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Sample records for zhidkostej po stekhiometricheskoj

  1. Role of PO4 tetrahedron in LiFePO4 and FePO4 system.

    Science.gov (United States)

    Zeng, Yuewu

    2015-06-01

    Using high resolution transmission electron microscopy with image simulation and Fourier analysis, the Li1- x FePO4 (x < 0.01), Li1- x FePO4 (x ∼ 0.5), and FePO4 particles, prepared by charging or discharging the 053048 electrochemical cells (thickness: 5 mm, width: 30 mm, height: 48 mm) and dismantled inside an Ar-filled dry box, were investigated. The high resolution images reveal: (1) the solid solution of Li1- x FePO4 (x < 0.01) contains some missing Li ions leading PO4 group distorted around M1 tunnel of the unit cell; (2) the texture of the particles of Li1- x FePO4 (x ∼0.5) has homogeneously distributed compositional domains of LiFePO4 and FePO4 resulting from spinodal decomposition which promote Li ion easily getting into the particle due to uphill diffusion, (3) the particles of FePO4 formed in charging have heavily distorted lattice and contain some isolated LiFePO4 , (4) interface between LiFePO4 and FePO4 and between amorphous and crystal region provides the lattice distortion of small polarons. © 2015 Wiley Periodicals, Inc.

  2. Systems of Ba(PO3)2-Sr(Pu3)2, Cd(PO3)2-Ca(PO3)2

    International Nuclear Information System (INIS)

    Tokman, I.A.; Bukhalova, G.A.

    1977-01-01

    Phase diagrams of the Ba(PO 3 ) 2 -Sr(PO 3 ) 2 and Cd(PO 3 ) 2 -Ca(PO 3 ) 2 systems have been studied and plotted by the methods of differential-thermal analysis (DTA), visual-polythermal, X-ray phase and infrared spectroscopy. The Ba(PO 3 ) 2 -Sr(PO 3 ) 2 system is of the eutectic type. In the binary system Cd(PO 3 ) 2 -Ca(PO 3 ) 2 the existence of a continuous series of solid solutions with a minimum at 858 deg C and 27.5 mol.% Ca(PO 3 ) 2 has been established

  3. Metabolism of 210Po in rats: Volatile 210Po from faeces

    International Nuclear Information System (INIS)

    Sadi, B. B.; Li, C.; Wyatt, H.; Bugden, M.; Wilkinson, D.; Kramer, G.

    2011-01-01

    The metabolic formation of volatile 210 Po species in a rat that was intravenously administered with 210 Po-citrate was investigated in this study. A slurry of the faecal sample was prepared in water and was bubbled with nitrogen gas in a closed system. The discharged gas was passed through a trapping device filled with liquid scintillation cocktail in order to capture any volatile 210 Po species. The amount of 210 Po trapped in the scintillation cocktail was measured by a liquid scintillation analyser that provided evidence of the presence of volatile 210 Po species in the faeces. The presence of volatile 210 Po in the faeces indicates that the metabolic formation of volatile 210 Po is likely to occur in the gut due to bacterial activity. The amount of volatile 210 Po species was compared with the daily faecal excretion of 210 Po. After 2 h of bubbling, the volatile 210 Po collected from the faeces sample was found to be between 1.0 and 1.7 % of the daily faecal excretion for the 4 d following 210 Po-citrate administration. (authors)

  4. Complex phosphates in the Li(Na)3PO4-InPO4 systems

    International Nuclear Information System (INIS)

    Potapova, A.M.; Zimina, G.V.; Smirnova, I.N.; Novoselov, A.V.; Spiridonov, F.M.; Stefanovich, S.Yu.

    2008-01-01

    Subsolidus sections in the systems Li 3 PO 4 -InPO 4 (950 deg C) and Na 3 PO 4 -InPO 4 (800, 900, and 1000 deg C) have been studied by X-ray powder diffraction. The compound Li 3 In(PO 4 ) 2 has been synthesized, and the NASICON-type solid solution Li 3(1-x) In 2+x (PO 4 ) 3 (0.67 ≤ x ≤ 0.80) has been found to exist. In the system Na 3 PO 4 -InPO 4 , the solid solution Na 3(1-x) In x/3 PO 4 (0 ≤ x ≤ 0.2) and two complex phosphates exist: Na 3 In(PO 4 ) 2 and Na 3 In 2 (PO 4 ) 3 . These complex phosphates are dimorphic, with the irreversible-transition temperature equal to 675 and 820 deg C, respectively. Na 3 In(PO 4 ) 2 degrades at 920 deg C. Ionic conductivity has been measured in some phases in the system [ru

  5. The Ca(PO3)2-Sr(PO3)2 system

    International Nuclear Information System (INIS)

    Bukhalova, G.A.; Tokman, I.A.

    1977-01-01

    Phase diagram of the system Ca(PO 3 ) 2 -Sr(PO 3 ) 2 has been studied and plotted with the aid of differential thermal, visual polythermal, X-ray analysis, and infrared spectroscopy. Continuous solid solutions are formed in the system with a minimum at 968 deg C and 25 mol.% of Sr(PO 3 ) 2 . Solid solutions decompose with the formation of about 30 mol.% of Sr(PO 3 ) 2

  6. In-beam spectroscopy of 198Po and 200Po nuclei

    International Nuclear Information System (INIS)

    Maj, A.

    1988-01-01

    The main purpose of this thesis is to answer the question whether any signs of collectivity or deformation are evident in 198 Po and 200 Po nuclei, situated on the border of the predicted new region of oblate deformation. Bearing this in mind spectroscopic investigations were performed. The level schemes of 198 Po and 200 Po were established, transition rates were determined and g-factors of isomeric states and, for 200 Po, the quadrupole moment of the 8 + - state were measured. The experimental techniques are described and the methods of evaluating the obtained data are presented. 74 refs., 7 figs., 9 tabs. (M.F.W.)

  7. Crystal structures of Th(OH)PO4, U(OH)PO4 and Th2O(PO4)2. Condensation mechanism of M(IV)(OH)PO4 (M= Th, U) into M2O(PO4)2

    International Nuclear Information System (INIS)

    Dacheux, N.; Clavier, N.; Wallez, G.; Quarton, M.

    2007-01-01

    Three new crystal structures, isotypic with β-Zr 2 O(PO 4 ) 2 , have been resolved by the Rietveld method. All crystallize with an orthorhombic cell (S.G.: Cmca) with a = 7.1393(2) Angstroms, b = 9.2641(2) Angstroms, c 12.5262(4) Angstroms, V = 828.46(4) (Angstroms) 3 and Z = 8 for Th(OH)PO 4 ; a = 7.0100(2) Angstroms, b = 9.1200(2) Angstroms, c = 12.3665(3) Angstroms, V 790.60(4) (Angstroms) 3 and Z = 8 for U(OH)PO 4 ; a 7.1691(3) Angstroms, b 9.2388(4) Angstroms, c = 12.8204(7) Angstroms, V 849.15(7) (Angstroms) 3 and Z = 4 for Th 2 O(PO 4 ) 2 . By heating, the M(OH)PO 4 (M Th, U) compounds condense topotactically into M 2 O(PO 4 ) 2 , with a change of the environment of the tetravalent cation that lowers from 8 to 7 oxygen atoms. The lower stability of Th 2 O(PO 4 ) 2 compared to that of U 2 O(PO 4 ) 2 seems to result from this unusual environment for tetravalent thorium. (authors)

  8. On thermal expansion of RbD2PO4, CsH2PO4 and CsDrPO4 crystals

    International Nuclear Information System (INIS)

    Vlokh, O.G.; Shchur, Ya.I.; Klymiv, I.M.

    1994-01-01

    Thermal expansion of RbD 2 PO 4 , CsH 2 PO 4 , CsD 2 PO 4 crystals in a wide range of temperatures embracing points of phase transitions was studied. An explanation of anomalous behaviour of thermal expansion factor along directions b and c in the course of RbD 2 PO 4 transfer into intermediate phase was suggested. 10 refs., 4 figs

  9. Crystal structure of 4-RbHo(PO3)4, 4-RbTm(PO3)4 and 4-CsEr(PO3)4

    International Nuclear Information System (INIS)

    Maksimova, S.I.; Palkina, K.K.; Chibiskova, N.T.

    1982-01-01

    X-ray structural study of 4-RbLn(PO 3 ) 4 (Ln=Mo, Tm) and 4-CsEr(PO 3 ) 4 is carried out. The compounds are crystallized in monoclinic crystal system, sp. gr P2 1 /n. Parameters of their unit cell, atom coordinates, anisotropic heat parameters, interatomic distances and valent angles are given. 4-RbHo(PO 3 ) 4 , 4-RbTm(PO 3 ) 4 , 4-CsEr(PO 3 ) 4 are isostructural to previously studied TlNd(PO 3 ) and 4-RbNd(PO 3 ) 4 . Using as an example the structural type 4-M 1 Ln(PO 3 ) 4 it is shown that the change of the shortest distances Ln-Ln, M 1 -M 1 and M 1 -Ln, as well as of degree of polymorphous chain corrugation to a higher extent depends on rare earth atom dimensions, than on monovalent metal ion dimensions [ru

  10. The system La(PO3)3-Ca(PO3)2-P2O5

    International Nuclear Information System (INIS)

    Jungowska, W.; Znamierowska, T.

    1993-01-01

    Ternary system La(PO 3 ) 3 -Ca(PO 3 ) 2 -P 2 O 5 has been studied by means of thermal and roentgenography analysis. The existence of single intermediate compound CaLa(PO 3 ) 5 has been observed. The phase diagrams for the ternary system as well as for two binary systems La(PO 3 ) 3 -Ca(PO 3 ) 2 and CaLa(PO 3 ) 5 -LaP 5 O 11 have been shown. 7 refs, 3 figs

  11. Mixed phosphates of the Na3PO4 - LnPO4 systems

    International Nuclear Information System (INIS)

    Slivko, T.A.; Smirnova, I.N.; Zimina, G.V.; Spiridonov, F.M.; Chudinova, N.N.

    2002-01-01

    The phase relationships in the systems Na 3 PO 4 - LnPO 4 (subsolidus 950 Deg C cross-sections), where Ln=Sm, Eu, Tb, Dy, Ho, Tm, Yb, Lu, were studied by X-ray analysis. Reactions of the components were deduced, formed phases were separated and identified. The Na 6 Ln 3 (PO 4 ) 5 (Ln=Dy, Ho, Tm), Na 3 Ln 2 (PO 4 ) 3 (Ln=Tm, Yb, Lu) compounds and phases of the unstable composition Na 6+x Ln 3-x/3 (PO 4 ) 5 (Ln=Yb, Lu, 0 ≤ x ≤ 1.5) were detected for the first time. In all systems the existence of the Na 3-x Ln x/3 PO 4 unstable composition phase on the basis of the high temperature modification of sodium phosphate (sp. gr. Fm3m) is established, suggesting that stabilization of this modification by rare earth ions is possible [ru

  12. Electronic Properties of LiFePO4 and Li doped LiFePO4

    International Nuclear Information System (INIS)

    Zhuang, G.V.; Allen, J.L.; Ross, P.N.; Guo, J.-H.; Jow, T.R.

    2005-01-01

    The potential use of different iron phosphates as cathode materials in lithium-ion batteries has recently been investigated.1 One of the promising candidates is LiFePO4. This compound has several advantages in comparison to the state-of-the-art cathode material in commercial rechargeable lithium batteries. Firstly, it has a high theoretical capacity (170 mAh/g). Secondly, it occurs as mineral triphylite in nature and is inexpensive, thermally stable, non-toxic and non-hygroscopic. However, its low electronic conductivity (∼10-9 S/cm) results in low power capability. There has been intense worldwide research activity to find methods to increase the electronic conductivity of LiFePO4, including supervalent ion doping,2 introducing non-carbonaceous network conduction3 and carbon coating, and the optimization of the carbon coating on LiFePO4 particle surfaces.4 Recently, the Li doped LiFePO4 (Li1+xFe1-xPO4) synthesized at ARL has yield electronic conductivity increase up to 106.5 We studied electronic structure of LiFePO4 and Li doped LiFePO4 by synchrotron based soft X-ray emission (XES) and X-ray absorption (XAS) spectroscopies. XAS probes the unoccupied partial density of states, while XES the occupied partial density of states. By combining XAS and XES measurements, we obtained information on band gap and orbital character of both LiFePO4 and Li doped LiFePO4. The occupied and unoccupied oxygen partial density of states (DOS) of LiFePO4 and 5 percent Li doped LiFePO4 are presented in Fig. 1. Our experimental results clearly indicate that LiFePO4 has wideband gap (∼ 4 eV). This value is much larger than what is predicted by DFT calculation. For 5 percent Li doped LiFePO4, a new doping state was created closer to the Fermi level, imparting p-type conductivity, consistent with thermopower measurement. Such observation substantiates the suggestion that high electronic conductivity in Li1.05Fe0.95 PO4 is due to available number of charge carriers in the material

  13. α-decay properties of 190Po and the identification of 191Po

    International Nuclear Information System (INIS)

    Batchelder, J.C.; Batchelder, J.C.; Zganjar, E.F.; Toth, K.S.; Bingham, C.R.; Bingham, C.R.; Wauters, J.; Brown, L.T.; Davids, C.N.; Seweryniak, D.; Brown, L.T.; Conticchio, L.F.; Seweryniak, D.; Conticchio, L.F.; Wood, J.L.

    1997-01-01

    The α-decay properties of 190 Po were investigated through the use of a fragment mass analyzer in conjunction with a double-sided Si strip detector. The isotope was produced via the 96 Mo( 96 Mo,2n) reaction, and its α-decay energy and T 1/2 were measured as 7529(10) keV and 2.4 -0.3 +0.4 ms, respectively. The resulting reduced width is nearly identical to that of the 192,194 Po isotopes. This is believed to result from significant mixing between the ground state π(2p) and the low-lying 0 + π(4p-2h) intruder state in the Po parent. The result provides further evidence for shape coexistence in the light Po isotopes. In addition, 191 Po was unambiguously identified, and the 186 Pb α-decay branch was determined experimentally for the first time. copyright 1997 The American Physical Society

  14. Le corps poétique ou la poétique du corps

    Directory of Open Access Journals (Sweden)

    Yvonne Goga

    2007-05-01

    Full Text Available Les réflexions sur la poésie de Valéry sont illustrées dans deux volumes : Album de vers anciens et Charmes. Parmi les images les plus représentatives est celle du corps de la femme. Par l’analyse des images sur le corps de la femme, le but de notre étude est celui de souligner l’un des principes de la poétique de Valéry : la relation entre le monde extérieur, le corps et l’esprit, pour créer le poème et le poète.

  15. Inelastic neutron scattering and lattice dynamics studies of AlPO4 and GaPO4

    International Nuclear Information System (INIS)

    Mittal, R.; Chaplot, S.L.; Kolesnikov, A.I.; Loong, C.-K.; Jayakumar, O.D.; Kulshreshtha, S.K.

    2006-01-01

    The compounds AlPO 4 and GaPO 4 show phase transitions at high pressure depending on the compressibility of the constituent tetrahedra. Semi-empirical interatomic potentials are available for AlPO 4 and GaPO 4 . Molecular dynamics simulations have been reported using these potentials to understand the nature of phase transitions in different polymorphs of these compounds. In order to check these potentials we have carried out lattice dynamical studies for AlPO 4 and GaPO 4 . The phonon density of states measurements from the polycrystalline samples of low-cristobalite phase of AlPO 4 and GaPO 4 are carried out using High-Resolution Medium-Energy Chopper Spectrometer at ANL in the energy transfer range 0-160 meV. The calculated phonon spectra for both the compounds using the available potentials show fair agreement with the experimental data. However, the agreement between the two is improved by including the polarizibility of the oxygen atoms in the framework of the shell model. The lattice dynamical model is used for the calculation of specific heat and thermal expansion

  16. Radiochemical determination of 210Po

    International Nuclear Information System (INIS)

    Clarence, J.

    1961-04-01

    By spontaneous deposition of Po onto silver, and with the use of Po 208 as a tracer, the accurate spectrographic measurements are made possible. Quantitative recovery of Po 210 from radioactive cellulose filters is obtained by burning of samples in a golden lined calorimetric bomb. (author) [fr

  17. Enhanced photo-stability and photocatalytic activity of Ag3PO4 via modification with BiPO4 and polypyrrole

    Science.gov (United States)

    Cai, Li; Jiang, Hui; Wang, Luxi

    2017-10-01

    Ag3PO4 photocatalysts modified with BiPO4 and polypyrrole (PPy) were successfully synthesized via a combination of co-precipitation hydrothermal technique and oxidative polymerization method. Their morphologies, structures and optical and electronic properties were characterized by means of scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscope (TEM), Brunauer-Emmett-Teller (BET) surface areas, X-ray diffraction (XRD), fourier transform infrared spectra (FT-IR), X-ray photo-electron spectroscopy (XPS), UV-vis diffuse reflection spectra (UV-vis DRS), photocurrent technique and electrochemical impedance spectra (EIS). The typical triphenylmethane dye (malachite green) was chosen as a target organic contaminants to estimate the photocatalytic activities and photo-stabilities of Ag3PO4-BiPO4-PPy heterostructures under visible light irradiation. The results indicated that the existence of BiPO4 and PPy not only showed great influences on the photocatalytic activity, but also significantly enhanced photo-stability of Ag3PO4 in repeated and long-term applications. The degradation conversion of Ag3PO4-BiPO4-PPy heterostructures (ABP-3) was 1.58 times of that of pure Ag3PO4. The photo-corrosion phenomenon of Ag3PO4 was effectively avoided. The photocatalytic activity of up to 87% in the Ag3PO4-BiPO4-PPy heterostructures (ABP-3) can be remained after five repeated cycles, while only about 33% of the degradation efficiency can be reserved in pure Ag3PO4. The possible mechanism of enhanced photo-stability and photocatalytic activity of Ag3PO4-BiPO4-PPy heterostructures was also discussed in this work.

  18. Mechanical and thermal-expansion characteristics of Ca10(PO46(OH2-Ca3(PO42 composites

    Directory of Open Access Journals (Sweden)

    Ruseska G.

    2006-01-01

    Full Text Available Three types of composites consisting of Ca10(PO46(OH2 and Ca3(PO42 with composition: 75% (wt Ca10(PO46(OH2: 25%(wt Ca3(PO42; 50%(wt Ca10(PO46(OH2: 50%(wtCa3(PO42 and 25 %(wt Ca10(PO46(OH2: 75%(wt Ca3(PO42 were the subject of our investigation. Sintered compacts were in thermal equilibrium, which was proved by the absence of hysteresis effect of the dependence ΔL/L=f(T during heating /cooling in the temperature interval 20-1000-200C. Sintered compacts with the previously mentioned composition possess 26-50% higher values of the E-modulus, G-modulus and K-modulus indicating the presence of a synergism effect. Several proposed model equations for predicting the thermal expansion coefficient in dependence of the thermal and elastic properties of the constitutive phases and their volume fractions, given by: Turner, Kerner, Tummala and Friedberg, Thomas and Taya, were used for making correlations between mechanical and thermal-expansion characteristics of the Ca10(PO46(OH2 - Ca3(PO42 composites. Application of the previously mentioned model equations to all kinds of composites leads to the conclusion that the experimentally obtained results for the thermal expansion coefficient are in an excellent agreement with the theoretical calculated values on account of the volume fraction of each constitutive phase and with all applied model equations, with a coefficient of correlation from 98.16-99.86 %.

  19. In vitro cell culture pO2 is significantly different from incubator pO2.

    Science.gov (United States)

    Bambrick, L L; Kostov, Y; Rao, G

    2011-07-01

    Continuous noninvasive monitoring of peri-cellular liquid phase pO2 in adherent cultures is described. For neurons and astrocytes, this approach demonstrates that there is a significant difference between predicted and observed liquid phase pO2. Particularly at low gas phase pO2s, cell metabolism shifts liquid phase pO2 significantly lower than would be predicted from the O2 gas/air equilibrium coefficient, indicating that the cellular oxygen uptake rate exceeds the oxygen diffusion rate. The results demonstrate the need for direct pO2 measurements at the peri-cellular level, and question the widely adopted current practice of relying on setting the incubator gas phase level as means of controlling pericellular oxygen tension, particularly in static culture systems that are oxygen mass transfer limited. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

  20. Luminescent properties of LuPO4-Pr and LuPO4-Eu nanoparticles

    International Nuclear Information System (INIS)

    Vistovskyy, V.; Malyi, T.; Vas’kiv, A.; Chylii, M.; Mitina, N.; Zaichenko, A.; Gektin, A.; Voloshinovskii, A.

    2016-01-01

    Spectral-luminescence parameters of LuPO 4 -Eu and LuPO 4 -Pr nanoparticles of different sizes are studied upon excitation by the synchrotron radiation with photon energies 4–40 eV. Influence of the nanoparticle size on Eu 3+ and Pr 3+ impurity luminescence is analyzed for intracenter and recombination excitation. It is shown that the luminescence intensity of impurities in the case of recombination excitation significantly stronger decreases with decreasing of nanoparticle size compared to intracenter excitation. This feature is explained by the influence of thermalization length to nanoparticle size ratio on the recombination luminescence. Electron recombination luminescence inherent for LuPO 4 -Eu nanoparticles shows a weaker dependence on the nanoparticle size than the hole one in LuPO 4 -Pr nanoparticles. The difference between energy states of praseodymium impurity ions in nanoparticles of different sizes is revealed.

  1. Kinetics of neutralization of Po-218

    International Nuclear Information System (INIS)

    Chu, K.D.

    1987-01-01

    In a well-defined experimental system the neutralization of polonium-218 ions was investigated as a function of the physical and chemical properties of the controlled composition atmosphere. The mobilities of Po + and PoO 2 + are determined by combining experimental results with a computer model of the system. Three neutralization mechanisms were individually studied. The small ion recombination rate has been found to be proportional to the square root of radon concentration. The electron scavenging mechanism is responsible for the neutralization of Po + in NO 2 or H 2 O in nitrogen. When PoO 2 + is formed, the electron transfer mechanism dominates the neutralization process. The electron is transferred to PoO 2 + from molecules with lower ionization potentials. The ionization potential of PoO 2 + is also determined to be 10.44 +/- 0.05 eV

  2. Crystal structure of polyphosphates NaCd(PO3)3 and NaMn(PO3)3

    International Nuclear Information System (INIS)

    Murashova, E.V.; Chudinova, N.N.

    1997-01-01

    Crystal structure of NaCd(PO 3 ) 3 (1) and NaMn(PO 3 ) 3 (2) isostructural polyphosphates was determined for twin samples. Rhombic lattice parameters of (1): a = 14.678, b = 14.669, c = 14.705 A, sp. gr. P2 1 2 1 2 1 , Z = 16. The structure of compounds is of frame type. Polyphosphate chain with repetition period of 24 PO 4 tetrahedrons contacts with NaO 6 and M 2 O 6 octahedrons by means of common oxygen vertices. Similarities and differences in structure of mentioned polyphosphates and earlier analyzed NaMg(PO 3 ) 3 polyphosphate are noted [ru

  3. Neutralization of Na2PO4: Reaction between Na3PO4 and CaCL2

    International Nuclear Information System (INIS)

    Xia Shenglan; Wang Luning

    1990-01-01

    The results of reaction Na 3 PO 4 with CaCl 2 in water at ambient and higher temperature are described. The reaction rate of Na 3 PO 4 with CaCl 2 is slow at ambient temperature and the reaction is complete at 260 deg C after 2 h. The products are Ca(OH) 2 and Ca 5 (PO 4 ) 3 (OH). The quantity of them is dependent upon the quanity of Na 3 PO 4 and CaCl 2 contained in water, all of them control pH of water

  4. pO2 measurements in arteriolar networks.

    Science.gov (United States)

    Torres Filho, I P; Kerger, H; Intaglietta, M

    1996-03-01

    Previous studies from our laboratory have shown that the average arteriolar pO2 in the hamster skinfold preparation is lower than arterial systemic pO2. In the present work we tested the hypothesis that there is a longitudinal gradient of pO2 along precapillary vessels. Experiments were performed in Syrian golden hamsters bearing a dorsal skin chamber. The oxygen-dependent quenching of phosphorescence of palladium-porphyrin complexes was used to measure intravascular pO2 in the microcirculation. Arterioles were classified in four orders according to their position in the network, first-order vessels being the entrance points. Simultaneous determinations of diameter (D), red blood cell velocity, and systemic blood gases were also made. There was a significant fall of pO2 between vessels of different orders. First-order arterioles (mean D = 64 microns) had pO2 of 51.8 +/- 9.8 mm Hg (mean +/- SD) which was equivalent to approximately equal to 73% of the arterial systemic pO2. Within the arteriolar network, further decreases of intravascular pO2 were measured, leading to a pO2 of 34.0 +/- 7.9 mm Hg in terminal arterioles (mean D = 7.7 microns). In some vessels pO2 was measured in different positions of the same arteriole. The average longitudinal arteriolar oxygen saturation gradient was 3.4 +/- 0.4 delta %/mm (range 0.8-7.2). A significant and positive correlation was found between pO2 and microhemodynamic parameters when arterioles were grouped according to their order. This relation was not significant for venules which showed a mean pO2 of 30.8 +/- 10.8 mm Hg. Tissue pO2 averaged 24.6 +/- 5.8 mm Hg. We conclude that: (1) There is an oxygen loss in arterial vessels larger than 100 micrograms in diameter, (2) arteriolar pO2 in this preparation depends on the position of the vessel within the network, (3) a substantial portion of oxygen delivery to the hamster skin is provided by the arteriolar network, and (4) only a small pO2 gradient exists between terminal

  5. Rhenium(V) and technetium(V) complexes of bis(o-hydroxyphenyl)phenylphosphine (PO22-) and (o-hydroxyphenyl)diphenylphosphine (PO-) ligands

    International Nuclear Information System (INIS)

    Luo, Hongyan; Setyawati, Ika; Rettig, S.J.; Orvig, C.

    1995-01-01

    The synthesis of several phosphine-based chelating compounds and chelates formed between these compounds and rhenium or technetium is discussed. Four categories of products result, (i) bis-(o-hydroxyphenyl) diphenylphosphine (PO) complexes, (ii) mono- (PO) complexes, (iii) bis-bis(o-hydroxyphenyl)-phenylphosphine (PO 2 ) complexes, and mixed-(PO) and (PO 2 ) complexes. Molecular structures of these compounds (including isomers) were probed by NMR, MS, and IR spectroscopies and by X-ray crystallography

  6. A simulation study on the topotactic transformations from aluminophosphate AlPO(4)-21 to AlPO(4)-25.

    Science.gov (United States)

    Li, J; Yu, J; Wang, K; Zhu, G; Xu, R

    2001-11-05

    Aluminophosphate AlPO(4)-21 (AWO), formulated /(CH(3))(2)NH(2)/[Al(3)P(3)O(12)(OH)], has been synthesized solvothermally by using dimethylamine as the template. Single-crystal X-ray diffraction analysis shows that AlPO(4)-21 crystallizes in the monoclinic space group P2(1)/n with a = 8.687(2) A, b = 17.428(5) A, c = 9.159(2) A, beta = 109.60(2) degrees, V = 1306.3(5) A(3), and Z = 4. XRD analysis shows that AlPO(4)-21 transforms to AlPO(4)-25 (ATV) upon calcination at 500 degrees C. The molecular dynamics simulation approach was used to investigate the topotactic transformations from AlPO(4)-21. The simulation study suggests that AlPO(4)-21 is energetically favored to transform to AlPO(4)-25, as well as other hypothetical forms, by the changing of the UUDD chains to the UDUD chains.

  7. Po2 temperature blood factor for blood gas apparatus.

    Science.gov (United States)

    Teisseire, B P; Hérigault, R A; Teisseire, L J; Laurent, D N

    1984-01-01

    PO2 temperature formulae supplied by manufacturers on automatic blood gas apparatus, PO2 corr. = PO2 37 degrees C X 10F X delta T were studied and compared to the experimental determination of the delta log PO2/delta T ratio (Hérigault et al. [10]). Acid-base status at 37 degrees C appeared to have a measurable influence on the PO2 temperature factor; alkalosis increased the delta log PO2/delta T ratio, and the contrary was found for acidosis in comparison with normal acid-base status at 37 degrees C. For the same PO2, measured at 37 degrees C, all the proposed formulae of commercial blood gas automatic apparatus did not give the same temperature corrected PO2. The observed difference between the corrected PO2 may be important and greater than the precision of the initial measurement. To correct the measured PO2 for temperature, a relationship between delta log PO2/delta T and PO2 is proposed, between PO2 zero and PO2 180 mmHg, which takes into account measured pH and PO2 values at 37 degrees C:delta log PO2/delta T = [(-0.35 pH + 0.658) X 10(-4) X PO2] + 0.035.

  8. Superacid univalent metal phosphites (MH2PO3)2·H3PO3 (M Rb, Tl+) and MH2PO3·H3PO3 (M = K, Cs): synthesis and structure

    International Nuclear Information System (INIS)

    Kosterina, E.V.; Troyanov, S.I.; Aslanov, L.A.; Kemnits, Eh.

    2001-01-01

    Crystal superacid phosphites α-CsH 2 PO 3 ·H 3 PO 3 (1) and β-CsH 2 PO 3 ·H 3 PO 3 (2) were prepared by means of interaction between cesium carbonate and phosphoric acid excess. The structure of the compounds, i.e.: 1-rhombic crystal system, sp.gr. P2 1 2 1 2 1 , a = 6.033 (1), b = 6.444 (1), c = 18.345 (4) A: 2-monoclinic crystal system, sp.gr. C2/c, a = 9.990 (3), b = 12.197 (4), c = 6.866 (2) A, β = 118.14 (3) deg, was determined by the method of X-ray diffraction analysis of monocrystals at 150 K. Comparative analysis of the crystal structure and hydrogen bond systems in acid phosphites of different composition was conducted [ru

  9. Synthesis and crystal structure of hydrogen phosphites RbH2PO3, CsH2PO3, and TlH2PO3

    International Nuclear Information System (INIS)

    Kosterina, E.V.; Troyanov, S.I.; Kemnits, Eh.; Aslanov, L.A.

    2001-01-01

    The crystal acid phosphites RbH 2 PO 3 , CsH 2 PO 3 and TlH 2 PO 3 were separated during reaction of Rb, Cs and Tl carbonates with phosphorous acid solution. The crystal structure of the compounds was analyzed by X-ray diffraction method at 150 K. CsH 2 PO 3 has a monoclinic system, a = 7.930(2), b = 8.929(2), c = 13.163(3) A, β = 104.84(3) Deg, V = 900.9(4) A 3 , Z 8, sp. gr. P2 1 /c, R 1 = 0.239. In the structure hydrogen bonds integrate the PHO 3 tetrahedrons in the unlimited zigzag chains [HPHO 3 ] n n- laying at the layers, which are alternate to the layers of metal cations. The layers of anion chains have a wavy form [ru

  10. Po-210 excretion and radon exposure

    International Nuclear Information System (INIS)

    Breuer, F.; Clemente, G.F.

    1979-01-01

    A mathematical model is given to describe the metabolism of the 210 Po introduced into the systemic compartiments of the human body. The model has been based on the experimental data referred to the 210 Pb- 210 Po intake, excretion and body burden of members of the general italian population. The model fits also very well the experimental data of 210 Pb- 210 Po intake and excretion reported by other authors. The retention function of 210 Po in total body, soft tissue and bone has been evaluated together with the urinary excretion function and the absorbed fraction by ingestion. The model is very valuable to evaluate the lung exposure to Radon decay products on the basis of the 210 Pb- 210 Po urinary excretions

  11. Studies of {sup 194,195,197}Po

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, M.P.; Ahmad, I.; Crowell, B. [and others

    1995-08-01

    The energy systematics of low-lying polonium states show sudden changes near N = 114. The observed drops in the low-lying levels of {sup 196,198}Po relative to the heavier isotopes indicate significant changes in the underlying structure of these nuclei. It is thought that this change is due to the onset of vibrational collectivity brought about by the quadrupole interaction between neutron and proton-pairs. In order to extend the Po systematics even further, we measured, for the first time, states in {sup 194,195,197}Po using the {sup 28}Si + {sup 170}Yb reaction at a beam energy of 142 MeV. The beam was supplied by ATLAS, and the data were taken with 10 Compton-suppressed Ge detectors placed at the target position of the Fragment Mass Analyzer. Preliminary level schemes were constructed for {sup 194,195,197}Po based on {gamma}-{gamma} and {gamma}-FMA coincidences. The results for {sup 194}Po show that the 2{sup +} - 0{sup +} transition energy decreased in energy by 140 keV relative to {sup 196}Po suggesting that this nucleus moved beyond the vibrational limit to more collective motion. An extrapolation of the systematics predicts that the 2{sup +} energy could drop another 140 keV between {sup 194}Po and {sup 192}Po which would indicate the onset of rotational motion. Currently, we have an approved experiment to investigate the decay of yrast isomers in {sup 194}Po which will allow us to (1) confirm our earlier level scheme of {sup 194}Po, and (2) assess the experimental conditions needed for a future study of {sup 192}Po.

  12. Concentration of 210Po in cigars

    International Nuclear Information System (INIS)

    Kelecom, Alphonse; Gouvea, Rita C.S.; Santos, Pedro L.

    2000-01-01

    210 Po concentrations have been determined in 57 different cigar brands manufactured in 11 countries. Cuban and American cigars showed the lowest 210 Po content. The mean levels of 210 Po in Brazilian cigars were almost equal to those of European and Dominican cigars, and somewhat lower than cigars from Central American countries. (author)

  13. The system Ba(H2PO4)2-Sr(H2PO4)2-H3PO4(30%)-H2O at 25, 40 and 60 deg C

    International Nuclear Information System (INIS)

    Taranenko, N.P.; Serebrennikova, G.M.; Stepin, B.D.; Oboznenko, Yu.V.

    1982-01-01

    The system Ba(H 2 PO 4 ) 2 -Sr(H 2 PO 4 ) 2 -H 3 PO 4 (30%)-H 2 O (25 deg C) belongs to eutonic type systems. Solubility isotherms of salt components at 40 and 60 deg C are calculated. Polytherms (25-60 deg C) of solubility of monosubstituted barium and strontium phosphates in 30-60% H 3 PO 4 are obtained. The value of cocrystallization coefficient of Sr 2 + and Ba(H 2 PO 4 ) 2 Dsub(Sr)=0.042+-0.005 remains stable in the temperature range of 25-60 deg C and concentrations 30-60% phosphoric acid at initial content [Sr 2 + ]=1x10 - 2 mass%

  14. Heat capacity of Sr10(PO4)6Cl2 and Ca10(PO4)6Cl2 by DSC

    International Nuclear Information System (INIS)

    Venkata Krishnan, R.; Jena, Hrudananda; Govindan Kutty, K.V.; Nagarajan, K.

    2008-01-01

    Strontium and calcium chloroapatites were synthesized by wet chemical method, characterized by X-ray diffraction and are found to be phase pure materials. The measured room temperature lattice parameter of Ca 10 (PO 4 ) 6 Cl 2 is a = 9.523 A, c = 6.855 A and for Sr 10 (PO 4 ) 6 Cl 2 is a = 9.876 A, c = 7.188 A. Heat capacity measurements were carried out on Ca 10 (PO 4 ) 6 Cl 2 and Sr 10 (PO 4 ) 6 Cl 2 by DSC in the temperature range 298-800 K. The heat capacity values of Sr 10 (PO 4 ) 6 Cl 2 is higher at all temperatures than Ca 10 (PO 4 ) 6 Cl 2 . Enthalpy and entropy increments were computed. Heat capacity values of Ca 10 (PO 4 ) 6 Cl 2 and Sr 10 (PO 4 ) 6 Cl 2 at 298 K are 758 and 868 J K -1 mol -1 , respectively

  15. Half-life of 214Po and 212Po measured with CTF at LNGS

    International Nuclear Information System (INIS)

    Bellini, G.; Benziger, J.; Bick, D.

    2013-01-01

    Polonium isotopes 214 Po and 212 Po are part of the 238 U and 232 Th decay chains, respectively. There exist only a few measurements of these two mean lifetimes with precision better than one or two percent. Since we have been studying decay spectra of 214 Bi and 212 Bi with the purpose of experimentally constraining anti-neutrino spectral shape important for geoneutrino studies, we have a large statistics of decays of 214 Po and 212 Po collected with the Counting Test Facility (CTF), which was operational in the underground I.N.F.N. Gran Sasso National Laboratory. The apparatus consisted of an external cylindrical water tank (diameter ∼ 11 m, high ∼ 10 m; ∼ 1000 tons of water) serving as passive shielding for 4.8 m 3 of liquid organic scintillator contained in an inner spherical vessel with a diameter of ∼ 2 m. The inner vessel was realized with a nylon membrane (∼ 500 ?m thick), with excellent optical clarity, which allowed the effective transmission of the scintillation light to the 100 phototubes (PMTs) forming the optical read-out, anchored on a 7 m diameter support structure inside the water tank. The high purity and low background in CTF allows a favourable signal to background ratio for these measurements. More specifically the ratio of signal to background of the present measurements is more than three orders of magnitude larger than the best existing measurements. We have studied the decays of 214 Po into 210 Pb and of 212 Po into 208 Pb tagged by the coincidence with the previously decays from 214 Bi and 212 Bi by using 222 Rn, 232 Th and 220 Rn sources sealed inside quartz vials and inserted in the CTF

  16. Effect of excitation energy and angular momentum on the characteristics of 208Po and 210Po compound nucleus fission fragments

    International Nuclear Information System (INIS)

    Itkis, M.G.; Kalpakchieva, R.; Okolovich, V.N.; Penionzhkevich, Yu.Eh.; Tolstikov, V.N.

    1982-01-01

    To study characteristics of fissioning nucleus fragments, investigated were reactiiiiiiiiiiiiiiiH8Pt+ 12 C → 210 Po in the 12 C ion energy range of 86-110.5 MeV, of 192 Os+ 16 O → 208 Po in 90-131 MeV range, 204 Pb+ 3 He → 207 Po, 206 Pb+ 3 He → 209 Po, 207 Pb+ 3 He → 210 Po with 60 MeV 3 He ion energy. Using a correlation technique for measuring energies of two fragments mass and energy distributions of fission fragments of 208 Po and 210 Po compound nuclei produced in the reactions have been studied. Mass and energy distributions of fragments from fission of 208 Po and 210 Po in the reactions with ions 16 O, 12 C and 3 He were investigated in an ample energy range, using the correlational techniques for measurement of energies of two fragments. An increase in the total kinetic energy with rise of the angular momentum was observed, the fact indicating a weak coupling of one-particle and collective modes of motion in the fissile nucleus resulting in that the rolational energy is transfered mainly to translation energies of the fragments

  17. Personal monitoring of 218Po and 214Po radionuclide deposition onto individuals under normal environmental exposure conditions

    International Nuclear Information System (INIS)

    Eatough, J.P.; Worley, A.; Moss, G.R.

    1999-01-01

    Personal dosemeters have been utilized to monitor the deposition of the radon decay products 218 Po and 214 Po onto individuals under normal environmental exposure conditions. Each detector consists of TASTRAK alpha-sensitive plastic incorporated into an ordinary working wristwatch. Subsequent analysis provides energy discrimination of the detected alpha-particle decays, and allows events from the individual radon decay products 218 Po and 214 Po, attached to the detector surface, to be uniquely identified. Assuming similar deposition onto skin and detector surfaces, the activity per unit area of deposited radionuclides can be determined for exposed skin. Forty-one personal dosemeters were issued to volunteers selected through the hospital medical physics departments at Reading, Northampton, Exeter and Plymouth. Each volunteer was also issued with a personal radon dosemeter to determine their individual radon exposure. The volunteers wore the two dosemeters simultaneously and continuously for a period of around one month. Correlations were observed between the radon exposure of the individual and the activity per unit area of 218 Po and 214 Po on the detector surface. From these correlations it can be estimated that at the UK average radon exposure of 20 Bq m -3 , the number of decays/cm 2 /year on continuously exposed skin surface is between 3500 and 28 000 for 218 Po, and between 7000 and 21 000 for 214 Po. These results can be combined with theoretical modelling of the dose distribution in the skin to yield the alpha-particle radiation dose to any identified target cells. (author)

  18. Aberrant PO2 values in proficiency testing.

    Science.gov (United States)

    Fonzi, C E; Clausen, J L; Mahoney, J

    1993-03-01

    We prospectively determined the frequency of aberrant vials of fluorocarbon/buffer used for proficiency testing of measurements of pH, PCO2, and PO2, using 20 duplicate vials from 12 lots of fluorocarbon/buffer and two arterial blood gas analyzers in eight reference laboratories. We defined aberrant vials as vials for which both duplicate measurements differed from the mean value of repeated measurements for the specific instrument (for each lot of testing materials) by > 0.04 for pH, > 10% of the mean or 3.0 mm Hg, whichever was greater, for PCO2; or > 10% of the mean or 6 mm Hg, whichever was greater, for PO2. Four of 1620 vials (0.25%) were aberrant, all based on PO2 measurements (range of mean values: pH, 7.181-7.631; PCO2, 12.7-65.9; PO2, 32.5-150.1) were 0.0055 for pH, 0.67 mm Hg for PCO2, and 1.65 mm Hg for PO2. Deliberate contamination of the fluorocarbon emulsion with room air, as might occur during sampling from the vial, indicated that only minor increases in PO2 (e.g., 1.0 mm Hg at PO2 of 56 mm Hg) occur when samples are aspirated. Larger increases in PO2 (mean 7.1 mm Hg at a PO2 of 66 mm Hg) occurred when the syringe samples were contaminated with room air. We conclude that isolated aberrant measurements of PO2 in blood gas proficiency testing attributable to vial contents can occur, but the frequency is very low.

  19. Accumulation of 210Po in Baltic invertebrates

    International Nuclear Information System (INIS)

    Skwarzec, B.; Falkowski, L.

    1988-01-01

    This paper presents the results of an investigation of the 210 Po contents of Baltic marine invertebrates. The 210 Po concentrations fall within the range 11.3-78.9 Bq kg -1 (dry wt), the higher values relating to polychaeta, priapulida and malacostraca and the lower levels to bivalvia. It is demonstrated that 210 Po is non-uniformly distributed within the isopod Mesidotea entomon and the bivalve Mya arenaria. The 210 Po contents of the internal organs decreasing in the order-hepatopancreas > alimentary tract > gill > muscle. Moreover, the results indicate the dominant role of the digestive organs of these invertebrates in controlling absorption and elimination of 210 Po. (author)

  20. Specific absorption spectra of hemoglobin at different PO2 levels: potential noninvasive method to detect PO2 in tissues.

    Science.gov (United States)

    Liu, Peipei; Zhu, Zhirong; Zeng, Changchun; Nie, Guang

    2012-12-01

    Hemoglobin (Hb), as one of main components of blood, has a unique quaternary structure. Its release of oxygen is controlled by oxygen partial pressure (PO2). We investigate the specific spectroscopic changes in Hb under different PO2 levels to optimize clinical methods of measuring tissue PO2. The transmissivity of Hb under different PO2 levels is measured with a UV/Vis fiber optic spectrometer. Its plotted absorption spectral curve shows two high absorption peaks at 540 and 576 nm and an absorption valley at 560 nm when PO2 is higher than 100 mm Hg. The two high absorption peaks decrease gradually with a decrease in PO2, whereas the absorption valley at 560 nm increases. When PO2 decreases to approximately 0 mm Hg, the two high absorption peaks disappear completely, while the absorption valley has a hypochromic shift (8 to 10 nm) and forms a specific high absorption peak at approximately 550 nm. The same phenomena can be observed in visible reflectance spectra of finger-tip microcirculation. Specific changes in extinction coefficient and absorption spectra of Hb occur along with variations in PO2, which could be used to explain pathological changes caused by tissue hypoxia and for early detection of oxygen deficiency diseases in clinical monitoring.

  1. Radioactive 210Po in magnesium supplements

    International Nuclear Information System (INIS)

    Struminska-Parulska, Dagmara Ida

    2016-01-01

    The aim of this pioneer study was to determine polonium 210 Po in the most popular magnesium supplements in Poland and estimate the possible related dose assessment to the consumers. The analyzed magnesium pharmaceutics contained organic or inorganic magnesium compounds; some from natural sources. The objectives of this research were to investigate the naturally occurring 210 Po activity concentrations in magnesium supplements, find the correlations between 210 Po concentration in medicament and magnesium chemical form, and calculate the effective radiation dose connected to analyzed magnesium supplement consumption. The highest 210 Po activity concentrations were determined in mineral tablets made from sedimentary rocks, namely dolomite - 3.84 ± 0.15 mBq g -1 (sample Mg17). The highest annual radiation dose from 210 Po taken with 1 tablet of magnesium supplement per day or with 400 mg of pure Mg daily would come from sample Mg17 (dolomite) - 1.35 ± 0.5 and 8.44 ± 0.33 μSv year -1 respectively.

  2. The phase transition of the incommensurate phases β-Ln(PO3)3(Ln=Y,Tb…Yb), crystal structures of α-Ln(PO3)3(Ln=Y,Tb…Yb) and Sc(PO3)3

    Science.gov (United States)

    Höppe, Hennig A.

    2009-07-01

    The incommensurately modulated room-temperature phases β-Ln(PO3)3(Ln=Y,Tb…Yb) undergo a topotactic phase transition monitored by vibrational spectroscopy below 180 K leading to α-Ln(PO3)3(Ln=Y,Dy…Yb), above 200 K the incommensurate phases are reobtained. The low-temperature phases exhibit a new structure type (α-Dy(PO3)3, P21/c, Z=12,a=14.1422(6), b=20.0793(9),c=10.1018(4) A˚, β=127.532(3)∘). α-Tb(PO3)3 is isotypic with Gd(PO3)3(α-Tb(PO3)3, I2/a,Z=16,a=25.875(6), b=13.460(3), c=10.044(2) A˚, β=119.13(3)∘). The symmetry relations between the involved phases of the phase transition are discussed. The crystal structure of Sc(PO3)3 is isotypic with that of Lu(PO3)3 and C-type phosphates. The polyphosphates consist of infinite zig-zag chains of corner-sharing PO4 tetrahedra, the cations are coordinated sixfold in an almost octahedral arrangement. To confirm the quality of the determined crystal structures the deviation of the phosphate tetrahedra from ideal symmetry was determined and discussed.

  3. Conductivity And Thermal Stability of Solid Acid Composites CsH2PO4 /NaH2PO4/ SiO2

    International Nuclear Information System (INIS)

    Norsyahida Mohammad; Abu Bakar Mohamad; Abu Bakar Mohamad; Abdul Amir Hassan Kadhum

    2016-01-01

    Solid acid composites CsH 2 PO 4 / NaH 2 PO 4 / SiO 2 with different mole ratios of CsH 2 PO 4 and NaH 2 PO 4 to SiO 2 were synthesized and characterized. Preliminary infrared measurements of CsH 2 PO 4 and its composites indicated that hydrogen bonds breaking and formation were detected between 1710 to 2710 cm -1 , while the rotation of phosphate tetrahedral anions occurred between 900 and 1200 cm -1 . The superprotonic transition of CsH 2 PO 4 / NaH 2 PO 4 / SiO 2 composite was identified at superprotonic temperatures between 230 and 260 degree Celcius, under atmospheric pressure. This study reveals higher conductivity values for composites with higher CsH 2 PO 4 (CDP) content. Solid acid composite CDP 613 appeared as the composite with the highest conductivity that is 7.2x10 -3 S cm -1 at 230 degree Celcius. Thermal stability of the solid acid composites such as temperature of dehydration, melting and decomposition were investigated. The addition of NaH 2 PO 4 lowers the dehydration temperature of the solid acid composites. (author)

  4. 210Pb and 210Po in tobacco - with a special focus on estimating the doses of 210Po to man

    International Nuclear Information System (INIS)

    Takizawa, Y.; Zhang, L.; Zhao, L.

    1994-01-01

    Inhalation of tobacco smoke is ranked second to food as a source of 210 Pb and 210 Po exposure to man. assay of 210 Pb and 210 Po in commercially available tobacco collected from many countries have been carried out to assess the potential risk from 210 Po present in tobacco. The range of 210 Po contained in the tobacco grands varied from 10.08 to 15.0 mBq/tob or 13.0 to 20.1 mBq/g and the mean was 11.6 mBq/tob or 15.4 mBq/g. During the International Standard Smoking process about 50% of 210 Po present in tobaccos was transferred into the smoke and the other 50% remained in the ash and butt. About 10% of the total 210 Po of tobacco was inhaled by smoke through mainstream smoke. One pack-a-day smoker inhaled 24 mBq of 210 Po per day through smoking and the annual inhalation was 8.8 Bq. The risk of mortality from lung cancer caused by 210 Po in tobaccos was 18 per million persons for the above model. (author) 6 refs.; 1 fig.; 4 tabs

  5. The phase transition of the incommensurate phases β-Ln(PO3)3(Ln=Y,Tb...Yb), crystal structures of α-Ln(PO3)3(Ln=Y,Tb...Yb) and Sc(PO3)3

    International Nuclear Information System (INIS)

    Hoeppe, Hennig A.

    2009-01-01

    The incommensurately modulated room-temperature phases β-Ln(PO 3 ) 3 (Ln=Y,Tb...Yb) undergo a topotactic phase transition monitored by vibrational spectroscopy below 180 K leading to α-Ln(PO 3 ) 3 (Ln=Y,Dy...Yb), above 200 K the incommensurate phases are reobtained. The low-temperature phases exhibit a new structure type (α-Dy(PO 3 ) 3 ,P2 1 /c,Z=12,a=14.1422(6),b=20.0793(9),c=10.1018(4)A, β=127.532(3) 0 ). α-Tb(PO 3 ) 3 is isotypic with Gd(PO 3 ) 3 (α-Tb(PO 3 ) 3 ,I2/a,Z=16,a=25.875(6),b=13.460(3),c=10.044(2)A, β=119.13(3) 0 ). The symmetry relations between the involved phases of the phase transition are discussed. The crystal structure of Sc(PO 3 ) 3 is isotypic with that of Lu(PO 3 ) 3 and C-type phosphates. The polyphosphates consist of infinite zig-zag chains of corner-sharing PO 4 tetrahedra, the cations are coordinated sixfold in an almost octahedral arrangement. To confirm the quality of the determined crystal structures the deviation of the phosphate tetrahedra from ideal symmetry was determined and discussed. - Abstract: Basic structure from which all crystal structures of the late lanthanoids' polyphosphates at room temperature and below can be derived.

  6. A high-temperature Raman scattering study of the phase transitions in GaPO{sub 4} and in the AlPO{sub 4}-GaPO{sub 4} system

    Energy Technology Data Exchange (ETDEWEB)

    Angot, E [Laboratoire des Colloides, des Verres et des Nanomateriaux, UMR CNRS 5587, Universite Montpellier II, cc026, Place E Bataillon, F-34095 Montpellier Cedex 5 (France); Parc, R Le [Laboratoire des Colloides, des Verres et des Nanomateriaux, UMR CNRS 5587, Universite Montpellier II, cc026, Place E Bataillon, F-34095 Montpellier Cedex 5 (France); Levelut, C [Laboratoire des Colloides, des Verres et des Nanomateriaux, UMR CNRS 5587, Universite Montpellier II, cc026, Place E Bataillon, F-34095 Montpellier Cedex 5 (France); Beaurain, M [Laboratoire de Physicochimie de la Matiere Condensee, UMR CNRS 5617, Universite Montpellier II, cc003, Place E Bataillon, F-34095 Montpellier Cedex 5 (France); Armand, P [Laboratoire de Physicochimie de la Matiere Condensee, UMR CNRS 5617, Universite Montpellier II, cc003, Place E Bataillon, F-34095 Montpellier Cedex 5 (France); Cambon, O [Laboratoire de Physicochimie de la Matiere Condensee, UMR CNRS 5617, Universite Montpellier II, cc003, Place E Bataillon, F-34095 Montpellier Cedex 5 (France); Haines, J [Laboratoire de Physicochimie de la Matiere Condensee, UMR CNRS 5617, Universite Montpellier II, cc003, Place E Bataillon, F-34095 Montpellier Cedex 5 (France)

    2006-05-03

    Al{sub 1-x}Ga{sub x}PO{sub 4} solid solutions (x = 0.2, 0.3, 0.38, 0.7) and the pure AlPO{sub 4} (x = 0) and GaPO{sub 4} (x = 1) end members with the {alpha}-quartz-type structure were studied by Raman scattering. An investigation as a function of composition enabled the various modes to be assigned, in particular coupled and decoupled vibrations. The tetrahedral tilting modes, which have been linked to high-temperature phase transitions to {beta}-quartz-type forms, were found to be decoupled. In addition, it is shown that Raman spectroscopy is a powerful technique for determining the gallium content of these solid solutions. Single crystals with x = 0.2, 0.38, and 1.0 (GaPO{sub 4}) were investigated at high temperature. The composition Al{sub 0.8}Ga{sub 0.2}PO{sub 4} was found to exhibit sequential transitions upon heating to the {beta}-quartz and {beta}-cristobalite forms at close to 993 K and 1073 K, respectively. Direct {alpha}-quartz-{beta}-cristobalite transitions were observed for the two other compositions at close to 1083 K and 1253 K, respectively, upon heating. The spectra of the {beta}-quartz and {beta}-cristobalite forms indicate the presence of significant disorder. Back transformation to the {alpha}-quartz-type form occurred readily with a hysteresis of less than 100 K for the composition x = 0.38 and for pure GaPO{sub 4}. Rapid cooling was necessary to obtain the metastable {alpha}-cristobalite form. In contrast, for Al{sub 0.80}Ga{sub 0.20}PO{sub 4}, the {alpha}-cristobalite form was obtained even upon slow cooling.

  7. Comparison of electrochemical performances of olivine NaFePO4 in sodium-ion batteries and olivine LiFePO4 in lithium-ion batteries.

    Science.gov (United States)

    Zhu, Yujie; Xu, Yunhua; Liu, Yihang; Luo, Chao; Wang, Chunsheng

    2013-01-21

    Carbon-coated olivine NaFePO(4) (C-NaFePO(4)) spherical particles with a uniform diameter of ∼80 nm are obtained by chemical delithiation and subsequent electrochemical sodiation of carbon-coated olivine LiFePO(4) (C-LiFePO(4)), which is synthesized by a solvothermal method. The C-NaFePO(4) electrodes are identical (particle size, particle size distribution, surface coating, and active material loading, etc.) to C-LiFePO(4) except that Li ions in C-LiFePO(4) are replaced by Na ions, making them ideal for comparison of thermodynamics and kinetics between C-NaFePO(4) cathode in sodium-ion (Na-ion) batteries and C-LiFePO(4) in lithium-ion (Li-ion) batteries. In this paper, the equilibrium potentials, reaction resistances, and diffusion coefficient of Na in C-NaFePO(4) are systematically investigated by using the galvanostatic intermittent titration technique (GITT), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), and compared to those of the well-known LiFePO(4) cathodes in Li-ion batteries. Due to the lower diffusion coefficient of Na-ion and higher contact and charge transfer resistances in NaFePO(4) cathodes, the rate performance of C-NaFePO(4) in Na-ion batteries is much worse than that of C-LiFePO(4) in Li-ion batteries. However, the cycling stability of C-NaFePO(4) is almost comparable to C-LiFePO(4) by retaining 90% of its capacity even after 100 charge-discharge cycles at a charge-discharge rate of 0.1 C.

  8. Una poética del pliegue

    Directory of Open Access Journals (Sweden)

    Ana Porrúa

    2000-11-01

    Full Text Available La producción de Juan Gelman-de Violín y otras cuestiones a Relaciones- puede inscribirse dentro de la poética sesentista caracterizada por la hegemonía de la narración y la apertura del discurso poético al resto de los discursos sociales, pero también establece una compleja relación con las vanguardias históricas. La noción de pliegue permite revisar las articulaciones de este conflicto; como espacio el pliegue separa ambas poéticas, la "coloquialista" y vanguardista, que pueden leerse en el interior del corpus propuesto en estado puro, yuxtapuestas, o bajo la forma del cruce que instala la polémica entre libros o textos de un mismo libro. La idea depliegue como rasgo operatorio permite, por su parte, revisar la relación entre ambas poéticas en el interior de un poema, focalizando la materia, el lenguaje. En este caso la poética vanguardista funciona como cuestionamiento de la linealidad del texto sesentista.

  9. Una poética del pliegue

    Directory of Open Access Journals (Sweden)

    Ana Porrúa

    2001-11-01

    Full Text Available La producción de Juan Gelman-de Violín y otras cuestiones a Relaciones- puede inscribirse dentro de la poética sesentista caracterizada por la hegemonía de la narración y la apertura del discurso poético al resto de los discursos sociales, pero también establece una compleja relación con las vanguardias históricas. La noción de pliegue permite revisar las articulaciones de este conflicto; como espacio el pliegue separa ambas poéticas, la "coloquialista" y vanguardista, que pueden leerse en el interior del corpus propuesto en estado puro, yuxtapuestas, o bajo la forma del cruce que instala la polémica entre libros o textos de un mismo libro. La idea depliegue como rasgo operatorio permite, por su parte, revisar la relación entre ambas poéticas en el interior de un poema, focalizando la materia, el lenguaje. En este caso la poética vanguardista funciona como cuestionamiento de la linealidad del texto sesentista.

  10. Ternary phosphates in Ca3(PO4)2-Na3Ln(PO4)2 (Ln-Nd, Eu, Er) systems

    International Nuclear Information System (INIS)

    Lazoryak, B.I.; Ivanov, L.N.; Strunenkova, T.V.; Golubev, V.N.; Viting, B.N.

    1990-01-01

    Ternary phosphates, formed in Ca 3 (PO 4 ) 2 -Na 3 Ln(PO 4 ) 2 (Ln-Nd, Eu, Er) systems were investigated by the methods of X-ray phase, luminescent analyses and IR spectroscopy. 5 regions of homogeneity were found. Two of them (I and II) were distinguished for all systems. Samples in the region of up to 14.285 mol.% Na 3 Ln(PO 4 ) 2 crystallize on the basis of β-Ca 3 (PO 4 ) 2 structure, and in other homogeneity regions - on the basis of β-K 2 SO 4 structure

  11. Poétique de l’invective dans les Poèmes aristophanesques de Laurent Tailhade

    Directory of Open Access Journals (Sweden)

    Laurent Robert

    2012-04-01

    Full Text Available Parmi l’abondant corpus traité par Marc Angenot dans La Parole pamphlétaire, les ouvrages de Laurent Tailhade Au Pays du mufle et À travers les Grouins [sic] constituent les seuls recueils poétiques. L’essayiste y voit une illustration du genre de la satire poétique, revivifié dès la fin du xviiie siècle avec les Iambes d’André Chénier, puis au xixe notamment par Auguste Barbier et Victor Hugo. Tailhade pourrait ainsi, superficiellement, être considéré comme le poète satiriste de la Troisième...

  12. Measurement of 210Po in vegetables of Gudalore

    International Nuclear Information System (INIS)

    Selvasekarapandian, S.; Sivakumar, R.; Mugunthamanikandan, N.; Ragunath, V.M.; Meenashisundaram, V.

    1999-01-01

    Intake of 210 Po with food was determined for the population in Gudalore taluka of Nilgiri district. The content of 210 Po in different vegetable samples was determined. The annual intake of 210 Po due different vegetables was estimated on the basis of their average annual consumption. The intake of 210 Po varied from 0.056 to 11.97 Bq/kg. The largest intake of 210 Po was with tapioca. From the intake annual effective dose was calculated. Effective dose equivalent due to polonium in different vegetables varied between 0.0121 to 2.872 μSv/Y. (author)

  13. PO2 cycling reduces diaphragm fatigue by attenuating ROS formation.

    Science.gov (United States)

    Zuo, Li; Diaz, Philip T; Chien, Michael T; Roberts, William J; Kishek, Juliana; Best, Thomas M; Wagner, Peter D

    2014-01-01

    Prolonged muscle exposure to low PO2 conditions may cause oxidative stress resulting in severe muscular injuries. We hypothesize that PO2 cycling preconditioning, which involves brief cycles of diaphragmatic muscle exposure to a low oxygen level (40 Torr) followed by a high oxygen level (550 Torr), can reduce intracellular reactive oxygen species (ROS) as well as attenuate muscle fatigue in mouse diaphragm under low PO2. Accordingly, dihydrofluorescein (a fluorescent probe) was used to monitor muscular ROS production in real time with confocal microscopy during a lower PO2 condition. In the control group with no PO2 cycling, intracellular ROS formation did not appear during the first 15 min of the low PO2 period. However, after 20 min of low PO2, ROS levels increased significantly by ∼30% compared to baseline, and this increase continued until the end of the 30 min low PO2 condition. Conversely, muscles treated with PO2 cycling showed a complete absence of enhanced fluorescence emission throughout the entire low PO2 period. Furthermore, PO2 cycling-treated diaphragm exhibited increased fatigue resistance during prolonged low PO2 period compared to control. Thus, our data suggest that PO2 cycling mitigates diaphragm fatigue during prolonged low PO2. Although the exact mechanism for this protection remains to be elucidated, it is likely that through limiting excessive ROS levels, PO2 cycling initiates ROS-related antioxidant defenses.

  14. PO2 cycling reduces diaphragm fatigue by attenuating ROS formation.

    Directory of Open Access Journals (Sweden)

    Li Zuo

    Full Text Available Prolonged muscle exposure to low PO2 conditions may cause oxidative stress resulting in severe muscular injuries. We hypothesize that PO2 cycling preconditioning, which involves brief cycles of diaphragmatic muscle exposure to a low oxygen level (40 Torr followed by a high oxygen level (550 Torr, can reduce intracellular reactive oxygen species (ROS as well as attenuate muscle fatigue in mouse diaphragm under low PO2. Accordingly, dihydrofluorescein (a fluorescent probe was used to monitor muscular ROS production in real time with confocal microscopy during a lower PO2 condition. In the control group with no PO2 cycling, intracellular ROS formation did not appear during the first 15 min of the low PO2 period. However, after 20 min of low PO2, ROS levels increased significantly by ∼30% compared to baseline, and this increase continued until the end of the 30 min low PO2 condition. Conversely, muscles treated with PO2 cycling showed a complete absence of enhanced fluorescence emission throughout the entire low PO2 period. Furthermore, PO2 cycling-treated diaphragm exhibited increased fatigue resistance during prolonged low PO2 period compared to control. Thus, our data suggest that PO2 cycling mitigates diaphragm fatigue during prolonged low PO2. Although the exact mechanism for this protection remains to be elucidated, it is likely that through limiting excessive ROS levels, PO2 cycling initiates ROS-related antioxidant defenses.

  15. Structural and Electrochemical Characterization of Pure LiFePO4 and Nanocomposite C-LiFePO4 Cathodes for Lithium Ion Rechargeable Batteries

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2009-01-01

    Full Text Available Pure lithium iron phosphate (LiFePO4 and carbon-coated LiFePO4 (C-LiFePO4 cathode materials were synthesized for Li-ion batteries. Structural and electrochemical properties of these materials were compared. X-ray diffraction revealed orthorhombic olivine structure. Micro-Raman scattering analysis indicates amorphous carbon, and TEM micrographs show carbon coating on LiFePO4 particles. Ex situ Raman spectrum of C-LiFePO4 at various stages of charging and discharging showed reversibility upon electrochemical cycling. The cyclic voltammograms of LiFePO4 and C-LiFePO4 showed only a pair of peaks corresponding to the anodic and cathodic reactions. The first discharge capacities were 63, 43, and 13 mAh/g for C/5, C/3, and C/2, respectively for LiFePO4 where as in case of C-LiFePO4 that were 163, 144, 118, and 70 mAh/g for C/5, C/3, C/2, and 1C, respectively. The capacity retention of pure LiFePO4 was 69% after 25 cycles where as that of C-LiFePO4 was around 97% after 50 cycles. These results indicate that the capacity and the rate capability improved significantly upon carbon coating.

  16. (Solid + liquid) phase equilibria of (Ca(H2PO2)2 + CaCl2 + H2O) and (Ca(H2PO2)2 + NaH2PO2 + H2O) ternary systems at T = 323.15 K

    International Nuclear Information System (INIS)

    Cao, Hong-yu; Zhou, Huan; Bai, Xiao-qin; Ma, Ruo-xin; Tan, Li-na; Wang, Jun-min

    2016-01-01

    Graphical abstract: Solubility diagram of the (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) system at T = (323.15 and 298.15) K. - Highlights: • Phase diagrams of Ca 2+ -H 2 PO 2 − -Cl − -H 2 O, Ca 2+ -Na + -H 2 PO 2 − -H 2 O at 323.15 K were obtained. • Incompatible double salt of NaCa(H 2 PO 2 ) 3 in Ca 2+ -Na + -H 2 PO 2 − -H 2 O system was determined. • Density diagram of the corresponding liquid were simultaneously measured. - Abstract: Calcium hypophosphite has been widely used as an anti-corrosive agent, flame retardant, fertilizer, assistant for Ni electroless plating, and animal nutritional supplement. High purity calcium hypophosphite can be synthesized via the replacement reaction of sodium hypophosphite and calcium chloride. In this work, the (solid + liquid) phase equilibria of (Ca(H 2 PO 2 ) 2 + CaCl 2 + H 2 O) and (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) ternary systems at T = 323.15 K were studied experimentally via the classical isothermal solubility equilibrium method, and the phase diagrams for these two systems were obtained. It was found that two solid salts of CaCl 2 ·2H 2 O and Ca(H 2 PO 2 ) 2 exist in the (Ca(H 2 PO 2 ) 2 + CaCl 2 + H 2 O) system, and three salts of Ca(H 2 PO 2 ) 2 , NaH 2 PO 2 ·H 2 O and one incompatible double salt, NaCa(H 2 PO 2 ) 3 occur in the (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) system.

  17. Density functional theory study of lithium diffusion at the interface between olivine-type LiFePO4 and LiMnPO4

    Science.gov (United States)

    Shi, Jianjian; Wang, Zhiguo; Qing Fu, Yong

    2016-12-01

    Coating LiMnPO4 with a thin layer of LiFePO4 shows a better electrochemical performance than the pure LiFePO4 and LiMnPO4, thus it is critical to understand Li diffusion at their interfaces to improve the performance of electrode materials. Li diffusion at the (1 0 0)\\text{LiFeP{{\\text{O}}4}} //(1 0 0)\\text{LiMnP{{\\text{O}}4}} , (0 1 0)\\text{LiFeP{{\\text{O}}4}} //(0 1 0)\\text{LiMnP{{\\text{O}}4}} , and (0 0 1)\\text{LiFeP{{\\text{O}}4}} //(0 0 1)\\text{LiMnP{{\\text{O}}4}} interfaces between LiFePO4 and LiMnPO4 was investigated using density functional theory. The calculated diffusion energy barriers are 0.55 eV for Li to diffuse along the (0 0 1) interface, 0.44 and 0.49 eV for the Li diffusion inside the LiMnPO4 and along the (1 0 0) interface, respectively. When Li diffuses from the LiFePO4 to LiMnPO4 by passing through the (0 1 0) interfaces, the diffusion barriers are 0.45 and 0.60 eV for the Li diffusions in both sides. The diffusion barriers for Li to diffuse in LiMnPO4 near the interfaces decrease compared with those in the pure LiMnPO4. The calculated diffusion coefficient of Li along the (1 0 0) interface is in the range of 3.65  ×  10-11-5.28  ×  10-12 cm2 s-1, which is larger than that in the pure LiMnPO4 with a value of 7.5  ×  10-14 cm2 s-1. Therefore, the charging/discharging rate performance of the LiMnPO4 can be improved by surface coating with the LiFePO4.

  18. Assessment of 210Po in foodstuffs consumed in Korea

    International Nuclear Information System (INIS)

    Chang Woo Lee; Mun Ja Kang; Wanno Lee; Geun Sik Choi; Young Hyun Cho; Hee Reyoung Kim; Kun Ho Chung

    2009-01-01

    210 Po in the daily diet in Korea was analyzed and the ingestion dose from an intake of 210 Po was estimated by considering the dietary habit of a Korean person. The 210 Po concentrations of a leafy vegetable (0.36 Bq x kg -1 for lettuce) in the terrestrial food were higher than those of grain, whereas Chinese cabbage had a lesser 210 Po concentration (0.019 Bq x kg -1 ). The 210 Po concentration of the animal product was similar to those detected in the grain and vegetable. The 210 Po concentrations in the shell and crustaceous were high from 19.1 to 33.0 Bq x kg -1 , however, its value fell in the overall range of the reported values. The effective dose from 210 Po for an adult from the Korean population was about 269.4 μSv x y -1 . Nearly 80% of the ingestion dose from the intake of 210 Po was attributed to the consumption of seafood. It suggests that the marine food ingestion is a critical pathway for natural 210 Po to the Korean population. (author)

  19. Vibrational modes of deuterium in KD2PO4

    International Nuclear Information System (INIS)

    Mizoguchi, Kohji; Agui, Akane; Tominaga, Yasunori; Nakai, Yusuke; Ikeda, Susumu.

    1993-01-01

    In order to study the deuteration effect in hydrogen-bonded compounds such as KH 2 PO 4 , hydrogen and deuterium modes in KH 2 PO 4 and K(D x H 1-x ) 2 PO 4 (x = 95 %) were investigated by means of inelastic neutron-scattering measurements over a wide energy range. By comparing Raman spectra of KH 2 PO 4 and KD 2 PO 4 with neutron-scattering spectra, the vibrational modes of deuterium and those of PO 4 tetrahedrons in the energy range of 30 < ε < 150 meV have been investigated. At least two deuterium modes have been found at 87 meV and 106 meV. (author)

  20. Temporal changes of 210Po in temperate coastal waters

    International Nuclear Information System (INIS)

    Wildgust, M.A.; White, K.N.; McDonald, P.

    1998-01-01

    The temporal variation of Polonium-210 ( 210 Po) was examined in coastal sea water, the mussel Mytilus edulis, the winkle Littorina littorea and green algae Ulva lactuca in order to investigate the entry of 210 Po into the marine food chain. More than 99% of 210 Po in the water column occurred in the particulate phase. Dissolved 210 Po concentrations peaked during the spring phytoplankton bloom and it is suggested this is related to preferential scavenging of 210 Po by the increased numbers of bacteria, viruses and small dissolved particulates. Changes in L. Littorea 210 Po specific activity are thought not to be related to food, but to a drop in body weight following spawning. Much of the 210 Po accumulated by M. edulis was located in the digestive gland. The specific activity of 210 Po in the digestive gland of M. edulis was shown to be strongly correlated with changes in sea water suspended particulate specific activity. Examination of other trace metal (Ag, Al, As, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni Sb, Se, Sn and Zn) variations in the digestive gland revealed that class B and borderline metals had a strong positive correlation with 210 Po. On-going work is investigating whether the accumulation and loss of 210 Po is affected by the presence of metallothioneins

  1. Temporal changes of 210Po in temperate coastal waters.

    Science.gov (United States)

    Wildgust, M A; McDonald, P; White, K N

    1998-06-18

    The temporal variation of Polonium-210 (210Po) was examined in coastal sea water, the mussel Mytilus edulis, the winkle Littorina littorea and green alga Ulva lactuca in order to investigate the entry of 210Po into the marine food chain. More than 99% of 210Po in the water column occurred in the particulate phase. Dissolved 210Po concentrations peaked during the spring phytoplankton bloom and it is suggested this is related to preferential scavenging of 210Po by the increased numbers of bacteria, viruses and small dissolved particulates. Changes in L. littorea 210Po specific activity are thought not to be related to food, but to a drop in body weight following spawning. Much of the 210Po accumulated by M. edulis was located in the digestive gland. The specific activity of 210Po in the digestive gland of M. edulis was shown to be strongly correlated with changes in sea water suspended particulate specific activity. Examination of other trace metal (Ag, Al, As, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Sb, Se, Sn and Zn) variations in the digestive gland revealed that class B and borderline metals had a strong positive correlation with 210Po. On-going work is investigating whether the accumulation and loss of 210Po is affected by the presence of metallothioneins.

  2. RbCuFe(PO42

    Directory of Open Access Journals (Sweden)

    Mongi Ben Amara

    2013-08-01

    Full Text Available A new iron phosphate, rubidium copper(II iron(III bis(phosphate, RbCuFe(PO42, has been synthesized as single crystals by the flux method. This compound is isostructural with KCuFe(PO42 [Badri et al. (2011, J. Solid State Chem. 184, 937–944]. Its structure is built up from Cu2O8 units of edge-sharing CuO5 polyhedra, interconnected by FeO6 octahedra through common corners to form undulating chains that extend infinitely along the [011] and [01-1] directions. The linkage of such chains is ensured by the PO4 tetraedra and the resulting three-dimensional framework forms quasi-elliptic tunnels parallel to the [101] direction in which the Rb+ cations are located.

  3. Effect of Phosphate Salts (Na3PO4, Na2HPO4, and NaH2PO4) on Ag3PO4 Morphology for Photocatalytic Dye Degradation under Visible Light and Toxicity of the Degraded Dye Products

    NARCIS (Netherlands)

    Amornpitoksuk, P; Intarasuwan, K; Suwanboon, S; Baltrusaitis, Jonas

    2013-01-01

    Ag3PO4 was synthesized by the precipitation method using three different types of phosphate salts (Na3PO4, Na2HPO4, and NaH2PO4) as a precipitating agent. Hydrolysis of each phosphate salt gave a specific pH that affected the purity and morphology of the prepared Ag3PO4. The Ag3PO4 prepared from

  4. Aspects on the analysis of 210Po.

    Science.gov (United States)

    Henricsson, F; Ranebo, Y; Holm, E; Roos, P

    2011-05-01

    There has been little development regarding analysis of polonium (Po) in environmental samples since the 1960 ies. This is due to the straightforward spontaneous deposition of this element on silver (Ag), nickel (Ni) or copper (Cu) without any radiochemical separation. For many years, no radiochemical yield determinant was used and it was generally supposed that the yield was 100% after two depositions. Counting was often done using ZnS scintillation counter coupled to a photomultiplier tube. However, the use of the yield determinants (208)Po and (209)Po and the development of alpha spectrometry showed that the yield was lower. Furthermore, the tendency of Po to volatilize at low temperatures constrains the sample preparation techniques; dry-ashing cannot be used. But during the wet-ashing procedure, there are still some losses. The aim of this study was to evaluate the Po losses during wet-ashing by the use of a double-tracer technique. We have found that the losses were about 30% when open glass beakers were used and about 17% when the samples were digested in microwave oven. When long-necked bottles (Kjeldahl flasks) were used, a loss of about 20% was registered. It has also been observed that (210)Pb to some extent is plating out together with its daughter nuclide Po during the electrochemical deposition. This will result in a systematic error since an unknown amount of supported (210)Po will be produced from the (210)Pb decay depending on the fraction of (210)Pb being deposited on the disc and the waiting time between deposition and measurement of the sample. A further consequence of this is that in the assessment of the (210)Pb content in the sample, very often the remaining liquid is stored after deposition for build-up of (210)Po. Since some (210)Pb is lost on the disc, the result for (210)Pb will be too low. Both these systematic errors give rise to a too high (210)Po/(210)Pb ratio. The fraction of (210)Pb which is plating out has been assessed in this

  5. Rate-dependent, Li-ion insertion/deinsertion behavior of LiFePO4 cathodes in commercial 18650 LiFePO4 cells.

    Science.gov (United States)

    Liu, Qi; He, Hao; Li, Zhe-Fei; Liu, Yadong; Ren, Yang; Lu, Wenquan; Lu, Jun; Stach, Eric A; Xie, Jian

    2014-03-12

    We have performed operando synchrotron high-energy X-ray diffraction (XRD) to obtain nonintrusive, real-time monitoring of the dynamic chemical and structural changes in commercial 18650 LiFePO4/C cells under realistic cycling conditions. The results indicate a nonequilibrium lithium insertion and extraction in the LiFePO4 cathode, with neither the LiFePO4 phase nor the FePO4 phase maintaining a static composition during lithium insertion/extraction. On the basis of our observations, we propose that the LiFePO4 cathode simultaneously experiences both a two-phase reaction mechanism and a dual-phase solid-solution reaction mechanism over the entire range of the flat voltage plateau, with this dual-phase solid-solution behavior being strongly dependent on charge/discharge rates. The proposed dual-phase solid-solution mechanism may explain the remarkable rate capability of LiFePO4 in commercial cells.

  6. Une poétique du vœu : inspiration poétique et mystique impériale dans le poème XIX (et quelques autres d’Optatianus Porfyrius

    Directory of Open Access Journals (Sweden)

    Marie-Odile Bruhat

    2010-11-01

    Full Text Available La majorité des poèmes d’Optatianus Porfyrius qui nous sont parvenus est dédiée à l’empereur Constantin et consacrée à son éloge. Mais dans cette poésie visuelle d’un nouveau genre, la célébration de l’art poétique tient une place aussi importante que la célébration impériale. Comment considérer le discours proprement poétique d’Optatianus ? Est-il simplement juxtaposé au discours politique ? Relève-t-il d’une pure convention ornementale ? Ces questions sont d’autant plus pertinentes que, loin de présenter le procédé visuel dont il est l’inventeur comme un art technicien, Optatianus revendique le double titre de poiètès et de uates et convoque les divinités de l’inspiration, Phébus et les Muses, alors même que ses poèmes se font l’écho de la nouvelle théologie chrétienne du pouvoir. La réponse apparaît double. D’une part, la poésie d’Optatianus peut être définie comme votive. Ses poèmes s’inscrivent dans la liturgie du pouvoir, c’est-à-dire dans le cadre d’une théologie impériale qui repose sur l’affirmation de l’éternité de la victoire et sur le renouvellement du charisme victorieux à travers le rituel des voeux. Par son discours sur Phébus et les Muses, Optatianus met en place une véritable poétique du voeu, qui consiste à couler la mystique de l’inspiration dans le moule de la mystique impériale. D’autre part, ce projet poétique répond à bien des égards à l’attente impériale. Il rencontre la volonté de Constantin de développer une politique culturelle, et se plie à quelques traits caractéristiques de sa religiosité : conviction de la nécessité du secours divin dans les actions humaines, d’une inspiration divine dont Constantin a fait lui-même l’expérience, attention aux signes et aux visions, attachement à un charisme solaire qui coexiste sous une forme « neutralisée » avec sa foi chrétienne. Le poème XIX, composé à l

  7. The determination of 210Po in urine

    International Nuclear Information System (INIS)

    Bale, W.F.; Helmkamp, R.W.; Hrynyszyn, V.; Contreras, M.A.

    1975-01-01

    To measure 210 Po present in normal human urine a technique was developed in which a 4.5 x 11cm silver foil was shaken at room temperature for 48-hr periods in each of two successive volumes of 1.7 l. of urine acidified to 0.5N with HCl. Alpha rays were counted with an ionization chamber, coupled to a vibrating reed electrometer, and capable of measuring α-ray pulses originating on both sides of the silver foil serving as a central electrode. The background α-count was less than 2/hr. Analyses of human urine spiked with 0.29 to 0.58pCi of 210 Po, together with studies of urine from dogs carrying significant body burdens of 210 Pb, indicated that the average recovery of added 210 Po from 1.7 l. volumes of spiked human urine was 72%. If it is assumed that the same percentage of 210 Po is extracted from non-spiked urine, then the average 210 Po concentration found in 13 analyses of 2 x 1.7 l. samples from 26 different pools of fresh human urine was 0.023pCi/l. Substantial additional 210 Po was generated on short aging of the urine through radioactive decay of excreted 210 Bi. (author)

  8. 210Po behaviour in terrestrial environment: a review

    International Nuclear Information System (INIS)

    Coppin, F.; Roussel-Debet, S.

