Sample records for 217at 213po 209pb

  1. The continuum shell-model neutron states of 209Pb

    Indian Academy of Sciences (India)

    Ramendra Nath Majumdar


    The neutron strength distributions of the three high-spin 117/2, 2ℎ11/2 and 113/2 states of 209Pb have been obtained within the formalism of the core-polarisation effect where the effect of interaction of the neutron shell-model states of 209Pb with the collective vibrational states (originating also from the giant resonances) have been taken into consideration. The theoretical results have been discussed in the light of works on 117/2, 2ℎ11/2 and 113/2 neutron orbitals of 209Pb. The shell-model energies of the neutron states have been obtained by Skyrme–Hartree–Fock method.

  2. Measurement of 208Pb(n ,γ )209Pb Maxwellian averaged neutron capture cross section (United States)

    Weissman, L.; Tessler, M.; Arenshtam, A.; Eliyahu, I.; Halfon, S.; Guerrero, C.; Kaizer, B.; Kijel, D.; Kreisel, A.; Palchan, T.; Paul, M.; Perry, A.; Schimel, G.; Silverman, I.; Shor, A.; Tamim, N.; Vaintraub, S.


    The doubly magic 208Pb nucleus is a bottleneck at the termination of the s -process path due to its very low neutron capture cross section. This cross section is also important for the decomposition of s , r processes and U/Th radiogenic decay contributions to the Pb-Bi solar abundances. The 208Pb(n ,γ )209Pb cross section was measured at the Soreq Applied Research Accelerator Facility Phase I using an intense quasi-Maxwellian neutron source produced by irradiation of the liquid-lithium target with a 1.5-mA continuous-wave proton beam at 1.94 MeV. The cross section was measured by counting the β activity from the irradiated lead target. The measurement allowed us to evaluate the Maxwellian averaged cross section (MACS) at 30 keV obtaining a value of 0.33(2) mb. This has been compared with the earlier activation and time-of-flight measurements found in the literature. The MACS cross-sectional value of the 63Cu(n ,γ )64Cu reaction was determined in the same experiment and is compared to a recent published value.

  3. Contribution to construction and setup of a detection system for the focal plan of the BBS spectrometer. Application to study of the neutron emission decay of the resonant states populated by the reaction ({sup 4}He,{sup 3}He) at 42 MeV/u in nuclei {sup 208}Pb and {sup 209}Pb; Contribution a la construction et a la mise au point d'un systeme de detection pour le plan focal du spectrometre BBS. Application a l'etude de la decroissance par emission de neutrons d'etats resonants peuples par la reaction ({sup 4}He,{sup 3}He) a 42 MeV/u dans les noyaux {sup 208}Pb et {sup 209}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Plankl-Chabib, Elke [Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France)


    In order to realizean experimental program dedicated to nuclear structure studies we have conceived and constructed at IPN Orsay a detection system for the focal plane of the magnetic spectrometer BBS, installed at the cryogenic cyclotron AGOR of the laboratory KVI (The Netherlands). Two detection units, consisting each of two localization plans of the Cathode Strip Chamber (CSC) type, measure the position and angle of particle trajectory. This information is used for the determination of the reaction parameters at the target by a backtracking procedure. The identification of the reaction products is done by the measurement of their time-of-flight and energy loss. For light ions this task is assumed by plastic scintillators, and for heavy ions by a parallel plan detector (PPAC) and an ionization chamber. This detection system is well adapted to the requirements given by the detection of a large range of ions (protons to {sup 36}Ar at energies of several tenths of MeV/nucleon) as well as the big acceptance, the small dispersion and the aberration of the BBS. The results of the test show the good performances of the detection system. In a first experiment the focal plane detection system was coupled to the neutron multidetector EVEN in order to study the decay of resonant high spin states at high excitation energies by the ({sup 4}He, {sup 3}He) reaction on {sup 207}Pb and {sup 208}Pb targets. The transfer spectra, inclusive and in coincidence, of the nuclei {sup 208}Pb and {sup 209}Pb show a striking resemblance except for an excitation energy shift which is due to the hole in the last neutron shell of {sup 207}Pb. The resonances at l 8 and l = 9 are clearly populated, in agreement with the predictions of the Bonaccorso-Brink model. A sizeable fraction of the decay of the l = 8 resonance is direct, but at excitation energies higher than 15 MeV (in {sup 208}Pb) the decay is mostly statistical.

  4. Possible cluster preformation in the 14C decay of 223Ra (United States)

    Hussonnois, M.; Le Du, J. F.; Brillard, L.; Ardisson, G.


    A recent experiment on the 14C fine structure has shown that the branching ratio to 209Pb ground state is quite different from the one predicted by the various models of cluster emission. Assuming that the 14C is preformed in the 223Ra nucleus, we have calculated the hindrance factor F14C of the three 14C branches to 209Pb states with a barrier penetrability approximated by a square-well Coulomb potential. The F14C=3.9 and 4.6 values found for the 14C transitions to the two excited states at 779 keV (Iπ=11/2+) and 1423 keV (Iπ=15/2-), respectively, reveal that the cluster formation amplitudes in both transitions are close to those of the 222Ra and 224Ra 14C decays. Such values could be the result of ||nlj> shell-model components common to both the wave functions of the octupole deformed 223Ra nucleus and of the two first excited states of 209Pb spherical nucleus. The high hindrance factor F14C=583 of the 14C branch to the 209Pb ground state (Iπ=9/2+) could reveal the absence of ||1g9/2> shell-model component in the 223Ra wave function.

  5. Comment on ``Interpretation of the fine structure in the 14C radioactive decay of 223' (United States)

    Hussonnois, M.; Le Du, J. F.; Brillard, L.; Ardisson, G.


    Priority of our interpretation of the fine structure in the 14C radioactive decay of 223Ra is asserted. It seems that the deformation parameter values, used in the framework of ARM to interpret properties of both 223Ra ground and excited states, partly allow for the qualitative interpretation of the experimental hindrance factors to the 209Pb states.

  6. Single and multi-photon events with missing energy in $e^+ e^-$ collisions at 161 GeV < $\\sqrt{s}$ < 172 GeV

    CERN Document Server

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alverson, G; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Banerjee, S; Banerjee, Sw; Banicz, K; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Button, A M; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chekanov, S V; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chéreau, X J; Chiefari, G; Chien, C Y; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Commichau, V; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; Degré, A; Deiters, K; Della Volpe, D; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Fenyi, B; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gau, S S; Gentile, S; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Van Hoek, W C; Hofer, H; Hong, S J; Hoorani, H; Hou, S R; Hu, G; Innocente, Vincenzo; Jenkes, K; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kamyshkov, Yu A; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, D H; Kim, J K; Kim, S C; Kim, Y G; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; McNally, D; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Mihul, A; Van Mil, A J W; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Morganti, S; Moulik, T; Mount, R; Müller, S; Muheim, F; Muijs, A J M; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nippe, A; Nisati, A; Nowak, H; Oh, Yu D; Opitz, H; Organtini, G; Ostonen, R; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Park, I H; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petersen, B; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Pinto, J C; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Prokofev, D; Prokofiev, D O; Rahal-Callot, G; Raja, N; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Ruschmeier, D; Rykaczewski, H; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Sarkar, S; Sassowsky, M; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schmitz, P; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Sopczak, André; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, A; Stone, H; Stoyanov, B; Strässner, A; Strauch, K; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonutti, M; Tonwar, S C; Tóth, J; Tully, C; Tuchscherer, H; Tung, K L; Uchida, Y; Ulbricht, J; Uwer, U; Valente, E; Van de Walle, R T; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wittgenstein, F; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F


    A search for single and multi-photon events with missing energy is performed using data collected at centre-of-mass energies between 161 GeV and 172 GeV for a total of 20.9 pb$^{-1}$ of integrated luminosity. The results obtained are used to derive the value for the $\

  7. Nuclear levels and structure from the decays of 213Bi and 209Tl (United States)

    Ardisson, G.; Barci, V.; El Samad, O.


    Direct γ and γ-γ coincidence spectra of pure 209Tl and 213Bi sources obtained by radiochemical continuous separation were measured with coaxial and planar HPGe detectors. In 209Tl the half-life was measured, the β-decay energies and intensities of 11 γ transitions were reported, and a new decay scheme was proposed. In 213Bi β decay 22 transitions were observed, of which 18 were assigned to a new 213Po level scheme accounting for 9 excited states.

  8. Disentangling the transfer and breakup contributions from the inclusive ^{8}Li+ ^{208}Pb reaction

    CERN Document Server

    Moro, A M; García-Martínez, H; Aguilera, E F; Martínez-Quiroz, E; Gómez-Camacho, J


    An analysis of the elastic and one-neutron removal channel for the reaction (^{8})Li+(^{208})Pb reaction at energies around the Coulomb barrier is presented. For the elastic scattering, an optical model analysis of the experimental data is performed. The observed (^{7})Li is interpreted as the superposition of the one-neutron transfer reaction, (^{208})Pb((^{8})Li,(^{7} )Li)(^{209})Pb, and the breakup reaction. The separate contribution of each one of these processes has been calculated within the DWBA formalism. The sum of both contributions explains adequately the experimental angular distribution of (^{7})Li.

  9. 209Tl half-life and gamma-ray measurements of radionuclides belonging to the (4 n + 1) decay chain (United States)

    Ardisson, G.; Barci, V.; El Samad, O.


    Gamma-ray spectra of radiochemically separated 221Fr, 213Bi and 209Tl sources were measured using coaxial and planar HPGe detectors. The energies and emission probabilities of eight new gamma-ray transitions were observed in the decay of 209Tl; a half-life of (2.161±0.007) min was measured. Twenty-two gamma-rays have been attributed to the β-decay of 213Bi, of which 17 are new with respect to previous studies. The 213Po level scheme was determined using γ-γ coincidence measurements: eight excited states are proposed of which six are new. Preliminary measurements of the α-decay of 221Fr revealed the existence of 18 gamma-ray transitions of which eight are reported for the first time.

