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Sample records for bi cd cs

  1. Physical properties of Bi doped CdTe thin films grown by CSVT and their influence on the CdS/CdTe solar cells PV-properties

    International Nuclear Information System (INIS)

    Vigil-Galan, O.; Sanchez-Meza, E.; Ruiz, C.M.; Sastre-Hernandez, J.; Morales-Acevedo, A.; Cruz-Gandarilla, F.; Aguilar-Hernandez, J.; Saucedo, E.; Contreras-Puente, G.; Bermudez, V.

    2007-01-01

    The physical properties of Bi doped CdTe films, grown on glass substrates by the Closed Space Transport Vapour (CSVT) method, from different Bi doped CdTe powders are presented. The CdTe:Bi films were characterized using Photoluminescence, Hall effect, X-Ray diffraction, SEM and Photoconductivity measurements. Moreover, CdS/CdTe:Bi solar cells were made and their characteristics like short circuit current density (J sc ), open circuit voltage (V OC ), fill factor (FF) and efficiency (η) were determined. These devices were fabricated from Bi doped CdTe layers deposited on CdS with the same growth conditions than those used for the single CdTe:Bi layers. A correlation between the CdS/CdTe:Bi solar cell characteristics and the physical properties of the Bi doped CdTe thin films are presented and discussed

  2. Synthesis, structural and spectroscopic properties of acentric triple molybdate Cs{sub 2}NaBi(MoO{sub 4}){sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Savina, A.A. [Laboratory of Oxide Systems, Baikal Institute of Nature Management, SB RAS, Ulan-Ude 670047 (Russian Federation); Department of Chemistry, Buryat State University, Ulan-Ude 670000 (Russian Federation); Atuchin, V.V., E-mail: atuchin@isp.nsc.ru [Laboratory of Optical Materials and Structures, Rzhanov Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090 (Russian Federation); Functional Electronics Laboratory, Tomsk State University, Tomsk 634050 (Russian Federation); Laboratory of Semiconductor and Dielectric Materials, Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Solodovnikov, S.F. [Laboratory of Crystal Chemistry, Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Solodovnikova, Z.A. [Laboratory of Crystal Chemistry, Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Krylov, A.S. [Laboratory of Molecular Spectroscopy, Kirensky Institute of Physics, SB RAS, Krasnoyarsk 660036 (Russian Federation); Maximovskiy, E.A. [Laboratory of Epitaxial Layers, Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Laboratory of Research Methods of Composition and Structure of Functional Materials, Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Molokeev, M.S. [Laboratory of Crystal Structure, Kirensky Institute of Physics, SB RAS, Krasnoyarsk 660036 (Russian Federation); Oreshonkov, A.S [Laboratory of Molecular Spectroscopy, Kirensky Institute of Physics, SB RAS, Krasnoyarsk 660036 (Russian Federation); Department of Photonics and Laser Technology, Siberian Federal University, Krasnoyarsk 660079 (Russian Federation); Pugachev, A.M. [Laboratory of Condenced Matter Spectroscopy, Institute of Automation and Electrometry, SB RAS, Novosibirsk 90, 630090 (Russian Federation); and others

    2015-05-15

    New ternary molybdate Cs{sub 2}NaBi(MoO{sub 4}){sub 3} is synthesized in the system Na{sub 2}MoO{sub 4}–Cs{sub 2}MoO{sub 4}–Bi{sub 2}(MoO{sub 4}){sub 3}. The structure of Cs{sub 2}NaBi(MoO{sub 4}){sub 3} of a new type is determined in noncentrosymmetric space group R3c, a=10.6435(2), c=40.9524(7) Å, V=4017.71(13) Å{sup 3}, Z=12 in anisotropic approximation for all atoms taking into account racemic twinning. The structure is completely ordered, Mo atoms are tetrahedrally coordinated, Bi(1) and Bi(2) atoms are in octahedra, and Na(1) and Na(2) atoms have a distorted trigonal prismatic coordination. The Cs(1) and Cs(2) atoms are in the framework cavities with coordination numbers 12 and 10, respectively. No phase transitions were found in Cs{sub 2}NaBi(MoO{sub 4}){sub 3} up to the melting point at 826 K. The compound shows an SHG signal, I{sub 2w}/I{sub 2w}(SiO{sub 2})=5 estimated by the powder method. The vibrational properties are evaluated by Raman spectroscopy, and 26 narrow lines are measured. - Graphical abstract: - Highlights: • The crystal structure of Cs{sub 2}NaBi(MoO{sub 4}){sub 3} is defined. • The molybdate Cs{sub 2}NaBi(MoO{sub 4}){sub 3} is stable up to melting point at 826 K. • Vibrational properties of Cs{sub 2}NaBi(MoO{sub 4}){sub 3} are evaluated by Raman spectroscopy.

  3. Limitations of Cs3Bi2I9 as lead-free photovoltaic absorber materials.

    Science.gov (United States)

    Ghosh, Biplab; Wu, Bo; Mulmudi, Hemant Kumar; Guet, Claude; Weber, Klaus; Sum, Tze Chien; Mhaisalkar, Subodh G; Mathews, Nripan

    2018-01-17

    Lead (Pb) halide perovskites have attracted tremendous attention in recent years due to their rich optoelectronic properties, which have resulted in more than 22% power conversion efficient photovoltaics. Nevertheless, Pb-metal toxicity remains a huge hurdle for extensive applications of these compounds. Thus, alternative compounds with similar optoelectronic properties need to be developed. Bismuth possesses similar electronic structure as that of lead with the presence of ns2 electrons that exhibit rich structural variety as well as interesting optical and electronic properties. Herein, we critically assess Cs3Bi2I9 as a candidate for thin-film solar cell absorber. Despite a reasonable optical bandgap (~2eV) and absorption coefficient, the power conversion efficiency of the Cs3Bi2I9 mesoscopic solar cells was found to be severely lacking, limited by poor photocurrent density. The efficiency of the Cs3Bi2I9 solar cell can be slightly improved by changing the stoichiometry of the precursor solutions. We have investigated the possible reasons behind the poor performance of Cs3Bi2I9 by transient absorption and luminescence spectroscopy. Comparison between thin-films and single crystals highlights the presence of intrinsic defects in thin-films which act as nonradiative recombination centers.

  4. The sorption behavior of Cs and Cd onto oxide and clay surfaces

    International Nuclear Information System (INIS)

    Westrich, H.R.; Cygan, R.T.; Brady, P.V.; Nagy, K.L.; Anderson, H.L.; Kirkpatrick, R.J.

    1995-01-01

    The sorption of Cs and Cd on model soil minerals was examined by complementary analytical and experimental procedures. X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonance (NMR) spectroscopy were used to characterize the chemical and physical nature of Cs-reacted soil minerals. Cd and Cs adsorption isotherms for kaolinite were also measured at variable pH and temperature to establish likely reaction stoichiometries, while atomic force microscopy (AFM) was used to characterize the microtopography of the clay surface. XPS analyses of Cs-exchanged samples show that Cs is sorbed at mineral surfaces and at the interlayer site of smectite clays, although the spectral resolution of XPS analyses is insufficient to differentiate between basal, edge or interlayer sites. 133 Cs MAS-NMR results also show that Cs is adsorbed primarily in an interlayer site of montmorillonite and on edge and basal sites for kaolinite. Cd adsorption isotherms on kaolinite were found to be additive using Al 2 0 3 + Si0 2 Cd binding constants. AFM quantification of kaolinite crystallites suggest that edges comprise up to 50% of the BET surface area, and are consistent with NMR and surface charge results that Cs an Cd adsorption occur primarily at edge sites

  5. CD16xCD33 bispecific killer cell engager (BiKE) activates NK cells against primary MDS and MDSC CD33+ targets.

    Science.gov (United States)

    Gleason, Michelle K; Ross, Julie A; Warlick, Erica D; Lund, Troy C; Verneris, Michael R; Wiernik, Andres; Spellman, Stephen; Haagenson, Michael D; Lenvik, Alexander J; Litzow, Mark R; Epling-Burnette, Pearlie K; Blazar, Bruce R; Weiner, Louis M; Weisdorf, Daniel J; Vallera, Daniel A; Miller, Jeffrey S

    2014-05-08

    Myelodysplastic syndromes (MDS) are stem cell disorders that can progress to acute myeloid leukemia. Although hematopoietic cell transplantation can be curative, additional therapies are needed for a disease that disproportionally afflicts the elderly. We tested the ability of a CD16xCD33 BiKE to induce natural killer (NK) cell function in 67 MDS patients. Compared with age-matched normal controls, CD7(+) lymphocytes, NK cells, and CD16 expression were markedly decreased in MDS patients. Despite this, reverse antibody-dependent cell-mediated cytotoxicity assays showed potent degranulation and cytokine production when resting MDS-NK cells were triggered with an agonistic CD16 monoclonal antibody. Blood and marrow MDS-NK cells treated with bispecific killer cell engager (BiKE) significantly enhanced degranulation and tumor necrosis factor-α and interferon-γ production against HL-60 and endogenous CD33(+) MDS targets. MDS patients had a significantly increased proportion of immunosuppressive CD33(+) myeloid-derived suppressor cells (MDSCs) that negatively correlated with MDS lymphocyte populations and CD16 loss on NK cells. Treatment with the CD16xCD33 BiKE successfully reversed MDSC immunosuppression of NK cells and induced MDSC target cell lysis. Lastly, the BiKE induced optimal MDS-NK cell function irrespective of disease stage. Our data suggest that the CD16xCD33 BiKE functions against both CD33(+) MDS and MDSC targets and may be therapeutically beneficial for MDS patients.

  6. Energy- and temperature dependences of secondary electron emission of CsI- and CsBr layers doped with Cd

    International Nuclear Information System (INIS)

    Galij, P.V.; Tsal', N.A.

    1983-01-01

    The energy and temperature dependences of the secondary electron emission coefficient (SEEC) of CsI-Cd-, CsBr-Cd-, CsI-CsBr layers have been studied. The effect of bivalent cadmium impurity on the SEEC value is investigated. It is shown that implantation of small amounts of Cd 2+ impurity into the lattice of the initial monocrystals might increase the SEEC values of the layers. Temperature dependences (TD) of SEEC are measured and the possibility of comparing experimental results with the Dekker formula is analyzed. A conclusion is drawn that the Dekker model well describes the TD of SEEC of doped layers at temperatures T < or approximately 100 deg C. At elevated temperatures., along with secondary electron scattering on phonons, one should take into account their scattering on vacancies

  7. Band Structure Engineering of Cs2AgBiBr6 Perovskite through Order-Disordered Transition: A First-Principle Study.

    Science.gov (United States)

    Yang, Jingxiu; Zhang, Peng; Wei, Su-Huai

    2018-01-04

    Cs 2 AgBiBr 6 was proposed as one of the inorganic, stable, and nontoxic replacements of the methylammonium lead halides (CH 3 NH 3 PbI 3 , which is currently considered as one of the most promising light-harvesting material for solar cells). However, the wide indirect band gap of Cs 2 AgBiBr 6 suggests that its application in photovoltaics is limited. Using the first-principle calculation, we show that by controlling the ordering parameter at the mixed sublattice, the band gap of Cs 2 AgBiBr 6 can vary continuously from a wide indirect band gap of 1.93 eV for the fully ordered double-perovskite structure to a small pseudodirect band gap of 0.44 eV for the fully random alloy. Therefore, one can achieve better light absorption simply by controlling the growth temperature and thus the ordering parameters and band gaps. We also show that controlled doping in Cs 2 AgBiBr 6 can change the energy difference between ordered and disordered Cs 2 AgBiBr 6 , thus providing further control of the ordering parameters and the band gaps. Our study, therefore, provides a novel approach to carry out band structure engineering in the mixed perovskites for optoelectronic applications.

  8. Systems of Rb2I2-CdI2-PbI2 and Cs2I2-CdI2-PbI2

    International Nuclear Information System (INIS)

    Volchanskaya, V.V.; Il'yasov, I.I.

    1979-01-01

    The Rb 2 I 2 -CdI 2 -PbI 2 and Cs 2 I 2 -CdI 2 -PbI 2 triple systems have been studied, using the visual-polythermal method. The liquidus of the systems researched consists of the components and compounds crystallization fields: 2RbIxCdI 2 , 2RbIxRbI 2 , RbIxPbI 2 and 2CsIxCdI 2 , 4CsIxPbI 2 , CsIxPbI 2 , respectively. The crystallization fields converge in four non-variant points at 360, 280, 205 and 192 deg C in the Rb 2 I 2 -CdI 2 -PbI 2 system and at 375, 368, 208 and 190 deg C in the CsI 2 -CdI 2 -PbI 2 system

  9. Experimental studies on the biokinetics of Cs-134 and Cd-109 in the blood cockle (Anadara granosa)

    International Nuclear Information System (INIS)

    Norfaizal Mohamed; Nita Salina Abu Bakar; Zal Uyun Wan Mahmood; Nur Hidaya Dmuliany Mohd Sidek; Zaharudin Ahmad

    2010-01-01

    Bioaccumulation and depuration study under controlled laboratory conditions of Cs and Cd in Anadara granosa collected at coastal Kapar, Selangor was carried out using respective radiotracer, Cs-134 and Cd-109. The radioactivity of Cs-134 and Cd-109 were determined using high resolution hyper germanium detector. Our results demonstrate that Cd-109 was accumulated efficiently by this species, except Cs-134. The steady state concentration factor (CF) for accumulation of Cs-134 and Cd-109 from seawater was estimated to be about 5.86 and 51.31, respectively. For the depuration stage, loss kinetics of Cs-134 and Cd-109 was best described by 2-compartment exponential model. Results shown that A. granosa exposed to Cs-134 have a total loss of 69% in compared to 19 % of Cd-109. Results gained in this experiment are a baseline data to evaluate future released of radioactive material from nuclear power programme facilities within this region. (author)

  10. Site selective excitation spectroscopy of CsCdBr sub 3 :U sup 3 sup +

    CERN Document Server

    Yin Min

    2002-01-01

    The CsCdBr sub 3 :U sup 3 sup + crystal was grown by the Bridgman technique from the starting materials CsBr, CdBr sub 2 and UBr sub 4. X-ray check showed that the sample crystallized in the CsNiBr sub 3 structure. Under selective excitation at low temperature, the emission spectra and the fluorescence decay curve were measured and discussed

  11. A theoretical study of perovskite CsXCl3 (X=Pb, Cd) within first principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Ilyas, Bahaa M., E-mail: bahaastring@gmail.com [Department of Physics, University Of Dohuk (Iraq); Elias, Badal H. [Laboratory of Theoretical Physics, Department of Physics, Faculty of Sciences, University of Dohuk (Iraq)

    2017-04-01

    The structural, elastic, electronic, optical acoustic and thermodynamic properties of the cubic perovskite CsPbCl{sub 3} and CsCdCl{sub 3} unit cell, were studied using an ultra-soft pseudopotential plane wave, the Trouiller-Martins-Functional was utilized to perform these calculations. The study was implemented within both the Local Density Approximation (LDA) and the Generalized Gradient Approximation (GGA). the Generalized Gradient Approximation (GGA) scheme proposed by van Leeuwen-Baerends which is the same as the Perdew-Wang 92 functional have been carried out to preform our calculations. As for the Local Density Approximation (LDA) the Teter-Pade parametrization (4/93) was implemented which is the same as Perdew-Wang that in its turn reproduces the Ceperley-Alder-Functional. The computed GGA/LDA-lattice parameter for both CsCdCl{sub 3} and CsPbCl{sub 3} is in an exquisite agreement with the experimental and theoretical results. The energy band structure shows that CsCdCl{sub 3} is Γ–R indirect band gap insulator, while CsPbCl{sub 3} is an insulator with a direct band gap Γ–Γ separating the valence bands from the conduction bands, which shows metallic nature after pressure 30 GPa. A hybridization exists between Pb-p states and Cl-p states for CsPbCl{sub 3}, and Cd-p states and Cs-p states for the CsCdCl{sub 3} in the valence bonding region. Optimization of both cell shape (geometry) volume were investigated as pressure of 0–20 GPa and 0–40 GPa for the CsCdCl{sub 3} and CsPbCl{sub 3} respectively. The Pressure dependence of cubic perovskite elastic constants, Young modulus, bulk and shear moduli, Lame’s constants, elastic anisotropy factor, elastic wave velocities, phonon dispersion, Debye temperature and the density of states of CsXCl{sub 3} (X=Pb, Cd) were theoretically calculated and compared with the other available theoretical results. The above elastic constants reveal the fact that both compounds are stable and show nature of ductility. For

  12. Structure of Z-scheme CdS/CQDs/BiOCl heterojunction with enhanced photocatalytic activity for environmental pollutant elimination

    Science.gov (United States)

    Pan, Jinbo; Liu, Jianjun; Zuo, Shengli; Khan, Usman Ali; Yu, Yingchun; Li, Baoshan

    2018-06-01

    Z-scheme CdS/CQDs/BiOCl heterojunction was synthesized by a facile region-selective deposition process. Owing to the electronegativity of the groups on the surface of Carbon Quantum Dots (CQDs), they can be sandwiched between CdS and BiOCl, based on the stepwise region-selective deposition process. The samples were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution TEM (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), photoelectrochemical measurements and photoluminescence (PL). The results indicate that CQDs with size of 2-5 nm and CdS nanoparticles with size of 5-10 nm dispersed uniformly on the surface of cuboid BiOCl nanosheets. The photocatalytic performance tests reveal that the CdS/CQDs/BiOCl heterojunction exhibits much higher photocatalytic activity than that of BiOCl, CdS/BiOCl and CQDs/BiOCl for Rhodamine B (RhB) and phenol photodegradation under visible and UV light illumination, respectively. The enhanced photocatalytic performance should be attributed to the Z-scheme structure of CdS/CQDs/BiOCl, which not only improves visible light absorption and the migration efficiency of the photogenerated electron-holes but also keeps high redox ability of CdS/CQDs/BiOCl composite.

  13. Modification of photosensing property of CdS–Bi{sub 2}S{sub 3} bi-layer by thermal annealing and swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shaikh, Shaheed U.; Siddiqui, Farha Y. [Thin Film and Nanotechnology Laboratory, Department of Physics (India); Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004 (India); Singh, Fouran; Kulriya, Pawan K. [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Phase, D.M. [UGC DAE Consortium for Scientific Research, Khandwa Road, Indore 452017 (India); Sharma, Ramphal, E-mail: ramphalsharma@yahoo.com [Thin Film and Nanotechnology Laboratory, Department of Physics (India); Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004 (India)

    2016-02-01

    The CdS–Bi{sub 2}S{sub 3} bi-layer thin films have been deposited on Indium Tin Oxide (ITO) glass substrates at room temperature by Chemical Bath Deposition Technique (CBD) and bi-layer thin films were annealed in air atmosphere for 1 h at 250 {sup °}C. The air annealed sample was irradiated using Au{sup 9+} ions at the fluence 5 × 10{sup 11} ion/cm{sup 2} with 120 MeV energy. Effects of Swift Heavy Ion (SHI) irradiation on CdS–Bi{sub 2}S{sub 3} bi-layer thin films were studied. The results are explained on the basis annealing and high electronic excitation, using X-ray diffraction (XRD), Selective Electron Area Diffraction (SEAD), Atomic Force Microscopy (AFM), Raman Spectroscopy, UV spectroscopy and I–V characteristics. The photosensing property after illumination of visible light over the samples is studied. These as-deposited, annealed and irradiated bi-layer thin films are used to sense visible light at room temperature. - Graphical abstract: Schematic illustration of CdS–Bi{sub 2}S{sub 3} bi-layer thin film (a) As-deposited (b) Annealed (c) irradiated sample respectively (d) Model of bi-layer photosensor device (e) Graph of illumination intensity verses photosensitivity. - Highlights: • CdS–Bi{sub 2}S{sub 3} bi-layer thin film prepared at room temperature. • Irradiated using Au{sup 9+} ions at the fluence of 5 × 10{sup 11} ion/cm{sup 2} with 120 MeV energy. • Study of modification induced by irradiations. • Study of Photosensitivity after annealing and irradiation.

  14. Cs2AgBiBr6 single-crystal X-ray detectors with a low detection limit

    Science.gov (United States)

    Pan, Weicheng; Wu, Haodi; Luo, Jiajun; Deng, Zhenzhou; Ge, Cong; Chen, Chao; Jiang, Xiaowei; Yin, Wan-Jian; Niu, Guangda; Zhu, Lujun; Yin, Lixiao; Zhou, Ying; Xie, Qingguo; Ke, Xiaoxing; Sui, Manling; Tang, Jiang

    2017-11-01

    Sensitive X-ray detection is crucial for medical diagnosis, industrial inspection and scientific research. The recently described hybrid lead halide perovskites have demonstrated low-cost fabrication and outstanding performance for direct X-ray detection, but they all contain toxic Pb in a soluble form. Here, we report sensitive X-ray detectors using solution-processed double perovskite Cs2AgBiBr6 single crystals. Through thermal annealing and surface treatment, we largely eliminate Ag+/Bi3+ disordering and improve the crystal resistivity, resulting in a detector with a minimum detectable dose rate as low as 59.7 nGyair s-1, comparable to the latest record of 0.036 μGyair s-1 using CH3NH3PbBr3 single crystals. Suppressed ion migration in Cs2AgBiBr6 permits relatively large external bias, guaranteeing efficient charge collection without a substantial increase in noise current and thus enabling the low detection limit.

  15. Elastic properties of Cs2HgBr4 and Cs2CdBr4 crystals

    International Nuclear Information System (INIS)

    Kityk, A.V.; Zadorozhna, A.V.; Shchur, Y.I.; Martynyuk-Lototska, Y.I.; Burak, Y.; Vlokh, O.G.

    1998-01-01

    Using ultrasonic velocity measurements, all components of the elastic constant matrix C ij , elastic compliances matrix S ij , and linear compressibility constants matrix K ij of orthorhombic Cs 2 HgBr 4 and Cs 2 CdBr 4 crystals have been determined over a wide temperature range, including the region of the phase transition from the normal to the incommensurate phase. Results obtained are considered within the framework of the phenomenological theory. Preliminary analysis of the acoustical properties at room temperature clearly indicates that both crystals are relatively important materials for acousto-optical applications. Copyright (1998) CSIRO Australia

  16. Bandgap Engineering of Lead-Free Double Perovskite Cs2 AgBiBr6 through Trivalent Metal Alloying.

    Science.gov (United States)

    Du, Ke-Zhao; Meng, Weiwei; Wang, Xiaoming; Yan, Yanfa; Mitzi, David B

    2017-07-03

    The double perovskite family, A 2 M I M III X 6 , is a promising route to overcome the lead toxicity issue confronting the current photovoltaic (PV) standout, CH 3 NH 3 PbI 3 . Given the generally large indirect band gap within most known double perovskites, band-gap engineering provides an important approach for targeting outstanding PV performance within this family. Using Cs 2 AgBiBr 6 as host, band-gap engineering through alloying of In III /Sb III has been demonstrated in the current work. Cs 2 Ag(Bi 1-x M x )Br 6 (M=In, Sb) accommodates up to 75 % In III with increased band gap, and up to 37.5 % Sb III with reduced band gap; that is, enabling ca. 0.41 eV band gap modulation through introduction of the two metals, with smallest value of 1.86 eV for Cs 2 Ag(Bi 0.625 Sb 0.375 )Br 6 . Band structure calculations indicate that opposite band gap shift directions associated with Sb/In substitution arise from different atomic configurations for these atoms. Associated photoluminescence and environmental stability of the three-metal systems are also assessed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. In situ crystallization for fabrication of a core-satellite structured BiOBr-CdS heterostructure with excellent visible-light-responsive photoreactivity.

    Science.gov (United States)

    Guo, Yuxi; Huang, Hongwei; He, Ying; Tian, Na; Zhang, Tierui; Chu, Paul K; An, Qi; Zhang, Yihe

    2015-07-21

    We demonstrate the fabrication of a core-satellite structured BiOBr-CdS photocatalyst with highly efficient photocatalytic reactivity via a facile in situ crystallization approach at room temperature. The transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HR-TEM) results reveal that the BiOBr flakes are surrounded by CdS particles. The coverage of the satellites on the surface of the BiOBr nanosheets could be controlled by changing the content of the CdS, which contributes to the enhanced level of photocatalytic performance. The UV-vis diffuse reflection spectra demonstrate that the visible light absorption of the BiOBr-CdS photocatalyst is also enhanced by the CdS loaded. The excellent structural and spectral properties endow the BiOBr-CdS heterojunctions with improved photocatalytic performance pertaining to bisphenol A (BPA) degradation and photocurrent generation. Under visible light irradiation, the optimum photocatalytic activity of BiOBr-CdS at a molar ratio of 1 : 5 (CdS/BiOBr) is almost 2.8 times and 24.6 times as high as that of pure BiOBr and CdS. The remarkably enhanced photoreactivity should be attributed to the match in the energy levels and close core-satellite structural coupling between the CdS and BiOBr, which greatly facilitates the separation and transfer of photoinduced electron-hole pairs, as confirmed by photoluminescence (PL) and electrochemical impedance spectra (EIS). The present work sheds new light on the construction of highly efficient core-satellite heterojunctional photocatalysts for practical applications.

  18. Bi2Se3/CdS/TiO2 hybrid photoelectrode and its band-edge levels

    International Nuclear Information System (INIS)

    Zhang, Qi; Su, Jun; Zhang, Xianghui; Li, Jian; Zhang, Aiqing; Gao, Yihua

    2012-01-01

    Highlights: ► CVD synthesis of Bi 2 Se 3 nanoparticles. ► Bi 2 Se 3 and CdS co-sensitized TiO 2 nanorod arrays electrode was assembled by CVD. ► Direct physical contact heterojunctions were formed at the interfaces of electrode. ► Cascade structure of band-edge levels was formed in Bi 2 Se 3 /CdS/TiO 2 electrode. - Abstract: Bismuth selenide (Bi 2 Se 3 ) was chosen as the sensitizer to TiO 2 nanorod (NR) arrays photoelectrode to harvest infrared (IR) light for its narrow band gap. For utilizing more amount of IR solar energy, Bi 2 Se 3 nanoparticles (NPs) were grown up to a relative larger grain size. And, a cadmium sulfide (CdS) NPs intermediate layer was introduced to help, to coordinate, the structure of band-edge levels in Bi 2 Se 3 /CdS/TiO 2 electrode. Here, a chemical vapor deposition (CVD) strategy was introduced to assemble this kind of composite photoelectrode. And a cascade structure of band-edge levels constructed in it when achieving electrostatic equilibrium in Na 2 S/Na 2 SO 3 aqueous solution electrolyte revealed by electrochemical analysis method, which will facilitate the hydrogen generation.

  19. Bandgap engineering of lead-free double perovskite Cs_2AgBiBr_6 through trivalent metal alloying

    International Nuclear Information System (INIS)

    Du, Ke-zhao; Mitzi, David B.; Meng, Weiwei; Wang, Xiaoming; Yan, Yanfa

    2017-01-01

    The double perovskite family, A_2M"IM"I"I"IX_6, is a promising route to overcome the lead toxicity issue confronting the current photovoltaic (PV) standout, CH_3NH_3PbI_3. Given the generally large indirect band gap within most known double perovskites, band-gap engineering provides an important approach for targeting outstanding PV performance within this family. Using Cs_2AgBiBr_6 as host, band-gap engineering through alloying of In"I"I"I/Sb"I"I"I has been demonstrated in the current work. Cs_2Ag(Bi_1_-_xM_x)Br_6 (M=In, Sb) accommodates up to 75 % In"I"I"I with increased band gap, and up to 37.5 % Sb"I"I"I with reduced band gap; that is, enabling ca. 0.41 eV band gap modulation through introduction of the two metals, with smallest value of 1.86 eV for Cs_2Ag(Bi_0_._6_2_5Sb_0_._3_7_5)Br_6. Band structure calculations indicate that opposite band gap shift directions associated with Sb/In substitution arise from different atomic configurations for these atoms. Associated photoluminescence and environmental stability of the three-metal systems are also assessed. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Comparative retention of 60Co, 109Cd, and 137Cs following acute and chronic feeding in Bobwhite quail

    International Nuclear Information System (INIS)

    Anderson, S.H.; Dodson, G.J.; Van Hook, R.I.

    1975-01-01

    Tissue distribution of the radionuclides were found in the groups given the chronic exposure. Under chronic exposure to 60 Co, 109 Cd, and 137 Cs, quail rapidly accumulated these radioisotopes and the respective body burden concentrations began to level off after 11, 21, and 21 days of exposure. The biological half-lives for radioisotopes accumulated during the chronic feedings were 13 days for 60 Co, 8 days for 109 Cd, and 11 days for 137 Cs. In contrast, biological half-lives for these radioisotopes under acute feeding conditions (single four-hour feeding) were 15 days for 60 Co, 3 days for 109 Cd, and 10 days for 137 Cs. These results indicate that food chain behavior of 60 Co and 137 Cs in Bobwhite is similar following either acute or chronic exposure to contaminated food. For 109 Cd, biological retention in Bobwhite was longer under chronic exposure conditions. (U.S.)

  1. Enhanced sunlight-driven photocatalytic performance of Bi-doped CdMoO4 benefited from efficient separation of photogenerated charge pairs

    Science.gov (United States)

    Huang, Jiao; Liu, Huanhuan; Zhong, Junbo; Yang, Qi; Chen, Jiufu; Li, Jianzhang; Ma, Dongmei; duan, Ran

    2018-06-01

    In this paper, to further boost the photocatalytic performance of CdMoO4, Bi3+ was successfully doped into CdMoO4 by a facile microwave hydrothermal method. The Bi-doped CdMoO4 photocatalysts prepared were characterized by Brunauer-Emmett-Teller (BET) method, X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), electron spin-resonance (ESR) and surface photovoltage spectroscopy (SPS). The results exhibit that doping Bi3+ into CdMoO4 remarkably boosts the separation rate of photoinduced charge pairs and the specific surface area, decrease the crystal size, narrows the band gap of the CdMoO4 and induces the binding energy shift of Cd, all these advantageous factors result in the promoted photocatalytic performance of CdMoO4. Using rhodamine B (RhB) as model toxic pollutant, the photocatalytic activities of the photocatalysts were evaluated under a 500 W Xe lamp irradiation. When the molar ratio of Bi/Cd is 0.2%, Bi-CdMoO4 prepared displays the best photocatalytic performance, the photocatalytic performance of the 0.2% sample is more than twice of that of the reference CdMoO4.

  2. Sequential electro-deposition of Bi{sub 2}S{sub 3}/CdS films as co-sensitizer photoanodes for liquid junction solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Jana, Atanu; Hazra, Prasenjit; Hazra, Mukul; Datta, Jayati, E-mail: jayati_datta@rediffmail.com

    2016-11-01

    In this investigation multilayered conjugate films are formulated with Bi{sub 2}S{sub 3} and CdS nanoparticles (NPs) on FTO glass substrate. Thin layer Bi{sub 2}S{sub 3} was deposited and subsequently covered with various levels of CdS coating. Optical properties and XRD analysis of the films show existence of both the compound phases. The morphology of the films studied through electron microscopy reveals coverage of spherical CdS NPs on the network of Bi{sub 2}S{sub 3} NPs. The electrochemical impedance records and performances output characteristics of the n-type films show that the most efficient co-sensitizer matrix is produced with deep coating of CdS on thin layer of Bi{sub 2}S{sub 3}. - Highlights: • Multilayered Bi{sub 2}S{sub 3}/CdS conjugate films are formulated on FTO glass substrate. • Photo-degradation of Bi{sub 2}S{sub 3} is restricted by the coating of CdS layer. • High level of Cd coating on thin layer of Bi{sub 2}S{sub 3} have shown appreciable photocurrent output. • Photo-conversion efficiency of 0.93% is observed for the best conjugate film.

  3. Bandgap engineering of lead-free double perovskite Cs{sub 2}AgBiBr{sub 6} through trivalent metal alloying

    Energy Technology Data Exchange (ETDEWEB)

    Du, Ke-zhao; Mitzi, David B. [Department of Mechanical Engineering and Materials Science, and Department of Chemistry, Duke University, Durham, NC (United States); Meng, Weiwei; Wang, Xiaoming; Yan, Yanfa [Department of Physics and Astronomy and Wright Center for Photovoltaics Innovation and Commercialization, The University of Toledo, OH (United States)

    2017-07-03

    The double perovskite family, A{sub 2}M{sup I}M{sup III}X{sub 6}, is a promising route to overcome the lead toxicity issue confronting the current photovoltaic (PV) standout, CH{sub 3}NH{sub 3}PbI{sub 3}. Given the generally large indirect band gap within most known double perovskites, band-gap engineering provides an important approach for targeting outstanding PV performance within this family. Using Cs{sub 2}AgBiBr{sub 6} as host, band-gap engineering through alloying of In{sup III}/Sb{sup III} has been demonstrated in the current work. Cs{sub 2}Ag(Bi{sub 1-x}M{sub x})Br{sub 6} (M=In, Sb) accommodates up to 75 % In{sup III} with increased band gap, and up to 37.5 % Sb{sup III} with reduced band gap; that is, enabling ca. 0.41 eV band gap modulation through introduction of the two metals, with smallest value of 1.86 eV for Cs{sub 2}Ag(Bi{sub 0.625}Sb{sub 0.375})Br{sub 6}. Band structure calculations indicate that opposite band gap shift directions associated with Sb/In substitution arise from different atomic configurations for these atoms. Associated photoluminescence and environmental stability of the three-metal systems are also assessed. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Rietveld refinement of the orthorhombic Pbca structures of Rb2CdSi5O12, Cs2MnSiO5O12, Cs2CoSi5O12 and Cs2NiSi5O12 leucites by synchrotron X-ray powder diffraction

    International Nuclear Information System (INIS)

    Bell, A.M.T.; Henderson, C.M.B.

    1996-01-01

    Analysis of high-resolution synchrotron X-ray powder diffraction patterns for hydrothermally synthesized Rb 2 CdSi 5 O 12 and Cs 2 MnSi 5 O 12 leucite analogues, and dry-synthesized Cs 2 CoSi 5 O 12 and Cs 2 NiSi 5 O 12 leucite analogues showed that they have an orthorhombic Pbca structure. The structures have been refined by the Rietveld method, showing that the tetrahedrally coordinated atoms (Si, Cd, Mn, Co and Ni) are ordered on separate sites. The Cs 2 MnSi 5 O 12 , Cs 2 CoSi 5 O 12 and Cs 2 NiSi 5 O 12 leucite samples are unusual in containing SiO 4 tetrahedra which are more distorted, on average, than the larger MnO 4 , CoO 4 and NiO 4 tetrahedra. The JCPDS file numbers for Rb 2 CdSi 5 O 12 , Cs 2 MnSi 5 O 12 and Cs 2 CoSi 5 O 12 are 46-1491, 46-1492 and 46-1493, respectively. (orig.)

  5. MPEG-CS/Bmi-1RNAi Nanoparticles Synthesis and Its Targeted Inhibition Effect on CD133+ Laryngeal Stem Cells.

    Science.gov (United States)

    Wei, Xudong; He, Jian; Wang, Jingyu; Wang, Wei

    2018-03-01

    Previous studies have confirmed that CD133+ cells in laryngeal tumor tissue have the characteristics of cancer stem cells. Bmi-1 gene expression is central to the tumorigenicity of CD133+ cells. In this study, we tried to develop a new siRNA carrier system using chitosan-methoxypolyethylene nanoparticles (CS-mPEG-NPs) that exhibit higher tumor-targeting ability and enhanced gene silencing efficacy in CD133+ tumor stem cells. It is hoped to block the self-renewal and kill the stem cells of laryngeal carcinoma. The mPEG-CS-Bmi-1RNAi-NPs were synthesized and their characters were checked. The changes in invasion ability and sensitivity to radiotherapy and chemotherapy of CD133+Hep-2 tumor cells were observed after Bmi-1 gene silencing. The mPEG-CS-Bmi-1RNAi-NPs synthesized in this experiment have a regular spherical form, a mean size of 139.70 ±6.40 nm, an encapsulation efficiency of 85.21 ± 1.94%, with drug loading capacity of 18.47 ± 1.83%, as well as low cytotoxicity, providing good protection to the loaded gene, strong resistance to nuclease degradation and high gene transfection efficiency. After Bmi-1 gene silencing, the invasion ability of CD133+ cells was weakened. Co-cultured with paclitaxel, the survival rates of CD133+Bmi-1RNAi cells were lower. After radiotherapy, the mean growth inhibition rate of CD133+/Bmi-1RNAi cells was significantly lower than CD133+ cells. In conclusion, the mPEG-CS nano-carrier is an ideal vector in gene therapy, while silencing the Bmi-1 gene can enhance the sensitivity of CD133+ tumor stem cells to chemoradiotherapy and abate their invasion ability.

  6. High-pressure band-gap engineering in lead-free Cs{sub 2}AgBiBr{sub 6} double perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qian [Department of Chemistry, Southern University of Science and Technology, SUSTech, Shenzhen, Guangdong (China); College of Chemistry, Nankai University, Tianjin (China); Wang, Yonggang; Yang, Wenge [High Pressure Synergetic Consortium, HPSynC, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, IL (United States); Pan, Weicheng; Tang, Jiang [Wuhan National Laboratory for Optoelectronics, WNLO and School of Optical and Electronic Information, Huazhong University of Science and Technology, HUST, Wuhan (China); Zou, Bo [State Key Laboratory of Superhard Materials, Jilin University, Changchun (China); Quan, Zewei [Department of Chemistry, Southern University of Science and Technology, SUSTech, Shenzhen, Guangdong (China)

    2017-12-11

    Novel inorganic lead-free double perovskites with improved stability are regarded as alternatives to state-of-art hybrid lead halide perovskites in photovoltaic devices. The recently discovered Cs{sub 2}AgBiBr{sub 6} double perovskite exhibits attractive optical and electronic features, making it promising for various optoelectronic applications. However, its practical performance is hampered by the large band gap. In this work, remarkable band gap narrowing of Cs{sub 2}AgBiBr{sub 6} is, for the first time, achieved on inorganic photovoltaic double perovskites through high pressure treatments. Moreover, the narrowed band gap is partially retainable after releasing pressure, promoting its optoelectronic applications. This work not only provides novel insights into the structure-property relationship in lead-free double perovskites, but also offers new strategies for further development of advanced perovskite devices. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. High-Pressure Band-Gap Engineering in Lead-Free Cs 2 AgBiBr 6 Double Perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qian [Department of Chemistry, Southern University of Science and Technology, SUSTech, Shenzhen Guangdong 518055 P.R. China; College of Chemistry, Nankai University, Tianjin 300071 P.R. China; Wang, Yonggang [High Pressure Synergetic Consortium, HPSynC, Geophysical Laboratory, Carnegie Institution of Washington, Argonne IL 60439 USA; Pan, Weicheng [Wuhan National Laboratory for Optoelectronics, WNLO and School of Optical and Electronic Information, Huazhong University of Science and Technology, HUST, Wuhan 430074 P.R. China; Yang, Wenge [High Pressure Synergetic Consortium, HPSynC, Geophysical Laboratory, Carnegie Institution of Washington, Argonne IL 60439 USA; Zou, Bo [State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 P.R. China; Tang, Jiang [Wuhan National Laboratory for Optoelectronics, WNLO and School of Optical and Electronic Information, Huazhong University of Science and Technology, HUST, Wuhan 430074 P.R. China; Quan, Zewei [Department of Chemistry, Southern University of Science and Technology, SUSTech, Shenzhen Guangdong 518055 P.R. China

    2017-11-15

    Novel inorganic lead-free double perovskites with improved stability are regarded as alternatives to state-of-art hybrid lead halide perovskites in photovoltaic devices. The recently discovered Cs2AgBiBr6 double perovskite exhibits attractive optical and electronic features, making it promising for various optoelectronic applications. However, its practical performance is hampered by the large band gap. In this work, remarkable band gap narrowing of Cs2AgBiBr6 is, for the first time, achieved on inorganic photovoltaic double perovskites through high pressure treatments. Moreover, the narrowed band gap is partially retainable after releasing pressure, promoting its optoelectronic applications. This work not only provides novel insights into the structure–property relationship in lead-free double perovskites, but also offers new strategies for further development of advanced perovskite devices.

  8. Synthesis and characterization of PbO-CdO nanocomposite and its effect on (Bi,Pb)-2223 superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Yahya, Nabil A.A. [Thamar University, Physics Department, Faculty of Education, Thamar (Yemen); Al-Gaashani, R. [Thamar University, Physics Department, Faculty of Education, Thamar (Yemen); Qatar Environment and Energy Research Institute (QEERI), Hamad Bin Khalifa University (HBKU), Doha (Qatar); Abd-Shukor, R. [Universiti Kebangsaan Malaysia, School of Applied Physics, Bangi, Selangor (Malaysia)

    2017-03-15

    A PbO-CdO nanocomposite-added Bi{sub 1.6}Pb{sub 0.4}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} ((Bi,Pb)-2223) superconductor has been prepared. The effect of the PbO-CdO nanocomposite addition on the transport critical current density (J{sub c}) of (Bi,Pb)-2223 superconductor was investigated. The transition temperature (T{sub c-onset}), zero electrical resistance temperature (T{sub c-R=0}), and J{sub c} of the samples were measured by the four-probe method. Phase formation, structure, and microstructure of samples were investigated. The distribution of nanoparticle size was determined. The results indicated that the PbO-CdO-added samples showed larger grain size and an increased volume fraction of high-T{sub c} phase (Bi-2223) compared to the non-added sample. A slight increase in T{sub c-R=0} of x = 0.15 wt% was observed. J{sub c} of the PbO-CdO nanocomposite-added samples was significantly higher than for the non-added sample. That could be explained by the possibility that the PbO-CdO nanocomposite acts as an effective flux pinning center in (Bi,Pb)-2223. At 77 K, J{sub c} of x = 0.15 wt% added sample was more than 20 times larger than J{sub c} of the non-added sample (x = 0 wt%). A combined effect of enhanced flux pinning, increased fraction of high-T{sub c} phase and improved grain size, which led to increase in the J{sub c} of added samples, is discussed. (orig.)

  9. Self-organization of Au–CdSe hybrid nanoflowers at different length scales via bi-functional diamine linkers

    Energy Technology Data Exchange (ETDEWEB)

    AbouZeid, Khaled Mohamed [Virginia Commonwealth University, Department of Chemistry (United States); Mohamed, Mona Bakr [Cairo University, National Institute of Laser Enhanced Science (NILES) (Egypt); El-Shall, M. Samy, E-mail: mselshal@vcu.edu [Virginia Commonwealth University, Department of Chemistry (United States)

    2016-01-15

    This work introduces a series of molecular bridging bi-functional linkers to produce laterally self-assembled nanostructures of the Au–CdSe nanoflowers on different length scales ranging from 10 nm to 100 microns. Assembly of Au nanocrystals within amorphous CdSe rods is found in the early stages of the growth of the Au–CdSe nanoflowers. The Au–CdSe nanoflowers are formed through a one-pot low temperature (150 °C) process where CdSe clusters are adsorbed on the surface of the Au cores, and they then start to form multiple arms and branches resulting in flower-shaped hybrid nanostructures. More complex assembly at a micron length scale can be achieved by means of bi-functional capping agents with appropriate alkyl chain lengths, such as 1,12-diaminododecane.

  10. Biosorption of Cd(II) and Cs(I) from aqueous solution by live and dead cells of Saccharomyces carlsbergensis PTCC 5051.

    Science.gov (United States)

    Sayyadi, Shayan; Ahmady-Asbchin, Salman; Kamali, Kasra

    2018-02-01

    The biosorption characteristics of Cd(II) and Cs(I) using live and dead cells of Saccharomyces carlsbergensis PTCC 5051 as biosorbents have been investigated in the present research. The influence of different experimental parameters such as initial pH (pHi), shaking rate, sorption time and initial metal concentration was evaluated. The optimum pH was obtained as 4 for Cd(II) and 7 for Cs(I). The experimental adsorption data were fitted to the Langmuir linear equation adsorption model. The highest metal uptake values of 0.593 and 0.473 mmol g -1 were calculated for Cd(II) and Cs(I), respectively. The results of Fourier transform infrared analysis suggested the involvement of amine, carboxyl and hydroxyl groups during the biosorption process and also indicated that more functional groups were involved in the biosorption process of live adsorbents, compared with those linked to dead biomass. The results showed that the biomass of S. carlsbergensis PTCC 5051 is a suitable biosorbent for the removal of Cd(II) and Cs(I) from the aqueous solutions.

  11. Construction of an all-solid-state artificial Z-scheme system consisting of Bi2WO6/Au/CdS nanostructure for photocatalytic CO2 reduction into renewable hydrocarbon fuel

    Science.gov (United States)

    Wang, Meng; Han, Qiutong; Li, Liang; Tang, Lanqin; Li, Haijin; Zhou, Yong; Zou, Zhigang

    2017-07-01

    An all-solid-state Bi2WO6/Au/CdS Z-scheme system was constructed for the photocatalytic reduction of CO2 into methane in the presence of water vapor. This Z-scheme consists of ultrathin Bi2WO6 nanoplates and CdS nanoparticles as photocatalysts, and a Au nanoparticle as a solid electron mediator offering a high speed charge transfer channel and leading to more efficient spatial separation of electron-hole pairs. The photo-generated electrons from the conduction band (CB) of Bi2WO6 transfer to the Au, and then release to the valence band (VB) of CdS to recombine with the holes of CdS. It allows the electrons remaining in the CB of CdS and holes in the VB of Bi2WO6 to possess strong reduction and oxidation powers, respectively, leading the Bi2WO6/Au/CdS to exhibit high photocatalytic reduction of CO2, relative to bare Bi2WO6, Bi2WO6/Au, and Bi2WO6/CdS. The depressed hole density on CdS also enhances the stability of the CdS against photocorrosion.

  12. The crystal structure of kudriavite, (Cd,Pb)Bi2S4

    DEFF Research Database (Denmark)

    Balic Zunic, Tonci; Makovicky, Emil

    2007-01-01

    The crystal structure of kudriavite, (Cd,Pb)Bi2S4, a new mineral species, was solved from single-crystal X-ray-diffraction data and refi ned to R = 4.9% (4.3% for a model with split mixed-cation sites). Lattice parameters are a 13.095(1), b 4.0032(3), c 14.711(1) Å, 115.59(1)°, V 695.6(1) Å3....... The structure is equivalent to that of synthetic CdBi2S4, space group C2/m, Z = 4, and represents a pavonite homologue, N = 3. It is built of three-octahedron-thick columns of (311)PbS-like slabs combined by "unitcell twinning" in a quasi-mirror-glide succession. The slabs, which are intrinsically of the same...... topology, differ in the coordination state of bordering cations because of the relative positions of the adjacent layers. In the slabs of type I (the "non-accreting" slab common to all pavonite homologues), the central columns of octahedra are fl anked by half-octahedral (square-pyramidal) coordinations...

  13. Structural phase transitions in CsPbCl/sub 3/ and RbCdCl/sub 3/

    Energy Technology Data Exchange (ETDEWEB)

    Plesko, S; Kind, R; Roos, J [Swiss Federal Inst. of Technology, Zuerich. Lab. of Solid State Physics

    1978-08-01

    Structural phase transitions in CsPbCl/sub 3/ have been investigated by /sup 133/Cs and /sup 87/Rb nuclear magnetic resonance. The space groups of the room temperature phase in CsPbCl/sub 3/ and of two unknown phases in RbCdCl/sub 3/ could be clarified. Thus both perovskites show the same phase sequence from cubic Pm3m-O sub(h)sup(1) to tetragonal P4/mbm-D sub(4h)sup(5), orthorhombic Cmcm-D sub(2h)sup(17) and further orthorhombic Pnma-D sub(2h)sup(16).

  14. Enhanced photoelectrochemical activity of electro-synthesized CdS-Bi2S3 composite films grown with self-designed cross-linked structure

    International Nuclear Information System (INIS)

    Jana, A.; Bhattacharya, C.; Datta, J.

    2010-01-01

    In the present investigation thin semiconductor films of CdS, Bi 2 S 3 and their intermixed composite films have been electro-synthesized onto conducting glass substrate from nonaqueous bath containing various levels of the precursor salts of Cd 2+ and Bi 3+ . Spectrophotometric measurements determine the band gap energies of the composite films at ∼2.53 eV and ∼1.37 eV corresponding to the binary systems CdS and Bi 2 S 3 , respectively. The film matrices exhibit a unique structure of cross-linked nanoporous Bi 2 S 3 mesh containing spherical shaped CdS crystals distributed uniformly on the top of the surface as detected from the morphological studies through scanning electron microscopy and transmission electron microscopy. X-ray diffraction studies show crystalline structure of the films of which the chemical compositions were determined through energy dispersive analysis of X-ray. The film matrices enriched with Cd exhibit high dielectric property as obtained from the capacitance measurement and substantial thermal stability derived from thermogravimetry and differential thermal analysis. These films are found to be highly fluorescent in nature when subjected to spectrofluorimetric analysis. The Raman spectral data exhibit characteristic peaks that are associated with Cd-S and Bi-S bonds as well as the defects created by metal oxides. The spectrum also demonstrates that the changes in the relative position of the overtone bands are associated with compositional variation of the film surface. The study of electrochemical polarization of different films, derives the inherent stability of the matrices towards dissolution. This was followed by anodic stripping voltammetry to estimate the dissolved cations during polarization. Photoelectrochemical measurements demonstrate n-type semiconductivity of the films with high order of donor density and reasonable photoactivity under illuminated condition. It may be summarized that the blended intermix of CdS-Bi 2 S 3

  15. Elastic properties of Cs{sub 2}HgBr{sub 4} and Cs{sub 2}CdBr{sub 4} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kityk, A.V.; Zadorozhna, A.V.; Shchur, Y.I.; Martynyuk-Lototska, Y.I.; Burak, Y.; Vlokh, O.G. [Institute of Physical Optics, Lvov (Ukraine)

    1998-12-31

    Using ultrasonic velocity measurements, all components of the elastic constant matrix C{sub ij} , elastic compliances matrix S{sub ij}, and linear compressibility constants matrix K{sub ij} of orthorhombic Cs{sub 2}HgBr{sub 4} and Cs{sub 2}CdBr{sub 4} crystals have been determined over a wide temperature range, including the region of the phase transition from the normal to the incommensurate phase. Results obtained are considered within the framework of the phenomenological theory. Preliminary analysis of the acoustical properties at room temperature clearly indicates that both crystals are relatively important materials for acousto-optical applications. Copyright (1998) CSIRO Australia 16 refs., 1 tab. 8 figs. The URL for the electronic version of this article is http://www.publish.csiro.au/journals/ajp/electronic.html

  16. Intrinsic Instability of Cs2In(I)M(III)X6 (M = Bi, Sb; X = Halogen) Double Perovskites: A Combined Density Functional Theory and Experimental Study.

    Science.gov (United States)

    Xiao, Zewen; Du, Ke-Zhao; Meng, Weiwei; Wang, Jianbo; Mitzi, David B; Yan, Yanfa

    2017-05-03

    Recently, there has been substantial interest in developing double-B-cation halide perovskites, which hold the potential to overcome the toxicity and instability issues inherent within emerging lead halide-based solar absorber materials. Among all double perovskites investigated, In(I)-based Cs 2 InBiCl 6 and Cs 2 InSbCl 6 have been proposed as promising thin-film photovoltaic absorber candidates, with computational examination predicting suitable materials properties, including direct bandgap and small effective masses for both electrons and holes. In this study, we report the intrinsic instability of Cs 2 In(I)M(III)X 6 (M = Bi, Sb; X = halogen) double perovskites by a combination of density functional theory and experimental study. Our results suggest that the In(I)-based double perovskites are unstable against oxidation into In(III)-based compounds. Further, the results show the need to consider reduction-oxidation (redox) chemistry when predicting stability of new prospective electronic materials, especially when less common oxidation states are involved.

  17. Hydrothermal synthesis of CdS/Bi{sub 2}MoO{sub 6} heterojunction photocatalysts with excellent visible-light-driven photocatalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yi; Yan, Xu; Liu, Chunbo; Hong, Yuanzhi; Zhu, Lin; Zhou, Mingjun; Shi, Weidong, E-mail: swd1978@ujs.edu.cn

    2015-10-30

    Graphical abstract: - Highlights: • The novel CdS/Bi{sub 2}MoO{sub 6} heterojunction were synthesized for the first time via a two-step hydrothermal process. • The CdS/Bi{sub 2}MoO{sub 6} heterojunction exhibited an excellent visible-light-driven photocatalytic activity for RhB degradation. • The photocatalytic activity of this heterojunction also evaluated by TC, MB degradation. • The mechanism of this photocatalysis system was firstly proposed. - Abstract: A novel CdS/Bi{sub 2}MoO{sub 6} heterojunction photocatalysts were successfully prepared via two-step hydrothermal methods. The prepared samples were characterized by various physicochemical techniques, such as XRD, SEM, TEM, HRTEM, XPS, UV–vis and PL. The obtained samples exhibited highly photocatalytic activity toward the degradation of the different kinds of organic dyes and tetracycline in aqueous solution under visible light irradiation (λ > 420 nm). The optimum photocatalytic efficiency of CdS-2 sample for the degradation rhodamine B (RhB) was about 25.3 and 3.7 times higher than that of individual CdS and Bi{sub 2}MoO{sub 6}, respectively. In addition, the possible photocatalytic mechanism was analyzed by different active species trapping experiments. The results indicated that the h{sup +} and ·O{sub 2}{sup −} were the main active species for the photocatalytic degradation of RhB. Moreover, the prepared sample shows good stability and recyclability properties which are beneficial for its practical application.

  18. Effect of swift heavy ion irradiation on structural and opto-electrical properties of bi-layer CdS-Bi2S3 thin films prepared by solution growth technique at room temperature

    Science.gov (United States)

    Shaikh, Shaheed U.; Siddiqui, Farha Y.; Desale, Deepali J.; Ghule, Anil V.; Singh, Fouran; Kulriya, Pawan K.; Sharma, Ramphal

    2015-01-01

    CdS-Bi2S3 bi-layer thin films have been deposited by chemical bath deposition method on Indium Tin Oxide glass substrate at room temperature. The as-deposited thin films were annealed at 250 °C in an air atmosphere for 1 h. An air annealed thin film was irradiated using Au9+ ions with the energy of 120 MeV at fluence 5×1012 ions/cm2 using tandem pelletron accelerator. The irradiation induced modifications were studied using X-ray diffraction (XRD), Atomic Force Microscopy (AFM), Raman spectroscopy, UV spectroscopy and I-V characteristics. XRD study reveals that the as-deposited thin films were nanocrystalline in nature. The decrease in crystallite size, increase in energy band gap and resistivity were observed after irradiation. Results are explained on the basis of energy deposited by the electronic loss after irradiation. The comparative results of as-deposited, air annealed and irradiated CdS-Bi2S3 bi-layer thin films are presented.

  19. Cucumber metal tolerance protein CsMTP9 is a plasma membrane H⁺-coupled antiporter involved in the Mn²⁺ and Cd²⁺ efflux from root cells.

    Science.gov (United States)

    Migocka, Magdalena; Papierniak, Anna; Kosieradzka, Anna; Posyniak, Ewelina; Maciaszczyk-Dziubinska, Ewa; Biskup, Robert; Garbiec, Arnold; Marchewka, Tadeusz

    2015-12-01

    Members of the plant metal tolerance protein (MTP) family have been classified into three major groups - Zn-CDF, Mn-CDF and Zn/Fe-CDF - however, the selectivity of most of the MTPs has not been confirmed yet. Cucumber gene CsMTP9 encoding a putative CDF transporter homologous to members of the Mn-CDF cluster is expressed exclusively in roots. The relative abundance of CsMTP9 transcript and protein in roots is significantly increased under Mn excess and Cd. Immunolocalization with specific antibodies revealed that CsMTP9 is a plasma membrane transporter that localizes to the inner PM domain of root endodermal cells. The plasma membrane localization of CsMTP9 was confirmed by the expression of the fusion proteins of GFP (green fluorescent protein) and CsMTP9 in yeast and protoplasts prepared from Arabidopsis cells. In yeast, CsMTP9 transports Mn(2+) and Cd(2+) via a proton-antiport mechanism with an apparent Km values of approximately 10 μm and 2.5 μm for Mn(2+) and Cd(2+) , respectively. In addition, CsMTP9 expression in yeast rescues the Mn- and Cd-hypersensitive phenotypes through the enhanced efflux of Mn(2+) and Cd(2+) from yeast cells. Similarly, the overexpression of CsMTP9 in A. thaliana confers increased resistance of plants to Mn excess and Cd but not to other heavy metals and leads to the enhanced translocation of manganese and cadmium from roots to shoots. These findings indicate that CsMTP9 is a plasma membrane H(+) -coupled Mn(2+) and Cd(2+) antiporter involved in the efflux of manganese and cadmium from cucumber root cells by the transport of both metals from endodermis into vascular cylinder. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  20. Depuration and uptake kinetics of I, CS, MN, ZN and CD by the earthworm (lumbricus terrestris) in radiotracer-spiked litter

    International Nuclear Information System (INIS)

    Sheppard, S.C.; Evenden, W.G.; Cornwell, T.C.

    1997-01-01

    The relative depuration and uptake kinetics of contaminants should be known to interpret appropriately the use of organisms such as earthworms in environmental bioassays and monitoring. For example, 14-d earthworm bioassays should be interpreted with the knowledge that some contaminants will continue to accumulate in tissues for months. The radiotracers 125 I, 134 Cs, 54 Mn, 65 Zn, and 109 Cd were applied to deciduous litter and specimens of Lumbricus terrestris were exposed, either to litter alone or to litter on the top of soil columns. Depuration was monitored for 120 d and uptake, in a separate experiment, for 20 d. Both depuration and uptake were described using two-phase, first-order statistical models. Gut clearance had a mean half-time of 1.4 d. The mean half-time for physiological depuration decreased from I (210 d) > Cd (150 d) > Zn (69 d) > Mn (40 d) > Cs (24 d). Both the deputation and the uptake experiments were necessary to resolve even partially the multiphase processes. Earthworm/soil dry weight concentration ratios decreased from Cd > Zn > I ≥ Cs ≥ Mn. The very slow kinetics indicate that tissue concentrations will increase continuously for a long time, with important implications for subsequent food-chain transfers. (author)

  1. Slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry for the determination of trace Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wei-Ni [Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan (China); Jiang, Shiuh-Jen, E-mail: sjjiang@faculty.nsysu.edu.tw [Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan (China); Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Chen, Yen-Ling [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Sahayam, A.C. [National Centre for Compositional Characterisation of Materials (CCCM), Hyderabad (India)

    2015-02-20

    Highlights: • Determination of Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions in a single run. • Accurate analysis using isotope dilution and standard addition methods. • Vapor generation ICP-MS yielded superior detection limits compared to ETV-ICP-MS. • No sample dissolution increased sample through put. • Analysis of GBW09305 Cosmetic (Cream) reference material for accuracy. - Abstract: A slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) method has been developed for the determination of Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions using flow injection (FI) vapor generation (VG) as the sample introduction system. A slurry containing 2% m/v lotion, 2% m/v thiourea, 0.05% m/v L-cysteine, 0.5 μg mL{sup −1} Co(II), 0.1% m/v Triton X-100 and 1.2% v/v HCl was injected into a VG-ICP-MS system for the determination of Ge, As, Cd, Sb, Hg and Bi without dissolution and mineralization. Because the sensitivities of the analytes in the slurry and that of aqueous solution were quite different, an isotope dilution method and a standard addition method were used for the determination. This method has been validated by the determination of Ge, As, Cd, Sb, Hg and Bi in GBW09305 Cosmetic (Cream) reference material. The method was also applied for the determination of Ge, As, Cd, Sb, Hg and Bi in three cosmetic lotion samples obtained locally. The analysis results of the reference material agreed with the certified value and/or ETV-ICP-MS results. The detection limit estimated from the standard addition curve was 0.025, 0.1, 0.2, 0.1, 0.15, and 0.03 ng g{sup −1} for Ge, As, Cd, Sb, Hg and Bi, respectively, in original cosmetic lotion sample.

  2. Slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry for the determination of trace Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions

    International Nuclear Information System (INIS)

    Chen, Wei-Ni; Jiang, Shiuh-Jen; Chen, Yen-Ling; Sahayam, A.C.

    2015-01-01

    Highlights: • Determination of Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions in a single run. • Accurate analysis using isotope dilution and standard addition methods. • Vapor generation ICP-MS yielded superior detection limits compared to ETV-ICP-MS. • No sample dissolution increased sample through put. • Analysis of GBW09305 Cosmetic (Cream) reference material for accuracy. - Abstract: A slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) method has been developed for the determination of Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions using flow injection (FI) vapor generation (VG) as the sample introduction system. A slurry containing 2% m/v lotion, 2% m/v thiourea, 0.05% m/v L-cysteine, 0.5 μg mL −1 Co(II), 0.1% m/v Triton X-100 and 1.2% v/v HCl was injected into a VG-ICP-MS system for the determination of Ge, As, Cd, Sb, Hg and Bi without dissolution and mineralization. Because the sensitivities of the analytes in the slurry and that of aqueous solution were quite different, an isotope dilution method and a standard addition method were used for the determination. This method has been validated by the determination of Ge, As, Cd, Sb, Hg and Bi in GBW09305 Cosmetic (Cream) reference material. The method was also applied for the determination of Ge, As, Cd, Sb, Hg and Bi in three cosmetic lotion samples obtained locally. The analysis results of the reference material agreed with the certified value and/or ETV-ICP-MS results. The detection limit estimated from the standard addition curve was 0.025, 0.1, 0.2, 0.1, 0.15, and 0.03 ng g −1 for Ge, As, Cd, Sb, Hg and Bi, respectively, in original cosmetic lotion sample

  3. 137Cs distribution in guava trees

    International Nuclear Information System (INIS)

    Mosquera, B.; Veiga, R.; Mangia, L.; Carvalho, C.; Estellita, L.; Uzeda, D.; Facure, A.; Violini, B.; Anjos, R.M.

    2004-01-01

    This paper presents results of 137 Cs concentration measured from a guava tree cultivated after the first decontamination work of one of the sites where the worst Brazilian radiological accident occurred. The present work aims to verify how the 137 Cs is transported and distributed along the tropical trees. Bi-dimensional analyses of the radial distribution of 137 Cs in the main trunk are also presented. Neither symmetrical nor homogeneous behaviors of the specific activity distribution in the tree rings were observed. (author)

  4. How grain boundaries affect the efficiency of poly-CdTe solar-cells: A fundamental atomic-scale study of grain boundary dislocation cores using CdTe bi-crystal thin films.

    Energy Technology Data Exchange (ETDEWEB)

    Klie, Robert [Univ. of Illinois, Chicago, IL (United States)

    2016-10-25

    It is now widely accepted that grain boundaries in poly-crystalline CdTe thin film devices have a detrimental effect on the minority carrier lifetimes, the open circuit voltage and therefore the overall solar-cell performance. The goal of this project was to develop a fundamental understanding of the role of grain boundaries in CdTe on the carrier life-time, open-circuit voltage, Voc, and the diffusion of impurities. To achieve this goal, i) CdTe bi-crystals were fabricated with various misorientation angels, ii) the atomic- and electronic structures of the grain boundaries were characterized using scanning transmission electron microscopy (STEM), and iii) first-principles density functional theory modeling was performed on the structures determined by STEM to predict the grain boundary potential. The transport properties and minority carrier lifetimes of the bi-crystal grain boundaries were measured using a variety of approaches, including TRPL, and provided feedback to the characterization and modeling effort about the effectiveness of the proposed models.

  5. Comparative study of A-site order in the lead-free bismuth titanates M1/2Bi1/2TiO3 (M=Li, Na, K, Rb, Cs, Ag, Tl) from first-principles

    International Nuclear Information System (INIS)

    Gröting, Melanie; Albe, Karsten

    2014-01-01

    We investigate the possibility of enhancing chemical order in the relaxor ferroelectric Na 1/2 Bi 1/2 TiO 3 upon substitution of Na + by other monovalent cations M + using total energy calculations based on density functional theory. All chemically available monovalent cations M + , which are Li, Na, Ag, K, Tl, Rb and Cs, are considered and an analysis of the structurally relaxed structures in terms of symmetry-adapted distortion modes is given in order to quantify the chemically induced structural distortions. We demonstrate that the replacement of Na + by other monovalent cations can hardly alter the tendency of chemical order with respect to Na 1/2 Bi 1/2 TiO 3 . Only Tl 1/2 Bi 1/2 TiO 3 and Ag 1/2 Bi 1/2 TiO 3 show enhanced tendency for chemical ordering. Both heavy metals behave similar to the light alkali metals in terms of structural relaxations and relative stabilities of the ordered configurations. Although a comparison of the Goldschmidt factors of components (M TiO 3 ) − reveals for Tl a value above the upper stability limit for perovskites, the additional lone-pair effect of Tl + stabilizes the ordered structure. - Graphical abstract: Amplitudes of chemically induced distortion modes in different ordered perovskites M 1/2 Bi 1/2 TiO 3 and visualisation of atomic displacements associated with distortion mode X + 1 in the 001-ordered compounds Li 1/2 Bi 1/2 TiO 3 and Cs 1/2 Bi 1/2 TiO 3 . Due to a substantial size mismatch between bismuth (green) and caesium (dark blue), incorporation of the latter leads to enhanced displacements of oxygen atoms (red) and suppresses displacements of titanium (silver) as compared to lithium (light blue) or other smaller monovalent cations. - Highlights: • Lead-free A-site mixed bismuth titanates M 1/2 Bi 1/2 TiO 3 are studied by first-principles calculations. • Investigation of chemical ordering tendency for M=Li, Na, K, Rb, Cs, Ag, and Tl. • Group theoretical analysis of different ordered structures. • Ag and Tl

  6. [Plasma scavenger receptor BI and CD36 expression change and susceptibility of atherosclerosis in patients post liver transplantation].

    Science.gov (United States)

    Chen, Xin; Xue, Jinhong; Zhang, Shuyi; Sun, Liying; Lu, Chengzhi

    2014-02-01

    To explore the association between expression changes of plasma macrophages scavenger receptor (SR)-BI and CD36 and risk of arteriosclerosis in end-stage liver disease (ESLD) patients post liver transplantation. A total of 20 liver transplantation patients were included. Clinical data including blood pressure, blood lipid, blood glucose, incidence of new-onset cardiovascular events were obtained. Plasma macrophages scavenger receptor SR-BIand CD36 expressions were detected by polymerase chain reaction (RT-PCR) and Western-blot before and at 1 year after liver transplantation. The serum levels of TC [(5.34 ± 0.87) mmol/L vs. (4.27 ± 0.91) mmol/L], TG [(2.47 ± 0.81) mmol/L vs. (1.02 ± 0.49) mmol/L] and LDL-C [(3.36 ± 0.67) mmol/L vs. (2.14 ± 0.74) mmol/L] were significantly increased (P compared to before-transplantation levels. One patient developed non-ST segment elevation myocardial infarction and treated with percutaneous coronary intervention, another patient developed atrial fibrillation at one year after transplantation. The plasma mRNA expression of SR-BI was reduced (20.44 ± 0.60 vs. 23.12 ± 0.69, P compare with that of before the transplantation. Similarly, the plasma protein expression of SR-BIwas reduced (0.21 ± 0.13 vs. 0.64 ± 0.28, P compare with that of before the transplantation. Plasma expression changes of SR-BI and CD36 might contribute to the dyslipidemia and contribute to the atherosclerosis susceptibility after liver transplantation.

  7. {sup 137}Cs distribution in guava trees

    Energy Technology Data Exchange (ETDEWEB)

    Mosquera, B.; Veiga, R.; Mangia, L.; Carvalho, C.; Estellita, L.; Uzeda, D.; Facure, A.; Violini, B.; Anjos, R.M. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Fisica

    2004-09-15

    This paper presents results of {sup 137}Cs concentration measured from a guava tree cultivated after the first decontamination work of one of the sites where the worst Brazilian radiological accident occurred. The present work aims to verify how the {sup 137}Cs is transported and distributed along the tropical trees. Bi-dimensional analyses of the radial distribution of {sup 137}Cs in the main trunk are also presented. Neither symmetrical nor homogeneous behaviors of the specific activity distribution in the tree rings were observed. (author)

  8. New quaternary alkali metal cadmium selenites, A2Cd(SeO3)2 (A = K, Rb, and Cs) and Li2Cd3(SeO3)4

    Science.gov (United States)

    Lü, Minfeng; Jo, Hongil; Oh, Seung-Jin; Ok, Kang Min

    2017-12-01

    A series of new alkali metal cadmium selenites, A2Cd(SeO3)2 (A = K, Rb, and Cs) and Li2Cd3(SeO3)4 have been synthesized in phase pure forms through hydrothermal and solid-state reactions. Structural analyses using single crystal X-ray diffraction indicate that while A2Cd(SeO3)2 and Li2Cd3(SeO3)4 reveal layered structures consisting of CdO6 and SeO3 polyhedra, their symmetry, bonding modes, and the orientation of lone pairs on Se4+ cations are different. A closer examination suggests that the observed structural variations found in the reported materials are attributed to the structure-directing effect of alkali metal cations with different sizes. Scanning electron microscopy/energy dispersive analysis by X-ray, thermogravimetric analysis, Infrared and UV-vis diffuse reflectance spectroscopy, transformation reactions under hydrothermal conditions, and local dipole moment calculations for the reported materials are also reported.

  9. Sorption of radionuclides from Pb-Bi melt. Report 1

    International Nuclear Information System (INIS)

    Konovalov, Eh.E.; Il'icheva, N.S.; Trifonova, O.E.

    2015-01-01

    Results of laboratory investigations of sorption and interfacial distribution of 54 Mn, 59 Fe, 60 Co, 106 Ru, 125 Sb, 137 Cs, 144 Ce, 154,155 Eu and 235,238 U radionuclides in the system Pb-Bi melt - steel surface are analyzed. It is shown that 106 Ru and 125 Sb are concentrated in Pb-Bi melt and other radionuclides with higher oxygen affinity are sorbed on oxide deposits on structural materials. Temperature dependences of sorption efficiency of radionuclides are studied. It is shown that there is sharp increase of this value for all radionuclides near the temperature range 350-400 deg C. Recommendations are given on the use of 106 Ru and 125 Sb as a reference for fuel element rupture detection system with radiometric monitoring of coolant melt samples and 137 Cs, 134 Cs, 134m Cs with radiometric monitoring of sorbing samples [ru

  10. Effect of Silicon on Activity Coefficients of P, Bi, Cd, Sn, and Ag in Liquid Fe-Si, and Implications for Core Formation

    Science.gov (United States)

    Righter, K.; Pando, K.; Ross, D. K.; Righter, M.; Lapen, T. J.

    2018-01-01

    Cores of differentiated bodies (Earth, Mars, Mercury, Moon, Vesta) contain light elements such as S, C, Si, and O. We have previously measured small effects of Si on Ni and Co, and larger effects on Mo, Ge, Sb, As metal/silicate partitioning. The effect of Si on metal-silicate partitioning has been quantified for many siderophile elements, but there are a few key elements for which the effects are not yet quantified. Here we report new experiments designed to quantify the effect of Si on the partitioning of Bi, Cd, Sn, Ag, and P between metal and silicate melt. The results will be applied to Earth, Mars, Moon, and Vesta, for which we have good constraints on the mantle Bi, Cd, Sn, Ag, and P concentrations from mantle and/or basalt samples.

  11. Electronic structure and transport in the low-temperature thermoelectric CsBi4Te6: Semiclassical transport equations

    DEFF Research Database (Denmark)

    Lykke, Lars; Iversen, Bo Brummerstedt; Madsen, Georg

    2006-01-01

    The band structure of the low-temperature thermoelectric material, CsBi4Te6, is calculated and analyzed using the semiclassic transport equations. It is shown that to obtain a quantitative agreement with measured transport properties, a band gap of 0.08 eV must be enforced. A gap in reasonable...... agreement with experiment was obtained using the generalized gradient functional of Engel and Vosko [E. Engel and S. H. Vosko, Phys. Rev. B 47, 13164 (1993)]. We found that the experimental p-type sample has a carrier concentration close to optimal. Furthermore, the conduction bands have a form equally well...

  12. Adsorbate-induced modification of electronic band structure of epitaxial Bi(111) films

    Energy Technology Data Exchange (ETDEWEB)

    Matetskiy, A.V., E-mail: mateckij@iacp.dvo.ru [Institute of Automation and Control Processes FEB RAS, 5 Radio Street, 690041 Vladivostok (Russian Federation); Bondarenko, L.V.; Tupchaya, A.Y.; Gruznev, D.V. [Institute of Automation and Control Processes FEB RAS, 5 Radio Street, 690041 Vladivostok (Russian Federation); Eremeev, S.V. [Institute of Strength Physics and Materials Science, 634021 Tomsk (Russian Federation); Tomsk State University, 634050 Tomsk (Russian Federation); Zotov, A.V. [Institute of Automation and Control Processes FEB RAS, 5 Radio Street, 690041 Vladivostok (Russian Federation); School of Natural Sciences, Far Eastern Federal University, 690950 Vladivostok (Russian Federation); Department of Electronics, Vladivostok State University of Economics and Service, 690600 Vladivostok (Russian Federation); Saranin, A.A. [Institute of Automation and Control Processes FEB RAS, 5 Radio Street, 690041 Vladivostok (Russian Federation); School of Natural Sciences, Far Eastern Federal University, 690950 Vladivostok (Russian Federation)

    2017-06-01

    Highlights: • Modification of electronic properties of ultrathin Bi films by adsorbates is demonstrated. • Due to electron doping from Cs adatoms, surface-state bands shift to higher binding energies. • As a result, only electron pockets are left in the Fermi map. • Tin acts as an acceptor dopant for Bi, shifting Fermi level upward. • As a result, only hole pockets are left in the Fermi map. - Abstract: Changes of the electronic band structure of Bi(111) films on Si(111) induced by Cs and Sn adsorption have been studied using angle-resolved photoemission spectroscopy and density functional theory calculations. It has been found that small amounts of Cs when it presents at the surface in a form of the adatom gas leads to shifting of the surface and quantum well states to the higher binding energies due to the electron donation from adsorbate to the Bi film. In contrast, adsorbed Sn dissolves into the Bi film bulk upon heating and acts as an acceptor dopant, that results in shifting of the surface and quantum well states upward to the lower binding energies. These results pave the way to manipulate with the Bi thin film electron band structure allowing to achieve a certain type of conductivity (electron or hole) with a single spin channel at the Fermi level making the adsorbate-modified Bi a reliable base for prospective spintronics applications.

  13. Coordination polyhedra CsCln in crystals

    International Nuclear Information System (INIS)

    Serezhkin, V.N.; Serezhkina, L.B.

    1999-01-01

    Characteristics of the Voronoi-Dirichlet polyhedrons are estimated for 133 crystallographic cesium atoms in chlorides Cs x M y Cl z (M=Cd, Sc, V, Nb, Mo, W, Ru, Re, etc.). It is found that cesium atoms have coordination numbers 6,8,9,10, 11 and 12 as regards the chlorine atoms. The results of cesium atom coordination sphere examination by the crossing spheres method are presented. Metal-metal interactions (including Cs-Cs) in the structure of certain chlorides are revealed

  14. Adsorption of Cs(I), Sr(II), Eu(III), Co(II) and Cd(II) by Al2O3

    International Nuclear Information System (INIS)

    Shiao, S.Y.; Egozy, Y.; Meyer, R.E.

    1981-01-01

    Adsorption of Cs(I), Sr(II), Eu(III), Co(II) and Cd(II) by Al 2 O 3 was carried out over a wide range of NaCl concentration and solution pH. In the medium pH region (pH 5 to 9), adsorption depends strongly on pH and less on salt concentration. However, in the high pH region (pH above 9), the salt dependence of the distribution coefficient becomes important. (author)

  15. Crystal structures of MBi{sub 2}Br{sub 7} (M = Rb, Cs) - filled variants of AX{sub 7} sphere packing

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jen-Hui; Wolff, Alexander [Fachrichtung Chemie und Lebensmittelchemie, Technische Universitaet Dresden, 01062 Dresden (Germany); Ruck, Michael [Fachrichtung Chemie und Lebensmittelchemie, Technische Universitaet Dresden, 01062 Dresden (Germany); Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Str. 40, 01187 Dresden (Germany)

    2016-03-15

    The reinvestigation of the pseudo-binary systems MBr-BiBr{sub 3} (M = Rb, Cs) revealed two new phases with composition MBi{sub 2}Br{sub 7}. Both compounds are hygroscopic and show brilliant yellow color. The crystal structures were solved from X-ray single crystal diffraction data. The isostructural compounds adopt a new structure type in the triclinic space group P anti 1. The lattice parameters are a = 755.68(3) pm, b = 952.56(3) pm, c = 1044.00(4) pm, α = 76.400(2) , β = 84.590(2) , γ = 76.652(2) for RbBi{sub 2}Br{sub 7} and a = 758.71(5) pm, b = 958.23(7) pm, c = 1060.24(7) pm, α = 76.194(3) , β = 83.844(4) , γ = 76.338(3) for CsBi{sub 2}Br{sub 7}. The crystal structures consist of M{sup +} cations in anticuboctahedral coordination by bromide ions and bromidobismuthate(III) layers {sup 2}{sub ∞}[Bi{sub 2}Br{sub 7}]{sup -}. The 2D layers comprise pairs of BiBr{sub 6} octahedra sharing a common edge. The Bi{sub 2}Br{sub 10} double octahedra are further connected by common vertices. The bismuth(III) atoms increase their mutual distance in the double octahedra by off-centering so that the BiBr{sub 6} octahedra are distorted. The CsBi{sub 2}Br{sub 7} type can be interpreted as a common hexagonal close sphere packing of M and Br atoms, in which 1/4 of the octahedral voids are filled by Bi atoms. The structure type was systematically analyzed and compared with alternative types of common packings. The existence of a compound with the suggested composition CsBiBr{sub 4} could not be verified experimentally. (Copyright copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Bi-Provincial Upgrader

    International Nuclear Information System (INIS)

    1997-01-01

    Husky Oil's Bi-Provincial Upgrader is located in the rural municipality of Wilton, east of Lloydminster, Saskatchewan. It is jointly owned by Husky Oil and the Saskatchewan government. The upgrader is designed to produce 7.300 m 3 /cd of synthetic crude from 8.440 m 3 /cd of diluted Lloyd blend and distillates from the existing Lloydminster refinery. The designed coke and sulphur production is 415 t/day and 240 t/day respectively. Chronology of the Bi-Provincial Upgrader project was presented, along with details of the heavy oil feedstock properties for Cold Lake, Lloydminster and Lloyd Blend. Upgrader production history since start-up, synthetic crude oil customers, and the evolution of prices for Edmonton light vs. Husky LLB at Hardisty were also reviewed. 3 tabs., 9 figs

  17. Structural, elastic, electronic and optical properties of bi-alkali ...

    Indian Academy of Sciences (India)

    The structural parameters, elastic constants, electronic and optical properties of the bi-alkali ... and efficient method for the calculation of the ground-state ... Figure 2. Optimization curve (E–V) of the bi-alkali antimonides: (a) Na2KSb, (b) Na2RbSb, (c) Na2CsSb, .... ical shape of the charge distributions in the contour plots.

  18. A teleost CD46 is involved in the regulation of complement activation and pathogen infection.

    Science.gov (United States)

    Li, Mo-Fei; Sui, Zhi-Hai; Sun, Li

    2017-11-03

    In mammals, CD46 is involved in the inactivation of complement by factor I (FI). In teleost, study on the function of CD46 is very limited. In this study, we examined the immunological property of a CD46 molecule (CsCD46) from tongue sole, a teleost species with important economic value. We found that recombinant CsCD46 (rCsCD46) interacted with FI and inhibited complement activation in an FI-dependent manner. rCsCD46 also interacted with bacterial pathogens via a different mechanism to that responsible for the FI interaction, involving different rCsCD46 sites. Cellular study showed that CsCD46 was expressed on peripheral blood leukocytes (PBL) and protected the cells against the killing effect of complement. When the CsCD46 on PBL was blocked by antibody before incubation of the cells with bacterial pathogens, cellular infection was significantly reduced. Consistently, when tongue sole were infected with bacterial pathogens in the presence of rCsCD46, tissue dissemination and survival of the pathogens were significantly inhibited. These results provide the first evidence to indicate that CD46 in teleosts negatively regulates complement activation via FI and protects host cells from complement-induced damage, and that CD46 is required for optimal bacterial infection probably by serving as a receptor for the bacteria.

  19. Antiviral Activity of HIV gp120 Targeting Bispecific T Cell Engager (BiTE®) Antibody Constructs.

    Science.gov (United States)

    Brozy, Johannes; Schlaepfer, Erika; Mueller, Christina K S; Rochat, Mary-Aude; Rampini, Silvana K; Myburgh, Renier; Raum, Tobias; Kufer, Peter; Baeuerle, Patrick A; Muenz, Markus; Speck, Roberto F

    2018-05-02

    Today's gold standard in HIV therapy is the combined antiretroviral therapy (cART). It requires strict adherence by patients and life-long medication, which can lower the viral load below detection limits and prevent HIV-associated immunodeficiency, but cannot cure patients. The bispecific T cell engaging (BiTE®) antibody technology has demonstrated long-term relapse-free outcomes in patients with relapsed and refractory acute lymphocytic leukemia. We here generated BiTE® antibody constructs that target the HIV-1 envelope protein gp120 (HIV gp120) using either the scFv B12 or VRC01, the first two extracellular domains (1+2) of human CD4 alone or joined to the single chain variable fragment (scFv) of the antibody 17b fused to an anti-human CD3ϵ scFv. These engineered human BiTE® antibody constructs showed engagement of T cells for redirected lysis of HIV gp120-transfected CHO cells. Furthermore, they substantially inhibited HIV-1 replication in PBMCs as well as in macrophages co-cultured with autologous CD8+ T-cells, the most potent being the human CD4(1+2) BiTE® antibody construct and the CD4(1+2)L17b BiTE® antibody construct. The CD4(1+2) h BiTE® antibody construct promoted HIV infection of human CD4-/CD8+ T cells. In contrast, the neutralizing B12 and the VRC01 BiTE® antibody constructs as well as the CD4(1+2)L17b BiTE® antibody construct did not. Thus, BiTE® antibody constructs targeting HIV gp120 are very promising for constraining HIV and warrant further development as novel antiviral therapy with curative potential. Importance HIV is a chronic infection well controlled with the current cART. However, we lack cure of HIV, and the HIV pandemic goes on. Here we showed in vitro and ex vivo t hat a bispecific T-cell engaging (BiTE®) antibody construct targeting HIV gp120 resulted in substantially reduced HIV replication. In addition, these BiTE® antibody constructs display efficient killing of gp120 expressing cells and inhibited replication in ex vivo

  20. Nano-hydroxyapatite/β-CD/chitosan nanocomposite for potential applications in bone tissue engineering.

    Science.gov (United States)

    Shakir, Mohammad; Jolly, Reshma; Khan, Mohd Shoeb; Rauf, Ahmar; Kazmi, Shadab

    2016-12-01

    Herein, we report the synthesis of a novel tri-component nanocomposite system incorporating β-cyclodextrin (β-CD) with nano-hydroxyapatite (n-HA) and chitosan (CS), (n-HA/β-CD/CS) at three different temperatures via co-precipitation method. The chemical interactions and surface morphology have been evaluated by TEM, SEM and AFM techniques revealing the agglomerated nanoparticles in CS/n-HA-HA binary system whereas the ternary systems produced needle shaped nanoparticles dispersed homogeneously at low temperature with more porous and rougher surface. The addition of β-CD in CS/n-HA at low temperature decreased the particle size and raised the thermal stability as compared to CS/n-HA. The comparative hemolytic, protein adsorption and platelet adhesion studies confirmed the better hemocompatibility of n-HA/β-CD/CS-(RT,HT,LT) nanocomposites relative to CS/n-HA. The cell viability has been evaluated in vitro using MG-63 cell line which revealed superior non toxicity of n-HA/β-CD/CS-LT nanocomposite in comparison to n-HA/β-CD/CS-(RT,HT) and CS/n-HA nanocomposites. Thus it may be concluded that the orchestrated organic/inorganic n-HA/β-CD/CS-(RT,HT,LT) nanocomposites exhibited relatively higher cell viability of human osteoblast cells, stimulated greater osteogenesis, controlled biodegradation, enhanced antibacterial activity with excellent in-vitro biomineralization and remarkable mechanical parameters as compared to CS/n-HA nanocomposite and thus may provide opportunities for potential use as an alternative biomaterial for Bone tissue engineering applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Measurement of thermal neutron cross section and resonance integral of the reaction {sup 135}Cs(n,{gamma}){sup 136}Cs

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Toshio; Nakamura, Shoji; Harada, Hideo [Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan); Hatsukawa, Yuichi; Shinohara, Nobuo; Hata, Kentaro; Kobayashi, Katsutoshi; Motoishi, Shoji; Tanase, Masakazu

    1997-03-01

    The thermal neutron(2,200 m/s neutron) capture cross section({sigma}{sub 0}) and the resonance integral(I{sub 0}) of the reaction {sup 135}Cs(n,{gamma}){sup 136}Cs were measured by an activation method. Targets of radioactive cesium, which include {sup 135}Cs, {sup 137}Cs and stable {sup 133}Cs, were irradiated with reactor neutrons within or without a Cd shield case. The ratio of the number of nuclei of {sup 135}Cs to that of {sup 137}Cs was measured with a quadrupole mass spectrometer. This ratio and the ratio of activity of {sup 136}Cs to that of {sup 137}Cs were used for deduction of the {sigma}{sub 0} and the I{sub 0} of {sup 135}Cs. The {sigma}{sub 0} and the I{sub 0} of the reaction {sup 135}Cs(n,{sigma}){sup 136}Cs were 8.3 {+-} 0.3 barn and 38.1 {+-} 2.6 barn, respectively. (author)

  2. Microstructure of absorber layers in CdTe/CdS solar cells

    International Nuclear Information System (INIS)

    Cousins, M.A.

