Sample records for ce probes substituting

  1. Study of the hyperfine magnetic field acting on Ce probes substituting for the rare earth and the magnetic ordering in intermetallic compounds RAg (R=rare earth) by first principles calculations; Estudo do campo hiperfino magnetico na sonda de Ce colocada nos compostos intermetalicos do tipo RAg (R=terra rara) e do ordenamento magnetico desses compostos usando calculos de primeiros principios

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Luciano Fabricio Dias


    In this work the magnetic hyperfine field acting on Ce atoms substituting the rare-earths in R Ag compounds (R = Gd e Nd) was studied by means of first-principles electronic structure calculations. The employed method was the Augmented Plane Waves plus local orbitals (APW+lo), embodied in the WIEN2k program, within the framework of the Density Functional Theory (DFT) and with the Generalized Gradient Approximation (GGA) for the exchange and correlation potential. The super-cell approach was utilized in order to simulate for the Ce atoms acting as impurities in the R Ag matrix. In order to improve for correlation effects within the 4f shells, a Hubbard term was added to the DFT Hamiltonian, within a procedure called GGA+U. It was found that the magnetic hyperfine field (MHF) generated by the Ce 4f electron is the main component of the total MHF and that the Ce 4f ground state level is probably a combination of the m{sub l} = -2 and m{sub l} = -1 sub-levels. In addition, the ground-state magnetic structure was determined for Ho Ag and Nd Ag by observing the behavior of the total energy as a function of the lattice volume for several possible magnetic ordering in these compounds, namely, ferromagnetic, and the (0,0,{pi}), ({pi},{pi},0) and (({pi},{pi},{pi}) types of anti-ferromagnetic ordering of rare-earth atoms. It was found that the ground-state magnetic structure is anti-ferromagnetic of type ({pi},{pi},0) for both, the Ho Ag and Nd Ag compounds. The energy difference of the ferromagnetic and antiferromagnetic ordering is very small in the case of the Nd Ag compound. (author)

  2. Effect of La substitution on thermopower in Kondo lattice CeNiAl{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Kowalczyk, A., E-mail:; Falkowski, M.; Toliński, T.


    The temperature dependence of the thermopower S(T) for Ce{sub 1−x}La{sub x}NiAl{sub 4} alloys have been studied. Thermopower of CeNiAl{sub 4} Kondo lattice system has larger value than for usual metals, reflecting enhanced electronic density of states near the Fermi level. In comparison to CeNiAl{sub 4}, the substitution of Ce by La drastically reduces the S(T) values. The S(T) dependence of Ce{sub 1−x}La{sub x}NiAl{sub 4} exhibits positive or negative peaks around 30–40 K. The peak position and its absolute value depend on the La content. The S(T) shows a strong temperature dependence at low temperatures, which is consistent with the temperature dependence of the electrical resistivity. Additionally, it is observed that the applied magnetic field slightly reduces the S(T) values. - Highlights: • Negative thermopower for CeNiAl{sub 4} after substituting Ce with La. • Heavy fermion behaviour at low temperatures. • Magnetic field reduces the thermopower values. • Predomination of the energy scale determined by the Kondo temperature.

  3. Synthesis and characterization of Ce-substituted hydroxyapatite by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Kaygili, Omer, E-mail: [Department of Physics, Faculty of Science, Firat University, 23119 Elazig (Turkey); Dorozhkin, Sergey V., E-mail: [Kudrinskaja sq. 1-155, Moscow 123242 (Russian Federation); Keser, Serhat, E-mail: [Department of Chemistry, Faculty of Science, Firat University, 23119 Elazig (Turkey)


    Both undoped hydroxyapatite (HAp) and three Ce-substituted HAp samples with variable amounts (from 0.5 to 2 at.%) of Ce were synthesized by sol–gel method. The samples were studied by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy to determine the crystallite size, crystallinity degree, phases, functional groups, morphology and elemental composition. In all samples, the amount of HAp exceeded 92%, while the amount of admixture β-TCP was always below 8% and no changes were observed by addition of Ce. The crystallinity degree of the samples was always within 84–89%, while the calculated dimensions of crystallites appeared to be within 26–35 nm. The microstructure and elemental composition of all the samples were found to be affected by the addition of Ce. - Highlights: • Ce-containing hydroxyapatite (HAp) was prepared. • The influence of different amounts of Ce was investigated. • Incorporation of Ce into the crystal structure of HAp was detected.

  4. Local moments in the heterogeneous electronic state of Cd-substituted CeCoIn5: NQR relaxation rates (United States)

    Sakai, H.; Ronning, F.; Hattori, T.; Tokunaga, Y.; Kambe, S.; Zhu, J.-X.; Wakeham, N.; Yasuoka, H.; Bauer, E. D.; Thompson, J. D.


    We have used nuclear quadrupole resonance (NQR) to probe microscopically the response of a prototypical quantum critical metal CeCoIn5 to substitutions of small amounts of Cd for In. Approximately half of the Cd substituents induce local Ce moments in their close proximity, as observed by site-dependent longitudinal nuclear spin relaxation rates 1/T1. To reaffirm that localized f moments are induced around the Cd substituents, we find a Gaussian spin-echo decay rate 1/T2G of transverse nuclear spin relaxation. Further, {T}1T/{T}2\\text{G}2 for the NQR subpeak is found to be proportional to temperatures, again indicating local moments fluctuations around the Cd substituents, while that for the NQR main peak shows a T0.7-dependence. The latter temperature dependence is close to 0.75 in pure CeCoIn5 and indicates that the bulk electronic state is located close to a two dimensional quantum critical instability.

  5. Effect of substitution of Ce on superconducting properties of Bi1 ...

    Indian Academy of Sciences (India)

    journal of. May & June 2002 physics pp. 871–875. Effect of substitution of Ce on superconducting properties of Bi1.7Pb0.3Sr2Ca2−xCexCu3O10+δ system. R R KOTHAWALE1,∗. , B N DOLE2 and S S SHAH3. 1Department ... pestle and precalcined at 800. ◦. C for 240 h. The calcined powders were ground and re-. Figure 1 ...

  6. Frustrated magnetic structure of Y-substituted CePdAl studied by powder neutron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Cermak, Petr; Javorsky, Pavel [Charles University, Faculty of Mathematics and Physics, Department of Condensed Matter Physics, Ke Karlovu 5, 121 16 Prague 2 (Czech Republic); Hofmann, Tommy, E-mail: [Helmholtz-Zentrum Berlin, Lise-Meitner Campus, Glienicker Str. 100, 14109 Berlin (Germany)


    CePdAl is a heavy-fermion antiferromagnet with T{sub N} = 2.7 K, crystallizing in the ZrNiAl-type structure. The magnetic structure is described by the propagation vector k = (1/2, 0, {tau}), {tau} = 0.35, with the cerium magnetic moments aligned along the c-axis. One third of magnetic moments remains disordered due to the geometrical frustration. Specific heat measurements on substituted Ce{sub 1-x}Y{sub x}PdAl compounds revealed strong reduction of T{sub N} with Y substitution and the antiferromagnetic order vanishes around x = 0.2. To investigate the microscopic details of the changes in the magnetic structure evoked by nonmagnetic ion substitution, we have performed an experiment on the powder neutron diffractometer E6 at HZB on the samples with x = 0.02, 0.06 and 0.1. Measurements showed the magnitude reduction of the ordered cerium moments with Y substitution while the propagation vector and other magnetic structure characteristics remain unchanged.

  7. Correlated electron state in CeCu2Si2 controlled through Si to P substitution (United States)

    Lai, Y.; Saunders, S. M.; Graf, D.; Gallagher, A.; Chen, K.-W.; Kametani, F.; Besara, T.; Siegrist, T.; Shekhter, A.; Baumbach, R. E.


    CeCu2Si2 is an exemplary correlated electron metal that features two domes of unconventional superconductivity in its temperature-pressure phase diagram. The first dome surrounds an antiferromagnetic quantum critical point, whereas the more exotic second dome may span the termination point of a line of f -electron valence transitions. This behavior has received intense interest, but what has been missing are ways to access the high pressure behavior under milder conditions. Here we study Si → P chemical substitution, which compresses the unit cell volume but simultaneously weakens the hybridization between the f - and conduction electron states and encourages complex magnetism. At concentrations that show magnetism, applied pressure suppresses the magnetic ordering temperature and superconductivity is recovered for samples with low disorder. These results reveal that the electronic behavior in this system is controlled by a nontrivial combination of effects from unit cell volume and electronic shell filling. Guided by this topography, we discuss prospects for uncovering a valence fluctuation quantum phase transition in the broader family of Ce-based ThCr2Si2 -type materials through chemical substitution.

  8. La Substitution and Pressure Studies on CeCoSi: A Possible Antiferroquadrupolar Ordering Induced by Pressure (United States)

    Tanida, Hiroshi; Muro, Yuji; Matsumura, Takeshi


    The La-substitution and pressure effects on antiferromagnet CeCoSi with a tetragonal crystal structure were investigated in order to clarify the origin of the pressure induced ordered phase (PIOP) with an enormously high transition temperature of T0 ˜ 38 K. By substituting Ce with La, the PIOP shifts to high pressures, and the maximum value of T0 is suppressed, indicating that the PIOP originates from a Ce-Ce interaction. At T0, the magnetic susceptibility exhibits not a cusp, but an increase with decreasing temperature, as is frequently observed in antiferroquadrupolar (AFQ) ordering. Based on these results, we propose that a possible origin of the PIOP is an AFQ ordered phase of Ce-4f electron. Due to the lack of local inversion symmetry at the Ce sites, the AFQ order could be accompanied by odd parity multipolar moments. Since there is no clear evidence of successive transitions below T0, the remaining Kramers degeneracy could be lifted by the Kondo coupling.

  9. Full Solar Spectrum Light Driven Thermocatalysis with Extremely High Efficiency on Nanostructured Ce Ion Substituted OMS-2 Catalyst for VOCs Purification

    DEFF Research Database (Denmark)

    Hou, J.T.; Li, Y.Z.; Mao, M.Y.


    solar spectrum, visible-infrared, and infrared light, the Ce ion substituted OMS-2 catalyst exhibits extremely high catalytic activity and excellent durability for the oxidation of volatile organic pollutants such as benzene, toluene, and acetone. Based on the experimental evidence, we propose a novel...... in a considerable increase of temperature. By combining the efficient photothermal conversion and thermocatalytic activity of the Ce ion substituted OMS-2 catalyst, we carried out full solar spectrum, visible-infrared, and infrared light driven catalysis with extremely high efficiency. Under the irradiation of full...... mechanism of solar light driven thermocatalysis for the Ce ion substituted OMS-2 catalyst. The reason why the Ce ion substituted OMS-2 catalyst exhibits much higher catalytic activity than pure OMS-2 and CeO2/OMS-2 nano composite under the full solar spectrum irradiation is discussed....

  10. Effect of Ce-substitution on structural, morphological, magnetic and DC electrical resistivity of Co-ferrite materials (United States)

    Mammo, Tulu Wegayehu; Murali, N.; Sileshi, Yonatan Mulushoa; Arunamani, T.


    Partially substituted spinel structured CoFe2-xCexO4 (x = 0, 0.03, 0.06, and 0.09) samples have been synthesized using the sol-gel autocombustion route. Stoichiometric amounts of metal nitrates and citric acid were mixed in double distilled water to get homogeneously mixed solutions which were then heated to burn and result in samples for the next two-step annealing procedures. Structural and phase characterization using powder X-ray diffraction (XRD) has been carried out; and a pure spinel structured samples with lattice parameters increasing with the increase of Ce concentration levels have been obtained. The lattice parameters were calculated to be in the range of 8.42774-8.4744 Å. Field emission scanning electron microscopy (FESEM) microstructure characterizations revealed clear grain structures of the so synthesized samples with grain sizes decreasing with Ce. Fourier transform Infrared (FT-IR) characterization measured in the wave number ranges of 400-4000 cm-1 showed the cation vibrations and stretching at characteristic frequency of 668-418 cm-1. The DC resistivity measurements confirmed a decrease in the resistivity of the samples with the increase of Ce concentration and with the increase of temperature in all of the samples synthesized. Room temperature vibrating sample magnetometer measurement revealed the magnetic properties of the samples with decreasing magnetic parameters as Ce concentration increases.

  11. Silicon-substituted Xanthene Dyes and Their Unique Photophysical Properties for Fluorescent Probes. (United States)

    Ikeno, Takayuki; Nagano, Tetsuo; Hanaoka, Kenjiro


    Silicon-substituted xanthene dyes, with Si in place of the O atom at the xanthene 10-position, are practically useful as far-red to near-infrared fluorophores. Many fluorescent probes based on them have recently been reported. These fluorophores retain the advantages of typical xanthene dyes and also show unique properties suitable for applications such as multi-color and super-resolution imaging. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Determining the effect of Ru substitution on the thermal stability of CeFe[subscript 4-x]Ru[subscript x]Sb[subscript 12

    Energy Technology Data Exchange (ETDEWEB)

    Sigrist, Jessica A.; Walker, James D.S.; Hayes, John R.; Gaultois, Michael W.; Grosvenor, Andrew P. (Saskatchewan)


    The ternary, rare-earth filled (RE) Skutterudites (REM{sub 4}Pn{sub 12}; M = Fe-Os; Pn = P-Sb) have been proposed for use in high-temperature thermoelectric devices to convert waste heat to useful power. CeFe{sub 4}Sb{sub 12} has been one of the most popular materials proposed for this application; however, it oxidizes at relatively low temperatures. The thermal stability of Skutterudites can be enhanced by selective substitution of the constituent elements and Eu(Fe,Ru){sub 4}Sb{sub 12} variants have been found to oxidize at temperatures above that of CeFe{sub 4}Sb{sub 12}. Unfortunately, these materials have poor thermoelectric properties. In this study, the thermal stability of CeFe{sub 4-x}Ru{sub x}Sb{sub 12} was examined depending on the value of x. (These compounds have similar thermoelectric properties to those of CeFe{sub 4}Sb{sub 12}.) It has been found by use of TGA and XANES that the temperature at which point CeFe{sub 4-x}Ru{sub x}Sb{sub 12} oxidizes increases with greater Ru substitution. XANES was also used to confirm the general charge assignment of Ce{sup 3+}Fe{sub 4-x}{sup 2+}Ru{sub x}{sup 2+}Sb{sub 12}{sup 1-}.

  13. Determining the effect of Ru substitution on the thermal stability of CeFe 4- xRu xSb 12 (United States)

    Sigrist, Jessica A.; Walker, James D. S.; Hayes, John R.; Gaultois, Michael W.; Grosvenor, Andrew P.


    The ternary, rare-earth filled (RE) Skutterudites (REM 4Pn12; M = Fe-Os; Pn = P-Sb) have been proposed for use in high-temperature thermoelectric devices to convert waste heat to useful power. CeFe 4Sb 12 has been one of the most popular materials proposed for this application; however, it oxidizes at relatively low temperatures. The thermal stability of Skutterudites can be enhanced by selective substitution of the constituent elements and Eu(Fe,Ru) 4Sb 12 variants have been found to oxidize at temperatures above that of CeFe 4Sb 12. Unfortunately, these materials have poor thermoelectric properties. In this study, the thermal stability of CeFe 4- xRu xSb 12 was examined depending on the value of x. (These compounds have similar thermoelectric properties to those of CeFe 4Sb 12.) It has been found by use of TGA and XANES that the temperature at which point CeFe 4- xRu xSb 12 oxidizes increases with greater Ru substitution. XANES was also used to confirm the general charge assignment of Ce 3+Fe 4- x2+Ru x2+Sb 121-.

  14. Ratiometric Fluorescent Silicon Quantum Dots-Ce6 Complex Probe for the Live Cell Imaging of Highly Reactive Oxygen Species. (United States)

    Zhao, Qianqian; Zhang, Ren; Ye, Daixin; Zhang, Song; Chen, Hui; Kong, Jilie


    The monitoring of reactive oxygen species (ROS) in living cells remains challenging because of the complexity, short half-life, and autofluorescence of biological samples. In this work, we designed a ratiometric fluorescent probe for the detection and imaging of ROS, which was constructed from silicon quantum dots (Si QDs) with chlorin e6 (Ce6) through electrostatic attraction and showed well-resolved dual fluorescence emission signals (490 and 660 nm). Sensitive and selective biosensing of hydroxyl radical (•OH) was demonstrated on the basis of fluorescence quenching of the Si QDs and Ce6 as an internal reference to avoid environmental interference, with a detection limit of ∼0.97 μM. The endogenous release of •OH was also monitored and imaged in living cells.

  15. Effects of (LiCe) co-substitution on the structural and electrical properties of CaBi2Nb2O9 ceramics (United States)

    Tian, Xiao-Xia; Qu, Shao-Bo; Du, Hong-Liang; Li, Ye; Xu, Zhuo


    The piezoelectric, dielectric, and ferroelectric properties of the (LiCe) co-substituted calcium bismuth niobate (CaBi2Nb2O9, CBNO) are investigated. The piezoelectric properties of CBNO ceramics are significantly enhanced and the dielectric loss tan δ decreased. This makes poling using (LiCe) co-substitution easier. The ceramics (where □ represents A-site Ca2+ vacancies, possess a pure layered structure phase and no other phases can be found. The Ca0.88(LiCe)0.04□0.04Bi2Nb2O9 ceramics possess optimal piezoelectric properties, with piezoelectric coefficient (d33) and Curie temperature (TC) found to be 13.3 pC/N and 960 °C, respectively. The dielectric and piezoelectric properties of the (LiCe) co-substituted CBNO ceramics exhibit very stable temperature behaviours. This demonstrates that the CBNO ceramics are a promising candidate for ultrahigh temperature applications.

  16. Growth and Characterization of Ce- Substituted Nd2Fe1411B Single Crystals

    Energy Technology Data Exchange (ETDEWEB)

    Susner, M. A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Conner, B. S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Saparov, B. I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; McGuire, M. A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Crumlin, E. J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source; Veith, G. M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source; Cao, H. B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Quantum Condensed Matter Division; Shanavas, K. V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Parker, D. S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Chakoumakos, B. C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Quantum Condensed Matter Division; Sales, B. C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division


    Single crystals of (Nd1-xCex)2Fe14B are grown out of Fe-(Nd,Ce) flux. Chemical and structural analysis of the crystals indicates that (Nd1-xCex)2Fe14B forms a solid solution until at least x = 0.38 with a Vegard-like variation of the lattice constants with x. Refinements of single crystal neutron diffraction data indicate that Ce has a slight site preference (7:3) for the 4g rare earth site over the 4f site. Furthermore, magnetization measurements show that for x = 0.38 the saturation magnetization at 400 K, a temperature important to applications, falls from 29.8 for the parent Nd2Fe14B to 27.6 μB/f.u., the anisotropy field decreases from 5.5 T to 4.7 T, and the Curie temperature decreases from 586 to 543 K. First principles calculations carried out within density functional theory are used to explain the decrease in magnetic properties due to Ce substitution. Although the presence of the lower-cost and more abundant Ce slightly affects these important magnetic characteristics, this decrease is not large enough to affect a multitude of applications. Ce-substituted Nd2Fe14B is therefore a potential high-performance permanent magnet material with substantially reduced Nd content.

  17. Electron spin dynamics of Ce3 + ions in YAG crystals studied by pulse-EPR and pump-probe Faraday rotation (United States)

    Azamat, D. V.; Belykh, V. V.; Yakovlev, D. R.; Fobbe, F.; Feng, D. H.; Evers, E.; Jastrabik, L.; Dejneka, A.; Bayer, M.


    The spin relaxation dynamics of Ce3 + ions in heavily cerium-doped YAG crystals is studied using pulse-electron paramagnetic resonance and time-resolved pump-probe Faraday rotation. Both techniques address the 4 f ground state, while pump-probe Faraday rotation also provides access to the excited 5 d state. We measure a millisecond spin-lattice relaxation time T1, a microsecond spin coherence time T2, and a ˜10 ns inhomogeneous spin dephasing time T2* for the Ce3 + ground state at low temperatures. The spin-lattice relaxation of Ce3 + ions is due to modified Raman processes involving the optical phonon mode at ˜125 cm-1 . The relaxation at higher temperature goes through a first excited level of the 5/2 2F term at about ℏ ω ≈228 cm-1 . Effects provided by the hyperfine interaction of the Ce3 + with the 27Al nuclei are observed.

  18. Investigation of structural and magnetic properties of Ce{sup 3+}-substituted nanosized Co–Cr ferrites for a variety of applications

    Energy Technology Data Exchange (ETDEWEB)

    Mustafa, Ghulam, E-mail: [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Islam, M.U. [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Zhang, Wenli [State Key Laboratory of Electronic Thin Films and Integrated Devices, Chengdu 610054 (China); Jamil, Yasir [Department of Physics, University of Agriculture, Faisalabad 38040 (Pakistan); Anwar, Abdul Waheed [Department of Physics, University of Engineering and Technology, Lahore 54890 (Pakistan); Hussain, Mudassar [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Ahmad, Mukhtar, E-mail: [Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan)


    Highlights: • Ce-substituted spinel ferrites synthesized by coprecipitation route have been investigated. • The average particle size was in the range of 30.8–63.7 nm estimated by Scherer formula. • Saturation magnetization values were decreased with increasing Ce contents. • Coercivity for all samples is suitable for recording media, switching and EM materials. - Abstract: Nanocrystalline samples of Ce{sup 3+} substituted Co–Cr ferrite with chemical formula CoCr{sub 0.04}Ce{sub x}Fe{sub 1.96−x}O{sub 4} (0 ⩽ x ⩽ 0.1) have been synthesized by co-precipitation method and sintered at a temperature of 850 °C for 8 h. The samples were characterized using thermo-gravimetric and differential thermal analysis, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, atomic force microscopy and vibrating sample magnetometry. The XRD patterns and FTIR spectra confirm that the prepared samples reveal the formation of spinel ferrites. The average particle size was found to be in the range of 30.8–63.7 nm estimated by Scherer formula. The lattice constant varies in the range of 8.352–8.382 Å due to difference in the ionic radii of the substituted cations. IR studies confirm two main absorption bands in the frequency range of 400–800 cm{sup −1} arising due to the tetrahedral (A-site) and octahedral (B-site) stretching vibrations. The elemental analysis as obtained from the EDXS measurement is in close agreement with the expected composition from the stoichiometry of the reactant solutions. The M–H loops show that the saturation magnetization decreased gradually with increasing Ce content, while the coercivity is related to the microstructure of Ce-substituted samples. The obtained results suggest that the investigated materials are potential candidates for magnetic recording media, security, switching and high frequency applications.

  19. Determination of total antioxidant capacity by a new spectrofluorometric method based on Ce(IV) reduction: Ce(III) fluorescence probe for CERAC assay. (United States)

    Ozyurt, Dilek; Demirata, Birsen; Apak, Resat


    A Ce(IV)-based reducing capacity (CERAC) assay was developed to measure the total antioxidant capacity (TAC) of foods, in which Ce(IV) would selectively oxidize antioxidant compounds but not citric acid and reducing sugars which are not classified as antioxidants. The method is based on the electron-transfer (ET) reaction between Ce(IV) ion and antioxidants in optimized acidic sulphate medium (i.e., 0.3 M H(2)SO(4) and 0.7 M Na(2)SO(4)) and subsequent determination of the produced Ce(III) ions by a fluorometric method. The fluorescent product, Ce(III), exhibited strong fluorescence at 360 nm with an excitation wavelength of 256 nm, the fluorescence intensity being correlated to antioxidant power of the original sample. The linear concentration range for most antioxidants was quite wide, e.g., 5.0 × 10(-7)-1.0 × 10(-5) M for quercetin. The developed procedure was successfully applied to the TAC assay of antioxidant compounds such as trolox, quercetin, gallic acid, ascorbic acid, catechin, naringin, naringenin, caffeic acid, ferulic acid, glutathione, and cysteine. The proposed method was reproducible, additive in terms of TAC values of constituents of complex mixtures, and the trolox equivalent antioxidant capacities (TEAC coefficients) of the tested antioxidant compounds gave good correlations with those found by reference methods such as ABTS and CUPRAC.

  20. Folic acid-targeted magnetic Tb-doped CeF3 fluorescent nanoparticles as bimodal probes for cellular fluorescence and magnetic resonance imaging. (United States)

    Ma, Zhi-Ya; Liu, Yu-Ping; Bai, Ling-Yu; An, Jie; Zhang, Lin; Xuan, Yang; Zhang, Xiao-Shuai; Zhao, Yuan-Di


    Magnetic fluorescent nanoparticles (NPs) have great potential applications for diagnostics, imaging and therapy. We developed a facile polyol method to synthesize multifunctional Fe3O4@CeF3:Tb@CeF3 NPs with small size (imaging agents for simultaneous in vitro targeted fluorescence imaging and magnetic resonance imaging (MRI) of HeLa cells with overexpressed folate receptors (FR). The results indicated that these NPs had strong luminescence and enhanced T2-weighted MR contrast and would be promising candidates as multimodal probes for both fluorescence and MRI imaging.

  1. Probing metastable Sm2+ and optically stimulated tunnelling emission in YPO4: Ce, Sm

    DEFF Research Database (Denmark)

    Prasad, Amit Kumar; Kook, Myung Ho; Jain, Mayank


    When the model dosimetry system YPO4: Ce3+, Sm3+ is exposed to X-rays, the charge state of the dopants changes, becoming Ce4+ and Sm2+ via hole and electron trapping, respectively which are metastable; the original charge states can be achieved through electron transfer back from Sm2+ to Ce4+ via...

  2. Effect of Al/Ga substitution on the structural and luminescence properties of Y3(Al1-xGax)5O12: Ce3+ phosphors (United States)

    Fu, Sheng; Tan, Jin; Bai, Xin; Yang, Shanjie; You, Lei; Du, Zhengkang


    As candidates for display and lighting materials, a series of gallium-substituted cerium-doped yttrium aluminum garnet (Y3(GaxAl1-x)5O12: Ce3+) phosphors were synthesized by high temperature solid-state reaction. The phases, morphology, luminescence spectra and thermal stability of the phosphors were investigated. The volatilization of Ga2O3 induces the constituents out of stoichiometric ratio and different impurities in the system. The excitation and emission spectra occur red shift (339 nm - 351 nm) and blue shift (465 nm - 437 nm), and blue shift (541 nm - 517 nm), respectively. The spectra have no further blue shift and the luminescence intensity decrease with x over 0.4. Combining crystal structure with PL spectrum, the distortion of dodecahedron and crystal field splitting of 5d level of Ce3+ are influenced by Ga3+ in octahedral coordination polyhedron rather than tetrahedron. The crystalline perfection and Ga3+ occupying the tetrahedron induce less garnet phase formation, more impurities and the 5d level located in the conductive bands, thus accounting for the x = 0.4 turning points of the PL and PLE intensity. Based on the thermal quenching and CIE, the Y3(GaxAl1-x)5O12: Ce3+0.06 phosphors have great potential for use on the w-LED.

  3. Charge-coupled substituted garnets (Y3-xCa0.5xM0.5x)Fe5O12 (M = Ce, Th): structure and stability as crystalline nuclear waste forms. (United States)

    Guo, Xiaofeng; Kukkadapu, Ravi K; Lanzirotti, Antonio; Newville, Matthew; Engelhard, Mark H; Sutton, Stephen R; Navrotsky, Alexandra


    The garnet structure has been proposed as a potential crystalline nuclear waste form for accommodation of actinide elements, especially uranium (U). In this study, yttrium iron garnet (YIG) as a model garnet host was studied for the incorporation of U analogs, cerium (Ce) and thorium (Th), incorporated by a charge-coupled substitution with calcium (Ca) for yttrium (Y) in YIG, namely, 2Y(3+) = Ca(2+) + M(4+), where M(4+) = Ce(4+) or Th(4+). Single-phase garnets Y3-xCa0.5xM0.5xFe5O12 (x = 0.1-0.7) were synthesized by the citrate-nitrate combustion method. Ce was confirmed to be tetravalent by X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. X-ray diffraction and (57)Fe-Mössbauer spectroscopy indicated that M(4+) and Ca(2+) cations are restricted to the c site, and the local environments of both the tetrahedral and the octahedral Fe(3+) are systematically affected by the extent of substitution. The charge-coupled substitution has advantages in incorporating Ce/Th and in stabilizing the substituted phases compared to a single substitution strategy. Enthalpies of formation of garnets were obtained by high temperature oxide melt solution calorimetry, and the enthalpies of substitution of Ce and Th were determined. The thermodynamic analysis demonstrates that the substituted garnets are entropically rather than energetically stabilized. This suggests that such garnets may form and persist in repositories at high temperature but might decompose near room temperature.

  4. Ce (III) - Porphyrin Sandwich Complex Ce2(TPP)3: A Rod-Like Nanoparticle as a Fluorescence Turn-Off Probe for Detection of Hg (II) and Cu (II). (United States)

    Boroujerdi, Ramin


    In this study the researcher reports a novel, one step synthesized rod-like nanoparticles of cerium (III)-tetraphenylporphyrin sandwich complex as a spectrofluorometric sensor to measure trace amount of Hg (II) and Cu (II) metal ions. Moreover, the synthesized fluorescent probe was able to detect higher amounts (>10(-4) M) of Hg (II) in aqueous media by changing the color which can also be used as a selective mercury naked-eye sensor. The selectivity and sensitivity of the sensor based on its fluorescence quenching in the presence of Hg (II) and Cu (II) were studied according to the Stern-Volmer equation. The detection limit of the sensor was 16 nM for Hg (II) and about 2.34 μM for Cu (II) ions. Graphical Abstract Ce2(TPP)3 sandwich complex application as a fluorescent probe for measuring trace amounts of mercury and copper in real samples.

  5. Influence of the Electronic Structure and Optical Properties of CeO2 and UO2 for Characterization with UV-Laser Assisted Atom Probe Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Billy Valderrama; H.B. Henderson; C. Yablinsky; J. Gan; T.R. Allen; M.V. Manuel


    Oxide materials are used in numerous applications such as thermal barrier coatings, nuclear fuels, and electrical conductors and sensors, all applications where nanometer-scale stoichiometric changes can affect functional properties. Atom probe tomography can be used to characterize the precise chemical distribution of individual species and spatially quantify the oxygen to metal ratio at the nanometer scale. However, atom probe analysis of oxides can be accompanied by measurement artifacts caused by laser-material interactions. In this investigation, two technologically relevant oxide materials with the same crystal structure and an anion to cation ratio of 2.00, pure cerium oxide (CeO2) and uranium oxide (UO2) are studied. It was determined that electronic structure, optical properties, heat transfer properties, and oxide stability strongly affect their evaporation behavior, thus altering their measured stoichiometry, with thermal conductance and thermodynamic stability being strong factors.

  6. Bulk Superconductivity Induced by Se Substitution in BiCh2-Based Layered Compounds Eu0.5Ce0.5FBiS2-xSex (United States)

    Goto, Yosuke; Sogabe, Ryota; Mizuguchi, Yoshikazu


    We report the effect of Se substitution on the crystal structure and superconductivity of BiCh2-based (Ch: S, Se) layered compounds Eu0.5Ce0.5FBiS2-xSex (x = 0-1). Crystal structure analysis showed that both lattice constants, a and c, increased with increasing x, which is different from the related La-doped system Eu0.5La0.5FBiS2-xSex. This is due to Se substitution at both in-plane and out-of-plane Ch sites in the present Ce-doped system. Zero resistivity was observed for x = 0.2-1 above 2 K. The superconducting properties of Eu0.5Ce0.5FBiS2-xSex were investigated by magnetic susceptibility measurement, and the highest superconducting transition temperature of 3.5 K was obtained for x = 0.6 with a large shielding volume fraction. The emergence of bulk superconductivity and metallic conductivity can be qualitatively described in terms of the increased in-plane chemical pressure effect. A magnetic anomaly below 8 K, probably because of the ferromagnetic order of the magnetic moment of Ce3+ ions, coexists with bulk superconductivity in the BiCh2 layer. Since the effect of Se substitution on the magnetic transition temperature is ignorable, we suggest that the coupling between the magnetic order at the (Eu,Ce)F layer and the superconductivity at the Bi(S,Se)2 layer is weak.

  7. Oligoethylene glycol-substituted aza-BODIPY dyes as red emitting ER-probes. (United States)

    Kamkaew, Anyanee; Thavornpradit, Sopida; Puangsamlee, Thamon; Xin, Dongyue; Wanichacheva, Nantanit; Burgess, Kevin


    This study features aza-BODIPY (BF2-chelated azadipyrromethene) dyes with two aromatic substituents linked by oligoethylene glycol fragments to increase hydrophilicity of aza-BODIPY for applications in intracellular imaging. To prepare these, two chalcones were attached α,ω onto oligoethylene glycol fragments, then reacted with nitromethane anion. Conjugate addition products from this reaction were then subjected to typical conditions for synthesis of aza-BODIPY dyes (NH4OAc, (n)BuOH, 120 °C); formation of boracycles in this reaction was concomitant with creation of macrocycles containing the oligoethylene glycol fragments. Similar dyes with acyclic oligoelythene glycol substituents in the same position were used to compare the efficiencies of the intra- and inter-molecular aza-BODIPY forming reactions, and the characteristics of the products. All the fluors with oligoethylene glycol fragments, i.e. cyclic or acyclic, localized in the endoplasmic reticulum of a fibroblast cell line (WEHI-13VAR), the human pancreatic cancer cell line (PANC-1, rough ER predominates) and human liver cancer cell line (HepG2, smooth ER prevalent). These fluors are potentially useful for near IR (λmax emis at 730 nm) ER staining probes.

  8. Effects of A-Site (NaCe) Substitution with Na-Deficiency on Structures and Properties of CaBi4Ti4O15-Based High-Curie-Temperature Ceramics (United States)

    Yan, Haixue; Li, Chengen; Zhou, Jiaguang; Zhu, Weimin; He, Lianxin; Song, Yuxin; Yu, Youhua


    Three kinds of bismuth-layer-structured ferroelectric (BLSF) ceramics, CaBi4Ti4O15 (CBT), Ca0.8(CeNa)0.1Bi4Ti4O15 (CNBT), and Na-deficient Ca0.8(Ce0.1Na0.05\\Box0.05)Bi4Ti4O15 [CN\\BoxBT] (where \\Box represents vacancies) were prepared by a conventional ceramic technique. X-ray powder diffraction showed that their crystal structures are a single phase of BLSF with m=4. Sintering characteristics of the three ceramics were also discussed. Scanning electron microscope (SEM) micrographs of CN\\BoxBT showed that the grain is platelike. The A-site (NaCe) substitution can improve the piezoelectric constant d33 and high-temperature resistivity with decreasing Curie temperature. The modification by A-site (NaCe) substitution with Na-deficiency is more pronounced than CNBT, which not only leads to a very high piezoelectric constant d33 and high-temperature resistivity but also increases the Curie temperature. The reason for the high Tc (Tc=866°C) of CN\\BoxBT is considered to be internal stress. As a result, Na-deficient CN\\BoxBT ceramic is found to be an excellent high-temperature piezoelectric material.

  9. Substitution of Au or Hg into BaTl2 and BaIn2. New ternary examples of smaller CeCu2-type intermetallic phases. (United States)

    Dai, Jing-Cao; Corbett, John D


    The compounds BaAu(0.40(2))Tl(1.60(7)) (1), BaAu(0.36(4))In(1.64(4)) (2), and BaHg(0.92(2))In(1.08(2)) (3) have been prepared by high-temperature techniques. Single-crystal X-ray diffraction shows that these have the orthorhombic CeCu(2)-type structure, Imma, Z = 4 (a = 5.140(1), 5.104(1), 5.145(1) A; b = 8.317(2), 8.461(2), 8.373(2) A; c = 8.809(2), 8.580(2), 8.715(2) A, respectively). The structure consists of a four-linked honeycomblike polyanion (4(2)6(3)8) of infinity3[Tr2]2- (Tr = In or Tl) with encapsulated Ba2+ cations. The Au or Hg randomly replace Tr in a single type of site. The two gold phases exhibit appreciable nonstoichiometry ranges. Band calculations (EHTB) demonstrate that the three compounds are electron-poor and metallic, and the latter has been confirmed for 1 through resistivity and magnetic susceptibility measurements. The orthorhombic structure of 1 contrasts with the hexagonal structure of BaTl2 (CaIn2-type, P6(3)/mmc), a change that appears to be driven by substitution of the smaller Au atoms into the polyanion network. Relativistic effects for the heavier Au and Hg are evidently responsible for decreases in lattice parameters and bond lengths from BaIn2 to those in isostructural 2 and 3.

  10. Structure and luminescence properties of Ce3+ doped KBa1-x(Mg/Zn)xY(BO3)2 and K1-yNayBaY(BO3)2 phosphors evolved from cation substitution (United States)

    Xu, Rui; Liang, Yujun; Liu, Shiqi; Zhu, Yingli; Wu, Xingya; Li, Kai; Zhou, Wei


    The tunable blue-emitting KBa1-x(Mg/Zn)xY0.95(BO3)2:0.05Ce3+ and K1-yNayBaY0.95(BO3)2:0.05Ce3+ phosphors have been investigated via cation substitution of Mg2+/Zn2+ for Ba2+ and Na+ for K+ in KBaY(BO3)2 host. The crystal structures, photoluminescence properties, thermal stability and the effect of Mg2+/Zn2+/Na+ concentration on the luminescence characteristics were investigated in detail. The XRD analysis implied that KBa1-x(Mg/Zn)xY(BO3)2 solid solutions were limited, while continuous solid solution was possible in K1-yNayBaY(BO3)2 system. Upon the excitation at 365 nm, the emission peaks of KBa1-x(Mg/Zn)xY0.95(BO3)2:0.05Ce3+ (0 ⩽ x ⩽ 0.6) blue-shifted from 435 to 424 nm, and K1-yNayBaY0.95(BO3)2:0.05Ce3+ (0 ⩽ y ⩽ 1) blue-shifted from 435 to 427 nm with the Mg2+/Zn2+/Na+ doping concentration increase. The thermal stabilities of KBa1-x(Mg/Zn)xY0.95(BO3)2:0.05Ce3+ phosphors were enhanced from 20 °C to 200 °C by increasing the concentration of Mg2+ and Zn2+. The substitution of Na+ for K+ led to a decrease in the proportion of 5D-2F5/2 and 5D-2F7/2 corresponding to the Gaussian fitting of Ce3+ in K1-yNayBaY0.95(BO3)2:0.05Ce3+ phosphors. At the temperature increased, the full width at half maximum of photoluminescence band of K0.8Na0.2BaY0.95(BO3)2:0.05Ce3+ decreased. However, the decreasing trend of FWHM became less obvious with the increasing concentration of Na+ in the temperature dependent photoluminescence spectra of K1-yNayBaY0.95(BO3)2:0.05Ce3+ phosphors.

  11. Structure and electric properties of cerium substituted SrBi1.8Ce0.2Nb2O9 and SrBi1.8Ce0.2Ta2O9 ceramics

    Directory of Open Access Journals (Sweden)

    Mohamed Afqir


    Full Text Available SrBi1.8Ce0.2Nb2O9 (SBCN and SrBi1.8Ce0.2Ta2O9 (SBCT powders were prepared via solid-state reaction method. X-ray diffraction analysis reveals that the SBCN and SBCT powders have the single phase orthorhombic Aurivillius structure at room temperature. The contribution of Raman scattering and FTIR spectroscopy of these samples were relatively smooth and resemble each other. The calcined powders were uniaxially pressed and sintered at 1250 °C for 8 h to obtaine dense ceramics. Dielectric constant, loss tangent and AC conductivity of the sintered Ce-doped SrBi2Nb2O9 and SrBi2Ta2O9 ceramics were measured by LCR meter. The Ce-doped SBN (SBCN ceramics have a higher Curie temperature (TC and dielectric constant at TC (380 °C and ε′ ∼3510 compared to the Ce-doped SBT (SBCT ceramics (330 °C and ε′ ∼115 when measured at 100 Hz. However, the Ce-doped SBT (SBCT ceramics have lower conductivity and dielectric loss.

  12. Probing the superconducting state via Andreev bound states in (La,Ce){sub 2}CuO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Wagenknecht, Michael; Scharinger, Sebastian; Koelle, Dieter; Kleiner, Reinhold [Physikalisches Institut - Experimentalphysik II and Center for Collective Quantum Phenomena, Universitaet Tuebingen (Germany); Graser, Siegfried; Schopohl, Nils [Institut fuer Theoretische Physik, Universitaet Tuebingen (Germany); Chesca, Boris [Department of Physics, Loughborough University (United Kingdom); Tsukada, Aiko [NTT Basic Research Laboratories, Atsugi-shi (Japan); Goennenwein, Sebastian T.B.; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany)


    We present quasiparticle tunneling data of (La,Ce){sub 2}CuO{sub 4} thin film bicrystal junctions. The differential conductance in the superconducting state shows a pronounced zero bias conductance peak (ZBCP). This peak is attributed to zero energy surface Andreev bound states due to the d-wave symmetry of the order parameter in this electron doped cuprate. Such bound states are closely related to the macroscopic phase coherence of the superconducting state. Hence the ZBCP due to these bound states must disappear at or below the upper critical field B{sub c2}(T). By following the disappearance of the ZBCP in the B-T-phase diagram we find a lower bound for B{sub c2}(0){approx}25 T which is higher than values reported previously for any electron doped cuprate. Following this observation we suggest a modified B-T-phase diagram with a larger region of superconductivity, leaving less room for a possible pseudogap phase.

  13. Facile sonochemical synthesis and morphology control of CePO{sub 4} nanostructures via an oriented attachment mechanism: Application as luminescent probe for selective sensing of Pb{sup 2+} ion in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Shiralizadeh Dezfuli, Amin [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Ganjali, Mohammad Reza, E-mail: [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Biosensor Research Center, Endocrinology and Metabolism Molecular–Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Norouzi, Parviz [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Biosensor Research Center, Endocrinology and Metabolism Molecular–Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)


    CePO{sub 4} nanostructures with hexagonal phase were controllably synthesized using Ce(NO{sub 3}){sub 3} reaction with NH{sub 4}H{sub 2}PO{sub 4} through a sonochemical method by simply varying the reaction conditions. By adding ethanol and polyethylene glycol (PEG), coral-reef nanostructures (CRNs) were synthesized and controlling over pH caused to nanorods/nanowires. Oriented attachment (OA) is proposed as dominant mechanism on the growth of nanostructures which is in competition with Ostwald ripening (OR). The crystal structure and morphology of the nanostructures were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. The luminescent properties of CePO{sub 4} with different morphologies have been studied. Among the nanostructures, nanoparticles with the highest intensity of fluorescent have been used as luminescent probe for selective sensing of Pb{sup 2+} ion in aqueous solution. - Highlights: • Facile sonochemical method has been used for synthesis of CePO{sub 4} nanostructures. • Coral-reef as a new morphology of nanostructures is introduced. • CePO{sub 4} NPs have been used as luminescent probe for selective sensing of Pb{sup 2+} ion.

  14. High-Pressure Synthesis, Structure, and Magnetic Properties of Ge-Substituted Filled Skutterudite Compounds; LnxCo4Sb12−yGey, Ln = La, Ce, Pr, and Nd

    Directory of Open Access Journals (Sweden)

    Hiroshi Fukuoka


    Full Text Available A series of new Ge-substituted skutterudite compounds with the general composition of LnxCo4Sb12−yGey, where Ln = La, Ce, Pr, and Nd, is prepared by high-pressure and high-temperature reactions at 7 GPa and 800 °C. They have a cubic unit cell and the lattice constant for each compound is 8.9504 (3, 8.94481 (6, 8.9458 (3, and 8.9509 (4 Å for the La, Ce, Pr, and Nd derivatives, respectively. Their chemical compositions, determined by electron prove microanalysis, are La0.57Co4Sb10.1Ge2.38, Ce0.99Co4Sb9.65Ge2.51, Pr0.97Co4Sb9.52Ge2.61, and Nd0.87Co4Sb9.94Ge2.28. Their structural parameters are refined by Rietveld analysis. The guest atom size does not affect the unit cell volume. The Co–Sb/Ge distance mainly determines the unit cell size as well as the size of guest atom site. The valence state of lanthanide ions is 3+.

  15. Mixed-valence metal oxide nanoparticles as electrochemical half-cells: substituting the Ag/AgCl of reference electrodes by CeO(2-x) nanoparticles. (United States)

    Nagarale, Rajaram K; Hoss, Udo; Heller, Adam


    Cations of mixed valence at surfaces of metal oxide nanoparticles constitute electrochemical half-cells, with potentials intermediate between those of the dissolved cations and those in the solid. When only cations at surfaces of the particles are electrochemically active, the ratio of electrochemically active/all cations is ~0.1 for 15 nm diameter CeO(2-x) particles. CeO(2-x) nanoparticle-loaded hydrogel films on printed carbon and on sputtered gold constitute reference electrodes having a redox potential similar to that of Ag/AgCl in physiological (0.14 M) saline solutions. In vitro the characteristics of potentially subcutaneously implantable glucose monitoring sensors made with CeO(2-x) nanoparticle reference electrodes are undistinguishable from those of sensors made with Ag/AgCl reference electrodes. Cerium is 900 times more abundant than silver, and commercially produced CeO(2-x) nanoparticle solutions are available at prices well below those of the Ag/AgCl pastes used in the annual manufacture of ~10(9) reference electrodes of glucose monitoring strips for diabetes management.

  16. Rapid Genotyping of the Human Renin (REN Gene by the LightCycler® Instrument: Identification of Unexpected Nucleotide Substitutions within the Selected Hybridization Probe Area

    Directory of Open Access Journals (Sweden)

    Line Wee


    Full Text Available Preeclampsia is a serious disorder affecting nearly 3% of all in the Western world. It is associated with hypertension and proteinuria, and several lines of evidence suggest that the renin-angiotensin system (RAS may be involved in the development of hypertension at different stages of a preeclamptic pregnancy. In this study, we developed rapid genotyping assays on the LightCycler® instrument to allow the detection of genetic variants in the renin gene (REN that may predispose to preeclampsia. The method is based on real-time PCR and allele-specific hybridization probes, followed by fluorescent melting curve analysis to expose a change in melting temperature (Tm. Ninety-two mother-father-child triads (n=276 from preeclamptic pregnancies were genotyped for three haplotype-tagging single nucleotide polymorphisms (htSNPs in REN. All three htSNPs (rs5705, rs1464816 and rs3795575 were successfully genotyped. Furthermore, two unexpected nucleotide substitutions (rs11571084 and rs61757041 were identified within the selected hybridization probe area of rs1464816 and rs3795575 due to aberrant melting peaks. In conclusion, genotyping on the LightCycler® instrument proved to be rapid and highly reproducible. The ability to uncover additional nucleotide substitutions is particularly important in that it allows the identification of potentially etiological variants that might otherwise be overlooked by other genotyping methods.

  17. Probing competitive enantioselective approach vectors operating in the Jacobsen-Katsuki epoxidation: a kinetic study of methyl-substituted styrenes. (United States)

    Fristrup, Peter; Dideriksen, Brian B; Tanner, David; Norrby, Per-Ola


    This paper describes a study of reactivity and enantioselectivity for a series of methyl-substituted styrenes in the Jacobsen-Katsuki (Mn(salen)-catalyzed) epoxidation reaction. Competition experiments provided kinetic data for the reactivity of the seven possible methyl-substituted styrenes (mono-, di- and trisubstituted) relative to styrene itself, ee values were measured by chiral GC, and absolute configurations were secured by chemical correlation. Of particular interest was the switch in absolute configuration at the benzylic position of the epoxides derived from (Z)- and (E)-alpha,beta-dimethylstyrene, respectively. The results could be rationalized in terms of an approach vector with the phenyl substituent proximal to the salen. As opposed to alkyl groups, a proximal phenyl group has very little effect on the rate of the reaction. Consideration of distal vs proximal approach allows prediction of absolute stereochemistry as a function of alkene substitution pattern. Trisubstituted alkenes with one phenyl group cis to the alkene hydrogen can be identified as a favored substrate class in the title reaction, with both rate and selectivity close to the classic (Z)-beta-substituted styrene substrates.

  18. Enhancing the blue shift of SHG signal in GaSe:B/Ce crystal (United States)

    Karatay, Ahmet; Yuksek, Mustafa; Ertap, Hüseyin; Elmali, Ayhan; Karabulut, Mevlut


    The influence of Ce3+ on the wavelength of second harmonic generation (SHG) signal in boron doped GaSe crystals have been investigated. We found that by substitution of Ce3+ with B3+, SHG signal shifted to lower wavelength. In addition, the nonlinear absorption (NA) properties and ultrafast dynamics of pure, 1 at.% B3+ and 0.5 at.% B3++ 0.5 at.% Ce3+ doped GaSe crystals have been studied by open aperture Z-scan and ultrafast pump probe spectroscopy techniques. From the open aperture Z-scan experiments we observed that all of the crystals showed nonlinear absorption (NA). However, pump-probe experiments revealed that when GaSe crystal is doped, the NA signal turns into a bleaching signal with different lifetimes depending on the type and concentration of the dopant atoms.

  19. Highly selective and sensitive fluorogenic ferric probes based on aggregation-enhanced emission with - SiMe3 substituted polybenzene (United States)

    Wang, Xuefeng; Wang, Hua; Jiang, Qin; Lee, Yong-Ill; Feng, Shengyu; Liu, Hong-Guo


    In this study, thiophene was linked to polybenzene to generate novel fluorescent probes, namely 3,4-diphenyl-2,5-di(2-thienyl)phenyl-trimethylsilane (DPTB-TMS) with a - SiMe3 substituent and 3,4-diphenyl-2,5-di(2-thienyl)phenyl (DPTB) without the - SiMe3 substituent, respectively. Both of the two compounds exhibit aggregation-enhanced emission (AEE) properties in tetrahydrofuran/water mixtures due to restricted intramolecular rotation of the peripheral groups, which make the two compounds good candidates for the detection of Fe3 + ions in aqueous-based solutions. The fluorescence intensity of the two compounds decreases immediately and obviously upon addition of a trace amount of Fe3 +, and decreases continuously as the amount of Fe3 + increases. The fluorescence was quenched to 92% of its initial intensity when the amount of Fe3 + ions reached 6 μmol for DPTB-TMS and to 80% for DPTB in the systems, indicating that the compound with the - SiMe3 group is a more effective probe. The detection limit was found to be 1.17 μM (65 ppb). The detection mechanism is proposed to be static quenching. DPTB-TMS is highly efficient for the detection of ferric ions even in the presence of other metal ions. In addition, the method is also successfully applied to the detection of ferric ions in water, blood serum, or solid films. This indicates that these polybenzene compounds can be applied as low-cost, high selectivity, and high efficiency Fe3 + probes in water or in clinical applications.

  20. The superconducting gap structure of PrOs{sub 4}Sb{sub 12} and CeRu{sub 2} probed by C(H,{phi})

    Energy Technology Data Exchange (ETDEWEB)

    Custers, J. [Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 (Japan) and Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna (Austria)]. E-mail:; Yamada, A. [Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 (Japan); Tayama, T. [Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 (Japan); Sakakibara, T. [Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 (Japan); Sugawara, H. [Faculty of Integrated Arts and Sciences, University of Tokushima, Tokushima 770-8502 (Japan); Aoki, Y. [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan); Sato, H. [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan); Onuki, Y. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Machida, K. [Department of Physics, Okayama University, Okayama 700-8530 (Japan)


    We have performed measurements of the angle-resolved specific heat C(H,{phi}) on PrOs{sub 4}Sb{sub 12} and the well-known s-wave superconductor CeRu{sub 2} in order to gain information about their respective superconducting (SC) gap structure. PrOs{sub 4}Sb{sub 12} exhibits pronounced minima (maxima) in C(H,{phi}) along the [100] ([111]) directions. CeRu{sub 2} shows minima (maxima) along the [110] ([100]) directions. The field dependence of the oscillation amplitude of C({phi}), vertical bar A vertical bar, shows similar behavior for both suggesting finite minima in the SC gap, where C({phi}) is smallest. On the other hand, in comparison the temperature dependence of |A| shows aberrant behavior.

  1. Highly Selective and Sensitive Detection of Cu(2+) Ions Using Ce(III)/Tb(III)-Doped SrF2 Nanocrystals as Fluorescent Probe. (United States)

    Sarkar, Shyam; Chatti, Manjunath; Adusumalli, Venkata N K B; Mahalingam, Venkataramanan


    We report a green synthetic approach to the synthesis of water dispersible Ce(3+)/Tb(3+)-doped SrF2 nanocrystals, carried out using environment friendly microwave irradiation with water as solvent. The nanocrystals display strong green emission due to energy transfer from Ce(3+) to Tb(3+) ions. This strong green emission from Tb(3+) ions is selectively quenched upon addition of Cu(2+) ions, thus making the nanocrystals a potential Cu(2+) ions sensing material. There is barely any interference by other metal ions on the detection of Cu(2+) ions and the detection limit is as low as 2 nM. This sensing ability is highly reversible by the addition of ethylenediaminetetraacetic acid (EDTA) with the recovery of almost 90% of the original luminescence. The luminescence quenching and recovery cycle was repeated multiple times without much effect on the sensitivity. The study was extended to real world water samples and obtained similar results. In addition to the sensing, we strongly predict the small size and high luminescence of the Ce(3+)/Tb(3+)-doped SrF2 nanocrystals can be used for bioimaging applications.

  2. Influence of the substitution of Y2O3 for CeO2 on the mechanical and microstructural properties of silicon nitride Influência da substituição de Y2O3 por CeO2 nas propriedades mecânicas e microestruturais do nitreto de silício

    Directory of Open Access Journals (Sweden)

    J. V. C. de Souza


    Full Text Available This work investigated the substitution of Y2O3 for CeO2 in liquid-phase sintered silicon nitride ceramics. Cost reduction as well as good physical, mechanical and microstructural properties are the main objectives of the present study. Two powder mixtures were prepared, varying the contents of alpha-Si3N4, Al2O3, AlN, Y2O3 and CeO2. The mixtures were homogenized in ethanol, dried in a rotating evaporator and kiln, respectively, and then uniaxially (100 MPa and cold isostatically pressed (300 MPa. The samples were sintered at 1850ºC for 1 h in a graphite resistive furnace under nitrogen atmosphere. After sintering the density of the samples was higher than 97% of the theoretical value. The fracture toughness and hardness were higher than 5.28 MPa.m½ and 17.12 GPa, respectively. Phase analysis by X-ray diffraction and scanning electron microscopy revealed the presence of alpha-SiAlON and beta-Si3N4.Este trabalho foi proposto com objetivo de analisar a possibilidade da substituição de Y2O3 por CeO2 sinterização via fase líquida de nitreto de silício (Si3N4, visando obter um material com boas propriedades físicas, mecânicas e microestruturais, além da redução de custos de produção desta cerâmica. Para o desenvolvimento deste trabalho foram preparadas duas misturas de pós, variando-se as proporções entre alfa-Si3N4, Al2O3, AlN, Y2O3 e CeO2. As misturas de pós foram homogeneizadas em etanol, secas em evaporador rotativo e estufa, respectivamente. Em seguida, prensadas uniaxialmente (100 MPa e isostaticamente a frio(300 MPa. As amostras foram sinterizadas à 1850 ºC durante 1 h, em forno com elemento resistivo de grafite sob atmosfera de nitrogênio. Após sinterização, as amostras apresentaram densidades relativas superiores a 97% do valor teórico. A tenacidade à fratura e a dureza foram superiores a 5,28 MPa.m½ e 17,12 GPa, respectivamente. As análises de fases por difração de raios X e microscopia eletrônica de

  3. Magnetic and superconducting properties of an S -type single-crystal CeCu2Si2 probed by 63Cu nuclear magnetic resonance and nuclear quadrupole resonance (United States)

    Kitagawa, Shunsaku; Higuchi, Takumi; Manago, Masahiro; Yamanaka, Takayoshi; Ishida, Kenji; Jeevan, H. S.; Geibel, C.


    We have performed 63Cu nuclear-magnetic-resonance/nuclear-quadrupole-resonance measurements to investigate the magnetic and superconducting (SC) properties on a "superconductivity dominant" (S -type) single crystal of CeCu2Si2 . Although the development of antiferromagnetic (AFM) fluctuations down to 1 K indicated that the AFM criticality was close, Korringa behavior was observed below 0.8 K, and no magnetic anomaly was observed above Tc˜0.6 K. These behaviors were expected in S -type CeCu2Si2 . The temperature dependence of the nuclear spin-lattice relaxation rate 1 /T1 at zero field was almost identical to that in the previous polycrystalline samples down to 130 mK, but the temperature dependence deviated downward below 120 mK. In fact, 1 /T1 in the SC state could be fitted with the two-gap s±-wave model rather than the two-gap s++-wave model down to 90 mK. Under magnetic fields, the spin susceptibility in both directions clearly decreased below Tc, which is indicative of the formation of spin-singlet pairing. The residual part of the spin susceptibility was understood by the field-induced residual density of states evaluated from 1 /T1T , which was ascribed to the effect of the vortex cores. No magnetic anomaly was observed above the upper critical field Hc 2, but the development of AFM fluctuations was observed, indicating that superconductivity was realized in strong AFM fluctuations.

  4. Magnetic and superconducting properties of a heavy-fermion CeCoIn5 epitaxial film probed by nuclear quadrupole resonance (United States)

    Yamanaka, Takayoshi; Shimozawa, Masaaki; Shishido, Hiroaki; Kitagawa, Shunsaku; Ikeda, Hiroaki; Shibauchi, Takasada; Terashima, Takahito; Matsuda, Yuji; Ishida, Kenji


    Since the progress in the fabrication techniques of thin films of exotic materials such as strongly correlated heavy-fermion compounds, microscopic studies of the magnetic and electronic properties inside the films have been needed. Herein, we report the observation of 115In nuclear quadrupole resonance (NQR) in an epitaxial film of the heavy-fermion superconductor CeCoIn5, for which the microscopic field gradient within the unit cell as well as magnetic and superconducting properties at zero field are evaluated. We find that the nuclear spin-lattice relaxation rate in the film is in excellent agreement with that of bulk crystals, whereas the NQR spectra show noticeable shifts and significant broadening indicating a change in the electric-field distribution inside the film. The analysis implies a displacement of In layers in the film, which, however, does not affect the magnetic fluctuations and superconducting pairing. This implies that inhomogeneity of the electronic field gradient in the film sample causes no pair-breaking effect.

  5. Oxidation state of Ce in the sandwich molecule cerocene

    Energy Technology Data Exchange (ETDEWEB)

    Edelstein, N.M.; Allen, P.G.; Bucher, J.J.; Shuh, D.K.; Sofield, C.D. [Lawrence Berkeley National Lab., CA (United States); Kaltsoyannis, N.; Maunder, G.H.; Russo, M.R.; Sella, A. [Univ. College London (United Kingdom)


    This paper reports measurements of the XANES spectra of various substituted cerocenes, related trivalent cerocene salts, and some Ce standard compounds in order to determine the formal oxidation state of the Ce ion in substituted cerocenes. The Ce ion in the substituted cerocenes appears to be less electron-rich than in their alkali metal salts, as shown by a 4.5 eV shift toward higher oxidation state of their X-ray K-edges. This argument is supported by structural data which show the Ce ring centroid distance for the substituted cerocenes is {approx}1.97 A as compared to {approx}2.07 A for the K[Ce(COT){sub 2}] diglyme salt. 31 refs., 2 figs.

  6. Probing structural changes in the alpha and beta domains of copper- and silver-substituted metallothionein by emission spectroscopy and electrospray ionization mass spectrometry. (United States)

    Salgado, Maria T; Bacher, Kristy L; Stillman, Martin J


    Steady-state emission spectra, excited-state lifetimes, kinetic data, and mass spectroscopic properties are reported for Ag(I)- and mixed Ag(I)/Cu(I)-substituted alpha and beta domains of recombinant human metallothionein (MT1a). Kinetic analysis of the changes in the Cu(I) emission spectra during the stepwise displacement of Cu(I) ions by Ag(I) at room temperature shows that the rate of displacement of Cu(I) is unexpectedly slow. Although the first Ag(I) added results in major changes in the Cu(I)-MT binding site, Cu(I) displacement by Ag(I) does not take place until the addition of the third Ag(I), and is completed by the addition of the seventh Ag(I). The emission from Ag(I) and mixed Cu(I)/Ag(I)-MT species at 77 K shows that the band maxima shift as a function of Ag(I) loading, which can be correlated with shifts in coordination geometry from trigonal to digonal. Two phosphorescence lifetimes were detected for the Ag(I)-substituted alpha and beta domains of MT, which are attributed to the presence of Ag(I) ions in two different environments. The lifetime of Ag(I)-substituted MT was found to be shorter when the Ag(I)-MT species were formed by Ag(I) additions to the Cu(I)-substituted alpha and beta fragments than when the Ag(I)-MT species were formed from the apo-alpha and apo-beta fragments, suggesting the formation of structurally different Ag(I)-MT clusters. Electrospray ionization mass spectrometric studies suggest the metallation reactions of Ag(I) with MT take place in a series of steps to form a series of Ag(I)-substituted MT species. Ag(I)-substituted MT species are not detected until past the addition of 3 mol equiv of Ag(I), suggesting that cluster formation begins only at this point, stabilizing the metallated species sufficiently to survive ionization.