  10. Neutron halos in the excited states for N=127 isotones

    Institute of Scientific and Technical Information of China (English)

    SUN Qin; GUO Jian-You


    Properties of the ground states and the excited states of N=127 isotones are investigated by using the nonlinear relativistic mean field theory with the interactions PK1. By analyzing the rms of proton and neutron, the single particle energies of valence nucleon and the density distributions of neutron, proton and the last neutron, it can be found that there exists a neutron halo in the excited states of 3d5/2, 4s1/2 and 3d3/2 in 209Pb. It is also predicted that there exists a neutron halo in the excited states of 3d5/2, 4s1/2 and 3d3/2 in 207Hg, 208Tl, 210Bi and 211Po.

  11. Coupled-Channel Models of Direct-Semidirect Capture via Giant-Dipole Resonances

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, I J [Lawrence Livermore National Laboratory (LLNL); Escher, Jutta E [ORNL; Arbanas, Goran [ORNL


    Semidirect capture, a two-step process that excites a giant-dipole resonance followed by its radiative de-excitation, is a dominant process near giant-dipole resonances, that is, for incoming neutron energies within 5 20 MeV. At lower energies such processes may affect neutron capture rates that are relevant to astrophysical nucleosynthesis models. We implement a semidirect capture model in the coupled-channel reaction code Fresco and validate it by comparing the cross section for direct-semidirect capture 208Pb(n,g)209Pb to experimental data. We also investigate the effect of low-energy electric dipole strength in the pygmy resonance. We use a conventional single-particle direct-semidirect capture code Cupido for comparison. Furthermore, we present and discuss our results for direct-semidirect capture reaction 130Sn(n,g)131Sn, the cross section of which is known to have a significant effect on nucleosynthesis models.

  12. Precise Study of Fine Structure in $^{14}$C Emission from $^{223}$Ra

    CERN Multimedia


    We request 10 shifts in two sessions of beam time at ISOLDE for the production of a $^{223}$Ra source. This source will be used with the superconducting spectrometer SOLENO at Orsay for a precise measurement (good statistics and energy resolution) of the fine stucture in the energy spectrum of $^{14}$C nuclei emitted by $^{223}$Ra, discovered at Orsay in July 1989. The measurement will be devoted to carry out the hindrance factors of the transitions to 15$\\!^-\\!$/2$\\,$ (1.423 MeV) and 5$\\!^+\\!$/2$\\,$ (1.567 MeV) excited states of $^{209}$Pb, which present a particular interest for obtaining spectroscopic information and testing nuclear models.

  13. Evaluation of decay data of 213Bi

    Institute of Scientific and Technical Information of China (English)

    HUANG Xiaolong; WANG Baosong


    213Bi disintegrates (97.91±0.03) % by β- emission to the levels in 213po, and (2.09±0.03) % through α decay to 209Tl. The evaluation of the complete decay scheme and data of 213Bi including the recent new measurements are presented in this report. The Limitation of Relative Statistical Weight Method (LWM) was applied to average numbers throughout the evaluation. The uncertainty assigned to the average value was always greater than or equal to the smallest uncertainty of the values used to calculate the average. The half-life is determined to be 45.59±0.06 minutes. All known measured gamma-ray relative emission probabilities have been examined. And the gamma-ray emission probability of the reference γ line of 440.44keV is recommended to be (26.1±0.3) %. The calculated internal conversion coefficients and their uncertainties have been used to obtain the complete decay intensity balance. The other decay characteristics are calculated using the ENSDF analysis program. Finally the new 213Bi decay scheme was re-built.

  14. /sup 5/He radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Poenaru, D.N.; Ivascu, M. (Institute for Physics and Nuclear Engineering, Bucharest (Romania))


    The disintegration of a metastable nuclear state by emission of a light particle can be considered to be a very asymmetric fission process. An approximation of the potential barrier in the overlapping region of the two fragments leads to an analytic relationship for the life-time, allowing us to handle a large number of cases to search for new kinds of radioactivities. In this way, it is predicted that some nuclei with Z=83-92, N=127-137 and 97-105, 145-157 are able to decay spontaneously by emission of /sup 5/He particles. A tentative optimistic estimation leads to the result that only 15 radionuclides should have partial life-times in the range 10/sup 14/-10/sup 38/ years; all others, except some superheavies, are longer lived. The best candidate is /sup 213/Po for which the daughter is a double magic nucleus. Smaller life-times, with a better chance to be experimentally confirmed have some ..beta..-delayed /sup 5/He emitters, as for example /sup 155/Yb, /sup 175/Pt, /sup 209 -217/Ra, /sup 9 -11/Be, /sup 13 -14/B, /sup 13 -17/C and /sup 19 -21/O.

  15. Fine structure in the cluster decay of radium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Santhosh, K P [School of Pure and Applied Physics, Kannur University, Payyanur Campus, Payyanur 670 327 (India)], E-mail:


    Half-life times for {sup 14}C cluster emission from various radium isotopes are computed taking interacting potential as the sum of Coulomb and proximity potentials. The half-life time values are compared with experimental data and with the values reported by Poenaru et al using the analytical super-asymmetric fission model (ASAFM). The lowest half-life time for {sup 222}Ra stresses the role of the doubly magic {sup 208}Pb daughter in the exotic decay process. It is found that neutron excess in the parent nucleus slows down the exotic decay process. The high hindrance factor (HF) of the {sup 14}C branch to the ground state (9/2{sup +}) and the low HF to the first excited state (11/2{sup +}) of the {sup 209}Pb daughter are in good agreement with the experimental result. The fine structure from {sup 223}Ra gives direct evidence of the presence of a spherical component in the deformed parent nucleus.

  16. Enhanced soil washing process for the remediation of PBDEs/Pb/Cd-contaminated electronic waste site with carboxymethyl chitosan in a sunflower oil-water solvent system and microbial augmentation. (United States)

    Ye, Mao; Sun, Mingming; Wan, Jinzhong; Fang, Guodong; Li, Huixin; Hu, Feng; Jiang, Xin; Kengara, Fredrick Orori


    An innovative ex situ soil washing technology was developed to remediate polybrominated diphenyl ethers (PBDEs) and heavy metals in an electronic waste site. Elevated temperature (50 °C) in combination with ultrasonication (40 kHz, 20 min) at 5.0 mL L(-1) sunflower oil and 2.5 g L(-1) carboxymethyl chitosan were found to be effective in extracting mixed pollutants from soil. After two successive washing cycles, the removal efficiency rates for total PBDEs, BDE28, BDE47, BDE209, Pb, and Cd were approximately 94.1, 93.4, 94.3, 99.1, 89.3, and 92.7 %, respectively. Treating the second washed soil with PBDE-degrading bacteria (Rhodococcus sp. strain RHA1) inoculation and nutrient addition for 3 months led to maximum biodegradation rates of 37.3, 52.6, 23.9, and 1.3 % of the remaining total PBDEs, BDE28, BDE47, BDE209, respectively. After the combined treatment, the microbiological functions of washed soil was partially restored, as indicated by a significant increase in the counts, biomass C, N, and functioning diversity of soil microorganisms (p remediated soil was limited. Therefore, the proposed combined cleanup strategy is an environment-friendly technology that is important for risk assessment and management in mixed-contaminated sites.

  17. Effects of Nonlocality on Transfer Reactions

    CERN Document Server

    Titus, Luke J


    We solved the nonlocal scattering and bound state equations using the Perey-Buck type interaction, and compared to local equivalent calculations. Using the distorted wave Born approximation we construct the T-matrix for (p,d) transfer on 17O, 41Ca, 49Ca, 127Sn, 133Sn, and 209Pb at 20 and 50 MeV. Additionally we studied (p,d) reactions on 40Ca using the the nonlocal dispersive optical model. We have also included nonlocality consistently into the adiabatic distorted wave approximation and have investigated the effects of nonlocality on on (d,p) transfer reactions for deuterons impinged on 16O, 40Ca, 48Ca, 126Sn, 132Sn, 208Pb at 10, 20, and 50 MeV. We found that for bound states the Perry corrected wave functions resulting from the local equation agreed well with that from the nonlocal equation in the interior region, but discrepancies were found in the surface and peripheral regions. Overall, the Perey correction factor was adequate for scattering states, with the exception for a few partial waves. Nonlocality...

  18. Testing the Perey Effect

    CERN Document Server

    Titus, L J


    Background: The effects of non-local potentials have historically been approximately included by applying a correction factor to the solution of the corresponding equation for the local equivalent interaction. This is usually referred to as the Perey correction factor. Purpose: In this work we investigate the validity of the Perey correction factor for single-channel bound and scattering states, as well as in transfer (p,d) cross sections. Method: We solve the scattering and bound state equations for non-local interactions of the Perey-Buck type, through an iterative method. Using the distorted wave Born approximation, we construct the T-matrix for (p,d) on 17O, 41Ca, 49Ca, 127Sn, 133Sn, and 209Pb at 20 and 50 MeV. Results: We found that for bound states, the Perey corrected wave function resulting from the local equation agreed well with that from the non-local equation in the interior region, but discrepancies were found in the surface and peripheral regions. Overall, the Perey correction factor was adequat...

  19. Meson-Exchange Enhancement of First-Forbidden $\\beta$-Transitions in the Lead Region

    CERN Multimedia

    Delaure, B J P; Severijns, N


    Both on-line and off-line low temperature nuclear orientation is used to measure the $\\beta$-asymmetry parameter for the first-forbidden g.s. $\\rightarrow$~g.s. $\\beta$-transitions of $^{205}$Hg, $^{207,209}$Tl, $^{209}$Pb and $^{213}$Bi. From this, the ratio of the rank-zero and the rank-one strengths in these decays can be deduced, with the rank of a $\\beta$-transition being defined as the total angular momentum of the lepton system. Combining this result with the experimental ${ft}$-values yields for the first time a purely experimental determination of the rank-zero contribution in these $\\Delta$ J = 0 first-forbidden transitions. This provides an independent check of the large enhancement (of about 100% over the impulse approximation) of the rank-zero matrix element of $\\gamma_{5} $, caused by meson exchange currents (MEC), which was recently obtained from a comparison of calculated first-forbidden $\\beta$-decay rates with experimentally observed values for nuclei in the lead region (A = 205-212). Measur...

