WorldWideScience

Sample records for transparent lead lanthanum

  1. Phase transformations in lead zirconate-titanate doped with lanthanum

    Energy Technology Data Exchange (ETDEWEB)

    Ishchuk, V M; Morozov, E M

    1979-07-01

    Presented are the results of studies on the character of phase transitions of the lead-lanthanum zirconate-titanate (LLZT) system. The replacement of lead by lanthanum leads to the expansion of the region of antisegnetoelectric (ASE) states of solid solutions of lead zirconate-titanate (LZT) in the direction of PbTiO/sub 3/ concentration growth. An intermediate region is revealed between segnetoelectric (SE) and ASE states, material properties in which depend on their prehistory: annealed samples are in the ASE state, whereas the application of electric field exceeding some critical value induces the SE state. A family of phase diagrams obtained at consequent replacement of lead by lanthanum permits to identify phase states in any series of LLZT with a constant ratio of Zr:Ti, in the x/65/35 series in particular. Thermally depolarized state of materials of this series at x<6.5 is shown to be antisegnetoelectric at all the temperatures below the Curie point Tsub(c), and heating causes phase transition of ASE..-->..PE (paraelectric state) at Tsub(c). Polarized samples being heated, a successiveness of phase transitions of SE..-->..ASE takes place at T/sub 0/, and that of ASE reversible PE at Tsub(C) (Tsub(0)..ASE phase transition in the LZT system.

  2. Lanthanum

    Science.gov (United States)

    ... levels of phosphate in the blood can cause bone problems. Lanthanum is in a clsas of medications ... to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in ...

  3. Characterization of dense lead lanthanum titanate ceramics prepared from powders synthesized by the oxidant peroxo method

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Alexandre H. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Departamento de Quimica, UFSCar-Universidade Federal de Sao Carlos, Rod.Washington Luis km 235, CP 676 Sao Carlos, SP 13565-905 (Brazil); Souza, Flavio L., E-mail: flavio.souza@ufabc.edu.br [Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adelia 166, Bangu, Santo Andre, SP 09210-170 (Brazil); Chiquito, Adenilson J., E-mail: chiquito@df.ufscar.br [Departamento de Fisica, UFSCar-Federal University of Sao Carlos, Rod.Washington Luis km 235, CP 676 Sao Carlos, SP 13565-905 (Brazil); Longo, Elson, E-mail: elson@iq.unesp.br [Instituto de Quimica de Araraquara, UNESP-Universidade Estadual Paulista, Rua Francisco Degni, CP 355 Araraquara, SP 14801-907 (Brazil); Leite, Edson R., E-mail: derl@power.ufscar.br [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Departamento de Quimica, UFSCar-Universidade Federal de Sao Carlos, Rod.Washington Luis km 235, CP 676 Sao Carlos, SP 13565-905 (Brazil); Camargo, Emerson R., E-mail: camargo@ufscar.br [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Departamento de Quimica, UFSCar-Universidade Federal de Sao Carlos, Rod.Washington Luis km 235, CP 676 Sao Carlos, SP 13565-905 (Brazil)

    2010-12-01

    Nanosized powders of lead lanthanum titanate (Pb{sub 1-x}La{sub x}TiO{sub 3}) were synthesized by means of the oxidant-peroxo method (OPM). Lanthanum was added from 5 to 30% in mol through the dissolution of lanthanum oxide in nitric acid, followed by the addition of lead nitrate to prepare a solution of lead and lanthanum nitrates, which was dripped into an aqueous solution of titanium peroxo complexes, forming a reactive amorphous precipitate that could be crystallized by heat treatment. Crystallized powders were characterized by FT-Raman spectroscopy and X-ray powder diffraction, showing that tetragonal perovskite structure is obtained for samples up to 25% of lanthanum and cubic perovskite for samples with 30% of lanthanum. Powders containing 25 and 30% in mol of lanthanum were calcined at 700 deg. C for 2 h, and in order to determine the relative dielectric permittivity and the phase transition behaviour from ferroelectric-to-paraelectric, ceramic pellets were prepared and sintered at 1100 or 1150 deg. C for 2 h and subjected to electrical characterization. It was possible to observe that sample containing 25% in mol of La presented a normal behaviour for the phase transition, whereas the sample containing 30% in mol of La presented a diffuse phase transition and relaxor behaviour.

  4. Characterization of dense lead lanthanum titanate ceramics prepared from powders synthesized by the oxidant peroxo method

    International Nuclear Information System (INIS)

    Pinto, Alexandre H.; Souza, Flavio L.; Chiquito, Adenilson J.; Longo, Elson; Leite, Edson R.; Camargo, Emerson R.

    2010-01-01

    Nanosized powders of lead lanthanum titanate (Pb 1-x La x TiO 3 ) were synthesized by means of the oxidant-peroxo method (OPM). Lanthanum was added from 5 to 30% in mol through the dissolution of lanthanum oxide in nitric acid, followed by the addition of lead nitrate to prepare a solution of lead and lanthanum nitrates, which was dripped into an aqueous solution of titanium peroxo complexes, forming a reactive amorphous precipitate that could be crystallized by heat treatment. Crystallized powders were characterized by FT-Raman spectroscopy and X-ray powder diffraction, showing that tetragonal perovskite structure is obtained for samples up to 25% of lanthanum and cubic perovskite for samples with 30% of lanthanum. Powders containing 25 and 30% in mol of lanthanum were calcined at 700 deg. C for 2 h, and in order to determine the relative dielectric permittivity and the phase transition behaviour from ferroelectric-to-paraelectric, ceramic pellets were prepared and sintered at 1100 or 1150 deg. C for 2 h and subjected to electrical characterization. It was possible to observe that sample containing 25% in mol of La presented a normal behaviour for the phase transition, whereas the sample containing 30% in mol of La presented a diffuse phase transition and relaxor behaviour.

  5. Molten salt synthesis of lead lanthanum zirconate titanate ceramic powders

    International Nuclear Information System (INIS)

    Cai Zongying; Xing Xianran; Li Lu; Xu Yeming

    2008-01-01

    Lead lanthanum zirconate titanate (Pb 0.95 La 0.03 )(Zr 0.52 Ti 0.48 )O 3 (PLZT) was synthesized by one step molten salt method with the starting materials of PbC 2 O 4 , La 2 O 3 , ZrO(NO 3 ) 2 .2H 2 O and TiO 2 in the NaCl-KCl eutectic mixtures in the temperature range of 700-1000 deg. C. The single phase of (Pb 0.95 La 0.03 )(Zr 0.52 Ti 0.48 )O 3 powders was prepared at a temperature as low as 850 deg. C for 5 h. The effects of process parameters, such as soaking temperature and time, salt species, and the amount of flux with respect to the starting materials were investigated. The growth process of the PLZT particles in the molten salt undergoes a transition from a diffusion controlled mechanism to an interfacial reaction controlled mechanism at 900 deg. C

  6. Nanosized lead lanthanum titanate (PLT) ceramic powders synthesized by the oxidant peroxo method

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, Emerson R. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Department of Chemistry, UFSCar-Federal University of Sao Carlos, Rod.Washingtin Luis km 235, CP 676, Sao Carlos SP 13565-9905 (Brazil)], E-mail: camargo@ufscar.br; Barrado, Cristiano M. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Department of Chemistry, UFSCar-Federal University of Sao Carlos, Rod.Washingtin Luis km 235, CP 676, Sao Carlos SP 13565-9905 (Brazil); Ribeiro, Caue [EMBRAPA Instrumentacao Agropecuaria, Rua XV de Novembro 1452, Sao Carlos SP 13560-970 (Brazil)], E-mail: caue@cnpdia.embrapa.br; Longo, Elson [Department of Biochemistry, Chemistry Institute of Araraquara, UNESP-Sao Paulo State University, Rua Francisco Degni, CP 355, Araraquara SP 14801-907 (Brazil)], E-mail: elson@iq.unesp.br; Leite, Edson R. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Department of Chemistry, UFSCar-Federal University of Sao Carlos, Rod.Washingtin Luis km 235, CP 676, Sao Carlos SP 13565-9905 (Brazil)], E-mail: derl@power.ufscar.br

    2009-05-05

    For the first time it is reported the synthesis of lead titanate modified with rare earth by the oxidant-peroxo method (OPM). Lanthanum was added up to 20% in mol through the dissolution of lanthanum oxide in nitric acid, followed by the addition of a solution of lead and lanthanum nitrate into an aqueous solution of titanium peroxo complexes. The amorphous precipitate formed was heat-treated at different temperatures in the range from 400 to 900 deg. C for crystallization. Powders were characterized by Raman spectroscopy and X-ray diffraction. Tetragonal perovskite structure was observed for the samples up to 15% of lanthanum substitution and cubic perovskite for sample with 20% of lanthanum. Crystallographic domains calculated by Scherrer equation showing a probable suppression of the crystallite growth in function of lanthanum content. It was observed shifting to lower frequencies of Raman modes in the range between 100 and 400 cm{sup -1} and the vanishing of the A1(2TO) and E(1LO) modes could be attributed to transition phase from tetragonal to cubic. Electronic microscopy image revealed that the powders annealed at height temperature are spherical with sharp size distribution.

  7. Nanosized lead lanthanum titanate (PLT) ceramic powders synthesized by the oxidant peroxo method

    International Nuclear Information System (INIS)

    Camargo, Emerson R.; Barrado, Cristiano M.; Ribeiro, Caue; Longo, Elson; Leite, Edson R.

    2009-01-01

    For the first time it is reported the synthesis of lead titanate modified with rare earth by the oxidant-peroxo method (OPM). Lanthanum was added up to 20% in mol through the dissolution of lanthanum oxide in nitric acid, followed by the addition of a solution of lead and lanthanum nitrate into an aqueous solution of titanium peroxo complexes. The amorphous precipitate formed was heat-treated at different temperatures in the range from 400 to 900 deg. C for crystallization. Powders were characterized by Raman spectroscopy and X-ray diffraction. Tetragonal perovskite structure was observed for the samples up to 15% of lanthanum substitution and cubic perovskite for sample with 20% of lanthanum. Crystallographic domains calculated by Scherrer equation showing a probable suppression of the crystallite growth in function of lanthanum content. It was observed shifting to lower frequencies of Raman modes in the range between 100 and 400 cm -1 and the vanishing of the A1(2TO) and E(1LO) modes could be attributed to transition phase from tetragonal to cubic. Electronic microscopy image revealed that the powders annealed at height temperature are spherical with sharp size distribution.

  8. Small polaron conduction in lead modified lanthanum ferrite ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Bhargav, K.K.; Ram, S.; Majumder, S.B., E-mail: subhasish@matsc.iitkgp.ernet.in

    2015-07-25

    Highlights: • La{sub 0.8}Pb{sub 0.2}FeO{sub 3} (ε{sub r} ∼ 30,000) shows higher dielectric constant than LaFeO{sub 3} (∼14,000). • Lower A-site dopant content, the dielectric maxima shift to higher temperature. • The frequency dependence of ε{sub r} and tan δ vs. temperature exhibit CDC like behavior. • R{sub g} and R{sub gb} of Pb modified LaFeO{sub 3} follow small polaron hopping conduction model. - Abstract: In the present work we have illustrated the physics of the electrical characteristics of nanocrystalline La{sub 1−x}Pb{sub x}FeO{sub 3,} (0 ⩽ x ⩽ 0.2) powder prepared using auto-combustion synthesis. The effect of lead doping on the dielectric, impedance and ac conductivity characteristics of lanthanum ferrite has systematically been investigated. The synthesized powders were phase pure and crystallized into centro-symmetric Pnma space group. As compared to pure LaFeO{sub 3} ceramics (dielectric constant ∼ 14,000), the dielectric constant is grossly increased (∼30,000) in Pb doped LaFeO{sub 3}. The temperature dependence of dielectric constant of 10.0 at.% Pb doped LaFeO{sub 3} exhibits dielectric maxima similar to that observed in ferroelectric ceramics with non-centrosymmetric point group. For La{sub 0.8}Pb{sub 0.2}FeO{sub 3} ceramics, the frequency dependence of the dielectric constant and loss tangent at various temperatures (300–450 K) exhibit typical colossal dielectric constant (CDC) like behavior. From the impedance spectroscopy we have estimated the grain and grain boundary resistance and capacitance of Pb doped LaFeO{sub 3} that follow a small polaron hopping conduction model. Long range movement of the charge carriers govern the CDC behavior.

  9. Improvement of the optoelectronic properties of tin oxide transparent conductive thin films through lanthanum doping

    Energy Technology Data Exchange (ETDEWEB)

    Mrabet, C., E-mail: chokri.mrabet@hotmail.com; Boukhachem, A.; Amlouk, M.; Manoubi, T.

    2016-05-05

    This work highlights some physical investigations on tin oxide thin films doped with different lanthanum content (ratio La–to-Sn = 0–3%). Such doped thin films have been successfully grown by spray pyrolysis onto glass substrates at 450 °C. X-ray diffraction (XRD) patterns showed that SnO{sub 2}:La thin films were polycrystalline with tetragonal crystal structure. The preferred orientation of crystallites for undoped SnO{sub 2} thin film was along (110) plane, whereas La-doped ones have rather preferential orientations along (200) direction. Although the grain size values exhibited a decreasing tendency with increasing doping content confirming the role of La as a grain growth inhibitor, dislocation density and microstrain values showed an increasing tendency. Also, Raman spectroscopy shows the bands corresponding to the tetragonal structure for the entire range of La doping. The same technique confirms the presence of La{sub 2}O{sub 3} as secondary phase. Moreover, SEM images showed a porous architecture with presence of big clusters with different sizes and shapes resulting from the agglomeration of small grains round shaped. Photoluminescence spectra of SnO{sub 2}:La thin films exhibit a decrease in the emission intensity with La concentration due to the decrease in grain size. Optical transmittance spectra of the films showed high transparency (∼80%) in the visible region. The dispersion of the refractive index is discussed using both Cauchy model and Wemple–Di-Domenico method. The optical band gap values vary slightly with La doping and were found to be around 3.8 eV. It has been found that La doping causes a pronounced decrease in the sheet resistance by up to two orders of magnitude and allows improving the Haacke's figure of merit (Φ) of the sprayed thin films. Moreover, we have introduced for a first time a new figure of merit for qualifying photo-thermal conversion applications. The obtained high conducting and transparent SnO{sub 2}:La

  10. Effect of lead dioxide on the radiation decomposition of hydrated lanthanum nitrate (Preprint No. RES-05)

    International Nuclear Information System (INIS)

    Patil, S.F.; Bedekar, A.G.; Chiplunkar, N.R.

    1988-02-01

    The rate of radiation induced decomposition of lanthanum nitrate is found to increase in the presence of lead dioxide as a heterophase impurity. Further, the rate also increases with increasing mole percent of the oxide. The results are explained on the basis of energy transfer processes taking place at the interface between nitrate and oxide crystals. (aut hor). 9 refs

  11. Spectroscopic properties of Er/Nd co-doped yttrium lanthanum oxide transparent ceramics pumped at 980 nm

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Yingjie; Yang, Qiuhong, E-mail: yangqiuhong@shu.edu.cn; Gui, Yan; Yuan, Ye; Lu, Qing

    2016-05-15

    (Er{sub 0.01}Nd{sub x}Y{sub 0.89-x}La{sub 0.1}){sub 2}O{sub 3} (x = 0, 0.001, 0.002, 0.005, 0.01) transparent ceramics were prepared by conventional ceramic processing. The Nd{sup 3+} content dependencies of mid-infrared, near infrared and up-conversion emission of Er{sup 3+} pumped at 980 nm were fully presented. Mechanism of energy transfer between Er{sup 3+} and Nd{sup 3+} was also demonstrated. The results showed that co-doping 0.1 at% Nd{sup 3+} into 1 at% Er{sup 3+} doped yttrium lanthanum oxide transparent ceramic enhanced the 2.7 μm emission significantly and meanwhile suppressed the 1.5 μm emission effectively which indicated an improvement in population inversion between Er:{sup 4}I{sub 11/2} and Er:{sup 4}I{sub 13/2}. Moreover, green up-conversion emission of Er{sup 3+} ion also showed a great improvement by co-doping 0.1 at% Nd{sup 3+}. Those great results were attributed to energy recycle from Er:{sup 4}I{sub 13/2} to Er:{sup 4}I{sub 11/2}. The energy recycle was mainly built by the two energy transfer between Er{sup 3+} and Nd{sup 3+} (one is from Er to Nd, another is in opposite way). So, Er/Nd co-doped yttrium lanthanum oxide transparent ceramic with Nd in low concentration can be considered as a promising laser material for ∼3 μm and up-conversion laser application. - Highlights: • (Er{sub 0.01}Nd{sub x}Y{sub 0.89-x}La{sub 0.1}){sub 2}O{sub 3} transparent ceramics were prepared. • The emission of 2.7 μm of Er{sup 3+} ion was significantly enhanced as x was 0.001. • The emission of 1.5 μm of Er{sup 3+} ion was suppressed greatly by co-doping Nd{sup 3+} ion. • Mechanism of Er–Nd energy transfer was discussed by the energy sketch.

  12. Influence of tellurite on lifetime for samarium doped lanthanum lead borate glass

    Science.gov (United States)

    Madhu, A.; Eraiah, B.

    2018-04-01

    Samarium substituted tellurium lanthanum lead borate glass is prepared using melt quenching technique. Luminescence spectra have been recorded upon excitation with 402 nm various transitions from 4G5/2 level, for samarium doped tellurite glasses are studied and also lifetime for all the samples exhibit single exponential behaviour of decay curve. Luminescence spectra of present glasses show quenching effect due to cross-relation channels of samarium ions. The lifetime of glass samples decrease as the tellurite concentration is decreased. So, it evidences that to attain longer lifetime for lasing material one can tune the host by selecting concentration of tellurite.

  13. The effect of physiologic aqueous solutions on the perovskite material lead-lanthanum-zirconium titanate (PLZT)

    Science.gov (United States)

    Foster, William J.; Meen, James K.; Fox, Donald A.

    2016-01-01

    Context Perovskite compounds, including Lead-Lanthanum-Zirconium Titanate (PLZT), have wide technological application because of their unique physical properties. The use of PLZT in neuro-prosthetic systems, such as retinal implants, have been discussed in a number of publications. Since inorganic lead is a retinotoxic compound that produces retinal degeneration, the long-term stability of PLZT in aqueous biological solutions must be determined. Objective We evaluated the stability and effects of prolonged immersion of a PLZT-coated crystal in a buffered balanced salt solution. Materials and Methods Scanning Electron Microscopy and Electron Dispersive Spectroscopy (EDS) using a JEOL JSM 5410 microscope equipped with EDS were utilized to evaluate the samples before and after prolonged immersion. Results We found that lead and other constituents of PLZT leached into the surrounding aqueous medium. Discussion By comparing the unit cell of PLZT with that of CaTiO3, which has been found to react with aqueous fluids, Lead is in the same site in PLZT as Ca is in CaTiO3. It is thus reasonable that PLZT will react with aqueous solutions. Conclusion The results suggest that PLZT must either be coated with a protective layer or is not appropriate for long-term in vivo or in vitro biological applications. PMID:22697294

  14. Develop techniques for ion implantation of PLZT [lead-lanthanum-zirconate-titanate] for adaptive optics

    International Nuclear Information System (INIS)

    Batishko, C.R.; Brimhall, J.L.; Pawlewicz, W.T.; Stahl, K.A.; Toburen, L.H.

    1987-09-01

    Research was conducted at Pacific Northwest Laboratory to develop high photosensitivity adaptive optical elements utilizing ion implanted lanthanum-doped lead-zirconate-titanate (PLZT). One centimeter square samples were prepared by implanting ferroelectric and anti-ferroelectric PLZT with a variety of species or combinations of species. These included Ne, O, Ni, Ne/Cr, Ne/Al, Ne/Ni, Ne/O, and Ni/O, at a variety of energies and fluences. An indium-tin oxide (ITO) electrode coating was designed to give a balance of high conductivity and optical transmission at near uv to near ir wavelengths. Samples were characterized for photosensitivity; implanted layer thickness, index of refraction, and density; electrode (ITO) conductivity; and in some cases, residual stress curvature. Thin film anti-ferroelectric PLZT was deposited in a preliminary experiment. The structure was amorphous with x-ray diffraction showing the beginnings of a structure at substrate temperatures of approximately 550 0 C. This report summarizes the research and provides a sampling of the data taken during the report period

  15. Effect of compositional variations in the lead lanthanum zirconate stannate titanate system on electrical properties

    International Nuclear Information System (INIS)

    Markowski, K.; Park, S.E.; Yoshikawa, Shoko; Cross, L.E.

    1996-01-01

    The purpose of this work was to evaluate the effect of compositional modifications on the electrical properties of lead lanthanum zirconate stannate titanate (PLZST) ceramics, as well as to examine their electrically induced phase-change behavior. Variations in the Ti:Sn ratio were evaluated. Increased Ti 4+ content produced the following: decreased switching field, related to an increased antiferroelectric-ferroelectric (AFE-FE) transition temperature; constant hysteresis (ΔE) correlated with a constant temperature of the maximum dielectric constant (T max ); a sharper dielectric-constant maximum peak; and increased room-temperature dielectric constant (K). Variations in the Zr:Sn ratio also were evaluated. Increased Zr 4+ content produced the following: increased hysteresis with increased T max , decreased maximum dielectric constant, and decreased switching field with increased AFE-FE transition temperature (T AFE-FE ). From these results, with respect to compositional modifications, the AFE-FE switching field (E AFE-FE ) and ΔE were observed to be dependent strongly on T AFE-FE and T max , respectively. Negligible change existed in the strain achievable at the switching field, which remained constant for all compositions at ∼0.16%. The significance of this research was the ability demonstrated to tailor the properties of phase-change materials through compositional modifications

  16. Nd3+-doped lanthanum lead boro-tellurite glass for lasing and amplification applications

    Science.gov (United States)

    Madhu, A.; Eraiah, B.; Manasa, P.; Srinatha, N.

    2018-01-01

    Nd3+-doped lanthanum lead boro-tellurite glass samples were prepared by conventional melt quenching method and their structural, thermal, fluorescence, and decay times of the glasses were investigated. Prepared glass samples exhibits amorphous nature and shows good thermal stability in the temperature range of 100-800 °C. Judd-Ofelt (JO) analysis was carried out and the intensity parameters (Ωλ = 2, 4, 6) also spontaneous radiative probability and stimulated-.emission cross-sections were estimated. The magnitude of Ωλ confirms the covalency nature. The near infrared emission spectra were measured by 808 nm excitation in which the emission intensity is found to be high at 1060 nm for the 4F3/2 → 4F11/2 transition. The stimulated cross section, effective band width and branching ratios are found to be 8.910 × 10-20 cm2, 21.57 nm and 53.72 % respectively, for 4F3/2 → 4F11/2 transition. The derived gain bandwidth, figure of merit, threshold and saturation intensity found to be comparable to some of the glass systems. Furthermore, the time decay rate found to decrease from 100 μs to 27 μs when the concentration increased from 0.1 to 3.0 mol% of Nd3+ ions and also all follow the single exponential behaviour which is attributed to the self quenching effect due to the cross-relaxation channels.

  17. Ferroelectric and Piezoelectric properties of (111) oriented lanthanum modified lead zirconate titanate film

    International Nuclear Information System (INIS)

    Dutta, Soma; Antony Jeyaseelan, A.; Sruthi, S.

    2014-01-01

    Lanthanum modified lead zirconate titanate (PLZT) thick film with molecular formula of Pb 0.92 La 0.08 (Zr 0.52 Ti 0.48 ) 0.98 O 3 was grown preferentially along (111) direction on Pt/SiO 2 /Si (platinum/silicon oxide/silicon) substrate by spin coating of chemical solution. The directional growth of the film was facilitated by platinum (Pt) (111) template and rapid thermal annealing. X-ray diffraction pattern and atomic force microscopy revealed the preferential growth of the PLZT film. The film was characterized for ferroelectric and detailed piezoelectric properties in a parallel plate capacitor (metal–PLZT–metal) configuration. Ferroelectric characterization of the film showed saturated hysteresis loop with remanent polarization and coercive electric field values of 10.14 μC/cm 2 and 42 kV/cm, respectively, at an applied field of 300 kV/cm. Longitudinal piezoelectric coefficient (d 33,f ) was measured by employing converse piezoelectric effect where electrical charge response and displacement were measured with electrical voltage excitation on the sample electrodes. The effective transverse piezoelectric coefficient (e 31,f ) was derived from charge measurement with an applied mechanical excitation strain by using the four point bending method. d 33,f and e 31,f coefficients of PLZT films were found to be 380 pm/V and − 0.831 C/m 2 respectively. - Highlights: • PLZT (111) film is prepared by spin coating of chemical sol on Pt (111) template. • Piezoelectric d 33 value (380 pm/V) of PLZT film is found 20% higher than PZT. • Transverse piezocoefficient e 31,f of PLZT film is reported for the first time

  18. Ferroelectric and Piezoelectric properties of (111) oriented lanthanum modified lead zirconate titanate film

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Soma, E-mail: som@nal.res.in; Antony Jeyaseelan, A.; Sruthi, S.

    2014-07-01

    Lanthanum modified lead zirconate titanate (PLZT) thick film with molecular formula of Pb{sub 0.92}La{sub 0.08}(Zr{sub 0.52}Ti{sub 0.48}){sub 0.98}O{sub 3} was grown preferentially along (111) direction on Pt/SiO{sub 2}/Si (platinum/silicon oxide/silicon) substrate by spin coating of chemical solution. The directional growth of the film was facilitated by platinum (Pt) (111) template and rapid thermal annealing. X-ray diffraction pattern and atomic force microscopy revealed the preferential growth of the PLZT film. The film was characterized for ferroelectric and detailed piezoelectric properties in a parallel plate capacitor (metal–PLZT–metal) configuration. Ferroelectric characterization of the film showed saturated hysteresis loop with remanent polarization and coercive electric field values of 10.14 μC/cm{sup 2} and 42 kV/cm, respectively, at an applied field of 300 kV/cm. Longitudinal piezoelectric coefficient (d{sub 33,f}) was measured by employing converse piezoelectric effect where electrical charge response and displacement were measured with electrical voltage excitation on the sample electrodes. The effective transverse piezoelectric coefficient (e{sub 31,f}) was derived from charge measurement with an applied mechanical excitation strain by using the four point bending method. d{sub 33,f} and e{sub 31,f} coefficients of PLZT films were found to be 380 pm/V and − 0.831 C/m{sup 2} respectively. - Highlights: • PLZT (111) film is prepared by spin coating of chemical sol on Pt (111) template. • Piezoelectric d{sub 33} value (380 pm/V) of PLZT film is found 20% higher than PZT. • Transverse piezocoefficient e{sub 31,f} of PLZT film is reported for the first time.

  19. Influence of crystal phases on electro-optic properties of epitaxially grown lanthanum-modified lead zirconate titanate films

    Science.gov (United States)

    Masuda, Shin; Seki, Atsushi; Masuda, Yoichiro

    2010-02-01

    We describe here how we have improved the crystal qualities and controlled the crystal phase of the lanthanum-modified lead zirconate titanate (PLZT) film without changing the composition ratio using an oxygen-pressure crystallization process. A PLZT film deposited on a SrTiO3 substrate with the largest electro-optic (EO) coefficient of 498 pm/V has been achieved by controlling the crystal phase of the film. Additionally, a fatigue-free lead zirconate titanate (PZT) capacitor with platinum electrodes has been realized by reducing the oxygen vacancies in the films.

  20. Thickness effect on the structure, grain size, and local piezoresponse of self-polarized lead lanthanum zirconate titanate thin films

    Energy Technology Data Exchange (ETDEWEB)

    Melo, M.; Araújo, E. B., E-mail: eudes@dfq.feis.unesp.br [Departamento de Física e Química, Faculdade de Engenharia de Ilha Solteira, UNESP—Univ. Estadual Paulista, 15385-000 Ilha Solteira, SP (Brazil); Shvartsman, V. V. [Institute for Materials Science, University Duisburg-Essen, 45141 Essen (Germany); Shur, V. Ya. [Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation); Kholkin, A. L. [Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation); Department of Physics and CICECO—Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro (Portugal)

    2016-08-07

    Polycrystalline lanthanum lead zirconate titanate (PLZT) thin films were deposited on Pt/TiO{sub 2}/SiO{sub 2}/Si substrates to study the effects of the thickness and grain size on their structural and piezoresponse properties at nanoscale. Thinner PLZT films show a slight (100)-orientation tendency that tends to random orientation for the thicker film, while microstrain and crystallite size increases almost linearly with increasing thickness. Piezoresponse force microscopy and autocorrelation function technique were used to demonstrate the existence of local self-polarization effect and to study the thickness dependence of correlation length. The obtained results ruled out the bulk mechanisms and suggest that Schottky barriers near the film-substrate are likely responsible for a build-in electric field in the films. Larger correlation length evidence that this build-in field increases the number of coexisting polarization directions in larger grains leading to an alignment of macrodomains in thinner films.

  1. Grain growth kinetics and electrical properties of lanthanum modified lead zirconate titanate (9/65/35) based ferroelectric ceramics

    International Nuclear Information System (INIS)

    Roca, R. Alvarez; Guerrero, F.; Botero, E. R.; Garcia, D.; Eiras, J. A.; Guerra, J. D. S.

    2009-01-01

    The influence of the microstructural characteristics on the dielectric and electrical properties has been investigated for Nd 3+ doped lanthanum modified lead zirconate titanate ferroelectric ceramics, obtained by the conventional solid-state reaction method, by taking into account different sintering conditions. The grain growth mechanism has been investigated and a cubic-type grain growth law was observed for samples with grain size varying from 1.00 up to 2.35 μm. The porosity and grain size dependences of the phase transition parameters, such as the maximum dielectric permittivity and its corresponding temperature (ε m and T m , respectively) were also investigated. The ac conductivity analyses followed the universal Jonscher law. The behavior of the frequency exponent (s) was analyzed through the correlated barrier hopping model. Both ac and dc conductivity results have been correlated with the observed microstructural features

  2. The effect of physiologic aqueous solutions on the perovskite material lead-lanthanum-zirconium titanate (PLZT): potential retinotoxicity.

    Science.gov (United States)

    Foster, William J; Meen, James K; Fox, Donald A

    2013-03-01

    Perovskite compounds, including lead-lanthanum-zirconium titanate (PLZT), have wide technological application because of their unique physical properties. The use of PLZT in neuro-prosthetic systems, such as retinal implants, has been discussed in a number of publications. Since inorganic lead is a retinotoxic compound that produces retinal degeneration, the long-term stability of PLZT in aqueous biological solutions must be determined. We evaluated the stability and effects of prolonged immersion of a PLZT-coated crystal in a buffered balanced salt solution. Scanning Electron Microscopy and Electron Dispersive Spectroscopy (EDS) using a JEOL JSM 5410 microscope equipped with EDS were utilized to evaluate the samples before and after prolonged immersion. We found that lead and other constituents of PLZT leached into the surrounding aqueous medium. By comparing the unit cell of PLZT with that of CaTiO(3), which has been found to react with aqueous fluids, Lead is in the same site in PLZT as Ca is in CaTiO(3). It is thus reasonable that PLZT will react with aqueous solutions. The results suggest that PLZT must either be coated with a protective layer or is not appropriate for long-term in vivo or in vitro biological applications.

  3. Leading in the Age of Super-Transparency

    DEFF Research Database (Denmark)

    Austin, Robert D.; Upton, David

    2016-01-01

    An essay about super-transparency among organizations is presented. It states that the trend is influenced by the social media and increased flood of data. Also mentioned are best practices for managers to meet expectations which include examining assumptions to keep information contained......, reviewing strategy for dealing with data vulnerability, and reviewing information flows...

  4. Enhanced electrocaloric analysis and energy-storage performance of lanthanum modified lead titanate ceramics for potential solid-state refrigeration applications.

    Science.gov (United States)

    Zhang, Tian-Fu; Huang, Xian-Xiong; Tang, Xin-Gui; Jiang, Yan-Ping; Liu, Qiu-Xiang; Lu, Biao; Lu, Sheng-Guo

    2018-01-10

    The unique properties and great variety of relaxer ferroelectrics make them highly attractive in energy-storage and solid-state refrigeration technologies. In this work, lanthanum modified lead titanate ceramics are prepared and studied. The giant electrocaloric effect in lanthanum modified lead titanate ceramics is revealed for the first time. Large refrigeration efficiency (27.4) and high adiabatic temperature change (1.67 K) are achieved by indirect analysis. Direct measurements of electrocaloric effect show that reversible adiabatic temperature change is also about 1.67 K, which exceeds many electrocaloric effect values in current direct measured electrocaloric studies. Both theoretical calculated and direct measured electrocaloric effects are in good agreements in high temperatures. Temperature and electric field related energy storage properties are also analyzed, maximum energy-storage density and energy-storage efficiency are about 0.31 J/cm 3 and 91.2%, respectively.

  5. Transparency

    DEFF Research Database (Denmark)

    Flyverbom, Mikkel

    2016-01-01

    This article challenges the view of transparency as a matter of providing openness, insight, and clarity by conceptualizing it as a form of visibility management. We tend to think of transparency as a process of ensuring accountability through the timely and public disclosure of information...

  6. Transparency

    DEFF Research Database (Denmark)

    Flyverbom, Mikkel; Albu, Oana Brindusa

    2017-01-01

    Transparency is an increasingly prominent research topic in many scholarly disciplines and offers valuable insights for organizational communication. This entry provides an overview of the historical background and identifies some themes that presently inform the transparency literature. The entry...... then outlines the most important dimensions of the concept of transparency by highlighting two paradigmatic positions underpinning contemporary research in this area: namely, informational approaches that focus on the sharing of information and the perceived quality of that information and social process...... orientations that explore the dynamics of transparency in organizational settings. The entry highlights emergent methodological and conceptual insights concerning transparency as a dynamic and paradoxical social process with performative characteristics – an approach that remains underexplored....

  7. Investigation of the relaxor behavior of sol gel processed lanthanum lead titanium ceramics

    International Nuclear Information System (INIS)

    Limame, K.; Sayouri, S.; Yahyaoui, M.M.; Housni, A.; Jaber, B.

    2016-01-01

    A series of La doped lead titanate samples, with composition Pb_1_−_xLa_xTi_1_−_x_/_4O_3 (PLTx), where x=0.00; 0.02; 0.04; 0.06; 0.07; 0.08; 0.10; 0.12; 0.14; 0.16; 0.18; 0.21 and 0.22 was prepared using the sol–gel process. Addition of La gives rise to the two well-known phenomena: diffuseness and relaxation around the ferro-to-paraelectric transition; the two parameters related to these phenomena, and which give a satisfactory interpretation of them, have been estimated using the Uchino's quadratic law. This diffuse phase transition (DPT) has been investigated with the help of the Landau–Devonshire cluster theory and the model of Cheng et al., to show that polar regions may be generated around the DPT and far from the temperature, T_m, of the maximum of the dielectric permittivity, which have as a direct consequence a non vanishing polarization even if T>T_m.

  8. Investigation of the relaxor behavior of sol gel processed lanthanum lead titanium ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Limame, K. [Centre Régional des Metiers de l' Education et de la Formation (CRMEF) de Fès, Rue deKuwait, BP 49, Fès (Morocco); Laboratoire de Physique Théorique et Appliquée, (LPTA), FSDM, B.P. 1796, Fès-Atlas, Fès (Morocco); Sayouri, S., E-mail: ssayouri@gmail.com [Laboratoire de Physique Théorique et Appliquée, (LPTA), FSDM, B.P. 1796, Fès-Atlas, Fès (Morocco); Yahyaoui, M.M. [Laboratoire de Physique Théorique et Appliquée, (LPTA), FSDM, B.P. 1796, Fès-Atlas, Fès (Morocco); Housni, A. [Laboratoire de Physique Théorique et Appliquée, (LPTA), FSDM, B.P. 1796, Fès-Atlas, Fès (Morocco); Institut Supérieur des Professions Infirmières et Techniques de Santé (ISPITS), Fès (Morocco); Jaber, B. [Centre National pour la Recherche Scientifique et Technique (CNRST), Angle Avenue Allal El Fassi avenue des FAR, Quartie Hay Ryad, BP8027 Nation Unies, Rabat (Morocco)

    2016-08-01

    A series of La doped lead titanate samples, with composition Pb{sub 1−x}La{sub x}Ti{sub 1−x/4}O{sub 3} (PLTx), where x=0.00; 0.02; 0.04; 0.06; 0.07; 0.08; 0.10; 0.12; 0.14; 0.16; 0.18; 0.21 and 0.22 was prepared using the sol–gel process. Addition of La gives rise to the two well-known phenomena: diffuseness and relaxation around the ferro-to-paraelectric transition; the two parameters related to these phenomena, and which give a satisfactory interpretation of them, have been estimated using the Uchino's quadratic law. This diffuse phase transition (DPT) has been investigated with the help of the Landau–Devonshire cluster theory and the model of Cheng et al., to show that polar regions may be generated around the DPT and far from the temperature, T{sub m}, of the maximum of the dielectric permittivity, which have as a direct consequence a non vanishing polarization even if T>T{sub m}.

  9. Transparency

    NARCIS (Netherlands)

    Gupta, A.; Mason, M.

    2015-01-01

    Transparency, as information disclosure, is becoming a widely accepted norm and set of practices in global climate governance. Disclosure of climate-related information is mainly seen as a way to monitor and/or reward various actors’ climate mitigation actions, thereby contributing, at least in

  10. Transparency

    Science.gov (United States)

    LaFee, Scott

    2009-01-01

    Citizens now expect access to information, particularly from public institutions like local school districts. They demand input and accountability. Cultural and technological changes, such as the Internet, make it possible for districts to comply. Yet transparency--the easily seen and understood actions of a school district and the thinking behind…

  11. Electron Emission And Beam Generation Using Ferroelectric Cathodes (electron Beam Generation, Lead Lanthanum Zicronate Titanate, High Power Traveling Wave Tube Amplfier)

    CERN Document Server

    Flechtner, D D

    1999-01-01

    In 1989, researchers at CERN published the discovery of significant electron emission (1– 100 A/cm2) from Lead- Lanthanum-Zirconate-Titanate (PLZT). The publication of these results led to international interest in ferroelectric cathodes studies for use in pulsed power devices. At Cornell University in 1991, experiments with Lead-Zirconate-Titanate (PZT) compositions were begun to study the feasibility of using this ferroelectric material as a cathode in the electron gun section of High Power Traveling Wave Tube Amplifier Experiments. Current-voltage characteristics were documented for diode voltages ranging from 50– 500,000 V with anode cathode gaps of.5– 6 cm. A linear current-voltage relation was found for voltages less than 50 kV. For diode voltages ≥ 200 kV, a typical Child-Langmuir V3/2 dependence was observed...

  12. Study of neutron and gamma shielding by lead borate and bismuth lead borate glasses: transparent radiation shielding

    International Nuclear Information System (INIS)

    Singh, Vishwanath P.; Badiger, N.M.

    2013-01-01

    Radiation shielding for gamma and neutron is the prominent area in nuclear reactor technology, medical application, dosimetry and other industries. Shielding of these types of radiation requires an appropriate concrete with mixture of low-to-high Z elements which is an opaque medium. The transparent radiation shielding in visible light for gamma and neutron is also extremely essential in the nuclear facilities as lead window. Presently various types of lead equivalent glass oxides have been invented which are transparent as well as provide protection from radiation. In our study we have assessment of effectiveness of neutron and gamma radiation shielding of xPbO.(1-x) B 2 O 3 (x=0.15 to 0.60) and xBi 2 O 3 .(0.80-x) PbO.0.20 B 2 O 3 (x=0.10 to 0.70) transparent borate and bismuth glasses by NXCOM program. The neutron effective mass removal cross section, Σ R /ρ (cm 2 /g) of the lead, bismuth and boron oxides are given. We found invariable Σ R /ρ of various combinations of the lead borate glass for x=0.15 to 0.60 and bismuth lead borate glass for x=0.10 to 0.70. It is observed that the effective removal cross-section for fast neutron (cm -1 ) of lead borate reduces significantly whereas roughly constant for bismuth borate. The gamma mass attenuation coefficients (μ/ρ) of the glasses were also compared with possible experimental values and found comparable. High (μ/ρ) for gamma radiation of the bismuth glasses shows that it is better gamma shielding compared with lead containing glass. However lead borate glasses are better neutron shielding as the neutron removal coefficient are higher. Our investigation is very useful for nuclear reactor technology where prompt neutron of energy 17 MeV and gamma photon up to 10 MeV produced. (author)

  13. Electric properties and phase transition behavior in lead lanthanum zirconate stannate titanate ceramics with low zirconate content

    Science.gov (United States)

    Zeng, Tao; Lou, Qi-Wei; Chen, Xue-Feng; Zhang, Hong-Ling; Dong, Xian-Lin; Wang, Gen-Shui

    2015-11-01

    The phase transitions, dielectric properties, and polarization versus electric field (P-E) hysteresis loops of Pb0.97La0.02(Zr0.42Sn0.58-xTix)O3 (0.13≤ x ≤0.18) (PLZST) bulk ceramics were systematically investigated. This study exhibited a sequence of phase transitions by analyzing the change of the P-E hysteresis loops with increasing temperature. The antiferroelectric (AFE) to ferroelectric (FE) phase boundary of PLZST with the Zr content of 0.42 was found to locate at the Ti content between 0.14 and 0.15. This work is aimed to improve the ternary phase diagram of lanthanum-doped PZST with the Zr content of 0.42 and will be a good reference for seeking high energy storage density in the PLZST system with low-Zr content. Project supported by the National Natural Science Foundation of China (Grant Nos. 51202273, 11204304, and 11304334) and the Science and Technology Commission of Shanghai Municipality, China (Grant No. 14DZ2261000).

  14. Adsorption of lithium-lanthanum films on the (100) tungsten face

    International Nuclear Information System (INIS)

    Gupalo, M.S.; Smereka, T.P.; Babkin, G.V.; Palyukh, B.M.

    1982-01-01

    The method of contact potential difference is used to investigate combined adsorption of lithium-lanthanum on the (100) tungsten face. The data on work functions and thermal stability of mixed lithium-lanthanum films are obtained. The presence of lanthanum on the W(100) surface leads to appearance of minimum of work functions unobserved for the Li-W(100) system, minimum work functions and optimum lithium concentration in a mixed film are decreased at initial lanthanum coating increase. The presence of lanthanum on the W(100) face leads to lithium adsorption heat decrease

  15. Electrochemical reduction of lanthanum trichloride in a molten equimolar mixture of sodium and potassium chlorides

    Energy Technology Data Exchange (ETDEWEB)

    Glagolevskaya, A.L.; Kuznetsov, S.A.; Polyakov, E.G.; Stangrit, P.T.

    1987-09-20

    The authors used linear voltamperometry for the investigation of the mechanism for the cathodic reduction of lanthanum. The mechanism for the cathodic reduction of lanthanum chloride in molten equimolar NaCl-KCl may be seen as consisting of a slow irreversible electrode reaction with a subsequent rapid irreversible chemical reaction. Lanthanum ions in a lower oxidation state were not found upon the prolonged maintenance of metallic lanthanum in molten NaCl-KCl-LaCl/sub 3/. Only an increase in the concentration of lanthanum(III) chloride in the melt was noted. The appearance of oxygen anions in the melt does not lead to a change in the mechanism of the cathodic reduction of lanthanum chloride but reduces the concentration of this chloride due to the formation of lanthanum oxochloride which is insoluble in the melt.

  16. Encephalopathy caused by lanthanum carbonate.

    Science.gov (United States)

    Fraile, Pilar; Cacharro, Luis Maria; Garcia-Cosmes, Pedro; Rosado, Consolacion; Tabernero, Jose Matias

    2011-06-01

    Lanthanum carbonate is a nonaluminum, noncalcium phosphate-binding agent, which is widely used in patients with end-stage chronic kidney disease. Until now, no significant side-effects have been described for the clinical use of lanthanum carbonate, and there are no available clinical data regarding its tissue stores. Here we report the case of a 59-year-old patient who was admitted with confusional syndrome. The patient received 3750 mg of lanthanum carbonate daily. Examinations were carried out, and the etiology of the encephalopathy of the patient could not be singled out. The lanthanum carbonate levels in serum and cerebrospinal fluid were high, and the syndrome eased after the drug was removed. The results of our study confirm that, in our case, the lanthanum carbonate did cross the blood-brain barrier (BBB). Although lanthanum carbonate seems a safe drug with minimal absorption, this work reveals the problem derived from the increase of serum levels of lanthanum carbonate, and the possibility that it may cross the BBB. Further research is required on the possible pathologies that increase serum levels of lanthanum carbonate, as well as the risks and side-effects derived from its absorption.

  17. Transparency International

    NARCIS (Netherlands)

    Hulten, van M. (Michel)

    2009-01-01

    Established in 1993, Transparency International (TI) defines itself as “the global civil society organization leading the fight against corruption, that brings people together in a powerful worldwide coalition to end the devastating impact of corruption on men, women and children around the

  18. Lanthanum chromite colloidal processing

    International Nuclear Information System (INIS)

    Setz, Luiz Fernando Grespan

    2009-01-01

    Lanthanum chromite (LaCrO 3 ) is currently the most studied material for applications such as solid oxide fuel cell inter connector (HTSOFC). The complexity of microstructures and geometries of HTSOFC devices, require a precise control of processing parameters to get the desired combination of properties and this, the use of techniques involving concentrated ceramic slips conformation are appropriate, therefore, is well controlled, assist in obtaining homogeneous parts, reproductive and complex geometries. Thus, studies involving the surface chemistry, the stability conditions and slips flow behaviour in the forming conditions, provide important elements for processes control in the inter connectors manufacture, where more applied settings have slots and channels for the gases passage. Thus, surface chemistry, stability and rheological behaviour of strontium and cobalt doped LaCrO 3 (La) 0.80 Sr 0. 2 0 Cr 0.92 Co 0.08 O 3 ) slips prepared with ethanol and water, were studied. The doped lanthanum chromite was produced by combustion synthesis in the IPEN/SP labs. The influence of parameters: pH (water), dispersant concentration, homogenization times and conditions, solid concentration, different ratios binder:plasticizer in the stability and the flow behavior of ceramic suspensions prepared were evaluated. The La) 0.80 Sr 0. 2 0 Cr 0.92 Co 0.08 O 3 products obtained by casting aqueous slips in a plaster mould, using alkaline pH and anionic polyelectrolyte and tapes obtained by using ethanol as a dispersant medium, after sintering at 1600 degree C/4 hours presented theoretical density > 94%, suitable for use as HTSOFC inter connector. (author)

  19. Cytocompatibility of a free machining titanium alloy containing lanthanum.

    Science.gov (United States)

    Feyerabend, Frank; Siemers, Carsten; Willumeit, Regine; Rösler, Joachim

    2009-09-01

    Titanium alloys like Ti6Al4V are widely used in medical engineering. However, the mechanical and chemical properties of titanium alloys lead to poor machinability, resulting in high production costs of medical products. To improve the machinability of Ti6Al4V, 0.9% of the rare earth element lanthanum (La) was added. The microstructure, the mechanical, and the corrosion properties were determined. Lanthanum containing alloys exhibited discrete particles of cubic lanthanum. The mechanical properties and corrosion resistance were slightly decreased but are still sufficient for many applications in the field of medical engineering. In vitro experiments with mouse macrophages (RAW 264.7) and human bone-derived cells (MG-63, HBDC) were performed and revealed that macrophages showed a dose response below and above a LaCl3 concentration of 200 microM, while MG-63 and HBDC tolerated three times higher concentrations without reduction of viability. The viability of cells cultured on disks of the materials showed no differences between the reference and the lanthanum containing alloy. We therefore propose that lanthanum containing alloy appears to be a good alternative for biomedical applications, where machining of parts is necessary.

  20. A Density Functional Theory Study of Doped Tin Monoxide as a Transparent p-type Semiconductor

    KAUST Repository

    Bianchi Granato, Danilo

    2012-01-01

    that yttrium and lanthanum improves the hole mobility. Present results are in good agreement with available experimental works and help to improve the understanding on how to engineer transparent p-type materials with higher hole mobilities.

  1. Highly concentrated collagen solutions leading to transparent scaffolds of controlled three-dimensional organizations for corneal epithelial cell colonization.

    Science.gov (United States)

    Tidu, Aurélien; Ghoubay-Benallaoua, Djida; Teulon, Claire; Asnacios, Sophie; Grieve, Kate; Portier, François; Schanne-Klein, Marie-Claire; Borderie, Vincent; Mosser, Gervaise

    2018-05-29

    This study aimed at controlling both the organization and the transparency of dense collagen scaffolds making use of the lyotropic mesogen properties of collagen. Cholesteric or plywood-like liquid crystal phases were achieved using mixtures of acetic and hydrochloric acids as solvents. The critical pH at which the switch between the two phases occurred was around pH = 3. The use of the two acids led to fibrillated collagen I scaffolds, whose visual aspect ranged from opaque to transparent. Rheological investigations showed that viscoelastic properties of the plywood-like solutions were optimized for molding due to faster recovery. They also confirmed the correlation between the elastic modulus and the diameter of collagen fibrils obtained after fibrillogenesis under ammonia vapor. Human corneal epithelial cells, grown from donor limbal explants, were cultured both on transparent plywood-like matrices and on human amniotic membranes for 14 days. The development of corneal epithelium and the preservation of epithelial stem cells were checked by optical microscopy, colony formation assay, immuno-fluorescence and quantitative polymerase chain reaction. A higher level of amplification of limbal stem cells was obtained with collagen matrices compared with amniotic membranes, showing the high biocompatibility of our scaffolds. We therefore suggest that collagen solutions presenting both plywood-like organization and transparency might be of interest for biomedical applications in ophthalmology.

  2. Color transparency

    International Nuclear Information System (INIS)

    Miller, G.A.

    1993-01-01

    Imagine shooting a beam of protons of high momentum P through an atomic nucleus. Usually the nuclear interactions prevent the particles from emerging with momentum ∼P. Further, the angular distribution of elastically scattered protons is close to the optical diffraction pattern produced by a black disk. Thus the nucleus acts as a black disk and is not transparent. However, certain high momentum transfer reactions in which a proton is knocked out of the nucleus may be completely different. Suppose that the high momentum transfer process leads to the formation of a small-size color singlet wavepacket that is ejected from the nucleus. The effects of gluons emitted by color singlet systems of closely separated quarks and gluons tend to cancel. Thus the wavepacket-nuclear interactions are suppressed, the nucleus becomes transparant and one says that color transparency CT occurs. The observation of CT also requires that the wavepacket not expand very much while it moves through the nucleus. Simple quantum mechanical formulations can assess this expansion. The creation of a small-sized wavepacket is expected in asymptotic perturbative effects. The author reviews the few experimental attempts to observe color transparency in nuclear (e,e'p) and (p,pp) reactions and interpret the data and their implications

  3. Cerium-activated lanthanum beryllate as a gamma detector material

    International Nuclear Information System (INIS)

    Czirr, J.B.; Berrondo, M.

    1994-01-01

    The authors have tested a single crystal of Ce-activated lanthanum beryllate BEL(Ce) as a potential gamma detector material. The density (6.1 g.cm -3 ) and decay time (50 ns) are competitive with other recently developed materials. The scintillation efficiency is 57 to 95% that of BGO. For an excitation wavelength of 340 nm, the emission spectra is a broad peak centered at 450 mn. The H 2 annealed sample is transparent for wavelengths greater than 400 mn. They are continuing a program to improve the scintillation efficiency by varying the crystal growth conditions

  4. Point-of-need simultaneous electrochemical detection of lead and cadmium using low-cost stencil-printed transparency electrodes.

    Science.gov (United States)

    Martín-Yerga, Daniel; Álvarez-Martos, Isabel; Blanco-López, M Carmen; Henry, Charles S; Fernández-Abedul, M Teresa

    2017-08-15

    In this work, we report a simple and yet efficient stencil-printed electrochemical platform that can be integrated into the caps of sample containers and thus, allows in-field quantification of Cd(II) and Pb(II) in river water samples. The device exploits the low-cost features of carbon (as electrode material) and paper/polyester transparency sheets (as substrate). Electrochemical analysis of the working electrodes prepared on different substrates (polyester transparency sheets, chromatographic, tracing and office papers) with hexaammineruthenium(III) showed that their electroactive area and electron transfer kinetics are highly affected by the porosity of the material. Electrodes prepared on transparency substrates showed the best electroanalytical performance for the simultaneous determination of Cd(II) and Pb(II) by square-wave anodic stripping voltammetry. Interestingly, the temperature and time at which the carbon ink was cured had significant effect on the electrochemical response, especially the capacitive current. The amount of Cd and Pb on the electrode surface can be increased about 20% by in situ electrodeposition of bismuth. The electrochemical platform showed a linear range comprised between 1 and 200 μg/L for both metals, sensitivity of analysis of 0.22 and 0.087 μA/ppb and limits of detection of 0.2 and 0.3 μg/L for Cd(II) and Pb(II), respectively. The analysis of river water samples was done directly in the container where the sample was collected, which simplifies the procedure and approaches field analysis. The developed point-of-need detection system allowed simultaneous determination of Cd(II) and Pb(II) in those samples using the standard addition method with precise and accurate results. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Complexometric determination of lanthanum and calcium in lanthanum chromite

    International Nuclear Information System (INIS)

    Novoselova, I.M.

    1989-01-01

    Methods of complexometric determination of lanthanum and calcium in lanthanum chromite, based on sequential titration of La and Ca by EDTA solution, where as an indicator eriochrome brack T with NaCl mixture in the ratio of 1:100 is used, are determined. Cr (3) effect was removed by its oxidation up to Cr (6) with perchloric acid; at first La was determined in presence of urotropine buffer, then Ca at pH 9.5-10 in presence of ammonia buffer. For reaction acceleration method of back titration of EDTA excess by zinc salt solution was used. Standard deviation in La and Ca determination is not over 0.2 and 0.1 % respectively

  6. Nanostructured Lanthanum Halides and CeBr3 for Nuclear Radiation and Detection

    International Nuclear Information System (INIS)

    Guss, Paul; Mukhopadhyay, Sanjoy; Guise, Ron; Yuan, Ding

    2010-01-01

    Scintillator materials are used to detect, and in some cases identify, gamma rays. Higher performance scintillators are expensive, hard to manufacture, fragile, and sometimes require liquid nitrogen or cooling engines. But whereas lower-quality scintillators are cheap, easy to manufacture, and more rugged, their performance is lower. At issue: can the desirable qualities of high-and low-performance scintillators be combined to achieve better performance at lower cost? Preliminary experiments show that a LaF 3 :Ce oleic acid-based nanocomposite exhibits a photopeak when exposed to 137 Cs source gamma-radiation. The chemical synthesis of the cerium-doped lanthanum halide nanoparticles are scalable and large quantities of material can be produced at a time, unlike typical crystal growth processes such as the Bridgeman process. Using a polymer composite (Figure 1), produced by LANL, initial measurements of the unloaded and 8% LaF 3 :Ce-loaded sample have been made using 137 Cs sources. Figure 2 shows an energy spectrum acquired for CeF 3 . The lighter plot is the measured polymer-only spectrum and the black plot is the spectrum from the nanocomposite scintillator. As the development of this material continues, the energy resolution is expected to improve and the photopeak-to-Compton ratio will become greater at higher loadings. These measurements show the expected Compton edge in the polymer-only sample, and the Compton edge and photo-peak expected in the nanophosphor composites that LANL has produced. Using a porous VYCORR with CdSe/ZnS core shell quantum dots, Letant has demonstrated that he has obtained signatures of the 241Am photopeak with energy resolution as good at NaI (Figure 3). We begin with the fact that CeBr 3 crystals do not have a self-activity component as strong as the lanthanum halides. The radioactive 0.090% 138 La component of lanthanum leads to significant self-activity, which will be a problem for very large detector volumes. Yet a significant

  7. DISSOLUTION OF LANTHANUM FLUORIDE PRECIPITATES

    Science.gov (United States)

    Fries, B.A.

    1959-11-10

    A plutonium separatory ore concentration procedure involving the use of a fluoride type of carrier is presented. An improvement is given in the derivation step in the process for plutonium recovery by carrier precipitation of plutonium values from solution with a lanthanum fluoride carrier precipitate and subsequent derivation from the resulting plutonium bearing carrier precipitate of an aqueous acidic plutonium-containing solution. The carrier precipitate is contacted with a concentrated aqueous solution of potassium carbonate to effect dissolution therein of at least a part of the precipitate, including the plutonium values. Any remaining precipitate is separated from the resulting solution and dissolves in an aqueous solution containing at least 20% by weight of potassium carbonate. The reacting solutions are combined, and an alkali metal hydroxide added to a concentration of at least 2N to precipitate lanthanum hydroxide concomitantly carrying plutonium values.

  8. Transparency in Organizing

    DEFF Research Database (Denmark)

    Albu, Oana Brindusa

    This dissertation provides a critical analysis of transparency in the context of organizing. The empirical material is based on qualitative studies of international cooperative organizations. The dissertation seeks to contribute to transparency and organizing scholarship by adopting a communication...... centred approach to explore the implications of pursuing ideals of transparency in organizational relationships. The dissertation is comprised of four papers each contributing to extant debates in organizational studies and transparency literature. The findings indicate that transparency, in contrast...... to being a solution for efficiency and democratic organizing, is a communicatively contested process which may lead to unintended consequences. The dissertation shows that transparency is performative: it can impact authority by de/legitimating action, shape the processes of organizational identity co...

  9. Lanthanum Containing Polymer's Modification to PP

    Institute of Scientific and Technical Information of China (English)

    Dai Shaojun; Zhang Ming

    2004-01-01

    Polypropylene (PP)'s low impact strength limits its usages. Adding some a rare earth polymer can enhance PP's tensile strength and impact strength. Acrylic lanthanum was prepared by the reaction between lanthanum oxide and acrylic acid. The IR spectrum prove that and optimum reacting conditions are that the bulk ratio of La(AA) 3 and MMA is not less than one and temperature is about 80 ℃. Lanthanum containing Polymer were added into PP. When percent of addition only was 3%, strength were enhanced 10% , and impact strength 40%. SEM shows the compatibility of rare earth polymer and PP; lanthanum containing polymer can form physical crosslinking between PP's molecules, then every particle's surface connect with several PP molecules and the PP mechanical property were enhanced.

  10. Signal amplification of dopamine using lanthanum hexacyanoferrate ...

    Indian Academy of Sciences (India)

    rare earth metal hexacyanoferrates, for e.g., lanthanum ... to facilitate the electrochemical reactions of biological molecules.9,10 In general ... bic acid and potassium hexacyanoferrate (Merck) were ... were prepared using doubly distilled water.

  11. Properties of gallium lanthanum sulphide glass

    OpenAIRE

    Bastock, P.; Craig, C.; Khan, K.; Weatherby, E.; Yao, J.; Hewak, D.W.

    2015-01-01

    A series of gallium lanthanum sulphide (GLS) glasses has been studied in order to ascertain properties across the entire glass forming region. This is the first comprehensive study of GLS glass over a wide compositional range.

  12. Organizational Transparency

    DEFF Research Database (Denmark)

    Albu, Oana Brindusa; Flyverbom, Mikkel

    2018-01-01

    with the sharing of information and the perceived quality of the information shared. This narrow focus on information and quality, however, overlooks the dynamics of organizational transparency. To provide a more structured conceptualization of organizational transparency, this article unpacks the assumptions......Transparency is an increasingly prominent area of research that offers valuable insights for organizational studies. However, conceptualizations of transparency are rarely subject to critical scrutiny and thus their relevance remains unclear. In most accounts, transparency is associated...... that shape the extant literature, with a focus on three dimensions: conceptualizations, conditions, and consequences. The contribution of the study is twofold: (a) On a conceptual level, we provide a framework that articulates two paradigmatic positions underpinning discussions of transparency, verifiability...

  13. TRANSPARENT CONCRETE

    OpenAIRE

    Sandeep Sharma*, Dr. O.P. Reddy

    2017-01-01

    Transparent concrete is the new type of concrete introduced in todays world which carries special property of light transmitting due to presence of light Optical fibres. Which is also known as translucent concrete or light transmitting concrete, it is achieved by replacing coarse aggregates with transparent alternate materials (Optical fibres). The binding material in transparent concrete may be able to transmit light by using clear resins the concrete mix. The concrete used in industry in pr...

  14. Color transparency

    International Nuclear Information System (INIS)

    Pire, B.; Ralston, J.P.