    2001-04-01

    This work concerns the microstructure of CSS-grown CdTe layers used for CdTe/CdS solar cells. Particular attention is given to how the development of microstructure on annealing with CdCl 2 may correlate with increases in efficiency. By annealing pressed pellets of bulk CdTe powder, it is shown that microstructural change does occur on heating the material, enhanced by the inclusion of CdCl 2 flux. However, the temperature required to cause significant effects is demonstrated to be higher than that at which heavy oxidation takes place. The dynamics of this oxidation are also examined. To investigate microstructural evolution in thin-films of CdTe, bi-layers of CdTe and CdS are examined by bevelling, thus revealing the microstructure to within ∼1 μm of the interface. This allows optical microscopy and subsequent image analysis of grain structure. The work shows that the grain-size, which is well described by the Rayleigh distribution, varies linearly throughout the layer, but is invariant under CdCl 2 treatment. Electrical measurements on these bi-layers, however, showed increased efficiency, as is widely reported. This demonstrates that the efficiency of these devices is not dictated by the bulk microstructure. Further, the region within 1 μm of the interface, of similar bi-layers to above, is examined by plan-view TEM. This reveals five-fold grain-growth on CdCl 2 treatment. Moreover, these grains show a considerably smaller grain size than expected from extrapolating the linear trend in the bulk. These observations are explained in terms of the pinning of the CdTe grain size to the underlying CdS, and the small grain size this causes. A simple model was proposed for a link between the grain-growth to the efficiency improvement. The study also examines the behaviour of defects within grains upon CdCl 2 treatment provided the first direct evidence of recovery on CdCl 2 treatment in this system. Finally, a computer model is presented to describe the evolution of

  3. Applicability of a portable CdTe and NaI (Tl) spectrometer for activity measure; Aplicabilidade de um espectrometro portatil de CdTe e NaI (Tl) para a medida da atividade de Cesio-137 ({sup 137}Cs) e Berilio-7 ({sup 7}Be)

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Jaquiel Salvi

    2005-02-15

    In this work it was studied the application of an in situ gamma spectrometer (ROVER) of Amptek Inc., composed by a Cadmium Telluride detector (CdTe) of 3 mm x 3 mm x 1 mm and a 30 mm x 30 mm Sodium Iodide detector doped with Thallium [NaI (Tl)). The radioactive sources used were type pastille, sealed in aluminum and polyethylene, of {sup 241}Am, {sup 133}Ba, {sup 152}Eu, 3 sources of {sup 137}Cs and soil samples contaminated with {sup 137}Cs. It was performed a factorial planning 2{sup 3} to optimize the in situ spectrometry system. This way it was determined that the best temperature for CdTe crystal operation is -22, deg C, with Shaping Time of 3 {mu}S and Rise Time Discrimination (RTD) with value 3. With the help of the certified radioactive sources, we determined the efficiency curve of the two detectors. The CdTe detector was positioned at the standard distance of 1 meter of the sources and also at 4.15 cm. The NaI (Tl) detector was also positioned at the standard distance of 1 meter of the sources and at 2.8 cm. Measures were performed to determine the Minimum Detectable Activity (MDA) for both detectors. For the pastille type sources, the {sup 137}Cs MDA for the CdTe detector at 4.15 cm, analyzing the energy line of 32 keV, was 6 kBq and at 1 meter of the {sup 137}Cs source, analyzing the line of 661.65 keV, the MDA was 67 kBq. For soil samples, CdTe detector at 4.15 cm presented a MDA of 693 kBq.kg-l for the line of 32 keV, and for the soil sample {sup 7}Be content the MDA found was 2867 Bq.kg{sup -1} at 4.15 cm. For the NaI (Tl) detector, analyzing the line of 661.65 keV, the {sup 137}Cs MDA for pastille type source at 1 meter of distance was 7 kBq, and for soil sample at 2.8 cm the measured {sup 137}Cs MDA was 71 Bq.kg{sup -1}. For the soil sample {sup 7}Be content, at 2.8 cm of the Nal (Tl) detector, the obtained MDA was 91 Bq.kg{sup -1}. Due to the minimum detectable activities found for the two detectors, we concluded that the employed in situ gamma

  4. In Vitro comparison of 213Bi- and 177Lu-radiation for peptide receptor radionuclide therapy.

    Science.gov (United States)

    Chan, Ho Sze; de Blois, Erik; Morgenstern, Alfred; Bruchertseifer, Frank; de Jong, Marion; Breeman, Wouter; Konijnenberg, Mark

    2017-01-01

    Absorbed doses for α-emitters are different from those for β-emitters, as the high linear energy transfer (LET) nature of α-particles results in a very dense energy deposition over a relatively short path length near the point of emission. This highly localized and therefore high energy deposition can lead to enhanced cell-killing effects at absorbed doses that are non-lethal in low-LET type of exposure. Affinities of DOTA-DPhe1-Tyr3-octreotate (DOTATATE), 115In-DOTATATE, 175Lu-DOTATATE and 209Bi-DOTATATE were determined in the K562-SST2 cell line. Two other cell lines were used for radiation response assessment; BON and CA20948, with a low and high expression of somatostatin receptors, respectively. Cellular uptake kinetics of 111In-DOTATATE were determined in CA20948 cells. CA20948 and BON were irradiated with 137Cs, 177Lu-DTPA, 177Lu-DOTATATE, 213Bi-DTPA and 213Bi-DOTATATE. Absorbed doses were calculated using the MIRDcell dosimetry method for the specific binding and a Monte Carlo model of a cylindrical 6-well plate geometry for the exposure by the radioactive incubation medium. Absorbed doses were compared to conventional irradiation of cells with 137Cs and the relative biological effect (RBE) at 10% survival was calculated. IC50 of (labelled) DOTATATE was in the nM range. Absorbed doses up to 7 Gy were obtained by 5.2 MBq 213Bi-DOTATATE, in majority the dose was caused by α-particle radiation. Cellular internalization determined with 111In-DOTATATE showed a linear relation with incubation time. Cell survival after exposure of 213Bi-DTPA and 213Bi-DOTATATE to BON or CA20948 cells showed a linear-exponential relation with the absorbed dose, confirming the high LET character of 213Bi. The survival of CA20948 after exposure to 177Lu-DOTATATE and the reference 137Cs irradiation showed the typical curvature of the linear-quadratic model. 10% Cell survival of CA20948 was reached at 3 Gy with 213Bi-DOTATATE, a factor 6 lower than the 18 Gy found for 177Lu

  5. In Vitro comparison of 213Bi- and 177Lu-radiation for peptide receptor radionuclide therapy.

    Directory of Open Access Journals (Sweden)

    Ho Sze Chan

    Full Text Available Absorbed doses for α-emitters are different from those for β-emitters, as the high linear energy transfer (LET nature of α-particles results in a very dense energy deposition over a relatively short path length near the point of emission. This highly localized and therefore high energy deposition can lead to enhanced cell-killing effects at absorbed doses that are non-lethal in low-LET type of exposure. Affinities of DOTA-DPhe1-Tyr3-octreotate (DOTATATE, 115In-DOTATATE, 175Lu-DOTATATE and 209Bi-DOTATATE were determined in the K562-SST2 cell line. Two other cell lines were used for radiation response assessment; BON and CA20948, with a low and high expression of somatostatin receptors, respectively. Cellular uptake kinetics of 111In-DOTATATE were determined in CA20948 cells. CA20948 and BON were irradiated with 137Cs, 177Lu-DTPA, 177Lu-DOTATATE, 213Bi-DTPA and 213Bi-DOTATATE. Absorbed doses were calculated using the MIRDcell dosimetry method for the specific binding and a Monte Carlo model of a cylindrical 6-well plate geometry for the exposure by the radioactive incubation medium. Absorbed doses were compared to conventional irradiation of cells with 137Cs and the relative biological effect (RBE at 10% survival was calculated.IC50 of (labelled DOTATATE was in the nM range. Absorbed doses up to 7 Gy were obtained by 5.2 MBq 213Bi-DOTATATE, in majority the dose was caused by α-particle radiation. Cellular internalization determined with 111In-DOTATATE showed a linear relation with incubation time. Cell survival after exposure of 213Bi-DTPA and 213Bi-DOTATATE to BON or CA20948 cells showed a linear-exponential relation with the absorbed dose, confirming the high LET character of 213Bi. The survival of CA20948 after exposure to 177Lu-DOTATATE and the reference 137Cs irradiation showed the typical curvature of the linear-quadratic model. 10% Cell survival of CA20948 was reached at 3 Gy with 213Bi-DOTATATE, a factor 6 lower than the 18 Gy found

  6. Phase equilibria and P-T-X(Fe-Mg relations involving Gl-St-Cd-Als-Bi-Mu-Oz-Kfs-H2O in medium-high grade metapelites (KFASH, KMASH and KFMASH sistems

    Directory of Open Access Journals (Sweden)

    Martínez, F. J.

    1989-12-01

    Full Text Available In different areas of the Hercynian in the Iberian Peninsula some reactions are repeatedly observed in pelites, these reactions are: Staurolite + muscovite + quartz = Biotite+ Al2SiO5+ H2O Garnet + muscovite = Al2SiO5+ biotite+ quartzBiotite + Al2SiO5 + quartz = Cordierite + K feldspar+Hp In order to examinate the P-T stability fields of these, and other similar reactions, aH the univariant equilibria in multisystems with Gt-Cd-St-Bi-Mu-Als-Qz-HP, Gt-St-Bi-Mu-Fk-AIs-QzHp and Cd-St-Bi-Mu-Fk-AIs-Qz-H2O in Kp-FeO-AI2O r SiO2-H2O (KFASH system have been calculated, and their corresponding P-T grids have been constructed. The expansion of these reactions into divariant surfaces through the P-T-X (Fe-Mg space was made by studying the assemblage Gt-Cd-St-Bi-Mu-Fk-AIs-Qz-HP in K2O-FeO-MgO-Al2O3-SiO2-H2O (KFMASH with a Fe/Fe+Mg relationship Gt > St > Bi > Cd such as observed in most of natural pelites. A resultant grid was obtained by combining those obtained in the aboye systerns. This grid has been P-T located for PH20 = P19 near QFM buffer, and excess muscovite and quartz conditions Reaction slopes in this grid were calculated within different P-T surroundings from thermodynamic data as weH as by considering the existing experimental data. In addition to the stability fields of reactions the P-T-XFe-Mg theoric relations for three univariant and thirteen divariant reactions have been obtained. The grid confirms the imposibility of staurolite-K feldspar and Garnet-Cordierite-Muscovite coexistence, as weH as the extension of the stability fields for Garnet-Staurolite, Cordierite-Staurolite and Garnet-Cordierite assemblages in muscovite-poor metapelites.En rocas metapelíticas de diversas áreas en el Hercínico de la Península Ibérica se observan a menudo las siguientes reacciones: Estaurolita + moscovita + cuarzo = biotita + Al2SiO5+ H2OGranate + moscovita = Al2SiO5 + biotita ± cuarzo Biotita + Al2SiO5 + cuarzo = cordierita + feldespato pot

  7. Effekte des oxidativen Stresses auf die Expression der Scavenger-Rezeptoren CD36 und SR-BI und des Transkriptionsfaktors PPARγ in Makrophagen

    OpenAIRE

    Westendorf, Thomas

    2006-01-01

    Ziel dieser Dissertationsschrift war es, die Effekte des oxidativen Stresses in Form von oxLDL auf die Expression der atherogenen Scavenger-Rezeptoren CD36, SR-BI, des Transkriptionsfaktors PPARγ und pro-inflammatorischer Zytokine zu untersuchen. Die durchgeführten Untersuchungen beruhen auf der Annahme, dass modifizierte LDL durch Induktion der genannten Scavenger-Rezeptoren und nachfolgende unregulierte Aufnahme in Makrophagen mit Bildung von Schaumzellen entscheidend zur Entwicklung einer ...

  8. Biting back: BiTE antibodies as a promising therapy for acute myeloid leukemia.

    Science.gov (United States)

    Walter, Roland B

    2014-06-01

    The experience with gemtuzumab ozogamicin has highlighted both the potential value and limitations of antibodies in acute myeloid leukemia (AML). Recently, bispecific T-cell engager (BiTE) antibodies have emerged as a means to harness polyclonal cytotoxic T-cells and cause highly efficient lysis of targeted tumor cells. Promising early results have been obtained with the CD19-directed BiTE antibody, blinatumomab, in patients with acute lymphoblastic leukemia. A first candidate for AML is the CD33/CD3 molecule, AMG 330, for which several recent preclinical studies demonstrated high potency and efficacy in destroying CD33(+) human AML cells. Many questions remain to be addressed, but BiTE antibodies may offer an exciting new tool in a disease for which the outcomes in many patients remain unsatisfactory.

  9. Quantitative Cs-137 distributions from airborne gamma ray data

    International Nuclear Information System (INIS)

    Oberlercher, G.; Seiberl, W.

    1997-01-01

    The Chernobyl reactor accident caused in Austria Cs-137 activities up to 180 kBq/m 2 . The following paper explains how airborne NaJ-spectroscopy, originally designed for geological surveys, was used as an accurate method to obtain the ground activity of Cs-137 in certain regions of Austria. To retrieve the net count rate in a Cs-137 window it is necessary to subtract all background contributions from the peak, including the Compton continuum and the contribution of overlapping peaks. Therefore the measurement of Cs-137 with a NaJ detector system must take into account radioactive elements with gamma-ray lines near the peak energy of Cs-137 at 662 keV. In regions with higher concentrations of the natural radioactive elements uranium and thorium a peak near 600 keV is found, containing the 609 keV line of Bi-214 and the 585 keV line of TI-208. Additionally a Cs-134 line is located at 604 keV. Because of the poor energy resolution of NaJ detectors it is not possible to find a clear separation between these peaks and the Cs-137 peak. The following section describes the method that was used to obtain accurate quantified Cs-137 activity values. (author)

  10. First-principles study of electronic and optical properties of lead-free double perovskites Cs2NaBX6 (B = Sb, Bi; X = Cl, Br, I)

    Science.gov (United States)

    Zhao, Shuai; Yamamoto, Kumiko; Iikubo, Satoshi; Hayase, Shuzi; Ma, Tingli

    2018-06-01

    Organolead halide perovskite is regarded as the most promising light-harvesting material for next-generation solar cells; however, the intrinsic instability and toxicity of lead are still of great concern. Bismuth is ecofriendly and has electronic properties similar to those of lead, which has gradually attracted interest for optoelectronic applications. However, the valence state of bismuth is different from that of lead, eliminating the possibility of replacing lead by bismuth in organolead halide perovskites. To address this matter, one feasible strategy is to construct B-site double perovskites by the combination of Bi3+ and B+ in 1:1 ratio. In this work, lead-free halide double perovskites of the form Cs2NaBX6 (B = Sb, Bi; X = Cl, Br, I) were investigated by first-principles calculations. The electronic properties, optical absorption coefficients, and thermodynamic stability of these compounds were investigated to ascertain their potential application in solar energy conversion. The results provide theoretical support for the exploration of lead-free perovskite materials in potential optoelectronic applications.

  11. A note on {sup 207}Bi in environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Bossew, P. [European Commission, DG Joint Research Centre, Institute of Environment and Sustainability, Radioactivity Environmental Monitoring Group. Via Fermi 1, I-21020 Ispra, Vatican City State, Holy See (Italy)]. E-mail: peter.bossew@jrc.it; Lettner, H. [Institute of Physics and Biophysics, University of Salzburg, Hellbrunner Strasse 34, A-5020 Salzburg (Austria)]. E-mail: herbert.lettner@sbg.ac.at; Hubmer, A. [Institute of Physics and Biophysics, University of Salzburg, Hellbrunner Strasse 34, A-5020 Salzburg (Austria)

    2006-07-01

    Traces of the radionuclide {sup 207}Bi were identified in soil and cryoconite (glacier sediment) samples from Alpine regions of Austria. This nuclide has been produced in thermonuclear explosions mainly in the early 1960s and subsequently dispersed in the atmosphere. Activity concentrations up to 22 Bq/kg d.m. have been found. The ratio {sup 207}Bi:{sup 137}Cs(global fallout) equals (1.70 {+-} 0.12)10{sup -3}, which is in accordance with literature data. When low levels of {sup 207}Bi are assessed by gamma spectrometry, corrections must be made for a gamma line produced in the lead shield by neutron activation due to cosmic neutrons.

  12. Direct Quantification of Cd2+ in the Presence of Cu2+ by a Combination of Anodic Stripping Voltammetry Using a Bi-Film-Modified Glassy Carbon Electrode and an Artificial Neural Network.

    Science.gov (United States)

    Zhao, Guo; Wang, Hui; Liu, Gang

    2017-07-03

    Abstract : In this study, a novel method based on a Bi/glassy carbon electrode (Bi/GCE) for quantitatively and directly detecting Cd 2+ in the presence of Cu 2+ without further electrode modifications by combining square-wave anodic stripping voltammetry (SWASV) and a back-propagation artificial neural network (BP-ANN) has been proposed. The influence of the Cu 2+ concentration on the stripping response to Cd 2+ was studied. In addition, the effect of the ferrocyanide concentration on the SWASV detection of Cd 2+ in the presence of Cu 2+ was investigated. A BP-ANN with two inputs and one output was used to establish the nonlinear relationship between the concentration of Cd 2+ and the stripping peak currents of Cu 2+ and Cd 2+ . The factors affecting the SWASV detection of Cd 2+ and the key parameters of the BP-ANN were optimized. Moreover, the direct calibration model (i.e., adding 0.1 mM ferrocyanide before detection), the BP-ANN model and other prediction models were compared to verify the prediction performance of these models in terms of their mean absolute errors (MAEs), root mean square errors (RMSEs) and correlation coefficients. The BP-ANN model exhibited higher prediction accuracy than the direct calibration model and the other prediction models. Finally, the proposed method was used to detect Cd 2+ in soil samples with satisfactory results.

  13. Cucumber Metallothionein-Like 2 (CsMTL2 Exhibits Metal-Binding Properties

    Directory of Open Access Journals (Sweden)

    Yu Pan

    2016-11-01

    Full Text Available We identified a novel member of the metallothionein (MT family, Cucumis sativus metallothionein-like 2 (CsMTL2, by screening a young cucumber fruit complementary DNA (cDNA library. The CsMTL2 encodes a putative 77-amino acid Class II MT protein that contains two cysteine (Cys-rich domains separated by a Cys-free spacer region. We found that CsMTL2 expression was regulated by metal stress and was specifically induced by Cd2+ treatment. We investigated the metal-binding characteristics of CsMTL2 and its possible role in the homeostasis and/or detoxification of metals by heterologous overexpression in Escherichia coli cells. Furthermore, we produced a deletion mutant form of the protein, CsMTL2m, that contained the two Cys-rich clusters but lacked the spacer region, in E. coli. We compared the metal-binding properties of CsMTL2 with those of CsMTL2m, the β domain of human metallothionein-like protein 1 (HsMTXb, and phytochelatin-like (PCL heterologously expressed in E. coli using metal-binding assays. We found that E. coli cells expressing CsMTL2 accumulated the highest levels of Zn2+ and Cd2+ of the four transformed cell types, with levels being significantly higher than those of control cells containing empty vector. E. coli cells expressing CsMTL2 had a higher tolerance for cadmium than for zinc ions. These findings show that CsMTL2 improves metal tolerance when heterologously expressed in E. coli. Future studies should examine whether CsMTL2 improves metal tolerance in planta.

  14. T helper-independent activation of human CD8+ cells: the role of CD28 costimulation.

    Science.gov (United States)

    Van Gool, S W; Zhang, Y; Kasran, A; de Boer, M; Ceuppens, J L

    1996-07-01

    The concept that activation of MHC class I-restricted CD8+ cells entirely depends on help from MHC class II-restricted CD4+ T cells has recently been supplemented with an alternative model in which CD8+ cells can directly be activated by MHC class I-expressing professional antigen-presenting cells (APC), which are able to deliver an accessory signal. The authors analysed the role of CD28-mediated costimulation for T helper cell-independent activation of purified human CD8+ T cells in two different in vitro models. Freshly isolated CD8+ cells could be activated (proliferation, IL-2 production and cytotoxic activity) by anti-CD3-presenting Fc gamma R+ mouse cells transfected with the human CD28 ligand, CD80, as the only accessory signal. On the other hand, activation of CD8+ cells by allogeneic MHC class I on EBV-transformed B cells, which express two different CD28 ligands, CD80 and CD86, also proceeded very efficiently (proliferation, cytotoxic activity and CD25 expression), but was either not, or only partially, blocked by anti-CD80 and anti-CD86 MoAb or CTLA-4Ig. This indicates that other costimulatory signals are also effective, and that CD28 triggering is not absolutely required for initial T-cell activation. CsA and CD80/CD86-blocking agents were synergistic in completely inhibiting activation of CD8+ cells in the MLR with allogeneic B-cell lines. This combination also induced non-responsiveness of CD8+ cells upon restimulation in the absence of blocking agents. Therefore, although professional APC can apparently provide multiple costimulatory signals for direct activation of CD8+ T cells, the signal derived from CD80/CD86 is unique in providing CsA-resistance.

  15. Variability in uptake of Cs isotopes by fenugreek plant from three soils

    Energy Technology Data Exchange (ETDEWEB)

    Pulhani, V; Dafauti, S; Dahiya, S; Hedge, A G [Environmental Studies Section, Health Physics Div., Bhabha Atomic Research Centre, Mumbai (India)

    2008-07-01

    Soil to plant transfer via root uptake is one of the major compartments in the radionuclide transfer pathways to man and can be used to assess the internal radiation dose via ingestion. The variability in the Transfer Factor (TF) of Cs isotopes was investigated in three different soils from nuclear power plant sites at Rajasthan and Narora with alkaline sandy loam alluvial and Madras with acidic coastal sandy loam alluvial soil. The soils were characterized for soil properties like texture, pH, EC, organic carbon, CaCO{sub 3} (%), CEC, silt, clay sand etc. and spiked with a mixture of 800 Bq {sup 137}Cs, 300 Bq {sup 134}Cs and 10mg of {sup 133}Cs (stable). Fenugreek (Trigonella foenum-graecum L.) from Leguminosae family an annual plant commonly used as a vegetable was grown in these soils to study the uptake of Cs. The uptake of heavy toxic elements like Pb, Cd, Ni, Cr etc. and nutrients Fe, Co, Cu, Zn, Mn, Ca, Mg, Na and K was also studied. The uptake of heavy toxic elements like Pb, Cd, Ni, Cr etc. and nutrients Fe, Co, Cu, Zn, Mn, Ca, Mg, Na and K was also studied. {sup 137}Cs and{sup 134}Cs was estimated using HPGe detector (15% Relative Efficiency, 54cc-coaxial, 2keV resolution at 1332keV of {sup 60}Co). Stable Cs, K and Na were determined by the Atomic Emission Spectrophotometry and Pb, Cd, Cr etc. by Atomic Absorption Spectrophotometry. Among the three soils the transfer factor for all the elements and Cs was highest for MAPS due to higher organic matter content and acidic pH followed by NAPS and RAPS. The {sup 137}Cs and {sup 134}Cs isotopes have been taken up to the same extent from soil and transfer factors are similar to each other. But the stable Cs uptake appears to be slightly high, probably because of excess of {sup 133}Cs (mg level) added as compared to the radioactive isotopes. In spite of this high difference in the soil concentrations of Cs isotopes, uptake of {sup 133}Cs is not very high indicating to a physiological limiting process for uptake

  16. On the doping problem of CdTe films: The bismuth case

    Energy Technology Data Exchange (ETDEWEB)

    Vigil-Galan, O. [Escuela Superior de Fisica y Matematicas del IPN, Edif. 9, UPALM, 07738 Mexico, D. F. (Mexico); Brown, M. [Department of Physics and Astronomy, The University of Toledo, 43606 Toledo, OH (United States); Ruiz, C.M. [Depto. Fisica de Materiales, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Vidal-Borbolla, M.A. [Instituto de Investigacion en Comunicacion Optica, Av. Karakorum 1470, Lomas 4a. Secc., 78210 San Luis Potosi, SLP (Mexico); Ramirez-Bon, R. [CINVESTAV-IPN, U. Queretaro, Libramiento Norponiente No. 2000, Fracc. Real de Juriquilla, 76230 Santiago de Queretaro, Qro. (Mexico); Sanchez-Meza, E. [Escuela Superior de Fisica y Matematicas del IPN, Edif. 9, UPALM, 07738 Mexico, D. F. (Mexico); Tufino-Velazquez, M. [Escuela Superior de Fisica y Matematicas del IPN, Edif. 9, UPALM, 07738 Mexico, D. F. (Mexico)], E-mail: mtufinovel@yahoo.com.mx; Calixto, M. Estela [Escuela Superior de Fisica y Matematicas del IPN, Edif. 9, UPALM, 07738 Mexico, D. F. (Mexico); Compaan, A.D. [Department of Physics and Astronomy, The University of Toledo, 43606 Toledo, OH (United States); Contreras-Puente, G. [Escuela Superior de Fisica y Matematicas del IPN, Edif. 9, UPALM, 07738 Mexico, D. F. (Mexico)

    2008-08-30

    The controlled increase of hole concentration is an important issue and still an unsolved problem for polycrystalline CdTe-based solar cells. The typical hole concentration of as-grown CdTe thin-films goes up to 10{sup 13} cm{sup -3}, depending on the specific growth technique. The highest electron concentration obtained for CdS, the suitable window partner material of CdTe, is around 10{sup 15} cm{sup -3}. Thus, the PV-performance of a CdS/CdTe device can be optimized if the hole concentration in CdTe is increased. We have faced up this problem by studying the electrical properties of two types of CdTe films: CdTe films grown by Close Space Vapor Transport using a CdTe:Bi powder as the starting material and CdTe sputtered films doped by implantation with different Bi-doses. Temperature-dependent resistivity and Hall effect measurements and a discussion on the efficiency of both doping processes are presented.

  17. On the doping problem of CdTe films: The bismuth case

    International Nuclear Information System (INIS)

    Vigil-Galan, O.; Brown, M.; Ruiz, C.M.; Vidal-Borbolla, M.A.; Ramirez-Bon, R.; Sanchez-Meza, E.; Tufino-Velazquez, M.; Calixto, M. Estela; Compaan, A.D.; Contreras-Puente, G.

    2008-01-01

    The controlled increase of hole concentration is an important issue and still an unsolved problem for polycrystalline CdTe-based solar cells. The typical hole concentration of as-grown CdTe thin-films goes up to 10 13 cm -3 , depending on the specific growth technique. The highest electron concentration obtained for CdS, the suitable window partner material of CdTe, is around 10 15 cm -3 . Thus, the PV-performance of a CdS/CdTe device can be optimized if the hole concentration in CdTe is increased. We have faced up this problem by studying the electrical properties of two types of CdTe films: CdTe films grown by Close Space Vapor Transport using a CdTe:Bi powder as the starting material and CdTe sputtered films doped by implantation with different Bi-doses. Temperature-dependent resistivity and Hall effect measurements and a discussion on the efficiency of both doping processes are presented

  18. Enhanced photocatalytic activity of cadmium-doped Bi{sub 2}WO{sub 6} nanoparticles under simulated solar light

    Energy Technology Data Exchange (ETDEWEB)

    Song, Xu Chun, E-mail: songxuchunfj@163.com; Li, Wen Ting [Fujian Normal University, Department of Chemistry (China); Huang, Wan Zhen; Zhou, Huan [Zhejiang University of Technology, Research Center of Analysis and Measurement (China); Yin, Hao Yong [Hangzhou Dianzi University, Institute of Environmental Science and Engineering (China); Zheng, Yi Fan [Zhejiang University of Technology, Research Center of Analysis and Measurement (China)

    2015-03-15

    Novel cadmium-doped Bi{sub 2}WO{sub 6} nanoparticles with different Cd contents have been synthesized by a one-step route using ethylene glycol and water as solvents at 180 °C for 12 h. The as-synthesized samples were characterized in detailed by SEM, XRD, EDS, HRTEM, UV–Vis DRS, BET techniques, and so on. The results shown that with the increase of the Cd{sup 2+} addition, the crystal structure, lattice space, and absorption edge were not significantly changed and the calculated band gap value was 2.58 eV. However, the flower-like Bi{sub 2}WO{sub 6} sphere was gradually destroyed. Simultaneously, the surface area and photocurrent responses of the catalysts were greatly increased. Photocatalytic activity of the Cd-doped Bi{sub 2}WO{sub 6} samples was determined by monitoring the change of RhB concentration under simulated solar light. The results revealed that cadmium doping greatly improved the photocatalytic efficiency of Bi{sub 2}WO{sub 6}. The Bi{sub 2}WO{sub 6} sample with R{sub Cd} = 0.05 displayed the highest photocatalytic activity, and the degradation rate is about two times greater than pure Bi{sub 2}WO{sub 6}. Moreover, the Cd–Bi{sub 2}WO{sub 6} photocatalyst remained stable even after five consecutive cycles. A possible mechanism of photocatalytic activity enhancement on basis of the experimental results was proposed.

  19. Oral Salmonella: malaria circumsporozoite recombinants induce specific CD8+ cytotoxic T cells

    OpenAIRE

    1990-01-01

    Oral immunization with an attenuated Salmonella typhimurium recombinant containing the full-length Plasmodium berghei circumsporozoite (CS) gene induces protective immunity against P. berghei sporozoite challenge in the absence of antibody. We found that this immunity was mediated through the induction of specific CD8+ T cells since in vivo elimination of CD8+ cells abrogated protection. In vitro studies revealed that this Salmonella-P. berghei CS recombinant induced class I- restricted CD8+ ...

  20. Inhibition of HIV transmission in human cervicovaginal explants and humanized mice using CD4 aptamer-siRNA chimeras

    Science.gov (United States)

    Wheeler, Lee Adam; Trifonova, Radiana; Vrbanac, Vladimir; Basar, Emre; McKernan, Shannon; Xu, Zhan; Seung, Edward; Deruaz, Maud; Dudek, Tim; Einarsson, Jon Ivar; Yang, Linda; Allen, Todd M.; Luster, Andrew D.; Tager, Andrew M.; Dykxhoorn, Derek M.; Lieberman, Judy

    2011-01-01

    The continued spread of the HIV epidemic underscores the need to interrupt transmission. One attractive strategy is a topical vaginal microbicide. Sexual transmission of herpes simplex virus type 2 (HSV-2) in mice can be inhibited by intravaginal siRNA application. To overcome the challenges of knocking down gene expression in immune cells susceptible to HIV infection, we used chimeric RNAs composed of an aptamer fused to an siRNA for targeted gene knockdown in cells bearing an aptamer-binding receptor. Here, we showed that CD4 aptamer-siRNA chimeras (CD4-AsiCs) specifically suppress gene expression in CD4+ T cells and macrophages in vitro, in polarized cervicovaginal tissue explants, and in the female genital tract of humanized mice. CD4-AsiCs do not activate lymphocytes or stimulate innate immunity. CD4-AsiCs that knock down HIV genes and/or CCR5 inhibited HIV infection in vitro and in tissue explants. When applied intravaginally to humanized mice, CD4-AsiCs protected against HIV vaginal transmission. Thus, CD4-AsiCs could be used as the active ingredient of a microbicide to prevent HIV sexual transmission. PMID:21576818

  1. Bismuth zinc vanadate, BiZn2VO6: New crystal structure type and electronic structure

    International Nuclear Information System (INIS)

    Eliziario Nunes, Sayonara; Wang, Chun-Hai; So, Karwei; Evans, John S.O.; Evans, Ivana Radosavljević

    2015-01-01

    We report a combined experimental and computational study of the crystal structure and electronic properties of bismuth zinc vanadate, BiZn 2 VO 6 , known for its visible light photocatalytic activity. The crystal structure has been solved from laboratory powder X-ray diffraction data using the repeated minimisations from random starting values method. BiZn 2 VO 6 adopts a new structure type, based on the following building blocks: corner- and edge-sharing ZnO 4 tetrahedra, ZnO 6 octahedra and VO 4 tetrahedra, and Bi 2 O 12 dimers. It is the only known member of the BiM 2 AO 6 (M=Pb, Ca, Cd, Mn, Zn, Mg, Cu; A=V, P, As) family which does not appear to be structurally closely related to others. The electronic structure of BiZn 2 VO 6 , calculated by DFT methods, shows that it is an indirect gap semiconductor with a calculated band gap of 1.6 eV, which compares favourably to the experimentally measured value of 2.4 eV. - Graphical abstract: The crystal structure of BiZn 2 VO 6 , a new structure type in the BiM 2 AO 6 (M=Mg, Ca, Cd, Cu, Pb, Mn, Zn; A=V, P, As) family. - Highlights: • Structure solution from PXRD data by repeated minimisations from random starting values. • New structure type in the BiM 2 AO 6 (M=Pb, Ca, Cd, Mn, Zn, Mg, Cu; A=V, P, As) family. • Electronic structure calculation

  2. Effect of Low-Melting Metals (Pb, Bi, Cd, In) on the Structure, Phase Composition, and Properties of Casting Al-5% Si-4% Cu Alloy

    Science.gov (United States)

    Yakovleva, A. O.; Belov, N. A.; Bazlova, T. A.; Shkalei, I. V.

    2018-01-01

    The effect of low-melting metals (Pb, Bi, Cd, In) on the structure, phase composition, and properties of the Al-5% Si-4% Cu alloy was studied using calculations. Polythermal sections have been reported, which show that the considered systems are characterized by the presence of liquid regions and monotectic reactions. The effect of low-melting metals on the microstructure and hardening of base alloy in the cast and heat-treated states has been studied.

  3. Evaluation of the impact of chitosan/DNA nanoparticles on the differentiation of human naive CD4+ T cells

    Science.gov (United States)

    Liu, Lanxia; Bai, Yuanyuan; Zhu, Dunwan; Song, Liping; Wang, Hai; Dong, Xia; Zhang, Hailing; Leng, Xigang

    2011-06-01

    Chitosan (CS) is one of the most widely studied polymers in non-viral gene delivery since it is a cationic polysaccharide that forms nanoparticles with DNA and hence protects the DNA against digestion by DNase. However, the impact of CS/DNA nanoparticle on the immune system still remains poorly understood. Previous investigations did not found CS/DNA nanoparticles had any significant impact on the function of human and murine macrophages. To date, little is known about the interaction between CS/DNA nanoparticles and naive CD4+ T cells. This study was designed to investigate whether CS/DNA nanoparticles affect the initial differentiation direction of human naive CD4+ T cells. The indirect impact of CS/DNA nanoparticles on naive CD4+ T cell differentiation was investigated by incubating the nanoparticles with human macrophage THP-1 cells in one chamber of a transwell co-incubation system, with the enriched human naive CD4+ T cells being placed in the other chamber of the transwell. The nanoparticles were also co-incubated with the naive CD4+ T cells to explore their direct impact on naive CD4+ T cell differentiation by measuring the release of IL-4 and IFN-γ from the cells. It was demonstrated that CS/DNA nanoparticles induced slightly elevated production of IL-12 by THP-1 cells, possibly owing to the presence of CpG motifs in the plasmid. However, this macrophage stimulating activity was much less significant as compared with lipopolysaccharide and did not impact on the differentiation of the naive CD4+ T cells. It was also demonstrated that, when directly exposed to the naive CD4+ T cells, the nanoparticles induced neither the activation of the naive CD4+ T cells in the absence of recombinant cytokines (recombinant human IL-4 or IFN-γ) that induce naive CD4+ T cell polarization, nor any changes in the differentiation direction of naive CD4+ T cells in the presence of the corresponding cytokines.

  4. Evaluation of the impact of chitosan/DNA nanoparticles on the differentiation of human naive CD4+ T cells

    International Nuclear Information System (INIS)

    Liu Lanxia; Bai Yuanyuan; Zhu Dunwan; Song Liping; Wang Hai; Dong Xia; Zhang Hailing; Leng Xigang

    2011-01-01

    Chitosan (CS) is one of the most widely studied polymers in non-viral gene delivery since it is a cationic polysaccharide that forms nanoparticles with DNA and hence protects the DNA against digestion by DNase. However, the impact of CS/DNA nanoparticle on the immune system still remains poorly understood. Previous investigations did not found CS/DNA nanoparticles had any significant impact on the function of human and murine macrophages. To date, little is known about the interaction between CS/DNA nanoparticles and naive CD4 + T cells. This study was designed to investigate whether CS/DNA nanoparticles affect the initial differentiation direction of human naive CD4 + T cells. The indirect impact of CS/DNA nanoparticles on naive CD4 + T cell differentiation was investigated by incubating the nanoparticles with human macrophage THP-1 cells in one chamber of a transwell co-incubation system, with the enriched human naive CD4 + T cells being placed in the other chamber of the transwell. The nanoparticles were also co-incubated with the naive CD4 + T cells to explore their direct impact on naive CD4 + T cell differentiation by measuring the release of IL-4 and IFN-γ from the cells. It was demonstrated that CS/DNA nanoparticles induced slightly elevated production of IL-12 by THP-1 cells, possibly owing to the presence of CpG motifs in the plasmid. However, this macrophage stimulating activity was much less significant as compared with lipopolysaccharide and did not impact on the differentiation of the naive CD4 + T cells. It was also demonstrated that, when directly exposed to the naive CD4 + T cells, the nanoparticles induced neither the activation of the naive CD4 + T cells in the absence of recombinant cytokines (recombinant human IL-4 or IFN-γ) that induce naive CD4 + T cell polarization, nor any changes in the differentiation direction of naive CD4 + T cells in the presence of the corresponding cytokines.

  5. Aggravation of Allergic Airway Inflammation by Cigarette Smoke in Mice Is CD44-Dependent.

    Directory of Open Access Journals (Sweden)

    Smitha Kumar

    Full Text Available Although epidemiological studies reveal that cigarette smoke (CS facilitates the development and exacerbation of allergic asthma, these studies offer limited information on the mechanisms involved. The transmembrane glycoprotein CD44 is involved in cell adhesion and acts as a receptor for hyaluronic acid and osteopontin. We aimed to investigate the role of CD44 in a murine model of CS-facilitated allergic airway inflammation.Wild type (WT and CD44 knock-out (KO mice were exposed simultaneously to house dust mite (HDM extract and CS. Inflammatory cells, hyaluronic acid (HA and osteopontin (OPN levels were measured in bronchoalveolar lavage fluid (BALF. Proinflammatory mediators, goblet cell metaplasia and peribronchial eosinophilia were assessed in lung tissue. T-helper (Th 1, Th2 and Th17 cytokine production was evaluated in mediastinal lymph node cultures.In WT mice, combined HDM/CS exposure increased the number of inflammatory cells and the levels of HA and OPN in BALF and Th2 cytokine production in mediastinal lymph nodes compared to control groups exposed to phosphate buffered saline (PBS/CS, HDM/Air or PBS/Air. Furthermore, HDM/CS exposure significantly increased goblet cell metaplasia, peribronchial eosinophilia and inflammatory mediators in the lung. CD44 KO mice exposed to HDM/CS had significantly fewer inflammatory cells in BALF, an attenuated Th2 cytokine production, as well as decreased goblet cells and peribronchial eosinophils compared to WT mice. In contrast, the levels of inflammatory mediators were similar or higher than in WT mice.We demonstrate for the first time that the aggravation of pulmonary inflammation upon combined exposure to allergen and an environmental pollutant is CD44-dependent. Data from this murine model of concomitant exposure to CS and HDM might be of importance for smoking allergic asthmatics.

  6. Diffusion coefficients for Tl, Pb, Cd, In, Zn, Bi, As, Mo and Sb in hydrous rhyolite at 100-200 MPa

    Science.gov (United States)

    Berlo, Kim; Brooker, Richard; Wilke, Max

    2014-05-01

    A series of experiments have been conducted to determine the diffusivities of Tl, Pb, Cd, In, Zn, Bi, As, Mo and Sb in hydrous rhyolitic melt. Diffusion experiments used two adjoining glass cylinder of the same hydrous composition, one doped with the elements of interest at ~ 100 ppm. These couples were rapidly heated to 850, 1000 and 1150°C at 100-200 MPa for a few hours. After quenching the sectioned charges were analyzed by both synchrotron XRF (The Diamond Light Source) and LA-ICP-MS (University of Oxford). The data shows excellent correlation between these two techniques. The diffusion profiles were fitted to a 1-D diffusion couple equation to determine the diffusivities and fitting to the different temperature runs defined the Arrhenius parameters. We find that for 850°C the diffusion coefficients follow the trend Tl>Pb>Cd>Zn>In>Bi>As>Sb>Mo. Additional experiments were performed with either S or Cl added (to both sides of the diffusion couple). In general S increases the diffusion rate of all metals except Mo and Sb, which diffuse slower in the presence of S. Chlorine also speeds up the diffusion of metals with the exception of In, Mo and Sb. The systematic change in diffusivities of these metals and their different behaviour in the presence of the ligands that are also observed to be significant in volcanic gases, are important in determining the distribution of these metals during degassing (e.g. MacKenzie and Canil, 2008). This is particularly important in a dynamic environment such as a volcanic conduit. There are also implications for economic exploration and well as hazard mitigation.

  7. Evaluation of the impact of chitosan/DNA nanoparticles on the differentiation of human naive CD4{sup +} T cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu Lanxia; Bai Yuanyuan; Zhu Dunwan; Song Liping; Wang Hai; Dong Xia; Zhang Hailing; Leng Xigang, E-mail: lengxg@bme.org.cn [Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin Key Laboratory of Biomedical Materials, Lab of Bioengineering, Institute of Biomedical Engineering (China)

    2011-06-15

    Chitosan (CS) is one of the most widely studied polymers in non-viral gene delivery since it is a cationic polysaccharide that forms nanoparticles with DNA and hence protects the DNA against digestion by DNase. However, the impact of CS/DNA nanoparticle on the immune system still remains poorly understood. Previous investigations did not found CS/DNA nanoparticles had any significant impact on the function of human and murine macrophages. To date, little is known about the interaction between CS/DNA nanoparticles and naive CD4{sup +} T cells. This study was designed to investigate whether CS/DNA nanoparticles affect the initial differentiation direction of human naive CD4{sup +} T cells. The indirect impact of CS/DNA nanoparticles on naive CD4{sup +} T cell differentiation was investigated by incubating the nanoparticles with human macrophage THP-1 cells in one chamber of a transwell co-incubation system, with the enriched human naive CD4{sup +} T cells being placed in the other chamber of the transwell. The nanoparticles were also co-incubated with the naive CD4{sup +} T cells to explore their direct impact on naive CD4{sup +} T cell differentiation by measuring the release of IL-4 and IFN-{gamma} from the cells. It was demonstrated that CS/DNA nanoparticles induced slightly elevated production of IL-12 by THP-1 cells, possibly owing to the presence of CpG motifs in the plasmid. However, this macrophage stimulating activity was much less significant as compared with lipopolysaccharide and did not impact on the differentiation of the naive CD4{sup +} T cells. It was also demonstrated that, when directly exposed to the naive CD4{sup +} T cells, the nanoparticles induced neither the activation of the naive CD4{sup +} T cells in the absence of recombinant cytokines (recombinant human IL-4 or IFN-{gamma}) that induce naive CD4{sup +} T cell polarization, nor any changes in the differentiation direction of naive CD4{sup +} T cells in the presence of the corresponding

  8. Determination of the f and alpha parameters in the neutron multiplier CS-ISCTN

    International Nuclear Information System (INIS)

    Hernandez, O.; Ixquiac, M.; Contreras, R.; Herrera, E.; Diaz, O.; Lopez, R.; Alvarez, P.; Manso, M.V.; Padron, G.; D Alessandro, K.

    1997-01-01

    The values of the f and alpha parameters are determined in the irradiation position of the neutron multiplier CS-ISCTN, with the aim to show the possibility to applied the parametric neutron activation analysis. The more used conventions to calculate the reaction rate; Hogdhal, Modified Stoughton-Halpering and Modified Wescott, the last is presents with some new variations. This comparison is combined with R-Cd multi monitors method, Cd-Cover Multi monitor Methods and a new method introduced in the present paper to reduce the errors in the alpha parameter determination named Minimal Difference Method. This last method show better results, according to the epithermal hardeners of the CS-ISCT

  9. Sensitive stripping voltammetric determination of Cd(II) and Pb(II) by a Bi/multi-walled carbon nanotube-emeraldine base polyaniline-Nafion composite modified glassy carbon electrode

    International Nuclear Information System (INIS)

    Zhao, Guo; Yin, Yuan; Wang, Hui; Liu, Gang; Wang, Zhiqiang

    2016-01-01

    Highlights: • A MWCNT-EBP-NA composite film modified GCE was fabricated and characterized. • The GCE modified with the MWCNT-EBP-NA composite film exhibited excellent performance in the analysis of Cd(II) and Pb(II) by SWASV. • The Cd(II) and Pb(II) detection limits of the developed electrode were approximately 0.06 μg/L and 0.08 μg/L, respectively. • Bi/MWCNT-EBP-NA/GCE was successfully used to determine metal ions in soil samples. - Abstract: In this study, a multi-walled carbon nanotube (MWCNT)-emeraldine base polyaniline (EBP)-Nafion (NA) composite modified glassy carbon electrode (MWCNT-EBP-NA/GCE) was prepared and used for the sensitive detection of trace Pb(II) and Cd(II), with a detection limit of 0.06 μg/L for Cd(II) and 0.08 μg/L for Pb(II) (S/N = 3), by square wave anodic stripping voltammetry (SWASV). A bismuth film was prepared through the in situ plating of bismuth on the MWCNT-EBP-NA/GCE. The morphologies and electrochemical properties of the modified electrode were characterized by SWASV, scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The parameters affecting the stripping current response were investigated and optimized. The formed MWCNTs in the composite film enlarged the specific surface area of the electrode and significantly promoted electron transferring, and the formed polyaniline (PANI) enhanced the ion-exchange capacity and prevented the macromolecules in real samples from absorbing onto the surface of the electrode. The presence of NA effectively increased the stability and adhesion of the composite film, enhanced the cation-exchange capacity and improved the ability to preconcentrate metal ions. Under the optimized conditions, a linear range of 1.0 to 50.0 μg/L was achieved for both metal ions, with a detection limit of 0.06 μg/L for Cd(II) and 0.08 μg/L for Pb(II) (S/N = 3), offering good repeatability. Finally, the Bi/MWCNT-EBP-NA/GCE was used for the

  10. Quality Assurance on Undoped CsI Crystals for the Mu2e Experiment

    Science.gov (United States)

    Atanov, N.; Baranov, V.; Budagov, J.; Davydov, Yu. I.; Glagolev, V.; Tereshchenko, V.; Usubov, Z.; Cervelli, F.; Di Falco, S.; Donati, S.; Morescalchi, L.; Pedreschi, E.; Pezzullo, G.; Raffaelli, F.; Spinella, F.; Colao, F.; Cordelli, M.; Corradi, G.; Diociaiuti, E.; Donghia, R.; Giovannella, S.; Happacher, F.; Martini, M.; Miscetti, S.; Ricci, M.; Saputi, A.; Sarra, I.; Echenard, B.; Hitlin, D. G.; Hu, C.; Miyashita, T.; Porter, F.; Zhang, L.; Zhu, R.-Y.; Grancagnolo, F.; Tassielli, G.; Murat, P.

    2018-02-01

    The Mu2e experiment is constructing a calorimeter consisting of 1,348 undoped CsI crystals in two disks. Each crystal has a dimension of 34 x 34 x 200 mm, and is readout by a large area silicon PMT array. A series of technical specifications was defined according to physics requirements. Preproduction CsI crystals were procured from three firms: Amcrys, Saint-Gobain and Shanghai Institute of Ceramics. We report the quality assurance on crystal's scintillation properties and their radiation hardness against ionization dose and neutrons. With a fast decay time of 30 ns and a light output of more than 100 p.e./MeV measured with a bi-alkali PMT, undoped CsI crystals provide a cost-effective solution for the Mu2e experiment.

  11. Theoretical study of the Cs isotope exchange reaction of CsI + Cs' → Cs + ICs' (Contract research)

    International Nuclear Information System (INIS)

    Kobayashi, Takanori; Hashimoto, Masashi; Yokoyama, Keiichi

    2015-12-01

    To discuss the exchange reaction of Cs isotope by CsI + Cs' → Cs + ICs', the structure and chemical properties of Cs 2 I intermediate and potential energy surface of the entrance reaction are calculated using M06/def2-TZVPPD density functional calculation. The calculation shows that the reaction to the intermediate has no barrier and the two Cs-I bonds of Cs 2 I are chemically equivalent. These results suggest that the rate of the Cs exchange reaction of CsI + Cs' → Cs + ICs' is as high as the collision rate. (author)

  12. Compton profiles and band structure calculations of CdS and CdTe

    International Nuclear Information System (INIS)

    Heda, N.L.; Mathur, S.; Ahuja, B.L.; Sharma, B.K.

    2007-01-01

    In this paper we present the isotropic Compton profiles of zinc-blende CdS and CdTe measured at an intermediate resolution of 0.39 a.u. using our 20 Ci 137 Cs Compton spectrometer. The electronic band structure calculations for both the zinc-blende structure compounds and also wurtzite CdS have been undertaken using various schemes of ab-initio linear combination of atomic orbitals calculations implemented in CRYSTAL03 code. The band structure and Mulliken's populations are reported using density functional scheme. In case of wurtzite CdS, our theoretical anisotropies in directional Compton profiles are compared with available experimental data. In case of both the zinc-blende compounds, the isotropic experimental profiles are found to be in better agreement with the present Hartree-Fock calculations. A study of the equal-valence-electron-density experimental profiles of zinc-blende CdS and CdTe shows that the CdS is more ionic than CdTe. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Bismuth zinc vanadate, BiZn{sub 2}VO{sub 6}: New crystal structure type and electronic structure

    Energy Technology Data Exchange (ETDEWEB)

    Eliziario Nunes, Sayonara [Department of Chemistry, Durham University, South Road, Durham DH1 3LE (United Kingdom); Department of Materials Engineering, Federal University of São Carlos, 13565-905 São Carlos, SP (Brazil); Wang, Chun-Hai; So, Karwei; Evans, John S.O. [Department of Chemistry, Durham University, South Road, Durham DH1 3LE (United Kingdom); Evans, Ivana Radosavljević, E-mail: ivana.radosavljevic@durham.ac.uk [Department of Chemistry, Durham University, South Road, Durham DH1 3LE (United Kingdom)

    2015-02-15

    We report a combined experimental and computational study of the crystal structure and electronic properties of bismuth zinc vanadate, BiZn{sub 2}VO{sub 6}, known for its visible light photocatalytic activity. The crystal structure has been solved from laboratory powder X-ray diffraction data using the repeated minimisations from random starting values method. BiZn{sub 2}VO{sub 6} adopts a new structure type, based on the following building blocks: corner- and edge-sharing ZnO{sub 4} tetrahedra, ZnO{sub 6} octahedra and VO{sub 4} tetrahedra, and Bi{sub 2}O{sub 12} dimers. It is the only known member of the BiM{sub 2}AO{sub 6} (M=Pb, Ca, Cd, Mn, Zn, Mg, Cu; A=V, P, As) family which does not appear to be structurally closely related to others. The electronic structure of BiZn{sub 2}VO{sub 6}, calculated by DFT methods, shows that it is an indirect gap semiconductor with a calculated band gap of 1.6 eV, which compares favourably to the experimentally measured value of 2.4 eV. - Graphical abstract: The crystal structure of BiZn{sub 2}VO{sub 6}, a new structure type in the BiM{sub 2}AO{sub 6} (M=Mg, Ca, Cd, Cu, Pb, Mn, Zn; A=V, P, As) family. - Highlights: • Structure solution from PXRD data by repeated minimisations from random starting values. • New structure type in the BiM{sub 2}AO{sub 6} (M=Pb, Ca, Cd, Mn, Zn, Mg, Cu; A=V, P, As) family. • Electronic structure calculation.

  14. On some regularities of metal oxide solubility in molten CsI at T = 973 K

    Energy Technology Data Exchange (ETDEWEB)

    Cherginets, V.L., E-mail: v_cherginets@ukr.net [Institute for Scintillation Materials, National Academy of Sciences of Ukraine, Lenin Avenue, 60, Kharkov 61001 (Ukraine); National Technical University ' Kharkiv Polytechnical Institute' , 21 Frunze St., 61002 Kharkov (Ukraine); Rebrova, T.P.; Datsko, Yu.N.; Shtitelman, V.A. [Institute for Scintillation Materials, National Academy of Sciences of Ukraine, Lenin Avenue, 60, Kharkov 61001 (Ukraine); Bryleva, E.Yu. [State Scientific Organization STC ' Institute for Single Crystals' , National Academy of Sciences of Ukraine, Lenin Avenue, 60, Kharkov 61001 (Ukraine)

    2011-08-15

    Highlights: > CdO, ZnO, NiO, and EuO are insoluble in CsI melt at 973 K. > The oxide solubilities are lower than those in chloride melts. > The oxide solubilities reduce with the cation radius. > ZnO, NiO, and EuO are suitable for scavenging CsO from oxide ion traces. - Abstract: Solubility products of CdO (pK{sub s,CdO} = 6.80 {+-} 0.2), ZnO (pK{sub s,ZnO} = 10.0 {+-} 0.5), NiO (pK{sub s,NiO} = 11.2 {+-} 0.2) and EuO (pK{sub s,EuO} = 13.1 {+-} 0.2) in molten CsI at T = 973 K are determined by potentiometric titration of (0.02 to 0.03) mol . kg{sup -1} solutions of the corresponding metal chlorides by strong base (KOH) using a membrane oxygen electrode Pt(O{sub 2})|ZrO{sub 2}(Y{sub 2}O{sub 3}) as an indicator. On the basis of pK{sub s,MeO} values, all the oxides studied are referred to practically insoluble in molten CsI. The values of the oxide solubility in CsI melt are lower than the corresponding values in molten alkali metal chlorides. This can be explained by 'softer' basic properties of I{sup -} as compared with Cl{sup -} in the frames of the Pearson 'hard' and 'soft' acid-base concept. In the oxide samples studied, the values of the solubility fall with the decreasing cation radius. The correlation between pK{sub s,MeO} and the polarizing action by Goldshmidt (Zr{sub Me{sup 2+}}{sup -2}) of the cation is practically linear and may be proposed for estimation of the solubility of s- and d- element oxides in molten CsI on the basis of their cation radii.

  15. CEA/CD3-bispecific T cell-engaging (BiTE) antibody-mediated T lymphocyte cytotoxicity maximized by inhibition of both PD1 and PD-L1.

    Science.gov (United States)

    Osada, Takuya; Patel, Sandip P; Hammond, Scott A; Osada, Koya; Morse, Michael A; Lyerly, H Kim

    2015-06-01

    Bispecific T cell-engaging (BiTE) antibodies recruit polyclonal cytotoxic T cells (CTL) to tumors. One such antibody is carcinoembryonic antigen (CEA) BiTE that mediates T cell/tumor interaction by simultaneously binding CD3 expressed by T cells and CEA expressed by tumor cells. A widely operative mechanism for mitigating cytotoxic T cell-mediated killing is the interaction of tumor-expressed PD-L1 with T cell-expressed PD-1, which may be partly reversed by PD-1/PD-L1 blockade. We hypothesized that PD-1/PD-L1 blockade during BiTE-mediated T cell killing would enhance CTL function. Here, we determined the effects of PD-1 and PD-L1 blockade during initial T cell-mediated killing of CEA-expressing human tumor cell lines in vitro, as well as subsequent T cell-mediated killing by T lymphocytes that had participated in tumor cell killing. We observed a rapid upregulation of PD-1 expression and diminished cytolytic function of T cells after they had engaged in CEA BiTE-mediated killing of tumors. T cell cytolytic activity in vitro could be maximized by administration of anti-PD-1 or anti-PD-L1 antibodies alone or in combination if applied prior to a round of T cell killing, but T cell inhibition could not be fully reversed by this blockade once the T cells had killed tumor. In conclusion, our findings demonstrate that dual blockade of PD-1 and PD-L1 maximizes T cell killing of tumor directed by CEA BiTE in vitro, is more effective if applied early, and provides a rationale for clinical use.

  16. Therapeutic Efficacy of Alpha-RIT Using a (213)Bi-Anti-hCD138 Antibody in a Mouse Model of Ovarian Peritoneal Carcinomatosis.

    Science.gov (United States)

    Derrien, Aurélie; Gouard, Sébastien; Maurel, Catherine; Gaugler, Marie-Hélène; Bruchertseifer, Frank; Morgenstern, Alfred; Faivre-Chauvet, Alain; Classe, Jean-Marc; Chérel, Michel

    2015-01-01

    Ovarian peritoneal carcinomatosis is a pathology for which effective cures are currently lacking. New research protocols seek to eradicate residual micrometastases following cytoreductive surgery by using hyperthermic intraperitoneal chemotherapy (HIPEC) or radioimmunotherapy (RIT). This study aims to first develop alpha-RIT using an anti-CD138 mAb radiolabeled with an alpha-emitter, bismuth-213 ((213)Bi-B-B4) and HIPEC in a nude mouse model and second to compare and combine these techniques. A murine model of postoperative ovarian peritoneal carcinomatosis was established. A pilot group of six mice received an intraperitoneal injection of luciferase-tagged SHIN-3 cells and bioluminescence was measured every day. Cytoreductive surgery was performed at day 14 (n = 4) and 29 (n = 2). Because the residual bioluminescence signal measured after surgery was equivalent to that obtained 3 days after the graft, HIPEC or alpha-RIT treatments were applied 3 days after the graft. Ten mice were treated by HIPEC with cisplatine (37.5 mg/mL), 11 with 7.4 MBq of (213)Bi-B-B4, seven with 11.1 MBq of (213)Bi-B-B4, and 10 mice were treated with the combined therapy (HIPEC + 7.4 MBq of (213)Bi-B-B4). Eleven mice received no treatment. Bioluminescence imaging and survival were assessed. Alpha-RIT 7.4 MBq and 11.1 MBq significantly improved survival (p = 0.0303 and p = 0.0070, respectively), whereas HIPEC and HIPEC + alpha-RIT treatments did not significantly ameliorate survival as compared to the control group. Survival was significantly increased by alpha-RIT treatment in mice with peritoneal carcinomatosis of ovarian origin; however, HIPEC alone or in combination with alpha-RIT had no significant effect.

  17. An optimized multilayer structure of CdS layer for CdTe solar cells application

    International Nuclear Information System (INIS)

    Han Junfeng; Liao Cheng; Jiang Tao; Spanheimer, C.; Haindl, G.; Fu, Ganhua; Krishnakumar, V.; Zhao Kui; Klein, A.; Jaegermann, W.

    2011-01-01

    Research highlights: → Two different methods to prepare CdS films for CdTe solar cells. → A new multilayer structure of window layer for the CdTe solar cell. → Thinner CdS window layer for the solar cell than the standard CdS layer. → Higher performance of solar cells based on the new multilayer structure. - Abstract: CdS layers grown by 'dry' (close space sublimation) and 'wet' (chemical bath deposition) methods are deposited and analyzed. CdS prepared with close space sublimation (CSS) has better crystal quality, electrical and optical properties than that prepared with chemical bath deposition (CBD). The performance of CdTe solar cell based on the CSS CdS layer has higher efficiency than that based on CBD CdS layer. However, the CSS CdS suffers from the pinholes. And consequently it is necessary to prepare a 150 nm thin film for CdTe/CdS solar cell. To improve the performance of CdS/CdTe solar cells, a thin multilayer structure of CdS layer (∼80 nm) is applied, which is composed of a bottom layer (CSS CdS) and a top layer (CBD CdS). That bi-layer film can allow more photons to pass through it and significantly improve the short circuit current of the CdS/CdTe solar cells.

  18. Pressure-induced structural phase transition and elastic properties in rare earth CeBi and LaBi

    International Nuclear Information System (INIS)

    Mankad, Venu; Gupta, Sanjay D.; Gupta, Sanjeev K.; Jha, Prafulla

    2011-01-01

    Pressure is one of the external parameters by which the interplay of the f-electrons with the normal conduction electrons may be varied. At ambient conditions the rare-earth compounds are characterized by a fixed f n configuration of atomic-like f-electrons, but the decreased lattice spacing resulting from the application of pressure eventually leads to the destabilization of the f-shell. The theoretical description of this electronic transition remains a challenge. The present study reports a comprehensive study on structural, electronic band structures, elastic and lattice dynamical properties of rare earth monopnictides CeBi and LaBi using first principles density functional calculations within the pseudopotential approximation. Both compounds possess NaCI (B1) structure at ambient pressure and transform either to CsCI or body centered tetragonal (BCT) structure. Our results concerning equilibrium lattice parameter and bulk modulus agree well with the available experimental and previous theoretical data. The volume change at the crystallographic transition is attributed to a decrease of the cerium valence or a lowering of the p-f hybridization due to the larger interatomic distances in both high pressure phases. The equation of state for rare earth bismuth compounds are calculated and compared with available experimental results. From the total energy and relative volume one can clearly see the relative stabilities of the high pressure phases of both compounds. As the primitive tetragonal phase of both compounds. As the primitive tetragonal phase can be viewed as a CsCl structure, one may think of a transition from B1 to B2. We have also calculated band structure for both phase and here we have presented for B1 case. The narrow bands originating above the Fermi level are mainly due to Ce 'f'-like states, and the major contribution to the density of states is mainly from Ce 'd'-like states. Furthermore, in high-pressure CsCI phase, there is an appreciable

  19. Thermoelectric transport properties of BaBiTe{sub 3}-based materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yiming; Zhao, Li-Dong, E-mail: zhaolidong@buaa.edu.cn

    2017-05-15

    BaBiTe{sub 3}, a material with low thermal conductivity, is an inferior thermoelectric material due to the poor electrical properties originated from its narrow band gap. We choose two types of dopants, K and La, trying to optimize its electrical transport properties. The minority carriers, which harm the Seebeck coefficient in this system, are suppressed by La doping. With the increase of both electrical conductivity and Seebeck coefficient, the power factor of 3% La doped BaBiTe{sub 3} reaches 3.7 μW cm{sup −1} K{sup −2} which increased by 40% from undoped BaBiTe{sub 3}. Besides high power factor, the thermal conductivity is also reduced in it. Eventually, a high ZT value, 0.25 at 473 K, for n-type BaBiTe{sub 3} is achieved in 3% La doped BaBiTe{sub 3}. - Graphical abstract: BaBiTe{sub 3} possesses a low thermal conductivity. However, it is an inferior thermoelectric material due to the poor electrical properties originated from its narrow band gap. A high ZT value of 0.25 at 473 K for n-type BaBiTe{sub 3} can be achieved through optimizing electrical transport properties via La doping. - Highlights: • BaBiTe{sub 3} is an analogue of these promising thermoelectric materials: such as CsBi{sub 4}Te{sub 6} and K{sub 2}Bi{sub 8}Se{sub 13}, etc. • BaBiTe{sub 3} possesses a low thermal conductivity. • La is an effective dopant to enhance electrical transport properties. • A high ZT value of 0.25 at 473 K can be achieved in n-type La-doped BaBiTe{sub 3}.

  20. CS Informativeness Governs CS-US Associability

    Science.gov (United States)

    Ward, Ryan D.; Gallistel, C. R.; Jensen, Greg; Richards, Vanessa L.; Fairhurst, Stephen; Balsam, Peter D

    2012-01-01

    In a conditioning protocol, the onset of the conditioned stimulus (CS) provides information about when to expect reinforcement (the US). There are two sources of information from the CS in a delay conditioning paradigm in which the CS-US interval is fixed. The first depends on the informativeness, the degree to which CS onset reduces the average expected time to onset of the next US. The second depends only on how precisely a subject can represent a fixed-duration interval (the temporal Weber fraction). In three experiments with mice, we tested the differential impact of these two sources of information on rate of acquisition of conditioned responding (CS-US associability). In Experiment 1, we show that associability (the inverse of trials to acquisition) increases in proportion to informativeness. In Experiment 2, we show that fixing the duration of the US-US interval or the CS-US interval or both has no effect on associability. In Experiment 3, we equated the increase in information produced by varying the C̅/T̅ ratio with the increase produced by fixing the duration of the CS-US interval. Associability increased with increased informativeness, but, as in Experiment 2, fixing the CS-US duration had no effect on associability. These results are consistent with the view that CS-US associability depends on the increased rate of reward signaled by CS onset. The results also provide further evidence that conditioned responding is temporally controlled when it emerges. PMID:22468633

  1. Are BiTEs the "missing link" in cancer therapy?

    Science.gov (United States)

    Suryadevara, Carter M; Gedeon, Patrick C; Sanchez-Perez, Luis; Verla, Terence; Alvarez-Breckenridge, Christopher; Choi, Bryan D; Fecci, Peter E; Sampson, John H

    2015-06-01

    Conventional treatment for cancer routinely includes surgical resection and some combination of chemotherapy and radiation. These approaches are frequently accompanied by unintended and highly toxic collateral damage to healthy tissues, which are offset by only marginal prognostic improvements in patients with advanced cancers. This unfortunate balance has driven the development of novel therapies that aim to target tumors both safely and efficiently. Over the past decade, mounting evidence has supported the therapeutic utility of T-cell-centered cancer immunotherapy, which, in its various iterations, has been shown capable of eliciting highly precise and robust antitumor responses both in animal models and human trials. The identification of tumor-specific targets has further fueled a growing interest in T-cell therapies given their potential to circumvent the non-specific nature of traditional treatments. Of the several strategies geared toward achieving T-cell recognition of tumor, bispecific antibodies (bsAbs) represent a novel class of biologics that have garnered enthusiasm in recent years due to their versatility, specificity, safety, cost, and ease of production. Bispecific T-cell Engagers (BiTEs) are a subclass of bsAbs that are specific for CD3 on one arm and a tumor antigen on the second. As such, BiTEs function by recruiting and activating polyclonal populations of T-cells at tumor sites, and do so without the need for co-stimulation or conventional MHC recognition. Blinatumomab, a well-characterized BiTE, has emerged as a promising recombinant bscCD19×CD3 construct that has demonstrated remarkable antitumor activity in patients with B-cell malignancies. This clinical success has resulted in the rapid extension of BiTE technology against a greater repertoire of tumor antigens and the recent US Food and Drug Administration's (FDA) accelerated approval of blinatumomab for the treatment of a rare form of acute lymphoblastic leukemia (ALL). In this review

  2. Cd(II) removal from aqueous solution by adsorption on α-ketoglutaric acid-modified magnetic chitosan

    International Nuclear Information System (INIS)

    Yang, Guide; Tang, Lin; Lei, Xiaoxia; Zeng, Guangming; Cai, Ye; Wei, Xue; Zhou, Yaoyu; Li, Sisi; Fang, Yan; Zhang, Yi

    2014-01-01

    The present study developed an α-ketoglutaric acid-modified magnetic chitosan (α-KA-Fe 3 O 4 /CS) for highly efficient adsorption of Cd(II) from aqueous solution. Several techniques, including transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and vibrating sample magnetometer (VSM), were applied to characterize the adsorbent. Batch tests were conducted to investigate the Cd(II) adsorption performance of α-KA-Fe 3 O 4 /CS. The maximum adsorption efficiency of Cd(II) appeared at pH 6.0 with the value of 93%. The adsorption amount was large and even reached 201.2 mg/g with the initial Cd(II) concentration of 1000 mg/L. The adsorption equilibrium was reached within 30 min and commendably described by pseudo-second-order model, and Langmuir model fitted the adsorption isotherm better. Furthermore, thermodynamic parameters, free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) of Cd(II) adsorption were also calculated and showed that the overall adsorption process was endothermic and spontaneous in nature because of positive ΔH values and negative ΔG values, respectively. Moreover, the Cd(II)-loaded α-KA-Fe 3 O 4 /CS could be regenerated by 0.02 mol/L NaOH solution, and the cadmium removal capacity could still be kept around 89% in the sixth cycle. All the results indicated that α-KA-Fe 3 O 4 /CS was a promising adsorbent in environment pollution cleanup.

  3. Vaccine efficacy against malaria by the combination of porcine parvovirus-like particles and vaccinia virus vectors expressing CS of Plasmodium.

    Science.gov (United States)

    Rodríguez, Dolores; González-Aseguinolaza, Gloria; Rodríguez, Juan R; Vijayan, Aneesh; Gherardi, Magdalena; Rueda, Paloma; Casal, J Ignacio; Esteban, Mariano

    2012-01-01

    With the aim to develop an efficient and cost-effective approach to control malaria, we have generated porcine parvovirus-like particles (PPV-VLPs) carrying the CD8(+) T cell epitope (SYVPSAEQI) of the circumsporozoite (CS) protein from Plasmodium yoelii fused to the PPV VP2 capsid protein (PPV-PYCS), and tested in prime/boost protocols with poxvirus vectors for efficacy in a rodent malaria model. As a proof-of concept, we have characterized the anti-CS CD8(+) T cell response elicited by these hybrid PPV-VLPs in BALB/c mice after immunizations with the protein PPV-PYCS administered alone or in combination with recombinant vaccinia virus (VACV) vectors from the Western Reserve (WR) and modified virus Ankara (MVA) strains expressing the entire P. yoelii CS protein. The results of different immunization protocols showed that the combination of PPV-PYCS prime/poxvirus boost was highly immunogenic, inducing specific CD8+ T cell responses to CS resulting in 95% reduction in liver stage parasites two days following sporozoite challenge. In contrast, neither the administration of PPV-PYCS alone nor the immunization with the vectors given in the order poxvirus/VLPs was as effective. The immune profile induced by VLPs/MVA boost was associated with polyfunctional and effector memory CD8+ T cell responses. These findings highlight the use of recombinant parvovirus PPV-PYCS particles as priming agents and poxvirus vectors, like MVA, as booster to enhance specific CD8+ T cell responses to Plasmodium antigens and to control infection. These observations are relevant in the design of T cell-inducing vaccines against malaria.

  4. Molecular structures and thermodynamic properties of 12 gaseous cesium-containing species of nuclear safety interest: Cs 2, CsH, CsO, Cs 2O, CsX, and Cs 2X 2 (X = OH, Cl, Br, and I)

    Science.gov (United States)

    Badawi, Michael; Xerri, Bertrand; Canneaux, Sébastien; Cantrel, Laurent; Louis, Florent

    2012-01-01

    Ab initio electronic structure calculations at the coupled cluster level with a correction for the triples extrapolated to the complete basis set limit have been made for the estimation of the thermochemical properties of Cs 2, CsH, CsO, Cs 2O, CsX, and Cs 2X 2 (X = OH, Cl, Br, and I). The standard enthalpies of formation and standard molar entropies at 298 K, and the temperature dependence of the heat capacities at constant pressure were evaluated. The calculated thermochemical properties are in good agreement with their literature counterparts. For Cs 2, CsH, CsOH, Cs 2(OH) 2, CsCl, Cs 2Cl 2, CsBr, CsI, and Cs 2I 2, the calculated ΔfH298K∘ values are within chemical accuracy of the most recent experimental values. Based on the excellent agreement observed between our calculated ΔfH298K∘ values and their literature counterparts, the standard enthalpies of formation at 298 K are estimated to be the following: ΔfH298K∘ (CsO) = 17.0 kJ mol -1 and ΔfH298K∘ (Cs 2Br 2) = -575.4 kJ mol -1.

  5. Preparation, characterization, and anti-Helicobacter pylori activity of Bi3+-Hericium erinaceus polysaccharide complex.

    Science.gov (United States)

    Zhu, Yang; Chen, Yao; Li, Qian; Zhao, Ting; Zhang, Ming; Feng, Weiwei; Takase, Mohammed; Wu, Xueshan; Zhou, Zhaoxiang; Yang, Liuqing; Wu, Xiangyang

    2014-09-22

    Two new Bi3+-Hericium erinaceus polysaccharide (BiHEP) complexes were prepared using Bi3+ and two purified polysaccharides from H. erinaceus (HEPs), respectively. The complexes were characterized by elemental analysis, FT-IR, CD, SEM, AFM, XRD, and TG. The anti-Helicobacter pylori (Hp) activities in vitro by agar dilution assay of the complexes were evaluated. The molecular weights of HEPs were 197 and 20 kDa, respectively. All the analyses confirmed the formation of new BiHEP complexes with lower content of Bi3+ compared with colloidal bismuth subcitrate (CBS), the most utilized bismuth preparation clinically. Furthermore, HEPs themselves have definite inhibition effects on Hp, and BiHEP complexes have lower content of Bi exhibited strong inhibition effects on Hp (MIC=20 μg/mL), similar to that of CBS with higher content of Bi. The study provides a basis for further development of multiple treatments of Hp infection or new medicines. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Near-Ultraviolet Observations of CS 29497-030: New Constraints on Neutron-Capture Nucleosynthesis Processes

    Science.gov (United States)

    Ivans, Inese I.; Sneden, Christopher; Gallino, Roberto; Cowan, John J.; Preston, George W.

    2005-07-01

    Employing spectra obtained with the new Keck I HIRES near-UV-sensitive detector, we have performed a comprehensive chemical composition analysis of the binary blue metal-poor star CS 29497-030. Abundances for 29 elements and upper limits for an additional seven have been derived, concentrating on elements largely produced by means of neutron-capture nucleosynthesis. Included in our analysis are the two elements that define the termination point of the slow neutron-capture process, lead and bismuth. We determine an extremely high value of [Pb/Fe]=+3.65+/-0.07 (σ=0.13) from three features, supporting the single-feature result obtained in previous studies. We detect Bi for the first time in a metal-poor star. Our derived Bi/Pb ratio is in accord with those predicted from the most recent FRANEC calculations of the slow neutron-capture process in low-mass asymptotic giant branch (AGB) stars. We find that the neutron-capture elemental abundances of CS 29497-030 are best explained by an AGB model that also includes very significant amounts of pre-enrichment of rapid neutron-capture process material in the protostellar cloud out of which the CS 29497-030 binary system formed. Mass transfer is consistent with the observed [Nb/Zr]~0. Thus, CS 29497-030 is both an r+s and ``extrinsic AGB'' star. Furthermore, we find that the mass of the AGB model can be further constrained by the abundance of the light odd-element Na. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  7. Efficient Inorganic Perovskite Light-Emitting Diodes with Polyethylene Glycol Passivated Ultrathin CsPbBr3 Films.

    Science.gov (United States)

    Song, Li; Guo, Xiaoyang; Hu, Yongsheng; Lv, Ying; Lin, Jie; Liu, Zheqin; Fan, Yi; Liu, Xingyuan

    2017-09-07

    Efficient inorganic perovskite light-emitting diodes (PeLEDs) with an ultrathin perovskite emission layer (∼30 nm) were realized by doping Lewis base polyethylene glycol (PEG) into CsPbBr 3 films. PEG in the perovskite films not only physically fills the crystal boundaries but also interacts with the perovskite crystals to passivate the crystal grains, reduce nonradiative recombination, and ensure efficient luminance and high efficiency. As a result, promoted brightness, current efficiency (CE), and external quantum efficiency (EQE) were achieved. The nonradiative decay rate of the PEG:CsPbBr 3 composite film is 1 order of magnitude less than that of the neat CsPbBr 3 film. After further optimization of the molar ratio between CsBr and PbBr 2 , a peak CE of 19 cd/A, a maximum EQE of 5.34%, and a maximum brightness of 36600 cd/m 2 were achieved, demonstrating the interaction between PEG and the precursors. The results are expected to offer some helpful implications in optimizing the polymer-assisted PeLEDs with ultrathin emission layers, which might have potential application in see-through displays.

  8. Vaccine efficacy against malaria by the combination of porcine parvovirus-like particles and vaccinia virus vectors expressing CS of Plasmodium.

    Directory of Open Access Journals (Sweden)

    Dolores Rodríguez

    Full Text Available With the aim to develop an efficient and cost-effective approach to control malaria, we have generated porcine parvovirus-like particles (PPV-VLPs carrying the CD8(+ T cell epitope (SYVPSAEQI of the circumsporozoite (CS protein from Plasmodium yoelii fused to the PPV VP2 capsid protein (PPV-PYCS, and tested in prime/boost protocols with poxvirus vectors for efficacy in a rodent malaria model. As a proof-of concept, we have characterized the anti-CS CD8(+ T cell response elicited by these hybrid PPV-VLPs in BALB/c mice after immunizations with the protein PPV-PYCS administered alone or in combination with recombinant vaccinia virus (VACV vectors from the Western Reserve (WR and modified virus Ankara (MVA strains expressing the entire P. yoelii CS protein. The results of different immunization protocols showed that the combination of PPV-PYCS prime/poxvirus boost was highly immunogenic, inducing specific CD8+ T cell responses to CS resulting in 95% reduction in liver stage parasites two days following sporozoite challenge. In contrast, neither the administration of PPV-PYCS alone nor the immunization with the vectors given in the order poxvirus/VLPs was as effective. The immune profile induced by VLPs/MVA boost was associated with polyfunctional and effector memory CD8+ T cell responses. These findings highlight the use of recombinant parvovirus PPV-PYCS particles as priming agents and poxvirus vectors, like MVA, as booster to enhance specific CD8+ T cell responses to Plasmodium antigens and to control infection. These observations are relevant in the design of T cell-inducing vaccines against malaria.

  9. Molecular CsF 5 and CsF 2 +

    KAUST Repository

    Rogachev, Andrey Yu.; Miao, Mao-sheng; Merino, Gabriel; Hoffmann, Roald

    2015-01-01

    D5h star-like CsF5, formally isoelectronic with known XeF5− ion, is computed to be a local minimum on the potential energy surface of CsF5, surrounded by reasonably large activation energies for its exothermic decomposition to CsF+2 F2, or to CsF3 (three isomeric forms)+F2, or for rearrangement to a significantly more stable isomer, a classical Cs+ complex of F5−. Similarly the CsF2+ ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

  10. Molecular CsF 5 and CsF 2 +

    KAUST Repository

    Rogachev, Andrey Yu.

    2015-06-03

    D5h star-like CsF5, formally isoelectronic with known XeF5− ion, is computed to be a local minimum on the potential energy surface of CsF5, surrounded by reasonably large activation energies for its exothermic decomposition to CsF+2 F2, or to CsF3 (three isomeric forms)+F2, or for rearrangement to a significantly more stable isomer, a classical Cs+ complex of F5−. Similarly the CsF2+ ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

  11. Evaluation of matrix effect on the determination of rare earth elements and As, Bi, Cd, Pb, Se and In in honey and pollen of native Brazilian bees (Tetragonisca angustula - Jataí) by Q-ICP-MS.

    Science.gov (United States)

    de Oliveira, Fernanda Ataide; de Abreu, Adriana Trópia; de Oliveira Nascimento, Nathália; Froes-Silva, Roberta Eliane Santos; Antonini, Yasmine; Nalini, Hermínio Arias; de Lena, Jorge Carvalho

    2017-01-01

    Bees are considered the main pollinators in natural and agricultural environments. Chemical elements from honey and pollen have been used for monitoring the environment, the health of bees and the quality of their products. Nevertheless, there are not many studies on honey and pollen of native Brazilian bees. The goal of this work was to determine important chemical elements (Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Lu and Yb) along with As, Bi, Cd, Pb, Se and In, in honey and pollen of native Brazilian bees, assessing analytical interferences from the matrix. A proposed analytical method was developed for these elements by quadrupole ICP-MS. Matrix effect was verified in honey matrix in the quantification of As, Bi and Dy; and in pollen matrix for Bi, Cd, Ce, Gd, La, Pb and Sc. The quality of the method was considered satisfactory taking into consideration the recovery rate of each element in the spiked solutions: honey matrix (91.6-103.9%) and pollen matrix (94.1-115.6%). The quantification limits of the method ranged between 0.00041 and 10.3μgL -1 for honey and 0.00041-0.095μgL -1 for pollen. The results demonstrate that the method is accurate, precise and suitable. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Post-transplant sCD30 and neopterin as predictors of chronic allograft nephropathy: impact of different immunosuppressive regimens.

    Science.gov (United States)

    Weimer, R; Süsal, C; Yildiz, S; Staak, A; Pelzl, S; Renner, F; Dietrich, H; Daniel, V; Kamali-Ernst, S; Ernst, W; Padberg, W; Opelz, G

    2006-08-01

    Immunological monitoring for chronic allograft nephropathy (CAN) is of great potential interest. We assessed serum soluble CD30 (sCD30) together with in vitro Th2-type responses (IL-4, IL-10, CD4 helper activity) and neopterin in a prospective study of 84 renal transplant recipients with 2-year follow-up. Patients were randomized to CsA/Aza, CsA/MMF and Tacr/Aza, respectively, to analyze the effect of immunosuppression on posttransplant sCD30 and neopterin. ATG induction and acute rejections did not alter sCD30 levels whereas CMV disease was associated with transient upregulation of sCD30 (p = 0.003 at 4 months) and sustained upregulation of neopterin (corrected for graft function (Neo/CR) p = 0.005 at 2 years). Tacr versus CsA treatment proved to be an independent variable associated with downregulation of 1-year sCD30, which was positively related to Neo/CR (p = 0.007 and 0.01, respectively; logistic regression). Importantly, increased 1-year sCD30 and Neo/CR were associated with decreased glomerular filtration rate at 2 years (p = 0.02 and p sCD30 could not be attributed to enhanced Th2-type responses and was not associated with HLA antibody formation. Our data suggest that elevated sCD30 and neopterin predict graft deterioration by CAN. Tacr effectively downregulates these responses and might be of advantage in patients with elevated sCD30 or neopterin.

  13. Monotectic four-phase reaction in Al-Bi-Zn alloys

    Energy Technology Data Exchange (ETDEWEB)

    Groebner, J. [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany); Mirkovic, D. [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany); Schmid-Fetzer, R. [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany)]. E-mail: schmid-fetzer@tu-clausthal.de

    2005-06-15

    Thermodynamic phase diagram calculations were used for the systematic search for a monotectic four-phase reaction in ternary Al-alloys. Systems with intermetallic phases and also the elements Cd and Hg were excluded in the present search. The ternary Al-Bi-Zn is a rare occasion where such a reaction, L' = L' + (Al)' + (Zn), actually occurs. Experimental work could be focused on key samples in that system and involved DSC for thermal analysis and calorimetry, and also metallographic analysis using SEM/EDX. Experimental results verify the existence of the monotectic reaction and were also used for a quantitative thermodynamic modeling of Al-Bi-Zn. Solidification paths and microstructures of Al-Bi-Zn alloys are shown to be rather complex. Using thermodynamic calculations, these rich details involving up to three invariant reactions and unexpected monovariant reaction types can be clearly revealed and understood.

  14. Development and measurement of luminescence properties of Ce-doped Cs2LiGdBr6 crystals irradiated with X-ray, γ-ray and proton beam

    Science.gov (United States)

    Jang, Jonghun; Kim, H. J.; Rooh, Gul; Kim, Sunghwan

    2017-12-01

    The effect of higher Ce-concentration on the luminescence and scintillation properties of Cs2LiGdBr6 single crystals are studied. We used the Bridgman method for the growth of Ce-doped Cs2LiGdBr6 single crystals. Luminescence properties of the grown crystals are measured by X-ray and proton excitations. We measured the pulse height and fluorescence decay time spectra of Cs2LiGdBr6:Ce3+ with a bi-alkali photo multiplier tube (PMT) under γ-ray excitation from 137Cs source. Improvements in the scintillation properties are observed with the increase of Ce-concentration in the lattice. Detailed procedure of the crystal growth is also discussed.

  15. Bismuth 213-labeled anti-CD45 radioimmunoconjugate to condition dogs for nonmyeloablative allogeneic marrow grafts

    Energy Technology Data Exchange (ETDEWEB)

    Sandmaier, B M.(Fred Hutchinson Cancer Research Center, Seattle, WA); Bethge, W A.(Fred Hutchinson Cancer Research Center, Seattle, WA); Wilbur, D. Scott (Washington, Univ Of); Hamlin, Donald K.(Washington, Univ Of); Santos, E B.(Fred Hutchinson Cancer Research Center, Seattle, WA); Brechbiel, M W.(National Cancer Institute, National Institutes of Health, Bethesda, MD); Fisher, Darrell R.(BATTELLE (PACIFIC NW LAB)); Storb, R. (Fred Hutchinson Cancer Research Center)

    2002-01-01

    To lower treatment-related mortality and toxicity of conventional marrow transplantation, a nonmyeloablative regimen using 200 cGy total-body irradiation (TBI) and mycophenolate mofetil (MMF) combined with cyclosporine (CSP) for postgrafting immunosuppression was developed. To circumvent possible toxic effects of external- beam gamma irradiation, strategies for targeted radiation therapy were investigated. We tested whether the short-lived (46 minutes) alpha-emitter Bi-213 conjugated to an anti-CD45 monoclonal antibody (mAb) could replace 200 cGy TBI and selectively target hematopoietic tissues in a canine model of nonmyeloablative DLA-identical marrow transplantation. Biodistribution studies using iodine 123-labeled anti-CD45 mAb showed uptake in blood, marrow, lymph nodes, spleen, and liver. In a dose-escalation study, 7 dogs treated with the Bi-213-anti-CD45 conjugate (Bi-213 dose, 0.1-5.9 mCi/kg[3.7-218 MBq/kg]) without marrow grafts had no toxic effects other than a mild, reversible suppression of blood counts. On the basis of these studies, 3 dogs were treated with 0.5 mg/kg Bi-213-labeled anti-CD45 mAb (Bi-213 doses, 3.6, 4.6, and 8.8 mCi/kg[133, 170, and 326 MBq/kg]) given in 6 injections 3 and 2 days before grafting of marrow from DLA-identical littermates. The dogs also received MMF (10 mg/kg subcutaneously twice daily the day of transplantation until day 27 afterward) and CSP (15 mg/kg orally twice daily the day before transplantation until 35 days afterward). Therapy was well tolerated except for transient elevations in levels of transaminases in 3 dogs, followed by, in one dog, ascites. All dogs achieved prompt engraftment and stable mixed hematopoietic chimerism, with donor contributions ranging from 30% to 70% after more than 27 weeks of follow-up. These results form the basis for additional studies in animals and the design of clinical trials using Bi-213 as a nonmyeloablative conditioning regimen with minimal toxicity.