  20. Lead isotopes and trace metal ratios of aerosols as tracers of Pb pollution sources in Kanpur, India (United States)

    Sen, Indra; Bizimis, Michael; Tripathi, Sachchida; Paul, Debajyoti; Tyagi, Swati; Sengupta, Deep


    The anthropogenic flux of Pb in the Earth's surface is almost an order of magnitude higher than its corresponding natural flux [1]. Identifying the sources and pathways of anthropogenic Pb in environment is important because Pb toxicity is known to have adverse effects on human health. Pb pollution sources for America, Europe, and China are well documented. However, sources of atmospheric Pb are unknown in India, particularly after leaded gasoline was phased out in 2000. India has a developing economy with a rapidly emerging automobile and high temperature industry, and anthropogenic Pb emission is expected to rise in the next decade. In this study, we report on the Pb- isotope compositions and trace metal ratios of airborne particulates collected in Kanpur, an industrial city in northern India. The Pb concentration in the airborne particulate matter varies between 14-216 ng/m3, while the other heavy metals vary by factor of 10 or less, e.g. Cd=0.3-3 ng/m3, As=0.4-3.5 ng/m3, Zn=36-161 ng/m3, and Cu=3-22 ng/m3. The 206Pb/207Pb, 208Pb/206Pb, and 208Pb/207Pb vary between 1.112 - 1.129, 2.123-2.141, and 2.409-2.424 respectively, and are highly correlated with each other (R2>0.9). Pb isotopes and trace metal data reveals that coal combustion is the major source of anthropogenic Pb in the atmosphere, with limited contribution from mining and smelting processes. We further conclude that combination of Pb isotope ratios and V/Pb ratios are powerful tracers for Pb source apportionment studies, which is otherwise difficult to differentiate based only on Pb systematics [1] Sen and Peucker-Ehrenbrink (2012), Environ. Sci. Technol.(46), 8601-8609

  1. Dynamics of Marine Zooplankton: Social Behavior, Ecological Interactions, and Physically-Induced Variability (United States)


    daZa (1.12) dt W P +Ph dP -rP(1-P) dt - wj (1.13) E [wa P +Ph \\W /P+Phj The structured predator-prey model is similar in some ways to the one...B(P, Za)Z. - Q(P)ZI - djZ3 + V2Zj (2.16)at n azaa - rQ(P)Zj - daZa - V" [uZa - tVZa] (2.17)at a = rP I- - [B(P, Za)Z. + (rq - 1)Q(P)Zj] + KV2 P

  2. An ion guide for the production of a low energy ion beam of daughter products of {alpha}-emitters

    Energy Technology Data Exchange (ETDEWEB)

    Tordoff, B. [Nuclear Physics Group, Schuster Laboratory, Brunswick Street, University of Manchester, Manchester M13 9PL (United Kingdom)]. E-mail:; Eronen, T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, 40014 Jyvaeskylae (Finland); Elomaa, V.V. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, 40014 Jyvaeskylae (Finland); Gulick, S. [Ernest Rutherford Physics Building, McGill University, 3600 rue University, Montreal, QC, H3A 2T8 (Canada); Hager, U. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, 40014 Jyvaeskylae (Finland); Karvonen, P. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, 40014 Jyvaeskylae (Finland); Kessler, T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, 40014 Jyvaeskylae (Finland); Lee, J. [Ernest Rutherford Physics Building, McGill University, 3600 rue University, Montreal, QC, Canada H3A 2T8 (Canada); Moore, I. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, 40014 Jyvaeskylae (Finland); Popov, A. [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188350 (Russian Federation); Rahaman, S. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, 40014 Jyvaeskylae (Finland); Rinta-Antila, S. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, 40014 Jyvaeskylae (Finland); Sonoda, T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, 40014 Jyvaeskylae (Finland); Aystoe, J. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, 40014 Jyvaeskylae (Finland)


    A new ion guide has been modeled and tested for the production of a low energy ({approx}40 kV) ion beam of daughter products of alpha-emitting isotopes. The guide is designed to evacuate daughter recoils originating from the {alpha}-decay of a {sup 233}U source. The source is electroplated onto stainless steel strips and mounted along the inner walls of an ion guide chamber. A combination of electric fields and helium gas flow transport the ions through an exit hole for injection into a mass separator. Ion guide efficiencies for the extraction of {sup 229}Th{sup +} (0.06%), {sup 221}Fr{sup +} (6%) and {sup 217}At{sup +} (6%) beams have been measured. A detailed study of the electric field and gas flow influence on the ion guide efficiency is described for two differing electric field configurations.

  3. An Ion Guide for the Production of a Low Energy Ion Beam of Daughter Products of $\\alpha$-Emitters

    CERN Document Server

    Tordoff, B; Elomaa, V V; Gulick, S; Hager, U; Karvonen, P; Kessler, T; Lee, J; Moore, I; Popov, A; Rahaman, S; Rinta-Antila, S; Sonoda, T; Äystö, J


    A new ion guide has been modeled and tested for the production of a low energy ($\\approx$ 40 kV) ion beam of daughter products of alpha-emitting isotopes. The guide is designed to evacuate daughter recoils originating from the $\\alpha$-decay of a $^{233}$U source. The source is electroplated onto stainless steel strips and mounted along the inner walls of an ion guide chamber. A combination of electric fields and helium gas flow transport the ions through an exit hole for injection into a mass separator. Ion guide efficiencies for the extraction of $^{229}$Th$^{+}$ (0.06%), $^{221}$Fr$^{+}$ (6%), and $^{217}$At$^{+}$ (6%) beams have been measured. A detailed study of the electric field and gas flow influence on the ion guide efficiency is described for two differing electric field configurations.

  4. Analyses of antibacterial activity and cell compatibility of titanium coated with a Zr-C-N film.

    Directory of Open Access Journals (Sweden)

    Yin-Yu Chang

    Full Text Available OBJECTIVE: The purpose of this study was to verify the antibacterial performance and cell proliferation activity of zirconium (Zr-carbon (C-nitride (N coatings on commercially pure titanium (Ti with different C contents. MATERIALS AND METHODS: Reactive nitrogen gas (N(2 with and without acetylene (C(2H(2 was activated by Zr plasma in a cathodic-arc evaporation system to deposit either a zirconium nitride (ZrN or a Zr-C-N coating onto Ti plates. The bacterial activity of the coatings was evaluated against Staphylococcus aureus with the aid of SYTO9 nucleic acid staining and scanning electron microscopy (SEM. Cell compatibility, mRNA expression, and morphology related to human gingival fibroblasts (HGFs on the coated samples were also determined by using the MTT assay, reverse transcriptase-polymerase chain reaction, and SEM. RESULTS: The Zr-C-N coating with the highest C content (21.7 at% exhibited the lowest bacterial preservation (P<0.001. Biological responses including proliferation, gene expression, and attachment of HGF cells to ZrN and Zr-C-N coatings were comparable to those of the uncoated Ti plate. CONCLUSIONS: High-C-content Zr-C-N coatings not only provide short-term antibacterial activity against S. aureus but are also biocompatible with HGF cells.

  5. Nitrogen-Doped Hollow Carbon Nanospheres for High-Performance Li-Ion Batteries. (United States)

    Yang, Yufen; Jin, Song; Zhang, Zhen; Du, Zhenzhen; Liu, Huarong; Yang, Jia; Xu, Hangxun; Ji, Hengxing


    N-doped carbon materials is of particular attraction for anodes of lithium-ion batteries (LIBs) because of their high surface areas, superior electrical conductivity, and excellent mechanical strength, which can store energy by adsorption/desorption of Li(+) at the interfaces between the electrolyte and electrode. By directly carbonization of zeolitic imidazolate framework-8 nanospheres synthesized by an emulsion-based interfacial reaction, we obtained N-doped hollow carbon nanospheres with tunable shell thickness (20 nm to solid sphere) and different N dopant concentrations (3.9 to 21.7 at %). The optimized anode material possessed a shell thickness of 20 nm and contained 16.6 at % N dopants that were predominately pyridinic and pyrrolic. The anode delivered a specific capacity of 2053 mA h g(-1) at 100 mA g(-1) and 879 mA h g(-1) at 5 A g(-1) for 1000 cycles, implying a superior cycling stability. The improved electrochemical performance can be ascribed to (1) the Li(+) adsorption dominated energy storage mechanism prevents the volume change of the electrode materials, (2) the hollow nanostructure assembled by the nanometer-sized primary particles prevents the agglomeration of the nanoparticles and favors for Li(+) diffusion, (3) the optimized N dopant concentration and configuration facilitate the adsorption of Li(+); and (4) the graphitic carbon nanostructure ensures a good electrical conductivity.

  6. Keck and VLT Observations of Super-damped Lyman-alpha Absorbers at z=2=2.5: Constraints on Chemical Compositions and Physical Conditions

    CERN Document Server

    Kulkarni, Varsha P; Morrison, Sean; Peroux, Celine; Quiret, Samuel; York, Donald G


    We report Keck/ESI and VLT/UVES observations of three super-damped Lyman-alpha quasar absorbers with H I column densities log N(HI) >= 21.7 at redshifts z=2-2.5. All three absorbers show similar metallicities (-1.3 to -1.5 dex), and dust depletion of Fe, Ni, and Mn. Two of the absorbers show supersolar [S/Zn] and [Si/Zn]. We combine our results with those for other DLAs to examine trends between N(HI), metallicity, dust depletion. A larger fraction of the super-DLAs lie close to or above the line [X/H]=20.59-log N(HI) in the metallicity vs. N(HI) plot, compared to the less gas-rich DLAs, suggesting that super-DLAs are more likely to be rich in molecules. Unfortunately, our data for Q0230-0334 and Q0743+1421 do not cover H2 absorption lines. For Q1418+0718, some H2 lines are covered, but not detected. CO is not detected in any of our absorbers. For DLAs with log N(HI) 21.7 may have somewhat narrower velocity dispersions delta v_90 than the less gas-rich DLAs, and may arise in cooler and/or less turbulent gas.