    1991-01-01

    This paper reviews the physics of color transparency and the unexpected energy dependence of recent measurements of high-energy fixed-angle elastic scattering in nuclear targets. The authors point out advantages of using transparency as a tool, introducing two concepts - spin and flavor flow filtering - that may be studied with nuclear targets. The special case of electroproduction is also considered

  15. Corrosion and electrochemical properties of lanthanum

    International Nuclear Information System (INIS)

    Tomashov, N.D.; Matveeva, T.V.

    The kinetics of the corrosion rate of lanthanum at 25 0 in air of different relative humidities, distilled water, sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, hydrofluoric acid, potassium hydroxide of different concentrations and at 100 0 C in distilled water and potassium hydroxide have been studied. In air at 22--100% relative humidity, the corrosion rate of lanthanum increases with time and with increasing humidity. In distilled water and in potassium hydroxide solutions, the corrosion rate of lanthanum increases with time and decreasees when the concentration of alkali exceeds 20%. With increasing concentration of the acids, the corrosion rate of lanthanum increases in hydrochloric acid and nitric acid and passes through a maximum in sulfuric acid (20%) and phosphoric acid (60%). The values of the corrosion rates of lanthanum in 40% nitric acid, 35% hydrochloric acid, 20% sulfuric acid, 60% phosphoric acid, and 40% hydrofluoric acid are 8 x 10 5 ; 4.4 x 10 4 ; 1.3 x 10 3 ; 9 g/m 2 h respectively

  16. Fuel cells with doped lanthanum gallate electrolyte

    Science.gov (United States)

    Feng, Man; Goodenough, John B.; Huang, Keqin; Milliken, Christopher

    Single cells with doped lanthanum gallate electrolyte material were constructed and tested from 600 to 800°C. Both ceria and the electrolyte material were mixed with NiO powder respectively to form composite anodes. Doped lanthanum cobaltite was used exclusively as the cathode material. While high power density from the solid oxide fuel cells at 800°C was achieved. our results clearly indicate that anode overpotential is the dominant factor in the power loss of the cells. Better anode materials and anode processing methods need to be found to fully utilize the high ionic conductivity of the doped lanthanum galiate and achieve higher power density at 800°C from solid oxide fuel cells.

  17. Fuel cells with doped lanthanum gallate electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Feng Man [Texas Univ., Austin, TX (United States). Center for Materials Science and Engineering; Goodenough, J.B. [Texas Univ., Austin, TX (United States). Center for Materials Science and Engineering; Huang Keqin [Texas Univ., Austin, TX (United States). Center for Materials Science and Engineering; Milliken, C. [Cerematec, Inc., Salt Lake City, UT (United States)

    1996-11-01

    Single cells with doped lanthanum gallate electrolyte material were constructed and tested from 600 to 800 C. Both ceria and the electrolyte material were mixed with NiO powder respectively to form composite anodes. Doped lanthanum cobaltite was used exclusively as the cathode material. While high power density from the solid oxide fuel cells at 800 C was achieved, our results clearly indicate that anode overpotential is the dominant factor in the power loss of the cells. Better anode materials and anode processing methods need to be found to fully utilize the high ionic conductivity of the doped lanthanum gallate and achieve higher power density at 800 C from solid oxide fuel cells. (orig.)

  18. Process for obtaining cobalt and lanthanum nickelate

    International Nuclear Information System (INIS)

    Tapcov, V.; Samusi, N.; Gulea, A.; Horosun, I.; Stasiuc, V.; Petrenco, P.

    1999-01-01

    The invention relates to the process for obtaining polycrystalline ceramics of cobalt and lanthanum nickelate with the perovskite structure from coordinative hetero metallic compounds. The obtained products can be utilized in the industry in the capacity of catalysts. Summary of the invention consists in obtaining polycrystalline ceramics LaCoO 3 and LaNiO 3 with the perovskite structure by pyrolysis of the parent compounds, namely, the coordinative hetero metallic compounds of the lanthanum cobalt or lanthanum nickel. The pyrolysis of the parent compound runs during one hour at 800 C. The technical result of the invention consists in lowering the temperature of the parent compound pyrolysis containing the precise ratio of metals necessary for ceramics obtaining

  19. What color transparency measures

    International Nuclear Information System (INIS)

    Jain, P.; Ralston, J.P.

    1992-01-01

    Color transparency is commonly accepted to be a prediction of perturbative QCD. However it is more a phenomenon probing the interface between the perturbative and nonperturbative regimes, leading to some intricacy in its theoretical description. In this paper we study the consequences of the impulse approximation to the theory in various quantum mechanical bases. We show that the fully interacting hadronic basis, which consists of eigenstates of the exact Hamiltonian in the presence of the nucleus, provides a natural basis to study color transparency. In this basis we can relate the quark wave function at a small transverse separation distance b 2 2 directly to transparency ratios measured in experiment. With the formalism, experiment can be used to map out the quark wave function in this region. We exhibit several loopholes in existing arguments predicting a rise in transparency ratios with energy, and suggest alternatives. Among the results, we argue that the theoretical prediction of a rising transparency ratio with energy may be on better footing for heavy-quark bound states than for relativistic light-quark systems. We also point out that transparency ratios can be constant with energy and not at variance with perturbative QCD

  20. A Density Functional Theory Study of Doped Tin Monoxide as a Transparent p-type Semiconductor

    KAUST Repository

    Bianchi Granato, Danilo

    2012-05-01

    In the pursuit of enhancing the electronic properties of transparent p-type semiconductors, this work uses density functional theory to study the effects of doping tin monoxide with nitrogen, antimony, yttrium and lanthanum. An overview of the theoretical concepts and a detailed description of the methods employed are given, including a discussion about the correction scheme for charged defects proposed by Freysoldt and others [Freysoldt 2009]. Analysis of the formation energies of the defects points out that nitrogen substitutes an oxygen atom and does not provide charge carriers. On the other hand, antimony, yttrium, and lanthanum substitute a tin atom and donate n-type carriers. Study of the band structure and density of states indicates that yttrium and lanthanum improves the hole mobility. Present results are in good agreement with available experimental works and help to improve the understanding on how to engineer transparent p-type materials with higher hole mobilities.

  1. Broadband plasmon induced transparency in terahertz metamaterials

    KAUST Repository

    Zhu, Zhihua; Yang, Xu; Gu, Jianqiang; Jiang, Jun; Yue, Weisheng; Tian, Zhen; Tonouchi, Masayoshi; Han, Jiaguang; Zhang, Weili

    2013-01-01

    Plasmon induced transparency (PIT) could be realized in metamaterials via interference between different resonance modes. Within the sharp transparency window, the high dispersion of the medium may lead to remarkable slow light phenomena

  2. An epitaxial transparent conducting perovskite oxide: double-doped SrTiO3

    NARCIS (Netherlands)

    Ravichandran, Jayakanth; Siemons, W.; Heijmerikx, Herman; Huijben, Mark; Majumdar, Arun; Ramesh, Ramamoorthy

    2010-01-01

    Epitaxial thin films of strontium titanate doped with different concentrations of lanthanum and oxygen vacancies were grown on LSAT substrates by pulsed laser deposition technique. Films grown with 5−15% La doping and a critical growth pressure of 1−10 mTorr showed high transparency (>70−95%) in the

  3. Trimethylphosphide isomerization in lanthanum ions presence

    International Nuclear Information System (INIS)

    Zacharias, M.A.; Massabni, A.M.G.

    1984-01-01

    The integration between the trimethilphosphide and the lanthanum ions carry to the formation of solid complexes in a relation of 6:1 where the ligand is the phosphonate what is resultant of the isomerization of trimetylphosphite. By the RMN -1 H and infra-red spectra the products were characterized. (L.M.J.) [pt

  4. Public Transparency

    OpenAIRE

    UNCTAD; World Bank

    2018-01-01

    This note provides guidance on the type of information about agricultural investments that investors and governments can make publicly available. Transparency about certain aspects of investments can improve relations between investors and communities, enable external stakeholders to hold investors to commitments, and improve investors’ public image. Although some information should be kep...

  5. Color transparency

    International Nuclear Information System (INIS)

    Jennings, B.K.; Miller, G.A.

    1993-01-01

    The anomously large transmission of nucleons through a nucleus following a hard collision is explored. This effect, known as color transparency, is believed to be a prediction of QCD. The necessary conditions for its occurrence and the effects that must be included a realistic calculation are discussed

  6. High Temperature Transparent Furnace Development

    Science.gov (United States)

    Bates, Stephen C.

    1997-01-01

    This report describes the use of novel techniques for heat containment that could be used to build a high temperature transparent furnace. The primary objective of the work was to experimentally demonstrate transparent furnace operation at 1200 C. Secondary objectives were to understand furnace operation and furnace component specification to enable the design and construction of a low power prototype furnace for delivery to NASA in a follow-up project. The basic approach of the research was to couple high temperature component design with simple concept demonstration experiments that modify a commercially available transparent furnace rated at lower temperature. A detailed energy balance of the operating transparent furnace was performed, calculating heat losses through the furnace components as a result of conduction, radiation, and convection. The transparent furnace shells and furnace components were redesigned to permit furnace operation at at least 1200 C. Techniques were developed that are expected to lead to significantly improved heat containment compared with current transparent furnaces. The design of a thermal profile in a multizone high temperature transparent furnace design was also addressed. Experiments were performed to verify the energy balance analysis, to demonstrate some of the major furnace improvement techniques developed, and to demonstrate the overall feasibility of a high temperature transparent furnace. The important objective of the research was achieved: to demonstrate the feasibility of operating a transparent furnace at 1200 C.

  7. Does transparent government agencies strengthen trust?

    NARCIS (Netherlands)

    Grimmelikhuijsen, S.G.

    2009-01-01

    Trust in government has been shown to be volatile in recent years and Internet transparency is seen as a solution to strengthen trust. However, critics argue that transparency will only lead to less trust, and sceptics say that it has no effect at all. This debate on transparency is lacking

  8. Effect of various lanthanum sol-gel coatings on the 330Cb (Fe-35Ni-18Cr-1Nb-2Si) oxidation at 900 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Buscail, H., E-mail: buscail@iut.u-clermont1.fr [Clermont Universite- LVEEM, 8 rue J.B. Fabre, BP 219, 43006 Le Puy en Velay (France); Issartel, C.; Riffard, F.; Rolland, R.; Perrier, S. [Clermont Universite- LVEEM, 8 rue J.B. Fabre, BP 219, 43006 Le Puy en Velay (France); Fleurentin, A. [CETIM, 52 av Felix Louat, BP 80067, 60304 Senlis (France); Josse, C. [L' ICB UMR5209 CNRS, BP 47870, 21078 Dijon (France)

    2011-11-01

    The influence of a lanthanum sol-gel coating on the oxide scale adherence has been studied during the 330Cb (Fe-35Ni-18Cr-1Nb-2Si) oxidation at 900 deg. C, in air. The alloy oxidation is performed in order to generate a protective chromia scale acting as a good barrier against carburization. Argon annealing of lanthanum sol-gel coatings have been performed at various temperatures in order to find the best conditions to insure the scale adherence. Kinetic results show that lanthanum sol-gel coatings lead to a lower oxidation rate compared to blank specimens. Thermal cycling tests on lanthanum the sol-gel coated specimen show that the oxide scale formed at 900 deg. C, in air, is adherent.

  9. Electrochemical properties of lanthanum nitride with calcium nitride additions

    International Nuclear Information System (INIS)

    Lesunova, R.P.; Fishman, L.S.

    1986-01-01

    This paper reports on the electrochemical properties of lanthanum nitride with calcium nitride added. The lanthanum nitride was obtained by nitriding metallic lanthanum at 870 K in an ammonia stream. The product contained Cl, Pr, Nd, Sm, Fe, Ca, Cu, Mo, Mg, Al, Si, and Be. The calcium nitride was obtained by nitriding metallic calcium in a nitrogen stream. The conductivity on the LaN/C 3 N 2 system components are shown as a function of temperature. A table shows the solid solutions to be virtually electronic conductors and the lanthanum nitride a mixed conductor

  10. Properties of lanthanum hexaboride a compilation

    CERN Document Server

    Fisher, D J

    2013-01-01

    Lanthanum hexaboride is useful because it possesses a high melting point (2210C), a low work function, one of the highest known electron emissivities, and is stable in vacuum. This volume summarises the extant data on the properties of this material, including the: bulk modulus, conductivity, crystal structure, Debye temperature, defect structure, elastic constants, electronic structure, emissivity, Fermi surface, hardness, heat capacity, magnetoresistance, reflectivity, resistivity, specific heat, surface structure, thermal conductivity, thermoelectric power, toughness and work function. The

  11. Preparation and characterization of perovskite structure lanthanum gallate and lanthanum aluminate based oxides

    OpenAIRE

    Li, Shuai

    2009-01-01

    The present work was initiated to study the synthesis and properties of lanthanum gallate based oxides as intermediate temperature electrolyte for solid oxide fuel cells. The wet chemical method, polymer complexing route, was used to prepare the precursor powders. To further investigate the polymer complexing method, it was also applied to the preparation of lanthanum aluminate based oxides.   Single perovskite phase La0.8Sr0.2Ga0.83Mg0.17O2.815 can be prepared by the polymer complexing meth...

  12. Effects of polyaluminum chloride and lanthanum-modified bentonite on the growth rates of three Cylindrospermopsis raciborskii strains

    NARCIS (Netherlands)

    Araújo, Fabiana; van Oosterhout, Frank; Becker, Vanessa; Attayde, José Luiz; Lürling, Miquel

    2018-01-01

    In tropical and subtropical lakes, eutrophication often leads to nuisance blooms of Cylindrospermopsis raciborskii. In laboratory experiments, we tested the combined effects of flocculant polyaluminum chloride (PAC) and lanthanum-modified bentonite (LMB) on the sinking and growth rates of three C.

  13. Lanthanum trilactate: Vibrational spectroscopic study - infrared/Raman spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Švecová, M.; Novák, Vít; Bartůněk, V.; Člupek, M.

    2016-01-01

    Roč. 87, Nov (2016), s. 123-128 ISSN 0924-2031 Institutional support: RVO:61388963 Keywords : lanthanum trilactate * tris(2-hydroxypropanoato-O1,O2) * lanthanum tris[2-(hydroxy-kappa O)propanoato-kappa O] * Raman spectra * infrared spectra * DFT Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.740, year: 2016

  14. Passive Collecting of Solar Radiation Energy using Transparent Thermal Insulators, Energetic Efficiency of Transparent Thermal Insulators

    Directory of Open Access Journals (Sweden)

    Smajo Sulejmanovic

    2014-11-01

    Full Text Available This paper explains passive collection of solar radiation energy using transparent thermal insulators. Transparent thermal insulators are transparent for sunlight, at the same time those are very good thermal insulators. Transparent thermal insulators can be placed instead of standard conventional thermal insulators and additionally transparent insulators can capture solar radiation, transform it into heat and save heat just as standard insulators. Using transparent insulators would lead to reduce in usage of fossil fuels and would help protection of an environment and reduce effects of global warming, etc.

  15. Bio-accumulation of lanthanum from lanthanum modified bentonite treatments in lake restoration

    NARCIS (Netherlands)

    Waajen, G.; Van Oosterhout, F.; Lürling, M.

    2017-01-01

    Abstract Lanthanum (La) modified bentonite (LMB) is one of the available mitigating agents used for the reduction of the phosphorus (P) recycling in eutrophic lakes. The potential toxicity of the La from LMB to aquatic organisms is a matter of concern. In this study the accumulation of La was

  16. Modification of TiO2 nanoparticles through lanthanum doping and PEG templating

    Directory of Open Access Journals (Sweden)

    Marija Milanovic

    2014-12-01

    Full Text Available Pure and lanthanum doped titania nanopowders were synthesized through a room temperature sol-gel method using a template of polyethylene glycol (PEG. The progress of the synthesis in terms of phase formation and size of nanoparticles was monitored by X-ray diffraction, FTIR spectroscopy and SEM analysis. After calcination at 450 °C in air, the results have shown the presence of small particles crystallized predominantly in the form of anatase phase, with significant agglomeration. Nitrogen adsorption-desorption measurements confirmed that all prepared powders are mesoporous with an average pore diameter in range 3.1–3.8 nm. The addition of lanthanum ions leads to the nanopowders with the highest specific surface (BET area (203 m2/g. The obtained powders were compared to TiO2 prepared without a template.

  17. Limits of transparency of transparent conducting oxides

    Science.gov (United States)

    Peelaers, Hartwin

    A fundamental understanding of the factors that limit transparency in transparent conducting oxides (TCOs) is essential for further progress in materials and applications. These materials have a sufficiently large band gap, so that direct optical transitions do not lead to absorption of light within the visible spectrum. Since the presence of free carriers is essential for conductivity and thus for device applications, this introduces the possibility of additional absorption processes. In particular, indirect processes are possible, and these will constitute a fundamental limit of the material. The Drude theory is widely used to describe free-carrier absorption, but it is phenomenological in nature and tends to work poorly at shorter wavelengths, where band-structure effects are important. We will present calculations of phonon- and defect-assisted free-carrier absorption in a TCO completely from first principles. We will focus in detail on SnO2, but the methodology is general and we will also compare the results obtained for other TCO materials such as In2O3. These calculations provide not just quantitative results but also deeper insights in the mechanisms that govern absorption processes, which is essential for engineering improved materials to be used in more efficient devices. This work was performed in collaboration with E. Kioupakis and C.G. Van de Walle and was supported by ARO and NSF.

  18. Transparent Ferroelectric Capacitors on Glass

    Directory of Open Access Journals (Sweden)

    Daniele Sette

    2017-10-01

    Full Text Available We deposited transparent ferroelectric lead zirconate titanate thin films on fused silica and contacted them via Al-doped zinc oxide (AZO transparent electrodes with an interdigitated electrode (IDE design. These layers, together with a TiO2 buffer layer on the fused silica substrate, are highly transparent (>60% in the visible optical range. Fully crystallized Pb(Zr0.52Ti0.48O3 (PZT films are dielectrically functional and exhibit a typical ferroelectric polarization loop with a remanent polarization of 15 μC/cm2. The permittivity value of 650, obtained with IDE AZO electrodes is equivalent to the one measured with Pt electrodes patterned with the same design, which proves the high quality of the developed transparent structures.

  19. Aerospace Transparency Research Compendium

    National Research Council Canada - National Science Library

    Pinkus, Alan

    2003-01-01

    ... (ARRL), located at Wright-Patterson AFB OH, has advanced aerospace transparency technology through the investigative research of numerous optical and visual parameters inherent in aerospace transparencies...

  20. Effects of Dredging and Lanthanum-Modified Clay on Water Quality Variables in an Enclosure Study in a Hypertrophic Pond

    Directory of Open Access Journals (Sweden)

    Miquel Lürling Guido Waajen

    2017-05-01

    Full Text Available An enclosure experiment was conducted between July and September 2009 to compare the effectiveness of a phosphate fixative, the lanthanum-modified bentonite clay Phoslock® (LMB, dredging, and their combination in controlling eutrophication in a hypertrophic urban pond in Heesch, The Netherlands. In total, 25 water quality variables were monitored. Multivariate analysis revealed that the combination LMB-treated and dredged enclosures deviated most from the pond (reference and the controls, and showed the strongest eutrophication reduction. Overall, dredging significantly increased transparency, lowered turbidity, and improved the oxygen conditions in the enclosures compared to non-dredged ones. Nonetheless, one dredged enclosure deviated dramatically from the others, which might reflect methodological issues with dredging. The LMB treatment appeared to be less effective at mitigating eutrophication than dredging, and phosphate concentrations even increased during the experiment in the LMB-treated enclosures. Chemical equilibrium modeling suggested that humic substances could have formed complexes with lanthanum (La from the LMB, rendering it unavailable for intercepting P over the course of the enclosure experiment. Residual lanthanum concentrations in combination dredging and LMB treatments exceeded the Dutch standard 10-fold. Total zooplankton abundance, and particularly Cladocera, increased in all enclosures over the course of the experiment. The limited effect of LMB in the enclosure experiment and the violation of the Dutch La standard when combined with dredging disqualify LMB as an intervention agent in the restoration of the pond.

  1. Revised energy levels of singly ionized lanthanum

    Science.gov (United States)

    Güzelçimen, Feyza; Tonka, Mehdi; Uddin, Zaheer; Bhatti, Naveed Anjum; Windholz, Laurentius; Kröger, Sophie; Başar, Gönül

    2018-05-01

    Based on the experimental wavenumbers of 344 spectral lines from calibrated Fourier transform (FT) spectra as well as wavenumbers of 81 lines from the wavelength tables from literature, the energy of 115 fine structure levels of singly ionized lanthanum has been revised by weighted global fits. The classifications of the lines are provided by numerous previous investigations of lanthanum by different spectroscopic methods and authors. For the high accurate determination of the center of gravity wavenumbers from the experimental spectrum, the hyperfine constants of the involved levels have been taken into account, if possible. For the 94 levels with known hyperfine constants the accuracy of energy values is better than 0.01 cm-1. For 34 levels the magnetic dipole hyperfine constants A have been determined from FT spectra as part of this work. For four of these 34 levels even electric quadrupole hyperfine constants B could be estimated. For levels, which have experimentally unknown hyperfine constants and which are connected only by lines not found in the FT spectra but taken from literature, the uncertainties of energy values are about a factor of 10 higher. A list of all revised level energies together with a compilation of hyperfine structure data is given as well as a list of all lines used.

  2. Lanthanum deposition corresponds to white lesions in the stomach.

    Science.gov (United States)

    Iwamuro, Masaya; Urata, Haruo; Tanaka, Takehiro; Kawano, Seiji; Kawahara, Yoshiro; Kimoto, Katsuhiko; Okada, Hiroyuki

    2018-05-23

    Although lanthanum deposition in the stomach has been most frequently reported to occur as white lesions, no study has investigated whether the white lesions observed during esophagogastroduodenoscopy are truly lanthanum-related. Here, we retrospectively investigated the amount of lanthanum in endoscopic biopsy specimens. We reviewed four patients showing gastric white spots or annular whitish mucosa in the gastric white lesions (Bw) and peripheral mucosa where the white substance was not endoscopically observed (Bp) during biopsy. We also reviewed three patients with diffuse whitish mucosa and three patients with no whitish lesions. We performed scanning electron microscopy and energy dispersive X-ray spectrometry to quantify the lanthanum elements (wt%) in the biopsy specimens. The amount of lanthanum in the Bw ranged from 0.15-0.31 wt%, whereas that of Bp was 0.00-0.13 wt%. The difference was statistically significant (P < 0.05). The amount of lanthanum in the Bw, endoscopically presented with white spots or annular whitish mucosa, was significantly higher than that of no whitish lesions (0.05-0.14 wt%, P < 0.05). The amount of lanthanum was also higher in the diffuse whitish mucosa (0.21-0.23 wt%) compared with no whitish lesions (P < 0.01). This study is the first to reveal that pathological lanthanum deposition corresponds to the endoscopically observed white lesions in the gastric mucosa. Therefore, during esophagogastroduodenoscopy, physicians should pay attention to possible presence of white lesions in patients treated with oral lanthanum carbonate to ensure prompt identification of associated issues. Copyright © 2018 Elsevier GmbH. All rights reserved.

  3. Thermoelectric properties of non-stoichiometric lanthanum sulfides

    International Nuclear Information System (INIS)

    Shapiro, E.; Danielson, L.R.

    1983-01-01

    The lanthanum sulfides are promising candidate materials for high-efficiency thermoelectric applications at temperatures up to 1300 0 C. The nonstoichiometric lanthanum sulfides (LaS /SUB x/ , where 1.33 2 //rho/ can be chosen. The thermal conductivity remains approximately constant with stoichiometry, so a material with an optimum value of α 2 //rho/ should possess the optimum figure-of-merit. Data for the Seebeck coefficient and electrical resistivity of non-stoichiometric lanthanum sulfides is presented, together with structural properties of these materials

  4. Preparation of lanthanum sulfide nanoparticles by thermal decomposition of lanthanum complex

    Institute of Scientific and Technical Information of China (English)

    LI Peisen; LI Huanyong; JIE Wanqi

    2011-01-01

    γ-La2S3 nanoparticles were successfully prepared by thermal decomposition of lanthanum complex La(Et2S2CN)3·phen at low temperature. The obtained sample was characterized by the X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and element analysis. The decomposition mechanism of lanthanum complex was studied by thermogravimetric analyses (TGA). The results showed that the obtained samples were cubic phase particles with uniform sizes among 10-30 nm and γ-La2S3 was prepared by decomposition of La(Et2S2CN)3 phen via La4(Et2S2CN)3 as an intermediate product. The band gap of γ-La2S3 was 2.97 eV, which was bigger than bulk crystal because of pronounced quantum confinement effect.

  5. Lanthanum additions and the toughness of ultra-high strength steels and the determination of appropriate lanthanum additions

    International Nuclear Information System (INIS)

    Garrison, Warren M.; Maloney, James L.

    2005-01-01

    Studies of commercial heats of AF1410 steel suggest that under appropriate conditions additions of rare-earth elements can significantly enhance fracture toughness. This improvement in toughness is not due to an extremely low inclusion volume fraction but is apparently due to the formation of larger and more widely spaced inclusions. The purpose of this work is to discuss our experience in using rare-earth additions to laboratory scale vacuum induction melted and subsequently vacuum arc remelted heats of ultra-high strength steels to achieve inclusion distributions similar to those observed in commercial heats modified with lanthanum additions. The results indicate that lanthanum additions of 0.015 wt.% to low sulfur steels which have been well deoxidized using carbon-vacuum deoxidation can result in lanthanum rich inclusions which are similar in size, volume fraction and spacing to those obtained in commercially produced heats of ultra-high strength steel to which lanthanum has been added. The heat of steel to which lanthanum additions of 0.015 wt.% were made had significantly higher toughness than did the heat of the same steel in which the sulfur had been gettered as small and closely spaced particles of MnS and which had an inclusion volume fraction similar to that of the heat modified by the addition of 0.015 wt.% lanthanum. This improvement in toughness was attributed to an increase in inclusion spacing. An addition of 0.06 wt.% lanthanum was excessive. Such an addition of lanthanum resulted in a huge volume fraction of large cuboidal inclusions which primarily contain lanthanum and oxygen and which are extremely detrimental to toughness

  6. Transparent metals for ultrabroadband electromagnetic waves.

    Science.gov (United States)

    Fan, Ren-Hao; Peng, Ru-Wen; Huang, Xian-Rong; Li, Jia; Liu, Yongmin; Hu, Qing; Wang, Mu; Zhang, Xiang

    2012-04-17

    Making metals transparent, which could lead to fascinating applications, has long been pursued. Here we demonstrate that with narrow slit arrays metallic plates become transparent for extremely broad bandwidths; the high transmission efficiency is insensitive to the metal thickness. This work provides a guideline to develop novel devices, including transparent conducting panels, broadband metamaterials, and antireflective solar cells. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    International Nuclear Information System (INIS)

    Selles, O.

    2006-12-01

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

  8. Lignin-Retaining Transparent Wood.

    Science.gov (United States)

    Li, Yuanyuan; Fu, Qiliang; Rojas, Ramiro; Yan, Min; Lawoko, Martin; Berglund, Lars

    2017-09-11

    Optically transparent wood, combining optical and mechanical performance, is an emerging new material for light-transmitting structures in buildings with the aim of reducing energy consumption. One of the main obstacles for transparent wood fabrication is delignification, where around 30 wt % of wood tissue is removed to reduce light absorption and refractive index mismatch. This step is time consuming and not environmentally benign. Moreover, lignin removal weakens the wood structure, limiting the fabrication of large structures. A green and industrially feasible method has now been developed to prepare transparent wood. Up to 80 wt % of lignin is preserved, leading to a stronger wood template compared to the delignified alternative. After polymer infiltration, a high-lignin-content transparent wood with transmittance of 83 %, haze of 75 %, thermal conductivity of 0.23 W mK -1 , and work-tofracture of 1.2 MJ m -3 (a magnitude higher than glass) was obtained. This transparent wood preparation method is efficient and applicable to various wood species. The transparent wood obtained shows potential for application in energy-saving buildings. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  9. Effect of lanthanum doping on electrical and electromechanical ...

    Indian Academy of Sciences (India)

    Unknown

    temperature, Tc increased with the increase of lanthanum content. ... By adding oxide group softeners, hardeners and stabi- ... pressed with 2% polyvinyl alcohol as binder under a ... study are dependent on temperature and are shown in.

  10. Adsorption of lithium-lanthanum films on W (112) face

    International Nuclear Information System (INIS)

    Gupalo, M.S.; Smereka, T.P.; Palyukh, B.M.; Babkin, G.V.

    1986-01-01

    The method of contact potential difference is employed to study the electron adsorption properties (the work function phi and adsorption heat q) lithium films on a lanthanized W(112) surface. It is found that the work function of mixed lithium-lanthanum films is intermediate between phi of the summands. The presence of lanthanum on a W(112) face reduces the adsorption heat of lithium

  11. Pressure behaviour of the superconducting transition temperature of lanthanum

    International Nuclear Information System (INIS)

    Glocker, R.

    1977-01-01

    The dissertation has the following chapters: 1) Introduction, 2) Fundamentals of the microscopic theory of superconductivity, 3) Calculation of the first momentum of the Eliashberg function, 4) Determination of the average values of frequency, 5) The relativistic cellular method and its application to lanthanum, 6) Results of the calculation of the electron-phonon coupling cosntants for f.c.c. lanthanum, 7) Phonon dispersion and phonon state density. (orig.) [de

  12. Phases in lanthanum-nickel-aluminum alloys

    International Nuclear Information System (INIS)

    Mosley, W.C.

    1992-01-01

    Lanthanum-nickel-aluminum (LANA) alloys will be used to pump, store and separate hydrogen isotopes in the Replacement Tritium Facility (RTF). The aluminum content (y) of the primary LaNi 5 -phase is controlled to produce the desired pressure-temperature behavior for adsorption and desorption of hydrogen. However, secondary phases cause decreased capacity and some may cause undesirable retention of tritium. Twenty-three alloys purchased from Ergenics, Inc. for development of RTF processes have been characterized by scanning electron microscopy (SEM) and by electron microprobe analysis (EMPA) to determine the distributions and compositions of constituent phases. This memorandum reports the results of these characterization studies. Knowledge of the structural characteristics of these alloys is a useful first step in selecting materials for specific process development tests and in interpreting results of those tests. Once this information is coupled with data on hydrogen plateau pressures, retention and capacity, secondary phase limits for RTF alloys can be specified

  13. Synthesis and Stability of Lanthanum Superhydrides

    Energy Technology Data Exchange (ETDEWEB)

    Geballe, Zachary M. [Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Liu, Hanyu [Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Mishra, Ajay K. [Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Permanent address: HP& SRPD, Bhabha Atomic Research Center, Mumbai-85 India; Ahart, Muhtar [Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Somayazulu, Maddury [Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Meng, Yue [HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, Argonne IL 60439 USA; Baldini, Maria [Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Hemley, Russell J. [Institute of Materials Science and Department of Civil and Environmental Engineering, The George Washington University, Washington DC 20052 USA

    2017-12-15

    Recent theoretical calculations predict that megabar pressure stabilizes very hydrogen-rich simple compounds having new clathrate-like structures and remarkable electronic properties including room-temperature superconductivity. X-ray diffraction and optical studies demonstrate that superhydrides of lanthanum can be synthesized with La atoms in an fcc lattice at 170 GPa upon heating to about 1000 K. The results match the predicted cubic metallic phase of LaH10 having cages of thirty-two hydrogen atoms surrounding each La atom. Upon decompression, the fcc-based structure undergoes a rhombohedral distortion of the La sublattice. The superhydride phases consist of an atomic hydrogen sublattice with H-H distances of about 1.1 Å, which are close to predictions for solid atomic metallic hydrogen at these pressures. With stability below 200 GPa, the superhydride is thus the closest analogue to solid atomic metallic hydrogen yet to be synthesized and characterized.

  14. High-temperature corrosion of lanthanum in equimole mixture of sodium and potassium chlorides

    International Nuclear Information System (INIS)

    Kochergin, V.P.; Obozhina, R.N.; Dragoshanskaya, T.I.; Startsev, B.P.

    1984-01-01

    Results of investigation into the process of lanthanum corrosion in the molted equimole NaCl-KCl mixture after the change of test time, temperature and lanthanum trichloride were summarized. It was shown that polarization of lanthanum anode in equimole NaCl-KCl melt is controlled by La 3+ diffusion from near-electrode layer to electrolyte depth, which results in decrease of corrosion rate in time. The established electrochemical properties of metallic lanthanum in equimole NaCl-KCl mixture must be considered when improving the technology of electrochemical production of lanthanum or its alloys of molten chlorides of lanthanum and alkaline metals

  15. The effect of lanthanum applications on drought tolerance in barley

    International Nuclear Information System (INIS)

    Buckingham, S.; Maheswaran, J.; Peverill, K.; Meehan, B.; Stokes, J.

    1998-01-01

    Full text: Glasshouse investigations carried out by the authors on both perlite and soil, have repeatedly shown that several plant species, when treated with lanthanum, retain greater amounts of moisture under water stressed conditions. Dry matter increases under water stress have been observed in some cases. Barley plants watered to 50% field capacity, and show-ing signs of water stress, yielded 18% more dry matter when treated with 5 kg/ha and 10 kg/ha of lanthanum than control plants (P<0.05). The results of these experiments suggest that increased dry matter production in crops under periods of water stress, is likely when previously treated with lanthanum. Consequently, it is conceivable that lanthanum may have potential as an agent that induces drought tolerance in grain crops, grown in low rainfall areas. Subsequent field trials using barley as a test crop at Walpeup, in the Mallee region of Victoria have shown that in a below average rainfall year, combined soil and foliar applications of lanthanum can significantly increase grain yield. This effect was not evident when barley grown on the same soil type was treated with lanthanum under above average rainfall conditions

  16. Artistic transparency

    CERN Document Server

    Antonella Del Rosso

    2016-01-01

    As the Arts@CERN programme testifies, CERN is no stranger to the collision of science and art. Just before Christmas, the Slovak artist Ján Zoričák exhibited his glass artworks at CERN, some of which make use of crystals from the OPAL experiment. We take a look at the artist, the science that inspired him and the techniques that he uses.   It took 10 months to create the 22 glass artworks in the exhibition, six of which make use of lead glass from the calorimeter of OPAL, one of the four main LEP experiments. Ján Zoričák has been a glass sculptor for several decades. In his capable hands, glass seems to take on a new energy, as he uses the contrast in temperature when glass heated for up to 48 hours at extremely high temperatures is exposed to a very cold source until it fractures. The resulting cracks break up the homogeneity and regularity of the glass and play with light and shadow, an effect that is majestically reinforced by finishing and polish...

  17. Study of lanthanum aluminate for cost effective electrolyte material for SOFC

    Science.gov (United States)

    Verma, O. N.; Shahi, A. K.; Singh, P.

    2018-05-01

    The perovskite type electrolyte material LaAlO3 (abbreviated LAO) has been prepared by easy processing of auto-combustion synthesis using lanthanum nitrate and aluminium nitrate salts as precursors and citric acid as the fuel. The XRD analysis reveals that as synthesized material exhibits only single phase having rhombohedral structure. The measured density and theoretical density have been deliberated. The temperature dependent electrical conductivity of LAO increases with increasing the temperature which leads to increased mobility of oxide ion. The major contribution of such a significant value of ionic conductivity of LAO can be inferred to grain boundary resistance.

  18. Preparation and Characterization of Lanthanum Carbonate Octahydrate for the Treatment of Hyperphosphatemia

    Directory of Open Access Journals (Sweden)

    Anqi He

    2013-01-01

    Full Text Available We proposed a new approach to prepare lanthanum carbonate via reactions between lanthanum chloride and NaHCO3. In the reaction, small amount of NaHCO3 solution was firstly added to the acidic lanthanum chloride solution to generate lanthanum carbonate nuclei and then NaHCO3 is added to the lanthanum chloride at a constant speed. This approach makes both precipitation reaction and neutralization reaction take place simultaneously. Consequently, lanthanum carbonate is produced at low pH environment (pH below 4.0 so that the risk of generating lanthanum carbonate hydroxide is reduced. The product of the above reaction is validated by EDTA titration, elemental analysis, and XRD characterization. In addition, we established a FTIR spectroscopic method to identify La(OHCO3 from La2(CO32·8H2O. Lanthanum carbonate exhibits considerable ability to bind phosphate.

  19. Mechanical properties of dense to porous alumina/lanthanum hexaaluminate composite ceramics

    International Nuclear Information System (INIS)

    Negahdari, Zahra; Willert-Porada, Monika; Pfeiffer, Carolin

    2010-01-01

    For development of new composite materials based on lanthanum hexaaluminate and alumina ceramics, a better understanding of the microstructure-properties relationship is essential. In this paper, attention was focused on the evaluation of mechanical properties of lanthanum hexaaluminate/alumina particulate composite. It was found out that the lanthanum hexaaluminate content plays a critical role in determination of the microstructure and mechanical properties of the composite ceramics. In situ formation of plate-like lanthanum hexaaluminate in the ceramic matrix was accompanied with formation of pores so that the microstructure shifted from dense to porous. Increasing the lanthanum hexaaluminate content up to a certain value enhanced the fracture toughness, increased the hardness, and increased the elastic modulus of the composite materials. Further increase in the lanthanum hexaaluminate content degraded the hardness as well as the elastic modulus of composite ceramics. The influence of lanthanum hexaaluminate on mechanical properties was described by means of microstructure, porosity, and intrinsic characteristics of lanthanum hexaaluminate.

  20. Corneal structure and transparency

    Science.gov (United States)

    Meek, Keith M.; Knupp, Carlo

    2015-01-01

    The corneal stroma plays several pivotal roles within the eye. Optically, it is the main refracting lens and thus has to combine almost perfect transmission of visible light with precise shape, in order to focus incoming light. Furthermore, mechanically it has to be extremely tough to protect the inner contents of the eye. These functions are governed by its structure at all hierarchical levels. The basic principles of corneal structure and transparency have been known for some time, but in recent years X-ray scattering and other methods have revealed that the details of this structure are far more complex than previously thought and that the intricacy of the arrangement of the collagenous lamellae provides the shape and the mechanical properties of the tissue. At the molecular level, modern technologies and theoretical modelling have started to explain exactly how the collagen fibrils are arranged within the stromal lamellae and how proteoglycans maintain this ultrastructure. In this review we describe the current state of knowledge about the three-dimensional stromal architecture at the microscopic level, and about the control mechanisms at the nanoscopic level that lead to optical transparency. PMID:26145225

  1. Transparency and product variety

    DEFF Research Database (Denmark)

    Schultz, Christian

    2009-01-01

    We study long run effects of transparency on the consumer side in a differentiated market. Only some consumers know prices. Increasing transparency reduces the equilibrium price, profit and firm entry. This improves welfare and, in most cases, average consumer utility....

  2. Optimal Central Bank Transparency

    NARCIS (Netherlands)

    van der Cruijsen, C.A.B.; Eijffinger, S.C.W.; Hoogduin, L.H.

    2008-01-01

    Should central banks increase their degree of transparency any further? We show that there is likely to be an optimal intermediate degree of central bank transparency. Up to this optimum more transparency is desirable: it improves the quality of private sector inflation forecasts. But beyond the

  3. Optimal central bank transparency

    NARCIS (Netherlands)

    van der Cruijsen, C.A.B.; Eijffinger, S.C.W.; Hoogduin, L.

    2008-01-01

    Should central banks increase their degree of transparency any further? We show that there is likely to be an optimal intermediate degree of central bank transparency. Up to this optimum more transparency is desirable: it improves the quality of private sector inflation forecasts. But beyond the

  4. Optimal central bank transparency

    NARCIS (Netherlands)

    van der Cruijsen, C.A.B.; Eijffinger, S.C.W.; Hoogduin, L.H.

    2010-01-01

    Should central banks increase their degree of transparency any further? We show that there is likely to be an optimal intermediate degree of central bank transparency. Up to this optimum more transparency is desirable: it improves the quality of private sector inflation forecasts. But beyond the

  5. Transparency and Product Variety

    DEFF Research Database (Denmark)

    Schultz, Christian

    We study the long run e¤ects of transparency in a circular town model of a differentiated market. The market is not fully transparent on the consumer side: A fraction of consumers are uninformed about prices. Increasing transparency reduces the equilibrium price, profit and entry of firms. This i...

  6. Transparency in Health Programmes

    OpenAIRE

    Vian, Taryn

    2008-01-01

    Transparency is an important tool for good governance, helping to expose abusive practices including fraud, patronage, corruption, and other abuses of power. Increasing transparency can also enhance accountability by providing performance management information and exposing policies and procedures to oversight. This U4 Brief discusses the role of transparency in preventing corruption in the health sector.

  7. Voluntarism and transparent deliberation

    DEFF Research Database (Denmark)

    Steglich-Petersen, Asbjørn

    2006-01-01

    voluntarism. I argue that transparency to factual questions occurs in practical deliberation in ways parallel to transparency in doxastic deliberation. I argue that this should make us reconsider the appeal to transparency in arguments against doxastic voluntarism, and the wider issue of distinguishing...... theoretical from practical rationality....

  8. Innovative transparent armour concepts

    NARCIS (Netherlands)

    Carton, E.P.; Broos, J.P.F.

    2011-01-01

    Ever since WWII transparent armour consists of a multi-layer of glass panels bonded by thin polymer bond-films using an autoclave process. TNO has worked on the development of innovative transparent armour concepts that are lighter and a have better multi-hit capacity. Two new transparent armour

  9. Macroscopic Optomechanically Induced Transparency

    Science.gov (United States)

    Pate, Jacob; Castelli, Alessandro; Martinez, Luis; Thompson, Johnathon; Chiao, Ray; Sharping, Jay

    Optomechanically induced transparency (OMIT) is an effect wherein the spectrum of a cavity resonance is modified through interference between coupled excitation pathways. In this work we investigate a macroscopic, 3D microwave, superconducting radio frequency (SRF) cavity incorporating a niobium-coated, silicon-nitride membrane as the flexible boundary. The boundary supports acoustic vibrational resonances, which lead to coupling with the microwave resonances of the SRF cavity. The theoretical development and physical understanding of OMIT for our macroscopic SRF cavity is the same as that for other recently-reported OMIT systems despite vastly different optomechanical coupling factors and device sizes. Our mechanical oscillator has a coupling factor of g0 = 2 π . 1 ×10-5 Hz and is roughly 38 mm in diameter. The Q = 5 ×107 for the SRF cavity allows probing of optomechanical effects in the resolved sideband regime.

  10. 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.

  11. Synthesis and stability of lanthanum superhydrides

    Energy Technology Data Exchange (ETDEWEB)

    Geballe, Zachary M.; Liu, Hanyu; Mishra, Ajay K.; Ahart, Muhtar; Somayazulu, Maddury; Baldini, Maria [Geophysical Laboratory, Carnegie Institution, Washington, DC (United States); Meng, Yue [HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, IL (United States); Hemley, Russell J. [Institute of Materials Science and Department of Civil and Environmental Engineering, The George Washington University, Washington, DC (United States)

    2018-01-15

    Recent theoretical calculations predict that megabar pressure stabilizes very hydrogen-rich simple compounds having new clathrate-like structures and remarkable electronic properties including room-temperature superconductivity. X-ray diffraction and optical studies demonstrate that superhydrides of lanthanum can be synthesized with La atoms in an fcc lattice at 170 GPa upon heating to about 1000 K. The results match the predicted cubic metallic phase of LaH{sub 10} having cages of thirty-two hydrogen atoms surrounding each La atom. Upon decompression, the fcc-based structure undergoes a rhombohedral distortion of the La sublattice. The superhydride phases consist of an atomic hydrogen sublattice with H-H distances of about 1.1 Aa, which are close to predictions for solid atomic metallic hydrogen at these pressures. With stability below 200 GPa, the superhydride is thus the closest analogue to solid atomic metallic hydrogen yet to be synthesized and characterized. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Optical and photoemission studies of lanthanum hydrides

    International Nuclear Information System (INIS)

    Peterman, D.J.; Peterson, D.T.; Weaver, J.H.

    1980-01-01

    The results of optical absorptivity and photoemission measurements on lanthanum hydrides, LaH/sub x/ (1.98 less than or equal to x less than or equal to 2.89) are reported. The low energy (hν less than or equal to 0.5 eV) optical features in LaH/sub x/ are attributed to the filling of octahedral sites. Higher energy interband absorption involves states within the d-band complex, analogous to other dihydrides. As x increases above 2.0, the optical features change rapidly due to the increase in the number of occupied octahedral sites. Various band structure studies suggest that LaH 3 might be a semiconductor. Photoemission results show that as x increases, the d-derived states at E/sub F/ are drawn down and that for LaH 2 89 only very weak valence band emission is observed. The hydrogen-derived bonding bands are shown centered approx. 5 eV below E/sub F/. Observed chemical shifts in the La 5p/sub 1/2 3/2/ cores are discussed for 1.98 less than or equal to x less than or equal to 2.89

  13. The art of transparency.

    Science.gov (United States)

    Sayim, Bilge; Cavanagh, Patrick

    2011-01-01

    Artists throughout the ages have discovered a number of techniques to depict transparency. With only a few exceptions, these techniques follow closely the properties of physical transparency. The two best known properties are X-junctions and the luminance relations described by Metelli. X-junctions are seen where the contours of a transparent material cross contours of the surface behind; Metelli's constraints on the luminance relations between the direct and filtered portions of the surface specify a range of luminance values that are consistent with transparency. These principles have been used by artists since the time of ancient Egypt. However, artists also discovered that stimuli can be seen as transparent even when these physical constraints are not met. Ancient Greek artists, for example, were able to depict transparent materials in simple black-and-white line drawings. Artists also learned how to represent transparency in cases where neither X-junctions nor Metelli's constraints could apply: for example, where no portions of the objects behind the transparent material extend beyond it. Many painters convincingly portrayed transparency in these cases by depicting the effects the transparent medium would have on material or object properties. Here, we show how artists employed these and other techniques revealing their anticipation of current formalizations of perceived transparency, and we suggest new, as-yet-untested principles.

  14. Peering into Transparency

    DEFF Research Database (Denmark)

    Christensen, Lars Thøger; Cheney, George

    2015-01-01

    organizational effectiveness and widened democratic practice. Yet, with its most common operationalization, as information, transparency reinstalls a 'purified' notion of communication devoid of mystery, inaccuracy, and (mis)representation. We apply transparency to itself by unpacking its implicit model......The current emphasis on organizational transparency signifies a growing demand for insight, clarity, accountability, and participation. Holding the promise of improved access to valid and trustworthy knowledge about organizations, the transparency pursuit has great potential for enhanced...... of communication and critiquing its obliviousness to the representative nature of transparency-related messages and the attendant complexities of motivation. This critique interrogates the ambiguities and ambivalence of the transparency pursuit and demonstrates how the goals of organizational transparency...

  15. Determination of main components in lanthanum titanates blend

    International Nuclear Information System (INIS)

    Sizonenko, T.N.; Timchenko, A.K.

    1981-01-01

    Conditions for complexonometric determination of lanthanum in the presence of titanium using the disguising of the latter are studied. A method is suggested for lanthanum and titanium determination in a blend of lanthanum titanate which is used to grow monocrystals. Sulfosalicylic acid is chosen as a disguising agent. La has been determined by complexonometric titration using EDTA with xylenol orange in urotropin. The total contents of La and Ti have been determined by titration of EDTA excess with standard solution of zinc sulfate. Ti content has been calculated from the difference between the first two determinations. Reproducibility of Ti and La determination in the blend (n=21) is characterized by the following: at 19.73% La and 57.21% Ti there are (19.72+-0.16)% La and (57.10+-0.22)% Ti, Sr equals 0.0071 and 0.0034, respectively

  16. Electrochemical Deposition of Lanthanum Telluride Thin Films and Nanowires

    Science.gov (United States)

    Chi, Su (Ike); Farias, Stephen; Cammarata, Robert

    2013-03-01

    Tellurium alloys are characterized by their high performance thermoelectric properties and recent research has shown nanostructured tellurium alloys display even greater performance than bulk equivalents. Increased thermoelectric efficiency of nanostructured materials have led to significant interests in developing thin film and nanowire structures. Here, we report on the first successful electrodeposition of lanthanum telluride thin films and nanowires. The electrodeposition of lanthanum telluride thin films is performed in ionic liquids at room temperature. The synthesis of nanowires involves electrodepositing lanthanum telluride arrays into anodic aluminum oxide (AAO) nanoporous membranes. These novel procedures can serve as an alternative means of simple, inexpensive and laboratory-environment friendly methods to synthesize nanostructured thermoelectric materials. The thermoelectric properties of thin films and nanowires will be presented to compare to current state-of-the-art thermoelectric materials. The morphologies and chemical compositions of the deposited films and nanowires are characterized using SEM and EDAX analysis.

  17. Functionalization of lanthanum hydroxide nanowires by atom transfer radical polymerization

    International Nuclear Information System (INIS)

    Zhou Mi; Yuan Jinying; Yuan Weizhong; Yin Yingwu; Hong Xiaoyin

    2007-01-01

    Atom transfer radical polymerization (ATRP) has been used to prepare a core-shell hybrid nanostructure successfully: a hard core of single-crystalline lanthanum hydroxide nanowires and a soft shell of polystyrene (PS) brushes. Transmission electron microscopy (TEM) images indicated that the resulting products presented special structures and different thicknesses of polymer layers. The chemical components and grafted PS quantities of the samples were measured by Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA). The polymers showed narrow polydispersity, which proved that the lanthanum hydroxide nanowires initiated the 'living'/controlled polymerization of styrene. With the modifiability of lanthanum hydroxide nanowires, the solubility increased, which affords a new way to functionalize nanowires

  18. Calcium and lanthanum solid base catalysts for transesterification

    Science.gov (United States)

    Ng, K. Y. Simon; Yan, Shuli; Salley, Steven O.

    2015-07-28

    In one aspect, a heterogeneous catalyst comprises calcium hydroxide and lanthanum hydroxide, wherein the catalyst has a specific surface area of more than about 10 m.sup.2/g. In another aspect, a heterogeneous catalyst comprises a calcium compound and a lanthanum compound, wherein the catalyst has a specific surface area of more than about 10 m.sup.2/g, and a total basicity of about 13.6 mmol/g. In further another aspect, a heterogeneous catalyst comprises calcium oxide and lanthanum oxide, wherein the catalyst has a specific surface area of more than about 10 m.sup.2/g. In still another aspect, a process for preparing a catalyst comprises introducing a base precipitant, a neutral precipitant, and an acid precipitant to a solution comprising a first metal ion and a second metal ion to form a precipitate. The process further comprises calcining the precipitate to provide the catalyst.

  19. Improvement of acid and base resistance of nickel phosphate pigment by the addition of lanthanum cation

    International Nuclear Information System (INIS)

    Onoda, Hiroaki; Matsui, Hironori; Tanaka, Isao

    2007-01-01

    Transition metal phosphates are used as inorganic pigments, however these materials had a weak point for acid and base resistance. Because lanthanum phosphate is insoluble in acidic and basic solution, the addition of lanthanum cation was tried for the improvement of the acid and base resistance of nickel phosphate pigment. The lanthanum-doped nickel phosphates were prepared from phosphoric acid, nickel nitrate, and lanthanum nitrate solution. The additional effects of lanthanum cation were studied on the chemical composition, particle shape and size distribution, specific surface area, color, acid and base resistance of the precipitations and their thermal products

  20. Synthesis and characterization of lanthanum incorporated mesoporous molecular sieves

    International Nuclear Information System (INIS)

    Pesquera, C.; Gonzalez, F.; Blanco, C.; Sanchez, L.

    2004-01-01

    A series of mesoporous materials under reflux conditions have been synthesized with two silicon sources (fumed silica and sodium silicate) and lanthanum added. The following Si/La molar ratio was used in the samples: 100; 75; 50 and 25. The calcined products were characterized by means of X-ray diffraction, nitrogen adsorption isotherms and energy dispersive X-ray spectrometry (EDS). The BET surface area gradually decreases with an increase in the lanthanum content of the LaxMCM-41 samples. Moreover, the average pore size tends to decrease along with the increase in the La content in the samples

  1. Transparency views by media

    International Nuclear Information System (INIS)

    Ikawa, Y.

    2007-01-01

    In this presentation, various problems surrounding the issues of transparency, such as 'What exactly should be transparent?' 'Is all that we want amounting only to transparency?' 'Is it possible to thoroughly implement transparency', etc., are discussed with due consideration for the viewpoints of the wide range of parties concerned involving areas of politics, administration, enterprises, media, individuals, and so on. First of all, the explanation is focused on how the transparency is recognised, as well as how it is regarded as important, for the public at large and the media. Then, based on the concept that transparency is required for what cannot be justified to be secret, we will contemplate what should be transparent in the areas of politics, administration and enterprises, using the case of nuclear issues as example. Next, the discussion will proceed to the point whether the achievement of transparency itself should be the ultimate goal, in the light of taking into consideration the standpoints of individuals and the receivers of the information, in addition to that of the administration, politics, and enterprises. In closing, we will discuss what the necessary measures will be to materialize the complete transparency on the basis of the discussions made thus far. (author)

  2. Plasmonic transparent conductors

    Science.gov (United States)

    Liapis, Andreas C.; Sfeir, Matthew Y.; Black, Charles T.

    2016-09-01

    Many of today's technological applications, such as solar cells, light-emitting diodes, displays, and touch screens, require materials that are simultaneously optically transparent and electrically conducting. Here we explore transparent conductors based on the excitation of surface plasmons in nanostructured metal films. We measure both the optical and electrical properties of films perforated with nanometer-scale features and optimize the design parameters in order to maximize optical transmission without sacrificing electrical conductivity. We demonstrate that plasmonic transparent conductors can out-perform indium tin oxide in terms of both their transparency and their conductivity.

  3. Double optomechanical transparency with direct mechanical interaction

    International Nuclear Information System (INIS)

    Li Ling-Chao; Shi Rao; Xu Jun; Hu Xiang-Ming

    2015-01-01

    We present a mechanism for double transparency in an optomechanical system. This mechanism is based on the coupling of a moving cavity mirror to a second mechanical oscillator. Due to the purely mechanical coupling and the radiation pressure, three pathways are established for excitations of the probe photons into the cavity photons. Destructive interference occurs at two different frequencies, leading to double transparency to the probe field. It is the coupling strength between the mechanical oscillators that determines the locations of the transparency windows. Moreover, the normal splitting appears for the generated Stokes field and the four-wave mixing process is inhibited on resonance. (paper)

  4. Consumer poaching, brand switching, and price transparency

    DEFF Research Database (Denmark)

    Schultz, Christian

    2014-01-01

    This paper addresses price transparency on the consumer side in markets with behavioral price discrimination which feature welfare reducing brand switching. When long-term contracts are not available, an increase in transparency intensifies competition, lowers prices and profits, reduces brand...... switching and benefits consumers and welfare. With long-term contracts, an increase in transparency reduces the use of long-term contracts, leading to more brand switching and a welfare loss. Otherwise, the results are the same as without long-term contracts....

  5. DFT Studies on Interaction between Lanthanum and Hydroxyamide

    Science.gov (United States)

    Pati, Anindita; Kundu, T. K.; Pal, Snehanshu

    2018-03-01

    Extraction and separation of individual rare earth elements has been a challenge as they are chemically very similar. Solvent extraction is the most suitable way for extraction of rare earth elements. Acidic, basic, neutral, chelating are the major classes of extractants for solvent extraction of rare earth elements. The coordination complex of chelating extractants is very selective with positively charged metal ion. Hence they are widely used. Hydroxyamide is capable of forming chelates with metal cations. In this present study interactions of hydroxyamide ligand with lanthanum have been investigated using density functional theory (DFT). Two different functional such as raB97XD and B3LYP are applied along with 6-31+G(d,p) basis set for carbon, nitrogen, hydrogen and SDD basis set for lanthanum. Stability of formed complexes has been evaluated based on calculated interaction energies and solvation energies. Frontier orbital (highest occupied molecular orbital or HOMO and lowest unoccupied molecular orbital or LUMO) energies of the molecule have also been calculated. Electronegativity, chemical hardness, chemical softness and chemical potential are also determined for these complexes to get an idea about the reactivity. From the partial charge distribution it is seen that oxygen atoms in hydroxyamide have higher negative charge. The double bonded oxygen atom present in the hydroxyamide structure has higher electron density and so it forms bond with lanthanum but the singly bonded oxygen atom in the hydroxyamide structure is weaker donor atom and so it is less available for interaction with lanthanum.

  6. Phase segregation in cerium-lanthanum solid solutions

    NARCIS (Netherlands)

    Belliere, V.; Joorst, G; Stephan, O; de Groot, FMF; Weckhuysen, BM

    2006-01-01

    Electron energy-loss spectroscopy (EELS) in combination with scanning transmission electron microscopy ( STEM) reveals that the La enrichment at the surface of cerium-lanthanum solid solutions is an averaged effect and that segregation occurs in a mixed oxide phase. This separation occurs within a

  7. Stability constant of the lanthanum complex with humic acid

    International Nuclear Information System (INIS)

    Jimenez R, M.; Solache R, M. J.

    2008-01-01

    The work described here is a study on the formation of trivalent lanthanum complex with humic acid. Commercial humic acid was purified and then characterized by various analytical techniques. The stability constant determined by a radiochemical method has a worth of log β La , AHA = 13.6. (Author)

  8. LANTHANUM STAINING OF THE SURFACE COAT OF CELLS

    Science.gov (United States)

    Shea, Stephen M.

    1971-01-01

    Among the techniques which have been reported to stain the surface coat of cells, for electron microscopy, is lanthanum staining en bloc. Similarly, the presence of the cationic dye, Alcian blue 8GX, in a primary glutaraldehyde fixative has been reported to improve the preservation of the surface coat of cells of many types; however, the preserved coat is not very electron opaque unless thin sections are counterstained. The present paper shows that for several rat tissues lanthanum staining en bloc is an effective electron stain for the cell surface, giving excellent contrast, if combined sequentially with prefixation in an aldehyde fixative containing Alcian blue. The cationic substance cetylpyridinium chloride was found to have a similar effect to that of Alcian blue in enhancing the lanthanum staining of the surface coat material of the brush border of intestinal epithelial cells. The patterns of lanthanum staining obtained for the tissues studied strikingly resemble those reported in the literature where tissues are stained by several standard methods for demonstrating mucosubstances at the ultrastructural level. This fact and the reproduction of the effect of Alcian blue by cetylpyridinium chloride constitute a persuasive empirical argument that the material visualized is a mucopolysaccharide or mucopolysaccharide-protein complex. PMID:4108476

  9. Investigation of paramagnetic saturation in lanthanum manganese nitrate

    NARCIS (Netherlands)

    Flokstra, Jakob; Meijer, H.C.; Bots, G.J.C.; Verheij, W.A.; van der Marel, L.C.

    1973-01-01

    Paramagnetic saturation of lanthanum manganese nitrate, La2Mn3(NO3)12·24H2O, has been investigated at liquid He temperatures in a static as well as a dynamical way. With the aid of the molecular-field theory the Casimir and Du Pré dispersion and absorption curves are adapted explicitly to the

  10. Photoluminescence properties of cerium oxide nanoparticles as a function of lanthanum content

    International Nuclear Information System (INIS)

    Deus, R.C.; Cortés, J.A.; Ramirez, M.A.; Ponce, M.A.; Andres, J.; Rocha, L.S.R.