  16. Stabilization of metal-oxide bulk switching device with diffused Bi contacts

    International Nuclear Information System (INIS)

    Lalevic, B.; Shoga, M.; Gvishi, M.; Levy, S.; Army ERADCOM, Ft. Monmouth, NJ)

    1979-01-01

    Threshold switching from the high to low resistance state has been investigated in the polycrystalline and single crystal NbO/sub x/ (where x is approximately = 2) metal-oxide devices. Stable and reproducible switching performance is observed in a configuration Bi-NbO 2 -Bi where Bi electrodes were covered with Au films. Improvement in the device performance is attributed to the Bi diffusion into NbO/sub x/ which has been confirmed by the Auger electron spectroscopy. Typical off state resistance of these devices is approx.100 KΩ and threshold switching voltage in the range from 100 to 2500 V. The delay time tau/sub d/ is exponentially dependent on the applied voltage V/sub appl/ and at larger V/sub appl'/ the delay time is less than a nanosecond. Recovery time of a device is approx.0.5 μsec as determined by the method of decreasing time interval between two successive pulses. Holding voltage is approx.40 V. The pulsed switched devices can withstand pulse durations between 0.1 to 3 μsec, repetition rate of 100 C/s and current intensities of 10 to 15 A, or 25 A peak with the applied pulse duration of 20 μsec, single shot

  17. Mn2+ anchored CdS polymer nanocomposites: An efficient alternative for Mn2+ doped CdS nanoparticles

    International Nuclear Information System (INIS)

    Saikia, Bhaskar Jyoti; Nath, Bikash Chandra; Borah, Chandramika; Dolui, Swapan Kumar

    2015-01-01

    A chelating bi-functional polymer brushes was prepared via atom transfer radical polymerization using grafting-from methodology. Mn 2+ -anchored CdS-polymer nanocomposites were synthesized using this graft copolymer by simple chelation method resulting in emission at about 620 nm which originates from the fluorescence of manganese ions embedded on the surface of CdS nanoparticles. This method provides an efficient straightforward substitute of Mn 2+ dopped CdS nanoparticles. Optical properties of the composites were investigated which indicates that simple Mn 2+ chelation and subsequent binding of CdS in a polymer matrix can have similar effect in the luminescence property as those synthesized via complex doping methods. Moreover this methodology can be applied for synthesis of any metal anchored nanocomposites proficiently and cost effectively in large-scale production. - Highlights: • A chelating bifunctional copolymer brush was synthesized via ATRP. • CdS nanoparticles and Mn 2+ were coupled with the bifunctional polymer. • Composites showed emission properties similar to Mn 2+ doped CdS nanoparticles. • Side chain length of the polymers also affect the emission properties of the composites.

  18. Facile fabrication of a novel 3D graphene framework/Bi nanoparticle film for ultrasensitive electrochemical assays of heavy metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Lei [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China); Li, Yangyang; Rong, Xiaojiao [School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Wang, Yan [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China); Ding, Shiming, E-mail: smding@niglas.ac.cn [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China)

    2017-05-22

    In this work, a novel 3D graphene framework/Bi nanoparticle (GF/BiNP) film was fabricated with a facile preparation route. 3D graphene framework with porous structures was electrochemically reduced and in situ assembled on the electrode, and BiNPs with tunable morphologies were highly dispersed on the framework by a chemical reduction. Newly-designed 3D GF/BiNP film possessed a significantly large active area, fast electron transfer ability, high mass transfer efficiency, and excellent structure stability and binding strength on electrode. To demonstrate its superior ability, electrochemical sensors for the assay of heavy metal ions were constructed. As a result, a simultaneous assay of Pb{sup 2+} and Cd{sup 2+} with ultralow detection limits (0.02 μg L{sup −1} of Pb{sup 2+} and 0.05 μg L{sup −1} of Cd{sup 2+}, S/N = 3) and a wide linear range from 1 to 120 μg L{sup −1} was achieved. Meanwhile, a separate analysis of Zn{sup 2+} was performed to get optimum responses, in which a low detection limit of 4.0 μg L{sup −1} (S/N = 3) with a linear range from 40 to 300 μg L{sup −1} was observed, confirming the versatility of the GF/BiNP film in the detection of heavy metal ions. Moreover, excellent repeatability, reproducibility and stability, and reliable assays in real water samples were realized with constructed sensors. Due to its convenient preparation, favorable structures and excellent properties, prepared 3D GF/BiNP film will find great potential for advanced applications in environment, biomedicine and energy systems. - Highlights: • A novel 3D graphene framework/Bi nanoparticle (GF/BiNP) film is prepared. • Porous graphene framework is in situ assembled on the electrode. • BiNPs with tunable morphologies are highly dispersed on the framework. • Newly-designed 3D GF/BiNP film possesses excellent properties. • Sensitive electrochemical sensors for Pb{sup 2+}, Cd{sup 2+} and Zn{sup 2+} are constructed.

  19. Bi-level positive pressure ventilation and adaptive servo ventilation in patients with heart failure and Cheyne-Stokes respiration.

    Science.gov (United States)

    Fietze, Ingo; Blau, Alexander; Glos, Martin; Theres, Heinz; Baumann, Gert; Penzel, Thomas

    2008-08-01

    Nocturnal positive pressure ventilation (PPV) has been shown to be effective in patients with impaired left ventricular ejection fraction (LVEF) and Cheyne-Stokes respiration (CSR). We investigated the effect of a bi-level PPV and adaptive servo ventilation on LVEF, CSR, and quantitative sleep quality. Thirty-seven patients (New York heart association [NYHA] II-III) with LVEFCSR were investigated by electrocardiography (ECG), echocardiography and polysomnography. The CSR index (CSRI) was 32.3+/-16.2/h. Patients were randomly treated with bi-level PPV using the standard spontaneous/timed (S/T) mode or with adaptive servo ventilation mode (AutoSetCS). After 6 weeks, 30 patients underwent control investigations with ECG, echocardiography, and polysomnography. The CSRI decreased significantly to 13.6+/-13.4/h. LVEF increased significantly after 6 weeks of ventilation (from 25.1+/-8.5 to 28.8+/-9.8%, plevel PPV and adaptive servo ventilation: the CSRI decreased more in the AutoSetCS group while the LVEF increased more in the bi-level PPV group. Administration of PPV can successfully attenuate CSA. Reduced CSA may be associated with improved LVEF; however, this may depend on the mode of PPV. Changed LVEF is evident even in the absence of significant changes in blood pressure.

  20. Receptor complementation and mutagenesis reveal SR-BI as an essential HCV entry factor and functionally imply its intra- and extra-cellular domains.

    Directory of Open Access Journals (Sweden)

    Marlène Dreux

    2009-02-01

    Full Text Available HCV entry into cells is a multi-step and slow process. It is believed that the initial capture of HCV particles by glycosaminoglycans and/or lipoprotein receptors is followed by coordinated interactions with the scavenger receptor class B type I (SR-BI, a major receptor of high-density lipoprotein (HDL, the CD81 tetraspanin, and the tight junction protein Claudin-1, ultimately leading to uptake and cellular penetration of HCV via low-pH endosomes. Several reports have indicated that HDL promotes HCV entry through interaction with SR-BI. This pathway remains largely elusive, although it was shown that HDL neither associates with HCV particles nor modulates HCV binding to SR-BI. In contrast to CD81 and Claudin-1, the importance of SR-BI has only been addressed indirectly because of lack of cells in which functional complementation assays with mutant receptors could be performed. Here we identified for the first time two cell types that supported HCVpp and HCVcc entry upon ectopic SR-BI expression. Remarkably, the undetectable expression of SR-BI in rat hepatoma cells allowed unambiguous investigation of human SR-BI functions during HCV entry. By expressing different SR-BI mutants in either cell line, our results revealed features of SR-BI intracellular domains that influence HCV infectivity without affecting receptor binding and stimulation of HCV entry induced by HDL/SR-BI interaction. Conversely, we identified positions of SR-BI ectodomain that, by altering HCV binding, inhibit entry. Finally, we characterized alternative ectodomain determinants that, by reducing SR-BI cholesterol uptake and efflux functions, abolish HDL-mediated infection-enhancement. Altogether, we demonstrate that SR-BI is an essential HCV entry factor. Moreover, our results highlight specific SR-BI determinants required during HCV entry and physiological lipid transfer functions hijacked by HCV to favor infection.

  1. Somatostatin-receptor-targeted α-emitting 213Bi is therapeutically more effective than β--emitting 177Lu in human pancreatic adenocarcinoma cells

    International Nuclear Information System (INIS)

    Nayak, Tapan K.; Norenberg, Jeffrey P.; Anderson, Tamara L.; Prossnitz, Eric R.; Stabin, Michael G.; Atcher, Robert W.

    2007-01-01

    Introduction: Advance clinical cancer therapy studies of patients treated with somatostatin receptor (sstr)-targeted [DOTA 0 -Tyr 3 ]octreotide (DOTATOC) labeled with low-linear-energy-transfer (LET) β - -emitters have shown overall response rates in the range of 15-33%. In order to improve outcomes, we sought to compare the therapeutic effectiveness of sstr-targeted high-LET α-emitting 213 Bi to that of low-LET β - -emitting 177 Lu by determining relative biological effectiveness (RBE) using the external γ-beam of 137 Cs as reference radiation. Methods: Sstr-expressing human pancreatic adenocarcinoma Capan-2 cells and A549 control cells were used for this study. The effects of different radiation doses of 213 Bi and 177 Lu labeled to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid and sstr-targeted DOTATOC were investigated with a clonogenic cell survival assay. Apoptosis was measured using the Cell Death Detection ELISA PLUS 10x kit. Results: Using equimolar DOTATOC treatment with concurrent irradiation with a 137 Cs source as reference radiation, the calculated RBE of [ 213 Bi]DOTATOC was 3.4, as compared to 1.0 for [ 177 Lu]DOTATOC. As measured in terms of absorbance units, [ 213 Bi]DOTATOC caused a 2.3-fold-greater release of apoptosis-specific mononucleosomes and oligonucleosomes than [ 177 Lu]DOTATOC at the final treatment time of 96 h (P 213 Bi]DOTATOC is therapeutically more effective in decreasing survival than is [ 177 Lu]DOTATOC in human pancreatic adenocarcinoma cells due to its comparatively higher RBE

  2. Applicability of a portable CdTe and NaI (Tl) spectrometer for activity measure

    International Nuclear Information System (INIS)

    Fernandes, Jaquiel Salvi

    2005-02-01

    In this work it was studied the application of an in situ gamma spectrometer (ROVER) of Amptek Inc., composed by a Cadmium Telluride detector (CdTe) of 3 mm x 3 mm x 1 mm and a 30 mm x 30 mm Sodium Iodide detector doped with Thallium [NaI (Tl)). The radioactive sources used were type pastille, sealed in aluminum and polyethylene, of 241 Am, 133 Ba, 152 Eu, 3 sources of 137 Cs and soil samples contaminated with 137 Cs. It was performed a factorial planning 2 3 to optimize the in situ spectrometry system. This way it was determined that the best temperature for CdTe crystal operation is -22, deg C, with Shaping Time of 3 μS and Rise Time Discrimination (RTD) with value 3. With the help of the certified radioactive sources, we determined the efficiency curve of the two detectors. The CdTe detector was positioned at the standard distance of 1 meter of the sources and also at 4.15 cm. The NaI (Tl) detector was also positioned at the standard distance of 1 meter of the sources and at 2.8 cm. Measures were performed to determine the Minimum Detectable Activity (MDA) for both detectors. For the pastille type sources, the 137 Cs MDA for the CdTe detector at 4.15 cm, analyzing the energy line of 32 keV, was 6 kBq and at 1 meter of the 137 Cs source, analyzing the line of 661.65 keV, the MDA was 67 kBq. For soil samples, CdTe detector at 4.15 cm presented a MDA of 693 kBq.kg-l for the line of 32 keV, and for the soil sample 7 Be content the MDA found was 2867 Bq.kg -1 at 4.15 cm. For the NaI (Tl) detector, analyzing the line of 661.65 keV, the 137 Cs MDA for pastille type source at 1 meter of distance was 7 kBq, and for soil sample at 2.8 cm the measured 137 Cs MDA was 71 Bq.kg -1 . For the soil sample 7 Be content, at 2.8 cm of the Nal (Tl) detector, the obtained MDA was 91 Bq.kg -1 . Due to the minimum detectable activities found for the two detectors, we concluded that the employed in situ gamma ray spectrometer system allows the quantification of 137 Cs and 7 Be

  3. The matrix effect study in the spectrographic analysis of rare earth elements. Pt. 1. The influence of Sn, Pb, Sb, Bi, Cu, Ag, Zn and Cd on the spectral lines intensity of Y, La, Ce, Pr, Nd and Sm in the current arc exciting between C-electrodes

    International Nuclear Information System (INIS)

    Wysocka-Lisek, J.; Paszkowska, B.; Mularczyk, K.

    1976-01-01

    In the beginning the influence of Sn, Pb, Sb, Bi, Cu, Ag, Zn and Cd on the light rare earth spectral lines using Ni as the internal standard, during the intermittent current arc excitation between C-electrodes was studied. On the basis of the spectral lines intensity measurements, it was stated that one may apply the addition of Ni as the internal standard by the quantitative determination of Sn, Pb, Sb, Bi, Zn and Cd in the light rare earth mixtures with one of the above. Also a great influence of the presence of the individually studied metal was observed on the spectral line intensity of rare earth elements and nickel. The differences of the thermo-chemical reactions nature between excited elements and the carbon of the electrodes may cause that influence. (author)

  4. Baseline quantity of 131I, 137Cs, 134Cs and 40K in urinary excretions from Thai people and internal exposure dose

    Science.gov (United States)

    Peekhunthod, D.; Bangvirunrak, J.; Sansakon, S.; Nukultham, A.; Pukkhaw, T.

    2017-06-01

    Today, sealed and unsealed radioactive materials have been used in Thailand for various purposes such as medical, agricultural and industrial applications. There is a growing trend in the use of radioactive materials. Moreover, neighboring countries are planning to construct and operate nuclear power plants. In case of nuclear power plant accidents, radioactive releases in environment and intakes into human body by inhalation and ingestion causing long term health effects. This research aims to determine the radiation baseline quantity of interested relevant radionuclides such as 131I, 137Cs, 134Cs as well as a natural radionuclide, 40K in urine samples of Thai people by gamma spectrometry. Two types of detectors (NaI and HpGe detectors) are calibrated by mixed radionuclide standards of 109Cd, 57Co, 133Ba, 54Mn, 137Cs and 60Co, (energy range from 88 to 1,331 keV). 720 urine samples are collected over a 24 hour period from Thai volunteers with the age older than 18 years old, who lived in eight locations of Thailand. To reduce the effect of geometric difference, 30 ml of urine samples are prepared for counting measurement and efficiency determination. The radiation baseline quantity of 131I, 137Cs, 134Cs and 40K in 30 ml of urine samples are 0.37±0.09, 0.63±0.13, 0.39±0.08 and 7.84±1.63 Bq, respectively. Based on the assumption of intake (50% of the intake by ingestion and 50% of the intake by inhalation), internal dose for members of public are assessed. The committed dose equivalent due to an intake of 131I, 137Cs, 134Cs and 40K are 2.36E-03±1.66-03, 1.15E-01±8.61E-02, 1.16E-01±7.77E-02, 9.44E-01±3.56E-01 mSv per year, respectively.

  5. Homogeneous Synthesis and Electroluminescence Device of Highly Luminescent CsPbBr3 Perovskite Nanocrystals.

    Science.gov (United States)

    Wei, Song; Yang, Yanchun; Kang, Xiaojiao; Wang, Lan; Huang, Lijian; Pan, Daocheng

    2017-03-06

    Highly luminescent CsPbBr 3 perovskite nanocrystals (PNCs) are homogeneously synthesized by mixing toluene solutions of PbBr 2 and cesium oleate at room temperature in open air. We found that PbBr 2 can be easily dissolved in nonpolar toluene in the presence of tetraoctylammonium bromide, which allows us to homogeneously prepare CsPbBr 3 perovskite quantum dots and prevents the use of harmful polar organic solvents, such as N,N-dimethylformamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone. Additionally, this method can be extended to synthesize highly luminescent CH 3 NH 3 PbBr 3 perovskite quantum dots. An electroluminescence device with a maximal luminance of 110 cd/m 2 has been fabricated by using high-quality CsPbBr 3 PNCs as the emitting layer.

  6. Circumsporozoite Protein-Specific Kd-Restricted CD8+ T Cells Mediate Protective Antimalaria Immunity in Sporozoite-Immunized MHC-I-Kd Transgenic Mice

    Directory of Open Access Journals (Sweden)

    Jing Huang

    2014-01-01

    Full Text Available Although the roles of CD8+ T cells and a major preerythrocytic antigen, the circumsporozoite (CS protein, in contributing protective antimalaria immunity induced by radiation-attenuated sporozoites, have been shown by a number of studies, the extent to which these players contribute to antimalaria immunity is still unknown. To address this question, we have generated C57BL/6 (B6 transgenic (Tg mice, expressing Kd molecules under the MHC-I promoter, called MHC-I-Kd-Tg mice. In this study, we first determined that a single immunizing dose of IrPySpz induced a significant level of antimalaria protective immunity in MHC-I-Kd-Tg mice but not in B6 mice. Then, by depleting various T-cell subsets in vivo, we determined that CD8+ T cells are the main mediator of the protective immunity induced by IrPySpz. Furthermore, when we immunized (MHC-I-Kd-Tg × CS-Tg F1 mice with IrPySpz after crossing MHC-I-Kd-Tg mice with PyCS-transgenic mice (CS-Tg, which are unable to mount PyCS-specific immunity, we found that IrPySpz immunization failed to induce protective antimalaria immunity in (MHC-I-Kd-Tg × CS-Tg F1 mice, thus indicating the absence of PyCS antigen-dependent immunity in these mice. These results indicate that protective antimalaria immunity induced by IrPySpz in MHC-I-Kd-Tg mice is mediated by CS protein-specific, Kd-restricted CD8+ T cells.

  7. First principles study of (Cd, Hg, In, Tl, Sn, Pb, As, Sb, Bi, Se) modified Pt(111), Pt(100) and Pt(211) electrodes as CO oxidation catalysts

    DEFF Research Database (Denmark)

    Tripkovic, Vladimir

    2015-01-01

    . The coverage dependence as a function of potential for ten different adatom species (Cd, Hg, In, Tl, Sn, Pb, As, Sb, Bi, Se) on bare and CO saturated Pt(111), Pt(100) and Pt(211) surfaces has been established by means of Density Functional Theory calculations. Most of the adatoms are very stable under standard......, given by the OH formation potentials from water, is dependent on the oxophilicity of the adatoms, and is found to scale almost inversely with the adatom stability. In electrolyte solutions saturated with CO, the stability reduces to roughly half of that on bare Pt surfaces. Irrespective of the CO...

  8. EPR and FTIR spectroscopic studies of MO-Al2O3-Bi2O3-B2O3-MnO2(M = Pb, Zn and Cd) glasses

    Science.gov (United States)

    Lalitha Phani, A. V.; Sekhar, K. Chandra; Chakradhar, R. P. S.; Narasimha Chary, M.; Shareefuddin, Md

    2018-03-01

    Glasses of the system (30-x)MO-xAl2O3-15Bi2O3-54.5B2O3-0.5MnO2 [M = Pb, Zn & Cd] (x = 0, 5, 10 & 15 mol%) were prepared by the normal melt quenching method. The amorphous nature of the prepared glasses was confirmed by the XRD studies. The EPR and FTIR studies were carried out at room temperature (RT). The EPR spectra exhibited three resonance signals at g ≈ 2.0 with a hyperfine structure, an absorption around g = 4.3 and a distinct shoulder at g = 3.3. Deconvoluted spectra were drawn for g ≈ 2.0 to resolve the six hyperfine lines. The electron paramagnetic resonance signal at g ≈ 2.0 indicates that the Mn2+ ions are in nearly perfectly octahedral symmetry. The low field signals at g = 3.3 and g = 4.3 are attributed to the Mn2+ ion which are in distorted rhombic symmetries. The hyperfine (HF) splitting constant (A) values suggested that the bonding between Mn2+ ions and its ligands is ionic in nature. The presence of BO3 and BO4 borate units, metal oxide cation units, Mn2+ and Bi-O bond vibrations in BiO3 units were noticed from the FTIR spectra.

  9. Prevention of renal allograft rejection in primates by blocking the B7/CD28 pathway

    NARCIS (Netherlands)

    Ossevoort, MA; Ringers, J; Kuhn, EM; Boon, L; Lorre, K; van den Hout, Y; Bruijn, JA; de Boer, H; Jonker, Margreet; de Waele, P

    1999-01-01

    Background. There is accumulating evidence that blockade of the costimulatory pathways offers a valid approach for immune suppression after solid organ transplantation. In this study, the efficacy of anti-CD86 and anti-CD86 monoclonal antibodies (mAbs) in combination with cyclosporine (CsA) to

  10. Antibodies derived from an enterotoxigenic Escherichia coli (ETEC) adhesin tip MEFA (multiepitope fusion antigen) against adherence of nine ETEC adhesins: CFA/I, CS1, CS2, CS3, CS4, CS5, CS6, CS21 and EtpA.

    Science.gov (United States)

    Nandre, Rahul M; Ruan, Xiaosai; Duan, Qiangde; Sack, David A; Zhang, Weiping

    2016-06-30

    Diarrhea continues to be a leading cause of death in children younger than 5 years in developing countries. Enterotoxigenic Escherichia coli (ETEC) is a leading bacterial cause of children's diarrhea and travelers' diarrhea. ETEC bacteria initiate diarrheal disease by attaching to host receptors at epithelial cells and colonizing in small intestine. Therefore, preventing ETEC attachment has been considered the first line of defense against ETEC diarrhea. However, developing vaccines effectively against ETEC bacterial attachment encounters challenge because ETEC strains produce over 23 immunologically heterogeneous adhesins. In this study, we applied MEFA (multiepitope fusion antigen) approach to integrate epitopes from adhesin tips or adhesive subunits of CFA/I, CS1, CS2, CS3, CS4, CS5, CS6, CS21 and EtpA adhesins and to construct an adhesin tip MEFA peptide. We then examined immunogenicity of this tip MEFA in mouse immunization, and assessed potential application of this tip MEFA for ETEC vaccine development. Data showed that mice intraperitoneally immunized with this adhesin tip MEFA developed IgG antibody responses to all nine ETEC adhesins. Moreover, ETEC and E. coli bacteria expressing these nine adhesins, after incubation with serum of the immunized mice, exhibited significant reduction in attachment to Caco-2 cells. These results indicated that anti-adhesin antibodies induced by this adhesin tip MEFA blocked adherence of the most important ETEC adhesins, suggesting this multivalent tip MEFA may be useful for developing a broadly protective anti-adhesin vaccine against ETEC diarrhea. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Molecular CsF{sub 5} and CsF{sub 2}{sup +}

    Energy Technology Data Exchange (ETDEWEB)

    Rogachev, Andrey Yu. [Illinois Institute of Technology, IL (United States). Dept. of Biological and Chemical Sciences; Miao, Mao-sheng [California State Univ., Northridge, CA (United States). Dept. of Chemistry and Biochemistry; Beijing Computational Science Research Center (China); Merino, Gabriel [Centro de Investigacion y de Estudios Avanzados, Unidad Merida (Mexico). Dept. de Fisica Aplicada; Hoffmann, Roald [Cornell Univ., Ithaca, NY (United States). Dept. of Chemistry and Chemical Biology

    2015-07-06

    D{sub 5h} star-like CsF{sub 5}, formally isoelectronic with known XeF{sub 5}{sup -} ion, is computed to be a local minimum on the potential energy surface of CsF{sub 5}, surrounded by reasonably large activation energies for its exothermic decomposition to CsF + 2F{sub 2}, or to CsF{sub 3} (three isomeric forms) + F{sub 2}, or for rearrangement to a significantly more stable isomer, a classical Cs{sup +} complex of F{sub 5}{sup -}. Similarly the CsF{sub 2}{sup +} ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

  12. Tetravalent anti-CD20/CD3 bispecific antibody for the treatment of B cell lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chia-Yen; Chen, Gregory J.; Tai, Pei-Han; Yang, Yu-Chen [Institute of Biologics, Development Center for Biotechnology, New Taipei City, Taiwan (China); Hsu, Yu-Shen, E-mail: yshsu@advagene.com.tw [Laboratory of Biopharmaceutical Research, Advagene Biopharma, Taipei, Taiwan (China); Chang, Mingi, E-mail: mingi.chang@advagene.com.tw [Laboratory of Biopharmaceutical Research, Advagene Biopharma, Taipei, Taiwan (China); Hsu, Chuan-Lung, E-mail: fabio@dcb.org.tw [Institute of Biologics, Development Center for Biotechnology, New Taipei City, Taiwan (China)

    2016-05-13

    Bispecific antibodies (bsAbs) are second generation antibodies for therapeutic application in immunotherapy. One of the major strategies of the bsAb platform is the recruitment of immune effector T cells by incorporating an anti-CD3 domain. A bispecific T-cell engager (BiTE), with one end having an affinity for CD3 and the other end with affinity for CD19, has been approved in the US and Europe for the treatment of acute lymphoblastic leukemia. However, due to their small size and lack of Fc region, these single-chain variable fragment (scFv) bsAbs have short half-lives in vivo. Additionally, poor solubility, structural instability, and low production yields have also become major challenges in the bulk production process. To overcome these challenges, we have engineered a tetravalent bsAb with bivalent binding specificity for the CD20 and CD3 antigen in an immunoglobulin G (IgG) format. The fusion of the anti-CD3 scFvs to the CD20 antibody via a linker-hinge domain (LHD) results in improved antibody stabilization and properties. Here we demonstrate this antibody's highly efficient cancer cell elimination in a dose-dependent manner in a CD20-expressing B lymphoblastoid cell line in vitro. Our data suggest the potential clinical application of this bsAb for the treatment of CD20-expressing B cell malignancies. - Highlights: • A bispecific antibody (bsAb) can increase immunotherapeutic efficacy. • A tetravalent bsAb with binding specificity for the CD20 and CD3 antigens is proposed. • A linker-hinge domain (LHD) within the bsAb results in improved antibody properties.

  13. Water-assisted size and shape control of CsPbBr3 perovskite nanocrystals

    International Nuclear Information System (INIS)

    Zhang, Xiaoyu; Bai, Xue; Wu, Hua; Zhang, Xiangtong; Sun, Chun; Zhang, Yu; Zhang, Wei; Zheng, Weitao; Yu, William W.; Rogach, Andrey L.

    2018-01-01

    Lead-halide perovskites are well known to decompose rapidly when exposed to polar solvents, such as water. Contrary to this common-place observation, we have found that through introducing a suitable minor amount of water into the reaction mixture, we can synthesize stable CsPbBr 3 nanocrystals. The size and the crystallinity, and as a result the band gap tunability of the strongly emitting CsPbBr 3 nanocrystals correlate with the water content. Suitable amounts of water change the crystallization environment, inducing the formation of differently shaped perovskites, namely spherical NCs, rectangular nanoplatelets, or nanowires. Bright CsPbBr 3 nanocrystals with the photoluminescence quantum yield reaching 90 % were employed for fabrication of inverted hybrid inorganic/organic light-emitting devices, with the peak luminance of 4428 cd m -2 and external quantum yield of 1.7 %. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Synthesis of the phase with T sub c =110 K in Bi(Pb)-Sr-Ca-Cu-O superconducting ceramics. Sintez fazy T sub c =110 K sverkhprovodyashchej keramiki sostava Bi(Pb)-Sr-Ca-Cu-O

    Energy Technology Data Exchange (ETDEWEB)

    Dubovitskij, A V; Makarov, E F; Makova, M K; Merzhanov, V A; Topnikov, V N [AN SSSR, Moscow (USSR). Inst. Khimicheskoj Fiziki

    1991-05-01

    Synthesis of 110 K single-phase bismuth ceramics (BiPb){sub 2}Sr{sub 2}Ca{sub n-1}Cu{sub n}O{sub x} was conducted in narrow temperature and time range. Diffusion of bismuth ions is proposed to be the decisive factor of synthesis of bismuth ceramics. The diffusion depends on prehistory of basic burden preparation and on its dispersivity and homogeneity in particluar. Optimal time of synthesis for lead doped ceramics of 2223 composition, synthesized from initial nitrate components, is equal to 65 h at 850 deg C. The role of Pb{sup 2+} ions is probably reduced to decrease of diffusion mobility of Bi{sup 3+} ions over the bismuth sublattice. Ceramics doping with CdO and CdCl{sub 2} compounds instead of lead stabilizes superconductivity in bismuth ceramics, but with worth superconducting parameters.

  15. Analysis of 137Cs radionuclides activities in Cs-zeolite using gamma spectrometry

    International Nuclear Information System (INIS)

    Noviarty; Ginting, Aslina Br; Anggraini, Dian; Rosika K

    2013-01-01

    137 Cs Radionuclide activity analysis has been carried out. The objective is to determine the activity of the 137 Cs radionuclide in Cs-zeolite are packaged in the form of point source. Analysis of 137 Cs Radionuclide activities in Cs zeolite samples was determined by measuring intensity of the isotope 137 Cs gamma energy at 661.7 keV use-y spectrometer. Before measurement the sample, was first carried out measurements of 137 Cs radionuclide in certified point standards from Amersham, to determine the efficiency value. Result the standard sample measurement obtained the efficiency value of 43.98%. Efficiency values obtained are used in the calculation of sample activity. On the measurement of the intensity of the sample obtained results dose rate 196.4537 cps with a standard deviation of 0.5274. By using standard measurement efficiency values obtained by the calculation of the average activity of the radionuclide 137 Cs in Cs-zeolite 524.9082 Bq. Deviation measurements were below 5% (0.27% ) so that the analysis of the activity of radionuclide 137 Cs in Cs-zeolite samples using gamma spectrometer can be accepted with a 95% confidence level. (author)

  16. Prolonged skin graft survival by administration of anti-CD80 monoclonal antibody with cyclosporin A

    NARCIS (Netherlands)

    Ossevoort, MA; Lorre, K; Boon, L; van den Hout, Y; de Boer, M; De Waele, P; Jonker, M; VandeVoorde, A

    Costimulation via the B7/CD28 pathway is an important signal for the activation of T cells. Maximal inhibition of T-cell activation and the induction of alloantigen-specific nonresponsiveness in vitro was achieved using anti-CD80 monoclonal antibody (mAb) in combination with cyclosporin A (CsA).

  17. A New Immunosuppressive Molecule Emodin Induces both CD4+FoxP3+ and CD8+CD122+ Regulatory T Cells and Suppresses Murine Allograft Rejection

    Directory of Open Access Journals (Sweden)

    Feifei Qiu

    2017-11-01

    Full Text Available Due to vigorous alloimmunity, an allograft is usually rejected without any conventional immunosuppressive treatment. However, continuous global immunosuppression may cause severe side effects, including tumors and infections. Mounting evidence has shown that cyclosporine (CsA, a common immunosuppressant used in clinic, impedes allograft tolerance by dampening regulatory T cells (Tregs, although it inhibits allograft rejection at the same time. Therefore, it is necessary to seek an alternative immunosuppressive drug that spares Tregs with high efficiency in suppression but low toxicity. In this study, we investigated the capacity of emodin, an anthraquinone molecule originally extracted from certain natural plants, to prolong transplant survival in a mouse model and explored the cellular and molecular mechanisms underlying its action. We found that emodin significantly extended skin allograft survival and hindered CD3+ T cell infiltration in the allograft, accompanied by an increase in CD4+Foxp3+ and CD8+CD122+ Treg frequencies and numbers but a reduction in effector CD8+CD44highCD62Llow T cells in recipient mice. Emodin also inhibited effector CD8+ T cells proliferation in vivo. However, CD4+CD25+, but not CD8+CD122+, Tregs derived from emodin-treated recipients were more potent in suppression of allograft rejection than those isolated from control recipients, suggesting that emodin also enhances the suppressive function of CD4+CD25+ Tregs. Interestingly, depleting CD25+ Tregs largely reversed skin allograft survival prolonged by emodin while depleting CD122+ Tregs only partially abrogated the same allograft survival. Furthermore, we found that emodin hindered dendritic cell (DC maturation and reduced alloantibody production posttransplantation. Finally, we demonstrated that emodin inhibited in vitro proliferation of T cells and blocked their mTOR signaling as well. Therefore, emodin may be a novel mTOR inhibitor that suppresses alloimmunity by

  18. Photoinduced interaction of CdSe quantum dot with coumarins

    Energy Technology Data Exchange (ETDEWEB)

    El-Kemary, Maged, E-mail: elkemary@sci.kfs.edu.eg [Nanotechnology Center, Faculty of Science, Kafrelsheikh University, 33516 Kafrelsheikh (Egypt); Gaber, Mohamed; El-Sayed, Y.S. [Chemistry Department, Faculty of Science, University of Tanta, Tanta (Egypt); Gheat, Youssef [Nanotechnology Center, Faculty of Science, Kafrelsheikh University, 33516 Kafrelsheikh (Egypt); Chemistry Department, Faculty of Science, University of Tanta, Tanta (Egypt)

    2015-03-15

    Cadmium selenide (CdSe) quantum dots (QDs) were synthesized with a cubic shape having a diameter of ∼5.24 nm. The prepared CdSe QDs were characterized by using UV–visible, Fourier transform infrared (FTIR), powder X-ray diffraction (XRD) and transmission electron microscope (TEM) measurements. The UV–visible absorption spectra indicate that the optical band gap of CdSe QDs is ∼622 nm and the peak shift can mainly be due to the quantum size effects. The fluorescence decay kinetics for the synthesized QDs was followed by time-resolved fluorescence spectroscopy, and the spectra were analyzed in regard to a bi-exponential model to identify two lifetime values, that is, shorter-lifetime 1.37 ns (55%) and longer-lifetime 6.58 ns (45%). The interaction of coumarin 152 (C152) and coumarin 153 (C153) with QDs surface brings about further considerable changes in the absorption and fluorescence patterns. The calculated binding constant from fluorescence quenching method matches well with that determined from the absorption spectral changes. The static quenching mechanism was confirmed by large magnitude of K{sub SV} and unaltered fluorescence lifetime. - Highlights: • CdSe QDs were synthesized with a cubic shape having a diameter of ∼5.24 nm. • The UV–visible absorption spectra indicate that the optical band gap of CdSe QDs is ∼622 nm. • Picosecond fluorescence measurements of the QDs suggest bi-exponential function. • The calculated binding constant from fluorescence quenching method matches well with that determined from the absorption spectral changes. • The static quenching mechanism was confirmed by large magnitude of K{sub SV} and unaltered fluorescence lifetime.

  19. 'Wash-out' of Cs-134 and Cs-137 from river sediment; 'Ispiranja' Cs-134 i Cs-137 iz recnog sedimenta

    Energy Technology Data Exchange (ETDEWEB)

    Skrbic, Z; Conkic, Lj; Bikit, I; Veskovic, M; Slivka, J; Marinkov, L [Institut za Fiziku, Novi Sad Univ. (Yugoslavia)

    1988-07-01

    Natural elimination and 'wash out' period of the Cs-134 and Cs-137 from the river sediment has been investigated. Obtained results suggest the possibility to describe these processes by exponential low and determination of the corresponding half lives. (author)

  20. Gamma-ray mutagenesis studies in a new human-hamster hybrid, A(L)CD59(+/-), which has two human chromosomes 11 but is hemizygous for the CD59 gene

    Science.gov (United States)

    Kraemer, S. M.; Vannais, D. B.; Kronenberg, A.; Ueno, A.; Waldren, C. A.; Chatterjee, A. (Principal Investigator)

    2001-01-01

    Kraemer, S. M., Vannais, D. B., Kronenberg, A., Ueno, A. and Waldren, C. A. Gamma-Ray Mutagenesis Studies in a New Human-Hamster Hybrid, A(L)CD59(+/-), which has Two Human Chromosomes 11 but is Hemizygous for the CD59 Gene. Radiat. Res. 156, 10-19 (2001).We have developed a human-CHO hybrid cell line, named A(L)CD59(+/-), which has two copies of human chromosome 11 but is hemizygous for the CD59 gene and the CD59 cell surface antigen that it encodes. Our previous studies used the A(L) and A(L)C hybrids that respectively contain one or two sets of CHO chromosomes plus a single copy of human chromosome 11. The CD59 gene at 11p13.5 and the CD59 antigen encoded by it are the principal markers used in our mutagenesis studies. The hybrid A(L)CD59(+/-) contains two copies of human chromosome 11, only one of which carries the CD59 gene. The incidence of CD59 (-) mutants (formerly called S1(-)) induced by (137)Cs gamma rays is about fivefold greater in A(L)CD59(+/-) cells than in A(L) cells. Evidence is presented that this increase in mutant yield is due to the increased induction of certain classes of large chromosomal mutations that are lethal to A(L) cells but are tolerated in the A(L)CD59(+/-) hybrid. In addition, significantly more of the CD59 (-) mutants induced by (137)Cs gamma rays in A(L)CD59(+/-) cells display chromosomal instability than in A(L) cells. On the other hand, the yield of gamma-ray-induced CD59 (-) mutants in A(L)CD59(+/-) cells is half that of the A(L)C hybrid, which also tolerates very large mutations but has only one copy of human chromosome 11. We interpret the difference in mutability as evidence that repair processes involving the homologous chromosomes 11 play a role in determining mutant yields. The A(L)CD59(+/-) hybrid provides a useful new tool for quantifying mutagenesis and shedding light on mechanisms of genetic instability and mutagenesis.

  1. Uptake and distribution of 137Cs, stable Cs and K in rice plants

    International Nuclear Information System (INIS)

    Tsukada, Hirofumi; Hasegawa, Hidenao

    2003-01-01

    The uptake and distributions of 137 Cs, stable Cs and K were determined for rice plant components, including polished rice, rice bran, hulls, leaves, stems, and roots. The distribution of 137 Cs in polished rice and rice bran was similar to that of stable Cs, while that of K was different. The concentration ratios of Cs/K in leaves increased in older leaf blade positions, which meant that the translocation rate of stable Cs, was slower than that of K. At harvest the dry weight of polished rice accounted for 34% of the entire rice plant, while the distributions of stable Cs in the polished rice and the non-edible parts were 7 and 93%, respectively. These findings suggest that the transfer and distribution of stable Cs in rice plants are different from those of K, and the behavior of stable Cs provides a useful analogue in predicting the fate of 137 Cs in an agricultural environment. (author)

  2. 135Cs activity and 135Cs/137Cs atom ratio in environmental samples before and after the Fukushima Daiichi Nuclear Power Plant accident.

    Science.gov (United States)

    Yang, Guosheng; Tazoe, Hirofumi; Yamada, Masatoshi

    2016-04-07

    (135)Cs/(137)Cs is a potential tracer for radiocesium source identification. However, due to the challenge to measure (135)Cs, there were no (135)Cs data available for Japanese environmental samples before the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. It was only 3 years after the accident that limited (135)Cs values could be measured in heavily contaminated environmental samples. In the present study, activities of (134)Cs, (135)Cs, and (137)Cs, along with their ratios in 67 soil and plant samples heavily and lightly contaminated by the FDNPP accident were measured by combining γ spectrometry with ICP-MS/MS. The arithmetic means of the (134)Cs/(137)Cs activity ratio (1.033 ± 0.006) and (135)Cs/(137)Cs atom ratio (0.334 ± 0.005) (decay corrected to March 11, 2011), from old leaves of plants collected immediately after the FDNPP accident, were confirmed to represent the FDNPP derived radiocesium signature. Subsequently, for the first time, trace (135)Cs amounts before the FDNPP accident were deduced according to the contribution of global and FDNPP accident-derived fallout. Apart from two soil samples with a tiny global fallout contribution, contributions of global fallout radiocesium in other soil samples were observed to be 0.338%-52.6%. The obtained (135)Cs/(137)Cs database will be useful for its application as a geochemical tracer in the future.

  3. Validation of CsNaIF data evaluation software. Final report on task FIN A940 on the Finnish support programme to IAEA safeguards

    International Nuclear Information System (INIS)

    Kaartinen, J.

    1996-07-01

    A new computer programme, called CsNaIF, which calculates the area of 137 Cs peak in spent fuel spectra has been developed for IAEA. This programme has been tested and evaluated in this report. Evaluation has been made by calculating different types of SFAT spectra (NaI- and CdTe-SFAT) with the validated software and with a research grade gamma spectroscopy software, SAMPO 90. Obtained results, mainly 137 Cs peak areas and their errors, have been compared and perceived differences have been reported. Also some recommendations of the usability of CsNaIF programme have been made for IAEA. (orig.) (4 refs.)

  4. Activity standardization of 134Cs and 137Cs

    International Nuclear Information System (INIS)

    Sochorová, Jana; Auerbach, Pavel

    2014-01-01

    The paper presents the results from a primary standardization of 137 Cs using two independent methods – efficiency tracing using PC-NaI coincidence and the TDCR method. The nuclides 60 Co and 134 Cs were used as the tracers. Primary standardization of the 134 Cs is also discussed. The efficiency extrapolation was carried out by measuring samples of varying mass and using the wet extrapolation method. The results obtained are in good agreement; the differences did not exceed 0.5%. The advantages, pitfalls and also possibilities for improvement of the procedures are discussed

  5. Determination of Cs-134 and Cs-137 rain water samples

    International Nuclear Information System (INIS)

    Lima, M.F.; Mazzilli, B.

    1988-01-01

    In order to setting an environmental monitoring program at IPEN, was developed a fast and simple methodology for concentration of Cs-134 and Cs-137 in rain water. This procedure consists in the precipitation of cesium and others cathions of its family (NH 4 + , K + and Rb + ) by ammonium molybdophosphate. The measures of the desintegration rates of Cs-134 and Cs-137 was done by gamma spectrometry in a Ge(Li) detector. After setting up the ideal experimental conditions, the procedure was used to analyze four samples of rain water. (author) [pt

  6. ZnO/CdS bi-layer nanostructures photoelectrode for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Dalal, Paresh V., E-mail: paresh10dalal@gmail.com [Physics Research Lab, Shri V. S. Naik Arts, Commerce and Science College, Raver-425508 (M. S.) (India); Deshpande, Milind P., E-mail: vishwadeshpande@yahoo.co.in [Department of Physics, Sardar Patel University, Vallabh Vidyanagar-388120 (Gujarat) (India); Solanki, Bharat G., E-mail: bhrt.solanki17@gmail.com; Soni, Saurabh S., E-mail: soni-b21@yahoo.co.in [Department of Chemistry, Sardar Patel University, Vallabh Vidyanagar-388120 (Gujarat) (India)

    2016-05-06

    Simple chemical deposition method for the synthesis of ZnO/CdS bilayer photoelectrode on fluorine doped tin oxide (FTO) coated glass substrate in aqueous medium at low temperature (< 373K) is described. The different preparative parameters such as deposition time, bath temperature, concentration of precursor solution and, pH of the bath etc. were optimized. Nanograined ZnO was deposited on FTO coated glass substrates by dip-coating method, whereas CdS nanorods were successfully synthesized on pre-deposited ZnO film by Chemical Bath Deposition (CBD) method. The Photovoltaic properties of FTO/ZnO/CdS bilayer photo electrodes were also studied. A maximum short circuit current density of 9.1 mA cm-2 and conversion efficiency 1.05% are observed for ZnO/CdS-10min. Layer, which supports fast electron injection kinetics due to hetero structured nanorod, while minimum values of 0.53mA cm-2 and 0.01% respectively are observed for only ZnO deposited layer.

  7. Determination of {sup 135}Cs and {sup 137}Cs in environmental samples: A review

    Energy Technology Data Exchange (ETDEWEB)

    Russell, B.C., E-mail: ben.russell@npl.co.uk [GAU-Radioanalytical, Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH (United Kingdom); National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW (United Kingdom); Croudace, Ian W.; Warwick, Phil E. [GAU-Radioanalytical, Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH (United Kingdom)

    2015-08-26

    Radionuclides of caesium are environmentally important since they are formed as significant high yield fission products ({sup 135}Cs and {sup 137}Cs) and activation products ({sup 134}Cs and {sup 136}Cs) during nuclear fission. They originate from a range of nuclear activities such as weapons testing, nuclear reprocessing and nuclear fuel cycle discharges and nuclear accidents. Whilst {sup 137}Cs, {sup 134}Cs and {sup 136}Cs are routinely measurable at high sensitivity by gamma spectrometry, routine detection of long-lived {sup 135}Cs by radiometric methods is challenging. This measurement is, however, important given its significance in long-term nuclear waste storage and disposal. Furthermore, the {sup 135}Cs/{sup 137}Cs ratio varies with reactor, weapon and fuel type, and accurate measurement of this ratio can therefore be used as a forensic tool in identifying the source(s) of nuclear contamination. The shorter-lived activation products {sup 134}Cs and {sup 136}Cs have a limited application but provide useful early information on fuel irradiation history and have importance in health physics. Detection of {sup 135}Cs (and {sup 137}Cs) is achievable by mass spectrometric techniques; most commonly inductively coupled plasma mass spectrometry (ICP-MS), as well as thermal ionisation (TIMS), accelerator (AMS) and resonance ionisation (RIMS) techniques. The critical issues affecting the accuracy and detection limits achievable by this technique are effective removal of barium to eliminate isobaric interferences arising from {sup 135}Ba and {sup 137}Ba, and elimination of peak tailing of stable {sup 133}Cs on {sup 135}Cs. Isobaric interferences can be removed by chemical separation, most commonly ion exchange chromatography, and/or instrumental separation using an ICP-MS equipped with a reaction cell. The removal of the peak tailing interference is dependent on the instrument used for final measurement. This review summarizes and compares the analytical procedures

  8. Chemical Bath Deposition and Characterization of CdS layer for CZTS Thin Film Solar Cell

    OpenAIRE

    Kamal, Tasnim; Parvez, Sheikh; Matin, Rummana; Bashar, Mohammad Shahriar; Hossain, Tasnia; Sarwar, Hasan; Rashid, Mohammad Junaebur

    2016-01-01

    CZTS is a new type of an absorber and abundant materials for thin film solar cells (TFSC). Cadmium sulfide (CdS) is the n-type buffer layer of it with band gap of 2.42 eV. Cadmium sulfide (CdS) buffer layer of CZTS solar cell was deposited on soda-lime glass substrates by the Chemical Bath Deposition(CBD) method, using anhydrous Cadmium chloride(CdCl_2) and Thiourea (CS(NH_2)_2). Deposition of CdS using CBD is based on the slow release of Cd^ ions and S^ ions in an alkaline bath which is achi...

  9. Bi-Force

    DEFF Research Database (Denmark)

    Sun, Peng; Speicher, Nora K; Röttger, Richard

    2014-01-01

    of pairwise similarities. We first evaluated the power of Bi-Force to solve dedicated bicluster editing problems by comparing Bi-Force with two existing algorithms in the BiCluE software package. We then followed a biclustering evaluation protocol in a recent review paper from Eren et al. (2013) (A...... comparative analysis of biclustering algorithms for gene expressiondata. Brief. Bioinform., 14:279-292.) and compared Bi-Force against eight existing tools: FABIA, QUBIC, Cheng and Church, Plaid, BiMax, Spectral, xMOTIFs and ISA. To this end, a suite of synthetic datasets as well as nine large gene expression...

  10. Lesional CD4+ IFN-γ+ cytotoxic T lymphocytes in IgG4-related dacryoadenitis and sialoadenitis

    Science.gov (United States)

    Maehara, Takashi; Mattoo, Hamid; Ohta, Miho; Mahajan, Vinay S; Moriyama, Masafumi; Yamauchi, Masaki; Drijvers, Jefte; Nakamura, Seiji; Stone, John H; Pillai, Shiv S

    2017-01-01

    Objectives IgG4-related disease (IgG4-RD) is a chronic, systemic, inflammatory condition of unknown aetiology. We have recently described clonally expanded circulating CD4+ cytotoxic T lymphocytes (CTLs) in IgG4-RD that infiltrate affected tissues where they secrete interleukin (IL)-1β and transforming growth factor -β1 (TGF-β1). In this study, we sought to examine the role of CD4+ CTLs in the pathogenesis of IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS) and to determine whether these cells secrete interferon-gamma (IFN-γ) at lesional sites. Methods Salivary glands of 25 patients with IgG4-DS, 22 patients with Sjögren’s syndrome (SS), 12 patients with chronic sialoadenitis (CS) and 12 healthy controls were analysed in this study. Gene expression analysis was performed on submandibular glands (SMGs) from five patients with IgG4-DS, three with CS and three healthy controls. Infiltrating CD4+ CTLs were examined by quantitative multicolour imaging in tissue samples from 20 patients with IgG4-DS, 22 patients with SS, 9 patients with CS and 9 healthy controls. Results In IgG4-DS tissues, nine genes associated with CD4+ CTLs were overexpressed. The expression of granzyme A (GZMA) mRNA was significantly higher in samples from patients with IgG4-RD compared with corresponding tissues from SS and healthy controls. Quantitative imaging showed that infiltrating CD4+ GZMA+ CTLs were more abundant in patients with IgG4-DS than in the other groups. The ratio of CD4+GZMA+ CTLs in SMGs from patients with IgG4-DS correlated with serum IgG4 concentrations and the number of affected organs. A large fraction of CD4+GZMA+ CTLs in SMGs from patients with IgG4-DS secreted IFN-γ. Conclusions The pathogenesis of IgG4-DS is associated with tissue infiltration by CD4+GZMA+ CTLs that secrete IFN-γ. PMID:27358392

  11. Bi∼3.785Cd∼3.575Cu∼1.5(PO4)3.5O5.5, a new arrangement of double (n=2) and triple (n=3) [M4Bi2n-2O2n]x+ polycationic ribbons in the bismuth-transition metal oxy-phosphate series

    International Nuclear Information System (INIS)

    Colmont, Marie; Huve, Marielle; Abraham, Francis; Mentre, Olivier

    2004-01-01

    This work is dedicated to investigation of new disordered bismuth-containing oxy-phosphates compounds with an original structure type. As previously observed in this series, they are formed of [M 4 Bi 2n-2 O 2n ] x+ polycationic ribbons of width n O(Bi,M) 4 tetrahedra, surrounded by PO 4 groups. In the new crystal structure type, double (=D), triple (=T) and tunnels (=t) alternate along a common axis obeying the TtDtTtDt/TTtTTt sequence in respect to a nomenclature previously described and recalled in this work. The existence this new polymorph has first been detected by electron diffraction in a multi-phased sample. Then, the crystal structure type, i.e., the TtDtTtDt/TTtTTt sequence, has been deduced from HREM images help to a contrast-interpreting code available for these series of polycations-formed compounds. The subsequent compounds formulation leads to a number of new materials that verify the general formula: [Bi 2 (Bi,M) 4 O 4 ] 2 [Bi 4 (Bi,M) 4 O 6 ] 6 (PO 4 ) 28 M x , with x= 2+ , Cd 2+ cations. Single crystals of the nominal [O6Bi 4.57 Cd 3.43 ] 4 +8.57 [O 6 Bi 4 Cd 4 ] 2 +8 [O 4 Bi 2 Cd 3.56 Cu 0.44 ] 2 +6 (PO 4 ) 28 Cu 10.86 have been prepared in a further stage and confirms the predicted crystal structure, Bi ∼3.785 Cd ∼3.575 Cu ∼1.5 (PO 4 ) 3.5 O 5.5 , a=11.506(8)A, b=5.416(4)A, c=53.94 (4)A, β=90.10(1) o , RF=0.0835, RwF=0.0993, SG=A2/m, Z=8. As already observed for other elements of this family such as Bi ∼1.2 M ∼1.2 O 1.5 (PO 4 ), Bi ∼6.2 Cu ∼6.2 O 8 (PO 4 ) 5 or Bi ∼3 Cd ∼3.72 M ∼1.28 O 5 (PO 4 ) 3 (M=Cu, Co, Zn), this compound shows an additional example of PO 4 disorder due to the presence of mixed Bi 3+ /M 2+ sites at the edges of ribbons. The origin and consequence of this so-called disorder mostly occurring on PO 4 configurations is intensively discussed and has been characterized by infrared spectroscopy and by neutron diffraction on similar compounds. It is noticeable that the great number of antagonist PO 4

  12. Sem-EDAX'S Application For Characterization Of Superconductor Material Of (Bi,Pb)-Sr-Ca-Cu-O

    International Nuclear Information System (INIS)

    Handayani, Ari; Wuryanto; Prambudi, Bambang

    1996-01-01

    The microstructure and composition analysis of superconductor material of (Bi,Pb)-Sr-Ca-Cu-O which were synthesized by two different processes (CA and CD Process) by varying the sintering time, i.e. 20,60 and 100 hours were done by using SEM-EDAX method. The standard sample of superconductor material of Bi-Sr-Ca-Cu-O with 1112, 2212 and 2223 phase from Stream has been used for comparison, At 25 kV, the composition analysis showed that, at 20 and 60 hours of sintering, a mixture of phases existed while 100 hours of sintering resulted in a phase close to phase 2223. The result of microstructure observation showed significant differences. At synthesized CA process, 100 hours of sintering gives bigger and clearer platelet microstructure shape than that given by 20 and 60 hours of sintering. Also from the synthesized CD process, the 60 and 100 hours of sintering gives bigger and clearer platelet microstructure shape than that given by the 20 hours of sintering

  13. Water-assisted size and shape control of CsPbBr{sub 3} perovskite nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaoyu [State Key Laboratory on Integrated Optoelectronics and College of Electronic Science and Engineering, Jilin University, Changchun (China); Department of Materials Science, Key Laboratory of Mobile Materials MOE, State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun (China); Bai, Xue; Wu, Hua; Zhang, Xiangtong; Sun, Chun; Zhang, Yu [State Key Laboratory on Integrated Optoelectronics and College of Electronic Science and Engineering, Jilin University, Changchun (China); Zhang, Wei; Zheng, Weitao [Department of Materials Science, Key Laboratory of Mobile Materials MOE, State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun (China); Yu, William W. [State Key Laboratory on Integrated Optoelectronics and College of Electronic Science and Engineering, Jilin University, Changchun (China); Department of Chemistry and Physics, Louisiana State University, Shreveport, LA (United States); Rogach, Andrey L. [Department of Materials Science and Engineering, and Centre for Functional Photonics (CFP), City University of Hong Kong, Kowloon (China)

    2018-03-19

    Lead-halide perovskites are well known to decompose rapidly when exposed to polar solvents, such as water. Contrary to this common-place observation, we have found that through introducing a suitable minor amount of water into the reaction mixture, we can synthesize stable CsPbBr{sub 3} nanocrystals. The size and the crystallinity, and as a result the band gap tunability of the strongly emitting CsPbBr{sub 3} nanocrystals correlate with the water content. Suitable amounts of water change the crystallization environment, inducing the formation of differently shaped perovskites, namely spherical NCs, rectangular nanoplatelets, or nanowires. Bright CsPbBr{sub 3} nanocrystals with the photoluminescence quantum yield reaching 90 % were employed for fabrication of inverted hybrid inorganic/organic light-emitting devices, with the peak luminance of 4428 cd m{sup -2} and external quantum yield of 1.7 %. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Scavenger Receptor Class B, Type I, a CD36 Related Protein in Macrobrachium nipponense: Characterization, RNA Interference, and Expression Analysis with Different Dietary Lipid Sources

    Directory of Open Access Journals (Sweden)

    Zhili Ding

    2016-01-01

    Full Text Available The scavenger receptor class B, type I (SR-BI, is a member of the CD36 superfamily comprising transmembrane proteins involved in mammalian and fish lipid homeostasis regulation. We hypothesize that this receptor plays an important role in Macrobrachium nipponense lipid metabolism. However, little attention has been paid to SR-BI in commercial crustaceans. In the present study, we report a cDNA encoding M. nipponense scavenger receptor class B, type I (designated as MnSR-BI, obtained from a hepatopancreas cDNA library. The complete MnSR-BI coding sequence was 1545 bp, encoding 514 amino acid peptides. The MnSR-BI primary structure consisted of a CD36 domain that contained two transmembrane regions at the N- and C-terminals of the protein. SR-BI mRNA expression was specifically detected in muscle, gill, ovum, intestine, hepatopancreas, stomach, and ovary tissues. Furthermore, its expression in the hepatopancreas was regulated by dietary lipid sources, with prawns fed soybean and linseed oils exhibiting higher expression levels. RNAi-based SR-BI silencing resulted in the suppression of its expression in the hepatopancreas and variation in the expression of lipid metabolism-related genes. This is the first report of SR-BI in freshwater prawns and provides the basis for further studies on SR-BI in crustaceans.

  15. Crystallization kinetics, optical and dielectric properties of Li2OṡCdOṡBi2O3ṡSiO2 glasses

    Science.gov (United States)

    Rani, Saroj; Sanghi, Sujata; Ahlawat, Neetu; Agarwal, Ashish

    2015-10-01

    Crystallization kinetics, optical absorption and electrical behavior of lithium cadmium silicate glasses with different amount of bismuth oxide were investigated using non-isothermal crystallization approach, UV-VIS-NIR spectroscopy and impedance spectroscopy, respectively. These glasses were synthesized by normal melt quenching technique. Variation in physical properties, viz. density, molar volume with Bi2O3:SiO2 ratio were related to the structural changes occurring in the glasses. The glass transition temperature (Tg), crystalline peak temperature (Tp) and melting temperature (Tm) of these glasses were determined using differential scanning calorimeter at various heating rates. The dependence of Tg and Tp on heating rate has been used for the determination of the activation energy of glass transition and crystallization. Thermal stability parameters have revealed high stability of the glass prepared with 40 mol% of Bi2O3 content. The crystallization kinetics for the glasses was studied by using the Kissinger and modified Ozawa equations. Appearance of a sharp cut-off and a wide and reasonable transmission in VIS-NIR region makes these glasses suitable for IR transmission window. The cut-off wavelength, optical band gap and Urbach's energy have been analyzed and discussed in terms of changes in the glass structure. By analyzing the impedance spectra, the ac and dc conductivities, activation energy for dc conduction (Edc) and for relaxation (EM″) were calculated. The results obtained from dc conductivity confirm the network forming role of Cd2+ ion in the glasses. The scaling of the conductivity spectra has been used to interpret the temperature dependence of the relaxation dynamics. The observed conductivity spectra follows power law with exponent 's' which decreases with temperature and satisfies the correlated barrier hopping (CBH) model. The perfect overlying of normalized plots of electrical modulus on a single 'master curve' depicts temperature as well as

  16. Anodic stripping voltammetric determination of traces of Pb(II) and Cd(II) using a glassy carbon electrode modified with bismuth nanoparticles

    International Nuclear Information System (INIS)

    Yang, Die; Wang, Liang; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravi

    2014-01-01

    We report on a glassy carbon electrode modified with bismuth nanoparticles (NanoBiE) for the simultaneous determination Pb 2+ and Cd 2+ by anodic stripping voltammetry. Operational parameters such as bismuth nanoparticles labelling amount, deposition potential, deposition time and stripping parameters were optimized with respect to the determination of Pb 2+ and Cd 2+ in 0.1 M acetate buffer solution (pH 4.5). The NanoBiE gives well-defined, reproducible and sharp stripping peaks. The peak current response increases linearly with the metal concentration in a range of 5.0–60.0 μg L −1 , with a detection limit of 0.8 and 0.4 μg L −1 for Pb 2+ and Cd 2+ , respectively. The morphology and composition of the modified electrode before and after voltammetric measurements were analysed by scanning electron microscopy and energy dispersive X-ray analysis. The NanoBiE was successfully applied to analysis of Pb 2+ and Cd 2+ in real water samples and the method was validated by ICP-MS technique, suggesting that the electrode can be considered as an interesting alternative to the bismuth film electrode for possible use in electrochemical studies and electro analysis. (author)

  17. Bi-induced band gap reduction in epitaxial InSbBi alloys

    Energy Technology Data Exchange (ETDEWEB)

    Rajpalke, M. K.; Linhart, W. M.; Birkett, M.; Alaria, J.; Veal, T. D., E-mail: T.Veal@liverpool.ac.uk [Stephenson Institute for Renewable Energy and Department of Physics, School of Physical Sciences, University of Liverpool, Liverpool L69 7ZF (United Kingdom); Yu, K. M. [Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Bomphrey, J. J.; Jones, T. S.; Ashwin, M. J., E-mail: M.J.Ashwin@warwick.ac.uk [Department of Chemistry, University of Warwick, Coventry CV4 7AL (United Kingdom); Sallis, S.; Piper, L. F. J. [Materials Science and Engineering, Binghamton University, Binghamton, New York 13902 (United States)

    2014-11-24

    The properties of molecular beam epitaxy-grown InSb{sub 1−x}Bi{sub x} alloys are investigated. Rutherford backscattering spectrometry shows that the Bi content increases from 0.6% for growth at 350 °C to 2.4% at 200 °C. X-ray diffraction indicates Bi-induced lattice dilation and suggests a zinc-blende InBi lattice parameter of 6.626 Å. Scanning electron microscopy reveals surface InSbBi nanostructures on the InSbBi films for the lowest growth temperatures, Bi droplets at intermediate temperatures, and smooth surfaces for the highest temperature. The room temperature optical absorption edge was found to change from 172 meV (7.2 μm) for InSb to ∼88 meV (14.1 μm) for InSb{sub 0.976}Bi{sub 0.024}, a reduction of ∼35 meV/%Bi.

  18. Luminescence and electron degradation properties of Bi doped CaO phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Yousif, A. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, ZA 9300 (South Africa); Department of Physics, Faculty of Education, University of Khartoum, P.O. Box 321, 11115 Omdurman (Sudan); Kroon, R.E.; Coetsee, E.; Ntwaeaborwa, O.M. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, ZA 9300 (South Africa); Seed Ahmed, H.A.A. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, ZA 9300 (South Africa); Department of Physics, Faculty of Education, University of Khartoum, P.O. Box 321, 11115 Omdurman (Sudan); Swart, H.C., E-mail: swarthc@ufs.ac.za [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, ZA 9300 (South Africa)

    2015-11-30

    Graphical abstract: - Highlights: • Blue emitting Ca{sub 1−x}O:Bi{sub x=0.5%} phosphor powder was successfully prepared. • Strong blue near-UV emission was obtained. • Electron beam induced cathodoluminescence intensity degradation occurred. • XPS was successfully used to explain the degradation process. - Abstract: Ca{sub 1−x}O:Bi{sub x=0.5%} phosphor powder was successfully synthesized by the sol-gel combustion method. The structure, morphology and luminescent properties of the phosphor were characterized by X-ray diffraction, scanning electron microscopy, photoluminescence and cathodoluminescence (CL) spectroscopy. The results showed that the Ca{sub 1−x}O:Bi{sub x=0.5%} consisted of single face-centred cubic crystals and that the phosphor particles were uniformly distributed. When the phosphor was excited by a xenon lamp at 355 nm, or a 325 nm He–Cd laser, or electron beam, it emitted strongly in the blue near-UV range with a wavelength of 395 nm ({sup 3}P{sub 1} → {sup 1}S{sub 0} transition of Bi{sup 3+}). The CL intensity was monitored as a function of the accelerating voltage and also as a function of the beam current. The powder was also subjected to a prolonged electron beam irradiation to study the electron beam induced CL intensity degradation. X-ray photoelectron spectroscopy was used to analyze the Ca{sub 1−x}O:Bi{sub x=0.5%} phosphor sample surface before and after degradation.

  19. Crystal scintillators for use in check-light source for thermoluminescent systems

    Science.gov (United States)

    Nagpal, J. S.; Sabharwal, S. C.; Chougaonkar, M. P.; Godbole, S. V.

    1999-08-01

    Beta ( 63Ni, Emax 0.063 MeV) excited radioluminescence of indigenously grown crystal scintillators CsI(Tl), Bi 4Ge 3O 12 and CdWO 4 has been studied for its use in check-light source needed for thermoluminescence systems. Temperature coefficient of the light output over 298-323 K and the beta-induced TL of the scintillators over 298-553 K are reported.

  20. Collected radiochemical procedures (radiochemistry group CNC-11)

    International Nuclear Information System (INIS)

    Smith, H.L.

    1975-04-01

    Separation techniques are given for: Am, Sb, As, Ba, Be, Bi, C, Cd, Ca, Ce, Cs, Cl, Cr, Co, Cm, Ge, Au, In, Fe, lanthanides, Pb, Mg, Mn, Mo, Np, Ni, Nb, Pd, P, Pu, Pa, Rh, Ru, Sc, Ag, Na, Sr, sulfate, Ta, Te, Tl, Th, Sn, transactinides, tritium, W, U, Y, and Zr. Combined procedures and group separations of the heavy elements are also included

  1. Improving CS regulations.

    Energy Technology Data Exchange (ETDEWEB)

    Nesse, R.J.; Scheer, R.M.; Marasco, A.L.; Furey, R.

    1980-10-01

    President Carter issued Executive Order 12044 (3/28/78) that required all Federal agencies to distinguish between significant and insignificant regulations, and to determine whether a regulation will result in major impacts. This study gathered information on the impact of the order and the guidelines on the Office of Conservation and Solar Energy (CS) regulatory practices, investigated problems encountered by the CS staff when implementing the order and guidelines, and recommended solutions to resolve these problems. Major tasks accomplished and discussed are: (1) legislation, Executive Orders, and DOE Memoranda concerning Federal administrative procedures relevant to the development and analysis of regulations within CS reviewed; (2) relevant DOE Orders and Memoranda analyzed and key DOE and CS staff interviewed in order to accurately describe the current CS regulatory process; (3) DOE staff from the Office of the General Counsel, the Office of Policy and Evaluation, the Office of the Environment, and the Office of the Secretary interviewed to explore issues and problems encountered with current CS regulatory practices; (4) the regulatory processes at five other Federal agencies reviewed in order to see how other agencies have approached the regulatory process, dealt with specific regulatory problems, and responded to the Executive Order; and (5) based on the results of the preceding four tasks, recommendations for potential solutions to the CS regulatory problems developed. (MCW)

  2. Dispersion interactions between neighboring Bi atoms in (BiH3 )2 and Te(BiR2 )2.

    Science.gov (United States)

    Haack, Rebekka; Schulz, Stephan; Jansen, Georg

    2018-03-13

    Triggered by the observation of a short Bi⋯Bi distance and a BiTeBi bond angle of only 86.6° in the crystal structure of bis(diethylbismuthanyl)tellurane quantum chemical computations on interactions between neighboring Bi atoms in Te(BiR 2 ) 2 molecules (R = H, Me, Et) and in (BiH 3 ) 2 were undertaken. Bi⋯Bi distances atoms were found to significantly shorten upon inclusion of the d shells of the heavy metal atoms into the electron correlation treatment, and it was confirmed that interaction energies from spin component-scaled second-order Møller-Plesset theory (SCS-MP2) agree well with coupled-cluster singles and doubles theory including perturbative triples (CCSD(T)). Density functional theory-based symmetry-adapted perturbation theory (DFT-SAPT) was used to study the anisotropy of the interplay of dispersion attraction and steric repulsion between the Bi atoms. Finally, geometries and relative stabilities of syn-syn and syn-anti conformers of Te(BiR 2 ) 2 (R = H, Me, Et) and interconversion barriers between them were computed. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  3. CdS films deposited by chemical bath under rotation

    International Nuclear Information System (INIS)

    Oliva-Aviles, A.I.; Patino, R.; Oliva, A.I.

    2010-01-01

    Cadmium sulfide (CdS) films were deposited on rotating substrates by the chemical bath technique. The effects of the rotation speed on the morphological, optical, and structural properties of the films were discussed. A rotating substrate-holder was fabricated such that substrates can be taken out from the bath during the deposition. CdS films were deposited at different deposition times (10, 20, 30, 40 and 50 min) onto Corning glass substrates at different rotation velocities (150, 300, 450, and 600 rpm) during chemical deposition. The chemical bath was composed by CdCl 2 , KOH, NH 4 NO 3 and CS(NH 2 ) 2 as chemical reagents and heated at 75 deg. C. The results show no critical effects on the band gap energy and the surface roughness of the CdS films when the rotation speed changes. However, a linear increase on the deposition rate with the rotation energy was observed, meanwhile the stoichiometry was strongly affected by the rotation speed, resulting a better 1:1 Cd/S ratio as speed increases. Rotation effects may be of interest in industrial production of CdTe/CdS solar cells.

  4. CdS films deposited by chemical bath under rotation

    Energy Technology Data Exchange (ETDEWEB)

    Oliva-Aviles, A.I., E-mail: aoliva@mda.cinvestav.mx [Centro de Investigacion y de Estudios Avanzados Unidad Merida, Departamento de Fisica Aplicada. A.P. 73-Cordemex, 97310 Merida, Yucatan (Mexico); Patino, R.; Oliva, A.I. [Centro de Investigacion y de Estudios Avanzados Unidad Merida, Departamento de Fisica Aplicada. A.P. 73-Cordemex, 97310 Merida, Yucatan (Mexico)

    2010-08-01

    Cadmium sulfide (CdS) films were deposited on rotating substrates by the chemical bath technique. The effects of the rotation speed on the morphological, optical, and structural properties of the films were discussed. A rotating substrate-holder was fabricated such that substrates can be taken out from the bath during the deposition. CdS films were deposited at different deposition times (10, 20, 30, 40 and 50 min) onto Corning glass substrates at different rotation velocities (150, 300, 450, and 600 rpm) during chemical deposition. The chemical bath was composed by CdCl{sub 2}, KOH, NH{sub 4}NO{sub 3} and CS(NH{sub 2}){sub 2} as chemical reagents and heated at 75 deg. C. The results show no critical effects on the band gap energy and the surface roughness of the CdS films when the rotation speed changes. However, a linear increase on the deposition rate with the rotation energy was observed, meanwhile the stoichiometry was strongly affected by the rotation speed, resulting a better 1:1 Cd/S ratio as speed increases. Rotation effects may be of interest in industrial production of CdTe/CdS solar cells.

  5. Study of the advantage and drawback of using Cs+ primary ion beam on metal targets

    International Nuclear Information System (INIS)

    Vallerand, P.; Baril, M.

    1977-01-01

    The simplicity of the design of the thermoionic primary ion-source renders its use very easy. Four groups of targets were studied: 1) pure metals (Cu, Cd, Al, Mo, Pb, Zn); 2) various phosphor bronzes of certified composition; 3) four different iron and nickel stainless steels; 4) two kinds of Babbitt alloys. The intensity of the positive spectra is much lower than that of the negative ones. But both contain useful complementary information. Combining the use of a leak of oxygen with the bombardment by Cs + ion enables the detection of many elements at a much lower level of concentration. The easiness of cluster production is another characteristic of Cs + bombardment. (Auth.)

  6. Radiation damage in undoped CsI and CsI(Tl)

    International Nuclear Information System (INIS)

    Woody, C.L.; Kierstead, J.A.; Levy, P.W.; Stoll, S.

    1992-01-01

    Radiation damage has been studied in undoped CsI and CsI(TI) crystals using 60 Co gamma radiation for doses up to ∼ 4.2 x 10 6 . Samples from various manufacturers were measured ranging in size from 2.54 cm long cylinders to a 30 cm long block. Measurements were made on the change in optical transmission and scintillation light output as a function of dose. Although some samples showed a small change in transmission, a significant change in light output was observed for all samples. Recovery from damage was also studied as a function of time and exposure to UV light. A short lived phosphorescence was observed in undoped CsI, similar to the phosphorescence seen in CsI(TI)

  7. Regeneration of Used Frying Palm Oil with Coffee Silverskin (CS), CS Ash (CSA) and Nanoparticles of CS (NCS).

    Science.gov (United States)

    Ismail, Samir Abd-Elmonem A; El-Anany, Ayman Mohammed; Ali, Rehab Farouk M

    2017-01-01

    The present investigation aimed to evaluate the efficiency of coffee silverskin (CS), CS ash (CSA) and nanoparticles of CS (NCS) in regeneration the quality of used frying palm oil. The adsorbents were mixed individually with used frying palm oil at level 4% (w/v) for 60 min. The properties of CS, CSA and NCS adsorbents were studied using (SEM) scanning electron microscopy technique. Some of physico-chemical characteristics of used frying palm oil (UFPO) and UFPO treated with adsorbents were determined. The results showed that the CS ash particles composed of irregular spherical and semispherical grains with deep cavities. The size of particles of CS ash ranged in diameter from 1.1 to 1.7 µm. The morphology of NCS consisted of cluster-type spherical nanoparticles and flakes. The particle size of NCS varies from 0.9 to 1.7 µm. Purification treatments caused marked (poil compared to untreated oil. The treatment of UFPO with 4% of adsorbents caused significant reductions in the content of free fatty acids ranged from 51.2 to 65.0%. The lowest level of peroxide (2.1 meq/kg) was recorded for UFPO treated with 4% of NCS. The highest reductions (72.8; 70.0%) in p-anisidine value were observed in UFPO treated with 4% of CSA and NCS, respectively. Treatment of UFPO with 4% of CS, CSA and NCS significantly lowered the polar content from 13.9% to 6.3, 4.8 and 3.9%, respectively. The results also indicate that CSA and NCS have nearly the same adsorption efficiency in lowering polymer content of UFPO. Filtration treatment of UFPO with 4% of CS, CSA and NCS markedly lowered the viscosity and colour values of treated UFPO.

  8. Properties of CsI and CsI-TMAE photocathodes

    International Nuclear Information System (INIS)

    Anderson, D.F.; Kwan, S.; Peskov, V.; Hoeneisen, B.

    1992-06-01

    The importance of heating the CsI or CsI-TMAE photocathodes during preparation, as well as the importance of the gas environment on the quantum efficiency is presented. The dependence of the aging characteristics of these photocathodes on the operating temperature, on the presence of gas, and on the charge amplification of the chamber is also discussed. For CsI photocathodes charges in excess of 2x10 14 e - /mm 2 can be collected with little degradation of performance. A timing resolution of 0.55 ns is also achieved for single photoelectrons suggesting a possible time-of-flight detector

  9. Identification of novel indicators of cyclosporine A nephrotoxicity in a CD-1 mouse model

    International Nuclear Information System (INIS)

    O'Connell, Sein; Slattery, Craig; Ryan, Michael P.; McMorrow, Tara

    2011-01-01

    The calcineurin inhibitor cyclosporine A (CsA) is a widely used immunosuppressive agent. However, nephrotoxicity is a serious side effect observed in patients which limits clinical use of CsA. CsA nephrotoxicity is associated with tubulointerstitial injury progressing to nephropathy. This is typically diagnosed by invasive renal biopsy and is often only detected when the disease process is well advanced. Therefore identification of novel, early indicators of CsA nephrotoxicity could be clinically advantageous. This study aimed to establish a murine model of CsA nephrotoxicity and to identify urinary proteins that may indicate the onset of CsA-induced nephropathy using 2-D gel electrophoresis. CsA nephrotoxicity was induced in CD-1 mice by daily CsA administration for 4 weeks. By week 4, elevated serum creatinine and proteinuria were observed after CsA treatment indicating significant renal dysfunction. Decreased cadherin-1, increased α-smooth muscle actin and fibroblast specific protein 1 in kidney tissue indicated disruption of normal tubular architecture. Alterations in podocin and uromodulin were also observed which may indicate damage to other segments of the nephron. Proteomic analysis of urine identified a number of differentially regulated proteins that may be involved in early CsA nephropathy including cadherin 1, superoxide dismutase and vinculin. These findings suggest novel mechanisms of CsA nephrotoxicity and identify novel potential markers of the disease.

  10. Facile synthesis of Bi/BiOCl composite with selective photocatalytic properties

    International Nuclear Information System (INIS)

    Chen, Dongling; Zhang, Min; Lu, Qiuju; Chen, Junfang; Liu, Bitao; Wang, Zhaofeng

    2015-01-01

    This paper presents a novel and facile method to fabricate Bi/BiOCl composites with dominant (001) facets in situ via a microwave reduction route. Different characterization techniques, including X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission scanning electron microscopy (TEM), UV–vis diffuse reflectance spectrometry (DRS), X-ray photoelectron spectroscopy (XPS), electron spin resonance spectroscopy (ESR), cathodoluminescence spectrum (CL), and lifetime, have been employed to investigate the structure, optical and electrical properties of the Bi/BiOCl composites. The experimental results show that the introduction of Bi particles can efficiently enhance the photocatalytic performance of BiOCl for the degradation of several dyes under ultraviolet (UV) light irradiation, especially for negative charged methyl orange (MO). Unlike the UV photocatalytic performance, such Bi/BiOCl composite shows higher degradation efficiency towards rhodamine B (RhB) than MO and methylene blue (MB) under visible light irradiation. This special photocatalytic performance can be ascribed to the synergistic effect between oxygen vacancies and Bi particles. This work provides new insights about the photodegradation mechanisms of MO, MB and RhB under UV and visible light irradiation, which would be helpful to guide the selection of an appropriate catalyst for other pollutants. - Highlights: • Bi/BiOCl composites were synthesized via a microwave reduction. • Tunable selectivity photocatalytic activity can be achieved. • Photodegradation mechanism under UV and visible light were proposed

  11. Bi-directional activation between mesenchymal stem cells and CLL B-cells: implication for CLL disease progression.

    Science.gov (United States)

    Ding, Wei; Nowakowski, Grzegorz S; Knox, Traci R; Boysen, Justin C; Maas, Mary L; Schwager, Susan M; Wu, Wenting; Wellik, Linda E; Dietz, Allan B; Ghosh, Asish K; Secreto, Charla R; Medina, Kay L; Shanafelt, Tait D; Zent, Clive S; Call, Timothy G; Kay, Neil E

    2009-11-01

    It was hypothesized that contact between chronic lymphocytic leukaemia (CLL) B-cells and marrow stromal cells impact both cell types. To test this hypothesis, we utilized a long-term primary culture system from bone biopsies that reliably generates a mesenchymal stem cell (MSC). Co-culture of MSC with CLL B-cells protected the latter from both spontaneous apoptosis and drug-induced apoptosis. The CD38 expression in previously CD38 positive CLL B-cells was up-regulated with MSC co-culture. Upregulation of CD71, CD25, CD69 and CD70 in CLL B-cells was found in the co-culture. CD71 upregulation was more significantly associated with high-risk CLL, implicating CD71 regulation in the microenvironment predicting disease progression. In MSC, rapid ERK and AKT phosphorylation (within 30 min) were detected when CLL B-cells and MSC were separated by transwell; indicating that activation of MSC was mediated by soluble factors. These findings support a bi-directional activation between bone marrow stromal cells and CLL B-cells.

  12. Colloidal CsPbBr3 Perovskite Nanocrystals: Luminescence beyond Traditional Quantum Dots.

    Science.gov (United States)

    Swarnkar, Abhishek; Chulliyil, Ramya; Ravi, Vikash Kumar; Irfanullah, Mir; Chowdhury, Arindam; Nag, Angshuman

    2015-12-14

    Traditional CdSe-based colloidal quantum dots (cQDs) have interesting photoluminescence (PL) properties. Herein we highlight the advantages in both ensemble and single-nanocrystal PL of colloidal CsPbBr3 nanocrystals (NCs) over the traditional cQDs. An ensemble of colloidal CsPbBr3 NCs (11 nm) exhibits ca. 90 % PL quantum yield with narrow (FWHM=86 meV) spectral width. Interestingly, the spectral width of a single-NC and an ensemble are almost identical, ruling out the problem of size-distribution in PL broadening. Eliminating this problem leads to a negligible influence of self-absorption and Förster resonance energy transfer, along with batch-to-batch reproducibility of NCs exhibiting PL peaks within ±1 nm. Also, PL peak positions do not alter with measurement temperature in the range of 25 to 100 °C. Importantly, CsPbBr3 NCs exhibit suppressed PL blinking with ca. 90 % of the individual NCs remain mostly emissive (on-time >85 %), without much influence of excitation power. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Concentration of 134Cs and 137Cs in Malaysian palm products

    International Nuclear Information System (INIS)

    Yii Mei Wo; Nor Aza Hassan; Narizan Sanusi

    2008-08-01

    Until today, countries importing food products from Malaysia, in region such as Indian Continental, Middle East, Central Europe and Central America still require the products to be tested for the radioactive contamination particularly for 134 Cs and 137 Cs. Information extracted from 3371 analytical results observed on isotopic concentration for 134 Cs and 137 Cs in the exported Malaysia origins palm products between years 2002 until 2007 had been summarized and reported in this work. Data shown that the concentration level of the concerned radio nuclides are below the minimum detectable activity and also well below maximum permissible limits adopted by Malaysian Government and also the international bodies. (Author)

  14. Bismuth-boron multiple bonding in BiB_2O"- and Bi_2B"-

    International Nuclear Information System (INIS)

    Jian, Tian; Cheung, Ling Fung; Chen, Teng-Teng; Wang, Lai-Sheng

    2017-01-01

    Despite its electron deficiency, boron is versatile in forming multiple bonds. Transition-metal-boron double bonding is known, but boron-metal triple bonds have been elusive. Two bismuth boron cluster anions, BiB_2O"- and Bi_2B"-, containing triple and double B-Bi bonds are presented. The BiB_2O"- and Bi_2B"- clusters are produced by laser vaporization of a mixed B/Bi target and characterized by photoelectron spectroscopy and ab initio calculations. Well-resolved photoelectron spectra are obtained and interpreted with the help of ab initio calculations, which show that both species are linear. Chemical bonding analyses reveal that Bi forms triple and double bonds with boron in BiB_2O"- ([Bi≡B-B≡O]"-) and Bi_2B"- ([Bi=B=Bi]"-), respectively. The Bi-B double and triple bond strengths are calculated to be 3.21 and 4.70 eV, respectively. This is the first experimental observation of Bi-B double and triple bonds, opening the door to design main-group metal-boron complexes with multiple bonding. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. The modulation and reconstruction of a BiO layer of cuprate Bi2212

    International Nuclear Information System (INIS)

    Fan Wei; Zeng, Z

    2011-01-01

    Studies based on ab initio density functional theory show that the modulated structures of BiO surfaces of cuprate Bi2212 superconductors are spontaneously formed and closely related to the reconstructions of BiO surfaces. The reconstructions of BiO layers occur both on the surface and in the bulk, accompanied with the formations of BiO-zigzag chains and Bi 2 O 2 quadrilaterals. The structural modulations of the BiO surface are along the b axis, perpendicular to the BiO-zigzag chains along the a axis. Our calculations provide a unified understanding of the formation of modulating structures in Bi2212. Another interesting result is that electronic structures of BiO surfaces are significantly influenced by the CuO 2 layer beneath because of the structural modulations and reconstructions.

  16. Novel Bi/BiOBr/AgBr composite microspheres: Ion exchange synthesis and photocatalytic performance

    Science.gov (United States)

    Lyu, Jianchang; Li, Zhenlu; Ge, Ming

    2018-06-01

    Novel Bi/BiOBr/AgBr composite microspheres were prepared by a rational in situ ion exchange reaction between Bi/BiOBr microspheres and AgNO3. The characteristic of the as-obtained ternary microspheres was tested by X-ray diffraction (XRD), energy dispersive X-ray spectrometer (EDS), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and photoluminescence (PL). Under visible light irradiation, Bi/BiOBr/AgBr microspheres exhibited an excellent photocatalytic efficiency for rhodamine B (RhB) degradation, which was about 1.4 and 4.9 times as high as that of Bi/BiOBr and BiOBr/AgBr, demonstrating that the highest separation efficiency of charge carriers in the heterostructured Bi/BiOBr/AgBr. The photocatalytic activity of Bi/BiOBr/AgBr microspheres just exhibited a slight decrease after three consecutive cycles. The photocatalytic mechanism investigation confirmed that the superoxide radicals (O2•-) were the dominant reactive oxygen species for RhB degradation in Bi/BiOBr/AgBr suspension.

  17. Photocatalytic activity of Bi_2WO_6/Bi_2S_3 heterojunctions: the facilitation of exposed facets of Bi_2WO_6 substrate

    International Nuclear Information System (INIS)

    Yan, Long; Wang, Yufei; Shen, Huidong; Zhang, Yu; Li, Jian; Wang, Danjun

    2017-01-01

    Highlights: • Bi_2S_3/Bi_2WO_6 hybrids with exposed (020) Bi_2WO_6 facets have been synthesized. • X-ray photoelectron spectroscopy reveals that a small amount of Bi_2S_3 was formed. • The enhanced photoactivity of hybrids is due to heterojunction and (020) facets. • A possible photocatalytic degradation mechanism is proposed. - Abstract: Bi_2S_3/Bi_2WO_6 hybrid architectures with exposed (020) Bi_2WO_6 facets have been synthesized via a controlled anion exchange approach. X-ray photoelectron spectroscopy (XPS) reveals that a small amount of Bi_2S_3 was formed on the surface of Bi_2WO_6 during the anion exchange process, thus leading to the transformation from the Bi_2WO_6 to Bi_2S_3/Bi_2WO_6. A rhodamine B (RhB) aqueous solution was chosen as model organic pollutants to evaluate the photocatalytic activities of the Bi_2S_3/Bi_2WO_6 catalysts. Under visible light irradiation, the Bi_2S_3/Bi_2WO_6-TAA displayed the excellent visible light photoactivities compared with pure Bi_2S_3, Bi_2WO_6 and other composite photocatalysts. The efficient photocatalytic activity of the Bi_2S_3/Bi_2WO_6-TAA composite microspheres was ascribed to the constructed heterojunctions and the inner electric field caused by the exposed (020) Bi_2WO_6 facets. Active species trapping experiments revealed that h"+ and O_2·"− are the main active species in the photocatalytic process. Furthermore, the as-obtained photocatalysts showed good photocatalytic activity after four recycles. The results presented in this study provide a new concept for the rational design and development of highly efficient photocatalysts.

