than 10000 cm-1. The large band width is the consequence of the large offset between the minima of the Ce3+-Ce4+ and Ce4+-Ce3+ pairs along the electron transfer reaction coordinate. This offset is approximately 2*sqrt(3) times the difference of Ce-Cl equilibrium distances in the Ce3+ and Ce4+ centers. It is shown that the energies of the peaks and the...

  1. Photoluminescence on cerium-doped ZnO nanorods produced under sequential atomic layer deposition-hydrothermal processes

    Science.gov (United States)

    Cervantes-López, J. L.; Rangel, R.; Espino, J.; Martínez, E.; García-Gutiérrez, R.; Bartolo-Pérez, P.; Alvarado-Gil, J. J.; Contreras, O. E.

    2017-01-01

    Doped and undoped ZnO nanorod arrays were produced combining atomic layer deposition and hydrothermal processes. First, a ZnO layer with preferential orientation normal to the c-axis was grown on the substrate by means of the decomposition of diethylzinc; subsequently, the nanorod arrays were produced through solvothermal process using a solution of Zn(NO3)2 as precursor. Doped ZnO nanorods were produced using Ce(C2H3O2)3·H2O as dopant agent precursor. Undoped and Ce-doped ZnO nanorod arrays showed high-intensity photoluminescence. The doping concentration of x = 0.04 (Zn1- x Ce x O) displayed the highest photoluminescence. Undoped ZnO showed an intense UV peak centered at 382 nm with a narrow full wide half maximum of 33 nm. Ce-doped ZnO PL spectra contain three bands, one signal in the UV region centered at 382 nm, other centered at 467 nm in the near-green region and other one emission centered at 560 nm. The results herein exposed demonstrate the capability to produce high-quality ZnO and Zn1- x Ce x O films.

  2. Fabrication characterization and activity of a solar light driven photocatalyst: cerium doped TiO2 magnetic nanofibers.

    Science.gov (United States)

    Li, Cong-Ju; Wang, Bin; Wang, Jiao-Na

    2012-03-01

    A novel magnetic separable composite photocatalytic nanofiber consisting of TiO2 as the major phase, CeO(2-y) and CoFe2O4 as the dopant phase was prepared by sol-gel method and electrospinning technique, and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectrum (UV-vis DRS) and vibrating sample magnetometer (VSM). The photocatalytic activity of the resultant CoFe2O4-TiO2 and CeO(2-y)/CoFe2O4-TiO2 nanofibers was evaluated by photodegradation of methylene blue (MB) in an aqueous solution under xenon lamp (the irradiation spectrum energy distribution is similar to sunlight) irradiation in a photochemical reactor. The results showed that the dopant of Ce could affect the absorbance ability and photo-response range. The sample containing 1.0 wt% CeO(2-y) exhibited the highest degradation with 35% for MB under simulate solar light irradiation. Furthermore, the as-synthesized composite photocatalytic nanofibers could be separated easily by an external magnetic field, thus it might hold potential for application in wastewater treatment.

  3. Study on cerium-doped nano-TiO2 coatings for corrosion protection of 316 L stainless steel

    Science.gov (United States)

    Li, Suning; Wang, Qian; Chen, Tao; Zhou, Zhihua; Wang, Ying; Fu, Jiajun

    2012-04-01

    Many methods have been reported on improving the photogenerated cathodic protection of nano-TiO2 coatings for metals. In this work, nano-TiO2 coatings doped with cerium nitrate have been developed by sol-gel method for corrosion protection of 316 L stainless steel. Surface morphology, structure, and properties of the prepared coatings were investigated by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. The corrosion protection performance of the prepared coatings was evaluated in 3 wt% NaCl solution by using electrochemical techniques in the presence and absence of simulated sunlight illumination. The results indicated that the 1.2% Ce-TiO2 coating with three layers exhibited an excellent photogenerated cathodic protection under illumination attributed to the higher separation efficiency of electron-hole pairs and higher photoelectric conversion efficiency. The results also showed that after doping with an appropriate concentration of cerium nitrate, the anti-corrosion performance of the TiO2 coating was improved even without irradiation due to the self-healing property of cerium ions.

  4. Visible light activated photocatalytic degradation of tetracycline by a magnetically separable composite photocatalyst: Graphene oxide/magnetite/cerium-doped titania.

    Science.gov (United States)

    Cao, Muhan; Wang, Peifang; Ao, Yanhui; Wang, Chao; Hou, Jun; Qian, Jin

    2016-04-01

    In this study, magnetic graphene oxide-loaded Ce-doped titania (MGO-Ce-TiO2) hybridized composite was prepared by a facile method. The as-prepared samples exhibited good adsorption capacity, high visible-light photoactive and magnetic separability as a novel photocatalyst in the degradation of tetracyclines (TC). The intermediate products and photocatalytic route of TC were proposed based on the analysis results of LC-MS. Moreover, the repeatability of the photoactivity with the use of MGO-Ce-TiO2 was investigated in the multi-round experiments with the assistance of an applied magnetic field. Therefore, the prepared composite photocatalysts were considered as a kind of promising photocatalyst in a suspension reaction system, in which they can offer effectively recovery ability. The effect of MGO content on the photocatalytic performance was also studied, and an optimum content was obtained. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. The effects of cerium doping concentration on the properties and photocatalytic activity of bimetallic Mo/Ce catalyst

    Science.gov (United States)

    Allaedini, Ghazaleh; Tasirin, Siti Masrinda; Aminayi, Payam

    2016-10-01

    In this study, the characterization and photocatalytic activity of MoO3 nanoparticles doped with various doping concentrations of cerium have been investigated. The Fourier transform infrared (FT-IR) spectra of the prepared catalysts confirmed that MoO3 particles have been successfully doped by cerium. Field emission scanning electron microscopy (FESEM) was performed to visualize the surface morphology of the obtained catalysts. The XRD patterns suggested that the crystallinity of the sample with the lowest doping concentration of 15 mol % was higher in comparison with samples of higher doping concentrations. The volume-averaged crystal sizes of the obtained catalysts were calculated to be 25, 28, and 32 nm for 15, 35, and 60 mol % samples, respectively. The photocatalytic activity along with the reaction kinetics of Ce-doped MoO3 nanoparticles have also been investigated through the dye degradation of methyl orange. The synthesized Ce-doped MoO3 particles with the lowest dopant concentration of 15 mol % exhibited the highest photocatalytic activity for methyl orange dye degradation. It was observed that photo-degradation activity decreased with an increase in the doping concentration of cerium. The predicted rate constants for samples with 15, 35, and 60 mol % doping concentrations were found to be 0.0432, 0.035, and 0.029 min-1, respectively.

  6. Magnetic evolution of itinerant ferromagnetism and interlayer antiferromagnetism in cerium doped LaCo2P2 crystals

    Science.gov (United States)

    Tian, Yong; Kong, Yixiu; Liu, Kai; Zhang, Anmin; He, Rui; Zhang, Qingming

    2017-05-01

    ThCr2Si2-type phosphide ACo2P2 (A=Eu, La, Pr, Nd, Ce) has the same structure as iron arsenides, but their magnetic behaviors are quite distinct. In this paper, we grew a series of La1-xCexCo2P2 single crystals (x=0.0 to1.0), made structural and magnetic characterizations. We found the introduction of cerium induces a rapid decrease of c-axis and a change from ferromagnetic to antiferromagnetic states. Compared to other trivalent doped compounds, the enhancement of ferromagnetism with doping is suppressed and the transition from ferromagnetism to antiferromagnetism appear earlier. By employing first-principles band-structure calculations, we identify the increase of Ce valence suppress the itinerant ferromagnetism and leading to formation of P-P bonding with the shortening of c-axis. The bonding effectively drives an increase of interlayer antiferromagnetic interaction, eventually leads to antiferromagnetic ordering of cobalt in high-doping region.

  7. Effect of cerium doping on the structural, morphological, photoluminescent and thermoluminescent properties of sodium strontium pentaborate microstructures

    Energy Technology Data Exchange (ETDEWEB)

    Joo, S.W.; Dillip, G.R.; Banerjee, A.N. [Yeungnam University, School of Mechanical Engineering and Technology, Gyeongsan (Korea, Republic of); Raju, B.D.P. [Sri Venkateswara University, Department of Future Studies, Tirupati (India); Jung, J.H. [Yeungnam University, School of Chemical Engineering, Gyeongsan (Korea, Republic of)

    2016-02-15

    We have reported a new blue-emitting cerium (Ce{sup 3+})-doped sodium strontium pentaborate (Na{sub 3}SrB{sub 5}O{sub 10}) microstructures via a conventional high-temperature solid-state reaction route. X-ray diffraction analysis revealed the phosphors crystallized in triclinic structure. Significantly, well-shaped morphology in micrometer dimension phosphors was identified by field emission scanning electron microscopy. The phosphors displayed a single broad blue emission centered at around 370 nm because of the Ce{sup 3+} 5d-4f transition under the excitation wavelength of 232 nm. In the region of room temperature to 350 C, the thermoluminescence (TL) glow curves consist of only one sharp peak located at about 200.31 C. The optimum concentration of Ce{sup 3+} for TL and PL intensity was found to be 1 at.% in host. These results suggest that the newly proposed Na{sub 3}SrB{sub 5}O{sub 10}:Ce{sup 3+} phosphor with the suitable TL emission (T{sub m} ∝ 200 C) in micrometer dimension might potentially be used for thermoluminescence dosimetric applications. (orig.)

  8. Ferromagnetic resonance induced large microwave magnetodielectric effect in cerium doped Y3Fe5O12 ferrites

    Science.gov (United States)

    Chen, Fu; Wang, Xian; Nie, Yan; Li, Qifan; Ouyang, Jun; Feng, Zekun; Chen, Yajie; Harris, Vincent G.

    2016-06-01

    In recent years, multifunctional materials contained simultaneous ferroelectric and ferromagnetic ordering have been realized. Here, a real time room temperature adaptive materials system, which demonstrates an RF magnetodielectric (MD) response, i.e., CexY3-xFe5O12 (x = 0, 0.05, 0.1, 0.15, 0.2), is reported. The magnetic and dielectric properties of Ce-doped YIG microwave ferrites processed by a traditional ceramic route have been measured over a frequency range of 4-8 GHz (C-band). The substitution of Ce not only enhances the microwave electromagnetic properties of the YIG, but also modulates the magnetodielectric response. The maximum magnetodielectric response in Ce-doped YIG sample ranges in magnitude from approximately +5% to -5% under an applied field of 1.78 kOe. This effect was attributed to electron fluctuations on the Fe cation sites. Furthermore, the magnitude of the MD response was shown to be enhanced by the cerium content. It is believed that research of the magnetodielectric effect in YIG ferrites is of great importance to the development of next generation multifunctional adaptive microwave materials, devices and integrated circuits.

  9. Investigations on structural and photoluminescence mechanism of cerium doped L-Histidine hydrochloride mono hydrate single crystals for optical applications

    Science.gov (United States)

    Rajyalakshmi, S.; Ramachandra Rao, K.; Brahmaji, B.; Samatha, K.; Visweswara Rao, T. K.; Ramakrishna, Y.

    2017-02-01

    Semi organic nonlinear optical material of Ce3+ ion added L-Histidine hydrochloride monohydrate (LHHC) crystals have been grown successfully by the slow evaporation solution technique (SEST) as well as Sankaranarayanan-Ramasamy (SR) technique. Unit cell data have been measured from the single crystal X-ray diffraction analysis and High resolution X-ray diffraction analysis (HRXRD) study shows relatively a good crystalline perfection. Fourier transform infra-red spectroscopy (FTIR) spectra indicates that the Ce3+ ion is coordinated with carboxylate group of grown crystal. The lower UV-cutoff wavelength of the incorporation of Ce3+ ion in LHHC is 240 nm. The incorporation of Ce3+ ion in the crystal lattice was observed by energy dispersive X-ray analysis (EDAX). The nonlinear optical (NLO) efficiency of SR-grown crystal is 3.7 times greater with respect to potassium dihydrogen phosphate (KDP). We report first-time the photoluminescence (PL) mechanism of emission spectrum, which shows broad band located at 350 nm corresponding to 5d → 4f transition of Ce3+ ion and excited by 250 nm wavelength. The excitation spectrum shows a band at 258 nm due to the 4f → 5d transition of Ce3+ ion. The nature of decay curve of the grown crystal is bi-exponential with a long life time of τ2 is 8.8270 μs.

  10. Photoluminescence of cerium fluoride and cerium-doped lanthanum fluoride nanoparticles and investigation of energy transfer to photosensitizer molecules.

    Science.gov (United States)

    Cooper, Daniel R; Kudinov, Konstantin; Tyagi, Pooja; Hill, Colin K; Bradforth, Stephen E; Nadeau, Jay L

    2014-06-28

    CexLa1-xF3 nanoparticles have been proposed for use in nanoscintillator-photosensitizer systems, where excitation of nanoparticles by ionizing radiation would result in energy transfer to photosensitizer molecules, effectively combining the effects of radiotherapy and photodynamic therapy. Thus far, there have been few experimental investigations of such systems. This study reports novel synthesis methods for water-dispersible Ce0.1La0.9F3/LaF3 and CeF3/LaF3 core/shell nanoparticles and an investigation of energy transfer to photosensitizers. Unbound deuteroporphyrin IX 2,4-disulfonic acid was found to substantially quench the luminescence of large (>10 nm diameter) aminocaproic acid-stabilized nanoparticles at reasonable concentrations and loading amounts: up to 80% quenching at 6% w/w photosensitizer loading. Energy transfer was found to occur primarily through a cascade, with excitation of "regular" site Ce(3+) at 252 nm relayed to photosensitizer molecules at the nanoparticle surface through intermediate "perturbed" Ce(3+) sites. Smaller (<5 nm) citrate-stabilized nanoparticles were coated with the bisphosphonate alendronate, allowing covalent conjugation to chlorin e6 and resulting in static quenching of the nanoparticle luminescence: ∼50% at ∼0.44% w/w. These results provide insight into energy transfer mechanisms that may prove valuable for optimizing similar systems.

  11. A Solid State Ultraviolet Lasers Based on Cerium-Doped LiCaAIF(sub 6) Crystal Resonator

    Science.gov (United States)

    Yu, Nan; Le, Thanh; Schowalter, Steven J.; Rellergert, Wade; Jeet, Justin; Lin, Guoping; Hudson, Eric

    2012-01-01

    We report the first demonstration of a UV laser using a high-Q whispering gallery mode (WGM) resonator of Ce+: LiCaAlF6. We show that WGM resonators from LiCaAlF6 can achieve a Q of 2.6 x 10(sup 7) at UV. We demonstrated a UV laser at 290 nm with a pulsed pump laser at 266 nm. The experiments showed the low pump threshold intensity of 7.5 x 10(sup 9) W/m(sup 2) and slope efficiency of 25%. We have also observed lasing delay dynamics. These results are consistent with our modeling and theoretical estimates, and pave the way for a low threshold cw UV laser using WGM resonator cavity.

  12. A Solid State Ultraviolet Lasers Based on Cerium-Doped LiCaAIF(sub 6) Crystal Resonator

    Science.gov (United States)

    Yu, Nan; Le, Thanh; Schowalter, Steven J.; Rellergert, Wade; Jeet, Justin; Lin, Guoping; Hudson, Eric

    2012-01-01

    We report the first demonstration of a UV laser using a high-Q whispering gallery mode (WGM) resonator of Ce+: LiCaAlF6. We show that WGM resonators from LiCaAlF6 can achieve a Q of 2.6 x 10(sup 7) at UV. We demonstrated a UV laser at 290 nm with a pulsed pump laser at 266 nm. The experiments showed the low pump threshold intensity of 7.5 x 10(sup 9) W/m(sup 2) and slope efficiency of 25%. We have also observed lasing delay dynamics. These results are consistent with our modeling and theoretical estimates, and pave the way for a low threshold cw UV laser using WGM resonator cavity.

  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. Structure and morphological analysis of various composition of yttrium doped-zirconia prepared from local zircon sand

    Science.gov (United States)

    Rahmawati, F.; Permadani, I.; Heraldy, E.; Syarif, D. G.; Soepriyanto, S.

    2016-11-01

    Yttrium ions, Y3+ were doped into ZrO2 that was synthesized from zircon sand. Zircon sand is a side product of tin mining plant in Bangka Island, Indonesia. Solid state reaction was chosen as the method to dope yttrium ions from Y2O3 into ZrO2 at various % mol of 4.5; 8 and 10. This research aims to understand the crystal structure, morphological analysis and particle size analysis. The X-ray diffraction analysis equipped with Le Bail refinement found that the prepared ZrO2 is in two phases of the monoclinic and tetragonal structure, and the structure changed to cubic after yttrium ions doping. However, the monoclinic and tetragonal still exist. Various yttrium concentrations provide different morphology, in which 4.5 YSZ shows a blocking phase indicated as the presence of impurities. The blocking phase seems to prevent sintering and allows a line crack on the material layer. Meanwhile, 8YSZ and 10YSZ show homogeneous morphology and without provides a line crack. The mean particle size after sintering is in between 1.1 - 1.5 μm.

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

    NARCIS (Netherlands)

    Zhu, Jianjun; Ommen, van Jan G.; Knoester, A.; Lefferts, Leon

    2005-01-01

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

  16. Influence of yttrium iron garnet thickness and heater opacity on the nonlocal transport of electrically and thermally excited magnons

    NARCIS (Netherlands)

    Shan, Juan; Cornelissen, Ludo J.; Vlietstra, Nynke; Ben Youssef, Jamal; Kuschel, Timo; Duine, Rembert; Van Wees, Bart J.

    2016-01-01

    We studied the nonlocal transport behavior of both electrically and thermally excited magnons in yttrium iron garnet (YIG) as a function of its thickness. For electrically injected magnons, the nonlocal signals decrease monotonically as the YIG thickness increases. For the nonlocal behavior of the t

  17. Yttrium modifying influence on the shape and amount of nonmetallic inclusions in the austenitic high alloy steel

    Directory of Open Access Journals (Sweden)

    Андрій Володимирович Патюпкін

    2016-07-01

    Full Text Available Yttrium influence on the form and amount of non-metallic inclusions in steel 06H23N18M5 was studied. It has been found that yttrium binds oxygen and other elements into heterogeneous compounds, it resulting in the transition of impurities into passive state. Oxide inclusions, sulfide inclusions and globules formed as a result of steel components reactions with oxygen, sulfur and nitrogen dissolved in metal are mostly found in the structure. It was found that by modifying and refining austenitic steels with yttrium service properties of the deposited layer can be adjusted. X-ray diffraction and X-ray spectrum analysis revealed that the modified steel 06H23N18M5 + 0.02% Y has a heterogeneous structure with uniformly distributed inclusions of σ-phase and composite carbides (Fe, Cr, Mo 23C6. It is possible that Y modification resulted in the appearance of chemically resistant intermetallic σ-phase in these steels, for nucleation was facilitated by increasing the number of crystallization centers as dispersed primary yttrium oxy-sulfide compounds

  18. Pengaruh Penambahan Yttrium Terhadap Struktur Mikro, Sifat Mekanik Dan Ketahanan Termal Pada Paduan Mg-6zn Sebagai Aplikasi Engine Block

    Directory of Open Access Journals (Sweden)

    Indra Bagas Pramasta

    2015-03-01

    Full Text Available Penelitian ini bertujuan untuk menganalisis pengaruh variasi penambahan Yttrium (Y terhadap struktur mikro, kekerasan dan ketahanan termal pada paduan magnesium – zinc. Magnesium (Mg telah menjadi solusi untuk pengembangan material ringan. Paduan magnesium yang memiliki rasio kekuatan material berbanding massa material yang tinggi membuatnya baik digunakan pada aplikasi otomotif seperti steering wheel, gearbox house, seat frames dan cylinder block. Penelitian ini memadukan magnesium-zinc-yttrium dalam komposisi yang berbeda. Komposisi yttriumnya adalah 0,5% wt ; 2% wt dan 4% wt. Pengecoran yang dilakukan adalah pengecoan konvensional dengan temperatur melting 750°C dengan waktu penahanan 60 menit. Pengujian yang dilakukan yaitu pengujian struktur mikro, identifikasi fasa, komposisi fasa, ketahanan termal dan kekerasan. Berdasarkan pengujian yang dilakukan menunjukkan bahwa yttrium dapat menyebabkan berubahnya struktur mikro dan fasa serta meningkatkan kekerasan dan ketahanan termal pada sampel. Hasil analisa menunjukkan 4 fasa dominan yang muncul pada sampel yaitu α-Mg, MgZn, Mg3YZn6 dan Mg3Y2Zn3. Kekerasan tertinggi adalah 74 BHN pada sampel 4% wt yttrium dan rata-rata sampel dapat digunakan sampai temperatur dibawah 250 ͦC.

  19. 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

  20. Long-Term Palliative Effect of Stenting in Gastric Outlet Obstruction Due to Transarterial Chemoembolization with Yttrium-90 in a Patient with Metastatic Neuroendocrine Tumor

    Science.gov (United States)

    Caglar, Erkan; Doğusoy, Gulen; Kabasakal, Levent; Dobrucali, Ahmet

    2016-01-01

    Internal radioembolization with yttrium-90 is a promising treatment method, predominantly for liver tumors. However, the shifting of yttrium-90-loaded spherules into the arteries and veins that supply the duodenum and stomach, leading to ulceration, hemorrhage, perforation, and outlet obstruction of these organs, is one of the major undesirable consequences of this technique. We report a case of gastric outlet obstruction (GOO) due to antropyloric stenosis with ulceration, edema, and inflammation following transarterial yttrium-90 treatment for a metastatic neuroendocrine tumor in a 58-year-old man. Stenting was used for palliation in this case. GOO improved after stenting and recovery of oral intake was permanent after stent removal. PMID:27353368

  1. Effect of Yttrium Pre-Implantation on Implantation Behavior of Ti-6Al-4V Alloy in Nitrogen Plasma Immersion Ion Implantation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to increase the peak depth of nitrogen atoms during the nitrogen plasma immersion ion implantation of Ti-6Al-4V alloy, the rare earth metal yttrium was applied. In the experiment, yttrium and nitrogen ions were implanted under the voltage of 20 and 30 kV, respectively. In the samples with yttrium pre-implantation for 30 min, the Auger electron spectroscopy(AES) analysis shows that the peak depth of the nitrogen atoms increases from 50 up to 100 nm. It can also be seen from the tribological tests that the wear resistance of these samples is increased remarkably.

  2. Advances in SPECT for Optimizing the Liver Tumors Radioembolization Using Yttrium-90 Microspheres.

    Science.gov (United States)

    Roshan, Hoda Rezaei; Azarm, Ahmadreza; Mahmoudian, Babak; Islamian, Jalil Pirayesh

    2015-01-01

    Radioembolization (RE) with Yttrium-90 ((90)Y) microspheres is an effective treatment for unresectable liver tumors. The activity of the microspheres to be administered should be calculated based on the type of microspheres. Technetium-99m macroaggregated albumin ((99m)Tc-MAA) single photon emission computed tomography/computed tomography (SPECT/CT) is a reliable assessment before RE to ensure the safe delivery of microspheres into the target. (90)Y bremsstrahlung SPECT imaging as a posttherapeutic assessment approach enables the reliable determination of absorbed dose, which is indispensable for the verification of treatment efficacy. This article intends to provide a review of the methods of optimizing (90)Y bremsstrahlung SPECT imaging to improve the treatment efficacy of liver tumor RE using (90)Y microspheres.

  3. Chemical solution deposition of ferroelectric yttrium-doped hafnium oxide films on platinum electrodes

    Science.gov (United States)

    Starschich, S.; Griesche, D.; Schneller, T.; Waser, R.; Böttger, U.

    2014-05-01

    Ferroelectric hafnium oxide films were fabricated by chemical solution deposition with a remnant polarization of >13 μC/cm2. The samples were prepared with 5.2 mol. % yttrium-doping and the thickness varied from 18 nm to 70 nm. The hafnium oxide layer was integrated into a metal-insulator-metal capacitor using platinum electrodes. Due to the processing procedure, no thickness dependence of the ferroelectric properties was observed. To confirm the ferroelectric nature of the deposited samples, polarization, capacitance, and piezoelectric displacement measurements were performed. However, no evidence of the orthorhombic phase was found which has been proposed to be the non-centrosymmetric, ferroelectric phase in HfO2.

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

    Directory of Open Access Journals (Sweden)

    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

  5. Luminescent Properties of Eu3+-Doped Yttrium Oxide Chloride Embedded in Nanoporous Glass

    Institute of Scientific and Technical Information of China (English)

    曾小青; 林凤英; 干福熹; 袁绥华

    2002-01-01

    The photoluminescence of Eu3+-doped yttrium oxide chloride embedded in nanoporous glass has been observed. In comparison with those in the powder phosphor, the emission lines of Eu3+ ions become much broader and blueshift was observed in the lines due to 5D0 → 7F2 transitions and the Eu-O charge transfer excitation band. The ratio intensities of the 5 D0 → 7 F1 transitions to the 5Do → 7 F2 transitions of Eu3+ ion become higher and change at different excitation wavelengths, such as 393nm and 254nm. The two excitation wavelengths belong to the 4f → 4f transition of the Eus+ ion and the Eu-O charge transfer, respectively. This material may be developed into a new luminescent glass.

  6. Luminescence of color centers formed in alkali-earth-doped yttrium orthoaluminate crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kawabe, Y. [Chitose Institute of Science and Technology, 758-65 Bibi, Chitose, Hokkaido 066-8655 (Japan) and CREST, Japan Science and Technology Agency, 758-65 Bibi, Chitose, Hokkaido 066-8655 (Japan)]. E-mail: y-kawabe@photon.chitose.ac.jp; Yamanaka, A. [Chitose Institute of Science and Technology, 758-65 Bibi, Chitose, Hokkaido 066-8655 (Japan); CREST, Japan Science and Technology Agency, 758-65 Bibi, Chitose, Hokkaido 066-8655 (Japan); Horiuchi, H. [Chitose Institute of Science and Technology, 758-65 Bibi, Chitose, Hokkaido 066-8655 (Japan); CREST, Japan Science and Technology Agency, 758-65 Bibi, Chitose, Hokkaido 066-8655 (Japan); Takashima, H. [Chitose Institute of Science and Technology, 758-65 Bibi, Chitose, Hokkaido 066-8655 (Japan); Hanamura, E. [Chitose Institute of Science and Technology, 758-65 Bibi, Chitose, Hokkaido 066-8655 (Japan); CREST, Japan Science and Technology Agency, 758-65 Bibi, Chitose, Hokkaido 066-8655 (Japan)

    2006-12-15

    Alkali-earth-doped yttrium orthoaluminate crystals grown in a reducing atmosphere are found to show bright photoluminescence (PL) in visible wavelength regions under the excitation by UV light source. From the results of transmission, PL, PL excitation and time-resolved PL spectra for the samples with different types and concentrations of dopants and the comparison to the results for the samples grown under different conditions, the origin of principal emission is determined to be color centers stabilized by heterovalent ions. The observed fast lifetime and high quantum yield of the luminescence can be explained by dipole-allowed transition between the levels localized in a vacancy. Comparing the effects on the optical properties from several types of dopant ions and taking influence from the UV irradiation into account, a model for the structure of emission centers is proposed.

  7. 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.

  8. Flux-gate magnetic field sensor based on yttrium iron garnet films for magnetocardiography investigations

    Science.gov (United States)

    Vetoshko, P. M.; Gusev, N. A.; Chepurnova, D. A.; Samoilova, E. V.; Syvorotka, I. I.; Syvorotka, I. M.; Zvezdin, A. K.; Korotaeva, A. A.; Belotelov, V. I.

    2016-08-01

    A new type of f lux-gate vector magnetometer based on epitaxial yttrium iron garnet films has been developed and constructed for magnetocardiography (MCG) investigations. The magnetic field sensor can operate at room temperature and measure MCG signals at a distance of about 1 mm from the thoracic cage. The high sensitivity of the sensor, better than 100 fT/Hz1/2, is demonstrated by the results of MCG measurements on rats. The main MCG pattern details and R-peak on a level of 10 pT are observed without temporal averaging, which allows heart rate anomalies to be studied. The proposed magnetic sensors can be effectively used in MCG investigations.

  9. 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.

  10. 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; 褚连青; 宋俊亭

    2002-01-01

    Phase analysis for the coated surface with B4C and Y2O3 of cemented carbid e WC-20Co in vacuum-heating was carried out by high-temperature X-ray diffra ction from ambient temperature to 1300 ℃. The results show that, the high-conc entration active boron atoms are released from the boron-supply agent B4C loc ated on the alloy surface and diffused into the γ-phase, leading to forming th e three-element boron-bearing compound W2Co21B6 beside forming boron -bearing compounds on the blank surface. By contrast with boronising only, the element yttrium in boronization broadens the boronising temperature range during vacuum-sintering, catalyzes the decarbonisation decomposition of B4C and prom otes diffusion of active boron atoms into the bulk of WC-Co.

  11. Nonlinear dynamics of three-magnon process driven by ferromagnetic resonance in yttrium iron garnet

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, R. O. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Centro Interdisciplinar de Ciências da Natureza, Universidade Federal da Integração Latino-Americana, 85867-970 Foz do Iguaçu, PR (Brazil); Holanda, J.; Azevedo, A.; Rezende, S. M., E-mail: rezende@df.ufpe.br [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Vilela-Leão, L. H. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Centro Acadêmico do Agreste, Universidade Federal de Pernambuco, 55002-970 Caruaru, PE (Brazil); Rodríguez-Suárez, R. L. [Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago (Chile)

    2015-05-11

    We report an investigation of the dynamics of the three-magnon splitting process associated with the ferromagnetic resonance (FMR) in films of the insulating ferrimagnet yttrium iron garnet (YIG). The experiments are performed with a 6 μm thick YIG film close to a microstrip line fed by a microwave generator operating in the 2–6 GHz range. The magnetization precession is driven by the microwave rf magnetic field perpendicular to the static magnetic field, and its dynamics is observed by monitoring the amplitude of the FMR absorption peak. The time evolution of the amplitude reveals that if the frequency is lowered below a critical value of 3.3 GHz, the FMR mode pumps two magnons with opposite wave vectors that react back on the FMR, resulting in a nonlinear dynamics of the magnetization. The results are explained by a model with coupled nonlinear equations describing the time evolution of the magnon modes.

  12. Raman spectroscopic characterization of ZrO2 and yttrium stabilized zirconias

    DEFF Research Database (Denmark)

    Kjerulf-Jensen, N.; Berg, Rolf W.; Poulsen, Finn Willy

    1996-01-01

    forward. The spectral features of the Raman spectra do furthermore not only depend on the phase composition, but also depend on the frequency of the excitation, temperature of experiment and texture/orientation of zirconia crystallites under investigation. These effects are illustrated by Raman spectra...... obtained on ZrO2 and YSZ (Yttrium Stabilized Zirconias) in the range 8, 12 and 18 mol% Y2O3 and 4 mol% Yb2O3 + 4 mol% Y2O3. The peak positions in the spectra of 8 mol% YSZ (Viking) are lowered by up to 20 cm-1 upon heating to 700 oC. Intense fluorescence/luminescence bands at 1000-1600 cm-1 were observed...

  13. Investigation of nanostructural, thermal and magnetic properties of yttrium iron garnet synthesized by mechanochemical method

    Science.gov (United States)

    Karami, M. A.; Shokrollahi, H.; Hashemi, B.

    2012-09-01

    This paper focuses on the magnetic, structural and thermal properties of mechanically alloyed Y2O3/α-Fe2O3 mixed powders and investigates the effects of the mechanical milling and heat treatment on the synthesis of yttrium iron garnet from the primary materials. The morphological and structural studies were carried out by scanning electron microscope and X-ray diffraction, respectively. The thermal activities were measured by differential thermal analysis. The magnetic properties were studied by vibrating sample magnetometer. The results showed that high-energy milling does not lead to the garnet formation and even does not decrease the temperature of the garnet formation. Furthermore, the orthoferrite phase can be achieved slightly during the milling process (up to 96 h) and completely by the heat treatment at lower temperatures (850 °C).

  14. The development, commercialization, and clinical context of yttrium-90 radiolabeled resin and glass microspheres.

    Science.gov (United States)

    Westcott, Mark A; Coldwell, Douglas M; Liu, David M; Zikria, Joseph F

    2016-01-01

    Selective internal radiation therapy has emerged as a well-accepted therapeutic for primary and metastatic hepatic malignancies. This therapeutic modality requires the combined efforts of multiple medical disciplines to ensure the safe delivery of yttrium-90 ((90)Y)-labeled microspheres. The development of this therapy followed decades of clinical research involving tumor vascularity and microsphere development. Today, it is essential that treating physicians have a thorough understanding of hepatic tumor vascularity and (90)Y microsphere characteristics before undertaking this complex intervention. This review explores the contributions of early investigators of this therapy, as well as the development, US Food and Drug Administration approval, manufacturing process, and attributes of the 2 commercially available (90)Y radiolabeled microsphere device to clarify the key physical differences between the products.

  15. Energy and average power scalable optical parametric chirped-pulse amplification in yttrium calcium oxyborate.

    Science.gov (United States)

    Liao, Zhi M; Jovanovic, Igor; Ebbers, Chris A; Fei, Yiting; Chai, Bruce

    2006-05-01

    Optical parametric chirped-pulse amplification (OPCPA) in nonlinear crystals has the potential to produce extremes of peak and average power but is limited either in energy by crystal growth issues or in average power by crystal thermo-optic characteristics. Recently, large (7.5 cm diameter x 25 cm length) crystals of yttrium calcium oxyborate (YCOB) have been grown and utilized for high-average-power second-harmonic generation. Further, YCOB has the necessary thermo-optic properties required for scaling OPCPA systems to high peak and average power operation for wavelengths near 1 microm. We report what is believed to be the first use of YCOB for OPCPA. Scalability to higher peak and average power is addressed.

  16. Crystal Structure of Lithium Yttrium Borate LiY6O5(BO3)3

    Institute of Scientific and Technical Information of China (English)

    GAO Jian-Hua

    2006-01-01

    Single crystals of LiY6O5(BO3)3 were obtained by the flux method and its structure was determined by a four-circle automatic diffractometer with a MoKa radiation. It crystallizes in monoclinic, space group P21/n with a = 8.330(3), b = 15.444(4), c = 8.780(3) (A), β = 91.85(3)°, V =1129.0(6) (A)3, Z = 4, Mr= 796.83, F(000) = 1456, μ = 30.567 mm-1, Dc = 4.688 g/cm3, the final R =0.0722 and wR = 0.1304. It exhibits a three-dimensional framework of yttrium-oxygen polyhedra interconnected by common edges and corners. B and Li atoms are located in the planes and cavities formed by oxygen atoms, respectively.

  17. 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.

  18. Complete eradication of hepatic metastasis from colorectal cancer by Yttrium-90 SIRT.

    Science.gov (United States)

    Garrean, Sean; Muhs, Amanda; Bui, James T; Blend, Michael J; Owens, Charles; Helton, William S; Espat, N Joseph

    2007-06-07

    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 chemo-refractory 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.

  19. 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.

  20. 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.

  1. The development, commercialization, and clinical context of yttrium-90 radiolabeled resin and glass microspheres

    Directory of Open Access Journals (Sweden)

    Mark A. Westcott, MD

    2016-10-01

    Full Text Available Selective internal radiation therapy has emerged as a well-accepted therapeutic for primary and metastatic hepatic malignancies. This therapeutic modality requires the combined efforts of multiple medical disciplines to ensure the safe delivery of yttrium-90 (90Y-labeled microspheres. The development of this therapy followed decades of clinical research involving tumor vascularity and microsphere development. Today, it is essential that treating physicians have a thorough understanding of hepatic tumor vascularity and 90Y microsphere characteristics before undertaking this complex intervention. This review explores the contributions of early investigators of this therapy, as well as the development, US Food and Drug Administration approval, manufacturing process, and attributes of the 2 commercially available 90Y radiolabeled microsphere device to clarify the key physical differences between the products.

  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. 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.

  4. Light emission of double-walled carbon nanotube filaments doped with yttrium and europium

    Institute of Scientific and Technical Information of China (English)

    SHU QinKe; WU DeHai; WANG KunLin; WEI JinQuan; ZHU HongWei; LI XinMing; CHEN Xi; JIA Yi; GUI XuChun; XU ErYang

    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.

  5. Hybrid yttrium iron garnet-ferromagnet structures for spin-wave devices

    Energy Technology Data Exchange (ETDEWEB)

    Papp, A., E-mail: apapp@nd.edu [Center for Nano Science and Technology and Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Pázmány Péter Catholic University, Faculty of Information Technology, Budapest 1088 (Hungary); Porod, W., E-mail: porod@nd.edu; Csaba, G., E-mail: gcsaba@nd.edu [Center for Nano Science and Technology and Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

    2015-05-07

    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.

  6. Hydrogen gas sensor based on palladium and yttrium alloy ultrathin film

    Science.gov (United States)

    Yi, Liu; You-ping, Chen; Han, Song; Gang, Zhang

    2012-12-01

    Compared with the other hydrogen sensors, optical fiber hydrogen sensors based on thin films exhibits inherent safety, small volume, immunity to electromagnetic interference, and distributed remote sensing capability, but slower response characteristics. To improve response and recovery rate of the sensors, a novel reflection-type optical fiber hydrogen gas sensor with a 10 nm palladium and yttrium alloy thin film is fabricated. The alloy thin film shows a good hydrogen sensing property for hydrogen-containing atmosphere and a complete restorability for dry air at room temperature. The variation in response value of the sensor linearly increases with increased natural logarithm of hydrogen concentration (ln[H2]). The shortest response time and recovery response time to 4% hydrogen are 6 and 8 s, respectively. The hydrogen sensors based on Pd0.91Y0.09 alloy ultrathin film have potential applications in hydrogen detection and measurement.

  7. 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.

  8. 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.

  9. The rise of metal radionuclides in medical imaging: copper-64, zirconium-89 and yttrium-86.

    Science.gov (United States)

    Ikotun, Oluwatayo F; Lapi, Suzanne E

    2011-04-01

    Positron emission tomography, with its high sensitivity and resolution, is growing rapidly as an imaging technology for the diagnosis of many disease states. The success of this modality is reliant on instrumentation and the development of effective and novel targeted probes. Initially, research in this area was focused on what we will define in this article as 'standard' PET isotopes (carbon-11, nitrogen-13, oxygen-15 and fluorine-18), but the short half-lives of these isotopes limit radiopharmaceutical development to those that probe rapid biological processes. To overcome these limitations, there has been a rise in nonstandard isotope probe development in recent years. This review focuses on the biological probes and processes that have been examined, in additiom to the preclinical and clinical findings with nonstandard radiometals: copper-64, zirconium-89, and yttrium-86.

  10. 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)

  11. Eu{sup 3+} doped yttrium oxysulfide quantum structures-structural, optical and electronic properties

    Energy Technology Data Exchange (ETDEWEB)

    Thirumalai, J.; Chandramohan, R. [Sree Sevugan Annamalai College, Department of Physics (India)], E-mail: chandramohan_rm@rediffmail.com; Sekar, M. [Indira Gandhi Centre for Atomic Research, Advanced Materials Laboratory, Materials Science Division (India); Rajachandrasekar, R. [Department of Atomic Energy, CAR Project, BARC F-Facilities (India)

    2008-03-15

    Small particles of trivalent europium doped yttrium oxysulfide nanocrystals ({phi} {approx} 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 ({approx}260 nm) and Eu{sup 3+}-X{sup 2-} ligand (O{sup 2-}/S{sup 2-}) charge transfer ({approx}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.

  12. Structural and electrical studies of sol-gel synthesized nanocrystalline hexagonal yttrium iron manganite ceramics

    Science.gov (United States)

    Touthang, Jangkhohao; Maisnam, Mamata

    2017-03-01

    Hexagonal yttrium manganites, YMnO3, are interesting materials for their multiferroic behavior. Substituting suitable cations either at the Y-site or Mn-site offers great opportunities to produce a variety of manganites and tune their properties. Nanocrystalline yttrium iron manganites with the compositional formula Y1‑xFexMnO3, x = 0.0, 0.10, 0.15, 0.20 and 0.25, were synthesized by sol-gel autocombustion method. The prepared samples were heated at 1100∘C for 1 h. Another set of samples with compositional formula YFexMn1‑xO3, x = 0.0, 0.10, 0.15, 0.20 and 0.25, were also synthesized by the same method and heated at 1100∘C for 1 h. Various characterizations were done on these manganite systems synthesized by substituting iron at different sites. X-ray diffraction (XRD) technique studied the structure of the samples and analysis of XRD patterns confirmed the formation of hexagonal phase in the samples. Structural parameters such as lattice constants, crystallite size, theoretical density, etc. were determined using the XRD data. The unit cell dimensions have been found to agree with the standard data and the Debye-Scherrer crystallite size obtained from XRD data ranges from 42 nm to 77 nm. The room temperature frequency variations of electrical properties such as dielectric constant, dielectric loss and AC conductivity were measured in the range of 100 Hz-2 MHz and the variations showed a dispersive behavior for all the samples. The various measurements and the results obtained were studied and discussed in the paper.

  13. 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.

  14. Facile wet chemical route synthesis, characterization and spectroscopic analysis of yttrium-doped lanthanum phosphate nanoparticles

    Science.gov (United States)

    Raina, Bindu; Verma, Seema; Bamzai, K. K.

    2017-09-01

    Pure and yttrium-doped lanthanum phosphate nanoparticles were successfully prepared through a simple one-step co-precipitation method. The phase, morphology and composition of Y x La1 - x PO4 powders with varying dopant concentration ( x = 0.00, 0.01, 0.03, 0.05) were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) supplemented with energy dispersive X-ray (EDX) analysis and transmission electron microscopy (TEM). XRD analysis reveals the nanocrystalline nature with monoclinic monazite crystal system. SEM and TEM micrographs indicate the formation of ultrafine particles depicting spherical morphology with slight agglomeration and cluster formation. Fourier transform infrared spectroscopy (FTIR) signifies the presence of water vibration modes in a particular wave number along with phosphate group and a slight shift in wave numbers when yttrium is induced into lanthanum phosphate. Thermogravimetric analysis (TGA) reveals that the structural phase transition takes place above 800 °C. Raman spectra gives insight into the order-disorder in the system and shows relevant peaks for symmetric and anti-symmetric of PO4 3-, O-P-O bending mode, rare earth—oxygen vibrations. The fluorescence spectra of the grown compositions were investigated. The results show strong emission peaks at 270 nm excitation, whose intensity increases along with the increasing dopant concentration. Ultraviolet (UV) spectroscopy reveals that the absorption bands lie in the ultraviolet range and the bands are particularly sensitive to the incorporation of dopant ion, i.e., with effect of doping bands shift towards the lower wavelength side.

  15. 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.

  16. Microstructural characteristics and second-phase particles in yttrium-bearing Fe-10Ni-7Mn martensitic steels

    Institute of Scientific and Technical Information of China (English)

    F. Forghani; M. Nili-Ahmadabadi

    2014-01-01

    In this study, the microstructure and second-phase particles in yttrium (0.05 wt.%and 0.8 wt.%) bearing Fe-10Ni-7Mn steels were characterized. The results of X-ray analysis as well as scanning electron microscopy coupled with energy dispersive X-ray spectroscopy indicated the formation of (Fe, Ni, Mn)17Y2 precipitates with hexagonal structure in a Fe-10Ni-7Mn-0.8Y (wt.%) alloy. Lattice parameters of these precipitates were calculated as follows:a=0.8485 nm and c=0.8274 nm. Formation of Y2O3 sub-micron particles was also confirmed in both yttrium bearing steels via electrolytic phase extraction method. The effect of these precipitates on the prior austenite grain size was investigated. The results revealed that these precipitates had an effective role in controlling the prior austenite grain size.