    2004-01-01

    This bibliographical review illustrates the behaviour of 210 polonium in the terrestrial environment. Sources of 210 Po in the atmosphere vary especially with the geographical localization and the occurrence or the absence of mining activities. In soils, polonium, because of its atmospheric origin, is concentrated in the first upper centimeters. 210 Po is rather immobile and adsorbed on mineral surfaces; it can (co)precipitate with metallic (oxi)hydroxides or in the form of sulphide. The main transfer pathway of 210 Po to vegetation is foliar deposit, which is not, or only slightly, followed by incorporation or translocation. 210 Po is transferred to animals mainly by ingestion, with relatively high transfer factors. In fresh waters, 210 Po is generally immobile in the form of insoluble Po(IV) and/or associated with the particulate or colloidal phase. Plankton, invertebrates and fish concentrate the 210 Po, especially in soft tissues. Polonium, which is an omnipresent natural radionuclide, is likely to occasion a significant exposure to man, compared with other natural or artificial radioisotopes. Nearly all studies derive from in situ measurements and are very descriptive, therefore experimental work aiming at a better knowledge and modeling of its behaviour in the terrestrial environment would be useful. (author)

  9. Radioactive {sup 210}Po in magnesium supplements

    Energy Technology Data Exchange (ETDEWEB)

    Struminska-Parulska, Dagmara Ida [Gdansk Univ. (Poland). Environmental Chemistry and Radiochemistry Chair

    2016-08-01

    The aim of this pioneer study was to determine polonium {sup 210}Po in the most popular magnesium supplements in Poland and estimate the possible related dose assessment to the consumers. The analyzed magnesium pharmaceutics contained organic or inorganic magnesium compounds; some from natural sources. The objectives of this research were to investigate the naturally occurring {sup 210}Po activity concentrations in magnesium supplements, find the correlations between {sup 210}Po concentration in medicament and magnesium chemical form, and calculate the effective radiation dose connected to analyzed magnesium supplement consumption. The highest {sup 210}Po activity concentrations were determined in mineral tablets made from sedimentary rocks, namely dolomite - 3.84 ± 0.15 mBq g{sup -1} (sample Mg17). The highest annual radiation dose from {sup 210}Po taken with 1 tablet of magnesium supplement per day or with 400 mg of pure Mg daily would come from sample Mg17 (dolomite) - 1.35 ± 0.5 and 8.44 ± 0.33 μSv year{sup -1} respectively.

  10. Topotactic insertion of lithium in the layered structure Li4VO(PO4)2: The tunnel structure Li5VO(PO4)2

    International Nuclear Information System (INIS)

    Satya Kishore, M.; Pralong, V.; Caignaert, V.; Malo, S.; Hebert, S.; Varadaraju, U.V.; Raveau, B.

    2008-01-01

    A new V(III) lithium phosphate Li 5 VO(PO 4 ) 2 has been synthesized by electrochemical insertion of lithium into Li 4 VO(PO 4 ) 2 . This phase, which crystallizes in the space group I4/mcm, exhibits a tunnel structure closely related to the layered structure of Li 4 VO(PO 4 ) 2 and to the tunnel structure of VO(H 2 PO 4 ) 2 . The topotactic reactions that take place during lithium exchange and intercalation, starting from VO(H 2 PO 4 ) 2 and going to the final phase Li 5 VO(PO 4 ) 2 are explained on the basis of the flexible coordinations of V 4+ and V 3+ species. The electrochemical and magnetic properties of this new phase are also presented and explained on the basis of the structure dimensionality. - Graphical abstract: Electrochemical synthesis of a new 3D V(III) lithium phosphate, Li 5 VO(PO 4 ) 2 . Starting from the 2D Li 4 VO(PO 4 ) 2 , the topotactic reaction that take place during lithium intercalation is explained on the basis of the flexible coordinations of V 4+ and V 3+ species

  11. Sistem Informasi Pada Perusahaan Otobus (Po) Waspada Bengkulu Berbasis Web

    OpenAIRE

    -, Khairil; Koesoemanegara, Eddy

    2011-01-01

    Web Sistem Informasi pada PO. Waspada Bengkulu berguna sebagai pusat informasi dan sarana promosi untuk mempilkan profil Perusahaan dan juga untuk menawarkan produk dan pelayanan yang ditawarkan oleh PO. Waspada. Sistem informasi ini ditujukan agar PO. Waspada lebih dikenal oleh masyarakat dan akhirnya dapat meningkatkan jumlah penumpang yang menggunakan jasa PO. Waspada Bengkulu.Web Sistem Informasi PO. Waspada Bengkulu dikembangkan menggunakan web editor Adobe Dreamweaver dengan web promgra...

  12. Synthesis, crystal structure and optical properties of the catena-metaphosphates Ce(PO3)4 and U(PO3)4

    International Nuclear Information System (INIS)

    Hoeppe, Henning A.; Daub, Michi

    2012-01-01

    The catena-metaphosphates of tetravalent cerium and tetravalent uranium were obtained as phase pure crystalline powders by reaction of the respective dioxides with phosphoric acid at 500 C. Ce(PO 3 ) 4 and U(PO 3 ) 4 crystallise in space group C2/c (Z = 16, a Ce = 13.7696(3) Aa, b Ce = 29.7120(7) Aa, c Ce = 8.9269(2) Aa, β Ce = 90.00(1) Aa 3 and a U = 13.786(3) Aa, b U = 29.843(6) Aa, c U = 8.9720(18) Aa, β U = 90.01(3) Aa 3 ). The vibrational and optical spectra of pale yellow Ce(PO 3 ) 4 and emerald-greenish U(PO 3 ) 4 are also reported. (orig.)

  13. Sol–gel synthesis and electrochemical properties of 9LiFePO4·Li3V2(PO4)3/C composite cathode material for lithium ion batteries

    International Nuclear Information System (INIS)

    Zhong Shengkui; Wu Ling; Liu Jiequn

    2012-01-01

    Highlights: ► Nano-sized 9LiFePO 4 ·Li 3 V 2 (PO 4 ) 3 /C powders are prepared by a sol–gel method. ► Mutual doping in 9LiFePO 4 ·Li 3 V 2 (PO 4 ) 3 /C can improve its electronic conductivity. ► The addition of Li 3 V 2 (PO 4 ) 3 can improve the ionic diffusivity of LiFePO 4 . ► LiFePO 4 , Li 3 V 2 (PO 4 ) 3 and LiFePO 4 –Li 3 V 2 (PO 4 ) 3 unit cells coexist in the composite. - Abstract: 9LiFePO 4 ·Li 3 V 2 (PO 4 ) 3 /C composite cathode material is prepared by a sol–gel method, using ferric citrate, V 2 O 5 , Li 2 CO 3 , NH 4 H 2 PO 4 and citric acid as raw materials. The composite material is composed of the olivine LiFePO 4 and monoclinic Li 3 V 2 (PO 4 ) 3 phases. XRD results indicate that most of the iron and vanadium in the raw materials tend to form the LiFePO 4 and Li 3 V 2 (PO 4 ) 3 phases, and only small amounts of Fe and V as the dopants enter into the lattice of Li 3 V 2 (PO 4 ) 3 and LiFePO 4 , respectively. The electronic conductivity and Li + diffusion coefficient of 9LiFePO 4 ·Li 3 V 2 (PO 4 ) 3 /C are 6.615 × 10 −3 S cm −1 and ∼10 −10 cm 2 s −1 , which are three orders of magnitude and one order of magnitude larger than those of the LiFePO 4 /C, respectively. The composite material shows a first discharge specific capacity of 131.3 mAh g −1 and capacity retention of 95.1% after 200 cycles at 10 C rate. Compared with the LiFePO 4 /C, its rate capability and cycle performance are both remarkably improved.

  14. Forenzika elektronske pošte

    Directory of Open Access Journals (Sweden)

    Milorad S. Markagić

    2013-10-01

    Full Text Available U najopštijem smislu digitalna forenzika može se definisati kao skup metoda za prikupljanje, analizu i prezentaciju digitalnih dokaza koji se mogu pronaći na računarima, serverima, u računarskim mrežama, bazama podataka, mobilnim uređajima i svim drugim elektronskim uređajima na kojima se čuvaju podaci. U ovom radu su opisane metode prikupljanja digitalnih dokaza u elektronskoj pošti i njihova analiza. Uvod Elektronska pošta se kao dokazni materijal pojavljuje u velikom broju kako građanskih tako i kriminalnih forenzičkih istraga. Elektronska pošta i elektronska pošta zasnovana na internet serverima  širi se veoma brzo, pa lako i brzo završi i na računaru korisnika kome nije namenjena. Prvu elektronsku poruku poslao je Ray Tomilson 1971. godine, a deset godina kasnije u kombinaciji sa personalnim računarima i internetom prerasta u globalni način komuniciranja i personalnog i poslovnog. Takođe se koristi i u svrhu zabave, načina razmene podataka, ali predstavlja i nezamenjiv izvor digitalnih dokaza, kada dodje do računarskog incidenta. Analiza elektronske pošte Svaka elektronska poruka sastoji se od dva dela: zaglavlja i teksta poruke. Iz zaglavlja je moguće saznati izvorišnu i odredišnu adresu, pošiljaoca i namenjenog primaoca, a telo poruke sadrži tekst poruke. Ekstenzije dokumenata elektronske pošte U slučajevima kada je potrebno otkriti samo dokumente potrebne za pregled elektronskih poruka, ili kopirati pojedinačni dokument sačuvan unutar elektronske pošte, moguće je koristiti sistem na istraživanom računaru ili specijalizovani softver kao što je Outlook Extract Pro ili Outlook Export. Mnogo ispravniji, sigurniji i jednostavniji način je korišćenje forenzičkih alata kao što su EnCase ili FTK, sa ugrađenim pregledačima koji omogućavaju pregled i snimanje sadržaja baze podataka kao i njihovo kopiranje na druge medije za dalju analizu. Forenzički alati automatizuju proces skidanja i kopiranja

  15. Quantitative determination of 210Po in geochemical samples

    International Nuclear Information System (INIS)

    Dyck, W.; Bristow, Q.

    1984-01-01

    To test the usefulness of 210 Po in soils as a means of detecting buried U mineralization, methods for the determination of 210 Po were investigated and adapted for routine production of 210 Po data from geochemical samples. A number of conditions affecting autodeposition and detection of 210 Po were investigated. The optimum area of deposition with a 450 mm 2 solid state detector was found to be 300 mm 2 . Convenience dictated room temperature over-night deposition times, although increased temperature increased speed and efficiency of deposition. A clear inverse relationship was observed between volume of solution and deposition efficiency with stirring times of less than 2 hours. For routine analysis, soil and rock powders were dissolved by leaching 1 g samples in teflon beakers successively with conc. HNO 3 , HF, and HNO 3 -HClO 4 , evaporating the solution to dryness between leaches, and taking the residue up in 20 mL 0.5 M HCl. The 210 Po was deposited on 19 mm diameter Ni discs and counted with an alpha spectrometer system employing 450 mm 2 ruggedized surface barrier detectors. The method achieved 90 percent recovery of 210 Po from solution and a detection efficiency of 30 percent. With a counting time of 3 hours, the method is capable of detecting 0.2 pCi of 210 Po per gram of sample

  16. Levels of 210Po and 210Pb in cigars

    International Nuclear Information System (INIS)

    Kelecom, A.; Gouvea, R.C.S.; Santos, P.L.

    2002-01-01

    210 Po and 210 Pb concentrations have been determined in 58 cigar brands manufactured in 11 countries. Cuban and American cigars showed the lowest 210 Po content. The mean levels of 210 Po in Brazilian, European and Dominican cigars were almost identical and somewhat lower than the levels observed for cigars from other Latin American countries. Cuban, American and European cigars contained low levels of 210 Pb. Cigars from the remaining countries contained twice as much 210 Pb. The mean 210 Po/ 210 Pb ratio showed an excess of polonium. In the case of one cigar-a-day smoker, the calculated annual absorbed dose due to 210 Po is ∼16 μGy. (author)

  17. Equilibrium diagram of KPO3-Y(PO3)3 system, chemical preparation and characterization of KY(PO3)4

    International Nuclear Information System (INIS)

    Jouini, Anis; Ferid, Mokhtar; Trabelsi-Ayadi, Malika

    2003-01-01

    Microdifferential thermal analysis (μ-DTA), X-ray diffraction (XRD) and infrared (IR) spectroscopy were used for the first time to investigate the liquidus and solidus relations in the KPO 3 -Y(PO 3 ) 3 system. The only compound observed within the system was KY(PO 3 ) 4 melting incongruently at 1033 K. An eutectic appears at 13.5 mol% Y(PO 3 ) 3 at 935 K, the peritectic occurs at 1033 K and the phase transition for potassium polyphosphate KPO 3 was observed at 725 K. Three monoclinic allotropic phases of the single crystals were obtained. KY(PO 3 ) 4 polyphosphate has the P2 1 space group with lattice parameters: a=7.183(4) A, b=8.351(6) A, c=7.983(3) A, β=91.75(3) deg. and Z=2 is isostructural with KNd(PO 3 ) 4 . The second allotropic form of KY(PO 3 ) 4 belongs to the P2 1 /n space group with lattice parameters: a=10.835(3) A, b=9.003(2) A, c=10.314(1) A, β=106.09(7) deg. and Z=4 and is isostructural with TlNd(PO 3 ) 4 . The IR absorption spectra of the two forms show a chain polyphosphates structure. The last modification of KYP 4 O 12 crystallizes in the C2/c space group with lattice parameters: a=7.825(3) A, b=12.537(4) A, c=10.584(2) A, β=110.22(7) deg. and Z=4 is isostructural with RbNdP 4 O 12 and contains cyclic anions. The methods of chemical preparations, the determination of crystallographic data and IR spectra for these compounds are reported

  18. Concentrations of 210Po in fish and shellfish from southern region of Japan and evaluation of 210Po intake from seafood for Japanese people

    International Nuclear Information System (INIS)

    Momoshima, N.; Sugihara, S.; Nakao, H.

    2012-01-01

    Concentrations of 210 Po in fish and shellfish, mostly collected from southern region of Japan were analyzed. Values ranged from 0.2 to 229 Bq/kg fresh weight and higher concentrations were observed in samples analyzed with viscera. Intake of 210 Po through fish and shellfish was evaluated at different Japanese cities based on statistical consumption data. Phytoplankton, Heterosigma akashiwo was collected during a harmful algal bloom and 210 Po was analyzed. The phytoplankton occupied only 4.4% of 210 Po in seawater and a large fraction of 210 Po was observed in the particulate form. (orig.)

  19. Assessment of 210Po exposure for the Italian population

    International Nuclear Information System (INIS)

    Clemente, G.F.; Renzetti, A.; Santori, G.; Breuer, F.

    1980-01-01

    A summary is given of the data required to evaluate the 210 Po internal burden and the relative dose given to the members of the Italian general public and to those groups of subjects who are exposed in non-uranium mines and spas to high radon and daughter product air concentrations. Data on the daily intake, daily excretion, total body burden and skeletal burden of 210 Pb and 210 Po for the general public provide the components of the 210 Pb- 210 Po metabolic balance. A mathematical model has been developed on the basis of this data and can be used to evaluate the 210 Pb- 210 Po body burden of subjects exposed to high levels of radon and daughter products on the basis of their 210 Pb- 210 Po daily excretion. Data is presented for the 210 Pb- 210 Po skeletal and soft tissue burden and the yearly dose rate to the skeleton in non-smokers, smokers, non-uranium miners and spa employees. (UK)

  20. 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

  1. Research Update: Retardation and acceleration of phase separation evaluated from observation of imbalance between structure and valence in LiFePO4/FePO4 electrode

    Directory of Open Access Journals (Sweden)

    Kazuya Tokuda

    2014-07-01

    Full Text Available LiFePO4 is a potential positive electrode material for lithium ion batteries. We have experimentally observed an imbalance between the valence change of Fe ions and the structure change from the LiFePO4 phase to the FePO4 phase during delithiation by simultaneous in situ XRD and XANES measurements in an LiFePO4/FePO4 electrode. The ratio of structure change to valence change clearly indicates that the phase separation from LiFePO4 to FePO4 is suppressed at the beginning of delithiation, while it is accelerated at the latter stage, which is due to the coherent strain caused by the lattice misfit between the two phases.

  2. Synthesis and luminescence of CePO4 and CePO4:Tb hollow and core-shell microspheres composed of single-crystal nanorods

    International Nuclear Information System (INIS)

    Guan Mingyun; Sun Jianhua; Han Min; Xu Zheng; Tao Feifei; Yin Gui; Wei Xianwen; Zhu Jianmin; Jiang Xiqun

    2007-01-01

    Lanthanide phosphate microspheres composed of single-crystal CePO 4 and CePO 4 :Tb nanorods were successfully synthesized, respectively, using the functionalized composite aggregate as a template, which is composed of P123, H 6 P 4 O 13 and Ce 3+ , and also as a resource of reaction species with high chemical potential. The shape and the phase structure of the CePO 4 nanocrystal can be easily controlled via adjusting reaction temperature, monomer concentration and annealing temperature. SEM images show the spherical superstructure composed of nanorods. HRTEM and SAED images reveal the single-crystalline nature of nanorod and TEM images show the hollow interiors of the superstructure. XRD patterns indicate that the crystal structure of the nanorods is hexagonal before and monoclinic after annealing. The formation mechanism was proposed. Strong UV and green luminescence were observed for the CePO 4 and CePO 4 :Tb microspheres, respectively. The synthesis method can be extended to the fabrication of NRHS and core-shell microspheres of other rare-earth or doped LnPO 4 materials for wide applications

  3. Biogeochemical factors affecting the presence of 210Po in groundwater

    International Nuclear Information System (INIS)

    Seiler, Ralph L.; Stillings, Lisa L.; Cutler, Nichole; Salonen, Laina; Outola, Iisa

    2011-01-01

    Research highlights: → 210 Po activities in numerous domestic wells in Fallon NV exceed 500 mBq/L. → 210 Po levels in sediment are not the primary determinant on levels in groundwater. → δ 34 S measurements indicate SO 4 reduction occurred in all 210 Po contaminated wells. → 210 Po contaminated wells are anoxic, have high pH and low Ca. → Po mobilization probably involves an anaerobic S cycle in which H 2 S dissolves MnO 2 . - Abstract: The discovery of natural 210 Po enrichment at levels exceeding 500 mBq/L in numerous domestic wells in northern Nevada, USA, led to a geochemical investigation of the processes responsible for its mobilization. 210 Po activities in 63 domestic and public-supply wells ranged from below 1 mBq/L to 6590 ± 590 mBq/L, among the highest reported levels in the USA. There is little spatial or depth variability in 210 Pb activity in study-area sediments and mobilization of a few percent of the 210 Po in the sediments would account for all of the 210 Po in water. Stable-isotope measurements indicate SO 4 reduction has occurred in all 210 Po contaminated wells. Sulfide species are not accumulating in the groundwater in much of Lahontan Valley, probably because of S cycling involving microbial SO 4 reduction, abiotic oxidation of H 2 S to S 0 by Mn(IV), followed by microbial disproportionation of S 0 to H 2 S and SO 4 . The high pH, Ca depletion, MnCO 3 saturation, and presence of S 0 in Lahontan Valley groundwater may be consequences of the anaerobic S cycling. Consistent with data from naturally-enriched wells in Florida, 210 Po activities begin to decrease when aqueous sulfide species begin to accumulate. This may be due to formation and precipitation of PoS, however, Eh-pH diagrams suggest PoS would not be stable in study-area groundwater. An alternative explanation for the study area is that H 2 S accumulation begins when anaerobic S cycling stops because Mn oxides are depleted and their reduction is no longer releasing 210 Po

  4. Determination of 210 Po in cigarettes

    International Nuclear Information System (INIS)

    Peres, Ana Claudia; Hiromoto, Goro

    1999-01-01

    A radiochemical procedure for the determination of 110 Po in cigarettes is presented. The method is based on solvent extraction, followed by spontaneous deposition on copper disks and counting by alpha spectrometry. Some commercial cigarette brands available in the national market were analysed, obtaining 210 Po concentrations ranging from 15 to 26 mBq per gram of dry tobacco. (author)

  5. 210Po and 210Pb variations in fish species from the Aegean Sea and the contribution of 210Po to the radiation dose

    International Nuclear Information System (INIS)

    Mat Çatal, Ebru; Uğur, Aysun; Özden, Banu; Filizok, Işık

    2012-01-01

    In recent years, there has been increasing interest in the significance of natural radionuclides, particularly 210 Po, in the marine environment. 210 Po, a naturally occurring alpha emitter, accumulates in marine organisms and reflects differences in their diets. In the literature, there is no data for 210 Po and 210 Pb activity concentrations for fish species on the Turkish coast of Aegean Sea. Therefore, in this study, multiple fish species were collected from six stations seasonally on the Turkish coast of Aegean Sea and were analyzed for their 210 Po and 210 Pb content. The 210 Po and 210 Pb concentrations in the fish samples were found to vary from undetectable levels to 499 ± 44 Bq kg −1 dry weight (dw) and from 1.0 ± 0.3 Bq kg −1 to 35 ± 4.0 Bq kg −1 (dw), respectively. There were no significant differences in the activity concentrations of 210 Po and 210 Pb in fish samples between seasons (ANOVA, P > 0.05). The highest dose contribution of 210 Po to humans was calculated to be 10,530 μSv year −1 .

  6. Nuclear orientation and NMR/ON of sup(205,207)Po

    International Nuclear Information System (INIS)

    Herzog, P.; Walitzki, H.; Freitag, K.; Hildebrand, H.; Schloesser, K.

    1983-01-01

    sup(205,207)Po have been implanted with an isotope separator on-line into cold host matrices of Fe, Ni, Zn and Be. Nuclear magnetic resonance of oriented 207 Po has been observed in Fe and Ni, of 205 Po in Fe. From the dependence of the resonance frequency on external magnetic field the g-factor of 207 Po was derived. Using this value the magnetic hyperfine fields of Po in Fe and Ni were obtained. From the temperature dependence of the anisotropies of #betta#-lines in the decay of sup(205,207)Po the multipole mixing of several transitions was derived. The electric interaction frequencies #betta#sub(Q)=eQVsub(zz)/h in the hosts Zn and Be were measured. (orig./WL)

  7. Radiochemical determination of 210 Po in tobacco and farm food

    International Nuclear Information System (INIS)

    Chung, K. H.; Lee, H. P.; Cho, Y. H.; Choi, G. S.; Kim, C. K.; Lee, C. W.

    2002-01-01

    A method for measuring 210 Po in tobacco (cigarette and leaf) and farm food has been studied by alpha- spectrometry. Polonium was separated from HCl solution in the presence of other radionuclides and ascorbic acid (reduction of Fe 3+ ) by spontaneous deposition onto a silver disc. To determine the optimum conditions for plating polonium on a disc, the effects of reducing agent, plating time etc. were investigated. In the method, the samples are spiked with 208 Po (or 209 Po) as a chemical yield tracer. Because the main sources of 210 Po in the human body are food and cigarette smoke, this procedure to determine 210 Po has been applied to tobacco and farm food samples. Analyses of 210 Po in tobacco leaves and farm food samples using this method are in progress. The concentrations of 210 Po in cigarettes were ranged from 17 to 21 mBq/g and compared with published data on this natural radionuclide

  8. Volatilization of Po by microorganisms at laboratory culture experiments

    International Nuclear Information System (INIS)

    Momoshima, N.; Ishida, A.; Yoshinaga, C.; Fukuda, A.

    2005-01-01

    The previous experiments proved the volatility of polonium form culture medium in which microorganisms were propagated from seed of seawater, river water or pond water, therefore we did not know what kind of species are responsible to Po volatility. To search microorganisms, which concerned with Po emission we carried out culture experiments using known microorganisms. Three microorganisms were examined; Escherichia coli K-12, Bacillus subtilis and Chromobacterium violaceum. The microorganisms were pre-cultured in LB medium at 30 degree C and a small portion of the pre-cultured was transferred to a culture bottle in which LB medium and 208 Po tracer were contained. The culture was done at 30 degree C with shaking the culture bottle and air passed through a filter was introduced. The Po volatilized was transferred into the trap vials in which scintillator for liquid scintillation counting (LSC) was contained. The Po activity was measured by LSC. All of the microorganisms examined volatilized Po but their ability was quite different each other. Highest ability was observed on Chromobacterium violaceum and then Escherichia coli K-12 followed by Bacillus subtilis, the relative magnitude of the ability was 10 2 , 10, 1, respectively. Chromobacterium violaceum and Escherichia coli K-12 showed high volatility for the first 24 h but Escherichia coli K-12 showed a decrease thereafter. However high volatility was continued on Chromobacterium violaceum during the culture. The low culture temperature suppressed Po volatility, supporting biologically mediated Po emission from the culture.

  9. Neutron diffraction studies of the Na-ion battery electrode materials NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Yahia, H. Ben [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5825 Doha (Qatar); Essehli, R., E-mail: ressehli@qf.org.qa [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5825 Doha (Qatar); Avdeev, M. [Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights NSW 2234 (Australia); Park, J-B.; Sun, Y-K. [Department of Energy Engineering Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Al-Maadeed, M.A. [Center for Advanced Materials (CAM), Qatar University, 2713 Doha (Qatar); Belharouak, I., E-mail: ibelharouak@qf.org.qa [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5825 Doha (Qatar)

    2016-06-15

    The new compounds NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} were synthesized by sol-gel method and their crystal structures were determined by using neutron powder diffraction data. These compounds were characterized by galvanometric cycling and cyclic voltammetry. NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} crystallize with a stuffed α-CrPO{sub 4}-type structure. The structure consists of a 3D-framework made of octahedra and tetrahedra that are sharing corners and/or edges generating channels along [100] and [010], in which the sodium atoms are located. Of significance, in the structures of NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} a statistical disorder Ni{sup 2+}/Cr{sup 3+} was observed on both the 8g and 4a atomic positions, whereas in NaCoCr{sub 2}(PO{sub 4}){sub 3} the statistical disorder Co{sup 2+}/Cr{sup 3+} was only observed on the 8g atomic position. When tested as negative electrode materials, NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} delivered specific capacities of 352, 385, and 368 mA h g{sup −1}, respectively, which attests to the electrochemical activity of sodium in these compounds. - Highlights: • NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} were synthesized by sol-gel method. • The crystal structures were determined by using neutron powder diffraction data. • The three compounds crystallize with a stuffed α-CrPO{sub 4}-type structure. • The three compounds were tested as anodes in sodium-ion batteries. • Relatively high specific capacities were obtained for these compounds.

  10. High-spin yrast states in the 206Po, 208Po, 209At and 210At nuclei

    International Nuclear Information System (INIS)

    Rahkonen, Vesa.

    1980-08-01

    High-spin yrast states in the 206 , 208 Po and 209 , 210 At nuclei have been studied with methods of in-beam γ-ray and conversion-electron spectroscopy and with the (α,3n), (α,4n), (p,2n) and ( 3 He,3n) reactions. Several new high-spin states have been identified up to angular momenta of 18-19 h/2π in these nuclei except in 206 Po where the highest spin was (13 - ). In the course of this work two new isomers with half-lives of 15+-3 ns and 4+-2 μs have been observed at 1689 and 4028 keV in 210 At, which have been interpreted as (10 - ) and 19 + states. The previously-known half-lives of 29+-2 and 680+-75 ns have been established for the three-proton states of Jsup(π)=21/2 - and 29/2 + at 1428 and 2429 keV in 209 At, respectively. A half-life of 1.0+-0.2 μs was measured for the 9 - isomer in 206 Po. Shell-model calculations based on the use of the empirical single- and two-particle interaction energies or of the experimental excitation energies belonging to the relevant one-, two- and three-particle states, have been carried out for these 4-6 particle nuclei. Most of the medium-spin yrast states in 206 Po, 208 Po and 209 At have been successfully described assuming the core for these nuclei being 204 Pb or 206 Pb rather than 208 Pb, and including an extra core polarization interaction described by the P 2 force. (author)

  11. Les poèmes ragusains de Dejan Despic

    Directory of Open Access Journals (Sweden)

    Stefanović Ana

    2005-01-01

    Full Text Available (francuski Les œuvres de Dejan Despic (1930, inspirées par Dubrovnik: Jadranski soneti op. 17 (1951-1954, Dubrovacki divertimento op. 18 (1952 et Dubrovacki kanconijer op. 96 (1989, révèlent, outre leur thème commun, une parenté supplémentaire importante. Elles sont incitées et, d'une manière essentielle, médiatisées par la poésie: soit par les vers de Jovan Ducic (1871-1943, poète du Parnasse et symbolisme serbe, soit par la poésie pétrarquiste ragusaine. Or, ces compositions ne se montrent pas seulement en tant qu` issues de l`inspiration par la poésie sur Dubrovnik, mais aussi d'un conditionnement spirituel plus profond: de l`inspiration poétique du compositeur lui-même par Dubrovnik. C`est le sentiment poétique du monde, en tant que constante de la vision créatrice de Dejan Despic, qui provient de cette inspiration particulière. Ce monde ragusain du compositeur est le monde classique dans une signification universelle du concept, selon la nature même du milieu évoqué. Or, cela n implique pas une monochromie stylistique des compositions considérées. Au contraire, les perspectives musicales de l`impressionnisme, du néoclassicisme, voire, de la néorennaissance, varient ce cadre stylistique général, tout en marquant les traits distincts d'une poétique de composition très individualisée.

  12. LiHo(PO34

    Directory of Open Access Journals (Sweden)

    Mokhtar Férid

    2009-02-01

    Full Text Available Lithium holmium(III polyphosphate(V, LiHo(PO34, belongs to the type I of polyphosphates with general formula ALn(PO34, where A is a monovalent cation and Ln is a trivalent rare earth cation. In the crystal structure, the polyphosphate chains spread along the b-axis direction, with a repeat period of four tetrahedra and 21 internal symmetry. The Li and Ho atoms are both located on twofold rotation axes and are surrounded by four and eight O atoms, leading to a distorted tetrahedral and dodecahedral coordination, respectively. The HoO8 polyhedra are isolated from each other, the closest Ho...Ho distance being 5.570 (1 Å.

  13. LiFePO4 Nanostructures Fabricated from Iron(III) Phosphate (FePO4 x 2H2O) by Hydrothermal Method.

    Science.gov (United States)

    Saji, Viswanathan S; Song, Hyun-Kon

    2015-01-01

    Electrode materials having nanometer scale dimensions are expected to have property enhancements due to enhanced surface area and mass/charge transport kinetics. This is particularly relevant to intrinsically low electronically conductive materials such as lithium iron phosphate (LiFePO4), which is of recent research interest as a high performance intercalation electrode material for Li-ion batteries. Many of the reported works on LiFePO4 synthesis are unattractive either due to the high cost of raw materials or due to the complex synthesis technique. In this direction, synthesis of LiFePO4 directly from inexpensive FePO4 shows promise.The present study reports LiFePO4 nanostructures prepared from iron (III) phosphate (FePO4 x 2H2O) by precipitation-hydrothermal method. The sintered powder was characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Inductive coupled plasma-optical emission spectroscopy (ICP-OES), and Electron microscopy (SEM and TEM). Two synthesis methods, viz. bulk synthesis and anodized aluminum oxide (AAO) template-assisted synthesis are reported. By bulk synthesis, micro-sized particles having peculiar surface nanostructuring were formed at precipitation pH of 6.0 to 7.5 whereas typical nanosized LiFePO4 resulted at pH ≥ 8.0. An in-situ precipitation strategy inside the pores of AAO utilizing the spin coating was utilized for the AAO-template-assisted synthesis. The template with pores filled with the precipitate was subsequently subjected to hydrothermal process and high temperature sintering to fabricate compact rod-like structures.

  14. LiFePO4 mesocrystals for lithium-ion batteries.

    Science.gov (United States)

    Popovic, Jelena; Demir-Cakan, Rezan; Tornow, Julian; Morcrette, Mathieu; Su, Dang Sheng; Schlögl, Robert; Antonietti, Markus; Titirici, Maria-Magdalena

    2011-04-18

    Olivine LiFePO(4) is considered one of the most promising cathode materials for Li-ion batteries. A simple one-step, template-free, low-temperature solvothermal method is developed for the synthesis of urchinlike hierarchical mesocrystals of pristine LiFePO(4) as well as carbon-coated LiFePO(4) composites. Each urchinlike mesocrystal consists of LiFePO(4) sheets self-assembled via a dipolar field in spheres during a solvothermal process under the influence of Cl(-) anions. The obtained primary sheets of LiFePO(4) are single crystalline in nature and can be coated in situ with an amorphous nitrogen-doped carbonaceous layer several nanometers in thickness. To increase the conductivity of the carbon coating, the materials are subjected to further temperature treatment (700 °C) under an inert atmosphere. The lithium storage performance of the pure LiFePO(4) is compared with that of its carbon-coated counterparts. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Moderní počítačové viry

    OpenAIRE

    Malina, Lukáš

    2008-01-01

    Bakalářská práce Moderní počítačové viry se skládá ze dvou hlavních cílů (Analýza počítačových virů a návrh zabezpečení střední počítačové sítě) rozdělených na tři části: Analýza počítačových virů, Vlastní návrh zabezpečení osobního počítače koncového uživatele (Terminálu) a Vlastní návrh zabezpečení střední počítačové sítě. V první části jsou analyzovány metody šíření a infekce, specifické vlastnosti a dopady počítačových virů na osobní počítače. V druhé části je uvedeno řešení zabezpečení o...

  16. Canted antiferromagnetism in KNi3[PO3(F,OH)]2[PO2(OH)2]F2 with a stair-case Kagomé lattice

    Science.gov (United States)

    Liu, Li-Chen; Ren, Wei-Jian; Huang, Ya-Xi; Pan, Yuanming; Mi, Jin-Xiao

    2017-10-01

    A new nickel phosphate KNi3[PO3(F,OH)]2[PO2(OH)2]F2 has been synthesized using a modified hydrothermal method. Structural characterizations show that it adopts a 3D framework structure with 2D layers of Ni octahedra in a stair-case Kagomé lattice. The Ni2 octahedron at the inversion center shares two trans-faces with Ni1 octahedra to form a linear trimer (Ni3O8F6) as the basic structural unit. The Ni-trimers are linked between themselves by sharing F-corners and to [PO3(F,OH)] tetrahedral groups by sharing O-corners to form 2D stair-case Kagomé layers, which are parallel to the (100) plane and are stacked along the a-axis. Successive Kagomé layers are combined together by [PO2(OH)2] tetrahedral groups and interstice cations K+. Magnetic measurements reveal that KNi3[PO3(F,OH)]2[PO2(OH)2]F2 exhibits a canted antiferromagnetic ordering with a ferromagnetic component at low temperatures.

  17. Concentration of Po-210 and Pb-210 in human tissues

    International Nuclear Information System (INIS)

    Zhao Lancai; Takizawa, Y.; Yamamoto, M.

    1990-01-01

    The levels of Pb-210 and Po-210 in human tissues of people in Japan were determined. Various tissue samples were obtained at autopsy from the cadavers of 22 oncologic cases, mainly in Niigata Prefecture in northern Japan during the period of 1986 to 1988. Wet ashing, followed by electrochemical deposition and alpha-ray spectrometry were used to separate and determine the Pb-210 and Po-210 presented. Among the tissues analyzed the highest concentrations of Pb-210 and Po-210 were observed in bone, liver and kidneys: 1.29, 1.69 and 1.22 Bq.kg -1 respectively for Po-210, and 1.27, 0.56 and 0.43 Bq/kg for Pb-210 respectively. The Po-210/Pb-210 ratios in liver and kidney are 3.0 and 2.9 respectively. Po-210/Pb-210 ratios in other tissues are close to one. The total body burden of Pb-210 and Po-210 was found to be approximately 15.8 Bq and 19.1 Bq respectively

  18. Lifetime measurement in {sup 195}Po

    Energy Technology Data Exchange (ETDEWEB)

    Grahn, T.; Page, R.D. [University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); Dewald, A.; Jolie, J.; Melon, B.; Pissulla, T. [Universitaet zu Koeln, Institut fuer Kernphysik, Koeln (Germany); Greenlees, P.T.; Jakobsson, U.; Jones, P.; Julin, R.; Juutinen, S.; Ketelhut, S.; Leino, M.; Nyman, M.; Peura, P.; Rahkila, P.; Saren, J.; Scholey, C.; Sorri, J.; Uusitalo, J. [University of Jyvaeskylae, Department of Physics, P.O. Box 35, Jyvaeskylae (Finland); Kroell, T.; Kruecken, R.; Maierbeck, P. [TU Muenchen, Physik-Department E12, Garching (Germany)

    2009-03-15

    The lifetime of the 17/2{sup +} yrast state in {sup 195}Po has been measured using the recoil distance Doppler-shift technique to be {tau}=43(11) ps. The lifetime was extracted from the singles {gamma}-ray spectra obtained by using the recoil-decay tagging method. The present work provides more information of the coupling schemes, shapes and configuration mixing in neutron-deficient odd-mass Po nuclei. (orig.)

  19. Leaching of 210Po in human saliva from smokeless tobacco

    International Nuclear Information System (INIS)

    Syed, U.F.; Bari, A.; Husain, L.; Husain, L.

    2009-01-01

    Use of smokeless tobacco (SLT) is associated with cancer of the oral cavity. 210 Po, a known carcinogen present in SLT may leach into the saliva when the snuff is held in the mouth. Alpha emission from leached 210 Po can cause oral tissue damage, especially in the presence of non healing ulcers seen frequently in snuff users' mouth. Leaching of 210 Po from SLT in human saliva was determined for six popular US snuff brands. 210 Po was leached into human saliva for 30 min, separated radiochemically and its activity was determined by α-counting. Approximately 2-10% of 210 Po present in SLT was observed to leach. Annual exposure from leached 210 Po, based on average daily consumption of 15 g of SLT, was calculated to range from 1.1 to 3.8 Bq year -1 . (author)

  20. Local structure of vanadium in doped LiFePO4

    International Nuclear Information System (INIS)

    Zhao, Ting; Xu, Wei; Ye, Qing; Cheng, Jie; Zhao, Haifeng; Chu, Wangsheng; Wu, Ziyu; Univ. of Science and Technology of China, Hefei; Xia, Dingguo

    2010-01-01

    LiFePO 4 composites with 5 at.% vanadium doping are prepared by solid state reactions. X-ray absorption fine-structure spectroscopy is used as a novel technique to identify vanadium sites. Both experimental analyses and theoretical simulations show that vanadium does not enter into the LiFePO 4 crystal lattice. When the vanadium concentration is lower then 1 at.%, the dopant remains insoluble. Thus, a single-phase vanadium-doped LiFePO4 cannot be formed and the improved electrochemical properties of vanadium doped LiFePO 4 previously reported cannot be associated with crystal structure changes of the LiFePO 4 via vanadium doping. (orig.)

  1. Synthesis of xLiMnPO4·yLi3V2(PO43/C Nanocomposites for Lithium Ion Batteries Using Tributyl Phosphate as Phosphor Source

    Directory of Open Access Journals (Sweden)

    Yanming Wang

    2017-01-01

    Full Text Available The xLiMnPO4·yLi3V2(PO43/C (x/y = 1 : 0, 12 : 1, 8 : 1, 6 : 1, 4 : 1, 0 : 1 composite cathode materials are synthesized using tributyl phosphate as a novel organic phosphor source via a solid-state reaction process. All obtained xLiMnPO4·yLi3V2(PO43/C composites present similar particles morphology with an average size of ca. 100 nm and low extent agglomeration. The electrochemical performance of pristine LiMnPO4/C can be effectively improved by adding small amounts of Li3V2(PO43 additives. The 4LiMnPO4·Li3V2(PO43/C has a high discharge capacity of 143 mAh g−1 at 0.1 C and keeps its 94% at the end of 100 cycles.

  2. Natural levels of {sup 210}Po in human urine

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Frances, I.; Manjon, G.; Mantero, J.; Diaz, J. [Departament of Applied Phisic II, University of Seville, P.O. Box 41012 Seville (Spain); Garcia-Tenorio, R. [Departament of Applied Phisic II, University of Seville, P.O. Box 41012 Seville (Spain); National Accelerator Centre, P.O. Box 41092 Seville (Spain)

    2014-07-01

    Since the secret agent Alexander Litvinenko was murdered in 2006 by a {sup 210}Po lethal dose, presumably ingested, there is renovated interest on the toxicity of this radionuclide in humans. {sup 210}Po is a radioactive isotope naturally found in nature, mainly incorporated by humans via food and water ingestion, as well as inhaled through its progenitor, the {sup 222}Rn. The total amount of natural {sup 210}Po in the human body can vary from person to person depending on their lifestyle: dietary habits, drinking water source, place of residence (associated with exposure to {sup 222}Rn), etc- and therefore in the concentrations of this element to be found in urine. To analyze the influence of dietary habits on the amount of {sup 210}Po excreted in urine, two volunteers in Seville had a well-defined and time-varying diet for a month, following a daily collection of their urine and determination of the concentrations therein of this radionuclide. The results obtained and the conclusions derived from them form the core of this communication. {sup 210}Po determinations were performed daily in 200 ml aliquots of urine using the technique of high resolution alpha spectrometry. This has involved the application of a single radiochemical method for the concentration and isolation {sup 210}Po, followed by its auto-deposition on copper planchets for proper measure. Daily {sup 210}Po activity concentrations in voluntary urine analyzed during the month of study show high variability with a difference of up to an order of magnitude between maximum and minimum values obtained, and a clear dependence on the diet type followed in the various stages of the experiment. The lowest concentrations obtained are associated with a diet rich in carbohydrates and proteins 'terrestrial' (pork, beef,...), while the highest concentrations were obtained in the final phase of the experiment when the diet was enriched with presence of marine products in fair correspondence with the

  3. Investigation of the Na2(H2PO2)2 - Ba(H2PO2)2 - H2O Water-Salt Ternary System at Room Temperature

    OpenAIRE

    Erge, Hasan; Turan, Hakan; Kul, Ali Riza

    2016-01-01

    Objective: In this study, the solubility, density, conductivity and phase equilibria of the Na2(H2PO2)2-Ba(H2PO2)2-H2O ternary system located in the structure of the Na+, Ba2+, (H2PO2)-//H2O quaternary reciprocal water-salt system were investigated using physicochemical analysis methods. Material and Methods: Riedel-de Haen and Merck salts were used to investigate the solubility and phase equilibria of the Na2(H2PO2)2 -Ba(H2PO2)2-H2O ternary water–salt system at room temperature Res...

  4. PoSSUM: Polar Suborbital Science in the Upper Mesosphere

    Science.gov (United States)

    Reimuller, J. D.; Fritts, D. C.; Thomas, G. E.; Taylor, M. J.; Mitchell, S.; Lehmacher, G. A.; Watchorn, S. R.; Baumgarten, G.; Plane, J. M.

    2013-12-01

    Project PoSSUM (www.projectpossum.org) is a suborbital research project leveraging imaging and remote sensing techniques from Reusable Suborbital Launch Vehicles (rSLVs) to gather critical climate data through use of the PoSSUM Observatory and the PoSSUM Aeronomy Laboratory. An acronym for Polar Suborbital Science in the Upper Mesosphere, PoSSUM grew from the opportunity created by the Noctilucent Cloud Imagery and Tomography Experiment, selected by the NASA Flight Opportunities Program as Experiment 46-S in March 2012. This experiment will employ an rSLV (e.g. the XCOR Lynx Mark II) launched from a high-latitude spaceport (e.g. Eielson AFB, Alaska or Kiruna, Sweden) during a week-long deployment scheduled for July 2015 to address critical questions concerning noctilucent clouds (NLCs) through flights that transition the cloud layer where the clouds will be under direct illumination from the sun. The 2015 Project PoSSUM NLC campaign will use the unique capability of rSLVs to address key under-answered questions pertaining to NLCs. Specifically, PoSSUM will answer: 1) What are the small-scale dynamics of NLCs and what does this tell us about the energy and momentum deposition from the lower atmosphere? 2) What is the seasonal variability of NLCs, mesospheric dynamics, and temperatures? 3) Are structures observed in the OH layer coupled with NLC structures? 4) How do NLCs nucleate? and 5) What is the geometry of NLC particles and how do they stratify? Instrumentation will include video and still-frame visible cameras (PoSSUMCam), infrared cameras, a mesospheric temperatures experiment, a depolarization LiDAR, a mesospheric density and temperatures experiment (MCAT), a mesospheric winds experiment, and a meteoric smoke detector (MASS). The instrument suite used on PoSSUM will mature through subsequent campaigns to develop an integrated, modular laboratory (the ';PoSSUM Observatory') that will provide repeatable, low cost, in-situ NLC and aeronomy observations as well

  5. Removal of FePO4 and Fe3(PO4)2 crystals on the surface of passive fillers in Fe0/GAC reactor using the acclimated bacteria

    International Nuclear Information System (INIS)

    Lai, Bo; Zhou, Yuexi; Yang, Ping; Wang, Juling; Yang, Jinghui; Li, Huiqiang

    2012-01-01

    Highlights: ► Fe 3 (PO 4 ) 2 and FePO 4 crystals would weaken treatment efficiency of Fe 0 /GAC reactor. ► Fe 3 (PO 4 ) 2 and FePO 4 crystals could be removed by the acclimated bacteria. ► FeS and sulfur in the passive film would be removed by the sulfur-oxidizing bacteria. ► Develop a cost-effective bio-regeneration technology for the passive fillers. - Abstract: As past studies presented, there is obvious defect that the fillers in the Fe 0 /GAC reactor begin to be passive after about 60 d continuous running, although the complicated, toxic and refractory ABS resin wastewater can be pretreated efficiently by the Fe 0 /GAC reactor. During the process, the Fe 3 (PO 4 ) 2 and FePO 4 crystals with high density in the passive film are formed by the reaction between PO 4 3− and Fe 2+ /Fe 3+ . Meanwhile, they obstruct the formation of macroscopic galvanic cells between Fe 0 and GAC, which will lower the wastewater treatment efficiency of Fe 0 /GAC reactor. In this study, in order to remove the Fe 3 (PO 4 ) 2 and FePO 4 crystals on the surface of the passive fillers, the bacteria were acclimated in the passive Fe 0 /GAC reactor. According to the results, it can be concluded that the Fe 3 (PO 4 ) 2 and FePO 4 crystals with high density in the passive film could be decomposed or removed by the joint action between the typical propionic acid type fermentation bacteria and sulfate reducing bacteria (SRB), whereas the PO 4 3− ions from the decomposition of the Fe 3 (PO 4 ) 2 and FePO 4 crystals were released into aqueous solution which would be discharged from the passive Fe 0 /GAC reactor. Furthermore, the remained FeS and sulfur (S) in the passive film also can be decomposed or removed easily by the oxidation of the sulfur-oxidizing bacteria. This study provides some theoretical references for the further study of a cost-effective bio-regeneration technology to solve the passive problems of the fillers in the zero-valent iron (ZVI) or Fe 0 /GAC reactor.

  6. Evaluation of uncertainty and detection limits in 210Pb and 210Po measurement in water by alpha spectrometry using 210Po spontaneous deposition onto a silver disk

    International Nuclear Information System (INIS)

    Fernández, Pedro L.; Gómez, José; Ródenas, Carmen

    2012-01-01

    An easy and accurate method for the determination of 210 Pb and 210 Po in water using 210 Po spontaneous deposition onto a silver disk is proposed and assessed for its detection capabilities according to the ISO Guide for the expression of uncertainty in measurement (GUM) and ISO Standard 11929-7 concerning the evaluation of the characteristic limits for ionizing radiation measurements. The method makes no assumption on the initial values of the activity concentrations of 210 Pb, 210 Bi and 210 Po in the sample to be analyzed, and is based on the alpha spectrometric measurement of 210 Po in two different aliquots: the first one measured five weeks after the sampling date to ensure radioactive equilibrium between 210 Pb and 210 Bi and the second after a sufficient time for the ingrowth of 210 Po from 210 Pb to be significant. As shown, for a recommended time interval of seven months between 210 Po measurements, the applicability of the proposed method is limited to water samples with a 226 Ra to 210 Pb activity ratio C Ra /C Pb ≤4, as usual in natural waters. Using sample and background counting times of 24 h and 240 h, respectively, the detection limit of the activity concentration of each radionuclide at the sampling time for a 1 L sample typically varies between 0.7 and 16 mBq L −1 for 210 Pb in water samples with an initial activity of 210 Po in the range 0–200 mBq L −1 , and between 0.6 and 8.5 mBq L −1 for 210 Po in water samples with an initial activity of 210 Pb in the same range. - Highlights: ► 210 Pb and 210 Po measurement in water by 210 Po spontaneous deposition onto silver disks. ► 210 Pb and 210 Po determination based on 210 Po measurement in two different aliquots. ► Evaluation of characteristic limits in radioactivity measurements using ISO 11929-7. ► 10 Pb - 210 Po detection limits decrease with time elapsed between 210 Po measurements.

  7. Diversity in growth and expression pattern of PoHKT1 and PoVHA transporter genes under NaCl stress in Portulaca oleracea taxa

    Directory of Open Access Journals (Sweden)

    El-Bakatoushi R.

    2016-01-01

    Full Text Available Plant growth and the expression of two transporter genes; PoHKT1 and PoVHA transcripts in root and shoot tissues were studied under salt stress of three Portulaca oleracea s.l. taxa. The study showed no significant differences in ratios between root lengths in saline and non-saline treatments of the three taxa, which was correlated with a clear down-regulation of the PoHKT1 transcripts in the root after 150mM NaCl. All measured growth parameters except root length increased in P. oleraceae, decreased in P. granulatostellulata and remain unchanged after 100mM NaCl in P. nitida compared to control under saline conditions. The result was consistent with the type of taxon which had significant effect on the shoot length, number of leaves and dry weight (P< 0.05. All measured growth parameters except root length showed a significant negative correlation with the shoot fold change of PoHKT1 transcripts (r = -0.607, -0.693 and -0.657 respectively. The regulation of PoVHA in root and shoot tissues in the three taxa are significantly different. Under salt stress, both decreased uptake of Na+ into the cytosol by decreasing the expression of PoHKT1 and increased vascular compartmentalization ability of Na+ by inducing the expression of PoVHA seem to work more efficiently in P. oleraceae and P. nitida than in P. granulato-stellulata.

  8. Synthesis of flower-like LiMnPO4/C with precipitated NH4MnPO4·H2O as precursor

    International Nuclear Information System (INIS)

    Liu Jiali; Hu Dongge; Huang Tao; Yu Aishui

    2012-01-01

    Highlights: ► Flower-like NH 4 MnPO 4 ·H 2 O is obtained by novel precipitating method. ► It is used as the precursor to synthesize LiMnPO 4 /C. ► Subsequent heat treatment would not destroy the precursor morphology. ► As-prepared LiMnPO 4 /C showed discharge capacity of 85 mAh/g at 0.05 C. - Abstract: Ammonium magnesium phosphate monohydrate (NH 4 MnPO 4 ·H 2 O) precursor was prepared by a novel precipitating process with manganese citrate complexes as intermediate. The morphology of the precursor observed by Scanning Electron Microscope (SEM) was flower-like which was self-assembled by plate-like particles. Further analysis by X-ray diffraction (XRD) revealed that the lattice of the plate crystal was orientated along (0 1 0) plane. By solid-state reaction of the precursor, with lithium acetate and glucose as carbon source, pure olivine structured LiMnPO 4 /C composite was obtained and meanwhile, the original flower-like morphology could be retained.

  9. poCAMon personal online continuous airmonitor; poCAMon online Personen Aerosolmonitor

    Energy Technology Data Exchange (ETDEWEB)

    Streil, T.; Oeser, V. [SARAD GmbH, Dresden (Germany)

    2015-07-01

    The poCAMon combines a very compact design with a high flow rate and long battery life. Its size and weight are still acceptable for carrying by one person. The unit measures long-lived aerosols as well as short-lived Radon/Thoron daughters by alpha spectroscopy and beta counting. The radioactive aerosols and particles are collected on the surface of a high resolution membrane filter. The alpha and beta decays on the filter are measured by a high-end semiconductor radiation detector (400 mm@). This allows a perfect separation of the different decay products. The increased pump rate (more than 3 l/ min) is suitable for lower detection limits. A sensor measures permanently the pressure drop on the filter in order to recognize an exhausted or perforated filter instantly. With the 3.8 Ah NiMH battery pack the poCAMon achieves an operation time of more than 30 hours. The quality control is a main issue of any radiation measurement. Therefore the poCAMon records a complete alpha spectrum for each measured value. This allows the monitoring of the device's perfect operation in each moment of the measurement. There are options for additional sensors for carbon monoxide and combustible gases as needed in underground mines. All measured data are stored in a 2GB memory card and can be accessed with a PC or laptop via a USB interface. Data transmission and device control can also be done via wireless ZigBee network or via a server for stationary operation with network access. A barometric pressure sensor and a GPS receiver are optional features of the device.

  10. Spectroscopy and measurement of electromagnetic moments in sup(198,200,210)Po

    International Nuclear Information System (INIS)

    Maier, K.H.

    1985-01-01

    The quadrupole coupling constants for the 210 Po Isup(π)=8 + , 11 - , 13 - isomers in Bi have been measured, and Q(11 - )=82(2) fm 2 and Q(13 - )=90(2) fm 2 normalized to Q( 210 Po8 + )=57 fm 2 are deduced. In beam γ-spectroscopy of sup(198,) 200 Po showed the (πh 2 sub(9/2) 8 + ) π(hsub(9/2)isub(13/2) 11 - ) and (visub(13/2) 12 + ) isomers. The B(E2 8 + ->6 + ) and Q(8 + ) in 198 Po to 210 Po are discussed, a sudden drop is found for the B(E2) in 198 Po. The B(E3, 11 - ->8 + ) rises very steeply in the light Po isotopes. (orig.)

  11. Assessment of Po-210 exposure for the Italian population

    International Nuclear Information System (INIS)

    Clemente, G.F.; Renzetti, A.; Santori, G.; Breuer, F.

    1980-01-01

    Most of the natural internal dose of the general population due to alpha particles is associated with 210 Po exposure. The experimental data obtained to evaluate the levels of 210 Po exposure to members of the general Italian population and to some critical population groups exposed to high radon and daughter air concentration are summarized. The 210 Po content was measured in the following: a) daily diets; b) urinary excretions from members of the general population, both non-smokers and smokers; c) urinary excretions from workers in radioactive spas and non-uranium mines; d) teeth and bone samples from the general population. In most samples the content of 210 Pb, was also measured to assess the behaviour of 210 Po in man. A mathematical model fitting the experimental data was developed to describe the metabolism of systemic 210 Po. Four different levels of 210 Po exposure were detected according to the internal burden measured in the considered subjects. The corresponding dose rate to cortical and trabecular bone and soft tissue was evaluated. The values of the mean dose to the skeleton (cortical bone) were found to range from about 70 μGy/year for non-smokers of the general population to about 2 mGy/year for individuals working inside radioactive spas. (H.K.)

  12. Stability of luminescence in LaPO4, LaPO4 :RE(3+) (RE = Dy, Eu) nanophosphors.

    Science.gov (United States)

    Pimpalshende, D M; Dhoble, S J

    2015-03-01

    The property of high refractive index, low solubility in water as well as stability to high temperature variation of lanthanum phosphate (LaPO4 ) proved it was the most effective candidate for the production of display lamps, and plasma display panel devices and sensors. The morphological and nanostructural characteristics play a key role in the working efficiency of the luminescent material. These properties can be controlled by the synthesis method, which we have adopted in this paper. We have prepared LaPO4 nanoparticles at a relatively low temperature (110 ºC) in polyethylene glycol medium by using a wet chemical one-step synthesis. The phase composition and structural properties of the sample have been characterized by X-ray diffraction, Fourier transform infrared, transmission electron microscopy and the luminescent property by photoluminescence and thermoluminescence. The samples were well crystallized and the average crystallite size of 15 nm has been calculated for pure LaPO4 using the Debye-Scherrer equation. The result from heat-treated samples shows the phase combination and morphological structure of the powder depend on the annealing temperature. The heat treatment changes the structure of LaPO4 from cuboid rods to fine grains at about 600 °C. The emission spectrum of LaPO4 shows the broad emission band at 368 nm and shoulder at 465 nm with emission of blue color when monitored at an excitation wavelength at 256 nm. The stability of phosphor has been studied with respect to humidity, temperature, doping, doping concentration, γ-ray exposures, etc. The prepared nanosized phosphors were thermally stable and may be a promising blue phosphor for lighting technology as well as radiation dosimetry. Copyright © 2014 John Wiley & Sons, Ltd.

  13. Towards a construction grammar account of the distributive PO in Polish

    Directory of Open Access Journals (Sweden)

    Adam Przepiórkowski

    2015-11-01

    Full Text Available Towards a construction grammar account of the distributive PO in Polish Polish distributive constructions involving the form po are well known for their syntactic and semantic idiosyncrasy. The aim of this paper is to show that, contrary to the received wisdom, two different lexemes po take part in such constructions: a preposition and an adnumeral operator. This explains some of the idiosyncratic behaviour, namely, the apparent ability of po to combine with different grammatical cases. A preliminary Construction Grammar analysis is proposed which eschews the potential problem of missed generalisations that such a dual account of po might engender.

  14. The onset collectivity in {sup 196}Po

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, L A; Cizewski, J A; Jin, H Q; Henry, R G; Farris, L P [Rutgers--the State Univ., New Brunswick, NJ (United States); Khoo, T L; Carpenter, M P; Janssens, R V.F.; Lauritsen, T [Argonne National Lab., IL (United States); Bearden, I G [Purdue Univ., Lafayette, IN (United States); Ye, D [Notre Dame Univ., IN (United States)

    1992-08-01

    We have studied the in-beam {gamma}-ray spectroscopy of {sup 196}Po, which is the first Po isotope to exhibit collective vibrational structure. The onset of collective motion occurs in this isotope because of the large overlap between valence protons in h{sub 9/2} and valence neutrons in i{sub 13/2} orbitals. (author). 7 refs., 2 tabs., 3 figs.

  15. 210Po in Nevada groundwater and its relation to gross alpha radioactivity

    Science.gov (United States)

    Seiler, R.L.

    2011-01-01

    Polonium-210 (210Po) is a highly toxic alpha emitter that is rarely found in groundwater at activities exceeding 1 pCi/L. 210Po activities in 63 domestic and public-supply wells in Lahontan Valley in Churchill County in northern Nevada, United States, ranged from 0.01 ± 0.005 to 178 ± 16 pCi/L with a median activity of 2.88 pCi/L. Wells with high 210Po activities had low dissolved oxygen concentrations (less than 0.1 mg/L) and commonly had pH greater than 9. Lead-210 activities are low and aqueous 210Po is unsupported by 210Pb, indicating that the 210Po is mobilized from aquifer sediments. The only significant contributors to alpha particle activity in Lahontan Valley groundwater are 234/238U, 222Rn, and 210Po. Radon-222 activities were below 1000 pCi/L and were uncorrelated with 210Po activity. The only applicable drinking water standard for 210Po in the United States is the adjusted gross alpha radioactivity (GAR) standard of 15 pCi/L. 210Po was not volatile in a Nevada well, but volatile 210Po has been reported in a Florida well. Additional information on the volatility of 210Po is needed because GAR is an inappropriate method to screen for volatile radionuclides. About 25% of the samples had 210Po activities that exceed the level associated with a lifetime total cancer risk of 1× 10−4 (1.1 pCi/L) without exceeding the GAR standard. In cases where the 72-h GAR exceeds the uranium activity by more than 5 to 10 pCi/L, an analysis to rule out the presence of 210Po may be justified to protect human health even though the maximum contaminant level for adjusted GAR is not exceeded.

  16. Electric quadruple moments of high-spin isomers in 209Po

    International Nuclear Information System (INIS)

    Ivanov, E.A.; Nicolescu, G.; Plostinaru, D.

    1998-01-01

    The electric quadrupole interaction of the 209 Po (17/2) - and (13/2) - isomers in a Bi single-crystal was measured. The results for the quadrupole moments are connected with studies of isomers in Po isotopes. A two level analysis procedure was employed for the combined data of (17/2) - and (13/2) - isomers. The quadrupole moments of the Po isotopes are of special interest for testing nuclear models because of supposed simple nuclear structure with two protons outside a closed magic number shell. While the g-factors are significant for the predominant few-particle structures often present at high spins, the quadrupole moments are sensitive to additional contributions arising from core deformation effects. A systematic study of quadrupole moments of 12 + isomers in Pb isotopes has indeed demonstrated that the valence neutron effective charge increases as more particle pairs are removed from the 208 Pb core. In the present work, quadrupole coupling constants were measured for the isomers by the time-differential perturbed angular distribution (TDPAD) technique, in the presence of quadrupole interactions from the internal electric field gradient (EFG) in Bi crystal. The experiments were performed using a pulsed deuteron-beam of 13 MeV. The (17/2) - isomer state (T 1/2 = 88 ns) and the (13/2) - isomer state (T 1/2 = 24 ns) were populated and aligned by the 209 Bi(d,2n) reaction. The repetition time of the pulse was 10 μs and the width was around 5 ns (FWHM). The rather low bombardment energy was chosen to reduce population of higher spin isomers and to optimize the population of 209 Po((17/2) - ) and 209 Po((13/2) - ). The 209 Po single crystal target was held at a temperature of 470 K in order to reduce possible radiation damage effects. The experiments have been performed with the c axis of the single crystal at 45 angle and 90 angle to the beam direction. We chose to use a calibration based on isomers with well-understood nuclear structure allowing a reliable

  17. Synthesis and characterization of the novel rare earth orthophosphates Y0.5Er0.5PO4 and Y0.5Yb0.5PO4

    International Nuclear Information System (INIS)

    Schildhammer, Daniel; Petschnig, Lucas L.; Fuhrmann, Gerda; Heymann, Gunter; Schottenberger, Herwig; Huppertz, Hubert; Tribus, Martina

    2016-01-01

    The new mixed rare earth (RE) orthophosphates Y 0.5 Er 0.5 PO 4 and Y 0.5 Yb 0.5 PO 4 were synthesized by a classical solid state reaction in an electrical furnace at 1200 C. As starting materials, the corresponding rare earth oxides and diammonium hydrogen phosphate were used. The powder diffraction analyses revealed that the new compounds Y 0.5 Er 0.5 PO 4 and Y 0.5 Yb 0.5 PO 4 crystallize in a zircon-type structure being isostructural with the rare earth orthophosphate YPO 4 . Y 0.5 Er 0.5 PO 4 and Y 0.5 Yb 0.5 PO 4 crystallize in the tetragonal space group I4 1 /amd (no. 141) with four formula units in the unit cell. The structural parameters based on Rietveld refinements are a = 687.27(2), c = 601.50(2) pm, V = 0.28412(1) nm 3 , R p = 0.0143, and R wp = 0.0186 (all data) for Y 0.5 Er 0.5 PO 4 and a = 684.61(2), c = 599.31(2) pm, V = 0.28089(2) nm 3 , R p = 0.0242, and R wp = 0.0313 (all data) for Y 0.5 Yb 0.5 PO 4 . Furthermore, the structure of Y 0.5 Er 0.5 PO 4 was refined from single-crystal X-ray diffraction data: a = 687.78(5), c = 601.85(4) pm, V = 0.28470(5) nm 3 , R 1 = 0.0165, and wR 2 = 0.0385 (all data). In both compounds, the rare earth metal ions are eightfold coordinated by oxygen atoms, forming two unique interlocking tetrahedra with two individual RE-O distances. The tetrahedral phosphate groups [PO 4 ] 3- are slightly distorted in both compounds. The individual rare earth ions share a common position (Wyckoff site 4a). The presence of two rare earth ions in the structures of the new orthophosphates Y 0.5 Er 0.5 PO 4 and Y 0.5 Yb 0.5 PO 4 was additionally confirmed by single-crystal EDX spectroscopy revealing a ratio of 1:1.

  18. Les poèmes ragusains de Dejan Despic

    OpenAIRE

    Stefanović Ana

    2005-01-01

    (francuski) Les œuvres de Dejan Despic (1930), inspirées par Dubrovnik: Jadranski soneti op. 17 (1951-1954), Dubrovacki divertimento op. 18 (1952) et Dubrovacki kanconijer op. 96 (1989), révèlent, outre leur thème commun, une parenté supplémentaire importante. Elles sont incitées et, d'une manière essentielle, médiatisées par la poésie: soit par les vers de Jovan Ducic (1871-1943), poète du Parnasse et symbolisme serbe, soit par la poésie pétrarquiste ragusaine. Or, ces compositions ne se mon...

  19. Effect of VO43− substitution for PO43− on electrochemical properties of the Li3Fe2(PO4)3 cathode materials

    International Nuclear Information System (INIS)

    Yang, Yonggang; Zhang, Yongguang; Hua, Zhengshen; Wang, Xin; Peng, Huifen; Bakenov, Zhumabay

    2016-01-01

    Graphical abstract: VO 4 3− –substituted Li 3 Fe 2 (PO 4 ) 3 samples were prepared by sol-gel method. The VO 4 3− substitution remarkably improves the rate capability and cycling performance of the Li 3 Fe 2 (PO 4 ) 3 due to improved conductivity and enhanced lithium ion diffusion. - Highlights: • Mixed anion effect was used to improve electrochemical properties of Li 3 Fe 2 (PO 4 ) 3 . • The VO 4 3− substitution improved rate capability and cyclability of Li 3 Fe 2 (PO 4 ) 3 . • The Li 3 Fe 2 (PO 4 ) 2.55 (VO 4 ) 0.45 material shows the excellent electrochemical performance. - Abstract: In this research, VO 4 3− substitution was used to improve electrochemical properties of the Nasicon Li 3 Fe 2 (PO 4 ) 3 cathode material. The VO 4 3− substitution resulted in formation of a homogeneous compound Li 3 Fe 2 (PO 4 ) 3-x (VO 4 ) x in a composition range of x ≤ 0.45; further introduction of VO 4 3− led to precipitation of some other phases. It was shown that the VO 4 3− substituted samples presented discharging capacity higher than that of bare non-substituted Nasicon and the reported Ti 4+ and Mn 2+ doped ones. The Li 3 Fe 2 (PO 4 ) 2.55 (VO 4 ) 0.45 material exhibited excellent cycling stability and rate capability, and retained a capacity of 91.8 mAh g −1 after 60 cycles at 2C charge-discharge rate. This value is one of the highest reported to date for the Li 3 Fe 2 (PO 4 ) 3 compound, and was about 48% higher than that of the latter. The electrochemical performance enhancements for the VO 4 3− substituted samples were attributed to the reduction of charge transfer resistance, increase of electrical conductivity, and fast lithium ion diffusion behavior. Hence, the obtained results proved that the VO 4 3− anion substitution for PO 4 3− is a powerful technique to improve the electrochemical performance of the studied Nasicon compound.

  20. Electroweak Higgs production with HiggsPO at NLO QCD

    Science.gov (United States)

    Greljo, Admir; Isidori, Gino; Lindert, Jonas M.; Marzocca, David; Zhang, Hantian

    2017-12-01

    We present the HiggsPO UFO model for Monte Carlo event generation of electroweak VH and VBF Higgs production processes at NLO in QCD in the formalism of Higgs pseudo-observables (PO). We illustrate the use of this tool by studying the QCD corrections, matched to a parton shower, for several benchmark points in the Higgs PO parameter space. We find that, while being sizable and thus important to be considered in realistic experimental analyses, the QCD higher-order corrections largely factorize. As an additional finding, based on the NLO results, we advocate to consider 2D distributions of the two-jet azimuthal-angle difference and the leading jet p_T for new physics searches in VBF Higgs production. The HiggsPO UFO model is publicly available.

  1. Supervalent doping of LiFePO4 for enhanced electrochemical performance

    Directory of Open Access Journals (Sweden)

    N. V. Kosova

    2015-12-01

    Full Text Available The orthophosphates LiFe0.9M0.1PO4 with the structure of olivine doped with vanadium and titanium were obtained by mechanochemically stimulated solidphase synthesis using high-energy planetary mill AGO-2 and subsequent annealing at 750 °C. It is shown that V- and Ti- ions do not completely substitute for Fe2+ ions in the LiFePO4 structure. The remaining part of these ions involve in the formation of second phase with nashiko-like structure: monoclinic Li3V2(PO43 (space group P21/n and rhombohedral LiTi2(PO43 (space group R-3c. According to TEM, the average size of the particle of nanocomposites is about 100-300 nm. EMF of microanalysis showed that the small particles of secondary phases are segregated at the surface of larger particles of LiFePO4. On the charge-discharge curves of LiFe0.9M0.1PO4 there are plateau corresponding to LiFePO4 and the second phase. The doping with vanadium increases the resistance of the cycling of LiFePO4 and improves its cyclability at high speeds to a greater extent than in the case of doping with titanium.

  2. Unlocking the energy capabilities of micron-sized LiFePO4.

    Science.gov (United States)

    Guo, Limin; Zhang, Yelong; Wang, Jiawei; Ma, Lipo; Ma, Shunchao; Zhang, Yantao; Wang, Erkang; Bi, Yujing; Wang, Deyu; McKee, William C; Xu, Ye; Chen, Jitao; Zhang, Qinghua; Nan, Cewen; Gu, Lin; Bruce, Peter G; Peng, Zhangquan

    2015-08-03

    Utilization of LiFePO4 as a cathode material for Li-ion batteries often requires size nanonization coupled with calcination-based carbon coating to improve its electrochemical performance, which, however, is usually at the expense of tap density and may be environmentally problematic. Here we report the utilization of micron-sized LiFePO4, which has a higher tap density than its nano-sized siblings, by forming a conducting polymer coating on its surface with a greener diazonium chemistry. Specifically, micron-sized LiFePO4 particles have been uniformly coated with a thin polyphenylene film via the spontaneous reaction between LiFePO4 and an aromatic diazonium salt of benzenediazonium tetrafluoroborate. The coated micron-sized LiFePO4, compared with its pristine counterpart, has shown improved electrical conductivity, high rate capability and excellent cyclability when used as a 'carbon additive free' cathode material for rechargeable Li-ion batteries. The bonding mechanism of polyphenylene to LiFePO4/FePO4 has been understood with density functional theory calculations.

  3. Hydrothermal synthesis of LiFePO4 nanorods composed of ...

    Indian Academy of Sciences (India)

    Administrator

    LiFePO4 nanorods composed of nanoparticles were synthesized from ... olivine structure; belongs to Pnma space group. ... LiFePO4 has one-dimensional (1D) channel along the ... phases of LiFePO4 ... Among the various synthesis techniques available, the .... Prosini P, Lisi M, Zane D and Pasquali M 2002 Solid State. Ion.

  4. New equations to calculate temperature correction factors for PO2 in human blood.

    Science.gov (United States)

    Inaba, H; Ohwada, T; Sato, J; Mizuguchi, T; Hirasawa, H

    1986-01-01

    Effects of hemoglobin concentration (Hb), pH, and body temperature (T) on the relationships between delta log PO2/delta T and PO2 were studied by means of a mathematical model using a Newton-Raphson iteration method. The functions between delta log PO2/delta T and PO2 were affected by the above three factors. New equations considering the effects of Hb, pH, and T were proposed by modifying the equation reported by Severinghaus: delta log PO2/delta T = (L +(U-L)/(A(vPO237)B + 1))(10(-2) where U = 3.15-0.45(7.4-pH37) L = 0.68-0.09(7.4-pH37) A = 5.86(exp10(0.074(T)-0.294(7.4-pH37)-11))((Hb)0.913) B = 6.33(exp10(-0.0051(T)))((Hb)-0.113) + 0.24(7.4-pH37) and vPO237 is virtual PO237 which may exist when PO237 is corrected to standard conditions (pH = 7.4, BE = 0) by the following equations: vPO237 = PO237(exp10(fB(7.4-pH37)-0.0013(BE))) fB = (PO237/26.6)0.08-1.52 where fB is the Bohr factor. The above equations provided values of delta log PO2/delta T which fit closely to those obtained by the complex iteration method with maximum differences of less than 1.3 X 10(-3) at T = 27, indicating that maximum % errors for PO2 at T (PO2T) are less than 3.0% at T = 27 and that our equations can be applied over a wide range of Hb, pH37 and T.

  5. Biological reduction-deposition and luminescent properties of nanostructured CePO{sub 4}@NaCe(SO{sub 4}){sub 2}(H{sub 2}O) and CePO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiaoniu [School of Materials Science and Engineering, Southeast University, Nanjing 211189 (China); Research Institute of Green Construction Materials, Southeast University, Nanjing 211189 (China); Qian, Chunxiang, E-mail: cxqian@seu.edu.cn [School of Materials Science and Engineering, Southeast University, Nanjing 211189 (China); Research Institute of Green Construction Materials, Southeast University, Nanjing 211189 (China)

    2016-03-01

    Nano-sized CePO{sub 4}@NaCe(SO{sub 4}){sub 2}(H{sub 2}O) and CePO{sub 4} with hexagonal phase have been prepared by simply varying the reactant P/Ce molar ratio in bacterial liquid. The phase composition of two samples was checked via Fourier transform infrared spectroscopy (FTIR), energy dispersive analysis of X-rays (EDS) and X-ray diffraction (XRD) analyses, displaying the presence of CePO{sub 4}@NaCe(SO{sub 4}){sub 2}(H{sub 2}O) and CePO{sub 4} with average crystallite size are 32.34 and 15.61 nm, respectively. The scanning electron microscopy (SEM) images show that nano-clusters and sphere-like in shape with a narrow diameter distribution were observed in two samples. The transmission electron microscopy (TEM) photographs further indicate obtained CePO{sub 4}@NaCe(SO{sub 4}){sub 2}(H{sub 2}O) and CePO{sub 4} nanoparticles correspond to nanosheets and nanorods, respectively. The emission spectra of CePO{sub 4}@NaCe(SO{sub 4}){sub 2}(H{sub 2}O) and CePO{sub 4} display a broad band of 300–380 nm range with the strongest emission at 342 nm in the violet region. - Highlights: • A new method was found to synthesize CePO{sub 4}@NaCe(SO{sub 4}){sub 2}(H{sub 2}O) and CePO{sub 4} nanoparticles. • CePO{sub 4}@NaCe(SO{sub 4}){sub 2}(H{sub 2}O) nanoparticles have good luminescent properties. • Size and luminescent properties of two samples have been studied and compared.

  6. Po-210 distribution in uranium-mill circuits

    International Nuclear Information System (INIS)

    McKlveen, J.W.; Hubele, N.D.; McDowell, W.J.; Case, G.N.

    1983-01-01

    Greater than 99% of all incoming Po-210 reports to the tailing piles for both the acid and the alkaline leach uranium circuits. Leached Po-210 may be carried along on small particles rather than dissolved in solution. There does not appear to be any radiologically significant buildup or accumulation in the acid leach circuit, but there are noteworthy amounts in the molybdenum recovery solution

  7. Degradation Studies on LiFePO4 cathode

    DEFF Research Database (Denmark)

    Scipioni, Roberto; Jørgensen, Peter Stanley; Hjelm, Johan

    2015-01-01

    In this paper we examine a laboratory LiFePO4 (LFP) cathode and propose a simple model that predicts the electrode capacity as function of C-rate, number of cycles and calendar time. Microcracks were found in Li1-xFePO4 particles in a degraded LFP electrode and low-acceleration voltage (1 kV) FIB....../SEM analysis allowed us to obtain phase contrast between FePO4 and LiFePO4. The evolution of micro-cracks is expected to increase the concentration of LFP particles which are not electronically accessible and thus cause a loss in capacity....

  8. Doticaj moderne kozmologije i religije: poimanje početka svemira

    OpenAIRE

    Petković, Tomislav

    2007-01-01

    Ujedinjenje velikih teorija fizike − teorije relativnosti, kvantne mehanike i fizike svemira i čestica − ostaje snom fizike i filozofije znanosti i na početku 21. stoljeća. Sve se one u pogledu konačnih zakona svemira (teorija svega) slažu da je početak bio, te da su konačni zakoni oni koji su već vladali u početku evolucije svemira. Početak svemira podrazumijeva njegovo stvaranje i nužno upućuje na Stvoritelja−religijskog Boga, na uspostavljanje mosta između moderne kozmologije i religije. U...

  9. Structural studies of the high-temperature modifications of sodium and silver orthophosphates, II-Na3PO4 and II-Ag3PO4, and of the low-temperature form I-Ag3PO4

    International Nuclear Information System (INIS)

    Newsam, J.M.; Cheetham, A.K.; Tofield, B.C.

    1980-01-01

    The crystal structures of the high-temperature modifications of sodium and silver orthophosphates have been determined using powder neutron diffraction (PND) data. II-Na 3 PO 4 adopts the space group Fm3m with a = 7.512(3) A at 400 0 C. The PO 4 3- group is centred around the origin, but it shows high orientational disorder. The sodium ions occupy the (1/4, 1/4, 1/4) and (1/2, 1/2, 1/2) sites. II-Ag 3 PO 4 , at 650 0 C, is similar with a = 7.722 (5) A. The structure of I-Ag 3 PO 4 at room temperature (P4 - 3n, a = 6.0095 (6) A) has been re-examined by single-crystal X-ray diffraction. The derived model, with R = 0.019 for 116 independent reflections, is in agreement with the latest work reported in the literature. The structure of I-Ag 3 PO 4 at 375 0 C, as determined by PND, has a = 6.061(1) A, and displays no gross modifications from that observed at 25 0 C, although the anisotropic nature of the silver sites is markedly more pronounced at this higher temperature. The cation mobility is discussed in relation to the high-temperature structures. (Auth.)