  7. Pd-Catalyzed Carbonylative Carboperfluoroalkylation of Alkynes. Through-Space13C-19F Coupling as a Probe for Configuration Assignment of Fluoroalkyl-Substituted Olefins. (United States)

    Domański, Sylwester; Staszewska-Krajewska, Olga; Chaładaj, Wojciech


    A four-component Pd-catalyzed protocol for direct synthesis of perfluoroalkyl-substituted enones is reported. Under mild conditions and low catalyst loading, alkynes, iodoperfluoroalkanes, (hetero)arylboronic acids, and carbon monoxide are assembled into highly elaborate products with good yields and excellent regio- and stereoselectivities. The configuration of the products was confirmed by the observation of through-space 13 C- 19 F couplings, accessible through the analysis of routine 13 C NMR spectra.

  8. Oxygen Transfer on Substituted ZrO2, Bi2O3, and CeO2 Electrolytes with Platinum Electrodes. I. Electrode Resistance by D-C Polarization

    NARCIS (Netherlands)

    Verkerk, M.J.; Hammink, W.J.; Burggraaf, A.J.


    The electrode behavior of Pt-sputtered and PT-gauze electrodes on ZrO2-Y2O3, Bi2O3-Er2O3, and CeO2-Gd2O3 solid electrolyteswas investigated by means of d-c measurements in the temperature region of 770–1050 K and in the oxygen partialpressure region of 10–5 – 1 atm O2 using N2-O2 mixtures. On these

  9. Characteristics of martensitic and strain-glass transitions of the Fe-substituted TiNi shape memory alloys probed by transport and thermal measurements. (United States)

    Ramachandran, Balakrishnan; Chang, Pei-Chi; Kuo, Yung-Kang; Chien, Chen; Wu, Shyi-Kaan


    The electrical resistivity, Seebeck coefficient, thermal conductivity, and specific heat of Ti50Ni50-x Fe x (x = 2.0-10.0 at.%) shape memory alloys (SMAs) were measured to investigate the influence of point defects (Fe) on the martensitic transformation characteristics. Our results show that the Ti50Ni48Fe2 and Ti50Ni47Fe3 SMAs have a two-step martensitic transformation (B2 → R and R → B19'), while the Ti50Ni46Fe4, Ti50Ni44.5Fe5.5, and Ti50Ni44Fe6 SMAs display a one-step martensitic transition (B2 → R). However, the compounds Ti50Ni42Fe8 and Ti50Ni40Fe10 show strain glass features (frozen strain-ordered state). Importantly, the induced point defects significantly alter the martensitic transformation characteristics, namely transition temperature and width of thermal hysteresis during the transition. This can be explained by the stabilization of austenite B2 phase upon Fe substitution, which ultimately leads to the decrease in enthalpy that associated to the martensitic transition. To determine the boundary composition that separates the R-phase and strain glass systems in this series of SMAs, a Ni-rich specimen Ti49Ni45Fe6 was fabricated. Remarkably, a slight change in Ti/Ni ratio converts Ti49Ni45Fe6 SMA into a strain glass system. Overall, the evolution of phase transformation in the Fe-substituted TiNi SMAs is presumably caused by the changes in local lattice structure via the induced local strain fields by Fe point defects.

  10. Synthesis and evaluation of 17alpha-20E-21-(4-substituted phenyl)-19-norpregna-1,3,5(10),20-tetraene-3,17beta-diols as probes for the estrogen receptor alpha hormone binding domain. (United States)

    Hanson, Robert N; Lee, Choon Young; Friel, Carolyn J; Dilis, Robert; Hughes, Alun; DeSombre, Eugene R


    As part of our program to develop probes for the hormone binding domain of the estrogen receptor alpha (ERalpha), we prepared a series of 4-para-substituted phenylvinyl estradiol derivatives using a combination of solution and solid-phase Pd(0)-catalyzed methods. The compounds 5a-j were evaluated for their binding affinity using the ERalpha hormone binding domain (HDB) isolated from transfected BL21 cells. The results indicated that although the new compounds were somewhat lower in relative binding affinity (RBA at 25 degrees C is 1-60%) than estradiol (100%), most had higher affinity than the unsubstituted parent phenylvinyl estradiol (RBA = 9%). Because the substituents did not generate a structure-activity relationship directly based on physicochemical properties, the series was evaluated using molecular modeling and molecular dynamics to determine key interactions between the ligand, especially the para substituent, and the protein. The results suggest that the observed relative binding affinities are directly related to the calculated binding energies and that amino acids juxtaposed to the para position play a significant but not dominant role in binding. In conclusion, we have identified the 17alpha-E-(4-substituted phenyl)vinyl estradiols as a class of ligands that retain significant affinity for the ERalpha-HBD. In particular, 4-substitution tends to increase receptor affinity compared to the unsubstituted analogue, as exemplified by 5e (4-COCH(3)), which had the highest RBA value (60%) of the series. Palladium(0)-catalyzed coupling reactions on solid support or in solution using suitably substituted iodo arenes and 17alpha-E-tributylstannylvinyl estradiols offer a flexible approach to their preparation. Molecular modeling studies of the receptor suggest that there exists additional ligand accessible regions within the ERalpha-HBD to generate interactions that may enhance receptor affinity or modify efficacy in developing new therapeutic agents. Studies to

  11. Room temperature redox reaction by oxide ion migration at carbon/Gd-doped CeO2 heterointerface probed by an in situ hard x-ray photoemission and soft x-ray absorption spectroscopies

    Directory of Open Access Journals (Sweden)

    Takashi Tsuchiya, Shogo Miyoshi, Yoshiyuki Yamashita, Hideki Yoshikawa, Kazuya Terabe, Keisuke Kobayashi and Shu Yamaguchi


    Full Text Available In situ hard x-ray photoemission spectroscopy (HX-PES and soft x-ray absorption spectroscopy (SX-XAS have been employed to investigate a local redox reaction at the carbon/Gd-doped CeO2 (GDC thin film heterointerface under applied dc bias. In HX-PES, Ce3d and O1s core levels show a parallel chemical shift as large as 3.2 eV, corresponding to the redox window where ionic conductivity is predominant. The window width is equal to the energy gap between donor and acceptor levels of the GDC electrolyte. The Ce M-edge SX-XAS spectra also show a considerable increase of Ce3+ satellite peak intensity, corresponding to electrochemical reduction by oxide ion migration. In addition to the reversible redox reaction, two distinct phenomena by the electrochemical transport of oxide ions are observed as an irreversible reduction of the entire oxide film by O2 evolution from the GDC film to the gas phase, as well as a vigorous precipitation of oxygen gas at the bottom electrode to lift off the GDC film. These in situ spectroscopic observations describe well the electrochemical polarization behavior of a metal/GDC/metal capacitor-like two-electrode cell at room temperature.

  12. Improving CE with PDM

    NARCIS (Netherlands)

    Wognum, P.M.; Bondarouk, Tatiana; Weber, F; Pawar, K.S.; Thoben, K.D.


    The concept of Concurrent Engineering (CE) centers around the management of information so that the right information will be at the right place at the right time and in the right format. Product Data Management (PDM) aims to support a CE way of working in product development processes. In specific

  13. Synthesis and structure of cerium-substituted hydroxyapatite. (United States)

    Feng, Zude; Liao, Yingmin; Ye, Meng


    The aim of this study was to explore the effect of cerium ions on the formation and structure of hydroxyapatite (HAP). All particles, prepared by hydrothermal method, were synthesized at varied X(Ce) = Ce/(Ca + Ce) (from 0 to 10%) with the atomic ratio (Ce + Ca)/P fixed at 1.67. Their morphology, composition and crystal structure were characterized by TEM, EPMA, XRD and FTIR. The results showed that in this composition range the apatite structure is maintained, Ce3+ ions could enter the crystal lattice of apatite and substitute Ca2+ ions. The doping of Ce3+ ions resulted in the decrease of the crystallite size with increase in X(Ce). The HAP particles without doping were short rods having a diameter from 10 to 20 nm and a length from 30 to 50 nm. They grew into long needles upon increasing X(Ce).

  14. Substitutional analysis

    CERN Document Server

    Rutherford, Daniel Edwin


    Classic monograph, suitable for advanced undergraduates and graduate students. Topics include calculus of permutations and tableaux, semi-normal representation, orthogonal and natural representations, group characters, and substitutional equations. 1968 edition.

  15. Hydrogen-bridge Si(μ-H)3CeH and inserted H3SiCeH molecules: Matrix infrared spectra and DFT calculations for reaction products of silane with Ce atoms (United States)

    Xu, Bing; Shi, Peipei; Huang, Tengfei; Wang, Xuefeng


    Reactions of laser-ablated cerium atoms with silane were investigated by matrix isolation infrared spectroscopy and theoretical calculations. The reaction products, Si(μ-H)3CeH, H3SiCeH, H2Si(μ-H)CeH and HSi(μ-H)2CeH were identified on the basis of the SiD4 isotopic substitutions and DFT frequency calculations. In the solid argon or krypton matrix, the inserted H3SiCeH molecule was observed as initial product on deposition, which rearranged to hydrogen bridge species Si(μ-H)3CeH on follow-up annealing through H2Si(μ-H)CeH and HSi(μ-H)2CeH species. The Sisbnd Hsbnd Ce hydrogen bridge was investigated by NBO and ELF analysis. Calculation suggested that in Si(μ-H)3CeH molecule Ce atom donated one electron to Si atom, resulting in electron-rich SiH3 subunit, which was confirmed by ESP and AIM analysis. The increased basicity of Sisbnd H bond facilitates the formation of hydrogen bridge bond between Si and Ce. For comparison only insertion H3CCeH structure was obtained from the reaction of Ce atoms with CH4.

  16. Distinct roles of carbohydrate esterase family CE16 acetyl esterases and polymer-acting acetyl xylan esterases in xylan deacetylation

    NARCIS (Netherlands)

    Koutaniemi, S.; Gool, van M.P.; Juvonen, M.; Hinz, S.W.A.; Schols, H.A.; Tenkanen, M.


    Mass spectrometric analysis was used to compare the roles of two acetyl esterases (AE, carbohydrate esterase family CE16) and three acetyl xylan esterases (AXE, families CE1 and CE5) in deacetylation of natural substrates, neutral (linear) and 4-O-methyl glucuronic acid (MeGlcA) substituted

  17. Tonemic Substitution

    African Journals Online (AJOL)


    Le Cameroun est un pays bilingue grâce au fait qu'il a été colonisé par la France et la Grande Bretagne après la Première. Guerre Mondiale. Ces deux puissances occidentales ont introduit dans le pays deux systèmes éducatifs si différents. Parmi des lois votées pour reformer ces deux systèmes nous citons la loi no.

  18. Solvent substitution

    Energy Technology Data Exchange (ETDEWEB)


    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

  19. Variation of coercivity with Ce content in (Pr,Nd,Ce2Fe14B sintered magnets

    Directory of Open Access Journals (Sweden)

    Xue-feng Zhang


    Full Text Available The variation of coercivity with Ce content was investigated in (Pr,Nd15-xCexFe77B8 (x=0∼10 sintered magnets. The coercivity of magnets largely decreases from 10.22 to 5.4 kOe with increasing x from 0 to 2. The coercivity rises to 7.68 kOe when x=3 and then decreases again with further increasing Ce content. However, both the magnetocrystalline anisotropy and Curie temperature decrease monotonically with increasing Ce content. EDS composition analysis shows that the Ce concentration in the Re2Fe14B main phase is higher than that in the nominal composition when x≤3, but becomes lower when x>3. These results indicate that Ce tends to be expelled from the main phase and segregates at or near the grain boundary regions if Pr-Nd is excessively substituted by Ce. The change of relative solubility of Ce in Re2Fe14B would lead to the change of distributions of Ce and Pr-Nd elements, and thus result in the change of anisotropy at the grain outer layer, contributing to the abnormal behavior of coercivity. These studied results are also expected to provide a guideline for optimizing the composition design of resource-saving permanent magnets.

  20. Mobile Probing and Probes

    DEFF Research Database (Denmark)

    Duvaa, Uffe; Ørngreen, Rikke; Weinkouff Mathiasen, Anne-Gitte


    Mobile probing is a method, developed for learning about digital work situations, as an approach to discover new grounds. The method can be used when there is a need to know more about users and their work with certain tasks, but where users at the same time are distributed (in time and space......). Mobile probing was inspired by the cultural probe method, and was influenced by qualitative interview and inquiry approaches. The method has been used in two subsequent projects, involving school children (young adults at 15-17 years old) and employees (adults) in a consultancy company. Findings point...... to mobile probing being a flexible method for uncovering the unknowns, as a way of getting rich data to the analysis and design phases. On the other hand it is difficult to engage users to give in depth explanations, which seem easier in synchronous dialogs (whether online or face2face). The development...

  1. Mobile Probing and Probes

    DEFF Research Database (Denmark)

    Duvaa, Uffe; Ørngreen, Rikke; Weinkouff, Anne-Gitte


    and space). Mobile probing was inspired by the cultural probe method, and was influenced by qualitative interview and inquiry approaches. The method has been used in two subsequent projects, involving school children (young adults at 15-17 years old) and employees (adults) in a consultancy company. Findings......Mobile probing is a method, which has been developed for learning about digital work situations, as an approach to discover new grounds. The method can be used when there is a need to know more about users and their work with certain tasks, but where users at the same time are distributed (in time...... point to mobile probing being a flexible method for uncovering the unknowns, as a way of getting rich data to the analysis and design phases. On the other hand it is difficult to engage users to give in depth explanations, which seem easier in synchronous dialogs (whether online or face2face...

  2. Ce3+/Eu2+ doped SrSc2O4 phosphors: Synthesis, luminescence and energy transfer from Ce3+ to Eu2+ (United States)

    Zhao, Jitao; Sun, Xiaoyu; Wang, Zhenqing


    Ce3+/Eu2+ doped SrSc2O4 phosphors were synthesized by a solid state reaction. The phase and luminescent properties of the synthesized phosphors were investigated. In SrSc2O4 host, Ce3+/Eu2+ substitute Sr2+ sites and form the solid solution. Ce3+/Eu2+ singly doped SrSc2O4 phosphors respectively show emission band locating in green and deep red regions and the emission peaks shift to longer wavelength with the increasing concentration due to the enhancements of crystal field. In Ce3+/Eu2+ codoped SrSc2O4 phosphors, the intensities of Ce3+ and Eu2+ emissions change with the changing Eu2+ concentrations due to energy transfer from Ce3+ to Eu2+.

  3. CE-BEMS

    DEFF Research Database (Denmark)

    Mohamed, Nader; Lazarova-Molnar, Sanja; Al-Jaroodi, Jameela


    and costs savings in smart buildings significantly depend on the monitoring and control methods used in the installed BEMS. This paper proposes a Cloud-Enabled BEMS (CE-BEMS) for Smart Buildings. This system can utilize cloud computing to provide enhanced management mechanisms and features for energy...... savings in smart buildings. This system is connected to the cloud to have access to a number of advanced cloud-based services to enhance energy management in smart buildings. In this paper, we discuss the current limitations of BEMS, the conceptual design of the proposed system, and the advantages...

  4. Simple, heart-smart substitutions (United States)

    Coronary artery disease - heart smart substitutions; Atherosclerosis - heart smart substitutions; Cholesterol - heart smart substitutions; Coronary heart disease - heart smart substitutions; Healthy diet - heart ...

  5. Emission properties of Ce-doped alkaline earth borate glasses for scintillator applications (United States)

    Torimoto, Aya; Masai, Hirokazu; Okada, Go; Kawaguchi, Noriaki; Yanagida, Takayuki


    We investigate the photoluminescence (PL) and X-ray-induced luminescence properties of 0.1 mol% Ce-doped MO-B2O3 (M = Ca, Sr, and Ba) glasses. We also determine the Ce3+/(Ce3++Ce4+) ratio by X-ray absorption near-edge structure analyses. The emission intensities of PL, X-ray scintillation, and thermally stimulated luminescence (TSL) depend on the host glass composition. The order of the PL intensity from highest to lowest is as follows: Ca-substituted glass, Ba-substituted glass, and Sr-substituted glass. Our results suggest that the optical absorption edge and quantum yield (QY) are influenced by the local coordination state of Ce3+, which, in turn, is likely to be affected by the optical basicity. The order of the X-ray scintillation intensity from highest to lowest is reverse of that of the PL intensity. This is probably because the interaction probability of X-rays with matter depends on the effective atomic number of the material and the effective atomic number has a stronger influence on the scintillation intensity than does the QY. Though the TSL glow curves reveal that the density and energy depth of the trap sites depend on the substituted alkaline earth oxides, we are unable to correlate the electron spin resonance (ESR) spectra with the TSL results. Therefore, it is considered that the ESR active sites are not responsible for the TSL in these systems.

  6. High-resolution structural characterization and magnetic properties of epitaxial Ce-doped yttrium iron garnet thin films (United States)

    Li, Zhong; Vikram Singh, Amit; Rastogi, Ankur; Gazquez, Jaume; Borisevich, Albina Y.; Mishra, Rohan; Gupta, Arunava


    Thin films of magnetic garnet materials, e.g. yttrium iron garnet (Y3Fe5O12, YIG), are useful for a variety of applications including microwave integrated circuits and spintronics. Substitution of rare earth ions, such as cerium, is known to enhance the magneto-optic Kerr effect (MOKE) as compared to pure YIG. Thin films of Ce0.75Y2.25Fe5O12 (Ce:YIG) have been grown using the pulsed laser deposition (PLD) technique and their crystal structure examined using high resolution scanning transmission electron microscopy. Homogeneous substitution of Ce in YIG, without oxidation to form a separate CeO2 phase, can be realized in a narrow process window with resulting enhancement of the MOKE signal. The thermally generated signal due to spin Seebeck effect for the optimally doped Ce:YIG films has also been investigated.

  7. Influence of Ce/sup 3 +/. -->. Ce/sup 4 +/ electron transition on thermo-e. m. f. in Ce(Cusub(x)Nisub(1-x))sub(5) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Lutsiv, R.V.; Koterlin, M.D.; Babich, O.I.; Bodak, O.I. (L' vovskij Gosudarstvennyj Univ. (Ukrainian SSR))


    The coefficient of thermo-e.m.f. system (..cap alpha..)Ce(Cusub(x)Nisub(1-x))sub(5) with valent transition Ce/sup 3 +/ ..-->.. Ce/sup 4 +/, initiated by the change in composition is investigated. The temperature dependence ..cap alpha.. with two feebly marked extrema is revealed which are caused by charge carriers scattering on 4f Ce states forming the peaks of high state density in the Fermi region is obtained. Consequent copper substitution for nickel leads to the shift of high-temperature extremum position into the low-temperature region. For transitional composition x=0.4 the highest sensitivity to the temperature and maximum thermo-e.m.f. absolute values are observed.

  8. Cultural probes

    DEFF Research Database (Denmark)

    Madsen, Jacob Østergaard

    The aim of this study was thus to explore cultural probes (Gaver, Boucher et al. 2004), as a possible methodical approach, supporting knowledge production on situated and contextual aspects of occupation.......The aim of this study was thus to explore cultural probes (Gaver, Boucher et al. 2004), as a possible methodical approach, supporting knowledge production on situated and contextual aspects of occupation....

  9. Substitute family care


    Petrů, Jaroslava


    The bachelor thesis focuses on substitute family care in the Czech Republic and its importance for the child. The theoretical part defines the basic terms, describes history and the forms of substitute family care. It also deals with the process of placing a child in substitute family care, the preparation of foster parents and the legislation regulating substitute family care. The practical part is based on qualitative research in families with children in foster and tutelary care, in famili...

  10. Magnetic field study of Ce{sub 0.8}La{sub 0.2}Al{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Pietri, R. [Physics Department, University of Florida, P.O. Box 118440, Gainesville, Florida 32611-8440 (United States); Kumar, P. [Physics Department, University of Florida, P.O. Box 118440, Gainesville, Florida 32611-8440 (United States); Andraka, B. [Physics Department, University of Florida, P.O. Box 118440, Gainesville, Florida 32611-8440 (United States)


    A partial substitution of La for Ce in CeAl{sub 3} leads to large anomalies in the low temperature specific heat, presumably of magnetic origin, and results in a strong reduction of {gamma}. Magnetic fields up to 14 T have little effect on the temperature position of the anomaly in Ce{sub 0.8}La{sub 0.2}Al{sub 3} but attenuate its magnitude. Specific heats of Ce{sub 0.8}La{sub 0.2}Al{sub 3} and CeAl{sub 3} approach each other in large fields of order 14 T. Magnetic fields increase {gamma} of Ce{sub 0.8}La{sub 0.2}Al{sub 3}. (c) 2000 American Institute of Physics.

  11. Magnetic order in CePd{sub 1-x}Ni{sub x}Al

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, Stefan; Huesges, Zita; Woitschach, Sarah; Stockert, Oliver [Max Planck Institute CPfS, Dresden (Germany); Sakai, Akito [University of Augsburg, Augsburg (Germany); Fritsch, Veronika [University of Augsburg, Augsburg (Germany); Karlsruhe Institute of Technology, Karlsruhe (Germany); Loehneysen, Hilbert von [Karlsruhe Institute of Technology, Karlsruhe (Germany)


    CePd{sub 1-x}Ni{sub x}Al is a heavy-fermion system, which shows both, geometric frustration arising from the hexagonal crystal structure and quantum critical behavior. By substituting palladium with nickel the Neel temperature of T{sub N} = 2.7 K in CePdAl can be suppressed to zero at a nickel concentration of 14 %, where an antiferromagnetic quantum critical point is reached. Due to the combination of magnetic frustration and quantum criticality CePd{sub 1-x}Ni{sub x}Al may be a model system for investigating the influence of frustration on quantum critical behavior. To study the evolution of magnetic order in the substitution series detailed heat capacity measurements under magnetic fields were performed. The resulting phase diagrams for magnetic fields applied along the easy axis will be shown and discussed for CePdAl, the 5 %- and 10 %-nickel substituted system. A suppression of the Neel temperature as well as of the critical magnetic field are observed. In contrast to CePdAl no additional antiferromagnetic phases were detected in the Ni-alloyed systems. Furthermore, magnetic phase diagrams for fields applied along the hard ab-plane were established. Due to the frustration a slight increase of the ordering temperature was observed for small magnetic fields B<1 T.

  12. Preparation and characterization of Ce-doped ZnO nanofibers by an electrospinning method

    Directory of Open Access Journals (Sweden)

    Jong-Pil Kim


    Full Text Available ZnO and Ce-doped ZnO Nanofibers on (111 Pt/SiO2/Si substrates were produced using an electrospinning technique. The as-prepared composite fibres were subjected to high-temperature calcination to produce inorganic fibers. After calcining at a temperature of 500 °C, the average diameter of the ZnO and Ce-doped ZnO nanofibers were determined to be 170 nm and 225 nm, respectively. The average grain size of the ZnO and Ce-doped ZnO nanofibers were about 50 nm and 57 nm, respectively. The microstructure, chemical bonding state and photoluminescence of the produced ZnO and Ce-doped ZnO nanofibers were investigated. The Ce-doped ZnO nanofiber can be assigned to the presence of Ce ions on substitutional sites of Zn ions and the Ce3+ state from X-ray photoelectron spectra. Compared with PL spectra of ZnO nanofibers, the peak position of the UV emission of the Ce-doped ZnO nanofibers is sharply suppressed while the green emission band is highly enhanced.

  13. Electron spin-resonance study on Ce{sup 3+} in BaLiF{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Yamaga, M. [Department of Electrical and Electronic Engineering, Faculty of Engineering, Gifu University, Gifu (Japan); Honda, M. [Faculty of Science, Naruto University of Education, Naruto (Japan); Shimamura, K.; Fukuda, T. [Institute for Materials Research, Tohoku University, Sendai (Japan); Yosida, T. [Nakanihon Automotive College, Kamo (Japan)


    Three distinct Ce{sup 3+} sites in BaLiF{sub 3} crystals estimated from the optical spectra are associated with configurations of Ce{sup 3+} accompanied by different charge compensators. This assignment is consistent with the electron spin-resonance (ESR) result that there are two tetragonal Ce{sup 3+} centres distorted along the [001] axis and two orthorhombic Ce{sup 3+} centres distorted along the [110] axis in the absence of the cubic centre. The configurations of the Ce{sup 3+} centres correspond to the substitution for Ba{sup 2+} ions along the [001] and [110] axes with Li{sup +} ions and the Ba{sup 2+}-ion vacancies along the [001] and [110] axes. The dominant component of the Ce{sup 3+} luminescence spectrum with the peak at {approx}320 nm and the large Stokes shift energy ({approx}8300 cm{sup -1}) is assigned as due to the substitution for a Ba{sup 2+} ion along the [001] axis with a Li{sup +} ion. As the ionic radius (0.74 A) of Li{sup +} is much smaller than that (1.60 A) of Ba{sup 2+}, the Li substitution produces more space, resulting in the large lattice relaxation in the 5d excited state of Ce{sup 3+}. (author)

  14. Site symmetry and crystal field of Ce{sup 3+} luminescent centres in KMgF{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Yamaga, M. [Department of Electrical and Electronic Engineering, Faculty of Engineering, Gifu University, Gifu (Japan); Honda, M.; Kawamata, N. [Faculty of Science, Naruto University of Education, Naruto (Japan); Fujita, T.; Shimamura, K.; Fukuda, T. [Institute for Materials Research, Tohoku University, Sendai (Japan)


    The electron-spin resonance (ESR) spectra of Ce{sup 3+} in KMgF{sub 3} observed at low temperatures (<20 K) show that two tetragonal and two orthorhombic Ce{sup 3+} centres exist in the absence of a cubic centre. These Ce{sup 3+} centres are strongly associated with substitution of Ce{sup 3+} ions for K{sup +} ions with K{sup +}-ion vacancies at three different sites and for a Mg{sup 2+} ion with a vacancy of the nearest neighbour Mg{sup 2+} ion along the [101] direction as charge compensators. The optical absorption spectrum of Ce{sup 3+} in KMgF{sub 3} measured at room temperature consists of two intense broadbands with peaks at 229 and 237 nm, and two weak bands with peaks at 203 and 211 nm corresponding to the transition from the ground state {sup 2}F{sub 5/2} to the 5d{sup 1} excited states of Ce{sup 3+}. The Ce{sup 3+} luminescence spectrum excited at 229 or 237 nm at room temperature is composed of broadbands with double peaks at 265 and 282 nm, which are due to the ground-state splitting between {sup 2}F{sub 5/2} and {sup 2}F{sub 7/2}. The peak of the weak luminescence band excited at a tail (250-280 nm) of the intense absorption bands is shifted to lower energy. The intense and weak Ce{sup 3+} luminescence bands are assigned to Ce{sup 3+} ions substituting for K{sup +} ions away from and near to K{sup +}-ion vacancies, respectively. The luminescence from Ce{sup 3+} ions substituting for Mg{sup 2+} ions could not be observed at room temperature. (author)

  15. Properties of polyamorphous Ce75Al25 metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Q.-S.; Struzhkin, Viktor V.; Fang, Y. Z.; Gao, C. X.; Luo, H. B.; Wang, X. D.; Lathe, C.; Mao, Wendy L.; Wu, F. M.; Mao, Ho-kwang; Jiang, J. Z.


    The thermal stability and electronic transport properties of polyamorphous Ce{sub 75} Al{sub 25} metallic glass (MG) have been investigated using in situ high-pressure, high-temperature, energy-dispersive synchrotron x-ray diffraction and in situ high-pressure and low-temperature, four-probe resistance measurements. The results are compared with the properties of La{sub 75} Al{sub 25} MG. The pressure dependence of the crystallization temperature and resistance of the Ce{sub 75} Al{sub 25} MG exhibited turning points at the polyamorphic transition pressure, 1.5 GPa, and they clearly presented different behaviors below and above 1.5 GPa. In contrast, no turning points were observed in the La{sub 75} Al{sub 25} MG (La has no 4f electron). Additionally, the pressure-tuned temperature coefficient of resistance of the Ce{sub 75} Al{sub 25} MG was observed. These results revealed switchable properties in the polyamorphous Ce{sub 75} Al{sub 25} MG that are linked with 4f electron delocalization.

  16. Medicineringsfejl ved generisk substitution

    DEFF Research Database (Denmark)

    Rölfing, Jan


    Generic substitution is a major cause of medical mistakes in the general population. Danish legislation obligates pharmacies to substitute prescribed medicine with the cheapest equivalent formulation, despite variations in product name, packaging, shape and colour. Consequently, medical mistakes...... occur. Scientific evidence on the consequences of generic substitution is sparse. Call upon fellow health workers to report medical mistakes to the national entities and scientific peers, in order to increase awareness and scientific evidence about the problem....

  17. Conductivity Probe (United States)


    The Thermal and Electrical Conductivity Probe (TECP) for NASA's Phoenix Mars Lander took measurements in Martian soil and in the air. The needles on the end of the instrument were inserted into the Martian soil, allowing TECP to measure the propagation of both thermal and electrical energy. TECP also measured the humidity in the surrounding air. The needles on the probe are 15 millimeters (0.6 inch) long. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  18. Pollution Probe. (United States)

    Chant, Donald A.

    This book is written as a statement of concern about pollution by members of Pollution Probe, a citizens' anti-pollution group in Canada. Its purpose is to create public awareness and pressure for the eventual solution to pollution problems. The need for effective government policies to control the population explosion, conserve natural resources,…

  19. Mobile probes

    DEFF Research Database (Denmark)

    Ørngreen, Rikke; Jørgensen, Anna Neustrup; Noesgaard, Signe Schack


    to in an interview. This method provided valuable insight into the contextual use, i.e. how did the online resource transfer to the work practice. However, the research team also found that mobile probes may provide the scaffolding necessary for individual and peer learning at a very local (intra-school) community...

  20. Photoemission spectroscopy of Ce-filled skutterudites

    Energy Technology Data Exchange (ETDEWEB)

    Matsunami, M. [RIKEN/SPring-8, Hyogo 679 5148 (Japan)]. E-mail:; Horiba, K. [RIKEN/SPring-8, Hyogo 679 5148 (Japan); Taguchi, M. [RIKEN/SPring-8, Hyogo 679 5148 (Japan); Yamamoto, K. [RIKEN/SPring-8, Hyogo 679 5148 (Japan); Chainani, A. [RIKEN/SPring-8, Hyogo 679 5148 (Japan); Takata, Y. [RIKEN/SPring-8, Hyogo 679 5148 (Japan); Senba, Y. [JASRI/SPring-8, Hyogo 679 5148 (Japan); Ohashi, H. [JASRI/SPring-8, Hyogo 679 5148 (Japan); Sugawara, H. [Faculty of Integrated Arts and Sciences, University of Tokushima, Tokushima 770 8502 (Japan); Sato, H. [Department of Physics, Tokyo Metropolitan University, Tokyo 192 0397 (Japan); Harima, H. [Department of Physics, Kobe University, Kobe 657 8501 (Japan); Shin, S. [RIKEN/SPring-8, Hyogo 679 5148 (Japan); Institute of Solid State Physics, University of Tokyo, Kashiwa, Chiba 277 85817 (Japan)


    We have investigated the electronic structure of filled skutterudites CeFe{sub 4}P{sub 12} and CeOs{sub 4}Sb{sub 12} by means of Ce 3d-4f resonant photoemission spectroscopy. The difference in the spectral property of on-resonant photoemission spectra can be explained by the degree of hybridization between conduction band states and Ce 4f states. In addition, the spectral intensity at the Fermi level for CeFe{sub 4}P{sub 12} is significantly lower than that for CeOs{sub 4}Sb{sub 12}. The results indicate that a Kondo resonance exists in CeOs{sub 4}Sb{sub 12} while Kondo resonance is suppressed in CeFe{sub 4}P{sub 12}.

  1. Sustainability and substitutability. (United States)

    Fenichel, Eli P; Zhao, Jinhua


    Developing a quantitative science of sustainability requires bridging mathematical concepts from fields contributing to sustainability science. The concept of substitutability is central to sustainability but is defined differently by different fields. Specifically, economics tends to define substitutability as a marginal concept while fields such as ecology tend to focus on limiting behaviors. We explain how to reconcile these different views. We develop a model where investments can be made in knowledge to increase the elasticity of substitution. We explore the set of sustainable and optimal trajectories for natural capital extraction and built and knowledge capital accumulation. Investments in substitutability through knowledge stock accumulation affect the value of natural capital. Results suggest that investing in the knowledge stock, which can enhance substitutability, is critical to desirable sustainable outcomes. This result is robust even when natural capital is not managed optimally. This leads us to conclude that investments in the knowledge stock are of first order importance for sustainability.

  2. High-pressure high-temperature decomposition of CeCoGa to the Laves phases CeCo{sub 0.58}Ga{sub 1.42}, CeCo{sub 0.72}Ga{sub 1.28}, and CeCo{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Niehaus, Oliver; Rodewald, Ute C.; Heying, Birgit; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Heymann, Gunter; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie


    The monoclinic intermediate-valent gallide CeCoGa decomposes under high-pressure (HP) (9.5 GPa) high-temperature (HT) (1470 K) conditions into the Laves phases CeCo{sub 0.58}Ga{sub 1.42} (MgCu{sub 2} type), CeCo{sub 0.72}Ga{sub 1.28} (MgZn{sub 2} type; major product phase), and CeCo{sub 2} (MgCu{sub 2} type). The structures of the ternary Laves phases were refined from single crystal X-ray diffractometer data: Fd anti 3m, a=778.3(1) pm, wR2=0.0310, 63 F{sup 2} values, five variables for CeCo{sub 0.58(3)}Ga{sub 1.42(3)} and P6{sub 3}/mmc, a=547.24(5), c=858.76(7) pm, wR2=0.1009, 195 F{sup 2} values, 13 variables for CeCo{sub 0.72(1)}Ga{sub 1.28(1)}. Partial substitution of cobalt by gallium leads to a significant increase of the distances within the tetrahedral network: 253 pm Co-Co in CeCo{sub 2} as compared to 275 pm in CeCo{sub 0.58(3)}Ga{sub 1.42(3)} and 265-277 pm in CeCo{sub 0.72(1)}Ga{sub 1.28(1)}. The crystal chemical consequences are briefly discussed.

  3. n'-(substituted phenyl)

    African Journals Online (AJOL)

    Preferred Customer

    cyano-3-methyl thioacrylyl)-N'-(substituted phenyl)urea (5). Benzylamine attacked double bond to form a transition state in which the orientation of benzylamino and ester carbonyl is cis because of the formation of an intramolecular hydrogen.

  4. Synthesis of substituted pyrazines (United States)

    Pagoria, Philip F.; Zhang, Mao Xi


    A method for synthesizing a pyrazine-containing material according to one embodiment includes contacting an iminodiacetonitrile derivative with a base and a reagent selected from a group consisting of hydroxylamine, a hydroxylamine salt, an aliphatic primary amine, a secondary amine, an aryl-substituted alkylamine a heteroaryl-substituted alkyl amine, an alcohol, an alkanolamine and an aryl alcoholamine. Additional methods and several reaction products are presented. ##STR00001##

  5. Synthesis and characterization of Ce and La modified bismuth titanate

    Directory of Open Access Journals (Sweden)

    Nikolina Pavlović


    Full Text Available Bismuth titanate based nanopowders with the different content of La or Ce were synthesized by the modified sol-gel method. After calcination at 600°C, in addition to Aurivillius layered structure, a small quantity of cubic pyrochlore phase was detected in the La modified powders, while this second phase was much more pronounced in the Ce substituted powders. In fact, as the powder with the highest amount of Ce (Bi3CeTi3O12 has the pure pyrochlore phase it seems that the presence of Ce stabilizes the formation of this phase. This different infl uence of cerium and lanthanum could be explained by the incorporation of their ions on the different sites in the titanate structure. Bismuth titanate based ceramics, sintered at 1050°C/2h, had densities above 93% of theoretical density and characteristic plate-like grain morphology. Small quantity of cubic pyrochlore phase was detected only in the Ce modifi ed bismuth titanate ceramics. On the other hand, lanthanum addition caused formation of smaller grain size with pronounced plate-like morphology.

  6. Luminescence properties and electronic structure of Ce{sup 3+}-doped gadolinium aluminum garnet

    Energy Technology Data Exchange (ETDEWEB)

    Dotsenko, V.P., E-mail: [A.V. Bogatsky Physico-Chemical Institute, National Academy of Sciences of Ukraine, 86 Lustdorfskaya doroga, 65080 Odessa (Ukraine); Berezovskaya, I.V. [A.V. Bogatsky Physico-Chemical Institute, National Academy of Sciences of Ukraine, 86 Lustdorfskaya doroga, 65080 Odessa (Ukraine); Voloshinovskii, A.S. [Ivan Franko National University of Lviv, 8 Kirilo i Mefodii, 79005 Lviv (Ukraine); Zadneprovski, B.I. [Central Research and Development Institute of Chemistry and Mechanics, 115487 Moscow (Russian Federation); Efryushina, N.P. [A.V. Bogatsky Physico-Chemical Institute, National Academy of Sciences of Ukraine, 86 Lustdorfskaya doroga, 65080 Odessa (Ukraine)


    Highlights: • The luminescence properties of Ce{sup 3+} ions in (Y, Gd){sub 3}Al{sub 5}O{sub 12} are analyzed. • The Gd{sup 3+} → Y{sup 3+} substitution leads to increasing of Ce{sup 3+} noncubic crystal field splitting parameter. • The excitation spectra for the Ce{sup 3+} emission in GdAG contain bands at 6.67, 7.75, and 9.76 eV. • These features are due to the Ce{sup 3+}-bound exciton formation and O 2p → Al 3s, 3p transitions. • Contributions from Al atoms to the conduction-band density of states are quite essential. - Abstract: Yttrium-gadolinium aluminum garnets (YGdAG) doped with Ce{sup 3+} ions have been prepared by co-precipitation method. The luminescent properties of Ce{sup 3+} ions in Gd{sub 3(1−x)}Ce{sub 3x}Al{sub 5}O{sub 12} (x = 0.01) have been studied upon excitation in the 2–20 eV region. The substitution of Gd{sup 3+} for Y{sup 3+} in the garnet structure results in broadening the emission band and shifting its maximum towards the longer wavelengths. It was found that in addition to the 4f → 5d excitation bands of Ce{sup 3+} ions, the excitation spectra for the Ce{sup 3+} emission contain bands at 6.67, 7.75, and 9.76 eV. These bands are attributed to the Ce{sup 3+}-bound exciton formation and O 2p → Al 3s, 3p transitions, respectively. Although gadolinium states dominate near the bottom of the conduction band of Gd{sub 3}Al{sub 5}O{sub 12}, contributions from Al{sub tetr} and Al{sub oct} atoms to the conduction-band density of states are evaluated as quite essential.

  7. EPR study of concentration dependence in Ce, Ce : La and Ce:Y doped SrF2

    NARCIS (Netherlands)

    Dankert, O.; Vainchtein, David; Datema, H.C.; den Hartog, Hendrik


    Experimental results of an EPR-study of the concentration dependence of the doubly integrated intensity and linewidth of the signals associated with tetragonal Ce3+-F--dipoles in Sr1-xCexF2+x, Sr-1-0.005-x Ce0.005LaxF2+0.005+x and Sr-1-0.005-x Ce0.005YxF2+0.005+x are presented. Both show a nonlinear

  8. Optical properties of pure and Ce{sup 3+} doped gadolinium gallium garnet crystals and epitaxial layers

    Energy Technology Data Exchange (ETDEWEB)

    Syvorotka, I.I. [Scientific Research Company “Carat”, 202 Stryjska Street, Lviv 79031 (Ukraine); Sugak, D. [Scientific Research Company “Carat”, 202 Stryjska Street, Lviv 79031 (Ukraine); Lviv Polytechnic National University, 12, S. Bandera Street, Lviv, 79013 (Ukraine); Wierzbicka, A. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Wittlin, A. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Cardinal Stefan Wyszyński University in Warsaw, ul. Dewajtis 5, 01-815 Warsaw (Poland); Przybylińska, H. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Barzowska, J. [Institute of Experimental Physics, Gdańsk University, ul. Wita Stwosza 57, Gdańsk (Poland); Barcz, A. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Institute of Electron Technology, Al. Lotników 32/46, 02-668 Warsaw (Poland); Berkowski, M.; Domagała, J. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Mahlik, S.; Grinberg, M. [Institute of Experimental Physics, Gdańsk University, ul. Wita Stwosza 57, Gdańsk (Poland); Ma, Chong-Geng [College of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China); and others


    Results of X-ray diffraction and low temperature optical absorption measurements of cerium doped gadolinium gallium garnet single crystals and epitaxial layers are reported. In the region of intra-configurational 4f–4f transitions the spectra of the bulk crystals exhibit the signatures of several different Ce{sup 3+} related centers. Apart from the dominant center, associated with Ce substituting gadolinium, at least three other centers are found, some of them attributed to the so-called antisite locations of rare-earth ions in the garnet host, i.e., in the Ga positions. X-ray diffraction data prove lattice expansion of bulk GGG crystals due to the presence of rare-earth antisites. The concentration of the additional Ce-related centers in epitaxial layers is much lower than in the bulk crystals. However, the Ce-doped layers incorporate a large amount of Pb from flux, which is the most probable source of nonradiative quenching of Ce luminescence, not observed in crystals grown by the Czochralski method. - Highlights: • Ce{sup 3+} multicenters found in Gadolinium Gallium Garnet crystals and epitaxial layers. • High quality epitaxial layers of pure and Ce-doped GGG were grown. • Luminescence quenching of Ce{sup 3+} by Pb ions from flux detected in GGG epitaxial layers. • X-ray diffraction allows measuring the amount of the rare-earth antisites in GGG.

  9. Synthesis, characterization of N-, S-, O-substituted naphtho- and ...

    Indian Academy of Sciences (India)

    MS received 2 May 2011; revised 22 November 2011; accepted 13 December 2011. Abstract. The new series of N-, S-, O-substituted 1 .... LC/MS/MS spectrometer according to ESI probe. Pro- ducts were isolated by column ...... the fluorescence characteristic of the coumarin ring sub- stituted naphthoquinone assigned to the ...

  10. Comparison of fungal carbohydrate esterases of family CE16 on artificial and natural substrates


    Puchart, Vladimir; Agger, Jane W.; Berrin, Jean-Guy; Varnai, Aniko; Westereng, Bjorge; Biely, Peter


    The enzymatic conversion of acetylated hardwood glucuronoxylan to functional food oligomers, biochemicals or fermentable monomers requires besides glycoside hydrolases enzymes liberating acetic acid esterifying position 2 and/or 3 in xylopyranosyl (Xylp) residues. The 3-0-acetyl group at internal Xylp residues substituted by MeGlcA is the only acetyl group of hardwood acetylglucuronoxylan and its fragments not attacked by acetylxylan esterases of carbohydrate esterase (CE) families 1, 4, 5 an...

  11. Bone substitute biomaterials

    CERN Document Server

    Mallick, K


    Bone substitute biomaterials are fundamental to the biomedical sector, and have recently benefitted from extensive research and technological advances aimed at minimizing failure rates and reducing the need for further surgery. This book reviews these developments, with a particular focus on the desirable properties for bone substitute materials and their potential to encourage bone repair and regeneration. Part I covers the principles of bone substitute biomaterials for medical applications. One chapter reviews the quantification of bone mechanics at the whole-bone, micro-scale, and non-scale levels, while others discuss biomineralization, osteoductivization, materials to fill bone defects, and bioresorbable materials. Part II focuses on biomaterials as scaffolds and implants, including multi-functional scaffolds, bioceramics, and titanium-based foams. Finally, Part III reviews further materials with the potential to encourage bone repair and regeneration, including cartilage grafts, chitosan, inorganic poly...

  12. [Delegation yes, substitution no!]. (United States)

    Schroeder, A


    The aging of society leads on the one hand to increasing case numbers and on the other hand to a reduction in the number of physicians available for patient treatment. The delegation and substitution of medical duties as a tried and tested method is increasingly being recommended in order to compensate for the lack of physicians. The Berufsverband der Deutschen Urologen (BDU, Professional Association of German Urologists) supports the guiding principle of the Bundesärztekammer (Federal Medical Council) of "delegation yes, substitution no" and rejects a substitution of medical duties by non-medical academic health personnel. Against the background of the demographic changes, the increasing need for treatment and the current deficiency of junior physicians, a more extensive inclusion of well-qualified and experienced non-medical personnel by the delegation of medically responsible duties (medical scope of practice) can be an appropriate measure to maintain a good medical service in practices, hospitals and nursing homes.

  13. Electrophilic phenoxy-substituted phosphonium cations. (United States)

    LaFortune, James H W; Johnstone, Timothy C; Pérez, Manuel; Winkelhaus, Daniel; Podgorny, Vitali; Stephan, Douglas W


    A family of electrophilic phenoxy-substituted phosphonium salts [(RO)P(C6F5)3][B(C6F5)4] (R = C6H5, 4-FC6H4, 2,4-F2C6H3, C6F5) have been synthesized and their air stability was evaluated. Computations of the fluoride ion affinity and global electrophilicity index have been used to compare the electrophilicity of these phosphonium salts. The Lewis acidity of these phosphonium salts was probed computationally and experimentally in a Friedel-Crafts-type dimerization, hydrodefluorination, hydrosilylation, hydrodeoxygenation, and dehydrocoupling reactions.

  14. Direct observation of multivalent states and 4 f →3 d charge transfer in Ce-doped yttrium iron garnet thin films (United States)

    Vasili, H. B.; Casals, B.; Cichelero, R.; Macià, F.; Geshev, J.; Gargiani, P.; Valvidares, M.; Herrero-Martin, J.; Pellegrin, E.; Fontcuberta, J.; Herranz, G.


    Due to their large magneto-optic responses, rare-earth-doped yttrium iron garnets, Y3F e5O12 (YIG), are highly regarded for their potential in photonics and magnonics. Here, we consider the case of Ce-doped YIG (Ce-YIG) thin films, in which substitutional C e3 + ions are magnetic because of their 4 f1 ground state. In order to elucidate the impact of Ce substitution on the magnetization of YIG, we have carried out soft x-ray spectroscopy measurements on Ce-YIG films. In particular, we have used the element specificity of x-ray magnetic circular dichroism to extract the individual magnetization curves linked to Ce and Fe ions. Our results show that Ce doping triggers a selective charge transfer from Ce to the Fe tetrahedral sites in the YIG structure. This, in turn, causes a disruption of the electronic and magnetic properties of the parent compound, reducing the exchange coupling between the Ce and Fe magnetic moments and causing atypical magnetic behavior. Our work is relevant for understanding magnetism in rare-earth-doped YIG and, eventually, may enable a quantitative evaluation of the magneto-optical properties of rare-earth incorporation into YIG.

  15. Para, ferro and antiferromagnetic properties of MnO2 and Ce1- x Mn x O2 nanoparticles (United States)

    Bayyappagari, Balaraju; Shaik, Kaleemulla


    Manganese-substituted cerium oxide nanoparticles (Ce1- x Mn x O2) at x = 0.00, 0.03 and 0.05 were prepared using ball milling technique and the milled powder samples were subjected to different characterization techniques such as X-ray diffractometer (XRD), scanning electron microscope with energy dispersive analysis of X-rays and vibrating sample magnetometer to study the structural, morphology and magnetic properties, respectively. From XRD, it was confirmed that the prepared samples were in Cubic structure at all Mn-doping concentrations and no evidence of impurities were found. The crystallite sizes of the powders were in the range of 30-44 nm and it decreased with increase of Mn substitution. The SEM images reflected that the grains are uniform in size and are in spherical shape. From magnetic studies, it was found that the bulk MnO2 was paramagnetic in nature, whereas the CeO2 nanoparticles were soft ferromagnetic at room temperature. The pure CeO2 nanoparticles exhibited a magnetization of 4.79 memu/g, coercivity of 389 Oe, and retentivity of 2.08 memu/g. A drastic change in magnetic behaviour of CeO2 nanoparticles was found by the substitution of Mn into the CeO2 host lattice. The Ce1- x Mn x O2 nanoparticles exhibited soft ferromagnetism at low field and antiferromagnetism at high applied magnetic fields. No magnetic saturation was found in Ce1- x Mn x O2 nanoparticles even when the magnetic field is increased to 15 kOe.

  16. Performing Substitute Teaching (United States)

    Bletzer, Keith V.


    Formal education is both a right and an obligation bestowed on young people in most all nations of the world. Teachers (adults) and students (youth) form a co-present dyadic contract that must be maintained within the classroom. Substitute teachers fill a role in sustaining the integrity of this teacher-student link, whenever teachers are absent.…

  17. n'-(substituted phenyl)

    African Journals Online (AJOL)

    Preferred Customer

    5h),. 4-F (5i), 2, 4-F (5j), 4-F-3-Cl (5k). Scheme 1. Schematic representation of the preparation of N-(3-benzylamino-2-cyano-3-methyl thioacrylyl)-N'-(substituted phenyl)urea (5). Benzylamine attacked double bond to form a transition state in ...

  18. Crystal growth and characterization of CeFe{sub 1-x}Ru{sub x} PO

    Energy Technology Data Exchange (ETDEWEB)

    Balle, Tanita; Kliemt, Kristin; Krellner, Cornelius [Goethe Universitaet Frankfurt, Kristall- und Materiallabor (Germany)


    CeRuPO is a one of the few heavy fermion systems, which order ferromagnetically at low temperatures (T{sub C} = 15 K), because of dominant RKKY-interaction. CeFePO on the other hand shows no long-range magnetic order even at low temperatures because of dominant Kondo effect (T{sub K} = 10 K). By substituting CeFePO with ruthenium we can reach a quantum critical point, at which the RKKY-interaction and the Kondo effect are equally strong. To study the quantum critical point, and to enlighten the question if the order stays ferromagnetically down to lowest temperatures, high quality crystals are needed. Here, the growth and characterization of the single crystals will be discussed. We obtained mm-sized single crystals of the unsubstituted CeRuPO and CeFePO by a modified Bridgeman method using tin as a flux. The quality of the crystals was verified by Powder-X-Ray-Diffraction, energy dispersive X-ray spectroscopy and Laue backscattering.

  19. Interaction of the components in the Ce-Cu-Zn ternary system at 200deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Pavlyuk, V. [Ivan Franko National University of Lviv, Department of Inorganic Chemistry, Kyryl and Mefodiy str. 6, 79005 Lviv (Ukraine); Jan Dlugosz University of Czestochowa, Institute of Chemistry and Environmental Protection, al. Armii Krajowej 13/15, 42200 Czestochowa (Poland); Prochwicz, W. [Jan Dlugosz University of Czestochowa, Institute of Chemistry and Environmental Protection, al. Armii Krajowej 13/15, 42200 Czestochowa (Poland); Solokha, P. [Ivan Franko National University of Lviv, Department of Inorganic Chemistry, Kyryl and Mefodiy str. 6, 79005 Lviv (Ukraine)]. E-mail:; Zelinska, O. [Ivan Franko National University of Lviv, Department of Inorganic Chemistry, Kyryl and Mefodiy str. 6, 79005 Lviv (Ukraine); Marciniak, B. [Jan Dlugosz University of Czestochowa, Institute of Chemistry and Environmental Protection, al. Armii Krajowej 13/15, 42200 Czestochowa (Poland); Rozycka-Sokolowska, E. [Jan Dlugosz University of Czestochowa, Institute of Chemistry and Environmental Protection, al. Armii Krajowej 13/15, 42200 Czestochowa (Poland)


    The isothermal section of the Ce-Cu-Zn phase diagram was constructed at 200 deg. C over the whole concentration range as a result of X-ray powder diffraction, wavelength dispersive spectrometry and electron probe microanalysis. The existence of one new ternary compound Ce{sub 2}Cu{sub 5-5.7}Zn{sub 2-1.3} was observed at this temperature and its crystal structure was refined from X-ray single crystal data (structure type Ce{sub 2}Ni{sub 5}Zn{sub 2}, space group R3-bar m, Pearson code hR18, a=0.4998(1)-0.5078(1)nm, c=3.6924(5)-3.6987(4)nm). The homogeneity regions were determined for a number of solid solutions on the basis of binary phases.

  20. Performance of cubic ZrO{sub 2} doped CeO{sub 2}: First-principles investigation on elastic, electronic and optical properties of Ce{sub 1−x} Zr{sub x}O{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Dong [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, Yunnan (China); Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan (China); Zeng, Chunhua, E-mail: [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, Yunnan (China); Faculty of Science, Kunming University of Science and Technology, Kunming 650093, Yunnan (China); Wang, Hua, E-mail: [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, Yunnan (China); Luo, Hongchun [Faculty of Science, Kunming University of Science and Technology, Kunming 650093, Yunnan (China); Cheng, Xianming [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, Yunnan (China); Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan (China); Xiang, Chao [College of Mechanical and Electrical Engineering, Yangtze Normal University, Fuling 408100, Chongqing (China); Wei, Yonggang; Li, Kongzhai; Zhu, Xing [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, Yunnan (China); Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan (China)


    The structural, elastic, electronic and optical properties of Ce{sub 1−x} Zr{sub x}O{sub 2} (x = 0, 0.25, 0.5, 0.75, 1) fluorite type oxides are studied by researchers using the method of density functional theory (DFT) + U method. The calculated equilibrium lattice parameter, cell volume, elastic and optical properties for CeO{sub 2} and ZrO{sub 2} are all in good agreement with the available experimental data and other theoretical results. It is found that Ce substituted by Zr leads to the formation of the pseudo-cubic fluorite-type structure. With doping concentration × increasing, the lattice parameter, cell volume and the bond length of d{sub Ce−O} and d{sub Zr−O} decrease linearly. It is interesting to find that the hardness of materials increase with Zr concentration increasing. For Ce{sub 0.75} Zr{sub 0.25} O{sub 2}, we also find that its ductility is good. Meanwhile, the range of the conduction band energy in the doped system becomes wider than that in the undoped system. The overlapping band phenomenon occur for all substitutions in Ce{sub 1−x} Zr{sub x}O{sub 2} (from x = 0.25 to x = 0.75), especially for the structure of Ce{sub 0.5} Zr{sub 0.5} O{sub 2} and Ce{sub 0.25} Zr{sub 0.75} O{sub 2}, its second band gaps almost disappear. Based on the dielectric functions obtained, it is shown that the static dielectric constant ε{sub 0} and refractive index n{sub 0} obviously decrease with Zr concentration increasing. After discussing, we know that CeO{sub 2} is suitable as a useful high-refractive index film material in single and multilayered optical coatings, whereas ZrO{sub 2} can be used as gate-dielectric materials in metal-oxide semiconductor (MOS) devices, in metallurgy and as a thermal barrier coating in engines. - Highlights: • Structural, and optical properties of fluorite type oxides are studied; • Ce substituted by Zr leads to formation of pseudo-cubic fluorite-type structure; • Hardness of materials are increased with Zr

  1. Proximal Probes Facility (United States)

    Federal Laboratory Consortium — The Proximal Probes Facility consists of laboratories for microscopy, spectroscopy, and probing of nanostructured materials and their functional properties. At the...

  2. Nonstoichiometry and stability in water of undoped SrCeO3

    Directory of Open Access Journals (Sweden)

    Jurado, J. R.


    Full Text Available Strontium cerate is the parent phase of an important class of proton-conducting perovskites with various potential technological applications. Phase formation and structure of SrCeO3 with Sr:Ce nonstoichiometry have been investigated for the series, Sr1±xCeO3±δ (0.98 ≤ x ≤ 1.04. Analyses by EPMA (electron probe micro analysis and X-ray diffraction (XRD indicate that, for samples sintered at 1350°C, the main phase is Sr-rich for all x. The accommodation of excess SrO in the bulk phase and/or intergranular regions is discussed. The stability of nominally stoichiometric SrCeO3 was examined in an atmosphere of high water vapour partial pressure (pH2O for 2 hours, degrading to Sr(OH2.H2O and CeO2 for pH2O ≥ 3.6atm.La fase SrCeO3 da origen a una importante familia de perovskitas conductoras protónicas con potenciales aplicaciones tecnológicas. En este trabajo se estudia la formación de la fase y la estructura de SrCeO3 con la relación Sr:Ce no estequiométrica para la serie Sr1±xCeO3±δ (0.98 ≤ x ≤ 1.04. Los análisis por microsonda (EPMA y difracción de rayos X (DRX indican que en las muestras sinterizadas a 1350°C, la fase principal es rica en estroncio para todo valor de x. Se discute la posible ubicación del exceso de SrO tanto en la región intergranular como en el propio grano. También se examina la estabilidad de la composición con estequiometría nominal SrCeO3 en una atmosfera con una alta presión de vapor de agua (pH2O, observándose que la degradación a Sr(OH2.H2O y CeO2 ocurre a pH2O ≥ 3.6atm (expuesto durante 2 horas.

  3. Ce and Eu anomalies in zircon as proxies for the oxidation state of magmas (United States)

    Trail, Dustin; Bruce Watson, E.; Tailby, Nicholas D.


    Chondrite normalized rare earth element (REE) patterns of zircons generally have enriched Ce values relative to La and Pr, and depleted Eu values relative to Sm and Gd. High Ce contents in zircon may imply oxidizing conditions (Ce4+ is more compatible than Ce3+), whereas depleted Eu contents may imply reducing conditions (Eu2+ does not substitute into the zircon lattice). We report 41 experiments in which temperature, melt composition, and oxygen fugacity (fO2) were varied in order to explore the details of Ce and Eu incorporation into zircon. Crystals were synthesized in hydrous silicate melts at 10 kbar and 800-1300 °C. Synthetic rock mixes were doped with La + Ce + Pr (±P) or Sm + Eu + Gd and buffered at oxygen fugacities ranging from ∼IW (iron-wüstite) to >MH (magnetite-hematite); the run products were analyzed by electron microprobe to obtain crystal/melt partition coefficients. Cerium anomalies increase with higher oxygen fugacities and lower crystallization temperatures. In agreement with other experimental studies, peralkaline melts yield the largest zircon grains but show only modest Ce anomalies even at fO2s > MH. The same reason that zircons grown in peralkaline melts are easy to synthesize in the laboratory (these melts are capable of dissolving wt.% levels of Zr before zircon saturation due to high alkali content) makes the melt structure/composition atypical and not representative of most natural magmas. With this in mind, we synthesized zircons in a granitic melt with more modest alkali contents that require geologically plausible Zr contents for saturation. We obtained the following empirical relationship: ln Ce/CeD=(0.1156±0.0050)×ln(fO2)+13,860±708T/(K)-6.125±0.484 where (Ce/Ce∗)D is the Ce anomaly in zircon calculated from partition coefficients, and T is the zircon crystallization temperature in K. Europium anomalies from the same melt composition are more negative at lower oxygen fugacities, but with no resolvable temperature

  4. Cost objective PLM and CE

    CERN Document Server

    Perry, Nicolas


    Concurrent engineering taking into account product life-cycle factors seems to be one of the industrial challenges of the next years. Cost estimation and management are two main strategic tasks that imply the possibility of managing costs at the earliest stages of product development. This is why it is indispensable to let people from economics and from industrial engineering collaborates in order to find the best solution for enterprise progress for economical factors mastering. The objective of this paper is to present who we try to adapt costing methods in a PLM and CE point of view to the new industrial context and configuration in order to give pertinent decision aid for product and process choices. A very important factor is related to cost management problems when developing new products. A case study is introduced that presents how product development actors have referenced elements to product life-cycle costs and impacts, how they have an idea bout economical indicators when taking decisions during t...

  5. Antiferromagnetism in Ce1-xLaxAl2Ga2 and Ce1-yYyAl2Ga2 Kondo-lattice systems (United States)

    Garde, C. S.; Ray, J.; Chandra, G.


    We report here resistivity ρ and thermoelectric-power S measurements between 1.7 and 300 K on Ce1-xLaxAl2Ga2 and Ce1-yYyAl2Ga2 Kondo-lattice alloys. By variation of x and y, there is a clear evolution of the Kondo-like resistivity minimum, which is not seen in the parent alloy (x=0). With both La and Y substitutions, the antiferromagnetic transition temperature TN is found to be depressed. It is suggested that this depression by a variation of x can be explained solely on the basis of the weakening of the intersite Ruderman-Kittel-Kasuya-Yosida interaction, whereas with a variation of y, the TN depression results from an interplay of both single-site and intersite effects.

  6. The electronic configuration of substitutional Fe in silicon

    CERN Document Server

    Weyer, G; Fanciulli, M; Fedosseev, V; Gunnlaugsson, H P; Mishin, V I; Sielemann, R


    Ion implantations of radioactive /sup 57/Mn/sup +/ into differently doped silicon single crystals held at 300-600 K have been utilized for /sup 57/Fe Mossbauer studies of interstitial and substitutional Fe. Site and charge state assignments have been made on the basis of the determined hyperfine interaction parameters and Debye temperatures. Substantial fractions of substitutional /sup 57/Mn probe atoms are proposed to occur due to annealing reactions. This site is maintained in the subsequent decay to /sup 57/Fe by

  7. Hydrodynamic ultrasonic probe (United States)

    Day, Robert A.; Conti, Armond E.


    An improved probe for in-service ultrasonic inspection of long lengths of a workpiece, such as small diameter tubing from the interior. The improved probe utilizes a conventional transducer or transducers configured to inspect the tubing for flaws and/or wall thickness variations. The probe utilizes a hydraulic technique, in place of the conventional mechanical guides or bushings, which allows the probe to move rectilinearly or rotationally while preventing cocking thereof in the tube and provides damping vibration of the probe. The probe thus has lower friction and higher inspection speed than presently known probes.