    2015-01-01

    Highlights: • CeO 2 nanoparticles were obtained by microwave-hydrothermal method. • Rietveld refinement reveals a cubic structure. • KOH mineralizer agent exhibit weak agglomeration at low temperature and shorter time. - Abstract: The structural and photoluminescent properties at room temperature of CeO 2 and La-doped CeO 2 particles were undertaken. The obtained particles were synthesized by a microwave-assisted hydrothermal method (MAH) under different lanthanum contents. X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Fourier transform Raman (FT-Raman), Ultra-violet spectroscopy (UV–vis) and photoluminescence (PL) measurements were carried out. XRD revealed that the powders are free of secondary phases and crystallize in the cubic structure. Raman data show that increasing La doping content increase oxygen vacancies due to lattice expansion. The UV/vis absorption spectroscopy suggested the presence of intermediate energy levels in the band gap of structurally ordered powders. Lanthanum addition creates oxygen vacancies and shifts the photoluminescence in the low energy range leading to intense PL emission

  11. Photoluminescence properties of cerium oxide nanoparticles as a function of lanthanum content

    Energy Technology Data Exchange (ETDEWEB)

    Deus, R.C. [Universidade Estadual Paulista, Unesp —Faculdade de Engenharia de Guaratinguetá, Av. Dr Ariberto Pereira da Cunha 333, Bairro Pedregulho, P.O. Box 355, 12.516-410 Guaratinguetá, São Paulo, Brazil, (Brazil); Cortés, J.A., E-mail: leandrosrr89@gmail.com [Universidade Estadual Paulista, Unesp —Faculdade de Engenharia de Guaratinguetá, Av. Dr Ariberto Pereira da Cunha 333, Bairro Pedregulho, P.O. Box 355, 12.516-410 Guaratinguetá, São Paulo, Brazil, (Brazil); Ramirez, M.A. [Universidade Estadual Paulista, Unesp —Faculdade de Engenharia de Guaratinguetá, Av. Dr Ariberto Pereira da Cunha 333, Bairro Pedregulho, P.O. Box 355, 12.516-410 Guaratinguetá, São Paulo, Brazil, (Brazil); Ponce, M.A. [Instituto de Investigaciones en Ciencia y Tecnología de Materiales (INTEMA) (CONICET-Universidad Nacional de Mar del Plata), Juan B. Justo 4302, 7600 Mar del Plata (Argentina); Andres, J. [Laboratório Interdisciplinar em Cerâmica, Instituto de Química, Universidade Estadual Paulista, P.O. Box 355, 14801-907 Araraquara, São Paulo (Brazil); Rocha, L.S.R. [Universidade Estadual Paulista, Unesp —Faculdade de Engenharia de Guaratinguetá, Av. Dr Ariberto Pereira da Cunha 333, Bairro Pedregulho, P.O. Box 355, 12.516-410 Guaratinguetá, São Paulo, Brazil, (Brazil); and others

    2015-10-15

    Highlights: • CeO{sub 2} nanoparticles were obtained by microwave-hydrothermal method. • Rietveld refinement reveals a cubic structure. • KOH mineralizer agent exhibit weak agglomeration at low temperature and shorter time. - Abstract: The structural and photoluminescent properties at room temperature of CeO{sub 2} and La-doped CeO{sub 2} particles were undertaken. The obtained particles were synthesized by a microwave-assisted hydrothermal method (MAH) under different lanthanum contents. X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Fourier transform Raman (FT-Raman), Ultra-violet spectroscopy (UV–vis) and photoluminescence (PL) measurements were carried out. XRD revealed that the powders are free of secondary phases and crystallize in the cubic structure. Raman data show that increasing La doping content increase oxygen vacancies due to lattice expansion. The UV/vis absorption spectroscopy suggested the presence of intermediate energy levels in the band gap of structurally ordered powders. Lanthanum addition creates oxygen vacancies and shifts the photoluminescence in the low energy range leading to intense PL emission.

  12. Cationic copolymerization of cycloaliphatic epoxy resin with an spirobislactone with lanthanum triflate as initiator

    International Nuclear Information System (INIS)

    Fernandez, Xavier; Ramis, Xavier; Salla, Josep M.

    2005-01-01

    3,4-Epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate (ECH) was cured with different proportions of 1,6-dioxaspiro[4,4]nonane-2,7-dione (s(γ-BL)) using lanthanum triflate as a catalyst. DSC was used to obtain kinetic data associated to the curing process by means of series of non-isothermal experiments. Fourier transform infrared spectroscopy in attenuated total reflection mode (FT-IR/ATR) was used to study the evolution of the epoxide group in order to compare experimental isothermal data with simulated isothermal data. The complexity of the process itself enabled us to compare different procedures for obtaining isoconversional data and to determine the kinetic model that best describes the curing process. An increase in the proportion of s(γ-BL) increases the speed of the curing process. By means of applying isoconversional methods to dynamic experimental data, we observed that an increase in the proportion of s(γ-BL) leads to an overall decrease in the activation energy for the different formulations. Kinetic parameters that were determined using both differential and integral isoconversional procedures were compared. This allowed us to analyze and to discuss the usefulness of different methods in order to obtain a suitable kinetic triplet at each step of the curing of the ECH/s(γ-BL) system using lanthanum triflate as a catalyst

  13. Transparency of Banking Supervisors

    NARCIS (Netherlands)

    Liedorp, Franka; Mosch, Robert; van der Cruijsen, Carin; de Haan, Jakob

    Following Eijffinger and Geraats (2006), this paper constructs an index of transparency of banking supervisors that takes political, economic, procedural, policy, and operational transparency into account. Based on a survey, the index is constructed for 24 banking supervisors. The average score is

  14. Epilogue: degrees of transparency

    NARCIS (Netherlands)

    Hengeveld, K.

    2011-01-01

    In this epilogue the results of the analyses of four different languages in the preceding papers are compared. It is shown that the degrees of transparency of these languages can be represented on an implicational scale, and that the features themselves can be ranked on a transparency scale as well.

  15. On color transparency

    International Nuclear Information System (INIS)

    Jennings, B.K.; Miller, G.A.

    1989-10-01

    A quantum mechanical treatment of high momentum transfer nuclear processes is presented. Color transparency, the suppression of initial and final state interaction effects, is shown to arise from using the closure approximation. New conditions for the appearance of color transparency are derived

  16. Understanding modern transparency

    NARCIS (Netherlands)

    Meijer, A.J.|info:eu-repo/dai/nl/172436729

    2009-01-01

    Proponents and opponents fiercely debate whether computer-mediated transparency has a positive effect on trust in the public sector. This article enhances our understanding of transparency by presenting three perspectives: a premodern, modern and post-modern perspective, and analyzing the basic

  17. Introduction: The Transparency Issue

    NARCIS (Netherlands)

    Teurlings, J.; Stauff, M.

    2014-01-01

    Besides giving an overview on the individual contributions, this introduction to the special issue on transparency delineates a conceptual context for a critical analysis of the contemporary discourse on transparency and the media mechanisms related to it. It focuses on three ambivalences inherent

  18. EU Transparency Register

    NARCIS (Netherlands)

    Mańko, R.; Thiel, M.; Bauer, E.

    2014-01-01

    Widespread lobbying in the EU institutions has led to criticism regarding the transparency and accountability of the EU's decision-making process. In response to these concerns, the Parliament set up its transparency register in 1995, followed by the Commission in 2008. The two institutions merged

  19. Advice on Admissions Transparency

    Science.gov (United States)

    Australian Government Tertiary Education Quality and Standards Agency, 2018

    2018-01-01

    Admissions transparency means that prospective domestic undergraduate students can easily find good quality admissions information that allows them to compare courses and providers and make informed study choices. In October 2016 the Higher Education Standards Panel (HESP) made recommendations to achieve greater transparency in higher education…

  20. Privacy transparency patterns

    NARCIS (Netherlands)

    Siljee B.I.J.

    2015-01-01

    This paper describes two privacy patterns for creating privacy transparency: the Personal Data Table pattern and the Privacy Policy Icons pattern, as well as a full overview of privacy transparency patterns. It is a first step in creating a full set of privacy design patterns, which will aid

  1. Peering into Transparency

    DEFF Research Database (Denmark)

    Christensen, Lars Thøger; Cheney, George

    and trustworthy knowledge about contemporary organizations, the transparency discourse has significant democratic potential. Yet, its most common operationalization – as information availability – reinstalls a “purified” notion of communication devoid of mystery, inaccuracy and misrepresentation. In this paper......The current emphasis on organizational and institutional transparency – driven by NGOs, inquisitive media, critical investors and other engaged stakeholders – signifies a growing demand for insight, clarity, participation and democracy. Holding the promise of improved access to valid......, we apply transparency to itself by unpacking its implicit model of communication and critiquing its ignorance towards the representative nature of current transparency practices. The critique unfolds the ambiguous nature of the transparency pursuit and demonstrates how its desire for insight, clarity...

  2. Dominant investors and strategic transparency

    NARCIS (Netherlands)

    Perotti, E.C.; von Thadden, E.-L.

    1998-01-01

    This paper studies product market competition under a strategic transparency decision. Dominant investors can influence information collection in the financial market, and thereby corporate transparency, by affecting market liquidity or the cost of information collection. More transparency on a

  3. Dominant investors and strategic transparency

    NARCIS (Netherlands)

    Perotti, E.C.; von Thadden, E.-L.

    1999-01-01

    This paper studies product market competition under a strategic transparency decision. Dominant investors can influence information collection in the financial market, and thereby corporate transparency, by affecting market liquidity or the cost of information collection. More transparency on a

  4. Transparent lithium-ion batteries

    KAUST Repository

    Yang, Y.; Jeong, S.; Hu, L.; Wu, H.; Lee, S. W.; Cui, Y.

    2011-01-01

    Transparent devices have recently attracted substantial attention. Various applications have been demonstrated, including displays, touch screens, and solar cells; however, transparent batteries, a key component in fully integrated transparent

  5. Transport kinetics of hydrogen permeable lanthanum tungstate

    Energy Technology Data Exchange (ETDEWEB)

    Falkenstein, Andreas

    2017-01-24

    The electrical conductivity relaxation technique is a widely used method to determine the oxygen transport parameters of mixed ionic-electronic conductors. In recent years, it has been modified to investigate the hydration behavior of proton conducting mixed conductors, giving access to up to four transport parameters in a single relaxation experiment, the diffusion coefficients and surface reaction rates of hydrogen and oxygen. In this work, the transport properties of the fluorite type protonic conductor lanthanum tungstate have been investigated by means of electrical conductivity relaxation. The experiments were performed in a temperature range from 650 C to 950 C, in a pO{sub 2} range from 3 mbar to 100 mbar and in a pH{sub 2}O range from 10 mbar to 100 mbar and in dry atmosphere. At high temperatures, the conductivity relaxation curve follows the expected two-fold non-monotonic behavior upon hydration. At low temperatures, however, the contribution of the fast hydrogen kinetic decreases and by a further decrease of the temperature, the relaxation shows two-fold monotonic behavior. The power factors - the contribution of each single fold relaxation curve to the resulting two-fold relaxation curve, which is a superposition - have been derived to explain the behavior mentioned above. The activation energy of the oxygen incorporation is rather low. Hence, oxidation experiments were performed in dry atmospheres in order to investigate if the origin of the oxygen species is relevant. The results revealed higher activation energies, which was expected, but also higher absolute values of the surface reaction rate and the diffusion coefficient. Oxidation experiments with increasing humidity revealed that the increased diffusivity cannot be attributed to the total concentrations of electron holes and proton interstitials. First experiments using spectroscopic relaxation, which is dependent on the concentration of hydroxy-anions only, were performed. Absorption bands

  6. Broadband plasmon induced transparency in terahertz metamaterials

    KAUST Repository

    Zhu, Zhihua

    2013-04-25

    Plasmon induced transparency (PIT) could be realized in metamaterials via interference between different resonance modes. Within the sharp transparency window, the high dispersion of the medium may lead to remarkable slow light phenomena and an enhanced nonlinear effect. However, the transparency mode is normally localized in a narrow frequency band, which thus restricts many of its applications. Here we present the simulation, implementation, and measurement of a broadband PIT metamaterial functioning in the terahertz regime. By integrating four U-shape resonators around a central bar resonator, a broad transparency window across a frequency range greater than 0.40 THz is obtained, with a central resonance frequency located at 1.01 THz. Such PIT metamaterials are promising candidates for designing slow light devices, highly sensitive sensors, and nonlinear elements operating over a broad frequency range. © 2013 IOP Publishing Ltd.

  7. Broadband plasmon induced transparency in terahertz metamaterials

    International Nuclear Information System (INIS)

    Zhu Zhihua; Yang Xu; Gu Jianqiang; Jiang Jun; Tian Zhen; Han Jiaguang; Zhang Weili; Yue Weisheng; Tonouchi, Masayoshi

    2013-01-01

    Plasmon induced transparency (PIT) could be realized in metamaterials via interference between different resonance modes. Within the sharp transparency window, the high dispersion of the medium may lead to remarkable slow light phenomena and an enhanced nonlinear effect. However, the transparency mode is normally localized in a narrow frequency band, which thus restricts many of its applications. Here we present the simulation, implementation, and measurement of a broadband PIT metamaterial functioning in the terahertz regime. By integrating four U-shape resonators around a central bar resonator, a broad transparency window across a frequency range greater than 0.40 THz is obtained, with a central resonance frequency located at 1.01 THz. Such PIT metamaterials are promising candidates for designing slow light devices, highly sensitive sensors, and nonlinear elements operating over a broad frequency range. (paper)

  8. Fabrication of mesoporous and high specific surface area lanthanum carbide-carbon nanotube composites

    International Nuclear Information System (INIS)

    Biasetto, L.; Carturan, S.; Maggioni, G.; Zanonato, P.; Bernardo, P. Di; Colombo, P.; Andrighetto, A.; Prete, G.

    2009-01-01

    Mesoporous lanthanum carbide-carbon nanotube composites were produced by means of carbothermal reaction of lanthanum oxide, graphite and multi-walled carbon nanotube mixtures under high vacuum. Residual gas analysis revealed the higher reactivity of lanthanum oxide towards carbon nanotubes compared to graphite. After sintering, the composites revealed a specific surface area increasing with the amount of carbon nanotubes introduced. The meso-porosity of carbon nanotubes was maintained after thermal treatment.

  9. Nanoscale assembly of lanthanum silica with dense and porous interfacial structures.

    Science.gov (United States)

    Ballinger, Benjamin; Motuzas, Julius; Miller, Christopher R; Smart, Simon; Diniz da Costa, João C

    2015-02-03

    This work reports on the nanoscale assembly of hybrid lanthanum oxide and silica structures, which form patterns of interfacial dense and porous networks. It was found that increasing the molar ratio of lanthanum nitrate to tetraethyl orthosilicate (TEOS) in an acid catalysed sol-gel process alters the expected microporous metal oxide silica structure to a predominantly mesoporous structure above a critical lanthanum concentration. This change manifests itself by the formation of a lanthanum silicate phase, which results from the reaction of lanthanum oxide nanoparticles with the silica matrix. This process converts the microporous silica into the denser silicate phase. Above a lanthanum to silica ratio of 0.15, the combination of growth and microporous silica consumption results in the formation of nanoscale hybrid lanthanum oxides, with the inter-nano-domain spacing forming mesoporous volume. As the size of these nano-domains increases with concentration, so does the mesoporous volume. The absence of lanthanum hydroxide (La(OH)3) suggests the formation of La2O3 surrounded by lanthanum silicate.

  10. Distribution of lanthanum and neodymium in Di(2-ethlhexyl) phosphoric acid and tributylphosphate

    International Nuclear Information System (INIS)

    Kraikaew, J.; Suparith, N.; Pruantonsai, P.

    1994-01-01

    Lanthanum and neodymium are among the high quantity elements in mixed rare earth from monazite processing. The popular rare earth separation process is liquid-liquid extraction. This research was carried out to study lanthanum and neodymium distribution in two extractants, di(2-ethylhexyl) phosphoric acid and tributylphosphate. The experimental results show that neodymium distributes in both extractants better than lanthanum. The distribution of both elements are higher at low acidity than at high acidity. Quick and rough investigation by calculating the ratio of distribution coefficient of neodymium to lanthanum in each extractant indicated that La-nd separation efficiency of Di(2-ethylhexyl) phosphoric acid is higher than that of tributylphosphate

  11. A Dictionary for Transparency

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.

    2001-11-15

    There are many terms that are used in association with the U.S. Defense Threat Reduction Agency (DTRA) Transparency Project associated with the Mayak Fissile Materials Storage Facility. This is a collection of proposed definitions of these terms.

  12. Subscribing to Transparency

    DEFF Research Database (Denmark)

    He, Yinghua; Nielsson, Ulf; Guo, Hong

    2014-01-01

    The paper empirically explores how more trade transparency affects market liquidity. The analysis takes advantage of a unique setting in which the Shanghai Stock Exchange offered more trade transparency to market participants subscribing to a new software package. First, the results show...... that the additional data disclosure increased trading activity, but also increased transactions costs through wider bid-ask spreads. Thus, in contrast to popular policy belief, the paper finds that more transparency need not improve market liquidity. Second, the paper finds a particularly strong immediate liquidity...... impact accompanied by altered trading behavior, which suggests a significant impact on institutional traders subscribing relatively early. Lastly, since the effective level of market transparency is bound to depend on how many traders are subscribing to the data, the study can empirically establish...

  13. Color transparency study group

    International Nuclear Information System (INIS)

    Appel, J.A.; Pordes, S.; Botts, J.; Bunce, G.; Farrar, G.

    1990-01-01

    The group studied the relatively new notion of color transparency, discussed present experimental evidence for the effect, and explored several ideas for future experiments. This write-up summarizes these discussions. 11 refs., 1 fig

  14. Subscribing to Transparency

    DEFF Research Database (Denmark)

    He, Yinghua; Nielsson, Ulf; Guo, Hong

    The paper empirically explores how more trade transparency affects market liquidity. The analysis takes advantage of a unique setting in which the Shanghai Stock Exchange offered more trade transparency to market participants subscribing to a new software package. First, the results show...... that the additional data disclosure increased trading activity, but also increased transactions costs through wider bid-ask spreads. Thus, in contrast to popular policy belief, the paper finds that more transparency need not improve market liquidity. Second, the paper finds a particularly strong immediate liquidity...... impact accompanied by altered trading behavior, which suggests a significant impact on institutional traders subscribing relatively early. Lastly, since the effective level of market transparency is bound to depend on how many traders are subscribing to the data, the study can empirically establish...

  15. Nanoscale photoelectron ionisation detector based on lanthanum hexaboride

    International Nuclear Information System (INIS)

    Zimmer, C.M.; Kunze, U.; Schubert, J.; Hamann, S.; Doll, T.

    2011-01-01

    A nanoscale ioniser is presented exceeding the limitation of conventional photoionisation detectors. It employs accelerated photoelectrons that allow obtaining molecule specificity by the tuning of ionisation energies. The material lanthanum hexaboride (LaB 6 ) is used as air stable photo cathode. Thin films of that material deposited by pulsed laser deposition (PLD) show quantum efficiency (QE) in the range of 10 -5 which is comparable to laser photo stimulation results. A careful treatment of the material yields reasonable low work functions even after surface reoxidation which opens up the possibility of using ultraviolet light emitting diodes (UV LEDs) in replacement of discharge lamps. Schematic diagram of a photoelectron ionisation detector (PeID) operating by an electron emitter based on the photoelectric effect of lanthanum hexaboride. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Preparation of lanthanum ferrite powder at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Andoulsi, R.; Horchani-Naifer, K.; Ferid, M., E-mail: karima_horchani@yahoo.com [Physical Chemistry Laboratory of Mineral Materials and their Applications, Hammam-Lif (Tunisia)

    2012-01-15

    Single lanthanum ferrite phase was successfully prepared at low processing temperature using the polymerizable complex method. To implement this work, several techniques such as differential scanning calorimetry, X-ray diffraction, Fourier Transform Infrared Spectroscopy, scanning electron microscopy and BET surface area measurements were used. Throw the obtained results, it was shown that steps of preparing the powder precursor and temperature of its calcination are critical parameters for avoiding phase segregation and obtaining pure lanthanum ferrite compound. Thus, a single perovskite phase was obtained at 600 deg C. At this temperature, the powder was found to be fine and homogeneous with an average crystallite size of 13 nm and a specific surface area of 12.5 m{sup 2}.g{sup -1}. (author)

  17. P -type transparent conducting oxides

    International Nuclear Information System (INIS)

    Zhang, Kelvin H L; Xi, Kai; Blamire, Mark G; Egdell, Russell G

    2016-01-01

    Transparent conducting oxides constitute a unique class of materials combining properties of electrical conductivity and optical transparency in a single material. They are needed for a wide range of applications including solar cells, flat panel displays, touch screens, light emitting diodes and transparent electronics. Most of the commercially available TCOs are n -type, such as Sn doped In 2 O 3 , Al doped ZnO, and F doped SnO 2 . However, the development of efficient p -type TCOs remains an outstanding challenge. This challenge is thought to be due to the localized nature of the O 2 p derived valence band which leads to difficulty in introducing shallow acceptors and large hole effective masses. In 1997 Hosono and co-workers (1997 Nature 389 939) proposed the concept of ‘chemical modulation of the valence band’ to mitigate this problem using hybridization of O 2 p orbitals with close-shell Cu 3 d 10 orbitals. This work has sparked tremendous interest in designing p -TCO materials together with deep understanding the underlying materials physics. In this article, we will provide a comprehensive review on traditional and recently emergent p -TCOs, including Cu + -based delafossites, layered oxychalcogenides, nd 6 spinel oxides, Cr 3+ -based oxides (3 d 3 ) and post-transition metal oxides with lone pair state (ns 2 ). We will focus our discussions on the basic materials physics of these materials in terms of electronic structures, doping and defect properties for p -type conductivity and optical properties. Device applications based on p -TCOs for transparent p – n junctions will also be briefly discussed. (topical review)

  18. AB initio energetics of lanthanum substitution in ferroelectric bismuth titanate

    International Nuclear Information System (INIS)

    Shah, S.H.

    2012-01-01

    Density functional theory based electronic structure calculations play a vital role in understanding, controlling and optimizing physical properties of materials at microscopic level. In present study system of interest is bismuth titanate (Bi/sub 4/Ti/sub 3/O/sub 12/)/(BIT) which has wide range of applications such as a high temperature piezoelectric and one of the best material for memory devices. However, it also suffers from serious issues such as oxygen vacancies which degrade its performance as a memory element and piezoelectric material. In this context, the bulk and defect properties of orthorhombic bismuth titanate (Bi/sub 4/Ti/sub 3/O/sub 12/) and bismuth lanthanum titanate (Bi/sub 3.25/La/sub 0.75/Ti/sub 3/O/sub 12/)/(BLT, x=0.75) were investigated by using first principles calculations and atomistic thermodynamics. Heats of formation, valid chemical conditions for synthesis, lanthanum substitution energies and oxygen and bismuth vacancy formation energies were computed. The study improves understanding of how native point defects and substitutional impurities influence the ferroelectric properties of these layered perovskite materials. It was found that lanthanum incorporation could occur on either of the two distinct bismuth sites in the structure and that the effect of substitution is to increase the formation energy of nearby native oxygen vacancies. The results provide direct atomistic evidence over a range of chemical conditions for the suggestion that lanthanum incorporation reduces the oxygen vacancy concentration. Oxygen vacancies contribute to ferroelectric fatigue by interacting strongly with domain walls and therefore a decrease in their concentration is beneficial. (orig./A.B.)

  19. Electrical behaviour of strontium-doped lanthanum manganite interfaces

    DEFF Research Database (Denmark)

    Koch, Søren; Hendriksen, P.V.; Jacobsen, Torben

    2005-01-01

    The contact resistance of strontium-doped lanthanum manganite (LSM) contact pairs is investigated by polarisation analysis at different temperatures and atmospheres. The ceramic contacts have a high contact resistance, and strongly nonlinear current–voltage behaviour is observed at low temperatur....... The nonlinear behaviour is ascribed to the presence of energy barriers at the contact interface. Generally, point contacts showed a more linear behaviour than plane contact interfaces....

  20. Effect of pressure on the magnetic properties of lanthanum manganite

    International Nuclear Information System (INIS)

    Gonchar', L. E.; Leskova, Yu. V.; Nikiforov, A. E.; Kozlenko, D. P.

    2010-01-01

    The crystalline structure of pure lanthanum manganite under external hydrostatic pressure has been studied. The behavior of magnetic properties and nuclear magnetic resonance (NMR) spectra under these conditions is theoretically predicted. It is shown that an increase in the Neel temperature with pressure is not only caused by the general contraction of the crystal, but is also related to certain peculiarities in the baric behavior of the orbital structure.

  1. Eutrophication management in surface waters using lanthanum modified bentonite

    DEFF Research Database (Denmark)

    Copetti, Diego; Finsterle, Karin; Marziali, Laura

    2016-01-01

    This paper reviews the scientific knowledge on the use of a lanthanum modified bentonite (LMB) to manage eutrophication in surface water. The LMB has been applied in around 200 environments worldwide and it has undergone extensive testing at laboratory, mesocosm, and whole lake scales. The availa......This paper reviews the scientific knowledge on the use of a lanthanum modified bentonite (LMB) to manage eutrophication in surface water. The LMB has been applied in around 200 environments worldwide and it has undergone extensive testing at laboratory, mesocosm, and whole lake scales....... The available data underline a high efficiency for phosphorus binding. This efficiency can be limited by the presence of humic substances and competing oxyanions. Lanthanum concentrations detected during a LMB application are generally below acute toxicological threshold of different organisms, except in low...... alkalinity waters. To date there are no indications for long-term negative effects on LMB treated ecosystems, but issues related to La accumulation, increase of suspended solids and drastic resources depletion still need to be explored, in particular for sediment dwelling organisms. Application of LMB...

  2. Physiological responses in barley to applications of lanthanum

    International Nuclear Information System (INIS)

    Reddy, N.; Maheswaran, J.; Peverill, K.; Meehan, B.

    1998-01-01

    Full text: Chinese research and glasshouse investigations carried out in Victoria by the authors have shown that several plant species, when treated with Rare Earth Elements (REEs), retain greater amounts of moisture under water stressed conditions. The physiological adaptation of the plant to retain moisture in response to REE treatment however, has not been investigated. A glasshouse trial is currently in progress to study the physiological and agronomic responses of barley (cv. Schooner) grown in pots to application of lanthanum (0, 5 and 10 kg/ha), at a concentration of 0.05%, under well-watered (field capacity) and water-deficit (25 - 30% field capacity) conditions. Lanthanum was applied both directly to the soil and as a foliar spray. The physiological measurements include, photosynthetic rate, leaf water potential, osmotic potential, relative water content, stomatal conductance and water use efficiency. Measured agronomic parameters include plant height, tiller production, leaf area development, total grain weight, total biomass, root and shoot ratio and harvest index. Analysis of plant tissue for N, P, K, Ca, Mg, Zn and La to study the relationship between application of REE and nutrient uptake is also being carried out. The paper discusses physiological and agronomic changes in barley plants in response to treatment with lanthanum, under conditions of water stress

  3. Radiation-shielding transparent material

    International Nuclear Information System (INIS)

    Kusumeki, Asao.

    1983-01-01

    Purpose : To obtain radiation-shielding transparent material having a high resistivity to the radioactive rays or light irradiation which is greater at least by two digits as compared with lead glass. Constitution : The shielding material is composed of a saturated aqueous solution zinc iodide. Zinc iodide (specific gravity of 4.2) is dissolved by 430 g into 100 cc of water at a temperature of 20 0 C and forms a heavy liquid with a specific gravity of 2.80. The radiation length of the heavy liquid is 3.8 cm which is 1.5 times as large as lead glass. The light transmission is greater than 95% in average. Furthermore, by adding hypophosphorous acid as a reducing agent to the aqueous solution of the lead iodide, the material is stabilized against the irradiation of light or radioactive rays and causes no discoloration for a long time. (Moriyama, K.)

  4. Effects of the wet air on the properties of the lanthanum oxide and lanthanum aluminate thin films

    International Nuclear Information System (INIS)

    Jun, Jin Hyung; Choi, Doo Jin

    2006-01-01

    Lanthanum oxide and lanthanum aluminate thin films were deposited on Si substrates. The as-grown films were stored in wet ambient and dry ambient for days and annealed after storage and also the structural and the electrical properties of the films were investigated. As the storage time increased, the La 2 O 3 films stored in wet ambient showed rapid reaction with moisture and the properties degraded. In case of the LAO films, although the thickness of the film also increased during hydration, the properties of the film did not so much changed due to the role of the incorporated aluminum. The LAO films showed better hydration resistance characteristics and so more suitable for conventional wet cleaning process in semiconductor fabrication

  5. Effect of additions of cerium, lanthanum, and zirconium on the state of plantinum and the activity of aluminoplatinum catalysts for the complete oxidation of hydrocarbons

    International Nuclear Information System (INIS)

    Drozdov, V.A.; Davydov, A.A.; Popovskii, V.V.; Tsyrul'nikov, P.G.

    1986-01-01

    It is shown from an analysis of the diffuse reflectance spectra that additions of cerium, lanthanum or zirconium to aluminoplatinum catalyst stabilize the platinum in an oxidized state. This leads to a change in the specific catalytic activity (SCA) towards the total oxidation of methane and butane. The SCA of modified, reduced samples is greater than the SCA of samples that were calcined in air. This is because of the greater activity of metallic platinum compared to the ionic form

  6. Electromagnetically induced transparency with matched pulses

    International Nuclear Information System (INIS)

    Harris, S.E.

    1993-01-01

    In the last several years there have been studies and experiments showing how, by applying an additional laser beam, optically-thick transitions may be rendered nearly transparent to probing radiation. This transparency results from a quantum interference, very much like a Fano interference, which is established by the additional laser. This talk describes the difference between the quantum interference as exhibited by an independent atom and by an optically-thick ensemble of atoms. We find that an ensemble of atoms establishes transparency through a strong nonlinear interaction which, for a lambda system, tends to generate a matching temporal envelope on the complementary transition. For a ladder system, phase conjugate pulses are generated and, after a characteristic distance, establish transparency. The transparency of an optically-thick medium is therefore not a Beer's law superposition of the independent atom response. To transmit a pulse through an otherwise opaque media, the front edge of the complementary pulse should lead, in the manner of open-quotes counter-intuitiveclose quotes adiabatic transfer, the front edge of the pulse which is to be rendered transparent. Thereafter the pulses should be matched or, for a ladder system, phase-conjugately matched

  7. Evaluating the impact of the Extractive Industries Transparency Initiative (EITI) on corruption in Zambia

    NARCIS (Netherlands)

    P. Fenton Villar (Paul); E. Papyrakis (Elissaios)

    2016-01-01

    textabstractThe Extractive Industries Transparency Initiative (EITI) is internationally recognised as a leading anti-corruption scheme, which promotes transparency, accountability and good governance of public oil, gas, and mining revenues. This article provides the first rigorous quantitative

  8. Strengthening and elongation mechanism of Lanthanum-doped Titanium-Zirconium-Molybdenum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Ping, E-mail: huping1985@126.com [School of Metallurgy Engineering, Xi’an University of Architecture and Technology, Xi’an 710055 (China); Jinduicheng Molybdenum Co., Ltd., Xi’an 710068 (China); Hu, Bo-liang; Wang, Kuai-she; Song, Rui; Yang, Fan [School of Metallurgy Engineering, Xi’an University of Architecture and Technology, Xi’an 710055 (China); Yu, Zhi-tao [Ruifulai Tungsten & Molybdenum Co., Ltd., Xi’an 721914 (China); Tan, Jiang-fei [School of Metallurgy Engineering, Xi’an University of Architecture and Technology, Xi’an 710055 (China); Cao, Wei-cheng; Liu, Dong-xin; An, Geng [Jinduicheng Molybdenum Co., Ltd., Xi’an 710068 (China); Guo, Lei [Ruifulai Tungsten & Molybdenum Co., Ltd., Xi’an 721914 (China); Yu, Hai-liang [School of Mechanical, Materials and Mechatronics Engineering, University of Wollongong, NSW 2522 (Australia)

    2016-12-15

    The microstructural contributes to understand the strengthening and elongation mechanism in Lanthanum-doped Titanium-Zirconium-Molybdenum alloy. Lanthanum oxide particles not only act as heterogeneous nucleation core, but also act as the second phase to hinder the grain growth during sintering crystallization. The molybdenum substrate formed sub-grain under the effect of second phase when the alloy rolled to plate.

  9. Studies on the promotion of nickel—alumina coprecipitated catalysts: II. Lanthanum oxide

    NARCIS (Netherlands)

    Lansink Rotgerink, H.G.J.; Paalman, R.P.A.M.; van Ommen, J.G.; Ross, J.R.H.

    1988-01-01

    Two series of lanthanum promoted nickel—alumina catalysts have been prepared by coprecipitation of the metal nitrates, using potassium carbonate. The molar ratio between nickel and the sum of aluminium and lanthanum was kept constant at 2.5 or 9.0 within each series. The calcination and reduction of

  10. Supporting Transparency between Students

    DEFF Research Database (Denmark)

    Dalsgaard, Christian

    The paper presents the results of a case study that explores the potentials of weblogs and social bookmarking to support transparency in a university course. In the course, groups of students used weblogs and social bookmarking in their work. The objective of the case was to empower students...... by providing them with tools that would be visible to the other students in the course, thus, making students’ ideas, thoughts and questions visible to the other students in the course. The paper concludes that use of digital media for transparency can support empowerment of students and inspiration among...... students in a course, but that the challenge is to create a balance between personal tools and tools for collaborative group work that are also suitable for transparency between students....

  11. Voluntarism and transparent deliberation

    DEFF Research Database (Denmark)

    Steglich-Petersen, Asbjørn

    2006-01-01

    It is widely assumed that doxastic deliberation is transparent to the factual question of the truth of the proposition being considered for belief, and that this sets doxastic deliberation apart from practical deliberation. This feature is frequently invoked in arguments against doxastic voluntar......It is widely assumed that doxastic deliberation is transparent to the factual question of the truth of the proposition being considered for belief, and that this sets doxastic deliberation apart from practical deliberation. This feature is frequently invoked in arguments against doxastic...

  12. Analyzing relation between the radioactivity in lanthanum products and the origins of RE chlorides

    International Nuclear Information System (INIS)

    Wan Rongsheng

    2004-01-01

    Objective: To analyze the relation between the radioactivity in Lanthanum products and the origins of RE Chlorides. Methods: Using JY-38 plus sequential ICP spectrometer to examine the content of the uranium in the RE Chlorides. Using FJ-2603 low background alpha, beta measurement apparatus to measure total alpha and total beta activities of Lanthanum products. Results: The content of the uranium in the RE Chlorides is much lower in Baotou's than Hunan's. The radioactivity in Lanthanum products are made from the RE Chlorides of Baotou is much lower than that in Hunan's too. The radioactivity in Lanthanum products depends on the origins of RE Chlorides. Conclusion: The basic data were provided for radioactivity in Lanthanum products which are made from RE Chlorides of different places of China. The mathematical model was founded for the reasonable use of resource RE Chlorides

  13. Conductivity in transparent oxide semiconductors.

    Science.gov (United States)

    King, P D C; Veal, T D

    2011-08-24

    Despite an extensive research effort for over 60 years, an understanding of the origins of conductivity in wide band gap transparent conducting oxide (TCO) semiconductors remains elusive. While TCOs have already found widespread use in device applications requiring a transparent contact, there are currently enormous efforts to (i) increase the conductivity of existing materials, (ii) identify suitable alternatives, and (iii) attempt to gain semiconductor-engineering levels of control over their carrier density, essential for the incorporation of TCOs into a new generation of multifunctional transparent electronic devices. These efforts, however, are dependent on a microscopic identification of the defects and impurities leading to the high unintentional carrier densities present in these materials. Here, we review recent developments towards such an understanding. While oxygen vacancies are commonly assumed to be the source of the conductivity, there is increasing evidence that this is not a sufficient mechanism to explain the total measured carrier concentrations. In fact, many studies suggest that oxygen vacancies are deep, rather than shallow, donors, and their abundance in as-grown material is also debated. We discuss other potential contributions to the conductivity in TCOs, including other native defects, their complexes, and in particular hydrogen impurities. Convincing theoretical and experimental evidence is presented for the donor nature of hydrogen across a range of TCO materials, and while its stability and the role of interstitial versus substitutional species are still somewhat open questions, it is one of the leading contenders for yielding unintentional conductivity in TCOs. We also review recent work indicating that the surfaces of TCOs can support very high carrier densities, opposite to the case for conventional semiconductors. In thin-film materials/devices and, in particular, nanostructures, the surface can have a large impact on the total

  14. Thermal expansion of doped lanthanum gallates

    Indian Academy of Sciences (India)

    Administrator

    Since the components are in intimate mechanical contact, any stress generated due to their thermal expansion mis- match during thermal cycling could lead to catastrophic failure of the cell. The functional materials must have similar thermal expansions to avoid mechanical stresses. Hence it is useful to study the thermal ...

  15. Fabrication of Sr- and Co-doped lanthanum chromite interconnectors for SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Setz, L.F.G. [Departamento de Engenharia de Materiais, Universidade Federal de Sao Carlos - DEMa/UFSCar (Brazil); Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN (Brazil); Santacruz, I. [Departamento de Quimica Inorganica, Cristalografia y Mineralogia, Universidad de Malaga, 29071 Malaga (Spain); Colomer, M.T., E-mail: tcolomer@icv.csic.es [Instituto de Ceramica y Vidrio, ICV (CSIC), 28049 Madrid (Spain); Mello-Castanho, S.R.H. [Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN (Brazil); Moreno, R. [Instituto de Ceramica y Vidrio, ICV (CSIC), 28049 Madrid (Spain)

    2011-07-15

    Graphical abstract: FESEM micrographs of the fresh fracture surfaces for the La{sub 0.80}Sr{sub 0.20}Cr{sub 0.92}Co{sub 0.08}O{sub 3} sintered specimens cast from optimised suspensions with 13.5, 15 and 17.5 vol.% solids loading. Aqueous suspensions were prepared using ammonium polyacrylate (PAA) as dispersant and tetramethylammonium hydroxide (TMAH) to assure a basic pH and providing stabilization. Sintering of the green discs was performed in air at 1600 {sup o}C for 4 h. Highlights: {yields} Optimum casting slips were achieved with 3 wt.% of ammonium polyacrylate and 1 wt.% of tetramethylammonium hydroxide. -- Abstract: Many studies have been performed dealing with the processing conditions of electrodes and electrolytes in solid oxide fuel cells (SOFCs). However, the processing of the interconnector material has received less attention. Lanthanum chromite (LaCrO{sub 3}) is probably the most studied material as SOFCs interconnector. This paper deals with the rheology and casting behaviour of lanthanum chromite based materials to produce interconnectors for SOFCs. A powder with the composition La{sub 0.80}Sr{sub 0.20}Cr{sub 0.92}Co{sub 0.08}O{sub 3} was obtained by combustion synthesis. Aqueous suspensions were prepared to solids loading ranging from 8 to 17.5 vol.%, using ammonium polyacrylate (PAA) as dispersant and tetramethylammonium hydroxide (TMAH) to assure a basic pH and providing stabilization. The influence of the additives concentrations and suspension ball milling time were studied. Suspensions prepared with 24 h ball milling, with 3 wt.% and 1 wt.% of PAA and TMAH, respectively, yielded the best conditions for successful slip casting. Sintering of the green discs was performed in air at 1600 {sup o}C for 4 h leading to relatively dense materials.

  16. Bio-accumulation of lanthanum from lanthanum modified bentonite treatments in lake restoration.

    Science.gov (United States)

    Waajen, G; van Oosterhout, F; Lürling, M

    2017-11-01

    Lanthanum (La) modified bentonite (LMB) is one of the available mitigating agents used for the reduction of the phosphorus (P) recycling in eutrophic lakes. The potential toxicity of the La from LMB to aquatic organisms is a matter of concern. In this study the accumulation of La was investigated in the macrophyte Elodea nuttallii, in chironomid larvae and in several fish species during periods up to five years following in situ LMB applications. The application of LMB increased the La concentration of exposed plants and animals. During the first growing season following LMB applications, the La content of E. nuttallii increased 78 fold (3.98-310.68 μg La g -1 DW) to 127 fold (2.46-311.44 μg La g -1 ). During the second growing season following application, the La content decreased but was still raised compared to plants that had not been exposed. The La content of chironomids was doubled in the two years following LMB application, although the increase was not significant. Raised La concentrations in fish liver, bone, muscle and skin were observed two and five years following to LMB application. Liver tissues showed the highest La increase, ranging from 6 fold (0.046-0.285 μg La g -1 DW) to ∼20 fold (0.080-1.886 μg La g -1 , and 0.122-2.109 μg La g -1 ) two years following application and from 6 fold (0.046-0.262 μg La g -1 ) to 13 fold (0.013-0.167 μg La g -1 ) after five years in pelagic and littoral fish. The La content of the liver from Anguilla anguilla (eel) had increased 94 fold (0.034-3.176 μg La g -1 ) two years and 133 fold (0.034-4.538 μg La g -1 ) five years following LMB application. No acute and chronic effects of La accumulation were observed and human health risks are considered negligible. We advocate the long-term study of effects of La accumulation following future LMB applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. The Causes of Fiscal Transparency

    DEFF Research Database (Denmark)

    Alt, James E.; Lassen, David Dreyer; Rose, Shanna

    We use unique panel data on the evolution of transparent budget procedures in the American states over the past three decades to explore the political and economic determinants of fiscal transparency. Our case studies and quantitative analysis suggest that both politics and fiscal policy outcomes...... influence the level of transparency. More equal political competition and power sharing are associated with both greater levels of fiscal transparency and increases in fiscal transparency during the sample period. Political polarization and past fiscal conditions, in particular state government debt...... and budget imbalance, also appear to affect the level of transparency...

  18. Transparency and imaginary colors

    NARCIS (Netherlands)

    Richards, W.; Koenderink, J.J.; Van Doorn, A.

    2009-01-01

    Unlike the Metelli monochrome transparencies, when overlays and their backgrounds have chromatic content, the inferred surface colors may not always be physically realizable, and are in some sense “imaginary.” In these cases, the inferred chromatic transmittance or reflectance of the overlay lies

  19. Complicating Methodological Transparency

    Science.gov (United States)

    Bridges-Rhoads, Sarah; Van Cleave, Jessica; Hughes, Hilary E.

    2016-01-01

    A historical indicator of the quality, validity, and rigor of qualitative research has been the documentation and disclosure of the behind-the-scenes work of the researcher. In this paper, we use what we call "methodological data" as a tool to complicate the possibility and desirability of such transparency. Specifically, we draw on our…

  20. Transparency for international trade

    Science.gov (United States)

    K. R. Lakin; G. A. Fowler; W. D. Bailey; J. Cavey; P. Lehtonen

    2003-01-01

    U.S. Department of Agriculture - Animal and Plant Health Inspection Service - Plant Protection and Quarantine (USDA-APHIS-PPQ) has developed a Regulated Plant Pest List (RPPL). This provides trading partners with an official list of plant pests of concern to the U.S., along with providing greater transparency of Agency actions.

  1. The Mediated Transparent Society

    DEFF Research Database (Denmark)

    Backer, Lise

    2001-01-01

    in the mediated transparent society. The paper concludes that, based on these analyses, the mediated panopticism working on the business segment is not an effective disciplinary apparatus, which can guarantee that business corporations are carrying out important ecological or ethical improvements....

  2. Remote Monitoring Transparency Program

    International Nuclear Information System (INIS)

    Sukhoruchkin, V.K.; Shmelev, V.M.; Roumiantsev, A.N.

    1996-01-01

    The objective of the Remote Monitoring Transparency Program is to evaluate and demonstrate the use of remote monitoring technologies to advance nonproliferation and transparency efforts that are currently being developed by Russia and the United States without compromising the national security to the participating parties. Under a lab-to-lab transparency contract between Sandia National Laboratories (SNL) and the Kurchatov Institute (KI RRC), the Kurchatov Institute will analyze technical and procedural aspects of the application of remote monitoring as a transparency measure to monitor inventories of direct- use HEU and plutonium (e.g., material recovered from dismantled nuclear weapons). A goal of this program is to assist a broad range of political and technical experts in learning more about remote monitoring technologies that could be used to implement nonproliferation, arms control, and other security and confidence building measures. Specifically, this program will: (1) begin integrating Russian technologies into remote monitoring systems; (2) develop remote monitoring procedures that will assist in the application of remote monitoring techniques to monitor inventories of HEU and Pu from dismantled nuclear weapons; and (3) conduct a workshop to review remote monitoring fundamentals, demonstrate an integrated US/Russian remote monitoring system, and discuss the impacts that remote monitoring will have on the national security of participating countries

  3. Adsorbtion of oxygen and cesium on lanthanum hexaboride

    International Nuclear Information System (INIS)

    Gorodetskij, D.A.; Tskhakaya, V.K.; Shchudlo, Yu.G.; Yarygin, V.I.; Yas'ko, A.A.

    1982-01-01

    Oxygen and cesium adsorption on lanthanum hexaboride was investigated. Especial attention was paid to structural investigations of the LaB 6 (100)-O system. Diffraction pictures and curves of changes in work function in the process of oxygen disorption have been obtained. At oxygen adsorption on a crystal heated up to different temperatures in the range of 900-1400 K the same diffraction pictures as at corresponding annealing temperatures observed were. It is noted that adsorption heat changes slightly in the LaB 6 -O-Cs system

  4. Lanthanum (samarium) nitrate-4-aminoantipyrine nitrate-water systems

    International Nuclear Information System (INIS)

    Starikova, L.I.; Zhuravlev, E.F.

    1985-01-01

    Using the isothermal method of cross-sections at 50 deg C systems lanthanum nitrate-4-aminoantipyrine nitrate-water (1), samarium nitrate-4-aminoantipyrine nitrate-water (2), are studied. Isotherms of system 1 consist of two crystallization branches of initial salt components. In system 2 formation of congruently soluble compounds of the composition Sm(No) 3 ) 3 xC 11 H 13 ON 3 xHNO 3 is established. Analytical, X-ray phase and thermogravimetric analysis of the isolated binary salt are carried out

  5. Catalytic activity of lanthanum oxide for the reduction of cyclohexanone

    International Nuclear Information System (INIS)

    Sugunan, S.; Sherly, K.B.

    1994-01-01

    Lanthanum oxides, La 2 O 3 has been found to be an effective catalyst for the liquid phase reduction of cyclohexanone. The catalytic activities of La 2 O 3 activated at 300, 500 and 800 degC and its mixed oxides with alumina for the reduction of cylcohexanone with 2-propanol have been determined and the data parallel that of the electron donating properties of the catalysts. The electron donating properties of the catalysts have been determined from the adsorption of electron acceptors of different electron affinities on the surface of these oxides. (author). 15 refs., 2 figs., 1 tab

  6. File: nuclear safety and transparency

    International Nuclear Information System (INIS)

    Martinez, J.P.; Etchegoyen, A.; Jeandron, C.

    2001-01-01

    Several experiences of nuclear safety and transparency are related in this file. Public information, access to documents, transparency in nuclear regulation are such subjects developed in this debate. (N.C.)

  7. Transparent Armor Cost Benefit Study

    National Research Council Canada - National Science Library

    Prokurat Franks, Lisa; Holm, David; Barnak, Rick

    2006-01-01

    ...; the increase in demand for transparent gun shields in Operation Iraqi Freedom (OIF) and early versions of jerry-rigged shields used in OIF, including Pope glass and Transparent Armored Gun Shields (TAGS...

  8. Responses in sediment phosphorus and lanthanum concentrations and composition across 10 lakes following applications of lanthanum modified bentonite

    DEFF Research Database (Denmark)

    Dithmer, Line; Nielsen, Ulla Gro; Lürling, Miquel

    2016-01-01

    and binding forms, P adsorption capacity of discrete sediment layers, and pore water P concentrations. Lanthanum phosphate mineral phases were confirmed by solid state (31)P MAS NMR and LIII EXAFS spectroscopy. Rhabdophane (LaPO4 · nH2O) was the major phase although indications of monazite (LaPO4) formation...... conditions of P retention (with the exception of two lakes) by sediments, indicating effective control of sediment P release, i.e. between two and nine years after treatment....

  9. Management of hyperphosphatemia in patients with end-stage renal disease: focus on lanthanum carbonate

    Directory of Open Access Journals (Sweden)

    Veerle P Persy

    2009-04-01

    Full Text Available Veerle P Persy, Geert J Behets, Marc E De Broe, Patrick C D’HaeseLaboratory of Pathophysiology, University of Antwerp, BelgiumAbstract: Elevated serum phosphate levels as a consequence of chronic kidney disease (CKD contribute to the increased cardiovascular risk observed in dialysis patients. Protein restriction and dialysis fail to adequately prevent hyperphosphatemia, and in general treatment with oral phosphate binding agents is necessary in patients with advanced CKD. Phosphate plays a pivotal role in the development of vascular calcification, one of the factors contributing to increased cardiovascular risk in CKD patients. Treatment of hyperphosphatemia with standard calcium-based phosphate binders and vitamin D compounds can induce hypercalcemic episodes, increase the Ca × PO4 product and thus add to the risk of ectopic mineralization. In this review, recent clinical as well as experimental data on lanthanum carbonate, a novel, non-calcium, non-resin phosphate binding agent are summarized. Although lanthanum is a metal cation no aluminium-like toxicity is observed since the bioavailability of lanthanum is extremely low and its metabolism differs from that of aluminium. Clinical studies now document the absence of toxic effects of lanthanum for up to 6 years of follow-up. The effects of lanthanum on bone, vasculature and brain are discussed and put in perspective with lanthanum pharmacokinetics.Keywords: lanthanum carbonate, phosphate binding, chronic kidney disease

  10. Separation of lanthanum from nuclear fuel solutions by high performance liquid chromatography

    International Nuclear Information System (INIS)

    Lazar, G. C.; Petre, M.; Androne, G.; Benga, A.

    2016-01-01

    This paper presents the separation of uranium, praseodymium and lanthanum from nuclear fuel solutions by high performance liquid chromatography (HPLC). The aim of this study is to establish a minimum concentration of lanthanum which can be analyzed by high performance liquid chromatography, and also to study the effect of uranium concentration on the separation of praseodymium and lanthanum. Optimum gradient mode was established for mixture standard stoc solutions with uranium in a concentration of 1 mg/ml, praseodymium and lanthanum in a concentration range of 1-5 μg/ml from each element. These conditions were applied for the separation of lanthanum from a nuclear fuel solution in which praseodymium and lanthanum were added in a concentration of 3 μg/ml from each element. The elution behavior of lanthanum as a function of the pH and the concentration of the mobile phase, using a mixture of 1-octanesulfonic acid sodium salt with a-hidroxyisobutiric acid is presented. (authors)

  11. The evolution mechanism of the dislocation loops in irradiated lanthanum doped cerium oxide

    International Nuclear Information System (INIS)

    Miao, Yinbin; Aidhy, Dilpuneet; Chen, Wei-Ying; Mo, Kun; Oaks, Aaron; Wolf, Dieter; Stubbins, James F.

    2014-01-01

    Cerium dioxide, a non-radioactive surrogate of uranium dioxide, is useful for simulating the radiation responses of uranium dioxide and mixed oxide fuel (MOX). Controlled additions of lanthanum can also be used to form various levels of lattice oxide or anion vacancies. In previous transmission electron microscopy (TEM) experimental studies, the growth rate of dislocation loops in irradiated lanthanum doped ceria was reported to vary with lanthanum concentration. This work reports findings of the evolution mechanisms of the dislocation loops in cerium oxide with and without lanthanum dopants based on a combination of molecular statics and molecular dynamics simulations. These dislocation loops are found to be b=1/3〈111〉 interstitial type Frank loops. Calculations of the defect energy profiles of the dislocation loops with different structural configurations and radii reveal the basis for preference of nucleation as well as the driving force of growth. Frenkel pair evolution simulations and displacement cascade overlaps simulations were conducted for a variety of lanthanum doping conditions. The nucleation and growth processes of the Frank loop were found to be controlled by the mobility of cation interstitials, which is significantly influenced by the lanthanum doping concentration. Competition mechanisms coupled with the mobility of cation point defects were discovered, and can be used to explain the lanthanum effects observed in experiments

  12. Evolution of the local environment of lanthanum during simplified SON68 glass leaching

    International Nuclear Information System (INIS)

    Jollivet, P.; Delaye, J.M.; Den Auwer, C.; Simoni, E.

    2007-01-01

    The evolution of the short- and medium-range local environment of lanthanum was determined by L-III-edge X-ray absorption spectroscopy (XAS) during leaching of simplified SON68-type glasses. In glass without phosphorus, lanthanum is found in a silicate environment, and its first coordination sphere comprises eight oxygen atoms at a mean distance of 2.51 angstrom. When this glass was leached at a high renewal rate, the lanthanum local environment was significantly modified: it was present at hydroxy-carbonate and silicate sites with a mean La-O distance of 2.56 angstrom, and the second neighbors consisted of La atoms instead of Si for the glass. Conversely, in the gel formed at low renewal rates, lanthanum was found in a silicate environment similar to that of the glass. In phosphorus-doped glass, lanthanum is found in a phosphate environment, although the Si/P atomic ratio is 20:1. Lanthanum is surrounded by seven oxygen atoms at a mean distance of 2.37 angstrom. When phosphorus-doped glass is leached, regardless of the leaching solution flow rate, the short- and medium-range lanthanum local environment remains almost constant; the most significant change is a 0.05 angstrom increase in the La-O distance. (authors)

  13. Certificate Transparency with Privacy

    Directory of Open Access Journals (Sweden)

    Eskandarian Saba

    2017-10-01

    Full Text Available Certificate transparency (CT is an elegant mechanism designed to detect when a certificate authority (CA has issued a certificate incorrectly. Many CAs now support CT and it is being actively deployed in browsers. However, a number of privacy-related challenges remain. In this paper we propose practical solutions to two issues. First, we develop a mechanism that enables web browsers to audit a CT log without violating user privacy. Second, we extend CT to support non-public subdomains.

  14. Pursuing transparency through science courts

    Energy Technology Data Exchange (ETDEWEB)

    Field, Thomas G. Jr. [Franklin Pierce Law Center, Concord, NH (United States)

    1999-12-01

    Many, disappointed with traditional ways to assess and manage health, safety and environmental risks, have sought alternatives that might better serve democratic values and truth. Arthur Kantrowitz proposed one in 1967. Named the 'Science Court' by the media, it sought to air opposing viewpoints publicly before an independent, neutral and technically competent panel of scientists. The idea has received considerable attention over the years, but some see it as too opaque and elitist. Ironically, others may view it as too transparent. Beyond that, as proposed it might have been too time-consuming and expensive, and few scientists would have welcomed a suggestion for cross-examination. Yet, its key features still offer promise for resolving difficult policy disputes and might be usefully integrated with notions since leading to the creation and endorsement of advisory science boards.

  15. Pursuing transparency through science courts

    International Nuclear Information System (INIS)

    Field, Thomas G. Jr.

    1999-01-01

    Many, disappointed with traditional ways to assess and manage health, safety and environmental risks, have sought alternatives that might better serve democratic values and truth. Arthur Kantrowitz proposed one in 1967. Named the 'Science Court' by the media, it sought to air opposing viewpoints publicly before an independent, neutral and technically competent panel of scientists. The idea has received considerable attention over the years, but some see it as too opaque and elitist. Ironically, others may view it as too transparent. Beyond that, as proposed it might have been too time-consuming and expensive, and few scientists would have welcomed a suggestion for cross-examination. Yet, its key features still offer promise for resolving difficult policy disputes and might be usefully integrated with notions since leading to the creation and endorsement of advisory science boards

  16. Pursuing transparency through science courts

    Energy Technology Data Exchange (ETDEWEB)

    Field, Jr, Thomas G [Franklin Pierce Law Center, Concord, NH (United States)

    1999-12-01

    Many, disappointed with traditional ways to assess and manage health, safety and environmental risks, have sought alternatives that might better serve democratic values and truth. Arthur Kantrowitz proposed one in 1967. Named the 'Science Court' by the media, it sought to air opposing viewpoints publicly before an independent, neutral and technically competent panel of scientists. The idea has received considerable attention over the years, but some see it as too opaque and elitist. Ironically, others may view it as too transparent. Beyond that, as proposed it might have been too time-consuming and expensive, and few scientists would have welcomed a suggestion for cross-examination. Yet, its key features still offer promise for resolving difficult policy disputes and might be usefully integrated with notions since leading to the creation and endorsement of advisory science boards.

  17. Lanthanum halide scintillators: Properties and applications

    International Nuclear Information System (INIS)

    Iltis, Alain; Mayhugh, M.R.; Menge, P.; Rozsa, C.M.; Selles, O.; Solovyev, V.

    2006-01-01

    BrilLanCe[reg]-350 and BrilLanCe[reg]-380, Saint-Gobain Crystals' trade-names for LaCl 3 :Ce and LaBr 3 :Ce are being brought to market under exclusive license to Delft and Bern Universities. We are reporting the properties of crystals produced with commercially viable processes and find they match others' observations. These scintillators are bright (60,000 photons/MeV for LaBr 3 :Ce) and have very linear response, a combination that leads to very good energy resolution ( 3 :Ce). The materials also have fast scintillation decay times ( 3 :Ce). These excellent properties are retained at high temperature with only moderate light loss ( 138 and Ac 227 , the latter having been substantially reduced in recent processing. BrilLanCe[reg]-350 is now available in detectors up to 51 mm diameter while 38 mm diameter is available for BrilLanCe[reg]-380. Larger sizes are expected

  18. Economy and Transparency: The Model Invention

    Directory of Open Access Journals (Sweden)

    Mahmud Hassan TALUKDAR

    2013-12-01

    Full Text Available Relation of Transparency and Economic growth is a long global debate in the society. Theoretically, policy makers, scholars and researchers argue that there is a close relation among these two variables. However, the quantitative relation and any global model is yet unrevealed. So, the main aim of this paper is to ascertain the nature, dimension and extent of the relationship between economy and Transparency as well as to invent a global model. This paper is useful for researchers, planners, policy makers and scholars who are directly or indirectly involved or willing to involve in the thrust for quantitative relation of these two variables. Literature review is the main source of information of this study. In introductory section, this paper briefly describes theoretical relationship of economy and Transparency as well as it also describes the proxy variables.GDP (2012 of different countries are used as proxy of Economy and Corruption Perception Index (CPI scores (2012 of different countries are used as proxy of level of Transparency. In methodology section this paper describes the detail methodology, sampling procedure and level of analysis. This study randomly selects 30 countries (10 from higher CPI scores+10 from moderate CPI scores+ 10 from lower CPI scores around the globe as sample. In the third section, this research presents the correlation value which divulge that there is a positive correlation (p=.047 with 95% confidence level. That reveals, if the level of transparency of any country increase, the GDP also increase accordingly. Then in this section two quantitative models are developed using linear regression analysis. First invented model is: Economy (GDP in billion US$ = [(8.983*Level of transparency -108.11]. This paper termed the first invented model as “Mahmud EcoT Model-1”. This model calibrates that one unit improvement of transparency leads 8.98 billion US$ improvement in the GDP of a country. Then taking this unit

  19. Transparent conducting oxide nanotubes

    Science.gov (United States)

    Alivov, Yahya; Singh, Vivek; Ding, Yuchen; Nagpal, Prashant

    2014-09-01

    Thin film or porous membranes made of hollow, transparent, conducting oxide (TCO) nanotubes, with high chemical stability, functionalized surfaces and large surface areas, can provide an excellent platform for a wide variety of nanostructured photovoltaic, photodetector, photoelectrochemical and photocatalytic devices. While large-bandgap oxide semiconductors offer transparency for incident light (below their nominal bandgap), their low carrier concentration and poor conductivity makes them unsuitable for charge conduction. Moreover, materials with high conductivity have nominally low bandgaps and hence poor light transmittance. Here, we demonstrate thin films and membranes made from TiO2 nanotubes heavily-doped with shallow Niobium (Nb) donors (up to 10%, without phase segregation), using a modified electrochemical anodization process, to fabricate transparent conducting hollow nanotubes. Temperature dependent current-voltage characteristics revealed that TiO2 TCO nanotubes, doped with 10% Nb, show metal-like behavior with resistivity decreasing from 6.5 × 10-4 Ωcm at T = 300 K (compared to 6.5 × 10-1 Ωcm for nominally undoped nanotubes) to 2.2 × 10-4 Ωcm at T = 20 K. Optical properties, studied by reflectance measurements, showed light transmittance up to 90%, within wavelength range 400 nm-1000 nm. Nb doping also improves the field emission properties of TCO nanotubes demonstrating an order of magnitude increase in field-emitter current, compared to undoped samples.

  20. Transparency -- Some observations

    International Nuclear Information System (INIS)

    Houck, F.

    1994-01-01

    The increasingly popular term transparency has been used throughout the IAEA Safeguards Symposium to mean many things to many people. It has rather little utility as a catch-all term or buzz word. A precise definition of transparency is in order. In this paper, transparency is the provision to the IAEA of additional information for which the IAEA has an identified use and includes any associated increased IAEA access to sue the information. In 1993, the IAEA Board endorsed very specific proposals for provision to the IAEA of additional information on international nuclear transfers. It also made specific decisions on verification in the context of tis earlier confirmation of the very sweeping access rights for special inspections outlined by the director general. Additional information to the IAEA has two potential practical uses. First, it could help identify inconsistencies within the entirety of the information available to the IAEA, including information from inspections. These inconsistencies could be an indication of some violation of safeguards undertakings. Second, a declaration of the Member State could facilitate IAEA interpretation of analyses of other information or facilitate resolution of ambiguities. In these respects, additional information is not different from currently used information. When considering seeking specific additional information, the IAEA must balance the potential contribution of the information and its expected costs

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  2. Lanthanum benzoyl acetonates: an IR and mass spectrometric study of the composition and structure

    International Nuclear Information System (INIS)

    Kostyuk, N.N.; Dik, T.A.; Tereshko, N.V.