  18. Separation of 134Cs and 137Cs from 125I solution for medical applications

    International Nuclear Information System (INIS)

    Ram, Ramu; Dash, Ashutosh; Banerjee, Dayamoy

    2015-01-01

    While neutron irradiation of natural Xe gas followed by wet chemical dissolution of activation products constitutes a successful paradigm for the small scale production 125 I, the concomitant production of 134 Cs and 137 Cs emerged as the primary impediment which necessitates purification of 125 I solution. This paper describes an ion-exchange chromatographic technique using Resorcinol Formaldehyde (RF) resin to purify 125 I solution from 134 Cs and 137 Cs impurities. A thorough investigation of the adsorption parameters of RF resin was carried out to arrive at the experimental conditions resulting optimum retention of 134 Cs and 137 Cs impurities. Based on the experimental findings, an optimized separation procedure was developed in which the neutron irradiated dissolved products at pH ∝ 13 was passed through a chromatography column containing RF resin where in 134 Cs and 137 Cs impurities gets adsorbed leaving behind 125 I to appear in the effluent. The overall recovery of 125 I was >90% with acceptable purity amenable for clinical applications.

  19. Heterojunction BiOI/Bi2MoO6 nanocomposite with much enhanced photocatalytic activity

    International Nuclear Information System (INIS)

    Li, Wen Ting; Zheng, Yi Fan; Yin, Hao Yong; Song, Xu Chun

    2015-01-01

    BiOI/Bi 2 MoO 6 heterostructures with different amounts of BiOI were successfully prepared via a facile deposition method. The obtained BiOI/Bi 2 MoO 6 photocatalysts exhibited much higher visible light (λ > 420 nm) induced photocatalytic activity compared with single Bi 2 MoO 6 and BiOI photocatalysts. 20 % BiOI/Bi 2 MoO 6 nanocomposite exhibited the highest photocatalytic activity with almost all RhB decomposed within 70 min. However, excess BiOI covering on the surface of Bi 2 MoO 6 can inversely reduce the photocatalytic activity. The enhanced photocatalytic activities could be resulted from the function of the novel p–n heterojunction interface between Bi 2 MoO 6 and BiOI, which could separate photoinduced carriers efficiently. Possible mechanisms on the basis of the relative band positions were also discussed

  20. Multiferroic BiFeO3-BiMnO3 Nanocheckerboard From First Principles

    OpenAIRE

    Palova, L.; Chandra, P.; Rabe, K. M.

    2010-01-01

    We present a first principles study of an unusual heterostructure, an atomic-scale checkerboard of BiFeO3-BiMnO3, and compare its properties to the two bulk constituent materials, BiFeO3 and BiMnO3. The "nanocheckerboard" is found to have a multiferroic ground state with the desired properties of each constituent: polar and ferrimagnetic due to BiFeO3 and BiMnO3, respectively. The effect of B-site cation ordering on magnetic ordering in the BiFeO3-BiMnO3 system is studied. The checkerboard ge...

  1. [Energy pooling collisions for K(4P) + Cs(5D) in a K-Cs mixture].

    Science.gov (United States)

    Aihemaiti, Pulati; Dai, Kang; Lu, Xin-hong; Shen, Yi-fan

    2005-04-01

    The rate coefficients for energy-pooling collisions K(4P) + Cs(5D) --> Cs(6S) + K(4D, 6S) in the K-Cs vapor mixture were measured relative to a known energy-pooling rate coefficient of a homonuclear reaction [i. e., Cs(6P) + Cs(5D) --> Cs(6S) + Cs (7D(J))]. Populations of the Cs(6P, 5D) and K(4P) states were produced by photodissociation of K2 and Cs2 molecules through the use of a dye laser radiation. The resulting fluorescence included the direct components emitted in the decay of the excited states produced by photodissociation and the induced components arising from the collisionally populated states. By combining relative intensities of the components with the effective lifetimes of Cs(6P) and K(4P) states, the rate coefficients (in units of 10(-9) cm3 x s(-1)) for the heteronuclear energy-pooling were found to be 2.6 and 3.6, respectively. The contribution to the rate coefficients from other processes are discussed.

  2. Gradient Self-Doped CuBi2O4 with Highly Improved Charge Separation Efficiency.

    Science.gov (United States)

    Wang, Fuxian; Septina, Wilman; Chemseddine, Abdelkrim; Abdi, Fatwa F; Friedrich, Dennis; Bogdanoff, Peter; van de Krol, Roel; Tilley, S David; Berglund, Sean P

    2017-10-25

    A new strategy of using forward gradient self-doping to improve the charge separation efficiency in metal oxide photoelectrodes is proposed. Gradient self-doped CuBi 2 O 4 photocathodes are prepared with forward and reverse gradients in copper vacancies using a two-step, diffusion-assisted spray pyrolysis process. Decreasing the Cu/Bi ratio of the CuBi 2 O 4 photocathodes introduces Cu vacancies that increase the carrier (hole) concentration and lowers the Fermi level, as evidenced by a shift in the flat band toward more positive potentials. Thus, a gradient in Cu vacancies leads to an internal electric field within CuBi 2 O 4 , which can facilitate charge separation. Compared to homogeneous CuBi 2 O 4 photocathodes, CuBi 2 O 4 photocathodes with a forward gradient show highly improved charge separation efficiency and enhanced photoelectrochemical performance for reduction reactions, while CuBi 2 O 4 photocathodes with a reverse gradient show significantly reduced charge separation efficiency and photoelectrochemical performance. The CuBi 2 O 4 photocathodes with a forward gradient produce record AM 1.5 photocurrent densities for CuBi 2 O 4 up to -2.5 mA/cm 2 at 0.6 V vs RHE with H 2 O 2 as an electron scavenger, and they show a charge separation efficiency of 34% for 550 nm light. The gradient self-doping accomplishes this without the introduction of external dopants, and therefore the tetragonal crystal structure and carrier mobility of CuBi 2 O 4 are maintained. Lastly, forward gradient self-doped CuBi 2 O 4 photocathodes are protected with a CdS/TiO 2 heterojunction and coated with Pt as an electrocatalyst. These photocathodes demonstrate photocurrent densities on the order of -1.0 mA/cm 2 at 0.0 V vs RHE and evolve hydrogen with a faradaic efficiency of ∼91%.

  3. Changing US Attributes After CS-US Pairings Changes CS-Attribute-Assessments: Evidence for CS-US Associations in Attribute Conditioning.

    Science.gov (United States)

    Förderer, Sabine; Unkelbach, Christian

    2016-03-01

    Attribute Conditioning (AC) refers to people's changed assessments of stimuli's (CSs) attributes due to repeated pairing with stimuli (USs) possessing these attributes; for example, when an athletic person (US) is paired with a neutral person (CS), the neutral person is judged to be more athletic after the pairing. We hypothesize that this AC effect is due to CSs' associations with USs rather than direct associations with attributes. Three experiments test this hypothesis by changing US attributes after CS-US pairings. Experiments 1 and 2 conditioned athleticism by pairing neutral men (CSs) with athletic and non-athletic USs. Post-conditioning, USs' athleticism was reversed, which systematically influenced participants' assessment of CS athleticism. Experiment 3 conditioned athleticism and changed USs' musicality after CS-US pairings. This post-conditioning change affected musicality assessments of CSs but did not influence athleticism-assessments. The results indicate that AC effects are based on an associative CS-US-attribute structure. © 2016 by the Society for Personality and Social Psychology, Inc.

  4. A novel vanadosilicate with hexadeca-coordinated Cs+ ions as a highly effective Cs+ remover

    International Nuclear Information System (INIS)

    Datta, Shuvo Jit; Moon, Won Kyung; Choi, Do Young; Hwang, In Chul; Yoon, Kyung Byung

    2014-01-01

    The effective removal of 137 Cs + ions from contaminated groundwater and seawater and from radioactive nuclear waste solutions is crucial for public health and for the continuous operation of nuclear power plants. Various 137 Cs + removers have been developed, but more effective 137 Cs + removers are still needed. A novel microporous vanadosilicate with mixed-valence vanadium (V 4+ and V 5+ ) ions is now reported, which shows an excellent ability for Cs + capture and immobilization from groundwater, seawater, and nuclear waste solutions. This material is superior to other known materials in terms of selectivity, capacity, and kinetics, and at very low Cs + concentrations, it was found to be the most effective material for the removal of radioactive Cs + ions under the test conditions. This novel vanadosilicate also contains hexadeca-coordinated Cs + ions, which corresponds to the highest coordination number ever described.

  5. Bi-layer non-doped small-molecular white organic light-emitting diodes with high colour stability

    International Nuclear Information System (INIS)

    Chen Shuming; Kwok, Hoi-Sing; Zhao Zujin; Tang Benzhong; Wang Zhiming; Lu Ping; Gao Zhao; Ma Yuguang

    2011-01-01

    Bi-layer non-doped white organic light-emitting diodes (WOLEDs) with hole-transporting layer 4-(4-(1,2,2-triphenylvinyl)phenyl)-7-(5-(4-(1,2,2-triphenylvinyl)phenyl) thiophen-2yl)benzo[c][1,2,5]thiadiazole (BTPETTD) as a red emitter and electron-transporting layer 4,4'-bis(1-phenyl-1H-phenanthro[9,10-d]imidazol-2-yl)biphenyl (DDPi) as a blue emitter are demonstrated. The blue emission is due to direct recombination of excitons in DPPi, while the red emission originates not only from the direct recombination of excitons in BTPETTD but also from a colour down-conversion process by absorbing blue emission and re-emitting red photons. The combination of blue emission and red emission yields an efficient and extremely stable white colour, regardless of driving voltages. In our demonstration, a bi-layer WOLED with an efficiency of 4.2 cd A -1 at 1000 cd m -2 , 1931 Commision International de L'Eclairage coordinates of (0.31, 0.31) and a high colour rendering index of 92 over a wide range of driving voltages is obtained.

  6. Hybridization of Single Nanocrystals of Cs4PbBr6 and CsPbBr3.

    Science.gov (United States)

    Weerd, Chris de; Lin, Junhao; Gomez, Leyre; Fujiwara, Yasufumi; Suenaga, Kazutomo; Gregorkiewicz, Tom

    2017-09-07

    Nanocrystals of all-inorganic cesium lead halide perovskites (CsPbX 3 , X = Cl, Br, I) feature high absorption and efficient narrow-band emission which renders them promising for future generation of photovoltaic and optoelectronic devices. Colloidal ensembles of these nanocrystals can be conveniently prepared by chemical synthesis. However, in the case of CsPbBr 3 , its synthesis can also yield nanocrystals of Cs 4 PbBr 6 and the properties of the two are easily confused. Here, we investigate in detail the optical characteristics of simultaneously synthesized green-emitting CsPbBr 3 and insulating Cs 4 PbBr 6 nanocrystals. We demonstrate that, in this case, the two materials inevitably hybridize, forming nanoparticles with a spherical shape. The actual amount of these Cs 4 PbBr 6 nanocrystals and nanohybrids increases for synthesis at lower temperatures, i.e., the condition typically used for the development of perovskite CsPbBr 3 nanocrystals with smaller sizes. We use state-of-the-art electron energy loss spectroscopy to characterize nanoparticles at the single object level. This method allows distinguishing between optical characteristics of a pure Cs 4 PbBr 6 and CsPbBr 3 nanocrystal and their nanohybrid. In this way, we resolve some of the recent misconceptions concerning possible visible absorption and emission of Cs 4 PbBr 6 . Our method provides detailed structural characterization, and combined with modeling, we conclusively identify the nanospheres as CsPbBr 3 /Cs 4 PbBr 6 hybrids. We show that the two phases are independent of each other's presence and merge symbiotically. Herein, the optical characteristics of the parent materials are preserved, allowing for an increased absorption in the UV due to Cs 4 PbBr 6 , accompanied by the distinctive efficient green emission resulting from CsPbBr 3 .

  7. Properties of Cs-intercalated single wall carbon nanotubes investigated by 133Cs Nuclear Magnetic resonance

    KAUST Repository

    Schmid, Marc R.

    2012-11-01

    In the present study, we investigated Cs-intercalated single wall carbon nanotubes (SWCNTs) using 133Cs Nuclear Magnetic resonance. We show that there are two types of Cs cations depending on the insertion level. Indeed, at low concentrations, Static spectra analysis shows that the Cs (α)+ species are fully ionized, i.e. α equal ca.1, while at higher concentrations a second paramagnetically shifted line appears, indicating the formation of Cs (β)+ ions with β < α ∼ +1. At low concentrations and low temperatures the Cs (α)+ ions exhibit a weak hyperfine coupling to the SWCNT conduction electrons, whereas, at higher temperatures, a thermally activated slow-motion diffusion process of the Cs (α)+ ions occurs along the interstitial channels present within the carbon nanotube bundles. At high concentrations, the Cs (β)+ ions seem to occupy well defined positions relative to the carbon lattice. As a matter of fact, the Korringa relaxation behavior suggests a strong hyperfine coupling between Cs nuclei and conduction electrons in the carbon nanotubes and a partial charge transfer, which suggest a plausible Cs(6s)-C(2p) hybridization. © 2012 Elsevier Ltd. All rights reserved.

  8. Collected radiochemical procedures (radiochemistry group CNC-11)

    Energy Technology Data Exchange (ETDEWEB)

    Smith, H.L. (ed.)

    1975-04-01

    Separation techniques are given for: Am, Sb, As, Ba, Be, Bi, C, Cd, Ca, Ce, Cs, Cl, Cr, Co, Cm, Ge, Au, In, Fe, lanthanides, Pb, Mg, Mn, Mo, Np, Ni, Nb, Pd, P, Pu, Pa, Rh, Ru, Sc, Ag, Na, Sr, sulfate, Ta, Te, Tl, Th, Sn, transactinides, tritium, W, U, Y, and Zr. Combined procedures and group separations of the heavy elements are also included. (DLC)

  9. The influence of ion implantation on the surface properties of metals and alloys

    International Nuclear Information System (INIS)

    Grant, W.A.; Carter, G.

    1975-10-01

    The report falls into three sections: (1) annealing behaviour of high dose rare gas (Ne, Ar, Kr, Xe) implantations into silicon; (2) measurement of projected and lateral range parameters for low energy heavy ions (Ar, Cu, Kr, Cd, Xe, Cs, Dy, W, Au, Pb, Bi) in silicon by Rutherford backscattering; (3) surface chemistry of ion implanted solids (e.g. corrosion, catalysis, oxidation, synthesis of compounds in ion implanted layers). (U.K.)

  10. Colloidal synthesis and characterization of Bi2S3 nanoparticles for photovoltaic applications

    International Nuclear Information System (INIS)

    Piras, R; Aresti, M; Saba, M; Marongiu, D; Mula, G; Quochi, F; Mura, A; Bongiovanni, G; Cannas, C; Mureddu, M; Ardu, A; Ennas, G; Musinu, A; Calzia, V; Mattoni, A

    2014-01-01

    Bismuth sulfide is a promising n-type semiconductor for solar energy conversion. We have explored the colloidal synthesis of Bi 2 S 3 nanocrystals, with the aim of employing them in the fabrication of solution-processable solar cells and to replace toxic heavy metals chalcogenides like PbS or CdS, that are currently employed in such devices. We compare different methods to obtain Bi 2 S 3 colloidal quantum dots, including the use of environmentally benign reactants, through organometallic synthesis. Different sizes and shapes were obtained according to the synthesis parameters and the growth process has been rationalized by comparing the predicted morphology with systematic physical-chemistry characterization of nanocrystals by X-ray diffraction, FT-IR spectroscopy, Transmission Electron Microscopy (TEM)

  11. Screen-Printed Electrode Modified by Bismuth /Fe3O4 Nanoparticle/Ionic Liquid Composite Using Internal Standard Normalization for Accurate Determination of Cd(II in Soil

    Directory of Open Access Journals (Sweden)

    Hui Wang

    2017-12-01

    Full Text Available The quality and safety of agricultural products are threatened by heavy metal ions in soil, which can be absorbed by the crops, and then accumulated in the human body through the food chain. In this paper, we report a low-cost and easy-to-use screen-printed electrode (SPE for cadmium ion (Cd(II detection based on differential pulse voltammetry (DPV, which decorated with ionic liquid (IL, magnetite nanoparticle (Fe3O4, and deposited a bismuth film (Bi. The characteristics of Bi/Fe3O4/ILSPE were investigated using scanning electron microscopy, cyclic voltammetry, impedance spectroscopy, and linear sweep voltammetry. We found that the sensitivity of SPE was improved dramatically after functionalized with Bi/Fe3O4/IL. Under optimized conditions, the concentrations of Cd(II are linear with current responses in a range from 0.5 to 40 µg/L with the lowest detection limit of 0.05 µg/L (S/N = 3. Additionally, the internal standard normalization (ISN was used to process the response signals of Bi/Fe3O4/ILSPE and established a new linear equation. For detecting three different Cd(II concentrations, the root-mean-square error using ISN (0.25 is lower than linear method (0.36. Finally, the proposed electrode was applied to trace Cd(II in soil samples with the recovery in the range from 91.77 to 107.83%.

  12. One-pot hydrothermal synthesis of mesoporous Zn(x)Cd(1-x)S/reduced graphene oxide hybrid material and its enhanced photocatalytic activity.

    Science.gov (United States)

    Wang, Xinwei; Tian, Hongwei; Cui, Xiaoqiang; Zheng, Weitao; Liu, Yichun

    2014-09-14

    We successfully synthesized mesoporous Zn(x)Cd(1-x)S/reduced graphene oxide (Z(x)CSG) hybrid materials as photocatalysts using a facile one-pot hydrothermal reaction, in which graphene oxide (GO) was easily reduced (RGO), and simultaneously Zn(x)Cd(1-x)S (Z(x)CS) nanoparticles (NPs) with a mesoporous structure were uniformly dispersed on the RGO sheets. By well tuning the band gap from 3.42 to 2.21 eV by changing the molar ratio of Zn/Cd (or Zn content), Z(x)CSG with an optimal zinc content has been found to have a significant absorption in the visible light (VL) region. In addition, under VL irradiation (λ > 420 nm), Z(x)CSG also showed zinc content-dependent photocatalytic efficiencies for the degradation of methylene blue (MB). Our findings are that, among Z(x)CSG, Z(0.4)CSG displayed not only a superior photodegradation efficiency of MB (98%), but also good removal efficiency of total organic carbon (TOC) (67%). Furthermore, Z(0.4)CSG had a high photocatalytic stability, and could be used repeatedly. The enhanced photocatalytic activity for Z(0.4)CSG could be attributed to a synergistic effect between mesoporous Z(x)CS NPs and RGO, including the optimal band gap and the moderate conduction band position for ZxCS (compared to CdS), efficient separation and transfer ability of photogenerated electron/hole pairs in the presence of RGO sheets, and relatively high surface area for both mesoporous Z(x)CS NPs and RGO.

  13. In-situ synthesis of nanofibers with various ratios of BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z} for effective trichloroethylene photocatalytic degradation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yifan [Department of Chemistry, Inha University, 100 Inharo, Incheon 402-751 (Korea, Republic of); Park, Mira [Department of Organic Materials and Fiber Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Kim, Hak Yong [Department of BIN Convergence Technology, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of); Ding, Bin [College of Textiles, Donghua University, Shanghai 201620 (China); Park, Soo-Jin, E-mail: sjpark@inha.ac.kr [Department of Chemistry, Inha University, 100 Inharo, Incheon 402-751 (Korea, Republic of)

    2016-10-30

    Highlights: • BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z}/PAN fibers were synthesized by in-situ method. • Photodegradation behavior of BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z}/PAN fibers was measured under solar light irradiation. • BiOCl{sub 0.3}/BiOBr{sub 0.3}/BiOI{sub 0.4}/PAN fibers exhibited the highest photocatalytic activity. • Photocatalytic mechanism was discussed in detail. - Abstract: In this work, BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z} (x + y + z = 1) composite nanofibers were prepared through electrospinning and the sol-gel methods. Photocatalytic degradation of trichloroethylene (TCE) by BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z}/PAN nanofibers was systematically investigated via gas chromatography (GC). Optimum photocatalytic activity was achieved with BiOCl{sub 0.3}/BiOBr{sub 0.3}/BiOI{sub 0.4} fibers under solar light irradiation. X-ray photoelectron spectroscopy (XPS) peaks due to C−O and C=O were observed at 286.0 and 288.3 eV, respectively, it indicated that the BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z} mixture had been successfully doped on the polyacrylonitrile (PAN) fibers. Furthermore, X-ray diffraction (XRD) results also confirmed that we had synthesized the as-prepared composite nanofibers successfully. Photocatalytic activities of BiOCl{sub 0.3}/BiOBr{sub 0.3}/BiOI{sub 0.4} were up to 3 times higher than the pure BiOCl, BiOBr and BiOI samples, respectively.

  14. CsI Calorimeter for a Compton-Pair Telescope

    Science.gov (United States)

    Grove, Eric J.

    We propose to build and test a hodoscopic CsI(Tl) scintillating-crystal calorimeter for a medium-energy γ-ray Compton and pair telescope. The design and technical approach for this calorimeter relies deeply on heritage from the Fermi LAT CsI Calorimeter, but it dramatically improves the low-energy performance of that design by reading out the scintillation light with silicon photomultipliers (SiPMs), making the technology developed for Fermi applicable in the Compton regime. While such a hodoscopic calorimeter is useful for an entire class of medium-energy γ-ray telescope designs, we propose to build it explicitly to support beam tests and balloon flight of the Proto-ComPair telescope, the development and construction of which was funded in a four-year APRA program beginning in 2015 ("ComPair: Steps to a Medium Energy γ-ray Mission" with PI J. McEnery of GSFC). That award did not include funding for its CsI calorimeter subsystem, and this proposal is intended to cover that gap. ComPair is a MIDEX-class instrument concept to perform a high-sensitivity survey of the γ-ray sky from 0.5 MeV to 500 MeV. ComPair is designed to provide a dramatic increase in sensitivity relative to previous instruments in this energy range (predominantly INTEGRAL/SPI and Compton COMPTEL), with the same transformative sensitivity increase - and corresponding scientific return- that the Fermi Large Area Telescope provided relative to Compton EGRET. To enable transformative science over a broad range of MeV energies and with a wide field of view, ComPair is a combined Compton telescope and pair telescope employing a silicon-strip tracker (for Compton scattering and pair conversion and tracking) and a solid-state CdZnTe calorimeter (for Compton absorption) and CsI calorimeter (for pair calorimetry), surrounded by a plastic scintillator anti-coincidence detector. Under the current proposal, we will complete the detailed design, assembly, and test of the CsI calorimeter for the risk

  15. Electrode quenching control for highly efficient CsPbBr3 perovskite light-emitting diodes via surface plasmon resonance and enhanced hole injection by Au nanoparticles

    Science.gov (United States)

    Meng, Yan; Wu, Xiaoyan; Xiong, Ziyang; Lin, Chunyan; Xiong, Zuhong; Blount, Ethan; Chen, Ping

    2018-04-01

    Compared to organic-inorganic hybrid metal halide perovskites, all-inorganic cesium lead halides (e.g, CsPbBr3) hold greater promise in being emissive materials for light-emitting diodes owing to their superior optoelectronic properties as well as their higher stabilities. However, there is still considerable potential for breakthroughs in the current efficiency of CsPbBr3 perovskite light-emitting diodes (PeLEDs). Electrode quenching is one of the main problems limiting the current efficiency of PeLEDs when poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) is used as the hole injection layer. In this work, electrode quenching control was realized via incorporating Au NPs into PEDOT:PSS. As a result, the CsPbBr3 PeLEDs realized an improvement in maximum luminescence ranging from ˜2348 to ˜7660 cd m-2 (˜226% enhancement) and current efficiency from 1.65 to 3.08 cd A-1 (˜86% enhancement). Such substantial enhancement of the electroluminescent performance can be attributed to effective electrode quenching control at the PEDOT:PSS/CsPbBr3 perovskite interface via the combined effects of local surface plasma resonance coupling and enhanced hole transportation in the PEDOT:PSS layer by Au nanoparticles.

  16. Facile Fabrication of BiOI/BiOCl Immobilized Films With Improved Visible Light Photocatalytic Performance

    Directory of Open Access Journals (Sweden)

    Yingxian Zhong

    2018-03-01

    Full Text Available HIGHLIGHTSA facial method was used to fabricate BiOI/BiOCl film at room temperature.30% BiOI/BiOCl showed an excellent photocatalytic activity and stability.Improvement of photocatalytic activity was owed to expanded visible light absorption and high separation efficiency of charge.Photocatalysis has been considered to be one of the most promising ways to photodegrade organic pollutants. Herein, a series of BiOI/BiOCl films coating on FTO were fabricated through a simple method at room temperature. The photocatalytic efficiency of 30%BiOI/BiOCl could reach more than 99% aiming to degrading RhB and MB after 90 and 120 min, respectively. Compared with BiOCl, 30%BiOI/BiOCl showed 12 times higher efficiency when degrading RhB. In comparison with BiOI, 30%BiOI/BiOCl showed 5 and 6 times higher efficiency when degrading RhB and MB, respectively. These obvious enhancements were attributed to expanded visible light absorption and high separation performance of photoinduced charge. Moreover, the photocatalytic activity of 30%BiOI/BiOCl had no obvious decrease after five recycles, suggesting that it was a promising photocatalyst for the removal of MB and RhB pollutants. Finally, the possible growth process for the BiOI/BiOCl thin films and photocatalysis mechanism were investigated in details. This work would provide insight to the reasonable construction of BiOX heterojunction and the photocatalytic mechanism in degrading organic pollutants.

  17. Influence of photoinduced Bi-related self-doping on the photocatalytic activity of BiOBr nanosheets

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Dan [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China); Yue, Songtao; Wang, Wei [College of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); An, Tiacheng, E-mail: antc99@gig.ac.cn [Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Li, Guiying [Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Ye, Liqun [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China); College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061 (China); Yip, Ho Yin [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China); Wong, Po Keung, E-mail: pkwong@cuhk.edu.hk [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China)

    2017-01-01

    Highlights: • Bi{sup 5+} self-doped BiOBr nanosheets are achieved under UV irradiation. • Bi{sup 5+} is formed due to the oxidation of surface Bi{sup 3+} by photoexcited h{sup +} of BiOBr. • Two photoinduced h{sup +} mediated oxidation processes happen simultaneously. • Self-doped BiOBr is superior in phenol degradation and bacterial inactivation. • Bi{sup 5+} electron trapping induced photocatalytic enhancement mechanism is proposed. - Abstract: Under UV irradiation, self-doped Bi{sup 5+} is evidenced to be generated on the surface of BiOBr nanosheets, but with well-preserved crystal structure and morphology compared with pure counterpart. Bi{sup 5+} self-doping BiOBr (BiOBr-4) exhibits distinct photocatalytic mode for dyes degradation, as compared with pure BiOBr nanosheets. These photodegradation distinctions are mainly due to the simultaneous occurrence of two photoinduced hole (h{sup +}) mediated oxidation processes on the BiOBr surfaces: (1) a portion of photoexcited h{sup +} participates in the photocatalytic oxidation of dyes, and (2) partial h{sup +} involves the oxidation of Bi{sup 3+} to Bi{sup 5+}. Notably, BiOBr-4 nanosheets comparatively show superior photocatalytic activity for the phenol decomposition as well as the bacterial inactivation. Besides Bi{sup 5+} induced narrowed bandgap and enhanced light adsorption capacity, significantly, the oxidative Bi{sup 5+} acts as electron traps to promote the photoexcited electron-hole separation and accelerate h{sup +} migration, resulting in the considerable photocatalytic enhancement of BiOBr-4 nanosheets. These novel findings will not only give new insights into the photocatalytic mechanism but also explore new route to enhance photocatalytic performance of Bi-based materials.

  18. Thermal gravimetric analysis of the CsCuCl3, Cs2CuCl4 and Cs2CuCl4x2H2O crystals

    International Nuclear Information System (INIS)

    Soboleva, L.V.; Vasil'eva, M.G.

    1977-01-01

    The thermal characteristics of crystals of Cs 2 CuCl 4 , Cs 2 CuCl 4 x2H 2 O, and CsCuCl 3 were investigated thermogravimetrically. The derivatogram of the Cs 2 CuCl 4 crystal is characterized by the presence of a single endothermal effect at 505 deg C. The derivatogram of the Cs 2 CuCl 4 x2H 2 O crystal contains three endothermal effects: at 40, 135, and 480 deg C. The derivatogram of the CsCuCl 3 crystal shows the presence of two endothermal effects at 142 and 455 deg C. The thermogravimetric data on Cs 2 CuCl 4 and CsCuCl 3 crystals reveal crystal decomposition on melting; hence, these crystals cannot be grown from melts

  19. Role of P-glycoprotein on CD69+CD4+ cells in the pathogenesis of proliferative lupus nephritis and non-responsiveness to immunosuppressive therapy.

    Science.gov (United States)

    Tsujimura, Shizuyo; Adachi, Tomoko; Saito, Kazuyoshi; Tanaka, Yoshiya

    2017-01-01

    P-glycoprotein (P-gp) expression on activated lymphocytes in systemic lupus erythematosus (SLE) plays a role in active efflux of intracellular drugs, resulting in drug resistance. The role of P-gp-expressing lymphocytes in the pathogenesis of SLE remains unclear. The aim of this study was to determine the importance of P-gp + CD4 + cells in organ manifestations in refractory SLE. The proportion of P-gp + CD4 + cells was determined by flow cytometry in peripheral blood of patients with SLE (n=116) and healthy adults (n=10). Renal biopsy specimens were examined by immunohistochemistry for P-gp expression. CD69 is a marker of CD4 cell activation. The proportion of both P-gp-expressing CD4 + cells and CD69-expressing CD4 + cells in peripheral blood was higher in SLE than control. The proportion of P-gp + CD69 + CD4 + cells correlated with Systemic Lupus Erythematosus Disease Activity Index and was higher in poor responders to corticosteroids. Furthermore, the proportion of P-gp + CD69 + CD4 + cells was significantly higher in proliferative lupus nephritis (LN) with poor response to corticosteroids. The efficacy of immunosuppressive therapy depended on the regulation of the proportion of P-gp + CD69 + CD4 + cells. Marked accumulation of P-gp + CD4 + cells in renal interstitial tissue and high proportion of peripheral P-gp + CD69 + CD4 + cells were noted in patients with proliferative LN. The results showed high proportion of P-gp + CD69 + CD4 + cells in peripheral blood and their accumulation in renal tissue in patients with proliferative LN refractory to CS therapy, suggesting that P-gp expression on activated CD4 + T cells is a potentially useful marker for refractoriness to treatment and a novel target for treatment.

  20. Bi3+–Pr3+ energy transfer processes and luminescent properties of LuAG:Bi,Pr and YAG:Bi,Pr single crystalline films

    International Nuclear Information System (INIS)

    Zorenko, Y.; Gorbenko, V.; Savchyn, V.; Zorenko, T.; Nikl, M.; Mares, J.A.; Beitlerova, A.; Jary, V.

    2013-01-01

    Absorption, cathodoluminescence, excitation spectra of photoluminescence (PL) and PL decay kinetics were studied at 300 K for the double doped with Bi 3+ –Pr 3+ and separately doped with Bi 3+ and Pr 3+ Lu 3 Al 5 O 12 (LuAG) and Y 3 Al 5 O 12 (YAG) single crystalline film (SCF) phosphors grown by the liquid phase epitaxy method. The emission bands in the UV range arising from the intrinsic radiative transitions of Bi 3+ based centers, and emission bands in the visible range, related to the luminescence of excitons localized around Bi 3+ based centers, were identified both in Bi–Pr and Bi-doped LuAG and YAG SCFs. The energy transfer processes from the host lattice simultaneously to Bi 3+ and Pr 3+ ions and from Bi 3+ to Pr 3+ ions were investigated. Competition between Pr 3+ and Bi 3+ ions in the energy transfer processes from the LuAG and YAG hosts was evidenced. The strong decrease of the intensity of Pr 3+ luminescence both in LuAG:Pr and YAG:Pr SCFs phosphors, grown from Bi 2 O 3 flux, is observed due to the quenching influence of Bi 3+ flux related impurity. Due to overlap of the UV emission band of Bi 3+ centers with the f–d absorption bands of Pr 3+ ions in the UV range and the luminescence of excitons localized around Bi ions with the f–f absorption bands of Pr 3+ ions in the visible range, an effective energy transfer from Bi 3+ ions to Pr 3+ ions takes place in LuAG:Bi,Pr and YAG:Bi,Pr SCFs, resulting in the appearance of slower component in the decay kinetics of the Pr 3+ d–f luminescence. -- Highlights: • Bi and Pr doped film phosphor grown by liquid phase epitaxy method. • Energy transfer from Bi 3+ to Pr 3+ ions. • Strong quenching of the Pr 3+ luminescence by Bi 3+ co-dopant

  1. Facile Fabrication of BiOI/BiOCl Immobilized Films with Improved Visible Light Photocatalytic Performance

    Science.gov (United States)

    Zhong, Yingxian; Liu, Yuehua; Wu, Shuang; Zhu, Yi; Chen, Hongbin; Yu, Xiang; Zhang, Yuanming

    2018-03-01

    Photocatalysis has been considered to be one of the most promising ways to photodegrade organic pollutants. Herein, a series of BiOI/BiOCl films coating on FTO were fabricated through a simple method at room temperature. The photocatalytic efficiency of 30%BiOI/BiOCl could reach more than 99% aiming to degrading RhB and MB after 90 and 120 min, respectively. Compared with BiOCl, 30%BiOI/BiOCl showed 12 times higher efficiency when degrading RhB. In comparison with BiOI, 30%BiOI/BiOCl showed 5 and 6 times higher efficiency when degrading RhB and MB, respectively. These obvious enhancements were attributed to expanded visible light absorption and high separation performance of photoinduced charge. Moreover, the photocatalytic activity of 30%BiOI/BiOCl had no obvious decrease after 5 recycles, suggesting that it was a promising photocatalyst for the removal of MB and RhB pollutants. Finally, the possible growth process for the BiOI/BiOCl thin films and photocatalysis mechanism were investigated in details. This work would provide insight to the reasonable construction of BiOX heterojunction and the photocatalytic mechanism in degrading organic pollutants.

  2. 135Cs/137Cs isotopic composition of environmental samples across Europe: Environmental transport and source term emission applications

    International Nuclear Information System (INIS)

    Snow, Mathew S.; Snyder, Darin C.

    2016-01-01

    135 Cs/ 137 Cs isotopic analyses represent an important tool for studying the fate and transport of radiocesium in the environment; in this work the 135 Cs/ 137 Cs isotopic composition in environmental samples taken from across Europe is reported. Surface soil and vegetation samples from western Russia, Ukraine, Austria, and Hungary show consistent aged thermal fission product 135 Cs/ 137 Cs isotope ratios of 0.58 ± 0.01 (age corrected to 1/1/15), with the exception of one sample of soil-moss from Hungary which shows an elevated 135 Cs/ 137 Cs ratio of 1.78 ± 0.12. With the exception of the outlier sample from Hungary, surface soil/vegetation data are in quantitative agreement with values previously reported for soils within the Chernobyl exclusion zone, suggesting that radiocesium at these locations is primarily composed of homogenous airborne deposition from Chernobyl. Seawater samples taken from the Irish Sea show 135 Cs/ 137 Cs isotope ratios of 1.22 ± 0.11 (age corrected to 1/1/15), suggesting aged thermal fission product Cs discharged from Sellafield. The differences in 135 Cs/ 137 Cs isotope ratios between Sellafield, Chernobyl, and global nuclear weapons testing fallout indicate that 135 Cs/ 137 Cs isotope ratios can be utilized to discriminate between and track radiocesium transport from different nuclear production source terms, including major emission sources in Europe. - Highlights: • 135 Cs/ 137 Cs useful for tracking anthropogenic environmental radiocesium releases. • European surface soils/vegetation have uniform ratio consistent with Chernobyl. • 135 Cs/ 137 Cs in Irish sea represents thermal fission ratio distinct from Chernobyl. • Can distinguish between major source terms in Europe based on 135 Cs/ 137 Cs.

  3. Reactive barriers for 137Cs retention

    International Nuclear Information System (INIS)

    Krumhansl, James L.; Brady, Patrick V.; Anderson, Howard L.

    2000-01-01

    137 Cs was dispersed globally by cold war activities and, more recently, by the Chernobyl accident. Engineered extraction of 137 Cs from soils and groundwaters is exceedingly difficult. Because the half life of 137 Cs is only 30.2 years, remediation might be more effective (and less costly) if 137 Cs bioavailability could be demonstrably limited for even a few decades by use of a reactive barrier. Essentially permanent isolation must be demonstrated in those few settings where high nuclear level wastes contaminated the environment with 135 Cs (half life 2.3x10 6 years) in addition to 137 Cs. Clays are potentially a low-cost barrier to Cs movement, though their long-term effectiveness remains untested. To identify optimal clays for Cs retention Cs resorption was measured for five common clays: Wyoming Montmorillonite (SWy-1), Georgia Kaolinites (KGa-1 and KGa-2), Fithian Illite (F-Ill), and K-Metabentonite (K-Mbt). Exchange sites were pre-saturated with 0.16 M CsCl for 14 days and readily exchangeable Cs was removed by a series of LiNO 3 and LiCl washes. Washed clay were then placed into dialysis bags and the Cs release to the deionized water outside the bags measured. Release rates from 75 to 139 days for SWy-1, K-Mbt and F- 111 were similar; 0.017 to 0.021% sorbed Cs released per day. Both kaolinites released Cs more rapidly (0.12 to 0.05% of the sorbed Cs per day). In a second set of experiments, clays were doped for 110 days and subjected to an extreme and prolonged rinsing process. All the clays exhibited some capacity for irreversible Cs uptake so most soils have some limited ability to act as a natural barrier to Cs migration. However, the residual loading was greatest on K-Mbt (∼ 0.33 wt% Cs). Thus, this clay would be the optimal material for constructing artificial reactive barriers

  4. Structural and optical properties of Bi2O3-B2O3-CdO-Na2O glass system for gamma ray shielding applications

    Science.gov (United States)

    Dogra, Mridula; Singh, K. J.; Kaur, Kulwinder

    2018-05-01

    Quaternary system of the composition (0.15+x) Bi2O3-(0.55-x) B2O3-0.15CdO-0.15Na2O (where x=0, 0.1, 0.3 and 0.5 mole fraction) has been synthesized using melt-quenching technique. Gamma ray shielding properties are measured in terms of mass attenuation coefficient and half value layer at photon energies 662, 1173 and 1332 keV. These parameters are compared with standard nuclear radiation shielding `barite and ferrite' concretes. The results reflect better radiation shielding properties as compared to barite and ferrite concretes. Effective atomic number is calculated at photon energies 662 and 1173 keV. Density, molar volume and XRD studies are analyzed to know physical and structural properties of the glass system. Optical band gap, refractive index and molar refraction are calculated from UV-Visible measurements. Decrease in optical band gap and increase in molar refraction have been observed indicating the increase of non-bridging oxygens in the structure.

  5. Defect and structural imperfection effects on the electronic properties of BiTeI surfaces

    International Nuclear Information System (INIS)

    Fiedler, Sebastian; Seibel, Christoph; Lutz, Peter; Bentmann, Hendrik; Reinert, Friedrich; El-Kareh, Lydia; Bode, Matthias; Eremeev, Sergey V; Tereshchenko, Oleg E; Kokh, Konstantin A; Chulkov, Evgueni V; Kuznetsova, Tatyana V; Grebennikov, Vladimir I

    2014-01-01

    The surface electronic structure of the narrow-gap seminconductor BiTeI exhibits a large Rashba-splitting which strongly depends on the surface termination. Here we report on a detailed investigation of the surface morphology and electronic properties of cleaved BiTeI single crystals by scanning tunneling microscopy, photoelectron spectroscopy (ARPES, XPS), electron diffraction (SPA-LEED) and density functional theory calculations. Our measurements confirm a previously reported coexistence of Te- and I-terminated surface areas originating from bulk stacking faults and find a characteristic length scale of ∼100 nm for these areas. We show that the two terminations exhibit distinct types of atomic defects in the surface and subsurface layers. For electronic states resided on the I terminations we observe an energy shift depending on the time after cleavage. This aging effect is successfully mimicked by depositon of Cs adatoms found to accumulate on top of the I terminations. As shown theoretically on a microscopic scale, this preferential adsorbing behaviour results from considerably different energetics and surface diffusion lengths at the two terminations. Our investigations provide insight into the importance of structural imperfections as well as intrinsic and extrinsic defects on the electronic properties of BiTeI surfaces and their temporal stability. (paper)

  6. On the electronic structure and thermoelectric properties of BiTeBr and BiTeI single crystals and of BiTeI with the addition of BiI3 and CuI

    International Nuclear Information System (INIS)

    Kulbachinskii, Vladimir A.; Kytin, Vladimir G.; Kudryashov, Alexey A.; Kuznetsov, Alexei N.; Shevelkov, Andrei V.

    2012-01-01

    The electronic structures were calculated for BiTeBr and BiTeI using the density-functional theory approach and accounting for the strong spin–orbital interaction. Qualitatively, the band structures for two compounds are similar, showing strong mixing of the p states of all elements in vicinity of the Fermi level, with the band gaps of 0.595 and 0.478 eV for BiTeBr and BiTeI, respectively. The optimized crystal structures show a tendency for the Bi–X (X=Br, I) bond elongation compared to the Bi–Te one. Both compounds are intrinsic n-type semiconductors but display a metallic-like conductivity coupled to rather large thermopower, which is rationalized within the frames of the acoustic phonons scattering model. Because of larger thermopower BiTeBr exhibits a twice higher thermoelectric figure-of-merit near room temperature, ZT=0.17, compared to BiTeI. The addition of 1 mass% of BiI 3 or CuI to BiTeI decreases the mobility of electrons by two orders of magnitude, leading to significantly lower electrical conductivity, but at the same time effectively reduces the thermal conductivity. The prospects of further enhancing the thermoelectric efficiency are briefly discussed. - Graphical abstract: View of the crystal structure of BiTeBr is shown in the figure The optimized crystal structures show a tendency for the Bi–X (X=Br, I) bond elongation compared to the Bi–Te one. The electronic structures were calculated for BiTeBr and BiTeI using the density-functional theory approach and accounting for the strong spin–orbital interaction. Qualitatively, the band structures for two compounds are similar, showing strong mixing of the p states of all elements in vicinity of the Fermi level, with the band gaps of 0.595 and 0.478 eV for BiTeBr and BiTeI, respectively. Both compounds are intrinsic n-type semiconductors but display a metallic-like conductivity coupled to rather large thermopower, which is rationalized within the frames of the acoustic phonons scattering

  7. 137Cs in man organism

    International Nuclear Information System (INIS)

    Marej, A.N.; Barkhudarov, R.M.

    1980-01-01

    Considered are the levels of 137 Cs content in the organism of adult urban population of the USSR and the main regularities of their alterations during 1962-1974. The non-uniform distribution of levels of 137 Cs buildup in adult population is shown to be connected with soil and geographic conditions. Food stuffs of local production have a noticeable effect on the levels of 137 Cs buildup in the organism of urban population. Calculation methods are used to study 137 Cs administration in a human organism. No significant difference is found between the indexes of 137 Cs content in the organism of rural and urban population. Presented are the levels of 137 Cs content in the organisms of inhabitants of such regions as Far North and Byelorussian-Ukrainian woodlands. Given are the reasons for the increased content of 137 Cs in the organism of rural population of these zones

  8. Development of surgical gamma probes with TlBr semiconductors and CsI(Tl) scintillators crystals

    International Nuclear Information System (INIS)

    Costa, Fabio Eduardo da

    2006-01-01

    Radio guided surgery, using probes with radiation detectors, has been prominence in the medical area in the last decade. This technique consists in injecting a radioactive substance to concentrate in tumour and assist the localization during the surgical procedure. The radio guided surgeries allowing the identification of lymph node has revolutioned the behavior of tumour in initial stadium when are being spread by lymphatic way. The conditions imposed to the surgery due the proximity between some lymph nodes, demands of the probes, a small diameters and capacity of individual identification of these lymph nodes radiolabelled by a specific tracer. The international market supplies these probes with CdTe semiconductors and scintillators, but there is some time lack a promptly technical assistance in the Brazilian market. This work developed probes with national technology, using CsI(Tl) scintillators crystals and, in substitution to CdTe crystals semiconductors, the TlBr crystal, that is a new semiconductor detector in a world-wide development, with advantages in relation to the CdTe. Both crystals have been grown in IPEN. All the necessary electronics, specially, the preamplifier, that was also a restrictive factor for development of these types of probe in the country, have been developed with components found in the national market. Systematic measures of spatial resolution, spatial selectivity, maximum sensitivity and quality of the shielding have been carried the probes development. The results have shown that the probes, one with the CsI(Tl) crystal and another with TlBr semiconductor presented the requested performance in the international literature for radio guided probes. (author)

  9. Does pretransplant soluble CD30 serum concentration affect deceased-donor kidney graft function 3 years after transplantation?

    Science.gov (United States)

    Kovac, J; Arnol, M; Vidan-Jeras, B; Bren, A F; Kandus, A

    2008-06-01

    Elevated serum concentrations of soluble CD30 molecule (sCD30) have been related to acute cellular rejection and poor graft outcomes in kidney transplantation. This historical cohort study investigated the association of pretransplant sCD30 serum concentrations with kidney graft function expressed as estimated glomerular filtration rate (GFR) at 3 years after transplantation. Pretransplant sera from 176 adult deceased-donor kidney graft recipients were tested for sCD30 content using a commercially available automated enzyme-linked immunosorbent assay. The immunosuppression consisted of induction therapy with monoclonal anti-CD25 antibodies and a maintenance regimen of cyclosporine (CsA)-based therapy. GFR was estimated (eGFR) by the four-variable Modification of Diet in Renal Disease (MDRD) Study equation. According to the distribution of pretransplant sCD30 levels (median 66.7 U/mL; interquartile range, 46.6 to 98.6 U/mL), a concentration of 66 U/mL or higher was defined as high (n = 89) and below 66 U/mL as low (n = 87). Three years after transplantation, eGFR was not significantly different among recipients in high versus low sCD30 groups (69 +/- 23 mL/min/1.73m2 vs 66 +/- 21 mL/min/1.73m2; P = .327) and there was no correlation between eGFR and pretransplant sCD30 levels (r2 = 0.001; P = .73). Upon multivariate regression analysis, donor age, recipient body mass index at transplantation, and acute rejection episodes were independent variables affecting eGFR at 3 years after transplantation. This study showed that pretransplant sCD30 serum concentrations were not associated with deceased-donor kidney graft function at 3 years after transplantation. The immunosuppression with anti-CD25 antibodies and a triple CsA-based maintenance regimen could possibly be decisive for our findings.

  10. Exploring Polaronic, Excitonic Structures and Luminescence in Cs4PbBr6/CsPbBr3.

    Science.gov (United States)

    Kang, Byungkyun; Biswas, Koushik

    2018-02-15

    Among the important family of halide perovskites, one particular case of all-inorganic, 0-D Cs 4 PbBr 6 and 3-D CsPbBr 3 -based nanostructures and thin films is witnessing intense activity due to ultrafast luminescence with high quantum yield. To understand their emissive behavior, we use hybrid density functional calculations to first compare the ground-state electronic structure of the two prospective compounds. The dispersive band edges of CsPbBr 3 do not support self-trapped carriers, which agrees with reports of weak exciton binding energy and high photocurrent. The larger gap 0-D material Cs 4 PbBr 6 , however, reveals polaronic and excitonic features. We show that those lattice-coupled carriers are likely responsible for observed ultraviolet emission around ∼375 nm, reported in bulk Cs 4 PbBr 6 and Cs 4 PbBr 6 /CsPbBr 3 composites. Ionization potential calculations and estimates of type-I band alignment support the notion of quantum confinement leading to fast, green emission from CsPbBr 3 nanostructures embedded in Cs 4 PbBr 6 .

  11. A study of 137Cs in soil profiles from the Marshall Islands

    International Nuclear Information System (INIS)

    Graham, J.C.; Simon, S.L.

    1996-01-01

    In late 1989, the Republic of the Marshall Islands commissioned an independent radiological monitoring program to determine the degree of deposition and the geographical extent of atomic weapons test fallout over its islands. The sampling and measurement of 137 Cs in vertical soil profiles has been an important part of that monitoring program. Over 200 profiles were collected in 5-cm increments to a depth of 30 cm, including locations at all 29 of the nation's atolls and five separate reef islands. Annual rainfall and soil particle size distribution was studied to determine the inter-relationships with cesium permeation and areal inventory (Bq/m 2 ). Relaxation lengths of cesium in the soil column were calculated from measurements of 137 Cs activity in profile increments. Using a common model for a depth-dependent concentration gradient (C(d) C o e -αd ), the inverse of the rate of change of concentration (i.e. 1/α) has been defined as the relaxation length of the profile. In this study, the relaxation length was calculated from the concentration data of the first three sample increments (i.e. 0 - 5, 5 - 10, 10 - 15 cm) and from all six increments to a total depth of 30 cm. Typical values for relaxation lengths in the drier northern atolls are 7 - 12 cm, though our observations included values between -800 and 3500 cm. Our findings showed that 137 Cs permeation was highly variable with particle size, though relaxation length was significantly correlated with annual rainfall. Areal inventory was determined to be significantly correlated with the 0 - 5 cm 137 Cs soil concentration. The 0 - 30 cm fitted relaxation length was also determined to give a good estimate of the areal inventory of 137 Cs in the soil to a depth of 30 cm regardless of the rate of change in concentration with depth

  12. Preparation, characterization and enhanced visible-light photocatalytic activities of BiPO4/BiVO4 composites

    International Nuclear Information System (INIS)

    Wu, Siyuan; Zheng, Hong; Lian, Youwei; Wu, Yiying

    2013-01-01

    Graphical abstract: - Highlights: • BiPO 4 /BiVO 4 composites were successfully prepared by the hydrothermal method. • BiPO 4 /BiVO 4 composites exhibited broad absorption in the visible region. • Visible-light photocatalytic activities of BiPO 4 /BiVO 4 composites were enhanced. • P/V molar ratio and pH value of the reaction affect photocatalytic activity. • The mechanism of enhanced visible-light photocatalytic activities was discussed. - Abstract: BiPO 4 /BiVO 4 composites with different P/V molar ratios were prepared by the hydrothermal method and the effect of pH values of hydrothermal reaction on photocatalytic activity of BiPO 4 /BiVO 4 composite was investigated. The photocatalysts were characterized by X-ray diffraction, field emission scanning electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectroscopy and UV–vis diffuse reflectance spectroscopy. The photocatalytic property of BiPO 4 /BiVO 4 was evaluated by photocatalytic degradation of Methylene blue under visible light irradiation. The results showed that the photocatalytic activity of the composites was much higher than that of pure BiPO 4 and BiVO 4 . The rate constant of Methylene blue degradation over BiPO 4 /BiVO 4 (P/V molar ratio of 5:1 and hydrothermal reaction pH value of 1.5) is 1.7 times that of pure BiVO 4 . The photocatalytic activity enhancement of BiPO 4 /BiVO 4 composite is closely related to the BiVO 4 functioning as a sensitizer to adsorb visible light and the heterojunction of BiPO 4 /BiVO 4 acting as an active center for hindering the rapid recombination of electron–hole pairs during the photocatalytic reaction

  13. Crystal scintillators for use in check-light source for thermoluminescent systems

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, J.S.; Sabharwal, S.C.; Chougaonkar, M.P.; Godbole, S.V

    1999-08-11

    Beta ({sup 63}Ni, E{sub max} 0.063 MeV) excited radioluminescence of indigenously grown crystal scintillators CsI(Tl), Bi{sub 4}Ge{sub 3}O{sub 12} and CdWO{sub 4} has been studied for its use in check-light source needed for thermoluminescence systems. Temperature coefficient of the light output over 298-323 K and the beta-induced TL of the scintillators over 298-553 K are reported. (author)

  14. Spatial profile of thermoelectric effects during Peltier pulsing in Bi and Bi/MnBi eutectic

    Science.gov (United States)

    Silberstein, R. P.; Larson, D. J., Jr.

    1987-01-01

    The spatial profile of the thermal transients that occur during and following the current pulsing associated with Peltier Interface Demarcation during directional solidification is studied. Results for pure Bi are presented in detail and compared with corresponding results for the Bi/MnBi eutectic. Significant thermal transients occur throughout the sample that can be accounted for by the Peltier effect, the Thomson effect, and Joule heating. These effects are separated and their behavior is studied as a function of time, current density, and position with respect to the solid/liquid interface.

  15. Synthesis and chemistry of the new Y-Based and Bi-Based high temperature superconducting perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Tarascon, J.M.; Barboux, P.; Miceli, P.F.; Bagley, B.G.; Greene, L.H.; Hull, G.W.; Giroud, M.

    1988-12-01

    Chemical synstesis of the new high T{sub c} oxides using solid state reactions or solution techniques is shown. A solution process which allows the preparation of both homogeneous and dense ceramics and of superconducting thick films has been developed for the YBa{sub 2}Cu{sub 3}O{sub 7} system. Physical measurements performed on homogeneous YBa{sub 2}Cu{sub 3-x}Co{sub x}O{sub y} samples have shown that the Co substitution, associated with an uptake of oxygen, takes place on the Cu-O chains and that T{sub c} is depressed, leading ultimately to antiferromagnetic insulators whose magnetic structures are shown. Three phases of general formula Bi{sub 2}Sr{sub 2}Ca{sub n-1}Cu{sub n}O{sub y} with n = 1,2 and 3 have been isolated in the Bi system and characterized for their structural and physical properties. These phases crystallize in the same pseudotetragonal unit cell differing one from the next by the stacking sequence along the c-axis, with the main feature being the presence of a sheared Bi-O double layer. The T{sub c}s of the n = 1,2 and 3 phases are 10 K, 85 K and 110 K respectively, but because of phase intergrowth, these values depend upon sample processing, making chemical substitutions within the Bi system quite complex as is discussed. Finally, we succeeded in making superconducting thick films (having zero resistance around 100 K) of the Bi-based and T1-based matrials via the decomposition of aqueous-glycerol solutions containing the salts of the elements.

  16. State diagram of Pr-Bi system

    International Nuclear Information System (INIS)

    Abulkhaev, V.L.; Ganiev, I.N.

    1994-01-01

    By means of thermal differential analysis, X-ray and microstructural analysis the state diagram of Pr-Bi system was studied. Following intermetallic compounds were defined in the system: Pr 2 Bi, Pr 5 Bi 3 , Pr 4 Bi 3 , Pr Bi, PrBi 2 , Pr 2 Bi, Pr 5 Bi 3 , Pr 4 Bi 3 and PrBi 2 . The data analysis on Ln-Bi diagram allowed to determine the regularity of change of properties of intermetallic compounds in the line of rare earth elements of cerium subgroup.

  17. Temperature and Pressure Dependence of the Reaction S plus CS (+M) -> CS2 (+M)

    DEFF Research Database (Denmark)

    Glarborg, Peter; Marshall, Paul; Troe, Juergen

    2015-01-01

    Experimental data for the unimolecular decomposition of CS2 from the literature are analyzed by unimolecular rate theory with the goal of obtaining rate constants for the reverse reaction S + CS (+M) -> CS2 (+M) over wide temperature and pressure ranges. The results constitute an important input...

  18. Core-Shell Zn x Cd1- x Se/Zn y Cd1- y Se Quantum Dots for Nonvolatile Memory and Electroluminescent Device Applications

    Science.gov (United States)

    Al-Amoody, Fuad; Suarez, Ernesto; Rodriguez, Angel; Heller, E.; Huang, Wenli; Jain, F.

    2011-08-01

    This paper presents a floating quantum dot (QD) gate nonvolatile memory device using high-energy-gap Zn y Cd1- y Se-cladded Zn x Cd1- x Se quantum dots ( y > x) with tunneling layers comprising nearly lattice-matched semiconductors (e.g., ZnS/ZnMgS) on Si channels. Also presented is the fabrication of an electroluminescent (EL) device with embedded cladded ZnCdSe quantum dots. These ZnCdSe quantum dots were embedded between indium tin oxide (ITO) on glass and a top Schottky metal electrode deposited on a thin CsF barrier. These QDs, which were nucleated in a photo-assisted microwave plasma (PMP) metalorganic chemical vapor deposition (MOCVD) reactor, were grown between the source and drain regions on a p-type silicon substrate of the nonvolatile memory device. The composition of QD cladding, which relates to the value of y in Zn y Cd1- y Se, was engineered by the intensity of ultraviolet light, which controlled the incorporation of zinc in ZnCdSe. The QD quality is comparable to those deposited by other methods. Characteristics and modeling of the II-VI quantum dots as well as two diverse types of devices are presented in this paper.

  19. Pretransplant soluble CD30 serum concentration does not affect kidney graft outcomes 3 years after transplantation.

    Science.gov (United States)

    Kovač, J; Arnol, M; Vidan Jeras, B; Bren, A F; Kandus, A

    2010-12-01

    An elevated serum concentration of soluble the form of CD30 (sCD30), an activation marker of mainly T(H)2-type cytokines producing T lymphocytes, has been reported as a predictive factor for acute cellular rejection episodes and poor graft outcomes in kidney transplantation. This historic cohort study investigated the association of a pretransplant sCD30 serum concentrations with kidney graft function and graft survival 3 years posttransplantation in adult recipients of deceased donor kidney grafts, treated with monoclonal anti-CD25 antibodies as an induction treatment combined with a cyclosporine (CsA)-based maintenance triple therapy. The pretransplant sera of 296 recipients were tested for sCD30 content using a microsphere flow-cytometry assay. The estimated glomerular filtration rate (eGFR) was determined by the 4-variable Modification of Diet in Renal Disease equation. The incidences of graft loss were calculated with the use of Kaplan-Meier survival analysis and compared using the log-rank test. According to the distribution of the pretransplant sCD30 levels concentration ≥2700 pg/mL was defined as high (n = 146) and concentration sCD30 groups (65 ± 24 vs 67 ± 21 mL/min/1.73 m(2); P = .43); there was no association between the eGFR 3 years after transplantation and the pretransplant sCD30 levels (r(2) = 0.002; P = .49). Graft survival 3 years after transplantation was also not different in the recipients in high and low sCD30 groups (P = .52). In our adult deceased-donor kidney graft recipients, the pretransplant sCD30 serum concentration was not a predictive factor of immunologic risk associated with the kidney graft function 3 years posttransplantation; neither did it affect graft survival 3 years after transplantation. The immunosuppression with anti-CD25 antibodies as an induction treatment combined with the CsA-based maintenance triple therapy could possibly be decisive for our findings. Copyright © 2010 Elsevier Inc. All rights reserved.

  20. A simple method for the deconvolution of 134 Cs/137 Cs peaks in gamma-ray scintillation spectrometry

    International Nuclear Information System (INIS)

    Darko, E.O.; Osae, E.K.; Schandorf, C.

    1998-01-01

    A simple method for the deconvolution of 134 Cs / 137 Cs peaks in a given mixture of 134 Cs and 137 Cs using Nal(TI) gamma-ray scintillation spectrometry is described. In this method the 795 keV energy of 134 Cs is used as a reference peak to calculate the activity of the 137 Cs directly from the measured peaks. Certified reference materials were measured using the method and compared with a high resolution gamma-ray spectrometry measurements. The results showed good agreement with the certified values. The method is very simple and does not need any complicated mathematics and computer programme to de- convolute the overlapping 604.7 keV and 661.6 keV peaks of 134 Cs and 137 Cs respectively. (author). 14 refs.; 1 tab., 2 figs

  1. One-step growth of nanosheet-assembled BiOCl/BiOBr microspheres for highly efficient visible photocatalytic performance

    Science.gov (United States)

    Zhang, Jinfeng; Lv, Jiali; Dai, Kai; Liang, Changhao; Liu, Qi

    2018-02-01

    In this work, we have developed a simple synthetic approach of nanosheet-assembled BiOCl/BiOBr microspheres by an ethylene glycol (EG)-assisted hydrothermal method. The crystalline form, morphology, chemical composition, optical performance and surface area of BiOCl/BiOBr microspheres were identified using X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution TEM (HRTEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy spectra (EDX), UV-vis diffuse reflectance spectroscopy (DRS) analysis, high resolution X-ray photoelectron spectra (XPS) and N2 adsorption-desorption isotherms. BiOCl/BiOBr microspheres were nanosheet-assembled particles, which possessed visible light absorption under LED light irridation. Additionally, the methylene blue (MB) photodegradation performance of different BiOCl/BiOBr microspheres irradiated under 410 nm LED light arrays were investigated, the results exhibited that as-prepared BiOCl/BiOBr products showed higher catalytic effiency than pure BiOCl or BiOBr. By optimizing the composition ration of the BiOCl and BiOBr, up to 93% degradation rate can be obtained in the 40%BiOCl/BiOBr microspheres. Finally, the photocatalytic mechanism of BiOCl/BiOBr microspheres had been proposed.

  2. Tunable CsPbBr3/Cs4PbBr6 phase transformation and their optical spectroscopic properties.

    Science.gov (United States)

    Chen, Xiao; Chen, Daqin; Li, Junni; Fang, Gaoliang; Sheng, Hongchao; Zhong, Jiasong

    2018-04-24

    As a novel type of promising materials, metal halide perovskites are a rising star in the field of optoelectronics. On this basis, a new frontier of zero-dimensional perovskite-related Cs4PbBr6 with bright green emission and high stability has attracted an enormous amount of attention, even though its photoluminescence still requires to clarification. Herein, the controllable phase transformation between three-dimensional CsPbBr3 and zero-dimensional Cs4PbBr6 is easily achieved in a facile ligand-assisted supersaturated recrystallization synthesis procedure via tuning the amount of surfactants, and their unique optical properties are investigated and compared in detail. Both Cs4PbBr6 and CsPbBr3 produce remarkably intense green luminescence with quantum yields up to 45% and 80%, respectively; however, significantly different emitting behaviors are observed. The fluorescence lifetime of Cs4PbBr6 is much longer than that of CsPbBr3, and photo-blinking is easily detected in the Cs4PbBr6 product, proving that the zero-dimensional Cs4PbBr6 is indeed a highly luminescent perovskite-related material. Additionally, for the first time, tunable emissions over the visible-light spectral region are demonstrated to be achievable via halogen composition modulations in the Cs4PbX6 (X = Cl, Br, I) samples. Our study brings a simple method for the phase control of CsPbBr3/Cs4PbBr6 and demonstrates the intrinsic luminescence nature of the zero-dimensional perovskite-related Cs4PbX6 products.

  3. Microhydration of caesium compounds: Cs, CsOH, CsI and Cs₂I₂ complexes with one to three H₂O molecules of nuclear safety interest.

    Science.gov (United States)

    Sudolská, Mária; Cantrel, Laurent; Cernušák, Ivan

    2014-04-01

    Structure and thermodynamic properties (standard enthalpies of formation and Gibbs free energies) of hydrated caesium species of nuclear safety interest, Cs, CsOH, CsI and its dimer Cs₂I₂, with one up to three water molecules, are calculated to assess their possible existence in severe accident occurring to a pressurized water reactor. The calculations were performed using the coupled cluster theory including single, double and non-iterative triple substitutions (CCSD(T)) in conjunction with the basis sets (ANO-RCC) developed for scalar relativistic calculations. The second-order spin-free Douglas-Kroll-Hess Hamiltonian was used to account for the scalar relativistic effects. Thermodynamic properties obtained by these correlated ab initio calculations (entropies and thermal capacities at constant pressure as a function of temperature) are used in nuclear accident simulations using ASTEC/SOPHAEROS software. Interaction energies, standard enthalpies and Gibbs free energies of successive water molecules addition determine the ordering of the complexes. CsOH forms the most hydrated stable complexes followed by CsI, Cs₂I₂, and Cs. CsOH still exists in steam atmosphere even at quite high temperature, up to around 1100 K.

  4. 1+ collective states of 124Cs and 126Cs nuclei

    International Nuclear Information System (INIS)

    Ivanova, S.P.; Kuliev, A.A.; Salamov, D.I.

    1977-01-01

    Within the framework of the random phase approximation β-decay properties of the 1 + states of 124 Cs and 126 Cs have been investigated. Greatly collectivized 1 + states in odd-odd nuclei are produced by the spin-dependent charge-exchange nucleon interaction. For numerical calculations the scheme of single-particle levels in the deformed Saxon-Woods potential has been used

  5. Characterization of freshwater bivalves as radio contamination (57Co, 110mAg, 134Cs) bio-indicators in a metallic multi pollution context (Cd, Zn)

    International Nuclear Information System (INIS)

    Fraysse, B.

    2001-07-01

    This study concerns freshwater bio-indicators of radio-contamination, in a metallic multi-pollution context. Metals, such as cadmium (Cd) and zinc (Zn), are widely represented in aquatic ecosystems, and their concentrations can induce physiological effects. This chronicle exposure generates both metabolic and behaviour stress of individuals, and can also yield to detoxification mechanisms induction. The main goal of this work was to estimate the influence of metals on the radionuclides ( 57 Co, 110m Ag, 134 Cs) bioaccumulation by two different bivalve species (Corbicula fluminea et Dreissena polymorpha), by studying the contamination level, the kinetic of the radionuclide transfer and the soft-body repartition. As the exploratory feature of this study, two parts have been developed: (i) testing the problematic suitability in a really bio-monitoring situation, and (ii) analysing the metal/radionuclide interaction mechanisms under controlled and standardised conditions (laboratory). For the different experimental conditions explored (laboratory and field), radionuclide bioaccumulation by freshwater bivalves has been influenced by metal exposure. This result was obtained after assessing a decrease of the organisms contamination level by radionuclide and their accumulation rate, an increase of their depuration rate and tissue and cellular repartition changes. (author)

  6. Chlordecone altered hepatic disposition of [14C]cholesterol and plasma cholesterol distribution but not SR-BI or ABCG8 proteins in livers of C57BL/6 mice

    International Nuclear Information System (INIS)

    Lee, Junga; Scheri, Richard C.; Curtis, Lawrence R.

    2008-01-01

    Organochlorine (OC) insecticides continue to occur in tissues of humans and wildlife throughout the world although they were banned in the United States a few decades ago. Low doses of the OC insecticide chlordecone (CD) alter hepatic disposition of lipophilic xenobiotics and perturb lipid homeostasis in rainbow trout, mice and rats. CD pretreatment altered tissue and hepatic subcellular distribution of exogenous [ 14 C]cholesterol (CH) equivalents 4 and 16 h after a bolus intraperitoneal (ip) injection of 5 ml corn oil/kg that contained 10 mg CH/kg. CD pretreatment altered tissue distribution of exogenously administered [ 14 C]CH by decreased hepatic and renal accumulation, and increased biliary excretion up to 300%. Biliary excretion of polar [ 14 C]CH metabolites was not altered by CD. CD pretreatment decreased subcellular distribution of [ 14 C]CH equivalents in hepatic cytosol and microsomes and lipoprotein-rich fraction-to-homogenate ratio. CD pretreatment increased the ratio of [ 14 C]CH equivalents in high density lipoprotein (HDL) to that in plasma and reduced [ 14 C]CH equivalents in the non-HDL fraction 4 h after a bolus lipid dose. CD pretreatment increased plasma non-HDL total CH by 80% 4 h after a bolus lipid dose. Scavenger receptor class B type I (SR-BI) and ATP-binding cassette transporter G8 (ABCG8) proteins were quantified by western blotting in hepatic membranes from control and CD treated mice. Liver membrane contents of SR-BI and ABCG8 proteins were unchanged by CD pretreatment. The data demonstrated that a single dose of CD altered CH homeostasis and lipoprotein metabolism

  7. Chlordecone altered hepatic disposition of [14C]cholesterol and plasma cholesterol distribution but not SR-BI or ABCG8 proteins in livers of C57BL/6 mice.

    Science.gov (United States)

    Lee, Junga; Scheri, Richard C; Curtis, Lawrence R

    2008-06-15

    Organochlorine (OC) insecticides continue to occur in tissues of humans and wildlife throughout the world although they were banned in the United States a few decades ago. Low doses of the OC insecticide chlordecone (CD) alter hepatic disposition of lipophilic xenobiotics and perturb lipid homeostasis in rainbow trout, mice and rats. CD pretreatment altered tissue and hepatic subcellular distribution of exogenous [(14)C]cholesterol (CH) equivalents 4 and 16 h after a bolus intraperitoneal (ip) injection of 5 ml corn oil/kg that contained 10 mg CH/kg. CD pretreatment altered tissue distribution of exogenously administered [(14)C]CH by decreased hepatic and renal accumulation, and increased biliary excretion up to 300%. Biliary excretion of polar [(14)C]CH metabolites was not altered by CD. CD pretreatment decreased subcellular distribution of [(14)C]CH equivalents in hepatic cytosol and microsomes and lipoprotein-rich fraction-to-homogenate ratio. CD pretreatment increased the ratio of [(14)C]CH equivalents in high density lipoprotein (HDL) to that in plasma and reduced [(14)C]CH equivalents in the non-HDL fraction 4 h after a bolus lipid dose. CD pretreatment increased plasma non-HDL total CH by 80% 4 h after a bolus lipid dose. Scavenger receptor class B type I (SR-BI) and ATP-binding cassette transporter G8 (ABCG8) proteins were quantified by western blotting in hepatic membranes from control and CD treated mice. Liver membrane contents of SR-BI and ABCG8 proteins were unchanged by CD pretreatment. The data demonstrated that a single dose of CD altered CH homeostasis and lipoprotein metabolism.

  8. Cesium platinide hydride 4Cs{sub 2}Pt.CsH: an intermetallic double salt featuring metal anions

    Energy Technology Data Exchange (ETDEWEB)

    Smetana, Volodymyr [Ames Laboratory, US Department of Energy, and Critical Materials Institute, Ames, Iowa, 50011-3020 (United States); Mudring, Anja-Verena [Ames Laboratory, US Department of Energy, and Critical Materials Institute, Ames, Iowa, 50011-3020 (United States); Department of Materials Sciences and Engineering, Iowa State University, Ames, Iowa, 50011-3111 (United States)

    2016-11-14

    With Cs{sub 9}Pt{sub 4}H a new representative of ionic compounds featuring metal anions can be added to this rare-membered family. Cs{sub 9}Pt{sub 4}H exhibits a complex crystal structure containing Cs{sup +} cations, Pt{sup 2-} and H{sup -} anions. Being a red, transparent compound its band gap is in the visible range of the electromagnetic spectrum and the ionic type of bonding is confirmed by quantum chemical calculations. This cesium platinide hydride can formally be considered as a double salt of the ''alloy'' cesium-platinum, or better cesium platinide, Cs{sub 2}Pt, and the salt cesium hydride CsH according to Cs{sub 9}Pt{sub 4}H≡4 Cs{sub 2}Pt.CsH. (copyright 2016 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Knudsen cell--mass spectrometer studies of cesium--urania interactions. [Cs/sub 2/CO/sub 3/ or CsOH

    Energy Technology Data Exchange (ETDEWEB)

    Collins, J.L.; Osborne, M.F.; Malinauskas, A.P.; Lorenz, R.A.; Manning, S.R.

    1976-06-01

    Limited Knudsen cell--mass spectrometer studies were made of the partial pressures of cesium-containing species (assumed to be primarily Cs(g)) over Cs/sub 2/CO/sub 3/ and over phase equilibria involving UO/sub 2/ and probable Cs-U-O compounds formed from mixtures that initially contained either Cs/sub 2/CO/sub 3/-UO/sub 2/ or CsOH-UO/sub 2/. Although additional work is required to further define the equilibria involved, the data demonstrate unambiguously a significant reduction in cesium partial pressures due to probable Cs-U-O compound formation and indicate essentially identical behavior with either CsOH or Cs/sub 2/CO/sub 3/ as the starting material with UO/sub 2/.

  10. Development of certified matrix reference materials for quality assurance of screening 134Cs and 137Cs in food

    International Nuclear Information System (INIS)

    Ishizu, H.; Yamada, T.

    2013-01-01

    A certified reference material using activated alumina powder certified for activity of 134 Cs and 137 Cs was developed. The results of the verification and the certification are described. The certified reference material can be used for quality assurance of screening activity measurements of 134 Cs and 137 Cs in food/foodstuffs. Commercially available equipments were experimentally tested using the CRM and another CRM including 40 K. The results of these tests are also shown. - Highlights: • CRM of 134 Cs and 137 Cs using activated alumina was developed. • CRM including 134 Cs, 137 Cs and 40 K was also developed. • Results of experimental performance test of commercial inspection equipments using CRMs were shown

  11. Ab Initio investigation of cesium monoxide of CsO and CsO+

    International Nuclear Information System (INIS)

    Zialenina, M.; Kelloe, V.; Cernusak, I.

    2015-01-01

    Cesium is material with a low work function and, accordingly, atomic Cs has a low value of ionization energy. Therefore cesium is regarded as a good source material for electrons in plasma heating module. One of plasma heating technologies using Cs grid is foreseen as a candidate for the tokamak within the framework of project ITER. Among the possible impurities that can coexist in this module are CsO or CsO + , due to presence of oxygen traces in the heating chamber. We conducted CCSD(T) energy calculations of the cesium oxide (X 2 Σ + ) and its cation (X 3 Σ - ). Here are presented the bond lengths and spectroscopic parameters of both species and ionization energy (IE). Our IE (6.88 eV) is in good agreement with previous theoretical results, experiment indicates substantially lower value (6.22 eV). (authors)

  12. Development of MnBi permanent magnet: Neutron diffraction of MnBi powder

    Energy Technology Data Exchange (ETDEWEB)

    Cui, J., E-mail: jun.cui@pnnl.gov; Choi, J. P.; Li, G.; Polikarpov, E.; Darsell, J. [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354 (United States); Kramer, M. J.; Zarkevich, N. A.; Wang, L. L.; Johnson, D. D. [Materials Sciences and Engineering Division, Ames Laboratory, Ames, Iowa 50011 (United States); Marinescu, M. [Electron Energy Corporation, Landisville, Pennsylvania 17538 (United States); Huang, Q. Z.; Wu, H. [NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102 (United States); Vuong, N. V.; Liu, J. P. [Department of Physics, University of Texas at Arlington, Arlington, Texas 76019 (United States)

    2014-05-07

    MnBi attracts great attention in recent years for its great potential as permanent magnet materials. MnBi phase is difficult to obtain because of the rather drastic peritectic reaction between Mn and Bi. In this paper, we report our effort on synthesizing high purity MnBi compound using conventional powder metallurgical approaches. Neutron diffraction was carried out to investigate the crystal and nuclear structure of the obtained powder. The result shows that the purity of the obtained powder is about 91 wt. % at 300 K, and the magnetic moment of the Mn atom in MnBi lattice is 4.424 and 4.013 μ{sub B} at 50 K and 300 K, respectively.

  13. Development of MnBi permanent magnet: Neutron diffraction of MnBi powder

    Energy Technology Data Exchange (ETDEWEB)

    Cui, J; Choi, JP; Li, G; Polikarpov, E; Darsell, J; Kramer, MJ; Zarkevich, NA; Wang, LL; Johnson, DD; Marinescu, M; Huang, QZ; Wu, H; Vuong, NV; Liu, JP

    2014-05-07

    MnBi attracts great attention in recent years for its great potential as permanent magnet materials. MnBi phase is difficult to obtain because of the rather drastic peritectic reaction between Mn and Bi. In this paper, we report our effort on synthesizing high purity MnBi compound using conventional powder metallurgical approaches. Neutron diffraction was carried out to investigate the crystal and nuclear structure of the obtained powder. The result shows that the purity of the obtained powder is about 91 wt. % at 300 K, and the magnetic moment of the Mn atom in MnBi lattice is 4.424 and 4.013 mu(B) at 50 K and 300 K, respectively. (C) 2014 AIP Publishing LLC.

  14. Luminescence properties of undoped CsCaCl3 and CsSrCl3 crystalline scintillators

    International Nuclear Information System (INIS)

    Fujimoto, Yutaka; Saeki, Keiichiro; Koshimizu, Masanori; Asai, Keisuke; Yanagida, Takayuki

    2015-01-01

    Intrinsic luminescence properties of undoped CsCaCl 3 and CsSrCl 3 crystalline scintillators were studied. The crystal samples were grown by a vertical Bridgman method. Photoluminescence spectra of the crystals showed Auger-free luminescence (AFL) at 310 nm and self-trapped emission (STE) at 400 nm for CsCaCl 3 and 465 nm for CsSrCl 3 , when vacuum ultraviolet (VUV) light at 84 nm and 160 nm excited the crystals. X-ray excited radioluminescence spectra of the crystals showed some emission bands in the 280-600 nm wavelength range, which are owing to AFL, STE, and other origins such as lattice defects and impurities. Scintillation light yield was 400-300 ph/MeV, and the principal scintillation decay time about 2.5 ns and 12 ns for CsCaCl 3 and 1.8 ns and 13 ns for CsSrCl 3 . (author)

  15. Highly Emissive Divalent-Ion-Doped Colloidal CsPb1–xMxBr3 Perovskite Nanocrystals through Cation Exchange

    Science.gov (United States)

    2017-01-01

    Colloidal CsPbX3 (X = Br, Cl, and I) perovskite nanocrystals (NCs) have emerged as promising phosphors and solar cell materials due to their remarkable optoelectronic properties. These properties can be tailored by not only controlling the size and shape of the NCs but also postsynthetic composition tuning through topotactic anion exchange. In contrast, property control by cation exchange is still underdeveloped for colloidal CsPbX3 NCs. Here, we present a method that allows partial cation exchange in colloidal CsPbBr3 NCs, whereby Pb2+ is exchanged for several isovalent cations, resulting in doped CsPb1–xMxBr3 NCs (M= Sn2+, Cd2+, and Zn2+; 0 50%), sharp absorption features, and narrow emission of the parent CsPbBr3 NCs. The blue-shift in the optical spectra is attributed to the lattice contraction that accompanies the Pb2+ for M2+ cation exchange and is observed to scale linearly with the lattice contraction. This work opens up new possibilities to engineer the properties of halide perovskite NCs, which to date are demonstrated to be the only known system where cation and anion exchange reactions can be sequentially combined while preserving the original NC shape, resulting in compositionally diverse perovskite NCs. PMID:28260380

  16. Fast CsI-phoswich detector

    International Nuclear Information System (INIS)

    Langenbrunner, J.R.

    1996-01-01

    An improved phoswich radiation detector used pure CsI crystal and a fast plastic scintillator and a single photomultiplier tube. The plastic is arranged to receive incident radiation, and that which passed through then strikes the CsI crystal. Scintillation light from both the plastic and CsI crystal are applied to the photomultiplier tube, with the light from the plastic passing through the crystal without absorption therein. Electronics are provided for analyzing the output of the photomultiplier tube to discriminate responses due to the plastic and the CsI crystal, through short gate and long gate integration, to produce results which are indicative of the characteristics of the different types of incident radiation, even in the presence of large amounts of radiation. The phoswich detector has excellent timing resolution. The scintillators of the CsI- phoswich were chosen for their fast risetimes, of about 3 ns for NE102A, and 30 ns for the pure CsI. 5 figs

  17. Rapid determination of {sup 135}Cs and precise {sup 135}Cs/{sup 137}Cs atomic ratio in environmental samples by single-column chromatography coupled to triple-quadrupole inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Guosheng [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan); Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing 100049 (China); Tazoe, Hirofumi [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan); Yamada, Masatoshi, E-mail: myamada@hirosaki-u.ac.jp [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan)

    2016-02-18

    For source identification, measurement of {sup 135}Cs/{sup 137}Cs atomic ratio not only provides information apart from the detection of {sup 134}Cs and {sup 137}Cs, but it can also overcome the application limit that measurement of the {sup 134}Cs/{sup 137}Cs ratio has due to the short half-life of {sup 134}Cs (2.06 y). With the recent advancement of ICP-MS, it is necessary to improve the corresponding separation method for rapid and precise {sup 135}Cs/{sup 137}Cs atomic ratio analysis. A novel separation and purification technique was developed for the new generation of triple-quadrupole inductively coupled plasma-mass spectrometry (ICP-MS/MS). The simple chemical separation, incorporating ammonium molybdophosphate selective adsorption of Cs and subsequent single cation-exchange chromatography, removes the majority of isobaric and polyatomic interference elements. Subsequently, the ICP-MS/MS removes residual interference elements and eliminates the peak tailing effect of stable {sup 133}Cs, at m/z 134, 135, and 137. The developed analytical method was successfully applied to measure {sup 135}Cs/{sup 137}Cs atomic ratios and {sup 135}Cs activities in environmental samples (soil and sediment) for radiocesium source identification. - Highlights: • A simple {sup 135}Cs/{sup 137}Cs analytical method was developed. • The separation procedure was based on AMP adsorption and one column chromatography. • {sup 135}Cs/{sup 137}Cs was measured by ICP-MS/MS. • Decontamination factors for Ba, Mo, Sb, and Sn were improved. • {sup 135}Cs/{sup 137}Cs atomic ratios of 0.341–0.351 were found in Japanese soil samples.

  18. A novel vanadosilicate with hexadeca-coordinated Cs{sup +} ions as a highly effective Cs{sup +} remover

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Shuvo Jit; Moon, Won Kyung; Choi, Do Young; Hwang, In Chul; Yoon, Kyung Byung [Sogang Univ., Seoul (Korea, Republic of). Korea Center for Artificial Photosynthesis

    2014-07-07

    The effective removal of {sup 137}Cs{sup +} ions from contaminated groundwater and seawater and from radioactive nuclear waste solutions is crucial for public health and for the continuous operation of nuclear power plants. Various {sup 137}Cs{sup +} removers have been developed, but more effective {sup 137}Cs{sup +} removers are still needed. A novel microporous vanadosilicate with mixed-valence vanadium (V{sup 4+} and V{sup 5+}) ions is now reported, which shows an excellent ability for Cs{sup +} capture and immobilization from groundwater, seawater, and nuclear waste solutions. This material is superior to other known materials in terms of selectivity, capacity, and kinetics, and at very low Cs{sup +} concentrations, it was found to be the most effective material for the removal of radioactive Cs{sup +} ions under the test conditions. This novel vanadosilicate also contains hexadeca-coordinated Cs{sup +} ions, which corresponds to the highest coordination number ever described.

  19. Global EiBI-monopole

    Directory of Open Access Journals (Sweden)

    JIN Xinghua

    2014-04-01

    Full Text Available A global EiBI-monopole problem is studied under EiBI gravitational theory.The equations of global EiBI-monopole are derived in the curved spacetime and the relation between the spacetime metric and auxiliary metric is found.In the case of a very small parameter,an asymptotic form of equations is given.The series solutions of global EiBI-monopole at infinity are found.

  20. Hematopoietic stem cell capture and directional differentiation into vascular endothelial cells for metal stent-coated chitosan/hyaluronic acid loading CD133 antibody.

    Science.gov (United States)

    Zhang, Shixuan; Zhang, Fan; Feng, Bo; Fan, Qingyu; Yang, Feng; Shang, Debin; Sui, Jinghan; Zhao, Hong

    2015-03-01

    A series of metal stents coated with chitosan/hyaluronic acid (CS/HA) loading antibodies by electrostatic self-assembled method were prepared, and the types of cells captured by antibodies and their differentiation in vascular endothelial cells (ECs) evaluated by molecular biology and scanning electron microscope. The results showed that CD133 stent can selectively capture hematopoietic stem cells (HSC),which directionally differentiate into vascular ECs in peripheral blood by (CS/HA) induction, and simultaneously inhibit migration and proliferation of immune cells and vascular smooth muscle cells (MCs). CD34 stent can capture HSC, hematopoietic progenitor cells that differentiate into vascular ECs and immune cells, promoting smooth MCs growth, leading to thrombosis, inflammation, and rejection. CD133 stent can be implanted into miniature pig heart coronary and can repair vascular damage by capturing own HSC, thus contributing to the rapid natural vascular repair, avoiding inflammation and rejection, thrombosis and restenosis. These studies demonstrated that CD133 stent of HSC capture will be an ideal coated metal stent providing a new therapeutic approach for cardiovascular and cerebrovascular disease.

  1. The behavior of radioactive 137Cs and stable Cs at the isolated undisturbed mountain pond in Fukui, Japan

    International Nuclear Information System (INIS)

    Iwamoto, Kazumi; Kimura, Makio; Ando, Kenji; Amano, Hikaru

    2003-01-01

    The behavior of radioactive 137 Cs and stable Cs at the isolated undisturbed mountain pond in Fukui, Japan was studied for the pond water, the sedimentary grains and the soil near the pond. The concentrations of 137 Cs and stable Cs in the pond water ranged from 0.23 to 0.85 Bq/m 3 and from 0.005 to 0.018 mg/m 3 , respectively. The sedimentary grains were sorted by sieving into fractions with diameter from 2 mm to less than 38 μm. The concentrations of 137 Cs and stable Cs in the sorted grains were measured, and those of the adsorbed state were determined by subtracting the concentration of the grain matrix. The adsorbed concentrations increased with decrease in particle diameter and depended less on the kind of samples. The in-situ distribution coefficient Kd depended largely on particle diameter and increased with the decrease in diameter. The values of Kd ranged from about 20 to 1200 m 3 /kg for stable Cs and about 15 to 1000 m 3 /kg for 137 Cs, and the Kd of 137 Cs seemed to be slightly smaller than that of stable Cs. The concentration of stable Cs in the sedimentary mud was found to be close to that of the fine grains. The concentrations of stable Cs in the soil near the pond was about 7.7 mg/kg, and that of 137 Cs was about 0.6 kBq/kg for the surface layer soil and decreased with increase in soil depth. (author)

  2. The Godparent Plan: A Pedagogical Strategy for CS1 Accompaniment and CS2 Pedagogical Enhancement

    Directory of Open Access Journals (Sweden)

    Pedro Guillermo Feijóo-García

    2018-02-01

    Full Text Available Courses such as CS1 and CS2 can present an interesting pedagogical challenge when it comes to the theory-practice relationship, along with aspects that involve the course's logistics, the programming language used, and the characteristics of the students involved in the process. This study presents an innovative didactic approach, oriented towards the accompaniment of CS1 students by CS2 students at Universidad El Bosque, Colombia, seeking with this Godparent Plan, to provide a personalized accompaniment to first semester students, whereby CS2 students enhance their domain over concepts and skills while accompanying, explaining and teaching younger peers. The results of this study are favorable, outlining a didactic scheme that can be adapted and replicated in other curricular scenarios.

