WorldWideScience

Sample records for highest energy cr

  1. Highest energy cosmic rays

    International Nuclear Information System (INIS)

    Nikolskij, S.

    1984-01-01

    Primary particles of cosmic radiation with highest energies cannot in view of their low intensity be recorded directly but for this purpose the phenomenon is used that these particles interact with nuclei in the atmosphere and give rise to what are known as extensive air showers. It was found that 40% of primary particles with an energy of 10 15 to 10 16 eV consist of protons, 12 to 15% of helium nuclei, 15% of iron nuclei, the rest of nuclei of other elements. Radiation intensity with an energy of 10 18 to 10 19 eV depends on the direction of incoming particles. Maximum intensity is in the direction of the centre of the nearest clustre of galaxies, minimal in the direction of the central area of our galaxy. (Ha)

  2. Where do the highest energy CR's come from? and How does the Milky Way affect their arrival directions?

    Directory of Open Access Journals (Sweden)

    Kronberg Philipp

    2013-06-01

    Full Text Available A “grand magnetic design” for the Milky Way disk clearly emerges within ~1.5 kpc of the Galactic mid-plane near the Sun [1], and reveals a pitch angle of −5.5°. directed inward from the Solar tangential. This pitch angle can be expected to differ for Galactic disc locations other than ours. Above ~1.5 kpc, the field geometry is completely different, and its 3-D structure is not yet completely specified. However it appears that the UHECR (> 5 · 1019 eV propagation to us is not much affected by the halo field, at least for protons. I discuss new multi-parameter analyses of UHECR deflections which provide a conceptual “template” for future interpretations of energy-species-direction data from AUGER, HiRes etc., and their successors [2]. I show how the strength and structure of the cosmologically nearby intergalactic magnetic field, BIGM, is now well-estimated out to D ~5 Mpc from the Milky Way: − 20nG. These are the first VHECR data-based estimates of BIGM on nearby supragalactic scales, and are also important for understanding and modeling CR propagation in the more distant Universe. CR Acceleration to the highest energies is probably a natural accompanying phenomenon of Supermassive Black Hole (SMBH-associated jets and lobes [3]. I briefly describe what we know about magnetic configurations in these candidate sites for UHECR acceleration, and the first direct estimate of an extragalactic Poynting flux current, ~3 · 1018 Amperes [4, 5]. This number connects directly to SMBH accretion disk physics, and leads directly to ideas of how VHECR acceleration in jets and lobes, possibly involving magnetic reconnection, is likely to be common in the Universe. It remains to be fully understood.

  3. Catching the Highest Energy Neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Stanev, Todor [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)

    2011-08-15

    We briefly discuss the possible sources of ultrahigh energy neutrinos and the methods for their detection. Then we present the results obtained by different experiments for detection of the highest energy neutrinos.

  4. Electrodynamics at the highest energies

    International Nuclear Information System (INIS)

    Klein, Spencer R.

    2002-01-01

    At very high energies, the bremsstrahlung and pair production cross sections exhibit complex behavior due to the material in which the interactions occur. The cross sections in dense media can be dramatically different than for isolated atoms. This writeup discusses these in-medium effects, emphasizing how the cross section has different energy and target density dependencies in different regimes. Data from SLAC experiment E-146 will be presented to confirm the energy and density scaling. Finally, QCD analogs of the electrodynamics effects will be discussed

  5. The highest energies in the Universe

    International Nuclear Information System (INIS)

    Rebel, H.

    2006-01-01

    There are not many issues of fundamental importance which have induced so many problems for astrophysicists like the question of the origin of cosmic rays. This radiation from the outer space has an energy density comparable with that of the visible starlight or of the microwave background radiation. It is an important feature of our environment with many interesting aspects. A most conspicuous feature is that the energy spectrum of cosmic rays seems to have no natural end, though resonant photopion production with the cosmic microwave background predicts a suppression of extragalactic protons above the so-called Greisen-Zatsepin-Kuz’min cutoff at about EGZK = 5 × 10"1"9 eV. In fact the highest particle energies ever observed on the Earth, stem from observations of Ultrahigh Energy Cosmic Rays (E > 3 × 10"1"9 eV). But the present observations by the AGASA and HiRes Collaborations, partly a matter of debate, are origin of a number of puzzling questions, where these particles are coming from, by which gigantic acceleration mechanism they could gain such tremendous energies and how they have been able to propagate to our Earth. These questions imply serious problems of the understanding of our Universe. There are several approaches to clarify the mysteries of the highest energies and to base the observations on larger statistical accuracy. The Pierre Auger Observatory, being in installation in the Pampa Amarilla in the Province Mendoza in Argentina, is a hybrid detector, combining a large array of water Cerenkov detectors (registering charged particles generated in giant extended air showers) with measurements of the fluorescence light produced during the air shower development. This contribution will illustrate the astrophysical motivation and the current status of the experimental efforts, and sketch the ideas about the origin of these particles.

  6. Origin of the highest energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Biermann, Peter L.; Ahn, Eun-Joo; Medina-Tanco, Gustavo; Stanev, Todor

    2000-06-01

    Introducing a simple Galactic wind model patterned after the solar wind we show that back-tracing the orbits of the highest energy cosmic events suggests that they may all come from the Virgo cluster, and so probably from the active radio galaxy M87. This confirms a long standing expectation. Those powerful radio galaxies that have their relativistic jets stuck in the interstellar medium of the host galaxy, such as 3C147, will then enable us to derive limits on the production of any new kind of particle, expected in some extensions of the standard model in particle physics. New data from HIRES will be crucial in testing the model proposed here.

  7. Directional clustering in highest energy cosmic rays

    International Nuclear Information System (INIS)

    Goldberg, Haim; Weiler, Thomas J.

    2001-01-01

    An unexpected degree of small-scale clustering is observed in highest-energy cosmic ray events. Some directional clustering can be expected due to purely statistical fluctuations for sources distributed randomly in the sky. This creates a background for events originating in clustered sources. We derive analytic formulas to estimate the probability of random cluster configurations, and use these formulas to study the strong potential of the HiRes, Auger, Telescope Array and EUSO-OWL-AirWatch facilities for deciding whether any observed clustering is most likely due to nonrandom sources. For a detailed comparison to data, our analytical approach cannot compete with Monte Carlo simulations, including experimental systematics. However, our derived formulas do offer two advantages: (i) easy assessment of the significance of any observed clustering, and most importantly, (ii) an explicit dependence of cluster probabilities on the chosen angular bin size

  8. Challenges for highest energy circular colliders

    CERN Document Server

    Benedikt, M; Wenninger, J; Zimmermann, F

    2014-01-01

    A new tunnel of 80–100 km circumference could host a 100 TeV centre-of-mass energy-frontier proton collider (FCC-hh/VHE-LHC), with a circular lepton collider (FCCee/TLEP) as potential intermediate step, and a leptonhadron collider (FCC-he) as additional option. FCC-ee, operating at four different energies for precision physics of the Z, W, and Higgs boson and the top quark, represents a significant push in terms of technology and design parameters. Pertinent R&D efforts include the RF system, topup injection scheme, optics design for arcs and final focus, effects of beamstrahlung, beam polarization, energy calibration, and power consumption. FCC-hh faces other challenges, such as high-field magnet design, machine protection and effective handling of large synchrotron radiation power in a superconducting machine. All these issues are being addressed by a global FCC collaboration. A parallel design study in China prepares for a similar, but smaller collider, called CepC/SppC.

  9. Golden mean energy equals highest atomic electron orbital energy

    Energy Technology Data Exchange (ETDEWEB)

    Malinowski, Leonard J. [Interdisciplinary Research Club, P.O. Box 371, Monroeville, PA 15146 (United States)], E-mail: LJMalinowski@gmail.com

    2009-12-15

    The golden mean numerical value {phi} = 0.5({radical}5 - 1) has been given a physical manifestation through E infinity theory. This short paper relates the golden mean energy 0.618034 MeV to atomic electron orbitals.

  10. Golden mean energy equals highest atomic electron orbital energy

    International Nuclear Information System (INIS)

    Malinowski, Leonard J.

    2009-01-01

    The golden mean numerical value φ = 0.5(√5 - 1) has been given a physical manifestation through E infinity theory. This short paper relates the golden mean energy 0.618034 MeV to atomic electron orbitals.

  11. The highest energy cosmic rays, photons and neutrinos

    International Nuclear Information System (INIS)

    Zas, Enrique

    1998-01-01

    In these lectures I introduce and discuss aspects of currently active fields of interest related to the production, transport and detection of high energy particles from extraterrestrial sources. I have payed most attention to the highest energies and I have divided the material according to the types of particles which will be searched for with different experimental facilities in planning: hadrons, gamma rays and neutrinos. Particular attention is given to shower development, stochastic acceleration and detection techniques

  12. Z-burst scenario for the highest energy cosmic rays

    International Nuclear Information System (INIS)

    Fodor, Z.

    2002-10-01

    The origin of highest energy cosmic rays is yet unknown. An appealing possibility is the so-called Z-burst scenario, in which a large fraction of these cosmic rays are decay products of Z bosons produced in the scattering of ultrahigh energy neutrinos on cosmological relic neutrinos. The comparison between the observed and predicted spectra constrains the mass of the heaviest neutrino. The required neutrino mass is fairly robust against variations of the presently unknown quantities, such as the amount of relic neutrino clustering, the universal photon radio background and the extragalactic magnetic field. Considering different possibilities for the ordinary cosmic rays the required neutrino masses are determined. In the most plausible case that the ordinary cosmic rays are of extragalactic origin and the universal radio background is strong enough to suppress high energy photons, the required neutrino mass is 0.08 eV ≤ m ν ≤ 0.40 eV. The required ultrahigh energy neutrino flux should be detected in the near future by experiments such as AMANDA, RICE or the Pierre Auger Observatory. (orig.)

  13. Academic Training - Tevatron: studying pp collisions at the highest energy

    CERN Multimedia

    2006-01-01

    ACADEMIC TRAINING LECTURE SERIES 15, 16, 17, 18 May Main Auditorium, bldg. 500 on 15, 16, 17 May - Council Chamber on 18 May Physics at the Tevatron B. HEINEMANN, Univ. of Liverpool, FERMILAB Physics Results from the Tevatron The Tevatron proton-antiproton collider at Fermilab in the US is currently the world's highest energy collider. At the experiments CDF and D0 a broad physics programme is being pursued, ranging from flavour physics via electroweak precision measurements to searches for the Higgs boson and new particles beyond the Standard Model. In my lecture I will describe some of the highlight measurements in the flavour, electroweak and searches sectors, and the experimental techniques that are used. ENSEIGNEMENT ACADEMIQUE ACADEMIC TRAINING Françoise Benz 73127 academic.training@cern.ch If you wish to participate in one of the following courses, please tell to your supervisor and apply electronically from the course description pages that can be found on the Web at: http://www.cern.ch/...

  14. Correlation of the highest-energy cosmic rays with the positions of nearby active galactic nuclei

    NARCIS (Netherlands)

    Abraham, J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.; Andringa, S.; Anzalone, A.; Aramo, C.; Argiro, S.; Arisaka, K.; Armengaud, E.; Arneodo, F.; Arqueros, F.; Asch, T.; Asorey, H.; Assis, P.; Atulugama, B. S.; Aublin, J.; Ave, M.; Avila, G.; Baecker, T.; Badagnani, D.; Barbosa, A. F.; Barnhill, D.; Barroso, S. L. C.; Bauleo, P.; Beatty, J. J.; Beau, T.; Becker, B. R.; Becker, K. H.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bergmann, T.; Bernardini, P.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanch-Bigas, O.; Blanco, F.; Blasi, P.; Bleve, C.; Bluemer, H.; Bohacova, M.; Bonifazi, C.; Bonino, R.; Brack, J.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Burton, R. E.; Busca, N. G.; Caballero-Mora, K. S.; Cai, B.; Camin, D. V.; Caramete, L.; Caruso, R.; Carvalho, W.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chye, J.; Clay, R. W.; Colombo, E.; Conceicao, R.; Connolly, B.; Contreras, F.; Coppens, J.; Cordier, A.; Cotti, U.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Donato, C.; Bg, S. J. de Jong; De La Vega, G.; de Mello, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; del Peral, L.; Deligny, O.; Della Selva, A.; Delle Fratte, C.; Dembinski, H.; Di Giulio, C.; Diaz, J. C.; Diep, P. N.; Dobrigkeit, C.; D'Olivo, J. C.; Dong, P. N.; Dornic, D.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; DuVernois, M. A.; Engel, R.; Epele, L.; Escobar, C. O.; Etchegoyen, A.; Luis, P. Facal San; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferrer, F.; Ferry, S.; Fick, B.; Filevich, A.; Filipcic, A.; Fleck, I.; Fracchiolla, C. E.; Fulgione, W.; Garcia, B.; Gaimez, D. Garcia; Garcia-Pinto, D.; Garrido, X.; Geenen, H.; Gelmini, G.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Albarracin, F. Gomez; Berisso, M. Gomez; Herrero, R. Gomez; Goncalves, P.; do Amaral, M. Goncalves; Gonzalez, D.; Gonzalezc, J. G.; Gonzalez, M.; Gora, D.; Gorgi, A.; Gouffon, P.; Grassi, V.; Grillo, A. F.; Grunfeld, C.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Gutierrez, J.; Hague, J. D.; Hamilton, J. C.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hauschildt, T.; Healy, M. D.; Hebbeker, T.; Hebrero, G.; Heck, D.; Hojvat, C.; Holmes, V. C.; Homola, P.; Hoerandel, J.; Horneffer, A.; Horvat, M.; Hrabovsky, M.; Huege, T.; Hussain, M.; Larlori, M.; Insolia, A.; Ionita, F.; Italiano, A.; Kaducak, M.; Kampert, K. H.; Karova, T.; Kegl, B.; Keilhauer, B.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapik, R.; Knapp, J.; Koanga, V. -H.; Krieger, A.; Kroemer, O.; Kuempel, D.; Kunka, N.; Kusenko, A.; La Rosa, G.; Lachaud, C.; Lago, B. L.; Lebrun, D.; LeBrun, P.; Lee, J.; de Oliveira, M. A. Leigui; Lopez, R.; Letessier-Selvon, A.; Leuthold, M.; Lhenry-Yvon, I.; Aguera, A. Lopez; Bahilo, J. Lozano; Garcia, R. Luna; Maccarone, M. C.; Macolino, C.; Maldera, S.; Mancarella, G.; Mancenido, M. E.; Mandatat, D.; Mantsch, P.; Mariazzi, A. G.; Maris, I. C.; Falcon, H. R. Marquez; Martello, D.; Martinez, J.; Bravo, O. Martinez; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; McCauley, T.; McEwen, M.; McNeil, R. R.; Medina, M. C.; Medina-Tanco, G.; Meli, A.; Melo, D.; Menichetti, E.; Menschikov, A.; Meurer, Chr.; Meyhandan, R.; Micheletti, M. I.; Miele, G.; Miller, W.; Mollerach, S.; Monasor, M.; Ragaigne, D. Monnier; Montanet, F.; Morales, B.; Morello, C.; Moreno, J. C.; Morris, C.; Mostafa, M.; Muller, M. A.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Newman-Holmes, C.; Newton, D.; Nhung, P. T.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nozka, L.; Oehlschlaeger, J.; Ohnuki, T.; Olinto, A.; Olmos-Gilbaja, V. M.; Ortiz, M.; Ortolani, F.; Ostapchenko, S.; Otero, L.; Pacheco, N.; Selmi-Dei, D. Pakk; Palatka, M.; Pallotta, J.; Parente, G.; Parizot, E.; Parlati, S.; Pastor, S.; Patel, M.; Paul, T.; Pavlidou, V.; Payet, K.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petrera, S.; Petrinca, P.; Petrov, Y.; Pichel, A.; Piegaia, R.; Pierog, T.; Pimenta, M.; Pinto, T.; Pirronello, V.; Pisanti, O.; Platino, M.; Pochon, J.; Privitera, P.; Prouza, M.; Quel, E. J.; Rautenberg, J.; Redondo, A.; Reucroft, S.; Revenu, B.; Rezende, F. A. S.; Ridky, J.; Riggi, S.; Risse, M.; Riviere, C.; Rizi, V.; Roberts, M.; Robledo, C.; Rodriguez, G.; Martino, J. Rodriguez; Rojo, J. Rodriguez; Rodriguez-Cabo, I.; Rodriguez-Frias, M. D.; Ros, G.; Rosado, J.; Roth, M.; Rouille-d'Orfeuil, B.; Roulet, E.; Roverok, A. C.; Salamida, F.; Salazar, H.; Salina, G.; Sanchez, F.; Santander, M.; Santo, C. E.; Santos, E. M.; Sarazin, F.; Sarkar, S.; Sato, R.; Scherini, V.; Schieler, H.; Schmidt, A.; Schmidt, F.; Schmidt, T.; Scholten, O.; Schovanek, P.; Schuessler, F.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Semikoz, D.; Settimo, M.; Shellard, R. C.; Sidelnik, I.; Siffert, B. B.; Sigl, G.; De Grande, N. Smetniansky; Smialkowski, A.; Smida, R.; Smith, A. G. K.; Smith, B. E.; Snow, G. R.; Sokolsky, P.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Strazzeri, E.; Stutz, A.; Suarez, F.; Suomijarvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Takahashi, J.; Tamashiro, A.; Tamburro, A.; Tascau, O.; Tcaciuc, R.; Thao, N. T.; Thomas, D.; Ticona, R.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Peixoto, C. J. Todero; Tome, B.; Tonachini, A.; Torres, I.; Travnicek, P.; Tripathi, A.; Tristram, G.; Tscherniakhovski, D.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Galicia, J. F. Valdes; Valino, I.; Valore, L.; van den Berg, A. M.; van Elewyck, V.; Vazquez, R. A.; Veberic, D.; Veiga, A.; Velarde, A.; Venters, T.; Verzi, V.; Videla, M.; Villasenor, L.; Vorobiov, S.; Voyvodic, L.; Wahlberg, H.; Wainberg, O.; Warner, D.; Watson, A. A.; Westerhoff, S.; Wieczorek, G.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Wileman, C.; Winnick, M. G.; Wu, H.; Wundheiler, B.; Yamamoto, T.; Younk, P.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zech, A.; Zepeda, A.; Ziolkowski, M.

    Data collected by the Pierre Auger Observatory provide evidence for anisotropy in the arrival directions of the cosmic rays with the highest-energies, which are correlated with the positions of relatively nearby active galactic nuclei (AGN) [Pierre Auger Collaboration, Science 318 (2007) 938]. The

  15. Observations of the highest energy gamma-rays from gamma-ray bursts

    International Nuclear Information System (INIS)

    Dingus, Brenda L.

    2001-01-01

    EGRET has extended the highest energy observations of gamma-ray bursts to GeV gamma rays. Such high energies imply the fireball that is radiating the gamma-rays has a bulk Lorentz factor of several hundred. However, EGRET only detected a few gamma-ray bursts. GLAST will likely detect several hundred bursts and may extend the maximum energy to a few 100 GeV. Meanwhile new ground based detectors with sensitivity to gamma-ray bursts are beginning operation, and one recently reported evidence for TeV emission from a burst

  16. Approach of the estimation for the highest energy of the gamma rays

    International Nuclear Information System (INIS)

    Dumitrescu, Gheorghe

    2004-01-01

    In the last decade there was under debate the issue concerning the composition of the ultra high energy cosmic rays and some authors suggested that the light composition seems to be a relating issue. There was another debate concerning the limit of the energy of gamma rays. The bottom-up approaches suggest a limit at 10 15 eV. Some top-down approaches rise this limit at about 10 20 eV or above. The present paper provides an approach to estimate the limit of the energy of gamma rays using the recent paper of Claus W. Turtur. (author)

  17. Correlation of the highest-energy cosmic rays with nearby extragalactic objects

    NARCIS (Netherlands)

    Pierre Auger Collaboration, [No Value; Abraham, J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez, C.; Alvarez-Muñiz, J.; Ambrosio, M.; Anchordoqui, L.; Andringa, S.; Anzalone, A.; Aramo, C.; Argirò, S.; Arisaka, K.; Armengaud, E.; Arneodo, F.; Arqueros, F.; Asch, T.; Asorey, H.; Assis, P.; Atulugama, B. S.; Aublin, J.; Ave, M.; Avila, G.; Bäcker, T.; Badagnani, D.; Barbosa, A. F.; Barnhill, D.; Barroso, S. L. C.; Bauleo, P.; Beatty, J.; Beau, T.; Becker, B. R.; Becker, K. H.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bergmann, T.; Bernardini, P.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanch-Bigas, O.; Blanco, F.; Blasi, P.; Bleve, C.; Blümer, H.; Bohácová, M.; Bonifazi, C.; Bonino, R.; Boratav, M.; Brack, J.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Busca, N. G.; Caballero-Mora, K. S.; Cai, B.; Camin, D. V.; Caruso, R.; Carvalho, W.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazón-Boado, L.; Cester, R.; Chauvin, J.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chye, J.; Clark, P. D. J.; Clay, R. W.; Colombo, E.; Conceição, R.; Connolly, B.; Contreras, F.; Coppens, J.; Cordier, A.; Cotti, U.; Coutu, S.; Covault, C. E.; Creusot, A.; Cronin, J.; Dagoret-Campagne, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Donato, C.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; del Peral, L.; Deligny, O.; Della Selva, A.; Delle Fratte, C.; Dembinski, H.; Di Giulio, C.; Diaz, J. C.; Dobrigkeit, C.; D'Olivo, J. C.; Dornic, D.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; DuVernois, M. A.; Engel, R.; Epele, L.; Erdmann, M.; Escobar, C. O.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Fernández, A.; Ferrer, F.; Ferry, S.; Fick, B.; Filevich, A.; Filipcic, A.; Fleck, I.; Fonte, R.; Fracchiolla, C. E.; Fulgione, W.; García, B.; García Gámez, D.; Garcia-Pinto, D.; Garrido, X.; Geenen, H.; Gelmini, G.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Herrero, R.; Gonçalves, P.; Gonçalves do Amaral, M.; Gonzalez, D.; Gonzalez, J. G.; González, M.; Góra, D.; Gorgi, A.; Gouffon, P.; Grassi, V.; Grillo, A.; Grunfeld, C.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Gutiérrez, J.; Hague, J. D.; Hamilton, J. C.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hauschildt, T.; Healy, M. D.; Hebbeker, T.; Heck, D.; Hojvat, C.; Holmes, V. C.; Homola, P.; Hörandel, J.; Horneffer, A.; Horvat, M.; Hrabovsky, M.; Huege, T.; Iarlori, M.; Insolia, A.; Ionita, F.; Italiano, A.; Kaducak, M.; Kampert, K. H.; Keilhauer, B.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapik, R.; Knapp, J.; Koang, D.-H.; Kopmann, A.; Krieger, A.; Krömer, O.; Kümpel, D.; Kunka, N.; Kusenko, A.; La Rosa, G.; Lachaud, C.; Lago, B. L.; Lebrun, D.; Le Brun, P.; Lee, J.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Leuthold, M.; Lhenry-Yvon, I.; López, R.; Lopez Agüera, A.; Lozano Bahilo, J.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Malek, M.; Mancarella, G.; Manceñido, M. E.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Maris, I. C.; Martello, D.; Martínez, J.; Martínez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; McCauley, T.; McEwen, M.; McNeil, R. R.; Medina, M. C.; Medina-Tanco, G.; Meli, A.; Melo, D.; Menichetti, E.; Menschikov, A.; Meurer, Chr.; Meyhandan, R.; Micheletti, M. I.; Miele, G.; Miller, W.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Morris, C.; Mostafá, M.; Muller, M. A.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Nellen, L.; Newman-Holmes, C.; Newton, D.; Nguyen Thi, T.; Nierstenhöfer, N.; Nitz, D.; Nosek, D.; Nozka, L.; Oehlschläger, J.; Ohnuki, T.; Olinto, A.; Olmos-Gilbaja, V. M.; Ortiz, M.; Ostapchenko, S.; Otero, L.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Parente, G.; Parizot, E.; Parlati, S.; Pastor, S.; Patel, M.; Paul, T.; Pavlidou, V.; Payet, K.; Pech, M.; Pçkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petrera, S.; Petrinca, P.; Petrov, Y.; Ngoc, DiepPham; Ngoc, DongPham; Pham Thi, T. N.; Pichel, A.; Piegaia, R.; Pierog, T.; Pimenta, M.; Pinto, T.; Pirronello, V.; Pisanti, O.; Platino, M.; Pochon, J.; Porter, T. A.; Privitera, P.; Prouza, M.; Quel, E. J.; Rautenberg, J.; Reucroft, S.; Revenu, B.; Rezende, F. A. S.; Rídky, J.; Riggi, S.; Risse, M.; Rivière, C.; Rizi, V.; Roberts, M.; Robledo, C.; Rodriguez, G.; Rodríguez Frías, D.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Cabo, I.; Ros, G.; Rosado, J.; Roth, M.; Rouillé-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Salamida, F.; Salazar, H.; Salina, G.; Sánchez, F.; Santander, M.; Santo, C. E.; Santos, E. M.; Sarazin, F.; Sarkar, S.; Sato, R.; Scherini, V.; Schieler, H.; Schmidt, F.; Schmidt, T.; Scholten, O.; Schovánek, P.; Schüssler, F.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Semikoz, D.; Settimo, M.; Shellard, R. C.; Sidelnik, I.; Siffert, B. B.; Sigl, G.; Smetniansky De Grande, N.; Smialkowski, A.; Smída, R.; Smith, A. G. K.; Smith, B. E.; Snow, G. R.; Sokolsky, P.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Strazzeri, E.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Takahashi, J.; Tamashiro, A.; Tamburro, A.; Tascau, O.; Tcaciuc, R.; Thomas, D.; Ticona, R.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Tomé, B.; Tonachini, A.; Torresi, D.; Travnicek, P.; Tripathi, A.; Tristram, G.; Tscherniakhovski, D.; Tueros, M.; Tunnicliffe, V.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van den Berg, A. M.; van Elewyck, V.; Vázquez, R. A.; Veberic, D.; Veiga, A.; Velarde, A.; Venters, T.; Verzi, V.; Videla, M.; Villaseñor, L.; Vorobiov, S.; Voyvodic, L.; Wahlberg, H.; Wainberg, O.; Waldenmaier, T.; Walker, P.; Warner, D.; Watson, A. A.; Westerhoff, S.; Wieczorek, G.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Wileman, C.; Winnick, M. G.; Wu, H.; Wundheiler, B.; Xu, J.; Yamamoto, T.; Younk, P.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zech, A.; Zepeda, A.; Ziolkowski, M.

    2007-01-01

    Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrated a correlation between the arrival directions of cosmic rays with energy above 6 × 1019 electron volts and the positions of active galactic nuclei (AGN) lying within ~75 megaparsecs. We rejected the

  18. THE HIGHEST-ENERGY COSMIC RAYS CANNOT BE DOMINANTLY PROTONS FROM STEADY SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Ke [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Kotera, Kumiko [Sorbonne Universités, UPMC Univ. Paris 6 et CNRS, UMR 7095, Institut d’Astrophysique de Paris, 98 bis bd Arago, F-75014 Paris (France)

    2016-11-20

    The bulk of observed ultrahigh-energy cosmic rays could be light or heavier elements and originate from an either steady or transient population of sources. This leaves us with four general categories of sources. Energetic requirements set a lower limit on single-source luminosities, while the distribution of particle arrival directions in the sky sets a lower limit on the source number density. The latter constraint depends on the angular smearing in the skymap due to the magnetic deflections of the charged particles during their propagation from the source to the Earth. We contrast these limits with the luminosity functions from surveys of existing luminous steady objects in the nearby universe and strongly constrain one of the four categories of source models, namely, steady proton sources. The possibility that cosmic rays with energy >8 × 10{sup 19} eV are dominantly pure protons coming from steady sources is excluded at 95% confidence level, under the safe assumption that protons experience less than 30° magnetic deflection on flight.

  19. VESUVIO. A project to provide enhanced neutron scattering capabilities at the highest energy transfers

    International Nuclear Information System (INIS)

    Tomkinson, J.; Bowden, Z.A.; Mayers, J.; Norris, J.; Rhodes, N.J.; Colognesi, D.; Fielding, A.L.; Praitano, M.

    1999-01-01

    Complete text of publication follows. The VESUVIO project is financed within the TMR-Access to Large Scale Facility (RTD project) of the European Community. It will provide unique prototype instrumentation at the ISIS neutron source which will build on the success and experience of the eVS spectrometer in measuring single particle dynamics of a wide range of condensed matter systems. The instrumentation is designed for high momentum (20A -1 -1 ) and energy (ℎω>1eV) transfer inelastic neutron scattering studies of microscopic dynamical properties such as, single particle kinetic energies and momentum distributions. Specific objectives are: a) to optimize and construct a high efficiency, high area detector, 6 Li doped scintillator glasses are being tested; b) to construct a sample tank capable of operating with either a cold, or room temperature, filter analyzers; c) to develop new electronics and data acquisition to handle the high count-rates which will be generated in the azimuthal detectors. Some examples of applications performed during the first year of the project will be presented. (author)

  20. LHC project. Exploring the smallest world with the highest energy beam

    International Nuclear Information System (INIS)

    Kondo, Takahiko; Kobayashi, Tomio

    2007-01-01

    The LHC accelerator at CERN will be completed soon and the experiments are about to start, making it possible to explore the TeV energy region for the first time in human history. There exists a clear reason why the TeV region is especially important for experimental exploration. The Higgs particle, the last elusive element of the Standard Model, will be discovered with very high probability. In addition there are high chances to discover signs of new physics beyond the Standard Model such as SUSY particles. Dark matter may be discovered. As an introduction of the mini-special issue for LHC, its goals and history is briefly reviewed, followed by a description on LHC accelerator, four LHC experiments as well as the contributions by Japan. (author)

  1. Development of an Interferometric Phased Array Trigger for Balloon-Borne Detection of the Highest Energy Cosmic Particles

    Science.gov (United States)

    Vieregg, Abigail

    Through high energy neutrino astrophysics, we explore the structure and evolution of the universe in a unique way and learn about the physics inside of astrophysical sources that drives the acceleration of the highest energy particles. Neutrinos travel virtually unimpeded through the universe, making them unique messenger particles for cosmic sources and carrying information about very distant sources that would otherwise be unavailable. The highest energy neutrinos (E>10^{18} eV), created as a by-product of the interaction of the highest energy cosmic rays with the cosmic microwave background, are an important tool for determining the origin of the highest energy cosmic rays and still await discovery. Balloon-borne and ground-based experiments are poised to discover these ultra-high energy (UHE) cosmogenic neutrinos by looking for radio emission from two different types of neutrino interactions: particle cascades induced by neutrinos in glacial ice, and extensive air showers in the atmosphere induced by the charged-particle by-product of tau neutrinos interacting in the earth. These impulsive radio detectors are also sensitive to radio emission from extensive air showers induced directly by UHE cosmic rays. Balloon-borne experiments are especially well-suited for discovering the highest energy neutrinos, and are the only way to probe the high energy cutoff of the sources themselves to reveal the astrophysics that drives the central engines inside the most energetic accelerators in the universe. Balloon platforms offer the chance to monitor extremely large volumes of ice and atmosphere, but with a higher energy threshold compared to ground-based observatories, since the neutrino interaction happens farther from the detector. This tradeoff means that the sensitivity of balloon-borne experiments, such as the Antarctic Impulsive Transient Antenna (ANITA) or the ExaVolt Antenna, is optimized for discovery of the highest energy neutrinos. We are developing an

  2. High energy charged particle registration in CR-39 polycarbonated detector

    International Nuclear Information System (INIS)

    Abdel-Wahab, M.S.; El Enany, N.; El Fiki, S.; Eissa, H.M.; El-Adl, E.H.; El-Feky, M.A.

    1991-01-01

    Track etch rate characteristics of CR-39 plastic detector exposed to 28 Si ions of 670 MeV energy have been investigated. Experimental results were obtained in terms of frequency distribution of the track diameter, track density and bulk etching rate. A dependence of the mean track diameter on energy was found. The application of the radiation effect of heavy ions on CR-39 in the field of radiation detection and dosimetry are discussed. Results indicated that it is possible to produce etchable tracks of 28 Si in this energy range in CR-39. We also report the etching characteristics of these tracks in the CR-39 detector. (orig.) [de

  3. Analysis of the highest transverse energy events seen in the UAl detector at the Spp-barS collider

    International Nuclear Information System (INIS)

    1987-06-01

    The first full solid angle analysis is presented of large transverse energy events in pp-bar collisions at the CERN collider. Events with transverse energies in excess of 200 GeV at √s = 630 GeV are studied for any non-standard physics and quantitatively compared with expectations from perturbative QCD Monte Carlo models. A corrected differential cross section is presented. A detailed examination is made of jet profiles, event jet multiplicities and the fraction of the transverse energy carried by the two jets with the highest transverse jet energies. There is good agreement with standard theory for events with transverse energies up to the largest observed values (approx. √s/2) and the analysis shows no evidence for any non-QCD mechanism to account for the event characteristics. (author)

  4. Analysis of the highest transverse energy events seen in the UA1 detector at the Spanti pS collider

    International Nuclear Information System (INIS)

    Albajar, C.; Bezaguet, A.; Cennini, P.

    1987-01-01

    This is the first full solid angle analysis of large transverse energy events in panti p collisions at the CERN collider. Events with transverse energies in excess of 200 GeV at √s=630 GeV are studied for any non-standard physics and quantitatively compared with expectations from perturbative QCD Monte Carlo models. A corrected differential cross section is presented. A detailed examination is made of jet profiles, event jet multiplicities and the fraction of the transverse energy carried by the two jets with the highest transverse jet energies. There is good agreement with standard theory for events with transverse energies up to the largest observed values (≅ √s/2) and the analysis shows no evidence for any non-QCD mechanism to account for the event characteristics. (orig.)

  5. Ground-state energies and highest occupied eigenvalues of atoms in exchange-only density-functional theory

    Science.gov (United States)

    Li, Yan; Harbola, Manoj K.; Krieger, J. B.; Sahni, Viraht

    1989-11-01

    The exchange-correlation potential of the Kohn-Sham density-functional theory has recently been interpreted as the work required to move an electron against the electric field of its Fermi-Coulomb hole charge distribution. In this paper we present self-consistent results for ground-state total energies and highest occupied eigenvalues of closed subshell atoms as obtained by this formalism in the exchange-only approximation. The total energies, which are an upper bound, lie within 50 ppm of Hartree-Fock theory for atoms heavier than Be. The highest occupied eigenvalues, as a consequence of this interpretation, approximate well the experimental ionization potentials. In addition, the self-consistently calculated exchange potentials are very close to those of Talman and co-workers [J. D. Talman and W. F. Shadwick, Phys. Rev. A 14, 36 (1976); K. Aashamar, T. M. Luke, and J. D. Talman, At. Data Nucl. Data Tables 22, 443 (1978)].

  6. Communication: The highest frequency hydrogen bond vibration and an experimental value for the dissociation energy of formic acid dimer

    DEFF Research Database (Denmark)

    Kollipost, F.; Larsen, René Wugt; Domanskaya, A.V.

    2012-01-01

    The highest frequency hydrogen bond fundamental of formic acid dimer, ν24 (Bu), is experimentally located at 264 cm−1. FTIR spectra of this in-plane bending mode of (HCOOH)2 and band centers of its symmetric D isotopologues (isotopomers) recorded in a supersonic slit jet expansion are presented...... thermodynamics treatment of the dimerization process up to room temperature. We obtain D0 = 59.5(5) kJ/mol as the best experimental estimate for the dimer dissociation energy at 0 K. Further improvements have to wait for a more consistent determination of the room temperature equilibrium constant....

  7. Molecular dynamics study on threshold displacement energies in Fe-Cr alloys

    Science.gov (United States)

    Fu, Jiawei; Ding, Wenyi; Zheng, Mingjie; Mao, Xiaodong

    2018-03-01

    The threshold displacement energies (Ed) of Fe and Cr atoms in Fe-Cr alloys with Cr contents ranging from 0% to 21% have been obtained with molecular dynamics (MD) method. The values of Ed have been calculated along the three high-symmetry crystallographic directions [0 0 1], [0 1 1] and [1 1 1], a slightly 2° tilt from these directions, and a high-index crystallographic directions [1 3 5]. The results showed that [0 1 1] crystallographic direction had the highest Ed among the three high-symmetry directions in each Cr content alloy. Fe-9Cr had higher weighted average Ed than the other Cr content alloys for both Fe and Cr PKA due to its statistically high Ed along the [0 1 1] crystallographic direction up to 44.3 eV. And the statistical analysis on the primary damage configuration demonstrated that 〈1 1 0〉Fe-Fe dumbbells were the dominant defect structures after relaxation. These data can enrich the database of Ed in Fe-Cr alloys and have potential applications in guiding the optimization design of radiation-resistant RAFM steels.

  8. Range energy for heavy ions in CR-39

    International Nuclear Information System (INIS)

    Gil, L.R.; Marques, A.

    1987-01-01

    Range-energy relations in CR-39, for ions from He to Ar, are obtained after their effective nuclear charge. Comparison with earlier calculations and numerical results in the energy range 0,1 to 200 Mev/ Nucleon are also given. (M.W.O.)

  9. Solving The Longstanding Problem Of Low-Energy Nuclear Reactions At the Highest Microscopic Level - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Quaglioni, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-09-22

    A 2011 DOE-NP Early Career Award (ECA) under Field Work Proposal (FWP) SCW1158 supported the project “Solving the Long-Standing Problem of Low-Energy Nuclear Reactions at the Highest Microscopic Level” in the five-year period from June 15, 2011 to June 14, 2016. This project, led by PI S. Quaglioni, aimed at developing a comprehensive and computationally efficient framework to arrive at a unified description of structural properties and reactions of light nuclei in terms of constituent protons and neutrons interacting through nucleon-nucleon (NN) and three-nucleon (3N) forces. Specifically, the project had three main goals: 1) arriving at the accurate predictions for fusion reactions that power stars and Earth-based fusion facilities; 2) realizing a comprehensive description of clustering and continuum effects in exotic nuclei, including light Borromean systems; and 3) achieving fundamental understanding of the role of the 3N force in nuclear reactions and nuclei at the drip line.

  10. INVESTIGATION OF NONAXISYMMETRIC STRESS STATE FOR QUASI-STATIC THERMAL POWER LOADING UNDER CONDITIONS OF HIGHEST-ENERGY PARTICLE IRRADIATION

    Directory of Open Access Journals (Sweden)

    A. V. Chigarev

    2013-01-01

    Full Text Available The paper contains a virtual modeling 2D(r, θ for deformation of singly-connected cylindrical solid under conditions of thermo-irradiation impact. Influence of a circumferential distortion on nonaxisymmetric strain-stress state for various values of temperature amplitudes has been investigated in the paper. A solid cylinder  with internal heat sources has been considered as a model body. Properties of the model body correspond to cermet fuel (40 % UO2 + 60 % Cr

  11. Energy response study of modified CR-39 neutron personnel dosimeter

    International Nuclear Information System (INIS)

    Sathian, Deepa; Bakshi, A.K.; Datta, D.; Nair, Sreejith S.; Sathian, V.; Mishra, Jitendra; Sen, Meghnath

    2018-01-01

    Personnel neutron dosimetry is an integral part of radiation protection. No single dosimeter provides the satisfactory energy response, sensitivity, angular dependence characteristics and accuracy necessary to meet the requirement of an ideal personnel neutron dosimeter. The response of a personnel neutron dosimeter is critically dependent upon the energy distribution of the neutron field. CR-39 personnel neutron dosimeters were typically calibrated in the standard neutron field of 252 Cf and 241 Am-Be in our laboratory, although actual neutron fields may vary from the calibration neutron spectrum. Recently the badge cassette of the personnel neutron dosimeter was changed due to frequent damage of the PVC badge used earlier. This paper discusses energy response of CR-39 solid state nuclear track detector loaded in this modified badge cassette as per latest ISO recommendation

  12. On the possibility of highest energy cosmic rays bursts and their correlation with gamma rays bursts e.g. March 5th, 1979 event

    International Nuclear Information System (INIS)

    Drukier, K.

    1982-01-01

    The avalanche production of magnetic monopoles is possible in neutron stars. Big part of the magnetic field energy can be used to accelerate a pulse of 10 30 monopoles to the energy E > approximately 10 17 eV. Thus the neutron stars may be ''point'' sources of bursts of highest energy Cosmic Rays. The emission of brehmsstrahlung photons by these highly relativistic monopoles would be seen as X and gamma bursts. This ''exotic'' model for March 5th, 1979 event, predicts that it has been followed by burst of highest energy Cosmic Rays coming from the direction of LMC supernovae remanent N49

  13. Design optimization of radial flux permanent magnetwind generator for highest annual energy input and lower magnet volumes

    Energy Technology Data Exchange (ETDEWEB)

    Faiz, J.; Rajabi-Sebdani, M.; Ebrahimi, B. M. (Univ. of Tehran, Tehran (Iran)); Khan, M. A. (Univ. of Cape Town, Cape Town (South Africa))

    2008-07-01

    This paper presents a multi-objective optimization method to maximize annual energy input (AEI) and minimize permanent magnet (PM) volume in use. For this purpose, the analytical model of the machine is utilized. Effects of generator specifications on the annual energy input and PM volume are then investigated. Permanent magnet synchronous generator (PMSG) parameters and dimensions are then optimized using genetic algorithm incorporated with an appropriate objective function. The results show an enhancement in PMSG performance. Finally 2D time stepping finite element method (2D TSFE) is used to verify the analytical results. Comparison of the results validates the optimization method

  14. Searches for anisotropies in the arrival directions of the highest energy cosmic rays detected by the Pierre Auger Observatory

    Czech Academy of Sciences Publication Activity Database

    Aab, A.; Abreu, P.; Aglietta, M.; Boháčová, Martina; Chudoba, Jiří; Ebr, Jan; Mandát, Dušan; Nečesal, Petr; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovánek, Petr; Trávníček, Petr; Vícha, Jakub

    2015-01-01

    Roč. 804, č. 1 (2015), s. 15 ISSN 0004-637X R&D Projects: GA MŠk(CZ) LG13007; GA MŠk(CZ) 7AMB14AR005; GA ČR(CZ) GA14-17501S Institutional support: RVO:68378271 Keywords : acceleration of particles * astroparticle physics Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 5.909, year: 2015

  15. Partial decay energy of 51Cr from inner bremsstrahlung spectrum

    International Nuclear Information System (INIS)

    Sanjeeviah, H.; Sanjeevaiah, B.

    1980-01-01

    The inner bremsstrahlung spectrum accompanying orbital electron capture decay of 51 Cr to the first excited state in 51 V was measured in coincidence with 320 keV gamma rays. From the Jauch plot of the spectrum the partial decay energy was deduced to be 433 +- 18 keV in good agreement with the previously measured value and the accepted mass difference. The overall shape factor of the inner bremsstrahlung spectrum was found to be a constant X(1.1 +- 0.1). (author)

  16. Nanostructured Fe-Cr Alloys for Advanced Nuclear Energy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Scattergood, Ronald O. [North Carolina State Univ., Raleigh, NC (United States)

    2016-04-26

    We have completed research on the grain-size stabilization of model nanostructured Fe14Cr base alloys at high temperatures by the addition of non-equilibrium solutes. Fe14Cr base alloys are representative for nuclear reactor applications. The neutron flux in a nuclear reactor will generate He atoms that coalesce to form He bubbles. These can lead to premature failure of the reactor components, limiting their lifetime and increasing the cost and capacity for power generation. In order to mitigate such failures, Fe14Cr base alloys have been processed to contain very small nano-size oxide particles (less than 10 nm in size) that trap He atoms and reduce bubble formation. Theoretical and experimental results indicate that the grain boundaries can also be very effective traps for He atoms and bubble formation. An optimum grain size will be less than 100 nm, ie., nanocrystalline alloys must be used. Powder metallurgy methods based on high-energy ball milling can produce Fe-Cr base nanocrystalline alloys that are suitable for nuclear energy applications. The problem with nanocrystalline alloys is that excess grain-boundary energy will cause grains to grow at higher temperatures and their propensity for He trapping will be lost. The nano-size oxide particles in current generation nuclear alloys provide some grain size stabilization by reducing grain-boundary mobility (Zener pinning – a kinetic effect). However the current mitigation strategy minimizing bubble formation is based primarily on He trapping by nano-size oxide particles. An alternate approach to nanoscale grain size stabilization has been proposed. This is based on the addition of small amounts of atoms that are large compared to the base alloy. At higher temperatures these will diffuse to the grain boundaries and will produce an equilibrium state for the grain size at higher temperatures (thermodynamic stabilization – an equilibrium effect). This would be preferred compared to a kinetic effect, which is not

  17. Surface free energy of CrN x films deposited using closed field unbalanced magnetron sputtering

    International Nuclear Information System (INIS)

    Sun, C.-C.; Lee, S.-C.; Dai, S.-B.; Fu, Y.-S.; Wang, Y.-C.; Lee, Y.-H.

    2006-01-01

    CrN x thin films have attracted much attention for semiconductor IC packaging molding dies and forming tools due to their excellent hardness, thermal stability and non-sticking properties (low surface free energy). However, few data has been published on the surface free energy (SFE) of CrN x films at temperatures in the range 20-170 deg. C. In this study CrN x thin films with CrN, Cr(N), Cr 2 N (and mixture of these phases) were prepared using closed field unbalanced magnetron sputtering at a wide range of Cr +2 emission intensity. The contact angles of water, di-iodomethane and ethylene glycol on the coated surfaces were measured at temperatures in the range 20-170 deg. C using a Dataphysics OCA-20 contact angle analyzer. The surface free energy of the CrN x films and their components (e.g., dispersion, polar) were calculated using the Owens-Wendt geometric mean approach. The influences of CrN x film surface roughness and microstructure on the surface free energy were investigated by atomic force microscopy (AFM) and X-ray diffraction (XRD), respectively. The experimental results showed that the lowest total SFE was obtained corresponding to CrN at temperature in 20 deg. C. This is lower than that of Cr(N), Cr 2 N (and mixture of these phases). The total SFE, dispersive SFE and polar SFE of CrN x films decreased with increasing surface temperature. The film roughness has an obvious effect on the SFE and there is tendency for the SFE to increase with increasing film surface roughness

  18. Spin flip at unelastic scattering of protons with energy near 6 NeV o 50Cr and 52Cr nuclei

    International Nuclear Information System (INIS)

    Andronov, Yu.F.; Chubinskij, O.V.; Vinogradov, L.I.; Ehl'-Ashri, F.I.; Gustova, L.V.

    1978-01-01

    Angular S(Q) and energy S(E) dependences spin flip probability S were studied in inelastic scattering of protons with excitation of the 2 1 + states of 50 Cr (Q=-0.782 MeV) and 52 Cr (Q=-1.434 MeV) energy range from 5.6 to 5.95 MeV. In particular, it is elucidated how strongly the behaviour of the spin flip probability depends upon the energy and angle of scattering at Esub(p) approximately 6 MeV for 50 Cr and 52 Cr. Thereby some additional information on specific features of the mechanism of inelastic sccattering by th nuclei is obtained. Measurements were carried out simultaneously in two proton detection channels at scattering angles differing by 30 deg. For targets use was made of self-sustaining enriched foils (87% 50 Cr and 99% 52 Cr). The angular and energy dependences of the spin flip probabilities for 50 Cr and 52 Cr are shown to be rather different: for 52 Cr has a relatively slight energy dependence in the range of a resonance observed in the excitation function; for 50 Cr the behaviour of S(E) undergoes sharp changes. The experimetnal values of S(Q) for sup(50, 52)Cr differ rather strongly from the calculations made on the statistical model and depend considerably upon the scattering angle

  19. Determination of cosmic ray (CR) ionization path and iono/atmospheric cut-off energy from CR intervals III, IV and V in the planetary environments

    International Nuclear Information System (INIS)

    Velinov, P.

    2001-01-01

    In this paper are determined the ionization path and cut-off energies of the cosmic ray (CR) nuclei in relation to the general interaction model 'CR - ionosphere-middle atmosphere'. Here the ionization path and the iono/atmospheric cut-off energies of the galactic CR, solar CR and anomalous CR are separately considered in each energetic range, without taking into account the particle transfer from one range in another. This more general approach will be the object of a further paper

  20. Immediate remediation of heavy metal (Cr(VI)) contaminated soil by high energy electron beam irradiation

    International Nuclear Information System (INIS)

    Zhang, Jing; Zhang, Guilong; Cai, Dongqing; Wu, Zhengyan

    2015-01-01

    Highlights: • An immediate remediation method for Cr(VI) contaminated soil (CCS) was developed. • High energy electron beam (HEEB) irradiation could reduce Cr(VI) in CCS to Cr(III). • This effect was attributed to electrons, hydrated electrons, and reductive radicals. • This remediation method was effective, environmentally friendly, and low-cost. - Abstract: This work developed an immediate and high-performance remediation method for Cr(VI) contaminated soil (CCS) using high energy electron beam (HEEB) irradiation. The result indicated that, compared with γ-ray irradiation, HEEB irradiation displayed a significant reduction efficiency on Cr(VI) in CCS to Cr(III) with substantially lower toxicity, which was mainly attributed to the reduction effects of electrons, hydrated electrons, and reductive radicals generated in the irradiation process of HEEB. This work could provide a one-step and effective method for the remediation of heavy metal contaminated soil (HMCS)

  1. Immediate remediation of heavy metal (Cr(VI)) contaminated soil by high energy electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jing; Zhang, Guilong [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei 230031 (China); Bioenergy Forest Research Center of State Forestry Administration, Hefei 230031 (China); Cai, Dongqing, E-mail: dqcai@ipp.ac.cn [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei 230031 (China); Bioenergy Forest Research Center of State Forestry Administration, Hefei 230031 (China); Wu, Zhengyan, E-mail: zywu@ipp.ac.cn [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei 230031 (China); Bioenergy Forest Research Center of State Forestry Administration, Hefei 230031 (China)

    2015-03-21

    Highlights: • An immediate remediation method for Cr(VI) contaminated soil (CCS) was developed. • High energy electron beam (HEEB) irradiation could reduce Cr(VI) in CCS to Cr(III). • This effect was attributed to electrons, hydrated electrons, and reductive radicals. • This remediation method was effective, environmentally friendly, and low-cost. - Abstract: This work developed an immediate and high-performance remediation method for Cr(VI) contaminated soil (CCS) using high energy electron beam (HEEB) irradiation. The result indicated that, compared with γ-ray irradiation, HEEB irradiation displayed a significant reduction efficiency on Cr(VI) in CCS to Cr(III) with substantially lower toxicity, which was mainly attributed to the reduction effects of electrons, hydrated electrons, and reductive radicals generated in the irradiation process of HEEB. This work could provide a one-step and effective method for the remediation of heavy metal contaminated soil (HMCS)

  2. World's largest air shower array now on track of super-high-energy cosmic-rays Pierre Auger Observatory seeks source of highest-energy extraterrestrial particles

    CERN Multimedia

    2003-01-01

    "With the completion of its hundredth surface detector, the Pierre Auger Observatory, under construction in Argentina, this week became the largest cosmic-ray air shower array in the world. Managed by scientists at the Department of Energy's Fermi National Accelerator Laboratory, the Pierre Auger project so far encompasses a 70-square-mile array of detectors that are tracking the most violent-and perhaps most puzzling- processes in the entire universe" (1 page).

  3. Track etch parameters and annealing kinetics assessment of protons of low energy in CR-39 detector

    International Nuclear Information System (INIS)

    Jain, R.K.; Kumar, Ashok; Singh, B.K.

    2012-01-01

    Highlights: ► We calibrate CR-39 detector with very low energy protons. ► We establish linear relationship between track diameter and time/energy up to 200 keV. ► We determine activation energy of annealing using different models. ► We justify concept of single annealing activation energy in CR-39. - Abstract: In this paper threshold of the registration sensitivity of very low energy proton in CR-39 is investigated. Irradiation of CR-39 (poly-allyl-diglycol carbonate) was carried out with very low energy mono energetic protons of 20–60 keV from a mini proton accelerator. Nearly 10 4 /cm 2 fluence of protons was used. The variation of track diameter with etching time as well as proton energy response curve was carefully calibrated. The bulk and track etch rates were measured by using proton track diameters. Bulk etch rate was also measured by the thickness of removed surface layer. The thermal annealing of proton track at temperatures ranging from 100 to 200 °C in CR-39 was studied by several models. Activation energy of annealed CR-39 detectors was calculated by slope of track etch rate and temperature plot. The data of proton tracks of 200, 250 and 300 keV from 400 kV Van-de-Graaff accelerator was also used and compared with the track diameters of different energies of proton.

  4. Highest priority in Pakistan.

    Science.gov (United States)

    Adil, E

    1968-01-01

    Responding to the challenge posed by its population problem, Pakistan's national leadership gave the highest priority to family planning in its socioeconomic development plan. In Pakistan, as elsewhere in the world, the first family planning effort originated in the private sector. The Family Planning Association of Pakistan made a tentative beginning in popularizing family planning in the country. Some clinics were opened and some publicity and education were undertaken to emphasize the need for family limitation. It was recognized soon that the government needed to assume the primarily responsibility if family planning efforts were to be successful. For the 1st plan period, 1955-60, about $10 million was allocated by the central government in the social welfare sector for voluntary family planning. The level of support continued on the same basis during the 2nd plan, 1960-65, but has been raised 4-fold in the 1965-70 scheme of family planning. Pakistan's Family Planning Association continues to play vital collaborative roles in designing and pretesting of prototype publicity material, involvement of voluntary social workers, and functional research in the clinical and public relations fields. The real breakthrough in the program came with the 3rd 5-year plan, 1965-70. High priority assigned to family planning is reflected by the total initial budget of Rs.284 million (about $60,000,000) for the 5-year period. Current policy is postulated on 6 basic assumptions: family planning efforts need to be public relations-oriented; operations should be conducted through autonomous bodies with decentralized authority at all tiers down to the grassroots level, for expeditious decision making; monetary incentives play an important role; interpersonal motivation in terms of life experience of the clientele through various contacts, coupled with mass media for publicity, can produce a sociological breakthrough; supplies and services in all related disciplines should be

  5. Highest Resolution Gaspra Mosaic

    Science.gov (United States)

    1992-01-01

    This picture of asteroid 951 Gaspra is a mosaic of two images taken by the Galileo spacecraft from a range of 5,300 kilometers (3,300 miles), some 10 minutes before closest approach on October 29, 1991. The Sun is shining from the right; phase angle is 50 degrees. The resolution, about 54 meters/pixel, is the highest for the Gaspra encounter and is about three times better than that in the view released in November 1991. Additional images of Gaspra remain stored on Galileo's tape recorder, awaiting playback in November. Gaspra is an irregular body with dimensions about 19 x 12 x 11 kilometers (12 x 7.5 x 7 miles). The portion illuminated in this view is about 18 kilometers (11 miles) from lower left to upper right. The north pole is located at upper left; Gaspra rotates counterclockwise every 7 hours. The large concavity on the lower right limb is about 6 kilometers (3.7 miles) across, the prominent crater on the terminator, center left, about 1.5 kilometers (1 mile). A striking feature of Gaspra's surface is the abundance of small craters. More than 600 craters, 100-500 meters (330-1650 feet) in diameter are visible here. The number of such small craters compared to larger ones is much greater for Gaspra than for previously studied bodies of comparable size such as the satellites of Mars. Gaspra's very irregular shape suggests that the asteroid was derived from a larger body by nearly catastrophic collisions. Consistent with such a history is the prominence of groove-like linear features, believed to be related to fractures. These linear depressions, 100-300 meters wide and tens of meters deep, are in two crossing groups with slightly different morphology, one group wider and more pitted than the other. Grooves had previously been seen only on Mars's moon Phobos, but were predicted for asteroids as well. Gaspra also shows a variety of enigmatic curved depressions and ridges in the terminator region at left. The Galileo project, whose primary mission is the

  6. Gaspra - Highest Resolution Mosaic

    Science.gov (United States)

    1992-01-01

    This picture of asteroid 951 Gaspra is a mosaic of two images taken by the Galileo spacecraft from a range of 5,300 kilometers (3,300 miles), some 10 minutes before closest approach on October 29, 1991. The Sun is shining from the right; phase angle is 50 degrees. The resolution, about 54 meters/pixel, is the highest for the Gaspra encounter and is about three times better than that in the view released in November 1991. Additional images of Gaspra remain stored on Galileo's tape recorder, awaiting playback in November. Gaspra is an irregular body with dimensions about 19 x 12 x 11 kilometers (12 x 7.5 x 7 miles). The portion illuminated in this view is about 18 kilometers (11 miles) from lower left to upper right. The north pole is located at upper left; Gaspra rotates counterclockwise every 7 hours. The large concavity on the lower right limb is about 6 kilometers (3.7 miles) across, the prominent crater on the terminator, center left, about 1.5 kilometers (1 mile). A striking feature of Gaspra's surface is the abundance of small craters. More than 600 craters, 100-500 meters (330-1650 feet) in diameter are visible here. The number of such small craters compared to larger ones is much greater for Gaspra than for previously studied bodies of comparable size such as the satellites of Mars. Gaspra's very irregular shape suggests that the asteroid was derived from a larger body by nearly catastrophic collisions. Consistent with such a history is the prominence of groove-like linear features, believed to be related to fractures. These linear depressions, 100-300 meters wide and tens of meters deep, are in two crossing groups with slightly different morphology, one group wider and more pitted than the other. Grooves had previously been seen only on Mars's moon Phobos, but were predicted for asteroids as well. Gaspra also shows a variety of enigmatic curved depressions and ridges in the terminator region at left. The Galileo project, whose primary mission is the

  7. The voltage optimization of a four-element lens used on a hemispherical spectrograph with virtual entry for highest energy resolution

    International Nuclear Information System (INIS)

    Sise, O.; Martínez, G.; Madesis, I.; Laoutaris, A.; Dimitriou, A.; Fernández-Martín, M.; Zouros, T.J.M.

    2016-01-01

    Highlights: • We investigate the voltage settings for the four-element injection lens of an HDA. • The two well-known approaches, BEM and FDM, in charged particle optics were used. • We tested optimal lens voltages from simulation on the actual experimental setup. • The measured FWHM were well modeled using realistic source parameters. • The results are helpful to experimenters. - Abstract: The methodology and results of a detailed four-element lens optimization analysis based on electron trajectory numerical simulations are presented for a hemispherical deflector analyzer (HDA), whose entry aperture size is determined by the injection lens itself and is therefore virtual. Trajectory calculations were performed using both the boundary-element method (BEM) and the finite-difference method (FDM) and results from these two different approaches were benchmarked against each other, to probe and confirm the accuracy of our results. Since the first and last electrode are held at fixed potentials, the two intermediate adjustable lens electrode voltages were varied over the entire available voltage space in a direct, systematic, brute-force approach, while minima in beam spot size on the 2-D position sensitive detector (PSD) at the exit of the HDA were investigated using a beam shaping approach. Lens voltages demonstrating improved energy resolution for the combined lens/HDA/PSD spectrograph system were sought with and without pre-retardation. The optimal voltages were then tested experimentally on the modeled HDA system using a hot-wire electron gun. The measured energy resolution was found to be in good overall agreement with our simulations, particularly at the highest resolution (∼0.05%) working conditions. These simulations also provide a detailed insight to the distinctive trajectory optics and positions of the first and second image planes, when the PSD has to be placed some distance away from the HDA exit plane, and is therefore not at the ideal optics

  8. The voltage optimization of a four-element lens used on a hemispherical spectrograph with virtual entry for highest energy resolution

    Energy Technology Data Exchange (ETDEWEB)

    Sise, O., E-mail: omersise@sdu.edu.tr [Department of Science Education, Faculty of Education, Suleyman Demirel University, 32260 Isparta (Turkey); Martínez, G. [Departamento de Física Aplicada III, Facultad de Física, UCM, 28040 Madrid (Spain); Madesis, I. [Department of Physics, University of Crete, P.O. Box 2208, GR, 71003 Heraklion (Greece); Tandem Accelerator Laboratory, INPP, NCSR Demokritos, GR, 15310 Ag Paraskevi (Greece); Laoutaris, A. [Tandem Accelerator Laboratory, INPP, NCSR Demokritos, GR, 15310 Ag Paraskevi (Greece); Department of Applied Physics, National Technical University of Athens, GR, 15780 Athens (Greece); Dimitriou, A. [Department of Physics, University of Crete, P.O. Box 2208, GR, 71003 Heraklion (Greece); Tandem Accelerator Laboratory, INPP, NCSR Demokritos, GR, 15310 Ag Paraskevi (Greece); Fernández-Martín, M. [Departamento de Física Aplicada III, Facultad de Física, UCM, 28040 Madrid (Spain); Zouros, T.J.M. [Department of Physics, University of Crete, P.O. Box 2208, GR, 71003 Heraklion (Greece); Tandem Accelerator Laboratory, INPP, NCSR Demokritos, GR, 15310 Ag Paraskevi (Greece)

    2016-08-15

    Highlights: • We investigate the voltage settings for the four-element injection lens of an HDA. • The two well-known approaches, BEM and FDM, in charged particle optics were used. • We tested optimal lens voltages from simulation on the actual experimental setup. • The measured FWHM were well modeled using realistic source parameters. • The results are helpful to experimenters. - Abstract: The methodology and results of a detailed four-element lens optimization analysis based on electron trajectory numerical simulations are presented for a hemispherical deflector analyzer (HDA), whose entry aperture size is determined by the injection lens itself and is therefore virtual. Trajectory calculations were performed using both the boundary-element method (BEM) and the finite-difference method (FDM) and results from these two different approaches were benchmarked against each other, to probe and confirm the accuracy of our results. Since the first and last electrode are held at fixed potentials, the two intermediate adjustable lens electrode voltages were varied over the entire available voltage space in a direct, systematic, brute-force approach, while minima in beam spot size on the 2-D position sensitive detector (PSD) at the exit of the HDA were investigated using a beam shaping approach. Lens voltages demonstrating improved energy resolution for the combined lens/HDA/PSD spectrograph system were sought with and without pre-retardation. The optimal voltages were then tested experimentally on the modeled HDA system using a hot-wire electron gun. The measured energy resolution was found to be in good overall agreement with our simulations, particularly at the highest resolution (∼0.05%) working conditions. These simulations also provide a detailed insight to the distinctive trajectory optics and positions of the first and second image planes, when the PSD has to be placed some distance away from the HDA exit plane, and is therefore not at the ideal optics

  9. Up to the highest peak!

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    In the early hours of this morning, the beam energy was ramped up to 3.5 TeV, a new world record and the highest energy for this year’s run. Now operators will prepare the machine to make high-energy collisions later this month. CERN Operations Group leader Mike Lamont (foreground) and LHC engineer in charge Alick Macpherson in the CERN Control Centre early this morning. At 5:23 this morning, Friday 19 March, the energy of both beams in the LHC was ramped up to 3.5 TeV, a new world record. During the night, operators had tested the performance of the whole machine with two so-called ‘dry runs’, that is, without beams. Given the good overall response, beams were injected at around 3:00 a.m. and stabilized soon after. The ramp started at around 4:10 and lasted about one hour. Over the last couple of weeks, operation of the LHC at 450 GeV has become routinely reproducible. The operators were able to test and optimize the beam orbit, the beam collimation, the injection and ext...

  10. Inverse Resistance Change Cr2Ge2Te6-Based PCRAM Enabling Ultralow-Energy Amorphization.

    Science.gov (United States)

    Hatayama, Shogo; Sutou, Yuji; Shindo, Satoshi; Saito, Yuta; Song, Yun-Heub; Ando, Daisuke; Koike, Junichi

    2018-01-24

    Phase-change random access memory (PCRAM) has attracted much attention for next-generation nonvolatile memory that can replace flash memory and can be used for storage-class memory. Generally, PCRAM relies on the change in the electrical resistance of a phase-change material between high-resistance amorphous (reset) and low-resistance crystalline (set) states. Herein, we present an inverse resistance change PCRAM with Cr 2 Ge 2 Te 6 (CrGT) that shows a high-resistance crystalline reset state and a low-resistance amorphous set state. The inverse resistance change was found to be due to a drastic decrease in the carrier density upon crystallization, which causes a large increase in contact resistivity between CrGT and the electrode. The CrGT memory cell was demonstrated to show fast reversible resistance switching with a much lower operating energy for amorphization than a Ge 2 Sb 2 Te 5 memory cell. This low operating energy in CrGT should be due to a small programmed amorphous volume, which can be realized by a high-resistance crystalline matrix and a dominant contact resistance. Simultaneously, CrGT can break the trade-off relationship between the crystallization temperature and operating speed.

  11. Strain control of Urbach energy in Cr-doped PrFeO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Anil; Warshi, M.K.; Mishra, Vikash; Saxena, Shailendra K.; Kumar, Rajesh; Sagdeo, Pankaj R. [Indian Institute of Technology Indore, Material Research Laboratory, Discipline of Physics and MEMS, Indore (India)

    2017-09-15

    Polycrystalline samples of PrFe{sub 1-x}Cr{sub x}O{sub 3} having average particle size of ∝90 nm have been prepared by wet chemical route. The structural phase purity of the prepared samples is confirmed by powder X-ray diffraction followed by Rietveld refinements. It is observed that with Cr doping, the Urbach energy (E{sub u}) increases. The E{sub u} is measure of the various disorders present in the sample, such as chemical and structural. To understand the contribution to the E{sub u} due to chemical and structural disorders, we have probed the chemical and structural disorders in the samples by elemental mappings and through X-ray diffraction experiments, respectively. Elemental mapping confirms chemical homogeneity of prepared samples. It is observed that with Cr doping the crystallographic strain increases and Urbach energy shows the similar scaling. (orig.)

  12. Study on energy efficient mushroom business in 2010. Highest feasible level of energy conservation and energy efficiency; Onderzoek naar het energiezuinig paddenstoelenbedrijf anno 2010. Hoogst haalbare niveau van energiereductie en energie-efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Suurmeijer, J.M.; Mikkers, E. [Grontmij, Amersfoort (Netherlands); Hilkens, J. [AdVisie, Herkenbosch (Netherlands)

    2010-06-15

    Targets of Dutch mushroom cultivation businesses include an energy efficiency improvement of 2.5% annually, implementation of sustainable energy options, and climate-neutral and economically viable cultivation by new mushroom cultivation businesses that are to be built in 2020. This report describes the measures that could be implemented in support of these targets [Dutch] De doelstellingen voor paddestoelenbedrijven zijn een energie-efficientie verbetering van 2,5% per jaar, implementatie van duurzame energieopties, en klimaatneutrale en economisch rendabele teelt van de in 2020 nieuw te bouwen paddenstoelenbedrijven. In dit rapport staan de maatregelen beschreven die genomen kunnen worden ter ondersteuning van de doelstellingen.

  13. Beam profile measurement with CR-39 track detector for low-energy ions

    CERN Document Server

    Sato, F; Tanaka, T; Iida, T; Yamauchi, T; Oda, K

    1999-01-01

    A CR-39 track detector was successfully used to measure the outline of thin low-energy ion beams. After the etching, the surface of the detector was examined with an observation system composed of a Normarski microscope, a CCD camera and a digital image processing computer. Beam images obtained with the system were in good agreement on the outline of the beam formed with a beam aperture. Also, the resolving power in the beam outline measurement was roughly explained from the consideration of the ion range and the etch-pit growth in the chemical etching for the CR-39 detector.

  14. Cr and Yb markers determination in animal feces by energy dispersive X-ray fluorescence

    International Nuclear Information System (INIS)

    Almeida, Eduardo de; Senicato, Luis A; Nascimento Filho, Virgilio F.; Gomide, Catarina A.

    2007-01-01

    Chromium and Ytterbium elements are utilized in animal nutritional studies as markers. This paper describes an analytical method for Cr and Yb determination in solid buffalo feces sample using standard addition method and energy dispersive X-ray spectrometry (EDXRF) technique. One gram dried sample was pressed manually in an XRF sample cup with Mylar film (6.3 μm thickness) in the bottom. The experimental conditions were: Mo target X-ray tube with Zr filter, operated at 25 kV/10 mA, and 500 s of acquisition time. The limits of detection for Cr and Yb were 16.6 and 11.4 mg/kg, respectively. This methodology has showed appropriated for simultaneous Cr and Yb determination as marker in animal feces. (author)

  15. Cr and Yb markers determination in animal feces by energy dispersive X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Eduardo de; Senicato, Luis A; Nascimento Filho, Virgilio F. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Instrumentacao Nuclear (LIN)]. E-mail: edualm@usp.br; Gomide, Catarina A. [Universidade de Sao Paulo (USP), Pirassununga, SP (Brazil). Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Dept. de Zootecnia]. E-mail: cbgomide@usp.br

    2007-07-01

    Chromium and Ytterbium elements are utilized in animal nutritional studies as markers. This paper describes an analytical method for Cr and Yb determination in solid buffalo feces sample using standard addition method and energy dispersive X-ray spectrometry (EDXRF) technique. One gram dried sample was pressed manually in an XRF sample cup with Mylar film (6.3 {mu}m thickness) in the bottom. The experimental conditions were: Mo target X-ray tube with Zr filter, operated at 25 kV/10 mA, and 500 s of acquisition time. The limits of detection for Cr and Yb were 16.6 and 11.4 mg/kg, respectively. This methodology has showed appropriated for simultaneous Cr and Yb determination as marker in animal feces. (author)

  16. Energy transfer efficiency from Cr(3+) to Nd(3+) in solar-pumped laser using transparent Nd/Cr:Y(3)Al(5)O(12) ceramics.

    Science.gov (United States)

    Hasegawa, Kazuo; Ichikawa, Tadashi; Mizuno, Shintaro; Takeda, Yasuhiko; Ito, Hiroshi; Ikesue, Akio; Motohiro, Tomoyoshi; Yamaga, Mitsuo

    2015-06-01

    We report energy transfer efficiency from Cr3+ to Nd3+ in Nd (1.0 at.%)/Cr (0.4 at.%) co-doped Y3Al5O12 (YAG) transparent ceramics in the laser oscillation states. The laser oscillation has performed using two pumping lasers operating at 808 nm and 561 nm; the former pumps Nd3+ directly to create the 1064 nm laser oscillation, whereas the latter assists the performance via Cr3+ absorption and sequential energy transfer to Nd3+. From the laser output power properties and laser mode analysis, the energy transfer efficiency was determined to be around 65%, which is close to that obtained from the spontaneous Nd3+ emission.

  17. Response of CR-39 SSNTD to high energy neutrons using zirconium convertors - a Monte Carlo and experimental study

    International Nuclear Information System (INIS)

    Pal, Rupali; Sapra, B.K.; Bakshi, A.K.; Datta, D.; Biju, K.; Suryanarayana, S.V.; Nayak, B.K.

    2016-01-01

    Neutron dosimetry in ion accelerators is a challenging field as the neutron spectrum varies from thermal, to fast and high-energy neutrons usually extending beyond 20 MeV. Solid-state Nuclear Track Detectors (SSNTDs) have been increasingly used in numerous fields related to nuclear physics. Extensive work has also been carried out on determining the response characteristics of such detectors as nuclear spectrometers. In nuclear reaction studies, identification of reaction products according to their type and energy is frequently required. For normally incident particles, energy-dispersive track-diameter methods have become useful scientific tools using CR-39 SSNTD. CR-39 along with 1 mm polyethylene convertor can cover a neutron energy range from 100 keV to 10 MeV. The neutron interacts with the hydrogen in CR-39 producing recoil protons from elastic collisions. This detectable neutron energy range can be increased by modification in the radiator/convertor used along with CR-39. CR39 detectors placed in conjunction with judiciously chosen thicknesses of a polyethylene radiator and a lead absorber (or degrader) are used to increase energy range upto 19 MeV. A portable neutron counter has been proposed for high-energy neutron measurement with 1 cm thick Zirconium (Zr) as the converter outside a spherical HDPE shell of 7 inch diameter. Zr metal has been found to show (n,2n) cross section for energies above 10 MeV starting from 0.01 barns for 8 MeV upto 1 barns for 22 MeV. Above these energies, the experimental data is scarce. In this paper, Zr was used in conjunction with CR-39 which showed an enhancement of track density on the CR-39. This paper demonstrates the enhancement of neutron response using Zr on CR-39 with both theoretical and experimental studies

  18. Electronic structure of the Ga1-xCr xN studied by high-energy photoemission spectroscopy

    International Nuclear Information System (INIS)

    Kim, J.J.; Makino, H.; Yao, T.; Takata, Y.; Kobayashi, K.; Yamamoto, T.; Hanada, T.; Cho, M.W.; Ikenaga, E.; Yabashi, M.; Miwa, D.; Nishino, Y.; Tamasaku, K.; Ishikawa, T.; Shin, S.

    2005-01-01

    Valence band spectra of Ga 1-x Cr x N have been investigated by high-energy photoemission spectroscopy at the photon energy of 5.95 keV. Cr doping does introduce a novel electronic structure in the bandgap and causes some change in valence band structure. Based on the first-principle calculation, Cr-associated electronic levels in the bandgap are assigned to nonbonding and antibonding d states while the change of the valence band suggests that the Ga 4s originated states are significantly modified through hybridization with the Cr 3d orbital. The present result evidences that the Ga valence electrons are considerably modified through the interaction with the second nearest-neighbour Cr atoms

  19. Lowest cost due to highest productivity and highest quality

    Science.gov (United States)

    Wenk, Daniel

    2003-03-01

    Since global purchasing in the automotive industry has been taken up all around the world there is one main key factor that makes a TB-supplier today successful: Producing highest quality at lowest cost. The fact that Tailored Blanks, which today may reach up to 1/3 of a car body weight, are purchased on the free market but from different steel suppliers, especially in Europe and NAFTA, the philosophy on OEM side has been changing gradually towards tough evaluation criteria. "No risk at the stamping side" calls for top quality Tailored- or Tubular Blank products. Outsourcing Tailored Blanks has been starting in Japan but up to now without any quality request from the OEM side like ISO 13919-1B (welding quality standard in Europe and USA). Increased competition will automatically push the quality level and the ongoing approach to combine high strength steel with Tailored- and Tubular Blanks will ask for even more reliable system concepts which enables to weld narrow seams at highest speed. Beside producing quality, which is the key to reduce one of the most important cost driver "material scrap," in-line quality systems with true and reliable evaluation is going to be a "must" on all weld systems. Traceability of all process related data submitted to interfaces according to customer request in combination with ghost-shift-operation of TB systems are tomorrow's state-of-the-art solutions of Tailored Blank-facilities.

  20. Alpha particle spectroscopy for CR-39 detector utilizing matrix of energy equations

    Energy Technology Data Exchange (ETDEWEB)

    Awad, E.M. [Department of General Sciences, Yanbu Industrial College, PO Box 30436, Madinat Yanbu Al-Sinaiya (Saudi Arabia); Physics Department, Faculty of Science, Menofia University, Shebin El-Koom (Egypt)], E-mail: ayawad@yahoo.com; Soliman, A.A. [Department of Mathematics, Faculty of Education (AL-Arish), Suez Canal University, AL-Arish 45111 (Egypt); Department of Mathematics, Teacher' s College (Bisha), King Khalid University, Bisha, PO Box 551 (Saudi Arabia)], E-mail: asoliman_99@yahoo.com; Rammah, Y.S. [Physics Department, Faculty of Science, Menofia University, Shebin El-Koom (Egypt)

    2007-10-01

    A method for determining alpha-particle energy using CR-39 detector by utilizing matrix of energy equation was described. The matrix was composed from two axes; the track minor axis (m) and diameter of etched out track end (d) axis of some selected elliptical tracks. The energy E in (m,d) coordinate was approximated by matrix of energy equations given by: E{sub k}={sigma}{sub i,j=0}{sup 2}a{sub ij}d{sub k}{sup i}m{sub k}{sup j}, which was identified using two different approaches. First, i and j were treated as power exponents for d and m. The adjusting parameters values a{sub ij} were obtained and the energy of a given track was deduced directly from it. Second, i and j were treated as indices of some chosen tracks that were fitted to obtain iso-energy curves that were superimposed on m-d scatter plot as calibration curves. The energy between any two successive iso-energy curves in this case was assumed varied linearly with d for a given m. The energy matrix in both cases was solved numerically. Results of the two approaches were compared.