  17. Influence of cyclic frequency on oxidation behavior of K38 superalloy with yttrium additions at 1 273 K

    Institute of Scientific and Technical Information of China (English)

    YU Ping; WANG Wen; WANG Fuhui

    2011-01-01

    Cyclic oxidation test is a fundamental method to assess lifetime of materials in high temperature environment. Cycle length or cyclic frequency is one important variable in cyclic oxidation testing. In present work, cyclic oxidation tests were performed on cast K38 alloys with 0 wt.%, 0.1 wt.%, and 0.5 wt.% yttrium additions at 1 273 K respectively. Two cyclic frequencies were used to investigate the influence of cycle length (1 h vs. 20 h) on the high temperature oxidation behavior of superalloy. The results showed that the degradation of cast K38alloy critically was dependent on the cyclic frequency. The yttrium addition was beneficial to reducing scale-growth rate, improving the scale adhesion and stress releasing, thereby increased the spallation resistance. It could be drawn that the effect of cyclic frequency was highly dependent on the scale adherence to the substrate.

  18. The Influence of Yttrium Isopropoxide on the Mechanical Properties of SiCW-reinforced AlN Ceramics

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By using self-made metal-alkoxide yttrium isopropoxide as a sintering additive and disperser of whisker,the SiC whisker reinforced AlN ceramics was prepared.Its apparent density is 99.5 percent of the theoretical density;its flexural strength and fracture toughness are 681 MPa and 5.21 MPa*m1/2 respectively.Comparing the result with that by applying Y2O3 powder as a sintering additive,the flexural strength is increased by 25% and the fracture toughness is increased by 33%.The dispersity of whisker by increased yttrium isopropoxide is significantly better than that by Triton X-100.

  19. Bonding mechanism of a yttrium iron garnet film on Si without the use of an intermediate layer

    Energy Technology Data Exchange (ETDEWEB)

    Pantzas, Konstantinos, E-mail: konstantinos.pantzas@lpn.cnrs.fr [CNRS-LPN, Route de Nozay, F-91460 Marcoussis (France); Institut P' , CNRS-Université de Poitiers - ENSMA - UPR 3346, SP2MI - Téléport 2 Bd Marie Pierre Curie, B.P. 30179, F-86962, Futuroscope Chasseneuil Cedex (France); Patriarche, Gilles; Talneau, Anne [CNRS-LPN, Route de Nozay, F-91460 Marcoussis (France); Youssef, Jamal Ben [Laboratoire de Magnetisme de Bretagne, 6 avenue Le Gorgeu, 29238 Brest Cedex 3 (France)

    2014-10-06

    Direct bonding of yttrium iron garnet (YIG) on silicon without the use of an intermediate bonding layer is demonstrated and characterized using scanning transmission electron microscopy and energy-dispersive x-ray spectroscopy. During the bonding experiment, the garnet is reduced in the presence of oxide-free silicon. As a result, a 5 nm thick SiO{sub 2}/amorphous-YIG bilayer is formed and welds the garnet to silicon.

  20. Separation of yttrium (III) from lanthanoids (III) by solvent extraction with substituted N-Alkylcarbonyl-N-phenylhydroxylamines

    Energy Technology Data Exchange (ETDEWEB)

    Haraguchi, K.; Ogata, T.; Nakagawa, K. [Hokkaido National Industrial Research Institute, Sapporo (Japan); Saitoh, T.; Kamidate, T.; Watanabe, H. [Hokkaido University, Sapporo, (Japan). Faculty of Engineering

    1996-12-31

    A series of substituted N-alkylcarbonyl-N-phenylhydroxylamines(R-PHAs) were synthesized and utilized for the extraction of yttrium(III) and lanthanoids(III) in order to obtain effective extractants for the separation of yttrium(III) from the lanthanoids(III) and the mutual separation of the lanthanoids(III). The distribution ratio of yttrium(III) and the lanthanoids(III) between the carbon tetrachloride and the aqueous phases was measured as functions of the pH and the extractant concentration at 298 K at an ionic strength of 0.1 (NaNO{sub 3}). Yttrium(III) and the lanthanoids(III) were extracted with R-PHAs(HL) as self-adducted chelates of the form, ML{sub 3}(HL){sub x}, where `x` is 1, 2 or 3 depending on the extraction system. The extractability of the metal ions decreased in the order of R-PHA having a primary, a secondary and a tertiary alkyl substituent attached to the carbonyl group because of the steric hindrance of the alkyl group. The separation factors for both Yb/Eu and Yb/Y pairs increased with increasing branching of the alkyl group of R-PHA. The excellent selectivity of R-PHAs having a tertiary alkyl group was attributable to a greater inductive effect of the tertiary alkyl group than those of the primary and secondary alkyl groups. The substituents at the phenyl group of R-PHAs gave no significant effect on the selectivity, while the extractability was enhanced considerably by introduction of electron withdrawing substituents at appropriate positions of the phenyl group of R-PHAs. (authors) 10 refs., 3 tabs., 1 fig.

  1. Coupling of erbium dopants to yttrium orthosilicate photonic crystal cavities for on-chip optical quantum memories

    Energy Technology Data Exchange (ETDEWEB)

    Miyazono, Evan; Zhong, Tian; Craiciu, Ioana; Kindem, Jonathan M.; Faraon, Andrei, E-mail: faraon@caltech.edu [T. J. Watson Laboratory of Applied Physics, California Institute of Technology, 1200 E California Blvd, Pasadena, California 91125 (United States)

    2016-01-04

    Erbium dopants in crystals exhibit highly coherent optical transitions well suited for solid-state optical quantum memories operating in the telecom band. Here, we demonstrate coupling of erbium dopant ions in yttrium orthosilicate to a photonic crystal cavity fabricated directly in the host crystal using focused ion beam milling. The coupling leads to reduction of the photoluminescence lifetime and enhancement of the optical depth in microns-long devices, which will enable on-chip quantum memories.

  2. Coupling of erbium dopants to yttrium orthosilicate photonic crystal cavities for on-chip optical quantum memories

    CERN Document Server

    Miyazono, Evan; Craiciu, Ioana; Kindem, Jonathan M; Faraon, Andrei

    2016-01-01

    Erbium dopants in crystals exhibit highly coherent optical transitions well suited for solid-state optical quantum memories operating in the telecom band. Here we demonstrate coupling of erbium dopant ions in yttrium orthosilicate to a photonic crystal cavity fabricated directly in the host crystal using focused ion beam milling. The coupling leads to reduction of the photoluminescence lifetime and enhancement of the optical depth in microns-long devices, which will enable on-chip quantum memories.

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

    Science.gov (United States)

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

    2016-05-01

    Understanding how engineered nanoparticles (ENPs) interact with natural organic acids is important to ecological risk assessment of ENPs, but this interaction remains poorly studied. Here, we investigate the dispersion stability, ion release, and toxicity of yttrium oxide nanoparticles (nY2O3) suspensions after exposure to two low molecular weight natural organic acids (LOAs), namely benzoic acid and gallic acid. We find that in the presence of LOAs the nY2O3 suspensions become more stable with surface zeta potential more positive or negative, accompanied by small agglomerated size. LOA interaction with nY2O3 is shown to promote the release of dissolved yttrium from the nanoparticles, depending on the concentrations of LOAs. Toxic effects of the nY2O3 suspensions incubated with LOAs on Scenedesmus obliquus as a function of their mixture levels show three types of signs: stimulation, inhibition, and alleviation. The mechanism of the effects of LOAs on the nY2O3 toxicity may be mainly associated with the degree of agglomeration, particle-induced oxidative stress, and dissolved yttrium. Our results stressed the importance of LOA impacts on the fate and toxicity of ENPs in the aquatic environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Visible to near-infrared supercontinuum generation in yttrium orthosilicate bulk crystal and ion implanted planar waveguide.

    Science.gov (United States)

    Xiang, Bingxi; Ren, Xikui; Ruan, Shuangchen; Wang, Lei; Yan, Peiguang; Han, Huangpu; Wang, Meng; Yin, Jinde

    2016-08-16

    This paper reports on the supercontinuum generation in yttrium orthosilicate bulk crystal and 6-mm-long ion implanted planar waveguide. The waveguide is fabricated by 6 MeV oxygen ions implantation with fluence of 5 × 10(14) ions/cm(2) at room temperature. The yttrium orthosilicate bulk crystal and waveguide are pumped using a mode-locked Ti:Sapphire laser with a center wavelength of 800 nm. The generated broadest supercontinuum spans 720 nm (at -30 dB points) from 380 to 1100 nm in bulk crystal and 510 nm (at -30 dB points) from 490 to 1000 nm in ion implanted waveguide, respectively. Compared to the bulk crystal, the ion implanted waveguide requires almost three orders of magnitude lower pump power to achieve a similar level of broadening. The supercontinuum is generated in the normal dispersion regime and exhibits a relatively smooth spectral shape. Our research findings indicate that ion implantation is an efficient method to produce waveguide in yttrium orthosilicate crystal for low-threshold supercontinuum generation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jinlong [Corrosion and Protection Laboratory, Key Laboratory of Superlight Materials and Surface Technology (Harbin Engineering University), Ministry of Education, Harbin 150001 (China); Laboratory of Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Chen, Minghui, E-mail: mhchen@imr.ac.cn [Laboratory of Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Yang, Lanlan; Liu, Li; Zhu, Shenglong [Laboratory of Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Wang, Fuhui [Corrosion and Protection Laboratory, Key Laboratory of Superlight Materials and Surface Technology (Harbin Engineering University), Ministry of Education, Harbin 150001 (China); Laboratory of Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Meng, Guozhe [Corrosion and Protection Laboratory, Key Laboratory of Superlight Materials and Surface Technology (Harbin Engineering University), Ministry of Education, Harbin 150001 (China)

    2016-03-15

    Graphical abstract: - Highlights: • Effect of Y addition on oxidation of nanocrystalline coating is studied. • Y addition delays transformation of q-Al{sub 2}O{sub 3} to a-Al{sub 2}O{sub 3} during oxidation. • Y addition prevents scale rumpling. • Y segregates at grain boundaries of the nanocrystalline coating. • Y retards the transportation of Ta thus reduces its oxidation. - Abstract: The effect of yttrium addition on isothermal oxidation at 1050 °C of a sputtered nanocrystalline coating with moderate amount of tantalum in composition was investigated. Results indicate that yttrium addition delays transformation of metastable θ-Al{sub 2}O{sub 3} to equilibrium α-Al{sub 2}O{sub 3} grown on the nanocrystalline coatings. It prevents scale rumpling and promotes the formation of oxide pegs at interface between the oxide scale and the underlying coating. Besides, yttrium prefers to segregate at grain boundaries of the nanocrystalline coating and retards the outward transportation of tantalum from coating to oxide scale, thus reducing the excessive oxidation of tantalum.

  6. Visible to near-infrared supercontinuum generation in yttrium orthosilicate bulk crystal and ion implanted planar waveguide

    Science.gov (United States)

    Xiang, Bingxi; Ren, Xikui; Ruan, Shuangchen; Wang, Lei; Yan, Peiguang; Han, Huangpu; Wang, Meng; Yin, Jinde

    2016-08-01

    This paper reports on the supercontinuum generation in yttrium orthosilicate bulk crystal and 6-mm-long ion implanted planar waveguide. The waveguide is fabricated by 6 MeV oxygen ions implantation with fluence of 5 × 1014 ions/cm2 at room temperature. The yttrium orthosilicate bulk crystal and waveguide are pumped using a mode-locked Ti:Sapphire laser with a center wavelength of 800 nm. The generated broadest supercontinuum spans 720 nm (at ‑30 dB points) from 380 to 1100 nm in bulk crystal and 510 nm (at ‑30 dB points) from 490 to 1000 nm in ion implanted waveguide, respectively. Compared to the bulk crystal, the ion implanted waveguide requires almost three orders of magnitude lower pump power to achieve a similar level of broadening. The supercontinuum is generated in the normal dispersion regime and exhibits a relatively smooth spectral shape. Our research findings indicate that ion implantation is an efficient method to produce waveguide in yttrium orthosilicate crystal for low-threshold supercontinuum generation.

  7. Influence of Yttrium Ion-Implantation on the Growth Kinetics and Micro-Structure of NiO Oxide Film

    Institute of Scientific and Technical Information of China (English)

    JIN Huiming; Adriana FELIX; Majorri AROYAVE

    2008-01-01

    Isothermal and cyclic oxidation behaviours of pure and yttrium-implanted nickel were studied at 1000℃ in air. Scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM) were used to examine the micro-morphology and structure of oxide scales formed on the nickel substrate. It was found that Y-implantation significantly improved the anti-oxidation ability of nickel in both 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 anti-oxidation of nickel was that Y-implantation greatly reduced the growing speed and grain size of NiO. This fine-grained NiO oxide film might have better high temperature plasticity and could relieve parts of compressive stress by means of creeping, and maintained a ridge character and a relatively low internal stress level. Hence yttrium ion-implantation remarkably enhanced the adhesion of protective NiO oxide scale formed on the nickel substrate.

  8. Cytotoxicity and genotoxicity caused by yttrium oxide nanoparticles in HEK293 cells

    Directory of Open Access Journals (Sweden)

    Selvaraj V

    2014-03-01

    Full Text Available Vellaisamy Selvaraj,1 Sravanthi Bodapati,1 Elizabeth Murray,2 Kevin M Rice,1 Nicole Winston,1,3 Tolou Shokuhfar,4 Yu Zhao,4 Eric Blough1,3,5 1Center for Diagnostic Nanosystems, 2Department of Integrated Science and Technology, 3Department of Pharmaceutical Sciences and Research, School of Pharmacy, Marshall University, Huntington, WV, USA; 4Department of Mechanical Engineering and Engineering Mechanics, Michigan Technological University, Houghton, MI, USA; 5Department of Pharmacology, Physiology and Toxicology, School of Medicine, Marshall University, Huntington, WV, USA Background: The increased use of engineered nanoparticles (NPs has caused new concerns about the potential exposure to biological systems and the potential risk that these materials may pose on human health. Here, we examined the effects of exposure to different concentrations (0–50 µg/mL and incubation times (10 hours, 24 hours, or 48 hours of yttrium oxide (Y2O3 NPs on human embryonic kidney (HEK293 cells. Changes in cellular morphology, cell viability, cell membrane integrity, reactive oxygen species levels, mitochondrial membrane potential, cell death (apoptosis and necrosis, and the DNA damage after NP exposure were compared to the effects seen following incubation with paraquat, a known toxicant. Results: The 24-hour inhibitory concentration 50 (IC50 of Y2O3 NPs (41±5 nm in size in the HEK293 cells was found to be 108 µg/mL. Incubation with Y2O3 NPs (12.25–50 µg/mL increased the ratio of Bax/Bcl-2, caspase-3 expression and promoted apoptotic- and necrotic-mediated cell death in both a concentration and a time-dependent manner. Decreases in cell survivability were associated with elevations in cellular reactive oxygen species levels, increased mitochondrial membrane permeability, and evidence of DNA damage, which were consistent with the possibility that mitochondria impairment may play an important role in the cytotoxic response. Conclusion: These data demonstrate

  9. Combustion Synthesis of Yttrium BARIUM(2) COPPER(3) OXYGEN(6+X) Superconductor.

    Science.gov (United States)

    Lin, Sy-Chyi

    YBa_2Cu_3 O_{rm 6 + x} was produced from copper, barium peroxide, and yttrium oxide by Self-propagating High-temperature Synthesis (SHS) and thermal explosion methods. The SHS process was conducted in two modes: a horizontal combustion and a vertical combustion. The influence of copper particle size on the stability of the reaction front was studied. In contrast to previous studies, a stable reaction front could be maintained even when relatively large copper particles (smaller than 325 mesh) were used. In the horizontal SHS process, large diameter pellets (larger than 22 mm in diameter) enabled stable combustion at room temperature. Elevated ambient temperatures (400 {~} 500^circ C) were needed to stabilize the combustion front movement in small diameter pellets. The product had an average concentration of 84 wt% YBa_2Cu _3O_{rm 6 + x}. In the vertical SHS process, with the aid of a booster, the combustion front moved more rapidly and smoothly than that in the horizontal SHS process and gave a product concentration of about 90 wt% YBa _2Cu_3O_ {rm 6 + x}. High quality product (above 95 wt% YBa_2Cu_3 O_{rm 6 + x}) may be obtained by sintering/calcining the SHS product in an oxygen atmosphere. Three different sintering/calcining processes were studied and the required temperature and the time for each process were determined. The temperature at the center of the pellet in a vertical SHS was measured by thermocouples. The pellet temperature rise is a two step process. The first temperature rise is caused by the oxidation of the copper and the second is caused by the reaction between yttrium oxide and barium cuprate. A reaction mechanism is proposed to explain this behavior. A thermal explosion process was conducted in a continuous rotary kiln. In this mode a pellet was introduced suddenly into a heated rotary kiln causing it to be combusted. After the combustion, the pellet was sintered at 900 to 980 ^circC and a product containing about 95 wt% YBa_2Cu_3 O_{rm 6 + x

  10. Yttrium-90 resin microspheres as an adjunct to sorafenib in patients with unresectable hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Mahvash A

    2016-02-01

    Full Text Available Armeen Mahvash,1 Ravi Murthy,1 Bruno C Odisio,1 Kanwal Pratap Raghav,2 Lauren Girard,2 Sheree Cheung,1 Van Nguyen,3 Joe Ensor,4 Sameer Gadani,5 Khaled M Elsayes,6 Reham Abdel-Wahab,1,7 Manal Hassan,1 Ahmed S Shalaby,1 James C Yao,1 Michael J Wallace,1 Ahmed O Kaseb2 1Department of Interventional Radiology, 2Department of Gastrointestinal Medical Oncology, 3Department of Pharmacy, 4Department of Statistics, The University of Texas MD Anderson Cancer Center, Houston, TX, 5Department of Radiology, Saint Louis University Hospital, St Louis, MO, 6Department of Diagnostic Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; 7Department of Clinical Oncology, Assiut University Hospital, Assiut, Egypt Purpose: The safety and efficacy of the combined use of sorafenib and yttrium-90 resin microspheres (Y90 RMS to treat advanced hepatocellular carcinoma (HCC is not well established. We determined the incidence of adverse events with this combination therapy in patients with advanced HCC at our institution and analyzed the treatment and survival outcomes. Materials and methods: We reviewed the records of 19 patients with Barcelona Clinic Liver Cancer class B or C HCC who underwent treatment with Y90 RMS (for 21 sessions while receiving full or reduced doses of sorafenib between January 2008 and May 2010. Therapy response was evaluated using Response Evaluation Criteria in Solid Tumors. We evaluated median overall survival (OS and progression-free survival (PFS as well as hepatic and extrahepatic disease PFS and incidence of adverse events. Results: The median patient age was 67 years, and portal or hepatic venous invasion was present in eight patients (42%. Ten patients received reduced doses of sorafenib. The median Y90 radiation activity delivered was 41.2 mCi. The partial response of Response Evaluation Criteria in Solid Tumors was observed in four patients (19%. The median hepatic disease PFS was 7.82 months, extrahepatic

  11. Tomographic bremsstrahlung imaging with yttrium-90 in the context of radioembolisation of liver tumors; Tomografische Bildgebung mit Yttrium-90-Bremsstrahlung im Rahmen der Radioembolisation von Lebertumoren

    Energy Technology Data Exchange (ETDEWEB)

    Grosser, Oliver Stephan

    2013-04-12

    Establish tomographic Bremsstrahlung SPECT imaging (BSPECT) for the clinical validation of Selective Internal Radiotherapy (SIRT) with Yttrium-90 ({sup 90}Y) labelled microspheres. Various energy ranges (75 ± 3.8 keV; 135 ± 6.8 keV; 167 ± 8.4 keV) and the summation window were studied to see if they were suitable for BSPECT. To this end, clinically available reconstruction techniques were analysed for their suitability for BSPECT. The tomographic examinations were performed on a cylindrical phantom filled with spheres of different diameters d = [28; 35; 40; 50; 60] mm in a non-active waterfilled background. The spheres were filled with identical {sup 90}Y activity concentration (AC). Measurements were conducted at AC = [14.58; 5.20; 1.98; 0.66] MBq/cm{sup 3}. The BSPECT were reconstructed with filtered back-projection (FBP), a 2D Ordered-Subset Expectation Maximisation Algorithm (2D-OSEM) and a 3D Geometric Mean Algorithm (3D-GMA). Evaluation was made visually and on the basis of objective performance parameters such as contrast, signal-to-noise ratio (SNR) and image noise. While the 75 keV ± 3.8 keV window was identified as suitable for the BSPECT, limitations were revealed as to use of different implementations of the Point Spread Function (PSF). It was found for all reconstruction techniques that, at a given sphere diameter, there existed a linear relationship between the AC in the spheres and the reconstructed pulse rate per volume element. The recovery effect was verified for small spheres. The iterative techniques were found to be suitable for the BSPECT at all AC. At low AC, the 3D-GMA exhibited the least noise and the highest SNR. The FBP turned out to be entirely inappropriate for the BSPECT. The narrow energy window in which the bremsstrahlung interferes with the characteristic X-radiation of lead can be used for BSPECT. In this approach, the tomographic data reconstructed with different algorithms exhibited a varying image quality, with the iterative

  12. Fatigue mechanism of yttrium-doped hafnium oxide ferroelectric thin films fabricated by pulsed laser deposition.

    Science.gov (United States)

    Huang, Fei; Chen, Xing; Liang, Xiao; Qin, Jun; Zhang, Yan; Huang, Taixing; Wang, Zhuo; Peng, Bo; Zhou, Peiheng; Lu, Haipeng; Zhang, Li; Deng, Longjiang; Liu, Ming; Liu, Qi; Tian, He; Bi, Lei

    2017-02-01

    Owing to their prominent stability and CMOS compatibility, HfO2-based ferroelectric films have attracted great attention as promising candidates for ferroelectric random-access memory applications. A major reliability issue for HfO2 based ferroelectric devices is fatigue. So far, there have been a few studies on the fatigue mechanism of this material. Here, we report a systematic study of the fatigue mechanism of yttrium-doped hafnium oxide (HYO) ferroelectric thin films deposited by pulsed laser deposition. The influence of pulse width, pulse amplitude and temperature on the fatigue behavior of HYO during field cycling is studied. The temperature dependent conduction mechanism is characterized after different fatigue cycles. Domain wall pinning caused by carrier injection at shallow defect centers is found to be the major fatigue mechanism of this material. The fatigued device can fully recover to the fatigue-free state after being heated at 90 °C for 30 min, confirming the shallow trap characteristic of the domain wall pinning defects.

  13. Thermalization of magnons in yttrium-iron garnet: nonequilibrium functional renormalization group approach

    Energy Technology Data Exchange (ETDEWEB)

    Hick, Johannes; Rueckriegel, Andreas; Kopietz, Peter [Institut fuer Theoretische Physik, Goethe Universitaet Frankfurt am Main (Germany); Kloss, Thomas [Laboratoire de Physique et Modelisation des Milieux Condense, CNRS and Universite Joseph Fourier, Grenoble (France)

    2013-07-01

    Using a nonequilibrium functional renormalization group (FRG) approach we calculate the time evolution of the momentum distribution of a magnon gas in contact with a thermal phonon bath. As a cutoff for the FRG procedure we use a hybridization parameter Λ giving rise to an artificial damping of the phonons. Within our truncation of the FRG flow equations the time evolution of the magnon distribution is obtained from a rate equation involving cutoff-dependent nonequilibrium self-energies, which in turn satisfy FRG flow equations depending on cutoff-dependent transition rates. Our approach goes beyond the Born collision approximation and takes the feedback of the magnons on the phonons into account. We use our method to calculate the thermalization of a quasi two-dimensional magnon gas in the magnetic insulator yttrium-iron garnet after a highly excited initial state has been generated by an external microwave field. In this material interactions which do not conserve the magnon particle number are present and are considered in our approach.

  14. Synthesis and characterization of yttrium iron garnet (YIG nanoparticles - Microwave material

    Directory of Open Access Journals (Sweden)

    Vinay Sharma

    2017-05-01

    Full Text Available Magnetic Yttrium Iron Garnet (YIG nanoparticles (NPs were prepared by sol–gel (SG and solid-state (SS reaction methods to elucidate the nanoscale size on the magnetic behavior of NPs. It is found that YIG prepared by these two methods are different in many ways. The average NP sizes prepared by SG and SS methods were calculated by Scherrer formula from XRD data. SEM images show the change in grain size for both types of NPs. The sintering temperature required to form pure garnet phase is 750°C for SG and 1000°C for SS NPs. The saturation magnetizations (Ms were 1070 Oe for SG and 1125 Oe for SS NPs, respectively. The coercivity (Hc of SS NPs are twice larger than SG NPs. This is due to the larger crystal sizes of the SS NPs, hence more crystal boundaries. Dynamic properties were studied by ferromagnetic resonance (FMR technique in field-sweep and frequency-sweep mode at different fixed frequencies and at different fixed magnetic fields, respectively. Resonance field (Hr observed to increase linearly with frequency both for SS and SG NPs. The stop-band bandwidth (frequency linewidth is narrower for SG NPs in comparison to SS NPs. Microwave absorption property make this material as a strong candidate for microwave device applications.

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

    Science.gov (United States)

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

    2015-04-01

    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.

  16. Effect of the magnon dispersion on the longitudinal spin Seebeck effect in yttrium iron garnets

    Science.gov (United States)

    Jin, Hyungyu; Boona, Stephen R.; Yang, Zihao; Myers, Roberto C.; Heremans, Joseph P.

    2015-08-01

    We study the temperature dependence of the longitudinal spin Seebeck effect (LSSE) in an yttrium iron garnet Y3F e5O12 (YIG)/Pt system for samples of different thicknesses. In this system, the thermal spin torque is magnon driven. The LSSE signal peaks at a specific temperature that depends on the YIG sample thickness. We also observe freeze-out of the LSSE signal at high magnetic fields, which we attribute to the opening of an energy gap in the magnon dispersion. We observe partial freeze-out of the LSSE signal even at room temperature, where kBT is much larger than the gap. This suggests that a subset of the magnon population with an energy below kBTC (TC˜40 K ) contributes disproportionately to the LSSE; at temperatures above TC, we label these magnons subthermal magnons. The T dependence of the LSSE at temperatures below the maximum is interpreted in terms of an empirical model that ascribes most of the temperature dependence to that of the thermally driven magnon flux, which is related to the details of the magnon dispersion.

  17. Subthermal-magnon-driven longitudinal spin Seebeck effect in yttrium iron garnets (YIG)

    Science.gov (United States)

    Jin, Hyungyu; Boona, Stephen; Yang, Zihao; Myers, Roberto; Heremans, Joseph

    2015-03-01

    Since its discovery in 2008, the spin Seebeck effect (SSE) has intrigued many interesting research all around the world, which has led to the birth of a new field of research, called ``spin-caloritronics''. Of the two different experimental configurations used for detecting SSE, the longitudinal geometry (LSSE) seems to be generally accepted. The yttrium iron garnet (YIG) / Pt bilayer structure has been most commonly used for LSSE experiments because absence of electrons in YIG excludes contaminations from other thermomagnetic effects. The dependence of the LSSE on YIG film thickness and on temperature have been reported, but not yet both together. Here we present experimental data on the temperature dependence of LSSE in Pt/YIG below room temperature in systems in which the thickness of YIG varies. Detailed discussion is given on the experimental results, with emphasis on the role of subthermal-magnons in the temperature dependence of LSSE in the YIG/Pt system. Work supported by the AFOSR-MURI #FA9550-10-1-0533 and the ARO-MURI #W911NF-14-1-0016.

  18. Investigating lanthanide dopant distributions in Yttrium Aluminum Garnet (YAG) using solid state paramagnetic NMR.

    Science.gov (United States)

    McCarty, Ryan J; Stebbins, Jonathan F

    2016-10-01

    This paper demonstrates the approach of using paramagnetic effects observed in NMR spectra to investigate the distribution of lanthanide dopant cations in YAG (yttrium aluminum garnet, Y3Al5O12) optical materials, as a complimentary technique to optical spectroscopy and other standard methods of characterization. We investigate the effects of Ce(3+), Nd(3+), Yb(3+), Tm(3+), and Tm(3+)-Cr(3+) on (27)Al and (89)Y NMR spectra. We note shifted resonances for both AlO4 and AlO6 sites. In some cases, multiple shifted peaks are observable, and some of these can be empirically assigned to dopant cations in known configurations to the observed nuclides. In many cases, AlO6 peaks shifted by more than one magnetic neighbor can be detected. In general, we observe that the measured intensities of shifted resonances, when spinning sidebands are included, are consistent with predictions from models with dopant cations that are randomly distributed throughout the lattice. In at least one set of (27)Al spectra, we identify two sub-peaks possibly resulting from two paramagnetic cations with magnetically coupled spin states neighboring the observed nucleus. We identify systematic changes in the spectra related to known parameters describing the magnetic effects of lanthanide cations, such as larger shift distances when the expectation value of electron spins is greater. We lastly comment on the promise of this technique in future analyses of laser and other crystalline oxide materials. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Yttrium Iron Garnet Thin Films with Very Low Damping Obtained by Recrystallization of Amorphous Material.

    Science.gov (United States)

    Hauser, Christoph; Richter, Tim; Homonnay, Nico; Eisenschmidt, Christian; Qaid, Mohammad; Deniz, Hakan; Hesse, Dietrich; Sawicki, Maciej; Ebbinghaus, Stefan G; Schmidt, Georg

    2016-02-10

    We have investigated recrystallization of amorphous Yttrium Iron Garnet (YIG) by annealing in oxygen atmosphere. Our findings show that well below the melting temperature the material transforms into a fully epitaxial layer with exceptional quality, both structural and magnetic. In ferromagnetic resonance (FMR) ultra low damping and extremely narrow linewidth can be observed. For a 56 nm thick layer a damping constant of α = (6.15 ± 1.50) · 10(-5) is found and the linewidth at 9.6 GHz is as small as 1.30 ± 0.05 Oe which are the lowest values for PLD grown thin films reported so far. Even for a 20 nm thick layer a damping constant of α = (7.35 ± 1.40) · 10(-5) is found which is the lowest value for ultrathin films published so far. The FMR linewidth in this case is 3.49 ± 0.10 Oe at 9.6 GHz. Our results not only present a method of depositing thin film YIG of unprecedented quality but also open up new options for the fabrication of thin film complex oxides or even other crystalline materials.

  20. Microstructural evolution and some mechanical properties of nanosized yttrium oxide dispersion strengthened 13Cr steel

    Science.gov (United States)

    Tich Nguyen, Van; Phuong Doan, Dinh; BaoTrung Tran, Tran; Duong Luong, Van; Nguyen, Van An; Phan, Anh Tu

    2010-09-01

    Oxide dispersion strengthened (ODS) steels, manufactured by a mechanical alloying method, during the past few years, appear to be promising candidates for structural applications in nuclear power plants. The purpose of this work is to elaborate the manufacturing processes of ODS 13Cr steel with the addition of 1.0 wt% yttrium oxide through the powder metallurgy route using the high energy ball mill. Microstructural analysis by scanning electron microscopy (SEM), x-ray diffraction (XRD) and hardness testing have been used to optimize the technological parameters of milling, hot isostatic pressing and heat-treatment processes. The steel hardness increases with decreasing particle size of 13Cr ODS steel. The best hardness was obtained from more than 70 h of milling in the two tanks planetary ball mill or 30 h of milling in the one tank planetary ball mill and hot isostatic pressing at 1150 °C . The particle size of the steel is less than 100 nm, and the density and hardness are about 7.3 g cm-3 and 490 HB, respectively. Report submitted to the 5th International Workshop on Advanced Materials Science and Nanotechnology IWAMSN, Hanoi, 9-12 November 2010.

  1. The use of holmium-yttrium aluminum garnet laser as pit and fissure cleaner

    Directory of Open Access Journals (Sweden)

    Armasastra Bahar

    2009-09-01

    Full Text Available Background: The prevention and management of pit and fissure caries has become relatively more important in recent times. There is a need for an effective preventive measure against pit and fissure caries. Purpose: The purpose of this study was to investigate the effect of laser beam as a cleaning method of pits and fissures. Methods: Ho-YAG laser which has a wavelength of 2.1 µm was used in this experiment. The specimens were extracted human teeth. The effect of three cleaning methods was examined comparatively by scoring the cleaned area of fissure, namely laser irradiation with Ho-YAG laser, chemico-mechanical with combination of 10% NaOCl and ultrasonic scaler and mechanical with ultrasonic scaler. Vertico-bucco-lingual serial ground sections of each tooth were observed under light microscopy. Scoring the depth of cleaned area was performed by comparing the depth of fissure. result: Progressive result was obtained on the cleaning effect of three methods laser irradiation methods which was the most effective compared to other methods but statistically was not significant. Cleaned area of laser irradiation method was 48.91%, chemico-mechanical method was 41.77% and mechanical method was 36.78%. Conclusion: Holmium -yttrium aluminum garner laser is a relatively new method for pit and fissure cleaning even though the effectivity is not yet maximal. More research is needed to maximize the use of this laser.

  2. Investigation of nanostructural, thermal and magnetic properties of yttrium iron garnet synthesized by mechanochemical method

    Energy Technology Data Exchange (ETDEWEB)

    Karami, M.A. [Materials Science and Engineering Department, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Shokrollahi, H., E-mail: shokrollahi@sutech.ac.ir [Electroceramics Group, Materials Science and Engineering Department, Shiraz University of Technology, 71555-313 Shiraz (Iran, Islamic Republic of); Hashemi, B. [Materials Science and Engineering Department, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of)

    2012-09-15

    This paper focuses on the magnetic, structural and thermal properties of mechanically alloyed Y{sub 2}O{sub 3}/{alpha}-Fe{sub 2}O{sub 3} mixed powders and investigates the effects of the mechanical milling and heat treatment on the synthesis of yttrium iron garnet from the primary materials. The morphological and structural studies were carried out by scanning electron microscope and X-ray diffraction, respectively. The thermal activities were measured by differential thermal analysis. The magnetic properties were studied by vibrating sample magnetometer. The results showed that high-energy milling does not lead to the garnet formation and even does not decrease the temperature of the garnet formation. Furthermore, the orthoferrite phase can be achieved slightly during the milling process (up to 96 h) and completely by the heat treatment at lower temperatures (850 Degree-Sign C). - Highlights: Black-Right-Pointing-Pointer The results showed that high energy milling did not lead to the garnet formation. Black-Right-Pointing-Pointer The milling process did not decrease the temperature of the garnet formation. Black-Right-Pointing-Pointer The orthoferrite phase can be achieved slightly during the mechanical milling. Black-Right-Pointing-Pointer The milling process can lower the temperature of orthoferrite formation. Black-Right-Pointing-Pointer The milled powder for 96 h completely transforms to orthoferrite below 700 Degree-Sign C.

  3. Effect of erbium:yttrium-aluminum-garnet laser energies on superficial and deep dentin microhardness.

    Science.gov (United States)

    Chinelatti, Michelle Alexandra; Raucci-Neto, Walter; Corona, Silmara Aparecida Milori; Palma-Dibb, Regina Guenka

    2010-05-01

    This study evaluated the microhardness of superficial and deep dentin irradiated with different erbium:yttrium-aluminum-garnet (Er:YAG) laser energies. Seventy-two molars were bisected and randomly assigned to two groups (superficial dentin or deep dentin) and into six subgroups (160 mJ, 200 mJ, 260 mJ, 300 mJ, 360 mJ, and control). After irradiation, the cavities were longitudinally bisected. Microhardness was measured at six points (20 microm, 40 microm, 60 microm, 80 microm, 100 microm, and 200 microm) under the cavity floor. Data were submitted to analysis of variance (ANOVA) and Fisher's tests (alpha = 0.05). Superficial dentin presented higher microhardness than deep dentin; energy of 160 mJ resulted in the highest microhardness and 360 mJ the lowest one. Values at all points were different, exhibiting increasing microhardness throughout; superficial dentin microhardness was the highest at 20 microm with 160 mJ energy; for deep dentin, microhardness after irradiation at 160 mJ and 200 mJ was similar to that of the control. The lowest energy increased superficial dentin microhardness at the closest extent under the cavity; deep dentin microhardness was not altered by energies of 160 mJ and 200 mJ.

  4. Synthesis and characterization of pyrochlore-type yttrium titanate nanoparticles by modified sol–gel method

    Indian Academy of Sciences (India)

    Z S Chen; W P Gong; T F Chen; S L Li

    2011-06-01

    Pyrochlore-type yttrium titanate (Y2Ti2O7) nanoparticles were successfully synthesized by a simple soft-chemistry technique viz. citric acid sol–gel method (CAM). The preparation process was monitored by X-ray diffraction, thermogravimetric–differential thermal analysis and Fourier transform–infrared experiments and the microstructures and average size of as-prepared products were characterized by transmission electron microscopy and high resolution transmission electron microscopy images. It was found that compared with traditional solid state reaction (SSR), Y2Ti2O7 nanopowders were synthesized at a relatively low temperature (750°C) for shortened reaction time. Detailed analysis showed that the as-prepared Y2Ti2O7 with good dispersibility and narrow size distribution were quasi-spherical; the average size was about 20–30 nm, also, the obtained products had higher BET surface area (50 m2/g). These properties are very helpful for a photocatalyst to achieve excellent activity and may result in better behaviour in hydrogen storage.

  5. 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.

  6. Prediction of yttrium, lanthanum, cerium, and neodymium leaching recovery from apatite concentrate using artificial neural networks

    Institute of Scientific and Technical Information of China (English)

    E. Jorjani; A.H. Bagherieh; Sh. Mesroghli; S. Chehreh Chelgani

    2008-01-01

    The assay and recovery of rare earth elements (REEs) in the leaching process is being determined using expensive analytical methods: inductively coupled plasma atomic emission spectroscopy (ICP-AES) and inductively coupled plasma mass spectroscopy (ICP-MS). A neural network model to predict the effects of operational variables on the lanthanum, cerium, yttrium, and neodymium recovery in the leaching of apatite concentrate is presented in this article. The effects of leaching time (10 to 40 min),pulp densities (30% to 50%), acid concentrations (20% to 60%), and agitation rates (100 to 200 r/min), were investigated and optimized on the recovery of REEs in the laboratory at a leaching temperature of 60οC. The obtained data in the laboratory optimization process were used for training and testing the neural network. The feed-forward artificial neural network with a 4-5-5-1 arrangement was capable of estimating the leaching recovery of REEs. The neural network predicted values were in good agreement with the experimental results. The correlations of R=1 in training stages, and R=0.971, 0.952, 0.985, and 0.98 in testing stages were a result of Ce, Nd, La, and Y recovery prediction respectively, and these values were usually acceptable. It was shown that the proposed neural network model accurately reproduced all the effects of the operation variables, and could be used in the simulation of a leaching plant for REEs.

  7. Colour centres investigation in pure and doped yttrium aluminium garnet epitaxial films

    Science.gov (United States)

    Ubizskii, S. B.; Syvorotka, I. M.; Melnyk, S. S.; Matkovskii, A. O.

    Epitaxial films with thickness of 10-250 μm of yttrium aluminium garnet (YAG) doped with Cr were grown by liquid phase epitaxy technique on YAG: Nd substrateds. Co-doping with Mg2+ was used to force the Cr4+ valent state formation. Dependence of absorption spectra of obtained films on melt-solution composition, growth conditiions and thermal treatment in reducing and oxidizing atmospheres is studied. The absorption being characteristic for YAG:Cr4+ crystals is found in co-doped films grown at higher temperatures (1000-1100°C). The chromium entering in the tetravalent state is confirmed by the annealing experiments. A very intensive absorption band in UV region with maximum at 275 nm was found both in co-doped and YAG: Mg2+ epifilms caused probbly by oxygen vacancies compensating the excess charge of Mg2+. Its intensity correlates with Cr4+ content in the film in the following way: it decreases with Cr4+ entering in the film.

  8. Effective fingerprint recognition technique using doped yttrium aluminate nano phosphor material.

    Science.gov (United States)

    Darshan, G P; Premkumar, H B; Nagabhushana, H; Sharma, S C; Prashanth, S C; Prasad, B Daruka

    2016-02-15

    First time the yttrium aluminate nanoparticles are used to improve the fingerprint quality. Eco-friendly green combustion process is used to synthesize YAlO3:Sm(3+) (0.5-11mol%) nanophosphor using green tea leaf extract as non-toxic and eco-friendly fuel. Powder X-ray diffraction study confirms the orthorhombic phase. The average sizes of the crystallites were found to be in the range 20-35nm. The emission peaks centered at 564, 601 and 647nm is attributed to 4f-4f (4)G5/2→(6)HJ=5/2,7/2,9/2 forbidden transitions of Sm(3+) ions. Judd-Ofelt theory is applied to experimental data for providing qualitative support by determining J-O intensity parameters. The Commission International De I-Eclairage chromaticity co-ordinates are very close to National Television System Committee standard value of white emission (x=0.296, y=0.237). Further, correlated color temperature is found to be ∼11,900K. A simple, fast, highly sensitive and low-cost method for the detection and enhancement of fingermarks in a broad range of surfaces is developed and constitutes an alternative to traditional luminescent powders.

  9. Photocatalytic degradation of methyl orange by polyoxometalates supported on yttrium-doped TiO2

    Institute of Scientific and Technical Information of China (English)

    WANG Yajun; LU Kecheng; FENG Changgen

    2011-01-01

    A series of novel photocatalysts,H3PW12O40-Y-TiO2 nanocomposites with different H3PW12O40 loading levels (10%-40%) were prepared by impregnation method.And the Y-TiO2 support,doped with yttrium,was synthesized via sol-gel technique.The prepared catalysts were characterized by Fourier transform infrared spectroscopy (FT-IR),powder X-ray diffraction (XRD),nitrogen adsorption-desorption analysis and scanning electron microscopy (SEM).The processes allowed obtaining Keggin structure and crystallized anatase with large BET surface area as well as uniform distribution.The effects of H3PW12O40 loadings,catalyst dose,initial pH and concentration of dye solution on the degradation kinetics of methyl orange under UV light (λ≥365 nm) were discussed.Kinetics studies showed that the photocatalytic degradation of methyl orange fitted the apparent first-order reaction.Methyl orange was totally degraded in 21 min under optimum conditions:20% loading,0.03 g dose and pH 1.0.The catalyst was stable and easily to be separated from reaction system for recovery.

  10. Yttrium recovery from primary and secondary sources: a review of main hydrometallurgical processes.

    Science.gov (United States)

    Innocenzi, Valentina; De Michelis, Ida; Kopacek, Bernd; Vegliò, Francesco

    2014-07-01

    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.

  11. 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.

  12. Spatial evolution of multipeaked microwave magnetic envelope solitons in yttrium iron garnet thin films

    Science.gov (United States)

    Wu, Mingzhong; Kraemer, Michael A.; Scott, Mark M.; Patton, Carl E.; Kalinikos, Boris A.

    2004-08-01

    The spatial evolution of multi-peaked microwave magnetic envelope solitons in a thin yttrium iron garnet (YIG) film has been measured and analyzed. The experiments were done on a long and narrow 5-μm -thick single-crystal YIG film strip. Double-peaked and triple-peaked magnetostatic backward volume wave soliton pulses were excited at a nominal carrier frequency of 7.0GHz . The measurements utilized a movable inductive magnetodynamic probe detection system. The formation of these multi-peaked soliton (MPS) pulses is a two step process. First, an initial single large amplitude pulse gradually separates into two or more nonsolitonic peaks. After a certain propagation time, these nonsolitonic peaks evolve, in sequence, into solitonic peaks with constant phase (CP) and an overall stair-like profile. Typically, the larger amplitude peaks lead in time and become solitonic first. As the MPS signals propagate and decay, the peaks lose their CP character in reverse sequence. The region of existence for the “fully formed” MPS pulses for which all the individual peaks have CP character is extremely narrow, typically on the order of a few tenths of a millimeter. The velocities of the individual peaks scale linearly with the peak powers. A nonlinear response analysis of the peak velocity based on the method of envelopes gives a reasonable match to the data.