  3. Preparation and Characterization of TiO2/CdS Layers as Potential Photoelectrocatalytic Materials

    Directory of Open Access Journals (Sweden)

    Teofil-Danut Silipas

    2011-01-01

    Full Text Available The TiO2/CdS semiconductor composites were prepared on
    indium tin oxide (ITO substrates in di®erent mass proportions via wet-chemical techniques using bi-distilled water, acetyl-acetone, poly-propylene-glycol and Triton X-100 as additives. The composite layers were annealed in normal conditions at the temperature of 450±C, 120 min. with a rate of temperature increasing of 5±C/min. The structural and optical properties of all the TiO2/CdS ayers were characterized by X-ray di®raction, UV-VIS spectroscopy, spectrofluorimetry and FT/IR microscopy. The microstructural properties of the deposited TiO2/CdS layers can be modi¯ed by varying the mass proportions of TiO2:CdS. The good crystallinity level and the high optical adsorption of
    the TiO2/CdS layers make them attractive for photoelectrochemical cell applications.

  4. Correlations between potassium, rubidium and cesium (133Cs and 137Cs) in sporocarps of Suillus variegatus in a Swedish boreal forest

    International Nuclear Information System (INIS)

    Vinichuk, M.; Rosen, K.; Johanson, K.J.; Dahlberg, A.

    2011-01-01

    An analysis of sporocarps of ectomycorrhizal fungi Suillus variegatus assessed whether cesium ( 133 Cs and 137 Cs) uptake was correlated with potassium (K) or rubidium (Rb) uptake. The question was whether intraspecific correlations of Rb, K and 133 Cs mass concentrations with 137 Cs activity concentrations in sporocarps were higher within, rather than among, different fungal species, and if genotypic origin of sporocarps within a population affected uptake and correlation. Sporocarps (n = 51) from a Swedish forest population affected by the fallout after the Chernobyl accident were studied. The concentrations were 31.9 ± 6.79 g kg -1 for K (mean ± SD, dwt), 0.40 ± 0.09 g kg -1 for Rb, 8.7 ± 4.36 mg kg -1 for 133 Cs and 63.7 ± 24.2 kBq kg -1 for 137 Cs. The mass concentrations of 133 Cs correlated with 137 Cs activity concentrations (r = 0.61). There was correlation between both 133 Cs concentrations (r = 0.75) and 137 Cs activity concentrations (r = 0.44) and Rb, but the 137 Cs/ 133 Cs isotopic ratio negatively correlated with Rb concentration. Concentrations of K and Rb were weakly correlated (r = 0.51). The 133 Cs mass concentrations, 137 Cs activity concentrations and 137 Cs/ 133 Cs isotopic ratios did not correlate with K concentrations. No differences between, within or, among genotypes in S. variegatus were found. This suggested the relationships between K, Rb, 133 Cs and 137 Cs in sporocarps of S. variegatus is similar to other fungal species. - Highlights: → We studied uptake of Cs ( 133 Cs and 137 Cs), K and Rb by Suillus variegates sporocarps. → Genotypic origin of fungus did not affect uptake of studied elements (isotopes). → Genotypic origin did not affect correlation between Cs ( 133 Cs and 137 Cs), K and Rb.

  5. Polarization effect of CdZnTe imaging detector based on high energy γ source

    International Nuclear Information System (INIS)

    Li Miao; Xiao Shali; Wang Xi; Shen Min; Zhang Liuqiang; Cao Yulin; Chen Yuxiao

    2011-01-01

    The inner electric potential distribution of CdZnTe detector was derived by applying poisson equation with the first type boundary condition, and the polarization effect of CdZnTe pixellated detector for imaging 137 Cs γ source was investigated. The results of numerical calculation and experiment indicate that electric potential distribution is mainly influenced by applied bias for low charge density in CdZnTe crystal and, in turn, there is linear relationship between electric potential distribution and applied bias that induces uniform electric field under low irradiated flux. However, the electric potential appears polarization phenomenon, and the electric field in CdZnTe crystal is distorted when CdZnTe detector is under high irradiated flux. Consequently, charge carriers in CdZnTe crystal drift towards the edge pixels of irradiated region, and hence, the shut-off central pixels are surrounded by a ring of low counting pixels. The polarization effect indeed deteriorates the performance of CdZnTe detector severely and the event counts of edge pixels for irradiated region reduce about 70%. (authors)

  6. High photocatalytic performance of BiOI/Bi{sub 2}WO{sub 6} toward toluene and Reactive Brilliant Red

    Energy Technology Data Exchange (ETDEWEB)

    Li Huiquan [School of Chemistry and Chemical Engineering, Fuyang Normal College, Fuyang 236041 (China); Key Laboratory of Mesoscopic Chemistry of MOE, Jiangsu Provincial Key Laboratory of Nanotechnology, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Cui Yumin, E-mail: cuiyumin0908@163.com [School of Chemistry and Chemical Engineering, Fuyang Normal College, Fuyang 236041 (China); Hong Wenshan [School of Chemistry and Chemical Engineering, Fuyang Normal College, Fuyang 236041 (China)

    2013-01-01

    Graphical abstract: When BiOI/Bi{sub 2}WO{sub 6} catalyst was exposed to UV or visible light, the electrons in the valence band of Bi{sub 2}WO{sub 6} would be excited into the conduction band and then injected into the more positive conduction band of BiOI. Therefore, the photoelectrons were generated from Bi{sub 2}WO{sub 6} and transferred across the interface between BiOI and Bi{sub 2}WO{sub 6} to the surface of BiOI, leaving the photogenerated holes in the valence band of Bi{sub 2}WO{sub 6}. In this way, the photoinduced electron-hole pairs were effectively separated. Highlights: Black-Right-Pointing-Pointer BiOI sensitized Bi{sub 2}WO{sub 6} catalysts were successfully prepared by a facile method. Black-Right-Pointing-Pointer The 13.2% BiOI/Bi{sub 2}WO{sub 6} catalyst exhibits higher photoactivities than P25. Black-Right-Pointing-Pointer A possible transfer process of photogenerated carriers was proposed. - Abstract: BiOI sensitized nano-Bi{sub 2}WO{sub 6} photocatalysts with different BiOI contents were successfully synthesized by a facile deposition method at room temperature, and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) high-resolution transmission electron microscopy (HR-TEM), photoluminescence (PL) spectra, UV-vis diffuse reflection spectroscopy (UV-vis DRS) and Brunauer-Emmett-Teller (BET) surface area measurements. The photocatalytic activity of BiOI/Bi{sub 2}WO{sub 6} was evaluated by the photo-degradation of Reactive Brilliant Red (X-3B) in suspended solution and toluene in gas phase. It has been shown that the BiOI/Bi{sub 2}WO{sub 6} catalysts exhibit a coexistence of both tetragonal BiOI and orthorhombic Bi{sub 2}WO{sub 6} phases. With increasing BiOI content, the absorption intensity of BiOI/Bi{sub 2}WO{sub 6} catalysts increases in the 380-600 nm region and the absorption edge shifts significantly to longer wavelengths as compared to pure Bi{sub 2}WO{sub 6}. The 13.2% BiOI/Bi{sub 2}WO{sub 6} catalyst exhibits

  7. MLED_BI: a new BI Design Approach to Support Multilingualism in Business Intelligence

    Directory of Open Access Journals (Sweden)

    Nedim Dedić

    2017-11-01

    Full Text Available Existing approaches to support Multilingualism (ML in Business Intelligence (BI create problems for business users, present a number of challenges from the technical perspective, and lead to issues with logical dependence in the star schema. In this paper, we propose MLED_BI (Multilingual Enabled Design for Business Intelligence, a novel BI design approach to support the application of ML in BI Environment, which overcomes the issues and problems found with existing approaches. The approach is based on a revision of the data warehouse dimensional modelling approach and treats the Star Schema as a higher level entity. This paper describes MLED_BI and the validation and evaluation approach used.

  8. Ga-Bi-Te system

    International Nuclear Information System (INIS)

    Rustamov, P.G.; Seidova, N.A.; Shakhbazov, M.G.; AN Azerbajdzhanskoj SSR, Baku. Inst. Neorganicheskoj i Fizicheskoj Khimii)

    1976-01-01

    To elucidate the nature of interaction in the system Ga-Bi-Te, a study has been made of sections GaTe-Bi 2 Te 3 , Ga 2 Te 3 -Bi, GaTe-Bi and Bi 2 Te 3 -Ga. The alloys have been prepared by direct melting of the components or their alloys with subsequent homogenizin.o annealing at 400 deg C. The study has been made by the methods of differential thermal, microstructural analysis and by microhardness measurements. On the basis of literature data and data obtained a projection of the liquidus surface of the phase diagram for the system Ga-Bi-Te has been constructed. In the ternary system there are 17 curves of monovariant equilibrium dividing the liquidus into 10 fields of primary crystallization of phases, 9 points of non-variant equilibrium of which 4 points are triple eutectics and 5 points are triple peritectics

  9. Cs/CsPbX3 (X = Br, Cl) epitaxial heteronanocrystals with magic-angle stable/metastable grain boundary

    Science.gov (United States)

    Zhang, Yumeng; Fan, Baolu; Wu, Wenhui; Fan, Jiyang

    2017-05-01

    Metal-semiconductor heteronanostructures are crucial building blocks of nanoscale electronic and optoelectronic devices. However, the lattice misfit remains a challenge in constructing heteronanostructures. Perovskite nanocrystals are superior candidates for constructing nanodevices owing to excellent optical, ferroelectric, and superconducting properties. We report the epitaxial growth of lattice-matched Cs/CsPbBr3 metal-semiconductor heteronanocrystals in a liquid medium. The well-crystallized ultrathin Cs layers grow epitaxially on the surfaces of colloidal CsPbBr3 nanocrystals, forming heteronanocrystals with interface diameters of several nanometers. Most of them are pseudomorphic with coherent interfaces free from dislocations, and the others exhibit discrete high-angle grain boundaries. The model based on the calculation of the elastic potential energy of the epilayer and analysis of the near-coincidence sites explains well the experimental result. The analysis shows that the excellent lattice match between the metal and the semiconductor ensures the ideal epitaxial-growth of both Cs/CsPbBr3 and Cs/CsPbCl3 heteronanocrystals. Such metal/semiconductor heteronanocrystals pave the way for developing perovskite-based nanodevices.

  10. Phase Transitions in CsSnCl3 and CsPbBr3 An NMR and NQR Study

    Science.gov (United States)

    Sharma, Surendra; Weiden, Norbert; Weiss, Alarich

    1991-04-01

    The phase transitions in CsSnCl3 and CsPbBr3 have been studied by X-ray powder diffraction, by 81Br-NQR and by 'H-, 119Sn-, and 113Cs-NMR. At room temperature in air CsSnCl3 forms a hydrate which can be dehydrated to the monoclinic phase II of CsSnCl3. The high temperature phase I has the Perovskite structure, as the X-ray and NMR experiments show. The three phases of CsPbBr3, known from literature, have been corroborated. The results are discussed in the framework of the group ABX3, A = alkalimetal ion, B = IV main group ion, and X = Halogen ion

  11. VERA-CS Verification & Validation Plan

    Energy Technology Data Exchange (ETDEWEB)

    Downar, Thomas [Univ. of Michigan, Ann Arbor, MI (United States)

    2017-02-01

    This report summarizes the current status of VERA-CS Verification and Validation for PWR Core Follow operation and proposes a multi-phase plan for continuing VERA-CS V&V in FY17 and FY18. The proposed plan recognizes the hierarchical nature of a multi-physics code system such as VERA-CS and the importance of first achieving an acceptable level of V&V on each of the single physics codes before focusing on the V&V of the coupled physics solution. The report summarizes the V&V of each of the single physics codes systems currently used for core follow analysis (ie MPACT, CTF, Multigroup Cross Section Generation, and BISON / Fuel Temperature Tables) and proposes specific actions to achieve a uniformly acceptable level of V&V in FY17. The report also recognizes the ongoing development of other codes important for PWR Core Follow (e.g. TIAMAT, MAMBA3D) and proposes Phase II (FY18) VERA-CS V&V activities in which those codes will also reach an acceptable level of V&V. The report then summarizes the current status of VERA-CS multi-physics V&V for PWR Core Follow and the ongoing PWR Core Follow V&V activities for FY17. An automated procedure and output data format is proposed for standardizing the output for core follow calculations and automatically generating tables and figures for the VERA-CS Latex file. A set of acceptance metrics is also proposed for the evaluation and assessment of core follow results that would be used within the script to automatically flag any results which require further analysis or more detailed explanation prior to being added to the VERA-CS validation base. After the Automation Scripts have been completed and tested using BEAVRS, the VERA-CS plan proposes the Watts Bar cycle depletion cases should be performed with the new cross section library and be included in the first draft of the new VERA-CS manual for release at the end of PoR15. Also, within the constraints imposed by the proprietary nature of plant data, as many as possible of the FY17

  12. Epiphytic fruticose lichens as biomonitors for retrospective evaluation of the 134Cs/137Cs ratio in Fukushima fallout

    International Nuclear Information System (INIS)

    Ramzaev, V.; Barkovsky, A.; Gromov, A.; Ivanov, S.; Kaduka, M.

    2014-01-01

    In 2011–2013, sampling of epiphytic fruticose lichens of the genera Usnea, Bryoria and Alectoria was carried out on Sakhalin and Kuril Islands (the Sakhalin region, Russia) to investigate contamination of these organisms with the Fukushima-derived 134 Cs and 137 Cs. Activities of the radionuclides were determined in all 56 samples of lichens taken for the analysis. After correction for radioactive decay (on 15 March 2011), the activity concentrations ranged from 2.1 Bq kg −1 (d.w.) to 52 Bq kg −1 for 134 Cs and from 2.3 Bq kg −1 to 52 Bq kg −1 for 137 Cs. Cesium-134 and 137 Cs activities for the whole set of lichens (n = 56) were strongly positively correlated; Spearman's rank correlation coefficient was calculated as 0.991 (P < 0.01). The activity concentrations of 134 Cs and 137 Cs in Usnea lichens from the Sakhalin and Kunashir islands declined with a factor of three in the period from 2011 to 2013. The average biological half-time for both cesium radionuclides in lichens of the genus Usnea is estimated as 1.3 y. The mean of 0.99 ± 0.10 and median of 0.99 were calculated for the decay corrected 134 Cs/ 137 Cs activities ratios in the lichens (n = 56). The radionuclides ratio in the lichens did not depend on location of sampling site, species and the time that had passed after the Fukushima accident. The regression analysis has shown the background pre-Fukushima level of 137 Cs of 0.4 ± 0.3 Bq kg −1 , whereas the ratio between the Fukushima-borne 134 Cs and 137 Cs in the lichens was estimated as 1.04. The 134 Cs/ 137 Cs activities ratio in lichens from the Sakhalin region is consistent with the ratios reported by others for the heavy contaminated areas on Honshu Island in Japan following the Fukushima accident. The activity concentrations of natural 7 Be in lichens from the Sakhalin region varied between 100 Bq kg −1 and 600 Bq kg −1 ; the activity concentrations did not exhibit temporal variations during a 2y-period of observations. The

  13. Specific accumulation of 20 trace elements in great cormorants (Phalacrocorax carbo) from Japan

    International Nuclear Information System (INIS)

    Nam, Dong-Ha; Anan, Yasumi; Ikemoto, Tokutaka; Okabe, Yuko; Kim, Eun-Young; Subramanian, Annamalai; Saeki, Kazutoshi; Tanabe, Shinsuke

    2005-01-01

    This study is to elucidate the specific accumulation of 20 trace elements in tissues/organs of great cormorants from two different colonies (Lake Biwa and Mie) in Japan. In the body distribution of trace elements, some elements revealed tissue-specific accumulation such as most of the burden of Mo, Ag and Cd in liver, Tl and Cd in kidney, Cu, Rb and Cs in muscle, and V, Sr and Ba in bone. Gender-related variation was not observed in both populations for most of the trace elements, except for higher hepatic Sr in males from Lake Biwa. Hepatic V, muscular Hg and Tl, and Cd in liver, kidney and muscle increased with growth. Comparison of trace element levels in tissues between the two colonies showed that Cr, Rb, Sr, Cd, Cs, Ba and Tl levels were higher in Lake Biwa than in Mie, whereas Zn, Co and Hg in Mie samples were greater than Lake Biwa. Variations of elemental levels in stomach contents also showed similar patterns, thus, showing that dietary sources tended to be the main factor for these regional variations. Toxic Hg and Cd concentrations in the liver of cormorants from the two colonies were lower than those from other areas, implying relatively low exposure to these metals in the present study sites. Concentrations of V, Co, Ag, Cd, Cs, Hg, Tl, Pb and Bi in liver remained more or less at the same level between 1993 and 2003, while hepatic Cr, Mn, Cu, Zn, Se, Rb, Sr and Ba showed apparent decrease, which might be related to the biological factors. - Dietary sources seemed to be the main reason for variable results

  14. All-Ambient Processed Binary CsPbBr3-CsPb2Br5 Perovskites with Synergistic Enhancement for High-Efficiency Cs-Pb-Br-Based Solar Cells.

    Science.gov (United States)

    Zhang, Xisheng; Jin, Zhiwen; Zhang, Jingru; Bai, Dongliang; Bian, Hui; Wang, Kang; Sun, Jie; Wang, Qian; Liu, Shengzhong Frank

    2018-02-28

    All-inorganic CsPbBr 3 perovskite solar cells display outstanding stability toward moisture, light soaking, and thermal stressing, demonstrating great potential in tandem solar cells and toward commercialization. Unfortunately, it is still challenging to prepare high-performance CsPbBr 3 films at moderate temperatures. Herein, a uniform, compact CsPbBr 3 film was fabricated using its quantum dot (QD)-based ink precursor. The film was then treated using thiocyanate ethyl acetate (EA) solution in all-ambient conditions to produce a superior CsPbBr 3 -CsPb 2 Br 5 composite film with a larger grain size and minimal defects. The achievement was attributed to the surface dissolution and recrystallization of the existing SCN - and EA. More specifically, the SCN - ions were first absorbed on the Pb atoms, leading to the dissolution and stripping of Cs + and Br - ions from the CsPbBr 3 QDs. On the other hand, the EA solution enhances the diffusion dynamics of surface atoms and the surfactant species. It is found that a small amount of CsPb 2 Br 5 in the composite film gives the best surface passivation, while the Br-rich surface decreases Br vacancies (V Br ) for a prolonged carrier lifetime. As a result, the fabricated device gives a higher solar cell efficiency of 6.81% with an outstanding long-term stability.

  15. The distribution of 137Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

    International Nuclear Information System (INIS)

    Vinichuk, M.; Johanson, K.J.; Rydin, H.; Rosen, K.

    2010-01-01

    We record the distribution of 137 Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as 137 Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris 137 Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher 137 Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of 137 Cs within the plants. The patterns of 137 Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The 137 Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between 137 Cs and Rb (r = 0.89), and between 137 Cs and stable Cs (r = 0.84). This suggests similarities between 137 Cs and Rb in uptake and relocation within the Sphagnum, but that 137 Cs differs from K.

  16. The distribution of (137)Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden.

    Science.gov (United States)

    Vinichuk, M; Johanson, K J; Rydin, H; Rosén, K

    2010-02-01

    We record the distribution of (137)Cs, K, Rb and Cs within individual Sphagnum plants (down to 20cm depth) as well as (137)Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris(137)Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher (137)Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of (137)Cs within the plants. The patterns of (137)Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The (137)Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10cm) of the plant (r=0.50). The strongest correlations were revealed between (137)Cs and Rb (r=0.89), and between (137)Cs and stable Cs (r=0.84). This suggests similarities between (137)Cs and Rb in uptake and relocation within the Sphagnum, but that (137)Cs differs from K. Copyright 2009 Elsevier Ltd. All rights reserved.

  17. Electronic structures and stability of Ni/Bi2Te3 and Co/Bi2Te3 interfaces

    International Nuclear Information System (INIS)

    Xiong Ka; Wang Weichao; Alshareef, Husam N; Gupta, Rahul P; Gnade, Bruce E; Cho, Kyeongjae; White, John B

    2010-01-01

    We investigate the electronic structures and stability for Ni/Bi 2 Te 3 , NiTe/Bi 2 Te 3 , Co/Bi 2 Te 3 and CoTe 2 /Bi 2 Te 3 interfaces by first-principles calculations. It is found that the surface termination strongly affects the band alignment. Ni and Co are found to form Ohmic contacts to Bi 2 Te 3 . The interface formation energy for Co/Bi 2 Te 3 interfaces is much lower than that of Ni/Bi 2 Te 3 interfaces. Furthermore, we found that NiTe on Bi 2 Te 3 is more stable than Ni, while the formation energies for Co and CoTe 2 on Bi 2 Te 3 are comparable.

  18. Interfacial Energy-Level Alignment for High-Performance All-Inorganic Perovskite CsPbBr3 Quantum Dot-Based Inverted Light-Emitting Diodes.

    Science.gov (United States)

    Subramanian, Alagesan; Pan, Zhenghui; Zhang, Zhenbo; Ahmad, Imtiaz; Chen, Jing; Liu, Meinan; Cheng, Shuang; Xu, Yijun; Wu, Jun; Lei, Wei; Khan, Qasim; Zhang, Yuegang

    2018-04-18

    All-inorganic perovskite light-emitting diode (PeLED) has a high stability in ambient atmosphere, but it is a big challenge to achieve high performance of the device. Basically, device design, control of energy-level alignment, and reducing the energy barrier between adjacent layers in the architecture of PeLED are important factors to achieve high efficiency. In this study, we report a CsPbBr 3 -based PeLED with an inverted architecture using lithium-doped TiO 2 nanoparticles as the electron transport layer (ETL). The optimal lithium doping balances the charge carrier injection between the hole transport layer and ETL, leading to superior device performance. The device exhibits a current efficiency of 3 cd A -1 , a luminance efficiency of 2210 cd m -2 , and a low turn-on voltage of 2.3 V. The turn-on voltage is one of the lowest values among reported CsPbBr 3 -based PeLEDs. A 7-fold increase in device efficiencies has been obtained for lithium-doped TiO 2 compared to that for undoped TiO 2 -based devices.

  19. Uptake and accumulation of 137Cs by upland grassland soil fungi: a potential pool of Cs immobilization

    International Nuclear Information System (INIS)

    Dighton, J.; Clint, G.M.; Poskitt, J.

    1991-01-01

    Reports of high concentrations of fallout radiocaesium in basidiomycete fruit bodies after the Chernobyl nuclear reactor accident and speculation that fungi could be long-term 137 Cs accumulators led us to ask if fungi could be long-term 137 Cs accumulators. We used six common upland grassland species to try to estimate their importance in the immobilization of 137 Cs. Uptake of Cs by these species ranged from 44 to 235 nmol Cs g − 1d.w. h − 1. Efflux studies indicate that more than 40% of the Cs taken up is bound within the hyphae. We estimate that the fungal component of the soil could immobilize the total radiocaesium fallout received in upland grasslands following the Chernobyl accident

  20. Requirement of transmembrane domain for CD154 association to lipid rafts and subsequent biological events.

    Directory of Open Access Journals (Sweden)

    Nadir Benslimane

    Full Text Available Interaction of CD40 with CD154 leads to recruitment of both molecules into lipid rafts, resulting in bi-directional cell activation. The precise mechanism by which CD154 is translocated into lipid rafts and its impact on CD154 signaling remain largely unknown. Our aim is to identify the domain of CD154 facilitating its association to lipid rafts and the impact of such association on signaling events and cytokine production. Thus, we generated Jurkat cell lines expressing truncated CD154 lacking the cytoplasmic domain or chimeric CD154 in which the transmembrane domain was replaced by that of transferrin receptor I, known to be excluded from lipid rafts. Our results show that cell stimulation with soluble CD40 leads to the association of CD154 wild-type and CD154-truncated, but not CD154-chimera, with lipid rafts. This is correlated with failure of CD154-chimera to activate Akt and p38 MAP kinases, known effectors of CD154 signaling. We also found that CD154-chimera lost the ability to promote IL-2 production upon T cell stimulation with anti-CD3/CD28 and soluble CD40. These results demonstrate the implication of the transmembrane domain of CD154 in lipid raft association, and that this association is necessary for CD154-mediated Akt and p38 activation with consequent enhancement of IL-2 production.

  1. Photoresponse of CsPbBr3 and Cs4PbBr6 Perovskite Single Crystals.

    Science.gov (United States)

    Cha, Ji-Hyun; Han, Jae Hoon; Yin, Wenping; Park, Cheolwoo; Park, Yongmin; Ahn, Tae Kyu; Cho, Jeong Ho; Jung, Duk-Young

    2017-02-02

    High-quality and millimeter-sized perovskite single crystals of CsPbBr 3 and Cs 4 PbBr 6 were prepared in organic solvents and studied for correlation between photocurrent generation and photoluminescence (PL) emission. The CsPbBr 3 crystals, which have a 3D perovskite structure, showed a highly sensitive photoresponse and poor PL signal. In contrast, Cs 4 PbBr 6 crystals, which have a 0D perovskite structure, exhibited more than 1 order of magnitude higher PL intensity than CsPbBr 3 , which generated an ultralow photoresponse under illumination. Their contrasting optoelectrical characteristics were attributed to different exciton binding energies, induced by coordination geometry of the [PbBr 6 ] 4- octahedron sublattices. This work correlated the local structures of lead in the primitive perovskite and its derivatives to PL spectra as well as photoconductivity.

  2. Electronic structures and stability of Ni/Bi2Te3 and Co/Bi2Te3 interfaces

    KAUST Repository

    Xiong, Ka; Wang, Weichao; Alshareef, Husam N.; Gupta, Rahul P.; White, John B.; Gnade, Bruce E.; Cho, Kyeongjae

    2010-01-01

    We investigate the electronic structures and stability for Ni/Bi 2Te3, NiTe/Bi2Te3, Co/Bi 2Te3 and CoTe2/Bi2Te3 interfaces by first-principles calculations. It is found that the surface termination strongly affects the band alignment. Ni and Co are found to form Ohmic contacts to Bi2Te3. The interface formation energy for Co/Bi2Te3 interfaces is much lower than that of Ni/Bi2Te3 interfaces. Furthermore, we found that NiTe on Bi2Te3 is more stable than Ni, while the formation energies for Co and CoTe2 on Bi2Te3 are comparable. © 2010 IOP Publishing Ltd.

  3. Electronic structures and stability of Ni/Bi2Te3 and Co/Bi2Te3 interfaces

    KAUST Repository

    Xiong, Ka

    2010-03-04

    We investigate the electronic structures and stability for Ni/Bi 2Te3, NiTe/Bi2Te3, Co/Bi 2Te3 and CoTe2/Bi2Te3 interfaces by first-principles calculations. It is found that the surface termination strongly affects the band alignment. Ni and Co are found to form Ohmic contacts to Bi2Te3. The interface formation energy for Co/Bi2Te3 interfaces is much lower than that of Ni/Bi2Te3 interfaces. Furthermore, we found that NiTe on Bi2Te3 is more stable than Ni, while the formation energies for Co and CoTe2 on Bi2Te3 are comparable. © 2010 IOP Publishing Ltd.

  4. Bismuth-boron multiple bonding in BiB{sub 2}O{sup -} and Bi{sub 2}B{sup -}

    Energy Technology Data Exchange (ETDEWEB)

    Jian, Tian; Cheung, Ling Fung; Chen, Teng-Teng; Wang, Lai-Sheng [Department of Chemistry, Brown University, Providence, RI (United States)

    2017-08-01

    Despite its electron deficiency, boron is versatile in forming multiple bonds. Transition-metal-boron double bonding is known, but boron-metal triple bonds have been elusive. Two bismuth boron cluster anions, BiB{sub 2}O{sup -} and Bi{sub 2}B{sup -}, containing triple and double B-Bi bonds are presented. The BiB{sub 2}O{sup -} and Bi{sub 2}B{sup -} clusters are produced by laser vaporization of a mixed B/Bi target and characterized by photoelectron spectroscopy and ab initio calculations. Well-resolved photoelectron spectra are obtained and interpreted with the help of ab initio calculations, which show that both species are linear. Chemical bonding analyses reveal that Bi forms triple and double bonds with boron in BiB{sub 2}O{sup -} ([Bi≡B-B≡O]{sup -}) and Bi{sub 2}B{sup -} ([Bi=B=Bi]{sup -}), respectively. The Bi-B double and triple bond strengths are calculated to be 3.21 and 4.70 eV, respectively. This is the first experimental observation of Bi-B double and triple bonds, opening the door to design main-group metal-boron complexes with multiple bonding. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Microstructure Of MnBi/Bi Eutectic Alloy

    Science.gov (United States)

    Wilcox, William R.; Eisa, G. F.; Baskaran, B.; Richardson, Donald C.

    1988-01-01

    Collection of three reports describes studies of directional solidification of MnBi/Bi eutectic alloy. Two of the reports, "Influence of Convection on Lamellar Spacing of Eutectics" and "Influence of Convection on Eutectic Microstructure," establish theoretical foundation for remaining document. Reports seek to quantify effect of convection on concentration field of growing lamellar eutectic. Remaining report, "Study of Eutectic Formation," begins by continuing theoretical developments. New technique under development by one of the authors helps to reveal three-dimensional microstructures of alloys.

  6. Postsynthesis Transformation of Insulating Cs4PbBr6 Nanocrystals into Bright Perovskite CsPbBr3 through Physical and Chemical Extraction of CsBr.

    Science.gov (United States)

    Palazon, Francisco; Urso, Carmine; De Trizio, Luca; Akkerman, Quinten; Marras, Sergio; Locardi, Federico; Nelli, Ilaria; Ferretti, Maurizio; Prato, Mirko; Manna, Liberato

    2017-10-13

    Perovskite-related Cs 4 PbBr 6 nanocrystals present a "zero-dimensional" crystalline structure where adjacent [PbBr 6 ] 4- octahedra do not share any corners. We show in this work that these nanocrystals can be converted into "three-dimensional" CsPbBr 3 perovskites by extraction of CsBr. This conversion drastically changes the optoelectronic properties of the nanocrystals that become highly photoluminescent. The extraction of CsBr can be achieved either by thermal annealing (physical approach) or by chemical reaction with Prussian Blue (chemical approach). The former approach can be simply carried out on a dried film without addition of any chemicals but does not yield a full transformation. Instead, reaction with Prussian Blue in solution achieves a full transformation into the perovskite phase. This transformation was also verified on the iodide counterpart (Cs 4 PbI 6 ).

  7. Photocatalytic activity of Bi{sub 2}WO{sub 6}/Bi{sub 2}S{sub 3} heterojunctions: the facilitation of exposed facets of Bi{sub 2}WO{sub 6} substrate

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Long [School of Chemistry and Chemical Engineering, Yulin University, Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization, Yulin 71900 (China); School of Chemistry and Chemical Engineering, Yan’an University, Shaanxi Key Laboratory of Chemical Reaction Engineering, Yan’an 716000 (China); Wang, Yufei [School of Chemistry and Chemical Engineering, Yulin University, Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization, Yulin 71900 (China); Shen, Huidong; Zhang, Yu [School of Chemistry and Chemical Engineering, Yan’an University, Shaanxi Key Laboratory of Chemical Reaction Engineering, Yan’an 716000 (China); Li, Jian [School of Chemistry and Chemical Engineering, Yulin University, Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization, Yulin 71900 (China); Wang, Danjun, E-mail: yulyanlong@aliyun.com [School of Chemistry and Chemical Engineering, Yan’an University, Shaanxi Key Laboratory of Chemical Reaction Engineering, Yan’an 716000 (China)

    2017-01-30

    Highlights: • Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6} hybrids with exposed (020) Bi{sub 2}WO{sub 6} facets have been synthesized. • X-ray photoelectron spectroscopy reveals that a small amount of Bi{sub 2}S{sub 3} was formed. • The enhanced photoactivity of hybrids is due to heterojunction and (020) facets. • A possible photocatalytic degradation mechanism is proposed. - Abstract: Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6} hybrid architectures with exposed (020) Bi{sub 2}WO{sub 6} facets have been synthesized via a controlled anion exchange approach. X-ray photoelectron spectroscopy (XPS) reveals that a small amount of Bi{sub 2}S{sub 3} was formed on the surface of Bi{sub 2}WO{sub 6} during the anion exchange process, thus leading to the transformation from the Bi{sub 2}WO{sub 6} to Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6}. A rhodamine B (RhB) aqueous solution was chosen as model organic pollutants to evaluate the photocatalytic activities of the Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6} catalysts. Under visible light irradiation, the Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6}-TAA displayed the excellent visible light photoactivities compared with pure Bi{sub 2}S{sub 3}, Bi{sub 2}WO{sub 6} and other composite photocatalysts. The efficient photocatalytic activity of the Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6}-TAA composite microspheres was ascribed to the constructed heterojunctions and the inner electric field caused by the exposed (020) Bi{sub 2}WO{sub 6} facets. Active species trapping experiments revealed that h{sup +} and O{sub 2}·{sup −} are the main active species in the photocatalytic process. Furthermore, the as-obtained photocatalysts showed good photocatalytic activity after four recycles. The results presented in this study provide a new concept for the rational design and development of highly efficient photocatalysts.

  8. Optimization of excess Bi doping to enhance ferroic orders of spin casted BiFeO3 thin film

    International Nuclear Information System (INIS)

    Gupta, Surbhi; Gupta, Vinay; Tomar, Monika; James, A. R.; Pal, Madhuparna; Guo, Ruyan; Bhalla, Amar

    2014-01-01

    Multiferroic Bismuth Ferrite (BiFeO 3 ) thin films with varying excess bismuth (Bi) concentration were grown by chemical solution deposition technique. Room temperature multiferroic properties (ferromagnetism, ferroelectricity, and piezoelectricity) of the deposited BiFeO 3 thin films have been studied. High resolution X-ray diffraction and Raman spectroscopy studies reveal that the dominant phases formed in the prepared samples change continuously from a mixture of BiFeO 3 and Fe 2 O 3 to pure BiFeO 3 phase and, subsequently, to a mixture of BiFeO 3 and Bi 2 O 3 with increase in the concentration of excess Bi from 0% to 15%. BiFeO 3 thin films having low content (0% and 2%) of excess Bi showed the traces of ferromagnetic phase (γ-Fe 2 O 3 ). Deterioration in ferroic properties of BiFeO 3 thin films is also observed when prepared with higher content (15%) of excess Bi. Single-phased BiFeO 3 thin film prepared with 5% excess Bi concentration exhibited the soft ferromagnetic hysteresis loops and ferroelectric characteristics with remnant polarization 4.2 μC/cm 2 and saturation magnetization 11.66 emu/g. The switching of fine spontaneous domains with applied dc bias has been observed using piezoresponse force microscopy in BiFeO 3 thin films having 5% excess Bi. The results are important to identify optimum excess Bi concentration needed for the formation of single phase BiFeO 3 thin films exhibiting the improved multiferroic properties.

  9. Simultaneous determination of Cd(II) and Pb(II) by differential pulse anodic stripping voltammetry based on graphite nanofibers-Nafion composite modified bismuth film electrode.

    Science.gov (United States)

    Li, Dongyue; Jia, Jianbo; Wang, Jianguo

    2010-12-15

    A bismuth-film modified graphite nanofibers-Nafion glassy carbon electrode (BiF/GNFs-NA/GCE) was constructed for the simultaneous determination of trace Cd(II) and Pb(II). The electrochemical properties and applications of the modified electrode were studied. Operational parameters such as deposition potential, deposition time, and bismuth ion concentration were optimized for the purpose of determination of trace metal ions in 0.10 M acetate buffer solution (pH 4.5). Under optimal conditions, based on three times the standard deviation of the baseline, the limits of detection were 0.09 μg L(-1) for Cd(II) and 0.02 μg L(-1) for Pb(II) with a 10 min preconcentration. In addition, the BiF/GNFs-NA/GCE displayed good reproducibility and selectivity, making it suitable for the simultaneous determination of Cd(II) and Pb(II) in real sample such as river water and human blood samples. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. Elucidation and functional characterization of CsPSY and CsUGT promoters in Crocus sativus L.

    Science.gov (United States)

    Bhat, Archana; Mishra, Sonal; Kaul, Sanjana; Dhar, Manoj K

    2018-01-01

    The dried stigmas of Crocus sativus constitute the saffron, which is considered to be the costliest spice of the world. Saffron is valuable for its constituents, which are mainly apocarotenoids. In order to enhance the production of apocarotenoids, it is imperative to understand the regulation of apocarotenoid biosynthetic pathway. In C. sativus, although the pathway has been elucidated, the information regarding the regulation of the pathwaygenes is scanty. During the present investigation, the characterization of promoters regulating the expression of two important genes i.e. CsPSY and CsUGT was performed. We successfully cloned the promoters of both the genes, which were functionally characterized in Crocus sativus and Nicotiana tabaccum. In silico analysis of the promoters demonstrated the presence of several important cis regulatory elements responding tolight, hormonesand interaction with transcription factors (TFs). Further analysis suggested the regulation of CsPSY promoter by Abscisic acid (ABA) and that of CsUGT by Gibberellic acid (GA). In addition, we also observed ABA and GA mediated modulation in the expression of significant TFs and CsPSY and CsUGT transcripts. Overall, the study addresses issues related to regulation of key genes of apocarotenoid pathway in C.sativus.

  11. Transfer of Chernobyl-derived 134Cs, 137Cs, 131I and 103Ru from flowers to honey and pollen

    International Nuclear Information System (INIS)

    Bunzl, K.; Kracke, W.

    1988-01-01

    The activity concentrations of 137 Cs, 134 Cs, 131 I and 103 Ru were determined separately in honey and pollen samples collected from a single bee colony during several months after the deposition of Chernobyl fallout. The source of each honey and pollen sample was determined by pollen analysis. Although the activity concentrations in honey and pollen varied with time, the concentrations of 137 Cs and 134 Cs were, in general, higher in pollen than in honey. For 103 Ru and 131 I, these differences were comparatively small. The mean 131 I/ 137 Cs and 103 Ru/ 137 Cs ratios were about one order of magnitude higher in honey than in pollen. The mean 131 I/ 103 Ru ratio was about the same for honey and pollen. This observation, in the light of the corresponding nuclide ratios found in the deposition, suggests that 137 Cs, 134 Cs, 131 I and 103 Ru were taken up by the plant leaves and transported to nectar and pollen. The higher activity concentrations of 137 Cs and 134 Cs in pollen, relative to honey, indicate that these radionuclides behave analogously to potassium, which is also found in higher quantities in pollen. (author)

  12. Topotactic synthesis of a new BiS2-based superconductor Bi2(O,F)S2

    OpenAIRE

    Okada, Tomoyuki; Ogino, Hiraku; Shimoyama, Jun-ichi; Kishio, Kohji

    2015-01-01

    A new BiS2-based superconductor Bi2(O,F)S2 was discovered. This is a layered compound consisting of alternate stacking structure of rock-salt-type BiS2 superconducting layer and fluorite-type Bi(O,F) blocking layer. Bi2(O,F)S2 was obtained as the main phase by topotactic fluorination of undoped Bi2OS2 using XeF2, which is the first topotactic synthesis of an electron-doped superconductor via reductive fluorination. With increasing F-content, a- and c-axis length increased and decreased, respe...

  13. Relative injectivity and CS-modules

    Directory of Open Access Journals (Sweden)

    Mahmoud Ahmed Kamal

    1994-01-01

    Full Text Available In this paper we show that a direct decomposition of modules M⊕N, with N homologically independent to the injective hull of M, is a CS-module if and only if N is injective relative to M and both of M and N are CS-modules. As an application, we prove that a direct sum of a non-singular semisimple module and a quasi-continuous module with zero socle is quasi-continuous. This result is known for quasi-injective modules. But when we confine ourselves to CS-modules we need no conditions on their socles. Then we investigate direct sums of CS-modules which are pairwise relatively inective. We show that every finite direct sum of such modules is a CS-module. This result is known for quasi-continuous modules. For the case of infinite direct sums, one has to add an extra condition. Finally, we briefly discuss modules in which every two direct summands are relatively inective.

  14. One step synthesis of Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon spheres with enhanced photocatalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Lingling [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Luo, Zhijun, E-mail: lzj@ujs.edu.cn [School of the Environment, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093 (China); Tang, Chao [Maple Leaf International High School, Zhenjiang 212013 (China)

    2013-11-15

    Graphical abstract: Functional groups of sodium gluconate play synergetic roles in the formation of Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon core–shell nanosturctures (Bi@Bi{sub 2}O{sub 3}@CRCSs). Bi@Bi{sub 2}O{sub 3}@CRCSs exhibits significant enhanced photocatalytic activity under visible light irradiation. - Highlights: • One step synthesis of Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon spheres. • Functional groups of sodium gluconate play synergetic roles in the formation of Bi@Bi{sub 2}O{sub 3}@CRCSs. • Bi@Bi{sub 2}O{sub 3}@CRCSs exhibits enhanced photocatalytic activity under visible light irradiation. - Abstract: Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon core-shell nanosturctures (Bi@Bi{sub 2}O{sub 3}@CRCSs) have been synthesized via a one-step method. The core–shell nanosturctures of the as-prepared samples were confirmed by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and Raman spectroscopy. The formation of Bi@Bi{sub 2}O{sub 3}@CRCSs core–shell nanosturctures should attribute to the synergetic roles of different functional groups of sodium gluconate. Bi@Bi{sub 2}O{sub 3}@CRCSs exhibits significant enhanced photocatalytic activity under visible light irradiation (λ > 420 nm) and shows an O{sub 2}-dependent feature. According to trapping experiments of radicals and holes, hydroxyl radicals were not the main active oxidative species in the photocatalytic degradation of MB, but O{sub 2}·{sup −} are the main active oxidative species.

  15. The distribution of {sup 137}Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Vinichuk, M., E-mail: mykhailo.vinichuk@mark.slu.s [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Department of Ecology, Zhytomyr State Technological University, 103 Chernyakhovsky Street, 10005 Zhytomyr (Ukraine); Johanson, K.J. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Rydin, H. [Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvaegen 18D, SE-752 36 Uppsala (Sweden); Rosen, K. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden)

    2010-02-15

    We record the distribution of {sup 137}Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as {sup 137}Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris{sup 137}Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher {sup 137}Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of {sup 137}Cs within the plants. The patterns of {sup 137}Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The {sup 137}Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between {sup 137}Cs and Rb (r = 0.89), and between {sup 137}Cs and stable Cs (r = 0.84). This suggests similarities between {sup 137}Cs and Rb in uptake and relocation within the Sphagnum, but that {sup 137}Cs differs from K.

  16. Co-localization of a CD1d-binding glycolipid with an adenovirus-based malaria vaccine for a potent adjuvant effect.

    Science.gov (United States)

    Li, Xiangming; Huang, Jing; Kawamura, Akira; Funakoshi, Ryota; Porcelli, Steven A; Tsuji, Moriya

    2017-05-31

    A CD1d-binding, invariant (i) natural killer T (NKT)-cell stimulatory glycolipid, α-Galactosylceramide (αGalCer), has been shown to act as an adjuvant. We previously identified a fluorinated phenyl ring-modified αGalCer analog, 7DW8-5, displaying a higher binding affinity for CD1d molecule and more potent adjuvant activity than αGalCer. In the present study, 7DW8-5 co-administered intramuscularly (i.m.) with a recombinant adenovirus expressing a Plasmodium yoelii circumsporozoite protein (PyCSP), AdPyCS, has led to a co-localization of 7DW8-5 and a PyCSP in draining lymph nodes (dLNs), particularly in dendritic cells (DCs). This occurrence initiates a cascade of events, such as the recruitment of DCs to dLNs and their activation and maturation, and the enhancement of the ability of DCs to prime CD8+ T cells induced by AdPyCS and ultimately leading to a potent adjuvant effect and protection against malaria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Derivation of 137Cs deposition density from measurement of 137Cs inventories in undisturbed soils

    International Nuclear Information System (INIS)

    Hien, P.D.; Hiep, H.T.; Quang, N.H.; Huy, N.Q.; Binh, N.T.; Hai, P.S.; Long, N.Q.; Bac, V.T

    2012-01-01

    The 137 Cs inventories in undisturbed soils were measured for 292 locations across the territory of Vietnam. the logarithmic inventory values were regressed against characteristics of sampling sites, such as geographical coordinates, annual rainfall and physico-chemical parameters of soil. The regression model containing latitude and annual rainfall as determinants could explain 76% of the variations in logarithmic inventory values across the territory. The model part was interpreted as the logarithmic 137 Cs deposition density. At the 95% confidence level, 137 Cs deposition density could be predicted be the model ± 7% relative uncertainty. the latitude mean 137 Cs deposition density increases northward from 237 Bq m -2 to 1097 Bq m -2 , while the corresponding values derived from the UNSCEAR (1969) global pattern are 300 Bq m -2 and 600 Bq m -2 . High 137 Cs inputs were found in high-rainfall areas in northern and central parts of the territory. (author)

  18. Enhancement of CD147 on M1 macrophages induces differentiation of Th17 cells in the lung interstitial fibrosis.

    Science.gov (United States)

    Geng, Jie-jie; Zhang, Kui; Chen, Li-na; Miao, Jin-lin; Yao, Meng; Ren, Ying; Fu, Zhi-guang; Chen, Zhi-nan; Zhu, Ping

    2014-09-01

    Lung interstitial fibrosis is a chronic lung disease, and few effective therapies are available to halt or reverse the progression of the disease. In murine and human lung fibrosis, the expression of CD147 is increased. However, the role of CD147 in lung fibrosis has not been identified, and it remains to be determined whether lung fibrosis would be improved by decreasing the expression of CD147. A murine bleomycin-induced lung interstitial fibrosis model was used in the experiments, and HAb18 mAbs and CsA were administered during the induction of lung fibrosis. In our study, we found that the HAb18 mAbs markedly reduced the collagen score and down-regulated M1 macrophages and Th17 cells. In vitro, flow cytometry analysis showed that M1 macrophages induced higher Th17 differentiation than M2 macrophages. After treatment with HAb18 mAbs or after reducing the expression of CD147 by lentivirus interference in M1 macrophages, the level of Th17 cells were significantly inhibited. In conclusion, HAb18 mAbs or CsA treatment ameliorates lung interstitial fibrosis. CD147 promoted M1 macrophage and induced the differentiation of Th17 cells in lung interstitial fibrosis, perhaps by regulating some cytokines such as IL-6, IL-1β, IL-12 and IL-23. These results indicated that CD147 may play an important role in the development of lung interstitial fibrosis. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Topotactic synthesis of a new BiS2-based superconductor Bi2(O,F)S2

    Science.gov (United States)

    Okada, Tomoyuki; Ogino, Hiraku; Shimoyama, Jun-ichi; Kishio, Kohji

    2015-02-01

    A new BiS2-based superconductor, Bi2(O,F)S2, was discovered. It is a layered compound consisting of alternately stacked structure of rock-salt-type BiS2 superconducting layers and fluorite-type Bi(O,F) blocking layers. Bi2(O,F)S2 was obtained as the main phase by topotactic fluorination of undoped Bi2OS2 using XeF2. This is the first topotactic synthesis of an electron-doped superconductor via reductive fluorination. With increasing F-content, a- and c-axis lengths increased and decreased, respectively, and Tc increased to 5.1 K.

  20. Cúmulos globulares como trazadores de bimodalidad estelar en galaxias cD

    Science.gov (United States)

    Forte, J. C.

    Se muestra que tanto la forma de los perfiles de brillo como de color observados en dos galaxias arquetípicas de tipo cD (NGC 1399 y NGC 4486) son compatibles con la presencia de poblaciones estelares bi-modales que comparten la misma distribución espacial y composición química de las familias dominantes de cúmulos globulares asociadas con ellas. El modelo resultante también predice una variación de la frecuencia específica de los cúmulos como función del radio galactocéntrico. Se discute este resultado en el contexto de una variedad de escenarios astrofísicos que intentan describir la formación de galaxias cD.

  1. TmCd quadrupolar ordering and magnetic interactions

    International Nuclear Information System (INIS)

    Aleonard, R.; Morin, P.

    1979-01-01

    The paramagnetic compound TmCd crystallizes with the CsCl-type structure. Its Jahn-Teller behavior was first observed by Luethi and coworkers. We analyze here various physical properties with a pure-harmonic-elasticity model. The structural transition between cubic and tetragonal phases is now fully described (first-order character and temperature of occurrence) as well as the magnetic susceptibility, magnetization process, specific-heat, elastic-constant, and strain data. The relevant Hamiltonian takes into account the second-order magnetoelastic coupling and the quadrupolar exchange in addition to the cubic crystal field and the Heisenberg bilinear interactions. TmCd appears to be closely related to isomorphous TmZn and completes the illustration of the competition between bilinear and quadrupolar interactions occurring in some rare-earth intermetallics. In these two compounds, the quadrupolar exchange is many times stronger than the magnetoelastic coupling and the quadrupolar ordering then drives the structural transition. This situation is opposite to that occurring in (actual) Jahn-Teller compounds

  2. Sodium citrate-assisted anion exchange strategy for construction of Bi2O2CO3/BiOI photocatalysts

    International Nuclear Information System (INIS)

    Song, Peng-Yuan; Xu, Ming; Zhang, Wei-De

    2015-01-01

    Highlights: • Heterostructured Bi 2 O 2 CO 3 /BiOI microspheres were prepared via anion exchange. • Sodium citrate-assisted anion exchange for construction of composite photocatalysts. • Bi 2 O 2 CO 3 /BiOI composites show high visible light photocatalytic activity. - Abstract: Bi 2 O 2 CO 3 /BiOI heterojuncted photocatalysts were constructed through a facile partial anion exchange strategy starting from BiOI microspheres and urea with the assistance of sodium citrate. The content of Bi 2 O 2 CO 3 in the catalysts was regulated by modulating the amount of urea as a precursor, which was decomposed to generate CO 3 2− in the hydrothermal process. Citrate anion plays a key role in controlling the morphology and composition of the products. The Bi 2 O 2 CO 3 /BiOI catalysts display much higher photocatalytic activity than pure BiOI and Bi 2 O 2 CO 3 towards the degradation of rhodamine B (RhB) and bisphenol A (BPA). The enhancement of photocatalytic activity of the heterojuncted catalysts is attributed to the formation of p–n junction between p-BiOI and n-Bi 2 O 2 CO 3 , which is favorable for retarding the recombination of photoinduced electron-hole pairs. Moreover, the holes are demonstrated to be the main active species for the degradation of RhB and BPA

  3. Determination of Sr, Ba, Rb, and Cs in biological reference materials using a radiochemical NAA group separation procedure

    International Nuclear Information System (INIS)

    Mizera, J.; Randa, Z.

    2008-01-01

    Strontium, barium, rubidium, and cesium in selected, predominantly biological, reference materials (NIST 1515, 1547, 1549, 1566a, 1571, 1577b, 2704, CTA-OTL-1, and Bowen's Kale) were determined using neutron activation analysis (NAA) in two different analytical modes - instrumental NAA with epithermal neutrons (ENAA), and NAA with radiochemical group separation of Sr-Ba and Rb-Cs (RNAA). The ENAA mode was based on long-term (5 h) irradiation of samples in a Cd shielding. The RNAA procedure was based on long-term (20 h) irradiation of samples, their decomposition / dissolution by alkaline-oxidative fusion, and precipitation of Sr and Ba sulfates, and sorption of Rb and Cs onto ammonium phosphomolybdate (APM). Both methods provided element contents in the analyzed reference materials consistent with certified and/or literature values. (author)

  4. Examination of the role of CS{sub 2} in the CS{sub 2}/NMP mixed solvents to coal extraction

    Energy Technology Data Exchange (ETDEWEB)

    Shui, Hengfu; Wang, Zhicai [School of Chemistry and Chemical Engineering, Anhui University of Technology, 243002 Maanshan Anhui (China); Gao, Jinsheng [Department of Energy Resources and Chemical Engineering, East China University of Science & amp; Technology, 200237 Shanghai (China)

    2006-02-15

    The roles of CS{sub 2} in the CS{sub 2}/NMP mixed solvent to coal extraction and solubilization were investigated in this study. There was little effect of removing of CS{sub 2} from the solutions on the solubilities of UF coal extract and pyridine insoluble (PI) of the extract in the NMP/CS{sub 2} mixed solvent, suggesting that NMP has high enough solubilities to the UF coal extract and PI. Six Argonne different rank coals were extracted with the CS{sub 2}/NMP mixed solvent and NMP, respectively. It was found that the extraction yield difference between NMP and CS{sub 2}/NMP mixed solvent for UF coal is largely deviated from the curve obtained for the other 5 coals, suggesting that the pre-swelling of CS{sub 2} in the mixed solvent may be one of important roles for high extraction yield of UF coal in the CS{sub 2}/NMP mixed solvent. FTIR indicated that there was a strong interaction between CS{sub 2} and NMP in the CS{sub 2}/NMP mixed solvent of 1:1 volume ratio, which made the strong absorbance at 2156 cm{sup -1} in the FTIR spectra, and this interaction may disrupt the dipole based association of NMP thus making the CS{sub 2}/NMP mixed solvent lower viscosity, to penetrate more quickly into the network structure of coal, resulting in the larger solvent partner (NMP) to enter and break the stronger coal-coal interactions. (author)

  5. Transformation of Sintered CsPbBr3 Nanocrystals to Cubic CsPbI3 and Gradient CsPbBrxI3-x through Halide Exchange.

    Science.gov (United States)

    Hoffman, Jacob B; Schleper, A Lennart; Kamat, Prashant V

    2016-07-13

    All-inorganic cesium lead halide (CsPbX3, X = Br(-), I(-)) perovskites could potentially provide comparable photovoltaic performance with enhanced stability compared to organic-inorganic lead halide species. However, small-bandgap cubic CsPbI3 has been difficult to study due to challenges forming CsPbI3 in the cubic phase. Here, a low-temperature procedure to form cubic CsPbI3 has been developed through a halide exchange reaction using films of sintered CsPbBr3 nanocrystals. The reaction was found to be strongly dependent upon temperature, featuring an Arrhenius relationship. Additionally, film thickness played a significant role in determining internal film structure at intermediate reaction times. Thin films (50 nm) showed only a small distribution of CsPbBrxI3-x species, while thicker films (350 nm) exhibited much broader distributions. Furthermore, internal film structure was ordered, featuring a compositional gradient within film. Transient absorption spectroscopy showed the influence of halide exchange on the excited state of the material. In thicker films, charge carriers were rapidly transferred to iodide-rich regions near the film surface within the first several picoseconds after excitation. This ultrafast vectorial charge-transfer process illustrates the potential of utilizing compositional gradients to direct charge flow in perovskite-based photovoltaics.

  6. Concentrations of /sup 113m/Cd in the marine environment

    Energy Technology Data Exchange (ETDEWEB)

    Noshkin, V.E.; Wong, K.M.; Eagle, R.J.; Anglin, D.L.

    1980-09-18

    Reports on the detection of /sup 113m/Cd in any type of environmental sample have been rare. The 113 mass chain yield is small relative to other longer-lived fission products, such as /sup 90/Sr and /sup 137/Cs, produced from uranium, plutonium and thorium fissions. Also, only a small fraction of the 113 chain yield decays to /sup 113m/Cd. Salter estimated that the /sup 113m/Cd//sup 90/Sr activity quotient in thermonuclear fission should be 0.003. He stated that this ratio is in good agreement with data from a few samples measured in the northern hemisphere prior to 1962 which have no /sup 109/Cd. This, to our knowledge, was the first report of the detection of fission-produced /sup 113m/Cd in the environment. Salter also calculated that 0.062 MCi of /sup 113m/Cd and 0.25 MCi of /sup 109/Cd were produced by activation during the atmospheric detonation of the 1.4-megaton Starfish device on 9 July 1962 over Johnston Atoll. As both /sup 109/Cd and /sup 113m/Cd are produced during neutron activation of stable cadmium, and /sup 109/Cd is not a fission product, the last part of Salter's statement is significant. The absence of /sup 109/Cd in samples collected before 1962 indicates that all nuclear testing before this time, which included all tests conducted at Enewetak and Bikini Atolls in the Marshall Islands, could have generated /sup 113m/Cd only as a fission product. It is therefore important to recognize that /sup 113m/Cd could be present in other environments contaminated with fission product wastes discharged to the aquatic environment from other nuclear facilities. /sup 113m/Cd has a half life of 14.6 +- 0.1 y and decays predominantly by beta-particle emission. We present here a preliminary report of /sup 113m/Cd concentrations measured in sediment and tissue samples of marine organisms collected around different atolls in the Marshall Islands.

  7. A study of {sup 137}Cs in soil profiles from the Marshall Islands

    Energy Technology Data Exchange (ETDEWEB)

    Graham, J.C.; Simon, S.L. [Republic of the Marshall Islands, Nationwide Radiological Study, Majuro, MH (Marshall Islands)

    1996-04-11

    In late 1989, the Republic of the Marshall Islands commissioned an independent radiological monitoring program to determine the degree of deposition and the geographical extent of atomic weapons test fallout over its islands. The sampling and measurement of {sup 137}Cs in vertical soil profiles has been an important part of that monitoring program. Over 200 profiles were collected in 5-cm increments to a depth of 30 cm, including locations at all 29 of the nation`s atolls and five separate reef islands. Annual rainfall and soil particle size distribution was studied to determine the inter-relationships with cesium permeation and areal inventory (Bq/m{sup 2}). Relaxation lengths of cesium in the soil column were calculated from measurements of {sup 137}Cs activity in profile increments. Using a common model for a depth-dependent concentration gradient (C(d) C{sub o} e{sup -{alpha}d}), the inverse of the rate of change of concentration (i.e. 1/{alpha}) has been defined as the relaxation length of the profile. In this study, the relaxation length was calculated from the concentration data of the first three sample increments (i.e. 0 - 5, 5 - 10, 10 - 15 cm) and from all six increments to a total depth of 30 cm. Typical values for relaxation lengths in the drier northern atolls are 7 - 12 cm, though our observations included values between -800 and 3500 cm. Our findings showed that {sup 137}Cs permeation was highly variable with particle size, though relaxation length was significantly correlated with annual rainfall. Areal inventory was determined to be significantly correlated with the 0 - 5 cm {sup 137}Cs soil concentration. The 0 - 30 cm fitted relaxation length was also determined to give a good estimate of the areal inventory of {sup 137}Cs in the soil to a depth of 30 cm regardless of the rate of change in concentration with depth.

  8. Electrodeposition of CdTe thin films onto n-Si(1 0 0): nucleation and growth mechanisms

    International Nuclear Information System (INIS)

    Gomez, H.; Henriquez, R.; Schrebler, R.; Cordova, R.; Ramirez, D.; Riveros, G.; Dalchiele, E.A.

    2005-01-01

    The mechanisms related to the initial stages of the nucleation and growth of cadmium telluride (CdTe) thin films on the rough face side of a (1 0 0) monocrystalline n-type silicon have been studied as a function of different potential steps that varied from an initial value of -0.200 V to values comprised between -0.515 and -0.600 V versus saturated calomel electrode (SCE). The analysis of the corresponding potentiostatic j/t transients suggests that the main phenomena involved at short times is the formation of a Te-Cd bi-layer (BL). For potentials below -0.540 V, the formation of this bi-layer can be considered independent of potential. At greater times, the mechanisms is controlled by two process: (i) progressive nucleation three dimensional charge transfer controlled growth (PN-3D) ct and (ii) progressive nucleation three dimensional diffusion controlled growth (PN-3D) diff , both giving account for the formation of conical and hemispherical nuclei, respectively. Ex situ AFM images of the surface seem to support these assumptions

  9. Optimization of excess Bi doping to enhance ferroic orders of spin casted BiFeO{sub 3} thin film

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Surbhi; Gupta, Vinay, E-mail: drguptavinay@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi (India); Tomar, Monika [Department of Physics, Miranda Housea, University of Delhi, Delhi (India); James, A. R. [Defence Metallurgical Research Laboratory, Hyderabad (India); Pal, Madhuparna; Guo, Ruyan; Bhalla, Amar [Department of Electrical and Computer Engineering, College of Engineering, University of Texas at SanAntonio, San Antonio 78249 (United States)

    2014-06-21

    Multiferroic Bismuth Ferrite (BiFeO{sub 3}) thin films with varying excess bismuth (Bi) concentration were grown by chemical solution deposition technique. Room temperature multiferroic properties (ferromagnetism, ferroelectricity, and piezoelectricity) of the deposited BiFeO{sub 3} thin films have been studied. High resolution X-ray diffraction and Raman spectroscopy studies reveal that the dominant phases formed in the prepared samples change continuously from a mixture of BiFeO{sub 3} and Fe{sub 2}O{sub 3} to pure BiFeO{sub 3} phase and, subsequently, to a mixture of BiFeO{sub 3} and Bi{sub 2}O{sub 3} with increase in the concentration of excess Bi from 0% to 15%. BiFeO{sub 3} thin films having low content (0% and 2%) of excess Bi showed the traces of ferromagnetic phase (γ-Fe{sub 2}O{sub 3}). Deterioration in ferroic properties of BiFeO{sub 3} thin films is also observed when prepared with higher content (15%) of excess Bi. Single-phased BiFeO{sub 3} thin film prepared with 5% excess Bi concentration exhibited the soft ferromagnetic hysteresis loops and ferroelectric characteristics with remnant polarization 4.2 μC/cm{sup 2} and saturation magnetization 11.66 emu/g. The switching of fine spontaneous domains with applied dc bias has been observed using piezoresponse force microscopy in BiFeO{sub 3} thin films having 5% excess Bi. The results are important to identify optimum excess Bi concentration needed for the formation of single phase BiFeO{sub 3} thin films exhibiting the improved multiferroic properties.

  10. Investigation of the electronic structure of the BiSBr and BiSeBr clusters by density functional method

    International Nuclear Information System (INIS)

    Audzijonis, A.; Gaigalas, G.; Zigas, L.; Pauliukas, A.; Zaltauskas, R.; Kvedaravicius, A.; Cerskus, A.

    2008-01-01

    The energy levels of valence bands (VB) of the BiSBr and BiSeBr crystals have been calculated for investigation of the photoelectron emission spectra of BiSBr, BiSeBr and BiSI crystals. The molecular model of this crystal has been used for the calculation of VB by the Density Functional Theory (DFT) method. The molecular cluster, consisting of 20 molecules of BiSBr, BiSeBr, has been used for calculations of averaged total density of states, including atom vibrations. The spectra of the averaged total density of states from VB of BiSBr and BiSeBr clusters have been compared with the experimental photoelectron emission spectra from VB of BiSI crystals. The results clarify that the atomic vibrations in A 5 B 6 C 7 type crystals with chain structure create a smoother appearance of the averaged total density of state spectrum and the experimental X-ray photoemission spectra (XPS)

  11. Lineage determination of CD7+ CD5- CD2- and CD7+ CD5+ CD2- lymphoblasts: studies on phenotype, genotype, and gene expression of myeloperoxidase, CD3 epsilon, and CD3 delta.

    Science.gov (United States)

    Yoneda, N; Tatsumi, E; Teshigawara, K; Nagata, S; Nagano, T; Kishimoto, Y; Kimura, T; Yasunaga, K; Yamaguchi, N

    1994-04-01

    The gene expression of myeloperoxidase (MPO), CD3 epsilon, and CD3 delta molecules, the gene rearrangement of T-cell receptor (TCR) delta, gamma, and beta and immunoglobulin heavy (IgH) chain, and the expression of cell-surface antigens were investigated in seven cases of CD7+ CD5- CD2- and four cases of CD7+ CD5+ CD2- acute lymphoblastic leukemia or lymphoblastic lymphoma (ALL/LBL) blasts, which were negative for cytochemical myeloperoxidase (cyMPO). More mature T-lineage blasts were also investigated in a comparative manner. In conclusion, the CD7+ CD5- CD2- blasts included four categories: undifferentiated blasts without lineage commitment, T-lineage blasts, T-/myeloid lineage blasts, and cyMPO-negative myeloblasts. The CD7+ CD5+ CD2- blasts included two categories; T-lineage and T-/myeloid lineage blasts. The 11 cases were of the germ-line gene (G) for TCR beta and IgH. Four cases were G for TCR delta and TCR gamma. The others were of the monoclonally rearranged gene (R) for TCR delta and G for TCR gamma or R for both TCR delta and TCR gamma. The expression or in vitro induction of CD13 and/or CD33 antigens correlated with the immaturity of these neoplastic T cells, since it was observed in all 11 CD7+ CD5- CD2- and CD7+ CD5+ CD2-, and some CD7+ CD5+ CD2+ (CD3- CD4- CD8-) cases, but not in CD3 +/- CD4+ CD8+ or CD3+ CD4+ CD8- cases. CD3 epsilon mRNA, but not CD3 delta mRNA, was detected in two CD7+ CD5- CD2- cases, while mRNA of neither of the two CD3 molecules was detected in the other tested CD7+ CD5- CD2- cases. In contrast, mRNA of both CD3 epsilon and CD3 delta were detected in all CD7+ CD5+ CD2- cases, indicating that CD7+ CD5- CD2- blasts at least belong to T-lineage. The blasts of two CD7+ CD5- CD2- cases with entire germ-line genes and without mRNA of the three molecules (MPO, CD3 epsilon, and CD3 delta) were regarded as being at an undifferentiated stage prior to their commitment to either T- or myeloid-lineage. The co-expression of the genes of MPO

  12. [Sensitive determination of Bi3+ by spectrofluorimetry based on graphene oxide-methylene blue system].

    Science.gov (United States)

    Zhai, Qiu-ge; Guo, Peng; Zhou, Lin; Liu, Yan-ming

    2014-08-01

    Graphene oxide was prepared by the modified Hummers method and characterized by field emission scanning electron microscopy. The interaction of graphene with methylene blue was studied by UV absorption, the intensity of two main absorption peaks of methylene blue decreased significantly after the fluorescence was quenched, and the energy transfer didn't occur because the overlap of the absorption spectrum of GO and the emission spectrum of MB is too small. Therefore, the fluorescence quenching of MB and GO was static. When adding a certain amount of Bi3+ in the graphene-methylene blue system, Bi3+ replaces the methylene blue from the graphene-methylene blue complexes because Bi3+ has the smaller volume and is more positively charged. The methylene blue therefore dissociates from the GO-MB complexes, resulting in the recovery of fluorescence of the system. Furthermore, the fluorescence of the system increases with the increase in the amount of Bi3+ due to the enhanced amount of MB in the system. A novel spectrofluorimetric method was therefore developed for the sensitive determination of Bi3+. Some parameters including the concentration of methylene blue, the amount of graphene oxide, the amount of nitric acid and the sequence of reagent adding were optimized to obtain higher sensitivity. The fluorescence of the system was detected at an emission wavelength of 667 nm with excitation at 690 nm. Under the optimized conditions, the concentration of Bi3+ showed good linear relationships with the fluorescence intensity in the range of 0.5-100 micromol x L(-1), with correlation coefficients of r = 0.9955. The limits of detection for Bi3+ was 1.0 x 10(-8) mol x L(-1) (S/N=3). The selectivity of the proposed method was evaluated and the results showed that 1000-fold K+, Ca+, Na+, Mg2+, Cu2+; 100-fold Fe3+, Be2+, SiO2- Al3+, Ni2+, Sb3+, NO3-, Cl-, F-, and 20-fold Pb2+, Hg2+, Cd2+ had negligible interference with the determination of Bi3+. The method has advantages of

  13. Correlations between potassium, rubidium and cesium ({sup 133}Cs and {sup 137}Cs) in sporocarps of Suillus variegatus in a Swedish boreal forest

    Energy Technology Data Exchange (ETDEWEB)

    Vinichuk, M., E-mail: Mykhailo.Vinichuk@slu.s [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Department of Ecology, Zhytomyr State Technological University, 103 Cherniakhovsky Str., 10005 Zhytomyr (Ukraine); Rosen, K.; Johanson, K.J. [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Dahlberg, A. [Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences, P.O. Box 7026, 750 07 Uppsala (Sweden)

    2011-04-15

    An analysis of sporocarps of ectomycorrhizal fungi Suillus variegatus assessed whether cesium ({sup 133}Cs and {sup 137}Cs) uptake was correlated with potassium (K) or rubidium (Rb) uptake. The question was whether intraspecific correlations of Rb, K and {sup 133}Cs mass concentrations with {sup 137}Cs activity concentrations in sporocarps were higher within, rather than among, different fungal species, and if genotypic origin of sporocarps within a population affected uptake and correlation. Sporocarps (n = 51) from a Swedish forest population affected by the fallout after the Chernobyl accident were studied. The concentrations were 31.9 {+-} 6.79 g kg{sup -1} for K (mean {+-} SD, dwt), 0.40 {+-} 0.09 g kg{sup -1} for Rb, 8.7 {+-} 4.36 mg kg{sup -1} for {sup 133}Cs and 63.7 {+-} 24.2 kBq kg{sup -1} for {sup 137}Cs. The mass concentrations of {sup 133}Cs correlated with {sup 137}Cs activity concentrations (r = 0.61). There was correlation between both {sup 133}Cs concentrations (r = 0.75) and {sup 137}Cs activity concentrations (r = 0.44) and Rb, but the {sup 137}Cs/{sup 133}Cs isotopic ratio negatively correlated with Rb concentration. Concentrations of K and Rb were weakly correlated (r = 0.51). The {sup 133}Cs mass concentrations, {sup 137}Cs activity concentrations and {sup 137}Cs/{sup 133}Cs isotopic ratios did not correlate with K concentrations. No differences between, within or, among genotypes in S. variegatus were found. This suggested the relationships between K, Rb, {sup 133}Cs and {sup 137}Cs in sporocarps of S. variegatus is similar to other fungal species. - Highlights: {yields} We studied uptake of Cs ({sup 133}Cs and {sup 137}Cs), K and Rb by Suillus variegates sporocarps. {yields} Genotypic origin of fungus did not affect uptake of studied elements (isotopes). {yields} Genotypic origin did not affect correlation between Cs ({sup 133}Cs and {sup 137}Cs), K and Rb.

  14. 137Cs in northern Adriatic sediments

    International Nuclear Information System (INIS)

    Barisic, D.; Lulic, S.; Vdovic, N.; Vertacnik, A.; Juracic, M.

    1996-01-01

    The activity of 137 Cs in shallow northern Adriatic sediments was obtained on the basis of measurement results from 25 sediment box cores, sampled during the Adriatic Scientific COoperation Program (ASCOP) 16 cruise in the summer 1990. 137 Cs was determined in surface sediments (0-3 cm) and 12-15 cm-deep sediment. It was found that the lowest caesium concentrations correspond to sands, which are spread along the Croatian coast. Parallel to the Italian coast, 137 Cs concentrations in pelites are the highest. It seems that the influence of Po River is significant for 137 Cs activities in recent marine sediments along Italian coast south of Po River delta. Significantly higher 137 Cs activities in 0-3 cm sediment layer can be attributed to the deposition caused by Chernobyl accident. (author)

  15. Luminescence of Bi3+ ions in Y3Al5O12:Bi single crystalline films

    International Nuclear Information System (INIS)

    Zorenko, Yu.; Gorbenko, V.; Voznyak, T.; Vistovsky, V.; Nedilko, S.; Nikl, M.

    2007-01-01

    The absorption and cathodoluminescence spectra of single crystalline films (SCF) of Y 3 Al 5 O 12 :Bi garnet depending on Bi concentration were analyzed. For consideration of the nature of the UV and visible Bi-related emission bands the time-resolved luminescence of Bi 3+ (ns 2 ) ions in YAG:Bi SCF was studied at 10 K under excitation by synchrotron radiation. The difference in the excitation spectra and emission decay of the UV and visible bands has been explained via radiative relaxation from the 3 P 1,0 excited states to the 1 S 0 ground state of the isolated and pair/clustered Bi 3+ emission centers in the garnet lattice, respectively

  16. Response of MnBi-Bi eutectic to freezing rate changes

    Science.gov (United States)

    Nair, M.; Fu, T.-W.; Wilcox, W. R.; Doddi, K.; Ravishankar, P. S.; Larson, D.

    1982-01-01

    Reference is made to a study by Fu and Wilcox (1981), which treated theoretically the influence on freezing rate of sudden changes in translation rate in the Bridgman-Stockbarger technique. This treatment is extended here to a linear ramped translation rate and an oscillatory freezing rate. It is found that oscillations above a few hertz are highly damped in small-diameter apparatus. An experimental test is carried out of the theoretical predictions for a sudden change of translation rate. The MnBi-Bi eutectic is solidified with current-induced interface demarcation. The experimental results accord reasonably well with theory if the silica ampoule wall is assumed to either (1) contribute only a resistance to heat exchange between the sample and the furnace wall or (2) transmit heat effectively in the axial direction by radiation. In an attempt to explain the fact that a finer microstructure is obtained in space, MnBi-Bi microstructure is determined when the freezing rate is increased or decreased rapidly. Preliminary results suggest that fiber branching does not occur as readily as fiber termination.

  17. Environmental radioactivity of radon daughter's radionuclides 210Pb-210Bi-210Po

    International Nuclear Information System (INIS)

    Momoshima, N.

    2003-01-01

    Radionuclide, 210 Pb(22.3 y)- 210 Bi(5.013 d)- 210 Po(138.4 d) belongs to the uranium decay chain and widely distributed in the environment. 222 Rn escaped from the earth surface is a major source of atmospheric 210 Pb. These nuclides attach with atmospheric aerosols and are removed to the ground as wet and dry depositions. The residence time of the atmospheric aerosol, thus, was obtained by activity ratios of 210 Bi/ 210 Pb and 210 Po/ 210 Pb, showing different values. The discrepancy on the residence times are explained with inputs of 210 Po to the atmosphere other than 222 Rn emanated from the earth surface. The removal of aerosol as wet deposition occupies a significant fraction, which reaches 72% on 210 Pb and 89% on 7 Be. In the ocean, the radionuclides are used as tracer to examine dynamic processes occurring in the ocean, such as removal of particulate matter from seawater column to bottom. The 210 Pb and 210 Po concentrations in the ocean water collected off continent decreased from surface toward bottom, and the shortage on 210 Po content relative to that of 210 Po was observed at shallow ocean layers, however, the 210 Po/ 210 Pb activity ratio closed to the radioactive equilibrium at deeper layers. The 210 Pb is a very good tracer to evaluate an accumulation rate of bottom sediment in ocean, lake and river. This is called as 210 Pb dating and is successfully applicable to accumulation circumstances that bottom sediment deposits at constant rate. Most of the actual cases, simultaneous 137 Cs dating is carried out, which uses 137 Cs peak in the core as originated from radioactive fallout of nuclear tests, showing the maximum in 1963. Recently new findings on source of atmospheric 210 Po are report by laboratory experiments and environmental measurements, which proves biologically supported emission of volatile Po compounds to the atmosphere. (author)

  18. 137Cs metabolism in pregnant women

    International Nuclear Information System (INIS)

    Melo, D.R.; Lipsztein, J.L.; Oliveira, C.A.N.; Bertelli, L.

    2000-01-01

    Data from two pregnant women contaminated with 137 Cs, body burdens of 0.2 and 300 MBq, respectively at the time of the Goiania accident, were compared. The first one, with lower body burden was exposed during the fourth month of pregnancy, while the second became pregnant three years and eight months after 137 Cs intake. For the first woman 137 Cs concentrations were equal for the mother, infant and placenta, indicating an easy and homogeneous transport of 137 Cs from mother to foetus. The whole body monitoring data from the second woman, who became pregnant four years after intake, did not show a reduction in biological half-life during the pregnancy. Cs concentration in the mother was found to be 13 times higher than in the infant. One possible reason for this result is that four years after intake, Cs is supposed to be concentrated mainly in skeletal muscle tissue. During the pregnancy the blood flux becomes higher in most of the organs and tissues except brain, liver and skeletal muscle tissue. (author)

  19. Estimation of average burnup of damaged fuels loaded in Fukushima Dai-ichi reactors by using the 134Cs/137Cs ratio method

    International Nuclear Information System (INIS)

    Endo, T.; Sato, S.; Yamamoto, A.

    2012-01-01

    Average burnup of damaged fuels loaded in Fukushima Dai-ichi reactors is estimated, using the 134 Cs/ 137 Cs ratio method for measured radioactivities of 134 Cs and 137 Cs in contaminated soils within the range of 100 km from the Fukushima Dai-ichi nuclear power plants. As a result, the measured 134 Cs/ 137 Cs ratio from the contaminated soil is 0.996±0.07 as of March 11, 2011. Based on the 134 Cs/ 137 Cs ratio method, the estimated burnup of damaged fuels is approximately 17.2±1.5 [GWd/tHM]. It is noted that the numerical results of various calculation codes (SRAC2006/PIJ, SCALE6.0/TRITON, and MVP-BURN) are almost the same evaluation values of 134 Cs/ 137 Cs ratio with same evaluated nuclear data library (ENDF-B/VII.0). The void fraction effect in depletion calculation has a major impact on 134 Cs/ 137 Cs ratio compared with the differences between JENDL-4.0 and ENDF-B/VII.0. (authors)

  20. Photoreduction of non-noble metal Bi on the surface of Bi{sub 2}WO{sub 6} for enhanced visible light photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaojing [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China); The Center of New Energy Materials and Technology, School of Materials Science and Engineering, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China); Yu, Shan; Liu, Yang; Zhang, Qian [The Center of New Energy Materials and Technology, School of Materials Science and Engineering, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China); Zhou, Ying, E-mail: yzhou@swpu.edu.cn [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China); The Center of New Energy Materials and Technology, School of Materials Science and Engineering, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China)

    2017-02-28

    Highlights: • Bi{sub 2}WO{sub 6}-Bi composite was synthesized by in situ photoreduction of Bi{sub 2}WO{sub 6}. • Bi{sub 2}WO{sub 6}-Bi exhibits improved photocatalytic efficiency towards degradation of Rhodamine B. • The generation of elemental Bi in Bi{sub 2}WO{sub 6}-Bi induces vacancy and structure distortion of Bi{sub 2}WO{sub 6}. • The surface oxygen adsorption mode changes from hydroxyl group on Bi{sub 2}WO{sub 6} to molecular oxygen on Bi{sub 2}WO{sub 6}-Bi. - Abstract: In this report, Bi{sub 2}WO{sub 6}-Bi composite was prepared through an in situ photoreduction method and was characterized systematically by X-Ray diffraction, transmission electron microscopy, X-Ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. The as-prepared Bi{sub 2}WO{sub 6}-Bi maintains the same crystal structure with the pristine Bi{sub 2}WO{sub 6} regardless of some surface defects. Nevertheless, these surface defects result in the change of surface oxygen adsorption mode from hydroxyl to molecular oxygen on Bi{sub 2}WO{sub 6}. Photocatalytic activity over Bi{sub 2}WO{sub 6}-Bi is 2.4 times higher than that of Bi{sub 2}WO{sub 6} towards the degradation of organic dye Rhodamine B (RhB) under visible light irradiation (λ > 420 nm). A deep study shows that cleavage of benzene ring is the main pathway for RhB degradation over Bi{sub 2}WO{sub 6}, but both the benzene cleavage and de-ethylation pathway coexist for RhB decomposition in the presence of Bi{sub 2}WO{sub 6}-Bi as the photocatalyst. Photoelectrochemical study including transient photocurrent tests and electrochemical impedance spectroscopy measurements shows that Bi{sub 2}WO{sub 6}-Bi could facilitate the charge transfer process compared to Bi{sub 2}WO{sub 6}. These data above has indicated a new insight into the promotion mechanism based on Bi related heterostructures.

  1. Waste forms based on Cs-loaded silicotitanates

    International Nuclear Information System (INIS)

    Balmer, M.L.; Bunker, B.C.

    1995-04-01

    Silicotitanate ion exchange materials are being considered for removal of radioactive Cs and Sr from tank wastes at the Hanford site. The phase evolution as a function of heat treatment temperature for several sol gel derived compositions within the Cs 2 O-SiO 2 -TiO 2 system was investigated, in order to determine if an adequate waste form can be achieved by direct thermal conversion. The Cs leach rates and Cs loss during heat treatment of select materials were measured. Some compositions which contain large amounts of Ti melt to form a glass with reasonably low aqueous leach rates. A new Cs-silicotitanate material with a structure isomorphous to pollucite was discovered. This material forms at low temperatures (700--800 C) where Cs volatility is negligible. The silicotitanate-pollucite exhibits extremely low leach rates (1.42 g/m 2 day ) at 90 C, and has been identified as a promising waste form for Cs containment

  2. Trace elements in primitive meteorites—VII Antarctic unequilibrated ordinary chondrites

    Science.gov (United States)

    Wang, Ming-Sheng; Lipschutz, Michael E.

    2007-02-01

    We report RNAA results for Co, Au, Sb, Ga, Rb, Cs, Se, Ag, Te, Zn, In, Bi, Tl and Cd (in increasing order of metamorphic mobility) in 22 Antarctic unequilibrated ordinary chondrites (UOC). This brings to 38 the number of UOC for which data for highly volatile elements are known. For elements of lesser mobility (Co to Se, omitting Cs) overall variability in UOC are low, relative standard deviations (one sigma) being no more than a factor of two. For Ag, Te and Zn, relative standard deviations are 2-4×, while for Cs and the four most volatile elements, the variabilities are 8-110×. Elemental abundances do not vary with chemical type (H, L and LL) nor with UOC subtype (3.0-3.9). Contents of all elements reach levels up to, even exceeding, cosmic and all but Cd and the two alkalis, seem unaffected by post-accretionary processes. Contents of highly volatile elements are consistent with the idea that source regions producing contemporary falls and older Antarctic UOC differed in thermal histories. The presence or absence of carbide magnetite assemblages (CMA) generally accords with high or low Cd contents, respectively. This relationship accords with the prior suggestion that CMA formed by alteration of Fe-Ni metal by C-O-H-containing fluids at temperatures indicate that they were subsequently destroyed as metamorphic intensity increased. The high, often supercosmic, Rb and Cs levels in UOC may result from their high solubility in liquid water signalling their redistribution by C-O-H-containing fluid while in the liquid water field. Because of its uniquely high mobility, Cd could have been enriched by the C-O-H fluids and should have been lost from parent regions during later, higher temperature anhydrous metamorphism at temperatures in the 500-600 °C range.

  3. Hybridization of Single Nanocrystals of Cs4PbBr6 and CsPbBr3

    OpenAIRE

    Weerd, Chris de; Lin, Junhao; Gomez, Leyre; Fujiwara, Yasufumi; Suenaga, Kazutomo; Gregorkiewicz, Tom

    2017-01-01

    Nanocrystals of all-inorganic cesium lead halide perovskites (CsPbX3, X = Cl, Br, I) feature high absorption and efficient narrow-band emission which renders them promising for future generation of photovoltaic and optoelectronic devices. Colloidal ensembles of these nanocrystals can be conveniently prepared by chemical synthesis. However, in the case of CsPbBr3, its synthesis can also yield nanocrystals of Cs4PbBr6 and the properties of the two are easily confused. Here, we investigate in de...

  4. Effect of Silicon on Activity Coefficients of P, Bl, CD, SN, and AG in Liquid Fe-Si, and Implications for Differentiation and Core Formation

    Science.gov (United States)

    Righter, K.; Pando, K.; Ross, D. K.

    2017-01-01

    Cores of differentiated bodies (Earth, Mars, Mercury, Moon, Vesta) contain light elements such as S, C, Si, and O. We have previously measured small effects of Si on metal-silicate partitioning of Ni and Co [1,2], and larger effects for Mo, Ge, Sb, As [2]. The effect of Si on many siderophile elements could be an important, and as yet unquantified, influence on the core-mantle partitioning of SE. Here we report new experiments designed to quantify the effect of Si on the partitioning of Bi, Cd, Sn, Ag, and P between metal and silicate melt. The results will be applied to Earth, Mars, Mercury, Moon, and Vesta, for which we have excellent constraints on the mantle Bi, Cd, Sn, Ag, and P concentrations from mantle and/or basalt samples.

  5. Behaviour of 134Cs in the aquatic ecosystems

    International Nuclear Information System (INIS)

    Xu Yinliang; Chen Chuanqun

    1992-07-01

    The diminution of 134 Cs in the aquatic phases and the absorption of 134 Cs by aquatic lives observe the exponential expression. i.e. Y Ae be . The relationships between the enrichment factor of 134 Cs(K) and the time(t) in the aquatic lives can be represented by a linear equation, K A + Bt. The value of K in the Alternanthera philoxeroides was about 560. That can be used for monitoring and purifying the water phase contaminated by 134 Cs. Fish can absorb 134 Cs from water phase and store it in liver and kidney. The specific activity of 134 Cs in fish flesh was low but the percentage of radioactivity was high that was about 30% of total radioactivity in the fish. River mud can strongly absorb 134 Cs and reduce the absorption by aquatic lives. It is a good adsorbent and purifying agent with low cost for treatment of 134 Cs. The K + can prevent aquatic lives from absorbing Cs + because of antagonistic function

  6. Volatile and siderophile trace elements in anorthositic rocks from Fiskenaesset, West Greenland: comparison with lunar and meteoritic analogues

    International Nuclear Information System (INIS)

    Morgan, J.W.; Ganapathy, R.; Higuchi, H.; Kraehenbuehl, U.