  10. Synthesis and electrochemical properties of xLiMn0.9Fe0.1PO4·yLi3V2(PO4)3/C composite cathode materials for lithium–ion batteries

    International Nuclear Information System (INIS)

    Wu, Ling; Lu, JiaJia; Wei, Gui; Wang, Pengfei; Ding, Hao; Zheng, Junwei; Li, Xiaowei; Zhong, Shengkui

    2014-01-01

    Highlights: • xLiMn 0.9 Fe 0.1 PO4·yLi 3 V 2 (PO 4 ) 3 /C composites are prepared by a solid-state method. • The addition of Li 3 V 2 (PO 4 ) 3 can improve the properties of LiMn 0.9 Fe 0.1 PO 4 . • Mutual doping occurrs between the LiMn 0.9 Fe 0.1 PO 4 and Li 3 V 2 (PO 4 ) 3 phases. • 5LiMn 0.9 Fe 0.1 PO 4 ·Li 3 V 2 (PO 4 ) 3 /C shows the best electrochemical properties. - Abstract: The xLiMn 0.9 Fe 0.1 PO 4 ·yLi 3 V 2 (PO 4 ) 3 /C (x:y=1:0, 9:1 5:1, 3:1, 1:1 and 0:1) cathode materials are synthesized by a ball–milling and post–calcination method. XRD results reveal that the xLiMn 0.9 Fe 0.1 PO 4 ·yLi 3 V 2 (PO 4 ) 3 /C (x,y≠0) composites are composed of LiMn 0.9 Fe 0.1 PO 4 and Li 3 V 2 (PO 4 ) 3 phases, and no impurities are detected. In LiMn 0.9 Fe 0.1 PO 4 –Li 3 V 2 (PO 4 ) 3 system, most of the manganese, iron and vanadium elements in the raw materials tend to form the two major phases, and only small amounts of V, Mn and Fe as dopants enter into the lattice of LiMn 0.9 Fe 0.1 PO 4 and Li 3 V 2 (PO 4 ) 3 . Electrochemical tests show that the xLiMn 0.9 Fe 0.1 PO 4 ·yLi 3 V 2 (PO 4 ) 3 /C (x,y≠0) composites exhibit much better performance than the single LiMn 0.9 Fe 0.1 PO 4 /C. Among the samples, 5LiMn 0.9 Fe 0.1 PO 4 ·Li 3 V 2 (PO 4 ) 3 /C shows the best electrochemical performance. The sample delivers the specific capacities of 158.1, 140.7 and 100.2 mAh g −1 at 0.05, 1 and 4 C rates in the potential range of 2.5–4.5 V, and exhibits very long and flat discharge plateau around 4.0 V up to 1 C rate. The sample also shows good cycling performance at various C–rates

  11. Separation and electrodeposited of {sup 210} Po; Separacion y electrodeposito de {sup 210} Po

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez R, E.; Iturbe G, J.L

    1991-12-15

    Presently work it was determined the selective separation of the {sup 210} Po that is in an uraniferous mineral, by means of acid leaching of the mineral and the purification was carried out by means of partition chromatography whose stationary phase is 2-ethylhexyl phosphoric acid (D{sub 2}EHPA), it has been possible to isolate the {sup 210} Po of the rest of the radioactive elements that conform the family 4 N{sup +2}, the optimal elutriation conditions of this element were settled down of manner of not dragging other radioelements. Another of the achievements presented in this communication has been the electrodeposition of this element has more than enough stainless steel discs with a superior yield to 95%. (Author)

  12. Low collectivity of the first 2+ states of 212,210Po

    Science.gov (United States)

    Kocheva, D.; Rainovski, G.; Jolie, J.; Pietralla, N.; Blazhev, A.; Astier, A.; Altenkirch, R.; Bast, M.; Beckers, M.; Ansari, S.; Braunroth, Th.; Cappellazzo, M.; Cortés, M. L.; Dewald, A.; Diel, F.; Djongolov, M.; Fransen, C.; Gladnishki, K.; Goldkuhle, A.; Hennig, A.; Karayonchev, V.; Keatings, J. M.; Kluge, E.; Kröll, Th.; Litzinger, J.; Moschner, K.; Müller-Gatermann, C.; Petkov, P.; Rudigier, M.; Scheck, M.; Spagnoletti, P.; Scholz, Ph.; Schmidt, T.; Spieker, M.; Stahl, C.; Stegmann, R.; Stolz, A.; Vogt, A.; Stoyanova, M.; Thöle, P.; Warr, N.; Werner, V.; Witt, W.; Wölk, D.; Zamora, J. C.; Zell, K. O.; Van Isacker, P.; Ponomarev, V. Yu.

    2018-05-01

    The lifetimes of the first 2+ excited states of 212,210Po were measured in two transfer reactions 208Pb(12C,8Be)212Po and 208Pb(12C,10Be)210Po by the Recoil Distance Doppler Shift (RDDS) method and by the Doppler Shift Attenuation method (DSAM), respectively. The derived absolute B(E2) values of 2.6(3) W.u. for 212Po and 1.83(28) W.u. for 210Po indicate low collectivity. It is shown that the properties of the yrast {2}1+, {4}1+, {6}1+ and {8}1+ states in both nuclei cannot be described consistently in the framework of nuclear shell models. It is also demonstrated in the case of 210Po that Quasi-particle Phonon Model (QPM) calculations cannot overcome this problem thus indicating the existence of a peculiarity which is neglected in both theoretical approaches.

  13. Investigations of the potential bioavailability of 210Po in some foodstuffs

    International Nuclear Information System (INIS)

    Bulman, Robert A.; Ewers, Leon W.; Matsumoto, Kiyoshi

    1995-01-01

    Extraction of 210 Po from lamb's liver, pig's kidneys, mussel flesh and brown crabmeat with a series of solvent systems has been used to gain some insight into the uncertainty about the gastrointestinal absorption factor for Po incorporated into foodstuffs. By extracting the tissues with diethyldithiocarbamate dissolved in chloroform, and also in methanol, it has been shown that 210 Po is more effectively extracted from lamb's liver and crabmeat than it is from each of the other tissues. A similar pattern of extractability is also evident for aqueous solutions of citric acid on crabmeat and mussel flesh. Of particular note is the low extractability by dimethylsulphoxide (3%) of 210 Po in mussel flesh as opposed to 24% extractability of 210 Po from crabmeat. 210 Po-binding macromolecules of about 10 kDa have been released from crabmeat and mussel flesh by digestion with pepsin

  14. A radiochemical procedure for the determination of Po-210 in environmental samples

    International Nuclear Information System (INIS)

    Godoy, J.M.; Schuettelkopf, H.

    1980-07-01

    A radiochemical procedure for the determination of Po-210 in environmental samples was developed. Soil, sediments, filter materials, plants, water and food samples can be analyzed for Po-210. Wet ashing is achieved with HNO 3 + H 2 O 2 or HCl + HNO 3 . To separate disturbing substances, a coprecipitation with Te is used for sample materials containing silica. Po-210 deposition from HCl solution on Ag platelets with other sample materials is possible directly. Deposited Po-210 is counted by α-spectrometry. For chemical yield determination Po-208 is added, yields range between 60% and 100%. A lower detection limit of about 0,002 pCi Po-210/sample is achievable. (orig./HP) [de

  15. Accumulation of 210Po by benthic marine algae

    International Nuclear Information System (INIS)

    Gouvea, R.C.; Branco, M.E.C.; Santos, P.L.

    1988-01-01

    The accumulation of polonium 210 Po by various species of benthic marine seaweeds collected from 4 different points on the coast of Rio de Janeiro, showed variations by species and algal groups. The highest value found was in red alga, Plocamium brasiliensis followed by other organisms of the same group. In the group of the brown alga, the specie Sargassum stenophylum was outstanding. The Chlorophyta presented the lowest content of 210 Po. The algae collected in open sea, revealed greater concentration factors of 210 Po than the same species living in bays. The siliceous residue remaining after mineralization of the algae did not interfere with the detection of polonium. (author)

  16. Electroweak Higgs production with HiggsPO at NLO QCD

    International Nuclear Information System (INIS)

    Greljo, Admir; Isidori, Gino; Zhang, Hantian; Lindert, Jonas M.; Marzocca, David

    2017-01-01

    We present the HiggsPO UFO model for Monte Carlo event generation of electroweak VH and VBF Higgs production processes at NLO in QCD in the formalism of Higgs pseudo-observables (PO). We illustrate the use of this tool by studying the QCD corrections, matched to a parton shower, for several benchmark points in the Higgs PO parameter space. We find that, while being sizable and thus important to be considered in realistic experimental analyses, the QCD higher-order corrections largely factorize. As an additional finding, based on the NLO results, we advocate to consider 2D distributions of the two-jet azimuthal-angle difference and the leading jet p T for new physics searches in VBF Higgs production. The HiggsPO UFO model is publicly available. (orig.)

  17. Electroweak Higgs production with HiggsPO at NLO QCD

    Energy Technology Data Exchange (ETDEWEB)

    Greljo, Admir [Universitaet Zuerich, Physik-Institut, Zurich (Switzerland); Johannes Gutenberg-Universitaet Mainz, PRISMA Cluster of Excellence and Mainz Institute for Theoretical Physics, Mainz (Germany); University of Sarajevo, Faculty of Science, Sarajevo (Bosnia and Herzegovina); Isidori, Gino; Zhang, Hantian [Universitaet Zuerich, Physik-Institut, Zurich (Switzerland); Lindert, Jonas M. [Durham University, Department of Physics, Institute for Particle Physics Phenomenology, Durham (United Kingdom); Marzocca, David [Universitaet Zuerich, Physik-Institut, Zurich (Switzerland); INFN, Sezione di Trieste(Italy); SISSA, Trieste (Italy)

    2017-12-15

    We present the HiggsPO UFO model for Monte Carlo event generation of electroweak VH and VBF Higgs production processes at NLO in QCD in the formalism of Higgs pseudo-observables (PO). We illustrate the use of this tool by studying the QCD corrections, matched to a parton shower, for several benchmark points in the Higgs PO parameter space. We find that, while being sizable and thus important to be considered in realistic experimental analyses, the QCD higher-order corrections largely factorize. As an additional finding, based on the NLO results, we advocate to consider 2D distributions of the two-jet azimuthal-angle difference and the leading jet p{sub T} for new physics searches in VBF Higgs production. The HiggsPO UFO model is publicly available. (orig.)

  18. Studies of the balance 210Pb - 210Po in glasses; Estudios del equilibrio 210Pb - 210Po en vidrios

    Energy Technology Data Exchange (ETDEWEB)

    Torre Pérez, J. de la; Martín Sánchez, A.; Ruano Sánchez, A.B.

    2014-07-01

    Retrospective dosimetry requires measurement methods allowing the determination of Radon concentration in the past. One of the such methods is based on the direct measurement of 210Po implanted on the surface of objects, whose activity concentration (Bq/m2), is directly related to the cumulative exposure due to the concentration of 222Rn (Bq/m3) for long time. These determinations are possible taking into consideration the equilibrium between 210Po (T1/2 = 138.378 days) and its parent 210Pb (T1/2 = 22.3 years), being both radionuclides from the 222Rn progeny. In previous works about the determination of the conversion factor (ratio between the concentration of 210Po in objects and the retrospective 222Rn concentration in air), Corresponding equilibria between descendants were assumed. In this work, an experimental study about the equilibrium 210Pb - 210Po in glasses, which were previously exposed to some radon concentrations, has been performed. Two scenarios were studied: a place with, and another place without, continuous cumulative 222Rn concentration. Results were compared with those reached by theoretical calculations from the (Bateman) activity evolution equations. [Spanish] La dosimetría retrospectiva requiere métodos de medida que permitan la determinación de la concentración de radón en el pasado. Uno de estos métodos está basado en la medida directa del 210Po implantado sobre la superficie de objetos, cuya concentración de actividad (Bq/m2), está directamente relacionada con la exposición acumulativa debida a la concentración de 222Rn (Bq/m3) durante largos períodos de tiempo. Estas determinaciones son posibles gracias al equilibrio entre el 210Po (T1/2 = 138,378 días) y su progenitor, el 210Pb (T1/2 = 22,3 años), siendo ambos radionúclidos descendientes del 222Rn. En trabajos anteriores sobre la determinación del factor de conversión (relación entre la concentración de 210Po en los objetos y la concentración de 222Rn retrospectivo en

  19. LiFePO4/C nanocomposites for lithium-ion batteries

    Science.gov (United States)

    Eftekhari, Ali

    2017-03-01

    LiFePO4, as the most famous member of the family of olivine-type lithium transition metal phosphates, is one of the promising candidates for the cathodes of lithium-ion batteries. However, its battery performance is limited by its low electrical conductivity and slow Li solid-state diffusion. Various methods have been attempted to improve the battery performance of lithium iron phosphate. Among them, compositing the LiFePO4 with carbon nanomaterials seems to be the most promising, as it is facile and efficient. Carbon nanomaterials usually serve as a conductive agent to improve the electrical conductivity while increasing the material porosity in which the solid-state diffusion distances are significantly shortened. Owing to the popularity of various carbonaceous nanomaterials, there is no straightforward line of research for comparing the LiFePO4/C nanocomposites. This review aims to provide a general perspective based on the research achievements reported in the literature. While surveying the research findings reported in the literature, controversial issues are also discussed. The possible contribution of pseudocapacitance as a result of functionalized carbon or LiFePO4 lattice defects is described, since from a practical perspective, a LiFePO4/C electrode can be considered as a supercapacitor at high C rates (with a specific capacitance as large as 200 F g-1). The Li diffusion in LiFePO4 has not been well understood yet; while the Li diffusion within the LiFePO4 lattice seems to be quite fast, the peculiar interfacial electrochemistry of LiFePO4 slows down the diffusion within the entire electrode by a few orders of magnitude.

  20. Relational Aggression in Children with Preschool Onset (PO) Psychiatric Disorders

    Science.gov (United States)

    Belden, Andy C.; Gaffrey, Michael S.; Luby, Joan L.

    2012-01-01

    Objective The role of preschool onset (PO) psychiatric disorders as correlates and/or risk factors for relational aggression during kindergarten or 1st grade was tested in a sample of N = 146 preschool-age children (3 to 5.11). Method Axis-I diagnoses and symptom scores were derived using the Preschool Age Psychiatric Assessment. Children’s roles in relational aggression as aggressor, victim, aggressive-victim, or non-aggressor/non-victim were determined at preschool and again 24 months later at elementary school entry. Results Preschoolers diagnosed with PO-psychiatric disorders were 3 times as likely as the healthy preschoolers to be classified aggressors, victims, or aggressive-victims. Children diagnosed with PO-disruptive, depressive, and/or anxiety disorders were at least 6 times as likely as children without PO-psychiatric disorders to become aggressive-victims during elementary school after covarying for other key risk factors. Conclusions Findings suggested that PO-psychiatric disorders differentiated preschool and school-age children’s roles in relational aggression based on teacher-report. Recommendations for future research and preventative intervention aimed at minimizing the development of relational aggression in early childhood by identifying and targeting PO-psychiatric disorders are made. PMID:22917202

  1. Ion conductivity and phase transitions in the Na3Sc2(PO4)3 - NaGe2(PO4)3 system

    International Nuclear Information System (INIS)

    Nogaj, A.S.

    2002-01-01

    Influence of heteropolyvalent substitution on dipole ordering of sodium-scandium phosphate, as well as on ion conductivity and phase transitions in the system Na 3 Sc 2 (PO 4 ) 3 - NaGe 2 (PO 4 ) 3 , was studied using the methods of solid phase synthesis, X-ray diffraction, laser spectroscopy and measurement of electric conductivity. Boundaries of the dipole-ordered and superionic phases existence ranges in the given system were identified. It is shown that expansion of the dipole-ordered phase existence range with increase in substituent cation concentration is characteristic of the phase on the basis of α-Na 3 Sc 2 (PO 4 ) 3 [ru

  2. Synthesis of spherical LiMnPO4/C composite microparticles

    International Nuclear Information System (INIS)

    Bakenov, Zhumabay; Taniguchi, Izumi

    2011-01-01

    Highlights: → We could prepare LiMnPO 4 /C composites by a novel preparation method. → The LiMnPO 4 /C composites were spherical particles with a mean diameter of 3.65 μm. → The LiMnPO 4 /C composite cathode exhibited 112 mAh g -1 at 0.05 C. → It also showed a good rate capability up to 5 C at room temperature and 55 o C. -- Abstract: Spherical LiMnPO 4 /C composite microparticles were prepared by a combination of spray pyrolysis and spray drying followed by heat treatment and examined as a cathode material for lithium batteries. The structure, morphology and electrochemical performance of the resulting spherical LiMnPO 4 /C microparticles were characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electronic microscopy and standard electrochemical techniques. The final sample was identified as a single phase orthorhombic structure of LiMnPO 4 and spherical powders with a geometric mean diameter of 3.65 μm and a geometric standard deviation of 1.34. The electrochemical cells contained the spherical LiMnPO 4 /C microparticles exhibited first discharge capacities of 112 and 130 mAh g -1 at 0.05 C at room temperature and 55 o C, respectively. These also showed a good rate capability up to 5 C at room temperature and 55 o C.

  3. PoET: Polarimeters for Energetic Transients

    Science.gov (United States)

    McConnell, Mark; Barthelmy, Scott; Hill, Joanne

    2008-01-01

    This presentation focuses on PoET (Polarimeters for Energetic Transients): a Small Explorer mission concept proposed to NASA in January 2008. The principal scientific goal of POET is to measure GRB polarization between 2 and 500 keV. The payload consists of two wide FoV instruments: a Low Energy Polarimeter (LEP) capable of polarization measurements in the energy range from 2-15 keV and a high energy polarimeter (Gamma-Ray Polarimeter Experiment - GRAPE) that will measure polarization in the 60-500 keV energy range. Spectra will be measured from 2 keV up to 1 MeV. The PoET spacecraft provides a zenith-pointed platform for maximizing the exposure to deep space. Spacecraft rotation will provide a means of effectively dealing with systematics in the polarization response. PoET will provide sufficient sensitivity and sky coverage to measure statistically significant polarization for up to 100 GRBs in a two-year mission. Polarization data will also be obtained for solar flares, pulsars and other sources of astronomical interest.

  4. 210Po radiation dose due to cigarette smoking

    International Nuclear Information System (INIS)

    Godwin, Wesley S.; Subha, Vincila R.; Feroz, Khan M.

    2010-01-01

    The level of 210 Po in eight brands of cigarettes and four brands of bidis popular in and around Nagercoil town was determined to evaluate the annual effective dose. The 210 Po activity in a full cigarette ranged from 32.8±3.6 to 68.4±5.9 mBq and from 34.3±3.5 to 62.9±5.8 mBq in a bidi. In tobacco, the highest 210 Po content was recorded in the brand C4 (23.0±1.2 mBq) whereas for bidis it was the highest in the brand B2 (21.1±1.1 mBq). The activity in mainstream varied from 15.2±0.75 to 36.8±2.1 mBq in a cigarette and from 20.7±3.1 to 39.8±4.0 mBq in a bidi. With regard to 210 Po activity concentration, not much specificity was noted with respect to the tobacco brand. The data showed a relatively wide range of activity concentration of 210 Po in the different cigarette/bidi brands and even within the same brand. The bidis showed a higher activity when compared to cigarettes. The popular brands concentrated more activity than the fine brands. Smokers who smoke one pack (10 cigarettes/bidis) per day may inhale about 100-300 mBq d -1 (0.1-0.3 Bq d -1 ) of 210 Po. In this study, radiation dose values in the range of 153.5-372.9 μSv Y - '1 from cigarettes and from 209.2 to 402.7 μSvY -1 from bidis was estimated for the whole body. (author)

  5. Infrared-active optical phonons in LiFePO4 single crystals

    Science.gov (United States)

    Stanislavchuk, T. N.; Middlemiss, D. S.; Syzdek, J. S.; Janssen, Y.; Basistyy, R.; Sirenko, A. A.; Khalifah, P. G.; Grey, C. P.; Kostecki, R.

    2017-07-01

    Infrared-active optical phonons were studied in olivine LiFePO4 oriented single crystals by means of both rotating analyzer and rotating compensator spectroscopic ellipsometry in the spectral range between 50 and 1400 cm-1. The eigenfrequencies, oscillator strengths, and broadenings of the phonon modes were determined from fits of the anisotropic harmonic oscillator model to the data. Optical phonons in a heterosite FePO4 crystal were measured from the delithiated ab-surface of the LiFePO4 crystal and compared with the phonon modes of the latter. Good agreement was found between experimental data and the results of solid-state hybrid density functional theory calculations for the phonon modes in both LiFePO4 and FePO4.

  6. Temporal annual changes of 210Po concentrations in coastal seawater at Kyushu Island

    International Nuclear Information System (INIS)

    Tolmachyov, S.; Maeda, Y.; Momoshima, N.

    2001-01-01

    Polonium-210 ( 210 Po, T 1/2 =138.4 d) arises from the decay of 210 Pb (T 1/2 =22.3 yr) via intermediary 210 Bi (T 1/2 =5.03 d). Virtually, all of 210 Po in seawater is originated by in situ decay of 210 Pb, which in turn originated due to in situ decay of 226 Ra, and decay of 222 Rn in the sea and in the atmosphere followed by deposition. In seawater, 210 Po is considered an insoluble element, therefore the concentration of dissolved 210 Po is very low. The concentration levels of 210 Po in marine environmental samples are well documented, however, scanty information is available about long-scale 210 Po behavior in open oceans and/or coastal seawater. Few studies have quantified temporal variation of 210 Po concentrations with relation to environmental parameters and seasonality. Nevertheless, seasonal detail allows us to make inferences about what geochemical parameters can effected on 210 Po behavior in the marine environment that will obviously improve our present understanding of the rates and mechanisms of 210 Po scavenging from seawater column. This paper presents the results of annual observation of 210 Po concentration in the coastal seawater at Kyushu Island (Japan). Besides the 210 Po concentrations, concentration of Chlorophyll-a (Chl-a), which is generally used as an indicator of plankton activity, fluctuations of loaded suspended particulate matter (SPM) concentration (C p ) and monthly rainfall collected at the place close to the sampling area were examined to confirm if their behavior mirrors that of 210 Po. (author)

  7. Pt/AlPO{sub 4} nanocomposite thin-film electrodes for ethanol electrooxidation

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Yuhong; Kang, Joonhyeon; Nam, Seunghoon; Byun, Sujin [WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of); Park, Byungwoo, E-mail: byungwoo@snu.ac.kr [WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 151-744 (Korea, Republic of)

    2012-07-16

    The enhanced catalytic properties toward ethanol electrooxidation on Pt/AlPO{sub 4} nanocomposite thin-film electrodes were investigated. The Pt/AlPO{sub 4} nanocomposites with various Al/Pt ratios (0.27, 0.57, and 0.96) were fabricated by a co-sputtering method. All of the Pt/AlPO{sub 4} nanocomposites showed a negative shift in the onset potential and a higher current density than those of pure Pt electrode for the electrooxidation of ethanol. Among the various Pt/AlPO{sub 4} nanocomposite thin-film electrodes, the electrode with an atomic ratio of Al to Pt of 0.57 showed the highest electrocatalytic activity for ethanol electrooxidation. The activation enthalpy for the optimum Pt/AlPO{sub 4} nanocomposite was approximately 0.05 eV lower than that of pure Pt. It is believed that the enhancement in catalytic activity is due to the electron-rich Pt resulting from the Fermi-energy difference between Pt and AlPO{sub 4}. - Highlights: Black-Right-Pointing-Pointer The enhanced ethanol electrooxidation on Pt/AlPO{sub 4} nanocomposites is investigated. Black-Right-Pointing-Pointer The Pt/AlPO{sub 4} exhibits higher current density and lower onset potential than pure Pt. Black-Right-Pointing-Pointer The activation enthalpy for optimum Pt/AlPO{sub 4} electrode is {approx}0.05 eV lower than pure Pt. Black-Right-Pointing-Pointer XPS shows electron-rich Pt due to Fermi-energy difference between Pt and AlPO{sub 4}.

  8. Spirit Pluralisme dalam Klenteng Sam Po Kong Semarang

    Directory of Open Access Journals (Sweden)

    Edi Nurwahyu Julianto

    2015-07-01

    Full Text Available Klenteng Sam Po Kong has very deep meaning as a symbol of multi cultural; multi ethnic and multi religious. Klenteng Sam Po Kong has a different function, not only used by people with background religious Tri Dharma (Budha, Tao and Konghuchu, but also used by Javanese ethnic with different religious backgrounds. Between ethnic China and Java, mutual respect and tolerance run beliefs and rituals of each. More over, Klenteng Sam Po Kong is a form of pluralism which reflected the fact Sino Javanese Muslim Culture is preserved to date both of sightings physical culture and system cultural in the form of religious rites performed by ethnic China and Java.

  9. Concentration and distribution of 210Po in rats exposed to radon

    International Nuclear Information System (INIS)

    Pan Peng; Yang Zhanshan; Wang Tianchang; Tong Jian; Zhou Jianwei

    2007-01-01

    Objective: To study the concentration and distribution of 210 Po in rats exposed to radon and its daughters. Methods: Fifteen male wistar rats were randomly divided into three groups, including one control group and two radon exposed groups with the cumulative doses of 100 WLM (low dose) and 200 WLM (high dose), respectively. Tissue samples containing 210 Po were spontaneously deposited onto silvery discs with the diameter of 20 mm by means of wet ashing and electrodeposition. The concentration of 210 Po in tissues were measured by α spectroscopy, and tissue burden were calculated. Results: The concentrations of 210 Po were significantly different among the three dose groups in femur, liver, sex gland and hair (P 210 Po were different between the exposed groups and the control group in lung and soleus muscle (P 210 Po in lung, spleen and hair were higher than that in liver, bone and sex gland, the lowest was in intestine. The tissue burdens of liver, bone and sex gland were significantly different from those in other organs or tissues. Conclusions: 210 Po was mainly distributed in lung, liver, spleen, femur and sex gland. The concentrations of 210 Po in organs or tissues and the tissue burdens were correspondingly increased with the exposure dose of radon and its daughters. The results of this experiment provide a dosimetric basis for further studies on the carcinogenic effect of radon and its daughters. (authors)

  10. Baseline concentration of {sup 210}Po in Sargassum from the Northern Gulf

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, S.; Bebhehani, M.; Talebi, L. [Kuwait Institute for Scientific Research (Kuwait)

    2014-07-01

    The concentration of the {sup 210}Po is of enormous interest because of its large contribution to the natural radiation dose received by marine organisms and human populations consuming seafood. In fact natural {sup 210}Po is responsible for higher radiation doses to humans consuming marine products than is plutonium and other man-made radionuclides. Many marine organisms are capable of concentrating {sup 210}Po in their tissues. {sup 210}Po is an alpha emitter in the {sup 238}U series, with 138-d half-life, that is supplied to seawater from atmospheric inputs and river runoff, however, the main source of {sup 210}Po in the environment is {sup 222}Rn exhalation from the ground. Assessing the impact of radionuclides in the environment requires the establishment of baseline levels in the environmental compartments. The objective of this study was to establish baseline levels in Sargassum. Two most common species of Sargassum found in the northern Gulf were analysed for {sup 210}Po. These macro-algae were collected from three different locations during January 2013. This study sets the baseline for {sup 210}Po concentration in northern Gulf, {sup 210}Po is absorbed from water and concentrated by Phytoplankton and macro-algae. This concentrated {sup 210}Po can then be passed along to the next trophic level of the marine food web. The {sup 210}Po concentration measured in Sargassum boveanum (4.405 - 4.952 BqKg{sup -1}) was significantly higher (p>0.084) than Sargassum oligocystum (3.838 - 4.358 BqKg{sup -1}). The {sup 210}Po concentration in these seaweeds from the Arabian/Persian Gulf were substantially lower than those found in various Phytoplankton and macro-algae species from other regions; this may be due to the lower background {sup 210}Po concentration in the Kuwait marine waters (0.282 - 0.382 mBq l{sup -1}). The {sup 210}Po concentrations in seawater measured at the 3 stations during January 2013 were less than those reported previously from the same region

  11. Luminescence and scintillation properties of LuPO4-Ce nanoparticles

    International Nuclear Information System (INIS)

    Vistovskyy, V.; Malyy, T.; Pushak, A.; Vas’kiv, A.; Shapoval, A.; Mitina, N.; Gektin, A.; Zaichenko, A.; Voloshinovskii, A.

    2014-01-01

    Study of the spectral-luminescence parameters of LuPO 4 -Ce nanoparticles upon the excitation by X-ray quanta and synchrotron radiation with photon energies of 4–25 eV was performed. Nanoparticles with mean size about a=35 nm and nanoparticles with size less than 12 nm reveal the different structures of cerium centers. Luminescence efficiency of LuPO 4 -Ce nanoparticles of a 4 -Ce nanoparticles studied using synchrotron and X-ray excitation. • Different structure of Ce 3+ -centers has been revealed for LuPO 4 -Ce nanoparticles. • Luminescence of LuPO 4 -Ce with size less than 12 nm is strongly quenched upon the X-ray excitation

  12. Anode property of carbon coated LiFePO4 nanocrystals

    Science.gov (United States)

    Ni, Jiangfeng; Jiang, Jiaxing; Savilov, S. V.; Aldoshin, S. M.

    2016-10-01

    Nanostructured LiFePO4 is appealing cathode material for rechargeable lithium batteries. Herein, however, we report the intriguing anode properties of carbon coated LiFePO4 nanocrystals. In the potential range of 0-3.0 V, the LiFePO4 nanocrystal electrodes afford high reversible capacity of 373 mAhg-1 at a current rate of 0.05 Ag-1 and retains 239 mAhg-1 at a much higher rate of 1.25 Ag-1. In addition, it is capable of sustaining 1000 cycles at 1.25 Ag-1 without any capacity fading. Such superior properties indicate that nanostructured LiFePO4 could also be promising anode for rechargeable battery applications.

  13. Structure determination of AgPO3 and (AgPO3)0.5(AgI)0.5 glasses by neutron diffraction and small angle neutron scattering

    International Nuclear Information System (INIS)

    Tachez, M.; Mercier, R.; Malugani, J.P.; Chieux, P.

    1987-01-01

    Neutron diffraction and small angle neutron scattering (SANS) were performed on AgPO 3 and (AgPO 3 ) 0.5 (AgI) 0.5 glasses. AgPO 3 glass is made up of long chains of PO 4 tetrahedra joined together by Ag atoms. When silver iodide is added, the radial distribution function shows a large peak at 2.83 A, due to Ag-I interactions. AgI does not modify the network forming unit. The existence of small clusters is confirmed by analysing the coordination number of Ag-I pairs obtained by subtracting the experimental structure function of the AgPO 3 glass from that of the corresponding AgI-doped glasses. A rough estimation of their size is given by SANS experiments. Not all the AgI pairs are involved in AgI cluster units. The compatibility of the results obtained with recent structural investigations by non diffractometric techniques is examined. 23 refs.; 5 figs.; 3 tabs

  14. Scintillation characteristics of LiPO3:Ce3+ glass scintillators

    International Nuclear Information System (INIS)

    Shin, S. W.; Hwang, J. H.

    2003-01-01

    LiPO 3 :Ce 3+ glass scintillators doped with 0.5, 0.75, 1.0, 1.25 and 1.5wt% cerium as an activator were fabricated. For the best transparency of the LiPO 3 glasses, optimum heating conditions were investigated. Optimum heating temperature and time is 950 .deg. C and 90 min with 1wt% sugar add as reductant. The lattice structure of LiPO 3 :Ce 3+ glass scintillator was monoclinic, its lattice constants(a 0 , b 0 , c 0 ) being 16,490λ, 5.427λ and 13.120λ. Photo-refraction index of LiPO 3 :Ce 3 + measured by SE(Spectroscopic ellipsometry) was 1.45 ∼ 1.5 and its bandgap energy was 2.342 eV. The absorption spectral range of LiPO 3 :Ce 3+ measured by UV-VIS spectrophotometry was 350∼ 375nm and the spectral ranges of photoluminescence(PL) were 400∼450nm and 750∼900nm, its maximum PL intensity appeared at 417nm and 791nm. LiPO 3 :Ce 3 + glass scintillator doped with 0.75wt% cerium showed the best PL intensity. The PL intensity increased until cerium content reaches 0.75wt% above which ir decreased

  15. Synthesis and vibrational spectrum of antimony phosphate, SbPO4.

    Science.gov (United States)

    Brockner, Wolfgang; Hoyer, Lars P

    2002-07-01

    SbPO4 was synthesized via a new route by reacting antimony metal with meta-phosphoric acid, (HPO3)n at high temperatures. The Raman and IR spectra of the title compound were recorded and the vibrational modes assigned on the basis of a factor group analysis. The internal vibrations are derived from tetrahedral PO4 units (approaching Sb[PO4]) by the correlation method, although the structure is polymeric and not ionic.

  16. Dynamic PROOF clusters with PoD: architecture and user experience

    Science.gov (United States)

    Manafov, Anar

    2011-12-01

    PROOF on Demand (PoD) is a tool-set, which sets up a PROOF cluster on any resource management system. PoD is a user oriented product with an easy to use GUI and a command-line interface. It is fully automated. No administrative privileges or special knowledge is required to use it. PoD utilizes a plug-in system, to use different job submission front-ends. The current PoD distribution is shipped with LSF, Torque (PBS), Grid Engine, Condor, gLite, and SSH plug-ins. The product is to be extended. We therefore plan to implement a plug-in for AliEn Grid as well. Recently developed algorithms made it possible to efficiently maintain two types of connections: packet-forwarding and native PROOF connections. This helps to properly handle most kinds of workers, with and without firewalls. PoD maintains the PROOF environment automatically and, for example, prevents resource misusage in case when workers idle for too long. As PoD matures as a product and provides more plug-ins, it's used as a standard for setting up dynamic PROOF clusters in many different institutions. The GSI Analysis Facility (GSIAF) is in production since 2007. The static PROOF cluster has been phased out end of 2009. GSIAF is now completely based on PoD. Users create private dynamic PROOF clusters on the general purpose batch farm. This provides an easier resource sharing between interactive local batch and Grid usage. The main user communities are FAIR and ALICE.

  17. Enhanced electrochemical performance of different morphological C/LiMnPO4 nanoparticles from hollow-sphere Li3PO4 precursor via a delicate polyol-assisted hydrothermal method

    Science.gov (United States)

    Cui, Yu-Ting; Xu, Ning; Kou, Li-Qin; Wu, Meng-Tao; Chen, Li

    2014-03-01

    With the hollow-sphere Li3PO4 as precursor, a delicate polyol-assisted hydrothermal method is devised to synthesize high-performance LiMnPO4. Orthorhombic shaped, irregular flaky shaped and sphere-like LiMnPO4 are sequentially prepared by decreasing the water-diethylene glycol (DEG) ratio. The capacity, cycling stability and rate performance of all samples prepared by the new synthesis method are improved significantly. And the C/LiMnPO4 with irregular flaky shape exhibits a capacity of 154.1 mA h g-1 at C/20, 147.4 mA h g-1 at C/10 and 102.5 mA h g-1 at 2 C, which is the best performance ever reported for LiMnPO4 active material with similar carbon additives.

  18. 210Pb and 210Po activities in French foodstuffs

    International Nuclear Information System (INIS)

    Renaud, Ph.; Roussel-Debet, S.; Pourcelot, L.; Thebault, H.; Loyen, J.; Gurriaran, R.

    2015-01-01

    The data on 210 Pb and 210 Po activities in French foodstuffs acquired during the last 15 years are numerous enough to derive reference values which will be usable to assess the dose to the French population due to the intake of these two natural radionuclides. The means and ranges are close to those observed in various countries and are most often higher than the reference values proposed by UNSCEAR. Mussels and oysters exhibit the highest 210 Po activities of all kinds of foodstuffs, with a mean value of 27 Bq.kg -1 fresh weight, followed by crustaceans and small fish species (anchovies, mullets, sardines, etc.) with 210 Po activities in the order of 3 to 10 Bq.k -1 fresh weight; cephalopods and other fish species presenting activities around 1 to 3 Bq.kg -1 fresh, close to the UNSCEAR reference value. Below these highest 210 Po activities are those of 210 Po and 210 Pb in terrestrial kinds of foodstuffs, by decreasing order: meats (around 1 Bq.kg -1 fresh), cereals (0.4 Bq.kg -1 ), leafy vegetables (0.3 Bq.kg -1 ), other vegetables and fruits (0.1 Bq.kg -1 ), and milk (from 0.03 to 0.1 Bq.L -1 ). (authors)

  19. Synthesis and Electrochemical Properties of LiFePO4/C for Lithium Ion Batteries.

    Science.gov (United States)

    Gao, Hong; Wang, Jiazhao; Yin, Shengyu; Zheng, Hao; Wang, Shengfu; Feng, Chuanqi; Wang, Shiquan

    2015-03-01

    LiFePO4/C was prepared through a facile rheological phase reaction method by using Fe3(PO4)2, Li3PO4 · 8H2O, and glucose as reactants. The LiFePO4/C samples were characterized by X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis. The electrochemical properties of the samples were investigated. The results show that the LiFePO4/C samples have single-phase olivine-type structure, and their particles feature a spherical shape. The carbon coating on the particles of LiFePO4 is about 1.8% of the LiFePO4/C by weight. The particle size was distributed from 0.2 to 1 µm. The initial discharge capacity of LiFePO4/C reached 154 mA h/g at 0.1 C. The retained discharge capacity of LiFePO4/C was 152.9 mA h g(-1) after 50 cycles. The LiFePO4/C also showed better cycling performance than that of the bare LiPeO4 at a higher charge/discharge rate (1 C). The LIFePO4/C prepared in this way could be a promising cathode material for lithium ion battery application.

  20. Phase equilibria in the system Nd(PO3)3 - KPO3

    International Nuclear Information System (INIS)

    Znamierowska, T.; Mizer, D.

    2002-01-01

    The system Nd(PO 3 ) 3 - KPO 3 has been investigated by differential thermal analysis (during heating), thermogravimetric analysis, mass spectrometry, Raman spectroscopy and X-ray powder diffraction and its phase diagram was proposed. It was discovered that initial metaphosphates react at a 1:1 molar ratio forming intermediate compound KNd(PO 3 ) 4 . It was found that it melts incongruently at 854 o C giving Nd(po)3) 3 and a liquid rich in KPO 3 . Phosphate KNd(PO 3 ) 4 is stable down to room temperature and does not show any polymorphic transitions. (author)

  1. Accumulation of /sup 210/Po in selected species of Baltic fish

    Energy Technology Data Exchange (ETDEWEB)

    Skwarzec, B

    1988-01-01

    Results are presented here for the /sup 210/Po contents of selected species of Baltic fish. It is shown that /sup 210/Po is non-uniformly distributed within these fish, the highest levels being found in the digestive organs, particularly within the intestine. It is found that the proportional contribution by the digestive organs to the total accumulation of /sup 210/Po is correlated with the degree of repletion of the stomach and that this decreases if food is lacking. Moreover, it is observed that fish represent an important source of supply of /sup 210/Po to humans.

  2. PO2 Cycling Reduces Diaphragm Fatigue by Attenuating ROS Formation

    OpenAIRE

    Zuo, Li; Diaz, Philip T.; Chien, Michael T.; Roberts, William J.; Kishek, Juliana; Best, Thomas M.; Wagner, Peter D.

    2014-01-01

    Prolonged muscle exposure to low PO2 conditions may cause oxidative stress resulting in severe muscular injuries. We hypothesize that PO2 cycling preconditioning, which involves brief cycles of diaphragmatic muscle exposure to a low oxygen level (40 Torr) followed by a high oxygen level (550 Torr), can reduce intracellular reactive oxygen species (ROS) as well as attenuate muscle fatigue in mouse diaphragm under low PO2. Accordingly, dihydrofluorescein (a fluorescent probe) was used to monito...

  3. Efficient UV-emitting X-ray phosphors: octahedral Zr(PO4)6 luminescence centers in potassium hafnium-zirconium phosphates K2Hf1-xZrx(PO4)2 and KHf2(1-x)Zr2x(PO4)3

    International Nuclear Information System (INIS)

    Torardi, C.C.; Miao, C.R.; Li, J.

    2003-01-01

    Potassium hafnium-zirconium phosphates, K 2 Hf 1-x Zr x (PO 4 ) 2 and KHf 2(1-x) Zr 2x (PO 4 ) 3 , are broad-band UV-emitting phosphors. At room temperature, they have emission peak maxima at approximately 322 and 305 nm, respectively, under 30 kV peak molybdenum X-ray excitation. Both phosphors demonstrate luminescence efficiencies that make them up to ∼60% as bright as commercially available CaWO 4 Hi-Plus. The solid-state and flux synthesis conditions, and X-ray excited UV luminescence of these two phosphors are discussed. Even though the two compounds have different atomic structures, they contain zirconium in the same active luminescence environment as that found in highly efficient UV-emitting BaHf 1-x Zr x (PO 4 ) 2 . All the three materials have hafnium and zirconium in octahedral coordination via oxygen-atom corner sharing with six separate PO 4 tetrahedra. This octahedral Zr(PO 4 ) 6 moiety appears to be an important structural element for efficient X-ray excited luminescence, as are the edge-sharing octahedral TaO 6 chains for tantalate emission

  4. H-PoP and H-PoPG: heuristic partitioning algorithms for single individual haplotyping of polyploids.

    Science.gov (United States)

    Xie, Minzhu; Wu, Qiong; Wang, Jianxin; Jiang, Tao

    2016-12-15

    Some economically important plants including wheat and cotton have more than two copies of each chromosome. With the decreasing cost and increasing read length of next-generation sequencing technologies, reconstructing the multiple haplotypes of a polyploid genome from its sequence reads becomes practical. However, the computational challenge in polyploid haplotyping is much greater than that in diploid haplotyping, and there are few related methods. This article models the polyploid haplotyping problem as an optimal poly-partition problem of the reads, called the Polyploid Balanced Optimal Partition model. For the reads sequenced from a k-ploid genome, the model tries to divide the reads into k groups such that the difference between the reads of the same group is minimized while the difference between the reads of different groups is maximized. When the genotype information is available, the model is extended to the Polyploid Balanced Optimal Partition with Genotype constraint problem. These models are all NP-hard. We propose two heuristic algorithms, H-PoP and H-PoPG, based on dynamic programming and a strategy of limiting the number of intermediate solutions at each iteration, to solve the two models, respectively. Extensive experimental results on simulated and real data show that our algorithms can solve the models effectively, and are much faster and more accurate than the recent state-of-the-art polyploid haplotyping algorithms. The experiments also show that our algorithms can deal with long reads and deep read coverage effectively and accurately. Furthermore, H-PoP might be applied to help determine the ploidy of an organism. https://github.com/MinzhuXie/H-PoPG CONTACT: xieminzhu@hotmail.comSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. Bioaccumulation of polonium 210Po in marine birds

    International Nuclear Information System (INIS)

    Skwarzec, B.; Fabisiak, J.

    2007-01-01

    The aim of this work was to determine the 210 Po content in marine birds which permanently or temporally live in the Polish part of the Baltic Sea. We chose 11 species of sea birds: three species permanently residing at southern Baltic Sea, four species of wintering birds and three species of migrating birds. The results show that the polonium is non-uniformly distributed in the marine birds. The highest activities of 210 Po were observed in feathers, muscles and liver and the lowest in skin and skeleton. Species of birds that eat crustaceans, molluscs, fish and plants (long-tailed duck Clangula hyemalis, white-winged scoter Melanitta fusca) accumulated more polonium than species that eat mainly fish (great cormorant Phalacrocorax carbo, common guillemot Uria aalge) or plants (tufted duck Aythya fuligula). Moreover, about 63% of the 210 Po that was located in feathers of razorbil (Alca torda) and long-tailed duck (C. hyemalis) was apparently adsorbed, suggesting an external source such as the air. It means that the adsorption of 210 Po on the feather surface may be an important transfer from air to water

  6. Experiments for detection of gaseous Po-210 originated from microbial activity in the environment

    International Nuclear Information System (INIS)

    Ishimoto, A.; Momoshima, N.

    2006-01-01

    We attempted to detect gaseous Po-210 (half-life 138d) emitted from organisms in the environment. Gaseous Po-210 was tried to collect in 0.5 M nitric acid solution after passing the atmospheric air through filters and a distilled water bubbler, which would remove aerosols existing in the air. The activity of Po-210 was determined by alpha spectrometry after radiochemical separation and electrolytic deposition of Po-210 on a silver disk. Twenty seven point four mBq of Po-210 was observed when 800 m 3 atmospheric air was sampled. Blank of Po-210 in regents and the sampling system was 4.9-6.8 mBq. The concentration of Po-210 observed in the atmospheric air was, thus about 5 times higher than the background; the results strongly support existence of gaseous Po-210 in the environment. (author)

  7. Equilibrium diagram of KPO{sub 3}-Y(PO{sub 3}){sub 3} system, chemical preparation and characterization of KY(PO{sub 3}){sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Jouini, Anis; Ferid, Mokhtar; Trabelsi-Ayadi, Malika

    2003-04-17

    Microdifferential thermal analysis ({mu}-DTA), X-ray diffraction (XRD) and infrared (IR) spectroscopy were used for the first time to investigate the liquidus and solidus relations in the KPO{sub 3}-Y(PO{sub 3}){sub 3} system. The only compound observed within the system was KY(PO{sub 3}){sub 4} melting incongruently at 1033 K. An eutectic appears at 13.5 mol% Y(PO{sub 3}){sub 3} at 935 K, the peritectic occurs at 1033 K and the phase transition for potassium polyphosphate KPO{sub 3} was observed at 725 K. Three monoclinic allotropic phases of the single crystals were obtained. KY(PO{sub 3}){sub 4} polyphosphate has the P2{sub 1} space group with lattice parameters: a=7.183(4) A, b=8.351(6) A, c=7.983(3) A, {beta}=91.75(3) deg. and Z=2 is isostructural with KNd(PO{sub 3}){sub 4}. The second allotropic form of KY(PO{sub 3}){sub 4} belongs to the P2{sub 1}/n space group with lattice parameters: a=10.835(3) A, b=9.003(2) A, c=10.314(1) A, {beta}=106.09(7) deg. and Z=4 and is isostructural with TlNd(PO{sub 3}){sub 4}. The IR absorption spectra of the two forms show a chain polyphosphates structure. The last modification of KYP{sub 4}O{sub 12} crystallizes in the C2/c space group with lattice parameters: a=7.825(3) A, b=12.537(4) A, c=10.584(2) A, {beta}=110.22(7) deg. and Z=4 is isostructural with RbNdP{sub 4}O{sub 12} and contains cyclic anions. The methods of chemical preparations, the determination of crystallographic data and IR spectra for these compounds are reported.

  8. Ra-226, Pb-210, and Po-210 in the Black Forest

    International Nuclear Information System (INIS)

    Schuettelkopf, H.; Kiefer, H.

    1981-01-01

    By measuring Pb-210, Po-210 and Ra 226 in air, water, ground, plants, and food samples the concentration ranges of the radionuclide and the transfer factor important for the calculation of the ingestion dose of man were determined. Po 210 was found to have the lowest radiotoxicity. The highest Po-210 concentrations were found in protein-containing food. (DG) [de

  9. 210Po content in human urine of people living in south of Spain

    International Nuclear Information System (INIS)

    Díaz-Francés, I.; García-Tenorio, R.; Mantero, J.; Manjón, G.

    2013-01-01

    The death of the former secret service agent Alexander Livitnenko in 2006 due to a lethal intake of 210 Po, presumably via ingestion, sparked renewed interest in the field of 210 Po toxicity to humans. 210 Po occurs widely in nature and is an important component of man' s natural radiation background. The main route of 210 Po intake by the human body is the ingestion with foodstuffs, although ingestion with drinking water especially of underground origin represents another route of 210 Po intakes. Inhalation of 222 Rn released from the soil also contributes in 210 Po body burden. However, the body burden of 210 Po in normal human body may differ from one person to another depending upon the mode life including diet habits, origin of drinking water, residence place (radon exposure rate) and also smoking habits. Therefore, many factors may affect the 210 Po intake and lead to variations in the body burden in different individuals, and consequently in their urine. To see the influence of the diet habits in the amount of 210 Po excreted by urine, some volunteers in Seville (south of Spain) follow defined diets during approximately one month, with daily urine collection followed by 210 Po determination by alpha-particle spectrometry. Depending on the type of diet ingested by the different volunteers, it was observed differences approaching even an order of magnitude in their levels of 210 Po in urine. This fact difficult enormously the adoption of a predefined value of this nuclide in urine with natural origin with the consequence difficulties for screening through urine the possible anthropogenic intake of this element. (author)

  10. Study about excretion of 210 Po in urine

    International Nuclear Information System (INIS)

    Fonseca Azeredo, A.M.G. da.

    1988-01-01

    The urine of mines's workers are analysed to detect the presence of 210 Po. The results was compared with the workers and with a control population. Cigarettes samples was analysed two and confirmed the 210 presence. The control population individuals were divided in smokers and non smokers and them urine was investigated the influence of the smoke in the 210 Po excretion. (L.M.J.)

  11. Levels of 210 Pb and 210 Po in Brazilian cigarettes

    International Nuclear Information System (INIS)

    Santos, Pedro Lopes dos; Kelecom, Alphonse; Gouvea, Rita de Cassia dos Santos; Dutra, Iedo Ramos

    1996-01-01

    210 Po and 210 Pb concentrations have been determined in 18 Brazilian cigarette samples and compared with known data on U content. U is respectively 3-fold less and 4-fold less abundant than 210 Po or 210 Pb. No correlation could be observed between U concentration and those of Po or Pb. The mean concentration of 210 Pb is higher than that of 210 Pb observed in many other plants, even in plants frown in high background areas. (author)

  12. Electrochemical performances of LiMnPO4 synthesized from non-stoichiometric Li/Mn ratio.

    Science.gov (United States)

    Xiao, Jie; Chernova, Natasha A; Upreti, Shailesh; Chen, Xilin; Li, Zheng; Deng, Zhiqun; Choi, Daiwon; Xu, Wu; Nie, Zimin; Graff, Gordon L; Liu, Jun; Whittingham, M Stanley; Zhang, Ji-Guang

    2011-10-28

    In this paper, the influences of the lithium content in the starting materials on the final performances of as-prepared Li(x)MnPO(4) (x hereafter represents the starting Li content in the synthesis step which does not necessarily mean that Li(x)MnPO(4) is a single phase solid solution in this work.) are systematically investigated. It has been revealed that Mn(2)P(2)O(7) is the main impurity when Li Li(3)PO(4) begins to form once x > 1.0. The interactions between Mn(2)P(2)O(7) or Li(3)PO(4) impurities and LiMnPO(4) are studied in terms of the structural, electrochemical, and magnetic properties. At a slow rate of C/50, the reversible capacity of both Li(0.5)MnPO(4) and Li(0.8)MnPO(4) increases with cycling. This indicates a gradual activation of more sites to accommodate a reversible diffusion of Li(+) ions that may be related to the interaction between Mn(2)P(2)O(7) and LiMnPO(4) nanoparticles. Among all of the different compositions, Li(1.1)MnPO(4) exhibits the most stable cycling ability probably because of the existence of a trace amount of Li(3)PO(4) impurity that functions as a solid-state electrolyte on the surface. The magnetic properties and X-ray absorption spectroscopy (XAS) of the MnPO(4)·H(2)O precursor, pure and carbon-coated Li(x)MnPO(4) are also investigated to identify the key steps involved in preparing a high-performance LiMnPO(4). This journal is © the Owner Societies 2011

  13. PEMODELAN KONDUKTIVITAS ION DALAM STRUKTUR Li2Sc3(PO43 (Modeling Ionic Conductivity in Li2Sc3(PO43 Structure

    Directory of Open Access Journals (Sweden)

    Akram La Kilo

    2011-11-01

    Full Text Available ABSTRAK Fasa Li2Sc3(PO43 merupakan material konduktor superionik yang dapat diaplikasikan sebagai baterai yang dapat diisi ulang (rechargeable. Ion Li+ dalam struktur Li2Sc3(PO4 dapat mengalami migrasi dari posisi terisi ke posisi kosong. Penelitian ini telah memodelkan migrasi ion Li+ dalam struktur Li2Sc3(PO4 dengan menggunakan metode bond valence sum (BVS. Metode ini dapat memprediksi bilangan oksidasi suatu atom berdasarkan jarak dengan atom-atom tetangga. Source code berbasis BVS yang digunakan adalah JUMPITER yang mensimulasi efek gaya listrik eksternal yang bertindak pada ion litium sehingga nilai BVS litium dapat dipetakan terhadap jarak. Hasil simulasi menunjukkan bahwa konduksi ion Li+ dapat terjadi pada arah [010], [101], dan [120]. Namun, lintasan konduksi ion Li+ lebih mudah terjadi pada arah [120] atau bidang ab dengan nilai maksimum BVS adalah 0,982. ABSTRACT g-phase of Li2Sc3(PO43 is a lithium super ionic conductor which can be applied as a rechargeable lithium battery. Lithium ions of g-Li2Sc3(PO43 can migrate from occupied site to vacant site. In this research, simulation of Li+ ions migration in the structure of g-Li2Sc3(PO43 carried out using bond valence sum (BVS to predict the oxidation state of Li+ion based on the distance of the ion to neighboring atoms. BVS-based code used JUMPITER to simulate the effect of external electrical force acting on the lithium ions to produce the lithium BVS value which can be mapped to the distance. The simulation results shows that Li+ ion conduction can be occurred on [010], [101], and [120] directions. However, the Li ion conduction pathway occur more easily in the direction of [120] or ab plane with the BVS maximum value is 0.982.

  14. Quantum-Chemical Approach to NMR Chemical Shifts in Paramagnetic Solids Applied to LiFePO4 and LiCoPO4.

    Science.gov (United States)

    Mondal, Arobendo; Kaupp, Martin

    2018-04-05

    A novel protocol to compute and analyze NMR chemical shifts for extended paramagnetic solids, accounting comprehensively for Fermi-contact (FC), pseudocontact (PC), and orbital shifts, is reported and applied to the important lithium ion battery cathode materials LiFePO 4 and LiCoPO 4 . Using an EPR-parameter-based ansatz, the approach combines periodic (hybrid) DFT computation of hyperfine and orbital-shielding tensors with an incremental cluster model for g- and zero-field-splitting (ZFS) D-tensors. The cluster model allows the use of advanced multireference wave function methods (such as CASSCF or NEVPT2). Application of this protocol shows that the 7 Li shifts in the high-voltage cathode material LiCoPO 4 are dominated by spin-orbit-induced PC contributions, in contrast with previous assumptions, fundamentally changing interpretations of the shifts in terms of covalency. PC contributions are smaller for the 7 Li shifts of the related LiFePO 4 , where FC and orbital shifts dominate. The 31 P shifts of both materials finally are almost pure FC shifts. Nevertheless, large ZFS contributions can give rise to non-Curie temperature dependences for both 7 Li and 31 P shifts.

  15. Annual dose of Taiwanese from the ingestion of 210Po in oysters.

    Science.gov (United States)

    Lee, Hsiu-wei; Wang, Jeng-Jong

    2013-03-01

    Oysters around the coast of Taiwan were collected, dried, spiked with a (209)Po tracer for yield, digested with concentrated HNO(3) and H(2)O(2), and finally dissolved in 0.5 N HCl. The polonium was then spontaneously deposited onto a silver disc, and the activity of (210)Po was measured using an alpha spectrum analyzer equipped with a silicon barrier detector. Meanwhile, the internal effective dose of (210)Po coming from the intake of oysters by Taiwanese was evaluated. The results of the present study indicate that (210)Po average activity concentrations ranged from 23.4 ± 0.4 to 126 ± 94 Bq kg(-1) of fresh oysters. The oysters coming from Penghu island and Kinmen island regions contain higher concentrations of (210)Po in comparison with oysters from other regions of Taiwan. The value of (210)Po weighted average activity concentrations for all oyster samples studied is 25.9 Bq kg(-1). The annual effective dose of Taiwanese due to the ingestion of (210)Po in oysters was estimated to be 4.1 × 10(-2) mSv y(-1). Copyright © 2013. Published by Elsevier Ltd.

  16. The electrical and diffusive properties of unattached 218Po in argon gas

    International Nuclear Information System (INIS)

    Leung, H.M.-Y.; Phillips, C.R.

    1987-01-01

    Electrical and diffusive properties of unattached 218 Po were investigated in argon Parameters determined in electrostatic collection experiments were radon concentration, the fraction of 218 Po having a positive charge at the end of the recoil path, the diffusion coefficient of the neutral 218 Po species, and the ratio of the neutralisation rate constant of charged 218 Po species to the electrical mobility of charged 218 Po species. Independent electrical mobility data were obtained using a pulse width modulated ion mobility analyser. The neutralisation rate constant for charged 218 Po species was then determined from the electrostatic collection data together with the independent mobility data. Relative humidity (RH) and radon concentration were found to affect the neutralisation mechanism. Following recoil of the charged 218 Po species, neutralisation through recombination with small negative ions is important for radon concentrations greater than about 1.0 x 10 5 atoms cm -3 . The neutralisation rate constant is proportional to about the 0.6 power of the radon concentration for all relative humidities. At a radon concentration less than about 1.0 x 10 5 atoms cm -3 , the neutralisation rate constant is independent of radon concentration. (author)

  17. Modeling Li-ion conductivity in LiLa(PO3)4 powder

    International Nuclear Information System (INIS)

    Mounir, Ferhi; Karima, Horchani-Naifer; Khaled, Ben Saad; Mokhtar, Férid

    2012-01-01

    Polycrystalline powder and single-crystal of LiLa(PO 3 ) 4 are synthesized by solid state reaction and flux technique, respectively. A morphological description of the obtained product was made based on scanning electron microscopy micrographs. The obtained powder was characterized by X-ray powder diffraction, FTIR and Raman spectroscopies. Ionic conductivity of the LiLa(PO 3 ) 4 powder was measured and evaluated over a temperature range from 553 to 913 K. Single crystals of LiLa(PO 3 ) 4 are characterized by single-crystal X-ray diffraction. The LiLa(PO 3 ) 4 structure was found to be isotypic with LiNd(PO 3 ) 4 . It crystallizes in the monoclinic system with space group C2/c and cell parameters: a=16.635(6) Å, b=7.130(3) Å, c=9.913(3) Å, β=126.37(4)°, V=946.72(6) Å 3 and Z=4. The LiLa(PO 3 ) 4 structure was described as an alternation between spiraling chains (PO 3 ) n and (La 3+ , Li + ) cations along the b direction. The small Li + ions, coordinated to four oxygen atoms, were located in the large connected cavities created between the LaO 8 polyhedra and the polyphosphate chains. The jumping of Li + through tunnels of the crystalline network was investigated using complex impedance spectroscopy. The close value of the activation energies calculated through the analysis of conductivity data and loss spectra indicate that the transport in the investigated system is through hopping mechanism. The correlation between ionic conductivity of LiLa(PO 3 ) 4 and its crystallographic structure was investigated and the most probably transport pathway model was determined.

  18. Inelastic neutron scattering and lattice dynamics of GaPO4

    International Nuclear Information System (INIS)

    Mittal, R.; Chaplot, S.L.; Kolesnikov, A.I.; Loong, C.K.; Jayakumar, O.D.; Kulshreshtha, S.K.

    2004-01-01

    We report here measurements of phonon spectrum and lattice dynamical calculations for GaPO 4 . The measurements in low-cristobalite phase of GaPO 4 are carried out using high-resolution medium-energy chopper spectrometer at ANL, USA in the energy transfer range 0-160 MeV. Semiempirical interatomic potential in GaPO 4 , previously determined using ab-initio calculations have been widely used in studying the phase transitions among various polymorphs. The calculated phonon spectrum using the available potential show fair agreement with the experimental data. However, the agreement between the two is improved by including the polarisability of the oxygen atoms in the framework of the shell model. The lattice dynamical models are also exploited for calculations of various thermodynamic properties of GaPO 4 . (author)

  19. Study on the excretion of pb-210 and po-210

    Energy Technology Data Exchange (ETDEWEB)

    Okabayashi, Hiroyuki [National Inst. of Radiological Sciences, Chiba (Japan)

    1982-06-01

    The amount of Po-210 excreted in urine and feces was more influenced by Po-210 that was taken with food and drink than taken through inhalation. The amount of Pb-210 in urine of mining workers among uranium mine workers was higher than that of the non-uranium mine workers. It was thought that this fact was due to the working environment in uranium mine the amount of Pb-210 being a few tens times higher than that in normal environment. The activity ratios of Po-210 of faecal to urinary excretion are widely distributed, however, the average value of many samples approached to 10. Urinary excretion of Po-210 was highest after 24 hours of ingestion, but for faecal excretion, it was highest after 3 day.

  20. Determination and distribution of 210Po in tobacco plants from Poland

    International Nuclear Information System (INIS)

    Skwarzec, B.; Struminska, D.I.; Ulatowski, J.; Golebiowski, M.

    2001-01-01

    One of the most radiotoxic elements, 210 Po in different parts of tobacco plant from Poland was determined. Investigation revealed that polonium is non-uniformly distributed within tobacco plant. Tobacco leaves constituting about 50% of the wet mass, contain 87.1% of the total burden of 210 Po. Among the analyzed leaves about 66% of polonium is located in the oldest, over-ground part. It was indicated that 210 Po is generally taken up by tobacco from the dry or wet deposition of the radioactive fall-out onto the plant. Moreover, 210 Po concentration in tobacco leaves from Poland are higher than that in the other countries. (author)

  1. Skeletal muscle microvascular and interstitial PO2 from rest to contractions.

    Science.gov (United States)

    Hirai, Daniel M; Craig, Jesse C; Colburn, Trenton D; Eshima, Hiroaki; Kano, Yutaka; Sexton, William L; Musch, Timothy I; Poole, David C

    2018-03-01

    Oxygen pressure gradients across the microvascular walls are essential for oxygen diffusion from blood to tissue cells. At any given flux, the magnitude of these transmural gradients is proportional to the local resistance. The greatest resistance to oxygen transport into skeletal muscle is considered to reside in the short distance between red blood cells and myocytes. Although crucial to oxygen transport, little is known about transmural pressure gradients within skeletal muscle during contractions. We evaluated oxygen pressures within both the skeletal muscle microvascular and interstitial spaces to determine transmural gradients during the rest-contraction transient in anaesthetized rats. The significant transmural gradient observed at rest was sustained during submaximal muscle contractions. Our findings support that the blood-myocyte interface provides substantial resistance to oxygen diffusion at rest and during contractions and suggest that modulations in microvascular haemodynamics and red blood cell distribution constitute primary mechanisms driving increased transmural oxygen flux with contractions. Oxygen pressure (PO2) gradients across the blood-myocyte interface are required for diffusive O 2 transport, thereby supporting oxidative metabolism. The greatest resistance to O 2 flux into skeletal muscle is considered to reside between the erythrocyte surface and adjacent sarcolemma, although this has not been measured during contractions. We tested the hypothesis that O 2 gradients between skeletal muscle microvascular (PO2 mv ) and interstitial (PO2 is ) spaces would be present at rest and maintained or increased during contractions. PO2 mv and PO2 is   were determined via phosphorescence quenching (Oxyphor probes G2 and G4, respectively) in the exposed rat spinotrapezius during the rest-contraction transient (1 Hz, 6 V; n = 8). PO2 mv was higher than PO2 is in all instances from rest (34.9 ± 6.0 versus 15.7 ± 6.4) to contractions (28.4 ± 5

  2. The electrical and diffusive properties of unattached 218Po in air systems

    International Nuclear Information System (INIS)

    Leung, H.M.-Y.; Phillips, C.R.

    1988-01-01

    The electrical and diffusive properties of unattached 218 Po were determined in air environments containing traces of other gases. Of particular interest was the neutralisation of charged, unattached 218 Po. An electrostatic collection apparatus and a pulse width modulated ion mobility analyser were used to determine the fraction of the unattached 218 Po having a positive charge at the end of the recoil path (f); the diffusion coefficient of the neutral, unattached 218 Po Dsub(Α): the mobility of the charged, unattached 218 Po (B); and the neutralisation rate constant of charged, unattached 218 Po (K). Average values found for f, Dsub(Α), B and K were similar to those determined earlier for the argon system. Two mechanisms may be responsible for neutralisation, namely, scavenging of electrons from trace gases (charge transfer), and recombination with negative small ions. Which neutralisation mechanism is dominant depends on the amount and type of trace gas or organic vapour present and the degree of gas ionisation. (author)

  3. Multi-year Surface Deposition of {sup 210}Pb and {sup 210}Po at Lisbon - Atmospheric Depositions of {sup 210}Pb and {sup 210}Po in Lisbon, Portugal

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Fernando P.; Oliveira, Joao M.; Alberto, G. [Instituto Superior Tecnico/ Campus Tecnologico e Nuclear, Universidade Tecnica de Lisboa, E.N. 10, 2686-953 Sacavem (Portugal)

    2014-07-01

    The long lived radon daughters {sup 210}Pb and {sup 210}Po were determined in samples of total atmospheric depositions obtained with surface collectors continuously operated during 5 years, near Lisbon. The average annual {sup 210}Pb flux was 66±12 Bq m{sup -2}, and the average annual {sup 210}Po flux was 8±3 Bq m{sup -2}, with an overall {sup 210}Po/{sup 210}Pb activity ratio of 0.15±0.06. Direct determination of the {sup 210}Pb atmospheric flux was compared with the {sup 210}Pb excess determined in soil surface layers along with atmospheric depositions of {sup 137}Cs. The deposition of atmospheric {sup 210}Pb was positively correlated with seasonal rainfall, while {sup 210}Po was mainly originated in soil particles re-suspension throughout the year and also in seasonal forest fires. Unusually high {sup 210}Po/{sup 210}Pb activity ratios, higher than unity, were occasionally recorded in atmospheric depositions and the sources and causes are discussed. Long time-series of {sup 210}Pb and {sup 210}Po deposition fluxes, as presented herein are useful to test and constrain parameters of the atmospheric Global Circulation Models. (authors)

  4. El lenguaje poético

    Directory of Open Access Journals (Sweden)

    Alfonso Hanssen

    1966-03-01

    Full Text Available Me parece absurdo pretender hallar la intención poética en cualesquiera rastros de la historia, por el solo hecho de que en ellos se afirma cierta reconditez que los hace misteriosos.

  5. Synthesis of superior fast charging-discharging nano-LiFePO4/C from nano-FePO4 generated using a confined area impinging jet reactor approach.

    Science.gov (United States)

    Liu, Xiao-min; Yan, Pen; Xie, Yin-Yin; Yang, Hui; Shen, Xiao-dong; Ma, Zi-Feng

    2013-06-14

    LiFePO4/C nanocomposites with excellent electrochemical performance is synthesized from nano-FePO4, generated by a novel method using a confined area impinging jet reactor (CIJR). When discharged at 80 C (13.6 Ag(-1)), the LiFePO4/C delivers a discharge capacity of 95 mA h g(-1), an energy density of 227 W h kg(-1) and a power density of 34 kW kg(-1).

  6. Low Po2 conditions induce reactive oxygen species formation during contractions in single skeletal muscle fibers

    Science.gov (United States)

    Shiah, Amy; Roberts, William J.; Chien, Michael T.; Wagner, Peter D.; Hogan, Michael C.

    2013-01-01

    Contractions in whole skeletal muscle during hypoxia are known to generate reactive oxygen species (ROS); however, identification of real-time ROS formation within isolated single skeletal muscle fibers has been challenging. Consequently, there is no convincing evidence showing increased ROS production in intact contracting fibers under low Po2 conditions. Therefore, we hypothesized that intracellular ROS generation in single contracting skeletal myofibers increases during low Po2 compared with a value approximating normal resting Po2. Dihydrofluorescein was loaded into single frog (Xenopus) fibers, and fluorescence was used to monitor ROS using confocal microscopy. Myofibers were exposed to two maximal tetanic contractile periods (1 contraction/3 s for 2 min, separated by a 60-min rest period), each consisting of one of the following treatments: high Po2 (30 Torr), low Po2 (3–5 Torr), high Po2 with ebselen (antioxidant), or low Po2 with ebselen. Ebselen (10 μM) was administered before the designated contractile period. ROS formation during low Po2 treatment was greater than during high Po2 treatment, and ebselen decreased ROS generation in both low- and high-Po2 conditions (P Po2. Force was reduced >30% for each condition except low Po2 with ebselen, which only decreased ∼15%. We concluded that single myofibers under low Po2 conditions develop accelerated and more oxidative stress than at Po2 = 30 Torr (normal human resting Po2). Ebselen decreases ROS formation in both low and high Po2, but only mitigates skeletal muscle fatigue during reduced Po2 conditions. PMID:23576612

  7. PO2 measurements in the microcirculation using phosphorescence quenching microscopy at high magnification.

    Science.gov (United States)

    Golub, Aleksander S; Pittman, Roland N

    2008-06-01

    In phosphorescence quenching microscopy (PQM), the multiple excitation of a reference volume produces the integration of oxygen consumption artifacts caused by individual flashes. We analyzed the performance of two types of PQM instruments to explain reported data on Po2 in the microcirculation. The combination of a large excitation area (LEA) and high flash rate produces a large oxygen photoconsumption artifact manifested differently in stationary and flowing fluids. A LEA instrument strongly depresses Po2 in a motionless tissue, but less in flowing blood, creating an apparent transmural Po2 drop in arterioles. The proposed model explains the mechanisms responsible for producing apparent transmural and longitudinal Po2 gradients in arterioles, a Po2 rise in venules, a hypothetical high respiration rate in the arteriolar wall and mesenteric tissue, a low Po2 in lymphatic microvessels, and both low and uniform tissue Po2. This alternative explanation for reported paradoxical results of Po2 distribution in the microcirculation obviates the need to revise the dominant role of capillaries in oxygen transport to tissue. Finding a way to eliminate the photoconsumption artifact is crucial for accurate microscopic oxygen measurements in microvascular networks and tissue. The PQM technique that employs a small excitation area (SEA) together with a low flash rate was specially designed to avoid accumulated oxygen photoconsumption in flowing blood and lymph. The related scanning SEA instrument provides artifact-free Po2 measurements in stationary tissue and motionless fluids. Thus the SEA technique significantly improves the accuracy of microscopic Po2 measurements in the microcirculation using the PQM.

  8. [Experimental branch vein occlusion: the effect of carbogen breathing on preretinal PO2].

    Science.gov (United States)

    Pournaras, J-A C; Poitry, S; Munoz, J-L; Pournaras, C J

    2003-10-01

    To evaluate the variations in preretinal PO2 in normal and in ischemic postexperimental branch vein occlusion (BRVO) retinal areas during normoxia, hyperoxia (100% O2) and carbogen (95% O2, 5% CO2) breathing. Preretinal PO2 measurements were obtained in intervascular retinal areas far from the retinal vessels of 13 anesthetized miniature pigs with oxygen-sensitive microelectrodes (10 microm tip diameter) introduced through the vitreous cavity by a micromanipulator. The microelectrode tip was placed at 50 microm from the vitreoretinal interface in the preretinal vitreous. PO2 was measured continuously for 10 minutes in systemic normoxia, hyperoxia (100% O2 breathing) and carbogen (95% O2, 5% CO2) breathing. A BRVO was induced with an argon green laser, and oxygen measurements were repeated in normoxia, hyperoxia and carbogen breathing. In hyperoxia, preretinal PO2 remained almost constant in both normal retinas (DeltaPO2=1.33 mmHg +/- 3.39; n=13) and ischemic retinas (DeltaPO2=3.73 mmHg +/- 2.84; n=8), although systemic PaO2 significantly increased. Carbogen breathing induced a significant increase in systemic PaO2 and PaCO2. Furthermore, it significantly increased preretinal PO2: DeltaPO2=23.05 mmHg +/- 17.06 (n=12) in normal retinas, and DeltaPO2=22.54 mmHg +/- 5.96 (n=6) in ischemic retinal areas. Systemic hyperoxia does not increase preretinal PO2 significantly in normal and ischemic post-BRVO retinal areas of miniature pigs, as hyperoxia induces a decrease in the retinal blood flow. Carbogen breathing significantly increases preretinal PO2 in normal and in ischemic post-BRVO retinal areas. This effect is probably due to the vasodilatation of the retinal arterioles induced by the intravascular PaCO2 increase.

  9. Conductivity of Composite Material Based on System NdPO4·nH2OCsH2PO4

    DEFF Research Database (Denmark)

    Anfimova, Tatiana; Bjerrum, Niels J.; Li, Qingfeng

    2013-01-01

    The goal of the present study was to obtain a comprehensive knowledge about synthesis conditions, structure, thermal behavior and conductivity properties of neodymiumorthophosphates in order to analyze of use this material in intermediate temperature fuel cells due to their thermal and chemical...... stability properties.The impedance spectroscopy technique (IS) was used to measure the conductivity. The conductivity of composites observed to be lower than conductivity of pure CsH2PO4 but had improved sufficiently conductivity of pure NdPO4·nH2O...

  10. High efficient multifunctional Ag_3PO_4 loaded hydroxyapatite nanowires for water treatment

    International Nuclear Information System (INIS)

    Li, Yaling; Zhou, Hangyu; Zhu, Genxing; Shao, Changyu; Pan, Haihua; Xu, Xurong; Tang, Ruikang

    2015-01-01

    Highlights: • The multifunctional Ag_3PO_4 loaded hydroxyapatite (HAP) nanowires were synthesized via a facile in-situ precipitation method. • By optimizing the initial concentration of AgNO_3, the well-distributed Ag_3PO_4/HAP composites could be achieved. • The Ag_3PO_4/HAP composites showed excellent photocatalytic performance for the decomposition of dyes under visible light irradiation. • The maximum absorption capacity of the Ag_3PO_4/HAP composites for Pb(II) was 250 mg/g, approximately three times as that of pure HAP. • The Ag_3PO_4/HAP composites also exhibited excellent antibacterial activities even at relative low concentrations. - Abstract: Organic, inorganic, and biological pollutants are typical water contaminants and they seriously affect water quality. In this study, we suggested that a novel multifunctional Ag_3PO_4 loaded hydroxyapatite (HAP) material can remove the typical pollutants from water. The Ag_3PO_4/HAP composites were synthesized facilely via in-situ precipitation of Ag_3PO_4 on the pre-existing HAP nanowires. By optimizing the composition of Ag_3PO_4 and HAP, the material could achieve an optimal photocatalytic activity to decompose rhodamine B (RhB), methyl orange (MO) and methylene blue (MB) under visible light irradiations with enhanced pH stability. Besides, the adsorption of Pb(II) on the Ag_3PO_4/HAP reached a maximum capacity of 250 mg/g and this value was approximately three times as that of pure HAP. Furthermore, the composite material exhibited excellent antibacterial activities towards gram-negative bacterium (Escherichia coli) and gram-positive bacterium (Stphylococcus aureus). The results highlighted the cooperative effect between Ag_3PO_4 and hydroxyapatite (HAP). The simultaneous removals of dyes, toxic metal ions, and bacteria with a high efficiency followed an easy approach for the purification of contaminated water via the rationally designed material, in which the Ag_3PO_4/HAP composite might be developed

  11. Experimental Evaluation of the Transport Mechanisms of PoIFN-α in Caco-2 Cells

    Directory of Open Access Journals (Sweden)

    Xin Liu

    2017-11-01

    Full Text Available For the development of an efficient intestinal delivery system for Porcine interferon-α (PoIFN-α, the understanding of transport mechanisms of which in the intestinal cell is essential. In this study, we investigated the absorption mechanisms of PoIFN-α in intestine cells. Caco-2 cells and fluorescein isothiocyanate-labeled (FITC-PoIFN-α were used to explore the whole transport process, including endocytosis, intracellular trafficking, exocytosis, and transcytosis. Via various techniques, the transport pathways of PoIFN-α in Caco-2 cells and the mechanisms were clarified. Firstly, the endocytosis of PoIFN-α by Caco-2 cells was time, concentration and temperature dependence. And the lipid raft/caveolae endocytosis was the most likely endocytic pathway for PoIFN-α. Secondly, both Golgi apparatus and lysosome were involved in the intracellular trafficking of PoIFN-α. Thirdly, the treatment of indomethacin resulted in a significant decrease of exocytosis of PoIFN-α, indicating the participation of cyclooxygenase. Finally, to evaluate the efficiency of PoIFN-α transport, the transepithelial electrical resistance (TEER value was measured to investigate the tight junctional integrity of the cell monolayers. The fluorescence microscope results revealed that the transport of PoIFN-α across the Caco-2 cell monolayers was restricted. In conclusion, this study depicts a probable picture of PoIFN-α transport in Caco-2 cells characterized by non-specificity, partial energy-dependency and low transcytosis.

  12. Bioassay of 210Po in human urine and internal contamination of man

    International Nuclear Information System (INIS)

    Carvalho, F.P.; Oliveira, J.M.

    2009-01-01

    The deliberate poisoning of A. Litvinenko in London in late 2006 with 210 Po, attracted attention to the difficulties in identifying internal contamination with alpha emitting radionuclides and to the limited knowledge available on the cycling of many naturally occurring radioisotopes in the body and their baseline concentration values in humans. To cope with the emergency caused by the spread of high 210 Po activity, which contaminated several people and places in London, we were called upon to analyze urine samples in potentially contaminated people. A reference group of adult humans was also selected for determination of baseline 210 Po values to be used for comparative purposes. Concentrations of 210 Po in urine samples from three Portuguese citizens that have been at contaminated places, in London, ranged from 2.3 to 4.1 mBq x L -1 while in the reference group 210 Po concentrations ranged from 0.5 to 4.8 mBq x L -1 . Analytical quality of results was ensured through participation in an international inter laboratory comparison exercise on 210 Po determination in aqueous samples. Results indicated that people potentially exposed to 210 Po in London were not internally contaminated with the radionuclide used as a poisoning agent, and the levels of this radionuclide measured in the urine were similar to the naturally occurring levels in the reference group. Polonium levels in urine and in man are discussed in the light of 210 Po levels in the human diet. (author)

  13. Characterization of quasi-one-dimensional S=1/2 Heisenberg antiferromagnets Sr2Cu(PO4)2 and Ba2Cu(PO4)2 with magnetic susceptibility, specific heat, and thermal analysis

    International Nuclear Information System (INIS)

    Belik, A.A.; Azuma, M.; Takano, M.

    2004-01-01

    Properties of Sr 2 Cu(PO 4 ) 2 and Ba 2 Cu(PO 4 ) 2 having [Cu(PO 4 ) 2 ] ∞ linear chains in their structures with Cu-O-P-O-Cu linkages were studied by magnetic susceptibility (T=2-400 K, H=100 Oe) and specific heat measurements (T=0.45-21 K). Magnetic susceptibility versus temperature curves, χ(T), showed broad maxima at T M =92 K for Sr 2 Cu(PO 4 ) 2 and T M =82 K for Ba 2 Cu(PO 4 ) 2 characteristic of quasi-one-dimensional systems. The χ(T) data were excellently fitted by the spin susceptibility curve for the uniform S=1/2 chain (plus temperature-independent and Curie-Weiss terms) with g=2.153(4) and J/k B =143.6(2) K for Sr 2 Cu(PO 4 ) 2 and g=2.073(4) and J/k B =132.16(9) K for Ba 2 Cu(PO 4 ) 2 (Hamiltonian H=JΣS i S i+1 ). The similar J/k B values were obtained from the specific heat data. No anomaly was observed on the specific heat from 0.45 to 21 K for both compounds indicating that the temperatures of long-range magnetic ordering, T N , were below 0.45 K. Sr 2 Cu(PO 4 ) 2 and Ba 2 Cu(PO 4 ) 2 are an excellent physical realization of the S=1/2 linear chain Heisenberg antiferromagnet with k B T N /J 2 CuO 3 (k B T N /J∼0.25%) and γ-LiV 2 O 5 (k B T N /J 2 Cu(PO 4 ) 2 and Ba 2 Cu(PO 4 ) 2 were stable in air up to 1280 and 1150 K, respectively

  14. Sky Fest: A Model of Successful Scientist Participation in E/PO

    Science.gov (United States)

    Dalton, H.; Shipp, S. S.; Shaner, A. J.; LaConte, K.; Shupla, C. B.

    2014-12-01

    Participation in outreach events is an easy way for scientists to get involved with E/PO and reach many people with minimal time commitment. At the Lunar and Planetary Institute (LPI) in Houston, Texas, the E/PO team holds Sky Fest outreach events several times a year. These events each have a science content theme and include several activities for children and their parents, night sky viewing through telescopes, and scientist presentations. LPI scientists have the opportunity to participate in Sky Fest events either by helping lead an activity or by giving the scientist presentation (a short lecture and/or demonstration). Scientists are involved in at least one preparation meeting before the event. This allows them to ask questions, understand what activity they will be leading, and learn the key points that they should be sharing with the public, as well as techniques for effectively teaching members of the public about the event topic. During the event, each activity is run by one E/PO specialist and one scientist, enabling the scientist to learn about effective E/PO practices from the E/PO specialist and the E/PO specialist to get more science information about the event topic. E/PO specialists working together with scientists at stations provides a more complete, richer experience for event participants. Surveys of event participants have shown that interacting one-on-one with scientists is often one of their favorite parts of the events. Interviews with scientists indicated that they enjoyed Sky Fest because there was very little time involved on their parts outside of the actual event; the activities were created and/or chosen by the E/PO professionals, and setup for the events was completed before they arrived. They also enjoyed presenting their topic to people without a background in science, and who would not have otherwise sought out the information that was presented.

  15. Cation mobility in NASICON compounds Li1-xZr2-xNbx(PO4)3 and Li1+xZr2-xScx(PO4)3

    International Nuclear Information System (INIS)

    Stenina, I.A.; Yaroslavtsev, A.B.; Aliev, A.D.; Antipov, E.V.; Velikodnyj, Yu.A.; Rebrov, A.I.