  1. FeCrAl and Zr alloys joined using hot isostatic pressing for fusion energy applications

    International Nuclear Information System (INIS)

    Park, Dong Jun; Kim, Hyun Gil; Park, Jeong Yong; Jung, Yang Il; Park, Jung Hwan; Koo, Yang Hyun

    2016-01-01

    Highlights: • FeCrAl and Zr alloys were successfully joined by hot isostatic pressing (HIP). • The thickness of diffusion layer increased with an increase in HIP temperature. • Significant inter-diffusion was observed for HIP at 1150 °C. • Maximum joint strength was achieved at HIP temperature of 700 °C. - Abstract: FeCrAl and Zr alloys were joined by a hot isostatic pressing (HIP) method for fusion energy applications. The optimum conditions for the joining process were studied. The HIP temperatures were varied from 700 to 1050 °C. The mechanical properties of the HIPed samples were evaluated by four-point bending and tensile tests. The FeCrAl and Zr alloys HIPed at 700 °C showed higher joint strength than the other samples. The joint strength decreased with an increase in the HIP temperature from 700 to 950 °C and significantly dropped at 1050 °C. Transmission electron microscopy, scanning electron microscopy, and optical microscopy were used to characterize the joints and interface region of the HIPed samples. The joints appeared to be tightly bonded and no intermetallic compounds or gaps were observed at the interface for HIP temperatures up to 950 °C. A diffusion layer formed at the interface and its thickness increased with the HIP temperature. HIP at 1050 °C, on the other hand, resulted in significant inter-diffusion and formation of brittle inter-metallic compounds at the interface.

  2. Vermont Highest Priority Connectivity Blocks

    Data.gov (United States)

    Vermont Center for Geographic Information — Act 174 requires plans to identify potential areas for the development and siting of renewable energy resources and areas that are unsuitable for siting those...

  3. Activation energy of etching for CR-39 as a function of linear energy transfer of the incident particles

    CERN Document Server

    Awad, E M

    1999-01-01

    In this work, we have studied the effect of the radiation damage caused by the incident particles on the activation energy of etching for CR-39 samples. The damage produced by the incident particle is expressed in terms of the linear energy transfer (LET). CR-39 samples from American Acrylic were irradiated to three different LET particles. These are N (LET sub 2 sub 0 sub 0 = 20 KeV/mu m) as a light particle, Fe (LET sub 2 sub 0 sub 0 = 110 KeV/mu m) as a medium particle and fission fragments (ff) from a sup 2 sup 5 sup 2 Cf source as heavy particles. In general the bulk etch rate was calculated using the weight difference method and the track etch rate was determined using the track geometry at various temperatures (50-90 deg. C) and concentrations (4-9 N) of the NaOH etchant. The average activation energy E sub b related to the bulk etch rate v sub b was calculated from 1n v sub b vs. 1/T. The average activation energy E sub t related to the track etch rate v sub t was estimated from 1n v sub t vs. 1/T. It...

  4. Energy spectrum of iron nuclei measured inside the MIR space craft using CR-39 track detectors

    International Nuclear Information System (INIS)

    Guenther, W.; Leugner, D.; Becker, E.; Flesch, F.; Heinrich, W.; Huentrup, G.; Reitz, G.; Roecher, H.; Streibel, T.

    1999-01-01

    We have exposed stacks of CR-39 plastic nuclear track detectors inside the MIR space craft during the EUROMIR95 space mission for almost 6 months. Over this long period a large number of tracks of high LET events was accumulated in the detector foils. The etching and measuring conditions for this experiment were optimized to detect tracks of stopping iron nuclei. We found 185 stopping iron nuclei inside the stack and identified their trajectories through the material of the experiment. Based on the energy-range relation the energy at the surface of the stack was determined. These particles allow the determination of the low energy part of the spectrum of iron nuclei behind shielding material inside the MIR station

  5. CR-39 nuclear track detector application for the diagnostics of low energy high power ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Opekounov, M S; Pechenkin, S A; Remnev, G E [Nuclear Physics Institute, Tomsk (Russian Federation); Ivonin, I V [Siberian Physical-Technical Institute, Tomsk (Russian Federation)

    1997-12-31

    The results of investigation of the spectral composition of ion beams generated by the magneto-insulated ion diode of the MUK-M and TEMP accelerators. The energy and mass characteristics of the accelerated ion beam were determined by a Thomson spectrometer with a CR-39 plate detector (MOM - Atomki Nuclear Track Detector, Type MA-ND/p). The accelerated ion energy was from 40 to 240 keV. The ion current density range was from 1 to 10 A/cm{sup 2}. The mass composition contained hydrogen, nitrogen, carbon and aluminum ions. The individual track analysis showed the track form, depth and diameter in dependence on the ion mass and energy. (author). 2 figs., 5 refs.

  6. Local Energies and Energy Fluctuations — Applied to the High Entropy Alloy CrFeCoNi

    Science.gov (United States)

    Fukushima, Tetsuya; Katayama-Yoshida, Hiroshi; Sato, Kazunori; Ogura, Masako; Zeller, Rudolf; Dederichs, Peter H.

    2017-11-01

    High entropy alloys show a variety of fascinating properties like high hardness, wear resistance, corrosion resistance, etc. They are random solid solutions of many components with rather high concentrations. We perform ab-initio calculations for the high entropy alloy CrFeCoNi, which equal concentration of 25% for each element. By the KKRnano program package, which is based on an order-N screened Korringa-Kohn-Rostoker Green's function method, we consider a face-centered cubic (FCC) supercell with 1372 randomly distributed elements, and in addition also smaller supercells with 500 and 256 atoms. It is found from our calculations that the local moments of the Cr atoms show a large environmental variation, ranging from -1.70 μB to +1.01 μB with an average of about -0.51 μB. We present a new method to calculate "local energies" of all atoms. This is based on the partitioning of the whole space into Voronoi cells and allows to calculate the energetic contribution of each atomic cell to the total energy of the supercell. The supercell calculations show very large variations of the local energies, analogous to the variations of the local moments. This shows that the random solid solution is not stable and has a tendency to form an L12-structure with the Cr-atoms ordered at the corner of the cube and the elements Fe, Co, and Ni randomly distributed on the three other FCC sublattices. For this structure the variation of the local moments are much smaller.

  7. Some characteristics of the CR-39 solid state nuclear - Track Detector for register of protons and low energy alpha particles

    International Nuclear Information System (INIS)

    Fonseca, E.S. da.

    1983-01-01

    Experimental results related to registration properties of the CR-39 Solid State Nuclear Track Detector for charged particles are presented and discussed. The existence of an inverse proportion between the induction time and the temperature as well as normal concentration of solutions, is showed by the study of CR-39 chemical etching characteristics in NaOH and KOH solutions, comprising varied concentration and temperature. The bulk-etch rate and activation energy of the process were obtained. The critical energy and critical energy-loss rate of CR-39 track-detectors for registration of protons were experimentally determined. Samples were exposed to 24 Mev proton beams in the IEN/CNEN Cyclotron (CV-28), using scattering chamber with a tantalum thin target and aluminium absorbers in contact with the samples, in order to provide the required fluctuation in the scattered beam energy. From the mean track-diameter plotted against incident proton energy the critical energy was obtained. From the calculated energy-loss rate vs. energy curve, the critical energy loss rate were evaluated. The CR-39 response for low energy alpha particles (E = 7h) under the conditions of 6.25 N NaOH at 70 0 C. It is shown that successive chemical etchings do not produce the same track geometry as obtained by means of a continous revelation with the same total etching time. (Author) [pt

  8. Energy transfer from Cr to Nd in substitutional crystal Y{sub 3}Ga{sub x}Al{sub 5−x}O{sub 12} codoped with Nd and Cr

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, Kazuki [Department of Mathematical and Design Engineering, Gifu University, Gifu 501-1193 (Japan); Yamaga, Mitsuo, E-mail: yamaga@gifu-u.ac.jp [Department of Mathematical and Design Engineering, Gifu University, Gifu 501-1193 (Japan); Villora, Encarnacion G.; Shimamura, Kiyoshi [National Institute for Materials Science, Tsukuba 305-0044 (Japan); Hasegawa, Kazuo; Ito, Hiroshi; Mizuno, Shintaro; Takeda, Yasuhiko [Toyota Central R& D Laboratories, Nagakute 480-1192 (Japan); Han, Thomas P.J. [Department of Physics, University of Strathclyde, Glasgow G4 0NG, Scotland (United Kingdom)

    2016-01-15

    Garnet crystals codoped with Nd{sup 3+} and Cr{sup 3+} ions are a candidate for solar-pumped laser materials. Substitutional disordered crystals Y{sub 3}Ga{sub x}Al{sub 5−x}O{sub 12} were prepared to improve the pumping efficiency of Nd{sup 3+} luminescence and energy transfer from Cr{sup 3+} to Nd{sup 3+} ions. The substitutional disordered crystal host produced inhomogeneous broadening of the Nd{sup 3+} and Cr{sup 3+} optical spectra. Enhancement of overlapping between the Cr{sup 3+} absorption bands and the solar spectrum, and between the Cr{sup 3+} luminescence bands and the Nd{sup 3+} absorption lines led to the increases of the pumping efficiency and the energy transfer rates, respectively. The excitation spectrum of the Nd{sup 3+} luminescence, the nonexponential decay curves of the Cr{sup 3+} luminescence, and the quantum yields of the Cr{sup 3+} and Nd{sup 3+} luminescence have given evidence on the energy transfer from Cr{sup 3+} to Nd{sup 3+} ions. - Highlights: • Substitutional disordered garnet crystals as solar-pumped laser materials. • Inhomogeneous broadening of Nd{sup 3+} and Cr{sup 3+} optical spectra. • Enhancement of energy transfer from Cr{sup 3+} to Nd{sup 3+} due to inhomogeneous broadening.

  9. Consequence of doping mediated strain and the activation energy on the structural and optical properties of ZnO:Cr nanoparticles

    International Nuclear Information System (INIS)

    Bhargava, Richa; Sharma, Prashant K.; Kumar, Sanjeev; Pandey, Avinash C.; Kumar, Naresh

    2010-01-01

    We report on the sol-gel synthesis of Zn 1-x Cr x O (x=0.0, 0.05, 0.10, 0.15 and 0.20) nanoparticles. These nanoparticles were characterized by using thermogravimetry/differential scanning calorimetry (TG/DSC), X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman and Photoluminescence (PL). Electronegativity of Cr ions (Cr 3+ ) reduces the final decomposition temperature by 40 o C and activation energy of the reaction when Cr is doped into ZnO. Doping of higher Cr concentration (x≥0.10) into ZnO shows formation of secondary spinel (ZnCr 2 O 4 ) phase along with the hexagonal (ZnO) and is revealed by XRD. Formation of secondary phase changes the activation energy of the reaction and thus the strain in ZnO lattice. In Raman spectra, additional Raman modes have been observed for Zn 1-x Cr x O nanoparticles, which can be assigned to the modes generated due to Cr doping. The Cr doping into ZnO is also supported by PL, in which vacancies are formed with Cr ion incorporation and emission band shifts towards higher wavelength. - Graphical abstract: Cr-doped ZnO nanostructures were synthesized by sol-gel. XRD (a) revealed secondary phase of ZnCr 2 O 4 with increase in Cr concentration. The Cr concentration also changes activation energy of the reaction (b).

  10. Electron energy loss spectroscopy of CH3N2CH3 adsorbed on Ni(100), Ni(111), Cr(100), Cr(111)

    International Nuclear Information System (INIS)

    Schulz, M.A.

    1985-07-01

    A study of the adsorption of CH 3 N 2 CH 3 on Ni(100), Ni(111), Cr(100), and Cr(111) using high resolution electron energy loss spectroscopy (EELS) is presented. Under approximately the same conditions of coverage, the vibrational spectra of CH 3 N 2 CH 3 on these four surfaces are quite distinct from one another, implying that the CH 3 N 2 CH 3 -substrate interaction is very sensitive to the physical and electronic structure of each surface. In addition to the room temperature studies, the evolution of surface species on the Ni(100) surface in the temperature range 300 to 425 K was studied. Analysis of the Ni(100) spectra indicates that molecular adsorption, probably through the N lone pair, occurs at room temperature. Spectra taken after annealing the CH 3 N 2 CH 3 -Ni(100) surfaces indicate that CH and CN bond scission occurred at the elevated temperatures. Decomposition of CH 3 N 2 CH 3 takes place on the Ni(111), Cr(100), and Cr(111) surfaces at room temperature, as evidenced by the intensity of the carbon-metal stretch in the corresponding spectra. Possible identities of coadsorbed dissociation products are considered. The stable coverage of surface species on all four surfaces at 300 K is less than one monolayer. A general description of an electron energy loss (EEL) spectrometer is given. Followed by a more specific discussion of some recent modifications to the EEL monochromator assembly used in this laboratory. Both the previous configuration of our monochromator and the new version are briefly described, as an aid to understanding the motivation for the changes as well as the differences in operation of the two versions. For clarity, the new monochromator design is referred to as variable pass, while the previous design is referred to as double pass. A modified tuning procedure for the new monochromator is also presented. 58 refs., 11 figs

  11. Stacking fault energy measurements in solid solution strengthened Ni-Cr-Fe alloys using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Unfried-Silgado, Jimy [Metals Characterization and Processing Laboratory, Brazilian Nanothecnology National Laboratory - CNPEM/ABTLuS, Caixa Postal 6192, CEP 13083-970, Campinas, Sao Paulo (Brazil); Universidade Estadual de Campinas UNICAMP, Faculdade de Engenharia Mecanica FEM, Campinas (Brazil); Universidad Autonoma del Caribe, Grupo IMTEF, Ingenieria Mecanica, Barranquilla (Colombia); Wu, Leonardo [Metals Characterization and Processing Laboratory, Brazilian Nanothecnology National Laboratory - CNPEM/ABTLuS, Caixa Postal 6192, CEP 13083-970, Campinas, Sao Paulo (Brazil); Furlan Ferreira, Fabio [Universidade Federal do ABC, Centro de Ciencias Naturais e Humanas (CCNH), Sao Paulo (Brazil); Mario Garzon, Carlos [Universidad Nacional de Colombia, Departamento de Fisica, Bogota (Colombia); Ramirez, Antonio J, E-mail: antonio.ramirez@lnnano.org.br [Metals Characterization and Processing Laboratory, Brazilian Nanothecnology National Laboratory - CNPEM/ABTLuS, Caixa Postal 6192, CEP 13083-970, Campinas, Sao Paulo (Brazil)

    2012-12-15

    The stacking fault energy (SFE) in a set of experimental Ni-Cr-Fe alloys was determined using line profile analysis on synchrotron X-ray diffraction measurements. The methodology used here is supported by the Warren-Averbach calculations and the relationships among the stacking fault probability ({alpha}) and the mean-square microstrain (<{epsilon}{sup 2}{sub L}>). These parameters were obtained experimentally from cold-worked and annealed specimens extracted from the set of studied Ni-alloys. The obtained results show that the SFE in these alloys is strongly influenced by the kind and quantity of addition elements. Different effects due to the action of carbide-forming elements and the solid solution hardening elements on the SFE are discussed here. The simultaneous addition of Nb, Hf, and, Mo, in the studied Ni-Cr-Fe alloys have generated the stronger decreasing of the SFE. The relationships between SFE and the contributions on electronic structure from each element of additions were established.

  12. An energy and direction independent fast neutron dosemeter based on electrochemically etched CR-39 nuclear track detectors

    International Nuclear Information System (INIS)

    James, K.; Matiullah; Durrani, S.A.

    1987-01-01

    A computer-based model is presented, which simulates the dose equivalent response of electrochemically etched CR-39 to fast neutrons of various energies and angles of incidence. Most previous calculations of the response of CR-39 have neglected the production of recoiling oxygen and carbon nuclei as well as α particles in the CR-39. We calculate that these 'heavy recoils' and α particles are the major source of electrochemically etchable tracks in bare CR-39 at neutron energies above approx. 2 MeV under typical etching conditions. Our calculations have been extended to predict the response of CR-39 used in conjunction with various combinations of polymeric front radiators and we have determined the radiator stack configuration with produces the most energy independent response. Again, the heavy recoils and α particles cannot be neglected and, for energies above approx. 2 MeV, these produce typically about 20% of the total response of our optimum stack. This type of fast neutron dosemeter is, however, strongly direction dependent. We have integrated the response over all appropriate angles to predict the dose equivalent response for two representative neutron fields, and we suggest a method for minimising the angular dependence. (author)

  13. Gibbs free energy difference between the undercooled liquid and the beta phase of a Ti-Cr alloy

    Science.gov (United States)

    Ohsaka, K.; Trinh, E. H.; Holzer, J. C.; Johnson, W. L.

    1992-01-01

    The heat of fusion and the specific heats of the solid and liquid have been experimentally determined for a Ti60Cr40 alloy. The data are used to evaluate the Gibbs free energy difference, delta-G, between the liquid and the beta phase as a function of temperature to verify a reported spontaneous vitrification (SV) of the beta phase in Ti-Cr alloys. The results show that SV of an undistorted beta phase in the Ti60Cr40 alloy at 873 K is not feasible because delta-G is positive at the temperature. However, delta-G may become negative with additional excess free energy to the beta phase in the form of defects.

  14. Some characteristics of the CR-39 solid state nuclear-track detector for protons and low energy alpha particles

    International Nuclear Information System (INIS)

    Fonseca, E.S. da.

    1983-01-01

    Experimental results related to certain registration properties of the CR-39 solid state nuclear-track detector for charged particles are presented and discussed. The determination of the CR-39 chemical etching in NaOH and KOH solutions, comprising concentration (2-10N) and temperature effects (50-90 0 C), showed the existence of an inverse proportion between the induction time and the temperature as well as the normal concentration of the solutions. The critical energy and the critical energy-loss rate of CR-39 track detectors for registration of protons were experimentally determined. A number of samples was exposed to 24MeV proton beams in the IEN-CNEN Cyclotron (CV-28), using a scattering chamber with a tantalum thin target and aluminium absorbers in contact with the samples in order to provide the required fluctuation in the scattered beam energy. From the mean track-diameter plotted against incident proton energy for 16h and 24h chemical etching (6.25 NaOH, 70 0 C), and considering 1.5 μm as the minimum observable track-diameter, the values (21.0 + - 1.5) MeV and (22.5 + - 1.5) MeV were deduced, respectively, for the critical energy. From the calculated energy-loss rate versus energy curve, the critical energy-loss rate was evaluated as 24 + - 2 MeV.cm 2 /g. Finally, the CR-39 response for low energy alpha particles (E [pt

  15. High temperature tensile testing of modified 9Cr-1Mo after irradiation with high energy protons

    International Nuclear Information System (INIS)

    Toloczko, M.B.; Hamilton, M.L.; Maloy, S.A.

    2003-01-01

    This study examines the effect of tensile test temperatures ranging from 50 to 600 deg. C on the tensile properties of a modified 9Cr-1Mo ferritic steel after high energy proton irradiation at about 35-67 deg. C to doses from 1 to 3 dpa and 9 dpa. For the specimens irradiated to doses between 1 and 3 dpa, it was observed that the yield strength and ultimate strength decreased monotonically as a function of tensile test temperature, whereas the uniform elongation (UE) remained at approximately 1% for tensile test temperatures up to 250 deg. C and then increased for tensile test temperatures up to and including 500 deg. C. At 600 deg. C, the UE was observed to be less than the values at 400 and 500 deg. C. UE of the irradiated material tensile tested at 400-600 deg. C was observed to be greater than the values for the unirradiated material at the same temperatures. Tensile tests on the 9 dpa specimens followed similar trends

  16. Precise Wavelengths and Energy Levels for the Spectra of Cr I, Mn I, and Mn III, and Branching Fractions for the Spectra of Fe II and Cr II

    Science.gov (United States)

    Nave, Gillian

    I propose to measure wavelengths and energy levels for the spectra of Cr I, Mn I, and Mn III covering the wavelength range 80 nm to 5500 nm, and oscillator strengths for Fe II and Cr II in the region 120 nm to 2500 nm. I shall also produce intensity calibrated atlases and linelists of the iron-neon and chromium-neon hollow cathode lamps that can be compared with astrophysical spectra. The spectra will be obtained from archival data from spectrometers at NIST and Kitt Peak National Observatory and additional experimental observations as necessary from Fourier transform (FT) and grating spectrometers at NIST. The wavelength uncertainty of the strong lines will be better than 1 part in 10^7. The radiometric calibration of the spectra will be improved in order to reduce the uncertainty of measured oscillator strengths in the near UV region and extend the wavelength range of these measurements down to 120 nm. These will complement and support the measurements of lifetimes and branching fractions by J. E. Lawler in the near UV region. An intensive effort by NIST and Imperial College London that was partly funded by previous NASA awards has resulted in comprehensive analyses of the spectra of Fe II, Cr II and Cu II, with similar analyses of Mn II, Ni II, and Sc II underway. The species included in this proposal will complete the analysis of the first two ionization stages of the elements titanium through nickel using the same techniques, and add the spectrum of Mn III - one of the most important doubly-ionized elements. The elements Cr I and Mn I give large numbers of spectral lines in spectra of cool stars and important absorption lines in the interstellar medium. The spectrum of Mn III is important in chemically peculiar stars and can often only be studied in the UV region. Analyses of many stellar spectra depend on comprehensive analyses of iron-group elements and are hampered by incomplete spectroscopic data. As a result of many decades of work by the group at the

  17. Synthesis and energy transfer studies of LaMgAl{sub 11}O{sub 19}:Cr{sup 3+}, Nd{sup 3+} phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Jicheng; Xia, Zhiguo; Liu, Quanlin, E-mail: qlliu@ustb.edu.cn

    2016-02-15

    Highlights: • Cr{sup 3+}/Nd{sup 3+} co-doped LaMgAl{sub 11}O{sub 19} phosphors were synthesized. • The energy transfer mechanism is ascribed to the dipole–quadrupole interaction. • The materials can convert the UV–vis light into near-infrared emission. - Abstract: Cr{sup 3+}/Nd{sup 3+} co-activated LaMgAl{sub 11}O{sub 19} phosphors have been synthesized by high temperature solid-state method. In the LaMgAl{sub 11}O{sub 19}:Cr{sup 3+}/Nd{sup 3+} system, Cr{sup 3+} can absorb the UV–vis photons (350–650 nm), and then energy transfer takes place between Cr{sup 3+} and Nd{sup 3+}, and finally the samples give near infrared emission originated from Nd{sup 3+}. Energy transfer from Cr{sup 3+} to Nd{sup 3+} is discussed via the variations of the lifetime values of Cr{sup 3+}, and the mechanism has been ascribed to the dipole–quadrupole interaction. The absorption of Cr{sup 3+} in the visible region and the following energy transfer from Cr{sup 3+} to Nd{sup 3+} indicated that the material can potentially serve as spectral convertors to improve the photovoltaic conversion efficiency of silicon-based solar cell.

  18. Study of α-energy discrimination in CR-39 track etch detectors for use as a radon/thoron dosemeter

    International Nuclear Information System (INIS)

    Kandaiya, S.; Al-Najjar, S.A.R.; Piesch, E.

    1988-01-01

    The properties of CR 39 nuclear track detectors were evaluated for their α-energy discrimination up to 8.77 MeV using a combination of chemical-electrochemical track revealing techniques. Using three field strengths, α-energy discrimination by ECE track diameter and track density as a function of chemical pre-etching time were studied. α-energy spectra using different irradiation geometries were then evaluated using the optimum conditions and then compared with those obtained form other techniques. (author)

  19. Low-energy elastic-scattering of alpha particles from [sup 34]S, [sup 50]Cr and [sup 62]Ni

    Energy Technology Data Exchange (ETDEWEB)

    Bredbacka, AA. (Department of Physics, AAbo Akademi, 20500 AAbo (Finland)); Brenner, M. (Department of Physics, AAbo Akademi, 20500 AAbo (Finland)); Kaellman, K.-M. (Department of Physics, AAbo Akademi, 20500 AAbo (Finland)); Manngaard, P. (Department of Physics, AAbo Akademi, 20500 AAbo (Finland)); Mate, Z. (Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen Pf. 51 (Hungary)); Szilagyi, S. (Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen Pf. 51 (Hungary)); Zolnai, L. (Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen Pf. 51 (Hungary))

    1994-07-11

    Angular distributions of elastically scattered alpha particles were measured for the [sup 34]S, [sup 50]Cr and [sup 62]Ni target nuclei in the energy range 12.8-20.0 MeV. The experimental data were analysed using the phenomenological optical model with the Saxon-Woods form factor; in the case of [sup 34]S the squared Saxon-Woods form factor was also applied. Phenomena such as the anomalous energy dependence of the potential near the Coulomb barrier, the discrete ambiguity problem, the low-mass and low-energy limit of applicability of the optical model are discussed using the real volume integral values obtained. ((orig.))

  20. Microstructure and morphology of powder particles TiC-NiCr, synthesized in plasma jet, at high-energy actions on components of initial composition Ti-C-NiCr

    Science.gov (United States)

    Solonenko, Oleg P.; Smirnov, Andrey V.; Chesnokov, Anton E.

    2017-10-01

    The results of experiments on in-situ synthesis of the microspherical, in particular hollow, cermet powder TiC- 30vol.%NiCr at processing of the Ti-C-NiCr agglomerates in argon-helium plasma jet flowing out into controlled atmosphere are presented. Preparation of the agglomerates consisted of the following stages: (i) high-energy treatment of the initial powders Ti and NiCr in planetary mill with their subsequent uniform mixing with glass black powder, (ii) preparation of dough from mechanically mixed powders and binder, and their granulation using the extrusion method, (iii) drying and classification of granules by the sizes.

  1. Vacancy migration energy dependence on local chemical environment in Fe–Cr alloys: A Density Functional Theory study

    Energy Technology Data Exchange (ETDEWEB)

    Costa, D., E-mail: davide.costa.ge@gmail.com [Unité Matériaux et Transformations, CNRS UMR8207, Université de Lille 1, F-59655 Villeneuve d’Ascq Cédex (France); EDF-R and D Département MMC, Les Renardières, F-77818 Moret sur Loing Cédex (France); Laboratoire commun (EDF–CNRS): Etude et Modélisation des Microstructures pour le Vieillissement des Matériaux (EM2VM) (France); Adjanor, G. [EDF-R and D Département MMC, Les Renardières, F-77818 Moret sur Loing Cédex (France); Laboratoire commun (EDF–CNRS): Etude et Modélisation des Microstructures pour le Vieillissement des Matériaux (EM2VM) (France); Becquart, C.S. [Unité Matériaux et Transformations, CNRS UMR8207, Université de Lille 1, F-59655 Villeneuve d’Ascq Cédex (France); Laboratoire commun (EDF–CNRS): Etude et Modélisation des Microstructures pour le Vieillissement des Matériaux (EM2VM) (France); Olsson, P. [Laboratoire commun (EDF–CNRS): Etude et Modélisation des Microstructures pour le Vieillissement des Matériaux (EM2VM) (France); KTH Royal Institute of Technology, Reactor Physics, Roslagstullsbacken 21, 106 91 Stockholm (Sweden); and others

    2014-09-15

    The first step towards the understanding and the modelling of the Fe–Cr alloy kinetic properties consists in estimating the migration energies related to the processes that drive the microstructure evolution. The vacancy’s migration barrier is expected to depend on the vacancy–migrating atom pair atomic environment as pointed out by Nguyen-Manh et al. or Bonny et al. In this paper, we address the issue of the dependence on the vacancy’s local atomic environment of both the vacancy migration energy and the configurational energy change ΔE that occurs when the vacancy jumps towards one of its nearest neighbour sites. A DFT approach is used to determine the ground state energy associated to a given configuration of the system. The results are interpreted in the light of the chromium–chromium and chromium–vacancy binding energies as well as the substitutional chromium atoms magnetic properties.

  2. Nuclear Energy Advanced Modeling and Simulation (NEAMS) Accident Tolerant Fuels High Impact Problem: Coordinate Multiscale FeCrAl Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Gamble, K. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hales, J. D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Y. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Andersson, D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Capolungo, L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wirth, B. D. [Univ. of Tennessee, Knoxville, TN (United States)

    2017-07-26

    Since the events at the Fukushima-Daiichi nuclear power plant in March 2011 significant research has unfolded at national laboratories, universities and other institutions into alternative materials that have potential enhanced ac- cident tolerance when compared to traditional UO2 fuel zircaloy clad fuel rods. One of the potential replacement claddings are iron-chromium-alunimum (FeCrAl) alloys due to their increased oxidation resistance [1–4] and higher strength [1, 2]. While the oxidation characteristics of FeCrAl are a benefit for accident tolerance, the thermal neu- tron absorption cross section of FeCrAl is about ten times that of Zircaloy. This neutronic penalty necessitates thinner cladding. This allows for slightly larger pellets to give the same cold gap width in the rod. However, the slight increase in pellet diameter is not sufficient to compensate for the neutronic penalty and enriching the fuel beyond the current 5% limit appears to be necessary [5]. Current estimates indicate that this neutronic penalty will impose an increase in fuel cost of 15-35% [1, 2]. In addition to the neutronic disadvantage, it is anticipated that tritium release to the coolant will be larger because the permeability of hydrogen in FeCrAl is about 100 times higher than in Zircaloy [6]. Also, radiation-induced hardening and embrittlement of FeCrAl need to be fully characterized experimentally [7]. Due to the aggressive development schedule for inserting some of the potential materials into lead test assemblies or rods by 2022 [8] multiscale multiphysics modeling approaches have been used to provide insight into these the use of FeCrAl as a cladding material. The purpose of this letter report is to highlight the multiscale modeling effort for iron-chromium-alunimum (FeCrAl) cladding alloys as part of the Nuclear Energy Advanced Modeling and Simulation (NEAMS) program through its Accident Tolerant Fuel (ATF) High Impact Problem (HIP). The approach taken throughout the HIP is to

  3. Electronic structure of metastable bcc Cu–Cr alloy thin films: Comparison of electron energy-loss spectroscopy and first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Liebscher, C.H.; Freysoldt, C. [Max-Planck-Institut für Eisenforschung GmbH, 40237 Düsseldorf (Germany); Dennenwaldt, T. [Institute of Condensed Matter Physics and Interdisciplinary Center for Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne (Switzerland); Harzer, T.P.; Dehm, G. [Max-Planck-Institut für Eisenforschung GmbH, 40237 Düsseldorf (Germany)

    2017-07-15

    Metastable Cu–Cr alloy thin films with nominal thickness of 300 nm and composition of Cu{sub 67}Cr{sub 33} (at%) are obtained by co-evaporation using molecular beam epitaxy. The microstructure, chemical phase separation and electronic structure are investigated by transmission electron microscopy (TEM). The thin film adopts the body-centered cubic crystal structure and consists of columnar grains with ~50 nm diameter. Aberration-corrected scanning TEM in combination with energy dispersive X-ray spectroscopy confirms compositional fluctuations within the grains. Cu- and Cr-rich domains with composition of Cu{sub 85}Cr{sub 15} (at%) and Cu{sub 42}Cr{sub 58} (at%) and domain size of 1–5 nm are observed. The alignment of the interface between the Cu- and Cr-rich domains shows a preference for {110}-type habit plane. The electronic structure of the Cu–Cr thin films is investigated by electron energy loss spectroscopy (EELS) and is contrasted to an fcc-Cu reference sample. The experimental EEL spectra are compared to spectra computed by density functional theory. The main differences between bcc-and fcc-Cu are related to differences in van Hove singularities in the electron density of states. In Cu–Cr solid solutions with bcc crystal structure a single peak after the L{sub 3}-edge, corresponding to a van Hove singularity at the N-point of the first Brillouin zone is observed. Spectra computed for pure bcc-Cu and random Cu–Cr solid solutions with 10 at% Cr confirm the experimental observations. The calculated spectrum for a perfect Cu{sub 50}Cr{sub 50} (at%) random structure shows a shift in the van Hove singularity towards higher energy by developing a Cu–Cr d-band that lies between the delocalized d-bands of Cu and Cr. - Highlights: • Compositional fluctuations on the order of 1–5 nm in Cu- and Cr-rich domains are observed. • EELS determines a single van Hove singularity for bcc Cu–Cr solid solutions. • The electronic structure is dominated by d

  4. Design and development of wide energy neutron REM equivalent spectrometer-dosimeters based on polycarbonates and Cr-39

    International Nuclear Information System (INIS)

    Faermann, S.

    1985-03-01

    This work describes a system composed of a Rem response personnel neutron dosemeter, based on boron radiators and a polycarbonate track detector, for monitoring dose equivalents in the energy range 1 eV to 14 MeV, an electrochemical etching system for revealing damage sites in solid state track etch detectors, a reader for magnifying the etched pits and a microprocessor for evaluating the dose equivalents and their uncertainties. The performance and directional dependence of the dosemeter when exposed to monoenergetic and polyenergetic neutron fields in the epithermal and fast energy regions are discussed. Saturation effects in polycarbonate foils are presented and a comparison is made between the response of polycarbonate and CR-39 foils, used as passive detectors in the dosemeter. A new passive miniature fast neutron spectrometer-dosimeter is also described. The device is based on the detection of proton tracks by electrochemical etching of CR-39 foils covered with thin polyethylene layers of different thicknesses. By means of this device it is possible to assess the fast neutron energy spectrum in 10 energy intervals in the energy range 0.5-15 MeV. Dose equivalents can be determined in the dose equivalent range 20 mRem to 8 Rem, approximately (author)

  5. The Microstructures and Energy Dispersive Spectroscopy Analysis of a Hypoeutectoid Steels With 1% Cr

    Directory of Open Access Journals (Sweden)

    Rożniata E.

    2013-12-01

    Full Text Available W artykule zamieszczono wyniki badań mikrostruktury, analizy EDS i twardości stali podeutektoidalnych z 1% Cr imitujących składem chemicznym stale do ulepszania cieplnego. Badania dylatometryczne wykonano przy użyciu dylatometru L78R.I.T.A niemieckiej firmy LlNSElS. Za pomocą dyla- tometru rejestrowano zmiany wydłużenia (Al próbek o wymiarach >p 3X10mm w funkcji temperatury (T. Otrzymane krzywe nagrzewania posłużyły do precyzyjnego wyznaczenia temperatur krytycznych (punktów przełomowych dla badanych stali. Natomiast otrzymane krzywe chłodzenia różniczkowano, co pozwoliło precyzyjnie określić temperatury początków i końców poszczególnych przemian dla wykonania dwóch wykresów CTPc. Analizę składu chemicznego występujących faz w badanych stalach dla różnych szybkości chłodzenia wykonano przy użyciu mikrosondy elektronowej (mikroanalizator rentgenowski. W niniejszej pracy wykorzystano technikę analizy punktowej, liniowej oraz w obszarze o ustalonym polu. Po umieszczeniu próbek z badanych stali w komorze i osiągnięciu odpowiedniej próżni, wyszukano miejsca i dokonano analizy techniką EDS (Energy Dispersive Spectroscopy. Analizy EDS dokonano przy użyciu skaningowego mikroskopu transmisyjnego typu Nova NanoS EM 450. Opracowane wykresy CTPc zgodnie z klasyfikacją Wever’a i Rose’go są typu IV, co oznacza, że przemiany dyfuzyjne są rozdzielone zakresem trwałości przechłodzonego austenitu i mają kształt litery „C". Hartowność badanych stali jest zbliżona, jednak molibden działa zdecydowanie skuteczniej niż nikiel. Molibden zajmuje I-sze miejsce wśród skuteczności pierwiastków stopowych dla stali do niskiego odpuszczania, gdzie „tło" pierwiastków jest słabe. Dla obu badanych stali podeutektoidalnych analiza EDS wykazała wydzielanie się cementy tu stopowego na granicach ziaren. Chrom, jako pierwiastek terrytotwórczy dość silnie dyfunduje do granic ziaren. Widocznie jest to przy

  6. Energy, Vacuum, Gas Fueling, and Security Systems for the Spherical Tokamak MEDUSA-CR

    Science.gov (United States)

    Gonzalez, Jeferson; Soto, Christian; Carvajal, Johan; Ribeiro, Celso

    2013-10-01

    The former spherical tokamak (ST) MEDUSA (Madison EDUcation Small Aspect.ratio tokamak, R security systems for MEDUSA-CR device. The interface with the control and data acquisition systems based on National Instruments (NI) software (LabView) and hardware (on loan to our laboratory via NI-Costa Rica) are also presented. VIE-ITCR, IAEA-CRP contract 17592, National Instruments of Costa Rica.

  7. Study of the V{sup 51} (p,n)Cr{sup 51} reaction and the energy levels in Cr{sup 51}; Etude de la reaction {sup 51}V (p,n){sup 51}Cr et contribution a la spectroscopie de {sup 51}Cr

    Energy Technology Data Exchange (ETDEWEB)

    Cassacnou, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-07-01

    Neutrons and gamma rays from the reaction {sup 51}V(p,n){sup 51}Cr have been studied between 2.3 and 5.1 MeV Energy levels of {sup 51}Cr at 0.75, 1.15, 1.35, 1.47 and 1.56 MeV and unresolved levels at 1.94, 2.4, 2.75 and 2.9 MeV are observed. The gamma ray cascades of the low-lying states of {sup 51}Cr up to 2.5 MeV excitation energy have been completely determined through coincidence measurements. From the cascade ratios and gamma ray yields, excitation functions for the {sup 51}V(p,n){sup 51}Cr reactions, leading to the five lowest levels of {sup 51}Cr have been obtained from reaction threshold to 4.6 MeV. The analysis of cross section fluctuations with good resolution shows they are due to the excitation of unresolved compound nucleus isolated resonances. From the decay scheme and an Hauser-Feshbach calculation of the {sup 51}V(p,n) excitation functions, spin assignments of 3/2{sup -}, or 5/2{sup -} (0.75 MeV), 7/2{sup -} (1.15 MeV), 3/2{sup -} (1.35 MeV), 5/2{sup -} (1.47 MeV) are proposed. (author) [French] La reaction {sup 51}V(p,n){sup 51}Cr a ete etudiee entre 2,3 et 5,1 MeV en detectant les neutrons et le rayonnement gamma de desexcitation des niveaux de {sup 51}Cr a 0,75, 1,15, 1,35, 1,47 et 1,56 MeV et de groupes non resolus de niveaux a 1,94, 2,4, 2,75 et 2,9 MeV. Des mesures de coincidence ont permis de determiner completement les desexcitations en cascade dans {sup 51}Cr jusqu'a 2,5 MeV et d'etablir, a partir des mesures de rayonnement gamma, les fonctions d'excitation des reactions {sup 51}V(p,n){sup 51}Cr formant les cinq premiers niveaux de {sup 51}Cr depuis le seuil jusqu'a 4,6 MeV. L'analyse en bonne resolution des fluctuations observees sur les sections efficaces montrent qu'elles sont dues a des resonances isolees du noyau compose non resolubles dans cette experience. Le schema de desexcitation de {sup 51}Cr et un calcul Hauser-Feshbach des fonctions d'excitation conduisent a proposer les spins suivants: 3/2{sup -} ou 5/2{sup -} pour le niveau

  8. Identification of new fluorescence processes in the UV spectra of cool stars from new energy levels of Fe II and Cr II

    Science.gov (United States)

    Johansson, Sveneric; Carpenter, Kenneth G.

    1988-01-01

    Two fluorescence processes operating in atmospheres of cool stars, symbiotic stars, and the Sun are presented. Two emission lines, at 1347.03 and 1360.17 A, are identified as fluorescence lines of Cr II and Fe II. The lines are due to transitions from highly excited levels, which are populated radiatively by the hydrogen Lyman alpha line due to accidental wavelength coincidences. Three energy levels, one in Cr II and two in Fe II, are reported.

  9. Femtosecond Cr:LiSAF and Cr:LiCAF lasers pumped by tapered diode lasers.

    Science.gov (United States)

    Demirbas, Umit; Schmalz, Michael; Sumpf, Bernd; Erbert, Götz; Petrich, Gale S; Kolodziejski, Leslie A; Fujimoto, James G; Kärtner, Franz X; Leitenstorfer, Alfred

    2011-10-10

    We report compact, low-cost and efficient Cr:Colquiriite lasers that are pumped by high brightness tapered laser diodes. The tapered laser diodes provided 1 to 1.2 W of output power around 675 nm, at an electrical-to-optical conversion efficiency of about 30%. Using a single tapered diode laser as the pump source, we have demonstrated output powers of 500 mW and 410 mW together with slope efficiencies of 47% and 41% from continuous wave (cw) Cr:LiSAF and Cr:LiCAF lasers, respectively. In cw mode-locked operation, sub-100-fs pulse trains with average power between 200 mW and 250 mW were obtained at repetition rates around 100 MHz. Upon pumping the Cr:Colquiriite lasers with two tapered laser diodes (one from each side of the crystal), we have observed scaling of cw powers to 850 mW in Cr:LiSAF and to 650 mW in Cr:LiCAF. From the double side pumped Cr:LiCAF laser, we have also obtained ~220 fs long pulses with 5.4 nJ of pulse energy at 77 MHz repetition rate. These are the highest energy levels reported from Cr:Colquiriite so far at these repetition rates. Our findings indicate that tapered diodes in the red spectral region are likely to become the standard pump source for Cr:Colquiriite lasers in the near future. Moreover, the simplified pumping scheme might facilitate efficient commercialization of Cr:Colquiriite systems, bearing the potential to significantly boost applications of cw and femtosecond lasers in this spectral region (750-1000 nm).

  10. Direct observation of low energy nuclear spin excitations in HoCrO3 by high resolution neutron spectroscopy.

    Science.gov (United States)

    Chatterji, T; Jalarvo, N; Kumar, C M N; Xiao, Y; Brückel, Th

    2013-07-17

    We have investigated low energy nuclear spin excitations in the strongly correlated electron compound HoCrO3. We observe clear inelastic peaks at E = 22.18 ± 0.04 μeV in both energy loss and gain sides. The energy of the inelastic peaks remains constant in the temperature range 1.5-40 K at which they are observed. The intensity of the inelastic peak increases at first with increasing temperature and then decreases at higher temperatures. The temperature dependence of the energy and intensity of the inelastic peaks is very unusual compared to that observed in other Nd, Co, V and also simple Ho compounds. Huge quasielastic scattering appears at higher temperatures presumably due to the fluctuating electronic moments of the Ho ions that get increasingly disordered at higher temperatures. The strong quasielastic scattering may also originate in the first Ho crystal-field excitations at about 1.5 meV.

  11. Energy-dependent etching-related impacts on CR-39 alpha detection efficiency for the Rn-222 and Rn-220 decay chains

    Science.gov (United States)

    Tan, Y.; Yuan, H.; Kearfott, K. J.

    2018-04-01

    CR-39 detectors are widely used to measure environmental levels of Rn-222, Rn-220 and their progeny. Prior research reported the CR-39 detection efficiency for alpha particles from Rn-222, Rn-220 and their progeny under a variety of etching conditions. This paper provides an explanation for interesting observations included in that work, namely that the critical incidence angle decreases with the increasing particle energy and the detection efficiency for 8.78 MeV alpha particles is zero. This paper explains these phenomena from a consideration of the interaction of alpha particles with the CR-39 detectors and the physics of etching dynamics. The proposed theory provides a rationale for an approach to optimizing the etching conditions of CR-39 detector for measuring Rn-222, Rn-220 and their progenies.

  12. Primary CR energy spectrum and mass composition by the data of Tunka-133 array

    Directory of Open Access Journals (Sweden)

    Prosin V.V.

    2015-01-01

    Full Text Available The Cherenkov light array for the registration of extensive air showers (EAS Tunka-133 collected data during 5 winter seasons from 2009 to 2014. The differential energy spectrum of all particles and the dependence of the average maximum depth on the energy in the range of 6 ⋅ 1015–1018 eV measured for 1540 hours of observation are presented.

  13. Vermont Highest Priority Interior Forest Blocks

    Data.gov (United States)

    Vermont Center for Geographic Information — Act 174 requires plans to identify potential areas for the development and siting of renewable energy resources and areas that are unsuitable for siting those...

  14. Structural, morphological, and optical characterizations of Mo, CrN and Mo:CrN sputtered coatings for potential solar selective applications

    Science.gov (United States)

    Ibrahim, Khalil; Mahbubur Rahman, M.; Taha, Hatem; Mohammadpour, Ehsan; Zhou, Zhifeng; Yin, Chun-Yang; Nikoloski, Aleksandar; Jiang, Zhong-Tao

    2018-05-01

    Mo, CrN, and Mo:CrN sputtered coatings synthesized onto silicon Si(100) substrates were investigated as solar selective surfaces and their potential applications in optical devices. These coatings were characterized using XRD, SEM, UV-vis, and FTIR techniques. XRD investigation, showed a change in CrN thin film crystallite characteristic due to Mo doping. Compared to the CrN coating, the Mo:CrN film has a higher lattice parameter and lower grain size of 4.19 nm and 106.18 nm, respectively. FESEM morphology confirmed the decrement in Mo:CrN crystal size due to Mo doping. Optical analysis showed that in the visible range of the solar spectrum, the CrN coatings exhibit the highest solar absorptance of 66% while the lowest thermal emittance value of 5.67 was recorded for the CrN coating doped with Mo. Consequently, the highest solar selectivity of 9.6, and the energy band-gap of 2.88 eV were achieved with the Mo-doped CrN coatings. Various optical coefficients such as optical absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constants, and energy loss functions of these coatings were also estimated from the optical reflectance data recorded in the wavelength range of 190-2300 nm.

  15. Measurement of (n,α) cross-sections for Cr, Fe and Ni at 14 MeV neutron energy

    International Nuclear Information System (INIS)

    Wattecamps, E.; Liskien, H.; Arnotte, F.

    1983-01-01

    Helium production cross-sections for the main constituents of stainless steel (Cr, Fe, Ni) have recently been published for neutron energies between 5 and 10 MeV. The α-particles were detected with a multi-angle telescope and cross-section data relative to the well known n-p scattering cross-section were deduced. Those measurements have been performed now also at 14 MeV. At this energy the background condition had to be improved by changing the neutron collimation, by reducing the sensitive volume of the ΔE-proportional counters, and by replacing remaining low-Z material inside the chamber by tantalum. Listing mode data acquisition is used and α-particle identification is performed by transforming the observed (ΔE,E) signal into a (MZ 2 ,E) signal. The measurements yield the angle-differential cross sections for five fixed angles. Angle-integrated cross-sections are compared with the few results available in literature. (Auth.)

  16. Measurement of excitation yields of low energy prompt γ-ray from proton bombardment of Cr-foils with energies ranging between 1.0 and 3.0 MeV

    International Nuclear Information System (INIS)

    Goncharov, A.

    2014-01-01

    The goal of this work is measurement of differential cross sections for the production of 378 keV γ-rays from the reactions 52 Cr(p,γ1) 53 Mn and 53 Cr(p,nγ1) 53 Mn for proton energies ranging between 1.0 and 3.0 MeV at the laboratory angle of 90° using foils with thickness ∼1.9×10 18 at/cm 2 (∼ 0.23 μm) of nat Cr.

  17. Kinetics of Cr(III) and Cr(VI) removal from water by two floating macrophytes.

    Science.gov (United States)

    Maine, M A; Hadad, H R; Sánchez, G; Caffaratti, S; Pedro, M C

    2016-01-01

    The aim of this work was to compare Cr(III) and Cr(VI) removal kinetics from water by Pistia stratiotes and Salvinia herzogii. The accumulation in plant tissues and the effects of both Cr forms on plant growth were also evaluated. Plants were exposed to 2 and 6 mg L(-1) of Cr(III) or Cr(VI) during 30 days. At the end of the experiment, Cr(VI) removal percentages were significantly lower than those obtained for Cr(III) for both macrophytes. Cr(III) removal kinetics involved a fast and a slow component. The fast component was primarily responsible for Cr(III) removal while Cr(VI) removal kinetics involved only a slow process. Cr accumulated principally in the roots. In the Cr(VI) treatments a higher translocation from roots to aerial parts than in Cr(III) treatments was observed. Both macrophytes demonstrated a high ability to remove Cr(III) but not Cr(VI). Cr(III) inhibited the growth at the highest studied concentration of both macrophytes while Cr(VI) caused senescence. These results have important implications in the use of constructed wetlands for secondary industrial wastewater treatment. Common primary treatments of effluents containing Cr(VI) consists in its reduction to Cr(III). Cr(III) concentrations in these effluents are normally below the highest studied concentrations in this work.

  18. Energy Harvesting Characteristics from Water Flow by Piezoelectric Energy Harvester Device Using Cr/Nb Doped Pb(Zr,Ti)O3 Bimorph Cantilever

    Science.gov (United States)

    Kim, Kyoung-Bum; Kim, Chang Il; Jeong, Young Hun; Cho, Jeong-Ho; Paik, Jong-Hoo; Nahm, Sahn; Lim, Jong Bong; Seong, Tae-Hyeon

    2013-10-01

    A water flow energy harvester, which can convert water flow energy to electric energy, was fabricated for its application to rivers. This harvester can generate power from the bending and releasing motion of piezoelectric bimorph cantilevers. A Pb(Zr0.54Ti0.46)O3 + 0.2 wt % Cr2O3 + 1.0 wt % Nb2O5 (PZT-CN) thick film and a 250-µm-thick stainless steel were used as a bimorph cantilever. The electrical impedance matching was achieved across a resistive load of 1 kΩ. Four bimorph cantilevers can generate power from 5 to 105 rpm. The output powers were steadily increased by increasing the rpm. The maximum output power was 68 mW by 105 rpm. It was found that the water flow energy harvester can generate 58 mW by a flow velocity of (2 m/s) from the stream with the four bimorph cantilevers.

  19. Energy band structure of Cr by the Slater-Koster interpolation scheme

    International Nuclear Information System (INIS)

    Seifu, D.; Mikusik, P.

    1986-04-01

    The matrix elements of the Hamiltonian between nine localized wave-functions in tight-binding formalism are derived. The symmetry adapted wave-functions and the secular equations are formed by the group theory method for high symmetry points in the Brillouin zone. A set of interaction integrals is chosen on physical ground and fitted via the Slater-Koster interpolation scheme to the abinito band structure of chromium calculated by the Green function method. Then the energy band structure of chromium is interpolated and extrapolated in the Brillouin zone. (author)

  20. CORRELATION OF THE FERMI ENERGY OF Ni, Cr, Mn WITH THE ELECTROCATALYTIC ACTIVITY OF THE TRIPLE ALLOYS ON THE BASE OF THESE METALS

    Directory of Open Access Journals (Sweden)

    A. D. Andreyanov

    2016-04-01

    Full Text Available It was established the dependence of the electrocatalytic activity of alloys Ni-Cr-Mn at the variable contents of copper with values of Fermy energy of their components. Electrocatalytic activity of alloys was estimated by density of the current, determined by the method of suspended half-element. For Fermi energy calculation of various metals Sommerfeld model, in which distribution of electrons by speed is described by Fermi-Dirac statistic was used.

  1. Charge resolution of a Hungarian brand CR-39(MA-ND) detector exposed to a 84Kr beam of energy 0.45A GeV

    International Nuclear Information System (INIS)

    Bhattacharyya, D.P.; Basu, B.; Pal, P.; Mukherjee, S.C.; Ganguly, A.K.; Hunyady, I.

    1990-01-01

    The Hungarian brand CR-39(MA-ND) plastic has been irradiated with a 84 Kr ion beam of energy 0.45A GeV and etched for four different etching times, viz. 4, 6, 8 and 12 h. The estimated charge resolution of a CR-39(MA-ND) detector for registering the nuclei 32 ≤ Z ≤ 36 was found to be 0.18e which is close to our previous observation of the response with a CR-39(DOP) Pershore made plate exposed to a 1.88A GeV 56 Fe beam at the Lawrence Berkeley Laboratory's Bevalac. It was found that the estimated etch rate ratio V T /V G is independent of etching time. The cone length and minor axis of the etch pits has been found to increase with etching time. (orig.)

  2. Microstructure and mechanical properties of Ti-Zr-Cr biomedical alloys.

    Science.gov (United States)

    Wang, Pan; Feng, Yan; Liu, Fengchao; Wu, Lihong; Guan, Shaokang

    2015-06-01

    The Ti-15Zr-xCr (0≤x≤10, wt.%) alloys were investigated to develop new biomedical materials. It was found that the phase constitutions and mechanical properties strongly depended on the Cr content. The Ti-15Zr alloy was comprised of α' phase and a small fraction of β phase was detected with adding 1wt.% Cr. With addition of 5wt.% or more, the β phase was completely retained. In addition, the ω phase was detected in the Ti-15Zr-5Cr alloy and Ti-15Zr-7Cr alloy which exhibited the highest compressive Young's modulus and the lowest ductility. On the other hand, all the Ti-15Zr-xCr alloys without ω phase exhibited high microhardness, high yield strength and superior ductility. Furthermore, the elastic energy of Ti-15Zr-10Cr alloy (5.89MJ/m(3)) with only β phase and that of Ti-15Zr-3Cr alloy (4.04MJ/m(3)) with α' phase and small fraction of β phase was higher than the elastic energy of c.p. Ti (1.25MJ/m(3)). This study demonstrated that Ti-15Zr-3Cr alloy and Ti-15Zr-10Cr alloy with superior mechanical properties are potential materials for biomedical applications. Copyright © 2015. Published by Elsevier B.V.

  3. Spatial distribution of the X- and γ- rays induced energy deposition on semi-insulating GaAs:Cr based pixel radiation detector

    International Nuclear Information System (INIS)

    Meneses Gonzalez, Annie; Leyva Fabelo, Antonio; Pinnera Hernandez, Ibrahin; Cruz Inclan, Carlos M.; Abreu Alfonso, Yamiel; Chelkov, Georgy; Zhemchugov, Alexey

    2015-01-01

    Radiation detectors based on Cr compensated GaAs are characterized by high resistivity and good electron transport properties. These characteristics, its high atomic number and good radiation hardness, make GaAs:Cr a promising semiconductor detector within a wide photon energy range. The excellent imaging performance of these detectors for medical and other several applications are already reported in the literature. In this study, the spatial distributions of photon radiation energy deposition on a GaAs:Cr pixel detector with the real device dimensions (900 μm thick, pixels of 45x45 μm 2 and pitch of 55 μm) are presented. The charge carrier distribution profiles generated by the incident photons was additionally determined and discussed. Using the calculated weighting potential for the detector was possible to estimate the percent of charge carriers that shall contribute to the signal generated in the device electrodes. All the calculations were made for the typical photon energies of 241 Am and the energy corresponding to the K α1 characteristic lines of Mo. The MCNPX code system and ARCHIMEDES program were used for mathematical modeling of radiation transport in matter and for semiconductor device simulations respectively. (Author)

  4. Estimativa das necessidades energéticas em pacientes com doença renal crônica Estimating the energy requirement of chronic kidney disease patients

    Directory of Open Access Journals (Sweden)

    Juliana Cordeiro Dias Rodrigues

    2013-02-01

    Full Text Available Estabelecer as necessidades energéticas de pacientes com doença renal crônica é importante para que se possam tratar os distúrbios nutricionais encontrados nessa população. Segundo os guias de condutas voltados ao cuidado nutricional de pacientes com essa doença, a recomendação energética pode variar entre 30 e 40kcal/kg/dia. Contudo, trabalhos que avaliaram os componentes do gasto energético nos pacientes com doença renal crônica sugerem que as necessidades energéticas dessa população podem diferir do valor recomendado acima, a depender da condição clínica (presença de comorbidades, da modalidade de tratamento empregado e do nível de atividade física. Dessa forma, o presente trabalho tem como objetivo fazer uma revisão dos estudos sobre o gasto energético de pacientes com doença renal crônica, com o intuito de abordar as seguintes questões: (1 as atuais recomendações de energia para pacientes com doença renal crônica estão adequadas? (2 qual equação de predição poderia ser empregada para estimar as necessidades energéticas desse grupo de pacientes? Assim, esta revisão busca auxiliar o nutricionista ao estimar as necessidades energéticas de pacientes com doença renal crônica.Estimating the energy requirement of patients with chronic kidney disease is highly important for treating the nutritional disorders often seen in this population. According to the specific guidelines for patients with chronic kidney disease, the currently recommended daily energy intake varies from 30 to 40kcal/kg/day. However, studies that investigated energy expenditure components of patients with chronic kidney disease suggested that the energy requirement may differ from the one proposed earlier, depending on overall clinical condition (i.e. presence of comorbidities, treatment modality and level of physical activity. With this perspective in mind, the present study aims to review the studies assessing energy expenditure

  5. Structural, electrical, and dielectric properties of Cr doped ZnO thin films: Role of Cr concentration

    Energy Technology Data Exchange (ETDEWEB)

    Gürbüz, Osman, E-mail: osgurbuz@yildiz.edu.tr; Okutan, Mustafa

    2016-11-30

    Highlights: • Magnetic material of Cr and semiconductor material of ZnO were grown by the magnetron sputtering co-sputter technique. • Perfect single crystalline structures were grown. • DC and AC conductivity with dielectric properties as a function of frequency (f = 5Hz–13 MHz) at room temperature were measured and compared. • Cr doped ZnO can be used in microwave, sensor and optoelectronic devices as the electrical conductivity increases while dielectric constant decreases with the Cr content. - Abstract: An undoped zinc oxide (ZnO) and different concentrations of chromium (Cr) doped ZnO Cr{sub x}ZnO{sub 1−x} (x = 3.74, 5.67, 8.10, 11.88, and 15.96) thin films were prepared using a magnetron sputtering technique at room temperature. These films were characterized by X-ray diffraction (XRD), High resolution scanning electron microscope (HR-SEM), and Energy dispersive X-ray spectrometry (EDS). XRD patterns of all the films showed that the films possess crystalline structure with preferred orientation along the (100) crystal plane. The average crystallite size obtained was found to be between 95 and 83 nm which was beneficial in high intensity recording peak. Both crystal quality and crystallite sizes decrease with increasing Cr concentration. The crystal and grain sizes of the all film were investigated using SEM analysis. The surface morphology that is grain size changes with increase Cr concentration and small grains coalesce together to form larger grains for the Cr{sub 11.88}ZnO and Cr{sub 15.96}ZnO samples. Impedance spectroscopy studies were carried out in the frequencies ranging from 5 Hz to 13 MHz at room temperature. The undoped ZnO film had the highest dielectric value, while dielectric values of other films decreased as doping concentrations increased. Besides, the dielectric constants decreased whereas the loss tangents increased with increasing Cr content. This was considered to be related to the reduction of grain size as Cr content in Zn

  6. Track detection on the cells exposed to high Linear Energy Transfer heavy-ions by Cr-39 plastic and terminal deoxynucleotidyl transferase(Td T)

    International Nuclear Information System (INIS)

    Mehnati, P.; Keshtkar, A.; Mesbahi, A.; Sasaki, H.

    2006-01-01

    The fatal effect of ionizing radiation on cells depends on Linear Energy Transfer level. The distribution of ionizing radiation is sparse and homogeneous for low Linear Energy Transfer radiations such as X or y, but it is dense and concentrated for high Linear Energy Transfer radiation such as heavy-ions radiation. Materials and Methods: Chinese hamster ovary cells (CHO-K1) were exposed to 4 Gy Fe-ion 2000 keV/μm. The Cr-39 is a special and sensitive plastic used to verify exact position of heavy-ions traversal. Terminal deoxynucleotidyl transferase is an enzyme labeled with [3 H ] d ATP for detection of cellular DNA damage by autoradiography assay. Results: The track of heavy ions traversals presented by pit size was almost similar for all different doses of radiation. No pits to show the track of traversal were found in 20% of the cell nuclei of the irradiation. Apparently these fractions of cells wave not hit by heavy ions. Conclusion: This study indicated the possible usefulness of both the Cr-39 plastics and DNA labeling with Terminal deoxynucleotidyl transferase method for evaluating the biological effect of heavy-ions in comparison with low Linear Energy Transfer ionizing radiation

  7. SU-F-T-299: An Experimental 2D Computed Radiography (CR) Dosimeter for IMRT. Are In-Field Measurements Affected by the Low Energy Photon Overresponse?

    Energy Technology Data Exchange (ETDEWEB)

    Crijns, W [University Hospital Leuven, Leuven (Belgium); Vandenbroucke, D; Leblans, P [Agfa Healthcare N.V., Mortsel (Belgium); Depuydt, T

    2016-06-15

    Purpose: Computed Radiography (CR) dosimetry could offer film dosimetry resolution and flexibility but with reusability and instantaneous processing. For an experimental CR-plate, designed for radiotherapy (Zeff=18), CR’s typical out-of-field over-response to low energy photons was previously reduced to 8%. The present work assesses the impact of the residual over-response when open-fields are combined or when intensity modulated fields are used. Methods: Agfa Healthcare’s experimental CRplate was scanned and erased 4min after each irradiation using a flying-spot CR-15-X-engine based reader, which was adapted for radiotherapy dosimetry. A CR-plate specific calibration and uniformity correction was used.For open-fields two abutting half beams (5×10cm{sup 2}) captured out-offield and in-field doses in a single image. Additionally, both half beams were measured individually as well as a 3×18Gy open-field SBRT-lung treatment. For intensity modulated fields standard test patterns (Chair and Pyramid) and a clinical 5×5Gy rectal VMAT plan were captured. All measurements were compared to the corresponding dose calculations. Results: For open-fields the out-of-field overdose was clearly larger than the in-field overdose (10% vs. 4%). The sum of the individual measurements corresponded well with the combined measurement (dose difference, ΔD<−2.2%). The SBRT case had no overdose in the high dose region; ΔD=−5.6%±3.3%, the deviation was attributed to CR-fading effects (−0.3%/min) which were not corrected for.Compared to open-fields, intensity modulated deliveries had a further increased over-response out-offield (ΔD=+58% to +125% [Chair] +43% [Pyramid]), due to the increased amount of low energy photons for IMRT. However, this effect was not measured in-field where even decreased dose signals were observed (ΔD=−0.3% to +2.25% [Chair], −4.5% to −0.1% [Pyramid]). The rectal VMAT treatment had a dose difference +2.4%±6.0%. The in-field deviations were

  8. Effect of cold deformation on latent energy value and high-temperature mechanical properties of 12Cr18Ni10Ti steel

    International Nuclear Information System (INIS)

    Maksimkin, O.P.; Shiganakov, Sh.B.; Gusev, M.N.

    1997-01-01

    Energetic and magnetic characteristics and also the high-temperature mechanical properties depending on the preliminary cold deformation of 12Cr18Ni10Ti steel are presented. It is shown that the value of storage energy in the steel has being grown with increase of the deformation. The rate of its growth has been increased after beginning of martensitic γ→α'- transformation when value of comparative storage energy at first decreased and then has been stay practically constant. Level of mechanical properties of the steel at 1073 K has been determined not only by value of cold deformation but and structural reconstruction corresponding to deformations 35-45% and accompanying with α'-phase martensite formation and change of energy accumulating rate. Preliminary cold deformation (40-60 %) does not improve high- temperature plasticity of steel samples implanted by helium. refs. 7, figs. 2

  9. Pr{sup 3+1}S{sub 0}->Cr{sup 3+} energy transfer and ESR investigation in Pr{sup 3+} and Cr{sup 3+} activated SrAl{sub 12}O{sub 19} quantum cutting phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Nie Zhaogang [BK21 Physics Program and Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Lim, Ki-Soo, E-mail: kslim@chungbuk.ac.k [BK21 Physics Program and Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Zhang Jiahua [Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Wang Xiaojun [Department of Physics, Georgia Southern University, Statesboro, GA 30460 (United States)

    2009-08-15

    With the help of the Dexter's theory, the energy transfer mechanism from Pr{sup 3+1}S{sub 0} to Cr{sup 3+} is investigated theoretically in SrAl{sub 12}O{sub 19}:Pr{sup 3+}, Cr{sup 3+} quantum cutting phosphors. The electron spin resonance (ESR) spectra of Pr{sup 3+} and Cr{sup 3+}-doped SrAl{sub 12}O{sub 19} with magnetoplumbite structure have been studied. The Cr{sup 3+} ion is found to enter the Al4(4f) site, which is very close to the Sr(2d) site replaced by the Pr{sup 3+} ions in the host. The theoretical results indicate that the efficient Pr{sup 3+1}S{sub 0}->Cr{sup 3+} energy transfer can only take place in the intermediate mirror planes, in which for the nearest and next-nearest Pr{sup 3+}-Cr{sup 3+} pairs, both dipole-dipole and dipole-quadrupole interactions can play their parts in the transfer. Finally, an overview is given about the research on the energy transfer from Pr{sup 3+1}S{sub 0} to codopants in their co-doped materials.

  10. Kyle Cranmer receives the highest recognition from the US government

    CERN Multimedia

    Allen Mincer

    Kyle Cranmer with Clay Sell, Deputy Secretary of EnergyKyle Cranmer, who has worked on ATLAS as a graduate student at the University of Wisconsin-Madison, a Goldhaber Fellow at Brookhaven National Laboratory, and, most recently, an Assistant Professor at New York University, has been awarded a Presidential Early Career Award for Scientists and Engineers (PECASE). As described at the United States Department of Energy web page: "The PECASE Awards are intended to recognize some of the finest scientists and engineers who, while early in their research careers, show exceptional potential for leadership at the frontiers of scientific knowledge during the twenty-first century...The PECASE Award is the highest honor bestowed by the U.S. government on outstanding scientists and engineers beginning their independent careers." Kyle's work on ATLAS focuses on tools and strategies for data analysis, triggering, and searches for the Higgs.At the awards ceremony, which took place on Thursday Nov. 1st in Washington, D.C.,...

  11. Er,Cr:YSGG Laser Energy Delivery: Pulse and Power Effects on Enamel Surface and Erosive Resistance.

    Science.gov (United States)

    de Oliveira, Renan Mota; de Souza, Vinicius Matsuzaki; Esteves, Camila Machado; de Oliveira Lima-Arsati, Ynara Bosco; Cassoni, Alessandra; Rodrigues, José Augusto; Brugnera Junior, Aldo

    2017-11-01

    High power lasers have been suggested as a useful tool for dental caries and erosion prevention due to the increase of enamel acid resistance. to evaluate the effect of Er,Cr:YSGG (erbium,chromium:yttrium, scandium, gallium, garnet) laser irradiation pulse frequency and power on enamel surface and acid erosion resistance. By combining pulse frequency (5-75 Hz) and power settings (0.10-1.00 W), 20 irradiated groups and one nonirradiated control group were tested. A total of 63 bovine enamel blocks (n = 3/group) were prepared for surface hardness and roughness evaluation, performed in three phases: baseline, after irradiation, and after erosive challenge. Enamel blocks were irradiated with Er,Cr:YSGG laser with MZ8 tip (iPlus; Waterlase, Biolase, CA) for 30 sec according to experimental group and submitted. Erosive challenge consisted of four cycles alternating immersion in 0.01 M HCl (5 mL/mm 2 ; 2 min; at 37°C) and immersion in artificial saliva for 3 h. Analysis of variance (three-way ANOVA), Tukey's test, and Pearson correlation were performed for the statistical analysis (p hardness. After erosive challenge, 5 and 75 W groups showed increase in surface hardness; 0.25, 0.5, 0.75, and 1 W groups showed minor alterations in surface roughness. the irradiation of Er,Cr:YSGG laser with different parameters of power and pulse frequency settings may alter enamel surface and erosive resistance differently. Pulse frequency of 30 Hz and power of 0.50 W was considered the best parameter to prevent enamel acid erosion.

  12. Effect of Cr3C2 content on the microstructure and properties of Mo2NiB2-based cermets

    International Nuclear Information System (INIS)

    Xie, Lang; Li, XiaoBo; Zhang, Dan; Yang, ChengMing; Yin, FuCheng; Xiangtan Univ., Hunan; Xiangtan Univ., Hunan; Xiao, YiFeng

    2015-01-01

    Four series of Mo 2 NiB 2 -based cermets with Cr 3 C 2 addition of between 0 and 7.5 wt.% in 2.5 wt.% increments were studied by means of scanning electron microscopy, energy dispersive X-ray analysis and X-ray diffractometry. The transverse rupture strength and hardness were also measured. It was found that Cr 3 C 2 completely dissolved in Mo 2 NiB 2 -based cermets. Cr 3 C 2 addition improved the wettability of the Ni binder phase on the Mo 2 NiB 2 hard phase, which resulted in a decrease in the porosity and an increase in the phase uniformity. The cermets with 2.5 wt.% Cr 3 C 2 content showed relatively fine grains and almost full density. A high Cr 3 C 2 content resulted in the formation of M 6 C (M = Mo, Cr, Ni) phase. In addition, energy dispersive X-ray spectroscopy results showed that the content of Mo in the binder decreased with increasing Cr 3 C 2 content. The cermets with 2.5 wt.% Cr 3 C 2 addition exhibited the highest transverse rupture strength of 2210 MPa, whereas the cermets without Cr 3 C 2 addition exhibited the highest hardness.

  13. RIGScan CR: RIGScan CR49.

    Science.gov (United States)

    2004-01-01

    RIGScan CR49, a 125I-labelled CR monoclonal antibody directed against the tumour-associated antigen TAG-72, is undergoing development with Neoprobe for the intraoperative detection of metastatic colorectal cancer. The Neoprobe's proprietary RIGS (radioimmunoguided surgery) technology combines an injectable radiolabelled cancer-targeting agent and hand-held radiation detection probe that emits an audible tone when located tissue has accumulated a significant amount of the radioactive agent. Neoprobe's RIGS technology also includes a patented surgical method providing surgeons with real-time information to locate tumour deposits that can not be detected by other conventional methods. The RIGS technology has been evaluated in late clinical studies for the detection of adenocarcinomas including primary colorectal, gastrointestinal, breast, ovarian, pancreatic, prostate and neuroendocrine/endocrine. Neoprobe signed an option agreement for its first-generation RIGScan compound, RIGScan CR, with OncoSurg Inc. (formerly NuRigs Ltd). The second-generation humanised RIGScan CR agent was also optionally licensed to OncoSurg Inc. In 1997, Neoprobe filed for approval with the US FDA and the EMEA for RIGScan CR for the intraoperative detection of metastatic colorectal cancer. Both regulatory agencies have requested additional clinical data. On 19 April 2004, Neoprobe announced that it had met with the US FDA to discuss its position on submitting additional clinical information in response to the FDA's questions regarding the Biologic Licence Application (BLA) for RIGScan CR49. The company provided the FDA with new information related to a survival differential for patients whose colorectal cancer was evaluated with RIGScan CR49. The information was not available at the time of the BLA's submission in 1997. The agency indicated that it would consider accepting survival data from one of the two phase III trials, NEO2-14, but not from another trial NEO2-13, as supportive data for a

  14. Advanced FeCrAl ODS steels for high-temperature structural applications in energy generation systems

    OpenAIRE

    Pimentel, G.; Capdevila, Carlos; Bartolomé, Mª. J.; Chao, Jesús; Serrano, M.; García-Junceda, A.; Campos, M.; Torralba Castelló, José Manuel; Aldazabal, J.

    2012-01-01

    Technologies and means for developing biomass plant with higher energy conversion efficiencies are essential in order to implement the commitment to renewable biomass energy generation. Advanced, indirect Combined Cycle Gas Turbine (CCGT) systems offer overall biomass energy conversion efficiencies of 45 % and above, compared with the 35 % efficiency of conventional biomass steam plant. However to attain this efficiency in CCGT operation it will be necessary to develop a heat exchanger capabl...

  15. Structural, thermal, and photoacoustic study of nanocrystalline Cr{sub 3}Ge produced by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Prates, P. B.; Maliska, A. M.; Ferreira, A. S. [Departamento de Engenharia Mecânica, Universidade Federal de Santa Catarina, Campus Universitário Trindade, S/N, C.P. 476, 88040-900 Florianópolis, Santa Catarina (Brazil); Poffo, C. M. [Universidade Federal de Santa Catarina, Campus de Araranguá, 88900-000 Araranguá, Santa Catarina (Brazil); Borges, Z. V. [Departamento de Física, Universidade Federal do Amazonas, 3000 Japiim, 69077-000 Manaus, Amazonas (Brazil); Lima, J. C. de, E-mail: fsc1jcd@fisica.ufsc.br [Departamento de Física, Universidade Federal de Santa Catarina, Campus Universitário Trindade, S/N, C.P. 476, 88040-900 Florianópolis, Santa Catarina (Brazil); Biasi, R. S. de [Seção de Engenharia Mecânica e de Materiais, Instituto Militar de Engenharia, 22290-270 Rio de Janeiro (Brazil)

    2015-10-21

    A thermodynamic analysis of the Cr-Ge system suggested that it was possible to produce a nanostructured Cr{sub 3}Ge phase by mechanical alloying. The same analysis showed that, due to low activation energies, Cr-poor crystalline and/or amorphous alloy could also be formed. In fact, when the experiment was performed, Cr{sub 11}Ge{sub 19} and amorphous phases were present for small milling times. For milling times larger than 15 h these additional phases decomposed and only the nanostructured Cr{sub 3}Ge phase remained up to the highest milling time used (32 h). From the differential scanning calorimetry measurements, the Avrami exponent n was obtained, indicating that the nucleation and growth of the nanostructured Cr{sub 3}Ge phase may be restricted to one or two dimensions, where the Cr and Ge atoms diffuse along the surface and grain boundaries. In addition, contributions from three-dimensional diffusion with a constant nucleation rate may be present. The thermal diffusivity of the nanostructured Cr{sub 3}Ge phase was determined by photoacoustic absorption spectroscopy measurements.

  16. Effect of free Cr content on corrosion behavior of 3Cr steels in a CO2 environment

    Science.gov (United States)

    Li, Wei; Xu, Lining; Qiao, Lijie; Li, Jinxu

    2017-12-01

    The corrosion behavior of 3Cr steels with three microstructures (martensite, bainite, combined ferrite and pearlite) in simulated oil field formation water with a CO2 partial pressure of 0.8 MPa was investigated. The relationships between Cr concentrations in corrosion scales and corrosion rates were studied. The precipitated phases that contained Cr were observed in steels of different microstructures, and free Cr content levels were compared. The results showed that steel with the martensite microstructure had the highest free Cr content, and thus had the highest corrosion resistance. The free Cr content of bainite steel was lower than that of martensite steel, and the corrosion rate of bainite steel was higher than that of martensite steel. Because large masses of Cr were combined in ferrite and pearlite steel, the corrosion rates of ferrite and pearlite steel were the highest. Free Cr content in steel affects its corrosion behavior greatly.

  17. Electron propagator calculations on the ionization energies of CrH -, MnH - and FeH -

    Science.gov (United States)

    Lin, Jyh-Shing; Ortiz, J. V.

    1990-08-01

    Electron propagator calculations with unrestricted Hartree-Fock reference states yield the ionization energies of the title anions. Spin contamination in the anionic reference state is small, enabling the use of second-and third-order self-energies in the Dyson equation. Feynman-Dyson amplitudes for these ionizations are essentially identical to canonical spin-orbitals. For most of the final states, these consist of an antibonding combination of an sp metal hybrid, polarized away from the hydrogen, and hydroegen s functions. In one case, the Feynman-Dyson amplitude consists of nonbonding d functions. Calculated ionization energies are within 0.5 eV of experiment.

  18. Cortex Matures Faster in Youths With Highest IQ

    Science.gov (United States)

    ... NIH Cortex Matures Faster in Youths With Highest IQ Past Issues / Summer 2006 Table of Contents For ... on. Photo: Getty image (StockDisc) Youths with superior IQ are distinguished by how fast the thinking part ...

  19. Which Kids Are at Highest Risk for Suicide?

    Science.gov (United States)

    ... Share Which Kids are at Highest Risk for Suicide? Page Content Article Body No child is immune, ... who have lost a friend or relative to suicide. Studies show that a considerable number of youth ...

  20. Dissipation and accumulation of energy during plastic deformation of Armco -iron and 12Cr18Ni10Ti stainless steel irradiated by neutrons

    International Nuclear Information System (INIS)

    Toktogulova, D.; Maksimkin, O.; Gusev, M.; Garner, F.

    2007-01-01

    Full text of publication follows: Much attention is currently being paid in the fusion materials community to modeling of radiation damage and its consequences in structural alloys on mechanical properties. Such activities are best guided with experimental data on the fundamental microstructural and thermodynamic processes involved. This report addresses such fundamental concerns. During plastic deformation of metals some fraction of the externally-applied mechanical energy is converted into heat and is partially accumulated in the form of crystal lattice defects. The thermal release arises from gliding dislocations, their various interactions, their annihilation etc. With respect to irradiated material, one might expect additional heat release caused by interactions of dislocation and radiation-induced defects. To explore this possibility flat mini-tensile specimens of Armco-iron and 12Cr18Ni10Ti stainless steel, both in the annealed condition, were irradiated in the range 2x10 18 to 1.3x10 20 n/cm 2 (E>0.1 MeV) in the WWR-K reactor at T≤350 K. Mechanical tests of both irradiated and non-irradiated specimens were conducted at room temperature in a facility that was a combination of a Calvet calorimeter and a micro-tensile device. This allows simultaneous measurement of mechanical properties and thermodynamic parameters such as deformation work, dissipated heat and latent energy during deformation. The authors derived the kinetics of changes in thermodynamic characteristics versus the deformation level. As the neutron fluence rises, the material's capability to accumulate energy appears to be declining. For example, 12Cr18Ni10Ti irradiated to 1.3x10 20 n/cm 2 did not show any energy accumulation under deformation. In Armco-iron at 1.4x10 19 n/cm 2 the heat release considerably exceeded the deformation work value. The authors assume that such effects might be related with annihilation of point defects and their complexes introduced during irradiation. To test this

  1. X-ray attenuation coefficient measurements for photon energies 4.508-13.375 keV in Cu, Cr and their compounds and the validity of the mixture rule

    International Nuclear Information System (INIS)

    Turgut, Ue.; Simsek, Oe.; Bueyuekkasap, E.; Ertugrul, M.