    1976-01-01

    Seventeen trace elements (Ag, Au, Bi, Br, Cd, Cs, Ge, Ir, Ni, Rb, Re, Sb, Se, Te, Tl, U, Zn) were analysed by radiochemical neutron activation and 13 other elements (Ce, Co, Cr, Eu, Fe, Hf, La, Lu, Na, Sc, Sm, Tb, Yb) by instrumental neutron activation in a total of 12 rocks from the layered anorthositic complex at Fiskenaesset, West Greenland, and in the plagioclase-rich unbrecciated eucrite, Serra de Mage. The results are discussed and compared with lunar and meteoritic analogues. (author)

  7. New technology of CRDM-CS

    International Nuclear Information System (INIS)

    Yasushi Nozaki; Hiroyuki Ukon; Toshiaki Matsumura; Yoshihiro Sakurai; Sigenori Hatazawa; Hitoshi Yamagishi; Katsuji Kaneizumi; Hisashi Yasuda

    2005-01-01

    Control Rod Drive Mechanism Control System (CRDM-CS) for PWR Nuclear Power Plant was developed as a domestic product in 1975 and it has been applied to the commercial power plants. Since then, the CRDM-CS has been continuously improved through applying a double-hold-system, an intensified monitoring system, etc. As the result of these modifications unexpected rod drops have never occurred more than ten years in Japanese PWR plants. The system is still so high reliable, however, the technologies of employed devices are old-fashioned and we face on the difficulty to keep spare-parts these days. On the other hand, there are new movements to seek after the plant life extension of 60 years. These situations require a modernized CRDM-CS to accomplish the reliability in accordance to the plant life extension. to comply the above-mentioned object we developed a new CRDM-CS applied with following technologies; 1) Digitalized logic cabinet, 2) I.G.B.T in the main circuit of power cabinet, 3) Standardized cabinet by employing the unit structure, 4) Unnecessary DC hold power cabinet. These measures can play an important role in cost cutting and space reduction in replacing CRDM-CS. The concepts in developing the new CRDM-CS, the applied technologies to the power cabinet, the system structure and characteristics of the logic cabinet and the outline of verification test and result are discussed in this paper. (authors)

  8. Coefficients of distribution and accumulation of K, Rb, Cs and 137Cs in the intensive poultry breeding cycle

    International Nuclear Information System (INIS)

    Djuric, G.; Ajdacic, N.; Institut za Nuklearne Nauke Boris Kidric, Belgrade

    1984-01-01

    The concentration of K,Rb,Cs and the activity level of Cs-137 in samples from the intensive poultry breeding cycle (feed, meat, eggs), under the condition of chronic alimentary contamination is presented. Concentrations of Cs and Rb were determined by non-destructive neutron activation analysis, concentration of K by atomic absorption flame photometry and activity of Cs-137 by gamma spectrometric analysis. On the basis of these results, coefficients of distribution and accumulation were calculated. The distribution coefficients of the analysed stable isotopes in meat have values close to 1, whereas for various parts of egg these coefficients vary between 0.5 and 1.5. Significant differences in Cs-137 distribution in various parts of egg were established. The values of accumulation coefficients indicate that all analysed elements selectively accumulate in the meat of young birds (broilers), and Cs-137 accumulates in the egg white as well. (orig.)

  9. Bioaccumulation and elimination of 60 Co and 137 Cs by Anomalocardia brasiliana (Gmelin, 1791) (Mollusca bivalvia). Remobilization of 60 Co, retained in marine sediment by microbial activity

    International Nuclear Information System (INIS)

    Mayr, L.M.

    1984-05-01

    It was studied the capacity of a bi valve mollusc Anomalocardia brasiliana, which lives in the local bottom sediment, to remobilize 60 Co previously sorbed in the sediment. Laboratory experiments demonstrated that the transference of 60 Co from the sediment to the animal was insignificant (bioaccumulation factor (BF) of the order of 10 -3 ). At the same time, the capacity of microorganisms, present in the bottom sediment, to remobilize 60 Co was studied. The results showed that this via of transference was important, considering the much greater microorganism biomass in relation to the biomass of bentonic organisms, as a whole. For 137 Cs the determined BF from water to the animal was 2.2. and, as in the case of 60 Co, the soft tissues concentrated more 137 Cs than shell. Remaining viscera showed the highest BFs. In another series of experiments, the loss of 60 Co or 137 Cs, previously accumulated by A. brasiliana, was followed in aquaria with or without sediment and the respective biological half-lives were calculated. Soft tissues retained 60 Co longer (biological half-life = 117 days) than shells, whereas for 137 Cs the opposite was observed and shells showed a biological half life of 38.5 days. The low values of 60 Co and 137 Cs BF S do not allow to classify A. brasiliana as good biological indicator for pollution by there radionuclides. However since A brasiliana is consumed by the local population and is commercialized to other areas, it was recommended that its contamination by 60 Co or 137 Cs should be monitored. (author)

  10. Using Multiple Paths in NoCs for Guaranteed Resource Allocation and Improved Best Effort Performance in NoCs.

    NARCIS (Netherlands)

    Ovadia, I.; Ha, Y.; Corporaal, H.

    2005-01-01

    Networks-on-Chips (NoCs) provide communication platforms to Systems-on-Chips (SoCs). In NoCs, channels are generally shared between traffic flows, resulting in contention. However, certain flows require delivery guarantees. Differentiated quality-of-service (QoS) is achieved by providing guaranteed

  11. Changes in fatty acid content and composition between wild type and CsHMA3 overexpressing Camelina sativa under heavy-metal stress.

    Science.gov (United States)

    Park, Won; Feng, Yufeng; Kim, Hyojin; Suh, Mi Chung; Ahn, Sung-Ju

    2015-09-01

    Under heavy-metal stress, CsHMA3 overexpressing transgenic Camelina plants displayed not only a better quality, but also a higher quantity of unsaturated fatty acids in their seeds compared with wild type. Camelina sativa L. belongs to the Brassicaceae family and is frequently used as a natural vegetable oil source, as its seeds contain a high content of fatty acids. In this study, we observed that, when subjected to heavy metals (Cd, Co, Zn and Pb), the seeds of CsHMA3 (Heavy-Metal P1B-ATPase 3) transgenic lines retained their original golden yellow color and smooth outline, unlike wild-type seeds. Furthermore, we investigated the fatty acids content and composition of wild type and CsHMA3 transgenic lines after heavy metal treatments compared to the control. The results showed higher total fatty acid amounts in seeds of CsHMA3 transgenic lines compared with those in wild-type seeds under heavy-metal stresses. In addition, the compositions of unsaturated fatty acids-especially 18:1 (oleic acid), 18:2 (linoleic acid; only in case of Co treatment), 18:3 (linolenic acid) and 20:1 (eicosenoic acid)-in CsHMA3 overexpressing transgenic lines treated with heavy metals were higher than those of wild-type seeds under the same conditions. Furthermore, reactive oxygen species (ROS) contents in wild-type leaves and roots when treated with heavy metal were higher than in CsHMA3 overexpressing transgenic lines. These results indicate that overexpression of CsHMA3 affects fatty acid composition and content-factors that are responsible for the fuel properties of biodiesel-and can alleviate ROS accumulation caused by heavy-metal stresses in Camelina. Due to these factors, we propose that CsHMA3 transgenic Camelina can be used for phytoremediation of metal-contaminated soil as well as for oil production.

  12. Modeling radionuclide Cs and C dynamics in an artificial forest ecosystem in Japan -FoRothCs ver1.0-

    Directory of Open Access Journals (Sweden)

    Kazuya eNishina

    2015-09-01

    Full Text Available Predicting the environmental fate of Cs radionuclides in forest ecosystems is important for the effective management and assessment of radioactively contaminated forest areas. A large proportion of the radioactively contaminated areas in Japan consist of forest ecosystems, and most of these areas are artificial forests that are used for timber production (e.g., Japanese cedar (Cryptomeria japonica and red pine (Pinus densiflora. Determining the long-term redistribution of 137Cs in forest ecosystems is important for estimating human doses and understanding the ecological impacts and challenges associated with managing contaminated forests. To facilitate the management and 137Cs decontamination of these forests, we developed a new open-source 137Cs cycling model, ForRothCs, that considers C cycling within forests, as well as biomass production and soil decomposition processes. For the 137Cs inventory, this model estimates the dynamics (Bq m−2 and activity (Bq kg−2 of 137Cs on a decadal time scale, primarily in the leaves, branches, stems, litter layer, and the soil. This model is based on the biomass production and the dynamics of the C cycle models. We tested the model by considering a simple scenario of forest management, i.e., thinning and harvesting, for the first five years following a fallout event. The results showed that these activities have a limited impact on the 137Cs inventory due to the rapid migration of 137Cs from vegetation to soil. Our projections also showed the examined forest management practices resulted in reduced litterfall, which in turn reduced C input to the forest floor and increased the concentration of 137Cs in the litterfall and soil organic layer. Although further validation of the ForRothCs model is required using field observation data, the model can be used to evaluate long-term 137Cs dynamics associated with commonly used forest and decontamination management scenarios.

  13. Luminescent CsPbI.sub.3./sub. and Cs.sub.4./sub.PbI.sub.6./sub. aggregates in annealed CsI:Pb crystals

    Czech Academy of Sciences Publication Activity Database

    Babin, V.; Fabeni, P.; Nikl, Martin; Nitsch, Karel; Pazzi, G.P.; Zazubovich, S.

    2001-01-01

    Roč. 226, č. 2 (2001), s. 419-428 ISSN 0370-1972 Institutional research plan: CEZ:AV0Z1010914 Keywords : CsPbI 3 * Cs 4 PbI 6 * nanoaggregates * luminescence Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.873, year: 2001

  14. DFT study on the interfacial properties of vertical and in-plane BiOI/BiOIO3 hetero-structures.

    Science.gov (United States)

    Dai, Wen-Wu; Zhao, Zong-Yan

    2017-04-12

    Composite photocatalysts with hetero-structures usually favor the effective separation of photo-generated carriers. In this study, BiOIO 3 was chosen to form a hetero-structure with BiOI, due to its internal polar field and good lattice matching with BiOI. The interfacial properties and band offsets were focused on and analyzed in detail by DFT calculations. The results show that the charge depletion and accumulation mainly occur in the region near the interface. This effect leads to an interfacial electric field and thus, the photo-generated electron-hole pairs can be easily separated and transferred along opposite directions at the interface, which is significant for the enhancement of the photocatalytic activity. Moreover, according to the analysis of band offsets, the vertical BiOI/BiOIO 3 belongs to the type-II hetero-structure, while the in-plane BiOI/BiOIO 3 belongs to the type-I hetero-structure. The former type of hetero-structure has more favorable effects to enhance the photocatalytic activity of BiOI than that of the latter type of hetero-structure. In the case of the vertical BiOI/BiOIO 3 hetero-structure, photo-generated electrons can move from the conduction band of BiOI to that of BiOIO 3 , while holes can move from the valence band of BiOIO 3 to that of BiOI under solar radiation. In addition, the introduced internal electric field functions as a selector that can promote the separation of photo-generated carriers, resulting in the higher photocatalytic quantum efficiency. These findings illustrate the underlying mechanism for the reported experiments, and can be used as a basis for the design of novel highly efficient composite photocatalysts with hetero-structures.

  15. Sensitive bi-enzymatic biosensor based on polyphenoloxidases-gold nanoparticles-chitosan hybrid film-graphene doped carbon paste electrode for carbamates detection.

    Science.gov (United States)

    Oliveira, Thiago M B F; Barroso, M Fátima; Morais, Simone; Araújo, Mariana; Freire, Cristina; de Lima-Neto, Pedro; Correia, Adriana N; Oliveira, Maria B P P; Delerue-Matos, Cristina

    2014-08-01

    A bi-enzymatic biosensor (LACC-TYR-AuNPs-CS/GPE) for carbamates was prepared in a single step by electrodeposition of a hybrid film onto a graphene doped carbon paste electrode (GPE). Graphene and the gold nanoparticles (AuNPs) were morphologically characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, dynamic light scattering and laser Doppler velocimetry. The electrodeposited hybrid film was composed of laccase (LACC), tyrosinase (TYR) and AuNPs entrapped in a chitosan (CS) polymeric matrix. Experimental parameters, namely graphene redox state, AuNPs:CS ratio, enzymes concentration, pH and inhibition time were evaluated. LACC-TYR-AuNPs-CS/GPE exhibited an improved Michaelis-Menten kinetic constant (26.9±0.5M) when compared with LACC-AuNPs-CS/GPE (37.8±0.2M) and TYR-AuNPs-CS/GPE (52.3±0.4M). Using 4-aminophenol as substrate at pH5.5, the device presented wide linear ranges, low detection limits (1.68×10(-9)±1.18×10(-10)-2.15×10(-7)±3.41×10(-9)M), high accuracy, sensitivity (1.13×10(6)±8.11×10(4)-2.19×10(8)±2.51×10(7)%inhibitionM(-1)), repeatability (1.2-5.8% RSD), reproducibility (3.2-6.5% RSD) and stability (ca. twenty days) to determine carbaryl, formetanate hydrochloride, propoxur and ziram in citrus fruits based on their inhibitory capacity on the polyphenoloxidases activity. Recoveries at two fortified levels ranged from 93.8±0.3% (lemon) to 97.8±0.3% (orange). Glucose, citric acid and ascorbic acid do not interfere significantly in the electroanalysis. The proposed electroanalytical procedure can be a promising tool for food safety control. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Cs2UPd3Se6

    Directory of Open Access Journals (Sweden)

    George N. Oh

    2011-02-01

    Full Text Available Dicaesium uranium(IV tripalladium(II hexaselenide, Cs2UPd3Se6, crystallizes in the space group Fmmm in the Ba2NaCu3O6 structure type. The asymmetric unit comprises the following atoms with site symmetries as shown: U1 (mm2, Cs1 (222, Cs2 (m2m, Pd1 (.m., Pd2 (2mm, Se1 (m.., and Se2 (1. This layered structure contains six edge-sharing square-planar [PdSe4] units that form a hexagon. These, in turn, edge-share with [USe6] trigonal–prismatic units, forming an extended layer parallel to (010. The layers are stacked along [010]. They are staggered, and are separated by the Cs atoms. The Cs atoms are either coordinated in a square antiprism of Se atoms or are ten-coordinate, with one square face and the opposite face hexagonal.

  17. Strongly compressed Bi (111) bilayer films on Bi{sub 2}Se{sub 3} studied by scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, K. F.; Yang, Fang; Song, Y. R. [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Liu, Canhua; Qian, Dong; Gao, C. L.; Jia, Jin-Feng [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093 (China)

    2015-09-21

    Ultra-thin Bi films show exotic electronic structure and novel quantum effects, especially the widely studied Bi (111) film. Using reflection high-energy electron diffraction and scanning tunneling microscopy, we studied the structure and morphology evolution of Bi (111) thin films grown on Bi{sub 2}Se{sub 3}. A strongly compressed, but quickly released in-plane lattice of Bi (111) is found in the first three bilayers. The first bilayer of Bi shows a fractal growth mode with flat surface, while the second and third bilayer show a periodic buckling due to the strong compression of the in-plane lattice. The lattice slowly changes to its bulk value with further deposition of Bi.

  18. Exceptional magneto-resistance in 3D Dirac semimetal Bi0.96Sb0.04

    Science.gov (United States)

    Kumar, P.; Nagpal, V.; Sudesh, Patnaik, S.

    2017-05-01

    Recent experimental evidence for Weyl fermions in topological semimetals has attracted considerable attention. These materials are three-dimensional analogue of graphene. The present work is motivated by the recent prediction of Weyl semi-metallic phase in Bi1-xSbx alloys. In this paper we present the electronic transport properties studied under high applied magnetic fields in Bi0.96Sb0.04 alloys. The sample exhibits extremely high magneto-resistance; MR(5 K, 8 T) = 9.8×104 %. This value is comparable to the MR observed in recently discovered other members of these emergent materials. Most importantly, this composition shows large MR at room temperature, MR (300 K, 8 T) = 435%, which is almost twice to that observed in Dirac semimetal Cd3As2 (= 200 % at 14.5 T) and Weyl semimetal NbP (= 250% at 9 T). We also discuss single crystal growth technique as well as Hall measurement data.

  19. An ion exchange strategy to BiOI/CH{sub 3}COO(BiO) heterojunction with enhanced visible-light photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Han, Qiaofeng, E-mail: hanqiaofeng@njust.edu.cn; Yang, Zhen; Wang, Li; Shen, Zichen; Wang, Xin; Zhu, Junwu; Jiang, Xiaohong

    2017-05-01

    Highlights: • BiOI/BiOAc heterojunction was firstly synthesized by an ion exchange route. • BiOI/BiOAc exhibited enhanced visible-light-driven photoreactivity for the dyes degradation in comparison with individuals. • Photocatalytic activity of the as-prepared BiOI/BiOAc is better than that prepared by precipitation-deposition method. • Photosensitization effect of BiOI to BiOAc was superior to that of Bi{sub 2}S{sub 3} due to suitable solubility constant. - Abstract: It is very significant to develop CH{sub 3}COO(BiO) (denoted as BiOAc) based photocatalysts for the removal of pollutants due to its non-toxicity and availability. We previously reported that BiOAc exhibited excellent photocatalytic activity for rhodamine B (RhB) degradation under UV light irradiation. Herein, by an ion exchange approach, BiOI/BiOAc heterojunction could be easily obtained. The as-prepared heterojunction possessed enhanced photodegradation activity for multiple dyes including RhB and methyl orange (MO) under visible light illumination in comparison with individual materials. Good visible-light photocatalytic activity of the heterojunction could be attributed to the increased visible light response, effective charge transfer from the modified band position and close interfacial contact due to partial ion exchange method.

  20. Synthesis of chemically bonded BiOCl@Bi{sub 2}WO{sub 6} microspheres with exposed (0 2 0) Bi{sub 2}WO{sub 6} facets and their enhanced photocatalytic activities under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yongchao [Qingdao Agricultural University, Qingdao 266109 (China); Chen, Zhiwei [School of Life Sciences, Shandong University of Technology, Zibo 255049 (China); Qu, Dan [Qingdao Agricultural University, Qingdao 266109 (China); Shi, Jinsheng, E-mail: jsshiqn@aliyun.com [Qingdao Agricultural University, Qingdao 266109 (China)

    2016-01-15

    Graphical abstract: - Highlights: • BiOCl@Bi{sub 2}WO{sub 6} composites were prepared via a controlled anion exchange method. • The shell of composites was composed of Bi{sub 2}WO{sub 6} sheets with exposed (0 2 0) facets. • The BiOCl@Bi{sub 2}WO{sub 6} composites showed efficient photocatalytic activity. • A possible photocatalytic degradation mechanism is proposed. - Abstract: Bi{sub 2}WO{sub 6} photocatalysts has been extensively studied for its photocatalytic activity. However, few works have been conducted on hierarchical Bi{sub 2}WO{sub 6} composite photocatalysts with specifically exposed facets. In this work, we report a facile method to synthesize BiOCl@Bi{sub 2}WO{sub 6} hierarchical composite microspheres. Bi{sub 2}WO{sub 6} nanosheets with specifically exposed (0 2 0) facet were directly formed on the surface of BiOCl precursor microspheres via a controlled anion exchange route between BiOCl and Na{sub 2}WO{sub 4}. The visible-light photocatalytic activity of the BiOCl@Bi{sub 2}WO{sub 6} heterojunction with exposed (0 2 0) facets (denoted as BiOCl@Bi{sub 2}WO{sub 6}) was investigated by degradation of Rhodamine B (RhB) and ciprofloxacin (CIP) aqueous solution under visible light irradiation. The experimental results indicated that the BiOCl@Bi{sub 2}WO{sub 6} composite microsphere with intimate interfacial contacts exhibited improved efficiency for RhB photodegradation in comparison with pure BiOCl and Bi{sub 2}WO{sub 6}. The BiOCl@Bi{sub 2}WO{sub 6} composite microsphere also shows high photocatalytic activity for degradation of CIP under visible light irradiation. The enhanced photocatalytic performance of BiOCl@Bi{sub 2}WO{sub 6}-020 hierarchical microspheres can be ascribed to the improved visible light harvesting ability, high charge separation and transfer. This work will make significant contributions toward the exploration of novel heterostructures with high potential in photocatalytic applications.

  1. Local variation in Bi crystal sites of epitaxial GaAsBi studied by photoelectron spectroscopy and first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Laukkanen, P., E-mail: pekka.laukkanen@utu.fi [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Punkkinen, M.P.J., E-mail: marko.punkkinen@utu.fi [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Lahti, A. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Puustinen, J. [Optoelectronics Research Centre, Tampere University of Technology, FI-33101 Tampere (Finland); Tuominen, M. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Hilska, J. [Optoelectronics Research Centre, Tampere University of Technology, FI-33101 Tampere (Finland); Mäkelä, J.; Dahl, J.; Yasir, M. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Kuzmin, M. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Ioffe Physical-Technical Institute, Russian Academy of Sciences, St. Petersburg 194021, Russian Federation (Russian Federation); Osiecki, J.R.; Schulte, K. [The MAX IV laboratory, P. O. Box 118, Lund University, SE-221 00 Lund (Sweden); Guina, M. [Optoelectronics Research Centre, Tampere University of Technology, FI-33101 Tampere (Finland); Kokko, K. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland)

    2017-02-28

    Highlights: • XPS is used to study bulk-like properties of GaAsBi crystals. • Surface effects are removed from XPS signal by an epitaxial AlAs cap film. • Local variation of Bi composition is found. • The result is consistent with photoluminescence and theoretical results. • Ga vacancies and Bi crystallites are suggested to be dominating defects. - Abstract: Epitaxial Bi-containing III–V crystals (III-V{sub 1-x}Bi{sub x}) have attracted increasing interest due to their potential in infrared applications. Atomic-scale characterization and engineering of bulk-like III-V{sub 1-x}Bi{sub x} properties (e.g., Bi incorporation and defect formation) are challenging but relevant to develop applications. Toward that target, we report here that the traditional surface-science measurement of photoelectron spectroscopy (PES) is a potential, non-destructive method to be combined in the studies of bulk-like properties, when surface effects are properly removed. We have investigated epitaxial GaAs{sub 1-x}Bi{sub x} films, capped by epitaxial AlAs layers, with high-resolution photoelectron spectroscopy. The Bi5d core-level spectra of GaAs{sub 1-x}Bi{sub x} together with ab-initio calculations give direct evidence of variation of Bi bonding environment in the lattice sites. The result agrees with photoluminescence (PL) measurement which shows that the studied GaAs{sub 1-x}Bi{sub x} films include local areas with higher Bi content, which contribute to PL but do not readily appear in x-ray diffraction (XRD). The measured and calculated Bi core-level shifts show also that Ga vacancies and Bi clusters are dominant defects.

  2. Properties of Cs-intercalated single wall carbon nanotubes investigated by 133Cs Nuclear Magnetic resonance

    KAUST Repository

    Schmid, Marc R.; Mahfouz, Remi; Bouhrara, Mohamed; Saih, Youssef; Mehring, Michael; Basset, Jean-Marie; Goze-Bac, Christophe; Abou-Hamad, Edy

    2012-01-01

    present within the carbon nanotube bundles. At high concentrations, the Cs (β)+ ions seem to occupy well defined positions relative to the carbon lattice. As a matter of fact, the Korringa relaxation behavior suggests a strong hyperfine coupling between Cs

  3. Potential value of Cs-137 capsules

    Energy Technology Data Exchange (ETDEWEB)

    Bloomster, C.H.; Brown, D.R.; Bruno, G.A.; Hazelton, R.F.; Hendrickson, P.L.; Lezberg, A.J.; Tingey, G.L.; Wilfert, G.L.

    1985-04-01

    We determined the value of Cs-137 compared to Co-60 as a source for the irradiation of fruit (apples and cherries), pork and medical supplies. Cs-137, in the WESF capsule form, had a value of approximately $0.40/Ci as a substitute for Co-60 priced at approximately $1.00/Ci. The comparison was based on the available curies emitted from the surface of each capsule. We developed preliminary designs for fourteen irradiation facilities; seven were based on Co-60 and seven were based on Cs-137. These designs provided the basis for estimating capital and operating costs which, in turn, provided the basis for determining the value of Cs-137 relative to Co-60 in these applications. We evaluated the effect of the size of the irradiation facility on the value of Cs-137. The cost of irradiation is low compared to the value of the product. Irradiation of apples for disinfestation costs $.01 to .02 per pound. Irradiation for trichina-safe pork costs $.02 per pound. Irradiation of medical supplies for sterilization costs $.07 to .12 per pound. The cost of the irradiation source, either Co-60 or Cs-137, contributed only a minor amount to the total cost of irradiation, about 5% for the fruit and hog cases and about 20% for the medical supply cases. We analyzed the sensitivity of the irradiation costs and Cs-137 value to several key assumptions.

  4. Potential value of Cs-137 capsules

    International Nuclear Information System (INIS)

    Bloomster, C.H.; Brown, D.R.; Bruno, G.A.; Hazelton, R.F.; Hendrickson, P.L.; Lezberg, A.J.; Tingey, G.L.; Wilfert, G.L.

    1985-04-01

    We determined the value of Cs-137 compared to Co-60 as a source for the irradiation of fruit (apples and cherries), pork and medical supplies. Cs-137, in the WESF capsule form, had a value of approximately $0.40/Ci as a substitute for Co-60 priced at approximately $1.00/Ci. The comparison was based on the available curies emitted from the surface of each capsule. We developed preliminary designs for fourteen irradiation facilities; seven were based on Co-60 and seven were based on Cs-137. These designs provided the basis for estimating capital and operating costs which, in turn, provided the basis for determining the value of Cs-137 relative to Co-60 in these applications. We evaluated the effect of the size of the irradiation facility on the value of Cs-137. The cost of irradiation is low compared to the value of the product. Irradiation of apples for disinfestation costs $.01 to .02 per pound. Irradiation for trichina-safe pork costs $.02 per pound. Irradiation of medical supplies for sterilization costs $.07 to .12 per pound. The cost of the irradiation source, either Co-60 or Cs-137, contributed only a minor amount to the total cost of irradiation, about 5% for the fruit and hog cases and about 20% for the medical supply cases. We analyzed the sensitivity of the irradiation costs and Cs-137 value to several key assumptions

  5. Calorimetric investigations of U-Bi system

    International Nuclear Information System (INIS)

    Agarwal, Renu; Joshi, A.R.

    2013-01-01

    U 0.333 Bi 0.667 is a compound that may form on breach of clad during reactor operation with metallic fuel and lead-bismuth coolant. Therefore, enthalpy of mixing of U-Bi liquid solution in limited composition range and enthalpy of formation of U 0.333 Bi 0.667 compound were measured by high temperature calorimetry. The enthalpy of mixing follows subregular solution model and enthalpy of formation U 0.333 Bi 0.667 from U(l) and Bi(l) at 843 K was -52.5 kJ/mol and -40.8 kJ/mol from U(s) and Bi(s) at 298.15 K. Both enthalpy of mixing and enthalpy of formation of intermetallic compound obtained experimentally were compared with Miedema model values. (author)

  6. Prospects of In/CdTe X- and γ-ray detectors with MoO Ohmic contacts

    Science.gov (United States)

    Maslyanchuk, Olena L.; Solovan, Mykhailo M.; Maistruk, Eduard V.; Brus, Viktor V.; Maryanchuk, Pavlo D.; Gnatyuk, Volodymyr A.; Aoki, Toru

    2018-01-01

    The present paper analyzes the charge transport mechanisms and spectrometric properties of In/CdTe/MoOx heterojunctions prepared by magnetron sputtering of indium and molybdenum oxide thin films onto semi-insulating p-type single-crystal CdTe semiconductor, produced by Acrorad Co. Ltd. Current-voltage characteristics of the detectors at different temperatures were investigated. The charge transport mechanisms in the heterostructures under investigation were determined: the generation-recombination in the space charge region (SCR) at relatively low voltages and the space charge limited currents at high voltages. The spectra of 137Cs and 241Am isotopes taken at different applied bias voltages are presented. It is shown that the In/CdTe/MoOx structures can be used as X/γ-ray detectors in the spectrometric mode.

  7. Exploratory Bi-factor Analysis: The Oblique Case

    OpenAIRE

    Jennrich, Robert L.; Bentler, Peter M.

    2011-01-01

    Bi-factor analysis is a form of confirmatory factor analysis originally introduced by Holzinger and Swineford (1937). The bi-factor model has a general factor, a number of group factors, and an explicit bi-factor structure. Jennrich and Bentler (2011) introduced an exploratory form of bi-factor analysis that does not require one to provide an explicit bi-factor structure a priori. They use exploratory factor analysis and a bi-factor rotation criterion designed to produce a rotated loading mat...

  8. Water culture of the rice containing Cs-137

    International Nuclear Information System (INIS)

    Choi, Yong Ho; Keum, Dong Kwon; Lim, Kwang Muk; Jun, In; Park, Doo Won

    2008-10-01

    Pot experiments were carried out in a greenhouse in order to produce Cs-137-containing rice seeds as a source material for use in manufacturing reference rice samples of a high Cs-137 activity. Two kinds of soil were used and two pots were prepared for each kind of soil. Rice plants were water-cultured in the pots and Cs-137 was applied to the surface water to induce a Cs-137 contamination of rice seeds via a plant uptake of Cs-137. Mature rice plants were harvested and Cs-137-containing rice seeds were obtained after some treatment of the harvested plants. These produced rice seeds are going to be provided for the KRISS so as to be used in manufacturing reference rice samples for Cs-137

  9. Thermal, conductivity, NMR, and Raman spectroscopic measurements and phase diagram of the Cs2S2O7-CsHSO4 system

    DEFF Research Database (Denmark)

    Rasmussen, Søren Birk; Hama, Hind; Lapina, Olga

    2003-01-01

    The conductivity of the binary system CS2S2O7-CsHSO4 has been measured at 20 different molten compositions in the full composition range and in the temperature range 430-750 K. From the obtained liquidus-solidus phase transition temperatures, the phase diagram has been constructed. It is of the s......The conductivity of the binary system CS2S2O7-CsHSO4 has been measured at 20 different molten compositions in the full composition range and in the temperature range 430-750 K. From the obtained liquidus-solidus phase transition temperatures, the phase diagram has been constructed...... from the NMR measurements on CsHSO4, CS2S2O7, and Cs2S2O7-CsHSO4 mixtures. For 11 selected compositions covering the entire composition range of the CS2S2O7-CsHSO4 binary system, the conductivity of the molten state has been expressed by equations of the form k(X) = A(X) + B(X)(T - T-m) + C(X)(T - T...

  10. Alkali metal bismuth(III) chloride double salts

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Andrew W. [Department of Chemistry, College of William and Mary, Williamsburg, VA 23187 (United States); Nicholas, Aaron; Ahern, John C. [Department of Chemistry, University of Maine, Orono, ME 04469 (United States); Chan, Benny [Department of Chemistry, College of New Jersey, Ewing, NJ 08628-0718 (United States); Patterson, Howard H. [Department of Chemistry, University of Maine, Orono, ME 04469 (United States); Pike, Robert D., E-mail: rdpike@wm.edu [Department of Chemistry, College of William and Mary, Williamsburg, VA 23187 (United States)

    2016-06-15

    Evaporative co-crystallization of MCl (M = Na, K, Rb, Cs) with BiOCl in aqueous HCl produces double salts: M{sub x}Bi{sub y}Cl{sub (x+3y)}·zH{sub 2}O. The sodium salt, Na{sub 2}BiCl{sub 5}·5H{sub 2}O (monoclinic P2{sub 1}/c, a = 8.6983(7) Å, b = 21.7779(17) Å, c = 7.1831(6) Å, β = 103.0540(10)°, V = 1325.54(19) Å{sup 3}, Z = 4) is composed of zigzag chains of μ{sub 2}-Cl-cis-linked (BiCl{sub 5}){sub n}{sup 2n–} chains. Edge-sharing chains of NaCl{sub n}(OH{sub 2}){sub 6−n} octahedra (n = 0, 2, 3) are linked through μ{sub 3}-Cl to Bi. The potassium salt, K{sub 7}Bi{sub 3}Cl{sub 16} (trigonal R−3c, a = 12.7053(9) Å, b = 12.7053(9) Å, c = 99.794(7) Å, V = 13,951(2) Å{sup 3}, Z = 18) contains (Bi{sub 2}Cl{sub 10}){sup 4–} edge-sharing dimers of octahedra and simple (BiCl{sub 6}){sup 3–} octahedra. The K{sup +} ions are 5- to 8-coordinate and the chlorides are 3-, 4-, or 5-coordinate. The rubidium salt, Rb{sub 3}BiCl{sub 6}·0.5H{sub 2}O (orthorhombic Pnma, a = 12.6778(10) Å, b = 25.326(2) Å, c = 8.1498(7) Å, V = 2616.8(4) Å{sup 3}, Z = 8) contains (BiCl{sub 6}){sup 3–} octahedra. The Rb{sup +} ions are 6-, 8-, and 9-coordinate, and the chlorides are 4- or 5-coordinate. Two cesium salts were formed: Cs{sub 3}BiCl{sub 6} (orthorhombic Pbcm, a = 8.2463(9) Å, b = 12.9980(15) Å, c = 26.481(3) Å, V = 2838.4(6) Å{sup 3}, Z = 8) being comprised of (BiCl{sub 6}){sup 3–} octahedra, 8-coordinate Cs{sup +}, and 3-, 4-, and 5-coordinate Cl{sup −}. In Cs{sub 3}Bi{sub 2}Cl{sub 9} (orthorhombic Pnma, a = 18.4615(15) Å, b = 7.5752(6) Å, c = 13.0807(11) Å, V = 1818.87(11) Å{sup 3}, Z = 4) Bi octahedra are linked by μ{sub 2}-bridged Cl into edge-sharing Bi{sub 4} squares which form zigzag (Bi{sub 2}Cl{sub 9}){sub n}{sup 3n–} ladders. The 12-coordinate Cs{sup +} ions bridge the ladders, and the Cl{sup −} ions are 5- and 6-coordinate. Four of the double salts are weakly photoluminescent at 78 K, each showing a series of three excitation peaks

  11. Determination of /sup 131/I, /sup 134/Cs, /sup 137/Cs in grass and cheese after Chernobyl accident in Austria

    Energy Technology Data Exchange (ETDEWEB)

    Teherani, D K

    1987-09-14

    Various samples from Styria (grass) and Salzburg (cheese) were analyzed for /sup 131/I, /sup 134/Cs and /sup 137/Cs concentration during April - July 1986 by ..gamma..-ray spectroscopy. The concentrations are reported in nCi kg/sup -1/ wet weight. The values found for /sup 131/I were 0.2-17.2 (grass), 0.1-0.5 (cheese), for /sup 134/Cs 1.1-6.2 (grass), 0.2-1.3 (cheese), for /sup 137/Cs 1.6-15.7 (grass), 0.3-2.2 (cheese). While radioactivity of /sup 131/I, /sup 134/Cs and /sup 137/Cs in cheese samples increased from May to June, it decreased in grass samples from May to July. (author) 5 refs

  12. Novel Apo E-Derived ABCA1 Agonist Peptide (CS-6253 Promotes Reverse Cholesterol Transport and Induces Formation of preβ-1 HDL In Vitro.

    Directory of Open Access Journals (Sweden)

    Anouar Hafiane

    Full Text Available Apolipoprotein (apo mimetic peptides replicate some aspects of HDL function. We have previously reported the effects of compound ATI-5261 on its ability to replicate many functions of native apo A-I in the process of HDL biogenesis. ATI-5261 induced muscle toxicity in wild type C57Bl/6 mice, increased CPK, ALT and AST and increase in triglyceride (Tg levels. Aromatic phenylalanine residues on the non-polar face of ATI-5261, together with positively charged arginine residues at the lipid-water interface were responsible for these effects. This information was used to create a novel analog (CS-6253 that was non-toxic. We evaluated this peptide designed from the carboxyl terminus of apo E, in its ability to mimic apo A-I functionality. Our data shows that the lipidated particles generated by incubating cells overexpressing ABCA1 with lipid free CS-6253 enhances the rate of ABCA1 lipid efflux with high affinity interactions with native ABCA1 oligomeric forms and plasma membrane micro-domains. Interaction between ABCA1 and lipid free CS-6253 resulted in formation of nascent HDL-CS-6253 particles that are actively remodeled in plasma. Mature HDL-CS-6253 particles deliver cholesterol to liver cells via SR-BI in-vitro. CS-6253 significantly increases cholesterol efflux in murine macrophages and in human THP-1 macrophage-derived foam cells expressing ABCA1. Addition of CS-6253 to plasma dose-dependently displaced apo A-I from α-HDL particles and led to de novo formation of preβ-1 HDL that stimulates ABCA1 dependent cholesterol efflux efficiently. When incubated with human plasma CS-6253 was also found to bind with HDL and LDL and promoted the transfer of cholesterol from HDL to LDL predominantly. Our data shows that CS-6253 mimics apo A-I in its ability to promote ABCA1-mediated formation of nascent HDL particles, and enhances formation of preβ-1 HDL with increase in the cycling of apo A-I between the preβ and α-HDL particles in-vitro. These

  13. G2M arrest and apoptosis in murine T lymphoma cells following exposure to 212Bi alpha particle irradiation

    International Nuclear Information System (INIS)

    Palayoor, S.T.; Humm, J.L.; Macklis, R.M.

    1993-01-01

    Asynchronous exponentially growing EL4 murine T lymphoma cells were exposed either to high LET α-radiation from 212 Bi-DTPA or to γ-radiation from a 137 Cs source. Radiation-induced cell cycle perturbation was studied by flow cytometry. Alpha irradiation, like γ, transiently arrested cells in the G2M phase in a dose-dependent manner. The maximum percentages of cells accumulated in G2M 18 h after α- and γ-irradiation were comparable, though the dose-response relationships differed. The ''RBE'' value for G2M block for α- versus γ-radiation was approx. 4. (author)

  14. Unusual Concentration Induced Antithermal Quenching of the Bi(2+) Emission from Sr2P2O7:Bi(2.).

    Science.gov (United States)

    Li, Liyi; Peng, Mingying; Viana, Bruno; Wang, Jing; Lei, Bingfu; Liu, Yingliang; Zhang, Qinyuan; Qiu, Jianrong

    2015-06-15

    The resistance of a luminescent material to thermal quenching is essential for the application in high power LEDs. Usually, thermal luminescence quenching becomes more and more serious as the activator concentration increases. Conversely, we found here that a red phosphor Sr2P2O7:Bi(2+) is one of the exceptions to this as we studied the luminescence properties at low (10-300 K) and high (300-500 K) temperatures. As Bi(2+) ions are incorporated into Sr2P2O7, they exhibit the emissions at ∼660 and ∼698 nm at room temperature and are encoded, hereafter, as Bi(1) and Bi(2) due to the substitutions for two different crystallographic sites Sr(1) and Sr(2), respectively, in the compound. However, they will not substitute for these sites equally. At lower dopant concentration, they will occupy preferentially Sr(2) sites partially due to size match. As the concentration increases, more Bi(2+) ions start to occupy the Sr(1) sites. This can be verified by the distinct changes of emission intensity ratio of Bi(2) to Bi(1). As environment temperature increases, the thermal quenching happens, but it can be suppressed by the Bi(2+) concentration increase. This becomes even more pronounced in Bi(2+) heavily doped sample as we decompose the broad emission band into separated Bi(1) and Bi(2) Gaussian peaks. For the sample, the Bi(1) emission at ∼660 nm even shows antithermal-quenching particularly at higher temperatures. This phenomenon is accompanied by the blue shift of the overall emission band and almost no changes of lifetimes. A mechanism is proposed due to volume expansion of the unit cell, the increase of Bi(1) content, and temperature dependent energy transfer between Bi(2) and Bi(1). This work helps us better understand the complex luminescent behavior of Bi(2+) doped materials, and it will be helpful to design in the future the heavily doped phosphor for WLEDs with even better resistance to thermal quenching.

  15. Solution-processing of ultra-thin CdTe/ZnO nanocrystal solar cells

    International Nuclear Information System (INIS)

    MacDonald, Brandon I.; Gengenbach, Thomas R.; Watkins, Scott E.; Mulvaney, Paul; Jasieniak, Jacek J.

    2014-01-01

    We have carried out a detailed study into how modifications of the physical, chemical and optical properties of solution-processed, nanocrystalline CdTe layers influence the photovoltaic performance of sintered CdTe/ZnO nanocrystal solar cells. Such solar cells are fabricated through layer-by-layer assembly, which is enabled through an inter layer chemical and thermal treatment cycle. In this manner we are able to fabricate working solar cells with sintered CdTe layers as low as 90 nm, provided that grain size is precisely controlled. We show that the extent of grain growth achieved during the CdTe sintering process is strongly dependent on nanocrystal surface chemistry and chemical environment, with the removal of the organic capping ligands and the introduction of CdCl 2 prior to annealing leading to greatly enhanced growth. Due to the air processing involved and the nanocrystalline nature of the CdTe, the overall performance of these solar cells is shown to be strongly dependent on both annealing temperature and time, with optimal results requiring a balance between crystal growth and degradation due to oxidation. Using this simple bi-layer device structure, optimized treatment conditions result in power conversion efficiencies of up to 7.7% and peak internal quantum efficiencies in excess of 95%. - Highlights: • We study the growth of nanocrystalline CdTe thin films from colloidal nanocrystals. • We examine the CdTe growth profiles as a function of surface chemistry. • We show that nanocrystalline CdTe is susceptible to oxidation under air annealing. • We show how this oxidation influences performance in CdTe/ZnO solar cells. • We demonstrate CdTe/ZnO solar cells with an efficiency of 7.7% fabricated in air

  16. Calculation of inelastic cross sections for H+ + Cs → H(n=2) + Cs+

    International Nuclear Information System (INIS)

    Valance, A.; Spiess, G.

    1975-01-01

    The cross sections for the processes H + +Cs → H(2p and 2s) +Cs + were calculated in the center of mass energy range 250--2400 eV using a simple pseudopotential formalism for the potential curves and coupling matrix elements and a perturbed stationary state (pss) formulation for the calculation of the cross sections. The results are found to be in reasonable agreement with experiment. (auth)

  17. Superior control of HIV-1 replication by CD8+ T cells targeting conserved epitopes: implications for HIV vaccine design.

    Directory of Open Access Journals (Sweden)

    Pratima Kunwar

    Full Text Available A successful HIV vaccine will likely induce both humoral and cell-mediated immunity, however, the enormous diversity of HIV has hampered the development of a vaccine that effectively elicits both arms of the adaptive immune response. To tackle the problem of viral diversity, T cell-based vaccine approaches have focused on two main strategies (i increasing the breadth of vaccine-induced responses or (ii increasing vaccine-induced responses targeting only conserved regions of the virus. The relative extent to which set-point viremia is impacted by epitope-conservation of CD8(+ T cell responses elicited during early HIV-infection is unknown but has important implications for vaccine design. To address this question, we comprehensively mapped HIV-1 CD8(+ T cell epitope-specificities in 23 ART-naïve individuals during early infection and computed their conservation score (CS by three different methods (prevalence, entropy and conseq on clade-B and group-M sequence alignments. The majority of CD8(+ T cell responses were directed against variable epitopes (p<0.01. Interestingly, increasing breadth of CD8(+ T cell responses specifically recognizing conserved epitopes was associated with lower set-point viremia (r = - 0.65, p = 0.009. Moreover, subjects possessing CD8(+ T cells recognizing at least one conserved epitope had 1.4 log10 lower set-point viremia compared to those recognizing only variable epitopes (p = 0.021. The association between viral control and the breadth of conserved CD8(+ T cell responses may be influenced by the method of CS definition and sequences used to determine conservation levels. Strikingly, targeting variable versus conserved epitopes was independent of HLA type (p = 0.215. The associations with viral control were independent of functional avidity of CD8(+ T cell responses elicited during early infection. Taken together, these data suggest that the next-generation of T-cell based HIV-1 vaccines should focus

  18. High pressure synthesis of BiS2

    DEFF Research Database (Denmark)

    Søndergaard-Pedersen, Simone; Nielsen, Morten Bormann; Bremholm, Martin

    crystal structures and electrical properties.1,2 Up until now, the most sulfur rich phase in the Bi-S phase diagram was Bi2S3.3 For BiS2 the Bi atoms have anisotropic charge distribution and more complex structures are expected when comparing the layered structures of transition metal dichalcogenides....... The possibilities of using high pressure synthesis to discover new phases in the Bi-S binary system were investigated as early as the 1960’s.4 The research led to discovery of a compound with BiS2 stoichiometry, but no structure solution of BiS2 was reported. A reason behind making this new phase is to study...... the physical properties since the related compound Bi2S3 is known to be a thermoelectric material.5 In this research the BiS2 compound was synthesized by a high pressure and high temperature method using a multi-anvil large volume press and the structure was solved by single crystal diffraction. The structure...

  19. Influence of water management and fertilizer application on "1"3"7Cs and "1"3"3Cs uptake in paddy rice fields

    International Nuclear Information System (INIS)

    Wakabayashi, Shokichi; Itoh, Sumio; Kihou, Nobuharu; Matsunami, Hisaya; Hachinohe, Mayumi; Hamamatsu, Shioka; Takahashi, Shigeru

    2016-01-01

    Cesium-137 derived from the Tokyo Electric Power Company's Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident contaminated large areas of agricultural land in Eastern Japan. Previous studies before the accident have indicated that flooding enhances radiocesium uptake in rice fields. We investigated the influence of water management in combination with fertilizers on "1"3"7Cs concentrations in rice plants at two fields in southern Ibaraki Prefecture. Stable Cs ("1"3"3Cs) in the plants was also determined as an analogue for predicting "1"3"7Cs behavior after long-term aging of soil "1"3"7Cs. The experimental periods comprised 3 y starting from 2012 in one field, and 2 y from 2013 in another field. These fields were divided into three water management sections: a long-flooding section without midsummer drainage, and medial-flooding, and short-flooding sections with one- or two-week midsummer drainage and earlier end of flooding than the long-flooding section. Six or four types of fertilizer subsections (most differing only in potassium application) were nested in each water management section. Generally, the long-flooding treatment led to higher "1"3"7Cs and "1"3"3Cs concentrations in both straw and brown rice than medial- and short-flooding treatments, although there were some notable exceptions in the first experimental year at each site. Effects of differing potassium fertilizer treatments were cumulative; the effects on "1"3"7Cs and "1"3"3Cs concentrations in rice plants were not obvious in 2012 and 2013, but in 2014, these concentrations were highest where potassium fertilizer had been absent and lowest where basal dressings of K had been tripled. The relationship between "1"3"7Cs and "1"3"3Cs in rice plants was not correlative in the first experimental year at each site, but correlation became evident in the subsequent year(s). This study demonstrates a novel finding that omitting midsummer drainage and/or delaying drainage during the grain-filling period

  20. Internal friction behavior of liquid Bi-Sn alloys

    International Nuclear Information System (INIS)

    Wu Aiqing; Guo Lijun; Liu Changsong; Jia Erguang; Zhu Zhengang

    2005-01-01

    Pure Bi and Sn and four Bi-Sn alloys distributed on the entire concentration range were selected for internal-friction investigation over a wide temperature range. There exist two peaks in the plots of internal friction versus temperature for liquid Sn, Bi-Sn60 and Bi-Sn90 alloys, one peak being located at about 480 - bar Cand another at about 830 - bar C. Only a single internal-friction peak at about 830 - bar C occurs in liquid Bi-Sn43 (eutectic composition). No internal-friction peak appears in liquid Bi-Sn20 alloy and pure Bi. The height of the internal-friction peaks depends on the content of Sn. The present finding suggests that Sn-rich Bi-Sn alloys may inherit the internal-friction behaviors of pure Sn, whereas Bi-rich Bi-Sn alloy seems to be like pure Bi. The position of the internal-friction peaks is frequency dependent, which resembles the internal-friction feature in structure transition in solids

  1. Internal friction behavior of liquid Bi-Sn alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wu Aiqing [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Guo Lijun [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Liu Changsong [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Jia Erguang [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Zhu Zhengang [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China)]. E-mail: zgzhu@issp.ac.cn

    2005-12-01

    Pure Bi and Sn and four Bi-Sn alloys distributed on the entire concentration range were selected for internal-friction investigation over a wide temperature range. There exist two peaks in the plots of internal friction versus temperature for liquid Sn, Bi-Sn60 and Bi-Sn90 alloys, one peak being located at about 480{sup -}bar Cand another at about 830{sup -}bar C. Only a single internal-friction peak at about 830{sup -}bar C occurs in liquid Bi-Sn43 (eutectic composition). No internal-friction peak appears in liquid Bi-Sn20 alloy and pure Bi. The height of the internal-friction peaks depends on the content of Sn. The present finding suggests that Sn-rich Bi-Sn alloys may inherit the internal-friction behaviors of pure Sn, whereas Bi-rich Bi-Sn alloy seems to be like pure Bi. The position of the internal-friction peaks is frequency dependent, which resembles the internal-friction feature in structure transition in solids.

  2. Study of Cs recovery by extraction chromatography (2)

    International Nuclear Information System (INIS)

    Hoshi, Harutaka; Zhang, Anyun; Uchida, Hiromi; Kuraoka, Etsushu

    2005-02-01

    In order to apply CalixR14 extractant to extraction chromatography for Cs separation, basic characteristics of CalixR14 adsorbent were studied. CalixR14 impregnated resin and CalixR14 + TBP impregnated resin were prepared. CalixR14 extractant showed no adsorption for Cs by liquid-liquid extraction and CalixR14 impregnated resin also showed no adsorption for Cs. Therefore, it is concluded that CalixR14 itself has no affinity for Cs. On the other hand, Cs was adsorbed onto CalixR14-TBP impregnated resin from a concentrated nitric acid solution. The distribution coefficients of Cs were more than 10 cm 3 /g from 2 to 6 M nitric acid. While Rb showed week adsorption, Na, K, Sr and La showed no adsorption and separation factor was over 100. A slight amount of CalixR14 and TBP was leaked from impregnated resin into the aqueous phase. Separation from simulated liquid waste was carried out by using a column packed with CalixR14-TBP adsorbent. Na, K, Sr and La were not adsorbed onto the column, however, Cs and Rb were adsorbed onto the column. Cs and Rb were eluted from the column by water. Cs and Rb were quantitatively recovered. (author)

  3. Vertical profile of 137Cs in soil.

    Science.gov (United States)

    Krstić, D; Nikezić, D; Stevanović, N; Jelić, M

    2004-12-01

    In this paper, a vertical distribution of 137Cs in undisturbed soil was investigated experimentally and theoretically. Soil samples were taken from the surroundings of the city of Kragujevac in central Serbia during spring-summer of 2001. The sampling locations were chosen in such a way that the influence of soil characteristics on depth distribution of 137Cs in soil could be investigated. Activity of 137Cs in soil samples was measured using a HpGe detector and multi-channel analyzer. Based on vertical distribution of 137Cs in soil which was measured for each of 10 locations, the diffusion coefficient of 137Cs in soil was determined. In the next half-century, 137Cs will remain as the source of the exposure. Fifteen years after the Chernobyl accident, and more than 30 years after nuclear probes, the largest activity of 137Cs is still within 10 cm of the upper layer of the soil. This result confirms that the penetration of 137Cs in soil is a very slow process. Experimental results were compared with two different Green functions and no major differences were found between them. While both functions fit experimental data well in the upper layer of soil, the fitting is not so good in deeper layers. Although the curves obtained by these two functions are very close to each other, there are some differences in the values of parameters acquired by them.

  4. Solvothermal modification of BiOCl nanosheets with Bi nanoparticles using ascorbic acid as reductant and the superoxide radicals dominated photocatalytic performance

    Science.gov (United States)

    Cui, Zhankui; Gao, Keke; Ge, Suxiang; Fa, Wenjun

    2017-11-01

    BiOCl nanosheets were solvothermally modified with Bi nanoparticles (NPs) using ascorbic acid as the reductant. The structures of Bi/BiOCl composites were characterized by XRD, Raman spectroscopy, FTIR spectroscopy and SEM. The light absorption properties were measured by UV-vis-NIR spectroscopy. The photocatalytic performances were evaluated by photodegrading methyl orange (MO) and the photocatalytic mechanism was investigated using trapping experiments and a fluorescent probe method. The results show that Bi NPs are uniformly distributed on the surfaces of BiOCl nanosheets and the modification amount of Bi NPs could be well controlled because of the mild property of ascorbic acid as reducing agent. The photocatalytic activities for the composites are improved obviously and the best photocatalytic performance is obtained when the weight ratio of Bi and BiOCl is1:10 and the photochemical reaction rate is 3.5 times that of pure BiOCl nanosheets and 19.7 times of Bi powders. The enhanced photocatalytic efficiency is ascribed to the favorable formation of dominant \\cdot O2- radicals caused by the increased photoinduced electrons from both Bi NPs and BiOCl nanosheets.

  5. The 134Cs uptake by sunflower (Helianthus anuus, Less) cultivated on soil contaminated with 134Cs

    International Nuclear Information System (INIS)

    Poppy Intan Tjahaja; Putu Sukmabuana

    2008-01-01

    One of the methods for remediation of contaminated environment is phytoremediation techniques, i.e. the environmental remediation using plants. In this research the bioavailability of sunflower plant (Helianthus anuus, Less) in radiocaesium uptake from soil was studied for being considered as a phytoremediator later. Sunflower plants were cultivated on soil contaminated with 134 Cs with the concentrations of 29,3 kBq/kg ; 117,2 kBq/kg ; 557 kBq/kg for 45 days. As control the sunflowers were also cultivated on non contaminated soil. Observation was carried out every 5 days by sampling 3 plants and soils. The plant and soil samples were dried using infra red lamp for 24 hours, and then counted using gamma spectrometer. The counting results i.e. 134 Cs concentration on soil and plant parts were then analyzed to obtain transfer factor (TF) values. The highest TF values was reached on 26 th day, i.e. 0,87; 1,89 ; 2,82 for initial soil 134 Cs concentrations of 29,3 Bq/g ; 117,2 Bq/g ; 557 Bq/g, respectively. The TF values obtained expressed the capability of plants to accumulate 134 Cs from soils. The observation to the plants growth showed that the plants grew normally on the 134 Cs contaminated soil until the concentration of 557 Bq/g. The sunflower can be considered to be phytoremediator of andosol soil contaminated with Cs radionuclides. (author)

  6. ICT media design for higher grade of elementary school mathematics learning using CS6 program

    Science.gov (United States)

    Zainil, M.; Prahmana, R. C. I.; Helsa, Y.; Hendri, S.

    2017-12-01

    Technological innovation contributes to the emerging of new possibilities to change the learning process. The development of technology could bring the higher quality of education through the integration of technology in the learning. The purpose of this research is to create an interactive multimedia using CS6 program for mathematics learning in higher grade of elementary school. It was a development research using ADDIE model which consists of analysis, design, and evaluation stages. It has successfully developed interactive multimedia in a form of learning CD used in the material of plane figures and solid figures. The prototype has been validated and then tested for the 4th grade of elementary schools. Two schools were involved and the students taught by utilizing the prototype, and then, in the end of learning, they are examined to determine the learning result. There were 72% of the students passed the examination as they classified at good and excellent categories. Finally, the use of CS6 program is promising to help the students learning plane and solid figure in mathematics learning.

  7. SR-XRF imaging of Cs highly accumulated in vegetables

    International Nuclear Information System (INIS)

    Nakai, Izumi; Oda, Nahoko; Terada, Yasuko

    2011-01-01

    Accumulation of Cs in vegetables was studied with regard to the remediation of radioactive Cs from a nuclear plant accident in Fukushima. It was found that Brassica oleracea var. capitata, Brassica campestris var. perviridis, and Lactuca sativa accumulated Cs to a level of more than 10000 ppm (dry weight) when they were cultivated in 1 mM Cs solution. Two-dimensional distributions of Cs were revealed by SR-XRF imaging showing a homogeneous distribution of Cs in the plant bodies. (author)

  8. Radioecological studies of 137Cs in limnological ecosystems. Biochemical states of 137Cs accumulated in killifish (Medaka, Oryzias latipes) meat

    International Nuclear Information System (INIS)

    Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki; Izumo, Yoshiro; Nakamura, Fumio.

    1997-01-01

    Biochemical states of 137 Cs accumulated in killifish's (Medaka, Oryzias latipes) meat were investigated in order to elucidate the accumulation mechanism of the radionuclide in goldfish, Carassius auratus auratus, examined in our preceding report. Most of 137 Cs radioactivity in the killifish's raw meat accumulated this radionuclide in the radioactive freshwater, were found in the non-protein nitrogenous compound (NPNC) fraction (>92%), also in the killifish's control raw meat mixed with 137 Cs, the difference between both meat samples was not clear. As the results of gel filtration profiles on Sephadex G-25 for the NPNC fraction of these meats, each only one radioactive peak was shown, also similar to 137 CsCl solution. Moreover, these peaks appeared at the same position. On the other hand, the peak positions absorbed at OD 280nm in the samples were different from those of each radioactive peak. It was so suggested that 137 Cs accumulated in the killifish's meat was shown not to be binding to protein's composition. Furthermore, as the results on thin-layer chromatography, ion-exchange resin chromatography and reaction with 137 Cs in samples and ammonium phosphomolybdate, 137 Cs in the NPNC fraction of the killifish's meat was not almost different from those of each control and 137 CsCl solution. (author)

  9. Comparison of CsI(Tl) and CsI(Na) partially slotted crystals for high-resolution SPECT imaging

    International Nuclear Information System (INIS)

    Giokaris, N.; Loudos, G.; Maintas, D.; Karabarbounis, A.; Lembesi, M.; Spanoudaki, V.; Stiliaris, E.; Boukis, S.; Sakellios, N.; Karakatsanis, N.; Gektin, A.; Boyarintsev, A.; Pedash, V.; Gayshan, V.

    2006-01-01

    Dedicated systems based on Position Sensitive Photomultiplier Tubes (PSPMTs) coupled to scintillators, have been used over the past years for the construction of compact systems, suitable for applications such as small animal imaging and small organs imaging. Most of the proposed systems are based on fully pixelized scintillators. Previous studies have shown that partially slotted scintillators offer a good compromise between cost, energy resolution and spatial resolution. In this work, the performance of two sets of CsI(Tl) and CsI(Na) partially slotted crystals is compared. Initial results show that CsI(Tl) scintillators are more suitable for gamma-ray detection, since their performance in terms of sensitivity, spatial and energy resolution is superior than that of CsI(Na)

  10. Development of new ionic gelation strategy: Towards the preparation of new monodisperse and stable hyaluronic acid/β-cyclodextrin-grafted chitosan nanoparticles as drug delivery carriers for doxorubicin

    Science.gov (United States)

    Mihoub, Amina Ben; Saidat, Boubakeur; Bal, Youssef; Frochot, Céline; Vanderesse, Régis; Acherar, Samir

    2018-03-01

    In the present study, β-cyclodextrin-grafted chitosan nanoparticles (β-CD- g-CS NPs) were prepared using a new ionic gelation strategy involving a synergistic effect of NaCl (150 mmol/L), 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES, 10 mmol/L), and water bath sonication. This new strategy afforded smaller and more monodisperse β-CD- g-CS NPs vs. the classical ionic gelation method. New HA/β-CD- g-CS NPs were also prepared using the above-mentioned strategy by adding hyaluronic acid (HA) to the β-CD- g-CS copolymer at different weight ratios until the ZP values conversion. The best result was obtained with the weight ratio of w(HA): w(β-CD- g-CS) = 2:1 and furnished new spherical and smooth HA/β-CD- g-CS NPs. Furthermore, the stability of β- CD- g-CS NPs and HA/β-CD- g-CS NPs at 4°C in physiological medium (pH 7.4) was compared for 3 weeks period and showed that HA/β-CD- g-CS NPs were more stable all maintaining their monodispersity and high negative ZP values compared to β-CD- g-CS NPs. Finally, preliminary study of HA/β-CD- g-CS NPs as carrier for the controlled release of the anticancer drug doxorubicin was investigated. These new HA/β-CD- g-CS NPs can potentially be used as drug delivery and targeting systems for cancer treatment.

  11. Phonons of single quintuple Bi 2 Te 3 and Bi 2 Se 3 films and bulk materials

    KAUST Repository

    Cheng, Wei; Ren, Shang-Fen

    2011-01-01

    Phonons of single quintuple films of Bi2Te3 and Bi2Se3 and corresponding bulk materials are calculated in detail by MedeA (a trademark of Materials Design) and Vienna ab initio simulation package (VASP). The calculated results with and without spin-orbit couplings are compared, and the important roles that the spin-orbit coupling plays in these materials are discussed. A symmetry breaking caused by the anharmonic potentials around Bi atoms in the single quintuple films is identified and discussed. The observed Raman intensity features in Bi 2Te3 and Bi2Se3 quintuple films are explained. © 2011 American Physical Society.

  12. Phonons of single quintuple Bi 2 Te 3 and Bi 2 Se 3 films and bulk materials

    KAUST Repository

    Cheng, Wei

    2011-03-10

    Phonons of single quintuple films of Bi2Te3 and Bi2Se3 and corresponding bulk materials are calculated in detail by MedeA (a trademark of Materials Design) and Vienna ab initio simulation package (VASP). The calculated results with and without spin-orbit couplings are compared, and the important roles that the spin-orbit coupling plays in these materials are discussed. A symmetry breaking caused by the anharmonic potentials around Bi atoms in the single quintuple films is identified and discussed. The observed Raman intensity features in Bi 2Te3 and Bi2Se3 quintuple films are explained. © 2011 American Physical Society.

  13. CsI and some new photocathodes

    International Nuclear Information System (INIS)

    Anderson, D.F.; Kwan, S.; Peskov, V.

    1993-06-01

    A discussion of the possible sources of discrepancies in the measurements of the quantum efficiency of CsI photocathodes is presented. We propose that the major causes for disagreements in QE are due to the QE dependence on the current density extracted from the photocathode, on the electric field, and on the temperature of the photocathode. Preliminary results on TMAE enhanced GaAs and Si, plus TMAE protected CsTe and SbCs photocathodes, operated in gas, are also presented

  14. Demonstration of surface transport in a hybrid Bi2Se3/Bi2Te3 heterostructure

    OpenAIRE

    Zhao, Yanfei; Chang, Cui-Zu; Jiang, Ying; DaSilva, Ashley; Sun, Yi; Wang, Huichao; Xing, Ying; Wang, Yong; He, Ke; Ma, Xucun; Xue, Qi-Kun; Wang, Jian

    2013-01-01

    In spite of much work on topological insulators (TIs), systematic experiments for TI/TI heterostructures remain absent. We grow a high quality heterostructure containing single quintuple layer (QL) of Bi2Se3 on 19 QLs of Bi2Te3 and compare its transport properties with 20 QLs Bi2Se3 and 20 QLs Bi2Te3. All three films are grown on insulating sapphire (0001) substrates by molecular beam epitaxy (MBE). In situ angle-resolved photoemission spectroscopy (ARPES) provides direct evidence that the su...

  15. Effect of oxidant on resputtering of Bi from Bi--Sr--Ca--Cu--O films

    International Nuclear Information System (INIS)

    Grace, J.M.; McDonald, D.B.; Reiten, M.T.; Olson, J.; Kampwirth, R.T.; Gray, K.E.

    1992-01-01

    The type and partial pressure of oxidant mixed with argon can affect the selective sputtering of Bi in composite-target, magnetron-sputtered Bi--Sr--Ca--Cu--O films. Comparative studies using oxygen and ozone show that ozone is a more potent oxidant, as well as a more potent source of resputterers than is oxygen. Severe resputtering from ozone is significantly reduced by a -40 V potential on the sample block. We suggest that oxygen causes resputtering by forming O + 2 , which interacts with the target to produce energetic O - . In contrast, ozone may form lower-energy O - by electron impact in the dark space. Negative oxygen ions from the target itself may be responsible for a background resputtering effect. Our results and those found for Y--Ba--Cu--O by others are comparable. Bi in Bi--Sr--Ca--Cu--O behaves as Ba in Y--Ba--Cu--O, with regard to selective resputtering; furthermore, the response of Sr, Ca, and Cu to oxygen in sputtered Bi--Sr--Ca--Cu--O is similar to what is observed for Cu in Y--Ba--Cu--O

  16. Absolute activity measurements with the windowless 4π-CsI(Tl)-sandwich spectrometer

    International Nuclear Information System (INIS)

    Denecke, B.

    1994-01-01

    The windowless 4π-CsI(Tl)-sandwich spectrometer consists of two scintillation crystals sandwiching radioactive sources deposited on thin plastic foils. This configuration has a solid angle very close to 4π sr. The detectors are sensitive to charged particles with energies > 15 keV and measure photons of 15-200 keV with a probability > 98%. Disintegration rates of samples of radionuclides with complex decay modes can be determined directly from the measured count rates with uncertainties below 0.3%. Radionuclide solutions of 57 Co, 109 Cd, 125 I, 152 Eu and 192 Ir were standardised, partly in the framework of international comparisons. A detailed description of the spectrometer and the measurement procedure is given. (orig.)

  17. Absolute activity measurements with the windowless 4π-CsI(Tl)-sandwich spectrometer

    Science.gov (United States)

    Denecke, B.

    1994-01-01

    The windowless 4π-CsI(Tl)-sandwich spectrometer consists of two scintillation crystals sandwiching radioactive sources deposited on thin plastic foils. This configuration has a solid angle very close to 4π sr. The detectors are sensitive to charged particles with energies > 15 keV and measure photons of 15-200 keV with a probability > 98%. Disintegration rates of samples of radionuclides with complex decay modes can be determined directly from the measured count rates with uncertainties below 0.3%. Radionuclide solutions of 57Co, 109Cd, 125I, 152Eu and 192Ir were standardised, partly in the framework of international comparisons. A detailed description of the spectrometer and the measurement procedure is given.

  18. CS EMISSION NEAR MIR-BUBBLES

    International Nuclear Information System (INIS)

    Watson, C.; Devine, Kathryn; Quintanar, N.; Candelaria, T.

    2016-01-01

    We survey 44 young stellar objects located near the edges of mid-IR-identified bubbles in CS (1–0) using the Green Bank Telescope. We detect emission in 18 sources, indicating young protostars that are good candidates for being triggered by the expansion of the bubble. We calculate CS column densities and abundances. Three sources show evidence of infall through non-Gaussian line-shapes. Two of these sources are associated with dark clouds and are promising candidates for further exploration of potential triggered star formation. We obtained on-the-fly maps in CS (1–0) of three sources, showing evidence of significant interactions between the sources and the surrounding environment

  19. CS EMISSION NEAR MIR-BUBBLES

    Energy Technology Data Exchange (ETDEWEB)

    Watson, C. [Manchester University, Department of Physics, 604 E. College Ave., North Manchester, IN 46962 (United States); Devine, Kathryn [College of Idaho, Department of Physics, 2112 Cleveland Blvd, Caldwell, ID 83605 (United States); Quintanar, N. [Texas A and M University, Department of Nuclear Engineering, 401 Joe Routt Blvd, College Station, TX 77843 (United States); Candelaria, T., E-mail: cwatson@manchester.edu, E-mail: KDevine@collegeofidaho.edu, E-mail: nrquintanar@tamu.edu, E-mail: tcandela@nmt.edu [New Mexico Institute of Mining and Technology, Department of Physics, 801 Leroy Place, Socorro, NM 87801 (United States)

    2016-02-10

    We survey 44 young stellar objects located near the edges of mid-IR-identified bubbles in CS (1–0) using the Green Bank Telescope. We detect emission in 18 sources, indicating young protostars that are good candidates for being triggered by the expansion of the bubble. We calculate CS column densities and abundances. Three sources show evidence of infall through non-Gaussian line-shapes. Two of these sources are associated with dark clouds and are promising candidates for further exploration of potential triggered star formation. We obtained on-the-fly maps in CS (1–0) of three sources, showing evidence of significant interactions between the sources and the surrounding environment.

  20. Comparative study of phase structure and dielectric properties for K0.5Bi0.5TiO3-BiAlO3 and LaAlO3-BiAlO3

    International Nuclear Information System (INIS)

    Hou, Yudong; Zheng, Mupeng; Si, Meiju; Cui, Lei; Zhu, Mankang; Yan, Hui

    2013-01-01

    In this work, two perovskite-type compounds, K 0.5 Bi 0.5 TiO 3 and LaAlO 3 , have been selected as host material to incorporate with BiAlO 3 using a solid-state reaction route. The phase evolution and dielectric properties for both systems have been investigated in detail. For the K 0.5 Bi 0.5 TiO 3 -BiAlO 3 system, it is interesting to find that when using Bi 2 O 3 , Al 2 O 3 , K 2 CO 3 , and TiO 2 as starting materials, the formed compounds are K 0.5 Bi 0.5 TiO 3 -K 0.5 Bi 4.5 Ti 4 O 15 and Al 2 O 3 only plays a dopant role. There are two distinct dielectric peaks appearing in the patterns of temperature dependence of dielectric constant, corresponding to the phase-transition points of perovskite-type K 0.5 Bi 0.5 TiO 3 and Aurivillius-type K 0.5 Bi 4.5 Ti 4 O 15 , independently. In comparison, using Bi 2 O 3 , Al 2 O 3 , and La 2 O 3 as starting materials, the pure perovskite phase LaAlO 3 -BiAlO 3 can be obtained. Compared to the inherent paraelectric behavior in LaAlO 3 , the diffuse phase-transition phenomena can be observed in the LaAlO 3 -BiAlO 3 binary system, which corresponds well to the Vogel-Fulcher (VF) relationship. Moreover, compared to pure LaAlO 3 , the synthesized LaAlO 3 -BiAlO 3 compound shows enhanced dielectric properties, which are promising in application as gate dielectric materials. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Fractionation of 137Cs and Pu in natural peatland

    International Nuclear Information System (INIS)

    Mihalík, Ján; Bartusková, Miluše; Hölgye, Zoltán; Ježková, Tereza; Henych, Ondřej

    2014-01-01

    High Cs-137 concentrations in plants growing on peatland inspired us to investigate the quantity of its bioavailable fraction in natural peat. Our investigation aims to: a) estimate the quantity of bioavailable Cs-137 and Pu present in peat, b) verify the similarity of Cs-137 and K-40 behaviours, and c) perform a quantification of Cs-137 and Pu transfer from peat to plants. We analysed the vertical distribution of Cs-137 and Pu isotopes in the peat and their concentrations in plants growing on these places. Bioavailability of radionuclides was investigated by sequential extraction. Sequential analyses revealed that it was the upper layer which contained the majority of Cs-137 in an available form while deeper layers retained Cs-137 in immobile fractions. We can conclude that 18% of all Cs-137 in the peat is still bioavailable. Despite of the low quantity of bioavailable fraction of Cs-137 its transfer factor reached extremely high values. In the case of Pu, 64% of its total amount was associated with fulvic/humic acids which resulted in the high transfer factor from peat to plants. 27 years after the Chernobyl nuclear accident, the significant part of radionuclides deposited in peatland is still bioavailable. - Highlights: • Decrease of exchangeable 137 Cs and its increase in residual fraction with depth. • High 137 Cs transfer factor contrary to its low quantity in bioavailable fractions. • Fulvic/humic acids are a more effective carrier for Pu than for Cs

  2. Bioaccumulation and elimination of {sup 60} Co and {sup 137} Cs by Anomalocardia brasiliana (Gmelin, 1791) (Mollusca bivalvia). Remobilization of {sup 60} Co, retained in marine sediment by microbial activity; Bioacumulacao e eliminacao de {sup 60}Co e {sup 137}Cs por anomalocardia brasiliana (Gmelin, 1791) (Mollusca bivalvia). Remobilizacao de {sup 60}Co retido em sedimento marinho por atividade microbiana

    Energy Technology Data Exchange (ETDEWEB)

    Mayr, L M

    1984-05-01

    It was studied the capacity of a bi valve mollusc Anomalocardia brasiliana, which lives in the local bottom sediment, to remobilize {sup 60} Co previously sorbed in the sediment. Laboratory experiments demonstrated that the transference of {sup 60} Co from the sediment to the animal was insignificant (bioaccumulation factor (BF) of the order of 10{sup -3}). At the same time, the capacity of microorganisms, present in the bottom sediment, to remobilize {sup 60} Co was studied. The results showed that this via of transference was important, considering the much greater microorganism biomass in relation to the biomass of bentonic organisms, as a whole. For {sup 137} Cs the determined BF from water to the animal was 2.2. and, as in the case of {sup 60} Co, the soft tissues concentrated more {sup 137} Cs than shell. Remaining viscera showed the highest BFs. In another series of experiments, the loss of {sup 60} Co or {sup 137} Cs, previously accumulated by A. brasiliana, was followed in aquaria with or without sediment and the respective biological half-lives were calculated. Soft tissues retained {sup 60} Co longer (biological half-life = 117 days) than shells, whereas for {sup 137} Cs the opposite was observed and shells showed a biological half life of 38.5 days. The low values of {sup 60} Co and {sup 137} Cs BF{sub S} do not allow to classify A. brasiliana as good biological indicator for pollution by there radionuclides. However since A brasiliana is consumed by the local population and is commercialized to other areas, it was recommended that its contamination by {sup 60} Co or {sup 137} Cs should be monitored. (author).

  3. {sup 137}Cs in northern Adriatic sediments

    Energy Technology Data Exchange (ETDEWEB)

    Barisic, D; Lulic, S; Vdovic, N; Vertacnik, A [Center for Marine Research - Department Zagreb, ' Ruder Boskovic' Institute, Zagreb (Croatia); Juracic, M [Department of Geology, Faculty of Natural Sciences, University of Zagreb, Zagreb (Croatia)

    1996-01-01

    The activity of {sup 137}Cs in shallow northern Adriatic sediments was obtained on the basis of measurement results from 25 sediment box cores, sampled during the Adriatic Scientific COoperation Program (ASCOP) 16 cruise in the summer 1990. {sup 137}Cs was determined in surface sediments (0-3 cm) and 12-15 cm-deep sediment. It was found that the lowest caesium concentrations correspond to sands, which are spread along the Croatian coast. Parallel to the Italian coast, {sup 137}Cs concentrations in pelites are the highest. It seems that the influence of Po River is significant for {sup 137}Cs activities in recent marine sediments along Italian coast south of Po River delta. Significantly higher {sup 137}Cs activities in 0-3 cm sediment layer can be attributed to the deposition caused by Chernobyl accident. (author)

  4. In vitro evaluation of 213Bi-rituximab versus external gamma irradiation for the treatment of B-CLL patients: relative biological efficacy with respect to apoptosis induction and chromosomal damage

    International Nuclear Information System (INIS)

    Vandenbulcke, Katia; Lahorte, Christophe; Slegers, Guido; De Vos, Filip; Dierckx, Rudi A.; Offner, Fritz; Philippe, Jan; Apostolidis, Christos; Molinet, Roger; Nikula, Tuomo K.; Bacher, Klaus; De Gelder, Virginie; Vral, Anne; Thierens, Hubert

    2003-01-01

    External source radiotherapy and beta radioimmunotherapy (RIT) are effective treatments for lymphoid malignancies. The development of RIT with alpha emitters is attractive because of the high linear energy transfer (LET) and short path length, allowing higher tumour cell kill and lower toxicity to healthy tissues. We assessed the relative biological efficacy (RBE) of alpha RIT (in vitro) compared to external gamma irradiation with respect to induction of apoptosis in B chronic lymphocytic leukaemia (B-CLL) and induction of chromosomal damage in healthy donor B and T lymphocytes. The latter was measured by a micronucleus assay. 213 Bi was eluted from a 225 Ac generator and conjugated to CD20 antibody (rituximab) with CHX-A''-DTPA as a chelator. B-CLL cells from five patients were cultured for 24 h in RPMI/10% FCS while exposed to 213 Bi conjugated to CD20 antibody or after external 60 Co gamma irradiation. Binding assays were performed in samples of all patients to calculate the total absorbed dose. Apoptosis was scored by flow cytometric analyses of the cells stained with annexin V-FITC and 7-AAD. Apoptosis was expressed as % excess over spontaneous apoptosis in control. Full dose range experiments demonstrated 213 Bi-conjugated CD20 antibody to be more effective than equivalent doses of external gamma irradiation, but showed that similar plateau values were reached at 10 Gy. The RBE for induction of apoptosis in B-CLL was 2 between 1.5 and 7 Gy. The micronucleus yield in lymphocytes of healthy volunteers was measured to assess the late toxicity caused by induction of chromosomal instability. While gamma radiation induced a steady increase in micronucleus yields in B and T cells, the damage induced by 213 Bi was more dramatic, with RBE ranging from 5 to 2 between 0.1 Gy and 2 Gy respectively. In contrast to gamma irradiation, 213 Bi inhibited mitogen-stimulated mitosis almost completely at 2 Gy. In conclusion, high-LET targeted alpha particle exposure killed B

  5. Crystalline structure and XMCD studies of Co40Fe40B20 grown on Bi2Te3, BiTeI and Bi2Se3

    OpenAIRE

    Kaveev, A. K.; Sokolov, N. S.; Suturin, S. M.; Zhiltsov, N. S.; Golyashov, V. A.; Tereshchenko, O. E.; Prosvirin, I. P.; Kokh, K. A.; Sawada, M.

    2018-01-01

    Epitaxial films of Co40Fe40B20 (further - CoFeB) were grown on Bi2Te3(001) and Bi2Se3(001) substrates by laser molecular beam epitaxy (LMBE) technique at 200-400C. Bcc-type crystalline structure of CoFeB with (111) plane parallel to (001) plane of Bi2Te3 was observed, in contrast to polycrystalline CoFeB film formed on Bi2Se3(001) at RT using high-temperature seeding layer. Therefore, structurally ordered ferromagnetic thin films were obtained on the topological insulator surface for the firs...

  6. Thermal analysis and phase diagrams of the LiF BiF{sub 3} e NaF BiF{sub 3} systems; Analise termica e diagramas de fase dos sistemas LiF-BiF{sub 3} e NaF-BiF{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Gerson Hiroshi de Godoy

    2013-07-01

    Investigations of the binary systems LiF-BiF{sub 3} and NaF-BiF{sub 3} were performed with the objective of clarifying the thermal behavior and phase equilibria of these systems and their intermediary phases, an important requisite for high-quality crystal growth. Several samples in the entire range of compositions (0 to 100 mol% BiF{sub 3}) of both systems were subjected to experiments of differential thermal analysis (DTA) and thermogravimetry (TG), and also of differential scanning calorimetry (DSC). A few specific compositions were selected for X-ray diffraction to supplement the experimental data. Due to the high vulnerability of BiF{sub 3} to oxygen contamination, its volatility and propensity to destroy metal parts upon heating, it was necessary to determine the optimal conditions for thermal analysis before investigating the systems themselves. Phase relations in the system LiF-BiF{sub 3} were completely clarified and a phase diagram was calculated and evaluated via the commercial software Factsage. The diagram itself consists in a simple peritectic system in which the only intermediary compound, LiBiF{sub 4}, decomposes into LiF and a liquid phase. The NaF-BiF{sub 3} system could not be completely elucidated and the phase relations in the NaF poor side (> 50% BiF{sub 3}) are still unknown. In the NaF rich side, however, the possible peritectoid decomposition of the compound NaBiF{sub 4} was identified. In both systems X-ray diffraction yielded crystal structures discrepant with the literature for the intermediary phases, LiBiF{sub 4}, NaBiF{sub 4} and a solid solution of NaF and BiF{sub 3} called {sup I.} The observed structures remain unknown and explanations for the discrepancies were proposed. (author)

  7. Transfer of 137Cs to wild vegetables

    International Nuclear Information System (INIS)

    Ito, Nobuhiko; Natsuhori, Masahiro; Mezawa, Akane; Kawakami, Akira

    1998-01-01

    For the evaluation of internal radiation dose, it is needed to estimate the amount of radionuclide incorporated to human body using a simulation model. 137 Cesium (Cs) is easily transferred associating with food intake as well as potassium and so, Cs is an important nuclide for evaluation of internal radiation. 137 Cs concentrations in wild vegetables are higher than those of cultured vegetables and milk. Therefore, the transfer coefficients of 137 Cs from soil to wild vegetables were estimated in this study. Wild vegetables and soils of their farms were collected in the Hakkoda Mountain range of Aomori Prefecture. The levels of 137 Cs in wild vegetables were 0.42-18.35 (Bq/kg), whereas those in cabbage and spinach were 0.08 and 0.01 (Bq/kg), respectively, indicating that the Cs level is dozens to several hundreds times higher in wild vegetables than cultured ones. And the transfer coefficient was estimated as 0.003-0.94 for the former and 0.001-0.8 for the latter. On the other hand, 1 37 Cs levels of the soils on which wild vegetables grew was 28.0 Bq/kg and it was 3.9 Bq/kg for the farm soil. Furthermore, the effects of water content and pH of the soil on the transfer coefficient were studied. (M.N.)

  8. Light-emitting diodes based on two-dimensional PA2(CsPbBr3)n-1PbBr4 layered perovskites%基于PA2(CsPbBr3)n-1PbBr4二维层状钙钛矿的电致发光二极管

    Institute of Scientific and Technical Information of China (English)

    孟妍; 牛连斌; 许龙; 林春燕; 熊自阳; 熊祖洪; 陈平

    2018-01-01

    进一步提高全无机卤铅钙钛矿材料CsPbBr3的发光效率,对制备高效率、高稳定性的电致发光二极管(PeLED)具有重要意义.制备纳米级的钙钛矿量子点,一方面有助于提高激子的束缚能和钙钛矿晶体的荧光效率,另一方面也有利于形成连续、致密的二维层状钙钛矿薄膜.本文采用“原位生长”的策略,将一种具有长链结构的丙基溴化胺(CH3CH2CH2NH3Br,PABr)作为添加剂,与CsPbBr3的前驱体溶液进行共混,得到PA2(CsPbBr3)n-1PbBr4钙钛矿量子点.形成的二维层状钙钛矿薄膜均匀致密,在光致发光条件下,呈现出明亮的蓝绿光发射(发光峰位于506 nm).在电致发光方面,基于PA2(CsPbBr3)n-1PbBr4的PeLED启亮电压为~4.2 V,最大亮度为~2370 cd/m2,最高电流效率为~1.06 cd/A,最高EQE为~0.57%.相较于传统方法,本工作在制作工艺、成膜质量以及PeLED的发光效率有了显著的提升,为将来进一步探索低成本、高效率的蓝光PeLEDs提供了一种可行的思路.%Solution-processed organometal halide perovskites (formulated as ABX3,where A is the methylammonium (CH3NH3+)(MA) or metal cesium cation (Cs+),B is the lead cation (Pb2+) and X is the halide anion (Br-,I-,Cl-)) are promising candidates for next generation light-emitting materials owing to their unique optoelectronic properties.These properties mainly include extremely high photoluminescence quantum yield (PLQY),easily tunable band gap and narrow emission characteristics.During the past two years,impressive progresses have been made in perovskite light-emitting diodes (PeLED) with hybrid organic-inorganic perovskite materials (i.e.,CH3NH3PbBr3).So far,the best external quantum efficiency (EQE) of CH3NH3PbBr3-based PeLED was reaching up to ~8.53% which was close to the results of organic light-emitting diodes (OLED).Despite the remarkable performance of the devices demonstrated,the stability of organic-inorganic hybrid perovskites

  9. Imbedded Nanocrystals of CsPbBr3 in Cs4 PbBr6 : Kinetics, Enhanced Oscillator Strength, and Application in Light-Emitting Diodes.

    Science.gov (United States)

    Xu, Junwei; Huang, Wenxiao; Li, Peiyun; Onken, Drew R; Dun, Chaochao; Guo, Yang; Ucer, Kamil B; Lu, Chang; Wang, Hongzhi; Geyer, Scott M; Williams, Richard T; Carroll, David L

    2017-11-01

    Solution-grown films of CsPbBr 3 nanocrystals imbedded in Cs 4 PbBr 6 are incorporated as the recombination layer in light-emitting diode (LED) structures. The kinetics at high carrier density of pure (extended) CsPbBr 3 and the nanoinclusion composite are measured and analyzed, indicating second-order kinetics in extended and mainly first-order kinetics in the confined CsPbBr 3 , respectively. Analysis of absorption strength of this all-perovskite, all-inorganic imbedded nanocrystal composite relative to pure CsPbBr 3 indicates enhanced oscillator strength consistent with earlier published attribution of the sub-nanosecond exciton radiative lifetime in nanoprecipitates of CsPbBr 3 in melt-grown CsBr host crystals and CsPbBr 3 evaporated films. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Highly efficient visible-light-induced photocatalytic activity of Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterojunction photocatalysts

    Energy Technology Data Exchange (ETDEWEB)

    Chaiwichian, Saranyoo [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai50200 (Thailand); Inceesungvorn, Burapat [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Wetchakun, Khatcharin [Program of Physics, Faculty of Science, Ubon Ratchathani Rajabhat University, Ubon Ratchathani 34000 (Thailand); Phanichphant, Sukon [Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Kangwansupamonkon, Wiyong [National Nanotechnology Center, Thailand Science Park, Phahonyotin Road, Klong 1, Klong Luang, Phathumthani 12120 (Thailand); Wetchakun, Natda, E-mail: natda_we@yahoo.com [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai50200 (Thailand)

    2014-06-01

    Highlights: • Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterojunction photocatalysts were obtained using hydrothermal method. • Physicochemical properties played a significant role on photocatalytic efficiency. • Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterogeneous structures were greatly enhanced for degradation of MB. • A tentative mechanism of charge transfer process in MB degradation was proposed. - Abstract: The Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterojunction photocatalysts were synthesized by hydrothermal method. Physical properties of the heterojunction photocatalyst samples were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The XRD results indicated that BiVO{sub 4} retain monoclinic and tetragonal structures, while Bi{sub 2}WO{sub 6} presented as orthorhombic structure. The Brunauer, Emmett and Teller (BET) adsorption–desorption of nitrogen gas for specific surface area determination at the temperature of liquid nitrogen was performed on all samples. UV–vis diffuse reflectance spectra (UV–vis DRS) were used to identify the absorption range and band gap energy of the heterojunction photocatalysts. The photocatalytic performance of Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterojunction photocatalysts was studied via the photodegradation of methylene blue (MB) under visible light irradiation. The results indicated that the heterojunction photocatalyst at 0.5:0.5 mole ratio of Bi{sub 2}WO{sub 6}:BiVO{sub 4} shows the highest photocatalytic activity.