    2005-01-01

    IR spectroscopy and mass spectrometry were used to study the structure of lanthanum chelates of benzoyl acetone (1-phenyl-1,3-butadione, HBA) of the following compositions: La(BA) 3 · EtOH, La(BA) 2 , La(BA) 2 · CH 3 CN, and La(BA) 2 · HDA, where EtOH = ethanol, HDA = nonadecanoic acid. It is demonstrated that a quasi-aromatic metalloring is formed in lanthanum chelates studied. Stable metal-containing fragments of the molecular ions of lanthanum bis- and tris-benzoylacetonate were identified [ru

  3. 76 FR 1180 - FDA Transparency Initiative: Improving Transparency to Regulated Industry

    Science.gov (United States)

    2011-01-07

    ...] FDA Transparency Initiative: Improving Transparency to Regulated Industry AGENCY: Food and Drug... the Transparency Initiative, the Food and Drug Administration (FDA) is announcing the availability of a report entitled ``FDA Transparency Initiative: Improving Transparency to Regulated Industry.'' The...

  4. Transparent platinum counter electrode for efficient semi-transparent dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Iefanova, Anastasiia; Nepal, Jeevan; Poudel, Prashant; Davoux, Daren; Gautam, Umesh [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States); Mallam, Venkataiah [Chemistry and Biochemistry Department, South Dakota State University, Brookings, SD 57006 (United States); Qiao, Qiquan [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States); Logue, Brian [Chemistry and Biochemistry Department, South Dakota State University, Brookings, SD 57006 (United States); Baroughi, Mahdi Farrokh, E-mail: m.farrokhbaroughi@sdstate.edu [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States)

    2014-07-01

    A method for fabrication of highly transparent platinum counter electrodes (CEs) has been developed based on spray coating of Pt nanoparticles (NPs) on hot substrates. This method leads to 86% reduction in Pt consumption reducing the Pt cost per peak watt of counter electrode from $0.79/Wp down to $0.11/Wp compared to the conventional Pt counter electrodes made by sputter deposition. The simplicity and low cost of this method provide a basis for an up-scalable fabrication process. The Pt NP layer is over 88% transparent, leading to overall transparency of 80% when incorporated with indium tin oxide/glass substrates for functional counter electrodes. This counter electrode exhibits a large surface area and high catalytic activity, comparable to that of the conventional opaque CEs. Semi-transparent dye-sensitized solar cells fabricated based on this counter electrode showed 6.17% power conversion efficiency. - Highlights: • Counter electrode (CE) prepared by spraying nanoparticle (NP) Pt on hot substrate. • Low cost and scalable fabrication process of CE. • The spray deposited CE uses 10 times less Pt compared to the sputtering method. • The CE is 80% transparent and exhibits a large surface and high catalytic activity. • A semitransparent dye-sensitized solar cell with Pt NP CE was 6.17% efficient.

  5. Pitfalls in looking for color transparency at intermediate energies

    International Nuclear Information System (INIS)

    Frankfurt, L.L.; Strikman, M.I.; Zhalov, M.B.

    1994-01-01

    The problems and uncertainties in the search for color transparency at intermediate Q 2 are considered. We show that conventional (optical) model [distorted wave impulse approximation (DWIA)] predicts a substantial change of the transparency, T, with Q 2 in the kinematics of the Ne-18 (e,e ' p) experiment, while the color transparency phenomenon may lead to nearly Q 2 independent T. In the case of A(p,2p) reaction we demonstrate that the conventional optical model describes well the 1 GeV A(p,2p) data but not the transparency observed at higher energies. We find also that DWIA (with or without color transparency) predicts strong dependence of T on the momentum of the struck nucleon which is consistent with the pattern of the Brookhaven National Laboratory A(p,2p) data at p N =6 GeV/c and 10 GeV/c

  6. Leaching behavior of lanthanum, nickel and iron from spent catalyst using inorganic acids

    Science.gov (United States)

    Astuti, W.; Prilitasari, N. M.; Iskandar, Y.; Bratakusuma, D.; Petrus, H. T. B. M.

    2018-01-01

    Highly technological applications of rare earth metals (REs) and scarcity of supply have become an incentive torecover the REs from various resources, which include high grade and low grade ores, as well as recycledwaste materials. Spent hydrocracking catalyst contain lanthanum and a variety of valuable metals such as nickel and iron. This study investigated the recovery of lanthanum, nickel and iron from spent hydrocracking catalyst by leaching using various inorganic acid (sulfuric acid, hydrochloric acid, and nitric acid). The effect of acid concentration, type of acid and leaching temperature was conducted to study the leaching behavior of each valuable metal from spent-catalyst. It has been shown that it is possible to recover more than 90% of lanthanum, however the leaching efficiency of nickel and iron in this process was very low. It can be concluded that the leaching process is selective for lanthanum recovery from hydrocracking spent-catalyst.

  7. Plasma spheroidization and high temperature stability of lanthanum phosphate and its compatibility with molten uranium

    Energy Technology Data Exchange (ETDEWEB)

    Ananthapadmanabhan, P.V. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)], E-mail: pvananth@barc.gov.in; Sreekumar, K.P.; Thiyagarajan, T.K.; Satpute, R.U. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Krishnan, K.; Kulkarni, N.K. [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kutty, T.R.G. [Radiometallurgy Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2009-01-15

    Lanthanum phosphate has excellent thermal stability and corrosion resistance against many molten metals and other chemically corrosive environments. Lanthanum phosphate (LaPO{sub 4}) was synthesized from lanthanum oxalate by thermal dissociation of the oxalate to the oxide, followed by conversion to hydrated lanthanum phosphate (LaPO{sub 4}.0.5H{sub 2}O). Thermal treatment of LaPO{sub 4}.0.5H{sub 2}O above 773 K resulted in the irreversible transformation of the hydrated phase to the stable monazite phase. Thermal and chemical stability of monazite was studied by plasma spheroidization experiments using a DC thermal plasma reactor set up. Compatibility of monazite with molten uranium was studied by thermal analysis. Results showed that monazite is thermally stable up to its melting point and also is resistant towards attack by molten uranium. Adherent coatings of LaPO{sub 4} could be deposited onto various substrates by atmospheric plasma spray technique.

  8. Studies on the lanthanum arsenate ion-exchanger: preparation, physicochemical properties and applications

    International Nuclear Information System (INIS)

    Mukherjee, A.K.; Mandal, S.K.

    1984-01-01

    The cation-exchange behaviour of lanthanum arsenate has been studied. This paper reports the preparation and physicochemical properties of the exchanger. Its analytical utility is compared with that of other arsenate exchangers. Some practical analytical applications are described. (author)

  9. Synthesis characterization and sintering of cobalt-doped lanthanum chromite powders for use in SOFCs

    International Nuclear Information System (INIS)

    Yamagata, Chieko; Mello-Castanho, Sonia R.H.

    2009-01-01

    Doped lanthanum chromite is a promising as interconnect material because of its good conductivity at high temperatures and its stability in oxidizing and reducing atmospheres. Perovskite oxide powders of Co-doped lanthanum chromite were synthesized by dispersing precursor metal salt solutions in a polymer matrix followed by a thermal treatment. XRD patterns showed that a highly crystalline cobalt-doped lanthanum chromite was obtained. Fine perovskite powder with a surface area of 6.15 m 2 g -1 calcined at 700 deg C for 1 h, were obtained. After the sample sintered at 1450 deg C for 3h, the powder reached high densities exceeding 97% of the theoretical density. The proposed here has proved to be a very promising technique for the synthesis of lanthanum chromite powders. (author)

  10. Plasma spheroidization and high temperature stability of lanthanum phosphate and its compatibility with molten uranium

    International Nuclear Information System (INIS)

    Ananthapadmanabhan, P.V.; Sreekumar, K.P.; Thiyagarajan, T.K.; Satpute, R.U.; Krishnan, K.; Kulkarni, N.K.; Kutty, T.R.G.

    2009-01-01

    Lanthanum phosphate has excellent thermal stability and corrosion resistance against many molten metals and other chemically corrosive environments. Lanthanum phosphate (LaPO 4 ) was synthesized from lanthanum oxalate by thermal dissociation of the oxalate to the oxide, followed by conversion to hydrated lanthanum phosphate (LaPO 4 .0.5H 2 O). Thermal treatment of LaPO 4 .0.5H 2 O above 773 K resulted in the irreversible transformation of the hydrated phase to the stable monazite phase. Thermal and chemical stability of monazite was studied by plasma spheroidization experiments using a DC thermal plasma reactor set up. Compatibility of monazite with molten uranium was studied by thermal analysis. Results showed that monazite is thermally stable up to its melting point and also is resistant towards attack by molten uranium. Adherent coatings of LaPO 4 could be deposited onto various substrates by atmospheric plasma spray technique

  11. Perceptual transparency from image deformation.

    Science.gov (United States)

    Kawabe, Takahiro; Maruya, Kazushi; Nishida, Shin'ya

    2015-08-18

    Human vision has a remarkable ability to perceive two layers at the same retinal locations, a transparent layer in front of a background surface. Critical image cues to perceptual transparency, studied extensively in the past, are changes in luminance or color that could be caused by light absorptions and reflections by the front layer, but such image changes may not be clearly visible when the front layer consists of a pure transparent material such as water. Our daily experiences with transparent materials of this kind suggest that an alternative potential cue of visual transparency is image deformations of a background pattern caused by light refraction. Although previous studies have indicated that these image deformations, at least static ones, play little role in perceptual transparency, here we show that dynamic image deformations of the background pattern, which could be produced by light refraction on a moving liquid's surface, can produce a vivid impression of a transparent liquid layer without the aid of any other visual cues as to the presence of a transparent layer. Furthermore, a transparent liquid layer perceptually emerges even from a randomly generated dynamic image deformation as long as it is similar to real liquid deformations in its spatiotemporal frequency profile. Our findings indicate that the brain can perceptually infer the presence of "invisible" transparent liquids by analyzing the spatiotemporal structure of dynamic image deformation, for which it uses a relatively simple computation that does not require high-level knowledge about the detailed physics of liquid deformation.

  12. Transparent ultraviolet photovoltaic cells.

    Science.gov (United States)

    Yang, Xun; Shan, Chong-Xin; Lu, Ying-Jie; Xie, Xiu-Hua; Li, Bing-Hui; Wang, Shuang-Peng; Jiang, Ming-Ming; Shen, De-Zhen

    2016-02-15

    Photovoltaic cells have been fabricated from p-GaN/MgO/n-ZnO structures. The photovoltaic cells are transparent to visible light and can transform ultraviolet irradiation into electrical signals. The efficiency of the photovoltaic cells is 0.025% under simulated AM 1.5 illumination conditions, while it can reach 0.46% under UV illumination. By connecting several such photovoltaic cells in a series, light-emitting devices can be lighting. The photovoltaic cells reported in this Letter may promise the applications in glass of buildings to prevent UV irradiation and produce power for household appliances in the future.

  13. Towards energy transparent factories

    CERN Document Server

    Posselt, Gerrit

    2016-01-01

    This monograph provides a methodological approach for establishing demand-oriented levels of energy transparency of factories. The author presents a systematic indication of energy drivers and cost factors, taking into account the interdependencies between facility and production domains. Particular attention is given to energy flow metering and monitoring. Readers will also be provided with an in-depth description of a planning tool which allows for systematically deriving suitable metering points in complex factory environments. The target audience primarily comprises researchers and experts in the field of factory planning, but the book may also be beneficial for graduate students.

  14. Illusionary Transparency? Oil Revenues, Information Disclosure, and Transparency

    OpenAIRE

    Ofori, Jerome Jeffison; Lujala, Päivi

    2015-01-01

    xperience shows that discovery of valuable natural resources can become a curse rather than a blessing, and transparency has been identified as key to better resource governance because it can limit opportunities for corruption and mismanagement. This article shows that information disclosure, in which many governments and donor institutions engage, does not automatically translate into transparency. Ghana has embedded transparency as one of its key principles in oil management. However, fiel...

  15. Hydrophilic block copolymer-directed growth of lanthanum hydroxide nano-particles

    Energy Technology Data Exchange (ETDEWEB)

    Bouyer, F.; Sanson, N.; Gerardin, C. [Laboratoire de Materiaux Catalytiques et Catalyse en Chimie Organique, UMR 5618 CNRS-ENSCM-UM1, FR 1878, Institut Gerhardt, 34 - Montpellier (France); Destarac, M. [Centre de Recherches Rhodia Aubervilliers, 93 - Aubervilliers (France)

    2006-03-15

    Stable hairy lanthanum hydroxide nano-particles were synthesized in water by performing hydrolysis and condensation reactions of lanthanum cations in the presence of double hydrophilic poly-acrylic acid-b-polyacrylamide block copolymers (PAA-b-PAM). In the first step, the addition of asymmetric PAA-b-PAM copolymers (M{sub w,PAA} {<=} M{sub w,PAM}) to lanthanum salt solutions, both at pH = 5.5, induces the formation of monodispersed micellar aggregates, which are predominantly isotropic. The core of the hybrid aggregates is constituted of a lanthanum polyacrylate complex whose formation is due to bidentate coordination bonding between La{sup 3+} and acrylate groups, as shown by ATR-FTIR experiments and pH measurements. The size of the micellar aggregates depends on the molecular weight of the copolymer but is independent of the copolymer to metal ratio in solution. In the second step, the hydrolysis of lanthanum ions is induced by addition of a strong base such as sodium hydroxide. Either flocculated suspensions or stable anisotropic or spherical nano-particles of lanthanum hydrolysis products were obtained depending on the metal complexation ratio [acrylate]/[La]. The variation of that parameter also enables the control of the size of the core-corona nano-particles obtained by lanthanum hydroxylation. The asymmetry degree of the copolymer was shown to influence both the size and the shape of the particles. Elongated particles with a high aspect ratio, up to 10, were obtained with very asymmetric copolymers (M{sub w,PAM}/M{sub w,PAA}{>=}10) while shorter rice grain-like particles were obtained with a less asymmetric copolymer. The asymmetry degree also influences the value of the critical metal complexation degree required to obtain stable colloidal suspensions of polymer-stabilized lanthanum hydroxide. (authors)

  16. Price Transparency in the Online Age.

    Science.gov (United States)

    Kaplan, Jonathan L; Mills, Parker H

    2016-05-01

    Plastic surgeons are sometimes hesitant to provide their pricing information online, due to several concerns. However, if implemented right, price transparency can be used as a lead generation tool that provides consumers with the pricing information they want and gives the physician the consumer's contact information for follow-up. This study took place during the author's first year in private practice in a new city. An interactive price transparency platform (ie, cost estimator) was integrated into his website, allowing consumers to submit a "wishlist" of procedures to check pricing on these procedures of interest. However, the consumer must submit their contact information to receive the desired breakdown of costs that are tailored based on the author's medical fees. During that first year, without any advertising expenditure, the author's website received 412 wishlists from 208 unique consumers. Consumers (17.8%) that submitted a wishlist came in for a consultation and 62% of those booked a procedure. The average value of a booked procedure was over US $4000 and cumulatively, all of the leads from this one lead source in that first year generated over US $92,000 in revenue. When compared with non-price-aware patients, price-aware patients were 41% more likely to book a procedure. Price transparency led to greater efficiency and reduced consultations that ended in "sticker shock." When prudently integrated into a medical practice, price transparency can be a great lead generation source for patients that are (1) paying out of pocket for medically necessary services due to a high-deductible health plan or (2) paying for services not typically covered by insurance, such as cosmetic services.

  17. Sintering and electrical properties of strontium-doped lanthanum manganite

    Energy Technology Data Exchange (ETDEWEB)

    Tarrago, Diego Pereira; Sousa, Vania Caldas de [Universidade Federal do Rio Grande do Sul (LABIOMAT/PPGEM/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia de Minas, Metalurgica e de Materiais. Lab. de Biomateriais], Email: dptarrago@gmail.com; Moreno Buriel, Berta; Chinarro Martini, Eva; Jurado Egea, Jose Ramon [Consejo Superior de Investigaciones Cientificas (ICV/CSIC), Madrid (Spain). Inst. de Ceramica y Vidrio; Malfatti, Celia de Fraga [Universidade Federal do Rio Grande do Sul (LAPEC/PPGEM/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia de Minas, Metalurgica e de Materiais. Lab. de Pesquisa em Corrosao

    2010-07-01

    Lanthanum strontium manganites (LSM) are potential materials for cathode applications in solid oxide fuel cells (SOFC) due to their good catalytic activity, chemical stability and compatibility with electrolyte materials in high temperatures. The sinterability of single phase La{sub 1-x}Sr{sub x}Mn{sub O3} (x=0.18) perovskite powders and the electrical properties of the resulting samples are analyzed in this study. Using a heating microscope, the powders were pressed and sintered at different pressures and temperatures, resulting in an open porosity of 33.36% when compacted at 125 MPa and sintered at 1200 degree C. Top and cross-section s canning electron microscopy (SEM) micrographs revealed interconnected pores in the sintered body and, hence, a suitable microstructure for the application. The activation energy for conductance was 0.04 eV and the tested LSM bulk started to exhibit adequate electrical properties at about 500 degree C. (author)

  18. Temperature dependence of magnetoresistance in lanthanum manganite ceramics

    International Nuclear Information System (INIS)

    Gubkin, M.K.; Zalesskii, A.V.; Perekalina, T.M.

    1996-01-01

    Magnetoresistivity in the La0.9Na0.1Mn0.9(V,Co)0.1O3 and LaMnO3+δ ceramics was studied. The temperature dependence of magnetoresistance in these specimens was found to differ qualitatively from that in the La0.9Na0.1MnO3 single crystal (the magnetoresistance value remains rather high throughout the measurement range below the Curie temperature), with the maximum values being about the same (20-40% in the field of 20 kOe). Previously published data on magnetization, high frequency magnetic susceptibility, and local fields at the 139La nuclei of the specimens with similar properties attest to their magnetic inhomogeneity. The computation of the conductivity of the nonuniformly ordered lanthanum manganite was performed according to the mean field theory. The calculation results allow one to interpret qualitatively various types of experimental temperature dependences of magnetoresistance

  19. Phosphate binding therapy in dialysis patients: focus on lanthanum carbonate

    Directory of Open Access Journals (Sweden)

    Ismail A Mohammed

    2008-11-01

    Full Text Available Ismail A Mohammed, Alastair J HutchisonManchester Institute of Nephrology and Transplantation, Manchester Royal Infirmary, Oxford Road, Manchester, UKAbstract: Hyperphosphatemia is an inevitable consequence of end stage chronic kidney disease and is present in the majority of dialysis patients. Recent observational data has associated hyperphosphatemia with increased cardiovascular mortality among dialysis patients. Dietary restriction of phosphate and current dialysis prescription practices are not enough to maintain serum phosphate levels within the recommended range so that the majority of dialysis patients require oral phosphate binders. Unfortunately, conventional phosphate binders are not reliably effective and are associated with a range of limitations and side effects. Aluminium-containing agents are highly efficient but no longer widely used because of well established and proven toxicity. Calcium based salts are inexpensive, effective and most widely used but there is now concern about their association with hypercalcemia and vascular calcification. Sevelamer hydrochloride is associated with fewer adverse effects, but a large pill burden and high cost are limiting factors to its wider use. In addition, the efficacy of sevelamer as a monotherapy in lowering phosphate to target levels in severe hyperphosphatemia remains debatable. Lanthanum carbonate is a promising new non-aluminium, calcium-free phosphate binder. Preclinical and clinical studies have demonstrated a good safety profile, and it appears well tolerated and effective in reducing phosphate levels in dialysis patients. Its identified adverse events are apparently mild to moderate in severity and mostly GI related. It appears to be effective as a monotherapy, with a reduced pill burden, but like sevelamer, it is significantly more expensive than calcium-based binders. Data on its safety profile over 6 years of treatment are now available.Keywords: hyperphosphatemia, lanthanum

  20. Lanthanum chromite colloidal processing; Processamento coloidal de cromito de lantanio

    Energy Technology Data Exchange (ETDEWEB)

    Setz, Luiz Fernando Grespan

    2009-07-01

    Lanthanum chromite (LaCrO{sub 3}) is currently the most studied material for applications such as solid oxide fuel cell inter connector (HTSOFC). The complexity of microstructures and geometries of HTSOFC devices, require a precise control of processing parameters to get the desired combination of properties and this, the use of techniques involving concentrated ceramic slips conformation are appropriate, therefore, is well controlled, assist in obtaining homogeneous parts, reproductive and complex geometries. Thus, studies involving the surface chemistry, the stability conditions and slips flow behaviour in the forming conditions, provide important elements for processes control in the inter connectors manufacture, where more applied settings have slots and channels for the gases passage. Thus, surface chemistry, stability and rheological behaviour of strontium and cobalt doped LaCrO{sub 3} (La{sub 0.80}Sr{sub 0.20}Cr{sub 0.92}Co{sub 0.08}O{sub 3}) slips prepared with ethanol and water, were studied. The doped lanthanum chromite was produced by combustion synthesis in the IPEN/SP labs. The influence of parameters: p H (water), dispersant concentration, homogenization times and conditions, solid concentration, different ratios binder:plasticizer in the stability and the flow behavior of ceramic suspensions prepared were evaluated. The La{sub 0.80}Sr{sub 0.20}Cr{sub 0.92}Co{sub 0.08}O{sub 3} products obtained by casting aqueous slips in a plaster mould, using alkaline p H and anionic polyelectrolyte and tapes obtained by using ethanol as a dispersant medium, after sintering at 1600 deg C/4h presented theoretical density > 94%, suitable for use as HTSOFC inter connector. (author)

  1. Synthesis of calcium doped lanthanum manganite by mechanosynthesis

    International Nuclear Information System (INIS)

    Bolarin, A.M.; Sanchez, F.; Palomares, S.; Aguilar, J.A.; Torres-Villasenor, G.

    2007-01-01

    Lanthanum manganite doped with calcium, Ca 1/3 La 2/3 MnO 3-δ , was prepared by a high-energy ball milling. The precursors used were Mn 2 O 3 , La 2 O 3 and CaO, mixed in the stoichiometric ratio to obtain this manganite. The mechano-chemical process was performed at room temperature in a SPEX 8000D mixer/mill, using hardened steel balls and stainless steel vials, in air atmosphere. X-ray diffraction was used to elucidate the phase transformation as a function of the milling time. The Rietveld refinement was used in order to characterize structurally the manganites. The morphology and particle size of powder compound obtained were characterized by scanning electron microscope. The particle size of this powder material was measured with zeta size analyzer, and selected area electron diffraction (SAED) from TEM was used to elucidate the crystalline structure of this powder compound. The results showed that it is possible to obtain calcium doped lanthanum manganite by mechano-synthesis, using a weight ratio of ball to powder of 12:1, after 3 h of milling. The evolution of the phase transformation during the milling time is reported. Increases in milling time produce exponential decrease in the particle size, up to 680 nm after 1 h of milling. After the milling process it is obtained a powder compound with an orthorhombic structure (S.G. Pbnm). A prolonged milling time (>9 h) produce an important reduction in the particle size but this is accompanied with a high iron contamination caused by metallic residues originated from vial and balls and also, after 9 h of milling time, it was found an important distortion in orthorhombic structure, obtaining two types of parameters

  2. The transparency trap.

    Science.gov (United States)

    Bernstein, Ethan

    2014-10-01

    To promote accountability, productivity, and shared learning, many organizations create open work environments and gather reams of data on how individuals spend their time. A few years ago, HBS professor Ethan Bernstein set out to find empirical evidence that such approaches improve organizational performance. What he discovered is that this kind of transparency often has an unintended consequence: It can leave employees feeling vulnerable and exposed. When that happens, they conceal any conduct that deviates from the norm so that they won't have to explain it. Unrehearsed, experimental behaviors sometimes stop altogether. But Bernstein also discovered organizations that had established zones of privacy within open environments by setting four types of boundaries: around teams, between feedback and evaluation, between decision rights and improvement rights, and around periods of experimentation. Moreover, across several studies, the companies that had done all this were the ones that consistently got the most creative, efficient, and thoughtful work from their employees. Bernstein's conclusion? By balancing transparency and privacy, organizations can capture the benefits of both, and encourage just the right amount of "positive deviance" needed to increase innovation and productivity.

  3. Lattice Transparency of Graphene.

    Science.gov (United States)

    Chae, Sieun; Jang, Seunghun; Choi, Won Jin; Kim, Youn Sang; Chang, Hyunju; Lee, Tae Il; Lee, Jeong-O

    2017-03-08

    Here, we demonstrated the transparency of graphene to the atomic arrangement of a substrate surface, i.e., the "lattice transparency" of graphene, by using hydrothermally grown ZnO nanorods as a model system. The growth behaviors of ZnO nanocrystals on graphene-coated and uncoated substrates with various crystal structures were investigated. The atomic arrangements of the nucleating ZnO nanocrystals exhibited a close match with those of the respective substrates despite the substrates being bound to the other side of the graphene. By using first-principles calculations based on density functional theory, we confirmed the energetic favorability of the nucleating phase following the atomic arrangement of the substrate even with the graphene layer present in between. In addition to transmitting information about the atomic lattice of the substrate, graphene also protected its surface. This dual role enabled the hydrothermal growth of ZnO nanorods on a Cu substrate, which otherwise dissolved in the reaction conditions when graphene was absent.

  4. Flexible transparent electrode

    Science.gov (United States)

    Demiryont, Hulya; Shannon, Kenneth C., III; Moorehead, David; Bratcher, Matthew

    2011-06-01

    This paper presents the properties of the EclipseTECTM transparent conductor. EclipseTECTM is a room temperature deposited nanostructured thin film coating system comprised of metal-oxide semiconductor elements. The system possesses metal-like conductivity and glass-like transparency in the visible region. These highly conductive TEC films exhibit high shielding efficiency (35dB at 1 to 100GHz). EclipseTECTM can be deposited on rigid or flexible substrates. For example, EclipseTECTM deposited on polyethylene terephthalate (PET) is extremely flexible that can be rolled around a 9mm diameter cylinder with little or no reduction in electrical conductivity and that can assume pre-extension states after an applied stress is relieved. The TEC is colorless and has been tailored to have high visible transmittance which matches the eye sensitivity curve and allows the viewing of true background colors through the coating. EclipseTECTM is flexible, durable and can be tailored at the interface for applications such as electron- or hole-injecting OLED electrodes as well as electrodes in flexible displays. Tunable work function and optical design flexibility also make EclipseTECTM well-suited as a candidate for grid electrode replacement in next-generation photovoltaic cells.

  5. Positron annihilation in transparent ceramics

    Science.gov (United States)

    Husband, P.; Bartošová, I.; Slugeň, V.; Selim, F. A.

    2016-01-01

    Transparent ceramics are emerging as excellent candidates for many photonic applications including laser, scintillation and illumination. However achieving perfect transparency is essential in these applications and requires high technology processing and complete understanding for the ceramic microstructure and its effect on the optical properties. Positron annihilation spectroscopy (PAS) is the perfect tool to study porosity and defects. It has been applied to investigate many ceramic structures; and transparent ceramics field may be greatly advanced by applying PAS. In this work positron lifetime (PLT) measurements were carried out in parallel with optical studies on yttrium aluminum garnet transparent ceramics in order to gain an understanding for their structure at the atomic level and its effect on the transparency and light scattering. The study confirmed that PAS can provide useful information on their microstructure and guide the technology of manufacturing and advancing transparent ceramics.

  6. Transparent Electrodes for Efficient Optoelectronics

    KAUST Repository

    Morales-Masis, Monica

    2017-03-30

    With the development of new generations of optoelectronic devices that combine high performance and novel functionalities (e.g., flexibility/bendability, adaptability, semi or full transparency), several classes of transparent electrodes have been developed in recent years. These range from optimized transparent conductive oxides (TCOs), which are historically the most commonly used transparent electrodes, to new electrodes made from nano- and 2D materials (e.g., metal nanowire networks and graphene), and to hybrid electrodes that integrate TCOs or dielectrics with nanowires, metal grids, or ultrathin metal films. Here, the most relevant transparent electrodes developed to date are introduced, their fundamental properties are described, and their materials are classified according to specific application requirements in high efficiency solar cells and flexible organic light-emitting diodes (OLEDs). This information serves as a guideline for selecting and developing appropriate transparent electrodes according to intended application requirements and functionality.

  7. Positron annihilation in transparent ceramics

    International Nuclear Information System (INIS)

    Husband, P; Selim, F A; Bartošová, I; Slugeň, V

    2016-01-01

    Transparent ceramics are emerging as excellent candidates for many photonic applications including laser, scintillation and illumination. However achieving perfect transparency is essential in these applications and requires high technology processing and complete understanding for the ceramic microstructure and its effect on the optical properties. Positron annihilation spectroscopy (PAS) is the perfect tool to study porosity and defects. It has been applied to investigate many ceramic structures; and transparent ceramics field may be greatly advanced by applying PAS. In this work positron lifetime (PLT) measurements were carried out in parallel with optical studies on yttrium aluminum garnet transparent ceramics in order to gain an understanding for their structure at the atomic level and its effect on the transparency and light scattering. The study confirmed that PAS can provide useful information on their microstructure and guide the technology of manufacturing and advancing transparent ceramics. (paper)

  8. Transparent Electrodes for Efficient Optoelectronics

    KAUST Repository

    Morales-Masis, Monica; De Wolf, Stefaan; Woods-Robinson, Rachel; Ager, Joel W.; Ballif, Christophe

    2017-01-01

    With the development of new generations of optoelectronic devices that combine high performance and novel functionalities (e.g., flexibility/bendability, adaptability, semi or full transparency), several classes of transparent electrodes have been developed in recent years. These range from optimized transparent conductive oxides (TCOs), which are historically the most commonly used transparent electrodes, to new electrodes made from nano- and 2D materials (e.g., metal nanowire networks and graphene), and to hybrid electrodes that integrate TCOs or dielectrics with nanowires, metal grids, or ultrathin metal films. Here, the most relevant transparent electrodes developed to date are introduced, their fundamental properties are described, and their materials are classified according to specific application requirements in high efficiency solar cells and flexible organic light-emitting diodes (OLEDs). This information serves as a guideline for selecting and developing appropriate transparent electrodes according to intended application requirements and functionality.

  9. Budget transparency in local governments

    OpenAIRE

    Giménez Perona, Paloma

    2014-01-01

    Treball Final de Grau en Finances i Comptabilitat. Codi: FC1049. Curs acadèmic 2013-2014 This work will study the socio-demographic determinants, political, budgetary and economic, that affect the transparency of local entities. To perform the study, we have chosen the transparency index data for the 110 largest municipalities of Spain, in 2012 has been chosen from the information offered by the website of the organization Transparency International Spain. The results indica...

  10. Spectrophotometric study of the complexation equilibria of lanthanum(III) with 1,4-bis(4'-methylanilino)anthraquinone and the determination of lanthanum(III)

    International Nuclear Information System (INIS)

    Idriss, K.A.-R; El-Shahawy, A.S.; Sedaira, H.; Harfoush, A.A.

    1985-01-01

    The complexation equilibria of lanthanum(III) with 1,4-bis(4'-methylanilino)anthraquinone (Quinizarin Green) were studied spectrophotometrically in 40% V/V dimethylformamide using graphical analysis of the absorbance curves. The reaction mechanism of lanthanum with the bisarylaminoanthraquinone dye within the pH range 6 to 9.25 was demonstrated. The thermodynamic stabilities and the molar absorptivities of the complexes formed were determined. The optimum conditions for the spectrophotometric determination of La(III) with this reagent were found. (author)

  11. Aircraft Lighting and Transparency Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Lighting and Transparencies with Night Combat Lab performs radiometric and photometric measurements of cockpit lighting and displays. Evaluates the day,...

  12. Transparent lithium-ion batteries

    KAUST Repository

    Yang, Y.

    2011-07-25

    Transparent devices have recently attracted substantial attention. Various applications have been demonstrated, including displays, touch screens, and solar cells; however, transparent batteries, a key component in fully integrated transparent devices, have not yet been reported. As battery electrode materials are not transparent and have to be thick enough to store energy, the traditional approach of using thin films for transparent devices is not suitable. Here we demonstrate a grid-structured electrode to solve this dilemma, which is fabricated by a microfluidics-assisted method. The feature dimension in the electrode is below the resolution limit of human eyes, and, thus, the electrode appears transparent. Moreover, by aligning multiple electrodes together, the amount of energy stored increases readily without sacrificing the transparency. This results in a battery with energy density of 10 Wh/L at a transparency of 60%. The device is also flexible, further broadening their potential applications. The transparent device configuration also allows in situ Raman study of fundamental electrochemical reactions in batteries.

  13. Transparent lithium-ion batteries

    Science.gov (United States)

    Yang, Yuan; Jeong, Sangmoo; Hu, Liangbing; Wu, Hui; Lee, Seok Woo; Cui, Yi

    2011-01-01

    Transparent devices have recently attracted substantial attention. Various applications have been demonstrated, including displays, touch screens, and solar cells; however, transparent batteries, a key component in fully integrated transparent devices, have not yet been reported. As battery electrode materials are not transparent and have to be thick enough to store energy, the traditional approach of using thin films for transparent devices is not suitable. Here we demonstrate a grid-structured electrode to solve this dilemma, which is fabricated by a microfluidics-assisted method. The feature dimension in the electrode is below the resolution limit of human eyes, and, thus, the electrode appears transparent. Moreover, by aligning multiple electrodes together, the amount of energy stored increases readily without sacrificing the transparency. This results in a battery with energy density of 10 Wh/L at a transparency of 60%. The device is also flexible, further broadening their potential applications. The transparent device configuration also allows in situ Raman study of fundamental electrochemical reactions in batteries. PMID:21788483

  14. Canadian perspectives in evaluating transparency

    International Nuclear Information System (INIS)

    Herwig, L.

    2007-01-01

    The Canadian Nuclear Safety Commission's mission is to regulate the use of nuclear energy and materials to protect the health, safety, and security of Canadians and the environment, as well as to respect Canada's international commitments on the peaceful use of nuclear energy. In 2001, the CNSC established a vision to be one of the best nuclear regulators in the world and established four strategic priorities of effectiveness, transparency, excellence in staff, and efficiency. While fulfilling a very comprehensive mandate, the CNSC operates with a. very clear vision of its clientele - the Canadian people. That commitment guides every employee and every action of the CNSC and ensures a firm commitment to transparency. The presentation will begin with a brief overview of the worldwide context of transparency and transparency measurement, with a look at what lessons can be learned from other organizations and initiatives. It will look broadly at the Canadian context and the government framework that establishes transparency, including the keystone legislation of the Access to Information Act. The presentation will then focus on the Canadian Nuclear Safety Commission. The CNSC is firmly committed to putting additional measures in place to ensure transparency, which is being done concurrently with an overall organisational performance measurement system. It is within this framework that the presentation will address the transparency efforts at the CNSC as well transparency measurement activities. And, finally, the presentation will look at future directions for transparency and its measurement at the CNSC. (author)

  15. Separation of lanthanum (3) and samarium (3) extraction with tributylphosphate in the solvent presence of solid phase

    International Nuclear Information System (INIS)

    Korotkevich, I.B.; Kolesnikov, A.A.; Bomshtejn, V.E.

    1990-01-01

    Lanthanum (3) and samarium (3) extraction from nitric acid solutions by tributylphosphate in the presence of solid phase has been investigated. An increase in samarium α-nitrate distribution factor in the presence of solid phase with a decrease in its concentration in the initial solution and with lanthanum nitrate concentration increase is detected. The greatest effect of separation is observed in samarium nitrate microregion. The method of quantitative extraction of samarium from lanthanum nitrate solutions with samarium-lanthanum separation factor exceeding 50 has been suggested

  16. Separation of lanthanum (3) and neodymium (3) by tributyl phosphate extraction in the presence of solid phase

    International Nuclear Information System (INIS)

    Korotkevich, I.B.; Kolesnikov, A.A.; Bomshtejn, V.E.; Shikhaleeva, N.N.

    1987-01-01

    Lanthanum (3) and neodymium (3) extraction from nitric acid solutions by tributyl phosphate in the presence of solid phase of the element nitrates is investigated. An increase in distribution of neodymium nitrate in the presence of solid phase with the decrease in its concentration in the initial solution and with the increase in lanthanum nitrate concentration is detected. The highest effect of extractive-crystallizational separation is observed in the range of neodymium nitrate microconcentrations. A method of neodymium quantitative extraction from lanthanum nitrate solutions with neodymium - lanthanum separation coefficient exceeding 25 is suggested

  17. Investigation of thermal transformation of lanthanum and neodymium hydroxides by IK-spectroscopy

    International Nuclear Information System (INIS)

    Filippova, A.A.; Davydov, A.A.; Shchekochikhin, Yu.M.

    1976-01-01

    The spectral polymorphic transformations of lanthanum and neodymium oxides at the thermal decomposition of the hydroxides and carbonates of these elements are studied. The thermal decomposition was observed during 3-5 hours. The i.r. spectra of the decomposition products were measured for temperatures of 100-1000 0 C. The i.r. spectra of C-Nd 2 O 3 , of A-Nd 2 O 3 , of C-La 2 O 3 and of A-La 2 O 3 were obtained in the range of 250-4000cm -1 . The spectral consequences of the C→A-Nd 2 O 3 polymorphic transformation were also studied for the decomposition of the neodymium carbonate. The spectra of the calcination products of the hydroxides (400-700 0 C) are similar to characteristic spectra of cubic rare earth oxides in the spectral range of 250-700cm -1 . An increase of the calcination temperature (800-1000 0 C) leads to changes in the oxide spectrum. New maxima appear at 260, 360 and 450cm -1 . The absorption bands characteristic for cubic oxide lattices disappear. From spectral data it can be concluded that neodymium carbonate begins to decompose at 450 0 C if it is heated in vacuum. The decomposition products are oxycarbonate and oxide. The maximum at 520cm -1 confirms the crystallization of the oxide in the cubic C-form. At 800 0 C the polymorphic transformation C→A-Nd 2 O 3 sets in. In the oxide spectra traces of the carbonate can still be detected up to the polymorphic transformation temperature. From a comparison of X-ray and spectral data it is followed that the i.r. spectra of the decomposition product of the lanthanum hydroxide at 500 0 C are essentially the spectra of C-La 2 O 3 which are characterized by the absorption bands at 320, 340, 380 and 495cm -1 . The absorption band of A-La 2 O 3 , which is present in the sample, is not observed. I.r. spectra of C-La 2 O 3 are very similar to the spectra of the cubic form of rare earth oxides in the range of 250-600cm -1 . Changes in the spectrum at 600 0 C can be explained by the polymorphic transformation

  18. Transparency through the Internet

    Energy Technology Data Exchange (ETDEWEB)

    Haginoya, Tohru [Inst. of Nuclear Materials Management, Japan Chapter, Tokyo (Japan)

    1998-07-01

    Many countries, especially developed countries have their 'Home Pages' and disclose their activities openly including nuclear activities. These information give, to some extent, the transparency of countries. The annual report of the IAEA can be found in its home page, reports describe its safeguards activities including facilities under its safeguards together with the status of 'subsidiary arrangements'. The Atomic Energy White Papers of the STA home pages show its nuclear activities and nuclear material. Details of safeguards related information are obtained by analyzing these home pages and find some information inconsistent each other. In connection with Strengthened Safeguards system' , non-nuclear items such as zirconium, heavy water or their manufacturing organizations which are subject to the safeguards system would be retrieved by using 'search engines' through the internet. (author)

  19. Transparency through the Internet

    International Nuclear Information System (INIS)

    Haginoya, Tohru

    1998-01-01

    Many countries, especially developed countries have their 'Home Pages' and disclose their activities openly including nuclear activities. These information give, to some extent, the transparency of countries. The annual report of the IAEA can be found in its home page, reports describe its safeguards activities including facilities under its safeguards together with the status of 'subsidiary arrangements'. The Atomic Energy White Papers of the STA home pages show its nuclear activities and nuclear material. Details of safeguards related information are obtained by analyzing these home pages and find some information inconsistent each other. In connection with Strengthened Safeguards system' , non-nuclear items such as zirconium, heavy water or their manufacturing organizations which are subject to the safeguards system would be retrieved by using 'search engines' through the internet. (author)

  20. Transparency and control

    International Nuclear Information System (INIS)

    2001-01-01

    After having outlined some lessons learnt after the Chernobyl accident, notably the facts that risk assessment and management were not separated, that radioactivity measurements have suffered from a lack of means and of preparedness, and that there has been few information exchanged between the different concerned countries, this document presents the four international conventions which have been negotiated after this accident (they concern the notification, assistance, safety, safety of fuel management and of radioactive wastes). It discusses the lessons learnt in France, the credibility of information and the confidence in authorities, the evolution of transparency and information in France and in the rest of the World, the transposition of the Arhus Convention in the communautary and national law, the innovating European approaches, and the evolutions in France

  1. Acoustic transparency and opacity using Fano Interferences in Metamaterials

    KAUST Repository

    Khelif, A.

    2015-08-04

    We investigate both experimentally and theoretically how to generate the acoustical analogue of the Electromagnetically Induced Transparency. This phenomenon arises from Fano resonances originating from constructive and destructive interferences of a narrow discrete resonance with a broad spectral line or continuum. Measurements were realized on a double-cavity structure by using a Kundt’s Tube. Transmission properties reveal an asymmetric lineshape of the transmission that leads to acoustic transparency.

  2. Inhibition mechanism of lanthanum ion on the activity of horseradish peroxidase in vitro

    Science.gov (United States)

    Guo, Shaofen; Wang, Lihong; Lu, Aihua; Lu, Tianhong; Ding, Xiaolan; Huang, Xiaohua

    2010-02-01

    In order to understand the inhibition mechanism of lanthanum ion (La 3+) on the activity of horseradish peroxidase (HRP), the effects of La 3+ on the activity, electron transfer and conformation of HRP in vitro were investigated by using cyclic voltammetry (CV), atomic force microscopy (AFM), circular dichroism (CD), high performance liquid chromatography (HPLC), matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF/MS) and inductively coupled plasma mass spectrometry (ICP-MS). It was found that La 3+ can combine with the amide groups of the polypeptide chain in HRP molecule, forming the complex of La 3+ and HRP (La-HRP). The formation of the La-HRP complex causes the destruction of the native structure of HRP molecule, leading to the decrease in the non-planarity of the porphyrin ring in the heme group of HRP molecule, and then in the exposure extent of active center, Fe(III) of the porphyrin ring of HRP molecule. Thus, the direct electrochemical and catalytic activities of HRP are decreased. It is a possible inhibition mechanism of La 3+ on the activity of peroxidase.

  3. Suppression of cavitation in melted tungsten by doping with lanthanum oxide

    International Nuclear Information System (INIS)

    Yuan, Y.; Lu, G.H.; Xu, B.; Fu, B.Q.; Xu, H.Y.; Li, C.; Jia, Y.Z.; Qu, S.L.; Liu, W.; Greuner, H.; Böswirth, B.; Luo, G.-N.

    2014-01-01

    Melting and boiling behaviour of pure tungsten and 1 wt% lanthanum-oxide-doped tungsten (WL10) are investigated, focusing on the material selection with respect to material loss induced by cavitation. Melting experiments under high heat loads are carried out in the high heat flux facility GLADIS. Pulsed hydrogen neutral beams with heat flux of 10 and 23 MW m −2 are applied onto the adiabatically loaded samples for intense surface melting. Melt layer of the two tungsten grades exhibit different microstructure characteristics. Substantive voids owing to cavitation in the liquid phase are observed in pure W and lead to porous resolidified material. However, little cavitation bubbles can be found in the dense resolidified layer of WL10. In order to find out the gaseous sources, vapour collection is performed and the components are subsequently detected. Based on the observations and analyses, the microstructure evolutions corresponding to melting and vapourization behaviour of the two tungsten grades are tentatively described, and furthermore, the underlying mechanisms of cavitation in pure W and its suppression in WL10 are discussed. (paper)

  4. TRANSPARENT COATINGS FOR SOLAR CELLS RESEARCH

    Energy Technology Data Exchange (ETDEWEB)

    Glatkowski, P. J.; Landis, D. A.

    2013-04-16

    Todays solar cells are fabricated using metal oxide based transparent conductive coatings (TCC) or metal wires with optoelectronic performance exceeding that currently possible with Carbon Nanotube (CNT) based TCCs. The motivation for replacing current TCC is their inherent brittleness, high deposition cost, and high deposition temperatures; leading to reduced performance on thin substrates. With improved processing, application and characterization techniques Nanofiber and/or CNT based TCCs can overcome these shortcomings while offering the ability to be applied in atmospheric conditions using low cost coating processes At todays level of development, CNT based TCC are nearing commercial use in touch screens, some types of information displays (i.e. electronic paper), and certain military applications. However, the resistivity and transparency requirements for use in current commercial solar cells are more stringent than in many of these applications. Therefore, significant research on fundamental nanotube composition, dispersion and deposition are required to reach the required performance commanded by photovoltaic devices. The objective of this project was to research and develop transparent conductive coatings based on novel nanomaterial composite coatings, which comprise nanotubes, nanofibers, and other nanostructured materials along with binder materials. One objective was to show that these new nanomaterials perform at an electrical resistivity and optical transparency suitable for use in solar cells and other energy-related applications. A second objective was to generate new structures and chemistries with improved resistivity and transparency performance. The materials also included the binders and surface treatments that facilitate the utility of the electrically conductive portion of these composites in solar photovoltaic devices. Performance enhancement venues included: CNT purification and metallic tube separation techniques, chemical doping, CNT

  5. TRANSPARENCY IN ELECTRONIC BUSINESS NEGOTIATIONS – EVIDENCE BASED ANALYSIS

    Directory of Open Access Journals (Sweden)

    Radoslav Delina

    2014-12-01

    Full Text Available Purpose: In current economy, where ICT plays a crucial role for being competitive and effective, businesses are facing higher pressures of flexibility and efficiency than ever before. Transparency is often considered as a suitable mechanism for better market prices and more efficient market environment. Electronic business environment provides the possibility to set up more transparent environment and bring higher competitiveness and efficiency on the market. The paper analyse the impact of transparency on prices in e-procurement.Methodology: Reverse auctions are considered as transparent tool simulating in partial level real competition. Together, it allows to examine several levels of transparency set up in auction negotiation process. The impact of transparency on final prices was analysed on real data using relation based analysis were different situations of transparency set up is compared against achieved final price.Findings: Research results based on real data shows, that generally, the transparency in electronic reverse auction can lead to more negative prices agreed by purchasers as current scientific and commercial promotions.Research limitation: Significance of research results is limited due to still low readiness and skills of e-procurers. The validation of results is needed to realized within longer period of time and from environments with different level of e-readiness. Together, it reveal that transparency is more complex issue where the significance of transparency can reveal its sense in some specific situations on the market and negotiation.Value of paper: Evidenced based research reveal some controversy results which support new scientific efforts in microeconomics and socio-economic impact of ICT fields. Together, it affects real practitioners in way how to use and perceive claimed impact of reverse auction solutions.

  6. Nanocellulose reinforcement of Transparent Composites

    Science.gov (United States)

    Joshua Steele; Hong Dong; James F. Snyder; Josh A. Orlicki; Richard S. Reiner; Alan W. Rudie

    2012-01-01

    In this work, we evaluate the impact of nanocellulose reinforcement on transparent composite properties. Due to the small diameter, high modulus, and high strength of cellulose nanocrystals, transparent composites that utilize these materials should show improvement in bulk mechanical performances without a corresponding reduction in optical properties. In this study...

  7. Student Perceptions of Teaching Transparency

    Science.gov (United States)

    Anderson, Alecia D.; Hunt, Andrea N.; Powell, Rachel E.; Dollar, Cindy Brooks

    2013-01-01

    The authors discuss the relationship between teaching transparency and active learning through the perspectives of their students. Active learning directly engages students in the learning process while transparency involves the instructor's divulgence of logic regarding course organization and activity choices. After utilizing these teaching…

  8. Transparency as an ethical safeguard

    NARCIS (Netherlands)

    Spagnolli, Anna; Frank, Lily E.; Haselager, Pim; Kirsh, David; Ham, Jaap; Spagnolli, Anna; Blankertz, Benjamin; Gamberini, Luciano; Jacucci, Giulio

    2018-01-01

    Transparency seems to represent a solution to many ethic issues generated by systems that collect implicit data from users to model the user themselves based on programmed criteria. However, making such systems transparent -- besides being a major technical challenge - risks raising more issues than

  9. Electrical conductivity studies of nanocrystalline lanthanum silicate synthesized by sol-gel route

    International Nuclear Information System (INIS)

    Nallamuthu, N.; Prakash, I.; Satyanarayana, N.; Venkateswarlu, M.

    2011-01-01

    Research highlights: → Nanocrystalline La 10 Si 6 O 27 material was synthesized by sol-gel method. → TG/DTA curves predicted the thermal behavior of the material. → FTIR spectra confirmed the formation of SiO 4 and La-O network in the La 10 Si 6 O 27 . → XRD patterns confirmed the formation of pure crystalline La 10 Si 6 O 27 phase. → The grain interior and the grain boundary conductivities are evaluated. - Abstract: Nanocrystalline apatite type structured lanthanum silicate (La 10 Si 6 O 27 ) sample was synthesized by sol-gel process. Thermal behavior of the dried gel of lanthanum silicate sample was studied using TG/DTA. The structural coordination of the dried gel of lanthanum silicate, calcined at various temperatures, was identified from the observed FTIR spectral results. The observed XRD patterns of the calcined dried gel were compared with the ICDD data and confirmed the formation of crystalline lanthanum silicate phase. The average crystalline size of La 10 Si 6 O 27 was calculated using the Scherrer formula and it is found to be ∼80 nm. The observed SEM images of the lanthanum silicate indicate the formation of the spherical particles and the existence of O, Si and La in the lanthanum silicate are confirmed from the SEM-EDX spectrum. The grain and grain boundary conductivities are evaluated by analyzing the measured impedance data, using winfit software, obtained at different temperatures, of La 10 Si 6 O 27 sample. Also, the observed grain and grain boundary conductivity behaviors of the La 10 Si 6 O 27 sample are analysed using brick layer model. The electrical permittivity and electrical modulus were calculated from the measured impedance data and were analyzed by fitting through the Havriliak and Negami function to describe the dielectric relaxation behavior of the nanocrystalline lanthanum silicate.

  10. Robot transparency, trust and utility

    Science.gov (United States)

    Wortham, Robert H.; Theodorou, Andreas

    2017-07-01

    As robot reasoning becomes more complex, debugging becomes increasingly hard based solely on observable behaviour, even for robot designers and technical specialists. Similarly, non-specialist users have difficulty creating useful mental models of robot reasoning from observations of robot behaviour. The EPSRC Principles of Robotics mandate that our artefacts should be transparent, but what does this mean in practice, and how does transparency affect both trust and utility? We investigate this relationship in the literature and find it to be complex, particularly in nonindustrial environments where, depending on the application and purpose of the robot, transparency may have a wider range of effects on trust and utility. We outline our programme of research to support our assertion that it is nevertheless possible to create transparent agents that are emotionally engaging despite having a transparent machine nature.

  11. Phenomenal transparency in achromatic checkerboards.

    Science.gov (United States)

    Masin, S C

    1999-04-01

    The study explored the luminance relations that determine the occurrence of achromatic transparency in phenomenal surfaces on complex backgrounds. Let the luminances of the left and right parts of a transparent surface on a bipartite background and those of the left and right parts of the bipartite background be p and q and m and n, respectively. Metelli proposed that this surface looks transparent when the rule p q if m > n) is satisfied, and Masin and Fukuda that it looks transparent when the inclusion rule is satisfied, that is, when p epsilon (m, q) or q epsilon (p, n). These rules also apply to achromatic checkerboards formed by one checkerboard enclosed in another checkerboard. This study shows that only the inclusion rule correctly predicted the occurrence of transparency in these checkerboards.

  12. Lake responses following lanthanum-modified bentonite clay (Phoslock) application: an analysis of water column lanthanum data from 16 case study lakes

    NARCIS (Netherlands)

    Spears, B.M.; Lürling, M.F.L.L.W.; Yasseri, S.; Castro-Castellon, A.T.; Gibbs, M.; Meis, S.; McDonald, C.; McIntosh, J.; Sleep, D.; Oosterhout, van F.

    2013-01-01

    Phoslock is a lanthanum (La) modified bentonite clay that is being increasingly used as a geo-engineering tool for the control of legacy phosphorus (P) release from lake bed sediments to overlying waters. This study investigates the potential for negative ecological impacts from elevated La

  13. Synthesis of Ni nanoparticles in lanthanum chromite ceramic matrix

    International Nuclear Information System (INIS)

    Tinti, Victor Buratto; Florio, Daniel Zanetti de; Fonseca, Fabio Coral

    2016-01-01

    Full text: Lanthanum chromite is a well-known interconnector for solid oxide fuel cells. It presents electronic conductivity at high temperatures. Moreover it is very stable in oxidizing and reducing atmospheres. Due to its high stability this material is a promising matrix to produce and stabilize nanoparticles by exothermal reaction. The objective of the present work is to synthesize and stabilize nickel nanoparticles in a stable ceramic matrix. Compounds of (La 1-x Sr x ) a (Cr 1-y Ni y )O 3 (x and y = 0, 0.1, and 0.2; a = 1, and 0.8) were synthesized by Pechini method. The powders were heat treated in air at 1300 °C and 1600°C in attempt to solubilise NiO in the matrix. Then the samples were exposed to a reducing treatment in H 2(g) flux at 900°C per 8 hours. XRD measurements were made using a D8 Focus, Bruker AXS. The data was acquired in a range of 2θ from 20° to 90°, with a step of 0,02° per second. Magnetic properties were investigated utilizing a SQUIDVSM from Quantum Design. Magnetic moment at constant magnetic field (100 Oe and 1000 Oe) was measured in a range of 2K to 300K. Analyses with variable magnetic field were performed at 2K, 196K and 390K in a rage from -5 up to 5 T. Samples were observed using TEM technique. The XRD results showed that the stoichiometric samples achieved desiderate phase. Compounds without Sr and non-stoichiometric lanthanum site showed an incomplete nickel solid solution. The addition of 10% of Sr decreases the Neel temperature from 289 K to 285K. Ni doping created a stronger effect, lowering the temperature down to 267 K , in the sample with 10% of dopant. After reduction is possible to observe peaks of Ni in the XRD, indicating that nickel was exoluted form the matrix. Images of TEM confirm the presence of nanoparticles with an approximate diameter of 3 nm. The reducing treatment increased the magnetic response. (author)

  14. Potentiometric measurement of polymer-membrane electrodes based on lanthanum

    Energy Technology Data Exchange (ETDEWEB)

    Saefurohman, Asep, E-mail: saefurohman.asep78@Gmail.com; Buchari,, E-mail: saefurohman.asep78@Gmail.com; Noviandri, Indra, E-mail: saefurohman.asep78@Gmail.com [Department of Chemistry, Bandung Institute of Technology (Indonesia); Syoni [Department of Metallurgy Engineering, Bandung Institute of Technology (Indonesia)

    2014-03-24

    Quantitative analysis of rare earth elements which are considered as the standard method that has a high accuracy, and detection limits achieved by the order of ppm is inductively coupled plasma atomic emission spectroscopy (ICPAES). But these tools are expensive and valuable analysis of the high cost of implementation. In this study be made and characterized selective electrode for the determination of rare earth ions is potentiometric. Membrane manufacturing techniques studied is based on immersion (liquid impregnated membrane) in PTFE 0.5 pore size. As ionophores to be used tri butyl phosphate (TBP) and bis(2-etylhexyl) hydrogen phosphate. There is no report previously that TBP used as ionophore in polymeric membrane based lanthanum. Some parameters that affect the performance of membrane electrode such as membrane composition, membrane thickness, and types of membrane materials studied in this research. Manufacturing of Ion Selective Electrodes (ISE) Lanthanum (La) by means of impregnation La membrane in TBP in kerosene solution has been done and showed performance for ISE-La. FTIR spectrum results for PTFE 0.5 pore size which impregnated in TBP and PTFE blank showed difference of spectra in the top 1257 cm{sup −1}, 1031 cm{sup −1} and 794.7 cm{sup −1} for P=O stretching and stretching POC from group −OP =O. The result showed shift wave number for P =O stretching of the cluster (−OP=O) in PTFE-TBP mixture that is at the peak of 1230 cm{sup −1} indicated that no interaction bond between hydroxyl group of molecules with molecular clusters fosforil of TBP or R{sub 3}P = O. The membrane had stable responses in pH range between 1 and 9. Good responses were obtained using 10{sup −3} M La(III) internal solution, which produced relatively high potential. ISE-La showed relatively good performances. The electrode had a response time of 29±4.5 second and could be use for 50 days. The linear range was between 10{sup −5} and 10{sup −1} M.

  15. The preparation and composition design of boron-rich lanthanum hexaboride target for sputtering

    International Nuclear Information System (INIS)

    Chen, Defang; Min, Guanghui; Wu, Yan; Yu, Huashun; Zhang, Lin

    2015-01-01

    Highlights: • High-purity LaB 6 powder was prepared due to significant reduction of residual B 4 C and effective purification process. • The effects of raw materials ratio on the size, morphology, phase structure and crystalline size of LaB 6 were studied. • The correlation of component between LaB 6 films and boron-rich targets was established. • The variation of densities of LaB 6 targets with sintering time and sintering temperature was investigated. - Abstract: Lanthanum Hexaboride (LaB 6 ) nano-film has been proved to be promising transparent thermal insulation material, while its properties are limited on purity and composition. High-purity LaB 6 polycrystalline powder was prepared through boron carbide reduction method in this work. A series of techniques such as scanning electron microscopy, X-ray diffraction, laser particle analyzer and inductively coupled plasma emission spectrometer were employed to characterize LaB 6 powder. As raising the content of La 2 O 3 in reactants, more uniform, finer (2.686 μm) and purer (99.5139 wt%) LaB 6 powder is prepared, with only 0.4434 wt% residual B 4 C. The density of targets increases with the rise of sintering temperature and the extension of sintering time, while crystallite size increases simultaneously with the extension of sintering time. The introduction of B powder in target is conductive to sintering process, increasing hardness and flexural strength of targets. X-ray photoelectron spectrometer was used to characterize the composition and microstructure of LaB 6 nano-film which is tentatively considered to be composed of LaB 6 nanocrystalline and amorphous microstructure of La and B atoms. The film LaB 6.0627±0.02 was obtained when the ratio of B and La of sputtering target reached 12.5. The thickness and deposition rate decrease with the increase of B content in targets

  16. Lanthanum lead boro-tellurite glasses doped with samarium trioxide for luminescent devices application

    Science.gov (United States)

    Madhu, A.; Eraiah, B.

    2018-04-01

    Boro-tellurite based glasses (10La2O3-(20-x) TeO2-30PbO-40B2O3-xSm2O3) (x = 0, 0.5, 1.0 and 2.0 mol %) doped with different concentrations of Sm3+ ions has been investigated. The optical properties have been studied through spectroscopic measurements such as absorption and luminescence. Absorption spectra reveals nine peaks due to 6H5/2→6P3/2, 4I3/2+4F5/2+4I11/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, 6H15/2, and 6H13/2 transitions. Luminescence spectra under the excitation of 403 nm display four emission bands due to 4G5/2→6H5/2, 6H7/2, 6H9/2 and 6H11/2 transitions of Sm3+ ions. Among them 6H7/2 bright orange -red is more intense which proves that the present glasses are potential candidates for luminescent device applications in visible range as well as optical fibre communication since its refractive index is 1.65 high compared to other glasses.

  17. Selectively reflective transparent sheets

    Science.gov (United States)

    Waché, Rémi; Florescu, Marian; Sweeney, Stephen J.; Clowes, Steven K.

    2015-08-01

    We investigate the possibility to selectively reflect certain wavelengths while maintaining the optical properties on other spectral ranges. This is of particular interest for transparent materials, which for specific applications may require high reflectivity at pre-determined frequencies. Although there exist currently techniques such as coatings to produce selective reflection, this work focuses on new approaches for mass production of polyethylene sheets which incorporate either additives or surface patterning for selective reflection between 8 to 13 μ m. Typical additives used to produce a greenhouse effect in plastics include particles such as clays, silica or hydroxide materials. However, the absorption of thermal radiation is less efficient than the decrease of emissivity as it can be compared with the inclusion of Lambertian materials. Photonic band gap engineering by the periodic structuring of metamaterials is known in nature for producing the vivid bright colors in certain organisms via strong wavelength-selective reflection. Research to artificially engineer such structures has mainly focused on wavelengths in the visible and near infrared. However few studies to date have been carried out to investigate the properties of metastructures in the mid infrared range even though the patterning of microstructure is easier to achieve. We present preliminary results on the diffuse reflectivity using FDTD simulations and analyze the technical feasibility of these approaches.