  8. Thermoelectric properties in Ce{sub 1-x}La{sub x}Fe{sub 4}P{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Sugawara, H. [Faculty of Integrated Arts and Sciences, University of Tokushima, Minamijosanjima-machi, Tokushima 770 8502 (Japan)]. E-mail:; Yuasa, S. [Department of Physics, Tokyo Metropolitan University, Minami-Ohsawa, Hachioji, Tokyo 192 0397 (Japan); Tsuchiya, A. [Department of Physics, Tokyo Metropolitan University, Minami-Ohsawa, Hachioji, Tokyo 192 0397 (Japan); Aoki, Y. [Department of Physics, Tokyo Metropolitan University, Minami-Ohsawa, Hachioji, Tokyo 192 0397 (Japan); Sato, H. [Department of Physics, Tokyo Metropolitan University, Minami-Ohsawa, Hachioji, Tokyo 192 0397 (Japan); Sasakawa, T. [Department of Quantume Matter, ADSM, Hiroshima University, Higashi-Hiroshima 739 8530 (Japan); Takabatake, T. [Department of Quantume Matter, ADSM, Hiroshima University, Higashi-Hiroshima 739 8530 (Japan)


    We have measured the electrical resistivity {rho}, thermoelectric power S, and thermal conductivity {kappa} in single-crystalline Ce{sub 1-x}La{sub x}Fe{sub 4}P{sub 12}. La-substitution by 1% destroys the energy gap, suggesting that the coherence among the Ce-ions plays an important role for the semiconducting behavior. Within the investigated concentration range, the maximum power factor S{sup 2}/{rho} is found to be 21{mu}Wcm{sup -1}K{sup -2} at room temperature.

  9. Polydopamine coated capillaries for CE separations


    Partyka, Jan


    We have tested CE separation of selected samples in capillaries with polydopamine modified surface. The capillaries were modified by polydopamine or polydopamine with an additive. The polydopamine coating with additive represents a simple and effective procedure for capillary alteration by another modificator such as hydroxyethyl cellulose, hydroxypropyl cellulose etc. In this work, we represent separation data from PrinCE system with UV detection for peptides, proteins and oligosaccha...

  10. Structural and magnetic properties of Ce/Fe and Ce/FeCoV multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Tixier, S.; Boeni, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Mannix, D.; Stirling, W.G. [Liverpool Univ. (United Kingdom); Lander, G.H.


    Ce/Fe and Ce/FeCoV multilayers have been grown by magnetron sputtering. The interfaces are well defined and the layers are crystalline down to an individual layer thickness of 20 A. Ce/FeCoV multilayers show sharper interfaces than Ce/Fe but some loss of crystallinity is observed. Hysteresis loops obtained by SQUID show different behaviour of the bulk magnetisation as a function of the layer thickness. Fe moments are found by Moessbauer spectroscopy to be perpendicular to the interfaces for multilayers with small periodicity. (author) 2 figs., 2 refs.

  11. [Development of a Fluorescence Probe for Live Cell Imaging]. (United States)

    Shibata, Aya


    Probes that detect specific biological materials are indispensable tools for deepening our understanding of various cellular phenomena. In live cell imaging, the probe must emit fluorescence only when a specific substance is detected. In this paper, we introduce a new probe we developed for live cell imaging. Glutathione S-transferase (GST) activity is higher in tumor cells than in normal cells and is involved in the development of resistance to various anticancer drugs. We previously reported the development of a general strategy for the synthesis of probes for detection of GST enzymes, including fluorogenic, bioluminogenic, and 19 F-NMR probes. Arylsulfonyl groups were used as caging groups during probe design. The fluorogenic probes were successfully used to quantitate very low levels of GST activity in cell extracts and were also successfully applied to the imaging of microsomal MGST1 activity in living cells. The bioluminogenic and 19 F-NMR probes were able to detect GST activity in Escherichia coli cells. Oligonucleotide-templated reactions are powerful tools for nucleic acid sensing. This strategy exploits the target strand as a template for two functionalized probes and provides a simple molecular mechanism for multiple turnover reactions. We developed a nucleophilic aromatic substitution reaction-triggered fluorescent probe. The probe completed its reaction within 30 s of initiation and amplified the fluorescence signal from 0.5 pM target oligonucleotide by 1500 fold under isothermal conditions. Additionally, we applied the oligonucleotide-templated reaction for molecular releasing and peptide detection.

  12. Van Allen Probes observations of unusually low frequency whistler mode waves observed in association with moderate magnetic storms: Statistical study


    Cattell, C. A.; Breneman, A. W.; Thaller, S. A.; Wygant, J. R.; Kletzing, C. A.; Kurth, W. S.


    Abstract We show the first evidence for locally excited chorus at frequencies below 0.1?f ce (electron cyclotron frequency) in the outer radiation belt. A statistical study of chorus during geomagnetic storms observed by the Van Allen Probes found that frequencies are often dramatically lower than expected. The frequency at peak power suddenly stops tracking the equatorial 0.5?f ce and f/f ce decreases rapidly, often to frequencies well below 0.1?f ce (in situ and mapped to equator). These ve...

  13. Site dependence of the Kondo scale in CePd{sub 1-x}Rh{sub x} evidenced by thermopower

    Energy Technology Data Exchange (ETDEWEB)

    Stockert, Ulrike; Hartmann, Stefanie; Deppe, Micha; Caroca-Canales, Nubia; Geibel, Christoph; Steglich, Frank [Max Planck Institute for Chemical Physics of Solids, Dresden (Germany); Sereni, Julian [Division Bajas Temperaturas, Centro Atomico Bariloche (Argentina)


    CePd{sub 1-x}Rh{sub x} undergoes a continuous evolution from ferromagnetic order in CePd to an intermediate-valence (IV) ground state for CeRh. Close to the disappearance of magnetic order at x{sub cr} ∼ 0.87 unusual behavior of the ac susceptibility and the specific heat was observed. It was explained with a broad distribution of local Kondo temperatures T{sub K} from below 2 K to above 50 K due to the disorder introduced by Pd-Rh exchange. The thermopower S is very sensitive to Kondo scattering even for diluted 4f systems. In Ce compounds a large positive maximum in S(T) is usually observed around T{sub K}. We studied S(T) in CePd{sub 1-x}Rh{sub x} in order to evaluate the presence of Kondo scattering and the involved energy scales. Pure CeRh shows typical IV behavior with a large maximum at 220 K and small values at low T. Already 5 % Pd substitution leads to a strong enhancement of the low-T thermopower. Even larger values are found around x{sub cr}, while the high-T maximum shifts only moderately. Our results are in line with the existence of low (local) Kondo scales in the presence of IV behavior at high Rh content x > x{sub cr}. For lower Rh content a decreasing (average) Kondo scale is found.

  14. Enhanced activity and stability of La-doped CeO2 monolithic catalysts for lean-oxygen methane combustion. (United States)

    Zhu, Wenjun; Jin, Jianhui; Chen, Xiao; Li, Chuang; Wang, Tonghua; Tsang, Chi-Wing; Liang, Changhai


    Effective utilization of coal bed methane is very significant for energy utilization and environment protection. Catalytic combustion of methane is a promising way to eliminate trace amounts of oxygen in the coal bed methane and the key to this technology is the development of high-efficiency catalysts. Herein, we report a series of Ce1-xLaxO2-δ (x = 0-0.8) monolithic catalysts for the catalytic combustion of methane, which are prepared by citric acid method. The structural characterization shows that the substitution of La enhance the oxygen vacancy concentration and reducibility of the supports and promote the migration of the surface oxygen, as a result improve the catalytic activity of CeO2. M-Ce0.8La0.2O2-δ (monolithic catalyst, Ce0.8La0.2O2-δ coated on cordierite honeycomb) exhibits outstanding activity for methane combustion, and the temperature for 10 and 90% methane conversion are 495 and 580 °C, respectively. Additionally, Ce0.8La0.2O2-δ monolithic catalyst presents excellent stability at high temperature. These Ce1-xLaxO2-δ monolithic materials with a small amount of La incorporation therefore show promises as highly efficient solid solution catalysts for lean-oxygen methane combustion. Graphical abstract ᅟ.

  15. Complex charge ordering in CeRuSn

    NARCIS (Netherlands)

    Feyerherm, R.; Dudzik, E.; Valencia, S.; Mydosh, J.A.; Huang, Y.K.; Hermes, W.; Pöttgen, R.


    At ambient temperatures, CeRuSn exhibits an extraordinary structure with a coexistence of two types of Ce ions in a metallic environment, namely trivalent Ce3+ and intermediate valent Ce(4−δ)+. Charge ordering produces a doubling of the unit cell along the c axis with respect to the basic monoclinic

  16. Mobile Game Probes

    DEFF Research Database (Denmark)

    Borup Lynggaard, Aviaja


    This paper will examine how probes can be useful for game designers in the preliminary phases of a design process. The work is based upon a case study concerning pervasive mobile phone games where Mobile Game Probes have emerged from the project. The new probes are aimed towards a specific target...... group and the goal is to specify the probes so they will cover the most relevant areas for our project. The Mobile Game Probes generated many interesting results and new issues occurred, since the probes came to be dynamic and favorable for the process in new ways....

  17. Mineral chemistry and genesis of Zr, Th, U, Nb, Pb, P, Ce and F enriched peralkaline granites of El-Sibai shear zone, Central Eastern Desert, Egypt

    Directory of Open Access Journals (Sweden)

    Mohamed A. Ali


    Full Text Available El-Sibai mineralized shear zone trending NNE-SSW is located at the northern segment of Gabal El-Sibai (500m in length and 0.5 to 1.5 m in width. Rocks along the shear zone show different types of alterations such ashematization, kaolinitization, fluoritization, and silicification. These alterations are good traps for rare metals ofthorite, ferrocolumbite, pyroclore, plumbopyroclore, fluorite, cerite-(Ce, zircon, Th-rich zircon, zirconolite (mixtureof zircon & columbite, fluorapatite, titanite, and monazite minerals.The detailed mineralogical study of the El-Sibai shear zone revealed its enrichment in Th, Zr, Nb, Pb, U, F, P,LREE (Ce, especially concerning the hematization processes. The close correlation of ferruginated (hematitizedsamples with high radioactivity is related to the high ability of iron oxides for adsorption of radioactive elementsfrom their solutions. The rare-metal minerals found in altered peralkaline granites (shear zone are associated withhematitization, albititization, chloritization, fluoritization, and pyritization. Electron probe microanalysis (EPMAprovides an indication of a range of solid solution between thorite and zircon, in which intermediate phases, such asTh-rich zircon were formed. These phases have higher sum of all cations per formula (2.0 to 2.09 atoms per formulaunit, for 4 oxygen atoms than that of ideal thorite and zircon. This is attributed to the presence of substantialamount of interstitial cations such as U, Y, Ca, and Al in these phases. Altered zircon enriched in Th and U (Th-richzircon preferentially involves coupled substitution Ca2+ + (Th,U4+ ↔ 2Zr4+ + 2Si4+, implying that significant amountof U and Th may enter the Zr and Si position in zircon.Thorite and Th-rich zircon are related to hydrothermal fluid. Also the genesis of the studied zircon is related tometasomatic hydrothermal zircon (MHZ. The abundantly detected zircon, Th-rich zircon, Th-bearing minerals andfluorite of demonstrably

  18. Confidence in generic drug substitution. (United States)

    Lionberger, R; Jiang, W; Huang, S-M; Geba, G


    Patients should have confidence that the generic drugs they are prescribed in the United States can be effectively substituted for the brand product or another generic product. Through new bioequivalence study designs for narrow therapeutic index (NTI) drugs and postapproval studies of generic substitution, the US Food and Drug Administration's (FDA's) ongoing generic drug regulatory science activities are designed to ensure successful generic substitution for all drug products.

  19. Low-cost Ce1-xSmx(Fe, Co, Ti12 alloys for permanent magnets

    Directory of Open Access Journals (Sweden)

    A. M. Gabay


    Full Text Available Ce1-xSmxFe9Co2Ti alloys based on the ThMn12-type crystal structure have been synthesized via melt-spinning of prefabricated alloys and via mechanochemical processing of CeO2- Sm2O3- Fe2O3-TiO2- Co - Ca - CaO powder mixtures. Coercive fields up to 0.8 kOe and 2.1 kOe were obtained in annealed melt-spun alloys with x = 0 and x = 0.5, respectively. Submicron, partially anisotropic particles collected after the mechanochemical synthesis for x = 0.5 and x = 1 exhibited coercivity (energy product of 1.8 kOe (5.4 MGOe and 5.8 kOe (9.9 MGOe, respectively. The low magnetic anisotropy field of CeFe9Co2Ti alloy requires at least a partial Sm-substitution for Ce in order to develop a reasonably high coercivity.


    Directory of Open Access Journals (Sweden)

    Ádám Simon


    Full Text Available Identification of animal species from foodstuffs is important in order to identify frauds to prevent substitutions and admixtures in animal products. In this paper we demonstrate the identification of cattle and pig species by polymerase chain reaction (PCR capillary electrophoresis - single stranded conformation polymorphism (CE-SSCP method. The procedure is based on the amplification of the 12S rRNA gene encoded in the mitochondrial DNA (mtDNA. Since mtDNA copy number is highly tissue dependent mixtures of different pig tissues in cattle meat were prepared, at a concentration of 1, 5, 10, 20 w/w% of pig lard, liver and loin. It was determined that regardless the tissue type pig DNA can be detected by CE-SSCP at each contamination level.

  1. Photoluminescence mechanisms of color-tunable Sr2CeO4: Eu3+, Dy3+ phosphors based on experimental and first-principles investigation (United States)

    Li, Jie; Li, Xi; Hu, Shengliang; Li, Yingchun; Hao, Yuying


    We report single-phased color-tunable phosphors (Sr2CeO4: Eu3+, Dy3+) synthesized by a polymer-network gel method for UV-LED. The photoluminescence properties and possible energy transfer mechanisms of Eu3+ and Dy3+ in Sr2CeO4 were investigated by experiments and first principles calculations. The results show that the 5D0 → 7F2 emission of Eu3+ is enhanced by the increase in the amount of Eu3+ ions and Eu3+ substitution makes more stable defect than Dy3+ substitution does. The photoluminescence mechanism of Sr1.994-xEuxDy0.006CeO4 can be explained by the energy transfer model with the consideration of the defect conditions in the crystals.

  2. Electrical transport and magnetic properties of (Ce sub 1 sub - sub x Gd sub x)Pt sub 2 Si sub 2 (0 <= x <= 1)

    CERN Document Server

    Tchokonte, M B T; Kaczorowski, D


    Results of electrical resistivity, magnetization and susceptibility measurements are reported for the pseudo-ternary alloys (Ce sub 1 sub - sub x Gd sub x)Pt sub 2 Si sub 2. The end-members of the alloy series are the non-magnetic Kondo lattice compound CePt sub 2 Si sub 2 and the antiferromagnet GdPt sub 2 Si sub 2. The resistivity results reveal a rapid evolution to Kondo behaviour beyond small Ce substitution in GdPt sub 2 Si sub 2 (for 1 - x >= 0.2). Coherent Kondo scattering is observed for larger Ce substitution (1 - x >= 0.75). The low-temperature resistivity of CePt sub 2 Si sub 2 in the coherent state is dominantly a T sup 2 Fermi-liquid behaviour. The magnetization results suggest metamagnetic behaviour at Gd-rich concentrations. From the susceptibility results, the Gd and Ce moments seem to contribute independently to the magnetism of the alloy samples.

  3. Thermoelectric transport properties of nanostructured FeSb 2 and Ce-based heavy-fermions CeCu and CeAl 3 (United States)

    Pokharel, Mani R.

    Thermoelectric (TE) energy conversion is an all-solid-state technology which can convert waste thermal energy into useful electric power and cool ambience without using harmful gases like CFC. Due to their several advantages over traditional energy conversion technologies, thermoelectric generators (TEG) and coolers (TEC) have drawn enormous research efforts. The objective of this work is to find promising materials for thermoelectric cooling applications and optimize their thermoelectric performances. Finding a material with a good value for the thermoelectric figure-of-merit (ZT) at cryogenic temperatures, specifically below 77 K, has been of great interest. This work demonstrates that FeSb2 1, CeCu6 2 and CeAl3 3, all belonging to a class of materials with strongly correlated electron behavior; exhibit promising thermoelectric properties below 77 K. In general, ZT of a TE material can be increased using two basic approaches: lattice thermal conductivity reduction and power factor (PF) enhancement. The results of this study indicate that nanostructuring effectively decreases the thermal conductivity of FeSb2, CeCu6 and CeAl 3 leading to improved ZT. The approach of introducing point-defect scattering to further reduce the thermal conductivity is successfully implemented for Te-substituted FeSb2 nanostructured samples 4. A semiconductor/metal interface has long been proposed to exhibit enhanced thermoelectric properties. We use this technique by introducing Ag-nanoparticles in the host FeSb2 which further increases ZT by 70% 5. Additionally, a detailed investigation is made on the phonon-drag effect as a possible mechanism responsible for the large value of the Seebeck coefficient of FeSb2 6. We show that the phonon-drag mechanism contributes significantly to the large Seebeck effect in FeSb2 and hence this effect cannot be minor as was proposed in literatures previously. A model based on Kapitza-resistance and effective medium approach (EMA) is used to analyze

  4. Effect of pore size and cross-linking of a novel collagen-elastin dermal substitute on wound healing

    NARCIS (Netherlands)

    Boekema, B.K.H.L.; Vlig, M.; Damink, L.O.; Middelkoop, E.; Eummelen, L.; Buhren, A.V.; Ulrich, M.M.W.


    Collagen-elastin (CE) scaffolds are frequently used for dermal replacement in the treatment of full-thickness skin defects such as burn wounds. But little is known about the optimal pore size and level of cross-linking. Different formulations of dermal substitutes with unidirectional pores were

  5. Parallel Probe Readout

    NARCIS (Netherlands)

    Koelmans, W.W.


    In this thesis techniques are developed to read out nanoscale probes and arrays of probes.The main targeted application area is probe-based data storage.The work also contributes to other areas, such as metrology, biological sensing, materials research and nano-electro-mechanical switches. First, an

  6. New approaches in sensitive chiral CE. (United States)

    Sánchez-Hernández, Laura; Guijarro-Diez, Miguel; Marina, María Luisa; Crego, Antonio L


    CE has shown to have a big potential for chiral separations, with advantages such as high efficiency, high resolution, and low sample and reagents consumption. Nevertheless, when UV detection is employed, CE has some drawbacks, especially the low sensitivity obtained due to the short optical path length. Notwithstanding, sensitivity improvements can be achieved when different approaches are employed, such as sample treatment strategies (off-line or on-line), in-capillary sample preconcentration techniques, and/or alternative detection systems to UV-Vis (such as fluorescence, conductimetry, electrochemiluminiscence, MS, etc.). This article reviews the most recent methodological and instrumental advances reported from June 2011 to May 2013 for enhancing the sensitivity in chiral analysis by CE. The sensitivity achieved for the enantioseparated analytes and the applications carried out using the developed methodologies are also summarized. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Currency substitution in Eastern Europe

    NARCIS (Netherlands)

    van Aarle, B.; Budina, N.


    Monetary instability during the transition process from a command economy to a market economy has induced a considerable increase in currency substitution in Eastern Europe. Currency substitution itself affects monetary stability since it reduces the stability of velocity. This paper investigates

  8. Synthesis and luminescent study of Ce{sup 3+}-doped terbium-yttrium aluminum garnet

    Energy Technology Data Exchange (ETDEWEB)

    Dotsenko, V.P., E-mail: [A.V. Bogatsky Physico-Chemical Institute, National Academy of Sciences of Ukraine, Lustdorfskaya doroga 86, 65080 Odessa (Ukraine); Berezovskaya, I.V.; Zubar, E.V.; Efryushina, N.P. [A.V. Bogatsky Physico-Chemical Institute, National Academy of Sciences of Ukraine, Lustdorfskaya doroga 86, 65080 Odessa (Ukraine); Poletaev, N.I.; Doroshenko, Yu.A. [Institute of Combustion and Advanced Technologies, Mechnikov Odessa National University, Dvoryanskaya 2, 65082 Odessa (Ukraine); Stryganyuk, G.B. [Ivan Franko National University of Lviv, Kirilo i Mefodii 8, 79005 Lviv (Ukraine); HASYLAB at DESY, Notkestrasse 85, 22607 Hamburg (Germany); Voloshinovskii, A.S. [Ivan Franko National University of Lviv, Kirilo i Mefodii 8, 79005 Lviv (Ukraine)


    Highlights: Black-Right-Pointing-Pointer Ce{sup 3+}-doped garnets (TYAG) were prepared using nanostructured reagents. Black-Right-Pointing-Pointer The Ce{sup 3+} ions cause a very efficient yellow emission of the samples. Black-Right-Pointing-Pointer The reasons for the long wavelength position of this emission are discussed. Black-Right-Pointing-Pointer Contribution from Al atoms to the conduction band of TYAG is quite essential. - Abstract: Terbium-yttrium aluminum garnets (TYAG) doped with Ce{sup 3+} ions have been prepared by solid state reactions between nanostructured oxides of aluminum and rare earths. The luminescent properties of Ce{sup 3+} ions in (Tb{sub 0.8}Y{sub 0.2}){sub 3(1-x)}Ce{sub 3x}Al{sub 5}O{sub 12} (x = 0.03) have been studied upon excitation in the 2-20 eV region. The substitution of Tb{sup 3+} for Y{sup 3+} in the garnet structure results in broadening the emission band and shifting its maximum towards the longer wavelengths. It was found that in addition to the 4f{sup n} {yields} 4f{sup n-1}5d excitation bands of Ce{sup 3+} and Tb{sup 3+} ions, the excitation spectra for the Ce{sup 3+} emission contain broad bands at 6.73 and {approx}9.5 eV. These bands are attributed to the Ce{sup 3+}-bound exciton formation and O 2p {yields} Al 3s, 3p transitions, respectively. In contrast to the predictions based on the results of electronic structure calculations on Y{sub 3}Al{sub 5}O{sub 12} and Tb{sub 4}Al{sub 2}O{sub 9}, the threshold of interband transitions in TYAG is at high energies ( Greater-Than-Or-Slanted-Equal-To 7.3 eV), and contributions from Al{sub tetr} and Al{sub oct} atoms to the conduction-band density of states are evaluated as quite essential.

  9. How Do Substitute Teachers Substitute? An Empirical Study of Substitute-Teacher Labor Supply (United States)

    Gershenson, Seth


    This paper examines the daily labor supply of a potentially important, but often overlooked, source of instruction in U.S. public schools: substitute teachers. I estimate a sequential binary-choice model of substitute teachers' job-offer acceptance decisions using data on job offers made by a randomized automated calling system. Importantly, this…

  10. Comparison of fungal carbohydrate esterases of family CE16 on artificial and natural substrates. (United States)

    Puchart, Vladimír; Agger, Jane W; Berrin, Jean-Guy; Várnai, Anikó; Westereng, Bjørge; Biely, Peter


    The enzymatic conversion of acetylated hardwood glucuronoxylan to functional food oligomers, biochemicals or fermentable monomers requires besides glycoside hydrolases enzymes liberating acetic acid esterifying position 2 and/or 3 in xylopyranosyl (Xylp) residues. The 3-O-acetyl group at internal Xylp residues substituted by MeGlcA is the only acetyl group of hardwood acetylglucuronoxylan and its fragments not attacked by acetylxylan esterases of carbohydrate esterase (CE) families 1, 4, 5 and 6 and by hemicellulolytic acetyl esterases classified in CE family 16. Monoacetylated aldotetraouronic acid 3″-Ac(3)MeGlcA(3)Xyl3, generated from the polysaccharide by GH10 endoxylanases, appears to be one of the most resistant fragments. The presence of the two substituents on the non-reducing-end Xylp residue prevents liberation of MeGlcA by α-glucuronidase of family GH67 and blocks the action of acetylxylan esterases. The Ac(3)MeGlcA(3)Xyl3 was isolated from an enzymatic hydrolysate of birchwood acetylglucuronoxylan and characterized by (1)H NMR spectroscopy as a mixture of two positional isomers, 3″-Ac(3)MeGlcA(3)Xyl3 and 4″-Ac(3)MeGlcA(3)Xyl3, the latter being the result of acetyl group migration. The mixture was used as a substrate for three members of CE16 family of fungal origin. Trichoderma reesei CE16 esterase, inactive on polymeric substrate, deacetylated both isomers. Podospora anserina and Aspergillus niger esterases, active on acetylglucuronoxylan, deesterified effectively only the 4″-isomer. The results indicate catalytic diversity among CE16 enzymes, but also their common and unifying catalytic ability to exo-deacetylate positions 3 and 4 on non-reducing-end Xylp residues, which is an important step in plant hemicellulose saccharification. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Vitreous substitutes: challenges and directions. (United States)

    Gao, Qian-Ying; Fu, Yue; Hui, Yan-Nian


    The natural vitreous body has a fine structure and complex functions. The imitation of the natural vitreous body by vitreous substitutes is a challenging work for both researchers and ophthalmologists. Gases, silicone oil, heavy silicone oil and hydrogels, particularly the former two vitreous substitutes are clinically widely used with certain complications. Those, however, are not real artificial vitreous due to lack of structure and function like the natural vitreous body. This article reviews the situations, challenges, and future directions in the development of vitreous substitutes, particularly the experimental and clinical use of a new artificial foldable capsular vitreous body.

  12. Improved thermal quenching of Y{sub 3}Al{sub 5}O{sub 12}:Ce phosphor ceramics with silica addition

    Energy Technology Data Exchange (ETDEWEB)

    Nien, Yung-Tang, E-mail:; You, Jyun-Kai


    Y{sub 3}Al{sub 5}O{sub 12}:Ce (YAG:Ce) is widely used in light emitting diodes (LEDs) for the conversion of blue light into yellow light. However, thermal quenching has become a severe problem for high-power LEDs because more heat is generated by high-power LED chips; this results in the reduction of emission intensity and unit life. In this research, silica was fired with co-precipitated YAG:Ce phosphor ceramics to study the photoluminescent thermal quenching behavior by comparing with pristine YAG:Ce. The results showed that silica-added YAG:Ce phosphor ceramics exhibited an increase of more than 15% in quantum efficiency and a higher thermal quenching temperature compared with pristine YAG:Ce. This improvement in thermal stability (10% increase at 150 °C) in silica-added YAG:Ce phosphor ceramics was attributed to a denser microstructure and an increase in thermal activation energy by Si substitution of Al in the host. - Highlights: • An increase of 15% in quantum efficiency (from 32.4% to 47.4%) is achieved. • A lower emission intensity reduction at 150 °C (from 30% to 20%) is obtained. • Si induced a denser microstructure and an increase in thermal activation energy.

  13. Insight into the hard-soft acid-base properties of differently substituted phenylhydrazines in reactions with dimethyl carbonate. (United States)

    Rosamilia, Anthony E; Aricò, Fabio; Tundo, Pietro


    Following the preliminary studies on the reactivity of the ambident nucleophile phenylhydrazine with dimethyl carbonate, investigations involving para-substituted phenylhydrazines were carried out in order to probe differences in the reactivity within this class of nucleophile. Phenylhydrazines substituted by electron withdrawing or donating substituents showed an increase in reactivity of the phenylhydrazine toward dimethyl carbonate. Under the basic conditions used, all phenylhydrazines displayed hard nucleophilicity, signifying that para-substitution on the phenyl ring has little effect on the hard-soft behavior of this class of nucleophile. This conclusion fits well within the results previously obtained using other para-substituted nucleophiles, i.e., phenols.

  14. Tuning Ce distribution for high performanced Nd-Ce-Fe-B sintered magnets

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Xiaodong [School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048 (China); Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Science, Ningbo 315201 (China); Guo, Shuai; Chen, Kan; Chen, Renjie; Lee, Don [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Science, Ningbo 315201 (China); You, Caiyin, E-mail: [School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048 (China); Yan, Aru, E-mail: [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Science, Ningbo 315201 (China)


    A dual-alloy method was applied to tune the distribution of Ce for enhancing the performance of Nd-Ce-Fe-B sintered magnets with a nominal composition of (Nd{sub 0.75}Ce{sub 0.25}){sub 30.5}Fe{sub bal}Al{sub 0.1}Cu{sub 0.1}B. In comparison to the single alloy of (Nd{sub 0.75}Ce{sub 0.25}){sub 30.5}Fe{sub bal}Al{sub 0.1}Cu{sub 0.1}B, the coercivity was enhanced from 10.3 kOe to 12.1 kOe and the remanence was increased from 13.1 kG to 13.3 kG for the magnets with a dual-alloy method. In addition, the remanence temperature coefficient α and coercivity temperature coefficient β were also slightly improved for the magnet with the dual alloys. The results of microstructure characterizations show the uniform distribution of Ce for the magnet with a single alloy, and the coexistence of the Ce-rich and Ce-lean regions for the magnet with the dual alloys. In combinations with the nucleation of reversal domains and magnetic recoil curves, the property enhancement of magnets with a dual-alloy method was well explained. - Highlights: • Improved magnetic properties were obtained in dual-alloy magnet. • This is due to the tuning of Ce distribution and the change in microstructure. • The magnetic hardening effect can be observed in dual-alloy magnet.

  15. Dyscravia: voicing substitution dysgraphia. (United States)

    Gvion, Aviah; Friedmann, Naama


    We report a new type of dysgraphia, which we term dyscravia. The main error type in dyscravia is substitution of the target letter with a letter that differs only with respect to the voicing feature, such as writing "coat" for "goat", and "vagd" for "fact". Two Hebrew-speaking individuals with acquired dyscravia are reported, TG, a man aged 31, and BG, a woman aged 66. Both had surface dysgraphia in addition to their dyscravia. To describe dyscravia in detail, and to explore the rate and types of errors made in spelling, we administered tests of writing to dictation, written naming, and oral spelling. In writing to dictation, TG made voicing errors on 38% of the words, and BG made 17% voicing errors. Voicing errors also occurred in nonword writing (43% for TG, 56% for BG). The writing performance and the variables that influenced the participants' spelling, as well as the results of the auditory discrimination and repetition tasks indicated that their dyscravia did not result from a deficit in auditory processing, the graphemic buffer, the phonological output lexicon, the phonological output buffer, or the allographic stage. The locus of the deficit is the phoneme-to-grapheme conversion, in a function specialized in the conversion of phonemes' voicing feature into graphemes. Because these participants had surface dysgraphia and were forced to write via the sublexical route, the deficit in voicing was evident in their writing of both words and nonwords. We further examined whether the participants also evinced parallel errors in reading. TG had a selective voicing deficit in writing, and did not show any voicing errors in reading, whereas BG had voicing errors also in the reading of nonwords (i.e., she had dyslegzia in addition to dyscravia). The dissociation TG demonstrated indicated that the voicing feature conversion is separate for reading and writing, and can be impaired selectively in writing. BG's dyslegzia indicates that the grapheme-to-phoneme conversion

  16. Commercial formalin substitutes for histopathology

    DEFF Research Database (Denmark)

    Prentø, P; Lyon, H


    We compared the performance of six commercial fixatives proposed to be formalin substitutes with the performance of buffered formalin, Clarke's ethanol-acetic acid, and ethanol, using rat liver, small intestine, and kidney. We investigated the rate of penetration, mode of fixation, extent of prot...... was obtained by combining formalin fixation with antigen retrieval. We conclude that none of the proposed commercial substitutes for buffered formalin are adequate for critical histology or histopathology....

  17. INCA-CE project: status and results (United States)

    Strauss, Franziska; Meirold-Mautner, Ingo; Bica, Benedikt; Kann, Alexander; Wang, Yong


    Every year, Central Europe (CE) is affected by weather extremes challenging civil protection authorities, hydrologists and road maintenance services to timely warnings. Within the INCA-CE project (Integrated Nowcasting through Comprehensive Analysis in Central Europe; which is supported by the European Regional Development Fund a deepened transnational cooperation between meteorological/hydrological services and three application areas is established. This guarantees for both enhancements of meteorological products in the sense of end-user friendliness, and standardized information exchange across borders. At present, INCA-CE is the only project throughout the world which connects cooperation to such an extent with respect to its transnational and multidisciplinary framework (in the meanwhile it has been chosen as World Weather Research Programme/Forecast Demonstration Project by the World Meteorological Organization). Key partners from eight countries (from national meteorological/hydrological services and the three different application areas) accept the challenge to work on standardization and harmonization tools. Therefore, the INCA nowcasting system - developed at the Austrian weather service (ZAMG) in the 1990ies - has been implemented at all CE meteorological/hydrological services and is advanced and refined to the specific user needs to (i) provide high quality nowcasting products which are standardized and harmonized across borders, (ii) improve information chains from models to warnings and protection measures in case of disaster, and (iii) make the public and stakeholders more familiar with meteorological products. However, the potential to achieve these listed improvements is only possible through the intense transnational and multidisciplinary cooperation, because for one institution and one country alone it would be impossible to cope with all the necessary tasks. In this presentation the status and results of the INCA-CE

  18. Aqueous chemistry of Ce(iv): estimations using actinide analogues. (United States)

    Marsac, Rémi; Réal, Florent; Banik, Nidhu Lal; Pédrot, Mathieu; Pourret, Olivier; Vallet, Valérie


    The prediction of cerium (Ce) aqueous speciation is relevant in many research fields. Indeed, Ce compounds are used for many industrial applications, which may require the control of Ce aqueous chemistry for their synthesis. The aquatic geochemistry of Ce is also of interest. Due to its growing industrial use and its release into the environment, Ce is now considered as an emerging contaminant. Cerium is also used as a proxy of (paleo)redox conditions due to the Ce(iv)/Ce(iii) redox transition. Finally, Ce(iv) is often presented as a relevant analogue of tetravalent actinides (An(iv)). In the present study, quantum chemical calculations were conducted to highlight the similarities between the structures of Ce(iv) and tetravalent actinide (An(iv); An = Th, Pa, U, Np, Pu) aqua-ions, especially Pu(iv). The current knowledge of An(iv) hydrolysis, solubility and colloid formation in water was briefly reviewed but important discrepancies were observed in the available data for Ce(iv). Therefore, new estimations of the hydrolysis constants of Ce(iv) and the solubility of Ce(iv)-(hydr)oxides are proposed, by analogy with Pu(iv). By plotting pH-Eh (Pourbaix) diagrams, we showed that the pH values corresponding to the onset of Ce(iv) species formation (i.e. Ce(iv)-(hydr)oxide or dissolved Ce(iv)) agreed with various experimental results. Although further experimental studies are required to obtain a more accurate thermodynamic database, the present work might yet help to predict more accurately the Ce chemical behavior in aqueous solution.

  19. Facile hydrothermal synthesis of CeO2 nanopebbles

    Indian Academy of Sciences (India)

    Cerium oxide (CeO2) nanopebbles have been synthesized using a facile hydrothermal method. X-ray diffraction pattern (XRD) and transmission electron microscopy analyses confirm the presence of CeO2 nanopebbles. XRD shows the formation of cubic fluorite CeO2 and the average particle size estimated from the ...

  20. Structural and disorder effects on the magnetic behavior of Ce(In{sub 1−x}Ni{sub x}){sub 2} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, D.P., E-mail: [Departamento de Física e Instalaciones-ETSAM, Universidad Politécnica de Madrid, Av. Juan Herrera, 4. 28040 Madrid (Spain); Espeso, J.I.; Rodríguez Fernández, J. [CITIMAC and MAGMA, UA-CSIC, Facultad de Ciencias, Universidad de Cantabria, Av. de los Castros s/n.39005, Santander (Spain)


    We have investigated the evolution of the magnetic and thermal properties on the Ce(In{sub 1−x}Ni{sub x}){sub 2} (x=0.025 and 0.05) series of alloys. The orthorhombic structure of the CeIn{sub 2} alloy changes to hexagonal AlB{sub 2}-type for the Ni-diluted samples. The dc (ac) magnetic susceptibility and specific heat measurements show a change from first-order ferromagnetism in the CeIn{sub 2} alloy (x=0) to second order ferromagnetism upon chemical substitution of Ni, with an abrupt decrease of the transition temperature from 22 K to 6.3 K (x=0.025). The results indicate a preeminent role of the crystallographic type of structure and disorder effects on the magnetic behavior along the series. - Highlights: • First order ferromagnetic transition in binary CeIn{sub 2}. • Crossover to second order ones upon chemical substitution in the Ce(In{sub 1−x}Ni{sub x}){sub 2} series of alloys. • Abrupt decrease of the ordering temperature for small concentrations (x = 0.025 and 0.05) of Ni. • Crystallographic type of structure and disorder effects on the magnetic behavior.

  1. Influence of ionic liquids as electrolyte additives on chiral separation of dansylated amino acids by using Zn(II) complex mediated chiral ligand exchange CE. (United States)

    Zhang, Haizhi; Qi, Li; Mu, Xiaoyu; Zhou, Xiaoping; Li, Dan; Mao, Lanqun


    In this work, investigation of the comparative influence of diverse ionic liquids (ILs) as electrolyte additives on the chiral separation of dansylated amino acids by using Zn(II)-L-arginine complex mediated chiral ligand exchange CE (CLE-CE) was conducted. It has been found that not only the varied substituted group number, but also the alkyl chain length of the substituted group on imidazole ring in the structure of ILs show different influence on chiral separation of the analytes in the CLE-CE system, which could be understood by their direct influence on EOF. Meanwhile, the variation of anion in the structure of ILs displayed remarkably changed performance and the ILs with Cl(-) showed the most obvious promoting effect on the chiral separation performance. Among the investigated seven ILs, 1-butyl-3-methylimidazolium chloride was validated to be the proper electrolyte additive in the CLE-CE system. Moreover, it has been observed that 1-butyl-3-methylimidazolium chloride also has obvious promotive effect on the labeling performance. The results have demonstrated that the ILs with different structures have important relation to their performance in CLE-CE and to their labeling efficiency in dansylation of the analytes. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Superlattice structure of Ce{sup 3+}-doped BaMgF{sub 4} fluoride crystals - x-ray diffraction, electron spin-resonance, and optical investigations

    Energy Technology Data Exchange (ETDEWEB)

    Yamaga, M.; Hattori, K. [Department of Electrical and Electronic Engineering, Faculty of Engineering, Gifu University, Gifu (Japan); Kodama, N. [Department of Materials Science and Engineering, Faculty of Engineering and Resource Science, Akita University, Akita (Japan); Ishizawa, N. [Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama (Japan); Honda, M. [Faculty of Science, Naruto University of Education, Naruto (Japan); Shimamura, K.; Fukuda, T. [Institute for Materials Research, Tohoku University, Sendai (Japan)


    The x-ray diffraction patterns for Ce{sup 3+}-doped BaMgF{sub 4} (BMF) crystals suggest the existence of superlattice structure. The superlattice model is consistent with the characterization of the 4f{sup 1} ground state of Ce{sup 3+} as a probe ion using the electron spin-resonance (ESR) technique. The distinct Ce{sup 3+} luminescence spectra with different peak energies and lifetimes also support the superlattice model. Although the detailed superlattice structure could not be analysed using the diffraction spots, a model has been proposed, taking into account the eight Ce{sup 3+} polyhedra with different anion coordinations in the unit cell of the BMF crystal obtained from the ESR experiments. (author)

  3. Microchips for CE: breakthroughs in real-world food analysis. (United States)

    Escarpa, Alberto; González, María Cristina; López Gil, Miguel Angel; Crevillén, Agustín G; Hervás, Miriam; García, Miguel


    The well-known complexity of food matrices is approached using CE microchips with different strategies to improve the selectivity and sensitivity of the analysis by avoiding and/or making the sample preparation as simple as possible: (i) enhancing the peak capacity in order to perform direct injection, (ii) using the microchip platform to measure one target analyte/group of analytes with or without separating other related interferences, (iii) integrating sample preparation steps on the microchip platform, and (iv) integrating new analytical tools from nanotechnology in the detection stage. New analyte separations of food significance involving DNA probes, biogenic amines, vanilla flavors, and dyes have been reported as successfully breaking new barriers in areas of high impact in the market, such as transgenic food analysis, as well as the detection of frauds and toxins. Simple microchip layouts are still the most common designs used, though sophisticated new ones are emerging. In contrast to other application areas, electrochemical detection continues to be the most common detection route, followed by LIF, though non-conventional detection routes are also emerging, such as chemiluminescence or UV. In terms of analytical performance, the integration of calibration and quality control on a microchip platform, and remarkable accuracy and precision are being obtained using creative analytical methodologies that enhance the analytical potency of microfluidic chips for their future commercialization. This review critically states the most important advances derived from work done in the field over the past 2-3 years.

  4. The 144Ce source for SOX (United States)

    Durero, M.; Vivier, M.; Agostini, M.; Altenmüller, K.; Appel, S.; Bellini, G.; Benziger, J.; Berton, N.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Cavalcante, P.; Chepurnov, A.; Choi, K.; Cribier, M.; D'Angelo, D.; Davini, S.; Derbin, A.; Di Noto, L.; Drachnev, I.; Etenko, A.; Farinon, S.; Fischer, V.; Fomenko, K.; Franco, D.; Gabriele, F.; Gaffiot, J.; Galbiati, C.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Houdy, T.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Jonqueres, N.; Jedrzejczak, K.; Kaiser, M.; Kobychev, V.; Korablev, D.; Korga, G.; Kornoukhov; Kryn, D.; Lachenmaier, T.; Lasserre, T.; Laubenstein, M.; Lehnert, B.; Link, J.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Maricic, J.; Mention, G.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Muratova, V.; Musenich, R.; Neumair, B.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Perasso, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Roncin, R.; Rossi, N.; Schönert, S.; Scola, L.; Semenov, D.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov; Tartaglia, R.; Testera, G.; Thurn, J.; Toropova, M.; Veyssiére, C.; Unzhakov, E.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Weinz, S.; Winter, J.; Wojcik, M.; Wurm, M.; Yokley, Z.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.


    The SOX (Short distance neutrino Oscillations with BoreXino) project aims at testing the light sterile neutrino hypothesis. To do so, two artificials sources of antineutrinos and neutrinos respectively will be consecutively deployed at the Laboratori Nazionali del Gran Sasso (LNGS) in close vicinity to Borexino, a large liquid scintillator detector. This document reports on the source production and transportation. The source should exhibit a long lifetime and a high decay energy, a requirement fullfilled by the 144Ce-144Pr pair at secular equilibrium. It will be produced at FSUE “Mayak” PA using spent nuclear fuel. It will then be shielded and packed according to international regulation and shipped to LNGS across Europe. Knowledge of the Cerium antineutrino generator (CeANG) parameters is crucial for SOX as it can strongly impact the experiment sensitivity. Several apparatuses are being used or designed to characterize CeANG activity, radioactive emission and content. An overview of the measurements performed so far is presented here.

  5. Formative Assessment Probes (United States)

    Eberle, Francis; Keeley, Page


    Formative assessment probes can be effective tools to help teachers build a bridge between students' initial ideas and scientific ones. In this article, the authors describe how using two formative assessment probes can help teachers determine the extent to which students make similar connections between developing a concept of matter and a…

  6. Effect of trace Ce and B additions on the microstructure of Nb-3Si-22Ti alloys

    Directory of Open Access Journals (Sweden)

    Meiling Wu


    Full Text Available The effects of trace Ce and B additions on the microstructure Nb-22Ti-3Si alloys were studied. The microstructure of the alloys was observed by scanning electron microscope (SEM, and their phase compositions were analyzed with X-ray diffraction (XRD and Electro-Probe micro-analyzer (EPMA. The distributions of the elements were detected by Spectrum analyzer. The interface of the phases in the alloys was investigated by transmission electron microscopy (TEM. The results indicated that two phases of Nbss and Nb3Si presented in Nb-22Ti-3Si, Nb-22Ti-3Si-0.2Ce and Nb-22Ti-3Si-0.2B alloys. The segregation of Ti at the interface between Nbss and Nb3Si was promoted and the volume fraction of silicides in the alloy increased with the trace B and Ce addition to the Nb-22Ti-3Si alloy respectively. And there was no single and definite orientation relationship between Nb3Si and Nbss in Nb-22Ti-3Si, Nb-22Ti-3Si-0.2Ce and Nb-22Ti-3Si-0.2B alloys. Compared with the Nb-22Ti-3Si alloy, the Nbss superlattice structure was found in Nb-22Ti-3Si-0.2Ce and Nb-22Ti-3Si-0.2B alloys.

  7. Inflatable traversing probe seal (United States)

    Trimarchi, Paul A.


    An inflatable seal acts as a pressure-tight zipper to provide traversing capability for instrumentation rakes and probes. A specially designed probe segment with a teardrop cross-section in the vicinity of the inflatable seal minimizes leakage at the interface. The probe is able to travel through a lengthwise slot in a pressure vessel or wind tunnel section, while still maintaining pressure integrity. The design uses two commercially available inflatable seals, opposing each other, to cover the probe slot in a wind tunnel wall. Proof-of-concept tests were conducted at vessel pressures up to 30 psig, with seals inflated to 50 psig, showing no measurable leakage along the seal's length or around the probe teardrop cross-section. This seal concept can replace the existing technology of sliding face plate/O-ring systems in applications where lengthwise space is limited.

  8. Flame Synthesis of Nanosized Cu-Ce-O, Ni-Ce-O, and Fe-Ce-O Catalysts for the Water-Gas Shift (WGS) Reaction (United States)


    by the flame synthesis method using cerium acetate dissolved in a mixture of acetic acid, 2- butanol , and isooctane (40). In this process, the...gas shift reaction over the Cu-Ce-O, Ni-Ce-O, and Fe-Ce-O catalysts to elu- cidate the catalytic properties of these flame-made ceria- based materials...driven by the system minimizing its surface energy, to form a thermodynamically more stable nanoparticle (42). Therefore, drawing an analogy between

  9. Approaches in Substitution of Organic Solvents

    DEFF Research Database (Denmark)

    Jacobsen, Thomas


    In substitution of harmful chemicals or products with less harmful or harmless ones, there are different approaches according to the different situations, the technical requirements to the substitutes, and the goals for the substitution. Three different cases are presented. The substitution proce...

  10. Ultra-shallow junction (USJ) sheet resistance measurements with a non-penetrating four point probe (United States)

    Benjamin, M. C.; Hillard, R. J.; Borland, J. O.


    An accurate method to measure the four point probe (4PP) sheet resistance (RS) of ultra shallow junction (USJ) Source-Drain Extension structures is described. The method utilizes Elastic Material probes (EM-probes) to form non-penetrating contacts to the silicon surface [R.J. Hillard, P.Y. Hung, William Chism, C. Win Ye, W.H. Howland, L.C. Tan, C.E. Kalnas, Characterization and Metrology for ULSI Technology, AIP Conference proceedings 683 (2003) 802.]. The probe design is kinematic and the force is controlled to ensure elastic deformation of the probe material. The probe material is such that large direct tunneling currents can flow through the native oxide thereby forming a low impedance contact. Sheet resistance measurements on USJ implanted P+/N structures with Secondary Ion Mass Spectroscopy (SIMS) junction depths less than 15 nm have been measured. The method is demonstrated on implanted USJ structures and found to be consistent with expectations.

  11. [Effects of Arbuscular Mycorrhizal Fungi on the Growth and Ce Uptake of Maize Grown in Ce-contaminated Soils]. (United States)

    Wang, Fang; Guo, Weil; Ma, Peng-kun; Pan, Liang; Zhang, Jun


    A greenhouse pot experiment was conducted to investigate the effects of arbuscular mycorrhizal (AM) fungi Glomus aggregatum (GA) and Funneliformis mosseae (FM) on AM colonization rate, biomass, nutrient uptake, C: N: P stoichiometric and Ce uptake and transport by maize (Zea mays L.) grown in soils with different levels of Ce-contaminated (100, 500 and 1000 mg x kg(-1)). The aim was to provide basic data and technical support for the treatment of soils contaminated by rare earth elements. The results indicated that symbiotic associations were successfully established between the two isolates and maize, and the average AM colonization rate ranged from 7. 12% to 74.47%. The increasing concentration of Ce in soils significantly decreased the mycorrhizal colonization rate, biomass, nutrition contents and transport rate of Ce from root to shoot of maize, and significantly increased C: P and N: P ratios and Ce contents in shoot and root of maize. Both AM fungi inoculations promoted the growth of maize, but the promoting role of FM was more significant than that of GA in severe Ce-contaminated soils. There were no significant differences in the growth of maize between two AM fungi in mild and moderate Ce-contaminated soils. Inoculation with AM fungi significantly improved nutritional status of maize by increasing nutrient uptake and decreasing C: N: P ratios. GA was more efficient than FM in enhancing nutrient uptake in mild and moderate Ce-contaminated soils, while FM was more efficient in severe Ce-contaminated soils. Moreover, inoculation with AM fungi significantly increased Ce contents of shoot and root in mild Ce-contaminated soils, but had no significant effect on Ce contents of maize in moderate and severe Ce-contaminated soils, and promoted the transport of Ce from root to shoot. The experiment demonstrates that AM fungi can alleviate toxic effects of Ce on plants and have a potential role in the phytoremediation of soils contaminated by rare earth elements.

  12. Recent advances in CE and microchip-CE in clinical applications: 2014 to mid-2017. (United States)

    Phillips, Terry M


    CE and microchip CE (ME) are powerful tools for the analysis of a number of different analytes and have been applied to a variety of clinical fields and human samples. This review will present an overview of the most recent applications of these techniques to different areas of clinical medicine during the period of 2014 to mid-2017. CE and ME have been applied to clinical chemistry, drug detection and monitoring, hematology, infectious diseases, oncology, endocrinology, neonatology, nephrology, and genetic screening. Samples examined range from serum, plasma, and urine to lest utilized materials such as tears, cerebral spinal fluid, sweat, saliva, condensed breath, single cells, and biopsy tissue. Examples of clinical applications will be given along with the various detection systems employed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. 40 CFR 721.10040 - Substituted acridine naphtha substituted benzamide (generic). (United States)


    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted acridine naphtha... Significant New Uses for Specific Chemical Substances § 721.10040 Substituted acridine naphtha substituted... substance identified generically as a substituted acridine naphtha substituted benzamide (PMN P-02-522) is...

  14. Foldable polymers as probes (United States)

    Li, Alexander D. Q.; Wang, Wei


    Disclosed herein are novel probes, which can be used to detect and identify target molecules of interest in a sample. The disclosed probes can be used to monitor conformational changes induced by molecular recognition events in addition to providing signaling the presence and/or identity of a target molecule. Methods, including solid phase synthesis techniques, for making probe molecules that exhibit changes in their optical properties upon target molecule binding are described in the disclosure. Also disclosed herein are novel chromophore moieties, which have tailored fluorescent emission spectra.

  15. Crystal structure and anisotropic magnetic properties of new ferromagnetic Kondo lattice compound Ce(Cu,Al,Si){sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, A.; Thamizhavel, A.; Dhar, S.K. [Department of Condensed Matter Physics & Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India); Provino, A.; Pani, M.; Costa, G.A. [Department of Chemistry, University of Genova, Via Dodecaneso 31, 16146 Genova (Italy); Institute SPIN-CNR, Corso Perrone 24, 16152 Genova (Italy)


    Single crystals of the new compound CeCu{sub 0.18}Al{sub 0.24}Si{sub 1.58} have been grown by high-temperature solution growth method using a eutectic Al-Si mixture as flux. This compound is derived from the binary CeSi{sub 2} (tetragonal α-ThSi{sub 2}-type, Pearson symbol tI12, space group I4{sub 1}/amd) obtained by partial substitution of Si by Cu and Al atoms but showing full occupation of the Si crystal site (8e). While CeSi{sub 2} is a well-known valence-fluctuating paramagnetic compound, the CeCu{sub 0.18}Al{sub 0.24}Si{sub 1.58} phase orders ferromagnetically at T{sub C}=9.3 K. At low temperatures the easy-axis of magnetization is along the a-axis, which re-orients itself along the c-axis above 30 K. The presence of hysteresis in the magnetization curve, negative temperature coefficient of resistivity at high temperatures, reduced jump in the heat capacity and a relatively lower entropy released up to the ordering temperature, and enhanced Sommerfeld coefficient (≈100 mJ/mol K{sup 2}) show that CeCu{sub 0.18}Al{sub 0.24}Si{sub 1.58} is a Kondo lattice ferromagnetic, moderate heavy fermion compound. Analysis of the high temperature heat capacity data in the paramagnetic region lets us infer that the crystal electric field split doublet levels are located at 178 and 357 K, respectively, and Kondo temperature (8.4 K) is of the order of T{sub C} in CeCu{sub 0.18}Al{sub 0.24}Si{sub 1.58}.

  16. Probing catalytic rate enhancement during intramembrane proteolysis. (United States)

    Arutyunova, Elena; Smithers, Cameron C; Corradi, Valentina; Espiritu, Adam C; Young, Howard S; Tieleman, D Peter; Lemieux, M Joanne


    Rhomboids are ubiquitous intramembrane serine proteases involved in various signaling pathways. While the high-resolution structures of the Escherichia coli rhomboid GlpG with various inhibitors revealed an active site comprised of a serine-histidine dyad and an extensive oxyanion hole, the molecular details of rhomboid catalysis were unclear because substrates are unknown for most of the family members. Here we used the only known physiological pair of AarA rhomboid with its psTatA substrate to decipher the contribution of catalytically important residues to the reaction rate enhancement. An MD-refined homology model of AarA was used to identify residues important for catalysis. We demonstrated that the AarA active site geometry is strict and intolerant to alterations. We probed the roles of H83 and N87 oxyanion hole residues and determined that substitution of H83 either abolished AarA activity or reduced the transition state stabilization energy (ΔΔG‡) by 3.1 kcal/mol; substitution of N87 decreased ΔΔG‡ by 1.6-3.9 kcal/mol. Substitution M154, a residue conserved in most rhomboids that stabilizes the catalytic general base, to tyrosine, provided insight into the mechanism of nucleophile generation for the catalytic dyad. This study provides a quantitative evaluation of the role of several residues important for hydrolytic efficiency and oxyanion stabilization during intramembrane proteolysis.

  17. Substitution determination of Fmoc‐substituted resins at different wavelengths (United States)

    Kley, Markus; Bächle, Dirk; Loidl, Günther; Meier, Thomas; Samson, Daniel


    In solid‐phase peptide synthesis, the nominal batch size is calculated using the starting resin substitution and the mass of the starting resin. The starting resin substitution constitutes the basis for the calculation of a whole set of important process parameters, such as the number of amino acid derivative equivalents. For Fmoc‐substituted resins, substitution determination is often performed by suspending the Fmoc‐protected starting resin in 20% (v/v) piperidine in DMF to generate the dibenzofulvene–piperidine adduct that is quantified by ultraviolet–visible spectroscopy. The spectrometric measurement is performed at the maximum absorption wavelength of the dibenzofulvene–piperidine adduct, that is, at 301.0 nm. The recorded absorption value, the resin weight and the volume are entered into an equation derived from Lambert–Beer's law, together with the substance‐specific molar absorption coefficient at 301.0 nm, in order to calculate the nominal substitution. To our knowledge, molar absorption coefficients between 7100 l mol−1 cm−1 and 8100 l mol−1 cm−1 have been reported for the dibenzofulvene–piperidine adduct at 301.0 nm. Depending on the applied value, the nominal batch size may differ up to 14%. In this publication, a determination of the molar absorption coefficients at 301.0 and 289.8 nm is reported. Furthermore, proof is given that by measuring the absorption at 289.8 nm the impact of wavelength accuracy is reduced. © 2017 The Authors Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd. PMID:28635051

  18. Ce que les nanoparticules font aux chimistes


    Vinck, D.


    En observant les dynamiques scientifiques et institutionnelles à l'oeuvre autour du développement des nanosciences et des nanotechnologies, on observe des rapprochements entre certaines disciplines, dont la chimie, et la transformation de leur identité et de leurs frontières. Ce chapitre rend compte de la manière dont la communauté des chimistes réagit à ces transformations mais aussi comment elle perçoit les alertes sur l'environnement et sur les risques toxicologiques et éco-toxicologiques ...

  19. Synthesis and characterization of Ce doped MFI zeolite

    Energy Technology Data Exchange (ETDEWEB)

    Kalita, Banani [Department of Chemistry, Gauhati University, Guwahati, Assam 781014 (India); Talukdar, Anup K., E-mail: [Department of Chemistry, Gauhati University, Guwahati, Assam 781014 (India)


    Highlights: Black-Right-Pointing-Pointer Cerium was incorporated into the tetrahedral position of MFI zeolite structure. Black-Right-Pointing-Pointer Unit cell volume increases with an increase of Ce content in the framework of MFI. Black-Right-Pointing-Pointer A band at 310 nm in the UV-vis spectra indicates Ce incorporation in MFI structure. Black-Right-Pointing-Pointer The mass loss (%) in the region 373-423 K decreases with increase of Ce in MFI. - Abstract: Ce doped MFI (mobil five) zeolites with different Si to (Ce + Al) and different Ce to Al ratios were synthesized by a hydrothermal synthesis method. All the samples were characterized by different techniques such as X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), UV-vis diffuse reflectance spectroscopy (DRS) and scanning electron microscopy (SEM). The results showed that almost pure MFI phase was obtained in all cases with incorporation of cerium metal into the framework. The increase in unit cell parameters observed with an increase in Ce content is indicative of incorporation of Ce into the framework structure of microporous material MFI. Corroboration of the framework incorporation of Ce into the MFI zeolite structure was also obtained from the UV-vis DRS spectra by the presence of an absorption band at 280 nm. TGA and SEM of the samples provide complementary evidence for Ce incorporation into the framework MFI structure.

  20. Study of Ce-modified antibacterial 316L stainless steel

    Directory of Open Access Journals (Sweden)

    Yuan Junping


    Full Text Available 316L stainless steel is widely used for fashion jewelry, but it can carry a large number of bacteria and bring the risk of infection since the steel has no antimicrobial performance. In this paper, the effects of Ce on the antibacterial property, corrosion resistance and processability of 316L were studied by microscopic observation, thin-film adhering quantitative bacteriostasis, and electrochemical and mechanical tests. The results show that a trace of Ce can distribute uniformly in the matrix of 316L and slightly improve its corrosion resistance in artificial sweat. With an increase in Ce content, the Ce is prone to form clustering, which degrades the corrosion resistance and the processability. The Ce-containing 316L exhibits Hormesis effect against S. aureus. A small Ce addition stimulates the growth of S. aureus. As the Ce content increases, the modified 316L exhibits an improved antibacterial efficacy. The more Ce is added, the better antibacterial capability is achieved. Overall, if the 316L is modified with Ce alone, it is difficult to obtain the optimal combination of corrosion resistance, antibacterial performance and processability. In spite of that, 0.15 wt.%-0.20 wt.% Ce around is inferred to be the best trade-off.

  1. Hard probes 2006 Asilomar

    CERN Multimedia


    "The second international conference on hard and electromagnetic probes of high-energy nuclear collisions was held June 9 to 16, 2006 at the Asilomar Conference grounds in Pacific Grove, California" (photo and 1/2 page)

  2. Oxidation of Ce(III) in Foam Decontaminant by Ozone

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Chong Hun; Yoon, I. H.; Choi, W. K.; Moon, J. K.; Yang, H. B. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, J. S. [Gachon University, Seongnam (Korea, Republic of)


    A nanoparticle-based foam decontaminant is composed of a surfactant and nanoparticles for the generation and maintenance of foam, and a chemical decontamination agent made of Ce(IV) dissolved in nitric acid. Ce(IV) will be reduced to Ce(III) through the decontamination process. Oxidizing cerium(III) can be reused as a decontamination agent, Ce(IV). Oxidation treatment technology by ozone uses its strong oxidizing power. It can be regarded as an environmentally friendly process, because ozone cannot be stored and transported like other industrial gases (because it quickly decays into diatomic oxygen) and must therefore be produced on site, and used ozone can decompose immediately. The ozonation treatment of Ce(III) in foam decontaminant containing a surfactant is necessary for the effective regeneration of Ce(III). Thus, the present study was undertaken to determine the optimal conditions for ozonation treatment in the regeneration of Ce(III) into Ce(IV) in the nanoparticle-based foam decontaminant containing surfactant. This study was undertaken to determine the optimal conditions for ozonation treatment in the regeneration of Ce(III) to Ce(IV) in nanoparticle-based foam decontaminant containing a TBS surfactant. The oxidation conversion rate of Ce(III) was increased with an increase in the flow rate of the gas mixture and ozone injection amount. The oxidation time required for the 100% oxidation conversion of Ce(III) to Ce(IV) at a specific ozone injection amount can be predicted from these experimental data.

  3. The Effect of Alkali and Ce(III Ions on the Response Properties of Benzoxazine Supramolecules Prepared via Molecular Assembly

    Directory of Open Access Journals (Sweden)

    Apirat Laobuthee


    Full Text Available A series of benzoxazine monomer supramolecules with different substituted groups on their benzene ring was prepared with a Mannich reaction and characterized by FTIR, 1H-NMR and MS. The obtained products were 3,4-dihydro-3-(2’-hydroxyethylene-6-methyl-2H-benzoxazine (BM1, 3,4-dihydro-3-(2’-hydroxyethylene-6-ethyl-2H-benz-oxazine (BM2, and 3,4-dihydro-3-(2’-hydroxyethylene-6-methoxy-2H-benzoxazine (BM3. The efficiency of alkali metal ion extraction from the products was determined with Pedersen’s technique, while the complexation of the Ce(III ion was confirmed by the Job’s and the mole ratio methods. The evidence of complex formation between benzoxazine monomers and Ce(III ions was obtained with FTIR and a computational simulation. Single phase ceria (CeO2 as observed with XRD was successfully prepared by calcinating the Ce(III-benzoxazine monomer complexes at 600 °C for 2 h. In addition, the geometry of the ceria nanoparticles confirmed by TEM is spherical, with an average diameter of 10‑20 nm.