  11. Exploratory Bi-Factor Analysis: The Oblique Case

    Science.gov (United States)

    Jennrich, Robert I.; Bentler, Peter M.

    2012-01-01

    Bi-factor analysis is a form of confirmatory factor analysis originally introduced by Holzinger and Swineford ("Psychometrika" 47:41-54, 1937). The bi-factor model has a general factor, a number of group factors, and an explicit bi-factor structure. Jennrich and Bentler ("Psychometrika" 76:537-549, 2011) introduced an exploratory form of bi-factor…

  12. In-Situ Hydrothermal Synthesis of Bi-Bi2O2CO3 Heterojunction Photocatalyst with Enhanced Visible Light Photocatalytic Activity

    Science.gov (United States)

    Kar, Prasenjit; Maji, Tuhin Kumar; Nandi, Ramesh; Lemmens, Peter; Pal, Samir Kumar

    2017-04-01

    Bismuth containing nanomaterials recently received increasing attention with respect to environmental applications because of their low cost, high stability and nontoxicity. In this work, Bi-Bi2O2CO3 heterojunctions were fabricated by in-situ decoration of Bi nanoparticles on Bi2O2CO3 nanosheets via a simple hydrothermal synthesis approach. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) were used to confirm the morphology of the nanosheet-like heterostructure of the Bi-Bi2O2CO3 composite. Detailed ultrafast electronic spectroscopy reveals that the in-situ decoration of Bi nanoparticles on Bi2O2CO3 nanosheets exhibit a dramatically enhanced electron-hole pair separation rate, which results in an extraordinarily high photocatalytic activity for the degradation of a model organic dye, methylene blue (MB) under visible light illumination. Cycling experiments revealed a good photochemical stability of the Bi-Bi2O2CO3 heterojunction under repeated irradiation. Photocurrent measurements further indicated that the heterojunction incredibly enhanced the charge generation and suppressed the charge recombination of photogenerated electron-hole pairs.

  13. Electrophysical properties of CdS layers obtained by pulverization method and annealed in hydrogen ambience; Proprietati electrofizice ale straturilor de CdS obtinute prin metoda pulverizarii cu tratare termica in hidrogen

    Energy Technology Data Exchange (ETDEWEB)

    Botnariuc, Vasile; Gorceac, Leonid; Coval, Andrei; Cinic, Boris; Chetrus, Petru; Raevschi, Semion; Banu, Semion [Univ. de Stat din Moldova, Chisinau (Moldova, Republic of)

    2012-07-15

    CdS layers were grown from the aqueous solution of CdCl{sub 2}/(NH{sub 2}){sub 2} CS having a molarity of 0,1 M by pulverization method in the temperature range of (250-450) degrees Celsius. The layers were heat treated in a hydrogen flow during 20 min at the temperatures of 350 degrees Celsius and 450 degrees Celsius. Electro- physical properties and photoluminescence of these layers were studied. For the layers deposited at 450 degrees Celsius a slight decrease of charge carriers concentration is observed with the increase of treatment temperature up to 450 degrees Celsius. The photoluminescence spectrum consists of a large band in the energy interval from 1,6 eV to 2,6 eV. A photoluminescence peak with the energy of 1,95 eV is observed, which is shifting with CdS layer growth temperature increase and if reaches the value of 2,5 eV for the layers grown at the temperature of 450 degrees Celsius. (authors)

  14. Facile synthesis of BiOF/Bi{sub 2}O{sub 3}/reduced graphene oxide photocatalyst with highly efficient and stable natural sunlight photocatalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Limin; Dong, Shuying; Li, Qilu; Feng, Jinglan; Pi, Yunqing; Liu, Menglin [School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environmental and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007 (China); Sun, Jingyu, E-mail: sunjy-cnc@pku.edu.cn [Center for Nanochemistry (CNC), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Sun, Jianhui, E-mail: sunjh@htu.cn [School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environmental and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007 (China)

    2015-06-05

    Highlights: • A dual Bi-based ball-shaped material BiOF/Bi{sub 2}O{sub 3} were facilely synthesized. • The composition effect of BiOF/Bi{sub 2}O{sub 3}/RGO hybrid were probed for the first time. • The photocatalytic performances were evaluated upon natural sunlight irradiation. • The composites showed a twofold augmentation in the degradation efficiency. • The hybrid photocatalyst can be easily recycled for three times. - Abstract: A facile and efficient route for the controllable synthesis of BiOF/Bi{sub 2}O{sub 3} nanostructures by hydrolysis method was reported, where the as-prepared BiOF/Bi{sub 2}O{sub 3} was subsequently incorporated with reduced graphene oxide (RGO) sheets to form BiOF/Bi{sub 2}O{sub 3}/RGO composites. The obtained BiOF/Bi{sub 2}O{sub 3} and BiOF/Bi{sub 2}O{sub 3}/RGO composites were well characterized with the aid of various techniques to probe their crystallographic, morphological, chemical and optical properties. Photocatalytic capacities of the pure BiOF/Bi{sub 2}O{sub 3} and BiOF/Bi{sub 2}O{sub 3}/RGO composites have been investigated by the degradation of Rhodamine B (RhB)-contained wastewater under natural sunlight irradiation. A twofold augmentation of degradation efficiency was in turn observed for BiOF/Bi{sub 2}O{sub 3}/RGO composites compared with that of pure BiOF/Bi{sub 2}O{sub 3} under the natural sunlight irradiation. The optimum conditions, the effects of the active species and stabilities in photocatalytic performances of the BiOF/Bi{sub 2}O{sub 3}/RGO composites have also been probed.

  15. Enthalpy-increment measurements for CsI(s) and Cs2CrO4(s) by high-temperature Calvet calorimetry

    International Nuclear Information System (INIS)

    Venugopal, V.; Agarwal, R.; Roy, K.N.; Prasad, R.; Sood, D.D.

    1987-01-01

    Molar thermodynamic properties of CsI(s) and Cs 2 Cr O 4 (s) have been evaluated by enthalpy-increment measurements, using a Calvet high-temperature calorimeter. Least squares analyses were performed on the enthalpy increment results. Data is presented in tabular form for the dependence of enthalpy increments on temperature, in the range 333 to 822 K, for both caesium compounds, along with the thermal properties of the compounds. Good agreement is found between the present data and previously reported results on reduced enthalpy increments of CsI(s) and Cs 2 CrO 4 (s). (U.K.)

  16. Tl, Bi, and Pb doping in Ba4BiPb2TlO12-δ

    International Nuclear Information System (INIS)

    Sutto, T.E.; Averill, B.A.

    1992-01-01

    To determine the effects of different 6s metal concentrations on the superconducting nature of Ba 4 BiPb 2 TlO 12-δ , materials produced via four doping schemes were examined: Ba 4 Bi(Pb, Tl) 3 O 12-δ , Ba 4 -(BiPb) 3 TlO 12-δ , Ba 4 (Bi,Tl) 2 Pb 2 O 12-δ , and Ba 4 Bi x Pb 4-2x Tl x O 12-δ . For the parent compound a value of δ = 0.91 was observed, indicating that approximately 1/4 oxygen atom was missing per cubic subsection of the unit cell. For all samples, the symmetry of the parent compound changed from orthorhombic to tetragonal as the system moved away from the ideal composition. This was usually accompanied by the loss of superconductivity, which exhibited a maximum T c of 10.5 K for the parent compound Ba 4 BiPb 2 TlO 12-δ . Also reported are high-temperature magnetic susceptibility results, which are used to determine the effect of metal substitution on the density of states at the Fermi level. For each set of variants on the parent composition, the onset of superconductivity was accompanied by a significant decrease in the size of the Pauli paramagnetic signal. 16 refs., 6 figs

  17. Considerations about using OLAP Cubes and Self-Service BI Tools for BI Systems’ Development

    Directory of Open Access Journals (Sweden)

    Gianina MIHAI

    2017-12-01

    Full Text Available Nowadays, the decision-making process must be an extremely fast one. This is why any decision-maker in a company must obtain information from the multiple available data source used in its transactional systems as easily and as quickly as possible. Business Intelligence (BI systems are the ones that provide the tools necessary for obtaining this information. In this article, we shall present the strengths and weaknesses regarding data analyses in a BI system using OLAP cubes and self-service BI tools.

  18. Uptake and release of {sup 134} Cs and {sup 137} Cs and iTs relation to {sup 40} K concentration in rats

    Energy Technology Data Exchange (ETDEWEB)

    Essa, M W.A.; Hussein, H H.M.; Abdelfattah, A T; Abdelbaky, W M [Nuclear research Center, Atomic Energy Authority, Cairo (Egypt)

    1997-12-31

    Studies were performed to examine the effect of a accumulation of {sup 134} Cs and Cs-137 on the concentration of K-40 in white rats. Five male and five female rats were fed with normal diet for four weeks. After that, the ten rats were fed with macaroni contaminated with Cs-134 (116 Bq/kg) and Cs-137 (318 Bq/kg) besides the normal diet. Animal whole body counting was done once weekly for four months using HPGe and multichannel analyzer. The results should that the uptake of cesium increases until saturation was reached after about one month to values 60,65 Bq/kg for Cs-134, and 200,240 Bq/kg for Cs-137. Results show a decrease in k-40 concentration due to the replacement of potassium ions by cesium ions in the cell. After saturation, feeding with radioactive diet was replaced by normal diet. A release of Cs-134 and Cs-137 was noticed with increase of K-40 concentration. 6 figs., 2 tabs.

  19. SEPARATION OF CsCl FROM LiCl-CsCl MOLTEN SALT BY COLD FINGER MELT CRYSTALLIZATION

    Directory of Open Access Journals (Sweden)

    JOSHUA R. VERSEY

    2014-06-01

    Full Text Available This study provides a fundamental understanding of a cold finger melt crystallization technique by exploring the heat and mass transfer processes of cold finger separation. A series of experiments were performed using a simplified LiCl-CsCl system by varying initial CsCl concentrations (1, 3, 5, and 7.5 wt%, cold finger cooling rates (7.4, 9.8, 12.3, and 14.9 L/min, and separation times (5, 10, 15, and 30 min. Results showed a potential recycling rate of 0.36 g/min with a purity of 0.33 wt% CsCl in LiCl. A CsCl concentrated drip formation was found to decrease crystal purity especially for smaller crystal formations. Dimensionless heat and mass transfer correlations showed that separation production is primarily influenced by convective transfer controlled by cooling gas flow rate, where correlations are more accurate for slower cooling gas flow rates.

  20. Bismuth oxychloride homogeneous phasejunction BiOCl/Bi12O17Cl2 with unselectively efficient photocatalytic activity and mechanism insight

    Science.gov (United States)

    Hao, Lin; Huang, Hongwei; Guo, Yuxi; Du, Xin; Zhang, Yihe

    2017-10-01

    Fabrication of homo/hetero-junctions by coupling of wide-band gap semiconductor and narrow-band gap semiconductor is desirable as they can achieve a decent balance between photoabsorption and photo-redox ability. Herein, a n-n type bismuth oxychloride homogeneous phasejunction BiOCl/Bi12O17Cl2 was developed by facilely manipulating the basicity in a one-pot hydrothermal process. Compared with BiOCl which only responds to UV light, the photo-responsive range is remarkably extended to visible region. The BiOCl/Bi12O17Cl2 phasejunctions show much higher photocatalytic activity than the single BiOCl and Bi12O17Cl2 toward degradation of methyl orange (MO) under simulated solar light. In particular, it presented a high photo-oxidation ability in degrading diverse industrial contaminants including 2,4-dichlorophenol (2,4-DCP), phenol, bisphenol A (BPA) and tetracycline hydrochloride. Based on a series of photoelectrochemical and photoluminescence measurements, the fortified photocatalytic performance of BiOCl/Bi12O17Cl2 phasejunctions was manifested to be attributed to the efficient separation and transfer efficiencies of photoinduced electron-hole pairs because of the junctional interface formed between BiOCl and Bi12O17Cl2. The study may not only furnish a high-effective photocatalyst in the application of environment purification, but also pave a path to fabricate agnate phase-junctional photocatalyst.

  1. Thermal analysis and phase diagrams of the LiF BiF3 e NaF BiF3 systems

    International Nuclear Information System (INIS)

    Nakamura, Gerson Hiroshi de Godoy

    2013-01-01

    Investigations of the binary systems LiF-BiF 3 and NaF-BiF 3 were performed with the objective of clarifying the thermal behavior and phase equilibria of these systems and their intermediary phases, an important requisite for high-quality crystal growth. Several samples in the entire range of compositions (0 to 100 mol% BiF 3 ) of both systems were subjected to experiments of differential thermal analysis (DTA) and thermogravimetry (TG), and also of differential scanning calorimetry (DSC). A few specific compositions were selected for X-ray diffraction to supplement the experimental data. Due to the high vulnerability of BiF 3 to oxygen contamination, its volatility and propensity to destroy metal parts upon heating, it was necessary to determine the optimal conditions for thermal analysis before investigating the systems themselves. Phase relations in the system LiF-BiF 3 were completely clarified and a phase diagram was calculated and evaluated via the commercial software Factsage. The diagram itself consists in a simple peritectic system in which the only intermediary compound, LiBiF 4 , decomposes into LiF and a liquid phase. The NaF-BiF 3 system could not be completely elucidated and the phase relations in the NaF poor side (> 50% BiF 3 ) are still unknown. In the NaF rich side, however, the possible peritectoid decomposition of the compound NaBiF 4 was identified. In both systems X-ray diffraction yielded crystal structures discrepant with the literature for the intermediary phases, LiBiF 4 , NaBiF 4 and a solid solution of NaF and BiF 3 called I. The observed structures remain unknown and explanations for the discrepancies were proposed. (author)

  2. Solution-Grown CsPbBr3 /Cs4 PbBr6 Perovskite Nanocomposites: Toward Temperature-Insensitive Optical Gain.

    Science.gov (United States)

    Wang, Yue; Yu, Dejian; Wang, Zeng; Li, Xiaoming; Chen, Xiaoxuan; Nalla, Venkatram; Zeng, Haibo; Sun, Handong

    2017-09-01

    With regards to developing miniaturized coherent light sources, the temperature-insensitivity in gain spectrum and threshold is highly desirable. Quantum dots (QDs) are predicted to possess a temperature-insensitive threshold by virtue of the separated electronic states; however, it is never observed in colloidal QDs due to the poor thermal stability. Besides, for the classical II-VI QDs, the gain profile generally redshifts with increasing temperature, plaguing the device chromaticity. Herein, this paper addresses the above two issues simultaneously by embedding ligands-free CsPbBr 3 nanocrystals in a wider band gap Cs 4 PbBr 6 matrix by solution-phase synthesis. The unique electronic structures of CsPbBr 3 nanocrystals enable temperature-insensitive gain spectrum while the lack of ligands and protection from Cs 4 PbBr 6 matrix ensure the thermal stability and high temperature operation. Specifically, a color drift-free stimulated emission irrespective of temperature change (20-150 °C) upon two-photon pumping is presented and the characteristic temperature is determined to be as high as ≈260 K. The superior gain properties of the CsPbBr 3 /Cs 4 PbBr 6 perovskite nanocomposites are directly validated by a vertical cavity surface emitting laser operating at temperature as high as 100 °C. The results shed light on manipulating optical gain from the advantageous CsPbBr 3 nanocrystals and represent a significant step toward the temperature-insensitive frequency-upconverted lasers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Cs-137 migration in soil near NPPs

    International Nuclear Information System (INIS)

    Silant'ev, A.N.; Shkuratova, I.G.; Khatskevich, R.N.

    1984-01-01

    A convective-diffusion model has been employed for describing Cs-137 migration in soil. The migration parameters were determined by comparing the calculated vertical distribution profiles with the experimental ones. The migration parameters dependence on the soil state has been studied. Cs-137 penetration rate was found to be function of the soil type, surface state, soil wetness and orography. The obtained values are presented. A method is suggested for revealing the soil surface contamination by Cs-137 produced during NPP operation with distinguishing it from the global contamination background. For this purpose Cs-137 content in the upper 5 mm soil layer is estimated [ru

  4. Ultrahigh vacuum STM/STS studies of the Bi-O surface in Bi2Sr2CuOy single crystals

    International Nuclear Information System (INIS)

    Ikeda, Kazuto; Tomeno, Izumi; Takamuku, Kenshi; Yamaguchi, Koji; Itti, Rittaporn; Koshizuka, Naoki

    1992-01-01

    Scanning tunneling microscopic and spectroscopic studies were made on cleaved surfaces of Bi 2 Sr 2 CuO y single crystals using an ultrahigh-vacuum scanning tunneling microscope (UHV-STM). The modulation structures of the Bi-O surface were observed at room temperature with atomic resolution. The tunneling spectra showed electronic gap structures similar to those observed for the Bi-O surface of superconducting Bi-2212 single crystals. This suggests that superconductivity is not directly related to the electronic structure observed in the Bi-O plane. (orig.)

  5. Is 137Cs Dating Becoming Obsolete in North America?

    Science.gov (United States)

    Drexler, J. Z.; Fuller, C.; Salas, A.

    2016-12-01

    Dating of wetland sediments and peat is routinely carried out using 137Cs and 210Pb analysis. Unlike 210Pb, 137Cs is an anthropogenic radionuclide with a history of fallout from nuclear weapons testing. 137Cs is used as a single time marker; its peak is coincident with the height of atmospheric nuclear testing in 1963/4. During its use in the 1970s-90s, 137Cs peaks were usually highly distinct in wetland sediments (e.g., see 137Cs peaks from Louisiana marshes in Feijtel et al., 1988). This enabled its use as a check for dates assigned to a profile by 210Pb and other methods. However, recently, the efficacy of 137Cs dating in North America has deteriorated. In this presentation, we will provide specific examples of 137Cs as well as 210Pb dating in wetland sediments/peats we collected between 2005 and 2015 in Maine, California, Virginia, North Carolina, South Carolina, and Washington. Two main reasons exist for this decline. First, 137Cs activities in our recent cores are 30-40 % of the original activities in 1963/4 due to decay of the original 137Cs in situ (half-life = 30.17 years) and no major new sources. This manifests in lower signal to noise ratio, with some peaks barely recognizable above the noise. Second, 137Cs peaks are much less distinct due to 137Cs migration through time independent of substrate (or sediment) particles. Migration of peaks has resulted in estimated accretion rates being systematically lower or higher than those derived from 210Pb dating. These issues with 137Cs dating have important implications because 137Cs is used with 210Pb dating or even alone to determine rates of recent wetland carbon accumulation. Such rates are required to enter wetland restoration projects into carbon markets and to document IPCC mandated reductions in carbon pollution. Our analysis shows that, although dating by 137Cs alone has always been highly tenuous, now it is especially contraindicated and should be disallowed for the purposes of carbon accounting.

  6. Annealing-Induced Bi Bilayer on Bi2Te3 Investigated via Quasi-Particle-Interference Mapping.

    Science.gov (United States)

    Schouteden, Koen; Govaerts, Kirsten; Debehets, Jolien; Thupakula, Umamahesh; Chen, Taishi; Li, Zhe; Netsou, Asteriona; Song, Fengqi; Lamoen, Dirk; Van Haesendonck, Chris; Partoens, Bart; Park, Kyungwha

    2016-09-27

    Topological insulators (TIs) are renowned for their exotic topological surface states (TSSs) that reside in the top atomic layers, and hence, detailed knowledge of the surface top atomic layers is of utmost importance. Here we present the remarkable morphology changes of Bi2Te3 surfaces, which have been freshly cleaved in air, upon subsequent systematic annealing in ultrahigh vacuum and the resulting effects on the local and area-averaging electronic properties of the surface states, which are investigated by combining scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), and Auger electron spectroscopy (AES) experiments with density functional theory (DFT) calculations. Our findings demonstrate that the annealing induces the formation of a Bi bilayer atop the Bi2Te3 surface. The adlayer results in n-type doping, and the atomic defects act as scattering centers of the TSS electrons. We also investigated the annealing-induced Bi bilayer surface on Bi2Te3 via voltage-dependent quasi-particle-interference (QPI) mapping of the surface local density of states and via comparison with the calculated constant-energy contours and QPI patterns. We observed closed hexagonal patterns in the Fourier transform of real-space QPI maps with secondary outer spikes. DFT calculations attribute these complex QPI patterns to the appearance of a "second" cone due to the surface charge transfer between the Bi bilayer and the Bi2Te3. Annealing in ultrahigh vacuum offers a facile route for tuning of the topological properties and may yield similar results for other topological materials.

  7. An optical microscopy study of the swelling of wet-spun films of CsDNA as a function of hydration and CsCl concentration

    Science.gov (United States)

    Schwenker, Megan; Marlowe, Robert; Lee, Scott; Rupprecht, Allan

    2005-03-01

    Highly oriented, wet-spun films of DNA expand in the direction perpendicular to the helical axis as the hydration of the film is increased. CsDNA films with a high CsCl content show an unexpected shrinkage at a relative humidity of 92%. Our most recent experiments have been to measure the perpendicular dimension of CsDNA as a function of both hydration and concentration of CsCl. Our preliminary results show that no shrinkage is observed at low contents of CsCl, showing that the CsCl plays an integral role in the shrinkage phenomenon.

  8. 137Cs in the western South Pacific Ocean

    International Nuclear Information System (INIS)

    Yamada, Masatoshi; Wang Zhongliang

    2007-01-01

    The 137 Cs activities were determined for seawater samples from the East Caroline, Coral Sea, New Hebrides, South Fiji and Tasman Sea (two stations) Basins of the western South Pacific Ocean by γ spectrometry using a low background Ge detector. The 137 Cs activities ranged from 1.4 to 2.3 Bq m -3 over the depth interval 0-250 m and decreased exponentially from the subsurface to 1000 m depth. The distribution profiles of 137 Cs activity at these six western South Pacific Ocean stations did not differ from each other significantly. There was a remarkable difference for the vertical profiles of 137 Cs activity between the East Caroline Basin station in this study and the GEOSECS (Geochemical Ocean Sections Study) station at the same latitude in the Equatorial Pacific Ocean; the 137 Cs inventory over the depth interval 100-1000 m increased from 400 ± 30 Bq m -2 to 560 ± 30 Bq m -2 during the period from 1973 to 1992. The total 137 Cs inventories in the western South Pacific Ocean ranged from 850 ± 70 Bq m -2 in the Coral Sea Basin to 1270 ± 90 Bq m -2 in the South Fiji Basin. Higher 137 Cs inventories were observed at middle latitude stations in the subtropical gyre than at low latitude stations. The 137 Cs inventories were 1.9-4.5 times (2.9 ± 0.7 on average) and 1.7-4.3 times (3.1 ± 0.7 on average) higher than that of the expected deposition density of atmospheric global fallout at the same latitude and that of the estimated 137 Cs deposition density in 10 o latitude by 10 deg. longitude grid data obtained by Aoyama et al. [Aoyama M, Hirose K, Igarashi Y. Re-construction and updating our understanding on the global weapons tests 137 Cs fallout. J Environ Monit 2006;8:431-438], respectively. The possible processes for higher 137 Cs inventories in the western South Pacific Ocean than that of the expected deposition density of atmospheric global fallout may be attributable to the inter-hemisphere dispersion of the atmospheric nuclear weapons testing 137 Cs from

  9. Phase relations and crystal structures in the systems (Bi,Ln)2WO6 and (Bi,Ln)2MoO6 (Ln=lanthanide)

    International Nuclear Information System (INIS)

    Berdonosov, Peter S.; Charkin, Dmitri O.; Knight, Kevin S.; Johnston, Karen E.; Goff, Richard J.; Dolgikh, Valeriy A.; Lightfoot, Philip

    2006-01-01

    Several outstanding aspects of phase behaviour in the systems (Bi,Ln) 2 WO 6 and (Bi,Ln) 2 MoO 6 (Ln=lanthanide) have been clarified. Detailed crystal structures, from Rietveld refinement of powder neutron diffraction data, are provided for Bi 1.8 La 0.2 WO 6 (L-Bi 2 WO 6 type) and BiLaWO 6 , BiNdWO 6 , Bi 0.7 Yb 1.3 WO 6 and Bi 0.7 Yb 1.3 WO 6 (all H-Bi 2 WO 6 type). Phase evolution within the solid solution Bi 2- x La x MoO 6 has been re-examined, and a crossover from γ(H)-Bi 2 MoO 6 type to γ-R 2 MoO 6 type is observed at x∼1.2. A preliminary X-ray Rietveld refinement of the line phase BiNdMoO 6 has confirmed the α-R 2 MoO 6 type structure, with a possible partial ordering of Bi/Nd over the three crystallographically distinct R sites. - Graphical abstract: A summary of phase relations in the lanthanide-doped bismuth tungstate and bismuth molybdate systems is presented, together with some additional structural data on several of these phases

  10. Fuzzy Bi-level Decision-Making Techniques: A Survey

    Directory of Open Access Journals (Sweden)

    Guangquan Zhang

    2016-04-01

    Full Text Available Bi-level decision-making techniques aim to deal with decentralized management problems that feature interactive decision entities distributed throughout a bi-level hierarchy. A challenge in handling bi-level decision problems is that various uncertainties naturally appear in decision-making process. Significant efforts have been devoted that fuzzy set techniques can be used to effectively deal with uncertain issues in bi-level decision-making, known as fuzzy bi-level decision-making techniques, and researchers have successfully gained experience in this area. It is thus vital that an instructive review of current trends in this area should be conducted, not only of the theoretical research but also the practical developments. This paper systematically reviews up-to-date fuzzy bi-level decisionmaking techniques, including models, approaches, algorithms and systems. It also clusters related technique developments into four main categories: basic fuzzy bi-level decision-making, fuzzy bi-level decision-making with multiple optima, fuzzy random bi-level decision-making, and the applications of bi-level decision-making techniques in different domains. By providing state-of-the-art knowledge, this survey paper will directly support researchers and practitioners in their understanding of developments in theoretical research results and applications in relation to fuzzy bi-level decision-making techniques.

  11. A plate-on-plate sandwiched Z-scheme heterojunction photocatalyst: BiOBr-Bi{sub 2}MoO{sub 6} with enhanced photocatalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shengyao [College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Environment Correlative Dietology, Ministry of Education, Wuhan 430070 (China); Yang, Xianglong; Zhang, Xuehao; Ding, Xing; Yang, Zixin [College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Dai, Ke [College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Chen, Hao, E-mail: hchenhao@mail.hzau.edu.cn [College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Environment Correlative Dietology, Ministry of Education, Wuhan 430070 (China)

    2017-01-01

    Highlights: • A visible light heterojunction photocatalyst of BiOBr-Bi{sub 2}MoO{sub 6} was simply synthesized. • Carriers transferred efficiently in sandwiched layers causing an enhance activity. • A possible direct Z-scheme charge transfer mechanism of BiOBr-Bi2MoO6 is proposed. - Abstract: In this study, a direct Z-scheme heterojunction BiOBr-Bi{sub 2}MoO{sub 6} with greatly enhanced visible light photocatalytic performance was fabricated via a two-step coprecipitation method. It was indicated that a plate-on-plate heterojunctions be present between BiOBr and Bi{sub 2}MoO{sub 6} through different characterization techniques including X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectroscopy (DRS) and photoelectrochemical measurements. The crystal structure and morphology analysis revealed that the heterointerface in BiOBr-Bi{sub 2}MoO{sub 6} occurred mainly on the (001) facets of BiOBr and (001) facets of Bi{sub 2}MoO{sub 6}. The photocatalytic activity of the BiOBr-Bi{sub 2}MoO{sub 6} was investigated by degradation of RhB and about 66.7% total organic carbon (TOC) could be removed. Ciprofloxacin (CIP) was employed to rule out the photosensitization. It was implied that the higher activity of BiOBr-Bi{sub 2}MoO{sub 6} could be attribute to the strong redox ability in the Z-scheme system, which was subsequently confirmed by photoluminescence spectroscopy (PL) and active spices trapping experiments. This study provides a promising platform for Z-scheme heterojunction constructing and also sheds light on highly efficient visible-light-driven photocatalysts designing.

  12. Separation of top and bottom surface conduction in Bi2Te3 thin films

    International Nuclear Information System (INIS)

    Yu Xinxin; He Liang; Lang Murong; Jiang Wanjun; Kou Xufeng; Tang Jianshi; Huang Guan; Wang, Kang L; Xiu Faxian; Liao Zhiming; Zou Jin; Wang Yong; Zhang Peng

    2013-01-01

    Quantum spin Hall (QSH) systems are insulating in the bulk with gapless edges or surfaces that are topologically protected and immune to nonmagnetic impurities or geometric perturbations. Although the QSH effect has been realized in the HgTe/CdTe system, it has not been accomplished in normal 3D topological insulators. In this work, we demonstrate a separation of two surface conductions (top/bottom) in epitaxially grown Bi 2 Te 3 thin films through gate dependent Shubnikov–de Haas (SdH) oscillations. By sweeping the gate voltage, only the Fermi level of the top surface is tuned while that of the bottom surface remains unchanged due to strong electric field screening effects arising from the high dielectric constant of Bi 2 Te 3 . In addition, the bulk conduction can be modulated from n- to p-type with a varying gate bias. Our results on the surface control hence pave a way for the realization of QSH effect in topological insulators which requires a selective control of spin transports on the top/bottom surfaces. (paper)

  13. DIALIGN: multiple DNA and protein sequence alignment at BiBiServ.

    OpenAIRE

    Morgenstern, Burkhard

    2004-01-01

    DIALIGN is a widely used software tool for multiple DNA and protein sequence alignment. The program combines local and global alignment features and can therefore be applied to sequence data that cannot be correctly aligned by more traditional approaches. DIALIGN is available online through Bielefeld Bioinformatics Server (BiBiServ). The downloadable version of the program offers several new program features. To compare the output of different alignment programs, we developed the program AltA...

  14. [sup 205]Bi/[sup 206]Bi cyclotron production from Pb-isotopes for absorption studies in humans

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, R.; Dresow, B.; Heinrich, H.C. (Universitaetskrankenhaus Eppendorf, Hamburg (Germany). Abt. Medizinische Biochemie); Wendel, J.; Bechtold, V. (Kernforschungszentrum Karlsruhe GmbH (Germany). Inst. fuer Kernphysik)

    1993-12-01

    Pb(p,xn) thick target excitation functions were measured in the energy range 10-38 MeV in order to optimize the production of isotopically pure radiobismuth from [sup nat]Pb, [sup 206]Pb, and [sup 207]Pb. Additionally, the decay of Po-isotopes from deuteron irradiation of natural bismuth ([sup 209]Bi) was exploited for radiobismuth production. [sup 205]Bi was produced from [sup 206]Pb at 20 MeV with only 2% of [sup 206]Bi at 4 weeks post irradiation. Bismuth compounds as used in the treatment of peptic ulcer were labeled with [sup 205]Bi for absorption studies in animals and subjects. (Author).

  15. A viral long terminal repeat expressed in CD4+CD8+ precursors is downregulated in mature peripheral CD4-CD8+ or CD4+CD8- T cells.

    OpenAIRE

    Paquette, Y; Doyon, L; Laperrière, A; Hanna, Z; Ball, J; Sekaly, R P; Jolicoeur, P

    1992-01-01

    The long terminal repeat from a thymotropic mouse mammary tumor virus variant, DMBA-LV, was used to drive the expression of two reporter genes, murine c-myc and human CD4, in transgenic mice. Expression was observed specifically in thymic immature cells. Expression of c-myc in these cells induced oligoclonal CD4+ CD8+ T-cell thymomas. Expression of human CD4 was restricted to thymic progenitor CD4- CD8- and CD4+ CD8+ T cells and was shut off in mature CD4+ CD8- and CD4- CD8+ T cells, known to...

  16. Measurement of 137Cs activity in living chicken

    International Nuclear Information System (INIS)

    Balas, J.; Poeschl, M.

    1998-01-01

    The possibility of measuring the 137 Cs activity in broiler chickens in vivo was examined. The experiment was conducted with broiler chickens 7 to 22 days old (White Leghorn hybrid, race ISA VEDETTE). Three oral doses of 137 Cs (total activity 5 kBq/chicken) were administered during a day (at 8:00, 12:00 and 16:00). The radioactivity was determined by gamma spectroscopy with a stabilised Nal/Tl detector. The measurement was carried out on days 1, 2, 3, 4, 7, 8, 14 and 15 after the 137 Cs administration in vivo. The detector was put closely to the body in the area of breast muscles. The radiocesium activity concentrations in fresh daily excreta were also determined. A rapid uptake of the orally administered 137 Cs (within a few hours) as well as a rapid loss of radiocesium were observed. The dynamics and accuracy of the in vivo measurement of 137 Cs activity were comparable with the recently published results of in vitro measurement of radiocesium activity. Only the initial 137 Cs activity (during 2 days after 137 Cs application) was higher with regard to the content of contaminated feed mixture in the gastrointestinal tract

  17. A simple preparation of calibration curve standards of 134Cs and 137Cs by serial dilution of a standard reference material

    International Nuclear Information System (INIS)

    Labrecque, J.J.; Rosales, P.A.

    1990-01-01

    Two sets of calibration standards for 134 Cs and 137 Cs were prepared by small serial dilution of a natural matrix standard reference material, IAEA-154 whey powder. The first set was intended to screen imported milk powders which were suspected to be contaminated with 134 Cs and 137 Cs. Their concentration ranged from 40 to 400 Bq/kg. The other set of calibration standards was prepared to measure the environmental levels of 137 Cs in commercial Venezuelan milk powders. Their concentration ranged from 3 to 10 Bq/kg of 137 Cs. The accuracy of these calibration curves was checked by IAEA-152 and A-14 milk powders. Their measured values were in good agreement with their certified values. Finally, it is shown that these preparation techniques using serial dilution of a standard reference material were simple, rapid, precise, accurate and cost-effective. (author) 5 refs.; 5 figs.; 3 tabs

  18. Characterization of a pixelated CdTe Timepix detector operated in ToT mode

    International Nuclear Information System (INIS)

    Billoud, T.; Leroy, C.; Papadatos, C.; Roux, J.S.; Pichotka, M.; Pospisil, S.

    2017-01-01

    A 1 mm thick CdTe sensor bump-bonded to a Timepix readout chip operating in Time-over-Threshold (ToT) mode has been characterized in view of possible applications in particle and medical physics. The CdTe sensor layer was segmented into 256 × 256 pixels, with a pixel pitch of 55  μm. This CdTe Timepix device, of ohmic contact type, has been exposed to alpha-particles and photons from an 241 Am source, photons from a 137 Cs source, and protons of different energies (0.8–10 MeV) delivered by the University of Montreal Tandem Accelerator. The device was irradiated on the negatively biased backside electrode. An X-ray per-pixel calibration commonly used for this type of detector was done and its accuracy and resolution were assessed and compared to those of a 300  μm thick silicon Timepix device. The electron mobility-lifetime product (μ e τ e ) of CdTe for protons of low energy has been obtained from the Hecht equation. Possible polarization effects have been also investigated. Finally, information about the homogeneity of the detector was obtained from X-ray irradiation.

  19. A smart pH-responsive nano-carrier as a drug delivery system for the targeted delivery of ursolic acid: suppresses cancer growth and metastasis by modulating P53/MMP-9/PTEN/CD44 mediated multiple signaling pathways.

    Science.gov (United States)

    Jiang, Kai; Chi, Ting; Li, Tao; Zheng, Guirong; Fan, Lulu; Liu, Yajun; Chen, Xiufen; Chen, Sijia; Jia, Lee; Shao, Jingwei

    2017-07-13

    Ursolic acid (UA) has been recently used as a promising anti-tumor and cancer metastatic chemo-preventive agent due to its low toxicity and liver-protecting property. However, the low bioavailability and nonspecific tumor targeting restrict its further clinical application. To address the problem, a silica-based mesoporous nanosphere (MSN) controlled-release drug delivery system (denoted UA@M-CS-FA) was designed and successfully synthesized, and was functionalized with folic acid (FA) and pH-sensitive chitosan (CS) for the targeted delivery of UA to folate receptor (FR) positive tumor cells. UA@M-CS-FA were spherical with mean diameter below 150 nm, and showed about -20 mV potential. Meanwhile, UA@M-CS-FA exhibited a pH-sensitive release manner and high cellular uptake in FR over-expressing HeLa cancer cells. Also, in vitro cellular assays suggested that UA@M-CS-FA inhibited cancer cell growth, invasion and migration. Mechanistically, UA@M-CS-FA induced cancer cell apoptosis and inhibited migration via cell cycle arrest in the G0/G1 stage, regulating the PARP/Bcl-2/MMP-9/CD44/PTEN/P53. Importantly, in vivo experiments further confirmed that UA@M-CS-FA significantly suppressed the tumor progression and lung metastasis in tumor-bearing nude mice. Immunohistochemical analysis revealed that UA@M-CS-FA treatment regulated CD44, a biomarker of cancer metastasis. Overall, our data demonstrated that a CS and FA modified MSN controlled-release drug delivery system could help broaden the usage of UA and reflect the great application potential of the UA as an anticancer or cancer metastatic chemopreventive agent.

  20. Advanced processing of CdTe pixel radiation detectors

    Science.gov (United States)

    Gädda, A.; Winkler, A.; Ott, J.; Härkönen, J.; Karadzhinova-Ferrer, A.; Koponen, P.; Luukka, P.; Tikkanen, J.; Vähänen, S.

    2017-12-01

    We report a fabrication process of pixel detectors made of bulk cadmium telluride (CdTe) crystals. Prior to processing, the quality and defect density in CdTe material was characterized by infrared (IR) spectroscopy. The semiconductor detector and Flip-Chip (FC) interconnection processing was carried out in the clean room premises of Micronova Nanofabrication Centre in Espoo, Finland. The chip scale processes consist of the aluminum oxide (Al2O3) low temperature thermal Atomic Layer Deposition (ALD), titanium tungsten (TiW) metal sputtering depositions and an electroless Nickel growth. CdTe crystals with the size of 10×10×0.5 mm3 were patterned with several photo-lithography techniques. In this study, gold (Au) was chosen as the material for the wettable Under Bump Metalization (UBM) pads. Indium (In) based solder bumps were grown on PSI46dig read out chips (ROC) having 4160 pixels within an area of 1 cm2. CdTe sensor and ROC were hybridized using a low temperature flip-chip (FC) interconnection technique. The In-Au cold weld bonding connections were successfully connecting both elements. After the processing the detector packages were wire bonded into associated read out electronics. The pixel detectors were tested at the premises of Finnish Radiation Safety Authority (STUK). During the measurement campaign, the modules were tested by exposure to a 137Cs source of 1.5 TBq for 8 minutes. We detected at the room temperature a photopeak at 662 keV with about 2 % energy resolution.

  1. Seperation of CsCl from LiCl-CsCl molten salt by cold finger melt cryst allization

    Energy Technology Data Exchange (ETDEWEB)

    Versey, Joshua R. [Dept. of Chemical and Materials Engineering and Nuclear Engineering Program University of Idaho, Idaho (United States); Phongikaroon, Supathorn [Dept. of Mechanical and Nuclear Engineering Virginia Commonwealth University, Richmond (Korea, Republic of); Simpson, Michael F. [Dept. of Metallurgical Engineering University of Utah, Utah (Korea, Republic of)

    2014-06-15

    This study provides a fundamental understanding of a cold finger melt crystallization technique by exploring the heat and mass transfer processes of cold finger separation. A series of experiments were performed using a simplified LiCl-CsCl system by varying initial CsCl concentrations (1, 3, 5, and 7.5 wt%), cold finger cooling rates (7.4, 9.8, 12.3, and 14.9 L/min), and separation times (5, 10, 15, and 30 min). Results showed a potential recycling rate of 0.36 g/min with a purity of 0.33 wt% CsCl in LiCl. A CsCl concentrated drip formation was found to decrease crystal purity especially for smaller crystal formations. Dimensionless heat and mass transfer correlations showed that separation production is primarily influenced by convective transfer controlled by cooling gas flow rate, where correlations are more accurate for slower cooling gas flow rates.

  2. Calorimetric investigation of Pb-Bi system

    International Nuclear Information System (INIS)

    Agarwal, Renu; Jat, Ram Avtar; Sen, B.K.

    2008-01-01

    Enthalpy increment of Pb 0.71 Bi 0.29 compound was determined using high temperature Calvet calorimeter. The data was fit into the following polynomial equation. ΔH(T-298.15 K) J/mol = -10384.96 + 39.23 T - 0.014T 2 - 18970/T. By precipitation method, the enthalpy of formation of the compound of composition Pb 0.68 Bi 0.32 at 448 K, from Pb(l) and Bi(l) was determined to be -2450± 50 J/mol and from Pb(s) and Bi(s) at 298.15 K was calculated to be 4047 J/mol. (author)

  3. X-ray standing wave study of the Bi/GaAs and Bi/GaP interfaces

    International Nuclear Information System (INIS)

    Herrera-Gomez, A.

    1994-04-01

    Interfaces are one of the most important elements determining the characteristics of electronic devices. Composite semiconductors, specifically the III-V family, are technologically attractive because of their mobility and optical properties, and also because they offer the possibility of engineering such properties as the size of the band gap. Nevertheless, Si has remained the most utilized semiconductor material, primarily because the fabrication of practical MOSFETs with III-V semiconductors remains elusive. Examples of such complex interfaces are the structures formed by one monolayer of Bi on the (110) surface of GaAs and GaP. While better matched Column V elements form epitaxial continuous monolayers on III-V semiconductor (110) surfaces, Bi is too large to accommodate on GaAs and GaP surfaces with long range order, and vacancies appear to allow relaxation. For the ideal systems, symmetry imposes the presence of only two nonequivalent adatom sites. However, for Bi/GaAs and Bi/GaP, more than two different sites are present because the position of Bi atoms next to a vacancy is not necessarily equivalent to that between other Bi atoms. The geometry of the Bi/GaAs and Bi/GaP systems was determined here by triangulating XSW results from three Bragg planes. A methodology was developed that provides an intrinsic check of the validity of assuming two sites for the overlayer structures. An experimental method was developed that allows the three reflections to be measured on the same sample, thus reducing the number of experimental variables, such as the degree of disorder. The traditional method of analysis was not accurate enough for this data, so a more reliable and faster method of data fitting was developed. A configuration used in the present work, which previously has been widely used, presents an intrinsic multireflection problem. This issue is discussed in depth, and the appropriate method is determined for analyzing the data obtained with this configuration

  4. Fractionation of (137)Cs and Pu in natural peatland.

    Science.gov (United States)

    Mihalík, Ján; Bartusková, Miluše; Hölgye, Zoltán; Ježková, Tereza; Henych, Ondřej

    2014-08-01

    High Cs-137 concentrations in plants growing on peatland inspired us to investigate the quantity of its bioavailable fraction in natural peat. Our investigation aims to: a) estimate the quantity of bioavailable Cs-137 and Pu present in peat, b) verify the similarity of Cs-137 and K-40 behaviours, and c) perform a quantification of Cs-137 and Pu transfer from peat to plants. We analysed the vertical distribution of Cs-137 and Pu isotopes in the peat and their concentrations in plants growing on these places. Bioavailability of radionuclides was investigated by sequential extraction. Sequential analyses revealed that it was the upper layer which contained the majority of Cs-137 in an available form while deeper layers retained Cs-137 in immobile fractions. We can conclude that 18% of all Cs-137 in the peat is still bioavailable. Despite of the low quantity of bioavailable fraction of Cs-137 its transfer factor reached extremely high values. In the case of Pu, 64% of its total amount was associated with fulvic/humic acids which resulted in the high transfer factor from peat to plants. 27 years after the Chernobyl nuclear accident, the significant part of radionuclides deposited in peatland is still bioavailable. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Regulatory function of cytomegalovirus-specific CD4+CD27-CD28- T cells

    International Nuclear Information System (INIS)

    Tovar-Salazar, Adriana; Patterson-Bartlett, Julie; Jesser, Renee; Weinberg, Adriana

    2010-01-01

    CMV infection is characterized by high of frequencies of CD27 - CD28 - T cells. Here we demonstrate that CMV-specific CD4 + CD27 - CD28 - cells are regulatory T cells (T R ). CD4 + CD27 - CD28 - cells sorted from CMV-stimulated PBMC of CMV-seropositive donors inhibited de novo CMV-specific proliferation of autologous PBMC in a dose-dependent fashion. Compared with the entire CMV-stimulated CD4 + T-cell population, higher proportions of CD4 + CD27 - CD28 - T R expressed FoxP3, TGFβ, granzyme B, perforin, GITR and PD-1, lower proportions expressed CD127 and PD1-L and similar proportions expressed CD25, CTLA4, Fas-L and GITR-L. CMV-CD4 + CD27 - CD28 - T R expanded in response to IL-2, but not to CMV antigenic restimulation. The anti-proliferative effect of CMV-CD4 + CD27 - CD28 - T R significantly decreased after granzyme B or TGFβ inhibition. The CMV-CD4 + CD27 - CD28 - T R of HIV-infected and uninfected donors had similar phenotypes and anti-proliferative potency, but HIV-infected individuals had higher proportions of CMV-CD4 + CD27 - CD28 - T R . The CMV-CD4 + CD27 - CD28 - T R may contribute to the downregulation of CMV-specific and nonspecific immune responses of CMV-infected individuals.

  6. Cs0.49NbPS6

    Directory of Open Access Journals (Sweden)

    Hoseop Yun

    2011-01-01

    Full Text Available The quaternary thiophosphate, Cs0.49NbPS6, caesium hexathioniobiophosphate(V, has been synthesized by the reactive halide flux method. The title compound is isotypic with Rb0.46TaPS6 and is made up of a bicapped trigonal–biprismatic [Nb2S12] unit and a tetrahedral [PS4] group. The [Nb2S12] units linked by the [PS4] tetrahedra form infinite chains, yielding a three-dimensional network with rather large van der Waals gaps along the c axis in which the disordered Cs+ ions reside. The electrons released by the Cs atoms are transferred to the pairwise niobium metal site and there are substantial intermetallic Nb—Nb bonding interactions. This leads to a significant decrease of the intermetallic distance in the title compound compared to that in TaPS6. The classical charge balance of the title compound may be represented as [Cs+]0.49[Nb4.51+][P5+][S2−]4[S22−].

  7. Structural properties of Bi2O3–B2O3–SiO2–Na2O glasses for gamma ray shielding applications

    International Nuclear Information System (INIS)

    Kaur, Kulwinder; Singh, K.J.; Anand, Vikas

    2016-01-01

    Glass samples of the xBi 2 O 3 –(0.70−x)B 2 O 3 –0.15SiO 2 –0.15Na 2 O (where x=0 up to 0.5 mol fraction) have been prepared in the laboratory by using melt quenching technique. 137 Cs source has been used for experimental measurements of mass attenuation coefficient of γ-rays at 662 keV. Mass attenuation coefficient of our glass samples has been compared with standard nuclear radiation shield “barite concrete”. It has been concluded that bismuth containing glass samples can be potential candidates for γ-ray shielding applications. Glasses must have appreciable elastic moduli values for their practical utility as γ-ray shields which are related to coordination number and non-bridging oxygens. Structural properties including coordination number and non-bridging oxygens of the structural units of the glass system have been estimated from the detailed analysis of Optical, Raman and FTIR spectra. Reported investigations can contribute to the development of transparent gamma ray shields. - Highlights: • Bi containing samples can be potential candidates as γ-ray shielding materials. • Number of non-bridging oxygens increases with the increase in the content of Bi 2 O 3 . • Coordination number of boron decreases with increase in the content of Bi 2 O 3 .

  8. High Contrast Coherent Population Trapping Resonances in Cs Vapour Cells with a Simple-Architecture Laser System

    International Nuclear Information System (INIS)

    Liu, Xiaochi

    2013-01-01

    This thesis reports the development of a simple-architecture laser system resonant at 895 nm used for the detection of high-contrast coherent population trapping (CPT) resonances in Cs vapor cells. The laser system combines a distributed feedback-diode (DFB) laser, a pigtailed Mach-Zehnder intensity electro-optic modulator (EOM) driven at 4.596 GHz for the generation of optical sidebands frequency-split by 9.192 GHz and a Michelson delay-line system to produce a bi-chromatic optical field that alternates between right and left circular polarization. This polarization pumping scheme, first proposed by Happer's group in Princeton on K atoms, allows to optically pump a maximum number of Cs atoms into the 0-0 magnetic field insensitive clock transition. Advanced noise reduction techniques were implemented in order to stabilize the laser power, the optical carrier suppression at the output of the EOM and the DFB laser frequency. Using this system, we demonstrated the detection of CPT resonances with a contrast of 80% in cm-scale Cs vapor cells. This contrast was measured to be increased until a saturation effect with the laser power at the expense of the CPT line broadening. To circumvent this issue, we proposed with a simple setup Ramsey spectroscopy of CPT resonances in vapor cells to combine high-contrast and narrow line width of the CPT resonances. In this setup, the EOM is used both for optical sidebands generation and light switch to produce Ramsey interaction. Ramsey fringes of 166 Hz line width with a contrast better than 30% were detected with this setup. This laser system will be in a near future devoted to be used for the development of a high-performance CPT-based atomic clock. (author)

  9. Uptake and distribution of 137Cs and stable Cs by microorganisms isolated from mushroom substrata in the Japanese forests

    International Nuclear Information System (INIS)

    Kuwahara, Chikako; Fukumoto, Atsushi; Kato, Fumio; Sugiyama, Hideo

    2004-01-01

    The pH values of wild mushroom substrata, the influence of pH in medium on the appearance frequencies of microorganisms from mushroom substrata, and growth and Cs uptake by several microorganisms were investigated. The results showed that the pH values of 42 mushroom substrata were slightly acidic. There was no remarkable difference in the appearance frequencies of filamentous actinomycetes and planktonic bacteria at pH 5, 6 and 7, except in the samples of mushroom substrata from Mt. Fuji. The values of Cs concentration ratio (CR) for microorganisms isolated from mushroom substrata and for mushrooms were almost the same level, suggesting that those microorganisms could take up Cs in substrata and reserve Cs in their cells. (author)

  10. Cs[FeSe{sub 2}], Cs{sub 3}[FeSe{sub 2}]{sub 2}, and Cs{sub 7}[Fe{sub 4}Se{sub 8}]. Missing links of known chalcogenido ferrate series

    Energy Technology Data Exchange (ETDEWEB)

    Stueble, Pirmin; Roehr, Caroline [Institut fuer Anorganische und Analytische Chemie, Universitaet Freiburg (Germany)

    2017-11-17

    The three cesium selenido ferrate title compounds with an Se:Fe ratio of 2:1 were synthesized from stoichiometric samples reacting elemental Cs either (A) with Fe and Se in a double-crucible setup (Cs[FeSe{sub 2}], Cs{sub 3}[FeSe{sub 2}]{sub 2}) or (B) with previously prepared FeSe{sub 2} (Cs{sub 3}[FeSe{sub 2}]{sub 2}, Cs{sub 7}[Fe{sub 4}S{sub 8}]) (T{sub max} = 800-1000 C). The pure Fe{sup III} ferrate Cs[FeSe{sub 2}] crystallizes in the Tl[FeSe{sub 2}] type [monoclinic, space group C2/m, a = 1392.95(10), b = 564.43(3), c = 737.44(6) pm, β = 119.163(5) , Z = 4, R{sub 1} = 0.0550]. It is thus not isotypic to all other alkali ferrates(III) A[FeS{sub 2}] and A[FeSe{sub 2}] containing chains of edge-sharing tetrahedra, but crystallizes in a t2 subgroup of the Immm structure of Cs[FeS{sub 2}]. The mixed-valent chain compound Cs{sub 3}[FeSe{sub 2}]{sub 2} is isotypic to its sulfido analogue [orthorhombic, space group Pnma, a = 777.88(6), b = 1151.02(6), c = 1341.61(7) pm, Z = 4, R{sub 1} = 0.0470]. In contrast to the isopunctal Na{sub 3}[FeSe{sub 2}]{sub 2} type K/Rb compounds the chains are only slightly corrugated. The monoclinic, likewise mixed-valent Fe{sup II/III} selenido ferrate Cs{sub 7}[Fe{sub 4}Se{sub 8}] [monoclinic, space group C2/c, a = 1953.79(10), b = 879.71(5), c = 1717.03(10) pm, β = 117.890(2) , Z = 4, R{sub 1} = 0.0816] is isostructural both to the cesium sulfido and tellurido compound. The structure contains oligomeric moieties of four edge sharing [FeSe{sub 4}] tetrahedra forming slightly distorted tetrahedral clusters [Fe{sub 4}Se{sub 8}]{sup 7-}, which are surrounded by a cube of 26 Cs cations. Based on a structure map, the crystal chemistry of the three title compounds is discussed together with all chain/cluster ferrates of the general series A{sub 1+x}[Fe{sup III}{sub 1-x}Fe{sup II}{sub x}Q{sub 2}] (x = 0-1; A = Na, K, Rb, Cs; Q = S, Se, Te). (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Learning Flash CS4 Professional

    CERN Document Server

    Shupe, Rich

    2009-01-01

    Learning Flash CS4 Professional offers beginners and intermediate Flash developers a unique introduction to the latest version of Adobe's powerful multimedia application. This easy-to-read book is loaded with full-color examples and hands-on tasks to help you master Flash CS4's new motion editor, integrated 3D system, and character control using the new inverse kinematics bones animation system. No previous Flash experience is necessary.

  12. The Two Translationally Controlled Tumor Protein Genes, CsTCTP1 and CsTCTP2, Are Negative Modulators in the Cucumis sativus Defense Response to Sphaerotheca fuliginea

    Directory of Open Access Journals (Sweden)

    Xiangnan Meng

    2018-04-01

    Full Text Available Pathogen stress often significantly decreases cucumber production. However, knowledge regarding the molecular mechanism and signals of cucumber disease resistance is far from complete. Here, we report two translationally controlled tumor protein genes, CsTCTP1 and CsTCTP2, that are both negative modulators in the Cucumis sativus defense response to Sphaerotheca fuliginea. Subcellular localization analysis showed that CsTCTP1 and CsTCTP2 were both localized in the cytoplasm. Expression analysis indicated that the transcript levels of CsTCTP1 and CsTCTP2 were linked to the degree of cucumber resistance to S. fuliginea. Transient overexpression of either CsTCTP1 or CsTCTP2 in cucumber cotyledons impaired resistance to S. fuliginea, whereas silencing of either CsTCTP1 or CsTCTP2 enhanced cucumber resistance to S. fuliginea. The relationship of several defense-related genes and ABA and target of rapamycin (TOR signaling pathway-related genes to the overexpressing and silencing of CsTCTP1/CsTCTP2 in non-infested cucumber plants was investigated. The results indicated that CsTCTP1 participates in the defense response to S. fuliginea by regulating the expression of certain defense-associated genes and/or ABA signaling pathway-associated genes, and CsTCTP2 participates through regulating the expression of TOR signaling pathway-associated genes. Our findings will guide enhancing the resistance of cucumber to powdery mildew.

  13. Coprecipitation of 137Cs and 85Sr microquantities with complex compound [M(18-crown-6)]BPH4 (M=Na+, Cs+) from neutral and alkaline solutions

    International Nuclear Information System (INIS)

    Konovalova, N.A.; Rumer, I.A.; Kulyukhin, S.A.

    2009-01-01

    The paper reports the possibility of joint separation of 137 Cs and 85 Sr from neutral and alkaline aqueous solutions by their coprecipitation with the solid phase of complex compounds [M(18-crown-6)]BPh 4 (M=Na + , Cs + ), as well as to study the coprecipitation of 137 Cs and 85 Sr with the solid phase CsBPh 4 . It is found that complex compounds [M(18-crown-6)]BPh 4 (M=Na + , Cs + ) increased the degree of 85 Sr separation from solutions virtually two- to threefold vs. CsBPh 4 . Chloride and nitrate were found to have hardly any impact on the coprecipitation of 137 Cs and 85 Sr with [M(18-crown-6)]BPh 4 (M = Na + , Cs + ). (orig.)

  14. Photoluminescence of colloidal CdSe nano-tetrapods and quantum dots in oxygenic and oxygen-free environments

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Lijuan [Donghua University, Applied Physics Department, Shanghai (China); Hong Kong University of Science and Technology, Physics Department and the Institute of Nano-Science and Technology, Hong Kong (China); Pang, Qi; Ge, Weikun; Wang, Jiannong [Hong Kong University of Science and Technology, Physics Department and the Institute of Nano-Science and Technology, Hong Kong (China); Yang, Shihe [Hong Kong University of Science and Technology, Chemistry Department and the Institute of Nano-Science and Technology, Hong Kong (China)

    2011-05-15

    The effects of oxygenic versus oxygen-free environments on colloidal CdSe nano-tetrapods and quantum dots (QDs) were studied using both continuous and time-resolved photoluminescence (PL) measurements. The decays of PL intensities for tetrapods and QDs in oxygen-free solution (chloroform) and in air (on silicon) can be well fitted by a bi-exponential function. Based on the emission-energy dependence of carrier lifetimes and the amplitude ratio of the fast-decay component to the slow-decay component, the fast and slow PL decays of CdSe nanocrystals are attributed to the recombination of delocalized carriers in the core states and localized carriers in the surface states, respectively. The PL intensities of CdSe nano-tetrapods and QDs were found to be five times and an order of magnitude higher in air than in vacuum, respectively, which is explained by the passivation of surface defects by the polar gas (oxygen) absorption. The lower enhancement in PL intensities of CdSe nano-tetrapods is explained by the special morphology of the tetrapods. (orig.)

  15. Quantum interference effects in [Co/Bi]n thin films

    Directory of Open Access Journals (Sweden)

    Athanasopoulos P.

    2014-07-01

    Full Text Available Magnetoconductivity (MC, Δσ(Β, and Hall coefficient, RH(B, measurements have been performed in polycrystalline thin films of Bi(15nm, Bi(10nm/Co(1nm/Bi(10nm trilayer and [Co(0.7nm/Bi(2nm]10 multilayer, grown by magnetron scattering. The temperature dependence of RH(B curves reveal the existence of a second conduction channel below 250K, that can be assigned to surface states. MC measurements between ±0.4T show at 5K an interplay between weak-antilocalization (WAL in Bi and Bi/Co/Bi films and weal-localization (WL in [Co/Bi]10 multilayer.

  16. Attempting to realize n-type BiCuSeO

    Science.gov (United States)

    Zhang, Xiaoxuan; Feng, Dan; He, Jiaqing; Zhao, Li-Dong

    2018-02-01

    As an intrinsic p-type semiconductor, BiCuSeO has been widely researched in the thermoelectric community, however, n-type BiCuSeO has not been reported so far. In this work, we successfully realized n-type BiCuSeO through carrying out several successive efforts. Seebeck coefficient of BiCuSeO was increased through introducing extra Bi/Cu to fill the Bi/Cu vacancies that may produce holes, and the maximum Seebeck coefficient was increase from +447 μVK-1 for undoped BiCuSeO to +638 μVK-1 for Bi1.04Cu1.05SeO. The Seebeck coefficient of Bi1.04Cu1.05SeO was changed from p-type to n-type through electron doping through introducing Br/I in Se sites, the maximum negative Seebeck coefficient can reach ∼ -465 μVK-1 and -543 μVK-1 for Bi1.04Cu1.05Se1-xIxO and Bi1.04Cu1.05Se1-xBrxO, respectively. Then, after compositing Bi1.04Cu1.05Se0.99Br0.01O with Ag, n-type BiCuSeO can be absolutely obtained in the whole temperature range of 300-873 K, the maximum ZT 0.05 was achieved at 475 K in the Bi1.04Cu1.05Se0.99Br0.01O+15% Ag. Our report indicates that it is possible to realize n-type conducting behaviors in BiCuSeO system.

  17. Growth and characterization of indium-doped Cd1−xZnxTe crystal by traveling heater method

    International Nuclear Information System (INIS)

    Wei, Gaoli; Wang, Linjun; Zhang, Jijun; Yuan, Zhenwen; Qin, Kaifeng; Min, Jiahua; Liang, Xiaoyan; Xia, Yiben

    2013-01-01

    An indium-doped detector grade Cd 0.9 Zn 0.1 Te crystal was grown by the THM technique from Te-rich solution. The as-grown crystal showed the dark resistivity of (1–3)×10 10 Ω cm. Through IR transmission microscopy Te inclusion with regular triangular or circular shapes could be observed, and the size of Te inclusion was around 7 μm and the concentration was ∼10 5 cm −3 . The impurity concentrations were greatly reduced for the THM grown CZT, as compared to the Bridgman method grown CZT. A resolution of 8.5% was achieved under the 662 keV 137 Cs gamma ray radiation at room temperature for the as-grown CZT samples. -- Highlights: ► Detector grade Cd 1−x Zn x Te has been successfully grown by the THM technique. ► The as-grown CZT has a resistivity of ∼10 10 Ω cm. ► Te inclusions' size and concentration were comparable to the commercial CZT. ► A resolution of 8.5% was achieved for the 137 Cs 662 keVgamma line

  18. Mobility and plant availability of radioactive Cs in natural soil in relation to stable Cs, other alkali elements and soil fertility

    International Nuclear Information System (INIS)

    Varskog, P.; Steinnes, E.; Naeumann, R.

    1994-01-01

    The mobility and plant availability of radioactive Cs from the Chernobyl accident in natural soil-plant systems of varying fertility were studied at three sampling locations situated in subalpine areas of central Norway. The soil samples included litter, humus (0-2 cm and 2-5 cm depth), and mineral soil (8-12 cm and 20-30 cm depth), and the plant species studied were Betula nana, Empetrum hermaphroditum and Juncus trifidus. The lichen Cetraria nivalis was also sampled. The sampling took place in the middle of the growth season during the period 1987-1989. The soil and vegetation samples were analysed with respect to total radiocaesium ( 137 Cs and 134 Cs), Rb, stable Cs and exchangeable 137 Cs (in soil only), K, Ca and Mg. (Author)

  19. Effect of nutrition peculiarities on 137Cs uptake

    International Nuclear Information System (INIS)

    Knizhnikov, V.A.; Marej, A.N.; Borisov, B.K.; Petukhova, Eh.V.

    1980-01-01

    Reasons for different 137 Cs uptake from diets of the vegetable-animal type are studied. Indexes of accumulation multiplicity for Moscow and the Byelorussian-Ukrainian wooded district are compared. 137 Cs buildup levels in the organism of the USSR and the USA population are presented. The most probable reason for peculiarities in 137 Cs uptake from various types of diet, as well as the reason for the alterations in the uptake of this radionuclide from the diet of the same type, is the non-uniformity of 137 Cs contribution of aerial and nonaerial origin

  20. Photon mass attenuation coefficients of a silicon resin loaded with WO3, PbO, and Bi2O3 Micro and Nano-particles for radiation shielding

    Science.gov (United States)

    Verdipoor, Khatibeh; Alemi, Abdolali; Mesbahi, Asghar

    2018-06-01

    Novel shielding materials for photons based on silicon resin and WO3, PbO, and Bi2O3 Micro and Nano-particles were designed and their mass attenuation coefficients were calculated using Monte Carlo (MC) method. Using lattice cards in MCNPX code, micro and nanoparticles with sizes of 100 nm and 1 μm was designed inside a silicon resin matrix. Narrow beam geometry was simulated to calculate the attenuation coefficients of samples against mono-energetic beams of Co60 (1.17 and 1.33 MeV), Cs137 (663.8 KeV), and Ba133 (355.9 KeV). The shielding samples made of nanoparticles had higher mass attenuation coefficients, up to 17% relative to those made of microparticles. The superiority of nano-shields relative to micro-shields was dependent on the filler concentration and the energy of photons. PbO, and Bi2O3 nanoparticles showed higher attenuation compared to WO3 nanoparticles in studied energies. Fabrication of novel shielding materials using PbO, and Bi2O3 nanoparticles is recommended for application in radiation protection against photon beams.

  1. Bi[NC5H3(CO2)2](OH2)xF (x=1 and 2): New one-dimensional Bi-coordination materials—Reversible hydration and topotactic decomposition to α-Bi2O3

    International Nuclear Information System (INIS)

    Jeon, Hye Rim; Lee, Dong Woo; Ok, Kang Min

    2012-01-01

    Two one-dimensional bismuth-coordination materials, Bi[NC 5 H 3 (CO 2 ) 2 ](OH 2 ) x F (x=1 and 2), have been synthesized by hydrothermal reactions using Bi 2 O 3 , 2,6-NC 5 H 3 (CO 2 H) 2 , HF, and water at 180 °C. Structures of the two materials were determined by single-crystal X-ray diffraction. Although they have different crystal structures, both Bi-organic materials shared a common structural motif, a one-dimensional chain structure consisting of Bi 3+ cations and pyridine dicarboxylate linkers. Detailed structural analyses include infrared spectroscopy, thermogravimetric analysis, and reversible hydration reactions for the coordinated water molecules were reported. Also, thermal decomposition of the rod-shaped Bi[NC 5 H 3 (CO 2 ) 2 ](OH 2 )F single crystals at 800 °C led to α-Bi 2 O 3 that maintained the same morphology of the original crystals. - Graphical abstract: Calcination of the Bi[NC 5 H 3 (CO 2 ) 2 ](OH 2 )F single crystals at 800 °C results in the α-Bi 2 O 3 rods that maintain the original morphology of the crystals. Highlights: ► Synthesis of one-dimensional chain Bi-organic frameworks. ► Reversible hydration reactions of Bi[NC 5 H 3 (CO 2 ) 2 ](OH 2 )F. ► Topotactic decomposition maintaining the same morphology of the original crystals.

  2. Thermochemical data acquisition - Reactor safety programme 1988-1991

    International Nuclear Information System (INIS)

    Ball, R.G.J.; Rand, M.H.; Cordfunke, E.H.P.; Konings, R.J.M.

    1991-10-01

    Thermochemical data are required for specific fission product and reactor materials compounds in order to quantify the consequences of a severe accident within a light water reactor. Approximately 40 important compounds/systems have been identified for study for which thermodynamic data did not exist or were inadequate. Work is described on the analysis of approximately half of these systems. Experimental studies have been undertaken to determine the thermodynamic quantities of the following compounds : Cs 2 MoO 4 , CsBO 2 , Cs 2 RuO 4 , Cs 2 RuO 4 , Cs 2 Mno 4 , Cs 2 CrO 4 , Cs 2 TeO 3 ,Cs 2 Te, InI, InI 3 , In 2 I 6 , In 2 Te, Cd(OH) 2 , Cd(OH) 2 , TeO(OH) 2 ,CdI 2 , Cd 2 I 4 , Cs 2 CdI 4 , CsCdI 3 , Cs 2 CdI 4 , Cs 3 PO 4 and Cd-In-Ag. Critical assessments have been made on the following systems : In-I, In-Te, Cd-I, Sr-B-O and Ba-B-O. The thermodynamic quantities of these compounds have been calculated over the temperature range from 298 to 3000 K. The adoption of these data within appropriate modelling codes will allow the fission product species and transport to be predicted with greater confidence, thus providing more accurate assessments of the consequences of severe reactor accidents

  3. Controlled hydrothermal synthesis of BiOxCly/BiOmIn composites exhibiting visible-light photocatalytic degradation of crystal violet

    International Nuclear Information System (INIS)

    Jiang, Yu-Rou; Lin, Ho-Pan; Chung, Wen-Hsin; Dai, Yong-Ming; Lin, Wan-Yu; Chen, Chiing-Chang

    2015-01-01

    Highlights: • This is the first report on a series of BiO x Cl y /BiO m I n heterojunctions. • The BiO x Cl y /BiO m I n composition was controlled by adjusting the growth parameters. • The BiO x Cl y /BiO m I n were indirect semiconductors with a 1.78–2.95-eV bandgap. • The new photocatalysts removed CV at a much faster rate than TiO 2 . • Mechanisms were determined by separating the intermediates using HPLC-MS. - Abstract: A series of BiO x Cl y /BiO m I n composites were prepared using autoclave hydrothermal methods. The composition and morphologies of the BiO x Cl y /BiO m I n composites were controlled by adjusting the experimental conditions: the reaction pH value, temperature, and KCl/KI molar ratio. The products were characterized using X-ray diffraction, scanning electron microscopy-electron dispersive X-ray spectroscopy, UV–vis diffuse reflectance spectroscopy, Brunauer–Emmett–Teller specific surface areas, cathodoluminescence, high-resolution transmission electron microscopy, and high-resolution X-ray photoelectron spectroscopy. The photocatalytic efficiencies of composite powder suspensions were evaluated by monitoring the crystal violet (CV) concentrations. In addition, the quenching effects of various scavengers indicated that the reactive O 2 · − played a major role, and OH· or h + played a minor role in CV degradation. The intermediates formed during the decomposition process were isolated, identified, and characterized using high performance liquid chromatography-photodiode array-electrospray ionization-mass spectrometry to elucidate the CV decomposition mechanism

  4. Effect of Silver Doping on Transport Properties of Bi2Se3: AgxBi2Se3 and Bi2-xAgxSe3

    Science.gov (United States)

    Zhang, Min; Wei, Zhan-Tao

    2018-03-01

    Ag-doped Bi2Se3 with the formula AgxBi2Se3 and Bi2-xAgxSe3 were prepared and their electrical and magnetic transport properties have been investigated to study the influence of silver doping on transport properties of Bi2Se3 with different Ag-doped method. All samples exhibited metallic resistivity and the resistivity increased with increasing Ag concentration. The lattice parameter c of Ag-substituted and Ag-intercalated samples displays a contrary change as the Ag concentration increased. For the Ag-intercalated samples, both the resistance upturn were observed in the curves of temperature dependent of resistivity and temperature dependent of magnetoresistance, respectively, indicating that the enhanced surface effect was obtained in those samples. Monotonously, field-induced MR peaks around 200 K were also observed in those samples. Similar behaviors were not observed in the Ag-substituted samples.

  5. Effect of Silver Doping on Transport Properties of Bi2Se3: AgxBi2Se3 and Bi2-xAgxSe3

    Science.gov (United States)

    Zhang, Min; Wei, Zhan-Tao

    2018-05-01

    Ag-doped Bi2Se3 with the formula AgxBi2Se3 and Bi2-xAgxSe3 were prepared and their electrical and magnetic transport properties have been investigated to study the influence of silver doping on transport properties of Bi2Se3 with different Ag-doped method. All samples exhibited metallic resistivity and the resistivity increased with increasing Ag concentration. The lattice parameter c of Ag-substituted and Ag-intercalated samples displays a contrary change as the Ag concentration increased. For the Ag-intercalated samples, both the resistance upturn were observed in the curves of temperature dependent of resistivity and temperature dependent of magnetoresistance, respectively, indicating that the enhanced surface effect was obtained in those samples. Monotonously, field-induced MR peaks around 200 K were also observed in those samples. Similar behaviors were not observed in the Ag-substituted samples.

  6. CsMYB5a and CsMYB5e from Camellia sinensis differentially regulate anthocyanin and proanthocyanidin biosynthesis.

    Science.gov (United States)

    Jiang, Xiaolan; Huang, Keyi; Zheng, Guangshun; Hou, Hua; Wang, Peiqiang; Jiang, Han; Zhao, Xuecheng; Li, Mingzhuo; Zhang, Shuxiang; Liu, Yajun; Gao, Liping; Zhao, Lei; Xia, Tao

    2018-05-01

    Tea is one of the most widely consumed nonalcoholic beverages worldwide. Polyphenols are nutritional compounds present in the leaves of tea plants. Although numerous genes are functionally characterized to encode enzymes that catalyze the formation of diverse polyphenolic metabolites, transcriptional regulation of those different pathways such as late steps of the proanthcoyanidin (PA) pathway remains unclear. In this study, using different tea transcriptome databases, we screened at least 140 R2R3-MYB transcription factors (TFs) and grouped them according to the basic function domains of the R2R3 MYB TF superfamily. Among 140 R2R3 TFs, CsMYB5a and CsMYB5e were chosen for analysis because they may be involved in PA biosynthesis regulation. CsMYB5a-overexpressing tobacco plants exhibited downregulated anthocyanin accumulation but a high polymeric PA content in the flowers. Overexpression of CsMYB5e in tobacco plants did not change the anthocyanin content but increased the dimethylaminocinnamaldehyde-stained PA content. RNA-seq and qRT-PCR analyses revealed that genes related to PA and anthocyanin biosynthesis pathways were markedly upregulated in both CsMYB5a- and CsMYB5e-overexpressing flowers. Three UGTs and four GSTs were identified as involved in PA and anthocyanin glycosylation and transportation in transgenic plants. These results provide new insights into the regulation of PA and anthocyanin biosynthesis in Camellia sinensis. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Reduction in thermal conductivity of BiSbTe lump

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Kaleem [King Saud University, Sustainable Energy Technologies Center, College of Engineering, PO Box 800, Riyadh (Saudi Arabia); Wan, C. [Tsinghua University, State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Beijing (China); Al-Eshaikh, M.A.; Kadachi, A.N. [King Saud University, Research Center, College of Engineering, PO Box 800, Riyadh (Saudi Arabia)

    2017-03-15

    In this work, systematic investigations on the thermal conductivities of BiSbTe lump, microstructured pristine BiSbTe bulk and single wall carbon nanotubes (SWCNTs)/BiSbTe bulk nanocomposites were performed. BiSbTe lumps were crushed to form a coarse powder (200 μm) and effect of particle size reduction on the effective thermal conductivity of BiSbTe (200 μm) bulk were analyzed. For further reduction in the conductivity, a two pronged strategy has been employed. First, additional refinement of BiSbTe (200 μm) were performed through ball milling in an inert environment. Second, SWCNTs in 0.75, and 1.0 vol% were distributed uniformly in the fine BiSbTe ball milled powder. The results showed that the effective thermal conductivities decrease with the reduction in the particle size from lump to BiSbTe (200 μm) bulk as well as with the addition of SWCNTs accompanied by further refinement of BiSbTe particles. The significant reduction in thermal conductivities of the lump was achieved for pure BiSbTe (200 μm) bulk and 0.75 vol% of SWCNTs/BiSbTe composite. This can be ascribed to the enhanced phonon scattering by the grain boundaries between the nanostructured BiSbTe particles as well as the interfaces between BiSbTe and the low dimensional carbon nanotubes. (orig.)

  8. Recovery of Cs from high level radioactive waste

    International Nuclear Information System (INIS)

    Kumar, Amar; Kaushik, C.P.; Raj, K.; Varshney, Lalit

    2008-01-01

    Separation of Cs + from HLW restricts the personal radiation exposure during the vitrification and prevents thermal deformation of conditioned waste matrix during storage because of the high calorific power of 134 Cs (13.18 W/g) and 137 Cs (0.417 W/g) which would markedly reduce the storage cost. Separation will also reduce its volatility during vitrification and extent of migration from the vitrified mass in repository. In addition 137 Cs has enormous applications as radiation sources in food preservation, sterilization of medical products, brachy therapy, blood irradiation, hygienization of sewage sludge etc. The use of 137 Cs (T 1/2 = 30 years) in place of 60 Co (T 1/2 = 5.2 years) will also reduce the shielding requirement and frequency of source replenishment which will ease the handling/transportation of radioactive source

  9. Bacterial CS2 Hydrolases from Acidithiobacillus thiooxidans Strains Are Homologous to the Archaeal Catenane CS2 Hydrolase

    NARCIS (Netherlands)

    Smeulders, M.J.; Pol, A. van der; Venselaar, H.; Barends, T.R.; Hermans, J.; Jetten, M.S.M.; Camp, H.J.M. op den

    2013-01-01

    Carbon disulfide (CS2) and carbonyl sulfide (COS) are important in the global sulfur cycle, and CS2 is used as a solvent in the viscose industry. These compounds can be converted by sulfur-oxidizing bacteria, such as Acidithiobacillus thiooxidans species, to carbon dioxide (CO2) and hydrogen sulfide

  10. Korelasi Kadar Feritin dengan Jumlah CD4, CD8, dan Rasio CD4/CD8 pada Penyandang Talasemia Mayor Anak

    Directory of Open Access Journals (Sweden)

    Bonnie Arseno

    2017-11-01

    Hasil. Didapatkan jumlah CD4 absolut, CD4%, CD8 absolut dan rasio CD4/CD8 menurun. Selain itu, terdapat jumlah CD4 absolut, CD8 absolut dan CD8% meningkat. Pada kelompok usia ≤5 tahun, korelasi kadar feritin dengan CD8 absolut, CD8%, dan rasio CD4/CD8 berturut-turut menghasilkan koefisien korelasi 0,691, 0,557, -0,680, dan p<0,05. Sementara pada kelompok lama terapi ≤5 tahun korelasi kadar feritin dengan CD8 absolut, CD8%, dan rasio CD4/CD8 menghasilkan koefisien korelasi 0,709, 0,571, -0,726 dengan p<0,05. Kesimpulan. Tidak terdapat korelasi antara kadar feritin dengan jumlah CD4, CD8, rasio CD4/CD8. Peningkatan kadar feritin akan diikuti dengan peningkatan jumlah CD8 absolut dan CD8%, serta penurunan rasio CD4/CD8 pada penyandang talasemia mayor anak berdasar atas usia dan lama terapi ≤5 tahun.

  11. The effect of oxidant on resputtering of Bi from Bi-Sr-Ca-Cu-O films

    Science.gov (United States)

    Grace, J. M.; McDonald, D. B.; Reiten, M. T.; Olson, J.; Kampwirth, R. T.; Gray, K. E.

    1991-09-01

    The type and partial pressure of oxidant mixed with argon can affect the selective resputtering of Bi in composite-target, magnetron-sputtered Bi-Sr-Ca-Cu-O films. Comparative studies using oxygen and ozone show that ozone is a more potent oxidant, as well as a more potent source of resputterers, than is oxygen. Severe resputtering from ozone is significantly reduced by a -40 V potential on the sample block. We suggest that oxygen causes resputtering by forming O2(+)p , which interacts with the target to produce energetic O(-). In contrast, ozone may form lower-energy O(-) by electron impact in the dark space. Negative oxygen ions from the target itself may be responsible for a background resputtering effect. Our results and those found for Y-Ba-Cu-O by others are comparable. Bi in Bi-Sr-Ca-Cu-O behaves as Ba in Y-Ba-Cu-O, with regard to selective resputtering; furthermore, the response of Sr, Ca, and Cu to oxygen in sputtered Bi-Sr-Ca-Cu-O is similar to what is observed for Cu in Y-Ba-Cu-O.

  12. Preparation and Faraday rotation of Bi-YIG/PMMA nanocomposite

    Science.gov (United States)

    Fu, H. P.; Hong, R. Y.; Wu, Y. J.; Di, G. Q.; Xu, B.; Zheng, Y.; Wei, D. G.

    Bismuth-substituted yttrium iron garnet (Bi-YIG) nanoparticles (NPs) were prepared by coprecipitation and subsequent heating treatment. Thermal gravity-differential thermal analysis was performed to investigate the thermal behavior of the Bi-YIG precursors and to decide the best annealing temperature. Phase formation of garnet NPs was investigated by X-ray powder diffraction. The size of Bi-YIG NPs was investigated by transmission electron microscopy, and the magnetic properties of Bi-YIG NPs were measured using a vibrating sample magnetometer. The results show that the temperature needed for the transformation of Bi-YIG from the amorphous phase to the garnet phase decreases with increasing Bi content, and Bi-YIG NPs with sizes of 28-78 nm are obtained after heating treatment at 650-1000 °C. The saturation magnetization of Bi-YIG NPs increases as the Bi content increases. Moreover, the Faraday rotation of polymethyl methacrylate (PMMA) slices doped with Bi-YIG NPs was investigated. The results indicate that the angle of Faraday rotation increases with increasing Bi content in PMMA composites, and the maximum value of the figure of merit is 1.46°, which is comparable to the value of a sputtered film. The Bi-YIG NPs-doped PMMA slices are new promising materials for magneto-optical devices.

  13. Facile synthesis of AgI/BiOI-Bi{sub 2}O{sub 3} multi-heterojunctions with high visible light activity for Cr(VI) reduction

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qi [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018 (China); The Brook Byer Institute for Sustainable Systems and School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta 30332 (United States); Shi, Xiaodong; Liu, Enqin [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018 (China); Crittenden, John C. [The Brook Byer Institute for Sustainable Systems and School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta 30332 (United States); Ma, Xiangjuan; Zhang, Yi [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018 (China); Cong, Yanqing, E-mail: yqcong@hotmail.com [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018 (China)

    2016-11-05

    Graphical abstract: Highly visible-light-active AgI/BiOI-Bi{sub 2}O{sub 3} with multi-heterojunctions was developed. - Highlights: • Visible-light-active AgI/BiOI-Bi{sub 2}O{sub 3} with multi-heterojunctions was prepared. • Highly enhanced photocatalytic reduction of Cr(VI) was observed. • k{sub Cr(VI)} on AgI/BiOI-Bi{sub 2}O{sub 3} increased by ca.16 times relative to Bi{sub 2}O{sub 3}. • Decreased E{sub g}, shifted E{sub fb} and reduced charge transfer resistance were observed. • Simultaneous reduction of Cr(VI) and degradation of organics were achieved. - Abstract: AgI sensitized BiOI-Bi{sub 2}O{sub 3} composite (AgI/BiOI-Bi{sub 2}O{sub 3}) with multi-heterojunctions was prepared using simple etching-deposition process. Different characterization techniques were performed to investigate the structural, optical and electrical properties of the as-prepared photocatalysts. It was found that the ternary AgI/BiOI-Bi{sub 2}O{sub 3} composite exhibited: (1) improved photocurrent response, (2) smaller band gap, (3) greatly reduced charge transfer resistance and (4) negative shift of flat band potential, which finally led to easier generation and more efficient separation of photo-generated electron-hole pairs at the hetero-interfaces. Thus, for the reduction of Cr(VI), AgI/BiOI-Bi{sub 2}O{sub 3} exhibited excellent photocatalytic activity under visible light irradiation at near neutral pH. AgI/BiOI-Bi{sub 2}O{sub 3} was optimized when the initial molar ratio of KI to Bi{sub 2}O{sub 3} and AgNO{sub 3} to Bi{sub 2}O{sub 3} was 1:1 and 10%, respectively. The estimated k{sub Cr(VI)} on optimized AgI/BiOI-Bi{sub 2}O{sub 3} was about 16 times that on pure Bi{sub 2}O{sub 3}. Good stability was also observed in cyclic runs, indicating that the current multi-heterostructured photocatalyst is highly desirable for the remediation of Cr(VI)-containing wastewater.

  14. In situ grown hierarchical 50%BiOCl/BiOI hollow flowerlike microspheres on reduced graphene oxide nanosheets for enhanced visible-light photocatalytic degradation of rhodamine B

    Science.gov (United States)

    Su, Xiangde; Yang, Jinjin; Yu, Xiang; Zhu, Yi; Zhang, Yuanming

    2018-03-01

    50%BiOCl/BiOI/reduced graphene oxide (50%BiOCl/BiOI/rGO) composite photocatalyst was synthesized successfully by a facile one-step solvothermal route in this work. Reduction of graphene oxide (GO) took place in the process of solvothermal reaction and a new Bi-C bond between rGO and 50%BiOCl/BiOI was formed. The introduction of rGO affected the morphology of 50%BiOCl/BiOI, resulting in the transformation of 50%BiOCl/BiOI from solid microspheres to hollow microspheres. Both the introduction of rGO and formation of 50%BiOCl/BiOI hollow microspheres can facilitate the light absorption. The strong interaction between 50%BiOCl/BiOI and rGO and the electrical conductivity of rGO greatly improved the effective separation of photogenerated carriers. Hence, GOB-5 demonstrated the highest photocatalytic activity which was over twice of the pristine 50%BiOCl/BiOI in the presence of visible light. Mechanism study revealed that 50%BiOCl/BiOI generated electrons and holes in the presence of visible light, and holes together with rad O2- generated from reduction of O2 by electrons degraded the pollutant directly. Overall, this work provides an excellent reference to the synthesis of chemically bonded BiOX/BiOY (X, Y = Cl, Br, I)/rGO nanocomposite and helps to promote their applications in environmental protection and photoelectric conversion.

  15. Early stages of Cs adsorption mechanism for GaAs nanowire surface

    Science.gov (United States)

    Diao, Yu; Liu, Lei; Xia, Sihao; Feng, Shu

    2018-03-01

    In this study, the adsorption mechanism of Cs adatoms on the (100) surface of GaAs nanowire with [0001] growth direction is investigated utilizing first principles method based on density function theory. The adsorption energy, work function, atomic structure and electronic property of clean surface and Cs-covered surfaces with different coverage are discussed. Results show that when only one Cs is adsorbed on the surface, the most favorable adsorption site is BGa-As. With increasing Cs coverage, work function gradually decreases and gets its minimum at 0.75 ML, then rises slightly when Cs coverage comes to 1 ML, indicating the existence of 'Cs-kill' phenomenon. According to further analysis, Cs activation process can effectively reduce the work function due to the formation of a downward band bending region and surface dipole moment directing from Cs adatom to the surface. As Cs coverage increases, the conduction band minimum and valence band maximum both shift towards lower energy side, contributed by the orbital hybridization between Cs-5s, Cs-5p states and Ga-4p, As-4s, As-4p states near Fermi level. The theoretical calculations and analysis in this study can improve the Cs activation technology for negative electron affinity optoelectronic devices based on GaAs nanowires, and also provide a reference for the further Cs/O or Cs/NF3 activation process.