  18. Formulation and Assessment of a Wash-Primer Containing Lanthanum "Tannate" for Steel Temporary Protection

    Science.gov (United States)

    D'Alessandro, Oriana; Selmi, Gonzalo J.; Deyá, Cecilia; Di Sarli, Alejandro; Romagnoli, Roberto

    2018-02-01

    Tannins are polyphenols synthesized by plants and useful for the coating industry as corrosion inhibitors. In addition, lanthanum salts have a great inhibitory effect on steel corrosion. The aim of this study was to obtain lanthanum "tannate" with adequate solubility to be incorporated as the corrosion inhibitor in a wash-primer. The "tannate" was obtained from commercial "Quebracho" tannin and 0.1 M La(NO3)3. The soluble tannin was determined by the Folin-Denis reagent, while the concentration of Lanthanum was obtained by a gravimetric procedure. The protective action of "tannate" on SAE 1010 steel was evaluated by linear polarization curves and corrosion potential measurements. Lanthanum "tannate" was incorporated in a wash-primer formulation and tested by corrosion potential and ionic resistance measurements. The corrosion rate was also determined by the polarization resistance technique. Besides, the primer was incorporated in an alkyd paint system and its anticorrosion performance assessed in the salt spray cabinet and by electrochemical impedance spectroscopy. Results showed that lanthanum "tannate" primer inhibits the development of deleterious iron oxyhydroxides on the steel substrate and incorporated into a paint system had a similar behavior to the primer formulated with zinc tetroxychromate.

  19. Bifunctional lanthanum phosphate substrates as novel adsorbents and biocatalyst supports for perchlorate removal

    Energy Technology Data Exchange (ETDEWEB)

    Sankar, Sasidharan [Materials Science and Technology Division (India); Prajeesh, Gangadharan Puthiya Veetil; Anupama, Vijaya Nadaraja [Process Engineering and Environmental Technology Division, CSIR – National Institute for Interdisciplinary Science and Technology, Industrial Estate P.O., Thiruvananthapuram 695019 (India); Krishnakumar, Bhaskaran [Process Engineering and Environmental Technology Division, CSIR – National Institute for Interdisciplinary Science and Technology, Industrial Estate P.O., Thiruvananthapuram 695019 (India); Academy of Scientific and Industrial Research (AcSIR) (India); Hareesh, Padinhattayil [Materials Science and Technology Division (India); Nair, Balagopal N. [R and D Centre, Noritake Co. Ltd., Aichi (Japan); Warrier, Krishna Gopakumar [Materials Science and Technology Division (India); Academy of Scientific and Industrial Research (AcSIR) (India); Hareesh, Unnikrishnan Nair Saraswathy, E-mail: hareesh@niist.res.in [Materials Science and Technology Division (India); Academy of Scientific and Industrial Research (AcSIR) (India)

    2014-06-30

    Graphical abstract: Porous lanthanum phosphate substrates, obtained by an environmentally benign thermal gelation process, performed the role of dual functional sorbent facilitating perchlorate adsorption and bioremediation through the growth of perchlorate reducing microbial colonies. - Highlights: • Lanthanum phosphate monoliths as efficient perchlorate adsorbents. • And also as substrates for biofilm (perchlorate reducing bacteria) growth. • Environmentally benign thermal gelation process for substrate fabrication. • 98% adsorption efficiency for perchlorate concentrations up to 100 μg/L. • The regenerated monoliths show nearly 100% reusability. - Abstract: Porous lanthanum phosphate substrates, obtained by an environmentally benign colloidal forming process employing methyl cellulose, are reported here as excellent adsorbents of perchlorate with >98% efficiency and with 100% reusability. Additionally, the effectiveness of such substrates as biocatalyst supports that facilitate biofilm formation of perchlorate reducing microbes (Serratia marcescens NIIST 5) is also demonstrated for the first time. The adsorption of perchlorate ions is attributed to the pore structure of lanthanum phosphate substrate and the microbial attachment is primarily ascribed to its intrinsic hydrophobic property. Lanthanum phosphate thus emerges as a dual functional material that possesses an integrated adsorption/bioremediation property for the effective removal of ClO{sub 4}{sup −} which is an increasingly important environmental contaminant.

  20. Bifunctional lanthanum phosphate substrates as novel adsorbents and biocatalyst supports for perchlorate removal

    International Nuclear Information System (INIS)

    Sankar, Sasidharan; Prajeesh, Gangadharan Puthiya Veetil; Anupama, Vijaya Nadaraja; Krishnakumar, Bhaskaran; Hareesh, Padinhattayil; Nair, Balagopal N.; Warrier, Krishna Gopakumar; Hareesh, Unnikrishnan Nair Saraswathy

    2014-01-01

    Graphical abstract: Porous lanthanum phosphate substrates, obtained by an environmentally benign thermal gelation process, performed the role of dual functional sorbent facilitating perchlorate adsorption and bioremediation through the growth of perchlorate reducing microbial colonies. - Highlights: • Lanthanum phosphate monoliths as efficient perchlorate adsorbents. • And also as substrates for biofilm (perchlorate reducing bacteria) growth. • Environmentally benign thermal gelation process for substrate fabrication. • 98% adsorption efficiency for perchlorate concentrations up to 100 μg/L. • The regenerated monoliths show nearly 100% reusability. - Abstract: Porous lanthanum phosphate substrates, obtained by an environmentally benign colloidal forming process employing methyl cellulose, are reported here as excellent adsorbents of perchlorate with >98% efficiency and with 100% reusability. Additionally, the effectiveness of such substrates as biocatalyst supports that facilitate biofilm formation of perchlorate reducing microbes (Serratia marcescens NIIST 5) is also demonstrated for the first time. The adsorption of perchlorate ions is attributed to the pore structure of lanthanum phosphate substrate and the microbial attachment is primarily ascribed to its intrinsic hydrophobic property. Lanthanum phosphate thus emerges as a dual functional material that possesses an integrated adsorption/bioremediation property for the effective removal of ClO 4 − which is an increasingly important environmental contaminant

  1. Types of defect ordering in undoped and lanthanum-doped Bi2201 single crystals

    International Nuclear Information System (INIS)

    Martovitsky, V. P.

    2006-01-01

    Undoped and lanthanum-doped Bi2201 single crystals having a perfect average structure have been comparatively studied by x-ray diffraction. The undoped Bi2201 single crystals exhibit very narrow satellite reflections; their half-width is five to six times smaller than that of Bi2212 single crystals grown by the same technique. This narrowness indicates three-dimensional defect ordering in the former crystals. The lanthanumdoped Bi2201 single crystals with x = 0.7 and T c = 8-10 K exhibit very broad satellite reflections consisting of two systems (modulations) misoriented with respect to each other. The modulation-vector components of these two modulations are found to be q 1 = 0.237b* + 0.277c* and q 2 = 0.238b* + 0.037c*. The single crystals having a perfect average structure and a homogeneous average distribution of doping lanthanum consist of 70-to 80-A-thick layers that alternate along the c axis and have two different types of modulated superlattice. The crystals having a less perfect average structure also consist of alternating layers, but they have different lanthanum concentrations. The low value of T c in the undoped Bi2201 single crystals (9.5 K) correlates with three-dimensional defect ordering in them, and an increase in T c to 33 K upon lanthanum doping can be related to a thin-layer structure of these crystals and to partial substitution of lanthanum for the bismuth positions

  2. Removal of Lanthanum (III) From Aqueous Solution Using Non-Living Water Hyacinth Roots

    International Nuclear Information System (INIS)

    Aly, A.; Amer, H.A.; Shawky, S.; Shawky, S.; Kandil, A.T.

    2013-01-01

    Removal of lanthanum (III) from aqueous solution using dried roots of water hyacinth (Eichhornia crassipes) has been investigated. The roots have been characterized by determining the ash percentage, the ph of the slurry, the elemental composition, the thermal gravimetric analysis, the surface area, the pore size, the zeta potential and ph of zero point charge. A surface area of 128 m 2 /g has been found and the micropore structure of the roots has been confirmed. Zeta potential and ph of zero point charge of the roots surfaces showed that they are positively charged within the ph range from 2 to 7.5. Sorption is rapid and depends on ph, weight of roots, concentration of lanthanum (III) and ionic strength. The sorption of lanthanum (III) was confirmed by scanning electron microscope, energy dispersive spectroscopy and the release of Ca +2 , Mg +2 and K +1 after sorption of lanthanum (III) have been indicated an ion exchange mechanism. Fourier transform infrared spectra indicated surface complexation mechanism, and sorption isotherms and kinetics were discussed. The roots were tested for removal of radioactive lanthanum ( 140 La) from simulated radioactive waste. Accepted June 2013.

  3. Silica doped with lanthanum sol–gel thin films for corrosion protection

    International Nuclear Information System (INIS)

    Abuín, M.; Serrano, A.; Llopis, J.; García, M.A.; Carmona, N.

    2012-01-01

    We present here anticorrosive silica coatings doped with lanthanum ions for the protection of metallic surfaces as an alternative to chromate (VI)-based conversion coatings. The coatings were synthesized by the sol–gel method starting from silicon alkoxides and two different lanthanum precursors: La (III) acetate hydrate and La (III) isopropoxide. Artificial corrosion tests in acid and alkaline media showed their effectiveness for the corrosion protection of AA2024 aluminum alloy sheets for coating prepared with both precursors. The X-ray absorption Near Edge Structure and X-ray Absorption Fine Structure analysis of the coatings confirmed the key role of lanthanum in the structural properties of the coating determining its anticorrosive properties. - Highlights: ► Silica sol–gel films doped with lanthanum ions were synthesized. ► Films from lanthanum-acetate and La-alkoxide were prepared for comparison purposes. ► La-acetate is an affordable chemical reactive preferred for the industry. ► Films properties were explored by scanning electron microscopy and X-Ray absorption spectroscopy. ► An alternative to anticorrosive pre-treatments for metallic surfaces is suggested.

  4. Silica doped with lanthanum sol-gel thin films for corrosion protection

    Energy Technology Data Exchange (ETDEWEB)

    Abuin, M. [Department of Materials Physics, Complutense University at Madrid, Avda. Complutense sn, 28004 Madrid (Spain); Serrano, A. [Glass and Ceramic Institute, CSIC, C. Kelsen 5, 28049 Madrid (Spain); Llopis, J. [Department of Materials Physics, Complutense University at Madrid, Avda. Complutense sn, 28004 Madrid (Spain); Garcia, M.A. [Glass and Ceramic Institute, CSIC, C. Kelsen 5, 28049 Madrid (Spain); IMDEA Nanoscience, Fco. Tomas y Valiente 7, 28049 Madrid (Spain); Carmona, N., E-mail: n.carmona@fis.ucm.es [Department of Materials Physics, Complutense University at Madrid, Avda. Complutense sn, 28004 Madrid (Spain)

    2012-06-01

    We present here anticorrosive silica coatings doped with lanthanum ions for the protection of metallic surfaces as an alternative to chromate (VI)-based conversion coatings. The coatings were synthesized by the sol-gel method starting from silicon alkoxides and two different lanthanum precursors: La (III) acetate hydrate and La (III) isopropoxide. Artificial corrosion tests in acid and alkaline media showed their effectiveness for the corrosion protection of AA2024 aluminum alloy sheets for coating prepared with both precursors. The X-ray absorption Near Edge Structure and X-ray Absorption Fine Structure analysis of the coatings confirmed the key role of lanthanum in the structural properties of the coating determining its anticorrosive properties. - Highlights: Black-Right-Pointing-Pointer Silica sol-gel films doped with lanthanum ions were synthesized. Black-Right-Pointing-Pointer Films from lanthanum-acetate and La-alkoxide were prepared for comparison purposes. Black-Right-Pointing-Pointer La-acetate is an affordable chemical reactive preferred for the industry. Black-Right-Pointing-Pointer Films properties were explored by scanning electron microscopy and X-Ray absorption spectroscopy. Black-Right-Pointing-Pointer An alternative to anticorrosive pre-treatments for metallic surfaces is suggested.

  5. Memory phenomenon in a lanthanum based bulk metallic glass

    International Nuclear Information System (INIS)

    Zhou, Ye; Huang, Wei Min; Zhao, Yong; Ding, Zhen; Li, Yan; Tor, Shu Beng; Liu, Erjia

    2016-01-01

    In this paper, we experimentally investigate two memory phenomena in a lanthanum based bulk metallic glass (BMG). While the temperature memory effect (TME) is not found by differential scanning calorimeter (DSC) test, shape recovery is observed in samples indented at both low and high temperatures. In terms of shape memory related characteristics, this BMG shares some features of shape memory alloys (SMAs) due to its metal nature, and some other features of shape memory polymers (SMPs) owing to its glassy–rubbery transition. The formation of protrusion in the polished sample after heating to super-cooled liquid region (SCLR) indicates that surface tension is not a necessarily positive contributor for shape recovery. Release of internal elastic stress is concluded as the major player. Although the amorphous nature of BMGs enables for storing appreciable amount of internal elastic stress upon deformation, without the presence of cross-linker as in typical SMPs, the shape recovery in BMGs is rather limited. - Highlights: • Experimental investigation of shape recovery in BMG. • Surface tension is not the major reason for shape recovery in BMG. • Release of internal stress is the major contributor for shape recovery. • Comparison of shape memory features of BMG with other shape memory materials.

  6. Polarization study on doped lanthanum gallate electrolyte using impedance spectroscopy

    Science.gov (United States)

    Gong, Wenquan; Gopalan, Srikanth; Pal, Uday B.

    2004-06-01

    Alternating current complex impedance spectroscopy studies were conducted on symmetrical cells of the type [gas, electrode/La1-x Sr x Ga1-y Mg y O3 (LSGM) electrolyte/electrode, gas]. The electrode materials were slurry-coated on both sides of the LSGM electrolyte support. The electrodes selected for this investigation are candidate materials for solid oxide fuel cell (SOFC) electrodes. Cathode materials include La1-x Sr x MnO3 (LSM), La1-x Sr x Co y Fe1-y O3 (LSCF), a two-phase particulate composite consisting of LSM and doped-lanthanum gallate (LSGM), and LSCF + LSGM. Pt metal electrodes were also used for the purpose of comparison. Anode material investigated was the Ni + Ce0.85Gd0.15O2 composite. The study revealed important details pertaining to the charge-transfer reactions that occur in such electrodes. The information obtained can be used to design electrodes for intermediate temperature SOFCs based on LSGM electrolytes.

  7. Electronic Conductivity of Doped-Lanthanum Gallate Electrolytes

    Science.gov (United States)

    Yamaji, Katsuhiko; Xiong, Yue Ping; Kishimoto, Haruo; Horita, Teruhisa; Sakai, Natsuko; Brito, Manuel E.; Yokokawa, Harumi

    Electronic conductivity of doped lanthanum gallate electrolytes were determined by using a Hebb-Wagner type polarization cell. Electronic conductivity of cobalt-doped, La0.8Sr0.2Ga0.8Mg0.15Co0.5O3-δ (LSGMC), and non cobalt-doped, La0.8Sr0.2Ga0.8Mg0.2O2.8 (LSGM8282), were measured as a function of oxygen partial pressures. The electronic conductivity of LSGM8282 showed a linear dependence on p(O2)1/4 in the higher p(O2) region, which is attributed to the electronic hole conductivity. The electronic conductivity of LSGMC showed a linear dependence on p(O2)1/6 in the higher p(O2) region. LSGMC has higher electronic conductivity than LSGM, and the conductivity was not clearly changed with temperatures between 600 and 800 °C. In lower p(O2) region, the electronic conductivity data have poor reproducibility and did not show any dependence on p(O2) because of the degradation of the electrolytes in severe reducing atmospheres.

  8. Removing Phosphorus from Aqueous Solutions Using Lanthanum Modified Pine Needles.

    Directory of Open Access Journals (Sweden)

    Xianze Wang

    Full Text Available The renewable pine needles was used as an adsorbent to remove phosphorus from aqueous solutions. Using batch experiments, pine needles pretreated with alkali-isopropanol (AI failed to effectively remove phosphorus, while pine needles modified with lanthanum hydroxide (LH showed relatively high removal efficiency. LH pine needles were effective at a wide pH ranges, with the highest removal efficiency reaching approximately 85% at a pH of 3. The removal efficiency was kept above 65% using 10 mg/L phosphorus solutions at desired pH values. There was no apparent significant competitive behavior between co-existing anions of sulfate, nitrate, and chloride (SO4(2-, NO3(- and Cl(-; however, CO3(2- exhibited increased interfering behavior as concentrations increased. An intraparticle diffusion model showed that the adsorption process occurred in three phases, suggesting that a boundary layer adsorption phenomena slightly affected the adsorption process, and that intraparticle diffusion was dominant. The adsorption process was thermodynamically unfavorable and non-spontaneous; temperature increases improved phosphorus removal. Total organic carbon (TOC assays indicated that chemical modification reduced the release of soluble organic compounds from 135.6 mg/L to 7.76 mg/L. This new information about adsorption performances provides valuable information, and can inform future technological applications designed to remove phosphorus from aqueous solutions.

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

    Science.gov (United States)

    Wahid, Kareem; Pokhrel, Madhab; Mao, Yuanbing

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

  10. Rare Earth Doped Lanthanum Calcium Borate Polycrystalline Red Phosphors

    Directory of Open Access Journals (Sweden)

    H. H. Xiong

    2014-01-01

    Full Text Available Single-phased Sm3+ doped lanthanum calcium borate (SmxLa2−xCaB10O19, SLCB, x=0.06 polycrystalline red phosphor was prepared by solid-state reaction method. The phosphor has two main excitation peaks located at 398.5 nm and 469.0 nm, which are nicely in accordance with the emitting wavelengths of commercial near-UV and blue light emitting diode chips. Under the excitation of 398.0 nm, the dominant red emission of Sm3+ in SLCB phosphor is centered at 598.0 nm corresponding to the transition of 4G5/2 → 6H7/2. The Eu3+ fluorescence in the red spectral region is applied as a spectroscopic probe to reveal the local site symmetry in the host lattice and, hence, Judd-Ofelt parameters Ωt  (t=2, 4 of Eu3+ in the phosphor matrix are derived to be 3.62×10-20 and 1.97×10-20 cm2, indicating a high asymmetrical and strong covalent environment around rare earth luminescence centers. Herein, the red phosphors are promising good candidates employed in white light emitting diodes (LEDs illumination.

  11. Tm3+ activated lanthanum phosphate: a blue PDP phosphor

    International Nuclear Information System (INIS)

    Rao, R.P.

    2005-01-01

    Plasma display panels (PDPs) are gaining attention due to their high performance and scalability as a medium for large format TVs. The performance and life of a PDP strongly depends upon the nature of phosphors. Currently, Eu 2+ activated barium magnesium aluminate (BAM) is being used as a blue component. Because of its low life, efforts are being made to explore new blue emitting phosphors. One of the alternatives to BAM is Tm 3+ activated lanthanum phosphate (LPTM) phosphor. LPTM phosphor samples are prepared by a solid-state as well as sol-gel process in presence of flux. The phosphor of the present investigation, having uniform and spherical shape particles in the range of 0.1-2 μm, is appropriate for thin phosphor screens required for PDP applications. It exhibits a narrow band emission in the blue region, peaking at 452 nm and also a number of narrow bands in the UV region when excited by 147 and 173 nm radiation from a xenon gas mixture. Various possible transitions responsible for UV and visible emission from Tm 3+ ion are presented. These phosphors also exhibit good color saturation and better stability when excited with VUV radiation. To achieve higher brightness, they are blended with other UV excited blue emitting phosphors such as BAM. Results related to morphology, excitation, after glow decay, emission and degradation of these phosphors in the powder form as well as in plasma display panels are presented and discussed

  12. Memory phenomenon in a lanthanum based bulk metallic glass

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ye [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Huang, Wei Min, E-mail: mwmhuang@ntu.edu.sg [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Zhao, Yong [School of Chemistry and Chemical Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013 (China); Ding, Zhen [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Li, Yan [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Tor, Shu Beng; Liu, Erjia [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore)

    2016-07-05

    In this paper, we experimentally investigate two memory phenomena in a lanthanum based bulk metallic glass (BMG). While the temperature memory effect (TME) is not found by differential scanning calorimeter (DSC) test, shape recovery is observed in samples indented at both low and high temperatures. In terms of shape memory related characteristics, this BMG shares some features of shape memory alloys (SMAs) due to its metal nature, and some other features of shape memory polymers (SMPs) owing to its glassy–rubbery transition. The formation of protrusion in the polished sample after heating to super-cooled liquid region (SCLR) indicates that surface tension is not a necessarily positive contributor for shape recovery. Release of internal elastic stress is concluded as the major player. Although the amorphous nature of BMGs enables for storing appreciable amount of internal elastic stress upon deformation, without the presence of cross-linker as in typical SMPs, the shape recovery in BMGs is rather limited. - Highlights: • Experimental investigation of shape recovery in BMG. • Surface tension is not the major reason for shape recovery in BMG. • Release of internal stress is the major contributor for shape recovery. • Comparison of shape memory features of BMG with other shape memory materials.

  13. Synthesis of lanthanum tungstate interconnecting nanoparticles by high voltage electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Keereeta, Yanee, E-mail: ynkeereeta@gmail.com [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongtem, Titipun, E-mail: ttpthongtem@yahoo.com [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongtem, Somchai [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2015-10-01

    Graphical abstract: - Highlights: • La{sub 2}(WO{sub 4}){sub 3} as one of semiconducting materials. • H.V. electrospinning was used to synthesize La{sub 2}(WO{sub 4}){sub 3} interconnecting nanoparticles. • A promising material for photoemission. - Abstract: Lanthanum tungstate (La{sub 2}(WO{sub 4}){sub 3}) interconnecting nanoparticles in the shape of fibers were successfully synthesized by electrospinning in combination with high temperature calcination. In this research, calcination temperature for the synthesis of the fibers evidently influenced the diameter, morphology and crystalline degree. The crystalline monoclinic La{sub 2}(WO{sub 4}){sub 3} fibers with 200–700 nm in diameter, two main Raman peaks at 945 and 927 cm{sup −1}, FTIR stretching modes at 936 and 847 cm{sup −1}, 2.02 eV energy gap and 415–430 nm blue emission were synthesized by calcination of inorganic/organic hybrid fibers at 750 °C for 5 h, characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV–visible spectroscopy and photoluminescence (PL) spectroscopy. The surface of the composite fibers before calcination was very smooth. Upon calcination the composite fibers at 750 °C for 5 h, they were transformed into nanoparticles join together in the shape of fibers with rough surface.

  14. Specific heat studies of lanthanum and yttrium sesquicarbides

    International Nuclear Information System (INIS)

    Cort, B.; Stewart, G.R.; Giorgi, A.L.

    1984-01-01

    The specific heats of the sesquicarbides LaC/sub 1.35/ and La/sub 0.9/Th/sub 0.1/C/sub 1.6/ (prepared by arc melting) and YC/sub 1.35/ (prepared by a high-pressure technique) have been measured for the first time. No bulk specific heat anomaly appears in either lanthanum compounds, even though (1) inductively measured superconducting transition temperatures are respectively high (11.0 K for LaC/sub 1.35/ and 12.7 K for La/sub 0.9/Th/sub 0.1/C/sub 1.6/) and (2) YC/sub 1.35/ is a bulk superconductor with a T/sub c/ = 10.5 K and Y/sub 0.7/Th/sub 0.3/C/sub 1.58/ (also prepared by high pressure) was previously reported to be a bulk superconductor with a T/sub c/ = 17.1 K. The apparent correlation with preparation technique is discussed

  15. Polarization of lanthanum nucleus by dynamic polarization method

    International Nuclear Information System (INIS)

    Adachi, Toshikazu; Ishimoto, Shigeru; Masuda, Yasuhiro; Morimoto, Kimio

    1989-01-01

    Preliminary studies have been carried out concerning the application of a dynamic polarization method to polarizing lanthanum fluoride single crystal to be employed as target in experiments with time reversal invariance. The present report briefly outlines the dynamic polarization method and describes some preliminary studies carried out so far. Dynamic polarization is of particular importance because no techniques are currently available that can produce highly polarized static nucleus. Spin interaction between electrons and protons (nuclei) plays a major role in the dynamic polarization method. In a thermal equilibrium state, electrons are polarized almost completely while most protons are not polarized. Positively polarized proton spin is produced by applying microwave to this system. The most hopeful candidate target material is single crystal of LaF 3 containing neodymium because the crystal is chemically stable and easy to handle. The spin direction is of great importance in experiments with time reversal invariance. The spin of neutrons in the target can be cancelled by adjusting the external magnetic field applied to a frozen polarized target. In a frozen spin state, the polarity decreases slowly with a relaxation time that depends on the external magnetic field and temperature. (N.K.)

  16. Nuclear deterrence: which environmental transparency?

    International Nuclear Information System (INIS)

    Cherief, Hamza

    2012-01-01

    This article addresses the field of nuclear geopolitics. The author discusses the tensions between the principle of transparency regarding environmental issues on the one hand, and the protection of nuclear deterrence as instrument of power on the other hand. According to the French law, the preservation of nuclear power instruments means the acknowledgement of a legal regime which is specific to national defence requirements in terms of secret and right to information. Thus, the author discusses the constitutional limitations of the environmental transparency obligation for the protection of Nation's fundamental interests. Then, by commenting the Rainbow Warrior affair, the author highlights the exceptional limitations of the transparency requirement regarding nuclear issues

  17. Transparency masters for mathematics revealed

    CERN Document Server

    Berman, Elizabeth

    1980-01-01

    Transparency Masters for Mathematics Revealed focuses on master diagrams that can be used for transparencies for an overhead projector or duplicator masters for worksheets. The book offers information on a compilation of master diagrams prepared by John R. Stafford, Jr., audiovisual supervisor at the University of Missouri at Kansas City. Some of the transparencies are designed to be shown horizontally. The initial three masters are number lines and grids that can be used in a mathematics course, while the others are adaptations of text figures which are slightly altered in some instances. The

  18. Polarization-independent transparency window induced by complementary graphene metasurfaces

    International Nuclear Information System (INIS)

    Lu, Wei Bing; Liu, Ji Long; Zhang, Jin; Wang, Jian; Liu, Zhen Guo

    2017-01-01

    A fourfold symmetric graphene-based complementary metasurface featuring a polarization-independent transparency window is proposed and numerically analysed in this paper. The unit cell of the metamaterial consists of a monolayer graphene perforated with a cross and four identical split-ring resonators deposited on a substrate. Our analysis shows that the transparency window can be interpreted as a plasmonic analogy of Autler–Townes splitting. The polarization independence is achieved due to the fourfold symmetry of graphene’s complementary structure. In addition, the frequency range of the transparency window can be dynamically tuned over a broad band by changing the chemical potential of graphene, and the width of the transparency window can also be controlled by changing the split-gap orientation. This work may lead to potential applications in many area, such as slow-light devices and optical sensing. (paper)

  19. Impact of data transparency: Scientific publications.

    Science.gov (United States)

    Joshi, Mohit; Bhardwaj, Payal

    2018-01-01

    Data transparency has been an important aspect of medical research as it helps in enabling evidence-based decisions in medicine which leads to foster trust among the patients and research community alike. Currently, it is one of the key talking points owing to a number of initiatives taken by the pharmaceutical organizations, regulatory bodies, and the other decision enablers of the industry. Thanks to this, there are a number of ways by which a single piece of datum is available through multiple access points, namely, clinical trial disclosures (CTDs), clinical study reports (CSRs), plain language summaries, and scientific publications including abstracts, posters, and manuscripts, to name a few. This may pose a burden of documentation on the pharmaceutical organizations, demanding downsizing of medical writing documents. Since CTDs, CSRs, and other regulatory document are more or less template driven; there may not be much scope to interfere with their structure and submission timings. Scientific publications, on the other hand, provide the flexibility of presenting the clinical data that is typically not dependent on a particular format and timelines. The present paper discusses how the upcoming data transparency initiatives could affect the publication practices across the pharmaceutical industry and what could pharmaceutical companies do to get the maximum benefit out of the data transparency initiatives.

  20. Transparency of Magnetized Plasma at Cyclotron Frequency

    International Nuclear Information System (INIS)

    G. Shvets; J.S. Wurtele

    2002-03-01

    Electromagnetic radiation is strongly absorbed by a magnetized plasma if the radiation frequency equals the cyclotron frequency of plasma electrons. It is demonstrated that absorption can be completely canceled in the presence of a magnetostatic field of an undulator or a second radiation beam, resulting in plasma transparency at the cyclotron frequency. This effect is reminiscent of the electromagnetically induced transparency (EIT) of the three-level atomic systems, except that it occurs in a completely classical plasma. Unlike the atomic systems, where all the excited levels required for EIT exist in each atom, this classical EIT requires the excitation of the nonlocal plasma oscillation. The complexity of the plasma system results in an index of refraction at the cyclotron frequency that differs from unity. Lagrangian description was used to elucidate the physics and enable numerical simulation of the plasma transparency and control of group and phase velocity. This control naturally leads to applications for electromagnetic pulse compression in the plasma and electron/ion acceleration

  1. Effect of noble metal doping on the structural properties of lanthanum cobaltite

    International Nuclear Information System (INIS)

    Dharmadhikari, Dipti V.; Athawal, Anjali A.

    2016-01-01

    Pristine and Noble metal (Ag and Pd) doped lanthanum cobaltite samples have been synthesised by Hydrothermal method. Lanthanum in the A-Site and Co at B-site of Lanthanum cobaltite (LaCoO 3 ) perovskites were partially doped by silver and palladium (4%). Crystal structure analysis revealed that the hydrothermal synthesis led to the formation of pure nanocrystalline perovskite structure. Morphological analysis of the samples shows that the noble metal doping affects the morphology of the samples. Pristine sample shows spherical to oval shaped particles while the doping results in the formation of irregular shaped, spherical and rod shaped particles. Silver doping results in the agglomeration of particles. The particles were observed to be fused with each other to form rod shaped structures in case of palladium doped samples. (author)

  2. PMR investigation into complexes of lanthanum and lutetium with ethylenediaminediacetic acid

    International Nuclear Information System (INIS)

    Kostromina, N.A.; Novikova, L.B.

    1975-01-01

    Proton resonance spectra of ethylendiaminediacetic acid (EDDA) and EDDA mixtures with La and Lu as function of pH of solution was studied. Sequence of EDDA (A 2- ) protonation was established; cations H 3 A + and H 4 A 2+ were found; dissociation constants of above mentioned cations were determined. Formation of H 2 LnA 3+ , HLnA 2+ and LnA + complexes in EDDA-Ln (1:1) system was found. Difference in the bonds mobility of lanthanum and lutetium complexes was determined: lanthanum forms complexes with labile, lutetium with non-labile bonds. Information on complexes structure is collected. Acid dissociation constants of protonated complexes of lanthanum with EDDA were determined

  3. Exchange, x-ray and IR spectral behaviour of lanthanum and praseodymium exchanged zeolite X

    International Nuclear Information System (INIS)

    Das, D.; Upreti, M.C.

    1995-01-01

    Exchange behaviour of lanthanum and praseodymium ions in zeolite X involves three steps: preferential exchange, intrazeolitic exchange and irreversible exchange. At room temperature , higher exchange has been observed with La(III) than with Pr(III) which is attributed to the smaller hydrosphere of lanthanum than praseodymium. IR spectra of these zeolites in KBr pellets show a shift in the major Si-O stretching vibration of 972 cm -1 to higher frequencies. Their x-ray diffraction patterns remain unchanged except a large decrease of the line intensities caused by the absorption of x-rays by heavy La(III) and Pr(III) ions. The present study reports the preparation and physicochemical properties of lanthanum and praseodymium exchanged zeolite X. (author). 12 refs., 3 figs., 3 tabs

  4. On dependence of stability of lanthanum complexes with aminopolycarboxylic acids on the complex structure

    International Nuclear Information System (INIS)

    Poluehktov, N.S.; Meshkova, S.B.; Danilkovich, M.M.; Topilova, Z.M.

    1985-01-01

    Regularities in changes of stability constants of lanthanum complexes with aminopolycarboxylic acids (APA) versus their structure are studied, The stability of lathanum-APA complexes depends mainly on the number of carboxyl groups in a ligand molecule. At that, the highest stability constant is characteristic of a complex with a ligand, containing 3 nitrogen atoms and 5 carboxyl groups, in the presenoe of which the lanthanum ion coordination sphere gets satupated. The oxyethy group introduction into a ligand molecule also improves the lanthanum complex stability but to a lesser degree than during the introduction of a carboxyl group. The number of nitrogen atoms in a ligand polecule affects insignificantly the complex stability constant value, and the elongation of a chain of CH 2 groups, separating nitrogen atoms, reduces the constant to a -0.6 power

  5. Strengthening Transparency in Regulatory Science

    Science.gov (United States)

    Where available and appropriate, EPA will use peer-reviewed information, standardized test methods, consistent data evaluation procedures, and good laboratory practices to ensure transparent, understandable, and reproducible scientific assessments.

  6. Transparency in Cooperative Online Education

    DEFF Research Database (Denmark)

    Dalsgaard, Christian; Paulsen, Morten Flate

    2009-01-01

    The purpose of this article is to discuss the following question: What is the potential of social networking within cooperative online education? Social networking does not necessarily involve communication, dialogue, or collaboration. Instead, the authors argue that transparency is a unique...... feature of social networking services. Transparency gives students insight into each other’s actions. Cooperative learning seeks to develop virtual learning environments that allow students to have optimal individual freedom within online learning communities. This article demonstrates how cooperative...... learning can be supported by transparency. To illustrate this with current examples, the article presents NKI Distance Education’s surveys and experiences with cooperative learning. The article discusses by which means social networking and transparency may be utilized within cooperative online education...

  7. Transparent Memory For Harsh Electronics

    KAUST Repository

    Ho, C. H.; Duran Retamal, Jose Ramon; Yang, P. K.; Lee, C. P.; Tsai, M. L.; Kang, C. F.; He, Jr-Hau

    2017-01-01

    As a new class of non-volatile memory, resistive random access memory (RRAM) offers not only superior electronic characteristics, but also advanced functionalities, such as transparency and radiation hardness. However, the environmental tolerance

  8. The influence of lake water alkalinity and humic substances on particle dispersion and lanthanum desorption from a lanthanum modified bentonite.

    Science.gov (United States)

    Reitzel, Kasper; Balslev, Kristiane Astrid; Jensen, Henning S

    2017-11-15

    A 12 days laboratory study on potential desorption of Lanthanum (La) from a commercial La modified clay (Phoslock) was conducted using lake water from 17 Danish lakes with alkalinities between 0.02 and 3.7 meq L -1 and varying concentrations of DOC and humic acids (HA's). A similar study was conducted in artificial lake water with alkalinities from 0 to 2.5 meq L -1 in order to exclude interference from dissolved HA's. To test if La in solution (FLa) was associated with fine particles, the water samples were filtered sequentially through three filter sizes (1.2 μm, 0.45 μm and 0.2 μm), and finally, ultracentrifugation was used in an attempt to separate colloidal La from dissolved La. The study showed that higher FLa (up to 2.5 mg L -1 or 14% of the total La in the Phoslock) concentrations were found in soft water lakes compared to hard water lakes, probably due to dispersion of the clay at low alkalinities. In addition, this study showed that HA's seem to increase the FLa concentrations in soft water lakes, most likely through complexation of La retained in the Phoslock matrix. In summary, we conclude that elevated La concentrations in lake water after a Phoslock treatment should only be expected in soft water lakes rich in DOC and HA's. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. The influence of lake water alkalinity and humic substances on particle dispersion and lanthanum desorption from a lanthanum modified bentonite

    DEFF Research Database (Denmark)

    Reitzel, Kasper; Balslev, Kristiane Astrid; Jensen, Henning S

    2017-01-01

    A 12 days laboratory study on potential desorption of Lanthanum (La) from a commercial La modified clay (Phoslock) was conducted using lake water from 17 Danish lakes with alkalinities between 0.02 and 3.7 meq L-1and varying concentrations of DOC and humic acids (HA's). A similar study...... was conducted in artificial lake water with alkalinities from 0 to 2.5 meq L-1in order to exclude interference from dissolved HA's. To test if La in solution (FLa) was associated with fine particles, the water samples were filtered sequentially through three filter sizes (1.2 μm, 0.45 μm and 0.2 μm...... at low alkalinities. In addition, this study showed that HA's seem to increase the FLa concentrations in soft water lakes, most likely through complexation of La retained in the Phoslock matrix. In summary, we conclude that elevated La concentrations in lake water after a Phoslock treatment should only...

  10. Highly efficient fully transparent inverted OLEDs

    Science.gov (United States)

    Meyer, J.; Winkler, T.; Hamwi, S.; Schmale, S.; Kröger, M.; Görrn, P.; Johannes, H.-H.; Riedl, T.; Lang, E.; Becker, D.; Dobbertin, T.; Kowalsky, W.

    2007-09-01

    One of the unique selling propositions of OLEDs is their potential to realize highly transparent devices over the visible spectrum. This is because organic semiconductors provide a large Stokes-Shift and low intrinsic absorption losses. Hence, new areas of applications for displays and ambient lighting become accessible, for instance, the integration of OLEDs into the windshield or the ceiling of automobiles. The main challenge in the realization of fully transparent devices is the deposition of the top electrode. ITO is commonly used as transparent bottom anode in a conventional OLED. To obtain uniform light emission over the entire viewing angle and a low series resistance, a TCO such as ITO is desirable as top contact as well. However, sputter deposition of ITO on top of organic layers causes damage induced by high energetic particles and UV radiation. We have found an efficient process to protect the organic layers against the ITO rf magnetron deposition process of ITO for an inverted OLED (IOLED). The inverted structure allows the integration of OLEDs in more powerful n-channel transistors used in active matrix backplanes. Employing the green electrophosphorescent material Ir(ppy) 3 lead to IOLED with a current efficiency of 50 cd/A and power efficiency of 24 lm/W at 100 cd/m2. The average transmittance exceeds 80 % in the visible region. The on-set voltage for light emission is lower than 3 V. In addition, by vertical stacking we achieved a very high current efficiency of more than 70 cd/A for transparent IOLED.

  11. Lines that induce phenomenal transparency.

    Science.gov (United States)

    Grieco, Alba; Roncato, Sergio

    2005-01-01

    Three neighbouring opaque surfaces may appear split into two layers, one transparent and one opaque beneath, if an outline contour is drawn that encompasses two of them. The phenomenon was originally observed by Kanizsa [1955 Rivista di Psicologia 69 3-19; 1979 Organization in Vision: Essays on Gestalt Psychology (New York: Praeger)], for the case where an outline contour is drawn to encompass one of the two parts of a bicoloured figure and a portion of a background of lightest (or darkest) luminance. Preliminary observations revealed that the outline contour yields different effects: in addition to the stratification into layers described by Kanizsa, a second split, opposite in depth order, may occur when the outline contour is close in luminance to one of the three surfaces. An initial experiment was designed to investigate what conditions give rise to the two phenomenal transparencies: this led to the conclusion that an outline contour superimposed on an opaque surface causes this surface to emerge as a transparent layer when the luminances of the contour and the surface differ, in absolute value, by no more than 13.2 cd m(-2). We have named this phenomenon 'transparency of the intercepted surface', to distinguish it from the phenomenal transparency arising when the contour and surface are very different in luminance. When such a difference exists, the contour acts as a factor of surface definition and grouping: the portion of the homogeneous surface it bounds emerges as a fourth surface and groups with a nearby surface if there is one close in luminance. The transparency phenomena ('transparency of the contoured surface') perceived in this context conform to the constraints of Metelli's model, as demonstrated by a second experiment, designed to gather 'opacity' ratings of stimuli. The observer judgments conformed to the values predicted by Metelli's formula for perceived degree of transparency, alpha. The role of the outline contour in conveying figural and

  12. A Concise Dictionary of Transparency

    Directory of Open Access Journals (Sweden)

    Jakub Misun

    2013-01-01

    Full Text Available The article discusses an essay collection by Marek Bieńczyk, Przeźroczystość [Transparency]. The concept, placed in various context, shows various aspects and is seen in various shades. The author does not put forward a statement, but rather proposes a work to be done: to determine the modality of transparency. The concept initially seems to be mainly epistemological: the cognizant subject would like to make the world transparent, to discover all possible mysteries. Before that, however, the subject must know itself, and here the dream of trans­parency also plays the key role. Lack of epistemological transparency is the main cause of melancholy and its reverse — hysteria. The concept turns out to be important in the domain of love — the loer thinks that (she knows the desired person more better anybody else, that (she has entirely penetrated the subjectivity of the Other. Ultimately, however, the dream of transparency goes down to a slow demise of the subject: as self-discovery progresses, there is less and less of the discoverer. In conclusion of this work, the border of modality of the concept turns out to be horrifyingly obvious. The desire for transparency consequently searches not for knowledge, but for an escape whose name is death.

  13. Semi-transparent solar cells

    International Nuclear Information System (INIS)

    Sun, J; Jasieniak, J J

    2017-01-01

    Semi-transparent solar cells are a type of technology that combines the benefits of visible light transparency and light-to-electricity conversion. One of the biggest opportunities for such technologies is in their integration as windows and skylights within energy-sustainable buildings. Currently, such building integrated photovoltaics (BIPV) are dominated by crystalline silicon based modules; however, the opaque nature of silicon creates a unique opportunity for the adoption of emerging photovoltaic candidates that can be made truly semi-transparent. These include: amorphous silicon-, kesterite-, chalcopyrite-, CdTe-, dye-sensitized-, organic- and perovskite- based systems. For the most part, amorphous silicon has been the workhorse in the semi-transparent solar cell field owing to its established, low-temperature fabrication processes. Excitement around alternative classes, particularly perovskites and the inorganic candidates, has recently arisen because of the major efficiency gains exhibited by these technologies. Importantly, each of these presents unique opportunities and challenges within the context of BIPV. This topic review provides an overview into the broader benefits of semi-transparent solar cells as building-integrated features, as well as providing the current development status into all of the major types of semi-transparent solar cells technologies. (topical review)

  14. Semi-transparent solar cells

    Science.gov (United States)

    Sun, J.; Jasieniak, J. J.

    2017-03-01

    Semi-transparent solar cells are a type of technology that combines the benefits of visible light transparency and light-to-electricity conversion. One of the biggest opportunities for such technologies is in their integration as windows and skylights within energy-sustainable buildings. Currently, such building integrated photovoltaics (BIPV) are dominated by crystalline silicon based modules; however, the opaque nature of silicon creates a unique opportunity for the adoption of emerging photovoltaic candidates that can be made truly semi-transparent. These include: amorphous silicon-, kesterite-, chalcopyrite-, CdTe-, dye-sensitized-, organic- and perovskite- based systems. For the most part, amorphous silicon has been the workhorse in the semi-transparent solar cell field owing to its established, low-temperature fabrication processes. Excitement around alternative classes, particularly perovskites and the inorganic candidates, has recently arisen because of the major efficiency gains exhibited by these technologies. Importantly, each of these presents unique opportunities and challenges within the context of BIPV. This topic review provides an overview into the broader benefits of semi-transparent solar cells as building-integrated features, as well as providing the current development status into all of the major types of semi-transparent solar cells technologies.

  15. Accelerating Biomedical Discoveries through Rigor and Transparency.

    Science.gov (United States)

    Hewitt, Judith A; Brown, Liliana L; Murphy, Stephanie J; Grieder, Franziska; Silberberg, Shai D

    2017-07-01

    Difficulties in reproducing published research findings have garnered a lot of press in recent years. As a funder of biomedical research, the National Institutes of Health (NIH) has taken measures to address underlying causes of low reproducibility. Extensive deliberations resulted in a policy, released in 2015, to enhance reproducibility through rigor and transparency. We briefly explain what led to the policy, describe its elements, provide examples and resources for the biomedical research community, and discuss the potential impact of the policy on translatability with a focus on research using animal models. Importantly, while increased attention to rigor and transparency may lead to an increase in the number of laboratory animals used in the near term, it will lead to more efficient and productive use of such resources in the long run. The translational value of animal studies will be improved through more rigorous assessment of experimental variables and data, leading to better assessments of the translational potential of animal models, for the benefit of the research community and society. Published by Oxford University Press on behalf of the Institute for Laboratory Animal Research 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  16. Separation of lanthanum from samarium on solid aluminum electrode in LiCl-KCl eutectic melts

    International Nuclear Information System (INIS)

    De-Bin Ji; Mi-Lin Zhang; Xing Li; Xiao-Yan Jing; Wei Han; Yong-De Yan; Yun Xue; Zhi-Jian Zhang; Harbin Engineering University, Harbin

    2015-01-01

    This paper presents an electrochemical study on the separation of lanthanum from samarium on aluminum electrode at 773 K. The results from different electrochemical methods showed that Sm(III) and La(III) formed Al-Sm and Al-La intermetallic compounds on an aluminum electrode at electrode potential around -1.67 and -1.46 V, respectively. The electrochemical separation of lanthanum was carried out in LiCl-KCl-LaCl 3 -SmCl 3 melts on solid aluminum electrodes at 773 K by potentiostatic electrolysis at -1.45 V for 40 h and the separation efficiency was 99.1 %. (author)

  17. Lanthanum Deposition in the Stomach in the Absence of Helicobacter pylori Infection.

    Science.gov (United States)

    Iwamuro, Masaya; Urata, Haruo; Tanaka, Takehiro; Kawano, Seiji; Kawahara, Yoshiro; Kimoto, Katsuhiko; Okada, Hiroyuki

    2018-03-15

    In this case report, we describe two patients who showed a diffusely whitish mucosa in the posterior wall and the lesser curvature of the gastric body. The patients were serologically- and histopathologically-negative for Helicobacter pylori. Random biopsy specimens from the stomach revealed no regenerative changes, intestinal metaplasia, and/or foveolar hyperplasia in either of the patients. Although lanthanum deposition in the gastric mucosa has been reported to occur in close association with H. pylori-associated gastritis, our patients tested negative for H. pylori. These cases suggest that lanthanum deposition presents as whitish lesions in the gastric body in H. pylori-negative patients.

  18. Conductometric study of lanthanum chloride interaction with potash soaps of higher fatty acids

    International Nuclear Information System (INIS)

    Skrylev, L.D.; Sazonova, V.F.; Kornelli, M.Eh.; Shumilina, N.A.

    1978-01-01

    Interaction of lanthanum chloride with potassium salts of higher aliphatic acids, containing from 10 to 16 carbon atoms, at room temperature in weakly acid media (pH=5.5) gives rise to neutral soaps of the La[CHsub(3)(CHsub(2))sub(n)COO]sub(3) composition, while in alkaline media (pH=8.0) base soaps of the LaOH[CHsub(3)(CHsub(2))sub(n)COO]sub(2) composition are formed. In acid solutions (pH=2.0) no interaction of lanthanum chloride with potassium soaps of the above carboxylic acids is observed

  19. Order parameters in lanthanum gallate lightly doped with manganese and paramagnetic resonance

    Science.gov (United States)

    Vazhenin, V. A.; Potapov, A. P.; Artyomov, M. Yu.; Guseva, V. B.

    2010-09-01

    The Cr3+ centers have been revealed, transitions at room temperature have been identified, and spin Hamiltonian parameters have been determined for the Cr3+ and Fe3+ triclinic centers in lanthanum gallate lightly doped with manganese. The principal axes of the fourth-rank fine-structure tensor for the Fe3+ triclinic centers have been established and used to determine the order parameters, i.e., the angles of rotation of oxygen octahedra of lanthanum gallate with respect to the perovskite structure. The order parameter in the rhombohedral phase has been estimated.

  20. Effects of adding lanthanum to Ni/ZrO2 catalysts on ethanol steam reforming

    International Nuclear Information System (INIS)

    Profeti, Luciene Paula Roberto; Habitzheuter, Filipe; Assaf, Elisabete Moreira

    2012-01-01

    The catalytic performance of Ni/ZrO 2 catalysts loaded with different lanthanum content for steam reforming of ethanol was investigated. Catalysts were characterized by BET surface area, X-ray diffraction, UV-vis spectroscopy, temperature programmed reduction, and X-ray absorption fine structure techniques. Results showed that lanthanum addition led to an increase in the degree of reduction of both NiO and nickel surface species interacting with the support, due to the higher dispersion effect. The best catalytic performance at 450 deg C was found for the Ni/12LZ catalyst, which exhibited an effluent gaseous mixture with the highest H 2 yield. (author)

  1. Introducing modern technology to promote transparency in health services.

    Science.gov (United States)

    Islam, Mohammad Shafiqul

    2015-01-01

    Quantitative indicators show that Bangladeshi maternal and child healthcare is progressing satisfactorily. However, healthcare quality is still inadequate. It is hypothesised that modern technology enhances healthcare quality. Therefore, the purpose of this paper is to investigate how modern technology such as electronic record keeping and the internet can contribute to enhancing Bangladeshi healthcare quality. This study also explores how socio-economic and political factors affect the healthcare quality. This paper is based on a qualitative case study involving 68 in-depth interviews with healthcare professionals, elected representatives, local informants and five focus group discussions with healthcare service users to understand technology's effect on health service quality. The study has been conducted in one rural and one urban service organisations to understand how various factors contribute differently to healthcare quality. The findings show that modern technology, such as the internet and electronic devices for record keeping, contribute significantly to enhancing health service transparency, which in turn leads to quality health and family planning services. The findings also show that information and communication technology (ICT) is an effective mechanism for reducing corruption and promoting transparency. However, resource constraints impact adversely on the introduction of technology, which leads to less transparent healthcare. Progress in education and general socio-economic conditions makes it suitable to enhance ICT usage, which could lead to healthcare transparency, but political and bureaucratic factors pose a major challenge to ensure transparency. This paper can be a useful guide for promoting governance and healthcare quality in developing countries including Bangladesh. It analyses the ICT challenges that healthcare staff face when promoting transparent healthcare. This paper provides a deeper understanding of transparency and healthcare

  2. Lanthanum manganate based cathodes for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Juhl Joergensen, M.

    2001-07-01

    Composite cathodes for solid oxide fuel cells were investigated using electrochemical impedance spectroscopy and scanning electron microscopy. The aim was to study the oxygen reduction process in the electrode in order to minimise the voltage drop in the cathode. The electrodes contained a composite layer made from lanthanum strontium manganate (LSM) and yttria stabilised zirconia (YSZ) and a layer of pure LSM aimed for current collection. The performance of the composite electrodes was sensitive to microstructure and thickness. Further, the interface between the composite and the current collecting layer proved to affect the performance. In a durability study severe deg-radation of the composite electrodes was found when passing current through the electrode for 2000 hours at 1000 deg. C. This was ascribed to pore formation along the composite interfaces and densification of the composite and current collector microstructure. An evaluation of the measurement approach indicated that impedance spectroscopy is a very sensitive method. This affects the reproducibility, as small undesirable variations in for instance the microstructure from electrode to electrode may change the impedance. At least five processes were found to affect the impedance of LSM/YSZ composite electrodes. Two high frequency processes were ascribed to transport of oxide ions/oxygen intermediates across LSM/YSZ interfaces and through YSZ in the composite. Several competitive elementary reaction steps, which appear as one medium frequency process in the impedance spectra, were observed. A low frequency arc related to gas diffusion limitation in a stagnant gas layer above the composite structure was detected. Finally, an inductive process, assumed to be connected to an activation process involving segregates at the triple phase boundary between electrode, electrolyte and gas phase, was found. (au)

  3. Back bombardment for dispenser and lanthanum hexaboride cathodes

    Directory of Open Access Journals (Sweden)

    Mahmoud Bakr

    2011-06-01

    Full Text Available The back bombardment (BB effect limits wide usage of thermionic rf guns. The BB effect induces not only ramping-up of a cathode’s temperature and beam current, but also degradation of cavity voltage and beam energy during a macropulse. This paper presents a comparison of the BB effect for the case of dispenser tungsten-base (DC and lanthanum hexaboride (LaB_{6} thermionic rf gun cathodes. For each, particle simulation codes are used to simulate the BB effect and electron beam dynamics in a thermionic rf gun cathode. A semiempirical equation is also used to investigate the stopping range and deposited heat power of BB electrons in the cathode material. A numerical simulation method is used to calculate the change of the cathode temperature and current density during a single macropulse. This is done by solving two differential equations for the rf gun cavity equivalent circuit and one-dimensional thermal diffusion equation. High electron emission and small beam size are required for generation of a high-brightness electron beam, and so in this work the emission properties of the cathode are taken into account. Simulations of the BB effect show that, for a pulse of 6  μs duration, the DC cathode experiences a large change in the temperature compared with LaB_{6}, and a change in current density 6 times higher. Validation of the simulation results is performed using experimental data for beam current beyond the gun exit. The experimental data is well reproduced using the simulation method.

  4. Interaction between social influence and payoff transparency.

    Science.gov (United States)

    Zhou, Xinyue; Xie, Wenwen; Ye, Maolin

    2014-02-01

    Social influence and payoff transparency interact with each other to influence decision making. Social influence masks payoff transparency, and lacking transparency drives people to seek social influence. Moreover, our survey supports our claim by showing that social influence and payoff transparency correlate with each other (r(53) = -.71). Bentley et al.'s model can be revised to accommodate the covariance.

  5. Tunable phonon-induced transparency in bilayer graphene nanoribbons.

    Science.gov (United States)

    Yan, Hugen; Low, Tony; Guinea, Francisco; Xia, Fengnian; Avouris, Phaedon

    2014-08-13

    In the phenomenon of plasmon-induced transparency, which is a classical analogue of electromagnetically induced transparency (EIT) in atomic gases, the coherent interference between two plasmon modes results in an optical transparency window in a broad absorption spectrum. With the requirement of contrasting lifetimes, typically one of the plasmon modes involved is a dark mode that has limited coupling to the electromagnetic radiation and possesses relatively longer lifetime. Plasmon-induced transparency not only leads to light transmission at otherwise opaque frequency regions but also results in the slowing of light group velocity and enhanced optical nonlinearity. In this article, we report an analogous behavior, denoted as phonon-induced transparency (PIT), in AB-stacked bilayer graphene nanoribbons. Here, light absorption due to the plasmon excitation is suppressed in a narrow window due to the coupling with the infrared active Γ-point optical phonon, whose function here is similar to that of the dark plasmon mode in the plasmon-induced transparency. We further show that PIT in bilayer graphene is actively tunable by electrostatic gating and estimate a maximum slow light factor of around 500 at the phonon frequency of 1580 cm(-1), based on the measured spectra. Our demonstration opens an avenue for the exploration of few-photon nonlinear optics and slow light in this novel two-dimensional material.

  6. Effect of lanthanum on rooting of in vitro regenerated shoots of Saussurea involucrata Kar. et Kir.

    Science.gov (United States)

    Guo, Bin; Xu, Ling-Ling; Guan, Zhen-Jun; Wei, Ya-Hui

    2012-06-01

    In present study, the effect of lanthanum (La) on the rooting of regenerated shoots of Saussurea involucrata Kar. et Kir was analyzed. Rooting occurred from regenerated shoots inoculated on a medium supplemented with La, the plant rooting hormone indole-3-acetic acid (IAA), or both La and IAA together. The highest rooting efficiency (96%), root number/shoot (8.5), and root length (63 mm) were recorded in shoots cultured on medium containing 2.5 μM IAA combined with 100 μM La(3+). In order to elucidate the mechanism of rooting enhancement by La, we examined dynamic changes in antioxidant enzyme activities in plant tissue over time in culture. We found that the activities of peroxidase (POX) and superoxide dismutase (SOD) were significantly higher in plant tissue cultured in IAA plus La than in La or IAA alone. At the same time, the highest H(2)O(2) content was detected in plant tissue in the presence of 2.5 μM IAA plus 100 μM La(3+). In light of these data and previous results, we speculate that La enhanced IAA-induced rooting by acting as a mild abiotic stress to stimulate POX and SOD activities in plant cells. Then, IAA reacted with oxygen and POX to form the ternary complex enzyme-IAA-O(2) that dissociated into IAA radicals and O(2)(-). Subsequently, IAA-induced O(2)(-) readily converted to hydroxyl radical (HO·) via SOD-catalyzed dismutation. Finally, cell wall loosening and cell elongation occurred as a consequence of HO-dependent scission of wall components, leading to root growth. The treatment of IAA combined with La resulted in the highest plantlet survival (80%) compared to single treatments with IAA or La alone. These data suggest that rare earth elements enhance root morphogenesis and the growth of S. involucrata.

  7. Synthesis and characterization of lanthanum complex (5-choloro-8-hydroxy quinoline) bis (2-2'bipyridine) lanthanum La(Bpy)2(5-Clq)

    Science.gov (United States)

    Kumar, Rahul; Soam, Ankur; Bhargava, Parag

    2017-05-01

    Lanthanum complex, (5-choloro 8-hydroxy quinoline) bis (2-2'bipyridine) has been synthesized and characterized by different techniques. Lanthanum complex, La(Bpy)2(5-Clq) was characterized for structural, thermal and photoluminescence analysis. Structural analysis of this material was done by Fourier transformed infrared spectroscopy (FTIR) and mass spectroscopy. Thermal analysis of this material was done by thermal gravimetric analysis (TGA) and material shows the thermal stability up to 400°C. Absorption and emission spectra of the material was measured by UV-visible spectroscopy and photoluminescence spectroscopy. Solution of this material La(Bpy)2(5-Clq) in ethanol showed absorption peak at 332 nm, which may be attributed due to (π - π*) transitions. The photoluminescence spectra of La(Bpy)2(5-Clq) in ethanol solution showed intense peak at 505 nm.

  8. Greater Transparency Needed

    OpenAIRE

    Angelo Melino; Michael Parkin

    2010-01-01

    Financial market participants would benefit from a better understanding of how the Bank of Canada sets the overnight interest rate in response to economic developments. More accurate forecasts of the Bank’s future policy choices would lead to better financial decisions and better price and wage-setting decisions, making it easier for the Bank to hit its 2 percent inflation target. Currently, the Bank’s internal model predicts a path for the overnight rate that is inconsistent with the expecta...

  9. Optically transparent semiconducting polymer nanonetwork for flexible and transparent electronics

    Science.gov (United States)

    Yu, Kilho; Park, Byoungwook; Kim, Geunjin; Kim, Chang-Hyun; Park, Sungjun; Kim, Jehan; Jung, Suhyun; Jeong, Soyeong; Kwon, Sooncheol; Kang, Hongkyu; Kim, Junghwan; Yoon, Myung-Han; Lee, Kwanghee

    2016-01-01

    Simultaneously achieving high optical transparency and excellent charge mobility in semiconducting polymers has presented a challenge for the application of these materials in future “flexible” and “transparent” electronics (FTEs). Here, by blending only a small amount (∼15 wt %) of a diketopyrrolopyrrole-based semiconducting polymer (DPP2T) into an inert polystyrene (PS) matrix, we introduce a polymer blend system that demonstrates both high field-effect transistor (FET) mobility and excellent optical transparency that approaches 100%. We discover that in a PS matrix, DPP2T forms a web-like, continuously connected nanonetwork that spreads throughout the thin film and provides highly efficient 2D charge pathways through extended intrachain conjugation. The remarkable physical properties achieved using our approach enable us to develop prototype high-performance FTE devices, including colorless all-polymer FET arrays and fully transparent FET-integrated polymer light-emitting diodes. PMID:27911774

  10. Effects of lanthanum and acid rain stress on the bio-sequestration of lanthanum in phytoliths in germinated rice seeds

    Science.gov (United States)

    Si, Yong; Wang, Lihong; Huang, Xiaohua

    2018-01-01

    REEs in the environment can be absorbed by plants and sequestered by plant phytoliths. Acid rain can directly or indirectly affect plant physiological functions. Currently, the effects of REEs and acid rain on phytolith-REEs complex in plants are not yet fully understood. In this study, a high-silicon accumulation crop, rice (Oryza sativa L.), was selected as a representative of plants, and orthogonal experiments were conducted under various levels of lanthanum [La(III)] and pH. The results showed that various La(III) concentrations could significantly improve the efficiency and sequestration of phytolith La(III) in germinated rice seeds. A pH of 4.5 promoted phytolith La(III) sequestration, while a pH of 3.5 inhibited sequestration. Compared with the single treatment with La(III), the combination of La(III) and acid rain inhibited the efficiency and sequestration of phytolith La(III). Correlation analysis showed that the efficiency of phytolith La(III) sequestration had no correlation with the production of phytolith but was closely correlated with the sequestration of phytolith La(III) and the physiological changes of germinated rice seeds. Phytolith morphology was an important factor affecting phytolith La(III) sequestration in germinated rice seeds, and the effect of tubes on sequestration was more significant than that of dumbbells. This study demonstrated that the formation of the phytolith and La(III) complex could be affected by exogenous La(III) and acid rain in germinated rice seeds. PMID:29763463

  11. Structural characterization and properties of lanthanum film as chromate replacement for tinplate

    International Nuclear Information System (INIS)

    Huang Xingqiao; Li Ning

    2007-01-01

    Sulfide-stain resistance of La-passivated, unpassivated and Cr-passivated tinplate was measured using a cysteine tarnish test. Corrosion behavior of these tinplates was investigated using electrochemical impedance spectroscopy (EIS) measurement. The morphology, composition and thickness of lanthanum film were studied by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and X-ray fluorescence spectrometry (XRF), respectively. La-passivation treatment remarkably enhances sulfide-stain resistance of tinplate, and sulfide-stain resistance of La-passivated tinplate is slightly higher than that of Cr-passivated tinplate. La-passivation treatment also significantly improves corrosion protection property of tinplate. In contact with 3.5% NaCl solution, corrosion resistance of La-passivated tinplate is close to that of Cr-passivated tinplate, and in contact with 0.1 M citric-citrate buffer solution, corrosion resistance of La-passivated tinplate is higher than that of Cr-passivated tinplate. Lanthanum film is composed of spherical particles about 50-1000 nm in diameter, while most part of tinplate's surface is covered with the small particles about 50-200 nm. The film mainly consists of lanthanum and oxygen, which mainly exist as La 2 O 3 and its hydrates such as La(OH) 3 and LaOOH. The amount of lanthanum in the film is about 0.0409 g/m 2

  12. PROCESS USING POTASSIUM LANTHANUM SULFATE FOR FORMING A CARRIER PRECIPITATE FOR PLUTONIUM VALUES

    Science.gov (United States)

    Angerman, A.A.