  7. Assessing the Availability of Healthier Children's Meals at Leading Quick-Service and Full-Service Restaurants. (United States)

    Sliwa, Sarah; Anzman-Frasca, Stephanie; Lynskey, Vanessa; Washburn, Kyle; Economos, Christina


    To compare the calorie, fat, saturated fat, and sodium content of available children's meal combinations in leading restaurants with national recommendations. Cross-sectional. Children's menu offerings and corresponding nutrition information were collected (May, 2014) from Web sites of the top 10 quick-service (QSR) and top 10 full-service (FSR) restaurant chains that offered a children's menu and provided nutrition information. Total calories (kcal), percent calories from fat and saturated fat, and total sodium (mg) were calculated for children's meal combinations (QSR N = 1,363; FSR N = 6,654). Combinations with ≤ 600 kcal, ≤ 35% kcal from fat, ≤ 10% kcal from saturated fat, ≤ 770 mg sodium, and those that met all 4 of these criteria were identified. Frequencies by restaurant segment. The majority of QSR (72%) and FSR (63%) meal combinations had ≤ 600 kcal. Only 31.9% of combinations at QSRs and 21.7% at FSRs met all 4 criteria. In both segments the calorie target was most frequently met, and the sodium target the least. Children's meal combinations with ≤ 600 kcal are available at leading restaurant chains, but many meals fail to meet current national recommendations for fat, saturated fat, and sodium. Menu labeling legislation may address caloric content but implications for other nutrients remain unclear. Copyright © 2016 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

  8. Cross-sectional survey of treatment practices for urethritis at pharmacies, private clinics and government health facilities in coastal Kenya: many missed opportunities for HIV prevention. (United States)

    Mugo, Peter M; Duncan, Sarah; Mwaniki, Samuel W; Thiong'o, Alexander N; Gichuru, Evanson; Okuku, Haile Selassie; van der Elst, Elise M; Smith, Adrian D; Graham, Susan M; Sanders, Eduard J


    While bacterial sexually transmitted infections (STIs) are important cofactors for HIV transmission, STI control has received little attention in recent years. The aim of this study was to assess STI treatment and HIV testing referral practices among health providers in Kenya. In 2011 we assessed quality of case management for male urethritis at pharmacies, private clinics and government health facilities in coastal Kenya using simulated visits at pharmacies and interviews at pharmacies and health facilities. Quality was assessed using Ministry of Health guidelines. Twenty (77%) of 26 pharmacies, 20 (91%) of 22 private clinics and all four government facilities in the study area took part. The median (IQR) number of adult urethritis cases per week was 5 (2-10) at pharmacies, 3 (1-3) at private clinics and 5 (2-17) at government facilities. During simulated visits, 10% of pharmacies prescribed recommended antibiotics at recommended dosages and durations and, during interviews, 28% of pharmacies and 27% of health facilities prescribed recommended antibiotics at recommended dosages and durations. Most regimens were quinolone-based. HIV testing was recommended during 10% of simulated visits, 20% of pharmacy interviews and 25% of health facility interviews. In an area of high STI burden, most men with urethritis seek care at pharmacies and private clinics. Most providers do not comply with national guidelines and very few recommend HIV testing. In order to reduce the STI burden and mitigate HIV transmission, there is an urgent need for innovative dissemination of up-to-date guidelines and inclusion of all health providers in HIV/STI programmes.

  9. [Spectral analysis of polyphenol oxidase (PPO) and lipoxygenase (LOX) treated by pulsed electric field]. (United States)

    Luo, Wei; Zhang, Ruo-Bing; Chen, Jie; Wang, Li-Ming; Guan, Zhi-Cheng; Jia, Zhi-Dong


    Inactivation effect of pulsed electric field (PEF) on polyphenol oxidase (PPO) and lipoxygenase (LOX) was investigated using a laboratory PEF system with a coaxial treatment chamber. Circular dichroism (CD) and fluorescence analysis were used to study the conformation change of the protein. The experimental results show that PPO and LOX can be effectively inactivated by the PEF treatment. Inactivation effect of PPO and LOX increases with the increase in the applied electric strength and the treatment time. Activity of PPO and LOX can be reduced by 60.3% and 21.7% at 20 kV x cm(-1) after being treated for 320 micros respectively. The decrease of the negative peaks (208 and 215 nm in PPO spectra, 208 nm and 218 nm in LOX spectra) in CD spectra of PPO and LOX shows that PEF treatment caused a loss of alpha-helix and increase in beta-sheet content, indicating that conformation changes occur in the secondary structure of PPO and LOX enzyme. This effect was strengthened as the applied electric field increased: alpha-helical content of PPO and LOX was 56% and 29% after being treated at 8 kV x cm(-1), however, when the electric field was increased up to 20 kV x cm(-1), alpha-helical content of PPO and LOX decreased to 21% and 16% respectively. The decrease rate of alpha-helix and increase rate of beta-sheet in PPO are higher than LOX, indicating that the second conformation of PPO is less resistant to PEF treatment than LOX. The fluorescence intensity of LOX increases after PEF treatment. At the same time, increasing the applied pulsed electric field increases the fluorescence intensity emitted. Fluorescence measurements confirm that tertiary conformation changes occur in the local structure of LOX. However the possible mechanism of the conformation change induced by the PEF treatment is beyond the scope of the present investigation.

  10. Crystal Structures of a Piscine Betanodavirus: Mechanisms of Capsid Assembly and Viral Infection.

    Directory of Open Access Journals (Sweden)

    Nai-Chi Chen


    Full Text Available Betanodaviruses cause massive mortality in marine fish species with viral nervous necrosis. The structure of a T = 3 Grouper nervous necrosis virus-like particle (GNNV-LP is determined by the ab initio method with non-crystallographic symmetry averaging at 3.6 Å resolution. Each capsid protein (CP shows three major domains: (i the N-terminal arm, an inter-subunit extension at the inner surface; (ii the shell domain (S-domain, a jelly-roll structure; and (iii the protrusion domain (P-domain formed by three-fold trimeric protrusions. In addition, we have determined structures of the T = 1 subviral particles (SVPs of (i the delta-P-domain mutant (residues 35-217 at 3.1 Å resolution; and (ii the N-ARM deletion mutant (residues 35-338 at 7 Å resolution; and (iii the structure of the individual P-domain (residues 214-338 at 1.2 Å resolution. The P-domain reveals a novel DxD motif asymmetrically coordinating two Ca2+ ions, and seems to play a prominent role in the calcium-mediated trimerization of the GNNV CPs during the initial capsid assembly process. The flexible N-ARM (N-terminal arginine-rich motif appears to serve as a molecular switch for T = 1 or T = 3 assembly. Finally, we find that polyethylene glycol, which is incorporated into the P-domain during the crystallization process, enhances GNNV infection. The present structural studies together with the biological assays enhance our understanding of the role of the P-domain of GNNV in the capsid assembly and viral infection by this betanodavirus.

  11. Dynamical Cluster-decay Model (DCM) applied to 9Li+208Pb reaction (United States)

    Kaur, Arshdeep; Hemdeep; Kaushal, Pooja; Behera, Bivash R.; Gupta, Raj K.


    The decay mechanism of 217At* formed in 9Li+208Pb reaction is studied within the dynamical cluster-decay model (DCM) at various center-of-mass energies. The aim is to see the behavior of a light neutron-rich radioactive beam on a doubly-magic target nucleus for the (total) fusion cross section σfus and the individual decay channel cross sections. Experimentally, only the isotopic yield of heavy mass residues 211-214At * [equivalently, the light-particles (LPs) evaporation residue cross sections σxn for x = 3- 6 neutrons emission] are measured, with the fusion-fission (ff) component σff taken zero. For a fixed neck-length parameter ΔR, the only parameter in the DCM, we are able to fit σfus =∑x=16σxn almost exactly for 9Li on 208Pb at all E c . m .'s. However, the observed individual decay channels (3n-6n) are very poorly fitted, with unobserved channels (1n, 2n) and σff strongly over-estimated. Different ΔR values, meaning thereby different reaction time scales, are required to fit individually both the observed and unobserved evaporation residue channels (1n-6n) and σff, but then the compound nucleus (CN) contribution σCN is very small (< 1%), and the non-compound nucleus (nCN) decay cross section σnCN contributes the most towards total σfus (=σCN +σnCN). Thus, the 9Li induced reaction on doubly-magic 208Pb is more of a quasi-fission-like nCN decay, which is further analyzed in terms of the statistical CN formation probability PCN and CN survival probability Psurv. For the reaction under study, PCN < < 1 and Psurv → 1, in particular at above barrier energies.

  12. Analysis of epitopes on dengue virus envelope protein recognized by monoclonal antibodies and polyclonal human sera by a high throughput assay.

    Directory of Open Access Journals (Sweden)

    Hong-En Lin


    Full Text Available BACKGROUND: The envelope (E protein of dengue virus (DENV is the major target of neutralizing antibodies and vaccine development. While previous studies on domain III or domain I/II alone have reported several epitopes of monoclonal antibodies (mAbs against DENV E protein, the possibility of interdomain epitopes and the relationship between epitopes and neutralizing potency remain largely unexplored. METHODOLOGY/PRINCIPAL FINDINGS: We developed a dot blot assay by using 67 alanine mutants of predicted surface-exposed E residues as a systematic approach to identify epitopes recognized by mAbs and polyclonal sera, and confirmed our findings using a capture-ELISA assay. Of the 12 mouse mAbs tested, three recognized a novel epitope involving residues (Q211, D215, P217 at the central interface of domain II, and three recognized residues at both domain III and the lateral ridge of domain II, suggesting a more frequent presence of interdomain epitopes than previously appreciated. Compared with mAbs generated by traditional protocols, the potent neutralizing mAbs generated by a new protocol recognized multiple residues in A strand or residues in C strand/CC' loop of DENV2 and DENV1, and multiple residues in BC loop and residues in DE loop, EF loop/F strand or G strand of DENV1. The predominant epitopes of anti-E antibodies in polyclonal sera were found to include both fusion loop and non-fusion residues in the same or adjacent monomer. CONCLUSIONS/SIGNIFICANCE: Our analyses have implications for epitope-specific diagnostics and epitope-based dengue vaccines. This high throughput method has tremendous application for mapping both intra and interdomain epitopes recognized by human mAbs and polyclonal sera, which would further our understanding of humoral immune responses to DENV at the epitope level.