    2004-01-01

    To investigate the validity of the mixture rule which is used to compute the mass attenuation coefficients in compounds, the total mass attenuation coefficients for Cu, Cr elements and Cu 2 O, CuC 2 O 4 , CuCl 2 ·2H 2 O, Cu(C 2 H 3 O 2 ) 2 ·H 2 O, Cr 2 O 3 , Cr(NO 3 ) 3 , Cr 2 (SO 4 ) 3 ·H 2 O, Cr 3 (CH 3 CO 7 )(OH) 2 compounds were measured at photon energies between 4.508 and 13.375 keV by using the secondary excitation method. Ti, Mn, Fe, Ni, Zn, Ge, As, Rb elements were used as secondary exciters. 59.5 keV gamma rays emitted from an 241 Am annular source were used to excite the secondary exciters and Kα (K-L 3 , L 2 ) rays emitted from the secondary exciter were counted by a Si(Li) detector with a resolution of 160 eV at 5.9 keV. Our measurements indicate that the mixture rule is not a suitable method for the computation of mass attenuation coefficients of compounds especially at an energy that is near the absorption edge. Obtained values were compared with theoretical values

  2. Characteristics of latent damage trails due to high energy 208Pb and 238U ions in CR-39 and muscovite mica

    International Nuclear Information System (INIS)

    Chohan, A.S.; Akhtar, S.M.

    1988-01-01

    Experiments have been performed to study the characteristics of latent damage trails produced by (a) 17.14 MeV/nucleon- 208 Pb ions in mica and CR-39 track detectors and (b) 13.7 MeV/nucleon- 238 U in CR-39 track detectors. The parameters studied include (a) V t , average etching velocity along the track, (b) thermal stability of the latent damage trails, (c) the total etchable ranges, and (d) V g the general etching velocity of CR-39 track detectors previously annealed at different temperatures. It has been observed that the latent damage trails in CR-39 are greatly affected at temperatures around 200 0 C in CR-39 track detectors. The general etching velocity of a CR-39 detector has been found to increase with increasing annealing temperatures. (author)

  3. Distribution of chromium species in a Cr-polluted soil: presence of Cr(III) in glomalin related protein fraction.

    Science.gov (United States)

    Gil-Cardeza, María L; Ferri, Alejandro; Cornejo, Pablo; Gomez, Elena

    2014-09-15

    The accumulation of Cr in soil could be highly toxic to human health; therefore Cr soil distribution was studied in rhizosphere soils from Ricinus communis and Conium maculatum and bare soil (BS) from an industrial and urban area in Argentina. Total Cr, Cr(VI) and Cr(III) concentrations were determined in 3 soil fractions: total, extractable and associated to total-glomalin-related protein (T-GRSP). BS had the highest total Cr and total Cr(VI) concentrations. Total Cr(VI) concentration from both rhizosphere soils did not differ from the allowed value for residential area in Argentina (8 μg Cr(VI) g(-1) soil), while total Cr(VI) in BS was 1.8 times higher. Total Cr concentration in all the soils was higher than the allowed value (250 μg Cr g(-1) soil). Extractable and associated to T-GRSP Cr(VI) concentrations were below the detection limit. Cr(III) bound to T-GRSP was the highest in the BS. These findings are in agreement with a long term effect of glomalin in sequestrating Cr. In both plant species, total Cr was higher in root than in shoot and both species presented arbuscular mycorrhizal fungi (AMF). As far as we know, this is the first study that reports the presence of Cr in T-GRSP fraction of soil organic matter. These findings suggest that Cr mycorrhizostabilization could be a predominant mechanism used by R. communis and C. maculatum to diminish Cr soil concentration. Nevertheless, further research is needed to clarify the contribution of native AMF isolated from R. communis and C. maculatum rhizosphere to the Cr phytoremediation process. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Lung Cancer Screening May Benefit Those at Highest Risk

    Science.gov (United States)

    People at the highest risk for lung cancer, based on a risk model, may be more likely to benefit from screening with low-dose CT, a new analysis suggests. The study authors believe the findings may better define who should undergo lung cancer screening, as this Cancer Currents blog post explains.

  5. Highest weight representations of the quantum algebra Uh(gl∞)

    International Nuclear Information System (INIS)

    Palev, T.D.; Stoilova, N.I.

    1997-04-01

    A class of highest weight irreducible representations of the quantum algebra U h (gl-∞) is constructed. Within each module a basis is introduced and the transformation relations of the basis under the action of the Chevalley generators are explicitly written. (author). 16 refs

  6. Exploring the cultural dimensions of the right to the highest ...

    African Journals Online (AJOL)

    The right to enjoying the highest attainable standard of health is incorporated in many international and regional human rights instruments. This right contains both freedoms and entitlements, including the freedom to control one's own health and body and the right to an accessible system of health care, goods and services.

  7. Liquidus projection of the Nb-Cr-Al system near the Al3(Nb,Cr) + Cr(Al,Nb) eutectic region

    International Nuclear Information System (INIS)

    Souza, S.A.; Ferrandini, P.L.; Nunes, C.A.; Coelho, A.A.; Caram, R.

    2006-01-01

    The system Nb-Cr-Al was investigated in the region near the Al 3 (Nb,Cr) + Cr(Al,Nb) eutectic and the liquidus projection of that region was determined based on the microstructural characterization of arc melted alloys. The characterization utilized scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), differential thermal analysis (DTA) and X-ray diffraction (XRD). The results allowed one to determine three primary solidification liquidus surfaces ((Cr,Al) 2 Nb, Cr(Al,Nb) and Al 3 (Nb,Cr)), that are originated from the binary systems Cr-Nb, Cr-Al and Al-Nb. It is proposed the occurrence of the invariant reaction L + (Cr,Al) 2 Nb ↔ Al 3 (Nb,Cr) + Cr(Al,Nb) and of a point of minimum, which involves a three phase reaction, L ↔ Al 3 (Nb,Cr) + Cr(Al,Nb). All alloys studied showed formation of the Al 3 (Nb,Cr) + Cr(Al,Nb) eutectic as the last solidification step with Al(Nb)Cr 2 precipitating from Cr(Al,Nb)

  8. Advanced FeCrAl ODS steels for high-temperature structural applications in energy generation systems

    Directory of Open Access Journals (Sweden)

    Pimentel, G.

    2012-08-01

    Full Text Available Technologies and means for developing biomass plant with higher energy conversion efficiencies are essential in order to implement the commitment to renewable biomass energy generation. Advanced, indirect Combined Cycle Gas Turbine (CCGT systems offer overall biomass energy conversion efficiencies of 45 % and above, compared with the 35 % efficiency of conventional biomass steam plant. However to attain this efficiency in CCGT operation it will be necessary to develop a heat exchanger capable of gas operating temperatures and pressures of around 1100 °C and 15-30 bar, respectively, for entry heating the gas turbine working fluid. ODS ferritic steels is the kind of advance material to deal with this challenge, however work to optimize the coarse grain microstructure to improve creep hoop strength needs to be done. In this sense, this paper reports the recrystallisation behaviour of PM 2000 oxide dispersion strengthened ferritic alloy which was cold deformed after hot-rolling and extrusion. The results can be interpreted if it is assumed that anything which makes the microstructure heterogeneous, stimulates recrystallisation. In this sense, larger strain gradients lead to more refined and more isotropic grain structures. The combination of these results with finite element modeling are used to interpret the role of residual shear stresses on the development of recrystallized grain structure.

    Las tecnologías y medios para desarrollar plantas de biomasa con alta eficiencia en la conversión de energía son esenciales para asentar la biomasa como una fuente de energía renovable. Los sistemas de turbinas de gas de ciclo combinado (CCGT permiten elevar la eficiencia de las plantas de biomasa del 35 % actual al 45 %. Sin embargo, para conseguir estos niveles de eficiencia en la conversión de energía, el intercambiador de calor de la caldera debe trabajar en condiciones extremas de temperatura (por encima de 1100 °C y presión (en torno a 15

  9. Do optimally ripe blackberries contain the highest levels of metabolites?

    Science.gov (United States)

    Mikulic-Petkovsek, Maja; Koron, Darinka; Zorenc, Zala; Veberic, Robert

    2017-01-15

    Five blackberry cultivars were selected for the study ('Chester Thornless', 'Cacanska Bestrna', 'Loch Ness', 'Smoothstem' and 'Thornfree') and harvested at three different maturity stages (under-, optimal- and over-ripe). Optimally ripe and over-ripe blackberries contained significantly higher levels of total sugars compared to under-ripe fruit. 'Loch Ness' cultivar was characterized by 2.2-2.6-fold higher levels of total sugars than other cultivars and consequently, the highest sugar/acids ratio. 'Chester Thornless' stands out as the cultivar with the highest level of vitamin C in under-ripe (125.87mgkg(-1)) and optimally mature fruit (127.66mgkg(-1)). Maturity stage significantly affected the accumulation of phenolic compounds. The content of total anthocyanins increased for 43% at optimal maturity stage and cinnamic acid derivatives for 57% compared to under-ripe fruit. Over-ripe blackberries were distinguished by the highest content of total phenolics (1251-2115mg GAE kg(-1) FW) and greatest FRAP values (25.9-43.2mM TE kg(-1) FW). Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Enhancement of the Corrosion Resistance of 304 Stainless Steel by Cr–N and Cr(N,O Coatings

    Directory of Open Access Journals (Sweden)

    Mihaela Dinu

    2018-04-01

    Full Text Available Chromium nitride and oxynitride coatings were deposited as monolayers ((Cr–N, Cr(N,O and bilayers (Cr–N/Cr(N,O, Cr(N,O/Cr–N on 304 steel substrates by reactive cathodic arc method. The coatings were characterised by X-ray diffraction (XRD, scanning electron microscopy (SEM, energy dispersive X-ray spectrometry (EDS, surface profilometry, and scratch tester. The anticorrosive properties of the coatings were assessed by electrochemical tests in 0.10 M NaCl + 1.96 M H2O2, carried out at 24 °C. Cr2N, CrN, and Cr(N,O phases were identified in the coatings by grazing incidence X-ray diffraction (GI-XRD measurements. The measured adhesion values ranged from 19 N to 35 N, the highest value being obtained for the bilayer with Cr(N,O on top. Electrochemical tests showed that Cr(N,O presence in both mono- and bilayered coatings determined the lowest damage in corrosive solution, as compared to the Cr–N coatings. This improvement was ascribed to the more compact structure, lower coatings porosity, and smoother surface.

  11. Structural, optical and ferromagnetic properties of Cr doped TiO2 nanoparticles

    International Nuclear Information System (INIS)

    Choudhury, Biswajit; Choudhury, Amarjyoti

    2013-01-01

    Graphical abstract: Doping of Cr 3+ distorts the lattice of TiO 2 , generate oxygen vacancies and create d-band states in the mid band gap of TiO 2 . Incorporation of Cr 3+ also imparts magnetism in non-magnetic TiO 2 by undergoing coupling with the neighboring oxygen vacancies. -- Highlights: • Incorporation of Cr 3+ increases the concentration of oxygen vacancies in TiO 2 nanoparticles. • Doped TiO 2 nanoparticles contain absorption peaks corresponding to d–d transition of Cr 3+ into TiO 2 . • Pure and doped TiO 2 nanoparticles contain emission peaks related to oxygen vacancies. • Pure TiO 2 shows diamagnetism while Cr doped TiO 2 shows ferromagnetism. • The ferromagnetism is due to the interaction of Cr 3+ ions via oxygen vacancies. -- Abstract: Cr doped TiO 2 nanoparticles are prepared with three different concentrations of chromium, 1.5%, 3.0% and 4.5 mol% respectively. Doping decreases the crystallinity and increases the width of the X-ray diffraction peak. The Raman active E g peak of TiO 2 nanoparticles become asymmetric and shifted to higher energy on doping of 4.5% chromium. Electron paramagnetic resonance spectra reveal the presence of Cr 3+ in the host TiO 2 matrix. The absorption spectra of Cr doped TiO 2 nanoparticles contain absorption peaks corresponding to d–d transition of Cr 3+ in octahedral coordination. Most of the visible emission peaks are due to the electrons trapped in the oxygen vacancy centers. Undoped TiO 2 nanoparticles show diamagnetism at room temperature while all chromium doped samples show ferromagnetism. The magnetization of the doped samples increases at 1.5% and 3.0% and decreases at 4.5%. The ferromagnetism arises owing to the interaction of the neighboring Cr 3+ ions via oxygen vacancies. The decrease of magnetization at the highest doping is possibly due to the antiferromagnetic interactions of Cr 3+ pairs or due to Cr 3+ -O 2− -Cr 3+ superexchange interaction in the lattice

  12. The fifty highest cited papers in anterior cruciate ligament injury.

    Science.gov (United States)

    Vielgut, Ines; Dauwe, Jan; Leithner, Andreas; Holzer, Lukas A

    2017-07-01

    The anterior cruciate ligament (ACL) is one of the most common injured knee ligaments and at the same time, one of the most frequent injuries seen in the sport orthopaedic practice. Due to the clinical relevance of ACL injuries, numerous papers focussing on this topic including biomechanical-, basic science-, clinical- or animal studies, were published. The purpose of this study was to determine the most frequently cited scientific articles which address this subject, establish a ranking of the 50 highest cited papers and analyse them according to their characteristics. The 50 highest cited articles related to Anterior Cruciate Ligament Injury were searched in Thomson ISI Web of Science® by the use of defined search terms. All types of scientific papers with reference to our topic were ranked according to the absolute number of citations and analyzed for the following characteristics: journal title, year of publication, number of citations, citation density, geographic origin, article type and level of evidence. The 50 highest cited articles had up to 1624 citations. The top ten papers on this topic were cited 600 times at least. Most papers were published in the American Journal of Sports Medicine. The publication years spanned from 1941 to 2007, with the 1990s and 2000s accounting for half of the articles (n = 25). Seven countries contributed to the top 50 list, with the USA having by far the most contribution (n = 40). The majority of articles could be attributed to the category "Clinical Science & Outcome". Most of them represent a high level of evidence. Scientific articles in the field of ACL injury are highly cited. The majority of these articles are clinical studies that have a high level of evidence. Although most of the articles were published between 1990 and 2007, the highest cited articles in absolute and relative numbers were published in the early 1980s. These articles contain well established scoring- or classification systems. The

  13. A Highest Order Hypothesis Compatibility Test for Monocular SLAM

    OpenAIRE

    Edmundo Guerra; Rodrigo Munguia; Yolanda Bolea; Antoni Grau

    2013-01-01

    Simultaneous Location and Mapping (SLAM) is a key problem to solve in order to build truly autonomous mobile robots. SLAM with a unique camera, or monocular SLAM, is probably one of the most complex SLAM variants, based entirely on a bearing-only sensor working over six DOF. The monocular SLAM method developed in this work is based on the Delayed Inverse-Depth (DI-D) Feature Initialization, with the contribution of a new data association batch validation technique, the Highest Order Hyp...

  14. First-Principles Calculations for Chemical Reaction between Sodium Diethyldithiocarbamate and Transition-Metal (Cr) atom to Produce Cr(DDC)3 and Cr(DDC)2ODDC

    Science.gov (United States)

    Setiyanto, Henry; Muhida, Rifki; Kishi, Tomoya; Rempillo, Ofelia; Rahman, Mahmudur; Dipojono, Hermawan Kresno; Di\\ {n}o, Wilson Agerico; Matsumoto, Shigeno; Kasai, Hideaki

    2006-10-01

    We investigate the chemical reaction between a Cr transition-metal atom and sodium diethyldithiocarbamate (NaDDC), a complexing agent used to detect and extract Cr in human blood samples. Using density-functional-theory-based calculations, we determine their stable structures of Cr(DDC)2ODDC and Cr(DDC)3 complexes and obtain their dissociation energies. We found dissociation energies of -10.66 and -3.24 eV for Cr(DDC)2ODDC and Cr(DDC)3 complexes, respectively. Hence, on the basis of dissociation energies, we have verified that the reaction of NaDDC with Cr produces Cr(DDC)2ODDC as a major product.

  15. Thermodynamic analysis of Cr(VI) extraction using TOPO impregnated membranes

    Energy Technology Data Exchange (ETDEWEB)

    Praveen, Prashant; Loh, Kai-Chee, E-mail: chelohkc@nus.edu.sg

    2016-08-15

    Highlights: • Cr(VI) extraction by extractant impregnated membranes (EIM) was investigated. • EIM exhibited high extraction efficiency, mass transfer rate and stability. • Mass transfer mechanism was proposed based on kinetics and equilibrium data. • Uptake of Cr(VI) by EIMs was endothermic and spontaneous. • Cr(VI) extraction by EIMs was dominated by physical interactions. - Abstract: Solid/liquid extraction of Cr(VI) was accomplished using trioctylphosphine oxide impregnated polypropylene hollow fiber membranes. Extraction of 100–500 mg/L Cr(VI) by the extractant impregnated membranes (EIM) was characterized by high uptake rate and capacity, and equilibrium was attained within 45 min of contact. Extraction equilibrium was pH-dependent (at an optimal pH 2), whereas stripping using 0.2 M sodium hydroxide yielded the highest recovery of 98% within 60 min. The distribution coefficient was independent of initial Cr(VI) concentration, and the linear distribution equilibrium isotherm could be modeled using Freundlich isotherm. The mass transfer kinetics of Cr(VI) was examined using pseudo-second-order and intraparticle diffusion models and a mass transfer mechanism was deduced. The distribution coefficient increased with temperature, which indicated endothermic nature of the reaction. Enthalpy and entropy change during Cr(VI) extraction were positive and varied in the range of 37–49 kJ/mol and 114–155 J/mol, respectively. The free energy change was negative, confirming the feasibility and spontaneity of the mass transfer process. Results obtained suggest that EIMs are efficient and sustainable for extraction of Cr(VI) from wastewater.

  16. Corrosion and Mechanical Properties of Al-5 At. Pct Cr Produced by Cryomilling and Subsequent Consolidation at Various Temperatures

    Science.gov (United States)

    Esquivel, J.; Darling, K. A.; Murdoch, H. A.; Gupta, R. K.

    2018-04-01

    An Al-5 at. pct Cr alloy was produced by high-energy ball milling at liquid nitrogen temperature followed by consolidation using equal-channel axial extrusion at 200 °C, 300 °C and 450 °C. The microstructure and corrosion response were compared with a cast alloy of the same composition. Rather than the intermetallics expected by the phase diagram and seen in the cast alloy, consolidated HEBM alloys exhibited extended solid solubility of Cr in the aluminum matrix in addition to a finely dispersed Cr-rich phase. This led to improvement in the corrosion behavior as investigated via potentiodynamic polarization and constant immersion tests in NaCl solution. Hardness and tensile tests were performed to evaluate the mechanical properties. The highest consolidation temperature (450 °C) contributed to significant grain growth and Cr diffusion, lessening the beneficial effects of processing with HEBM.

  17. Influence of irradiation with energy-rich particles on the hardness of the Fe-Cr alloy; Einfluss der Bestrahlung mit energiereichen Teilchen auf die Haerte von Fe-Cr-Legierungen

    Energy Technology Data Exchange (ETDEWEB)

    Heintze, Cornelia

    2013-01-14

    Ferritic/martensitic and oxide dispersion strengthened ferritic/martensitic steels are candidate structural materials for components exposed to high neutron fluxes in future nuclear applications like fusion and generation IV fission reactors. The ductilebrittle transition and its shift to higher temperatures which is predominantly caused by irradiation hardening are main concerns for these materials. In the present work, the irradiation behaviour of binary Fe-Cr model alloys, which represent a simplified model for ferritic/martensitic steels, is studied. To this end irradiation with iron ions is used in order to simulate the neutron-induced damage. Due to the limited penetration depth characterization methods suitable for thin layers have to be applied. In the present case, nanohardness testing and transmission electron microscopy (TEM) are employed. The results, including the irradiation-induced hardness change of the layer as a function of chromium content, fluence and irradiation temperature and, for selected cases, quantitative TEM analyses, were exploited to identify irradiation-induced dislocation loops as one source of irradiation hardening. Additional results of small-angle neutron scattering experiments on neutron-irradiated specimens of the same alloys show that nm-scaled α'-phase precipitates also significantly contribute to the irradiation-induced hardness increase. An Orowan model is used to estimate the obstacle strengths posed to dislocation glide by these lattice defects. The topic is stepwise extended to more complex situations with respect to the irradiation conditions and the materials. Considering simultaneous and sequential irradiations with iron- and helium-ions it is shown that the effect of helium on irradiation hardening depends on the chronological order of the irradiations and that the simultaneous introduction of helium in fusion-relevant concentrations amplifies irradiation hardening based on a synergistic effect. There is no

  18. Robert Aymar receives one of the highest Finnish distinctions

    CERN Multimedia

    2008-01-01

    On 9 December 2008 Robert Aymar, CERN Director-General, was awarded the decoration of Commander, first class, of the Order of the Lion of Finland by the President of the Republic of Finland. This decoration, one of the highest of Finland, was presented in a ceremony by the Ambassador Hannu Himanen, Permanent Representative of Finland to the UN and other international organisations in Geneva. Robert Aymar was honoured for his service to CERN, the LHC, his role in the cooperation between Finland and CERN, as well as his contribution to science in general. In his speech the ambassador underlined CERN’s efforts in the field of education, mentioning the High school teachers programme.

  19. Structure, magnetism, and electron-transport properties of Mn2CrGa-based nanomaterials

    Directory of Open Access Journals (Sweden)

    Wenyong Zhang

    2016-05-01

    Full Text Available Mn2CrGa in the disordered cubic structure has been synthesized using rapid quenching and subsequent annealing. The cubic phase transforms to a stable tetragonal phase when a fraction of Cr or Ga is replaced by Pt or Al, respectively. All samples are ferrimagnetic with high Curie temperatures (Tc; Mn2CrGa exhibits the highest Tc of about 813 K. The tetragonal samples have appreciable values of magnetocrystalline anisotropy energy, which leads to an increase in coercivity (Hc that approaches about 10 kOe in the Pt-doped sample. The Hc linearly increases with a decrease of temperature, concomitant with the anisotropy change with temperature. All samples are metallic and show negative magnetoresistance with room-temperature resistivities on the order of 1 mΩcm. The magnetic properties including high Tc and low magnetic moment suggest that these tetragonal materials have potential for spin-transfer-torque-based devices.

  20. Compatibility of Firm Positioning Strategy and Website Content: Highest

    Directory of Open Access Journals (Sweden)

    Evla MUTLU KESİCİ

    2017-07-01

    Full Text Available Corporate websites are essential platforms through which firms introduce their goods and services on B2B and B2C level, express financial information for the stakeholders and share corporate values, purposes and activities. Due to its facilities, websites take part in firm positioning strategy. Accordingly this study aims to understand the innovation oriented positioning through corporate websites. The method applied in this study has been adapted from the 2QCV2Q Model developed by Mich and Franch (2000 to evaluate websites and top 30 firms with the highest Research and Development expenditures listed in Turkishtime (2015 have been analyzed. Within this context, this study presents a revised and updated method for the assessments of websites through positioning strategy framework. Findings indicate no direct relationship between website evaluation and R&D expenditure, though some common weaknesses have been put forward, such as information about management of the firms. Besides, publicly traded firms are recognized to facilitate websites more efficiently than non-publicly traded firms. Study contribute to both academia and practitioners as putting forward a new approach for 2QCV2Q Model and indicating the similarities and differences among the corporate websites through positioning perspective.

  1. Estimation of the center frequency of the highest modulation filter.

    Science.gov (United States)

    Moore, Brian C J; Füllgrabe, Christian; Sek, Aleksander

    2009-02-01

    For high-frequency sinusoidal carriers, the threshold for detecting sinusoidal amplitude modulation increases when the signal modulation frequency increases above about 120 Hz. Using the concept of a modulation filter bank, this effect might be explained by (1) a decreasing sensitivity or greater internal noise for modulation filters with center frequencies above 120 Hz; and (2) a limited span of center frequencies of the modulation filters, the top filter being tuned to about 120 Hz. The second possibility was tested by measuring modulation masking in forward masking using an 8 kHz sinusoidal carrier. The signal modulation frequency was 80, 120, or 180 Hz and the masker modulation frequencies covered a range above and below each signal frequency. Four highly trained listeners were tested. For the 80-Hz signal, the signal threshold was usually maximal when the masker frequency equaled the signal frequency. For the 180-Hz signal, the signal threshold was maximal when the masker frequency was below the signal frequency. For the 120-Hz signal, two listeners showed the former pattern, and two showed the latter pattern. The results support the idea that the highest modulation filter has a center frequency in the range 100-120 Hz.

  2. Recreational fishing selectively captures individuals with the highest fitness potential.

    Science.gov (United States)

    Sutter, David A H; Suski, Cory D; Philipp, David P; Klefoth, Thomas; Wahl, David H; Kersten, Petra; Cooke, Steven J; Arlinghaus, Robert

    2012-12-18

    Fisheries-induced evolution and its impact on the productivity of exploited fish stocks remains a highly contested research topic in applied fish evolution and fisheries science. Although many quantitative models assume that larger, more fecund fish are preferentially removed by fishing, there is no empirical evidence describing the relationship between vulnerability to capture and individual reproductive fitness in the wild. Using males from two lines of largemouth bass (Micropterus salmoides) selectively bred over three generations for either high (HV) or low (LV) vulnerability to angling as a model system, we show that the trait "vulnerability to angling" positively correlates with aggression, intensity of parental care, and reproductive fitness. The difference in reproductive fitness between HV and LV fish was particularly evident among larger males, which are also the preferred mating partners of females. Our study constitutes experimental evidence that recreational angling selectively captures individuals with the highest potential for reproductive fitness. Our study further suggests that selective removal of the fittest individuals likely occurs in many fisheries that target species engaged in parental care. As a result, depending on the ecological context, angling-induced selection may have negative consequences for recruitment within wild populations of largemouth bass and possibly other exploited species in which behavioral patterns that determine fitness, such as aggression or parental care, also affect their vulnerability to fishing gear.

  3. A Highest Order Hypothesis Compatibility Test for Monocular SLAM

    Directory of Open Access Journals (Sweden)

    Edmundo Guerra

    2013-08-01

    Full Text Available Simultaneous Location and Mapping (SLAM is a key problem to solve in order to build truly autonomous mobile robots. SLAM with a unique camera, or monocular SLAM, is probably one of the most complex SLAM variants, based entirely on a bearing-only sensor working over six DOF. The monocular SLAM method developed in this work is based on the Delayed Inverse-Depth (DI-D Feature Initialization, with the contribution of a new data association batch validation technique, the Highest Order Hypothesis Compatibility Test, HOHCT. The Delayed Inverse-Depth technique is used to initialize new features in the system and defines a single hypothesis for the initial depth of features with the use of a stochastic technique of triangulation. The introduced HOHCT method is based on the evaluation of statistically compatible hypotheses and a search algorithm designed to exploit the strengths of the Delayed Inverse-Depth technique to achieve good performance results. This work presents the HOHCT with a detailed formulation of the monocular DI-D SLAM problem. The performance of the proposed HOHCT is validated with experimental results, in both indoor and outdoor environments, while its costs are compared with other popular approaches.

  4. Angle and temperature dependence of the magnetocrystalline anisotropy energy and the microscopic magnetic moments of the ferromagnetic semi-metal CrO{sub 2}; Winkel- und Temperaturabhaengigkeit der magnetokristallinen Anisotropieenergie und der mikroskopischen magnetischen Momente des ferromagnetischen Halbmetalls CrO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Gold, S.

    2005-07-01

    The aim of this work was to examine, by use of XMCD-effect and additional measurements with SQUID-magnetometer, spin moments and hysteresis loops, but also to clarify the intrinsic properties like magnetocrystalline anisotropy, magnetic dipole term, and the nearly quenched orbital moment. The XMCD-measurements were done at the Cr L{sub 2,3}- and the O K-edge. The results for CrO{sub 2} show a strong dependence of the orbital, the sum of spin moment and magnetic dipole term, and the magnetocrystalline anisotropy energy from the angle between rutile a- and c-axis. Even more than the complete orbital moment, two separable and different spectral features show strong alterations of the different orbital moments. In a second part of this work the temperature dependence was investigated. The aim was to clarify the origin of the orbital moment, dipole term, and MAE in dependence of the spin moment and compare the results to different theoretical models. The extracted orbital moments and the magnetic dipole term show the same temperature dependence as the spin moment. In the following a dependence of the squared measured spin moment could be found for the MAE. For the first time the magnetic dipole term could be identified as the reason of the magnetocrystalline anisotropy energy. A strong Cr-O hybridisation was found, which shows in a similar structure and temperature dependence of the orbital moments for Cr L{sub 2,3} and the XMCD effect at O-K edge. (orig.)

  5. The roles of polycarboxylates in Cr(VI)/sulfite reaction system: Involvement of reactive oxygen species and intramolecular electron transfer

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Bo, E-mail: bjiang86upc@163.com [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Qingdao 266580, Shandong (China); School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033 (China); Wang, Xianli; Liu, Yukun [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Qingdao 266580, Shandong (China); Wang, Zhaohui [College of Environmental Science and Engineering, Donghua University, Shanghai 201620 (China); Southern Cross GeoScience, Southern Cross University, Lismore, NSW 2480 (Australia); Zheng, Jingtang, E-mail: jtzheng03@163.com [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Qingdao 266580, Shandong (China); Wu, Mingbo, E-mail: wumb@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Qingdao 266580, Shandong (China)

    2016-03-05

    Highlights: • The formations of SO{sub 4}·{sup −} and OH·, involve in Cr(VI) reduction induced by S(IV). • Affinity of polycarboxylate to Cr(VI) accelerates Cr(VI) reduction rate. • Polycarboxylates can act as electron donors for Cr(VI) reduction retrenching S(IV). • Only oxalate can enhance the formations of SO{sub 4}·{sup −} and OH· in Cr(VI)/S(IV) system. - Abstract: In this study, the effects of polycarboxylates on both Cr(VI) reduction and S(IV) consumption in Cr(VI)/S(IV) system was investigated in acidic solution. Under aerobic condition, the productions of reactive oxygen species (ROS), i.e., SO{sub 4}·{sup −} and OH·, have been confirmed in S(IV) reducing Cr(VI) process by using electron spin resonance and fluorescence spectrum techniques, leading to the excess consumption of S(IV). However, when polycarboxylates (oxalic, citric, malic and tartaric acid) were present in Cr(VI)/S(IV) system, the affinity of polycarboxylates to CrSO{sub 6}{sup 2−} can greatly promote the reduction of Cr(VI) via expanding the coordination of Cr(VI) species from tetrahedron to hexahedron. Besides, as alternatives to S(IV), these polycarboxylates can also act as electron donors for Cr(VI) reduction via intramolecular electron transfer reaction, which is dependent on the energies of the highest occupied molecular orbital of these polycarboxylates. Notably, the variant electron donating capacity of these polycarboxylates resulted in different yield of ROS and therefore the oxidation efficiencies of other pollutants, e.g., rhodamine B and As(III). Generally, this study does not only shed light on the mechanism of S(IV) reducing Cr(VI) process mediated by polycarboxylates, but also provides an escalated, cost-effective and green strategy for the remediation of Cr(VI) using sulfite as a reductant.

  6. Absolute measurement of the cross sections of neutron radiative capture for 23Na, Cr, 55Mn, Fe, Ni, 103Rh, Ta, 197Au and 238U in the 10-600keV energy range

    International Nuclear Information System (INIS)

    Le Rigoleur, Claude; Arnaud, Andre; Taste, Jean.

    1976-10-01

    The total energy weighting technique has been applied to measuring absolute neutron capture cross sections for 23 Na, Cr, 55 Mn, Fe, Ni, 103 Rh, Ta, 197 Au, 238 U in the 10-600keV energy range. A non hydrogeneous liquid scintillator was used to detect the gamma from the cascade. The neutron flux was measured with a 10 B INa(Tl) detector or a 6 Li glass scintillator of well known efficiency. The fast time-of-flight technique was used with on line digital computer data processing [fr

  7. Modeling on Fe-Cr microstructure: evolution with Cr content

    International Nuclear Information System (INIS)

    Diaz Arroyo, D.; Perlado, J.M.; Hernandez-Mayoral, M.; Caturla, M.J.; Victoria, M.

    2007-01-01

    Full text of publication follows: The minimum energy configuration of interstitials in the Fe-Cr system, which is the base for the low activation steels being developed in the European fusion reactor materials community, is determined by magnetism. Magnetism plays also a role in the atomic configurations found with increasing Cr content. Results will be presented from a program in which the microstructure evolution produced after heavy ion irradiation in the range from room temperature to 80 K is studied as a function of the Cr content in alloys produced under well controlled conditions, i.e. from high purity elements and with adequate heat treatment. It is expected that these measurements will serve as matrix for model validation. The first step in such modeling sequence is being performed by modeling the evolution of displacement cascades in Fe using the Dudarev -Derlet and Mendeleev potentials for Fe and the Caro potential for Fe-Cr. It is of particular interest to study the evolution of high-energy cascades, where an attempt will be made to clarify the role of the evolution of sub-cascades. Kinetic Monte Carlo (kMC) techniques will be used then to simulate the defect evolution. A new parallel kMC code is being implemented for this purpose. (authors)

  8. Is CR39 worth the effort?

    International Nuclear Information System (INIS)

    Griffith, R.V.

    1987-01-01

    CR39 proton sensitive track detectors were greeted by the radiation protection community at the end of the last decade as a major breakthrough for personnel neutron dosimetry. A number of laboratories eagerly began research on application of CR39 to their dosimetry needs. However, in the last two or three years the enthusiasm has subsided, and many health physicists have stopped working with the material. The number of participants using CR39 in the Oak Ridge National Laboratory Personnel Intercomparison Studies dropped from six in 1985 to three in 1986. On a national level, the Federal Republic of Germany with researchers active in CR39 research recently adopted an albedo system as their national standard. In contrast, the United States Department of Energy (DOE) is supporting development of a CR39 based combination dosimeter to meet Department wide dosimetry needs. The English National Radiological Protection Board (NRPB) now features the use of CR39 in the NRPB PADC(CR39). There has obviously been a range of experiences with CR39 in the dosimetry community. Why has this been the case, and what is the proper role for CR39 in personnel neutron dosimetry. 12 refs., 2 figs., 1 tab

  9. Correlation between bulk- and surface chemistry of Cr-tanned leather and the release of Cr(III) and Cr(VI)

    Energy Technology Data Exchange (ETDEWEB)

    Hedberg, Yolanda S., E-mail: yolanda@kth.se [KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry, Division of Surface and Corrosion Science, SE-10044 Stockholm (Sweden); Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-17177 Stockholm (Sweden); Lidén, Carola, E-mail: carola.liden@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-17177 Stockholm (Sweden); Odnevall Wallinder, Inger, E-mail: ingero@kth.se [KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry, Division of Surface and Corrosion Science, SE-10044 Stockholm (Sweden)

    2014-09-15

    Graphical abstract: - Highlights: • Released reducing/complexing leather-specific species can reduce released Cr(VI). • No co-released species enable the formation of Cr(VI) in solution. • The major Cr species released from leather in phosphate buffer was Cr(III) (>82%). • No Cr(VI) was released into artificial sweat. - Abstract: About 1–3% of the adult general population in Europe is allergic to chromium (Cr). The assessment of the potential release of Cr(III) and Cr(VI) from leather is hence important from a human health and environmental risk perspective. The Cr(VI) content in leather was recently restricted in the European Union. The aim of this study was to assess possible correlations between the bulk and surface chemistry of leather, released Cr(III) and Cr(VI), and capacities of co-released leather specific species to reduce and complex released Cr. Four differently tanned leathers were characterized by scanning electron microscopy with energy dispersive spectroscopy, X-ray photoelectron spectroscopy, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, and the diphenylcarbazide colorimetric method. Their characteristics were compared with results on Cr(III) and Cr(VI) release into artificial sweat (ASW, pH < 6.5) and phosphate buffer (PB, pH 7.5–8.0), measured by means of spectrophotometry and atomic absorption spectroscopy. Co-released leather-specific species were shown to reduce Cr(VI), both in ASW and in PB. Their reduction capacities correlated with findings of the surface content of Cr and of released Cr. Leather samples without this capacity, and with less aromatic surface groups visible by ATR-FTIR, revealed Cr(VI) both at the surface and in solution (PB)

  10. Correlation between bulk- and surface chemistry of Cr-tanned leather and the release of Cr(III) and Cr(VI).

    Science.gov (United States)

    Hedberg, Yolanda S; Lidén, Carola; Odnevall Wallinder, Inger

    2014-09-15

    About 1-3% of the adult general population in Europe is allergic to chromium (Cr). The assessment of the potential release of Cr(III) and Cr(VI) from leather is hence important from a human health and environmental risk perspective. The Cr(VI) content in leather was recently restricted in the European Union. The aim of this study was to assess possible correlations between the bulk and surface chemistry of leather, released Cr(III) and Cr(VI), and capacities of co-released leather specific species to reduce and complex released Cr. Four differently tanned leathers were characterized by scanning electron microscopy with energy dispersive spectroscopy, X-ray photoelectron spectroscopy, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, and the diphenylcarbazide colorimetric method. Their characteristics were compared with results on Cr(III) and Cr(VI) release into artificial sweat (ASW, pHleather-specific species were shown to reduce Cr(VI), both in ASW and in PB. Their reduction capacities correlated with findings of the surface content of Cr and of released Cr. Leather samples without this capacity, and with less aromatic surface groups visible by ATR-FTIR, revealed Cr(VI) both at the surface and in solution (PB). Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  11. Cr/alpha-Cr2O3 monodispersed spherical core-shell particles based solar absorbers

    CSIR Research Space (South Africa)

    Khamlich, S

    2011-07-01

    Full Text Available as reported. The coated Cr/alpha-Cr2O3 spherical particles on rough copper substrates by a simple self-assembly-like method were characterized by scanning electron microscopy, energy dispersive spectrometry, Raman spectroscopy, and diffuse reflectance UV...

  12. Microstructural evolution in modified 9Cr-1Mo ferritic/martensitic steel irradiated with mixed high-energy proton and neutron spectra at low temperatures

    International Nuclear Information System (INIS)

    Sencer, B.H.; Garner, F.A.; Gelles, D.S.; Bond, G.M.; Maloy, S.A.

    2002-01-01

    Modified 9Cr-1Mo ferritic/martensitic steel was exposed at 32-57 deg. C to a mixed proton/neutron particle flux and spectrum at the Los Alamos Neutron Science Center. The microstructure of unirradiated 9Cr-1Mo consists of laths, dislocations and carbides. Examination of electron diffraction patterns obtained from extraction replicas of unirradiated 9Cr-1Mo revealed that the precipitate microstructure was primarily dominated by M 23 C 6 carbides. The post-irradiation microstructure contained black-spot damage in addition to precipitates and dislocations. Examination of electron diffraction patterns revealed diffuse rings from M 23 C 6 carbides, indicating amorphization and/or nanocrystallinity. Crystalline MC carbides were also found. No cavity formation was found although a significant amount of helium and hydrogen generation had been generated. TEM-EDS examination of extraction replicas for carbides from unirradiated and irradiated samples did not show any detectable changes in composition of either M 23 C 6 or MC carbides. There was also no evident change in carbide size. Lattice images of M 23 C 6 carbides revealed an amorphous microstructure following irradiation, but MC carbides were still crystalline

  13. The stored energy in processed Cu-0.4 wt.%Cr-0.12 wt.%Zr-0.02 wt.%Si-0.05 wt.%Mg

    International Nuclear Information System (INIS)

    Li, X.F.; Dong, A.P.; Wang, L.T.; Yu, Z.; Meng, L.

    2011-01-01

    Research highlights: → The crystal orientation in processed Cu-0.4 wt.%Cr-0.12 wt.%Zr-0.02 wt.%Si-0.05 wt.%Mg is deviating from the as-cast specimens and microstrain of the alloy is gradually increasing as the draw ratio rising before η ≤ 6.7. → The dynamic recovery has taken place as 6.7 texture is formed with the draw ratio rising. Meanwhile, the stored energy also increases with the draw ratio rising and a peak is reached with draw ratio of 6.7. The release of stored energy is primarily due to the decrease of dislocation density. The flow stress estimated from the stored energy has a similar variation trend with the measured data with a stress difference ∼20 to 120 MPa. The main strengthening effect is attributed to dislocation mechanism.

  14. Migration of Cr-vacancy clusters and interstitial Cr in α-Fe using the dimer method

    International Nuclear Information System (INIS)

    Chen, D.; Gao, F.; Hu, S. Y.; Sun, X.; Heinisch, H. L.; Henager, C. H.; Khaleel, M. A.; Hu, W. Y.; Terentyev, D.

    2010-01-01

    The migration mechanisms and the corresponding activation energies of Cr-vacancy (Cr-V) clusters and Cr interstitials in α-Fe have been investigated using the dimer and the nudged elastic-band methods. Dimer searches are employed to find the possible transition states of these defects and the lowest-energy paths are used to determine the energy barriers for migration. A substitutional Cr atom can migrate to a nearest-neighbor vacancy through an energy barrier of 0.56 eV but this simple mechanism alone is unlikely to lead to the long-distance migration of Cr unless there is a supersaturated concentration of vacancies in the system. The Cr-vacancy clusters can lead to long-distance migration of a Cr atom that is accomplished by Fe and Cr atoms successively jumping to nearest-neighbor vacancy positions, defined as a self-vacancy-assisted migration mechanism, with the migration energies ranging from 0.64 to 0.89 eV. In addition, a mixed Cr-Fe dumbbell interstitial can easily migrate through Fe lattices, with the migration energy barrier of 0.17, which is lower than that of the Fe-Fe interstitial. The on-site rotation of the Cr-Fe interstitial and Cr atom hopping from one site to another are believed to comprise the dominant migration mechanism. The calculated binding energies of Cr-V clusters are strongly dependent on the size of clusters and the concentration of Cr atoms in clusters.

  15. Experimental Investigation of Hadron Collisions at the Highest Center-of-Mass Energies

    Energy Technology Data Exchange (ETDEWEB)

    Marc, Baarmand [Florida Institute of Technology; Hohlmann, Marcus [Florida Institute of Technology

    2012-05-31

    In this report, we summarize the research in physics of elementary particles conducted by the Florida Tech DOE supported group at the CMS experiment at CERN, during the last 3-year cycle under this grant.

  16. Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

    Czech Academy of Sciences Publication Activity Database

    Abreu, P.; Aglietta, M.; Ahn, E.J.; Boháčová, Martina; Chudoba, Jiří; Kárová, Tatiana; Mandát, Dušan; Nečesal, Petr; Nožka, Libor; Nyklíček, M.; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovancová, Jaroslava; Schovánek, Petr; Šmída, Radomír; Trávníček, Petr

    2010-01-01

    Roč. 34, č. 5 (2010), s. 314-326 ISSN 0927-6505 R&D Projects: GA MŠk(CZ) 1M06002; GA MŠk(CZ) LA08016; GA AV ČR KJB100100904; GA MŠk LC527; GA AV ČR KJB300100801 Institutional research plan: CEZ:AV0Z10100502; CEZ:AV0Z10100522 Keywords : cosmic ray * UHECR Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.808, year: 2010

  17. The LLNL CR-39 personnel neutron dosimeter

    International Nuclear Information System (INIS)

    Hankins, D.E.; Homann, S.; Westermark, J.

    1987-01-01

    We developed a personnel neutron dosimetry system based on the electrochemical etching of CR-39 plastic at elevated temperatures. The doses obtained using this dosimeter system are more accurate than those obtained using other dosimetry systems, especially when varied neutron spectra are encountered. This CR-39 dosimetry system does not have the severe energy dependence that exists with albedo neutron dosimeters or the fading and reading problems encountered with NTA film. 3 refs., 4 figs

  18. Cr 3d surface and bulk states in Sn1-xCrxTe/Cr crystals

    International Nuclear Information System (INIS)

    Guziewicz, E.; Szamota-Sadowska, K.; Kowalski, B.J.; Grodzicka, E.; Story, T.; Orlowski, B.A.; Johnson, R.L.

    1997-01-01

    We report a new approach to investigate metal-semiconductor interface formation. Photoemission spectroscopy was applied in order to investigate the clean surface of a Sn 0.97 Cr 0.03 Te crystal and to observe its changes under sequential deposition of small amounts of Cr atoms. In order to analyse the Cr 3d contribution to the valence band, the Fano-type resonance tuned to the Cr 3p-3d transmission was used. The experiment was designed to follow the Sn 0.97 Cr 0.03 Te/Cr interface formation process. At the clean Sn 0.97 Cr 0.03 Te surface, the Cr 3d states contribution to the valence band was found to be positioned 0.8 eV below Fermi level. After the Cr deposition processes the contribution shifted to a higher binding energy and another contribution 5.8 eV below the Fermi level also observed. (author)

  19. Estimation of track registration efficiency in solution medium and study of gamma irradiation effects on the bulk-etch rate and the activation energy for bulk etching of CR-39 (DOP) Solid State Nuclear Track Detector

    International Nuclear Information System (INIS)

    Kalsi, P.C.

    2010-01-01

    The fission track registration efficiency of diethylene glycol bis allyl carbonate (dioctyl phthalate doped) (CR-39 (DOP)) solid state nuclear track detector (SSNTD) in solution medium (K wet ) has been experimentally determined and is found to be (9.7 ± 0.5).10 -4 cm. This is in good agreement with the values of other SSNTDs. The gamma irradiation effects in the dose range of 50.0-220.0 kGy on the bulk etch rate, V b and the activation energy for bulk etching, E of this solid state nuclear track detector (SSNTD) have also been studied. It is observed that the bulk etch rates increase and the activation energies for bulk etching decrease with the increase in gamma dose. These results have been explained on the basis of scission of the detector due to gamma irradiation

  20. crRNA biogenesis

    NARCIS (Netherlands)

    Charpentier, E.; Oost, van der J.; White, M.

    2013-01-01

    Mature crRNAs are key elements in CRISPR-Cas defense against genome invaders. These short RNAs are composed of unique repeat/spacer sequences that guide the Cas protein(s) to the cognate invading nucleic acids for their destruction. The biogenesis of mature crRNAs involves highly precise processing

  1. The evolution of internal stress and dislocation during tensile deformation in a 9Cr ferritic/martensitic (F/M) ODS steel investigated by high-energy X-rays

    International Nuclear Information System (INIS)

    Zhang, Guangming; Zhou, Zhangjian; Mo, Kun; Miao, Yinbin; Liu, Xiang; Almer, Jonathan; Stubbins, James F.

    2015-01-01

    An application of high-energy wide angle synchrotron X-ray diffraction to investigate the tensile deformation of 9Cr ferritic/martensitic (F/M) ODS steel is presented. With tensile loading and in-situ X-ray exposure, the lattice strain development of matrix was determined. The lattice strain was found to decrease with increasing temperature, and the difference in Young's modulus of six different reflections at different temperatures reveals the temperature dependence of elastic anisotropy. The mean internal stress was calculated and compared with the applied stress, showing that the strengthening factor increased with increasing temperature, indicating that the oxide nanoparticles have a good strengthening impact at high temperature. The dislocation density and character were also measured during tensile deformation. The dislocation density decreased with increasing of temperature due to the greater mobility of dislocation at high temperature. The dislocation character was determined by best-fit methods for different dislocation average contrasts with various levels of uncertainty. The results shows edge type dislocations dominate the plastic strain at room temperature (RT) and 300 °C, while the screw type dislocations dominate at 600 °C. The dominance of edge character in 9Cr F/M ODS steels at RT and 300 °C is likely due to the pinning effect of nanoparticles for higher mobile edge dislocations when compared with screw dislocations, while the stronger screw type of dislocation structure at 600 °C may be explained by the activated cross slip of screw segments. - Highlights: • The tensile deformation of 9Cr ODS steel was studied by synchrotron irradiation. • The evolution of internal mean stress was calculated. • The evolution of dislocation character was determined by best-fit method. • Edge type dominates plasticity at RT and 300 °C, while screw type dominates at 600 °C.

  2. The evolution of internal stress and dislocation during tensile deformation in a 9Cr ferritic/martensitic (F/M) ODS steel investigated by high-energy X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guangming [School of Materials Science and Engineering, University of Science and Technology, Beijing, Beijing 100083 (China); Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, IL 61801 (United States); Zhou, Zhangjian, E-mail: zhouzhj@mater.ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology, Beijing, Beijing 100083 (China); Mo, Kun [Nuclear Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Miao, Yinbin; Liu, Xiang [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, IL 61801 (United States); Almer, Jonathan [X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Stubbins, James F. [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, IL 61801 (United States)

    2015-12-15

    An application of high-energy wide angle synchrotron X-ray diffraction to investigate the tensile deformation of 9Cr ferritic/martensitic (F/M) ODS steel is presented. With tensile loading and in-situ X-ray exposure, the lattice strain development of matrix was determined. The lattice strain was found to decrease with increasing temperature, and the difference in Young's modulus of six different reflections at different temperatures reveals the temperature dependence of elastic anisotropy. The mean internal stress was calculated and compared with the applied stress, showing that the strengthening factor increased with increasing temperature, indicating that the oxide nanoparticles have a good strengthening impact at high temperature. The dislocation density and character were also measured during tensile deformation. The dislocation density decreased with increasing of temperature due to the greater mobility of dislocation at high temperature. The dislocation character was determined by best-fit methods for different dislocation average contrasts with various levels of uncertainty. The results shows edge type dislocations dominate the plastic strain at room temperature (RT) and 300 °C, while the screw type dislocations dominate at 600 °C. The dominance of edge character in 9Cr F/M ODS steels at RT and 300 °C is likely due to the pinning effect of nanoparticles for higher mobile edge dislocations when compared with screw dislocations, while the stronger screw type of dislocation structure at 600 °C may be explained by the activated cross slip of screw segments. - Highlights: • The tensile deformation of 9Cr ODS steel was studied by synchrotron irradiation. • The evolution of internal mean stress was calculated. • The evolution of dislocation character was determined by best-fit method. • Edge type dominates plasticity at RT and 300 °C, while screw type dominates at 600 °C.

  3. Sulfidation behavior of Fe20Cr alloys

    International Nuclear Information System (INIS)

    Pillis, Marina Fuser

    2001-01-01

    Alloys for use in high temperature environments rely on the formation of an oxide layer for their protection. Normally, these protective oxides are Cr 2 O 3 , Al 2 O 3 and, some times, SiO 2 . Many industrial gaseous environments contain sulfur. Sulfides, formed in the presence of sulfur are thermodynamically less stable, have lower melting points and deviate much more stoichiometrically, compared to the corresponding oxides. The mechanism of sulfidation of various metals is as yet not clear, in spite of the concerted efforts during the last decade. To help address this situation, the sulfidation behavior of Fe20Cr has been studied as a function of compositional modifications and surface state of the alloy. The alloys Fe20Cr, Fe20Cr0.7Y, Fe20Cr5Al and Fe20Cr5Al0.6Y were prepared and three sets of sulfidation tests were carried out. In the first set, the alloys were sulfidized at 700 deg C and 800 deg C for 10h. In the second set, the alloys were pre-oxidized at 1000 deg C and then sulfidized at 800 deg C for up to 45h. In the third set of tests, the initial stages of sulfidation of the alloys was studied. All the tests were carried out in a thermobalance, in flowing H 2 /2%H 2 S, and the sulfidation behavior determined as mass change per unit area. Scanning electron microscopy coupled to energy dispersive spectroscopy and X-ray diffraction analysis were used to characterize the reaction products. The addition of Y and Al increased sulfidation resistance of Fe20Cr. The addition of Y altered the species that diffused predominantly during sulfide growth. It changed from predominant cationic diffusion to predominant anionic diffusion. The addition of Al caused an even greater increase in sulfidation resistance of Fe20Cr, with the parabolic rate constant decreasing by three orders of magnitude. Y addition to the FeCrAl alloy did not cause any appreciable alteration in sulfidation resistance. Pre-oxidation of the FeCrAl and FeCrAlY alloys resulted in an extended

  4. Compositional and structural properties of pulsed laser-deposited ZnS:Cr films

    Science.gov (United States)

    Nematollahi, Mohammadreza; Yang, Xiaodong; Seim, Eivind; Vullum, Per Erik; Holmestad, Randi; Gibson, Ursula J.; Reenaas, Turid W.

    2016-02-01

    We present the properties of Cr-doped zinc sulfide (ZnS:Cr) films deposited on Si(100) by pulsed laser deposition. The films are studied for solar cell applications, and to obtain a high absorption, a high Cr content (2.0-5.0 at.%) is used. It is determined by energy-dispersive X-ray spectroscopy that Cr is relatively uniformly distributed, and that local Cr increases correspond to Zn decreases. The results indicate that most Cr atoms substitute Zn sites. Consistently, electron energy loss and X-ray photoelectron spectroscopy showed that the films contain mainly Cr2+ ions. Structural analysis showed that the films are polycrystalline and textured. The films with ~4 % Cr are mainly grown along the hexagonal [001] direction in wurtzite phase. The average lateral grain size decreases with increasing Cr content, and at a given Cr content, increases with increasing growth temperature.

  5. The evolution of internal stress and dislocation during tensile deformation in a 9Cr ferritic/martensitic (F/M) ODS steel investigated by high-energy X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guangming; Zhou, Zhangjian; Mo, Kun; Miao, Yinbin; Liu, Xiang; Almer, Jonathan; Stubbins, James F.

    2015-12-01

    An application of high-energy wide angle synchrotron X-ray diffraction to investigate the tensile deformation of 9Cr ferritic/martensitic (F/M) ODS steel is presented. With tensile loading and in-situ Xray exposure, the lattice strain development of matrix was determined. The lattice strain was found to decrease with increasing temperature, and the difference in Young's modulus of six different reflections at different temperatures reveals the temperature dependence of elastic anisotropy. The mean internal stress was calculated and compared with the applied stress, showing that the strengthening factor increased with increasing temperature, indicating that the oxide nanoparticles have a good strengthening impact at high temperature. The dislocation density and character were also measured during tensile deformation. The dislocation density decreased with increasing of temperature due to the greater mobility of dislocation at high temperature. The dislocation character was determined by best-fit methods for different dislocation average contrasts with various levels of uncertainty. The results shows edge type dislocations dominate the plastic strain at room temperature (RT) and 300 C, while the screw type dislocations dominate at 600 C. The dominance of edge character in 9Cr F/M ODS steels at RT and 300 C is likely due to the pinning effect of nanoparticles for higher mobile edge dislocations when compared with screw dislocations, while the stronger screw type of dislocation structure at 600 C may be explained by the activated cross slip of screw segments.

  6. Towards highest peak intensities for ultra-short MeV-range ion bunches

    Science.gov (United States)

    Busold, Simon; Schumacher, Dennis; Brabetz, Christian; Jahn, Diana; Kroll, Florian; Deppert, Oliver; Schramm, Ulrich; Cowan, Thomas E.; Blažević, Abel; Bagnoud, Vincent; Roth, Markus

    2015-01-01

    A laser-driven, multi-MeV-range ion beamline has been installed at the GSI Helmholtz center for heavy ion research. The high-power laser PHELIX drives the very short (picosecond) ion acceleration on μm scale, with energies ranging up to 28.4 MeV for protons in a continuous spectrum. The necessary beam shaping behind the source is accomplished by applying magnetic ion lenses like solenoids and quadrupoles and a radiofrequency cavity. Based on the unique beam properties from the laser-driven source, high-current single bunches could be produced and characterized in a recent experiment: At a central energy of 7.8 MeV, up to 5 × 108 protons could be re-focused in time to a FWHM bunch length of τ = (462 ± 40) ps via phase focusing. The bunches show a moderate energy spread between 10% and 15% (ΔE/E0 at FWHM) and are available at 6 m distance to the source und thus separated from the harsh laser-matter interaction environment. These successful experiments represent the basis for developing novel laser-driven ion beamlines and accessing highest peak intensities for ultra-short MeV-range ion bunches. PMID:26212024

  7. Towards highest peak intensities for ultra-short MeV-range ion bunches

    Science.gov (United States)

    Busold, Simon; Schumacher, Dennis; Brabetz, Christian; Jahn, Diana; Kroll, Florian; Deppert, Oliver; Schramm, Ulrich; Cowan, Thomas E.; Blažević, Abel; Bagnoud, Vincent; Roth, Markus

    2015-07-01

    A laser-driven, multi-MeV-range ion beamline has been installed at the GSI Helmholtz center for heavy ion research. The high-power laser PHELIX drives the very short (picosecond) ion acceleration on μm scale, with energies ranging up to 28.4 MeV for protons in a continuous spectrum. The necessary beam shaping behind the source is accomplished by applying magnetic ion lenses like solenoids and quadrupoles and a radiofrequency cavity. Based on the unique beam properties from the laser-driven source, high-current single bunches could be produced and characterized in a recent experiment: At a central energy of 7.8 MeV, up to 5 × 108 protons could be re-focused in time to a FWHM bunch length of τ = (462 ± 40) ps via phase focusing. The bunches show a moderate energy spread between 10% and 15% (ΔE/E0 at FWHM) and are available at 6 m distance to the source und thus separated from the harsh laser-matter interaction environment. These successful experiments represent the basis for developing novel laser-driven ion beamlines and accessing highest peak intensities for ultra-short MeV-range ion bunches.

  8. Thermodynamic Assessment of the La-Cr-O System

    DEFF Research Database (Denmark)

    Povoden, E.; Chen, Ming; Grundy, A.N.

    2009-01-01

    of oxygen partial pressure. In the La-Cr system reported solubility of lanthanum in bcc chromium is considered in the modeling. In the La-Cr-O system the Gibbs energy functions of La2CrO6, La-2(CrO4)(3), and perovskite-structured LaCrO3 are presented, and oxygen solubilities in bcc and fcc metals......The La-Cr and the La-Cr-O systems are assessed using the Calphad approach. The calculated La-Cr phase diagram as well as LaO1.5-CrO1.5 phase diagrams in pure oxygen, air, and under reducing conditions are presented. Phase equilibria of the La-Cr-O system are calculated at 1273 K as a function...... are modeled. Emphasis is placed on a detailed description of the perovskite phase: the orthorhombic to rhombohedral transformation and the contribution to the Gibbs energy due to a magnetic order-disorder transition are considered in the model. The following standard data of stoichiometric perovskite...

  9. Modeling of chromium precipitation in Fe-Cr alloys

    International Nuclear Information System (INIS)

    Wallenius, J.; Olsson, P.; Lagerstedt, C.; Sandberg, N.; Chakarova, R.; Pontikis, V.

    2004-01-01

    We have implemented a set of Embedded Atom Method (EAM) potentials for simulation of Fe-Cr alloys. The functions for the pure elements were fitted to the respective elastic constants, vacancy formation energy, and thermal expansion coefficients. For Cr, properties of the paramagnetic state were applied, providing a positive Cauchy pressure and hence applicability of the EAM. By relaxing the requirement of reproducing the pressure-volume relation at short interaction distances, stability of the self-interstitial could be obtained. Our Fe-potential gives E lang110rang f -E lang111rang f =-0.23 eV. Mixed Fe-Cr pair potentials were fitted to the calculated mixing enthalpy of ferromagnetic Fe-Cr, which is negative for Cr concentrations below 6%. Simulation of thermal aging in Fe-Cr alloys using a potential fitted to the mixing enthalpy of Fe-20Cr exhibited pronounced Cr-precipitation for temperatures below 900 K, in agreement with the phase diagram. No such ordering was observed at any temperature using a potential fitted to the mixing enthalpy of Fe-5Cr. Applied to recoil cascade simulations the new potentials predict a smaller number of surviving defects than potentials found in the literature. We obtain a cascade efficiency of 0.135 NRT for damage energies in between 10 and 20 keV. An enhanced probability for Cr atoms to end up in defect structures is observed

  10. In silico CrNF, a half-metallic ferromagnetic nitride–fluoride mimicking CrO2

    International Nuclear Information System (INIS)

    Matar, Samir F.

    2014-01-01

    Isoelectronic with CrO 2 , CrNF is proposed in silico based on rutile derived structures with DFT computations. The ground state structure defined from cohesive energies is of MgUO 4 -type, characterized by short covalent Cr–N and long ionic Cr–F distances. Like CrO 2 it is a half-metallic ferromagnet with M=2 μ B /FU integer magnetization with reduced band gap at minority spins. Major difference of magnetic response to pressure characterizes CrNF as a soft ferromagnet versus hard magnetic CrO 2 . The chemical bonding properties point to prevailing covalent Cr–N versus ionic Cr–F bonding. Different synthesis routes are examined. - Highlights: • DFT identification of CrNF is based on isoelectronicity and rutile derivatives. • Similarly to CrO 2 , CrNF is a half-metallic ferromagnet with reduced band gap. • Strong pressure dependence of magnetization of CrNF oppositely to CrO 2 . • Covalent Cr–N bonding prevails in spite of the presence of ionic Cr–F. • Cohesive energies favor the synthesis for which protocols are proposed

  11. BISON Fuel Performance Analysis of FeCrAl cladding with updated properties

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); George, Nathan M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wirth, Brian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-30

    In order to improve the accident tolerance of light water reactor (LWR) fuel, alternative cladding materials have been proposed to replace zirconium (Zr)-based alloys. Of these materials, there is a particular focus on iron-chromium-aluminum (FeCrAl) alloys due to much slower oxidation kinetics in high-temperature steam than Zr-alloys. This should decrease the energy release due to oxidation and allow the cladding to remain integral longer in the presence of high temperature steam, making accident mitigation more likely. As a continuation of the development for these alloys, suitability for normal operation must also be demonstrated. This research is focused on modeling the integral thermo-mechanical performance of FeCrAl-cladded fuel during normal reactor operation. Preliminary analysis has been performed to assess FeCrAl alloys (namely Alkrothal 720 and APMT) as a suitable fuel cladding replacement for Zr-alloys, using the MOOSE-based, finite-element fuel performance code BISON and the best available thermal-mechanical and irradiation-induced constitutive properties. These simulations identify the effects of the mechanical-stress and irradiation response of FeCrAl, and provide a comparison with Zr-alloys. In comparing these clad materials, fuel rods have been simulated for normal reactor operation and simple steady-state operation. Normal reactor operating conditions target the cladding performance over the rod lifetime (~4 cycles) for the highest-power rod in the highest-power fuel assembly under reactor power maneuvering. The power histories and axial temperature profiles input into BISON were generated from a neutronics study on full-core reactivity equivalence for FeCrAl using the 3D full core simulator NESTLE. Evolution of the FeCrAl cladding behavior over time is evaluated by using steady-state operating conditions such as a simple axial power profile, a constant cladding surface temperature, and a constant fuel power history. The fuel rod designs and

  12. Structure and grindability of dental Ti-Cr alloys

    International Nuclear Information System (INIS)

    Hsu, H.-C.; Wu, S.-C.; Chiang, T.-Y.; Ho, W.-F.

    2009-01-01

    The purpose of this study was to investigate the structure and microhardness of a series of binary Ti-Cr alloys with Cr contents up to 30 wt%. In addition, the grindability was also evaluated using an electric dental handpiece with SiC wheels, with the goal of developing a titanium alloy with better mechanical properties and machinability than commercially pure titanium (c.p. Ti), a metal generally considered to be difficult to machine. This study evaluated the phase and structure of Ti-Cr alloys, using an X-ray diffraction (XRD) for phase analysis and optical microscope for microstructure of the etched alloys. Grindability was evaluated by measuring the amount of metal volume removed after grinding for 1 min. Results indicated that the structure of Ti-Cr alloys is sensitive to the Cr content. The cast c.p. Ti has a hexagonal α phase. With 5 wt% Cr, metastable β phase starts to be retained. With Cr contents higher than 10 wt%, the equi-axed β phase is almost entirely retained. In addition, athermal ω phase was found in the Ti-5Cr and Ti-10Cr alloys. The largest quantity of ω phase and highest microhardness were found in Ti-10Cr alloy. The grinding rate of the Ti-Cr alloys showed a similar tendency to the microhardness. The Ti-10Cr alloy exhibited the best grindability, especially at 1000 m/min, which presumably due to the brittle nature of the alloy containing the ω phase in the β matrix.

  13. Doping of Czochralski-grown bulk β-Ga2O3 single crystals with Cr, Ce and Al

    Science.gov (United States)

    Galazka, Zbigniew; Ganschow, Steffen; Fiedler, Andreas; Bertram, Rainer; Klimm, Detlef; Irmscher, Klaus; Schewski, Robert; Pietsch, Mike; Albrecht, Martin; Bickermann, Matthias

    2018-03-01

    We experimentally evaluated segregation of Cr, Ce and Al in bulk β-Ga2O3 single crystals grown by the Czochralski method, as well as the impact of these dopants on optical properties. The segregation of Cr and Ce and their incorporation into the β-Ga2O3 crystal structure strongly depends on O2 concentration in the growth atmosphere which has a noticeable impact on decomposition of Ga2O3 and Cr2O3, as well as on the charge state of Cr and Ce. Effective segregation coefficients for Cr are in the range of 3.1-1.5 at 7-24 vol% O2, while for Ce they are roughly below 0.01 at 1.5-34 vol% O2. The effective segregation coefficient for Al is 1.1 at 1.5-21 vol% O2. Both dopants Ce and Al have a thermodynamically stabilizing effect on β-Ga2O3 crystal growth by supressing decomposition. While Ce has no impact on the optical transmittance in the ultraviolet and visible regions, in Cr doped crystals we observe three absorption bands due to Cr3+ on octahedral Ga sites, one in the ultraviolet merging with the band edge absorption of β-Ga2O3 and two in the visible spectrum, for which we estimate the absorption cross sections. Al doping also does not induce dopant related absorption bands but clearly shifts the absorption edge as one expects for a solid-solution crystal Ga2(1-x)Al2xO3 still in the monoclinic phase. For the highest doping concentration (Ga1.9Al0.1O3) we estimate an increase of the energy gap by 0.11 eV.

  14. Interface bonding of NiCrAlY coating on laser modified H13 tool steel surface

    Science.gov (United States)

    Reza, M. S.; Aqida, S. N.; Ismail, I.

    2016-06-01

    Bonding strength of thermal spray coatings depends on the interfacial adhesion between bond coat and substrate material. In this paper, NiCrAlY (Ni-164/211 Ni22 %Cr10 %Al1.0 %Y) coatings were developed on laser modified H13 tool steel surface using atmospheric plasma spray (APS). Different laser peak power, P p, and duty cycle, DC, were investigated in order to improve the mechanical properties of H13 tool steel surface. The APS spraying parameters setting for coatings were set constant. The coating microstructure near the interface was analyzed using IM7000 inverted optical microscope. Interface bonding of NiCrAlY was investigated by interfacial indentation test (IIT) method using MMT-X7 Matsuzawa Hardness Tester Machine with Vickers indenter. Diffusion of atoms along NiCrAlY coating, laser modified and substrate layers was investigated by energy-dispersive X-ray spectroscopy (EDXS) using Hitachi Tabletop Microscope TM3030 Plus. Based on IIT method results, average interfacial toughness, K avg, for reference sample was 2.15 MPa m1/2 compared to sample L1 range of K avg from 6.02 to 6.96 MPa m1/2 and sample L2 range of K avg from 2.47 to 3.46 MPa m1/2. Hence, according to K avg, sample L1 has the highest interface bonding and is being laser modified at lower laser peak power, P p, and higher duty cycle, DC, prior to coating. The EDXS analysis indicated the presence of Fe in the NiCrAlY coating layer and increased Ni and Cr composition in the laser modified layer. Atomic diffusion occurred in both coating and laser modified layers involved in Fe, Ni and Cr elements. These findings introduce enhancement of coating system by substrate surface modification to allow atomic diffusion.

  15. Statistical lifetime modeling of FeNiCr alloys for high temperature corrosion in waste to energy plants and metal dusting in syngas production plants

    OpenAIRE

    Camperos Guevara, Sheyla Herminia

    2016-01-01

    Over the last decades, the corrosion control of alloys exposed to severe and complex conditions in industrial applications has been a great challenge. Currently, corrosion costs are increasing and preventive strategies have become an important industrial demand. The SCAPAC project funded by the French National Research Agency has proposed to study the corrosion for two separate processes: Steam Methane Reforming (SMR) and Waste to Energy (WtE). Although the operating conditions of both proces...

  16. Black Cr/α-Cr2O3 nanoparticles based solar absorbers

    International Nuclear Information System (INIS)

    Khamlich, S.; Nemraoui, O.; Mongwaketsi, N.; McCrindle, R.; Cingo, N.; Maaza, M.

    2012-01-01

    Monodisperse spherical core–shell particles of Cr/α-Cr 2 O 3 with high adhesion were successfully coated on rough copper substrates by a simple self-assembly-like method for the use in solar thermal absorbers. The structure and morphology of the core-shell particles of Cr/α-Cr 2 O 3 were effectively controlled by deposition temperature and the pH of the initial precursor solution. Their characterizations were carried out with X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry and attenuated total reflection, as well as UV–vis diffuse reflectance spectroscopy. The samples aged for more than 40 h at 75 °C exhibit the targeted high absorbing optical characteristic “Black chrome” while those aged for ≤40 h show a significant high UV–vis diffuse reflectance “green color”.

  17. The 52Cr(p, γ)53Mn reaction

    NARCIS (Netherlands)

    Vuister, P.H.

    The 52Cr(p, γ)53Mn reaction was investigated in the energy region Ep = 1.36–2.26 MeV. The resonance energies, the corresponding 53Mn excitation energies and the resonance strengths of 199 resonances, assigned to this reaction, are reported. The excitation energies and gamma-ray branchings of 13

  18. Changes of surface structure of Ni, W and chromium-nickel steel Cr18Ni10 irradiated by high fluences of krypton ions with high energies

    International Nuclear Information System (INIS)

    Didyk, A.Yu.; Semina, V.K.; Khalil, A.; Suvorov, A.L.; Stepanov, A.Eh.; Cheblukov, Yu.N.

    1999-01-01

    The surfaces of W single crystal, Ni polycrystal and chromium-nickel steel, irradiated by Kr ions with energy 305 and 245 MeV up to the fluences 2*10 15 and 3*10 15 ion/cm 2 , were studied by means of scanning electron microscopy. The evaporation coefficients of material surfaces were estimated on the base of changes of surface relief. The values of these coefficients turned out much more than ones predicted by the inelastic sputtering model. The method of 'step' was offered and realized for the more correct estimations evaporation coefficient on the Ni example. The phenomenological model explaining the observed phenomena is introduced

  19. Microcosm investigation on phytoremediation of Cr using Azolla pinnata.

    Science.gov (United States)

    Rai, Prabhat Kumar

    2010-01-01

    The extent of Chromium (Cr) pollution in Singrauli industrial region, India was assessed and phytoremediation capacity of a small water fern, Azolla pinnata R.BR (Azollaceae) was observed to purify waters polluted by Cr under microcosm condition. Azolla pinnata endemic to India is a potential hyper-accumulator of heavy metals. During 13 days of the experiment the fern was grown in the aqueous medium containing Cr3+ and CrO4(2-) ions, each in a concentration 0.5, 1.0, and 3.0 mg L(-1). The presence of these ions caused a + 3.1 to -37.5% inhibition of Azolla pinnata growth in comparison to the control. After 13 days of the experiment, metal contents in the solution was decreased up to 70% (CrO4(2-) 3.0 mg L(-1) treatment) to 88% (CrO4(2-) 0.5 mg L(-1) treatment). In the Azolla pinnata tissues, the concentration of couple of the ionic forms of Cr under investigation ranged from 415 to 1095 mg kg(-1) dry mass (dm); the highest level being found for Cr (III) containing solution.

  20. Investigations of CR39 dosimeters for neutron routine dosimetry

    International Nuclear Information System (INIS)

    Weinstein, M.; Abraham, A.; Tshuva, A.; German, U.

    2004-01-01

    CR-39 is a polymeric nuclear track detector which is widely used for neutron dosimetry. CR-39 detector development was conducted at a number of laboratories throughout the world(1,2) , and was accepted also for routine dosimetry. However, there are shortcomings which must be taken into consideration the lack of a dosimetry grade material which causes batch variations, significant angular dependence and a moderate sensitivity. CR-39 also under-responds for certain classes of neutron spectra (lower energy neutrons from reactors or high energy accelerator-produced neutrons).In order to introduce CR-39 as a routine dosimeter at NRCN, a series of checks were performed. The present work describes the results of some of our checks, to characterize the main properties of CR-39 dosimeters

  1. Magnetism of CrO overlayers on Fe(001)bcc surface: first principles calculations

    Science.gov (United States)

    Félix-Medina, Raúl Enrique; Leyva-Lucero, Manuel Andrés; Meza-Aguilar, Salvador; Demangeat, Claude

    2018-04-01

    Riva et al. [Surf. Sci. 621, 55 (2014)] as well as Calloni et al. [J. Phys.: Condens. Matter 26, 445001 (2014)] have studied the oxydation of Cr films deposited on Fe(001)bcc through low-energy electron diffraction, Auger electron spectroscopy and scanning tunneling microscopy. In the present work we perform a density functional approach within Quantum Expresso code in order to study structural and magnetic properties of CrO overlayers on Fe(001)bcc. The calculations are performed using DFT+U. The investigated systems include O/Cr/Fe(001)bcc, Cr/O/Fe(001)bcc, Cr0.25O0.75/Fe(001)bcc, as well as the O coverage Ox/Cr/Fe(001)bcc (x = 0.25; 0.50). We have found that the ordered CrO overlayer presents an antiferromagnetic coupling between Cr and Fe atoms. The O atoms are located closer to the Fe atoms of the surface than the Cr atoms. The ground state of the systems O/Cr/Fe(001)bcc and Cr/O/Fe(001)bcc corresponds to the O/Cr/Fe(001)bcc system with a magnetic coupling c(2 × 2). The effect of the O monolayer on Cr/Fe(001)bcc changes the ground state from p(1 × 1) ↓ to c(2 × 2) and produces an enhancement of the magnetic moments. The Ox overlayer on Cr/Fe(001)bcc produces an enhancement of the Cr magnetic moments.

  2. Millimeter-wave spectroscopy of CrC (X(3)Σ(-)) and CrCCH (X̃ (6)Σ(+)): Examining the chromium-carbon bond.

    Science.gov (United States)

    Min, J; Ziurys, L M

    2016-05-14

    Pure rotational spectroscopy of the CrC (X(3)Σ(-)) and CrCCH (X̃ (6)Σ(+)) radicals has been conducted using millimeter/sub-millimeter direct absorption methods in the frequency range 225-585 GHz. These species were created in an AC discharge of Cr(CO)6 and either methane or acetylene, diluted in argon. Spectra of the CrCCD were also recorded for the first time using deuterated acetylene as the carbon precursor. Seven rotational transitions of CrC were measured, each consisting of three widely spaced, fine structure components, arising from spin-spin and spin-rotation interactions. Eleven rotational transitions were recorded for CrCCH and five for CrCCD; each transition in these cases was composed of a distinct fine structure sextet. These measurements confirm the respective (3)Σ(-) and (6)Σ(+) ground electronic states of these radicals, as indicated from optical studies. The data were analyzed using a Hund's case (b) Hamiltonian, and rotational, spin-spin, and spin-rotation constants have been accurately determined for all three species. The spectroscopic parameters for CrC were significantly revised from previous optical work, while those for CrCCH are in excellent agreement; completely new constants were established for CrCCD. The chromium-carbon bond length for CrC was calculated to be 1.631 Å, while that in CrCCH was found to be rCr-C = 1.993 Å - significantly longer. This result suggests that a single Cr-C bond is present in CrCCH, preserving the acetylenic structure of the ligand, while a triple bond exists in CrC. Analysis of the spin constants suggests that CrC has a nearby excited (1)Σ(+) state lying ∼16 900 cm(-1) higher in energy, and CrCCH has a (6)Π excited state with E ∼ 4800 cm(-1).

  3. A study on alpha particles range in Cr-39

    International Nuclear Information System (INIS)

    Ibrahim, Z.A.; Talaat, T.M.; Abdel-Aziz, Kh.M.A.; El-Asser, M.R.