    1958-10-21

    A process is presented for recovering plutonium values in an oxidation state not greater than +4 from fluoride-soluble fission products. The process consists of adding to an aqueous acidic solution of such plutonium values a crystalline potassium lanthanum sulfate precipitate which carries the plutonium values from the solution.

  13. Effects of combined flocculant – Lanthanum modified bentonite treatment on aquatic macroinvertebrate fauna

    NARCIS (Netherlands)

    Waajen, G.; Pauwels, M.; Lürling, M.

    2017-01-01

    A low dose flocculant (FeCl3), combined with lanthanum modified bentonite (LMB) as phosphate-binding agent, has been applied for eutrophication management in Lake De Kuil (The Netherlands). After the treatment, the state of the lake shifted from hypertrophic to mesotrophic. Although

  14. Synthesis and investigation of saturated vapor pressure of lanthanum, praseodymium and neodymium tris-isopropylcyclopentadienyls

    International Nuclear Information System (INIS)

    Devyatykh, G.G.; Chernyaev, N.P.; Zverev, Yu.B.; Gavrishchuk, E.M.; Runovskaya, I.V.; Krupnova, Eh.F.; Chesnokova, S.G.

    1980-01-01

    Lanthanum, praseodymium and neodymium tris-isopropylcyclopentadienyls are synthesized with corresponding unhydrous chlorides in tetrahydrofuran solution. Saturated vapour pressure of substances obtained is studied in the 150-262 deg C range by the statistic method using a compensation zero-manometer. Vapour pressure of the compounds in question is shown to increase with the growth of the rare earth element number [ru

  15. Interfacial layers in tape cast anode-supported doped lanthanum gallate SOFC elements

    Energy Technology Data Exchange (ETDEWEB)

    Maffei, N.; De Silveira, G. [Materials Technology Laboratory, Natural Resources Canada, CANMET, 405 Rochester Street, Ottawa, Ontario (Canada) K1A OG3

    2003-04-01

    Lanthanum gallate doped with strontium and magnesium (LSGM) is a promising electrolyte system for intermediate temperature solid oxide fuel cells (SOFCs). The reported formation of interfacial layers in monolithic type SOFCs based on lanthanum gallate is of concern because of its impact on the performance of the fuel cell. Planar anode-supported SOFC elements (without the cathode) were prepared by the tape casting technique in order to determine the nature of the anode/electrolyte interface after sintering. Two anode systems were studied, one a NiO-CeO{sub 2} cermet, and the other, a modified lanthanum gallate anode containing manganese. Sintering studies were conducted at 1250, 1300, 1350, 1400 and 1450 C to determine the effect of temperature on the interfacial characteristics. Scanning electron microscopy (SEM) revealed a significant diffusion of Ni from the NiO-CeO{sub 2} anode resulting in the formation of an interfacial layer regardless of sintering temperature. Significant La diffusion from the electrolyte into the anode was also observed. In the case of the modified lanthanum gallate anode containing manganese, there was no interfacial layer formation, but a significant diffusion of Mn into the electrolyte was observed.

  16. The air oxidation behavior of lanthanum ion implanted zirconium at 500 deg. C

    CERN Document Server

    Peng, D Q; Chen, X W; Zhou, Q G

    2003-01-01

    The beneficial effect of lanthanum ion implantation on the oxidation behavior of zirconium at 500 deg. C has been studied. Zirconium specimens were implanted by lanthanum ions using a MEVVA source at energy of 40 keV with a fluence range from 1x10 sup 1 sup 6 to 1x10 sup 1 sup 7 ions/cm sup 2 at maximum temperature of 130 deg. C, The weight gain curves were measured after being oxidized in air at 500 deg. C for 100 min, which showed that a significant improvement was achieved in the oxidation behavior of zirconium ion implanted with lanthanum compared with that of the as-received zirconium. The valence of the oxides in the scale was analyzed by X-ray photoemission spectroscopy; and then the depth distributions of the elements in the surface of the samples were obtained by Auger electron spectroscopy. Glancing angle X-ray diffraction at 0.3 deg. incident angles was employed to examine the modification of its phase transformation because of the lanthanum ion implantation in the oxide films. It was obviously fou...

  17. Scanning Auger microscopy study of lanthanum partitioning in sphene-based glass-ceramics

    International Nuclear Information System (INIS)

    Hocking, W.H.; Hayward, P.J.; Watson, D.G.; Allen, G.C.

    1984-01-01

    Glass-ceramics are being investigated as possible hosts for the radioactive wastes that would result from recycling irradiated nuclear fuels. The partitioning of lanthanum in sphene-based glass-ceramics has been studied by scanning Auger electron microscopy for lanthanum concentrations from 0.2 to 2.0 mol.%. Sphene crystals (CaTiSiO 5 ) were located in the silica-rich glass matrix by recording digital Auger images of the calcium and titanium distributions. The sphene crystals were typically 0.5 to 5 μm in size and occupied approximately 40% of the total specimen volume. Auger spot analyses revealed that lanthanum was strongly partitioned into the sphene phase of phosphorus-free glass-ceramics; however, when a small amount of phosphorus was included in the glass-ceramic composition as a crystal nucleating agent, the lanthanum was concentrated in a third minor phase which also contained calcium, phosphorus and oxygen. Chemical shift effects in the Auger spectra of silicon, titanium and phosphorus showed evidence for electron-stimulated desorption of oxygen. (author)

  18. Synthesis and Characterization of Lanthanum Complexes with Amino Acid Schiff Base

    Institute of Scientific and Technical Information of China (English)

    张秀英; 张有娟; 杨林

    2001-01-01

    Six new complexes of lanthanum with amino acid Schiff base ligands, A-F, were prepared in methanol-aqueous solution. The composition and properties of the title complexes were characterized by elemental analysis, molar conductance, infrared, electronic spectra, 1H NMR, thermogravimetric and differential thermal analysis.

  19. Effect of lanthanum substitution on dielectric relaxation, impedance response, conducting and magnetic properties of strontium hexaferrite

    Energy Technology Data Exchange (ETDEWEB)

    Want, Basharat, E-mail: bawant@kashmiruniversity.ac.in; Bhat, Bilal Hamid; Ahmad, Bhat Zahoor

    2015-04-05

    Highlights: • The substitution of La affects the dielectric and magnetic properties of strontium hexaferrite. • The electric behaviour of the compound follows the Koop’s phenomenological theory. • The impedance study shows the role of grain boundaries to the electric properties of the compound. • The substitution of La to strontium hexaferrite reduces the resistive nature of grain boundaries. - Abstract: Lanthanum strontium hexaferrite Sr{sub 1−x}La{sub x}Fe{sub 12}O{sub 19} (x = 0, 0.08, 0.13 , 0.18) has been successfully synthesized by using citrate-precursor method and characterized by different techniques. The X-ray diffraction results revealed that the sample is crystalline in nature and is of single phase with the space group P63/mmc. The dielectric, conducting and impedance related studies have been carried out as a function of frequency and concentration of lanthanum in the frequency ranges of 20 Hz–3 MHz. Impedance studies were performed in the frequency domain to distinguish between bulk and grain boundary contributions of the material to the overall dielectric response. The electric response of the material was also modeled by an equivalent circuit and different circuit parameters were calculated. Magnetic characterization of the material was also performed and the effect of lanthanum concentration was studied. The hysteresis loop obtained from the magnetometer showed that with the increase of lanthanum concentration, the saturation magnetisation decreases while as coercivity increases.

  20. Hydrocarbon conversion with cracking catalyst having co-combustion promoters lanthanum and iron

    International Nuclear Information System (INIS)

    Csicsery, S.M.

    1979-01-01

    A composition useful in hydrocarbon conversion processes such as catalytic cracking comprises 0.05 to 10 weight percent lanthanum associated with a refractory support. The composition may also include 0.02 to 10 weight percent iron. The refractory support is a zeolitic crystalline aluminosilicate

  1. In situ XANES cell used for the study of lanthanum strontium cuprate deNOx catalysts

    DEFF Research Database (Denmark)

    Hagen, Anke

    2011-01-01

    , maintaining charge neutrality, with the concentration of oxygen vacancies likely increasing at substitution ratios larger than Sr/La>0.08. During heating in air, the valence of copper ions in the structure increased. Upon exposure to NO at 500 °C the valence of copper ions in a lanthanum strontium cuprate...

  2. Thermoelectric power and electrical conductivity of strontium-doped lanthanum manganite

    DEFF Research Database (Denmark)

    Ahlgren, E.O.; Poulsen, F.W.

    1996-01-01

    Thermoelectric power and electrical conductivity of pure and 5, 10 and 20% strontium-doped lanthanum manganite are determined as function of temperature in air and of P-O2 at 1000 degrees C. At high temperatures the thermoelectric power is negative. Both thermoelectric power and conductivity...

  3. Energetically benign synthesis of lanthanum silicate through “silica garden” route and its characterization

    International Nuclear Information System (INIS)

    Parmar, Kavita; Bhattacharjee, Santanu

    2017-01-01

    Lanthanum silicate synthesis through “silica garden” route has been reported as an alternative to energy intensive milling procedure. Under optimum conditions lanthanum chloride crystals react with water glass (sodium silicate) to produce self generating hollow lanthanum silicate precipitation tube(s) (LaSPT). The micro tubes are irregular, thick, white coloured and amorphous but are hierarchically built from smaller tubules of 10–20 nm diameters. They retain their amorphous nature on being heated up to 600 °C beyond which crystallization starts. The major phase in the LaSPT heated at 900 °C is La_2Si_2O_7. “As synthesized” LaSPT is heterogeneous and comprises non stoichiometric phases. The exterior and interior surfaces of these tubes are remarkably different in their morphology and chemical composition. LaSPT sintered at 1200 and 1300 °C show fair amount of ionic conductivity. - Graphical abstract: Lanthanum silicate precipitation tube (LaSPT) produced through ‘silica garden’ route offers a green alternative to energy intensive milling procedure. - Highlights: • La-silicate precipitation tube (LaSPT) synthesized via silica garden route. • The microtubes are irregular, thick, white coloured and amorphous. • They are hierarchically built from smaller tubules of 10–20 nm diameters. • The major phase in the LaSPT heated at 900 °C is La_2Si_2O_7. • LaSPT sintered at 1200 °C is fairly conducting.

  4. The oxidation of carbon monoxide over transition metal doped lanthanum manganates nanoparticles

    International Nuclear Information System (INIS)

    Fal Desai, M.S.; Salker, A.V.

    2012-01-01

    Lanthanum manganates perovskites (ABO 3 ) has been widely studied and applied. Many perovskites with A and B sites doped with different metals show good catalytic activity in many oxidation reactions than the individual perovskite. In present study, an attempt has been made to show comparative account of CO oxidation by doping the B site with different cations using sol-gel method

  5. Transparent Memory For Harsh Electronics

    KAUST Repository

    Ho, C. H.

    2017-03-14

    As a new class of non-volatile memory, resistive random access memory (RRAM) offers not only superior electronic characteristics, but also advanced functionalities, such as transparency and radiation hardness. However, the environmental tolerance of RRAM is material-dependent, and therefore the materials used must be chosen carefully in order to avoid instabilities and performance degradation caused by the detrimental effects arising from environmental gases and ionizing radiation. In this work, we demonstrate that AlN-based RRAM displays excellent performance and environmental stability, with no significant degradation to the resistance ratio over a 100-cycle endurance test. Moreover, transparent RRAM (TRRAM) based on AlN also performs reliably under four different harsh environmental conditions and 2 MeV proton irradiation fluences, ranging from 1011 to 1015 cm-2. These findings not only provide a guideline for TRRAM design, but also demonstrate the promising applicability of AlN TRRAM for future transparent harsh electronics.

  6. Issues in Canadian board transparency

    Directory of Open Access Journals (Sweden)

    Chris Bart

    2007-01-01

    Full Text Available Transparency is considered one of the principles of good corporate governance. But what does it mean – in practice – especially when it comes to Board transparency – i.e. the ability of shareholders to gain knowledge about an organization’s corporate governance practices in order to make an informed assessment of Directors’ individual and collective roles and performance. In a preliminary investigation of Board transparency practices in Canadian listed firms (using data from 2003-2004, it was found that there were wide variations in the nature and quantity of corporate governance practices disclosed. The reasons for these variations are discussed and a number of recommendations for improved disclosure are presented.

  7. Transparency of nuclear regulatory activities

    International Nuclear Information System (INIS)

    2007-01-01

    One of the main missions of nuclear regulators is to protect the public, and this cannot be completely achieved without public confidence. The more a regulatory process is transparent, the more such confidence will grow. Despite important cultural differences across countries, a number of common features characterise media and public expectations regarding any activity with an associated risk. A common understanding of transparency and main stakeholders' expectations in the field of nuclear safety were identified during this workshop, together with a number of conditions and practices aimed at improving the transparency of nuclear regulatory activities. These conditions and practices are described herein, and will be of particular interest to all those working in the nuclear regulatory field. Their implementation may, however, differ from one country to another depending on national context. (authors)

  8. Effects of transparency on the perceived trustworthiness of a government organization : Evidence from an online experiment

    NARCIS (Netherlands)

    Grimmelikhuijsen, Stephan G.; Meijer, Albert J.

    2014-01-01

    Although the effect of government transparency on trust is heavily debated, our theoretical and empirical understanding of this relationship is still limited. The basic assumption tested in this article is whether transparency leads to higher levels of perceived trustworthiness. This article uses

  9. Transparent solar cell window module

    Energy Technology Data Exchange (ETDEWEB)

    Chau, Joseph Lik Hang; Chen, Ruei-Tang; Hwang, Gan-Lin; Tsai, Ping-Yuan [Nanopowder and Thin Film Technology Center, ITRI South, Industrial Technology Research Institute, Tainan County 709 (China); Lin, Chien-Chu [I-Lai Acrylic Corporation, Tainan City (China)

    2010-03-15

    A transparent solar cell window module based on the integration of traditional silicon solar cells and organic-inorganic nanocomposite material was designed and fabricated. The transparent solar cell window module was composed of a nanocomposite light-guide plate and traditional silicon solar cells. The preparation of the nanocomposite light-guide plate is easy without modification of the traditional casting process, the nanoparticles sol can be added directly to the polymethyl methacrylate (PMMA) monomer syrup during the process. The solar energy collected by this window can be used to power up small household electrical appliances. (author)

  10. Does doxastic transparency support evidentialism?

    DEFF Research Database (Denmark)

    Steglich-Petersen, Asbjørn

    2008-01-01

    Nishi Shah has recently argued that transparency in doxastic deliberation supports a strict version of evidentialism about epistemic reasons. I argue that Shah’s argument relies on a principle that is incompatible the strict version of evidentialism Shah wishes to advocate.......Nishi Shah has recently argued that transparency in doxastic deliberation supports a strict version of evidentialism about epistemic reasons. I argue that Shah’s argument relies on a principle that is incompatible the strict version of evidentialism Shah wishes to advocate....

  11. Color transparency: Enchantment and effort

    International Nuclear Information System (INIS)

    Miller, G.A.

    1991-01-01

    A quantum mechanical approach is used to study high momentum transfer reactions in which a nucleon is knocked out of the nucleus. We show that the nuclear interactions of the wave packet produced in such a process tend to cancel, so that the nuclear medium becomes transparent. The wave packet (ejectile)-nucleon interactions, including the production of nucleon resonances are also discussed. Color transparency effects in the (e,e'p) reaction may be significant at relatively low momentum transfer Q 2 = 3 - 6 (GeV 2 /c) 2 . 17 refs., 3 figs

  12. Measuring nuclear transparency from exclusive vector meson production in lepton-nucleus scattering

    Energy Technology Data Exchange (ETDEWEB)

    Fang, G.Y. [Harvard Univ., Cambridge, MA (United States)

    1994-04-01

    Preliminary results on the measurement of nuclear transparencies from exclusive {rho}{sup 0} meson production from E665 at Fermilab are reported. The data were collected on hydrogen, deuterium, carbon, calcium, and lead targets with a mean beam energy of 470 GeV. Increases in the transparencies are observed in both coherent and incoherent production channels as the virtuality of the photon increases, as expected of color transparency. Ideas of systematic studies of color transparency in exclusive vector meson production at CEBAF are discussed.

  13. Measuring nuclear transparency from exclusive vector meson production in lepton-nucleus scattering

    International Nuclear Information System (INIS)

    Fang, G.Y.

    1994-01-01

    Preliminary results on the measurement of nuclear transparencies from exclusive ρ 0 meson production from E665 at Fermilab are reported. The data were collected on hydrogen, deuterium, carbon, calcium, and lead targets with a mean beam energy of 470 GeV. Increases in the transparencies are observed in both coherent and incoherent production channels as the virtuality of the photon increases, as expected of color transparency. Ideas of systematic studies of color transparency in exclusive vector meson production at CEBAF are discussed

  14. A FRAMEWORK FOR TRANSPARENCY IN INTERNATIONAL TRADE

    Directory of Open Access Journals (Sweden)

    Bernal Turnes, Paloma

    2015-01-01

    Full Text Available The aim of this paper is to cover the gap in literature about transparency in the context of international trade facilitation. It focuses on the importance of transparency in achieving growth in international trade and the differences between non-transparent practices and corruption in global trade. Managing the disclosure of information about rules, regulations and laws is not the only trade policy instrument where transparency becomes important. To build a framework on levels of transparency we developed a matrix classifying the transparency of each country based on ease of doing business and levels of bribery. Four different strategies are explained based on the different scenarios of transparency in international trade. The main conclusions reflect that disclosure of information is not enough to guarantee transparency and monitoring of transparency must be improved.

  15. Textile Dye Removal from Aqueous Solution using Modified Graphite Waste/Lanthanum/Chitosan Composite

    Science.gov (United States)

    Kusrini, E.; Wicaksono, B.; Yulizar, Y.; Prasetyanto, EA; Gunawan, C.

    2018-03-01

    We investigated various pre-treatment processes of graphite waste using thermal, mechanical and chemical methods. The aim of this work is to study the performance of modified graphite waste/lanthanum/chitosan composite (MG) as adsorbent for textile dye removal from aqueous solution. Effect of graphite waste resources, adsorbent size and lanthanum concentration on the dye removal were studied in batch experiments. Selectivity of MG was also investigated. Pre-heated graphite waste (NMG) was conducted at 80°C for 1 h, followed by mechanical crushing of the resultant graphite to 75 μm particle size, giving adsorption performance of ˜58%, ˜67%, ˜93% and ˜98% of the model dye rhodamine B (concentration determined by UV-vis spectroscopy at 554 nm), methyl orange (464 nm), methylene blue (664 nm) and methyl violet (580 nm), respectively from aqueous solution. For this process, the system required less than ˜5 min for adsorbent material to be completely saturated with the adsorbate. Further chemical modification of the pre-treated graphite waste (MG) with lanthanum (0.01 – V 0.03 M) and chitosan (0.5% w/w) did not improve the performance of dye adsorption. Under comparable experimental conditions, as those of the ‘thermal-mechanical-pre-treated-only’ (NMG), modification of graphite waste (MG) with 0.03 M lanthanum and 0.5% w/w chitosan resulted in ˜14%, ˜47%, ˜72% and ˜85% adsorption of rhodamine B, methyl orange, methylene blue and methyl violet, respectively. Selective adsorption of methylene blue at most to ˜79%, followed by methyl orange, methyl violet and rhodamine B with adsorption efficiency ˜67, ˜38, and ˜9% sequentially using MG with 0.03 M lanthanum and 0.5% w/w chitosan.

  16. Effects of lanthanum exposure on elemental distribution in rat brains measured by synchrotron radiation XRF

    International Nuclear Information System (INIS)

    Feng Liuxing; Xiao Haiqing; He Xiao; Liu Nianqing; Zhao Yuliang; Chai Zhifang; Zhang Zhiyong

    2005-01-01

    Rare earth elements (REEs) comprise a coherent series of 15 elements from lanthanum to lutetium and possessing very similar chemical properties. In recent decades, with the rapid increase of the exploitation of REE resources and their applications to modern industry and daily life, particularly to agriculture as fertilizer additives in China, more and more REEs are coming into environmental system as well as food chain through various ways. It has become increasingly important to obtain more information on the physiological function of REEs and their long-term biological effects on body of living beings. Epidemiological investigations found that the intelligence quotients (IQ) of children from the REE-high background regions are obviously different from that of the normal region. This indicated that REEs probably affect the function of brain. However, the mechanism is totally unknown. The contents and distributions of major and trace elements are sometimes good indicators of the physiological and pathological conditions of human and animal brains In this study, the effects of subchronic lanthanum exposure on the elemental distribution in the rat brains were studied. Wistar rats were exposed to lanthanum chloride through oral administration at O, 0.1, 2, and 40-mg/kg doses for 6 months. The elements such as Cl, K, Ca, Fe, Cu, and Zn in brain slices were identified by synchrotron radiation X-ray fluorescence analysis. Differences in two-dimensional maps of elemental distribution were noticed. Cl, Ca, and Zn were primarily concentrated in hippocampus of the controls. With the increase of the lanthanum dosage, the Ca and Zn levels were significantly decreased, while the Cu levels were significantly elevated in cortex, hippocampus and thalamus. Our results suggest that subchronic lanthanum exposure in rats appears to change elemental distribution in brain. The impact of lanthanides on brain function is not negligible.

  17. Transparency in decision-making processes governing hazardous activities

    DEFF Research Database (Denmark)

    Rasmussen, B.; Jensen, K.K.; Sandøe, P.

    2007-01-01

    Transparent decisions are decisions in which the decision maker clearly presents to others the normative and factual premises behind the conclusions and explains the reasoning leading from these premises to the conclusion. Transparency thus involves uncovering, describing, documenting...... and communicating all the argumentative steps in the line of reasoning. It also involves acknowledging the weighting of any evidence drawn upon in reaching the final decision. It is recommended that each decision should be accompanied by an audit trail describing the premises justifying it. Uncertainties should...

  18. Effect of preparation technique of hydrated zirconium(4) dioxide on sorption of microimpurities of nonferrous metals, iron(3) and thorium(4) from lanthanum(3) nitrate solutions

    International Nuclear Information System (INIS)

    Bekrenev, A.V.; Pyartman, A.K.; Belousov, E.A.

    1989-01-01

    A study was made on the effect of peculiarities of hydrated zirconium(4) dioxide (HZD) synthesis on reproducibility of its sorption properties. It is shown that change of zirconium(4) concentration in basic solution within the limits of 0-1.0 mol/dm 3 its HCl acidity from 0 up to 1.0 mol/dm 3 concentration of NaOH solution used for HZD precipitation within the limits of 1.0-10.0 mol/dm 3 the final pH value of HZD gel from 10 up to 14 affects slightly the impurity element sorption from lanthanum nitrate solution. Freezing of HZD leads to increase of capacity and decrease of selectivity of sorbent samples with respect to impurity ions (Ni 2+ , Co 2+ , Bi 3+ , Fe 3+ , Th 4+ ); increase of the time of gel ripening leads to decrease of capacity and growth of selectivity

  19. Why is Transparency Greenland Necessary?

    DEFF Research Database (Denmark)

    Jensen, Boris Brorman

    2012-01-01

    Greenland is facing significant changes in the composition of its economy, and is moving rapidly in the direction of becoming a commodities economy. Studies conducted by Transparency International in other parts of the world suggest that oil exploration and mining are among the areas of economic...

  20. Transparency in Cooperative Online Education

    Science.gov (United States)

    Dalsgaard, Christian; Paulsen, Morten Flate

    2009-01-01

    The purpose of this article is to discuss the following question: What is the potential of social networking within cooperative online education? Social networking does not necessarily involve communication, dialogue, or collaboration. Instead, the authors argue that "transparency" is a unique feature of social networking services.…

  1. Transparent ceramic lamp envelope materials

    Energy Technology Data Exchange (ETDEWEB)

    Wei, G C [OSRAM SYLVANIA, 71 Cherry Hill Drive, Beverly, MA 01915 (United States)

    2005-09-07

    Transparent ceramic materials with optical qualities comparable to single crystals of similar compositions have been developed in recent years, as a result of the improved understanding of powder-processing-fabrication- sintering-property inter-relationships. These high-temperature materials with a range of thermal and mechanical properties are candidate envelopes for focused-beam, short-arc lamps containing various fills operating at temperatures higher than quartz. This paper reviews the composition, structure and properties of transparent ceramic lamp envelope materials including sapphire, small-grained polycrystalline alumina, aluminium oxynitride, yttrium aluminate garnet, magnesium aluminate spinel and yttria-lanthana. A satisfactory thermal shock resistance is required for the ceramic tube to withstand the rapid heating and cooling cycles encountered in lamps. Thermophysical properties, along with the geometry, size and thickness of a transparent ceramic tube, are important parameters in the assessment of its resistance to fracture arising from thermal stresses in lamps during service. The corrosive nature of lamp-fill liquid and vapour at high temperatures requires that all lamp components be carefully chosen to meet the target life. The wide range of new transparent ceramics represents flexibility in pushing the limit of envelope materials for improved beamer lamps.

  2. Camuflagem e transparência

    Directory of Open Access Journals (Sweden)

    Maria de Fátima de A. Silveira

    2000-06-01

    Full Text Available O ensaio estabelece, a partir da compreensão de ELIADE, analogias entre alguns símbolos universais e os rituais de morte desenvolvidos pela Enfermagem, desnudando a camuflagem ali existente e apontando sua transparência como forma de enriquecer a prática profissional, beneficiando cuidadora(es e sujeitos do cuidado.

  3. Camuflagem e transparência

    Directory of Open Access Journals (Sweden)

    Maria de Fátima de A. Silveira

    Full Text Available O ensaio estabelece, a partir da compreensão de ELIADE, analogias entre alguns símbolos universais e os rituais de morte desenvolvidos pela Enfermagem, desnudando a camuflagem ali existente e apontando sua transparência como forma de enriquecer a prática profissional, beneficiando cuidadora(es e sujeitos do cuidado.

  4. Nuclear waste repository transparency technology test bed demonstrations at WIPP

    International Nuclear Information System (INIS)

    Betsill J, David; Elkins, Ned Z.; Wu, Chuan-Fu; Mewhinney, James D.; Aamodt, Paul

    2000-01-01

    repository, the Waste Isolation Pilot Plant (WIPP) offers a unique opportunity to serve as an international cooperative test bed for developing and demonstrating technologies and processes in a fully operational repository system setting. To address the substantial national security implications for the US resulting from the lack of integrated, transparent management and disposition of nuclear materials at the back-end of the nuclear fuel and weapons cycles, it is proposed that WIPP be used as a test bed to develop and demonstrate technologies that will enable the transparent and proliferation-resistant geologic isolation of nuclear materials. The objectives of this initiative are to: (1) enhance public confidence in safe, secure geologic isolation of nuclear materials; (2) develop, test, and demonstrate transparency measures and technologies for the back-end of nuclear fuel cycle; and (3) foster international collaborations leading to workable, effective, globally-accepted standards for the transparent monitoring of geological repositories for nuclear materials. Test-bed activities include: development and testing of monitoring measures and technologies; international demonstration experiments; transparency workshops; visiting scientist exchanges; and educational outreach. These activities are proposed to be managed by the Department of Energy/Carlsbad Area Office (DOE/CAO) as part of The Center for Applied Repository and Underground Studies (CARUS)

  5. Legal framework to ensure transparency

    International Nuclear Information System (INIS)

    Treier, A.

    2007-01-01

    There is a national and an international trend towards administrative transparency. This trend has not stopped at. the Swiss border. Some cantons of Switzerland have already introduced the transparency principle at the cantonal level. At the federal level, the Swiss Confederation introduced on 1 July 2006 the new Federal 'Freedom of Information Act'. Also the Swiss Federal Nuclear Safety Inspectorate (I-ISK) falls under this rule. Before introduction of this law on transparency. most of the documents of Swiss federal Administration were treated as confidential. Access rights to official documents were granted only on certain conditions and in special cases. But there is a general interest, that the public should have the possibility to ask to look at the files of the administration. Since years, the administration had no longer been able to hide behind secretiveness. For instance, the introduction of Internet brought a lot of transparency. The administration had to explain what sort of job it is actually doing and how it is doing. Also, the media were and are increasing their research for information. In this context, the new law on transparency ('Freedom of Information Act') is rather an evolution than a revolution. The Freedom of Information Act guarantees the public access to official documents. Most of the documents of the Federal Administration are public. This access can be limited, differentiated or refused in certain cases. That means that the principle of proportionality between private interests and public transparency has to be applied. The real challenge for the authority is the trade off between the public's right to access information and the industrial legitimate efforts to protect industrial and trade secrets. In the nuclear field, the international principle of transparency has also become an important national principle for Switzerland and FISK. The Swiss Nuclear Energy Act says that 'The relevant authorities shall regularly inform the general

  6. High-temperature, Knudsen cell-mass spectroscopic studies on lanthanum oxide/uranium dioxide solid solutions

    International Nuclear Information System (INIS)

    Sunder, S.; McEachern, R.; LeBlanc, J.C.

    2001-01-01

    Knudsen cell-mass spectroscopic experiments were carried out with lanthanum oxide/uranium oxide solid solutions (1%, 2% and 5% (metal at.% basis)) to assess the volatilization characteristics of rare earths present in irradiated nuclear fuel. The oxidation state of each sample used was conditioned to the 'uranium dioxide stage' by heating in the Knudsen cell under an atmosphere of 10% CO 2 in CO. The mass spectra were analyzed to obtain the vapour pressures of the lanthanum and uranium species. It was found that the vapour pressure of lanthanum oxide follows Henry's law, i.e., its value is directly proportional to its concentration in the solid phase. Also, the vapour pressure of lanthanum oxide over the solid solution, after correction for its concentration in the solid phase, is similar to that of uranium dioxide. (authors)

  7. The study of interaction of lanthanum-, cerium- and neodymium chlorides with sodium borohydride in pyridine- and tetrahydrofuran medium

    International Nuclear Information System (INIS)

    Mirsaidov, U.; Rotenberg, T.G.; Dymova, T.N.

    1976-01-01

    Bis-tetrahydrofurans of lanthanum and neodymium borohydrides and bis-pyridinates of lanthanum, cerium and neodymium borohydrides were obtained by interacting sodium borohydride with lanthanum-, cerium and neodymium chlorides in pyridine and tetrahydrofuran media. All operations involving reagent combination, sampling and phase separation are performed in inert atmosphere using argonvacuum equipment. The reaction in pyridine was virtually instantaneous and accompanied by flocculanet precipitation. The interaction of lanthanum chloride and neodymium chloride with sodium borohydride in tetrahydrofuran (THF) was a slow (23-30 hr) heterophase process. The interaction rate was affected by size reduction of the intial substances, temperature, reagent proportion and mixing rate. The reaction time was twice reduced with boiling tetrahydrofuran

  8. Transparency of magnetized plasma at the cyclotron frequency

    International Nuclear Information System (INIS)

    Shvets, G.; Wurtele, J.S.

    2002-01-01

    Electromagnetic radiation is strongly absorbed by a magnetized plasma if the radiation frequency equals the cyclotron frequency of plasma electrons. It is demonstrated that absorption can be completely canceled in the presence of a magnetostatic field of an undulator, or a second radiation beam, resulting in plasma transparency at the cyclotron frequency. This effect is reminiscent of the electromagnetically induced transparency (EIT) of three-level atomic systems, except that it occurs in a completely classical plasma. Unlike the atomic systems, where all the excited levels required for EIT exist in each atom, this classical EIT requires the excitation of nonlocal plasma oscillation. A Lagrangian description was used to elucidate the physics of the plasma transparency and control of group and phase velocity. This control leads to applications for electromagnetic pulse compression and electron/ion acceleration

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

    International Nuclear Information System (INIS)

    Luiz, J.M.

    1989-01-01

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

  10. Double transparent conducting layers for Si photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Ju-Hyung [Department of Electrical Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260 (United States); Kim, Joondong, E-mail: joonkim@incheon.ac.kr [Department of Electrical Engineering, Incheon National University, Incheon, 406772 (Korea, Republic of); Park, Yun Chang [Measurement and Analysis Division, National Nanofab Center (NNFC), Daejeon 305806 (Korea, Republic of); Moon, Sang-Jin [Energy Materials Research Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon 305-600 (Korea, Republic of); Anderson, Wayne A. [Department of Electrical Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260 (United States)

    2013-11-29

    Double transparent conductive oxide (TCO) film-embedded Si heterojunction solar cells were fabricated. An intentional doping was not applied for heterojunction solar cells due to the spontaneous Schottky junction formation between TCO films and an n-type Si substrate. Three different TCO coatings were formed by sputtering method for an Al-doped ZnO (AZO) film, an indium-tin-oxide (ITO) film and double stacks of ITO/AZO films. An improved crystalline ITO film was grown on an AZO template upon hetero-epitaxial growth. This double TCO films-embedded Si (ITO/AZO/Si) heterojunction solar cell provided significantly enhanced efficiency of 9.23 % as compared to the single TCO/Si (ITO/Si or AZO/Si) devices due to the optical and the electrical benefits. The effective arrangement of TCO films (ITO/AZO) provides benefits of a lower front contact resistance and a smaller band offset to Si leading enhanced photovoltaic performances. This demonstrates a potential scheme for an effective TCO film-embedded heterojunction Si solar cell. - Highlights: • Double transparent conducting oxide films form a heterojunction to Si. • A quality indium-tin-oxide film was grown above an Al-doped zinc oxide template. • Heterojunction Si solar cell was made without an intentional doping process.

  11. Double transparent conducting layers for Si photovoltaics

    International Nuclear Information System (INIS)

    Yun, Ju-Hyung; Kim, Joondong; Park, Yun Chang; Moon, Sang-Jin; Anderson, Wayne A.

    2013-01-01

    Double transparent conductive oxide (TCO) film-embedded Si heterojunction solar cells were fabricated. An intentional doping was not applied for heterojunction solar cells due to the spontaneous Schottky junction formation between TCO films and an n-type Si substrate. Three different TCO coatings were formed by sputtering method for an Al-doped ZnO (AZO) film, an indium-tin-oxide (ITO) film and double stacks of ITO/AZO films. An improved crystalline ITO film was grown on an AZO template upon hetero-epitaxial growth. This double TCO films-embedded Si (ITO/AZO/Si) heterojunction solar cell provided significantly enhanced efficiency of 9.23 % as compared to the single TCO/Si (ITO/Si or AZO/Si) devices due to the optical and the electrical benefits. The effective arrangement of TCO films (ITO/AZO) provides benefits of a lower front contact resistance and a smaller band offset to Si leading enhanced photovoltaic performances. This demonstrates a potential scheme for an effective TCO film-embedded heterojunction Si solar cell. - Highlights: • Double transparent conducting oxide films form a heterojunction to Si. • A quality indium-tin-oxide film was grown above an Al-doped zinc oxide template. • Heterojunction Si solar cell was made without an intentional doping process

  12. Outside finance, dominant investors and strategic transparency

    NARCIS (Netherlands)

    Perotti, E.C.; von Thadden, E.-L.

    2000-01-01

    This paper studies optimal financial contracts and product market competition under a strategic transparency decision. When firms seeking outside finance resort to actively monitored debt in order to commit against opportunistic behaviour, the dominant lender can influence corporate transparency.

  13. Categories and Dimensions of Organizational Transparency

    DEFF Research Database (Denmark)

    Albu, Oana Brindusa; Flyverbom, Mikkel

    Transparency is a distinctive area of research across disciplines and presents significant importance for organization studies. However, transparency is rarely subject to structured and critical scrutiny and as a result its relevance for organizational analysis is underestimated. In an attempt...... to foreground the value of transparency studies, we offer an overview of the existing research and indicate two paradigmatic positions underpinning the transparency literature, namely what we term non-performative and performative approaches. The main contribution of the paper lies in this ground......, an approach which remains underexplored. Finally, we discuss some avenues for future studies of the organizing properties of transparency: the secrecy-transparency interplay, the power-transparency nexus and the transparency ‘family tree’ (i.e., intersections between multiple forms of disclosure)....

  14. Microwave-assisted synthesis of lanthanum conversion coating on Mg-Li alloy and its corrosion resistance

    International Nuclear Information System (INIS)

    Song Dalei; Jing Xiaoyan; Wang Jun; Lu Shanshan; Yang Piaoping; Wang Yanli; Zhang Milin

    2011-01-01

    Graphical abstract: Highlights: → The method of microwave is used to synthesize lanthanum conversion coating. → Lanthanum conversion coating on Mg-Li alloy was studied. → Different conditions between room temperature and microwave were compared. → The corrosion behavior of lanthanum conversion coatings was studied. → The corrosion mechanism of lanthanum conversion coatings was studied. - Abstract: Lanthanum-based conversion coating on Mg-Li alloy has been prepared by a microwave-assisted method. X-ray diffractions (XRD) indicate that the intermetallic compounds of lanthanum are formed on Mg-Li alloy surface. Scanning electron microscopy (SEM) images show that the coating has different morphologies and special structures. The corrosion resistance was assessed by means of potentiodynamic polarization curves and electrochemical impedance spectra (EIS). The results indicate that this coating significantly reduces the corrosion rate of Mg-Li alloy in NaCl solution. A comparing experiment indicates that the coating prepared by microwave-assisted process has superior corrosion resistance to the coating obtained at room temperature.

  15. XPS characterisation of in situ treated lanthanum oxide and hydroxide using tailored charge referencing and peak fitting procedures

    International Nuclear Information System (INIS)

    Sunding, M.F.; Hadidi, K.; Diplas, S.; Lovvik, O.M.; Norby, T.E.; Gunnaes, A.E.

    2011-01-01

    Highlights: → Gold particles deposited in vacuum as energy reference for insulating samples in XPS. → Separation of La 3d and MNN peaks in XP spectra acquired with Al Kα radiation. → We describe the spectral differences between lanthanum oxide and lanthanum hydroxide. → A doublet in O 1s of La 2 O 3 is ascribed to two distinct oxygen sites in the crystal. - Abstract: A technique is described for deposition of gold nanoparticles under vacuum, enabling consistent energy referencing of X-ray photoelectron spectra obtained from lanthanum hydroxide La(OH) 3 and in situ treated lanthanum oxide La 2 O 3 powders. A method is also presented for the separation of the overlapping lanthanum 3d and MNN peaks in X-ray photoelectron spectra acquired with Al Kα radiation. The lower satellite intensity in La(OH) 3 compared to La 2 O 3 is related to the higher ionicity of the La-O bond in the former compared to the latter compound. The presence of an additional peak in the valence band spectrum of the hydroxide compared to the oxide is attributed to the O-H bond as indicated by density functional theory based calculations. A doublet in the O 1s peak of lanthanum oxide is associated to the presence of two distinct oxygen sites in the crystal structure of this compound.

  16. XPS characterisation of in situ treated lanthanum oxide and hydroxide using tailored charge referencing and peak fitting procedures

    Energy Technology Data Exchange (ETDEWEB)

    Sunding, M.F., E-mail: m.f.sunding@fys.uio.no [Department of Physics, University of Oslo, P.O. Box 1048 Blindern, NO-0316 Oslo (Norway); Hadidi, K. [Department of Physics, University of Oslo, P.O. Box 1048 Blindern, NO-0316 Oslo (Norway); Diplas, S. [Department of Chemistry and Centre for Material Science and Nanotechnology (SMN), University of Oslo, P.O. Box 1033 Blindern, NO-0315 Oslo (Norway); SINTEF Materials and Chemistry, P.O. Box 124 Blindern, NO-0314 Oslo (Norway); Lovvik, O.M. [Department of Physics, University of Oslo, P.O. Box 1048 Blindern, NO-0316 Oslo (Norway); SINTEF Materials and Chemistry, P.O. Box 124 Blindern, NO-0314 Oslo (Norway); Norby, T.E. [Department of Chemistry and Centre for Material Science and Nanotechnology (SMN), University of Oslo, P.O. Box 1033 Blindern, NO-0315 Oslo (Norway); Gunnaes, A.E. [Department of Physics, University of Oslo, P.O. Box 1048 Blindern, NO-0316 Oslo (Norway)

    2011-07-15

    Highlights: {yields} Gold particles deposited in vacuum as energy reference for insulating samples in XPS. {yields} Separation of La 3d and MNN peaks in XP spectra acquired with Al K{alpha} radiation. {yields} We describe the spectral differences between lanthanum oxide and lanthanum hydroxide. {yields} A doublet in O 1s of La{sub 2}O{sub 3} is ascribed to two distinct oxygen sites in the crystal. - Abstract: A technique is described for deposition of gold nanoparticles under vacuum, enabling consistent energy referencing of X-ray photoelectron spectra obtained from lanthanum hydroxide La(OH){sub 3} and in situ treated lanthanum oxide La{sub 2}O{sub 3} powders. A method is also presented for the separation of the overlapping lanthanum 3d and MNN peaks in X-ray photoelectron spectra acquired with Al K{alpha} radiation. The lower satellite intensity in La(OH){sub 3} compared to La{sub 2}O{sub 3} is related to the higher ionicity of the La-O bond in the former compared to the latter compound. The presence of an additional peak in the valence band spectrum of the hydroxide compared to the oxide is attributed to the O-H bond as indicated by density functional theory based calculations. A doublet in the O 1s peak of lanthanum oxide is associated to the presence of two distinct oxygen sites in the crystal structure of this compound.

  17. Second-order nonlinearity induced transparency.

    Science.gov (United States)

    Zhou, Y H; Zhang, S S; Shen, H Z; Yi, X X

    2017-04-01

    In analogy to electromagnetically induced transparency, optomechanically induced transparency was proposed recently in [Science330, 1520 (2010)SCIEAS0036-807510.1126/science.1195596]. In this Letter, we demonstrate another form of induced transparency enabled by second-order nonlinearity. A practical application of the second-order nonlinearity induced transparency is to measure the second-order nonlinear coefficient. Our scheme might find applications in quantum optics and quantum information processing.

  18. Playing the numbers game: Dealing with transparency

    NARCIS (Netherlands)

    Pachidi, S.; Huysman, M.H.; Berends, Hans; van de Weerd, G.C.

    2015-01-01

    Our research focus is on unpacking the performativity of transparency in order to explain how digital technologies, formerly perceived as enablers of surveillance and control, afford opaqueness as much as transparency. We develop a sociomaterial perspective on transparency and investigate how

  19. Organizational Transparency as Myth and Metaphor

    DEFF Research Database (Denmark)

    Christensen, Lars Thøger; Cornelissen, Joep

    2015-01-01

    Transparency has achieved a mythical status in society. Myths are not false accounts or understandings, but deep-seated and definitive descriptions of the world that ontologically ground the ways in which we frame and see the world around us. We explore the mythical nature of transparency from...... of the transparency myth....

  20. Transparency and Oversight in Local Wellness Policies

    Science.gov (United States)

    Chriqui, Jamie F.; Chaloupka, Frank J.

    2011-01-01

    Background: Advocates have called for increased wellness policy transparency and oversight through the use of health advisory councils. This study examines (1) wellness policy transparency, (2) advisory council requirements, (3) factors associated with each, and (4) whether transparency or advisory council requirements are indicative of a stronger…

  1. Transparency in port-Hamiltonian based telemanipulation

    NARCIS (Netherlands)

    Secchi, C; Stramigioli, Stefano; Fantuzzi, C.

    2005-01-01

    After stability, transparency is the major issue in the design of a telemanipulation system. In this paper we exploit a behavioral approach in order to provide an index for the evaluation of transparency in port-Hamiltonian based teleoperators. Furthermore we provide a transparency analysis of

  2. Transparency in Port-Hamiltonian-Based Telemanipulation

    NARCIS (Netherlands)

    Secchi, Cristian; Stramigioli, Stefano; Fantuzzi, Cesare

    After stability, transparency is the major issue in the design of a telemanipulation system. In this paper, we exploit the behavioral approach in order to provide an index for the evaluation of transparency in port-Hamiltonian-based teleoperators. Furthermore, we provide a transparency analysis of

  3. Pixel masks for screen-door transparency

    NARCIS (Netherlands)

    J.D. Mulder (Jurriaan); F.C.A. Groen; J.J. van Wijk (Jack)

    1998-01-01

    textabstractRendering objects transparently gives additional insight in complex and overlapping structures. However, traditional techniques for the rendering of transparent objects such as alpha blending are not very well suited for the rendering of multiple transparent objects in dynamic scenes.

  4. Fabrication of large-volume, low-cost ceramic lanthanum halide scintillators for gamma ray detection : final report for DHS/DNDO/TRDD project TA-01-SL01.

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, Timothy J.; Ottley, Leigh Anna M.; Yang, Pin; Chen, Ching-Fong; Sanchez, Margaret R.; Bell, Nelson Simmons

    2008-10-01

    This project uses advanced ceramic processes to fabricate large, optical-quality, polycrystalline lanthanum halide scintillators to replace small single crystals produced by the conventional Bridgman growth method. The new approach not only removes the size constraint imposed by the growth method, but also offers the potential advantages of both reducing manufacturing cost and increasing production rate. The project goal is to fabricate dense lanthanum halide ceramics with a preferred crystal orientation by applying texture engineering and solid-state conversion to reduce the thermal mechanical stress in the ceramic and minimize scintillation light scattering at grain boundaries. Ultimately, this method could deliver the sought-after high sensitivity and <3% energy resolution at 662 keV of lanthanum halide scintillators and unleash their full potential for advanced gamma ray detection, enabling rapid identification of radioactive materials in a variety of practical applications. This report documents processing details from powder synthesis, seed particle growth, to final densification and texture development of cerium doped lanthanum bromide (LaBr{sub 3}:Ce{sup +3}) ceramics. This investigation demonstrated that: (1) A rapid, flexible, cost efficient synthesis method of anhydrous lanthanum halides and their solid solutions was developed. Several batches of ultrafine LaBr{sub 3}:Ce{sup +3} powder, free of oxyhalide, were produced by a rigorously controlled process. (2) Micron size ({approx} 5 {micro}m), platelet shape LaBr{sub 3} seed particles of high purity can be synthesized by a vapor phase transport process. (3) High aspect-ratio seed particles can be effectively aligned in the shear direction in the ceramic matrix, using a rotational shear-forming process. (4) Small size, highly translucent LaBr{sub 3} (0.25-inch diameter, 0.08-inch thick) samples were successfully fabricated by the equal channel angular consolidation process. (5) Large size, high density

  5. LEADING WITH LEADING INDICATORS

    International Nuclear Information System (INIS)

    PREVETTE, S.S.

    2005-01-01

    This paper documents Fluor Hanford's use of Leading Indicators, management leadership, and statistical methodology in order to improve safe performance of work. By applying these methods, Fluor Hanford achieved a significant reduction in injury rates in 2003 and 2004, and the improvement continues today. The integration of data, leadership, and teamwork pays off with improved safety performance and credibility with the customer. The use of Statistical Process Control, Pareto Charts, and Systems Thinking and their effect on management decisions and employee involvement are discussed. Included are practical examples of choosing leading indicators. A statistically based color coded dashboard presentation system methodology is provided. These tools, management theories and methods, coupled with involved leadership and employee efforts, directly led to significant improvements in worker safety and health, and environmental protection and restoration at one of the nation's largest nuclear cleanup sites

  6. Measurement of nuclear transparencies from exclusive ρ0 meson production in muon-nucleus scattering

    International Nuclear Information System (INIS)

    Fang, G.Y.

    1995-01-01

    Preliminary results on the measurement of nuclear transparencies from exclusive incoherent ρ 0 meson production off deuterium, carbon, calcium, and lead, normalized to hydrogen, and coherent ρ 0 meson production off calcium and lead, normalized to carbon, in deep-inelastic muon-nucleus scattering are reported. The data were collected with the E665 spectrometer using the Fermilab Tevatron muon beam with a mean beam energy of 470 GeV. Increases in the transparencies are observed in both coherent and incoherent production as the virtuality of the photon increases, as expected of color transparency. copyright 1995 American Institute of Physics

  7. Target Advertising and Market Transparency

    OpenAIRE

    Stühmeier, Torben

    2012-01-01

    This paper examines the effects of increased transparency over online news sources, e.g. due to news aggregators, on online news outlets and the advertising industry. The role of news aggregators is controversially discussed, where the discussion widely points on user side effect. The present paper widens the discussion on the advertising side and shows that aggregators can help to better target advertising messages to a more homogenous group of users and, in turn, may both benefit advertiser...

  8. When safety rhymes with transparency

    International Nuclear Information System (INIS)

    Champion, Marion; Larroque, Damien; Vandermersch, Marie

    2009-01-01

    The Transparency and Nuclear Safety Act, which took effect in 2006, requires each operator to document the measures taken to ensure nuclear safety and radiological protection and to list incidents and accidents as well as actions taken to protect the environment. This specifies the nature and limits of radioactive and non-radioactive releases, the quantity of waste to be stored at the facility, actions taken to limit waste volume, and effects on health and the environment, especially on soil and water. (authors)

  9. A route to transparent bulk metals

    KAUST Repository

    Schwingenschlögl, Udo

    2012-07-23

    Hypothetical compounds based on a sapphire host are investigated with respect to their structural as well as electronic features. The results are obtained by electronic structure calculations within density functional theory and the generalized gradient approximation. A quarter of the Al atoms in Al 2O 3 is replaced by a 4d transition metal M ion, with d 0 to d 9 electronic configuration. We perform structure optimizations for all the compounds and analyze the electronic states. Due to the sizeable band gap of the Al 2O 3 host, we can identify promising candidates for transparent bulk metals. We explain the mechanisms leading to this combination of materials properties. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. The effect of samarium doping on structure and enhanced thermionic emission properties of lanthanum hexaboride fabricated by spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shenlin; Hu, Qianglin [College of Mathematics and Physics, Jinggangshan University, Jian (China); Zhang, Jiuxing; Liu, Danmin [Key Laboratory of Advanced Functional Materials, Ministry of Education, College of Materials Science and Engineering, Beijing University of Technology, Beijing (China); Huang, Qingzhen [NIST Center for Neutron Research, National Institute of Standards and Technology, MD (United States)

    2014-03-15

    Single-phase polycrystalline solid solutions (La{sub 1-x}Sm{sub x})B{sub 6} (x = 0, 0.2, 0.4, 0.8, 1) are fabricated by spark plasma sintering (SPS). This study demonstrates a systematic investigation of structure-property relationships in Sm-doped LaB{sub 6} ternary rare-earth hexaborides. The microstructure, crystallographic orientation, electrical resistivity, and thermionic emission performance of these compounds are investigated. Analysis of the results indicates that samarium (Sm) doping has a noticeable effect on the structure and performance of lanthanum hexaboride (LaB{sub 6}). The analytical investigation of the electron backscatter diffraction confirms that (La{sub 0.6}Sm{sub 0.4})B{sub 6} exhibits a clear (001) texture that results in a low work function. Work functions are determined by pulsed thermionic diode measurements at 1500-1873 K. The (La{sub 0.6}Sm{sub 0.4})B{sub 6} possesses improved thermionic emission properties compared to LaB{sub 6}. The current density of (La{sub 0.6}Sm{sub 0.4})B{sub 6} is 42.4 A cm{sup -2} at 1873 K, which is 17.5% larger than that of LaB{sub 6}. The values of Φ{sub R} for (La{sub 0.6}Sm{sub 0.4})B{sub 6} and LaB{sub 6} are 1.98 ± 0.03 and 1.67 ± 0.03 eV, respectively. Furthermore, the Sm substitution of lanthanum (La) effectively increases the electrical resistivity. These results reveal that Sm doping lead to significantly enhanced thermionic emission properties of LaB{sub 6}. The compound (La{sub 0.6}Sm{sub 0.4})B{sub 6} appears most promising as a future emitter material. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Water transparency drives intra-population divergence in Eurasian Perch (Perca fluviatilis).

    Science.gov (United States)

    Bartels, Pia; Hirsch, Philipp E; Svanbäck, Richard; Eklöv, Peter

    2012-01-01

    Trait combinations that lead to a higher efficiency in resource utilization are important drivers of divergent natural selection and adaptive radiation. However, variation in environmental features might constrain foraging in complex ways and therefore impede the exploitation of critical resources. We tested the effect of water transparency on intra-population divergence in morphology of Eurasian perch (Perca fluviatilis) across seven lakes in central Sweden. Morphological divergence between near-shore littoral and open-water pelagic perch substantially increased with increasing water transparency. Reliance on littoral resources increased strongly with increasing water transparency in littoral populations, whereas littoral reliance was not affected by water transparency in pelagic populations. Despite the similar reliance on pelagic resources in pelagic populations along the water transparency gradient, the utilization of particular pelagic prey items differed with variation in water transparency in pelagic populations. Pelagic perch utilized cladocerans in lakes with high water transparency and copepods in lakes with low water transparency. We suggest that under impaired visual conditions low utilization of littoral resources by littoral perch and utilization of evasive copepods by pelagic perch may lead to changes in morphology. Our findings indicate that visual conditions can affect population divergence in predator populations through their effects on resource utilization.

  12. Selective isotope determination of lanthanum by diode-laser-initiated resonance-ionization mass spectrometry

    International Nuclear Information System (INIS)

    Young, J.P.; Shaw, R.W.

    1995-01-01

    A diode-laser step has been incorporated into a resonance-ionization mass spectrometry optical excitation process to enhance the isotopic selectivity of the technique. Lanthanum isotope ratio enhancements as high as 10 3 were achieved by use of a single-frequency cw diode laser tuned to excite the first step of a three-step excitation--ionization optical process; the subsequent steps were excited by use of a pulsed dye laser. Applying the same optical technique, we measured atomic hyperfine constants for the high-lying even-parity 4 D 5/2 state of lanthanum at 30 354 cm --1 . The general utility of this spectral approach is discussed

  13. Apparent molar volumes and compressibilities of lanthanum, gadolinium and lutetium trifluoromethanesulfonates in dimethylsulfoxide

    International Nuclear Information System (INIS)

    Warmińska, Dorota; Wawer, Jarosław

    2012-01-01

    Highlights: ► Sequence of volumes and compressibilities of Ln 3+ ions in DMSO is: La 3+ > Gd 3+ 3+ . ► Sequence of the partial molar volumes do not change with temperature. ► These results are the consequence of nature of the ion–solvent bonding. - Abstract: Temperature dependencies of the densities of dimethylsulfoxide solutions of lanthanum, gadolinium and lutetium trifluoromethanesulfonates have been determined over a wide range of concentrations. The apparent molar volumes and partial molar volumes of the salts at infinite dilution, as well as the expansibilities of the salts, have been calculated from density data. Additionally, the apparent molar isentropic compressibilities of lanthanum, gadolinium and lutetium trifluoromethanesulfonates have been calculated from sound velocity data at 298.15 K. The data obtained have been interpreted in terms of ion−solvent interactions.

  14. Paramagnetic resonance of Mn4+ and Mn2+ centers in lanthanum gallate single crystals

    Science.gov (United States)

    Vazhenin, V. A.; Potapov, A. P.; Guseva, V. B.; Artyomov, M. Yu.

    2010-03-01

    An increase in the manganese concentration in lanthanum gallate in the range 0.5-5.0% has been found to result in a complete replacement of individual Mn4+ ions by Mn2+ ions. The relative concentrations and binding energies of individual Mn4+, Mn3+, and Mn2+ ions have been determined. The spin Hamiltonians of the Mn2+ and Mn4+ centers in the rhombohedral and orthorhombic phases, respectively, have been constructed and the orientation of the principal axes of the fine-structure tensor of Mn4+ at room temperature has been found. The possibility of using electron paramagnetic resonance for determining the rotation angles of oxygen octahedra of lanthanum gallate with respect to the perovskite structure has been discussed.

  15. Near fifty percent sodium substituted lanthanum manganites—A potential magnetic refrigerant for room temperature applications

    Energy Technology Data Exchange (ETDEWEB)

    Sethulakshmi, N.; Anantharaman, M. R., E-mail: mraiyer@yahoo.com [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India); Al-Omari, I. A. [Department of Physics, Sultan Qaboos University, PC 123 Muscat, Sultanate of Oman (Oman); Suresh, K. G. [Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India)

    2014-03-03

    Nearly half of lanthanum sites in lanthanum manganites were substituted with monovalent ion-sodium and the compound possessed distorted orthorhombic structure. Ferromagnetic ordering at 300 K and the magnetic isotherms at different temperature ranges were analyzed for estimating magnetic entropy variation. Magnetic entropy change of 1.5 J·kg{sup −1}·K{sup −1} was observed near 300 K. An appreciable magnetocaloric effect was also observed for a wide range of temperatures near 300 K for small magnetic field variation. Heat capacity was measured for temperatures lower than 300 K and the adiabatic temperature change increases with increase in temperature with a maximum of 0.62 K at 280 K.

  16. The rare earth element (REE) lanthanum (La) induces hormesis in plants.

    Science.gov (United States)

    Agathokleous, Evgenios; Kitao, Mitsutoshi; Calabrese, Edward J

    2018-07-01

    Lanthanum is a rare earth element (REE) which has been extensively studied due to its wide application in numerous fields with a potential accumulation in the environment. It has long been known for its potential to stimulate plant growth within a hormetic-biphasic dose response framework. This article provides evidence from a series of high resolution studies published within the last two decades demonstrating a substantial and significant occurrence of lanthanum-induced hormesis in plants. These findings suggest that hormetic responses should be built into the study design of hazard assessment study protocols and included in the risk assessment process. Hormesis also offers the opportunity to substantially improve cost benefit estimates for environmental contaminants, which have the potential to induce beneficial/desirable effects at low doses. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Determination of Aluminum in Dialysis Concentrates by Atomic Absorption Spectrometry after Coprecipitation with Lanthanum Phosphate.

    Science.gov (United States)

    Selvi, Emine Kılıçkaya; Şahin, Uğur; Şahan, Serkan

    2017-01-01

    This method was developed for the determination of trace amounts of aluminum(III) in dialysis concentrates using atomic absorption spectrometry after coprecipitation with lanthanum phosphate. The analytical parameters that influenced the quantitative coprecipitation of analyte including amount of lanthanum, amount of phosfate, pH and duration time were optimized. The % recoveries of the analyte ion were in the range of 95-105 % with limit of detection (3s) of 0.5 µg l -1 . Preconcentration factor was found as 1000 and Relative Standard Deviation (RSD) % value obtained from model solutions was 2.5% for 0.02 mg L -1 . The accuracy of the method was evaluated with standard reference material (CWW-TMD Waste Water). The method was also applied to most concentrated acidic and basic dialysis concentrates with satisfactory results.