  13. Edge effects enhance selfing and seed harvesting efforts in the insect-pollinated Neotropical tree Copaifera langsdorffii (Fabaceae). (United States)

    Tarazi, R; Sebbenn, A M; Kageyama, P Y; Vencovsky, R


    Edge effects may affect the mating system of tropical tree species and reduce the genetic diversity and variance effective size of collected seeds at the boundaries of forest fragments because of a reduction in the density of reproductive trees, neighbour size and changes in the behaviour of pollinators. Here, edge effects on the genetic diversity, mating system and pollen pool of the insect-pollinated Neotropical tree Copaifera langsdorffii were investigated using eight microsatellite loci. Open-pollinated seeds were collected from 17 seed trees within continuous savannah woodland (SW) and were compared with seeds from 11 seed trees at the edge of the savannah remnant. Seeds collected from the SW had significantly higher heterozygosity levels (Ho=0.780; He=0.831) than seeds from the edge (Ho=0.702; He=0.800). The multilocus outcrossing rate was significantly higher in the SW (tm=0.859) than in the edge (tm=0.759). Pollen pool differentiation was significant, however, it did not differ between the SW (=0.105) and the edge (=0.135). The variance effective size within the progenies was significantly higher in the SW (Ne=2.65) than at the edge (Ne=2.30). The number of seed trees to retain the reference variance effective size of 500 was 189 at the SW and 217 at the edge. Therefore, it is preferable that seed harvesting for conservation and environmental restoration strategies be conducted in the SW, where genetic diversity and variance effective size within progenies are higher.

  14. Substrate impact on the low-temperature growth of GaN thin films by plasma-assisted atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kizir, Seda; Haider, Ali; Biyikli, Necmi, E-mail: [National Nanotechnology Research Center (UNAM), Bilkent University, Bilkent, Ankara 06800, Turkey and Institute of Materials Science and Nanotechnology, Bilkent University, Bilkent, Ankara 06800 (Turkey)


    Gallium nitride (GaN) thin films were grown on Si (100), Si (111), and c-plane sapphire substrates at 200 °C via hollow-cathode plasma-assisted atomic layer deposition (HCPA-ALD) using GaEt{sub 3} and N{sub 2}/H{sub 2} plasma as group-III and V precursors, respectively. The main aim of the study was to investigate the impact of substrate on the material properties of low-temperature ALD-grown GaN layers. Structural, chemical, and optical characterizations were carried out in order to evaluate and compare film quality of GaN on different substrates. X-ray reflectivity measurements showed film density values of 5.70, 5.74, and 5.54 g/cm{sup 3} for GaN grown on Si (100), Si (111), and sapphire, respectively. Grazing incidence x-ray diffraction measurements exhibited hexagonal wurtzite structure in all HCPA-ALD grown GaN samples. However, dominant diffraction peak for GaN films grown on Si and sapphire substrates were detected differently as (002) and (103), respectively. X-ray diffraction gonio scans measured from GaN grown on c-plane sapphire primarily showed (002) orientation. All samples exhibited similar refractive index values (∼2.17 at 632 nm) with 2–3 at. % of oxygen impurity existing within the bulk of the films. The grain size was calculated as ∼9–10 nm for GaN grown on Si (100) and Si (111) samples while it was ∼5 nm for GaN/sapphire sample. Root-mean-square surface roughness values found as 0.68, 0.76, and 1.83 nm for GaN deposited on Si (100), Si (111), and sapphire, respectively. Another significant difference observed between the samples was the film growth per cycle: GaN/sapphire sample showed a considerable higher thickness value when compared with GaN/Si samples, which might be attributed to a possibly more-efficient nitridation and faster nucleation of sapphire surface.


    Energy Technology Data Exchange (ETDEWEB)

    Kulkarni, Varsha P.; Som, Debopam; Morrison, Sean [University of South Carolina, Department of Physics and Astronomy, Columbia, SC 29208 (United States); Péroux, Celine; Quiret, Samuel [Aix Marseille Université, CNRS, Laboratoire d’Astrophysique de Marseille, UMR 7326, F-13388, Marseille (France); York, Donald G., E-mail: [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)


    We report Keck/Echellette Spectrograph and Imager and Very Large Telescope/Ultraviolet-Visual Echelle Spectrograph observations of three super-damped Lyα quasar absorbers with H i column densities log N{sub H} {sub i} ≥ 21.7 at redshifts 2 ≲ z ≲ 2.5. All three absorbers show similar metallicities (∼−1.3 to −1.5 dex), and dust depletion of Fe, Ni, and Mn. Two of the absorbers show supersolar [S/Zn] and [Si/Zn]. We combine our results with those for other damped Lyα a absorbers (DLAs) to examine trends between N{sub H} {sub i}, metallicity, and dust depletion. A larger fraction of the super-DLAs lie close to or above the line [X/H] = 20.59 − log N{sub H} {sub i} in the metallicity versus N{sub H} {sub i} plot, compared to the less gas-rich DLAs, suggesting that super-DLAs are more likely to be rich in molecules. Unfortunately, our data for Q0230−0334 and Q0743+1421 do not cover H{sub 2} absorption lines. For Q1418+0718, some H{sub 2} lines are covered, but not detected. CO is not detected in any of our absorbers. For DLAs with log N{sub H} {sub i} < 21.7, we confirm strong correlation between metallicity and Fe depletion, and find a correlation between metallicity and Si depletion. For super-DLAs, these correlations are weaker or absent. The absorbers toward Q0230−0334 and Q1418+0718 show potential detections of weak Lyα emission, implying star formation rates of ∼1.6 and ∼0.7 M{sub ⊙} yr{sup −1}, respectively (ignoring dust extinction). Upper limits on the electron densities from C ii*/C ii or Si ii*/Si ii are low, but are higher than the median values in less gas-rich DLAs. Finally, systems with log N{sub H} {sub i} > 21.7 may have somewhat narrower velocity dispersions Δv{sub 90} than the less gas-rich DLAs, and may arise in cooler and/or less turbulent gas.

  16. Determination the total neutron yields of several semiconductor compounds using various alpha emitters (United States)

    Abdullah, Ramadhan Hayder; Sabr, Barzan Nehmat


    In the present work, the cross-sections of (α,n) reactions available in the literature as a function of α-particle energies for light and medium elements have been rearranged for α-particle energies from near threshold up to 10 MeV in steps of (0.050MeV) using the (Excel and Matlab) computer programs. The obtained data were used to calculate the neutron yields (n/106α) using the quick basic-computer program (Simpson Rules). The stopping powers of alpha particle energies from near threshold to 10 MeV for light and medium elements such as (nat.Be,10B,11B,13C,14N,nat.O,nat.F,nat.Mg,nat.Al,29Si,30Si, nat.P and 46.48Ti) have been calculated using the Zeigler formula. The kinetic energies (Tα) and the branching ratios of each α-emitters such as (211Bi, 210Po, 211Po, 215Po, 217At, 218Rn, 219Rn, 222Rn, 224Ra, 226Ra, 215Th, 228Th, 232U, 234U, 236U, 238U, 238Pu, 239Pu, 241Am, 245Es, 252Fm, 254Fm, 256Fm, 257Fm and 257Md) are taken into consideration to calculate the mean kinetic energy . The polynomial expressions were used to fitting the calculated weighted average of neutron yields (n/106α) for natural light and medium elements such as (Be, B, C, N, O, F, Mg, Al, Si, P and Ti) to determine the adopted neutron yields from the best fitting equation with minimum (CHISQ) at mean kinetic energies of various α-emitters. The total neutron yields (n/s/gx/ppmi) of the mentioned natural light and medium elements have been calculated using the adopted neutron yields (n/106α) from the fitting equations at mean kinetic energies of various α-emitters. The total neutron yields (n/s/gα-emitters/gcompounds) of semiconductor compounds such as (AlN, AlP, BN, BP, SiC, TiO2, BeSiN2, MgCN2, MgSiN2 and MgSiP2) have been calculated by mixing (1gram) of compounds with (1gram) of pure α-emitters using the quick basic computer program. The aim of the present work is to constructed and fabricate the neutron sources theoretically


    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.


    A new rapid method for the determination of {sup 226}Ra in environmental samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used for emergency response or routine sample analyses. The need for rapid analyses in the event of a Radiological Dispersive Device or Improvised Nuclear Device event is well-known. In addition, the recent accident at Fukushima Nuclear Power Plant in March, 2011 reinforces the need to have rapid analyses for radionuclides in environmental samples in the event of a nuclear accident. {sup 226}Ra (T1/2 = 1,620 years) is one of the most toxic of the long-lived alpha-emitters present in the environment due to its long life and its tendency to concentrate in bones, which increases the internal radiation dose of individuals. The new method to determine {sup 226}Ra in environmental samples utilizes a rapid sodium hydroxide fusion method for solid samples, calcium carbonate precipitation to preconcentrate Ra, and rapid column separation steps to remove interferences. The column separation process uses cation exchange resin to remove large amounts of calcium, Sr Resin to remove barium and Ln Resin as a final purification step to remove {sup 225}Ac and potential interferences. The purified {sup 226}Ra sample test sources are prepared using barium sulfate microprecipitation in the presence of isopropanol for counting by alpha spectrometry. The method showed good chemical recoveries and effective removal of interferences. The determination of {sup 226}Ra in environmental samples can be performed in less than 16 h for vegetation, concrete, brick, soil, and air filter samples with excellent quality for emergency or routine analyses. The sample preparation work takes less than 6 h. {sup 225}Ra (T1/2 = 14.9 day) tracer is used and the {sup 225}Ra progeny {sup 217}At is used to determine chemical yield via alpha spectrometry. The rapid fusion technique is a rugged sample digestion method that ensures that any

  18. Snack Consumption among Iranian Children and Adolescents: The CASPIAN-IV Study

    Directory of Open Access Journals (Sweden)