    2002-01-01

    Compounds featuring NASICON structure of the composition Li 1-x Zr 2-x Nb x (PO 4 ) 3 and Li 1+x Zr 2-x Sc x (PO 4 ) 3 were studied by the method of X-ray phase analysis and 7 Li and 31 P NMR. Structure of Li 0.8 Zr 1.8 Nb 0.2 (PO 4 ) 3 was refined on the basis of X-ray powder pattern. It is shown that cationic disordering in LiZr 2 (PO 4 ) 3 is stimulated both by cationic vacancies and interstitial atoms formation. The cationic vacancies are characterized by a higher mobility. The level of intrinsic disordering was estimated and the Frenkel constant for the compound was calculated [ru

  16. Measurement of airborne 218Po - A Bayesian approach

    International Nuclear Information System (INIS)

    Groer, P.G.; Lo, Y.

    1996-01-01

    The standard mathematical treatment of the buildup and decay of airborne radionuclides on a filter paper uses the solutions of the so-called bateman equations adapted to the sampling process. The equations can be interpreted as differential equations for the expectation of an underlying stochastic process, which describes the random fluctuations in the accumulation and decay of the sampled radioactive atoms. The process for the buildup and decay of airborne 218 Po can be characterized as an open-quotes immigration-death processclose quotes in the widely adopted, biologically based jargon. The probability distribution for the number of 218 Po atoms, accumulated after sampling time t, is Poisson. We show that the distribution of the number of counts, registered by a detector with efficiency ε during a counting period T after the end of sampling, it also Poisson, with mean dependent on ε,t,T, the flowrate and N o , the number of airborne 218 Po atoms per unit volume. This Poisson distribution was used to construct the likelihood given the observed number of counts. After inversion with Bayes' Theorem we obtained the posterior density for N o . This density characterizes the remaining uncertainty about the measured under of 218 Po atoms per unit volume of air. 6 refs., 3 figs., 1 tab

  17. Characterization of Carbon Composite LiMn1-xFexPO4 Cathodes

    International Nuclear Information System (INIS)

    Mishima, Y; Honda, S; Sadamura, H; Nakayama, N; Moriyoshi, C; Kuroiwa, Y

    2011-01-01

    The discharge capacities of 148 mAh/g (87 % theoretical value) at C/10 and 114mAh/g at 5C between 2.0 and 4.5 V at 25 deg. C were achieved for the carbon composite LiMn 0.8 Fe 0.2 PO 4 (C-LiMn 0.8 Fe 0.2 PO 4 ) cathode material of lithium-ion batteries (LIB), synthesized by a hydrothermal and annealing process. To improve the battery properties, we investigated the characteristics of C-LiMn 1-x Fe x PO 4 powders (x = 0.2 and 1) and the delithiated compound. While it was easier to form the homogeneous carbon layer on the surface of LiFePO 4 particles from the pyrolysis of sucrose, there was a tendency to form the particulate carbon on the LiMn 0.8 Fe 0.2 PO 4 particles. The lattice distortion of Mn 0.8 Fe 0.2 PO 4 was revealed by electron charge density study because of the Jahn-Teller active Mn 3+ ion associated with the phosphate ion. The surface and size of C- LiMn 0.8 Fe 0.2 PO 4 had to be modified because of these phenomena.

  18. Measuring interstitial pH and pO2 in mouse tumors.

    Science.gov (United States)

    Jain, Rakesh K; Munn, Lance L; Fukumura, Dai

    2013-07-01

    This protocol outlines methods to measure two extravascular parameters, interstitial pH and partial pressure of oxygen (pO2), in mouse tumors. The method for measuring interstitial pH uses fluorescence ratio imaging microscopy (FRIM) of the pH-sensitive fluorescent dye 2',7'-bis-(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF). The method for measuring interstitial pO2 is based on the oxygen-dependent quenching of the phosphorescence of albumin-bound palladium meso-tetra(4-carboxyphenyl)porphyrin, and can be used to measure microvascular as well as interstitial pO2. In addition, the two methods can be used sequentially to measure both pH and pO2 in the same tissues.

  19. Separation and electrodeposited of 210 Po

    International Nuclear Information System (INIS)

    Ordonez R, E.; Iturbe G, J.L.

    1991-12-01

    Presently work it was determined the selective separation of the 210 Po that is in an uraniferous mineral, by means of acid leaching of the mineral and the purification was carried out by means of partition chromatography whose stationary phase is 2-ethylhexyl phosphoric acid (D 2 EHPA), it has been possible to isolate the 210 Po of the rest of the radioactive elements that conform the family 4 N +2 , the optimal elutriation conditions of this element were settled down of manner of not dragging other radioelements. Another of the achievements presented in this communication has been the electrodeposition of this element has more than enough stainless steel discs with a superior yield to 95%. (Author)

  20. Structural and dielectric studies of LiNiPO4 and LiNi0.5Co0.5PO4 cathode materials for lithium-ion batteries

    Directory of Open Access Journals (Sweden)

    K. Vijaya Babu

    2016-09-01

    Full Text Available Olivine-type LiNiPO4 has been considered as a most competitive positive electrode active material for lithium-ion batteries. In the present paper, the LiNiPO4 and Co-doped LiNi0.5Co0.5PO4 are synthesized by solid-state reaction method under air atmosphere. All the X-ray diffraction peaks of both the compounds are indexed and it is found that the samples are well crystallized in orthorhombic olivine structure belonging to the space group Pnma. The crystallite size is calculated from the Scherrer formula and it is found to be 6.918 and 4.818 nm for pure and doped samples, respectively. The surface morphology and grain sizes of the materials are investigated through scanning electron microscope. Presence of preferred local cation environment is understood from Fourier transform infrared spectroscopy (FTIR studies. The conductivity and dielectric analysis of the samples are carried out at different temperatures and frequencies using the complex impedance spectroscopy technique. The electrical conductivity of LiNi0.5Co0.5PO4 is higher than that of pure LiNiPO4.

  1. Ultralong Lifespan and Ultrafast Li Storage: Single-Crystal LiFePO4 Nanomeshes.

    Science.gov (United States)

    Zhang, Yan; Zhang, Hui Juan; Feng, Yang Yang; Fang, Ling; Wang, Yu

    2016-01-27

    A novel LiFePO4 material, in the shape of a nanomesh, has been rationally designed and synthesized based on the low crystal-mismatch strategy. The LiFePO4 nanomesh possesses several advantages in morphology and crystal structure, including a mesoporous structure, its crystal orientation that is along the [010] direction, and a shortened Li-ion diffusion path. These properties are favorable for their application as cathode in Li-ion batteries, as these will accelerate the Li-ion diffusion rate, improve the Li-ion exchange between the LiFePO4 nanomesh and the electrolyte, and reduce the Li-ion capacitive behavior during Li intercalation. So the LiFePO4 nanomesh exhibits a high specific capacity, enhanced rate capability, and strengthened cyclability. The method developed here can also be extended to other similar systems, for instance, LiMnPO4 , LiCoPO4 , and LiNiPO4 , and may find more applications in the designed synthesis of functional materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Hexamethylenetetramine assisted hydrothermal synthesis of BiPO4 and its electrochemical properties for supercapacitors

    Science.gov (United States)

    Nithya, V. D.; Kalai Selvan, R.; Vasylechko, Leonid

    2015-11-01

    The well defined microstructures of BiPO4 were successfully synthesized by the facile hexamethylenetetramine (HMT) assisted hydrothermal method. The low temperature monoclinic BiPO4 structure with space group P21/n, were obtained from X-ray diffraction (XRD) for the pristine and HMT-assisted BiPO4 with 1, 3, 5 and 10 mmole concentration. A transformation from low temperature monazite-type phase to the high temperature SbPO4-type phase of BiPO4 was observed at the 10 mmole concentration. There was a variation in the morphology from polyhedron to octahedra-like and finally into cube shape upon an increase in concentration of HMT. The role of reaction time in the morphology of BiPO4 particles was investigated. The selected area electron diffraction (SAED) pattern elucidated the ordered dot pattern and the calculated d-spacing revealed the formation of BiPO4. An increased specific capacitance of HMT assisted materials (202 F/g) compared with pristine BiPO4 (89 F/g) at 5 mA/cm2 was observed upon morphological variation due to HMT addition.

  3. Determination of the PO2 temperature blood factor from oxygen dissociation curves.

    Science.gov (United States)

    Hérigault, R A; Soulard, C D; Teisseire, B P; Laurent, D N

    1983-01-01

    The variation with saturation of the temperature coefficient of PO2 in human blood (delta log PO2/delta T) was determined by continuous recording of the oxygen dissociation curve (ODC), at 37 degrees C and 25 degrees C, on the same blood samples. PCO2 and pH were held constant through an ODC run, and PCO2 was reduced at 25 degrees C to the value measured by anaerobic cooling of the same sample. delta log PO2/delta T was calculated from isosaturation points on the 37 and 25 degrees C curves. The temperature coefficient was also computed as an independent check on this method by determination of the effects of temperature (25, 30, 37 and 40 degrees C) on hemoglobin ligand interaction: fixed acid Bohr effect (delta log PO2/delta pH), carbamino-formation (delta log PO2/delta log PCO2) and hemoglobin oxygen affinity. The values of delta log PO2/delta T ratio obtained from the two different approaches were found to be in good agreement. The coefficient decreased when [H+] concentration was increased. A linear relationship between the Bohr factor and the temperature was found: delta log PO2/delta pH = 0.00267 T-0.520 (r = 0.85; n = 40) At 25 degrees C, the carbamino-formation was one order of magnitude lower than at 37 degrees C. Acid-base state and saturation value appeared to be major determinant factors for the temperature correction coefficient to be applied to blood PO2 values measured at standard (37 degrees C) temperature.

  4. Occurrence of 210Po and Biological Effects of Low-Level Exposure: The Need for Research

    Science.gov (United States)

    Wiemels, Joseph L.

    2012-01-01

    Background: Polonium-210 (210Po) concentrations that exceed 1 Bq/L in drinking-water supplies have been reported from four widely separated U.S. states where exposure to it went unnoticed for decades. The radionuclide grandparents of 210Po are common in sediments, and segments of the public may be chronically exposed to low levels of 210Po in drinking water or in food products from animals raised in contaminated areas. Objectives: We summarized information on the environmental behavior, biokinetics, and toxicology of 210Po and identified the need for future research. Methods: Potential linkages between environmental exposure to 210Po and human health effects were identified in a literature review. Discussion: 210Po accumulates in the ovaries where it kills primary oocytes at low doses. Because of its radiosensitivity and tendency to concentrate 210Po, the ovary may be the critical organ in determining the lowest injurious dose for 210Po. 210Po also accumulates in the yolk sac of the embryo and in the fetal and placental tissues. Low-level exposure to 210Po may have subtle, long-term biological effects because of its tropism towards reproductive and embryonic and fetal tissues where exposure to a single alpha particle may kill or damage critical cells. 210Po is present in cigarettes and maternal smoking has several effects that appear consistent with the toxicology of 210Po. Conclusions: Much of the important biological and toxicological research on 210Po is more than four decades old. New research is needed to evaluate environmental exposure to 210Po and the biological effects of low-dose exposure to it so that public health officials can develop appropriate mitigation measures where necessary. PMID:22538346

  5. Crystal structures of lazulite-type oxidephosphates TiIIITiIV3O3(PO4)3 and MIII4TiIV27O24(PO4)24 (MIII=Ti, Cr, Fe)

    International Nuclear Information System (INIS)

    Schoeneborn, M.; Glaum, R.; Reinauer, F.

    2008-01-01

    Single crystals of the oxidephosphates Ti III Ti IV 3 O 3 (PO 4 ) 3 (black), Cr III 4 Ti IV 27 O 24 (PO 4 ) 24 (red-brown, transparent), and Fe III 4 Ti IV 27 O 24 (PO 4 ) 24 (brown) with edge-lengths up to 0.3 mm were grown by chemical vapour transport. The crystal structures of these orthorhombic members (space group F2dd ) of the lazulite/lipscombite structure family were refined from single-crystal data [Ti III Ti IV 3 O 3 (PO 4 ) 3 : Z=24, a=7.3261(9) A, b=22.166(5) A, c=39.239(8) A, R 1 =0.029, wR 2 =0.084, 6055 independent reflections, 301 variables; Cr III 4 Ti IV 27 O 24 (PO 4 ) 24 : Z=1, a=7.419(3) A, b=21.640(5) A, c=13.057(4) A, R 1 =0.037, wR 2 =0.097, 1524 independent reflections, 111 variables; Fe III 4 Ti IV 27 O 24 (PO 4 ) 24 : Z=1, a=7.4001(9) A, b=21.7503(2) A, c=12.775(3) A, R 1 =0.049, wR 2 =0.140, 1240 independent reflections, 112 variables). For Ti III Ti IV O 3 (PO 4 ) 3 a well-ordered structure built from dimers [Ti III,IV 2 O 9 ] and [Ti IV,IV 2 O 9 ] and phosphate tetrahedra is found. The metal sites in the crystal structures of Cr 4 Ti 27 O 24 (PO 4 ) 24 and Fe 4 Ti 27 O 24 (PO 4 ) 24 , consisting of dimers [M III Ti IV O 9 ] and [Ti IV,IV 2 O 9 ], monomeric [Ti IV O 6 ] octahedra, and phosphate tetrahedra, are heavily disordered. Site disorder, leading to partial occupancy of all octahedral voids of the parent lipscombite/lazulite structure, as well as splitting of the metal positions is observed. According to Guinier photographs Ti III 4 Ti IV 27 O 24 (PO 4 ) 24 (a=7.418(2) A, b=21.933(6) A, c=12.948(7) A) is isotypic to the oxidephosphates M III 4 Ti IV 27 O 24 (PO 4 ) 24 (M III : Cr, Fe). The UV/vis spectrum of Cr 4 Ti 27 O 24 (PO 4 ) 24 reveals a rather small ligand-field splitting Δ o =14,370 cm -1 and a very low nephelauxetic ratio β=0.72 for the chromophores [Cr III O 6 ] within the dimers [Cr III Ti IV O 9 ]. - Graphical abstract: Single crystals of the oxidephosphates Ti III Ti IV 3 O 3 (PO 4 ) 3 (black), Cr III 4 Ti IV 27 O

  6. Po-210 and other radionuclides in terrestrial and freshwater environments

    Energy Technology Data Exchange (ETDEWEB)

    Gjelsvik, Runhild; Brown, Justin [eds.; Norwegian Radiation Protection Authority (Norway); Holm, Elis [Univ. of Lund (Sweden); Roos, Per [Risoe DTU (Denmark); Saxen, Ritva; Outola, Iisa [STUK - Radiation and Nuclear Safety Authority (Finland)

    2009-01-15

    This report provides new information on Po-210 (and where appropriate its grandparent Pb-210) behaviour in environmental systems including humans. This has primarily been achieved through measurements of Po-210 in aquatic and terrestrial environments that has led to the derivation of information on the levels of this radioisotope in plants, animals and the biotic components of their habitat (i.e. water, soil) providing basic information on transfer where practicable. For freshwater environments, Po-210 concentration ratios derived for freshwater benthic fish and bivalve mollusc were substantially different to values collated from earlier review work. For terrestrial environments, activity concentrations of Po-210 in small mammals (although of a preliminary nature because no correction was made for ingrowth from Pb-210) were considerably higher than values derived from earlier data compilations. It was envisaged that data on levels of naturally occurring radionuclides would render underpinning data sets more comprehensive and would thus allow more robust background dose calculations to be performed subsequently. By way of example, unweighted background dose-rates arising from internal distributions of Po-210 were calculated for small mammals in the terrestrial study. The biokinetics of polonium in humans has been studied following chronic and acute oral intakes of selected Po radioisotopes. This work has provided information on gastrointestinal absorption factors and biological retention times thus improving the database upon which committed effective doses to humans are derived. The information generated in the report, in its entirety, should be of direct relevance for both human and non-human impact assessments. (au)

  7. Po-210 and other radionuclides in terrestrial and freshwater environments

    International Nuclear Information System (INIS)

    Gjelsvik, Runhild; Brown, Justin; Roos, Per; Saxen, Ritva; Outola, Iisa

    2009-01-01

    This report provides new information on Po-210 (and where appropriate its grandparent Pb-210) behaviour in environmental systems including humans. This has primarily been achieved through measurements of Po-210 in aquatic and terrestrial environments that has led to the derivation of information on the levels of this radioisotope in plants, animals and the biotic components of their habitat (i.e. water, soil) providing basic information on transfer where practicable. For freshwater environments, Po-210 concentration ratios derived for freshwater benthic fish and bivalve mollusc were substantially different to values collated from earlier review work. For terrestrial environments, activity concentrations of Po-210 in small mammals (although of a preliminary nature because no correction was made for ingrowth from Pb-210) were considerably higher than values derived from earlier data compilations. It was envisaged that data on levels of naturally occurring radionuclides would render underpinning data sets more comprehensive and would thus allow more robust background dose calculations to be performed subsequently. By way of example, unweighted background dose-rates arising from internal distributions of Po-210 were calculated for small mammals in the terrestrial study. The biokinetics of polonium in humans has been studied following chronic and acute oral intakes of selected Po radioisotopes. This work has provided information on gastrointestinal absorption factors and biological retention times thus improving the database upon which committed effective doses to humans are derived. The information generated in the report, in its entirety, should be of direct relevance for both human and non-human impact assessments. (au)

  8. Interplay of tumor vascular oxygenation and tumor pO2 observed using near-infrared spectroscopy, an oxygen needle electrode, and 19F MR pO2 mapping.

    Science.gov (United States)

    Kim, Jae G; Zhao, Dawen; Song, Yulin; Constantinescu, Anca; Mason, Ralph P; Liu, Hanli

    2003-01-01

    This study investigates the correlation of tumor blood oxygenation and tumor pO(2) with respect to carbogen inhalation. After having refined and validated the algorithms for calculating hemoglobin concentrations, we used near-infrared spectroscopy (NIRS) to measure changes of oxygenated hemoglobin concentration (delta[HbO(2)]) and used an oxygen needle electrode and (19)F MRI for pO(2) measurements in tumors. The measurements were taken from Dunning prostate R3327 tumors implanted in rats, while the anesthetized rats breathed air or carbogen. The NIRS results from tumor measurements showed significant changes in tumor vascular oxygenation in response to carbogen inhalation, while the pO(2) electrode results showed an apparent heterogeneity for tumor pO(2) response to carbogen inhalation, which was also confirmed by (19)F MR pO(2) mapping. Furthermore, we developed algorithms to estimate hemoglobin oxygen saturation, sO(2), during gas intervention based on the measured values of delta[HbO(2)] and pO(2). The algorithms have been validated through a tissue-simulating phantom and used to estimate the values of sO(2) in the animal tumor measurement based on the NIRS and global mean pO(2) values. This study demonstrates that the NIRS technology can provide an efficient, real-time, noninvasive approach to monitoring tumor physiology and is complementary to other techniques, while it also demonstrates the need for an NIR imaging technique to study spatial heterogeneity of tumor vasculature under therapeutic interventions. Copyright 2003 Society of Photo-Optical Instrumentation Engineers

  9. AgI/Ag3PO4 hybrids with highly efficient visible-light driven photocatalytic activity

    International Nuclear Information System (INIS)

    Katsumata, Hideyuki; Hayashi, Takahiro; Taniguchi, Masanao; Suzuki, Tohru; Kaneco, Satoshi

    2015-01-01

    Highlights: • AgI/Ag 3 PO 4 hybrid was prepared via an in situ anion-exchange method. • AgI/Ag 3 PO 4 displays the excellent photocatalytic activity under visible light. • AgI/Ag 3 PO 4 readily transforms to be Ag@AgI/Ag 3 PO 4 system. • h + and O 2 ·− play the major role in the AO 7 decolorization over AgI/Ag 3 PO 4 . • The activity enhancement is ascribed to a Z-scheme system composed of Ag 3 PO 4 , Ag and AgI. - Abstract: Highly efficient visible-light-driven AgI/Ag 3 PO 4 hybrid photocatalysts with different mole ratios of AgI were prepared via an in situ anion-exchange method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) technique. Under visible light irradiation (>420 nm), the AgI/Ag 3 PO 4 photocatalysts displayed the higher photocatalytic activity than pure Ag 3 PO 4 and AgI for the decolorization of acid orange 7 (AO 7). Among the hybrid photocatalysts, AgI/Ag 3 PO 4 with 80% of AgI exhibited the highest photocatalytic activity for the decolorization of AO 7. X-ray photoelectron spectroscopy (XPS) results revealed that AgI/Ag 3 PO 4 readily transformed to be Ag@AgI/Ag 3 PO 4 system while the photocatalytic activity of AgI/Ag 3 PO 4 remained after 5 recycling runs. In addition, the quenching effects of different scavengers displayed that the reactive h + and O 2 ·− play the major role in the AO 7 decolorization. The photocatalytic activity enhancement of AgI/Ag 3 PO 4 hybrids can be ascribed to the efficient separation of electron–hole pairs through a Z-scheme system composed of Ag 3 PO 4 , Ag and AgI, in which Ag nanoparticles act as the charge separation center

  10. The sources and fate of (210)Po in the urban air: A review.

    Science.gov (United States)

    Długosz-Lisiecka, Magdalena

    2016-09-01

    The origin of (210)Po activity and its fluctuations in the air are discussed in this paper. In the case of atmospheric aerosol samples, a comparison of the (210)Po/(210)Pb and (210)Bi/(210)Pb activity ratios makes it possible not only to determine aerosol residence times but also to appraise the contribution of the unsupported (210)Po coming from other sources than (222)Rn decay, such as human industrial activities, especially coal combustion. A simple mathematical method makes it possible to observe the seasonal fluctuations of the anthropogenic excess of (210)Po in the urban air. The average doses of (210)Po intake with food (including drinking water) and inhalation of urban aerosols are usually lower than those from (210)Po intake by cigarette smokers and negligible in comparison to total natural radiation exposure. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Energetics of cobalt phosphate frameworks: α, β, and red NaCoPO4

    International Nuclear Information System (INIS)

    Le, So-Nhu; Eng, Hank W.; Navrotsky, Alexandra

    2006-01-01

    Thermal behavior, relative stability, and enthalpy of formation of α (pink phase), β (blue phase), and red NaCoPO 4 are studied by differential scanning calorimetry, X-ray diffraction, and high-temperature oxide melt drop solution calorimetry. Red NaCoPO 4 with cobalt in trigonal bipyramidal coordination is metastable, irreversibly changing to α NaCoPO 4 at 827 K with an enthalpy of phase transition of -17.4±6.9 kJ mol -1 . α NaCoPO 4 with cobalt in octahedral coordination is the most stable phase at room temperature. It undergoes a reversible phase transition to the β phase (cobalt in tetrahedra) at 1006 K with an enthalpy of phase transition of 17.6±1.3 kJ mol -1 . Enthalpy of formation from oxides of α, β, and red NaCoPO 4 are -349.7±2.3, -332.1±2.5, and -332.3±7.2 kJ mol -1 ; standard enthalpy of formation of α, β, and red NaCoPO 4 are -1547.5±2.7, -1529.9±2.8, and -1530.0±7.3 kJ mol -1 , respectively. The more exothermic enthalpy of formation from oxides of β NaCoPO 4 compared to a structurally related aluminosilicate, NaAlSiO 4 nepheline, results from the stronger acid-base interaction of oxides in β NaCoPO 4 (Na 2 O, CoO, P 2 O 5 ) than in NaAlSiO 4 nepheline (Na 2 O, Al 2 O 3 , SiO 2 ). - Graphical abstract: Relative stability of NaCoPO 4 polymorphs compared to the most stable phase, α NaCoPO 4

  12. Synthesis and Characterization of New Nickel Phosphates, ANi4(PO4)3 (A=K, Rb)

    International Nuclear Information System (INIS)

    Im, Yoonmi; Kim, Pilsoo; Yun, Hoseop

    2014-01-01

    Quaternary nickel orthophosphates, ANi 4 (PO 4 ) 3 (A=Alkali metals) have been extensively investigated because they show interesting properties such as ionic conductivities, optical, and magnetic behaviors. They are built up from NiO 6 octahedra and PO 4 tetrahedra. These basic building blocks are connected via common oxygen atoms to form the three-dimensional frameworks and the alkali metal ions reside in the empty space. For NaNi 4 (PO 4 ) 3 , two different structures have been reported and this can be caused by the different reaction conditions. While NaNi 4 (PO 4 ) 3 prepared as single crystals with the use of NaCl flux at 1373 K crystallizes in the space group Amam and show a partial disorder of one of the PO 4 tetrahedra, NaNi 4 (PO 4 ) 3 and KNi 4 (PO 4 ) 3 synthesized with alkali metal nitrate at 1073 K as powders adopt an ordered structure with the space group Pnnm. As far as we know, no structural studies of KNi 4 (PO 4 ) 3 from single crystal diffraction data have been reported yet and RbNi 4 (PO 4 ) 3 is a new compound. In this paper we report on the synthesis and structural investigations using single crystals of two nickel orthophosphates, KNi 4 (PO 4 ) 3 and RbNi 4 (PO 4 ) 3

  13. 210Pb and 210Po in Finnish cereals

    International Nuclear Information System (INIS)

    Turtiainen, Tuukka; Kostiainen, Eila; Hallikainen, Anja

    2011-01-01

    A survey was carried out on the activity concentrations of 210 Pb and 210 Po in cereal grains produced in Finland. The cereal species were wheat (Triticum aestivum), rye (Secale cereale), oats (Avena sativa) and barley (Hordeum vulgare), which account for 90% of the Finnish consumption of cereal products. The survey consisted of 18 flour and 13 unprocessed cereal samples and one hulled grain sample from 22 flour mills. According to the results, the mean 210 Pb/ 210 Po concentrations in wheat grains, wheat flour, rye flour, oat grains and barley grains were 0.29, 0.12, 0.29, 0.36 and 0.36 Bq kg -1 , respectively. Combined with the consumption rates of the products, we assess that the mean effective doses from 210 Pb and 210 Po in cereal products for the adult male and female population are 22 and 17 μSv per year, respectively.

  14. Annual effective dose of 210Po from sea food origin (Oysters and Mussels) in Korea

    International Nuclear Information System (INIS)

    Cho, Bo Eum; Hong, Gi Hoon; Kim, Suk Hyun; Lee, Hyun Mi

    2016-01-01

    Ingestion of 210 Po laden seafood accounts for a substantial amount of the effective dose of 210 Po. Among seafood items, mollusks, especially domestically produced oysters and mussels, are highly enriched in 210 Po and are consumed in large quantities in Korea. Oysters and mussels around the Korean coasts were collected from major farm areas in November 2013. Samples were spiked with an aliquot of 210 Po as a yield tracer, and they were digested with 6 mol·L -1 HNO 3 and H 2 O 2 . The 210 Po and 209 Po were spontaneously deposited onto a silver disc in an acidic solution of 0.5 mol·L -1 HCl and measured using an alpha spectrometer. The activity concentrations of 210 Pb and 210 Po were decay corrected to the sampling date, accounting for the possible in-growth and decay of 210 Po. 210 Po activity concentrations in oysters were in a range from 41.3 to 206 Bq·(kg-ww -1 and mussels in a range from 42.9 to 46.7 Bq·(kg-ww) -1 . The 210 Po activity concentration of oysters in the turbid Western coast was higher than the Southern coast. The 210 Po activity concentration of the oysters was positively correlated (R2=0.89) with those of the suspended particulate matter in the surface water. The calculated annual effective dose of 210 Po from oysters and mussels consumed by the Korean population was 21-104 and 5.01-5.46 μSv·y -1 . The combined effective dose due to the consumption of oysters and mussels appears to account for about 35±19% of that arising from seafood consumption in the Korean population. The annual effective dose of 210 Po for oysters in the Korean population was found to be higher than other countries. The total annual effective dose of 210Po 210 Po due to consumption of oysters and mussels consumed in Korea was found to be 76±42 μSv·y -1 , accounting for 28±16% of the total effective dose of 210 Po from food in Korea

  15. Study of the solubility, viscosity and density in Na+, Zn2+/Cl− − H2O, Na+ − Zn2+ − (H2PO2)− − H2O, Na+, Cl−/(H2PO2)− − H2O, and Zn2+, Cl−/(H2PO2)− − H2O ternary systems, and in Na+, Zn2+/Cl−, (H2PO2)−//H2O reciprocal quaternary system at 273.15 K

    International Nuclear Information System (INIS)

    Adiguzel, Vedat; Erge, Hasan; Alisoglu, Vahit; Necefoglu, Hacali

    2014-01-01

    Highlights: • The physicochemical properties of ternary and one quaternary have been studied. • Reciprocal quaternary systems’ solubility and phase equilibrium have been studied. • In all systems the solid phases have been found. • It was found that Zn(H 2 PO 2 ) 2 salt contains 70% of the general crystallization field. - Abstract: The solubility and the physicochemical properties (density, viscosity) in the Na-Zn- Cl-H 2 O), (Na + Zn + H 2 PO 2 + H 2 O), (Na + Cl + H 2 PO 2 + H 2 O), and (Zn + Cl + H 2 PO 2 + H 2 O) ternaries, and in Na + , Zn 2+ /Cl − , (H 2 PO 2 ) − //H 2 O reciprocal quaternary systems at T = 273.15 K were investigated by using the isothermal method. The diagrams of ternary salts systems, (NaCl + ZnCl 2 + H 2 O), (NaCl + NaH 2 PO 2 + H 2 O), (NaH 2 PO 2 + Zn(H 2 PO 2 ) 2 + H 2 O), (ZnCl 2 + Zn(H 2 PO 2 ) 2 + H 2 O), are plotted in figures 1–4. However, whole ions of reciprocal quaternary salt systems are plotted in figure 5. Additionally, the density and viscosity values of ternary systems vs. their corresponding composition values in weight per cent are plotted in figures 6–10. At the (i) (ZnCl 2 + Zn(H 2 PO 2 ) 2 + H 2 O), (ii) (NaCl + ZnCl 2 + H 2 O), (iii) (NaCl + NaH 2 PO 2 + H 2 O), (iv) (NaH 2 PO 2 + Zn(H 2 PO 2 ) 2 + H 2 O) ternary systems the solid phase compositions have been determined as: (i) Zn(H 2 PO 2 ) 2 ⋅ H 2 O, Zn(H 2 PO 2 ) 2 , ZnCl 2 ⋅ 2H 2 O, (ii) NaCl, 2NaCl ⋅ ZnCl 2 ⋅ 2H 2 O, and ZnCl 2 ⋅ 2H 2 O, (iii) NaCl and NaH 2 PO 2 ⋅ H 2 O, (iv) Zn(H 2 PO 2 ) 2 ⋅ H 2 O and NaH 2 PO 2 ⋅ H 2 O, respectively. On the other hand reciprocal quaternary system was observed as: ZnCl 2 ⋅ 2H 2 O, 2NaCl ⋅ ZnCl 2 ⋅ 2H 2 O, Zn(H 2 PO 2 ) 2 ⋅ H 2 O, NaH 2 PO 2 ⋅ H 2 O, NaCl. According to results, the least soluble salt was Zn(H 2 PO 2 ) 2 . The crystallization field of this salt, being the largest in comparison with those of other salts, occupied 70% of the general crystallization field

  16. Crystal structures and magnetic properties of iron (III)-based phosphates: Na4NiFe(PO4)3 and Na2Ni2Fe(PO4)3

    International Nuclear Information System (INIS)

    Essehli, Rachid; Bali, Brahim El; Benmokhtar, Said; Bouziane, Khalid; Manoun, Bouchaib; Abdalslam, Mouner Ahmed; Ehrenberg, Helmut

    2011-01-01

    Graphical abstract: A perspective view of the Na 2 Ni 2 Fe(PO 4 ) 3 structure along the [0 0 1] direction. Both compounds seem to exibit antiferromagnetic interactions between magnetic entities at low temperature. Display Omitted Research highlights: → Nasicon and Alluaudite compounds, Iron(III)-based phosphates, Crystal structures of Na 4 NiFe(PO 4 ) 3 and Na 2 Ni 2 Fe(PO 4 ) 3 . → Magnetism behaviours of Na 4 NiFe(PO 4 ) 3 and Na 2 Ni 2 Fe(PO 4 ) 3 . → Antiferromagnetism interactions. → Mossbauer spectroscopy. - Abstract: Crystal structures from two new phosphates Na 4 NiFe(PO 4 ) 3 (I) and Na 2 Ni 2 Fe(PO 4 ) 3 (II) have been determined by single crystal X-ray diffraction analysis. Compound (I) crystallizes in a rhombohedral system (S. G: R-3c, Z = 6, a = 8.7350(9) A, c = 21.643(4) A, R 1 = 0.041, wR 2 =0.120). Compound (II) crystallizes in a monoclinic system (S. G: C2/c, Z = 4, a = 11.729(7) A, b = 12.433(5) A, c = 6.431(2) A, β = 113.66(4) o , R 1 = 0.043, wR 2 =0.111). The three-dimensional structure of (I) is closely related to the Nasicon structural type, consisting of corner sharing [(Ni/Fe)O 6 ] octahedra and [PO 4 ] tetrahedra forming [NiFe(PO 4 ) 3 ] 4+ units which align in chains along the c-axis. The Na + cations fill up trigonal antiprismatic sites within these chains. The crystal structure of (II) belongs to the alluaudite type. Its open framework results from [Ni 2 O 10 ] units of edge-sharing [NiO 6 ] octahedra, which alternate with [FeO 6 ] octahedra that form infinite chains. Coordination of these chains yields two distinct tunnels in which site Na + . The magnetization data of compound (I) reveal antiferromagnetic (AFM) interactions by the onset of deviations from a Curie-Weiss behaviour at low temperature as confirmed by Moessbauer measurements performed at 4.2 K. The corresponding temperature dependence of the reciprocal susceptibility χ -1 follows a typical Curie-Weiss behaviour for T > 105 K. A canted AFM state is proposed for

  17. Determination of 210Pb and 210Po in cigarette tobacco

    International Nuclear Information System (INIS)

    Peres, Ana Claudia

    1999-01-01

    Cigarette smoking is one of the important pathways that could contribute to enhance the radiation dose to man, due to the relatively large concentrations of 210 Pb and 210 Po found in tobacco leaves. In this work, concentrations of these two radionuclides were determined in eight of the most commercialized cigarette brands produced in Brazil. The samples analyzed were bought randomly in the market. The 210 Pb was determined by counting the beta activity of the 210 Bi in a gas flow proportional detector, after radiochemical separation and precipitation of the PbCr0 4 . The 210 Po was determined by alpha spectrometry, using a surface barrier detector, after radiochemical separation and spontaneous deposition of Po in copper disk. The results showed concentrations ranging from 11,9 to 30,2 mBq per gram of dry tobacco for 210 Pb and from 10,9 to 27,4 mBq per gram of dry tobacco for 210 Po. (author)

  18. High pressure experimental studies on Na3Fe(PO4)(CO3) and Na3Mn(PO4)(CO3): Extensive pressure behaviors of carbonophosphates family

    Science.gov (United States)

    Gao, Jing; Huang, Weifeng; Wu, Xiang; Qin, Shan

    2018-04-01

    Carbon-bearing phases in the Earth's interior have profound implications for the long-term Earth carbon cycle. Here we investigate high-pressure behaviors of carbonophosphates bonshtedtite Na3Fe(PO4)(CO3) and sidorenkite Na3Mn(PO4)(CO3) in diamond anvil cells up to ∼12 GPa at room temperature. Modifications in in situ synchrotron X-ray diffraction patterns and Raman spectra confirm the structural stability of carbonophosphates within the pressure region. Fitting the third-order Birch-Murnaghan equation of state to the volume compression curve, the isothermal bulk modulus parameters are obtained to be K0 = 56(1) GPa, K0' = 3.3(1), V0 = 303.3(3) Å3 for Na3Fe(PO4)(CO3) and K0 = 54(1) GPa, K0' = 3.4(1), V0 = 313.4(2) Å3 for Na3Mn(PO4)(CO3). Crystallographic axes exhibit an elastic anisotropy with a more compressible c-axis relative to the ab-plane. An inverse linear correlation between the K0 value and the ionic radius of M2+ (M = Mg, Fe, Mn) is well determined for carbonophosphates. The pressure-dependence responsiveness of [PO4] and [CO3] in carbonophosphates show a negative relationship to the M2+ radius. We also discussed the effect of [PO4] group on the structural variations and high-pressure behaviors of carbonates. Furthermore, the geochemical properties of carbonophosphates hold implications to diamond genesis.

  19. Surfactant mediated hydrothermal synthesis, characterization and luminescent properties of GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} @ GdPO{sub 4} core shell nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Khajuria, Heena; Ladol, Jigmet; Khajuria, Sonika; Shah, Mohd Syed; Sheikh, H.N., E-mail: hnsheikh@rediffmail.com

    2016-08-15

    Highlights: • Core shell nanorods were synthesised by surfactant assisted hydrothermal method. • Morphology of core shell nanorods resembles those of core nanorods indicating coating of shell on cores. • More uniform and non-aggregated core shell nanorods were prepared in presence of surfactants. • Surfactant assisted prepared core shell nanorods show intense emission as compared to uncoated core nanorods. - Abstract: Core shell GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} @ GdPO{sub 4} nanorods were synthesized via hydrothermal route in the presence of different surfactants [cetyltrimethyl ammonium bromide (CTAB) and Sodium dodecyl sulphate (SDS)]. The nanorods were characterized by powder X-ray diffraction (PXRD), fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and photoluminescence (PL) studies. The X-ray diffraction results indicate good crystallinity and effective doping in core and core shell nanorods. SEM and TEM micrographs show that all of the as prepared gadolinium phosphate products have rod like shape. The compositional analysis of GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} core was done by EDS. The emission intensity of the GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} @ GdPO{sub 4} core shell increased significantly with respect to those of GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} core nanorods. The effect of surfactant on the uniformity, thickness and luminescence of the core shell nanorods was investigated.

  20. Rat muscle microvascular PO2 kinetics during the exercise off-transient.

    Science.gov (United States)

    McDonough, P; Behnke, B J; Kindig, C A; Poole, D C

    2001-05-01

    Dependent upon the relative speed of pulmonary oxygen consumption (VO2) and blood flow (Q) kinetics, the exercise off-transient may represent a condition of sub- or supra-optimal perfusion. To date, there are no direct measurements of the dynamics of the VO2/Q relationship within the muscle at the onset of the work/recovery transition. To address this issue, microvascular PO2 (PO2,m) dynamics were studied in the spinotrapezius muscles of 11 female Sprague-Dawley rats (weight approximately 220 g) during and following electrical stimulation (1 Hz) to assess the adequacy of Q. relative to VO2 post exercise. The exercise blood flow response (radioactive microspheres: muscle Q increased approximately 240 %), and post-exercise arterial blood pH (7.40 +/- 0.02) and blood lactate (1.3 +/- 0.4 mM x l(-1)) values were consistent with moderate-intensity exercise. Recovery PO2,m (i.e. off-transient) rose progressively until baseline values were achieved ((Delta)end-recovery exercise PO2,m, 14.0 +/- 1.9 Torr) and at no time fell below exercising PO2,m. The off-transient PO2,m was well fitted by a dual exponential model with both fast (tau = 25.4 +/- 5.1 s) and slow (tau = 71.2 +/- 34.2 s) components. Furthermore, there was a pronounced delay (54.9 +/- 10.7 s) before the onset of the slow component. These data, obtained at the muscle microvascular level, support the notion that muscle VO2 falls with faster kinetics than muscle Q during the off-transient, such that PO2,m increases systematically, though biphasically, during recovery.

  1. $^{206}$ Po sources for production and release studies relevant for high power spallation targets

    CERN Multimedia

    The knowledge of the evaporation behaviour of Po is of essential importance for several scientific and technological applications, like accelerator driven systems (ADS) or the LIEBE project at CERN-ISOLDE. Fundamental investigations on the experimental conditions for the formation of volatile Po species as well as on the chemical composition of the volatile compounds are necessary for a safe operation of such facilities. $^{206}$Po, a mainly $\\gamma$- ray-emitting Po isotope with a half-life of 8.8 d, is best suited for model studies, due to the lower radiation hazard compared to the longer-lived $\\alpha$-emitting isotopes $^{208-210}$Po as well as the easy-to-measure $\\gamma$-ray emission. We propose the production of $^{206}$Po samples in several matrices via the implantation of its precursor $^{210}$Fr into selected metal foils at CERN-ISOLDE. Using these samples, experiments will be carried out at PSI studying the volatilization of Po from different matrices under varying chemical conditions.

  2. Variation of 210Po daily urinary excretion for male subjects at environmental level

    International Nuclear Information System (INIS)

    Hoelgye, Z.; Hyza, M.; Mihalik, J.; Rulik, P.; Skrkal, J.

    2015-01-01

    210 Po was determined in 24-h urine of seven healthy males from Prague, Czech Republic, for ten consecutive days. The results show that for each volunteer, the urinary excretion of 210 Po changed only little from day to day in the studied time period. For two volunteers, the difference in the daily excreted 210 Po activity for two consecutive days was not significant, given the 95 % confidence interval (two sigma) of the activity measurements. The same is valid for the excretion data of the other volunteers, except for some days where the differences were slightly higher. The range of daily urinary excretion of 210 Po of each volunteer in the studied time period was quite narrow. Among the volunteers, the maximum daily urinary excretion value of 210 Po was at most about a factor of 2.5 higher than the lowest excretion value. An attempt to explain the observed small inter-individual variability of 210 Po excretion in daily urine is made. (orig.)

  3. Origin of Activity and Stability Enhancement for Ag3PO4 Photocatalyst after Calcination

    Directory of Open Access Journals (Sweden)

    Pengyu Dong

    2016-11-01

    Full Text Available Pristine Ag3PO4 microspheres were synthesized by a co-precipitation method, followed by being calcined at different temperatures to obtain a series of calcined Ag3PO4 photocatalysts. This work aims to investigate the origin of activity and stability enhancement for Ag3PO4 photocatalyst after calcination based on the systematical analyses of the structures, morphologies, chemical states of elements, oxygen defects, optical absorption properties, separation and transfer of photogenerated electron-hole pairs, and active species. The results indicate that oxygen vacancies (VO˙˙ are created and metallic silver nanoparticles (Ag NPs are formed by the reaction of partial Ag+ in Ag3PO4 semiconductor with the thermally excited electrons from Ag3PO4 and then deposited on the surface of Ag3PO4 microspheres during the calcination process. Among the calcined Ag3PO4 samples, the Ag3PO4-200 sample exhibits the best photocatalytic activity and greatly enhanced photocatalytic stability for photodegradation of methylene blue (MB solution under visible light irradiation. Oxygen vacancies play a significantly positive role in the enhancement of photocatalytic activity, while metallic Ag has a very important effect on improving the photocatalytic stability. Overall, the present work provides some powerful evidences and a deep understanding on the origin of activity and stability enhancement for the Ag3PO4 photocatalyst after calcination.

  4. Highly-efficient photocatalytic degradation of methylene blue by PoPD-modified TiO 2 nanocomposites due to photosensitization-synergetic effect of TiO2 with PoPD.

    Science.gov (United States)

    Yang, Chuanxi; Dong, Wenping; Cui, Guanwei; Zhao, Yingqiang; Shi, Xifeng; Xia, Xinyuan; Tang, Bo; Wang, Weiliang

    2017-06-21

    Poly-o-phenylenediamine modified TiO 2 nanocomposites were successfully synthesized via an 'in situ' oxidative polymerization method. The modified nanocomposites were characterized by BET, XRD, TEM, FT-IR, TGA, XPS, EA and UV-Vis DRS. The photocatalytic degradation of methylene blue was chosen as a model reaction to evaluate the photocatalytic activities of TiO 2 and PoPD/TiO 2 . The results indicated that PoPD/TiO 2 nanocomposites exhibited good photocatalytic activity and stability. The photocatalytic activity of PoPD/TiO 2 increased as the initial pH increased because of electrostatic adsorption between the photocatalyst and MB as well as the generation of ·OH, whereas it exhibited an earlier increasing and later decreasing trend as the concentration of the photocatalyst increased owing to the absorption of visible light. The photocatalytic stability of the PoPD/TiO 2 nanocomposite was dependent on the stability of its structure. Based on radical trapping experiments and ESR measurements, the origin of oxidizing ability of PoPD/TiO 2 nanocomposites on photocatalytic degradation of MB was proposed, which taking into account of ·OH and ·O 2 - were the first and second important ROS, respectively. The possible photocatalytic mechanism and photocatalytic activity enhanced mechanism has been proposed, taking into account the photosensitization effect and synergetic effect of TiO 2 with PoPD.

  5. 210Po and 210Pb activity concentration in the coral bands of Pulau Tuba, Langkawi

    International Nuclear Information System (INIS)

    Lee Jen Nie; Che Abdul Rahim Mohamed; Zaharuddin Ahmad

    2007-01-01

    We examined the concentrations of 210 Po and 210 Pb in each layers of coral banding of coral skeletons. Concentrations of 210 Po and 210 Pb in massive corals (i.e. Porites, Favites, Platygyra and Goniostrea) from Pulau Tuba, Langkawi were measured using the Alpha-Spectrometry. The concentrations of 210 Po were higher than the concentrations of 210 Pb. This may due to continuing source of 210 Po from 210 Pb. Highest concentration on 210 Po in coral banding was 48.30 ± 28.53 Bq/ kg, meanwhile for 210 Pb was 12.86 ± 5.80 Bq/ kg. The ratios of 210 Po/ 210 Pb were in the range of 2.21 to 5.49. The variation activity concentrations of 210 Po and 210 Pb in the coral bands are important to consider in using coral as retrospective study of environmental changes. The coral can represent the total of 210 Po and 210 Pb in the surrounding water for the past few years. (author)

  6. Tools for Scientist Engagement in E/PO: NASA SMD Community Workspace and Online Resources

    Science.gov (United States)

    Dalton, H.; Shipp, S. S.; Grier, J.; Gross, N. A.; Buxner, S.; Bartolone, L.; Peticolas, L. M.; Woroner, M.; Schwerin, T. G.

    2014-12-01

    The Science Mission Directorate (SMD) Science Education and Public Outreach (E/PO) Forums are here to help you get involved in E/PO! The Forums have been developing several online resources to support scientists who are - or who are interested in becoming - involved in E/PO. These include NASA Wavelength, EarthSpace, and the SMD E/PO online community workspace. NASA Wavelength is the one-stop shop of all peer-reviewed NASA education resources to find materials you - or your audiences - can use. Browse by audience (pre-K through 12, higher education, and informal education) or topic, or choose to search for something specific by keyword and audience. http://nasawavelength.org. EarthSpace, an online clearinghouse of Earth and space materials for use in the higher education classroom, is driven by a powerful search engine that allows you to browse the collection of resources by science topic, audience, type of material or key terms. All materials are peer-reviewed before posting, and because all submissions receive a digital object identifier (doi), submitted materials can be listed as publications. http://www.lpi.usra.edu/earthspace. The SMD E/PO online community workspace contains many resources for scientists. These include one-page guides on how to get involved, tips on how to make the most of your time spent on E/PO, and sample activities, as well as news on funding, policy, and what's happening in the E/PO community. The workspace also provides scientists and the public pathways to find opportunities for participation in E/PO, to learn about SMD E/PO projects and their impacts, to connect with SMD E/PO practitioners, and to explore resources to improve professional E/PO practice, including literature reviews, information about the Next Generation Science Standards, and best practices in evaluation and engaging diverse audiences. http://smdepo.org.

  7. Synthesis of g-C3N4/Ag3PO4 heterojunction with enhanced photocatalytic performance

    International Nuclear Information System (INIS)

    He, Peizhi; Song, Limin; Zhang, Shujuan; Wu, Xiaoqing; Wei, Qingwu

    2014-01-01

    Graphical abstract: g-C 3 N 4 /Ag 3 PO 4 heterojunction photocatalyst with visible-light response was prepared by a facile coprecipitation method. The results show that g-C 3 N 4 /Ag 3 PO 4 possesses a much higher activity for the decomposition of RhB than that of the pure Ag 3 PO 4 particles. The most mechanism is that g-C 3 N 4 /Ag 3 PO 4 heterojunction photocatalyst can efficiently separate the photogenerated electron–hole pairs, enhancing the photocatalytic activity of g-C 3 N 4 /Ag 3 PO 4 composites. - Highlights: • g-C 3 N 4 /Ag 3 PO 4 heterojunction showed much higher activity than that of Ag 3 PO 4 . • The high activity could be attributed to g-C 3 N 4 for modifying Ag 3 PO 4 . • More ·OH radicals may be significant reason to improve Ag 3 PO 4 activity. - Abstract: g-C 3 N 4 /Ag 3 PO 4 heterojunction photocatalyst with visible-light response was prepared by a facile coprecipitation method. The photocatalysts were characterized by X-ray powder diffraction, transmission electron microscopy, UV–vis absorption spectroscopy and Fourier transform infrared spectroscopy. The photocatalytic activities of the obtained samples were tested by using Rhodamine B (RhB) as the degradation target under visible light irradiation. g-C 3 N 4 /Ag 3 PO 4 decomposed RhB more effectively than the pure Ag 3 PO 4 particles did, and 2 wt.% g-C 3 N 4 had the highest activity. Furthermore, 2 wt.% g-C 3 N 4 /Ag 3 PO 4 degraded high-concentration RhB more potently than unmodified Ag 3 PO 4 did, probably because g-C 3 N 4 /Ag 3 PO 4 heterojunction photocatalyst enhanced the photocatalytic activity by efficiently separating the photogenerated electron–hole pairs

  8. Silica-modified luminescent LaPO4 :Eu@LaPO4 @SiO2 core/shell nanorods: Synthesis, structural and luminescent properties.

    Science.gov (United States)

    Ansari, Anees A

    2018-02-01

    Monoclinic-type tetragonal LaPO 4 :Eu (core) and LaPO 4 :Eu@LaPO 4 (core/shell) nanorods (NRs) were successfully prepared using a urea-based co-precipitation process under ambient conditions. An amorphous silica layer was coated around the luminescent core/shell NRs via the sol-gel process to improve their solubility and colloidal stability in aqueous and non-aqueous media. The prepared nano-products were systematically characterized by X-ray diffraction pattern, transmission electron microscopy, energy dispersive X-ray analysis, and FTIR, UV/Vis, and photoluminescence spectroscopy to examine their phase purity, crystal phase, surface chemistry, solubility and luminescence characteristics. The length and diameter of the nano-products were in the range 80-120 nm and 10-15 nm, respectively. High solubility of the silica-modified core/shell/Si NRs was found for the aqueous medium. The luminescent core NRs exhibited characteristic excitation and emission transitions in the visible region that were greatly affected by surface growth of insulating LaPO 4 and silica layers due to the multiphonon relaxation rate. Our luminescence spectral results clearly show a distinct difference in intensities for core, core/shell, and core/shell/Si NRs. Highly luminescent NRs with good solubility could be useful candidates for a variety of photonic-based biomedical applications. Copyright © 2017 John Wiley & Sons, Ltd.

  9. An evaluation of the exposure to 210Pb-210Po in italian population

    International Nuclear Information System (INIS)

    Clemente, G.F.; Santori, G.; Renzetti, A.

    1979-01-01

    Following an introduction on the behaviour in the environment and in man of 210 Pb- 210 Po, experimental data are reported on 210 Pb- 210 Po exposure of the italian population. The analytical methods used to measure 210 Pb- 210 Po activity in the many biological and environmental samples analyzed are also reported. The data collected refer to the intake, excretion, internal burden and metabolism both in a group of subjects representative of the general population and in other critical groups exposed to high internal contamination of 210 Pb- 210 Po, as the radioactive spa wopkes and the miners. The absorbed dose due to 210 Pb- 210 Po has also been evaluated, on the basis of data referring to the various population groups

  10. Ocena urodynamiczna nietrzymania moczu po radykalnej prostatektomii - studium przypadku

    Directory of Open Access Journals (Sweden)

    Rafał Święcicki

    2010-06-01

    Full Text Available Nietrzymanie moczu po radykalnej prostatektomii we wczesnym okresie po zabiegu występuje u około 30% operowanych, natomiast w okresie późnym, ponad rok po zabiegu, objawy wysiłkowego nietrzymania moczu utrzymują się u około 5% badanych chorych. Obiektywnych danych na temat przyczyn i nasilenia nietrzymania moczu może dostarczyć kompleksowe badanie urodynamiczne. Zasadnicze znaczenie dla rokowania zależne jest od stopnia dysfunkcji aparatu zwieraczowego. Cel pracy: Celem pracy była ocena możliwości diagnostycznych pooperacyjnego nietrzymania moczu u chorego po prostatektomii radykalnej, na podstawie diagnostyki urodynamicznej. Materia! i metody: W pracowni urodynamicznej 10. Wojskowego Szpitala Klinicznego z Polikliniką (WSKzP wykonano kompleksowe badanie urodynamiczne u chorego skarżącego się na nietrzymanie moczu 12 miesięcy po radykalnej prostatektomii. W ramach badania wykonano przepływ cewkowy, cystometrię, badanie ciśnieniowo-przepływowe oraz profiłometrię spoczynkową. Wyniki: Maksymalne ciśnienie zamknięcia cewki moczowej było wyraźnie obniżone, do wartości 8 cm H20, c o sugerowało obecność wysiłkowego nietrzymania moczu. Stwierdzono również objawy niestabilności wypieracza oraz cechy uszkodzenia mechanizmu zwieraczowego. Wynik ten miał duże znaczenie dla dalszych możliwości leczenia chorego. Wnioski: Kompleksowe badanie urodynamiczne ma istotne znaczenie w diagnozowaniu chorych z pooperacyjnym nietrzymaniu moczu.

  11. 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)

  12. Study of 210Po and 210Pb in the riverine environments of coastal Karnataka

    International Nuclear Information System (INIS)

    Narayana, Y.; Rajashekara, K.M.

    2010-01-01

    Activity of 210 Po and 210 Pb were measured in soil and sediment samples collected from the major rivers Kali, Sharavathi and Netravathi of Coastal Karnataka. The activity of these two radionuclides were determined by radiochemical separation of 210 Po and counting the activity using a ZnS(Ag) Alpha counter. The activity of 210 Pb was higher than that of 210 Po in the riverine environs. The 210 Po and 210 Pb content in sediment was found to increase with silt/clay and organic matter contents. However no significant correlation was found between the activity 210 Po and 210 Pb with pH in sediments. The activity of 210 Po and 210 Pb and influence of physico-chemical parameters on these radionuclides were studied and discussed in this paper.

  13. Structural and electrochemical studies of PPy/PEG-LiFePO4 cathode material for Li-ion batteries

    International Nuclear Information System (INIS)

    Fedorkova, Andrea; Nacher-Alejos, Ana; Gomez-Romero, Pedro; Orinakova, Renata; Kaniansky, Dusan

    2010-01-01

    A simple chemical oxidative polymerization of pyrrole (Py) directly onto the surface of LiFePO 4 particles was applied to the synthesis of polypyrrole-LiFePO 4 (PPy-LiFePO 4 ) powder. The LiFePO 4 sample without carbon coating was synthesized by a solvothermal method. The polyethylene glycol (PEG) was used as additive during Py polymerization for increasing the PPy-LiFePO 4 conductivity. Properties of resulting LiFePO 4 , PPy-LiFePO 4 and PPy/PEG-LiFePO 4 samples were characterized by XRD, SEM, TGA and galvanostatic charge-discharge measurements. These methods confirmed the presence of polypyrrole on LiFePO 4 particles and its homogeneous distribution in the resulting powder material. The PPy/PEG-LiFePO 4 composites show higher discharge capacity than pure LiFePO 4 , as PPy/PEG network improves the electron conductivity. It presents specific discharge capacity of 153 mAh/g at C/5 rate.

  14. 210Pb and 210Po in Finnish cereals.

    Science.gov (United States)

    Turtiainen, Tuukka; Kostiainen, Eila; Hallikainen, Anja

    2011-05-01

    A survey was carried out on the activity concentrations of (210)Pb and (210)Po in cereal grains produced in Finland. The cereal species were wheat (Triticum aestivum), rye (Secale cereale), oats (Avena sativa) and barley (Hordeum vulgare), which account for 90% of the Finnish consumption of cereal products. The survey consisted of 18 flour and 13 unprocessed cereal samples and one hulled grain sample from 22 flour mills. According to the results, the mean (210)Pb/(210)Po concentrations in wheat grains, wheat flour, rye flour, oat grains and barley grains were 0.29, 0.12, 0.29, 0.36 and 0.36 Bq kg(-1), respectively. Combined with the consumption rates of the products, we assess that the mean effective doses from (210)Pb and (210)Po in cereal products for the adult male and female population are 22 and 17 μSv per year, respectively. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Synthesis, crystal structure and spectroscopy properties of Na 3AZr(PO 4) 3 ( A=Mg, Ni) and Li 2.6Na 0.4NiZr(PO 4) 3 phosphates

    Science.gov (United States)

    Chakir, M.; El Jazouli, A.; de Waal, D.

    2006-06-01

    Na 3AZr(PO 4) 3 ( A=Mg, Ni) phosphates were prepared at 750 °C by coprecipitation route. Their crystal structures have been refined at room temperature from X-ray powder diffraction data using Rietveld method. Li 2.6Na 0.4NiZr(PO 4) 3 was synthesized through ion exchange from the sodium analog. These materials belong to the Nasicon-type structure. Raman spectra of Na 3AZr(PO 4) 3 ( A=Mg, Ni) phosphates present broad peaks in favor of the statistical distribution in the sites around PO 4 tetrahedra. Diffuse reflectance spectra indicate the presence of octahedrally coordinated Ni 2+ ions.

  16. On a framework for generating PoD curves assisted by numerical simulations

    Energy Technology Data Exchange (ETDEWEB)

    Subair, S. Mohamed, E-mail: prajagopal@iitm.ac.in; Agrawal, Shweta, E-mail: prajagopal@iitm.ac.in; Balasubramaniam, Krishnan, E-mail: prajagopal@iitm.ac.in; Rajagopal, Prabhu, E-mail: prajagopal@iitm.ac.in [Indian Institute of Technology Madras, Department of Mechanical Engineering, Chennai, T.N. (India); Kumar, Anish; Rao, Purnachandra B.; Tamanna, Jayakumar [Indira Gandhi Centre for Atomic Research, Metallurgy and Materials Group, Kalpakkam, T.N. (India)

    2015-03-31

    The Probability of Detection (PoD) curve method has emerged as an important tool for the assessment of the performance of NDE techniques, a topic of particular interest to the nuclear industry where inspection qualification is very important. The conventional experimental means of generating PoD curves though, can be expensive, requiring large data sets (covering defects and test conditions), and equipment and operator time. Several methods of achieving faster estimates for PoD curves using physics-based modelling have been developed to address this problem. Numerical modelling techniques are also attractive, especially given the ever-increasing computational power available to scientists today. Here we develop procedures for obtaining PoD curves, assisted by numerical simulation and based on Bayesian statistics. Numerical simulations are performed using Finite Element analysis for factors that are assumed to be independent, random and normally distributed. PoD curves so generated are compared with experiments on austenitic stainless steel (SS) plates with artificially created notches. We examine issues affecting the PoD curve generation process including codes, standards, distribution of defect parameters and the choice of the noise threshold. We also study the assumption of normal distribution for signal response parameters and consider strategies for dealing with data that may be more complex or sparse to justify this. These topics are addressed and illustrated through the example case of generation of PoD curves for pulse-echo ultrasonic inspection of vertical surface-breaking cracks in SS plates.

  17. Poésie et philosophie dans Faust I de Goethe

    OpenAIRE

    Abraham, Bénédicte

    2013-01-01

    L’interrogation qui porte sur l’alliance ou la mésalliance entre la philosophie et la poésie n’est pas nouvelle. Elle remonte à l’Antiquité, mais la fascination réciproque de ces deux champs du langage et de la pensée n’en est pas moins restée vive pour autant. Dans sa Poétique, Aristote consacre plusieurs pages à la personne du poète dont il considère l’activité comme étant plus noble et plus philosophique que celle de l’historien. Ce qui constitue, aux yeux d’Aristote, la supériorité de la ...

  18. Correlation of regional disease and in vivo PO2 in rat mammary adenocarcinoma.

    Science.gov (United States)

    Cole, M A; Crawford, D W; Warner, N E; Puffer, H W

    1983-07-01

    A knowledge of the distribution of oxygen tension (PO2) and vascularization in neoplasia has been fundamental to understanding relationships between tumor growth, hypoxia, and therapy. We have combined recessed oxygen microcathode and freeze-substitution techniques to correlate in situ PO2 profiles and morphologic features in 7,12-dimethylbenz(a)anthracene (DMBA) tumors in rats. Overlying connective tissue of transplanted tumor was exposed by a 1-2 mm incision and a cross-stitch pattern demarcated electrode puncture sites for histologic reference. Three buffered salt solutions (BSS) with different PO2 were each allowed to flow through a well over the tumor where electrodes were placed for calibration. Zero electrode oxygen current was recorded from a buffered yeast-agar mixture of zero torr. PO2 was recorded at 5-mu intervals to approximately 1-2 mm. Atmospheric contamination was eliminated by continuous well flow of BSS, 30 torr. Finally, the tumor and surrounding tissues were quick-frozen in vivo with Freon 22 and liquid nitrogen. The tissue block was freeze-substituted and sectioned. PO2 profiles were superimposed onto correspondingly scaled photomicrographs. A viable periphery with a PO2 range of 50-82 torr and a transition to necrotic areas of PO2, 2-13 torr were observed. This transition was characterized by PO2 gradients within distances of 50-300 mu at variable puncture depths. This technique should be useful in further studies of growth, necrosis, and therapy.

  19. Development of a Portable Motor Learning Laboratory (PoMLab).

    Science.gov (United States)

    Takiyama, Ken; Shinya, Masahiro

    2016-01-01

    Most motor learning experiments have been conducted in a laboratory setting. In this type of setting, a huge and expensive manipulandum is frequently used, requiring a large budget and wide open space. Subjects also need to travel to the laboratory, which is a burden for them. This burden is particularly severe for patients with neurological disorders. Here, we describe the development of a novel application based on Unity3D and smart devices, e.g., smartphones or tablet devices, that can be used to conduct motor learning experiments at any time and in any place, without requiring a large budget and wide open space and without the burden of travel on subjects. We refer to our application as POrtable Motor learning LABoratory, or PoMLab. PoMLab is a multiplatform application that is available and sharable for free. We investigated whether PoMLab could be an alternative to the laboratory setting using a visuomotor rotation paradigm that causes sensory prediction error, enabling the investigation of how subjects minimize the error. In the first experiment, subjects could adapt to a constant visuomotor rotation that was abruptly applied at a specific trial. The learning curve for the first experiment could be modeled well using a state space model, a mathematical model that describes the motor leaning process. In the second experiment, subjects could adapt to a visuomotor rotation that gradually increased each trial. The subjects adapted to the gradually increasing visuomotor rotation without being aware of the visuomotor rotation. These experimental results have been reported for conventional experiments conducted in a laboratory setting, and our PoMLab application could reproduce these results. PoMLab can thus be considered an alternative to the laboratory setting. We also conducted follow-up experiments in university physical education classes. A state space model that was fit to the data obtained in the laboratory experiments could predict the learning curves

  20. Development of a Portable Motor Learning Laboratory (PoMLab.

    Directory of Open Access Journals (Sweden)

    Ken Takiyama

    Full Text Available Most motor learning experiments have been conducted in a laboratory setting. In this type of setting, a huge and expensive manipulandum is frequently used, requiring a large budget and wide open space. Subjects also need to travel to the laboratory, which is a burden for them. This burden is particularly severe for patients with neurological disorders. Here, we describe the development of a novel application based on Unity3D and smart devices, e.g., smartphones or tablet devices, that can be used to conduct motor learning experiments at any time and in any place, without requiring a large budget and wide open space and without the burden of travel on subjects. We refer to our application as POrtable Motor learning LABoratory, or PoMLab. PoMLab is a multiplatform application that is available and sharable for free. We investigated whether PoMLab could be an alternative to the laboratory setting using a visuomotor rotation paradigm that causes sensory prediction error, enabling the investigation of how subjects minimize the error. In the first experiment, subjects could adapt to a constant visuomotor rotation that was abruptly applied at a specific trial. The learning curve for the first experiment could be modeled well using a state space model, a mathematical model that describes the motor leaning process. In the second experiment, subjects could adapt to a visuomotor rotation that gradually increased each trial. The subjects adapted to the gradually increasing visuomotor rotation without being aware of the visuomotor rotation. These experimental results have been reported for conventional experiments conducted in a laboratory setting, and our PoMLab application could reproduce these results. PoMLab can thus be considered an alternative to the laboratory setting. We also conducted follow-up experiments in university physical education classes. A state space model that was fit to the data obtained in the laboratory experiments could predict the

  1. Notas sobre poética em andamento

    Directory of Open Access Journals (Sweden)

    Mauro Faccioni Filho

    2006-06-01

    Full Text Available 1.1. A aflição poética não desapareceu nem abandonou o cenário da produção, mas é evidente que esse mesmo cenário está invadido por demonstrações artificiais. Tais demonstrações podem ser respostas inconscientes às expectativas de uma historiografia da literatura. Ou respostas a uma estratégia de contextualização da produção organizada pela própria crítica que a sustenta. 1.2. As notas que seguem são reflexões para discutir disparidades e distorções em três diferentes tipos de poética que, para muitos, apontam como sendo caminhos de referência para uma certa continuidade da poesia, hoje, no Brasil. Pode-se representar tais poéticas em três linhas bastante distintas, três tendências gerais. São linhas que podem ser definidas como vetores defasados agindo como forças centrífugas, que serão denominadas aqui de pré-modernismo-contemporâneo, modernismo e pós-modernismo.

  2. Kinetic Monte Carlo Study of Li Intercalation in LiFePO4.

    Science.gov (United States)

    Xiao, Penghao; Henkelman, Graeme

    2018-01-23

    Even as a commercial cathode material, LiFePO 4 remains of tremendous research interest for understanding Li intercalation dynamics. The partially lithiated material spontaneously separates into Li-poor and Li-rich phases at equilibrium. Phase segregation is a surprising property of LiFePO 4 given its high measured rate capability. Previous theoretical studies, aiming to describe Li intercalation in LiFePO 4 , include both atomic-scale density functional theory (DFT) calculations of static Li distributions and entire-particle-scale phase field models, based upon empirical parameters, studying the dynamics of the phase separation. Little effort has been made to bridge the gap between these two scales. In this work, DFT calculations are used to fit a cluster expansion for the basis of kinetic Monte Carlo calculations, which enables long time scale simulations with accurate atomic interactions. This atomistic model shows how the phases evolve in Li x FePO 4 without parameters from experiments. Our simulations reveal that an ordered Li 0.5 FePO4 phase with alternating Li-rich and Li-poor planes along the ac direction forms between the LiFePO 4 and FePO 4 phases, which is consistent with recent X-ray diffraction experiments showing peaks associated with an intermediate-Li phase. The calculations also help to explain a recent puzzling experiment showing that LiFePO 4 particles with high aspect ratios that are narrower along the [100] direction, perpendicular to the [010] Li diffusion channels, actually have better rate capabilities. Our calculations show that lateral surfaces parallel to the Li diffusion channels, as well as other preexisting sites that bind Li weakly, are important for phase nucleation and rapid cycling performance.

  3. Po Superconducting Magnet:detail of the windings

    CERN Multimedia

    1982-01-01

    The Po superconducting dipole was built as a prototype beam transport magnet for the SPS extracted proton beam Po. Its main features were: coil aperture 72 mm, length 5 m, room-temperature yoke, NbTi cable conductor impregnated with solder, nominal field 4.2 T at 4.7 K (87% of critical field). It reached its nominal field without any quench. The photo shows a detail of the inner layer winding before superposing the outer layer to form the complete coil of a pole. Worth noticing is the interleaved glass-epoxy sheet (white) with grooved channels for the flow of cooling helium. See also 8307552X.

  4. Determination of 210Pb and 210Po in Brazilian cigarette tobacco

    International Nuclear Information System (INIS)

    Peres, A.C.; Hiromoto, G.

    2000-01-01

    Cigarette smoking is one of the important pathways that could contribute to enhance the radiation dose to man, due to the relatively large concentrations of 210 Pb and 210 Po found in tobacco leaves. In this work, concentrations of these two radionuclides were determined in eight of the most commercialized cigarette brands produced in Brazil. The samples analyzed were bought randomly in the market. The 210 Pb was determined by counting the beta activity of the 210 Bi in a gas flow proportional detector, after radiochemical separation and precipitation of the PbCrO 4 . The 210 Po was determined by alpha spectrometry, using a surface barrier detector, after radiochemical separation and spontaneous deposition of Po in copper disk. The results showed concentrations ranging from 15,8 to 30,2 mBq per gram of dry tobacco for 210 Pb and from 18,8 to 27,4 mBq per gram of dry tobacco for 210 Po. Taking in account the experimental error of the measurements, radioactive equilibrium between 210 Pb and 210 Po is observed for all analyzed samples. This result was expected, since the delayed time from the harvest of tobacco leaves to the introduction of cigarettes in the market is enough to reach that equilibrium. Assuming a 20 cigarettes per day consumption, and a 10% of Pb and 20% of Po being inhaled by the primary smokers, it is obtained a value of yearly intake of 11,3 Bq of 210 Pb and 21,2 Bq of 210 Po, due to cigarette consumption. These values lead to an increment to the committed effective dose of 0,025 mSv year -1 and an increment to the probability of getting cancer of 1 x 10 -6 per year. (author)

  5. Natural occurring radionuclide 210Po in the components of the Black Sea ecosystem

    International Nuclear Information System (INIS)

    Lazorenko, G. G.; Polikarpov, G. G.

    2006-01-01

    The interest to study of the behavior of naturally occurring radionuclide 2 10Po in marine ecosystem was caused by its main contribution to the doses of irradiation to hydrobionts. This work presents own data of 2 10Po concentrations determined in water, bottom sediments and hydrobionts of the Black Sea in 1998-2004. 2 10Po concentrations in water varied from 0.58 to 1.02 Bqxm - 3. Their range in bottom sediments from shelf zone and open part of the Black Sea was 11.5-496.5 Bqxkg - 1 dry weight with maximum in the North-West region. The range of 2 10Po concentrations in bottom sediments from the Eastern part of the Black Sea was 4.5-220 Bqxkg-1 dry weight. Concentration factors (CF) of 2 10Po in bottom sediments reached 10 4 -10 5 . 2 10Po concentrations in the Black Sea hydrobionts are reported and compared with published data in the same taxa. The range of 2 10Po concentrations in the Black Sea mesozooplankton was 1.7-3.5 Bqxkg - 1 wet weight. It was 1.9-2.9 Bqxkg - 1 wet weight in the representative species of macro plankton community, namely the ctenophore Beroe ovata. 2 10Po concentrations in the Black Sea fishes depend on their belonging to different ecological groups and decrease from pelagic species to demersal and bottom ones. 2 10Po concentrations in the Black Sea mollusks excluding small species Nana nerithea were on the highest levels determined in hydrobionts inhabiting in this region. Concentration factors of this radionuclide, estimated on a wet weight basis, reached values of 1.5x10 3 for macrophytes, 4x10 3 for total zooplankton, 10 3 -10 4 for the entire fishes, depending on their ecological groups affiliation and (3.0-6.7) x10 4 for mollusks. So, the ability of the Black Sea hydrobionts to accumulate natural radionuclide 2 10Po is comparable with that of similar species from others marine and oceanic areas

  6. One-pot synthesis and electrochemical reactivity of carbon coated LiFePO4 spindles

    International Nuclear Information System (INIS)

    Yu Juanjuan; Hu Juncheng; Li Jinlin

    2012-01-01

    Highlights: ► Carbon coated LiFePO 4 spindles have been successfully synthesized via a novel supercritical method. ► The concentrations of lithium have an effect on the morphology of carbon coated LiFePO 4 . ► Amorphous carbon layer formed on the surface of LiFePO 4 by adding glucose. ► The carbon coating is responsible for the enhanced electrochemical performance. - Abstract: Spindle-like carbon coated LiFePO 4 (LiFePO 4 /C) composites have been successfully synthesized via a novel one-pot supercritical methanol method. The products were characterized by X-ray power diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). The particle size, morphology and electrochemical reactivity changed with the concentration of lithium and carbon source. A possible morphology evolution process was also proposed. The glucose not only facilitates the formation of single crystalline LiFePO 4 , but also gives an amorphous carbon layer on the surface LiFePO 4 spindles.

  7. pO2 and regional blood flow in a rabbit model of limb ischemia.

    Science.gov (United States)

    Grinberg, Oleg Y; Hou, Huagang; Grinberg, Stalina A; Moodie, Karen L; Demidenko, Eugene; Friedman, Bruce J; Post, Mark J; Swartz, Harold M

    2004-06-01

    Oxygen tension (pO2) in muscles and regional blood flow were measured in a rabbit model of limb ischemia. pO2 was measured repetitively by EPR oximetry with EMS char in four different muscle groups in the same animals. Blood flow in the same muscles at several time points was measured using microspheres. A linear mixed effects model was developed to analyze the data on pO2 and blood flow. The results suggest that while under normal conditions pO2 in muscles does not depend significantly on blood flow, immediately after arterial occlusion pO2 correlates linearly with blood flow. Within two weeks of occlusion the pO2 is recovered to 45% of baseline. This study demonstrates, for the first time, the applicability of EPR oximetry in animals larger than rodents.

  8. Bulk Superconductivity and Disorder in Single Crystals of LaFePO

    Energy Technology Data Exchange (ETDEWEB)

    Analytis, James G.; Chu, Jiun-Haw; Erickson, Ann S.; Kucharczyk, Chris; /Stanford U., Appl. Phys. Dept.; Serafin, Alessandro; Carrington, Antony; /Bristol U.; Cox, Catherine; Kauzlarich, Susan M.; Hope, Hakon; /UC, Davis. Dept. Chem.

    2010-02-15

    We have studied the intrinsic normal and superconducting properties of the oxypnictide LaFePO. These samples exhibit bulk superconductivity and the evidence suggests that stoichiometric LaFePO is indeed superconducting, in contrast to other reports. We find that superconductivity is independent of the interplane residual resistivity {rho}{sub 0} and discuss the implications of this on the nature of the superconducting order parameter. Finally we find that, unlike T{sub c}, other properties in single-crystal LaFePO including the resistivity and magnetoresistance, can be very sensitive to disorder.

  9. Morphology and conductivity study of solid electrolyte Li{sub 3}PO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Prayogi, Lugas Dwi, E-mail: ldprayodi@gmail.com; Faisal, Muhamad [Engineering Physics, Sepuluh Nopember Institute of Technology ITS Campus, Sukolilo, Surabaya 6011 (Indonesia); Kartini, Evvy, E-mail: kartini@batan.go.id; Honggowiranto, Wagiyo; Supardi [Center for Science and Technology of Advanced Materials, National Nuclear Energy Agency Kawasan Puspiptek Serpong, Tangerang Selatan15314, Banten (Indonesia)

    2016-02-08

    The comparison between two different methods of synthesize of solid electrolyte Li{sub 3}PO{sub 4} as precursor material for developing lithium ion battery, has been performed. The first method is to synthesize Li{sub 3}PO{sub 4} prepared by wet chemical reaction from LiOH and H{sub 3}PO{sub 4} which provide facile, abundant available resource, low cost, and low toxicity. The second method is solid state reaction prepared by Li{sub 2}CO{sub 3} and NH{sub 4}H{sub 2}PO{sub 4.} In addition, the possible morphology identification of comparison between two different methods will also be discussed. The composition, morphology, and additional identification phase and another compound of Li{sub 3}PO{sub 4} powder products from two different reaction are characterized by SEM, EDS, and EIS. The Li{sub 3}PO{sub 4} powder produced from wet reaction and solid state reaction have an average diameter of 0.834 – 7.81 µm and 2.15 – 17.3 µm, respectively. The density of Li{sub 3}PO{sub 4} prepared by wet chemical reaction is 2.238 gr/cm{sup 3}, little bit lower than the sample prepared by solid state reaction which density is 2.3560 gr/cm{sup 3}. The EIS measurement result shows that the conductivity of Li{sub 3}PO{sub 4} is 1.7 x 10{sup −9} S.cm{sup −1} for wet chemical reaction and 1.8 x 10{sup −10} S.cm{sup −1} for solid state reaction. The conductivity of Li{sub 3}PO{sub 4} is not quite different between those two samples even though they were prepared by different method of synthesize.

  10. Postępowanie z chorym po zawale serca

    Directory of Open Access Journals (Sweden)

    Kalina Niedolaz

    2011-10-01

    Full Text Available Choroba wieńcowa, czyli choroba niedokrwienna serca na podłożu miażdżycy tętnic wieńcowych, stanowi niezwykle istotny problem kliniczny. Jej bezpośrednim i często nieuchronnym następstwem jest zawał mięśnia serca. Zawał najczęściej jest spowodowany zamknięciem tętnicy wieńcowej w wyniku uszkodzenia blaszki miażdżycowej (jej pęknięcia lub erozji z następowym wytworzeniem dystalnego zakrzepu i powoduje zniszczenie prawidłowo działającego mięśnia sercowego. Chory po przebytym zawale mię- śnia serca należy do grupy pacjentów obciążonych wysokim ryzykiem sercowo-naczyniowym, a więc zagrożony jest wystąpieniem kolejnych incydentów, takich jak zawał, udar mózgu i zgon. Prawidłowe postępowanie po przebytym zawale pozwala na istotną redukcję ryzyka i korzystnie wpływa na rokowanie. Prewencja wtórna po zawale serca obejmuje postępowanie niefarmakologiczne, czyli modyfikację stylu życia, i leczenie farmakologiczne. Największe znaczenie ma wyeliminowanie czynników ryzyka, tj. zaprzestanie palenia papierosów, prawidłowa kontrola ciśnienia tętniczego i normalizacja poziomu cholesterolu, a także redukcja nadwagi i systematyczna aktywność fizyczna. Świadomość pacjentów i zaangażowanie lekarzy są decydujące dla osiągnięcia korzystnych efektów prewencji wtórnej po zawale serca. Artykuł przedstawia zasady, którym powinien podlegać każdy chory po zawale mięśnia serca, uwzględnia zalecenia dotyczące postępowania niefarmakologicznego, wytyczne dotyczące odpowiedniej farmakoterapii według aktualnych standardów. W pracy uwzględniono również zasady postępowania z chorym po zawale w sytuacjach szczególnych, jakimi są choroby współistniejące, takie jak nadciśnienie tętnicze, cukrzyca, dysfunkcja lewej komory i niewydolność serca, przewlekła choroba nerek, przewlekła obturacyjna choroba płuc.

  11. BaO-Nd2O3-CuOx subsolidus equilibria under carbonate-free conditions at pO2=100 Pa and at pO2=21 kPa

    International Nuclear Information System (INIS)

    Wong-Ng, W.; Cook, L.P.; Suh, J.; Coutts, R.; Stalick, J.K.; Levin, I.; Huang, Q.