  4. Smart Phones and their Substitutes

    DEFF Research Database (Denmark)

    Bødker, Mads; Gimpel, Gregory; Hedman, Jonas


    our understanding of the role of substitutes, device content fit issues, and implications for business models by asking the question: What is an effective business model to address the relationship between user preference and the fit of the smart phone and everyday task? The field study data suggest...

  5. Sensory Substitution for Wounded Servicemembers (United States)


    Rehabilitation The IHMC Mobility Assist Exoskeleton (Figure 12) has great potential for gait rehabilitation because of its high fidelity impedance control...mobility assist exoskeleton technologies. Through sensory substitution device demonstrations, we solicited subjective situation awareness feedback...with TBI also evaluated the passive mobility assist exoskeleton , which enabled him to walk at a normal gait, unassisted, for the first time since

  6. ORIGINAL ARTICLES Mandatory substitution successful

    African Journals Online (AJOL)

    Yet private health care is the dominant vehicle for both the financing and provision of health care in the country.1 Generic substitution in this sector, therefore, has the potential to cut medication costs significantly. The Medicines and Related Substances Control Amendment. Act No. 90 of 1997 (hereinafter referred to as 'The ...

  7. No Substitute Teacher Left behind (United States)

    O'Connor, Kevin


    Schools and districts routinely recruit, retain, and support highly qualified teachers to ensure that students receive the best learning opportunities. However, even if one's school employs highly qualified full-time teachers, it is important to acknowledge that substitute teachers also have a significant impact on the education of students. One…

  8. Efficient synthesis of substituted dihydrotetraazapentacenes. (United States)

    Seillan, Claire; Brisset, Hugues; Siri, Olivier


    We describe a versatile and very efficient synthesis of previously unknown substituted 5,14-dihydro-5,7,12,14-tetraazapentacenes (DHTAPs). A structural study by NMR spectroscopy showed that the conjugated pi-system of the pentacyclic skeleton rearranges depending on the electronic effect of the substituent(s).

  9. Tax rates as strategic substitutes

    NARCIS (Netherlands)

    H. Vrijburg (Hendrik); R.A. de Mooij (Ruud)


    textabstractThis paper analytically derives conditions under which the slope of the tax-reaction function is negative in a classical tax competition model. If countries maximize welfare, a negative slope (reflecting strategic substitutability) occurs under relatively mild conditions. The strategic

  10. Potential for structural lumber substitutes (United States)

    Theodore L. Laufenberg


    The potential for substitution of structural wood composites into solid-sawn lumber markets is presented from the technological viewpoint. Technological limitations of existing composite processes and products are reviewed in the context of the present laminated veneer lumber (LVL), flakeboard, and fiber/ paper industries. The limits of mechanical property potential...

  11. Automatic extraction of ingredient's substitutes

    NARCIS (Netherlands)

    Boscarino, C.; Koenderink, N.J.J.P.; Nedovic, V; Top, J.L.


    Expert advice on how ingredients can be replaced in recipes is widely available on-line. However, these are general substitution rules, which do not take into account contextual factors such as culture, sensory perception, season, etc. We aim at tuning general rules to particular recipes. From an

  12. Increasing "Object-Substitution" Symbolic Play in Young Children With Autism Spectrum Disorders. (United States)

    Lee, Gabrielle T; Feng, Hua; Xu, Sheng; Jin, Shao-Ju


    Children with autism spectrum disorders (ASD) may not develop symbolic play skills, so such skills need to be taught specifically. We report an experiment regarding a procedure targeting "object-substitution" symbolic play skills. The "object-substitution" symbolic play behavior occurred when the child labeled a common object with the name of a substitute and used the object to perform a play action (e.g., As she put a bowl on her head, she called it a hat). A multiple probe across behaviors design was employed with five children (four boys and one girl, aged 3 to 6 years) with ASD. All children had verbal communication and demonstrated functional play and generalized imitation, but no symbolic play skills prior to the study. The instruction consisted of intraverbal training, picture prompts, and modeling of play actions. All children demonstrated object-substitution symbolic play skills after the instruction. The occurrences of response generalization were also discussed.

  13. Promoting effect of CeO 2 on cyclohexanol conversion over CeO 2 ...

    Indian Academy of Sciences (India)

    Cyclohexanol conversion reaction was carried out on these catalytic materials to investigate the effect of rare earth oxide on the activity and selectivity. It was found that CeO2 promotes the activity of ZnO without affecting the selectivity to cyclohexanone significantly. The factors such as reaction temperature and WHSV have ...

  14. Temperature quenching of yellow Ce3+ luminescence in YAG:Ce

    NARCIS (Netherlands)

    Bachmann, V.M.; Ronda, R.C.; Meijerink, A.


    Yttrium aluminum garnet (YAG) doped with Ce3+ is the phosphor of choice for the conversion of blue to yellow light in the rapidly expanding market of white light LEDs, but it is generally thought to suffer from a low luminescence quenching temperature. The luminescence quenching temperature is an

  15. Flame synthesis of nanosized Cu-Ce-O, Ni-Ce-O, and Fe-Ce-O catalysts for the water-gas shift (WGS) reaction. (United States)

    Pati, Ranjan K; Lee, Ivan C; Hou, Sicong; Akhuemonkhan, Osifo; Gaskell, Karen J; Wang, Qi; Frenkel, Anatoly I; Chu, Deryn; Salamanca-Riba, Lourdes G; Ehrman, Sheryl H


    A flame synthesis method has been used to prepare nanosized, high-surface-area Cu-Ce-O, Ni-Ce-O, and Fe-Ce-O catalysts from aqueous solutions of metal acetate precursors. The particles were formed by vaporization of the precursors followed by reaction and then gas to particle conversion. The specific surface areas of the synthesized powders ranged from 127 to 163 m(2)/g. High-resolution transmission electron microscope imaging showed that the particle diameters for the ceria materials are in the range of 3-10 nm, and a thin layer of amorphous material was observed on the surface of the particles. The presence and surface enrichment of the transition-metal oxides (CuO, NiO, and Fe(2)O(3)) on the ceria particles were detected using X-ray photoelectron spectroscopy. Electron energy-loss spectroscopic studies suggest the formation of a core-shell structure in the as-prepared particles. Extended X-ray absorption fine structure studies suggest that the dopants in all M-Ce-O systems are almost isostructural with their oxide counterparts, indicating the doping materials form separate oxide phases (CuO, Fe(2)O(3), NiO) within the host matrix (CeO(2)). Etching results confirm that most of the transition-metal oxides are present on the surface of CeO(2), easily dissolved by nitric acid. The performance of the flame-synthesized catalysts was examined toward water-gas shift (WGS) activity for fuel processing applications. The WGS activity of metal ceria catalysts decreases in the order Cu-Ce-O > Ni-Ce-O > Fe-Ce-O > CeO(2) with a feed mixture having a hydrogen to carbon monoxide (H(2)/CO) ratio of 1. There was no methane formation for these catalysts under the tested conditions.

  16. Electrochemical performance and stability of nano-particulate and bi-continuous La1-XSrXCoO3 and Ce0.9Gd0.1O1.95 composite electrodes

    DEFF Research Database (Denmark)

    Hjalmarsson, Per; Hallinder, Jonathan; Mogensen, Mogens Bjerg


    A bi-continuous porous cathode consisting of nano-particles of strontium substituted lanthanum cobaltite (LSC) covering the surface of a Ce0.9Gd0.1O1.95 (CGO10) backbone has been produced. The polarization resistance (R (P)) of this cathode was measured to similar to 35 m Omega cm(2) at 650 A deg...

  17. In Situ Spectroscopy and Mechanistic Insights into CO Oxidation on Transition-Metal-Substituted Ceria Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Elias, Joseph S.; Stoerzinger, Kelsey A.; Hong, Wesley T.; Risch, Marcel; Giordano, Livia [Dipartimento; Mansour, Azzam N. [Naval; Shao-Horn, Yang


    Herein we investigate the reaction intermediates formed during CO oxidation on copper-substituted ceria nanoparticles (Cu0.1Ce0.9O2–x) by means of in situ spectroscopic techniques and identify an activity descriptor that rationalizes a trend with other metal substitutes (M0.1Ce0.9O2–x, M = Mn, Fe, Co, Ni). In situ X-ray absorption spectroscopy (XAS) performed under catalytic conditions demonstrates that O2– transfer occurs at dispersed copper centers, which are redox active during catalysis. In situ XAS reveals a dramatic reduction at the copper centers that is fully reversible under catalytic conditions, which rationalizes the high catalytic activity of Cu0.1Ce0.9O2–x. Ambient pressure X-ray photoelectron spectroscopy (AP-XPS) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) show that CO can be oxidized to CO32– in the absence of O2. We find that CO32– desorbs as CO2 only under oxygen-rich conditions when the oxygen vacancy is filled by the dissociative adsorption of O2. These data, along with kinetic analyses, lend support to a mechanism in which the breaking of copper–oxygen bonds is rate-determining under oxygen-rich conditions, while refilling the resulting oxygen vacancy is rate-determining under oxygen-lean conditions. On the basis of these observations and density functional calculations, we introduce the computed oxygen vacancy formation energy (Evac) as an activity descriptor for substituted ceria materials and demonstrate that Evac successfully rationalizes the trend in the activities of M0.1Ce0.9O2–x catalysts that spans three orders of magnitude. The applicability of Evac as a useful design descriptor is demonstrated by the catalytic performance of the ternary oxide Cu0.1La0.1Ce0.8O2–x, which has an apparent activation energy rivaling those of state-of-the-art Au/TiO2 materials. Thus, we suggest that cost-effective catalysts for CO oxidation can be rationally designed by judicious choice of substituting

  18. Effect of manganese doping on the electronic structure and optical properties of Ce2Fe17- x Mn x ( x = 0, 1, 2) (United States)

    Lukoyanov, Alexey V.; Knyazev, Yurii V.; Kuz'min, Yurii I.; Kuchin, Anatoliy G.


    In this paper we investigate the electronic structure and optical properties of the Ce2Fe17-xMnx (x = 0, 1, 2) intermetallic compounds and their change with the Mn-concentration growth within theoretical ab initio calculations. From these results we plot and compare experimental and theoretical optical conductivity utilizing interband transitions to interpret the experimental curve. To estimate the influence of manganese substitutions on the 3d sublattice, exchange Fe/Mn interaction parameters were computed and analysed. It was found that for the Mn substitutional impurity in the dumbbell positions the dominating ferromagnetic exchange interaction becomes the antiferromagnetic one favoring noncollinear magnetic ordering which was found in Ce2Fe17-xMnx at low temperatures.

  19. Magnetic and optical properties of electrospun hollow nanofibers of SnO2 doped with Ce-ion (United States)

    Mohanapriya, P.; Pradeepkumar, R.; Victor Jaya, N.; Natarajan, T. S.


    Cerium doped SnO2 hollow nanofibers were synthesized by electrospinning. High resolution scanning electron microscope (HRSEM) and transmission electron microscopy (TEM) analysis showed hollow nanofibers with diameters around ˜200 nm. The optimized substitution of Ce ion into SnO2 lattices happened above 6 mol. % doping as confirmed by Powder X-ray diffraction (XRD) studies. Optical band gap was decreased by the doping confirming the direct energy transfer between f-electrons of rare earth ion and the SnO2 conduction or valence band. The compound also exhibited room temperature ferromagnetism with the saturation magnetization of 19 × 10-5 emu/g at 6 mol. %. This study demonstrates the Ce doped SnO2 hollow nanofibers for applications in magneto-optoelectronic devices.

  20. Temperature Dependent Magnetoresistance of CeCu2Si2 up to 60 T [Proposal: P14728

    Energy Technology Data Exchange (ETDEWEB)

    Stritzinger, Laurel Elaine Winter [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lai, Y. [Florida State Univ., Tallahassee, FL (United States); Mcdonald, Ross David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baumbach, R. E. [Florida State Univ., Tallahassee, FL (United States)


    We recently investigated the chemical substitution series CeCu2Si2-xPx, for x = 0, 0.01, and 0.14, using a contactless tunnel diode oscillator technique. These measurements revealed previously unreported Shubnikov-de Haas oscillations above 45 T with an unusual temperature dependence that could potentially be explained by a high magnetic field transition. To investigate this possible transition, magnetoresistance measurements were desired. However, initial magnetoresistance measurements on CeCu2Si2 showed poor signal-to-noise due to the small value of the sample's resistivity. To overcome this obstacle, we performed micro-structuring of a single crystal specimen to increase the sample's resistance.

  1. Huygens probe on target (United States)


    In October 1997, a Titan/Centaur rocket lifting-off from Cape Canaveral will boost the spacecraft into a 6.7 year trajectory to reach Saturn. The trajectory will use two swing-bys of Venus in April 1998 and June 1999, followed by an Earth swing-by in August 1999 and a Jupiter swing-by in December 2000 to boost speed and reach Saturn in July 2004. A few months after going into orbit around Saturn, the Cassini spacecraft will release the Huygens probe for its descent through the atmosphere of Titan, the largest satellite of Saturn. The Huygens probe will measure the abundance of elements and compounds in Titan's atmosphere, the distribution of trace gases and aerosols, winds, temperature, pressure and surface state and its composition. A multi-spectral camera on the probe will provide images of the landscape of Titan. Titan is a unique planetary body in the solar system. It has an atmosphere which is primarily nitrogen. but is also rich in hydrocarbons. Due to the vast distance of the Saturnian system from the Sun, this atmosphere is at a very low temperature, thus greatly slowing down all the chemical processes. A study of this atmosphere will throw light on the development of our own atmosphere and contribute to our understanding of the origins of life on Earth. The Huygens probe is being developed by ESA with Aerospatiale (F) as the industrial prime contractor. Since the start of the programme in April 1990, very good progress has been made in design and hardware development. The entry into the Titan atmosphere will result in a very high surface temperature on the probe, generated as it decelerates due to the friction of the upper atmospheric layers. After the probe has slowed down sufficiently, a system of parachutes ensures a slow descent to the surface of Titan in approximately two and a half hours. The scientific measurements can only begin after the heat shield, which is needed to protect the probe during the high temperature entry phase, has been ejected

  2. 40 CFR 721.981 - Substituted naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex. (United States)


    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL... uses subject to reporting. (1) The chemical substance identified generically as a substituted... subpart A of this part apply to this section except as modified by this paragraph. (1) Recordkeeping...

  3. Model for resonant plasma probe.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin; Johnson, William Arthur; Hebner, Gregory Albert; Jorgenson, Roy E.; Coats, Rebecca Sue


    This report constructs simple circuit models for a hairpin shaped resonant plasma probe. Effects of the plasma sheath region surrounding the wires making up the probe are determined. Electromagnetic simulations of the probe are compared to the circuit model results. The perturbing effects of the disc cavity in which the probe operates are also found.

  4. Inverted opal luminescent Ce-doped silica glasses

    Directory of Open Access Journals (Sweden)

    R. Scotti


    Full Text Available Inverted opal Ce-doped silica glasses (Ce : Si molar ratio 1 ⋅ 10−3 were prepared by a sol-gel method using opals of latex microspheres as templates. The rare earth is homogeneously dispersed in silica host matrix, as evidenced by the absence of segregated CeO2, instead present in monolithic Ce-doped SG with the same cerium content. This suggests that the nanometric dimensions of bridges and junctions of the host matrix in the inverted opal structures favor the RE distribution avoiding the possible segregation of CeO2.

  5. The infinite line pressure probe (United States)

    Englund, D. R.; Richards, W. B.


    The infinite line pressure probe provides a means for measuring high frequency fluctuating pressures in difficult environments. A properly designed infinite line probe does not resonate; thus its frequency response is not limited by acoustic resonance in the probe tubing, as in conventional probes. The characteristics of infinite line pressure probes are reviewed and some applications in turbine engine research are described. A probe with a flat-oval cross section, permitting a constant-impedance pressure transducer installation, is described. Techniques for predicting the frequency response of probes with both circular and flat-oval cross sections are also cited.

  6. Estimation of Ce 4f-5d Interaction by Analysis of Partial Fluorescence Yield at the Ce L3 Edge of CeO2 (United States)

    Tonai, Hironori; Sasabe, Norimasa; Uozumi, Takayuki; Kawamura, Naomi; Mizumaki, Masaichiro


    Partial fluorescence yield (PFY) spectroscopy, which corresponds to a high-resolution version of the X-ray absorption spectroscopy (XAS), is experimentally performed at the Ce L3 edge of CeO2, and the result is theoretically analyzed using an impurity Anderson model (IAM). In order to estimate the Ce 4f-5d interaction Ufd, we employ a semi-empirical IAM framework based on the local density approximation+U method; Slater-Koster parameters describing the valence of CeO2 are estimated by band mapping within the linear combination of atomic orbitals scheme, and the resulting realistic valence structure is considered in the IAM analysis. The global structure of the PFY-XAS result, which consists of the Ce 2p3/2 → 5d dipole transition and the Ce 2p3/2 → 4f quadrupole transition, is excellently reproduced by the calculation. The Ufd value is estimated to be 3.0 eV. We emphasize that the sensitivity of PFY-XAS to Ufd makes it a good ruler for obtaining the Ufd values of Ce compounds.

  7. Tuning of magnetic properties and Kondo effect by Cu concentration in Ce(Pd sub 1 sub - sub x Cu sub x) sub 2 Al sub 3

    CERN Document Server

    Sun, P; Huo, D; Kuwai, T; Lu, Q


    The electrical resistivity, magnetic susceptibility and specific heat measurements were performed on Ce(Pd sub 1 sub - sub x Cu sub x) sub 2 Al sub 3 (x = 0.0-0.7) system to investigate the effects induced by Cu substitution in the heavy fermion compound CePd sub 2 Al sub 3. A dramatic evolution of the magnetic properties was observed with the substitution of Pd by Cu: (1) a small amount of Cu (x < 0.1) in CePd sub 2 Al sub 3 leads to a rapid decrease of the antiferromagnetic transition temperature T sub N; passing through a crossover region without a long-range magnetic order, a ferromagnetic-like state, which reveals an enhanced magnetic susceptibility and a distinct peak in the specific heat curve at low temperatures, occurs around x = 0.1-0.4; (3) by furthering the substitution through a second crossover region, however, the antiferromagnetic ordering is recovered close to x = 0.5 - 0.7. A decrease tendency of the Kondo temperature T sub K with increasing x is derived from the analysis on the specific ...

  8. Study of the crystal field in CeF3 and CeF3:Pr3+

    Directory of Open Access Journals (Sweden)

    Shafikov F.F., Savinkov A.V., Tagirov M.S.


    Full Text Available The crystal field analysis based on calculations in the framework of the semi phenomenological exchange charge model was carried out. The set of crystal field parameters for Ce3+ and Pr3+ ions in the matrix CeF3 related to the crystallographic system of coordinates has been obtained and used to reproduce satisfactory the crystal field energies of Ce3+ and Pr3+ ions.

  9. Currency Substitution and Financial Innovation.


    Pablo E. Guidotti


    This paper explores the domestic effects as well as the international transmission of financial innovation. The analysis is carried out in a cash-in-advance model with two currencies and tw o goods in which income velocity is variable because of inventory-type considerations in the determination of the demand for money. The discussion emphasizes the role of currency substitution, which occur s through the interaction between the two monies in affecting the tota l amount of time devoted to tra...

  10. (nitro substituted-phenyl)-hydrazonomethyl

    Indian Academy of Sciences (India)

    5c. Et. CH3 NO2. NO2. 5d. Me H. NO2. NO2. 5e. Et. Br. H. NO2. Scheme 1. Synthesis of receptors 5a–5e. Reagents and conditions: (i) TFA, H2O, room temperature, 15 min;. (ii) DMF-POCl3, 0. ◦. C, 2.5–3 h; (iii) substituted phenyl hydrazine derivative, ethanol, reflux, 1–2 h. The anion binding characteristics of receptors 5a– ...

  11. Detecting Single-Nucleotide Substitutions Induced by Genome Editing. (United States)

    Miyaoka, Yuichiro; Chan, Amanda H; Conklin, Bruce R


    The detection of genome editing is critical in evaluating genome-editing tools or conditions, but it is not an easy task to detect genome-editing events-especially single-nucleotide substitutions-without a surrogate marker. Here we introduce a procedure that significantly contributes to the advancement of genome-editing technologies. It uses droplet digital polymerase chain reaction (ddPCR) and allele-specific hydrolysis probes to detect single-nucleotide substitutions generated by genome editing (via homology-directed repair, or HDR). HDR events that introduce substitutions using donor DNA are generally infrequent, even with genome-editing tools, and the outcome is only one base pair difference in 3 billion base pairs of the human genome. This task is particularly difficult in induced pluripotent stem (iPS) cells, in which editing events can be very rare. Therefore, the technological advances described here have implications for therapeutic genome editing and experimental approaches to disease modeling with iPS cells. © 2016 Cold Spring Harbor Laboratory Press.

  12. Dependence of the Ce(iii)/Ce(iv) ratio on intracellular localization in ceria nanoparticles internalized by human cells

    KAUST Repository

    Ferraro, Daniela


    CeO2 nanoparticles (CNPs) have been investigated as promising antioxidant agents with significant activity in the therapy of diseases involving free radicals or oxidative stress. However, the exact mechanism responsible for CNP activity has not been completely elucidated. In particular, in situ evidence of modification of the oxidative state of CNPs in human cells and their evolution during cell internalization and subsequent intracellular distribution has never been presented. In this study we investigated modification of the Ce(iii)/Ce(iv) ratio following internalization in human cells by X-ray absorption near edge spectroscopy (XANES). From this analysis on cell pellets, we observed that CNPs incubated for 24 h showed a significant increase in Ce(iii). By coupling on individual cells synchrotron micro-X-ray fluorescence (μXRF) with micro-XANES (μXANES) we demonstrated that the Ce(iii)/Ce(iv) ratio is also dependent on CNP intracellular localization. The regions with the highest CNP concentrations, suggested to be endolysosomes by transmission electron microscopy, were characterized by Ce atoms in the Ce(iv) oxidation state, while a higher Ce(iii) content was observed in regions surrounding these areas. These observations suggest that the interaction of CNPs with cells involves a complex mechanism in which different cellular areas play different roles.

  13. Substituted Indoleacetic Acids Tested in Tissue Cultures

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen


    Monochloro substituted IAA inhibited shoot induction in tobacco tissue cultures about as much as IAA. Dichloro substituted IAA inhibited shoot formation less. Other substituted IAA except 5-fluoro- and 5-bromoindole-3-acetic acid were less active than IAA. Callus growth was quite variable...

  14. 24 CFR 234.256 - Substitute mortgagors. (United States)


    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Substitute mortgagors. 234.256... Substitute mortgagors. (a) Selling mortgagor. The requirements for the selling mortgagor are set forth in... Commissioner's approval of a substitute mortgagor only if the mortgage executed by the original mortgagor met...

  15. 21 CFR 882.5910 - Dura substitute. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dura substitute. 882.5910 Section 882.5910 Food... DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5910 Dura substitute. (a) Identification. A dura substitute is a sheet or material that is used to repair the dura mater (the membrane...

  16. 24 CFR 235.206 - Substitute mortgagors. (United States)


    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Substitute mortgagors. 235.206... and Obligations-Homes for Lower Income Families § 235.206 Substitute mortgagors. (a) Selling mortgagor... if it obtains the Commissioner's approval of a substitute mortgagor, as provided under this section...

  17. 37 CFR 1.125 - Substitute specification. (United States)


    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Substitute specification. 1... § 1.125 Substitute specification. (a) If the number or nature of the amendments or the legibility of... thereof, be rewritten. (b) Subject to § 1.312, a substitute specification, excluding the claims, may be...

  18. 24 CFR 203.258 - Substitute mortgagors. (United States)


    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Substitute mortgagors. 203.258... § 203.258 Substitute mortgagors. (a) Selling mortgagor. Except as provided in paragraph (d) of this..., only if it obtains the Commissioner's approval of a substitute mortgagor, as provided by this section...

  19. 24 CFR 220.253 - Substitute mortgagors. (United States)


    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Substitute mortgagors. 220.253... Contract Rights and Obligations-Homes § 220.253 Substitute mortgagors. (a) Selling mortgagor. The mortgagee... the Commissioner's approval of a substitute mortgagor, as provided by this section. (b) Purchasing...

  20. 24 CFR 221.252 - Substitute mortgagors. (United States)


    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Substitute mortgagors. 221.252... Cost Homes § 221.252 Substitute mortgagors. (a) Selling mortgagor. The mortgagee may effect the release... approval of a substitute mortgagor, as provided by this section. (b) Purchasing mortgagor. The Commissioner...

  1. 40 CFR 192.42 - Substitute provisions. (United States)


    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Substitute provisions. 192.42 Section 192.42 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION PROTECTION... § 192.42 Substitute provisions. The regulatory agency may, with the concurrence of EPA, substitute for...

  2. 40 CFR 721.323 - Substituted acrylamide. (United States)


    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted acrylamide. 721.323... Substances § 721.323 Substituted acrylamide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance generically identified as substituted acrylamide (PMN P-90-1687) is...

  3. Lifetime measurements in {sup 133}Ce

    Energy Technology Data Exchange (ETDEWEB)

    Emediato, L.G.; Rao, M.N.; Medina, N.H.; Seale, W.A.; Botelho, S.; Ribas, R.V.; Oliveira, J.R.; Cybulska, E.W.; Espinoza-Quinones, F.R.; Guimaraes, V.; Rizzutto, M.A.; Acquadro, J.C. [Laboratorio Pelletron, Departamento de Fisica Nuclear, Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil)


    Lifetimes of low-lying levels in the one- and three-quasiparticle bands in {sup 133}Ce have been measured using the recoil-distance Doppler-shift technique. The E2 transition strengths extracted for the negative parity yrast states are well described by the triaxial-rotor-plus-quasiparticle and the geometrical models, but the interacting-boson-plus-fermion predictions are too small by about a factor of 3. The B(M1) values extracted for the levels in the positive parity three-quasiparticle band are consistent with the previous {nu}h{sub 11/2}{circle_times}{pi}h{sub 11/2}{circle_times}{pi}g{sub 7/2} configuration assignment to this band. {copyright} {ital 1997} {ital The American Physical Society}

  4. Spectrofluorimetric determination of total free thiols based on formation of complexes of Ce(III) with disulfide bonds

    Energy Technology Data Exchange (ETDEWEB)

    Han Guocheng; Peng Yong; Hao Yuanqiang [College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083 (China); Liu Younian, E-mail: [College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083 (China); Zhou Feimeng, E-mail: [College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083 (China); Department of Chemistry and Biochemistry, California State University, Los Angeles, Los Angeles, CA 90032 (United States)


    A simple, rapid, and sensitive determination of total free thiol groups in biological samples using cerium (IV) as a fluorescence probe is reported. The protocol is based on the oxidation of thiols by Ce(IV) and the formation the Ce(III) disulfide complex, which gives a fluorescence enhancement of Ce(III) at 352 nm. Using glutathione (GSH) and cysteine as model compounds, incubation with Ce(IV) at 25 {sup o}C for 6 min results in fluorescence, whose intensity is proportional to the thiol concentration in the range of 1.00-160 nM. The detection limits for GSH and cysteine are 0.05 and 0.08 nM, respectively. Other common metal ions and amino acids have little interference to the thiol detection. Cu(II) was used as a fluorescence quencher to eliminate potential interference from tryptophan. The method has been successfully applied to assays of free thiol contents in pig liver tissue samples, with a RSD lower than 2.5% and recovery between 100.6% and 102.3%.

  5. Influence of surface functionalization on structural and photo-luminescence properties of CeF{sub 3}:Tb nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ansari, Anees A., E-mail:


    Graphical abstract: We designed highly aqueous dispersible CeF{sub 3}:Tb@LaF{sub 3}@SiO{sub 2} nanoparticles. The epitaxial growth of inert LaF{sub 3} shell and further amorphous silica, respectively, enhanced their optical and luminescence properties, which is highly usable for luminescent biolabeling, and optical bio-probe etc. - Abstract: Highly luminescent and aqueous soluble CeF{sub 3}:Tb (core),CeF{sub 3}:Tb@LaF{sub 3}(core/shell) and CeF{sub 3}:Tb@LaF{sub 3}@ SiO{sub 2} (core/shell/Si) nanoparticles(NPs) with mean particle size 12 nm were prepared by co-precipitation method at low temperature. X-ray diffraction pattern verified the phase purity, high crystallinity of hexagonal structure. The TEM image and SAED pattern revealed the single phase polycrystalline nature, well-dispersed irregular shaped hexagonal structure. FTIR spectra show the characteristic infrared peaks of silica, it suggests the successful silica surface coating around the core/shell NPs. The excitation and emission intensity of core/shell NPs were remarkably increased then their counterpart core NPs. It implies that a significant amount of nonradiative transition centers existing on the surface of core NPs has been eliminated due to the formation of passivated LaF{sub 3} layer. The silica surface modification over the core/shell NPs strikingly enhanced the solubility character in an aqueous environment.

  6. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted... (United States)


    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane...

  7. Traducerea: între ce se poate traduce și ce trebuie tradus

    Directory of Open Access Journals (Sweden)

    Magda Jeanrenaud


    Full Text Available Pornind de la o tulburătoare interpretare a lui Jacques Derrida, studiul de față își propune să investigheze și încearcă să explice blocajul ce intervine în versiunile englezești, franceze și românești (semnate de Antoine Berman, Alexis Nouss, Steven Rendall, Catrinel Pleșu etc. ale celebrului text al lui Walter Benjamin, Die Aufgabe des Übersetzers, atunci cînd traducătorii transpun în cele trei limbi țintă cele două citate cuprinse în acesta: un citat din Mallarmé, lăsat netradus de Benjamin însuși, și un altul, din Pannwitz. Într-un fel sau altul, ambele citate au o formă discursivă ce lasă să se întrevadă o sintaxă ce se abate deliberat de la normă, ca și cum ar fi deja niște „traduceri”. Analiza mai pune în evidență și comportamentul (cumva o dominantă a psihologiei traducătorilor? celor ce au transpus textul benjaminian, comportament marcat de obsesia lizibilității văzută ca o trăsătură congenitală a oricărei traduceri, chiar și atunci cînd textul original nu tinde spre aceasta. De unde și dilema, dureroasă, legată de spinoasa chestiune a intenționalității textului (nu doar de tradus...

  8. Purification of hydrogen from carbon monoxide for fuel cell application over modified mesoporous CuO-CeO2 catalysts

    KAUST Repository

    Li, Jing


    Selective oxidation of CO in H2-rich streams was carried out over a series of CuO-CeO2 catalysts doped by different transition metals (Mn, Fe, Ni, Ti, Co and Cr). The effect of the dopants on the structure and catalytic properties of CuO-CeO2 catalysts was investigated by N2 adsorption/desorption, X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), Raman spectra and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) techniques. The results show that the addition of Mn and Fe plays a beneficial role in extending the low-temperature catalytic activity of CuO-CeO2 catalysts, whereas the introduction of Cr and Co leads to a negative effect on the catalytic activity and resistance against CO2 and H2O. The superior catalytic performance of CuO-CeO2 catalysts with Mn and Fe doping originates from the enhanced interaction between copper and ceria, owing to the formation of more Cu+ and oxygen vacancies in the solid solution framework. While the poor catalytic activity of the Co doped counterpart is mainly ascribed to the substitution of introduced cobalt ions for copper ions in ceria lattice, resulting in the segregation of copper ions from the ceria lattice and the consequent aggregation of copper species on the ceria surface. The doping of Cr into CuO-CeO2 structure remarkably weakens the interaction between copper and ceria, which decreases the reducibility of copper species and inhibits the formation of Cu+. It accounts for the lowest catalytic activity. © 2011 Elsevier B.V.

  9. Projected shell model study of neutron- deficient 122Ce

    Indian Academy of Sciences (India)

    Recently, Smith et al [1] have communicated the existence of neutron-deficient 122Ce and its excited states have been reported up to spin 14¯h. The band has been as- signed to 122Ce by detecting γ-rays in coincidence with evaporated charged particles and neutrons. The nucleus is believed to have large ground state ...

  10. Hard Probes at ATLAS

    CERN Document Server

    Citron, Z; The ATLAS collaboration


    The ATLAS collaboration has measured several hard probe observables in Pb+Pb and p+Pb collisions at the LHC. These measurements include jets which show modification in the hot dense medium of heavy ion collisions as well as color neutral electro-weak bosons. Together, they elucidate the nature of heavy ion collisions.

  11. The solar probe antenna (United States)

    Imbriale, W. A.; Randolph, J. E.; Embuido, E.


    This paper details the design of the antenna intended for use on the Solar Probe Mission. The antenna consists of a carbon-carbon reflector jointly used as the antenna and thermal shield and helical feed using tungsten wire and ceramic matrix composite (CMC) materials for the back plate, coaxial cable waveguide. A complete prototype feed assembly was fabricated and tested.

  12. Probing the Solar Interior

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 3. Probing the Solar Interior Hearing the Heartbeats of the Sun. Ashok Ambastha. General Article Volume 3 Issue 3 March 1998 pp 18-31. Fulltext. Click here to view fulltext PDF. Permanent link:

  13. Mobile Probing Kit

    DEFF Research Database (Denmark)

    Larsen, Jakob Eg; Sørensen, Lene Tolstrup; Sørensen, J.K.


    Mobile Probing Kit is a low tech and low cost methodology for obtaining inspiration and insights into user needs, requirements and ideas in the early phases of a system's development process. The methodology is developed to identify user needs, requirements and ideas among knowledge workers...

  14. Terahertz scanning probe microscope

    NARCIS (Netherlands)

    Klapwijk, T.M.


    The invention provides aterahertz scanning probe microscope setup comprising (i) a terahertz radiation source configured to generate terahertz radiation; (ii) a terahertz lens configured to receive at least part of the terahertz radiation from the terahertz radiation source; (iii) a cantilever unit

  15. One-Probe Search

    DEFF Research Database (Denmark)

    Östlin, Anna; Pagh, Rasmus


    We consider dictionaries that perform lookups by probing a single word of memory, knowing only the size of the data structure. We describe a randomized dictionary where a lookup returns the correct answer with probability 1 - e, and otherwise returns don't know. The lookup procedure uses an expan...

  16. Probing the Solar System (United States)

    Wilkinson, John


    Humans have always had the vision to one day live on other planets. This vision existed even before the first person was put into orbit. Since the early space missions of putting humans into orbit around Earth, many advances have been made in space technology. We have now sent many space probes deep into the Solar system to explore the planets and…

  17. Properties of LuAP: CE scintillator containing intentional impurities

    CERN Document Server

    Petrosyan, A G; Ovanesyan, K; Lecoq, Paul; Auffray, Etiennette; Trummer, Julia; Kronberger, Matthias; Pédrini, C; Dujardin, C; Anfre, P


    Single crystals of LuAP:Ce and LuYAP(Lu*70%):Ce co-doped with tetravalent (Hf and Zr) and pentavalent (Ta) ions were grown from melts by the Bridgman process. Underlying absorption, slope of the optical edge and transmission in the range of emission were compared to those of LuAP:Ce crystals. Absorption coefficients at 260 nm less than 2 cm−1 have been recorded in LuAP:Ce crystals containing tetravalent ions that are lower than the corresponding figures (5–6 cm−1) measured in undoped LuAP. At high concentrations of added impurities, despite of suppression of the parasitic underlying absorption below 300 nm, the slope of the optical edge and transmission in the range of emission are seriously damaged. Scintillation parameters of crystals with added impurities are compared to those of LuAP:Ce.

  18. Commissioning the HTCondor-CE for the Open Science Grid (United States)

    Bockelman, B.; Cartwright, T.; Frey, J.; Fajardo, E. M.; Lin, B.; Selmeci, M.; Tannenbaum, T.; Zvada, M.


    The HTCondor-CE is the next-generation gateway software for the Open Science Grid (OSG). This is responsible for providing a network service which authorizes remote users and provides a resource provisioning service (other well-known gateways include Globus GRAM, CREAM, Arc-CE, and Openstacks Nova). Based on the venerable HTCondor software, this new CE is simply a highly-specialized configuration of HTCondor. It was developed and adopted to provide the OSG with a more flexible, scalable, and easier-to-manage gateway software. Further, the focus of the HTCondor-CE is not job submission (as in GRAM or CREAM) but resource provisioning. This software does not exist in a vacuum: to deploy this gateway across the OSG, we had to integrate it with the CE configuration, deploy a corresponding information service, coordinate with sites, and overhaul our documentation.


    Directory of Open Access Journals (Sweden)

    Nazmi EKREN


    Full Text Available Due to the reason for rapidly developing technology, increasing competition medium, and awareness of the consumers, nowadays, the exigency of production with good quality has gained more and more significance. Certification of the quality and safety of the products to the consumers is compulsory in terms of producers. There are some documents to certify safety of the products. One of them is CE certificate. In this paper, basic information about CE mark is given and CE standards and tests required for electrical household appliances are mentioned. As an application, one of an electrical household appliance, toaster grill is treated and examined. To obtain CE certificate for toaster grill, required tests are made according to EN60335-2-9 and CE certificate is obtained.

  20. CePdAl. A frustrated Kondo lattice at a quantum critical point

    Energy Technology Data Exchange (ETDEWEB)

    Fritsch, Veronika [EP 6, Electronic Correlations and Magnetism, University of Augsburg (Germany); Karlsruhe Institute of Technology (Germany); Sakai, Akito; Gegenwart, Philipp [EP 6, Electronic Correlations and Magnetism, University of Augsburg (Germany); Huesges, Zita; Lucas, Stefan; Stockert, Oliver [Max Planck Institute for Chemical Physics of Solids, Dresden (Germany); Kittler, Wolfram; Taubenheim, Christian; Grube, Kai; Loehneysen, Hilbert von [Karlsruhe Institute of Technology (Germany); Huang, Chien-Lung [Karlsruhe Institute of Technology (Germany); Max Planck Institute for Chemical Physics of Solids, Dresden (Germany)


    CePdAl is one of the rare frustrated Kondo lattice systems that can be tuned across a quantum critical point (QCP) by means of chemical pressure, i. e., the substitution of Pd by Ni. Magnetic frustration and Kondo effect are antithetic phenomena: The Kondo effect with the incipient delocalization of the magnetic moments, is not beneficial for the formation of a frustrated state. On the other hand, magnetic frustrated exchange interactions between the local moments can result in a breakdown of Kondo screening. Furthermore, the fate of frustration is unclear when approaching the QCP, since there is no simple observable to quantify the degree of frustration. We present thermodynamic and neutron scattering experiments on CePd{sub 1-x}Ni{sub x}Al close to the critical concentration x ∼0.14. Our experiments indicate that even at the QCP magnetic frustration is still present, opening the perspective to find new universality classes at such a quantum phase transition.

  1. Mechanosensitive membrane probes. (United States)

    Dal Molin, Marta; Verolet, Quentin; Soleimanpour, Saeideh; Matile, Stefan


    This article assembles pertinent insights behind the concept of planarizable push-pull probes. As a response to the planarization of their polarized ground state, a red shift of their excitation maximum is expected to report on either the disorder, the tension, or the potential of biomembranes. The combination of chromophore planarization and polarization contributes to various, usually more complex processes in nature. Examples include the color change of crabs or lobsters during cooking or the chemistry of vision, particularly color vision. The summary of lessons from nature is followed by an overview of mechanosensitive organic materials. Although often twisted and sometimes also polarized, their change of color under pressure usually originates from changes in their crystal packing. Intriguing exceptions include the planarization of several elegantly twisted phenylethynyl oligomers and polymers. Also mechanosensitive probes in plastics usually respond to stretching by disassembly. True ground-state planarization in response to molecular recognition is best exemplified with the binding of thoughtfully twisted cationic polythiophenes to single- and double-stranded oligonucleotides. Molecular rotors, en vogue as viscosity sensors in cells, operate by deplanarization of the first excited state. Pertinent recent examples are described, focusing on λ-ratiometry and intracellular targeting. Complementary to planarization of the ground state with twisted push-pull probes, molecular rotors report on environmental changes with quenching or shifts in emission rather than absorption. The labeling of mechanosensitive channels is discussed as a bioengineering approach to bypass the challenge to create molecular mechanosensitivity and use biological systems instead to sense membrane tension. With planarizable push-pull probes, this challenge is met not with twistome screening, but with "fluorescent flippers," a new concept to insert large and bright monomers into oligomeric

  2. Electronic and magnetic states of Ce 4f electrons in CeRh{sub 3}B{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Imada, S. [Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531 (Japan)], E-mail:; Yamasaki, A. [Faculty of Science and Engineering, Konan University, Kobe 658-8501 (Japan); Tsunekawa, M. [Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531 (Japan); Higashiya, A. [SPring-8/RIKEN 1-1-1 Kouto, Mikazuki, Sayo, Hyogo 679-5148 (Japan); Sekiyama, A. [Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531 (Japan); Sugawara, H. [Faculty of Integrated Arts and Sciences, Tokushima University, Tokushima 770-8502 (Japan); Sato, H. [Graduate School of Science, Tokyo Metropolitan University, Hachioji 192-0397 (Japan); Suga, S. [Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531 (Japan)


    CeRh{sub 3}B{sub 2} is a ferromagnet with exceptionally high Curie temperature (T{sub C}=115 K) among the Ce compounds with no transition metal magnetic element. Magnetic circular dichroism of soft X-ray photoabsorption (XMCD) has revealed that the orbital angular momentum of Ce 4f electron is quenched to some extent. In addition, preferential occupation of the Ce 4f orbital pointing to the c-axis has been confirmed by the soft X-ray photoabsorption measurements with different geometries. On the other hand, resonant photoemission around the Ce 3d {yields} 4f photoabsorption edge has been adopted in order to disentangle the Ce 4f and Rh 4d components in the valence band. The Rh 4d spectrum is qualitatively consistent with the band structure calculation. Although the Ce 4f spectrum has a peak near the Fermi level, the spectral shape is qualitatively different from that of the typical Kondo materials and is rather similar to that of itinerant Ce 4f systems.

  3. The mixed-valence state of Ce in the hexagonal CeNi sub 4 B compound

    CERN Document Server

    Tolinski, T; Pugaczowa-Michalska, M; Chelkowska, G


    Measurements of the magnetic susceptibility chi, x-ray photoemission spectra (XPS), electrical resistivity rho and electronic structure calculations for CeNi sub 4 B are reported. In the paramagnetic region, CeNi sub 4 B follows the Curie-Weiss law with mu sub e sub f sub f = 0.52 mu sub B /fu and theta -10.7 K. The effective magnetic moment is lower than the free Ce sup 3 sup + -ion value. The Ce(3d) XPS spectra have confirmed the mixed-valence state of Ce ions in CeNi sub 4 B. The f occupancy, n sub f , and the coupling DELTA between the f level and the conduction states were derived to be about 0.83 and 85 meV, respectively. Both susceptibility data and XPS spectra show that Ce ions in CeNi sub 4 B are in the intermediate-valence state. At low temperatures (below 12 K), the magnetic contribution to the electrical resistivity reveals a logarithmic slope characteristic of Kondo-like systems.

  4. CE-SSCP and CE-FLA, simple and high-throughput alternatives for fungal diversity studies. (United States)

    Zinger, Lucie; Gury, Jérôme; Alibeu, Olivier; Rioux, Delphine; Gielly, Ludovic; Sage, Lucile; Pompanon, François; Geremia, Roberto A


    Fungal communities are key components of soil, but the study of their ecological significance is limited by a lack of appropriated methods. For instance, the assessment of fungi occurrence and spatio-temporal variation in soil requires the analysis of a large number of samples. The molecular signature methods provide a useful tool to monitor these microbial communities and can be easily adapted to capillary electrophoresis (CE) allowing high-throughput studies. Here we assess the suitability of CE-FLA (Fragment Length Polymorphism, denaturing conditions) and CE-SSCP (Single-Stranded Conformation Polymorphism, native conditions) applied to environmental studies since they require a short molecular marker and no post-PCR treatments. We amplified the ITS1 region from 22 fungal strains isolated from an alpine ecosystem and from total genomic DNA of alpine and infiltration basin soils. The CE-FLA and CE-SSCP separated 17 and 15 peaks respectively from a mixture of 19 strains. For the alpine soil-metagenomic DNA, the FLA displayed more peaks than the SSCP and the converse result was found for infiltration basin sediments. We concluded that CE-FLA and CE-SSCP of ITS1 region provided complementary information. In order to improve CE-SSCP sensitivity, we tested its resolution according to migration temperature and found 32 degrees C to be optimal. Because of their simplicity, quickness and reproducibility, we found that these two methods were promising for high-throughput studies of soil fungal communities.

  5. On the residual resistivity of CeAl 2 and CeCu 6. implications for the Kondo lattice model (United States)

    Barbara, B.; Beille, J.; Cheiato, B.; Najib, A.; Zemirli, S.


    High pressure resistivity experiments performed on CeAl 2 and CeCu 6 show that the residual resistivity ϱ 0 intervening in ϱ=ϱ 0[1+α( {T}/{T c}) 2-…] is a function of the characteristic temperature Tc. A scaling form is proposed to fit the low temperature resistivity of heavy fermions.

  6. Prototype of a single probe Compton camera for laparoscopic surgery (United States)

    Koyama, A.; Nakamura, Y.; Shimazoe, K.; Takahashi, H.; Sakuma, I.


    Image-guided surgery (IGS) is performed using a real-time surgery navigation system with three-dimensional (3D) position tracking of surgical tools. IGS is fast becoming an important technology for high-precision laparoscopic surgeries, in which the field of view is limited. In particular, recent developments in intraoperative imaging using radioactive biomarkers may enable advanced IGS for supporting malignant tumor removal surgery. In this light, we develop a novel intraoperative probe with a Compton camera and a position tracking system for performing real-time radiation-guided surgery. A prototype probe consisting of Ce :Gd3 Al2 Ga3 O12 (GAGG) crystals and silicon photomultipliers was fabricated, and its reconstruction algorithm was optimized to enable real-time position tracking. The results demonstrated the visualization capability of the radiation source with ARM = ∼ 22.1 ° and the effectiveness of the proposed system.

  7. EDITORIAL: Probing the nanoworld Probing the nanoworld (United States)

    Miles, Mervyn


    In nanotechnology, it is the unique properties arising from nanometre-scale structures that lead not only to their technological importance but also to a better understanding of the underlying science. Over the last twenty years, material properties at the nanoscale have been dominated by the properties of carbon in the form of the C60 molecule, single- and multi-wall carbon nanotubes, nanodiamonds, and recently graphene. During this period, research published in the journal Nanotechnology has revealed the amazing mechanical properties of such materials as well as their remarkable electronic properties with the promise of new devices. Furthermore, nanoparticles, nanotubes, nanorods, and nanowires from metals and dielectrics have been characterized for their electronic, mechanical, optical, chemical and catalytic properties. Scanning probe microscopy (SPM) has become the main characterization technique and atomic force microscopy (AFM) the most frequently used SPM. Over the past twenty years, SPM techniques that were previously experimental in nature have become routine. At the same time, investigations using AFM continue to yield impressive results that demonstrate the great potential of this powerful imaging tool, particularly in close to physiological conditions. In this special issue a collaboration of researchers in Europe report the use of AFM to provide high-resolution topographical images of individual carbon nanotubes immobilized on various biological membranes, including a nuclear membrane for the first time (Lamprecht C et al 2009 Nanotechnology 20 434001). Other SPM developments such as high-speed AFM appear to be making a transition from specialist laboratories to the mainstream, and perhaps the same may be said for non-contact AFM. Looking to the future, characterisation techniques involving SPM and spectroscopy, such as tip-enhanced Raman spectroscopy, could emerge as everyday methods. In all these advanced techniques, routinely available probes will

  8. Chemical substitution in silica polymorph (United States)

    Smith, J. V.; Steele, I. M.


    Ion and electron probe analyses are presented for trace elements (Al, Na, K, Li, Ti) in quartz, tridymite, cristobalite and melanophlogite. Quartz and melanophlogite show low levels of trace elements relative to tridymite and cristobalite. The previously determined alpha-beta inversion temperature decreases as the Al content of quartz increases. For all silica polymorphs, Al is greater than or equal to Na + K + Li on an atom basis, with the excess Al probably balanced by H.

  9. Archiver ce qui aurait pu avoir lieu

    Directory of Open Access Journals (Sweden)

    Stefanie Baumann


    Full Text Available L’Atlas Group, un projet de l’artiste libanais Walid Raad, est « dédié à la recherche et la compilation de documents sur l’histoire contemporaine libanaise. L’Atlas Group produit, localise, conserve et étudie des documents visuels, sonores, textuels et autres, qui mettent en lumière l’histoire actuelle du Liban. »Ce projet est ainsi présenté comme une fondation qui génère des archives historiques et qui collecte des traces relevant de la guerre au Liban afin de les mettre à disposition aux chercheurs. Mais, les matériaux sont produits par l’artiste : l’archive est imaginaire, les documents et récits sont inventés, ainsi que le Docteur Fakhouhi, le personnage principal, présenté comme étant « le plus renommé des historiens au Liban ». Le spectateur se trouve alors devant un scénario très étrange dans lequel sont détournées les notions de document (qui peut désormais être aussi bien trouvé que produit et d’histoire (car les situations décrites sont considérées comme « ayant très bien pu avoir eu lieu », l’Atlas Group  les traite comme de véritables événement historiques et qui déplace, mine de rien, tout un dispositif. Au sein de ce projet, la frontière entre fiction et documentaire est complètement estompée : le geste de l’artiste (qui, lui, se présente comme une institution, un « Groupe », interroge ainsi le statut même d’auteur vise à la déplacer pour poser des questions relatives aux représentations possibles de l’histoire, aux personnes aptes à se charger de son écriture et à l’opération historiographique.

  10. What happened to blood substitutes? (United States)

    Stowell, C P


    Concerns about the safety and adequacy of the blood supply have fostered twenty years of research into the so-called "blood substitutes" among them the oxygen carriers based on modified hemoglobin. Although none of these materials has yet been licensed for use in North America or Europe, the results of research and clinical trials have increased our understanding of oxygen delivery and its regulation. In particular, the examination of the basis for the vasoactivity observed with some of the hemoglobin based oxygen carriers has led to the insight that several colligative properties of hemoglobin solutions, such as their diffusion coefficient for oxygen, viscosity and colloid oncotic pressure, are important determinants of efficacy.

  11. Current status of erythrocyte substitutes. (United States)

    Biro, G. P.


    During the last two decades the search for alternatives to whole blood transfusions has led to promising developments in the field of erythrocyte substitutes. Hemoglobin solutions free of fragments of erythrocyte stroma and fluorocarbon emulsions are not blood-type-specific and appear likely to satisfy some proportion of our blood requirements. Both must be modified before becoming clinically useful. The oxygen affinity of the hemoglobin solution must be reduced and its intravascular persistence improved. Fluorocarbons cannot yet contribute significantly to the oxygen supply unless the patient breathes hyperbaric oxygen. Recent advances are leading to solutions for these problems. PMID:6344974

  12. Possible Frustration Effects on a New Antiferromagnetic Compound Ce6Pd13Zn4 with the Octahedral Ce Sublattice (United States)

    Matsuoka, Eiichi; Oshima, Akihiro; Sugawara, Hitoshi; Sakurai, Takahiro; Ohta, Hitoshi


    Magnetization, specific heat, and electrical resistivity measurements have been performed on polycrystalline samples of a new cubic compound, Ce6Pd13Zn4. This compound exhibits metallic behavior and is classified as a Kondo-lattice system. The trivalent Ce ions are responsible for the antiferromagnetic transition at TN = 3.3 K and the phase transition at T'N = 1.3 K with the formation of superzone gaps. The increase in magnetic susceptibilities below TN and the considerably large value of the specific heat divided by temperature (1.25 J·Ce-mol-1·K-2) imply the existence of non-ordered Ce magnetic moments due to the geometrical frustration on the octahedral Ce sublattice.

  13. Thiolate ligands as a double-edged sword for CO oxidation on CeO2-supported Au25(SR)18 nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zili [ORNL; Jiang, Deen [ORNL; Mann, Amanda K [ORNL; Mullins, David R [ORNL; Qiao, Zhen-an [University of Tennessee, Knoxville (UTK); Allard Jr, Lawrence Frederick [ORNL; Zeng, Chenjie [Carnegie Mellon University (CMU); Jin, Rongchao [Carnegie Mellon University (CMU); Overbury, Steven {Steve} H [ORNL


    The effect of thiolate ligands was explored on the catalysis of CeO2-rod supported Au25(SR)18 (SR = -SCH2-CH2-Ph) by using CO oxidation as a probe reaction. Reaction kinetic tests, in situ IR and X-ray absorption spectroscopy, and density functional theory (DFT) were employed to understand how the thiolate ligands affect the nature of active sites, activation of CO and O2, as well as the reaction mechanism and kinetics. The intact Au25(SR)18 on CeO2-rod is found not able to adsorb CO. Only when the thiolate ligands are partially removed, starting from the interface between Au25(SR)18 and CeO2 at temperatures of 423 K and above, can the adsorption of CO be observed by IR. DFT calculations suggest that CO adsorbs favorably on the exposed gold atoms. Accordingly, the CO oxidation light-off temperature shifts to lower temperature. Several types of Au sites are probed by IR of CO adsorption during the ligand removal process. The cationic Au sites (charged between 0 and +1) are found to play the major role for low temperature CO oxidation. Similar activation energy and reaction rate are found for CO oxidation on differently treated Au25(SR)18/CeO2-rod, suggesting a simple site-blocking effect of the thiolate ligands in Au nanoclusters catalysis. Isotopic labelling experiments clearly indicate that CO oxidation on Au25(SR)18/CeO2-rod proceeds predominantly via the redox mechanism where CeO2 activates O2 while CO is activated on the de-thiolated gold sites. These results points to a double-edged sword role played by the thiolate ligands on Au25 nanoclusters for CO oxidation.

  14. Biologic and synthetic skin substitutes: An overview

    Directory of Open Access Journals (Sweden)

    Halim Ahmad


    Full Text Available The current trend of burn wound care has shifted to more holistic approach of improvement in the long-term form and function of the healed burn wounds and quality of life. This has demanded the emergence of various skin substitutes in the management of acute burn injury as well as post burn reconstructions. Skin substitutes have important roles in the treatment of deep dermal and full thickness wounds of various aetiologies. At present, there is no ideal substitute in the market. Skin substitutes can be divided into two main classes, namely, biological and synthetic substitutes. The biological skin substitutes have a more intact extracellular matrix structure, while the synthetic skin substitutes can be synthesised on demand and can be modulated for specific purposes. Each class has its advantages and disadvantages. The biological skin substitutes may allow the construction of a more natural new dermis and allow excellent re-epithelialisation characteristics due to the presence of a basement membrane. Synthetic skin substitutes demonstrate the advantages of increase control over scaffold composition. The ultimate goal is to achieve an ideal skin substitute that provides an effective and scar-free wound healing.

  15. Electronic Structure of CeFeAsO1-xFx (x=0, 0.11/x=0.12) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Bondino, F.; Magnano, E.; Booth, C. H.; Offi, F.; Panaccione, G.; Malvestuto, M.; Paolicelli, G.; Simonelli, L.; Parmigiani, F.; McGuire, M. A.; Sefat, A. S.; Sales, B. C.; Jin, R.; Vilmercati, P.; Mandrus, D.; Singh, D. J.; Mannella, N.


    We report an extensive study on the intrinsic bulk electronic structure of the high-temperature superconductor CeFeAsO{sub 0.89}F{sub 0.11} and its parent compound CeFeAsO by soft and hard x-ray photoemission, x-ray absorption and soft-x-ray emission spectroscopies. The complementary surface/bulk probing depth, and the elemental and chemical sensitivity of these techniques allows resolving the intrinsic electronic structure of each element and correlating it with the local structure, which has been probed by extended-x-ray absorption fine structure spectroscopy. The measurements indicate a predominant 4f{sup 1} (i.e. Ce{sup 3+}) initial state configuration for Cerium and an effective valence-band-to-4f charge-transfer screening of the core hole. The spectra also reveal the presence of a small Ce f{sup 0} initial state configuration, which we assign to the occurrence of an intermediate valence state. The data reveal a reasonably good agreement with the partial density of states as obtained in standard density functional calculations over a large energy range. Implications for the electronic structure of these materials are discussed.

  16. Physical probing of cells (United States)

    Rehfeldt, Florian; Schmidt, Christoph F.


    In the last two decades, it has become evident that the mechanical properties of the microenvironment of biological cells are as important as traditional biochemical cues for the control of cellular behavior and fate. The field of cell and matrix mechanics is quickly growing and so is the development of the experimental approaches used to study active and passive mechanical properties of cells and their surroundings. Within this topical review we will provide a brief overview, on the one hand, over how cellular mechanics can be probed physically, how different geometries allow access to different cellular properties, and, on the other hand, how forces are generated in cells and transmitted to the extracellular environment. We will describe the following experimental techniques: atomic force microscopy, traction force microscopy, magnetic tweezers, optical stretcher and optical tweezers pointing out both their advantages and limitations. Finally, we give an outlook on the future of the physical probing of cells.

  17. Novel Eddycurrent Probe Development. (United States)


    oVCut MVc AVu inc F C -- -(1)(-jlOOO AZC (23)0 --2--M F1 (23) If the Thevenin source voltages, V0, are adjusted so that Vinc is the same for both small as 1.2 cm. The differential probe assembly was spring loaded about a pivot post (see Figure 12) so it could scan noncircular or eccentric

  18. Space Probe Launch (United States)


    Managed by Marshall Space Flight Center, the Space Tug was a reusable multipurpose space vehicle designed to transport payloads to different orbital inclinations. Utilizing mission-specific combinations of its three primary modules (crew, propulsion, and cargo) and a variety of supplementary kits, the Space Tug was capable of numerous space applications. This 1970 artist's concept depicts the Tug's propulsion module launching a space probe into lunar orbit.

  19. Einstein Inflationary Probe (EIP) (United States)

    Hinshaw, Gary


    I will discuss plans to develop a concept for the Einstein Inflation Probe: a mission to detect gravity waves from inflation via the unique signature they impart to the cosmic microwave background (CMB) polarization. A sensitive CMB polarization satellite may be the only way to probe physics at the grand-unified theory (GUT) scale, exceeding by 12 orders of magnitude the energies studied at the Large Hadron Collider. A detection of gravity waves would represent a remarkable confirmation of the inflationary paradigm and set the energy scale at which inflation occurred when the universe was a fraction of a second old. Even a strong upper limit to the gravity wave amplitude would be significant, ruling out many common models of inflation, and pointing to inflation occurring at much lower energy, if at all. Measuring gravity waves via the CMB polarization will be challenging. We will undertake a comprehensive study to identify the critical scientific requirements for the mission and their derived instrumental performance requirements. At the core of the study will be an assessment of what is scientifically and experimentally optimal within the scope and purpose of the Einstein Inflation Probe.

  20. Hard Probes at RHIC

    Directory of Open Access Journals (Sweden)

    Bielčíková Jana


    Full Text Available Measurements of jets and heavy flavour, the so called hard probes, play a crucial role in understanding properties of hot and dense nuclear matter created in high energy heavy-ion collisions. The measurements at the Relativistic Heavy Ion Collider (RHIC showed that in central Au+Au collisons at RHIC energy ( √sNN = 200 GeV the nuclear matter created has properties close to those of perfect liquid, manifests partonic degrees of freedom and is opaque to hard probes. In order to draw quantitative conclusions on properties of this hot and dense nuclear matter reference measurements in proton-proton collisions and d+Au collisions are essential to estimate cold nuclear matter effects. In this proceedings a review of recent results on hard probes measurements in p+p, d+Au and A+A collisions as well as of beam energy dependence of jet quenching from STAR and PHENIX experiments at RHIC is presented.

  1. Probing dimensionality using a simplified 4-probe method. (United States)

    Kjeldby, Snorre B; Evenstad, Otto M; Cooil, Simon P; Wells, Justin W


    4-probe electrical measurements have been in existence for many decades. One of the most useful aspects of the 4-probe method is that it is not only possible to find the resistivity of a sample (independently of the contact resistances), but that it is also possible to probe the dimensionality of the sample. In theory, this is straightforward to achieve by measuring the 4-probe resistance as a function of probe separation. In practice, it is challenging to move all four probes with sufficient precision over the necessary range. Here, we present an alternative approach. We demonstrate that the dimensionality of the conductive path within a sample can be directly probed using a modified 4-probe method in which an unconventional geometry is exploited; three of the probes are rigidly fixed, and the position of only one probe is changed. This allows 2D and 3D (and other) contributions the to resistivity to be readily disentangled. The required experimental instrumentation can be vastly simplified relative to traditional variable spacing 4-probe instruments.

  2. Properties and practical application of thin CeOx films

    Directory of Open Access Journals (Sweden)

    Maksimchuk N. V.


    Full Text Available The properties of CeOx films produced by various methods have been investigated. According to the comparative analisys “metallic mirror oxidation” method allows to produce films with significantly better characteristics than the «explosive evaporation» method. Though the latter method yields higher photosensitivity of CeOx films and structures on their base. In the process the optimal value of the substrate temperature was determined. Obtained data expand the CeOx application potential in microelectronic sensor sphere.