    Full Text Available Background: This study aimed to assess the frequency of consuming different types of snacks among Iranian students according to socio-economic status (SES of their living region.Methods: Data were obtained from the fourth national school-based surveillance survey entitled CASPIAN-IV study. Overall, 14880 school students, aged 6-18 years, were selected through multistage, cluster sampling from rural and urban areas of the of 30 provinces of Iran. The World Health Organization Global School Student Health Survey (WHO-GSHS was used. Data were compared at national/sub-national levels by survey data analysis methods.Results: The participation rate was 90.6%, 13486 students (49.2% girls, mean (SD age of 12.50 (3.36 years completed the study. At national level, fresh fruits were the most common used category of healthy snacks (55.74%, 95% CI: 54.51, 56.96. Boys had more daily consumption of milk (48.65% vs. 43.27%, and girls had more daily consumption of fresh fruits (58.07% vs. 53.47%. Urban residents had lower consumption of vegetables (30.53% vs. 37.55%, dried fruits (18.29% vs. 23.02%, and fresh fruits (45.33% vs. 50.09% than their rural counterparts. Among unhealthy snacks, sweets had the highest daily consumption (34.15%, 95% CI: 33.04, 35.28. Boys had higher consumption of sweetened beverages (22.57% vs. 17.6% and fast foods (3.51% vs. 2.17%. At national level, except than salty snacks (16.24% rural vs.11.83% urban, consumption of other junk snacks had no significant difference between urban and rural residents.Conclusion: Differences in the frequency of consuming healthy and unhealthy snacks according to the SES of the living region, and the choice differences between genders should be considered in planning national health programs. Keywords: Snack, Healthy snack, Junk food, Socio-economic status, Iran 

  19. How does back muscle strength change after posterior lumbar interbody fusion? (United States)

    Lee, Chong-Suh; Kang, Kyung-Chung; Chung, Sung-Soo; Park, Won-Hah; Shin, Won-Ju; Seo, Yong-Gon


    OBJECTIVE There is a lack of evidence of how back muscle strength changes after lumbar fusion surgery and how exercise influences these changes. The aim of this study was to evaluate changes in back muscle strength after posterior lumbar interbody fusion (PLIF) and to measure the effects of a postoperative exercise program on muscle strength and physical and mental health outcomes. METHODS This prospective study enrolled 59 women (mean age 58 years) who underwent PLIF at 1 or 2 spinal levels. To assess the effects of a supervised lumbar stabilization exercise (LSE), the authors allocated the patients to an LSE (n = 26) or a control (n = 33) group. The patients in the LSE group performed the LSEs between 3 and 6 months postoperatively. Back extensor strength, visual analog scale (VAS) scores in back pain, and physical component summary (PCS) and mental component summary (MCS) scores on the 36-Item Short Form Health Survey were determined for the both groups. RESULTS Mean strength of the back muscles tended to slightly decrease by 7.5% from preoperatively to 3 months after PLIF (p = 0.145), but it significantly increased thereafter and was sustained until the last follow-up (38.1%, p muscle strength was similar in the LSE and control groups preoperatively, but it increased significantly more in the LSE group (64.2%) than in the control group (21.7%) at the last follow-up 12 months after PLIF (p = 0.012). At the last follow-up, decreases in back pain VAS scores were more significant among LSE group patients, who had a pain reduction on average of 58.2%, than among control group patients (reduction of 26.1%) (p = 0.013). The patients in the LSE group also had greater improvement in both PCS (39.9% improvement) and MCS (20.7% improvement) scores than the patients in the control group (improvement of 18.0% and 1.1%, p = 0.042 and p = 0.035, respectively). CONCLUSIONS After PLIF, strength in back muscles decreased until 3 months postoperatively but significantly increased after that period. The patients who regularly underwent postoperative LSE had significantly improved back strength, less pain, and less functional disability at 12 months postoperatively.

  20. Liver SULmean at FDG PET/CT: interreader agreement and impact of placement of volume of interest. (United States)

    Viner, Maya; Mercier, Gustavo; Hao, Frank; Malladi, Ashish; Subramaniam, Rathan M


    To evaluate how interreader agreement and the site of the volume of interest (VOI) affect the agreement and variability of liver mean standardized uptake value normalized to lean body mass (SUL(mean)) at fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT). Institutional review board approval was obtained for this HIPAA-compliant retrospective review of PET/CT images and patient records. PET/CT images were reviewed in 116 randomly selected patients who had undergone a baseline PET/CT examination and who had normal livers according to imaging and biochemical test results. A 30-mm-diameter spherical VOI was placed within the right lobe of the liver above, below, and at the level of the main portal vein. Two readers performed all measurements independently. Analysis of variance, intraclass correlation coefficient (ICC) analysis, and Bland-Altman analysis were performed. The mean SUL(mean) was between 2.11 and 2.17 at the upper, portal, and lower levels of the right lobe of the liver. The coefficient of variance was between 21.0% and 23.1%, without significant differences for location, with the least variance in the upper level. The ICC of the two readers varied between 0.98 and 0.99 (95% confidence interval [CI]: 0.97, 0.99; P = .0001) at each level. The greatest precision (narrowest CI) was also in the upper level. Bias was 0.025 ± 0.10 (standard deviation) at the upper level, was 0.004 ± 0.14 at the lower level, and was 0.047 ± 0.10 at the portal vein (P = .02). For each reader, there was almost perfect reliability between the SUL(mean) measurements made at the three levels, with an ICC of 0.98 (95% CI: 0.98, 0.99; P = .0001). Liver SUL(mean) at FDG PET/CT has excellent interreader agreement, with similar values and variance whether measured at the upper, lower, or portal vein levels within the right lobe of the liver. © RSNA, 2013.

  1. Table of radionuclides (Vol. 5 - A = 22 to 244)

    Energy Technology Data Exchange (ETDEWEB)

    Be, M.M.; Chiste, V.; Dulieu, C.; Mougeot, X.; Browne, E.; Chechev, V.; Kuzmenko, N.; Kondev, F.; Luca, A.; Galan, M.; Arinc, A.; Huang, X.


    have agreed on the methodologies to be used and the CD-ROM included with this monograph contains the evaluators' comments for each radionuclide in addition to the data tables included in the monograph. This volume includes the evaluation of the following radionuclides: {sup 22}Na, {sup 40}K, {sup 75}Se, {sup 124}Sb, {sup 207}Bi, {sup 211}Bi, {sup 217}At, {sup 222}Ra, {sup 225}Ac, {sup 228}Ra, {sup 231}Th, {sup 232}Th, {sup 233}Th, {sup 233}Pa, {sup 234}Th, {sup 235}U, {sup 237}U, {sup 238}Pu, {sup 240}Pu, {sup 241}Am, {sup 242}Pu, {sup 242}Am, {sup 243}Am, {sup 244}Am, {sup 244}Am{sup m}. Primary recommended data comprise half-lives, decay modes, X-rays, gamma-rays, electron emissions, alpha -and beta- particle transitions and emissions, and their uncertainties

  2. Induction of Chromosome Aberrations in Human Lymphocytes by Irradiation WithβParticles From Low-Doses Tritiated Water%低剂量氚水β射线对人体外周血淋巴细胞染色体的影响

    Institute of Scientific and Technical Information of China (English)

    邓冰; 成琼; 杜阳; 杨勇


    通过染色体非稳定性畸变来研究低剂量氚水β射线的生物效应。将人体外周血与氚水混合培养24 h和48 h,共培养72 h后获细胞得到与氚水作用后染色体畸变的频率并与相同剂量下60 Coγ射线的细胞效应对比。将实验结果进行回归方程拟合,得到 HTOβ射线的最佳回归方程Y=(0.001±0.004)+(0.062±0.018)D+(0.053±0.010)D2(n=3,r2=0.995,P<0.01);通过比较 HTO 与γ射线的最佳回归方程可知,方程系数的主要区别在b值,提示在低剂量的情况下β射线诱发畸变的能力更强。将60 Coγ射线作为参考可得 HTOβ射线的相对生物效能(RBE)最大值出现在0.06 Gy,为2.17,RBE值随着剂量的增大而减小。%The yield of unstable chromosome aberration induced in human lymphocytes byβparticles from low-doses HTO has been measured.HTO was mixed with heparinised blood in various amounts so that dose of 6.24×10-4 Gy to 1.23 Gy were delivered in 24 h and 48 h. After culturing for 72 h,the dicentric yield was measured as a function of dose to the blood and compared with data from 60 Coγradiation.Using a linear-quadratic dose-effect relation to fit the experimental data,a significant linear contribution Y=(0.001 ±0.004)+(0.062 ± 0.0 1 8 )D+(0.0 5 3 ± 0.0 1 0 )D2 (n=3 ,r2=0.9 9 5 ,P<0.0 1 )was found.The main difference between the coefficients forβandγradiation is in the b values,indicating that HTOβrays are more efficient,particularly at low doses.In accord with the theory of dual radiation,the RBE of HTOβparticles relative toγrays is 2.17 at 0.06 Gy and decreases with increasing dose.

  3. Effects of Ionizing Radiation on Murine Gene Expression in Skin and Bone (United States)

    Terada, Masahiro; Schreurs, Ann-Sofie; Shirazi-Fard, Yasaman; Alwood, Joshua; Tahimic, Candice; Sowa, Marianne B.; Globus, Ruth K.