  13. Thermally induced transparency for short spin wave pulses in yttrium iron garnet (YIG) films

    Science.gov (United States)

    Ordonez Romero, Cesar Leonardo; Kolokoltsev, Oleg; Gomez Arista, Ivan; Qureshi, Naser; Monsiváis Galindo, Guillermo; Vargas Hernández, Hesiquio

    2014-03-01

    The compensation of spin wave propagation losses plays a very important role in the development of novel magnonic devices. Up to now, however, most of the known amplification methods present relative narrow frequency bandwidths due to their resonant nature. In this work, we present compensation of the propagation losses or pseudo-amplification of travelling spin waves by tailoring the bias magnetic field profile. The thermally-induced non-uniform profile of the magnetization introduced on an Yttrium Iron Garnet (YIG) thin film by a localized spot of a cw argon-ion laser creates the conditions to observe the complete compensation of the spin wave propagation losses. The spin wave evolution was mapped with a time and spaced resolved inductive magneto-dynamic prove system. The experiment was carried out using a uniform sample of single-crystal YIG film grown on a gallium-gadolinium garnet (GGG) substrate. The 2mm-wide, 20mm-long and 6microns-thick YIG strip was saturated with an external magnetic field enabling the set up for the propagation of magneto-static surface waves. This work was supported by the UNAM-DGAPA-PAPIIT IA100413.

  14. Synthesis of nanocrystalline yttrium iron garnet by low temperature solid state reaction

    Energy Technology Data Exchange (ETDEWEB)

    Yu Hongtao, E-mail: yuhongtao@swust.edu.cn; Zeng Liwen; Lu Chao; Zhang Wenbo; Xu Guangliang

    2011-04-15

    In this work, nanocrystalline yttrium iron garnet powders were produced by low temperature solid state reaction. The phase evolution during the procedure was determined from the thermogravimetric and differential thermal analysis, and the x-ray diffraction patterns. The results of transmission electron microscopy indicated that the prepared powders exhibited grain size at the nano-level of 20 {approx} 40 nm. Dense ceramics with a theoretical density of around 98% were obtained from the prepared powders after sintering at 1280 deg. C, a relative low sintering temperature compared with conventional ceramic processes, and the saturation magnetizations of sintered samples were also determined. - Research Highlights: {yields}No sol or gel form during the synthesis processing using nitrates and citric acid as raw materials. {yields}The synthesis method needs a low heating temperature (700 deg. C) compared with conventional solid state reaction. {yields}The product is a single phase with homogeneous size distribution and nano grains (20 {approx} 40 nm) confirmed by TEM. {yields}Dense YIG ceramic can be sintered at a low temperature (1280 deg. C) compared with that in conventional processing.

  15. Effect of mischmetal and yttrium on microstructures and mechanical properties of Mg-Al alloy

    Institute of Scientific and Technical Information of China (English)

    张诗昌; 魏伯康; 蔡启舟; 王立世

    2003-01-01

    The effect of yttrium and mischmetal(MMs) on the as-cast and solid solution treated structures of Mg-Al alloys with different Al-contents was investigated. The results show that the MMs in Mg-Al alloy existed in rodAl4 (Ce, La)compound while Y in Mg-Al alloy in polygonal Al2 Y compound. The amount of Mg17 Al12 in Mg-Al al-loy is decreased with increasing Y or MMs addition, and Mg17 Al12 intermetallic compound is changed from continu-ous network to discontinuous one. The Al4 (Ce, La) and Al2 Y compounds are not dissolved into Mg-Al alloy matrixduring solid solution treatment so that their high heat stability can be exhibited. The experiment of mechanical prop-erties indicate that elongation and impact toughness of the Mg-Al-Y alloy with polygonal Al2 Y compound are higherthan those of Mg-Al-MMs alloy with rod Al4 (Ce, La) compound.

  16. Investigation of high-k yttrium copper titanate thin films as alternative gate dielectrics

    Science.gov (United States)

    Grazia Monteduro, Anna; Ameer, Zoobia; Rizzato, Silvia; Martino, Maurizio; Caricato, Anna Paola; Tasco, Vittorianna; Chaitanya Lekshmi, Indira; Hazarika, Abhijit; Choudhury, Debraj; Sarma, D. D.; Maruccio, Giuseppe

    2016-10-01

    Nearly amorphous high-k yttrium copper titanate thin films deposited by laser ablation were investigated in both metal-oxide-semiconductor (MOS) and metal-insulator-metal (MIM) junctions in order to assess the potentialities of this material as a gate oxide. The trend of dielectric parameters with film deposition shows a wide tunability for the dielectric constant and AC conductivity, with a remarkably high dielectric constant value of up to 95 for the thick films and conductivity as low as 6  ×  10-10 S cm-1 for the thin films deposited at high oxygen pressure. The AC conductivity analysis points out a decrease in the conductivity, indicating the formation of a blocking interface layer, probably due to partial oxidation of the thin films during cool-down in an oxygen atmosphere. Topography and surface potential characterizations highlight differences in the thin film microstructure as a function of the deposition conditions; these differences seem to affect their electrical properties.

  17. Composite filling removal with erbium:yttrium-aluminum-garnet laser: morphological analyses.

    Science.gov (United States)

    Correa-Afonso, Alessandra M; Palma-Dibb, Regina G; Pécora, Jesus Djalma

    2010-01-01

    Considering the increase in esthetic restorative materials and need for improvement in unsatisfactory restoration substitution with minimal inadvertent removal of healthy tissues, this study assessed the efficacy of erbium:yttrium-aluminum-garnet (Er:YAG) laser for composite resin removal and the influence of pulse repetition rate on the morphological analyses of the cavity by scanning electron microscope. Composite resin fillings were placed in cavities (1.0 mm deep) prepared in bovine teeth, and the 75 specimens were randomly assigned to five groups according to the technique used for composite filling removal (high-speed diamond bur, group I, as a control, and Er:YAG laser, 250 mJ output energy and 80 J/cm(2) energy density, using different pulse repetition rates: group II, 2 Hz; group III, 4 Hz; group IV, 6 Hz; group V, 10 Hz). After the removal, the specimens were split in the middle, and we analyzed the surrounding and deep walls to check for the presence of restorative material. The estimation was qualitative. The surfaces were examined with a scanning electron microscope. The results revealed that the experimental groups presented bigger amounts of remaining restorative material. The scanning electron microscopy (SEM) analyses showed irregularities of the resultant cavities of the experimental groups that increased proportionally with increase in repetition rate.

  18. Marine phosphorites as potential resources for heavy rare earth elements and yttrium

    Science.gov (United States)

    Hein, James; Koschinsky, Andrea; Mikesell, Mariah; Mizell, Kira; Glenn, Craig R.; Wood, Ray

    2016-01-01

    Marine phosphorites are known to concentrate rare earth elements and yttrium (REY) during early diagenetic formation. Much of the REY data available are decades old and incomplete, and there has not been a systematic study of REY distributions in marine phosphorite deposits that formed over a range of oceanic environments. Consequently, we initiated this study to determine if marine phosphorite deposits found in the global ocean host REY concentrations of high enough grade to be of economic interest. This paper addresses continental-margin (CM) and open-ocean seamount phosphorites. All 75 samples analyzed are composed predominantly of carbonate fluorapatite and minor detrital and authigenic minerals. CM phosphorites have low total REY contents (mean 161 ppm) and high heavy REY (HREY) complements (mean 49%), while seamount phosphorites have 4–6 times higher individual REY contents (except for Ce, which is subequal; mean ΣREY 727 ppm), and very high HREY complements (mean 60%). The predominant causes of higher concentrations and larger HREY complements in seamount phosphorites compared to CM phosphorites are age, changes in seawater REY concentrations over time, water depth of formation, changes in pH and complexing ligands, and differences in organic carbon content in the depositional environments. Potential ore deposits with high HREY complements, like the marine phosphorites analyzed here, could help supply the HREY needed for high-tech and green-tech applications without creating an oversupply of the LREY.

  19. Synthesis and optical characteristics of yttrium-doped zinc oxide nanorod arrays grown by hydrothermal method.

    Science.gov (United States)

    Park, Hyunggil; Kim, Younggyu; Ji, Iksoo; Lee, Sang-Heon; Kim, Jin Soo; Kim, Jin Soo; Leem, Jae-Young

    2014-11-01

    Yttrium-doped ZnO (YZO) nanorods were synthesized by hydrothermal growth on a quartz substrate with various post-annealing temperatures. To investigate the effects of post-annealing on the optical properties and parameters of the nanorods, X-ray diffractometry (XRD), photoluminescence (PL) measurement, and ultraviolet (UV)-visible spectroscopy were used. From the XRD investigation, the full width at half maximum (FWHM) and the dislocation density of the nanorods was found to increase with an increase in the post-annealing temperature. In the PL spectra, the intensity of the near band edge (NBE) emission peak in the UV region also increases with an increase in the temperature of post-annealing. The deep level emission (DLE) peak in the visible region changes with various post-annealing temperatures, and its intensity increases remarkably with post-annealing at 800 degrees C. In this paper, changes in the optical parameters of the nanorods caused by variation in the behavior of Y during post-annealing was investigated, with properties such as absorption coefficients, refractive indices, and dispersion parameters being obtained from transmittance and reflectance analysis.

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

    Science.gov (United States)

    Hien, P. V.; Vu, N. S. H.; Thu, V. T. H.; Somers, A.; Nam, N. D.

    2017-08-01

    Yttrium 4-nitrocinnamate (Y(4-NO2Cin)3) was added to an aqueous chloride solution and studied as a possible corrosion inhibition system. Electrochemical techniques and surface analysis have been powerful tools to better understand the corrosion and inhibition processes of mild steel in 0.01 M NaCl solution. A combination of scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), Potentiodynamic polarization (PD), electrochemical impedance spectroscopy (EIS) and wire beam electrode (WBE) techniques was found to be useful in the characterization of this system. The result indicated that Y(4-NO2Cin)3 is able to effectively inhibit corrosion at a low concentration of 0.45 mM. Surface analysis clearly shows that the surface of steel coupons exposed to Y(4-NO2Cin)3 solution remained uniform and smooth, whereas the surface of steel coupons exposed to solution without inhibitor addition was severely corroded. The results suggest that Y(4-NO2Cin)3 behaves as a mixed inhibitor and mitigates corrosion by promoting random distribution of minor anodes. These are attributed to the formation of metal species bonding to the 4-nitrocinnamate component and hydrolysis of the Y(4-NO2Cin)3 to form oxide/hydroxides as a protective film layer.

  1. Luminescence studies of rare earth doped yttrium gadolinium mixed oxide phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Som, S.; Choubey, A. [Department of Applied Physics, Indian School of Mines, Dhanbad, Jharkhand 826004 (India); Sharma, S.K., E-mail: sksharma_ism@yahoo.co.in [Department of Applied Physics, Indian School of Mines, Dhanbad, Jharkhand 826004 (India)

    2012-09-01

    This paper reports the photoluminescence and thermoluminescence properties of gamma ray induced rare earth doped yttrium gadolinium mixed oxide phosphor. The europium (Eu{sup 3+}) was used as rare earth dopant. The phosphor was prepared by chemical co-precipitation method according to the formula (Y{sub 2-x-y}Gd{sub x}) O{sub 3}: Eu{sub y}{sup 3+} (x=0.5; y=0.05). The photoluminescence emission spectrum of the prepared phosphor shows intense peaks in the red region at 615 nm for {sup 5}D{sub 0}{yields}{sup 7}F{sub 2} transitions and the photoluminescence excitation spectra show a broad band located around 220-270 nm for the emission wavelength fixed at 615 nm. The thermoluminescence studies were carried out after irradiating the phosphor by gamma rays in the dose range from 100 Gy to 1 KGy. In the thermoluminescence glow curves, one single peak was observed at about 300 Degree-Sign C of which the intensity increases linearly in the studied dose range of gamma rays. The glow peak was deconvoluted by GlowFit program and the kinetic parameters associated with the deconvoluted peaks were calculated. The kinetic parameters were also calculated by various glow curve shape and heating rate methods.

  2. Luminescence studies of rare earth doped yttrium gadolinium mixed oxide phosphor

    Science.gov (United States)

    Som, S.; Choubey, A.; Sharma, S. K.

    2012-09-01

    This paper reports the photoluminescence and thermoluminescence properties of gamma ray induced rare earth doped yttrium gadolinium mixed oxide phosphor. The europium (Eu3+) was used as rare earth dopant. The phosphor was prepared by chemical co-precipitation method according to the formula (Y2-x-yGdx) O3: Euy3+ (x=0.5; y=0.05). The photoluminescence emission spectrum of the prepared phosphor shows intense peaks in the red region at 615 nm for 5D0→7F2 transitions and the photoluminescence excitation spectra show a broad band located around 220-270 nm for the emission wavelength fixed at 615 nm. The thermoluminescence studies were carried out after irradiating the phosphor by gamma rays in the dose range from 100 Gy to 1 KGy. In the thermoluminescence glow curves, one single peak was observed at about 300 °C of which the intensity increases linearly in the studied dose range of gamma rays. The glow peak was deconvoluted by GlowFit program and the kinetic parameters associated with the deconvoluted peaks were calculated. The kinetic parameters were also calculated by various glow curve shape and heating rate methods.

  3. Giant Zeeman shifts in the optical transitions of yttrium iron garnet thin films

    Science.gov (United States)

    Vidyasagar, R.; Alves Santos, O.; Holanda, J.; Cunha, R. O.; Machado, F. L. A.; Ribeiro, P. R. T.; Rodrigues, A. R.; Mendes, J. B. S.; Azevedo, A.; Rezende, S. M.

    2016-09-01

    We report the observation of giant Zeeman shifts in the optical transitions of high-quality very thin films of yttrium iron garnet (YIG) grown by rf sputtering on gadolinium gallium garnet substrates. The optical absorption profile measured with magneto-optical absorption spectroscopy shows dual optical transition in the UV-visible frequency region attributed to transitions from the O-2p valence band to the Fe-3d conduction band and from the O-2p valence band to Fe-2p53d6 excitonic states at the Γ-symmetry point of the YIG band structure. The application of a static magnetic field of only 0.6 kOe produces giant Zeeman shifts of ˜100 meV in the YIG band structure and ˜60 meV in the excitonic states corresponding to effective g-factors on the order of 104. The giant Zeeman effects are attributed to changes in energy levels by the large exchange fields of the Fe-3d orbitals during the magnetization process.

  4. Water flow on erbium:yttrium-aluminum-garnet laser irradiation: effects on dental tissues.

    Science.gov (United States)

    Colucci, Vivian; do Amaral, Flávia Lucisano Botelho; Pécora, Jesus Djalma; Palma-Dibb, Regina Guenka; Corona, Silmara Aparecida Milori

    2009-09-01

    Since lasers were introduced in dentistry, there has been considerable advancement in technology. Several wavelengths have been investigated as substitutes for high-speed air turbine. Owing to its high absorbability in water and hydroxyapatite, the erbium:yttrium-aluminum-garnet (Er:YAG) laser has been of great interest among dental practitioners and scientists. In spite of its great potential for hard tissue ablation, Er:YAG laser effectiveness and safety is directly related to an adequate setting of the working patterns. It is assumed that the ablation rate is influenced by certain conditions, such as water content of the target tissue, and laser parameters. It has been shown that Er:YAG irradiation with water coolant attenuates temperature rise and, hence, minimizes the risk of thermally induced pulp injury. It also increases ablation efficiency and enhances adhesion to the lased dental tissue. The aim of this review was to obtain insights into the ablation process and to discuss the effects of water flow on dental tissue ablation using Er:YAG laser.

  5. Structural and spectroscopic analyses of europium doped yttrium oxyfluoride powders prepared by combustion synthesis

    Science.gov (United States)

    Rakov, Nikifor; Guimarães, R. B.; Lozano B., W.; Maciel, Glauco S.

    2013-07-01

    A facile widely spread technique employed to produce low-cost high-yield oxide powders, combustion synthesis, was used to prepare yttrium oxyfluoride crystalline ceramic powders. The structure of the powders was analyzed by X-ray powder diffraction and Rietveld refinement. Samples heat treated at 700 °C had a predominance of vernier orthorhombic Y6O5F8 phase, while samples heat treated at 800 °C crystallized in stoichiometric rhombohedral YOF phase. The samples were doped with luminescent europium trivalent ions (Eu3+) in different concentrations (1-15 wt.%) and Judd-Ofelt theory was used to probe the distortion from the inversion symmetry of the local crystal field and the degree of covalency between the rare-earth ion and the surrounding ligands. The luminescence lifetime was measured and the luminescence quantum efficiency (LQE) was estimated. We observed that Eu3+:Y6O5F8 samples presented higher LQE in spite of the larger local crystal field anisotropy found for Eu3+:YOF samples.

  6. Preparation of Neodymium-Doped Yttrium Aluminum Garnet Transparent Ceramics by Homogeneous Precipitation Method

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Neodymium doped-yttrium aluminum garnet (Nd: YAG) transparent polycrystalline ceramics already become substitutes of single crystals because they are provided with easy fabrication, low cost, large size, highly doped concentration, high heat conductivity, mass fabrication, multi-layers and multi-functions. The Nd: YAG precursor powders with loosely dispersed, slightly agglomerated, super fine and YAG cubic crystal phase were synthesized at 1100 ℃ by the hocal stabilizer, TEOS as sintering additive. The Nd:YAG transparent ceramics were prepared after being vacuum sintered at 1700 ℃ for 5 h. The Nd:YAG ceramic materials were characterized by the TG-DTA, XRD, FT-IR, TEM, FEG-ESEM and FT-PL. The results show that the crystallization temperature of YAG is 850 ℃ and the intermediate crystal phase YAP forming during the heat treatment transforms to YAG cubic crystal phase at 1050 ℃. The lasing wavelength of (Nd0.01Y0.99)3Al5O12 transparent ceramics is 1.065 μm and there exists a slight red-shift compared to the single crystal with the same chemical composition. The optical transmittance is 45% in the visible light and 58% in the near infrared light and the optical transmittance descends with the decreasing the wavelength.

  7. Toxicological effects of rare earth yttrium on wheat seedlings (Triticum aestivum)

    Institute of Scientific and Technical Information of China (English)

    冯秀娟; 朱国才; 李亚宁

    2013-01-01

    This study examined the biochemical responses of wheat (Triticum aestivum) to the stress of rare earth yttrium (Y) and showed that 25-100 mg/kg Y treatments evidently increased the biomass (root mass, shoot mass and leaf mass), accompanied by a significant (p<0.05) increase in the chlorophyll (CHL) content in wheat leaves. Increased malondialdehyde (MDA) levels were de-tected in wheat shoots (stem and leaf) and roots too, indicating the presence of poisoning active oxygen species (AOS). The MDA content in wheat roots increased with the augmentation of Y concentration. These results indicated that there was a dose-dependent effect of Y on the changes of MDA content in wheat roots. Although the activities of superoxide dismutases (SOD), peroxidases (POD) and catalases (CAT) in wheat shoots and roots irregularly fluctuated with the increase in Y concentration, 25-100 mg/kg Y significantly (p<0.01) increased the activities of SOD and POD. In general, the dose-dependent effects of Y on the activity of anti-oxidant enzymes were insignificant. Our data also indicated that the increase in SOD and POD activities could be used as a good bio-marker for the stress induced by low concentrations of Y.

  8. Yttrium-90 Radioembolization for Colorectal Cancer Liver Metastases: A Single Institution Experience

    Directory of Open Access Journals (Sweden)

    Gary W. Nace

    2011-01-01

    Full Text Available Purpose. We sought to evaluate our experience using yttrium-90 (90Y resin microsphere hepatic radioembolization as salvage therapy for liver-dominant metastatic colorectal cancer (mCRC. Methods. A retrospective review of consecutive patients with unresectable mCRC who were treated with 90Y after failing first and second line systemic chemotherapy. Demographics, treatment dose, biochemical and radiographic response, toxicities, and survival were examined. Results. Fifty-one patients underwent 90Y treatments of which 69% were male. All patients had previously undergone extensive chemotherapy, 31% had undergone previous liver-directed therapy and 24% had a prior liver resection. Using RECIST criteria, either stable disease or a partial response was seen in 77% of patients. Overall median survival from the time of first 90Y treatment was 10.2 months (95% CI = 7.5–13.0. The absence of extrahepatic disease at the time of treatment with 90Y was associated with an improved survival, median survival of 17.0 months (95% CI = 6.4–27.6, compared to those with extrahepatic disease at the time of treatment with 90Y, 6.7 months (95% CI = 2.7–10.6 Conclusion: 90Y therapy is a safe locoregional therapy that provides an important therapeutic option to patients who have failed first and second line chemotherapy and have adequate liver function and performance status.

  9. Yttrium-90 radioembolization for the treatment of unresectable liver cancer: Results of a single center

    Directory of Open Access Journals (Sweden)

    Özhan Özgür

    2014-03-01

    Full Text Available Objective: To determine the effects of yttrium-90 (Y-90 resin microsphere radioembolization therapy on patients with unresectable liver cancer who do not benefit from chemotherapy. Methods: Fifty-five patients underwent radioembolization therapy included in the study whose had unresectable primary or metastatic liver cancer originating from the gastrointestinal tract. Three were excluded from the study after pre-evaluation angiography. Thirteen (23.6% of the remaining 52 patients had hepatocellular carcinoma and 39 (76.4% had metastatic liver cancer. Fifty-two patients underwent Y-90 radioembolization treatment. Each patient's response to the administered treatment was evaluated using the Response Evaluation Criteria in Solid Tumors (RECIST and the overall probability of survival was displayed graphically by the Kaplan-Meier method. Results: After Y-90 therapy, 47 patients were follow-up. While 57% of the patients responded to treatment as clinical benefit, the disease progressed in 43%. The median hepatic progression-free survival time of the patients was 3.4 months (95% confidence interval (ci:1.4-5.3 and the overall survival time was 11.3 months (95%, CI:8.7-14.03. Conclusion: This study emphasizes that Y-90 resin microsphere radioembolization treatment is effective in patients with unresectable liver cancer.

  10. Characterization of Erbium Substituted Yttrium Iron Garnet Films Prepared by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Ramadan E. Shaiboub

    2014-01-01

    Full Text Available Yttrium iron garnet (YIG thin films substituted erbium ions (Er+3 Er0.4Y2.6Fe5O12 films were prepared by a sol-gel method at different temperatures which varied from 800 to 1000°C for 2 hours in air. Magnetic and microstructural properties of the films were characterized with X-ray diffraction (XRD, the field emission scanning electron microscopy (FESEM, and vibrating sample magnetometer (VSM. The XRD patterns of the sample have only peaks of the garnet structure. The lattice constants decrease, while the particle size increases from 51 to 85 nm as the annealing temperature increases with average in thickness of 300 nm. The saturation magnetization and the coercivity of the samples increased from 26 (emu/cc and 28 Oe for the film annealed at 800°C to 76 (emu/cc and 45 Oe for film annealed at 1000°C, respectively.

  11. Patient Selection and Activity Planning Guide for Selective Internal Radiotherapy With Yttrium-90 Resin Microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Wan-Yee, E-mail: josephlau@surgery.cuhk.edu.hk [Faculty of Medicine, Chinese University of Hong Kong, Shatin, New Territories (Hong Kong); Kennedy, Andrew S. [Wake Radiology Oncology, Cary, NC (United States); Department of Biomedical Engineering, North Carolina State University, Raleigh, NC (United States); Kim, Yun Hwan [Department of Radiology, Anam Hospital, Korea University College of Medicine, Seoul (Korea, Republic of); Lai, Hee Kit [Nuclear Medicine and PET Centre, Mount Elizabeth Hospital, Singapore (Singapore); Lee, Rheun-Chuan [Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan (China); Leung, Thomas W.T. [Comprehensive Oncology Centre, Hong Kong Sanatorium and Hospital (Hong Kong); Liu, Ching-Sheng [Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei, Taiwan (China); Salem, Riad [Division of Interventional Radiology, Northwestern University, Chicago, IL (United States); Sangro, Bruno [Liver Unit, Clinica Universitaria de Navarra and Centro de Investigacion Biomedica en Red de Enfermedades Hepaticas y Digestivas, Pamplona (Spain); Shuter, Borys [Department of Diagnostic Imaging, National University Hospital, Singapore (Singapore); Wang, Shih-Chang [Parker-Hughes Professor of Diagnostic Radiology, University of Sydney, Sydney, NSW (Australia)

    2012-01-01

    Purpose: Selective internal radiotherapy (SIRT) with yttrium-90 ({sup 90}Y) resin microspheres can improve the clinical outcomes for selected patients with inoperable liver cancer. This technique involves intra-arterial delivery of {beta}-emitting microspheres into hepatocellular carcinomas or liver metastases while sparing uninvolved structures. Its unique mode of action, including both {sup 90}Y brachytherapy and embolization of neoplastic microvasculature, necessitates activity planning methods specific to SIRT. Methods and Materials: A panel of clinicians experienced in {sup 90}Y resin microsphere SIRT was convened to integrate clinical experience with the published data to propose an activity planning pathway for radioembolization. Results: Accurate planning is essential to minimize potentially fatal sequelae such as radiation-induced liver disease while delivering tumoricidal {sup 90}Y activity. Planning methods have included empiric dosing according to degree of tumor involvement, empiric dosing adjusted for the body surface area, and partition model calculations using Medical Internal Radiation Dose principles. It has been recommended that at least two of these methods be compared when calculating the microsphere activity for each patient. Conclusions: Many factors inform {sup 90}Y resin microsphere SIRT activity planning, including the therapeutic intent, tissue and vasculature imaging, tumor and uninvolved liver characteristics, previous therapies, and localization of the microsphere infusion. The influence of each of these factors has been discussed.

  12. Yttrium-90 microsphere radioembolization for the treatment of liver malignancies: a structured meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vente, M.A.D.; Wondergem, M.; Bosch, M.A.A.J. van den; Lam, M.G.E.H.; Schip, A.D. van het; Nijsen, J.F.W. [University Medical Center Utrecht, Department of Radiology and Nuclear Medicine, Utrecht (Netherlands); Tweel, I. van der [Utrecht University, Centre for Biostatistics, Utrecht (Netherlands); Zonnenberg, B.A. [University Medical Center Utrecht, Department of Internal Medicine, Utrecht (Netherlands)

    2009-04-15

    Radioembolization with yttrium-90 microspheres ({sup 90}Y-RE), either glass- or resin-based, is increasingly applied in patients with unresectable liver malignancies. Clinical results are promising but overall response and survival are not yet known. Therefore a meta-analysis on tumor response and survival in patients who underwent {sup 90}Y-RE was conducted. Based on an extensive literature search, six groups were formed. Determinants were cancer type, microsphere type, chemotherapy protocol used, and stage (deployment in first-line or as salvage therapy). For colorectal liver metastases (mCRC), in a salvage setting, response was 79% for {sup 90}Y-RE combined with 5-fluorouracil/leucovorin (5-FU/LV), and 79% when combined with 5-FU/LV/oxaliplatin or 5-FU/LV/irinotecan, and in a first-line setting 91% and 91%, respectively. For hepatocellular carcinoma (HCC), response was 89% for resin microspheres and 78% for glass microspheres. No statistical method is available to assess median survival based on data presented in the literature. In mCRC, {sup 90}Y-RE delivers high response rates, especially if used neoadjuvant to chemotherapy. In HCC, {sup 90}Y-RE with resin microspheres is significantly more effective than {sup 90}Y-RE with glass microspheres. The impact on survival will become known only when the results of phase III studies are published. (orig.)

  13. Marine Phosphorites as Potential Resources for Heavy Rare Earth Elements and Yttrium

    Directory of Open Access Journals (Sweden)

    James R. Hein

    2016-08-01

    Full Text Available Marine phosphorites are known to concentrate rare earth elements and yttrium (REY during early diagenetic formation. Much of the REY data available are decades old and incomplete, and there has not been a systematic study of REY distributions in marine phosphorite deposits that formed over a range of oceanic environments. Consequently, we initiated this study to determine if marine phosphorite deposits found in the global ocean host REY concentrations of high enough grade to be of economic interest. This paper addresses continental-margin (CM and open-ocean seamount phosphorites. All 75 samples analyzed are composed predominantly of carbonate fluorapatite and minor detrital and authigenic minerals. CM phosphorites have low total REY contents (mean 161 ppm and high heavy REY (HREY complements (mean 49%, while seamount phosphorites have 4–6 times higher individual REY contents (except for Ce, which is subequal; mean ΣREY 727 ppm, and very high HREY complements (mean 60%. The predominant causes of higher concentrations and larger HREY complements in seamount phosphorites compared to CM phosphorites are age, changes in seawater REY concentrations over time, water depth of formation, changes in pH and complexing ligands, and differences in organic carbon content in the depositional environments. Potential ore deposits with high HREY complements, like the marine phosphorites analyzed here, could help supply the HREY needed for high-tech and green-tech applications without creating an oversupply of the LREY.

  14. Crystallization and deuterium permeation behaviors of yttrium oxide coating prepared by metal organic decomposition

    Directory of Open Access Journals (Sweden)

    Takumi Chikada

    2016-12-01

    Full Text Available Yttrium oxide coatings were fabricated on reduced activation ferritic/martensitic steels by metal organic decomposition with a dip-coating technique, and their deuterium permeation behaviors were investigated. The microstructure of the coatings varied with heat-treatment temperature: amorphous at 670ºC (amorphous coating and crystallized at 700ºC (crystallized coating. Deuterium permeation flux of the amorphous coating was lower than the uncoated steel by a factor of 5 at 500ºC, while that of the crystallized coating was lower by a factor of around 100 at 400‒550ºC. The permeation fluxes of both coatings were drastically decreased during the measurements at higher temperatures by a factor of up to 790 for the amorphous coating and 1000 for the crystallized one, indicating a microstructure modification occurred by an effect of test temperature with hydrogen flux. Temperature dependence of deuterium diffusivity in the coatings suggests that the decrease of the permeation flux has been derived from a decrease of the diffusivity. Characteristic permeation behaviors were observed with different annealing conditions; however, they can be interpreted using the permeation mechanism clarified in the previous erbium oxide coating studies.

  15. Thermographic measurements of the spin Peltier effect in metal/yttrium-iron-garnet junction systems

    Science.gov (United States)

    Daimon, Shunsuke; Uchida, Ken-ichi; Iguchi, Ryo; Hioki, Tomosato; Saitoh, Eiji

    2017-07-01

    The spin Peltier effect (SPE), heat-current generation due to spin-current injection, in various metal (Pt, W, and Au single layers and Pt/Cu bilayer)/ferrimagnetic insulator [yttrium-iron-garnet (YIG)] junction systems has been investigated by means of a lock-in thermography (LIT) method. The SPE is excited by a spin current across the metal/YIG interface, which is generated by applying a charge current to the metallic layer via the spin Hall effect. The LIT method enables the thermal imaging of the SPE free from the Joule-heating contribution. Importantly, we observed spin-current-induced temperature modulation not only in the Pt/YIG and W/YIG systems, but also in the Au/YIG and Pt/Cu/YIG systems, excluding the possible contamination by anomalous Ettingshausen effects due to proximity-induced ferromagnetism near the metal/YIG interface. As demonstrated in our previous study, the SPE signals are confined only in the vicinity of the metal/YIG interface; we buttress this conclusion by reducing a spatial blur due to thermal diffusion in an infrared-emission layer on the sample surface used for the LIT measurements. We also found that the YIG-thickness dependence of the SPE is similar to that of the spin Seebeck effect measured in the same Pt/YIG sample, implying the reciprocal relation between them.

  16. Structural and spectroscopic analyses of europium doped yttrium oxyfluoride powders prepared by combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Rakov, Nikifor [PG-Ciência dos Materiais, Universidade Federal do Vale do São Francisco, 48902-300 Juazeiro, BA (Brazil); Guimarães, R. B.; Maciel, Glauco S. [Instituto de Física, Universidade Federal Fluminense, 24210-346 Niterói, RJ (Brazil); Lozano B, W. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil)

    2013-07-28

    A facile widely spread technique employed to produce low-cost high-yield oxide powders, combustion synthesis, was used to prepare yttrium oxyfluoride crystalline ceramic powders. The structure of the powders was analyzed by X-ray powder diffraction and Rietveld refinement. Samples heat treated at 700 °C had a predominance of vernier orthorhombic Y{sub 6}O{sub 5}F{sub 8} phase, while samples heat treated at 800 °C crystallized in stoichiometric rhombohedral YOF phase. The samples were doped with luminescent europium trivalent ions (Eu{sup 3+}) in different concentrations (1–15 wt.%) and Judd-Ofelt theory was used to probe the distortion from the inversion symmetry of the local crystal field and the degree of covalency between the rare-earth ion and the surrounding ligands. The luminescence lifetime was measured and the luminescence quantum efficiency (LQE) was estimated. We observed that Eu{sup 3+}:Y{sub 6}O{sub 5}F{sub 8} samples presented higher LQE in spite of the larger local crystal field anisotropy found for Eu{sup 3+}:YOF samples.

  17. Research on cathode material of Li-ion battery by yttrium doping

    Institute of Scientific and Technical Information of China (English)

    TIAN Yanwen; KANG Xiaoxue; LIU Liying; XU Chaqing; QU Tao

    2008-01-01

    Modification of LiFePO4, LiMn2O4 and Li1+xV3O8 by doping yttrium was investigated. The influences of doping Y on structure, morphology and electrochemical performance of cathode materials were investigated systematically. The results indicated that the mechanisms of Y doping in three cathode materials were different, so the influences on the material performance were different. The crystal structure of the three materials was not changed by Y doping. However, the crystal parameters were influenced. The crystal parameters of LiMn2O4 became smaller, and the interlayer distance of (100) crystal plane of Li1+xV3O8 was lengthened after Y doping. The grain size of Y-doped LiFePO4 became smaller and grain morphology became more regular than that of undoped LiFePO4. It indicated that Y doping had no influence on crystal particle and morphology of LiMn2O4. The morphology of Li1+xV3O8 became irregular and its size became larger with the increase of Y. For LiFePO4 and Li1+xV3O8, both the initial discharge capacities and the cyclic performance were improved by Y doping. For LiMn2O4, the cyclic performance became better and the initial discharge capacities declined with increasing Y doping.

  18. Laser refrigeration of rare-earth doped sodium-yttrium-fluoride nanowires

    Science.gov (United States)

    Zhou, Xuezhe; Roder, Paden B.; Smith, Bennett E.; Pauzauskie, Peter J.

    2017-02-01

    Hexagonal sodium yttrium fluoride (β-NaYF4) crystals are currently being studied for a wide range of applications including color displays, solar cells, photocatalysis, and bio-imagβing. β-NaYF4 has also been predicted to be a promising host material for laser refrigeration of solids. However, due to challenges with growing Czochralski β- NaYF4 single-crystals, laser refrigeration of bulk β-NaYF4 has not yet been achieved6. Recently hydrothermal processing has been reported to produce Yb-doped β-NaYF4 nanowires (NWs) that undergo laser refrigeration during single-beam optical trapping experiments in heavy water. The local refrigeration of the individual nanowire is quantified through the analysis of its Brownian motion through the analysis of forward scattered light that is focused onto a quadrant photodiode. The individual β-NaYF4 nanowires show maximum local cooling of 9°C below ambient conditions. Here we present the emission lifetime for the 4S3/2 - 4I15/2 transition for Er(III) ions in Yb/Er-codoped -NaYF4 NW ensembles was measured to be (220 +/- 6) μs using a an electron multiplying charge coupled device (EMCCD) as a detector with high spatial resolution. This lifetime is consistent with values reported in the literature.

  19. Identification and Plasma Diagnostics Study of Extreme Ultraviolet Transitions in Highly Charged Yttrium

    Directory of Open Access Journals (Sweden)

    Roshani Silwal

    2017-09-01

    Full Text Available Extreme ultraviolet spectra of the L-shell ions of highly charged yttrium (Y 26 + –Y 36 + were observed in the electron beam ion trap of the National Institute of Standards and Technology using a flat-field grazing-incidence spectrometer in the wavelength range of 4 nm-20 nm. The electron beam energy was systematically varied from 2.3 keV–6.0 keV to selectively produce different ionization stages. Fifty-nine spectral lines corresponding to Δ n = 0 transitions within the n = 2 and n = 3 shells have been identified using detailed collisional-radiative (CR modeling of the non-Maxwellian plasma. The uncertainties of the wavelength determinations ranged between 0.0004 nm and 0.0020 nm. Li-like resonance lines, 2s– 2 p 1 / 2 and 2s–2 p 3 / 2 , and the Na-like D lines, 3s– 3 p 1 / 2 and 3s– 3 p 3 / 2 , have been measured and compared with previous measurements and calculations. Forbidden magnetic dipole (M1 transitions were identified and analyzed for their potential applicability in plasma diagnostics using large-scale CR calculations including approximately 1.5 million transitions. Several line ratios were found to show strong dependence on electron density and, hence, may be implemented in the diagnostics of hot plasmas, in particular in fusion devices.

  20. Non-local thermal spin injection to study spin diffusion in yttrium iron garnet

    Science.gov (United States)

    Giles, Brandon; Yang, Zihao; Jamison, John; Myers, Roberto

    Understanding the generation, detection, and manipulation of spin current is critical for the development of devices that depend on spin transport for information processing and storage. Recent studies have shown that spin transport over long distances is possible in the magnetic insulator yttrium iron garnet (YIG) through the diffusion of non-equilibrium magnons. Electrically excited magnons have been shown to diffuse up to 40um at room temperature, while thermally injected magnons were detected at ranges greater than 125um at 23K. However, much work is still required to fully understand the processes responsible for magnon diffusion. Here, we present an in-depth study of the diffusion of magnons in YIG. By using the non-local thermal spin detection method, we analyze spin transport as a function of temperature. Spin diffusion maps, which can be used to experimentally determine the spin diffusion length in YIG as a function of temperature, are presented Work supported by the Army Research Office MURI W911NF-14-1-0016.

  1. Precision mass measurements of neutron-rich yttrium and niobium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Hager, U. [Department of Physics, University of Jyvaeskylae, PO Box 35 (YFL), FIN-40014 (Finland)], E-mail: ulrike.hager@phys.jyu.fi; Jokinen, A.; Elomaa, V.-V.; Eronen, T.; Hakala, J.; Kankainen, A.; Rahaman, S.; Rissanen, J.; Moore, I.D.; Rinta-Antila, S.; Saastamoinen, A.; Sonoda, T.; Aystoe, J. [Department of Physics, University of Jyvaeskylae, PO Box 35 (YFL), FIN-40014 (Finland)

    2007-09-01

    The atomic masses of neutron-rich {sup 95-101}Y and {sup 101-107}Nb produced in proton-induced fission of uranium were determined using the JYFLTRAP double Penning trap setup. Accuracies of better than 10 keV could be reached for most nuclides. The masses of {sup 106,107}Nb were measured for the first time. The energies of the isomeric states in {sup 96}Y and {sup 100}Y were measured as 1541(10) keV and 145(15) keV. The niobium isotopes appear to be systematically less bound than the values given in the latest Atomic Mass Evaluation. The new data lie in a region of the nuclear chart characterised by the transition from spherical to strongly deformed shapes. These structural changes are explored by studying different systematic trends. The data are also compared to several model predictions to test their ability to reproduce the structural changes along the isotopic chains of yttrium and niobium.

  2. X-ray analysis of the actual structure of yttrium orthoborate YBO3

    Science.gov (United States)

    Shmyt'ko, I. M.; Ganeeva, G. R.

    2016-12-01

    Detailed X-ray analysis of variations in the structure of yttrium orthoborate in the process of successive high-temperature isothermal anneals of an originally amorphous precursor state is performed. It is established that the diffraction reflex intensity distribution of YBO3 measured at room temperature, obtained in the initial stages of crystallization, corresponds to the known low-temperature vaterite phase with the space group (sp. gr.) P63/ m and, after a series of high-temperature anneals, it transforms into a distribution known for the vaterite modification with the sp. gr. P63/ mmc and the same lattice parameters. This result is explained on the basis of the sphericity of X-ray waves and is connected with the transformation of the crystallites from a spherical shape upon low-temperature anneals to a dumbbell shape upon high-temperature anneals. As a result of in situ experiments conducted at 1250°C, it was established that the initial low-temperature hexagonal vaterite cell transforms above 1000°C into a monoclinic cell.

  3. Epitaxial and non-epitaxial platinum, palladium and silver films on yttrium-stabilised zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Gesa, E-mail: gesa.beck@physik.uni-augsburg.de [Institute of Physics, University Augsburg, Universitaetsstrasse 1a, 86159 Augsburg (Germany); Bachmann, Christoph [Institute of Physical Chemistry, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 58, 35392 Giessen (Germany); Bretzler, Rita [Research Institute Precious Metals & Metals Chemistry, Katharinenstrasse 17, 73525 Schwaebisch Gmuend (Germany); Kmeth, Ralf [Institute of Physics, University Augsburg, Universitaetsstrasse 1a, 86159 Augsburg (Germany)

    2015-05-05

    Platinum, palladium and silver films have been prepared on differently orientated YSZ (yttrium-stabilised zirconia) substrates by PLD (pulsed laser deposition). The deposition temperatures for platinum were 200 °C and 400 °C, whereas palladium and silver were deposited only at 200 °C. The microstructure of the films depends on the particular metal, on the orientation of the substrate and on the deposition temperature. Platinum – deposited at 400 °C – forms single crystalline, epitaxial (111), (311) and (110) orientated as well as (111) orientated polycrystalline films. Platinum, palladium and silver – deposited at 200 °C – always form (111) orientated and polycrystalline films, in some cases also with a fraction of epitaxial grown grains. The formed microstructures were discussed on the basis of interface and surface energy minimization and structure zone models. - Highlights: • Pt, Pd and Ag films are prepared on differently orientated YSZ. • Substrate orientation and deposition temperature influences the microstructure. • Pt forms epitaxial and polycrystalline films. • Pd and Ag form polycrystalline films, sometimes with epitaxial grown grains. • The formed microstructures are described by energy minimization.

  4. Synthesis and Characterization of A Polynuclear Yttrium Trifluoroethoxide and Its Activity for Oligomerization of Phenyl Isocyanate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A polynuclear yttrium trifluoroethoxide was synthesized and its activity for the oligomerization of phenyl isocyanate was tested. Reaction of anhydrous YCl3 with CF3CH2ONa in a 1:3 molar ratio in THF at room temperature, after workup, gave complex 1 as colorless crystals. The composition of complex 1 is [Y(OCH2CF3)3]6ONa2(THF)12, which was identified by elemental analysis and 1H NMR. Further X-ray structure determination reveals that complex 1 is a polynuclear ion pair compound, [Y6(μ6-O)(OCH2CF3)18]2-[Na(THF)6]+2 (1). The crystal data of complex 1 are trigonal, P-3 space group, a=1.78440(14) nm, b=1.78440(14) nm, c=1.27395(12) nm, γ=120°, V=3.5129(5) nm3, Z=1, Dc=1.607 mg·m-3, μ=2.591 mm-1 (Mo Kα), F(000)=1710, R=0.067, wR=0.182. Preliminary results demonstrated that complex 1 is a highly effective catalyst for the oligomerization of phenyl isocyanate.

  5. Effect of Low Concentration of Yttrium on Physiological Characteristics of Cucumber (Cucumis Sativus L.)

    Institute of Scientific and Technical Information of China (English)

    Wang Shuo; Chen Dan; Qin Zhaojiang; Dong Zhenyu; Ju Mingchao; Xie Bingning

    2007-01-01

    There is no doubt that rare earth elements stand an important position among the essential elements of plant growth and it is long time since they are first used as plant growth promoters. Given their effects on microstructure, most reports are focused on the toxicology rather than promotion. Using cucumis sativus L. (Jin Chun No.5) as experiment material, we try to find out the nutritional effects of low Y3+ concentrations on cucumber seedlings' leaves. The present paper suggests that the rare earth elements act as micronutrients at low concentrations while they give rise to toxicity at high concentration. Benefits defeat toxicity with concentration ranging from 5 to 25μmol·L-1. Through careful study, at the Y (N03)3 concentration of 10μmol·L1 the content of chlorophyll as well as the activities of SOD, Cu-Zn SOD and the POD are the highest. It indicates 10μmol·L-1 is the optimum concentration of yttrium for promoting the cucumber growth.