  3. Electrical Properties of a CeO2-Bi2O3 Mix System Elaborated at 600°C

    Directory of Open Access Journals (Sweden)

    Lamia Bourja


    Full Text Available The electrical conduction of a series of polycristalline [(1−xCeO2⋅x/2Bi2O3] samples has been analyzed using electrical impedance spectroscopy, in the temperature range 25 to 750∘C. Samples have been prepared via a coprecipitation route followed by a pyrolysis process at 600∘C. For compositions x≤0.20, Ce1−xBixO2−x/2 solid solutions, with fluorite cubic structure, are obtained. In the composition range 0.30≤x≤1, the system is biphasic with coexistence of cubic and tetragonal structures. To interpret the Nyquist representations of electrical analyses, various impedance models including constant phase elements and Warburg impedances have been used. In the biphasic range (0.30≤x≤0.7, the conductivity variation might be related to the increasing fraction of two tetragonal β′ and β-Bi2O3 phases. The stabilization of the tetragonal phase coexisting with substituted ceria close to composition x=0.7 is associated with a high conduction of the mix system CeO2-Bi2O3.

  4. HumanViCe: Host ceRNA network in virus infected cells in human

    Directory of Open Access Journals (Sweden)

    Suman eGhosal


    Full Text Available Host-virus interaction via host cellular components has been an important field of research in recent times. RNA interference mediated by short interfering RNAs and microRNAs (miRNA, is a widespread anti-viral defence strategy. Importantly, viruses also encode their own miRNAs. In recent times miRNAs were identified as key players in host-virus interaction. Furthermore, viruses were shown to exploit the host miRNA networks to suite their own need. The complex cross-talk between host and viral miRNAs and their cellular and viral targets forms the environment for viral pathogenesis. Apart from protein-coding mRNAs, non-coding RNAs may also be targeted by host or viral miRNAs in virus infected cells, and viruses can exploit the host miRNA mediated gene regulatory network via the competing endogenous RNA effect. A recent report showed that viral U-rich non-coding RNAs called HSUR, expressed in primate virus herpesvirus saimiri (HVS infected T cells, were able to bind to three host miRNAs, causing significant alteration in cellular level for one of the miRNAs. We have predicted protein coding and non protein-coding targets for viral and human miRNAs in virus infected cells. We identified viral miRNA targets within host non-coding RNA loci from AGO interacting regions in three different virus infected cells. Gene ontology (GO and pathway enrichment analysis of the genes comprising the ceRNA networks in the virus infected cells revealed enrichment of key cellular signalling pathways related to cell fate decisions and gene transcription, like Notch and Wnt signalling pathways, as well as pathways related to viral entry, replication and virulence. We identified a vast number of non-coding transcripts playing as potential ceRNAs to the immune response associated genes; e.g. APOBEC family genes, in some virus infected cells. All these information are compiled in HumanViCe, a comprehensive database that provides the potential ceRNA networks in virus

  5. Dynamics of Excited State Proton Transfer in Nitro Substituted 10-Hydroxybenzo[h]quinolines

    DEFF Research Database (Denmark)

    Marciak, H; Hristova, S.; Deneva, V


    of the ground state enol–keto tautomeric equilibrium (ΔG values of 1.03 and 0.62 kcal mol−1 respectively for 2 and 3). The fluorescence stems from the keto form even if the enol form is optically excited as proven by the shape of the excitation spectra indicating that ESIPT takes place. The Stokes shift...... of the substituted compounds is substantially lower compared to HBQ, which follows from the fact that the substitution occurs in the formal cyclohexa-2,4-dienone moiety and leads to a decrease of the HOMO level of the keto tautomer. The pump–probe experiments show that in the nitro substituted HBQs 2 and 3 ESIPT...

  6. Laser Shock Compression Studies of Phase Changes in Ce3 Al Metallic Glass (United States)

    Bryant, Alex; Wehrenberg, Christopher; Alamgir, Faisal; Remington, Bruce; Thadhani, Naresh


    Laser shock-compression of Ce3 Al metallic glass (MG) was performed to probe pressure-induced phase transitions. Ce3 Al MG has been previously shown to crystallize into a single crystal FCC phase during static compression at 25 GPa. In the present work, experiments were performed using the 3J Nd:YAG pulse laser at Georgia Tech and the high energy laser at the OMEGA facility. Characterization of shock compressed samples recovered from the OMEGA laser experiments were performed using XRD and PDF measurements at the NSLS-2 synchrotron at Brookhaven National Lab. The results showed evidence of a permanent polyamorphous phase change at pressures > 10 GPa and crystallization at pressures > 75 GPa. Particle velocities were measured using VISAR in experiments performed at Georgia Tech and simulated using Hyades and Abaqus to create an empirical equation of state and correlate with results obtained from XRD and PDF characterization. The results attained to-date in terms of the evolution of the high pressure amorphous and crystalline phases and their correlations with the shock conditions will be presented. This work is supported in part by ARO Grant No. W9HNF-09-1-0403 and the National Science Foundation Graduate Research Fellowship Program awarded to Alex Bryant under Grant No. 0946809.

  7. Feasibility of a wireless gamma probe in radioguided surgery (United States)

    Park, Hye Min; Joo, Koan Sik


    Radioguided surgery through the use of a gamma probe is an established practice, and has been widely applied in the case of sentinel lymph node biopsies. A wide range of intraoperative gamma probes is commercially available. The primary characteristics of the gamma probes include their sensitivity, spatial resolution, and energy resolution. We present the results obtained from a prototype of a new wireless gamma probe. This prototype is composed of a 20 mm thick cerium-doped gadolinium aluminum gallium garnet (Ce:GAGG) inorganic scintillation crystal from Furukawa Denshi and a Hamamatsu S12572-100C multi-pixel photon counter equipped with a designed electronics. The measured performance characteristics include the energy resolution, energy linearity, angular aperture, spatial resolution and sensitivity. Measurements were carried out using 57Co, 133Ba, 22Na, and 137Cs sources. The energy resolutions for 0.122 and 0.511 MeV were 17.2% and 6.9%, respectively. The designed prototype consumes an energy of approximately 4.4 W, weighs about 310 g (including battery) having a dimension of 20 mm (D)  ×  130 mm (L).

  8. Information Technology and Transportation: Substitutes or Complements?


    Oliver, Atara Stephanie


    The increased availability and prevalence of Information and Communications Technology (ICT) provides opportunities to use such products as substitutes for transportation. Common examples of this substitution are telecommuting, video conferences, and online classes. However, despite the intuitive appeal of a substitution relationship existing between ICT and transportation, prior research has indicated that the relationship between ICT and transportation is quite complex; at times ICT substit...

  9. Comparative evaluation of probing depth and clinical attachment level using a manual probe and Florida probe. (United States)

    Kour, Amandeep; Kumar, Ashish; Puri, Komal; Khatri, Manish; Bansal, Mansi; Gupta, Geeti


    To compare and evaluate the intra- and inter-examiner efficacy and reproducibility of the first-generation manual (Williams) probe and the third-generation Florida probe in terms of measuring pocket probing depth (PD) and clinical attachment level (CAL). Forty subjects/4000 sites were included in this comparative, cross-sectional study. Group- and site-wise categorizations were done. Based on gingival index, PD, and CAL, patients were divided into four groups, i.e., periodontally healthy, gingivitis, mild to moderate periodontitis, and severe periodontitis. Further, based on these parameters, a total of 4000 sites, with 1000 sites in each category randomly selected from these 40 patients, were taken. Full mouth PD and CAL measurements were recorded with two probes, by Examiner 1 and on Ramfjord teeth by Examiner 2. Full mouth and Ramfjord teeth group- and site-wise PD obtained with the manual probe by both the examiners were statistically significantly deeper than that obtained with the Florida probe. The full mouth and Ramfjord teeth mean CAL measurement by Florida probe was higher as compared to manual probe in mild to moderate periodontitis group and sites, whereas in severe periodontitis group and sites, manual probe recorded higher CAL as compared to Florida probe. Mean PD and CAL measurements were deeper with the manual probe as compared to the Florida probe in all the groups and sites, except for the mild-moderate periodontitis group and sites where the CAL measurements with the manual probe were less than the Florida probe. Manual probe was more reproducible and showed less interexaminer variability as compared to the Florida probe.

  10. Wearable probes for service design

    DEFF Research Database (Denmark)

    Mullane, Aaron; Laaksolahti, Jarmo Matti; Svanæs, Dag


    Probes are used as a design method in user-centred design to allow end-users to inform design by collecting data from their lives. Probes are potentially useful in service innovation, but current probing methods require users to interrupt their activity and are consequently not ideal for use...... by service employees in reflecting on the delivery of a service. In this paper, we present the ‘wearable probe’, a probe concept that captures sensor data without distracting service employees. Data captured by the probe can be used by the service employees to reflect and co-reflect on the service journey......, helping to identify opportunities for service evolution and innovation....

  11. Substitutions in Calcium Aluminates and Calcium Aluminoferrites. (United States)


  12. Development of Mackintosh Probe Extractor (United States)

    Rahman, Noor Khazanah A.; Kaamin, Masiri; Suwandi, Amir Khan; Sahat, Suhaila; Jahaya Kesot, Mohd


    Dynamic probing is a continuous soil investigation technique, which is one of the simplest soil penetration test. It basically consist of repeatedly driving a metal tipped probe into the ground using a drop weight of fixed mass and travel. Testing was carried out continuously from ground level to the final penetration depth. Once the soil investigation work done, it is difficult to pull out the probe rod from the ground, due to strong soil structure grip against probe cone and prevent the probe rod out from the ground. Thus, in this case, a tool named Extracting Probe was created to assist in the process of retracting the probe rod from the ground. In addition, Extracting Probe also can reduce the time to extract the probe rod from the ground compare with the conventional method. At the same time, it also can reduce manpower cost because only one worker involve to handle this tool compare with conventional method used two or more workers. From experiment that have been done we found that the time difference between conventional tools and extracting probe is significant, average time difference is 155 minutes. In addition the extracting probe can reduce manpower usage, and also labour cost for operating the tool. With all these advantages makes this tool has the potential to be marketed.

  13. Controversial issues of maternity substitution

    Directory of Open Access Journals (Sweden)

    Andy Pușcă


    Full Text Available Substitute maternity consists in a woman carrying a pregnancy (the implant of an embryo, at therequest of a sterile couple, most of the times in exchange of a sum of money, with her commitment tounconditionally give away the newborn after birth to the couple she concluded the agreement with. Manycontroversies emerged in what concerns the contract between the sterile couple and the carrying mother,especially when this contract is by onerous title, which happens in most of the cases. In that a civil contract? Is ita sales contract for the child? Is it a contract to provide services? Is it body marketing? Between total prohibitionand excessive liberalism, the middle way, which is the regulation according to ethical religious, cultural andsocial norms of each community, represents a realistic solution.

  14. Production of {sup 139}Ce by the {sup 139}La(p,n){sup 139}Ce reaction

    Energy Technology Data Exchange (ETDEWEB)

    Ishioka, Noriko S.; Sekine, Toshiaki [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Izumo, Mishiroku; Hashimoto, Kazuyuki; Kobayashi, Katsutoshi; Matsuoka, Hiromitsu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment


    To produce a carrier-free {sup 139}Ce to be used as an efficiency-calibration source for Ge detectors, a target-preparation method and a chemical separation method were studied. It was found that commercially available powders of lanthanum-oxide and lanthanum metal are applicable to a target material in the nuclear reaction {sup 139}La(p,n){sup 139}Ce. In the separation of {sup 139}Ce from an irradiated lanthanum target, a solvent-extraction method and an ion-exchange method gave final products in good chemical purity. (author)

  15. Origin of enhanced visible-light photocatalytic activity of transition-metal (Fe, Cr and Co)-doped CeO{sub 2}: effect of 3d orbital splitting

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ke; Li, Dong-Feng; Huang, Wei-Qing; Xu, Liang; Huang, Gui-Fang; Wen, Shuangchun [Hunan University, Department of Applied Physics, School of Physics and Electronics, Changsha (China)


    Enhanced visible-light photocatalytic activity of transition-metal-doped ceria (CeO{sub 2}) nanomaterials has experimentally been demonstrated, whereas there are very few reports mentioning the mechanism of this behavior. Here, we use first-principles calculations to explore the origin of enhanced photocatalytic performance of CeO{sub 2} doped with transition metal impurities (Fe, Cr and Co). When a transition metal atom substitutes a Ce atom into CeO{sub 2}, t{sub 2g} and e{sub g} levels of 3d orbits appear in the middle of band gap owing to the effect of cubic ligand field, and the former is higher than latter. Interestingly, t{sub 2g} subset of Fe{sub Ce} (Co{sub Ce} and Cr{sub Ce})-V{sub o}-CeO{sub 2} splits into two parts: one merges into the conduction band, the other as well as e{sub g} will remain in the gap, because O vacancy defect adjacent to transition metal atom will break the symmetry of cubic ligand field. These e{sub g} and t{sub 2g} levels in the band gap are beneficial for absorbing visible-light and enhancing quantum efficiency because of forbidden transition, which is one key factor for enhanced visible-light photocatalytic activity. The band gap narrowing also leads to a redshift of optical absorbance and high photoactivity. These findings can rationalize the available experimental results and provide some new insights for designing CeO{sub 2}-based photocatalysts with high photocatalytic performance. (orig.)

  16. Temperature-independent photoluminescence response in ZnO:Ce ...

    Indian Academy of Sciences (India)


    Ce3+ nanophosphors prepared by combustion method and solid-state reaction method is presented in this study. The powder XRD exhibits hexagonal wurtzite phase and crystallite size falls in the nanometre range. The optical ...

  17. Uued IT-mõtted CeBITilt / Kai Simson

    Index Scriptorium Estoniae

    Simson, Kai


    Riigi Infosüsteemide Arenduskeskuse (RIA) pressiesindaja Rica Semjonova vahendab Eesti stendistide muljeid Hannoveris toimunud IT-messilt CeBIT, kus Eestit tutvustasid nii riigiametid kui eraettevõtted

  18. Inorganic analysis using CE: advanced methodologies to face old challenges. (United States)

    Kubáň, Petr; Timerbaev, Andrei R


    Inorganic species still remain of secondary importance when CE is used as an analytical separation tool. Despite considerable efforts of great many groups over last 20 years, plenty of competition, mostly from ion chromatography and elemental MS, restrains the routine use of CE in inorganic analysis. If there is yet hope clinging to make CE a viable alternative in the field, success would ultimately be attained through research activities on negating the disadvantages and amplifying the advantages of the method. Being the latest update of a series of reviews covering the time period from 1990 to 2010, this paper will comment on how and to what extent these challenges of inorganic CE analysis have been addressed in two recent years. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. CeDeC, materiales educativos al alcance de todos


    González, Agala


    El Centro Nacional de Desarrollo Curricular en Sistemas no Propietarios (CeDeC) tiene como finalidad el diseño, la promoción y el desarrollo de materiales educativos digitales a través de software libre. CeDeC pone a disposición de toda la comunidad educativa materiales y recursos educativos en su portal web

  20. Optical properties of CeO2 thin films

    Indian Academy of Sciences (India)

    Cerium oxide (CeO2) thin films have been prepared by electron beam evaporation technique onto glass substrate at a pressure of about 6 × 10-6 Torr. The thickness of CeO2 films ranges from 140–180 nm. The optical properties of cerium oxide films are studied in the wavelength range of 200–850 nm. The film is highly ...

  1. Thermodynamic Study of Ce4+ /Ce3+ Redox Reaction in Aqueous Solutions at Elevated Temperatures: 1. Reduction Potential and Hydrolysis Equilibria of Ce4+ in HCIO4 Solutions (United States)

    Bilal, B. A.; Müller, E.


    The redox potential (E) of the couple Ce4+/Ce3+ has been determined up to 368 K by means of cyclic voltammetric measurement in aqueous HClO4 solutions with cHClO4 decreasing from 7.45 to 0.023 mol kg-1 . A constant potential of (1.741 V)298 K, resp. (1.836 V)368K, indicating the existence of pure unhydrolysed Ce4+ was obtained at cHClO4 ≥ 6.05 m. At lower HClO4 concentration, the potential as a function of the HClO4 molality, as well as of the pH shows 4 further distinct steps. At 298 K, for instance, the potential became nearly constant at pH values of 0.103, 0.735,1.115, after which it drastically decreased, respectively at 1.679, just before the precipitation of Ce(OH)4 occurred. The curves indicate obviously the stepwise formation of the Ce(IV) mono-, di-, tri- and tetrahydroxo complexes. The slope of the curves E vs. pH increased gradually with increasing temperature. ΔS and ΔH of the redox reaction were determined as functions of T at the different HClO4 concentrations. ΔSis positive at cHClO4 > 1.85 m and turns to be negative at lower concentrations. ΔHis negative at all HClO4 concentrations studied. The cumulative formation constants ßi, of the Ce(IV) hydroxo complexes and the corresponding hydrolysis constants (Kh)i were calculated. An unusual decrease of ßi with increasing temperature has been discussed

  2. Accurate borehole probe calibration

    Energy Technology Data Exchange (ETDEWEB)

    Tchen, T.; Eisler, P. (CSIRO, Mount Waverley, Vic. (Australia). Division of Geomechanics)

    The In Situ Minerals Analysis Group in the CSIRO Division of Geomechanics has developed quantitative borehole logging techniques applicable to iron-ore and coal deposits. They are used currently to determine the formation density, either the iron-ore grades or the raw coal-ash contents, as appropriate, and the borehole diameter. The in-situ analyses depend on probe-calibration equations which were formulated by linear regression analysis that related the probe's spectral outputs with the required geological variable. Calibration equations consisting of a linear combination of first-order terms gave excellent assaying accuracy. The group achieved further improvements in assaying accuracy by developing a more generalised calibration model based on second-order terms and cross-product terms of the probe's spectral parameters. The logging data used for the statistical analysis were recorded in mine development boreholes at three Pilbara iron-ore mines and at a Queensland coal mine. Application of the generalised model, in place of the first-order model, resulted in a reduction of the root mean square (RMS) deviation between assays obtained in the laboratory and by logging, of about 15% relative for iron-ore grades and of about 8% relative for raw coal-ash content. The study also shows that the accuracy obtained using the conventional, non-spectrometric calibration model is inferior to that obtained by using either of the two spectrometric models, where the comparisons made are based on the same set of logging data. 8 refs., 6 figs., 3 tabs.

  3. PROcess Based Diagnostics PROBE (United States)

    Clune, T.; Schmidt, G.; Kuo, K.; Bauer, M.; Oloso, H.


    Many of the aspects of the climate system that are of the greatest interest (e.g., the sensitivity of the system to external forcings) are emergent properties that arise via the complex interplay between disparate processes. This is also true for climate models most diagnostics are not a function of an isolated portion of source code, but rather are affected by multiple components and procedures. Thus any model-observation mismatch is hard to attribute to any specific piece of code or imperfection in a specific model assumption. An alternative approach is to identify diagnostics that are more closely tied to specific processes -- implying that if a mismatch is found, it should be much easier to identify and address specific algorithmic choices that will improve the simulation. However, this approach requires looking at model output and observational data in a more sophisticated way than the more traditional production of monthly or annual mean quantities. The data must instead be filtered in time and space for examples of the specific process being targeted.We are developing a data analysis environment called PROcess-Based Explorer (PROBE) that seeks to enable efficient and systematic computation of process-based diagnostics on very large sets of data. In this environment, investigators can define arbitrarily complex filters and then seamlessly perform computations in parallel on the filtered output from their model. The same analysis can be performed on additional related data sets (e.g., reanalyses) thereby enabling routine comparisons between model and observational data. PROBE also incorporates workflow technology to automatically update computed diagnostics for subsequent executions of a model. In this presentation, we will discuss the design and current status of PROBE as well as share results from some preliminary use cases.

  4. The effective degeneration of the ground state as tuning parameter in CeNi{sub 9-x}TM{sub x}Ge{sub 4} (TM=Cu, Co); Die effektive Entartung des Grundzustandes als Tuningparameter in CeNi{sub 9-x}TM{sub x}Ge{sub 4} (TM=Cu, Co)

    Energy Technology Data Exchange (ETDEWEB)

    Peyker, Ludwig


    The work is based on the heavy fermion system CeNi9Ge4 with its extraordinary four times degenerated ground state. A quantum critical state could be observed in the Cu substituted compound in CeNi{sub 9-x}Cu{sub x}Ge{sub 4}. Substitution of Ni by Cu above x= 0.5 results in a long-range antiferromagnetic order without loosing the single ion character. The quantum critical scenario is based in the reduction of the effective spin degeneration of the ground state. This process was studied using inelastic neutron scattering. The energetic crystal field splitting between ground state and the first excited Kramer doublet is increasing with increasing Cu concentration. At the same time the Kondo temperature is decreasing. The change of the crystal field scheme was observed using neutron diffraction experiments. Using Co substitution instead of Cu the influence of the effective spin degeneration on the magnetic properties was studied. Starting at x = 0.1 Co a logarithmic increase of the specific heat was observed besides the increase of the Fermi liquid temperature indicating a quantum critical point. Thus the change of the effective spin degeneration of the ground state is a new tuning parameter for quantum critical scenarios that can be influences by chemical pressure or substitution.

  5. A single L288I substitution in the fusion protein of bovine parainfluenza virus type 3 enhances virus growth in semi-suitable cell lines. (United States)

    Matsuura, Ryosuke; Takada, Marina; Kokuho, Takehiro; Tsuboi, Takamitsu; Kameyama, Ken-Ichiro; Takeuchi, Kaoru


    The bovine parainfluenza virus type 3 BN-CE vaccine strain was obtained by serial passage of the BN-1 strain in chicken embryonic fibroblasts (CEF). We previously identified a substitution (L288I) in the fusion (F) protein between the two strains. To examine the effect of the substitution on CEF adaptation and attenuation, we generated a recombinant BN-1 strain with the L288I substitution in the F protein (F L288I -EGFP). F L288I -EGFP replicated more efficiently than a recombinant BN-1 strain (wt-EGFP) in semi-suitable cell lines, suggesting that the L288I substitution was established in the BN-1 strain during the process of adaptation in CEF.

  6. CE-SAM: a conversational interface for ISR mission support (United States)

    Pizzocaro, Diego; Parizas, Christos; Preece, Alun; Braines, Dave; Mott, David; Bakdash, Jonathan Z.


    There is considerable interest in natural language conversational interfaces. These allow for complex user interactions with systems, such as fulfilling information requirements in dynamic environments, without requiring extensive training or a technical background (e.g. in formal query languages or schemas). To leverage the advantages of conversational interactions we propose CE-SAM (Controlled English Sensor Assignment to Missions), a system that guides users through refining and satisfying their information needs in the context of Intelligence, Surveillance, and Reconnaissance (ISR) operations. The rapidly-increasing availability of sensing assets and other information sources poses substantial challenges to effective ISR resource management. In a coalition context, the problem is even more complex, because assets may be "owned" by different partners. We show how CE-SAM allows a user to refine and relate their ISR information needs to pre-existing concepts in an ISR knowledge base, via conversational interaction implemented on a tablet device. The knowledge base is represented using Controlled English (CE) - a form of controlled natural language that is both human-readable and machine processable (i.e. can be used to implement automated reasoning). Users interact with the CE-SAM conversational interface using natural language, which the system converts to CE for feeding-back to the user for confirmation (e.g. to reduce misunderstanding). We show that this process not only allows users to access the assets that can support their mission needs, but also assists them in extending the CE knowledge base with new concepts.

  7. Strong broad green UV-excited photoluminescence in rare earth (RE = Ce, Eu, Dy, Er, Yb) doped barium zirconate

    Energy Technology Data Exchange (ETDEWEB)

    Borja-Urby, R. [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico); Diaz-Torres, L.A., E-mail: [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico); Salas, P. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro, Qro. 76000 (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Ciudad de Mexico, D. F. 07730 (Mexico); Meza, O. [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A. C., Leon, Gto. 37150 (Mexico)


    Highlights: > Trivalent rare earth (RE) substitution on Zr{sup 4+} sites in BaZrO{sub 3} lead to band gap narrowing. > RE substitution lead to enhanced blue-green intrinsic emission of nanocrystalline BaZrO{sub 3} > Blue-green hue of BaZrO3:RE depends on RE dopant and excitation UV wavelength > BaZrO3: Dy{sup 3+} PL chromatic coordinates correspond to pure white color coordinates of CIE 1931 model - Abstract: The wet synthesis hydrothermal method at 100 deg. C was used to elaborate barium zirconate (BaZrO{sub 3}) unpurified with 0.5 mol% of different rare earth ions (RE = Yb, Er, Dy, Eu, Ce). Morphological, structural and UV-photoluminescence properties depend on the substituted rare earth ionic radii. While the crystalline structure of RE doped BaZrO{sub 3} remains as a cubic perovskite for all substituted RE ions, its band gap changes between 4.65 and 4.93 eV. Under 267 nm excitation the intrinsic green photoluminescence of the as synthesized BaZrO{sub 3}: RE samples is considerably improved by the substitution on RE ions. For 1000 deg. C annealed samples, under 267 nm, the photoluminescence is dominated by the intrinsic BZO emission. It is interesting to notice that Dy{sup 3+}, Er{sup 3+} and Yb{sup 3+} doped samples present whitish emissions that might be useful for white light generation under 267 nm excitation. CIE color coordinates are reported for all samples.

  8. Cerocene Revisited: The Electronic Structure of and Interconversion Between Ce2(C8H8)3 and Ce(C8H8)2

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Marc D.; Booth, Corwin H.; Lukens, Wayne W.; Andersen, Richard A.


    New synthetic procedures for the preparation of Ce(cot)2, cerocene, from [Li(thf)4][Ce(cot)2], and Ce2(cot)3 in high yield and purity are reported. Heating solid Ce(cot)2 yields Ce2(cot)3 and COT while heating Ce2(cot)3 with an excess of COT in C6D6 to 65oC over four months yields Ce(cot)2. The solid state magnetic susceptibility of these three organocerium compounds shows that Ce(cot)2 behaves as a TIP (temperature independent paramagnet) over the temperature range of 5-300 K, while that of Ce2(cot)3 shows that the spin carriers are antiferromagnetically coupled below 10 K; above 10 K, the individual spins are uncorrelated, and [Ce(cot)2]- behaves as an isolated f1 paramagnet. The EPR at 1.5K for Ce2(cot)3 and [Ce(cot)2]- have ground state of MJ= +- 1/2. The LIII edge XANES of Ce(cot)2 (Booth, C.H.; Walter, M.D.; Daniel, M.; Lukens, W.W., Andersen, R.A., Phys. Rev. Lett. 2005, 95, 267202) and 2Ce2(cot)3 over 30-500 K are reported; the Ce(cot)2 XANES spectra show Ce(III) and Ce(IV) signatures up to a temperature of approximately 500 K, whereupon the Ce(IV) signature disappears, consistent with the thermal behavior observed in the melting experiment. The EXAFS of Ce(cot)2 and Ce2(cot)3 are reported at 30 K; the agreement between the molecular parameters for Ce(cot)2 derived from EXAFS and single crystal X-ray diffraction data are excellent. In the case of Ce2(cot)3 no X-ray diffraction data are known to exist, but the EXAFS are consistent with a"triple-decker" sandwich structure. A molecular rationalization is presented for the electronic structure of cerocene having a multiconfiguration ground state that is an admixture of the two configurations Ce(III, 4f1)(cot1.5-)2 and Ce(IV, 4f0)(cot2-)2; the multiconfigurational ground state has profound effects on the magnetic properties and on the nature of the chemical bond in cerocene and, perhaps, other molecules.

  9. Type Substitution for Object-Oriented Programming

    DEFF Research Database (Denmark)

    Schwartzbach, Michael Ignatieff; Palsberg, Jens


    Genericity allows the substitution of types in a class. This is usually obtained through parameterized classes, although they are inflexible since any class can be inherited but is not in itself parameterized. We suggest a new genericity mechanism, type substitution, which is a subclassing concep...

  10. Educators Take Another Look at Substitutes (United States)

    Zubrzycki, Jaclyn


    The mythology surrounding the substitute teacher is not a pretty one: Paper airplanes, lost learning, bullying. But as schools collect more information about teacher absenteeism and its consequences, districts and schools are exploring ways to professionalize substitute teaching--or experiment with alternative ways of coping with teacher absences.…

  11. 5 CFR 1201.35 - Substituting parties. (United States)


    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Substituting parties. 1201.35 Section... AND PROCEDURES Procedures for Appellate Cases Parties, Representatives, and Witnesses § 1201.35 Substituting parties. (a) If an appellant dies or is otherwise unable to pursue the appeal, the processing of...

  12. 25 CFR 522.9 - Substitute approval. (United States)


    ... 25 Indians 2 2010-04-01 2010-04-01 false Substitute approval. 522.9 Section 522.9 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR APPROVAL OF CLASS II AND CLASS III ORDINANCES AND RESOLUTIONS SUBMISSION OF GAMING ORDINANCE OR RESOLUTION § 522.9 Substitute approval. If the Chairman fails to...

  13. Strategic Resource Extraction And Substitute Development

    NARCIS (Netherlands)

    Michielsen, T.O.


    Abstract We analyze a dynamic game between a buyer and a seller of an exhaustible resource. The seller chooses resource supply; the buyer can pay a fixed cost to invent a perfect substitute for the resource at any time. In closed-loop equilibrium, the buyer adopts the substitute when the resource is

  14. Substitute Your Way to a Real Job (United States)

    Stephens, Cathy


    For some, substitute teaching is a career choice. However, for the majority of new teachers, it is often a necessary gateway to landing a first job. Either way, it is a great way to sharpen one's skills. This article presents tips from principals, teachers, and human resource directors to make the most of the substitute teaching experience…

  15. Substitute Teachers: Making Lost Days Count (United States)

    True, Charlene; Butler, Kyle; Sefton, Rachel


    As K-12 teachers and administrators grow increasingly concerned with issues of accountability, research-based methods, and intervention strategies, little discussion exists on the impact of substitute teachers in the classroom. In the rush to analyze test scores, are the days covered by substitute teachers even considered? Though districts are…

  16. Multisensory integration, sensory substitution and visual rehabilitation

    DEFF Research Database (Denmark)

    Proulx, Michael J; Ptito, Maurice; Amedi, Amir


    Sensory substitution has advanced remarkably over the past 35 years since first introduced to the scientific literature by Paul Bach-y-Rita. In this issue dedicated to his memory, we describe a collection of reviews that assess the current state of neuroscience research on sensory substitution......, visual rehabilitation, and multisensory processes....

  17. Performance comparison between ceramic Ce:GAGG and single crystal Ce:GAGG with digital-SiPM (United States)

    Park, C.; Kim, C.; Kim, J.; Lee, Y.; Na, Y.; Lee, K.; Yeom, J. Y.


    The Gd3Al2Ga3O12 (Ce:GAGG) is a new inorganic scintillator known for its attractive properties such as high light yield, stopping power and relatively fast decay time. In this study, we fabricated a ceramic Ce:GAGG scintillator as a cost-effective alternative to single crystal Ce:GAGG and, for the first time, investigated their performances when coupled to the digital silicon photomultiplier (dSiPM)—a new type of photosensor designed for applications in medical imaging, high energy and astrophysics. Compared to 3 × 3 × 2 mm3 sized single crystal Ce:GAGG, the translucent ceramic Ce:GAGG, which has a much lower transmittance than the single crystal, was determined to give an output signal amplitude that is approximately 61% of single crystal Ce:GAGG. The energy resolution of the 511 keV annihilation peak of a 22Na source was measured to be 9.9 ± 0.2% and 13.0 ± 0.3% for the single and ceramic scintillators respectively. On the other hand, the coincidence resolving time (CRT) of ceramic Ce:GAGG was 307 ± 23 ps, better than the 465 ± 37 ps acquired with single crystals—probably attributed to its slightly faster decay time and higher proportion of the fast decay component. The ceramic Ce:GAGG may be a promising cost-effective candidate for applications that do not require thick scintillators such as x-ray detectors and charged particle detectors, and those that require time-of-flight capabilities.

  18. Crystal structure and magnetic properties of Ce{sub 2}Fe{sub 14−x}Co{sub x}B alloys

    Energy Technology Data Exchange (ETDEWEB)

    Skoug, Eric J.; Meyer, M.S.; Pinkerton, F.E. [Chemical and Materials Systems Laboratory, General Motors Research and Development Center, Mail Code 480-106-224, Warren, MI 48090-9055 (United States); Tessema, Misle M. [Optimal CAE, Inc., 14492 Sheldon Road, Plymouth, MI 48170 (United States); Haddad, Daad [MEDA Engineering and Technical Services, LLC, 17515 West Nine Mile Road, Southfield, MI 48075 (United States); Herbst, J.F., E-mail: [Chemical and Materials Systems Laboratory, General Motors Research and Development Center, Mail Code 480-106-224, Warren, MI 48090-9055 (United States)


    Highlights: •Annealed melt-spun Ce{sub 3}Fe{sub 14−x}Co{sub x}B or Ce{sub 2.55}Fe{sub 14−x}Co{sub x}B{sub 1.27} ribbons maintain the Ce{sub 2}Fe{sub 14}B crystal structure only for x ⩽ 5. •In contrast to many other R{sub 2}Fe{sub 14}B materials, we find no evidence for the formation of Ce{sub 2}Co{sub 14}B. •The Curie temperature increases rapidly with increasing cobalt content x, reaching ∼660 K for x = 5. •Ce{sub 3}Fe{sub 12}Co{sub 2}B offers significant improvement in T{sub c}, B{sub r}, and (BH){sub max} relative to its Co-free analog with only modest H{sub ci} loss. -- Abstract: Permanent magnet materials based on the R{sub 2}Fe{sub 14}B phase (R = rare earth element) are essential to a wide variety of applications, among them automotive traction motors. Current state-of-the-art materials rely on R = Nd and Dy, for both of which there are supply uncertainties and rapidly rising costs. A possible alternative is R = Ce, the most abundant rare earth, but Ce{sub 2}Fe{sub 14}B has several disadvantages, including a low Curie temperature (T{sub c}) that limits its maximum operating point to well below that required for some automotive uses. Here we systematically investigate the Ce{sub 2}Fe{sub 14−x}Co{sub x}B system by exploring Co substitution for Fe in melt-spun ribbons as a means of increasing T{sub c}. In addition to T{sub c} we report the solubility of Co in Ce{sub 2}Fe{sub 14}B and its effect on the crystal structure and hard magnetic properties.

  19. Effect of ceria structural properties on the catalytic activity of Au-CeO2 catalysts for WGS reaction. (United States)

    Vindigni, F; Manzoli, M; Tabakova, T; Idakiev, V; Boccuzzi, F; Chiorino, A


    Two gold based catalysts supported on ceria prepared by different methods (urea gelation coprecipitation, UGC, and coprecipitation, CP) have been synthesized and tested in the WGS reaction, showing quite different catalytic behaviors. Interestingly, the two catalysts have the same gold loading (3 wt% Au was inserted by deposition-precipitation) and the FTIR spectroscopy of the adsorbed CO revealed the same amount of gold exposed sites. With the aim to elucidate how the preparation method affects the properties of the support, a morphological, structural and textural characterization has been performed by HRTEM, XRD, BET and Raman analyses, as well as FTIR spectroscopy to probe both the Au and the support exposed sites. It was found that the UGC method gave rise to an enhancement of the defectivity of ceria and to an increase of the reactivity under reductive treatment. Further FTIR measurements of adsorbed acetone demonstrated the presence of two kinds of Ce(4+) sites with different coordination, (CUS) Ce(4+) A and (CUS) Ce(4+) B, on the UGC sample. Such sites can influence the catalytic activity, possibly favoring the water dissociation, making ceria prepared by UGC a better support for Au catalysts than the CP-prepared one.

  20. Fluorescence-tagged metallothionein with CdTe quantum dots analyzed by the chip-CE technique

    Energy Technology Data Exchange (ETDEWEB)

    Guszpit, Ewelina, E-mail: [Wroclaw Medical University, Department of Biomedical and Environmental Analysis, Faculty of Pharmacy (Poland); Krizkova, Sona [Mendel University in Brno, Department of Chemistry and Biochemistry, Faculty of Agronomy (Czech Republic); Kepinska, Marta [Wroclaw Medical University, Department of Biomedical and Environmental Analysis, Faculty of Pharmacy (Poland); Rodrigo, Miguel Angel Merlos [Mendel University in Brno, Department of Chemistry and Biochemistry, Faculty of Agronomy (Czech Republic); Milnerowicz, Halina [Wroclaw Medical University, Department of Biomedical and Environmental Analysis, Faculty of Pharmacy (Poland); Kopel, Pavel; Kizek, Rene [Mendel University in Brno, Department of Chemistry and Biochemistry, Faculty of Agronomy (Czech Republic)


    Quantum dots (QDs) are fluorescence nanoparticles (NPs) with unique optic properties which allow their use as probes in chemical, biological, immunological, and molecular imaging. QDs linked with target ligands such as peptides or small molecules can be used as tumor biomarkers. These particles are a promising tool for selective, fast, and sensitive tagging and imaging in medicine. In this study, an attempt was made to use QDs as a marker for human metallothionein (MT) isoforms 1 and 2. Four kinds of CdTe QDs of different sizes bioconjugated with MT were analyzed using the chip-CE technique. Based on the results, it can be concluded that MT is willing to interact with QDs, and the chip-CE technique enables the observation of their complexes. It was also observed that changes ranging roughly 6–7 kDa, a value corresponding to the MT monomer, depend on the hydrodynamic diameters of QDs; also, the MT sample without cadmium interacted stronger with QDs than MT saturated with cadmium. Results show that MT is willing to interact with smaller QDs (blue CdTe) rather than larger ones QDs (red CdTe). To our knowledge, chip-CE has not previously been applied in the study of CdTe QDs interaction with MT.Graphical Abstract.

  1. The role of calcification for staging cystic echinococcosis (CE)

    Energy Technology Data Exchange (ETDEWEB)

    Hosch, Waldemar; Kauffmann, Guenter W. [University Hospital Heidelberg, Department of Radiology, Heidelberg (Germany); Stojkovic, Marija; Junghanss, Thomas [University Hospital of Heidelberg, Section of Clinical Tropical Medicine, Heidelberg (Germany); Jaenisch, Thomas [University Hospital of Heidelberg, Section of Clinical Tropical Medicine, Heidelberg (Germany); University Hospital of Heidelberg, Section of Biostatistics and Epidemiology, Heidelberg (Germany)


    The prevalence of calcified cysts and the significance of calcification as a sign of cyst inactivity in cystic echinococcosis (CE) was evaluated. Seventy-eight patients (36 females, 42 males, mean age 40.8 {+-} 16.9 years) with CE, having a total of 137 abdominal cysts (116 hepatic, three splenic, one renal and 17 peritoneal cysts), were diagnosed and followed-up by ultrasound during and after albendazole treatment or as part of the watch-and-wait approach recording changes in the cyst wall and content. In 48 patients with 94 cysts, computed tomography (CT) imaging was additionally available and was correlated with ultrasound findings. Cyst wall calcification was classified into (1) ''sprinkled'', (2) ''eggshell-like'', and (3) ''circular''. Calcification of the cyst wall and/or cyst content was detected in 67 echinococcal cysts (48.9% of all cysts) in 39 patients (15 females, 24 males, mean age 40.8 {+-} 14.8 years). Of the total of 67 calcified cysts, only 23 were compatible with WHO type CE5, 18 with WHO type CE4. Judged by cyst content, the remaining 26 were of WHO type CE1, CE2 and CE3 (n = 1, n = 8, and n = 17, respectively). During a mean period of 34.3 months ({+-}21.3 months) the majority of cysts (n = 32) did not exhibit any change in cyst content and wall properties. Fourteen cysts showed signs of progressive involution, five cysts (all of WHO type CE3) of renewed activity defined by recurring fluid collection. In 16 cysts, no follow-up was available due to surgery or drop out. Calcification of the cyst is not restricted to the inactive WHO cyst types CE4 and CE5, but occurs in all stages and in up to 50% of cysts. The completeness and, most importantly, the stability of consolidation of cyst content over time predicts cyst inactivity more reliably. (orig.)

  2. Substitution between cars within the household

    DEFF Research Database (Denmark)

    De Borger, Bruno; Mulalic, Ismir; Rouwendal, Jan


    .98 and 1.41 for the primary and secondary cars, respectively. Accounting for substitution effects, these figures reduce to, respectively, 0.32 and 0.45. Consistent with substitution behaviour, we find that the fuel price elasticity of fuel demand exceeds the elasticity of kilometre demands with respect......In this paper we study the demand for car kilometres in two-car households, focusing on the substitution between cars of different fuel efficiency in response to fuel price changes. We use a large sample of detailed Danish data on two-car households to estimate – for each car owned by the household...... – own and cross-price effects of increases in fuel costs per kilometre. The empirical results show that failure to capture substitution between cars within the household can result in substantial misspecification biases. Ignoring substitution, the basic model yielded fuel price elasticities of 0...

  3. Substitution between Cars within the Household

    DEFF Research Database (Denmark)

    de Borger, Bruno; Mulalic, Ismir; Rouwendal, Jan

    In this paper we study the demand for car kilometres in two-car households, focusing on the substitution between cars in response to fuel price changes. We use a large sample of detailed Danish data on two-car households to estimate—for each car owned by the household—own and cross-price effects...... of increases in fuel costs per kilometre. The empirical results show that failure to capture substitution between cars within the household can result in substantial misspecification biases. Ignoring substitution, we estimate fuel price elasticities of –0.81 and -0.65 for the primary and secondary cars......, respectively. When we do take into account the substitution effect, these figures reduce to, respectively, -0.32 and -0.45. We further estimate an alternative version of the model to test the hypothesis that substitution in response to higher fuel prices will be predominantly from the least to the most fuel...

  4. X ray diffraction analysis of IrO{sub 2}/TiO{sub 2}/CeO{sub 2} ceramic oxide films; Analise por difracao de raios X de filmes de oxidos ceramicos compostos por IrO{sub 2}/TiO{sub 2}/CeO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Valeria Almeida [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Quimica; Silva, Luis Antonio da [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Dept. de Morfologia; Boodts, Julien Francoise Coleta [Uberlandia Univ., MG (Brazil). Dept. de Quimica


    Independent of the sample form (powder or film), XRD analysis of Ir {sub 0,3} Ti{sub (}0{sub ,7x}) Ce{sub x} O{sub 2}, (nominal) mixture, for x=0, shows the formation of a solid solution phase between Ir O{sub 2} and Ti O{sub 2}, as well as the rutile phases of Ir O{sub 2} and Ti O{sub 2}. The presence of the anatase phase of Ti O{sub 2} is also confirmed. The introduction of 30 mol % Ce O{sub 2} in the mixture reveals the presence of the Ce O{sub 2} and Ce O{sub 2} and Ce{sub 2} O{sub 3} phases, besides the already mentioned ones, in the powder. In the film form, however, an amorphous phase is identified. When all of the Ti O{sub 2} is substituted by Ce O{sub 2}, for both sample forms, the only phases found are Ir O{sub 2} Ce O{sub 2} and Ce{sub 2} O{sub 3}. This result suggests cerium oxides are not capable of forming solid solutions with either Ir O{sub 2} or (Ir, Ti) O{sub 2} acting solely as dispersant matrix for these phases. These results are consistent with the much higher electrochemically active surface area when Ce O{sub 2} is introduced in the binary Ti/Ir{sub 0,3} Ti{sub O,7} O{sub 2} mixture. It was possible to establish a relationship between the electrochemical stability of the supported films and their crystalline structure. The unexpected presence of Ti O{sub 2} and Ti O{sub 2} O{sub 3} in the Ti/Ir{sub 0,3} Ce{sub 0,7} O{sub 2} (film sample) is attribute dto oxidation of the Ti support during the calcination step. (author)

  5. Simultaneous determination of scopolamine, hyoscyamine and anisodamine in in vitro growth media of selected Solanaceae hairy roots by CE method. (United States)

    Dziomba, Szymon; Łepek, Teresa; Jaremicz, Zbigniew; Łuczkiewicz, Maria; Prahl, Adam; Kowalski, Piotr


    An electrophoretic method for fast separation of three tropane alkaloids (hyoscyamine, anisodamine and scopolamine) was presented. The substances were complete resolved in less than one minute due to utilization of relatively short capillary (20.2cm effective length) and high voltage (25kV). Detector probing frequency was found among the parameters that significantly affected the detection sensitivity. The performed experiments showed insufficient available probing frequency of used commercial spectrophotometric detector according to capillary electrophoresis (CE) separation potential. Under the optimized conditions the background electrolyte (BGE) was composed of 20mM Tris, 6mM HCl and 20mM NaCl (pH 8.50). All analyses were carried out in fused silica capillaries of 50μm (inner diameter) and 31.2cm (total capillary length). Samples were injected hydrodynamically (5s; 3.45kPa) without any sample preparation step and separation was performed at 25kV. The elaborated method was applied in plant cultures growth media analysis after incubation with hairy roots of selected Solanaceae species. The performed experiments proved the usefulness of CE in quality control of biotechnological processes. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. The Galaxy Evolution Probe (United States)

    Glenn, Jason; Galaxy Evolution Probe Team


    The Galaxy Evolution Probe (GEP) is a concept for a far-infrared observatory to survey large regions of sky for star-forming galaxies from z = 0 to beyond z = 3. Our knowledge of galaxy formation is incomplete and requires uniform surveys over a large range of redshifts and environments to accurately describe mass assembly, star formation, supermassive black hole growth, interactions between these processes, and what led to their decline from z ~ 2 to the present day. Infrared observations are sensitive to dusty, star-forming galaxies, which have bright polycyclic aromatic hydrocarbon (PAH) emission features and warm dust continuum in the rest-frame mid infrared and cooler thermal dust emission in the far infrared. Unlike previous far-infrared continuum surveys, the GEP will measure photometric redshifts commensurate with galaxy detections from PAH emission and Si absorption features, without the need for obtaining spectroscopic redshifts of faint counterparts at other wavelengths.The GEP design includes a 2 m diameter telescope actively cooled to 4 K and two instruments: (1) An imager covering 10 to 300 um with 25 spectral resolution R ~ 8 bands (with lower R at the longest wavelengths) to detect star-forming galaxies and measure their redshifts photometrically. (2) A 23 – 190 um, R ~ 250 dispersive spectrometer for redshift confirmation and identification of obscured AGN using atomic fine-structure lines. Lines including [Ne V], [O IV], [O III], [O I], and [C II] will probe gas physical conditions, radiation field hardness, and metallicity. Notionally, the GEP will have a two-year mission: galaxy surveys with photometric redshifts in the first year and a second year devoted to follow-up spectroscopy. A comprehensive picture of star formation in galaxies over the last 10 billion years will be assembled from cosmologically relevant volumes, spanning environments from field galaxies and groups, to protoclusters, to dense galaxy clusters.Commissioned by NASA, the

  7. Substituted Hydroxyapatites with Antibacterial Properties

    Directory of Open Access Journals (Sweden)

    Joanna Kolmas


    Full Text Available Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also presenting low toxicity to the human cells. Such factors are usually implemented along with the implant itself and may be an integral part of it. Many recent studies have focused on inorganic factors, such as metal nanoparticles, salts, and metal oxides. The advantages of inorganic factors include the ease with which they can be combined with ceramic and polymeric biomaterials. The following review focuses on hydroxyapatites substituted with ions with antibacterial properties. It considers materials that have already been applied in regenerative medicine (e.g., hydroxyapatites with silver ions and those that are only at the preliminary stage of research and which could potentially be used in implantology or dentistry. We present methods for the synthesis of modified apatites and the antibacterial mechanisms of various ions as well as their antibacterial efficiency.

  8. Uproar over Milk Substitutes Act. (United States)


    Health policy activists lobbied 7 years for the Infant Milk Substitutes, Feeding Bottles and Infant Food Bill. Proponents of the bill say that it basically curtails unethical marketing practices, not the sales of baby foods, and argue that it was conceived to reduce the trend of mothers over-diluting commercial milk in order to reduce household expenses as well as stem the potential erosion of knowledge on locally available weaning foods. Even though the bill will become an Act only after its rules and regulations have been finalized, the government has already banned baby food advertisements on television and in other electronic media under its control. Women's groups now argue that the bill tends to focus almost exclusively upon the welfare of children and compromises the position of women who can not lactate adequately. Moreover, they hold that the bill may be used to compel wives to stay out of the formal workforce so that they may feed their babies. The intention of the bill may be meaningless without complementary legislation addressing the problems of working mothers. Specifically, amendments to the Maternity Benefits Act of 1961 would extend maternity leave to 4 months after delivery and lengthen the duration of nursing breaks. It is, however, feared that these changes may reduce employment prospects for women.

  9. Enhanced arsenic removal from water by hierarchically porous CeO₂-ZrO₂ nanospheres: role of surface- and structure-dependent properties. (United States)

    Xu, Weihong; Wang, Jing; Wang, Lei; Sheng, Guoping; Liu, Jinhuai; Yu, Hanqing; Huang, Xing-Jiu


    Arsenic contaminated natural water is commonly used as drinking water source in some districts of Asia. To meet the increasingly strict drinking water standards, exploration of efficient arsenic removal methods is highly desired. In this study, hierarchically porous CeO₂-ZrO₂ nanospheres were synthesized, and their suitability as arsenic sorbents was examined. The CeO₂-ZrO₂ hollow nanospheres showed an adsorption capacity of 27.1 and 9.2 mg g(-1) for As(V) and As(III), respectively, at an equilibrium arsenic concentration of 0.01 mg L(-1) (the standard for drinking water) under neutral conditions, indicating a high arsenic removal performance of the adsorbent at low arsenic concentrations. Such a great arsenic adsorption capacity was attributed to the high surface hydroxyl density and presence of hierarchically porous network in the hollow nanospheres. The analysis of Fourier transformed infrared spectra and X-ray photoelectron spectroscopy demonstrated that the adsorption of arsenic on the CeO₂-ZrO₂ nanospheres was completed through the formation of a surface complex by substituting hydroxyl with arsenic species. In addition, the CeO₂-ZrO₂ nanospheres were able to remove over 97% arsenic in real underground water with initial arsenic concentration of 0.376 mg L(-1) to meet the guideline limit of arsenic in drinking water regulated by the World Health Organization without any pre-treatment and/or pH adjustment. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Cosmological Probes for Supersymmetry

    Directory of Open Access Journals (Sweden)

    Maxim Khlopov


    Full Text Available The multi-parameter character of supersymmetric dark-matter models implies the combination of their experimental studies with astrophysical and cosmological probes. The physics of the early Universe provides nontrivial effects of non-equilibrium particles and primordial cosmological structures. Primordial black holes (PBHs are a profound signature of such structures that may arise as a cosmological consequence of supersymmetric (SUSY models. SUSY-based mechanisms of baryosynthesis can lead to the possibility of antimatter domains in a baryon asymmetric Universe. In the context of cosmoparticle physics, which studies the fundamental relationship of the micro- and macro-worlds, the development of SUSY illustrates the main principles of this approach, as the physical basis of the modern cosmology provides cross-disciplinary tests in physical and astronomical studies.

  11. Recent contributions for improving sensitivity in chiral CE. (United States)

    Crego, Antonio Luis; Mateos, María; Nozal, Leonor


    The flexibility and versatility of the chiral CE are unrivaled and the same instrumentation can be used to separate a diverse range of analytes, both large and small molecules, whether charged or uncharged. However, one of the disadvantages is generally thought to be the poor sensitivity of ultraviolet (UV) detection, which is the most popular among CE detectors. This review focuses on methodologies and applications regarding improvements of sensitivity in chiral CE published in the last 2 years (June 2015 until May 2017). This contribution continues to update this series of biannual reviews, first published in Electrophoresis in 2006. The main body of the review brings a survey of publications organized according to different approaches to detect a low amount of analytes, either by sample treatment procedures or by in-capillary sample preconcentration techniques, both using UV detection, or even by employing detection systems more sensitive than UV absorption, such as LIF or MS. This review provides comprehensive tables listing the new approaches in sensitive chiral CE with categorizing by the fundamental mechanism to enhance the sensitivity, which provide relevant information on the strategies employed. The concluding remarks in the final part of the review evaluate present state of art and the trends for sensitivity enhancement in chiral CE. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Antiferromagnetic Kondo lattice compound CePt3P. (United States)

    Chen, Jian; Wang, Zhen; Zheng, Shiyi; Feng, Chunmu; Dai, Jianhui; Xu, Zhu'an


    A new ternary platinum phosphide CePt3P was synthesized and characterized by means of magnetic, thermodynamic and transport measurements. The compound crystallizes in an antiperovskite tetragonal structure similar to that in the canonical family of platinum-based superconductors APt3P (A = Sr, Ca, La) and closely related to the noncentrosymmetric heavy fermion superconductor CePt3Si. In contrast to all the superconducting counterparts, however, no superconductivity is observed in CePt3P down to 0.5 K. Instead, CePt3P displays a coexistence of antiferromagnetic ordering, Kondo effect and crystalline electric field effect. A field-induced spin-flop transition is observed below the magnetic ordering temperature TN1 of 3.0 K while the Kondo temperature is of similar magnitude as TN1. The obtained Sommerfeld coefficient of electronic specific heat is γCe = 86 mJ/mol·K2 indicating that CePt3P is a moderately correlated antiferromagnetic Kondo lattice compound.

  13. An Update on NiCE Support for BISON

    Energy Technology Data Exchange (ETDEWEB)

    McCaskey, Alex [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Billings, Jay Jay [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Deyton, Jordan H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wojtowicz, Anna [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)


    The Nuclear Energy Advanced Modeling and Simulation program (NEAMS) from the Department of Energy s Office of Nuclear Energy has funded the development of a modeling and simulation workflow environment to support the various codes in its nuclear energy scientific computing toolkit. This NEAMS Integrated Computational Environment (NiCE) provides extensible tools and services that enable efficient code execution, input generation, pre-processing visualizations, and post-simulation data analysis and visualization for a large portion of the NEAMS Toolkit. A strong focus for the NiCE development team throughout FY 2015 has been support for the Multiphysics Object Oriented Simulation Environment (MOOSE) and the NEAMS nuclear fuel performance modeling application built on that environment, BISON. There is a strong desire in the program to enable and facilitate the use of BISON throughout nuclear energy research and industry. A primary result of this desire is the need for strong support for BISON in NiCE. This report will detail improvements to NiCE support for BISON. We will present a new and improved interface for interacting with BISON simulations in a variety of ways: (1) improved input model generation, (2) embedded mesh and solution data visualizations, and (3) local and remote BISON simulation launch. We will also show how NiCE has been extended to provide support for BISON code development.

  14. Moessbauer Study of Multiple Substitutions in YBCO

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, M.; Patel, N. V.; Mehta, P. K.; Somayajulu, D. R. S. [M.S. University, Physics Department (India)


    Moessbauer studies of multiple substitutions in YBCO with general formula (Y{sub 1-Z}Ca{sub Z})Ba{sub 2}(Cu{sub 1-X-Y}Fe{sub Y}M{sub X}){sub 3}O{sub 7-{delta}} are reported. XRD has been used to find out the lattice parameters. All the samples show a single tetragonal phase formation. Iodometric titration is done to estimate the oxygen content. The present study discusses the effect of multiple substitutions of 3d-ions like Ni, Zn, Co, Mn, Cr in YBCO and the effect of various substitutions on charge balancing, oxygen content and site occupancy.

  15. Elasticity of Substitution and Antidumping Measures

    DEFF Research Database (Denmark)

    Drud Hansen, Jørgen; Meinen, Philipp; Nielsen, Jørgen Ulff-Møller

    therefore also vary inversely with the elasticity of substitution at least for countries which have a strong focus on prices in the determination of their anti-dumping measures. We test this for ten countries from 1990 to 2009 using data on anti-dumping from Chad Bown (2010) and US-data at 8-digit level......Abstract This paper analyzes the role of the elasticity of substitution for anti-dumping decisions across countries. In monopolistic competition models with cost heterogeneous firms across countries, price differences vary inversely with the elasticity of substitution. Anti-dumping duties should...

  16. Comparing the dynamic and thermodynamic behaviors of Al{sub 86}Ni{sub 9}-La{sub 5}/(La{sub 0.5}Ce{sub 0.5}){sub 5} amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Li, G.H. [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Wang, W.M. [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China)], E-mail:; Bian, X.F.; Zhang, J.T.; Li, R.; Wang, L. [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China)


    The dynamic viscosities and thermodynamic dilatometric behaviors of Al{sub 86}Ni{sub 9}La{sub 5} and Al{sub 86}Ni{sub 9}(La{sub 0.5}Ce{sub 0.5}){sub 5} amorphous alloys were investigated using viscometer, differential scanning calorimetry (DSC) and conventional dilatometer. Comparing with Al{sub 86}Ni{sub 9}La{sub 5} alloy, Al{sub 86}Ni{sub 9}(La{sub 0.5}Ce{sub 0.5}){sub 5} alloy exhibits a larger viscosity and a larger average thermal expansion coefficient in the linear expansion zone ({alpha}{sub exp}). The viscosity and thermal expansion data suggest that the partial substitution La by Ce decreases the quantity of free volume in Al-Ni-La system by improving the continuous degree of atomic size, which leads to the improvement of glass forming ability.

  17. Activation of ethers and sulfides by organolanthanide hydrides - molecular-structures of (cp-asterisk(2)y)(2)(mu- och(2)ch(2)0)(thf)(2) and (cp-asterisk-ce-2)(2)(mu-o)(thf)(2)

    NARCIS (Netherlands)

    Deelman, B.J; Booij, M.; Meetsma, A.; Teuben, J.H; Kooijman, H.; Spek, A.L.

    Dialkyl ethers, ROR', are cleaved by hydrides (Cp*(2)LnH)(2) (Ln = Y 1a, La 1b, Ce 1c) to form alkoxides Cp*(2)LnOR (2), Cp*(2)LnOR', R'H, and RH. The extent to which either of the C-O bonds of asymmetric substituted dialkyl ethers ROR' is attacked strongly depends on the alkyl substituents but is

  18. Gene probes: principles and protocols

    National Research Council Canada - National Science Library

    Rapley, Ralph; Aquino de Muro, Marilena


    ... of labeled DNA has allowed genes to be mapped to single chromosomes and in many cases to a single chromosome band, promoting significant advance in human genome mapping. Gene Probes: Principles and Protocols presents the principles for gene probe design, labeling, detection, target format, and hybridization conditions together with detailed protocols, accom...

  19. Non-inductive current probe

    DEFF Research Database (Denmark)

    Bak, Christen Kjeldahl


    The current probe described is a low-cost, shunt resistor for monitoring current pulses in e.g., pulsed lasers. Rise time is......The current probe described is a low-cost, shunt resistor for monitoring current pulses in e.g., pulsed lasers. Rise time is...

  20. Stirling-cycle cooler reliability growth at L-3 CE (United States)

    Arndt, David; Kuo, Dan; Phan, Quang


    L-3 CE has in place a continuous effort to evaluate and improve the lifetime of its cryocooler products. This effort includes analysis of both lab environment reliability tests and field data from shipped units. The purpose of this paper is to outline L-3 CE's life testing methodology and provide reliability data for L-3 CE cryocoolers, specifically for the 0.6- Watt Cooler (Model B602), 1.0-Watt Reduced Size, Weight, and Power (RSWAP) Cooler (Model B610), and the 1.5- Watt Cooler (Model B1500). Cooler performance characteristics such as cooldown time, refrigeration capacity, and input power are monitored throughout the life of the cooler. The data presented here updates previously reported data. Field data for the 1.0-Watt Cooler (Model B1000) is also presented.

  1. Synthesis of acetylene-substituted probes with benzene-phosphate backbones for RNA labeling. (United States)

    Kitamura, Yoshiaki; Ueno, Yoshihito; Kitade, Yukio


    Conversion of dimethyl 5-aminoisophthalate into the iodoarene via the corresponding diazonium intermediate, followed by Sonogashira coupling with trimethylsilylacetylene afford the alkynylarene, which is reduced with LiAlH4 to give 5-ethynyl-1,3-benzenedimethanol (B(E)). One hydroxyl group is protected with a 4,4'-dimethoxytrityl (DMTr) group and subsequently another hydroxyl group is phosphitylated to produce the phosphoramidite. The mono-DMTr compound is also modified to afford the corresponding succinate, which is then reacted with controlled pore glass (CPG) to provide the solid support. Either the phosphoramidite or the solid support is employed in solid-phase synthesis of RNA containing B(E). RNA oligomers bearing B(E) rapidly react with 4-fluorobenzylazide to produce the cycloaddition products in good to excellent yield. Copyright © 2014 John Wiley & Sons, Inc.