    2000-01-01

    Cr-39 plastic nuclear track detector has been used in range determination of alpha particles. A set of experiments was carried out for studying alpha energy and track diameter relationships. This work was done under the optimum conditions of Cr-39 etching in 6.25 N NaOH at 70 degree C for various etching times. Determination of alpha range in Cr-39 recorders was studied at different energy values using the over etched track profile technique. Data are discussed within the framework of track formation theory in plastic foils, comparison between experimental and theoretical values of alpha range is included

  4. Nuclear structure of 54Cr

    International Nuclear Information System (INIS)

    Saini, S.; Gunye, M.R.

    1980-01-01

    The large amount of the experimental data accumulated in recent years on the levels of fp-shell nuclei, especially on the properties of the high spin states studied through heavy-ion reactions, needs to be explained systematically on theoretical basis. The exact shell model calculations are not feasible for most of these nuclei. The restricted shell-model calculations, however, do not give a proper account of the experimental data. The nuclear structure of 54 Cr has been investigated in the framework of Hartree-Fock Projection formation employing effective interaction in the configuration space of the full fp-shell. The band-mixed wave functions obtained from the lowest four intrinsic states have been used to compute energy levels and electromagnetic properties. The present calculations give a fairly good account of the available data. (author)

  5. Neutron dosimeter utilizing CR-39

    International Nuclear Information System (INIS)

    Souza, H.V.C. de.

    1991-05-01

    A personnel neutron dosimeter has been developed with discretization in a wide range of energies of real interest, utilizing the CR-39 polymer, to detect recoil protons in the fast range, and alpha particles in the thermal and epithermal ranges, with possibility to be disposed in the IRD/CNEN's conventional film badge suport. They are presented, abstractly, the difficulties and importance of the neutron dosimetry, beyond the general objectives that motivated this work execution. The details of the materials utilized in the dosimeter confection, and the experimental methodology employed to obtain the performance curves are presented. The results about linearity response of the dosimeter with respect to equivalent dose, in a wide range of doses, and about the verified angular dependence are analysed. (author)

  6. Interdiffusion processes at irradiated Cr/Si interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Luneville, L., E-mail: laurence.luneville@cea.fr [DEN/DANS/DM2S/SERMA/LLPR/LRC-CARMEN, CEA Saclay, 91191 Gif-sur-Yvette (France); Largeau, L. [LPN-UPR20/CNRS, Route de Nozay, 91460 Marcoussis (France); Deranlot, C. [Unite Mixte de Physique CNRS/Thales, 1 Avenue Augustin Fresnel, 91767 Palaiseau (France); Ribis, J. [DEN/DANS/DMN/SRMA/LA2M/LRC-CARMEN, CEA Saclay, 91191 Gif-sur-Yvette (France); Ott, F. [DSM/IRAMIS/LLB/CEA/CNRS, CEA Saclay, 91191 Gif-sur-Yvette (France); Moncoffre, N. [IPNL/CNRS, Domaine scientifique de la Doua, 69622 Villeurbanne (France); Baldinozzi, G. [CNRS-SPMS/UMR 8580/LRC CARMEN Ecole Centrale Paris, 92295 Chatenay-Malabry (France); Simeone, D. [DEN/DANS/DMN/SRMA/LA2M/LRC-CARMEN, CEA Saclay, 91191 Gif-sur-Yvette (France)

    2015-03-25

    Highlights: • Interdiffusion at Cr/Si interfaces induced by ion beam mixing at room temperature. • Creation of Cr/Si alloy metastable phases. • Reconstruction of Cr/Si interdiffusion profile by X-ray reflectometry. • Quantitative correlation between Cr and Si profiles extracted from XRR and measured by EDX–TEM. - Abstract: Chromium silicon CrSi alloys are foreseen as possible materials for spintronic devices. Ion beam mixing could be an efficient technique to produce thin films of such alloys at room temperature while avoiding thermal diffusion. In order to assess this point, we have irradiated 20 nm Cr layer on a (1 0 0) Si wafer with 70 keV Kr ions. The X-ray reflectometry technique combined with Transmission Electron Microscopy and Energy Dispersive X-ray analysis was applied to analyze, at the nanometric scale, the formation of Cr/Si blurred interfaces induced by ion beam mixing. From the analysis of reflectivity curves, it appears that nanometric Cr{sub 5}Si{sub 3} and CrSi{sub 2} phases are produced at the early stage of the process. The existence of these two paramagnetic phases gives some clues to explain the reason why the experimentally observed ferrimagnetism was weaker than predicted.

  7. Characterization of ion-irradiated ODS Fe–Cr alloys by doppler broadening spectroscopy using a positron beam

    Energy Technology Data Exchange (ETDEWEB)

    Parente, P.; Leguey, T. [Departamento de Física and IAAB, Universidad Carlos III de Madrid, 28911 Leganés (Spain); Castro, V. de, E-mail: vanessa.decastro@uc3m.es [Departamento de Física and IAAB, Universidad Carlos III de Madrid, 28911 Leganés (Spain); Gigl, T.; Reiner, M.; Hugenschmidt, C. [FRM II and Physics Department, Technische Universität München, 85747 Garching (Germany); Pareja, R. [Departamento de Física and IAAB, Universidad Carlos III de Madrid, 28911 Leganés (Spain)

    2015-09-15

    The damage profile of oxide dispersion strengthened steels after single-, or simultaneous triple-ion irradiation at different conditions has been characterized using a low energy positron beam in order to provide information on microstructural changes induced by irradiation. Doppler broadening and coincident Doppler broadening measurements of the positron annihilation line have been performed on different Fe–Cr–(W,Ti) alloys reinforced with Y{sub 2}O{sub 3}, to identify the nature and stability of irradiation-induced open-volume defects and their possible association with the oxide nanoparticles. It was found that irradiation induced vacancy clusters are associated with Cr atoms. The results are of highest interest for modeling the damage induced by 14 MeV neutrons in reduced activation Fe–Cr alloys relevant for fusion devices.

  8. Characterization of ion-irradiated ODS Fe–Cr alloys by doppler broadening spectroscopy using a positron beam

    International Nuclear Information System (INIS)

    Parente, P.; Leguey, T.; Castro, V. de; Gigl, T.; Reiner, M.; Hugenschmidt, C.; Pareja, R.

    2015-01-01

    The damage profile of oxide dispersion strengthened steels after single-, or simultaneous triple-ion irradiation at different conditions has been characterized using a low energy positron beam in order to provide information on microstructural changes induced by irradiation. Doppler broadening and coincident Doppler broadening measurements of the positron annihilation line have been performed on different Fe–Cr–(W,Ti) alloys reinforced with Y 2 O 3 , to identify the nature and stability of irradiation-induced open-volume defects and their possible association with the oxide nanoparticles. It was found that irradiation induced vacancy clusters are associated with Cr atoms. The results are of highest interest for modeling the damage induced by 14 MeV neutrons in reduced activation Fe–Cr alloys relevant for fusion devices

  9. Structure and grindability of cast Ti-5Cr-xFe alloys

    International Nuclear Information System (INIS)

    Hsu, H.-C.; Pan, C.-H.; Wu, S.-C.; Ho, W.-F.

    2009-01-01

    The purpose of this study was to investigate the structure, microhardness and grindability of Ti-5Cr and a series of ternary Ti-5Cr-xFe alloys with 0.1, 0.5, 1, 3 and 5 wt.% Fe, respectively. This study evaluated the phase and structure of Ti-5Cr and Ti-5Cr-xFe alloys, using an X-ray diffraction (XRD) for phase analysis and optical microscope for microstructure of the etched alloys. In addition, grindability was evaluated by measuring the amount of metal volume removed after grinding for 1 min at each of the four rotational speeds of the wheel (500, 750, 1000 or 1200 m/min), with the goal of developing a titanium alloy with better machinability than commercially pure titanium (c.p. Ti). The results showed that the structure of Ti-5Cr-xFe alloys is sensitive to the Fe content. With Fe contents higher than 0.5 wt.%, the equi-axed β phase is entirely retained, while ω phase was found in the Ti-5Cr, Ti-5Cr-0.1Fe, Ti-5Cr-0.5Fe and Ti-5Cr-1Fe alloys. The largest quantity of ω phase and highest microhardness were found in Ti-5Cr-0.5Fe and Ti-5Cr-1Fe alloys. The grinding rates of the Ti-5Cr and Ti-5Cr-xFe alloys showed a similar tendency to the microhardness. The Ti-5Cr, Ti-5Cr-0.1Fe, Ti-5Cr-0.5Fe and Ti-5Cr-1Fe alloys exhibited the best grindability, especially at 500, 750 and 1000 m/min. Furthermore, the grindability of the tested metals increased in proportion to grinding speed up to 1000 m/min, with a decrease after 1200 m/min. This study concluded that Fe may be used to harden titanium and improve the grindability

  10. Characterization of Cr-rich Cr-Sb multilayer films: Syntheses of a new metastable phase using modulated elemental reactants

    International Nuclear Information System (INIS)

    Regus, Matthias; Mankovsky, Sergiy; Polesya, Svitlana; Kuhn, Gerhard; Ditto, Jeffrey; Schürmann, Ulrich; Jacquot, Alexandre; Bartholomé, Kilian; Näther, Christian; Winkler, Markus; König, Jan D.; Böttner, Harald; Kienle, Lorenz; Johnson, David C.; Ebert, Hubert; Bensch, Wolfgang

    2015-01-01

    The new metastable compound Cr 1+x Sb with x up to 0.6 has been prepared via a thin film approach using modulated elemental reactants and investigated by in-situ X-ray reflectivity, X-ray diffraction, differential scanning calorimetry, energy dispersive X-ray analysis as well as transmission electron microscopy and atomic force microscopy. The new Cr-rich antimonide crystallizes in a structure related to the Ni 2 In-type structure, where the crystallographic position (1/3, 2/3, 3/4) is partially occupied by excess Cr. The elemental layers of the pristine material interdiffused significantly before Cr 1+x Sb crystallized. A change in the activation energy was observed for the diffusion process when crystal growth starts. First-principles electronic structure calculations provide insight into the structural stability, magnetic properties and resistivity of Cr 1+x Sb. - Graphical abstract: 1 amorphous multilayered film 2 interdiffused amorphous film 3 metastable crystalline phase 4 thermodynamic stable phase (and by-product). - Highlights: • Interdiffusion of amorphous Cr and Sb occurs before crystallization. • Crystallization of a new metastable phase Cr 1.6 Sb in Ni 2 In-type structure. • The new Cr-rich phase shows half-metallic behavior

  11. Electronic and magnetic properties of SmCrSb3 and GdCrSb3: A first principles study

    International Nuclear Information System (INIS)

    Sandeep; Ghimire, M.P.; Thapa, R.K.

    2011-01-01

    The density of states (DOS) and the magnetic moments of SmCrSb 3 and GdCrSb 3 have been studied by first principles full-potential linearized augmented plane wave (FP-LAPW) method based on density functional theory (DFT). For the exchange-correlation potential, the local-spin density approximations with correlation energy (LSDA+U) method have been used. Total and partial DOS have been computed using the WIEN2k code. DOS result shows the exchange-splittings of Cr-3d and rare-earth (R) 4f states electrons, which are responsible for the ground state ferromagnetic (FM) behavior of the systems. The FM behavior of these systems is strongly influenced by the average number of Cr-3d and Sm (Gd) 4f-electrons. The effective moment of SmCrSb 3 is found to be 7.07 μ B while for GdCrSb 3 it is 8.27 μ B . The Cr atom plays a significant role on the magnetic properties due to the hybridization between Cr-3d and Sb-5p states. - Highlights: → DOS and the magnetic moments of SmCrSb 3 and GdCrSb 3 are studied by full-FP-LAPW method. → Exchange splitting of eg and t2g of Cr-3d states and the rare-earth 4f state electrons are responsible for ground state ferromagnetism. → Rare-earth magnetic moments are greater than Cr moment indicating presence of 4f states.

  12. On creep of directionally solidified eutectic Co-Cr-C-base superalloys

    International Nuclear Information System (INIS)

    Hildebrandt, U.W.

    1981-01-01

    It is shown in the present paper that the stress exponent and the activation energy of an Al-modified 73 C-alloy agree with the following mechanisms: diffusion controlled climbing of dislocation takes place and, the activation energy is in accordance with the self-diffusion energy of chromium, particularly that of Cr in Cr 7 C 3 . (orig.) [de

  13. The complementary relationship (CR) approach aids evapotranspiration estimation in the data scarce region of Tibetan Plateau: symmetric and asymmetric perspectives

    Science.gov (United States)

    Ma, N.; Zhang, Y.; Szilagyi, J.; Xu, C. Y.

    2015-12-01

    While the land surface latent and sensible heat release in the Tibetan Plateau (TP) could greatly influence the Asian monsoon circulation, the actual evapotranspiration (ETa) information in the TP has been largely hindered by its extremely sparse ground observation network. Thus the complementary relationship (CR) theory lends great potential in estimating the ETa since it relies on solely routine meteorological observations. With the in-situ energy/water flux observation over the highest semiarid alpine steppe in the TP, the modifications of specific components within the CR were first implemented. We found that the symmetry of the CR could be achieved for dry regions of TP when (i) the Priestley-Taylor coefficient, (ii) the slope of the saturation vapor pressure curve and (iii) the wind function were locally calibrated by using the ETa observations in wet days, an estimate of the wet surface temperature and the Monin-Obukhov Similarity (MOS) theory, respectively. In this way, the error of the simulated ETa by the symmetric AA model could be decreased to a large extent. Besides, the asymmetric CR was confirmed in TP when the D20 above-ground and/or E601B sunken pan evaporation (Epan) were used as a proxy of the ETp. Thus daily ETa could also be estimated by coupling D20 above-ground and/or E601B sunken pans through CR. Additionally, to overcome the modification of the specific components in the CR, we also evaluated the Nonlinear-CR model and the Morton's CRAE model. The former does not need the pre-determination of the asymmetry of CR, while the latter does not require the wind speed data as input. We found that both models are also able to simulate the daily ETa well provided their parameter values have been locally calibrated. The sensitivity analysis shows that, if the measured ETa data are absence to calibrate the models' parameter values, the Nonlinear-CR model may be a particularly good way for estimating ETabecause of its mild sensitivity to the parameter

  14. Kinetic stable Cr isotopic fractionation between aqueous Cr(III)-Cl-H2O complexes at 25 °C: Implications for Cr(III) mobility and isotopic variations in modern and ancient natural systems

    Science.gov (United States)

    Babechuk, Michael G.; Kleinhanns, Ilka C.; Reitter, Elmar; Schoenberg, Ronny

    2018-02-01

    The stable Cr isotope fractionation preserved in natural substances has been attributed predominantly to Cr(III)-Cr(VI) redox transformations. However, non-redox reaction pathways (e.g., ligand-promoted dissolution, ligand exchange, adsorption of Cr(III)) are liable to contribute to isotopic fractionation in natural systems given that soluble Cr(III)-ligands have been directly documented or modeled in several marine, continental, and hydrothermal environments. This study isolates the stable Cr isotope fractionation accompanying Cl-H2O ligand exchange during the transformation of three aqueous species in the Cr(III)-Cl-H2O system, [CrCl2(H2O)4]+aq (abr. CrCl2+ or S1), [CrCl(H2O)5]2+aq (abr. CrCl2+ or S2), and [Cr(H2O)6]3+aq (abr. Cr3+ or S3), at low pH (≤2). In dilute HCl (0.01 to 1 M), Cr3+ is the kinetically favoured species and transformation of CrCl2+ to CrCl2+ to Cr3+ via 2 steps of dechlorination/hydrolyzation begins immediately upon dissolution of a Cr(III)-Cl solid. Individual species are separated with cation exchange chromatography at different stages of transformation and inter- and intra-species (across an elution peak of one species) isotopic fractionation of up to 1 and 2‰ (δ53/52Cr), respectively, is documented. Comparison of peak elution characteristics with Cr-Cl-H-O isotopologue mass abundances suggests mass-dependent sorting of isotopologues alone cannot explain intra-species fractionation, supporting a previously published proposal that preferential adsorption of light Cr isotopes on the resin is driven by vibrational energy effects. The transformation of CrCl2+ to CrCl2+ is faster than CrCl2+ to Cr3+ and the rates of both transformations increase with solution pH. Preferential reaction of light Cr(III) isotopes into product species occurs during each transformation, consistent with closed-system, kinetic fractionation during Cl-H2O ligand exchange. Inter-species fractionation is assessed using time-series experiments beginning from the

  15. ASSESSMENT OF PAHS AND SELECTED PESTICIDES IN SHALLOW GROUNDWATER IN THE HIGHEST PROTECTED AREAS IN THE OPOLE REGION, POLAND

    Directory of Open Access Journals (Sweden)

    Mariusz Głowacki

    2014-04-01

    Full Text Available The ground water quality was determined after the analyses of water samples from 18 wells. The wells were in the Groundwater Area with the Highest Protection (Triassic water, Opole region, Poland, rural build up. The water table level was low: 0.5 – 18.0 m below the ground surface level (except for one artesian well. The following parameters were determined: pH, EC, colour, ammonium, nitrite, nitrate, dissolved orthophosphate, total phosphorus, dissolved oxygen, BOD, COD-Mn, COD-Cr, humic substances, chloride, sulphate, total hardness, alkalinity, dry residue PAHs (16 compounds, pesticides (6 compounds, however, only selected data were presented in this paper. In all the analysed water samples chloro-organic pesticides were observed. The analysed water contained heptachlor in the highest concentrations of 15.97 mg/dm3. Good quality water must not include concentrations higher than 0.5 mg/dm3 of heptachlor. However, the concentration was circa 32 times higher than this value. The second pesticide determining poor water quality is dieldrin. This compound in the investigated groundwater was 1.94 mg/dm3 – 4 times higher than the limit for acceptable quality ground water. The concentration of pesticides also changed over the course of the research; the concentration in the analysed groundwater in the same well changed quite dramatically over a period of 1 year. Although PAHs and pesticides are potentially toxic for biological organisms they do exist in the environment as a product of the natural biological transformation of organic matter. The noted concentrations and compositions of PAH compounds were different to natural PAHs. It confirms the fact that agricultural activity influences groundwater quality.

  16. Epitaxial Bi2 FeCrO6 Multiferroic Thin Film as a New Visible Light Absorbing Photocathode Material.

    Science.gov (United States)

    Li, Shun; AlOtaibi, Bandar; Huang, Wei; Mi, Zetian; Serpone, Nick; Nechache, Riad; Rosei, Federico

    2015-08-26

    Ferroelectric materials have been studied increasingly for solar energy conversion technologies due to the efficient charge separation driven by the polarization induced internal electric field. However, their insufficient conversion efficiency is still a major challenge. Here, a photocathode material of epitaxial double perovskite Bi(2) FeCrO(6) multiferroic thin film is reported with a suitable conduction band position and small bandgap (1.9-2.1 eV), for visible-light-driven reduction of water to hydrogen. Photoelectrochemical measurements show that the highest photocurrent density up to -1.02 mA cm(-2) at a potential of -0.97 V versus reversible hydrogen electrode is obtained in p-type Bi(2) FeCrO(6) thin film photocathode grown on SrTiO(3) substrate under AM 1.5G simulated sunlight. In addition, a twofold enhancement of photocurrent density is obtained after negatively poling the Bi(2) FeCrO(6) thin film, as a result of modulation of the band structure by suitable control of the internal electric field gradient originating from the ferroelectric polarization in the Bi(2) FeCrO(6) films. The findings validate the use of multiferroic Bi(2) FeCrO(6) thin films as photocathode materials, and also prove that the manipulation of internal fields through polarization in ferroelectric materials is a promising strategy for the design of improved photoelectrodes and smart devices for solar energy conversion. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Comparison of the microstructure and phase stability of as-cast, CAD/CAM and powder metallurgy manufactured Co-Cr dental alloys.

    Science.gov (United States)

    Li, Kai Chun; Prior, David J; Waddell, J Neil; Swain, Michael V

    2015-12-01

    The objective of this study was to identify the different microstructures produced by CC, PM and as-cast techniques for Co-Cr alloys and their phase stability following porcelain firings. Three bi-layer porcelain veneered Co-Cr specimens and one monolithic Co-Cr specimen of each alloy group [cast, powder metallurgy (PM), CAD/CAM (CC)] were manufactured and analyzed using electron backscatter diffraction (EBSD), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). Specimens were treated to incremental numbers of porcelain firings (control 0, 5, 15) with crystallographic data, grain size and chemical composition subsequently obtained and analyzed. EBSD datasets of the cast alloy indicated large grains >200 μm whereas PM and CC alloy consisted of mean arithmetic grain sizes of 29.6 μm and 19.2 μm respectively. XRD and EBSD results both indicated the highest increase in hcp content (>13vol%) for cast Co-Cr alloy after treatment with porcelain firing while PM and CC indicated .05) was observed in CC. EDS line scans indicated an increase in Cr content at the alloy surface after porcelain firing treatment for all three alloys. PM and CC produced alloy had superior fcc phase stability after porcelain firings compared to a traditional cast alloy. It is recommended that PM and CC alloys be used for porcelain-fused-to-metal restorations. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  18. Spin magnetic moments from single atoms to small Cr clusters

    Energy Technology Data Exchange (ETDEWEB)

    Boeglin, C.; Decker, R.; Bulou, H.; Scheurer, F.; Chado, I. [IPCMS-GSI - UMR 7504, 67037 Strasbourg Cedex (France); Ohresser, P. [LURE, 91405 Orsay (France); Dhesi, S.S. [ESRF, BP 220, 38043 Grenoble Cedex (France); Present permanent address: Diamond Light Source, Chilton, Didcot OX11 0QX (United Kingdom); Gaudry, E. [LMCP, 4, place Jussieu, 75252 Paris (France); Lazarovits, B. [CCMS, T.U. Vienna, Gumpendorfstr. 1a, 1060 Wien (Austria)

    2005-07-01

    Morphology studies at the first stages of the growth of Cr/Au(111) are reported and compared to the magnetic properties of the nanostructures. We analyze by Scanning Tunneling Microscopy and Low Energy Electron Diffraction the Cr clusters growth between 200 K and 300 K. In the early stages of the growth the morphology of the clusters shows monoatomic high islands located at the kinks of the herringbone reconstructed Au(111) surface. By X-ray Magnetic Circular Dichroism performed on the Cr L{sub 2,3} edges it is shown that the temperature dependent morphology strongly influences the magnetic properties of the Cr clusters. We show that in the sub-monolayer regime Cr clusters are antiferromagnetic and paramagnetic when the size reaches the atomic limit. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. A new derivation of the highest-weight polynomial of a unitary lie algebra

    International Nuclear Information System (INIS)

    P Chau, Huu-Tai; P Van, Isacker

    2000-01-01

    A new method is presented to derive the expression of the highest-weight polynomial used to build the basis of an irreducible representation (IR) of the unitary algebra U(2J+1). After a brief reminder of Moshinsky's method to arrive at the set of equations defining the highest-weight polynomial of U(2J+1), an alternative derivation of the polynomial from these equations is presented. The method is less general than the one proposed by Moshinsky but has the advantage that the determinantal expression of the highest-weight polynomial is arrived at in a direct way using matrix inversions. (authors)

  20. The Highest Good and the Practical Regulative Knowledge in Kant’s Critique of Practical Reason

    OpenAIRE

    Joel Thiago Klein

    2016-01-01

    In this paper I defend three different points: first, that the concept of highest good is derived from an a priori but subjective argument, namely a maxim of pure practical reason; secondly, that the theory regarding the highest good has the validity of a practical regulative knowledge; and thirdly, that the practical regulative knowledge can be understood as the same “holding something to be true” as Kant attributes to hope and believe.

  1. Robust Strategy for Crafting Li5Cr7Ti6O25@CeO2 Composites as High-Performance Anode Material for Lithium-Ion Battery.

    Science.gov (United States)

    Mei, Jie; Yi, Ting-Feng; Li, Xin-Yuan; Zhu, Yan-Rong; Xie, Ying; Zhang, Chao-Feng

    2017-07-19

    A facile strategy was developed to prepare Li 5 Cr 7 Ti 6 O 25 @CeO 2 composites as a high-performance anode material. X-ray diffraction (XRD) and Rietveld refinement results show that the CeO 2 coating does not alter the structure of Li 5 Cr 7 Ti 6 O 25 but increases the lattice parameter. Scanning electron microscopy (SEM) indicates that all samples have similar morphologies with a homogeneous particle distribution in the range of 100-500 nm. Energy-dispersive spectroscopy (EDS) mapping and high-resolution transmission electron microscopy (HRTEM) prove that CeO 2 layer successfully formed a coating layer on a surface of Li 5 Cr 7 Ti 6 O 25 particles and supplied a good conductive connection between the Li 5 Cr 7 Ti 6 O 25 particles. The electrochemical characterization reveals that Li 5 Cr 7 Ti 6 O 25 @CeO 2 (3 wt %) electrode shows the highest reversibility of the insertion and deinsertion behavior of Li ion, the smallest electrochemical polarization, the best lithium-ion mobility among all electrodes, and a better electrochemical activity than the pristine one. Therefore, Li 5 Cr 7 Ti 6 O 25 @CeO 2 (3 wt %) electrode indicates the highest delithiation and lithiation capacities at each rate. At 5 C charge-discharge rate, the pristine Li 5 Cr 7 Ti 6 O 25 only delivers an initial delithiation capacity of ∼94.7 mAh g -1 , and the delithiation capacity merely achieves 87.4 mAh g -1 even after 100 cycles. However, Li 5 Cr 7 Ti 6 O 25 @CeO 2 (3 wt %) delivers an initial delithiation capacity of 107.5 mAh·g -1 , and the delithiation capacity also reaches 100.5 mAh g -1 even after 100 cycles. The cerium dioxide modification is a direct and efficient approach to improve the delithiation and lithiation capacities and cycle property of Li 5 Cr 7 Ti 6 O 25 at large current densities.

  2. LET calibration for CR-39 detectors in different oxygen environments

    International Nuclear Information System (INIS)

    Zhou, D.; Semones, E.; Weyland, M.; Benton, E.R.

    2007-01-01

    High LET (linear energy transfer) radiation is the main contributor to the radiation field in low Earth orbit (LEO) in terms of dose equivalent. CR-39 plastic nuclear track detectors (PNTDs) can measure the LET spectrum and charge spectrum for the complicated radiation field in space. Previous research indicated that the sensitivity of CR-39 is different for CR-39 PNTDs working in different oxygen environments. LET calibration for CR-39 detectors in different oxygen environments is needed. Almost all the previous LET calibration work was carried out for CR-39 detectors in good-oxygen condition, LET calibration work for CR-39 in poor-oxygen condition has not been conducted until our work. Systematic LET calibrations were carried out by JSC-SRAG (Space Radiation Analysis Group) for CR-39 detectors working in different oxygen environments and abundant results of LET calibrations were obtained. This paper introduces the method for CR-39 LET calibration, presents and discusses the calibration results and some applications

  3. Influence of temperature on Yb:YAG/Cr:YAG microchip laser operation

    Science.gov (United States)

    Šulc, Jan; Eisenschreiber, Jan; Jelínková, Helena; Nejezchleb, Karel; Å koda, Václav

    2017-02-01

    The goal of this work was an investigation of the temperature influence (in range from 80 up to 320 K) on the laser properties of Yb:YAG/Cr:YAG Q-switched diode-pumped microchip laser. This laser was based on monolith crystal (diameter 3mm) which combines in one piece an active laser part (Yb:YAG crystal, 10 at.% Yb/Y, 3mm long) and saturable absorber (Cr:YAG crystal, 1.36mm long, initial transmission 90% @ 1031 nm). The laser resonator pump mirror (HT for pump radiation, HR for generated radiation) was directly deposited on the Yb:YAG monolith part. The output coupler with reflection 55% for the generated wavelength was placed on the Cr:YAG part. The microchip laser was placed in the temperature controlled cupreous holder inside vacuum chamber of the liquid nitrogen cryostat. For Yb:YAG part longitudinal pulsed pumping (pumping pulse length 2.5 ms, rep-rate 20 Hz, power amplitude 21W) a fibre coupled (core diameter 400 μm, NA= 0:22) laser diode, operating at wavelength 933 nm, was used. The microchip laser mean output power, pulse duration, repetition rate, emission wavelength, and laser beam profile were measured in dependence on temperature. The generated pulse length was in range from 2.2 ns to 1.1 ns (FWHM) with the minimum at 230 K. The single pulse energy was peaking (0.4 mJ) at 180 K. The highest peak power (325 kW) was obtained at 220 K. The highest pulse repetition rate (38 kHz) and output mean power (370mW) was reached for temperature 80 K.

  4. [The gender gap in highest quality medical research - A scientometric analysis of the representation of female authors in highest impact medical journals].

    Science.gov (United States)

    Bendels, Michael H K; Wanke, Eileen M; Benik, Steffen; Schehadat, Marc S; Schöffel, Norman; Bauer, Jan; Gerber, Alexander; Brüggmann, Dörthe; Oremek, Gerhard M; Groneberg, David A

    2018-05-01

     The study aims to elucidate the state of gender equality in high-impact medical research, analyzing the representation of female authorships from January, 2008 to September, 2017.  133 893 male and female authorships from seven high-impact medical journals were analyzed. The key methodology was the combined analysis of the relative frequency, odds ratio and citations of female authorships. The Prestige Index measures the distribution of prestigious authorships between the two genders.  35.0 % of all authorships and 34.3 % of the first, 36.1 % of the co- and 24.2 % of the last authorships were held by women. Female authors have an odds ratio of 0.97 (KI: 0.93 - 1.01) for first, 1.36 (KI: 1.32 - 1.40) for co- und 0.57 (KI: 0.54 - 0.60) for last authorships compared to male authors. The proportion of female authorships exhibits an annual growth of 1.3 % overall, with 0.5 % for first, 1.2 % for co-, and 0.8 % for last authorships. Women are underrepresented at prestigious authorship compared to men (Prestige Index = -0.38). The underrepresentation accentuates in highly competitive articles attracting the highest citation rates, namely, articles with many authors and articles that were published in highest-impact journals. Multi-author articles with male key authors are more frequently cited than articles with female key authors. The gender-specific differences in citation rates increase the more authors contribute to an article. Women publish fewer articles compared to men (39.6 % female authors are responsible for 35.0 % of the authorships) and are underrepresented at productivity levels of more than 1 article per author. Distinct differences at the country level were revealed.  High impact medical research is characterized by few female group leaders as last authors and many female researchers being first or co-authors early in their career. It is very likely that this gender-specific career dichotomy will persistent in

  5. Energy

    International Nuclear Information System (INIS)

    Meister, F.; Ott, F.

    2002-01-01

    This chapter gives an overview of the current energy economy in Austria. The Austrian political aims of sustainable development and climate protection imply a reorientation of the Austrian energy policy as a whole. Energy consumption trends (1993-1998), final energy consumption by energy carrier (indexed data 1993-1999), comparative analysis of useful energy demand (1993 and 1999) and final energy consumption of renewable energy sources by sector (1996-1999) in Austria are given. The necessary measures to be taken in order to reduce the energy demand and increased the use of renewable energy are briefly mentioned. Figs. 5. (nevyjel)

  6. Dipole model analysis of highest precision HERA data, including very low Q"2's

    International Nuclear Information System (INIS)

    Luszczak, A.; Kowalski, H.

    2016-12-01

    We analyse, within a dipole model, the final, inclusive HERA DIS cross section data in the low χ region, using fully correlated errors. We show, that these highest precision data are very well described within the dipole model framework starting from Q"2 values of 3.5 GeV"2 to the highest values of Q"2=250 GeV"2. To analyze the saturation effects we evaluated the data including also the very low 0.35< Q"2 GeV"2 region. The fits including this region show a preference of the saturation ansatz.

  7. Energy

    International Nuclear Information System (INIS)

    Meister, F.

    2001-01-01

    This chapter of the environmental control report deals with the environmental impact of energy production, energy conversion, atomic energy and renewable energy. The development of the energy consumption in Austria for the years 1993 to 1999 is given for the different energy types. The development of the use of renewable energy sources in Austria is given, different domestic heat-systems are compared, life cycles and environmental balance are outlined. (a.n.)

  8. Partially filled intermediate band of Cr-doped GaN films

    International Nuclear Information System (INIS)

    Sonoda, S.

    2012-01-01

    We investigated the band structure of sputtered Cr-doped GaN (GaCrN) films using optical absorption, photoelectron yield spectroscopy, and charge transport measurements. It was found that an additional energy band is formed in the intrinsic band gap of GaN upon Cr doping, and that charge carriers in the material move in the inserted band. Prototype solar cells showed enhanced short circuit current and open circuit voltage in the n-GaN/GaCrN/p-GaN structure compared to the GaCrN/p-GaN structure, which validates the proposed concept of an intermediate-band solar cell.

  9. Electrochemical Reduction of Oxygen and Nitric oxide at low Temperature on La1-xSrxCr0.97V0.03O3-δ Cathodes

    DEFF Research Database (Denmark)

    Kammer Hansen, Kent

    2013-01-01

    Five La1-xSrxCr0.97V0.03O3-δ (x = 0, 0.05, 0.15, 0.25, 0.35) perovskites were synthesized and characterized by powder XRD and cyclic voltammetry on cone-shaped electrodes in 10% oxygen in argon or 1% nitric oxide in argon at 200, 300 and 400°C. It was shown that the activation energy for the redu......Five La1-xSrxCr0.97V0.03O3-δ (x = 0, 0.05, 0.15, 0.25, 0.35) perovskites were synthesized and characterized by powder XRD and cyclic voltammetry on cone-shaped electrodes in 10% oxygen in argon or 1% nitric oxide in argon at 200, 300 and 400°C. It was shown that the activation energy...... for the reduction of oxygen is higher than the activation energy for the reduction nitric oxide. The activity for the reduction of both oxygen and nitric oxide was shown to be highest for the end member La0.65Sr0.35Cr0.97V0.03O3-δ. The highest ratio between the current densities in the nitric oxide and oxygen...... containing atmospheres was found for the end member LaCr0.97V0.03O3-δ. The chromites also showed activity as anodes for either oxygen evolution or oxidation of nitric oxide to nitrogen dioxide....

  10. Alpha-particle response characteristics of CR-39

    International Nuclear Information System (INIS)

    Abou El-Khier, A.A.; Gaber, M.; El-Khatib, A.M.; Fawzy, M.A.

    1987-01-01

    The form of the response curve of the polycarbonate CR-39 for α-particles at relatively low energies has been established. The investigation included measurements of both bulk- and track-etch rates. The latter was measured as a function of α-particle energies. (author)

  11. On the crystal structure of Z-phase Cr(V,Nb)N

    DEFF Research Database (Denmark)

    Danielsen, Hilmar Kjartansson; Hald, John; Grumsen, Flemming Bjerg

    2006-01-01

    The Z-phase Cr(YNb)N particles in various 9 to 12 pct Cr creep-resistant steels were investigated with electron diffraction, energy dispersive spectroscopy (EDS), and electron energy loss spectroscopy(EELS). In addition to the well-known tetragonal crystal structure for Z phase, a cubic crystal s...

  12. Alpha-1-antitrypsin deficiency in Madeira (Portugal): the highest prevalence in the world.

    Science.gov (United States)

    Spínola, Carla; Bruges-Armas, Jácome; Pereira, Conceição; Brehm, António; Spínola, Hélder

    2009-10-01

    Alpha-1-antitrypsin (AAT) deficiency is a common genetic disease which affects both lung and liver. Early diagnosis can help asymptomatic patients to adjust their lifestyle choices in order to reduce the risk of Chronic Obstructive Pulmonary Disease (COPD). The determination of this genetic deficiency prevalence in Madeira Island (Portugal) population is important to clarify susceptibility and define the relevance of performing genetic tests for AAT on individuals at risk for COPD. Two hundred samples of unrelated individuals from Madeira Island were genotyped for the two most common AAT deficiency alleles, PI*S and PI*Z, using Polymerase Chain Reaction-Mediated Site-Directed Mutagenesis. Our results show one of the highest frequencies for both mutations when compared to any already studied population in the world. In fact, PI*S mutation has the highest prevalence (18%), and PI*Z mutation (2.5%) was the third highest worldwide. The frequency of AAT deficiency genotypes in Madeira (PI*ZZ, PI*SS, and PI*SZ) is estimated to be the highest in the world: 41 per 1000. This high prevalence of AAT deficiency on Madeira Island reveals an increased genetic susceptibility to COPD and suggests a routine genetic testing for individuals at risk.

  13. Phase stability and elastic properties of Cr-V alloys

    Science.gov (United States)

    Gao, M. C.; Suzuki, Y.; Schweiger, H.; Doǧan, Ö. N.; Hawk, J.; Widom, M.

    2013-02-01

    V is the only element in the periodic table that forms a complete solid solution with Cr and thus is particularly important in alloying strategy to ductilize Cr. This study combines first-principles density functional theory calculations and experiments to investigate the phase stability and elastic properties of Cr-V binary alloys. The cluster expansion study reveals the formation of various ordered compounds at low temperatures that were not previously known. These compounds become unstable due to the configurational entropy of bcc solid solution as the temperature is increased. The elastic constants of ordered and disordered compounds are calculated at both T = 0 K and finite temperatures. The overall trends in elastic properties are in agreement with measurements using the resonant ultrasound spectroscopy method. The calculations predict that addition of V to Cr decreases both the bulk modulus and the shear modulus, and enhances the Poisson’s ratio, in agreement with experiments. Decrease in the bulk modulus is correlated to decrease in the valence electron density and increase in the lattice constant. An enhanced Poisson’s ratio for bcc Cr-V alloys (compared to pure Cr) is associated with an increased density of states at the Fermi level. Furthermore, the difference charge density in the bonding region in the (110) slip plane is highest for pure Cr and decreases gradually as V is added. The present calculation also predicts a negative Cauchy pressure for pure Cr, and it becomes positive upon alloying with V. The intrinsic ductilizing effect from V may contribute, at least partially, to the experimentally observed ductilizing phenomenon in the literature.

  14. Micro calcification evaluation using CR plates in computerized mammography

    International Nuclear Information System (INIS)

    Bustos F, M.; Prata M, A.

    2017-10-01

    Cancer is one of the leading causes of mortality in the world. In 2012, about 14 million new cases were registered, of which 1.6 million are breast cancer, according to the World Health Organization. The National Cancer Institute of Brazil estimated 57 thousand new cases of breast cancer by 2016. Mammography is the imaging technique most used worldwide for the early diagnosis of breast cancer. Computed radiography (CR) plates are used for digital radiography, and are widely used to obtain digital mammograms. This work aims to evaluate te response of CR plates to the variation of exposure in mammography equipment. Three CR plates for mammography of different models were used for the study. X-ray beams were selected to perform successive exposures of CR plates by varying the exposure time. These exposures were performed to obtain raw images that were subsequently analyzed using ImageJ software, from which the value of intensity recorded in the central region of each image was obtained, correlating it with the exposure time. From these data the necessary correlations were made to determine the exposure time for which the CR plate begins to saturate, observing that the saturation occurs first for the highest value of the applied voltage. Finally, successive exposures of the CR plate were made using the compressed breast simulator made of acrylic plates and containing microcalcifications of different sizes to determine the qualitative resolution of CR plates, observing that only microcalcifications above 177 μm are visible in the image. The knowledge of saturation characteristics and resolution of the CR plate allows the selection of more adequate parameters to work without approaching the saturation region. (Author)

  15. Micro calcification evaluation using CR plates in computerized mammography

    Energy Technology Data Exchange (ETDEWEB)

    Bustos F, M.; Prata M, A., E-mail: mabelita.bfm@gmail.com [Federal University of Minas Gerais, School of Engineering, Department of Nuclear Engineering, Av. Antonio Carlos CEP 131270-901 Belo Horizonte, Minas Gerais (Brazil)

    2017-10-15

    Cancer is one of the leading causes of mortality in the world. In 2012, about 14 million new cases were registered, of which 1.6 million are breast cancer, according to the World Health Organization. The National Cancer Institute of Brazil estimated 57 thousand new cases of breast cancer by 2016. Mammography is the imaging technique most used worldwide for the early diagnosis of breast cancer. Computed radiography (CR) plates are used for digital radiography, and are widely used to obtain digital mammograms. This work aims to evaluate te response of CR plates to the variation of exposure in mammography equipment. Three CR plates for mammography of different models were used for the study. X-ray beams were selected to perform successive exposures of CR plates by varying the exposure time. These exposures were performed to obtain raw images that were subsequently analyzed using ImageJ software, from which the value of intensity recorded in the central region of each image was obtained, correlating it with the exposure time. From these data the necessary correlations were made to determine the exposure time for which the CR plate begins to saturate, observing that the saturation occurs first for the highest value of the applied voltage. Finally, successive exposures of the CR plate were made using the compressed breast simulator made of acrylic plates and containing microcalcifications of different sizes to determine the qualitative resolution of CR plates, observing that only microcalcifications above 177 μm are visible in the image. The knowledge of saturation characteristics and resolution of the CR plate allows the selection of more adequate parameters to work without approaching the saturation region. (Author)

  16. Cr3+ and Cr4+ luminescence in glass ceramic silica

    International Nuclear Information System (INIS)

    Martines, Marco A.U.; Davolos, Marian R.; Jafelicci, Miguel Junior; Souza, Dione F. de; Nunes, Luiz A.O.

    2008-01-01

    This paper reports on the effect of glass ceramic silica matrix on [CrO 4 ] 4- and Cr 2 O 3 NIR and visible luminescence. Chromium-containing silica was obtained by precipitation from water-glass and chromium nitrate acid solution with thermal treatment at 1000 deg. C. From XRD results silica and silica-chromium samples are crystalline. The chromium emission spectrum presents two main broad bands: one in the NIR region (1.1-1.7μm) and other in the visible region (0.6-0.7μm) assigned to Cr 4+ and to Cr 3+ , respectively. This thermal treated glass ceramic silica-chromium sample stabilizes the [CrO 4 ] 4- where Cr 4+ substitutes for Si 4+ and also hexacoordinated Cr 3+ group probably as segregated phase in the system. It can be pointed out that luminescence spectroscopy is a powerful tool for detecting the two chromium optical centers in the glass ceramic silica

  17. Influence of N2/Ar Flow Ratio on Microstructure and Properties of the AlCrSiN Coatings Deposited by High-Power Impulse Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    Bai-Song Li

    2017-12-01

    Full Text Available The cutting properties of tools can be greatly improved by AlCrSiN coatings. The AlCrSiN coatings with nitrogen content in the range of 28.2–56.3 at.% were prepared by varying the N2/Ar flow ratio from 1/4 to 1/1. The influence of N2/Ar flow ratio on composition, microstructure, and mechanical properties, as well as the tribological properties, of the coatings was investigated. With increasing N content, the coating microstructure gradually evolved from single fcc-(Cr,AlN (200 phase to the mixture of fcc-(Cr,AlN and hcp-(Cr,AlN phase, which corresponds to an increased crystallinity within the coatings. The coating presents the highest hardness and best wear resistance for an N2/Ar flow ratio of 1/1, but the film adhesive strength and inner stress decreased obviously with increasing N2/Ar flow ratio, which was attributed to the rapid reduction of particle kinetic energy induced by the obstruction of neutral nitride particles between target and substrates. The highest H3/E*2 value exhibited the lowest wear rate, at 0.81 × 10−14 m3/(N·m, indicating that it had the best resistance to plastic deformation. The main wear mechanisms of the as-deposited coatings were abrasive wear and adhesive wear. The increasing crystallinity of the interior coatings resulted in higher hardness and better tribological behavior with an increase in N2/Ar flow ratio.

  18. Effect of Ti/Cr additive on helium diffusion and segregation in dilute vanadium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Tingting [Information Science and Technology College, Dalian Maritime University, Dalian 116026 (China); Zhang, Pengbo, E-mail: zhangpb@dlmu.edu.cn [Department of Physics, Dalian Maritime University, Dalian 116026 (China); Zhao, Jijun [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Zheng, Pengfei; Chen, Jiming [Southwestern Institute of Physics, Chengdu 610041 (China)

    2017-02-15

    Highlights: • He prefers to segregate to Ti region rather than Cr region in the vanadium alloys. • He diffusion barrier decreases towards Ti while it increases towards Cr. • The He{sub n}Ti complexes are more stable than the He{sub n}Cr complexes energetically. - Abstract: The effect of Ti/Cr additive on He diffusion and segregation properties in dilute vanadium alloys is investigated using first-principles calculations. First we determined the He preference site and investigated the He-Cr/He-Ti interactions. Energetically, He prefers to segregate to Ti regions rather than Cr regions. The most stable site for interstitial He is a tetrahedral site near Ti. He-Ti interactions have a weak attraction while He-Cr interactions have a weak repulsion. Kinetically, He diffusion to Ti has a lower energy barrier; contrarily the He barrier increases towards Cr. Furthermore, we discuss the stability of He{sub n}-Cr/Ti complexes and He{sub n}-vacancy-Cr and Ti complexes with n = 1–8. It is found that the He{sub n}Ti complexes are more stable than the He{sub n}Cr complexes while the He{sub n}-vacancy-Ti complexes are less favorable than He{sub n}-vacancy-Cr. The findings give a reference for understanding the mechanism of He embrittlement under irradiation.

  19. Thin film nano-photocatalyts with low band gap energy for gas phase degradation of p-xylene: TiO2 doped Cr, UiO66-NH2 and LaBO3 (B  =  Fe, Mn, and Co)

    Science.gov (United States)

    Loc Luu, Cam; Thuy Van Nguyen, Thi; Nguyen, Tri; Nguyen, Phung Anh; Hoang, Tien Cuong; Ha, Cam Anh

    2018-03-01

    By dip-coating technique the thin films of nano-photocatalysts TiO2, Cr-doped TiO2, LaBO3 perovskites (B  =  Fe, Mn, and Co) prepared by sol-gel method, and UiO66-NH2 prepared by a solvothermal were obtained and employed for gas phase degradation of p-xylene. Physicochemical characteristics of the catalysts were examined by the methods of BET, SEM, TEM, XRD, FT-IR, TGA, Raman and UV-vis spectroscopies. The thickness of film was determined by a Veeco-American Dektek 6M instrument. The activity of catalysts was evaluated in deep photooxidation of p-xylene in a microflow reactor at room temperature with the radiation sources of a UV (λ  =  365 nm) and LED lamps (λ  =  400-510 nm). The obtained results showed that TiO2 and TiO2 doped Cr thin films was featured by an anatase phase with nanoparticles of 10-100 nm. Doping TiO2 with 0.1%mol Cr2O3 led to reduce band gap energy from 3.01 down to 1.99 eV and extend the spectrum of photon absorption to the visible region (λ  =  622 nm). LaBO3 perovkite thin films were also featured by a crystal phase with average particle nanosize of 8-40 nm, a BET surface area of 17.6-32.7 m2 g-1 and band gap energy of 1.87-2.20 eV. UiO66-NH2 was obtained in the ball shape of 100-200 nm, a BET surface area of 576 m2 g-1 and a band gap energy of 2.83 eV. The low band gap energy nano-photocatalysts based on Cr-doped TiO2 and LaBO3 perovskites exhibited highly stable and active for photo-degradation of p-xylene in the gas phase under radiation of UV-vis light. Perovskite LaFeO3 and Cr-TiO2 thin films were the best photocatalysts with a decomposition yield being reached up to 1.70 g p-xylene/g cat.

  20. CrN/AlN superlattice coatings synthesized by pulsed closed field unbalanced magnetron sputtering with different CrN layer thicknesses

    International Nuclear Information System (INIS)

    Lin Jianliang; Moore, John J.; Mishra, Brajendra; Pinkas, Malki; Zhang Xuhai; Sproul, William D.

    2009-01-01

    CrN/AlN superlattice coatings with different CrN layer thicknesses were prepared using a pulsed closed field unbalanced magnetron sputtering system. A decrease in the bilayer period from 12.4 to 3.0 nm and simultaneously an increase in the Al/(Cr + Al) ratio from 19.1 to 68.7 at.% were obtained in the CrN/AlN coatings when the Cr target power was decreased from 1200 to 200 W. The bilayer period and the structure of the coatings were characterized by means of low angle and high angle X-ray diffraction and transmission electron microscopy. The mechanical and tribological properties of the coatings were studied using the nanoindentation and ball-on-disc wear tests. It was found that CrN/AlN superlattice coatings synthesized in the current study exhibited a single phase face-centered cubic structure with well defined interfaces between CrN and AlN nanolayers. Decreases in the residual stress and the lattice parameter were identified with a decrease in the CrN layer thickness. The hardness of the coatings increased with a decrease in the bilayer period and the CrN layer thickness, and reached the highest value of 42 GPa at a bilayer period of 4.1 nm (CrN layer thickness of 1.5 nm, AlN layer thickness of 2.5 nm) and an Al/(Cr + Al) ratio of 59.3 at.% in the coatings. A low coefficient of friction of 0.35 and correspondingly low wear rate of 7 x 10 -7 mm 3 N -1 m -1 were also identified in this optimized CrN/AlN coating when sliding against a WC-6%Co ball.

  1. Highest manageable level of radioactivity in the waste storage facilities of power plants

    International Nuclear Information System (INIS)

    Elkert, J.; Lennartsson, R.

    1991-01-01

    This project presents and discusses an investigation of the highest level of radioactivity possible to handle in the waste storage facilities. The amount of radioactivity, about 0.1% of the fuel inventory, is the same in both of the cases but the amount of water is very different. The hypothetical accident was supposed to be damage of the reactor fuel caused by loss of coolant. (K.A.E.)

  2. Highest cited papers published in Neurology India: An analysis for the years 1993-2014.

    Science.gov (United States)

    Pandey, Paritosh; Subeikshanan, V; Madhugiri, Venkatesh S

    2016-01-01

    The highest cited papers published in a journal provide a snapshot of the clinical practice and research in that specialty and/or region. The aim of this study was to determine the highest cited papers published in Neurology India and analyze their attributes. This study was a citation analysis of all papers published in Neurology India since online archiving commenced in 1993. All papers published in Neurology India between the years 1993-2014 were listed. The number of times each paper had been cited up till the time of performing this study was determined by performing a Google Scholar search. Published papers were then ranked on the basis of total times cited since publication and the annual citation rate. Statistical Techniques: Simple counts and percentages were used to report most results. The mean citations received by papers in various categories were compared using the Student's t-test or a one-way analysis of variance, as appropriate. All analyses were carried out on SAS University Edition (SAS/STAT®, SAS Institute Inc, NC, USA) and graphs were generated on MS Excel 2016. The top papers on the total citations and annual citation rate rank lists pertained to basic neuroscience research. The highest cited paper overall had received 139 citations. About a quarter of the papers published had never been cited at all. The major themes represented were vascular diseases and infections. The highest cited papers reflect the diseases that are of major concern in India. Certain domains such as trauma, allied neurosciences, and basic neuroscience research were underrepresented.

  3. ATLAS event at 13 TeV - Highest mass dijets resonance event in 2015 data

    CERN Multimedia

    ATLAS Collaboration

    2015-01-01

    The highest-mass, central dijet event passing the dijet resonance selection collected in 2015 (Event 1273922482, Run 280673) : the two central high-pT jets have an invariant mass of 6.9 TeV, the two leading jets have a pT of 3.2 TeV. The missing transverse momentum in this event is 46 GeV.

  4. ATLAS event at 13 TeV - Highest mass dijets angular event in 2015 data

    CERN Multimedia

    ATLAS Collaboration

    2015-01-01

    The highest-mass dijet event passing the angular selection collected in 2015 (Event 478442529, Run 280464): the two central high-pT jets have an invariant mass of 7.9 TeV, the three leading jets have a pT of 1.99, 1.86 and 0.74 TeV respectively. The missing transverse momentum in this event is 46 GeV

  5. α-cluster states in {sup 46,54}Cr from double-folding potentials

    Energy Technology Data Exchange (ETDEWEB)

    Mohr, Peter [Diakonie-Klinikum, Schwaebisch Hall (Germany); Institute for Nuclear Research (Atomki), Debrecen (Hungary)

    2017-10-15

    α-cluster states in {sup 46}Cr and {sup 54}Cr are investigated in the double-folding model. This study complements a recent similar work by Souza and Miyake, Eur. Phys. J. A 53, 146 (2017), which was based on a specially shaped potential. Excitation energies, reduced widths, intercluster separations, and intra-band transition strengths are calculated and compared to experimental values for the ground state bands in {sup 46}Cr and {sup 54}Cr. The α-cluster potential is also applied to elastic scattering at low and intermediate energies. Here, as a byproduct, a larger radial extent of the neutron density in {sup 50}Ti is found. (orig.)

  6. Analysis of precipitation in a Cu-Cr-Zr alloy

    Institute of Scientific and Technical Information of China (English)

    Zhao Mei; Lin Guobiao; Wang Zidong; Zhang Maokui

    2008-01-01

    Precipites in Cu-0.42%Cr-0.21%Zr alloy were analyzed by using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDXS) and transmission electron microscope (TEM). After the solid solution was performed at 980℃ for 2 h, water-quenched and aged at 450℃ for 20 h, the precipite had a bimodal distribution of precipitate size. The coarse precipitates are pure Cr and Cu5Zr, the dispersed fine precipitate is CrCu2(Zr, Mg) and pure Cr ranging from 1 to 50 nm. The coarse phases formed during solidification and were left undissolved during solid solution. The fine precipitates are the hardening precipitates that form due to decomposition of the supersaturated solid solution during aging.

  7. Energy

    International Nuclear Information System (INIS)

    Bobin, J.L.

    1996-01-01

    Object of sciences and technologies, energy plays a major part in economics and relations between nations. Jean-Louis Bobin, physicist, analyses the relations between man and energy and wonders about fears that delivers nowadays technologies bound to nuclear energy and about the fear of a possible shortage of energy resources. (N.C.). 17 refs., 14 figs., 2 tabs

  8. Eyebrow hairs from actinic keratosis patients harbor the highest number of cutaneous human papillomaviruses.

    Science.gov (United States)

    Schneider, Ines; Lehmann, Mandy D; Kogosov, Vlada; Stockfleth, Eggert; Nindl, Ingo

    2013-04-24

    Cutaneous human papillomavirus (HPV) infections seem to be associated with the onset of actinic keratosis (AK). This study compares the presence of cutaneous HPV types in eyebrow hairs to those in tissues of normal skin and skin lesions of 75 immunocompetent AK patients. Biopsies from AK lesions, normal skin and plucked eyebrow hairs were collected from each patient. DNA from these specimens was tested for the presence of 28 cutaneous HPV (betaPV and gammaPV) by a PCR based method. The highest number of HPV prevalence was detected in 84% of the eyebrow hairs (63/75, median 6 types) compared to 47% of AK lesions (35/75, median 3 types) (pAK and 69 in normal skin. In all three specimens HPV20, HPV23 and/or HPV37 were the most prevalent types. The highest number of multiple types of HPV positive specimens was found in 76% of the eyebrow hairs compared to 60% in AK and 57% in normal skin. The concordance of at least one HPV type in virus positive specimens was 81% (three specimens) and 88-93% of all three combinations with two specimens. Thus, eyebrow hairs revealed the highest number of cutaneous HPV infections, are easy to collect and are an appropriate screening tool in order to identify a possible association of HPV and AK.

  9. Density of Liquid Ni-Cr Alloy

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The density of liquid Ni-Cr alloy was measured by a modified sessile drop method. The density of liquid Ni-Cr alloywas found to decrease with increasing temperature and Cr concentration in the alloy. The molar volume of liquidNi-Cr alloy increases with increasing the Cr concentration in the alloy. The molar volume of Ni-Cr alloy determinedin the present work shows a positive deviation from the linear molar volume.

  10. HFO operation with CR injection

    Energy Technology Data Exchange (ETDEWEB)

    Poensgen, Christian [MAN-Diesel und Turbo SE, Augsburg (Germany)

    2011-07-01

    In 1996 MAN Diesel and Turbo SE started the development of a CR-system for medium speed engines for HFO operation up to fuel viscosity of 700 cSt. 2004 the first field test engine, a 7L 32/40 GenSet was put into service as a retrofit and collected up to now more than 20.000 running hours operated on HFO on a large container vessel. Meanwhile several L32/40 CR GenSets, L32/44 CR, V48/60 CR and L21/31 CR engines collected more than 100000 running hours in HFO operation before MAN Diesel started up the serial production of the new 32/44 CR and 48/60 CR engines. All of these engines are still in service. The paper will give an overview about the field experience and countermeasures which were necessary to develop a reliable product which fulfills the customers' demands concerning low fuel oil consumption, invisible smoke over the whole load range, low emission levels and maintenance costs. The experience was made in a wide range of applications such as GenSet, Cruise Vessel main propulsion and ferry main propulsion running 24h/day. The field test engines reached an availability of more than 90% per year. The paper also will point out the win/win situation for the the manufacturer and customer to participate in the development of the CR technology. For customers satisfaction MAN Diesel provides help for easy handling like online access per satellite connection, easy leakage detection and operator training at site or at the new built academies. The flexibility of the CR-system is the base frame for the future development of engines which fulfills IMO TIER II and IMO TIER III with high efficiency. The necessary reliability, a must, has been proven in the field under real conditions. (orig.)

  11. Potential Remedies for the High Synchrotron-Radiation-Induced Heat Load for Future Highest-Energy-Proton Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2084568; Baglin, Vincent; Schaefers, Franz

    2015-01-01

    We propose a new method for handling the high synchrotron radiation (SR) induced heat load of future circular hadron colliders (like FCC-hh). FCC-hh are dominated by the production of SR, which causes a significant heat load on the accelerator walls. Removal of such a heat load in the cold part of the machine, as done in the Large Hadron Collider, will require more than 100 MW of electrical power and a major cooling system. We studied a totally different approach, identifying an accelerator beam screen whose illuminated surface is able to forward reflect most of the photons impinging onto it. Such a reflecting beam screen will transport a significant part of this heat load outside the cold dipoles. Then, in room temperature sections, it could be more efficiently dissipated. Here we will analyze the proposed solution and address its full compatibility with all other aspects an accelerator beam screen must fulfill to keep under control beam instabilities as caused by electron cloud formation, impedance, dynamic...

  12. Energy

    CERN Document Server

    Foland, Andrew Dean

    2007-01-01

    Energy is the central concept of physics. Unable to be created or destroyed but transformable from one form to another, energy ultimately determines what is and isn''t possible in our universe. This book gives readers an appreciation for the limits of energy and the quantities of energy in the world around them. This fascinating book explores the major forms of energy: kinetic, potential, electrical, chemical, thermal, and nuclear.

  13. Microstructure and damage behavior of W-Cr alloy under He irradiation

    Science.gov (United States)

    Huang, Ke; Luo, Lai-Ma; Zan, Xiang; Xu, Qiu; Liu, Dong-Guang; Zhu, Xiao-Yong; Cheng, Ji-Gui; Wu, Yu-Cheng

    2018-04-01

    In this study, a large-power inductively coupled plasma source was designed to perform the continuous helium ion irradiations of W-Cr binary alloy (W-20 wt%Cr) under relevant conditions of the International Thermonuclear Experimental Reactor. Surface damages and microstructures of irradiated W-20Cr were observed by using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy. The addition of Cr dramatically enhanced the micro-hardness of the obtained bulk materials, and the interface between the W matrix and the second phase Cr-O is a semi-coherent interface. After irradiation, the doping of Cr element effectively reduces the damage of the W matrix during the irradiation process. The semi-coherent interface between the second phase and the W matrix improves the anti-irradiation performance of the W-20Cr alloy.

  14. Comparison of the Otto Bock solid ankle cushion heel foot with wooden keel to the low-cost CR-Equipements™ solid ankle cushion heel foot with polypropylene keel: A randomized prospective double-blind crossover study assessing patient satisfaction and energy expenditure.

    Science.gov (United States)

    Lacraz, Alain; Armand, Stéphane; Turcot, Katia; Carmona, Gorki; Stern, Richard; Borens, Olivier; Assal, Mathieu

    2017-06-01

    The International Committee of the Red Cross supports a worldwide program of prosthetic fitting and rehabilitation. In this context, a prosthetic foot was developed and widely distributed in least developed countries. Prospective, randomized, double-blind, controlled study. To compare patient satisfaction and energy expenditure during ambulation between a low-cost prosthetic foot designed with a polypropylene keel (CR-Equipements ™ solid ankle cushion heel, International Committee of the Red Cross) to a well-recognized solid ankle cushion heel foot with a wooden keel (solid ankle cushion heel foot, Otto Bock). A total of 15 participants with unilateral transtibial amputation were evaluated using the two prosthetic feet in a randomized prospective double-blind crossover study. Main outcomes were patient satisfaction questionnaires (Satisfaction with Prosthesis Questionnaire and prosthetic foot satisfaction) and energy expenditure (oxygen consumption-mL/kg/min, oxygen cost-mL/kg/m, and heart rate-bpm). There were no significant differences between the two prosthetic feet for satisfaction and energy expenditure. The low-cost solid ankle cushion heel foot with polypropylene keel provides comparable satisfaction and similar energy expenditure as the solid ankle cushion heel foot with wooden keel. Clinical relevance The results of this study support the application and widespread use of the CR-Equipements ™ solid ankle cushion heel foot. From a cost-effectiveness standpoint, patients are well satisfied and exhibit similar outcomes at a substantially lower cost.

  15. High Temperature Behavior of Cr3C2-NiCr Coatings in the Actual Coal-Fired Boiler Environment

    Science.gov (United States)

    Bhatia, Rakesh; Sidhu, Hazoor Singh; Sidhu, Buta Singh

    2015-03-01

    Erosion-corrosion is a serious problem observed in steam-powered electricity generation plants, and industrial waste incinerators. In the present study, four compositions of Cr3C2-(Ni-20Cr) alloy coating powder were deposited by high-velocity oxy-fuel spray technique on T-91 boiler tube steel. The cyclic studies were performed in a coal-fired boiler at 1123 K ± 10 K (850 °C ± 10 °C). X-ray diffraction, scanning electron microscopy/energy dispersive X-ray analysis and elemental mapping analysis techniques were used to analyze the corrosion products. All the coatings deposited on T-91 boiler tube steel imparted hot corrosion resistance. The 65 pctCr3C2 -35 pct (Ni-20Cr)-coated T-91 steel sample performed better than all other coated samples in the given environment.

  16. Temperature dependence of optical properties in Nd/Cr:YAG materials

    International Nuclear Information System (INIS)

    Honda, Yoshiyuki; Motokoshi, Shinji; Jitsuno, Takahisa; Miyanaga, Noriaki; Fujioka, Kana; Nakatsuka, Masahiro; Yoshida, Minoru

    2014-01-01

    The energy transfer from Cr 3+ to Nd 3+ for Nd/Cr:YAG (Nd: 1.0%, Cr: 2.0%) materials was investigated by measuring the temperature dependences of fluorescence characteristics. The fluorescence intensity of Nd 3+ increased with temperature owing to enhancement of the absorption coefficient of Cr 3+ . The energy transfer efficiency was constant from 77 to 450 K. The energy transfer time decreased with increasing temperature. -- Highlights: • We investigate the energy transfer from Cr 3+ to Nd 3+ in Nd/Cr:YAG materials by measuring the temperature dependence of fluorescence characteristics. • The fluorescence intensity of Nd 3+ increased with temperature owing to enhancement of the absorption coefficient of Cr 3+ . • The energy transfer efficiency was constant from 77 to 450 K. • The energy transfer time decreased with increasing temperature. • Nd/Cr:YAG ceramics pumped by a flash lamp would not only provide high conversion efficiency, but can also be expected to function as an effective laser operating at high temperature

  17. Prediction of half-metallic properties in TlCrS{sub 2} and TlCrSe{sub 2} based on density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Hashimzade, F.M.; Huseinova, D.A. [Institute of Physics, National Academy of Sciences of Azerbaijan, AZ 1143 Baku (Azerbaijan); Jahangirli, Z.A. [Institute of Physics, National Academy of Sciences of Azerbaijan, AZ 1143 Baku (Azerbaijan); Institute of Radiation Problems, National Academy of Sciences of Azerbaijan, AZ 1143 Baku (Azerbaijan); Mehdiyev, B.H., E-mail: bachschi@yahoo.de [Institute of Physics, National Academy of Sciences of Azerbaijan, AZ 1143 Baku (Azerbaijan)

    2017-08-01

    Highlights: • Half-metallic properties of TlCrS2, TlCrSe2 and hypothetical TlCrSSe have been investigated by first-principles all-electron full-potential linearized augmented plane wave plus local orbital (FP-LAPW+lo) method based on density functional theory (DFT). • Total magnetic moment keeps its integer value on a relatively wide range of changes in volume (−10% ÷ 10%) for TlCrS2 and TlCrSSe, while total magnetic moment TlCrSe2 decreases with increasing volume, approaching to integer value 3 μB. • The states at the Fermi level in the case of spin-up channel consist of a hybridization of p-states of the atom S(Se) with d-states of Cr. - Abstract: Half-metallic properties of TlCrS{sub 2}, TlCrSe{sub 2} and hypothetical TlCrSSe have been investigated by first-principles all-electron full-potential linearized augmented plane wave plus local orbital (FP-LAPW+lo) method based on density functional theory (DFT). The results of calculations show that TlCrS{sub 2} and TlCrSSe are half-metals with energy gap (E{sub g}) ∼0.12 eV for spin-down channel. Strong hybridization of p-state of chalchogen and d-state of Cr leads to bonding and antibonding states and subsequently to the appearance of a gap in spin-down channel of TlCrS{sub 2} and TlCrSSe. In the case of TlCrSe{sub 2}, there is a partial hybridization and p-state is partially present in the DOS at Fermi level making this compound nearly half-metallic. The present calculations revealed that total magnetic moment keeps its integer value on a relatively wide range of changes in volume (−10% ÷ 10%) for TlCrS{sub 2} and TlCrSSe, while total magnetic moment of TlCrSe{sub 2} decreases with increasing volume approaching to integer value 3 μB.

  18. Porous CrN thin films by selectively etching CrCuN for symmetric supercapacitors

    KAUST Repository

    Wei, Binbin

    2018-03-18

    Transition metal nitrides are regarded as a new class of excellent electrode materials for high-performance supercapacitors due to their superior chemical stability and excellent electrical conductivity. We synthesize successfully the porous CrN thin films for binder-free supercapacitor electrodes by reactive magnetron co-sputtering and selective chemical etching. The porous CrN thin film electrodes exhibit high-capacitance performance (31.3 mF cm−2 at 1.0 mA cm−2) and reasonable cycling stability (94% retention after 20000 cycles). Moreover, the specific capacitance is more than two-fold higher than that of the CrN thin film electrodes in previous work. In addition, a symmetric supercapacitor device with a maximum energy density of 14.4 mWh cm−3 and a maximum power density of 6.6 W cm−3 is achieved. These findings demonstrate that the porous CrN thin films will have potential applications in supercapacitors.

  19. Porous CrN thin films by selectively etching CrCuN for symmetric supercapacitors

    Science.gov (United States)

    Wei, Binbin; Mei, Gui; Liang, Hanfeng; Qi, Zhengbing; Zhang, Dongfang; Shen, Hao; Wang, Zhoucheng

    2018-05-01

    Transition metal nitrides are regarded as a new class of excellent electrode materials for high-performance supercapacitors due to their superior chemical stability and excellent electrical conductivity. We synthesize successfully the porous CrN thin films for binder-free supercapacitor electrodes by reactive magnetron co-sputtering and selective chemical etching. The porous CrN thin film electrodes exhibit high-capacitance performance (31.3 mF cm-2 at 1.0 mA cm-2) and reasonable cycling stability (94% retention after 20000 cycles). Moreover, the specific capacitance is more than two-fold higher than that of the CrN thin film electrodes in previous work. In addition, a symmetric supercapacitor device with a maximum energy density of 14.4 mWh cm-3 and a maximum power density of 6.6 W cm-3 is achieved. These findings demonstrate that the porous CrN thin films will have potential applications in supercapacitors.

  20. Structure and magnetic properties of NdFeB thin films with Cr, Mo, Nb, Ta, Ti, and V buffer layers

    International Nuclear Information System (INIS)

    Jiang, H.; O'Shea, M.J.

    2000-01-01

    Layers of NdFeB of the form A(20 nm)/NdFeB(d nm)/A(20 nm) where A represents Cr, Mo, Nb, Ta, Ti, V were prepared on a silicon substrate by magnetron sputtering. The purpose is to determine how (i) the chosen buffer layer and (ii) NdFeB layer thickness d (especially d 2 Fe 14 B with no preferred crystalline orientation. Our highest coercivities occur for buffer layer elements from row five of the periodic table, 20 kOe (1600 kA/m) in a Nb buffered sample with d of 180 nm and 17 kOe (1350 kA/m) in a Mo buffered sample with d of 180 nm. Buffer layers from row four (Ti, V, and Cr) and row six (Ta) all give lower coercivities. Our largest energy product, 10.3 MG-Oe (82 kJ/m 3 ), is obtained for the Mo buffered sample. Average Nd 2 Fe 14 B crystallite size for this sample is 27 nm. Only the Cr and Ti buffered films show a large coercivity (≥2 kOe) for d of 54 nm with the Cr films showing the highest coercivity, 2.7 kOe (215 kA/m). In films subjected to a rapid thermal anneal (anneal time 30 s) we find that both the coercivity and energy product are larger than in samples subjected to a 20 min anneal. In our Nb buffered systems we obtain coercivities as high as 26.3 kOe (2090 kA/m) after a rapid thermal anneal

  1. Study of the oxidation of Fe-Cr alloys at high temperatures; Estudo da oxidacao de ligas Fe-Cr a altas temperaturas

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, J.F.; Sabioni, A.C.S. [Universidade Federal de Ouro Preto (LDM/DF/UFOP), MG (Brazil). Dept. de Fisica. Lab. de Difusao em Materiais; Trindade, V.B. [Universidade Federal de Ouro Preto (DEMM/UFOP), MG (Brazil). Dept. de Engenharia Metalurgica e de Materiais; Ji, V. [Laboratoire d' Etude des Materiaux Hors-Equilibre (LEMHE), Orsay (France)

    2010-07-01

    The high temperature oxidation behavior of Fe-1.5%Cr, Fe-5.0%Cr, Fe-10%Cr and Fe- 15%Cr model alloys were investigated from 700 to 850 deg C, in air atmosphere. The oxidation treatments were performed in a thermobalance with a sensitivity of 1{mu}g. The oxide films grown by oxidation of the alloys were characterized by scanning electronic microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The oxide films are Fe-Cr spinels with variable composition depending on the alloy composition. For all conditions studied, the oxidation kinetics of these alloys follow a parabolic law. The comparison of the oxidation rates of the four alloys, at 700 deg C, shows that the parabolic oxidation constants decrease from 1.96x10{sup -9}g{sup 2}.cm{sup -4}.s{sup -1}, for the alloy Fe-1.5% Cr, to 1.18 x 10-14g{sup 2}.cm{sup -4}.s{sup -1} for the alloy Fe-15% Cr. Comparative analysis of the oxidation behavior of the Fe-10%Cr and Fe-15%Cr alloys, between 700 and 850 deg C, shows that the oxidation rates of these alloys are comparable to 800 deg C, above this temperature the Fe-10%Cr alloy shows lower resistance to oxidation. (author)

  2. CR-39 plastic nuclear track detector and its application in nuclear science

    International Nuclear Information System (INIS)

    Zhai Pengji; Tang Xiaowei; Wang Long; Liang Tianjiao

    2000-01-01

    The transparent and stable plastic material CR-39 can be used as a nuclear track detector which is highly sensitive to charged particles. It can record tracks induced by protons , alphas, fission fragments and other charged particles. Among various available solid state nuclear track detectors CR-39 has the lowest deposited energy density detection-threshold. The response of CR-39 to charged particles and the response curve of υ T of different charged particles to REL are given. The CR-39 detector is widely used in studies of nuclear reactions, angular distributions and reaction cross-sections caused by neutrons and charged particles. Neutron spectra, over a wide energy range, can be measured by the combination of CR-39 and a transformation screen. The successful applications of CR-39 in alpha particle dosimetry, environmental science (especially in the measurement of radon) and in biomedicine, such as the analysis of alpha radioactivity in sections of organic tissues, are described

  3. Eyebrow hairs from actinic keratosis patients harbor the highest number of cutaneous human papillomaviruses

    Science.gov (United States)

    2013-01-01

    Background Cutaneous human papillomavirus (HPV) infections seem to be associated with the onset of actinic keratosis (AK). This study compares the presence of cutaneous HPV types in eyebrow hairs to those in tissues of normal skin and skin lesions of 75 immunocompetent AK patients. Methods Biopsies from AK lesions, normal skin and plucked eyebrow hairs were collected from each patient. DNA from these specimens was tested for the presence of 28 cutaneous HPV (betaPV and gammaPV) by a PCR based method. Results The highest number of HPV prevalence was detected in 84% of the eyebrow hairs (63/75, median 6 types) compared to 47% of AK lesions (35/75, median 3 types) (p< 0.001) and 37% of normal skin (28/75, median 4 types) (p< 0.001), respectively. A total of 228 HPV infections were found in eyebrow hairs compared to only 92 HPV infections in AK and 69 in normal skin. In all three specimens HPV20, HPV23 and/or HPV37 were the most prevalent types. The highest number of multiple types of HPV positive specimens was found in 76% of the eyebrow hairs compared to 60% in AK and 57% in normal skin. The concordance of at least one HPV type in virus positive specimens was 81% (three specimens) and 88-93% of all three combinations with two specimens. Conclusions Thus, eyebrow hairs revealed the highest number of cutaneous HPV infections, are easy to collect and are an appropriate screening tool in order to identify a possible association of HPV and AK. PMID:23618013

  4. Remediation of Cr(VI) contaminated soil using long-duration sodium thiosulfate supported by micro–nano networks

    International Nuclear Information System (INIS)

    He, Lulu; Wang, Min; Zhang, Guilong; Qiu, Guannan; Cai, Dongqing; Wu, Zhengyan; Zhang, Xin

    2015-01-01

    Highlights: • This work aims to develop a long-duration remediation agent (LRA). • LRA was obtained using Na 2 S 2 O 3 supported by attapulgite (ATP) micro–nano networks. • ATP micro–nano networks was induced by high-energy electron beam irradiation. • LRA can effectively control the migration of Cr(VI) and reducing Cr(VI) to Cr(III). • LRA displayed high performance on the remediation of heavy metal contaminated soil. - Abstract: In this work, a long-duration remediation agent (LRA) on hexavalent chromium (Cr(VI)) was developed using sodium thiosulfate (ST) supported by attapulgite (ATP) micro–nano networks induced through high-energy electron beam (HEEB) irradiation. The ATP networks could effectively reduce the leaching amount of Cr(VI) in soil. More importantly, the ATP networks could significantly control the leaching behavior of ST, and then prolong the duration and increase the reduction efficiency of ST on Cr(VI). As a result, LRA displayed high performance on controlling the migration of Cr(VI) and reducing Cr(VI) to Cr(III). Additionally, pot experiment indicated that LRA could effectively decrease the absorbed amount of Cr(VI) in corn, and reduce the inhibition effect of Cr(VI) on the growth of corn. Therefore, this work could provide a facile approach to remediate the Cr(VI)-contaminated soil and lower the harmful effect of Cr(VI) on crop

  5. Remediation of Cr(VI) contaminated soil using long-duration sodium thiosulfate supported by micro–nano networks

    Energy Technology Data Exchange (ETDEWEB)

    He, Lulu [School of Life Sciences, Anhui Agricultural University, Hefei 230036 (China); Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); Wang, Min; Zhang, Guilong [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); Bioenergy Forest Research Center of State Forestry Administration, Hefei 230031 (China); Qiu, Guannan [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); Cai, Dongqing, E-mail: dqcai@ipp.ac.cn [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); Bioenergy Forest Research Center of State Forestry Administration, Hefei 230031 (China); Wu, Zhengyan, E-mail: zywu@ipp.ac.cn [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui 230031 (China); Bioenergy Forest Research Center of State Forestry Administration, Hefei 230031 (China); Zhang, Xin, E-mail: xinzhang@ahau.edu.cn [School of Life Sciences, Anhui Agricultural University, Hefei 230036 (China)

    2015-08-30

    Highlights: • This work aims to develop a long-duration remediation agent (LRA). • LRA was obtained using Na{sub 2}S{sub 2}O{sub 3} supported by attapulgite (ATP) micro–nano networks. • ATP micro–nano networks was induced by high-energy electron beam irradiation. • LRA can effectively control the migration of Cr(VI) and reducing Cr(VI) to Cr(III). • LRA displayed high performance on the remediation of heavy metal contaminated soil. - Abstract: In this work, a long-duration remediation agent (LRA) on hexavalent chromium (Cr(VI)) was developed using sodium thiosulfate (ST) supported by attapulgite (ATP) micro–nano networks induced through high-energy electron beam (HEEB) irradiation. The ATP networks could effectively reduce the leaching amount of Cr(VI) in soil. More importantly, the ATP networks could significantly control the leaching behavior of ST, and then prolong the duration and increase the reduction efficiency of ST on Cr(VI). As a result, LRA displayed high performance on controlling the migration of Cr(VI) and reducing Cr(VI) to Cr(III). Additionally, pot experiment indicated that LRA could effectively decrease the absorbed amount of Cr(VI) in corn, and reduce the inhibition effect of Cr(VI) on the growth of corn. Therefore, this work could provide a facile approach to remediate the Cr(VI)-contaminated soil and lower the harmful effect of Cr(VI) on crop.