    2003-01-01

    Subsolidus phase equilibria of the BaO-Nd 2 O 3 -CuO x system at pO 2 =100 Pa (0.1% O 2 volume fraction, 810 deg. C) and at pO 2 =21 kPa (21% O 2 volume fraction, 930 deg. C) have been investigated by applying controlled-atmosphere methods to minimize the presence of carbonate and CO 2 and H 2 O contamination. Under carbonate-free conditions, the BaO-Nd 2 O 3 -CuO x phase diagrams at pO 2 =100 Pa and at pO 2 =21 kPa are similar to one another except for differences in the extent of the solid solutions. Apart from the limiting binary phases, the ternary system consists of three solid solutions and one stoichiometric ternary compound. The first solid solution is the high T c series, Ba 2-x Nd 1+x Cu 3 O 6+z (0.3≥x≥0 at pO 2 =100 Pa; 0.95≥x≥ 0 at pO 2 =21 kPa). At pO 2 =21 kPa, a compositionally dependent phase change was detected, from tetragonal (0.7>x≥0) to orthorhombic (0.95≥x≥0.7). The second solid solution series, the 'brown-phase' Ba 1+x Nd 2-x CuO z , has a narrow homogeneity region (0.10>x≥0 at pO 2 =100 Pa; 0.15>x≥0 at pO 2 =21 kPa). In the high BaO part of the phase diagram, a third solid solution (Ba 2-x Nd x )CuO 3+z (x=0 to ∼ 0.3 at pO 2 =100 Pa; x=0-0.45 at pO 2 =21 kPa) was confirmed, as well as a nominally stoichiometric phase, Ba 4 Nd 2 Cu 2 O z . The latter phase is an insulator, with a structure comprised of unusual CuO 5 linear chains. A significant difference in tie line distribution involving the Ba 2-x Nd 1+x Cu 3 O 6+z superconductor was found under carbonate-free conditions relative to literature studies completed in air. Instead of the BaCuO 2+x -Ba 2+x Nd 4-x Cu 2 O z tie line normally encountered in air, a Ba 2-x Nd 1+x Cu 3 O 6+z -(Ba,Nd) 2 CuO 3+x tie line was established. This tie line substantially expands the field of stability of the Ba 2-x Nd 1+x Cu 3 O 6+z superconductor phase into the BaO-rich region of the phase diagram. Implications for the processing of materials based on the Ba 2-x Nd 1+x Cu 3 O 6+z

  12. High-pressure structural, elastic, and thermodynamic properties of zircon-type HoPO4 and TmPO4

    International Nuclear Information System (INIS)

    Gomis, O; Lavina, B; Rodríguez-Hernández, P; Muñoz, A; Errandonea, R; Errandonea, D; Bettinelli, M

    2017-01-01

    Zircon-type holmium phosphate (HoPO 4 ) and thulium phosphate (TmPO 4 ) have been studied by single-crystal x-ray diffraction and ab initio calculations. We report on the influence of pressure on the crystal structure, and on the elastic and thermodynamic properties. The equation of state for both compounds is accurately determined. We have also obtained information on the polyhedral compressibility which is used to explain the anisotropic axial compressibility and the bulk compressibility. Both compounds are ductile and more resistive to volume compression than to shear deformation at all pressures. Furthermore, the elastic anisotropy is enhanced upon compression. Finally, the calculations indicate that the possible causes that make the zircon structure unstable are mechanical instabilities and the softening of a silent B 1u mode. (paper)

  13. Pb-210 and Po-210 from active volcanoes in Japan

    International Nuclear Information System (INIS)

    Komura, K.; Uchida, K.; Yamamoto, M.; Ueno, K.

    1991-01-01

    The concentration of Pb-210 and Po-210 in the surface air of volcanic areas is of considerable interest from the viewpoints of geochemistry, geophysics and also health physics, because these nuclides are the useful tracers for the estimation of the residence time or life time of aerosols, and give the significant radiation dose due to inhalation and ingestion through food stuffs. Since the establishment of Low Level Radioactivity Laboratory, Kanazawa University, in 1976, the measurement of environmental radioactivity has been one of the main subjects, and the measurement of Pb-210 and Po-210 in the surface air of Kagoshima was begun in 1987 to estimate the contribution from Volcano Sakurajima. In this study, the measurement of Pb-210 and Po-210 in air borne particles collected with air samplers, volcanic ash and lava of volcano Sakurajima of which the age of eruption is known. Moreover, the Po-210 in the volcanic gas and sulfur sublimate in the samples collected in four active volcanoes in Hokkaido was measured. The experiment and the results are reported. (K.I.)

  14. Pb-210 and Po-210 from active volcanoes in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Komura, K; Uchida, K; Yamamoto, M; Ueno, K [Kanazawa Univ. (Japan)

    1991-01-01

    The concentration of Pb-210 and Po-210 in the surface air of volcanic areas is of considerable interest from the viewpoints of geochemistry, geophysics and also health physics, because these nuclides are the useful tracers for the estimation of the residence time or life time of aerosols, and give the significant radiation dose due to inhalation and ingestion through food stuffs. Since the establishment of Low Level Radioactivity Laboratory, Kanazawa University, in 1976, the measurement of environmental radioactivity has been one of the main subjects, and the measurement of Pb-210 and Po-210 in the surface air of Kagoshima was begun in 1987 to estimate the contribution from Volcano Sakurajima. In this study, the measurement of Pb-210 and Po-210 in air borne particles collected with air samplers, volcanic ash and lava of volcano Sakurajima of which the age of eruption is known. Moreover, the Po-210 in the volcanic gas and sulfur sublimate in the samples collected in four active volcanoes in Hokkaido was measured. The experiment and the results are reported. (K.I.).

  15. Formation of condensed phosphates when heating CdO with NH4H2PO4

    International Nuclear Information System (INIS)

    Atstinya, L.Zh.; Dindune, A.P.; Konstant, Z.A.

    1987-01-01

    A study was made on process of CdO thermal condensation with NH 4 H 2 PO 4 depending on the ratio of basic substances and temperature synthesis conditions. It was established that reaction between CdO and NH 4 H 2 PO 4 of pure for analysis grade was initiated when basic mixtures were pounded with a pestle. Heating of cadmium-ammonium triphosphate with products of ammonium dihydrophosphate polycondensation in 330-350 deg C range resulted to CdNH 4 (PO 3 ) 3 formation. Exoeffect on DTA curves corresponded at 540 deg C to formation of α-Cd(PO 3 ) 2 . α-Cd(PO 3 ) 2 → β-Cd(PO 3 ) 2 transition took place at 810 deg C with successive melting of β-Cd(PO 3 ) 2 at 850 deg C, which was supported by the DTA curve and sharp change of the relative electric conductivity

  16. Increased intraretinal PO2 in short-term diabetic rats.

    Science.gov (United States)

    Lau, Jennifer C M; Linsenmeier, Robert A

    2014-12-01

    In diabetic retinopathy, neovascularization is hypothesized to develop due to hypoxia in the retina. However, evidence for retinal hypoxia is limited, and the progressive changes in oxygenation are unknown. The objective of this study was to determine if retinal hypoxia occurs early in the development of diabetes. Intraretinal oxygen (PO2) profiles were recorded with oxygen-sensitive microelectrodes in control and diabetic Long-Evans rats at 4 and 12 weeks after induction of diabetes. Diabetes did not affect oxygen consumption in the photoreceptors in either dark or light adaptation. Oxygenation of the inner retina was not affected after 4 weeks of diabetes, although vascular endothelial growth factor levels increased. At 12 weeks, average inner retinal PO2, normalized to choriocapillaris PO2, was higher in diabetic rats than in age-matched controls, which was opposite to what was expected. Thus retinal hypoxia is not a condition of early diabetes in rat retina. Increased inner retinal PO2 may occur because oxygen consumption decreases in the inner retina. © 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  17. Determination of {sup 210}Pb and {sup 210}Po in cigarette tobacco; Determinacao de {sup 210}Pb e {sup 210}Po em tabaco de cigarros nacionais

    Energy Technology Data Exchange (ETDEWEB)

    Peres, Ana Claudia

    1999-07-01

    Cigarette smoking is one of the important pathways that could contribute to enhance the radiation dose to man, due to the relatively large concentrations of {sup 210}Pb and {sup 210}Po found in tobacco leaves. In this work, concentrations of these two radionuclides were determined in eight of the most commercialized cigarette brands produced in Brazil. The samples analyzed were bought randomly in the market. The {sup 210}Pb was determined by counting the beta activity of the {sup 210}Bi in a gas flow proportional detector, after radiochemical separation and precipitation of the PbCr0{sub 4}. The {sup 210}Po was determined by alpha spectrometry, using a surface barrier detector, after radiochemical separation and spontaneous deposition of Po in copper disk. The results showed concentrations ranging from 11,9 to 30,2 mBq per gram of dry tobacco for {sup 210}Pb and from 10,9 to 27,4 mBq per gram of dry tobacco for {sup 210}Po. (author)

  18. Build up of radon, /sup 218/Po and /sup 214/Po in a Karlsruhe diffusion chamber as a function of time

    International Nuclear Information System (INIS)

    Fazal-ur-Rehman; Jamil, K.; Ali, S.; Khan, H.A.

    1996-01-01

    Passive radon /sup 222/Rn dosimeters employing particle detectors are widely used in concentration (p Ci/l) measurement in houses, mines and other areas of activity. These dosimeters yield track density which is needed to be converted into physically meaningful parameter of radon concentration in either p Ci/l or Bq m/sup -3/. Therefore, it is required to know the separate contributions of /sup 222/Rn and its progeny. In the present study we have measured the concentration of /sup 222/Rn and its daughters (/sup 218/Po and /sup 214/Po) separately in the Karlsruhe diffusion chamber radon dosimeter, with and without a filter, as a function of time by an active method using a surface barrier detector. The build up behavior of radon and its two daughters (/sup 218/Po and /sup 214/Po) as a function of time was studied by plotting the area under each peak versus collection time. The differential curves and the relative concentration of radon daughters as a function of time were also studied. The concentration of radon and its daughters shows a somewhat linear build up as a function of time for the presently studied time periods. The results of this experiment are expected to be useful in converting the integrated alpha track density as measured by a particle track detector, (used in passive radon dosimetry) to radon concentration levels and for determination of equilibrium factor. (author)

  19. The role of 210Po and 210Pb in low radioactivity experiments and ultrapure water

    International Nuclear Information System (INIS)

    Giammarch, Marco G.

    2013-01-01

    210 Po and 210 Pb isotopes constitute a major background for low background nuclear physics experiments searching for rare events. Searches for solar neutrinos, double beta decay, dark matter and other rare phenomena need to control and monitor radioactivity from Po and Pb through measurements and purification processes. Ultrapure water is often used in these experiments; therefore the issue of minimizing Po and Pb content in water will also be discussed. Finally, the role of 214 Po and 212 Po in low background experiments will be briefly recalled. (author)

  20. Prediction of Wind Energy Resources (PoWER) Users Guide

    Science.gov (United States)

    2016-01-01

    ARL-TR-7573● JAN 2016 US Army Research Laboratory Prediction of Wind Energy Resources (PoWER) User’s Guide by David P Sauter...manufacturer’s or trade names does not constitute an official endorsement or approval of the use thereof. Destroy this report when it is no longer needed. Do...not return it to the originator. ARL-TR-7573 ● JAN 2016 US Army Research Laboratory Prediction of Wind Energy Resources (PoWER

  1. Water quality in Italy: Po River and its tributaries

    International Nuclear Information System (INIS)

    Crosa, G.; Marchetti, R.

    1993-01-01

    For Italy's Po River hydrological basin, artificial reservoirs have a great importance; water reserve is about 1600 million cubic meters for the hydroelectric reservoirs and about 76 million cubic meters for irrigation. The principal factors determining the water quality of the Po River and its tributaries are examined. Organic micropollutants, metals and the microbial load are the principal parameters altering the quality of the waters; dilution is the prevailing factor reducing this contamination

  2. Role of nitric oxide of the median preoptic nucleus (MnPO in the alterations of salivary flow, arterial pressure and heart rate induced by injection of pilocarpine into the MnPO and intraperitoneally

    Directory of Open Access Journals (Sweden)

    Wilson A. Saad

    2003-07-01

    Full Text Available We investigated the effect of L-NAME, a nitric oxide (NO inhibitor and sodium nitroprusside (SNP, an NO-donating agent, on pilocarpine-induced alterations in salivary flow, mean arterial blood pressure (MAP and heart rate (HR in rats. Male Holtzman rats (250-300 g were implanted with a stainless steel cannula directly into the median preoptic nucleus (MnPO. Pilocarpine (10, 20, 40, 80, 160 µg injected into the MnPO induced an increase in salivary secretion (P<0.01. Pilocarpine (1, 2, 4, 8, 16 mg/kg ip also increased salivary secretion (P<0.01. Injection of L-NAME (40 µg into the MnPO prior to pilocarpine (10, 20, 40, 80, 160 µg injected into the MnPO or ip (1, 2, 4, 8, 16 mg/kg increased salivary secretion (P<0.01. SNP (30 µg injected into the MnPO or ip prior to pilocarpine attenuated salivary secretion (P<0.01. Pilocarpine (40 µg injection into the MnPO increased MAP and decreased HR (P<0.01. Pilocarpine (4 mg/kg body weight ip produced a decrease in MAP and an increase in HR (P<0.01. Injection of L-NAME (40 µg into the MnPO prior to pilocarpine potentiated the increase in MAP and reduced HR (P<0.01. SNP (30 µg injected into the MnPO prior to pilocarpine attenuated (100% the effect of pilocarpine on MAP, with no effect on HR. Administration of L-NAME (40 µg into the MnPO potentiated the effect of pilocarpine injected ip. SNP (30 µg injected into the MnPO attenuated the effect of ip pilocarpine on MAP and HR. The present study suggests that in the rat MnPO 1 NO is important for the effects of pilocarpine on salivary flow, and 2 pilocarpine interferes with blood pressure and HR (side effects of pilocarpine, that is attenuated by NO.

  3. Synthesis and characterization of the novel rare earth orthophosphates Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Schildhammer, Daniel; Petschnig, Lucas L.; Fuhrmann, Gerda; Heymann, Gunter; Schottenberger, Herwig; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie; Tribus, Martina [Innsbruck Univ. (Austria). Inst. fuer Mineralogie und Petrographie

    2016-02-01

    The new mixed rare earth (RE) orthophosphates Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4} were synthesized by a classical solid state reaction in an electrical furnace at 1200 C. As starting materials, the corresponding rare earth oxides and diammonium hydrogen phosphate were used. The powder diffraction analyses revealed that the new compounds Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4} crystallize in a zircon-type structure being isostructural with the rare earth orthophosphate YPO{sub 4}. Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4} crystallize in the tetragonal space group I4{sub 1}/amd (no. 141) with four formula units in the unit cell. The structural parameters based on Rietveld refinements are a = 687.27(2), c = 601.50(2) pm, V = 0.28412(1) nm{sup 3}, R{sub p} = 0.0143, and R{sub wp} = 0.0186 (all data) for Y{sub 0.5}Er{sub 0.5}PO{sub 4} and a = 684.61(2), c = 599.31(2) pm, V = 0.28089(2) nm{sup 3}, R{sub p} = 0.0242, and R{sub wp} = 0.0313 (all data) for Y{sub 0.5}Yb{sub 0.5}PO{sub 4}. Furthermore, the structure of Y{sub 0.5}Er{sub 0.5}PO{sub 4} was refined from single-crystal X-ray diffraction data: a = 687.78(5), c = 601.85(4) pm, V = 0.28470(5) nm{sup 3}, R{sub 1} = 0.0165, and wR{sub 2} = 0.0385 (all data). In both compounds, the rare earth metal ions are eightfold coordinated by oxygen atoms, forming two unique interlocking tetrahedra with two individual RE-O distances. The tetrahedral phosphate groups [PO{sub 4}]{sup 3-} are slightly distorted in both compounds. The individual rare earth ions share a common position (Wyckoff site 4a). The presence of two rare earth ions in the structures of the new orthophosphates Y{sub 0.5}Er{sub 0.5}PO{sub 4} and Y{sub 0.5}Yb{sub 0.5}PO{sub 4} was additionally confirmed by single-crystal EDX spectroscopy revealing a ratio of 1:1.

  4. Synthesis and magnetic properties of LiFePO4 substitution magnesium

    Science.gov (United States)

    Choi, Hyunkyung; Kim, Min Ji; Hahn, Eun Joo; Kim, Sam Jin; Kim, Chul Sung

    2017-06-01

    LiFe0.9Mg0.1PO4 sample was prepared by using a solid-state reaction method, and the temperature-dependent magnetic properties of the sample were studied. The X-ray diffraction (XRD) pattern showed an olivine-type orthorhombic structure with space group Pnma based on Rietveld refinement method. The effect of Mg substitution in antiferromagnetic LiFe0.9Mg0.1PO4 was investigated using a vibrating sample magnetometer (VSM) and Mössbauer spectroscopy. The temperature-dependence of the magnetization curves of LiFe0.9Mg0.1PO4 shows abnormal antiferromagnetic behavior with ordering temperature. Sudden changes in both the magnetic hyperfine field (Hhf) and its slope below 15 K suggest that magnetic phase transition associated to the abrupt occurrence of spin-reorientation. The Néel temperature (TN) and spin-reorientation temperature (TS) of LiFe0.9Mg0.1PO4 are lower than those of pure LiFePO4 (TN = 51 K, TS = 23 K). This is due to the Fe-O-Fe superexchange interaction being larger than that of the Fe-O-Mg link. Also, we have confirmed a change in the electric quadrupole splitting (ΔEQ) by the spin-orbit coupling effect and the shape of Mössbauer spectrum has provided the evidence for TS and a strong crystalline field. We have found that Mg ions in LiFe0.9Mg0.1PO4 induce an asymmetric charge density due to the presence of Mg2+ ions at the FeO6 octahedral sites.

  5. Structural and spectroscopic properties of MITh2(PO4)32 (M = Cu+, Ag+, Na+, K+)

    International Nuclear Information System (INIS)

    Arsalane, S.; Ziyad, M.

    1996-01-01

    Phosphates of general formulae M I Th 2 (PO 4 ) 3 where M = Cu + and Ag + were synthesized using sol-gel type methods and Cu + /Ag + ion exchange. Their structures were investigated by X-ray diffraction, FTIR, and 31 P MAS NMR spectroscopies. AgTh 2 (PO 4 ) 3 and NaTh 2 (PO 4 ) 3 were found to be isostructural. Their 31 P NMR spectra exhibit three resonances agreeing with the noncentrosymmetric space group Cc to which they belong. On the other hand, CuTh 2 (PO 4 ) 3 does not show a real crystallographic resemblance with the other M I Th 2 (PO 4 ) 3 phosphates of this family. Its 31 P NMR spectrum is similar to that of KTh 2 (PO 4 ) 3 and exhibits two sharp resonances in good agreement with the C2/c space group. Nevertheless, the [PO 4 ] groups in this phosphate are highly distorted because of the linear coordination of the Cu + copper ions

  6. Syntheses, crystal structures, NMR spectroscopy, and vibrational spectroscopy of Sr(PO{sub 3}F).H{sub 2}O and Sr(PO{sub 3}F)

    Energy Technology Data Exchange (ETDEWEB)

    Jantz, Stephan G.; Hoeppe, Henning A. [Lehrstuhl fuer Festkoerperchemie, Institut fuer Physik, Universitaet Augsburg (Germany); Wuellen, Leo van; Fischer, Andreas [Lehrstuhl fuer Chemische Physik und Materialwissenschaften, Institut fuer Physik, Universitaet Augsburg (Germany); Libowitzky, Eugen [Institute for Mineralogy and Crystallography, Faculty of Geosciences, Geography and Astronomy, University of Vienna (Austria); Baran, Enrique J. [Centro de Quimica Inorganica (CEQUINOR/CONICET, UNLP), Facultad de Ciencias Exactas, Universidad Nacional de La Plata (Argentina); Weil, Matthias [Institute for Chemical Technologies and Analytics, Division Structural Chemistry, Vienna University of Technology (Austria)

    2016-03-15

    Single crystals of Sr(PO{sub 3}F).H{sub 2}O {P2_1/c, Z = 4, a = 7.4844(2) Aa, b = 7.0793(2) Aa, c = 8.4265(2) Aa, β = 108.696(1) , V = 422.91(2) Aa"3, 2391 F_o"2, 70 parameters, R_1[F"2 > 2σ(F"2)] = 0.036; wR_2(F"2 all) = 0.049, S = 1.054} were grown from an aqueous solution by a metathesis reaction. The structure comprises [SrO{sub 8}] polyhedra and PO{sub 3}F tetrahedra that form a layered arrangement parallel to (100). The topotactic dehydration of this phase proceeds between 80 and 140 C to afford Sr(PO{sub 3}F). The monazite-type crystal structure of Sr(PO{sub 3}F) was elucidated from the X-ray powder data by simulated annealing [P2{sub 1}/c, Z = 4, a = 6.71689(9) Aa, b = 7.11774(11) Aa, c = 8.66997(13) Aa, β = 128.0063(7) , V = 326.605(8) Aa{sup 3}, R{sub p} = 0.010, R{sub wp} = 0.015, R{sub F} = 0.030]. During dehydration, the structure of Sr(PO{sub 3}F) .H{sub 2}O collapses along [100] from a layered arrangement into a framework structure, accompanied by a change of the coordination number of the Sr{sup 2+} ions from eight to nine. The magic-angle spinning (MAS) NMR and vibrational spectroscopy data of both phases are discussed. (Copyright copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Thermal expansion of phosphates with the NaZr2(PO4)3 structure containing lanthanides and zirconium: R0.33Zr2(PO4)3 (R = Nd, Eu, Er) and Er0.33(1–x) Zr0.25xZr2(PO4)3

    International Nuclear Information System (INIS)

    Volgutov, V. Yu.; Orlova, A. I.

    2015-01-01

    Phosphates R 0.33 Zr 2 (PO 4 ) 3 (R = Nd, Eu, or Er) and Er 0.33(1–x) Zr 0.25 Zr 2 (PO 4 ) 3 (x = 0, 0.25, 0.5, 0.75, 1.0) of the NaZr 2 (PO 4 ) 3 family have been synthesized and investigated by high-temperature X-ray diffraction. The crystallochemical approach is used to obtain compounds with expected small and controllable thermal-expansion parameters. Phosphates with close-to-zero thermal-expansion parameters, including those with low thermal-expansion anisotropy, have been obtained: Nd 0.33 Zr 2 (PO 4 ) 3 with α a =–2.21 × 10 −6 °C −1 , α c = 0.81 × 10 −6 °C −1 , and Δα = 3.02 × 10 −6 °C –1 and Er 0.08 Zr 0.19 Zr 2 (PO 4 ) 3 with α a =–1.86 × 10 −6 °C −1 , α c = 1.73 × 10 −6 °C −1 , and Δα = 3.58 × 10 −6 °C −1

  8. The half-life of 207Bi and decays of 211At and 211Po

    International Nuclear Information System (INIS)

    Yanokura, M.; Kudo, H.; Nakahara, H.; Miyano, K.; Ohya, S.; Nitoh, O.

    1978-01-01

    The half-life of 207 Bi was obtained from the genetic relation between 207 Po and 207 Bi, and between 211 At and 207 Bi. The half-life was found to be 33.4 +- 0.8 y. The half-life of 207 Po was determined to be 5.81 +- 0.04 h by following the decay of the characteristic γ-rays from 207 Po. The half-life of 211 At was determined to be 7.23 +- 0.02 h by following the decay of γ-rays and α-particles from 211 At and 211 Po. The half-lives determined in the present work for 207 Po and 211 At agree with the literature although the half-life of 207 Bi differs considerably from the currently accepted value of 38 y. The branching ratio of 211 At decaying through EC and α-decay modes was determined together with the branching ratios of the three α-particles emitted from 211 Po. (Auth.)

  9. Removal of lead from crude antimony by using NaPo3 as lead elimination reagent

    Directory of Open Access Journals (Sweden)

    Ye L.G.

    2015-01-01

    Full Text Available In order to solve the shortcomings when removing lead from crude antimony in the traditional antimony smelting, a new process was provided using NaPO3 as lead elimination reagent to yield phosphate slag, and it was removed by floating on the surface of the liquid antimony. Reaction mechanism was clarified by using the TG-DTA and XRD techniques and single factor experiments of removal lead from crude antimony were engaged. The results show that PbO and NaPO3 begin endothermic reaction at 863K (590°C, and the reaction mainly form NaPb4(PO43 and NaPbPO4 below 1123K (850°C and above 1123K (850°C, respectively. Sb2O3 and NaPO3 start the reaction at 773K (500°C and generate an antimonic salt compound. The reaction product of the mixture of PbO, Sb2O3 and NaPO3 show that NaPO3 reacted with PbO prior when NaPO3 was insufficient, amorphous antimony glass will be generated only when NaPO3 was adequate. Single factor experiments were taken with NaNO3 as oxidizing agent under argon, effect of reaction time, reaction temperature and dosage of NaPO3 and NaNO3 on smelting results. The average content of lead in refined antimony was 0.05340% and 98.85% of lead were removed under optimal conditions; the content of lead in antimony have meet the requirements of commercial antimony.

  10. Inhalation of 210Po and 210Pb from cigarette smoking in Poland

    International Nuclear Information System (INIS)

    Skwarzec, B.; Ulatowski, J.; Struminska, D.I.; Borylo, A.

    2001-01-01

    The carcinogenic effect of 210 Po and 210 Pb with respect to lung cancer is an important problem in many countries with very high cigarette consumption. Poland has one of the highest consumptions of cigarettes in the world. The results of 210 Po determination on the 14 most frequently smoked brands of cigarettes which constitute over 70% of the total cigarette consumption in Poland are presented and discussed. Moreover, the polonium content in cigarette smoke was estimated on the basis of its activity in fresh tobaccos, ash, fresh filters and post-smoking filters. The annual effective doses were calculated on the basis of 210 Po and 210 Pb inhalation with the cigarette smoke. The results of this work indicate that Polish smokers who smoke one pack (20 cigarettes) per day inhale from 20 to 215 mBq of 210 Po and 210 Pb each. The mean values of the annual effective dose for smokers were estimated to be 35 and 70 μSv from 210 Po and 210 Pb, respectively. For persons who smoke two packs of cigarettes with higher radionuclide concentrations, the effective dose is much higher (471 μSv yr -1 ) in comparison with the intake in diet. Therefore, cigarettes and the absorption through the respiratory system are the main sources and the principal pathway of 210 Po and 210 Pb intake of smokers in Poland

  11. Americium and plutonium in phosphates of trigonal structure (NZP type) Am1/3[Zr2(PO4)3] and Pu1/4[Zr2(PO4)3

    International Nuclear Information System (INIS)

    Bykov, D.M.; Orlova, A.I.; Tomilin, S.V.; Lizin, A.A.; Lukinykh, A.N.

    2006-01-01

    Am 1/3 [Zr 2 (PO 4 ) 3 ] and Pu 1/4 [Zr 2 (PO 4 ) 3 ] phosphates are synthesized and are investigated by X-ray diffraction method. Compounds have triclinic lattices and lattice parameters are determined. Possibility of actinide inclusion into hollows of framework of NZP type is shown for the first time. It is proposed that inclusion of Pu and Am highly-charged cations into framework hollows decreases crystal structure symmetry up to primitive trigonal one. Rate of Pu leaching from ceramics on Pu 1/4 [Zr 2 (PO 4 ) 3 ] basis are measured [ru

  12. Biocarbon-coated LiFePO4 nucleus nanoparticles enhancing electrochemical performances.

    Science.gov (United States)

    Zhang, Xueguang; Zhang, Xudong; He, Wen; Yue, Yuanzheng; Liu, Hong; Ma, Jingyun

    2012-10-18

    We report a simple, inexpensive green biomimetic way for developing the high performance LiFePO(4) for high-power lithium-ion batteries. Biocarbon-coated LiFePO(4) nucleus nanoparticles are synthesized by using yeast cells as both a structural template and a biocarbon source.

  13. 210Po and 210Pb in food chains lichen - reindeer - man

    International Nuclear Information System (INIS)

    Solatie, D.; Yunttila, M.; Vesterbakka, P.

    2006-01-01

    Migration of 210 Po and its precursor 210 Pb from radioactive fallout through food chain lichen - reindeer - man is studied. Samples of lichens, leaves, grass, mushrooms, soils, and samples of reindeer tissues are selected; their specific radioactivity and ratio 210 Po/ 210 Pb are determined [ru

  14. 210Po and 210Pb in Forest Soil and in Wild Berries in Finland

    International Nuclear Information System (INIS)

    Vaaramaa, Kaisa; Lehto, Jukka; Solatie, Dina; Aro, Lasse

    2008-01-01

    The behaviour of 210 Po and 210 Pb was investigated in forests in the Southern Finland site and in the Northern Finland site. Sampling sites were in Scots pine (Pinus sylvestris) forests. Maximum activities of 210 Po and 210 Pb in soil columns were found in organic layers. According to preliminary results of wild berry samples, the lowest 210 Po concentrations were found in berries. The highest concentration of 210 Po was found in stems of the blueberry (Vaccinium myrtillus) and the lingonberry (Vaccinium vitis-idaea) samples

  15. Syntheses and characterizations of LiFePO4 powders

    OpenAIRE

    Jugović, Dragana; Kuzmanović, Maja; Mitrić, Miodrag; Cvjetićanin, Nikola; Uskoković, Dragan

    2011-01-01

    The olivine type compositions LiMPO4 (M = Fe, Mn, Co) are among the most attractive materials for the positive electrode of lithium-ion battery. The benefits of using LiFePO4 are excellent cycle life, high structural stability, low cost and environmental friendliness. Here will be presented our efforts to obtain LiFePO4 powders through several synthesis methods. The differences in phase purity, microstructure, morphology, and electrochemical performances of synthesized powders were investigat...

  16. Baseline concentration of 210Po and 210Pb in Sargassum from the northern Gulf

    International Nuclear Information System (INIS)

    Uddin, S.; Aba, A.; Bebhehani, M.

    2015-01-01

    Highlights: • This is the first baseline for 210 Po and 210 Pb in Sargassum from northern Gulf. • 210 Po concentration in Sargassum boveanum is higher than Sargassum oligocystum. • 210 Pb concentrations in two Sargassum species was not statistically significant. • The concentration factor is microalgae is slightly higher than IAEA recommended value. - Abstract: This baseline study highlights the 210 Po and 210 Pb concentration in two species of the benthic macroalgae Sargassum from northern Gulf, also known as the ROPME Sea Area (RSA). Within the marine environment, 210 Po is initially absorbed from water and concentrated by phytoplankton and macroalgae, and this concentrated 210 Po can then readily be passed along to the higher trophic level of the marine food web. The 210 Po concentration measured in Sargassum boveanum (22.5–25.6 Bq kg −1 ) was higher than that in Sargassum oligocystum (20.2–22.5 Bq kg −1 ), but is not statistically significant (p > 0.064), where as the difference between 210 Pb concentrations in Sargassum boveanum (15.3–16.8 Bq kg −1 ) and Sargassum oligocystum (18.4–22.0 Bq kg −1 ) was statistically significant (p > 0.019). The measured concentration factor for 210 Po in Sargassum in the northern Gulf varied between 0.55 and 1.2 × 10 4 , values higher to the IAEA recommended value of 1 × 10 3 . The 210 Po enrichment is observed in both the species of Sargassum, 210 Po/ 210 Pb ratio was >1 at all the stations for all the samples

  17. Annual effective dose of {sup 210}Po from sea food origin (Oysters and Mussels) in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Bo Eum; Hong, Gi Hoon; Kim, Suk Hyun; Lee, Hyun Mi [Korea Institute of Ocean Science and Technology, Ansan (Korea, Republic of)

    2016-09-15

    Ingestion of {sup 210}Po laden seafood accounts for a substantial amount of the effective dose of {sup 210}Po. Among seafood items, mollusks, especially domestically produced oysters and mussels, are highly enriched in {sup 210}Po and are consumed in large quantities in Korea. Oysters and mussels around the Korean coasts were collected from major farm areas in November 2013. Samples were spiked with an aliquot of {sup 210}Po as a yield tracer, and they were digested with 6 mol·L{sup -1} HNO{sub 3} and H{sub 2}O{sub 2}. The {sup 210}Po and {sup 209}Po were spontaneously deposited onto a silver disc in an acidic solution of 0.5 mol·L{sup -1} HCl and measured using an alpha spectrometer. The activity concentrations of {sup 210}Pb and {sup 210}Po were decay corrected to the sampling date, accounting for the possible in-growth and decay of {sup 210}Po. {sup 210}Po activity concentrations in oysters were in a range from 41.3 to 206 Bq·(kg-ww{sup -1} and mussels in a range from 42.9 to 46.7 Bq·(kg-ww){sup -1}. The {sup 210}Po activity concentration of oysters in the turbid Western coast was higher than the Southern coast. The {sup 210}Po activity concentration of the oysters was positively correlated (R2=0.89) with those of the suspended particulate matter in the surface water. The calculated annual effective dose of {sup 210}Po from oysters and mussels consumed by the Korean population was 21-104 and 5.01-5.46 μSv·y{sup -1}. The combined effective dose due to the consumption of oysters and mussels appears to account for about 35±19% of that arising from seafood consumption in the Korean population. The annual effective dose of {sup 210}Po for oysters in the Korean population was found to be higher than other countries. The total annual effective dose of 210Po{sup 210}Po due to consumption of oysters and mussels consumed in Korea was found to be 76±42 μSv·y{sup -1}, accounting for 28±16% of the total effective dose of {sup 210}Po from food in Korea.

  18. Co3(PO42·4H2O

    Directory of Open Access Journals (Sweden)

    Yang Kim

    2008-10-01

    Full Text Available Single crystals of Co3(PO42·4H2O, tricobalt(II bis[orthophosphate(V] tetrahydrate, were obtained under hydrothermal conditions. The title compound is isotypic with its zinc analogue Zn3(PO42·4H2O (mineral name hopeite and contains two independent Co2+ cations. One Co2+ cation exhibits a slightly distorted tetrahedral coordination, while the second, located on a mirror plane, has a distorted octahedral coordination environment. The tetrahedrally coordinated Co2+ is bonded to four O atoms of four PO43− anions, whereas the six-coordinate Co2+ is cis-bonded to two phosphate groups and to four O atoms of four water molecules (two of which are located on mirror planes, forming a framework structure. In addition, hydrogen bonds of the type O—H...O are present throughout the crystal structure.

  19. Chemically grafted carbon-coated LiFePO4 using diazonium chemistry

    Science.gov (United States)

    Delaporte, Nicolas; Perea, Alexis; Amin, Ruhul; Zaghib, Karim; Bélanger, Daniel

    2015-04-01

    The effect of surface functionalization of aminophenyl and bromophenyl groups on carbon-coated LiFePO4 and the electrochemical properties of composite electrode containing these materials are reported. The functionalization was performed by spontaneous reduction of the corresponding in situ generated diazonium ions. The resulting chemically grafted LiFePO4/C materials were characterized by energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) to confirm the presence of the surface organic species. XRD analyses indicated the cathode material was partially oxidized. Thermogravimetric and elemental analyses revealed the loading of grafted molecules was between 0.2 and 1.1 wt.% depending on the reaction conditions. Interestingly, the electrochemical performances of the modified LiFePO4/C are not adversely affected by the presence of either aminophenyl and bromophenyl groups at the carbon surface, and in fact the grafted LiFePO4/C displayed slightly superior discharge capacity at the highest C rate investigated for a low loading of organic molecules.

  20. Quantitative evaluation of 218Po behaviour in air in an artificial environment

    International Nuclear Information System (INIS)

    Yajima, K.; Hirao, S.; Moriizumi, J.; Yamazawa, H.

    2015-01-01

    Experiments were carried out in a small enclosed booth for the purpose of understanding and modelling 218 Po behaviour. The experiment was conducted under two kinds of conditions without and with injection of incense smoke. A working model of 218 Po behaviour was applied to analyse the measured data. Under the condition without incense smoke, temporal changes in aerosol-attached and unattached 218 Po concentrations were successfully reproduced by the model. The deposition rate of unattached fraction and the rate of attachment were determined by the working model. Under the condition with incense smoke, temporal changes in 218 Po concentration were poorly simulated by the model. This can be attributed to the significantly increased aerosol concentration in small size ranges which is not properly considered in the attachment rate calculation in the model. (authors)

  1. Moessbauer study of FePO4 cathode for lithium- and sodium-ion batteries

    International Nuclear Information System (INIS)

    Tetsuaki Nishida; Masahiro Tokunaga; Toshiharu Nishizumi; Takafumi Yamamoto; Tomoyuki Shiratsuchi; Shigeto Okada; Jun-ichi Yamaki

    2005-01-01

    LiFePO 4 of olivine type has attracted much interest as a rare-metal free cathode for lithium-ion battery. The present authors' group has found a low-cost preparation method for new cathode material FePO 4 (P 321 ) from an aqueous solution of metallic iron and P 2 O 5 . A cathode pellet was prepared by mixing FePO 4 , acetylene black (AB) and polytetrafluoroethylene (PTFE) binder at a mass ratio of 70:25:5. Electrochemical cathode performance was investigated under a constant current density of 0.1 mA/cm 2 with a coin-type cell with an anode of metallic Li and Na for Li- and Na-ion batteries, respectively. Moessbauer spectra were measured by a constant accele- ration method with a Moessbauer source of 57 Co(Pd) and an α-Fe foil as a reference of the isomer shift. Moessbauer spectra of the original cathode pellet top left and right) composed of amorphous FePO 4 indicate that all the Fe III atoms have a tetrahedral symmetry. After discharging the Li-(second left) and Na-batteries (second right), all the Fe III were reduced to octahedral Fe II . The reduction of Fe III to Fe II indicates penetration of Li + and Na + into the FePO 4 cathode which accompanies an electron capture; Li + (or Na + ) + Fe III PO 4 + e - = LiFe II PO 4 (or NaFe II PO 4 ) After charging the Li-cell (bottom left), all the Fen atoms were oxidized to tetrahedral Fe III , while 69 % of Fe II was oxidized to Fe III in the Na-ion cell (bottom right) due to a lower cell voltage: 4.0 V. Oxidation of Fe II to Fe III reflects a release of Li + or Na + ions from the FePO 4 cathode to the electrolyte, i.e., an inverse reaction of eq.

  2. In pursuit of the rhabdophane crystal structure: from the hydrated monoclinic LnPO{sub 4}.0.667H{sub 2}O to the hexagonal LnPO{sub 4} (Ln = Nd, Sm, Gd, Eu and Dy)

    Energy Technology Data Exchange (ETDEWEB)

    Mesbah, Adel, E-mail: adel.mesbah@cea.fr [ICSM, UMR 5257 CNRS – CEA – ENSCM – Université de Montpellier, Site de Marcoule - Bât 426, BP 17171, 30207 Bagnols/Cèze (France); Clavier, Nicolas [ICSM, UMR 5257 CNRS – CEA – ENSCM – Université de Montpellier, Site de Marcoule - Bât 426, BP 17171, 30207 Bagnols/Cèze (France); Elkaim, Erik [Synchrotron SOLEIL, L' Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Szenknect, Stéphanie; Dacheux, Nicolas [ICSM, UMR 5257 CNRS – CEA – ENSCM – Université de Montpellier, Site de Marcoule - Bât 426, BP 17171, 30207 Bagnols/Cèze (France)

    2017-05-15

    The dehydration process of the hydrated rhabdophane LnPO{sub 4}.0.667H{sub 2}O (Ln = La to Dy) was thoroughly studied over the combination of in situ high resolution synchrotron powder diffraction and TGA experiments. In the case of SmPO{sub 4}.0.667H{sub 2}O (monoclinic, C2), a first dehydration step was identified around 80 °C leading to the formation of SmPO{sub 4}.0.5H{sub 2}O (Monoclinic, C2) with Z =12 and a =17.6264(1) Å, b =6.9704(1) Å, c =12.1141(1) Å, β=133.74(1) °, V =1075.33(1) Å{sup 3}. In agreement with the TGA and dilatometry experiments, all the water molecules were evacuated above 220 °C yielding to the anhydrous form, which crystallizes in the hexagonal P3{sub 1}21 space group with a =7.0389(1) Å, c =6.3702(1) Å and V =273.34(1) Å{sup 3}. This study was extended to selected LnPO{sub 4}.0.667H{sub 2}O samples (Ln= Nd, Gd, Eu, Dy) and the obtained results confirmed the existence of two dehydration steps before the stabilization of the anhydrous form, with the transitory formation of LnPO{sub 4}.0.5H{sub 2}O. - Graphical abstract: The dehydration process of the rhabdophane SmPO{sub 4}.0.667H{sub 2}O was studied over combination of in situ high resolution synchrotron powder diffraction and TGA techniques, a first dehydration was identified around 80 °C leading to the formation of SmPO{sub 4}.0.5H{sub 2}O (Monoclinic, C2). Then above 220 °C, the anhydrous form of the rhabdophane SmPO{sub 4} was stabilized and crystallizes in the hexagonal P3{sub 1}21 space group. - Highlights: • In situ synchrotron powder diffraction was carried out during the dehydration of the rhabdopahe LnPO{sub 4}.0.667H{sub 2}O. • The heat of the rhabdophane LnPO{sub 4}.0.667H{sub 2}O leads to LnPO{sub 4}.0.5H{sub 2}O then to anhydrous rhabdophane LnPO{sub 4}. • LnPO{sub 4}.0.5H{sub 2}O (monoclinic, C2) and LnPO{sub 4} (Hexagonal, P3{sub 1}21) were solved over the use of direct methods.

  3. A chemically activated graphene-encapsulated LiFePO4 composite for high-performance lithium ion batteries.

    Science.gov (United States)

    Ha, Jeonghyun; Park, Seung-Keun; Yu, Seung-Ho; Jin, Aihua; Jang, Byungchul; Bong, Sungyool; Kim, In; Sung, Yung-Eun; Piao, Yuanzhe

    2013-09-21

    A composite of modified graphene and LiFePO4 has been developed to improve the speed of charging-discharging and the cycling stability of lithium ion batteries using LiFePO4 as a cathode material. Chemically activated graphene (CA-graphene) has been successfully synthesized via activation by KOH. The as-prepared CA-graphene was mixed with LiFePO4 to prepare the composite. Microscopic observation and nitrogen sorption analysis have revealed the surface morphologies of CA-graphene and the CA-graphene/LiFePO4 composite. Electrochemical properties have also been investigated after assembling coin cells with the CA-graphene/LiFePO4 composite as a cathode active material. Interestingly, the CA-graphene/LiFePO4 composite has exhibited better electrochemical properties than the conventional graphene/LiFePO4 composite as well as bare LiFePO4, including exceptional speed of charging-discharging and excellent cycle stability. That is because the CA-graphene in the composite provides abundant porous channels for the diffusion of lithium ions. Moreover, it acts as a conducting network for easy charge transfer and as a divider, preventing the aggregation of LiFePO4 particles. Owing to these properties of CA-graphene, LiFePO4 could demonstrate enhanced and stably long-lasting electrochemical performance.

  4. Continuous flame aerosol synthesis of carbon-coated nano-LiFePO4 for Li-ion batteries

    Science.gov (United States)

    Waser, Oliver; Büchel, Robert; Hintennach, Andreas; Novák, Petr; Pratsinis, Sotiris E.

    2013-01-01

    Core-shell, nanosized LiFePO4-carbon particles were made in one step by scalable flame aerosol technology at 7 g/h. Core LiFePO4 particles were made in an enclosed flame spray pyrolysis (FSP) unit and were coated in-situ downstream by auto thermal carbonization (pyrolysis) of swirl-fed C2H2 in an O2-controlled atmosphere. The formation of acetylene carbon black (ACB) shell was investigated as a function of the process fuel-oxidant equivalence ratio (EQR). The core-shell morphology was obtained at slightly fuel-rich conditions (1.0 < EQR < 1.07) whereas segregated ACB and LiFePO4 particles were formed at fuel-lean conditions (0.8 < EQR < 1). Post-annealing of core-shell particles in reducing environment (5 vol% H2 in argon) at 700 °C for up to 4 hours established phase pure, monocrystalline LiFePO4 with a crystal size of 65 nm and 30 wt% ACB content. Uncoated LiFePO4 or segregated LiFePO4-ACB grew to 250 nm at these conditions. Annealing at 800 °C induced carbothermal reduction of LiFePO4 to Fe2P by ACB shell consumption that resulted in cavities between carbon shell and core LiFePO4 and even slight LiFePO4 crystal growth but better electrochemical performance. The present carbon-coated LiFePO4 showed superior cycle stability and higher rate capability than the benchmark, commercially available LiFePO4. PMID:23407817

  5. Krwotok położniczy – zasady współpracy położnika i anestezjologa

    Directory of Open Access Journals (Sweden)

    Elżbieta Nowacka

    2012-04-01

    Full Text Available Krwotok położniczy wciąż jest jedną z najczęstszych przyczyn zgonów ciężarnych irodzących. Prawie 88% kobiet umiera w ciągu pierwszych czterech godzin od momentu jego wystąpienia. Znajomość mechanizmów regulują‑ cych homeostazę ustroju ciężarnej ma ogromne znaczenie w postępowaniu terapeutycznym w przypadku wystą‑ pienia krwotoku okołoporodowego. O tym, jak trudno rozpoznać i zdefiniować krwotok położniczy, dowodzi obecność kilkunastu różnych jego definicji. Z punktu widzenia zmian hemodynamicznych, następstw ogólno‑ ustrojowych i konieczności podjęcia określonych decyzji terapeutycznych bardzo użyteczne wydają się pojęcia oceniające szybkość utraty wokreślonym przedziale czasowym: skumulowana utrata krwi wynosząca 150 ml/min lub 1,5 ml/kg m.c./min oraz utrata 50% objętości krwi krążącej w ciągu 3 godzin. Rokowanie w krwotoku położ‑ niczym zależy od wielu elementów, do których zaliczamy: szybkie rozpoznanie, powiadomienie i wdrożenie algo‑ rytmu postępowania terapeutycznego oraz efektywne działanie interdyscyplinarne różnych zespołów biorących udział w procesie diagnostyczno‑leczniczym. Niezbędna jest jednoczasowa, efektywna współpraca doświadczo‑ nego zespołu anestezjologicznego, ginekologiczno‑położniczego, bloku operacyjnego, zespołów pracowni dia‑ gnostyczno‑laboratoryjnych oraz regionalnego centrum krwiodawstwa. Skoordynowanie pracy dużej liczby ludzi, często „rozrzuconych” w strukturach organizacyjnych szpitala na różnych piętrach lub w oddzielnych budyn‑ kach, jest niezmiernie trudne. Opracowanie algorytmu postępowania uwzględniającego kolejność i sposób powiadamiania oraz wdrażanie określonych procedur w poszczególnych jednostkach organizacyjnych decydu‑ ją o przeżyciu pacjentki i późniejszej jakości życia. Większość czynności w ciężkim krwotoku położniczym (resu‑ scytacja, monitorowanie, opanowywanie

  6. Occurrence of ²¹⁰Po and biological effects of low-level exposure: the need for research.

    Science.gov (United States)

    Seiler, Ralph L; Wiemels, Joseph L

    2012-09-01

    Polonium-210 (²¹⁰Po) concentrations that exceed 1 Bq/L in drinking-water supplies have been reported from four widely separated U.S. states where exposure to it went unnoticed for decades. The radionuclide grandparents of ²¹⁰Po are common in sediments, and segments of the public may be chronically exposed to low levels of ²¹⁰Po in drinking water or in food products from animals raised in contaminated areas. We summarized information on the environmental behavior, biokinetics, and toxicology of ²¹⁰Po and identified the need for future research. Potential linkages between environmental exposure to ²¹⁰Po and human health effects were identified in a literature review. ²¹⁰Po accumulates in the ovaries where it kills primary oocytes at low doses. Because of its radiosensitivity and tendency to concentrate ²¹⁰Po, the ovary may be the critical organ in determining the lowest injurious dose for ²¹⁰Po. ²¹⁰Po also accumulates in the yolk sac of the embryo and in the fetal and placental tissues. Low-level exposure to ²¹⁰Po may have subtle, long-term biological effects because of its tropism towards reproductive and embryonic and fetal tissues where exposure to a single alpha particle may kill or damage critical cells. ²¹⁰Po is present in cigarettes and maternal smoking has several effects that appear consistent with the toxicology of ²¹⁰Po. Much of the important biological and toxicological research on ²¹⁰Po is more than four decades old. New research is needed to evaluate environmental exposure to ²¹⁰Po and the biological effects of low-dose exposure to it so that public health officials can develop appropriate mitigation measures where necessary.

  7. 210Po in cigarette and the radiation dose inhaled by smoker

    International Nuclear Information System (INIS)

    Wang Xin; Chen Xingan; Pan Yingdong

    2000-01-01

    The contents of Polonium-210 in 16 brands of cigarettes from China and 4 brands of cigarettes from abroad were reported. The method that the authors used for separating Polonium-210 was electrochemical deposition method. The 210 Po contents were analyzed in whole cigarettes from freshly opened packs. The 210 Po contents of the China-made cigarettes ranged from 13.7 to 43.4 mBq/cig, from 18.0 to 67.3 mBq/g respectively, the mean values were 26.5 mBq/cig and 33.7 mBq/g respectively. The content of 210 Po in cigarettes from China is higher than that from abroad. The polonium contents of the ash, butt and main stream smoke were reported. The cigarettes were smoked with the eight-channel smoking machine for determining the concentration of the radionuclides in main stream smoke. ('Main Stream' means smoke taken into the mouth). About 15% of 210 Po contained in a cigarette was transferred into the main stream smoke, 40% of the whole 210 Po content remained in the ash and butt for filter cigarette, 60% for non-filter. The daily intake of the 210 Po from cigarette was 80 mBq, the annual dose equivalent to the lung tissue of human body was 0.46 mSv. In view of present knowledge, it is improbable that this dose is significant for the higher incidence of lung tissue of human body was 0.46 mSv. In view of present knowledge, it is improbable that this dose is significant for the higher incidence of lung cancer in smokers

  8. Dependence of 210Po activity on organic matter in the reverine environs of coastal Kerala

    International Nuclear Information System (INIS)

    Narayana, Y.; Venunathan, N.

    2011-01-01

    This paper deals with the distribution of 210 Po in the river bank soil samples of three major rivers namely Bharathapuzha, Periyar and Kallada river of Kerala. The dependence of 210 Po activity on organic matter content in the samples was also studied. The soil samples were collected and analyzed for 210 Po radionuclide using standard radiochemical analytical method. Activity of 210 Po increases with increase in organic matter content in samples. Along the Bharathapuzha river bank the 210 Po activity ranges from 2.96 to 12.48 Bq kg -1 with mean 5.62 Bq kg -1 . The organic matter percentage in the samples ranges from 0.4 to 2.8 and a good correlation with correlation coefficient 0.9 was found between activity and organic matter percentage. In the Periyar river environs 210 Po activity ranges from 3.47 to 13.39 Bq kg -1 with mean value 9.27 Bq kg -1 . Organic matter percentage in these samples ranges from 1.20 to 4.10 and the correlation coefficient between 210 Po activity and organic matter percentage was found to be 0.8 In the Kallada river bank soil samples 210 Po activity ranges from 4.46 to 6.45 Bq kg -1 . The organic matter percentage ranges from 1.4 to 3. The correlation coefficient between 210 Po activity and organic matter percentage in the samples was found to be 0.9. (author)

  9. Preparation and photocatalytic degradation performance of Ag_3PO_4 with a two-step approach

    International Nuclear Information System (INIS)

    Li, Jiwen; Ji, Xiaojing; Li, Xian; Hu, Xianghua; Sun, Yanfang; Ma, Jingjun; Qiao, Gaowei

    2016-01-01

    Highlights: • Ag_3PO_4 photocatalysts were synthesized via one-step and two-step ion-exchange reaction. • Photocatalytic properties of Ag_3PO_4 photocatalysts was investigated, the result indicated the Ag_3PO_4 (2) was higher than that of Ag_3PO_4 (1) under the same experimental condition. • Ag_3PO_4 (2) particles were larger than Ag_3PO_4 (1) particles and many polygonal-shaped surfaces could be clearly observed in the Ag_3PO_4 (2) particles. - Abstract: Ag_3PO_4 photocatalysts were prepared via two and one-step through a facile ion-exchange route. The photocatalysts were then characterized through powder X-ray diffraction, scanning electron microscopy and UV–vis diffuse reflectance spectroscopy. The photocatalytic activity of the samples was evaluated on the basis of the photocatalytic degradation of methyl orange (MO) and methylene blue (MB) under solar irradiation. The MO degradation rate of the Photocatalyst synthesized by the two-step ion-exchange route was 89.18% in 60 min. This value was four times that of the Photocatalyst synthesized by the one-step approach.The MB degradation rate was 97% in 40 min. After six cycling runs were completed, the MO degradation rate was 73%

  10. doped LiMgPO4 phosphor

    Indian Academy of Sciences (India)

    attention because of their remarkable luminescence proper- ties and .... Figure 1. (a) X-ray diffraction patterns of LiMgPO4:Tb3+ phosphor and (b) standard data. ICDD file. .... ground signal which affects the signal to noise ratio [17]. MDD was ...

  11. Synthesis, structures and properties of the new lithium cobalt(II) phosphate Li4Co(PO4)2

    International Nuclear Information System (INIS)

    Glaum, R.; Gerber, K.; Schulz-Dobrick, M.; Herklotz, M.; Scheiba, F.; Ehrenberg, H.

    2012-01-01

    α-Li 4 Co(PO 4 ) 2 has been synthesized and crystallized by solid-state reactions. The new phosphate crystallizes in the monoclinic system (P2 1 /a, Z=4, a=8.117(3) Å, b=10.303(8) Å, c=8.118(8) Å, β=104.36(8) Å) and is isotypic to α-Li 4 Zn(PO 4 ) 2 . The structure of α-Li 4 Co(PO 4 ) 2 has been determined from single-crystal X-ray diffraction data {R 1 =0.040, wR 2 =0.135, 2278 unique reflections with F o >4σ(F o )}. The crystal structure, which might be regarded as a superstructure of the wurtzite structure type, is build of layers of regular CoO 4 , PO 4 and Li1O 4 tetrahedra. Lithium atoms Li2, Li3 and Li4 are located between these layers. Thermal investigations by in-situ XRPD, DTA/TG and quenching experiments suggest decomposition followed by formation and phase transformation of Li 4 Co(PO 4 ) 2 : α-Li 4 Co(PO 4 ) 2 ⟹ 442°C β-Li 3 PO 4 +LiCoPO 4 ⇌ 773°C β-Li 4 Co(PO 4 ) 2 ⟹ quenchingto25°C α-Li 4 Co(PO 4 ) 2 According to HT-XRPD at θ=850°Cβ-Li 4 Co(PO 4 ) 2 (Pnma, Z=2, 10.3341(8) Å, b=6.5829(5) Å, c=5.0428(3) Å) is isostructural to γ-Li 3 PO 4 . The powder reflectance spectrum of α-Li 4 Co(PO 4 ) 2 shows the typical absorption bands for the tetrahedral chromophore [Co II O 4 ]. - Graphical abstract: The complex formation and decomposition behavior of Li 4 Co(PO 4 ) 2 with temperature has been elucidated. The crystal structure of its α-phase was determined from single crystal data, HT-XRPD allowed derivation of a structure model for the β-phase. Both modifications belong to the Li 3 PO 4 structure family. Highlights: ► Li 4 Co(PO 4 ) 2 exhibits complex thermal behavior. ► The new phosphate belongs to the Li 3 PO 4 structure family. ► A single-crystal structure analysis is provided for the metastable α-Li 4 Co(PO 4 ) 2 . ► From HT-XRPD data a cation distribution model is developed for β-Li 4 Co(PO 4 ) 2 . ► No electrochemical delithiation is observed up to 5 V.

  12. Modeling Li-ion conductivity in LiLa(PO{sub 3}){sub 4} powder

    Energy Technology Data Exchange (ETDEWEB)

    Mounir, Ferhi, E-mail: ferhi.mounir@gmail.com [Laboratoire de Physicochimie des Materiaux Mineraux et leurs Applications, Centre National des Recherches en Sciences des Materiaux, BP No. 73, 8027 Soliman (Tunisia); Karima, Horchani-Naifer [Laboratoire de Physicochimie des Materiaux Mineraux et leurs Applications, Centre National des Recherches en Sciences des Materiaux, BP No. 73, 8027 Soliman (Tunisia); Khaled, Ben Saad [Laboratoire de Photovoltaieque, Centre des Recherches et des Technologies de l' Energie, Technopole Borj Cedria, BP No. 95, 2050 Hammam Lif (Tunisia); Mokhtar, Ferid [Laboratoire de Physicochimie des Materiaux Mineraux et leurs Applications, Centre National des Recherches en Sciences des Materiaux, BP No. 73, 8027 Soliman (Tunisia)

    2012-07-01

    Polycrystalline powder and single-crystal of LiLa(PO{sub 3}){sub 4} are synthesized by solid state reaction and flux technique, respectively. A morphological description of the obtained product was made based on scanning electron microscopy micrographs. The obtained powder was characterized by X-ray powder diffraction, FTIR and Raman spectroscopies. Ionic conductivity of the LiLa(PO{sub 3}){sub 4} powder was measured and evaluated over a temperature range from 553 to 913 K. Single crystals of LiLa(PO{sub 3}){sub 4} are characterized by single-crystal X-ray diffraction. The LiLa(PO{sub 3}){sub 4} structure was found to be isotypic with LiNd(PO{sub 3}){sub 4}. It crystallizes in the monoclinic system with space group C2/c and cell parameters: a=16.635(6) A, b=7.130(3) A, c=9.913(3) A, {beta}=126.37(4) Degree-Sign , V=946.72(6) A{sup 3} and Z=4. The LiLa(PO{sub 3}){sub 4} structure was described as an alternation between spiraling chains (PO{sub 3}){sub n} and (La{sup 3+}, Li{sup +}) cations along the b direction. The small Li{sup +} ions, coordinated to four oxygen atoms, were located in the large connected cavities created between the LaO{sub 8} polyhedra and the polyphosphate chains. The jumping of Li{sup +} through tunnels of the crystalline network was investigated using complex impedance spectroscopy. The close value of the activation energies calculated through the analysis of conductivity data and loss spectra indicate that the transport in the investigated system is through hopping mechanism. The correlation between ionic conductivity of LiLa(PO{sub 3}){sub 4} and its crystallographic structure was investigated and the most probably transport pathway model was determined.

  13. The subcellular localization of natural 210Po in the hepatopancreas of the rock lobster (Jasus lalandii)

    International Nuclear Information System (INIS)

    Heyraud, M.; Dowdle, E.B.; Cherry, R.D.

    1987-01-01

    The subcellular localization of the naturally occurring nuclide 210 Po in the hepatopancreas of the South African rock lobster, Jasus lalandii, has been studied using centrifugation, ultrafiltration and chromatography. Just over half of the 210 Po was found to be associated with a component in the microsomal pellet. Most of the 210 Po was tightly bound to a component of high molecular mass. Dissociation of the 210 Po from this component required incubation with sulphydryl-reducing reagents, after which the 210 Po appeared to associate with a fraction having a molecular mass of 1500 daltons or less. A search for negatively-charged, hydrophobic, sulphur-containing membrane proteins which bind 210 Po is suggested. (author)

  14. Subcellular localization of natural /sup 210/Po in the hepatopancreas of the rock lobster (Jasus lalandii)

    Energy Technology Data Exchange (ETDEWEB)

    Heyraud, M; Dowdle, E B; Cherry, R D

    1987-01-01

    The subcellular localization of the naturally occurring nuclide /sup 210/Po in the hepatopancreas of the South African rock lobster, Jasus lalandii, has been studied using centrifugation, ultrafiltration and chromatography. Just over half of the /sup 210/Po was found to be associated with a component in the microsomal pellet. Most of the /sup 210/Po was tightly bound to a component of high molecular mass. Dissociation of the /sup 210/Po from this component required incubation with sulphydryl-reducing reagents, after which the /sup 210/Po appeared to associate with a fraction having a molecular mass of 1500 daltons or less. A search for negatively-charged, hydrophobic, sulphur-containing membrane proteins which bind /sup 210/Po is suggested.

  15. Optical and crystal chemistry studies of Na3Ln(PO4)2-K3Ln(PO4)2 (Ln=Eu, Gd)

    International Nuclear Information System (INIS)

    Mesnaoui, M.; Maazaz, M.

    1987-01-01

    In these systems, large single phase domains are separated by two phase regions. The structural evolution as a function of composition is analysed both by X-ray diffraction and by using Eu 3+ and Gd 3+ as luminescent local structural probes. Due to layer type structure of the K 3 Ln(PO 4 ) 2 phases an exchange reaction resulting in total substitution of sodium for potassium can be carried out with formation of metastable Na 3 Ln(PO 4 ) 2 phases, the structure of which is close to those of the potassium compounds. 10 refs.; 18 figs [fr

  16. Some redox chemistry of HPO2-. and .PO32- radicals. A pulse radiolysis study

    International Nuclear Information System (INIS)

    Packer, J.E.; Anderson, R.F.

    1990-01-01

    The HO . radical oxidises hypophosphite and phosphite anions to HPO 2 -. and . PO 3 2- respectively, but Br 2 -. and N 3 . do not. The rates of oxidation of HPO 2 -. by a series of oxidising agents of known one electron redox potentials decrease with decreasing potential while the corresponding rates for oxidation of . PO 3 2- remain close to the diffusion controlled limit. . PO 3 2- will oxidise cysteine but HPO 2 -. does not. . PO 3 2- did not oxidise ABTS, ascorbate, or the anion of the vitamin E analogue, trolox. It reduced traces of TMPD +. in TMPD rather than oxidising the substrate. The one electron redox potentials for oxidation and reduction of . PO 3 2- are calculated in light of recently published redox data on penicillamine. (author)

  17. Structural and electrochemical properties of Cl-doped LiFePO{sub 4}/C

    Energy Technology Data Exchange (ETDEWEB)

    Sun, C.S.; Zhang, Y.; Zhang, X.J.; Zhou, Z. [Institute of New Energy Material Chemistry, Nankai University, Tianjin 300071 (China)

    2010-06-01

    Cl-doped LiFePO{sub 4}/C cathode materials were synthesized through a carbothermal reduction route, and the microstructure and electrochemical performances were systematically studied. Cl-doped LiFePO{sub 4}/C cathode materials presented a high discharge capacity of {proportional_to}90 mAh g{sup -1} at the rate of 20 C (3400 mA g{sup -1}) at room temperature. Electrochemical impedance spectroscopy and cyclic voltamperometry indicated the optimized electrochemical reaction and Li{sup +} diffusion in the bulk of LiFePO{sub 4} due to Cl-doping. The improved Li{sup +} diffusion capability is attributed to the microstructure modification of LiFePO{sub 4} via Cl-doping. (author)

  18. Single-crystalline LiFePO4 nanosheets for high-rate Li-ion batteries.

    Science.gov (United States)

    Zhao, Yu; Peng, Lele; Liu, Borui; Yu, Guihua

    2014-05-14

    The lithiation/delithiation in LiFePO4 is highly anisotropic with lithium-ion diffusion being mainly confined to channels along the b-axis. Controlling the orientation of LiFePO4 crystals therefore plays an important role for efficient mass transport within this material. We report here the preparation of single crystalline LiFePO4 nanosheets with a large percentage of highly oriented {010} facets, which provide the highest pore density for lithium-ion insertion/extraction. The LiFePO4 nanosheets show a high specific capacity at low charge/discharge rates and retain significant capacities at high C-rates, which may benefit the development of lithium batteries with both favorable energy and power density.

  19. Photoluminescence and thermoluminescence characterization of Eu3+- and Dy3+ -activated Ca3(PO4)2 phosphor

    International Nuclear Information System (INIS)

    Nagpure, I.M.; Saha, Subhajit; Dhoble, S.J.

    2009-01-01

    Rare-earth-doped polycrystalline Ca 3 (PO 4 ) 2 :Eu, Ca 3 (PO 4 ) 2 :Dy and Ca 3 (PO 4 ) 2 :Eu,Dy phosphors prepared by a modified solid-state synthesis has been studied for its X-ray diffraction, thermoluminescence (TL) and photoluminescence (PL) characteristics. The PL emission spectra of the phosphor suggest the presence of Eu 3+ ion in Ca 3 (PO 4 ) 2 :Eu and Dy 3+ ion in Ca 3 (PO 4 ) 2 :Dy lattice sites. The TL glow curve of the Ca 3 (PO 4 ) 2 :Eu compounds has a simple structure with a prominent peak at 228 deg. C, while Ca 3 (PO 4 ) 2 :Dy peaking at 146 and 230 deg. C. TL sensitivity of phosphors are compared with CaSO 4 : Dy and found 1.52 and 1.20 times less in Ca 3 (PO 4 ) 2 :Eu and Ca 3 (PO 4 ) 2 :Dy phosphors, respectively. The Ca 3 (PO 4 ) 2 :Eu,Dy phosphors shows switching behavior under two different excitation wavelengths and enhancement in PL intensity of Dy 3+ ions were reported. The paper discusses the photoluminescence and thermoluminescence behavior of Eu 3+ and Dy 3+ ion in Ca 3 (PO 4 ) 2 hosts, it may be applicable to solid-state lighting as well as thermoluminescence dosimetry applications.

  20. CdZnTe background measurements at balloon altitudes with PoRTIA

    International Nuclear Information System (INIS)

    Parsons, A.; Barthelmy, S.; Bartlett, L.; Gehrels, N.; Naya, J.; Stahle, C.M.; Tueller, J.; Teegarden, B.

    2004-01-01

    Measurements of the CdZnTe internal background at balloon altitudes are essential to determine which physical processes make the most important background contributions. We present results from CdZnTe background measurements made by PoRTIA, a small CdZnTe balloon instrument that was flown three times in three different shielding configurations. PoRTIA was passively shielded during its first flight from Palestine, Texas and actively shielded as a piggyback instrument on the GRIS balloon experiment during its second and third flights from Alice Springs, Australia, using the thick GRIS NaI anticoincidence shield. A significant CdZnTe background reduction was achieved during the third flight with PoRTIA placed completely inside the GRIS shield and blocking crystal, and thus completely surrounded by 15 cm of NaI. A unique balloon altitude background data set is provided by CdZnTe and Ge detectors simultaneously surrounded by the same thick anticoincidence shield; the presence of a single coaxial Ge detector inside the shield next to PoRTIA allowed a measurement of the ambient neutron flux inside the shield throughout the flight. These neutrons interact with the detector material to produce isomeric states of the Cd, Zn, and Te nuclei that radiatively decay; calculations are presented to determine the relative contribution of these decays to the fully shielded CdZnTe background measured by PoRTIA

  1. Šausmu estētika E.A.Po darbos

    OpenAIRE

    Pērkone, Jana

    2007-01-01

    Bailes ir viena no spēcīgākajām cilvēka emocijām, tādēļ tās tiek aplūkotas daudzos literatūras veidos, sākot no folkloras un beidzot ar šausmu stāstiem. Viens no labakājiem šausmu stāstu autoriem ir amerikānis Edgars Alans Po. Viņa devums literatūrā tiek vērtēts pretrunīgi, tādēļ ir interesanti tuvāk izpētīt Po darbu īpatnības. Šajā bakalaura darbā tiek apskatīta šausmu literatūras veidu attīstība un E.A. Po vieta un loma šajā procesā. Bakalaura darba mērķis ir atrast šausmu literatūras e...

  2. Hydroxyapatite supported Ag3PO4 nanoparticles with higher visible light photocatalytic activity

    International Nuclear Information System (INIS)

    Hong Xiaoting; Wu Xiaohui; Zhang Qiuyun; Xiao Mingfeng; Yang Gelin; Qiu Meirong; Han Guocheng

    2012-01-01

    Hydroxyapatite supported Ag 3 PO 4 nanocomposites have been synthesized by a wet impregnation process. UV-vis absorption spectra show a red shift of the absorption edges for the composite systems compared to pure hydroxyapatite support. The surface structure and morphology of the nanocomposites were characterized by Brunauer-Emmett-Teller (BET) apparatus, X-ray diffraction (XRD), transmission electron microscopy (TEM). The results suggest that Ag 3 PO 4 nanoparticles (6-17 nm in diameter) are well dispersed on the hydroxyapatite support and Ag 3 PO 4 nanoparticles density is larger for the higher Ag + loading sample. The as-prepared nanocomposite photocatalysts showed a pronounced photocatalytic activity upon decomposition of methylene blue dye in aqueous solution under both visible light (wavelength > 400 nm) and UV-vis light irradiation. A synergic mechanism of inherent photocatalytic capability of Ag 3 PO 4 and the accelerated electron/hole separation resulting from the photoinduced electrons captured by the slow-released Ag + at the interface of Ag 3 PO 4 and hydroxyapatite is proposed for the nanocomposites on the enhancement of photocatalytic performance in comparison to that of pure Ag 3 PO 4 nanoparticles. The support of hydroxyapatite may also act as an absorbent which favors the mass transfer in heterogeneous photocatalysis reaction.

  3. Levels and transfer of 210Po and 210Pb in Nordic terrestrial ecosystems

    International Nuclear Information System (INIS)

    Brown, J.E.; Gjelsvik, R.; Roos, P.; Kalas, J.A.; Outola, I.; Holm, E.

    2011-01-01

    Recent developments regarding environmental impact assessment methodologies for radioactivity have precipitated the need for information on levels of naturally occurring radionuclides within and transfer to wild flora and fauna. The objectives of this study were therefore to determine activity concentrations of the main dose forming radionuclides 210 Po and 210 Pb in biota from terrestrial ecosystems thus providing insight into the behaviour of these radioisotopes. Samples of soil, plants and animals were collected at Dovrefjell, Central Norway and Olkiluoto, Finland. Soil profiles from Dovrefjell exhibited an approximately exponential fall in 210 Pb activity concentrations from elevated levels in humus/surface soils to 'supported' levels at depth. Activity concentrations of 210 Po in fauna (invertebrates, mammals, birds) ranged between 2 and 123 Bq kg -1 d.w. and in plants and lichens between 20 and 138 Bq kg -1 d.w. The results showed that soil humus is an important reservoir for 210 Po and 210 Pb and that fauna in close contact with this media may also exhibit elevated levels of 210 Po. Concentration ratios appear to have limited applicability with regards to prediction of activity concentrations of 210 Po in invertebrates and vertebrates. Biokinetic models may provide a tool to explore in a more mechanistic way the behaviour of 210 Po in this system.

  4. Levels of {sup 210} Pb and {sup 210} Po in Brazilian cigarettes

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Pedro Lopes dos; Kelecom, Alphonse; Gouvea, Rita de Cassia dos Santos; Dutra, Iedo Ramos [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Biologia Geral

    1996-12-01

    {sup 210} Po and {sup 210} Pb concentrations have been determined in 18 Brazilian cigarette samples and compared with known data on U content. U is respectively 3-fold less and 4-fold less abundant than {sup 210} Po or {sup 210} Pb. No correlation could be observed between U concentration and those of Po or Pb. The mean concentration of {sup 210} Pb is higher than that of {sup 210} Pb observed in many other plants, even in plants frown in high background areas. (author) 19 refs., 1 fig., 1 tab.

  5. Volatility of 210Po in airborne dusts in an atmosphere of nitrogen

    International Nuclear Information System (INIS)

    Abe, Michiko; Abe, Siro; Ikeda, Nagao.

    1976-01-01

    Volatilization behavior of 210 Po contained in airborne dusts in the temperature range of 200 - 800 0 C was investigated in an atmosphere of nitrogen. It was revealed that the volatilization of 210 Po in airborne dusts in an atmosphere of nitrogen as a function of temperature can be expressed in a stairlike shape with two steps. This tendency is similar to the previous results obtained in air. The previous and present data may suggest that 210 Po in airborne dusts consists of two or more different kinds of chemical species. (auth.)

  6. High efficient multifunctional Ag{sub 3}PO{sub 4} loaded hydroxyapatite nanowires for water treatment

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yaling; Zhou, Hangyu; Zhu, Genxing [Center for Biomaterials and Biopathways, Department of Chemistry, Zhejiang University, Hangzhou (China); Shao, Changyu; Pan, Haihua; Xu, Xurong [Center for Biomaterials and Biopathways, Department of Chemistry, Zhejiang University, Hangzhou (China); Qiushi Academy for Advanced Studies, Zhejiang University (China); Tang, Ruikang, E-mail: rtang@zju.edu.cn [Center for Biomaterials and Biopathways, Department of Chemistry, Zhejiang University, Hangzhou (China); Qiushi Academy for Advanced Studies, Zhejiang University (China)

    2015-12-15

    Highlights: • The multifunctional Ag{sub 3}PO{sub 4} loaded hydroxyapatite (HAP) nanowires were synthesized via a facile in-situ precipitation method. • By optimizing the initial concentration of AgNO{sub 3}, the well-distributed Ag{sub 3}PO{sub 4}/HAP composites could be achieved. • The Ag{sub 3}PO{sub 4}/HAP composites showed excellent photocatalytic performance for the decomposition of dyes under visible light irradiation. • The maximum absorption capacity of the Ag{sub 3}PO{sub 4}/HAP composites for Pb(II) was 250 mg/g, approximately three times as that of pure HAP. • The Ag{sub 3}PO{sub 4}/HAP composites also exhibited excellent antibacterial activities even at relative low concentrations. - Abstract: Organic, inorganic, and biological pollutants are typical water contaminants and they seriously affect water quality. In this study, we suggested that a novel multifunctional Ag{sub 3}PO{sub 4} loaded hydroxyapatite (HAP) material can remove the typical pollutants from water. The Ag{sub 3}PO{sub 4}/HAP composites were synthesized facilely via in-situ precipitation of Ag{sub 3}PO{sub 4} on the pre-existing HAP nanowires. By optimizing the composition of Ag{sub 3}PO{sub 4} and HAP, the material could achieve an optimal photocatalytic activity to decompose rhodamine B (RhB), methyl orange (MO) and methylene blue (MB) under visible light irradiations with enhanced pH stability. Besides, the adsorption of Pb(II) on the Ag{sub 3}PO{sub 4}/HAP reached a maximum capacity of 250 mg/g and this value was approximately three times as that of pure HAP. Furthermore, the composite material exhibited excellent antibacterial activities towards gram-negative bacterium (Escherichia coli) and gram-positive bacterium (Stphylococcus aureus). The results highlighted the cooperative effect between Ag{sub 3}PO{sub 4} and hydroxyapatite (HAP). The simultaneous removals of dyes, toxic metal ions, and bacteria with a high efficiency followed an easy approach for the purification

  7. Acid indium strontium phosphate SrIn2[PO3(OH)]4: synthesis and crystal structure

    International Nuclear Information System (INIS)

    Rusakov, D.A.; Bobylev, A.P.; Komissarova, L.N.; Filaretov, A.A.; Danilov, V.P.

    2007-01-01

    Acid indium-strontium phosphate SrIn 2 [PO 3 (OH)] 4 is synthesized and characterized. Crystal structure and lattice parameters ate determined. In atoms in SrIn 2 [PO 3 (OH)] 4 structure are in distorted InO 6 octahedrons and form with PO 3 (OH) tetrahedrons mixed paraskeleton {In 2 [PO 3 (OH)] 4 } 3∞ 2- with emptinesses occupied by big Sr 2+ cations. The compound is thermally stable up to 400 Deg C [ru

  8. Phase equilibria in the NaF-CdO-NaPO{sub 3} system at 873 K and crystal structure and physico-chemical characterizations of the new Na{sub 2}CdPO{sub 4}F fluorophosphate

    Energy Technology Data Exchange (ETDEWEB)

    Aboussatar, Mohamed [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Laboratoire de Physico-Chimie de l’État Solide, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax (Tunisia); Mbarek, Aïcha [Laboratoire de Chimie Industrielle, Ecole Nationale d’Ingénieurs de Sfax, Université de Sfax, BP W3038, 3000 Sfax (Tunisia); Naili, Houcine [Laboratoire de Physico-Chimie de l’État Solide, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax (Tunisia); El-Ghozzi, Malika [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Chadeyron, Geneviève [Université Clermont Auvergne, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS/UBP/SIGMA, BP 10448, F-63000 Clermont-Ferrand (France); Avignant, Daniel [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Zambon, Daniel, E-mail: Daniel.Zambon@univ-bpclermont.fr [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France)

    2017-04-15

    Isothermal sections of the diagram representing phase relationships in the NaF-CdO-NaPO{sub 3} system have been investigated by solid state reactions and powder X-ray diffraction. This phase diagram investigation confirms the polymorphism of the NaCdPO{sub 4} side component and the structure of the ß high temperature polymorph (orthorhombic, space group Pnma and unit cell parameters a=9.3118(2), b=7.0459(1), c=5.1849(1) Å has been refined. A new fluorophosphate, Na{sub 2}CdPO{sub 4}F, has been discovered and its crystal structure determined and refined from powder X-ray diffraction data. It exhibits a new 3D structure with orthorhombic symmetry, space group Pnma and unit cell parameters a=5.3731(1), b=6.8530(1), c=12.2691(2) Å. The structure is closely related to those of the high temperature polymorph of the nacaphite Na{sub 2}CaPO{sub 4}F and the fluorosilicate Ca{sub 2}NaSiO{sub 4}F but differs essentially in the cationic repartition since the structure is fully ordered with one Na site (8d) and one Cd site (4c). Relationships with other Na{sub 2}M{sup II}PO{sub 4}F (M{sup II}=Mg, Ca, Mn, Fe, Co, Ni) have been examined and the crystal-chemical and topographical analysis of these fluorophosphates is briefly reviewed. IR, Raman, optical and {sup 19}F, {sup 23}Na, {sup 31}P MAS NMR characterizations of Na{sub 2}CdPO{sub 4}F have been investigated. - Graphical abstract: The structure of the compound Na{sub 2}CdPO{sub 4}F, discovered during the study of the phase relationships in the NaF-CdO-NaPO{sub 3} system, has been determined and compared with other Na{sub 2}M{sup II}PO{sub 4}F fluorophosphates. - Highlights: • XRD analysis of the isothermal section of the NaF-CdO-NaPO{sub 3} system at 923 K. • Rietveld refinement of the high temperature polymorph β-NaCdPO{sub 4}. • Crystal structure of the new Na{sub 2}CdPO{sub 4}F fluorophosphate determined from powder XRD. • Crystal structure - composition relationships of Na{sub 2}M{sup II}PO{sub 4}F compounds

  9. Assessment of 210Po deposition in moss species and soil around coal-fired power plant

    International Nuclear Information System (INIS)

    Nita Salina Abu Bakar; Ahmad Saat

    2013-01-01

    In the present study, the depositions of 210 Po were assessed in the surface soil and some mosses species found in the area around coal fired power plant using radiochemical deposition and alpha spectrometry counting system. The purposes of the study were to determine activity concentrations of 210 Po in mosses and surface soil collected around coal-fired power plant in relation to trace the potential source of 210 Po and to identify most suitable moss species as a bio-indicator for 210 Po deposition. In this study, different species of mosses, Orthodontium imfractum, Campylopus serratus and Leucobryum aduncum were collected in May 2011 at the area around 15 km radius from Tanjung Bin coal-fired power plant located in Pontian, Johor. The 210 Po activity concentrations in mosses and soil varied in the range 102 ± 4 to 174 ± 8 Bq/kg dry wt. and 37 ± 2 to 184 ± 8 Bq/kg dry wt., respectively. Corresponding highest activity concentration of 210 Po observed in L. aduncum, therefore, this finding can be concluded this species was the most suitable as a bio-indicator for 210 Po deposition. On the other hand, it is clear the accumulation of 210 Po in mosses might be supplied from various sources of atmospheric deposition such as coal-fired power plant operation, industrial, plantation, agriculture and fertilizer activities, burned fuel fossil and forest; and other potential sources. Meanwhile, the main source of 210 Po in surface soil is supplied from the in situ deposition of radon decay and its daughters in the soil itself. (author)

  10. Voyage: espace et poésie dans un calligramme d'Apollinaire

    Directory of Open Access Journals (Sweden)

    Laurent GRISON

    1998-06-01

    Full Text Available L'œuvre de Guillaume Apollinaire offre une approche spécifique de la poésie et de l'espace. L'étude d'un calligramme, Voyage, nous permet de souligner à quel point cet auteur mêle travail poétique et réflexion sur la spatialité.