  2. Probing the active site of aromatase with 2-methyl-substituted androstenedione analogs. (United States)

    Numazawa, Mitsuteru; Watari, Yoko; Yamada, Keiko; Umemura, Nao; Handa, Wakako


    To gain insight into the spatial nature of the androstenedione (AD) binding (active) site of aromatase in relation to the catalytic function of the enzyme, we synthesized 2,2-dimethylAD (4), 2beta- and 2alpha-methylADs (5 and 6), 19-oxygenated derivatives of compounds 4 and 6, and 2-methyleneAD (17), and we then tested their inhibitory activity as well as their aromatase reaction (aromatization for 2-methyl and 2-methylene analogs or 19-oxygenation for 2,2-dimethyl steroids) with human placental aromatase. 2-Methyl and 2-methylene steroids 5, 6, and 17 were good competitive inhibitors of aromatase (K(i)=22-68nM), but less effective compared to the 2,2-dimethyl analog 4 (K(i)=8.8nM), indicating that a combination of 2beta- and 2alpha-methyl moieties is essential for the formation of a thermodynamically stable inhibitor-aromatase complex. A series of 2alpha-methyl steroids were good substrates for aromatase, whereas 2beta-methyl steroid 5 was an extremely poor substrate, and a series of 2,2-dimethyl steroids did not serve as substrate, suggesting that a 2beta-methyl moiety of the 2,2-dimethyl and 2beta-methyl steroids would prevent the aromatase reaction probably due to steric hindrance in each case. The 2-methylene compound 17 was also aromatized to produce 2-methylestrogen with a low conversion rate where the 1,4-diene structure may have been created before the C(10)-C(19) bond cleavage. Kinetic analysis of the aromatization of androgens revealed that a good substrate was not essentially a good inhibitor for aromatase.

  3. Mobile Probes in Mobile Learning

    DEFF Research Database (Denmark)

    Ørngreen, Rikke; Blomhøj, Ulla; Duvaa, Uffe

    In this paper experiences from using mobile probes in educational design of a mobile learning application is presented. The probing process stems from the cultural probe method, and was influenced by qualitative interview and inquiry approaches. In the project, the mobile phone was not only acting...... as an agent for acquiring empirical data (as the situation in hitherto mobile probe settings) but was also the technological medium for which data should say something about (mobile learning). Consequently, not only the content of the data but also the ways in which data was delivered and handled, provided...... a valuable dimension for investigating mobile use. The data was collected at the same time as design activities took place and the collective data was analysed based on user experience goals and cognitive processes from interaction design and mobile learning. The mobile probe increased the knowledge base...

  4. Rotating concave eddy current probe (United States)

    Roach, Dennis P [Albuquerque, NM; Walkington, Phil [Albuquerque, NM; Rackow, Kirk A [Albuquerque, NM; Hohman, Ed [Albuquerque, NM


    A rotating concave eddy current probe for detecting fatigue cracks hidden from view underneath the head of a raised head fastener, such as a buttonhead-type rivet, used to join together structural skins, such as aluminum aircraft skins. The probe has a recessed concave dimple in its bottom surface that closely conforms to the shape of the raised head. The concave dimple holds the probe in good alignment on top of the rivet while the probe is rotated around the rivet's centerline. One or more magnetic coils are rigidly embedded within the probe's cylindrical body, which is made of a non-conducting material. This design overcomes the inspection impediment associated with widely varying conductivity in fastened joints.

  5. Nanobits: customizable scanning probe tips

    DEFF Research Database (Denmark)

    Kumar, Rajendra; Shaik, Hassan Uddin; Sardan Sukas, Özlem


    We present here a proof-of-principle study of scanning probe tips defined by planar nanolithography and integrated with AFM probes using nanomanipulation. The so-called 'nanobits' are 2-4 mu m long and 120-150 nm thin flakes of Si3N4 or SiO2, fabricated by electron beam lithography and standard...... silicon processing. Using a microgripper they were detached from an array and fixed to a standard pyramidal AFM probe or alternatively inserted into a tipless cantilever equipped with a narrow slit. The nanobit-enhanced probes were used for imaging of deep trenches, without visible deformation, wear...... or dislocation of the tips of the nanobit after several scans. This approach allows an unprecedented freedom in adapting the shape and size of scanning probe tips to the surface topology or to the specific application....

  6. Homoleptic Ce(III) and Ce(IV) Nitroxide Complexes: Significant Stabilization of the 4+ Oxidation State

    Energy Technology Data Exchange (ETDEWEB)

    Bogart, Justin A.; Lewis, Andrew J.; Medling, Scott A.; Piro, Nicholas A.; Carroll, Patrick J.; Booth, Corwin H.; Schelter, Eric J.


    Electrochemical experiments performed on the complex Ce-IV[2-((BuNO)-Bu-t)py](4), where [2-((BuNO)-Bu-t)py](-) = N-tert-butyl-N-2-pyridylnitroxide, indicate a 2.51 V stabilization of the 4+ oxidation state of Ce compared to [(Bu4N)-Bu-n](2)[Ce(NO3)(6)] in acetonitrile and a 2.95 V stabilization compared to the standard potential for the ion under aqueous conditions. Density functional theory calculations suggest that this preference for the higher oxidation state is a result of the tetrakis(nitroxide) ligand framework at the Ce cation, which allows for effective electron donation into, and partial covalent overlap with, vacant 4f orbitals with delta symmetry. The results speak to the behavior of CeO2 and related solid solutions in oxygen uptake and transport applications, in particular an inherent local character of bonding that stabilizes the 4+ oxidation state. The results indicate a cerium(IV) complex that has been stabilized to an unprecedented degree through tuning of its ligand-field environment.

  7. Exploring Ce3+/Ce4+ cation ordering in reduced ceria nanoparticles using interionic-potential and density-functional calculations. (United States)

    Migani, Annapaola; Neyman, Konstantin M; Illas, Francesc; Bromley, Stefan T


    The performance of atomistic calculations using interionic potentials has been examined in detail with respect to the structures and energetic stabilities of ten configurational isomers (i.e., distinct Ce3+/Ce4+ cationic orderings) of a low energy octahedral ceria nanoparticle Ce19O32. The outcome of these calculations is compared with the results of corresponding density-functional (DF) calculations employing local and gradient corrected functionals with an additional corrective onsite Coulombic interaction applied to the f-electrons (i.e., LDA+U and GGA+U, respectively). Strikingly similar relative energy ordering of the isomers and atomic scale structural trends (e.g., cation-cation distances) are obtained in both the DF and interionic-potential calculations. The surprisingly good agreement between the DF electronic structure calculations and the relatively simple classical potentials is not found to be due to a single dominant interaction type but is due to a sensitive balance between long range electrostatics and local bonding contributions to the energy. Considering the relatively high computational cost and technical difficulty involved in obtaining charge-localized electronic solutions for reduced ceria using DF calculations, the use of interionic potentials for rapid and reliable preselection of the most stable Ce3+/Ce4+ cationic orderings is of considerable benefit.

  8. Probe microphone measurements: 20 years of progress. (United States)

    Mueller, H G


    ), which eliminated the need to place the microphone itself in the ear canal. By early 1985, three or four different manufactures had introduced this new type of computerized probe-microphone equipment, and this hearing aid verification procedure became part of the standard protocol for many audiology clinics. At his time, the POGO (Prescription Of Gain and Output) and Libby 1/3 prescriptive fitting methods were at the peak of their popularity, and a revised NAL (National Acoustic Laboratories) procedure was just being introduced. All three of these methods were based on functional gain, but insertion gain easily could be substituted, and therefore, manufacturers included calculation of these prescriptive targets as part of the probe-microphone equipment software. Audiologists, frustrated with the tedious and unreliable functional gain procedure they had been using, soon developed a fascination with matching real-ear results to prescriptive targets on a computer monitor. In some ways, not a lot has changed since those early days of probe-microphone measurements. Most people who use this equipment simply run a gain curve for a couple inputs and see if it's close to prescriptive target-something that could be accomplished using the equipment from 1985. Contrary to the predictions of many, probe-mic measures have not become the "standard hearing aid verification procedure." (Mueller and Strouse, 1995). There also has been little or no increase in the use of this equipment in recent years. In 1998, I reported on a survey that was conducted by The Hearing Journal regarding the use of probe-microphone measures (Mueller, 1998). We first looked at what percent of people dispensing hearing aids own (or have immediate access to) probe-microphone equipment. Our results showed that 23% of hearing instrument specialists and 75% of audiologists have this equipment. Among audiologists, ownership varied among work settings: 91% for hospitals/clinics, 73% for audiologists working for

  9. Transnationalism and integration : complements or Substitutes?

    NARCIS (Netherlands)

    Dekker, B.; Siegel, M.


    This paper investigates the relationship between transnational practices and integration by testing whether they are substitutes or complements. For this purpose, we use a multidimensional transnationalism index. The index includes three dimensions of transnational practices, including migrants'

  10. Questioning nuclear waste substitution: a case study. (United States)

    Marshall, Alan


    This article looks at the ethical quandaries, and their social and political context, which emerge as a result of international nuclear waste substitution. In particular it addresses the dilemmas inherent within the proposed return of nuclear waste owned by Japanese nuclear companies and currently stored in the United Kingdom. The UK company responsible for this waste, British Nuclear Fuels Limited (BNFL), wish to substitute this high volume intermediate-level Japanese-owned radioactive waste for a much lower volume of much more highly radioactive waste. Special focus is given to ethical problems that they, and the UK government, have not wished to address as they move forward with waste substitution. The conclusion is that waste substitution can only be considered an ethical practice if a set of moderating conditions are observed by all parties. These conditions are listed and, as of yet, they are not being observed.


    Directory of Open Access Journals (Sweden)

    Hisao Kumamoto


    Full Text Available This study investigates the impacts of the degree of currency substitution on nominal exchange rate volatility in seven countries (Indonesia, the Philippines, the Czech Republic, Hungary, Poland, Argentina, and Peru. We use the Threshold ARCH model to consider the ratchet effect of currency substitution and sample periods in the 2000s, during which time the economies of the sample countries stabilized, while the U.S. dollar and euro depreciated against other major currencies following the recent global financial crisis. The presented empirical analyses show that the degree of currency substitution has significant positive effects on the conditional variance of the depreciation rate of the nominal exchange rate in most sample countries. Moreover, a shock to the depreciation rate of the nominal exchange rate has asymmetric effects on the conditional variance, depending on the sign. One possible explanation for these differential effects is the existence of the ratchet effect of currency substitution.

  12. Synthesis of substituted 2-cyanoarylboronic esters

    DEFF Research Database (Denmark)

    Lysén, Morten; Hansen, Henriette M; Begtrup, Mikael


    The synthesis of substituted 2-cyanoarylboronic esters is described via lithiation/in situ trapping of the corresponding methoxy-, trifluoromethyl-, fluoro-, chloro-, and bromobenzonitriles. The crude arylboronic esters were obtained in high yields and purities and with good regioselectivities....

  13. Approximate substitutions and the normal ordering problem

    Energy Technology Data Exchange (ETDEWEB)

    Cheballah, H; Duchamp, G H E [Universite Paris 13 Laboratoire d' Informatique Paris Nord, CNRS UMR 7030 99 Av. J-B. Clement, F 93430 Villetaneuse (France); Penson, K A [Laboratoire de Physique Theorique de la Matiere Condensee Universite Pierre et Marie Curie, CNRS UMR 7600 Tour 24 - 2e et., 4 pl. Jussieu, F 75252 Paris Cedex 05 (France)], E-mail:, E-mail:, E-mail:


    In this paper, we show that the infinite generalised Stirling matrices associated with boson strings with one annihilation operator are projective limits of approximate substitutions, the latter being characterised by a finite set of algebraic equations.


    NARCIS (Netherlands)



    Cyclophosphazene-substituted siloxanes and silanes are prepared by the method of hydrosilylation, starting from allyl-derivatized cyclophosphazenes and hydrosiloxanes or hydrosilanes in the presence of a platinum catalyst. Steric and electronic effects govern the course of the reaction.

  15. Substitution within the Danish printing industry

    DEFF Research Database (Denmark)

    Larsen, Henrik Fred; Bøg, Carsten


    The implementation of the EU REACH regulation will most probably promote substitution within sectors handling a lot of different chemicals like the printing industry. With the aim of being at the cutting edge of this development the Danish EPA together with the Danish printing industry and IPU...... are running a substitution project. A major part of the work has been mapping the presence of chemicals which are potential candidates for substitution (e.g. PBT, CMR, vPvB, EDS) within the Danish printing industry and this work was recently finished. The mapping comprises a combination of a literature study...... and an investigation of the actual (2007) presence of candidate substances at 15 Danish printing houses including the examination of almost 900 MSDS’s (i.e. products). Furthermore, a focused search in the Danish Product Register has been included. More than 150 of the mapped substances are candidates for substitution...


    African Journals Online (AJOL)


    en)yl-substituted phenolic moiety. Alongside this compilation, a diagnostic discussion is presented aiming at pinpointing CNSL phenols as prospective precursors for the semisyntheses of some selected natural products as illustrative examples.

  17. substitution line for resistance to stripe rust

    Indian Academy of Sciences (India)


    2D) substitution line for resistance to stripe rust. MENGPING LEI, GUANGRONG LI, SUFEN ZHANG, CHENG LIU and ZUJUN YANG. ∗. School of Life Science and Technology, University of Electronic Science and Technology ...


    African Journals Online (AJOL)


    substituted polythiophenes were studied. The pristine polymers, upon dissolution in chloroform, exhibited blue-shifted absorption. The solid films of the polymers showed significant blue-shifted as well as red-shifted absorptions when heated.

  19. The application of the seam beam VLBI technique for the orbit determination of CE-5 in the rendezvous and docking phase (United States)

    Huang, Yong


    CE-5 will be launched in 2017-2018, and it is a lunar sample return mission. It is the first time for China to carry out the rendezvous and docking in the Moon. How to achieve rendezvous and docking successfully in the Moon is very important for CE-5 project. When the ascender is about 70 km farer away from the orbiter, the ground based tracking technique including range, Doppler and VLBI will be used to track the orbiter and the ascender. Later the ascender will approach the orbiter automatically. Here the application of the same beam VLBI for the orbit determination of the orbiter and the ascender in the long range of the rendezvous and docking phase is discussed. The same beam VLBI technique can be used to track the orbiter and the ascender simultaneously when they are in the same beam. Delta delay of the two probes can be derived, and the measurement accuracy is much higher than the traditional VLBI data because of the cancelation of common errors. Theoretically it can result in more accurate relative orbit between the two probes. The simulation results show that the relative position accuracy of the orbiter and ascender can reach about 1 m in CE-5 project with delta delay data of 10 ps.

  20. Atomic transition probabilities of Ce I from Fourier transform spectra (United States)

    Lawler, J. E.; Chisholm, J.; Nitz, D. E.; Wood, M. P.; Sobeck, J.; Den Hartog, E. A.


    Atomic transition probabilities for 2874 lines of the first spectrum of cerium (Ce I) are reported. These data are from new branching fraction measurements on Fourier transform spectra normalized with previously reported radiative lifetimes from time-resolved laser-induced-fluorescence measurements (Den Hartog et al 2009 J. Phys. B: At. Mol. Opt. Phys. 42 085006). The wavelength range of the data set is from 360 to 1500 nm. Comparisons are made to previous investigations which are less extensive. Accurate Ce i transition probabilities are needed for lighting research and development on metal halide high-intensity discharge lamps.

  1. CePtSi: A new heavy-fermion compound

    Energy Technology Data Exchange (ETDEWEB)

    Lee, W.H.; Shelton, R.N.


    We find that CePtSi is a new heavy-fermion and coherent dense Kondo-lattice compound with no magnetic or superconducting transition above 70 mK. Measurements of the magnetic contribution to the electrical resistivity, static magnetic susceptibility, and low-temperature heat capacity of CePtSi are reported. This compound has a large value of the low-temperature magnetic susceptibility (chi(2.4 K) = 24.9 x 10/sup -3/ cm/sup 3//mol) and, characteristic of heavy-fermion compounds, an enormous coefficient of the electronic specific heat, ..gamma..approx.800 mJ/molX sup 2: .

  2. Spin-vibrational 1+ states in 140Ce


    Guliyev, E.; Yavas, O.; Kuliev, A. A.


    The properties of collective I^$\\Pi$=1+ states in double even semimagic nucleus 140Ce are investigated in random phase approximation(RPA). The calculation of the B(M1) strength, elastic gamma-scattering cross section $\\sigma_(gamma)(\\omega)$ and gamma-decay width $\\Sigma_(gamma)(\\omega_i)$ show that in 140Ce the isovector spin-spin interactions concenrate the main strength of M1 transition at energy 7.89 MeV where the isovector spin-flip magnetic resonance may appear. The predisctions are con...

  3. Atomic transition probabilities of Ce I from Fourier transform spectra

    Energy Technology Data Exchange (ETDEWEB)

    Lawler, J E; Wood, M P; Den Hartog, E A [Department of Physics, University of Wisconsin, 1150 University Ave., Madison, WI 53706 (United States); Chisholm, J [Department of Physics, Boston College, 140 Commonwealth Ave., Chestnut Hill, MA 02467 (United States); Nitz, D E [Department of Physics, St. Olaf College, 1520 St. Olaf Ave., Northfield, MN 55057 (United States); Sobeck, J, E-mail: jelawler@wisc.ed, E-mail: chishojd@bc.ed, E-mail: nitz@stolaf.ed, E-mail: mpwood@wisc.ed, E-mail: jsobeck@uchicago.ed, E-mail: eadenhar@wisc.ed [Department of Astronomy and Astrophysics, University of Chicago, 5640 Ellis Ave., Chicago, IL 60637 (United States)


    Atomic transition probabilities for 2874 lines of the first spectrum of cerium (Ce I) are reported. These data are from new branching fraction measurements on Fourier transform spectra normalized with previously reported radiative lifetimes from time-resolved laser-induced-fluorescence measurements (Den Hartog et al 2009 J. Phys. B: At. Mol. Opt. Phys. 42 085006). The wavelength range of the data set is from 360 to 1500 nm. Comparisons are made to previous investigations which are less extensive. Accurate Ce i transition probabilities are needed for lighting research and development on metal halide high-intensity discharge lamps.

  4. Mode-locked deep ultraviolet Ce:LiCAF laser. (United States)

    Granados, Eduardo; Coutts, David W; Spence, David J


    We report mode-locked operation of a synchronously pumped Ce:LiCAF oscillator. The laser operated in the deep UV with output radiation centered at 291 nm and a pulse duration of 6 ps. The maximum output power measured was 52 mW, with 13% slope efficiency. The Ce:LiCAF crystal has a gain bandwidth capable of supporting few-femtosecond pulses, and so our results demonstrate the potential to form a new class of ultrafast lasers operating directly at deep UV wavelengths.

  5. Three-Dimensional Structure of CeO2 Nanocrystals

    DEFF Research Database (Denmark)

    Tan, Joyce Pei Ying; Tan, Hui Ru; Boothroyd, Chris


    Visualization of three-dimensional (3D) structures of materials at the nanometer scale can shed important information on the performance of their applications and provide insight into the growth mechanism of shape-controlled nanomaterials. In this paper, the 3D structures and growth pathway of CeO2...... in samples synthesized under different conditions. The homogeneous growth environment in solution with polyvinylpyrrolidone (PVP) molecules led to the formation of regular octahedral CeO2 nanocrystals with small {001} facet truncations. When the PVP surfactant was removed, the aggregation of regular...

  6. Forbidden Synonymous Substitutions in Coding Regions


    Roy J. Britten


    In the evolution of highly conserved genes, a few "synonymous" substitutions at third bases that would not alter the protein sequence are forbidden or very rare, presumably as a result of functional requirements of the gene or the messenger RNA. Another 10% or 20% of codons are significantly less variable by synonymous substitution than are the majority of codons. The changes that occur at the majority of third bases are subject to codon usage restrictions. These usage restrictions control se...

  7. Hyperfine magnetic fields in substituted Finemet alloys

    Energy Technology Data Exchange (ETDEWEB)

    Brzózka, K., E-mail: [University of Technology and Humanities in Radom, Department of Physics (Poland); Sovák, P. [P.J. Šafárik University, Institute of Physics (Slovakia); Szumiata, T.; Gawroński, M.; Górka, B. [University of Technology and Humanities in Radom, Department of Physics (Poland)


    Transmission Mössbauer spectroscopy was used to determine the hyperfine fields of Finemet-type alloys in form of ribbons, substituted alternatively by Mn, Ni, Co, Al, Zn, V or Ge of various concentration. The comparative analysis of magnetic hyperfine fields was carried out which enabled to understand the role of added elements in as-quenched as well as annealed samples. Moreover, the influence of the substitution on the mean direction of the local hyperfine magnetic field was examined.

  8. Enantiospecific Synthesis of β-Substituted Tryptamines. (United States)

    Rubin, Heather N; Van Hecke, Kinney; Mills, Jonathan J; Cockrell, Jennifer; Morgan, Jeremy B


    Functionalized tryptamines are targets of interest for development as small molecule therapeutics. The ring opening of aziridines with indoles is a powerful method for tryptamine synthesis where isomer formation can be controlled. 3,5-Dinitrobenzoyl (DNB)-protected aziridines undergo regioselective, enantiospecific ring opening to produce β-substituted tryptamines for a series of indoles. Attack at the more substituted aziridine carbon occurs in an SN2-like fashion to generate DNB-tryptamine products as synthetic precursors.

  9. Transient Astrophysics Probe (United States)

    Camp, Jordan


    Transient Astrophysics Probe (TAP), selected by NASA for a funded Concept Study, is a wide-field high-energy transient mission proposed for flight starting in the late 2020s. TAP’s main science goals, called out as Frontier Discovery areas in the 2010 Decadal Survey, are time-domain astrophysics and counterparts of gravitational wave (GW) detections. The mission instruments include unique imaging soft X-ray optics that allow ~500 deg2 FoV in each of four separate modules; a high sensitivity, 1 deg2 FoV soft X-ray telescope based on single crystal silicon optics; a passively cooled, 1 deg2 FoV Infrared telescope with bandpass 0.6-3 micron; and a set of ~8 small NaI gamma-ray detectors. TAP will observe many events per year of X-ray transients related to compact objects, including tidal disruptions of stars, supernova shock breakouts, neutron star bursts and superbursts, and high redshift Gamma-Ray Bursts. Perhaps most exciting is TAP’s capability to observe X-ray and IR counterparts of GWs involving stellar mass black holes detected by LIGO/Virgo, and possibly X-ray counterparts of GWs from supermassive black holes, detected by LISA and Pulsar Timing Arrays.

  10. Study of the magnetic properties of CeCu{sub 2}(Si{sub 1-x}Ge{sub x}){sub 2} by means of neutron scattering; Untersuchung der magnetischen Eigenschaften von CeCu{sub 2}(Si{sub 1-x}Ge{sub x}){sub 2} mittels Neutronenstreuung

    Energy Technology Data Exchange (ETDEWEB)

    Faulhaber, Enrico


    In 1979 the first heavy-fermion superconductor CeCu{sub 2}Si{sub 2} was discovered by Steglich et al. The system is near a quantum critical point (QCP), where the magnetic order is just suppressed. The distance to the QCP can be varied with hydrostatic pressure as well as by germanium substitution on the silicon site. Next to the superconductivity in CeCu{sub 2}Si{sub 2} one finds distinct magnetic phases while increasing the germanium content. CeCu{sub 2}Si{sub 2} shows a magnetic order of a spin-density-type below T{sub N}-0.8 K, whereas the heavy fermion system CeCu{sub 2}Ge{sub 2} orders below T{sub N}=4.1 K as an antiferromagnet. The focus of this thesis is on neutron-diffraction in the system CeCu{sub 2}(Si{sub 1-x}Ge{sub x}){sub 2}. Starting with a sample with a high germanium content of x=0.45, the magnetic structures are investigated in detail. Following a step-by-step approach, samples with reduced x are investigated subsequently to figure out the properties of pure CeCu{sub 2}Si{sub 2}, which were not accessible before. Furthermore, the complex interaction between magnetism and superconductivity is investigated in detail. Using a specially designed setup, the ac-susceptibility could be recorded simultaneously during the neutron diffraction experiments. Due to the direct correlation between antiferromagnetic signals and diamagnetic features, the microscopic coexistence of superconductivity and magnetic order can be ruled out. Instead, a phase separation on the microscopic scale is found. (orig.)

  11. Magnetic properties of Ce3+ in PbCeA (A= Te, Se, S) (United States)

    Isber, S.; Gratens, X.; Charar, S.; Golacki, Z.


    The magnetic susceptibility of Pb1-xCexA (A = S, Se and Te) crystals with 0.006 ≤ x ≤ 0.036 were studied in the temperature range from 20 mK up to room temperature. X-band (~9.5 GHz) Electron Paramagnetic Resonance (EPR) showed small shifts in the effective Landé factors that were attributed to crystal-field admixture. The EPR measurements were correlated with the magnetic susceptibility data and resulted in estimating the crystal-field splitting Δ = E(Γ8) - E(Γ7) of the lowest 2F5/2 manifold for Ce3+ ions in PbA (A = S, Se and Te) of about 340 K, 440 K and 540 K for Pb1-xCexTe, Pb1-xCexSe, and Pb1-xCexS, respectively. The values for the crystal-field splitting deduced from the magnetic data were found to be in agreement with the calculated ones based on the point charge model. Moreover, the deHaas van-Alphen magnetic oscillations in the susceptibility measurements of Pb1-xCexTe (x~ 0.05 and 0.07) were observed at ultra-low temperature (20 mK); The oscillations were investigated and the values of the oscillatory period for Pb1-xCexTe (x = 0.0048 and 0.007) are reported.

  12. Substituting missing data in compositional analysis

    Energy Technology Data Exchange (ETDEWEB)

    Real, Carlos, E-mail: [Area de Ecologia, Departamento de Biologia Celular y Ecologia, Escuela Politecnica Superior, Universidad de Santiago de Compostela, 27002 Lugo (Spain); Angel Fernandez, J.; Aboal, Jesus R.; Carballeira, Alejo [Area de Ecologia, Departamento de Biologia Celular y Ecologia, Facultad de Biologia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain)


    Multivariate analysis of environmental data sets requires the absence of missing values or their substitution by small values. However, if the data is transformed logarithmically prior to the analysis, this solution cannot be applied because the logarithm of a small value might become an outlier. Several methods for substituting the missing values can be found in the literature although none of them guarantees that no distortion of the structure of the data set is produced. We propose a method for the assessment of these distortions which can be used for deciding whether to retain or not the samples or variables containing missing values and for the investigation of the performance of different substitution techniques. The method analyzes the structure of the distances among samples using Mantel tests. We present an application of the method to PCDD/F data measured in samples of terrestrial moss as part of a biomonitoring study. - Highlights: > Missing values in multivariate data sets must be substituted prior to analysis. > The substituted values can modify the structure of the data set. > We developed a method to estimate the magnitude of the alterations. > The method is simple and based on the Mantel test. > The method allowed the identification of problematic variables in a sample data set. - A method is presented for the assessment of the possible distortions in multivariate analysis caused by the substitution of missing values.

  13. Fabrication and characterization of spark plasma sintered Ce:LuAG ceramic for scintillation application

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. Arun; Senthilselvan, J., E-mail: [Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai–600 025, Tamil Nadu (India)


    Rare earth Cerium doped Lutetium Aluminum Garnet (Ce:LuAG) ceramics are widely used as phosphor material in medical imaging and high-energy physics. Due to its technological importance, an attempt has been made to fabricate Ce:LuAG ceramics by using spark plasma sintering (SPS) technique. XRD patterns of SPS sintered Ce:LuAG ceramics reveals a mixed LuAG and CeO{sub 2} (antisite defect) phases. The microstructures of SPS sintered Ce:LuAG ceramics shows limited densification, inappropriate compaction of particles and existence of residual pores, voids between the grain boundaries affects the transparency of Ce:LuAG ceramics. Relative density and hardness of post sintered Ce:LuAG ceramic is also determined. The effect of Ce{sup 3+} doping concentration and sintering temperature on optical luminescence behavior of Ce:LuAG ceramic is presented.

  14. Preparation and characterization of p–n heterojunction CuBi2O4/CeO2 and its photocatalytic activities under UVA light irradiation

    Directory of Open Access Journals (Sweden)

    Abdelkader Elaziouti


    Full Text Available CuBi2O4/CeO2 nanocomposites were synthesized by the solid state method and were characterized by a number of techniques such as X-ray diffraction, scanning electron microscopy and UV–Vis diffuse reflectance spectroscopy. The photocatalytic activity of the samples was investigated under UVA light and assessed using Congo red (CR dye as probe reaction. The efficiency of the coupled CuBi2O4/CeO2 photocatalyst was found to be related to the amount of added CuBi2O4 and to the pH medium. The CuBi2O4/CeO2 photocatalyst exhibited the high efficiency as a result of 83.05% of degradation of CR under UVA light for 100 min of irradiation time with 30 wt% of CuBi2O4 at 25 °C and pH 7, which is about 6 times higher than that of CeO2. The photodegradation reactions satisfactorily correlated with the pseudo-first-order kinetic model. The mechanism of the enhanced photocatalytic efficiency was explained by the heterojunction model.

  15. Some observations on the synthesis and electrolytic properties of (Ba1-xCax (M0.9Y0.1O3, M = Ce, Zr-based samples modified with calcium

    Directory of Open Access Journals (Sweden)

    Dudek Magdalena


    Full Text Available In this paper, the impact of partial substitution of calcium for barium in (Ba1-xCax (M0.9Y0.1 O3, M = Ce, Zr on physicochemical properties of the powders and sintered samples was investigated. The powders, with various contents of calcium (x = 0, 0.02, 0.05, 0.1, were prepared by means of thermal decomposition of organometallic precursors containing EDTA. All of the BaCeO3-based powders synthesised at 1100 °C were monophasic with a rhombohedral structure, however, completely cubic BaZrO3-based solid solutions were obtained at 1200 °C. A study of the sinterability of BaZr0.9Y0.1O3 and BaCe0.9Y0.1O3-based pellets was performed under non-isothermal conditions within a temperature range of 25 to 1200 °C. The partial substitution of barium for calcium in the (Ba1-xCax (M0.9Y0.1 O3, M = Ce, Zr solid solution improved the sinterability of the samples in comparison to the initial BaCe0.9Y0.1O3 or BaZr0.9Y0.1O3. The relative density of calcium-modified BaCe0.9Y0.1O3-based samples reached approximately 95 to 97 % after sintering at 1500 °C for 2 h in air. The same level of relative density was achieved after sintering calcium-modified BaZr0.9Y0.1O3 at 1600 °C for 2 h. Analysis of the electrical conductivity from both series of investigated materials showed that the highest ionic conductivity, in air and wet 5 % H2 in Ar, was attained for the compositions of x = 0.02 to 0.05 (Ba1-xCax(M0.9Y0.1O3, M = Zr, Ce. The oxygen reduction reaction on the interface Pt│BaM0.9Y0.1O3, M = Ce, Zr was investigated using Pt microelectrodes. Selected samples of (Ba1-xCax (M0.9Y0.1O3, M = Zr, Ce were tested as ceramic electrolytes in hydrogen-oxygen solid oxide fuel cells operating at temperatures of 700 to 850 °C.

  16. Enhanced catalytic properties of La-doped CeO2 nanopowders synthesized by hydrolyzing and oxidizing Ce46La5C49 alloys

    Directory of Open Access Journals (Sweden)

    Xueling Hou


    Full Text Available The Ce46La5C49 alloy was first prepared in a 25 kg vacuum induction melting furnace. The La-doped CeO2 nanopowders were then prepared by hydrolysis and oxidation of Ce46La5C49 at room temperature. These nanopowders were calcinated at different temperatures in order to improve their catalytic activities. The lanthanum ions were used to partially replace the cerium ions in the CeO2 lattice, forming a solid solution of cerium lanthanum. Compared to the pure CeO2, the thermal stability of La-doped CeO2 was increased due to the lanthanum doping. The La-doped CeO2 nanopowders show enhanced CH4 catalytic performance.

  17. Easy peak tracking in CE-UV and CE-UV-ESI-MS by incorporating temperature-correlated mobility scaling

    DEFF Research Database (Denmark)

    Li, Bin; Petersen, Nickolaj Jacob; Andersen, Line Hvass


    A simple data reconstruction technique in capillary electrophoresis - ultraviolet - electrospray ionization - mass spectrometry (CE-UV-ESI-MS) is presented to overcome the drift in mobilities caused by various factors compromising the reproducibility of such data, e.g. Joule heating effects...... and the variation in thermostatic control along the capillary, drift in electroosmotic flow (EOF) and the suction effect caused by the nebulizing gas in coaxial CE-MS interfaces. We present here a method to transform the traditional time-based electropherogram into the corresponding temperature-correlated mobility...

  18. The CO-2CeO2 interaction and its role in the CeO2 reactivity


    Appel, Lúcia Gorenstin; Eon, Jean G.; Schmal,Martin


    The interaction between CO2 and Ce02 and its role in thc sutface reactivity of alumina-supported cerium oxide has been studied by programmed thermodesorption (TPO) of CO2 and FTIR spectroscopy. The petfomlance of eel Al203 systems was then analyzed for the propane oxidation in presence of CO2. The results have shown that the catalytic activity decreased when carbonate species are formed at the sutface of Ce02. This behavior was attributed to the presence of CO2 from three different sour...

  19. Low toxicity binder systems for tape cast Ce0.9Gd0.1O1.95 laminates

    DEFF Research Database (Denmark)

    Klemensø, Trine; Menon, Mohan; Ramousse, Severine


    Conventional binder systems for tape casting contain toxic phthalate plasticizers and butanone (MEK) as part of the solvent. The effects of exchanging the phthalate with a non-toxic alternative, and butanone with ethanol, were studied on laminates of high-green density CGO (Ce0.9Gd0.1O1.95) tapes....... Samples were prepared with a binder system containing DBP (dibutyl phthalate) plasticizer and MEK solvent, and with a binder system based on a non-toxic non-phthalate plasticizer and ethanol. In both systems, the weight ratio of plasticizer to the PVB (polyvinyl butyral) binder was varied between 0.......4 and 0.7. Substitution to the less toxic binder system had no adverse impacts on the microstructure. In fact, denser packing and improved homogeneity were observed with the non-phthalate-based system at ratio 0.5 indicating improved dispersion in this system. The denser packing also coincided...

  20. Genetically Encoded Fluorescent Redox Probes

    Directory of Open Access Journals (Sweden)

    Hui-Wang Ai


    Full Text Available Redox processes are involved in almost every cell of the body as a consequence of aerobic life. In the past decades, redox biology has been increasingly recognized as one of the key themes in cell signaling. The progress has been accelerated by development of fluorescent probes that can monitor redox conditions and dynamics in cells and cell compartments. This short paper focuses on fluorescent redox probes that are genetically encoded, and discusses their properties, molecular mechanism, advantages and pitfalls. Our recent work on reaction-based encoded probes that are responsive to particular redox signaling molecules is also reviewed. Future challenges and directions are also commented.

  1. Genetically encoded fluorescent redox probes. (United States)

    Ren, Wei; Ai, Hui-Wang


    Redox processes are involved in almost every cell of the body as a consequence of aerobic life. In the past decades, redox biology has been increasingly recognized as one of the key themes in cell signaling. The progress has been accelerated by development of fluorescent probes that can monitor redox conditions and dynamics in cells and cell compartments. This short paper focuses on fluorescent redox probes that are genetically encoded, and discusses their properties, molecular mechanism, advantages and pitfalls. Our recent work on reaction-based encoded probes that are responsive to particular redox signaling molecules is also reviewed. Future challenges and directions are also commented.

  2. Optic probe for semiconductor characterization (United States)

    Sopori, Bhushan L [Denver, CO; Hambarian, Artak [Yerevan, AM


    Described herein is an optical probe (120) for use in characterizing surface defects in wafers, such as semiconductor wafers. The optical probe (120) detects laser light reflected from the surface (124) of the wafer (106) within various ranges of angles. Characteristics of defects in the surface (124) of the wafer (106) are determined based on the amount of reflected laser light detected in each of the ranges of angles. Additionally, a wafer characterization system (100) is described that includes the described optical probe (120).

  3. Crystal structure of a new polar borate Na2Ce2[BO2(OH)][BO3]2 · H2O with isolated boron triangles (United States)

    Topnikova, A. P.; Belokoneva, E. L.; Dimitrova, O. V.; Volkov, A. S.


    Crystals of a new polar borate Na2Ce2[BO2(OH)][BO3]2 · H2O were prepared by hydrothermal synthesis. The crystals are orthorhombic, a = 7.2295(7) Å, b = 11.2523(8) Å, c = 5.1285(6) Å, Z = 2, sp. gr. C2 mm ( Amm2), R = 0.0253. The formula of the compound was derived from the structure determination. The Ce and Na atoms are coordinated by nine and six O atoms, respectively. The Ce position is split, and a small amount of Ce is incorporated into the Na1 site with the isomorphous substitution for Na. The anionic moieties exist as isolated BO3 and BO2(OH) triangles. The planes of the BO2(OH) triangles with mm2 symmetry are parallel to the ab plane. The planes of the BO3 triangles with m symmetry are perpendicular to the ab plane and are rotated in a diagonal way. The splitting of the Ce positions and the polar arrangement of the BO2(OH) triangles, water molecules, and Na atoms are observed along the polar a axis. The new structure is most similar to the new borate NaCa4[BO3]3 (sp. gr. Ama2), in which triangles of one type are arranged in a polar fashion along the c axis. Weak nonlinear-optical properties of both polar borates are attributed to the quenching of the second-harmonic generation due to the mutually opposite orientation of two-thirds of B triangles in the unit cell.

  4. [Guidelines for substitution treatments in prison populations]. (United States)

    Michel, L; Maguet, O


    Care access for the drug addict patients in prison (in particular for the treatments of substitution) in France is very unequal from one establishment to another. This reflects the great variability of the practices of substitution and especially the absence of consensus on the methods of adaptation of these practices to the prison environment. Because of difficulties expressed by prisoners and medical staff on this subject and of stakes (let us recall that approximately 30% of the prisoners are dependent or abusers of one or more psychoactive substances), the formulation of recommendations or of a good practices guide of substitution in prison appeared necessary. Work that we detail here answers a ordering of the Advisory Commission of the Treatments of Substitution (September 2001) whose authors are members. It was presented at the session April 2003. It results from the confrontation of a review of the literature (including legal texts and official reports concerning substitution, the organization of the care in prison environment and the lawful framework), with a vast investigation. The latter was carried out near medical staff (22 prisons), penitentiary staff (3 prisons, 27 people met including directors of these establishments) and prisoners (7 establishments, 28 prisoners met) in the form of individual talks (semi-directing interviews with evaluation of the type of existing device and its knowledge by the penitentiary staff and the prisoners; statement of the suggestions, needs and requests of the medical, penitentiary staffs and of the prisoners). In the whole visited prisons, 7.8% (870) of the prisoners received substitution treatments (6.35% by buprenorphine, 1.44% by methadone), representing a proportion of substituted drug addicts (870 substituted for an evaluation of 3,350 prisoners drug addicts among the 11,168 prisoners of the 22 visited prisons) notably lower than that in free environment (56%, ie 96,000 substituted for an evaluated population of

  5. Facile hydrothermal synthesis of CeO2 nanopebbles

    Indian Academy of Sciences (India)


    Ostwald ripening and oriented attachment process, res- pectively. In the hydrothermal process after the nuclea- tion stage, where the small nanocrystals are dissolved or re-precipitated to grow the larger crystals by the Ostwald ripening process, resulting in the formation of CeO2 nanopebbles.24 Figure 2f shows the ...

  6. Neutron scattering from α-Ce at epithermal neutron energies

    Indian Academy of Sciences (India)

    to the neutron spectra which yield parameters that are in good accord with Fermi liquid relations obtained for the ... erties of Ce-based systems is best illustrated with reference to the data on pseudo- binary compounds ..... [11] A P Murani, Z A Bowden, A D Taylor, R Osborn and W G Marshall, Phys. Rev. B48, 13981 (1993).

  7. Commensurate-commensurate magnetic phase transitions in CeSb

    DEFF Research Database (Denmark)

    Lebech, Bente; Broholm, C.; Clausen, K.


    The q=2/3 to q=4/7 commensurate-commensurate phase transition in CeSb has been studied by neutron diffraction. On cooling the commensurate wave vector q changes abruptly from 2/3 to a higher-order commensurate value (≈14/23) at T1

  8. C.E. Carr’s Orchids from Papua

    NARCIS (Netherlands)

    Groves, E.W.


    In order to distribute from the British Museum the remainder of C.E. Carr’s Papua, 1935-36, orchid duplicates it has been necessary first to work out a detailed itinerary of his expedition so as to complete the label data accompanying each specimen. This has been done by reference to the

  9. Implementace OpenVPN na platformě Windows CE


    Ešner, Oldřich


    Motivací pro vznik této diplomové práce, která navazuje na stejnojmenný semestrální projekt, byl převod aplikace pro tvorbu virtuálních privátních sítí OpenVPN z operačního systému Windows XP na platformu Windows CE Embedded 6.0. Práce pojednává obecně o virtuálních privátních sítích, a podrobněji o jedné z jejich implementací - OpenVPN. Uvádí základní vlastnosti operačního systému Windows CE, dále popisuje princip ovladačů zařízení v operačních systémech na bázi Windows NT, používaný Windows...

  10. Magnetic Phase Transitions of CeSb. I

    DEFF Research Database (Denmark)

    Fischer, Pernille Hertz; Lebech, Bente; Meier, G.


    The magnetic ordering of the anomalous antiferromagnet CeSb, which has a NaCl crystal structure, was determined in zero applied magnetic field by means of neutron diffraction investigations of single crystals and powder. Below the Neel temperature TN of (16.1+or-0.1)K, there exist six partially...

  11. Mani (216-276 CE) and Ethiopian Enoch

    National Research Council Canada - National Science Library

    Venter, Pieter M


    .... Introduction Mani (216-276 CE) was the founder of Manichaeism. This religion developed out of the JewishChristian Elchasaite1 group. It spread out to North Africa, Egypt, Central Asia, Oxus in the east, and as far east as China. Mani was a prolific writer. His legacy reflects the circumstances under Sasanian Rule in the east during the 3rd cent...

  12. Itinerant magnetism in CeRh3B2

    DEFF Research Database (Denmark)

    Eriksson, Olle; Johansson, Börje; Brooks, M. S. S.


    Spin-polarized energy-band calculations, including spin-orbit coupling in the band Hamiltonian, have been performed on CeRh3B2. Good agreement is obtained between theory and experiment concerning the magnetic moment. It is also found that the magnetic moment varies strongly with volume and from...

  13. Magnetic domains and frustration in metallic CePdAl

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, Stefan; Huesges, Zita; Huang, Chien-Lung; Stockert, Oliver [Max Planck Institute CPfS, Dresden (Germany); Fritsch, Veronika; Sakai, Akito [EP 6, Electronic Correlations and Magnetism, University of Augsburg (Germany); Grube, Kai; Taubenheim, Christian; Loehneysen, Hilbert von [Karlsruhe Institute of Technology (Germany)


    Magnetic frustration is an exciting topic in condensed matter physics, since it can lead to new ground states of materials, e.g. a spin liquid or spin glass state. Effects of magnetic frustration have been investigated intensively for insulating materials. However, the existence of magnetic frustration in metallic systems is still under debate. CePdAl is a metallic Kondo system, where geometric magnetic frustration arises from the formation of Ce ions on a distorted Kagome lattice. Neutron scattering experiments revealed, that only two thirds of the magnetic Ce moments order antiferromagnetically below T{sub N}=2.7 K, whereas the other third remains mainly disordered. Thermodynamic as well as neutron scattering measurements are presented to verify the existence of partial magnetic frustration in CePdAl. Recently neutron diffraction experiments under magnetic fields applied along two orthogonal directions in the magnetically hard basal plane were performed. They show opposite effects on the magnetic intensity of a selected magnetic domain depending on the field direction with respect to the propagation vector. If this is only an effect of different domain population or also due to a change in magnetic frustration shall be discussed.

  14. A Sesame Equation of State for Dense Ce

    Energy Technology Data Exchange (ETDEWEB)

    Greeff, Carl William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Crockett, Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    We generated a new Sesame equation of state table for Ce. It is a single effective phase table for the high density phases α, α ', ϵ and liquid. Also, the EOS is meant to be used with a ramp to represent the initial low density γ phase.

  15. A rhodamine-labeled citalopram analogue as a high-affinity fluorescent probe for the serotonin transporter

    DEFF Research Database (Denmark)

    Zhang, Peng; Jørgensen, Trine Nygaard; Løland, Claus Juul


    A novel fluorescent ligand was synthesized as a high-affinity, high specificity probe for visualizing the serotonin transporter (SERT). The rhodamine fluorophore was extended from an aniline substitution on the 5-position of the dihydroisobenzofuran ring of citalopram (2, 1-(3-(dimethylamino)prop...

  16. Effect of Ce-doping on the electrical and electrocatalytical behavior of La/Sr chromo-manganite perovskite as new SOFC anode

    Energy Technology Data Exchange (ETDEWEB)

    Lay, E. [CEA, LITEN, Laboratoire d' Innovation Technologique et des Energies Nouvelles, 17 rue des Martyrs, 38054 Grenoble (France); LEPMI, Laboratoire d' Electrochimie et de Physico-Chimie des Materiaux et des Interfaces, UMR 5279, CNRS - Grenoble INP - Universite de Savoie - Universite Joseph Fourier, BP75, 38402 Saint Martin d' Heres (France); Benamira, M.; Pirovano, C. [Universite Lille Nord de France, UMR CNRS 8181, Unite de Catalyse et de Chimie du Solide, ENSCL, 59652 Villeneuve d' Ascq cedex (France); Gauthier, G. [CEA, LITEN, Laboratoire d' Innovation Technologique et des Energies Nouvelles, 17 rue des Martyrs, 38054 Grenoble (France); Dessemond, L. [LEPMI, Laboratoire d' Electrochimie et de Physico-Chimie des Materiaux et des Interfaces, UMR 5279, CNRS - Grenoble INP - Universite de Savoie - Universite Joseph Fourier, BP75, 38402 Saint Martin d' Heres (France)


    The effect of cerium substitution on the electrical and electrochemical characteristics of a new anode material La{sub 0.75}Sr{sub 0.25}Cr{sub 0.5}Mn{sub 0.5}O{sub 3} (LSCM) was examined by synthesizing Ce{sub x}La{sub 0.75-x}Sr{sub 0.25}Cr{sub 0.5}Mn{sub 0.5}O{sub 3} for x = (0-0.375). From x = 0-0.25, the structure is rhombohedral (S.G. R-3c), and with a higher cerium content (x = 0.375) it becomes cubic (S.G. Pm-3m). These materials are stable in the operating conditions of an SOFC anode. Ce{sub x}La{sub 0.75-x}Sr{sub 0.25}Cr{sub 0.5}Mn{sub 0.5}O{sub 3} and LSCM materials are p-type semi-conductors. Cerium substitution improves the conductivity in neutral atmosphere from 18.3 to 35.4 S cm{sup -1} for x = 0 and 0.375, respectively, at 1,173 K. In reducing conditions, the conductivity is not influenced by cerium substitution, and it is about 1 S cm{sup -1} at 1,173 K. High temperature XRD shows that structure becomes cubic at 1,073 K in operating (reducing) conditions. Cerium substitution positively enhances the electrochemical behavior, as proved by studying the properties of dense cone-shaped electrodes. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Magnetic properties of Ce3+ in PbCeA (A= Te, Se, S

    Directory of Open Access Journals (Sweden)

    Golacki Z.


    Full Text Available The magnetic susceptibility of Pb1-xCexA (A = S, Se and Te crystals with 0.006 ≤  x ≤ 0.036  were studied in the temperature range from 20 mK up to room temperature. X-band (~9.5 GHz Electron Paramagnetic Resonance (EPR showed small shifts in the effective Landé factors that were attributed to crystal-field admixture. The EPR measurements were correlated with the magnetic susceptibility data and resulted in estimating the crystal-field splitting Δ = E(Γ8 - E(Γ7 of the lowest 2F5/2 manifold for Ce3+ ions in PbA (A = S, Se and Te of about 340 K, 440 K and 540 K for Pb1-xCexTe, Pb1-xCexSe, and Pb1-xCexS, respectively. The values for the crystal-field splitting deduced from the magnetic data were found to be in agreement with the calculated ones based on the point charge model. Moreover, the deHaas van-Alphen magnetic oscillations in the susceptibility measurements of Pb1-xCexTe (x~ 0.05 and 0.07 were observed at ultra-low temperature (20 mK; The oscillations were investigated and the values of the oscillatory period for Pb1-xCexTe (x = 0.0048 and 0.007 are reported.

  18. POLLiCE (POLLen in the iCE): climate history from Adamello ice cores (United States)

    Cristofori, Antonella; Festi, Daniela; Maggi, Valter; Casarotto, Christian; Bertoni, Elena; Vernesi, Cristiano


    Glaciers can be viewed as the most complete and effective past climate and environment archives severely threatened by climate change. These threats are particularly dramatic across European Alps. The Adamello glacier is the largest, 16.4 km2, and deepest, 270 m, Italian glacier. We aim at estimating biodiversity changes over the last centuries in relation to climate and human activities in the Adamello catchment area. We, therefore, recently launched the POLLiCE project ( for specifically targeting the biological component (e.g. pollen, leaves, plant remains) trapped in ice cores. Classical morphological pollen analysis will be accompanied by DNA metabarcoding. This approach has the potential to provide a detailed taxonomical identification - at least genus level- thus circumventing the limitations of microscopic analysis such as time-consuming procedures and shared features of pollen grains among different taxa. Moreover, ice cores are subjected to chemical and physical analyses - stable isotopes, ions, hyperspectral imaging, etc.- for stratigraphic and climatic determination of seasonality. A pilot drilling was conducted on March 2015 and the resulting 5 m core has been analysed in terms of pollen spectrum, stable isotopes and ions in order to demonstrate the feasibility of the study. The first encouraging results showed that even in this superficial core a stratigraphy is evident with indication of seasonality as highlighted by both by pollen taxa and stable isotopes. Finally, DNA has been successfully extracted and amplified with specific DNA barcodes. A medium drilling was performed on April 2016 with the extraction of a 45 m ice core. The analysis of this core constitutes the subject of a specific research project, CALICE*, just funded by Euregio Science Fund (IPN57). The entire depth, 270 m, of the Adamello glacier is scheduled to be drilled in 2018 winter to secure the unique memory archived by the ice. * See EGU2017 poster by Festi et al

  19. Synthesis and characterization of Ba{sub 0.6}Sr{sub 0.4}Ce{sub 0.8−x}Zr{sub x}Y{sub 0.2}O{sub 3−δ} proton-conducting oxides for use as fuel cell electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sheng-Wei [Institute of Materials Science and Engineering, National Central University, Taiwan (China); Tseng, Chung-Jen [Department of Mechanical Engineering, National Central University, Taiwan (China); Chang, Jeng-Kuei, E-mail: [Institute of Materials Science and Engineering, National Central University, Taiwan (China); Department of Mechanical Engineering, National Central University, Taiwan (China); Lee, Kan-Rong [Department of Mechanical Engineering, National Central University, Taiwan (China); Chen, Chia-Tzu [Institute of Materials Science and Engineering, National Central University, Taiwan (China); Hung, I-Ming [Department of Chemical Engineering and Materials Science, Yuan Ze University, Taiwan (China); Lee, Sheng-Long; Lin, Jing-Chie [Institute of Materials Science and Engineering, National Central University, Taiwan (China)


    Highlights: • The proton-conducting oxides are successfully prepared using a sol–gel process. • Increasing the Zr content causes lattice constriction of the perovskite structure. • Increasing the Ce/Zr ratio in the oxides increased ionic conductivity. • The Zr-free Ba{sub 0.6}Sr{sub 0.4}Ce{sub 0.8}Y{sub 0.2}O{sub 3−δ} is unstable in a CO{sub 2} atmosphere at 600 °C. • Suitable substitution of Ce with Zr greatly improves the oxide chemical stability. -- Abstract: Ba{sub 0.6}Sr{sub 0.4}Ce{sub 0.8−x}Zr{sub x}Y{sub 0.2}O{sub 3−δ} (x = 0–0.8) proton-conducting oxides are prepared using a sol–gel complexing process. The effects of the Ce/Zr ratio on various material properties are systematically investigated. The sintered samples show a perovskite crystal structure without impurity phases and have a rather compact interior, making them suitable for use as a fuel cell electrolyte. Increasing the Zr content in the oxides causes lattice constriction and suppresses grain growth during sintering at 1600 °C. The ionic conductivity of the oxides increases with increasing Ce/Zr ratio. At 800 °C, Ba{sub 0.6}Sr{sub 0.4}Ce{sub 0.8}Y{sub 0.2}O{sub 3−δ} has a conductivity of as high as 0.14 S/cm. However, X-ray diffraction and Raman spectroscopy evaluations show that this oxide cannot withstand a CO{sub 2} atmosphere. A suitable substitution of Ce with Zr in the structure significantly improves the chemical stability of the oxide without significantly degrading conductivity.

  20. Feasibility of a wireless gammar probe in radioguided surgery

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hye Min; Kim, Jeong Ho; Park, Chan Jong; Joo, Koan Sik [Dept. of Physics, University of Myongji, Seoul (Korea, Republic of)


    Nuclear medicine is divided into two major domains: diagnosis and therapy. Nuclear medicine diagnostic procedures are used for determining and evaluating the physiological, chemical, endocrinal, and metabolic conditions of organs or tissues. Tumors can be diagnosed based on the images provided by the associated machinery; after diagnosis, sometimes these tumors can be surgically removed. Currently, to help guide the surgeon to the exact location of the tumor site, the use of intraoperative probes has steadily gained popularity. These probes allow the physician to locate the tumor on the basis of the higher uptake of the preoperatively injected radio pharmaceutical within the site, as compared to the surrounding tissue. Direct detection offers very good energy resolution, but the detection efficiency is low; on the other hand, indirect detection presents high efficiency and low energy resolution. For this reason, the use of both detectors is recommended for obtaining an accurate localization of the diagnostic and therapeutic fields. In the literature, there are several works that aim to develop a suitable probe that presents such characteristics (i.e., good resolution, high detection efficiency, as well as the capacity for miniaturization). In this study, a wireless gamma probe is designed for the detection of tumors of the tissue surface using a silicon photomultiplier (SiPM) and a cerium-doped gadolinium aluminum gallium garnet (Ce:GAGG) scintillator. Our experiments demonstrate the feasibility of wireless diagnostics, as well as the suitable energy resolution and spatial resolution. The system developed based on the results of this study is expected to perform intraoperative or diagnostic evaluations of residual lesions (or the absence thereof) and its quantitative distribution in the affected area, thus contributing to wireless diagnostics and screening systems.

  1. Density of molten salt Mixtures of eutectic LiCl-KCl containing UCl{sub 3}, CeCl{sub 3}, or LaCl{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, C.; Simpson, M. F. [Dept. of Metallurgical Engineering, University of Utah, Salt Lake City (United States)


    Densities of molten salt mixtures of eutectic LiCl-KCl with UCl{sub 3}, CeCl{sub 3}, or LaCl{sub 3} at various concentrations (up to 13 wt%) were measured using a liquid surface displacement probe. Linear relationships between the mixture density and the concentration of the added salt were observed. For LaCl{sub 3} and CeCl{sub 3}, the measured densities were signifcantly higher than those previously reported from Archimedes’ method. In the case of LiCl-KCl-UCl{sub 3}, the data ft the ideal mixture density model very well. For the other salts, the measured densities exceeded the ideal model prediction by about 2%.

  2. Tunneling spectroscopy using a probe qubit (United States)

    Berkley, A. J.; Przybysz, A. J.; Lanting, T.; Harris, R.; Dickson, N.; Altomare, F.; Amin, M. H.; Bunyk, P.; Enderud, C.; Hoskinson, E.; Johnson, M. W.; Ladizinsky, E.; Neufeld, R.; Rich, C.; Smirnov, A. Yu.; Tolkacheva, E.; Uchaikin, S.; Wilson, A. B.


    We describe a quantum tunneling spectroscopy technique that requires only low-bandwidth control. The method involves coupling a probe qubit to the system under study to create a localized probe state. The energy of the probe state is then scanned with respect to the unperturbed energy levels of the probed system. Incoherent tunneling transitions that flip the state of the probe qubit occur when the energy bias of the probe is close to an eigenenergy of the probed system. Monitoring these transitions allows the reconstruction of the probed system eigenspectrum. We demonstrate this method on an rf SQUID flux qubit.

  3. A Sequential and Comprehensive Method for Effective Substitute Teaching (United States)

    Byer, John L.


    This article dealt with methods for making substitute teaching more effective. The purpose was to articulate a sequential method for maximizing the effectiveness of substitute teaching while providing substitutes with a comprehensive method for diligently and flexibly earning respect and using reflection to continually improve substitute teaching.…

  4. 12 CFR 229.52 - Substitute check warranties. (United States)


    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Substitute check warranties. 229.52 Section 229... SYSTEM AVAILABILITY OF FUNDS AND COLLECTION OF CHECKS (REGULATION CC) Substitute Checks § 229.52 Substitute check warranties. (a) Content and provision of substitute check warranties. A bank that transfers...

  5. 12 CFR 229.51 - General provisions governing substitute checks. (United States)


    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false General provisions governing substitute checks... FEDERAL RESERVE SYSTEM AVAILABILITY OF FUNDS AND COLLECTION OF CHECKS (REGULATION CC) Substitute Checks § 229.51 General provisions governing substitute checks. (a) Legal equivalence. A substitute check for...

  6. 12 CFR 229.53 - Substitute check indemnity. (United States)


    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Substitute check indemnity. 229.53 Section 229... SYSTEM AVAILABILITY OF FUNDS AND COLLECTION OF CHECKS (REGULATION CC) Substitute Checks § 229.53 Substitute check indemnity. (a) Scope of indemnity. A bank that transfers, presents, or returns a substitute...

  7. A three dimensional probe positioner. (United States)

    Intrator, T; Sun, X; Dorf, L; Furno, I; Lapenta, G


    In order to sort out the physics that is important in many plasma experiments, data in three dimensions (3D) are becoming necessary. Access to the usual cylindrical vacuum vessel is typically restricted to radially or axially insertable probes that can pivot. The space that can be explored usually has significant restrictions either because probe travel must be along a travel path, or a "wobbly" probe positioner requires one to map between a moveable coordinate system and a preferred laboratory coordinate system. This could for example introduce errors in measurements of vector quantities such as magnetic field or flow. We describe the design and implementation of a 3D probe positioner that slides in two dimensions on a double O-ring seal and radially inserts along the third dimension. The net result is that a 3D space can be explored in a laboratory Cartesian reference frame.

  8. A three dimensional probe positionera) (United States)

    Intrator, T.; Sun, X.; Dorf, L.; Furno, I.; Lapenta, G.


    In order to sort out the physics that is important in many plasma experiments, data in three dimensions (3D) are becoming necessary. Access to the usual cylindrical vacuum vessel is typically restricted to radially or axially insertable probes that can pivot. The space that can be explored usually has significant restrictions either because probe travel must be along a travel path, or a "wobbly" probe positioner requires one to map between a moveable coordinate system and a preferred laboratory coordinate system. This could for example introduce errors in measurements of vector quantities such as magnetic field or flow. We describe the design and implementation of a 3D probe positioner that slides in two dimensions on a double O-ring seal and radially inserts along the third dimension. The net result is that a 3D space can be explored in a laboratory Cartesian reference frame.

  9. Genetically Encoded Fluorescent Redox Probes


    Hui-Wang Ai; Wei Ren


    Redox processes are involved in almost every cell of the body as a consequence of aerobic life. In the past decades, redox biology has been increasingly recognized as one of the key themes in cell signaling. The progress has been accelerated by development of fluorescent probes that can monitor redox conditions and dynamics in cells and cell compartments. This short paper focuses on fluorescent redox probes that are genetically encoded, and discusses their properties, molecular mechanism, adv...

  10. The navigation of space probes (United States)

    Fliegel, H. F.; Ohandley, D. A.; Zielenbach, J. W.


    A new navigational method combining electronic measurement procedures and celestial mechanics makes it possible to conduct a space probe very close to a desired point in the neighborhood of a remote planet. Approaches for the determination of the position of the space probe in space are discussed, giving attention to the effects of errors in the employed data. The application of the navigational methods in a number of space missions is also considered.

  11. Study of conduction phenomena in indium substituted Mn-Zn nano-ferrites (United States)

    Kumar, Surender; Shinde, Tukaram J.; Vasambekar, Pramod N.


    Nanocrystalline Indium substituted Mn-Zn ferrites were prepared by oxalate coprecipitation technique in combination with microwave heating. X-ray diffraction and scanning electron microscopy was used to study nano-structural parameters such as crystallite size, lattice constant, X-ray density, observed density and morphology of the synthesized nanopowders. The lattice constant, crystallite size and X-ray density increased with increase in Indium concentration. Thermal variation of dc resistivity was studied by two probe method. The resistivity decreased exponentially with increasing Indium concentration and the change of slope of dc resistivity plot was observed at Curie temperature. Small polaron hopping between Fe2+ and Fe3+ ions at octahedral sites was established. Substitution of Indium ions increased the dc resistivity. Differential method was used to study thermoelectric power. Thermo-emf remained constant with increasing temperature; the n-type conduction mechanism and localization of charge carriers at lattice sites due to strong electron-phonon interaction was established.

  12. 40 CFR 721.1555 - Substituted phenyl azo substituted benzenediazonium salt. (United States)


    ... benzenediazonium salt. 721.1555 Section 721.1555 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... generically as a substituted phenyl azo substituted benzenediazonium salt (PMN P-92-652) is subject to... this part apply to this section except as modified by this paragraph. (1) Recordkeeping. Recordkeeping...

  13. 40 CFR 721.8825 - Substituted methylpyridine and substituted 2-phenoxypyridine. (United States)


    ... respirator fit tests for each person required to wear a respirator. (iii) The names and addresses of persons... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted methylpyridine and substituted 2-phenoxypyridine. 721.8825 Section 721.8825 Protection of Environment ENVIRONMENTAL PROTECTION...