  6. 17-Year-Old Boy with Renal Failure and the Highest Reported Creatinine in Pediatric Literature

    Directory of Open Access Journals (Sweden)

    Vimal Master Sankar Raj

    2015-01-01

    Full Text Available The prevalence of chronic kidney disease (CKD is on the rise and constitutes a major health burden across the world. Clinical presentations in early CKD are usually subtle. Awareness of the risk factors for CKD is important for early diagnosis and treatment to slow the progression of disease. We present a case report of a 17-year-old African American male who presented in a life threatening hypertensive emergency with renal failure and the highest reported serum creatinine in a pediatric patient. A brief discussion on CKD criteria, complications, and potential red flags for screening strategies is provided.

  7. Addressing the Highest Risk: Environmental Programs at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, Elaine E [Los Alamos National Laboratory

    2012-06-08

    Report topics: Current status of cleanup; Shift in priorities to address highest risk; Removal of above-ground waste; and Continued focus on protecting water resources. Partnership between the National Nuclear Security Administration's Los Alamos Site Office, DOE Carlsbad Field Office, New Mexico Environment Department, and contractor staff has enabled unprecedented cleanup progress. Progress on TRU campaign is well ahead of plan. To date, have completed 130 shipments vs. 104 planned; shipped 483 cubic meters of above-ground waste (vs. 277 planned); and removed 11,249 PE Ci of material at risk (vs. 9,411 planned).

  8. Study of the Effects of High Temperatures on the Engineering Properties of Steel 42CrMo4

    Science.gov (United States)

    Brnic, Josip; Turkalj, Goran; Canadija, Marko; Lanc, Domagoj; Brcic, Marino

    2015-02-01

    The paper presents and analyzes the experimental results of the effect of elevated temperatures on the engineering properties of steel 42CrMo4. Experimental data relating to the mechanical properties of the material, the creep resistance as well as Charpy impact energy. Temperature dependence of the mentioned properties is also shown. Some of creep curves were simulated using rheological models and an analytical equation. Finally, an assessment of fracture toughness was made that was based on experimentally determined Charpy impact energy. Based on the obtained results it is visible that the tensile strength (617 MPa) and yield strength (415 MPa) have the highest value at the room temperature while at the temperature of 700 °C (973 K) these values significantly decrease. This steel can be considered resistant to creep at 400 °C (673 K), but at higher temperatures this steel can be subjected to low levels of stress in a shorter time.

  9. Complex analysis and CR geometry

    CERN Document Server

    Zampieri, Giuseppe

    2008-01-01

    Cauchy-Riemann (CR) geometry is the study of manifolds equipped with a system of CR-type equations. Compared to the early days when the purpose of CR geometry was to supply tools for the analysis of the existence and regularity of solutions to the \\bar\\partial-Neumann problem, it has rapidly acquired a life of its own and has became an important topic in differential geometry and the study of non-linear partial differential equations. A full understanding of modern CR geometry requires knowledge of various topics such as real/complex differential and symplectic geometry, foliation theory, the geometric theory of PDE's, and microlocal analysis. Nowadays, the subject of CR geometry is very rich in results, and the amount of material required to reach competence is daunting to graduate students who wish to learn it. However, the present book does not aim at introducing all the topics of current interest in CR geometry. Instead, an attempt is made to be friendly to the novice by moving, in a fairly relaxed way, f...

  10. Automatic orbital GTAW welding: Highest quality welds for tomorrow's high-performance systems

    Science.gov (United States)

    Henon, B. K.

    1985-01-01

    Automatic orbital gas tungsten arc welding (GTAW) or TIG welding is certain to play an increasingly prominent role in tomorrow's technology. The welds are of the highest quality and the repeatability of automatic weldings is vastly superior to that of manual welding. Since less heat is applied to the weld during automatic welding than manual welding, there is less change in the metallurgical properties of the parent material. The possibility of accurate control and the cleanliness of the automatic GTAW welding process make it highly suitable to the welding of the more exotic and expensive materials which are now widely used in the aerospace and hydrospace industries. Titanium, stainless steel, Inconel, and Incoloy, as well as, aluminum can all be welded to the highest quality specifications automatically. Automatic orbital GTAW equipment is available for the fusion butt welding of tube-to-tube, as well as, tube to autobuttweld fittings. The same equipment can also be used for the fusion butt welding of up to 6 inch pipe with a wall thickness of up to 0.154 inches.

  11. Optimasi Penggunaan Lahan Kosong di Kecamatan Baturiti Untuk Properti Komersial Dengan Prinsip Highest and Best Use

    Directory of Open Access Journals (Sweden)

    Made Darmawan Saputra Mahardika

    2013-09-01

    Full Text Available Kecamatan Baturiti merupakan satu-satunya kecamatan di Kabupaten Tabanan yang berkembang dalam sektor ekonomi agrowisata karena lokasinya yang strategis dekat dengan berbagai obyek wisata terkenal. Dengan lokasi yang strategis, pembangunan untuk properti komersial tentu akan memberikan potensi keuntungan tinggi bagi investor yang memiliki lahan kosong di Kecamatan Baturiti. Kondisi seperti ini menyebabkan permintaan yang tinggi akan lahan, padahal ketersediaan lahan selalu berkurang. Pembangunan properti komersial di Kecamatan Baturiti perlu dioptimalisasi agar dicapai keuntungan maksimum bagi investor. Berdasarkan hal tersebut, investor yang ingin membangun di Kecamatan Baturiti memerlukan analisa untuk mendapatkan alternatif pemanfaatan lahan kosong. Lahan yang dianalisa merupakan lahan kosong belum terbangun seluas 22.175 m2 di Kecamatan Baturiti, Kabupaten Tabanan. Metode yang digunakan untuk mengetahui alternatif pendirian bangunan komersial yang memiliki nilai pasar tertinggi adalah Highest and Best Use (HBU. Dengan metode tersebut, pemilik lahan dapat mengetahui alternatif terbaik yang memenuhi syarat-syarat diijinkan secara legal, memungkinkan secara fisik, layak secara finansial, dan memiliki produktivitas maksimum. Hasil yang diperoleh dari analisa Highest and Best Use ini adalah alternatif mixed-use berupa hotel dan toko souvenir dengan nilai lahan tertinggi dibandingkan alternatif lainnya sebesar Rp 7,950,714.60 per m2.

  12. A novel method to predict the highest hardness of plasma sprayed coating without micro-defects

    Science.gov (United States)

    Zhuo, Yukun; Ye, Fuxing; Wang, Feng

    2018-04-01

    The plasma sprayed coatings are stacked by splats, which are regarded generally as the elementary units of coating. Many researchers have focused on the morphology and formation mechanism of splat. However, a novel method to predict the highest hardness of plasma sprayed coating without micro-defects is proposed according to the nanohardness of splat in this paper. The effectiveness of this novel method was examined by experiments. Firstly, the microstructure of splats and coating, meanwhile the 3D topography of the splats were observed by SEM (SU1510) and video microscope (VHX-2000). Secondly, the nanohardness of splats was evaluated by nanoindentation (NHT) in order to be compared with microhardness of coating measured by microhardness tester (HV-1000A). The results show that the nanohardness of splats with diameter of 70 μm, 100 μm and 140 μm were in the scope of 11∼12 GPa while the microhardness of coating were in the range of 8∼9 GPa. Because the splats had not micro-defects such as pores and cracks in the nanohardness evaluated nano-zone, the nanohardness of the splats can be utilized to predict the highest hardness of coating without micro-defects. This method indicates the maximum of sprayed coating hardness and will reduce the test number to get high hardness coating for better wear resistance.

  13. The electronic structure of the metastable layer compound 1T-CrSe2

    NARCIS (Netherlands)

    Fang, C.M.; Groot, R.A. de; Wiegers, G.A.; Haas, C.; vanBruggen, C.F.; deGroot, R.A.

    1997-01-01

    The electronic structure of the metastable compound 1T-CrSe2 (a = 3.399 Å, c = 5.911 Å, space group P_3m1) was calculated with and without spin polarization using the LSW method. The energy is 0.29 eV/mol CrSe2 lower for the spin-polarized calculation. The total magnetic moment of +2.44 μB on Cr

  14. Preparation and Oxidation Performance of Y and Ce-Modified Cr Coating on open-cell Ni-Cr-Fe Alloy Foam by the Pack Cementation

    Science.gov (United States)

    Pang, Q.; Hu, Z. L.; Wu, G. H.

    2016-12-01

    Metallic foams with a high fraction of porosity, low density and high-energy absorption capacity are a rapidly emerging class of novel ultralight weight materials for various engineering applications. In this study, Y-Cr and Ce-Cr-coated Ni-Cr-Fe alloy foams were prepared via the pack cementation method, and the effects of Y and Ce addition on the coating microstructure and oxidation performance were analyzed in order to improve the oxidation resistance of open-cell nickel-based alloy foams. The results show that the Ce-Cr coating is relatively more uniform and has a denser distribution on the surface of the nickel-based alloy foam. The surface grains of the Ce-Cr-coated alloy foam are finer compared to those of the Y-Cr-coated alloy foam. An obvious Ce peak appears on the interface between the coating and the alloy foam strut, which gives rise to a "site-blocking" effect for the short-circuit transport of the cation in the substrate. X-ray diffraction analysis shows that the Y-Cr-coated alloy foam mainly consists of Cr, (Fe, Ni) and (Ni, Cr) phases in the surface layer. The Ce-Cr-coated alloy foam is mainly composed of Cr and (Ni, Cr) phases. Furthermore, the addition of Y and Ce clearly lead to an improvement in the oxidation resistance of the coated alloy foams in the temperature range of 900-1000 °C. The addition of Ce is especially effective in enhancing the diffusion of chromium to the oxidation front, thus, accelerating the formation of a Cr2O3 layer.

  15. Development of Cr3C2-25(Ni20Cr) nanostructured coatings

    International Nuclear Information System (INIS)

    Cunha, Cecilio Alvares da

    2012-01-01

    This study is divided in two parts. The first part is about the preparation of nanostructured Cr 3 C 2 -25(Ni20Cr) powders by high energy milling followed by characterization of the milled and the as received powder. Analyses of some of the data obtained were done using a theoretical approach. The second part of this study is about the preparation and characterization of coatings prepared with the nanostructured as well as the as received Cr 3 C 2 -25(Ni20Cr) powders. The high temperature erosion-oxidation (E-O) behavior of the coatings prepared with the two types of powders has been compared based on a technological approach. The average crystallite size of the Cr 3 C 2 -25(Ni20Cr) powder decreased rapidly from 145 nm to 50 nm in the initial stages of milling and thereafter decreased slowly to a steady state value of around 10 nm with further increase in milling time. This steady state corresponds to the beginning of a dynamic recovery process. The maximum lattice strain (ε = 1,17%) was observed in powders milled for 16 hours, and this powders critical crystallite size was 28 nm. In contrast, the lattice parameter attained a minimum for powders milled for 16 hours. Upon reaching the critical crystallite size, the dislocation density attained a steady state regime and all plastic deformation introduced in the material there after was in the form of events occurring at the grain boundaries, due mainly to grain boundary sliding. The deformation energy stored in the crystal lattice of the Cr 3 C 2 -25(Ni20Cr) powders milled for different times was determined from enthalpy variation measurements. These results indicated that the maximum enthalpy variation (δH = 722 mcal) also occurred for powders milled for 16 hours. In a similar manner, the maximum specific heat variation (δC p = 0,278 cal/gK) occurred for powders milled for 16 hours. The following mechanical properties of Cr 3 C 2 -25(Ni20Cr) coatings prepared using the HVOF thermal spray process were determined

  16. Ab-initio study of the structural, magnetic and electric properties of NixCr1-x x={0.125, 0.25, 0.375, 0.5, 0.625, 0.75, 0.875}

    Directory of Open Access Journals (Sweden)

    R. Golsorkhtabar

    2007-03-01

    Full Text Available  We investigated the structural, magnetic and electronic properties of NixCr1-x alloy in the range 0.125≤ x ≤0.875 by using FP-LAPW method to solve Kohn-Sham equations. In structural study, we calculated the formation energy, lattice parameter and bulk modulus for bcc and fcc structures within ferromagnetic, ferromagnetic and paramagnetic phases. Our results indicate that the system preference for alloy formation is higher in the range of x=0.625 – 0.75 compared to other studied concentrations. Moreover, by investigation of the values obtained for the lattice parameter and bulk modulus we found out that Cr-Ni bond is weaker than Ni-Ni and Cr-Cr bonds. Additionally, our magnetic results indicate that the magnetic interactions among atoms in bcc structures have probably RKKY behavior. Finally, our results show that the Ni0.75Cr0.25 alloy with fcc structure ans spin polarization of 90% has the highest magnetic and structural stability.

  17. Energy

    CERN Document Server

    Robertson, William C

    2002-01-01

    Confounded by kinetic energy? Suspect that teaching about simple machines isn t really so simple? Exasperated by electricity? If you fear the study of energy is beyond you, this entertaining book will do more than introduce you to the topic. It will help you actually understand it. At the book s heart are easy-to-grasp explanations of energy basics work, kinetic energy, potential energy, and the transformation of energy and energy as it relates to simple machines, heat energy, temperature, and heat transfer. Irreverent author Bill Robertson suggests activities that bring the basic concepts of energy to life with common household objects. Each chapter ends with a summary and an applications section that uses practical examples such as roller coasters and home heating systems to explain energy transformations and convection cells. The final chapter brings together key concepts in an easy-to-grasp explanation of how electricity is generated. Energy is the second book in the Stop Faking It! series published by NS...

  18. Thermochemistry of α-D-xylose(cr)

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Ribeiro da Silva, Maria D.M.C.; Lobo Ferreira, Ana I.M.C.; Shi, Quan; Woodfield, Brian F.; Goldberg, Robert N.

    2013-01-01

    Highlights: ► Well-characterized material. ► Oxygen bomb calorimetry. ► Heat capacities obtained by using a Physical Property Measurement System. ► Thermochemical Network Calculations. ► Accurate thermodynamic property values of a key biochemical substance. -- Abstract: The thermochemistry of α-D-xylose(cr) was studied by means of oxygen bomb calorimetry and a Physical Property Measurement System (PPMS) in zero magnetic field. The sample of α-D-xylose(cr) used in this study was one well-characterized by HPLC, Karl Fischer analysis, NMR, and by carbon dioxide analysis. The standard molar enthalpy of combustion was found to be Δ c H m o = −(2342.2 ± 0.8) kJ·mol −1 at T = 298.15 K and at the standard pressure p° = 0.1 MPa. The standard molar heat capacity for α-D-xylose(cr) was measured with the PPMS over the temperature range 1.9001 ⩽ T/K ⩽ 303.66. At T = 298.15 K, C p,m o = (178.1 ± 1.8) J·K −1 ·mol −1 . The values of C p,m o were fit as a function of T by using theoretical and empirical models for appropriate temperature ranges. The results of these fits were used to calculate values of C p,m o , the entropy increment Δ 0 T S m o , Δ 0 T H m o , and Φ m o =(Δ 0 T S m o -Δ 0 T H m o /T) from T = 0.5 K to T = 300 K. Derived quantities for α-D-xylose(cr) are the standard molar enthalpy of formation Δ f H m o = −(1054.5 ± 1.1) kJ·mol −1 , the third law standard molar entropy S m o = (175.3 ± 1.9) J·K −1 ·mol −1 , and the standard molar Gibbs energy of formation Δ f G m o = −(750.5 ± 1.0) kJ·mol −1 . A comparison of values of Δ c H m o and S m o for the five-carbon aldoses demonstrated a striking similarity in the values of these respective properties for α-D-xylose(cr), D-ribose(cr), and D-arabinose(cr). Thermochemical network calculations were performed that led to values of the standard formation properties at T = 298.15 K for a variety of biochemical substances: D-xylose(aq), D-xylose − (aq), D-xylose 2

  19. AEC testing in a CR environment

    International Nuclear Information System (INIS)

    McLeod, R.

    2004-01-01

    Full text: Testing of x-ray machine automatic exposure control (AEC) functionality for varying kVp and patient thickness is a fundamental health physics check. Current test protocols tend to be based on testing in a film environment using film optical density as the measure of conformance. With the move into the digital x-ray image age with the use of computed radiography (CR) and digital radiography (DR) equipment and its associated image storage and retrieval system (PACS) a new AEC testing protocol is required. All CR systems provide a dose assessment tool (called Exposure Index or EI by Kodak) that could be used as a surrogate for optical density. However this work aims to derive an efficient means of assessing the functioning of the AEC of x-ray machines in a CR environment using dose measurement alone. This would eliminate the need to process the many image plates normally required for AEC testing in order to obtain and analyse the exposure measure from the CR system. The EI, and other brand's equivalents, is calibrated for a given condition (for Kodak 80kVp 0.5mmCu + 1mmAl). In order to use dose measurement alone the relationship between EI and dose must be known for varying kVp and patient thicknesses (represented by a perspex phantom). This will depend on the response of the CR plate to varying beam energies. This was assessed using a series of paired exposures at various kVp and perspex thicknesses. In the first exposure of each pair a Kodak CR plate was used, processed in the normal way, and the EI noted. In a second identical exposure an Innovision 35050A pancake ionization chamber was placed in the bucky tray within a specially modified film cassette and the dose measured. Over the 50-125kVp range of clinical use the kV response of the Kodak PSP's shown below is essentially flat for a set dose to the image plate and filtered using the standard Kodak method of 0.5mmCu + 1mmAl. Similar data will be presented showing this relationship using a perspex

  20. Excitation functions of the {sup nat}Cr(p,x){sup 44}Ti, {sup 56}Fe(p,x){sup 44}Ti, {sup nat}Ni(p,x){sup 44}Ti and {sup 93}Nb(p,x){sup 44}Ti reactions at energies up to 2.6 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Titarenko, Yu. E.; Batyaev, V.F.; Pavlov, K.V.; Titarenko, A. Yu. [National Research Center Kurchatov Institute, Institute for Theoretical and Experimental Physics, Moscow 117218 (Russian Federation); Zhivun, V.M. [National Research Center Kurchatov Institute, Institute for Theoretical and Experimental Physics, Moscow 117218 (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow 115409 (Russian Federation); Chauzova, M.V.; Balyuk, S.A.; Bebenin, P.V. [National Research Center Kurchatov Institute, Institute for Theoretical and Experimental Physics, Moscow 117218 (Russian Federation); Ignatyuk, A.V. [National Research Center Kurchatov Institute, Institute for Theoretical and Experimental Physics, Moscow 117218 (Russian Federation); Institute of Physics and Power Engineering, Obninsk 249033 (Russian Federation); Mashnik, S.G. [Los Alamos National Laboratory (United States); Leray, S.; Boudard, A.; David, J.C.; Mancusi, D. [CEA/Saclay, Irfu/SPhN, 91191 Gif-sur-Yvette, Cedex (France); Cugnon, J. [University of Liege (Belgium); Yariv, Y. [SoreqNRC, Yavne (Israel); Nishihara, K.; Matsuda, N. [JAEA, Tokai (Japan); Kumawat, H. [BARC, Mumbai (India); Stankovskiy, A. Yu. [SCK-CEN (Belgium)

    2016-06-11

    The paper presents the measured cumulative yields of {sup 44}Ti for {sup nat}Cr, {sup 56}Fe, {sup nat}Ni and {sup 93}Nb samples irradiated by protons at the energy range 0.04–2.6 GeV. The obtained excitation functions are compared with calculations of the well-known codes: ISABEL, Bertini, INCL4.2+ABLA, INCL4.5+ABLA07, PHITS, CASCADE07 and CEM03.02. The predictive power of these codes regarding the studied nuclides is analyzed.

  1. Analisa Highest and Best Use Pada Lahan Kosong Di Jemur Gayungan II Surabaya

    Directory of Open Access Journals (Sweden)

    Finda Virgitta Faradiany

    2014-09-01

    Full Text Available Perkembangan bisnis properti di Surabaya yang semakin pesat, mengakibatkan permintaan terhadap lahan semakin tinggi. Namun fakta di lapangan menampakkan hal yang sebaliknya karena ternyata masih terdapat lahan-lahan yang dibiarkan kosong tidak dimanfaatkan oleh pemiliknya. Kondisi yang demikian memerlukan efisiensi dan optimalisasi penggunaan lahan dengan mendirikan sebuah properti komersial yang memberikan keuntungan bagi pemilik serta lingkungan sekitarnya.Lahan “X” seluas 1786 m2 berlokasi di Jl. Jemur Gayungan II merupakan lahan kosong yang terletak di dekat daerah perkantoran dan berpotensi dikembangkan menjadi properti komersial. Penentuan nilai lahan “X” bergantung pada penggunaan lahan. Metode penilaian yang digunakan adalah analisa penggunaan tertinggi dan terbaik atau Highest and Best Use (HBU yang secara legal diijinkan, secara fisik memungkinkan, layak secara finansial dan memiliki produktifitas maksimum. Dari hasil penelitian didapatkan alternatif yang menghasilkan nilai lahan tertinggi dan produktivitas maksimum adalah hotel. Nilai lahan yang didapatkan sebesar Rp 9.722.718/m2 dengan produktivitas meningkat sebesar 486%.

  2. Failure of ETV in patients with the highest ETV success scores.

    Science.gov (United States)

    Gianaris, Thomas J; Nazar, Ryan; Middlebrook, Emily; Gonda, David D; Jea, Andrew; Fulkerson, Daniel H

    2017-09-01

    OBJECTIVE Endoscopic third ventriculostomy (ETV) is a surgical alternative to placing a CSF shunt in certain patients with hydrocephalus. The ETV Success Score (ETVSS) is a reliable, simple method to estimate the success of the procedure by 6 months of postoperative follow-up. The highest score is 90, estimating a 90% chance of the ETV effectively treating hydrocephalus without requiring a shunt. Treatment with ETV fails in certain patients, despite their being the theoretically best candidates for the procedure. In this study the authors attempted to identify factors that further predicted success in patients with the highest ETVSSs. METHODS A retrospective review was performed of all patients treated with ETV at 3 institutions. Demographic, radiological, and clinical data were recorded. All patients by definition were older than 1 year, had obstructive hydrocephalus, and did not have a prior shunt. Failure of ETV was defined as the need for a shunt by 1 year. The ETV was considered a success if the patient did not require another surgery (either shunt placement or a repeat endoscopic procedure) by 1 year. A statistical analysis was performed to identify factors associated with success or failure. RESULTS Fifty-nine patients met the entry criteria for the study. Eleven patients (18.6%) required further surgery by 1 year. All of these patients received a shunt. The presenting symptom of lethargy statistically correlated with success (p = 0.0126, odds ratio [OR] = 0.072). The preoperative radiological finding of transependymal flow (p = 0.0375, OR 0.158) correlated with success. A postoperative larger maximum width of the third ventricle correlated with failure (p = 0.0265). CONCLUSIONS The preoperative findings of lethargy and transependymal flow statistically correlated with success. This suggests that the best candidates for ETV are those with a relatively acute elevation of intracranial pressure. Cases without these findings may represent the failures in this

  3. The highest velocity and the shortest duration permitting attainment of VO2max during running

    Directory of Open Access Journals (Sweden)

    Tiago Turnes

    2015-02-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n2p226   The severe-intensity domain has important applications for the prescription of running training and the elaboration of experimental designs. The objectives of this study were: 1 to investigate the validity of a previously proposed model to estimate the shortest exercise duration (TLOW and the highest velocity (VHIGH at which VO2max is reached during running, and 2 to evaluate the effects of aerobic training status on these variables. Eight runners and eight physically active subjects performed several treadmill running exercise tests to fatigue in order to mathematically estimate and to experimentally determine TLOW and VHIGH. The relationship between the time to achieve VO2max and time to exhaustion (Tlim was used to estimate TLOW. VHIGH was estimated using the critical velocity model. VHIGH was assumed to be the highest velocity at which VO2 was equal to or higher than the average VO2max minus one standard deviation. TLOW was defined as Tlim associated with VHIGH. Runners presented better aerobic fitness and higher VHIGH (22.2 ± 1.9 km.h-1 than active subjects (20.0 ± 2.1 km.h-1. However, TLOW did not differ between groups (runners: 101 ± 39 s; active subjects: 100 ± 35 s. TLOW and VHIGH were not well estimated by the model proposed, with high coefficients of variation (> 6% and a low correlation coefficient (r<0.70, a fact reducing the validity of the model. It was concluded that aerobic training status positively affected only VHIGH. Furthermore, the model proposed presented low validity to estimate the upper boundary of the severe-intensity domain (i.e., VHIGH, irrespective of the subjects’ training status.

  4. Proton an alpha detections by track recording technique in CR-39

    International Nuclear Information System (INIS)

    Oliveira, W.A. de; Franco, M.A.R.; Herdade, S.B.; Khouri, M.C.F.; Goncalez, O.L.

    1986-07-01

    The plastic CR-39 is utilized as proton track detector in the study of the reaction 27 A (e, p) and 59 Co (e, p), near threshold. Preliminary results are presented for the energy calibration (mean track diameter as a function of proton energy) of CR-39 with mono-energetic protons of a Van de Graaff accelerator, in the energy range 1-3 MeV. (author) [pt

  5. Cr(III) reactivity and foot dermatitis in Cr(VI) positive patients

    DEFF Research Database (Denmark)

    Hansen, Malene Barré; Menné, Torkil; Johansen, Jeanne Duus

    2006-01-01

    Chromium allergy has become synonymous with Cr(VI) allergy. However, real exposure to chromium from leather products may include both Cr(III) and Cr(VI). In this study, we investigate the reactivity to both Cr(VI) and Cr(III) in consecutive patients to analyse the relation between foot eczema/leather...... to Cr(III). The increased risk was not due to a higher degree of sensitivity to Cr(VI). Leather was reported most frequently as the suspected cause of chromium dermatitis (54%). However, Cr(VI) allergics having foot eczema and positive or doubtful Cr(III) reactions often had positive reactions to other...

  6. Energy

    International Nuclear Information System (INIS)

    1975-10-01

    On the occasion of the World Environment Day the Norwegian Ministry for the Environment held a conference on growth problems in energy consumption. The themes which were treated were energy conservation, hydroelectric power, the role of nuclear power, radioactive waste disposal, fossil fuel resources, ecological limits, pollution and international aspects. Nuclear energy forms the main theme of one lecture and an aspect of several others. (JIW)

  7. Energy

    OpenAIRE

    Torriti, Jacopo

    2016-01-01

    The impact of energy policy measures has been assessed with various appraisal and evaluation tools since the 1960s. Decision analysis, environmental impact assessment and strategic environmental assessment are all notable examples of progenitors of Regulatory Impact Assessment (RIA) in the assessment of energy policies, programmes and projects. This chapter provides overview of policy tools which have been historically applied to assess the impacts of energy policies, programmes and projects....

  8. CR-39 track detector for multi-MeV ion spectroscopy.

    Science.gov (United States)

    Jeong, T W; Singh, P K; Scullion, C; Ahmed, H; Hadjisolomou, P; Jeon, C; Yun, H; Kakolee, K F; Borghesi, M; Ter-Avetisyan, S

    2017-05-19

    We present the characteristics of track formation on the front and rear surfaces of CR-39 produced by laser-driven protons and carbon ions. A methodological approach, based on bulk etch length, is proposed to uniquely characterize the particle tracks in CR-39, enabling comparative description of the track characteristics in different experiments. The response of CR-39 to ions is studied based on the energy dependent growth rate of the track diameter to understand the intrinsic particle stopping process within the material. A large non-uniformity in the track diameter is observed for CR-39 with thickness matching with the stopping range of particles. Simulation and experimental results show the imprint of longitudinal range straggling for energetic protons. Moreover, by exploiting the energy dependence of the track diameter, the energy resolution (δE/E) of CR-39 for few MeV protons and Carbon ion is found to be about 3%.

  9. Energies

    International Nuclear Information System (INIS)

    2003-01-01

    In the framework of the National Debate on the energies in a context of a sustainable development some associations for the environment organized a debate on the nuclear interest facing the renewable energies. The first part presents the nuclear energy as a possible solution to fight against the greenhouse effect and the associated problem of the wastes management. The second part gives information on the solar energy and the possibilities of heat and electric power production. A presentation of the FEE (French wind power association) on the situation and the development of the wind power in France, is also provided. (A.L.B.)

  10. Site characterization of the highest-priority geologic formations for CO2 storage in Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Surdam, Ronald C. [Univ. of Wyoming, Laramie, WY (United States); Bentley, Ramsey [Univ. of Wyoming, Laramie, WY (United States); Campbell-Stone, Erin [Univ. of Wyoming, Laramie, WY (United States); Dahl, Shanna [Univ. of Wyoming, Laramie, WY (United States); Deiss, Allory [Univ. of Wyoming, Laramie, WY (United States); Ganshin, Yuri [Univ. of Wyoming, Laramie, WY (United States); Jiao, Zunsheng [Univ. of Wyoming, Laramie, WY (United States); Kaszuba, John [Univ. of Wyoming, Laramie, WY (United States); Mallick, Subhashis [Univ. of Wyoming, Laramie, WY (United States); McLaughlin, Fred [Univ. of Wyoming, Laramie, WY (United States); Myers, James [Univ. of Wyoming, Laramie, WY (United States); Quillinan, Scott [Univ. of Wyoming, Laramie, WY (United States)

    2013-12-07

    This study, funded by U.S. Department of Energy National Energy Technology Laboratory award DE-FE0002142 along with the state of Wyoming, uses outcrop and core observations, a diverse electric log suite, a VSP survey, in-bore testing (DST, injection tests, and fluid sampling), a variety of rock/fluid analyses, and a wide range of seismic attributes derived from a 3-D seismic survey to thoroughly characterize the highest-potential storage reservoirs and confining layers at the premier CO2 geological storage site in Wyoming. An accurate site characterization was essential to assessing the following critical aspects of the storage site: (1) more accurately estimate the CO2 reservoir storage capacity (Madison Limestone and Weber Sandstone at the Rock Springs Uplift (RSU)), (2) evaluate the distribution, long-term integrity, and permanence of the confining layers, (3) manage CO2 injection pressures by removing formation fluids (brine production/treatment), and (4) evaluate potential utilization of the stored CO2

  11. Effects of La2O3 on microstructure and wear properties of laser clad γ/Cr7C3/TiC composite coatings on TiAl intermatallic alloy

    International Nuclear Information System (INIS)

    Liu Xiubo; Yu Rongli

    2007-01-01

    The effects of La 2 O 3 addition on the microstructure and wear properties of laser clad γ/Cr 7 C 3 /TiC composite coatings on γ-TiAl intermetallic alloy substrates with NiCr-Cr 3 C 2 precursor mixed powders have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy-dispersive spectrometer (EDS) and block-on-ring wear tests. The responding wear mechanisms are discussed in detail. The results are compared with that for composite coating without La 2 O 3 . The comparison indicates that no evident new crystallographic phases are formed except a rapidly solidified microstructure consisting of the primary hard Cr 7 C 3 and TiC carbides and the γ/Cr 7 C 3 eutectics distributed in the tough γ nickel solid solution matrix. Good finishing coatings can be achieved under a proper amount of La 2 O 3 -addition and a suitable laser processing parameters. The additions of rare-earth oxide La 2 O 3 can refine and purify the microstructure of coatings, relatively decrease the volume fraction of primary blocky Cr 7 C 3 to Cr 7 C 3 /γ eutectics, reduce the dilution of clad material from base alloy and increase the microhardness of the coatings. When the addition of La 2 O 3 is approximately 4 wt.%, the laser clad composite coating possesses the highest hardness and toughness. The composite coating with 4 wt.%La 2 O 3 addition can result the best enhancement of wear resistance of about 30%. However, too less or excessive addition amount of La 2 O 3 have no better influence on wear resistance of the composite coating

  12. Cu-Cr Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Need, Ryan F. [Los Alamos National Laboratory

    2012-08-09

    Cu-Cr alloys are part of a class of face-centered cubic (FCC)-body-centered cubic (BCC) composites that includes similar alloys, such as Cu-Nb and Cu-Ta. When heavily deformed, these FCC-BCC materials create 'in situ' composites with a characteristic structure-nanoscale BCC filaments in a ductile FCC matrix. The strength of these composites is vastly greater than predicted by the rule of mixtures, and has been shown to be inversely proportional to the filament spacing. Lower raw materials costs suggest that Cu-Cr alloys may offer more economical solution to high-strength, high-conductivity wire than either their Nb or Ta counterparts. However, Cr is also more brittle and soluble in Cu than Nb or Ta. These qualities necessitate thermal treatments to remove solute atoms from the Cu matrix, improve conductivity, and maintain the ductility of the Cr filaments. Through the use of different thermomechanical processing routes or the addition of select dopants, alloys with strength in excess of 1 GPa at 70% IACS have been achieved. To date, previous research on Cu-Cr alloys has focused on a relatively small number of alloy compositions and processing methods while the effects of dopants and ageing treatments have only been studied independently. Consequently, there remains considerable opportunity for the development and optimization of these alloys as a leading high-strength, high-conductivity material.

  13. Effect of Cr content on the SHS reaction of Cr-Ti-C system

    International Nuclear Information System (INIS)

    Zhang, W.N.; Wang, H.Y.; Wang, P.J.; Zhang, J.; He, L.; Jiang, Q.C.

    2008-01-01

    The effect of Cr content on the self-propagating high temperature synthesis (SHS) reaction of Cr-Ti-C system has been investigated in this research. The thermodynamics calculation indicates that the TiC possesses higher thermodynamic stability than the Cr 23 C 6 , Cr 7 C 3 and Cr 3 C 2 phases, and the formation of TiC is the most exothermic. Additionally, the adiabatic combustion temperature (T ad ) decreases with the increase of Cr content except for the phase transition regions. The XRD result shows that the type of products synthesized by SHS changes that a higher Cr content corresponds to higher chromium carbide. When Cr content is 10 wt.%, only solid solution (Ti,Cr)C ss is formed in the products. When Cr content increases to 20 wt.%, besides (Ti,Cr)C ss , the Cr 7 C 3 phase is also detected. With the Cr content further increasing to 30 and 40 wt.%, the products consist of (Ti,Cr)C ss , Cr 23 C 6 , Cr 7 C 3 and Cr, and therefore, much higher chromium carbide is synthesized. When Cr content reaches 50 wt.%, however, the Cr 7 C 3 disappears and the final products become (Ti,Cr)C ss , Cr 23 C 6 and Cr. Moreover, when Cr content increases from 10 to 20 wt.%, the lattice parameter of (Ti,Cr)C ss decreases, while it increases when the Cr content ranges from 20 to 50 wt.%. Furthermore, the microstructure shows that the TiC particulate size decreases from ∼8 to ∼2 μm with the increase of Cr content from 10 to 50 wt.%, and the morphology shape of TiC particulate becomes more and more spherical

  14. Personnel neutron dosimetry using electrochemically etched CR-39 foils

    International Nuclear Information System (INIS)

    Hankins, D.E.; Homann, S.; Westermark, J.

    1986-01-01

    A personnel neutron dosimetry system has been developed based on the electrochemical etching of CR-39 plastic at elevated temperatures. The doses obtained using this dosimeter system are more accurate than those obtained using other dosimetry systems, especially when varied neutron spectra are encountered. This Cr-39 dosimetry system does not have the severe energy dependence that exists with albedo neutron dosimeters or the fading and reading problems encountered with NTA film. The dosimetry system employs an electrochemical etch procedure that be used to process large numbers of Cr-39 dosimeters. The etch procedure is suitable for operations where the number of personnel requires that many CR-39 dosimeters be processed. Experience shows that one full-time technician can etch and evaluate 2000 foils per month. The energy response to neutrons is fairly flat from about 80 keV to 3.5 MeV, but drops by about a factor of three in the 13 to 16 MeV range. The sensitivity of the dosimetry system is about 7 tracks/cm 2 /mrem, with a background equivalent to about 8 mrem for new CR-39 foils. The limit of sensitivity is approximately 10 mrem. The dosimeter has a significant variation in directional dependence, dropping to about 20% at 90 0 . This dosimeter has been used for personnel neutron dosimetry at the Lawrence Livermore National Laboratory for more tha 18 months. 6 refs., 23 figs., 2 tabs

  15. First-principles study on half-metallic zinc-blende CrS and its (001) surface

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Bin, E-mail: hnsqxb@163.com [Department of Mathematics and Information Sciences, North China university of Water Resources and Electric Power, Zhengzhou 450011 (China); Chen, Leiming [Zhengzhou Institute of Aeronautical Industry Management, Zhengzhou, 450015 (China)

    2016-11-01

    Half-metallic magnets with complete (100%) spin polarization have attracted growing interest due to the potential in spintronic applications. In this paper, we use the first-principles calculations to explain the seeming contradiction between the recent experimental ferromagnetism (Demper et al., 2012 [22]) and the previous theoretical antiferromagnetic ground state for half-metallic zinc-blende CrS, and the experimental ferromagnetism of zinc-blende CrS arises from the substrate effect. We also show that both Cr- and S-terminated (001) surfaces of CrS preserve the bulk half-metallicity. The calculated surface energy indicates that the S-terminated (001) surface is more stable than the Cr-terminated (001) surface within the whole effective Cr chemical potentials, and thus the S-terminated (001) surface is more likely than the Cr-terminated (001) surface when the CrS thin films are grown on ZnSe substrate.

  16. The Use Of Optical Properties Of Cr-39 In Alpha Particle Equivalent Dose Measurements

    International Nuclear Information System (INIS)

    Shnishin, K.A.

    2007-01-01

    In this work, optical properties of alpha irradiated Cr-39 were measured as a function of optical photon wavelength from 200-1100 nm. Optical energy gap and optical absorption at finite wavelength was also calculated and correlated to alpha fluence and dose equivalent. Alpha doses were calculated from the corresponding irradiation fluence and specific energy loss using TRIM computer program. It was found that, the optical absorption of unattached Cr-39 was varied with alpha fluence and corresponding equivalent doses. Also the optical energy gab was varied with fluence and dose equivalent of alpha particles. This work introduces a reasonably simple method for the Rn dose equivalent calculation by Cr-39 track

  17. Effects of Cr-N-ZrO 2 seed layer formed on glass substrates for longitudinal recording media

    Science.gov (United States)

    Suzuki, Hiroyuki; Djayaprawira, David D.; Takahashi, Yoshio; Ishikawa, Akira; Ono, Toshinori; Yahisa, Yotsuo

    1999-03-01

    Effects of Cr-N-ZrO 2 seed layer deposited on glass substrates before the deposition of C/Co-Cr-Pt/Cr-Ti layers for longitudinal recording media have been investigated. The product of v and Is, the activation volume and the saturation magnetization per unit volume, media noise Nd and S0/ Nd, which is the half value of peak-to-peak output voltage of an isolated pulse over Nd at 11.8 kFC/mm, are evaluated. We find that vIs is decreased by adding N and ZrO 2 to Cr seed layer. Nd is reduced as vIs decreases by adding nitrogen to the Cr seed layer. This is mainly due to the decreased grain sizes of both Cr-Ti underlayer and Co-Cr-Pt magnetic layer. The Nd is further reduced by the addition of ZrO 2 to the Cr-N seed layer. Highest S0/ Nd is achieved for the media with Cr-N-ZrO 2 seed layer. On the other hand, the media with Cr-ZrO 2 seed layer deposited without nitrogen show the higher Nd. Therefore the decrease of the grain size by addition of nitrogen into Ar is essential to reduce Nd, and the ZrO 2 addition to the Cr-N seed layer seems to enhance the effect of grain size reduction by nitrogen addition.

  18. Phase stability and elastic properties of Cr-V alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gao, M C; Suzuki, Y; Schweiger, H; Doğan, Ö N; Hawk, J; Widom, M

    2013-01-23

    V is the only element in the periodic table that forms a complete solid solution with Cr and thus is particularly important in alloying strategy to ductilize Cr. This study combines first-principles density functional theory calculations and experiments to investigate the phase stability and elastic properties of Cr–V binary alloys. The cluster expansion study reveals the formation of various ordered compounds at low temperatures that were not previously known. These compounds become unstable due to the configurational entropy of bcc solid solution as the temperature is increased. The elastic constants of ordered and disordered compounds are calculated at both T = 0 K and finite temperatures. The overall trends in elastic properties are in agreement with measurements using the resonant ultrasound spectroscopy method. The calculations predict that addition of V to Cr decreases both the bulk modulus and the shear modulus, and enhances the Poisson’s ratio, in agreement with experiments. Decrease in the bulk modulus is correlated to decrease in the valence electron density and increase in the lattice constant. An enhanced Poisson’s ratio for bcc Cr–V alloys (compared to pure Cr) is associated with an increased density of states at the Fermi level. Furthermore, the difference charge density in the bonding region in the (110) slip plane is highest for pure Cr and decreases gradually as V is added. The present calculation also predicts a negative Cauchy pressure for pure Cr, and it becomes positive upon alloying with V. The intrinsic ductilizing effect from V may contribute, at least partially, to the experimentally observed ductilizing phenomenon in the literature.

  19. African American Women: Surviving Breast Cancer Mortality against the Highest Odds

    Directory of Open Access Journals (Sweden)

    Shelley White-Means

    2015-12-01

    Full Text Available Among the country’s 25 largest cities, the breast cancer mortality disparity is highest in Memphis, Tennessee, where African American women are twice as likely to die from breast cancer as White women. This qualitative study of African-American breast cancer survivors explores experiences during and post treatment that contributed to their beating the high odds of mortality. Using a semi-structured interview guide, a focus group session was held in 2012 with 10 breast cancer survivors. Thematic analysis and a deductive a priori template of codes were used to analyze the data. Five main themes were identified: family history, breast/body awareness and preparedness to manage a breast cancer event, diagnosis experience and reaction to the diagnosis, family reactions, and impact on life. Prayer and family support were central to coping, and survivors voiced a cultural acceptance of racial disparities in health outcomes. They reported lack of provider sensitivity regarding pain, financial difficulties, negative responses from family/friends, and resiliency strategies for coping with physical and mental limitations. Our research suggested that a patient-centered approach of demystifying breast cancer (both in patient-provider communication and in community settings would impact how women cope with breast cancer and respond to information about its diagnosis.

  20. THE IMPACT OF FREQUENCY STANDARDS ON COHERENCE IN VLBI AT THE HIGHEST FREQUENCIES

    Energy Technology Data Exchange (ETDEWEB)

    Rioja, M.; Dodson, R. [ICRAR, University of Western Australia, Perth (Australia); Asaki, Y. [Institute of Space and Astronautical Science, 3-1-1 Yoshinodai, Chuou, Sagamihara, Kanagawa 252-5210 (Japan); Hartnett, J. [School of Physics, University of Western Australia, Perth (Australia); Tingay, S., E-mail: maria.rioja@icrar.org [ICRAR, Curtin University, Perth (Australia)

    2012-10-01

    We have carried out full imaging simulation studies to explore the impact of frequency standards in millimeter and submillimeter very long baseline interferometry (VLBI), focusing on the coherence time and sensitivity. In particular, we compare the performance of the H-maser, traditionally used in VLBI, to that of ultra-stable cryocooled sapphire oscillators over a range of observing frequencies, weather conditions, and analysis strategies. Our simulations show that at the highest frequencies, the losses induced by H-maser instabilities are comparable to those from high-quality tropospheric conditions. We find significant benefits in replacing H-masers with cryocooled sapphire oscillator based frequency references in VLBI observations at frequencies above 175 GHz in sites which have the best weather conditions; at 350 GHz we estimate a 20%-40% increase in sensitivity over that obtained when the sites have H-masers, for coherence losses of 20%-10%, respectively. Maximum benefits are to be expected by using co-located Water Vapor Radiometers for atmospheric correction. In this case, we estimate a 60%-120% increase in sensitivity over the H-maser at 350 GHz.

  1. Exchange Interactions on the Highest-Spin Reported Molecule: the Mixed-Valence Fe42 Complex

    Science.gov (United States)

    Aravena, Daniel; Venegas-Yazigi, Diego; Ruiz, Eliseo

    2016-04-01

    The finding of high-spin molecules that could behave as conventional magnets has been one of the main challenges in Molecular Magnetism. Here, the exchange interactions, present in the highest-spin molecule published in the literature, Fe42, have been analysed using theoretical methods based on Density Functional Theory. The system with a total spin value S = 45 is formed by 42 iron centres containing 18 high-spin FeIII ferromagnetically coupled and 24 diamagnetic low-spin FeII ions. The bridging ligands between the two paramagnetic centres are two cyanide ligands coordinated to the diamagnetic FeII cations. Calculations were performed using either small Fe4 or Fe3 models or the whole Fe42 complex, showing the presence of two different ferromagnetic couplings between the paramagnetic FeIII centres. Finally, Quantum Monte Carlo simulations for the whole system were carried out in order to compare the experimental and simulated magnetic susceptibility curves from the calculated exchange coupling constants with the experimental one. This comparison allows for the evaluation of the accuracy of different exchange-correlation functionals to reproduce such magnetic properties.

  2. Analisis Highest and Best Use (HBU pada Lahan Jl. Gubeng Raya No. 54 Surabaya

    Directory of Open Access Journals (Sweden)

    Akmaluddin Akmaluddin

    2013-03-01

    Full Text Available Laju pertumbuhan penduduk dan tingkat perekonomian yang semakin meningkat di  kota-kota besar seperti Surabaya, bertolak belakang dengan  ketersediaan lahan yang terbatas. Selayaknya properti yang akan dibangun di atas suatu lahan dapat memberikan manfaat yang maksimal serta efisien agar hasilnya dapat dirasakan demi pembangunan wilayah tersebut. Oleh karena itu, perlu dilakukan perhitungan  penggunaan yang paling memungkinkan dan diizinkan dari suatu tanah kosong atau tanah yang  sudah dibangun, dimana secara fisik dimungkinkan, didukung atau dibenarkan oleh peraturan, layak secara keuangan dan menghasilkan nilai tertinggi. Dalam penelitian ini dilakukan analisis Highest and Best Use (HBU pada lahan di Jl. Gubeng Raya No. 54 Surabaya seluas 1.150 m2 yang direncanakan akan dibangun hotel. Lahan tersebut berpotensi untuk dikembangkan menjadi properti komersial seperti hotel, apartemen, perkantoran dan pertokoan. Analisis tersebut menggunakan tinjauan terhadap aspek fisik, legal, finansial dan produktivitas maksimumnya. Dari hasil penelitian ini didapatkan alternatif properti komersial hotel yang memiliki penggunaan tertinggi dan terbaik pada pemanfaatan lahan dengan nilai lahan Rp. 67.069.980,31/ m2.

  3. Analisa Alternatif Revitalisasi Pasar Gubeng Masjid Surabaya dengan Metode Highest And Best Use

    Directory of Open Access Journals (Sweden)

    Marsha Swalia Mustika

    2017-01-01

    Full Text Available Dalam era globalisasi ini banyak bermunculan pasar-pasar modern yang dibangun dengan segala kelebihan dan fasilitasnya. Munculnya pasar-pasar modern membuat keberadaan pasar tradisional tersudut, tidak terkecuali Pasar Gubeng Masjid Surabaya. Namun keberadaan pasar yang strategis yaitu dekat dengan perkantoran, hotel dan pusat perbelanjaan, serta stasiun kereta api membuat pasar tersebut memiliki potensi untuk dikembangkan menjadi properti yang memberikan nilai lahan tertinggi dan terbaik. Oleh karena itu, perlu dilakukan analisa Highest and Best Use (HBU yang dapat memberikan masukan untuk melakukan investasi terbaik. Analisa HBU ini menggunakan empat kriteria yaitu secara fisik dimungkinkan, secara legal diizinkan , secara finansial layak, dan memiliki produktivitas maksimum. Alternatif yang memiliki produktivitas maksimum tersebut dapat dijadikan sebagai nilai lahan tertinggi dan terbaik pada lahan Pasar Gubeng Masjid Surabaya. Dari hasil penelitian didapatkan alternatif yang menghasilkan nilai lahan tertinggi dan produktivitas maksimum adalah alternatif pengembangan multi use pasar dengan pusat perbelanjaan.. Nilai lahan yang didapatkan sebesar Rp 46.946.524,-/m2 dengan produktivitas meningkat sebesar 312%.

  4. Transitional care for the highest risk patients: findings of a randomised control study

    Directory of Open Access Journals (Sweden)

    Kheng Hock Lee

    2015-10-01

    Full Text Available Background: Interventions to prevent readmissions of patients at highest risk have not been rigorously evaluated. We conducted a randomised controlled trial to determine if a post-discharge transitional care programme can reduce readmissions of such patients in Singapore. Methods: We randomised 840 patients with two or more unscheduled readmissions in the prior 90 days and Length of stay, Acuity of admission, Comorbidity of patient, Emergency department utilisation score ≥10 to the intervention programme (n = 419 or control (n = 421. Patients allocated to the intervention group received post-discharge surveillance by a multidisciplinary integrated care team and early review in the clinic. The primary outcome was the proportion of patients with at least one unscheduled readmission within 30 days after discharge. Results: We found no statistically significant reduction in readmissions or emergency department visits in patients on the intervention group compared to usual care. However, patients in the intervention group reported greater patient satisfaction (p < 0.001. Conclusion: Any beneficial effect of interventions initiated after discharge is small for high-risk patients with multiple comorbidity and complex care needs. Future transitional care interventions should focus on providing the entire cycle of care for such patients starting from time of admission to final transition to the primary care setting. Trial Registration: Clinicaltrials.gov, no NCT02325752

  5. Transitional care for the highest risk patients: findings of a randomised control study

    Directory of Open Access Journals (Sweden)

    Kheng Hock Lee

    2015-10-01

    Full Text Available Background: Interventions to prevent readmissions of patients at highest risk have not been rigorously evaluated. We conducted a randomised controlled trial to determine if a post-discharge transitional care programme can reduce readmissions of such patients in Singapore.Methods: We randomised 840 patients with two or more unscheduled readmissions in the prior 90 days and Length of stay, Acuity of admission, Comorbidity of patient, Emergency department utilisation score ≥10 to the intervention programme (n = 419 or control (n = 421. Patients allocated to the intervention group received post-discharge surveillance by a multidisciplinary integrated care team and early review in the clinic. The primary outcome was the proportion of patients with at least one unscheduled readmission within 30 days after discharge.Results: We found no statistically significant reduction in readmissions or emergency department visits in patients on the intervention group compared to usual care. However, patients in the intervention group reported greater patient satisfaction (p < 0.001.Conclusion: Any beneficial effect of interventions initiated after discharge is small for high-risk patients with multiple comorbidity and complex care needs. Future transitional care interventions should focus on providing the entire cycle of care for such patients starting from time of admission to final transition to the primary care setting.Trial Registration: Clinicaltrials.gov, no NCT02325752

  6. Measurement of radon concentration in dwellings in the region of highest lung cancer incidence in India

    International Nuclear Information System (INIS)

    Zoliana, B.; Rohmingliana, P.C.; Sahoo, B.K.; Mayya, Y.S.

    2015-01-01

    Monitoring of radon exhalation from soil and its concentration in indoor is found to be helpful in many investigations such as health risk assessment and others as radiation damage to bronchial cells which eventually can be the second leading cause of lung cancer next to smoking. The fact that Aizawl District, Mizoram, India has the highest lung cancer incidence rates among males and females in Age Adjusted Rate (AAR) in India as declared by Population Based Cancer Registry Report 2008 indicates the need for quantification of radon and its anomalies attached to it. Measurement of radon concentration had been carried out inside the dwellings in Aizawl district, Mizoram. A time integrated method of measurement was employed by using a solid state nuclear track detector (SSNTD) type (LR-115 films) kept in a twin cup dosimeter for measurement of concentration of radon and thoron. The dosimeters were suspended over bed rooms or living rooms in selected dwellings. They were deployed for a period of about 120 days at a time in 63 houses which were selected according to their place of location viz. fault region, places where fossil remains were found and geologically unidentified region. After the desired period of exposure, the detectors were retrieved and chemically etched which were then counted by using a spark counter. The recorded nuclear tract densities are then converted into air concentrations of Radon and Thoron

  7. A System with a Choice of Highest-Bidder-First and FIFO Services

    Directory of Open Access Journals (Sweden)

    Tejas Bodas

    2015-02-01

    Full Text Available Service systems using a highest-bidder-first (HBF policy have been studied in queueing literature for various applications and in economics literature to model corruption. Such systems have applications in modern problems like scheduling jobs in cloud computing scenarios or placement of ads on web pages. However, using a HBF service is like using a spot market and may not be preferred by many users. For such users, it may be good to provide a simple scheduler, e.g., a FIFO service. Further, in some situations it may even be necessary that a free service queue operates alongside a HBF queue. Motivated by such a scenario, we propose and analyze a service system with a FIFO server and a HBF server in parallel. Arriving customers are from a heterogeneous population with different valuations of their delay costs. They strategically choose between FIFO and HBF service; if HBF is chosen, they also choose the bid value to optimize an individual cost. We characterize the Wardrop equilibrium in such a system and analyze the revenue to the server. We see that when the total capacity is fixed and is shared between the FIFO and HBF servers, revenue is maximised when the FIFO capacity is non zero. However, if the FIFO server is added to an HBF server, then the revenue decreases with increasing FIFO capacity. We also discuss the case when customers are allowed to balk.

  8. African American Women: Surviving Breast Cancer Mortality against the Highest Odds

    Science.gov (United States)

    White-Means, Shelley; Rice, Muriel; Dapremont, Jill; Davis, Barbara; Martin, Judy

    2015-01-01

    Among the country’s 25 largest cities, the breast cancer mortality disparity is highest in Memphis, Tennessee, where African American women are twice as likely to die from breast cancer as White women. This qualitative study of African-American breast cancer survivors explores experiences during and post treatment that contributed to their beating the high odds of mortality. Using a semi-structured interview guide, a focus group session was held in 2012 with 10 breast cancer survivors. Thematic analysis and a deductive a priori template of codes were used to analyze the data. Five main themes were identified: family history, breast/body awareness and preparedness to manage a breast cancer event, diagnosis experience and reaction to the diagnosis, family reactions, and impact on life. Prayer and family support were central to coping, and survivors voiced a cultural acceptance of racial disparities in health outcomes. They reported lack of provider sensitivity regarding pain, financial difficulties, negative responses from family/friends, and resiliency strategies for coping with physical and mental limitations. Our research suggested that a patient-centered approach of demystifying breast cancer (both in patient-provider communication and in community settings) would impact how women cope with breast cancer and respond to information about its diagnosis. PMID:26703655

  9. A cosmopolitan design of teacher education and a progressive orientation towards the highest good

    Directory of Open Access Journals (Sweden)

    Klas Roth

    2013-01-01

    Full Text Available In this paper I discuss a Kantian conception of cosmopolitan education. It suggests that we pursue the highest good – an object of morality – in the world together, and requires that we acknowledge the value of freedom, render ourselves both efficacious and autonomous in practice, cultivate our judgment, and unselfishly co-operate in the co-ordination and fulfilment of our morally permissible ends. Now, such an accomplishment is one of the most difficult challenges, and may not be achieved in our time, if ever. In the first part of the paper I show that we, according to Kant, have to interact with each other, and comply with the moral law in the quest of general happiness, not merely personal happiness. In the second part, I argue that a cosmopolitan design of teacher education in Kantian terms can establish moral character, even though good moral character is ultimately the outcome of free choice. Such a design can do so by optimizing the freedom of those concerned to set and pursue their morally permissible ends, and to cultivate their judgment through the use of examples. This requires, inter alia, that they be enabled, and take responsibility, to think for themselves, in the position of everyone else, and consistently; and to strengthen their virtue or self-mastery to comply, in practice, with the moral law.

  10. Oxygen pathway modeling estimates high reactive oxygen species production above the highest permanent human habitation.

    Directory of Open Access Journals (Sweden)

    Isaac Cano

    Full Text Available The production of reactive oxygen species (ROS from the inner mitochondrial membrane is one of many fundamental processes governing the balance between health and disease. It is well known that ROS are necessary signaling molecules in gene expression, yet when expressed at high levels, ROS may cause oxidative stress and cell damage. Both hypoxia and hyperoxia may alter ROS production by changing mitochondrial Po2 (PmO2. Because PmO2 depends on the balance between O2 transport and utilization, we formulated an integrative mathematical model of O2 transport and utilization in skeletal muscle to predict conditions to cause abnormally high ROS generation. Simulations using data from healthy subjects during maximal exercise at sea level reveal little mitochondrial ROS production. However, altitude triggers high mitochondrial ROS production in muscle regions with high metabolic capacity but limited O2 delivery. This altitude roughly coincides with the highest location of permanent human habitation. Above 25,000 ft., more than 90% of exercising muscle is predicted to produce abnormally high levels of ROS, corresponding to the "death zone" in mountaineering.

  11. Medical school dropout--testing at admission versus selection by highest grades as predictors.

    Science.gov (United States)

    O'Neill, Lotte; Hartvigsen, Jan; Wallstedt, Birgitta; Korsholm, Lars; Eika, Berit

    2011-11-01

    Very few studies have reported on the effect of admission tests on medical school dropout. The main aim of this study was to evaluate the predictive validity of non-grade-based admission testing versus grade-based admission relative to subsequent dropout. This prospective cohort study followed six cohorts of medical students admitted to the medical school at the University of Southern Denmark during 2002-2007 (n=1544). Half of the students were admitted based on their prior achievement of highest grades (Strategy 1) and the other half took a composite non-grade-based admission test (Strategy 2). Educational as well as social predictor variables (doctor-parent, origin, parenthood, parents living together, parent on benefit, university-educated parents) were also examined. The outcome of interest was students' dropout status at 2 years after admission. Multivariate logistic regression analysis was used to model dropout. Strategy 2 (admission test) students had a lower relative risk for dropping out of medical school within 2 years of admission (odds ratio 0.56, 95% confidence interval 0.39-0.80). Only the admission strategy, the type of qualifying examination and the priority given to the programme on the national application forms contributed significantly to the dropout model. Social variables did not predict dropout and neither did Strategy 2 admission test scores. Selection by admission testing appeared to have an independent, protective effect on dropout in this setting. © Blackwell Publishing Ltd 2011.

  12. Extreme Markup: The Fifty US Hospitals With The Highest Charge-To-Cost Ratios.

    Science.gov (United States)

    Bai, Ge; Anderson, Gerard F

    2015-06-01

    Using Medicare cost reports, we examined the fifty US hospitals with the highest charge-to-cost ratios in 2012. These hospitals have markups (ratios of charges over Medicare-allowable costs) approximately ten times their Medicare-allowable costs compared to a national average of 3.4 and a mode of 2.4. Analysis of the fifty hospitals showed that forty-nine are for profit (98 percent), forty-six are owned by for-profit hospital systems (92 percent), and twenty (40 percent) operate in Florida. One for-profit hospital system owns half of these fifty hospitals. While most public and private health insurers do not use hospital charges to set their payment rates, uninsured patients are commonly asked to pay the full charges, and out-of-network patients and casualty and workers' compensation insurers are often expected to pay a large portion of the full charges. Because it is difficult for patients to compare prices, market forces fail to constrain hospital charges. Federal and state governments may want to consider limitations on the charge-to-cost ratio, some form of all-payer rate setting, or mandated price disclosure to regulate hospital markups. Project HOPE—The People-to-People Health Foundation, Inc.

  13. Highest-order optical phonon-mediated relaxation in CdTe/ZnTe quantum dots

    International Nuclear Information System (INIS)

    Masumoto, Yasuaki; Nomura, Mitsuhiro; Okuno, Tsuyoshi; Terai, Yoshikazu; Kuroda, Shinji; Takita, K.

    2003-01-01

    The highest 19th-order longitudinal optical (LO) phonon-mediated relaxation was observed in photoluminescence excitation spectra of CdTe self-assembled quantum dots grown in ZnTe. Hot excitons photoexcited highly in the ZnTe barrier layer are relaxed into the wetting-layer state by emitting multiple LO phonons of the barrier layer successively. Below the wetting-layer state, the LO phonons involved in the relaxation are transformed to those of interfacial Zn x Cd 1-x Te surrounding CdTe quantum dots. The ZnTe-like and CdTe-like LO phonons of Zn x Cd 1-x Te and lastly acoustic phonons are emitted in the relaxation into the CdTe dots. The observed main relaxation is the fast relaxation directly into CdTe quantum dots and is not the relaxation through either the wetting-layer quantum well or the band bottom of the ZnTe barrier layer. This observation shows very efficient optical phonon-mediated relaxation of hot excitons excited highly in the ZnTe conduction band through not only the ZnTe extended state but also localized state in the CdTe quantum dots reflecting strong exciton-LO phonon interaction of telluride compounds

  14. Which Environmental Factors Have the Highest Impact on the Performance of People Experiencing Difficulties in Capacity?

    Directory of Open Access Journals (Sweden)

    Verena Loidl

    2016-04-01

    Full Text Available Disability is understood by the World Health Organization (WHO as the outcome of the interaction between a health condition and personal and environmental factors. Comprehensive data about environmental factors is therefore essential to understand and influence disability. We aimed to identify which environmental factors have the highest impact on the performance of people with mild, moderate and severe difficulties in capacity, who are at risk of experiencing disability to different extents, using data from a pilot study of the WHO Model Disability Survey in Cambodia and random forest regression. Hindering or facilitating aspects of places to socialize in community activities, transportation and natural environment as well as use and need of personal assistance and use of medication on a regular basis were the most important environmental factors across groups. Hindering or facilitating aspects of the general environment were the most relevant in persons experiencing mild levels of difficulties in capacity, while social support, attitudes of others and use of medication on a regular basis were highly relevant for the performance of persons experiencing moderate to higher levels of difficulties in capacity. Additionally, we corroborate the high importance of the use and need of assistive devices for people with severe difficulties in capacity.

  15. Change of Cr atoms distribution in Fe85Cr15 alloy caused by 250 keV He+ ion irradiation to different doses

    International Nuclear Information System (INIS)

    Dubiel, S.M.; Żukrowski, J.

    2015-01-01

    Highlights: • Effect of He-ion irradiation dose on Fe 85 Cr 15 alloy. • Irradiation-induced clustering of Cr atoms. • Irradiation-caused reorientation of the surface magnetization vector. • Irradiation-caused increase of Fe-site spin-density. - Abstract: Redistribution of Cr atoms in a Fe 85 Cr 15 alloy caused by its irradiation with 250 keV He + ions to different doses, D = 8 ⋅ 10 16 , 16 ⋅ 10 16 and 48 ⋅ 10 16 ions/cm 2 was investigated by means of conversion electrons Mössbauer spectroscopy. The redistribution was expressed in terms of the Warren–Cowley short-range order parameters α 1 , α 2 and α 12 pertaining to the first (1NN), second (2NN) and both i.e. 1NN + 2NN shells, respectively. Clear evidence was found, both for non-irradiated and irradiated samples that the actual distribution of Cr atoms is characteristic of the shell, and for a given shell it depends on the irradiation dose. In particular, α 1 is positive, hence indicates an under population of Cr atoms in 1NN with respect to the random case, α 2 is negative, giving evidence thereby that 2NN is overpopulated by Cr atoms, and α 12 is weakly positive. Under the applied irradiation the number of Cr atoms in both neighbor shells decreased signifying thereby a clustering of Cr atoms. The underlying decrease of Cr concentration within the 1NN–2NN volume around the probe Fe atoms was estimated at 1.5 at.% ranging between 2.1 for the lowest and 0.8 at.% for the highest dose

  16. The study of Cr3+/Cr2+ redox system by polarographic method

    Directory of Open Access Journals (Sweden)

    S. A. Pokhmyolkina

    2014-08-01

    of redox Cr+3/ Cr+2. The specific reaction rate found by extrapolating the straight line constructed in the lgK = f (E coordinates to the equilibrium potential Ep. Equilibrium potential found by the Eyring method as half-wave potential for the reversible waves.We have constructed the initial currents of irreversible waves, considering that the beginning of irreversible and reversible waves practically coincide. Specific reaction rate (K is associated with activation energy given by: lgK= lg(ВТ/h∙ δ – ΔF/2,3RT, where: B is the Boltzmann constant, T is temperature Kelvin , h - Planck constant , δ - the distance between ions 2 ∙ 10-8 cm , R - universal gas constant , ΔF- changing activation energy. Substituting the values of the constants in the equation, we obtain an expression for calculating the activation energy: ΔF = 6,86∙103 – 1,35∙103lgК. An important characteristic of irreversible processes is the change in entropy, as the derivative of the entropy increment in time (diS / dt = ΔS. This quantity can be expressed in terms of current strength (J and overvoltage (η: ΔS = (diS / dt = 1 / T ∙ J η. In polarographic it indicates that the electrochemical process is complicated as compared with delivery of reactant to the electrode. With increasing temperature, we saw insignificant changes in the kinetic characteristics of both anodic and cathodic reduction of chromium salts. Obviously, accelerate the process of discharging ions prevents complication. Conclusion. This indicates a different state of ions of bivalent and trivalent chromium in solution and various ways of the electrode processes.

  17. pacientes crónicos

    Directory of Open Access Journals (Sweden)

    Lucy Barrera

    2007-01-01

    Full Text Available El presente artículo muestra cómo se ha construido una red de investigadores en el campo del cuidado a cuidadores de pacientes conenfermedad crónica. Presenta los principios y conceptos de las redes reconociendo el proceso, la aplicación y articulación a partir de lasexperiencias realizadas por el grupo académico flCuidado al paciente crónicofl de la Facultad de Enfermería de la Universidad Nacional, quegenera un estudio multicéntrico de investigación.

  18. Study of the oxidation of Fe-Cr alloys at high temperatures

    International Nuclear Information System (INIS)

    Carneiro, J.F.; Sabioni, A.C.S.

    2010-01-01

    The high temperature oxidation behavior of Fe-1.5%Cr, Fe-5.0%Cr, Fe-10%Cr and Fe- 15%Cr model alloys were investigated from 700 to 850 deg C, in air atmosphere. The oxidation treatments were performed in a thermobalance with a sensitivity of 1μg. The oxide films grown by oxidation of the alloys were characterized by scanning electronic microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The oxide films are Fe-Cr spinels with variable composition depending on the alloy composition. For all conditions studied, the oxidation kinetics of these alloys follow a parabolic law. The comparison of the oxidation rates of the four alloys, at 700 deg C, shows that the parabolic oxidation constants decrease from 1.96x10 -9 g 2 .cm -4 .s -1 , for the alloy Fe-1.5% Cr, to 1.18 x 10-14g 2 .cm -4 .s -1 for the alloy Fe-15% Cr. Comparative analysis of the oxidation behavior of the Fe-10%Cr and Fe-15%Cr alloys, between 700 and 850 deg C, shows that the oxidation rates of these alloys are comparable to 800 deg C, above this temperature the Fe-10%Cr alloy shows lower resistance to oxidation. (author)

  19. TSEE from Fe-Cr alloy system and its application to the estimation of gasoline deterioration

    International Nuclear Information System (INIS)

    Shimada, H.; Nakajima, K.

    1983-01-01

    The exoelectron glow curves for oxide surface on Fe-Cr alloy were measured as a function of Cr content. It was seen that with increasing Cr content the total counts of thermally stimulated exoelectron emission (TSEE), threshold temperature for measuring the glow curve (starting temperature of the glow curve) and the activation energy clearly indicate a good coincidence with the oxidation process of the surface. The interaction of Fe-Cr alloy with gasoline was examined by applying the test for the oxidation induced period (ASTM D525). The induction period became minimum at about 4%Cr, and the deposit of gasoline gum was maximum at its composition. The results were compared with that of TSEE, and it was found that the catalytic effect of Fe-Cr alloy on the deterioration of gasoline is explained from the starting temperature of the glow curves. (author)

  20. The response of CR-39 nuclear track detector to 1-9 MeV protons

    International Nuclear Information System (INIS)

    Sinenian, N.; Rosenberg, M. J.; Manuel, M.; McDuffee, S. C.; Casey, D. T.; Zylstra, A. B.; Rinderknecht, H. G.; Gatu Johnson, M.; Seguin, F. H.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.

    2011-01-01

    The response of CR-39 nuclear track detector (TasTrak) to protons in the energy range of 0.92-9.28 MeV has been studied. Previous studies of the CR-39 response to protons have been extended by examining the piece-to-piece variability in addition to the effects of etch time and etchant temperature; it is shown that the shape of the CR-39 response curve to protons can vary from piece-to-piece. Effects due to the age of CR-39 have also been studied using 5.5 MeV alpha particles over a 5-year period. Track diameters were found to degrade with the age of the CR-39 itself rather than the age of the tracks, consistent with previous studies utilizing different CR-39 over shorter time periods.

  1. Reduction of Cr(VI) in aqueous solution with DC diaphragm glow discharge

    International Nuclear Information System (INIS)

    Wang, Xiaoyan; Jin, Xinglong; Zhou, Minghua; Chen, Zhenhai; Deng, Kai

    2013-01-01

    This paper investigated the reduction of Cr(VI) in aqueous solution with direct current diaphragm glow discharge (DGD). The glow discharge sustained around the hole on a quartz tube which divided the electrolyte cell into two parts. The reduction efficiencies of Cr(VI) under different applied voltages, initial conductivities, hole diameters, hole numbers, initial pH values and initial concentrations were systematically studied. The results showed that the reduction efficiency of Cr(VI) increased with the increase of applied voltage, initial conductivity, hole diameter and hole number. The different initial pH values showed less effects on the reduction of Cr(VI). The reduction efficiency decreased with the increasing initial concentration. In addition, the simultaneous reduction of Cr(VI) and decolorization of acid orange (AO) with DGD were also fulfilled. Furthermore, the energy efficiency for Cr(VI) reduction with DGD was calculated and compared with those in photocatalysis and other glow discharge reactor

  2. Level crossing in a molecular Cr8 ring

    International Nuclear Information System (INIS)

    Affronte, M.; Guidi, T.; Caciuffo, R.; Carretta, S.; Amoretti, G.; Hinderer, J.; Sheikin, I.; Smith, A.A.; Winpenny, R.E.P.; Slageren, J. van; Gatteschi, D.

    2004-01-01

    The heat capacity of a molecular Cr 8 ring was measured as a function of temperature and magnetic field in order to follow the evolution of the Schottky anomaly through the first (S=0 to |1,-1>) level crossing occurring at B c1 =6.9 T. The results are interpreted within the framework of a spin Hamiltonian approach and they nicely fit the pattern of the energy levels derived by inelastic neutron spectroscopy. At B c1 , the Schottky anomaly almost vanishes suggesting that a true crossing occurs in Cr 8 in contrast to what was observed for ferric wheels

  3. Level crossing in a molecular Cr{sub 8} ring

    Energy Technology Data Exchange (ETDEWEB)

    Affronte, M. E-mail: affronte@unimore.it; Guidi, T.; Caciuffo, R.; Carretta, S.; Amoretti, G.; Hinderer, J.; Sheikin, I.; Smith, A.A.; Winpenny, R.E.P.; Slageren, J. van; Gatteschi, D

    2004-05-01

    The heat capacity of a molecular Cr{sub 8} ring was measured as a function of temperature and magnetic field in order to follow the evolution of the Schottky anomaly through the first (S=0 to |1,-1>) level crossing occurring at B{sub c1}=6.9 T. The results are interpreted within the framework of a spin Hamiltonian approach and they nicely fit the pattern of the energy levels derived by inelastic neutron spectroscopy. At B{sub c1}, the Schottky anomaly almost vanishes suggesting that a true crossing occurs in Cr{sub 8} in contrast to what was observed for ferric wheels.

  4. Capture cross sections for Cr, Fe and Ni

    International Nuclear Information System (INIS)

    Corvi, F.

    1990-01-01

    Since stainless steel represents about 25% of the volume of a fast power reactor, its constituent elements strongly influence its two main neutronic parameters: critical enrichment and breeding gain. Also, capture in the narrow p and d-wave resonances of Cr, Fe and Ni contributes as much as 10 to 15% of the Doppler coefficient of reactivity. Following sensitivity calculations, typical accuracy requirements in the energy range 0.1-100 keV are 5-10% for capture in Fe and 10-20% for capture in Ni and Cr. 11 refs, 2 tabs

  5. Sensitivity determination of CR-39 from Normal and inclined incidence

    International Nuclear Information System (INIS)

    Abou, A.A.; El-Kheir, A.A.; Daas, A.F.; Awwad, Z.; Reda, A.M.

    2000-01-01

    An experimental study have been carried out on alpha- particle track opening (Major and minor axes) using alpha-particles of different energies incident with different angels in addition to the normal incidence. The sensitivity of CR-39 in present work is determined for each of normal and inclined incidence. The results indicated a difference in the sensitivity according to angle of incidence. The variation of alpha- particle tracks (major and minor axes) are calculated and compared with our measured values. Also, it is found that the sensitivity of CR-39 detector is change due to the storage time at room temperature

  6. Information ranks highest: Expectations of female adolescents with a rare genital malformation towards health care services.

    Directory of Open Access Journals (Sweden)

    Elisabeth Simoes

    Full Text Available Access to highly specialized health care services and support to meet the patient's specific needs is critical for health outcome, especially during age-related transitions within the health care system such as with adolescents entering adult medicine. Being affected by an orphan disease complicates the situation in several important respects. Long distances to dedicated institutions and scarcity of knowledge, even among medical doctors, may present major obstacles for proper access to health care services and health chances. This study is part of the BMBF funded TransCareO project examining in a mixed-method design health care provisional deficits, preferences, and barriers in health care access as perceived by female adolescents affected by the Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS, a rare (orphan genital malformation.Prior to a communicative validation workshop, critical elements of MRKHS related care and support (items were identified in interviews with MRKHS patients. During the subsequent workshop, 87 persons involved in health care and support for MRKHS were asked to rate the items using a 7-point Likert scale (7, strongly agree; 1, strongly disagree as to 1 the elements' potential importance (i.e., health care expected to be "best practice", or priority and 2 the presently experienced care. A gap score between the two was computed highlighting fields of action. Items were arranged into ten separate questionnaires representing domains of care and support (e.g., online-portal, patient participation. Within each domain, several items addressed various aspects of "information" and "access". Here, we present the outcome of items' evaluation by patients (attended, NPAT = 35; respondents, NRESP = 19.Highest priority scores occurred for domains "Online-Portal", "Patient participation", and "Tailored informational offers", characterizing them as extremely important for the perception as best practice. Highest gap scores yielded domains

  7. Analysis of spectra of the Cr3+ impurities in a number of crystals with an account of Trees correction

    International Nuclear Information System (INIS)

    Grechushnikov, B.N.; Veremejchik, T.F.; Kalinkina, I.N.

    1977-01-01

    A diagram showing the Cr 3+ ion levels in the crystals of MgO, spinel (MgAl 2 O 4 ), garnet (Y 3 Al 5 O 12 ), emerald (BeAl 2 ) and corundum (SiO 3 ) 6 was calculated to elucidate the nature of the interaction described by the Trees correction αL (L+1) and the effect of the term on the accuracy of the calculations of the energy levels of admixed α 3 ions with d 3- -configurations. The calculation was performed in a semiempirical version of the crystalline field. The optimum parameters were found using a computer with account for the accuracy in estimating the said levels by the absorption spectra of the basis and excited states. The inclusion of the Trees correction, αL (L+1), in the calculation was shown to considerably improve the agreement between the calculated and experimentally obtained energy levels of Cr 3+ ions in the given crystals. The highest effect was observed in the range constituting the states 2 E, 2 T 1 and 2 T 2 (lines R, R' and B). Basing on an analysis of α value for these crystals, the conclusion was made that the term αL (L+1) chiefly described the interaction of the configurations

  8. Nonlinear Analysis to Detect if Excellent Nursing Work Environments Have Highest Well-Being.

    Science.gov (United States)

    Casalicchio, Giuseppe; Lesaffre, Emmanuel; Küchenhoff, Helmut; Bruyneel, Luk

    2017-09-01

    To detect potentially nonlinear associations between nurses' work environment and nurse staffing on the one hand and nurse burnout on the other hand. A cross-sectional multicountry study for which data collection using a survey of 33,731 registered nurses in 12 European countries took place during 2009 to 2010. A semiparametric latent variable model that describes both linear and potentially nonlinear associations between burnout (Maslach Burnout Inventory: emotional exhaustion, depersonalization, personal accomplishment) and work environment (Practice Environment Scale of the Nursing Work Index: managerial support for nursing, doctor-nurse collegial relations, promotion of care quality) and staffing (patient-to-nurse ratio). Similar conclusions are reached from linear and nonlinear models estimating the association between work environment and burnout. For staffing, an increase in the patient-to-nurse ratio is associated with an increase in emotional exhaustion. At about 15 patients per nurse, no further increase in emotional exhaustion is seen. Absence of evidence for diminishing returns of improving work environments suggests that continuous improvement and achieving excellence in nurse work environments pays off strongly in terms of lower nurse-reported burnout rates. Nurse staffing policy would benefit from a larger number of studies that identify specific minimum as well as maximum thresholds at which inputs affect nurse and patient outcomes. Nurse burnout is omnipresent and has previously been shown to be related to worse patient outcomes. Additional increments in characteristics of excellent work environments, up to the highest possible standard, correspond to lower nurse burnout. © 2017 Sigma Theta Tau International.