  6. Induced magnetism in exfoliated graphene via proximity effect with yttrium iron garnet thin films

    Science.gov (United States)

    Amado, Mario; Li, Yang; di Bernardo, Angelo; Lombardo, Antonio; Ferrari, Andrea C.; Robinson, Jason

    The recent discovery of the quantum anomalous Hall effect (QAHE) in magnetically doped topological insulators cooled below in the milikelvin regime represents breakthrough in the field of spintronics. Theoretically, the QAHE should occur in graphene proximity coupled to a ferromagnetic insulato but with the promise of much higher operating temperatures for practical applications. Hints of proximity-induced magnetism in graphene coupled to yttrium iron garnet (YIG) films have been reported although the QAHE remains unobserved; the lack of a fully developed plateau in graphene/YIG devices can be attributed to poor interfacial coupling and therefore a dramatically reduced magnetic proximity effect. Here we report the deposition and characterisation of epitaxial thin-films of YIG on lattice-matched gadolinium gallium garnet substrates by pulsed laser deposition. Pristine exfoliated graphene flakes transferred mechanically onto the YIG are reported alongside results that correlate the effects of YIG morphology on the electronic and crystal properties of graphene by electrical (low temperature magnetoresistance measurements in Hall-bar-like configuration) and optical (Raman) means.

  7. Geochemistry of rare earth elements and yttrium in a Ge-poor coal from the Wulantuga ore deposit, Inner Mongolia, North China

    Institute of Scientific and Technical Information of China (English)

    Jingjing Liu; Yaofa Jiang; Panpan Xie; Qingqian Li

    2014-01-01

    This paper reports data of yttrium and rare earth (REY, or REE if Y is considered) in a Ge-poor (the average value of Ge is 0.57μg/g) coal from the Wulantuga ore deposit, middle Inner Mongolia, northern China. The contents of yttrium and rare earth in six coal samples of the Wulantuga ore deposit were detected by inductively coupled plasma mass spectrometry. The content of yttrium and rare earth in the study area varies from 5.88 to 119.19μg/g, with an average of 61.85μg/g, similar to the average value for world coals. The light-REY and heavy-REY enrichments are the two major REY-enrichment types of the Ge-poor coal from the Wulantuga ore deposit, and the top and bottom parts of the coal seam have a higher content of REY than the middle part. The sources of yttrium and rare earth in the Ge-poor coal of Wulantuga may be mainly associated with terrigenous materials and natural waters enriched in yttrium and rare earth.

  8. Neodymium:Yttrium aluminum garnet laser in the management of oral leukoplakia: A case series

    Directory of Open Access Journals (Sweden)

    Somdipto Das

    2015-01-01

    Full Text Available Objectives: Oral leukoplakia is a nonscrappable whitish patch described as a potentially malignant disorder with high prevalence in India. Besides medicinal treatment, neodymium: Yttrium aluminum garnet (Nd: YAG laser is also used for the management of oral leukoplakia. This study evaluated the role of Nd: YAG laser in the management of oral leukoplakia and also investigated postoperative complications along with long-term prognosis of the disease. Settings and Designs: The study is a prospective cohort study conducted for 24 months (June 2011 to May 2013 in Lucknow. Materials and Methods: The study comprised of 42 patients, both male and female of Indian origin and diagnosed with oral leukoplakic lesions. Patients with biopsy proven squamous cell carcinoma and medically compromised are excluded from the study. All patients has undergone ablation of lesion by pulsed Nd: YAG laser and were followed after 24 h, 72 h, 1-week and then successively for 1, 3, 6 months and then 1 st and 2 nd postoperative years. Results: Pain and slough were evaluated by Wicoxon rank test (P = 0.0001 statistically significant which decreased from 24 h to 1-week and became nil in subsequent follow-ups. Similarly, McNemar′s test (P = 0.001 statistically significant was used for evaluation of burning sensation, paresthesia, infection and recurrences. Recurrence was noted in 2 patients but following the second application, there were no recurrences over the period of further follow-up. None of the patient suffered from an infection, paresthesia or anesthesia. Conclusion: Hence, Nd: YAG laser was found to be effective in ablating leukoplakia. It is convenient, economical with minimum complications and morbidities.

  9. Swift heavy ion-beam induced amorphization and recrystallization of yttrium iron garnet.

    Science.gov (United States)

    Costantini, Jean-Marc; Miro, Sandrine; Beuneu, François; Toulemonde, Marcel

    2015-12-16

    Pure and (Ca and Si)-substituted yttrium iron garnet (Y3Fe5O12 or YIG) epitaxial layers and amorphous films on gadolinium gallium garnet (Gd3Ga5O12, or GGG) single crystal substrates were irradiated by 50 MeV (32)Si and 50 MeV (or 60 MeV) (63)Cu ions for electronic stopping powers larger than the threshold value (~4 MeV μm(-1)) for amorphous track formation in YIG crystals. Conductivity data of crystalline samples in a broad ion fluence range (10(11)-10(16) cm(-2)) are modeled with a set of rate equations corresponding to the amorphization and recrystallization induced in ion tracks by electronic excitations. The data for amorphous layers confirm that a recrystallization process takes place above ~10(14) cm(-2). Cross sections for both processes deduced from this analysis are discussed in comparison to previous determinations with reference to the inelastic thermal-spike model of track formation. Micro-Raman spectroscopy was also used to follow the related structural modifications. Raman spectra show the progressive vanishing and randomization of crystal phonon modes in relation to the ion-induced damage. For crystalline samples irradiated at high fluences (⩾10(14) cm(-2)), only two prominent broad bands remain like for amorphous films, thereby reflecting the phonon density of states of the disordered solid, regardless of samples and irradiation conditions. The main band peaked at ~660 cm(-1) is assigned to vibration modes of randomized bonds in tetrahedral (FeO4) units.

  10. Biodistribution of Yttrium-90-Labeled Anti-CD45 Antibody in a Nonhuman Primate Model

    Energy Technology Data Exchange (ETDEWEB)

    Nemecek, Eneida; Hamlin, Donald K.; Fisher, Darrell R.; Krohn, Kenneth A.; Pagel, John M.; Applebaum, F. R.; Press, Oliver W.; Matthews, Dana C.

    2005-01-15

    Radioimmunotherapy may improve the outcome of hematopoietic cell transplantation for hematologic malignancies by delivering targeted radiation to hematopoietic organs while relatively sparing nontarget organs. We evaluated the organ localization of yttrium-90-labeled anti-CD45 (90Y-anti-CD45) antibody in macaques, a model that had previously predicted iodine-131-labeled anti-CD-45 (131I-anti-CD45) antibody biodistribution in humans. Experimental Design: Twelve Macaca nemestrina primates received anti-CD45 antibody labeled with 1 to 2 mCi of 90Y followed by serial blood sampling and marrow and lymph node biopsies, and necropsy. The content of 90Y per gram of tissue was determined by liquid scintillation spectrometry. Time-activity curves were constructed using average isotope concentrations in each tissue at measured time points to yield the fractional residence time and estimate radiation absorbed doses for each organ per unit of administered activity. The biodistribution of 90Y-anti-CD45 antibody was then compared with that previously obtained with 131I-anti-CD45 antibody in macaques. Results: The spleen received 2,120, marrow 1,060, and lymph nodes 315 cGy/mCi of 90Y injected. The liver and lungs were the nontarget organs receiving the highest radiation absorbed doses (440 and 285 cGy/mCi, respectively). Ytrrium-90-labeled anti-CD45 antibody delivered 2.5- and 3.7-fold more radiation to marrow than to liver and lungs, respectively. The ratios previously observed with 131I-antiCD45 antibody were 2.5-and 2.2-fold more radiation to marrow than to liver and lungs, respectively. Conclusions: This study shows that 90Y-anti-CD45 antibody can deliver relatively selective radiation to hematopoietic tissues, with similar ratios of radiation delivered to target versus nontarget organs, as compared with the 131I immunoconjugate in the same animal model.

  11. Bond durability in erbium:yttrium-aluminum-garnet laser-irradiated enamel.

    Science.gov (United States)

    Amaral, F L B; Colucci, V; Souza-Gabriel, A E; Chinelatti, M A; Palma-Dibb, R G; Corona, S A M

    2010-03-01

    This study sought to evaluate the influence of thermocycling and water storage on the microtensile bond strength of composite resin bonded to erbium:yttrium-aluminum-garnet (Er:YAG)-irradiated and bur-prepared enamel. Eighty bovine incisors were selected and sectioned. Specimens were ground to produce a flat enamel surface. Samples were randomly assigned according to cavity preparation device: (I) Er:YAG laser and (II) high-speed turbine, and were subsequently restored with composite resin. They were subdivided according to the duration of water storage (WS)/number of thermocycles (TCs): 24 h WS/no TCs; 7 days WS/500 TCs; 1 month WS/2,000 TCs; 6 months WS/12,000 TCs. The teeth were sectioned into 1.0 mm(2)-thick slabs and subjected to tensile stress in a universal testing machine. Data were submitted to two-way analysis of variance (ANOVA) and Tukey's test at a 0.05 significance level. The different periods of water storage and thermocycling did not influence the microtensile bond strength (microTBS) values in the Er:YAG laser-prepared groups. In bur-prepared enamel, the group submitted to 12,000 TCs/6 months' WS (IID) showed a significant decrease in bond strength values when compared to the group stored in water for 24 h and not submitted to thermocycling (IIA), but values were statistically similar to those obtained in all Er:YAG laser groups and in the bur- prepared groups degraded with 500 TCs/1 week WS (IIB) or 2,000 TCs/1 month WS (IIC). It may be concluded that adhesion of an etch-and-rinse adhesive to Er:YAG laser-irradiated enamel was not affected by the methods used to simulate degradation of the adhesive interface and was similar to adhesion in the bur-prepared groups in all periods of water storage and thermocycling.

  12. Yttrium-90 resin microspheres as an adjunct to sorafenib in patients with unresectable hepatocellular carcinoma

    Science.gov (United States)

    Mahvash, Armeen; Murthy, Ravi; Odisio, Bruno C; Raghav, Kanwal Pratap; Girard, Lauren; Cheung, Sheree; Nguyen, Van; Ensor, Joe; Gadani, Sameer; Elsayes, Khaled M; Abdel-Wahab, Reham; Hassan, Manal; Shalaby, Ahmed S; Yao, James C; Wallace, Michael J; Kaseb, Ahmed O

    2016-01-01

    Purpose The safety and efficacy of the combined use of sorafenib and yttrium-90 resin microspheres (Y90 RMS) to treat advanced hepatocellular carcinoma (HCC) is not well established. We determined the incidence of adverse events with this combination therapy in patients with advanced HCC at our institution and analyzed the treatment and survival outcomes. Materials and methods We reviewed the records of 19 patients with Barcelona Clinic Liver Cancer class B or C HCC who underwent treatment with Y90 RMS (for 21 sessions) while receiving full or reduced doses of sorafenib between January 2008 and May 2010. Therapy response was evaluated using Response Evaluation Criteria in Solid Tumors. We evaluated median overall survival (OS) and progression-free survival (PFS) as well as hepatic and extrahepatic disease PFS and incidence of adverse events. Results The median patient age was 67 years, and portal or hepatic venous invasion was present in eight patients (42%). Ten patients received reduced doses of sorafenib. The median Y90 radiation activity delivered was 41.2 mCi. The partial response of Response Evaluation Criteria in Solid Tumors was observed in four patients (19%). The median hepatic disease PFS was 7.82 months, extrahepatic disease PFS was 8.94 months, OS was 19.52 months, and PFS was 6.63 months. Ninety days after treatment with Y90 RMS, five patients (26%) had grade II adverse events and four patients (21%) had grade III adverse events. Conclusion OS and PFS outcomes were superior to those observed in prior studies evaluating sorafenib alone in patients with a similar disease status, warranting further study of this treatment combination. PMID:27574586

  13. Treating and Downstaging Hepatocellular Carcinoma in the Caudate Lobe with Yttrium-90 Radioembolization

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Saad M. [Northwestern University Feinberg School of Medicine, Robert H. Lurie Comprehensive Cancer Center, Department of Radiology, Section of Interventional Radiology (United States); Kulik, Laura [Northwestern University Feinberg School of Medicine, Department of Medicine, Division of Hepatology (United States); Baker, Talia [Northwestern University Feinberg School of Medicine, Division of Transplant Surgery (United States); Ryu, Robert K. [Northwestern University Feinberg School of Medicine, Robert H. Lurie Comprehensive Cancer Center, Department of Radiology, Section of Interventional Radiology (United States); Mulcahy, Mary F. [Northwestern University Feinberg School of Medicine, Department of Medicine, Division of Hematology and Oncology, Robert H. Lurie Comprehensive Cancer Center (United States); Abecassis, Michael [Northwestern University Feinberg School of Medicine, Division of Transplant Surgery (United States); Salem, Riad; Lewandowski, Robert J., E-mail: r-lewandowski@northwestern.edu [Northwestern University Feinberg School of Medicine, Robert H. Lurie Comprehensive Cancer Center, Department of Radiology, Section of Interventional Radiology (United States)

    2012-10-15

    Purpose: This study was designed to determine the technical feasibility, safety, efficacy, and potential to downstage patients to within transplantation criteria when treating patients with hepatocellular carcinoma (HCC) of the caudate lobe using Y90 radioembolization. Methods: During a 4-year period, 8 of 291 patients treated with radioembolization for unresectable HCC had disease involving the caudate lobe. All patients were followed for treatment-related clinical/biochemical toxicities, serum tumor marker response, and treatment response. Imaging response was assessed with the World Health Organization (WHO) and European Association for the Study of the Liver (EASL) classification schemes. Pathologic response was reported as percent necrosis at explantation. Results: Caudate lobe radioembolization was successfully performed in all eight patients. All patients presented with both cirrhosis and portal hypertension. Half were United Network for Organ Sharing (UNOS) stage T3 (n = 4, 50%). Fatigue was reported in half of the patients (n = 4, 50%). One (13%) grade 3/4 bilirubin toxicity was reported. One patient (13%) showed complete tumor response by WHO criteria, and three patients (38%) showed complete response using EASL guidelines. Serum AFP decreased by more than 50% in most patients (n = 6, 75%). Four patients (50%) were UNOS downstaged from T3 to T2, three of who underwent transplantation. One specimen showed histopathologic evidence of 100% complete necrosis, and two specimens demonstrated greater than 50% necrosis. Conclusions: Radioembolization with yttrium-90 appears to be a feasible, safe, and effective treatment option for patients with unresectable caudate lobe HCC. It has the potential to downstage patients to transplantation.

  14. Tattoo removal by Q-switched yttrium aluminium garnet laser: client satisfaction.

    Science.gov (United States)

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

    2017-05-01

    Tattoo removal by Q-switched yttrium aluminium garnet (YAG) lasers is golden standard; however, clients' satisfaction with treatment is little known. To determine clients' satisfaction with tattoo removal. One hundred and fifty-four tattoo removal clients who had attended the private clinic 'Centre for Laser Surgery', Hellerup, Denmark, from 2001 to 2013 completed a questionnaire concerning outcome expectations, level of pain experiences and satisfaction with tattoo removal. The laser surgeon and his team were blinded from data handling. The study design included a minimum 2-year postlaser treatment observation period from 2013 to 2015. Overall, clients were satisfied with their laser treatment; 85% assessed their treatment and results to be acceptable to superb, while 15% assessed their treatment and results to be inferior to unacceptable. Effectiveness relative to colour of tattoo on a scale from 0 (no effect) to 10 (complete removal) scored a mean of blue 9.5, black 9.4, yellow 8.9, red 8.8 and green 6.5. Clients were dissatisfied with green pigment remnants, which could mimic bruising. One hundred and twenty-nine clients (84%) experienced moderate to extreme pain during treatment. Twenty-eight (20%) developed minor scarring. There were many reasons for tattoo removal; e.g. stigmatisation (33%), conspicuousness (29%) and poor artistic quality (22%). One hundred and two clients had expected complete removal of tattoos without a blemish, expectations that were only partly fulfilled. During the treatment period, clients adjusted expectations and adapted more realistic views of outcomes. The majority of clients were satisfied with Q-switched YAG laser removal of tattoos despite high pretreatment expectations which were only partly met. The study supports YAG lasers for tattoo removal as acceptable therapy of today, with room for new approaches. © 2017 European Academy of Dermatology and Venereology.

  15. Yttrium-90 Radioembolization for Unresectable Standard-chemorefractory Intrahepatic Cholangiocarcinoma: Survival, Efficacy, and Safety Study

    Energy Technology Data Exchange (ETDEWEB)

    Rafi, Shoaib; Piduru, Sarat M. [Emory University School of Medicine, Division of Interventional Radiology and Image Guided Medicine, Department of Radiology (United States); El-Rayes, Bassel; Kauh, John S. [Emory University School of Medicine, Department of Hematology and Medical Oncology (United States); Kooby, David A.; Sarmiento, Juan M. [Emory University School of Medicine, Department of Surgical Oncology in Surgery (United States); Kim, Hyun S., E-mail: kevin.kim@emory.edu [Emory University School of Medicine, Division of Interventional Radiology and Image Guided Medicine, Department of Radiology (United States)

    2013-04-15

    To assess the overall survival, efficacy, and safety of radioembolization with yttrium-90 (Y90) for unresectable standard-chemorefractory intrahepatic cholangiocarcinoma (ICC). Patients with unresectable standard-chemorefractory ICC treated with Y90 were studied. Survival was calculated from the date of first Y90 procedure. Tumor response was assessed with the Response Evaluation Criteria in Solid Tumors criteria on follow-up computed tomography or magnetic resonance imaging scans. National Cancer Institute Common Terminology Criteria (NCI CTCAE), version 3, were used for complications. Statistical analysis was performed by the Kaplan-Meier estimator by the log rank test. Nineteen patients underwent a total of 24 resin-based Y90 treatments. Median survival from the time of diagnosis and first Y90 procedure was 752 {+-} 193 [95 % confidence interval (CI) 374-1130] and 345 {+-} 128 (95 % CI 95-595) days, respectively. Median survival with Eastern Cooperative Oncology Group (ECOG) performance status 1 (n = 15) and ECOG performance status 2 (n = 4) was 450 {+-} 190 (95 % CI 78-822) and 345 {+-} 227 (95 % CI 0-790) days, respectively (p = .214). Patients with extrahepatic metastasis (n = 11) had a median survival of 404 {+-} 309 (95 % CI 0-1010) days versus 345 {+-} 117 (95 % CI 115-575) days for patients without metastasis (n = 8) (p = .491). No mortality was reported within 30 days from first Y90 radioembolization. One patient developed grade 3 thrombocytopenia as assessed by NCI CTCAE. Fatigue and transient abdominal pain were observed in 4 (21 %) and 6 (32 %) patients, respectively. Y90 radioembolization is effective for unresectable standard-chemorefractory ICC.

  16. Spectrofluorimetric quantification of bilirubin using yttrium-norfloxacin complex as a fluorescence probe in serum samples

    Energy Technology Data Exchange (ETDEWEB)

    Kamruzzaman, Mohammad; Alam, Al-Mahmnur [Department of Chemistry, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Hak Lee, Sang, E-mail: shlee@knu.ac.kr [Department of Chemistry, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Ho Kim, Young, E-mail: youngkim@knu.ac.kr [Research Institute of Advanced Energy Technology, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Kim, Gyu-Man [School of Mechanical Engineering, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Hyub Oh, Sang [Center for Gas Analysis, Korea Research Institute of Standards and Science, Daejeon 305-600 (Korea, Republic of)

    2012-11-15

    A simple and sensitive spectrofluorimetric method was developed to determine trace amounts of bilirubin (BR) using yttrium (Y{sup 3+})-norfloxacin (NFLX) complex as a fluorescence (FL) probe. NFLX can form a stable binary complex with Y{sup 3+} and markedly enhances the weak FL signal of the NFLX. The FL intensity of the Y{sup 3+}-NFLX complex decreased significantly in the presence of BR in a buffer solution at pH=7.2. Under optimal conditions, the FL intensity decreased according to the BR concentration and showed a good linear relationship in the range of 0.03-2.3 {mu}g mL{sup -1} of BR with a correlation coefficient of 0.9988. The limit of detection for the determination of BR was 2.8 ng mL{sup -1} with a relative standard deviation (RSD) of 1.55% for five replicate determination of 0.05 {mu}g mL{sup -1} BR. The presented method offers higher sensitivity with simple instrumentation and was applied successfully in detecting BR at low concentrations. Highlights: Black-Right-Pointing-Pointer Weak FL signal of NFLX was enhanced at 419 nm by forming binary complex with Y{sup 3+}. Black-Right-Pointing-Pointer The FL intensity of Y{sup 3+}-NFLX complex was quenched markedly in the presence of ATP. Black-Right-Pointing-Pointer NFLX can transfer energy to Y{sup 3+} and BR and form the Y{sup 3+}-NFLX-ATP ternary complex. Black-Right-Pointing-Pointer The reduced FL intensity of the system was correlated with the concentration of BR. Black-Right-Pointing-Pointer The method is applied to determine BR at low concentration (2.8 ng mL{sup -1}) in serum.

  17. Spectrographic determination of strontium in yttrium-90 solutions; Determinacion espectrografica de estroncio en soluciones de itrio-90

    Energy Technology Data Exchange (ETDEWEB)

    Roca, M.; Capdevila, C.

    1970-07-01

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

  18. Spin Seebeck effect and spin Hall magnetoresistance at high temperatures for a Pt/yttrium iron garnet hybrid structure

    Science.gov (United States)

    Wang, Shuanhu; Zou, Lvkuan; Zhang, Xu; Cai, Jianwang; Wang, Shufang; Shen, Baogen; Sun, Jirong

    2015-10-01

    Based on unique experimental setups, the temperature dependences of the longitudinal spin Seebeck effect (LSSE) and spin Hall magnetoresistance (SMR) of the Pt/yttrium iron garnet (Pt/YIG) hybrid structure are determined in a wide temperature range up to the Curie temperature of YIG. From a theoretical analysis of the experimental relationship between the SMR and temperature, the spin mixing conductance of the Pt/YIG interface is deduced as a function of temperature. Adopting the deduced spin mixing conductance, the temperature dependence of the LSSE is well reproduced based on the magnon spin current theory. Our research sheds new light on the controversy about the theoretical models for the LSSE.

  19. Analysis of inner filter effect on the up-conversion spectra of erbium doped yttrium oxide close-packed powders

    Science.gov (United States)

    Rakov, Nikifor; Maciel, Glauco S.

    2012-11-01

    We observed that the up-conversion (UC) emission profiles of erbium (Er3+) doped yttrium oxide (Y2O3) close-packed powders prepared by combustion synthesis are different when the luminescence reflected from the sample is compared to the luminescence transmitted through the sample (thickness: ˜0.1 mm). The effect was identified as a combination of scattering and an inner filter effect (IFE). The IFE reduces the transmitted UC luminescence bandwidths up to 50%. The IFE was suppressed by the inclusion of free-standing undoped Y2O3 particles.

  20. Laser MBE-grown yttrium iron garnet films on GaN: characterization of the crystal structure and magnetic properties

    Science.gov (United States)

    Kaveev, A. K.; Bursian, V. E.; Gastev, S. V.; Krichevtsov, B. B.; Suturin, S. M.; Volkov, M. P.; Sokolov, N. S.

    2016-07-01

    Yttrium iron garnet (YIG) films were grown on GaN substrates using the laser molecular beam epitaxy method. X-ray diffraction data showed polycrystalline YIG layers without additional structural modifications. The magnetic properties of the YIG films were studied at room temperature with the aid of a vibration sample magnetometer, the magneto-optical Kerr effect and ferromagnetic resonance methods. ‘Easy-plane’-type magnetic anisotropy was found in the films. The gyromagnetic ratio and 4 πMS value were calculated.

  1. Pregnancies in women with hyperprolactinaemia: clinical course and obstetric complications of 41 pregnancies in 27 women. [Yttrium 90

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, W.F.; Doyle, F.H.; Mashiter, K.; Banks, L.M.; Gordon, H.; Joplin, G.F.

    1979-09-01

    Observations are reported on 41 pregnancies in 27 patients who initially had infertility and raised serum prolactin concentrations. Associated symptoms were secondary amenorrhoea and galactorrhoea. All patients were at risk of pituitary expansion during pregnancy, especially these 19 (70 per cent) with radiological evidence of pituitary tumors. Fifteen patients had 21 pregnancies after pituitary implantation with 90 yttrium; 14 patients had 20 pegnancies without prior pituitary implantation or any other attempt to prevent tumor expansion. The induction and Cesarean section rates were about 30 per cent in 32 term pregnancies in 25 patients. Details of how pregnancy was achieved and the associated obstetric problems are given.

  2. Dielectric relaxation in double potassium yttrium orthophosphate K 3Y(PO 4) 2 doped by praseodymium and dysprosium ions

    Science.gov (United States)

    Szulia, S.; Kosmowska, M.; Kołodziej, H. A.; Mizer, D.; Czupińska, G.

    2011-12-01

    We report the paper presents the results of electric properties of double potassium yttrium orthophosphates doped by lanthanide ions K 3Y( 1-x)Ln x(PO 4) 2 ( x = 0.01, 0.05, Ln = Pr 3+, Dy 3+). Electric permittivity and dielectric loss measurements have been performed on polycrystalline samples in the temperature range -50-120 °C and frequency range 1 kHz-1 MHz by means of HP 4282A impedance meter. The frequency and temperature dependence of electric properties were analyzed by theoretical models of dielectric relaxation in order to obtain information abut molecular dynamic of our solids in external electric field.

  3. Self-stabilized and dispersion-compensated passively mode-locked Yb:Yttrium aluminum garnet laser

    Science.gov (United States)

    Agnesi, A.; Guandalini, A.; Reali, G.

    2005-04-01

    Self-stabilized passive mode-locking of a diode-pumped Yb:yttrium aluminum garnet laser with a semiconductor saturable absorber was achieved using an off-phase-matching second-harmonic crystal. According to the numerical model, such a condition is accomplished by self-defocusing in the nonlinear crystal in the presence of positive intracavity dispersion. Robust mode locking with Fourier-limited 1.0-ps pulses was obtained, whereas mode locking, unassisted by the nonlinear crystal, yielded 2.2-ps pulses, with the laser operating near the edge of the stability region in order to minimize the saturation energy of the semiconductor device.

  4. Observation of two-dimensional yttrium oxide nanoparticles in mealworm beetles (Tenebrio molitor).

    Science.gov (United States)

    Chen, Yunyun; Sanchez, Carlos; Yue, Yuan; González, Jorge M; Parkinson, Dilworth Y; Liang, Hong

    2016-09-01

    Nanomaterials are being used in medicine, manufacturing and consumer products, but their effects on organisms and the environment are not well understood because of the difficulty in detecting them. Here dual-energy X-ray K-edge subtraction was used to track two-dimensional yttrium oxide nanoparticles (which can be found in such household objects as color televisions) in adult mealworms (Tenebrio molitor). The insects ingested nanoparticle-infused feed for different time periods, up to 24 h, and the nanoparticles could then be identified at several locations in the insects' head, thorax and abdomen, mostly within the digestive tract. In time, all particles were excreted.

  5. Thermal effects from modified endodontic laser tips used in the apical third of root canals with erbium-doped yttrium aluminium garnet and erbium, chromium-doped yttrium scandium gallium garnet lasers.

    Science.gov (United States)

    George, Roy; Walsh, Laurence J

    2010-04-01

    To evaluate the temperature changes occurring on the apical third of root surfaces when erbium-doped yttrium aluminium garnet (Er:YAG) and erbium, chromium-doped yttrium scandium gallium garnet (Er,Cr:YSGG) laser energy was delivered with a tube etched, laterally emitting conical tip and a conventional bare design optical fiber tip. Thermal effects of root canal laser treatments on periodontal ligament cells and alveolar bone are of concern in terms of safety. A total of 64 single-rooted extracted teeth were prepared 1 mm short of the working length using rotary nickel-titanium Pro-Taper files to an apical size corresponding to a F5 Pro-Taper instrument. A thermocouple located 2 mm from the apex was used to record temperature changes arising from delivery of laser energy through laterally emitting conical tips or plain tips, using an Er:YAG or Er,Cr:YSGG laser. For the Er:YAG and Er,Cr:YSGG systems, conical fibers showed greater lateral emissions (452 + 69% and 443 + 64%) and corresponding lower forward emissions (48 + 5% and 49 + 5%) than conventional plain-fiber tips. All four combinations of laser system and fiber design elicited temperature increases less than 2.5 degrees C during lasing. The use of water irrigation attenuated completely the thermal effects of individual lasing cycles. Laterally emitting conical fiber tips can be used safely under defined conditions for intracanal irradiation without harmful thermal effects on the periodontal apparatus.

  6. Linear optical properties and their bond length dependence of yttrium bromide from ab initio and density functional theory calculations

    Energy Technology Data Exchange (ETDEWEB)

    Alipour, Mojtaba, E-mail: malipour@shirazu.ac.ir [Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Mohajeri, Afshan, E-mail: amohajeri@shirazu.ac.ir [Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of)

    2011-08-25

    Graphical abstract: The electronic properties such as the static dipole polarizability, anisotropy of the polarizability, and dipole moment of yttrium bromide, YBr (X{sup 1}{Sigma}) have been theoretically studied. Highlights: {yields} Conventional ab initio and density functional theory methods were employed to study linear optical properties of YBr molecule. {yields} Properties derivatives and their level of theory dependence were studied. {yields} Electron correlation effects and rovibrational corrections have also been discussed. - Abstract: We have employed conventional ab initio and density functional theory methods to study the electronic properties such as the mean static dipole polarizability, {alpha}-bar, anisotropy of the polarizability, {Delta}{alpha}, and dipole moment, {mu}, of yttrium bromide. The bond length dependence of properties is determined at different levels of theory and appropriate expansions around experimental internuclear distance have been presented. Moreover, the first and second geometrical derivatives for each property are quantified and their level of theory dependence has been analyzed. To study the effect of molecular rotation and vibration on the electronic properties, the rovibrational corrections have also been carried out. It is found that these corrections are less pronounced for considered properties of YBr. In all calculations, the electron correlation effects have been considered and discussed. The obtained results show that the electron correlation is more significant in the calculation of the mean and the anisotropy of dipole polarizability.

  7. Measurement of Cross-sections of Yttrium (n,xn) Threshold Reactions by Means of Gamma Spectroscopy

    Science.gov (United States)

    Chudoba, P.; Kilim, S.; Wagner, V.; Vrzalova, J.; Svoboda, O.; Majerle, M.; Stefanik, M.; Suchopar, M.; Kugler, A.; Bielewicz, M.; Strugalska-Gola, E.; Szuta, M.; Hervas, D.; Herman, T.; Geier, B.

    Neutron activation and gamma spectrometry are usable also for the determination of cross-sections of different neutron reactions. We have studied the cross-section of yttrium (n,xn) threshold reactions using quasi mono-energetic neutron source based on the reaction on 7Li target at Nuclear Physics Institute of ASCR in Rez. Yttrium (n,xn) threshold reactions are suitable candidates for fast neutron field measurement by activation detectors. Fast neutron field monitoring is necessary already today at a wide range of accelerator facilities and will gain on importance in future fast reactors of generation IV, accelerator transmutation systems or fusion reactors. The knowledge of the cross-sections is crucial for such purpose. Unfortunately, the cross-section is sufficiently known only for 89Y(n,2n)88Y reaction. For higher orders of reactions there are almost no experimental data. Special attention was paid to the 89Y(n,3n)87Y reaction. The nuclei are produced, both in the ground state with half-life 79.8 hours and in the isomeric state with half-life 13.38 hours. The isomer decays mainly through the gamma transition to the ground state, the beta decay of the excited state is negligible within our accuracy. The cross-sections of both 87Y productions were analyzed.

  8. Measurement of cross-sections of yttrium (n,xn) threshold reactions by means of gamma spectroscopy

    CERN Document Server

    Chudoba, Petr; Wagner, V; Vrzalova, J; Svoboda, O; Majerle, M; Stefanik, M; Suchopar, M; Kugler, A; Bielewicz, M; Strugalska-Gola, E; Szuta, M; Hervas, D; Herman, T; Geier, B

    2014-01-01

    Neutron activation and gamma spectrometry are usable also f or the determination of cross-sections of different neutron reactions. We have studied the cross-sections of yttrium (n, x n) threshold reactions using quasi-monoenergetic neutron source based on the reaction on 7 Li target at Nuclear Physics Institute of ASCR in Rez. Yttrium (n, x n) threshold reactions are suitable candidates for fast neutron field measurement by activation detectors. Fast neutron field monitoring is necessary already today at a wide range of accelerator facilities and will gain on importance in future fast reactors of generation IV, accelerator transmutation systems or fusion reactors. The knowledge of the cross-sections is crucial for such purpose. Unfortunately, the cross-section is sufficiently known only for 89 Y(n,2n) 88 Y reaction. For higher orders of reactions there are almost no experimental data. Special attention was paid to t he 89 Y(n,3n) 87 Y reaction. The cross-sections of both 89 Y(n,2n) 88 Y and 89 Y(n,3n) 87 Y re...

  9. Thickness and component distributions of yttrium-titanium alloy films in electron-beam physical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    LI ShuaiHui; SHU YongHua; FAN Jing

    2008-01-01

    Thickness and component distributions of large-area thin films are an issue of in-ternational concern in the field of material processing. The present wor0k employs experiments and direct simulation Monte Carlo (DSMC) method to investigate three-dimensional low-density, non-equilibrium jets of yttrium and titanium vapor atoms in an electron-beams physical vapor deposition (EBPVD) system furnished with two or three electron-beams, and obtains their deposition thickness and component distributions onto 4-inch and 6-inch mono-crystal silicon wafers. The DSMC results are found in excellent agreement with our measurements, such as evaporation rates of yttrium and titanium measured in-situ by quartz crystal reso-nators, deposited film thickness distribution measured by Rutherford backscat-tering spectrometer (RBS) and surface profilometer and deposited film molar ratio distribution measured by RBS and inductively coupled plasma atomic emission spectrometer (ICP-AES). This can be taken as an indication that a combination of DSMC method with elaborate measurements may be satisfactory for predicting and designing accurately the transport process of EBPVD at the atomic level.

  10. Lobar Hepatocellular Carcinoma with Ipsilateral Portal Vein Tumor Thrombosis Treated with Yttrium-90 Glass Microsphere Radioembolization: Preliminary Results

    Directory of Open Access Journals (Sweden)

    M. Pracht

    2013-01-01

    Full Text Available Portal vein tumor thrombosis (PVTT is a common complication of hepatocellular carcinoma (HCC and has a negative impact on prognosis. This characteristic feature led to the rationale of the present trial designed to assess the efficacy and the safety of yttrium-90 glass-microsphere treatment for advanced-stage lobar HCC with ipsilateral PVTT. 18 patients with unresectable lobar HCC and ipsilateral PVTT were treated in our institution with 90Y-microS radioembolization. Patients were evaluated every 3 to 6 months for response, survival, and toxicity. Mean follow-up was 13.0 months (2.2–50.6. Outcomes were: complete response (n=2, partial response (n=13, stable disease (n=1, and progressive disease (n=2 giving a disease control rate of 88.9%. Four patients were downstaged. Treating lobar hepatocellular carcinoma with ipsilateral portal vein thrombosis with yttrium-90 glass-microsphere radioembolization is safe and efficacious. Further clinical trials are warranted to confirm these results and to compare 90Y-microS with sorafenib, taking into account not only survival but also the possibility of secondary surgery for putative curative intention after downstaging.

  11. Thickness and component distributions of yttrium-titanium alloy films in electron-beam physical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Thickness and component distributions of large-area thin films are an issue of in-ternational concern in the field of material processing. The present work employs experiments and direct simulation Monte Carlo (DSMC) method to investigate three-dimensional low-density, non-equilibrium jets of yttrium and titanium vapor atoms in an electron-beams physical vapor deposition (EBPVD) system furnished with two or three electron-beams, and obtains their deposition thickness and component distributions onto 4-inch and 6-inch mono-crystal silicon wafers. The DSMC results are found in excellent agreement with our measurements, such as evaporation rates of yttrium and titanium measured in-situ by quartz crystal reso-nators, deposited film thickness distribution measured by Rutherford backscat-tering spectrometer (RBS) and surface profilometer and deposited film molar ratio distribution measured by RBS and inductively coupled plasma atomic emission spectrometer (ICP-AES). This can be taken as an indication that a combination of DSMC method with elaborate measurements may be satisfactory for predicting and designing accurately the transport process of EBPVD at the atomic level.

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

    Directory of Open Access Journals (Sweden)

    A. E. Baranchikov

    2015-09-01

    Full Text Available Subject of Study. The paper presents results of characterization for neodymium doped yttrium aluminum garnet nanopowders - YAG:Nd3+ by the method of scanning electronic microscopy. Method. Synthesis of YAG:Nd3+ was carried out by sol-gel method from nitrate or acetate - nitrate solutions with addition of some organic compounds and ammonia as well. Such substances were used as the source ones: oxides of neodymium and yttrium with the content of the basic substance equal to 99.999 %; organic compounds: citric acid with the content of the basic substance not less than 99.0 %; ethylene glycol (99.5%; the ammonium lauryl sulfate (99.0 %; urea (99.0 % of Alfa Aesar, Fluka, Aldrich companies. Oxides of yttrium and neodymium (5 at. % were dissolved in 50% acetic acid, nitrate aluminum was added with a view to the resulting product Y2,85Nd0,15Al5,0O12, the solution was stirred and heated to 60С before reaching its transparency and uniformity. The weight of the portion corresponding to the stoichiometry YAG was 2.0 g. 50 % aqueous solutions of organic substances or 5% NH4OH in a weight ratio of 1:1 to the weight of the garnet were added in aqueous solutions, placed into glass cups. The solutions were thoroughly mixed first using a conventional stirrer, then on ultrasonic installation with simultaneous 60 С heating for 2 hours. Drying of solutions to the consistency of a powder or a thick gel was carried out at 110 С. Then the samples were placed into platinum cups and annealed in a tube furnace at 950 - 1050 С for the period from 0.5 to 2 hours. Additional annealing of the powders in the air at 950 - 1060С were carried out for the purpose of powders clarifying for residual amorphous carbon removal. Main Results. The synthesized powder precursors and powders after annealing were examined using a polarizing microscope to identify anisotropic crystalline phases. X-ray analysis of the synthesized samples was carried out on a DRON - 4 and UDR - 63

  13. Quantitative and qualitative assessment of Yttrium-90 PET/CT imaging.

    Directory of Open Access Journals (Sweden)

    Ali Asgar Attarwala

    Full Text Available Yttrium-90 is known to have a low positron emission decay of 32 ppm that may allow for personalized dosimetry of liver cancer therapy with (90Y labeled microspheres. The aim of this work was to image and quantify (90Y so that accurate predictions of the absorbed dose can be made. The measurements were performed within the QUEST study (University of Sydney, and Sirtex Medical, Australia. A NEMA IEC body phantom containing 6 fillable spheres (10-37 mm ∅ was used to measure the 90Y distribution with a Biograph mCT PET/CT (Siemens, Erlangen, Germany with time-of-flight (TOF acquisition. A sphere to background ratio of 8:1, with a total (90Y activity of 3 GBq was used. Measurements were performed for one week (0, 3, 5 and 7 d. he acquisition protocol consisted of 30 min-2 bed positions and 120 min-single bed position. Images were reconstructed with 3D ordered subset expectation maximization (OSEM and point spread function (PSF for iteration numbers of 1-12 with 21 (TOF and 24 (non-TOF subsets and CT based attenuation and scatter correction. Convergence of algorithms and activity recovery was assessed based on regions-of-interest (ROI analysis of the background (100 voxels, spheres (4 voxels and the central low density insert (25 voxels. For the largest sphere, the recovery coefficient (RC values for the 30 min -2-bed position, 30 min-single bed and 120 min-single bed were 1.12 ± 0.20, 1.14 ± 0.13, 0.97 ± 0.07 respectively. For the smaller diameter spheres, the PSF algorithm with TOF and single bed acquisition provided a comparatively better activity recovery. Quantification of Y-90 using Biograph mCT PET/CT is possible with a reasonable accuracy, the limitations being the size of the lesion and the activity concentration present. At this stage, based on our study, it seems advantageous to use different protocols depending on the size of the lesion.

  14. Effect of yttrium on photosynthesis and water relations in young maize plants

    Institute of Scientific and Technical Information of China (English)

    Ivana Maksimovi; Rudolf Kastori; Marina Putnik-Deli; Milan Boriev

    2014-01-01

    Despite an increase in spectrum of industrial applications of yttrium (Y) and the fact that it is widely present in the soils and plants, some of which are agronomically important crops, its effects on plant growth and metabolism are still obscure. Therefore, the aim of this work was to examine the effect of different concentrations of Y on its accumulation and distribution, photosynthetic responses, water relations, free proline concentration and growth of young maize plants. The experiment was done with maize (Zea mays L., hybrid NS-640), in water cultures, under semi-controlled conditions of a greenhouse. Plants were supplied with half-strength complete Hoagland nutrient solution, to which was added either 0 (control), 10-5, 10-4 or 10-3 mol/L Y, in the form of Y(NO)3·5H2O. Each variant was set in thirteen replications, with six plants in each replication. Plants were grown for 21 d and they were at the stage of 3 and 4 leaves when they were analyzed. The presence of Y reduced maize growth and photosynthetic performance. Dimensions of stomata significantly decreased while their density significantly increased on both adaxial and abaxial epidermis. Plant height, root length, total leaf area and dry mass also declined. Concentration of photosynthetic pigments (chl a and b and carotenoids) and free proline decreased. Photosynthesis and transpiration were impaired in the presence of Y-their intensities were also reduced, and the same stands for stomatal conductance of water vapor, photosynthetic water use efficiency (WUE) and water content. Although the highest concentration of Y was found in maize roots in each treatment, Y concentration in the second leaf and shoot also significantly increased with an increase in Y concentration in the nutrient solution. Albeit Y concentration was much higher in roots than in shoots, shoot metabolism and growth were much more disrupted. The results demonstrated that young maize plants accumulated significant amount of Y and that

  15. Robust Multifunctional Yttrium-Based Metal-Organic Frameworks with Breathing Effect.

    Science.gov (United States)

    Firmino, Ana D G; Mendes, Ricardo F; Antunes, Margarida M; Barbosa, Paula C; Vilela, Sérgio M F; Valente, Anabela A; Figueiredo, Filipe M L; Tomé, João P C; Paz, Filipe A Almeida

    2017-02-06

    Phosphonate- and yttrium-based metal-organic frameworks (MOFs), formulated as [Y(H5btp)]·5.5H2O (1), [Y(H5btp)]·2.5H2O (2), (H3O)[Y2(H5btp)(H4btp)]·H2O (3), and [Y(H5btp)]·H2O·0.5(MeOH) (4), were prepared using a "green" microwave-assisted synthesis methodology which promoted the self-assembly of the tetraphosphonic organic linker [1,1'-biphenyl]-3,3',5,5'-tetrayltetrakis(phosphonic acid) (H8btp) with Y(3+) cations. This new family of functional materials, isolated in bulk quantities, exhibits a remarkable breathing effect. Structural flexibility was thoroughly studied by means of X-ray crystallography, thermogravimetry, variable-temperature X-ray diffraction, and dehydration and rehydration processes, ultimately evidencing a remarkable reversible single-crystal to single-crystal (SC-SC) transformation solely through the loss and gain of crystallization solvent molecules. Topologically, frameworks remained unaltered throughout this interconversion mechanism, with all compounds being binodal 6,6-connected network with a Schäfli symbol of {4(13).6(2)}{4(8).6(6).8}. Results show that this is one of the most stable and thermally robust families of tetraphosphonate-based MOFs synthesized reported to date. Porous materials 2 and 3 were further studied to ascertain their performance as heterogeneous catalysts and proton conductors, respectively, with outstanding results being registered for both materials. Compound 2 showed a 94% conversion of benzaldehyde into (dimethoxymethyl)benzene after just 1 h of reaction, among the best results registered to date for MOF materials. On the other hand, the protonic conductivity of compound 3 at 98% of relative humidity (2.58 × 10(-2) S cm(-1)) was among the highest registered among MOFs, with the great advantage of the material to be prepared using a simpler and sustainable synthesis methodology, as well as exhibiting a good stability at ambient conditions (temperature and humidity) over time when compared to others.