  14. Chemical characterization of some substituted hydroxyapatites

    Directory of Open Access Journals (Sweden)

    Ibrahim Doreya


    Full Text Available Abstract Synthetic multi-substituted hydroxyapatite nano powders containing silicon and or carbonate prepared by a wet chemical method. The process parameters are set up to allow the simultaneous substitution of carbonate and silicon ions in the place of phosphorus. The chemical and structural characterizations of the prepared powders are determined with the aid of; XRF, ICP, XRD and FTIR. The results show that, the ion substitution in the crystal lattice of HA caused a change in the unit cell dimensions and affected the degree of crystallization of the produced powders. The apatite formation abilityy of the prepared discs from the synthesized powders is determined by immersing in SBF solution for different periods. The degree of ion release was determined in the obtained solutions. The examined surface of the immersed discs under SEM and analyzed by CDS showed a more dense HA layer than those of un-substituted ones. The HA with the substituted silicon and carbonate ions, showed the highest solubility with greater rate of ion release, compared with carbonate-free powder. All prepared powders took sodium ion from the SBF solution during immersion, which was not recorded before.

  15. Chemical characterization of some substituted hydroxyapatites. (United States)

    Ibrahim, Doreya Mohamed; Mostafa, Amany A; Korowash, Sara Ibrahim


    Synthetic multi-substituted hydroxyapatite nano powders containing silicon and or carbonate prepared by a wet chemical method. The process parameters are set up to allow the simultaneous substitution of carbonate and silicon ions in the place of phosphorus. The chemical and structural characterizations of the prepared powders are determined with the aid of; XRF, ICP, XRD and FTIR. The results show that, the ion substitution in the crystal lattice of HA caused a change in the unit cell dimensions and affected the degree of crystallization of the produced powders. The apatite formation abilityy of the prepared discs from the synthesized powders is determined by immersing in SBF solution for different periods. The degree of ion release was determined in the obtained solutions. The examined surface of the immersed discs under SEM and analyzed by CDS showed a more dense HA layer than those of un-substituted ones. The HA with the substituted silicon and carbonate ions, showed the highest solubility with greater rate of ion release, compared with carbonate-free powder. All prepared powders took sodium ion from the SBF solution during immersion, which was not recorded before.

  16. Non-aqueous CE-MS of cinchona alkaloids - characterizationof a novel CE-ESI-MS interface

    DEFF Research Database (Denmark)

    Hansen, Frederik André; Hansen, Steen Honoré; Petersen, Nickolaj J.

    a submicron fracture in the capillary close the ESI tip. The fracture provides a zero dead volume and excellent conducting properties due to the large amount of ions in the electric double layer. Electric current exceeding the upper limit of CE instrumentation of up to 300 µA can easily be obtained...

  17. A 3-year follow-up of ceria-stabilized zirconia/alumina nanocomposite (Ce-TZP/A) frameworks for fixed dental prostheses. (United States)

    Tanaka, Shinpei; Takaba, Masayuki; Ishiura, Yuichi; Kamimura, Emi; Baba, Kazuyoshi


    Zirconia/alumina nanocomposite stabilized with cerium oxide (Ce-TZP/A) shows significantly higher mechanical strength than yttrium-oxide-partially-stabilized zirconia (Y-TZP) and allows post-sintered machining that does not require any subsequent treatment. The aim of this prospective study was to assess the clinical performance of veneered Ce-TZP/A frameworks for fixed dental prostheses. Fifteen patients with 22 Ce-TZP/A fixed prostheses were included in this study. The fixed dental prostheses were cemented with resin cement (baseline) and were evaluated at baseline and at 1, 6, 12, 24 and 36 months after cementation. Clinical events, including fracture and loss of retention, secondary caries, and marginal integrity, were recorded. The biologic outcome was judged by comparing the pre-treatment and post-treatment bleeding on probing (BOP), and probing pocket depth (PPD) of the abutment teeth. Radiographic examination was also performed at 12, 24 and 36 months. The mean observation period was 35.9±5.5 months. During this period, one abutment tooth was extracted due to root fracture and the survival rate was 95.2%. No significant change in BOP, PPD, and radiographic image was found during the 36-month follow-up period. Within the limitations of this study, Ce-TZP/A was found to provide sufficient stability as a framework material in all regions. Special attention, however, must be paid to designing framework that provides sufficient support for the veneer. Furthermore, studies with longer observation periods and more patients are needed. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  18. Neonate Auditory Brainstem Responses to CE-Chirp and CE-Chirp Octave Band Stimuli I: Versus Click and Tone Burst Stimuli. (United States)

    Cobb, Kensi M; Stuart, Andrew

    The purpose of the study was to generate normative auditory brainstem response (ABR) wave component peak latency and amplitude values for neonates with air- and bone-conducted CE-Chirps and air-conducted CE-Chirp octave band stimuli (i.e., 500, 1000, 2000, and 4000 Hz). A second objective was to compare neonate ABRs to CE-Chirp stimuli with ABR responses to traditional click and tone burst stimuli with the same stimulus parameters. Participants were 168 healthy neonates. ABRs were obtained to air- and bone-conducted CE-Chirp and click stimuli and air-conducted CE-Chirp octave band and tone burst stimuli. The effects of stimulus level, rate, and polarity were examined with air-conducted CE-Chirps and clicks. The effect of stimulus level was also examined with bone-conducted CE-Chirps and clicks and air-conducted CE-Chirp octave band stimuli. In general, ABR wave V amplitudes to air- and bone-conducted CE-Chirp stimuli were significantly larger (p < 0.05) than those evoked to traditional click and tone burst stimuli. Systematic statistically significant (p < 0.05) wave V latency differences existed between the air- and bone-conducted CE-Chirp and CE-Chirp octave band stimuli relative to traditional click and tone burst stimuli. ABRs to air- and bone-conducted CE-Chirps and CE-Chirp octave band stimuli may be valuable in the assessment of newborn infants. However, the prognostic value of such stimuli needs to be validated.

  19. Ce3+-ion-induced visible-light photocatalytic degradation and electrochemical activity of ZnO/CeO2 nanocomposite (United States)

    Rajendran, Saravanan; Khan, Mohammad Mansoob; Gracia, F.; Qin, Jiaqian; Gupta, Vinod Kumar; Arumainathan, Stephen


    In this study, pure ZnO, CeO2 and ZnO/CeO2 nanocomposites were synthesized using a thermal decomposition method and subsequently characterized using different standard techniques. High-resolution X-ray photoelectron spectroscopy measurements confirmed the oxidation states and presence of Zn2+, Ce4+, Ce3+ and different bonded oxygen species in the nanocomposites. The prepared pure ZnO and CeO2 as well as the ZnO/CeO2 nanocomposites with various proportions of ZnO and CeO2 were tested for photocatalytic degradation of methyl orange, methylene blue and phenol under visible-light irradiation. The optimized and highly efficient ZnO/CeO2 (90:10) nanocomposite exhibited enhanced photocatalytic degradation performance for the degradation of methyl orange, methylene blue, and phenol as well as industrial textile effluent compared to ZnO, CeO2 and the other investigated nanocomposites. Moreover, the recycling results demonstrate that the ZnO/CeO2 (90:10) nanocomposite exhibited good stability and long-term durability. Furthermore, the prepared ZnO/CeO2 nanocomposites were used for the electrochemical detection of uric acid and ascorbic acid. The ZnO/CeO2 (90:10) nanocomposite also demonstrated the best detection, sensitivity and performance among the investigated materials in this application. These findings suggest that the synthesized ZnO/CeO2 (90:10) nanocomposite could be effectively used in various applications. PMID:27528264

  20. Ce(3+)-ion-induced visible-light photocatalytic degradation and electrochemical activity of ZnO/CeO2 nanocomposite. (United States)

    Rajendran, Saravanan; Khan, Mohammad Mansoob; Gracia, F; Qin, Jiaqian; Gupta, Vinod Kumar; Arumainathan, Stephen


    In this study, pure ZnO, CeO2 and ZnO/CeO2 nanocomposites were synthesized using a thermal decomposition method and subsequently characterized using different standard techniques. High-resolution X-ray photoelectron spectroscopy measurements confirmed the oxidation states and presence of Zn(2+), Ce(4+), Ce(3+) and different bonded oxygen species in the nanocomposites. The prepared pure ZnO and CeO2 as well as the ZnO/CeO2 nanocomposites with various proportions of ZnO and CeO2 were tested for photocatalytic degradation of methyl orange, methylene blue and phenol under visible-light irradiation. The optimized and highly efficient ZnO/CeO2 (90:10) nanocomposite exhibited enhanced photocatalytic degradation performance for the degradation of methyl orange, methylene blue, and phenol as well as industrial textile effluent compared to ZnO, CeO2 and the other investigated nanocomposites. Moreover, the recycling results demonstrate that the ZnO/CeO2 (90:10) nanocomposite exhibited good stability and long-term durability. Furthermore, the prepared ZnO/CeO2 nanocomposites were used for the electrochemical detection of uric acid and ascorbic acid. The ZnO/CeO2 (90:10) nanocomposite also demonstrated the best detection, sensitivity and performance among the investigated materials in this application. These findings suggest that the synthesized ZnO/CeO2 (90:10) nanocomposite could be effectively used in various applications.

  1. Study of cationic substitutions mechanisms in the superconductor YBa{sub 2}Cu{sub 3}O{sub 6+x} and of its effects on structure and magnetic properties: case of zinc and of nickel; Etude des mecanismes de substitutions cationiques dans le supraconducteur YBa{sub 2}Cu{sub 3}O{sub 6+x} et de leurs effets sur la structure et les proprietes magnetiques: cas du zinc et du nickel

    Energy Technology Data Exchange (ETDEWEB)

    Villeneuve, R.


    Substitution of zinc nonmagnetic impurities in copper site of conductive planes in the compound YBa{sub 2}Cu{sub 3}O{sub 7} constitute a probe for studying the magnetism role in superconductivity apparition. This zinc substitution effects are put in evidence by neutrons and X-rays diffraction. Neel temperature of zinc substituted isolating compounds is lowered, this is attributed to zinc dilution effect of the bidimensional antiferromagnetic structure. Curie-Weiss type magnetic comportment in planes copper site, and the screening of the structural effects by the doping substitution indicate a reduction of the charges carriers. Nickel substitution induces along the c axis an important reduction of the lattice parameter, and a doubling of the magnetic lattice. This is attributed to nickel partial substitution in copper sites non affecting the charges transfer. (A.B.). 219 refs.

  2. An ionic liquid supported CeO2 nanoparticles–carbon nanotubes composite-enhanced electrochemical DNA-based sensor for the detection of Pb2+

    Directory of Open Access Journals (Sweden)

    Yan Li


    Full Text Available An electrochemical sensor incorporating a signal enhancement for the determination of lead (II ions (Pb2+ was designed on the basis of the thrombin-binding aptamer (TBA as a molecular recognition element and ionic liquid supported cerium oxide (CeO2 nanoparticles–carbon nanotubes composite modification. The composite comprises nanoparticles CeO2, multi-wall carbon nanotubes (MWNTs and hydrophobic room temperature ionic liquid (RTIL 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4. The electrochemical sensors were fabricated by immersing the CeO2–MWNTs–EMIMBF4 modified glassy carbon electrode (GCE into the solution of TBA probe. In the presence of Pb2+, the TBA probe could form stable G-quartet structure by the specific binding interactions between Pb2+ and TBA. The TBA-bound Pb2+ can be electrochemically reduced, which provides a readout signal for quantitative detection of Pb2+. The reduction peak current is linearly related to the concentration of Pb2+ from 1.0×10–8 M to 1.0×10–5 M with a detection limit of 5×10–9 M. This work demonstrates that the CeO2–MWNTs–EMIMBF4 nanocomposite modified GCE provides a promising platform for immobilizing the TBA probe and enhancing the sensitivity of the DNA-based sensors. Keywords: Electrochemical, DNA-based sensor, Lead (II ion, Ionic liquid, CeO2 nanoparticle, Multi-wall carbon nanotubes

  3. Preparation and characterization of cobalt-substituted anthrax lethal factor

    Energy Technology Data Exchange (ETDEWEB)

    Saebel, Crystal E.; Carbone, Ryan; Dabous, John R.; Lo, Suet Y. [Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Rd., Sudbury, Ontario, Canada P3E 2C6 (Canada); Siemann, Stefan, E-mail: [Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Rd., Sudbury, Ontario, Canada P3E 2C6 (Canada)


    Highlights: Black-Right-Pointing-Pointer Cobalt-substituted anthrax lethal factor (CoLF) is highly active. Black-Right-Pointing-Pointer CoLF can be prepared by bio-assimilation and direct exchange. Black-Right-Pointing-Pointer Lethal factor binds cobalt tightly. Black-Right-Pointing-Pointer The electronic spectrum of CoLF reveals penta-coordination. Black-Right-Pointing-Pointer Interaction of CoLF with thioglycolic acid follows a 2-step mechanism. -- Abstract: Anthrax lethal factor (LF) is a zinc-dependent endopeptidase involved in the cleavage of mitogen-activated protein kinase kinases near their N-termini. The current report concerns the preparation of cobalt-substituted LF (CoLF) and its characterization by electronic spectroscopy. Two strategies to produce CoLF were explored, including (i) a bio-assimilation approach involving the cultivation of LF-expressing Bacillus megaterium cells in the presence of CoCl{sub 2}, and (ii) direct exchange by treatment of zinc-LF with CoCl{sub 2}. Independent of the method employed, the protein was found to contain one Co{sup 2+} per LF molecule, and was shown to be twice as active as its native zinc counterpart. The electronic spectrum of CoLF suggests the Co{sup 2+} ion to be five-coordinate, an observation similar to that reported for other Co{sup 2+}-substituted gluzincins, but distinct from that documented for the crystal structure of native LF. Furthermore, spectroscopic studies following the exposure of CoLF to thioglycolic acid (TGA) revealed a sequential mechanism of metal removal from LF, which likely involves the formation of an enzyme: Co{sup 2+}:TGA ternary complex prior to demetallation of the active site. CoLF reported herein constitutes the first spectroscopic probe of LF's active site, which may be utilized in future studies to gain further insight into the enzyme's mechanism and inhibitor interactions.

  4. Vitreous Substitutes: The Present and the Future (United States)

    Caprani, Simona Maria; Airaghi, Giulia; Bartalena, Luigi; Testa, Francesco; Mariotti, Cesare; Porta, Giovanni; Simonelli, Francesca


    Vitreoretinal surgery has advanced in numerous directions during recent years. The removal of the vitreous body is one of the main characteristics of this surgical procedure. Several molecules have been tested in the past to fill the vitreous cavity and to mimic its functions. We here review the currently available vitreous substitutes, focusing on their molecular properties and functions, together with their adverse effects. Afterwards we describe the characteristics of the ideal vitreous substitute. The challenges facing every ophthalmology researcher are to reach a long-term intraocular permanence of vitreous substitute with total inertness of the molecule injected and the control of inflammatory reactions. We report new polymers with gelification characteristics and smart hydrogels representing the future of vitreoretinal surgery. Finally, we describe the current studies on vitreous regeneration and cell cultures to create new intraocular gels with optimal biocompatibility and rheological properties. PMID:24877085

  5. Biomaterials in search of a meniscus substitute. (United States)

    Rongen, Jan J; van Tienen, Tony G; van Bochove, Bas; Grijpma, Dirk W; Buma, Pieter


    The menisci fulfill key biomechanical functions in the tibiofemoral (knee) joint. Unfortunately meniscal injuries are quite common and most often treated by (partial) meniscectomy. However, some patients experience enduring symptoms, and, more importantly, it leads to an increased risk for symptomatic osteoarthritis. Over the past decades, researchers have put effort in developing a meniscal substitute able to prevent osteoarthritis and treat enduring clinical symptoms. Grossly, two categories of substitutes are observed: First, a resorbable scaffold mimicking biomechanical function which slowly degrades while tissue regeneration and organization is promoted. Second, a non resorbable, permanent implant which mimics the biomechanical function of the native meniscus. Numerous biomaterials with different (material) properties have been used in order to provide such a substitute. Nevertheless, a clinically applicable cartilage protecting material is not yet emerged. In the current review we provide an overview, and discuss, these different materials and extract recommendations regarding material properties for future developmental research. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. New transfusion strategies: red cell substitutes. (United States)

    Winslow, R M


    Red cell substitutes are solutions that can potentially be used in emergencies or during surgery when rapid expansion of the blood volume with an oxygen carrier is needed. The three main types of products in development are based on cell-free hemoglobin, perfluorocarbon emulsions, or liposome-encapsulated hemoglobin. None is currently approved for clinical use, but several are in advanced clinical trials. Outside the red blood cell, hemoglobin is subject to degradation and heme loss. It readily diffuses in the plasma space and effectively scavenges nitric oxide. These properties must be understood and controlled if hemoglobin-based products are to fulfill their promise. The development of red cell substitutes affords us a deeper insight into how oxygen is delivered to tissues in the microcirculation and how blood-flow distribution is regulated within and between organs. As red cell substitutes become available to clinicians and scientists, clinical applications are expected to expand.

  7. Myxomycetes da Chapada do Araripe (Crato - CE, Brasil Myxomycetes from Chapada do Araripe (Crato, CE, Brazil

    Directory of Open Access Journals (Sweden)

    Laise de Holanda Cavalcanti


    Full Text Available Foi efetuado um levantamento dos Myxomyeetes ocorrentes em área de floresta no município do Crato, CE (7º13'53" S; 39º24'28'' W; Alt. 422m, assinalando-se as seguintes famílias e gêneros: Ceratiomyxaceae (Ceratiomyxa, 1 sp.; Cribrariaceae (Cribraria, lsp., Dictydium, 1 sp.; Didymiaceae (Didymium, 2sp.; Enteridiaceae (Dicrydiaethalium, 1sp.; Physaraceae (Badhamia, 2sp., Fuligo, 2sp., Physarum, 5sp.; Steinonitaceae (Comatricha, 3sp., Sfemonitis, 6sp.; Trichiaceae (Arcyria, 3sp., Hemitrichia, 2sp., Periclwena, 1 sp.- Constatou-se preferência das espécies para frutificar em troncos mortos de dicotiledôneas, seguindo-se restos de palmeiras e folhedo. O levantamento eleva para 30 o número de espécies referidas para o Ceará. Uma família e 19 espécies são novos registros para o Estado e Arcyria magna var. rosea Rex é nova referência para o Brasil. São apresentados comentários, chave de identificação e distribuição geográfica das espécies no Nordeste do Brasil.A survey on Myxomycetes was made in the woods of Crato Municipality. State of Ceará, Brazil (7º13'53" S; 39º24,28" W; Alt. 422m. when the following families and genera were registered: Ceratiomyxaceae (Ceratiomyxa, 1 sp.; Cribrariaceae (Cribraria, 1 sp., Dictydium. 1 sp.; Didymiaceae (Didymium, 2sp.; Enteridiaceae Dictydiaethalium, 1 sp.; Physaraceae (Badhamia. 2sp., Fuligo, 2sp., Physarum, 5sp.; Stemonitaceae Comatricha, 3sp., Stemonitis, 6sp.; Trichiaceae (Arcyria, 3sp., Hemitrichia, 2sp., Perichaena, lsp..The species sporulated mostly on dead dicotyledones wood, followed by monocotyledones (Arecaceae debris and litter. The survey raises the number of registers referred to the State of Ceará to 30 species. One family and 19 species are new records for that State while Arcyria magna var. rosea Rex represents a new record for Brazil. Key for the species, comments and geographical distribution in Northeast Brazil arc presented.

  8. Effect of CeO2 Infiltration on Hybrid Direct Carbon Fuel Cell Performance

    DEFF Research Database (Denmark)

    Ippolito, Davide; Deleebeeck, Lisa; Kammer Hansen, Kent


    The effect of CeO2 infiltration into the anode or CeO2 mixed with the carbon-fuel on the performance of a Hybrid Direct Carbon Fuel Cell (HDCFC) was studied through the use of polarization curves and electrochemical impedance spectroscopy. The use CeO2 in both ways helped to increase the cell...... performance. In particular, mixing CeO2 with carbon represents the best strategy to increase the cell power output....

  9. A New Substitution Cipher - Random-X

    Directory of Open Access Journals (Sweden)

    Falguni Patel


    Full Text Available Ciphers are the encryption methods to prepare the algorithm for encryption and decryption. The currently known ciphers are not strong enough to protect the data. A new substitution cipher Random-X that we introduce in this paper can be used for password encryption and data encryption. Random-X cipher is a unique substitution cipher which replaces the units of plaintext with triplets of letters. The beauty of this cipher is that the encrypted string of the same plain text is not always same. This makes it strong and difficult to crack. This paper covers the principle the implementation ideas and testing of Random-X cipher.

  10. Intramolecular homolytic substitution of sulfinates and sulfinamides. (United States)

    Coulomb, Julien; Certal, Victor; Larraufie, Marie-Hélène; Ollivier, Cyril; Corbet, Jean-Pierre; Mignani, Gérard; Fensterbank, Louis; Lacôte, Emmanuel; Malacria, Max


    A general and efficient method for the synthesis of cyclic sulfinates and sulfinamides based on intramolecular homolytic substitution (S(H)i) at the sulfur atom by aryl or alkyl radicals is described. Both alkyl and benzofused compounds can be accessed directly from easily prepared acyclic precursors. Enantiomerically enriched sulfur-based heterocycles were formed through an S(H)i process with inversion of configuration at the sulfur atom. Cyclization of prochiral radicals proceeded with varying stereochemical outcomes, depending on the size of the incoming radical. 2-Pyridyl and 2-quinolyl radicals led to biaryl compounds, which result from attack onto the ortho position of the arylsulfinate rather than a thiophilic substitution.

  11. Non-fused Phospholes as Fluorescent Probes for Imaging of Lipid Droplets in Living Cells

    Directory of Open Access Journals (Sweden)

    K. Peter R. Nilsson


    Full Text Available Molecular tools for fluorescent imaging of specific compartments in cells are essential for understanding the function and activity of cells. Here, we report the synthesis of a series of pyridyl- and thienyl-substituted phospholes and the evaluation of these dyes for fluorescent imaging of cells. The thienyl-substituted phospholes proved to be successful for staining of cultured normal and malignant cells due to their fluorescent properties and low toxicity. Co-staining experiments demonstrated that these probes target lipid droplets, which are, lipid-storage organelles found in the cytosol of nearly all cell types. Our findings confirm that thienyl-substituted phospholes can be utilized as fluorescent tools for vital staining of cells, and we foresee that these fluorescent dyes might be used in studies to unravel the roles that lipid droplets play in cellular physiology and in diseases.

  12. Luminescence and luminescence quenching in Gd3(Ga,Al)5O12 scintillators doped with Ce3+. (United States)

    Ogiegło, Joanna M; Katelnikovas, Arturas; Zych, Aleksander; Jüstel, Thomas; Meijerink, Andries; Ronda, Cees R


    The optical properties of gadolinium gallium aluminum garnet, Gd3(Ga,Al)5O12, doped with Ce(3+) are investigated as a function of the Ga/Al ratio, aimed at an improved understanding of the energy flow and luminescence quenching in these materials. A decrease of both the crystal field strength and band gap with increasing content of Ga(3+) is observed and explained by the geometrical influence of Ga(3+) on the crystal field splitting of the 5d level in line with theoretical work of Muñoz-García et al. ( uñoz-García, A. B.; Seijo, L. Phys. Rev. B 2010, 82, 184118 ). Thermal quenching results in shorter decay times as well as reduced emission intensities for all samples in the temperature range from 100 to 500 K. An activation energy for emission quenching is calculated from the data. The band gap of the host is measured upon Ga substitution and the decrease in band gap is related to Ga(3+) substitution into tetrahedral sites after all octahedral sites are occupied in the garnet material. Based on the change in band gap and crystal field splitting, band diagrams can be constructed explaining the low thermal quenching temperatures in the samples with high Ga content. The highest luminescence intensity is found for Gd3(Ga,Al)5O12 with 40% of Al(3+) replaced by Ga(3+).

  13. Energy transfer from Ce3+ to Eu3+ through Tb3+ chain in YPO4:Ce3+/Tb3+/Eu3+ phosphors (United States)

    Yang, Yuguo; Lv, Xianshun; Wei, Lei; Xu, Jianhua; Yu, Huajian; Hu, Yanyan; Zhang, Huadi; Liu, Bing; Wang, Xuping; Li, Qinggang


    We synthesized a series of YPO4:Ce3+/Tb3+/Eu3+ phosphors by a solid state reaction. All of phosphors have a single phase, showing that the doping ions could not change the phase of YPO4 host. The emission intensities of Ce3+, Tb3+ and Eu3+ ions clearly depend on the Tb3+ concentrations in YPO4:Ce3+/Tb3+/Eu3+ phosphors. The emission intensity of Ce3+ emission decreases gradually but the emission intensity of Eu3+ emission increases continuously with the increasing Tb3+ concentration because of the energy transfer from Ce3+ to Eu3+ through Tb3+. On the basis of the luminescent properties of YPO4:Ce3+/Tb3+/Eu3+ phosphors, the possible energy transfer mechanism was speculated.

  14. Photocatalytic degradation of methyl orange by CeO2 and Fe-doped CeO2 films under visible light irradiation. (United States)

    Channei, D; Inceesungvorn, B; Wetchakun, N; Ukritnukun, S; Nattestad, A; Chen, J; Phanichphant, S


    Undoped CeO2 and 0.50-5.00 mol% Fe-doped CeO2 nanoparticles were prepared by a homogeneous precipitation combined with homogeneous/impreganation method, and applied as photocatalyst films prepared by a doctor blade technique. The superior photocatalytic performances of the Fe-doped CeO2 films, compared with undoped CeO2 films, was ascribed mainly to a decrease in band gap energy and an increase in specific surface area of the material. The presence of Fe(3+) as found from XPS analysis, may act as electron acceptor and/or hole donor, facilitating longer lived charge carrier separation in Fe-doped CeO2 films as confirmed by photoluminescence spectroscopy. The 1.50 mol% Fe-doped CeO2 film was found to be the optimal iron doping concentration for MO degradation in this study.

  15. Electronic structure of CeO studied by a four-component relativistic configuration interaction method (United States)

    Moriyama, Hiroko; Tatewaki, Hiroshi; Yamamoto, Shigeyoshi


    We studied the ground and excited states of CeO using the restricted active space CI method in the energy range below 25 000 cm-1. Energy levels are computed to within errors of 2700 cm-1. Electron correlation effects arising from the ionic core composed of Ce 5s, 5p, 4f*, 5d*, and O 2s, 2p spinors play crucial role to CeO spectra, as well as correlation effects of electrons distributed in the valence Ce 4f, 5d, 6s, and 6p spinors. Here, 4f* and 5d* denote spinors expanded to describe electron polarization between Ce and O. A bonding mechanism is proposed for CeO. As the two separate atoms in their ground states, Ce (4f 15d16s2) 1G4 and O (2s22p4) 3P2, approach each other, a CeO2+ core is formed by two-electron transfer from Ce 5d, 6s to O 2p. Inside this ellipsoidal ion, a valence bond between Ce 5p and O 2s and an ionic bond between O 2p and Ce 5p are formed with back-donation through Ce 4f* and 5d*.

  16. Redox enzyme-mimicking activities of CeO2nanostructures: Intrinsic influence of exposed facets. (United States)

    Yang, Yushi; Mao, Zhou; Huang, Wenjie; Liu, Lihua; Li, Junli; Li, Jialiang; Wu, Qingzhi


    CeO 2 nanoparticles (NPs) have been well demonstrated as an antioxidant in protecting against oxidative stress-induced cellular damages and a potential therapeutic agent for various diseases thanks to their redox enzyme-mimicking activities. The Ce 3+ /Ce 4+ ratio and oxygen vacancies on the surface have been considered as the major originations responsible for the redox enzyme-mimicking activities of CeO 2 NPs. Herein, CeO 2 nanostructures (nanocubes and nanorods) exposed different facets were synthesized via a facile hydrothermal method. The characterizations by X-ray photoelectron spectroscopy, Raman spectroscopy, and UV-Vis spectroscopy show that the Ce 3+ /Ce 4+ ratio and oxygen vacancy content on the surfaces of as-synthesized CeO 2 nanostructures are nearly at the same levels. Meanwhile, the enzymatic activity measurements indicate that the redox enzyme-mimicking activities of as-synthesized CeO 2 nanostructures are greatly dependent on their exposed facets. CeO 2 nanocubes with exposed {100} facets exhibit a higher peroxidase but lower superoxide dismutase activity than those of the CeO 2 nanorods with exposed {110} facets. Our results provide new insights into the redox enzyme-mimicking activities of CeO 2 nanostructures, as well as the design and synthesis of inorganic nanomaterials-based artificial enzymes.

  17. In-situ electrochemical route to aerogel electrode materials of graphene and hexagonal CeO₂. (United States)

    Chen, Kunfeng; Xue, Dongfeng


    We reported a one-step in-situ electrochemical route to synthesize 3D aerogel electrode materials including graphene and hexagonal CeO2 composites. The graphene/CeO2 aerogel can be formed via freeze-drying graphene/CeO2 colloidal solution that was obtained by electrochemical exfoliation of graphite anode and in-situ deposition of CeO2 nanoparticles on graphene sheets in mixing electrolyte of (NH4)2SO4/Ce(NO3)3 and (NH4)2SO4/(NH4)2Ce(NO3)6. The as-obtained CeO2 nanoparticles were closely contacted with graphene, which can enhance the synergistic effect between graphene and CeO2. It is interesting that the as-obtained CeO2 products possessed hexagonal crystal structure that was rarely reported. The Faradaic reactivity of the graphene/CeO2 composites as supercapacitor was enhanced with the increase of the concentration of Ce salts in initial electrolyte. The introduction of CeO2 to graphene electrode can lead to the presence of additional pseudocapacitance besides the electric double-layer capacitance. This simple one-step in-situ electrochemical route can be extended to synthesize various graphene/metal oxide aerogel electrode materials for electric energy storage. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. On-line SPE-CE for the determination of insulin derivatives in biological fluids

    NARCIS (Netherlands)

    Visser, N.F.C.; van Harmelen, M.; Lingeman, H.; Irth, H.


    An on-line SPE-CE system is described for the determination of insulin derivatives in urine, serum and plasma. By combining techniques based on different separation mechanisms, in this case reversed-phase SPE and CE, a more selective sample clean-up is obtained. The described on-line SPE-CE

  19. Comment on “Synthesis of ceria (CeO{sub 2} and CeO{sub 2−x}) nanoparticles via decarbonation and Ce(III) oxidation of synthetic bastnaesite (CeCO{sub 3}F)” by Montes-Hernandez et al

    Energy Technology Data Exchange (ETDEWEB)

    Gysi, Alexander P., E-mail: [Department of Geology and Geological Engineering, Colorado School of Mines, 1516 Illinois Street, Golden, CO, 80401 (United States); Williams-Jones, Anthony E. [Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montreal, QC, Canada, H3A 2A7 (Canada)


    Montes-Hernandez et al. [5] recently reported results of a study of the decarbonation of fine-grained synthetic bastnäsite-(Ce) precipitates involving the oxidation of Ce(III) to Ce(IV) and the formation of ceria (CeO{sub 2} and CeO{sub 2-x} with oxygen vacancies) nano-particles. The purpose of their study was to show that oxidation of Ce(III) to Ce(IV) occurs spontaneously during heating of bastnäsite-(Ce) in air, a vacuum, N{sub 2} or Ar gas. However, their interpretation of the formation of CeO{sub 2} is not supported by the findings of Gysi and Williams-Jones [3], who showed that natural bastnäsite-(Ce) decomposes to form rare earth element (REE) oxyfluorides (REEOF). The latter was documented using differential scanning calorimetric (DSC) and thermogravimetric (TGA) experiments under a deoxygenated N{sub 2} atmosphere. In their experiments, Gysi and Williams-Jones [3] found no evidence for the oxidation of Ce(III) to Ce(IV). This raises the question of whether the experiments of Montes-Hernandez et al. [5] in a N{sub 2} atmosphere (and by extension in an Ar atmosphere) were compromised because of contamination by O{sub 2} and that, as a result, they reached the erroneous conclusion that Ce(III) oxidizes spontaneously to Ce(IV) during heating of bastnäsite-(Ce) under these conditions. In order to explain the disagreement between their findings and those of Gysi and Williams-Jones [3], Montes-Hernandez et al. [5], proposed that the X-ray diffraction data of the former study were incorrectly interpreted. Here, we provide further evidence that the natural bastnäsite-(Ce) employed in the study by Gysi and Williams-Jones [3] decomposed to form REE oxyfluorides (i.e., CeOF, LaOF, PrOF and NdOF) and not CeO{sub 2}, and supply explanations for why Montes-Hernandez et al. [5] erroneously concluded that CeO{sub 2} is produced during decomposition of this mineral under N{sub 2} and Ar atmospheres. In so doing, we hope to provide new insights into the decomposition of

  20. Properties of transparent (Gd,Lu)3(Al,Ga)5O12:Ce ceramic with Mg, Ca and Ce co-dopants (United States)

    Wang, Yimin; Baldoni, Gary; Brecher, Charles; Rhodes, William H.; Shirwadkar, Urmila; Glodo, Jarek; Shah, Ishaan; Ji, Chuncheng


    Cerium activated mixed lutetium/gadolinium- and aluminum/gallium-based garnets have great potential as host scintillators for medical imaging applications. (Gd,Lu)3(Al,Ga)5O12:Ce and denoted as GLuGAG feature high effective atomic number and good light yield, which make it particularly attractive for Positron Emission Tomography (PET) and other γ-ray detection applications. For PET application, rapid decay and good timing resolution are extremely important. Most Ce-doped mixed garnet materials such as GLuGAG:Ce, have their main decay component at around 80 ns. However, it has been reported that the decays of some single crystal scintillators (e.g., LSO and GGAG) can be effectively accelerated by codoping with selected additives such as Ca, Mg and B. In this study, transparent polycrystalline (Gd,Lu)3(Al,Ga)5O12:Ce ceramics codoped with Ca or Mg or additional Ce, were fabricated by the sinter-HIP approach. It was found the transmission of the ceramics are closely related to the microstructure of the ceramics. As the co-dopant levels increase, 2nd phase occurs in the ceramic and thus transparency of the ceramic decreases. Ca and Mg co-doping in GLuGAG:Ce ceramic effectively accelerate decays of GLuGAG:Ce ceramics at a cost of light output. However, additional Ce doping in the GLuGAG:Ce has no benefit on improving decay time but, on the other hand, reduces transmission, light output. The mechanism under the different scintillation behaviors with Mg, Ca and Ce dopants are discussed. The results suggest that decay time of GLuGAG:Ce ceramics can be effectively tailored by co-doping GLuGAG:Ce ceramic with Mg and Ca for applications with optimal timing resolution.

  1. Comparison between the Oxygen Reduction Reaction Activity of Pd5Ce and Pt5Ce

    DEFF Research Database (Denmark)

    Tripkovic, Vladimir; Zheng, Jian; Rizzi, Gian Andrea


    if results on a several-fold activity increase of a series of Pt/rare-earth alloys hold also for Pd rare-earth alloys. Pd5Ce crystallizes in two phases, a so-called low-temperature phase, L-Pd5Ce, which has a cubic symmetry, and a high-temperature phase, H-Pd5Ce, with a hexagonal symmetry. In both cases...

  2. Substituting freshwater: Can ocean desalination and water recycling capacities substitute for groundwater depletion in California? (United States)

    Badiuzzaman, Pierre; McLaughlin, Eoin; McCauley, Darren


    While the sustainability of resource depletion is a longstanding environmental concern, wider attention has recently been given to growing water scarcity and groundwater depletion. This study seeks to test the substitutability assumption embedded in weak sustainability indicators using a case study of Californian water supply. The volume of groundwater depletion is used as a proxy for unsustainable water consumption, and defined by synthesising existing research estimates into low, medium and high depletion baselines. These are compared against projected water supply increases from ocean desalination and water recycling by 2035, to determine whether new, drought-proof water sources can substitute for currently unsustainable groundwater consumption. Results show that the maximum projected supply of new water, 2.47 million acre-feet per year (MAF/yr), is sufficient to meet low depletion estimates of 2.02 MAF/yr, but fails to come near the high depletion estimate of 3.44 MAF/yr. This does not necessarily indicate physical limitations of substitutability, but more so socio-economic limitations influenced by high comparative costs. By including capacities in demand-substitutability via urban water conservation, maximum predicted capacities reach 5.57 MAF/yr, indicating wide room for substitution. Based on these results, investment in social and institutional capital is an important factor to enhance demand-side substitutability of water and other natural resources, which has been somewhat neglected by the literature on the substitutability of natural resources. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Gamma-ray spectroscopy of the nucleus {sup 139}Ce

    Energy Technology Data Exchange (ETDEWEB)

    Bucurescu, D.; Cata-Danil, G.; Cata-Danil, I.; Ivascu, M.; Marginean, N.; Marginean, R.; Mihailescu, L.C.; Rusu, C.; Suliman, G. [Horia Hulubei National Institute of Physics and Nuclear Engineering, P.O. Box MG-6, Bucharest (Romania)


    Gamma-ray coincidence techniques are used to determine new level structures in the N=81 nucleus {sup 139}Ce, at low spins and excitation energies with the {sup 139}La(p,n{gamma}) reaction at 5.0 and 6.0 MeV incident energy, and at high spins with the {sup 130}Te({sup 12}C,3n{gamma}) reaction at 50.5 MeV, respectively. Lifetime determinations are also made in the (p,n{gamma}) reaction with the centroid DSA method. The observed level structures are discussed by comparison with existing calculations and with those in the neighbouring nucleus {sup 140}Ce. (orig.)

  4. The high-pressure phase of CePtAl

    Energy Technology Data Exchange (ETDEWEB)

    Heymann, Gunter [Univ. Innsbruck (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie; Heying, Birgit; Rodewald, Ute C. [Univ. Muenster (Germany). Inst. fuer Anorganische und Analytische Chemie; Janka, Oliver [Univ. Muenster (Germany). Inst. fuer Anorganische und Analytische Chemie; Univ. Oldenburg (Germany). Inst. fuer Chemie


    The intermetallic aluminum compound HP-CePtAl was synthesized by arc melting of the elements with subsequent high-pressure/high-temperature treatment at 1620 K and 10.5 GPa in a multianvil press. The compound crystallizes in the hexagonal MgZn{sub 2}-type structure (P6{sub 3}/mmc) with lattice parameters of a=552.7(1) and c=898.8(2) pm refined from powder X-ray diffraction data. With the help of single crystal investigations (wR=0.0527, 187 F{sup 2} values, 13 variables), the proposed structure type was confirmed and the mixed Pt/Al site occupations could be refined. Magnetic susceptibility measurements showed a disappearance of the complex magnetic ordering phenomena, which are observed in NP-CePtAl.

  5. Identification and Quality Assessment of Chrysanthemum Buds by CE Fingerprinting

    Directory of Open Access Journals (Sweden)

    Xiaoping Xing


    Full Text Available A simple and efficient fingerprinting method for chrysanthemum buds was developed with the aim of establishing a quality control protocol based on biochemical makeup. Chrysanthemum bud samples were successively extracted by water and alcohol. The fingerprints of the chrysanthemum buds samples were obtained using capillary electrophoresis and electrochemical detection (CE-ED employing copper and carbon working electrodes to capture all of the chemical information. 10 batches of chrysanthemum buds were collected from different regions and various factories to establish the baseline fingerprint. The experimental data of 10 batches electropherogram buds by CE were analyzed by correlation coefficient and the included angle cosine methods. A standard chrysanthemum bud fingerprint including 24 common peaks was established, 12 from each electrode, which was successfully applied to identify and distinguish between chrysanthemum buds from 2 other chrysanthemum species. These results demonstrate that fingerprint analysis can be used as an important criterion for chrysanthemum buds quality control.

  6. Ni-CeO2 Cermets Synthesis by Solid State Sintering of Ni/CeO2 Multilayer

    Directory of Open Access Journals (Sweden)

    Aleksandras ILJINAS


    Full Text Available Nickel and gadolinium doped cerium oxide (GDC cermet is intensively investigated for an application as an anode material for solid oxide fuel cells based on various electrolytes. The purpose of the present investigation is to analyze morphology, microstructure, and optical properties of deposited and annealed for one hour in the temperatures from 500 ºC to 900 ºC Ni/CeO2 multilayer thin films deposited by sputtering. The crystallographic structure of thin films was investigated by X-ray diffraction. The morphology of the film cross-section was investigated with scanning electron microscope. The elemental analysis of samples was investigated by energy-dispersive X-ray spectroscopy. The fitting of the optical reflectance data was made using Abeles matrix method that is used for the design of interference coatings. The film cross-section of the post-annealed samples consisted of four layers. The first CeO2 layer (on Si had the same fine columnar structure with no features of Ni intermixing. The part of Ni (middle-layer after annealing was converted to NiO with grain size exceeding 100 nm. The CeO2 layer deposited on Ni was divided into two layers. Lower layer had small grains not exceeding 25 nm and consisting of NiO and CeO2 mixture. Upper layer consisted of CeO2 columns with approximate thickness of 50 nm. Ni sample annealed at 600 ºC was fully oxidized. The NiO thickness and refraction index were almost steady after annealing in various temperatures. The approximation of experimental reflectance data was successful only for the samples with one transparent homogeneous layer. The reflectance of the Ni/CeO2 samples annealed at intermediate temperatures could not be fitted using one-layer or three-layer model. That may show that a simplified model could not be implemented.  The real system has complicated distribution of refraction index. DOI:

  7. Nouvelle espèce des Syntomides (Lepidoptera Heterocera)

    NARCIS (Netherlands)

    Snellen, P.C.T.


    Quatre mâles frais et bien conservés de 58—64 millim. d’envergure. Cette nouvelle espèce, gigantesque pour une Syntomide, appartient au genre Automolis, tel qu’il a été défini par Herrich-Schäffer, dans son ouvrage »Sammlung aussereuropäischer Schmetterlinge” (p. 21); le nom est emprunté au bien

  8. Qu'est-ce que l'Univers ?

    CERN Document Server


    Les plus grans spécialistes français sont réunis dans ce quatrième volume. Ils éclairent les grandes questions que pose la cosmologie, le Système solaire, les étoiles et les galaxies, la Terre, les océans et le climat, la matière et son organisation, l'évolution des mathématiques, la complexité, les transformations chimiques.

  9. Proposal for product development model focused on ce certification methodology

    Directory of Open Access Journals (Sweden)

    Nathalia Marcia Goulart Pinheiro


    Full Text Available This paper presents a critical analysis comparing 21 product development models in order to identify whether these structures meet the demands Product Certification of the European Community (CE. Furthermore, it presents a product development model, comprising the steps in the models analyzed, including improvements in activities for referred product certification. The proposed improvements are justified by the growing quest for the internationalization of products and processes within companies.

  10. Synthesis and photoluminescence characterization of Ce and Dy ...

    Indian Academy of Sciences (India)

    A = Na or Li), La2O3, Dy2O3/Ce2O3 and WO3 with high purity of 99·9% were used. They were taken in stoichiome- tric amounts. The Dy3+ concentrations were varied from 0·1 to 1 mol%. The starting materials were mixed thoroughly for 1 h using the agate mortar pestle. The crushed samples were placed in a silica crucible ...

  11. Determination of the Earth's Plasmapause Location from the CE-3 EUVC Images (United States)

    He, Fei; Zhang, Xiao-Xin; Chen, Bo; Fok, Mei-Ching; Nakano, Shinya


    The Moon-based Extreme Ultraviolet Camera (EUVC) aboard China's Chang'e-3 (CE-3) mission has successfully imaged the entire Earth's plasmasphere for the first time from the side views on lunar surface. An EUVC image on 21 April 2014 is used in this study to demonstrate the characteristics and configurations of the Moon-based EUV imaging and to illustrate the determination algorithm of the plasmapause locations on the magnetic equator. The plasmapause locations determined from all the available EUVC images with the Minimum L Algorithm are quantitatively compared with those extracted from insitu observations (Defense Meteorological Satellite Program, Time History of Events and Macroscale Interactions during Substorms, and Radiation Belt Storm Probes). Excellent agreement between the determined plasmapauses seen by EUVC and the extracted ones from other satellites indicates the reliability of the Moon-based EUVC images as well as the determination algorithm. This preliminary study provides an important basis for future investigation of the dynamics of the plasmasphere with the Moon-based EUVC imaging.

  12. Physical, biochemical and genetic characterization of enterocin CE5-1 produced by Enterococcus faecium CE5-1 isolated from Thai indigenous chicken intestinal tract

    Directory of Open Access Journals (Sweden)

    Kraiyot Saelim


    Full Text Available Enterocin CE5-1 produced by Enterococcus faecium CE5-1 isolated from the chicken gastrointestinal tract was active in the wide range of pH 2-10 and temperature 30-100°C and sensitive to proteolytic enzymes and -amylase. It remained active after storage at -20°C for 2 months. Moreover, enterocin CE5-1 showed antibacterial activity against lactobacilli, bacilli, listeria, staphylococci and enterococci, especially antibiotic-resistant enterococci. In vitro study of enterocin CE5-1 decreased the population of Ent. faecalis VanB from 6.03 to 4.03 log CFU/ml. The lethal mode of action of enterocin CE5-1 appeared to be pore and filament formation in the cell wall. PCR sequencing analysis revealed the presence of two open reading frames (ORFs, containing enterocin CE5-1 (entCE5-1 and enterocin immunity (entI gene. Therefore, enterocin CE5-1 from Ent. faecium CE5-1 could possibly be used as an antimicrobial agent to control foodborne pathogen, spoilage bacteria and antibiotic-resistant enterococci in foods, feeds and the environments.

  13. Photocatalytic Degradation of Methyl Orange by CeO2 and Fe–doped CeO2 Films under Visible Light Irradiation


    D. Channei; B. Inceesungvorn; N. Wetchakun; S. Ukritnukun; A. Nattestad; J. Chen; S. Phanichphant


    Undoped CeO2 and 0.50?5.00?mol% Fe-doped CeO2 nanoparticles were prepared by a homogeneous precipitation combined with homogeneous/impreganation method, and applied as photocatalyst films prepared by a doctor blade technique. The superior photocatalytic performances of the Fe-doped CeO2 films, compared with undoped CeO2 films, was ascribed mainly to a decrease in band gap energy and an increase in specific surface area of the material. The presence of Fe3+ as found from XPS analysis, may act ...

  14. Radon gamma-ray spectrometry with YAP:Ce scintillator

    CERN Document Server

    Plastino, W; De Notaristefani, F


    The detection properties of a YAP:Ce scintillator (YAlO sub 3 :Ce crystal) optically coupled to a Hamamatsu H5784 photomultiplier with standard bialkali photocathode have been analyzed. In particular, the application to radon and radon-daughters gamma-ray spectrometry was investigated. The crystal response has been studied under severe extreme conditions to simulate environments of geophysical interest, particularly those found in geothermal and volcanic areas. Tests in water up to a temperature of 100 deg.C and in acids solutions such as HCl (37%), H sub 2 SO sub 4 (48%) and HNO sub 3 (65%) have been performed. The measurements with standard radon sources provided by the National Institute for Metrology of Ionizing Radiations (ENEA) have emphasized the non-hygroscopic properties of the scintillator and a small dependence of the light yield on temperature and HNO sub 3. The data collected in this first step of our research have pointed out that the YAP:Ce scintillator can allow high response stability for rad...

  15. Qu'est-ce que la linguistique fonctionnelle?

    Directory of Open Access Journals (Sweden)

    André Martinet


    Full Text Available

    Dans cet article, André Martinet précise la valeur que le mot "fonction" a pour les membres de la Société Internationale de Linguistique Fonctionnelle, insistant sur le sens fondamental de "rôle que joue la langue dans la communication de l'expérience humaine"; explique l'appartenance de la linguistique aux sciences des cultures, ce que permet dépasser le recours à l'introspection et déterminer, comme pertinence de cette science, celle de la communication; fournit sa définition d'une langue (pas de la langue comme "instrument de communication doublement articulé", tout en considérant que cette notion doit fonctionner comme une stipulation afin de pouvoir identifier ce qu'est une langue et ce qui la distingue des autres langues; alerte sur la tentation d'inclure dans cette définition des éléments non nécessairement constitutifs. Cette vision fonctionnaliste, en n'excluant aucun des conditionnements de l'opération langagière, mène les fonctionnalistes à ne pas invoquer des nouvelles disciplines telles que l'énontiation, la pragmatique et même la sociolinguistique.

  16. Pornography is No Substitute for Sex. (United States)

    Parker, Shane


    Presents one educator's opinions on the use of computers in foreign-language instruction, as well as in other areas of life in general. He suggests that computers, and particularly CD-ROMs, can be very useful in helping to instruct students, but they are no substitute for one-on-one interactions between students and teachers and should be kept in…

  17. Synthesis of enantiopure 3-substituted morpholines

    DEFF Research Database (Denmark)

    Bornholdt, Jan; Felding, Jakob; Kristensen, Jesper Langgaard


    Enantiopure 3-substituted morpholines were assembled through ring-opening of a N-2-benzothiazolesulfonyl (Bts) activated aziridine with organocuprates followed by a ring annulation reaction with a vinylsulfonium salt under microwave conditions. Deprotection of the N-Bts group proceeds under very...

  18. Facile Synthesis of N -Substituted Benzimidazoles

    NARCIS (Netherlands)

    Kurhade, Santosh; Rossetti, Arianna; Dömling, Alexander


    A particularly mild and efficient one-pot synthesis of N-substituted benzimidazole derivatives was developed. 2-Fluoro-5-nitrophenylisocyanide reacts with a diverse set of primary amines to afford the respective products in moderate to very good yield (35-95%; 20 examples).

  19. Synthesis and electrochemical studies of phenylazo substituted ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 112; Issue 6. Synthesis and electrochemical studies of phenylazo substituted tetraaza macrocyclic complexes of Ni(II). Randhir Singh Suresh Kumar Amarendra Bhattacharya. Inorganic and Analytical Volume 112 Issue 6 December 2000 pp 601-605 ...

  20. Electromagnetic properties of nanocrystalline Al substituted ...

    Indian Academy of Sciences (India)

    substituted MgCuMn ferrites make them find applications in microwave devices, such as circulators and isolators etc. The applicability of ... sis [3], gas sensors [4], drug delivery [5] and hyperthermia. [6]. The general formula for spinel .... dependence, thus obeying the Vegard's law [15], as given in table 1. The above variation ...

  1. Transparency, Prices and Welfare with Imperfect Substitutes

    NARCIS (Netherlands)

    Boone, J.; Potters, J.J.M.


    Markets that are not completely transparent feature complex comparative statics with respect to the effect of number of firms, elasticity of substitution between goods and degree of transparency on equilibrium prices.The main result is that the following 'common wisdom' is incorrect: more

  2. Electrical characterization of zirconium substituted barium titanate ...

    Indian Academy of Sciences (India)

    multilayer capacitors, thermistors and other devices owing to their high dielectric constant. The substitution of ... ionic or mixed electronic–ionic materials and even insula- tors (Macdonald 1987). The resultant ..... Buchanan R C 1991 Principles of electronic ceramics (New York: Marcel Dekker) p. 250. Clarke R and Burfoot ...

  3. Biological activities of substituted trichostatic acid derivatives

    Indian Academy of Sciences (India)


    Abstract. New substituted trichostatic acid derivatives have been synthesized and evaluated for their biological activities towards the H661 non-small lung cancer cell line. These syntheses were achieved by alkylation of propiophenones to introduce the side chain with a terminal precursor of hydroxamic acid.

  4. Biological activities of substituted trichostatic acid derivatives

    Indian Academy of Sciences (India)

    New substituted trichostatic acid derivatives have been synthesized and evaluated for their biological activities towards the H661 non-small lung cancer cell line. These syntheses were achieved by alkylation of propiophenones to introduce the side chain with a terminal precursor of hydroxamic acid and aminobenzamide ...

  5. Preclinical evaluation of injectable bone substitute materials

    NARCIS (Netherlands)

    Bongio, M.; Beucken, J.J.J.P van den; Leeuwenburgh, S.C.G.; Jansen, J.A.


    Injectable bone substitutes (IBSs) represent an attractive class of ready-to-use biomaterials, both ceramic- and polymer-based, as they offer the potential benefit of minimally invasive surgery and optimal defect filling. Although in vitro assessments are the first step in the process of

  6. Electrochemical oxidation of substituted benzylamines in aquo ...

    Indian Academy of Sciences (India)

    Electrochemical oxidation of nine para- and meta-substituted benzylamines in varying mole fractions of acetic acid in water has been investigated in the presence of 0.1 M sulphuric acid as supporting electrolyte. The oxidation potentials correlate well with Hammett's substituent constants affording negative reaction ...

  7. Synthesis and biological activities of substituted N ...

    African Journals Online (AJOL)



    Dec 7, 2011 ... The present study describes the synthesis, antioxidant and antibacterial activities of substituted N'- benzoylhydrazone ... these derivatives possess promising antioxidant and antibacterial activities, which can be explored for generating new ...... triazole and their divalent nickel complexes. Synth. React. Inorg ...

  8. Photodimerization in pyrimidine-substituted dipeptides

    DEFF Research Database (Denmark)

    Lohse, Brian; Ramanujam, P.S.; Hvilsted, Søren


    was compared in aqueous solution: it was dependent on the substitution of the pyrimidine ring. N-alpha,N-alpha'-bis-(uracil-1-ylacetyl)-(N-epsilon-glycylomithineamide) and N-alpha,N-alpha'-bis-(5-bromouracil-1-ylacetyl)-(N-epsilon-glycylomithineamide) were identified as possible candidates for optical data...

  9. Five Strategies to Enhance Your Substitute Teaching (United States)

    Gresham, Jeanie; Donihoo, John; Cox, Tanisha


    Skillful substitute teachers are critical to student achievement, especially in today's high-stakes accountability environment. Because teachers are absent from duty, some for short periods of time and others for lengthy time frames, schools may find it difficult to meet high academic and accountability standards without prepared substitute…

  10. 40 CFR 721.1805 - Substituted bisaniline. (United States)


    ... Section 721.1805 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES... reporting. (1) The chemical substance identified generically as a substituted bisaniline (PMN P-96-1410) is... part apply to this section except as modified by this paragraph. (1) Recordkeeping. Recordkeeping...

  11. 40 CFR 721.1568 - Substituted benzenediazonium. (United States)


    ... Section 721.1568 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES... to reporting. (1) The chemical substance identified generically as a substituted benzenediazonium... subpart A of this part apply to this section except as modified by this paragraph. (1) Recordkeeping...

  12. 40 CFR 721.1900 - Substituted bromothiophene. (United States)


    ... Section 721.1900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES... reporting. (1) The chemical substance identified generically as substituted bromothiophene (P-83-769) is... this section except as modified by this paragraph. (1) Recordkeeping. The following recordkeeping...

  13. Cadmium substituted high permeability lithium ferrite

    Indian Academy of Sciences (India)


    action becomes weaker than the B–B interaction. This disturbs the parallel arrangement of spin magnetic moments on B-site paving way for canted spins. Zn2+ and Cd2+ substituted ferrites have showed similar type of canting behaviour above a certain limit of their contents. The compositional variation of initial permeability.

  14. Substitution of academically trained by other manpower

    NARCIS (Netherlands)

    J. Tinbergen (Jan)


    textabstractSubstitution von Akademikern durch andere ArbeitskrÄfte. — Dieser Aufsatz berichtet über SchÄtzungen von verschiedenen Autoren über die SubstitutionselastizitÄt zwischen hochqualifizierten (meist akademisch ausgebildeten) und anderen ArbeitskrÄften und befaβt sich mit den möglichen

  15. Substitution between cars within the household

    NARCIS (Netherlands)

    de Borger, B.; Mulalic, I.; Rouwendal, J.


    In this paper we study the demand for car kilometres in two-car households, focusing on the substitution between cars of different fuel efficiency in response to fuel price changes. We use a large sample of detailed Danish data on two-car households to estimate - for each car owned by the household

  16. Economic implications on management earnings of substituting ...

    African Journals Online (AJOL)

    Economic implications on management earnings of substituting traditional for improved cassava varieties in mix cropping farms in Cross River State. ... A sample of one thousand heads of farms family household across the State were interviewed and their records obtained were analysed following the residual claimant ...

  17. 19 CFR 4.99 - Forms; substitution. (United States)


    ... forms so printed: (1) Conform to the official Customs forms in wording arrangement, style, size of type... 19 Customs Duties 1 2010-04-01 2010-04-01 false Forms; substitution. 4.99 Section 4.99 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY...

  18. Additive and Substitutive Borrowing against Semantic Broadening ...

    African Journals Online (AJOL)

    The thrust of this paper lies on semantic changes associated with additive and substitutive borrowing in Bantu-speaking communities in Tanzania. Due to contact of languages, semantic differences of the terms related to architectural structures emanate. Apart from data from a few elderly native speakers, research was ...

  19. Scientific Letter: Homemade heroin substitute causing hallucinations ...

    African Journals Online (AJOL)

    Scientific Letter: Homemade heroin substitute causing hallucinations. TI Lemon. Abstract. No Abstracts. African Journal of Psychiatry • November 2013, 16(6). Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT ·

  20. 3-Substituted 2-phenyl-indoles

    DEFF Research Database (Denmark)

    Johansson, Karl Henrik; Jørgensen, T.B.; Gloriam, D.E.


    -indoles with a variety of substituents at the indole 3-position. Herein we describe the development of optimised and efficient synthetic routes to a series of new 2-phenyl-indole building blocks 3 to 9 and show that these can be used to generate a broad variety of 3-substituted 2-phenyl-indoles of interest to medicinal...

  1. Towards hemerythrin-based blood substitutes: Comparative ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences; Volume 36; Issue 2. Towards hemerythrin-based blood substitutes: Comparative performance to hemoglobin on human leukocytes and umbilical vein endothelial cells. Eva Fischer-Fodor Augustin Mot Florina Deac Mariann Arkosi Radu Silaghi-Dumitrescu. Brief communication ...

  2. Gd-substituted Bi-2223 superconductor

    Indian Academy of Sciences (India)

    Various researchers, who have studied the effect of doping in Bi-based high-Tc superconductors, seem to ... mum temperature for the sintering of the complete series of gadolinium-substituted. (BiPb)-2223 specimens. ..... support (senior research fellowship) and facilities for the work to be carried out. References. [1] V P S ...

  3. Fossil Fuels, Backstop Technologies, and Imperfect Substitution

    NARCIS (Netherlands)

    van der Meijden, G.C.; Pittel, Karen; van der Ploeg, Frederick; Withagen, Cees


    This chapter studies the transition from fossil fuels to backstop technologies in a general equilibrium model in which growth is driven by research and development. The analysis generalizes the existing literature by allowing for imperfect substitution between fossil fuels and the new energy

  4. Substitute fluid examinations for liquid manure (United States)

    Schrader, Kevin; Riedel, Marco; Eichert, Helmut

    For the farming industry it is essential to use liquid manure as natural fertilizer. Through new agricultural regulation 2015 in Germany the industry must develop new liquid manure spreader systems because the ammonia and methane emission are limited. In a research project the University of Applied Sciences Zwickau and some other industry partners will develop such a new innovative liquid manure spreader. The new liquid manure spreader should use pulsating air to distribute the liquid manure exactly. The pulsating air, which flows through the pipelines, should be analysed at a test station. For examinations at this test station it is important to find another substitute fluid because liquid manure smells strong, is not transparent and is also not homogeneous enough for scientific investigations. Furthermore it is important to ensure that the substitute fluid is, like liquid manure, a non-Newtonian fluid. The substitute fluid must be a shear-thinning substance - this means the viscosity decrease at higher shear rate. Many different samples like soap-water-farragoes, jelly-water-farragoes, agar-water-farragoes, soap-ethanol-farragoes and more are, for the project, examined in regard of their physical properties to find the best substitute fluid. The samples are examined at the rotational viscometer for viscosity at various shear rates and then compared with the viscosity values of liquid manure.

  5. Substitute fluid examinations for liquid manure

    Directory of Open Access Journals (Sweden)

    Schrader Kevin


    Full Text Available For the farming industry it is essential to use liquid manure as natural fertilizer. Through new agricultural regulation 2015 in Germany the industry must develop new liquid manure spreader systems because the ammonia and methane emission are limited. In a research project the University of Applied Sciences Zwickau and some other industry partners will develop such a new innovative liquid manure spreader. The new liquid manure spreader should use pulsating air to distribute the liquid manure exactly. The pulsating air, which flows through the pipelines, should be analysed at a test station. For examinations at this test station it is important to find another substitute fluid because liquid manure smells strong, is not transparent and is also not homogeneous enough for scientific investigations. Furthermore it is important to ensure that the substitute fluid is, like liquid manure, a non-Newtonian fluid. The substitute fluid must be a shear-thinning substance - this means the viscosity decrease at higher shear rate. Many different samples like soap-water-farragoes, jelly-water-farragoes, agar-water-farragoes, soap-ethanol-farragoes and more are, for the project, examined in regard of their physical properties to find the best substitute fluid. The samples are examined at the rotational viscometer for viscosity at various shear rates and then compared with the viscosity values of liquid manure.