    Long duration spaceflight causes a negative calcium balance and reduces bone density in astronauts. The potential for exposure to space radiation to contribute to lasting decrements in bone mass is not yet understood. Sustained changes to bone mass have a relatively long latency for development, however skin is a radiation sensitive organ and changes in skin gene expression may serve as an early radiation biomarker of exposures and may correlate with adverse effects on skeletal tissue. Previous studies have shown that FGF18 gene expression levels of hair follicles collected from astronauts on the ISS rose over time. In the hair follicle, FGF18 signaling mediates radioresistance in the telogen by arresting the cell cycle, and FGF18 has the potential to function as a radioprotector. In bone, FGF18 appears to regulate cell proliferation and differentiation positively during osteogenesis and negatively during chondrogenesis. Cellular defense responses to radiation are shared by a variety of organs, hence in this study, we examined whether radiation induced gene expression changes in skin may be predictive of the responses of skeletal tissue to radiation exposure. We have examined oxidative stress and growth arrest pathways in mouse skin and long bones by measuring gene expression levels via quantitative polymerase chain reaction (qPCR) after exposure to total body irradiation (TBI). To investigate the effects of irradiation on gene expression, we used skin and femora (cortical shaft) from the following treatment groups: control (normally loaded, sham-irradiated), and TBI (0.5 Gy Fe-56 600 MeV/n and 0.5 Gy H-1 150 MeV/n). Animals were euthanized one and 11 days post-IR. Statistical analysis was performed via a Student's ttest. In skin samples one day after IR, skin expression of FGF18 was significantly greater (3.8X) than sham-irradiated controls (3.8X), but did not differ 11 days post TBI. Expression levels of other radiation related genes (Nfe2l2, Trp53, Cdkn1a, FoxO3, Gadd45g, SOD1), was not different due to TBI at either time point. In bone (femora) TBI significantly increased (3.8X) expression of the pro-bone resorption cytokine, MCP-1, one day after TBI. FGF18 expression in skin and MCP- 1 expression in bone were found to be positively correlated (P less than 0.002, r=0.8779). Further, microcomputed tomography analysis of tibae from these animals showed reduced fractional cancellous bone volume (-21.7%) at 11 days post exposure. These results suggest that early radiation induced changes in FGF18 gene expression in skin may have value for predicting subsequent loss of cancellous bone mass.

  4. Velocidade de estabelecimento de acessos de amendoim forrageiro na Amazônia Ocidental Speed of establishment of accessions of forage peanut in the Western Amazon

    Directory of Open Access Journals (Sweden)

    Judson Ferreira Valentim


    Full Text Available O objetivo deste estudo foi avaliar a velocidade de estabelecimento de acessos de amendoim forrageiro (Arachis repens e Arachis pintoi, visando selecionar materiais adaptados aos sistemas intensivos de produção pecuária do Acre. O delineamento experimental utilizado foi de blocos casualizados, com quatro repetições. Os tratamentos consistiram de dois acessos de A. repens, sete acessos e duas cultivares de Arachis pintoi identificados como promissores para as condições ambientais de Rio Branco, Acre. Foi adotado como testemunha A. pintoi cv. Amarillo. Os acessos Ap 65, Ap 39 e Ar 10, com desempenho semelhante às cultivares Amarillo e Belmonte, destacaram-se por apresentar excelente velocidade de estabelecimento, com índice de sobrevivência das mudas e cobertura do solo superiores a 80% e comprimento dos estolões acima de 85 cm, respectivamente, aos 50, 70 e 120 dias após o plantio. Estes genótipos apresentaram produtividade de matéria seca (MS superior a 2.300 kg/ha, taxas de acúmulo de MS iguais ou superiores a 20 kg/ha/dia e teor de proteína bruta variando entre 17,9 e 21,7%, no final do período de estabelecimento. Entre os quatro grupos heteróticos, o formado pelo acesso Ap 39 destacou-se dos demais, por apresentar valores médios a altos para todas as características avaliadas, de acordo com a análise de agrupamento realizada pelo Método de Otimização de Tocher, com base na distância generalizada de Mahalanobis. Para que os materiais promissores possam ser recomendados para uso nos sistemas intensivos de produção de bovinos no Acre, devem ser desenvolvidos estudos adicionais com relação à: 1 produtividade e qualidade de MS nos períodos chuvoso e seco; 2 ocorrência de pragas e doenças; 3 produção de sementes; 4 adaptação a solos de baixa permeabilidade; 5 compatibilidade com gramíneas forrageiras e espécies arbóreas e arbustivas perenes; 6 produção animal e persistência sob pastejo.The objective of this study was to evaluate the speed of establishment of accessions of Arachis repens and Arachis pintoi with the purpose of selecting materials capable of producing adequate quantities of high quality forage, according to the requirements of the intensive cattle production systems of Acre. The experimental design was a randomized block with four replications. The treatments consisted of two accessions of Arachis repen, seven accession and two cultivars of Arachis pintoi, identified as promising for the environmental conditions of Rio Branco, Acre. The control treatment was A. pintoi cv. Amarillo. The accessions Ap 65, Ap 39 and Ar 10, with performance similar to the cultivars Amarillo and Belmonte, were selected because of their excellent speed of establishment with index of survival of stolon and rhizome plantings and ground cover higher than 80% and length of stolons above 85 cm, respectively, 50, 70 and 120 days after planting. These genotypes showed DM yields above 2,300 kg/ha, DM accumulation rates equal or superior to 20 kg/ha/day and crude protein content ranging from 17.9 to 21.7%, at the end of the establishment period. Among the four heterotic groups, the one consisting of accession Ap 39 outranked the others by presenting high mean values for all the characteristics evaluated according to the cluster analysis by the Tocher Optimization Method, based on the generalized Mahalanobis. For the recommendation of the promising accessions for use in the intensive cattle production systems in Acre, additional studies should be conducted in relation to: 1 dry matter yield and quality during the rainy and dry seasons; 2 occurrence of pests and diseases; 3 seed production; 4 adaptation to low permability soils; 5 compatibility with grasses and shrub and tree species; 6 animal production and persistence under grazing.

  5. Effects of Different Cover Types on Soil Water, Temperature and Potato Yield in Double Rice Cropping Area%南方稻田冬季马铃薯覆盖栽培对土壤水热及产量的影响

    Institute of Scientific and Technical Information of China (English)

    林叶春; 卜洪震; 胡跃高; 曾昭海; 肖小平; 唐海明; 杨光立


    土壤水热状况是影响南方稻区冬种马铃薯生长和产量的重要环境因素.本文研究了露地无覆盖(对照)、稻草、渗水膜、普通膜和黑色膜覆盖处理对土壤水热、马铃薯生长和产量的影响.结果表明:马铃薯全生育期内各处理0cm-20 cm土壤温度依次为普通膜>渗水膜>黑色膜>稻草>对照,表明覆盖可提高表层(0cm-20 cm)土壤温度.稻草覆盖处理比对照提高0cm-5 cm土壤含水量5.9%,达显著性差异水平(p<0.05);3种膜覆盖处理比对照显著降低了0cm-15 cm土壤含水量;各覆盖处理对20cm-25cm土壤含水量影响不显著.渗水膜覆盖比对照降低0cm-5 cm土壤容重2.0%,稻草覆盖比对照降低了15cm-20 cm土壤客重4.0%.渗水膜覆盖与对照的马铃薯出苗率基本一致,但稻草覆盖使马铃薯出苗率降低21.7%.渗水膜和黑色膜覆盖比对照显著增产22.0%和6.9%,稻草和普通膜减产21.2%和19.5%.渗水膜和黑色膜覆盖比对照提高大薯个数79.0%和31.6%;渗水膜覆盖提高马铃薯块茎商品率44.1%,并提高块茎淀粉含量74%.试验表明:南方稻田冬季马铃薯渗水膜覆盖栽培,对改善土壤水热状况及提高马铃薯产量和商品性具有重要作用,是冬季马铃薯优质高产栽培的重要措施.%Soil water and soil temperature are two important environmental factors, which affect winter potato production in double rice cropping area. This research was carried out to compare with the effects of different mulching types on soil water, soil temperature and winter potato production in Changsha County of Hunan Province. In this study, four mulching type, I.e. Rice straw (RS), water-permeability plastic film (WPPF), common plastic film (CPF), black plastic film (BPF), and no-covering as control (CK). Results showed as follows: mulching rise the soil temperature at 0 cm -20 cm layer, and effects of different mulching types showed CPF>WPPF>BPF>RS>CK. At 0 cm -5 cm layer, RS significantly improved soil moisture by 5.9% than CK at 5% level; mulching film (I.e. WPPF, CPF and BPF) significantly decreased soil moisture at 0 cm -15 cm layer, but had no significant effect on it at 20 cm -25 cm layer. WPPF significantly reduced the soil bulk density at 0 cm -5 cm layer by 2.0%, and RS significantly decreased it than CK by 4% at 15 cm -20 cm layer at 5% significance level. Mulching was the disadvantage of seedling emergence of potato, except WPPF. RS significantly decreased the rate of potato seedling emergence by 21.7% at 5% significance level. WPPF and BPF significantly increased tuber yield than CK by 22.0% and 6.9%; however, RS and CPF significantly decreased it by 21.2% and 19.5% at 5% probability level. WPPF obtained the maximum big potatoes, the highest rate of economic potato and the highest starch content of tuber potato among other's treatments. Our results suggest that WPPF had some advantages in maintaining soil water content and soil temperature and enhanced the yield and quality of winter potato tubers in double rice cropping area.

  6. The correlation of autonomic dysfunction and intra-dialyttc hypotension in maintenance hemodialysis patients%维持性血液透析患者自主神经功能异常与透析中低血压的关系

    Institute of Scientific and Technical Information of China (English)