  9. Lost opportunities in HIV prevention: programmes miss places where exposures are highest

    Science.gov (United States)

    Sandøy, Ingvild F; Siziya, Seter; Fylkesnes, Knut

    2008-01-01

    Background Efforts at HIV prevention that focus on high risk places might be more effective and less stigmatizing than those targeting high risk groups. The objective of the present study was to assess risk behaviour patterns, signs of current preventive interventions and apparent gaps in places where the risk of HIV transmission is high and in communities with high HIV prevalence. Methods The PLACE method was used to collect data. Inhabitants of selected communities in Lusaka and Livingstone were interviewed about where people met new sexual partners. Signs of HIV preventive activities in these places were recorded. At selected venues, people were interviewed about their sexual behaviour. Peer educators and staff of NGOs were also interviewed. Results The places identified were mostly bars, restaurants or sherbeens, and fewer than 20% reported any HIV preventive activity such as meetings, pamphlets or posters. In 43% of places in Livingstone and 26% in Lusaka, condoms were never available. There were few active peer educators. Among the 432 persons in Lusaka and 676 in Livingstone who were invited for interview about sexual behaviour, consistent condom use was relatively high in Lusaka (77%) but low in Livingstone (44% of men and 34% of women). Having no condom available was the most common reason for not using one. Condom use in Livingstone was higher among individuals socializing in places where condoms always were available. Conclusion In the places studied we found a high prevalence of behaviours with a high potential for HIV transmission but few signs of HIV preventive interventions. Covering the gaps in prevention in these high exposure places should be given the highest priority. PMID:18218124

  10. How to identify the person holding the highest position in the criminal hierarchy?

    Directory of Open Access Journals (Sweden)

    Grigoryev D.A.

    2014-12-01

    Full Text Available The current version of the resolution of the RF Supreme Court Plenum of June 10, 2010 N 12, clarifying the provisions of the law on liability for crimes committed by a person holding the highest position in the criminal hierarchy (Part 4 of Article 210 of the RF Criminal Code, is criticized. Evaluative character of the considered aggravating circumstance doesn’t allow to develop clear criteria for identifying the leaders of the criminal environment. Basing on the theory provisions and court practice, the authors suggest three criteria. The first criterion is specific actions including: establishment and leadership of the criminal association (criminal organization; coordinating criminal acts; creating sustainable links between different organized groups acting independently; dividing spheres of criminal influence, sharing criminal income and other criminal activities, indicating person’s authority and leadership in a particular area or in a particular sphere of activity. The second is having money, valuables and other property obtained by criminal means, without the person’s direct participation in their acquisition; transferring money, valuables and other property to that person systematically, without legal grounds (unjust enrichment; spending that money, valuables and other property to carry out criminal activities (crimes themselves and conditions of their commission. The third is international criminal ties manifested in committing one of the crimes under Part 1 of Article 210 of the RF Criminal Code, if this crime is transnational in nature; ties with extremist and (or terrorist organizations, as well as corruption ties. The court may use one or several of these criteria.

  11. Analisa Penggunaan Tertinggi dan Terbaik (Highest and Best Use Analysis pada Lahan Pasar Turi Lama Surabaya

    Directory of Open Access Journals (Sweden)

    Maulida Herradiyanti

    2017-01-01

    Full Text Available Pasar  Turi  merupakan  pasar  yang  telah lama  menjadi  ikon  perdagangan  tidak  hanya  di Surabaya,  namun  juga  di  Indonesia  Timur.  Kebakaran hebat yang terjadi pada Juli 2007 telah menghanguskan bangunan Pasar Turi. Aktivitas perdagangan di tempat tersebut  otomatis  terhenti.  Hingga saat ini, lahan Pasar Turi  Tahap  III  atau  yang  biasa  disebut  Pasar  Turi Lama  masih  terbengkalai.  Padahal,  lahan  seluas  16281 m2tersebut terletak di wilayah sentra perdagangan dan cocok  untuk  dikembangkan  menjadi properti komersial seperti perkantoran, pertokoan, rumah toko (ruko, danpasar tradisional. Salah  satu  cara  untuk  menentukan  penggunaan lahan Pasar Turi Lama adalah dengan metode Highest and  Best  Use  (HBU.  HBU  adalah  suatu  metode  untuk menentukan  penggunaan  aset  yang  memberikan peruntukan  paling  optimal sehingga dapat memberikan nilai  lahan  tertinggi.  Kriteria  HBU  yaitu  diijinkan secara  legal,  memungkinkan  secara  fisik,  layak  secara finansial, dan memiliki produktivitas maksimum.Hasil penelitian ini didapatkan alternatif pertokoan sebagai  alternatif  penggunaan  lahan  terbaik  dengan nilai  lahan  tertinggi  yaitu  sebesar  Rp27.994.695,78/m2dengan produktivitas maksimum sebesar  124%.

  12. Risk of influenza transmission in a hospital emergency department during the week of highest incidence.

    Science.gov (United States)

    Esteve-Esteve, Miguel; Bautista-Rentero, Daniel; Zanón-Viguer, Vicente

    2018-02-01

    To estimate the risk of influenza transmission in patients coming to a hospital emergency department during the week of highest incidence and to analyze factors associated with transmission. Retrospective observational analysis of a cohort of patients treated in the emergency room during the 2014-2015 flu season. The following variables were collected from records: recorded influenza diagnosis, results of a rapid influenza confirmation test, point of exposure (emergency department, outpatient clinic, or the community), age, sex, flu vaccination or not, number of emergency visits, time spent in the waiting room, and total time in the hospital. We compiled descriptive statistics and performed bivariate and multivariate analyses by means of a Poisson regression to estimate relative risk (RR) and 95% CIs. The emergency department patients had a RR of contracting influenza 3.29 times that of the communityexposed population (95% CI, 1.53-7.08, P=.002); their risk was 2.05 times greater than that of outpatient clinic visitors (95% CI, 1.04-4.02, P=.036). Emergency patients under the age of 15 years had a 5.27 greater risk than older patients (95% CI, 1.59-17.51; P=.007). The RR of patients visiting more than once was 11.43 times greater (95% CI, 3.58-36.44; P<.001). The risk attributable to visiting the emergency department risk was 70.5%, whereas risk attributable to community exposure was 2%. The risk of contracting influenza is greater for emergency department patients than for the general population or for patients coming to the hospital for outpatient clinic visits. Patients under the age of 15 years incur greater risk.

  13. Towards highest peak intensities for ultra-short MeV-range ion bunches

    OpenAIRE

    Simon Busold; Dennis Schumacher; Christian Brabetz; Diana Jahn; Florian Kroll; Oliver Deppert; Ulrich Schramm; Thomas E. Cowan; Abel Blažević; Vincent Bagnoud; Markus Roth

    2015-01-01

    A laser-driven, multi-MeV-range ion beamline has been installed at the GSI Helmholtz center for heavy ion research. The high-power laser PHELIX drives the very short (picosecond) ion acceleration on ?m scale, with energies ranging up to 28.4?MeV for protons in a continuous spectrum. The necessary beam shaping behind the source is accomplished by applying magnetic ion lenses like solenoids and quadrupoles and a radiofrequency cavity. Based on the unique beam properties from the laser-driven so...

  14. Influence of Mo addition on the tempered properties of 13Cr martensitic stainless steel

    International Nuclear Information System (INIS)

    Jung, Byong Ho; Ahn, Yong Sik

    1998-01-01

    In order to investigate the effect of Mo addition on the mechanical properties of 13Cr-0.2C martensitic stainless steel, tensile test and Charpy V-notch test were performed after tempering at the temperature range of 200∼700 .deg. C following austenitizing at 1100 .deg. C. The yield strength and hardness of the steel were increased with the increase of Mo content at all tempering conditions, because Mo causes retardation of precipitation and coarsening of carbides and solid solution strengthening of matrix. Except 500 .deg. C of tempering temperature, the Charpy impact energy was significantly increased with Mo content and showed the highest value at 1.5 wt% addition. The increase of impact energy of the steel containing Mo is thought to be caused by δ-ferrite formed in the tempered martensitic matrix. At 500 .deg. C tempering, Charpy impact energy was decreased drastically due to temper embrittlement and it was not possible to prevent it even though Mo was added up to 1.5 wt%

  15. Confinement in a cryogenic Penning trap of highest charge state ions from EBIT

    International Nuclear Information System (INIS)

    Schneider, D.

    1994-01-01

    The retrapping of highly charged Xe 44+ and Th 68+,72+ ions extracted from an open-quotes Electron Beam Ion Trapclose quotes (EBIT) is demonstrated after injection of the ions into RETRAP, a cryogenic Penning trap (up to 6 Tesla magnetic field) currently with an open cylinder design. Ion extraction in a short pulse (5-20 μsec) from EBIT, essential for efficient retrapping, is employed. The ions are slowed down upon entering a deceleration tube mounted above the trap within the magnetic field. The potential is then rapidly (100 ns) decreased, enabling low energy ions to enter the trap. Capture efficiencies up to 25% are observed via detection of the delayed ion release pulse with a detector below the trap. Signal voltages induced in a tuned circuit due to single and multiple ions have been observed by tuning the ion resonant axial oscillation frequencies for different ions. Results from transporting and retrapping of the ions, as well as their detection, are described and the trapping efficiency is discussed, The motivation for these studies is to cool the trapped very highly charged ions to low temperatures (< 4 K) in order to perform ultrahigh resolution precision spectroscopy, collision studies at ultra low energies and to observe phase transitions in Coulomb clusters of highly charged ions

  16. Thermodynamic properties of CdCr2S4

    International Nuclear Information System (INIS)

    Kesler, Ya.A.; Shchelkotunov, V.A.; Tret'yakov, Yu.D.; Kamyshova, V.K.; Gordeev, I.V.; Alferov, V.A.

    1977-01-01

    The true thermal capacity of ferromagnetic chromium spinel CdCr 2 S 4 has been measured in the temperature range of 172-673 K. Coefficient of linear expansion has been measured in the temperature range of 173-677 K. A change in heat content of the compound has been found by the mixing method (298-750 K). The lattice contribution into thermal capacity, the contribution of thermal expansion, the values of isothermal compressibility factor, and the Crueneisen constants have been calculated from true and mean heat capacity of CdCr 2 S 4 in a wide temperature range. The lattice energy V has been calculated for CdCr 2 S 4 ; it amounts -4226 kcal/mol

  17. Chromium 51 em K2CrO4: reactions of dopant atoms in solid state

    International Nuclear Information System (INIS)

    Valim, J.B.; Nascimento, R.L.G. do; Collins, C.H.; Collins, K.E.

    1986-01-01

    The study of the chemistry of 'dopant' 51 Cr(III) atoms in crystalline Cr(VI) compounds began as a sub-field of Hot Atom Chemistry. We shall review the attempts to use 'dopant' chromium-51 atoms as surrogate chromium recoil atoms with the special property of having a low-energy, recoil-dam-age-free history. These dopant atoms have shown behaviors very similar to those of high energy recoil 51 Gr atoms, thus offering little hope of learning about special damage site structures and reactions by behavioral differences. Recent work has shown that at least some of the 'dopant' 51 Cr(III) is present as a second, non-chromate solid phase in 'doped crystal' experiments. Monodisperse 51 Cr(OH) 3 particles mixed with pure K 2 CrO 4 are very reactive. (Author) [pt

  18. Hardening of Fe-Cr-Mn steels cold plastic working

    International Nuclear Information System (INIS)

    Malinov, L.S.; Konop-Lyashko, V.I.; Nikoporets, N.M.

    1983-01-01

    The dependence is established between the level of proper-- ties obtained after cold plastic working and development of martensite transformations when loading in Fe-Cr-Mn steels containing 0.1-0.5% C, 13% Cr, 8-12% Mn, as well as in a number of complex alloyed steels. It is shown that the highest level of mechanical properties can be obtained after cold plastic working only in steels with definite austenite stability. Cold plastic working can both activize and stabilize austenite relatively to martensite formation during loading. The first thing is found when under the effect of preliminary cold working dislocation splitting takes place, as well as the formation of a small amount of E-phase and martensite. The second thing manifests itself when under the effect of cold working performed above Md (Md<20 deg C) cell dislocation structure is formed and dislocation pinning takes place

  19. Advances in the development of Cr-39 based neutron dosimeters

    International Nuclear Information System (INIS)

    Hadlock, D.E.; Parkhurst, M.A.

    1987-12-01

    A combination thermoluminescent dosimeter (TLD) and track etch dosimeter (TED), which can be used for detecting neutrons over a wide energy range, has been developed through recent research in passive neutron dosimetery. This dosimeter uses Li-600 TLDs to detect thermal and low energy neutrons reflected from the body, and the TED polymer of CR-39, to detect fast neutrons from proton recoil interactions with the polyethylene radiator or with CR-39 itself. Some form of the combination dosimeter is currently in use at several US Department of Energy (DOE) facilities, and its use is expected to expand over the next year to include all DOE facilities where significant neutron exposures may occur. The extensive research conducted on the TED component over the past six years has continually focused on material improvements, reduction in processing time and dosimeter handling, and ease of sample readout with the goal of automating the process as much as possible. 1 fig

  20. Breaststroke swimmers moderate internal work increases toward the highest stroke frequencies.

    Science.gov (United States)

    Lauer, Jessy; Olstad, Bjørn Harald; Minetti, Alberto Enrico; Kjendlie, Per-Ludvik; Rouard, Annie Hélène

    2015-09-18

    A model to predict the mechanical internal work of breaststroke swimming was designed. It allowed us to explore the frequency-internal work relationship in aquatic locomotion. Its accuracy was checked against internal work values calculated from kinematic sequences of eight participants swimming at three different self-chosen paces. Model predictions closely matched experimental data (0.58 ± 0.07 vs 0.59 ± 0.05 J kg(-1)m(-1); t(23)=-0.30, P=0.77), which was reflected in a slope of the major axis regression between measured and predicted total internal work whose 95% confidence intervals included the value of 1 (β=0.84, [0.61, 1.07], N=24). The model shed light on swimmers ability to moderate the increase in internal work at high stroke frequencies. This strategy of energy minimization has never been observed before in humans, but is present in quadrupedal and octopedal animal locomotion. This was achieved through a reduced angular excursion of the heaviest segments (7.2 ± 2.9° and 3.6 ± 1.5° for the thighs and trunk, respectively, Paquatic movements. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Consumer Airfare Report: Table 5 - Detailed Fare Information For Highest and Lowest Fare Markets Under 750 Miles

    Data.gov (United States)

    Department of Transportation — Provides detailed fare information for highest and lowest fare markets under 750 miles. For a more complete explanation, please read the introductory information at...

  2. Crystal structure, Raman scattering and magnetic properties of CuCr2-xZrxSe4 and CuCr2-xSnxSe4 selenospinels

    Science.gov (United States)

    Pinto, C.; Galdámez, A.; Barahona, P.; Moris, S.; Peña, O.

    2018-06-01

    Selenospinels, CuCr2-xMxSe4 (M = Zr and Sn), were synthesized via conventional solid-state reactions. The crystal structure of CuCr1.5Sn0.5Se4, CuCr1.7Sn0.3Se4, CuCr1.5Zr0.5Se4, and CuCr1.8Zr0.2Se4 were determined using single-crystal X-ray diffraction. All the phases crystallized in a cubic spinel-type structure. The chemical compositions of the single-crystals were examined using energy-dispersive X-ray analysis (EDS). Powder X-ray diffraction patterns of CuCr1.3Sn0.7Se4 and CuCr1.7Sn0.3Se4 were consistent with phases belonging to the Fd 3 bar m Space group. An analysis of the vibrational properties on the single-crystals was performed using Raman scattering measurements. The magnetic properties showed a spin glass behavior with increasing Sn content and ferromagnetic order for CuCr1.7Sn0.3Se4.

  3. Defect properties of CuCrO2: A density functional theory calculation

    International Nuclear Information System (INIS)

    Fang Zhi-Jie; Zhu Ji-Zhen; Zhou Jiang; Mo Man

    2012-01-01

    Using the first-principles methods, we study the formation energetics properties of intrinsic defects, and the charge doping properties of extrinsic defects in transparent conducting oxides CuCrO 2 . Intrinsic defects, some typical acceptor-type, and donor-type extrinsic defects in their relevant charge state are considered. By systematically calculating the formation energies and transition energy, the results of calculation show that, V Cu , O i , and O Cu are the relevant intrinsic defects in CuCrO 2 ; among these intrinsic defects, V Cu is the most efficient acceptor in CuCrO 2 . It is found that all the donor-type extrinsic defects have difficulty in inducing n-conductivity in CuCrO 2 because of their deep transition energy level. For all the acceptor-type extrinsic defects, substituting Mg for Cr is the most prominent doping acceptor with relative shallow transition energy levels in CuCrO 2 . Our calculation results are expected to be a guide for preparing promising n-type and p-type materials in CuCrO 2 . (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  4. Comparison of the Isothermal Oxidation Behavior of As-Cast Cu-17%Cr and Cu-17%Cr-5%Al. Part 1; Oxidation Kinetics

    Science.gov (United States)

    Raj. Sai V.

    2008-01-01

    The isothermal oxidation kinetics of as-cast Cu-17%Cr and Cu-17%Cr-5%Al in air were studied between 773 and 1173 K under atmospheric pressure. These observations reveal that Cu- 17%Cr-5%Al oxidizes at significantly slower rates than Cu-17%Cr. The rate constants for the alloys were determined from generalized analyses of the data without an a priori assumption of the nature of the oxidation kinetics. Detailed analyses of the isothermal thermogravimetric weight change data revealed that Cu-17%Cr exhibited parabolic oxidation kinetics with an activation energy of 165.9 9.5 kJ mol-1. In contrast, the oxidation kinetics for the Cu-17%Cr- 5%Al alloy exhibited a parabolic oxidation kinetics during the initial stages followed by a quartic relationship in the later stages of oxidation. Alternatively, the oxidation behavior of Cu-17%CR- 5%Al could be better represented by a logarithmic relationship. The parabolic rate constants and activation energy data for the two alloys are compared with literature data to gain insights on the nature of the oxidation mechanisms dominant in these alloys.

  5. Comparison of the Isothermal Oxidation Behavior of As-Cast Cu-17 Percent Cr and Cu-17 Percent Cr-5 Percent Al. Part 1; Oxidation Kinetics

    Science.gov (United States)

    Raj, S. V.

    2008-01-01

    The isothermal oxidation kinetics of as-cast Cu-17%Cr and Cu-17%Cr-5%Al in air were studied between 773 and 1173 K under atmospheric pressure. These observations reveal that Cu-17%Cr-5%Al oxidizes at significantly slower rates than Cu-17%Cr. The rate constants for the alloys were determined from generalized analyses of the data without an a priori assumption of the nature of the oxidation kinetics. Detailed analyses of the isothermal thermogravimetric weight change data revealed that Cu-17%Cr exhibited parabolic oxidation kinetics with an activation energy of 165.9+/-9.5 kJ/mol. In contrast, the oxidation kinetics for the Cu-17%Cr-5%Al alloy exhibited a parabolic oxidation kinetics during the initial stages followed by a quartic relationship in the later stages of oxidation. Alternatively, the oxidation behavior of Cu-17%CR-5%Al could be better represented by a logarithmic relationship. The parabolic rate constants and activation energy data for the two alloys are compared with literature data to gain insights on the nature of the oxidation mechanisms dominant in these alloys.

  6. Metabolic Effects of CX3CR1 Deficiency in Diet-Induced Obese Mice.

    Directory of Open Access Journals (Sweden)

    Rachana Shah

    Full Text Available The fractalkine (CX3CL1-CX3CR1 chemokine system is associated with obesity-related inflammation and type 2 diabetes, but data on effects of Cx3cr1 deficiency on metabolic pathways is contradictory. We examined male C57BL/6 Cx3cr1-/- mice on chow and high-fat diet to determine the metabolic effects of Cx3cr1 deficiency. We found no difference in body weight and fat content or feeding and energy expenditure between Cx3cr1-/- and WT mice. Cx3cr1-/- mice had reduced glucose intolerance assessed by intraperitoneal glucose tolerance tests at chow and high-fat fed states, though there was no difference in glucose-stimulated insulin values. Cx3cr1-/- mice also had improved insulin sensitivity at hyperinsulinemic-euglycemic clamp, with higher glucose infusion rate, rate of disposal, and hepatic glucose production suppression compared to WT mice. Enhanced insulin signaling in response to acute intravenous insulin injection was demonstrated in Cx3cr1-/- by increased liver protein levels of phosphorylated AKT and GSK3β proteins. There were no differences in adipose tissue macrophage populations, circulating inflammatory monocytes, adipokines, lipids, or inflammatory markers. In conclusion, we demonstrate a moderate and reproducible protective effect of Cx3cr1 deficiency on glucose intolerance and insulin resistance.

  7. Ab initio study of Cr interactions with point defects in bcc Fe

    International Nuclear Information System (INIS)

    Olsson, P.; Domain, Ch.; Wallenius, J.

    2008-01-01

    Full text of publication follows. Ferritic martensitic steels are candidate structural materials for fast neutron reactors, and in particular high-Cr reduced-activation steels. In Fe-Cr alloys, Cr plays a major role in the radiation-induced evolution of the mechanical properties. Using ab initio calculations based on density functional theory, the properties of Cr in α-Fe have been investigated. The intrinsic point defect formation energies were found to be larger in model bcc Cr as compared to those in ferromagnetic bcc Fe. The interactions of Cr with point defects (vacancy and self interstitials) have been characterised. Single Cr atoms interact weakly with vacancies but significantly with self-interstitial atoms. Mixed interstitials of any interstitial symmetry are bound. Configurations where two Cr atoms are in nearest neighbour position are generally unfavourable in bcc Fe except when they are a part of a interstitial complex. Mixed interstitials do not have as strong directional stability as pure Fe interstitials have. The effects on the results using the atom description scheme of either the ultrasoft pseudo-potential (USPP) or the projector augmented wave (PAW) formalisms are connected to the differences in local magnetic moments that the two methods predict. As expected for the Fe-Cr system, the results obtained using the PAW method are more reliable than the ones obtained with USPP. (authors)

  8. Microstructure and mechanical properties of nanostructure multilayer CrN/Cr coatings on titanium alloy

    International Nuclear Information System (INIS)

    Wiecinski, Piotr; Smolik, Jerzy; Garbacz, Halina; Kurzydlowski, Krzysztof J.

    2011-01-01

    Five different nanostructured, multilayer coatings (CrN/Cr)x8 with different thickness ratio of Cr and CrN layers were deposited by PAPVD (Plasma Assisted Physical Vapour Deposition) vacuum arc method on Ti6Al4V titanium alloy. The microstructure, chemical and phase composition of the CrN and Cr sub-layers were characterized by SEM with EDX and Cs-corrected dedicated STEM on cross-sections prepared by focus ion beam. Besides, hardness and Young's modulus of the (Cr/CrN)x8 coatings has been measured. The adhesion has been tested by scratch test method. The obtained (CrN/Cr) multilayer coatings, 5-6 μm in thickness, have homogeneous and nanocrystalline structure, free of pores and cracks. The microstructures of Cr and CrN layers consist of columnar grains below 100 nm in diameter. The hardness and Young's modulus of these coatings depend linearly on thickness ratio of Cr and CrN layers. The decrease of the thickness ratio Cr/CrN 0.81 to 0.15 results in the increase of hardness from 1275 HV to 1710 HV and Young's modulus from 260 GPa to 271 GPa.

  9. Beta decay of 46Cr

    International Nuclear Information System (INIS)

    Onishi, T K; Gelberg, A; Sakurai, H; Yoneda, K; Aoi, N; Imai, N; Baba, H; Brentano, P von; Fukuda, N; Ichikawa, Y; Ishihara, M; Iwasaki, H; Kameda, D; Kishida, T; Lisetskiy, A F; Ong, H J; Osada, M; Otsuka, T; Suzuki, M K; Ue, K; Utsuno, Y; Watanabe, H

    2006-01-01

    The Gamow-Teller transition of 46 Cr to the N = Z odd-odd nucleus 46 V has been observed for the first time. By means of β-γ coincidence measurements, a γ-ray peak at 993 keV corresponding to the decay of the 1 + 1 state in 46 V was observed. The branching ratio of the decay to this state was found to be b GT = 0.25 ± 0.050. The half-life of 46 Cr was measured to be T 1/2 = 240 ± 140 ms. The transition strength was determined to be B(GT) = 0.64 ± 0.20. This result was compared with theoretical calculations

  10. Simulation of radiation damage in Fe and Fe-Cr

    International Nuclear Information System (INIS)

    Lagerstedt, Christina

    2005-11-01

    Steel is an important structural material in nuclear reactors used for example in pressure vessels and fast reactor cladding. In reactor environments it has been observed that ferritic steels are more resistant to swelling than the austenitic steels typically used. Much effort has been put into developing basic models of FeCr alloys which can serve as model alloys for describing ferritic steels. As a result, a number of interatomic potentials for Fe and FeCr alloys exist today. For the work in this thesis, basic material properties coming from experiments or ab initio calculations were used to fit interatomic potentials for Fe, Cr and FeCr implementing both the embedded atom method and the Finnis-Sinclair formalisms. The potentials were then validated by molecular dynamic calculations of material properties such as defect formation energies, migration energies and thermal expansion. Further studies of potential performance were carried out in simulations of radiation damage cascades and thermal aging. The influence of the interatomic potential on the primary defect state in materials under irradiation was analyzed in a study comparing results obtained using four different potentials. The objective of the study was to find correlations between potential properties and the primary damage state produced in simulations of displacement cascades. The defect evolution and clustering during different cascade stages were also investigated to try to gain a better understanding of these processes

  11. A CR-39 track dosemeter for routine individual neutron monitoring

    International Nuclear Information System (INIS)

    Luszik-Bhadra, M.; Alberts, W.G.; Dietz, E.; Guldbakke, S.; Matzke, M.; d'Errico, F.

    1994-01-01

    A personal neutron dosemeter for routine individual monitoring is proposed. It is based on a CR-39 track detector covered on three separate areas by converters with different boron contents and inserted into a commercial TLD albedo dosemeter capsule. The dose readings from three areas of the electrochemically etched CR-39 detector are combined to yield a dose equivalent response which is almost independent of the incident neutron energy in the range from thermal neutrons up to 20 MeV. In addition, the dose contributions of thermal, intermediate and fast neutrons can be determined separately. Unlike the TLD albedo dosemeter, which in general requires prior in-field calibration and whose use is then restricted to that field, this dosemeter can be used in neutron fields without any knowledge of the spectral distribution with the same calibration factor. The angular dependence of the dosemeter's response has been measured and compared with that of the directional dose equivalent H'(10). The lower limit of detection is 0.15 mSv. It is possible to obtain an independent, second dose reading from the same Cr-39 detector for neutron energies above 100 keV. The dosemeter has also been successfully tested for use in accident dosimetry applying chemical etching and an optical density reading of the CR-39 detector. (author)

  12. Observations of defect structure evolution in proton and Ni ion irradiated Ni-Cr binary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, Samuel A., E-mail: sabriggs2@wisc.edu [University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706 (United States); Barr, Christopher M. [Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Pakarinen, Janne [University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706 (United States); SKC-CEN Belgian Nuclear Research Centre, Boeretang 200, B-2400 Mol (Belgium); Mamivand, Mahmood [University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706 (United States); Hattar, Khalid [Sandia National Laboratories, PO Box 5800, Albuquerque, NM 87185 (United States); Morgan, Dane D. [University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706 (United States); Taheri, Mitra [Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Sridharan, Kumar [University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706 (United States)

    2016-10-15

    Two binary Ni-Cr model alloys with 5 wt% Cr and 18 wt% Cr were irradiated using 2 MeV protons at 400 and 500 °C and 20 MeV Ni{sup 4+} ions at 500 °C to investigate microstructural evolution as a function of composition, irradiation temperature, and irradiating ion species. Transmission electron microscopy (TEM) was applied to study irradiation-induced void and faulted Frank loops microstructures. Irradiations at 500 °C were shown to generate decreased densities of larger defects, likely due to increased barriers to defect nucleation as compared to 400 °C irradiations. Heavy ion irradiation resulted in a larger density of smaller voids when compared to proton irradiations, indicating in-cascade clustering of point defects. Cluster dynamics simulations were in good agreement with the experimental findings, suggesting that increases in Cr content lead to an increase in interstitial binding energy, leading to higher densities of smaller dislocation loops in the Ni-18Cr alloy as compared to the Ni-5Cr alloy. - Highlights: • Binary Ni-Cr alloys were irradiated with protons or Ni ions at 400 and 500 °C. • Higher irradiation temperatures yield increased size, decreased density of defects. • Hypothesize that varying Cr content affects interstitial binding energy. • Fitting CD models for loop nucleation to data supports this hypothesis.

  13. Atomic investigation of alloying Cr, Ti, Y additions in a grain boundary of vanadium

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Pengbo, E-mail: zhangpb@dlmu.edu.cn [Department of Physics, Dalian Maritime University, Dalian 116026 (China); Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Ministry of Education, Dalian 116024 (China); Li, Xiaojie; Zhao, Jijun [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Ministry of Education, Dalian 116024 (China); Zheng, Pengfei; Chen, Jiming [Southwestern Institute of Physics, Chengdu 610041 (China)

    2016-01-15

    The effect of alloying additions (Cr, Ti and Y) in a vanadium (V) ∑3 (111) grain boundary (GB) is investigated by first-principles calculations. To determine site preference and segregation properties of Cr, Ti and Y in the GB and bulk, we calculate the formation energies and segregation energies for different interstitial and substitutional sites. Cr/Ti/Y atom prefers to segregate to the substitutional sites of the GB from bulk environment, whereas Cr segregation to GB is very weak. Based on the Rice and Wang's model, Cr acts as the GB cohesion, while Ti and Y are strong embrittlers. The analysis of atomic and electronic structures provides a reasonable expansion for the embrittlement behavior. Moreover, the effect of Cr, Ti and Y in the GB on solution of interstitial impurities C, N, O, H, and He are determined. The results show that Cr restrains solution of these impurities in the GB, while Ti tends to form Ti–N complex by absorbing N impurities and Y can absorbs O and He impurities. The present calculations are helpful for understanding the behavior of alloying Cr, Ti, Y additions at the grain boundary of vanadium.

  14. HELIOS-CR - A 1-D radiation-magnetohydrodynamics code with inline atomic kinetics modeling

    International Nuclear Information System (INIS)

    MacFarlane, J.J.; Golovkin, I.E.; Woodruff, P.R.

    2006-01-01

    HELIOS-CR is a user-oriented 1D radiation-magnetohydrodynamics code to simulate the dynamic evolution of laser-produced plasmas and z-pinch plasmas. It includes an in-line collisional-radiative (CR) model for computing non-LTE atomic level populations at each time step of the hydrodynamics simulation. HELIOS-CR has been designed for ease of use, and is well-suited for experimentalists, as well as graduate and undergraduate student researchers. The energy equations employed include models for laser energy deposition, radiation from external sources, and high-current discharges. Radiative transport can be calculated using either a multi-frequency flux-limited diffusion model, or a multi-frequency, multi-angle short characteristics model. HELIOS-CR supports the use of SESAME equation of state (EOS) tables, PROPACEOS EOS/multi-group opacity data tables, and non-LTE plasma properties computed using the inline CR modeling. Time-, space-, and frequency-dependent results from HELIOS-CR calculations are readily displayed with the HydroPLOT graphics tool. In addition, the results of HELIOS simulations can be post-processed using the SPECT3D Imaging and Spectral Analysis Suite to generate images and spectra that can be directly compared with experimental measurements. The HELIOS-CR package runs on Windows, Linux, and Mac OSX platforms, and includes online documentation. We will discuss the major features of HELIOS-CR, and present example results from simulations

  15. The CR-Marketing Strategy

    OpenAIRE

    Pricop Oliver Constantin

    2011-01-01

    The Customer Relationship- Marketing supposes the adaptation of the marketing mix from the customers’ and the market’s perspective. Thus, the 4 P (product, price, place, promotion) must become 4 D (desired by consumers, distinctive from the competition, deliverable by the company, durable over time) respectively 4C (the buyer with his requirements and desires, the cost paid by the buyer, the convenience of the acquisition, the communication with the customers. The CR-Marketing strategy compri...

  16. XRD and TEM analysis of microstructure in the welding zone of 9Cr ...

    Indian Academy of Sciences (India)

    Unknown

    XRD and TEM analysis of microstructure in the welding zone of. 9Cr–1Mo–V–Nb ... steel, which has highest Cr content in the heat-resisting. Cr–Mo ... This research provides essential ... film samples were observed under TEM and select elec-.

  17. Elastic and inelastic {alpha}-scattering cross-sections obtained with the 44 MeV fixed energy Saclay cyclotron on separated targets of {sup 24}Mg, {sup 25}Mg, {sup 26}Mg, {sup 40}Ca, {sup 46}Ti, {sup 48}Ti, {sup 50}Ti, {sup 52}Cr, {sup 54}Fe, {sup 56}Fe, {sup 58}Fe, {sup 58}Ni, {sup 60}Ni, {sup 62}Ni, {sup 64}Ni, {sup 63}Cu, {sup 65}Cu, {sup 64}Zn, {sup 112}Sn, {sup 114}Sn, {sup 116}Sn, {sup 118}Sn, {sup 120}Sn, {sup 122}Sn, {sup 124}Sn and {sup 208}Pb using the Saclay fixed-energy cyclotron; Sections efficaces differentielles elastiques et inelastiques obtenues par diffusion de particules {alpha} de 44 MeV sur des cibles de {sup 24}Mg, {sup 25}Mg, {sup 26}Mg, {sup 40}Ca, {sup 46}Ti, {sup 48}Ti, {sup 50}Ti, {sup 52}Cr, {sup 54}Fe, {sup 56}Fe, {sup 58}Fe, {sup 58}Ni, {sup 60}Ni, {sup 62}Ni, {sup 64}Ni, {sup 63}Cu, {sup 65}Cu, {sup 64}Zn, {sup 112}Sn, {sup 114}Sn, {sup 116}Sn, {sup 118}Sn, {sup 120}Sn, {sup 122}Sn, {sup 124}Sn et {sup 208}Pb au cyclotron a energie fixe de saclay

    Energy Technology Data Exchange (ETDEWEB)

    Bruge, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Departement de physique nucleaire, service de physique nucleaire a moyenne energie

    1967-01-01

    This report contains elastic and inelastic {alpha}-scattering cross-sections obtained with the 44 MeV fixed energy Saclay cyclotron on Mg, Ca, Ti, Cr, Fe, Ni, Co, Zn, Sn and Pb enriched targets. (author) [French] Ce rapport contient les tableaux des sections efficaces differentielles obtenues par diffusion elastique et inelastique des particules {alpha} de 44 MeV, fournies par le cyclotron a energie fixe de Saclay, sur des cibles d'isotopes separes de Mg, Ca, Ti, Cr, Fe, Ni, Co, Zn, Sn et Pb. (auteur)

  18. Response of CR-39 based personnel neutron dosemeter in terms of directional dose equivalent, in free air and on phantom

    International Nuclear Information System (INIS)

    Pal, Rupali R.; Sathian, Deepa; Jayalakshmi, V.; Chougaonkar, M.P.

    2011-01-01

    CR-39 is the most sensitive of nuclear track detectors for protons and is recommended as an effective neutron dosimeter because of it's low threshold energy of 100 keV neutrons. The fraction of protons that gives detectable tracks in CR-39 depends on the energy of the proton angle of incidence and etching conditions. As a consequence the registration efficiency of neutrons in the CR-39 plastics used for neutron personnel monitoring is strongly influenced by the direction of radiation incidence. This paper presents the relative response of CR-39 at varying neutron incident angles, for 241 Am-Be neutron source spectra in free air and on ISO phantom, in terms of operational quantities. It is observed that the angular dependence of CR-39 for irradiations in air and on phantom is essentially the same indicating that the phantom does not affect the directional response of CR-39. (author)

  19. Characterization of Cr/Bentonite and HZSM-5 Zeolite as Catalysts for Ethanol Conversion to Biogasoline

    Directory of Open Access Journals (Sweden)

    Robert Ronal Widjaya

    2012-04-01

    Full Text Available In this research it has been done characterization on Cr/Bentonit and Zeolit HZSM-5 catalysts for ethanol catalytic process to biogasoline (equal to gasoline. Cr/Bentonit has high acidity and resistant to a lot of moisture, so in addition to being able to processing feed which a lot of moisture (>15% from ethanol-water mixture, also it is not easy deactivated. Cr/Bentonit which is then used as the catalyst material on the process of ethanol conversion to be biogasoline and the result was compared with catalyst HZSM-5 zeolite. Several characterization methods: X-ray diffraction, Brunauer Emmett Teller (BET, thermogravimetry analysis (TGA, and catalyst activity tests using catalytic Muffler instrument and gas chromatography-mass spectrometry (GC-MS for product analysis were performed on both catalysts. From acidity measurement, it is known that acidity level of Cr/Bentonit is the highest and also from XRD result, it is known there is shift for 2theta in Cr/Bentonit, which indicates that Cr-pillar in the Bentonite can have interaction. It is also supported by BET data that shows the addition of specific surface are in Cr/Bentonite compared with natural Bentonite before pillarization. Futhermore catalyst activity test produced the results, analyzed by GC-MS, identified as butanol and also possibly formed hexanol, decane, dodecane, undecane, which are all included in gasoline range (C4 until C12.

  20. Effects of V and Cr on Laser Cladded Fe-Based Coatings

    Directory of Open Access Journals (Sweden)

    Haiyang Wang

    2018-03-01

    Full Text Available Fe-based coatings with high V and Cr content were obtained by laser cladding using Fe-based powder with different Cr3C2 and FeV50 content. The results showed that Fe-based coatings were uniform and dense. The constituent phases were mainly composed of α-Fe solid solution with the increase of Cr3C2 and FeV50, γ-Fe and V8C7 phases were achieved. The microstructure of the coatings exhibited a typical dendrite structure. The concentration of C, V and Cr were saturated in dendritic areas, and the other alloying elements were mainly dissolved in the interdendritic areas. The hardness and wear resistance of Fe-based coatings were enhanced with the Cr3C2 and FeV50 addition. The specimen with 15% Cr3C2 and 16% FeV50 had the highest hardness of 66.1 ± 0.6 HRC, which was 1.05 times higher than the sample with 4.5% Cr3C2 and 5% FeV50, and the wear resistance of the former was three times greater than the latter.

  1. Effect of CrO3 Sealing Time on Anodized A12024-T3

    Science.gov (United States)

    Korda, Akhmad A.; Hidayat, R. Z.

    2016-08-01

    The effect of CrO3 sealing time on anodized aluminum alloy has been investigated. A1 2024-T3 were used as substrate. Anodizing was carried out using chromic acid. CrO3 sealing was conducted in CrO3 solution for 30, 60, 90, 120 and 150 minutes. As comparison, other specimens were also prepared as anodized and boiled water sealing. Thickness of the coating was observed by optical microscope. Anodized and sealing layer was analyzed by X- ray diffraction. The hardness of as anodized, boiled water sealing and CrO3 sealing were compared. The highest hardness is achieved by CrO3 sealed specimen and followed by boiled water sealing and as anodized specimens. The longer the processes of CrO3 sealing the higher layer thickness and therefore the higher hardness of the oxide layer. The best resistance to electrolyte penetration is achieved by the CrO3 sealed specimen followed by boiled water sealed and as anodized specimens. The higher thickness of oxide layer, the higher the resistance against electrolyte penetration.

  2. Effect of CrO_3 Sealing Time on Anodized A12024-T3

    International Nuclear Information System (INIS)

    Korda, Akhmad A; Hidayat, R Z

    2016-01-01

    The effect of CrO_3 sealing time on anodized aluminum alloy has been investigated. A1 2024-T3 were used as substrate. Anodizing was carried out using chromic acid. CrO_3 sealing was conducted in CrO_3 solution for 30, 60, 90, 120 and 150 minutes. As comparison, other specimens were also prepared as anodized and boiled water sealing. Thickness of the coating was observed by optical microscope. Anodized and sealing layer was analyzed by X- ray diffraction. The hardness of as anodized, boiled water sealing and CrO_3 sealing were compared. The highest hardness is achieved by CrO_3 sealed specimen and followed by boiled water sealing and as anodized specimens. The longer the processes of CrO3 sealing the higher layer thickness and therefore the higher hardness of the oxide layer. The best resistance to electrolyte penetration is achieved by the CrO_3 sealed specimen followed by boiled water sealed and as anodized specimens. The higher thickness of oxide layer, the higher the resistance against electrolyte penetration. (paper)

  3. Distribution of /sup 51/Cr labelled endotoxin on tissue and intracellular organella in mice

    Energy Technology Data Exchange (ETDEWEB)

    Saito, K; Suzuki, M; Okuaki, A; Saito, M [Fukushima Medical Coll. (Japan)

    1976-10-01

    The distribution of /sup 51/Cr labelled endotoxin was investigated in mice. The degree of toxicity between non-labelled endotoxin and /sup 51/Cr labelled endotoxin did not change. /sup 51/Cr-endotoxin was distributed in the highest levels in the liver, and to a lesser degree in the intestine, lungs, spleen and kidneys. The affinity of the tissue to /sup 51/Cr-endotoxin was strongest in the liver followed by the spleen, lungs, kidneys and intestine. /sup 51/Cr-endotoxin was distributed mainly in the mitochondrial fraction and the nuclear fraction in the intracellular species. /sup 51/Cr-endotoxin was distributed only in the liver and the intestine when a small dose was administered. It was also distributed in the lungs, spleen and kidneys when a large dose was given, but the uptake in the liver was somewhat limited. /sup 51/Cr-endotoxin was distributed mainly in the liver and the spleen in the mice that survived one week.

  4. Ten years of CR physics with PAMELA

    Science.gov (United States)

    Galper, A.; Spillantini, P.

    2017-09-01

    The satellite borne Pamela instrument is dedicated to the precise and high statistics study of CR fluxes on a four decades energy range. Pamela experiment is the last step of the "Russian-Italian Mission" (RIM) program established in 1992 between several Italian and Russian institutes and with the participation of Sweden and Germany. Designed as a cosmic ray observatory at 1 AU, it extensive program is made possible thanks to the outstanding performance of the instrument, the low energy threshold, the quasi-polar orbit and the 10 years duration of the observation. The physics program pays particular attention to the study of particles and antiparticles fluxes and includes search for dark matter, primordial antimatter, new matter in the Universe, study of cosmic-ray propagation, solar physics and solar modulation, and terrestrial magnetosphere. Very important is the discovery of the anomalous increase of the positron flux at energies higher that 50 GeV (the so called "Pamela anomaly"), and the abrupt spectral hardening of H and He, challenging the current paradigm of cosmic-ray acceleration and propagation in the Galaxy.

  5. Colour due to Cr3+ ions in oxides: a study of the model system MgO:Cr3+

    International Nuclear Information System (INIS)

    Aramburu, J A; García-Fernández, P; Moreno, M; García-Lastra, J M; Barriuso, M T

    2013-01-01

    Seeking to understand why the cubic centre in MgO:Cr 3+ has the same 10Dq value as emerald, ab initio cluster and periodic supercell calculations have been performed. It is found that the equilibrium Cr 3+ –O 2− distance, R, in MgO:Cr 3+ is equal to 2.03 Å and thus 0.06 Å higher than that measured for the emerald. Calculations carried out on the isolated CrO 6 9- complex at R = 2.03 Å give 10Dq = 14 510 cm −1 , which is 10% smaller than the experimental figure for MgO:Cr 3+ . Nevertheless, when the internal electric field, E R (r), due to the rest of the lattice ions is also taken into account, the calculated 10Dq = 16 210 cm −1 coincides with the experimental value. Accordingly, the colour shift for different oxides doped with Cr 3+ can be well understood on the basis of this extrinsic contribution to 10Dq usually ignored in a ligand field description. The calculated electrostatic potential, V R (r), related to E R (r), is found to be attractive when the electronic density is lying along 〈110〉 directions and |r| > 1 Å driven by the first shell of twelve Mg 2+ ions. The action of V R (r) upon the CrO 6 9- complex slightly decreases the energy of t 2g (xy,xz,yz) orbitals with respect to that for e g (3z 2 − r 2 ,x 2 − y 2 ) orbitals, thus enhancing the 10Dq value by 0.2 eV. However, the addition of V R (r) induces very small changes in the electronic density, a relevant fact that is related to the 2 E( 2g 3 ) → 4 A 2 (t 2g 3 ) emission energy being nearly independent of the host lattice along the series of Cr 3+ -doped oxides. (paper)

  6. Biliary excretion and distribution of 51Cr(III) and 51Cr(VI) in rats

    International Nuclear Information System (INIS)

    Cikrt, M.; Bencko, V.

    1979-01-01

    The biliary excretion and distribution of 51 Cr after intravenous administration of 51 Cr(III) ( 51 CrCl 3 ) or 51 Cr(VI) (Na 2 51 CrO 4 .4H 2 O) were studied in rats. The cumulative biliary excretion of 51 Cr 24 hrs after the injection was significantly higher after administration of 51 Cr(VI) than of 51 Cr(III) (3.51+-0.7% and 0.51+-0.05% of administered dose, respectively). This difference was especially due to a higher rate of biliary excretion of 51 Cr in the first hours after 51 Cr(VI) administration. The excretion of 51 Cr via feces was also higher after administration of 51 Cr(VI) (7.35+-0.45%) of administered dose, as against 4.23+-0.23% after 51 Cr(III). On the other hand, no significant difference in urinary excretion of 51 Cr was found. Statistically significant differences were also observed in the distribution of 51 Cr in the organism after administration of both valence states of the metal. (author)

  7. A Comparative Physics Study of Commercial PWR Cores using Metallic Micro-cell UO{sub 2}-Cr (or Mo) Pellets with Cr-based Cladding Coating

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Dae Hee; Hong, Ser Gi [Kyung Hee University, Yongin (Korea, Republic of); In, Wang Kee [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    In this work, a comparative neutronic analysis of the cores using ATFs which include metallic micro-cell UO{sub 2}-Cr, UO{sub 2}-Mo pellets and Cr-based alloy coating on cladding was performed to show the effects of the ATF fuels on the core performance. In this study, the cores having different ATFs use the same initial uranium enrichments. The ATF concepts studied in this work are the metallic microcell UO{sub 2} pellets containing Cr or Mo with cladding outer coating composed of Cr-based alloy which have been suggested as the ATF concepts in KAERI (Korea Atomic Energy Research Institute). The metallic micro-cell pellets and Cr-based alloy coating can enhance thermal conductivity of fuel and reduce the production of hydrogen from the reaction of cladding with coolant, respectively. The objective of this work is to compare neutronic characteristics of commercial PWR equilibrium cores utilizing the different variations of metallic micro-cell UO{sub 2} pellets with cladding coating composed of Cr-based alloy. The results showed that the cores using UO{sub 2}-Cr and UO{sub 2}-Mo pellets with Cr-based alloy coating on cladding have reduced cycle lengths by 60 and 106 EFPDs, respectively, in comparison with the reference UO{sub 2} fueled core due to the reduced heavy metal inventories and large thermal absorption cross section but they do not have any significant differences in the core performances parameters. However, it is notable that the core fueled the micro-cell UO{sub 2}-Mo pellet and Cr-based alloy coating has considerably more negative MTC and slightly more negative FTC than the other cases. These characteristics of the core using micro-cell UO{sub 2}-Mo pellet and Cr-based alloy coating is due to the hard neutron spectrum and large capture resonance cross section of Mo isotopes.

  8. Microbial Precipitation of Cr(III)-Hydroxide and Se(0) Nanoparticles During Anoxic Bioreduction of Cr(VI)- and Se(VI)-Contaminated Water.

    Science.gov (United States)

    Kim, Yumi; Oh, Jong-Min; Roh, Yul

    2017-04-01

    This study examined the microbial precipitations of Cr(III)-hydroxide and Se(0) nanoparticles during anoxic bioreductions of Cr(VI) and Se(VI) using metal-reducing bacteria enriched from groundwater. Metal-reducing bacteria enriched from groundwater at the Korea Atomic Energy Research Institute (KAERI) Underground Research Tunnel (KURT), Daejeon, S. Korea were used. Metal reduction and precipitation experiments with the metal-reducing bacteria were conducted using Cr(VI)- and Se(VI)-contaminated water and glucose as a carbon source under an anaerobic environment at room temperature. XRD, SEM-EDX, and TEM-EDX analyses were used to characterize the mineralogy, crystal structure, chemistry, shape, and size distribution of the precipitates. The metal-reducing bacteria reduced Cr(VI) of potassium chromate (K₂CrO₄) to Cr(III) of chromium hydroxide [Cr(OH)3], and Se(VI) of sodium selenate (Na₂SeO₄) to selenium Se(0), with changes of color and turbidity. XRD, SEM-EDX, and TEM-EDX analyses revealed that the chromium hydroxide [Cr(OH)₃] was formed extracellularly with nanoparticles of 20–30 nm in size, and elemental selenium Se(0) nanoparticles had a sphere shape of 50–250 nm in size. These results show that metal-reducing bacteria in groundwater can aid or accelerate precipitation of heavy metals such as Cr(VI) and Se(VI) via bioreduction processes under anoxic environments. These results may also be useful for the recovery of Cr and Se nanoparticles in natural environments.

  9. Effect of d electrons on defect properties in equiatomic NiCoCr and NiCoFeCr concentrated solid solution alloys

    Science.gov (United States)

    Zhao, Shijun; Egami, Takeshi; Stocks, G. Malcolm; Zhang, Yanwen

    2018-01-01

    The role of d electrons in determining distributions of formation and migration energies for point defects in equiatomic NiCoCr and NiCoFeCr concentrated solid solution alloys (CSAs) are studied regarding electron density deformation flexibility based on first-principles calculations. The disordered state is taken into account by constructing special quasirandom structures. The migration barriers are determined by directly optimizing the saddle point. It is found that the formation energies of interstitials in CSAs are lower than those in pure Ni, whereas the formation energies of vacancies are higher. In both NiCoCr and NiCoFeCr, Co-related dumbbell interstitials exhibit lower formation energies. Notably, the distributions of migration energies for Cr interstitials and vacancies exhibit a remarkable overlap region. A detailed analysis of electronic properties reveals that the electronic charge deformation flexibility regarding eg to t2g transition has a dominant effect on defect energetics for different elements in CSAs. Thus the electron deformation ability is suggested as a key factor in understanding the peculiar defect behavior in CSAs.

  10. Applications of CR-39 solid state nuclear track detector to ion beam diagnosis

    International Nuclear Information System (INIS)

    Kanasaki, Masato; Hattori, Atsuto; Oda, Keiji; Yamauchi, Tomoya; Fukuda, Yuji; Sakaki, Hironao; Nishiuchi, Mamiko; Kondo, Kiminori; Kurashima, Satoshi; Kamiya, Tomihiro

    2012-01-01

    CR-39 solid state nuclear track detector, which was developed for optical lens, has been applied for various field such as radon surveys, measurement of galactic cosmic ray, cell irradiation experiment and so on. The CR-39 detectors have the great advantages of being insensitive to high energy photons and electrons and capable of detecting only ions in the mixed fields such as laser driven relativistic plasmas. Though there are some analytical methods of CR-39 to diagnose ion beam, unfortunately, only few researchers in the field of plasma know the methods. This article looks at how to use CR-39 detectors and introduce the accomplishment of the joint study JAEA and Kobe Univ. for application of CR-39 detectors to ion beam diagnosis. (author)

  11. An electrochemical study of U(VI) and Cr(VI) in molten borates

    International Nuclear Information System (INIS)

    Brigaudeau, M.; Gregori de Pinochet, I. de

    1977-01-01

    The electrochemical reduction of U(VI) and Cr(VI), in molten Na 2 B 4 O 7 at 800 deg C was studied by means of linear sweep voltammetry, and chronopotentiometry. The reduction of U(VI) to U(V) proceeded reversibly at a platinum electrode. The diffusion coefficient for the U(VI) species at 800 deg C was 4.10 -7 cm 2 .s -1 . The activation energy of diffusion was (34,8 +- 0,8) kcal. mole -1 . Electrochemical studies of Cr(VI) at 800 0 C reveal a two-step reduction process at a platinum electrode. Only the voltammogram for the first step charge transfer process was studied. Analysis indicated that Cr(VI) is reversibly reduced to Cr(III) at a platinum electrode. The diffusion coefficient for Cr(VI) at 800 0 C is 1,9.10 -7 cm 2 .s -1 [fr

  12. Cr(Vi) reduction capacity of activated sludge as affected by nitrogen and carbon sources, microbial acclimation and cell multiplication

    International Nuclear Information System (INIS)

    Ferro Orozco, A.M.; Contreras, E.M.; Zaritzky, N.E.

    2010-01-01

    The objectives of the present work were: (i) to analyze the capacity of activated sludge to reduce hexavalent chromium using different carbon sources as electron donors in batch reactors, (ii) to determine the relationship between biomass growth and the amount of Cr(VI) reduced considering the effect of the nitrogen to carbon source ratio, and (iii) to determine the effect of the Cr(VI) acclimation stage on the performance of the biological chromium reduction assessing the stability of the Cr(VI) reduction capacity of the activated sludge. The highest specific Cr(VI) removal rate (q Cr ) was attained with cheese whey or lactose as electron donors decreasing in the following order: cheese whey ∼ lactose > glucose > citrate > acetate. Batch assays with different nitrogen to carbon source ratio demonstrated that biological Cr(VI) reduction is associated to the cell multiplication phase; as a result, maximum Cr(VI) removal rates occur when there is no substrate limitation. The biomass can be acclimated to the presence of Cr(VI) and generate new cells that maintain the ability to reduce chromate. Therefore, the activated sludge process could be applied to a continuous Cr(VI) removal process.

  13. Tissue distribution, subcellular localization and endocrine disruption patterns induced by Cr and Mn in the crab Ucides cordatus

    International Nuclear Information System (INIS)

    Correa, Jose Dias; Ramos da Silva, Miguel; Bastos da Silva, Antonio Carlos; Araujo de Lima, Silene Maria; Malm, Olaf; Allodi, Silvana

    2005-01-01

    The essential trace elements Cr and Mn are toxic at high concentrations and information about low concentration is insufficient in the literature. In polluted mangroves, the crab Ucides cordatus can represent a useful tool to assess information on the potential impact of trace elements like Cr and Mn on the environment, since this species is comestible and thus, commercially negotiated. Therefore, U. cordatus crabs were exposed in vivo to different concentrations of Cr and Mn solved in seawater and had their tissue distribution and subcellular deposits evaluated. The gill, hepatopancreas and muscle concentrations were determined by atomic absorption spectroscopy and the results showed that Cr and Mn presented the highest values in the gills rather than in the hepatopancreas and muscular tissue. Electron microscopy and analytical X-ray microanalysis revealed Cr precipitates on the gill surface, co-localized with epiphyte bacteria. In addition, since Cr and Mn did not equally accumulate in most of the tissues studied, glycemic rate of animals, which received injections of extracts of eyestalks of the contaminated crabs, were measured in order to evaluate whether the studied concentrations of Cr and Mn could produce any metabolic alteration. The results indicated that extracts of the eyestalks of crabs submitted to Cr and Mn salts and injected into normal crabs markedly influenced crustacean hyperglycemic hormone synthesis and/or release. The results are discussed with respect to sensitivity of the employed methods and the possible significance of the concentrations of Cr and Mn in the organisms

  14. Bulk and surface properties of liquid Al-Cr and Cr-Ni alloys

    International Nuclear Information System (INIS)

    Novakovic, R

    2011-01-01

    The energetics of mixing and structural arrangement in liquid Al-Cr and Cr-Ni alloys has been analysed through the study of surface properties (surface tension and surface segregation), dynamic properties (chemical diffusion) and microscopic functions (concentration fluctuations in the long-wavelength limit and chemical short-range order parameter) in the framework of statistical mechanical theory in conjunction with quasi-lattice theory. The Al-Cr phase diagram exhibits the existence of different intermetallic compounds in the solid state, while that of Cr-Ni is a simple eutectic-type phase diagram at high temperatures and includes the low-temperature peritectoid reaction in the range near a CrNi 2 composition. Accordingly, the mixing behaviour in Al-Cr and Cr-Ni alloy melts was studied using the complex formation model in the weak interaction approximation and by postulating Al 8 Cr 5 and CrNi 2 chemical complexes, respectively, as energetically favoured.

  15. Bulk and surface properties of liquid Al-Cr and Cr-Ni alloys.

    Science.gov (United States)

    Novakovic, R

    2011-06-15

    The energetics of mixing and structural arrangement in liquid Al-Cr and Cr-Ni alloys has been analysed through the study of surface properties (surface tension and surface segregation), dynamic properties (chemical diffusion) and microscopic functions (concentration fluctuations in the long-wavelength limit and chemical short-range order parameter) in the framework of statistical mechanical theory in conjunction with quasi-lattice theory. The Al-Cr phase diagram exhibits the existence of different intermetallic compounds in the solid state, while that of Cr-Ni is a simple eutectic-type phase diagram at high temperatures and includes the low-temperature peritectoid reaction in the range near a CrNi(2) composition. Accordingly, the mixing behaviour in Al-Cr and Cr-Ni alloy melts was studied using the complex formation model in the weak interaction approximation and by postulating Al(8)Cr(5) and CrNi(2) chemical complexes, respectively, as energetically favoured.

  16. On registration properties of Intercast Company CR-39

    International Nuclear Information System (INIS)

    Golovchenko, A.N.

    1991-01-01

    The CR-39 response function has been determined by using the accelerated particles of intermediate ( 2 H, 4 He, 12 C, 16 O, 20 Ne and 40 Ar) and relativistic ( 19 F) energies. The irradiated detectors were etched in 6N NaOH kept at 70 deg C. The response function is determined in a wide range of the ionization change. 10 refs.; 1 fig.; 2 tabs

  17. Highest weight generating functions for hyperKähler T{sup ⋆}(G/H) spaces

    Energy Technology Data Exchange (ETDEWEB)

    Hanany, Amihay [Theoretical Physics Group, Imperial College London,Prince Consort Road, London, SW7 2AZ (United Kingdom); Ramgoolam, Sanjaye [Centre for Research in String Theory,School of Physics and Astronomy, Queen Mary University of London,Mile End Road, London E1 4NS (United Kingdom); Rodriguez-Gomez, Diego [Department of Physics, Universidad de Oviedo,Avda. Calvo Sotelo 18, 33007, Oviedo (Spain)

    2016-10-05

    We develop an efficient procedure for counting holomorphic functions on a hyperKahler cone that has a resolution as a cotangent bundle of a homogeneous space by providing a formula for computing the corresponding Highest Weight Generating function.

  18. Influence of sports games classes in specialized sections on formation of healthy lifestyle at students of the highest educational institutions

    OpenAIRE

    Kudryavtsev, M.; Galimova, A.; Alshuvayli, Kh.; Altuvayni, A.

    2018-01-01

    In modern society, the problem of formation of healthy lifestyle at youth, in particular, at students of the highest educational institutions is very relevant. Sport is a good mean for motivation, in this case – sports games. Purpose: to reveal consequences of participation in sports games and influence of these actions on healthy lifestyle of students of the highest educational institutions, to designate a role of classes in the sections, specializing in preparation for sports games in this ...

  19. Revealing the Microstructural evolution in Cu-Cr nanocrystalline alloys during high pressure torsion

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jinming; Rosalie, Julian M.; Pippan, Reinhard; Zhang, Zaoli, E-mail: zaoli.zhang@oeaw.ac.at

    2017-05-17

    Usually immiscible Cu-Cr compounds in equilibrium condition were mechanically processed via high pressure torsion with large and controlled strains. A systematical investigation on 57 wt%Cu − 43 wt%Cr was carried out to get insights into the microstructural evolution of Cu-Cr nanocomposites and their dissolution process, as well as to determine the solid solubility limit of Cu and Cr elements under severe deformation. Microstructural evolution was captured with grain refinement from micron-size down to less than 20 nm as the increase of strains. A strain-saturated state in 57 wt%Cu − 43 wt%Cr bulk was achieved after 100 rotations deformation (effective strain 1360), with a stable grain size of 13.7 nm and invariable hardness of 480–495 HV. Fine scanning of X-ray diffraction and sub-nanometer scale measurements of energy-dispersive X-ray spectroscopy showed that 32 wt% Cu could be fully dissolved into Cr matrix, and conversely solubility of Cr in Cu was determined to be about 3 wt% after an enough amount of deformation. The phase fraction change associated with Cu dissolution into Cr matrix during continuous deformation was captured and accurately calculated, indicating a negative exponential phase change mode. A phenomenological intermixing mechanism based on the kinetic competition between external forcing mixing and thermal-diffusion induced decomposition was proposed, which was well accordant with the phase evolution observed from experimental results.

  20. Isolation and characterization of a chromium-resistant bacterium Serratia sp. Cr-10 from a chromate-contaminated site.

    Science.gov (United States)

    Zhang, Kundi; Li, Fuli

    2011-05-01

    A novel bacterium, Cr-10, was isolated from a chromium-contaminated site and capable of removing toxic chromium species from solution by reducing hexavalent chromium to an insoluble precipitate. Sequence analysis of 16S rRNA gene of strain Cr-10 showed that it was most closely related to Serratia rubidaea JCM 1240(T) (97.68%). Physiological and chemotaxonomic data also supported that strain Cr-10 was identified as Serratia sp., a genus which was never specially reported chromate-resistant before. Serratia sp., Cr-10 was tolerant to a concentration of 1,500 mg Cr(VI) L(-1), which was the highest level reported until now. The optimum pH and temperature for reduction of Cr(VI) by Serratia sp. Cr-10 were found to be 7.0 and 37 °C, respectively. The Cr(VI) reduction was significantly influenced by additional carbon sources, and among them fructose and lactose offered maximum reduction, with a rate of 0.28 and 0.25 mg Cr(VI) L(-1) h(-1), respectively. The cell-free extracts and filtrate of the culture were able to reduce Cr(VI) while concentration of total chromium remained stable in the process, indicating that the enzyme-catalyzed mechanism was applied in Cr(VI) reduction by the isolate. Additionally, it was found that there was hardly any chromium on the cell surface of the strain, further supporting that reduction, rather than bioadsorption, plays a major role in the Cr(VI) removal.

  1. Isolation and characterization of a chromium-resistant bacterium Serratia sp. Cr-10 from a chromate-contaminated site

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Kundi; Li, Fuli [Chinese Academy of Sciences, Qingdao (China). Qingdao Inst. of Bioenergy and Bioprocess Technology

    2011-05-15

    A novel bacterium, Cr-10, was isolated from a chromium-contaminated site and capable of removing toxic chromium species from solution by reducing hexavalent chromium to an insoluble precipitate. Sequence analysis of 16S rRNA gene of strain Cr-10 showed that it was most closely related to Serratia rubidaea JCM 1240{sup T} (97.68%). Physiological and chemotaxonomic data also supported that strain Cr-10 was identified as Serratia sp., a genus which was never specially reported chromate-resistant before. Serratia sp., Cr-10 was tolerant to a concentration of 1,500 mg Cr(VI) L{sup -1}, which was the highest level reported until now. The optimum pH and temperature for reduction of Cr(VI) by Serratia sp. Cr-10 were found to be 7.0 and 37 C, respectively. The Cr(VI) reduction was significantly influenced by additional carbon sources, and among them fructose and lactose offered maximum reduction, with a rate of 0.28 and 0.25 mg Cr(VI) L{sup -1} h{sup -1}, respectively. The cell-free extracts and filtrate of the culture were able to reduce Cr(VI) while concentration of total chromium remained stable in the process, indicating that the enzyme-catalyzed mechanism was applied in Cr(VI) reduction by the isolate. Additionally, it was found that there was hardly any chromium on the cell surface of the strain, further supporting that reduction, rather than bioadsorption, plays a major role in the Cr(VI) removal. (orig.)

  2. Oxidation resistance of TiN, CrN, TiAlN and CrAlN coatings deposited by lateral rotating cathode arc

    International Nuclear Information System (INIS)

    Chim, Y.C.; Ding, X.Z.; Zeng, X.T.; Zhang, S.

    2009-01-01

    In this paper, four kinds of hard coatings, TiN, CrN, TiAlN and CrAlN (with Al/Ti or Al/Cr atomic ratio around 1:1), were deposited on stainless steel substrates by a lateral rotating cathode arc technique. The as-deposited coatings were annealed in ambient atmosphere at different temperatures (500-1000 o C) for 1 h. The evolution of chemical composition, microstructure, and microhardness of these coatings after annealing at different temperatures was systematically analyzed by energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and nanoindentation experiments. The oxidation behaviour and its influence on overall hardness of these four coatings were compared. It was found that the ternary TiAlN and CrAlN coatings have better oxidation resistance than their binary counterparts, TiN and CrN coatings. The Cr-based coatings (CrN and CrAlN) exhibited evidently better oxidation resistance than the Ti-based coatings (TiN and TiAlN). TiN coating started to oxidize at 500 o C. After annealing at 700 o C no N could be detected by EDX, indicating that the coating was almost fully oxidized. After annealed at 800 o C, the coating completely delaminated from the substrate. TiAlN started to oxidize at 600 o C. It was nearly fully oxidized (with little residual nitrogen detected in the coating by EDX) and partially delaminated at 1000 o C. Both CrN and CrAlN started to oxidize at 700 o C. CrN was almost fully oxidized (with little residual nitrogen detected in the coating by EDX) and partially delaminated at 900 o C. The oxidation rate of the CrAlN coating is quite slow. After annealing at 1000 o C, only about 19 at.% oxygen was detected and the coating showed no delamination. The Ti-based (TiN and TiAlN) coatings were not able to retain their hardness at higher temperatures (≥ 700 o C). On the other hand, the hardness of CrAlN was stable at a high level between 33 and 35 GPa up to an annealing temperature of 800 o C and still kept at a comparative high value of

  3. Density functional theory study of bulk and single-layer magnetic semiconductor CrPS4

    Science.gov (United States)

    Zhuang, Houlong L.; Zhou, Jia

    2016-11-01

    Searching for two-dimensional (2D) materials with multifunctionality is one of the main goals of current research in 2D materials. Magnetism and semiconducting are certainly two desirable functional properties for a single 2D material. In line with this goal, here we report a density functional theory (DFT) study of bulk and single-layer magnetic semiconductor CrPS4. We find that the ground-state magnetic structure of bulk CrPS4 exhibits the A-type antiferromagnetic ordering, which transforms to ferromagnetic (FM) ordering in single-layer CrPS4. The calculated formation energy and phonon spectrum confirm the stability of single-layer CrPS4. The band gaps of FM single-layer CrPS4 calculated with a hybrid density functional are within the visible-light range. We also study the effects of FM ordering on the optical absorption spectra and band alignments for water splitting, indicating that single-layer CrPS4 could be a potential photocatalyst. Our work opens up ample opportunities of energy-related applications of single-layer CrPS4.

  4. Development of neutron dosimeter using CR-39 for measurement of ambient dose equivalent

    International Nuclear Information System (INIS)

    Maki, Daisuke; Shinozaki, Wakako; Ohguchi, Hiroyuki; Yamamoto, Takayoshi; Nakamura, Takayoshi

    2010-01-01

    A CR-39 has good advantages such as cumulative type dosimeter, small fading effect and gamma-ray insensitive. Therefore, we developed the wide energy-range environmental neutron dosimeter using eight CR-39s for area monitoring in this study. This dosimeter is made of octagonal columnar polyethylene block which height is 60 mm and bottom side is 25 mm. The dosimeter contains two types of CR-39s for fast neutron detection and slow neutron detection. Four CR-39s for fast neutron detection are used for detection of recoil protons produced by H (n, p) reactions. Four CR-39s for slow neutron detection are used with boron nitride converter to detect alpha-rays produced by 10 B (n, α) 7 Li reactions. Ambient dose equivalent is obtained by adding the number of etch-pits observed in four CR-39s for fast neutron detection to the number of etch-pits observed in four CR-39s for slow neutron detection with appropriate constants respectively. Dosimeters were irradiated with some energetic neutrons and evaluated results of ambient dose equivalent were compared with results from neutron transport calculations. Energy response of dosimeter shows good agreement with neutron fluence to ambient dose equivalent conversion coefficients. Directional dependence of dosimeter is at the same level as the rem-counter. (author)

  5. Precipitation Kinetics of Cr2N in High Nitrogen Austenitic Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    SHI Feng; WANG Li-jun; CUI Wen-fang; LIU Chun-ming

    2008-01-01

    The precipitation behavior of Cr2N during isothermal aging in the temperature range from 700℃to 950℃ in Fe-18Cr-12Mn-0.48N(in mass percent)high nitrogen austenitic stainless steel,including morphology and content of precipitate,was investigated using optical microscopy,scanning electron microscopy,and transmission electron microscopy.The isothermal precipitation kinetics curve of Cr2N and the corresponding precipitation activation energy were obtained.The results show that Cr2N phase precipitates in a cellular way and its morphology is transformed from initial granular precipitates to lamellar ones in the cell with increasing aging time.The nose temperature of Cr2N precipitation is about 800℃,with a corresponding incubation period of 30 min,and the ceiling temperature of Cr2N precipitation is 950℃.The diffusion activation energy of Cr2N precipitation is 296 kJ/mol.

  6. Energy and crisis

    International Nuclear Information System (INIS)

    Rosa, L.P.

    1984-01-01

    Several aspects of the Brazilian energy policy are dealt with, regarding petroleum, electric energy and the nuclear question. Regional and international aspects relating to the energy crisis are discussed, and some alternatives for this crisis are suggested. (I. de C.R.) [pt

  7. Adsorption studies on fruits of Gular (Ficus glomerata): Removal of Cr(VI) from synthetic wastewater

    International Nuclear Information System (INIS)

    Rao, Rifaqat A.K.; Rehman, Fouzia

    2010-01-01

    The adsorption of Cr(VI) was studied in batch system using fruits of Ficus glomerata as adsorbent. The effect of temperature, pH, initial Cr(VI) concentration and time was investigated. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) was used to investigate surface morphology and active functional groups present on the adsorbent surface. Thermodynamic parameters like free energy change (ΔG 0 ), enthalpy (ΔH 0 ) and entropy (ΔS 0 ) indicate the spontaneous, endothermic and increased randomness nature of Cr(VI) adsorption. Equilibrium data were fitted well with Langmuir isotherm at 50 deg. C. The magnitude of mean free energy indicates chemical nature of adsorption. The breakthrough and exhaustive capacities were found to be 5 and 23.1 mg g -1 respectively. The applicability of the adsorbent has been demonstrated by removing Cr(VI) from electroplating wastewater.

  8. Optical properties of single doped Cr3+ and co-doped Cr3+-Nd3+ aluminum tantalum tellurite glasses

    International Nuclear Information System (INIS)

    Rodriguez-Mendoza, U.R.; Speghini, A.; Jaque, D.; Zambelli, M.; Bettinelli, M.

    2004-01-01

    The optical properties for single doped Cr 3+ and co-doped Cr 3+ -Nd 3+ aluminum tantalum tellurite glasses have been studied as a function of temperature. For the single doped glass, the existence of two bands in the emission spectra at low temperature indicates the presence of two different sites for the Cr 3+ ions, labelled as usual as low- and high-field sites. The broad band centred in the Near Infrared region, corresponds to low-field sites transition 4 T 2 → 4 A 2 , and the narrow band centred at approximately 715 nm to the high-field sites transition 2 E→ 4 A 2 . The emission intensity for both high- and low-field sites shows a strong decrease with increasing temperature, with the emission for the former sites vanishing at RT. In both cases the quenching observed with the increase of temperature can be ascribed to the presence of non-radiative relaxation mechanisms. Experimental observations for the co-doped glass show that both radiative and non-radiative energy transfer processes from Cr 3+ to Nd 3+ are present

  9. Theoretical calculation of zero field splitting parameters of Cr{sup 3+} doped ammonium oxalate monohydrate

    Energy Technology Data Exchange (ETDEWEB)

    Kripal, Ram, E-mail: ram_kripal2001@rediffmail.com; Yadav, Awadhesh Kumar, E-mail: aky.physics@gmail.com

    2015-06-15

    Zero field splitting parameters (ZFSPs) D and E of Cr{sup 3+} ion doped ammonium oxalate monohydrate (AOM) are calculated with formula using the superposition model. The theoretically calculated ZFSPs for Cr{sup 3+} in AOM crystal are compared with the experimental value obtained by electron paramagnetic resonance (EPR). Theoretical ZFSPs are in good agreement with the experimental ones. The energy band positions of optical absorption spectra of Cr{sup 3+} in AOM crystal calculated with CFA package are in good match with the experimental values.

  10. Detection of light charged particles from plasma focus by CR-39

    Energy Technology Data Exchange (ETDEWEB)

    Antanasijevic, R.; Vukovic, J.; Popovic, S.; Popovic, M. (Belgrade Univ. (Yugoslavia). Inst. za Fiziku); Puric, J.; Cuk, M. (Faculty of Physical Science, Belgrade (Yugoslavia))

    1991-01-01

    An analysis of a deuteron (D{sup +}) beam, emitted from a plasma focus has been carried out, using a CR-39 plastic nuclear track detector. The CR-39 was pretreated using different processes to destroy the existing background before exposing it to the particles produced in the plasma focus. From measurements of the diameters of the tracks, the estimated energy of the D{sup +} ions is about 0.5 MeV. The total number of emitted D{sup +} ions was 10 particles/pulse. Some preliminary results on imaging etched CR-39 with an Atomic Force Microscope (NanoScope AFM) are also presented. (author).

  11. Detection of light charged particles from plasma focus by CR-39

    International Nuclear Information System (INIS)

    Antanasijevic, R.; Vukovic, J.; Popovic, S.; Popovic, M.

    1991-01-01

    An analysis of a deuteron (D + ) beam, emitted from a plasma focus has been carried out, using a CR-39 plastic nuclear track detector. The CR-39 was pretreated using different processes to destroy the existing background before exposing it to the particles produced in the plasma focus. From measurements of the diameters of the tracks, the estimated energy of the D + ions is about 0.5 MeV. The total number of emitted D + ions was 10 particles/pulse. Some preliminary results on imaging etched CR-39 with an Atomic Force Microscope (NanoScope AFM) are also presented. (author)

  12. Annealing effect on the structural and optical properties of Cr/α-Cr2O3 monodispersed particles based solar absorbers

    International Nuclear Information System (INIS)

    Khamlich, S.; McCrindle, R.; Nuru, Z.Y.; Cingo, N.; Maaza, M.

    2013-01-01

    Graphical abstract: A cost-effective and environmentally friendly green chemical method, the so-called aqueous chemical growth (ACG) method, was used to deposit chromium/alpha-chromium(III) oxide, Cr/α-Cr 2 O 3 , monodispersed particles, for solar absorbers applications. Highlights: ► Cr/α-Cr 2 O 3 have been deposited by the aqueous chemical growth (ACG) method. ► High temperature annealing affects the optical selectivity of the deposited particles. ► Oxygen diffusion to the interface at high temperature results in the oxidization of the substrate. - Abstract: A cost-effective and environmentally friendly green chemical method, the so-called aqueous chemical growth (ACG) method, was used to deposit chromium/alpha-chromium(III) oxide, Cr/α-Cr 2 O 3 , monodispersed particles, for solar absorbers applications. The deposited particles were annealed at various temperatures in a hydrogen atmosphere for 2 h to study the annealing temperature dependence of the structural, chemical and optical properties of the particles grown on tantalum substrates. The deposited Cr/α-Cr 2 O 3 was characterized by X-ray diffraction (XRD), attenuated total reflection (ATR), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and diffuse reflectance UV–vis–NIR spectroscopy. The XRD and ATR analysis indicated that by increasing annealing temperature, the particles crystallinity was improved and Ta 2 O 5 was formed around 600 °C, due to the fast oxygen diffusion from the deposited α-Cr 2 O 3 toward the tantalum substrate. The optical measurements show that samples annealed at 400 and 500 °C exhibit the targeted high absorbing optical characteristics of “Black chrome”, while those annealed below 400 °C and above 500 °C show a significant low absorptivity and high emissivity.