  16. alpha-decay spectroscopy of light odd-odd Bi isotopes - II sup 1 sup 8 sup 6 Bi and the new nuclide sup 1 sup 8 sup 4 Bi

    CERN Document Server

    Andreyev, A N; Ackermann, D; Münzenberg, G; Hessberger, F P; Hofmann, S; Kojouharov, I; Kindler, B; Lommel, B; Huyse, M; Vel, K V D; Duppen, P V; Heyde, Kris L G

    2003-01-01

    Alpha-decay of the new nuclide sup 1 sup 8 sup 4 Bi has been studied in the complete-fusion reaction sup 9 sup 3 Nb( sup 9 sup 4 Mo, 3n) sup 1 sup 8 sup 4 Bi at the velocity filter SHIP. The evaporation residues were separated in-flight and subsequently identified on the basis of recoil-alpha, recoil-alpha-gamma analysis and excitation functions measurements. Two alpha-decaying isomeric states in sup 1 sup 8 sup 4 Bi with half-life values of 13(2) ms and 6.6(1.5) ms were identified. The alpha-branching ratio of sup 1 sup 8 sup 0 Tl was deduced for the first time as b subalpha = (2-12)%. Improved data on the fine-structure alpha-decay of sup 1 sup 8 sup 6 Bi were obtained in the sup 9 sup 3 Nb( sup 9 sup 5 Mo, 2n) sup 1 sup 8 sup 6 Bi reaction. A similarity of the decay energies and half-life values of sup 1 sup 8 sup 4 sup , sup 1 sup 8 sup 6 Bi is pointed out and a possible explanation for this effect is suggested.

  17. Application of the Monte Carlo method for the efficiency calibration of CsI and NaI detectors for gamma-ray measurements from terrestrial samples

    International Nuclear Information System (INIS)

    Baccouche, S.; Al-Azmi, D.; Karunakara, N.; Trabelsi, A.

    2012-01-01

    Gamma-ray measurements in terrestrial/environmental samples require the use of high efficient detectors because of the low level of the radionuclide activity concentrations in the samples; thus scintillators are suitable for this purpose. Two scintillation detectors were studied in this work; CsI(Tl) and NaI(Tl) with identical size for measurement of terrestrial samples for performance study. This work describes a Monte Carlo method for making the full-energy efficiency calibration curves for both detectors using gamma-ray energies associated with the decay of naturally occurring radionuclides 137 Cs (661 keV), 40 K (1460 keV), 238 U ( 214 Bi, 1764 keV) and 232 Th ( 208 Tl, 2614 keV), which are found in terrestrial samples. The magnitude of the coincidence summing effect occurring for the 2614 keV emission of 208 Tl is assessed by simulation. The method provides an efficient tool to make the full-energy efficiency calibration curve for scintillation detectors for any samples geometry and volume in order to determine accurate activity concentrations in terrestrial samples. - Highlights: ► CsI (Tl) and NaI (Tl) detectors were studied for the measurement of terrestrial samples. ► Monte Carlo method was used for efficiency calibration using natural gamma emitting terrestrial radionuclides. ► The coincidence summing effect occurring for the 2614 keV emission of 208 Tl is assessed by simulation.

  18. Radioecological studies of 137Cs in limnological ecosystems. 137Cs concentrations in water, sediment and fishes at the pond in Saitama prefecture, Japan

    International Nuclear Information System (INIS)

    Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki; Izumo, Yoshiro

    1998-01-01

    The concentrations of 137 Cs in water, sediment and fishes at the pond in Saitama prefecture were determined in order to elucidate the radioecology of 137 Cs in limnological ecosystems. 137 Cs concentration in water was 0.31±0.002 mBq/l (mean±standard error), and so indicated about 3 times higher than that (0.10 mBq/l) for the river in our previous report. 137 Cs concentrations in sediment, carp, Cyprinus carpio, crucian carp, Carassius auratus cuvieri, and Hakuren, Hypophthalmichthys molitrix, were about 20000, 1200, 2400 and 3100 times higher than that of the water, respectively. These concentrations were higher than those of each sample for the river in our previous report. It was so suggested that 137 Cs tended to be accumulated in these samples at the pond more than the nuclide in the river. Moreover, concentration ratios, concentration of 137 Cs in sediment, crucian carp and Hakuren to that of the water, were about 30, 2 and 3 times higher than these of 40 K, respectively, except for carp of which 137 Cs and 40 K concentration ratios were almost same. These results showed difference in accumulation mechanism between 137 Cs and 40 K in these samples, as well as 137 Cs transfer mechanism in the limnological ecosystems in part. (author)

  19. Long-term behaviours of 137Cs in simulated crop fields

    International Nuclear Information System (INIS)

    Lim, K. M.; Choi, Y. H.; Park, H. K.; Park, D. W.; Lee, W. Y.

    1999-01-01

    In order to understand the long-term behaviour of 137 Cs in crop fields, root uptake and underground distribution of 137 Cs were investigated through a greenhouse experiment where 137 Cs was mixed with topsoil in culture boxes and rice, soybean and Chinese cabbage were grown for 4 years. Soil-to-plant transfer factors of 137 Cs for hulled rice, rice straw, soybean seed and Chinese cabbage reduced by factors of 3-10 depending on crops, and leaching of 137 Cs from the rice culture box decreased by a factor of about 7, in 3 years. The 137 Cs transfer factor for soybean seed were several times higher than that for hulled rice. The amount of 137 Cs leaching during the growing season of rice was as low as 0.025% of applied activity even in the 1st year. The uniformity of 137 Cs distribution in topsoil tended to improve year by year. The present results may be utilized as basic information for the environmental impact assessment and the counter-measure decision when crop fields are contaminated with 137 Cs

  20. Pre-assessment of dose rates of 134Cs, 137Cs, and 60Co for marine biota from discharge of Haiyang Nuclear Power Plant, China

    International Nuclear Information System (INIS)

    Li, Jingjing; Liu, Senlin; Zhang, Yongxing; Chen, Ling; Yan, Yuan; Cheng, Weiya; Lou, Hailin; Zhang, Yongbao

    2015-01-01

    Haiyang Nuclear Power Plant to be built in China was selected as a case for the dose pre-assessment for marine biota in this study. The concentrations of Cs and Co in organisms (turbot, yellow croaker, swimming crab, abalone, sea cucumber, and sea lettuce), seawater, and bottom sediment sampled on-site were measured by neutron activation analysis, and the site-specific transfer parameters (concentration ratios and distribution coefficients) of Cs and Co were calculated. 134 Cs, 137 Cs, and 60 Co activity concentrations in the organisms and the sediment at the site were calculated with the site-specific transfer parameters and the anticipated activity concentrations in the liquid effluent of the nuclear power plant. The ERICA tool was used to estimate the dose rates of 134 Cs, 137 Cs, and 60 Co to the selected organisms based on the biological models developed. The total dose rates of 134 Cs, 137 Cs, and 60 Co to the six organisms were all <0.001 μGy h −1 . - Highlights: • Pre-assessment for biota dose rates from Haiyang Nuclear Power Plant was made. • The site-specific transfer parameters were obtained by neutron activation analysis. • The dose rates of 134 Cs, 137 Cs, and 60 Co to the organisms were <0.001 μGy h −1

  1. Superstrengthening Bi2Te3 through Nanotwinning

    Science.gov (United States)

    Li, Guodong; Aydemir, Umut; Morozov, Sergey I.; Wood, Max; An, Qi; Zhai, Pengcheng; Zhang, Qingjie; Goddard, William A.; Snyder, G. Jeffrey

    2017-08-01

    Bismuth telluride (Bi2Te3 ) based thermoelectric (TE) materials have been commercialized successfully as solid-state power generators, but their low mechanical strength suggests that these materials may not be reliable for long-term use in TE devices. Here we use density functional theory to show that the ideal shear strength of Bi2Te3 can be significantly enhanced up to 215% by imposing nanoscale twins. We reveal that the origin of the low strength in single crystalline Bi2Te3 is the weak van der Waals interaction between the Te1 coupling two Te 1 - Bi - Te 2 - Bi - Te 1 five-layer quint substructures. However, we demonstrate here a surprising result that forming twin boundaries between the Te1 atoms of adjacent quints greatly strengthens the interaction between them, leading to a tripling of the ideal shear strength in nanotwinned Bi2Te3 (0.6 GPa) compared to that in the single crystalline material (0.19 GPa). This grain boundary engineering strategy opens a new pathway for designing robust Bi2Te3 TE semiconductors for high-performance TE devices.

  2. Comparison of growth texture in round Bi2212 and flat Bi2223 wires and its relation to high critical current density development

    OpenAIRE

    Kametani, F.; Jiang, J.; Matras, M.; Abraimov, D.; Hellstrom, E. E.; Larbalestier, D. C.

    2015-01-01

    Why Bi2Sr2CaCu2Ox (Bi2212) allows high critical current density Jc in round wires rather than only in the anisotropic tape form demanded by all other high temperature superconductors is important for future magnet applications. Here we compare the local texture of state-of-the-art Bi2212 and Bi2223 ((Bi,Pb)2Sr2Ca2Cu3O10), finding that round wire Bi2212 generates a dominant a-axis growth texture that also enforces a local biaxial texture (FWHM

  3. Adsorption and photocatalysis for methyl orange and Cd removal from wastewater using TiO2/sewage sludge-based activated carbon nanocomposites

    Science.gov (United States)

    Rashed, M. Nageeb; Eltaher, M. A.; Abdou, A. N. A.

    2017-12-01

    Nanocomposite TiO2/ASS (TiO2 nanoparticle coated sewage sludge-based activated carbon) was synthesized by the sol-gel method. The changes in surface properties of the TiO2/ASS nanocomposite were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence. The prepared TiO2/ASS nanocomposite was applied for simultaneous removal of methyl orange dye (MO) and Cd2+ from bi-pollutant solution. The factors influencing photocatalysis (TiO2 : ASS ratios, initial pollutant concentrations, solution pH, nanocomposite dosage and UV irradiation time) were investigated. The results revealed that high removal efficiency of methyl orange dye (MO) and Cd2+ from bi-pollutant solution was achieved with TiO2/ASS at a ratio (1 : 2). The obtained results revealed that degradation of MO dye on the TiO2/ASS nanocomposite was facilitated by surface adsorption and photocatalytic processes. The coupled photocatalysis and adsorption shown by TiO2/ASS nanocomposite resulted in faster and higher degradation of MO as compared to MO removal by ASS adsorbent. The removal efficiency of MO by ASS adsorbent and TiO2/ASS (1 : 2) nanocomposite at optimum pH value 7 were 74.14 and 94.28%, respectively, while for Cd2+ it was more than 90%. The experimental results fitted well with the second-order kinetic reaction.

  4. Radioecological studies of {sup 137}Cs in limnological ecosystems. Biochemical states of {sup 137}Cs accumulated in killifish (Medaka, Oryzias latipes) meat

    Energy Technology Data Exchange (ETDEWEB)

    Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki [Saitama Institute of Public Health, Urawa (Japan); Izumo, Yoshiro; Nakamura, Fumio

    1997-07-01

    Biochemical states of {sup 137}Cs accumulated in killifish`s (Medaka, Oryzias latipes) meat were investigated in order to elucidate the accumulation mechanism of the radionuclide in goldfish, Carassius auratus auratus, examined in our preceding report. Most of {sup 137}Cs radioactivity in the killifish`s raw meat accumulated this radionuclide in the radioactive freshwater, were found in the non-protein nitrogenous compound (NPNC) fraction (>92%), also in the killifish`s control raw meat mixed with {sup 137}Cs, the difference between both meat samples was not clear. As the results of gel filtration profiles on Sephadex G-25 for the NPNC fraction of these meats, each only one radioactive peak was shown, also similar to {sup 137}CsCl solution. Moreover, these peaks appeared at the same position. On the other hand, the peak positions absorbed at OD{sub 280nm} in the samples were different from those of each radioactive peak. It was so suggested that {sup 137}Cs accumulated in the killifish`s meat was shown not to be binding to protein`s composition. Furthermore, as the results on thin-layer chromatography, ion-exchange resin chromatography and reaction with {sup 137}Cs in samples and ammonium phosphomolybdate, {sup 137}Cs in the NPNC fraction of the killifish`s meat was not almost different from those of each control and {sup 137}CsCl solution. (author)

  5. Exposure of a herbivorous fish to 134Cs and 137Cs from the riverbed following the Fukushima disaster

    International Nuclear Information System (INIS)

    Tsuboi, Jun-ichi; Abe, Shin-ichiro; Fujimoto, Ken; Kaeriyama, Hideki; Ambe, Daisuke; Matsuda, Keishi; Enomoto, Masahiro; Tomiya, Atsushi; Morita, Takami; Ono, Tsuneo; Yamamoto, Shoichiro; Iguchi, Kei'ichiro

    2015-01-01

    Ayu Plecoglossus altivelis, a herbivorous fish, is an important fishery resource and key component of the foodweb in many Japanese streams. Radionuclide contamination of this species is likely transferred to higher trophic levels, include humans, in the food chain. After the Fukushima accident in March 2011, ayu were exposed to highly contaminated silt while feeding on algae attached to the riverbed stones. To understand the route by which herbivorous fish are exposed to radionuclides, the activity concentrations of sum of 134 Cs and 137 Cs (radiocesium) were analyzed in riverbed samples (algae and silt) and in the internal organs and the muscle of ayu in five river systems in the Fukushima Prefecture between summer 2011 and autumn 2013. Although there was a positive correlation between the radiocesium activity concentrations in the muscle and the internal organs of ayu, the median activity concentration in the muscle was much lower than those in the internal organs. The activity concentrations of radiocesium in the riverbed samples and the internal organs and the muscle of ayu were correlated with contamination levels in soil samples taken from the watershed upstream of the sample sites. The results of the generalized linear mixed models suggest that the activity concentrations in both the internal organs and the muscle of ayu declined over time. Additionally, the activity concentrations in the internal organs were correlated with those in the riverbed samples that were collected around the same time as the ayu. The activity concentrations in the muscle were correlated with ayu body size. Our results suggest that ayu ingest 134 Cs and 137 Cs while grazing silt and algae from the riverbed, and a part of the 134 Cs and 137 Cs is assimilated into the muscle of the fish. - Highlights: • The radiocesium (sum of 134 Cs and 137 Cs) concentrations in a herbivorous fish were measured following the Fukushima disaster. • The muscle concentrations were correlated with

  6. Estudio de la región rica en Bi2O3 en el sistema binario ZnO-Bi2O3

    Directory of Open Access Journals (Sweden)

    Caballero, A. C.

    2004-08-01

    Full Text Available Ceramic materials based in the ZnO- Bi2O3 system have their principal application as varistors. The binary system ZnO-Bi2O3 is specially relevant to the formation of the microstructure responsable of the varistor behaviour. The study of the different equilibrium phases at high temperatures at the Bi2O3-rich region of the ZnO-Bi2O3 will allow a correct understanding of the microstructural development. Equilibrium phases have been analyzed by XRD, SEM and DTA. Different temperature treatments of samples formulated in the Bi2O3 rich region of the ZnO-Bi2O3 binary system have allowed to determine the phase 19Bi2O3•ZnO as the equilibrium one instead of the 24Bi2O3•ZnO phase.Los materiales cerámicos basados en el sistema binario ZnO-Bi2O3 tienen su principal aplicación en el campo de los varistores. El sistema binario ZnO-Bi2O3 resulta especialmente relevante para la formación de la microestructura funcional de varistores. La determinación de las diferentes fases en equilibrio a alta temperatura en la región rica en Bi2O3 en el sistema binario ZnO-Bi2O3 permitirá interpretar correctamente el desarrollo microestructural. El estudio de las fases en equilibrio se ha llevado a cabo mediante difracción de rayos X, microscopía electrónica de barrido (MEB y análisis térmico diferencial (ATD. Tratamientos a diferentes temperaturas, en la zona rica en Bi2O3 del sistema, han permitido determinar la presencia del compuesto 19Bi2O3•ZnO como fase estable en equilibrio, en lugar del compuesto 24Bi2O3•ZnO.

  7. TiO2/Bi2(BDC)3/BiOCl nanoparticles decorated ultrathin nanosheets with excellent photocatalytic reaction activity and selectivity

    International Nuclear Information System (INIS)

    Zhou, Shu-Mei; Ma, De-Kun; Cai, Ping; Chen, Wei; Huang, Shao-Ming

    2014-01-01

    Graphical abstract: TiO 2 /Bi 2 (BDC) 3 /BiOCl nanoparticles decorated ultrathin nanosheets showed excellent photocatalytic reaction activity and selectivity. - Highlights: • TiO 2 /Bi 2 (BDC) 3 /BiOCl nanoparticles decorated ultrathin nanosheets were synthesized through a facile hydrothermal process. • The products showed excellent photocatalytic activities for the degradation of various dyes. • The photocatalytic activities of the composite materials could be easily adjusted through tuning the content of TiO 2 . • TiO 2 /Bi 2 (BDC) 3 /BiOCl displayed obvious photocatalytic selectivity in mixed dyes systems of rhodamine B and eosin Y. - Abstract: Photocatalysts with excellent photocatalytic reaction activity and ideal selectivity are highly desirable for pollutants clearance and purification of targeted organics from a mixture. Continued efforts toward the goal, we here present a facile hydrothermal route to synthesize TiO 2 /Bi-benzenedicarboxylate/BiOCl nanoparticles decorated ultrathin nanosheets with a thickness less than 5 nm on a large scale. The as-synthesized products showed excellent photocatalytic activities for the degradation of various dyes such as rhodamine B, eosin Y and methylene blue in aqueous solution under visible light irradiation. The photocatalytic activities of TiO 2 /Bi-benzenedicarboxylate/BiOCl nanocomposites for the degradation of rhodamine B and eosin Y could be adjusted through tuning the content of TiO 2 . With increasing the amount of TiO 2 , the composites showed declining photocatalytic activities in decomposing of rhodamine B while on the contrary they displayed enhanced photocatalytic activities in decomposing of eosin Y. Interestingly, TiO 2 /Bi-benzenedicarboxylate/BiOCl composite nanosheets showed obvious photocatalytic selectivity in a mixed dyes system. The photocatalytic reaction and selectivity mechanisms of the nanocomposites for the degradation of the dyes were discussed on the basis of experimental results. The

  8. Vitamin D Actions on CD4+ T cells in Autoimmune Disease

    Directory of Open Access Journals (Sweden)

    Colleen Elizabeth Hayes

    2015-03-01

    Full Text Available This review summarizes and integrates research on vitamin D and CD4+ T lymphocyte biology to develop new mechanistic insights into the molecular etiology of autoimmune disease. A deep understanding of molecular mechanisms relevant to gene-environment interactions is needed to deliver etiology-based autoimmune disease prevention and treatment strategies. Evidence linking sunlight, vitamin D, and the risk of multiple sclerosis and type 1 diabetes is summarized to develop the thesis that vitamin D is the environmental factor that most strongly influences autoimmune disease development. Evidence for CD4+ T cell involvement in autoimmune disease pathogenesis and for paracrine calcitriol signaling to CD4+ T lymphocytes is summarized to support the thesis that calcitriol is sunlight’s main protective signal transducer in autoimmune disease risk. Animal modeling and human mechanistic data to support the view that vitamin D probably influences thymic negative selection, effector Th1 and Th17 pathogenesis and responsiveness to extrinsic cell death signals, FoxP3+CD4+ Treg cell and CD4+ Tr1 cell functions, and a Th1-Tr1 switch. The proposed Th1-Tr1 switch appears to bridge two stable, self-reinforcing immune states, pro- and anti-inflammatory, each with a characteristic gene regulatory network. The bi-stable switch would enable T cells to integrate signals from pathogens, hormones, cell-cell interactions, and soluble mediators and respond in a biologically appropriate manner. Finally, we highlight unanswered questions that potentially informative future research directions that may speed delivery of etiology-based strategies to reduce autoimmune disease.

  9. The concentration of 137Cs and stable Cs in zooplankton in the western North Pacific in relation to their taxonomic composition

    International Nuclear Information System (INIS)

    Kaeriyama, Hideki; Watabe, Teruhisa; Kusakabe, Masashi

    2008-01-01

    The objective of this study is to obtain information on the background level of 137 Cs in zooplankton in the waters close to Rokkasho-mura in Aomori Prefecture, Japan, where a large-scale project has been progressively promoted to establish the nuclear fuel cycle. Prior to the full-scale operation of the spent nuclear fuel reprocessing plant, zooplankton samples were collected in May and October 2005, June 2006, and June 2007 from the surface water (0-5 m depth). The samples were analyzed to determine the concentrations of 137 Cs and stable Cs in relation to taxonomic composition. The numerical abundance of the plankton varied from 253 to 1514 inds. m -3 . Taxonomic composition differed between the two sampling periods. Although copepods formed the most abundant taxonomic group during both seasons, gelatinous plankton (chaetognaths, siphonophores, appendicularians and doliolids) were more abundant in October 2005 than in June 2006 and June 2007. The concentration of 137 Cs in zooplankton varied from 11 to 24 mBq kg-WW -1 . At the same station, the 137 Cs concentration in zooplankton in October 2005 was almost twice as much as that in June 2006, although the concentration of 137 Cs in seawater did not show a difference. The concentration of stable Cs was measured for each taxonomic group: that in gelatinous zooplankton (chaetognaths) was higher than that in crustacean zooplankton (copepods, euphausiids and amphipods). These results suggest that the concentration of 137 Cs in zooplankton is affected by the occurrence of gelatinous zooplankton. (author)

  10. Thermoelectric power of Bi and Bi{sub 1{minus}x}Sb{sub x} alloy thin films and superlattices grown by MBE

    Energy Technology Data Exchange (ETDEWEB)

    Cho, S; DiVenere, A; Wong, G K; Ketterson, J B; Meyer, J R; Hoffman, C A

    1997-07-01

    The authors have measured the thermoelectric power (TEP) of MBE-grown epitaxial Bi and Bi{sub 1{minus}x} alloy thin films and superlattices as a function of temperature in the range 20--300 K. They have observed that the TEP of a Bi thin film of 1 {micro}m thickness is in good agreement with the bulk single crystal value and that the TEPs for superlattices with 400 {angstrom} and 800 {angstrom} Bi well thicknesses are enhanced over the bulk values. For x = 0.072 and 0.088 in Bi{sub 1{minus}x}Sb{sub x} thin films showing semiconducting behavior, TEP enhancement was observed by a factor of two. However as Bi or Bi{sub 1{minus}x}Sb{sub x} well thickness decreases in superlattice geometry, the TEP decreases, which may be due to unintentional p-type doping.

  11. Pre-assessment of dose rates of (134)Cs, (137)Cs, and (60)Co for marine biota from discharge of Haiyang Nuclear Power Plant, China.

    Science.gov (United States)

    Li, Jingjing; Liu, Senlin; Zhang, Yongxing; Chen, Ling; Yan, Yuan; Cheng, Weiya; Lou, Hailin; Zhang, Yongbao

    2015-09-01

    Haiyang Nuclear Power Plant to be built in China was selected as a case for the dose pre-assessment for marine biota in this study. The concentrations of Cs and Co in organisms (turbot, yellow croaker, swimming crab, abalone, sea cucumber, and sea lettuce), seawater, and bottom sediment sampled on-site were measured by neutron activation analysis, and the site-specific transfer parameters (concentration ratios and distribution coefficients) of Cs and Co were calculated. (134)Cs, (137)Cs, and (60)Co activity concentrations in the organisms and the sediment at the site were calculated with the site-specific transfer parameters and the anticipated activity concentrations in the liquid effluent of the nuclear power plant. The ERICA tool was used to estimate the dose rates of (134)Cs, (137)Cs, and (60)Co to the selected organisms based on the biological models developed. The total dose rates of (134)Cs, (137)Cs, and (60)Co to the six organisms were all <0.001 μGy h(-1). Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Cs-137 in Arctic foxes (Alopex lagopus) on Svalbard

    International Nuclear Information System (INIS)

    Gwynn, Justin P.; Fuglei, Eva; Dowdall, Mark

    2007-01-01

    This study presents 137 Cs muscle activity concentrations in Arctic foxes (Alopex lagopus) from Svalbard over a period of several years and discusses the transfer of 137 Cs to Arctic foxes through likely predator-prey relationships. Mean 137 Cs activity concentrations and 137 Cs T ag values (per trapping season) ranged from 0.51 ± 2.76 to 1.32 ± 2.89 Bq/kg (w.w.) and 5.1 x 10 -4 to 1.3 x 10 -3 m 2 /kg, respectively. Mean concentration ratios of 137 Cs in Arctic foxes compared to probable prey ranged from 1.0 to 7.9. On Svalbard, transfer of 137 Cs to Arctic foxes is likely to occur via both marine and terrestrial food chains. The relative contribution of marine and terrestrial food sources to the diet of Arctic foxes may vary by location and by season and may lead to either an increase or decrease in the trophic transfer of 137 Cs to Arctic foxes compared to transfer resulting from terrestrial only diets

  13. BiP Negatively Affects Ricin Transport

    Directory of Open Access Journals (Sweden)

    Kirsten Sandvig

    2013-05-01

    Full Text Available The AB plant toxin ricin binds both glycoproteins and glycolipids at the cell surface via its B subunit. After binding, ricin is endocytosed and then transported retrogradely through the Golgi to the endoplasmic reticulum (ER. In the ER, the A subunit is retrotranslocated to the cytosol in a chaperone-dependent process, which is not fully explored. Recently two separate siRNA screens have demonstrated that ER chaperones have implications for ricin toxicity. ER associated degradation (ERAD involves translocation of misfolded proteins from ER to cytosol and it is conceivable that protein toxins exploit this pathway. The ER chaperone BiP is an important ER regulator and has been implicated in toxicity mediated by cholera and Shiga toxin. In this study, we have investigated the role of BiP in ricin translocation to the cytosol. We first show that overexpression of BiP inhibited ricin translocation and protected cells against the toxin. Furthermore, shRNA-mediated depletion of BiP enhanced toxin translocation resulting in increased cytotoxicity. BiP-dependent inhibition of ricin toxicity was independent of ER stress. Our findings suggest that in contrast to what was shown with the Shiga toxin, the presence of BiP does not facilitate, but rather inhibits the entry of ricin into the cytosol.

  14. Studies of the synthesis and deposition of Cu3BiS 3 for use in photovoltaic devices

    Science.gov (United States)

    Epstein, Joshua A.

    As the world's climate continues to change, alternative energy is being adopted more and more. Solar energy is one extremely promising candidate to supplement our ever increasing energy needs. In order for it to be a viable solution, more efficient and less expensive solar panels must be made. While silicon solar panels are the current market leader their high manufacturing energy input and cost warrant looking into alternatives. Many thin film solar materials are being investigated such as CdTe, CIGS and CZTS, but all come with their own drawbacks. With a near ideal band gap, low toxicity and earth abundant elemental make up copper bismuth sulfide, Cu3BiS3, is a promising candidate for use in future photovoltaic devices. The research presented here details multiple methods to synthesize and deposit this material with an effort to keep the methods low cost, energy efficient and environmentally friendly. Multiple low temperature solvothermal routes to synthesizing copper bismuth sulfide, CBS, have been developed. The resulting powders have been verified as pure Cu3BiS3 via XRD peak matching. The precursor reactants tested for use were copper and bismuth nitrates, acetates, chlorides and hydroxides. L-cystine, L-cysteine, thiourea and CS2 have all been tested for use as sulfur sources. Seven of these combinations produced pure CBS powders. Two custom built benchtop reactors have been designed and fabricated with the aim of studying the possibility of a continuous flow reactor as a way to utilize these precipitation chemistries for making thin films of CBS. Heat and liquid flow simulations were performed in COMSOL multiphysics to assist in the reactor design process. The second reactor was designed to promote uniform liquid flow across the fluorine doped, tin oxide coated, FTO, glass. This reactor was also built with a temperature gradient transverse to the liquid flow so that the optimal temperature for the deposition of CBS could be evaluated. This reactor was also

  15. Long-term distribution of Cs-137 in freshwater ecosystem and the effect of bioturbation on leakage of Cs-137 from the sediments

    International Nuclear Information System (INIS)

    Aquilonius, K.

    1995-06-01

    The first aim of the project was to make a literature compilation regarding Cs-137 in freshwater systems. Secondly, in order to follow up the long-term behaviour of Cs-137 in Lake Hillesjoen, sediment and water was sampled with respect to Cs-137. Finally, an experiment was done with chironomids, with the aim to assess the impact of bioturbation on the leakage of Cs-137 from the sediment, since this is one of the factors contributing to the uncertainties in radioecological models. Some aspects of long-term distribution of Cs-137 in freshwater lakes is discussed. In lake Hillesjoen the pool of Cs-137 in sediments (225 kBq/m 2 , 1993) has gradually increased since the Chernobyl accident, and now exceeds the initial deposition (100 kBq/m 2 ). The effect of bioturbation on the leakage from the sediment to the water could not be clarified in this experiment, but is discussed. 40 refs

  16. Digital signal processing for CdTe detectors using VXIbus data collection systems

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Daiji; Takahashi, Hiroyuki; Kurahashi, Tomohiko; Iguchi, Tetsuo; Nakazawa, Masaharu

    1996-07-01

    Recently fast signal digitizing technique has been developed, and signal waveforms with very short time periods can be obtained. In this paper, we analyzed each measured pulse which was digitized by an apparatus of this kind, and tried to improve an energy resolution of a CdTe semiconductor detector. The result of the energy resolution for {sup 137}Cs 662 keV photopeak was 13 keV. Also, we developed a fast data collection system based on VXIbus standard, and the counting rate on this system was obtained about 50 counts per second. (author)

  17. Synthesis, thermal decomposition and sensitivity study of CsDNBF

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shaozong; Zhang, Tonglai; Yang, Li; Zhang, Jianguo; Sun, Yuanhua [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China)

    2007-02-15

    CsDNBF (cesium 7-hydroxy-4,6-dinitro-5,7-dihydrobenzofuroxanide) was synthesized from the sodium salt of DNBF and cesium nitrate. The thermal decomposition process has been investigated and the results show that the solid residues at 240 C are RCOOCs, CsNCO, RNO{sub 2} and CsNO{sub 3}. The sensitivity results demonstrate that CsDNBF has better properties than KDNBF, which has been widely used. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  18. Composite detector for mixed radiations based on CsI(Tl) and dispersions of small ZnSe(Te) crystals

    International Nuclear Information System (INIS)

    Ryzhikov, V.; Gal'chinetskii, L.; Katrunov, K.; Lisetskaya, E.; Gavriluk, V.; Zelenskaya, O.; Starzhynskiy, N.; Chernikov, V.

    2005-01-01

    A new large area detector of high-energy X-ray and β-radiation has been designed and studied. A composite material based on small-crystalline ZnSe(Te) was applied onto the wide surface of a light guide. An experimental specimen has been prepared, which showed β-sensitivity C β =5.5cm 2 . The spectrograms of a 90 Sr+ 90 Y β-source obtained with the specimen under study make it possible to evaluate the age of the source by the ratio of low- and high-energy regions of the spectrum. The combined detector (CD) comprises a single crystalline plate of ZnSe(Te) placed onto the output window of a scintillating transparent light guide made of CsI(Tl) in the shape of a truncated pyramid. The CsI(Tl) light guide is used to create an additional channel for detection of γ-radiation, as well as for protecting the photodiode from the penetrating radiation. It is shown that introduction of the light guide does not worsen the energy resolution characteristics of ZnSe(Te). Separate detection of α- and γ-radiation has been achieved under simultaneous excitation by 239 Pu (ZnSe(Te), R α =6%) and 241 Am (CsI(Tl), R γ =20%). The use of selective optical filters allows separation of the peaks of total absorption (p.t.a.) in the case of their superposition

  19. Chemical information on tank supernatants, Cs adsorption from tank liquids onto Hanford sediments, and field observations of Cs migration from past tank leaks

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R.J.; Zachara, J.M.; Burke, D.S.

    1998-01-01

    Borehole gamma-logging profiles beneath the SX-Tank Farm suggest that contamination from Cs-137 extends to at least a depth of 40 m (130 ft), and may extend even deeper. What is presently not known is the pathway that Cs-137 has taken to reach these depths. In this report we provide an analysis of the chemistry of tank supernates with emphasis on the REDOX waste stream disposed in SX tanks, Cs chemistry in aqueous solutions and adsorption properties onto minerals, available data on Cs adsorption onto Hanford sediments, and information on Cs migration from other Hanford tank leaks that have been studied. The data in this report was used to help guide the vadose zone transport analysis of the SX Tank Farm presented in a companion report. The goal of the vadose zone transport modelling is to attempt to explain the depth and extent of the Cs-137 plume under the SX Tank farm, specifically in the vicinity of the greatest leak, near the SX-109 Tank as inferred from the gamma logs (DOE 1996). In solution Cs is present as the monovalent cation and shows very little tendency to form aqueous complexes with inorganic or organic ligands. Cs is expected to adsorb primarily onto selective minerals that have unique adsorption sites. The small Cs{sup +} ion is accommodated on these frayed edge and interlayer sites. Adsorption within the interlayers often leads to collapse of the layers such that the Cs{sup +} ion is effectively trapped and not readily exchangeable by all other common cations. The degree of adsorption is thus only moderately dependent on the types and high concentrations of other cations in leaking tank liquors.

  20. Chemical information on tank supernatants, Cs adsorption from tank liquids onto Hanford sediments, and field observations of Cs migration from past tank leaks

    International Nuclear Information System (INIS)

    Serne, R.J.; Zachara, J.M.; Burke, D.S.

    1998-01-01

    Borehole gamma-logging profiles beneath the SX-Tank Farm suggest that contamination from Cs-137 extends to at least a depth of 40 m (130 ft), and may extend even deeper. What is presently not known is the pathway that Cs-137 has taken to reach these depths. In this report we provide an analysis of the chemistry of tank supernates with emphasis on the REDOX waste stream disposed in SX tanks, Cs chemistry in aqueous solutions and adsorption properties onto minerals, available data on Cs adsorption onto Hanford sediments, and information on Cs migration from other Hanford tank leaks that have been studied. The data in this report was used to help guide the vadose zone transport analysis of the SX Tank Farm presented in a companion report. The goal of the vadose zone transport modelling is to attempt to explain the depth and extent of the Cs-137 plume under the SX Tank farm, specifically in the vicinity of the greatest leak, near the SX-109 Tank as inferred from the gamma logs (DOE 1996). In solution Cs is present as the monovalent cation and shows very little tendency to form aqueous complexes with inorganic or organic ligands. Cs is expected to adsorb primarily onto selective minerals that have unique adsorption sites. The small Cs + ion is accommodated on these frayed edge and interlayer sites. Adsorption within the interlayers often leads to collapse of the layers such that the Cs + ion is effectively trapped and not readily exchangeable by all other common cations. The degree of adsorption is thus only moderately dependent on the types and high concentrations of other cations in leaking tank liquors

  1. Absorption spectra of CsNd(MoO4)2 and CsGd(MoO4)2-Nd3+ crystals in strong magnetic fields

    International Nuclear Information System (INIS)

    Gorban', I.S.; Kozeeva, L.P.; Slobodyanyuk, A.V.; Shevchenko, V.A.

    1987-01-01

    The comparison of the electronic structure of Nd 3+ in CsNd(MoO 4 ) 2 and CsGd(MoO 4 ) 2 - Nd 3+ crystals is made. It is established that in these crystals the activator centers, mainly, of the certain type with the symmetry of the local environment C 2 are formed. The absorption spectra of self-activated CsNd(MoO 4 ) 2 crystal differ from spectra of CsGd(MoO 4 ) 2 - Nd 3+ by the presence of the vibrating structure. The Stark splittings of energy levels of Nd 3+ in the investigated crystalline matrices are more sensitive to the environment effect than the Zeeman ones. The ground state of Nd 3+ ion in CsNd(MoO 4 ) 2 and CsGd(MoO 4 ) 2 molybdates is characterized by the similar values of g-factors

  2. 133Cs NMR investigation of 2D frustrated Heisenberg antiferromagnet, Cs2CuCl4

    Science.gov (United States)

    Vachon, M.-A.; Kundhikanjana, W.; Straub, A.; Mitrovic, V. F.; Reyes, A. P.; Kuhns, P.; Coldea, R.; Tylczynski, Z.

    2006-10-01

    We report 133Cs nuclear magnetic resonance (NMR) measurements on the 2D frustrated Heisenberg antiferromagnet Cs2CuCl4 down to 2 K and up to 15 T. We show that 133Cs NMR is a good probe of the magnetic degrees of freedom in this material. Cu spin degrees of freedom are sensed through a strong anisotropic hyperfine coupling. The spin excitation gap opens above the critical saturation field. The gap value was determined from the activation energy of the nuclear spin-lattice relaxation rate in a magnetic field applied parallel to the Cu chains (\\skew3\\hat{b} axis). The values of the g-factor and the saturation field are consistent with the neutron-scattering and magnetization results. The measurements of the spin spin relaxation time are exploited to show that no structural changes occur down to the lowest temperatures investigated.

  3. Initial interaction of {sup 137}Cs with soils

    Energy Technology Data Exchange (ETDEWEB)

    Nagasaki, S., E-mail: nagasaki@mcmaster.ca [McMaster Univ., Hamilton, Ontario (Canada); Makino, H.; Saito, T. [Univ. of Toyko, Tokyo (Japan)

    2013-07-01

    It is critical to understand the physicochemical behaviour of Cs in soil in order to progress the decontamination of soils which were contaminated by nuclear power plant accident and to improve the reliability of safety assessment of used nuclear fuel disposal. In this paper, the initial interactions of {sup 137}Cs with soils, which were sampled in Fukushima 38 days after Fukushima Accident, were investigated with sequential extraction method. It was found that there were fast and slow processes of fixation of {sup 137}Cs in clay minerals and that the organic substances might play an important role on kinetics of {sup 137}Cs in soils. (author)

  4. Different thresholds of T cell activation regulate FIV infection of CD4+CD25+ and CD4+CD25- cells

    International Nuclear Information System (INIS)

    Joshi, Anjali; Garg, Himanshu; Tompkins, Mary B.; Tompkins, Wayne A.

    2005-01-01

    Cellular activation plays an important role in retroviral replication. Previously, we have shown that CD4 + CD25 + T cells by the virtue of their partially activated phenotype represent ideal candidates for a productive feline immunodeficiency virus (FIV) infection. In the present study, we extended our previous observations with regard to FIV replication in CD4 + CD25 + and CD4 + CD25 - cells under different stimulation conditions. Both CD4 + CD25 + and CD4 + CD25 - cells remain latently infected in the absence of IL-2 or concanvalinA (ConA), respectively; harboring a replication competent provirus capable of reactivation several days post-infection. While CD4 + CD25 + cells require low levels of exogenous IL-2 and virus inputs for an efficient FIV replication, CD4 + CD25 - T cells can only be productively infected in the presence of either high concentrations of IL-2 or high virus titers, even in the absence of mitogenic stimulation. Interestingly, while high virus input activates CD4 + CD25 - cells to replicate FIV, it induces apoptosis in a high percentage of CD4 + CD25 + T cells. High IL-2 concentrations but not high virus inputs lead to surface upregulation of CD25 and significant cellular proliferation in CD4 + CD25 - cells. These results suggest that CD4 + CD25 + and CD4 + CD25 - T cells have different activation requirements which can be modulated by both viral and cytokine stimuli to reach threshold activation levels in order to harbor a productive FIV infection. This holds implications in vivo for CD4 + CD25 + and CD4 + CD25 - cells to serve as potential reservoirs of a productive and latent FIV infection

  5. Thermoelectric properties of Bi2Te3 base solid solutions in the Bi2Te3-InS system

    International Nuclear Information System (INIS)

    Safarov, M.G.; Rustamov, P.G.; Alidzhanov, M.A.

    1979-01-01

    The rich Bi 2 Te 3 part ot the Bi 2 Te 3 -InS constitutional diagram has been studied with a view to produce new Bi 2 Te 3 -based solid solutions and to establish the maximum solubility of InS in Bi 2 Te 3 . The methods of differential-thermal, X-ray phase and microstructural analysis have been used. The alloys microhardness, density and thermal electric properties have been measured. A large region of Bi 2 Te 3 -based restricted solid solutions has been detected; it reaches 14.0 mol.% InS at room temperature. Studied have been the thermoelectromotive forces, electric and thermal conductivity of the alloys, containing up to 5 mol.% InS in the 300-700 K temperature range

  6. Uptake of Cs 137 from farmland 1986-1989

    International Nuclear Information System (INIS)

    Holmberg, M.

    1986-12-01

    The basic mechanisms of the accumulation of Cs 137 in grass, corn, oleiferous plants, potatoes etc are described. It is also presented as a function of time after the deposition. Transport of Cs 137 to milk, meat and bacon is described. A prognosis of Cs 137 in food products for the coming two years is made on basis of the estimated data. (G.B.)

  7. 137Cs in man due to nuclear fallout

    International Nuclear Information System (INIS)

    Poulheim, K.F.

    1981-01-01

    137 Cs has been determined in man with the aid of a whole-body counter. It is shown that the specific 137 Cs content (as related to the potassium content in man) continuously decreased from 1965 through 1974. After a slight increase in 1975, possibly caused by a Chinese atmospheric nuclear test in June 1974, the 137 Cs content again decreased in the following years. (author)

  8. Optical spectroscopy and Fermi surface studies of BiTeCl and BiTeBr

    Science.gov (United States)

    Martin, Catalin; Suslov, A. V.; Buvaev, S.; Hebard, A. F.; Bugnon, Philippe; Berger, Helmuth; Magrez, Arnaud; Tanner, D. B.

    2014-03-01

    The observation of a large bulk Rashba effect in the non-centrosymmetric semiconductors BiTeX(X=Cl, Br, I) has stimulated the interest in these sys- tems, as promising candidates for studying spin related phenomena and for the realization of spin devices. Here we present a comparative study of the electronic properties of BiTeCl and BiTeBr, determined from temperature dependent infrared spectroscopy and Shubnikov-de Haas oscillations. In par- ticular, we compare the angle dependence of quantum oscillations between the two compounds and discuss possible differences between the topology of their Fermi surfaces. Supported by NSF Cooperative Agreement DMR-1157490 to the National High Magnetic Field Laboratory.

  9. Co60 and Cs137 gamma radiation effects on textured bscco Superconducting fibers

    International Nuclear Information System (INIS)

    Leyva Fabelo, A.; Bouza Dominguez, J.; Cruz Inclan, Crlos M.

    2001-01-01

    Bi2Sr2CaCu2Ox superconducting fibers synthesized by solid state reaction and textured by the method of zonal laser ablation were irradiated with gamma rays of 1.25 MeV and 662 keV and studied the behavior of some of its properties with the exposition dose. The measurements of dynamic magnetic susceptibility were used for the characterization of the samples. It was observed that for the dose of up to 600 kGy in the case of the Co60 and until 500 mGy for the Cs137, the fibers preserve its superconducting intragrain properties. It is an evidence of the high resistance of the material to the radiacional damage. In all the cases were verified that with the increase of the dose the Ton of the transition grows. Two possible mechanisms that play the most important role in this effect are explained in the text. The ac measurements allowed to verified the increasing behavior of the superconducting volume fraction in the sample with the exposition dose

  10. The radiation chemistry of the Cs-7SB modifier used in Cs and Sr extraction

    International Nuclear Information System (INIS)

    Swancutt, Katy L.; Cullen, Thomas D.; Mezyk, Stephen P.; Elias, Gracy; Bauer, William F.; Peterman, Dean R.; Riddle, Catherine L.; Ball, R. Duane; Mincher, Bruce J.; Muller, James J.

    2011-01-01

    The compound 1-(2,2,3,3,-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol, also called Cs-7SB, is used as a solvent modifier in formulations containing calixarenes and crown ethers for cesium and/or strontium extraction from nuclear waste solutions. The compound solvates complexes of both metals and concentration decreases result in lowered extraction efficiency for both. The use of Cs-7SB in nuclear solvent extraction ensures that it will be exposed to high radiation doses, and thus its radiation chemical robustness is a matter of interest in the design of extraction systems employing it. The behavior of the compound in irradiated solution, both in the presence and absence of a nitric acid aqueous phase was investigated here using steady state and pulsed radiolysis techniques. The rate constants for the aqueous reactions of Cs-7SB with H, OH, NO 3 and NO 2 radicals are reported. UPLC-UV-MS results were used to identify major products of the radiolysis of Cs-7SB in contact with nitric acid, and revealed the production of hydroxylated nitro-derivatives. Reaction mechanisms are proposed and it is concluded that the aryl ether configuration of this molecule makes it especially susceptible to nitration in the presence of radiolytically-produced nitrous acid. Fluoride yields are also given under various conditions.

  11. Measurement limits to 134Cs concentration in soil

    International Nuclear Information System (INIS)

    Ahn, J.K.; Kim, J.S.; Lee, H.M.; Kim, H.; Kim, T.H.; Park, J.N.; Kang, Y.S.; Lee, H.S.; Kim, S.J.; Park, J.Y.; Ryu, S.Y.; Kim, H.-Ch.; Kang, W.G.; Kim, S.K.

    2011-01-01

    We investigate the caesium concentrations in soils in mountain areas near Gori nuclear power plant in Korea, focusing on the measurement limits to the 134 Cs. In order to lower the minimum detectable amount (MDA) of activity for the 134 Cs, we have used the ammonium molybdophosphate (AMP) precipitation method to get rid of the 40 K existing in natural radioactivity, which reduces the MDA activity about 10 times smaller than those without the AMP precipitation method. The MDA results for the 134 Cs were found to be in the range between 0.015 and 0.044 Bq/kg-dry weight. In order to diminish the background, we also have measured a part of the soil samples in Yangyang, a small town in the east coast of Korea. However, it turns out that in order to detect the 134 Cs in the samples the MDA should be reduced to the level of mBq/kg-dry weight. - Highlights: → We study the caesium concentrations in soils in mountain areas near Gori NPT in Korea. → We use the AMP precipitation method to lower the minimum detectable amount (MDA) of activity for the 134 Cs. → The results of the MDA for the 134 Cs turn out to be in the range between 0.015 and 0.044. → In order to detect the 134 Cs in the samples, the MDA should be reduced to the level of mBq/kg-dry weight.

  12. Bi-cooperative games in bipolar fuzzy settings

    Science.gov (United States)

    Hazarika, Pankaj; Borkotokey, Surajit; Mesiar, Radko

    2018-01-01

    In this paper, we introduce the notion of a bi-cooperative game with Bipolar Fuzzy Bi-coalitions and discuss the related properties. In many decision-making situations, players show bipolar motives while cooperating among themselves. This is modelled in both crisp and fuzzy environments. Bi-cooperative games with fuzzy bi-coalitions have already been proposed under the product order of bi-coalitions where one had memberships in [0, 1]. In the present paper, we adopt the alternative ordering: ordering by monotonicity and account for players' memberships in ?, a break from the previous formulation. This simplifies the model to a great extent. The corresponding Shapley axioms are proposed. An explicit form of the Shapley value to a particular class of such games is also obtained. Our study is supplemented with an illustrative example.

  13. Improvement of the sensitivity of CdTe detectors in the high energy regions

    Energy Technology Data Exchange (ETDEWEB)

    Nishizawa, Hiroshi; Ikegami, Kazunori; Takashima, Kazuo; Usami, Teruo [Mitsubishi Electric Corp., Tokyo (Japan); Yamamoto, Takayoshi

    1996-07-01

    In order to improve the efficiency of the full energy peak in the high energy regions, we had previously suggested a multi-layered structure of CdTe elements and have since confirmed the sensitivity improvement of the full energy peak. And furthermore, we have suggested a new type structure of multi-layered elements in this paper and we confirmed that the efficiency of the full energy peak became higher and that more proper energy spectra were obtained by our current experiment than by the detector with the conventional structure. This paper describes a simulation and experiment to improve the efficiency of the full energy peak and to obtain the more proper energy spectra of {sup 137}Cs (662keV) and {sup 60}Co (1.17 and 1.33MeV) using the new structure of CdTe detector. (J.P.N.)

  14. Prototype of the stacked CdZnTe semiconductor detector for 16N measurement

    International Nuclear Information System (INIS)

    Nishizawa, Hiroshi; Inujima, Hiroshi; Fujiwara, Hirotsugu; Nakamura, Hiroaki

    2001-01-01

    Prototype of the Stacked CdZnTe Semiconductor Detector for Measurement The prototype model of the stacked CdZnTe semiconductor detector, which is able to measure the 6.13 MeV γ-ray from 16 N, was fabricated. The prototype's response calculation was carried out by Monte-Carlo method. The result of the response calculation agreed with the experiment data of check sources of 137 Cs and 60 Co, and 16 N which was measured at vicinity of the primary cooling water pipe of the nuclear reactor. The source spectra were unfolded with detector's response function obtained by simulation, and it is indicated that the incident γ-ray energy and its intensity ratio was identified and that the energy of 6 MeV γ-ray could be measured by the prototype of the stacked detector. (author)

  15. 134Cs and 137Cs whole-body measurements and internal dosimetry of the population living in areas contaminated by radioactivity after the Chernobyl accident

    International Nuclear Information System (INIS)

    Zvonova, I.A.; Jesko, T.V.; Balonov, M.I.; Danilova, I.O.; Wallstroem, E.; Alpsten, M.; Thornberg, C.; Mattsson, S.

    1995-01-01

    Six western districts of the Bryansk region, Russia, were heavily contaminated with radioactive fallout after the Chernobyl NPP accident. Annually, between 1991 and 1994, inhabitants of four settlements were studied. Whole-body 134+137 Cs contents were measured in about 500 inhabitants. No correlation between Cs whole-body content and Cs soil contamination was found; Cs accumulation in a body depends greatly on natural factors such as type of soil, on social factors such as food habits including consumption of forest products, and on countermeasures to reduce internal exposure. During 1991-1994 average whole-body content of 134+137 Cs in adult inhabitants was about 3-60 kBq, corresponding to an effective dose of 0.1-2.4 mSv.y -1 . Cs whole-body content increases equally for girls and boys up to adult age. Cs content in adults does not depend significantly on age and is usually 1.2-2 times higher in men than in women. The average annual internal effective dose varies with age significantly less than 134+137 Cs whole-body content. In children (0-5 years) the mean absorbed dose is usually 1.2-1.5 times less than in adults. (author)

  16. Room-temperature synthesis of pure perovskite-related Cs4PbBr6 nanocrystals and their ligand-mediated evolution into highly luminescent CsPbBr3 nanosheets

    Science.gov (United States)

    Yang, Liu; Li, Dongmei; Wang, Cong; Yao, Wei; Wang, Hao; Huang, Kaixiang

    2017-07-01

    Currently, all-inorganic cesium lead-halide perovskite nanocrystals have attracted enormous attentions owing to their excellent optical performances. While great efforts have been devoted to CsPbBr3 nanocrystals, the perovskite-related Cs4PbBr6 nanocrystals, which were newly reported, still remained poorly understood. Here, we reported a novel room-temperature reaction strategy to synthesize pure perovskite-related Cs4PbBr6 nanocrystals. Size of the products could be adjusted through altering the amount of ligands, simply. A mixture of two good solvents with different polarity was innovatively used as precursor solvent, being one key to the high-yield Cs4PbBr6 nanocrystals synthesis. Other two keys were Cs+ precursor concentration and surface ligands. Ingenious experiments were designed to reveal the underlying reaction mechanism. No excitonic emission was observed from the prepared Cs4PbBr6 nanocrystals in our work. We considered the green emission which was observed in other reports originated from the avoidless transformation of Cs4PbBr6 into CsPbBr3 nanocrystals. Indeed, the new-prepared Cs4PbBr6 nanocrystals could transform into CsPbBr3 nanosheets with surface ligands mediated. The new-transformed two-dimensional CsPbBr3 nanosheets could evolve into large-size nanosheets. The influences of surface ligand density on the fluorescent intensity and stability of transformed CsPbBr3 nanosheets were also explained. Notably, the photoluminescence quantum yield of the as-transformed CsPbBr3 nanosheets could reach as high as 61.6% in the form of thin film. The fast large-scale synthesis of Cs4PbBr6 nanocrystals and their ligand-mediated transformation into high-fluorescent CsPbBr3 nanosheets will be beneficial to the future optoelectronic applications. Our work provides new approaches to understand the structural evolution and light-emitting principle of perovskite nanocrystals. [Figure not available: see fulltext.

  17. Soluble CD40 ligand directly alters glomerular permeability and may act as a circulating permeability factor in FSGS.

    Science.gov (United States)

    Doublier, Sophie; Zennaro, Cristina; Musante, Luca; Spatola, Tiziana; Candiano, Giovanni; Bruschi, Maurizio; Besso, Luca; Cedrino, Massimo; Carraro, Michele; Ghiggeri, Gian Marco; Camussi, Giovanni; Lupia, Enrico

    2017-01-01

    CD40/CD40 ligand (CD40L) dyad, a co-stimulatory bi-molecular complex involved in the adaptive immune response, has also potent pro-inflammatory actions in haematopoietic and non-haematopoietic cells. We describe here a novel role for soluble CD40L (sCD40L) as modifier of glomerular permselectivity directly acting on glomerular epithelial cells (GECs). We found that stimulation of CD40, constitutively expressed on GEC cell membrane, by the sCD40L rapidly induced redistribution and loss of nephrin in GECs, and increased albumin permeability in isolated rat glomeruli. Pre-treatment with inhibitors of CD40-CD40L interaction completely prevented these effects. Furthermore, in vivo injection of sCD40L induced a significant reduction of nephrin and podocin expression in mouse glomeruli, although no significant increase of urine protein/creatinine ratio was observed after in vivo injection. The same effects were induced by plasma factors partially purified from post-transplant plasma exchange eluates of patients with focal segmental glomerulosclerosis (FSGS), and were blocked by CD40-CD40L inhibitors. Moreover, 17 and 34 kDa sCD40L isoforms were detected in the same plasmapheresis eluates by Western blotting. Finally, the levels of sCD40Lwere significantly increased in serum of children both with steroid-sensitive and steroid-resistant nephrotic syndrome (NS), and in adult patients with biopsy-proven FSGS, compared to healthy subjects, but neither in children with congenital NS nor in patients with membranous nephropathy. Our results demonstrate that sCD40L directly modifies nephrin and podocin distribution in GECs. Moreover, they suggest that sCD40L contained in plasmapheresis eluates from FSGS patients with post-transplant recurrence may contribute, presumably cooperating with other mediators, to FSGS pathogenesis by modulating glomerular permeability.

  18. Soluble CD40 ligand directly alters glomerular permeability and may act as a circulating permeability factor in FSGS.

    Directory of Open Access Journals (Sweden)

    Sophie Doublier

    Full Text Available CD40/CD40 ligand (CD40L dyad, a co-stimulatory bi-molecular complex involved in the adaptive immune response, has also potent pro-inflammatory actions in haematopoietic and non-haematopoietic cells. We describe here a novel role for soluble CD40L (sCD40L as modifier of glomerular permselectivity directly acting on glomerular epithelial cells (GECs. We found that stimulation of CD40, constitutively expressed on GEC cell membrane, by the sCD40L rapidly induced redistribution and loss of nephrin in GECs, and increased albumin permeability in isolated rat glomeruli. Pre-treatment with inhibitors of CD40-CD40L interaction completely prevented these effects. Furthermore, in vivo injection of sCD40L induced a significant reduction of nephrin and podocin expression in mouse glomeruli, although no significant increase of urine protein/creatinine ratio was observed after in vivo injection. The same effects were induced by plasma factors partially purified from post-transplant plasma exchange eluates of patients with focal segmental glomerulosclerosis (FSGS, and were blocked by CD40-CD40L inhibitors. Moreover, 17 and 34 kDa sCD40L isoforms were detected in the same plasmapheresis eluates by Western blotting. Finally, the levels of sCD40Lwere significantly increased in serum of children both with steroid-sensitive and steroid-resistant nephrotic syndrome (NS, and in adult patients with biopsy-proven FSGS, compared to healthy subjects, but neither in children with congenital NS nor in patients with membranous nephropathy. Our results demonstrate that sCD40L directly modifies nephrin and podocin distribution in GECs. Moreover, they suggest that sCD40L contained in plasmapheresis eluates from FSGS patients with post-transplant recurrence may contribute, presumably cooperating with other mediators, to FSGS pathogenesis by modulating glomerular permeability.

  19. Theoretical investigation of the Cs*Hen>=3 exciplexes

    International Nuclear Information System (INIS)

    Zbiri, Mohamed; Daul, Claude

    2005-01-01

    The X 2 Σ 1/2 , A 2 Π 1/2 , B 2 Σ 1/2 , and A 2 Π 3/2 states of Cs*He n exciplexes, with n={3,...,9}, are studied using first principle density functional theory (DFT) formalism combined with the zeroth order regular approximation (ZORA). The zero points energies (ZPEs) E 0 for Cs*He n are calculated at a first step, in order to estimate the stability of the studied exciplexes. Relativistic calculations are carried out including spin-orbit effect (SO), and potential energy surfaces of Cs*He 6 are shown. The electronic distribution shapes of the studied molecules are also discussed, and their emission lines are evaluated and compared to a new discovered experimental emission spectra, which has been recently assigned, using a semi-empirical model, to Cs(AΠ 1/2 )He 7 . Our first principle calculation suggests that the discovered emission line is most probably due to a decay of Cs(AΠ 1/2 )He 6

  20. Solidification technique of radioactive elements. Research using zirconium phosphates

    International Nuclear Information System (INIS)

    Nakayama, Susumu; Ito, Katsuhiko

    2005-01-01

    Proton type zirconium phosphates HZr 2 (PO 4 ) 3 , NASICON type three-dimensional net work structure, is used for solidification of Cs in the high level radioactive waste. Two kinds of solidification methods such as the dry method and autoclave method are explained. Cs ion entered into 0.6nm space of HZr 2 (PO 4 ) 3 , and formed ionic bonding, which made the difficult situation to remove. When mixture of HZr 2 (PO 4 ) 3 and 23 kinds of M(NO 3 )n (M= Li, Na, K, Pb, Sr, Bi, Y, Mg, Ca, Sc, Mn, Fe, Co, Ni, Cu, Zn, Ag, Cd, Ba, La, Ce, Tl, and Pb; n=1,2 or 3) was treated at 400-700degC by dry method, solidification of the subject metals was succeeded. Amount of solidification of Cs by autoclave at 250degC is almost same as the dry method and its leachability resistance increased 40 times than that of dry method after heat treatment in atmosphere at 700degC. (S.Y.)

  1. Photon Reabsorption in Mixed CsPbCl3:CsPbI3 Perovskite Nanocrystal Films for Light-Emitting Diodes

    KAUST Repository

    Davis, Nathaniel J. L. K.; de la Peñ a, Francisco J.; Tabachnyk, Maxim; Richter, Johannes M.; Lamboll, Robin D.; Booker, Edward P.; Wisnivesky Rocca Rivarola, Florencia; Griffiths, James T.; Ducati, Caterina; Menke, S. Matthew; Deschler, Felix; Greenham, Neil C.

    2017-01-01

    is significantly reduced. We investigate samples containing mixtures of perovskite nanocrystals with different compositions and study the resulting optical and electrical interactions. We report excitation transfer from CsPbCl3 to CsPbI3 in solution and within a

  2. Crystal structure of CsTb(PO3)4 compound

    International Nuclear Information System (INIS)

    Palkina, K.K.; Maksimova, S.I.; Kuznetsov, V.G.; Chibiskova, N.T.

    1978-01-01

    The X-ray structural study of compounds of the CsLn(PO 3 ) 4 series has been made. Found is the presence of two structural types for CsPr(PO 3 ) 4 (cubic and monoclinic modifications), one type for CsNd(PO 3 ) 4 (cubic modification) and for CsTb(PO 3 ) 4 (monoclinic modification). For the CsTb(PO 3 ) 4 monocrystal the lattice parameters are determined: a=7.032 +- 0.001; b=8.705 +- 0.001; c=9.051 +- 0.001 A; α=90 deg, β=90 deg, γ=100 deg, Z=2, V=545.68 A 3 , dsub(exp)=3.70 g/cm 3 . The structure character is presented as infinite chains of (PO 4 ) tetrahedrons, stretched along the ''C'' period. Tb and Cs atoms are rounded by 8 atoms of oxygen. Tb polyhedron are irregular octaapexes or strongly deformed tetragonal antiprisms. Tb-Tb shortest distance is 6.59 A

  3. Modelling 137Cs uptake in plants from undisturbed soil monoliths

    International Nuclear Information System (INIS)

    Waegeneers, Nadia; Smolders, Erik; Merckx, Roel

    2005-01-01

    A model predicting 137 Cs uptake in plants was applied on data from artificially contaminated lysimeters. The lysimeter data involve three different crops (beans, ryegrass and lettuce) grown on five different soils between 3 and 5 years after contamination and where soil solution composition was monitored. The mechanistic model predicts plant uptake of 137 Cs from soil solution composition. Predicted K concentrations in the rhizosphere were up to 50-fold below that in the bulk soil solution whereas corresponding 137 Cs concentration gradients were always less pronounced. Predictions of crop 137 Cs content based on rhizosphere soil solution compositions were generally closer to observations than those based on bulk soil solution composition. The model explained 17% (beans) to 91% (lettuce) of the variation in 137 Cs activity concentrations in the plants. The model failed to predict the 137 Cs activity concentration in ryegrass where uptake of the 5-year-old 137 Cs from 3 soils was about 40-fold larger than predicted. The model generally underpredicted crop 137 Cs concentrations at soil solution K concentration below about 1.0 mM. It is concluded that 137 Cs uptake can be predicted from the soil solution composition at adequate K nutrition but that significant uncertainties remain when soil solution K is below 1 mM

  4. In vitro evaluation of {sup 213}Bi-rituximab versus external gamma irradiation for the treatment of B-CLL patients: relative biological efficacy with respect to apoptosis induction and chromosomal damage

    Energy Technology Data Exchange (ETDEWEB)

    Vandenbulcke, Katia; Lahorte, Christophe; Slegers, Guido [Department of Radiopharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, 9000, Gent (Belgium); De Vos, Filip; Dierckx, Rudi A. [Division of Nuclear Medicine, Ghent University Hospital (Belgium); Offner, Fritz [Department of Hematology, Ghent University Hospital (Belgium); Philippe, Jan [Department of Clinical Chemistry, Ghent University Hospital (Belgium); Apostolidis, Christos; Molinet, Roger; Nikula, Tuomo K. [European Commission, Joint Research Centre, Institute for Transuranium Elements, Karlsruhe (Germany); Bacher, Klaus; De Gelder, Virginie; Vral, Anne; Thierens, Hubert [Department of Anatomy, Embryology, Histology and Medical Physics, Ghent University (Belgium)

    2003-10-01

    External source radiotherapy and beta radioimmunotherapy (RIT) are effective treatments for lymphoid malignancies. The development of RIT with alpha emitters is attractive because of the high linear energy transfer (LET) and short path length, allowing higher tumour cell kill and lower toxicity to healthy tissues. We assessed the relative biological efficacy (RBE) of alpha RIT (in vitro) compared to external gamma irradiation with respect to induction of apoptosis in B chronic lymphocytic leukaemia (B-CLL) and induction of chromosomal damage in healthy donor B and T lymphocytes. The latter was measured by a micronucleus assay. {sup 213}Bi was eluted from a {sup 225}Ac generator and conjugated to CD20 antibody (rituximab) with CHX-A''-DTPA as a chelator. B-CLL cells from five patients were cultured for 24 h in RPMI/10% FCS while exposed to {sup 213}Bi conjugated to CD20 antibody or after external {sup 60}Co gamma irradiation. Binding assays were performed in samples of all patients to calculate the total absorbed dose. Apoptosis was scored by flow cytometric analyses of the cells stained with annexin V-FITC and 7-AAD. Apoptosis was expressed as % excess over spontaneous apoptosis in control. Full dose range experiments demonstrated {sup 213}Bi-conjugated CD20 antibody to be more effective than equivalent doses of external gamma irradiation, but showed that similar plateau values were reached at 10 Gy. The RBE for induction of apoptosis in B-CLL was 2 between 1.5 and 7 Gy. The micronucleus yield in lymphocytes of healthy volunteers was measured to assess the late toxicity caused by induction of chromosomal instability. While gamma radiation induced a steady increase in micronucleus yields in B and T cells, the damage induced by {sup 213}Bi was more dramatic, with RBE ranging from 5 to 2 between 0.1 Gy and 2 Gy respectively. In contrast to gamma irradiation, {sup 213}Bi inhibited mitogen-stimulated mitosis almost completely at 2 Gy. In conclusion, high

  5. A homeostatic-partly dynamic model for Cs-137 in trees

    International Nuclear Information System (INIS)

    Frissel, M. J.

    1994-01-01

    To describe the uptake of Cs-137 (hereafter only called Cs) two types of models seem most promising: the simple concentration ratio model and the homeostatic model. The first one calculates the concentration of Cs in the vegetation from the Cs concentration in the soil by applying a multiplication factor which is often called a transfer factor. There is no dynamics in the system, the transfer factor or concentration ratio is a constant, which may depend on the ecological system under study. It is often applied to annual crops. The second type of model assumes that the Cs/K ratio in the soil determines the Cs/K ratio in the vegetation. Also this model is usually static. By taking into account variations of the Cs/K ratio in the soil with time - e.g. as caused by K fertilization - it can be extended into a dynamic model. (author)

  6. Layer structured bismuth selenides Bi2Se3 and Bi3Se4 for high energy and flexible all-solid-state micro-supercapacitors

    Science.gov (United States)

    Hao, Chunxue; Wang, Lidan; Wen, Fusheng; Xiang, Jianyong; Li, Lei; Hu, Wentao; Liu, Zhongyuan

    2018-02-01

    In this work, bismuth selenides (Bi2Se3 and Bi3Se4), both of which have a layered rhombohedral crystal structure, have been found to be useful as electrode materials for supercapacitor applications. In a liquid electrolyte system (6M KOH), Bi2Se3 nanoplates exhibit much better performance as an electrode material than Bi3Se4 nanoparticles do, delivering a higher specific capacitance (272.9 F g-1) than that of Bi3Se4 (193.6 F g-1) at 5 mV s-1. This result may be attributed to the fact that Bi2Se3 nanoplates possess more active electrochemical surfaces for the reversible surface redox reactions owing to their planar quintuple stacked layers (septuple layers for Bi3Se4). To meet the demands of electronic skin, we used a novel flexible annular interdigital structure electrode to support the all-solid-state micro-supercapacitors (AMSCs). The Bi2Se3 AMSC device delivers a much better supercapacitor performance, exhibits a large stack capacitance of 89.5 F cm-3 at 20 mV s-1 (Bi3Se4: 79.1 F cm-3), a high energy density of 17.9 mWh cm-3 and a high power density of 18.9 W cm-3. The bismuth selenides also exhibit good cycle stability, with 95.5% retention after 1000 c for Bi2Se3 (Bi3Se4:90.3%). Clearly, Bi2Se3 nanoplates can be promising electrode materials for flexible annular interdigital AMSCs.

  7. How to train your T cell: genetically engineered chimeric antigen receptor T cells versus bispecific T-cell engagers to target CD19 in B acute lymphoblastic leukemia.

    Science.gov (United States)

    Ruella, Marco; Gill, Saar

    2015-06-01

    Antigen-specific T cell-based immunotherapy is getting its day in the sun. The contemporaneous development of two potent CD19-specific immunotherapeutic modalities for the treatment of B-cell malignancies provides exciting opportunities for patients, physicians and scientists alike. Patients with relapsed, refractory or poor-risk B-cell acute lymphoblastic leukemia (ALL) previously had few therapeutic options and now have two potential new lifelines. Physicians will have the choice between two powerful modalities and indeed could potentially enroll some patients on trials exploring both modalities if needed. For scientists interested in tumor immunology, the advent of chimeric antigen receptor T-cell therapy and of bispecific T-cell engagers (BiTEs) provides unprecedented opportunities to explore the promise and limitations of antigen-specific T-cell therapy in the context of human leukemia. In this article, we compare chimeric antigen receptor T cells and BiTEs targeting CD19 in B-cell ALL in the setting of the available clinical literature.

  8. Enhanced photosensitization process induced by the p–n junction of Bi2O2CO3/BiOCl heterojunctions on the degradation of rhodamine B

    International Nuclear Information System (INIS)

    Lu, Haijing; Xu, Lingling; Wei, Bo; Zhang, Mingyi; Gao, Hong; Sun, Wenjun

    2014-01-01

    Herein, we report the enhanced photosensitization process in the nanosheet Bi 2 O 2 CO 3 /BiOCl heterojunctions photocatalyst. The combined XRD, FT-IR and Raman results have confirmed the co-existence of Bi 2 O 2 CO 3 and BiOCl phases in the composites. Although both Bi 2 O 2 CO 3 and BiOCl are wide bandgap semiconductors, the composites showed an unexpectedly high catalytic activity in decomposing RhB (rhodamine B) aqueous solution under visible light irradiation. The mechanism of enhanced photocatalytic activity was ascribed to the inner electric field formed in the Bi 2 O 2 CO 3 /BiOCl p–n junction.

  9. Determination of normal expression patterns of CD86, CD210a, CD261, CD262, CD264, CD358, and CD361 in peripheral blood and bone marrow cells by flow cytometry.

    Science.gov (United States)

    Rudolf-Oliveira, Renata Cristina Messores; Auat, Mariangeles; Cardoso, Chandra Chiappin; Santos-Pirath, Iris Mattos; Lange, Barbara Gil; Pires-Silva, Jéssica; Moraes, Ana Carolina Rabello de; Dametto, Gisele Cristina; Pirolli, Mayara Marin; Colombo, Maria Daniela Holthausen Périco; Santos-Silva, Maria Claudia

    2018-02-01

    In 2010, new monoclonal antibodies were submitted to the 9th International Workshop on Human Leukocyte Differentiation Antigens, and there are few studies demonstrating normal expression patterns of these markers. Thus, the objective of this study was to determine the normal patterns of cell expression of CD86, CD210a, CD261, CD262, CD264, CD358, and CD361 in peripheral blood (PB) and bone marrow (BM) samples by flow cytometry. In the present study, CD86 was expressed only in monocytes and B lymphocytes in PB and in monocytes and plasma cells in BM. Regarding CD210a expression, in PB samples, monocytes and NK cells showed weak expression, while neutrophils, B and T lymphocytes, and basophils showed weak and partial expression. In BM samples, expression of CD210a was observed in eosinophils, monocytes, and B and T/NK lymphocytes. Weak expression of CD210a was also observed in neutrophilic cells and plasma cells. All B cell maturation stages had weak expression of CD210a except for immature B cells, which did not express this marker. In the present study, no cell type in PB samples showed positivity for CD261 and, in BM samples, there was very weak expression in neutrophilic series, monocytes, and B lymphocytes. Conversely, plasma cells showed positivity for CD261 with a homogeneous expression. For CD262, there was weak expression in monocytes, neutrophils, and B lymphocytes in PB samples and weak expression in monocytes, B lymphocytes, and plasma cells in BM samples. The evaluation of CD264 showed very weak expression in B cells in PB samples and no expression in BM cells. Very weak expression of CD358 was observed in neutrophils, monocytes, and B lymphocytes in PB and BM samples. In addition, in BM samples, plasma cells and T lymphocytes showed weak expression of CD358. In relation to the maturation stages of B cells, there was weak expression in pro-B cel, pre-B cell, and mature B cell. In the present study, it was possible to observe expression of CD361 in all

  10. High-temperature abnormal behavior of resistivities for Bi-In melts

    International Nuclear Information System (INIS)

    Xi Yun; Zu Fangqiu; Li Xianfen; Yu Jin; Liu Lanjun; Li Qiang; Chen Zhihao

    2004-01-01

    The patterns of electrical resistivities versus temperature in large temperature range have been studied, using the D.C. four-probe method, for liquid Bi-In alloys (Bi-In(33 wt%), Bi-In(38 wt%), Bi-In(50.5 wt%), Bi-In(66 wt%)). The clear turning point of each resistivity-temperature curves of the liquid Bi-In alloys is observed at the temperature much above the melting point, in which temperature range the resistivity-temperature coefficient increases rapidly. Except for the turning temperature range, the resistivities of Bi-In alloys increase linearly with temperature. Because resistivity is sensitive to the structure, this experiment shows the structural transition in Bi-In melts at the temperature much higher than the liquidus. And it is suggested that there are different Bi-In short-range orderings in different Bi-In melts, so the resistivity-temperature curves have the turns at different temperatures and the resistivity-temperature coefficients are also different

  11. High-pressure studies of superconductivity in BiO0. 75F0. 25BiS2

    Indian Academy of Sciences (India)

    ). We have investigated the effect of pressure on magnetization measurements. Our studies suggest improved superconducting properties in polycrystalline samples of BiO 0.75 F 0.25 BiS 2 . The Tc in our sample is 5.3 K, at ambient pressure, ...

  12. Potential barrier behavior in BiCuVOX materials Comportamento da barreira de potencial em materiais BiCuVOX

    Directory of Open Access Journals (Sweden)

    S. M. Gheno

    2011-12-01

    Full Text Available The BiMeVOX materials appear being high attractive for applications at low temperatures when the ionic conductivity is the determining parameter. The occurrence of many types substitution was confirmed for numerous Me ions, but the greatest interest have been focused on the BiCuVOX materials. The objective of this study was to image the potential barriers in BiCuVOX. The sample was sintered for 4 h at 750 °C and the results show that the high density compound can be obtained. Simultaneously, topography and electric force microscopy (EFM images are viewed side-by-side. EFM experiments were performed and the results show the maps of the electric field distribution on the surface of BiCuVOX. The formation of potential barrier was observed and the width and intensity were measured.Materiais do tipo BiMeVOX são muito atrativos para aplicações em baixas temperaturas quando a condutividade iônica for o parâmetro determinante. A ocorrência de muitos tipos de substituições foi confirmada para numerosos íons Me, dentre os quais, existe um grande interesse no estudo de materiais BiCuVOX. O objetivo deste estudo foi realizar o imageamento das barreiras de potencial em uma amostra de material BiCuVOX. A amostra foi sinterizada 4 h a 750 °C e apresentou alta densidade. Imagens da superfície topográfica e de microscopia de força elétrica (EFM foram obtidas simultaneamente em um microscópio de varredura por sonda. Os experimentos EFM mostraram um mapa da distribuição do campo elétrico na superfície do material BiCuVOx. A formação da barreira de potencial foi observada e tanto a largura quanto a altura foram medidas.

  13. Gd-substituted Bi-2223 superconductor

    Indian Academy of Sciences (India)

    The effects of gadolinium doping at calcium site on the normal and super- conducting properties of Bi-2223 system were ... quantities of the metal oxides and the carbonates were taken and thoroughly mixed. The calcination of the mixture after .... Therefore, Gd has higher solubility in (BiPb)-2223 as compared to Pr, and is, ...

  14. Impact of Diverse Immune Evasion Mechanisms of Cancer Cells on T Cells Engaged by EpCAM/CD3-Bispecific Antibody Construct AMG 110.

    Directory of Open Access Journals (Sweden)

    Wibke Deisting

    Full Text Available Bispecific T cell engager (BiTE® are single-chain bispecific antibody constructs with dual specificity for CD3 on T cells and a surface antigen on target cells. They can elicit a polyclonal cytotoxic T cell response that is not restricted by T cell receptor (TCR specificity, and surface expression of MHC class I/peptide antigen complexes. Using human EpCAM/CD3-bispecific BiTE® antibody construct AMG 110, we here assessed to what extent surface expression of PD-L1, cytoplasmic expression of indoleamine-2,3-deoxygenase type 1, Bcl-2 and serpin PI-9, and the presence of transforming growth factor beta (TGF-β, interleukin-10 (IL-10 and adenosine in culture medium can impact redirected lysis by AMG 110-engaged T cells.The seven factors, which are all involved in inhibiting T cell functions by cancer cells, were tested with human EpCAM-expressing Chinese hamster ovary (CHO target cells at levels that in most cases exceeded those observed in a number of human cancer cell lines. Co-culture experiments were used to determine the impact of the evasion mechanisms on EC50 values and amplitude of redirected lysis by AMG 110, and on BiTE®-induced proliferation of previously resting human peripheral T cells.An inhibitory effect on redirected lysis by AMG 110-engaged T cells was seen upon overexpression of serpin PI-9, Bcl-2, TGF-β and PD-L1. An inhibitory effect on induction of T cell proliferation was only seen with CHO cells overexpressing IDO. In no case, a single evasion mechanism rendered target cells completely resistant to BiTE®-induced lysis, and even various combinations could not.Our data suggest that diverse mechanisms employed by cancer cells to fend off T cells cannot inactivate AMG 110-engaged T cells, and that inhibitory effects observed in vitro may be overcome by increased concentrations of the BiTE® antibody construct.

  15. Impact of Diverse Immune Evasion Mechanisms of Cancer Cells on T Cells Engaged by EpCAM/CD3-Bispecific Antibody Construct AMG 110

    Science.gov (United States)

    Deisting, Wibke; Raum, Tobias; Kufer, Peter; Baeuerle, Patrick A.; Münz, Markus

    2015-01-01

    Background Bispecific T cell engager (BiTE®) are single-chain bispecific antibody constructs with dual specificity for CD3 on T cells and a surface antigen on target cells. They can elicit a polyclonal cytotoxic T cell response that is not restricted by T cell receptor (TCR) specificity, and surface expression of MHC class I/peptide antigen complexes. Using human EpCAM/CD3-bispecific BiTE® antibody construct AMG 110, we here assessed to what extent surface expression of PD-L1, cytoplasmic expression of indoleamine-2,3-deoxygenase type 1, Bcl-2 and serpin PI-9, and the presence of transforming growth factor beta (TGF-β), interleukin-10 (IL-10) and adenosine in culture medium can impact redirected lysis by AMG 110-engaged T cells. Methods The seven factors, which are all involved in inhibiting T cell functions by cancer cells, were tested with human EpCAM-expressing Chinese hamster ovary (CHO) target cells at levels that in most cases exceeded those observed in a number of human cancer cell lines. Co-culture experiments were used to determine the impact of the evasion mechanisms on EC50 values and amplitude of redirected lysis by AMG 110, and on BiTE®-induced proliferation of previously resting human peripheral T cells. Findings An inhibitory effect on redirected lysis by AMG 110-engaged T cells was seen upon overexpression of serpin PI-9, Bcl-2, TGF-βand PD-L1. An inhibitory effect on induction of T cell proliferation was only seen with CHO cells overexpressing IDO. In no case, a single evasion mechanism rendered target cells completely resistant to BiTE®-induced lysis, and even various combinations could not. Conclusions Our data suggest that diverse mechanisms employed by cancer cells to fend off T cells cannot inactivate AMG 110-engaged T cells, and that inhibitory effects observed in vitro may be overcome by increased concentrations of the BiTE® antibody construct. PMID:26510188

  16. Distribution of 137Cs in the American Coot (Fulica americana)

    International Nuclear Information System (INIS)

    Potter, C.M.; Brisbin, I.L. Jr.; McDowell, S.G.; Whicker, F.W.

    1989-01-01

    Caesium-137 concentrations were determined for major tissue and organ components of Americal Coots (Fulica americana) wintering on two contaminated reactor cooling reservoirs on the US Department of Energy's Savannah River Plant. Concentrations reflected the relative contamination levels of the two reservoirs. A low ratio of 137 Cs in gut contents to that in muscle indicated that the coots used in the study were established winter residents and tissue 137 Cs had probably reached equilibrium with intake. The contributions of each component to the whole body weight and total 137 Cs body burden were calculated. Skeletal muscle exhibited the highest 137 Cs concentrations and comprised 35% of the total 137 Cs body burden. Gut contents represented 17% of the total body burden. Various other organs were intermediate and bone exhibited the lowest 137 Cs concentrations. Linear regressions were determined for 137 Cs concentrations in skeletal muscle, liver, kidney, gastrointestinal (GI) tract tissue and gut contents, as functions of whole-body concentrations. (author)

  17. Chondroitin Sulfate (CS) Lyases: Structure, Function and Application in Therapeutics.

    Science.gov (United States)

    Rani, Aruna; Patel, Seema; Goyal, Arun

    2018-01-01

    Glycosaminoglycans (GAGs) such as chondroitin sulfate (CS) are the chief natural polysaccharides which reside in biological tissues mainly in extracellular matrix. These CS along with adhesion molecules and growth factors are involved in central nervous system (CNS) development, cell progression and pathogenesis. The chondroitin lyases are the enzyme that degrade and alter the CS chains and hence modify various signalling pathways involving CS chains. These CS lyases are substrate specific, can precisely manipulate the CS polysaccharides and have various biotechnological, medical and therapeutic applications. These enzymes can be used to produce the unsaturated oligosaccharides, which have immune-modulatory, anti-inflammatory and neuroprotective properties. This review focuses on the major breakthrough of the chondroitin sulfate degrading enzymes, their structures and functioning mechanism. This also provides comprehensive information regarding production, purification, characterization of CS lyases and their major applications, both established as well as emerging ones such as neural development. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  18. Bi[NC5H3(CO2)2](OH2)xF (x=1 and 2): New one-dimensional Bi-coordination materials—Reversible hydration and topotactic decomposition to α-Bi2O3

    Science.gov (United States)

    Jeon, Hye Rim; Lee, Dong Woo; Ok, Kang Min

    2012-03-01

    Two one-dimensional bismuth-coordination materials, Bi[NC5H3(CO2)2](OH2)xF (x=1 and 2), have been synthesized by hydrothermal reactions using Bi2O3, 2,6-NC5H3(CO2H)2, HF, and water at 180 °C. Structures of the two materials were determined by single-crystal X-ray diffraction. Although they have different crystal structures, both Bi-organic materials shared a common structural motif, a one-dimensional chain structure consisting of Bi3+ cations and pyridine dicarboxylate linkers. Detailed structural analyses include infrared spectroscopy, thermogravimetric analysis, and reversible hydration reactions for the coordinated water molecules were reported. Also, thermal decomposition of the rod-shaped Bi[NC5H3(CO2)2](OH2)F single crystals at 800 °C led to α-Bi2O3 that maintained the same morphology of the original crystals.

  19. The highly enhanced visible light photocatalytic degradation of gaseous o-dichlorobenzene through fabricating like-flowers BiPO{sub 4}/BiOBr p-n heterojunction composites

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Xuejun [Department of Environmental Science and Technology, Dalian Nationalities University, Dalian, 116600 (China); Dong, Yuying, E-mail: dongy@dlnu.edu.cn [Department of Environmental Science and Technology, Dalian Nationalities University, Dalian, 116600 (China); Zhang, Xiaodong, E-mail: fatzhxd@126.com [Environment and Low-Carbon Research Center, School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093 (China); Cui, Yubo; Ou, Xiaoxia [Department of Environmental Science and Technology, Dalian Nationalities University, Dalian, 116600 (China); Qi, Xiaohui [College of Life Science, Dalian Nationalities University, Dalian, 116600 (China)

    2017-01-01

    Highlights: • Like-flowers BiPO{sub 4}/BiOBr was fabricated by mixing in solvent method. • o-Dichlorobenzene removal efficiency was 53.6% using BiPO{sub 4}/BiOBr. • The p–n junction improved o-dichlorobenzene degradation activity. - Abstract: In this paper, in order to enhance photo-induced electron-hole pairs separation of BiOBr, flowers-like BiPO{sub 4}/BiOBr p-n heterojunction composites was fabricated by a mixing in solvent method. The as-prepared samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), UV–vis absorption spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and N{sub 2} adsorption-desorption. Meanwhile, their photocatalytic properties were investigated by the degradation of gaseous o-dichlorobenzene under visible light irradiation. Due to its strong adsorption capacity and the formation of p-n heterojunction, compared with BiPO{sub 4} and BiOBr, the BiPO{sub 4}/BiOBr composites showed higher photocatalytic activity in the degradation of gaseous o-DCB under visible light. Among them, 2% BiPO{sub 4}/BiOBr showed the maximum value of the activity, whose degradation rate was about 2.6 times as great as the pure BiOBr. Furthermore, the OH· was confirmed the main active species during the photocatalytic process by the trapping experiments. The outstanding performance indicated that the photocatalysts could be applied to air purification for chlorinated volatile organic compound.

  20. Proteoglycan from salmon nasal cartridge promotes in vitro wound healing of fibroblast monolayers via the CD44 receptor

    International Nuclear Information System (INIS)

    Ito, Gen; Kobayashi, Takeshi; Takeda, Yoshie; Sokabe, Masahiro

    2015-01-01

    Highlights: • Proteoglycan from salmon nasal cartridge (SNC-PG) promoted wound healing in fibroblast monolayers. • SNC-PG stimulated both cell proliferation and cell migration. • Interaction between chondroitin sulfate-units and CD44 is responsible for the effect. - Abstract: Proteoglycans (PGs) are involved in various cellular functions including cell growth, adhesion, and differentiation; however, their physiological roles are not fully understood. In this study, we examined the effect of PG purified from salmon nasal cartilage (SNC-PG) on wound closure using tissue-cultured cell monolayers, an in vitro wound-healing assay. The results indicated that SNC-PG significantly promoted wound closure in NIH/3T3 cell monolayers by stimulating both cell proliferation and cell migration. SNC-PG was effective in concentrations from 0.1 to 10 μg/ml, but showed much less effect at higher concentrations (100–1000 μg/ml). The effect of SNC-PG was abolished by chondroitinase ABC, indicating that chondroitin sulfates (CSs), a major component of glycosaminoglycans (GAGs) in SNC-PG, are crucial for the SNC-PG effect. Furthermore, chondroitin 6-sulfate (C-6-S), a major CS of SNC-PG GAGs, could partially reproduce the SNC-PG effect and partially inhibit the binding of SNC-PG to cells, suggesting that SNC-PG exerts its effect through an interaction between the GAGs in SNC-PG and the cell surface. Neutralization by anti-CD44 antibodies or CD44 knockdown abolished SNC-PG binding to the cells and the SNC-PG effect on wound closure. These results suggest that interactions between CS-rich GAG-chains of SNC-PG and CD44 on the cell surface are responsible for the SNC-PG effect on wound closure