  16. Bose–Einstein condensation and superfluidity of magnons in yttrium iron garnet films

    Science.gov (United States)

    Sun, Chen; Nattermann, Thomas; Pokrovsky, Valery L.

    2017-04-01

    A brief review of the theory of quasi-equilibrium Bose–Einstein condensation and superfluidity of magnons in a film of yttrium iron garnet is presented. The Bose–Einstein condensation of magnons in YIG film at room temperature under rf pumping was discovered in 2006 by the Münster experimental team led by Demokritov. There are two symmetric minima in the magnon spectrum of a ferromagnetic film, and therefore two condensates. In 2012 the same experimental group discovered the interference of these two condensates, thus proving their coherence. The reviewed theory that explains these experimental observations predicts that the reflection symmetry of the magnon gas is spontaneously violated at Bose–Einstein condensation in thick films. In thin films the condensate is symmetric at low magnetic field and transits to the non-symmetric state at higher field. Dipolar interaction energy depends on the phase of the condensate wave function. In quasi-equilibrium it traps the phase. All these features are due to the interaction between magnons Since the magnon condensate is coherent, a logical question is whether the condensate is superfluid. Two obstacles for superfluidity are the dominance of the normal magnon density over the condensate (approximately 100-fold) and the phase trapping. We show that the velocity of the superfluid part is by 5–7 decimal orders larger than that of the normal part at typical values of the field gradients. Thus, the spin current is mainly superfluid. The phase trapping violates the U(1) symmetry, reducing it to a discrete symmetry. Stationary superfluid flow is still possible, but it becomes inhomogeneous. In 1-d stationary flow at low kinetic energy the condensate phase over long intervals of length remains close to the trapped values and changes by 2π within comparatively short intervals (phase solitons). The current and number of magnons are conserved globally but not locally, since they transfer spin momentum to the lattice. These

  17. Thermal stability of platinum, palladium and silver films on yttrium-stabilised zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Gesa, E-mail: gesa.beck@physik.uni-augsburg.de [Chair of Resource Strategy, Institute of Physics, University Augsburg, Universitaetsstrasse 1a, 86159 Augsburg (Germany); Bachmann, Christoph [Institute of Physical Chemistry, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 58, 35392 Giessen (Germany); Bretzler, Rita [Research Institute Precious Metals and Metals Chemistry, Katharinenstrasse 17, 73525 Schwaebisch Gmuend (Germany); Kmeth, Ralf [Chair of Resource Strategy, Institute of Physics, University Augsburg, Universitaetsstrasse 1a, 86159 Augsburg (Germany)

    2014-12-31

    Platinum, palladium and silver films with different microstructures have been prepared on differently orientated yttrium-stabilised zirconia (YSZ) substrates by pulsed laser deposition and then annealed at temperatures between 200 °C and 850 °C. Thereby, an influence of the type of metal, of the microstructure of the as-prepared film and of the orientation of the substrate on the annealing behaviour could be determined. The following annealing effects were observed for platinum, palladium and silver films: i) sharpening of the film boundary, ii) smoothing of the film surfaces, iii) sharpening of the texture [thereby: reduction of the fraction of small angle and twin grain boundaries], iv) grain growth and accordingly reduction of the fraction of grains as well as v) grooving at grain boundaries, vi) void formation at the metal|YSZ-interface, vii) hole formation within the films and viii) reduction of the fraction of droplets. In the case of palladium films also ix) oxidation [between 300 °C ≤ T < 750 °C] and stronger de-wetting phenomena than for platinum [with x) waving of the film and xi) island formation at T ≥ 750 °C] have been found. Silver films are not oxidised, but show stronger de-wetting phenomena than platinum and palladium, with xi) island formation and xii) evaporation of the silver at T ≥ 550 °C. Interestingly, silver films on (111) orientated YSZ are thermally much more stable than silver films on the other orientated substrates up to 750 °C. The annealing effects were described by interface, grain boundary and surface energy minimization. - Highlights: • The thermal stability of Pt, Pd and Ag films has been investigated up to 850 °C. • Annealing effects are e.g. reduction of the fraction of twins and island formation. • Pd is also oxidised between 300 °C ≤ T < 750 °C. • Annealing effects depend on type of metal and on its initial microstructure. • Annealing effects depend also on the orientation of substrate.

  18. Influence of potassium on the competition between methane and ethane in steam reforming over Pt supported on yttrium-stabilized zirconia.

    NARCIS (Netherlands)

    Graf, P.O.; Mojet, Barbara; Lefferts, Leonardus

    2008-01-01

    effect of addition of potassium to Pt supported on yttrium-stabilized zirconia (PtYSZ) catalyst for steam reforming of methane, ethane and methane/ethane mixtures was explored. Addition of potassium has a positive effect on preferential steam reforming of methane in mixtures of methane and ethane

  19. Simultaneous detection of the spin-Hall magnetoresistance and the spin-Seebeck effect in platinum and tantalum on yttrium iron garnet

    NARCIS (Netherlands)

    Vlietstra, N.; Shan, J.; van Wees, B. J.; Isasa, M.; Casanova, F.; Ben Youssef, J.

    2014-01-01

    The spin-Seebeck effect (SSE) in platinum (Pt) and tantalum (Ta) on yttrium iron garnet has been investigated by both externally heating the sample (using an on-chip Pt heater on top of the device) and by current-induced heating. For SSE measurements, external heating is the most common method to ob

  20. Synthesis, characterization, and activity of yttrium(III) nitrate complexes bearing tripodal phosphine oxide and mixed phosphine-phosphine oxide ligands.

    Science.gov (United States)

    Sues, Peter E; Lough, Alan J; Morris, Robert H

    2012-09-03

    A series of four tripodal phosphine oxide ligands, (OPR(2))(2)CHCH(2)POR(2) (1a-1d), and four mixed phosphine-phosphine oxide ligands, (OPR(2))(2)CHCH(2)PR(2) (3a-3d), were synthesized and coordinated to yttrium to produce Y(NO(3))(3)[(OPR(2))(2)CHCH(2)POR(2)] (2a-2d) and Y(NO(3))(3)[(OPR(2))(2)CHCH(2)PR(2)](OPPh(3)) (4a-4d) complexes. The previously reported ligand 1a and unknown phosphine oxide ligands 1b-1d were generated in an unprecedented trisubstitution reaction of bromoacetaldehyde diethyl acetal, while the novel partially reduced ligands 3a-3d were synthesized from 1a-1d according to a known literature protocol for the selective monoreduction of bisphosphine oxides. The neutral yttrium complexes 2a-2d are nine-coordinate and display a tricapped trigonal-prismatic geometry. Complexes 4a-4d are also neutral, nine-coordinate species and have a pendant phosphine functionality, which provides the potential to form bimetallic early-late transition-metal complexes. Additionally, yttrium complexes 2a-2d were activated with base and tested for the ring-opening polymerization of ε-caprolactone, but the results showed that base by itself was significantly more effective than the yttrium species investigated.

  1. Comparative study of steam reforming of methane, ethane and ethylene on Pt, Rh and Pd supported on yttrium-stabilized zirconia.

    NARCIS (Netherlands)

    Graf, P.O.; Mojet, Barbara; van Ommen, J.G.; Lefferts, Leonardus

    2007-01-01

    In the present paper steam reforming of methane, ethane and ethylene was compared on Pt, Rh and Pd supported on yttrium-stabilized zirconia (YSZ). Both reactivity and product distribution changed with the use of different catalysts. The order of activity for the hydrocarbons on Rh was C2H6 > C2H4 >

  2. Influence of potassium on the competition between methane and ethane in steam reforming over Pt supported on yttrium-stabilized zirconia.

    NARCIS (Netherlands)

    Graf, P.O.; Mojet, Barbara; Lefferts, Leonardus

    2008-01-01

    effect of addition of potassium to Pt supported on yttrium-stabilized zirconia (PtYSZ) catalyst for steam reforming of methane, ethane and methane/ethane mixtures was explored. Addition of potassium has a positive effect on preferential steam reforming of methane in mixtures of methane and ethane ov

  3. Spin-Hall magnetoresistance in platinum on yttrium iron garnet : Dependence on platinum thickness and in-plane/out-of-plane magnetization

    NARCIS (Netherlands)

    Vlietstra, N.; Shan, J.; Castel, V.; van Wees, B. J.; Ben Youssef, J.

    2013-01-01

    The occurrence of spin-Hall magnetoresistance (SMR) in platinum (Pt) on top of yttrium iron garnet (YIG) has been investigated, for both in-plane and out-of-plane applied magnetic fields and for different Pt thicknesses [3, 4, 8, and 35 nm]. Our experiments show that the SMR signal directly depends

  4. Phase III trial of intraperitoneal therapy with yttrium-90-labeled HMFG1 murine monoclonal antibody in patients with epithelial ovarian cancer after a surgically defined complete remission.

    NARCIS (Netherlands)

    Verheijen, R.H.; Massuger, L.F.A.G.; Benigno, B.B.; Epenetos, A.A.; Lopes, A.; Soper, J.T.; Markowska, J.; Vyzula, R.; Jobling, T.; Stamp, G.; Spiegel, G.; Thurston, D.; Falke, T.; Lambert, J.; Seiden, M.V.

    2006-01-01

    PURPOSE: This was a multinational, open-label, randomized phase III trial comparing yttrium-90-labeled murine HMFG1 (90Y-muHMFG1) plus standard treatment versus standard treatment alone in patients with epithelial ovarian cancer (EOC) who had attained a complete clinical remission after

  5. Platinum thickness dependence of the inverse spin-Hall voltage from spin pumping in a hybrid yttrium iron garnet/platinum system

    NARCIS (Netherlands)

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

    2012-01-01

    We show the experimental observation of the platinum thickness dependence in a hybrid yttrium iron garnet/platinum system of the inverse spin-Hall effect from spin pumping, over a large frequency range and for different radio-frequency powers. From the measurement of the voltage at the resonant cond

  6. Activation of O2 and CH4 on yttrium-stabilized zircoma for the partial oxidation of methane to synthesis gas.

    NARCIS (Netherlands)

    Zhu, Jianjun; Ommen, van Jan G.; Bouwmeester, Henny J.M.; Lefferts, Leon

    2005-01-01

    The isotopic exchange reaction on ZrO2 and yttrium-stabilized ZrO2 (YSZ) during catalytic partial oxidation of methane to synthesis gas (CPOM) was studied with transient pulse experiments. The results reveal, surprisingly, that CPOM over both oxides proceeds via a Mars¿van Krevelen mechanism. Despit

  7. Influence of Yttrium Ion-implantation on Oxidation Kinetics of Co-40Cr Alloy and Property of Oxide/Substrate Interface

    Institute of Scientific and Technical Information of China (English)

    JIN Huiming; WU Dan; FELIX Congrado; AROYAVE Hayara

    2007-01-01

    The isothermal and cyclic oxidizing kinetics of Co-40Cr alloy and its yttrium ion-implanted samples were studied at 1000℃ in air by thermal-gravity analysis (TGA). Scanning electronic microscopy (SEM) was used to examine the Cr2O3 oxide film's morphology after oxidation. Secondary ion mass spectroscopy (SIMS) method was used to examine the binding energy change of chromium caused by yttrium doping. Acoustic emission (AE) method was used in situ to monitor the cracking and spalling of oxide films formed on both samples during oxidizing and subsequent air-cooling stages. It is found that yttrium implantation remarkably reduces the isothermal oxidizing rate of Co-40Cr and improves the anti-cracking and anti-spalling properties of Cr2O3 oxide film. The reasons for the improvements are mainly that implanted yttrium reduces the grain size of Cr2O3 oxide, increases the high temperature plasticity of oxide film, and remarkably reduces the number and size of Cr2O3/Co-40Cr interfacial defects.

  8. Influence of potassium on the competition between methane and ethane in steam reforming over Pt supported on yttrium-stabilized zirconia

    NARCIS (Netherlands)

    Graf, Patrick O.; Mojet, Barbara L.; Lefferts, Leon

    2008-01-01

    effect of addition of potassium to Pt supported on yttrium-stabilized zirconia (PtYSZ) catalyst for steam reforming of methane, ethane and methane/ethane mixtures was explored. Addition of potassium has a positive effect on preferential steam reforming of methane in mixtures of methane and ethane ov

  9. Synthesis and characterization of a novel acryl amide-based yttrium imprinted sorbent via the ATRP approach for the preparation of medical-grade {sup 90}Y

    Energy Technology Data Exchange (ETDEWEB)

    Abedi, Mahvash [Nuclear Schience and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Shahid Beheshti Univ., Tehran (Iran, Islamic Republic of). Dept. of Chemistry; Shirvani-Arani, Simindokht; Bahrami-Samani, Ali [Nuclear Schience and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Nabid, Mohammad Reza [Shahid Beheshti Univ., Tehran (Iran, Islamic Republic of). Dept. of Chemistry

    2016-05-01

    Because of its favorable radionuclidic properties (pure beta emitter, E{sub βmax} = 2.28 MeV, T{sub 1/2} = 64.1 h), the preparation of carrier free {sup 90}Y is of a great importance in radiopharmacy. Herein, we report the synthesis, characterization, and application of a novel yttrium sorbent prepared on the basis of the ion-imprinting concept. The ion-imprinted polymer (IIP) was prepared by atom transfer radical copolymerization of acryl amide (AAm, functional monomer) and N,N'-methylenebisacrylamide (MBAAm) crosslinking agent in the presence of a complex of yttrium ions (template ions) with a homemade chelator, i.e., 2,2-bis(2-bromo-2-methylpropanoate)propane-1,3-disuccinate (also as initiator). For elimination of yttrium ions, which act as the template, the prepared particles were treated with 50% v:v HCl: H{sub 2}O to produce yttrium-imprinted polymeric sorbent. To control the imprinting effect, corresponding non-imprinted particles (NIP) were prepared in a similar manner except that yttrium ions were not used. The synthesized chemicals for the preparation of the chelator-initiator compound and the product itself were assessed in every step using {sup 1}H-NMR analysis. NIP and YIP were subjected to X-ray diffraction (XRD), infra-red spectroscopy (IR) and BET surface area analysis for characterization studies. Sorption/desorption studies were conducted, and the effects of potentially interfering ions, such as Sr{sup 2+} (α = 119.69) and Zr{sup 4+} (α = 73.01) in presence of radio-yttrium, were investigated (particle size: 50-100 μm, resultant recovery of > 99% within 60 min and a capacity of 33.33 mg Y(III) per gram of sorbent). The results showed that amounts of radio-yttrium as low as 250 μg could be extracted effectively with high radionuclidic and radiochemical purity from macro-gram amounts of strontium.

  10. Scandium versus yttrium{amino-alkoxy-bis(phenolate)} complexes for the stereoselective ring-opening polymerization of racemic lactide and β-butyrolactone.

    Science.gov (United States)

    Chapurina, Yulia; Klitzke, Joice; Casagrande, Osvaldo de L; Awada, Mouhamad; Dorcet, Vincent; Kirillov, Evgueni; Carpentier, Jean-François

    2014-10-14

    Scandium and yttrium amide complexes Ln{ONXO(R1,R2)}(N(SiHMe2)2)(THF)n (Ln = Sc, n = 0 or Y, n = 1; X = NMe2 or OMe; R(1) = Cumyl or p-Cl-Cumyl; R(2) = Me or Cumyl) were prepared by aminolysis of Ln[N(SiHMe2)2]3(THF) with the corresponding tetradentate diamino- or alkoxy-amino-bis(phenol) pro-ligands {ONXO(R1,R2)}H2. In the solid state and in toluene solution, the scandium complexes are monomeric and 5-coordinated, while the analogous yttrium complexes all bear an extra THF-coordinated molecule and are 6-coordinated. Sc{ONXO(R1,R2)}(N(SiHMe2)2) complexes are single-site initiators for the ring-opening polymerization (ROP) of racemic lactide but are less active than their yttrium analogues Y{ONXO(R1,R2)}(N(SiHMe2)2)(THF); also, in contrast to the latter ones, they are inactive in the ROP of the more demanding racemic β-butyrolactone. On the other hand, the scandium amide complexes feature a significantly improved control over the ROP of lactide, yielding PLAs with much narrower molecular weight distributions (Đ(M) < 1.1 for Sc vs. 1.5-2.0 for Y). The yttrium complex with the very bulky o,p-dicumyl-substituted ligand is more heteroselective than its scandium analogue (P(r) = 0.88 vs. 0.83), while the opposite is observed with complexes based on p-methyl-substituted ligands (P(r) = 0.50 in toluene or 0.72-0.75 in THF for Y vs. P(r) = 0.75-0.83 for Sc in toluene). These reactivity and selectivity trends are rationalized by a much more sterically crowded coordination sphere in scandium than in yttrium complexes.

  11. One-step synthesis of layered yttrium hydroxides in immiscible liquid–liquid systems: Intercalation of sterically-bulky hydrophobic organic anions and doping of europium ions

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Mebae; Fujihara, Shinobu, E-mail: shinobu@applc.keio.ac.jp

    2014-02-15

    Inorganic–organic layered rare-earth compounds were synthesized on the basis of a biphasic liquid–liquid system in one pot. Layered yttrium hydroxides (LYHs) were chosen as a host material for the intercalation of hydrophobic organic guest anions such as benzoate, sebacate, or laurate. In a typical synthesis, an organic phase dissolving carboxylic acid was placed in contact with an equal amount of an aqueous phase dissolving yttrium nitrate n-hydrate and urea. At elevated temperatures up to 80 °C, urea was hydrolyzed to release hydroxyl anions which were used to form yttrium hydroxide layers. LYHs were then precipitated with the intercalation of carboxylate anions delivered from the organic phase under the distribution law. The structure and the morphology of the LYHs could be modulated by the intercalated anions. Doped with Eu{sup 3+} ions, the LYHs exhibited red photoluminescence which was enhanced by the intercalated anions due to the antenna effect. - Graphical abstract: The Eu{sup 3+}-doped layered yttrium hydroxide exhibits intense red photoluminescence after intercalation of benzoate ions. Display Omitted - Highlights: • Immiscible biphasic liquid systems were introduced to synthesize layered yttrium hydroxides. • The temperature of the biphasic systems does not exceed 80 °C in one step of the synthesis. • Hydrophobic organic anions were intercalated between the hydroxide layers in one pot. • Structure and morphology of the hydroxides were modulated by changing the kind of organic anions. • Eu{sup 3+}-doping led to red luminescence from the hydroxides in association with the intercalated organic anions.

  12. Influence of yttrium iron garnet thickness and heater opacity on the nonlocal transport of electrically and thermally excited magnons

    Science.gov (United States)

    Shan, Juan; Cornelissen, Ludo J.; Vlietstra, Nynke; Ben Youssef, Jamal; Kuschel, Timo; Duine, Rembert A.; van Wees, Bart J.

    2016-11-01

    We studied the nonlocal transport behavior of both electrically and thermally excited magnons in yttrium iron garnet (YIG) as a function of its thickness. For electrically injected magnons, the nonlocal signals decrease monotonically as the YIG thickness increases. For the nonlocal behavior of the thermally generated magnons, or the nonlocal spin Seebeck effect (SSE), we observed a sign reversal which occurs at a certain heater-detector distance, and it is influenced by both the opacity of the YIG/heater interface and the YIG thickness. Our nonlocal SSE results can be qualitatively explained by the bulk-driven SSE mechanism together with the magnon diffusion model. Using a two-dimensional finite element model (2D-FEM), we estimated the bulk spin Seebeck coefficient of YIG at room temperature. The quantitative disagreement between the experimental and modeled results indicates more complex processes going on in addition to magnon diffusion and relaxation, especially close to the contacts.

  13. Textured tape substrates from binary copper alloys with vanadium and yttrium for the epitaxial deposition of buffer and superconducting layers

    Science.gov (United States)

    Khlebnikova, Yu. V.; Rodionov, D. P.; Egorova, L. Yu.; Suaridze, T. R.

    2016-05-01

    The structure of tapes of binary Cu-0.6 wt % V and Cu-1 wt % Y alloys and texturing process of them in the course of cold deformation by rolling to 99% and subsequent recrystallizing annealing have been studied. The possibility of achieving the perfect cube texture in thin tapes made from binary copper-based alloys with vanadium and yttrium additions has in principle been shown. This opens the prospect of using them as substrates when manufacturing tapes of second-generation high-temperature superconductors. Optimum annealing conditions for the studied alloys have been determined, which have made it possible to produce the perfect biaxial texture with a content of cube {001} ± 10° grains on the surfaces of textured tapes of more than 95%.

  14. Forming a perfect cubic texture in thin copper-yttrium alloy strips during cold rolling and annealing

    Science.gov (United States)

    Schastlivtsev, V. M.; Rodionov, D. P.; Khlebnikova, Yu. V.; Akshentsev, Yu. N.; Egorova, L. Yu.; Suaridze, T. R.

    2016-03-01

    The structure of strips produced from the Cu-1 wt % Y binary alloy using cold deformation by rolling to the degree of deformation of 99%, followed by recrystallization annealing, as well as the process of texture formation in these strips, is studied. The possibility of forming a perfect cubic texture in a thin strip made of a binary yttrium-modified copper-based alloy has been shown in principle, which opens the prospect of the use of this alloy to produce substrates for strip high-temperature superconductors of the second generation. The optimum conditions of annealing have been determined, which make it possible to form a perfect biaxial texture in the Cu-1 wt % Y alloy with a content of cubic grains {001} ± 10° on the surface of the textured strip of over 95%.

  15. Effect of Y (Yttrium) Filling Fraction on Thermoelectric Properties of p-type Yy Fex Co4-x Sb12

    Institute of Scientific and Technical Information of China (English)

    TANG Xinfeng; SONG Bo; ZHANG Qingjie

    2006-01-01

    Yttrium-filled skutterndites YyFex Co4-x Sb12 ( y= 0-0.40) were syrthesized. The effect of Y filling fraction on thermoelectric properties of YyFexCo4-xSb12 was investigated. All samples showed p-type conduct. The electrical conductivity decreased with increasing filling fraction y . The Seebeck coefficient increased with increasing temperature. The lattice thermal conductivity decreased with increasing filling fraction y and showed the minimum value at a certain filling fraction y = 0.3. The effect of different filling atoms M( M: Ba, Ce, Y) on the lattice thermal conductivity of MyFex Co4- x Sb12 was discussed. The maximum ZT value of 0.7 was obtained for Y0.08 Fe0.7 Co3.3 Sb12 at 750 K.

  16. Studies of the optical spectra and spin-Hamiltonian parameters for the trivalent ytterbium ions in lithium yttrium fluoride crystals

    Science.gov (United States)

    Feng, W. L.; Han, Z.; Zhong, Y. C.

    In this paper, the crystal field (CF) levels and spin-Hamiltonian (SH) parameters (g factors g∥ and g⊥ and hyperfine structure constants A∥ and A⊥) of the rare-earth ion Yb3+ in lithium yttrium fluoride crystals are calculated under D2d point symmetry assumption. Two main methods are used in the calculation to study the SH parameters: one is the perturbation theory method and the other is the complete diagonalization (energy matrix) method (CDM). Comparing the calculated results with the experimental data, we can see that the CDM is more effective to calculate the SH parameters. In addition, the CF J-mixing of all excited-state multiplets into the ground-state multiplet 2F7/2 is considered. The validity of the calculated results is discussed.

  17. Hereditary haemorrhagic telangiectasia treated by pulsed neodymium:yttrium-aluminium-garnet (Nd:YAG) laser (1,064 nm).

    Science.gov (United States)

    Werner, A; Bäumler, W; Zietz, S; Kühnel, T; Hohenleutner, U; Landthaler, M

    2008-10-01

    Hereditary haemorrhagic telangiectasia (HHT) is a familial, autosomal, dominant, multi-system, vascular, dysplasia. Besides repetitive epistaxis, cutaneous eruptive macules and nodules lead to recurring bleeding and cosmetic problems. We report on a pilot study of four cases of HHT in which cutaneous lesions were treated with a pulsed neodymium:yttrium-aluminum-garnet (Nd:YAG) laser (1,064 nm). Pulsed Nd:YAG laser treatment, without anaesthesia, was performed several times on eruptive angiomas on palmar and facial skin. Lesions on fingers and face mostly showed very good, or even complete, clearing after the first laser treatment. Several macules required multiple treatment; only a few lesions showed no effect. Pulsed Nd:YAG laser therapy (1,064 nm) appears to be an effective and safe treatment option for hereditary haemorrhagic telangiectasia on the skin of face and extremities.

  18. From electrocautery, balloon dilatation, neodymium-doped:yttrium-aluminum-garnet (Nd:YAG) laser to argon plasma coagulation and cryotherapy

    Science.gov (United States)

    Pickering, Edward M.; Lee, Hans J.

    2015-01-01

    Over the past decade, there has been significant advancement in the development/application of therapeutics in thoracic diseases. Ablation methods using heat or cold energy in the airway is safe and effective for treating complex airway disorders including malignant and non-malignant central airway obstruction (CAO) without limiting the impact of future definitive therapy. Timely and efficient use of endobronchial ablative therapies combined with mechanical debridement or stent placement results in immediate relief of dyspnea for CAO. Therapeutic modalities reviewed in this article including electrocautery, balloon dilation (BD), neodymium-doped:yttrium-aluminum-garnet (Nd:YAG) laser, argon plasma coagulation (APC), and cryotherapy are often combined to achieve the desired results. This review aims to provide a clinically oriented review of these technologies in the modern era of interventional pulmonology (IP). PMID:26807284

  19. Brillouin light scattering study of transverse mode coupling in confined yttrium iron garnet/barium strontium titanate multiferroic

    Energy Technology Data Exchange (ETDEWEB)

    Sadovnikov, A. V., E-mail: sadovnikovav@gmail.com; Nikitov, S. A. [Laboratory “Metamaterials,” Saratov State University, Saratov 410012 (Russian Federation); Kotel' nikov Institute of Radioengineering and Electronics, Russian Academy of Sciences, Moscow 125009 (Russian Federation); Beginin, E. N.; Bublikov, K. V.; Grishin, S. V.; Sheshukova, S. E.; Sharaevskii, Yu. P. [Laboratory “Metamaterials,” Saratov State University, Saratov 410012 (Russian Federation)

    2015-11-28

    Using the space-resolved Brillouin light scattering spectroscopy we study the transformation of dynamic magnetization patterns in a bilayer multiferroic structure. We show that in the comparison with a single yttrium iron garnet (YIG) film magnetization distribution is transformed in the bilayer structure due to the coupling of waves propagating both in an YIG film (magnetic layer) and in a barium strontium titanate slab (ferroelectric layer). We present a simple electrodynamic model using the numerical finite element method to show the transformation of eigenmode spectrum of confined multiferroic. In particular, we demonstrate that the control over the dynamic magnetization and the transformation of spatial profiles of transverse modes in magnetic film of the bilayer structure can be performed by the tuning of the wavevectors of transverse modes. The studied confined multiferroic stripe can be utilized for fabrication of integrated dual tunable functional devices for magnonic applications.

  20. Reflection and Transmission Coefficient of Yttrium Iron Garnet Filled Polyvinylidene Fluoride Composite Using Rectangular Waveguide at Microwave Frequencies

    Science.gov (United States)

    Soleimani, Hassan; Abbas, Zulkifly; Yahya, Noorhana; Shameli, Kamyar; Soleimani, Hojjatollah; Shabanzadeh, Parvaneh

    2012-01-01

    The sol-gel method was carried out to synthesize nanosized Yttrium Iron Garnet (YIG). The nanomaterials with ferrite structure were heat-treated at different temperatures from 500 to 1000 °C. The phase identification, morphology and functional groups of the prepared samples were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. The YIG ferrite nanopowder was composited with polyvinylidene fluoride (PVDF) by a solution casting method. The magnitudes of reflection and transmission coefficients of PVDF/YIG containing 6, 10 and 13% YIG, respectively, were measured using rectangular waveguide in conjunction with a microwave vector network analyzer (VNA) in X-band frequencies. The results indicate that the presence of YIG in polymer composites causes an increase in reflection coefficient and decrease in transmission coefficient of the polymer. PMID:22942718

  1. Non-Target Activity Detection by Post-Radioembolization Yttrium-90 PET/CT: Image Assessment Technique and Case Examples.

    Science.gov (United States)

    Kao, Yung Hsiang; Tan, Andrew E H; Lo, Richard H G; Tay, Kiang Hiong; Tan, Bien Soo; Chow, Pierce K H; Ng, David C E; Goh, Anthony S W

    2014-01-01

    High resolution yttrium-90 ((90)Y) imaging of post-radioembolization microsphere biodistribution may be achieved by conventional positron emission tomography with integrated computed tomography (PET/CT) scanners that have time-of-flight capability. However, reconstructed (90)Y PET/CT images have high background noise, making non-target activity detection technically challenging. This educational article describes our image assessment technique for non-target activity detection by (90)Y PET/CT, which qualitatively overcomes the problem of background noise. We present selected case examples of non-target activity in untargeted liver, stomach, gallbladder, chest wall, and kidney, supported by angiography and (90)Y bremsstrahlung single-photon emission computed tomography with integrated computed tomography (SPECT/CT) or technetium-99m macroaggregated albumin SPECT/CT.

  2. Non-target activity detection by post-radioembolization yttrium-90 PET/CT: Image assessment technique and case examples

    Directory of Open Access Journals (Sweden)

    Yung Hsiang eKao

    2014-02-01

    Full Text Available High-resolution yttrium-90 (90Y imaging of post-radioembolization microsphere biodistribution may be achieved by conventional positron emission tomography with integrated computed tomography (PET/CT scanners that have time-of-flight capability. However, reconstructed 90Y PET/CT images have high background noise, making non-target activity detection technically challenging. This educational article describes our image assessment technique for non-target activity detection by 90Y PET/CT which qualitatively overcomes the problem of background noise. We present selected case examples of non-target activity in untargeted liver, stomach, gallbladder, chest wall and kidney, supported by angiography and 90Y bremsstrahlung single photon emission computed tomography with integrated computed tomography (SPECT/CT or technetium-99m macroaggregated albumin SPECT/CT.

  3. 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.

  4. High index of refraction via quantum interference in a three- level system of Er3+-doped yttrium aluminium garnet crystal

    Institute of Scientific and Technical Information of China (English)

    He Qiong-Yi; Wang Tie-Jun; Gao Jin-Yue

    2006-01-01

    A simple three-level system is proposed to produce high index of refraction with zero absorption in an Er3+-doped yttrium aluminium garnet (YAG) crystal, which is achieved for a probe field between the excited state 4Ⅰ13/2 and ground state 4Ⅰ15/2 by adjusting a strong coherent driving field between the upper excited state 4Ⅰ11/2 and 4Ⅰ15/2· It is found that the changes of the frequency of the coherent driving field and the concentration of Er3+ ions in the YAG crystal can maximize the index of refraction accompanied by vanishing absorption. This result could be useful for the dispersion compensation in fibre communication, laser particle acceleration, high precision magnetometry and so on.

  5. 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.

  6. Reflection and transmission coefficient of yttrium iron garnet filled polyvinylidene fluoride composite using rectangular waveguide at microwave frequencies.

    Science.gov (United States)

    Soleimani, Hassan; Abbas, Zulkifly; Yahya, Noorhana; Shameli, Kamyar; Soleimani, Hojjatollah; Shabanzadeh, Parvaneh

    2012-01-01

    The sol-gel method was carried out to synthesize nanosized Yttrium Iron Garnet (YIG). The nanomaterials with ferrite structure were heat-treated at different temperatures from 500 to 1000 °C. The phase identification, morphology and functional groups of the prepared samples were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. The YIG ferrite nanopowder was composited with polyvinylidene fluoride (PVDF) by a solution casting method. The magnitudes of reflection and transmission coefficients of PVDF/YIG containing 6, 10 and 13% YIG, respectively, were measured using rectangular waveguide in conjunction with a microwave vector network analyzer (VNA) in X-band frequencies. The results indicate that the presence of YIG in polymer composites causes an increase in reflection coefficient and decrease in transmission coefficient of the polymer.

  7. High-efficiency Tm-doped yttrium aluminum garnet laser pumped with a wavelength-locked laser diode

    Science.gov (United States)

    Huang, H. Z.; Huang, J. H.; Liu, H. G.; Dai, S. T.; Weng, W.; Zheng, H.; Ge, Y.; Li, J. H.; Deng, J.; Yang, X.; Lin, W. X.

    2016-09-01

    We first demonstrate a high-efficiency composite Tm-doped yttrium aluminum garnet laser end-pumped with a narrow-linewidth laser diode, which was locked at a wavelength of 784.9 nm with volume Bragg gratings. The locked pump wavelength was experimentally determined by the excitation peak, which was also the absorption peak of a 3.5 at.% Tm:YAG crystal around 785 nm, for the improvement of laser efficiency under high-intensity pumping. Under an absorbed pump power of 24.64 W, a maximum output power of 11.12 W at 2018 nm was obtained, corresponding to an optical to optical conversion efficiency of 45.1% and a slope efficiency of 52.4%.

  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. Mode-locking optimization with a real-time feedback system in a Nd:yttrium lithium fluoride laser cavity

    Science.gov (United States)

    Marengoni, C.; Canova, F.; Batani, D.; Benocci, R.; Librizzi, M.; Narayanan, V.; Gomareschi, M.; Lucchini, G.; Kilpio, A.; Shashkov, E.; Stuchebrukhov, I.; Vovchenko, V.; Chernomyrdin, V.; Krasuyk, I.; Hall, T.; Bittanti, S.

    2007-01-01

    We present a control system, which allows an automatic optimization of the pulse train stability in a mode-locked laser cavity. In order to obtain real-time corrections, we chose a closed loop approach. The control variable is the cavity length, mechanically adjusted by gear system acting on the rear cavity mirror, and the controlled variable is the envelope modulation of the mode-locked pulse train. Such automatic control system maintains the amplitude of the mode-locking pulse train stable within a few percent rms during the working time of the laser. Full implementation of the system on an Nd:yttrium lithium fluoride actively mode-locked laser is presented.

  10. Co-doping TiO{sub 2} with boron and/or yttrium elements: Effects on antimicrobial activity

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuzheng [School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870 (China); Wu, Yusheng, E-mail: henanwys@sina.com [School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870 (China); Yang, He; Xue, Xiangxin; Liu, Zhihua [Institute of Metallurgical Resources and Environmental Engineering, Northeastern University, Shenyang 110819 (China)

    2016-09-15

    Highlights: • B-Y/TiO{sub 2} nano materials firstly applied to the fields of antibacterial materials. • Systems analysis the existence state of boron and yttrium ion in TiO{sub 2}. • Doping B and Y greatly strengthened the antibacterial activity of TiO{sub 2}. - Abstract: Pure TiO{sub 2}, boron and/or yttrium doped TiO{sub 2} nano-materials were synthesized by a sol–gel method and characterized by XRD, SEM, XPS and PL. XRD analysis indicates that, in the pure TiO{sub 2} and B single doped TiO{sub 2} (B-TiO{sub 2}) nano-materials calcinated at 700 °C, the presence of TiO{sub 2} is a mixture of anatase and rutile; in the Y single doped (Y-TiO{sub 2}), B and Y co-doped TiO{sub 2} nano-materials (B/Y-TiO{sub 2}), the presence of TiO{sub 2} is anatase. SEM image shows the prepared materials have a common round morphology and hexagonal plate morphology caused by the agglomeration of particles. Boron atoms are partially embedded into the TiO{sub 2} interstitial structure or incorporated into the TiO{sub 2} lattice through occupying the position of the oxygen atoms. The results of antimicrobial experiment show that B/Y-TiO{sub 2} material has a remarkable antimicrobial activity. Compared with the visible light irradiation, antimicrobial activity of B/Y-TiO{sub 2} in dark is significant poor.

  11. Phase control of yttrium (Y)-doped TiO{sub 2} nanofibers and intensive visible photoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Koppala Siva; Song, Chan-Geun; Bak, Geon Myeon [Department of Advanced Materials Science and Engineering, Dankook University, Cheonan, Chungnam 330-714 (Korea, Republic of); Heo, Gaeun; Seong, Maeng-Je [Department of Physics, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Yoon, Jong-Won, E-mail: jwyoon@dankook.ac.kr [Department of Advanced Materials Science and Engineering, Dankook University, Cheonan, Chungnam 330-714 (Korea, Republic of)

    2014-12-25

    Highlights: • Yttrium (Y)-doped TiO{sub 2} nanofibers were successfully fabricated by electrospinning. • The incorporation of Y into TiO{sub 2} facilitates the anatase phase growth. • The optical band gap energy increased with Y-doping. • Y-doped TiO{sub 2} nanofibers PL intensity enormously increased due to defect-related centers on the surface. - Abstract: Yttrium (Y)-doped TiO{sub 2} nanofibers were successfully fabricated by electrospinning and the subsequent calcination of the as-spun nanofibers. The X-ray diffraction and Raman scattering results showed that the incorporation of Y into TiO{sub 2} impedes the rutile-phase growth, facilitates the anatase phase growth. Estimated grain sizes are reduced from 15.71 nm to 8.8 nm with increasing Y-doping concentration. Raman scattering studies confirm the existence of slight brookite phase in case of Y-doped TiO{sub 2} nanofibers. Field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) images revealed that the nanofibers comprised of nanoparticles and that Y-doping reduced the nanoparticle size. The optical band gap energy increased with increasing Y-doping, which can be ascribed to both quantum confinement effect and pure anatase phase transformation from mixed rutile-anatase phase. Y-doping induced a blue-shift of the broad visible photoluminescence (PL) peak and an increase of PL intensity with the concurrent decrease grain size. For 3 at.% Y-doped TiO{sub 2} nanofibers PL intensity enormously increased due to defect-related centers on the surface.

  12. In situ hydrothermal crystallization of hexagonal hydroxyapatite tubes from yttrium ion-doped hydroxyapatite by the Kirkendall effect

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chengfeng, E-mail: cfli@sdut.edu.cn [School of Materials Science and Engineering, Shandong University of Technology, 255049 Shandong (China); Ge, Xiaolu [School of Science, Shandong University of Technology, 255049 Shandong (China); Li, Guochang; Lu, Hao; Ding, Rui [School of Materials Science and Engineering, Shandong University of Technology, 255049 Shandong (China)

    2014-12-01

    An in situ hydrothermal crystallization method with presence of glutamic acid, urea and yttrium ions was employed to fabricate hexagonal hydroxyapatite (HAp, Ca{sub 5}(PO{sub 4}){sub 3}(OH)) tubes with length of 200 nm–1 μm. Firstly, yttrium ion-doped HAp (Y-HAp, Ca{sub 5−x}Y{sub x}(PO{sub 4}){sub 3}(OH)) was synthesized after hydrolysis of urea and HPO{sub 4}{sup 2−} ions at 100 °C with a dwell time of 24 h. The shift of X-ray diffraction peaks of HAp to high angle was caused the substitution of Ca{sup 2+} ions by small-sized Y{sup 3+} ions. At 160 °C, further hydrolysis reactions of urea and HPO{sub 4}{sup 2−} ions resulted in the generation of ample OH{sup −} and PO{sub 4}{sup 3−} ions, which provided a high chemical potential for the dissolution of Y-HAp and recrystallization of HAp and YPO{sub 4}. Finally, HAp tubes were formed in situ on Y-HAp according to the Kirkendall effect as a result of the difference of diffusion rate of cations (Ca{sup 2+} ions, outward and slow) and anions (OH{sup −} and PO{sub 4}{sup 3−} ions, inward and fast). The formation process of HAp tube was simulated by the encapsulation of fluorescein molecules in precipitates. Photoluminescence properties were enhanced for HAp tubes with thick and dense walls. This novel tubular material could find wide applications as carriers of drugs, dyes and catalysts. - Highlights: • Hexagonal HAp tubes with adjustable sizes are prepared by a hydrothermal method. • A dissolution-recrystallization process occurs during hydrothermal treatment. • The formation mechanism is explained by the Kirkendall effect. • The crystallization is simulated by the encapsulation and release of fluorescein.

  13. Utilization of microspheres labelled with yttrium 90 in the treatment of principally primitive hepatic tumors: about 30 cases;Utilisation des microspheres marquees a l'yttrium 90 dans le traitement des tumeurs hepatiques principalement primitives: a propos de 30 cas

    Energy Technology Data Exchange (ETDEWEB)

    Garin, E.; Lenoir, L.; Ardisson, V. [CRLCC centre Eugene-Marquis, Service de medecine nucleaire, 35 - Rennes (France); Rolland, Y. [CRLCC centre Eugene-Marquis, Service de radiologie, 35 - Rennes (France); Latrournerie, M.; Boucher, E.; Raoul, J.L. [CRLCC centre Eugene-Marquis, Service d' oncologie digestive, 35 - Rennes (France)

    2010-05-15

    The use of microspheres labelled with yttrium 90 (theraspheres) is an interesting therapy approach in the liver tumours because of a low exposure and a promising response rate or stabilization. The use of SPECT/CT acquisition brings an important help to the therapy planning. (N.C.)

  14. Singular value decomposition approach to the yttrium occurrence in mineral maps of rare earth element ores using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Romppanen, Sari; Häkkänen, Heikki; Kaski, Saara

    2017-08-01

    Laser-induced breakdown spectroscopy (LIBS) has been used in analysis of rare earth element (REE) ores from the geological formation of Norra Kärr Alkaline Complex in southern Sweden. Yttrium has been detected in eudialyte (Na15 Ca6(Fe,Mn)3 Zr3Si(Si25O73)(O,OH,H2O)3 (OH,Cl)2) and catapleiite (Ca/Na2ZrSi3O9·2H2O). Singular value decomposition (SVD) has been employed in classification of the minerals in the rock samples and maps representing the mineralogy in the sampled area have been constructed. Based on the SVD classification the percentage of the yttrium-bearing ore minerals can be calculated even in fine-grained rock samples.

  15. Multimodal Therapy including Yttrium-90 Radioembolization as a Bridging Therapy to Liver Transplantation for a Huge and Locally Advanced Intrahepatic Cholangiocarcinoma.

    Science.gov (United States)

    Rayar, Michel; Levi Sandri, Giovanni Battista; Houssel-Debry, Pauline; Camus, Christophe; Sulpice, Laurent; Boudjema, Karim

    2016-09-01

    Treatment of intrahepatic cholangiocarcinoma remains a major challenge. For an unresectable lesion without extrahepatic spread, liver transplantation could be a potential solution but it is still associated with poor oncologic results owing to the absence of effective neoadjuvant treatment. We report the case of a young man with locally advanced intrahepatic cholangiocarcinoma presenting with multiple intrahepatic metastases and vascular structure involvement. The lesion was significantly downstaged by a multimodal therapy including intra-arterial Yttrium-90 radioembolization, systemic chemotherapy and external radiotherapy, allowing liver transplantation. Three years after the procedure, oncologic outcome is excellent with no sign of recurrence. Multimodal therapy including Yttrium-90 radioembolization could be relevant as neoadjuvant treatment before liver transplantation for unresectable intrahepatic cholangiocarcinoma.