  13. Enhancement of mechanical and tribological properties in AISI D3 steel substrates by using a non-isostructural CrN/AlN multilayer coating

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera, G. [Thin Film Group, Universidad del Valle in Cali (Colombia); Caicedo, J.C., E-mail: jcaicedoangulo@gmail.com [Thin Film Group, Universidad del Valle in Cali (Colombia); Amaya, C. [Thin Film Group, Universidad del Valle in Cali (Colombia); Laboratory of Hard Coatings, CDT-ASTIN SENA in Cali (Colombia); Yate, L. [Department de Fisica Aplicada i Optica, Universitat de Barcelona, Catalunya (Spain); Munoz Saldana, J. [Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Queretaro (Mexico); Prieto, P. [Thin Film Group, Universidad del Valle in Cali (Colombia); Center of Excellence for Novel Materials - CENM, Calle 13 100-00 320-026, Cali (Colombia)

    2011-02-15

    Enhancement of mechanical and tribological properties on AISI D3 steel surfaces coated with CrN/AlN multilayer systems deposited in various bilayer periods ({Lambda}) via magnetron sputtering has been studied in this work exhaustively. The coatings were characterized in terms of structural, chemical, morphological, mechanical and tribological properties by X-ray diffraction (XRD), electron dispersive spectrograph, atomic force microscopy, scanning and transmission electron microscopy, nanoindentation, pin-on-disc and scratch tests. The failure mode mechanisms were observed via optical microscopy. Results from X-ray diffraction analysis revealed that the crystal structure of CrN/AlN multilayer coatings has a NaCl-type lattice structure and hexagonal structure (wurtzite-type) for CrN and AlN, respectively, i.e., made was non-isostructural multilayers. An enhancement of both hardness and elastic modulus up to 28 GPa and 280 GPa, respectively, was observed as the bilayer periods ({Lambda}) in the coatings were decreased. The sample with a bilayer period ({Lambda}) of 60 nm and bilayer number n = 50 showed the lowest friction coefficient ({approx}0.18) and the highest critical load (43 N), corresponding to 2.2 and 1.6 times better than those values for the coating deposited with n = 1, respectively. The best behavior was obtained when the bilayer period ({Lambda}) is 60 nm (n = 50), giving the highest hardness 28 GPa and elastic modulus of 280 GPa, the lowest friction coefficient ({approx}0.18) and the highest critical load of 43 N. These results indicate an enhancement of mechanical, tribological and adhesion properties, comparing to the CrN/AlN multilayer systems with 1 bilayer at 28%, 21%, 40%, and 30%, respectively. This enhancement in hardness and toughness for multilayer coatings could be attributed to the different mechanisms for layer formation with nanometric thickness such as the Hall-Petch effect and the number of interfaces that act as obstacles for the

  14. Microstructural characterization of second phases in X10CrMoVNb9-1 and 12CrMoWCuVNb steels after long steam exposure time at 550 C

    International Nuclear Information System (INIS)

    Rodak, Kinga; Hernas, Adam; Vodarek, Vlastimil

    2015-01-01

    Microstructural changes in high alloy (9-12% Cr) creep resistant martensitic X10CrMoVNb9-1 and 12CrMoW . CuVNb steels after 100 000 h of steam exposure at 550 C have been studied using scanning transmission electron microscopy. Precipitates were identified using electron diffraction patterns and energy dispersive X-ray spectroscopy analysis. After long time exposure, a significant coarsening of M 23 C 6 carbides, and intensive precipitation of the coarse Laves phase were observed. Moreover, in the 12CrMoW . CuVNb steel, a low amount of the modified Z-phase particles was detected. The microstructures of the X10Cr . MoVNb9-1 and 12CrMoWCuVNb steels after 100 000 h of exposure differ in several aspects.

  15. Microstructural characterization of second phases in X10CrMoVNb9-1 and 12CrMoWCuVNb steels after long steam exposure time at 550 C

    Energy Technology Data Exchange (ETDEWEB)

    Rodak, Kinga; Hernas, Adam [Silesian Univ. of Technology, Inst. of Materials Science, Katowice (Poland); Vodarek, Vlastimil [VSB-Technical Univ. of Ostrava (Czech Republic)

    2015-07-15

    Microstructural changes in high alloy (9-12% Cr) creep resistant martensitic X10CrMoVNb9-1 and 12CrMoW . CuVNb steels after 100 000 h of steam exposure at 550 C have been studied using scanning transmission electron microscopy. Precipitates were identified using electron diffraction patterns and energy dispersive X-ray spectroscopy analysis. After long time exposure, a significant coarsening of M{sub 23}C{sub 6} carbides, and intensive precipitation of the coarse Laves phase were observed. Moreover, in the 12CrMoW . CuVNb steel, a low amount of the modified Z-phase particles was detected. The microstructures of the X10Cr . MoVNb9-1 and 12CrMoWCuVNb steels after 100 000 h of exposure differ in several aspects.

  16. Device characteristics of antenna-coupled metal-insulator-metal diodes (rectenna) using Al2O3, TiO2, and Cr2O3 as insulator layer for energy harvesting applications

    Science.gov (United States)

    Inac, Mesut; Shafique, Atia; Ozcan, Meric; Gurbuz, Yasar

    2015-09-01

    Antenna-coupled metal-insulator-metal devices are most potent candidate for future energy harvesting devices. The reason for that they are ultra-high speed devices that can rectify the electromagnetic radiation at high frequencies. In addition to their speed, they are also small devices that can have more number of devices in unit area. In this work, it is aimed design and develop a device which can harvest and detect IR radiation.

  17. Surface half-metallicity of half-Heusler compound FeCrSe and interface half-metallicity of FeCrSe/GaP

    Energy Technology Data Exchange (ETDEWEB)

    Khalaf Al-zyadi, Jabbar M., E-mail: jabbar_alzyadi@yahoo.com [Department of Physics, College of Education for Pure Sciences, University of Basrah (Iraq); Jolan, Mudhahir H. [Department of Physics, College of Education for Pure Sciences, University of Basrah (Iraq); Yao, Kai-Lun, E-mail: klyao@mail.hust.edu.cn [School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074 (China); International Center of Materials Physics, Chinese Academy of Sciences, Shenyang 110015 (China)

    2016-04-01

    Recent studies showed that half-Heusler FeCrSe exhibits half-metallic ferromagnetism (Huang et al. [20]). In this paper, we investigate extensively the electronic, magnetic, and half-metallic properties of the half-Heusler alloy FeCrSe (111) and (001) surfaces and the interface with GaP (111) substrate by using the first-principles calculations within the density functional theory. The atomic density of states demonstrates that the half-me tallicity verified in the bulk FeCrSe is maintained at the CrSe-terminated (001) and Se-terminated (111) surfaces, but lost at both Cr- and Fe-terminated (111) surfaces and the Fe-terminated (001) surface. Alternatively, for the interface of FeCrSe/GaP (111), the bulk half-metallicity is destroyed at Se–P configuration while Se–Ga interface and subinterface show nearly 100% spin polarization. Moreover, the calculated interfacial adhesion energies exhibit that Se–Ga shape is more stable than the Se–P one. The calculated magnetic moments of Se, Ga at the Se–Ga (111) interface and P at the Se–P (111) interface increase with respect to the corresponding bulk values while the atomic magnetic moment of Se atom at the Se–P (111) interface decreases. We also notice that the magnetic moments of subinterface Fe at both Se–Ga and Se–P (111) interfaces decrease compared to the bulk values. - Highlights: • The half-metallicity verified in the bulk FeCrSe is kept at the CrSe-terminated (001) and Se-terminated (111) surfaces. • The calculated interfacial adhesion energies exhibit that Se–Ga shape is more stable than Se–P. • The magnetic moments of Se, Ga and P atoms at the interface increase. • The Se–Ga interface shows nearly 100% spin polarization.

  18. Development of Cr{sub 3}C{sub 2}-25(Ni20Cr) nanostructured coatings; Desenvolvimento de revestimentos nanostruturados de Cr{sub 3}C{sub 2}-25(Ni20Cr)

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Cecilio Alvares da

    2012-07-01

    This study is divided in two parts. The first part is about the preparation of nanostructured Cr{sub 3}C{sub 2}-25(Ni20Cr) powders by high energy milling followed by characterization of the milled and the as received powder. Analyses of some of the data obtained were done using a theoretical approach. The second part of this study is about the preparation and characterization of coatings prepared with the nanostructured as well as the as received Cr{sub 3}C{sub 2}-25(Ni20Cr) powders. The high temperature erosion-oxidation (E-O) behavior of the coatings prepared with the two types of powders has been compared based on a technological approach. The average crystallite size of the Cr{sub 3}C{sub 2}-25(Ni20Cr) powder decreased rapidly from 145 nm to 50 nm in the initial stages of milling and thereafter decreased slowly to a steady state value of around 10 nm with further increase in milling time. This steady state corresponds to the beginning of a dynamic recovery process. The maximum lattice strain ({epsilon} = 1,17%) was observed in powders milled for 16 hours, and this powders critical crystallite size was 28 nm. In contrast, the lattice parameter attained a minimum for powders milled for 16 hours. Upon reaching the critical crystallite size, the dislocation density attained a steady state regime and all plastic deformation introduced in the material there after was in the form of events occurring at the grain boundaries, due mainly to grain boundary sliding. The deformation energy stored in the crystal lattice of the Cr{sub 3}C{sub 2}-25(Ni20Cr) powders milled for different times was determined from enthalpy variation measurements. These results indicated that the maximum enthalpy variation ({delta}H = 722 mcal) also occurred for powders milled for 16 hours. In a similar manner, the maximum specific heat variation ({delta}C{sub p} = 0,278 cal/gK) occurred for powders milled for 16 hours. The following mechanical properties of Cr{sub 3}C{sub 2}-25(Ni20Cr) coatings

  19. Highest PBDE levels (max 63 ppm) yet found in biota measured in seabird eggs from San Francisco Bay

    Energy Technology Data Exchange (ETDEWEB)

    She, J.; Holden, A.; Tanner, M.; Sharp, M.; Hooper, K. [Department of Toxic Substances Control, Berkeley, CA (United States). Hazardous Materials Lab.; Adelsbach, T. [Environmental Contaminants Division, Sacramento Fish and Wildlife Office, US Fish and Wildlife Service, Sacramento, CA (United States)

    2004-09-15

    High levels of polybrominated diphenylethers (PBDEs) have been found in humans and wildlife from the San Francisco Bay Area, with levels in women among the highest in the world, and levels in piscivorous seabird eggs at the ppm level. Seabirds are useful for monitoring and assessing ecosystem health at various times and places because they occupy a high trophic level in the marine food web, are long-lived, and are generally localized near their breeding and non-breeding sites. In collaboration with the US Fish and Wildlife Services (USFWS), we are carrying out a three-year investigation of dioxin, PCB and PBDE levels in eggs from fish-eating seabirds. Year 1 (2002) PBDE measurements from 73 bird eggs were reported at Dioxin2003. Year 2 (2003) PBDE measurements from 45 samples are presented in this report. The highest PBDE level measured in eggs was 63 ppm, lipid, which is the highest PBDE level, yet reported in biota.

  20. Supported rhodium catalysts for ammonia-borane hydrolysis. Dependence of the catalytic activity on the highest occupied state of the single rhodium atoms

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Liangbing; Li, Hongliang; Zhang, Wenbo; Zhao, Xiao; Qiu, Jianxiang; Li, Aowen; Zheng, Xusheng; Zeng, Jie [Hefei National Lab. for Physical Sciences at the Microscale, Key Lab. of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, Hefei, Anhui(China); Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui (China); Hu, Zhenpeng [School of Physics, Nankai University, Tianjin (China); Si, Rui [Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences (China)

    2017-04-18

    Supported metal nanocrystals have exhibited remarkable catalytic performance in hydrogen generation reactions, which is influenced and even determined by their supports. Accordingly, it is of fundamental importance to determine the direct relationship between catalytic performance and metal-support interactions. Herein, we provide a quantitative profile for exploring metal-support interactions by considering the highest occupied state in single-atom catalysts. The catalyst studied consisted of isolated Rh atoms dispersed on the surface of VO{sub 2} nanorods. It was observed that the activation energy of ammonia-borane hydrolysis changed when the substrate underwent a phase transition. Mechanistic studies indicate that the catalytic performance depended directly on the highest occupied state of the single Rh atoms, which was determined by the band structure of the substrates. Other metal catalysts, even with non-noble metals, that exhibited significant catalytic activity towards NH{sub 3}BH{sub 3} hydrolysis were rationally designed by adjusting their highest occupied states. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Oxidation behavior of arc evaporated Al-Cr-Si-N thin films

    Energy Technology Data Exchange (ETDEWEB)

    Tritremmel, Christian; Daniel, Rostislav; Mitterer, Christian; Mayrhofer, Paul H.; Lechthaler, Markus; Polcik, Peter [Christian Doppler Laboratory for Advanced Hard Coatings, Department of Physical Metallurgy and Materials Testing, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Christian Doppler Laboratory for Application Oriented Coating Development, Department of Physical Metallurgy and Materials Testing, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); OC Oerlikon Balzers AG, Iramali 18, LI-9496 Balzers (Liechtenstein); PLANSEE Composite Materials GmbH, Siebenbuergerstrasse 23, D-86983 Lechbruck am See (Germany)

    2012-11-15

    The impact of Al and Si on the oxidation behavior of Al-Cr-(Si)-N thin films synthesized by arc evaporation of powder metallurgically prepared Al{sub x}Cr{sub 1-x} targets with x = Al/(Al + Cr) of 0.5, 0.6, and 0.7 and (Al{sub 0.5}Cr{sub 0.5}){sub 1-z}Si{sub z} targets with Si contents of z = 0.05, 0.1, and 0.2 in N{sub 2} atmosphere was studied in detail by means of differential scanning calorimetry, thermogravimetric analysis (TGA), x-ray diffraction, and Raman spectroscopy. Dynamical measurements in synthetic air (up to 1440 Degree-Sign C) revealed the highest onset temperature of pronounced oxidation for nitride coatings prepared from the Al{sub 0.4}Cr{sub 0.4}Si{sub 0.2} target. Isothermal TGA at 1100, 1200, 1250, and 1300 Degree-Sign C highlight the pronounced improvement of the oxidation resistance of Al{sub x}Cr{sub 1-x}N coatings by the addition of Si. The results show that Si promotes the formation of a dense coating morphology as well as a dense oxide scale when exposed to air.

  2. Inclusion of Highest Glasgow Coma Scale Motor Component Score in Mortality Risk Adjustment for Benchmarking of Trauma Center Performance.

    Science.gov (United States)

    Gomez, David; Byrne, James P; Alali, Aziz S; Xiong, Wei; Hoeft, Chris; Neal, Melanie; Subacius, Harris; Nathens, Avery B

    2017-12-01

    The Glasgow Coma Scale (GCS) is the most widely used measure of traumatic brain injury (TBI) severity. Currently, the arrival GCS motor component (mGCS) score is used in risk-adjustment models for external benchmarking of mortality. However, there is evidence that the highest mGCS score in the first 24 hours after injury might be a better predictor of death. Our objective was to evaluate the impact of including the highest mGCS score on the performance of risk-adjustment models and subsequent external benchmarking results. Data were derived from the Trauma Quality Improvement Program analytic dataset (January 2014 through March 2015) and were limited to the severe TBI cohort (16 years or older, isolated head injury, GCS ≤8). Risk-adjustment models were created that varied in the mGCS covariates only (initial score, highest score, or both initial and highest mGCS scores). Model performance and fit, as well as external benchmarking results, were compared. There were 6,553 patients with severe TBI across 231 trauma centers included. Initial and highest mGCS scores were different in 47% of patients (n = 3,097). Model performance and fit improved when both initial and highest mGCS scores were included, as evidenced by improved C-statistic, Akaike Information Criterion, and adjusted R-squared values. Three-quarters of centers changed their adjusted odds ratio decile, 2.6% of centers changed outlier status, and 45% of centers exhibited a ≥0.5-SD change in the odds ratio of death after including highest mGCS score in the model. This study supports the concept that additional clinical information has the potential to not only improve the performance of current risk-adjustment models, but can also have a meaningful impact on external benchmarking strategies. Highest mGCS score is a good potential candidate for inclusion in additional models. Copyright © 2017 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  3. Mechanical alloying of Cu-xCr (x = 3, 5 and 8 wt.%) alloys

    International Nuclear Information System (INIS)

    Aguilar, C.; Ordonez, S.; Guzman, D.; Rojas, P.A.

    2010-01-01

    This work studies the structural evolution of Cu-xCr (x = 3, 5 and 8 wt.%) alloys processed by mechanical alloying using X-ray diffraction profiles, scanning microscopy and microhardness analysis. X-ray diffraction analysis using the modified Williamson-Hall and Warren-Averbach methods were used to determine structural properties, such as crystallite size, stacking fault probability and energy, dislocation density, lattice parameters and crystallite size distribution of metallic powder as a function of Cr amount and milling time. Lattice defects increase the Gibbs free energy and the Gibbs free energy curves shift upward, therefore the solubility limit change.

  4. Magnetic properties of point defect interaction with impurity atoms in Fe-Cr alloys

    Science.gov (United States)

    Nguyen-Manh, D.; Lavrentiev, M. Yu.; Dudarev, S. L.

    2009-04-01

    An integrated ab initio and statistical Monte Carlo investigation has been recently carried out to model the thermodynamic and kinetic properties of Fe-Cr alloys. We found that the conventional Fe-Cr phase diagram is not adequate at low temperature region where the magnetic contribution to the free energy plays an important role in the prediction of an ordered Fe 15Cr phase and its negative enthalpy of formation. The origin of the anomalous thermodynamic and magnetic properties of Fe-Cr alloys can be understood using a tight-binding Stoner model combined with the charge neutrality condition. We investigate the environmental dependence of magnetic moment distributions for various self-interstitial atom dumbbells configurations using spin density maps found using density functional theory calculations. The mixed dumbbell Fe-Cr and Fe-Mn binding energies are found to be positive due to magnetic interactions. Finally, we discuss the relationship between the migration energy of vacancy in Fe-Cr alloys and magnetism at the saddle point configuration.

  5. Cr(III) and Cr(VI) in leather and elicitation of eczema

    DEFF Research Database (Denmark)

    Hansen, Malene Barré; Menne, Torkil; Johansen, Jeanne Duus

    2006-01-01

    The aim of the present study was to investigate the relation between the content of Cr(VI) and soluble Cr(III) in leather and the ability of the leather to elicit eczema in chromium allergic patients. An array of chromium-tanned leather samples was analysed for the content of total Cr(VI) and sol...

  6. Cr-Ni ALLOY ELECTRODEPOSITION AND COMPARISON WITH CONVENTIONAL PURE Cr COATING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    M. Moniruzzaman

    2012-12-01

    Full Text Available Cr coating is widely used as the outer surface of precision parts due to its attractive appearance and superior corrosion resistance properties. It is obtained by electrodeposition via a conventional bath with hexavalent Cr ions. This manufacturing technique has many drawbacks, such as very low efficiency and high operating temperature and it is hazardous to health. In this work, we studied a Cr-Ni alloy deposition technique and compared the alloy coating properties to those with conventional Cr coating. Sequential two-step alloy electrodeposition was also compared. We took varying concentrations of Cr, Ni and complexing agents for the electrodeposition of Cr-Ni alloy and sequential Cr-Ni alloy coating on mild steel. Operating parameters, i.e. current density and temperature, were varied to examine their effects on the coating properties. The coatings thus obtained were characterized by visual observation, corrosion test, microhardness measurement, morphology and chemical analysis. The Cr-Ni alloy coating was found to be more corrosion resistant in 5% NaCl solution and harder than the pure Cr coating obtained by conventional electrodeposition. Toxic gas was produced in a much lower extent in the alloy coating than the conventional Cr coating technique. Again, the two-step Cr-Ni alloy coating was found better in terms of corrosion resistance as well as hardness compared to the Cr-Ni alloy coating. The process was also found to be much more environmentally friendly.

  7. Sintering behaviour and mechanical properties of Cr3C2–NiCr ...

    Indian Academy of Sciences (India)

    fracture toughness. Keywords. Cermet; Cr3C2–NiCr; sintering; mechanical properties. ... et al investigated the mechanical properties of VC, Cr3C2 and NbC doped ..... Huang S G, Li L, Van der Biest O and Vleugels J 2008 J. Alloys. Compds.

  8. Experimental Monitoring of Cr(VI) Bio-reduction Using Electrochemical Geophysics

    International Nuclear Information System (INIS)

    Birsen Canan; Gary R. Olhoeft; William A. Smith

    2007-01-01

    Many Department of Energy (DOE) sites are contaminated with highly carcinogenic hexavalent chromium (Cr(VI)). In this research, we explore the feasibility of applying complex resistivity to the detection and monitoring of microbially-induced reduction of hexavalent chromium (Cr(VI)) to a less toxic form (Cr(III)). We hope to measure the change in ionic concentration that occurs during this reduction reaction. This form of reduction promises to be an attractive alternative to more expensive remedial treatment methods. The specific goal of this research is to define the minimum and maximum concentration of the chemical and biological compounds in contaminated samples for which the Cr(VI) - Cr(III) reduction processes could be detected via complex resistivity. There are three sets of experiments, each comprised of three sample columns. The first experiment compares three concentrations of Cr(VI) at the same bacterial cell concentration. The second experiment establishes background samples with, and without, Cr(VI) and bacterial cells. The third experiment examines the influence of three different bacterial cell counts on the same concentration of Cr(VI). A polarization relaxation mechanism was observed between 10 and 50 Hz. The polarization mechanism, unfortunately, was not unique to bio-chemically active samples. Spectral analysis of complex resistivity data, however, showed that the frequency where the phase minimum occurred was not constant for bio-chemically active samples throughout the experiment. A significant shifts in phase minima occurred between 10 to 20 Hz from the initiation to completion of Cr(VI) reduction. This phenomena was quantified using the Cole-Cole model and the Marquardt-Levenberg nonlinear least square minimization method. The data suggests that the relaxation time and the time constant of this relaxation are the Cole-Cole parameters most sensitive to changes in biologically-induced reduction of Cr(VI)

  9. Fatigue failure analysis of V-4Ti-4Cr alloy

    International Nuclear Information System (INIS)

    Aglan, H.; Gan, Y.X.; Grossbeck, M.

    1999-01-01

    In the present work, the fatigue fracture and failure behavior of a V-4Ti-4Cr has been studied. Static tests were conducted to study the overloading behavior and to select the magnitude of the stress level for the fatigue studies. Fatigue tests were performed using single edge notched (SEN) specimens under tension-tension load control conditions. Fatigue crack propagation (FCP) data such as the crack length, number of cycles, and hysteresis loops were recorded to calculate the crack speed, the energy release rate, and the change in work expended on damage formation and dissipative processes within the material. Parameters characterizing the fatigue fracture resistance of V-4Ti-4Cr alloy, namely the specific energy of damage (γ'), and the dissipative coefficient (β'), were determined from the fatigue data using the modified crack layer (MCL) theory. Fracture surface examination using scanning electron microscopy (SEM) revealed ductile failure mechanisms under tensile overloading conditions. The fatigue fracture surface of the V-4Ti-4Cr consists of three distinct regions, corresponding to the threshold, stable and unstable crack propagation stages. (orig.)

  10. 2nd Gen FeCrAl ODS Alloy Development For Accident-Tolerant Fuel Cladding

    Energy Technology Data Exchange (ETDEWEB)

    Dryepondt, Sebastien N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Massey, Caleb P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Edmondson, Philip D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-01

    Extensive research at ORNL aims at developing advanced low-Cr high strength FeCrAl alloys for accident tolerant fuel cladding. One task focuses on the fabrication of new low Cr oxide dispersion strengthened (ODS) FeCrAl alloys. The first Fe-12Cr-5Al+Y2O3 (+ ZrO2 or TiO2) ODS alloys exhibited excellent tensile strength up to 800 C and good oxidation resistance in steam up to 1400 C, but very limited plastic deformation at temperature ranging from room to 800 C. To improve alloy ductility, several fabrication parameters were considered. New Fe-10-12Cr-6Al gas-atomized powders containing 0.15 to 0.5wt% Zr were procured and ball milled for 10h, 20h or 40h with Y2O3. The resulting powder was then extruded at temperature ranging from 900 to 1050 C. Decreasing the ball milling time or increasing the extrusion temperature changed the alloy grain size leading to lower strength but enhanced ductility. Small variations of the Cr, Zr, O and N content did not seem to significantly impact the alloy tensile properties, and, overall, the 2nd gen ODS FeCrAl alloys showed significantly better ductility than the 1st gen alloys. Tube fabrication needed for fuel cladding will require cold or warm working associated with softening heat treatments, work was therefore initiated to assess the effect of these fabrications steps on the alloy microstructure and properties. This report has been submitted as fulfillment of milestone M3FT 16OR020202091 titled, Report on 2nd Gen FeCrAl ODS Alloy Development for the Department of Energy Office of Nuclear Energy, Advanced Fuel Campaign of the Fuel Cycle R&D program.

  11. Application of double-spike isotope dilution for the accurate determination of Cr(III), Cr(VI) and total Cr in yeast.

    Science.gov (United States)

    Yang, Lu; Ciceri, Elena; Mester, Zoltán; Sturgeon, Ralph E

    2006-11-01

    A method is presented for the simultaneous determination of Cr(III) and Cr(VI) in yeast using species-specific double-spike isotope dilution (SSDSID) with anion-exchange liquid chromatography (LC) separation and sector field inductively coupled plasma mass spectrometric (SF-ICP-MS) detection. Total Cr is quantitated using ID SF-ICP-MS. Samples were digested on a hot plate at 95+/-2 degrees C for 6 h in an alkaline solution of 0.5 M NaOH and 0.28 M Na2CO3 for the determination of Cr(III) and Cr(VI), whereas microwave-assisted decomposition with HNO3 and H2O2 was used for the determination of total Cr. Concentrations of 2,014+/-16, 1,952+/-103 and 76+/-48 mg kg-1 (one standard deviation, n=4, 3, 3), respectively were obtained for total Cr, Cr(III) and Cr(VI) in the yeast sample. Significant oxidation of Cr(III) to Cr(VI) (24.2+/-7.6% Cr(III) oxidized, n=3) and reduction of Cr(VI) to Cr(III) (37.6+/-6.5% Cr(VI) reduced, n=3) occurred during alkaline extraction and subsequent chromatographic separation at pH 7. Despite this significant bidirectional redox transformation, quantitative recoveries for both Cr(III) and Cr(VI) were achieved using the SSDSID method. In addition, mass balance between total Cr and the sum of Cr(III) and Cr(VI) concentrations was achieved. Method detection limits of 0.3, 2 and 30 mg kg-1 were obtained for total Cr, Cr(VI) and Cr(III), respectively, based on a 0.2-g sub-sample.

  12. Oxidation Behavior of Some Cr Ferritic Steels for High Temperature Fuel Cells

    International Nuclear Information System (INIS)

    Mohamed, H.E.

    2012-01-01

    The oxidation behavior of three high Cr ferritic steels designated 1Al, RA and 5Al with different levels of Al, Si, Mn and Hf has been investigated in the present work. These steels have been developed as candidates for Solid Oxide Fuel Cell (SOFC) interconnect. Specimens of these alloys have been subjected to isothermal as well as cyclic oxidation in air. Isothermal oxidation tests are conducted in the temperature range 800 - 1000 degree C for time periods up to 1000 h. cyclic oxidation tests were carried out at 800 and 1000 degree C for twenty 25 - h cycles giving a total cyclic exposure time of 500 h. The growth rate of the oxide scales was found to follow a parabolic law over a certain oxidation period which changed with alloy composition and oxidation temperature. The value of the parabolic rate constant increased with increasing oxidation temperature. At 800 and 900 degree C alloy 1Al exhibited higher oxidation resistance compared to the other two alloys. Alloy RA showed spalling behavior when oxidized at 900 degree C and the extent of spalling increased with increasing the oxidation temperature to 1000 degree C. Alloy 5Al oxidized at 1000 degree C showed the highest oxidation resistance among the investigated alloys. Alloy 1Al and RA showed similar scale morphology and composition. X- ray diffraction analysis revealed that the scales developed on these alloys consist of Cr 2 O 3 with an outer layer of MnCr 2 O 4 and a minor amount of FeCr 2 O 4 spinels. Alloy 5Al developed scale consisting of γ- Al 2 O 3 at 800 degree C and γ and α- Al 2 O 3 at 900 degree C. Oxidation of alloy 5Al at 1000 degree C led to formation of a scale consisting mainly of the protective phase α Al 2 O 3 . The presence of 0.84 wt% Al and 0.95 wt % Si in alloy 1Al enhanced its oxidation resistance compared to alloy RA which contains only 0.29 wt% Si and is Al - free. This enhancement was attributed to formation of internal oxidation zone in alloy 1Al just beneath the oxide / alloy

  13. Nuclear structure of light Ca and heavy Cr isotopes

    International Nuclear Information System (INIS)

    Buerger, A.

    2007-01-01

    In the present thesis, the shell structure in exotic nuclei has been investigated. The focus of the work was on finding new experimental data in neutron-rich Cr and proton-rich Ca isotopes. The investigation of light Ca isotopes concentrated on the nucleus 36 Ca which was produced in a knockout reaction from a radioactive 37 Ca beam. For 36 Ca, the excitation energy of the first 2 + state has been measured for the first time. Furthermore, momentum distributions were analyzed using a Monte-Carlo simulation of the knockout reaction. This analysis yielded the contributions of neutrons from individual orbitals to the total knockout cross section. In principle, these may be used to calculate spectroscopic factors, but such a calculation is hampered by difficulties of present knockout-reaction models in predicting precise single-particle cross sections. The measured branching ratio to the ground and excited states, on the other hand, is close to the predicted value. A remaining difference might be due to emission of protons which cannot be detected with the present experimental setup. Both the branching ratio and the large excitation energy are compatible with a large N=16 gap in 36 Ca that leads to relatively pure configurations both in the ground state and the excited 2 + state. As a by-product of the experiment, two excitation energies in the T=2 nuclei 32 Ar and 28 S have been confirmed, and two γ-ray transitions have been observed for the first time in 37 Ca. While the mirror energy differences in the T=2 pairs 36 Ca- 36 S, 32 Ar- 32 Si, and 28 S- 28 Mg can be reproduced in shell model calculations using a modified USD interaction, these modifications are not sufficient to explain the mirror energy differences for the pair 37 Ca- 37 Cl. In the heavy Cr isotopes, new experimental evidence for a sub-shell closure at N=32 was found in a measurement of B(E2) values using high-energy Coulomb excitation of radioactive beams. Prior to this experiment, the assumption of a

  14. Nuclear structure of light Ca and heavy Cr isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Buerger, A.

    2007-07-01

    In the present thesis, the shell structure in exotic nuclei has been investigated. The focus of the work was on finding new experimental data in neutron-rich Cr and proton-rich Ca isotopes. The investigation of light Ca isotopes concentrated on the nucleus {sup 36}Ca which was produced in a knockout reaction from a radioactive {sup 37}Ca beam. For {sup 36}Ca, the excitation energy of the first 2{sup +} state has been measured for the first time. Furthermore, momentum distributions were analyzed using a Monte-Carlo simulation of the knockout reaction. This analysis yielded the contributions of neutrons from individual orbitals to the total knockout cross section. In principle, these may be used to calculate spectroscopic factors, but such a calculation is hampered by difficulties of present knockout-reaction models in predicting precise single-particle cross sections. The measured branching ratio to the ground and excited states, on the other hand, is close to the predicted value. A remaining difference might be due to emission of protons which cannot be detected with the present experimental setup. Both the branching ratio and the large excitation energy are compatible with a large N=16 gap in {sup 36}Ca that leads to relatively pure configurations both in the ground state and the excited 2{sup +} state. As a by-product of the experiment, two excitation energies in the T=2 nuclei {sup 32}Ar and {sup 28}S have been confirmed, and two {gamma}-ray transitions have been observed for the first time in {sup 37}Ca. While the mirror energy differences in the T=2 pairs {sup 36}Ca-{sup 36}S, {sup 32}Ar-{sup 32}Si, and {sup 28}S-{sup 28}Mg can be reproduced in shell model calculations using a modified USD interaction, these modifications are not sufficient to explain the mirror energy differences for the pair {sup 37}Ca-{sup 37}Cl. In the heavy Cr isotopes, new experimental evidence for a sub-shell closure at N=32 was found in a measurement of B(E2) values using high-energy

  15. Homogeneous and Heterogeneous (Fex, Cr1-x)(OH)3 Precipitation: Implications for Cr Sequestration.

    Science.gov (United States)

    Dai, Chong; Zuo, Xiaobing; Cao, Bo; Hu, Yandi

    2016-02-16

    The formation of (Fe, Cr)(OH)3 nanoparticles determines the fate of aqueous Cr in many aquatic environments. Using small-angle X-ray scattering, precipitation rates of (Fe, Cr)(OH)3 nanoparticles in solution and on quartz were quantified from 0.1 mM Fe(III) solutions containing 0-0.25 mM Cr(III) at pH = 3.7 ± 0.2. Concentration ratio of aqueous Cr(III)/Fe(III) controlled the chemical composition (x) of (Fex, Cr1-x)(OH)3 precipitates, solutions' supersaturation with respect to precipitates, and the surface charge of quartz. Therefore, the aqueous Cr(III)/Fe(III) ratio affected homogeneous (in solution) and heterogeneous (on quartz) precipitation rates of (Fex, Cr1-x)(OH)3 through different mechanisms. The sequestration mechanisms of Cr(III) in precipitates were also investigated. In solutions with high aqueous Cr(III)/Fe(III) ratios, surface enrichment of Cr(III) on the precipitates occurred, resulting in slower particle growth in solutions. From solutions with 0-0.1 mM Cr(III), the particles on quartz grew from 2 to 4 nm within 1 h. Interestingly, from solution with 0.25 mM Cr(III), particles of two distinct sizes (2 and 6 nm) formed on quartz, and their sizes remained unchanged throughout the reaction. Our study provided new insights on homogeneous and heterogeneous precipitation of (Fex, Cr1-x)(OH)3 nanoparticles, which can help determine the fate of Cr in aquatic environments.

  16. Preliminary Microstructural and Microscratch Results of Ni-Cr-Fe and Cr3C2-NiCr Coatings on Magnesium Substrate

    Science.gov (United States)

    Istrate, B.; Munteanu, C.; Lupescu, S.; Benchea, M.; Vizureanu, P.

    2017-06-01

    Thermal coatings have a large scale application in aerospace and automotive field, as barriers improving wear mechanical characteristics and corrosion resistance. In present research, there have been used two types of coatings, Ni-Cr-Fe, respectively Cr3C2-NiCr which were deposited on magnesium based alloys (pure magnesium and Mg-30Y master alloy). There have been investigated the microstructural aspects through scanning electronic microscopy and XRD analysis and also a series of mechanical characteristics through microscratch and indentation determinations. The results revealed the formation of some adherent layers resistant to the penetration of the metallic indenter, the coatings did not suffer major damages. Microstructural analysis highlighted the formation of Cr3C2, Cr7C3, Cr3Ni2, Cr7Ni3, FeNi3, Cr-Ni phases. Also, the apparent coefficient of friction for Ni-Cr-Fe coatings presents superior values than Cr3C2-NiCr coatings.

  17. Electron scattering by 52Cr, (1)

    International Nuclear Information System (INIS)

    Hayakawa, Ken; Okazaki, Yukio; Oyamada, Masayuki; Torizuka, Yoshiharu; Arita, K.

    1974-01-01

    The ground state of 52 Cr has relatively simple coordination, i.e., it is the closed shell for neutrons and has fsub(7/2) 4 state of protons. Several excitation states can be generated from this only one coordination. These states are characterized by seniority as well as spin and parity. Because of the requirement of anti-symmetry of wave functions, really probable states are those with seniority V=2 and angular momentum J=2, 4 and 6, and those with V=4 and J=2, 4, 5 and 8. These states are expected to have low exciting energy. As to the transition among these states or the excitation from ground states, seniority selection rule restricts the transition, therefore all transition of ΔV=4 is forbidden. The electrical transition of ΔV=0 is also forbidden. In some experiments, however, the γ ray emissive transition from 6 + state of V=2 to both 4 + state of V=2 and 4 + state of V=4 has been observed. Moreover, the forbidden γ ray transition from 4 + state of V=2 to 2 + state of V=2 has been observed. It is interpreted that the occurrence of such forbidden transition is due to the seniority mixing in each state. The experiment, reported in this paper, shows that this phenomenon of forbidden transition can not be explained only by employing the seniority mixing. (Tai, I.)

  18. Magnetic dipole excitations of 50Cr

    Science.gov (United States)

    Pai, H.; Beck, T.; Beller, J.; Beyer, R.; Bhike, M.; Derya, V.; Gayer, U.; Isaak, J.; Krishichayan, Kvasil, J.; Löher, B.; Nesterenko, V. O.; Pietralla, N.; Martínez-Pinedo, G.; Mertes, L.; Ponomarev, V. Yu.; Reinhard, P.-G.; Repko, A.; Ries, P. C.; Romig, C.; Savran, D.; Schwengner, R.; Tornow, W.; Werner, V.; Wilhelmy, J.; Zilges, A.; Zweidinger, M.

    2016-01-01

    The low-lying M 1 strength of the open-shell nucleus 50Cr has been studied with the method of nuclear resonance fluorescence up to 9.7 MeV using bremsstrahlung at the superconducting Darmstadt linear electron accelerator S-DALINAC and Compton backscattered photons at the High Intensity γ -ray Source (HI γ S ) facility between 6 and 9.7 MeV of the initial photon energy. Fifteen 1+ states have been observed between 3.6 and 9.7 MeV. Following our analysis the lowest 1+ state at 3.6 MeV can be considered as an isovector orbital mode with some spin admixture. The obtained results generally match the estimations and trends typical for the scissors-like mode. Detailed calculations within the Skyrme quasiparticle random-phase-approximation method and the large-scale shell model justify our conclusions. The calculated distributions of the orbital current for the lowest 1+-state suggest the schematic view of Lipparini and Stringari (isovector rotation-like oscillations inside the rigid surface) rather than the scissors-like picture of Lo Iudice and Palumbo. The spin M 1 resonance is shown to be mainly generated by spin-flip transitions between the orbitals of the f p shell.

  19. Structure and magnetic properties of Cr nanoparticles and Cr2O3 nanoparticles

    International Nuclear Information System (INIS)

    Zhang, W.S.; Brueck, E.; Zhang, Z.D.; Tegus, O.; Li, W.F.; Si, P.Z.; Geng, D.Y.; Buschow, K.H.J.

    2005-01-01

    We have synthesized Cr nanoparticles by arc-discharge and Cr 2 O 3 nanoparticles by subsequent annealing the as-prepared Cr nanoparticles. The structure of these nanoparticles is studied by means of X-ray diffraction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscope. Most of the particles show a good crystal habit of well-defined cubic or orthorhombic shape, while some small particles show spherical shape. The as-prepared Cr nanoparticles have a BCC Cr core coated with a thin Cr 2 O 3 layer. Cr in the core of the particles heated at 873 K for 4 h is changed to Cr 2 O 3 . The results of magnetic measurements show that the Cr nanoparticles exhibit mainly antiferromagnetic properties, in addition to a weak-ferromagnetic component at lower fields. The weak-ferromagnetic component may be ascribed to uncompensated surface spins. For the field-cooled Cr 2 O 3 nanoparticles, an exchange bias is observed in the hysteresis loops, which can be interpreted as the exchange coupling between the uncompensated spins at the surface and the spins in the core of the Cr 2 O 3 nanoparticles

  20. Removal of Cr(VI) ions by sewage sludge compost biomass from aqueous solutions: Reduction to Cr(III) and biosorption

    Science.gov (United States)

    Chen, Huixia; Dou, Junfeng; Xu, Hongbin

    2017-12-01

    Sewage sludge compost biomass was used as a novel biosorbent to remove hexavalent chromium from water. Surface area analysis, scanning electron microscopy, fourier-transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and point zero charge was applied to study the microstructure, compositions and chemical bonding states of the biomass adsorbent. Effects of contact time, biomass dosage, agitation speed, pH, the initial concentration of Cr(VI) and Cr(Ⅲ) on its adsorption removal were also performed in the batch experiments. A model describing adsorption, desorption and reduction phenomena during the sorption process has been referenced to model Cr(VI) sorption onto sewage sludge compost biomass. The result of characterization test shows that adsorption of Cr(VI) onto sewage sludge compost biomass followed by the partial reduction to Cr(Ⅲ) by biomass groups such as hydroxyl, carboxyl, and amino groups. The absorption kinetics model in the description of adsorption-coupled reduction of Cr(VI) fits successfully the kinetic data obtained at different temperatures and describes the kinetics profile of total, hexavalent and trivalent chromium. The study shows that sewage sludge compost biomass could be used as a potential biosorbent for removal of hexavalent chromium from wastewaters.

  1. Plantago lanceolata growth and Cr uptake after mycorrhizal inoculation in a Cr amended substrate

    Directory of Open Access Journals (Sweden)

    Amaia Nogales

    2012-03-01

    Full Text Available Arbuscular mycorrhizal fungi from two chromium contaminated sites, one with 275 mg kg-1 of Cr (zone A and the other with 550 mg kg-1 Cr (zone B, were multiplied and tentatively identified. The effect of both fungal consortia on Plantago lanceolata plant growth in a substrate amended with 200 mg kg-1 of Cr and with 400 mg kg-1 Cr was assessed and compared with the growth of plants inoculated with Glomus intraradices BEG72. Only the plants inoculated with G. intraradices BEG72 and with the fungal consortia obtained from the area with a high Cr contamination (zone B grew in the soil with 400 mg kg-1 of Cr. The consortia of fungi from zone B, decreased the plant’s uptake/translocation of the heavy metal compared with G. intraradices BEG72. These results underscore the differential effect of AM fungi in conferring bioprotection in Cr contaminated soils.

  2. Calculating CR-39 Response to Radon in Water Using Monte Carlo Simulation

    International Nuclear Information System (INIS)

    Razaie Rayeni Nejad, M. R.

    2012-01-01

    CR-39 detectors are widely used for Radon and progeny measurement in the air. In this paper, using the Monte Carlo simulation, the possibility of using the CR-39 for direct measurement of Radon and progeny in water is investigated. Assuming the random position and angle of alpha particle emitted by Radon and progeny, alpha energy and angular spectrum that arrive at CR-39, the calibration factor, and the suitable depth of chemical etching of CR-39 in air and water was calculated. In this simulation, a range of data were obtained from SRIM2008 software. Calibration factor of CR-39 in water is calculated as 6.6 (kBq.d/m 3 )/(track/cm 2 ) that is corresponding with EPA standard level of Radon concentration in water (10-11 kBq/m 3 ). With replacing the skin instead of CR-39, the volume affected by Radon and progeny was determined to be 2.51 mm 3 for one m 2 of skin area. The annual dose conversion factor for Radon and progeny was calculated to be between 8.8-58.8 nSv/(Bq.h/m 3 ). Using the CR-39 for Radon measurement in water can be beneficial. The annual dose conversion factor for Radon and progeny was calculated to be between 8.8-58.8 nSv/ (Bq.h/m 3 ).

  3. Manufacturing of Porous Al-Cr Preforms for Composite Reinforcing Using Microwave Activated Combustion Synthesis

    Directory of Open Access Journals (Sweden)

    Naplocha K.

    2014-10-01

    Full Text Available The combustion synthesis of porous skeletons (preforms of intermetallic Al–Cr compounds intended for metal matrix composite MMC reinforcing was developed. Mixture of Al and Cr powders with granularity of −10, −44, −74mm were cold isostatic pressed and next ignited and synthetized in a microwave reactor under argon atmosphere (microwave-activated combustion synthesis MACS. In order to ignite the synthesis, microwave energy was focused by a tuner on the specimen. The analysis of reaction temperature diagrams revealed that the synthesis proceeded through the following peritectic transformations: L(liquidus+Al7Cr→L+Al11Cr2→L+Al4Cr. Moreover, EDS and XRD examinations showed that the reaction proceeded between a solid Cr and a liquid Al to create a distinct envelope of Al9Cr4 on Cr particle which next extended and spreaded over the entire structure. The produced preforms with uniform structure and interconnected porosity were infiltrated with liquid Cu and Al alloy. The obtained composite materials exhibited high hardness, wear and distinct temperature oxidation resistance.

  4. Electron microscopy characterization of Ni-Cr-B-Si-C laser deposited coatings.

    Science.gov (United States)

    Hemmati, I; Rao, J C; Ocelík, V; De Hosson, J Th M

    2013-02-01

    During laser deposition of Ni-Cr-B-Si-C alloys with high amounts of Cr and B, various microstructures and phases can be generated from the same chemical composition that results in heterogeneous properties in the clad layer. In this study, the microstructure and phase constitution of a high-alloy Ni-Cr-B-Si-C coating deposited by laser cladding were analyzed by a combination of several microscopy characterization techniques including scanning electron microscopy in secondary and backscatter imaging modes, energy dispersive spectroscopy (EDS), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). The combination of EDS and EBSD allowed unequivocal identification of micron-sized precipitates as polycrystalline orthorhombic CrB, single crystal tetragonal Cr5B3, and single crystal hexagonal Cr7C3. In addition, TEM characterization showed various equilibrium and metastable Ni-B, Ni-Si, and Ni-Si-B eutectic products in the alloy matrix. The findings of this study can be used to explain the phase formation reactions and to tune the microstructure of Ni-Cr-B-Si-C coatings to obtain the desired properties.

  5. Photofunctional Co-Cr Alloy Generating Reactive Oxygen Species for Photodynamic Applications

    Directory of Open Access Journals (Sweden)

    Kang-Kyun Wang

    2013-01-01

    Full Text Available We report the fabrication of photofunctional Co-Cr alloy plate that is prepared by a simple modification process for photodynamic application. Photoinduced functionality is provided by the photosensitizer of hematoporphyrin (Hp that initially generates reactive oxygen species (ROS such as superoxide anion radical and singlet oxygen. The photosensitizer with carboxyl group was chemically bonded to the surface of the Co-Cr alloy plate by esterification reaction. Microstructure and elemental composition of the Co-Cr alloy plate were checked with scanning electron microscopy (SEM and energy dispersive X-ray spectrometer (EDS. Fabrication of the photofunctionality of the Co-Cr alloy plate was confirmed with X-ray photoelectron spectroscopy (XPS, reflectance UV-Vis absorption, and emission spectroscopy. Reactive oxygen generation from the photofunctional Co-Cr alloy plate was confirmed by using the decomposition reaction of 1,3-diphenylisobenzofuran (DPBF. The results suggest that the immobilized photosensitizer molecules on the surface of Co-Cr alloy plate still possess their optical and functional properties including reactive oxygen generation. To open the possibility for its application as a photodynamic material to biological system, the fabricated photofunctional Co-Cr alloy is applied to the decomposition of smooth muscle cells.

  6. Observations of copper clustering in a 25Cr-7Ni super duplex stainless steel during low-temperature aging under load

    Science.gov (United States)

    Thuvander, M.; Zhou, J.; Odqvist, J.; Hertzman, S.; Hedström, P.

    2012-07-01

    Atom-probe tomography was used to investigate phase separation and copper (Cu) clustering in the ferrite phase of a 25Cr-7Ni super duplex stainless steel. The steel was subjected to a tensile load during aging at 325°C for 5800 h. The degree of phase separation into α (Fe-rich) and α‧ (Cr-rich) was small, but still, it was the highest in the steel subjected to the highest load. Cu was found to cluster, and the number density of clusters increased with increasing load. In the material subjected to the highest load, Cu was enriched in regions that were neither Fe-rich nor Cr-rich. These regions also had the highest number density of Cu clusters.

  7. Effect of Pb and Cr Substitutions on Phase Formation and Excess Conductivity of Bi-2212 Superconductor

    International Nuclear Information System (INIS)

    Khir, F. L. M.; Mohamed, Z.; Yusuf, A. A.; Yusof, M. I. M.; Yahya, A. K.

    2010-01-01

    The influence of Pb and Cr substitutions on the superconducting properties of Bi 2 Sr 2 CaCu 2 O 8 (Bi-2212) superconductors is reported. The samples were prepared from Bi 2-x Pb x Sr 2 Ca 2-y Cr y Cu 3 O 10-δ (x = 0-0.3, y = 0-0.3) starting composition by the solid-state-reaction method. XRD analysis showed formation of pure Bi-2212 for (x = 0, y = 0), (x = 0.3, y = 0.2,) and (x = 0.3, y = 0.2,) starting compositions. Excess conductivity analysis based on Asmalazov-Larkin theory on single-phased Bi2212 samples showed 2D to 3D transition in superconducting fluctuation behavior (SFB) for all the samples. Highest 2D-3D transition temperature, T 2D-3D was observed at Pb and Cr substitutions of x = 0.3, and x = 0.2, respectively.

  8. Mineral Composition and Nutritive Value of Isotonic and Energy Drinks.

    Science.gov (United States)

    Leśniewicz, Anna; Grzesiak, Magdalena; Żyrnicki, Wiesław; Borkowska-Burnecka, Jolanta

    2016-04-01

    Several very popular brands of isotonic and energy drinks consumed for fluid and electrolyte supplementation and stimulation of mental or physical alertness were chosen for investigation. Liquid beverages available in polyethylene bottles and aluminum cans as well as products in the form of tablets and powder in sachets were studied. The total concentrations of 21 elements (Ag, Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Na, Ni, P, Pb, Sr, Ti, V, and Zn), both essential and toxic, were simultaneously determined in preconcentrated drink samples by inductively coupled plasma-optical emission spectrometry (ICP-OES) equipped with pneumatic and ultrasonic nebulizers. Differences between the mineral compositions of isotonic and energy drinks were evaluated and discussed. The highest content of Na was found in both isotonic and energy drinks, whereas quite high concentrations of Mg were found in isotonic drinks, and the highest amount of calcium was quantified in energy drinks. The concentrations of B, Co, Cu, Ni, and P were higher in isotonic drinks, but energy drinks contained greater quantities of Ag, Cr, Zn, Mn, and Mo and toxic elements, as Cd and Pb. A comparison of element contents with micronutrient intake and tolerable levels was performed to evaluate contribution of the investigated beverages to the daily diet. The consumption of 250 cm(3) of an isotonic drink provides from 0.32% (for Mn) up to 14.8% (for Na) of the recommended daily intake. For the energy drinks, the maximum recommended daily intake fulfillment ranged from 0.02% (for V) to 19.4 or 19.8% (for Mg and Na).

  9. Bonding and bio-properties of hybrid laser/magnetron Cr-enriched DLC layers

    Energy Technology Data Exchange (ETDEWEB)

    Jelinek, Miroslav, E-mail: jelinek@fzu.cz [Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i, Na Slovance 2, 18221 Prague (Czech Republic); Czech Technical University in Prague, Faculty of Biomedical Engineering, nam. Sitna 3105, 27201 Kladno (Czech Republic); Zemek, Josef [Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i, Na Slovance 2, 18221 Prague (Czech Republic); Vandrovcová, Marta; Bačáková, Lucie [Institute of Physiology of the Czech Academy of Sciences of the Czech Republic, v.v.i., Videnska 1083, 14220 Prague 4 (Czech Republic); Kocourek, Tomáš; Remsa, Jan; Písařík, Petr [Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i, Na Slovance 2, 18221 Prague (Czech Republic); Czech Technical University in Prague, Faculty of Biomedical Engineering, nam. Sitna 3105, 27201 Kladno (Czech Republic)

    2016-01-01

    Chromium-enriched diamond-like carbon (DLC) layers were prepared by a hybrid technology using a combination of pulsed laser deposition (PLD) and magnetron sputtering. XRD revealed no chromium peaks, indicating that the layers are mostly amorphous. Carbon (sp{sup 2} and sp{sup 3} bonds) and chromium bonds were determined by XPS from C 1s, O 1s, and Cr 2p photoelectron peaks. Depending on the deposition conditions, the concentration of Cr in DLC layers moved from zero to 10 at.% for as-received sample surfaces, and to about 31 at.% after mild sputter-cleaning by argon ion cluster beam. It should be noted that the most stable Cr{sup 3+} bonding state is in Cr{sub 2}O{sub 3} and Cr(OH){sub 3}, and that there is the toxic Cr{sup 6+} state in CrO{sub 3}. The surface content of hexavalent chromium in the Cr 2p3/2 spectra is rather low, but discernible. The population density of Saos-2 cells was the highest in samples containing higher concentrations of chromium 7.7 and 10 at.%. This means that higher concentrations of chromium supported the cell adhesion and proliferation. In addition, as revealed by a LIVE/DEAD viability/cytotoxicity kit, the cells on all Cr-containing samples maintained high viability (96 to 99%) on days 1 and 3 after seeding. However, this seemingly positive cell behavior could be associated with the risk of dedifferentiation and oncogenic transformation of cells. - Highlights: • DLC and chromium-enriched DLC layers were prepared by hybrid laser–magnetron deposition. • The content of chromium in DLC varied up to 10 at.% (31 at.% after ion beam sputtering). • The surface content of toxic hexavalent chromium in the Cr 2p3/2 spectra is rather low but discernible. • Higher concentrations of chromium supported the cell adhesion and proliferation. • Cells on all Cr-containing samples maintained high viability (96 to 99%).

  10. Distinct effects of Cr bulk doping and surface deposition on the chemical environment and electronic structure of the topological insulator Bi{sub 2}Se{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, Turgut, E-mail: yilmaz@phys.uconn.edu [Department of Physics, University of Connecticut, Storrs, CT 06269 (United States); Hines, William [Department of Physics, University of Connecticut, Storrs, CT 06269 (United States); Sun, Fu-Chang [Department of Materials Science and Engineering, University of Connecticut, Storrs, CT 06269 (United States); Pletikosić, Ivo [Department of Physics, Princeton University, Princeton, NJ 08544 (United States); Budnick, Joseph [Department of Physics, University of Connecticut, Storrs, CT 06269 (United States); Valla, Tonica [Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Sinkovic, Boris [Department of Physics, University of Connecticut, Storrs, CT 06269 (United States)

    2017-06-15

    Highlights: • Cr doping into the bulk of Bi{sub 2}Se{sub 3} opens an energy gap at the Dirac point which is observable in the non-magnetic state. • Cr surface deposition does not lead to open an energy gap at the Dirac point of Bi{sub 2}Se{sub 3}. • Formation of two distinct Bi and Cr core level peaks was observed upon the deposition of Cr on the surface of Bi{sub 2}Se{sub 3}. - Abstract: In this report, it is shown that Cr doped into the bulk and Cr deposited on the surface of Bi{sub 2}Se{sub 3} films produced by molecular beam epitaxy (MBE) have strikingly different effects on both the electronic structure and chemical environment. Angle resolved photoemission spectroscopy (ARPES) shows that Cr doped into the bulk opens a surface state energy gap which can be seen at room temperature; much higher than the measured ferromagnetic transition temperature of ≈10 K. On the other hand, similar ARPES measurements show that the surface states remain gapless down to 15 K for films with Cr surface deposition. In addition, core-level photoemission spectroscopy of the Bi 5d, Se 3d, and Cr 3p core levels show distinct differences in the chemical environment for the two methods of Cr introduction. Surface deposition of Cr results in the formation of shoulders on the lower binding energy side for the Bi 5d peaks and two distinct Cr 3p peaks indicative of two Cr sites. These striking differences suggests an interesting possibility that better control of doping at only near surface region may offer a path to quantum anomalous Hall states at higher temperatures than reported in the literature.

  11. Physical and spectroscopic studies of Cr{sup 3+} doped mixed alkaline earth oxide borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Samdani, E-mail: samdanimohd82@gmail.com [Department of Engineering, Salalah College of Technology, Salalah (Oman); Ramadevudu, G. [Department of Physics, Vasavi College of Engineering, Ibrahimbagh, Hyderabad 500031, Telangana (India); Chary, M. Narasimha; Shareefuddin, Md. [Department of Physics, Osmania University, Hyderabad 500007, Telangana (India)

    2017-01-15

    A series of mixed alkaline earth oxide glasses xMgO-(30-x)BaO-69.8B{sub 2}O{sub 3}-0.2Cr{sub 2}O{sub 3} were prepared and studied using electron paramagnetic resonance (EPR), optical absorption, Raman spectroscopy and photoluminescence experimental techniques. The optical absorption spectra revealed the characteristic octahedral symmetry of Cr{sup 3+}ions through three broad band transitions {sup 4}A{sub 2g}(F)→ {sup 4}T{sub 2g}(F), {sup 4}A{sub 2g}(F)→ {sup 4}T{sub 1g}(F), and {sup 4}A{sub 2g}(F)→ {sup 2}T{sub 1g}(P). The crystal field (Dq) and Racah parameters (B and C), the optical band gap and Urbach energies of the glass samples were also reported along with the physical properties like density and molar volume. In the EPR spectra three resonance signals corresponding to Cr3+ ions were observed. A broad signal with g = 5.110 was observed which belongs to the isolated Cr3+ centers localized in the strongly distorted octahedral (rhombic) sites of the glass network, a narrow signal (g = 1.960) corresponding to the Cr{sup 3+} centers in the weekly distorted (cubic) sites of the glass network, and a third very broad signal (g = 2.210) was also observed corresponding to Cr{sup 3+}- Cr{sup 3+} paired centers coupled by magnetic dipolar interaction. Another resonance signal with effective value g ≈ 4.220 was attributed to Fe{sup 3+} ions impurity. The number of spins (N) participating in the resonance and susceptibility (χ) values at room temperature were reported and their values varied in a non-linear manner with the composition exhibiting mixed oxide effect. The estimated molecular bonding coefficients (α) values indicated stronger ionic contribution. The Raman spectral investigations were carried out. The Photoluminescence spectra bands near 690 and 750 nm correspond to the Cr{sup 3+} centers in high and low field sites respectively. - Highlights: • Spectroscopic studies were made on alkaline earth borate glasses. • Three resonance signals

  12. Ostwald ripening of decomposed phases in Cu-Ni-Cr alloys

    International Nuclear Information System (INIS)

    Hernandez-Santiago, Felipe; Lopez-Hirata, Victor; Dorantes-Rosales, Hector J.; Saucedo-Munoz, Maribel L.; Gonzalez-Velazquez, Jorge L.; Paniagua-Mercado, Ana Ma.

    2008-01-01

    A study of the coarsening process of the decomposed phases was carried out in the Cu-34 wt.% Ni-4 wt.% Cr and Cu-45 wt.% Ni-10 wt.% Cr alloys using transmission electron microscopy. As aging progressed, the morphology of the coherent decomposed Ni-rich phase changed from cuboids to platelets aligned in the Cu-rich matrix directions. Prolonged aging caused the loss of coherency between the decomposed phases and the morphology of the Ni-rich phase changed to ellipsoidal. The variation of mean radius of the coherent decomposed phases with aging time followed the modified LSW theory for thermally activated growth in ternary alloy systems. The linear variation of the density number of precipitates and matrix supersaturation with aging time, also confirmed that the coarsening process followed the modified LSW theory in both alloys. The coarsening rate was faster in the symmetrical Cu-45 wt.% Ni-10 wt.% Cr alloy due to its higher volume fraction of precipitates. The activation energy for thermally activated growth was determined to be about 182 and 102 kJ mol -1 in the Cu-34 wt.% Ni-4 wt.% Cr and Cu-45 wt.% Ni-10 wt.% Cr alloys, respectively. The lower energy for the former alloy seems to be related to an increase in the atomic diffusion process as the chromium content increases. The size distributions of precipitates in the Cu-Ni-Cr alloys were broader and more symmetric than that predicted by the modified LSW theory for ternary alloys

  13. Gamma irradiation effects on the thermal, optical and structural properties of Cr-39 nuclear track detector

    International Nuclear Information System (INIS)

    Nouh, S.A.; Said, A.F.; Atta, M.R.; EL-Mellegy, W.M.; EL-Meniawi, S.

    2006-01-01

    A study of the effect of gamma irradiation on the thermal, optical and structural properties of CR-39 diglycol carbonate solid state nuclear track detector (SSNTD) has been carried out. Samples from CR-39 polymer were irradiated with gamma doses at levels between 20 and 300 KGy. Non-isothermal studies were carried out using thermo-gravimetry (TG), differential thermo-gravimetry (DTG) and differential thermal analysis (DTA) to obtain the activation energy of decomposition and the transition temperatures for the non-irradiated and irradiated CR-39 samples. In addition, optical and structural property studies were performed on non-irradiated and irradiated CR-39 samples using refractive index and X-ray diffraction measurements. The variation of onset temperature of decomposition (To) thermal activation energy of decomposition (Ea) melting temperature (Tm) refractive index (n) and the mass fraction of the amorphous phase with the gamma dose were studied. It was found that many changes in the thermal, optical and structural properties of the CR-39 polymer could be produced by gamma irradiation via the degradation and cross linking mechanisms. Also, the gamma dose gave an advantage for increasing the correlation between the thermal stability of CR-39 polymer and the bond formation created by the ionizing effect of gamma radiation

  14. The relationships between heavy metal (Cd, Cr, Cu, Fe, Pb, Zn) levels and the size of six Mediterranean fish species

    International Nuclear Information System (INIS)

    Canli, Mustafa; Atli, Gueluezar

    2003-01-01

    Significant relationships between metal concentrations and fish size were negative. - Heavy metal (Cd, Cr, Cu, Fe, Pb, Zn) concentrations in the muscle, gill and liver of six fish species (Sparus auratus, Atherina hepsetus, Mugil cephalus, Trigla cuculus, Sardina pilchardus and Scomberesox saurus) from the northeast Mediterranean Sea were measured and the relationships between fish size (length and weight) and metal concentrations in the tissues were investigated by linear regression analysis. Metal concentrations (as μg/g d.w.) were highest in the liver, except for iron in the gill of Scomberesox saurus and lowest in the muscle of all the fish species. Highest concentrations of Cd (4.50), Cr (17.1) and Pb (41.2) were measured in liver tissues of T. cuculus, Sardina pilchardus and A. hepsetus, respectively. The liver of M. cephalus showed strikingly high Cu concentrations (202.8). The gill of Scomberesox saurus was the only tissue that showed highest (885.5) iron concentrations. Results of linear regression analysis showed that, except in a few cases, significant relationships between metal concentrations and fish size were negative. Highly significant (P<0.001) negative relationships were found between fish length and Cr concentrations in the liver of A. hepsetus and M. cephalus, and Cr concentrations in the gill of T. cuculus. Cr and Pb concentrations in the liver and Cu concentrations in all the tissues of Scomberesox saurus also showed very significant (P<0.001) negative relationships. Negative relationships found here were discussed

  15. Heavy doping of CdTe single crystals by Cr ion implantation

    Science.gov (United States)

    Popovych, Volodymyr D.; Böttger, Roman; Heller, Rene; Zhou, Shengqiang; Bester, Mariusz; Cieniek, Bogumil; Mroczka, Robert; Lopucki, Rafal; Sagan, Piotr; Kuzma, Marian

    2018-03-01

    Implantation of bulk CdTe single crystals with high fluences of 500 keV Cr+ ions was performed to achieve Cr concentration above the equilibrium solubility limit of this element in CdTe lattice. The structure and composition of the implanted samples were studied using secondary ion mass spectrometry (SIMS), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS) to characterize the incorporation of chromium into the host lattice and to investigate irradiation-induced damage build-up. It was found that out-diffusion of Cr atoms and sputtering of the targets alter the depth distribution and limit concentration of the projectile ions in the as-implanted samples. Appearance of crystallographically oriented, metallic α-Cr nanoparticles inside CdTe matrix was found after implantation, as well as a strong disorder at the depth far beyond the projected range of the implanted ions.

  16. Structural evolution of Ni-20Cr alloy during ball milling of elemental powders

    International Nuclear Information System (INIS)

    Lopez B, I.; Trapaga M, L. G.; Martinez F, E.; Zoz, H.

    2011-01-01

    The ball milling (B M) of blended Ni and Cr elemental powders was carried out in a Simoloyer performing on high-energy scale mode at maximum production to obtain a nano structured Ni-20Cr alloy. The phase transformations and structural changes occurring during mechanical alloying were investigated by X-ray diffraction (XRD) and optical microscopy (Om). A gradual solid solubility of Cr and the subsequent formation of crystalline metastable solid solutions described in terms of the Avrami-Ero fe ev kinetics model were calculated. The XRD analysis of the structure indicates that cumulative lattice strain contributes to the driving force for solid solution between Ni and Cr during B M. Microstructure evolution has shown, additionally to the lamellar length refinement commonly observed, the folding of lamellae in the final processing stage. Om observations revealed that the lamellar spacing of Ni rich zones reaches a steady value near 500 nm and almost disappears after 30 h of milling. (Author)

  17. Migration mechanisms of self-interstitial atoms and their clusters in Fe-Cr alloys

    International Nuclear Information System (INIS)

    Terentyev, D.; Malerba, L.

    2006-06-01

    The mobility of self-interstitial atoms (SIAs) and their clusters in pure iron and iron-chromium alloys was studied by atomic scale modelling techniques. Molecular dynamics (MD) was used to simulate thermally activated motion, i.e. diffusion, and its mechanisms whereas molecular statics was used to estimate energies of interactions of SIA and SIA clusters with Cr-impurities. It is shown that the presence of Cr atoms reduces the diffusivity of SIAs and their clusters in a non monotonic way with increasing Cr concentration. The main reason for this reduction is the presence of a long-range attractive interaction between self-interstitials in the crowdion configuration and Cr atoms. The migration mechanisms behind this effect are discussed relying on the results obtained from the MD simulations. (author)

  18. gamma-induced modification on optical band gap of CR-39 SSNTD

    International Nuclear Information System (INIS)

    Zaki, M.F.

    2010-01-01

    effect of gamma irradiation on optical absorption of nuclear track detectors like CR-39 was studied at different absorbed doses using ultraviolet-visible (UV-VIS)spectroscopy. the existence of the peaks, their shifting and broadening as a result of gamma irradiation has been discussed. the width of the tail of localized states in the band gap (E u )was evaluated using the Urbach edge method. finally the indirect and direct band gap in pristine and gamma irradiated CR-39 have been determined. the values of indirect band gap have been found to be lower than the corresponding values of direct band gap. a decrease in the optical energy gap with increasing the gamma absorbed dose can be discussed on the basis of gamma-irradiation-induced defects in the CR-39. the correlation between optical band gap and the number of carbon atoms in a cluster with modified Tauc's equation has been discussed in case of CR-39.

  19. Dose-equivalent response CR-39 track detector for personnel neutron dosimetry

    International Nuclear Information System (INIS)

    Oda, K.; Ito, M.; Yoneda, H.; Miyake, H.; Yamamoto, J.; Tsuruta, T.

    1991-01-01

    A dose-equivalent response detector based on CR-39 has been designed to be applied for personnel neutron dosimetry. The intrinsic detection efficiency of bare CR-39 was first evaluated from irradiation experiments with monoenergetic neutrons and theoretical calculations. In the second step, the radiator effect was investigated for the purpose of sensitization to fast neutrons. A two-layer radiator consisting of deuterized dotriacontane (C 32 D 66 ) and polyethylene (CH 2 ) was designed. Finally, we made the CR-39 detector sensitive to thermal neutrons by doping with orthocarbone (B 10 H 12 C 2 ), and also estimated the contribution of albedo neutrons. It was found that the new detector - boron-doped CR-39 with the two-layer radiator - would have a flat response with an error of about 70% in a wide energy region, ranging from thermal to 15 MeV. (orig.)

  20. Interatomic Potential to Simulate Radiation Damage in Fe-Cr Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Bonny, G.; Pasianot, R.; Terentyev, D.; Malerba, L.

    2011-03-15

    The report presents an Fe-Cr interatomic potential to model high-Cr ferritic alloys. The potential is fitted to thermodynamic and point-defect properties obtained from density functional theory (DFT) calculations and experiments. The developed potential is also benchmarked against other potentials available in literature. It shows particularly good agreement with the DFT obtained mixing enthalpy of the random alloy, the formation energy of intermetallics and experimental excess vibrational entropy and phase diagram. In addition, DFT calculated point-defect properties, both interstitial and substitutional, are well reproduced, as is the screw dislocation core structure. As a first validation of the potential, we study the precipitation hardening of Fe-Cr alloys via static simulations of the interaction between Cr precipitates and screw dislocations. It is concluded that the description of the dislocation core modification near a precipitate might have a significant influence on the interaction mechanisms observed in dynamic simulations.

  1. Interatomic Potential to Simulate Radiation Damage in Fe-Cr Alloys

    International Nuclear Information System (INIS)

    Bonny, G.; Pasianot, R.; Terentyev, D.; Malerba, L.

    2011-01-01

    The report presents an Fe-Cr interatomic potential to model high-Cr ferritic alloys. The potential is fitted to thermodynamic and point-defect properties obtained from density functional theory (DFT) calculations and experiments. The developed potential is also benchmarked against other potentials available in literature. It shows particularly good agreement with the DFT obtained mixing enthalpy of the random alloy, the formation energy of intermetallics and experimental excess vibrational entropy and phase diagram. In addition, DFT calculated point-defect properties, both interstitial and substitutional, are well reproduced, as is the screw dislocation core structure. As a first validation of the potential, we study the precipitation hardening of Fe-Cr alloys via static simulations of the interaction between Cr precipitates and screw dislocations. It is concluded that the description of the dislocation core modification near a precipitate might have a significant influence on the interaction mechanisms observed in dynamic simulations.

  2. Structural evolution of Ni-20Cr alloy during ball milling of elemental powders

    Energy Technology Data Exchange (ETDEWEB)

    Lopez B, I.; Trapaga M, L. G. [IPN, Centro de Investigacion y de Estudios Avanzados, Unidad Queretaro, Libramiento Norponiente No. 2000, Juriquilla, 76230 Queretaro (Mexico); Martinez F, E. [Centro de Investigacion e Innovacion Tecnologica, Cerrada de Cecati s/n, Col. Santa Catarina Azcapotzalco, 02250 Mexico D. F. (Mexico); Zoz, H., E-mail: israelbaez@gmail.co [Zoz GmbH, D-57482, Wenden (Germany)

    2011-07-01

    The ball milling (B M) of blended Ni and Cr elemental powders was carried out in a Simoloyer performing on high-energy scale mode at maximum production to obtain a nano structured Ni-20Cr alloy. The phase transformations and structural changes occurring during mechanical alloying were investigated by X-ray diffraction (XRD) and optical microscopy (Om). A gradual solid solubility of Cr and the subsequent formation of crystalline metastable solid solutions described in terms of the Avrami-Ero fe ev kinetics model were calculated. The XRD analysis of the structure indicates that cumulative lattice strain contributes to the driving force for solid solution between Ni and Cr during B M. Microstructure evolution has shown, additionally to the lamellar length refinement commonly observed, the folding of lamellae in the final processing stage. Om observations revealed that the lamellar spacing of Ni rich zones reaches a steady value near 500 nm and almost disappears after 30 h of milling. (Author)

  3. Chromium isotope variations (δ53/52Cr) in mantle-derived sources and their weathering products: Implications for environmental studies and the evolution of δ53/52Cr in the Earth’s mantle over geologic time

    Science.gov (United States)

    Farkaš, Juraj; Chrastný, Vladislav; Novák, Martin; Čadkova, Eva; Pašava, Jan; Chakrabarti, Ramananda; Jacobsen, Stein B.; Ackerman, Lukáš; Bullen, Thomas D.

    2013-12-01

    Ignition (LOI) parameter, which determines the amount of structurally bound water (OH/H2O) present in secondary hydrated minerals like serpentine. Overall, we observed that altered ultramafic rocks that yielded the highest LOI values, and the lowest amounts of fluid mobile elements, also yielded the heaviest δ53/52Cr signatures. Therefore, we conclude that secondary alteration (i.e., hydration, serpentinization) of ultramafic rocks in near-surface oxidative environments tend to shift the bulk Cr isotope composition of the weathered products to isotopically heavier values, pointing to a dynamic redox cycling of Cr in the Earth’s crustal and near-surface environments. Hence, if validated by future studies, this would suggest that Cr isotopes could be used to trace the recycling of altered oceanic lithosphere through subduction zones, and to detect the sources of dehydrated and previously serpentinized oceanic crust carrying ‘heavy’ δ53/52Cr signatures in island arc systems. Finally, the fact that the geogenic Cr sources may locally exhibit anomalous (non-canonical) δ53/52Cr signatures has also implications for environmental studies that use δ53/52Cr as a tracer to quantify the amount of the hexavalent Cr reduction in waters.

  4. Molasses as an efficient low-cost carbon source for biological Cr(VI) removal

    Energy Technology Data Exchange (ETDEWEB)

    Michailides, Michail K. [Department of Environmental and Natural Resources Management, University of Patras, 2 G. Seferi Str., GR-30100 Agrinio (Greece); Tekerlekopoulou, Athanasia G., E-mail: atekerle@upatras.gr [Department of Environmental and Natural Resources Management, University of Patras, 2 G. Seferi Str., GR-30100 Agrinio (Greece); Akratos, Christos S.; Coles, Sandra [Department of Environmental and Natural Resources Management, University of Patras, 2 G. Seferi Str., GR-30100 Agrinio (Greece); Pavlou, Stavros [Institute of Chemical Engineering Sciences (FORTH/ICE-HT), Stadiou Str., Platani, P.O. Box 1414, GR-26504 Patras (Greece); Department of Chemical Engineering, University of Patras, GR-26504 Patras (Greece); Vayenas, Dimitrios V. [Department of Environmental and Natural Resources Management, University of Patras, 2 G. Seferi Str., GR-30100 Agrinio (Greece); Institute of Chemical Engineering Sciences (FORTH/ICE-HT), Stadiou Str., Platani, P.O. Box 1414, GR-26504 Patras (Greece)

    2015-01-08

    Highlights: • Suspended and attached growth reactors were examined for Cr(VI) bio-reduction. • Molasses was proved an efficient and very low cost carbon source. • Molasses was more efficient than sugar in enhancing Cr(VI) reduction. • SBR with recirculation was the most proper operating mode. - Abstract: In the present study, indigenous microorganisms from industrial sludge were used to reduce the activity of Cr(VI). Molasses, a by-product of sugar processing, was selected as the carbon source (instead of sugar used in a previous work) as it is a low-cost energy source for bioprocesses. Initially, experiments were carried out in suspended growth batch reactors for Cr(VI) concentrations of 1.5–110 mg/L. The time required for complete Cr(VI) reduction increased with initial Cr(VI) concentration. Initial molasses concentration was also found to influence the Cr(VI) reduction rate. The optimal concentration for all initial Cr(VI) concentrations tested was 0.8 gC/L. Experiments were also carried out in packed-bed reactors. Three different operating modes were used to investigate the optimal performance and efficiency of the filter, i.e. batch, continuous and SBR with recirculation. The latter mode with a recirculation rate of 0.5 L/min lead to significantly high Cr(VI) reduction rates (up to 135 g/m{sup 2} d). The results of this work were compared with those of a similar work using sugar as the carbon source and indicate that molasses could prove a feasible technological solution to a serious environmental problem.

  5. The Effect of Radiator on CR-39 Registration of Fast Neutrons

    International Nuclear Information System (INIS)

    El-Badrya, B.A.; Hegazya, T.M.; Morsya, A.A.; Zaki, M.F.

    2008-01-01

    Three different configurations of a personal neutron dosimeter using CR-39 plastic detector were placed in Plastiplast pouch composed from inside to outside of Aluminum ( 27 Al, 40 Ξ m), polyethylene (PE, 20 Ξ m), Cellulose Nitrate (CN, 40 Ξ m). One dosimeter was composed of a CR-39 detector and a PE radiator (1 mm thick), another of two CR-39 detectors with one serving as radiator, and the other of CR-39 alone (without radiator). These dosimeters have been irradiated with fast neutrons of average energy 4.5 MeV with neutron fluence ranging from 5.5 x 10 6 to 0.5 x 10 8 cm - 2 emitted from 241 Am-Be neutron source. The polymeric materials have been chosen on the basis of their hydrogen contents, which are as followed: CR-39, 48%, Polyethylene, 66.7% and CN, 32% by atomic ratio to produce protons via (n, p) elastic scattering with hydrogen and increasing the detection efficiency of CR-39. After irradiation, the dose equivalent response of the detectors has been studied by using conventional etching for two periods, 6h and 8h for these configurations. The thicknesses and compositions of the radiators are chosen so as to suppress the CR-39 response below 4 MeV by preventing the recoils of hydrogen nuclei, out of the hydrogen-rich radiators (PE, CR-39), from reaching the post-etch surface of the detector. Track counting was performed using an automated system. It was found that the dosemeter responses were linear as a function of a neutron equivalent dose and that the CR-39 detector has the same response with radiator or without radiator and thus appears as a promising fast neutron dosimeter. The results are discussed and compared with the literature

  6. Quasicrystalline and crystalline phases in Al65Cu20(Fe, Cr)15 alloys

    International Nuclear Information System (INIS)

    Liu, W.; Koester, U.; Mueller, F.; Rosenberg, M.