    徐静; 程叙扬; 金其庄; 曹立云; 刘莉; 左力


    Objective To investigate the correlation between autonomic nervous system dysfunction and intra-dialytic hypotension (IDH) in maintenance hemodialysis (MHD) patients by analyzing the heart rate variability (HRV). Methods Blood pressure changes were recorded and dynamic electrocardiography (Holter) was conducted in 60 MHD patients during a hemodialysis session. Patients were assigned into IDH group or control group. The difference in power spectra of HRV between the two groups was analyzed. The normalized low-frequency (LFn) component of HRV was assumed to be the index of sympathetic activity, and the normalized high-frequency (HFn) component to be the index of parasympathetic activity. The LF/HF ratio then indirectly represents the balance level between sympathetic and vagal activities. A logistic regression model was set up to analyze the value of LFn for the prediction of IDH, using IDH as the outcome variable, and parameters including sex, age, hemodialysis age, diabetes as the primary disease, cardiac index, central blood volume/body weigh ratio, ultrafiltration volume/body weight ratio and LFn before hemodialysis as the prediction variables. Results In control group, LFn and LF/HF ratio elevated continually and gradually in a dialysis session (The median of LFn was 65.47nu at the beginning of hemodialysis, 73.79nu after 210 minutes, P=0.001; The median of LF/HF ratio was 2.17 at the beginning, and 3.98 after 210 minutes, P < 0.001), whereas HFn reduced gradually (The median of HFn was 30.06nu at the beginning and 19.43nu after 210 minutes, P=0.002). In IDH group, however, the above indexes changed inconsistently, and LFn was lower than that of control group in the entire hemodialysis session. Logistic regression model showed that LFn was a predictor for IDH (OR= 0.943,95%C/=0.894~0.966) after adjustment by the above demographic characteristics and basic clinical situations. Conclusion In MHD patients, the presence of IDH may relate to the incapability of continuous and consistent increase of sympathetic activity along with blood volume reduction during hemodialysis. Decrease of basal sympathetic activity before hemodialysis is an independent risk factor for IDH, suggesting that abnormal autonomic nervous function is one of the important causes leading to IDH.%目的以心率变异性(heart rate variability,HRV)为观察指标,分析维持性血液透析(maintenance hemodialysis,MHD)患者的自主神经功能异常与透析中低血压(intradialytichypotension,IDH)的关系.方法在透析过程中同步监测患者的血压和动态心电图,依据是否发生IDH将60例患者分为2组(血压下降组和对照组),比较2组的HRV指标,其中LFn代表交感神经活性,HFn代表迷走神经活性,LF/HF代表2者之间的平衡状态.以发生IDH为结果变量,以性别、年龄、透析龄、原发病是否糖尿病、心脏指数、中心血容量占体质量百分比、超滤量占体质量百分比和透析前LFn为预测变量,建立Logistic回归模型分析LFn对IDH的预测价值.结果对照组在透析过程中LFn水平和LF/HF比值逐渐升高,且升高趋势稳定(LFn中位数:透析开始时65.47nu,210min时73.79nu,P=0.001;LF/HF中位数:开始时2.17,210min时3.98,P<0.001),HFn的水平则逐渐减低(HFn中位数:透析开始30.06nu,210min时19.43nu,P=0.002),而血压下降组的上述指标变化趋势不稳定,其中LFn在整个透析过程中都始终低于对照组.logistic回归模型显示,在校正了上述人口学特征和临床基础情况后,LFn对IDH的发生仍有预测价值,OR值为0.943(95%CI0.894~0.966).结论维持性血液透析患者交感神经活性在透析过程不能随血容量的下降持续、稳定的增高,与IDH的发生有密切关系;透析前交感神经活性的基础水平减低是IDH的独立危险因素,表明自主神经功能异常是导致透析中低血压的重要原因之一.

  7. Discólisis percutánea con ozono: nuestra experiencia Percutaneous ozone discolysis: our experience

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    M. Castro


    Full Text Available Objetivo: Demostrar la eficacia y seguridad clínica de la discólisis percutánea con ozono en el tratamiento de la hernia discal lumbar sintomática. Material y métodos: Estudio observacional prospectivo en 41 pacientes diagnosticados de hernia discal lumbar sintomática, a los que se les realizó un total de 49 discólisis percutáneas con ozono durante el período comprendido entre febrero de 2004 y febrero de 2009. Todas las discólisis se realizaron en quirófano, bajo control radioscópico, con medidas de asepsia habitual, anestesia local y sedación. Se administró ozono intradiscal (5 a 7 ml, epidural (5 a 7 ml y perirradicular (5 a 7 ml a una concentración de 27 µg. En todos los casos se administró quimioprofilaxis con 1.500 mg de cefuroxima. La eficacia del tratamiento se basó en el control del dolor según la escala visual analógica basal (EVA 0, a los 30 días (EVA 1, a los 90 días (EVA 3 y a los 6 meses (EVA 6 de las discólisis y mediante el test de Lattinen evaluado antes del tratamiento (TLT 0 y al final del estudio (TLT 1. Todos los pacientes fueron preguntados acerca de posibles efectos secundarios y finalmente se registró el grado de satisfacción. Resultados: Se realizaron 49 discólisis percutáneas con ozono en 41 pacientes. La EVA media inicial fue de 7,37 ± 0,96 y la evolución al mes, a los 3 y a los 6 meses fue: 2,41 ± 2,17, 1,80 ± 2,31 y 2,05 ± 2,45, respectivamente, con diferencia estadísticamente significativa en los 3 cortes. El índice de Lattinen medio inicial fue de 12,68 ± 2,32 y pasó a 6,07 ± 2,91 a los 6 meses, con una reducción también estadísticamente significativa. Solamente 5 pacientes (12,2% presentaron efectos adversos que consistieron en 4 cefaleas transitorias leves y un neumoencéfalo bastante incapacitante que obligó al paciente a guardar reposo en cama durante 1 semana hasta su reabsorción espontánea. En cuanto a la satisfacción expresada por los pacientes fue buena para 35 (85,4%, regular para 4 (9,8%, y solamente 2 (4,9% la calificaron de mala. Conclusiones: La discólisis percutánea con ozono se muestra como una técnica eficaz y segura en el tratamiento del dolor lumbar irradiado secundario a hernia de disco lumbar.Objective: To demonstrate the safety and effectiveness of percutaneous discolysis using ozone in the treatment of symptomatic lumbar hernia. Material and methods: We performed a prospective observational study in 41 patients diagnosed with symptomatic lumbar hernia, in whom we performed 49 percutaneous discolysis procedures introducing ozone in the lumbar region between February 2004 and February 2009. All the procedures were performed in the operating room under radiological guidance, with aseptic conditions, local anaesthesia and sedation. The ozone was introduced into the lumbar disc (5 to 7 ml, in the epidural (5 to 7 ml and periradicular spaces (5 to 7 ml at a concentration of 27 Ìg. In all patients, 1500 mg of cefuroxime was administrated intravenously as a prophylactic measure. The effectiveness of the treatment was based on pain control according to the visual analogue scale before the procedure (VAS 0, at 30 days (VAS 1, at 90 days (VAS 3 and at 6 months (VAS 6, and by means of Lattinen's test before treatment and at the end of the study. All the patients were asked about the possible adverse effects of the treatment and a survey was carried out on patient satisfaction with the technique. Results: We performed 49 percutaneous ozone discolysis procedures in 41 patients. The initial mean VAS was 7.37 ± 0.96 and subsequent values were 2.41 ± 2.17 at 1 month, 1.80 ± 2.31 at 3 months and 2.05 ± 2.45 at 6 months, with statically significant differences in the three measurements. The initial mean Lattingen index was 12.68 ± 2.32 and was 6.07 ± 2.91 at 6 months, representing a statically significant reduction. Adverse effects occurred in only five patients (12.2%: four mild transient headaches and one symptomatic pneumoencephalos, requiring bed rest for 1 week until spontaneous reabsorption. The degree of satisfaction was good in 35 patients (85.4%, acceptable in four (9.8% and bad in only two patients (4.9%. Conclusions: Percutaneous ozone discolysis is a safe and effective technique in the treatment of symptomatic lumbar hernia.

  8. Radiographic analysis and clinical significance of adolescent idiopathic cervical kyphosis%青少年特发性颈椎后凸畸形的影像学特征及其临床指导意义

    Institute of Scientific and Technical Information of China (English)

    沈晓龙; 田野; 东人; 曹鹏; 周许辉; 袁文


    Objective:To investigate the radiographic characteristics and clinical significance of adolescent id-iopathic cervical kyphosis and the reliability for evaluating cervical kyphosis.Method: Twenty -three adolescent patients with idiopathic cervical kyphosis were collected in this study .The causes of the disease remained un-known.The Cobb angle of kyphosis,posterior tangent angle of each segment,levels resulted in kyphosis and the apex of the kyphosis were measured on lateral radiographs.Kyphosis index (KI) and curvature index (CI) which were included were used to evaluate the severity of kyphosis.Result: Eleven (47.8%) patients had kyphosis level at C2-5,five (21.7%) at C2-6,and seven (30.4%) at C3-6.The mean vertebral number in kyphosis was 4.2(mean,3.2 levels).The apex of the kyphosis was sited at C4(69.57%) in 16 patients and C5 (30.43%) in 7 patients.Global Cobb angles(C2-C7) ranged from 4.7° to 68.3°(mean,35.60±14.5°) ,and posterior tangent angle ranged from 9.8° to 75.1° (mean,37.1°±16.7° ).The Cobb angles of kyphosis ranged from 21.8° to 96.3°(mean,53.7°±19.70) in two-line Cobb method,and 19.8° to 120.6°(mean,54.8°±23.9°) in Harrison posterior tangent method.CI ranged from 8.6 to 79.8 (mean,37.7±20.5) and KI ranged from 15.2 to 141.9 (mean,53.0±29.1),which showed significant positive correlation between KI and kyphosis angle.Conclusion: In adolescent idiopathic cervical kyphosis,the apex of kyphosis locates at the posterosuperior edge of vertebrae,and only part of vertebrae are involved.KI can accurately depict the severity of cervical kyphosis.%分析青少年特发性颈椎后凸畸形患者的影像学特征,探讨评价后凸曲度的可靠方法.方法:对23例青少年特发性颈椎后凸畸形患者的影像学资料进行分析,在矢状位X线片上测量C2 ~C7的后切线角及Cobb角、后凸节段后切线角及Cobb角、后凸累及椎体数、后凸顶点位置,计算颈椎曲度指数(CI)及后凸指数(KI),并进行相关性分析.结果:本组后凸节段C2~C5 11例,C2~C6 5例,C3~C6 7例,后凸平均累及椎体4.2个(平均累及3.2个椎间隙);后凸顶点均位于椎体的后上缘,位于C4 16例(69.57%),C5 7例(30.43%);C2~C7后切线角9.8°~75.1°,平均37.1°±16.7°;C2~C7的Cobb角为4.7°~68.3°,平均35.6°±14.5°;后凸节段后切线角19.8°~120.6°,平均54.8°±23.9°;后凸节段Cobb角21.8°~96.3°,平均53.7°±19.7°;颈椎曲度指数(CI)8.6~79.8,平均37.7±20.5;后凸指数(K1)15.2~141.9,平均53.0±29.1.统计学分析显示,后凸指数与后凸角度呈高度正相关.结论:青少年特发性颈椎后凸畸形的后凸顶点位于椎体的后上缘,后凸范围仅累及部分颈椎节段,后凸节段的后凸指数可准确地反映后凸畸形的严重程度.