  16. SU-E-T-189: First Experimental Verification of the Accuracy of Absolute Dose Reconstruction From PET-CT Imaging of Yttrium 90 Microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Veltchev, I; Fourkal, E; Doss, M; Ma, C; Meyer, J; Yu, M; Horwitz, E [Fox Chase Cancer Center, Philadelphia, PA (United States)

    2014-06-01

    Purpose: In the past few years there have been numerous proposals for 3D dose reconstruction from the PET-CT imaging of patients undergoing radioembolization treatment of the liver with yttrium-90 microspheres. One of the most promising techniques uses convolution of the measured PET activity distribution with a pre-calculated Monte Carlo dose deposition kernel. The goal of the present study is to experimentally verify the accuracy of this method and to analyze the significance of various error sources. Methods: Optically stimulated luminescence detectors (OSLD) were used (NanoDot, Landauer) in this experiment. Two detectors were mounted on the central axis of a cylinder filled with water solution of yttrium-90 chloride. The total initial activity was 90mCi. The cylinder was inserted in a larger water phantom and scanned on a Siemens Biograph 16 Truepoint PET-CT scanner. Scans were performed daily over a period of 20 days to build a calibration curve for the measured absolute activity spanning 7 yttrium-90 half-lives. The OSLDs were mounted in the phantom for a predetermined period of time in order to record 2Gy dose. The measured dose was then compared to the dose reconstructed from the activity density at the location of each dosimeter. Results: Thorough error analysis of the dose reconstruction algorithm takes into account the uncertainties in the absolute PET activity, branching ratios, and nonlinearity of the calibration curve. The measured dose for 105-minute exposure on day 10 of the experiment was 219(11)cGy, while the reconstructed dose at the location of the detector was 215(47)cGy. Conclusion: We present the first experimental verification of the accuracy of the convolution algorithm for absolute dose reconstruction of yttrium-90 microspheres. The excellent agreement between the measured and calculated point doses will encourage the broad clinical adoption of the convolution-based dose reconstruction algorithm, making future quantitative dose

  17. The effect of erbium-doped: yttrium, aluminium and garnet laser irradiation on the surface microstructure and roughness of double acid-etched implants

    OpenAIRE

    2011-01-01

    Purpose One of the most frequent complications related to dental implants is peri-implantitis, and the characteristics of implant surfaces are closely related to the progression and resolution of inflammation. Therefore, a technical modality that can effectively detoxify the implant surface without modification to the surface is needed. The purpose of this study was to evaluate the effect of erbium-doped: yttrium, aluminium and garnet (Er:YAG) laser irradiation on the microstructural changes ...

  18. Observation of multiple-harmonic radiation induced from a gold surface by picosecond neodymium-doped yttrium aluminum garnet laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Farkas, G.; Toth, C. (Research Institute for Solid-State Physics, P.O. Box 49, H-1525 Budapest (Hungary)); Moustaizis, S.D.; Papadogiannis, N.A.; Fotakis, C. (Foundation for Research and Technology, Hellas, P.O. Box 1527, Heraklion 711 10, Crete (Greece))

    1992-10-01

    Illuminating a gold surface by strong (5 GW/cm{sup 2}) picosecond neodymium-doped yttrium aluminum garnet laser pulses at grazing incidence, we observed a generation of coherent beams of both even and odd harmonics up to fifth order in the reflected direction with efficiencies 10{sup {minus}10--}10{sup {minus}13}. The observed decrease of the harmonic efficiencies with increasing harmonic order is much weaker than predicted by perturbative theories.

  19. Laser-Induced Forward Transfer-printing of focused ion beam pre-machined crystalline magneto-optic yttrium iron garnet micro-discs.

    Science.gov (United States)

    Sones, C L; Feinaeugle, M; Sposito, A; Gholipour, B; Eason, R W

    2012-07-02

    We present femtosecond laser-induced forward transfer of focused ion beam pre-machined discs of crystalline magneto-optic yttrium iron garnet (YIG) films. Debris-free circular micro-discs with smooth edges and surface uniformity have been successfully printed. The crystalline nature of the printed micro-discs has not been altered by the LIFT printing process, as was confirmed via micro-Raman measurements.

  20. Promotional effects of cerium doping and NOx on the catalytic soot combustion over MnMgAlO hydrotalcite-based mixed oxides

    Institute of Scientific and Technical Information of China (English)

    李倩; 王晓; 常伟; 陈慧; 张昭良

    2014-01-01

    A series of MnMgAlO samples with different amounts of Ce doping were facilely prepared using coprecipitation method and their catalytic soot combustion activity was evaluated by temperature programmed oxidation reaction (TPO). The methods of X-ray diffraction (XRD), Brumauer-Emmett-Teller (BET), H2-TPR, NO-TPO and in situ IR were used to characterize the physio-chemical properties of these samples. Dopant Ce improved the soot combustion performance of MnMgAlO catalyst due to the en-hanced redox ability. Introduction of NOx led to the further increase of catalytic soot oxidation activity on these samples. Over Ce-containing samples, the catalytic activity was slightly decreased as the amount of dopant Ce increased in O2. Differently, in NO+O2, a certain amount of dopant Ce was much more favorable and excess amount of Ce resulted in a sharp drop of the catalytic soot combustion activity. Both NO2 and nitrates were found to have great contributions to the effects of NOx on the soot combustion activity of Ce-doped catalysts. More NO2 was generated as dopant Ce increased. When appropriate amount of Ce was introduced, the as-formed NO2 was stored as bridging bidentate nitrate on Mn-Ce site, which was confirmed to have higher reactivity with soot than nitrite or monodentate nitrate on Mn and/or Ce sites. Overall, Mn0.5Mg2.5Ce0.1Al0.9O was considered as the most potential catalyst for soot combustion.

  1. Photocatalytic activity of cerium-doped mesoporous TiO2 coated Fe3O4magnetic composite under UV and visible light

    Institute of Scientific and Technical Information of China (English)

    SHI Zhongliang; YANG Xingman; YAO Shuhua

    2012-01-01

    A novel kind of magnetically separable photocatalyst of cerrium-doped mesoporous titanium dioxide coated magnetite (Ce/MTiO2/Fe3O4) was prepared and its activities under UV and visible light were reported.The catalysts with Ce/MTiO2 shell and Fe3O4 core were prepared by coating photoactive Ce/MTiO2 onto a magnetic Fe3O4 core through the hydrolysis of tetrabutyltitanate (Ti(OBu)4,TBT) with precursors of ammonium ceric nitrate and TBT in the presence of Fe3O4 particles.The MTiO2 shell was for photocatalysis,the Fe3O4 core was for separation by the magnetic field and the doped Ce was used to enhance the photocatalytic activity of MTiO2.The morphological,structural and optical properties of the prepared samples were characterized by Brunauer-Emmett-Teller (BET) surface area,transmission electron microscopy (TEM),X-ray diffraction (XRD) and UV-vis absorption spectroscopy.The effect of cerrium-doped content on the photocatalytic activity was studied and the result revealed that 0.5 mol.% Ce/MTiO2/Fe3O4 exhibited highest photoactivity.The photocatalytic activities of obtained photocatalysts under UV and visible light were estimated by measuring the degradation rate of methylene blue (MB,50 mg/L) in an aqueous solution.The results showed that the prepared photocatalyst was activated by visible light and used as effective catalyst in photooxidation reactions.In addition,the possibility of cyclic usage of the prepared photocatalyst was also confirmed.Moreover,Ce/MTiO2 was tightly bound to Fe3O4 and could be easily recovered from the medium by an external magnetic filed.So,the photocatalyst can be reused without any mass loss.It can therefore be potentially applied for the treatment of water contaminated by organic pollutants.

  2. Magnetoresistive properties of cerium doped La{sub 0.7}Ca{sub 0.3}MnO{sub 3} manganites

    Energy Technology Data Exchange (ETDEWEB)

    Chihoub, R. [NDT Lab, Faculty of Science and Technology, Mohammed Seddik Benyahia University, Jijel 18000 (Algeria); Physics Department, Faculty of Arts and Sciences, Abbant Izzet Baysal University, Bolu 14280 (Turkey); Amira, A., E-mail: amira@univ-jijel.dz [NDT Lab, Faculty of Science and Technology, Mohammed Seddik Benyahia University, Jijel 18000 (Algeria); Mahamdioua, N. [NDT Lab, Faculty of Science and Technology, Mohammed Seddik Benyahia University, Jijel 18000 (Algeria); Altintas, S.P.; Varilci, A.; Terzioglu, C. [Physics Department, Faculty of Arts and Sciences, Abbant Izzet Baysal University, Bolu 14280 (Turkey)

    2016-07-01

    In this work, the effect of doping by tetravalent Ce{sup 4+}on the structural and magnetoresistive properties of La{sub 0.7−x}Ce{sub x}Ca{sub 0.3}MnO{sub 3} polycrystalline manganites is presented. Samples with x=0, 0.1, 0.2 and 0.3 are prepared by solid state reaction method and characterized. For all doping levels, the X ray diffraction (XRD) analysis shows that the doping element is not completely soluble in the manganite. The cell parameters values, which decrease with Ce content, are refined in the orthorhombic system by taking into account the unreacted CeO{sub 2} phase. The observation by scanning electron microscopy (SEM) reveals a change in the morphology of the grains and the porosity of the samples by doping. The temperature dependence of magnetization curves shows a transition from paramagnetic to ferromagnetic state in all samples. A decrease of the Curie temperature T{sub c} with doping is revealed. The resistivity of the samples increases with Ce content and shows a clear metal to insulator transition when measured as a function of temperature. The doping also decreases the temperature T{sub p} of this transition, in accordance with the evolution of T{sub c} values. The calculated magnetoresistance (MR) for a magnetic field of 5T increases gradually from 39.52% for x=0 to 66.18% for x=0.3.

  3. Effects of Cerium Doping at Ti Sites and Europium Doping at Ba Sites on Dielectric Properties of BaTiO3 Ceramics

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Two special rare earth elements cerium and europium were chosen to conduct chemical modification of the BaTiO3 structure. The cold-pressing ceramic processing technique was used to prepare barium titanate ceramics doped with Ce at Ti sites and with Eu at Ba sites on the base of formulas Ba(Ti1-xCex)O3(x=0.05, 0.10)(CBT) and(Ba1-yEuy)Ti1-y/8O3(y=0.05, 0.10)(EBT). Associated with structures and microstructures, the effects of cerium and europium doping on dielectric properties of BaTiO3 ceramics were discussed. The CBT ceramics exhibit a pseudo-cubic perovskite structure, while the EBT ceramics exhibit a tetragonal perovskite structure with the exception of the existence of a small percentage of the Eu2Ti2O7 phase. The Curie peak of BaTiO3 shifts towards room temperature at rates of 3 ℃/mol Ce atoms and 10 ℃/mol Eu atoms(Eu≤5%), respectively. Compared with the CBT ceramics, the EBT ceramics show significant advantages, such as a narrow fine grain size distribution(1 μm), a lower porosity and a higher density(5.85 g/cm3), more stable dielectric-temperature dependence(ε'=1600-1800 at t<50 ℃) and a lower dissipation factor(<0.05). The stability of dielectric constant with frequency in BaTiO3 can extend to 107 Hz due to Ce and Eu doping.

  4. Study on cerium-doped nano-TiO2 coatings for corrosion protection of 316 L stainless steel.

    Science.gov (United States)

    Li, Suning; Wang, Qian; Chen, Tao; Zhou, Zhihua; Wang, Ying; Fu, Jiajun

    2012-04-19

    Many methods have been reported on improving the photogenerated cathodic protection of nano-TiO2 coatings for metals. In this work, nano-TiO2 coatings doped with cerium nitrate have been developed by sol-gel method for corrosion protection of 316 L stainless steel. Surface morphology, structure, and properties of the prepared coatings were investigated by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. The corrosion protection performance of the prepared coatings was evaluated in 3 wt% NaCl solution by using electrochemical techniques in the presence and absence of simulated sunlight illumination. The results indicated that the 1.2% Ce-TiO2 coating with three layers exhibited an excellent photogenerated cathodic protection under illumination attributed to the higher separation efficiency of electron-hole pairs and higher photoelectric conversion efficiency. The results also showed that after doping with an appropriate concentration of cerium nitrate, the anti-corrosion performance of the TiO2 coating was improved even without irradiation due to the self-healing property of cerium ions.

  5. Magnetic evolution of itinerant ferromagnetism and interlayer antiferromagnetism in cerium doped LaCo{sub 2}P{sub 2} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Yong; Kong, Yixiu; Liu, Kai; Zhang, Anmin [Department of Physics, Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872 (China); He, Rui [Department of Physics, University of Northern Iowa, Cedar Falls, Iowa 50614 (United States); Zhang, Qingming, E-mail: qmzhang@ruc.edu.cn [Department of Physics, Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872 (China)

    2017-05-01

    ThCr{sub 2}Si{sub 2}-type phosphide ACo{sub 2}P{sub 2} (A=Eu, La, Pr, Nd, Ce) has the same structure as iron arsenides, but their magnetic behaviors are quite distinct. In this paper, we grew a series of La{sub 1−x}Ce{sub x}Co{sub 2}P{sub 2} single crystals (x=0.0 to1.0), made structural and magnetic characterizations. We found the introduction of cerium induces a rapid decrease of c-axis and a change from ferromagnetic to antiferromagnetic states. Compared to other trivalent doped compounds, the enhancement of ferromagnetism with doping is suppressed and the transition from ferromagnetism to antiferromagnetism appear earlier. By employing first-principles band-structure calculations, we identify the increase of Ce valence suppress the itinerant ferromagnetism and leading to formation of P-P bonding with the shortening of c-axis. The bonding effectively drives an increase of interlayer antiferromagnetic interaction, eventually leads to antiferromagnetic ordering of cobalt in high-doping region.

  6. Luminescence properties of cerium-doped di-strontium magnesium di-silicate phosphor by the solid-state reaction method

    Science.gov (United States)

    Prasad Sahu, Ishwar

    2016-05-01

    A series of Sr2MgSi2O7:xCe3+ (x = 1.0%, 2.0%, 3.0%, 4.0% and 5.0%) phosphors were synthesized by the solid-state reaction method. The phosphor with optimum thermoluminescence, photoluminescence and mechanoluminescence (ML) intensity was characterized by X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and Fourier transform infrared techniques. The trapping parameters (i.e. activation energy, frequency factor and order of the kinetics) of each synthesized phosphor have been calculated using the peak shape method and the results have been discussed. Under ultraviolet excitation (325 nm), Sr2MgSi2O7:xCe3+ phosphors were composed of a broad band peaking at 385 nm, belonging to the broad emission band which emits violet-blue color. Commission International de I'Eclairage coordinates have been calculated for each sample and their overall emission is near violet-blue light. In order to investigate the suitability of the samples for industrial uses, color purity and color rendering index were calculated. An ML intensity of optimum [Sr2MgSi2O7:Ce3+ (3.0%)] phosphor increases linearly with increasing impact velocity of the moving piston which suggests that these phosphors can be used as fracto-ML-based devices. The time of the peak ML intensity and the decay rate did not change significantly with respect to increasing impact velocity of the moving piston.

  7. Effect of Mg$^{2+}$ ions co-doping on timing performance and radiation tolerance of Cerium doped Gd$_{3}$Al$_{2}$Ga$_{3}$O$_{12}$ crystals

    CERN Document Server

    Lucchini, M.T.; Bohacek, P.; Gundacker, S.; Kamada, K.; Nikl, M.; Petrosyan, A.; Yoshikawa, A.; Auffray, E.

    2016-01-01

    Inorganic scintillators with high density and high light yield are of major interest for applications in medical imaging and high energy physics detectors. In this work, the optical and scintillation properties of Mg co-doped Ce:Gd3Al2Ga3O12 crystals, grown using Czochralski technique, have been investigated and compared with Ce:Gd3Al2Ga3O12 ones prepared with identical technology. Improvements in the timing performance of the Mg co-doped samples with respect to Ce:Gd3Al2Ga3O12 ones have been measured, namely a substantial shortening of the rise time and scintillation decay components and lower afterglow were achieved. In particular, a significantly better coincidence time resolution of 233 ps FWHM, being a fundamental parameter for TOF-PET devices, has been observed in Mg co-doped crystals. The samples have also shown a good radiation tolerance under high doses of γ-rays, making them suitable candidates for applications in harsh radiation environments, such as detectors at future collider experiments.

  8. Intervalence charge transfer luminescence: The anomalous luminescence of cerium-doped Cs{sub 2}LiLuCl{sub 6} elpasolite

    Energy Technology Data Exchange (ETDEWEB)

    Seijo, Luis [Departamento de Química, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Instituto Universitario de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Barandiarán, Zoila [Instituto Universitario de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid (Spain)

    2014-12-07

    The existence of intervalence charge transfer (IVCT) luminescence is reported. It is shown that the so called anomalous luminescence of Ce-doped elpasolite Cs{sub 2}LiLuCl{sub 6}, which is characterized mainly by a very large Stokes shift and a very large band width, corresponds to an IVCT emission that takes place in Ce{sup 3+}–Ce{sup 4+} pairs, from the 5de{sub g} orbital of Ce{sup 3+} to 4f orbitals of Ce{sup 4+}. Its Stokes shift is the sum of the large reorganization energies of the Ce{sup 4+} and Ce{sup 3+} centers formed after the fixed-nuclei electron transfer and it is equal to the energy of the IVCT absorption commonly found in mixed-valence compounds, which is predicted to exist in this material and to be slightly larger than 10 000 cm{sup −1}. The large band width is the consequence of the large offset between the minima of the Ce{sup 3+}–Ce{sup 4+} and Ce{sup 4+}–Ce{sup 3+} pairs along the electron transfer reaction coordinate. This offset is approximately 2√(3) times the difference of Ce–Cl equilibrium distances in the Ce{sup 3+} and Ce{sup 4+} centers. It is shown that the energies of the peaks and the widths of IVCT absorption and emission bands can be calculated ab initio with reasonable accuracy from diabatic energy surfaces of the ground and excited states and that these can be obtained, in turn, from independent calculations on the donor and acceptor active centers. We obtained the energies of the Ce{sup 3+} and Ce{sup 4+} active centers of Ce-doped Cs{sub 2}LiLuCl{sub 6} by means of state-of-the-art wave-function-theory spin-orbit coupling relativistic calculations on the donor cluster (CeCl{sub 6}Li{sub 6}Cs{sub 8}){sup 11+} and the acceptor cluster (CeCl{sub 6}Li{sub 6}Cs{sub 8}){sup 12+} embedded in a quantum mechanical embedding potential of the host. The calculations provide interpretations of unexplained experimental observations as due to higher energy IVCT absorptions, and allow to reinterpret others. The existence of another IVCT emission of lower energy, at around 14 000-16 000 cm{sup −1} less than the 5dt{sub 2g} emission, is also predicted.

  9. Rare earth effect of yttrium on formation and property of Cr2O3 oxide film formed on Co-Cr binary alloy

    Institute of Scientific and Technical Information of China (English)

    JIN Huiming; FELIX A. Congrado; AROYAVE M. Hayara

    2006-01-01

    The isothermal oxidizing kinetics of Co-40Cr alloy and its yttrium ion-implanted samples were studied at 1000℃ in air by thermal-gravity analysis (TGA). Scanning electronic microscopy (SEM) was used to examine the Cr2O3 oxide film's morphology after oxidation. Secondary ion mass spectrum (SIMS) method was used to examine the binding energy change of chromium caused by Y-doping and its influence on formation of Cr2O3 film. Acoustic emission (AE) method was used in situ to monitor the cracking and spalling of oxide films formed on both samples during oxidizing and subsequent air-cooling stages. Theoretical model simulating the film fracture process was proposed to analyze the acoustic emission spectrum both on time domain and on AE-event number domain. It is found that yttrium ionimplantation can remarkably reduce the isothermal oxidizing rate of Co-40Cr and improve the anti-cracking and anti-spalling properties of Cr2O3 oxide film. Reasons for the improvement are mainly that the implanted yttrium can reduce the grain size of Cr2O3 oxide, increase the high temperature plasticity of oxide film, and remarkably reduce the number and size of Cr2O3/Co-40Cr interfacial defects.

  10. Hydrothermal preparation and photoluminescent property of LiY(MoO4)2:Pr3+red phosphors for white light-emitting diodes

    Institute of Scientific and Technical Information of China (English)

    LI Zhao; ZHAO Xicheng; JIANG Yuanru

    2015-01-01

    Praseodymium doped lithium yttrium molybdate LiY1−xPrx(MoO4)2 (x=0.005–0.025) phosphors were successfully prepared by the hydrothermal method. The phase, morphology, and luminescent property of the prepared phosphors were investigated by X-ray diffraction and scanning electron microscopy. The results indicated that doping of Pr3+ions did not change the main phase of the phosphors. The samples emitted red luminescence upon excitation at 453 nm and the strongest emission peak corresponding to the characteristic transition of the Pr3+ion: 3P0→3F2 was observed at 657 nm. LiY(MoO4)2:Pr3+red phosphors could be effectively ex-cited by blue light emitting-diodes to emit red light;thus, acting as potential candidates for compensating the red light deficiency of cerium doped yttrium aluminum garnet yellow phosphor.

  11. Spectroscopic analysis of LYSO:Ce crystals

    Science.gov (United States)

    Martins, A. F.; Carreira, J. F. C.; Rodrigues, J.; Sedrine, N. Ben; Castro, I. F. C.; Correia, P. M. M.; Veloso, J. F. C. A.; Rino, L.; Monteiro, T.

    2017-02-01

    Rare earth orthosilicates are among the most widely used scintillator materials in the last decades. Particularly, lutetium-yttrium oxyorthosilicate (LYSO) is known to exhibit great potentialities in the field of radiation detectors for medical imaging. Consequently, an in-depth knowledge of the material properties is of utmost interest for the mentioned applications. In this work the spectroscopic properties of commercial cerium doped lutetium-yttrium oxyorthosilicate crystals (LYSO:Ce) were investigated by Raman spectroscopy, steady state photoluminescence, photoluminescence excitation and time resolved photoluminescence. Site selective excitation was used under steady state (325 nm) and pulsed (266 nm) conditions to separately investigate the temperature dependence of the 5d → 4f Ce1 and Ce2 luminescence, allowing to establish the thermal quenching dependence of the Ce2 optical center. In the case of the Ce1 optical center, a luminescence quantum efficiency of 78% was obtained from 14 K to room temperature with 266 nm photon excitation.

  12. A randomized controlled trial of peeling and aspiration of Elschnig pearls and neodymium: yttrium-aluminiumgarnet laser capsulotomy

    Institute of Scientific and Technical Information of China (English)

    Rahul; Bhargava; Prachi; Kumar; Shiv; Kumar; Sharma; Avinash; Kaur

    2015-01-01

    AIM: To compare surgical peeling and aspiration and neodymium yttrium garnet laser capsulotomy for pearl form of posterior capsule opacification(PCO).METHODS: A prospective, randomized, double blind,study was done at Rotary Eye Hospital, Maranda,Palampur, India, Santosh Medical College Hospital,Ghaziabad, India and Laser Eye Clinic, Noida India.Consecutive patients with pearl form of PCO following surgery, phacoemulsification, manual small incision cataract surgery and conventional extracapsular cataract extraction(ECCE) for age related cataract, were randomized to have peeling and aspiration or neodymium yttrium garnet laser capsulotomy. Corrected distance visual acuity(CDVA), intra-operative and postoperative complications were compared.RESULTS: A total of 634 patients participated in the study, and 314(49.5%) patients were randomized to surgical peeling and aspiration group and 320(50.5%) to the Nd:YAG laser group. The mean pre-procedural log MAR CDVA in peeling and neodymium: yttrium-aluminium-garnet(Nd:YAG) laser group was 0.80 ±0.25 and 0.86 ±0.22, respectively. The mean final CDVA in peeling group(0.22 ±0.23) was comparable to Nd:YAG group(0.24 ±0.28; t-test, P =0.240). There was a significant improvement in vision after both the procedures(P <0.001). A slightly higher percentage of patients in Nd:YAG laser group(283/88.3%) than in peeling group(262/83.4%) had a CDVA of 0.5(20/63) or better at 9mo(P <0.001). On the contrary, patients havingCDVA worse than 1.00(20/200) was also significantly higher in Nd:YAG laser group as compared to peeling group(25/7.7% vs 15/4.7%, respectively). On application of ANCOVA, there was less than 0.001% risk that PCO thickness and total laser energy had no effect on rate of complications in Nd:YAG laser group and less than 0.001% risk that PCO thickness had no effect on complications in peeling group respectively. Sum of square analysis suggests that in the Nd:YAG laser group,thick PCO had a stronger impact on complications

  13. A composite material based on nanoparticles of yttrium (III) oxide for the selective and sensitive electrochemical determination of acetaminophen

    Energy Technology Data Exchange (ETDEWEB)

    Baytak, Aysegul Kutluay [Department of Medical Laboratory, Vocational School of Health Services, Harran University, Şanlıurfa 63510 (Turkey); Teker, Tugce; Duzmen, Sehriban [Department of Chemistry, Harran University, Şanlıurfa 63510 (Turkey); Aslanoglu, Mehmet, E-mail: maslanoglu@harran.edu.tr [Department of Chemistry, Harran University, Şanlıurfa 63510 (Turkey)

    2016-09-01

    An electrochemical sensor was prepared by modifying a glassy carbon electrode (GCE) with a composite of yttrium (III) oxide nanoparticles (Y{sub 2}O{sub 3}NPs) and carbon nanotubes (CNTs) for the determination of acetaminophen (ACT). Compared with a bare GCE and CNTs/GCE, the Y{sub 2}O{sub 3}NPs/CNTs/GCE exhibited a well-defined redox couple for ACT and highly enhanced the current response. The separations in the anodic and cathodic peak potentials (ΔE{sub p}) for ACT were 552 mV, 24 mV and 10 mV at ba4re GCE, CNTs/GCE and Y{sub 2}O{sub 3}NPs/CNTs/GCE, respectively. The observation of only 10 mV of ΔE{sub p} for ACT at Y{sub 2}O{sub 3}NPs/CNTs/GCE was a clear indication of a great acceleration of the electrode process compared to bare GCE and GCE modified with CNTs. Also, L-ascorbic acid (L-AA) and L-tyrosine (L-TRY) did not interfere with the selective determination of ACT. Square wave voltammetry (SWV) was performed for the quantification of ACT. A linear plot was obtained for current responses versus the concentrations of ACT over the range from 1.0 × 10{sup −10} to 1.8 × 10{sup −8} M with a detection limit of 3.0 × 10{sup −11} M (based on 3S{sub b}/m). The proposed composite material provided high electrocatalytic activity, improved voltammetric behavior, good selectivity and good reproducibility. The accurate quantification of ACT makes the proposed electrode of great interest for the public health. - Highlights: • A voltammetric sensor based on yttrium oxide was prepared for the detection of ACT. • The proposed electrode has greatly accelerated the voltammetric process of ACT. • A detection limit of 0.03 nM was obtained for ACT. • The proposed electrode exhibited great selectivity for ACT in the presence of L-AA and L-TRY. • The composite material exhibited high sensitivity, good stability and excellent reproducibility.

  14. Uranium, yttrium, and rare earth elements accumulation during the Cretaceous anoxic events in carbonaceous rocks in the Pacific Ocean

    Science.gov (United States)

    Savelyeva, Olga; Philosofova, Tatyana; Bergal-Kuvikas, Olga; Savelyeva, Svetlana

    2017-04-01

    We have studied the carbonate-siliceous section of paleooceanic Albian-Cenomanian deposits on the Kamchatsky Mys peninsula (Eastern Kamchatka, Russia) [1].The section is represented by a rhythmic alternation of planktonic limestones and jaspers, accumulated in the open ocean environment. The rhythmicity can be attributed to climate variations that reflect a fluctuation of astronomical parameters (Milankovitch cycles) [2, 3].The section contains two beds enriched in organic carbon, corresponding to the two oceanic anoxic events - MCE and OAE2 [3]. The maximum content of organic matter in those beds reaches 68%. Our geochemical studies revealed an enrichment of the carbonaceous rocks in some major and trace elements including PGE, in comparison with the surrounding limestone and jasper [4].The accumulation of the ore elements in carbonaceous beds is caused by euxinic conditions during sedimentation.The content of uranium, yttrium, and rare earth elements in carbonaceous rocks is up to 60, 142 and 312 ppm respectively. Phosphate grains (bone detritus) with microinclusions of yttrium and uranium minerals were revealed in the carbonaceous rocks using the scanning electron microscope. These data prove the hypothesis of the sorbtion of U and Y by phosphate detritus from seawater. Microprobe analysis also showed an increased content of Cu, Zn, V in some pyrite framboids, which indicates that these elements are fixed in rocks by Fe-sulphide phase or organic matter under euxinic conditions. Our research may bring us closer to understanding the mechanism of syngenetic accumulation of metals in the black shales. This work was supported by the RFBR (No. 16-05-00546). [1] Palechek, T.N., Savelyev, D.P., Savelyeva, O.L. (2010) Stratigraphy and Geological Correlation 18, (1) 63-82. [2] Savelyeva, O.L. (2010). Vestnik Kraunts. Nauki o zemle 1 (15), 45-55 (in Russian). [3] Savelyev, D.P., Savelyeva, O.L., Palechek, T.N., Pokrovsky, B.G. (2012) Geophysical Research Abstracts, 14, EGU

  15. Comparison of the partitioning behaviours of yttrium, rare earth elements, and titanium between hydrogenetic marine ferromanganese crusts and seawater

    Science.gov (United States)

    Bau, M.; Koschinsky, A.; Dulski, P.; Hein, J.R.

    1996-01-01

    In order to evaluate details of the partitioning behaviours of Y, rare earth elements (REEs), and Ti between inorganic metal oxide surfaces and seawater, we studied the distribution of these elements in hydrogenetic marine ferromanganese (Fe-Mn) crusts from the Central Pacific Ocean. Nonphosphatized Fe-Mn crusts display shale-normalized rare earths and yttrium (REYSN) patterns (Y inserted between Dy and Ho) that are depleted in light REEs (LREEs) and which show negative anomalies for YSN, and positive anomalies for LaSN, EuSN, GdSN, and in most cases, CeSN. They show considerably smaller Y/ Ho ratios than seawater or common igneous and clastic rocks, indicating that Y and Ho are fractionated in the marine environment. Compared to P-poor crusts, REYSN patterns of phosphatized Fe-Mn crusts are similar, but yield pronounced positive YSN anomalies, stronger positive LaSN anomalies, and enrichment of the HREEs relative to the MREEs. The data suggest modification of REY during phosphatization and indicate that studies requiring primary REY distributions or isotopic ratios should be restricted to nonphosphatized (layers of) Fe-Mn crusts. Apparent bulk coefficients, KMD, describing trace metal partitioning between nonphosphatized hydrogenetic Fe-Mn crusts and seawater, are similar for Pr to Eu and decrease for Eu to Yb. Exceptionally high values of KCeD, which are similar to those of Ti, result from oxidative scavenging of Ce and support previous suggestions that Ce(IV) is a hydroxide-dominated element in seawater. Yttrium and Gd show lower KD values than their respective neighbours in the REY series. Results of modelling the exchange equilibrium between REY dissolved in seawater and REY sorbed on hydrous Fe-Mn oxides corroborate previous studies that suggested the surface complexation of REY can be approximated by their first hydroxide binding constant. Negative "anomalies" occur for stabilities of bulk surface complexes of Gd, La, and particularly Y. The differences in

  16. Transarterial radioembolization using yttrium-90 microspheres in the treatment of hepatocellular carcinoma: a review on clinical utility and developments

    Directory of Open Access Journals (Sweden)

    Cappelli A

    2014-11-01

    Full Text Available Alberta Cappelli,1 Cinzia Pettinato,2 Rita Golfieri1 1Radiology Unit, 2Medical Physics Unit, Department of Medical and Surgical Sciences, Alma Mater Studiorum – University of Bologna, S Orsola-Malpighi Hospital, Bologna, Italy Abstract: A selective intra-arterial liver injection using yttrium-90-loaded microspheres as sources for internal radiation therapy is a form of transarterial radioembolization (TARE. Current data from the literature suggest that TARE is effective in hepatocellular carcinoma (HCC and is associated with a low rate of adverse events; however, they are all based on retrospective series or non-controlled prospective studies, since randomized controlled trials comparing the other liver-directed therapies for intermediate and locally advanced stages HCC are still ongoing. The available data show that TARE provides similar or even better survival rates. TARE is very well tolerated and has a low rate of complications; these complications do not result from the embolic effects but mainly from the unintended irradiation to non-target tissue, including the liver parenchyma. The complications can be further reduced by accurate patient selection and a strict pre-treatment evaluation, including dosimetry and assessment of the vascular anatomy. First-line TARE is best indicated for intermediate-stage patients (according to the Barcelona Clinic Liver Cancer [BCLC] staging classification who are poor candidates for transarterial chemoembolization or patients having locally advanced disease with segmental or lobar branch portal vein thrombosis. Moreover, data are emerging regarding the use of TARE in patients classified slightly above the criteria for liver transplantation with the purpose of downstaging them. TARE can also be applied as a second-line treatment in patients progressing to transarterial chemoembolization or sorafenib; a large number of Phase II/III trials are in progress in order to evaluate the best association with

  17. Cathodic micro-arc electrodeposition of yttrium stabilized zirconia (YSZ) coatings on FeCrAl alloy

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The formation of ceramic coatings on metal substrate by cathodic electrolytic deposition (CELD) has received more attention in recent years. But only thin films can be prepared via CELD. Yttrium stabilized zirconia (YSZ) ceramic coatings were deposited on FeCrAl alloy by a novel technique--cathodic micro-arc electrodeposition (CMED). The result shows that, when a high pulse electric field is applied to the cathode which was pre-deposited with a thin YSZ film, dielectric breakdown occurs and micro-arc discharges appear. Coatings with reasonably thickness of ~300μm and crystalline structure can be deposited on the cathode by utilizing the energy of the micro-arc. The thickness of the as-deposited coating is dominated by the voltage and the frequency. Y2O3 is co-deposited with ZrO2 when Y(NO3)3 was added to the electrolyte, which stabilize t-phase, t′- phase and c-phase of ZrO2 at room temperature. The amount of the m-ZrO2 in the coating is diminished by increasing the concentration of Y(NO3)3 in the electrolyte. This report describes the processing of CMED and studies the microstructure of the deposited YSZ coatings.

  18. Formation mechanism and luminescence properties of nanostructured sodium yttrium fluoride corn sticks synthesized by precipitation transformation method

    Institute of Scientific and Technical Information of China (English)

    田俐; 赵瑞妮; 王金晶; 陈琳; 薛建荣; 肖秋国

    2015-01-01

    Monodisperse sodium yttrium fluoride corn sticks with hexagonal nanostructure were successfully prepared by a facile and repeatable precipitation transformation method. The phase and morphology of the products were characterized with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The growth mechanism was studied, indicating that the initial generated Y(OH)3 gradually translated into YF3 and then transformed into corn stick-like H-NaYF4 nanoparticles owing to the crucial role of fluorine ions in the solution. The up-conversion (UC) luminescence properties of H-NaYF4:20%Yb3+,2%Er3+ nanocrystals were discussed. The intensive green emission in the range of 510–570 nm was attributed to the (2H11/2,4S3/2)→4I15/2 transition and the weaker red emission between 640 and 680 nm was originating from the4F9/2→4I15/2 transition.

  19. Synthesis and Crystal Structure of a New Potassium Yttrium Diphosphate Dihydrate KYP2O7·2H2O

    Institute of Scientific and Technical Information of China (English)

    Férid M. Horchani-Naifer K

    2008-01-01

    The dihydrated potassium yttrium diphosphate, KYP2O7·2H2O, has been synthe-sized for the first time. Single-crystal XRD study has allowed the determination of its structure and correct formula. It crystallizes in the monoclinic system, space group P21/c, with the cell parameters a = 7.7069(3), b = 10.5801(4), c = 10.0204(5) ?, β = 93.24(3)°, V = 815.76(6) ?3, Z = 4, Mr = 337.98, F(000) = 656, Dc = 2.752 g/cm3 and μ = 8.073 mm-1. The single-crystal structure was solved from 1856 unique reflections with the final R = 0.0365 and wR = 0.0772, refined with 119 parameters. The atomic arrangement of KYP2O7·2H2O is built by the P2O7 groups, the YO7 and the KO10 polyhedrons which are connected by corner and edge-sharing to form a three-dimensional framework. Water molecules are directly bonded to the Y and K atoms, and they are located in channels running along the a direction.

  20. Numerical Simulation of Yttrium Aluminum Garnet(YAG) Single Crystal Growth by Resistance Heating Czochralski(CZ) Method

    Energy Technology Data Exchange (ETDEWEB)

    You, Myeong Hyeon; Cha, Pil Ryung [Kookmin University, Seoul (Korea, Republic of)

    2017-01-15

    Yttrium Aluminum Garnet (YAG) single crystal has received much attention as the high power solid-state laser’s key component in industrial and medical applications. Various growth methods have been proposed, and currently the induction-heating Czochralski (IHCZ) growth method is mainly used to grow YAG single crystal. Due to the intrinsic properties of the IHCZ method, however, the solid/liquid interface has a downward convex shape and a sharp tip at the center, which causes a core defect and reduces productivity. To produce YAG single crystals with both excellent quality and higher yield, it is essential to control the core defects. In this study, using computer simulations we demonstrate that the resistance-heating CZ (RHCZ) method may avoid a downward convex interface and produce core defect free YAG single crystal. We studied the effects of various design parameters on the interface shape and found that there was an optimum combination of design parameter and operating conditions that produced a flat solid-liquid interface.

  1. PEO-b-P4VP/Yttrium Hydroxide Hybrid Nanotubes as Supporter for Catalyst Gold Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Qian Yang; Dao-yong Chen

    2012-01-01

    The adsorption of poly (ethylene oxide)-b-poly(4-vinylpyridine)(PEO-b-P4VP) micelles onto the surface of yttrium hydroxide nanotubes (YNTs) resulted in the hybrid nanotubes with a dense P4VP inner layer and a stretched PEO outer layer surrounding YNTs. The dense P4VP layer was further stabilized by the crosslinking using 1,4-dibromobutane as the crosslinker.Then,the crosslinked hybrid nanotubes (CHNTs) were used as a novel nano supporter for loading the catalyst gold nanoparticles (GNPs) within the crosslinkcd P4VP layer.The resultant GNPs/CHNTs (GNTs loaded on CHNTs) were applied to catalyze the reduction reaction of p-nitrophenol.The results indicate that this novel nano supporter has advantages such as good dispersity in the suspension,high capacity in loading GNPs (0.87 mmol/g),high catalytic activity of the loaded GNPs (12.9 μmol-1min-1),and good reusability of GNTs/CHNTs.

  2. Phase composition and morphology of nanoparticles of yttrium orthophosphates synthesized by microwave-hydrothermal treatment: The influence of synthetic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Vanetsev, A.S., E-mail: alexander.vanetsev@ut.ee [Institute of Physics, University of Tartu, Ravila 14c, Tartu 50411 (Estonia); Samsonova, E.V. [Institute of Physics, University of Tartu, Ravila 14c, Tartu 50411 (Estonia); Gaitko, O.M. [Kurnakov Institute of General and Inorganic Chemistry RAS, Leninskii Prospekt 31, Moscow 119991 (Russian Federation); Keevend, K. [Institute of Physics, University of Tartu, Ravila 14c, Tartu 50411 (Estonia); Popov, A.V. [Prokhorov General Physics Institute RAS, Vavilov St. 38, Moscow 119991 (Russian Federation); Mäeorg, U. [Institute of Chemistry, University of Tartu, Ravila 14a, Tartu 50411 (Estonia); Mändar, H.; Sildos, I. [Institute of Physics, University of Tartu, Ravila 14c, Tartu 50411 (Estonia); Orlovskii, Yu.V. [Institute of Physics, University of Tartu, Ravila 14c, Tartu 50411 (Estonia); Prokhorov General Physics Institute RAS, Vavilov St. 38, Moscow 119991 (Russian Federation)

    2015-08-05

    Highlights: • We synthesized YPO{sub 4} and YPO{sub 4}⋅0.8H{sub 2}O nanoparticles by microwave-hydrothermal treatment. • We studied “conditions–composition–properties” relations for this synthetic path. • We revealed the mechanism of stabilization of YPO{sub 4}⋅0.8H{sub 2}O phase at high temperatures. - Abstract: Herein we report the study of the influence of synthesis conditions during the microwave-hydrothermal crystallization of freshly precipitated gels on the phase composition and morphology of the rare-earth doped yttrium orthophosphates nanoparticles. We characterize the nanoparticles of YPO{sub 4} and YPO{sub 4}⋅0.8H{sub 2}O using X-ray diffraction analysis, TEM, and FT-IR spectroscopy. Furthermore, we argue that for the given phase the degree of crystallinity and thus the sample morphology depend strongly on the synthesis conditions. We establish that the hexagonal hydrate phase can be obtained by means of microwave-hydrothermal method if one uses phosphate anion excess or adjusts pH of the reaction mixture. Also we show that the metastable hydrate phase is most likely stabilized by hydroxyl groups at elevated temperatures.

  3. Eu(III)-doped aluminium yttrium oxide; Oxido misto de itrio-aluminio dopado com Eu(III)

    Energy Technology Data Exchange (ETDEWEB)

    Nassar, Eduardo J.; Avila, Lilian R.; Pereira, Paula F.S.; Lima, Omar J. de; Rocha, Lucas A.; Mello, Cesar; Ciuffi, Katia J. [Universidade de Franca, SP (Brazil); Carlos, Luis D. [Universidade de Aveiro (Portugal). Dept. de Fisica

    2005-04-01

    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 Y{sub 4}Al{sub 2}O{sub 9} (YAM) and Y{sub 3}Al{sub 5}O{sub 12} (YAG) phases. At 800 and at 1500 deg C the PL spectra display the Eu(III) lines characteristic of the YAM monoclinic phase. The {sup 5}D{sub 0}{yields}{sup 7}F{sub 2} transition is favored relatively to the {sup 5}D{sub 0}{yields}{sup 7}F{sub 1} lines. However, at 1100 deg C the cubic YAG is the preferential phase and the {sup 5}D{sub 0}{yields}{sup 7}F{sub 1} 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 {sup 5}D{sub 0}{yields}{sup 7}F{sub 2} and the {sup 5}D{sub 0}{yields}{sup 7}F{sub 1} transitions. (author)

  4. Conductivity recovery by redox cycling of yttrium doped barium zirconate proton conductors and exsolution of Ni-based sintering additives

    Science.gov (United States)

    Nasani, Narendar; Pukazhselvan, D.; Kovalevsky, Andrei V.; Shaula, Aliaksandr L.; Fagg, Duncan P.

    2017-01-01

    Owing to their high stability and good bulk proton conductivity yttrium doped barium zirconate-based materials are considered as potential electrolytes for protonic ceramic fuel cell applications. Nonetheless, their refractory nature leads to problematic densification that can necessitate the addition of sintering additives. While these additives assist processing, undesirable, strong, negative impacts on proton conductivity have been regularly reported. The current work assesses the potential sintering additives NiO, BaNiOx and BaY2NiO5 and their influence on subsequent electrochemical properties of BaZr0.85Y0.15O3-δ. All sintering additives allow dense electrolyte materials (>95%) to be formed at temperatures below 1450 °C, with enhanced grain growth; with the largest grain growth being offered by the BaNiOx additive. Degradation in overall electrical performances is shown to be bulk related, corresponding to large reductions in bulk conductivity up to two orders of magnitude, whilst grain boundary conductivities are less affected. Most importantly, the current article demonstrates that these high depletions in bulk proton conductivity can be effectively inverted by redox cycling in relatively mild conditions (750 °C, cycling from N2 to H2 and back to N2), opening the way to improve processing of these materials whilst maintaining high levels of proton conductivity.

  5. Investigation of the timescale of the spin-Seebeck effect in yttrium iron garnet from pico to nanoseconds

    Science.gov (United States)

    Jamison, John; Yang, Zihao; Myers, Roberto

    We investigate the timescale of the spin-Seebeck effect (SSE) in yttrium iron garnet (YIG) by exciting transient thermal gradients with 150-fs laser heating pulses. The transient thermal gradient generates a spin current which is measured by a Pt top contact via the inverse spin Hall-effect (ISHE). A pulse selection system is used to lower the repetition rate of the laser to low frequencies (e.g. 10 kHz) such that the transient thermal gradient decays completely before the arrival of the next pulse. Lock-in detection, referenced at the laser repetition rate, is used to measure ISHE as a function of magnetic field, verifying that SSE is generated from the individual ultrafast laser pulses. Next, utilizing an optical delay line we vary the time delay between two equal fluence pulses. The correlated ISHE signal is measured with lock-in detection as a function of delay time with 0.1 ps resolution out to 1 ns to examine the characteristic decay times of the ultrafast laser pulse induced spin-Seebeck effect. Work supported by ARO MURI W911NF-14-1-0016.