  11. Phase evolution and photoluminescence enhancement of CePO4 nanowires from a low phosphate concentration system

    International Nuclear Information System (INIS)

    Xu Pengfei; Yu Ranbo; Zong Lingbo; Wang Jiali; Wang Dan; Deng Jinxia; Chen Jun; Xing Xianran

    2013-01-01

    Uniform CePO 4 nanowires have been successfully synthesized in a low phosphate concentration system through a single-step hydrothermal process. The low phosphate concentration might decrease the surface PO 4 3− adsorption of the as-synthesized CePO 4 nanowires efficiently and benefit their photoluminescence. The CePO 4 nanowires were identified to go through phase evolution from pure monoclinic to mixed hexagonal and monoclinic phase by only increasing the initial molar ratio of cerium and phosphate source (denoted as Ce/P). Interestingly, the strongest photoluminescence was observed in the CePO 4 nanowires synthesized with the initial Ce/P of 4:1, which proved to be the critical phase evolution point between the hexagonal and monoclinic CePO 4 . Therefore, the strong photoluminescence could be explained by the existence of the structure-sensitive energy level in the CePO 4 . This kind of photoluminescence enhancement would be a meaningful reference for design of other photoluminescent materials, in which the photoluminescent emission might be related to the structure-sensitive energy level. Additionally, the growth processes of CePO 4 nanowires based on related well-designed experiments were proposed.

  12. Effects of neodymium aliovalent substitution on the structure and electrochemical performance of LiFePO4

    International Nuclear Information System (INIS)

    Zhao Xian; Tang Xiaozhen; Zhang Li; Zhao Minshou; Zhai Jing

    2010-01-01

    LiFe 1-x Nd x PO 4 /C (x = 0-0.08) cathode material was synthesized using a solid-state reaction. The synthesis conditions were optimized by thermal analysis of the precursor and magnetic properties of LiFePO 4 /C. The structure and electrochemical performances of the material were studied using XRD, FE-SEM, EDS, electrochemical impedance spectroscopy and galvanostatic charge-discharge. The results show that a small amount of aliovalent Nd 3+ ion-dopant substitution on Fe 2+ ions can effectively reduce the particle size of LiFePO 4 /C. Cell parameters of LiFe 1-x Nd x PO 4 (x = 0.04-0.08) were calculated, and the results showed that LiFe 1-x Nd x PO 4 /C had the same olivine structure as LiFePO 4 . LiFe 0.4 Nd 0.6 PO 4 /C delivers the discharge capacity of 165.2 mAh g -1 at rate of 0.2 C and the capacity retention rate is 92.8% after 100 cycles. Charge-transfer resistance decreases with the addition of glucose and Nd 3+ ions. Poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol) (PZS) was synthesized and PZS nanorods were used as a carbon source to coat LiFePO 4 . All of the results show that aliovalent doping substitution of Fe in LiFePO 4 is well tolerated.

  13. Is ecological food also radioecological? - 210Po and 210Pb studies.

    Science.gov (United States)

    Strumińska-Parulska, Dagmara; Olszewski, Grzegorz

    2018-01-01

    Presented are results of a study on accumulation of naturally occurring 210 Po and 210 Pb in ecological and conventional farming food products in Poland: fruits, vegetables and cereals. The main idea behind this research was to determine the activity concentrations of 210 Po and 210 Pb in ecological and commercial food as well as calculate and compare the effective dose (radiation) connected to different origin of analyzed food products consumption. The studies showed the majority of all compared food samples contained similar 210 Po and 210 Pb activities and statistically, the consumption of organic and commercial food would give similar annual effective dose. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Variation of 210Po and 210Pb Profile in the Sediment Core of Sarawak Coastal Waters

    International Nuclear Information System (INIS)

    Zal U'yun Wan Mahmood; Che Abd Rahim Mohamed; Zaharudin Ahmad; Abdul Kadir Ishak

    2008-01-01

    This study was performed to observe the variation in the distribution of 210 Po and 210 Pb through their activity vertical profile and 210 Po/ 210 Pb activity ratio in the sediment cores that were taken at some sampling stations in the Sarawak coastal waters. It was found that the distribution profile of those radionuclide in the sediment cores varied depending on the sampling location and ANOVA analysis shows significant difference at 95% confidence level for activities of 210 Po (p = 0.000), 210 Pb (p = 0.035) and 210 Po/ 210 Pb (p = 0.000) at all study locations. Generally, the measured activity of 210 Po and 210 Pb ranged from 337 to 2460 Bq/ kg, 11 to 84 Bq/ kg at SR 01; 224 to 2008 Bq/ kg, 6 to 80 Bq/ kg at SR 02; 119 to 1595 Bq/ kg, 6 to 84 Bq/ kg at SR 03; 241 to 2294 Bq/ kg, 5 to 82 Bq/ kg at SR 04 and 175 to 1340 Bq/ kg, 4 to 44 Bq/ kg at SR 05, respectively. In those range it was found that 210 Po activities were higher than 210 Pb with average of 210 Po/ 210 Pb ratios at all stations were from 20 to 35. The variation in the distribution profile for the radionuclides are believed to be influenced by some environmental factors and have strong correlation between the radionuclide distribution and the sediment composition of silt ( 210 Po: r = 0.701 and 210 Pb: r = 0.648), water depth ( 210 Po: r = -0.647) and the distance from the sampling station to the main land ( 210 Po: r = 0.746 and 210 Pb: r = 0.975). Those factors are a major contributions on the variation of 210 Po and 210 Pb in the samples. (author)

  15. Distribution of Po-210 in two species of predatory marine fish from the Brazilian coast

    International Nuclear Information System (INIS)

    Mársico, E.T.; Ferreira, M.S.; São Clemente, S.C.; Gouvea, R.C.S.; Jesus, E.F.O.; Conti, C.C.; Conte Junior, C.A.; Kelecom, A.G.A.C.

    2014-01-01

    Polonium-210 ( 210 Po) concentration was quantified in the muscle tissue and organs of two predatory marine fishes (Genypterus brasiliensis and Cynoscion microlepidotus) from Cabo Frio, Rio de Janeiro, Brazil. The species C. microlepidotus, a benthic carnivore, registered higher 210 Po in its tissue. The organs associated with digestion displayed the maximum radionuclide compared with other organs. The average activity was 2 mBq kg −1 for G. brasiliensis and it was 6 mBq kg −1 for C. microlepidotus. The activity concentrations varied significantly between the species and among organs. -- Highlights: • We analyzed the distribution of 210 Po in two species of predator marine fish. • 210 Po tends to accumulate in some organs, which make this radionuclide radiotoxic. • The consumption of small quantities of fish can represent high potential of 210 Po exposure. • Data about 210 Po bioaccumulation in tropical predator marine fish are limited

  16. Po-210 and Pb-210 in water and fish from Taboshar uranium mining Pit Lake, Tajikistan

    International Nuclear Information System (INIS)

    Skipperud, L.; Jørgensen, A.G.; Heier, L.S.; Salbu, B.; Rosseland, B.O.

    2013-01-01

    Polonium-210 in water and 210 Pb and 210 Po in different fish organs from 3 different fish species in Taboshar Pit Lake (n = 13), located in the uranium mining area in Tajikistan, and in Kairakkum Reservoir (reference lake, n = 3), have been determined as part of a Joint project between Norway, Kazakhstan, Kyrgyzstan and Tajikistan. The average activity concentration of 210 Pb and 210 Po in liver, muscle and bone of Carassius auratus was higher than the concentration in similar tissues of C. carpio and Sander lucioperca from the reference site. The accumulation of 210 Po was higher than for 210 Pb, and the accumulation of 210 Po was highest in the liver of C. auratus (3673 ± 434 Bq kg −1 ww). Although the average activity concentration of 210 Pb in liver and bones of C. auratus from Pit Lake were fairly similar, a huge variation in the liver activity concentrations (25–327 Bq kg −1 ww) was found. The results confirm direct uptake of unsupported 210 Po into the liver, and that the distributions of 210 Po and 210 Pb in fish organs were different. The BCF (L/kg) for 210 Po in bone, liver and muscle clearly demonstrates high accumulation of 210 Po in C. auratus, especially in the liver. The average BCFs of liver, bone and muscle were >1.4 × 10 5 , >2.5 × 10 4 and >1.4 × 10 4 , respectively. All fish in the Pit Lake were found to be in the same trophic level, however, a linear correlation between log 210 Po in liver and δ 15 N could indicate biomagnification of 210 Po in liver of C. auratus. In regards to the recommended Annual Limit of Intake (ALI) for 210 Po, the concentration of 210 Po in muscle tissues of C. auratus is alarming, as there is a high probability for the local population at risk to exceed the recommended ALI through consumption of fish from Taboshar Pit Lake

  17. [sup 57]Fe Moessbauer spectroscopic studies of the ferrocene molecular reorientation in AlPO[sub 4]-5 and AlPO[sub 4]-8 frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Lund, A.; Nicholson, D.G. (Department of Chemistry, University of Trondheim, Dragvoll (Norway)); Parish, R.V.; Wright, J.P. (Department of Chemistry, UMIST, Manchester (United Kingdom))

    1994-01-01

    [sup 57]Fe Moessbauer spectroscopic studies were carried out on ferrocene guest molecules in some microporous aluminium phosphate host lattices in order to investigate their behaviour in the aluminium phosphate channels. The 300 K spectra show broad single lines with isomer shifts of 0.39 and 0.41 mm s[sup -1] relative to iron for AlPO[sub 4]-5:ferrocene and AlPO[sub 4]-8:ferrocene inclusion compounds, respectively. The absence of quadrupole splittings for these materials contrasts with the large quadrupole splitting observed for ferrocene itself at the same temperature. The low-temperature spectrum (20 K) for AlPO[sub 4]-5:ferrocene shows a doublet with quadrupole splitting of 2.37 mm s[sup -1] and an isomer shift of 0.55 mm s[sup -1]. The collapse of the quadrupole splitting at room temperature is consistent with the ferrocene molecules rotating within the channels. (au).

  18. Spontaneous Fluctuations of PO2 in the Rabbit Somatosensory Cortex.

    Science.gov (United States)

    Linsenmeier, Robert A; Aksenov, Daniil P; Faber, Holden M; Makar, Peter; Wyrwicz, Alice M

    2016-01-01

    In many tissues, PO2 fluctuates spontaneously with amplitudes of a few mmHg. Here we further characterized these oscillations. PO2 recordings were made from the whisker barrel cortex of six rabbits with acutely or chronically placed polarographic electrodes. Measurements were made while rabbits were awake and while anesthetized with isoflurane, during air breathing, and during 100% oxygen inspiration. In awake rabbits, 90% of the power was between 0 and 20 cycles per minute (cpm), not uniformly distributed over this range, but with a peak frequently near 10 cpm. This was much slower than heart or respiratory rhythms and is similar to the frequency content observed in other tissues. During hyperoxia, total power was higher than during air-breathing, and the dominant frequencies tended to shift toward lower values (0-10 cpm). These observations suggest that at least the lower frequency fluctuations represent efforts by the circulation to regulate local PO2. There were no consistent changes in total power during 0.5 or 1.5% isoflurane anesthesia, but the power shifted to lower frequencies. Thus, both hyperoxia and anesthesia cause characteristic, but distinct, changes in spontaneous fluctuations. These PO2 fluctuations may be caused by vasomotion, but other factors cannot be ruled out.

  19. Continuous arterial PO2 profiles in unrestrained, undisturbed aquatic turtles during routine behaviors

    Science.gov (United States)

    Hicks, James W.

    2016-01-01

    ABSTRACT Mammals and birds maintain high arterial partial pressure of oxygen (PO2) values in order to preserve near-complete hemoglobin (Hb) oxygen (O2) saturation. In diving mammals and birds, arterial O2 follows a primarily monotonic decline and then recovers quickly after dives. In laboratory studies of submerged freshwater turtles, arterial O2 depletion typically follows a similar pattern. However, in these studies, turtles were disturbed, frequently tethered to external equipment and confined either to small tanks or breathing holes. Aquatic turtles can alter cardiac shunting patterns, which will affect arterial PO2 values. Consequently, little is known about arterial O2 regulation and use in undisturbed turtles. We conducted the first study to continuously measure arterial PO2 using implanted microelectrodes and a backpack logger in undisturbed red-eared sliders during routine activities. Arterial PO2 profiles during submergences varied dramatically, with no consistent patterns. Arterial PO2 was also lower than previously reported during all activities, with values rarely above 50 mmHg (85% Hb saturation). There was no difference in mean PO2 between five different activities: submerged resting, swimming, basking, resting at the surface and when a person was present. These results suggest significant cardiac shunting occurs during routine activities as well as submergences. However, the lack of relationship between PO2 and any activity suggests that cardiac shunts are not regulated to maintain high arterial PO2 values. These data support the idea that cardiac shunting is the passive by-product of regulation of vascular resistances by the autonomic nervous system. PMID:27618860

  20. Los 'Horizontes poéticos' (1881) de Francisca Sarasate

    OpenAIRE

    Mata-Induráin, C. (Carlos)

    1999-01-01

    Francisca Sarasate supone una excepción notable en el área de las letras navarras, por la escasez de mujeres en el ámbito literario. Cultivó, entre otros, la novela, el cuento, el teatro y la poesía. Destaca su obra 'Horizontes poéticos'. ------------------ Francisca Sarasate is a notable exception in the area of the letters of Navarra, by the scarcity of women in the literary field. She cultivated the novel, short stories, drama and poetry. She wrote, among others, 'Horizontes poéticos'....

  1. Additional radiation exposure of the smoker from Pb-210 and Po-210

    International Nuclear Information System (INIS)

    Gloebel, B.

    1985-01-01

    The content in Pb-210 and Po-210 was measured in 100 packs of cigarettes. Both nuclides exist in a radioactive equilibrium. 4 mBq per cigarette were measured on average. With artificially smoked cigarettes 50% of the Pb and 85% of Po are detectable in the smoke. Smoking, therefore, leads to an increased radiation exposure, in particular of the lungs. Owing to a metabolic behaviour the increased radiation exposure of the lungs is caused by Po. Smoking 30 cigarettes a day will lead to an additional load on the lungs of about 20 mrad/a. (orig.) [de

  2. Connected Lighting Systems Efficiency Study$-$ PoE Cable Energy Losses, Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Tuenge, Jason [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kelly, Karsten [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Poplawski, Michael [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-11-30

    First report in a study of the efficiency of connected lighting systems. The report summarizes the results of an exploratory study investigating power losses in Ethernet cables used between PoE switches and luminaires in PoE connected lighting systems. Testing was conducted at the Pacific Northwest National Laboratory (PNNL) Connected Lighting Test Bed in September 2017. The results were analyzed to explore the impact of cable selection on PoE lighting system energy efficiency, as well as the effectiveness of guidelines recently introduced by the American National Standards Institute (ANSI) C137 Lighting Systems Committee.

  3. Determination of 210Pb e 210Po in marine samples and aerosols

    International Nuclear Information System (INIS)

    Saito, Roberto Tatsuya

    1996-01-01

    In this work the methodologies for 210 Pb e 210 Po analyses in marine samples, such as fish, seaweed, sediment, and aerosol samples are presented. The 210 Pb levels in the samples were obtained by both 210 Bi and 210 Po ingrowth. The 210 Pb analysis via 210 Bi presents the following steps: 210 Pb leaching from samples with 8 M nitric acid and hydrogen peroxide; lead sulphate precipitation; conversion to carbonate; dissolution; lead sulphate precipitation; gravimetric analysis of lead; waiting of time to reach radioactive equilibrium and 210 Bi beta counting by employing a Geiger-Mueller detector with a low background radiation. The 210 Pb analysis via 210 Po presents the following steps: 210 Pb and 210 Po leaching from samples with 8 M nitric acid and hydrogen peroxide; nitric acid elimination by heating and hydrochloric acid addition; spontaneous deposition onto silver disc and alpha counting of polonium in silicon surface-barrier detector. In order to determine 210 Pb activity, the solution was percolated in the Dowex AG 1-X 8 anion exchange resin; preconditioned with 8 M nitric acid; the lead was eluted by 8 M hydrochloric acid; the solution was gently evaporated to dryness and diluted with 0.5 N hydrochloric acid. After 3-6 months a second 210 Po spontaneous deposition onto silver disc was carried out. The methodology for 210 Pb analysis via 210 Bi showed lead recoveries from 63 to 100%. In the method via 210 Po the polonium recoveries were varied from 39 to 63% under manual agitation, and from 60 to 100% under mechanical agitation. The radiochemical methods for 210 Po and 210 Pb analyses were applied in reference samples from International Atomic Energy Agency (IAEA) and the results obtained showed the good precision and accuracy of the established methods. The analysis of marine sediment samples of Antarctica presented 210 Pb and Po levels from 8 to 60 Bq.kg -1 , and fish samples from Sao Paulo Coast presented 210 Po levels from 0.5 to 5.3 Bq.kg -1 . These

  4. Optical Properties and Electrochemical Performance of LiFePO4 Thin Films Deposited on Transparent Current Collectors.

    Science.gov (United States)

    Lee, HyunSeok; Yim, Haena; Kim, Kwang-Bum; Choi, Ji-Won

    2015-11-01

    LiFePO4 thin film cathodes are deposited on various transparent conducting oxide thin films on glass, which are used as cathode current collectors. The XRD patterns show that the thin films have the phase of LiFePO4 with an ordered olivine structure indexed to the orthorhombic Pmna space group. LiFePO4 thin film deposited on various TCO glass substrates exhibits transmittance of about 53%. The initial specific discharge capacities of LiFePO4 thin films are 25.0 μAh/cm2 x μm on FTO, 33.0 μAh/cm2 x μm on ITO, and 13.0 μAh/cm2 x μm on AZO coated glass substrates. Interestingly, the retention capacities of LiFePO4 thin films are 76.0% on FTO, 31.2% on ITO, and 37.7% on AZO coated glass substrates at 20th cycle. The initial specific discharge capacity of the LiFePO4/FTO electrode is slightly lower, but the discharge capacities of the LiFePO4/FTO electrode relatively decrease less than those of the others such as LiFePO4/ITO and LiFePO4/AZO with cycling. The results reported here provide the high transparency of LiFePO4 thin films cathode materials and the good candidate as FTO current collector of the LiFePO4 thin film cathode of transparent thin film rechargeable batteries due to its high transparency and cyclic retention.

  5. poCAMon personal online continuous airmonitor

    International Nuclear Information System (INIS)

    Streil, T.; Oeser, V.

    2015-01-01

    The poCAMon combines a very compact design with a high flow rate and long battery life. Its size and weight are still acceptable for carrying by one person. The unit measures long-lived aerosols as well as short-lived Radon/Thoron daughters by alpha spectroscopy and beta counting. The radioactive aerosols and particles are collected on the surface of a high resolution membrane filter. The alpha and beta decays on the filter are measured by a high-end semiconductor radiation detector (400 mm@). This allows a perfect separation of the different decay products. The increased pump rate (more than 3 l/ min) is suitable for lower detection limits. A sensor measures permanently the pressure drop on the filter in order to recognize an exhausted or perforated filter instantly. With the 3.8 Ah NiMH battery pack the poCAMon achieves an operation time of more than 30 hours. The quality control is a main issue of any radiation measurement. Therefore the poCAMon records a complete alpha spectrum for each measured value. This allows the monitoring of the device's perfect operation in each moment of the measurement. There are options for additional sensors for carbon monoxide and combustible gases as needed in underground mines. All measured data are stored in a 2GB memory card and can be accessed with a PC or laptop via a USB interface. Data transmission and device control can also be done via wireless ZigBee network or via a server for stationary operation with network access. A barometric pressure sensor and a GPS receiver are optional features of the device.

  6. Content of 210Pb and 210Po in main foods of Hunan province

    International Nuclear Information System (INIS)

    Yan Jiaquan

    1992-01-01

    Investigation results were reported of content of 210 Pb and 210 Po in main foods of Hunan province from 1988 to early 1989. The content of 210 Pb and 210 Po in 17 kinds of foods investigated ranges from 0.02 to 11.8 Bqkg -1 and from 0.04 to 15.6 Bqkg -1 respectively. The estimated committed dose equivalents of residents were 102.6 μSv and 29.6 μSv for 210 Pb and 210 Po taken through foods respectively

  7. 210Po in the marine environment with emphasis on its behaviour within the biosphere.

    Science.gov (United States)

    Fowler, Scott W

    2011-05-01

    The distribution and behaviour of the natural-series alpha-emitter polonium-210 in the marine environment has been under study for many years primarily due to its enhanced bioaccumulation, its strong affinity for binding with certain internal tissues, and its importance as a contributor to the natural radiation dose received by marine biota as well as humans consuming seafoods. Results from studies spanning nearly 5 decades show that (210)Po concentrations in organisms vary widely among the different phylogenic groups as well as between the different tissues of a given species. Such variation results in (210)Po concentration factors ranging from approximately 10(3) to over 10(6) depending upon the organism or tissue considered. (210)Po/(210)Pb ratios in marine species are generally greater than unity and tend to increase up the food chain indicating that (210)Po is preferentially taken up by organisms compared to its progenitor (210)Pb. The effective transfer of (210)Po up the food chain is primarily due to the high degree of assimilation of the radionuclide from ingested food and its subsequent strong retention in the organisms. In some cases this mechanism may lead to an apparent biomagnification of (210)Po at the higher trophic level. Various pelagic species release (210)Po and (210)Pb packaged in organic biodetrital particles that sink and remove these radionuclides from the upper water column, a biogeochemical process which, coupled with scavenging rates of this radionuclide pair, is being examined as a possible proxy for estimating downward organic carbon fluxes in the sea. Data related to preferential bioaccumulation in various organisms, their tissues, resultant radiation doses to these species, and the processes by which (210)Po is transferred and recycled through the food web are discussed. In addition, the main gaps in our present knowledge and proposed areas for future studies on the biogeochemical behaviour of (210)Po and its use as a tracer of

  8. 210Po in the marine environment with emphasis on its behaviour within the biosphere

    International Nuclear Information System (INIS)

    Fowler, Scott W.

    2011-01-01

    The distribution and behaviour of the natural-series alpha-emitter polonium-210 in the marine environment has been under study for many years primarily due to its enhanced bioaccumulation, its strong affinity for binding with certain internal tissues, and its importance as a contributor to the natural radiation dose received by marine biota as well as humans consuming seafoods. Results from studies spanning nearly 5 decades show that 210 Po concentrations in organisms vary widely among the different phylogenic groups as well as between the different tissues of a given species. Such variation results in 210 Po concentration factors ranging from approximately 10 3 to over 10 6 depending upon the organism or tissue considered. 210 Po/ 210 Pb ratios in marine species are generally greater than unity and tend to increase up the food chain indicating that 210 Po is preferentially taken up by organisms compared to its progenitor 210 Pb. The effective transfer of 210 Po up the food chain is primarily due to the high degree of assimilation of the radionuclide from ingested food and its subsequent strong retention in the organisms. In some cases this mechanism may lead to an apparent biomagnification of 210 Po at the higher trophic level. Various pelagic species release 210 Po and 210 Pb packaged in organic biodetrital particles that sink and remove these radionuclides from the upper water column, a biogeochemical process which, coupled with scavenging rates of this radionuclide pair, is being examined as a possible proxy for estimating downward organic carbon fluxes in the sea. Data related to preferential bioaccumulation in various organisms, their tissues, resultant radiation doses to these species, and the processes by which 210 Po is transferred and recycled through the food web are discussed. In addition, the main gaps in our present knowledge and proposed areas for future studies on the biogeochemical behaviour of 210 Po and its use as a tracer of oceanographic

  9. Improvement of the mechanical properties and corrosion resistance of biodegradable β-Ca3(PO4)2/Mg-Zn composites prepared by powder metallurgy: the adding β-Ca3(PO4)2, hot extrusion and aging treatment.

    Science.gov (United States)

    Yan, Yang; Kang, Yijun; Li, Ding; Yu, Kun; Xiao, Tao; Deng, Youwen; Dai, Han; Dai, Yilong; Xiong, Hanqing; Fang, Hongjie

    2017-05-01

    In this study, 10%β-Ca 3 (PO 4 ) 2 /Mg-6%Zn (wt.%) composites with Mg-6%Zn alloy as control were prepared by powder metallurgy. After hot extrusion, the as-extruded composites were aged for 72h at 150°C. The effects of the adding β-Ca 3 (PO 4 ) 2 , hot extrusion and aging treatment on their microstructure, mechanical properties and corrosion resistance were investigated. The XRD results identified α-Mg, MgZn phase and β-Ca 3 (PO 4 ) 2 phase in these composites. After hot extrusion, grains were significantly refined, and the larger-sized β-Ca 3 (PO 4 ) 2 particles and coarse MgZn phases were broken into linear-distributed β-Ca 3 (PO 4 ) 2 and MgZn phases along the extrusion direction. After aging treatment, the elements of Zn, Ca, P and O presented a more homogeneous distribution. The compressive strengths of the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites were approximately double those of natural bone, and their densities and elastic moduli matched those of natural bone. The immersion tests and electrochemical tests revealed that the adding β-Ca 3 (PO 4 ) 2 , hot extrusion and aging treatment could promote the formation of protective corrosion product layer on the sample surface in Ringer's solution, which improved corrosion resistance of the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites. The XRD results indicated that the corrosion product layer contained Mg(OH) 2 , β-Ca 3 (PO 4 ) 2 and hydroxyapatite (HA). The cytotoxicity assessments showed the as-extruded β-Ca 3 (PO 4 ) 2 /Mg-Zn composite aged for 72h was harmless to L-929 cells. These results suggested that the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites prepared by powder metallurgy were promising to be used for bone tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Ratio of 210Po and 210Pb in fresh, brackish and saline water in Kuala Selangor river

    International Nuclear Information System (INIS)

    Tan Chin Siang; Che Abdul Rahim Mohamed; Zaharuddin Ahmad

    2007-01-01

    Sediment cores were carried out from Kuala Selangor river to amine sea water via coastal and brackish water ambient. Sample size fraction with size less than 125 μm was spiked with tracer 209 Po and leached with mix concentrated nitric acid, perchloric acid, hydrogen peroxide, hydrochloric acid and mineralized with 50 ml of 0.5M HCl. The sample solution was used for spontaneously deposit polonium on a silver disk at 80-85 degree Celsius and measured with the Alpha Spectrometry. The distribution of two radionuclides especially 210 Po, 210 Pb and 210 po/ 210 Pb were useful in identifying the origin of 210 Po. Ratio values of 210 Po/ 210 Pb in the freshwater, brackish water and saline water were 3.3459, 5.8385 and 2.9831, respectively. From the high ratio of 210 Po/ 210 Pb, the widespread occurrence of excess 210 Po in Kuala Selangor river water may came from the atmosphere sources such as stratospheric aerosols, sea spray of the surface micro layer and bio-volatile 210 Po organism from productive species. (author)

  11. Supercapacitors studies on BiPO4 nanoparticles synthesized via a simple microwave approach

    Directory of Open Access Journals (Sweden)

    S. Vadivel

    2017-07-01

    Full Text Available BiPO4 nanomaterial was synthesized using EDTA (ethylene diamine tetra acetic acid as the surfactant via a simple microwave method. The structure and morphology of BiPO4 were systematically characterized by X-ray diffraction (XRD, Fourier-transform infrared spectroscopy (FT-IR, and scanning electron microscopy (FE-SEM studies. The obtained BiPO4 nanoparticles were, on average, 150–300 nm. The electrochemical results showed that the specific capacitance of BiPO4 obtained using the microwave route was up to 104 Fg−1 at a current density of 1 Ag−1 with a large potential window of 1.7 V. The material showed excellent cycling stability (92% capacitance retention after 500 cycles at a current density of 1 Ag−1.

  12. Ultrasound guided pO2 measurement of breast cancer reoxygenation after neoadjuvant chemotherapy and hyperthermia treatment.

    Science.gov (United States)

    Vujaskovic, Z; Rosen, E L; Blackwell, K L; Jones, E L; Brizel, D M; Prosnitz, L R; Samulski, T V; Dewhirst, M W

    2003-01-01

    The objective of this study was to determine whether neoadjuvant chemotherapy in combination with hyperthermia (HT) would improve oxygenation in locally advanced breast tumours. The study describes a new optimized ultrasound guided technique of pO2 measurement using Eppendorf polarographic oxygen probes in 18 stage IIB-III breast cancer patients. Prior to treatment, tumour hypoxia (median pO2pO2=3.2 mmHg). Seven patients had well oxygenated tumours (median pO2 of 48.3 mmHg). Eight patients with hypoxic tumours prior to treatment had a significant improvement (p=0.0008) in tumour pO2 after treatment (pO2 increased to 19.2 mmHg). In three patients, tumours remained hypoxic (average median pO2=4.5 mmHg). The advantages of the ultrasound guided pO2 probe are in the accuracy of the Eppendorf electrode placement in tumour tissue, the ability to monitor electrode movement through the tumour tissue during the measurement and the ability to avoid electrode placement near or in large blood vessels by using colour Doppler imaging. The results of this preliminary study suggest that the combination of neoadjuvant chemotherapy and hyperthermia improves oxygenation in locally advanced breast tumours that are initially hypoxic.

  13. Mesoporous LiMnPO4/C nanoparticles as high performance cathode material for lithium ion batteries

    International Nuclear Information System (INIS)

    Wen, Fang; Shu, Hongbo; Zhang, Yuanyuan; Wan, Jiajia; Huang, Weihua; Yang, Xiukang; Yu, Ruizhi; Liu, Li; Wang, Xianyou

    2016-01-01

    LiMnPO 4 has been considered as one of the most promising high voltage cathode materials for next-generation lithium ion batteries. However, LiMnPO 4 suffers from intrinsic drawbacks of extremely low electronic conductivity and ionic diffusivity between LiMnPO 4 /MnPO 4 . In this paper, mesoporous LiMnPO 4 nanoparticles are synthesized successfully via a facile glycine-assisted solvothermal rout. The as-prepared mesoporous LiMnPO 4 /C nanoparticles present well-defined abundant mesoporous structure (diameter of 3 ∼ 10 nm), uniform carbon layer (thickness of 3 ∼ 4 nm), high specific surface area (90.1 m 2 /g). As a result, the mesoporous LiMnPO 4 /C nanoparticles achieve excellent electrochemical performance as cathode materials for lithium ion batteries. It demonstrates a high discharge capacity of 167.7, 161.6, 156.4, 148.4 and 128.7 mAh/g at 0.1, 0.5, 1, 2 and 5C, and maintains a discharge capacity of 130.0 mAh/g after 100 cycles at 1C. The good electrochemical performance is attributed to its special interpenetrating mesoporous structure in LiMnPO 4 nanoparticles, which significantly enhances the ionic and electronic transport and additional capacitive behavior to compensate the sluggish kinetics.

  14. Simultaneous measurement of pO2 and perfusion in the rabbit kidney in vivo.

    Science.gov (United States)

    O'Connor, Paul M; Anderson, Warwick P; Kett, Michelle M; Evans, Roger G

    2007-01-01

    Recently, a combined probe has been developed capable of simultaneous measurement of local tissue pO2 (fluorescence oximetry) and microvascular perfusion (laser Doppler flux) within the same local region. The aim of the current study was to test the utility of these combined probes to measure pO2 and perfusion in the kidney. Studies were performed in anesthetized, artificially ventilated rabbits (n=7). Baseline measurements of renal medullary perfusion and pO2 obtained using combined probes (537 +/- 110 units & 28.7 +/- 6.l mmHg, respectively) were indistinguishable from those obtained using independent probes (435 +/- 102 units & 26.9 +/- 6.4 mmHg). Baseline measurements of renal cortical pO2 were also similar between combined (9.7 +/- 1.6 mmHg) and independent probes (9.5 +/- 2.3 mmHg). Baseline levels of cortical perfusion however, were significantly greater when measured using independent probes (1130 +/- 114 units) compared to combined probes (622 +/- 59 units; P pO2 resulting from graded stimulation of the renal nerves were not significantly different when measured using combined probes to those obtained using independent probes. We conclude that combined probes are equally suitable to independent probes for tissue pO2 and microvascular perfusion measurement in the kidney. Our results raise some concerns regarding the accuracy of these OxyLite fluorescence probes for pO2 measurement in the kidney, particularly within the renal cortex.

  15. MW-assisted synthesis of LiFePO 4 for high power applications

    Science.gov (United States)

    Beninati, Sabina; Damen, Libero; Mastragostino, Marina

    LiFePO 4/C was prepared by solid-state reaction from Li 3PO 4, Fe 3(PO 4) 2·8H 2O, carbon and glucose in a few minutes in a scientific MW (microwave) oven with temperature and power control. The material was characterized by X-ray diffraction, scanning electron microscopy and by TGA analysis to evaluate carbon content. The electrochemical characterization as positive electrode in EC (ethylene carbonate)-DMC (dimethylcarbonate) 1 M LiPF 6 was performed by galvanostatic charge-discharge cycles at C/10 to evaluate specific capacity and by sequences of 10 s discharge-charge pulses, at different high C-rates (5-45C) to evaluate pulse-specific power in simulate operative conditions for full-HEV application. The maximum pulse-specific power and, particularly, pulse efficiency values are quite high and make MW synthesis a very promising route for mass production of LiFePO 4/C for full-HEV batteries at low energy costs.

  16. The size distribution of 210Po in the atmosphere around Mt. Sakurajima in Kagoshima prefecture, Japan

    International Nuclear Information System (INIS)

    Ashikawa, N.; Matsuoka, N.; Takashima, Y.; Syojo, N.; Imamura, H.; Fujisaki, M.

    1998-01-01

    The concentration and size distribution of 210 Po in particulate matters in the atmosphere were measured around the active volcano, Mt. Sakurajima in Kagoshima prefecture, Japan. The samples were collected eight times at four sampling points for the period from June 1994 to January 1996. The highest concentration of 210 Po was 2940 μBq/m 3 at Akamizu located 2 km away from the crater of Mt. Sakurajima. The 210 Po concentrations decreased with the increase of distance form Mt. Sakurajima. The size distribution curves of 210 Po in the particulate matters showed that 210 Po is usually condensed to fine particles smaller than 2 μm in diameter. In addition, it was suggested that the 210 Po concentration in particulate matters collected at Akamizu was affected by the wind direction over Mt. Sakurajima. (author)

  17. Three new d10 transition metal selenites containing PO4 tetrahedron: Cd7(HPO4)2(PO4)2(SeO3)2, Cd6(PO4)1.34(SeO3)4.66 and Zn3(HPO4)(SeO3)2(H2O)

    Science.gov (United States)

    Ma, Yun-Xiang; Gong, Ya-Ping; Hu, Chun-li; Mao, Jiang-Gao; Kong, Fang

    2018-06-01

    Three new d10 transition metal selenites containing PO4 tetrahedron, namely, Cd7(HPO4)2(PO4)2(SeO3)2 (1), Cd6(PO4)1.34(SeO3)4.66 (2) and Zn3(HPO4)(SeO3)2(H2O) (3), have been synthesized by hydrothermal reaction. They feature three different structural types. Compound 1 exhibits a novel 3D network composed of 3D cadmium selenite open framework with phosphate groups filled in the 1D helical tunnels. The structure of compound 2 displays a new 3D framework consisted of 2D cadmium oxide layers bridged by SeO3 and PO4 groups. Compound 3 is isostructural with the reported solids of Co3(SeO3)3-x(PO3OH)x(H2O) when x is equal to 1.0. Its structure could be viewed as a 3D zinc oxide open skeleton with SeO3 and HPO4 polyhedra attached on the wall of the tunnels. They represent the only examples in metal selenite phosphates in addition to the above cobalt compounds. Optical diffuse reflectance spectra revealed that these solids are insulators, which are consistent with the results of band structure computations based on DFT algorithm.

  18. A new semi-invasive method for two dimensional pO2 measurements of cortical structures.

    Science.gov (United States)

    Warnat, Jan; Liebsch, Gregor; Stoerr, Eva-Maria; Brawanski, Alexander; Woertgen, Chris

    2008-01-01

    Measuring brain oxygenation in patients with TBI or SAH is of major interest. We present a new semi-invasive method for two dimensional measurements of cortical pO2. For this feasibility study, a porphyrin containing sensor foil was placed directly on the cortex of intubated and variably ventilated Wistar rats. The sensor was excited with a light pulse and pictures of the foil's pO2 dependant emissions were captured with a CCD camera. After online data processing, two-dimensional maps of cortex oxygenation were displayed and analyzed using ROIs (here: arteriole, vein, parenchyma) with a display rate of 7 Hz. The size of one single measurement pixel was 0.03 x 0.03 mm2. The mean pO2 over cortex arterioles was 20.3 +/- 0.69, over veins 17.1 +/- 0.5 and over parenchyma 9.1 +/- 0.6 (mmHg +/- SD). The arterial pO2 showed a good correlation to the pO2 in the ROIs (r = 0.46-0.72, p pO2 values in the ROIs of the cortex. This prototype is capable of obtaining cortical pO2 maps with excellent temporal and spatial resolution and provides simultaneous imaging of the cortex structures.

  19. A study on 210Po activity concentration in soil at different depths along coastal Kerala

    International Nuclear Information System (INIS)

    Primal D'Cunha; Sathyanarayana Bhat, P.; Narayana, Y.

    2011-01-01

    The paper presents systematic studies on the vertical profiles of 210 Po, an important decay product of 238 U, in soils along coastal Kerala. Soil samples collected from different depth intervals 0-10, 10-20, 20-30 cm were analyzed for 210 Po activity concentration by radiochemical methods. The activity 210 Po in soil samples were counted using a ZnS(Ag) alpha scintillation counting system. The mean values of activity concentrations of 210 Po in soil of various depths were found to be 8.66, 5.63 and 4.95 Bq kg -1 for depth intervals of 0-10, 10-20 and 20-30 cm, respectively. The overall activity concentration of 210 Po in soil was found to vary from 2.26 ± 0.19 to 14.02 ± 0.12 Bq kg -1 with a mean value of 6.43 Bq kg -1 . Maximum activity concentration was found in soil samples of Kollam region with the mean value of 10.08 ± 0.92 Bq kg -1 . The activity of 210 Po was found to be comparatively high in surface soil. The variation of 210 Po activity concentration with organic matter contents was studied. 210 Polonium activity concentration was found to increase with increasing organic matter content. (author)

  20. Structural features of AgCaCdMg2(PO4)3 and AgCd2Mg2(PO4)3, two new compounds with the alluaudite-type structure, and their catalytic activity in butan-2-ol conversion

    International Nuclear Information System (INIS)

    Kacimi, Mohammed; Ziyad, Mahfoud; Hatert, Frederic

    2005-01-01

    AgCaCdMg 2 (PO 4 ) 3 and AgCd 2 Mg 2 (PO 4 ) 3 , two new compounds with the alluaudite-type structure, were synthesized by a solid state reaction in air at 750 deg. C. The X-ray powder diffraction pattern of AgCaCdMg 2 (PO 4 ) 3 indicates the presence of small amounts of (Ca, Mg) 3 (PO 4 ) 2 with the whitlockite structure, as impurity, whereas AgCd 2 Mg 2 (PO 4 ) 3 is constituted by pure alluaudite. The Rietveld refinements of the X-ray powder diffraction patterns indicate an ordered cationic distribution for AgCd 2 Mg 2 (PO 4 ) 3 , with Ag on A(2)', Cd on A(1) and M(1), and Mg on M(2), whereas a disordered distribution of Cd and Ca between the A(1) and M(1) sites is observed for AgCaCdMg 2 (PO 4 ) 3 . The catalytic properties of these compounds has been measured in reaction of butan-2-ol dehydrogenation. In the absence of oxygen, both samples exhibit poor dehydrogenation activity. All samples displayed no dehydration activity. Introduction of oxygen into the feed changed totally the catalytic behavior of the catalysts. The production of methyl ethyl ketone increases with time on stream and the reaction temperature. AgCaCdMg 2 (PO 4 ) 3 is more efficient than AgCd 2 Mg 2 (PO 4 ) 3

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-01

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

  2. Sodium intercalation in the phosphosulfate cathode NaFe2(PO4)(SO4)2

    Science.gov (United States)

    Ben Yahia, Hamdi; Essehli, Rachid; Amin, Ruhul; Boulahya, Khalid; Okumura, Toyoki; Belharouak, Ilias

    2018-04-01

    The compound NaFe2(PO4)(SO4)2 is successfully synthesized via a solid state reaction route and its crystal structure is determined using powder X-ray diffraction data. NaFe2(PO4)(SO4)2 phase is also characterized by cyclic voltammetry, galvanostatic cycling and electrochemical impedance spectroscopy. NaFe2(PO4)(SO4)2 crystallizes with the well-known NASICON-type structure. SAED and HRTEM experiments confirm the structural model, and no ordering between the PO4-3 and SO4-2 polyanions is detected. The electrochemical tests indicate that NaFe2(PO4)(SO4)2 is a 3 V sodium intercalating cathode. The electrical conductivity is relatively low (2.2 × 10-6 Scm-1 at 200 °C) and the obtained activation energy is ∼0.60eV. The GITT experiments indicate that the diffusivity values are in the range of 10-11-10-12 cm2/s within the measured sodium concentrations.

  3. The effect of heat preservation time on the electrochemical properties of LiFePO4

    Science.gov (United States)

    He, Rui; Zhang, Lihui; Bai, Xue; Liu, Zhenfa

    2017-12-01

    LiFePO4 was prepared via high temperature solid-state method at different heat preservation time. XRD and SEM was used to test the structure and morphology of LiFePO4. Land 2001 was used to test the electrochemical performance of LiFePO4. The results illustrated that well-crystallized LiFePO4 composite with homogeneous small particles was obtained by XRD and SEM. And the optimum heat preservation time was 4 hour. From charge/discharge test, it can be seen that at 0.2C, LiFePO4 has initial discharge capacities of 159.1mAh/g at the heat preservation time 4 hour. From the rate capacity, it can be seen that the discharge capacity was of optimum sample remains above 99% after 200 cycles.

  4. Structural Transformation of LiFePO4 during Ultrafast Delithiation.

    Science.gov (United States)

    Kuss, Christian; Trinh, Ngoc Duc; Andjelic, Stefan; Saulnier, Mathieu; Dufresne, Eric M; Liang, Guoxian; Schougaard, Steen B

    2017-12-21

    The prolific lithium battery electrode material lithium iron phosphate (LiFePO 4 ) stores and releases lithium ions by undergoing a crystallographic phase change. Nevertheless, it performs unexpectedly well at high rate and exhibits good cycling stability. We investigate here the ultrafast charging reaction to resolve the underlying mechanism while avoiding the limitations of prevailing electrochemical methods by using a gaseous oxidant to deintercalate lithium from the LiFePO 4 structure. Oxidizing LiFePO 4 with nitrogen dioxide gas reveals structural changes through in situ synchrotron X-ray diffraction and electronic changes through in situ UV/vis reflectance spectroscopy. This study clearly shows that ultrahigh rates reaching 100% state of charge in 10 s does not lead to a particle-wide union of the olivine and heterosite structures. An extensive solid solution phase is therefore not a prerequisite for ultrafast charge/discharge.

  5. Enhanced electrochemical performance of LiMnPO4 by Li+-conductive Li3VO4 surface coatings

    International Nuclear Information System (INIS)

    Dong, Youzhong; Zhao, Yanming; Duan, He; Liang, Zhiyong

    2014-01-01

    By a simple wet ball-milling method, Li 3 VO 4 -coated LiMnPO 4 samples were prepared successfully for the first time. The thin Li 3 VO 4 coating layer with a three-dimensional Li + -ion transport path and high mobility of Li + -ion strongly adhered to the LiMnPO 4 material reduces Mn dissolution and increases the Li + flux through the surface of the LiMnPO 4 itself by preventing formation of phases on the surface that would normally block Li + as well as Li + -ion permeation into the surface of the LiMnPO 4 electrode and therefore improve the rate capability as well as the cycling stability of LiMnPO 4 materials. The electrochemical testing shows that the 5% Li 3 VO 4 -coated LiMnPO 4 sample shows a clear voltage plateau in the charge curves and a much higher reversible capacity at different discharge rates compared with the pristine LiMnPO 4 . EIS results also show that the surface charge transfer resistance and Warburg impedance of the Li 3 VO 4 -coated LiMnPO 4 samples significantly decreased. The surface charge transfer resistance and Warburg impedance for the pristine LiMnPO 4 are 955.1 Ω and 400.3 Ω, respectively. While, for the 5% Li 3 VO 4 -coated LiMnPO 4 , the value are only 400.2 Ω and 283.6 Ω, respectively. The surface charge transfer resistance decreases more than half. All of the improved performance will be favorable for application of the LiMnPO 4 in high-power lithium ion batteries

  6. Probing the failure mechanism of nanoscale LiFePO4 for Li-ion batteries

    International Nuclear Information System (INIS)

    Gu, Meng; Yan, Pengfei; Wang, Chongmin; Shi, Wei; Zheng, Jianming; Zhang, Ji-guang

    2015-01-01

    LiFePO 4 is a high power rate cathode material for lithium ion battery and shows remarkable capacity retention, featuring a 91% capacity retention after 3300 cycles. In this work, we use high-resolution transmission electron microscopy and electron energy loss spectroscopy to study the gradual capacity fading mechanism of LiFePO 4 materials. We found that upon prolonged electrochemical cycling of the battery, the LiFePO 4 cathode shows surface amorphization and loss of oxygen species, which directly contribute to the gradual capacity fading of the battery. The finding can guide the design and improvement of LiFePO 4 cathode for high-energy and high-power rechargeable battery for electric transportation

  7. Intake of 210Po, 234U and 238U radionuclides with beer in Poland

    International Nuclear Information System (INIS)

    Skwarzec, B.; Struminska, D.I.; Borylo, A.; Falandysz, J.

    2004-01-01

    238 U, 234 U and 210 Po activity concentrations were determined in beer in Poland by alpha-spectrometry with low-level activity silicon detectors. The results revealed that the mean concentrations of 238 U, 234 U and 210 Po in the analyzed beer samples were 4.63, 4.11 and 4.94 mBq x dm -3 , respectively, the highest in Tyskie (5.71 for 210 Po, 5.06 for 234 U and 6.11 for 238 U) and the lowest in Lech (2.49 for 210 Po). The effective radiation dose due to uranium and polonium ingestions by beer was calculated and were compared to the effective radiation dose from drinking water. (author)

  8. Electron-impact study of PO2 using the R-matrix method

    Science.gov (United States)

    Bharadvaja, Anand; Kaur, Savinder; Baluja, K. L.

    2013-06-01

    The R-matrix approach is used to study the electron scattering from PO2 radical at low electron impact energies. The elastic scattering phenomenon is studied in static-exchange, one-state and many-states close-coupling approximation. The elastic differential cross sections, corresponding momentum-transfer cross sections, and collision frequency are calculated in the one-state configuration interaction approximation only. Calculations reveal a stable bound state of PO2- having symmetry 1A1, a configuration of ⋯8a12,⋯2b12,⋯5b22,⋯1a22, and vertical electron affinity of 2.94 eV. The excited state of anion PO2- having symmetry 3B1 is also just bound relative to the ground state of PO2 at its equilibrium geometry. The shape, core-excited, and Feshbach resonances are analyzed in different symmetries up to 7 eV. The partial waves up to l=4 are used to represent continuum electron. The converged cross sections are obtained for the partial waves having l greater than 4 by applying Born correction. Certain interesting spectroscopic properties of radical are also reported.

  9. Evolution of LiFePO4 thin films interphase with electrolyte

    Science.gov (United States)

    Dupré, N.; Cuisinier, M.; Zheng, Y.; Fernandez, V.; Hamon, J.; Hirayama, M.; Kanno, R.; Guyomard, D.

    2018-04-01

    Many parameters may control the growth and the characteristics of the interphase, such as surface structure and morphology, structural defects, grain boundaries, surface reactions, etc. However, polycrystalline surfaces contain these parameters simultaneously, resulting in a quite complicated system to study. Working with model electrode surfaces using crystallographically oriented crystalline thin films appears as a novel and unique approach to understand contributions of preferential orientation and rugosity of the surface. In order to rebuild the interphase architecture along electrochemical cycling, LiFePO4 epitaxial films offering ideal 2D (100) interfaces are here investigated through the use of non-destructive depth profiling by Angular Resolved X-ray Photoelectron Spectroscopy (ARXPS). The composition and structure of the interphase is then monitored upon cycling for samples stopped at the end of charge and discharge for various numbers of cycles, and discussed in the light of combined XPS and X-ray reflectivity (XRR) measurements. Such an approach allows describing the interphase evolution on a specific model LiFePO4 crystallographic orientation and helps understanding the nature and evolution of the LiFePO4/electrolyte interphase forming on the surface of LiFePO4 poly-crystalline powder.

  10. Improved analytical procedure for the determination of 210Pb and 210Po using alpha-spectrometric isotope dilution

    International Nuclear Information System (INIS)

    Urnezis, P.W.; Holtzman, R.B.

    1981-01-01

    An isotope dilution method has been incorporated into the 210 Pb- 210 Po analysis. A known amount of 209 Po is added to the sample before analysis. Then both 209 Po and 210 Po are deposited on a silver planchet which is assayed in an alpha spectrometer to determine the activities of each isotope. The recoveries generally range from 70% to 90%

  11. 210Po measurement of borehole core and its significance for uranium exploration

    International Nuclear Information System (INIS)

    Chao Xiaolin

    2007-01-01

    210 Po survey is a tradition method in uranium exploration and has been widely applied to ground reconnaissance survey and detailed survey of uranium. However, it is seldom applied to drilling work. 210 Po measurements of borehole core for granite-type uranium deposit in Miaoershan area indicate that there are high and large range anomaly which greatly exceeds uranium orebody in uranium mineralization area. The investigation suggests that 210 Po measurements of borehole core can judge whether or not exist buried uranium orebody under the borehole depth and its surrounding in the final exploration stage. The method may be used to the exploration of granite-type uranium deposit. (authors)

  12. Résister : les poèmes de guerre de Charles Camproux

    OpenAIRE

    Lassaque, Aurélia

    2014-01-01

    Charles Camproux, né à Marseille en 1908, fut publiquement reconnu comme poète suite à la parution des Poemas sens poesia. Ce premier recueil portant sur la captivité, composé « sot lo ceu d’Alemanha », fut publié peu après le retour de Camproux en France, par les soins d’Ismaël Girard à la SEO en 1942. Camproux composa au cours des deux années suivantes un ensemble de poèmes réunis tardivement sous le titre de Poëmas de Resistència. Contrairement à L’an quaranta e tres et au Bestiari, écrits...

  13. Analysis of 210Pb and 210Po concentrations in surface air by an α spectrometric method

    International Nuclear Information System (INIS)

    Winkler, R.; Hoetzl, H.; Chatterjee, B.

    1981-01-01

    A method is presented for determining the concentrations of airborne 210 Pb and 210 Po. The method employs α spectrometry to measure the count rate of 210 Po present on an electrostatic filter sample at two post-sampling times. The individual air concentrations of 210 Po and 210 Pb can be calculated from equations given. Sensitivity of the procedure is about 0.2 fCi 210 Po per m 3 of air. The method was applied to the study of long-term variations and frequency distributions of 210 Po and 210 Pb concentrations in surface air at a nonpolluted location about 10 km outside of Munich, F.R.G., from 1976 through 1979. During this period the average concentration levels were found to be 14.2 fCi 210 Pb per m 3 of air and 0.77 fCi 210 Po per m 3 of air, respectively. (author)

  14. 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

  15. Controlled synthesis and photocatalytic properties of rhombic dodecahedral Ag3PO4 with high surface energy

    International Nuclear Information System (INIS)

    Xie, Yao; Huang, Zhaohui; Zhang, Zhijie; Zhang, Xiaoguang; Wen, Ruilong; Liu, Yangai; Fang, Minghao; Wu, Xiaowen

    2016-01-01

    Graphical abstract: The high amount of rhombic dodecahedral Ag 3 PO 4 particles with a high exposure of the {110} facets and high surface energy (the surface energy of the {110} facets was 1.31 J/m 2 , greater than that of the {100} facet (1.12 J/m 2 ).) exhibited excellent photocatalytic activity. - Highlights: • High contents of rhombic dodecahedral Ag 3 PO 4 photocatalysts are prepared. • Excessive EG can destroy the morphology of Ag 3 PO 4 in synthesis process. • The rhombic dodecahedral Ag 3 PO 4 exhibits high surface energy. • High surface energy implies high photocatalytic activity. - Abstract: In this study, a series of Ag 3 PO 4 photocatalysts with different contents of rhombic dodecahedral particles were prepared in one pot by a facile, novel hydrothermal method using ethylene glycol (EG), which served as both a morphology modifier and reducing agent. The effects of EG content on the morphologies of Ag 3 PO 4 photocatalysts were discussed. The photocatalytic activity of the Ag 3 PO 4 photocatalysts was evaluated by the degradation of methylene blue trihydrate under visible-light irradiation. With the use of 0.8% EG in the reaction solvent, the sample exhibited excellent photocatalytic activity, attributed to the high amount of rhombic dodecahedral Ag 3 PO 4 particles with a high exposure of the {110} facets and high surface energy. The surface energy of the {110} facets was 1.31 J/m 2 , greater than that of the {100} facet (1.12 J/m 2 ). However, with 1% EG in the reaction solvent, although the Ag 3 PO 4 photocatalysts were composed of a majority of rhombic dodecahedral Ag 3 PO 4 particles, tiny Ag particles formed from Ag + under the action of EG attached on the surface of the sample decreased the absorption of visible light, resulting in low photocatalytic activity.

  16. Luminescence and energy transfer of Sm3+ and Eu3+ in Ca2PO4Cl

    International Nuclear Information System (INIS)

    Wang, Zhijun; Li, Panlai; Yang, Zhiping; Guo, Qinglin

    2014-01-01

    Sm 3+ , Eu 3+ , and Sm 3+ –Eu 3+ doped Ca 2 PO 4 Cl phosphors are synthesized by a solid-state method. Ca 2 PO 4 Cl:Sm 3+ can produce red emission under the 400 nm radiation excitation, and the emission peak is located at 601 nm, which is assigned to the 4 G 5/2 → 6 H 7/2 transition of Sm 3+ . Ca 2 PO 4 Cl:Eu 3+ can create red emission under the 392 nm radiation excitation, and the strongest peak is located at 620 nm, which is attributed to the 5 D 0 → 7 F 2 transition of Eu 3+ . The energy transfer from Sm 3+ to Eu 3+ in Ca 2 PO 4 Cl has been validated and the critical distance (R c ) of Sm 3+ to Eu 3+ in Ca 2 PO 4 Cl is calculated to be 1.14 nm. With increasing Eu 3+ doping concentration, the energy transfer efficiency (Sm 3+ →Eu 3+ ) gradually increases to 53.7%. The luminescence property of Ca 2 PO 4 Cl:Sm 3+ , Eu 3+ can be tuned by properly tuning the relative ratio of Sm 3+ –Eu 3+ , and the emission intensity of Ca 2 PO 4 Cl:Eu 3+ can be greatly enhanced by codoped Sm 3+ . - Highlights: • Ca 2 PO 4 Cl:Sm 3+ , Eu 3+ can produce red emission under the 400 nm radiation excitation. • The energy transfer from Sm 3+ to Eu 3+ in Ca 2 PO 4 Cl has been validated. • The critical distance of Sm 3+ to Eu 3+ in Ca 2 PO 4 Cl is calculated to be 1.14 nm

  17. A short-breath-hold technique for lung pO2 mapping with 3He MRI.

    Science.gov (United States)

    Miller, G Wilson; Mugler, John P; Altes, Talissa A; Cai, Jing; Mata, Jaime F; de Lange, Eduard E; Tobias, William A; Cates, Gordon D; Brookeman, James R

    2010-01-01

    A pulse-sequence strategy was developed for generating regional maps of alveolar oxygen partial pressure (pO2) in a single 6-sec breath hold, for use in human subjects with impaired lung function. Like previously described methods, pO2 values are obtained by measuring the oxygen-induced T1 relaxation of inhaled hyperpolarized 3He. Unlike other methods, only two 3He images are acquired: one with reverse-centric and the other with centric phase-encoding order. This phase-encoding arrangement minimizes the effects of regional flip-angle variations, so that an accurate map of instantaneous pO2 can be calculated from two images acquired a few seconds apart. By combining this phase-encoding strategy with variable flip angles, the vast majority of the hyperpolarized magnetization goes directly into the T1 measurement, minimizing noise in the resulting pO2 map. The short-breath-hold pulse sequence was tested in phantoms containing known O2 concentrations. The mean difference between measured and prepared pO2 values was 1 mm Hg. The method was also tested in four healthy volunteers and three lung-transplant patients. Maps of healthy subjects were largely uniform, whereas focal regions of abnormal pO2 were observed in diseased subjects. Mean pO2 values varied with inhaled O2 concentration. Mean pO2 was consistent with normal steady-state values in subjects who inhaled 3He diluted only with room air. Copyright (c) 2009 Wiley-Liss, Inc.

  18. Solvothermal synthesis and electrochemical performance of hollow LiFePO{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Zhenmiao [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Pang, Wei Kong [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2522 (Australia); Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Tang, Xincun, E-mail: tangxincun@163.com [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Jia, Dianzeng; Huang, Yudai [Institute of Applied Chemistry, Xinjiang University, Urumqi 840046 (China); Guo, Zaiping [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2522 (Australia)

    2015-08-15

    Highlights: • Hollow LiFePO{sub 4} nanoparticles were successfully synthesized via solvothermal method. • The shorter b lattice parameter allows the shorter diffusion path of lithium ion. • Hollow LiFePO{sub 4} nanoparticles show better rate capability than solid LiFePO{sub 4}. - Abstract: Hollow LiFePO{sub 4} nanoparticles were synthesized via a solvothermal technique, using ammonium tartrate as additive and carbon source, and ethylene glycol/water as solvent. The as-prepared samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, scanning and transmission electron microscopies, and Brunauer–Emmett–Teller specific surface area measurements. The electrochemical properties of the LiFePO{sub 4} cathode were examined in coin-type cell configuration and the cathode exhibited excellent rate capability (i.e., discharge capacity of 120.9 mA h g{sup −1} at 10 C) and cycling performance (i.e., >98% of capacity retention rate after 50 cycles). It is believed that the enhanced performance is correlated to the hollow structure, small crystallite and particle sizes, and relatively shorter lattice parameter b.

  19. Ingestion dose from 210Po due to the consumption of packaged drinking water

    International Nuclear Information System (INIS)

    Nair, Madhu G.; Rao, D.D.; Sreejith, Sathyapriya R.; Sarka, P.K.

    2013-01-01

    Humans are chronically exposed to naturally occurring radionuclides from uranium and thorium series via inhalation and ingestion. With increased interest in radiological assessment a study was taken up for assessing natural radioactivity in drinking water. Drinking water is an important route of intake of naturally occurring 210 Po. 210 Po being a very important radionuclide from Uranium series with high specific activity causes significant internal dose. In our study 210 Po in PDW was concentrated with calcium phosphate and spontaneously deposited onto silver planchette and subsequently measured by alpha spectrometry. The concentration of 210 Po in the bottled water ranged from 0.11 mBq.l -1 to 2.9 mBq.l -1 . The highest concentration was observed in that sample that was reportedly sourced from mountain regions. Based on the concentration of 210 Po in each water sample, the annual intake rate (1.68L/d), and the Dose Coefficient (1.2 X 10 -6 Vs./Bq) recommended by the International Commission on Radiological Protection (ICRP, 1996), the annual committed effective doses to the adult population was estimated. The annual effective doses ranged between 0.10-2.16 μSv/yr. (author)

  20. Po-210 high levels in aquatic plants of the Carapebus sandbank, RJ, Brazil

    International Nuclear Information System (INIS)

    Kelecom, Alphonse; Santos, Pedro Lopes dos; Gouvea, Rita de Cassis S.; Dutra, Iedo Ramos; Fevereiro, Paulo Cesar Ayres

    1999-01-01

    210 Po concentration have been determined in one green alga and in five freshwater plants grown in a pond of the Carapebus restinga (state of Rio de Janeiro). The alga Chara sp showed elevated concentration of 210 Po, similar to that observed in marine algae. All the other plants had the lowest concentration of 210 Po in the stems and the highest in the roots. Intermediate values were observed in the leaves. The unexpected high concentration of 210 Po in the roots, even superior to reported values for roots of plants from high radioactive background areas, must be due to the elevated levels of this radionuclide in associated soils that are known to be rich in humic organic material. There seem to have no translocation of this radionuclide from the roots to the other parts of the plants. (author)

  1. Na3Tb(PO4)2: Synthesis, crystal structure and greenish emitting properties

    Science.gov (United States)

    Zhao, Dan; Ma, Zhao; Liu, Bao-Zhong; Zhang, Rui-Juan; Wu, Zhi-Qiang; Wang, Jian; Duan, Pei-Gao

    2018-03-01

    A anhydrous orthoborate Na3Tb(PO4)2 has been prepared and its crystal structure was determined by X-Ray diffraction of a non-merohedral twinned single crystal. The results show that the compound crystallizes in monoclinic space group C2/c and the structure features a 3D framework containing PO4, NaO6, NaO7, NaO8 and TbO8 polyhedra. Under near-UV excitation (370 nm), Na3Tb(PO4)2 shows intense characteristic emission bands of Tb3+ (490 nm, 543 nm, 585 nm and 620 nm) with the CIE coordinate of (0.3062, 0.5901), corresponding to greenish color. The excitation spectrum covers a wide range from 340 nm to 390 nm, which indicates that phosphor Na3Tb(PO4)2 can be efficiently activated by near-UV LED ship.

  2. Natural Radioisotopes of Pb, Bi and Po in the Atmosphere of Coal Burning Area

    Directory of Open Access Journals (Sweden)

    Asnor Azrin Sabuti

    2011-07-01

    Full Text Available This paper is discussing the changes of natural radionuclides 210Pb, 210Bi and 210Po in atmospheric samples (rainwater and solid fallout caused by Sultan Salahuddin Abdul Aziz coal-fired Power Plant (SSAAPP operation. We also describe the seasonal changes of 210Pb, 210Bi and 210Po to the monsoon seasons in Peninsular Malaysia. Bulk atmospheric trap was used to collect atmospheric samples for five months (7 Feb 2007 to 27 July 2007 and placed within the SSAAPP area. The natural radionuclide activity levels in the atmosphere were affected by local meteorological conditions to impact their variance over time. As a result, the natural radionulides were increased from the ambient value in atmospheric particles (solid fallout, which related to coal combustion by-product releases into atmosphere. In contrast, this was giving relatively lower or in the same magnitude from most places of radionuclides in rainwater samples. Degree of changes between 210Pb, 210Bi and 210Po affected by high temperature combustions were found to be different for each nuclide due to their respective volatility. 210Po in rainwater and solid fallout were considerably low during early inter-monsoon period which mainly controlled by the rainfall pattern. On the other hand, 210Pb and 210Bi in solid fallout were recorded higher concentrations which associated to drier conditions and more particulate content in air column during southwest monsoon. The mean activity ratio of 210BiRW/210PbRW and 210PoRW/210PbRW are 0.47 ± 0.04 and 0.52 ± 0.17, respectively. Whereas for 210BiSF/210PbSF and 210PoSF/210PbSF are 0.52 ± 0.05 and 0.71 ± 0.13, respectively. Some results showed high activity ratios, reaching to 1.87 ± 0.08 for 210Bi/210Pb and 4.58 ± 0.55 for 210Po/210Pb, of which due to additional of 210Bi and 210Po excess. These ratios also indicating that 210Pb and 210Bi could potentially come from the same source, compared to 210Po which varied differently, showing evidence it came

  3. Thermal analysis of a LiFePo4 Battery

    OpenAIRE

    Balanguer Escolano, David

    2014-01-01

    The objective of this final thesis project was to study and test a 3,3V LiFePo4 battery in outer space conditions to be able to determine its working range, its limitations and its problems. To do so a measuring set-up to read and estimate the capacity of a battery was built and programmed. Then the LiFePo4 battery was tested at different temperatures between -20°C and 40°C in a vacuum chamber at a pressure under 100 microbars. The results showed that the battery can still operate prope...

  4. Natural concentrations of Pb/sup 210/ and Po/sup 210/ in plants of steppe phytocoenoses

    Energy Technology Data Exchange (ETDEWEB)

    Ladinskaya, L A; Parfenov, Yu D; Arutyunov, P S; Popov, D K [Leningradskij Inst. Radiatsionnoj Gigieny (USSR)

    1976-01-01

    Data are presented on the concentration of /sup 210/Pb and /sup 210/Po in summer vegetation in the aerial and root parts of sown fodder crops from steppes, saline meadows and marshy meadows and also in the leaves and branches of trees and bushes. The average concentrations of /sup 110/Pb and /sup 210/Po in the plants of individual communities have been evaluated, together with the /sup 210/Po//sup 210/Pb ratios in the aerial parts and roots and the accumulation coefficients. The variation distribution of the /sup 210/Po and /sup 210/Pb concentrations follows a log-normal law.

  5. Ionothermal synthesis, crystal structure, and magnetic study of Co2PO4OH isostructural with caminite.

    Science.gov (United States)

    Wang, Guangmei; Valldor, Martin; Spielberg, Eike T; Mudring, Anja-Verena

    2014-03-17

    A new framework cobalt(II) hydroxyl phosphate, Co2PO4OH, was prepared by ionothermal synthesis using 1-butyl-4-methyl-pyridinium hexafluorophosphate as the ionic liquid. As the formation of Co2PO4F competes in the synthesis, the synthesis conditions have to be judiciously chosen to obtain well-crystallized, single phase Co2PO4OH. Single-crystal X-ray diffraction analyses reveal Co2PO4OH crystallizes with space group I41/amd (a = b = 5.2713(7) Å, c = 12.907(3) Å, V = 358.63(10) Å(3), and Z = 4). Astonishingly, it does not crystallize isotypically with Co2PO4F but rather isotypically with the hydroxyl minerals caminite Mg1.33[SO4(OH)0.66(H2O)0.33] and lipscombite Fe(2–y)PO4(OH) (0 ≤ y ≤ 2/3). Phosphate tetrahedra groups interconnect four rod-packed face-sharing ∞(1){CoO(6/2)} octahedra chains to form a three-dimensional framework structure. The compound Co2PO4OH was further characterized by powder X-ray diffraction, Fourier transform–infrared, and ultraviolet–visible spectroscopy, confirming the discussed structure. The magnetic measurement reveals that Co2PO4OH undergoes a magnetic transition and presents at low temperatures a canted antiferromagnetic spin order in the ground state.

  6. Surprising luminescent properties of the polyphosphates Ln(PO3)3:Eu (Ln = Y, Gd, Lu).

    Science.gov (United States)

    Höppe, Henning A; Kazmierczak, Karolina; Kacprzak, Sylwia; Schellenberg, Inga; Pöttgen, Rainer

    2011-10-21

    The optical emission properties of the lanthanoid catena-polyphosphates Ln(PO(3))(3) (Ln = Y, Gd, Lu) doped with europium were investigated. Incommensurately modulated β-Y(PO(3))(3):Eu (super space group Cc (0|0.364|0)0) and Gd(PO(3))(3):Eu (space group I2/a) show the usual emission characteristics of Eu(3+), while in Lu(PO(3))(3):Eu (space group Cc) the europium is unprecedentedly partially reduced to the divalent state, as proven by both a broad emission band at 406 nm excited at 279 nm and an EPR spectroscopic investigation. (151)Eu-Mössbauer spectroscopy showed that only a very small part of the europium is reduced in Lu(PO(3))(3):Eu. An explanation for this unusual behaviour is given. This journal is © The Royal Society of Chemistry 2011

  7. Facile One-Step Sonochemical Synthesis and Photocatalytic Properties of Graphene/Ag3PO4 Quantum Dots Composites

    Science.gov (United States)

    Reheman, Abulajiang; Tursun, Yalkunjan; Dilinuer, Talifu; Halidan, Maimaiti; Kadeer, Kuerbangnisha; Abulizi, Abulikemu

    2018-03-01

    In this study, a novel graphene/Ag3PO4 quantum dot (rGO/Ag3PO4 QD) composite was successfully synthesized via a facile one-step photo-ultrasonic-assisted reduction method for the first time. The composites were analyzed by various techniques. According to the obtained results, Ag3PO4 QDs with a size of 1-4 nm were uniformly dispersed on rGO nanosheets to form rGO/Ag3PO4 QD composites. The photocatalytic activity of rGO/Ag3PO4 QD composites was evaluated by the decomposition of methylene blue (MB). Meanwhile, effects of the surfactant dosage and the amount of rGO on the photocatalytic activity were also investigated. It was found that rGO/Ag3PO4 QDs (WrGO:Wcomposite = 2.3%) composite exhibited better photocatalytic activity and stability with degrading 97.5% of MB within 5 min. The improved photocatalytic activities and stabilities were majorly related to the synergistic effect between Ag3PO4 QDs and rGO with high specific surface area, which gave rise to efficient interfacial transfer of photogenerated electrons and holes on both materials. Moreover, possible formation and photocatalytic mechanisms of rGO/Ag3PO4 QDs were proposed. The obtained rGO/Ag3PO4 QDs photocatalysts would have great potentials in sewage treatment and water splitting.

  8. 21 CFR 868.1200 - Indwelling blood oxygen partial pressure (PO2) analyzer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Indwelling blood oxygen partial pressure (PO2... Indwelling blood oxygen partial pressure (PO2) analyzer. (a) Identification. An indwelling blood oxygen... electrode) and that is used to measure, in vivo, the partial pressure of oxygen in blood to aid in...

  9. Po2 cycling protects diaphragm function during reoxygenation via ROS, Akt, ERK, and mitochondrial channels.

    Science.gov (United States)

    Zuo, Li; Pannell, Benjamin K; Re, Anthony T; Best, Thomas M; Wagner, Peter D

    2015-12-01

    Po2 cycling, often referred to as intermittent hypoxia, involves exposing tissues to brief cycles of low oxygen environments immediately followed by hyperoxic conditions. After experiencing long-term hypoxia, muscle can be damaged during the subsequent reintroduction of oxygen, which leads to muscle dysfunction via reperfusion injury. The protective effect and mechanism behind Po2 cycling in skeletal muscle during reoxygenation have yet to be fully elucidated. We hypothesize that Po2 cycling effectively increases muscle fatigue resistance through reactive oxygen species (ROS), protein kinase B (Akt), extracellular signal-regulated kinase (ERK), and certain mitochondrial channels during reoxygenation. Using a dihydrofluorescein fluorescent probe, we detected the production of ROS in mouse diaphragmatic skeletal muscle in real time under confocal microscopy. Muscles treated with Po2 cycling displayed significantly attenuated ROS levels (n = 5; P ROS, Akt, ERK, as well as chemical stimulators to close mitochondrial ATP-sensitive potassium channel (KATP) or open mitochondrial permeability transition pore (mPTP). All these blockers or stimulators abolished improved muscle function with Po2 cycling treatment. This current investigation has discovered a correlation between KATP and mPTP and the Po2 cycling pathway in diaphragmatic skeletal muscle. Thus we have identified a unique signaling pathway that may involve ROS, Akt, ERK, and mitochondrial channels responsible for Po2 cycling protection during reoxygenation conditions in the diaphragm. Copyright © 2015 the American Physiological Society.

  10. Spatial and depth variation of 210Po and 210Pb in monazite sand along HBRA of coastal Kerala

    International Nuclear Information System (INIS)

    D'Cunha, Primal; Narayana, Y.

    2013-01-01

    The samples collected from high background radiation area were analyzed for 210 Po and 210 Pb activities in order to understand their distribution, enrichment and depth profile in the beach sand. The 210 Po and 210 Pb activities vary from 1.85 to 31.27 Bq kg -1 and 9.77 to 132.30 Bq kg -1 respectively. The 210 Po/ 210 Pb indicate that the radionuclides 210 Po and 210 Pb are not in equilibrium and the accumulation of 210 Pb in sand is greater than for 210 Po. The spatial variations of 210 Po and 210 Pb activities were studied in detail. (author)

  11. Organophosphonic acid as precursor to prepare LiFePO4/carbon nanocomposites for high-power lithium ion batteries

    International Nuclear Information System (INIS)

    Chen, Ming; Shao, Leng-Leng; Yang, Hua-Bin; Zhao, Qian-Yong; Yuan, Zhong-Yong

    2015-01-01

    Graphical abstract: LiFePO4/C nanocomposites were prepared by a quasi-sol–gel method with the use of organophosphonic acid, exhibiting improved electrochemical performance with excellent cycle stability. Display Omitted -- Highlights: •Amino tris(methylene phosphonic acid) is served as a novel precursor for LiFePO 4 /C. •Nano-sized and high-purity LiFePO 4 /C composites are obtained by a quasi-sol–gel route. •Core-shell structured LiFePO 4 /C nanocomposites are fabricated by further introducing sucrose. •Superior electrochemical performance is observed in the organophosphorus-synthesized LiFePO 4 /C. -- Abstract: Amino tris(methylene phosphonic acid) (ATMP) is selected as phosphorus and carbon co-source for the synthesis of uniformly nano-sized LiFePO 4 /C by a quasi-sol–gel method. This strategy using ATMP instead of conventional NH 4 H 2 PO 4 supplies two advantages: firstly, ATMP in situ chelates Li + onto its framework and subsequently binds with FeC 2 O 4 in aqueous solution, forming a molecule-scale homogeneous precursor which can obviously improve the purity of LiFePO 4 . Secondly, the organic carbon contained in ATMP can form uniformly distributed conductive carbon networks among LiFePO 4 particles after calcination, which improves the electrical conductivity. The resultant LiFePO 4 /C with 1.1 wt.% carbon achieves a higher discharge capacity than those of LiFePO 4 and LiFePO 4 /C prepared with inorganic NH 4 H 2 PO 4 . Moreover, core-shell structured LiFePO 4 /C nanocomposites are also fabricated by further introducing sucrose into the synthesis system. The high-quality carbon shell effectively hinders the LiFePO 4 particle growth and aggregation under high-temperature treatment, which further enhances the electrical conductivity and lithium-ion diffusion, resulting in the improved electrochemical performance with excellent cycle stability (the optimum discharge capacity of 158.6 mAh g −1 at 0.1 C and 138.4 mAh g −1 at 2 C). The high

  12. Co3(PO4)2·4H2O

    Science.gov (United States)

    Lee, Young Hoon; Clegg, Jack K.; Lindoy, Leonard F.; Lu, G. Q. Max; Park, Yu-Chul; Kim, Yang

    2008-01-01

    Single crystals of Co3(PO4)2·4H2O, tricobalt(II) bis­[ortho­phosphate(V)] tetra­hydrate, were obtained under hydro­thermal conditions. The title compound is isotypic with its zinc analogue Zn3(PO4)2·4H2O (mineral name hopeite) and contains two independent Co2+ cations. One Co2+ cation exhibits a slightly distorted tetra­hedral coordination, while the second, located on a mirror plane, has a distorted octa­hedral coordination environment. The tetra­hedrally coordinated Co2+ is bonded to four O atoms of four PO4 3− anions, whereas the six-coordinate Co2+ is cis-bonded to two phosphate groups and to four O atoms of four water mol­ecules (two of which are located on mirror planes), forming a framework structure. In addition, hydrogen bonds of the type O—H⋯O are present throughout the crystal structure. PMID:21200978

  13. Preparation and characterization of SnO2 and Carbon Co-coated LiFePO4 cathode materials.

    Science.gov (United States)

    Wang, Haibin; Liu, Shuxin; Huang, Yongmao

    2014-04-01

    The SnO2 and carbon co-coated LiFePO4 cathode materials were successfully synthesized by solid state method. The microstructure and morphology of LiFePO4 composites were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscope. The results showed that the SnO2 and carbon co-coated LiFePO4 cathode materials exhibited more uniform particle size distribution. Compared with the uncoated LiFePO4/C, the structure of LiFePO4 with SnO2 and carbon coating had no change. The existence of SnO2 and carbon coating layer effectively enhanced the initial discharge capacity. Among the investigated samples, the one with DBTDL:LiFePO4 molar ratios of 7:100 exhibited the best electrochemical performance.

  14. Synthesis and crystal structure of acid indium phosphite In(H3PO3)3

    International Nuclear Information System (INIS)

    Zakharova, B.S.; Chudinova, N.N.; Ilyhkhin, A.B.

    1996-01-01

    A group of isostructural acid phosphites of trivalent metals M(H 2 PO 3 ) 3 , where M 3 =V, Fe, Ga, In, was synthesized. Crystal structure of In(H 2 PO 3 ) 3 was determined. The compound crystallizes in hexagonal syngony, a = 8.414(2), c = 7.069(2) A, V = 433.3(2) A 3 , Z = 2, sp.gr. P6 3 . In (H 2 PO 3 ) 3 structure is of frame type. 9 refs.; 3 tabs

  15. Crystal structure of Na3Sc2(PO4)3 at 60 deg C

    International Nuclear Information System (INIS)

    Lazoryak, B.I.; Kalinin, V.B.; Stefanovich, S.Yu.; Efremov, V.A.

    1980-01-01

    The structure of the ferroelectric phase of Na 3 Sc 2 (PO 4 ) 3 compound was studied. Na 3 Sc 2 (PO 4 ) 3 monocrystal heated by a jet of warm N 2 was investigated at 60 deg C. The rhombohedron modification was determined: a=8.927(3), c=22.34(4) A, Z=6, space group R anti 3c. Interatomic distances and inner angles of polyhedrons in Na 3 Sc 2 (PO 4 ) 3 structure were determined

  16. The low lying yrast structure of 212Po

    International Nuclear Information System (INIS)

    Poletti, A.R.; Dracoulis, G.D.; Byrne, A.P.; Stuchbery, A.E.

    1987-07-01

    The properties of states in 212 Po populated by the 208 Pb( 9 Be,αn) 212 Po reaction have been investigated. the previously proposed yrast scheme below 3MeV has been verified and eight further transitions placed in the level scheme. Mean lives of the 6 + , 8 + and (10 + ) states at 1355, 1476 and 1834 keV have been measured as 1.1(3), 24.6(3) and 0.8(2)ns respectively. Shell model calculations using effective interactions were used to interpret the observed scheme. A synthesis of all available theoretical and experimental evidence allows the 65s isomer to be identified clearly as the 18 + level arising primarily from the π(h 9/2 2 )*ν(g 9/2 i 11/2 ) configuration

  17. Technologically enhanced 210Pb and 210Po in iron and steel industry

    International Nuclear Information System (INIS)

    Khater, Ashraf E.M.; Bakr, Wafaa F.

    2011-01-01

    Iron and steel manufacture has been ranked as the largest industrial source of environmental contamination in the USA; the wastes generated in their production processes contain heavy elements that can be a source of contamination, and natural radionuclides that can produce an occupational and/or public radiological impact. In this work the potential occupational effective dose rate (μSv/y) due to inhalation in four integrated steel-making factories from Egypt has been evaluated, by assuming a well defined scenario and with basis in the 210 Pb and 210 Po activity concentrations determined in ore and wastes collected in the aforementioned factories. Activity concentrations, in Bq/kg, of 210 Pb and 210 Po, and leachable Pb and Fe were measured using gamma-ray spectrometry based on HPGe detector, alpha particle spectrometry based on PIPS detector, and inductively coupled plasma-mass spectrometry (ICP-MS). Levels of 210 Pb and 210 Po in the range of 210 Pb and 210 Po radionuclides. → Both radionuclides are enriched through the thermal processes. → For radiation dose assessment inhalation would be the main route of exposure.