  6. Consumers' perception of generic substitution in Iran. (United States)

    Yousefi, Nazila; Mehralian, Gholamhossein; Peiravian, Farzad; NourMohammadi, Samaneh


    The growth of pharmaceutical expenditure and patients' out of pocket has motivated policy makers to encourage patients to substitution of brands medicines with their generic alternatives called generic substitution. As the patients are final decision makers to accept generic substitution, the aim of this study is to evaluate the patient perception about generic medicines and underlying factors which can promote the generic acceptance. The study was done in community pharmacies in Tehran, the capital city of Iran. A cross-sectional descriptive study inviting people purchasing their drug at community pharmacies were per-formed using a self-administrated anonymous questionnaire (N=1309). Besides the demographic section, 16 items of developed questionnaire were categorized to five main factors including: patients' perception about efficiency, safety and cost of generic medicines, patient trust on physicians and pharmacists' advice. Findings of completed questionnaires showed among the aforementioned factors the physician has the first priority to encourage patients to use of generics medicines which followed respectively by pharmacist's role, cost of medicines, efficacy, and safety concerns. In conclusion, the trust of Iranian's society on the physicians and pharmacists advice would create a credible opportunity to reduce pharmaceutical expenditures as well as patients' out of pocket by promotion of generic substitution.

  7. Dodecatungstocobaltate and Sn (IV)-Substituted Polyoxometalate ...

    African Journals Online (AJOL)


    because of their unique reactivity, which depends on the compo- sition and structure of the active sites.9 Substituted ... molybdate and sodium tungstate were obtained from Merck and Co(OAc)2.4H2O and potassium persulfate ... The sodium salt was then converted to the potassium salt by treatment with potassium chloride.

  8. chromic transitions in phenyl-substituted polythiophenes

    African Journals Online (AJOL)

    The solvatochromic and thermochromic behaviours of phenyl-substituted polythiophenes were studied. The pristine polymers, upon dissolution in chloroform, exhibited blue-shifted absorption. The solid films of the polymers showed significant blue-shifted as well as red-shifted absorptions when heated. While the addition of ...

  9. Photocatalytic degradation of dye using CeO2/SCB composite catalysts (United States)

    Channei, Duangdao; Nakaruk, Auppatham; Phanichphant, Sukon


    The main task of the present work is to enhance the photocatalytic degradation efficiency of methylene blue (MB) by using CeO2/sugarcane bagasse (SCB) composite catalysts. Homogeneous precipitation method was used to synthesis CeO2-SCB composite catalysts by adding SCB powder to precursor solution of Ce base-metal. The structural analytical data indicated the pure cubic fluorite structure of CeO2. Morphological images revealed the coating of CeO2 layer on high surface area of SCB core-shell. The chemical analysis presented spectrum of the Ce 3d in CeO2/SCB sample existed in the form of the Ce3 + and Ce4 + mixed- valence states. Optical spectra showed the shift of absorption edge towards longer visible region upon supporting CeO2 with SCB. The main chemical composition of the SCB was K, Ca, and Si. Furthermore, recombination of the photogenerated electrons and holes was identified by photoluminescence techniques (PL), the data suggested inhibition of electron-hole pairs recombination by the cations from SCB loaded in CeO2/SCB composite. Photocatalytic activity of CeO2/SCB catalyst was investigated via the degradation of MB under UV-A irradiation. Experimental kinetic data followed the pseudo-first order model. CeO2 supported with SCB adsorbent had higher photocatalytic activity in dye wastewater treatment compared to the pure CeO2. The proposed mechanism explaining the high photocatalytic efficiency of CeO2/SCB was associated with high surface properties and the suppression of recombination of the photogenerated electron-hole pairs by the SCB adsorbent.

  10. Air, aqueous and thermal stabilities of Ce3+ ions in cerium oxide nanoparticle layers with substrates

    KAUST Repository

    Naganuma, Tamaki


    Abundant oxygen vacancies coexisting with Ce3+ ions in fluorite cerium oxide nanoparticles (CNPs) have the potential to enhance catalytic ability, but the ratio of unstable Ce3+ ions in CNPs is typically low. Our recent work, however, demonstrated that the abundant Ce3+ ions created in cerium oxide nanoparticle layers (CNPLs) by Ar ion irradiation were stable in air at room temperature. Ce valence states in CNPs correlate with the catalytic ability that involves redox reactions between Ce3+ and Ce4+ ions in given application environments (e.g. high temperature in carbon monoxide gas conversion and immersion conditions in biomedical applications). To better understand the mechanism by which Ce3+ ions achieve stability in CNPLs, we examined (i) extra-long air-stability, (ii) thermal stability up to 500 °C, and (iii) aqueous stability of Ce 3+ ions in water, buffer solution and cell culture medium. It is noteworthy that air-stability of Ce3+ ions in CNPLs persisted for more than 1 year. Thermal stability results showed that oxidation of Ce 3+ to Ce4+ occurred at 350 °C in air. Highly concentrated Ce3+ ions in ultra-thin CNPLs slowly oxidized in water within 1 day, but stability was improved in the cell culture medium. Ce 3+ stability of CNPLs immersed in the medium was associated with phosphorus adsorption on the Ce3+ sites. This study also illuminates the potential interaction mechanisms of stable Ce3+ ions in CNPLs. These findings could be utilized to understand catalytic mechanisms of CNPs with abundant oxygen vacancies in their application environments. © The Royal Society of Chemistry 2014.

  11. Preparation of the Drager Fabius CE and Drager Zeus anaesthetic machines for patients susceptible to malignant hyperthermia. (United States)

    Shanahan, Hiliary; O'Donoghue, Rory; O'Kelly, Patrick; Synnott, Aidan; O'Rourke, James


    Malignant hyperthermia may follow exposure to trace quantities of inhalational anaesthetics. In susceptible patients, the complete avoidance of these triggers is advised when possible; however, failing this, it is essential to washout or purge the anaesthesia machine of residual inhalational anaesthetics. This study examined the washout profile of sevoflurane from the Drager Fabius CE and the Drager Zeus machines. The washout profile of sevoflurane was measured from the Fabius CE and Zeus anaesthesia machines following a standard period of exposure. The disposable tubing, CO2 absorber and other components of each machine were then replaced to examine their impact on the retention of sevoflurane. The effect of autoclaving the ventilator diaphragm and non-disposable ventilator tube or substituting for a new diaphragm and ventilation tube were examined in later parts of this study. University teaching hospital. Time taken to reach 5 parts per million of sevoflurane when machines underwent standard washout with fresh gas flush. The concentration of sevoflurane reached 5 parts per million in the Fabius CE machines after an mean (SD) of 140 min (46) at a fresh gas flow (FGF) of 10 l min(-1). The time taken for sevoflurane to reach 5 parts per million was significantly reduced when the ventilator diaphragm and non-disposable tube were replaced with either new or autoclaved components [14 or 22 min, respectively (P = 0.017, P = 0.031)]. The concentration of sevoflurane reached 5 parts per million in the Zeus machines after an mean (SD) of 85 min (6) at a fresh gas flow of 10 l min(-1). When the fresh gas flow was increased to 18 l min(-1) (the maximum allowable), the time to reach 5 parts per million was reduced to 16 min. When preparing the Fabius CE for the malignant hyperthermia susceptible patient, remove the vaporiser, replace the disposable tubing, the reservoir bag and the CO2 absorber. Replace the ventilator diaphragm and non-disposable ventilator tube with new or

  12. Element specific electronic states and spin-flip-like behavior of Ce in (Ce0.2Gd0.8)Ni composed of heavy fermion CeNi and ferri-magnet GdNi through XMCD method (United States)

    Yano, K.; Okane, T.; Takeda, Y.; Yamagami, H.; Fujimori, A.; Nishimura, K.; Sato, K.


    The electronic states of the three constituent elements in the crystal mixed system between CeNi and GdNi, Ce0.2Gd0.8Ni, were investigated by soft X-ray magnetic circular dichroism (XMCD) with the aid of sum rule analysis. Not only Gd 4f but also Ni 3d and Ce 4f electrons were magnetic and both magnetic moments of Ni and Ce were coupled anti-parallel to the direction of the Gd magnetic moment, which is in accordance with the general rule in rare earth (RE)-transition metal (TM) systems. After saturation, Ce magnetic moment decreased over 2 T and this behavior was explained by a spin-flip behavior of the Ce magnetic moment with keeping their electronic states unchanged. Furthermore, the magnetic field dependence on a part of the XAS at Ce M4,5 absorption edges, which had been observed in the Gd=0.5 disappeared in the present sample in Gd-rich content of 0.8 and this could be explained by the increase of molecular field from Gd on Ce 4f electrons. In addition, sum rule analysis has revealed that the magnetic moments of Gd 4 f and Ni 3d electrons could retain small values of angular (orbital) magnetic moments μL and this was explained consistently.

  13. Hand-held survey probe (United States)

    Young, Kevin L [Idaho Falls, ID; Hungate, Kevin E [Idaho Falls, ID


    A system for providing operational feedback to a user of a detection probe may include an optical sensor to generate data corresponding to a position of the detection probe with respect to a surface; a microprocessor to receive the data; a software medium having code to process the data with the microprocessor and pre-programmed parameters, and making a comparison of the data to the parameters; and an indicator device to indicate results of the comparison. A method of providing operational feedback to a user of a detection probe may include generating output data with an optical sensor corresponding to the relative position with respect to a surface; processing the output data, including comparing the output data to pre-programmed parameters; and indicating results of the comparison.

  14. Spaser as a biological probe (United States)

    Galanzha, Ekaterina I.; Weingold, Robert; Nedosekin, Dmitry A.; Sarimollaoglu, Mustafa; Nolan, Jacqueline; Harrington, Walter; Kuchyanov, Alexander S.; Parkhomenko, Roman G.; Watanabe, Fumiya; Nima, Zeid; Biris, Alexandru S.; Plekhanov, Alexander I.; Stockman, Mark I.; Zharov, Vladimir P.


    Understanding cell biology greatly benefits from the development of advanced diagnostic probes. Here we introduce a 22-nm spaser (plasmonic nanolaser) with the ability to serve as a super-bright, water-soluble, biocompatible probe capable of generating stimulated emission directly inside living cells and animal tissues. We have demonstrated a lasing regime associated with the formation of a dynamic vapour nanobubble around the spaser that leads to giant spasing with emission intensity and spectral width >100 times brighter and 30-fold narrower, respectively, than for quantum dots. The absorption losses in the spaser enhance its multifunctionality, allowing for nanobubble-amplified photothermal and photoacoustic imaging and therapy. Furthermore, the silica spaser surface has been covalently functionalized with folic acid for molecular targeting of cancer cells. All these properties make a nanobubble spaser a promising multimodal, super-contrast, ultrafast cellular probe with a single-pulse nanosecond excitation for a variety of in vitro and in vivo biomedical applications.

  15. Controlled hydrothermal synthesis of CeO{sub 2} nanospheres and their excellent magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Xiaofei [Suzhou University, Anhui Key Laboratory of Spintronics and Nanomaterials Research, Suzhou, Anhui (China)


    Monodisperse spherical CeO{sub 2} nanostructures with irregular and rough surfaces have successfully been synthesized via a facile hydrothermal technology. XRD, SEM, XPS, Raman scattering, and M-H curves were employed to characterize the samples. The results showed that the spherical CeO{sub 2} nanostructures have a cubic fluorite structure and that there are Ce{sup 3+} ions and oxygen vacancies in the surface of the samples. The M-H curve of CeO{sub 2} nanospheres exhibits excellent room-temperature ferromagnetism (RT-FM), which is likely ascribed to the effects of the Ce{sup 3+} ions and oxygen vacancies. (orig.)

  16. LiCaAlF sub 6 :Ce crystal: a new scintillator

    CERN Document Server

    Gektin, A V; Neicheva, S; Gavrilyuk, V; Bensalah, A; Fukuda, T; Shimamura, K


    Scintillation properties of LiCaAlF sub 6 :Ce crystal, well known as the effective UV laser material, is reported. Ce sup 3 sup + emission at 286-305 nm with a single exponential decay time of 35 ns provides a scintillation pulse. Radiation damage in pure and Ce-doped crystals is studied. In contrast to the majority of fluoride crystals, cerium is responsible for the ultradeep traps formation revealing thermostimulated luminescence. Overlapping of color center absorption and Ce sup 3 sup + ion emission bands limits the scintillation efficiency of LiCaAlF sub 6 :Ce at high radiation doses.

  17. X-ray diffraction study on thermal properties of crystal lattices in CeP and CeAs

    Energy Technology Data Exchange (ETDEWEB)

    Iwasa, Kazuaki; Kohgi, Masafumi [Department of Physics, Faculty of Science, Tokyo Metropolitan University, Hachioji, Tokyo (Japan); Ohsumi, Hiroyuki; Tajima, Keisuke; Takeuchi, Tetsuya; Haga, Yoshinori; Uesawa, Akihiro; Suzuki, Takashi


    X-ray diffraction studies at low temperatures have been performed in order to investigate thermal properties of crystal lattices in the low-carrier-density systems cerium monopnictides. CeP and CeAs show large crystal-lattice contractions with increasing temperatures up to about 120K and 90K, respectively. Due to the strong p-f mixing, the excited crystal {Gamma}{sub 8}-like state is expected to produce a shorter interatomic bond length between cerium ions and neighboring pnictogens than that realized by the {Gamma}{sub 7} ground state. The experimental results of the lattice contractions at low temperatures are explained by the thermal average of these crystal field states. (author)

  18. Permittivity measurements using coaxial probes


    Oliver Riera, Bartomeu


    The main objective of this thesis is to characterize, using the ADS software, the coaxial probe provided by the faculty ETSETB and utilize such probe in order to calculate the permittivity of different materials El objetivo principal de esta tesis el de caracterizar, con el programa ADS, la sonda coaxial proporcionada por la facultad de la ETSETB y utilizar-la para el calculo de la permitividad de diferentes materiales. L'objectiu d'aquesta tesis es el de caracteritzar, amb el programa ...

  19. Radioactive Probes on Ferromagnetic Surfaces

    CERN Document Server


    On the (broad) basis of our studies of nonmagnetic radioactive probe atoms on magnetic surfaces and at interfaces, we propose to investigate the magnetic interaction of magnetic probe atoms with their immediate environment, in particular of rare earth (RE) elements positioned on and in ferromagnetic surfaces. The preparation and analysis of the structural properties of such samples will be performed in the UHV chamber HYDRA at the HMI/Berlin. For the investigations of the magnetic properties of RE atoms on surfaces Perturbed Angular Correlation (PAC) measurements and Mössbauer Spectroscopy (MS) in the UHV chamber ASPIC (Apparatus for Surface Physics and Interfaces at CERN) are proposed.

  20. Probe Project Status and Accomplishments

    Energy Technology Data Exchange (ETDEWEB)

    Burris, RD


    The Probe project has completed its first full year of operation. In this document we will describe the status of the project as of December 31, 2000. We will describe the equipment configuration, then give brief descriptions of the various projects undertaken to date. We will mention first those projects performed for outside entities and then those performed for the benefit of one of the Probe sites. We will then describe projects that are under consideration, including some for which initial actions have been taken and others which are somewhat longer-term.

  1. The stable Ce.sup.4+./sup. center: a new tool to optimize Ce-doped oxide scintillators

    Czech Academy of Sciences Publication Activity Database

    Nikl, Martin; Babin, Vladimir; Pejchal, Jan; Laguta, Valentyn; Buryi, Maksym; Mareš, Jiří A.; Kamada, K.; Kurosawa, S.; Yoshikawa, A.; Pánek, D.; Parkman, T.; Brůža, Petr; Mann, K.; Müller, M.


    Roč. 63, č. 2 (2016), s. 433-438 ISSN 0018-9499 R&D Projects: GA ČR GJ15-18300Y; GA MŠk(CZ) LG13029 Institutional support: RVO:68378271 Keywords : Ce 4+ * gamma-ray detection * LuAG * scintillator * X-ray detection Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.171, year: 2016

  2. Preparation and catalytic behavior of CeO2 nanoparticles on Al2O3 crystal (United States)

    Hattori, Takashi; Kobayashi, Katsutoshi; Ozawa, Masakuni


    In this work, we examined the preparation, morphology, and catalytic behavior of CeO2 nanoparticles (NPs) on Al2O3(0001) crystal substrates. A CeO2 NP layer was prepared by the dipping method using a CeO2 nanocrystal colloid solution. Even after heat treatment at 1000 °C, the CeO2 NP layer maintained the granular morphology of CeO2 with a grain diameter of less than 40 nm. CeO2 NPs on an Al2O3 crystal showed higher oxidation activity for gaseous hydrogen at moderate temperatures and enhanced oxygen release properties of CeO2, compared with CeO2 powder. This was due to the highly dispersed CeO2 NPs and the interaction between CeO2 NPs and Al2O3; this clarified the importance of the Al2O3 support for the CeO2 catalyst.

  3. Tetragonal Ce-based Ce-Sm(Fe, Co, Ti){sub 12} alloys for permanent magnets

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Cid, Andres; Salazar, Daniel [BCMaterials, Bizkaia Science and Tecnology Park, 48160 Derio (Spain); Gabay, Aleksandr M.; Hadjipanayis, George C. [Department of Physics and Astronomy, University of Delaware, Newark, DE, 19716 (United States); Barandiaran, Jose Manuel [BCMaterials, Bizkaia Science and Tecnology Park, 48160 Derio (Spain); Department of Electricity and Electronics, University Basque Country (UPV/EHU), 48080 Bilbao (Spain)


    Abundance and relatively low cost of Ce provide a great incentive for its use in rare-earth permanent magnets. It has been recently reported that the tetragonal Ce(Fe,Co,Ti)12 compounds may exhibit application-worthy intrinsic magnetic properties. In this work the effect of the α-Fe phase formation due to the evaporation of Sm during alloy fabrication has been studied, as a previous step in the attempt to convert the intrinsic magnetic properties into functional properties of a permanent magnet. Ce{sub 0.5}Sm{sub 0.5}Fe{sub 9}Co{sub 2}Ti alloys based on the ThMn12-type crystal structure have been synthesized via melt-spinning with different Sm content. Coercive fields between 2.8 and 1.4 kOe have been found for α-Fe phase contents between 8 and 46% in volume, showing the influence of the α-Fe phase on the coercivity and exchange coupling between the hard and soft phase. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Experimental and theoretical study about sulfur deactivation of Ni/ CeO{sub 2} and Rh/CeO{sub 2} catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Ocsachoque, Marco A., E-mail: [Centro de Investigación y Desarrollo en Ciencias Aplicadas “Dr Jorge J. Ronco”, (CONICET, CCT La Plata), Departamento de Química, Facultad de Cs Exactas (UNLP), Calle 48 N° 257, 1900 La Plata (Argentina); Eugenio Russman, Juan I.; Irigoyen, Beatriz [Instituto de Tecnologías del Hidrógeno y Energías Sostenibles (ITHES), Departamento de Ingeniería Química, Facultad de Ingeniería (UBA), Buenos Aires (Argentina); Gazzoli, Delia [Dipartimento di Chimia, Universitá di Roma “La Sapienza”, Roma (Italy); González, María G. [Centro de Investigación y Desarrollo en Ciencias Aplicadas “Dr Jorge J. Ronco”, (CONICET, CCT La Plata), Departamento de Química, Facultad de Cs Exactas (UNLP), Calle 48 N° 257, 1900 La Plata (Argentina)


    Sulfur deactivation of Ni/CeO{sub 2} and Rh/CeO{sub 2} catalysts were examined through an experimental and theoretical study. These catalysts were characterized by N{sub 2} adsorption, X-ray diffraction, temperature programmed reaction, thermogravimetric analysis, Uv–visible spectroscopy and Raman spectroscopy, and tested under the methane dry reforming reaction in the presence of H{sub 2}S. On the other hand, different possible interactions of sulfur with Rh, Ni or surface sites of the CeO{sub 2} support were evaluated by performing energy calculations with the density functional theory (DFT). Overall, the results indicate that tolerance to sulfur of Rh/CeO{sub 2} catalyst is higher than that of Ni/CeO{sub 2} one. In this sense, TPR measurements show that reduction of CeO{sub 2} is promoted by the presence of Rh. This effect, probably caused by hydrogen spillover to CeO{sub 2} support during the reduction of RhO{sub x} species, could be linked to a high oxygen donation capacity of Rh/CeO{sub 2} catalysts. Accordingly, the O{sup 2−} species existing on Rh/CeO{sub 2} catalysts, revealed by Raman spectra of these samples, could favor sulfur oxidation and prevent Rh–S interactions. Likewise, the theoretical calculations show that desorption of S–O species from Rh/CeO{sub 2} system is more favorable than that from Ni/CeO{sub 2} one. Therefore, our experimental and theoretical study about sulfur deactivation of Ni and Rh supported on CeO{sub 2} allow us to postulate that Rh can help to desorb SO{sub x} species formed on the support, retarding sulfur poisoning of the Rh/CeO{sub 2} catalysts. - Highlights: • CeO{sub 2} support can act as a sacrifice trap decreasing sulfur poisoning. • Theoretical calculations indicate an important nickel affinity with sulfur. • Rh would favor desorption of S–O species formed on the support. • The O{sup 2−} species present on the Rh–CeO{sub 2} sample favor sulfur removal.

  5. Facile preparation of self-healing superhydrophobic CeO2 surface by electrochemical processes (United States)

    Nakayama, Katsutoshi; Hiraga, Takuya; Zhu, Chunyu; Tsuji, Etsushi; Aoki, Yoshitaka; Habazaki, Hiroki


    Herein we report simple electrochemical processes to fabricate a self-healing superhydrophobic CeO2 coating on Type 304 stainless steel. The CeO2 surface anodically deposited on flat stainless steel surface is hydrophilic, although high temperature-sintered and sputter-deposited CeO2 surface was reported to be hydrophobic. The anodically deposited hydrophilic CeO2 surface is transformed to hydrophobic during air exposure. Specific accumulation of contaminant hydrocarbon on the CeO2 surface is responsible for the transformation to hydrophobic state. The deposition of CeO2 on hierarchically rough stainless steel surface produces superhydrophobic CeO2 surface, which also shows self-healing ability; the surface changes to superhydrophilic after oxygen plasma treatment but superhydrophobic state is recovered repeatedly by air exposure. This work provides a facile method for preparing a self-healing superhydrophobic surface using practical electrochemical processes.

  6. Luminescent properties of Tm3-xLuxAl5O12:Ce single crystalline films (United States)

    Zorenko, Yu.; Gorbenko, V.; Zorenko, T.; Suchocki, A.; Zhydachevskyy, Ya.; Fabisiak, K.; Paprocki, K.; Bilski, P.; Twardak, A.; Fedorov, A.


    The work devoted to the investigation of a new luminescent and scintillation material based on the single crystalline films (SCFs) of Tm3-xLuxAG:Ce garnet; x = 0-1.5, grown by LPE method from PbO based flux. The best scintillation properties are achieved for SCFs of Tm1.5Lu1.5Al5O12:Ce composition. We have found that direct Tm → Ce and backside Ce → Tm energy transfer processes are observed in Tm1.5Lu1.5Al5O12:Ce. Due to elimination of traps in the 300-450 °C range, the relatively fast scintillation decay is realized in highly doped Tm1.5Lu1.5Al5O12:Ce SCFs. For this reason, Tm doping can be considered as a suitable way for improvement of the scintillation efficiency in other Ce3+ doped garnet compounds.

  7. Substitution treatment for opioid addicts in Germany

    Directory of Open Access Journals (Sweden)

    Gerlach Ralf


    Full Text Available Abstract Background After a long and controversial debate methadone maintenance treatment (MMT was first introduced in Germany in 1987. The number of patients in MMT – first low because of strict admission criteria – increased considerably since the 1990s up to some 65,000 at the end of 2006. In Germany each general practitioner (GP, who has completed an additional training in addiction medicine, is allowed to prescribe substitution drugs to opioid dependent patients. Currently 2,700 GPs prescribe substitution drugs. Psychosocial care should be made available to all MMT patients. Results The results of research studies and practical experiences clearly indicate that patients benefit substantially from MMT with improvements in physical and psychological health. MMT proves successful in attaining high retention rates (65 % to 85 % in the first years, up to 50 % after more than seven years and plays a major role in accessing and maintaining ongoing medical treatment for HIV and hepatitis. MMT is also seen as a vital factor in the process of social re-integration and it contributes to the reduction of drug related harms such as mortality and morbidity and to the prevention of infectious diseases. Some 10 % of MMT patients become drug-free in the long run. Methadone is the most commonly prescribed substitution medication in Germany, although buprenorphine is attaining rising importance. Access to MMT in rural areas is very patchy and still constitutes a problem. There are only few employment opportunities for patients participating in MMT, although regular employment is considered unanimously as a positive factor of treatment success. Substitution treatment in German prisons is heterogeneous in access and treatment modalities. Access is very patchy and the number of inmates in treatment is limited. Nevertheless, substitution treatment plays a substantial part in the health care system provided to drug users in Germany. Conclusion In Germany, a

  8. Substitution treatment for opioid addicts in Germany (United States)

    Michels, Ingo Ilja; Stöver, Heino; Gerlach, Ralf


    Background After a long and controversial debate methadone maintenance treatment (MMT) was first introduced in Germany in 1987. The number of patients in MMT – first low because of strict admission criteria – increased considerably since the 1990s up to some 65,000 at the end of 2006. In Germany each general practitioner (GP), who has completed an additional training in addiction medicine, is allowed to prescribe substitution drugs to opioid dependent patients. Currently 2,700 GPs prescribe substitution drugs. Psychosocial care should be made available to all MMT patients. Results The results of research studies and practical experiences clearly indicate that patients benefit substantially from MMT with improvements in physical and psychological health. MMT proves successful in attaining high retention rates (65 % to 85 % in the first years, up to 50 % after more than seven years) and plays a major role in accessing and maintaining ongoing medical treatment for HIV and hepatitis. MMT is also seen as a vital factor in the process of social re-integration and it contributes to the reduction of drug related harms such as mortality and morbidity and to the prevention of infectious diseases. Some 10 % of MMT patients become drug-free in the long run. Methadone is the most commonly prescribed substitution medication in Germany, although buprenorphine is attaining rising importance. Access to MMT in rural areas is very patchy and still constitutes a problem. There are only few employment opportunities for patients participating in MMT, although regular employment is considered unanimously as a positive factor of treatment success. Substitution treatment in German prisons is heterogeneous in access and treatment modalities. Access is very patchy and the number of inmates in treatment is limited. Nevertheless, substitution treatment plays a substantial part in the health care system provided to drug users in Germany. Conclusion In Germany, a history of substitution

  9. Fluorescence probe for the convenient and sensitive detection of ascorbic acid. (United States)

    Matsuoka, Yuta; Yamato, Mayumi; Yamada, Ken-Ichi


    Ascorbic acid is an important antioxidant that plays an essential role in the biosynthesis of numerous bioactive substances. The detection of ascorbic acid has traditionally been achieved using high-performance liquid chromatography and absorption spectrophotometry assays. However, the development of fluorescence probes for this purpose is highly desired because they provide a much more convenient and highly sensitive technique for the detection of this material. OFF-ON-type fluorescent probes have been developed for the detection of non-fluorescent compounds. Photo-induced electron transfer and fluorescence resonance energy transfer are the two main fluorescence quenching mechanisms for the detection of ascorbic acid, and several fluorescence probes have been reported based on redox-responsive metals and quantum dots. Profluorescent nitroxide compounds have also been developed as non-metal organic fluorescence probes for ascorbic acid. These nitroxide systems have a stable unpaired electron and can therefore react with ascorbic acid and a strong fluorescence quencher. Furthermore, recent synthetic advances have allowed for the synthesis of α-substituted nitroxides with varying levels of reactivity towards ascorbic acid. In this review, we have discussed the design strategies used for the preparation of fluorescent probes for ascorbic acid, with particular emphasis on profluorescent nitroxides, which are unique radical-based redox-active fluorescent probes.

  10. Manganese/cerium clusters spanning a range of oxidation levels and CeMn(8), Ce(2)Mn(4), and Ce(6)Mn(4) nuclearities: structural, magnetic, and EPR properties. (United States)

    Lampropoulos, Christos; Thuijs, Annaliese E; Mitchell, Kylie J; Abboud, Khalil A; Christou, George


    The syntheses, structures, and magnetic properties are reported for three new Ce/Mn clusters with different Ce/Mn ratios: [Ce6Mn4O12(O2CMe)10(NO3)4(py)4] (py = pyridine) (1), [CeMn8O8(O2CCH2(t)Bu)12(DMF)14] (DMF = dimethylformamide) (2), and [Ce2Mn4O2(O2CMe)6(NO3)4(hmp)4] (3; hmp(-) is the anion of 2-(hydroxymethyl)pyridine). 1 and 2 were obtained from the reaction of Ce(IV) with [Mn12O12(O2CMe)16(H2O)4] (Mn(III)8Mn(IV)4) and [Mn8O2(O2CCH2(t)Bu)14((t)BuCH2CO2H)4] (Mn(II)6Mn(III)2), respectively, whereas 3 resulted from the oxidation of Mn(II) acetate with Ce(IV) in the presence of hmpH. Cluster 1 possesses an unusual [Ce6Mn4O12](14+) core topology consisting of a [Ce6O8] face-capped octahedron, which is face-fused at each end to a [Ce(IV)2Mn(III)Mn(IV)O4] cubane. Cluster 2 possesses a nonplanar, saddlelike loop of eight Mn(III) atoms bridged by eight μ3-O(2-) ions to a central Ce(IV) atom. Cluster 3 is similar to 1 in possessing an octahedral core, but this is now a [Ce2Mn4] octahedron consisting of a Ce(III) atom on either side of a Mn4 parallelogram, with the metal atoms bridged by two μ4-O(2-) ions, the alkoxide arms of four hmp(-) groups, and six acetates. Clusters 1, 2, and 3 are thus at the Ce(IV)6Mn(III)2Mn(IV)2, Ce(IV)Mn(III)8, and Ce(III)2Mn(III)4 oxidation levels, respectively. Variable-temperature, solid-state direct current (DC) and alternating current (AC) magnetization studies on 1-3 in the 5.0-300 K range revealed predominantly antiferromagnetic exchange interactions within the complexes. For 1, fitting of the DC data to the theoretical expression for a dinuclear Mn(III)Mn(IV) complex derived using the Van Vleck equation and an isotropic spin Hamiltonian (ℋ = -2JŜi·Ŝj convention) gave a value for the exchange coupling parameter (J) of -60.4(7) cm(-1) and a Landé factor g = 2.00(1), indicating an S = 1/2 ground state. For 2, both DC and AC data indicate an S = 0 ground state, which is unprecedented for a member of the CeMn8 family and now

  11. Ultraviolet and near-infrared luminescence of LaBO3:Ce3+,Yb3+ (United States)

    Wei, Heng-Wei; Shao, Li-Ming; Jiao, Huan; Jing, Xi-Ping


    Ce3+ or Yb3+ singly doped LaBO3 and Ce3+-Yb3+ co-doped LaBO3 were prepared by conventional solid state reactions at 1100 °C and their photoluminescence (PL) properties were investigated. The emission spectrum of LaBO3:Ce3+,Yb3+ contains both the Ce3+ ultraviolet (UV) emissions (355 nm and 380 nm) and the Yb3+ near infrared (NIR) emission (975 nm) when excited by the UV light at 270 nm. By using the data of the Ce3+ decay curves and the PL intensities of both Ce3+ and Yb3+, the energy transfer efficiency (η) from Ce3+ to Yb3+, the actual energy transfer efficiency (AE) and the quantum efficiency (Q) of the Yb3+ emission were calculated. In the Ce3+-Yb3+ co-doped LaBO3, Ce3+ can transfer its absorbed energy to Yb3+ efficiently (η can be over 60%), and Yb3+ shows the Q value over 50% when it accepts the energy from Ce3+, which results in the low AE value ∼30%. The energy transfer process from Ce3+ to Yb3+ may be understood by the charge transfer mechanism: Ce3+ + Yb3+ ↔ Ce4+ + Yb2+. Particularly the Ce3+-Yb3+ co-doped LaBO3 phosphor gives the emissions mainly in the UV range and the NIR range with a portion of visible emissions in eye-insensitive range. This unique property may be suitable for applications in anti-counterfeiting techniques and public security affairs.

  12. [The substitution effect of leadership substitutes for transformational leadership in nursing organization]. (United States)

    Kim, Jeong-Hee


    This paper was conducted to examine the effects of transformational leadership behaviors, within the substitutes for leadership model (Kerr & Jermier, 1978). Data was collected from 181 staff nurses in 3 general hospitals, with self-reporting questionnaires (MLQ developed by Bass, rd-SLS developed by Podsakoff, et al., and MSQ developed by Weiss, et al.). Descriptive statistics, factor analysis, Cronbach's alpha and moderated regression analysis were used. 1) The transformational leader behaviors and substitutes for leadership each had correlations with job satisfaction. 2) The total amount of variance accounted for by the substitutes for leadership was substantially greater than by the transformational leadership behaviors. 3) Few of the substitutes variables moderated the relationships between the transformational leader behaviors and job satisfaction in a manner consistent with that specified by Howell, Dorfman, and Kerr (1986). The finding of this study suggest that leaders need to have a better understanding of those contextual variables that influence job satisfaction. Thus future research should focus attention on the moderating effects of substitutes, as well as the things that leaders can do to influence them. In addition, it may be good to examine the effects of substitutes on other criterion variables.

  13. Upconversion color tuning in Ce(3+)-doped LiYF(4):Yb(3+)/Ho(3+)@LiYF(4) nanoparticles towards ratiometric fluorescence detection of chromium(III). (United States)

    Liu, Shijiang; Li, Yangjie; Zhang, Cheng; Yang, Liang; Zhao, Tingting; Zhang, Ruilong; Jiang, Changlong


    Ratiometric fluorescence sensor exhibits advantages of sensitive response, high anti-interference ability and naked eye visualization owing to multiple independent emission peaks utilized for results analysis. To achieve such multi-emission probe, the traditional methods have involved simple mixing of two emitters or tedious synthesis processes of hybrid material. However, these probes often have problems of inconstant emission strength ratio, low light-stability, and complicated synthetic process, which limit their applications in practical field. Herein, we report a single-structure Ce3+-doped LiYF4:Yb3+/Ho3+@LiYF4 upconversion nanoparticles (UCNPs), which features two emission peaks in the green (at 540nm) and red (at 640nm) region under the excitation of 980nm near infrared laser. Importantly, the red/green intensity ratio can be regulated by changing the doping level of Ce3+ to modulate output colors. Furthermore, a Cr3+-responsive rhodamine derivative (CRD) was modified on the devised UCNPs surface to fabricate the colorimetric probe by luminescent resonance energy transfer (LRET) process. Upon addition of Cr3+ into the probe solution, the absorption peak of CRD at 560nm is significantly enhanced, which greatly reduced the green emission, leading to an obvious color evolution from green to yellow to orange and to red with increasing the concentration of Cr3+. This method is successfully applied to practical detection of Cr3+ ion in industrial waste water. The work reported here demonstrates a useful way to construct color-based visual assays. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Evaluation of cultured human dermal- and dermo-epidermal substitutes focusing on extracellular matrix components: Comparison of protein and RNA analysis. (United States)

    Oostendorp, Corien; Meyer, Sarah; Sobrio, Monia; van Arendonk, Joyce; Reichmann, Ernst; Daamen, Willeke F; van Kuppevelt, Toin H


    Treatment of full-thickness skin defects with split-thickness skin grafts is generally associated with contraction and scar formation and cellular skin substitutes have been developed to improve skin regeneration. The evaluation of cultured skin substitutes is generally based on qualitative parameters focusing on histology. In this study we focused on quantitative evaluation to provide a template for comparison of human bio-engineered skin substitutes between clinical and/or research centers, and to supplement histological data. We focused on extracellular matrix proteins since these components play an important role in skin regeneration. As a model we analyzed the human dermal substitute denovoDerm and the dermo-epidermal skin substitute denovoSkin. The quantification of the extracellular matrix proteins type III collagen and laminin 5 in tissue homogenates using western blotting analysis and ELISA was not successful. The same was true for assaying lysyl oxidase, an enzyme involved in crosslinking of matrix molecules. As an alternative, gene expression levels were measured using qPCR. Various RNA isolation procedures were probed. The gene expression profile for specific dermal and epidermal genes could be measured reliably and reproducibly. Differences caused by changes in the cell culture conditions could easily be detected. The number of cells in the skin substitutes was measured using the PicoGreen dsDNA assay, which was found highly quantitative and reproducible. The (dis) advantages of assays used for quantitative evaluation of skin substitutes are discussed. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  15. Partial substitution of manganese with cerium in SrMnO{sub 3} nano-perovskite catalyst. Effect of the modification on the catalytic combustion of dilute acetone

    Energy Technology Data Exchange (ETDEWEB)

    Rezlescu, Nicolae, E-mail: [National Institute of Research and Development for Technical Physics, Iasi (Romania); Rezlescu, Elena; Popa, Paul Dorin; Doroftei, Corneliu [National Institute of Research and Development for Technical Physics, Iasi (Romania); Ignat, Maria [“Al. I. Cuza” University, Faculty of Chemistry, Iasi (Romania)


    Ultrafine SrMn{sub 1−x}Ce{sub x}O{sub 3} (x = 0, 02) perovskites were prepared by self-combustion method and heat treatment at 1000 °C for 4 h. The structure and surface properties were investigated by X-ray powder diffraction, scanning electron microscopy (SEM), EDX spectroscopy, and BET analysis. The catalyst properties of the perovskite nanopowders were tested in the catalytic combustion of dilute acetone at atmospheric pressure. The results revealed that the partial substitution of Mn by Ce ions (x = 0.2) in perovskite structure of SrMnO{sub 3} had significantly improved catalytic activity of the perovskite. The SrMn{sub 0.8}Ce{sub 0,2}O{sub 3} perovskite composition can be a good candidate for catalytic combustion of low concentration acetone (1–2‰ in air) at low temperatures. The acetone conversion over this catalyst exceeds 90% at 200 °C, whereas over SrMnO{sub 3} it is only 50%. Compared with SrMnO{sub 3}, T{sub 50} is decreased by 75 °C and T{sub 90} is decreased by 70 °C. The enhancement of the catalytic activity at a Ce doping of 0.2 may be ascribed to smaller crystallite sizes, larger specific surface area and the presence of Ce and Mn cations with variable valence in the perovskite structure. - Highlights: • A non-conventional method was used to make nanostructured perovskite samples. • XRD study confirms perovskite structure and nanosize of crystallites. • EDX analyses confirm homogeneity and purity of the samples. • The catalytic testing was carried out in the flameless combustion of dilute acetone. • SrMn{sub 0.8}Ce{sub 0.2}O{sub 3} perovskite can be a promising catalyst for acetone combustion at low temperature.

  16. A novel recipe to improve the magnetic properties of Mn doped CeO{sub 2} as a room temperature ferromagnetic diluted metal oxide

    Energy Technology Data Exchange (ETDEWEB)

    Al-Agel, Faisal A., E-mail: [King Abdulaziz University, Faculty of Science, Department of Physics, Jeddah (Saudi Arabia); Al-Arfaj, Esam [Umm Alqura University, Department of Physics, Makkah (Saudi Arabia); Al-Ghamdi, Ahmed A. [King Abdulaziz University, Faculty of Science, Department of Physics, Jeddah (Saudi Arabia); Losovyj, Yaroslav [Indiana University, Department of Chemistry, Bloomington, IN 47405 (United States); Bronstein, Lyudmila M. [King Abdulaziz University, Faculty of Science, Department of Physics, Jeddah (Saudi Arabia); Indiana University, Department of Chemistry, Bloomington, IN 47405 (United States); Mahmoud, Waleed E. [King Abdulaziz University, Faculty of Science, Department of Physics, Jeddah (Saudi Arabia); Suez Canal University, Faculty of Science, Department of Physics, Ismailia (Egypt)


    Mn doped ceria nanocrystals have been prepared using hexamethylene triperoxide diamine assisted solvothermal technique for the first time. The impact of this novel recipe on the structure, magnetic and spectroscopic behaviors was discussed. The doped oxides were studied using X-ray powder diffraction (XRD), transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), and magnetic measurements. The XRD analysis revealed that all the powders can be indexed to the pure cubic ceria, revealing complete solubility of Mn atoms in the ceria crystal structure with an interstitial substitution of Mn in the Ce sites. At the percolation concentration x=0.08 (Mn{sub 0.08}Ce{sub 0.92}O{sub 2}), the Mn doped cerium oxide displays a very high saturation magnetization of 4.48 emu/g and coercivity of 175.5 Oe. The enhanced magnetic properties are attributed to the formation of the complex between the Mn ion and an oxygen vacancy which is confirmed by the XPS analysis. According to the obtained results, one can say that this novel synthetic recipe increased the solubility of Mn ions into the CeO{sub 2} crystal structure and improved the magnetization by more than 37 times compared to the Mn doped CeO{sub 2} prepared by conventional methods. - Highlights: • Mn doped ceria was prepared by HMTD assisted solvothermal technique. • Complete solubility of Mn atoms in the ceria structure was achieved up to 10 at%. • High saturation magnetization of 4.48 emu/g was achieved at 8 at%. • The magnetization was improved by more than 37 times compared to conventional methods.


    Sub-slab sampling has become an integral part of vapor intrusion investigations. It is now recommended in guidance documents developed by EPA and most states. A method for sub-slab probe installation was devised in 2002, presented at conferences through 2005, and finally docume...

  18. 19 CFR 351.521 - Import substitution subsidies. [Reserved (United States)


    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Import substitution subsidies. 351.521 Section 351... COUNTERVAILING DUTIES Identification and Measurement of Countervailable Subsidies § 351.521 Import substitution subsidies. ...

  19. Reductive Heck Reactions of N-Methyl-substituted Tricyclic Imides


    Gokce Goksu; Nuket Ocal; Dieter E. Kaufmann


    The palladium-catalyzed hydroarylation of N-methyl-substituted tricyclic imides was studied in order to find a new stereoselective access to a series of new exo-aryl(hetaryl)-substituted tricyclic N-methylimides.

  20. An Exploration of Substitutes for Leadership: Problems and Prospects

    National Research Council Canada - National Science Library

    Wu, Yu-Chi


    Despite the conceptual premise of Kerr and Jermier's (1978) substitutes for leadership model, there has been little evidence of empirical support when substitutes for leadership are modeled as interactions with leader behaviors...

  1. The Synthesis of Substituted Piperazine-cholesterol Conjugates for ...

    African Journals Online (AJOL)


    , a set of cholesteryl derivatives, containing piperazines substituted with additional aromatic groups, were synthesized. (Table 2). These included the pyridine substituted piperazines. (6k) and (6l), as well as the 2-pyrimidine (6m). Of note is that.


    The study evaluated the zinc chloride electroplating process as a substitute for cadmium cyanide electroplating in the manufacture of industrial connectors and fittings at Aeroquip Corporation. The process substitution eliminates certain wastes, specifically cadmium and cyanide, ...

  3. Influence of hybridization in the magnetic circular X-ray dichroism at the Ce-M(4,5) absorption edges of Ce-Fe systems

    NARCIS (Netherlands)

    Finazzi, M; deGroot, FMF; Dias, AM; Kappler, JP; Schulte, O; Felsch, W; Krill, G

    We have performed a Magnetic Circular X-ray Dichroism (XMCD) study at the Ce-M(4,5) absorption edges on some Ce-Fe systems. We find that the dichroism signal in these systems is very sensitive to the degree of hybridization of the 4f electrons with the valence band. XMCD is able to demonstrate that

  4. Photocatalytic degradation of methyl orange by CeO2 and Fe-doped CeO2 films under visible light irradiation

    National Research Council Canada - National Science Library

    Channei, D; Inceesungvorn, B; Wetchakun, N; Ukritnukun, S; Nattestad, A; Chen, J; Phanichphant, S


    Undoped CeO2 and 0.50-5.00 mol% Fe-doped CeO2 nanoparticles were prepared by a homogeneous precipitation combined with homogeneous/impreganation method, and applied as photocatalyst films prepared by a doctor blade technique...

  5. Total Oxidation of Propane Using CeO2 and CuO-CeO2 Catalysts Prepared Using Templates of Different Nature

    National Research Council Canada - National Science Library

    Benjamin Solsona; Rut Sanchis; Ana M Dejoz; Tomas García; Lidia Ruiz-Rodríguez; Jose Manuel López Nieto; Juan Antonio Cecilia; Enrique Rodríguez-Castellón


    Several CeO2 and CuO-CeO2 catalysts were prepared using different methods, i.e., a homogeneous precipitation with urea, a nanocasting route using CMK-3 carbon as a hard template and a sol-gel process using Poly(methyl methacrylate) (PMMA...

  6. Glass forming ability of the Al-Ce-Ni system; Avaliacao da capacidade de formacao vitrea do sistema Al-Ce-Ni

    Energy Technology Data Exchange (ETDEWEB)

    Triveno Rios, C. [Engenharia Mecanica, Universidade Federal de Mato Grosso, Rondonopolis, MT (Brazil)], e-mail:; Surinach, S.; Baro, M.D. [Departamento de Engenharia de Materiais - Universidade Federal de Sao Carlos, SP (Brazil); Bolfarini, C.; Botta, W.J.; Kiminami, C.S. [Departamento de Fisica da Universidade Autonoma de Barcelona, Bellaterra (Spain)


    In the present work, the glass forming ability (GFA) and its compositional dependence on Al-Ni-Ce system alloys were investigated in function of several thermal parameters. Rapidly quenched Al{sub 85}Ni{sub 15}-{sub X}Ce{sub X} (X=4,5,6,7,10), Al{sub 90}Ni{sub 5}Ce{sub 5}, Al{sub 89}Ni{sub 2}.{sub 4}Ce{sub 8}.{sub 6}, Al{sub 80}Ni{sub 15.6}Ce{sub 4}.{sub 4} and Al{sub 78}Ni{sub 18.5}Ce{sub 3.5} amorphous ribbons were produced by melt-spinning and the structural transformation during heating was studied using a combination of X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The results showed that the GFA and the thermal stability in the Al-rich corner of Al- Ni-Ce system alloys were enhanced by increasing the solute content and specifically the Ce content (author)

  7. Abnormal variation of magnetic properties with Ce content in (PrNdCe)2Fe14B sintered magnets prepared by dual alloy method (United States)

    Xue-Feng, Zhang; Jian-Ting, Lan; Zhu-Bai, Li; Yan-Li, Liu; Le-Le, Zhang; Yong-Feng, Li; Qian, Zhao


    Resource-saving (PrNdCe)2Fe14B sintered magnets with nominal composition (PrNd)15-x Ce x Fe77B8 (x = 0-10) were prepared using a dual alloy method by mixing (PrNd)5Ce10Fe77B8 with (PrNd)15Fe77B8 powders. For Ce atomic percent of 1% and 2%, coercivity decreases dramatically. With further increase of Ce atomic percent, the coercivity increases, peaks at 6.38 kOe in (PrNd)11Ce4Fe77B8, and then declines gradually. The abnormal dependence of coercivity is likely related to the inhomogeneity of rare earth chemical composition in the intergranular phase, where PrNd concentration is strongly dependent on the additive amount of (PrNd)5Ce10Fe77B8 powders. In addition, for Ce atomic percent of 8%, 7%, and 6% the coercivity is higher than that of magnets prepared by the conventional method, which shows the advantage of the dual alloy method in preparing high abundant rare earth magnets. Project supported by the National Natural Science Foundation of China (Grant Nos. 51461033, 51571126, 51541105, and 11547032), the Natural Science Foundation of Inner Mongolia, China (Grant No. 2013MS0110), and the Inner Mongolia University of Science and Technology Innovation Fund, China.

  8. Preparation for CeO2/Nanographite Composite Materials and Electrochemical Degradation of Phenol by CeO2/Nanographite Cathodes. (United States)

    Yu, Li; Yu, Xiujuan; Sun, Tianyi; Wang, Na


    CeO2/nanographite (CeO2/nano-G) composite materials were got by chemical precipitation method with nanographite (nano-G) and cerous nitrate hexahydrate as raw materials. The microstructures of CeO2/nano-G composite materials were characterized by means of SEM, XRD, XPS and Raman. The cathodes were made by nano-G and CeO2/nano-G composite materials, respectively. The electrolysis phenol was conducted by the diaphragm cell prepared cathode and the Ti/RuO2 anode. The results indicated that the Cerium oxide is mainly in nanoscale spherical state, uniformly dispersed in the nanographite sheet surface, and there are two different oxidation states for elemental Ce, namely, Ce(III) and Ce(IV). In the diaphragm electrolysis system with the aeration conditions, the degradation rate of phenol reached 93.9% under 120 min's electrolysis. Ceria in the cathode materials might lead to an increase in the local oxygen concentration, which accelerated the two-electron reduction of O2 to hydrogen peroxide (H2O2). The removal efficiency of phenol by using the CeO2/nano-G composite cathode was better than that of the nano-G cathode.

  9. Effects of Ce3+ concentration, beam voltage and current on the cathodoluminescence intensity of SiO2: Pr3+–Ce3+ nanophosphor

    CSIR Research Space (South Africa)

    Mhlongo, GH


    Full Text Available SiO2:Pr3+–Ce3+ phosphor powders were successfully prepared using a sol–gel process. The concentration of Pr3+ was fixed at 0.2 mol% while that of Ce3+ was varied in the range of 0.2–2 mol%. High resolution transmission electron microscopy (HRTEM...

  10. Nonproportional response of LaBr3:Ce and LaCl3:Ce scintillators to synchrotron x-ray irradiation

    NARCIS (Netherlands)

    Khodyuk, I.V.; Dorenbos, P.


    The nonproportional scintillation response of LaBr3 doped with 5% Ce3+ and of LaCl3 doped with 10% Ce3+ was measured using highly monochromatic synchrotron irradiation. To estimate the photon response, pulse height spectra at many finely spaced energy values between 9 and 100 keV were measured. The

  11. Influence of hybridization in the Magnetic Circular X-ray Dichroism at the Ce-M4,5 absorption edges of Ce-Fe systems

    NARCIS (Netherlands)

    Finazzi, M.; de Groot, F.M.F.; Dias, A.-M.; Kappler, J.-P.; Schulte, O.; Felsch, W.; Krill, G.


    We have performed a Magnetic Circular X-ray Dichroism (XMCD) study at the Ce-M*,s absorption edges on some Ce-Fe systems. We find that the dichroism signal in these systems is very sensitive to the degree of hybridization of the 4f electrons with the valence band. XMCD is able to demonstrate that

  12. High pressure optical combustion probe

    Energy Technology Data Exchange (ETDEWEB)

    Woodruff, S.D.; Richards, G.A.


    The Department of Energy`s Morgantown Energy Technology Center has developed a combustion probe for monitoring flame presence and heat release. The technology involved is a compact optical detector of the OH radical`s UV fluorescence. The OH Monitor/Probe is designed to determine the flame presence and provide a qualitative signal proportional to the flame intensity. The probe can be adjusted to monitor a specific volume in the combustion zone to track spatial fluctuations in the flame. The probe is capable of nanosecond time response and is usually slowed electronically to fit the flame characteristics. The probe is a sapphire rod in a stainless steel tube which may be inserted into the combustion chamber and pointed at the flame zone. The end of the sapphire rod is retracted into the SS tube to define a narrow optical collection cone. The collection cone may be adjusted to fit the experiment. The fluorescence signal is collected by the sapphire rod and transmitted through a UV transmitting, fused silica, fiber optic to the detector assembly. The detector is a side window photomultiplier (PMT) with a 310 run line filter. A Hamamatsu photomultiplier base combined with a integral high voltage power supply permits this to be a low voltage device. Electronic connections include: a power lead from a modular DC power supply for 15 VDC; a control lead for 0-1 volts to control the high voltage level (and therefore gain); and a lead out for the actual signal. All low voltage connections make this a safe and easy to use device while still delivering the sensitivity required.

  13. Changes in magnetic properties of Ce/sub x/La/sub 1-x/Cu/sub 2/Si/sub 2/ series during the transition from a Kondo impurity to a Kondo lattice

    Energy Technology Data Exchange (ETDEWEB)

    Aliev, F.G.; Brandt, N.B.; Moshchalkov, V.V.; Lutsiv, R.V.; Chudinov, S.M.


    Magnetic properties of isostructural substitutional solid solutions Ce/sub x/La/sub 1-x/Cu/sub 2/Si/sub 2/ (0Ce/sub x/La/sub 1-x/Cu/sub 2/Si/sub 2/ into a spin glass. It has been found that temperature T/sub SG/ initially (0.2< or =x< or =0.6) increases from 0.3 K to 1.6 K, and then in the region x> or approx. =0.8, the value of T/sub SG/ decreases, and near xroughly-equal1 Ce/sub x/La/sub 1-x/Cu/sub 2/Si/sub 2/ compounds become superconducting. These changes in magnetic properties of Ce/sub x/La/sub 1-x/Cu/sub 2/Si/sub 2/ take place during the transition from a Kondo impurity (x< or =1) to a Kondo lattice (xroughly-equal1) when there appears a narrow resonance near the Fermi energy for x..-->..1, which causes a decrease of the effective magnetic moment of Ce ions (and a decrease of T/sub SG/ in the region x> or approx. =0.8) and appearance of superconductivity of heavy fermions in CeCu/sub 2/Si/sub 2/.

  14. [Interaction of surface active fluorescence probes and bovine serum albumin]. (United States)

    Xu, Tong-kuan; Li, Na; Shen, Xing-hai; Gao, Hong-cheng


    The binding between two surface-active substituted 3H-indole fluorescence probes, i. e., iodo-dihexadecyl methyl-2-(p-dodecyl amino phenyl)-3, 3-dimethyl-5-carboethoxy-3H-indole ammonium and iodo-dimethyloctadecyl-2-(p-dodecyl amino phenyl)-3,3-dimethyl-5-carboethoxy-3H-indole ammonium, and bovine serum albumin (BSA) in aqueous solution was studied using fluorescence. The binding constant and binding site number of molecule 1 and molecule 2 with BSA were obtained. It was confirmed that electrostatic interaction is the primary driving force for the combination of BSA with molecule 1 or molecule 2. According to the Förster resonance energy transfer theory, the distances between molecule 1, molecule 2 and tryptophan of BSA were calculated to be 2.90 nm and 4.02 nm, respectively.

  15. A highly selective and ratiometric fluorescent probe for cyanide by rationally altering the susceptible H-atom. (United States)

    Hao, Yuanqiang; Nguyen, Khac Hong; Zhang, Yintang; Zhang, Guan; Fan, Shengnan; Li, Fen; Guo, Chao; Lu, Yuanyuan; Song, Xiaoqing; Qu, Peng; Liu, You-Nian; Xu, Maotian


    A highly selective and ratiometric fluorescent probe for cyanide was rationally designed and synthesized. The probe comprises a fluorophore unit of naphthalimide and a CN- acceptor of methylated trifluoroacetamide group. For these previous reported trifluoroacetamide derivative-based cyanide chemosensors, the H-atom of amide adjacent to trifluoroacetyl group is susceptible to be attacked by various anions (CN- itself, F-, AcO-, et al.) and even the solvent molecule, which resulted in the bewildered reaction mechanism and poor selectivity of the assay. In this work, the susceptible H-atom of trifluoroacetamide was artfully substituted by alkyl group. Thus a highly specific fluorescent probe was developed for cyanide sensing. Upon the nucleophilic addition of cyanide anion to the carbonyl of trifluoroacetamide moiety of the probe, the ICT process of the probe was significantly enhanced and leading to a remarkable red shift in both absorption and emission spectra of the probe. This fluorescent assay showed a linear range of 1.0-80.0µM and a LOD (limit of detection) of 0.23µM. All the investigated interference have no influence on the sensing behavior of the probe toward cyanide. Moreover, by coating on TLC plate, the probe can be utilized for practical detection of trace cyanide in water samples. Copyright © 2017. Published by Elsevier B.V.

  16. Interinstrumental transfer of a fast short-end injection capillary electrophoresis method: Application to the separation of niobium, tantalum, and their substituted ions. (United States)

    De Cock, Bart; Oliver, James D; Delaunay, Nathalie; Deblonde, Gauthier; Mangelings, Debby; Vander Heyden, Yvan


    The interinstrumental transfer of a short-end CE method was studied. A model separation of the hexameric forms of niobium, tantalum, and their substituted ions (Nb6-x Tax with 0 ≤ x ≤ 6) was selected as test case. The method was first optimized on a Beckman instrument and in a second step transferred to an Agilent instrument. The transfer needed updated guidelines that tackled differences in effective capillary length, 8.5 (Agilent) versus 10 cm (Beckman), because of instrumental different capillary cartridges. Differences in effective length lead to migration time and separation efficiency inequalities, illustrated by a decrease in resolution between the substituted ions. The difference in effective length was overcome by adapting the lift offset parameter of the Agilent instrument. The lift offset default setting is 4 mm and by increasing this parameter both the inlet and outlet lifts are lowered and thus the detection window can be displaced and consequently the effective length was increased. The decrease in effective length difference and the effect on the separation efficiency was investigated and led finally to a restored separation of the substituted ions. The adaptation of the lift offset parameter during short-end injection methods was added to earlier developed guidelines to facilitate interinstrumental method transfer of CE methods. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. A-Site (MCe) Substitution Effects on the Structures and Properties of CaBi4Ti4O15 Ceramics (United States)

    Yan, Haixue; Li, Chengen; Zhou, Jiaguang; Zhu, Weimin; He, Lianxin; Song, Yuxin


    We investigated the effect of A-site compound substitution on the structures and properties of Ca0.8(MCe)0.1Bi4Ti4O15 (M denotes Li, Na and K) ceramics. The samples were prepared by the conventional ceramic technique. Sintering characteristics of Ca0.8(MCe)0.1Bi4Ti4O15 and CaBi4Ti4O15 ceramics were discussed. X-ray powder diffraction patterns of the three modified CBT-based compounds show a single phase of bismuth oxide layer type structure with m=4. The hysteresis loops of polarization versus electric field of the four compounds were also measured. A-site compound substitution improves the piezoelectric properties and the high-temperature resistivity of these materials. A-site (LiCe) and (KCe) substitution not only improves the Curie temperature but also decreases the temperature coefficient of dielectric constant (TK\\varepsilon). Among the three modified ceramics, only the Curie temperature of Ca0.8(NaCe)0.1Bi4Ti4O15 is lower than that of CaBi4Ti4O15; however, its TK\\varepsilon is the lowest. As a result, all the three modified CBT-based ceramics were found to be excellent high-temperature piezoelectric materials.

  18. Preparation and characterization of selenite substituted hydroxyapatite

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jun; Wang, Yanhua; Zhou, Lei [Advance Biomaterials and Tissue Engineering Center, Huazhong University of Science and Technology, Wuhan 430074 (China); Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhang, Shengmin, E-mail: [Advance Biomaterials and Tissue Engineering Center, Huazhong University of Science and Technology, Wuhan 430074 (China); Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); China-Korea Center for Biomaterials and Nano-biotechnology, Life Science Building, 1037 Luoyu Road, Wuhan 430074 (China)


    Selenite-substituted hydroxyapatite (Se-HA) with different Se/P ratios was synthesized by a co-precipitation method, using sodium selenite (Na{sub 2}SeO{sub 3}) as a Se source. Selenium has been incorporated into the hydroxyapatite lattice by partially replacing phosphate (PO{sub 4}{sup 3-}) groups with selenite (SeO{sub 3}{sup 2-}) groups. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) techniques reveal that substitutions of phosphate groups by selenite groups cause lower carbonate groups occupying at phosphate sites and change the lattice parameters of hydroxyapatite. The powders obtained are nano-crystalline hydroxyapatite when the Se/P ratios are not more than 0.1. The particle shape of Se-HA has not been altered compared with selenite-free hydroxyapatite but Se-incorporation reduces the crystallite size. The crystallinity was reduced as the Se/P ratios increased until amorphous phase (Se/P = 0.3) appeared in the Se-HA powder obtained, and then another crystal phase presented as calcium selenite hydrate (Se/P = 10). In addition, the sintering tests show that the Se-HA powders with the Se/P ratio of 0.1 have thermal stability at 900 Degree-Sign C for 2 h; hence they have great potential in the fabrication of bone repair scaffolds. - Highlights: Black-Right-Pointing-Pointer We investigate the Se/P ratio for the synthesis of selenium substituted HA. Black-Right-Pointing-Pointer Nano-crystalline HA structure is remained when Se/P ratio is below 0.1. Black-Right-Pointing-Pointer Calcium selenite hydrate forms when Se/P ratio is beyond 10. Black-Right-Pointing-Pointer Selenite substituted HA powders (Se/P < 0.1) are stable at 900 Degree-Sign C for 2 h.

  19. Synthesis of 2-azetidinones substituted quinoline derivative

    Directory of Open Access Journals (Sweden)

    Mashelkar Uday C.


    Full Text Available Acetanilide is converted into 2-chloro-3-formyl quinoline by reacting with DMF-POCl3 at 80-90ºC and then condensed with aromatic primary amines to give Schiff bases (3a-3c. These Schiff bases are then reacted with acid chlorides in the presence of base in toluene to give 1, 3, 4-substituted 2-azetidinones.



    Saroj; Hemina; Praveg


    : BACKGROUND: In the developing countries manual methods are still used for the cultivation of the bacteria and many a times difficulties are involved in procuring suitable components for preparation of various nutrient media. The need has therefore arisen, to investigate the problem of exploitation of indigenous material such as groundnuts to substitute commercial preparations used in the various nutrient media for bacteriological culture. AIMS & OBJECTIVES: In the presen...