  6. Application of reflectance confocal microscopy to evaluate skin damage after irradiation with an yttrium-scandium-gallium-garnet (YSGG) laser.

    Science.gov (United States)

    Yue, Xueping; Wang, Hongwei; Li, Qing; Li, Linfeng

    2017-02-01

    The objective of this study was to observe the characteristics of the skin after irradiation with a 2790-nm yttrium-scandium-gallium-garnet (YSGG) laser using reflectance confocal microscopy (RCM). A 2790-nm YSGG laser was used to irradiate fresh foreskin (four doses, at spot density 3) in vitro. The characteristics of microscopic ablative columns (MAC), thermal coagulation zone (TCZ), and microscopic treatment zones (MTZ) were observed immediately after irradiation using digital microscope and RCM. The characteristics of MAC, TCZ, and MTZ with variations in pulse energy were comparatively analyzed. After irradiation, MAC, TCZ, and MTZ characteristics and undamaged skin between MTZs can be observed by RCM. The depth and width of MTZ obviously increased with the increase in pulse energy. At 80, 120, and 160 mJ/microbeam (MB), the MTZ actual area and proportion were about two times that of the theoretical value and three times at 200 mJ/MB. With increases in depth, the single MAC gradually decreased in a fingertip-shaped model, with TCZ slowly increasing, and MTZ slightly decreasing in a columnar shape. RCM was able to determine the characteristics of thermal injury on the skin after the 2790-nm YSGG laser irradiation with different pulse energies. Pulse energy higher than 200 mJ/MB may have much larger thermal injury and side effect. RCM could be used in the clinic in future.

  7. Thin yttrium iron garnet films grown by pulsed laser deposition: Crystal structure, static, and dynamic magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, N. S., E-mail: nsokolov@fl.ioffe.ru; Fedorov, V. V.; Korovin, A. M.; Suturin, S. M.; Baranov, D. A.; Gastev, S. V.; Krichevtsov, B. B.; Bursian, V. E.; Lutsev, L. V. [Ioffe Physical-Technical Institute of Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation); Maksimova, K. Yu.; Grunin, A. I. [Immanuel Kant Baltic Federal University, Kaliningrad 236041 (Russian Federation); Tabuchi, M. [Synchrotron Radiation Research Center, Nagoya University, Nagoya 464-8603 (Japan)

    2016-01-14

    Pulsed laser deposition has been used to grow thin (10–84 nm) epitaxial layers of Yttrium Iron Garnet Y{sub 3}Fe{sub 5}O{sub 12} (YIG) on (111)–oriented Gadolinium Gallium Garnet substrates at different growth conditions. Atomic force microscopy showed flat surface morphology both on micrometer and nanometer scales. X-ray diffraction measurements revealed that the films are coherent with the substrate in the interface plane. The interplane distance in the [111] direction was found to be by 1.2% larger than expected for YIG stoichiometric pseudomorphic film indicating presence of rhombohedral distortion in this direction. Polar Kerr effect and ferromagnetic resonance measurements showed existence of additional magnetic anisotropy, which adds to the demagnetizing field to keep magnetization vector in the film plane. The origin of the magnetic anisotropy is related to the strain in YIG films observed by XRD. Magneto-optical Kerr effect measurements revealed important role of magnetization rotation during magnetization reversal. An unusual fine structure of microwave magnetic resonance spectra has been observed in the film grown at reduced (0.5 mTorr) oxygen pressure. Surface spin wave propagation has been demonstrated in the in-plane magnetized films.

  8. Thermal, Mechanical and Electrical Properties of the PEO-based Solid Polymer Electrolytes Filled by Yttrium Oxide Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    LIANG Guijie; XU Jie; XU Weilin; SHEN Xiaolin; BAI Zhikui; YAO Mu

    2012-01-01

    The novel composite lithium solid polymer electrolytes (SPEs) composed of polyethylene oxide (PEO) matrix and yttrium oxide (Y2O3) nanofillers were prepared by a solution casting method.The crystal morphology of the SPEs was characterized by polarized optical microscope (POM) and wide-angle X-ray diffraction (WAXD).The induced nucleation and steric hindrance effects of Y203 nanofillers result in the increased amount as well as decreased size of PEO sphemlites which are closely related to the crystallinity of the SPEs.As the Y2O3 contents increase from 0 wt% to 15 wt,the crystallinity of the SPEs decreases proportionally.The thermal,mechanical and electrical properties of the SPEs were investigated by thermal gravimetric analysis (TGA),dynamic mechanical analysis (DMA) and AC impedance method,respectively.The physical properties including thermal,mechanical and electrical performances,depending remarkably on the polymer-filler interactions between PEO and Y2O3 nanoparticles,are improved by different degrees with the increase of Y2O3 contents.The (PEO)21Lii/10 wt%Y2O3 composite SPE exhibits the optimal room-temperature ionic conductivity of 5.95×10-5 S*cm-1,which satisfies the requirements of the conventional electrochromic devices..

  9. Microstructure and Texture Evolution in a Yttrium-Containing ZM31 Alloy: Effect of Pre- and Post-deformation Annealing

    Science.gov (United States)

    Tahreen, N.; Zhang, D. F.; Pan, F. S.; Jiang, X. Q.; Li, D. Y.; Chen, D. L.

    2016-12-01

    Microstructure and texture evolution of as-extruded ZM31 magnesium alloys with different amounts of yttrium (Y) during pre- and post-deformation annealing were examined with special attention given to the effect of Y on recrystallization. It was observed that the extruded ZM31 alloys exhibited a basal texture with the basal planes parallel to the extrusion direction (ED). The compression of the extruded alloys in the ED to a strain amount of 10 pct resulted in c-axes of hcp unit cells rotating toward the anti-compression direction due to the occurrence of extension twinning. Annealing of the extruded alloys altered the microstructure and texture, and the subsequent compression after annealing showed a relatively weak texture and a lower degree of twinning. A reverse procedure of pre-compression and subsequent annealing was found to further weaken the texture with a more scattered distribution of orientations and to lead to the vanishing of the original basal texture. With increasing Y content, both the extent of extension twinning during compression and the fraction of recrystallization during annealing decreased due to the role of Y present in the substitutional solid solution and in the second-phase particles, leading to a significant increase in the compressive yield strength.

  10. Push-out bond strength of oval versus circular fiber posts irradiated by erbium-doped yttrium aluminum garnet laser.

    Science.gov (United States)

    Uzun, Ismail; Keskin, Cangül; Özsu, Damla; Güler, Buğra; Aydemir, Hikmet

    2016-09-01

    Fiber posts in conjunction with resin cements are widely used to provide retention in endodontically treated teeth. The bond strength of restorative materials to root canal dentin is an important issue for the long-term success of restorative procedures. The push-out test is widely used to measure the bonding between the post and radicular dentin. The purpose of this in vitro study was to evaluate the effect of erbium-doped yttrium aluminum garnet (Er-YAG) laser treatment of dentinal walls on the bond strength of circular and oval fiber posts luted in oval root canals. Forty mandibular premolar teeth were endodontically treated and restored with 2 different intracanal post systems. Push-out tests were performed and data were analyzed by using 2-way analysis of variance and post hoc Bonferroni tests. Laser pretreatment of dentinal walls resulted in higher push-out bond strength than that of the nonlasered groups (Pfiber posts showed significantly higher push-out bond strength values than those of circular fiber posts in the coronal region (P.05). The laser pretreatment with an oval ultrasonic tip of an oval fiber post system improved bonding to root canal dentin when compared with a circular post system with conventional preparation. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  11. Temperature dependence of the magnon spin diffusion length and magnon spin conductivity in the magnetic insulator yttrium iron garnet

    Science.gov (United States)

    Cornelissen, L. J.; Shan, J.; van Wees, B. J.

    2016-11-01

    We present a systematic study of the temperature dependence of diffusive magnon spin transport using nonlocal devices fabricated on a 210-nm yttrium iron garnet film on a gadolinium gallium garnet substrate. In our measurements, we detect spin signals arising from electrical and thermal magnon generation, and we directly extract the magnon spin diffusion length λm for temperatures from 2 to 293 K. Values of λm obtained from electrical and thermal generation agree within the experimental error with λm=9.6 ±0.9 μ m at room temperature to a minimum of λm=5.5 ±0.7 μ m at 30 K. Using a two-dimensional finite element model to fit the data obtained for electrical magnon generation we extract the magnon spin conductivity σm as a function of temperature, which is reduced from σm=3.7 ±0.3 ×105S /m at room temperature to σm=0.9 ±0.6 ×104S /m at 5 K. Finally, we observe an enhancement of the signal originating from thermally generated magnons for low temperatures where a maximum is observed around T =7 K . An explanation for this low-temperature enhancement is however still missing and requires additional investigation.

  12. Dynamic photopatterning of cells in situ by Q-switched neodymium-doped yttrium ortho-vanadate laser

    Science.gov (United States)

    Deka, Gitanjal; Okano, Kazunori; Kao, Fu-Jen

    2014-01-01

    Cellular micropattering has been increasingly adopted in quantitative biological experiments. A Q-switched pulsed neodymium-doped yttrium ortho-vanadate (Nd) laser directed in-situ microfabrication technique for cell patterning is presented. A platform is designed uniquely to achieve laser ablation. The platform is comprised of thin gold coating over a glass surface that functions as a thermal transducer and is over-layered by a cell repellant polymer layer. Micropatterns are engraved on the platform, subsequently exposing specific cell adhesive micro-domains by ablating the gold-polymer coating photothermally. Experimental results indicate that the proposed approach is applicable under culture conditions, viable toward cells, and has a higher engraving speed. Possible uses in arraying isolated single cells on the platform are also shown. Additionally, based on those micro-patterns, dynamic cellular morphological changes and migrational speed in response to geometrical barriers are studied to demonstrate the potential applications of the proposed approach. Our results further demonstrate that cells in narrower geometry had elongated shapes and higher migrational speed than those in wider geometry. Importantly, the proposed approach will provide a valuable reference for efforts to study single cell dynamics and cellular migration related processes for areas such as cell division, wound healing, and cancer invasion.

  13. Erbium-doped yttrium aluminum garnet as a magnetic refrigerant for low temperature x-ray detectors

    Science.gov (United States)

    Kushino, Akihiro; Aoki, Yuji; Yamasaki, Noriko Y.; Namiki, Takahiro; Ishisaki, Yoshitaka; Matsuda, Tatsuma D.; Ohashi, Takaya; Mitsuda, Kazuhisa; Yazawa, Takashi

    2001-12-01

    Garnets doped with rare-earth elements can be used in adiabatic demagnetization refrigerators. We have measured the specific heat and magnetization of a single crystal yttrium aluminum garnet (YAG) doped with 30% Er3+ ion at temperatures between 93 mK and 8 K under magnetic fields up to 8.0 T along the crystal axis. From the specific heat and magnetization, we derived consistent temperature and magnetic-field dependence of the magnetic entropy. Under zero magnetic field, the magnetic entropy begins to decrease below 2 K and becomes half of R ln 2 at ˜160 mK. This decrease is considered to be due to an antiferromagnetic short-range ordering among Er3+ ions. This behavior of the specific heat in the measured temperature range can be explained by a model in which both the crystalline-electric-field ground state and the first excited state are included. The operating temperature of the Er3+-doped YAG as a magnetic coolant is estimated to extend down to ˜100 mK, which is lower than those with nonsubstituted garnets such as gallium-gadolinium-garnet used in the range ˜4.2-15 K. With a doping level of 30%, we estimate that ˜6 kg of Er3+-doped YAG exhibits the same cooling performance at 60 mK as the 916 g of ferric-ammonium-alum salt used for the x-ray spectrometer (microcalorimeter detectors) on the Astro-E satellite.

  14. Uptake and Speciation of Inorganic Arsenic with Cellulose Fibre Coated with Yttrium Hydroxide Layer as a Novel Green Sorbent

    Institute of Scientific and Technical Information of China (English)

    安明日; 张晓星; 杨婷; 陈明丽; 王建华

    2012-01-01

    A novel adsorbent was developed by coating yttrium hydroxide precipitate layer on cellulose fibre. This material takes up ca. 98% of 5 μg·L 1 As(Ⅲ) and As(V) at low pH (pH〈7), while a favorable selectivity for As(V) was achieved within pH 11--12. In practice, a mini-column packed with Y(OH)3 precipitate layer coated cellulose fibre particles was incorporated into a sequential injection system for selective uptake of arsenate at pH 11.5. The retained arsenate was afterwards recovered with 50μL of 0.8 mol.L l NaOH solution as eluent, followed by hydride generation in a reaction medium of 2.0 mol·L-1 HCl and 1.0% NaBH4 solution (W/V, in 0.5% NaOH) after pre-reduction of arsenate to arsenite by KI-ascorbic acid (5%, W/V), with detection by atomic fluorescence spec- trometry. Total inorganic arsenic was quantitatively taken up at pH 6.0 by following the same procedure and arsenic speciation was performed by difference. With a sample volume of 1.0 mL, an enrichment factor of 16.4 was derived with a detection limit of 17 ng.L-1 within a linear range of 0.05--2.0μg.L ]. A relative standard deviation (RSD) of 2.6% (0.5 μg·L-1, n= 11) was achieved. The procedure was validated by analyzing arsenic in a certified refer- ence material GBW 09101 (human hair), and speciation process requires no organic solvents, thus Y(OH)3 coated of inorganic arsenic in natural water samples. The entire cellulose fibre provides a green adsorbent.

  15. Data consistencies of swift heavy ion induced damage creation in yttrium iron garnet analyzed by different techniques

    Energy Technology Data Exchange (ETDEWEB)

    Meftah, A., E-mail: ameftah@hotmail.fr [LRPCSI, Faculté des Sciences, Université 20 août 1955-Skikda, BP 26, Route d’El-Hadaïek, 21000 Skikda (Algeria); Benhacine, H. [LRPCSI, Faculté des Sciences, Université 20 août 1955-Skikda, BP 26, Route d’El-Hadaïek, 21000 Skikda (Algeria); Benyagoub, A. [CIMAP (CEA-CNRS-ENSICAEN-Université de Caen Basse Normandie), BP 5133, 14070 Caen Cedex 5 (France); Grob, J.J. [InESS, CNRS, Université de Strasbourg, 23 rue du Loess, 67037 Strasbourg Cedex 2 (France); Izerrouken, M. [CRND, BP 43, Sebbala, Draria, Algiers (Algeria); Kadid, S. [LRPCSI, Faculté des Sciences, Université 20 août 1955-Skikda, BP 26, Route d’El-Hadaïek, 21000 Skikda (Algeria); Khalfaoui, N. [CIMAP (CEA-CNRS-ENSICAEN-Université de Caen Basse Normandie), BP 5133, 14070 Caen Cedex 5 (France); Stoquert, J.P. [InESS, CNRS, Université de Strasbourg, 23 rue du Loess, 67037 Strasbourg Cedex 2 (France); Toulemonde, M. [CIMAP (CEA-CNRS-ENSICAEN-Université de Caen Basse Normandie), BP 5133, 14070 Caen Cedex 5 (France); Trautmann, C. [GSI, Helmholtz Zentrum für Schwerionenforschung, Planckstrasse 1, 64291 Darmstadt (Germany); Technische Universität Darmstadt, Petersenstraße 23, 64287 Darmstadt (Germany)

    2016-01-01

    Pronounced swelling is observed when single crystals of yttrium iron garnet Y{sub 3}Fe{sub 5}O{sub 12} (YIG) are irradiated in the electronic energy loss regime with various swift heavy ions. The out-of-plane swelling was measured by scanning across the border line between an irradiated and a virgin area of the sample surface with the tip of a profilometer. The step height varied between 20 and 600 nm depending on fluence, electronic energy loss and total range of the ions. The step height divided by the ion range as a function of the ion fluence exhibits a linear increase in the initial phase and saturates at high fluences leading to a density decrease of around 1.7%. With complementary channeling-Rutherford-backscattering experiments (c-RBS), the damage fraction and the corresponding damage cross section were extracted and compared to the cross section deduced from swelling measurements. Irradiation effects were also characterized by scanning force microscopy (SFM). A threshold for damage creation as deduced from all the present physical characterizations is 5.5 ± 1.0 keV/nm. The value is in full agreement with previous measurements confirming that swelling and SFM characterizations can provide information concerning the electronic energy loss threshold for track formation. In contrast, track radii deduced from swelling measurements are smaller and radii from SFM are larger than deduced from c-RBS analysis. The results of Y{sub 3}Fe{sub 5}O{sub 12} of this work are compared with data obtained for other crystalline oxides and for ionic crystals.

  16. Combined Intralesional Neodymium-Doped Yttrium Aluminium Garnet Laser and Intratumoral Ligation as Curative Treatment for Craniofacial Arteriovenous Malformations.

    Science.gov (United States)

    Rojvachiranonda, Nond; Lerdlum, Sukalaya; Mahatumarat, Charan

    2016-03-01

    Craniofacial arteriovenous malformation (AVM), although very rare, has been a very difficult problem to treat especially when it is large and involves important structures. Surgical resection often results in unacceptable complications but still not curative. At our institution, treatment by combined intralesional neodymium-doped yttrium aluminium garnet laser and intratumoral ligation has been successful in venous malformation. This minimally invasive technique was then applied to more challenging AVM on the head and neck. Disease control was studied using clinical parameters and magnetic resonance imaging.Four patients with moderate-to-severe (Schobinger 2-4) craniofacial AVM were treated by this technique from 2001 to 2011. Patient age ranged from 2 to 51 years (mean: 25 years). After 2 to 4 treatments and follow-up period of 1456 days, 3 (75%) were cured. One of them was infant with huge mass and secondary pulmonary hypertension. Clinical cure was achieved after 3 treatments without residual cardiovascular compromise. The other patient (25%) had cheek mass with intraorbital involvement. The authors did not treat periorbital lesion so as to avoid triggering intraorbital spreading. The rest of the cheek lesion was clinically and radiologically cured.Laser energy setting, ablative technique, and skin cooling are the main factors determining the success. Individualized laser settings and properly set endpoints can increase treatment effectiveness in shorter period. In conclusion, this minimally invasive technique was successful in curing AVM without complication. With more clinical study and development of soft tissue monitoring tools, it is possible that intralesional laser could become the treatment of choice for all cutaneous AVM.

  17. Radiofrequency ablation after selective internal radiation therapy with Yttrium90 microspheres in metastatic liver disease-Is it feasible?

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, R.T. [Institute of Clinical Radiology, Ludwig Maximilians-University - Campus Grosshadern, Marchioninstr. 15, 81377 Munich (Germany)], E-mail: rthoffma@med.uni-muenchen.de; Jakobs, T.F. [Institute of Clinical Radiology, Ludwig Maximilians-University - Campus Grosshadern, Marchioninstr. 15, 81377 Munich (Germany); Kubisch, C.H. [Department of Medicine/Gastroenterology, Ludwig Maximilians-University - Campus Grosshadern, Munich (Germany); Stemmler, H.J. [Department of Internal Medicine III/Haematology and Oncology, Ludwig Maximilians-University - Campus Grosshadern, Munich (Germany); Trumm, C. [Institute of Clinical Radiology, Ludwig Maximilians-University - Campus Grosshadern, Marchioninstr. 15, 81377 Munich (Germany); Tatsch, K. [Department of Nuclear Medicine, Ludwig Maximilians-University - Campus Grosshadern, Munich (Germany); Helmberger, T.K. [Institute of Clinical and Diagnostic Radiology and Nuclear Medicine, Munich - Bogenhausen, Munich (Germany); Reiser, M.F. [Institute of Clinical Radiology, Ludwig Maximilians-University - Campus Grosshadern, Marchioninstr. 15, 81377 Munich (Germany)

    2010-04-15

    This retrospective study analyzes, whether patients suffering from extensive hepatic metastatic disease treated with SIRT can become suitable candidates for RFA.Within 38 months 46 patients (26 female, 20 male; age 32-75 years) bearing an extensive hepatic metastatic disease were treated with SIRT. Patients suffered from metastases of breast cancer (16/46), colorectal cancer (CRC) (21/46), neuroendocrine (3/46), and other primary carcinomas (6/46). The indication for SIRT was otherwise untreatable metastases confined to the liver. Forty-three patients received single-session whole-liver radioembolization treatment using Yttrium90 resin microspheres with a mean activity of 2.13 GBq. In 1 patient SIRT was confined to the left and in 2 patients to the right liver lobe. In 3 patients major complications (2/3 gastric ulceration and 1/3 oedematous pancreatitis) and in 24 patients minor complications occurred (acute abdominal/epigastric pain and/or nausea). Follow-up CT and/or MRI were obtained in 44 of 46 patients. In 5 of 44 patients tumor load decreased substantially (3/5 breast cancer, 1/5 CRC and 1/5 pancreatic cancer) making RFA feasible. The patients were referred for RFA after the first 3-month follow-up. RFA of the liver was successful in all cases in terms of complete ablation. In selected patients radioembolization is able to downstage liver metastases to an extent making a subsequent RFA suitable and therefore allows increasing the number of patients with a 'complete response' after a minimally invasive therapy.

  18. Embolisation of the Gastroduodenal Artery is Not Necessary in the Presence of Reversed Flow Before Yttrium-90 Radioembolisation

    Energy Technology Data Exchange (ETDEWEB)

    Daghir, Ahmed A., E-mail: ahmeddaghir@doctors.net.uk [Imperial College Healthcare NHS Trust, Department of Radiology (United Kingdom); Gungor, Hatice [Imperial College Healthcare NHS Trust, Department of Oncology (United Kingdom); Haydar, Ali A. [Barts and the London NHS Trust, Department of Radiology (United Kingdom); Wasan, Harpreet S. [Imperial College Healthcare NHS Trust, Department of Oncology (United Kingdom); Tait, Nicholas P. [Imperial College Healthcare NHS Trust, Department of Radiology (United Kingdom)

    2012-08-15

    Introduction: The gastroduodenal artery (GDA) is usually embolised to avoid nontarget dispersal before yttrium-90 (Y{sup 90}) radioembolisation to treat liver metastases. In a minority of patients, there is retrograde flow in the GDA. The purpose of this study was to determine if there is any increased risk from maintaining a patent GDA in patients with reversed flow. Materials and Methods: A retrospective review was performed of all patients undergoing Y{sup 90} radioembolisation at our institution. The incidence of toxicities arising from nontarget radioembolisation by way of the GDA (gastric/duodenal ulceration, gastric/duodenal bleeding, and pancreatitis) and death occurring within 2 months of treatment were compared between the reversed and the antegrade GDA groups. Results: Ninety-two patients underwent preliminary angiography. Reversed GDA flow was found on angiography in 14.1% of cases; the GDA was not embolised in these patients. The GDA was coiled in 55.7% of patients with antegrade GDA flow to prevent inadvertent dispersal of radioembolic material. There was no increased toxicity related to nontarget dispersal by way of the GDA, or increased early mortality, in patients with reversed GDA flow (P > 0.05). Conclusion: In patients with reversed GDA flow, maintenance of a patent GDA before administration of Y{sup 90} radioembolisation does not increase the risk of toxicity from nontarget dispersal. Therapeutic injection, with careful monitoring to identify early vascular stasis, may be safely performed beyond the origin of the patent GDA. A patent GDA with reversed flow provides forward drive for infused particles and may allow alternative access to the hepatic circulation.

  19. The synthesis of single-phase yttrium iron garnet doped zinc and some structural and magnetic properties

    Science.gov (United States)

    Peña-Garcia, R.; Delgado, A.; Guerra, Y.; Duarte, G.; Gonçalves, L. A. P.; Padrón-Hernández, E.

    2017-01-01

    This work presents the single phase formation of yttrium iron garnet (YIG) doped with divalent Zn ions in samples fabricated by the sol–gel method and heat treated at 900 °C. We used stoichiometric amounts according to the formula Y3(Fe1‑x Zn x )5O12, (x  =  0, 0.01, 0.03 and 0.05). The x-ray diffraction data show the single phase formation with the lattice parameter increasing with the Zn concentration. The scanning electron microscopy images showed nanoparticles with a rod format, crowding more as the doping increased. Energy dispersive x-ray spectroscopy results confirmed the presence of Zn in the YIG structure. The Raman spectroscopy measurements show characteristic peaks of the YIG structure, and some characteristic peaks increasing with the Zn concentration. This confirms our successful result doping the YIG structure with the divalent Zn ion replacing the Fe positions. Magnetic measurements show coercive field values dominated by the shape and agglomeration of nanoparticles. For low doping we have a value of 88.50 Oe attributed to the particles’ morphology, and for the highest Zn concentrations the effects of agglomeration diminish the coercivity to 50 Oe. The total magnetic moment for low Zn concentrations increases slightly due to the replacement of Fe by Zn. For higher Zn concentrations, we can see a diminution of the magnetic saturation which is due to the growth of the crystal lattice parameter and thus a weakening of the exchange interactions between the magnetic sub-lattices in the Y3(Fe1‑x Zn x )5O12 ferrimagnetic compound. Changes in the magnetic moment do not have large values, showing the possibility of doping without a drastic change in this quantity.

  20. Effect of yttrium on microstructure and mold filling capacity of a near-α high temperature titanium alloy

    Directory of Open Access Journals (Sweden)

    Zhao Ertuan

    2012-11-01

    Full Text Available The addition of rare earth yttrium (Y can improve the performances of high temperature titanium alloys, such as the tensile ductility, thermal stability and creep property, etc. However, few studies on the effect of Y on the castability of titanium alloys have been carried out, which is significant to fabrication of thin-walled complex titanium castings by investment casting. In this study, the microstructure and mold filling capacity of a Ti-1100 alloy with different Y additions (0, 0.1wt.%, 0.3wt.%, 0.5wt.% and 1.0wt.% were investigated systematically through investment casting experiments, and the casting experiments were carried out in a centrifugal titanium casting machine. The microstructures of the alloy were observed via the optical microscopy, scanning electron microscopy and transmission electron microscopy. The mold filling capacity was tested by using of a grid pattern and was evaluated by the number of segments completely filled by the cast alloy. The results indicate that the grain size is decreased and the mold filling capacity is improved significantly with increasing the addition of Y from 0 to 1.0wt.%. The average primary β grain size of Ti-1100 alloy is reduced from 250 μm to 50 μm and the mold filling capacity is increased from 61.5% to 100%. Considering the potential harmful effect on tensile properties of titanium alloys due to high concentrations of Y, it is suggested that Y addition should be about 0.3wt.%.

  1. Long-pulsed 1064-nm neodymium:yttrium-aluminum-garnet laser treatment for refractory warts on hands and feet.

    Science.gov (United States)

    Kimura, Utako; Takeuchi, Kaori; Kinoshita, Ayako; Takamori, Kenji; Suga, Yasushi

    2014-03-01

    Common warts (verruca vulgaris) are the most commonly seen benign cutaneous tumors. However, warts in the hands and feet regions often respond poorly to treatment, some are resistant to more than 6 months of treatment with currently available modalities, including cryotherapy, being defined as refractory warts. We investigated the usefulness of long-pulsed neodymium:yttrium-aluminum-garnet (LP-Nd:YAG) treatment for refractory warts. The clinical trial was conducted on 20 subjects (11 male, nine female) with a total of 34 lesions (periungual/subungual areas, plantar areas, fingers and/or toes). All the subjects suffered from refractory warts despite conventional treatments for more than 6 months. The patients were administrated up to six sessions of treatment, at intervals of 4 weeks between sessions, with an LP-Nd:YAG at a spot size of 5 mm, pulse duration of 15 msec and fluence of 150-185 J/cm(2) . Evaluation of the treatment results at 24 weeks after the initial treatment showed complete clearance of the refractory warts in 56% of the patients. Histological evaluation showed separation of the dermis and epidermis at the basement membrane with coagulated necrosis of the wart tissue in the lower epidermis, as well as coagulation and destruction of the blood vessels in the papillary dermis following the laser irradiation. No scarring, post-hyperpigmentary changes or serious adverse events were documented. Our preliminary results show that LP-Nd:YAG treatments are safe and effective for refractory warts of hands and feet, causing minimal discomfort, and is a viable treatment alternative. © 2014 Japanese Dermatological Association.

  2. A retrospective analysis of selective internal radiation therapy (SIRT) with yttrium-90 microspheres in patients with unresectable hepatic malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Omed, A., E-mail: aliomed0101@doctors.org.u [Manchester Medical School, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PT (United Kingdom); Lawrance, J.A.L. [Radiology Department, Christie NHS Foundation Trust, Wilmslow Road, Manchester, M20 4BX (United Kingdom); Murphy, G. [Radiology Department, Manchester Royal Infirmary, Oxford Road, Manchester, M13, 9WL (United Kingdom); Laasch, H.-U. [Radiology Department, Christie NHS Foundation Trust, Wilmslow Road, Manchester, M20 4BX (United Kingdom); Wilson, G.; Illidge, T. [Oncology, Christie NHS Foundation Trust, Wilmslow Road, Manchester, M20 4BX (United Kingdom); Tipping, J.; Zivanovic, M. [Nuclear Medicine, Christie NHS Foundation Trust, Wilmslow Road, Manchester, M20 4BX (United Kingdom); Jeans, S. [Radiology Department, Manchester Royal Infirmary, Oxford Road, Manchester, M13, 9WL (United Kingdom)

    2010-09-15

    Aim: To evaluate the efficacy and safety of selective internal radiation therapy (SIRT). Materials and methods: A retrospective analysis was undertaken of all patients who underwent SIRT at a single institution. Diagnostic and therapeutic angiograms, computed tomography (CT) images, positron-emission tomography (PET) images, and planar isotope images were analysed. The response to SIRT was analysed using radiological data and tumour markers. Overall survival, complications, and side effects of SIRT were also analysed. Results: The initial 12 patients were included on an intention-to-treat basis, between 21/09/2005 and 07/05/2008. All patients had advanced disease and multiple prior courses of chemotherapy. One patient did not receive yttrium-90 due to complex vascular anatomy; the remaining 11 patients underwent 13 SIRT treatment episodes following work-up angiography. A response was seen using PET in 80% of patients. Using CT, the response of the tumour to therapy in the treated hepatic segments demonstrated a 20% partial response, stable disease in 50%, and progressive disease in 30%. Estimated median survival was 229 days, with 64% of patients still alive at the time of writing. No major complications were observed, although 82% of patients experienced side-effects following SIRT, mainly nausea, vomiting, and abdominal pain. Conclusions: There have been no complications in the 12 SIRT patients. Tumour response was seen in four out of five patients who underwent PET. Objective CT response rates were mixed and are perhaps partially explained by advanced disease and limitations of using measurements to assess response. This complex and potentially hazardous service has been successfully and safely established.

  3. Selective intraarterial radionuclide therapy with yttrium-90 (Y-90 microspheres for hepatic neuroendocrine metastases: Initial experience at a single center

    Directory of Open Access Journals (Sweden)

    Arslan Nuri

    2011-01-01

    Full Text Available Background/Aim. Selective intraarterial radionuclide therapy (SIRT with Yttrium-90 (Y-90 microspheres is also known as radioembolization and delivers high doses of radiation to hepatic tumors with minimum healthy liver exposure. The aim of this study was to present our preliminary experience in the role of liver directed radiotherapy with Y-90 microspheres for the treatment of unresectable hepatic metastases from neuroendocrine tumors (NET. Methods. The results of SIRT in 10 patients (5 males, 5 females; mean age 48.7 years; age range 24-73 years with metastatic liver disease from NETs during the period from April 2008 through August 2010 were reviewed. All patients had meticulous pre- and post-imaging studies as a part of their work-up procedure, as well as serologic tests of liver function to determine the extent of liver function damage. The patients who were eligible for SIRT had pretreatment visceral angiography to define and occlude non-target arteries. Results. The mean ± SD administered SIR-Spheres® activity was 1.49 ± 0.42 GBq (range 0.72-2.21 GBq in all the patients. These treatments delivered a dose of 99.73 ± 66.36 Gy (range 49- 420.8 Gy to the target tumors. The estimated dose to the lungs and normal liver was 4.45 ± 1.95 Gy (range 2.4-8.5 Gy and 26.73 ± 14.19 Gy (range 5-58.9 Gy, respectively. Overall response rate of 90% and patient tolerance was satisfactory for most patients. Conclusion. From our limited experience, we can conclude that SIRT with Y-90 microspheres is a safe and efficacious treatment option for patients with liver metastasis of NET without any serious side effects.

  4. Bactericidal Effect of Erbium-Doped Yttrium Aluminum Garnet Laser and Photodynamic Therapy on Aggregatibacter Actinomycetemcomitans Biofilm on Implant Surface.

    Science.gov (United States)

    Saffarpour, Anna; Fekrazad, Reza; Heibati, Maryam Naghavi; Bahador, Abbas; Saffarpour, Aida; Rokn, Amir R; Iranparvar, Aysel; KharaziFard, Mohammad J

    2016-01-01

    Peri-implantitis is a common complication of dental implants. The first step of treatment is elimination of bacterial biofilm and disinfection of the implant surface. This study sought to compare the effects of an erbium-doped yttrium aluminum garnet (Er:YAG) laser, photodynamic therapy using an indocyanin green-based photosensitizer (ICG-based PS) and diode laser, toluidine blue O (TBO) photosensitizer and light-emitting diode (LED) light source, and 2% chlorhexidine (CHX) on biofilm of Aggregatibacter actinomycetemcomitans to sandblasted, large-grit, acid-etched (SLA) implant surfaces. Fifty SLA implants were divided into five groups and were incubated with A actinomycetemcomitans bacteria to form bacterial biofilm. Group 1 underwent Er:YAG laser radiation (with 10-Hz frequency, 100-mJ energy, and 1-W power); group 2 was subjected to LED (with 630-nm wavelength and maximum output intensity of 2.000 to 4.000 mW/cm(2)) and TBO as a photosensitizer; group 3 was exposed to diode laser radiation (with 810-nm wavelength and 300-mW power) and ICG-based PS; and group 4 was immersed in 2% CHX. Group 5 was the control group, and the samples were rinsed with normal saline. The number of colony-forming units (CFU) per implant was then calculated. Data were analyzed using one-way analysis of variance (ANOVA), and the five groups were compared. Significant differences was found between the control group and the other groups (P laser was more effective than Er:YAG laser irradiation in suppression of this organism (P < .01). There was no significant difference between groups 2 and 3. The antibacterial effect of 2% CHX was greater than that of other understudy methods.

  5. Yttrium aluminum garnet (YAG) obtained by rare-earth mixed oxide (RE{sub 2}O{sub 3})

    Energy Technology Data Exchange (ETDEWEB)

    Castro, D.F.; Daguano, J.K.M.F.; Rodrigues Junior, D., E-mail: claudinei@demar.eel.usp.b [Universidade de Sao Paulo (EEL/USP), Lorena, SP (Brazil). Escola de Engenharia; Santos, C. [Centro Universitario de Volta Redonda (MEMAT/UNIFOA), RJ (Brazil); Suzuki, P.A. [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil); Silva, O.M.M. [Centro Tecnico Aeroespacial (CTA-IAE), Sao Jose dos Campos, SP (Brazil). Inst. de Atividades Espaciais. Div. de Materiais

    2010-07-01

    In this work, the substitution of commercial Y{sub 2}O{sub 3} by a rare earth mixed oxide, RE{sub 2}O{sub 3}, to form Yttrium aluminum Garnet-Y{sub 3}Al{sub 5}O{sub 12}, was investigated. Al{sub 2}O{sub 3}:Y{sub 2}O{sub 3} and Al{sub 2}O{sub 3}:RE{sub 2}O{sub 3} powder-mixtures, in a molar ratio of 60:40, were milled and subsequently cold uniaxially-pressed. Compacts were sintered at 1000, 1400 or 1600 deg C, for 120 minutes. RE{sub 2}O{sub 3} oxide was characterized by high-resolution synchrotron X-ray diffraction (HRXRD) and compared to Y{sub 2}O{sub 3}. X-ray diffraction pattern of the RE{sub 2}O{sub 3} indicates a true solid solution formation. Rietveld refinement of the sintered YAG and (RE)AG reveled a similar crystal structure to the YAGs obtained by the use of Al{sub 2}O{sub 3}-Y{sub 2}O{sub 3} or Al{sub 2}O{sub 3}-RE{sub 2}O{sub 3} respectively. Microstructural analysis of both, YAG or (RE)AG, revealed similar grain sizes of about 2.5 {mu}m besides mechanical properties, with hardness of 400HV and fracture toughness of 3.8MPa.m1/2. It could be, thus, demonstrated that pure Y{sub 2}O{sub 3} can be substituted by the rare-earth solid solution, RE{sub 2}O{sub 3}, in the formation YAGs, presenting similar microstructural and mechanical properties. (author)

  6. Efficacy and safety of Erbium-doped Yttrium Aluminium Garnet fractional resurfacing laser for treatment of facial acne scars

    Directory of Open Access Journals (Sweden)

    Balakrishnan Nirmal

    2013-01-01

    Full Text Available Background: Treatment of acne scars with ablative fractional laser resurfacing has given good improvement. But, data on Indian skin are limited. A study comparing qualitative, quantitative, and subjective assessments is also lacking. Aim: Our aim was to assess the improvement of facial acne scars with Erbium-doped Yttrium Aluminium Garnet (Er:YAG 2940 nm fractional laser resurfacing and its adverse effects in 25 patients at a tertiary care teaching hospital. Methods: All 25 patients received four treatment sessions with Er:YAG fractional laser at 1-month interval. The laser parameters were kept constant for each of the four sittings in all patients. Qualitative and quantitative assessments were done using Goodman and Barron grading. Subjective assessment in percentage of improvement was also documented 1 month after each session. Photographs were taken before each treatment session and 1 month after the final session. Two unbiased dermatologists performed independent clinical assessments by comparing the photographs. The kappa statistics was used to monitor the agreement between the dermatologists and patients. Results: Most patients (96% showed atleast fair improvement. Rolling and superficial box scars showed higher significant improvement when compared with ice pick and deep box scars. Patient′s satisfaction of improvement was higher when compared to physician′s observations. No serious adverse effects were noted with exacerbation of acne lesions forming the majority. Conclusion: Ablative fractional photothermolysis is both effective and safe treatment for atrophic acne scars in Indian skin.Precise evaluation of acne scar treatment can be done by taking consistent digital photographs.

  7. A composite material based on nanoparticles of yttrium (III) oxide for the selective and sensitive electrochemical determination of acetaminophen.

    Science.gov (United States)

    Baytak, Aysegul Kutluay; Teker, Tugce; Duzmen, Sehriban; Aslanoglu, Mehmet

    2016-09-01

    An electrochemical sensor was prepared by modifying a glassy carbon electrode (GCE) with a composite of yttrium (III) oxide nanoparticles (Y2O3NPs) and carbon nanotubes (CNTs) for the determination of acetaminophen (ACT). Compared with a bare GCE and CNTs/GCE, the Y2O3NPs/CNTs/GCE exhibited a well-defined redox couple for ACT and highly enhanced the current response. The separations in the anodic and cathodic peak potentials (ΔEp) for ACT were 552mV, 24mV and 10mV at ba4re GCE, CNTs/GCE and Y2O3NPs/CNTs/GCE, respectively. The observation of only 10mV of ΔEp for ACT at Y2O3NPs/CNTs/GCE was a clear indication of a great acceleration of the electrode process compared to bare GCE and GCE modified with CNTs. Also, l-ascorbic acid (l-AA) and l-tyrosine (l-TRY) did not interfere with the selective determination of ACT. Square wave voltammetry (SWV) was performed for the quantification of ACT. A linear plot was obtained for current responses versus the concentrations of ACT over the range from 1.0×10(-10) to 1.8×10(-8)M with a detection limit of 3.0×10(-11)M (based on 3Sb/m). The proposed composite material provided high electrocatalytic activity, improved voltammetric behavior, good selectivity and good reproducibility. The accurate quantification of ACT makes the proposed electrode of great interest for the public health.

  8. Evaluation of critical distances for energy transfer between Pr3+ and Ce3+ in yttrium aluminium garnet

    Science.gov (United States)

    Zeng, Peng; Wei, Xiantao; Zhou, Shaoshuai; Yin, Min; Chen, Yonghu

    2016-09-01

    A series of Pr3+/Ce3+ doped yttrium aluminium garnet (Y3Al5O12 or simply YAG) phosphors were synthesized to investigate the energy transfer between Pr3+ and Ce3+ for their potential application in a white light-emitting diode and quantum information storage and processing. The excitation and emission spectra of YAG:Pr3+/Ce3+ were measured and analyzed, and it revealed that the reabsorption between Pr3+ and Ce3+ was so weak that it can be ignored, and the energy transfer from Pr3+ (5d) to Ce3+ (5d) and Ce3+ (5d) to Pr3+ (1D2) did occur. By analyzing the excitation and the emission spectra, the energy transfer from Pr3+ (5d) to Ce3+ (5d) and Ce3+ (5d) to Pr3+ (1D2) was examined in detail with an original strategy deduced from fluorescence dynamics and the Dexter energy transfer theory, and the critical distances of energy transfer were derived to be 7.9 Å and 4.0 Å for Pr3+ (5d) to Ce3+ (5d) and Ce3+ (5d) to Pr3+ (1D2), respectively. The energy transfer rates of the two processes of various concentrations were discussed and evaluated. Furthermore, for the purpose of sensing a single Pr3+ state with a Ce3+ ion, the optimal distance of Ce3+ from Pr3+ was evaluated as 5.60 Å, where the probability of success reaches its maximum value of 78.66%, and meanwhile the probabilities were evaluated for a series of Y3+ sites in a YAG lattice. These results will be of valuable reference for achievement of the optimal energy transfer efficiency in Pr3+/Ce3+ doped YAG and other similar systems.

  9. A systematic review on the safety and effectiveness of yttrium-90 radioembolization for hepatocellular carcinoma with portal vein tumor thrombosis

    Directory of Open Access Journals (Sweden)

    Zhongzhi Jia

    2016-01-01

    Full Text Available Background/Aim: Over the past two decades, several advances have been made in the management of patients with hepatocellular carcinoma (HCC and portal vein tumor thrombosis (PVTT. Yttrium-90 ( 90 Y radioembolization has recently been made a treatment option for patients with HCC and PVTT. However, there is still a need to systematicly evaluate the outcomes of 90 Y radioembolization for HCC and PVTT. We aimed to assess the safety and effectiveness of 90 Y radioembolization for HCC and PVTT. We performed a systematic review of clinical trials, clinical studies, and abstracts from conferences that qualified for analysis. Materials and Methods: PubMed, EMBASE, Cochrane Database of Systematic Review, CINAHL, and the "gray" literature (Google Scholar were searched for all reports (1991-2016 related to 90 Y radioembolization for HCC and PVTT. Results: A total of 14 clinical studies and three abstracts from conferences including 722 patients qualified for the analysis. The median length of follow-up was 7.2 months; the median time to progression was 5.6 months, and median disease control rate was 74.3%. Radiological response data were reported in five studies, and the median reported value of patients with complete response, partial response, stable disease, and progressive disease were 3.2%, 16.5%, 31.3%, and 28%, respectively. The median survival was 9.7 months for all patients, including the median overall survival (OS were 12.1, 6.1 months of Child-Pugh class A and B patients, and the median OS were 6.1, 13.4 months of main and branch PVTT patients, respectively. The common toxicities were fatigue, nausea/vomiting, abdominal pain, mostly not requiring medical intervention needed no medication intervention. Conclusions: 90 Y radioembolization is a safe and effective treatment for HCC and PVTT.