  18. LiFePO4/polymer/natural graphite: low cost Li-ion batteries

    International Nuclear Information System (INIS)

    Zaghib, K.; Striebel, K.; Guerfi, A.; Shim, J.; Armand, M.; Gauthier, M

    2004-01-01

    The aging and performance of natural graphite/PEO-based gel electrolyte/LiFePO 4 cells are reported. The gel polymer electrolytes were produced by electron-beam irradiation and then soaked in a liquid electrolyte. The natural graphite anode in gel electrolyte containing LiBF4-EC/GBL exhibited high reversible capacity (345 mAh/g) and high coulombic efficiency (91%). The LiFePO 4 cathode in the same gel-polymer exhibited a reversible capacity of 160 mAh/g and 93% coulombic efficiency. Better performance was obtained at high-rate discharge with 6% carbon additive in the cathode, however the graphite anode performance suffers at high rate. The Li-ion gel polymer battery shows a capacity fade of 13% after 180 cycles and has poor performance at low temperature due to low diffusion of the lithium to the graphite in the GBL system. The LiFePO 4 /gel/Li system has an excellent rate capacity. LiFePO 4 cathode material is suitable for HEV application

  19. Biocarbon-coated LiFePO4 nucleus nanoparticles enhancing electrochemical performances

    DEFF Research Database (Denmark)

    Zhang, X.G.; Zhang, X.D.; He, W.

    2012-01-01

    We report a green biomimetic method to synthesize biocarbon-coated LiFePO4 nucleus nanoparticles using yeast cells as both a structural template and a biocarbon source for high-power lithium-ion batteries.......We report a green biomimetic method to synthesize biocarbon-coated LiFePO4 nucleus nanoparticles using yeast cells as both a structural template and a biocarbon source for high-power lithium-ion batteries....

  20. pO2 Fluctuation Pattern and Cycling Hypoxia in Human Cervical Carcinoma and Melanoma Xenografts

    International Nuclear Information System (INIS)

    Ellingsen, Christine; Øvrebø, Kirsti Marie; Galappathi, Kanthi; Mathiesen, Berit; Rofstad, Einar K.

    2012-01-01

    Purpose: Blood perfusion in tumors is spatially and temporally heterogeneous, resulting in local fluctuations in tissue oxygen tension (pO 2 ) and tissue regions showing cycling hypoxia. In this study, we investigated whether the pO 2 fluctuation pattern and the extent of cycling hypoxia differ between tumor types showing high (e.g., cervical carcinoma xenograft) and low (e.g., melanoma xenograft) fractions of connective tissue-associated blood vessels. Methods and Materials: Two cervical carcinoma lines (CK-160 and TS-415) and two melanoma lines (A-07 and R-18) transplanted into BALB/c nu/nu mice were included in the study. Tissue pO 2 was measured simultaneously in two positions in each tumor by using a two-channel OxyLite fiber-optic oxygen-sensing device. The extent of acute and chronic hypoxia was assessed by combining a radiobiological and a pimonidazole-based immunohistochemical assay of tumor hypoxia. Results: The proportion of tumor regions showing pO 2 fluctuations, the pO 2 fluctuation frequency in these regions, and the relative amplitude of the pO 2 fluctuations were significantly higher in the melanoma xenografts than in the cervical carcinoma xenografts. Cervical carcinoma and melanoma xenografts did not differ significantly in the fraction of acutely hypoxic cells or the fraction of chronically hypoxic cells. However, the ratio between fraction of acutely hypoxic cells and fraction of chronically hypoxic cells was significantly higher in melanoma than in cervical carcinoma xenografts. Conclusions: Temporal heterogeneity in blood flow and tissue pO 2 in tumors may depend on tumor histology. Connective tissue surrounding microvessels may stabilize blood flow and pO 2 and, thus, protect tumor tissue from cycling hypoxia.

  1. Photoluminescence and thermoluminescence properties of Tb3+ doped K3Gd(PO4)2 nanophosphor

    International Nuclear Information System (INIS)

    Gupta, Palvi; Bedyal, A.K.; Kumar, Vinay; Khajuria, Y.; Lochab, S.P.; Pitale, S.S.; Ntwaeaborwa, O.M.; Swart, H.C.

    2014-01-01

    Energy level diagram of Tb 3+ ion in the K 3 Gd(PO 4 ) 2 host lattice. - Highlights: • First time, a detailed TL and PL study on undoped and Tb 3+ doped K 3 Gd(PO 4 ) 2 nanophosphor. • Combustion method was employed to synthesize the Tb 3+ doped K 3 Gd(PO 4 ) 2 nanophosphor. • Mechanism of excitation and emission in undoped and Tb 3+ doped K 3 Gd(PO 4 ) 2 nanophosphor was given. - Abstract: Tb 3+ doped nanoparticulate K 3 Gd(PO 4 ) 2 phosphor was prepared by combustion method using urea as a fuel. The structure, optical and luminescent properties of the phosphor were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), and thermoluminescence (TL) spectroscopy. In undoped K 3 Gd(PO 4 ) 2 , the excitation and emission peaks at 273 nm and 323 nm belongs to the 8 S 7/2 → 6 I J(J=7/2) and 6 P J(J=7/2) → 8 S 7/2 transitions of Gd 3+ while green emission was observed in the Tb 3+ doped K 3 Gd(PO 4 ) 2 . TL study was carried out after exposing the samples to γ-radiations (0.1–5 kGy) in the K 3 Gd(PO 4 ) 2 :Tb 3+ (1.5 mol%). The calculated kinetic parameters were compared with different methods. The band gap of the phosphor was estimated as 5.80 eV. The green shade of the Tb 3+ ion with the CIE coordinates (x, y) as (0.29, 0.54) was in good agreement with the well known green phosphors

  2. Levels and transfer of 210Po and 210Pb in Nordic terrestrial ecosystems

    DEFF Research Database (Denmark)

    Brown, J.E.; Gjelsvik, R.; Roos, Per

    2011-01-01

    concentrations of the main dose forming radionuclides 210Po and 210Pb in biota from terrestrial ecosystems thus providing insight into the behaviour of these radioisotopes. Samples of soil, plants and animals were collected at Dovrefjell, Central Norway and Olkiluoto, Finland. Soil profiles from Dovrefjell...... exhibited an approximately exponential fall in 210Pb activity concentrations from elevated levels in humus/surface soils to “supported” levels at depth. Activity concentrations of 210Po in fauna (invertebrates, mammals, birds) ranged between 2 and 123 Bq kg−1 d.w. and in plants and lichens between 20...... and 138 Bq kg−1 d.w.. The results showed that soil humus is an important reservoir for 210Po and 210Pb and that fauna in close contact with this media may also exhibit elevated levels of 210Po. Concentration ratios appear to have limited applicability with regards to prediction of activity concentrations...

  3. Application of an in vitro digestion model for 210Po bioaccessibility assessment in seafood.

    Science.gov (United States)

    Roselli, Carla; Desideri, Donatella; Feduzi, Laura; Ugolini, Lucia; Meli, Maria Assunta

    2017-12-01

    This study aims to investigate the bioaccessibility of 210 Po in seafood and the impact of food preparation on this radionuclide. Polonium bioaccessibility is the fraction of 210 Po mobilised from food matrices into digestive extractants when applying an in vitro digestion model. The degree of bioaccessibility of 210 Po in food has important implications for estimating ingestion doses from this radionuclide. The simulation of gastrointestinal digestion was divided into three stages through the use of synthetic saliva, gastric and bile-pancreas solutions. Following pre-treatment with a saliva solution, raw and cooked seafood samples underwent one of the following treatments: (a) simulated gastric digestion only or (b) simulated complete gastrointestinal digestion (gastric digestion followed by bile-pancreas digestion). No significant difference (P > 0.05) in 210 Po mobility was found between samples that underwent gastric digestion compared to those that only underwent gastro-intestinal digestion. However, a significant difference (P 210 Po bioaccessibility was found between raw and cooked seafood undergoing both gastric and gastro-intestinal digestion.

  4. Preparation and Characterisation of LiFePO4/CNT Material for Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Rushanah Mohamed

    2011-01-01

    Full Text Available Li-ion battery cathode materials were synthesised via a mechanical activation and thermal treatment process and systematically studied. LiFePO4/CNT composite cathode materials were successfully prepared from LiFePO4 material. The synthesis technique involved growth of carbon nanotubes onto the LiFePO4 using a novel spray pyrolysis-modified CVD technique. The technique yielded LiFePO4/CNT composite cathode material displaying good electrochemical activity. The composite cathode exhibited excellent electrochemical performances with 163 mAh/g discharge capacity with 94% cycle efficiency at a 0.1 C discharge rate in the first cycle, with a capacity fade of approximately 10% after 30 cycles. The results indicate that carbon nanotube addition can enable LiFePO4 to display a higher discharge capacity at a fast rate with high efficiency. The research is of potential interest for the application of carbon nanotubes as a new conducting additive in cathode preparation and for the development of high-power Li-ion batteries for hybrid electric vehicles.

  5. Mechanistic insights of Li+ diffusion within doped LiFePO4 from Muon Spectroscopy.

    Science.gov (United States)

    Johnson, Ian D; Ashton, Thomas E; Blagovidova, Ekaterina; Smales, Glen J; Lübke, Mechthild; Baker, Peter J; Corr, Serena A; Darr, Jawwad A

    2018-03-07

    The Li + ion diffusion characteristics of V- and Nb-doped LiFePO 4 were examined with respect to undoped LiFePO 4 using muon spectroscopy (µSR) as a local probe. As little difference in diffusion coefficient between the pure and doped samples was observed, offering D Li values in the range 1.8-2.3 × 10 -10  cm 2 s -1 , this implied the improvement in electrochemical performance observed within doped LiFePO 4 was not a result of increased local Li + diffusion. This unexpected observation was made possible with the µSR technique, which can measure Li + self-diffusion within LiFePO 4 , and therefore negated the effect of the LiFePO 4 two-phase delithiation mechanism, which has previously prevented accurate Li + diffusion comparison between the doped and undoped materials. Therefore, the authors suggest that µSR is an excellent technique for analysing materials on a local scale to elucidate the effects of dopants on solid-state diffusion behaviour.

  6. Regulation of the activity of the promoter of RNA-induced silencing, C3PO.

    Science.gov (United States)

    Sahu, Shriya; Williams, Leo; Perez, Alberto; Philip, Finly; Caso, Giuseppe; Zurawsky, Walter; Scarlata, Suzanne

    2017-09-01

    RNA-induced silencing is a process which allows cells to regulate the synthesis of specific proteins. RNA silencing is promoted by the protein C3PO (component 3 of RISC). We have previously found that phospholipase Cβ, which increases intracellular calcium levels in response to specific G protein signals, inhibits C3PO activity towards certain genes. Understanding the parameters that control C3PO activity and which genes are impacted by G protein activation would help predict which genes are more vulnerable to downregulation. Here, using a library of 10 18 oligonucleotides, we show that C3PO binds oligonucleotides with structural specificity but little sequence specificity. Alternately, C3PO hydrolyzes oligonucleotides with a rate that is sensitive to substrate stability. Importantly, we find that oligonucleotides with higher Tm values are inhibited by bound PLCβ. This finding is supported by microarray analysis in cells over-expressing PLCβ1. Taken together, this study allows predictions of the genes whose post-transcriptional regulation is responsive to the G protein/phospholipase Cβ/calcium signaling pathway. © 2017 The Protein Society.

  7. 3.0 V High Energy Density Symmetric Sodium-Ion Battery: Na4V2(PO4)3∥Na3V2(PO4)3.

    Science.gov (United States)

    Yao, Xuhui; Zhu, Zixuan; Li, Qi; Wang, Xuanpeng; Xu, Xiaoming; Meng, Jiashen; Ren, Wenhao; Zhang, Xinhe; Huang, Yunhui; Mai, Liqiang

    2018-03-28

    Symmetric sodium-ion batteries (SIBs) are considered as promising candidates for large-scale energy storage owing to the simplified manufacture and wide abundance of sodium resources. However, most symmetric SIBs suffer from suppressed energy density. Here, a superior congeneric Na 4 V 2 (PO 4 ) 3 anode is synthesized via electrochemical preintercalation, and a high energy density symmetric SIB (Na 3 V 2 (PO 4 ) 3 as a cathode and Na 4 V 2 (PO 4 ) 3 as an anode) based on the deepened redox couple of V 4+ /V 2+ is built for the first time. When measured in half cell, both electrodes show stabilized electrochemical performance (over 3000 cycles). The symmetric SIBs exhibit an output voltage of 3.0 V and a cell-level energy density of 138 W h kg -1 . Furthermore, the sodium storage mechanism under the expanded measurement range of 0.01-3.9 V is disclosed through an in situ X-ray diffraction technique.

  8. Analysis of 210Pb and 210Po in Brazilian foods and diets

    International Nuclear Information System (INIS)

    Cunha, I.L.; Bueno, L.; Favaro, D.I.T.; Maihara, V.A.; Cozzollino, S.

    2001-01-01

    Radiochemical procedures for the analysis of 210 Pb and 210 Po in foods and diets are presented. Because of the low beta energy of 210 Pb, its analysis was based on a separation of the daughter radionuclide 210 Bi by precipitation of lead sulphate, 210 Bi ingrowing and beta counting of this nuclide. 210 Po analysis was based on wet dissolution of the sample, deposition onto silver disc and counting by alpha-spectrometry. Levels of these radionuclides in individual items and diets of selected university students were determined in order to evaluate the intakes of 210 Pb and 210 Po as well as the dose due to ingestion of foods and diets in Sao Paulo city. (author)

  9. Enhanced apatite formation on Ti metal heated in PO2-controlled nitrogen atmosphere.

    Science.gov (United States)

    Hashimoto, Masami; Hayashi, Kazumi; Kitaoka, Satoshi

    2013-10-01

    The oxynitridation of biomedical titanium metal under a precisely regulated oxygen partial pressure (PO2) of 10(-14)Pa in nitrogen atmosphere at 973 K for 1 h strongly enhanced apatite formation compared with that on Ti heated in air. The factors governing the high apatite-forming ability are discussed from the viewpoint of the surface properties of Ti heated under a PO2 of 10(-14)Pa in nitrogen atmosphere determined from X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and zeta potential measurements. Nitrogen (N)-doped TiO2 (interstitial N) was formed on pure Ti heated under a PO2 of 10(-14)Pa in nitrogen atmosphere at 973 K. The XPS O1s main peak shifted toward a lower binding energy upon heating under a PO2 of 10(-14)Pa. This shift may be due to the formation of oxygen vacancies. This Ti surface had a positive zeta potential of approximately 20 mV. According to time-of-flight secondary ion mass spectroscopy results, PO4(3-) ions were predominantly adsorbed on Ti soaked in simulated body fluid (SBF) after heat treatment, followed by calcium ions. It was concluded that the apatite formation kinetics can be described using the Avrami-Erofeev equation with an Avrami index of n=2, which implies the instantaneous nucleation of apatite on the surface of Ti soaked in SBF after heat treatment at 973 K under a PO2 of 10(-14)Pa. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. BOLD quantified renal pO2 is sensitive to pharmacological challenges in rats.

    Science.gov (United States)

    Thacker, Jon; Zhang, Jeff L; Franklin, Tammy; Prasad, Pottumarthi

    2017-07-01

    Blood oxygen level-dependent (BOLD) MRI has been effectively used to monitor changes in renal oxygenation. However, R2* (or T2*) is not specific to blood oxygenation and is dependent on other factors. This study investigates the use of a statistical model that takes these factors into account and maps BOLD MRI measurements to blood pO2. Spin echo and gradient echo images were obtained in six Sprague-Dawley rats and R2 and R2* maps were computed. Measurements were made at baseline, post-nitric oxide synthase inhibitor (L-NAME), and post-furosemide administration. A simulation of each region was performed to map R2' (computed as R2*-R2) to blood pO2. At baseline, blood pO2 in the outer medulla was 30.5 ± 1.2 mmHg and 51.9 ± 5.2 mmHg in the cortex, in agreement with previous invasive studies. Blood pO2 was found to decrease within the outer medulla following L-NAME (P pO2 in the cortex increased following furosemide (P pO2 is sensitive to pharmacological challenges, and baseline pO2 is comparable to literature values. Reporting pO2 instead of R2* could lead to a greater clinical impact of renal BOLD MRI and facilitate the identification of hypoxic regions. Magn Reson Med 78:297-302, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  11. LiFePO4 nanoparticles encapsulated in graphene nanoshells for high-performance lithium-ion battery cathodes.

    Science.gov (United States)

    Fei, Huilong; Peng, Zhiwei; Yang, Yang; Li, Lei; Raji, Abdul-Rahman O; Samuel, Errol L G; Tour, James M

    2014-07-11

    LiFePO4 encapsulated in graphene nanoshells (LiFePO4@GNS) nanoparticles were synthesized by solid state reaction between graphene-coated Fe nanoparticles and LiH2PO4. The resulting nanocomposite was demonstrated to be a superior lithium-ion battery cathode with improved cycle and rate performances.

  12. Effects of titanium incorporation on phase and electrochemical performance in LiFePO4 cathode material

    International Nuclear Information System (INIS)

    Wang Zhaohui; Pang Quanquan; Deng Kejian; Yuan Lixia; Huang Fei; Peng Yunlong; Huang Yunhui

    2012-01-01

    Highlights: ► Nominal LiFe 1−x Ti x PO 4 cathode materials were synthesized via solid-state reaction. ► A clear feature of Ti-doped LiFePO 4 has been clarified. ► The formation of impurity phases strongly depends on Ti doping level. ► Appropriate amount of Ti in LiFePO 4 can enhance the electrochemical performance. - Abstract: Ti-incorporated LiFe 1−x Ti x PO 4 (0 ≤ x ≤ 0.2) samples have been prepared via a two-step solid-state reaction route. The samples have systematically been investigated with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM), cyclic voltammetry (CV) and charge/discharge measurements. The incorporation of Ti in LiFePO 4 significantly enhances the electrochemical performance; the carbon-coated LiFe 0.9 Ti 0.1 PO 4 sample shows the best performance. It is confirmed that LiFe 1−x Ti x PO 4 with x ≤ 0.05 are of single phase while those with 0.07 ≤ x ≤ 0.2 contain impurity phases: LiTi 2 (PO 4 ) 3 and TiP 2 O 7 . The impurities influence not only the electronic conductivity, but also the total specific capacity. Appropriate amount of titanium incorporation is favorable for the improvement in electrochemical performance.

  13. 210Pb and 210Po Determination in Bottled Water Available on the Croatian Market

    International Nuclear Information System (INIS)

    Rogic, M.; Rozmaric Macefat, M.; Benedik, Lj.; Strok, M.

    2011-01-01

    An alpha emitting radionuclide 210Po and beta emitting radionuclide 210Pb are decay products of 238U. Due to their nuclear properties they are considered as radionuclides with the highest radiotoxicity and contribute significantly to the internal dose to the population received by drinking water. For radiological impact assessment 210Pb and 210Po must be measured routinely and accurately, with low detection limits. The aim of our study was determination of activity concentrations of 210Pb and 210Po in bottled drinking and mineral waters available on Croatian market. For their determination a procedure for their simultaneous separation from the water samples was used. After addition of 209Po tracer and lead carrier, radionuclides were preconcentrated from large volume by MnO 2 and their separation from interfering elements by Sr resin was done. 210Po source for alpha-particle spectrometric measurement was prepared by selfdeposition on silver disc, while lead was precipitated as lead sulphate and the beta activity of its daughter 210Bi was counted on a beta proportional counter. The results obtained show that values for activity concentrations of 210Pb and 210Po in all examined waters are in accordance with allowed activity concentration according to the European Commission Recommendation 2001/928/Euratom and Guidelines for Drinking Water Quality, published by WHO in 2006. (author)

  14. Comparative study of scintillation properties of RE doped NaPO3-Al(PO3)3 glasses

    International Nuclear Information System (INIS)

    Kuro, Tomoaki; Yanagida, Takayuki; Okada, Go; Fujimoto, Yutaka; Masai, Hirokazu

    2015-01-01

    We systematically investigated photoluminescence (PL), scintillation and dosimeter properties of rare-earth (RE) doped NaPO 3 -Al(PO 3 ) 3 (NAP) glasses. Ag-doped NAP glass is widely used for individual radiation dosimeter, however, there have been few reports on studies about NAP glasses when RE ions are doped as the luminescence center. The NAP glasses doped with 0.3 wt% RE (La∼Yb) were prepared by the conventional melt-quenching method. PL decay time and scintillation decay time profiles showed fast (ns) and slow (μs or ms) components: the fast components were from several tens to 100 ns due to the host emission or 5d-4f transition emission, and the slow component from few μs to few ms was caused by 4f-4f transition emission of RE 3+ . Thermally stimulated luminescence (TSL) was evaluated as a dosimeter property, and glow peaks appeared around 400degC in all the samples. The TSL dose response function was examined in the dose range from 10 mGy to 10 Gy, and good linearity was observed in RE-doped NAP glasses. (author)

  15. Preservation of intestinal microvascular Po2 during normovolemic hemodilution in a rat model

    NARCIS (Netherlands)

    van Bommel, J.; Siegemund, M.; Henny, C. P.; van den Heuvel, D. A.; Trouwborst, A.; Ince, C.

    2000-01-01

    The effect of hemodilution on the intestinal microcirculatory oxygenation is not clear. The aim of this study was to determine the effect of moderate normovolemic hemodilution on intestinal microvascular partial oxygen pressure (Po2) and its relation to the mesenteric venous Po2 (Pmvo2).

  16. Unusual {sup 210}Po/{sup 210}Pb ratios in the surface water of the Gulf of Lions; Rapports {sup 210}Po/{sup 210}Pb inhabituels dans l`eau superficielle du golfe du Lion

    Energy Technology Data Exchange (ETDEWEB)

    Radakovitch, O.; Heussner, S. [Universite de Perpignan, 66 (France). Laboratoire de Sedimentologie et Geochimie Marines]|[Cerege, Europole de l`Arbois, 13 - Aix-en-Provence (France); Cherry, R.D.; Heyraud, M. [Cape Town Univ. (South Africa). Dept. of Physics

    1998-05-01

    Concentrations of {sup 210}Po and {sup 210}Pb have been measured in sea water collected in the Grand Rhone Canyon. Concentrations of {sup 210}Pb are at similar levels to those found in other Mediterranean sea water samples, and are at the levels which would be expected in comparison with global sea water data. The same applies to the {sup 210}Po concentrations in samples from below 100 m depth. Surface samples from above 100 m have {sup 210}Po at levels rather higher than expected, and their {sup 210}Po/{sup 210}Pb ratios are about 1 or more as compared with the usual open ocean ratio 0.5. These data can be interpreted as indicating another source of supply of {sup 210}Po to the surface layer in addition to the normal atmospheric input. We suggest that an episodic advective particulate input, probably originating in the output of the Rhone river and perhaps involving resuspension of fine particulates from the bottom sediments as a result of storm conditions, is he most likely candidate for this additional source. (authors) 47 refs.

  17. Synthesis of surface oxygen-deficient BiPO{sub 4} nanocubes with enhanced visible light induced photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Bingtao; Yin, Haoyong; Li, Tao; Gong, Jianying; Lv, Shumei; Nie, Qiulin, E-mail: yhy@hdu.edu.cn [College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou (China)

    2017-05-15

    The visible light driven BiPO{sub 4} nanocubes with sufficient surface oxygen deficiency were fabricated by a hydrothermal process and subsequently ultrasonic assistant Fe reduction process. The products were characterized by XRD, DRS, XPS, SEM and TEM which showed that the BiPO{sub 4} had cuboid-like shape with a smooth surface and clear edges and the oxygen vacancies were successfully introduced on the surface of the BiPO{sub 4} nanocubes. The as prepared oxygen-deficient BiPO{sub 4} nanocubes showed greatly enhanced visible light induced photocatalytic activity in degradation of Rhodamine B. The enhanced photocatalytic performance and expanded visible light response of BiPO{sub 4} may be due to the introduction of surface oxygen vacancies which can generate the oxygen vacancies mid-gap states lower to the conduction band of BiPO{sub 4}. (author)

  18. A new determination of the 209Po half-life

    International Nuclear Information System (INIS)

    Collé, R; Fitzgerald, R P; Laureano–Perez, L

    2014-01-01

    A substantial 25% error in the then-known and accepted (102 ± 5) year half-life of 209 Po was reported on in 2007. This error was detected from decay data from two separate primary standardizations of a 209 Po solution standard, which were performed approximately 12 years apart. Despite author claims that this observation was not a new half-life determination, it was nevertheless included in subsequent nuclear data evaluations and compilations to obtain a currently tabulated value of (115 ± 13) a, computed from the median and range of the two half-life reports. A third primary standardization on the identical 209 Po solution has since been performed to derive a new half-life value of (125.2 ± 3.3) a. This half-life determination was obtained from 30 distinct data sets over a period of 20.7 years, encompassing over 700 liquid scintillation measurements with nearly 50 counting sources all prepared from the same solution, and as obtained over a very broad range of measurement conditions (composition of cocktails, characteristics of counters, time sequencing) during five periods in 1993, 1994, 2005, and 2013. (paper)

  19. Alpha-particle and electron capture decay of 209Po

    International Nuclear Information System (INIS)

    Schima, F.J.; Colle, R.

    1996-01-01

    Gamma-ray and Kα X-ray emissions have been measured from a very pure 209 Po source containing less than 0.13% 208 Po activity and no detectable 210 Po (≤2 x 10 -4 %). The alpha-particle emission rate for this source has previously been determined. Data are presented that confirm alpha decay to the 205 Pb excited level at 262.8 keV, with an alpha-particle emission probability (±standard uncertainty) of 0.00559±0.00008. The ratio of K-shell electron capture to total electron capture for the second forbidden unique electron capture decay to the 896.6 keV level in 209 Bi was determined to be 0.594±0.018. The electron capture decay fraction was found to be 0.00454±0.00007, while the probabilities per decay for the 896.6, 262.8, and 260.5 keV gamma rays and the Bi Kα and Pb Kα X-rays were measured as 0.00445±0.00007, 0.00085±0.00002, 0.00254±0.00003, 0.00202±0.00005, and 0.00136±0.00005, respectively. (orig.)

  20. Adjustment and transformation strategies of ItalPoS Permanent GNSS Network

    Directory of Open Access Journals (Sweden)

    Alessandro Capra

    2009-06-01

    Full Text Available A private network of 133 Global Navigation Satellite Systems (GNSS permanent sites, named ItalPoS (Italian
    Positioning Service and uniformly covering the entire Italian territory, was established in April 2006 by the Italian
    Division of Leica Geosystems S.p.A. This network also involves several GPS stations of the INGV (Italian
    National Institute of Geophysics and Volcanology RING (Real-time Integrated National Gps network and GPS
    stations from other public and private bodies. Indeed Leica Geosystems contributed with its experience and its
    products to these networks which currently fulfil the national coverage where there are no ItalPoS stations. For
    instance, the purpose of the ItalPoS network is mainly GNSS data distribution in terms of real time corrections
    and RINEX files for the post-processing.
    In order to compute and distribute to private and scientific users a set of adjusted coordinates of the ItalPoS network
    in the IGS05 and ETRF89-2000 reference frames, a dataset of RINEX of about 120 GPS permanent sites
    was created and processed, using the distributed sessions approach, by means of Gamit/Globk 10.3 GPS data
    processor, also using some SOPAC (Scripps Orbits and Permanent Array Center and EUREF (European Permanent
    Network solutions to improve the reference frame definition and the internal constraints.
    This paper describes all the strategies adopted to estimate coordinates and velocities of the ItalPoS Network in
    IGS05 and in ETRF89-2000 reference frames in the whole Italian territory.

  1. Metabolic balances of 210Pb and 210Po at natural levels

    International Nuclear Information System (INIS)

    Spencer, H.; Holtzman, R.B.; Kramer, L.; Ilcewicz, F.H.

    1977-01-01

    Metabolic balances of 210 Po and 210 Pb were determined under strictly controlled dietary conditions in adult males. The intakes of the two nuclides were due to the dietary contents of these radioisotopes, inhalation from the atmosphere, and smoking of cigarettes. No additional radioisotope was given. The mean dietary intake of 210 Pb was 1.25 pCi/day and of 210 Po, 1.63 pCi/day. The major pathway of excretion of both nuclides is via the gastrointestinal tract and the urinary excretion is much lower. The total excretions of 210 Pb and 210 Po were greater than the dietary intake and the overall balances were -0.28 and -0.16 pCi/day for the two nuclides, respectively, during a low calcium intake. The 210 Pb balances did not change significantly when the calcium intake was increased 7- to 10-fold except for one patient in whom the balance became more negative. The 210 Po balance was more negative during calcium intakes of 800 and 2200 mg than during a low calcium intake of 200 mg/day. The urinary and fecal excretions of the two radionuclides were not affected by the intake of sodium fluoride, while the diuretic compound Hydrodiuril appeared to decrease the fecal 210 Pb excretion

  2. Metabolic balances of 210Pb and 210Po at natural levels

    International Nuclear Information System (INIS)

    Spencer, H.; Holtzman, R.B.; Kramer, L.; Ilcewicz, F.H.

    1977-01-01

    Metabolic balances of 210 Po and 210 Pb were determined under strictly controlled dietary conditions in adult males. The intakes of the two nuclides were due to the dietary contents of these radioisotopes, inhalation from the atmosphere, and smoking of cigarettes. No additional radioisotope was given. The mean dietary intake of 210 Pb was 1.25 pCi/day and of 210 Po, 1.63 pCi/day. The major pathway of excretion of both nuclides is via the gastrointestinal tract; the urinary excretion is much lower. The total excretions of 210 Pb and 210 Po were greater than the dietary intake and the overall balances were -0.28 and -0.16 pCi/day for the two nuclides, respectively, during a low calcium intake. The 210 Pb balances did not change significantly when the calcium intake was increased 7- to 10-fold except for one patient in whom the balance became more negative. The 210 Po balance was more negative during calcium intakes of 800 and 2200 mg than during a low calcium intake of 200 mg/day. The urinary and fecal excretions of the two radionuclides were not affected by the intake of sodium fluoride, while the diuretic compound, Hydrodiuril, appeared to decrease the fecal 210 Pb excretion

  3. Contemporary young users to retrain the wetlands and industrial/port archeology of Boretto Po

    OpenAIRE

    Visentin, Chiara

    2010-01-01

    Repopulate a place means helping the existing inhabitants to stop the slow decline and forgetfulness of his past. The instance of Boretto Po is emblematic. Boretto, along with Brescello, Gualtieri, Guastalla and Luzzara, is part of five urban areas of Reggio Emilia district, at the site of the middle Po river, between the exit of the Enza and the Oglio. The close coexistence of the inhabitants of Boretto with Po has seen a series of crafts and activities now completely abandone...

  4. Geochemical behavior of 210Pb and 210Po in the nearshore waters off western Taiwan

    International Nuclear Information System (INIS)

    Wei, Ching-Ling; Lin, Shiao-Yu; Wen, Liang-Saw; Sheu, David D.-D.

    2012-01-01

    Highlights: ► 210 Pb and 210 Po in the nearshore waters were determined off western coast of Taiwan. ► Partitioning of the radionuclides in turbid waters was discussed. ► Removal flux of particulate organic carbon was quantified using 210 Po proxy. - Abstract: Dissolved and particulate 210 Pb and 210 Po were determined at 15 stations along the coastline off western Taiwan in April 2007. The 210 Pb activities in dissolved and particulate phases fell within a relatively small range of 2.4–5.2 dpm 100 L −1 and 1.0–3.2 dpm 100 L −1 , respectively. The dissolved and particulate 210 Po activities also fell within a small range of 0.8–3.4 dpm 100 L −1 and 1.1–2.9 dpm 100 L −1 , respectively. The correlation of the distribution coefficients (K d ) of 210 Pb and 210 Po with particle concentration in turbid waters are not as evident as in the open ocean. The mass balance calculation shows that the residence times of 210 Pb and 210 Po with respect to particle removal from the nearshore waters ranges from 3 to 15 days and from 14 to 125 days, respectively. The flux of particulate organic carbon was estimated by 210 Po proxy and ranged from 4.8 to 33.7 mmol-C m −2 d −1 .

  5. Determination of 210Po in Slovak mineral waters by sorption on ZnS(Ag)

    International Nuclear Information System (INIS)

    Krivosik, M.

    2009-01-01

    In determining of 210 Po it was followed according to the Czech technical standard CSN 75 7626 Water quality - Determination of polonium-210. The aim of this work was to optimize the conditions for sorption of 210 Po on ZnS (Ag) from acidic environment from the model solutions. The effect of pH of the sample, its volume and the presence of NaCl on the sorption of 210 Po on ZnS (Ag) was studied. Three types of filters for filtering ZnS (Ag), Synpor, paper and glass fiber filters were tested. Bulk activity of 210 Po was determined in the samples of Slovak mineral waters and healing waters as well as in water samples from antimony mine (mine Rufus) near the village Poproc (rural Kosice district). (author)

  6. Effect of synthesis methods on luminescence properties of LiCaPO{sub 4}:Ce phosphor for radiation dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Palan, C.B., E-mail: chetupalan@rediffmail.com; Omanwar, S.K.

    2016-10-15

    The polycrystalline doped and un-doped LiCaPO{sub 4} phosphors were successfully prepared via solid state diffusion [SSD] and sol–gel [SG] methods. The sol–gel method was implied to decrease the processing time and heating temperature. The prepared un-doped and doped LiCaPO{sub 4} phosphors were characterized through X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Additionally photoluminescence (PL), thermoluminescence (TL) and optically stimulated luminescence (OSL) properties were studied. The XRD patterns of prepared LiCaPO{sub 4} and LiCaPO{sub 4}:Ce phosphors were well matched with the ICDD file. The average particles size of LiCaPO{sub 4} and LiCaPO{sub 4}:Ce phosphors were found to be in the range 2–10 μm by SSD method and 2-5 μm by SG method. The excitation spectra of LiCaPO{sub 4} and LiCaPO{sub 4}:Ce phosphors consist of broad band in the range 200–330 nm and maximum intensity was observed at 314 nm. Also emission spectra consist of broad band in range from 330–500 nm and maximum intensity was observed at 369 nm. With the increase of Ce{sup 3+} ions concentration, the emission spectra of LiCaPO{sub 4}:Ce{sup 3+} phosphors shifted to a longer wavelength. The prepared phosphors were showed excellent TL properties under β irradiation. The OSL sensitivity of the LiCaPO{sub 4}:Ce phosphor synthesized by the SSD method was the nearly same as compared with the OSL sensitivity of LiCaPO{sub 4}:Ce phosphor synthesized by the SG method.

  7. PoD: dynamically create and use remote PROOF clusters. A thin client concept.

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    PoD’s newly developed “pod-remote” command made it possible for users to utilize a thin client concept. In order to create dynamic PROOF clusters, users are now able to select a remote computer, even behind a firewall, to control a PoD server on...

  8. Urea-assisted synthesis of AlPO4:Ce,Tb nanorods as a redox luminescence switch

    International Nuclear Information System (INIS)

    Yang, Wei; Hu, Juncheng

    2013-01-01

    AlPO 4 :Ce,Tb nanorods were synthesized by a facile hydrothermal method. The morphology of rod-like AlPO 4 was tuned by varying urea concentrations, AlPO 4 gradually changed from nanosheets to nanorods, and urea provided hydroxyl anion (OH − ) in the aqueous solution to prepare the dispersed nanorods under the hydrothermal conditions. The emission intensity of nanorods increased significantly compared to that of nanosheets. AlPO 4 :Ce,Tb nanorods provided a novel redox luminescence switch on the basis of the reversible switching of the Ce 3+ /Ce 4+ redox couple. The luminescence is quenched (off) when the system is in the oxidized form while it is restored (on) in the reduced form. The mechanism of the energy transfer and electronic transition between Ce 3+ and Tb 3+ in the AlPO 4 nanorods was also discussed. This switch has biocompatibility and low toxicity, and may have a potential application in biomedical diagnostics and analysis

  9. Photocatalytic activity of Ag3PO4 nanoparticle/TiO2 nanobelt heterostructures

    Science.gov (United States)

    Liu, Ruoyu; Hu, Peiguang; Chen, Shaowei

    2012-10-01

    Heterostructures based on Ag3PO4 nanoparticles and TiO2 nanobelts were prepared by a coprecipitation method. The crystalline structures were characterized by X-ray diffraction measurements. Electron microscopic studies showed that the Ag3PO4 nanoparticles and TiO2 nanobelts were in intimate contact which might be exploited to facilitate charge transfer between the two semiconductor materials. In fact, the heterostructures exhibited markedly enhanced photocatalytic activity as compared with unmodified TiO2 nanobelts or commercial TiO2 colloids in the photodegradation of methyl orange under UV irradiation. This was accounted for by the improved efficiency of interfacial charge separation thanks to the unique alignments of their band structures. Remarkably, whereas the photocatalytic activity of the heterostructure was comparable to that of Ag3PO4 nanoparticles alone, the heterostructures exhibited significantly better stability and reusability in repeated tests than the Ag3PO4 nanoparticles.

  10. Increase of {sup 210}Po levels in human semen fluid after mussel ingestion

    Energy Technology Data Exchange (ETDEWEB)

    Kelecom, Alphonse, E-mail: lararapls@hotmail.co [Laboratory of Radiobiology and Radiometry-LARARA-PLS, Universidade Federal Fluminense, P.O.Box 100.436, 24001-970 Niteroi, RJ (Brazil); Programs in Environmental Science and Marine Biology, Universidade Federal Fluminense, Niteroi, RJ (Brazil); Gouvea, Rita de Cassia dos Santos [Laboratory of Radiobiology and Radiometry-LARARA-PLS, Universidade Federal Fluminense, P.O.Box 100.436, 24001-970 Niteroi, RJ (Brazil)

    2011-05-15

    Polonium-210 ({sup 210}Po) radioactive concentrations were determined in human semen fluid of vasectomized non-smoker volunteers. The {sup 210}Po levels ranged from 0.10 to 0.39 mBq g{sup -1} (mean: 0.23 {+-} 0.08 mBq g{sup -1}). This value decreased to 0.10 {+-} 0.02 mBq g{sup -1} (range from 0.07 to 0.13 mBq g{sup -1}) after two weeks of a controlled diet, excluding fish and seafood. Then, volunteers ate during a single meal 200 g of the cooked mussel Perna perna L., and {sup 210}Po levels were determined again, during ten days, in semen fluid samples collected every morning. Volunteers continued with the controlled diet and maintained sexual abstinence through the period of the experiment. A 300% increase of {sup 210}Po level was observed the day following mussel consumption, with a later reduction, such that the level returned to near baseline by day 4.

  11. Synthesis of LiFePO4/C cathode material from ferric oxide and organic lithium salts

    International Nuclear Information System (INIS)

    Shi Zhongqi; Huang Ming; Huai Yongjian; Lin Ziji; Yang Kerun; Hu Xuebu; Deng Zhenghua

    2011-01-01

    Research highlights: → LiFePO 4 can be synthesized from Fe 2 O 3 by a sequence of free-radical reactions. → Organic lithium salts can avoid the composition segregation of the precursor. → Low cost ferric oxide and environmentally friendly distilled water are used. - Abstract: LiFePO 4 /C cathode material has been simply synthesized via a modified in situ solid-state reaction route using the raw materials of Fe 2 O 3 , NH 4 H 2 PO 4 , Li 2 C 2 O 4 and lithium polyacrylate (PAALi). The sintering temperature of LiFePO 4 /C precursor is studied by thermo-gravimetric (TG)/differential thermal analysis (DTA). The physical properties of LiFePO 4 /C are then investigated through analysis using by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and the electrochemical properties are investigated by electrochemical impedance spectra (EIS), cyclic voltammogram (CV) and constant current charge/discharge test. The LiFePO 4 /C composite with the particle size of ∼200 nm shows better discharge capacity (156.4 mAh g -1 ) than bare LiFePO 4 (52.3 mAh g -1 ) at 0.2 C due to the improved electronic conductivity which is demonstrated by EIS. The as-prepared LiFePO 4 /C through this method also shows excellent high-rate characteristic and cycle performance. The initial discharge capacity of the sample is 120.5 mAh g -1 and the capacity retention rate is 100.6% after 50 cycles at 5 C rate. The results prove that the using of organic lithium salts can obtain a high performance LiFePO 4 /C composite.

  12. A review of the Delta Po evolution (Italy) related to climatic changes and human impacts

    Science.gov (United States)

    Simeoni, Umberto; Corbau, Corinne

    2009-06-01

    Climate changes and sea-level rise are important issues, especially for deltas such as the Po Delta, Italy. The evolution of the Po Delta shows a succession in space and a superposition in time of complex environmental natural processes. During the last few centuries, anthropogenic action has played a major role. The formation of the Po Delta began about 2000 years ago and has undergone many phases of development. Between 1500 AD and 1600 AD, the Venetian technicians diverted the Po river course. With these interventions, the "Renaissance delta" was cut off from the hydraulic network and the "modern delta" began to form. Until the middle of the 20th century, progradation of the delta was noticeable due to the abundant sediment supply. In the following decades coastal erosion occurred, this was caused by the reduction of the solid supply of the Po, due to dam and barrier construction and to river bed excavation. These and other interventions (e.g. reclamation, methane extractions from superficial ground water table) have deeply modified the physical and ecological characteristics of the Po Delta. The morphological characteristics of the Po Delta make the largest Italian wetland particularly unstable and very fragile when subjected to human pressure. Furthermore, the delta evidences multiple threats that will probably be exacerbated in the following decades by the effects of expected climatic changes. Only the application of careful policies concerning coastal defence, flood mitigation, anthropogenic subsidence reduction and salt wedge intrusion control will allow reduction of the present or predicted negative effects. This paper reviews how natural and human factors have controlled the Po Delta through time and discusses management strategies taking into account the importance of the human factor and the potential effects of climatic changes.

  13. Synthesis and luminescence properties of novel LiSrPO{sub 4}:Dy{sup 3+} phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jiayue, E-mail: jiayue_sun@126.com [School of Science, Beijing Technology and Business University, Beijing 100048 (China); Zhang, Xiangyan [School of Science, Beijing Technology and Business University, Beijing 100048 (China); Xia, Zhiguo, E-mail: xiazg426@yahoo.com.cn [School of Materials Sciences and Technology, China University of Geosciences, Beijing 100083 (China); Du, Haiyan [School of Science, Beijing Technology and Business University, Beijing 100048 (China)

    2011-11-15

    Graphical abstract: Novel LiSrPO4:Dy{sup 3+} phosphors were synthesized by solid-state reaction, and Dy{sup 3+}-doped concentration dependent luminescence properties, concentration quenching effect and the decay times were investigated in detail. Highlights: {yields} LiSrPO{sub 4}:Dy{sup 3+} could be excited by UV light and exhibited blue and yellow emission. {yields} Concentration quenching effect of LiSrPO{sub 4}:Dy{sup 3+} samples were investigated in detail. {yields} Decay times are estimated to be 0.57-0.89 ms for Dy{sup 3+} in LiSrPO{sub 4} host. -- Abstract: Novel LiSrPO{sub 4}:Dy{sup 3+} phosphors for white light-emitting diodes (w-LEDs) were synthesized by the conventional solid-state reaction. X-ray powder diffraction (XRD) analysis confirmed the phase formation of LiSrPO{sub 4}:Dy{sup 3+} materials. Luminescence properties results showed that the phosphor could be efficiently excited by the UV-vis light region from 250 to 460 nm, and it exhibited blue (483 nm) and yellow (574 nm) emission corresponding to {sup 4}F{sub 9/2} {yields} {sup 6}H{sub 15/2} transitions and {sup 4}F{sub 9/2} {yields} {sup 6}H{sub 13}/{sub 2} transitions, respectively. The luminescence intensity of LiSrPO{sub 4}:xDy{sup 3+} phosphor firstly increased and then decreased with increasing Dy{sup 3+} concentration, and reached the maximum at x = 0.03. It was found that concentration quenching occurred as a result of dipole-dipole interaction according to the Dexter's theory. The decay time was also determined for various concentrations of Dy{sup 3+} in LiSrPO{sub 4}.

  14. A novel method for preparing pomegranate-structured FePO4/C composite materials as cathode for lithium-ion batteries

    International Nuclear Information System (INIS)

    Hao, Guan-nan; Zhang, Hao; Chen, Xiao-Hong; Cao, Gao-Ping; Yang, Yusheng

    2012-01-01

    Graphical abstract: Display Omitted Highlights: ► We designed and synthesized a pomegranate-structured FePO 4 /C composite. ► We used a combination of electrospinning and solid-state reaction for preparation. ► We showed how the performance of pomegranate-structured FePO 4 is highly enhanced. -- Abstract: A pomegranate-structured FePO 4 /C composite was synthesized via a combination of electrospinning and high temperature reaction using micron-level FePO 4 and polyacrylonitrile (PAN). Systematic studies on synthesis, modification, and characterization of FePO 4 /C composites were conducted. The FePO 4 /C composites delivered a specific discharge capacity of 109 mAh g −1 at 0.2 C and 39 mAh g −1 at 10 C, which were comparable with the reported nanometer-level FePO 4 . We demonstrated that the three-dimensional net-like structure covered by porous carbon layers could highly enhance the electrochemical performance of FePO 4 .

  15. Radiocesium in wheat of the Po plain

    International Nuclear Information System (INIS)

    Dominici, G.; Malvicini, A.

    1988-01-01

    The Cs-137 measurements of many wheat samples, which was cultivated in Po plain during 1986 and 1987, are reported. A relationship is also shown between the quantity of Cs-137, which is contained in total fall-out, and that in the wheat by direct deposition

  16. A cell wall-bound anionic peroxidase, PtrPO21, is involved in lignin polymerization in Populus trichocarpa

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chien-Yuan; Li, Quanzi; Tunlaya-Anukit, Sermsawat; Shi, Rui; Sun, Ying-Hsuan; Wang, Jack P.; Liu, Jie; Loziuk, Philip; Edmunds, Charles W.; Miller, Zachary D.; Peszlen, Ilona; Muddiman, David C.; Sederoff, Ronald R.; Chiang, Vincent L.

    2016-03-11

    Class III peroxidases are members of a large plant-specific sequence-heterogeneous protein family. Several sequence-conserved homologs have been associated with lignin polymerization in Arabidopsis thaliana, Oryza sativa, Nicotiana tabacum, Zinnia elegans, Picea abies, and Pinus sylvestris. In Populus trichocarpa, a model species for studies of wood formation, the peroxidases involved in lignin biosynthesis have not yet been identified. To do this, we retrieved sequences of all PtrPOs from Peroxibase and conducted RNA-seq to identify candidates. Transcripts from 42 PtrPOs were detected in stem differentiating xylem (SDX) and four of them are the most xylem-abundant (PtrPO12, PtrPO21, PtrPO42, and PtrPO64). PtrPO21 shows xylem-specific expression similar to that of genes encoding the monolignol biosynthetic enzymes. Using protein cleavage-isotope dilution mass spectrometry, PtrPO21 is detected only in the cell wall fraction and not in the soluble fraction. Downregulated transgenics of PtrPO21 have a lignin reduction of ~20% with subunit composition (S/G ratio) similar to wild type. The transgenics show a growth reduction and reddish color of stem wood. The modulus of elasticity (MOE) of the stems of the downregulated PtrPO21-line 8 can be reduced to ~60% of wild type. Differentially expressed gene (DEG) analysis of PtrPO21 downregulated transgenics identified a significant overexpression of PtPrx35, suggesting a compensatory effect within the peroxidase family. No significant changes in the expression of the 49 P. trichocarpa laccases (PtrLACs) were observed.

  17. Study of distribution of 210Po and 210Pb in the environmental matrices of Chikmagalur, Karnataka, India

    International Nuclear Information System (INIS)

    Jayasheelan, A.; Sannappa, J.; Umeshareddy, K.; Ningappa, C.; Manjunatha, S.

    2013-01-01

    Polonium-210 and lead-210 are amongst the more radiotoxic nuclides and their concentration in soil and drinking water is very important from a radiological point of view. 210 Po is produced from the decay of 222 Rn gas in the atmosphere from which it is deposited on the earth's surface. 210 Po and 210 Pb in natural environment provide considerable radiation exposure to humans. In the present study, the concentrations of 210 Po and 210 Pb in the environment of Tumkur were studied. Soil and water samples were collected from ten Taluks of Tumkur and 210 Po and 210 Pb were determined by wet ashing method. Samples containing polonium was digested using conc. nitric acid and later converted into chloride medium with HCL. Polonium is deposited on the surface of the silver planchet and the activity on both sides were counted in a low background alpha counting system. The sample solution after estimation of 210 Po was preserved for 6-8 months for sufficient growth of 210 Po from 210 Pb. Then the 210 Po was re-estimated to determine the 210 Pb concentration by knowing its growth factor. The concentrations of 210 Po and 210 Pb in soils of different Taluks varied from 13.6 BqKg -1 and 26.8 to 113.4 BqKg -1 respectively. The concentrations of 210 Po and 210 Pb in water was low compared to soil, they varied 0.12 Bql -1 to 0.54 Bql -1 and 0.42 Bql -1 to 1.12 Bql -1 . (author)

  18. Structural and electrochemical characterization of 0.7LiFePO4·0.3Li3V2(PO4)3/C cathode materials using PEG and glucose as carbon sources

    International Nuclear Information System (INIS)

    Ma, Pingping; Hu, Pu; Liu, Zhijian; Xia, Jianhua; Xia, Dingguo; Chen, Yu; Liu, Zhengang; Lu, Zhichao

    2013-01-01

    0.7LiFePO 4 ·0.3Li 3 V 2 (PO 4 ) 3 /C composites (LFVP/C) were synthesized via spray-drying technique followed by solid-state reaction approach using polyethylene glycol (PEG) and glucose as carbon sources. The samples were characterized by X-ray diffraction (XRD), X-ray absorption fine-structure spectroscopy (XAFS) and Raman spectroscopy. The results show that the bi-phase composite structure of LFVP/C contains olivine LiFePO 4 (LFP) and monoclinic Li 3 V 2 (PO 4 ) 3 (LVP). The lower intensity ratio of the I D /I G and A sp 3 /A sp 2 for PEG-200 indicates the formation of higher degree of graphitized carbon during the process, which would enhance the electronic conductivity. The composite obtained using PEG-200 as carbon source show excellent rate performance, delivering the discharge capacity of 120 mAh/g at the current density of 1.5 A/g

  19. The low-lying yrast structure of 212Po

    International Nuclear Information System (INIS)

    Poletti, A.R.; Dracoulis, G.D.; Byrne, A.P.; Stuchbery, A.E.

    1987-01-01

    The properties of states in 212 Po populated by the 208 Pb( 9 Be,αn) 212 Po reaction have been investigated. The previously proposed yrast scheme below ≅ 3 MeV has been verified and eight further transitions placed in the level scheme. Mean lives of the 6 + , 8 + and (10 + ) states at 1355, 1476 and 1834 keV have been measured at 1.1 (3), 24.6 (3) and 0.8 (2) ns respectively. Shell model calculations using effective interactions were used to interpret the observed scheme. A synthesis of all available theoretical and experimental evidence allows the τ m = 65 s isomer to be identified clearly as the 18 + level arising primarily from the π(h 2 9/2 ) * ν(g 9/2 i 11/2 ) configuration. (orig.)

  20. Deuteron momentum distribution in KD2PO4

    International Nuclear Information System (INIS)

    Reiter, G; Shukla, A; Platzman, P M; Mayers, J

    2008-01-01

    The momentum distribution in KD 2 PO 4 (DKDP) has been measured using neutron Compton scattering above and below the weakly first-order paraelectric-ferroelectric phase transition (T=229 K). There is very little difference between the two distributions, and no sign of the coherence over two locations for the proton observed in the paraelectric phase, as in KH 2 PO 4 (KDP). We conclude that the tunnel splitting must be much less than 20 meV. The width of the distribution indicates that the effective potential for DKDP is significantly softer than that for KDP. As electronic structure calculations indicate that the stiffness of the potential increases with the size of the coherent region locally undergoing soft mode fluctuations, we conclude that there is a mass-dependent quantum coherence length in both systems

  1. Visible-light-driven TiO2/Ag3PO4/GO heterostructure photocatalyst with dual-channel for photo-generated charges separation

    International Nuclear Information System (INIS)

    Lu, Bingqing; Ma, Ni; Wang, Yaping; Qiu, Yiwei; Hu, Haihua; Zhao, Jiahuan; Liang, Dayu; Xu, Sheng; Li, Xiaoyun; Zhu, Zhiyan; Cui, Can

    2015-01-01

    Highlights: • TiO 2 /Ag 3 PO 4 /GO was synthesized with a facile two-step method. • TiO 2 /Ag 3 PO 4 /GO exhibit superior photocatalytic activity and stability. • TiO 2 /Ag 3 PO 4 /GO has dual-channel for photo-generated charges separation. • TiO 2 /Ag 3 PO 4 /GO composite reduces the consumption of Ag. - Abstract: A novel triple-component TiO 2 /Ag 3 PO 4 /graphene oxide (TiO 2 /Ag 3 PO 4 /GO) photocatalyst with dual channels for photo-generated charges separation has been synthesized to improve the photocatalytic activity and stability of Ag 3 PO 4 under visible light. The synthesis involved in-situ growth of Ag 3 PO 4 nanoparticles on GO sheets to form Ag 3 PO 4 /GO, and then deposited TiO 2 nanocrystals on the surface of Ag 3 PO 4 by hydrolysis of Ti(SO 4 ) 2 at low-temperature hydrothermal condition. The TiO 2 /Ag 3 PO 4 /GO exhibited superior photocatalytic activity and stability to bare Ag 3 PO 4 , TiO 2 /Ag 3 PO 4 and Ag 3 PO 4 /GO in degradation of Rhodamine B and phenol solutions under visible light. It is suggested that the photo-generated electrons in the conduction band of Ag 3 PO 4 can be quickly transferred to GO, while the holes in the valence band of Ag 3 PO 4 can be transferred to the valence band of TiO 2 . The dual transfer channels at the interfaces of TiO 2 /Ag 3 PO 4 /GO result in effective charges separation, leading to enhanced photocatalytic activity and stability. Furthermore, the content of noble metal Ag significantly reduces from 77 wt% in bare Ag 3 PO 4 to 55 wt% in the nanocomposite. The concept of establishing dual channels for charges separation in a triple-component heterostructure provides a promising way to develop photocatalysts with high efficiency

  2. Crystalline maricite NaFePO4 as a positive electrode material for sodium secondary batteries operating at intermediate temperature

    Science.gov (United States)

    Hwang, Jinkwang; Matsumoto, Kazuhiko; Orikasa, Yuki; Katayama, Misaki; Inada, Yasuhiro; Nohira, Toshiyuki; Hagiwara, Rika

    2018-02-01

    Maricite NaFePO4 (m-NaFePO4) was investigated as a positive electrode material for intermediate-temperature operation of sodium secondary batteries using ionic liquid electrolytes. Powdered m-NaFePO4 was prepared by a conventional solid-state method at 873 K and subsequently fabricated in two different conditions; one is ball-milled in acetone and the other is re-calcined at 873 K after the ball-milling. Electrochemical properties of the electrodes prepared with the as-synthesized m-NaFePO4, the ball-milled m-NaFePO4, and the re-calcined m-NaFePO4 were investigated in Na[FSA]-[C2C1im][FSA] (C2C1im+ = 1-ethyl-3-methylimidazolium, FSA- = bis(fluorosulfonyl)amide) ionic liquid electrolytes at 298 K and 363 K to assess the effects of temperature and particle size on their electrochemical properties. A reversible charge-discharge capacity of 107 mAh g-1 was achieved with a coulombic efficiency >98% from the 2nd cycle using the ball-milled m-NaFePO4 electrode at a C-rate of 0.1 C and 363 K. Electrochemical impedance spectroscopy using m-NaFePO4/m-NaFePO4 symmetric cells indicated that inactive m-NaFePO4 becomes an active material through ball-milling treatment and elevation of operating temperature. X-ray diffraction analysis of crystalline m-NaFePO4 confirmed the lattice contraction and expansion upon charging and discharging, respectively. These results indicate that the desodiation-sodiation process in m-NaFePO4 is reversible in the intermediate-temperature range.

  3. Identifying compatibility of lithium salts with LiFePO4 cathode using a symmetric cell

    Science.gov (United States)

    Tong, Bo; Wang, Jiawei; Liu, Zhenjie; Ma, Lipo; Zhou, Zhibin; Peng, Zhangquan

    2018-04-01

    The electrochemical performance of lithium-ion batteries is dominated by the interphase electrochemistry between the electrolyte and electrode materials. A multitude of efforts have been dedicated to the solid electrolyte interphase (SEI) formed on the anode. However, the interphase on the cathode, namely the cathode electrolyte interphase (CEI), is left aside, partially due to the fact that it is hard to single out the CEI considering the complicated anode-cathode inter-talk. Herein, a partially delithiated lithium iron phosphate (Li0.25FePO4) electrode is used as the anode. Owing to a high voltage plateau (≈3.45 V vs. Li/Li+), negligible reduction reactions of electrolyte occur on the L0.25FePO4 anode. Therefore, the CEI can be investigated exclusively. Using a LiFePO4|Li0.25FePO4 symmetric cell configuration, we scrutinize the compatibility of the electrolytes containing a wide spectrum of lithium salts, Li[(FSO2)(Cm F2m+1SO2)N] (m = 0, 1, 2, 4), with the LiFePO4, in both cycling and calendar tests. It is found that the Li[(FSO2)(n-C4F9SO2)N] (LiFNFSI)-based electrolyte exhibits the highest compatibility with LiFePO4.

  4. Discharge of 210Po and 210Pb in coastal groundwater to the ocean

    International Nuclear Information System (INIS)

    Kim, Intae; Kim, Tae-hoon; Kim, Guebuem

    2013-01-01

    The activities of 210 Po and 210 Pb were measured for the truly dissolved (<10 kDa) and colloidal (10 kDa - 0.45 ìm) phases in coastal ground water in 2010 and 2011. The sampling sites include the coast of a large tidal flat (Hampyeong Bay) and a volcanic island, Jeju, Korea, where submarine groundwater discharge (SGD) were reported to be higher than typical continental margins. The total dissolved fraction was separated into the colloidal and truly dissolved fractions using a tangential flow filtration (TFF) system (PLCGC Pellicon). The total 210 Po and 210 Pb activities in ground water were 1.0 - 18.2 dpm/100L (9.7±7.6 dpm/100L) an 2.9 - 29.1 dpm/100L (16.8±10.7 dpm/100L) in the Hampyeong Bay and Jeju Island samples, respectively. The total 210 Po and 210 Pb activities in groundwater were similar to or even slightly lower than those in the typical seawater. These lower activities seem to be due to the rapid adsorption of Po and Pb on to particles in the subterranean estuary. The proportions of the truly dissolved and colloidal phases were, respectively, 73±5% and 27±5% for 210 Po, and 60±5% and 40±5% for 210 Pb. This result is consistent with the earlier study that more than half of the some dissolved trace metals in coastal ground water are in the colloidal form. Thus, our result implies that the colloidal forms are important in controlling the behaviour of Po, Pb, and other trace metals in the subterranean estuary and SGD-associated fluxes to the ocean. (author)

  5. Ingestion of 210Po by public residing in and around Kalpakkam through dietary source

    International Nuclear Information System (INIS)

    Arunachalam, Kantha Deivi; Baskaran, Kamesh Viswanathan; Annamalai, Sathesh Kumar; Sivasubramanian, K.S.; Venkatraman, B.

    2014-01-01

    The distribution of naturally occurring radionuclide Polonium-210 ( 210 Po) activity in dietary source of Kalpakkam, Nuclear Power Plant, Tamil Nadu and its nearby region was studied. The 210 Po was analyzed in the food materials consumed by the male and female individuals (he/she) living in the study area of Kalpakkam (nuclear power plant) was done by 24-hr Duplicate Diet Study (DDS) and Market Basket Study (MBS). The MBS was done by collecting the food materials such as, cereals, fruits, nuts, leafy vegetables, other vegetables, fish, meat and milk collected from the study area. The DDS was done by collecting the food materials including the beverages consumed in 24 h from different age groups of male and female individuals living in surroundings of Kalpakkam. The intake and ingestion dose of the radionuclide 210 Po was estimated. The mean concentration of 210 Po in DDS (n= 33) was found to be 36 mBq.kg -1 of fresh weight. The MBS was collected based on food consumption representing more than 85-95% of annual supply, and were divided into 8 food groups. The mean concentration of 210 Po in 8 food groups namely leafy vegetables was 288 mBq.kg -1 (n=4), vegetables 33 mBq.kg -1 (n=12), fish 7294 mBq.kg -1 (n=5) and cereal 34 (n=1) mBq.kg -1 of fresh weight respectively. The remaining food categories such as nuts (n=1), fruits (n= 4), meat food (n= 2) and milk (n= 2) are below detection limit of 30 mBq.kg -1 fresh weight. The annual intake and ingestion dose due to 210 Po was estimated by DDS and MBS in adults, adolescents and children. Thereby, discussing the risk level of 210 Po ingestion to the local inhabitants in Kalpakkam region. (author)

  6. Inhalation of {sup 210}Po and {sup 210}Pb from cigarette smoking in Poland

    Energy Technology Data Exchange (ETDEWEB)

    Skwarzec, B. E-mail: bosk@chemik.chem.univ.gda.pl; Ulatowski, J.; Struminska, D.I.; Borylo, A

    2001-07-01

    The carcinogenic effect of {sup 210}Po and {sup 210}Pb with respect to lung cancer is an important problem in many countries with very high cigarette consumption. Poland has one of the highest consumptions of cigarettes in the world. The results of {sup 210}Po determination on the 14 most frequently smoked brands of cigarettes which constitute over 70% of the total cigarette consumption in Poland are presented and discussed. Moreover, the polonium content in cigarette smoke was estimated on the basis of its activity in fresh tobaccos, ash, fresh filters and post-smoking filters. The annual effective doses were calculated on the basis of {sup 210}Po and {sup 210}Pb inhalation with the cigarette smoke. The results of this work indicate that Polish smokers who smoke one pack (20 cigarettes) per day inhale from 20 to 215 mBq of {sup 210}Po and {sup 210}Pb each. The mean values of the annual effective dose for smokers were estimated to be 35 and 70 {mu}Sv from {sup 210}Po and {sup 210}Pb, respectively. For persons who smoke two packs of cigarettes with higher radionuclide concentrations, the effective dose is much higher (471 {mu}Sv yr{sup -1}) in comparison with the intake in diet. Therefore, cigarettes and the absorption through the respiratory system are the main sources and the principal pathway of {sup 210}Po and {sup 210}Pb intake of smokers in Poland.

  7. Luminescence characteristics and glow curves analysis of Cu"+ doped Li_3PO_4 phosphor

    International Nuclear Information System (INIS)

    Aghalte, G.A.; Dhoble, S.J.; Pawar, N.R.

    2016-01-01

    Li_3PO_4:Cu exhibits useful TL properties in personnel dosimetry of ionizing radiations. Cu is known to be one of the most efficient activator. The PL intensity is found to increase consistently with the increasing quenching temperature. Cu"+ doped Li_3PO_4 phosphor was synthesized by the wet chemical co-precipitation method. The crystal structure and particle morphology of the phosphor was investigated by using X-ray diffraction and scanning electron microscopy. Li_3PO_4:Cu is excellent phosphor for TL dosimetry. For the synthesis of Li_3PO_4:Cu phosphor the stoichiometric amounts of LiOH·H_2O and CuSO_4·"5H_2O were dissolved separately and then the solutions were mixed together. It was precipitated by using concentrated H_3PO_4. The precipitate was filtered out immediately and kept 12 hours below IR lamp. Prepared dry Li_3PO_4:Cu powder was then put on 2.5 wt% NH_4Cl in graphite crucible in preheated furnace at 800°C and was kept for 1 hour. It was then rapidly quenched to room temperature. Thermoluminescence (TL) glow curves were recorded on Nucleonix TL Reader with a heating rate of 2°C per second in the temperature range of 50-250°C. The PMT voltage was 750 volts. Photoluminescence (PL) studies were carried out by Hitachi F-4000 spectrophotometer with a spectral slit width of 1.5 nm

  8. Variationas of 210Po Activity in Mussels (Perna viridis) of Samut Sakhon and Its Contribution to Dose Assessment

    International Nuclear Information System (INIS)

    Porntepkasemsan, B; Srisuksawad, K.; Permnamtip, V.

    2014-01-01

    Levels of 210 Po and its effective dose in green mussel (Perna viridis) collected from mussel farming area at the Samut Sakhon province during the period of 2012-2013 are presented. Several parameters including maximum shell length and the physiological performance of mussels using condition index and physical properties of seawater (pH, salinity, conductivity, TDS, DO and cation-anion elements) were measured. Each individual mussel was measured on its maximum shell length which was adopted as size class. The activity concentration of 210Po was determined spectroscopically through its 5.30 MeV alpha particle emission, using 209 Po as an internal tracer. The 210 Po activity concentration in mussels was found to vary between 1.044 and 6.951 Bq.kg-1 wet weight. The 210 Po concentration was higher in smaller sized classes (>35 mm) and lowest in larger ones (40-70 mm). This confirms that larger mussels have lower 210Po levels on a weight basis. The 210 Po body burden (activity per mussel) ranged from 1.035 to 17.183 mBq. Contrary to the 210 Po concentrations, results of the body burden revealed the lower activities in smaller sized mussels (>35 mm) and the higher in larger sized ones (40-70 mm). The type of fluctuations observed with 210 Po concentrations are interpreted as a seasonal effect. Total annual effective 210 Po dose due to mussel consumption was calculated to be in the range of 3.081 to 16.401 μSv. Based on the international guideline, the average dose calculated due to 210 Po in mussels of Samut Sakhon would not pose any significant radiological impact on human health and the mussels are considered to be safe for intake.

  9. Linear-to-λ-Shape P-O-P Bond Transmutation in Polyphosphates with Infinite (PO3)∞ Chain.

    Science.gov (United States)

    Wang, Ying; Li, Lin; Han, Shujuan; Lei, Bing-Hua; Abudoureheman, Maierhaba; Yang, Zhihua; Pan, Shilie

    2017-09-05

    A new metal polyphosphate, α-CsBa 2 (PO 3 ) 5 , exhibiting the first example of a linear P-O-P bond angle in a one-dimensional (PO 3 ) ∞ chain has been reported. Interestingly, α → β phase transition occurs in CsBa 2 (PO 3 ) 5 along with the P-O-P bonds varying from linear to λ-shape, suggesting that α-CsBa 2 (PO 3 ) 5 with unfavorable linear P-O-P bonds is more stable at ambient temperature.

  10. Graphene Modified LiFePO4 Cathode Materials for High Power Lithium ion Batteries

    International Nuclear Information System (INIS)

    Zhou, X.; Wang, F.; Zhu, Y.; Liu, Z.

    2011-01-01

    Graphene-modified LiFePO 4 composite has been developed as a Li-ion battery cathode material with excellent high-rate capability and cycling stability. The composite was prepared with LiFePO 4 nanoparticles and graphene oxide nanosheets by spray-drying and annealing processes. The LiFePO 4 primary nanoparticles embedded in micro-sized spherical secondary particles were wrapped homogeneously and loosely with a graphene 3D network. Such a special nanostructure facilitated electron migration throughout the secondary particles, while the presence of abundant voids between the LiFePO 4 nanoparticles and graphene sheets was beneficial for Li + diffusion. The composite cathode material could deliver a capacity of 70 mAh g -1 at 60C discharge rate and showed a capacity decay rate of <15% when cycled under 10C charging and 20C discharging for 1000 times.

  11. Additional of polyethylene glycol on the preparation of LaPO4:Eu3+ phosphor

    Science.gov (United States)

    Panatarani, Camellia; Joni, I. Made

    2013-09-01

    Solution phase method was used to synthesis nanocrystal LaPO4:Eu3+. Polyethylene glycol with vary molecular weight (MW) was added to allow an exothermic reaction to get a high crystalinity of LaPO4:Eu3+. The x-ray pattern of as prepared LaPO4 was obtained by using an X'pert PANalytical diffractometer with CuKα radiation (λ = 1.5406 Å) and the photoluminescent measurement spectra is obtained by using Fluorescence Spectrometer LS55, Perkin Elmer. The additional of various MW of polyethylene glycol into the precursor solution of LaPO4:Eu3+ affected the crystal structure and luminescent properties. Higher MW of PEG depressing the luminescent spectra. The emission origin from 5D0-7F4 transition vanished by additional 500,000 and 2,000,000 MW of PEG.

  12. Study on SOC wavelet analysis for LiFePO4 battery

    Science.gov (United States)

    Liu, Xuepeng; Zhao, Dongmei

    2017-08-01

    Improving the prediction accuracy of SOC can reduce the complexity of the conservative and control strategy of the strategy such as the scheduling, optimization and planning of LiFePO4 battery system. Based on the analysis of the relationship between the SOC historical data and the external stress factors, the SOC Estimation-Correction Prediction Model based on wavelet analysis is established. Using wavelet neural network prediction model is of high precision to achieve forecast link, external stress measured data is used to update parameters estimation in the model, implement correction link, makes the forecast model can adapt to the LiFePO4 battery under rated condition of charge and discharge the operating point of the variable operation area. The test results show that the method can obtain higher precision prediction model when the input and output of LiFePO4 battery are changed frequently.

  13. A history of calcium orthophosphates (CaPO4) and their biomedical applications.

    Science.gov (United States)

    Dorozhkin, S V

    2017-09-01

    The historical development of a scientific knowledge on calcium orthophosphates (CaPO 4 ) from 1770-s till 1950 is described. Many forgotten and poorly known historical facts and approaches have been extracted from old publications and then they have been analyzed, systematized and reconsidered from the modern point of view. The chosen time scale starts with the earliest available studies of 1770-s (to the best of my findings, CaPO 4 had been unknown before), passes through the entire 19th century and finishes in 1950, because since then the amount of publications on CaPO 4 rapidly increases and the subject becomes too broad. Furthermore, since publications of the second half of the 20th century are easily accessible, the substantial amount of them has been already reviewed by other researchers. The reported historical findings clearly demonstrate that the substantial amount of the scientific facts and experimental approaches has been known for very many decades and, in fact, the considerable quantity of relatively recent investigations on CaPO 4 is just either a further development of the earlier studies or a rediscovery of the already forgotten knowledge. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. Dosimetry of 210Po in humans, caribou, and wolves in northern Canada

    International Nuclear Information System (INIS)

    Thomas, P.A.

    1994-01-01

    Effective doses from 210 Po intake with caribou meat were determined for human residents in Baker Lake and Snowdrift in the Northwest Territories of Canada and compared to doses calculated from reported 210 Po tissue activities in Alaskan and British residents. Effective doses were calculated to separate body tissues, using ICRP 60 human weighting factors and the ICRP 30 metabolic model for 210 Po. Baker Lake and Alaskan effective doses were similar at 0.4 mSv y -1 and slightly higher than Snowdrift doses (0.3 mSv y -1 ). Alaskan tissue activities indicated higher effective doses to liver, bone surfaces and red marrow and lower doses to spleen than the 210 Po metabolic model (ICRP 1979a) predicts. Effective doses to Baker Lake and Snowdrift caribou and wolves, calculated from tissue activities, ranged from 7-20 mSv y -1 using human weighting factors for comparison to human doses only. Effective doses to northern Canadians and wildlife were, respectively, 7-11% and 1.8-5 times an estimated human background of 4 mSv y - from all sources. 51 refs., 2 figs., 9 tabs

  15. Large-Area Balloon-Borne Polarized Gamma Ray Observer (PoGO)

    International Nuclear Information System (INIS)

    Andersson, V.; Chen, P.; Kamae, T.; Madejski, G.; Mizuno, T.; Ng, J.; Tajima, H.; Thurston, T.; SLAC; Bogaert, G.; Ecole Polytechnique; Fukazawa, Y.; Hiroshima U.; Saito, Y.; Takahashi, T.; Sagamihara, Inst. Space Astron. Sci.; Barbier, L.; Bloser, P.; Harding, A.; Hunter, S.; Krizmanic, J.; Mitchell, J.; Streitmatter, R.; Fernholz, R.; Groth, E.; NASA, Goddard; Princeton U.; Royal Inst. Tech., Kista; Stockholm U.; Tokyo Inst. Tech.; Yamagata U.

    2005-01-01

    We are developing a new balloon-borne instrument (PoGO), to measure polarization of soft gamma rays (30-200 keV) using asymmetry in azimuth angle distribution of Compton scattering. PoGO is designed to detect 10% polarization in 100mCrab sources in a 6-8 hour observation and bring a new dimension to studies on gamma ray emission/transportation mechanism in pulsars, AGNs, black hole binaries, and neutron star surface. The concept is an adaptation to polarization measurements of well-type phoswich counter consisting of a fast plastic scintillator (the detection part), a slow plastic scintillator (the active collimator) and a BGO scintillator (the bottom anti-counter). PoGO consists of close-packed array of 217 hexagonal well-type phoswich counters and has a narrow field-of-view (∼ 5 deg 2 ) to reduce possible source confusion. A prototype instrument has been tested in the polarized soft gamma-ray beams at Advanced Photon Source (ANL) and at Photon Factory (KEK). On the results, the polarization dependence of EGS4 has been validated and that of Geant4 has been corrected

  16. Large-Area Balloon-Borne Polarized Gamma Ray Observer (PoGO)

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, V.; Chen, P.; Kamae, T.; Madejski, G.; Mizuno, T.; Ng, J.; Tajima, H.; Thurston, T.; /SLAC; Bogaert, G.; /Ecole Polytechnique; Fukazawa, Y.; /Hiroshima U.; Saito,; Takahashi, T.; /Sagamihara, Inst. Space Astron. Sci.; Barbier, L.; Bloser, P.; Harding, A.; Hunter, S.; Krizmanic, J.; Mitchell, J.; Streitmatter, R.; Fernholz, R.; Groth, E.; /NASA, Goddard /Princeton U. /Royal Inst. Tech., Kista /Stockholm U. /Tokyo Inst. Tech. /Yamagata U.

    2005-06-30

    We are developing a new balloon-borne instrument (PoGO), to measure polarization of soft gamma rays (30-200 keV) using asymmetry in azimuth angle distribution of Compton scattering. PoGO is designed to detect 10% polarization in 100mCrab sources in a 6-8 hour observation and bring a new dimension to studies on gamma ray emission/transportation mechanism in pulsars, AGNs, black hole binaries, and neutron star surface. The concept is an adaptation to polarization measurements of well-type phoswich counter consisting of a fast plastic scintillator (the detection part), a slow plastic scintillator (the active collimator) and a BGO scintillator (the bottom anti-counter). PoGO consists of close-packed array of 217 hexagonal well-type phoswich counters and has a narrow field-of-view ({approx} 5 deg{sup 2}) to reduce possible source confusion. A prototype instrument has been tested in the polarized soft gamma-ray beams at Advanced Photon Source (ANL) and at Photon Factory (KEK). On the results, the polarization dependence of EGS4 has been validated and that of Geant4 has been corrected.

  17. Tunable morphology synthesis of LiFePO4 nanoparticles as cathode materials for lithium ion batteries.

    Science.gov (United States)

    Ma, Zhipeng; Shao, Guangjie; Fan, Yuqian; Wang, Guiling; Song, Jianjun; Liu, Tingting

    2014-06-25

    Olivine LiFePO4 with nanoplate, rectangular prism nanorod and hexagonal prism nanorod morphologies with a short b-axis were successfully synthesized by a solvothermal in glycerol and water system. The influences of solvent composition on the morphological transformation and electrochemical performances of olivine LiFePO4 are systematically investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and galvanostatic charge-discharge tests. It is found that with increasing water content in solvent, the LiFePO4 nanoplates gradually transform into hexagonal prism nanorods that are similar to the thermodynamic equilibrium shape of the LiFePO4 crystal. This indicates that water plays an important role in the morphology transformation of the olivine LiFePO4. The electrochemical performances vary significantly with the particle morphology. The LiFePO4 rectangular prism nanorods (formed in a glycerol-to-water ratio of 1:1) exhibit superior electrochemical properties compared with the other morphological particles because of their moderate size and shorter Li(+) ion diffusion length along the [010] direction. The initial discharge capacity of the LiFePO4@C with a rectangular prism nanorod morphology reaches to 163.8 mAh g(-1) at 0.2 C and over 75 mAh g(-1) at the high discharging rate of 20 C, maintaining good stability at each discharging rate.

  18. [100]-Oriented LiFePO4 Nanoflakes toward High Rate Li-Ion Battery Cathode.

    Science.gov (United States)

    Li, Zhaojin; Peng, Zhenzhen; Zhang, Hui; Hu, Tao; Hu, Minmin; Zhu, Kongjun; Wang, Xiaohui

    2016-01-13

    [100] is believed to be a tough diffusion direction for Li(+) in LiFePO4, leading to the belief that the rate performance of [100]-oriented LiFePO4 is poor. Here we report the fabrication of 12 nm-thick [100]-oriented LiFePO4 nanoflakes by a simple one-pot solvothermal method. The nanoflakes exhibit unexpectedly excellent electrochemical performance, in stark contrast to what was previously believed. Such an exceptional result is attributed to a decreased thermodynamic transformation barrier height (Δμb) associated with increased active population.

  19. Intake of 226Ra, 210Pb and 210Po with food in Poland

    International Nuclear Information System (INIS)

    Pietrzak-Flis, Z.; Chrzanowski, E.; Dembinska, S.