  18. Molecular absorption spectra of beryllium, cerium, lanthanum, iron, and platinum salts

    International Nuclear Information System (INIS)

    Daidoji, Hidehiro

    1980-01-01

    The absorption spectra of some salts of beryllium, cerium, lanthanum, iron and platinum in air-acetylene flame were measured in the wavelength range from 200 to 400 nm. A Hitachi 207 type atomic absorption spectrophotometer was used. A deuterium lamp, a home-made continuous radiation lamp and some hollow cathode lamps were used as light sources. The new molecular absorption spectra of cerium, lanthanum and platinum and the absorption spectra due to Be(OH) 2 , LaO, PtH, FeO and FeCl in 200-400 nm region were obtained. Emission spectra of CeO, LaO and FeOH were also obtained. These molecular absorption bands were estimated as absorption errors of maximum 15 times to the sensitivity of each elements in atomic absorption spectrometry. In addition, spectral line interferences of iron were observed in atomic absorption spectrometry of Zn, Cd, Ni, Cu and Cr. (author)

  19. Oriented growing and anisotropy of emission properties of lanthanum hexaboride single crystals

    International Nuclear Information System (INIS)

    Lazorenko, V.I.; Lotsko, D.V.; Platonov, V.F.; Kovalev, A.V.; Galasun, A.P.; Matvienko, A.A.; Klinkov, A.E.

    1987-01-01

    Single crystals of lanthanum hexaboride with preset crystallographic orientation are grown by the method of crucible-free zone melting. It is shown that oriented growing of single crystals of the given compound is possible only when using seed crystals of the required orientation because no predominant orientation of the LaB 6 growth is found in case of spontaneous crystallization. Orientation of spontaneously growing LaB 6 crystals does not depend on their growth rate, degree of the melt diffusion annealing, purity of the inital powder. Anisotropy of the electronic work function for single crystal lanthanum hexaboride is confirmed. Its value grows as (100)<(110)<(111). Conditions of the preliminary thermovacuum purification of the surface are shown to affect the measured work function

  20. Transparent conductor based on aluminum nanomesh

    International Nuclear Information System (INIS)

    Kazarkin, B; Mohammed, A S; Stsiapanau, A; Zhuk, S; Satskevich, Y; Smirnov, A

    2014-01-01

    We report a transparent conductor based on Al nanomesh, which was fabricated through Al anodization and etching processes. The Al anodization was performed at low temperature condition to slow down the anodization rate to achieve the well-controlled thickness of an Al nanomesh. By careful controlling of the anodization process, we can fabricate Al nanomesh transparent conductors with different sheet resistance and optical transparency in the visible spectrum range. We shall show that Al nanomesh transparent conductor is a strong contender for a transparent conductor dominated by ITO

  1. Transparency in high-energy nuclear collisions

    International Nuclear Information System (INIS)

    Karol, P.J.

    1992-01-01

    Problems associated with transparency schemes based on sharp cutoff models are discussed. The soft spheres model of hadron-nucleus and nucleus-nucleus collisions has been used to explore the influence of the realistic nuclear density geometry on transparency. An average nuclear transparency and an average reaction transparency are defined and their dependence on target and projectile dimensions and on the hadron-nucleon collision cross section are described. The results are expected to be valid for projectile energies above several hundred MeV/nucleon through the ultrarelativistic regime. For uniform (hard sphere) nuclear profiles, methods for obtaining effective total transparencies are suggested

  2. Evaluation and comparison of two complexometric titration methods for determining of lanthanum in cloridric solutions

    International Nuclear Information System (INIS)

    Menezes, M.F.; Santos, R.L.C. dos; Goes, M.A.C. de

    1994-01-01

    The fast determination of total rare earth concentration in aqueous solutions is based on titrimetric methods using EDTA as complexing agent. This paper evaluates two among several others titrimetric methods used in the determination of lanthanum in hydrochloric acid solutions, using xylenol orange and a mixture of methyl orange and xylenol orange as indicators. The applied statistical evaluation allowed the determination of the stability, accuracy and adequacy of these methods on a given technical specification. (author). 12 refs., 03 tabs., 01 fig

  3. Room temperature synthesis of high temperature stable lanthanum phosphate–yttria nano composite

    International Nuclear Information System (INIS)

    Sankar, Sasidharan; Raj, Athira N.; Jyothi, C.K.; Warrier, K.G.K.; Padmanabhan, P.V.A.

    2012-01-01

    Graphical abstract: A facile aqueous sol–gel route involving precipitation–peptization mechanism followed by electrostatic stabilization is used for synthesizing nanocrystalline composite containing lanthanum phosphate and yttria. Highlights: ► A novel lanthanum phosphate–Y 2 O 3 nano composite is synthesized for the first time using a modified facile sol gel process. ► The composite becomes crystalline at 600 °C and X-ray diffraction pattern is indexed for monoclinic LaPO 4 and cubic yttria. ► The composite synthesized was tested up to 1300 °C and no reaction between the phases of the constituents is observed with the morphologies of the phases being retained. -- Abstract: A facile aqueous sol–gel route involving precipitation–peptization mechanism followed by electrostatic stabilization is used for synthesizing nanocrystalline composite containing lanthanum phosphate and yttria. Lanthanum phosphate (80 wt%)–yttria (20 wt%) nano composite (LaPO 4 –20%Y 2 O 3 ), has an average particle size of ∼70 nm after heat treatment of precursor at 600 °C. TG–DTA analysis reveals that stable phase of the composite is formed on heating the precursor at 600 °C. The TEM images of the composite show rod shape morphology of LaPO 4 in which yttria is acquiring near spherical shape. Phase identification of the composite as well as the phase stability up to 1300 °C was carried out using X-ray diffraction technique. With the phases being stable at higher temperatures, the composite synthesized should be a potential material for high temperature applications like thermal barrier coatings and metal melting applications.

  4. Preparation, characterization and optical properties of Lanthanum-(nanometer MCM-41) composite materials

    International Nuclear Information System (INIS)

    Zhai, Q. Z.; Wang, P.

    2008-01-01

    Nanometer MCM-41 molecular sieve was prepared under a base condition by using cetyltrimethylammonium bromide as template and tetraethyl orthosilicate as silica source by means of hydrothermal method. Lanthanum(III) was incorporated into the nanometer MCM-41 by a liquid phase grafting method. The prepared nano composite materials were characterized by means of powder X-ray diffraction, spectrophotometric analysis, Fourier transform infrared spectroscopy, low temperature nitrogen adsorption-desorption technique, solid diffuse reflectance absorption spectra and luminescence. The powder X-ray diffraction studies show that the nanometer MCM-41 molecular sieve is successfully prepared. The highly ordered meso porous two-dimensional hexagonal channel structure and framework of the support MCM-41 is retained intact in the prepared composite material La-(nanometer MCM-41). The spectrophotometric analysis indicates that lanthanum exists in the prepared nano composite materials. The Fourier transform infrared spectra indicate that the framework of the MCM-41 molecular sieve still remains in the prepared nano composite materials and some framework vibration peaks show blue shifts relative to those of the MCM-41 molecular sieve. The low temperature nitrogen adsorption-desorption indicates that the guest locales in the channel of the molecular sieve. Compared with bulk lanthanum oxide, the guest in the channel of the molecular sieve has smaller particle size and shows a significant blue shift of optical absorption band in solid diffuse reflectance absorption spectra. The observed blue shift in the solid state diffuse reflectance absorption spectra of the lanthanum-(nanometer MCM-41) sample show the obvious stereoscopic confinement effect of the channel of the host on the guest, which further indicates the successful encapsulation of the guest in the host. The La-(nanometer MCM-41) sample shows luminescence

  5. Energetically benign synthesis of lanthanum silicate through “silica garden” route and its characterization

    Energy Technology Data Exchange (ETDEWEB)

    Parmar, Kavita [Central University of Jharkhand, Ranchi (India); Bhattacharjee, Santanu, E-mail: santanu@nmlindia.org [CSIR-National Metallurgical Laboratory, Jamshedpur (India)

    2017-06-15

    Lanthanum silicate synthesis through “silica garden” route has been reported as an alternative to energy intensive milling procedure. Under optimum conditions lanthanum chloride crystals react with water glass (sodium silicate) to produce self generating hollow lanthanum silicate precipitation tube(s) (LaSPT). The micro tubes are irregular, thick, white coloured and amorphous but are hierarchically built from smaller tubules of 10–20 nm diameters. They retain their amorphous nature on being heated up to 600 °C beyond which crystallization starts. The major phase in the LaSPT heated at 900 °C is La{sub 2}Si{sub 2}O{sub 7}. “As synthesized” LaSPT is heterogeneous and comprises non stoichiometric phases. The exterior and interior surfaces of these tubes are remarkably different in their morphology and chemical composition. LaSPT sintered at 1200 and 1300 °C show fair amount of ionic conductivity. - Graphical abstract: Lanthanum silicate precipitation tube (LaSPT) produced through ‘silica garden’ route offers a green alternative to energy intensive milling procedure. - Highlights: • La-silicate precipitation tube (LaSPT) synthesized via silica garden route. • The microtubes are irregular, thick, white coloured and amorphous. • They are hierarchically built from smaller tubules of 10–20 nm diameters. • The major phase in the LaSPT heated at 900 °C is La{sub 2}Si{sub 2}O{sub 7}. • LaSPT sintered at 1200 °C is fairly conducting.

  6. Exploring Quantitative Framework to Evaluate Nuclear Transparency

    International Nuclear Information System (INIS)

    Ha, Jeemin; Yim, Mansung; Park, Hyeon Seok

    2014-01-01

    In this work, a definition of nuclear transparency is elaborated and ways to represent a country's nuclear transparency are examined. For evaluating nuclear transparency, it is necessary to define three elements first; an information seeker who wants to see, an information seek whom an information seeker wants to see, and information related to nuclear materials and activities. The States with high capacity of civilian nuclear power had a tendency to follow IAEA safeguards agreements well. And it means that their levels of the transparency are relatively high. Besides, the data of international assurances is one of the good indicators to confirm States' transparency. The current study explored the use of two measures, IAEA safeguards and voluntary reporting as a way to represent nuclear transparency. Using these measures seemed to agree with the notion that nuclear transparency is important in the success of civilian nuclear power development

  7. Practice Variation in Big-4 Transparency Reports

    DEFF Research Database (Denmark)

    Girdhar, Sakshi; Klarskov Jeppesen, Kim

    2018-01-01

    Purpose: The purpose of this paper is to examine the transparency reports published by the Big-4 public accounting firms in the UK, Germany and Denmark to understand the determinants of their content within the networks of big accounting firms. Design/methodology/approach: The study draws...... on a qualitative research approach, in which the content of transparency reports is analyzed and semi-structured interviews are conducted with key people from the Big-4 firms who are responsible for developing the transparency reports. Findings: The findings show that the content of transparency reports...... is inconsistent and the transparency reporting practice is not uniform within the Big-4 networks. Differences were found in the way in which the transparency reporting practices are coordinated globally by the respective central governing bodies of the Big-4. The content of the transparency reports...

  8. Impact of Annealing Temperature on the Physical Properties of the Lanthanum Deficiency Manganites

    Directory of Open Access Journals (Sweden)

    Skini Ridha

    2017-10-01

    Full Text Available The lanthanum deficiency manganites La0.8-x□xCa0.2MnO3 (x = 0, 0.1 and 0.2, where □ is a lanthanum vacancy, were prepared using the classic ceramic methods with different thermal treatments (1373 K and 973 K. The structural, magnetic, and magnetocaloric properties of these compounds were studied as a function of annealing temperature. It was noted that the annealing temperature did not affect the crystal structure of our samples (orthorhombic structure with Pnma space group. Nevertheless, a change in the variation of the unit cell volume V, the average bond length dMn–O, and the average bond angles θMn–O–Mn were observed. Magnetization versus temperature study has shown that all samples exhibited a magnetic transition from ferromagnetic (FM to paramagnetic (PM phase with increasing temperature. However, it can be clearly seen that the annealing at 973 K induced an increase of the magnetization. In addition, the magnetocaloric effect (MCE as well as the relative cooling power (RCP were estimated. As an important result, the values of MCE and RCP in our Lanthanum-deficiency manganites are reported to be near to those found in gadolinium, considered as magnetocaloric reference material.

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

    International Nuclear Information System (INIS)

    Vasconcelos, Mari Estela de

    2006-01-01

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

  10. Development of a 1 kW Class SOFC Stack using Doped Lanthanum Gallate

    Energy Technology Data Exchange (ETDEWEB)

    Akikusa, J.; Adachi, K.; Yamada, T.; Akbay, T.; Murakami, N.; Chitose, N.; Hoshino, K.; Hosoi, K.; Yoshida, H.; Sasaki, T.; Inagaki, T.; Ishihara, T.; Takita, Y.

    2002-06-01

    The performance of lanthanum gallate based SOFC has been investigated as a high-energy conversion device. A planar type SOFC which could operate at temperatures below 800 {sup o}C has been jointly developed. As an electrolyte material, lanthanum gallate (LaGaO{sub 3}) with substitutions of Sr for the La site and Mg and Co for the Ga site (LSGMC) was used. The synthesis technique for large-sized cell production has been established, and the performance of a self- supported diameter 154 mm cell with 200 {mu}m electrolyte thickness is investigated. The output power of 50 W has been obtained with a conversion efficiency [LHV] of 45 % for a single cell. In addition, a metallic separator made of stainless steel was chosen and tested successfully for a seal-less stack. The output power of 1 kW by means of the stack of 18 cells has been achieved for the first time utilizing lanthanum gallate. Moreover, NiO-SDC composite powders were prepared by the spray pyrolysis method and used for the anode on 100 {mu}m thickness LSGMC electrolyte with a combination of samarium cobaltite for the cathode. The power density of as high as 1.8 W/cm{sup 2} at 0.7 V terminal voltage was achieved at 800{sup o}C. (author)

  11. Deposition barium titanate (BaTiO3) doped lanthanum with chemical solution deposition

    International Nuclear Information System (INIS)

    Iriani, Y.; Nurhadi, N.; Jamaludin, A.

    2016-01-01

    Deposition of Barium Titanate (BaTiO 3 ) thin films used Chemical Solution Deposition (CSD) method and prepared with spin coater. BaTiO 3 is doped with lanthanum, 1%, 2%, and 3%. The thermal process use annealing temperature 900°C and holding time for 3 hours. The result of characterization with x-ray diffraction (XRD) equipment show that the addition of La 3+ doped on Barium Titanate caused the change of angle diffraction.The result of refine with GSAS software shows that lanthanum have been included in the structure of BaTiO 3 . Increasing mol dopant La 3+ cause lattice parameter and crystal volume become smaller. Characterization result using Scanning Electron Microscopy (SEM) equipment show that grain size (grain size) become smaller with increasing mole dopant (x) La 3+ . The result of characterization using Sawyer Tower methods show that all the samples (Barium Titanante and Barium Titanate doped lanthanum) are ferroelectric material. Increasing of mole dopant La 3+ cause smaller coercive field and remanent polarization increases. (paper)

  12. Eucalyptus tolerance mechanisms to lanthanum and cerium: subcellular distribution, antioxidant system and thiol pools.

    Science.gov (United States)

    Shen, Yichang; Zhang, Shirong; Li, Sen; Xu, Xiaoxun; Jia, Yongxia; Gong, Guoshu

    2014-12-01

    Guanglin 9 (Eucalyptus grandis × Eucalyptus urophlla) and Eucalyptus grandis 5 are two eucalyptus species which have been found to grow normally in soils contaminated with lanthanum and cerium, but the tolerance mechanisms are not clear yet. In this study, a pot experiment was conducted to investigate the tolerance mechanisms of the eucalyptus to lanthanum and cerium. Cell walls stored 45.40-63.44% of the metals under lanthanum or cerium stress. Peroxidase and catalase activities enhanced with increasing soil La or Ce concentrations up to 200 mg kg(-1), while there were no obvious changes in glutathione and ascorbate concentrations. Non-protein thiols concentrations increased with increasing treatment levels up to 200 mg kg(-1), and then decreased. Phytochelatins concentrations continued to increase under La or Ce stress. Therefore, the two eucalyptus species are La and Ce tolerant plants, and the tolerance mechanisms include cell wall deposition, antioxidant system response, and thiol compound synthesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. On magnetic ordering in heavily sodium substituted hole doped lanthanum manganites

    Energy Technology Data Exchange (ETDEWEB)

    Sethulakshmi, N. [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India); Unnimaya, A.N. [Centre for Materials for Electronic Technology (CMET), Thrissur 680581, Kerala (India); Al-Omari, I.A.; Al-Harthi, Salim [Department of Physics, Sultan Qaboos University, PC 123 Muscat (Oman); Sagar, S. [Government College for Women, Thiruvananthapuram 695014, Kerala (India); Thomas, Senoy [Materials Science and Technology Division, National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, Kerala (India); Srinivasan, G. [Department of Physics, Oakland University, Rochester (United States); Anantharaman, M.R., E-mail: mraiyer@yahoo.com [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India)

    2015-10-01

    Mixed valence manganite system with monovalent sodium substituted lanthanum manganites form the basis of the present work. Lanthanum manganites belonging to the series La{sub 1−x}Na{sub x}MnO{sub 3} with x=0.5–0.9 were synthesized using modified citrate gel method. Variation of lattice parameters and unit cell volume with Na concentration were analyzed and the magnetization measurements indicated ferromagnetic ordering in all samples at room temperature. Low temperature magnetization behavior indicated that all samples exhibit antiferromagnetism along with ferromagnetism and it has also been observed that antiferromagnetic ordering dominates ferromagnetic ordering as concentration is increased. Evidence for such a magnetic inhomogeneity in these samples has been confirmed from the variation in Mn{sup 3+}/Mn{sup 4+} ion ratio from X-ray Photoelectron Spectroscopy and from the absorption peak studies using Ferromagnetic Resonance Spectroscopy. - Highlights: • Higher substitution of more than 50 percent of monovalent ion, sodium for La sites in lanthanum manganites scarce in literature. • Structural studies using XRD and further structure refinement by Rietveld refinement confirmed orthorhombic pbnm spacegroup. • Ferromagnetic behavior at room temperature with saturation magnetization decreasing with increase in sodium concentration. • M vs T measurements using FC ZFC proved coexisting FM/AFM behavior arising from exchange interactions between different valence states of Mn ions. • Disparity in ratio of Mn valence ions indicated presence of vacancies providing the role of vacancies and oxygen stoichiometry in deciding magnetic inhomogeneity.

  14. Effects of intravenously injected lanthanum chloride on the femur of rats

    International Nuclear Information System (INIS)

    Miyagawa, Makoto; Daimon, Tateo

    2010-01-01

    Lanthanum (La) is widely used in industry and medicine. Because of lanthanum's physicochemical resemblance to calcium, the possible effects of it on bone have to be considered. The aim of this study was to examine the effects of La on bone toxicity. Rats were intravenously administrated with lanthanum chloride at 5 mg La/kg per week for five weeks. Histomorphometric analysis of femurs were performed using micro-CT scan. Compared with normal controls, the total bone area of the femur did not show any change in La-administrated rats, whereas the trabecular area slightly decreased. The trabecular bone mineral density in the experimented rats was higher than that in the normal controls, although the mineral density of the cortical bone and cancerou one was unchanged after the administration of La. La did not alter mechanical barometers of the femur such as mean cross-sectional moment of inertia, minimum cross-sectional moment of inertia and polar moment of inertia. Additionally, light microscopic analysis of the femurs revealed that histological features of osteoid, calcification front and bone matrix were normal after the administration of La. La was detected in the macrophages in the bone marrow, but not in the bone matrix by histological stain for La and X-ray fluorescence microanalysis. Thus, these micro-CT imaging and microscopy of the femurs did not reveal toxic changes due to La. (author)

  15. Microstructured fibers with high lanthanum oxide glass core for nonlinear applications

    Science.gov (United States)

    Kobelke, J.; Schuster, K.; Litzkendorf, D.; Schwuchow, A.; Kirchhof, J.; Bartelt, H.; Tombelaine, V.; Leproux, P.; Couderc, V.; Labruyere, A.

    2009-05-01

    We demonstrate a low loss microstructured fiber (MOF) with a high nonlinear glass core and silica holey cladding. The substitution of mostly used silica as core material of microstructured fibers by lanthanum oxide glass promises a high nonlinear conversion efficiency for supercontinuum (SC) generation. The glass composition is optimized in terms of thermochemical and optical requirements. The glass for the MOF core has a high lanthanum oxide concentration (10 mol% La2O3) and a good compatibility with the silica cladding. This is performed by adding a suitable alumina concentration up to 20 mol%. The lanthanum oxide glass preform rods were manufactured by melting technique. Besides purity issues the material homogeneity plays an important role to achieve low optical loss. The addition of fluorides allows the better homogenization of the glass composition in the preform volume by refining. The minimum attenuation of an unstructured fiber drawn from this glass is about 0.6 dB/m. It is mostly caused by decreasing of scattering effects. The microstructured silica cladding allows the considerable shifting of dispersive behavior of the MOF for an optimal pump light conversion. The MOF shows zero dispersion wavelengths (ZDW) of 1140 nm (LP01 mode) and 970 nm (LP11 mode). The supercontinuum generation was investigated with a 1064 nm pump laser (650 ps). It shows a broad band emission between 500 nm and 2200 nm.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-01-01

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

  17. Transparency as an element of public confidence

    International Nuclear Information System (INIS)

    Kim, H.K.

    2007-01-01

    In the modern society, there is increasing demands for greater transparency. It has been discussed with respect to corruption or ethics issues in social science. The need for greater openness and transparency in nuclear regulation is widely recognised as public expectations on regulator grow. It is also related to the digital and information technology that enables disclosures of every activity and information of individual and organisation, characterised by numerous 'small brothers'. Transparency has become a key word in this ubiquitous era. Transparency in regulatory activities needs to be understood in following contexts. First, transparency is one of elements to build public confidence in regulator and eventually to achieve regulatory goal of providing the public with satisfaction at nuclear safety. Transparent bases of competence, independence, ethics and integrity of working process of regulatory body would enhance public confidence. Second, activities transmitting information on nuclear safety and preparedness to be accessed are different types of transparency. Communication is an active method of transparency. With increasing use of web-sites, 'digital transparency' is also discussed as passive one. Transparency in regulatory process may be more important than that of contents. Simply providing more information is of little value and specific information may need to be protected for security reason. Third, transparency should be discussed in international, national and organizational perspectives. It has been demanded through international instruments. for each country, transparency is demanded by residents, public, NGOs, media and other stakeholders. Employees also demand more transparency in operating and regulatory organisations. Whistle-blower may appear unless they are satisfied. Fourth, pursuing transparency may cause undue social cost or adverse effects. Over-transparency may decrease public confidence and the process for transparency may also hinder

  18. Lake responses following lanthanum-modified bentonite clay (Phoslock®) application: an analysis of water column lanthanum data from 16 case study lakes.

    Science.gov (United States)

    Spears, Bryan M; Lürling, Miquel; Yasseri, Said; Castro-Castellon, Ana T; Gibbs, Max; Meis, Sebastian; McDonald, Claire; McIntosh, John; Sleep, Darren; Van Oosterhout, Frank

    2013-10-01

    Phoslock(®) is a lanthanum (La) modified bentonite clay that is being increasingly used as a geo-engineering tool for the control of legacy phosphorus (P) release from lake bed sediments to overlying waters. This study investigates the potential for negative ecological impacts from elevated La concentrations associated with the use of Phoslock(®) across 16 case study lakes. Impact-recovery trajectories associated with total lanthanum (TLa) and filterable La (FLa) concentrations in surface and bottom waters were quantified over a period of up to 60 months following Phoslock(®) application. Both surface and bottom water TLa and FLa concentrations were 0.8 mEq L(-1)), but higher (up to 0.12 mg L(-1)) in lakes characterised by very low alkalinity. The effects of elevated La(3+) concentrations following Phoslock(®) applications in lakes of very low alkalinity requires further evaluation. The implications for the use of Phoslock(®) in eutrophication management are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Measurement of nuclear transparencies from exclusive ρ0 meson production in muon-nucleus scattering at 470 GeV

    International Nuclear Information System (INIS)

    Adams, M.R.; Aied, S.; Anthony, P.L.; Averill, D.A.; Baker, M.D.; Baller, B.R.; Banerjee, A.; Bhatti, A.A.; Bratzler, U.; Braun, H.M.; Breidung, H.; Busza, W.; Carroll, T.J.; Clark, H.L.; Conrad, J.M.; Davisson, R.; Derado, I.; Dhawan, S.K.; Dietrich, F.S.; Dougherty, W.; Dreyer, T.; Eckardt, V.; Ecker, U.; Erdmann, M.; Faller, F.; Fang, G.Y.; Figiel, J.; Finlay, R.W.; Gebauer, H.J.; Geesaman, D.F.; Griffioen, K.A.; Guo, R.S.; Haas, J.; Halliwell, C.; Hantke, D.; Hicks, K.H.; Hughes, V.W.; Jackson, H.E.; Jancso, G.; Jansen, D.M.; Jin, Z.; Kaufman, S.; Kennedy, R.D.; Kinney, E.R.; Kirk, T.; Kobrak, H.G.E.; Kotwal, A.V.; Kunori, S.; Lancaster, S.; Lord, J.J.; Lubatti, H.J.; McLeod, D.; Madden, P.; Magill, S.; Manz, A.; Melanson, H.; Michael, D.G.; Montgomery, H.E.; Morfin, J.G.; Nickerson, R.B.; O'Day, S.; Olkiewicz, K.; Osborne, L.; Otten, R.; Papavassiliou, V.; Pawlik, B.; Pipkin, F.M.; Potterveld, D.H.; Ramberg, E.J.; Roeser, A.; Ryan, J.J.; Salgado, C.W.; Salvarani, A.; Schellman, H.; Schmitt, M.; Schmitz, N.; Schueler, K.P.; Siegert, G.; Skuja, A.; Snow, G.A.; Soeldner-Rembold, S.; Spentzouris, P.; Stier, H.E.; Stopa, P.; Swanson, R.A.; Venkataramania, H.; Wilhelm, M.; Wilson, R.; Wittek, W.; Wolbers, S.A.; Zghiche, A.; Zhao, T.

    1995-01-01

    Nuclear transparencies measured in exclusive incoherent ρ 0 meson production from hydrogen, deuterium, carbon, calcium, and lead in muon-nucleus scattering are reported. The data were obtained with the E665 spectrometer using the Fermilab Tevatron muon beam with a mean beam energy of 470 GeV. Increases in the nuclear transparencies are observed as the virtuality of the photon increases, in qualitative agreement with the expectations of color transparency

  20. Scheduling and Optimization of Fault-Tolerant Embedded Systems with Transparency/Performance Trade-Offs

    DEFF Research Database (Denmark)

    Izosimov, Viacheslav; Pop, Paul; Eles, Petru

    2012-01-01

    In this article, we propose a strategy for the synthesis of fault-tolerant schedules and for the mapping of fault-tolerant applications. Our techniques handle transparency/performance trade-offs and use the faultoccurrence information to reduce the overhead due to fault tolerance. Processes...... and messages are statically scheduled, and we use process reexecution for recovering from multiple transient faults. We propose a finegrained transparent recovery, where the property of transparency can be selectively applied to processes and messages. Transparency hides the recovery actions in a selected part...... of the application so that they do not affect the schedule of other processes and messages. While leading to longer schedules, transparent recovery has the advantage of both improved debuggability and less memory needed to store the faulttolerant schedules....

  1. Materials system for intermediate temperature solid oxide fuel cells based on doped lanthanum-gallate electrolyte

    Science.gov (United States)

    Gong, Wenquan

    2005-07-01

    The objective of this work was to identify a materials system for intermediate temperature solid oxide fuel cells (IT-SOFCs). Towards this goal, alternating current complex impedance spectroscopy was employed as a tool to study electrode polarization effects in symmetrical cells employing strontium and magnesium doped lanthanum gallate (LSGM) electrolyte. Several cathode materials were investigated including strontium doped lanthanum manganite (LSM), Strontium and iron doped lanthanum cobaltate (LSCF), LSM-LSGM, and LSCF-LSGM composites. Investigated Anode materials included nickel-gadolinium or lanthanum doped cerium oxide (Ni-GDC, or Ni-LDC) composites. The ohmic and the polarization resistances of the symmetrical cells were obtained as a function of temperature, time, thickness, and the composition of the electrodes. Based on these studies, the single phase LSM electrode had the highest polarization resistance among the cathode materials. The mixed-conducting LSCF electrode had polarization resistance orders of magnitude lower than that of the LSM-LSGM composite electrodes. Although incorporating LSGM in the LSCF electrode did not reduce the cell polarization resistance significantly, it could reduce the thermal expansion coefficient mismatch between the LSCF electrodes and LSGM electrolyte. Moreover, the polarization resistance of the LSCF electrode decreased asymptotically as the electrode thickness was increased thus suggesting that the electrode thickness needed not be thicker than this asymptotic limit. On the anode side of the IT-SOFC, Ni reacted with LSGM electrolyte, and lanthanum diffusion occurred from the LSGM electrolyte to the GDC barrier layer, which was between the LSGM electrolyte and the Ni-composite anode. However, LDC served as an effective barrier layer. Ni-LDC (70 v% Ni) anode had the largest polarization resistance, while all other anode materials, i.e. Ni-LDC (50 v% Ni), Ni-GDC (70 v% NO, and Ni-GDC (50 v% Ni), had similar polarization

  2. Effect of voltage on the characteristics of magnesium-lanthanum deposits synthesized by an electrodeposition process

    Energy Technology Data Exchange (ETDEWEB)

    Sahli, M. [Laboratoire de Physique Energétique, Université de Constantine 1 (Algeria); Chetehouna, K.; Gascoin, N. [INSA-CVL, Univ. Orléans, PRISME, EA 4229, F-18020, Bourges (France); Bellel, N. [Laboratoire de Physique Energétique, Université de Constantine 1 (Algeria); Tadini, P., E-mail: tadini.pietro@gmail.com [INSA-CVL, Univ. Orléans, PRISME, EA 4229, F-18020, Bourges (France)

    2017-04-15

    This work deals with the characterization of magnesium-lanthanum powders deposits produced with an electrodeposition technique using an aqueous solution based on magnesium chloride and lanthanum(III) nitrate. In recent years, the interest for magnesium-based alloys is growing due to their potential use as solid state systems for hydrogen storage. This work is a preliminary study on the synthesis of magnesium-lanthanum powders oriented to their later evaluation in systems for hydrogen storage. Magnesium and Lanthanum are deposited on a copper plate used as a cathode. Chemical composition, structure and morphology are investigated by EDS, XRD, FTIR and SEM. The effect of voltage on powders characteristics is studied considering three values (3, 3.5 and 4 V). EDS analysis shows the presence of three major elements (Mg, La and O) with a little amount of Cl. The weight percentages of Mg and O increase whereas the one of La decreases with the growth of voltage. Morphological characterization reveals that heterogeneous chemical structures are formed on the surface of the electrode and the size of aggregates decreases with the increase of voltage. From the results of X-ray analysis the deposits reveal the significant presence of two phases: Mg(OH){sub 2} and La(OH){sub 3}. The peaks originating from the Mg(OH){sub 2} phase has a non-monotonic behavior and those of La(OH){sub 3} phase increase with the increase of voltage. FTIR analysis confirms the presence of the two phases identified in XRD diffractograms and exhibits that their corresponding transmittance values increase for higher voltage values. - Highlights: • Synthesis of magnesium-lanthanum deposits by an electrodeposition process. • Voltage effect is investigated using different physicochemical analysis techniques (EDS, XRD, FTIR and SEM). • The EDS analysis shows the presence of three major elements (Mg, La and O) and a little amount of Cl. • Two phases, namely Mg(OH){sub 2} and La(OH){sub 3} are

  3. Transparency as Ideal and Practice

    DEFF Research Database (Denmark)

    Garsten, Christina; Jacobsson, Kerstin

    2016-01-01

    New Public Management (NPM) ideas and practices have significantly reshaped labour market policy. This article takes a closer look at some of the implications of NPM practices and “audit culture” at local Public Employment Service (PES) authorities in Sweden. Based on interviews with staff...... of government” that make transparent and “legible” desirable traits in the individual. Such classificatory schemes, we argue, are integral parts of the operational procedures of NPM. Moreover, the analysis shows that the categories through which the individual moves are plastic and pliable in relation...... to political predicates and labour market fluctuations. In this process, employability and disability become floating categories...

  4. Transparent doesn't always make it right

    Energy Technology Data Exchange (ETDEWEB)

    Frishman, S. [Nevada Agency for Nuclear Projects, Carson City, NV (United States)

    1999-12-01

    The increasing drive for transparency in risk assessment, performance assessment, and decision-making in the controversial area of nuclear waste management has its foundation in the desire to foster the assumption that, if the outcome of the process is a clear result of the fully exposed contributory elements, then that outcome must be accepted as correct. This is in stark contrast to the general need for transparency in any analysis or decision process - to give the outcome credibility. Transparency in the nuclear waste decision arena is being cast as an end in itself, rather than as a tool to shape the product of the assessment or decision process. It is not enough to permit knowledge of exactly what was done to arrive at a particular result, since at best, this only leads to reproducibility. The challenge is to expose why certain steps or assumptions were chosen for pursuit, and what suites of relevant steps or assumptions were rejected and why. It is also important to demonstrate that the trail to the product - the assessment or decision - is complete. In the nuclear waste management field, the complete scope of the assessment or decision process is not always fully exposed because it does not include the assumptions that initiated the process or the possible consequences of the product. In both instances, this failure can serve to limit the steps or assumptions pursued in the process. This paper will describe and discuss examples from the nuclear waste management field and the U.S. high-level nuclear waste program that illustrate the need for transparency, but also demonstrate that transparency does not always lead to an acceptable product.

  5. Transparent doesn't always make it right

    International Nuclear Information System (INIS)

    Frishman, S.

    1999-01-01

    The increasing drive for transparency in risk assessment, performance assessment, and decision-making in the controversial area of nuclear waste management has its foundation in the desire to foster the assumption that, if the outcome of the process is a clear result of the fully exposed contributory elements, then that outcome must be accepted as correct. This is in stark contrast to the general need for transparency in any analysis or decision process - to give the outcome credibility. Transparency in the nuclear waste decision arena is being cast as an end in itself, rather than as a tool to shape the product of the assessment or decision process. It is not enough to permit knowledge of exactly what was done to arrive at a particular result, since at best, this only leads to reproducibility. The challenge is to expose why certain steps or assumptions were chosen for pursuit, and what suites of relevant steps or assumptions were rejected and why. It is also important to demonstrate that the trail to the product - the assessment or decision - is complete. In the nuclear waste management field, the complete scope of the assessment or decision process is not always fully exposed because it does not include the assumptions that initiated the process or the possible consequences of the product. In both instances, this failure can serve to limit the steps or assumptions pursued in the process. This paper will describe and discuss examples from the nuclear waste management field and the U.S. high-level nuclear waste program that illustrate the need for transparency, but also demonstrate that transparency does not always lead to an acceptable product

  6. Lanthanum Nitrate As Electrolyte Additive To Stabilize the Surface Morphology of Lithium Anode for Lithium-Sulfur Battery.

    Science.gov (United States)

    Liu, Sheng; Li, Guo-Ran; Gao, Xue-Ping

    2016-03-01

    Lithium-sulfur (Li-S) battery is regarded as one of the most promising candidates beyond conventional lithium ion batteries. However, the instability of the metallic lithium anode during lithium electrochemical dissolution/deposition is still a major barrier for the practical application of Li-S battery. In this work, lanthanum nitrate, as electrolyte additive, is introduced into Li-S battery to stabilize the surface of lithium anode. By introducing lanthanum nitrate into electrolyte, a composite passivation film of lanthanum/lithium sulfides can be formed on metallic lithium anode, which is beneficial to decrease the reducibility of metallic lithium and slow down the electrochemical dissolution/deposition reaction on lithium anode for stabilizing the surface morphology of metallic Li anode in lithium-sulfur battery. Meanwhile, the cycle stability of the fabricated Li-S cell is improved by introducing lanthanum nitrate into electrolyte. Apparently, lanthanum nitrate is an effective additive for the protection of lithium anode and the cycling stability of Li-S battery.

  7. Transparency in nanophotonic quantum wires

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mahi R [Department of Physics and Astronomy, University of Western Ontario, London N6A 3K7 (Canada)

    2009-03-28

    We have studied the quantum optics of a photonic quantum nanowire doped with an ensemble of three-level nanoparticles. The wire is made from two photonic crystals A and B. Crystal A is embedded within crystal B and acts as a photonic nanowire. It is considered that the conduction band of crystal A lies below that of crystal B. As a result, photons are confined in crystal A and are reflected from crystal B. The bound states of the confined photons are calculated using the transfer matrix method. It is found that the number of bound states in the wire depends on the size of the wire and the energy difference between the conduction band extrema of crystals A and B. The absorption coefficient of the system has also been calculated using the Schroedinger equation method. It is considered that the nanoparticles interact with the photonic bound states. Numerical simulations show that when one of the resonance energies lies near the bound state, the system becomes transparent. However, when the resonance energy lies away from the bound state the crystal reverts to an absorbing state. Similarly, when the radius of the dielectric spheres is changed the location of the transparency peak is shifted. This means that the present system can be switched between two states by changing the size of the wire and the transition energy. These findings can be used to make new types of optical devices.

  8. Transparency in nanophotonic quantum wires

    International Nuclear Information System (INIS)

    Singh, Mahi R

    2009-01-01

    We have studied the quantum optics of a photonic quantum nanowire doped with an ensemble of three-level nanoparticles. The wire is made from two photonic crystals A and B. Crystal A is embedded within crystal B and acts as a photonic nanowire. It is considered that the conduction band of crystal A lies below that of crystal B. As a result, photons are confined in crystal A and are reflected from crystal B. The bound states of the confined photons are calculated using the transfer matrix method. It is found that the number of bound states in the wire depends on the size of the wire and the energy difference between the conduction band extrema of crystals A and B. The absorption coefficient of the system has also been calculated using the Schroedinger equation method. It is considered that the nanoparticles interact with the photonic bound states. Numerical simulations show that when one of the resonance energies lies near the bound state, the system becomes transparent. However, when the resonance energy lies away from the bound state the crystal reverts to an absorbing state. Similarly, when the radius of the dielectric spheres is changed the location of the transparency peak is shifted. This means that the present system can be switched between two states by changing the size of the wire and the transition energy. These findings can be used to make new types of optical devices.

  9. Nuclear transparency: the French example

    International Nuclear Information System (INIS)

    Phuc Tran Dai

    2016-01-01

    In France nuclear industry is from far the industrial sector that has set the most numerous commissions that allow a dialogue with the public in order to favor transparency. There are 4 local structures of information: -)there are 38 Local Committees of Information (CLI) associated with nuclear facilities, -) the Information Committees (CI) associated with secret nuclear facilities, -) the Follow-up Committees (CSS) for facilities dedicated to the processing of wastes, and the Committees for the prevention of industrial pollution (SPPPI). These committees involve numerous actors: public service, industrialists, supervisory authorities, elected representatives, employee representatives, members of associations and residents living nearby. Since 2000, 10 national public hearings around the 'atom' have been organized by the CNDP (National Commission for Public Consultation). Most actors of the nuclear industry allow residents living nearby to visit their installations, EDF ranks 3 as the company most visited with 400.000 people a year. Following the nuclear example the French chemical industry progressively moves toward more transparency. (A.C.)

  10. Tunable Broadband Nanocarbon Transparent Conductor by Electrochemical Intercalation.

    Science.gov (United States)

    Wan, Jiayu; Xu, Yue; Ozdemir, Burak; Xu, Lisha; Sushkov, Andrei B; Yang, Zhi; Yang, Bao; Drew, Dennis; Barone, Veronica; Hu, Liangbing

    2017-01-24

    Optical transparent and electrical conducting materials with broadband transmission are important for many applications in optoelectronic, telecommunications, and military devices. However, studies of broadband transparent conductors and their controlled modulation are scarce. In this study, we report that reversible transmittance modulation has been achieved with sandwiched nanocarbon thin films (containing carbon nanotubes (CNTs) and reduced graphene oxide (rGO)) via electrochemical alkali-ion intercalation/deintercalation. The transmittance modulation covers a broad range from the visible (450 nm) to the infrared (5 μm), which can be achieved only by rGO rather than pristine graphene films. The large broadband transmittance modulation is understood with DFT calculations, which suggest a decrease in interband transitions in the visible range as well as a reduced reflection in the IR range upon intercalation. We find that a larger interlayer distance in few-layer rGO results in a significant increase in transparency in the infrared region of the spectrum, in agreement with experimental results. Furthermore, a reduced plasma frequency in rGO compared to few-layer graphene is also important to understand the experimental results for broadband transparency in rGO. The broadband transmittance modulation of the CNT/rGO/CNT systems can potentially lead to electrochromic and thermal camouflage applications.

  11. Narrative Transparency: Adopting a Rhetorical Stance

    DEFF Research Database (Denmark)

    Arnould, Eric; Press, Melea

    2014-01-01

    In this paper, we look at how alternative marketing organisations communicate transparency in a climate of generalised risk and scepticism. We contrast the traditional numeric approach to transparency, which involves auditing and third-party certifications; with an alternative approach that we call...... narrative transparency. Central to narrative transparency is an emphasis on stake-holder dialogue and an invitation to stake-holders to play the role of auditor. This article illustrates how alternative marketing organisations engage in rhetorical tactics central to a narrative approach, to communicate...... transparency to their stakeholders. These rhetorical tactics include persona, allegory, consumer sovereignty and enlightenment. Community supported agriculture programmes from across the United States are the context for this study. Findings enrich discussions about best practices for transparency...

  12. Method of producing a solution of radioactive lanthanum-140 from radioactive barium-140 in an isotope generator and installation to carry out the method

    International Nuclear Information System (INIS)

    Akerman, K.; Jacobs, G.; Sauerwein, K.

    1979-01-01

    A method of separating radioactive lanthanum-140 from radioactive Ba-140 is proposed. The lanthanum-140 will be washed out of a sulphate precipitate and separated from Ba-140-sulphate by a granular filter mass of CaSO 4 and BaSO 4 . Details of the process are given. (UWI) [de

  13. Privacy-Preserving Transparency-Enhancing Tools

    OpenAIRE

    Pulls, Tobias

    2012-01-01

    Transparency is a key principle in democratic societies. For example, the public sector is in part kept honest and fair with the help of transparency through different freedom of information (FOI) legislations. In the last decades, while FOI legislations have been adopted by more and more countries worldwide, we have entered the information age enabled by the rapid development of information technology. This has led to the need for technological solutions that enhance transparency, for exampl...

  14. Towards Transparency in Finance and Governance

    OpenAIRE

    Tara Vishwanath; Daniel Kaufmann

    2003-01-01

    The study of transparency is increasingly a more topical, broadly relevant, but also more under-researched enterprise. The Asian financial crisis has highlighted not only the welfare consequences of financial sector transparency, sparking a series of yet unresolved debates, but has also linked this relatively narrow problem to the broader context of transparency in governance. Its significance has broadened geographically as well as across different sectors. It has been observed that curtailm...

  15. The Multi-Faceted Concept of Transparency

    OpenAIRE

    Forssbæck, Jens; Oxelheim, Lars

    2014-01-01

    Transparency has become a catchword and in the economic-political debate is often seen as a universal remedy for all sorts of problems. In this paper, we analyze and discuss the meaning and use of the concept of transparency in economic research. We look for common denominators across different areas where the concept is used, and find that transparency in essence is about reductions in information asymmetries, and therefore entails the transfer of information from a sender to a receiver. Tra...

  16. Liquidity and Transparency in Bank Risk Management

    OpenAIRE

    Lev Ratnovski

    2013-01-01

    Banks may be unable to refinance short-term liabilities in case of solvency concerns. To manage this risk, banks can accumulate a buffer of liquid assets, or strengthen transparency to communicate solvency. While a liquidity buffer provides complete insurance against small shocks, transparency covers also large shocks but imperfectly. Due to leverage, an unregulated bank may choose insufficient liquidity buffers and transparency. The regulatory response is constained: while liquidity buffers ...

  17. 3 CFR - Transparency and Open Government

    Science.gov (United States)

    2010-01-01

    ... system of transparency, public participation, and collaboration. Openness will strengthen our democracy... public. Government should be participatory. Public engagement enhances the Government's effectiveness and...

  18. A study on structural stability of bismuth titanate with lanthanum ...

    Indian Academy of Sciences (India)

    2017-05-13

    May 13, 2017 ... such as high leakage current and domain pinning, which leads to small remanent ... (La(NO3)3 · 6H2O) were dissolved in distilled water for 2 h with constant ... a thermocouple (K-type, maximum detection at 1200. ◦. C). The.

  19. Wave-mixing-induced transparency with zero phase shift in atomic vapors

    Science.gov (United States)

    Zhou, F.; Zhu, C. J.; Li, Y.

    2017-12-01

    We present a wave-mixing induced transparency that can lead to a hyper-Raman gain-clamping effect. This new type of transparency is originated from a dynamic gain cancellation effect in a multiphoton process where a highly efficient light field of new frequency is generated and amplified. We further show that this novel dynamic gain cancellation effect not only makes the medium transparent to a probe light field at appropriate frequency but also eliminates the probe field propagation phase shift. This gain-cancellation-based induced transparency holds for many potential applications on optical communication and may lead to effective suppression of parasitic Raman/hyper-Raman noise field generated in high intensity optical fiber transmissions.

  20. A case of lanthanum carbonate ingestion thought to be phlebosclerotic colitis on CT imaging and abdominal radiograph

    International Nuclear Information System (INIS)

    Harris, K.; Balcam, S.

    2017-01-01

    A male admitted in the early hours of the morning, complained of a four week, right sided, non-radiating, dull and intermittent abdominal pain. Imaging suggested a diagnosis of phlebosclerotic colitis which was later discounted when the patients' history of lanthanum carbonate ingestion was examined. Phlebosclerotic colitis mostly affects the Asian population, and its cause is still not known, but can be associated with specific radiographic features. Collections of lanthanum may confuse a diagnosis of phlebosclerotic colitis as well as other factors such as voxel errors, photon starvation and movement. - Highlights: • PC can be non-specific, its cause unknown, diagnosis is often delayed. • PC depends on specific radiographic features. • Lanthanum Carbonate can collect within the lumen and confuses diagnosis. • Voxel errors, photon starvation and patient movement can displace densities.

  1. Structural consideration with respect to the thermal stability of a new platinum supported lanthanum-alumina catalyst

    International Nuclear Information System (INIS)

    Oudet, F.; Bordes, E.; Courtine, P.; Maxant, G.; Lambert, C.; Guerlet, J.P.

    1987-01-01

    The influence of lanthanum aluminate, LaAlO 3 , on the thermal stability of both alumina and platinum supported alumina catalysts is investigated. In the case of alumina, the stabilization is interpreted in terms of structural coherence between δ-Al 2 O 3 and a three-fold superstructure of LaAlO 3 . The addition of LaAlO 3 , is shown to increase both the dispersion and the resistance to sintering of the platinum supported alumina catalyst. Moreover, lanthanum hexa-aluminate (La-β-Al 2 O 3 ) is present in the platinum catalyst fired at 1150 0 C. These observations are assumed to result for the epitaxial relations between platinum and the lanthanum-alumina support. 23 refs.; 8 figs.; 2 tabs

  2. Application of the Rietveld method in powders of strontium-doped lanthanum manganite calcined in different temperatures

    International Nuclear Information System (INIS)

    Chiba, R.; Vargas, R.A.; Martinez, L.G.; Andreoli, M.; Seo, E.S.M.

    2010-01-01

    The strontium-doped lanthanum manganite (LSM) is a ceramic material used as cathode in device called High Temperature Solid Oxide Fuel Cell. In this work, the LSM was synthesized by the citrate technique with the objective to get powders without the formation of secondary phases, such as lanthanum oxide and the lanthanum hydroxide, harmful for the functional performance of the device. The definitive calcination temperatures had been 700, 900 and 1100 deg C, due the decomposition of the polymeric precursors to present stabilization from 480 deg C. The analysis by X-ray diffraction of the calcined powders in different temperatures shows the formation only of phase LSM of hexagonal crystalline structure, type pseudo-perovskite. Using the refinement of Rietveld was determined the parameters and volumes of unity cells, atomic positions and occupations. These results confirm that the chemical compositions obtained are similar to the nominal. (author)

  3. EDITORIAL: On display with transparent conducting films On display with transparent conducting films

    Science.gov (United States)

    Demming, Anna

    2012-03-01

    by a researcher in the early 1930s, 'It is obvious that if the dyes used for selective staining in ordinary microscopical work are supplemented by substances which cause a particular detail of the structure to fluoresce with a specific colour in ultraviolet light, then many strings will be added to the bow of the practical microscopist' [3]. More recently, emphasis on the role of plasmons—collective oscillations of electrons in nanoscale metal structures—has received considerable research attention. Plasmons enhance the local electromagnetic field and can lead to increased fluorescence rates from nearby fluorophores depending on the efficiency of the counteracting process, non-radiative transfer [4]. Flat ITO films have been used extensively in photovoltaic studies as transparent electrodes [5]. Over the past few years, nanowire structures have recently been used to increase the surface area of the interface between dye and oxide in dye-sensitized solar cells [6]. A collaboration of researchers in China and Australia has recently extended the innovation of the nanowire structure to the ITO electrode [7]. Using cyclic voltammetry the researchers confirmed that using a 3D ITO-nanowire electrode significantly enhanced the reaction current. Despite its attractive properties, alternatives to ITO are now in high demand. The rise in devices requiring flat electronic displays has begun to overwhelm the legitimacy of using such a rare element as indium for transparent conducting films. ITO is also brittle, causing problems for flexible displays. Films of carbon nanotubes have been proposed for transparent conducting films but improvements to the sheet resistance are needed before they can compete with the performance of ITO. The effects of HNO3 treatment on the resistivity of carbon nanotube films has attracted some debate in the community, and stimulated the work of Ji-Beom Yoo and colleagues in Korea [8]. Their results suggest that p-type doping has a larger effect on

  4. Transparency and public value : Analyzing the transparency practices and value creation of public utilities

    NARCIS (Netherlands)

    Douglas, S.C.; Meijer, A.J.

    2016-01-01

    This article examines to what extent transparency is a condition for the creation of public value. Transparency is usually narrowly defined as a tool for external stakeholders to monitor the internal workings of an organization, but public value management positions transparency as a broader

  5. Atomically Bonded Transparent Superhydrophobic Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Aytug, Tolga [ORNL

    2015-08-01

    Maintaining clarity and avoiding the accumulation of water and dirt on optically transparent surfaces such as US military vehicle windshields, viewports, periscope optical head windows, and electronic equipment cover glasses are critical to providing a high level of visibility, improved survivability, and much-needed safety for warfighters in the field. Through a combination of physical vapor deposition techniques and the exploitation of metastable phase separation in low-alkali borosilicate, a novel technology was developed for the fabrication of optically transparent, porous nanostructured silica thin film coatings that are strongly bonded to glass platforms. The nanotextured films, initially structurally superhydrophilic, exhibit superior superhydrophobicity, hence antisoiling ability, following a simple but robust modification in surface chemistry. The surfaces yield water droplet contact angles as high as 172°. Moreover, the nanostructured nature of these coatings provides increased light scattering in the UV regime and reduced reflectivity (i.e., enhanced transmission) over a broad range of the visible spectrum. In addition to these functionalities, the coatings exhibit superior mechanical resistance to abrasion and are thermally stable to temperatures approaching 500°C. The overall process technology relies on industry standard equipment and inherently scalable manufacturing processes and demands only nontoxic, naturally abundant, and inexpensive base materials. Such coatings, applied to the optical components of current and future combat equipment and military vehicles will provide a significant strategic advantage for warfighters. The inherent self-cleaning properties of such superhydrophobic coatings will also mitigate biofouling of optical windows exposed to high-humidity conditions and can help decrease repair/replacement costs, reduce maintenance, and increase readiness by limiting equipment downtime.

  6. Lead poisoning

    Science.gov (United States)

    ... drinking water in homes containing pipes that were connected with lead solder . Although new building codes require ... lead in their bodies when they put lead objects in their mouths, especially if they swallow those ...

  7. Lead Poisoning

    Science.gov (United States)

    Lead is a metal that occurs naturally in the earth's crust. Lead can be found in all parts of our ... from human activities such as mining and manufacturing. Lead used to be in paint; older houses may ...

  8. Transparent conductors based on microscale/nanoscale materials for high performance devices

    Science.gov (United States)

    Gao, Tongchuan

    Transparent conductors are important as the top electrode for a variety of optoelectronic devices, including solar cells, light-emitting diodes (LEDs), at panel displays, and touch screens. Doped indium tin oxide (ITO) thin films are the predominant transparent conductor material. However, ITO thin films are brittle, making them unsuitable for the emerging flexible devices, and suffer from high material and processing cost. In my thesis, we developed a variety of transparent conductors toward a performance comparable with or superior to ITO thin films, with lower cost and potential for scalable manufacturing. Metal nanomesh (NM), hierarchical graphene/metal microgrid (MG), and hierarchical metal NM/MG materials were investigated. Simulation methods were used as a powerful tool to predict the transparency and sheet resistance of the transparent conductors by solving Maxwell's equations and Poisson's equation. Affordable and scalable fabrication processes were developed thereafter. Transparent conductors with over 90% transparency and less than 10 O/square sheet resistance were successfully fabricated on both rigid and flexible substrates. Durability tests, such as bending, heating and tape tests, were carried out to evaluate the robustness of the samples. Haze factor, which characterizes how blurry a transparent conductor appears, was also studied in-depth using analytical calculation and numerical simulation. We demonstrated a tunable haze factor for metal NM transparent conductors and analyzed the principle for tuning the haze factor. Plasmonic effects, excited by some transparent conductors, can lead to enhanced performance in photovoltaic devices. We systematically studied the effect of incorporating metal NM into ultrathin film silicon solar cells using numerical simulation, with the aid of optimization algorithms to reduce the optimization time. Mechanisms contributing to the enhanced performance were then identified and analyzed. Over 72% enhancement in short

  9. Growth and physico chemical characterization of lanthanum neodymium oxalate single crystals

    International Nuclear Information System (INIS)

    Raju, K.S.; John, Varughese; Ittyachen, M.A.

    1998-01-01

    Single crystals of lanthanum neodymium oxalate (LNO) are grown in sodium meta silicate gels, by the diffusion of a mixture of aqueous solutions of lanthanum nitrate and neodymium nitrate into the test tube having the set gel containing oxalic acid. The bluish pink coloured tabular crystals of LNO having well defined hexagonal basal planes appear either as foggy or clear, the latter at the greater depths inside the gel. The coloration of LNO visually observed is evidenced in UV-visible spectrum, by the revelation of well pronounced characteristic peaks in the visible region (500-900 nm). X-ray diffraction (XRD) of powdered LNO is ordered, meaning crystalline in nature, besides its isostructurality with similarly grown lanthanum samarium oxalate crystals. The single crystallinity of LNO is established by its oscillation XRD pattern. Thermogravimetric analysis (TGA) and differential scanning colorimetry (DSC) support that LNO loses water of crystallization around 120 degC and CO and CO 2 around 350-450 degC, while the infrared absorption (IR) spectrum of LNO establishes the presence of oxalate (C 2 O 4 ) 2- ions. Energy dispersive x-ray analysis (EDAX) confirms the presence of La and Nd in the sample. X-ray photoelectron spectroscopic (XPS) studies of LNO establish the presence of La and Nd in their respective oxide states. An empirical structure for LNO has been proposed on the basis of these findings. The smokiness in the foggy LNO crystal has been attributed due to the gel inclusion during the growth process. (author)

  10. Uranyl(VI) and lanthanum(III) complexes with functionalized macrocyclic and macroacyclic Schiff bases

    International Nuclear Information System (INIS)

    Aguiari, A.; Brianese, N.; Tamburini, S.; Vigato, P.A.

    1995-01-01

    Acyclic Schiff bases have been prepared by [2 + 1] condensation of 2,6-diformyl-4-chlorophenol and H 2 NCH 2 [CH 2 XCH 2 ] n CH 2 NH 2 (n =3D 0 H 2 -I; X =3D NH, S, O n =3D 1 H 2 -II...H 2 -IV; X =3D 0 n =3D 2 H 2 -V; X =3D 0 n =3D 3 H 2 -VI). The related uranlyl(VI) and lanthanum (III) complexes have bee synthesized by reaction by reaction of the preformed ligands with the appropriate salt or by the template procedure, in the presence of base. No base was employed in the preparation of lanthanum (III) complexes, La(H 2 -II)(NO 3 ) 3 , La(H 2 -IV)(NO 3 ) 3 where the Schiff bases coordinate as neutral chelate ligands. These acyclic complexes have been used for further condensation, and symmetric and asymmetric cyclic complexes have been obtained by their reaction with the polyamines H 2 NCH 2 [CH 2 XCH 2 ]nCH 2 NH 2 or with 4,4'-diaminodibenzo -18-crown-6. By reaction with 4-aminobenzo-15-crown-5 or 2-amino-methyl-15-crown-5, the same acyclic complexes give rise to functionalized complexes bearing crown-ether moieties. Analogously, the acyclic ligand H 3 -IXX, prepared by condensation of 2,6 diformyl-4-chlorophenol and tris(aminoethyl)amine, forms mono and homodinuclear lanthanum (III) complexes, which may undergo further condensation when reacted with primary functionalized amines. (authors). 42 refs., 2 figs., 2 schemes, 1 tab

  11. Self-assembly in lanthanum(III) and calcium(II) complexes of salicylaldimines derived from putrescine

    International Nuclear Information System (INIS)

    Pospieszna-Markiewicz, Izabela; Kaczmarek, Malgorzata T.; Kubicki, Maciej; Radecka-Paryzek, Wanda

    2008-01-01

    The one-step template reaction of salicylaldehyde with putrescine, a biogenic diamine, in the presence of lanthanum(III) or calcium(II) ions produces salicylaldimine complexes containing the N,N'-bis(salicylidene)-1,4-butanediamine ligand L as a result of the [2 + 1] Schiff base condensation. The X-ray diffraction studies of the lanthanum complex reveals an infinite [La 2 L 4 (NO 3 ) 6 ] ∞ polymeric structure based on networks of 10-coordinated La(III) nodes linked by bridging unionized ligands that use exclusively the oxygens as donor atoms with the nitrogen atoms not being involved in coordination

  12. Nuclear transparency in 90 deg.c.m. quasielastic A(p,2p) reactions

    International Nuclear Information System (INIS)

    Aclander, J.; Alster, J.; Kosonovsky, I.; Malki, A.; Mardor, I.; Mardor, Y.; Navon, I.; Piasetzky, E.; Asryan, G.; Barton, D.S.; Buktoyarova, N.; Bunce, G.; Carroll, A.S.; Gushue, S.; Makdisi, Y.I.; Roser, T.; Tanaka, M.; Averiche, Y.; Panebratsev, Y.; Shimanskiy, S.

    2004-01-01

    We summarize the results of two experimental programs at the Alternating Gradient Synchrotron of BNL to measure the nuclear transparency of nuclei measured in the A(p,2p) quasielastic scattering process near 90 deg. in the pp center of mass. The incident momenta varied from 5.9 to 14.4 GeV/c, corresponding to 4.8 2 2 . Taking into account the motion of the target proton in the nucleus, the effective incident momenta extended from 5.0 to 15.8 GeV/c. First, we describe the measurements with the newer experiment, E850, which had more complete kinematic definition of quasielastic events. E850 covered a larger range of incident momenta, and thus provided more information regarding the nature of the energy dependence of the nuclear transparency. In E850 the angular dependence of the nuclear transparency near 90 deg. and the nuclear transparency deuterons were studied. Second, we review the techniques used in an earlier experiment, E834, and show that the two experiments are consistent for the carbon data. E834 also determines the nuclear transparencies for lithium, aluminum, copper, and lead nuclei as well as for carbon. A determination of the (π + ,π + p) transparencies is also reported. We find for both E850 and E834 that the A(p,2p) nuclear transparency, unlike that for A(e,e ' p) nuclear transparency, is incompatible with a constant value versus energy as predicted by Glauber calculations. The A(p,2p) nuclear transparency for carbon and aluminum increases by a factor of two between 5.9 and 9.5 GeV/c incident proton momentum. At its peak the A(p,2p) nuclear transparency is ∼80% of the constant A(e,e ' p) nuclear transparency. Then the nuclear transparency falls back to a value at least as small as that at 5.9 GeV/c, and is compatible with the Glauber level again. This oscillating behavior is generally interpreted as an interplay between two components of the pN scattering amplitude; one short ranged and perturbative, and the other long ranged and strongly absorbed

  13. Transparent face recognition in the home environment

    NARCIS (Netherlands)

    Beumer, G.M.; Veldhuis, Raymond N.J.; Bazen, A.M.

    2004-01-01

    The BASIS project is about the secure application of transparent biometrics in the home environment. Due to transparency and home-setting requirements there is variance in appearance of the subject. An other problem which needs attention is the extraction of features. The quality of the extracted

  14. Transparency | IDRC - International Development Research Centre

    International Development Research Centre (IDRC) Digital Library (Canada)

    Transparency means openness. It allows Canadians to hold the government accountable through the proactive release of information on government activities, programs, policies, and services in formats that are easy to find, access, and use. Transparency is the key element in the Government of Canada's Commitment to ...