  10. Yttrium-90 Resin Microsphere Radioembolization Using an Antireflux Catheter: An Alternative to Traditional Coil Embolization for Nontarget Protection

    Energy Technology Data Exchange (ETDEWEB)

    Morshedi, Maud M., E-mail: maud.morshedi@my.rfums.org; Bauman, Michael, E-mail: mbauman@ucsd.edu; Rose, Steven C., E-mail: scrose@ucsd.edu; Kikolski, Steven G., E-mail: skikolski@gmail.com [University of California San Diego Health Sciences, Radiology Department, University of California San Diego Medical Center (United States)

    2015-04-15

    PurposeSerious complications can result from nontarget embolization during yttrium-90 (Y-90) transarterial radioembolization. Hepatoenteric artery coil embolization has been traditionally performed to prevent nontarget radioembolization. The U.S. Food and Drug Administration–approved Surefire Infusion System (SIS) catheter, designed to prevent reflux, is an alternative to coils. The hypothesis that quantifiable SIS procedural parameters are comparable to coil embolization was tested.MethodsFourteen patients aged 36–79 years with colorectal, neuroendocrine, hepatocellular, and other predominantly bilobar hepatic tumors who underwent resin microsphere Y-90 radioembolization using only the SIS catheter (n = 7) versus only detachable coils (n = 7) for nontarget protection were reviewed retrospectively. Procedure time, fluoroscopy time, contrast dose, radiation dose, and cost were evaluated.ResultsMultivariate analysis identified significant cohort differences in the procedural parameters evaluated (F(10, 3) = 10.39, p = 0.04). Between-group comparisons of the pretreatment planning procedure in the SIS catheter group compared to the coil embolization group demonstrated a significant reduction in procedure time (102.6 vs. 192.1 min, respectively, p = 0.0004), fluoroscopy time (14.3 vs. 49.7 min, respectively, p = 0.0016), and contrast material dose (mean dose of 174.3 vs. 265.0 mL, respectively, p = 0.0098). Procedural parameters were not significantly different between the two groups during subsequent dose delivery procedures. Overall cost of combined first-time radioembolization procedures was significantly less in the SIS group ($4252) compared to retrievable coil embolization ($11,123; p = 0.001).ConclusionThe SIS catheter results in a reduction in procedure time, fluoroscopy time, and contrast material dose and may be an attractive cost-effective alternative to detachable coil embolization for prevention of nontarget radioembolization.

  11. Quantitative comparison of PET and Bremsstrahlung SPECT for imaging the in vivo yttrium-90 microsphere distribution after liver radioembolization.

    Directory of Open Access Journals (Sweden)

    Mattijs Elschot

    Full Text Available BACKGROUND: After yttrium-90 ((90Y microsphere radioembolization (RE, evaluation of extrahepatic activity and liver dosimetry is typically performed on (90Y Bremsstrahlung SPECT images. Since these images demonstrate a low quantitative accuracy, (90Y PET has been suggested as an alternative. The aim of this study is to quantitatively compare SPECT and state-of-the-art PET on the ability to detect small accumulations of (90Y and on the accuracy of liver dosimetry. METHODOLOGY/PRINCIPAL FINDINGS: SPECT/CT and PET/CT phantom data were acquired using several acquisition and reconstruction protocols, including resolution recovery and Time-Of-Flight (TOF PET. Image contrast and noise were compared using a torso-shaped phantom containing six hot spheres of various sizes. The ability to detect extra- and intrahepatic accumulations of activity was tested by quantitative evaluation of the visibility and unique detectability of the phantom hot spheres. Image-based dose estimates of the phantom were compared to the true dose. For clinical illustration, the SPECT and PET-based estimated liver dose distributions of five RE patients were compared. At equal noise level, PET showed higher contrast recovery coefficients than SPECT. The highest contrast recovery coefficients were obtained with TOF PET reconstruction including resolution recovery. All six spheres were consistently visible on SPECT and PET images, but PET was able to uniquely detect smaller spheres than SPECT. TOF PET-based estimates of the dose in the phantom spheres were more accurate than SPECT-based dose estimates, with underestimations ranging from 45% (10-mm sphere to 11% (37-mm sphere for PET, and 75% to 58% for SPECT, respectively. The differences between TOF PET and SPECT dose-estimates were supported by the patient data. CONCLUSIONS/SIGNIFICANCE: In this study we quantitatively demonstrated that the image quality of state-of-the-art PET is superior over Bremsstrahlung SPECT for the

  12. Synthesis and photoluminescent properties of yttrium vanadate phosphor prepared by the non-hydrolytic sol–gel process

    Energy Technology Data Exchange (ETDEWEB)

    Matos, Marcela G.; Faria, Emerson H. de; Rocha, Lucas A.; Calefi, Paulo S.; Ciuffi, Katia J. [Universidade de Franca, Av. Dr. Armando Salles Oliveira, 201 Franca, SP, CEP 14404-600 (Brazil); Nassar, Eduardo J., E-mail: ejnassar@unifran.br [Universidade de Franca, Av. Dr. Armando Salles Oliveira, 201 Franca, SP, CEP 14404-600 (Brazil); Sarmento, Victor Hugo Vitorino [Universidade Federal de Sergipe, Av. Ver. Olimpio Grande s/n Itabaiana, SE, CEP 49500-000 (Brazil)

    2014-03-15

    We used the non-hydrolytic sol–gel route to synthesize YVO{sub 4} crystalline phases doped with europium III ion. We heat-treated the samples at 600, 800, and 1000 °C and characterized the materials by thermal analysis, X-ray diffraction, small-angle X-ray scattering, and photoluminescence. Larger weight loss occurred until 500 °C, ascribed to removal of residual precursor molecules. X-ray diffraction patterns evidenced YVO{sub 4} phase formation at 600 °C. The crystallite size depended on the heat treatment temperature. SAXS showed that the nature of the system interfaces changed as a function of the thermal treatment. The excitation spectra of the samples displayed the charge transfer band. The photoluminescence data revealed the characteristic transition bands arising from the {sup 5}D{sub 0}→{sup 5}F{sub J} (J=0, 1, 2, 3, and 4) manifolds under maximum excitation at the charge transfer band and the {sup 5}L{sub 6} level of the Eu{sup 3+} ion. The {sup 5}D{sub 0}→{sup 7}F{sub 2} transition dominated the emission spectra, indicating that the Eu{sup 3+} ion occupies a site without inversion center. The lifetime and quantum efficiency values were about 0.70 ms and 50%, respectively, corroborating literature results. -- Highlights: • This study described the preparation of the yttrium vanadate by non-hydrolytic sol–gel. • The SAXS curves can be interpreted from the fractal theory for a two-phase model. • The goal of the work is the preparation of the phosphors at low temperature. • The lifetimes depend on wavelength of the excitation.

  13. The comparison of calculated transition probabilities with luminescence characteristics of erbium(III) in fluoride glasses and in the mixed yttrium-zirconium oxide crystal

    Science.gov (United States)

    Reisfeld, R.; Katz, G.; Jacoboni, C.; De Pape, R.; Drexhage, M. G.; Brown, R. N.; Jørgensen, C. K.

    1983-07-01

    Fluorozirconate glasses containing 2 mole% ErF 3 were prepared by melting the binary fluorides with ammonium bifluoride under an atmosphere of carbon tetrachloride and argon at 850°C. Absorption spectra of these glasses were obtained and the Judd-Ofelt parameters were calculated. Emission spectra and lifetimes of erbium in fluorozirconate glass, in lead-gallium-zinc fluoride glass, and in yttrium-zirconium oxide crystal were measured and compared with the theoretical calculations. Laser emission lines in these materials are deduced from these measurements. It is suggested that materials doped with erbium may serve as light sources for fiber optic waveguides made from the undoped materials.

  14. Increased luminescence and improved decay kinetics in lithium and cerium co-doped yttrium aluminum garnet scintillators grown by the Czochralski method

    Science.gov (United States)

    Dickens, Peter T.; Haven, Drew T.; Friedrich, Stephan; Saleh, Muad; Lynn, Kelvin G.

    2017-03-01

    In this study, four yttrium aluminum garnet single crystals co-doped with cerium and lithium were produced by the Czochralski method and the scintillation and defect properties were investigated. Our results demonstrated an increase in luminescence with Li co-doping as well as elimination of longer decay times. Surprisingly, although Li is monovalent, no oxidation of cerium from Ce3+ to Ce4+ was found as would be expected to maintain charge neutrality. Additionally, thermoluminescence results indicated a reduction in the trapping of charge carriers by shallow and deep traps, and room temperature photoluminescence measurements showed an improvement in the Ce3+ 5d to 4f transition efficiency.

  15. Effect of erbium-doped: yttrium, aluminium and garnet laser irradiation on the surface microstructure and roughness of sand-blasted, large grit, acid-etched implants

    OpenAIRE

    2011-01-01

    Purpose The present study was performed to evaluate the effect of erbium-doped: yttrium, aluminium and garnet (Er:YAG) laser irradiation on sand-blasted, large grit, acid-etched (SLA) implant surface microstructure according to varying energy levels and application times of the laser. Methods The implant surface was irradiated by the Er:YAG laser under combined conditions of 100, 140, or 180 mJ/pulse and an application time of 1 minute, 1.5 minutes, or 2 minutes. Scanning electron microscopy ...

  16. Temperature dependent emission and absorption cross section of Yb3+ doped yttrium lanthanum oxide (YLO) ceramic and its application in diode pumped amplifier.

    Science.gov (United States)

    Banerjee, Saumyabrata; Koerner, Joerg; Siebold, Mathias; Yang, Qiuhong; Ertel, Klaus; Mason, Paul D; Phillips, P Jonathan; Loeser, Markus; Zhang, Haojia; Lu, Shenzhou; Hein, Joachim; Schramm, Ulrich; Kaluza, Malte C; Collier, John L

    2013-07-01

    Temperature dependent absorption and emission cross-sections of 5 at% Yb(3+) doped yttrium lanthanum oxide (Yb:YLO) ceramic between 80K and 300 K are presented. In addition, we report on the first demonstration of ns pulse amplification in Yb:YLO ceramic. A pulse energy of 102 mJ was extracted from a multi-pass amplifier setup. The amplification bandwidth at room temperature confirms the potential of Yb:YLO ceramic for broad bandwidth amplification at cryogenic temperatures.

  17. Separation of lanthanum, hafnium, barium and radiotracers yttrium-88 and barium-133 using crystalline zirconium phosphate and phosphonate compounds as prospective materials for a Ra-223 radioisotope generator

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Teresia [Lynntech Inc., 7610 Eastmark Dr, College Station, TX 77840 (United States); Bestaoui, Naima, E-mail: Naima.Bestaoui@Lynntech.co [Lynntech Inc., 7610 Eastmark Dr, College Station, TX 77840 (United States); Wierzbicki, Melissa; Adams, Todd; Clearfield, Abraham [Lynntech Inc., 7610 Eastmark Dr, College Station, TX 77840 (United States)

    2011-07-15

    Crystalline hybrid organic/inorganic ion exchangers based on zirconium phosphate and phosphonate compounds were evaluated for application in radium-223 generator for radiopharmaceutical applications. Various compositions were synthesized and the selectivity of these materials was determined for inactive lanthanum, hafnium and barium, and radiotracers yttrium-88 and barium-133. The hybrid materials show very efficient lanthanum/barium separation; the response for zirconium phosphate was even better. A small-scale column loaded with pelletized zirconium phosphate compound demonstrated excellent retention of {sup 88}Y and release of {sup 133}Ba.

  18. Hyperpolarized 89Y NMR spectroscopic detection of yttrium ion and DOTA macrocyclic ligand complexation: pH dependence and Y-DOTA intermediates

    Science.gov (United States)

    Ferguson, Sarah; Kiswandhi, Andhika; Niedbalski, Peter; Parish, Christopher; Kovacs, Zoltan; Lumata, Lloyd

    Dissolution dynamic nuclear polarization (DNP) is a rapidly emerging physics technique used to enhance the signal strength in nuclear magnetic resonance (NMR) and imaging (MRI) experiments for nuclear spins such as yttrium-89 by >10,000-fold. One of the most common and stable MRI contrast agents used in the clinic is Gd-DOTA. In this work, we have investigated the binding of the yttrium and DOTA ligand as a model for complexation of Gd ion and DOTA ligand. The macrocyclic ligand DOTA is special because its complexation with lanthanide ions such as Gd3+ or Y3+ is highly pH dependent. Using this physics technology, we have tracked the complexation kinetics of hyperpolarized Y-triflate and DOTA ligand in real-time and detected the Y-DOTA intermediates. Different kinds of buffers were used (lactate, acetate, citrate, oxalate) and the pseudo-first order complexation kinetic calculations will be discussed. The authors would like to acknowledge the support by US Dept of Defense Award No. W81XWH-14-1-0048 and Robert A. Welch Foundation Grant No. AT-1877.

  19. The effect of the beta-emitting yttrium-90 citrate on the dose-response of dicentric chromosomes in human lymphocytes: a basis for biological dosimetry after radiosynoviorthesis.

    Science.gov (United States)

    Schmid, E; Selbach, H-J; Voth, M; Pinkert, J; Gildehaus, F J; Klett, R; Haney, M

    2006-07-01

    The production of dicentric chromosomes in human lymphocytes by beta-particles of yttrium-90 (Y-90) was studied in vitro to provide a basis of biological dosimetry after radiosynoviorthesis (RSO) of persistent synovitis by intra-articular administration of yttrium-90 citrate colloid. Since the injected colloid may leak into the lymphatic drainage exposing other parts of the body to radiation, the measurement of biological damage induced by beta-particles of Y-90 is important for the assessment of radiation risk to the patients. A linear dose-response relationship (alpha = 0.0229 +/- 0.0028 dicentric chromosomes per cell per gray) was found over the dose range of 0.2176-2.176 Gy. The absorbed doses were calculated for exposure of blood samples to Y-90 activities from 40 to 400 kBq using both Monte Carlo simulation and an analytical model. The maximum low-dose RBE, the RBE(M) which is equivalent to the ratio of the alpha coefficients of the dose-response curves, is well in line with published results obtained earlier for irradiation of blood of the same donor with heavily filtered 220 kV X-rays (3.35 mm copper), but half of the RBE(M) relative to weakly filtered 220 kV X-rays. Therefore, it can be concluded that for estimating an absorbed dose during RSO by the technique of biological dosimetry, in vitro and in vivo data for the same radiation quality are necessary.

  20. The evolution of melasma therapy: targeting melanosomes using low-fluence Q-switched neodymium-doped yttrium aluminium garnet lasers.

    Science.gov (United States)

    Kauvar, Arielle N B

    2012-06-01

    Melasma is an acquired disorder of pigmentation that commonly affects women with phototypes III-V, and it has a negative impact on the quality of life in affected individuals. It presents clinically as symmetric tan or brown patches on the face, most often involving the forehead, cheeks, perioral region, and periorbital region. On histologic examination, there is increased melanin in the epidermis and/or an increased number of melanosomes in the dermis, with a normal number of highly melanized and dendritic melanocytes. The mainstay of treatment is the use of sunscreen along with topical medications that suppress melanogenesis. Clearance is usually incomplete and recurrences or exacerbations are frequent, probably because of the poor efficacy in clearing dermal melanosomes. Treatment with high-energy pigment-specific lasers, ablative resurfacing lasers, and fractional lasers results in an unacceptably high rate of postinflammatory hyper- and hypopigmentation and rebound melasma. Recently, promising results have been achieved with low-fluence Q-switched neodymium-doped yttrium aluminium garnet laser treatment, which can selectively target dermal melanosomes without producing inflammation or epidermal damage, in all skin phototypes. This article reviews the current treatment modalities for melasma, the rationale for using and the clinical results of combination therapy with low-fluence Q-switched neodymium-doped yttrium aluminium garnet lasers.

  1. External temperature and pressure effects on thermodynamic properties and mechanical stability of yttrium chalcogenides YX (X=S, Se and Te)

    Energy Technology Data Exchange (ETDEWEB)

    Seddik, T. [Laboratoire de Physique Quantique et de Modélisation Mathématique, Université de Mascara, 29000 Mascara (Algeria); Khenata, R., E-mail: khenata_rabah@yahoo.fr [Laboratoire de Physique Quantique et de Modélisation Mathématique, Université de Mascara, 29000 Mascara (Algeria); Bouhemadou, A.; Guechi, N. [Laboratory for Developing New Materials and their Characterization, Department of Physics, Faculty of Science, University of Setif, 19000 Setif (Algeria); Sayede, A. [Université Lille Nord de France, F-59000 Lille (France); Université-Artois, UCCS, F-62300 Lens (France); CNRS, UMR 8181, F-59650 Villeneuve d’Ascq (France); Varshney, D. [Materials Science Laboratory, School of Physics, Vigyan Bhavan, Devi Ahilya University, Khandwa Road Campus, Indore 452001, Madhya Pradesh (India); Al-Douri, Y. [Institute of Nono Electronic Engineering, University Malaysia Perlis, 01000 Kangar, Perlis (Malaysia); Reshak, A.H. [Institute of Complex Systems, FFPW, CENAKVA, University of South Bohemia in CB, Nove Hrady 37333 (Czech Republic); Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia); Bin-Omran, S. [Department of Physics and Astronomy, Faculty of Science, King Saud University, PO Box 2455, Riyadh 11451 (Saudi Arabia)

    2013-11-01

    The full potential linearized augmented plane wave method within the framework of density functional theory is employed to investigate the structural, thermodynamic and elastic properties of the yttrium chalcogenides (YX: X=S, Se, and Te) in their low-pressure phase (Fm3{sup ¯}m) and high-pressure phase (Pm3{sup ¯}m). The exchange-correlation potential is treated with the generalized gradient approximation of Perdew–Burke–Ernzerhof (GGA-PBE). Temperature dependence of the volume and both adiabatic and isothermal bulk moduli is predicted for a temperature range from 0to1200K for the both phases of the herein considered materials. Furthermore, we have analyzed the thermodynamic properties such as the heat capacities, C{sub V} and C{sub P}, thermal expansion, α, and Debye temperature, Θ{sub D,} under variable pressure and temperature. We have calculated the isothermal elastic constants C{sub ij}{sup T} of the YX monochalcogenides in both NaCl-B1 and CsCl-B2 phases at zero pressure and a temperature range 0−1200K. The results show that rare earth yttrium monochalcogenides are mechanically stable at high temperature. The elastic anisotropy of all studied materials in the two phases has been studied using three different methods.

  2. Research Status of Yttrium-Containing Mg-Zn Based Magnesium Alloys%含钇Mg-Zn系镁合金的研究现状

    Institute of Scientific and Technical Information of China (English)

    张丁非; 徐杏杏; 齐福刚; 郭星星; 朱曾涛

    2012-01-01

    稀土镁合金已成为近些年的研究重点之一.综述了钇(Y)对Mg-Zn系合金的铸态组织、室温和高温力学性能、铸造性能以及耐腐蚀性的影响,以及Y和Ce、Mn和Nd等合金元素的复合加入对Mg-Zn系合金力学性能的影响.最后还指出了Mg-Zn-Y系合金目前存在的问题,并指明了其发展方向.%The Mg-RE alloy is one of the most widely used and studied alloys in recent years. The effects of yttrium (Y) on as-cast microstructure, mechanical properties at room and high temperature, casting property and corrosion resistance of the Mg-Zn alloys, as well as the effect of Y, Ce, Mn, Nd addition on mechanical properties of magnesium alloy were introduced in the paper. The current problem and development trend of the yttrium-containing Mg-Zn based magnesium alloys were summarized.

  3. Hepatic intra-arterial infusion of yttrium-90 microspheres in the treatment of recurrent hepatocellular carcinoma after liver transplantation: A case report

    Institute of Scientific and Technical Information of China (English)

    Louis Rivera; Huan Giap; William Miller; Jonathan Fisher; Donald J Hillebrand; Christopher Marsh; Randolph L Schaffer

    2006-01-01

    Hepatocellular carcinoma (HCC) recurs with a reported frequency of 12%-18% after liver transplantation.Recurrence is associated witha mortality rate exceeding 75%. Approximately one-third of recurrences develop in the transplanted liver and are therefore amenable to local therapy. A variety of treatment modalities have been reported including resection, transarterial chemoembolization (TACE), radiofrequency ablation (RFA),ethanol ablation, cryoablation, and external beam irradiation. Goals of treatment are tumor control and the minimization of toxic effect to functional parenchyma.Efficacy of treatment is mitigated by the need for ongoing immunosuppression. Yttrium-90 microspheres have been used as a treatment modality both for primary HCC and for pre-transplant management of HCC with promising results. Twenty-two months after liver transplantation for hepatitis C cirrhosis complicated by HCC, a 42-year old man developed recurrence of HCC in his transplant allograft. Treatment of multiple right lobe lesions with anatomic resection and adjuvant chemotherapy was unsuccessful. Multifocal recurrence in the remaining liver allograft was treated with hepatic intra-arterial infusion of yttrium-90 microspheres (SIR-Spheres, Sirtex Medical Inc., Lake Forest, IL, USA). Efficacy was demonstrated by tumor necrosis on imaging and a decrease in alpha-fetoprotein (AFP) level. There were no adverse consequences of initial treatment.

  4. Study on the addition of nonmetal interstitial atoms to the yttrium lattice: formation of YB{sub x}, YC{sub x} and YN{sub x} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Soto, Gerardo; Moreno-Armenta, Maria G.; Reyes-Serrato, Armando [Universidad Nacional Autonoma de Mexico (Mexico)

    2009-01-15

    Yttrium is a rather rare and reactive metal. Due to these characteristics it absorbs important quantities of light atoms in its void spaces. Here, we present a study where B, C and N atoms are gradually incorporated into the octahedral interstices of Y. The idea is to model, by first-principles calculations in a supercell approach, several stages of nonmetal assimilation in the yttrium lattice. In this case to develop YB{sub x}, YC{sub x} and YN{sub x} alloys. This study is limited to the cubic close-packed stacking of Y and chemical compositions in the 0{<=}x{<=}1 range. We found that the studied alloys become thermodynamically favored. The cohesive energies improve with the addition of the nonmetal atoms. Besides, the cell volume and the bulk modulus vary differently for each kind of added atom. We come upon the fact that the ratio between cohesive energy and cell volume is strikingly better for YN{sub x}. We conclude that these alloys permit a remarkable degree of modulation in their properties and electronic structures by means of chemical composition. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Mechanical and Tribological Characterization of Al-Mg2Si Composites After Yttrium Addition and Heat Treatment

    Science.gov (United States)

    Jafari Nodooshan, H. R.; Liu, Wencai; Wu, Guohua; Bahrami, A.; Pech-Canul, M. I.; Emamy, M.

    2014-04-01

    In this study, the effect of heat treatment and yttrium additions on the microstructure, mechanical properties, and tribological behavior of Al-15% Mg2Si cast composites was investigated. The microstructural study revealed the presence of both primary and secondary Mg2Si phases in all composite specimens and also Y-containing intermetallics (Al2Y phases) at higher concentrations. It was also found that Y addition does not change the size and morphology of primary Mg2Si particles considerably, but the pseudo-eutectic Mg2Si changed from a flake-like morphology to fine fibrous or rod-like one. The results show that proper content of Y additions can reduce the amount of Mg2Si phase through dissolving it into the matrix, lead to the precipitation of Al2Y phase and improve the mechanical properties. Modified composites with 0.5% Y exhibited an ultimate tensile strength (UTS) of 290 MPa with an elongation of 4.3%. After exposing the composite to solution treatment at 520 °C for 4 h, the tensile strength of the composite continuously increased with the increase of Y content, and reached the maximum at 1% Y. The maximum UTS and elongation at room temperature for the heat-treated composites are 294 MPa and 7.4%, respectively. In the cast specimen, fracture surfaces are covered by packets with coarse steps, suggesting a brittle mode of failure. Modified composites with 0.5 wt.% Y contain several cracked particles together with a few decohered primary Mg2Si particles. In solution heat-treated state, dimples present at the fracture surface are rather coarse but homogenous, showing a semi-ductile mode of fracture. Wear test results showed that the wear resistance of all specimens increases with the addition of Y up to 0.3 wt.%. Scanning electron microscopic observations of the worn surfaces revealed that the dominant wear mechanism was abrasive wear accompanied by some delamination wear mode.

  6. Harmonic technology versus neodymium-doped yttrium aluminium garnet laser and electrocautery for lung metastasectomy: an experimental study.

    Science.gov (United States)

    Fiorelli, Alfonso; Accardo, Marina; Carelli, Emanuele; Del Prete, Assunta; Messina, Gaetana; Reginelli, Alfonso; Berritto, Daniela; Papale, Ferdinando; Armenia, Emilia; Chiodini, Paolo; Grassi, Roberto; Santini, Mario

    2016-07-01

    We compared the efficacy of non-anatomical lung resections with that of three other techniques: monopolar electrocautery; neodymium-doped yttrium aluminium garnet laser and harmonic technology. We hypothesized that the thermal damage with harmonic technology could be reduced because of the lower temperatures generated by harmonic technology compared with that of other devices. Initial studies were performed in 13 isolated pig lungs for each group. A 1.5-cm capsule was inserted within the lung to mimic a tumour and a total of 25 non-anatomical resections were performed with each device. The damage of the resected lung surface and of the tumour border were evaluated according to the colour (ranging from 0-pink colour to 4-black colour), histological (ranging from Score 0-no changes to Score 3-presence of necrotic tissue) and radiological (ranging from Score 0-isointense T2 signal at magnetic resonance imaging to Score 3-hyperintense T2 signal) criteria. A total of seven non-anatomical resections with harmonic technology were also performed in two live pigs to assess if ex vivo results could be reproducible in live pigs with particular attention to haemostatic and air-tightness properties. In the ex vivo lung, there was a statistical significant difference between depth of thermal damage (P harmonic (0.4 [0.3-0.5]) groups. Electrocautery had a higher depth of thermal damage compared with that of the laser (P = 0.01) and harmonic groups (P = 0.0005). The harmonic group had a less depth of thermal damage than that of the laser group (P = 0.01). Also, histological damages of tumour borders (P harmonic technology. Our experimental data support the resections performed with the use of harmonic technology. The lack of severe tissue alterations could favour healing of parenchyma, assure air tightness and preserve functional lung parenchyma. However, randomized controlled studies are needed in an in vivo model to corroborate our findings. © The Author 2016. Published by

  7. Outcomes and predictors of toxicity after selective internal radiation therapy using yttrium-90 resin microspheres for unresectable hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Andrew eGabrielson

    2015-12-01

    Full Text Available Purpose: We sought to report outcomes and toxicity in patients with hepatocellular carcinoma (HCC who received resin Yttrium-90 Selective Internal Radiation Therapy (90Y-SIRT, and to identify factors associated with declining liver function.Methods: Patients treated with 90Y-SIRT were retrospectively evaluated. Radiographic response was assessed using RECIST 1.1. Median liver progression-free survival (LPFS and overall survival (OS were calculated using the Kaplan-Meier method. Bivariate analysis was used to examine associations between change in Child-Pugh (CP score/class and patient characteristics and treatment parameters.Results: Twenty-seven patients with unresectable HCC underwent SIRT, 52% were CP Class A, 48% were Class B; 11% were BCLC stage B, 89% were stage C. Forty-four percent of patients had portal vein thrombus at baseline. One-third of patients received bilobar treatment. Median activity was 32.1 mCi (range 9.18 – 43.25 and median absorbed dose to the liver was 39.6 Gy (range 13.54 – 67.70. Median LPFS and OS were 2.5 and 11.7 months, respectively. Three-month disease control rate was 63% and 52% in the target lesions and whole liver, respectively.New onset or worsened from baseline clinical toxicities were confined to Grade 1-2 events. However, new or worsened Grade 3-4 laboratory toxicities occurred in 38% of patients at 3 months and 43% of patients at 6 months following SIRT (6 had lymphocytopenia, 3 had hypoalbuminemia, 2 had transaminasemia. After 3 months, 6 patients had worsened in CP score and 5 had worsened in class from baseline. After 6 months, 4 patients had worsened in CP score and 1 had worsened in class from baseline. Pretreatment bilirubinemia was associated with a 2+ increase in CP score within 3 months (P = 0.001 and 6 months (P = 0.039 of 90Y-SIRT. Pretreatment transaminasemia and bilirubinemia were associated with increased CP class within 3 months of SIRT (P = 0.021 and 0.009 respectively.Conclusions: 90Y

  8. Selective intraarterial radionuclide therapy with Yttrium-90 (Y-90 microspheres for unresectable primary and metastatic liver tumors

    Directory of Open Access Journals (Sweden)

    Ozkan Elgin

    2011-08-01

    Full Text Available Abstract Background The aim of this study was to evaluate the success of selective intraarterial radionuclide therapy (SIRT with Yttrium-90 (Y-90 microspheres in liver metastases of different tumors. We also interpreted the contribution of SIRT to survival times according to responder- non responder and hepatic- extra hepatic disease. Methods The clinical and follow-up data of 124 patients who were referred to our department for SIRT between June 2006 and October 2010 were evaluated retrospectively. SIRT has been applied to 78 patients who were suitable for treatment. All the patients had primary liver tumor or unresectable liver metastasis of different malignancies. The treatment was repeated at least one more time in 5 patients to the same or other lobes. Metabolic treatment response evaluated by fluorine-18 fluorodeoxyglucose (F18-FDG positron emission tomography/computed tomography (PET/CT in the 6th week after treatment. F18-FDG PET/CT was repeated in per six weeks periods. The response criterion had been described as at least 20% decrease of SUV value. Also in patients with neuroendocrine tumor serial Gallium-68 (Ga-68 PET/CT was used for evaluation of response. Patients were divided into 2 groups according to their treatment response. Results 68 patients received treatment for the right lobe, seven patients received treatment for the left lobe and 3 patients for both lobes. The mean treatment dose was estimated at 1.62 GBq. In the evaluation of treatment response; 43(55% patients were responder (R and 35 (45% patients were non-responder (NR in the sixth week F18-FDG PET/CT. Mean pretreatment SUVmax value of R group was 11.6 and NR group was 10.7. While only 11 (31% out of 35 NR patients had H disease, 30 (69% out of 43 R patients had H disease (p Conclusions SIRT is a useful treatment method which can contribute to the lengthening of survival times in patients with primary or metastatic unresectable liver malignancies. Also F18-FDG PET

  9. Ultrashort optical pulse generation from a chromium(4)- doped yttrium aluminium garnet tunable solid-state laser

    Science.gov (United States)

    Chang, Yongmao

    2000-11-01

    In this thesis, experimental results of ultrashort pulse generation from Cr4+-doped yttrium aluminium garnet (YAG) laser system are presented. The Cr4+:YAG crystal is a vibronically broadened solid state laser gain medium, which lases at room temperature from 1.34 to 1.58 μm and can be pumped by a Nd:YAG laser at 1.06 μm. Ultrashort pulses from this coherent light source are potentially important in technology applications such as ultrafast fiber-optic communications and time-resolved spectroscopy of narrow- bandgap, semiconductors. It is a practical alternative to more conventional cryogenic colour center lasers at this wavelength such as NaCl:OH- or complex optical parametric oscillators synchronously pumped by a Ti:sapphire laser. The cw power performance of a Cr4+:YAG laser was characterized and several unique properties were identified. A broad tuning range of 210 nm, i.e., from 1345 to 1557 nm, was demonstrated by means of one set of mirrors with useful cw output power of as high as 730 mW at 1.46 μm (with a Nd:YAG pump power of 6.5 W). The lasing action was found to be strongly influenced by the temperature of the crystal and the combined effects of thermal lensing and saturable absorption of the pump beam. The excited-state absorption (ESA) at the pump and lasing wavelengths were investigated both experimentally and theoretically. ESA at the lasing wavelength occurs for the transition from the state 3B2(3T2) to 3E(3T1(F)), while the pump ESA comes from the transition from 3A2(3T2 ) to 3E(3T1(P)). The emission ESA cross sections for the free-running modes were estimated from the laser efficiency data by taking into account the pump and cavity parameters. Ultrashort pulse generation with a Cr4+:YAG laser was investigated using passive mode-locking with a semiconductor quantum well saturable absorber. Self-starting of the laser system was demonstrated using a strained GaInAs/InAlAs saturable Bragg reflector (SBR) with a single prism for dispersion

  10. Lanthanide(III and Yttrium(III Complexes of Benzimidazole-2-Acetic Acid: Synthesis, Characterisation and Effect of La(III Complex on Germination of Wheat

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available The synthesis and characterisation of lanthanide(III and yttrium(III nitrate complexes of benzimidazole-2-acetic acid (HBIA are reported. The complexes have been characterised by elemental analysis, molar conductance, magnetic studies, IR, 1 H NMR, UV-visible, EPR, and TG/DTA studies. They have the stoichiometry [ Ln 3 ( BIA 2 ( NO 3 7 ( H 2 O 4 ]⋅3 H 2 O where Ln=La(III, Pr(III, Nd(II, Sm(III, Eu(III, Gd(III, Tb(III, Dy(III, and Y(III. The effect of La(III complex on germination, coleoptile, and root length of two local varieties of wheat DWR-195 and GW-349 for different treatment periods has been investigated. The complex was found to exhibit enhanced activity, compared to HBIA or metal salt alone at lower treatment periods.

  11. Synthesis by coprecipitation technique and spectroscopic properties of some phosphates. [Yttrium or rare earth and potassium and alkaline earth metal phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Arbus, A.; Duranceau, C.; Zambon, D.; Cousseins, J.C. (Clermont-Ferrand-2 Univ., 63 - Aubiere (FR))

    1991-01-01

    The coprecipitation process has been used for the synthesis of some KBLn(PO{sub 4}){sub 2} compounds where B is an alkaline earth metal and Ln a lanthanide or yttrium. After the gel stage, an amorphous powder is obtained by drying, the thermal evolution of which is studied by X-ray diffraction. The temperature of calcination for the different powders is included in the 500-700{sup 0}C range, lower than that of the classical solid state synthesis, 800-1000{sup 0}C. The final phosphates crystallize with monoclinic or tetragonal symmetry. The spectroscopic properties of some Eu{sup 3+}-doped compounds prepared by coprecipitation technique are reported.

  12. High-efficiency control of spin-wave propagation in ultra-thin yttrium iron garnet by the spin-orbit torque

    Energy Technology Data Exchange (ETDEWEB)

    Evelt, M.; Demidov, V. E., E-mail: demidov@uni-muenster.de [Institute for Applied Physics and Center for Nanotechnology, University of Muenster, 48149 Muenster (Germany); Bessonov, V. [M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, Yekaterinburg 620041 (Russian Federation); Demokritov, S. O. [Institute for Applied Physics and Center for Nanotechnology, University of Muenster, 48149 Muenster (Germany); M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, Yekaterinburg 620041 (Russian Federation); Prieto, J. L. [Instituto de Sistemas Optoelectrónicos y Microtecnologa (UPM), Ciudad Universitaria, Madrid 28040 (Spain); Muñoz, M. [IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), PTM, E-28760 Tres Cantos, Madrid (Spain); Ben Youssef, J. [Laboratoire de Magnétisme de Bretagne CNRS, Université de Bretagne Occidentale, 29285 Brest (France); Naletov, V. V. [Service de Physique de l' État Condensé, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette (France); Institute of Physics, Kazan Federal University, Kazan 420008 (Russian Federation); Loubens, G. de [Service de Physique de l' État Condensé, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette (France); Klein, O. [INAC-SPINTEC, CEA/CNRS and Univ. Grenoble Alpes, 38000 Grenoble (France); Collet, M.; Garcia-Hernandez, K.; Bortolotti, P.; Cros, V.; Anane, A. [Unité Mixte de Physique CNRS, Thales, Univ. Paris Sud, Université Paris-Saclay, 91767 Palaiseau (France)

    2016-04-25

    We study experimentally with submicrometer spatial resolution the propagation of spin waves in microscopic waveguides based on the nanometer-thick yttrium iron garnet and Pt layers. We demonstrate that by using the spin-orbit torque, the propagation length of the spin waves in such systems can be increased by nearly a factor of 10, which corresponds to the increase in the spin-wave intensity at the output of a 10 μm long transmission line by three orders of magnitude. We also show that, in the regime, where the magnetic damping is completely compensated by the spin-orbit torque, the spin-wave amplification is suppressed by the nonlinear scattering of the coherent spin waves from current-induced excitations.

  13. Photoluminescence properties of nanosized strontium-yttrium borate phosphor Sr3Y2(BO3)4:Eu3+ obtained by the sol-gel Pechini method

    Institute of Scientific and Technical Information of China (English)

    A.A. Shyichuk; S. Lis

    2011-01-01

    Mixed strontium-yttrium borate phosphor Sr3Y2(BO3)4 doped with Eu3+ ions was obtained by the sol-gel Pechini method.Crystal structure of the synthesized compound was analyzed by X-ray powder diffraction.Optimal conditions for the synthesis were found.Photophysical properties of the phosphor samples were investigated by collecting excitation and luminescence spectra as well as measuring luminescence lifetime.Judd-Ofelt analysis showed that Eu3+ ions occupied Y3+ sites in the crystalline network.The studied compound showed a red emission with the quantum yield of 54%-55% and can be potentially used as phosphor for plasma display panels and luminescent tubes.

  14. Optimization of image reconstruction for yttrium-90 SIRT on a LYSO PET/CT system using a Bayesian penalized likelihood reconstruction algorithm.

    Science.gov (United States)

    Rowley, Lisa M; Bradley, Kevin M; Boardman, Philip; Hallam, Aida; McGowan, Daniel R

    2016-09-29

    Imaging on a gamma camera with Yttrium-90 ((90)Y) following selective internal radiotherapy (SIRT) may allow for verification of treatment delivery but suffers relatively poor spatial resolution and imprecise dosimetry calculation. (90)Y Positron Emission Tomography (PET) / Computed Tomography (CT) imaging is possible on 3D, time-of-flight machines however images are usually poor due to low count statistics and noise. A new PET reconstruction software using a Bayesian penalized likelihood (BPL) reconstruction algorithm (termed Q.Clear) released by GE was investigated using phantom and patient scans to optimize the reconstruction for post-SIRT imaging and clarify if this leads to an improvement in clinical image quality using (90)Y.

  15. Comparative Evaluation of the Implant Made of Yttrium-partially Stabilized Zirconia and Pure Titanium on Stress Distribution by Anisotropic Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The purpose of this research is to analyze and compare stress distribution patterns around dental implant made of pure titanium and yttrium-partial stabilized zirconia (YPSZ) in anisotropic versus isotropic finite element method under vertical and oblique loads. Although the properties of implant and crown were changed,similar stress distribution and close stress level were observed in two different implant finite element models. The stress values were a little lower in the YPSZ model. In the bone, anisotropy increased the stress values by 30%-70% in the isotropic cases. The YPSZ implant could be more valuable choice for implant because of esthetic requirement. Anisotropy had subtle, yet significant effects on the stress level.

  16. Dielectric relaxation and electronic spectroscopy of double potassium yttrium tetraoxophosphate(V) K 3Y(PO 4) 2 doped by neodymium and europium ions

    Science.gov (United States)

    Szulia, S.; Kosmowska, M.; Kołodziej, H. A.; Sobczyk, M.; Czupińska, G.

    2011-12-01

    The paper presents the results of our investigation on electric properties of double potassium yttrium tetraoxophosphate(V) doped by lanthanide ions K 3Y (1-x)Ln x(PO 4) 2 ( x = 0.01, 0.05, Ln = Eu 3+, Nd 3+). Electric permittivity and dielectric loss measurements have been performed on polycrystalline samples in the temperature range -50 °C to +120 °C and frequency range 1 kHz-1 MHz by means of HP 4282A impedance meter. The frequency and temperature dependence of electric properties were analyzed by theoretical models of dielectric relaxation in order to obtain information abut molecular dynamic of our solids in external electric field.

  17. Investigation of concentration-dependence of thermodynamic properties of lanthanum, yttrium, scandium and terbium in eutectic LiCl-KCl molten salt

    Science.gov (United States)

    Wang, Yafei; Zhou, Wentao; Zhang, Jinsuo

    2016-09-01

    Thermodynamic properties of rare earth metals in LiCl-KCl molten salt electrolyte are crucial to the development of electrochemical separation for the treatment of used nuclear fuels. In the present study, activity coefficient, apparent potential, and diffusion coefficient of lanthanum, yttrium, scandium, and terbium in the molten salt (58 at% LiCl and 42 at% KCl) were calculated by the method of molecular dynamics simulation up to a concentration around 3 at% at temperatures of 723 K and 773 K. It was found that the activity coefficient and the apparent potential increase with the species concentration while diffusion coefficient shows a trend of increase followed by decrease. The calculated results were validated by available measurement data of dilution cases. This research extends the range of data to a wide component and would provide further insight to the pyroprocessing design and safeguards.

  18. Effect of the ion-beam bombardment and annealing temperature on sol-gel derived yttrium aluminum oxide film as liquid crystal alignment layer

    Science.gov (United States)

    Jeong, Hae-Chang; Heo, Gi-Seok; Kim, Eun-Mi; Lee, Ju Hwan; Han, Jeong-Min; Seo, Dae-Shik

    2017-02-01

    We demonstrated a homogeneous liquid-crystal (LC) alignment state on yttrium aluminum oxide (YAlO) films, where the alignment was induced by ion-beam (IB) irradiation. Topographical analysis was performed by atomic force microscopy as a function of annealing temperature. Higher annealing temperatures yielded a smoother surface, accompanied by reduced light scattering. Transparency in the visible region increased on the surface fabricated at higher annealing temperatures. LC alignment mechanism was determined by X-ray diffraction (XRD) analysis. Moreover, IB-irradiated YAlO films annealed at temperatures greater than 200 °C exhibited good thermal stability and low capacitance-voltage hysteresis. The IB-irradiated YAlO films are suitable as alternative alignment layers in advanced LC display applications.

  19. Doped Yttrium Chromite-Ceria Composite as a Redox-Stable and Sulfur-Tolerant Anode for Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Kyung J.; Coyle, Christopher A.; Marina, Olga A.

    2011-12-11

    A Ca- and Co-doped yttrium chromite (YCCC) - samaria-doped ceria (SDC) composite was studied in relation to a potential use as a solid oxide fuel cell (SOFC) anode material. Tests performed using the yttria-stabilized zirconia (YSZ) electrolyte-supported cells revealed that the electrocatalytic activity of the YCCC-SDC anode towards hydrogen oxidation at 800 C was comparable to that of the Ni-YSZ anode. In addition, the YCCC-SDC anode exhibited superior sulfur tolerant characteristics showing less than 10% increase in a polarization resistance, fully reversible, upon exposure to 20 ppm H2S at 800 C. No performance degradation was observed during multiple reduction-oxidation (redox) cycles when the anode was intentionally exposed to the air environment followed by the reduction in hydrogen. The redox tolerance of the YCCC-SDC anode was attributed to the dimensional and chemical stability of the YCCC exhibiting minimal isothermal chemical expansion upon redox cycling.

  20. Enhanced fluorescence sensitivity by coupling yttrium-analyte complexes and three-way fast high-performance liquid chromatography data modeling

    Energy Technology Data Exchange (ETDEWEB)

    Alcaraz, Mirta R.; Culzoni, María J., E-mail: mculzoni@fbcb.unl.edu.ar; Goicoechea, Héctor C., E-mail: hgoico@fbcb.unl.edu.ar

    2016-01-01

    The present study reports a sensitive chromatographic method for the analysis of seven fluoroquinolones (FQs) in environmental water samples, by coupling yttrium-analyte complex and three-way chromatographic data modeling. This method based on the use of HPLC-FSFD does not require complex or tedious sample treatments or enrichment processes before the analysis, due to the significant fluorescence increments of the analytes reached by the presence of Y{sup 3+}. Enhancement achieved for the FQs signals obtained after Y{sup 3+} addition reaches 103- to 1743-fold. Prediction results corresponding to the application of MCR-ALS to the validation set showed relative error of prediction (REP%) values below 10% in all cases. A recovery study that includes the simultaneous determination of the seven FQs in three different environmental aqueous matrices was conducted. The recovery studies assert the efficiency and the accuracy of the proposed method. The LOD values calculated are in the order of part per trillion (below 0.5 ng mL{sup −1} for all the FQs, except for enoxacin). It is noteworthy to mention that the method herein proposed, which does not include pre-concentration steps, allows reaching LOD values in the same order of magnitude than those achieved by more sophisticated methods based on SPE and UHPLC-MS/MS. - Highlights: • Highly sensitive method for the analysis of seven fluoroquinolones. • Coupling of yttrium-analyte complex and three-way modeling. • Complex or tedious sample treatments or enrichment processes are nor required. • Accuracy on the quantitation of fluoroquinolones in real water river samples.