    1997-01-01

    Intake with food and water of 226 Ra, 210 Pb and 210 Po was determined for an adult population in regions of central, northern and northeastern Poland. The content of radionuclides was determined in the daily diet and, in the central region, also in foodstuffs and drinking water. The annual intake with foodstuffs was estimated on the basis of their average annual consumption. The 226 Ra intake in northeastern Poland was approximately 17% higher than the overall average, correlating well with the higher concentration of this radionuclide in the soil. The 210 Po/ 210 Pb ratio was close to unity in the continental regions, whereas at the Baltic Sea coast it was approximately 1.5. The latter value can be ascribed to a larger consumption of fish for which the 210 Po/ 210 Pb ratio was found to be approximately 10. In central Poland the largest intake of 226 Ra was with flour and vegetables (contribution approx. 60%), the largest intake of 210 Pb was with flour and meat (approx. 50%) and the largest intake of 210 Po was with fish (approx. 34%). From the intake and dose coefficient, annual effective doses were calculated. The dose from 210 Pb and 210 Po was approx. 54 μSv year -1 , and the dose from 226 Ra was approx. 4 μSv year -1

  20. Improved optimum condition for recovery and measurement of 210Po in environmental samples

    International Nuclear Information System (INIS)

    Zal Uyun Wan Mahmood; Norfaizal Mohamed; Nik Azlin Nik Ariffin; Abdul Kadir Ishak

    2012-01-01

    An improved laboratory technique for measurement of polonium-210( 210 Po) in environmental samples has been developed in Radiochemistry and Environmental Laboratory (RAS), Malaysian Nuclear Agency. To further improve this technique, a study with the objectives to determine the optimum conditions for 210 Po deposition and; evaluate the accuracy and precision results for the determination of 210 Po in environmental samples was carried-out. Polonium-210 which is an alpha emitter obtained in acidic solution through total digestion and dissolution of samples has been efficiently plated onto one side of the silver disc in the spontaneous plating process for measurement of its alpha activity. The optimum conditions for deposition of 210 Po were achieved using hydrochloric acid (HCl) media at acidity of 0.5 M with the presence of 1.0 gram hydroxyl ammonium chloride and the plating temperature at 90 degree Celsius. The plating was carried out in 80 ml HCl solution (0.5 M) for 4 hours. The recorded recoveries obtained using 209 Po tracers in the CRM IAEA-385 and environmental samples were 85 % - 98% whereby the efficiency of the new technique is a distinct advantage over the existing techniques. Therefore, optimization of deposition parameters is a prime importance to achieve accuracy and precision results as well as economy and time saving. (author)

  1. Effect of microstructure on low temperature electrochemical properties of LiFePO4/C cathode material

    International Nuclear Information System (INIS)

    Zhao, Nannan; Zhi, Xiaoke; Wang, Li; Liu, Yanhui; Liang, Guangchuan

    2015-01-01

    Graphical abstract: The low temperature performance of Li-ion batteries and LiFePO 4 /C composites was discussed. A conclusion that cathode material is the main limitation for the low temperature performance was come up, by comparing the low temperature performance of 18650 Li-ion batteries with LiMn 2 O 4 , LiNi 1/3 Co 1/3 Mn 1/3 O 2 and LiFePO 4 /C as cathode materials. The low temperature performance results indicate the LiFePO 4 /C microstructure is the main factor influencing the low temperature performance of LiFePO 4 . A new LiFePO 4 /C with pomegranate-like spherical structure was proposed in this paper, which shows superior low temperature performance, which can be attributed to its uniform fine primary particles and smaller primary particles. - Highlights: • Low temperature performance of Li-ion battery and LiFePO 4 /C composite was discussed. • Cathode material mainly decided the low temperature performance of Li-ion battery. • LiFePO 4 /C microstructure mainly affects its low temperature performance. • Pomegranate-like spherical structure LiFePO 4 /C has good low temperature performance. - Abstract: The low-temperature electrochemical performance of Li-ion batteries is mainly determined by the choice of cathode material, as evident from a comparison of the low-temperature electrochemical performance of the 18650 batteries with the LiMn 2 O 4 , LiNi 1/3 Co 1/3 Mn 1/3 O 2 , and LiFePO 4 /C as the cathode, respectively, at −20 °C. LiFePO 4 /C materials with different morphologies and microstructures were prepared by different methods. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), galvanostatic charge–discharge measurements and EIS. The low-temperature performance of the samples and those of the coin cells utilizing the materials as cathodes were measured. The results indicate that the microstructure of LiFePO 4 /C is a key factor determining the low

  2. AHP 47: A RIG RGAD PO VISITS LHA SA

    Directory of Open Access Journals (Sweden)

    Pad ma skyid པདྨ་སྐྱིད།

    2017-04-01

    Full Text Available My name is Pad ma skyid. I was born in 1981 in Pan yag Community, 'Bo spa Township, Pad ma County, Mgo log Tibetan Autonomous Prefecture, Mtsho sngon (Qinghai Province. I have eight siblings. Growing up in a black yak-hair tent, we spent our days playing with lambs, foals, and calves. We told all sorts of stories when everyone was in bed - stories about King Ge sar, ghosts, marriages, and tricksters. It was a time for my whole family to relax and share. I heard many A rig rgad po stories from my parents, siblings, and guests. A rig rgad po became part of my childhood. These stories bring back many beautiful memories. ...

  3. 210Po and 210Pb concentrations in fish consumed in Syria

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Mamish, S.; Budeir, Y.; Nashwaty, A

    2001-01-01

    Edible part of 36 types of sea fish collected from local market (Lattakia, Tartus, Banias) and seven types of river fish (Euphrate river and Mzerib lake) have been analyzed for sup 2 sup 1 sup 0 Po and sup 2 sup 1 sup 0 Pb. Results of analysis have shown that sup 2 sup 1 sup 0 Po and sup 2 sup 1 sup 0 Pb concentrations in sea fish varied between 0.27 and 27.48 Bq/kg and between 0.05 and 0.38 Bq/kg, respectively while for river fish concentrations were relatively low and varied between 0.61 and 3.08 Bq/kg for sup 2 sup 1 sup 0 Po and between 0.04 and 0.10 Bq/kg for sup 2 sup 1 sup 0 Pb. In addition, the Syrian adults daily intakes of sup 2 sup 1 sup 0 Po and sup 2 sup 1 sup 0 Pb have been estimated and found to be 6.0 and 0.24 mBq respectively. These intakes are much less than those reported in other areas in the world. The collective dose was also determined and found to be about 5.09 man.Sv for polonium sup 2 sup 1 sup 0 and 2.93 man.Sv for lead sup 2 sup 1 sup 0. (author)

  4. Probing the failure mechanism of nanoscale LiFePO{sub 4} for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Meng; Yan, Pengfei; Wang, Chongmin, E-mail: chongmin.wang@pnnl.gov [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States); Shi, Wei [Energy and Environmental Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352 (United States); National Active Distribution Network Technology Research Center, School of Electrical Engineering, Beijing Jiaotong University, 3 Shangyuancun Street, Haidian District, Beijing 100044 (China); Zheng, Jianming; Zhang, Ji-guang [Energy and Environmental Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352 (United States)

    2015-05-18

    LiFePO{sub 4} is a high power rate cathode material for lithium ion battery and shows remarkable capacity retention, featuring a 91% capacity retention after 3300 cycles. In this work, we use high-resolution transmission electron microscopy and electron energy loss spectroscopy to study the gradual capacity fading mechanism of LiFePO{sub 4} materials. We found that upon prolonged electrochemical cycling of the battery, the LiFePO{sub 4} cathode shows surface amorphization and loss of oxygen species, which directly contribute to the gradual capacity fading of the battery. The finding can guide the design and improvement of LiFePO{sub 4} cathode for high-energy and high-power rechargeable battery for electric transportation.

  5. Photoluminescence properties of Eu(3+)/ Sm(3+) activated CaZr4(PO4)6 phosphors.

    Science.gov (United States)

    Nair, Govind B; Dhoble, S J

    2016-09-01

    Solid state reaction method was employed for the synthesis of a series of CaZr4(PO4)6: Eu(3+)/Sm(3+) phosphors. The red-emitting CaZr4(PO4)6:Eu(3+) phosphors can be efficiently excited at 396 nm and thereby, exhibit a strong red luminescence predominantly corresponding to the electric dipole transition at 615 nm. Under 405 nm excitation, CaZr4(PO4)6:Sm(3+) phosphors display orange emission with color temperatures approximately around 2200 K. The acquired results reveal that CaZr4(PO4)6: RE(3+) (RE = Eu, Sm) phosphors could be potential candidates for red and orange emitting phosphor, respectively, for UV/blue-pump LEDs.

  6. Distribution of 210Pb and 210Po concentrations in wild berries and mushrooms in boreal forest ecosystems

    International Nuclear Information System (INIS)

    Vaaramaa, Kaisa; Solatie, Dina; Aro, Lasse

    2009-01-01

    The activity concentrations and distribution of 210 Pb and 210 Po in wild berries and edible mushrooms were investigated in Finnish forests. The main study areas were located in Scots pine (Pinus sylvestris L.) forests in southern and northern Finland. The activity concentrations of 210 Pb and 210 Po in blueberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.) samples decreased in the order: stems > leaves > berries (i.e. fruits). The activity ratios of 210 Po/ 210 Pb in the wild berry samples were mainly higher than one, indicating elevated activity concentrations of polonium in the samples. In mushrooms the activity concentrations of 210 Pb and especially 210 Po were higher than in fruits of the wild berries. The highest activity concentration of 210 Pb was detected in Cortinarius armillatus L. (16.2 Bq kg -1 d.w.) and the lowest in Leccinum vulpinum L. (1.38 Bq kg -1 d.w.). The 210 Po activity concentrations of the whole fruiting bodies ranged from 7.14 Bq kg -1 d.w. (Russula paludosa L.) to 1174 Bq kg -1 d.w. (L. vulpinum L.). In general, the highest activity concentrations of 210 Po were recorded in boletes. The caps of mushrooms of the Boletaceae family showed higher activity concentrations of 210 Po compared to the stipes. In most of the mushrooms analyzed, the activity concentrations of 210 Po were higher than those of 210 Pb. 210 Po and 210 Pb dominate the radiation doses received via ingestion of wild berries and mushrooms in northern Finland, while in southern Finland the ingested dose is dominated by 137 Cs from the Chernobyl fallout.

  7. Advanced LiTi2(PO4)3@N-doped carbon anode for aqueous lithium ion batteries

    International Nuclear Information System (INIS)

    He, Zhangxing; Jiang, Yingqiao; Meng, Wei; Zhu, Jing; Liu, Yang; Dai, Lei; Wang, Ling

    2016-01-01

    Highlights: • LiTi 2 (PO 4 ) 3 @N-doped carbon anode was prepared by in-situ coating approach for aqueous lithium ion batteries. • The well-proportioned N-doped carbon layer and loose nanoporous structure was obtained using urea as nitrogen source and pore former. • LiTi 2 (PO 4 ) 3 @N-doped carbon demonstrates excellent rate performance and good cycling stability. - Abstract: In this paper, LiTi 2 (PO 4 ) 3 @N-doped carbon anode has been synthesized by in situ carbon coating approach. The well-proportioned N-doped carbon layer and loose nanoporous structure was obtained by using urea as nitrogen source and pore former. LiTi 2 (PO 4 ) 3 @N-doped carbon as anode demonstrates much better rate capability than LiTi 2 (PO 4 ) 3 @carbon in ALIBs. The optimized anode delivers the discharge capacity of 93.7 mAh g −1 and 74.2 mAh g −1 at rates of 10C and 20C, 22.5 mAh g −1 and 50.0 mAh g −1 larger than that of LiTi 2 (PO 4 ) 3 @carbon. Moreover, LiTi 2 (PO 4 ) 3 @N-doped carbon exhibits excellent cycling performance with capacity retention of 84.3% at 5C after 1000 cycles. As verified, the well-proportioned N-doped carbon layer could reduce charge transfer resistance and improve electrical conductivity. The loose nanoporous structure could shorten pathway and facilitate diffusion for Li ion. Therefore, LiTi 2 (PO 4 ) 3 @N-doped carbon gets the superior electrochemical properties benefiting from those two characteristics.

  8. /sup 210/Po in the western Indian Ocean: Distributions, disequilibria and partitioning between the dissolved and particulate phases

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Y.; Finkel, R.

    1988-05-01

    Seven GEOSECS stations in the western Indian Ocean were measured for dissolved /sup 210/Po, and five of these were also measured for particulate /sup 210/Po. Dissolved phase /sup 210/Po is lower than /sup 210/Pb in the deep water north of Madagascar, with values in the Arabian Sea being lower by about 4 dpm/100 kg (approx. = 30%) for almost the entire water column. South of Madagascar, /sup 210/Po is essentially in equilibrium with /sup 210/Pb in the deep water, but with /sup 210/Po excess in subsurface water south of the Crozet basin. In the benthic boundary layer, /sup 210/Po is consistently lower than /sup 210/Pb for all the stations. In the particulate phase /sup 210/Po shows a general increase with depth and is highest in the benthic boundary layer. In general, /sup 210/Po is lower than /sup 210/Pb in the particulate phase, but at the one Somali basin station where data are available, deep water /sup 210/Po is systematically higher than /sup 210/Pb. A mid-depth maximum of particulate /sup 210/Pb is generally associated with that of dissolved /sup 210/Pb. The partition of /sup 210/Po between the particulate and dissolved phases is not significantly different from that of /sup 210/Pb. The activities of the two nuclides in the particulate phase are generally less than 10% of those in the dissolved phase. The range is from 1% to 60%. High particulate and low dissolved activities are observed in the deep water, especially in the benthic boundary layer.

  9. Effect of synthesizing method on the properties of LiFePO4/C composite for rechargeable lithium-ion batteries

    Science.gov (United States)

    Yoon, Man-Soon; Islam, Mobinul; Park, Young Min; Ur, Soon-Chul

    2013-03-01

    Olivine-type LiFePO4/C cathode materials are fabricated with FePO4 powders that are pre-synthesized by two different processes from iron chloride solution. Process I is a modified precipitation method which is implemented by the pH control of a solution using NH4OH to form FePO4 precipitates at room temperature. Process II is a conventional precipitation method, of which H3PO4 (85%) solution is gradually added to a FeCl3 solution during the process to maintain a designated mole ratio. The solution is subsequently aged at 90°C in a water bath until FePO4 precipitates appear. In order to synthesize LiFePO4/C composites, each batch of FePO4 powders is then mixed with pre-milled lithium carbonate and glucose (8 wt. %) as a carbon source in a ball-mill. The structural characteristics of both LiFePO4/C composites fabricated using iron phospates from two different routes have been examined employing XRD and SEM. The modified precipitation process is considered to be a relatively simple and effective process for the preparation of LiFePO4/C composites owing to their excellent electrochemical properties and rate capabilities.

  10. Three-dimensional graphene/LiFePO4 nanostructures as cathode materials for flexible lithium-ion batteries

    International Nuclear Information System (INIS)

    Ding, Y.H.; Ren, H.M.; Huang, Y.Y.; Chang, F.H.; Zhang, P.

    2013-01-01

    Graphical abstract: Graphene/LiFePO 4 composites as a high-performance cathode material for flexible lithium-ion batteries have been prepared by using a co-precipitation method to synthesize graphene/LiFePO4 powders as precursors and then followed by a solvent evaporation process. - Highlights: • Flexible LiFePO 4 /graphene films were prepared first time by a solvent evaporation process. • The flexible electrode exhibited a high discharge capacity without conductive additives. • Graphene network offers the electrode adequate strength to withstand repeated flexing. - Abstract: Three-dimensional graphene/LiFePO 4 nanostructures for flexible lithium-ion batteries were successfully prepared by solvent evaporation method. Structural characteristics of flexible electrodes were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM). Electrochemical performance of graphene/LiFePO 4 was examined by a variety of electrochemical testing techniques. The graphene/LiFePO 4 nanostructures showed high electrochemical properties and significant flexibility. The composites with low graphene content exhibited a high capacity of 163.7 mAh g −1 at 0.1 C and 114 mAh g −1 at 5 C without further incorporation of conductive agents

  11. Double Carbon Nano Coating of LiFePO4 Cathode Material for High Performance of Lithium Ion Batteries.

    Science.gov (United States)

    Ding, Yan-Hong; Huang, Guo-Long; Li, Huan-Huan; Xie, Hai-Ming; Sun, Hai-Zhu; Zhang, Jing-Ping

    2015-12-01

    Double carbon-coated LiFePO4 (D-LiFePO4/C) composite with sphere-like structure was synthesized through combination of co-precipitation and solid-state methods. Cetyl-trimethyl-ammonium bromide (CTAB) and citric acid served as two kinds of carbon sources in sequence. SEM images demonstrated that double carbon coating had certain influence on the morphology. The thickness of carbon coating on D-LiFePO4/C was about 1.7 nm and the content of carbon was 2.48 wt%, according to HRTEM and TG analysis. The electrochemical impedance spectroscopy analysis indicated that the D-LiFePO4/C composite presented the charge-transfer resistance of 68 Ω and Li ion diffusion coefficient of 2.68 x 10(-13) cm2 S(-1), while the single carbon-coated LiFePO4 (S-LiFePO4/C) exhibited 135.5Ω and 4.03 x 10(-14) cm2 S(-1). Especially, the prepared D-LiFePO4/C electrode showed discharge capacities of 102.9 (10C) and 87.1 (20C) mA h g(-1), respectively, with almost no capacity lost after 400 cycles at 10C, which were much better than those of S-LiFePO4/C composite.

  12. C3PO, an endoribonuclease that promotes RNAi by facilitating RISC activation.

    Science.gov (United States)

    Liu, Ying; Ye, Xuecheng; Jiang, Feng; Liang, Chunyang; Chen, Dongmei; Peng, Junmin; Kinch, Lisa N; Grishin, Nick V; Liu, Qinghua

    2009-08-07

    The catalytic engine of RNA interference (RNAi) is the RNA-induced silencing complex (RISC), wherein the endoribonuclease Argonaute and single-stranded small interfering RNA (siRNA) direct target mRNA cleavage. We reconstituted long double-stranded RNA- and duplex siRNA-initiated RISC activities with the use of recombinant Drosophila Dicer-2, R2D2, and Ago2 proteins. We used this core reconstitution system to purify an RNAi regulator that we term C3PO (component 3 promoter of RISC), a complex of Translin and Trax. C3PO is a Mg2+-dependent endoribonuclease that promotes RISC activation by removing siRNA passenger strand cleavage products. These studies establish an in vitro RNAi reconstitution system and identify C3PO as a key activator of the core RNAi machinery.

  13. Inelastic neutron scattering and lattice dynamics of AlPO4

    International Nuclear Information System (INIS)

    Mittal, R.; Chaplot, S.L.; Kulshreshtha, S.K.; Kolesnikov, A.I.; Loong, C.K.; Jayakumar, O.D.

    2005-01-01

    A semi-empirical interatomic potential in AlPO 4 , previously determined using ab initio calculations has been widely used in studying the phase transitions among various polymorphs. We report here measurements of the phonon spectrum in low-cristobalite phase of AlPO 4 using High-Resolution Medium-Energy Chopper Spectrometer at ANL, USA in the energy transfer range 0-160 MeV. The calculated phonon spectra using the available potential shows a fair agreement with the experimental data. However the agreement between the two is improved by including the polarizability of the oxygen atoms in the framework of a shell model. (author)

  14. Room-temperature synthesis and photoluminescence of hexagonal CePO4 nanorods

    Science.gov (United States)

    Zhu, J.; Zhang, K.; Zhao, H. Y.

    2018-01-01

    Hexagonal CePO4 nanorods were synthesized via a simple chemical precipitation route at room-temperature without the presence of surfactants and then characterized by powder X-ray diffraction (XRD), energy-dispersive X-ray (EDX) spectrometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption and photoluminescence (PL) spectroscopy. Hexagonal CePO4 nanorods exhibit strong ultraviolet absorption and ultraviolet luminescence, which correspond to the electronic transitions between 4f and 5d state of Ce3+ ions.

  15. An assessment of 210Pb and 210Po in terrestrial foodstuffs from regions of England and Wales

    International Nuclear Information System (INIS)

    McDonald, P.; Jackson, D.; Leonard, D.R.P.; McKay, K.

    1999-01-01

    Based on data for nationally available foodstuffs, naturally occurring 210 Pb and 210 Po contribute significantly to the UK radiation dose from dietary intake. To provide a more complete overview of radiological implications to the public, samples of offal, cereal, fruit, root and green vegetables were collected from 11 sites, including regions of potential 210 Pb and 210 Po enhancement. Considerable variability was evident in levels of 210 Pb and 210 Po from all sites and in all food types investigated. Higher concentrations were typically found in offal and cereals. Lowest concentrations were generally found in root vegetables. Between sites, the only evidence of elevated concentrations of 210 Po occurred at Helston ( 210 Po 3.0 Bq kg -1 in bovine liver, no other offal sample exceeding 0.8 Bq kg -1 ), and Holyhead 210 Po 0.4 Bq kg -1 in blackberries, no other fruit sample exceeding 0.1 Bq kg -1 ). Other foodstuffs from these sites did not show similar enhanced levels of 210 Po. The maximum dose arising from consumption of 210 Pb and 210 Po in foods surveyed in this study is estimated to be around 120 μSv year -1 to adults. This compares with an estimated UK average consumption dose from all nuclides and foodstuffs of 300 μSv year -1 (broad range 100-1000 μSv year -1 ). (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  16. Unusual 210Po/210Pb ratios in the surface water of the Gulf of Lions

    International Nuclear Information System (INIS)

    Radakovitch, O.; Heussner, S.; Cherry, R.D.; Heyraud, M.

    1998-01-01

    Concentrations of 210 Po and 210 Pb have been measured in sea water collected in the Grand Rhone Canyon. Concentrations of 210 Pb are at similar levels to those found in other Mediterranean sea water samples, and are at the levels which would be expected in comparison with global sea water data. The same applies to the 210 Po concentrations in samples from below 100 m depth. Surface samples from above 100 m have 210 Po at levels rather higher than expected, and their 210 Po/ 210 Pb ratios are about 1 or more as compared with the usual open ocean ratio 0.5. These data can be interpreted as indicating another source of supply of 210 Po to the surface layer in addition to the normal atmospheric input. We suggest that an episodic advective particulate input, probably originating in the output of the Rhone river and perhaps involving resuspension of fine particulates from the bottom sediments as a result of storm conditions, is he most likely candidate for this additional source. (authors)

  17. Phase transition and multicolor luminescence of Eu2+/Mn2+-activated Ca3(PO4)2 phosphors

    International Nuclear Information System (INIS)

    Li, Kai; Chen, Daqin; Xu, Ju; Zhang, Rui; Yu, Yunlong; Wang, Yuansheng

    2014-01-01

    Graphical abstract: We have synthesized Eu 2+ doped and Eu 2+ /Mn 2+ co-doped Ca 3 (PO 4 ) 2 phosphors. The emitting color varies from blue to green with increasing of Eu 2+ content for the Eu 2+ -doped phosphor, and the quantum yield of the 0.05Eu 2+ : Ca 2.95 (PO 4 ) 2 sample reaches 56.7%. Interestingly, Mn 2+ co-doping into Eu 2+ : Ca 3 (PO 4 ) 2 leads to its phase transition from orthorhombic to rhombohedral, and subsequently generates tunable multi-color luminescence from green to red via Eu 2+ → Mn 2+ energy transfer. - Highlights: • A series of novel Eu 2+ : Ca 3 (PO 4 ) 2 phosphors were successfully synthesized. • Phase transition of Ca 3 (PO 4 ) 2 from orthorhombic to rhombohedral occurred when Mn 2+ ions were doped. • The phosphors exhibited tunable multi-color luminescence. • The quantum yield of 0.05Eu 2+ : Ca 2.95 (PO 4 ) 2 phosphor can reach 56.7%. • The analyses of phosphors were carried out by many measurements. - Abstract: Intense blue-green-emitting Eu 2+ : Ca 3 (PO 4 ) 2 and tunable multicolor-emitting Eu 2+ /Mn 2+ : Ca 3 (PO 4 ) 2 phosphors are prepared via a solid-state reaction route. Eu 2+ -doped orthorhombic Ca 3 (PO 4 ) 2 phosphor exhibits a broad emission band in the wavelength range of 400–700 nm with a maximum quantum yield of 56.7%, and the emission peak red-shifts gradually from 479 to 520 nm with increase of Eu 2+ doping content. Broad excitation spectrum (250–420 nm) of Eu 2+ : Ca 3 (PO 4 ) 2 matches well with the near-ultraviolet LED chip, indicating its potential applications as tri-color phosphors in white LEDs. Interestingly, Mn 2+ co-doping into Eu 2+ : Ca 3 (PO 4 ) 2 leads to its phase transition from orthorhombic to rhombohedral, and subsequently generates tunable multi-color luminescence from green to red via Eu 2+ → Mn 2+ energy transfer, under 365 nm UV lamp excitation

  18. Temperature effect on uranium retention onto Zr2O(PO4)2 surface

    International Nuclear Information System (INIS)

    Almazan Torres, M.G.

    2007-03-01

    Uranium sorption onto Zr 2 O(PO 4 ) 2 has been studied between 298 K and 363 K, in 0.1 M NaClO 4 medium. Potentiometric titrations were realized to determine temperature dependency of the acid-base properties (pH(pcn), acidity constants). Classical batch experiments were performed at different temperatures. The sorption experiments revealed that the uranium sorption onto Zr 2 O(PO 4 ) 2 is favoured with the temperature. Structural characterization of the surface complexes was performed by both Time-Resolved Laser-Induced Fluorescence (TRLIF) and EXAFS spectroscopy. The TRLIF measurements vs. temperature revealed two uranyl surface complexes. No influence of the temperature onto the nature surface complex was observed. The EXAFS analysis showed a splitting of the equatorial oxygen atoms in two shells, corresponding to uranyl bidentate, inner-sphere complexes. The obtained structural uranyl surface complex information was used to simulate (using a constant capacitance model) the sorption edges. The proposed complexes equilibrium model consists of the following surface complexes: (ZrOH) 2 UO 2 2+ and (PO) 2 UO 2 . Besides the stability constants for the surface complexes, the thermodynamic parameters ΔH 0 and ΔS 0 were determined using the van't Hoff equation. The enthalpy values associated to the U(VI) retention onto Zr 2 O(PO 4 ) 2 , determined by the temperature dependence of the stability constants, testify that the formation of the complex (PO) 2 UO 2 (55 kJ/mol) is endothermic, while no influence of the temperature was observed for the formation of the complex (ZrOH) 2 UO 2 2+ . The adsorption reaction of the last complex is then driven by entropy. In addition, calorimetric measurements of uranium sorption onto Zr 2 O(PO 4 ) 2 were carried out to directly quantify the enthalpy associated to the retention processes. (author)

  19. 21 CFR 862.1120 - Blood gases (PCO2, PO2) and blood pH test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood gases (PCO2, PO2) and blood pH test system... Test Systems § 862.1120 Blood gases (PCO2, PO2) and blood pH test system. (a) Identification. A blood gases (PCO2, PO2) and blood pH test system is a device intended to measure certain gases in blood, serum...

  20. Levels of lead-210 (210Pb) and polonium 210 (210Po) in Cuban Tobacco products

    International Nuclear Information System (INIS)

    Brigido, F.O.; Barrerras Caballero, A.; Alvarez Rodriguez, D.; Montalvan Estrada, A.

    1999-01-01

    The release of 210Po in tobacco smoke and the radiation dose for man have been studied because of the high incidence of lung cancer among smoker. The electroplating of polonium at two different times onto copper disks and further measurement of alpha activity was the meted used for 210 Po determination in tobacco products. The Polonium daughter is used to determine both the 210Pb and 210Po using the Baseman equations for radioactive growth and decay. A cigarette contains between 10.6 and 14.7 mBq of 210Pb with an average activity of 13.0 mBq and between 8.5 and 12.3 mBq of 210Po with an average activity of 10.4 mBq for different Cuban cigarette brands. For a person smoking a pack of 20 cigarettes a day, the values of intakes estimated range from 32 to 44 mBq for 210Pb and from 34 to 49 mBq for 210 Po with an average daily intake of 39 mBq for 210 Pb and 42 mBq for 210Po. The annual effective dose estimated due to inhalation of these nuclides contained in cigarette smoke shows a value of 66[Sv and was in correspondence with world-wide range dose, 46 - 90 mSv.year 1 - for tobacco product consumption

  1. Levels and transfer of {sup 210}Po and {sup 210}Pb in Nordic terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J.E., E-mail: justin.brown@nrpa.n [Norwegian Radiation Protection Authority, PO Box 55, N-1332, Osteras (Norway); Gjelsvik, R. [Norwegian Radiation Protection Authority, PO Box 55, N-1332, Osteras (Norway); Roos, P. [RISO-DTU P.O. Box 49 DK-4000 Roskilde (Denmark); Kalas, J.A. [Norwegian Institute for Nature Research (NINA), Tungasletta 2, 7485 Trondheim (Norway); Outola, I. [STUK, Laippatie 4/P.O. BOX 14, 00881 Helsinki (Finland); Holm, E. [Norwegian Radiation Protection Authority, PO Box 55, N-1332, Osteras (Norway)

    2011-05-15

    Recent developments regarding environmental impact assessment methodologies for radioactivity have precipitated the need for information on levels of naturally occurring radionuclides within and transfer to wild flora and fauna. The objectives of this study were therefore to determine activity concentrations of the main dose forming radionuclides {sup 210}Po and {sup 210}Pb in biota from terrestrial ecosystems thus providing insight into the behaviour of these radioisotopes. Samples of soil, plants and animals were collected at Dovrefjell, Central Norway and Olkiluoto, Finland. Soil profiles from Dovrefjell exhibited an approximately exponential fall in {sup 210}Pb activity concentrations from elevated levels in humus/surface soils to 'supported' levels at depth. Activity concentrations of {sup 210}Po in fauna (invertebrates, mammals, birds) ranged between 2 and 123 Bq kg{sup -1} d.w. and in plants and lichens between 20 and 138 Bq kg{sup -1} d.w. The results showed that soil humus is an important reservoir for {sup 210}Po and {sup 210}Pb and that fauna in close contact with this media may also exhibit elevated levels of {sup 210}Po. Concentration ratios appear to have limited applicability with regards to prediction of activity concentrations of {sup 210}Po in invertebrates and vertebrates. Biokinetic models may provide a tool to explore in a more mechanistic way the behaviour of {sup 210}Po in this system.

  2. 210Po concentration in Perna perna mussels: looking for radiation effects

    International Nuclear Information System (INIS)

    Godoy, J.M.; Oliveira, Monica S. de; Almeida, Carlos Eduardo B. de; Carvalho, Zenildo L. de; Silva, Eliza R. da; Fernandes, Flavio da Costa; Pitanga, Fernanda L.; Danelon, Olga M.

    2008-01-01

    Twenty ropes with 400 Perna perna mussels seeds (3 cm shell size) were set-up on floating structures at Cabo Frio Island, Arraial do Cabo, approximately 100 km northeast of Rio de Janeiro city. A rope was taken out on a monthly basis, and the shell sizes of 100 seeds were measured. The haemolymph of 10 male and 10 female individuals was taken, and the same individuals were separated for 210 Po/ 210 Pb determination. After one year of monthly sampling, no clear correlation was observed between the 210 Po concentration, mussel's age and weight. A mean 210 Po concentration of 155 Bq kg -1 wet weight basis, was obtained, which is comparable with data reported in the literature. The radiation dose did not have any observable effect on the micronuclei frequency and DNA breaks in the mussels. This was probably due to the low dose rate, 0.02 mGy d -1 , in comparison with the suggested potential dose limit of 10 mGy d -1

  3. Biomimetic synthesis and characterization of the positive electrode material LiFePO4

    International Nuclear Information System (INIS)

    Li Peng; He Wen; Zhao Hongshi; Wang Shaopeng

    2009-01-01

    The biosurfactant is used as the template to synthesize lithium iron phosphate (LiFePO 4 ) precursor with the co-precipitation method and the microwave sintering method is used to prepare positive electrode material LiFePO 4 for the lithium ion battery. By using the Brunauer-Emmett-Teller (BET) surface areas, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and conductometer, the authors explored the influence of the microwave power on the structure and performance of the materials. The results the authors got have proved that good crystal and high conductivity values can be obtained from the LiFePO 4 powders which are processed 10 min under the microwave power of 300 W

  4. Model analysis of the relationship between intracellular Po2 and energy demand in skeletal muscle

    OpenAIRE

    Spires, Jessica; Gladden, L. Bruce; Grassi, Bruno; Saidel, Gerald M.; Lai, Nicola

    2012-01-01

    On the basis of experimental studies, the intracellular O2 (iPo2)-work rate (WR) relationship in skeletal muscle is not unique. One study found that iPo2 reached a plateau at 60% of maximal WR, while another found that iPo2 decreased linearly at higher WR, inferring capillary permeability-surface area (PS) and blood-tissue O2 gradient, respectively, as alternative dominant factors for determining O2 diffusion changes during exercise. This relationship is affected by several factors, including...

  5. Occurrence of 210Po and Biological Effects of Low-Level Exposure: The Need for Research

    OpenAIRE

    Seiler, Ralph L.; Wiemels, Joseph L.

    2012-01-01

    Background: Polonium-210 (210Po) concentrations that exceed 1 Bq/L in drinking-water supplies have been reported from four widely separated U.S. states where exposure to it went unnoticed for decades. The radionuclide grandparents of 210Po are common in sediments, and segments of the public may be chronically exposed to low levels of 210Po in drinking water or in food products from animals raised in contaminated areas. Objectives: We summarized information on the environmental behavior, bioki...

  6. Glucose assisted synthesis of hollow spindle LiMnPO_4/C nanocomposites for high performance Li-ion batteries

    International Nuclear Information System (INIS)

    Fu, Xiaoning; Chang, Zhaorong; Chang, Kun; Li, Bao; Tang, Hongwei; Shangguan, Enbo; Yuan, Xiao-Zi; Wang, Haijiang

    2015-01-01

    Graphical abstract: Nano-sized hollow spindle LiMnPO_4 with a well-developed olivine-type structure exhibits a high specific capacity and cycling performance. - Highlights: • A pure and well-crystallized LiMnPO_4 are synthesized via a solution-phase method. • The LiMnPO_4/C composite constitutes highly and uniformly distributed hollow spindles. • The LiMnPO_4/C composite exhibits a high specific capacity and cycling performance. • The growth process of the hollow spindle LiMnPO_4 particles is revealed. - Abstract: Nano-sized hollow spindle LiMnPO_4 with a well-developed olivine-type structure was synthesized with the assistance of glucose in dimethyl sulfoxide (DMSO)/H_2O under ambient pressure and 108 °C. The scanning electron microscopy (SEM) and transmission electron microscope (TEM) images show that the LiMnPO_4 particles consist of hollow spindles with a mean width of 200 nm, length of 500-700 nm, and wall thickness of about 30-60 nm. The LiMnPO_4/C nanocomposite was obtained by sintering nano-sized LiMnPO_4 with glucose at 650 °C under an inert atmosphere for 4 h. With a coated carbon thickness of about 10 nm, the obtained composite maintained the morphology and size of the hollow spindle. The electrochemical tests show the specific capacity of LiMnPO_4/C nanocomposite is 161.8 mAh g"−"1 at 0.05C, 137.7 mAh g"−"1 at 0.1C and 110.8 mAh g"−"1 at 0.2 C. The retention of discharge capacity maintains 92% after 100 cycles at 0.2 C. After different rate cycles the high capacity of the LiMnPO_4/C nanocomposite can be recovered. This high performance is attributed to the composite material's hollow spindle structure, which facilitates the electrolyte infiltration, resulting in an increased solid-liquid interface. The carbon layer covering the hollow spindle also contributes to the high performance of the LiMnPO_4/C material as the carbon layer improves its electronic conductivity and the nano-scaled wall thickness decreases the paths of Li

  7. Prolonged triglyceride storage in macrophages: pHo trumps pO2 and TLR4.

    Science.gov (United States)

    Lu, Mingfang; Kho, Terry; Munford, Robert S

    2014-08-01

    Lipid-laden macrophages contribute to pathologies as diverse as atherosclerosis and tuberculosis. Three common stimuli are known to promote macrophage lipid storage: low tissue oxygen tension (pO2), low extracellular pH (pHo), and exposure to agonists such as bacterial LPS. Noting that cells responding to low pO2 or agonistic bacterial molecules often decrease pHo by secreting lactic and other carboxylic acids, we studied how pHo influences the stimulation of triacylglycerol (TAG) storage by low pO2 and LPS. We found that TAG retention after incubation for 48-72 h was inversely related to pHo when primary macrophages were cultured in 21% oxygen, 4% oxygen, or with LPS at either oxygen concentration. Maintaining pHo at ~7.4 was sufficient to prevent the increase in prolonged TAG storage induced by either low pO2 or LPS. The strong influence of pHo on TAG retention may explain why lipid-laden macrophages are found in some tissue environments and not in others. It is also possible that other long-term cellular changes currently attributed to low pO2 or bacterial agonists may be promoted, at least in part, by the decrease in pHo that these stimuli induce.

  8. Relaxation-Induced Memory Effect of LiFePO4 Electrodes in Li-Ion Batteries.

    Science.gov (United States)

    Jia, Jianfeng; Tan, Chuhao; Liu, Mengchuang; Li, De; Chen, Yong

    2017-07-26

    In Li-ion batteries, memory effect has been found in several commercial two-phase materials as a voltage bump and a step in the (dis)charging plateau, which delays the two-phase transition and influences the estimation of the state of charge. Although memory effect has been first discovered in olivine LiFePO 4 , the origination and dependence are still not clear and are critical for regulating the memory effect of LiFePO 4 . Herein, LiFePO 4 has been synthesized by a home-built spray drying instrument, of which the memory effect has been investigated in Li-ion batteries. For as-synthesized LiFePO 4 , the memory effect is significantly dependent on the relaxation time after phase transition. Besides, the voltage bump of memory effect is actually a delayed voltage overshooting that is overlaid at the edge of stepped (dis)charging plateau. Furthermore, we studied the kinetics of LiFePO 4 electrode with electrochemical impedance spectroscopy (EIS), which shows that the memory effect is related to the electrochemical kinetics. Thereby, the underlying mechanism has been revealed in memory effect, which would guide us to optimize two-phase electrode materials and improve Li-ion battery management systems.

  9. Advanced carbon materials/olivine LiFePO4 composites cathode for lithium ion batteries

    Science.gov (United States)

    Gong, Chunli; Xue, Zhigang; Wen, Sheng; Ye, Yunsheng; Xie, Xiaolin

    2016-06-01

    In the past two decades, LiFePO4 has undoubtly become a competitive candidate for the cathode material of the next-generation LIBs due to its abundant resources, low toxicity and excellent thermal stability, etc. However, the poor electronic conductivity as well as low lithium ion diffusion rate are the two major drawbacks for the commercial applications of LiFePO4 especially in the power energy field. The introduction of highly graphitized advanced carbon materials, which also possess high electronic conductivity, superior specific surface area and excellent structural stability, into LiFePO4 offers a better way to resolve the issue of limited rate performance caused by the two obstacles when compared with traditional carbon materials. In this review, we focus on advanced carbon materials such as one-dimensional (1D) carbon (carbon nanotubes and carbon fibers), two-dimensional (2D) carbon (graphene, graphene oxide and reduced graphene oxide) and three-dimensional (3D) carbon (carbon nanotubes array and 3D graphene skeleton), modified LiFePO4 for high power lithium ion batteries. The preparation strategies, structure, and electrochemical performance of advanced carbon/LiFePO4 composite are summarized and discussed in detail. The problems encountered in its application and the future development of this composite are also discussed.

  10. Microwave synthesis of molybdenum doped LiFePO4/C and its electrochemical studies.

    Science.gov (United States)

    Naik, Amol; P, Sajan C

    2016-05-10

    A Mo-doped LiFePO4 composite was prepared successfully from an iron carbonyl complex by adopting a facile and rapid microwave assisted solid state method. The evolution of gases from the iron precursor produces a highly porous product. The formation and substitution of Mo in LiFePO4 were confirmed by X-ray diffraction; surface analysis was carried out by scanning electron microscopy, field emission scanning electron microscopy, and transmission electron microscopy. The electrochemical properties of the substituted LiFePO4 were examined by cyclic voltammetry, electrochemical impedance spectroscopy and by recording charge-discharge cycles. It was observed that the as prepared composites consisted of a single phase orthorhombic olivine-type structure, where Mo(6+) was successfully introduced into the M2(Fe) sites. Incorporation of supervalent Mo(6+) introduced Li(+) ion vacancies in LiFePO4. The synthesized material facilitated lithium ion diffusion during charging/discharging due to the charge compensation effect and porosity. The battery performance studies showed that LiMo0.05Fe0.095PO4 exhibited a maximum capacity of 169.7 mA h g(-1) at 0.1 C current density, with admirable stability retention. Even at higher current densities, the retention of the specific capacity was exceptional.

  11. A study on the 210Po distribution in marine organisms around the coastal waters of Mumbai Harbour Bay

    International Nuclear Information System (INIS)

    Hemalatha, P.; Preetha, J.; Madhuparna, D.; Narayani, K.; Vandana, P.; Ravi, P.M.

    2013-01-01

    The near-shore environment and the surface oceans are very reactive zones with heavy geochemical and biological activity. Among the natural radionuclide, Po assumes importance as it is a good representative isotope of naturally occurring radionuclide present in the sea water which is particle reactive and high-energy alpha emitter. The source of Po is mainly from the diffusion of 222 Rn gas from its parent 238 U decay product 226 Ra. 210 Po gets accumulated in very high level in organisms and thus becomes responsible for the internal radiation dose to human. The main path for entry of the activity into human-is through consumption of marine food. This paper presents the results on the study conducted to investigate the 210 Po accumulation in the marine organism around Mumbai. The results were compared with 210 Po activity in representative marine organisms from eastern and western coastal India. Twelve different varieties of marine organisms (Fish, Crab, Prawns) consumed by the local population were collected from the catch at the shore and from the local fish markets. 210 Po was estimate in the organisms and in the sea water by standard radiochemical analysis. The edible portion of the organism were separated, freeze dried, acid digested at controlled temperature of 90℃ and the residue was extracted in 0.5M HCI. 210 Po in sea water was concentrated using Fe(OH) 3 scavenging followed by extraction by 0.5M HCI. Po was further separated from the acid extract by spontaneous deposition on to a Ag disk at 80℃. Alpha activity in the deposited sample was estimated using Alpha spectrometry. 208 Po and 209 Po tracers were used as yield monitor. 210 Po was observed to be in the range of <0.008-8.39 Bq.kg -1 in fish varieties. In prawns, activity was in the range of <0.008-1.41 Bq.kg -1 . Bioaccumulation factor was calculated and the values were compared with the IAEA reported values and discussed. (author)

  12. Synthesis of LiFePO{sub 4}/C cathode material from ferric oxide and organic lithium salts

    Energy Technology Data Exchange (ETDEWEB)

    Shi Zhongqi; Huang Ming [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041 (China); Graduate School of Chinese Academy of Sciences, Beijing, 100039 (China); Huai Yongjian [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041 (China); Graduate School of Chinese Academy of Sciences, Beijing, 100039 (China); China Aviation Lithium Battery Co., Ltd, Luoyang, Henan 471003 (China); Lin Ziji; Yang Kerun [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041 (China); Graduate School of Chinese Academy of Sciences, Beijing, 100039 (China); Hu Xuebu [Department of Chemistry and Materials, Sichuan Normal University, Chengdu, Sichuan 610068 (China); Zhongke Laifang Power Science and Technology Co., Ltd., Chengdu, Sichuan 610041 (China); Deng Zhenghua, E-mail: zhdeng@cioc.ac.c [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041 (China); Graduate School of Chinese Academy of Sciences, Beijing, 100039 (China); Zhongke Laifang Power Science and Technology Co., Ltd., Chengdu, Sichuan 610041 (China)

    2011-04-15

    Research highlights: {yields} LiFePO{sub 4} can be synthesized from Fe{sub 2}O{sub 3} by a sequence of free-radical reactions. {yields} Organic lithium salts can avoid the composition segregation of the precursor. {yields} Low cost ferric oxide and environmentally friendly distilled water are used. - Abstract: LiFePO{sub 4}/C cathode material has been simply synthesized via a modified in situ solid-state reaction route using the raw materials of Fe{sub 2}O{sub 3}, NH{sub 4}H{sub 2}PO{sub 4}, Li{sub 2}C{sub 2}O{sub 4} and lithium polyacrylate (PAALi). The sintering temperature of LiFePO{sub 4}/C precursor is studied by thermo-gravimetric (TG)/differential thermal analysis (DTA). The physical properties of LiFePO{sub 4}/C are then investigated through analysis using by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and the electrochemical properties are investigated by electrochemical impedance spectra (EIS), cyclic voltammogram (CV) and constant current charge/discharge test. The LiFePO{sub 4}/C composite with the particle size of {approx}200 nm shows better discharge capacity (156.4 mAh g{sup -1}) than bare LiFePO{sub 4} (52.3 mAh g{sup -1}) at 0.2 C due to the improved electronic conductivity which is demonstrated by EIS. The as-prepared LiFePO{sub 4}/C through this method also shows excellent high-rate characteristic and cycle performance. The initial discharge capacity of the sample is 120.5 mAh g{sup -1} and the capacity retention rate is 100.6% after 50 cycles at 5 C rate. The results prove that the using of organic lithium salts can obtain a high performance LiFePO{sub 4}/C composite.

  13. Synthesis and photoluminescence of Eu3+ and Mn2+ doped double phosphates KMLa(PO4)2 (M = Zn, Mg)

    International Nuclear Information System (INIS)

    Pan Yuexiao; Zhang Qinyuan; Jiang Zhonghong

    2006-01-01

    Two compounds, KMgLa(PO 4 ) 2 and KZnLa(PO 4 ) 2 doped with Eu 3+ and Mn 2+ ions, have been synthesized by a conventional solid-state method at 850 deg. C. Structures of KMgLa(PO 4 ) 2 and KZnLa(PO 4 ) 2 have been investigated and confirmed by X-ray diffraction and photoluminescence spectra. The results indicate that the compounds have remained the monoclinic structure of LaPO 4 with space group of C s when (K + , Mg 2+ ) or (K + , Zn 2+ ) could substitute half of the La 3+ ions. Under an ultraviolet source, KMgLa(PO 4 ) 2 :Mn 2+ has shown a bright red phosphorescent color, while KZnLa(PO 4 ) 2 :Mn 2+ has shown an orange-red emission which is assigned to the electronic transition of 4 T 1 ( 4 G)- 6 A 1 ( 6 S) of Mn 2+ in strong crystal field

  14. Structure determination, electronic and optical properties of rubidium holmium polyphosphate RbHo(PO3)4

    Science.gov (United States)

    Zhu, Jing; Chen, Hui; Wang, Yude; Guan, Hongtao; Xiao, Xuechun

    2012-12-01

    Structural, optical, and electronic properties of a new alkali metal-rare earth polyphosphate, RbHo(PO3)4, have been investigated by means of single-crystal X-ray diffraction, power X-ray diffraction, elemental analysis, and spectral measurement. RbHo(PO3)4 crystallizes in the monoclinic with space group P21/n and Z = 4. It is described as a three-dimensional (3D) architecture built up of PO4 double spiral chains and HoO8 polyhedra by corner-sharing. The 11-coordinated rubidium atoms are located in infinite tunnels. Additionally, in order to gain further insight into the relationship between property and structure of RbHo(PO3)4, theoretical calculation based on the density functional theory (DFT) was performed using the total-energy code CASTEP.

  15. Neodymium-doped Sr5(PO4)3F and Sr5(VO4)3F

    International Nuclear Information System (INIS)

    Corker, D.L.; Nicholls, J.; Loutts, G.B.

    1995-01-01

    Neodymium-doped Sr 5 (PO 4 ) 3 F [neodymium strontium fluoride phosphate, (Nd,Sr) 5 (PO 4 ) 3 F] and neodymium-doped Sr 5 (VO 4 ) 3 F [neodymium strontium fluoride vanadate, (Nd,Sr) 5 (VO 4 ) 3 F] crystallize in space group P6 3 /m and are isostructural with calcium fluorophosphate, Ca 5 (PO 4 ) 3 F. There are two different Sr sites in Sr 5 (XO 4 ) 3 F, denoted Sr(1) and Sr(2). Using single-crystal X-ray diffraction the two structures were refined to R factors of 2.3 and 2.2%, respectively, showing that Nd is present at both Sr sites in (Sr,Nd) 5 (VO 4 ) 3 F but only at the Sr(2) site in (Sr,Nd) 5 (PO 4 ) 3 F. (orig.)

  16. Evidence for a pressure-induced spin transition in olivine-type LiFePO4 triphylite

    Science.gov (United States)

    Núñez Valdez, Maribel; Efthimiopoulos, Ilias; Taran, Michail; Müller, Jan; Bykova, Elena; McCammon, Catherine; Koch-Müller, Monika; Wilke, Max

    2018-05-01

    We present a combination of first-principles and experimental results regarding the structural and magnetic properties of olivine-type LiFePO4 under pressure. Our investigations indicate that the starting P b n m phase of LiFePO4 persists up to 70 GPa. Further compression leads to an isostructural transition in the pressure range of 70-75 GPa, inconsistent with a former theoretical study. Considering our first-principles prediction for a high-spin to low-spin transition of Fe2 + close to 72 GPa, we attribute the experimentally observed isostructural transition to a change in the spin state of Fe2 + in LiFePO4. Compared to relevant Fe-bearing minerals, LiFePO4 exhibits the largest onset pressure for a pressure-induced spin state transition.

  17. Carbon coatings with olive oil, soybean oil and butter on nano-LiFePO 4

    Science.gov (United States)

    Kim, Ketack; Jeong, Ji Hwa; Kim, Ick-Jun; Kim, Hyun-Soo

    Kitchen oils (olive, soybean and butter) are selected for carbon coatings on LiFePO 4. The surface properties of LiFePO 4 are unknown or vary depending on synthetic methods. The multi-functional groups of fatty acids in the oils can orient properly to cope with the variable surface properties of LiFePO 4, which can lead to dense carbon coatings. The low price and low toxicity of kitchen oils are other advantages of the coating process. LiFePO 4 (D 50 = 121 nm)combined with the carbon coating enhances the rate capability. Capacities at the 2 C rate reach 150 mAh g -1 or higher. The charge retention values of 2.0 C/0.2 C are between 94.4 and 98.9%.

  18. Synthesis and electrochemical properties of olivine LiFePO{sub 4} prepared by a carbothermal reduction method

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hui-ping; Wang, Zhi-xing; Li, Xin-hai; Guo, Hua-jun; Peng, Wen-jie; Zhang, Yun-he; Hu, Qi-yang [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China)

    2008-10-01

    LiFePO{sub 4}/C composite cathode material was prepared by carbothermal reduction method, which uses NH{sub 4}H{sub 2}PO{sub 4}, Li{sub 2}CO{sub 3} and cheap Fe{sub 2}O{sub 3} as starting materials, acetylene black and glucose as carbon sources. The precursor of LiFePO{sub 4}/C was characterized by differential thermal analysis and thermogravimetry. X-ray diffraction (XRD), scanning electron microscopy (SEM) micrographs showed that the LiFePO{sub 4}/C is olivine-type phase, and the addition of the carbon reduced the LiFePO{sub 4} grain size. The carbon is dispersed between the grains, ensuring a good electronic contact. The products sintered at 700 C for 8 h with glucose as carbon source possessed excellent electrochemical performance. The synthesized LiFePO{sub 4} composites showed a high electrochemical capacity of 159.3 mAh g{sup -1} at 0.1C rate, and the capacity fading is only 2.2% after 30 cycles. (author)

  19. Improved GO/PO method and its application to wideband SAR image of conducting objects over rough surface

    Science.gov (United States)

    Jiang, Wang-Qiang; Zhang, Min; Nie, Ding; Jiao, Yong-Chang

    2018-04-01

    To simulate the multiple scattering effect of target in synthetic aperture radar (SAR) image, the hybrid method GO/PO method, which combines the geometrical optics (GO) and physical optics (PO), is employed to simulate the scattering field of target. For ray tracing is time-consuming, the Open Graphics Library (OpenGL) is usually employed to accelerate the process of ray tracing. Furthermore, the GO/PO method is improved for the simulation in low pixel situation. For the improved GO/PO method, the pixels are arranged corresponding to the rectangular wave beams one by one, and the GO/PO result is the sum of the contribution values of all the rectangular wave beams. To get high-resolution SAR image, the wideband echo signal is simulated which includes information of many electromagnetic (EM) waves with different frequencies. Finally, the improved GO/PO method is used to simulate the SAR image of targets above rough surface. And the effects of reflected rays and the size of pixel matrix on the SAR image are also discussed.

  20. Synthesis, crystal structure and electrochemical properties of the manganese-doped LiNaFe[PO{sub 4}]F materials

    Energy Technology Data Exchange (ETDEWEB)

    Ben Yahia, Hamdi, E-mail: benyahia.hamdi@aist.go.jp; Shikano, Masahiro, E-mail: shikano.masahiro@aist.go.jp; Sakaebe, Hikari; Kobayashi, Hironori

    2013-08-15

    The new compounds LiNaFe{sub 1−x}Mn{sub x}[PO{sub 4}]F (x ≤ 1/4) were synthesized by a solid state reaction route. The crystal structure of LiNaFe{sub 3/4}Mn{sub 1/4}[PO{sub 4}]F was determined from single crystal X-ray diffraction data. LiNaFe{sub 3/4}Mn{sub 1/4}[PO{sub 4}]F crystallizes with the Li{sub 2}Ni[PO{sub 4}]F-type structure, space group Pnma, a = 10.9719(13), b = 6.3528(7), c = 11.4532(13) Å, V = 798.31(16) Å{sup 3}, and Z = 8. The structure consists of edge-sharing (Fe{sub 3/4}Mn{sub 1/4})O{sub 4}F{sub 2} octahedra forming (Fe{sub 3/4}Mn{sub 1/4})FO{sub 3} chains running along the b-axis. These chains are interlinked by PO{sub 4} tetrahedra forming a three-dimensional framework with the tunnels and the cavities filled by the well-ordered sodium and lithium atoms, respectively. The manganese-doped phases show poor electrochemical behavior comparing to the iron pure phase LiNaFe[PO{sub 4}]F. - Highlights: • We investigated the synthesis of LiNaFe{sub 1−x}Mn{sub x}[PO{sub 4}]F by solid state reaction. • We demonstrated that a solid solution exist only for x ≤ 1/4. • We solved the crystal structure of LiNaFe{sub 3/4}Mn{sub 1/4}[PO{sub 4}]F using single crystal data. • We studied the electrochemical performances of LiNaFe{sub 1−x}Mn{sub x}[PO{sub 4}]F. • The Mn-doped phases have poor electrochemical performances comparing to LiNaFe[PO{sub 4}]F.

  1. Properties–structure relationship research on LiCaPO4:Eu2+ as blue phosphor for NUV LED application

    International Nuclear Information System (INIS)

    Zhang, Xinguo; Mo, Fuwang; Zhou, Liya; Gong, Menglian

    2013-01-01

    Graphical abstract: The graphical abstract shows the excitation and emission spectrum of LiCaPO 4 :Eu 2+ , and the CIE coordinates of LiCaPO 4 :Eu 2+ . The inset shows the photo of blue LED prepared by LiCaPO 4 :Eu 2+ and NUV chip. It indicates that this phosphor can be excited by UV light and emit strong greenish-blue light. Highlights: •Pure phase blue phosphors of LiCaPO 4 :Eu 2+ with a hexagonal structure were first prepared via solid-state method. •The crystallographic site of Eu 2+ ion in the LiCaPO 4 lattice was identified as 8-fold Ca 2+ site. •The phosphor exhibits excellent thermal stability and the corresponding mechanism was thermal assisted ionization. •Bright and high color purity blue LED prototype based on LiCaPO 4 :Eu 2+ phosphor was fabricated. -- Abstract: Blue-emitting phosphors of Eu 2+ -activated LiCaPO 4 with a hexagonal structure were prepared via a conventional solid-state method. The XRD, PL spectra and thermal quenching were applied to characterize the phosphors. The crystallographic site of Eu 2+ ion in the LiCaPO 4 lattice was identified and discussed. The optimized LiCaPO 4 :0.03Eu 2+ exhibits the bright greenish-blue emission with CIE coordinates of (0.119, 0.155) and a quantum efficiency of 52%. The critical energy-transfer distance was confirmed as ∼18 Å by both calculated crystal structure method and experimental spectral method. The thermal stability of LiCaPO 4 :Eu 2+ was evaluated by temperature-dependent PL spectra, and the thermal quenching mechanism was found to be thermal assisted ionization. Prototype blue LEDs with high color purity and good current stability were fabricated

  2. Determination of 210Po in tea, mat and their infusions and its annual intake by Syrians

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Nashawati, A.; Amin, Y.; Al-Akel, B.

    2004-01-01

    Polonium-210 was determined in 34 kinds of imported tea and 9 kinds of mat collected from the Syrian local market. The 210 Po concentration was found to vary from 5.5 to 39 Bq x kg -1 and 47 to 82 Bq x kg -1 in tea and mat samples, respectively. In addition 210 Po was also determined in tea and mat infusions where different infusion conditions have been examined: amount, temperature and infusion time. The results have shown that the amount of 210 Po transferred from tea and mat leaves to the aqueous extract ranged from 9 to 21% and 3 to 15%, respectively. The annual intake of 210 Po by Syrians due to tea consumption and mat infusions was calculated and found to be 9 Bq and 151 Bq for tea and mat respectively: washing of mat with warm water is recommended before preparation the infusions to decrease the annual intake of 210 Po. (author)

  3. Accelerated Removal of Fe-Antisite Defects while Nanosizing Hydrothermal LiFePO4 with Ca(2).

    Science.gov (United States)

    Paolella, Andrea; Turner, Stuart; Bertoni, Giovanni; Hovington, Pierre; Flacau, Roxana; Boyer, Chad; Feng, Zimin; Colombo, Massimo; Marras, Sergio; Prato, Mirko; Manna, Liberato; Guerfi, Abdelbast; Demopoulos, George P; Armand, Michel; Zaghib, Karim

    2016-04-13

    Based on neutron powder diffraction (NPD) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), we show that calcium ions help eliminate the Fe-antisite defects by controlling the nucleation and evolution of the LiFePO4 particles during their hydrothermal synthesis. This Ca-regulated formation of LiFePO4 particles has an overwhelming impact on the removal of their iron antisite defects during the subsequent carbon-coating step since (i) almost all the Fe-antisite defects aggregate at the surface of the LiFePO4 crystal when the crystals are small enough and (ii) the concomitant increase of the surface area, which further exposes the Fe-antisite defects. Our results not only justify a low-cost, efficient and reliable hydrothermal synthesis method for LiFePO4 but also provide a promising alternative viewpoint on the mechanism controlling the nanosizing of LiFePO4, which leads to improved electrochemical performances.

  4. Carbonate anion controlled growth of LiCoPO4/C nanorods and its improved electrochemical behavior

    International Nuclear Information System (INIS)

    Gangulibabu; Nallathamby, Kalaiselvi; Meyrick, Danielle; Minakshi, Manickam

    2013-01-01

    Highlights: ► Carbonate anion controlled growth of LiCoPO 4 nanorods has been prepared. ► Mixture of H 2 CO 3 + (NH 4 ) 2 CO 3 increases the CO 3 2− concentration and acts as an effective growth inhibitor. ► Heating the carbonate rich precursor in an inert atmosphere produces a Co 2 P phase that is conductive. ► Addition of super P carbon resulted in an amorphous carbon coating on LiCoPO 4 particles. ► LiCoPO 4 /C nanorods with a co-existence of Co 2 P exhibit excellent discharge capacity with retention on multiple cycling. -- Abstract: LiCoPO 4 /C nanocomposite with growth controlled by carbonate anions was synthesized via a unique solid-state fusion method. Carbonate anions in the form of H 2 CO 3 or a mixture of H 2 CO 3 + (NH 4 ) 2 CO 3 have been used as a growth inhibiting modifier to produce morphology controlled lithium cobalt phosphate. The presence of cobalt phosphide (Co 2 P) as a second phase improved the conductivity and electrochemical properties of the parent LiCoPO 4. The formation of Co 2 P is found to be achievable only in an inert atmosphere. Super P ® carbon (10 wt.%) provided an adherent carbon coating on pristine LiCoPO 4 resulting in the LiCoPO 4 /C composite cathode. This electrode exhibited enhanced electrochemical properties: capacity of 123 mAh g −1 with excellent capacity retention of 89% after 30 cycles, and reasonable rate capability of up to 5 C rate. The synergistic effect of carbonate anions and formation of Co 2 P under inert atmosphere has influenced the electrochemical behavior of LiCoPO 4 /C cathode through controlling the morphology and increasing the conductivity

  5. Microwave-assisted hydrothermal synthesis of CePO4 nanostructures: Correlation between the structural and optical properties

    International Nuclear Information System (INIS)

    Palma-Ramírez, D.; Domínguez-Crespo, M.A.; Torres-Huerta, A.M.; Dorantes-Rosales, H.; Ramírez-Meneses, E.; Rodríguez, E.

    2015-01-01

    Highlights: • An enhancement in the hydrothermal synthesis for obtaining of CePO 4 is presented. • Microwave energy can replace the energy by convection for obtaining CePO 4 . • CePO 4 demonstrates to be an option to increase the optical properties of polymers. • Adjusting the pH, the sintering process is not necessary to obtain the desire phase. • CePO 4 morphologies undergo evolution from nanorods to semispherical nanoparticles. - Abstract: In this work, the microwave-assisted hydrothermal method is proposed as an alternative to the synthesis of cerium phosphate (CePO 4 ) nanostructures to evaluate the influence of different synthesis parameters on both the structural and optical properties. In order to reach this goal, two different sets of experiments were designed, varying the reaction temperature (130 and 180 °C), synthesis time (15 and 30 min) and sintering temperature (400 and 600 °C), maintaining a constant pH = 3. Thereafter, two experimental conditions were selected to assess changes in the properties of CePO 4 nanopowders with pH (1, 5, 9 and 11). The crystal structure and morphology of the nanostructures were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM), respectively. Diffuse reflectance properties of CePO 4 with different microstructures were studied. The results demonstrated that by using the microwave-assisted hydrothermal method, the shape, size and structural phase of CePO 4 can be modulated by using relatively low synthesis temperatures and short reaction times, and depending on pH, a sintering process is not needed to obtain either a desired phase or size. Under the selected experimental conditions, the materials underwent an evolution from nanorods to semispherical nanoparticles, accompanied by a phase transition from hexagonal to monoclinic

  6. H2O2 rejuvenation-mediated synthesis of stable mixed-morphology Ag3PO4 photocatalysts

    Directory of Open Access Journals (Sweden)

    Henry Agbe

    2018-04-01

    Full Text Available Ag3PO4 photocatalyst has attracted interest of the scientific community in recent times due to its reported high efficiency for water oxidation and dye degradation. However, Ag3PO4 photo-corrodes if electron accepter such as AgNO3 is not used as scavenger. Synthesis of efficient Ag3PO4 followed by a simple protocol for regeneration of the photocatalyst is therefore a prerequisite for practical application. Herein, we present a facile method for the synthesis of a highly efficient Ag3PO4, whose photocatalytic efficiency was demonstrated using 3 different organic dyes: Methylene Blue (MB, Methyl orange (MO and Rhodamine B (RhB organic dyes for degradation tests. Approximately, 19 % of Ag3PO4 is converted to Ag0 after 4.30 hours of continuous UV-Vis irradiation in presence of MB organic dye. We have shown that the Ag/Ag3PO4 composite can be rejuvenated by a simple chemical oxidation step after several cycles of photocatalysis tests. At an optimal pH of 6.5, a mixture of cubic, rhombic dodecahedron, nanosphere and nanocrystals morphologies of the photocatalyst was formed. H2O2 served as the chemical oxidant to re-insert the surface metallic Ag into the Ag3PO4 photocatalyst but also as the agent that can control morphology of the regenerated as-prepared photocatalyst without the need for any other morphology controlling Agent (MCA. Surprisingly, the as- regenerated Ag3PO4 was found to have higher photocatalytic reactivity than the freshly made material and superior at least 17 times in comparison with the conventional Degussa TiO2, and some of TiO2 composites tested in this work. Keywords: Materials chemistry, Materials science, Engineering

  7. High 210Po atmospheric deposition flux in the subtropical coastal area of Japan

    International Nuclear Information System (INIS)

    Tateda, Yutaka; Iwao, Kenji

    2008-01-01

    Bulk atmospheric deposition fluxes of 210 Po and 210 Pb were measured at three coastal regions of Japan, the Pacific Ocean coastal area of the Japanese mainland (Odawa Bay), the Chinese continental side of Japanese coastal area (Tsuyazaki), and an isolated island near Okinawa (Akajima). Wet and dry fallout collectors were continuously deployed from September 1997 through August 1998 for periods of 3 to 31 days depending on the frequency of precipitation events. Annual 210 Pb deposition fluxes at Odawa Bay (35 o N 139 o E), Tsuyazaki (33 o N 130 o E) and Akajima (26 o N 127 o E) were 73.3 ± 8.0, 197 ± 35 and 78.5 ± 8.0 Bq m -2 y -1 , respectively. Higher 210 Pb deposition was observed at the Chinese continental side of Japanese coast than at the Pacific Ocean coastal site. The high 210 Pb atmospheric flux at the Chinese continental side coast was thought to be attributable to 222 Rn-rich air-mass transport from the Chinese continent during the winter monsoon. In contrast, the annual 210 Po deposition fluxes at the three study sites were 13.0 ± 2.3 (Odawa Bay), 21.9 ± 4.4 (Tsuyazaki) and 58.4 ± 7.7 (Akajima) Bq m -2 y -1 , respectively, indicating unusual high 210 Po deposition at Akajima during winter. Anomalous unsupported 210 Po input was observed during summer 1997, suggesting unknown source of 210 Po at this area

  8. Crystal structure, thermally stability and photoluminescence properties of novel Sr10(PO4)6O:Eu2+ phosphors

    International Nuclear Information System (INIS)

    Guo, Qingfeng; Liao, Libing; Mei, Lefu; Liu, Haikun

    2015-01-01

    A series of novel luminescent phosphors Sr 10 (PO 4 ) 6 O:Eu 2+ with apatite structure were synthesized via a high temperature solid-state reaction. The phase structure, photoluminescence (PL) properties, the PL thermal stability, as well as the fluorescence decay curves of the samples were investigated to characterize the resulting samples, and the selected Sr 9.97 (PO 4 ) 6 O:0.03Eu 2+ phosphor exhibits strong thermal quenching resistance, retaining the luminance of 88.73% at 150 °C. The quenching concentration of Eu 2+ in Sr 10 (PO 4 ) 6 O was about 0.03 attributing to the dipole–quadrupole interaction. The Sr 10 (PO 4 ) 6 O:Eu 2+ phosphor exhibited a broad-band blue emission at 439 nm upon excitation at 346 nm. The results indicate that Sr 10 (PO 4 ) 6 O:Eu 2+ phosphors have potential applications as near UV-convertible phosphors for white-light UV LEDs. - Graphical abstract: Sr 10 (PO 4 ) 6 O:Eu 2+ phosphors have potential applications as near UV-convertible phosphors for white-light UV LEDs. - Highlights: • Sr 9.97 (PO 4 ) 6 O:0.03Eu 2+ phosphor exhibits strong thermal quenching resistance. • Two different Eu 2+ emission centers exists in Sr 10 (PO 4 ) 6 O. • The activation energy was also estimated for the Eu 2+ luminescence center

  9. PoPSat: The Polar Precipitation Satellite Mission

    Science.gov (United States)

    Binder, Matthias J.; Agten, Dries; Arago-Higueras, Nadia; Borderies, Mary; Diaz-Schümmer, Carlos; Jamali, Maryam; Jimenez-Lluva, David; Kiefer, Joshua; Larsson, Anna; Lopez-Gilabert, Lola; Mione, Michele; Mould, Toby JD; Pavesi, Sara; Roth, Georg; Tomicic, Maja

    2017-04-01

    The terrestrial water cycle is one of many unique regulatory systems on planet Earth. It is directly responsible for sustaining biological life on land and human populations by ensuring sustained crop yields. However, this delicate balanced system continues to be influenced significantly by a changing climate, which has had drastic impacts particularly on the polar regions. Precipitation is a key process in the weather and climate system, due to its storage, transport and release of latent heat in the atmosphere. It has been extensively investigated in low latitudes, in which detailed models have been established for weather prediction. However, a gap has been left in higher latitudes above 65°, which show the strongest response to climate changes and where increasing precipitations have been foreseen in the future. In order to establish a global perspective of atmospheric processes, space observation of high-latitude areas is crucial to produce globally consistent data. The increasing demand for those data has driven a critical need to devise a mission which fills the gaps in current climate models. The authors propose the Polar Precipitation Satellite (PoPSat), an innovative satellite mission to provide enhanced observation of light and medium precipitation, focusing on snowfall and light rain in high latitudes. PoPSat is the first mission aimed to provide high resolution 3D structural information about snow and light precipitation systems and cloud structure in the covered areas. The satellite is equipped with a dual band (Ka and W band) phased-array radar. These antennas provide a horizontal resolution of 2 km and 4 km respectively which will exceed all other observations made to date at high-latitudes, while providing the additional capability to monitor snowfall. The data gathered will be compatible and complementary with measurements made during previous missions. PoPSat has been designed to fly on a sun-synchronous, dawn-dusk orbit at 460 km. This orbit

  10. Reproductive performance of peranakan ongole (PO) bull at different altitudes areas in Lampung province

    Science.gov (United States)

    Suretno, N. D.; Supriyatna, I.; Purwanto, B.; Priyanto, R.

    2018-01-01

    Peranakan Ongole (PO) cattle are famous for their bulls and known for their toughness, rapid growth and natural tolerance to tropical heat and disease resistance. This study was conducted to determine the reproductive performance of PO bull in some altitude in Lampung Province. A total of PO bulls used were 48 heads, with age three to four years. The variables observed were volume, consistency, pH, semen colour, concentration, mass movement, motility, percentage of living spermatozoa and abnormality. Data were collected during the rainy season and dry season, calculated with the average and standard deviation and then analyzed descriptively. Based on the macroscopic examination, Peranakan Ongole bull living in low temperature place had a normal semen volume, the consistency mostly watery to moderate, fresh semen pH is in the normal range and the color of semen are all normal both in the rainy and dry seasons. The results of microscopic examination showed that PO cattle had a good reproduction conditions at all three

  11. Room temperature H{sub 2}S gas sensing characteristics of platinum (Pt) coated porous alumina (PoAl) thick films

    Energy Technology Data Exchange (ETDEWEB)

    More, P.S., E-mail: p_smore@yahoo.co.in [Department of Physics, Institute of Science, Mumbai 400 032 (India); Raut, R.W. [Department of Botany, Institute of Science, Mumbai 400 032 (India); Ghuge, C.S. [Department of Physics, Institute of Science, Mumbai 400 032 (India)

    2014-02-14

    The study reports H{sub 2}S gas sensing characteristics of platinum (Pt) coated porous alumina (PoAl) films. The porous alumina (PoAl) thick layers were formed in the dark on aluminum substrates using an electrochemical anodization method. Thin semitransparent platinum (Pt) films were deposited on PoAl samples using chemical bath deposition (CBD) method. The films were characterized using energy dispersive X-ray analysis (EDAX) and scanning electron microscopy (SEM). The thicknesses of coated and bare films were measured using ellipsometry. The sensing properties such as sensitivity factor (S.F.), response time, recovery time and repeatability were measured using a static gas sensing system for H{sub 2}S gas. The EDAX studies confirmed the purity of Pt–PoAl film and indicated the formation of pure platinum (Pt) phase. The ellipsometry studies revealed the thickness of PoAl layer of about 15–17 μm on aluminum substrates. The SEM studies demonstrated uniform distribution of spherical pores with a size between 0.250 and 0.500 μm for PoAl film and nearly spherical platinum particles with average particle size ∼100 nm for Pt–PoAl film. The gas-sensing properties of these samples were studied in a home-built static gas characterization system. The H{sub 2}S gas sensing properties of Pt–PoAl at 1000 ppm of H{sub 2}S gave maximum sensitivity factor (S.F.) = 1200. The response time and recovery time were found to be 2–3 min and ∼1 min respectively. Further, the measurement of H{sub 2}S gas sensing properties clearly indicated the repeatability of gas sensing response of Pt–PoAl film. The present study indicated the significant potential of Pt coated PoAl films for H{sub 2}S gas sensing applications in diverse areas. - Highlights: • Electrochemical anodization, cheap and effective method for fabrication of PoAl. • Chemical bath deposition, a simple and effective method for deposition of Pt on PoAl. • A nano-composite film sensor with high sensitivity

  12. Preparation of V-Doped LiFePO4/C as the Optimized Cathode Material for Lithium Ion Batteries.

    Science.gov (United States)

    Sun, Pingping; Zhang, Haiyang; Shen, Kai; Fan, Qi; Xu, Qingyu

    2015-04-01

    LiFe1-x,Vx,PO4/C composites were synthesized by solid state reaction. The effect of carbon coating and V doping on the performance of LiFePO4 has been systematically investigated by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), charge/discharge and cyclic voltammetry (CV) measurement. The results show that carbon coating and proper amount of V incorporation do not significantly change the host crystal structure of LiFePO4, while the electrochemical performance of LiFePO4 can be significantly improved. Particularly, the LiFe0.96V0.04PO4/C exhibits the best performance with a specific discharge capacity of 105.5 mA h/g at 5.0 C, 90.3 mA h/g at 10 C and 66.7 mA h/g at 30 C with stable cycle performance, which is significantly improved compared with the pure LiFePO4/C. The cyclic voltammograms result reveals that V doping could decrease the resistance of LiFePO4/C composite electrode drastically and improve its reversibility.

  13. Correlation of 210Po and 210Pb enrichments in the sea-surface microlayer with neuston biomass

    International Nuclear Information System (INIS)

    Heyroud, M.; Cherry, R.D.

    1983-01-01

    Samples of surface microlayer, bulk seawater from 20 cm depth and neustonic organisms inhabiting the top 5 cm of the sea, were collected at regular intervals over a period of 17 months at a site 3 km off Monaco and analysed for naturally occurring radionuclides 210 Po and 210 Pb. Enrichment of 210 Po in the microlayer compared with bulk seawater was observed, and found to be correlated significantly with the neuston biomass per unit volume. Enrichment of 210 Pb in the microlayer was also observed, but only under higher neuston biomass conditions. The 210 Po: 210 Pb ratio was always higher in the microlayer than in bulk seawater. Additional information was obtained from 210 Po measurements made on the bulk seawater in which the neuston had been collected and in which it had stood for periods of 2 to 4 h. These showed the neuston lost 210 Po to the water at a rate of about 1 pCi g - 1 dry biomass h - 1 . A significant flux of 210 Po from bulk seawater to the surface microlayer, and thence possibly to the atmosphere, is estimated. This flux will vary seasonally with the planktonic biomass. Under high biomass conditions a similar flux for 210 Pb may also be significant. (author)

  14. Surface Modification of the LiFePO4 Cathode for the Aqueous Rechargeable Lithium Ion Battery.

    Science.gov (United States)

    Tron, Artur; Jo, Yong Nam; Oh, Si Hyoung; Park, Yeong Don; Mun, Junyoung

    2017-04-12

    The LiFePO 4 surface is coated with AlF 3 via a simple chemical precipitation for aqueous rechargeable lithium ion batteries (ARLBs). During electrochemical cycling, the unfavorable side reactions between LiFePO 4 and the aqueous electrolyte (1 M Li 2 SO 4 in water) leave a highly resistant passivation film, which causes a deterioration in the electrochemical performance. The coated LiFePO 4 by 1 wt % AlF 3 has a high discharge capacity of 132 mAh g -1 and a highly improved cycle life, which shows 93% capacity retention even after 100 cycles, whereas the pristine LiFePO 4 has a specific capacity of 123 mAh g -1 and a poor capacity retention of 82%. The surface analysis results, which include X-ray photoelectron spectroscopy and transmission electron microscopy results, show that the AlF 3 coating material is highly effective for reducing the detrimental surface passivation by relieving the electrochemical side reactions of the fragile aqueous electrolyte. The AlF 3 coating material has good compatibility with the LiFePO 4 cathode material, which mitigates the surface diffusion obstacles, reduces the charge-transfer resistances and improves the electrochemical performance and surface stability of the LiFePO 4 material in aqueous electrolyte solutions.

  15. 210Po activity concentrations in mussels at Aegean Turkish Coast

    International Nuclear Information System (INIS)

    Sekkin, F.; Tanbay, A.; Vener, V.

    2000-01-01

    In Turkey mussels (Mytilus galloprovincialis) are consumed in relatively large quantities. Therefore, analyses of mussel samples from different sampling sites in Aegean Sea were performed in order to evaluate the ingestion of 210 Po and 210 Pb by the Turkey population. Polonium analyses were performed with a complete dissolution of the sample in mineral acids. Polonium isotopes were plated onto a copper discs in 0.5 M HCl solution in the presence of ascorbic acid using a technique modified from Flynn (1968). The alpha activity measurements of polonium isotopes plated on copper discs were performed with ZnS(Ag) detector. The highest concentrations was found in Karaburun mussels as 254 Bq.kg -1 and the lowest one was at Inciralti as 18 Bq.kg -1 . Based on these 210 Po activity concentrations, annual dose equivalent rates delivered to biological tissues in mussels would vary widely, from 136 to 10 mSv.y -1 . It is concluded that in mussels living in the Aegean Sea a wide range of internal radiation dose exists and it is essentially sustained by 210 Po food-chain transfer. (author)

  16. Partnerships: The Key to Sustainability and Reach for E/PO

    Science.gov (United States)

    Eisenhamer, Bonnie; McCallister, D.; Ryer, H.

    2013-06-01

    The Space Telescope Science Institute (STScI) is the home institution for the E/PO activities of the Hubble and future James Webb space telescopes. Over time, STScI’s Office of Public Outreach has established the infrastructure needed for an E/PO program that reaches various audiences at the local, regional, and national levels. Partnerships are a critical element of this infrastructure, and sustainability of our E/PO program is ensured through our ongoing partnerships with organizations and institutions with staying power and reach. We have learned from past efforts that strategic partnerships can foster innovation, support diversity initiatives, and increase impact in a cost-effective way while providing target audiences with greater access to NASA SMD science and resources. Partnerships are utilized to field-test educational products and programs, disseminate materials and initiatives, and support professional development activities. Partners are selected based upon specific criteria such as potential for reach, the percentage of underrepresented educators and students served, complementary program goals, and willingness to collect and share evaluation data and results with us. This poster will highlight examples and benefits of strategic partnerships over time.

  17. PO2 measurements in the rat intestinal microcirculation

    NARCIS (Netherlands)

    Sinaasappel, M.; Donkersloot, C.; van Bommel, J.; Ince, C.

    1999-01-01

    Microvascular partial oxygen pressure (PO2) data measured with the quenched phosphorescence of palladium-porphyrin (Pd-porphyrin) with the use of optical fibers have provided new insight into the behavior of the microvascular oxygenation in models of shock. However, the actual microcirculatory

  18. Po kanalu TBTs pokazhut film o "Vaffen-SS"

    Index Scriptorium Estoniae

    2006-01-01

    Vene filmistuudio Treti Rim on tootnud lätivastase ajaloolise dokumentaali-propagandafilmi Teisest Maailmasõjast "Natslus Balti moodi" ("Natsizm po pribaltiski"). Filmi näitab täna Vene telekanal TVT, andes siiski võimaluse eetris esineda Läti Venemaa suursaadikule Andris Teikmanisele

  19. Oxygen delivery to the fish eye: root effect as crucial factor for elevated retinal PO2.

    Science.gov (United States)

    Waser, W; Heisler, N

    2005-11-01

    Although the retina has one of the highest metabolic rates among tissues, certain teleost fishes lack any vascular supply to this organ which, in combination with the overall thickness of the organ, results in extremely long diffusion distances. As the only way to compensate for these obstacles, oxygen partial pressure (PO2) in the eyes of such fish is elevated far above atmospheric values. Although not supported by any direct evidence, the enhancement of PO2 is considered to be related to the Root effect, the release upon acidification of Hb-bound O2 into physical dissolution, possibly supported by counter-current multiplication similar to the loop of Henle. The present study evaluates the magnitude of intraocular PO2 enhancement under tightly controlled physiological conditions, to directly confirm the involvement of the Root effect on intraocular PO2 in the retina of rainbow trout Oncorhynchus mykiss. Intraocular PO2 was determined with special polarographic microelectrodes inserted into the eye. PO2 profiles established in vivo by driving electrodes through the entire retina yielded average PO2 values between 10 mmHg (1.3 kPa) at the inner retinal surface and 382 mmHg (50.9 kPa) close to the outer retinal limit (Bruch's membrane). According to estimates on the basis of the diffusion distances determined from sections of the retina (approximately 436 microm at the site of PO2 measurement) and literature data on specific oxygen consumption, the in vivo determined values would be sufficient to cover the oxygen demand of the retina with some safety margin. For a clear and direct in-tissue-test as to the involvement of the Root effect, an isolated in vitro eye preparation was established in order to avoid the problem of indirect blood supply to the eye from the dorsal aorta only via the pseudobranch, a hemibranch thought to modulate blood composition before entry of the eye. Any humoral effects (e.g. catecholamines) were eliminated by perfusing isolated eyes

  20. Hierarchical LiFePO4 with a controllable growth of the (010) facet for lithium-ion batteries.

    Science.gov (United States)