  15. 78 FR 14149 - 2012 Fiscal Transparency Report

    Science.gov (United States)

    2013-03-04

    .... Therefore, a published budget that does not include significant cash or non-cash resources, including... transparency is a critical element of effective public financial management, helps build market confidence, and sets the stage for economic sustainability. Transparency also provides a window into government budgets...

  16. Substantive Transparency Requirements in International Investment Law

    NARCIS (Netherlands)

    Pohl, Jens Hillebrand

    2017-01-01

    Few concepts in public governance evoke a more positive sentiment than transparency. Whether ultimately grounded in expediency or morality, transparency has emerged out of its municipal origins and been received at the international plane. This article examines the current state of evolution of the

  17. Transparency and Its Determinants at Colombian Universities

    Science.gov (United States)

    Flórez-Parra, Jesús Mauricio; López-Pérez, María Victoria; López-Hernández, Antonio Manuel

    2017-01-01

    Over the past decade, one of the demands upon public institutions, among which we find universities, has been for transparency and improvement of accountability. In this context, Colombian universities are introducing different methods of management and governance aimed at addressing the demands of society generally in relation to transparency and…

  18. 18 CFR 358.7 - Transparency rule.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Transparency rule. 358.7 Section 358.7 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION... Transparency rule. (a) Contemporaneous disclosure. (1) If a transmission provider discloses non-public...

  19. Single side Emitting Transparent OLED lamp

    NARCIS (Netherlands)

    Lifka, H.; Verschuren, C.A.; Bruls, D.M.; Tanase, C.

    2011-01-01

    Transparent OLEDs offer great potential for novel applications. Preferably, the light should be emitted from one side only. This can bedone to some extent by modifying electrode thicknesses, but at the cost of reduced transparency. Here, we demonstrate a new approach tomake single side emissive

  20. Transparency in netchains : evaluation and perspective

    NARCIS (Netherlands)

    Hofstede, G.J.; Schepers, H.E.; Trienekens, J.H.

    2003-01-01

    This paper was written for KLICT to evaluate the focus area Transparency in Netchains. It revisits the definitions and research agenda in the review paper with which the focal area started (Hofstede 2002). The definition of transparency has turned out to serve its purpose. The research has

  1. Can transparency be measured - a look ahead

    International Nuclear Information System (INIS)

    Jorle, A.

    2007-01-01

    The simple answer to this question is no. But if you define the expression and decide transparency actually is, the answer might be different. Transparency means different things in different places. In one country transparency meant almost total access to anything that a government authority has in its possession. In another country transparency is more strict access to certain decisions, decisions makers or documents written with the sole purpose of informing the public. What variables could be found in the word transparent, what is a transparent regulator? In this short presentation we will deal with some important settings or fundamental prerequisites for a regulator calling itself transparent. Perhaps we should look at them in order of importance. Some days it is difficult to do all at once. As a final point, if we as regulators wish to call ourselves transparent in a future with diminishing national borders, fast electronic communication and increasing world wide media impact, what does the world require from us as regulators? (author)

  2. Organizational Transparency in the Internet Industry

    DEFF Research Database (Denmark)

    Flyverbom, Mikkel

    as a panacea to concerns about privacy, organizational conduct and accountability, this paper explores the boundary work that goes into doing and promising transparency Using insights from the literature on transparency, ´sociologies of translations' and process approaches to organization, this paper captures...

  3. Analysis of the elements sputtered during the lanthanum implantation in stainless steels

    International Nuclear Information System (INIS)

    Ager, F.J.; Respaldiza, M.A.; Silva, M.F. da; Redondo, L.M.; Soares, J.C.

    1998-01-01

    The evidence of the modification of the surface structure of the AISI-304 stainless steel during the implantation of lanthanum makes the analysis of the sputtered elements very interesting. Those sputtered elements are deposited on a carbon sheet placed in front of the steel being implanted, and studied by means of RBS and PIXE, together with the implanted specimens. Besides, the protective effect of the implanted ions during the high temperature oxidation is also studied by those techniques together with XRD and thermogravimetric methods. (orig.)

  4. Deposition of Lanthanum Strontium Cobalt Ferrite (LSCF) Using Suspension Plasma Spraying for Oxygen Transport Membrane Applications

    Science.gov (United States)

    Fan, E. S. C.; Kesler, O.

    2015-08-01

    Suspension plasma spray deposition was utilized to fabricate dense lanthanum strontium cobalt ferrite oxygen separation membranes (OSMs) on porous metal substrates for mechanical support. The as-sprayed membranes had negligible and/or reversible material decomposition. At the longer stand-off distance (80 mm), smooth and dense membranes could be manufactured using a plasma with power below approximately 81 kW. Moreover, a membrane of 55 μm was observed to have very low gas leakage rates desirable for OSM applications. This thickness could potentially be decreased further to improve oxygen diffusion by using metal substrates with finer surface pores.

  5. Performance of planar single cell lanthanum gallate based solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Maffei, N.; Kuriakose, A.K. [Materials Technology Labs., CANMET, Natural Resources Canada, Ottawa, ON (Canada)

    1998-09-01

    A novel synthesis of high purity, single phase strontium-magnesium doped lanthanum gallate through a nitrate route is described. The prepared powder is formed into planar monolithic elements by uniaxial pressing followed by isostatic pressing and sintering. XRD analysis of the sintered elements reveal no detectable secondary phases. The performance of the electrolyte in solid oxide fuel cells (SOFC) with three different anode/cathode combinations tested at 700 C with respect to the J-V and power density is reported. The data show that the characteristics of this SOFC are strongly dependent on the particular anode/cathode system chosen. (orig.)

  6. Paramagnetic centers in two phases of manganese-doped lanthanum gallate

    Science.gov (United States)

    Vazhenin, V. A.; Potapov, A. P.; Guseva, V. B.; Artyomov, M. Yu.

    2009-05-01

    An EPR study of two phases of manganese-doped lanthanum gallate (with a first-order structural transition occurring at 430 K) has revealed Gd3+, Fe3+, and Mn4+ centers at room temperature and 438 K. The parameters of spin Hamiltonians are determined for the Gd3+, Fe3+, and Mn4+ rhombohedral centers in the high-temperature phase (with no other centers found here) and for the monoclinic center Gd3+ in the low-temperature phase. Both in the orthorhombic and in the rhombohedral phase, crystallographic twins (or ferroelastic domains) are observed.

  7. Lanthanum gallate substrates for epitaxial high-temperature superconducting thin films

    International Nuclear Information System (INIS)

    Sandstrom, R.L.; Giess, E.A.; Gallagher, W.J.; Segmueller, A.; Cooper, E.I.; Chisholm, M.F.; Gupta, A.; Shinde, S.; Laibowitz, R.B.

    1988-01-01

    We demonstrate that lanthanum gallate (LaGaO 3 ) has considerable potential as an electronic substrate material for high-temperature superconducting films. It provides a good lattice and thermal expansion match to YBa 2 Cu 3 O/sub 7-//sub x/, can be grown in large crystal sizes, is compatible with high-temperature film processing, and has a reasonably low dielectric constant (ε≅25) and low dielectric losses. Epitaxial YBa 2 Cu 3 O/sub 7-//sub x/ films grown on LaGaO 3 single-crystal substrates by three techniques have zero resistance between 87 and 91 K

  8. Performance of planar single cell lanthanum gallate based solid oxide fuel cells

    Science.gov (United States)

    Maffei, N.; Kuriakose, A. K.

    A novel synthesis of high purity, single phase strontium-magnesium doped lanthanum gallate through a nitrate route is described. The prepared powder is formed into planar monolithic elements by uniaxial pressing followed by isostatic pressing and sintering. XRD analysis of the sintered elements reveal no detectable secondary phases. The performance of the electrolyte in solid oxide fuel cells (SOFC) with three different anode/cathode combinations tested at 700°C with respect to the J- V and power density is reported. The data show that the characteristics of this SOFC are strongly dependent on the particular anode/cathode system chosen.

  9. Lanthanum gallate substrates for epitaxial high-temperature superconducting thin films

    Science.gov (United States)

    Sandstrom, R. L.; Giess, E. A.; Gallagher, W. J.; Segmuller, A.; Cooper, E. I.

    1988-11-01

    It is demonstrated that lanthanum gallate (LaGaO3) has considerable potential as an electronic substrate material for high-temperature superconducting films. It provides a good lattice and thermal expansion match to YBa2Cu3O(7-x), can be grown in large crystal sizes, is compatible with high-temperature film processing, and has a reasonably low dielectric constant and low dielectric losses. Epitaxial YBa2Cu3O(7-x) films grown on LaGaO3 single-crystal substrates by three techniques have zero resistance between 87 and 91 K.

  10. Solid-phase extraction (SPE) of Iron using Lanthanum Silicate ion exchange

    International Nuclear Information System (INIS)

    Kiarostami, V.; Husain, W.

    2002-01-01

    Solid-phase extraction (SPE) is gaining wide use as an effective and speedy technique which reduces solvent usage, disposal costs and extraction time. The analyte is adsorbed from solution onto a solid adsorbent, which is followed by elution of the analyte with a solvent appropriate for instrumental analysis. However, there is an increasing need for new selective adsorbents to expand the area of this technique. Lanthanum silicate ion exchanger, which shows unusual selectivity elements and in this study, it was employed to develop a SPE method for iron ion. Special experiments such as determination of distribution coefficient for iron ion in different solvent systems have been determined

  11. Cerium-modified Aurivillius-type sodium lanthanum bismuth titanate with enhanced piezoactivities

    International Nuclear Information System (INIS)

    Wang Chunming; Zhao Liang; Wang Jinfeng; Zheng Limei; Du Juan; Zhao Minglei; Wang Chunlei

    2009-01-01

    The electrical, piezoelectric and dielectric properties of cerium-modified Aurivillius-type sodium lanthanum bismuth titanate (Na 0.5 La 0.5 Bi 4 Ti 4 O 15 , NLBT) ceramics were investigated. It was found the piezoelectric activities of NLBT ceramics were significantly improved by cerium modification. The piezoelectric coefficient d 33 and Curie temperature T c for the 0.50 wt.% cerium-modified NLBT were found to be 29 pC/N and 573 deg. C, respectively. The reasons for piezoelectric activities improvement by cerium modification were given. A small dielectric abnormity was observed in NLBT ceramics, which can be suppressed by cerium modification.

  12. On isomorphous substitution of calcium by sodium and lanthanum in synthetic hydroxyapatite

    International Nuclear Information System (INIS)

    Get'man, E.I.; Kanyuka, Yu.V.; Loboda, S.N.

    1998-01-01

    Isomorphous substitution of calcium by sodium and lanthanum in synthetic hydroxyapatite Ca 5-2x La x (PO 4 ) 3 OH by x=0-2.5 within the temperature range 1100-800 deg C is studied through the roentgenophase analysis and IR-spectroscopy methods. It is established that singlephase solid solutions are formed in the area of x≥0.4 by a≤0.4 there exist phases with LaPO 4 , LaNa 6 (PO 4 ) 3 structures and unknown phase along with solid solution of the apatite structure

  13. Simultaneous determination of dopamine, uric acid and nitrite using carboxylated graphene oxide/lanthanum modified electrode

    International Nuclear Information System (INIS)

    Ye, Fengying; Feng, Chenqi; Jiang, Jibo; Han, Sheng

    2015-01-01

    Highlights: • The carboxylated graphene oxide/lanthanum-modified glassy carbon electrode (GO-COOLa/GCE) was successfully utilized for the simultaneous detection and quantification of DA, UA and NO 2 − . • Combining the benefits of carboxylated graphene oxide and lanthanum, the modified sensor displayed large peak separations, long linear ranges and low detection limits for simultaneously detecting DA, UA and NO 2 − . • The GO-COOLa/GCE electrode showed well stability, good repeatability, rapid response, and high catalytic performance toward the oxidations of DA, UA and NO 2 − . - Abstract: A bare glassy carbon electrode (GCE) was reformed by carboxylated graphene oxide/lanthanum, and the modified electrode, called GO-COOLa/GCE, was fabricated for simultaneously detecting dopamine (DA), uric acid (UA) and nitrite (NO 2 − ) by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and amperometry. Several factors which affected the electrocatalytic activity of the GO-COOLa/GCE electrode, such as the effect of pH, scan rate and concentration were studied. Due to the combination of carboxylated graphene oxide and lanthanum ions, the GO-COOLa/GCE sensor showed rapid response, excellent selectivity and high catalytic performance toward the electrooxidation of DA, UA and NO 2 − . In optimized conditions, two linear response ranges for determining DA were obtained over ranges of 0.01-1.96×10 2 μM and 1.96×10 2 -1.23×10 3 μM with detection limit of 0.018 μM (S/N = 3). And the responses of the GO-COOLa/GCE electrode for UA and NO 2 − were linear in the region of 1-1.53×10 3 μM and 1-2.75×10 3 μM with detection limits of 0.058 μM and 0.070 μM, respectively. Furthermore, this reformed electrode was successfully used to the detection of DA, UA and NO 2 − in real urine and serum samples, showing its promising application in the electroanalysis of real samples.

  14. Relaxation features of the Young's modulus and internal friction of lanthanum

    International Nuclear Information System (INIS)

    Bodryakov, V.Yu.

    1993-01-01

    E Young module and Q -1 inner friction of polycrystalline lanthanum specimens are studied comprehensively within 4.2-420 K temperature range using bend autovibrations of a specimen represented by a thin rod within ∼ 1-2 kHz frequency range. Three maximums of relaxation nature innner friction are detected under ∼ 380-410, 250-270 and 90-120 K temperatures with 0.29, 0.21 and 0.02 eV activation energies, respectively, on Q -1 (T) curves. Maximums of inner friction are accompanied by peculiarities of E(T) Young module behaviour. 21 refs., 3 figs., 2 tabs

  15. Size effects of polycrystalline lanthanum modified Bi4Ti3O12 thin films

    International Nuclear Information System (INIS)

    Simoes, A.Z.; Riccardi, C.S.; Cavalcante, L.S.; Gonzalez, A.H.M.; Longo, E.; Varela, J.A.

    2008-01-01

    The film thickness dependence on the ferroelectric properties of lanthanum modified bismuth titanate Bi 3.25 La 0.75 Ti 3 O 12 was investigated. Films with thicknesses ranging from 230 to 404 nm were grown on platinum-coated silicon substrates by the polymeric precursor method. The internal strain is strongly influenced by the film thickness. The morphology of the film changes as the number of layers increases indicating a thickness dependent grain size. The leakage current, remanent polarization and drive voltage were also affected by the film thickness

  16. Evaluating of electronic structure of Lanthanum chromite under doping of divalent ion using density functional theory

    International Nuclear Information System (INIS)

    Saievar, E.; Gharleghi, A.

    2006-01-01

    Doping Calcium in Lanthanum site of LaCrO 3 compound increasing the density of states in valance band and decreasing the band gap width because of increases of S electrons in valance band and variety of interaction energies from Cr +3 -Cr +4 couple in valance band. We have used Wien2k software for evaluating this mechanisms. Using of 0.25 percent of dopant and a kind of the space group of cell, let us to use one cell in calculations. We have used GGA approximation in this calculations.

  17. Lanthanum triflate triggered synthesis of tetrahydroquinazolinone derivatives of N-allyl quinolone and their biological assessment

    Directory of Open Access Journals (Sweden)

    Jardosh Hardik H.

    2012-01-01

    Full Text Available A series of 24 derivatives of tetrahydroquinazolinone has been synthesized by one-pot cyclocondensation reaction of N-allyl quinolones, cyclic β-diketones and (thiourea/N-phenylthiourea in presence of lanthanum triflate catalyst. This methodology allowed us to achieve the products in excellent yield by stirring at room temperature. All the synthesized compounds were investigated against a representative panel of pathogenic strains using broth microdilution MIC (minimum inhibitory concentration method for their in vitro antimicrobial activity. Amongst these sets of heterocyclic compounds 5h, 6b, 6h, 5f, 5l, 5n and 6g found to have admirable activity.

  18. Study of binding properties of lanthanum to wheat roots by INAA

    International Nuclear Information System (INIS)

    Zhang, Z.Y.; Li, F.L.; Xiao, H.Q.; Chai, Z.F.; Xu, L.; Liu, N.

    2004-01-01

    Chemical behavior of lanthanum in root tips excized from wheat seedlings growing at both promotional and inhibitory levels of LaCl 3 in culture solutions was investigated by a sequential leaching procedure combined with instrumental neutron activation analysis. The results indicate that most of La exists in non-exchangeable species and the binding of La 3+ to the root tips is extremely stable. The root tips during growing at the inhibitory level of LaCl 3 absorb much more La than those at the promotional level. However, the La proportion in each fraction is similar for both groups. (author)

  19. Transparency, price-dependent demand and product variety

    OpenAIRE

    Gu, Yiquan; Wenzel, Tobias

    2010-01-01

    This paper revisits the relationship between transparency on the consumer side and product variety as analyzed in Schultz (2009). We identify two welfare effects of transparency. More transparency decreases price-cost margins which is beneficial forwelfare. On the other hand, more transparency reduces variety which can be positive or negative for welfare. Overall, more transparency is always welfareimproving.

  20. The impact of records management system in transparency of public administrations: Transparency by design

    Directory of Open Access Journals (Sweden)

    Agustí Cerrillo Martínez

    2018-05-01

    Full Text Available Records management system has a great impact in the improvement of transparency in public administration. Transparency by design refers to the inclusion of transparency duties stated by legislation in force in the records’ life cycle in a way that it guarantees citizens effective access to public information. In this paper, the changes that public administrations have to propel in their records management systems to improve public transparency and to make easy access to information are analysed. In particular, as a case study, provisions made by Law 19/2014, of December 29, on Transparency, Access to Public Information and Good Governance of Catalonia are explored.

  1. Making metals transparency for white light by surface plasmons

    Science.gov (United States)

    Peng, Ru-Wen; Huang, Xian-Rong; Fan, Ren-Hao; Li, Jia; Hu, Qing; Wang, Mu

    2012-02-01

    We demonstrate both experimentally and theoretically that metallic gratings consisting of narrow slits become transparent for extremely broad bandwidths under oblique incidence. This phenomenon can be explained by a concrete picture in which the incident wave drives free electrons on the conducting surfaces and part of the slit walls to form surface plasmons (SPs). The SPs then propagate on the slit walls but are abruptly discontinued by the bottom edges to form oscillating charges that emit the transmitted wave. This picture explicitly demonstrates the conversion between light and SPs and indicates clear guidelines for enhancing SP excitation and propagation. Making structured metals transparent may lead to a variety of applications. References: Xian-Rong Huang, Ru-Wen Peng, and Ren-Hao Fan, Phys. Rev. Lett. (2010)105, 243901; and Ren-Hao Fan, Ru-Wen Peng, Xian-Rong Huang, Jia Li, Qing Hu, and Mu Wang, manuscript prepared(2011).

  2. Color transparency in incoherent electroproduction of ρ mesons off nuclei

    International Nuclear Information System (INIS)

    Nemchik, J.; Kopeliovich, B. Z.; Potashnikova, I. K.

    2013-01-01

    Color transparency (CT) phenomena in elastic electroproduction of vector mesons off nuclei are usually infected by the onset of coherence length (CL) effects. However, at low energies corresponding to the CLAS experiment at Jefferson Lab (JLab), one can study practically the net CT effects, since CL is much shorter than the nuclear radius. We investigate various manifestations of CT effects using rigorous quantum mechanical approach based on the path integral technique. We include also the effects of ρ meson decay inside the nucleus leading to a rise of the nuclear suppression towards small values of Q 2 . Motivated by the last CLAS data we predict the A, Q 2 and l c dependence of nuclear transparency for ρ 0 mesons produced incoherently off nuclei. We also perform predictions for expected signal of CT corresponding to the planned JLab upgrade to 12 GeV electron beam.

  3. Color transparency in incoherent electroproduction of {rho} mesons off nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Nemchik, J. [Institute of Experimental Physics SAS, Watsonova 47, 04001 Kosice, Slovakia and Czech Technical University, FNSPE, Brehova 7, 11519 Praque (Czech Republic); Kopeliovich, B. Z.; Potashnikova, I. K. [Departamento de Fisica y Centro de Estudios Subatomicos, Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile)

    2013-04-15

    Color transparency (CT) phenomena in elastic electroproduction of vector mesons off nuclei are usually infected by the onset of coherence length (CL) effects. However, at low energies corresponding to the CLAS experiment at Jefferson Lab (JLab), one can study practically the net CT effects, since CL is much shorter than the nuclear radius. We investigate various manifestations of CT effects using rigorous quantum mechanical approach based on the path integral technique. We include also the effects of {rho} meson decay inside the nucleus leading to a rise of the nuclear suppression towards small values of Q{sup 2}. Motivated by the last CLAS data we predict the A, Q{sup 2} and l{sub c} dependence of nuclear transparency for {rho}{sup 0} mesons produced incoherently off nuclei. We also perform predictions for expected signal of CT corresponding to the planned JLab upgrade to 12 GeV electron beam.

  4. Competition for transparency as a carrier of competition. Transparency needs in the European wholesale electricity markets

    International Nuclear Information System (INIS)

    Jong, Hanneke de; Hakvoort, Rudi

    2005-01-01

    This paper analyses different transparency aspects regarding European wholesale electricity markets and discusses transparency issues to be solved. In Europe, currently some progress has been made with respect to market transparency but transparency issues related to transmission, system operation and regulation have received little attention so far. Transmission system operators (TSOs) and regulatory authorities need certain market information in order to secure efficient competition. However, TSOs and regulatory authorities need to communicate themselves in order to facilitate competition and decrease uncertainty among market participants. Furthermore, considering ongoing market integration both TSOs and regulatory authorities must exchange information amongst themselves in order to facilitate coordination and monitoring activities. The effect of a higher level of transparency on effective competition is depended on two categories of transparency aspects: aspects that are related to transparency in the sense of open and adequate communication (perspicuity) and aspects that are related to the easiness to understand (clarity). Transparency includes both aspects. Pursuing overall harmonization of the European transparency level is important to fully profit from a higher level of (international) harmonization. Effective harmonization requires harmonization on all communication aspects. For Europe, with its many immature markets, the dilemma remains whether it is preferable to have less transparency with a high level of harmonization or to have a higher level of transparency but a lower level of harmonization. (Author)

  5. Transient birefringence effects in electromagnetically induced transparency

    International Nuclear Information System (INIS)

    Parshkov, O M

    2015-01-01

    We report the results of numerical modelling of transient birefringence that arises as a result of electromagnetically induced transparency on degenerate quantum transitions between the states with J = 0, 1 and 2 in the presence of the Doppler broadening of spectral lines. It is shown that in the case of a linearly polarised control field, the effect of transient birefringence leads to a decay of the input circularly polarised probe pulse into separate linearly polarised pulses inside a medium. In the case of a circularly polarised control field, the effect of transient birefringence manifests itself in a decay of the input linearly polarised probe pulse into separate circularly polarised pulses. It is shown that the distance that a probe pulse has to pass in a medium before decaying into subpulses is considerably greater in the first case than in the second. The influence of the input probe pulse power and duration on the process of spatial separation into individual pulses inside a medium is studied. A qualitative analysis of the obtained results is presented. (nonlinear optical phenomena)

  6. Structural properties of Fe-doped lanthanum gallate

    International Nuclear Information System (INIS)

    Mori, Kazuhiro; Fukunaga, Toshiharu; Shibata, Koji; Iwase, Kenji; Harjo, Stefanus; Hoshikawa, Akinori; Itoh, Keiji; Kamiyama, Takashi; Ishigaki, Toru

    2004-01-01

    Structural characteristics of Fe-doped LaGaO 3-δ were studied by differential scanning calorimeter, neutron and high-temperature X-ray powder diffraction measurements. It was found that a phase transition temperature increases in proportion to an amount of Fe. The crystal structure could be described as a low-temperature orthorhombic phase (Pnma) and a high-temperature rhombohedral one (R3-bar c), respectively. Lattice parameters and bond lengths between M (=Ga/Fe) and O are monotonically expand with increasing Fe-content on both orthorhombic and rhombohedral phases. This means that a substitution of Ga 3+ with Fe 3+ leads to an electronic configuration of t 2g 3 e g 2 (high-spin state, HS)

  7. The lanthanum gallate-based mixed conducting perovskite ceramics

    Science.gov (United States)

    Politova, E. D.; Stefanovich, S. Yu.; Aleksandrovskii, V. V.; Kaleva, G. M.; Mosunov, A. V.; Avetisov, A. K.; Sung, J. S.; Choo, K. Y.; Kim, T. H.

    2005-01-01

    The structure, microstructure, dielectric, and transport properties of the anion deficient perovskite solid solutions (La,Sr)(Ga,Mg,M)O3- with M=Fe, Ni have been studied. Substitution of iron and nickel for gallium up to about 20 and 40 at.% respectively, leads to the perovskite lattice contraction due to the cation substitutions by the transition elements. The transition from pure ionic to mixed ionic-electronic conductivity was observed for both the systems studied. Both the enhancement of total conductivity and increasing in the thermal expansion coefficient values has been proved to correlate with the increasing amount of weakly bounded oxygen species in the Fe or Ni-doped ceramics. The oxygen ionic conductivity has been estimated from the kinetic experiments using the dc-conductivity and dilatometry methods under the condition of the stepwise change of the atmosphere from nitrogen to oxygen.

  8. Structural properties of Fe-doped lanthanum gallate

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Kazuhiro [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan)]. E-mail: kmori@rri.kyoto-u.ac.jp; Fukunaga, Toshiharu [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Shibata, Koji [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Iwase, Kenji [Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801 (Japan); Harjo, Stefanus [Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801 (Japan); Hoshikawa, Akinori [Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801 (Japan); Itoh, Keiji [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Kamiyama, Takashi [Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801 (Japan); Ishigaki, Toru [Department of Materials Science and Engineering, Muroran Institute for Technology, Muroran 050-8585 (Japan)

    2004-10-30

    Structural characteristics of Fe-doped LaGaO{sub 3-{delta}} were studied by differential scanning calorimeter, neutron and high-temperature X-ray powder diffraction measurements. It was found that a phase transition temperature increases in proportion to an amount of Fe. The crystal structure could be described as a low-temperature orthorhombic phase (Pnma) and a high-temperature rhombohedral one (R3-bar c), respectively. Lattice parameters and bond lengths between M (=Ga/Fe) and O are monotonically expand with increasing Fe-content on both orthorhombic and rhombohedral phases. This means that a substitution of Ga{sup 3+} with Fe{sup 3+} leads to an electronic configuration of t{sub 2g}{sup 3}e{sub g}{sup 2} (high-spin state, HS)

  9. Structural properties of Fe-doped lanthanum gallate

    Science.gov (United States)

    Mori, Kazuhiro; Fukunaga, Toshiharu; Shibata, Koji; Iwase, Kenji; Harjo, Stefanus; Hoshikawa, Akinori; Itoh, Keiji; Kamiyama, Takashi; Ishigaki, Toru

    2004-10-01

    Structural characteristics of Fe-doped LaGaO3-δ were studied by differential scanning calorimeter, neutron and high-temperature X-ray powder diffraction measurements. It was found that a phase transition temperature increases in proportion to an amount of Fe. The crystal structure could be described as a low-temperature orthorhombic phase (Pnma) and a high-temperature rhombohedral one (R 3 bar c), respectively. Lattice parameters and bond lengths between M (=Ga/Fe) and O are monotonically expand with increasing Fe-content on both orthorhombic and rhombohedral phases. This means that a substitution of Ga3+ with Fe3+ leads to an electronic configuration of t2g3eg2 (high-spin state, HS).

  10. The structural change of lanthanum diiodide upon hydrogenation

    International Nuclear Information System (INIS)

    Ryazanov, M.; Simon, A.; Mattausch, Hj.; Kremer, R.K.

    2004-01-01

    Slowly heating LaI 2 under 1 atm hydrogen to 650 deg. C leads to LaI 2 H, analyzed as LaI 2 H 0.95(3) , accompanied by a structural change from tetragonal to hexagonal. Sharp reflections in the XRD pattern can be indexed in P6 3 /mmc with a=4.2158(7) A and c=15.508(3) A, however, diffuse reflections indicate a polytypic intergrowth of MoS 2 and NbS 2 type structures. The earlier determined miscibility gap between LaI 2 and LaI 2 H x (x∼0.5) is closely related to the change of the structure. The Pauli paramagnetism for LaI 2 , χ P = 43(2)x10 -6 cm 3 /mol, derived from measurements on LaI 2 and LaI 2 H is in good agreement with the value estimated from band structure calculations

  11. Transmission in Optically Transparent Core Networks

    Science.gov (United States)

    Kilper, Dan; Jensen, Rich; Petermann, Klaus; Karasek, Miroslav

    2007-03-01

    Call for Papers: Transmission in Optically Transparent Core Networks Guest Feature Editors Dan Kilper and Rich Jensen, Coordinating Associate Editors Klaus Petermann and Miroslav Karasek, Guest Feature Editors Submission deadline: 15 June 2007 Optically transparent networks in which optical transport signals are routed uninterrupted through multiple nodes have long been viewed as an important evolutionary step in fiber optic communications. More than a decade of research and development on transparent network technologies together with the requisite traffic growth has culminated in the recent deployment of commercial optically transparent systems. Although many of the traditional research goals of optical transmission remain important, optical transparency introduces new challenges. Greater emphasis is placed on system efficiency and control. The goal of minimizing signal terminations, which has been pursued through increasing reach and channel capacity, also can be realized through wavelength routing techniques. Rather than bounding system operation by rigid engineering rules, the physical layer is controlled and managed by automation tools. Many static signal impairments become dynamic due to network reconfiguration and transient fault events. Recently new directions in transmission research have emerged to address transparent networking problems. This special issue of the Journal of Optical Networking will examine the technologies and theory underpinning transmission in optically transparent core networks, including both metropolitan and long haul systems. Scope of Submission The special issue editors are soliciting high-quality original research papers related to transmission in optically transparent core networks. Although this does not include edge networks such as access or enterprise networks, core networks that have access capabilities will be considered in scope as will topics related to the interworking between core and edge networks. The core network

  12. Transparency in Global Environmental Governance: A Coming of Age?

    NARCIS (Netherlands)

    Gupta, A.

    2010-01-01

    This introductory article draws on the contributions to this special issue to consider the implications of a transparency turn in global environmental and sustainability governance. Three interrelated aspects are addressed: why transparency now? How is transparency being institutionalized? And what

  13. 76 FR 7522 - Federal Acquisition Regulation; Enhancing Contract Transparency

    Science.gov (United States)

    2011-02-10

    ... transparency while retaining the protection of information that should be considered in the contracting process... the need for transparency in Government contracting information and believe these recommendations... Regulation; Enhancing Contract Transparency AGENCY: Department of Defense (DoD), General Services...

  14. Thermoluminescent kinetic parameters of the perovskite, KMgF3, activated with lanthanum

    International Nuclear Information System (INIS)

    Sepulveda M, F.; Azorin N, J.; Rivera M, T.; Furetta, C.; Sanipoli, C.

    2004-01-01

    The thermoluminescent curves induced by the beta radiation in the perovskite KMgF 3 were investigated activated with lanthanum. The classic methods were used to determine the kinetic parameters (the kinetic order b, the activation energy E and the frequency of escape intent s) associated with the peaks of the thermoluminescent curve (Tl) in the KMgF 3 activated with lanthanum after the irradiation with beta rays. The method is based on the position of the thermoluminescent peaks, obtained of the temperature change of the peak in the maximum emission caused by the change in the heating rapidity to which the samples were measured. In this work, the samples in form of pellets were re cooked previously at 400 C during one hour before irradiating them with beta particles. The Tl measures were made with a Tl reader system using three different heating rapidities and storing the glow curves. To calculate the depth of the E traps and the frequency factor s, the parameters of the glow curve were determined experimentally of the shame of the glow curve by means of the mensuration of the shame of the maximum temperature of the peak, T M like a function of the heating rapidity. The results indicate that the values of the kinetic parameters are very near among if when they are obtained indistinctly of anyone of the different methods. (Author)

  15. Investigation of lanthanum- and neodymium ion interaction with potassium polyphosphate in aqueous solution

    International Nuclear Information System (INIS)

    Ezhova, Zh.A.; Tananaev, I.V.; Koval', E.M.

    1983-01-01

    A study was made on the interaction in the LaCl 3 -KPO 3 -H 2 O and NdCl 3 -KPO 3 -H 2 O systems at 0 deg C by methods of solubility of residual concentrations and measurement of the pH value. The formation of binary KLa 2 (PO 3 ) 7 x10H 2 O and KLa(PO 3 ) 4 X5H 2 O lanthanum- and potassium polyphosphates, as well as KNd 2 (PO 3 ) 7 X10H 2 O and KNd(PO 3 ) 4 X5H 2 O neodymium- apd potassiUm polyphasphates was established. Chemical, paper-chromatographic, infrared spectroscopic, X-ray diffraction and differential thermal analyses of the prepared compoUnds were conducted. Anhydrous binary lanthanum- and neodymium polyphosphates with potassium-=Kla(PO 3 ) 4 , KNd(PO 3 ) 4 , KLa 2 (PO 3 ) 7 and KNd 2 x(PO 3 ) 7 - eere prepared

  16. The origin of current blocking in interfacial conduction in Sr-doped lanthanum gallates

    Science.gov (United States)

    Park, Hee Jung

    2018-02-01

    The grain boundary transport of lanthanum gallate has been studied with various doping concentrations, and the origins of blocking on the grain boundary are compared. La1-xSrxGaO3 samples (x = 0.005, 0.01, 0.05 and 0.1) have been prepared and their bulk (grain) and grain boundary resistances been experimentally measured as a function of temperature (T: 200-550 °C) and oxygen partial pressure (Po2) using ac-impedance measurements. In addition, Hebb-Wagner polarization measurements have been conducted to investigate the electrical conductivity of minor charge carriers in the lanthanum gallates. The grain boundary resistance in the low-doped materials (x = 0.005 and 0.01) increases with increasing Po2 while in the highly-doped materials (x = 0.05, 0.1) it hardly depended on Po2. At lower concentrations conduction is mixed and at higher concentrations is found to be predominantly ionic conductivity. The space charge model successfully describes the mixed conduction at the grain boundary at low-doping, but does not explain the predominant ionic conductivity at high-doping. The origin of blocking at high-doping is explained by the crystallographic asymmetry of the grain boundary with respect to the bulk and/or Sr-segregation.

  17. Chemically produced nanostructured ODS-lanthanum oxide-tungsten composites sintered by spark plasma

    International Nuclear Information System (INIS)

    Yar, Mazher Ahmed; Wahlberg, Sverker; Bergqvist, Hans; Salem, Hanadi G.; Johnsson, Mats; Muhammed, Mamoun

    2011-01-01

    High purity W and W-0.9La 2 O 3 (wt.%) nanopowders were produced by a wet chemical route. The precursor was prepared by the reaction of ammonium paratungstate (APT) with lanthanum salt in aqueous solutions. High resolution electron microscopy investigations revealed that the tungstate particles were coated with oxide precipitates. The precursor powder was reduced to tungsten metal with dispersed lanthanum oxide. Powders were consolidated by spark plasma sintering (SPS) at 1300 and 1400 o C to suppress grain growth during sintering. The final grain size relates to the SPS conditions, i.e. temperature and heating rate, regardless of the starting powder particle size. Scanning electron microscopy revealed that oxide phases were mainly accumulated at grain boundaries while the tungsten matrix constituted of nanosized sub-grains. The transmission electron microscopy revealed that the tungsten grains consist of micron-scale grains and finer sub-grains. EDX analysis confirmed the presence of W in dispersed oxide phases with varying chemical composition, which evidenced the presence of complex oxide phases (W-O-La) in the sintered metals.

  18. Lanthanum chloride impairs spatial memory through ERK/MSK1 signaling pathway of hippocampus in rats.

    Science.gov (United States)

    Liu, Huiying; Yang, Jinghua; Liu, Qiufang; Jin, Cuihong; Wu, Shengwen; Lu, Xiaobo; Zheng, Linlin; Xi, Qi; Cai, Yuan

    2014-12-01

    Rare earth elements (REEs) are used in many fields for their diverse physical and chemical properties. Surveys have shown that REEs can impair learning and memory in children and cause neurobehavioral defects in animals. However, the mechanism underlying these impairments has not yet been completely elucidated. Lanthanum (La) is often selected to study the effects of REEs. The aim of this study was to investigate the spatial memory impairments induced by lanthanum chloride (LaCl3) and the probable underlying mechanism. Wistar rats were exposed to LaCl3 in drinking water at 0 % (control, 0 mM), 0.25 % (18 mM), 0.50 % (36 mM), and 1.00 % (72 mM) from birth to 2 months after weaning. LaCl3 considerably impaired the spatial learning and memory of rats in the Morris water maze test, damaged the synaptic ultrastructure and downregulated the expression of p-MEK1/2, p-ERK1/2, p-MSK1, p-CREB, c-FOS and BDNF in the hippocampus. These results indicate that LaCl3 exposure impairs the spatial learning and memory of rats, which may be attributed to disruption of the synaptic ultrastructure and inhibition of the ERK/MSK1 signaling pathway in the hippocampus.

  19. Structures, stabilities, and electronic properties for rare-earth lanthanum doped gold clusters

    International Nuclear Information System (INIS)

    Zhao, Ya-Ru

    2015-01-01

    The structures, stabilities, and electronic properties of rare-earth lanthanum doped gold La 2 Au n (n = 1-9) and pure gold Au n (n ≤ 11) clusters have been investigated by using density functional theory. The optimized geometries show that the lowest energy structures of La 2 Au n clusters favour the 3D structure at n ≥ 3. The lanthanum atoms can strongly enhance the stabilities of gold clusters and tend to occupy the most highly coordinated position. By analysing the gap, vertical ionization potential, and chemical hardness, it is found that the La 2 Au 6 isomer possesses higher stability for small-sized La 2 Au n clusters (n = 1-9). The charges in the La 2 Au n clusters transfer from La atoms to the Au n host. In addition, Wiberg bond indices analysis reveals that the intensity of different bonds of La 2 Au n clusters exhibits a sequence of La-La bond > La-Au bond > Au-Au bond.

  20. STRUCTURE AND THERMAL STABILITY OF THE BENZO-15-CROWN-5 WITH LANTHANUM (III BROMIDE COMPLEX

    Directory of Open Access Journals (Sweden)

    Muhammad Idiris Saleh

    2010-06-01

    Full Text Available The reaction of benzo-15-crown-5 (C14H20O5 ligand with La(NO33.7H2O in the presence of HBr has resulted in the production of an exotic sandwich complex, [LaC28H36Br4O10][3Br]. The crystal system is triclinic with space group P1, a = 12.5834(14 Å, b = 13.5816(16 Å, c = 13.8403(16 Å, a = 70.751(2°, b = 66.773(2° and g = 67.631(2°. The cation comprises of the lanthanum atom coordinated to two crowns via three oxygen atoms from each crown in a η3-sandwich fashion. The two phenyl groups of the crown are brominated. The La-OLigand bond lengths are between 2.857(7 and 2.949(7 Å. The trianion [3Br]3- is linear with Br-Br bond lengths of 2.518(2 and 2.560(2 Å respectively. The molecule is stabilized by intermolecular interactions of the type C-H...Br to form dimers and are arranged parallel to bc face.  Keywords: lanthanum, benzo-15-crown-5, hydrogen bonding, bromination, x-ray structure

  1. Preferable adsorption of phosphate using lanthanum-incorporated porous zeolite: Characteristics and mechanism

    Science.gov (United States)

    He, Yinhai; Lin, Hai; Dong, Yingbo; Wang, Liang

    2017-12-01

    The adsorbent, where lanthanum oxide was incorporated onto porous zeolite (La-Z), of preferable adsorption towards phosphate was prepared by hydrothermal synthesis. Based on pH effect results, La-Z would effectively sequestrate phosphate over wider pH range of 3.0-7.0, alkaline conditions were unfavorable for phosphate. The adsorption of phosphate was not significantly influenced by ionic strength and by coexisting anions of chloride, nitrate and sulfate but bicarbonate showed slightly greater negative effects, indicating La-Z possessed highly selectivity to phosphate. Adsorption of phosphate could be well fitted by pseudo-second-order model and the process was mainly controlled by intra-particle diffusion. Equilibrium adsorption demonstrated that Langmuir model was more suitable than Freundlich model for description phosphate adsorption and the adsorption capacity was 17.2 mg P g-1, which exhibited 95% utilization of incorporated La. Over 95% phosphate was eliminated in real effluent treatment when the dose was 2 g L-1. The underlying mechanism for phosphate capture was probed with Zeta potential and X-ray photoelectron spectroscope analysis, and the formation of La-P inner-sphere complexation was testified to be the dominant pathway. All the results suggested that the porous zeolite-supported lanthanum oxide can serve as a promising adsorbent for phosphate removal in realistic application.

  2. Lanthanum-modified bentonite: potential for efficient removal of phosphates from fishpond effluents.

    Science.gov (United States)

    Kurzbaum, Eyal; Raizner, Yasmin; Cohen, Oded; Rubinstein, Guy; Bar Shalom, Oded

    2017-06-01

    Adsorption has been suggested as an effective method for removing phosphates from agricultural wastewater effluents that contain relatively high phosphate concentrations. The present study focused on the use of a bentonite-lanthanum clay (Phoslock ® ) for reducing the dissolved phosphate concentration in fishpond effluents. Batch experiments with synthetic phosphate-spiked solutions and with fishpond effluents were performed in order to determine adsorption equilibrium isotherms and kinetics as well as to determine the efficiency of Phoslock ® in removing phosphate from these solutions. In the synthetic phosphate-spiked solution, the mean maximum phosphate adsorption capacity was 92 mg Phoslock ® /mg phosphate removal. A ratio of 50, 100, and 200 mg Phoslock ® /mg phosphate removal was found for complete phosphate removal from the fishpond effluents, where higher doses of Phoslock ® led to a faster removal rate (94% removal within the first 150 min). These results show that bentonite-lanthanum clay can be employed for designing a treatment process for efficient phosphate removal from fishpond effluents.

  3. Thermal stability and microstructure of catalytic alumina composite support with lanthanum species

    Science.gov (United States)

    Ozawa, Masakuni; Nishio, Yoshitoyo

    2016-09-01

    Lanthanum (La) modified γ-alumina composite was examined for application toward thermostable catalytic support at elevated temperature. La added alumina was prepared through an aqueous process using lanthanum (III) nitrate and then characterized by surface area measurement, X-ray powder diffraction (XRD), differential thermal analysis (DTA), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoemission spectroscopy (XPS) and surface desorption of CO2. It was found that the properties depended on the La content and heat treatment temperatures. The characterization of the surface, structural and chemical properties of La-Al2O3 showed the existence of a strong interaction between the La species and alumina via formation of new phase and modified surface in Al2O3 samples. LaAlO3 nanoparticle formed among alumina particles by the solid phase reaction of Al2O3 and La2O3. The increase of the surface basicity of La modified alumina was demonstrated using CO2 temperature programmed desorption experiments. The controlled surface interaction between La oxide and alumina provide the unique surface and structural properties of the resulting mixed oxides as catalysts and catalytic supports.

  4. Bordoni relaxation and magnetic transformation in cerium and cerium-lanthanum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Postnikov, V S; Polner, G L; Sharshakov, I M

    1975-11-01

    The internal friction in pure cerium and cerium-base alloys with 2.5 and 12 weight percent of lanthanum added at temperature ranging from 4.2 deg up to 77/sup 0/K is described. Amplitude-independent internal friction has been measured with an inverse torsion pendulum with a specimen oscillation frequency of 1-30 hz in vacuum not less than 1.10/sup -5/ torr. A temperature of the specimen has been determined with a capacitance-type sensor and a gas gage. A curve showing the dependence of internal friction upon a temperature of pure cerium has two distinct peaks; the first at 12.5/sup 0/K, the second at 45/sup 0/K. The 12.5/sup 0/K peak is accounted for by a transition of antiferromagnetic ..beta..-Ce into a paramagnetic state. The 45/sup 0/K peak is a Bordoni maximum. The paper describes an influence of additions, specimen oscillation frequency variations, deformation and annealing upon the peak behavor. Added lanthanum reduces not only a peak temperature but a height as well. Studies of the 45/sup 0/K peak have shown that its temperature location depends upon the specimen oscillation frequency. As the frequency increases the peak tends to a range of high temperatures which confirms its relaxation nature.

  5. Improved adaptation of test with lanthanum nitrate for the colorimetric estimation of acetate

    Energy Technology Data Exchange (ETDEWEB)

    Szumilo, T [Akademia Medyczna, Lublin (Poland)

    1976-01-01

    A colorimetric method for the determination of acetate based on the production of the blue complex between iodine and lanthanum alkaline acetate has been developed. Optimum concentrations of reagents (acetate, lanthanum nitrate, iodine and ammonia) as well as the volume of acetate were selected to achieve best colour intensity. Coloured complex was stabilized by dilution of reagent mixture with water to the final volume convenient for determinaton. Absorbance of the complex can be measured immediately after dilution and any changes can be observed during at least 15 minutes. Elevation of temperature over 60/sup 0/decreases absorbance. The method fulfills the Beer's law in the range 1,5-3,5 ..mu..moles of acetate, precision of the method 2/sup +/ = 3,7%. Apart from acetate - propionate and fluoroacetate complex is 620 nm, propionate complex - at 590 nm. Propionate complex displayed any relationship between concentration and absorbance. Potassium, sodium, lithium and barium acetates give the identical results as acetic acid, whereas zinc and cupric acetates failed to react. Other derivatives tested, e.g. chloroacetate, trichloroacetate, iodoacetate, chloroporpionate and butyrate are unable to form the coloured complexes. Many compounds interfere with the formation of acetate complex, therefore, in material containing impurities acetate can be determined after purificaton by means of described in literature methods.

  6. Electron paramagnetic resonance of V4+ in the lanthanum and cerium orthophosphates

    International Nuclear Information System (INIS)

    Lima, J.C. de.

    1983-11-01

    The Electron Paramagnetic Resonance (EPR) spectrum of V 4+ was investigated in polycrystalline samples of lanthanum orthophosphate (LaPO 4 ) and cerium orthophosphate (CePO 4 ) doped with 0.2 wt % vanadium pentoxide (V 2 O 5 ). Measurements were performed at room temperature and 9.5 GHz. In LaPO 4 , two non-equivalent axial sites were inferred from the EPR spectra. The most stable of these two sites is probably substitutional. In CePO 4 , a single axial spectrum was observed. It was attributed to V 4+ in substitutional sites. A central, wide line was also seen; it was attributed to ferromagnetic clusters of vanadium ions. Photoacoustic absorption spectra were also recorded for the two compounds. The EPR and photoacoustic absorption data, when analyzed using the molecular orbital theory, show that for both lanthanum orthophosphate and cerium orthophosphate the ground orbital (d sub(x) 2 sub(-y) 2) of the unpainred electron is purely ionic, while the excited orbitals d sub(xy) and d sub(xz,yz) are partly covalent. The degree of covalency is higher for the d sub(xy) orbital. Finally, it should be pointed out that part of the theory used for the interpretation of the EPR and photoacoustic absorption spectra (study of the ligand field splitting of a d orbital in a site of distorted capped antiprism structure) was developed by the author in the present work and is therefore an original contribution. (Author) [pt

  7. Lanthanum germanate-based apatites as electrolyte for SOFCs

    Energy Technology Data Exchange (ETDEWEB)

    Marrero-Lopez, D.; Diaz-Carrasco, P.; Ramos-Barrado, J.R. [Departamento de Fisica Aplicada I, Laboratorio de Materiales y Superficies (Unidad Asociada al C.S.I.C.), Universidad de Malaga, 29071 Malaga (Spain); Pena-Martinez, J. [Instituto de Energias Renovables, Parque Tecnologico, Universidad de Castilla La Mancha, 02006 Albacete (Spain); Ruiz-Morales, J.C. [Departamento de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain)

    2011-02-15

    Germanate apatites with composition La{sub 10-x}Ge{sub 5.5}Al{sub 0.5}O{sub 26.75-3x/2} have been evaluated for the first time as possible electrolytes for solid oxide fuel cells (SOFCs). Different electrode materials have been considered in this study, i.e. manganite, ferrite, nickelates and cobaltite as cathode materials; and NiO-CGO composite and chromium-manganite as anodes. The chemical compatibility and electrochemical performance of these electrodes with La{sub 9.8}Ge{sub 5.5}Al{sub 0.5}O{sub 26.45} have been studied by X-ray powder diffraction (XRPD) and impedance spectroscopy. The XRPD analysis did not reveal appreciable bulk reactivity with the formation of reaction products between the germanate electrolyte and these electrodes up to 1,200 C. However, a significant cation interdiffusion was observed by energy dispersive spectroscopy (EDS) at the electrode/electrolyte interface, which leads to a significant decrease of the performance of these electrodes. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. The lanthanum gallate-based mixed conducting perovskite ceramics

    International Nuclear Information System (INIS)

    Politova, E.D.; Stefanovich, S.Yu.; Aleksandrovskii, V.V.; Kaleva, G.M.; Mosunov, A.V.; Avetisov, A.K.; Sung, J.S.; Choo, K.Y.; Kim, T.H.

    2005-01-01

    The structure, microstructure, dielectric, and transport properties of the anion deficient perovskite solid solutions (La,Sr)(Ga,Mg,M)O 3-δ with M=Fe, Ni have been studied. Substitution of iron and nickel for gallium up to about 20 and 40 at.% respectively, leads to the perovskite lattice contraction due to the cation substitutions by the transition elements. The transition from pure ionic to mixed ionic-electronic conductivity was observed for both the systems studied. Both the enhancement of total conductivity and increasing in the thermal expansion coefficient values has been proved to correlate with the increasing amount of weakly bounded oxygen species in the Fe or Ni-doped ceramics. The oxygen ionic conductivity has been estimated from the kinetic experiments using the dc-conductivity and dilatometry methods under the condition of the stepwise change of the atmosphere from nitrogen to oxygen. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. The lanthanum gallate-based mixed conducting perovskite ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Politova, E.D.; Stefanovich, S.Yu.; Aleksandrovskii, V.V.; Kaleva, G.M.; Mosunov, A.V.; Avetisov, A.K. [L.Ya. Karpov Institute of Physical Chemistry, Vorontsovo pole 10, 105064 Moscow (Russian Federation); Sung, J.S.; Choo, K.Y.; Kim, T.H. [Korea Institute of Energy Research, 71-2 Jang-dong Yooseong, Daejeon (Korea)

    2005-01-01

    The structure, microstructure, dielectric, and transport properties of the anion deficient perovskite solid solutions (La,Sr)(Ga,Mg,M)O{sub 3-{delta}} with M=Fe, Ni have been studied. Substitution of iron and nickel for gallium up to about 20 and 40 at.% respectively, leads to the perovskite lattice contraction due to the cation substitutions by the transition elements. The transition from pure ionic to mixed ionic-electronic conductivity was observed for both the systems studied. Both the enhancement of total conductivity and increasing in the thermal expansion coefficient values has been proved to correlate with the increasing amount of weakly bounded oxygen species in the Fe or Ni-doped ceramics. The oxygen ionic conductivity has been estimated from the kinetic experiments using the dc-conductivity and dilatometry methods under the condition of the stepwise change of the atmosphere from nitrogen to oxygen. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Understanding surface structure and chemistry of single crystal lanthanum aluminate

    KAUST Repository

    Pramana, Stevin S.

    2017-03-02

    The surface crystallography and chemistry of a LaAlO3 single crystal, a material mainly used as a substrate to deposit technologically important thin films (e.g. for superconducting and magnetic devices), was analysed using surface X-ray diffraction and low energy ion scattering spectroscopy. The surface was determined to be terminated by Al-O species, and was significantly different from the idealised bulk structure. Termination reversal was not observed at higher temperature (600 °C) and chamber pressure of 10−10 Torr, but rather an increased Al-O occupancy occurred, which was accompanied by a larger outwards relaxation of Al from the bulk positions. Changing the oxygen pressure to 10−6 Torr enriched the Al site occupancy fraction at the outermost surface from 0.245(10) to 0.325(9). In contrast the LaO, which is located at the next sub-surface atomic layer, showed no chemical enrichment and the structural relaxation was lower than for the top AlO2 layer. Knowledge of the surface structure will aid the understanding of how and which type of interface will be formed when LaAlO3 is used as a substrate as a function of temperature and pressure, and so lead to improved design of device structures.

  11. Lead poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Beijers, J A

    1952-01-01

    Three cases of acute lead poisoning of cattle herds via ingestion are reported, and reference is made to several other incidents of lead in both humans and animals. The quantity of lead which was found in the livers of the dead cows varied from 6.5 to 19 mg/kg, while 1160 mg/kg of lead in the liver was found for a young cow which was poisoned experimentally with 5 gms of lead acetate per day; hence, there appears to be great variability in the amounts deposited that can lead to intoxication and death. No evidence was found for a lead seam around the teeth, prophyrinuria, or basophil granules in the erythrocytes during acute or chronic lead poisoning of cattle or horses examined. Reference is made to attempts of finding the boundary line between increased lead absorption and lead intoxication in humans, and an examination of 60 laborers in an offset-printing office containing a great deal of inhalable lead (0.16 to 1.9 mg/cu m air) is reviewed. Physical deviation, basophylic granulation of erythrocytes, increased lead content of the urine, and porphyrinuria only indicate an increased absorption of lead; the use of the term intoxication is justified if, in addition, there are complaints of lack of appetite, constipation, fatigue, abdominal pain, and emaciation.

  12. Lead telluride with increased mechanical stability for cylindrical thermoelectric generators

    International Nuclear Information System (INIS)

    Schmitz, Andreas

    2013-01-01

    remain at a very high level, reaching a maximum figure of merit ZT around 1.2. In addition to the thermoelectric properties the mechanical properties of lanthanum doped lead telluride were studied for the first time within this work. Lanthanum significantly increases the hardness of PbTe. SEM analysis of sintered samples reveals vast amounts of lanthanum rich precipitates within the matrix. This is partly attributed to the chosen route for material synthesis. Furthermore, the doped material's thermoelectric properties are highly unstable. The reason for this still has to be investigated. Based on the process and material developments described in this work a prototype of a tubular thermoelectric generator was constructed. In the course of this construction a process for sintering rings and tubes of lead telluride was developed and successfully implemented.

  13. A meta-analysis of water quality and aquatic macrophyte responses in 18 lakes treated with lanthanum modified bentonite (PHOSLOCK®)

    NARCIS (Netherlands)

    Spears, B.M.; Mackay, E.; Yasseri, S.; Gunn, I.D.M.; Waters, K.E.; Andrews, C.; Cole, S.; Ville, de M.; Kelly, M.; Meis, S.; Moore, A.L.; Nurnberg, G.K.; Oosterhout, van Frank; Lurling, M.F.L.L.W.

    2016-01-01

    Lanthanum (La) modified bentonite is being increasingly used as a geo-engineering tool for the control of phosphorus (P) release from lake bed sediments to overlying waters. However, little is known about its effectiveness in controlling P across a wide range of lake conditions or of its potential

  14. Characterization of phosphate sequestration by a lanthanum modified bentonite clay: A solid-state NMR, EXAFS and PXRD study

    DEFF Research Database (Denmark)

    Dithmer, Line; Lipton, Andrew S; Reitzel, Kasper

    2015-01-01

    Phosphate (Pi) sequestration by a lanthanum (La) exchanged clay mineral (La-Bentonite), which is extensively used in chemical lake restoration, was investigated on the molecular level using a combination of 31P and 139La solid state NMR spectroscopy (SSNMR), extended X-ray absorption spectroscopy...

  15. effect of post-precipitation treatment on the pore-structure stability of sol-gel derived lanthanum zirconate

    NARCIS (Netherlands)

    Nair, Jalajakumari; Kumar, K.N.P.; Nair, P.; van Ommen, J.G.; Ross, J.R.H.; Ross, Julian R.H.; Burggraaf, Anthonie J.; Burggraaf, Anthonie

    1998-01-01

    The importance of post-precipitation treatments (pore-fluid exchange and its removal) on the evolution of the texture of coprecipitated lanthanum zirconate has been investigated. The nature of the pore fluid and the type of fluid-removal (drying) process have shown a profound effect on the aggregate

  16. The Catalytic Activity of Modified Zeolite Lanthanum on the Catalytic Cracking of Al-Duara Atmospheric Distillation Residue

    Directory of Open Access Journals (Sweden)

    Karim Khalifa Esgair

    2016-03-01

    Full Text Available Atmospheric residue fluid catalytic cracking was selected as a probe reaction to test the catalytic performance of modified NaY zeolites and prepared NaY zeolites. Modified NaY zeolites have been synthesized by simple ion exchange methods. Three samples of modified zeolite Y have been obtained by replacing the sodium ions in the original sample with lanthanum and the weight percent added are 0.28, 0.53, and 1.02 respectively. The effects of addition of lanthanum to zeolite Y in different weight percent on the cracking catalysts were investigated using an experimental laboratory plant scale of fluidized bed reactor. The experiments have been performed with weight hourly space velocity (WHSV range of 6 to 24 h-1, and the range of temperature from 450 to 510 oC. The activity of the catalyst with 1.02 wt% lanthanum has been shown to be much greater than that of the sample parent NaY. Also it was observed that the addition of the lanthanum causes an increase in the thermal stability of the zeolite.

  17. Optimal Degrees of Transparency in Monetary Policymaking

    DEFF Research Database (Denmark)

    Jensen, Henrik

    2002-01-01

    According to most academics and policymakers, transparency in monetary policymaking is desirable. I examine this proposition in a small theoretical model emphasizing forward-looking private sector behavior. Transparency makes it easier for price setters to infer the central bank's future policy...... intentions, thereby making current inflation more responsive to policy actions. This induces the central bank to pay more attention to inflation rather than output gap stabilization. Then, transparency may be disadvantageous. It may actually be a policy-distorting straitjacket if the central bank enjoys low...

  18. Fiscal Transparency and Procyclical Fiscal Policy

    DEFF Research Database (Denmark)

    Andersen, Asger Lau; Nielsen, Lasse Holbøll Westh

    This paper examines why fiscal policy is procyclical in developing as well as developed countries. We introduce the concept of fiscal transparency into a model of retrospective voting, in which a political agency problem between voters and politicians generates a procyclical bias in government...... spending. The introduction of fiscal transparency generates two new predictions: 1) the procyclical bias in fiscal policy arises only in good times; and 2) a higher degree of fiscal transparency reduces the bias in good times. We find solid empirical support for both predictions using data on both OECD...

  19. Fully transparent thin-film transistor devices based on SnO2 nanowires.

    Science.gov (United States)

    Dattoli, Eric N; Wan, Qing; Guo, Wei; Chen, Yanbin; Pan, Xiaoqing; Lu, Wei

    2007-08-01

    We report on studies of field-effect transistor (FET) and transparent thin-film transistor (TFT) devices based on lightly Ta-doped SnO2 nano-wires. The nanowire-based devices exhibit uniform characteristics with average field-effect mobilities exceeding 100 cm2/V x s. Prototype nano-wire-based TFT (NW-TFT) devices on glass substrates showed excellent optical transparency and transistor performance in terms of transconductance, bias voltage range, and on/off ratio. High on-currents and field-effect mobilities were obtained from the NW-TFT devices even at low nanowire coverage. The SnO2 nanowire-based TFT approach offers a number of desirable properties such as low growth cost, high electron mobility, and optical transparency and low operation voltage, and may lead to large-scale applications of transparent electronics on diverse substrates.

  20. Reactivity and reactions to regulatory transparency in medicine, psychotherapy and counselling.

    Science.gov (United States)

    McGivern, Gerry; Fischer, Michael D

    2012-02-01

    We explore how doctors, psychotherapists and counsellors in the U.K. react to regulatory transparency, drawing on qualitative research involving 51 semi-structured interviews conducted during 2008-10. We use the concept of 'reactivity mechanisms' (Espeland & Sauder, 2007) to explain how regulatory transparency disrupts practices through simplifying and decontextualizing them, altering practitioners' reflexivity, leading to defensive forms of practice. We make an empirical contribution by exploring the impact of transparency on doctors compared with psychotherapists and counsellors, who represent an extreme case due to their uniquely complex practice, which is particularly affected by this form of regulation. We make a contribution to knowledge by developing a model of reactivity mechanisms, which explains how clinical professionals make sense of media and professional narratives about regulation in ways that produce emotional reactions and, in turn, defensive reactivity to transparency. Copyright © 2011 Elsevier Ltd. All rights reserved.