    1992-01-01

    Two types of icosahedral quasicrystals are observed in Al 65 Cu 20 Fe 15-x Cr x (0 ≤ x ≤ 15) alloys, the face-centred AlCuFe-type icosahedral phase with dissoluted Cr and the primitive AlCuCr-type icosahedral phase with dissoluted Fe. In the vicinity of Al 65 Cu 20 Fe 8 Cr 7 a stable decagonal phase (a=0.45 nm and c=1.23 nm) forms competitively with the icosahedral quasicrystals. All these three quasicrystalline phases can be regarded as Hume-Rothery phases stabilized by the energy band factor. The density is measured to be 4.57, 4.44, and 4.11 g/cm 3 for the icosahedral Al 65 Cu 20 Fe 15 , the decagonal Al 65 Cu 20 Fe 8 Cr 7 , and the icosahedral Al 65 Cu 20 Cr 15 alloys, respectively. Depending on the composition in the range between Al 65 Cu 20 Fe 8 Cr 7 and Al 65 Cu 20 Cr 15 , several crystalline phases are observed during the transormation of the AlCuCr-type icosahedral phase: the 1/1-3/2-type orthorhombic (o) and the 1/0-3/2-type tetragonal (t) approximants of the decagonal phase, a hexagonal (h) phase, as well as a long-range vacancy ordered τ 3 -phase derived from a CsCl-type structure with a=0.2923 nm. The structures of all the crystalline phases are closely related to those of the icosahedral (i) and decagonal (d) quasicrystals, which leads to a definite orientation relationship as follows: i5 parallel d10 parallel o[100] parallel t[100] parallel h[001] parallel τ 3 [110]. (orig.)

  7. Elaboration, characterization of CrN- based coatings

    International Nuclear Information System (INIS)

    Tlili, B.; Nouveau, C.; Guillemot, G.

    2011-01-01

    Cr, CrN and CrAlN monolayers were synthesized by RF dual magnetron sputtering on AISI4140 steel and silicon substrates at 200 deg. C. Multilayers coatings based on the three mono-layers such as CrN/CrAlN and Cr/CrN/CrAlN were also synthesized only on Si. The physico-chemical and mechanical properties of the layers were determined by AFM, SEM+WDS, stress, roughness and nanoindentation measurements. The influence of the thickness on the mechanical properties of the monolayers stresses has been studied and as a consequence we compared the mono and multilayers stress state.

  8. Microstructures Evolution and Micromechanics Features of Ni-Cr-Si Coatings Deposited on Copper by Laser Cladding

    Directory of Open Access Journals (Sweden)

    Peilei Zhang

    2018-05-01

    Full Text Available Three Ni-Cr-Si coatings were synthesized on the surface of copper by laser cladding. The microstructures of the coatings were characterized by optical microscopy (OM, X-ray diffraction (XRD, and scanning electron microscopy (SEM with an energy dispersive spectrometer (EDS. According to the analysis results of phase compositions, Gibbs free energy change and microstructures, the phases of three coatings appeared were Cr3Si+γ-Ni+Cuss (Coating 1, Ni-26Cr-29Si, Cr6Ni16Si7+Ni2Si+Cuss (Coating 2, Ni-10Cr-30Si and Cr3Ni5Si2+Cr2Ni3+Cuss (Coating 3, Ni-29Cr-16Si. The crystal growth in the solidification process was analyzed with a modified model, which is a combination of Kurz-Giovanola-Trivedi (KGT and Lipton-Kurz-Trivedi (LKT models. The dendrite tip undercooling in Coating 2 was higher than those of Coating 1 and Coating 3. Well-developed dendrites were found in Coating 2. A modification of Hunt’s model was adopted to describe the morphological differences in the three coatings. The results show that Coating 1 was in the equiaxed dendrite region, while Coatings 2 and 3 were in the columnar dendrite region. The average friction coefficients of the three coatings were 0.45, 0.5 and 0.4, respectively. Obvious plastic deformation could be found in the subsurface zone of Coatings 2 and 3.

  9. Surface stabilized GMR nanorods of silver coated CrO2 synthesized via a polymer complex at ambient pressure

    International Nuclear Information System (INIS)

    Biswas, S.; Singh, G.P.; Ram, S.; Fecht, H.-J.

    2013-01-01

    Stable anisotropic nanorods of surface modified CrO 2 (∼18 nm diameter) with a correlated diamagnetic layer (2–3 nm thickness) of silver efficiently tailors useful magnetic and magnetoresistance (MR) properties. Essentially, it involves a core-shell structure that is developed by displacing part of Cr 4+ ions by Ag atoms on the CrO 2 surface (topotactic surface layer) via an etching reaction of a CrO 2 -polymer complex with Ag + ions in hot water followed by heating the dried sample at 300–400 °C in air. The stable Ag-layer so obtained in the form of a shell protects CrO 2 such that it no longer converts to Cr 2 O 3 in ambient pressure during the processing. X-ray diffractogram of the Rutile type tetragonal CrO 2 structure (lattice parameters a=0.4429 nm and c=0.2950 nm) includes weak peaks of a minority phase of an fcc-Ag (a=0.4086 nm). The silver surface layer, which manifests itself in a doublet of the 3d 5/2 and 3d 3/2 X-ray photoelectron bands of binding energies 368.46 eV and 374.48 eV, respectively, suppresses almost all Cr bands to appear in a measurable intensity. The sample exhibits a distinctly enhanced MR-value, e.g., (−) 7.6% at 77 K, than reported values in compacted CrO 2 powders or composites. Such a large MR-value in the Coulomb blockade regime ( 2 nanorods. - Highlights: • Synthesis and structural studies of a novel GMR material of Ag coated CrO 2 . • Tailoring useful GMR property in CrO 2 nanorods of controlled shape and anisotropy. • Enhanced GMR is explained in correlation to the surface structure of CrO 2 nanorods

  10. Crystallization kinetics and magnetic properties of FeSiCr amorphous alloy powder cores

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Hu-ping [School of Logistics Engineering, Wuhan University of Technology, Wuhan 430063 (China); Wang, Ru-wu, E-mail: ruwuwang@hotmail.com [National Engineering Research Center For Silicon Steel, Wuhan 430080 (China); College of Materials Science and Metallurgical Engineering, Wuhan University of Science and Technology, Wuhan 430081 (China); Wei, Ding [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China); Zeng, Chun [National Engineering Research Center For Silicon Steel, Wuhan 430080 (China)

    2015-07-01

    The crystallization kinetics of FeSiCr amorphous alloy, characterized by the crystallization activation energy, Avrami exponent and frequency factor, was studied by non-isothermal differential scanning calorimetric (DSC) measurements. The crystallization activation energy and frequency factor of amorphous alloy calculated from Augis–Bennett model were 476 kJ/mol and 5.5×10{sup 18} s{sup −1}, respectively. The Avrami exponent n was calculated to be 2.2 from the Johnson–Mehl–Avrami (JMA) equation. Toroid-shaped Fe-base amorphous powder cores were prepared from the commercial FeSiCr amorphous alloy powder and subsequent cold pressing using binder and insulation. The characteristics of FeSiCr amorphous alloy powder and the effects of compaction pressure and insulation content on the magnetic properties, i.e., effective permeability μ{sub e}, quality factor Q and DC-bias properties of FeSiCr amorphous alloy powder cores, were investigated. The FeSiCr amorphous alloy powder cores exhibit a high value of quality factor and a stable permeability in the frequency range up to 1 MHz, showing superior DC-bias properties with a “percent permeability” of more than 82% at H=100 Oe. - Highlights: • The crystallization kinetics of FeSiCr amorphous alloy was investigated. • The FeSiCr powder cores exhibit a high value of Q and a stable permeability. • The FeSiCr powder cores exhibit superior DC-bias properties.

  11. Characterization of laboratory and industrial CrN/CrCN/diamond-like carbon coatings

    Energy Technology Data Exchange (ETDEWEB)

    Silva, F.J.G., E-mail: francisco.silva@eu.ipp.pt [Departamento de Engenharia Mecânica do Instituto Superior de Engenharia do Porto do Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4200-072 Porto (Portugal); Martinho, R.P. [Departamento de Engenharia da Escola Superior de Estudos Industriais e de Gestão do Instituto Politécnico do Porto, Rua D. Sancho I, 981, 4480-876 Vila do Conde (Portugal); Baptista, A.P.M. [Departamento de Engenharia Mecânica da Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, s/n, 4200-465 Porto (Portugal)

    2014-01-01

    This work reports on laboratorial and experimental wear behaviour studies about a multi-layered film deposited by PVD (Physical Vapour Deposition) unbalanced magnetron sputtering. The film consists of three different layers: CrN in the bottom, CrCN as intermediate layer and DLC (diamond-like carbon) on the top. Film characterization was done using techniques such as Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, Atomic Force Microscopy and X-ray diffraction. Scratch-tests, nanoindentation analysis and ball-cratering wear tests were used in order to measure the adhesion critical load, hardness and wear coefficient, respectively. Experimental tests were developed letting one to realise the suitability of this film for mould cavities used on injection moulding machines that produce automotive parts in polypropylene reinforced with 30% (wt.) glass fibres, because this composite material performs severe abrasion on injection moulding which brings important challenges to surface wear resistance. Experimental tests revealed that, after 135,000 injection cycles, multi-layer coating improved significantly the performance previously revealed by uncoated samples. The good results achieved by this film can be partially assigned to DLC top layer due to its low friction coefficient. This paper discusses these results, comparing them with some other PVD coatings already tested in the same conditions. - Highlights: • This coating presents a very good adhesion to the P20 steel substrate. • Surface wear performance is largely improved by the use of this coating. • Coating wear resistance is about 58.2 times higher than the uncoated substrate. • This film presents high suitability for application in mould cavities.

  12. Inhibited Aluminization of an ODS FeCr Alloy

    International Nuclear Information System (INIS)

    Vande Put Ep Rouaix, Aurelie; Pint, Bruce A.

    2012-01-01

    Aluminide coatings are of interest for fusion energy applications both for compatibility with liquid Pb-Li and to form an alumina layer that acts as a tritium permeation barrier. Oxide dispersion strengthened (ODS) ferritic steels are a structural material candidate for commercial reactor concepts expected to operate above 600 C. Aluminizing was conducted in a laboratory scale chemical vapor deposition reactor using accepted conditions for coating Fe- and Ni-base alloys. However, the measured mass gains on the current batch of ODS Fe-14Cr were extremely low compared to other conventional and ODS alloys. After aluminizing at two different Al activities at 900 C and at 1100 C, characterization showed that the ODS Fe-14Cr specimens formed a dense, primarily AlN layer that prevented Al uptake. This alloy batch contained a higher (> 5000 ppma) N content than the other alloys coated and this is the most likely reason for the inhibited aluminization. Other factors such as the high O content, small (∼ 140 nm) grain size and Y-Ti oxide nano-clusters in ODS Fe-14Cr also could have contributed to the observed behavior. Examples of typical aluminide coatings formed on conventional and ODS Fe- and Ni-base alloys are shown for comparison.

  13. Fe, Cr, Ni, Cu, Mg, Al, Ti, and S contents in plants and soil of heaps of nickel smelting works

    Energy Technology Data Exchange (ETDEWEB)

    Banasova, V; Hajduk, J

    1977-01-01

    The writers established the Fe, Ce, Cr, Ni, Ca, Mg, Al, Ti and S contents in the neopedon of heaps piling up from processing of nickel ore as well as in the plants: Cardaria draba, Salsola cali, Agropyrum repens, Bromus erectus, Calamagrostis epigeios, Cynodon dactylon and Matricaria inodora, growing on such heaps. Ca, Mg and S contents were found to be higher in dicotyledons and Fe, Al, Ti, Ni and Cr contents higher in monocotyledons. The analyzed dicotyledons appeared to be concentrators of Ca and S. Highest Fe, Al, Ti, Ni and Cr contents were found in individuals of the species Agropyrum repens. The neopedon as well as the plants had extraordinarily high Cr concentrations. The species Salsola cali has been found to possess an unusually higher affinity to the dump substrate after processing of nickel ore and to be a concentrator of Mg. 16 references, 1 table.

  14. Effects of La{sub 2}O{sub 3} on microstructure and wear properties of laser clad {gamma}/Cr{sub 7}C{sub 3}/TiC composite coatings on TiAl intermatallic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xiubo [Laboratory for Laser Intelligent Manufacturing, Institute of Mechanics, Chinese Academy of Sciences, 15 Beisihuanxi Road, Beijing 100080 (China) and School of Materials and Chemical Engineering, Zhongyuan Institute of Technology, 41 Zhongyuan Western Road, Zhengzhou 450007, Henan Province (China)]. E-mail: liubobo0828@yahoo.com.cn; Yu Rongli [School of Materials Science and Engineering, Beihang University, 37 Xueyuan Road, Beijing 100083 (China)

    2007-02-15

    The effects of La{sub 2}O{sub 3} addition on the microstructure and wear properties of laser clad {gamma}/Cr{sub 7}C{sub 3}/TiC composite coatings on {gamma}-TiAl intermetallic alloy substrates with NiCr-Cr{sub 3}C{sub 2} precursor mixed powders have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy-dispersive spectrometer (EDS) and block-on-ring wear tests. The responding wear mechanisms are discussed in detail. The results are compared with that for composite coating without La{sub 2}O{sub 3}. The comparison indicates that no evident new crystallographic phases are formed except a rapidly solidified microstructure consisting of the primary hard Cr{sub 7}C{sub 3} and TiC carbides and the {gamma}/Cr{sub 7}C{sub 3} eutectics distributed in the tough {gamma} nickel solid solution matrix. Good finishing coatings can be achieved under a proper amount of La{sub 2}O{sub 3}-addition and a suitable laser processing parameters. The additions of rare-earth oxide La{sub 2}O{sub 3} can refine and purify the microstructure of coatings, relatively decrease the volume fraction of primary blocky Cr{sub 7}C{sub 3} to Cr{sub 7}C{sub 3}/{gamma} eutectics, reduce the dilution of clad material from base alloy and increase the microhardness of the coatings. When the addition of La{sub 2}O{sub 3} is approximately 4 wt.%, the laser clad composite coating possesses the highest hardness and toughness. The composite coating with 4 wt.%La{sub 2}O{sub 3} addition can result the best enhancement of wear resistance of about 30%. However, too less or excessive addition amount of La{sub 2}O{sub 3} have no better influence on wear resistance of the composite coating.

  15. The Experience Elicited by Hallucinogens Presents the Highest Similarity to Dreaming within a Large Database of Psychoactive Substance Reports

    Science.gov (United States)

    Sanz, Camila; Zamberlan, Federico; Erowid, Earth; Erowid, Fire; Tagliazucchi, Enzo

    2018-01-01

    Ever since the modern rediscovery of psychedelic substances by Western society, several authors have independently proposed that their effects bear a high resemblance to the dreams and dreamlike experiences occurring naturally during the sleep-wake cycle. Recent studies in humans have provided neurophysiological evidence supporting this hypothesis. However, a rigorous comparative analysis of the phenomenology (“what it feels like” to experience these states) is currently lacking. We investigated the semantic similarity between a large number of subjective reports of psychoactive substances and reports of high/low lucidity dreams, and found that the highest-ranking substance in terms of the similarity to high lucidity dreams was the serotonergic psychedelic lysergic acid diethylamide (LSD), whereas the highest-ranking in terms of the similarity to dreams of low lucidity were plants of the Datura genus, rich in deliriant tropane alkaloids. Conversely, sedatives, stimulants, antipsychotics, and antidepressants comprised most of the lowest-ranking substances. An analysis of the most frequent words in the subjective reports of dreams and hallucinogens revealed that terms associated with perception (“see,” “visual,” “face,” “reality,” “color”), emotion (“fear”), setting (“outside,” “inside,” “street,” “front,” “behind”) and relatives (“mom,” “dad,” “brother,” “parent,” “family”) were the most prevalent across both experiences. In summary, we applied novel quantitative analyses to a large volume of empirical data to confirm the hypothesis that, among all psychoactive substances, hallucinogen drugs elicit experiences with the highest semantic similarity to those of dreams. Our results and the associated methodological developments open the way to study the comparative phenomenology of different altered states of consciousness and its relationship with non-invasive measurements of brain physiology. PMID

  16. Relation of average and highest solvent vapor concentrations in workplaces in small to medium enterprises and large enterprises.

    Science.gov (United States)

    Ukai, Hirohiko; Ohashi, Fumiko; Samoto, Hajime; Fukui, Yoshinari; Okamoto, Satoru; Moriguchi, Jiro; Ezaki, Takafumi; Takada, Shiro; Ikeda, Masayuki

    2006-04-01

    The present study was initiated to examine the relationship between the workplace concentrations and the estimated highest concentrations in solvent workplaces (SWPs), with special references to enterprise size and types of solvent work. Results of survey conducted in 1010 SWPs in 156 enterprises were taken as a database. Workplace air was sampled at > or = 5 crosses in each SWP following a grid sampling strategy. An additional air was grab-sampled at the site where the worker's exposure was estimated to be highest (estimated highest concentration or EHC). The samples were analyzed for 47 solvents designated by regulation, and solvent concentrations in each sample were summed up by use of additiveness formula. From the workplace concentrations at > or = 5 points, geometric mean and geometric standard deviations were calculated as the representative workplace concentration (RWC) and the indicator of variation in workplace concentration (VWC). Comparison between RWC and EHC in the total of 1010 SWPs showed that EHC was 1.2 (in large enterprises with>300 employees) to 1.7 times [in small to medium (SM) enterprises with enterprises and large enterprises, both RWC and EHC were significantly higher in SM enterprises than in large enterprises. Further comparison by types of solvent work showed that the difference was more marked in printing, surface coating and degreasing/cleaning/wiping SWPs, whereas it was less remarkable in painting SWPs and essentially nil in testing/research laboratories. In conclusion, the present observation as discussed in reference to previous publications suggests that RWC, EHC and the ratio of EHC/WRC varies substantially among different types of solvent work as well as enterprise size, and are typically higher in printing SWPs in SM enterprises.

  17. The Experience Elicited by Hallucinogens Presents the Highest Similarity to Dreaming within a Large Database of Psychoactive Substance Reports

    Directory of Open Access Journals (Sweden)

    Camila Sanz

    2018-01-01

    Full Text Available Ever since the modern rediscovery of psychedelic substances by Western society, several authors have independently proposed that their effects bear a high resemblance to the dreams and dreamlike experiences occurring naturally during the sleep-wake cycle. Recent studies in humans have provided neurophysiological evidence supporting this hypothesis. However, a rigorous comparative analysis of the phenomenology (“what it feels like” to experience these states is currently lacking. We investigated the semantic similarity between a large number of subjective reports of psychoactive substances and reports of high/low lucidity dreams, and found that the highest-ranking substance in terms of the similarity to high lucidity dreams was the serotonergic psychedelic lysergic acid diethylamide (LSD, whereas the highest-ranking in terms of the similarity to dreams of low lucidity were plants of the Datura genus, rich in deliriant tropane alkaloids. Conversely, sedatives, stimulants, antipsychotics, and antidepressants comprised most of the lowest-ranking substances. An analysis of the most frequent words in the subjective reports of dreams and hallucinogens revealed that terms associated with perception (“see,” “visual,” “face,” “reality,” “color”, emotion (“fear”, setting (“outside,” “inside,” “street,” “front,” “behind” and relatives (“mom,” “dad,” “brother,” “parent,” “family” were the most prevalent across both experiences. In summary, we applied novel quantitative analyses to a large volume of empirical data to confirm the hypothesis that, among all psychoactive substances, hallucinogen drugs elicit experiences with the highest semantic similarity to those of dreams. Our results and the associated methodological developments open the way to study the comparative phenomenology of different altered states of consciousness and its relationship with non-invasive measurements of brain

  18. Influence of a niobium coating on sulfidation resistance of FeCr and FeCrY alloys; Influencia de um revestimento de niobio sobre a resistencia a sulfetacao das ligas FeCr e FeCrY

    Energy Technology Data Exchange (ETDEWEB)

    Geribola, Gulherme Altomari

    2014-07-01

    Niobium and niobium based alloys are currently used in many industrial applications because they offer excellent resistance to degradation in various corrosive environments. These media include gaseous atmospheres at high temperatures such as those found in existing coal gasifying plants in power plants for energy generation. These atmospheres are complex gas mixtures that contain sulfur and oxygen, among other compounds. Sulphides are thermodynamically less stable, have lower melting points and often have larger deviations from stoichiometry compared to the corresponding oxides. Although there are studies regarding the use of refractory metals in high temperature sulphidizing atmospheres, the use of niobium compounds has not been adequately evaluated and there is very little studies available in the literature about its use as a protective coating. The aim of this study was to evaluate the effect of a niobium film, deposited by magnetron sputtering on the isothermal sulphidation behavior of Fe-20Cr and Fe-20Cr-1Y alloys. The sulphidation tests were carried out at 500, 600 and 700 deg C for 2h in H{sub 2}/2% H2S atmosphere. The sulphidation resistance was determined by mass gain per unit area. The sulphidation behavior of the coated and uncoated alloys was similar at 500 deg C, and none of the alloys scaled. At 700 deg C FeCr alloy scaled in the form of a fine powder, while the reaction product formed on the alloy FeCrY scaled in the form of plates. The effect of niobium became pronounced at 700 deg C. The reaction product layer formed on the coated alloy was thinner and more plastic than that formed on the uncoated alloy. The mass gain per unit area of the coated alloys decreased significantly and they did not scaled. (author)

  19. The Physikalisch-Technische Bundesanstalt PTB (physical-technical Federal institution) - research institute and highest technical authority

    International Nuclear Information System (INIS)

    Klages, H.

    1976-01-01

    The PTB Braunschweig and Berlin is a Federal institution for the natural sciences and engineering and the highest technical authority for measurements. It is subject to the directions of the Federal Ministry for Economic Affairs. Its main tasks are representation, maintenance and development of physical units and, in connection with this, research, examinations, and granting permissions for calibration measuring equipment, as well as examinations of building types and permissions. The types of measuring equipment are represented. Many examinations are carried out on a voluntary basis. The advisory activities and the PTB's publications are also reported on. An organizational plan informs of the structure of the PTB. (orig.) [de

  20. The Licancabur Project: Exploring the Limits of Life in the Highest Lake on Earth as an Analog to Martian Paleolakes

    Science.gov (United States)

    Cabrol, N. A.; Grin, E. A.; McKay, C. P.; Friedmann, I.; Diaz, G. Chong; Demergasso, C.; Kisse, K.; Grigorszky, I.; Friedmann, R. Ocampo; Hock, A.

    2003-01-01

    The Licancabur volcano (6017 m) hosts the highest and one of the least explored lakes in the world in its summit crater. It is located 22 deg.50 min. South / 67 deg.53 min. West at the boundary of Chile and Bolivia in the High-Andes. In a freezing environment, the lake located in volcano-tectonic environment combines low-oxygen, low atmospheric pressure due to altitude, and high-UV radiation (see table). However, its bottom water temperature remains above 0 C year-round. These conditions make Licancabur a unique analog to Martian paleolakes considered high-priority sites for the search for life on Mars.

  1. Potential need for re-definition of the highest priority recovery action in the Krsko SAG-1

    International Nuclear Information System (INIS)

    Bilic Zabric, T.; Basic, I.

    2005-01-01

    Replacement of old SG (Steam Generators) [7] and the characteristic of new ones throws the question of proper accident management strategy, which leans on philosophy that repair and recovery actions have first priority. In the current NPP Krsko SAMGs (Severe Accident Management Guidelines), water supply to the SG has priority over re-injection water into the core. NPP Krsko reconsidered the highest priority of SAG-1 (inject water to the SG), against the WOG (Westinghouse Owners Group) generic approach (inject water into the core) and potential revision of Severe Accident Phenomenology Evaluations using MAAP (Modular accident Analysis Program) 4.0.5 code. (author)

  2. Plastic deformation behavior of Fe–Co–B–Si–Nb–Cr bulk metallic glasses under nanoindentation

    International Nuclear Information System (INIS)

    Kim, J.T.; Hong, S.H.; Lee, C.H.; Park, J.M.; Kim, T.W.; Lee, W.H.; Yim, H.I.; Kim, K.B.

    2014-01-01

    Highlights: • Additional Cr modulation of atomic structure of Fe-Co-B-Si-Nb BMGs. • An amount of free volume characterized by a combination of nanoindentation and AFM. • Free volume determined by height measurement of AFM after nanoindentation. -- Abstract: In this work, we investigate the effect of Cr addition on thermal properties and indentation behavior of Fe 52 Co 20−x B 20 Si 4 Nb 4 Cr x alloys with x = 0, 1, 3 and 5 at.%, respectively. Among all studied alloys, the Fe 52 Co 17 B 20 Si 4 Nb 4 Cr 3 bulk metallic glass (BMG) exhibits the highest thermal stability with large supercooled liquid region of 40 K and the pronounced plastic deformation features which is serrated flow (pop-in event) and significant pile-up of materials around indents. This demonstrates that the appropriate addition of Cr in Fe-based BMG can induce the internal atomic structure modulation and promote the mechanical softening, which are discussed in terms of free volume concept

  3. Plastic deformation behavior of Fe–Co–B–Si–Nb–Cr bulk metallic glasses under nanoindentation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.T.; Hong, S.H.; Lee, C.H. [HMC, Faculty of Nanotechnology and Advanced Materials Engineering, Sejong University, 98 Gunja-dong, Gwangjin-gu, Seoul 143-747 (Korea, Republic of); Park, J.M., E-mail: jinman_park@hotmail.com [Materials Research Center, Samsung Advanced Institute of Technology (SAIT), San 14-1, Nongseo-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-712 (Korea, Republic of); Kim, T.W.; Lee, W.H. [HMC, Faculty of Nanotechnology and Advanced Materials Engineering, Sejong University, 98 Gunja-dong, Gwangjin-gu, Seoul 143-747 (Korea, Republic of); Yim, H.I. [Department of Physics, Sookmyung Women’s University, Hyochangwongil 52, Yongsan-ku, Seoul 140-742 (Korea, Republic of); Kim, K.B., E-mail: kbkim@sejong.ac.kr [HMC, Faculty of Nanotechnology and Advanced Materials Engineering, Sejong University, 98 Gunja-dong, Gwangjin-gu, Seoul 143-747 (Korea, Republic of)

    2014-02-25

    Highlights: • Additional Cr modulation of atomic structure of Fe-Co-B-Si-Nb BMGs. • An amount of free volume characterized by a combination of nanoindentation and AFM. • Free volume determined by height measurement of AFM after nanoindentation. -- Abstract: In this work, we investigate the effect of Cr addition on thermal properties and indentation behavior of Fe{sub 52}Co{sub 20−x}B{sub 20}Si{sub 4}Nb{sub 4}Cr{sub x} alloys with x = 0, 1, 3 and 5 at.%, respectively. Among all studied alloys, the Fe{sub 52}Co{sub 17}B{sub 20}Si{sub 4}Nb{sub 4}Cr{sub 3} bulk metallic glass (BMG) exhibits the highest thermal stability with large supercooled liquid region of 40 K and the pronounced plastic deformation features which is serrated flow (pop-in event) and significant pile-up of materials around indents. This demonstrates that the appropriate addition of Cr in Fe-based BMG can induce the internal atomic structure modulation and promote the mechanical softening, which are discussed in terms of free volume concept.

  4. Mathematical models applied to the Cr(III) and Cr(VI) breakthrough curves.

    Science.gov (United States)

    Ramirez C, Margarita; Pereira da Silva, Mônica; Ferreira L, Selma G; Vasco E, Oscar

    2007-07-19

    Trivalent and hexavalent chromium continuous biosorption was studied using residual brewer Saccharomyces cerevisiae immobilized in volcanic rock. The columns used in the process had a diameter of 4.5 cm and a length of 140 cm, working at an inlet flow rate of 15 mL/min. Breakthrough curves were used to study the yeast biosorption behavior in the process. The saturation time (ts) was 21 and 45 h for Cr(III) and Cr(VI), respectively, and a breakthrough time (tb) of 4 h for Cr(III) and 5 h for Cr(VI). The uptake capacity of the biosorbent for Cr(III) and Cr(VI) were 48 and 60 mg/g, respectively. Two non-diffusional mathematical models with parameters t0 and sigma were used to adjust the experimental data obtained. Microsoft Excel tools were used for the mathematical solution of the two parameters used.

  5. The lattice distortion effect for zinc-blende CrAs and CrSb

    International Nuclear Information System (INIS)

    Yamana, Keita; Geshi, Masaaki; Tsukamoto, Hidekazu; Uchida, Ichiro; Shirai, Masafumi; Kusakabe, Koichi; Suzuki, Naoshi

    2004-01-01

    We investigated the stability of the ferromagnetism of CrAs and CrSb in the zinc-blende structure against the lattice distortion, systematically. A calculation within the generalized gradient approximation using a full potential linearized augmented plane wave method was performed. We compared the ferromagnetic state and the antiferromagnetic state assuming tetragonal distortion with the lattice constants a and c changing independently and determined the spin polarization ratio in the ferromagnetic phase. The result shows that complete spin polarization (half-metallic ferromagnetism) remains stable even in the presence of large tetragonal distortion. On the other hand, our calculation shows that two monolayers of CrAs is enough to produce a half-metallic state in the CrAs/GaAs multilayer. Thus, the present result suggests that the half-metallic nature persists in various atomic-scale superlattices made of distorted CrAs or CrSb

  6. Structural, mechanical and corrosion studies of Cr-rich inclusions in 152 cladding of dissimilar metal weld joint

    Science.gov (United States)

    Li, Yifeng; Wang, Jianqiu; Han, En-Hou; Yang, Chengdong

    2018-01-01

    Cr-rich inclusions were discovered in 152 cladding at the inner wall of domestic dissimilar metal weld joint, and their morphologies, microstructures, mechanical properties and corrosion behaviors were systematically characterized by SEM, TEM, nanoindentation and FIB. The results indicate that the Cr-rich inclusions originate from large-size Cr particles in 152 welding electrode flux, and they are 50-150 μm in size in most cases, and there is a continuous transition zone of 2-5 μm in width between the Cr inclusion core and 152 cladding matrix, and the transition zone consists of Ni & Fe-rich dendritic austenite and Cr23C6 and Cr matrix. The transition zone has the highest nanoindentation hardness (7.66 GPa), which is much harder than the inclusion core (5.14 GPa) and 152 cladding (3.71 GPa). In-situ microscopic tensile tests show that cracks initialize preferentially in transition zone, and then propagate into the inclusion core, and creep further into 152 cladding after penetrating the core area. The inclusion core and its transition zone both share similar oxide film structure with nickel-base 152 cladding matrix in simulated primary water, while those two parts present better general corrosion resistance than 152 cladding matrix due to higher Cr concentration.

  7. Assessment of Cr, Ni and Pb Pollution in Rural Agricultural Soils of Tonalite-Trondjhemite Series in Central India.

    Science.gov (United States)

    Shukla, Kriti; Kumar, Bijendra; Agrawal, Rahul; Priyanka, Kumari; Venkatesh, Madavi; Anshumali

    2017-06-01

    Chromium (Cr), nickel (Ni) and lead (Pb) contamination was investigated in wheat cultivated rain-fed and irrigated rural agricultural soils (n = 31) of Tonalite-Trondjhemite Series in Central India. The soil sampling was carried out by using stratified random sampling method. The mean concentrations of Cr, Ni and Pb were 54.8, 38.1 and 68.9 mg/kg, respectively. The average values of enrichment factor (EF), geoaccumulation index (I geo ) and contamination factor (CF) followed the order as: Pb > Ni > Cr. Distribution patterns of soil parent material and weathering processes govern mineral enrichments, irrespective of rainfed or irrigated agricultural practices. Principal component analysis (PCA) showed strong loading of Cr and Ni (PC1) and Pb and clay (PC3). The strong loading on Cr and Ni indicates soils are originating from basic and volcanic rocks in the study area. The strong loading of Pb and clay indicates Pb is strongly adsorbed on clay minerals and Fe-oxides. The cancer risk (CR) index showed negligible carcinogenic risk to the residing population. However, hazard index (HI) values for children exceed the safe limit (HI > 1) for Cr and Pb. Spatial distribution of pollution load index suggest highest pollution in the northeastern part of the district. The study revealed that geogenically enriched soils of the area are suitable for agricultural activities under present conditions.

  8. Treatment of Cr(VI)-containing wastewaters with exopolysaccharide-producing cyanobacteria in pilot flow through and batch systems

    Energy Technology Data Exchange (ETDEWEB)

    Colica, Giovanni; Mecarozzi, Pier Cesare; De Philippis, Roberto [Florence Univ., Firenze (Italy). Dept. of Agricultural Biotechnology

    2010-08-15

    Seven exopolysaccharide-producing cyanobacteria were tested with regard to their capability to remove Cr(VI) from the wastewater of a plating industry. The cyanobacterium which showed, under lab conditions, the most promising features with regard to both Cr(VI) removal (about 12 mg of Cr(VI) removed per gram of dry biomass) and growth characteristics (highest growth rate and simplest culture medium) was Nostoc PCC7936. Furthermore, in lab experiments, it was also found that a HCl pretreatment is essential to abate the concentration of Cr(VI) in solution and that the viability of the biomass is not necessary. Subsequently, three pilot devices were tested, one batch (a dialysis cell) and two flow-through systems (a filter press and a column filled with quartz grain). The best performances were obtained with the filter press, where it was observed a sharp decrease in the concentration of Cr(VI), partly due to the adsorption of the metal by the biomass (about 50%) and partly due to its reduction to Cr(III). The results are discussed in terms of the role played by the different components (biomass and polysaccharide) of the cyanobacterial cultures in the removal of Cr(VI). (orig.)

  9. Particularisation of Alpha Contamination using CR-39 Track Detectors

    International Nuclear Information System (INIS)

    Zakia, M.F.; El-Shaer, Y.H.

    2008-01-01

    Solid-state nuclear track detectors have found wide use in various domains of science and technology, e.g. in environmental experiments. The measurement of alpha activity on sources in an environment, such as air is not easy because of short penetration range of the alpha particles. Furthermore, the measurement of alpha activity by most gas ionization detectors suffers from the high background induced by the accompanying gamma radiation. Solid State Nuclear Track Detectors (SSNTDs) have been used successfully as detecting devices as passive system to detect the alpha contamination different surfaces. This work presents the response of CR-39 (for two types) to alpha particles from two sources, 238 Pu with energy 5 MeV and 241 Am with energy 5.4 MeV. The methods of etching and counting are investigated, along with the achievable linearity, efficiency and reproducibility. The sensitivity to low activity and energy resolution are studied

  10. Proton radiographic characteristics of thin CR-39 detector

    International Nuclear Information System (INIS)

    Waheed, A.; Manzoor, S.; Khan, H.A.; Urlep, I.; Ilic, R.

    1991-01-01

    Two parameters, track registration sensitivity and densitometric response, were measured in radiography with a low energy (∼4.5 MeV) proton beam and a stack of thin (100μm) CR-39 detector foils. The optimum image quality was obtained at a layer removal thickness of about 1 μm. The image obtained under these conditions is characterized by a high track registration sensitivity (∼60%), high image contrast (the maximum value of the net optical density is ∼0.7) and high spatial resolution (∼1 μm). The application of the technique in biomedicine is illustrated by proton radiographs of botanical samples. (author)

  11. Characterization of precipitates in nano structured 14% Cr ODS alloys for fusion application

    International Nuclear Information System (INIS)

    He, P.; Klimenkov, M.; Lindau, R.; Möslang, A.

    2012-01-01

    Highlights: ► We examine Ti influence on microstructure and mechanical properties of ODS steels. ► Ti addition leads to bimodal grain size distribution. ► The formation of Ti oxide and Y–Ti–O particles is observed in Ti-containing steels. ► The best nanoparticle refinement and tensile strength are obtained with 0.3% Ti. ► Ti exhibits adverse effect on the Charpy impact property. - Abstract: Oxide dispersion strengthened (ODS) reduced activation ferritic (RAF) steels, have been considered as promising materials for application in fusion power reactors up to about 750 °C. Four ODS RAF steels, with compositions of Fe–13.5Cr–2W–(0–0.2–0.3–0.4)Ti–0.3Y 2 O 3 (in wt.%) were produced by powder metallurgy technique. For the different Ti-contents, the correlation between microstructure and mechanical properties was analyzed by means of scanning electron microscope (SEM) and transmission electron microscope (TEM) equipped with energy- dispersive X-ray spectrometer (EDX) and electron energy loss spectrometer (EELS). A bimodal grain size distribution was observed in all as-hipped Ti-containing ODS alloys. These alloys consisted of coarse grains typical ranging from 1 μm to 8 μm and fine grains well below 1 μm in diameter. The addition of Ti resulted in the formation of spherical Ti oxides rather than Cr oxides owing to the stronger affinity of Ti. The influence of Ti on particle size refinement was striking and the optimum effect was obtained when adding 0.3% Ti. Generally the hardness increased consistently with increasing in Ti content. The ODS alloying with 0.3% Ti exhibit the highest strength due to the optimum refinement of mean ODS particle size.

  12. Fracture behaviour of the 14Cr ODS steel exposed to helium and liquid lead

    Energy Technology Data Exchange (ETDEWEB)

    Hojna, Anna, E-mail: Anna.Hojna@cvrez.cz [Centrum Vyzkumu Rez s.r.o., UJV Group, Rez 130, 250 68 Husinec (Czech Republic); Di Gabriele, Fosca [Centrum Vyzkumu Rez s.r.o., UJV Group, Rez 130, 250 68 Husinec (Czech Republic); Hadraba, Hynek; Husak, Roman; Kubena, Ivo [CEITEC IPM, Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, 616 62 Brno (Czech Republic); Rozumova, Lucia; Bublikova, Petra; Kalivodova, Jana [Centrum Vyzkumu Rez s.r.o., UJV Group, Rez 130, 250 68 Husinec (Czech Republic); Matejicek, Jiri [Institute of Plasma Physics, Academy of Sciences of the Czech Republic, Za Slovankou 1782/3, 182 00 Praha (Czech Republic)

    2017-07-15

    This work describes the fracture behaviour of the 14Cr ODS steel produced by mechanical alloying process, after high temperature exposures. Small specimens were exposed to helium gas in a furnace at 720 °C for 500 h. Another set of specimens was exposed to flowing liquid lead in the COLONRI II loop at 650 °C for 1000 h. All specimens were tested for the impact and tensile behaviour. The impact test results are compared to other sets of specimens in the as received state and after isothermal annealing at 650 °C for 1000 h. The impact curves of the exposed materials showed positive shifts on the transition temperature. While the upper shelf value did not change in the Pb exposed ODS steel, it significantly increased in the He exposed one. The differences are discussed in terms of surface and subsurface microscopy observation. The embrittlement can be explained as the effect of a slight change in the grain boundary and size distribution combined with the depletion of sub-surface region from alloying elements forming oxide scale on the surface. - Highlights: •We compared the impact energy curves of as received, isothermally aged and He/Pb exposed ODS steel samples. •The highest transition temperature showed the ODS steel exposed to liquid Pb at 650 °C for 1000 h. •We observed the higher tendency of the He exposed samples to crack arrester delamination than the Pb exposed ones. •The crack arrested delamination induced apparent increase of impact energies.

  13. Fe-Cr-Ni system alloys

    International Nuclear Information System (INIS)

    Levin, F.L.

    1986-01-01

    Phase diagram of Fe-Cr-Ni system, which is the basic one for production of corrosion resistant alloys, is considered. Data on corrosion resistance of such alloys are correlated depending on a number of factors: quality and composition of modifying elements, corrosion medium, temperature, alloy structure, mechanical and thermal treatment. Grades of Fe-Ni-Cr alloys are presented, and fields of their application are pointed out

  14. CrN thin films prepared by reactive DC magnetron sputtering for symmetric supercapacitors

    KAUST Repository

    Wei, Binbin

    2016-12-29

    Supercapacitors have been becoming indispensable energy storage devices in micro-electromechanical systems and have been widely studied over the past few decades. Transition metal nitrides with excellent electrical conductivity and superior cycling stability are promising candidates as supercapacitor electrode materials. In this work, we report the fabrication of CrN thin films using reactive DC magnetron sputtering and further their applications for symmetric supercapacitors for the first time. The CrN thin film electrodes fabricated under the deposition pressure of 3.5 Pa show an areal specific capacitance of 12.8 mF cm at 1.0 mA cm and high cycling stability with 92.1% capacitance retention after 20 000 cycles in a 0.5 M HSO electrolyte. Furthermore, our developed CrN//CrN symmetric supercapacitor can deliver a high energy density of 8.2 mW h cm at the power density of 0.7 W cm along with outstanding cycling stability. Thus, the CrN thin films have great potential for application in supercapacitors and other energy storage systems.

  15. Point defect properties of ternary fcc Fe-Cr-Ni alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wróbel, J.S., E-mail: jan.wrobel@inmat.pw.edu.pl [Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland); Nguyen-Manh, D.; Dudarev, S.L. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Kurzydłowski, K.J. [Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland)

    2017-02-15

    Highlights: • Properties of point defects depend on the local atomic environment. • As the degree of chemical order increases, the formation energies increase, too. • Relaxation volumes are larger for the more ordered structures. - Abstract: The properties of point defects in Fe-Cr-Ni alloys are investigated, using density functional theory (DFT), for two alloy compositions, Fe{sub 50}Cr{sub 25}Ni{sub 25} and Fe{sub 55}Cr{sub 15}Ni{sub 30}, assuming various degrees of short-range order. DFT-based Monte Carlo simulations are applied to explore short-range order parameters and generate representative structures of alloys. Chemical potentials for the relevant structures are estimated from the minimum of the substitutional energy at representative atoms sites. Vacancies and 〈1 0 0〉 dumbbells are introduced in the Fe{sub 2}CrNi intermetallic phase as well as in two Fe{sub 55}Cr{sub 15}Ni{sub 30} alloy structures: the disordered and short range-ordered structures, generated using Monte Carlo simulations at 2000 K and 300 K, respectively. Formation energies and relaxation volumes of defects as well as changes of magnetic moments caused by the presence of defects are investigated as functions of the local environment of a defect.

  16. The helium effect at grain boundaries in Fe-Cr alloys: A first-principles study

    Energy Technology Data Exchange (ETDEWEB)

    Zemła, M.R., E-mail: marcin.zemla@wimpw.edu.pl [Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507 Warsaw (Poland); Wróbel, J.S.; Wejrzanowski, T. [Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507 Warsaw (Poland); Nguyen-Manh, D. [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Kurzydłowski, K.J. [Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507 Warsaw (Poland)

    2017-02-15

    Helium is produced in the structural materials in nuclear power plants by nuclear transmutation following neutron irradiation. Since the solubility of helium in all metals is extremely low, helium tends to be trapped at defects such as vacancies, dislocations and grain boundaries, which cause material embrittlement. Density functional theory (DFT) calculations were performed in order to investigate the helium effect at grain boundaries (GBs) in iron-chromium alloys. Both cohesive energy and magnetic properties at symmetric Σ3(1 1 1) and Σ5(2 1 0) tilt Fe GBs are studied in the presence of Cr and He atoms. It is found that the presence of Cr atoms increases cohesive energy, at different He concentrations, and strongly influences magnetic properties at the GBs. The effect of the segregation energy of helium atom as a function of the different positions of Cr atoms located inside/outside a GB has been considered. Results of the present first-principles study enable one to clarify the role of Cr in understanding the helium effect in Fe-Cr-based alloys.

  17. Ductilization of Cr via oxide dispersions

    International Nuclear Information System (INIS)

    Brady, M.P.; Wright, I.G.; Anderson, I.M.; Sikka, V.K.; Ohriner, E.K.; Walls, C.; Westmoreland, G.; Weaver, M.L.

    2001-01-01

    Work by Scruggs et al. in the 1960's demonstrated that up to 20 % tensile ductility could be achieved at room-temperature in sintered and extruded powder metallurgical Cr alloyed with MgO. During sintering, much of the MgO converts to a MgCr 2 O 4 spinel, which was hypothesized to getter nitrogen from the Cr, rendering it ductile. Recent efforts at Oak Ridge National Laboratory (ORNL) have succeeded in duplicating this original effect. Preliminary results suggest that the ductilization mechanism may be more complicated than the simple nitrogen gettering mechanism proposed by Scruggs, as some ductility was observed at room-temperature in Cr-MgO alloys containing nitride precipitates. Results of microstructural characterization and room-temperature mechanical property studies are presented for Cr-6MgO-(0-2.2) Ti wt.% as a function of hot-pressing and extrusion. Possible mechanisms by which the MgO additions may improve the room-temperature ductility of Cr are discussed. (author)

  18. Highest recorded electrical conductivity and microstructure in polypropylene-carbon nanotubes composites and the effect of carbon nanofibers addition

    Science.gov (United States)

    Ramírez-Herrera, C. A.; Pérez-González, J.; Solorza-Feria, O.; Romero-Partida, N.; Flores-Vela, A.; Cabañas-Moreno, J. G.

    2018-04-01

    In the last decade, numerous investigations have been devoted to the preparation of polypropylene-multiwalled carbon nanotubes (PP/MWCNT) nanocomposites having enhanced properties, and in particular, high electrical conductivities (> 1 S cm-1). The present work establishes that the highest electrical conductivity in PP/MWCNT nanocomposites is limited by the amount of nanofiller content which can be incorporated in the polymer matrix, namely, about 20 wt%. This concentration of MWCNT in PP leads to a maximum electrical conductivity slightly lower than 8 S cm-1, but only by assuring an adequate combination of dispersion and spatial distribution of the carbon nanotubes. The realization of such an optimal microstructure depends on the characteristics of the production process of the PP/MWCNT nanocomposites; in our experiments, involving composite fabrication by melt mixing and hot pressing, a second re-processing cycle is shown to increase the electrical conductivity values by up to two orders of magnitude, depending on the MWCNT content of the nanocomposite. A modest increase of the highest electrical conductivity obtained in nanocomposites with 21.5 wt% MWCNT content has been produced by the combined use of carbon nanofibers (CNF) and MWCNT, so that the total nanofiller content was increased to 30 wt% in the nanocomposite with PP—15 wt% MWCNT—15 wt%CNF.

  19. Presentation and verification of a simple mathematical model foridentification of the areas behind noise barrierwith the highest performance

    Directory of Open Access Journals (Sweden)

    M. Monazzam

    2009-07-01

    Full Text Available Background and aims   Traffic noise barriers are the most important measure to control the environmental noise pollution. Diffraction from top edge of noise barriers is the most important path of indirect sound wave moves towards receiver.Therefore, most studies are focused on  improvement of this kind.   Methods   T-shape profile barriers are one of the most successful barrier among many different profiles. In this investigation the theory of destructive effect of diffracted waves from real edge of barrier and the wave diffracted from image of the barrier with phase difference of radians is used. Firstly a simple mathematical representation of the zones behind rigid and absorbent T- shape barriers with the highest insertion loss using the destructive effect of indirect path via barrier  image is introduced and then two different profile reflective and absorption barrier is used for  verification of the introduced model   Results   The results are then compared with the results of a verified two dimensional boundary element method at 1/3 octave band frequencies and in a wide field behind those barriers. Avery good agreement between the results has been achieved. In this method effective height is used for any different profile barriers.   Conclusion   The introduced model is very simple, flexible and fast and could be used for choosing the best location of profile rigid and absorptive barriers to achieve the highest  performance.  

  20. The Idea of a Highest Divine Principle — Founding Reason and Spirituality. A Necessary Concept of a Comparative Philosophy?

    Directory of Open Access Journals (Sweden)

    Claudia Bickmann

    2012-10-01

    Full Text Available By reference to the Platonic, Aristotelian, and Neo-Platonic philosophical traditions (and then to German Idealism, including Husserl and Heidegger, I will indicate the way in which the concept of reason—on the one side—depends on the horizon of spirituality (by searching for the ultimate ground within us and the striving for the highest good; and inversely—how far the idea of the divine or our spiritual self may be deepened, understood and transmitted by reference to reason and rationality. But whereas philosophical analysis aims at the universal dimensions of spirituality or the divine (as in Plato's idea of the 'highest good', the Aristotelian 'Absolute substance', the 'Oneness of the One' (Plotinus and the Neo-Platonists or the Hegelian 'Absolute spirit',—Comparative Theology may preserve the dimension of spirituality or divinity in its individuality and specifity. Comparative Theology mediates between the universality of the philosophical discourse and the uniqueness of our individual experience (symbolized by a sacred person—such as Jesus, Brahman, Buddha or Mohammed by reflecting and analyzing our religious experiences and practices. Religion may lose its specificity by comparative conceptual analysis within the field of philosophy, but Comparative Theology may enhance the vital dimensions of the very same spiritual experience by placing them in a comparative perspective.

  1. Energies; Energies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    In the framework of the National Debate on the energies in a context of a sustainable development some associations for the environment organized a debate on the nuclear interest facing the renewable energies. The first part presents the nuclear energy as a possible solution to fight against the greenhouse effect and the associated problem of the wastes management. The second part gives information on the solar energy and the possibilities of heat and electric power production. A presentation of the FEE (French wind power association) on the situation and the development of the wind power in France, is also provided. (A.L.B.)

  2. Chromium Fractions Changes Compared With Total-Cr As Determined by Neutron Activation Analysis Technique

    International Nuclear Information System (INIS)

    Abdel-Sabour, M.F.; Abdou, F.M.; Elwan, I.M.; Al-Salama, Y.J.

    2003-01-01

    Fifteen soil samples were chosen from different locations (five different locations at north greater Cairo, Egypt to represent different soils (alluvial and sandy) as well as different source of contaminated wastewater (sewage and industrial effluent). Using sequential extraction technique (extracting the soil with different solutions, which is designed to separate metal fractions), Cr was separated into six operationally defined fractions water soluble, exchangeable, carbonate bound, Fe-Mn oxides bound, organic bound and residual fractions. Result of soil total-Cr indicated the serious accumulation of Cr in soils subjected to prolonged irrigation with contaminated wastewater. As it could seen, total-Cr in the tested contaminated soils exceeds the permissible levels (75-100)ppm Cr by several order of magnitude particularly at the surface and subsurface layers. The highest accumulation of total Cr down to depth 60 cm was observed in case of soil E. Data showed that values of total Cr determined by NAA method were always higher than the relevant values determined either by AAS or those calculated after the sequential extraction method. T-test analysis showed the significant difference between NAA and either AAS or sequential extraction methods. Although T-test analysis showed that were significant differences between total content in soils as determined by destructive (AAS or SUM) and non-destructive (NAA) analytical techniques however, strong liner relation between NAA and other tested methods was obtained. Chromium distribution between different extractants shows that the greatest amounts are found in the residual and Occluded in Fe and Mn-Oxides fractions followed by carbonate or organic fractions. In most cases the proportion of all tested Cr-forms has increased in contaminated soil layers with higher enrichment in organically bound Cr, occluded in Fe and Mn oxides, carbonate exchangeable and soluble fractions. Results indicate that soil properties have a

  3. Determination of Cr(VI) in wood specimen: A XANES study at the Cr K edge

    International Nuclear Information System (INIS)

    Strub, E.; Plarre, R.; Radtke, M.; Reinholz, U.; Riesemeier, H.; Schoknecht, U.; Urban, K.; Juengel, P.

    2008-01-01

    The content of chromium in different oxidation states in chromium-treated wood was studied with XANES (X-ray absorption near-edge structure) measurements at the Cr K absorption edge. It could be shown that wood samples treated with Cr(VI) (pine and beech) did still contain a measurable content of Cr(VI) after four weeks conditioning. If such wood samples were heat exposed for 2 h with 135 deg. C prior conditioning, Cr(VI) was no longer detected by XANES, indicating a complete reduction to chromium (III)

  4. Bicarbonate catalysis of exchange synthesis of [51Cr]Cr(III)-EDTA and other chromium complexes

    International Nuclear Information System (INIS)

    Aronson, F.L.; Strashun, A.M.; Lopez, C.; Steigman, J.

    1993-01-01

    Exchange syntheses of trivalent chromium complexes often require heating, thus limiting tagging of heat-sensitive biological compounds with 51 Cr. Bicarbonate at pH 6, accelerates the formation of mM Cr-EDTA. Accordingly, room temperature catalysis with [ 51 Cr]Cr(III) at 10 -7 -10 -8 M was investigated. Complexes were successfully formed with EDTA and iminodiacetic acid (electrophoretic analysis) and acetylacetone and tropolone (analyzed by chloroform extraction). The formation of these complexes normally requires extensive heating. (author)

  5. Isotope Effects in the Bonds of beta-CrOOH and beta-CrOOD

    DEFF Research Database (Denmark)

    Nørlund Christensen, A.; Hansen, P.; Lehmann, M. S.

    1976-01-01

    Samples of orthorhombic chromium oxide hydroxide, beta -CrOOH, and the deuterated compound, beta -CrOOD, were prepared hydrothermally. The crystal structures were determined by powder profile refinement technique using neutron diffraction data. Unit cells are: beta -CrOOH: a equals 4. 862(2) A, b...... equals 4. 298(a) A, c equals 2. 995(1) A; beta -CrOOD: a equals 4. 873(5) A, b equals 4. 332(7) A, c equals 2. 963(2) A, with Z equals 2. The space group is P2//1nm or Pnnm....

  6. Influence of a niobium coating on sulfidation resistance of FeCr and FeCrY alloys

    International Nuclear Information System (INIS)

    Geribola, Gulherme Altomari

    2014-01-01

    Niobium and niobium based alloys are currently used in many industrial applications because they offer excellent resistance to degradation in various corrosive environments. These media include gaseous atmospheres at high temperatures such as those found in existing coal gasifying plants in power plants for energy generation. These atmospheres are complex gas mixtures that contain sulfur and oxygen, among other compounds. Sulphides are thermodynamically less stable, have lower melting points and often have larger deviations from stoichiometry compared to the corresponding oxides. Although there are studies regarding the use of refractory metals in high temperature sulphidizing atmospheres, the use of niobium compounds has not been adequately evaluated and there is very little studies available in the literature about its use as a protective coating. The aim of this study was to evaluate the effect of a niobium film, deposited by magnetron sputtering on the isothermal sulphidation behavior of Fe-20Cr and Fe-20Cr-1Y alloys. The sulphidation tests were carried out at 500, 600 and 700 deg C for 2h in H 2 /2% H2S atmosphere. The sulphidation resistance was determined by mass gain per unit area. The sulphidation behavior of the coated and uncoated alloys was similar at 500 deg C, and none of the alloys scaled. At 700 deg C FeCr alloy scaled in the form of a fine powder, while the reaction product formed on the alloy FeCrY scaled in the form of plates. The effect of niobium became pronounced at 700 deg C. The reaction product layer formed on the coated alloy was thinner and more plastic than that formed on the uncoated alloy. The mass gain per unit area of the coated alloys decreased significantly and they did not scaled. (author)

  7. Modacrylic anion-exchange fibers for Cr(VI) removal from chromium-plating rinse water in batch and flow-through column experiments.

    Science.gov (United States)

    Lee, Seung-Chan; Kang, Jin-Kyu; Sim, Eun-Hye; Choi, Nag-Choul; Kim, Song-Bae

    2017-11-10

    The aim of this study was to investigate Cr(VI) removal from chromium-plating rinse water using modacrylic anion-exchange fibers (KaracaronTM KC31). Batch experiments were performed with synthetic Cr(VI) solutions to characterize the KC31 fibers in Cr(VI) removal. Cr(VI) removal by the fibers was affected by solution pH; the Cr(VI) removal capacity was the highest at pH 2 and decreased gradually with a pH increase from 2 to 12. In regeneration and reuse experiments, the Cr(VI) removal capacity remained above 37.0 mg g -1 over five adsorption-desorption cycles, demonstrating that the fibers could be successfully regenerated with NaCl solution and reused. The maximum Cr(VI) removal capacity was determined to be 250.3 mg g -1 from the Langmuir model. In Fourier-transform infrared spectra, a Cr = O peak newly appeared at 897 cm -1 after Cr(VI) removal, whereas a Cr-O peak was detected at 772 cm -1 due to the association of Cr(VI) ions with ion-exchange sites. X-ray photoelectron spectroscopy analyses demonstrated that Cr(VI) was partially reduced to Cr(III) after the ion exchange on the surfaces of the fibers. Batch experiments with chromium-plating rinse water (Cr(VI) concentration = 1178.8 mg L -1 ) showed that the fibers had a Cr(VI) removal capacity of 28.1-186.4 mg g -1 under the given conditions (fiber dose = 1-10 g L -1 ). Column experiments (column length = 10 cm, inner diameter = 2.5 cm) were conducted to examine Cr(VI) removal from chromium-plating rinse water by the fibers under flow-through column conditions. The Cr(VI) removal capacities for the fibers at flow rates of 0.5 and 1.0 mL min -1 were 214.8 and 171.5 mg g -1 , respectively. This study demonstrates that KC31 fibers are effective in the removal of Cr(VI) ions from chromium-plating rinse water.

  8. A comprehensive study of piezomagnetic response in CrPS4 monolayer: mechanical, electronic properties and magnetic ordering under strains

    Science.gov (United States)

    Joe, Minwoong; Lee, Hosik; Menderes Alyörük, M.; Lee, Jinhwan; Youb Kim, Sung; Lee, Changgu; Lee, Jun Hee

    2017-10-01

    We performed first-principles calculations to investigate the magnetic, mechanical and electronic properties of the tetrachalcogenide CrPS4. Although bulk CrPS4 has been shown to exhibit a low-dimensional antiferromagnetic (AFM) ground state where ferromagnetic (FM) Cr-chains are coupled antiferromagnetically, our calculations indicated that the monolayer can be transformed to an FM material by applying a uniaxial tensile strain of  ⩾4% along the FM Cr-chain direction. The AFM-to-FM transition is explained to be driven by an increase of the exchange interaction induced by a decrease in the distance between the FM Cr-chains. A huge nonlinear piezomagnetism was predicted at the strain-induced magnetic phase boundary. Our study provides insight about rational design of single-layer magnetic materials for a wide range of spintronic devices and energy applications.

  9. Research of mercury removal from sintering flue gas of iron and steel by the open metal site of Mil-101(Cr).

    Science.gov (United States)

    Zhao, Songjian; Mei, Jian; Xu, Haomiao; Liu, Wei; Qu, Zan; Cui, Yong; Yan, Naiqiang

    2018-06-05

    Metal-organic frameworks (MOFs) adsorbent Mil-101(Cr) was introduced for the removal of elemental mercury from sintering flue gas. Physical and chemical characterization of the adsorbents showed that MIL-101(Cr) had the largest BET surface area, high thermal stability and oxidation capacity. Hg 0 removal performance analysis indicated that the Hg 0 removal efficiency of MIL-101(Cr) increased with the increasing temperature and oxygen content. Besides, MIL-101(Cr) had the highest Hg 0 removal performance compared with Cu-BTC, UiO-66 and activated carbon, which can reach about 88% at 250 °C. The XPS and Hg-TPD methods were used to analyze the Hg 0 removal mechanism; the results show that Hg 0 was first adsorbed on the surface of Mil-101(Cr), and then oxidized by the open metal site Cr 3+ . The generated Hg 2+ was then combined surface adsorbed oxygen of adsorbent to form HgO, and the open metal site Cr 2+ was oxidized to Cr 3+ by surface active oxygen again. Furthermore, MIL-101(Cr) had good chemical and thermal stability. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Searching for “LiCrIIPO4”

    International Nuclear Information System (INIS)

    Mosymow, E.; Glaum, R.; Kremer, R.K.

    2014-01-01

    The two new phosphates LiCr II 4 (PO 4 ) 3 and Li 5 Cr II 2 Cr III (PO 4 ) 4 are discovered as equilibrium phases (ϑ=800 °C) in the quarternary system Li/Cr/P/O. Their crystal structures have been determined from single-crystal X-ray diffraction data (LiCr II 4 (PO 4 ) 3 : violet-blue, Pnma (no. 62), Z=4, a=6.175(1) Å, b=14.316(3) Å, c=10.277(2) Å, 100 parameters, R 1 =0.028, wR 2 =0.08, 2060 unique reflections with F o >4σ(F o ); Li 5 Cr II 2 Cr III (PO 4 ) 4 : greyish-green, P1 ¯ (no. 2), Z=1, a=4.9379(7) Å, b=7.917(2) Å, c=8.426(2) Å, α=109.98(2)°, β=90.71(1)°, γ=104.91(1)°, 131 parameters, R 1 =0.022, wR 2 =0.067, 1594 unique reflections with F o >4σ(F o )). Li 5 Cr II 2 Cr III (PO 4 ) 4 adopts an hitherto unknown structure type. The crystal structure of LiCr II 4 (PO 4 ) 3 is isotypic to that of NaCd II 4 (PO 4 ) 3 and related to that of the mineral silicocarnotite Ca 5 (PO 4 ) 2 (SiO 4 ). Significant disorder between Li + and Cr 2+ is observed for both crystal structures. The oxidation states assigned to chromium in these two phosphates are in agreement with UV/vis/NIR absorption spectra and magnetic susceptibility data recorded for both compounds. Instead of “LiCr II PO 4 ” mixtures of LiCr II 4 (PO 4 ) 3 , Li 5 Cr II 2 Cr III (PO 4 ) 4 , Cr 2 O 3 , and CrP are observed at equilibrium. Instead of “Li 2 Cr II P 2 O 7 ” four-phase mixtures consisting of Li 9 Cr III 3 (P 2 O 7 ) 3 (PO 4 ) 2 , Li 3 Cr III 2 (PO 4 ) 3 , LiCrP 2 O 7 , and CrP were obtained. - Graphical abstract: Investigations on the equilibrium relations in the system Li/Cr/P/O revealed the two hitherto unknown phosphates Li 5 Cr II 2 Cr III (PO 4 ) 4 and LiCr II 4 (PO 4 ) 3 . They form instead of “LiCr II PO 4 ”. The crystal structures, magnetic behavior and optical spectra of these phosphates are reported. - Highlights: • The two new phosphates Li 5 Cr II 2 Cr III (PO 4 ) 4 and LiCr II 4 (PO 4 ) 3 have been characterized. • Optical spectra and paramagnetism of

  11. High Cr ODS steels R and D for high burnup fuel cladding

    International Nuclear Information System (INIS)

    Kimura, A.; Kasada, R.; Kishimoto, H.; Iwata, N.; Cho, H.-S.; Toda, N.; Yutani, K.; Ukai, S.; Fujiwara, M.

    2007-01-01

    High-performance cladding materials is essential to realize highly efficient and high-burnup operation over 150 GWd/t of so called Generation IV nuclear energy systems, such as supercritical-water-cooled reactor (SCWR) and lead-cooled fast reactor (LFR). Oxide dispersion strengthening (ODS) ferritic/ martensitic steels, which contain 9-12%Cr, show rather high resistance to neutron irradiation embrittlement and high strength at elevated temperatures. However, their corrosion resistance is not good enough in SCW and in lead at high temperatures. High-Cr ODS steels have been developed to improve corrosion resistance. An increase in Cr content an addition resulted in a drastic improvement of corrosion resistance in SCW and in lead. On the contrary, high-Cr steels often show an enhancement of aging embrittlement as well as irradiation embrittlement. Anisotropy in tensile properties is another issue. In order to overwhelm these issues, surveillance tests of the material performance have been performed for high Cr-ODS steels produced by new processing technologies. It is demonstrated that the dispersion of nono-sized oxide particles in high density is effective to attain high-performance and high-Cr ODS steels have a high potential as fuel cladding materials for SCWR and LFR with high efficiency and high burnup. (authors)

  12. Microstructure and Mechanical Properties of n-irradiated Fe-Cr Model Alloys

    International Nuclear Information System (INIS)

    Matijasevic, Milena; Al Mazouzi, Abderrahim

    2008-01-01

    High chromium ( 9-12 wt %) ferritic/martensitic steels are candidate structural materials for future fusion reactors and other advanced systems such as accelerator driven systems (ADS). Their use for these applications requires a careful assessment of their mechanical stability under high energy neutron irradiation and in aggressive environments. In particular, the Cr concentration has been shown to be a key parameter to be optimized in order to guarantee the best corrosion and swelling resistance, together with the least embrittlement. In this work, the characterization of the neutron irradiated Fe-Cr model alloys with different Cr % with respect to microstructure and mechanical tests will be presented. The behavior of Fe-Cr alloys have been studied using tensile tests at different temperature range ( from -160 deg. C to 300 deg. C). Irradiation-induced microstructure changes have been studied by TEM for two different irradiation doses at 300 deg. C. The density and the size distribution of the defects induced have been determined. The tensile test results indicate that Cr content affects the hardening behavior of Fe-Cr binary alloys. Hardening mechanisms are discussed in terms of Orowan type of approach by correlating TEM data to the measured irradiation hardening. (authors)

  13. Electrical and optical properties of ITO and ITO/Cr-doped ITO films

    International Nuclear Information System (INIS)

    Caricato, A.P.; Cesaria, M.; Luches, A.; Martino, M.; Valerini, D.; Maruccio, G.; Catalano, M.; Cola, A.; Manera, M.G.; Lomascolo, M.; Taurino, A.; Rella, R.

    2010-01-01

    In this paper we report on the effects of the insertion of Cr atoms on the electrical and optical properties of indium tin oxide (ITO) films to be used as electrodes in spin-polarized light-emitting devices. ITO films and ITO(80 nm)/Cr-doped ITO(20 nm) bilayers and Cr-doped ITO films with a thickness of 20 nm were grown by pulsed ArF excimer laser deposition. The optical, structural, morphological and electrical properties of ITO films and ITO/Cr-doped structures were characterized by UV-Visible transmission and reflection spectroscopy, transmission electron microscopy (TEM), atomic force microscopy (AFM) and Hall-effect analysis. For the different investigations, the samples were deposited on different substrates like silica and carbon coated Cu grids. ITO films with a thickness of 100 nm, a resistivity as low as ∝4 x 10 -4 Ω cm, an energy gap of ∝4.3 eV and an atomic scale roughness were deposited at room temperature without any post-deposition process. The insertion of Cr into the ITO matrix in the upper 20 nm of the ITO matrix induced variations in the physical properties of the structure like an increase of average roughness (∝0.4-0.5 nm) and resistivity (up to ∝8 x 10 -4 Ω cm). These variations were correlated to the microstructure of the Cr-doped ITO films with particular attention to the upper 20 nm. (orig.)

  14. Electrical and optical properties of ITO and ITO/Cr-doped ITO films

    Science.gov (United States)

    Caricato, A. P.; Cesaria, M.; Luches, A.; Martino, M.; Maruccio, G.; Valerini, D.; Catalano, M.; Cola, A.; Manera, M. G.; Lomascolo, M.; Taurino, A.; Rella, R.

    2010-12-01

    In this paper we report on the effects of the insertion of Cr atoms on the electrical and optical properties of indium tin oxide (ITO) films to be used as electrodes in spin-polarized light-emitting devices. ITO films and ITO(80 nm)/Cr-doped ITO(20 nm) bilayers and Cr-doped ITO films with a thickness of 20 nm were grown by pulsed ArF excimer laser deposition. The optical, structural, morphological and electrical properties of ITO films and ITO/Cr-doped structures were characterized by UV-Visible transmission and reflection spectroscopy, transmission electron microscopy (TEM), atomic force microscopy (AFM) and Hall-effect analysis. For the different investigations, the samples were deposited on different substrates like silica and carbon coated Cu grids. ITO films with a thickness of 100 nm, a resistivity as low as ˜4×10-4 Ω cm, an energy gap of ˜4.3 eV and an atomic scale roughness were deposited at room temperature without any post-deposition process. The insertion of Cr into the ITO matrix in the upper 20 nm of the ITO matrix induced variations in the physical properties of the structure like an increase of average roughness (˜0.4-0.5 nm) and resistivity (up to ˜8×10-4 Ω cm). These variations were correlated to the microstructure of the Cr-doped ITO films with particular attention to the upper 20 nm.

  15. Strong magnetization and Chern insulators in compressed graphene/CrI 3 van der Waals heterostructures

    Science.gov (United States)

    Zhang, Jiayong; Zhao, Bao; Zhou, Tong; Xue, Yang; Ma, Chunlan; Yang, Zhongqin

    2018-02-01

    Graphene-based heterostructures are a promising material system for designing the topologically nontrivial Chern insulating devices. Recently, a two-dimensional monolayer ferromagnetic insulator CrI3 was successfully synthesized in experiments [B. Huang et al., Nature (London) 546, 270 (2017), 10.1038/nature22391]. Here, these two interesting materials are proposed to build a heterostructure (Gr /CrI3). Our first-principles calculations show that the system forms a van der Waals (vdW) heterostructure, which is relatively facilely fabricated in experiments. A Chern insulating state is acquired in the Gr /CrI3 heterostructure if the vdW gap is compressed to a distance between about 3.3 and 2.4 Å, corresponding to a required external pressure between about 1.4 and 18.3 GPa. Amazingly, very strong magnetization (about 150 meV) is found in graphene, induced by the substrate CrI3, despite the vdW interactions between them. A low-energy effective model is employed to understand the mechanism. The work functions, contact types, and band alignments of the Gr /CrI3 heterostructure system are also studied. Our work demonstrates that the Gr /CrI3 heterostructure is a promising system to observe the quantum anomalous Hall effect at high temperatures (up to 45 K) in experiments.

  16. Theoretical investigation of spin-filtering in CrAs/GaAs heterostructures

    International Nuclear Information System (INIS)

    Stickler, B. A.; Ertler, C.; Pötz, W.; Chioncel, L.

    2013-01-01

    The electronic structure of bulk zinc-blende GaAs, zinc-blende and tetragonal CrAs, and CrAs/GaAs supercells, computed within linear muffin-tin orbital (LMTO) local spin-density functional theory, is used to extract the band alignment for the [1,0,0] GaAs/CrAs interface in dependence of the spin orientation. With the lateral lattice constant fixed to the experimental bulk GaAs value, a local energy minimum is found for a tetragonal CrAs unit cell with a longitudinal ([1,0,0]) lattice constant reduced by ≈2%. Due to the identified spin-dependent band alignment, half-metallicity of CrAs no longer is a key requirement for spin-filtering. Based on these findings, we study the spin-dependent tunneling current in [1,0,0] GaAs/CrAs/GaAs heterostructures within the non-equilibrium Green's function approach for an effective tight-binding Hamiltonian derived from the LMTO electronic structure. Results indicate that these heterostructures are promising candidates for efficient room-temperature all-semiconductor spin-filtering devices

  17. Influence of Al2O3 reinforcement on precipitation kinetic of Cu–Cr nanocomposite

    International Nuclear Information System (INIS)

    Sheibani, S.; Ataie, A.; Heshmati-Manesh, S.; Caballero, A.; Criado, J.M.

    2011-01-01

    Highlights: ► Cr precipitation in Cu-1 wt.% Cr solid solution is based on nucleation and growth models. ► The overall ageing process is accelerated by the presence of Al 2 O 3 reinforcement. ► Al 2 O 3 –Cu interfaces act as primary nucleation sites. ► Structural defects act as secondary nucleation sites. - Abstract: In this paper, the kinetic of precipitation process in mechanically alloyed Cu-1 wt.% Cr and Cu-1 wt.% Cr/3 wt.% Al 2 O 3 solid solution was compared using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The ageing kinetics in Cu–Cr and Cu–Cr/Al 2 O 3 can be described using Johnson–Mehl–Avrami (JMA) and Sestak–Berggren (SB) models, respectively. These different behaviors have been discussed in details. It was found that in presence of Al 2 O 3 reinforcement, the ageing activation energy is decreased and the overall ageing process is accelerated. This behavior is probably due to higher dislocation density previously obtained during ball milling and Al 2 O 3 –Cu interface. TEM observations confirm that Al 2 O 3 –Cu interface and structural defects act as a primary and secondary nucleation sites, respectively.

  18. Who jumps the highest? Anthropometric and physiological correlations of vertical jump in youth elite female volleyball players.

    Science.gov (United States)

    Nikolaidis, Pantelis T; Gkoudas, Konstantinos; Afonso, José; Clemente-Suarez, Vicente J; Knechtle, Beat; Kasabalis, Stavros; Kasabalis, Athanasios; Douda, Helen; Tokmakidis, Savvas; Torres-Luque, Gema

    2017-06-01

    The aim of the present study was to examine the relationship of vertical jump (Abalakov jump [AJ]) with anthropometric and physiological parameters in youth elite female volleyball players. Seventy-two selected volleyball players from the region of Athens (age 13.3±0.7 years, body mass 62.0±7.2 kg, height 171.5±5.7 cm, body fat 21.2±4.5%), classified into quartiles according to AJ performance (group A, 21.4-26.5 cm; group B, 26.8-29.9 cm; group C, 30.5-33.7 cm; group D, 33.8-45.9 cm), performed a series of physical fitness tests. AJ was correlated with anthropometric (age at peak height velocity [APHV]: r=0.38, Pvolleyball players that jumped the highest were those who matured later than others.

  19. Repeated Radionuclide therapy in metastatic paraganglioma leading to the highest reported cumulative activity of 131I-MIBG

    International Nuclear Information System (INIS)

    Ezziddin, Samer; Sabet, Amir; Ko, Yon-Dschun; Xun, Sunny; Matthies, Alexander; Biersack, Hans-Jürgen

    2012-01-01

    131 I-MIBG therapy for neuroendocrine tumours may be dose limited. The common range of applied cumulative activities is 10-40 GBq. We report the uneventful cumulative administration of 111 GBq (= 3 Ci) 131 I-MIBG in a patient with metastatic paraganglioma. Ten courses of 131 I-MIBG therapy were given within six years, accomplishing symptomatic, hormonal and tumour responses with no serious adverse effects. Chemotherapy with cisplatin/vinblastine/dacarbazine was the final treatment modality with temporary control of disease, but eventually the patient died of progression. The observed cumulative activity of 131 I-MIBG represents the highest value reported to our knowledge, and even though 12.6 GBq of 90 Y-DOTATOC were added intermediately, no associated relevant bone marrow, hepatic or other toxicity were observed. In an individual attempt to palliate metastatic disease high cumulative activity alone should not preclude the patient from repeat treatment

  20. Impact of thermal frequency drift on highest precision force microscopy using quartz-based force sensors at low temperatures

    Directory of Open Access Journals (Sweden)

    Florian Pielmeier

    2014-04-01

    Full Text Available In frequency modulation atomic force microscopy (FM-AFM the stability of the eigenfrequency of the force sensor is of key importance for highest precision force measurements. Here, we study the influence of temperature changes on the resonance frequency of force sensors made of quartz, in a temperature range from 4.8–48 K. The sensors are based on the qPlus and length extensional principle. The frequency variation with temperature T for all sensors is negative up to 30 K and on the order of 1 ppm/K, up to 13 K, where a distinct kink appears, it is linear. Furthermore, we characterize a new type of miniaturized qPlus sensor and confirm the theoretically predicted reduction in detector noise.

  1. A common founder mutation in FANCA underlies the world's highest prevalence of Fanconi anemia in Gypsy families from Spain.

    Science.gov (United States)

    Callén, Elsa; Casado, José A; Tischkowitz, Marc D; Bueren, Juan A; Creus, Amadeu; Marcos, Ricard; Dasí, Angeles; Estella, Jesús M; Muñoz, Arturo; Ortega, Juan J; de Winter, Johan; Joenje, Hans; Schindler, Detlev; Hanenberg, Helmut; Hodgson, Shirley V; Mathew, Christopher G; Surrallés, Jordi

    2005-03-01

    Fanconi anemia (FA) is a genetic disease characterized by bone marrow failure and cancer predisposition. Here we have identified Spanish Gypsies as the ethnic group with the world's highest prevalence of FA (carrier frequency of 1/64-1/70). DNA sequencing of the FANCA gene in 8 unrelated Spanish Gypsy FA families after retroviral subtyping revealed a homozygous FANCA mutation (295C>T) leading to FANCA truncation and FA pathway disruption. This mutation appeared specific for Spanish Gypsies as it is not found in other Gypsy patients with FA from Hungary, Germany, Slovakia, and Ireland. Haplotype analysis showed that Spanish Gypsy patients all share the same haplotype. Our data thus suggest that the high incidence of FA among Spanish Gypsies is due to an ancestral founder mutation in FANCA that originated in Spain less than 600 years ago. The high carrier frequency makes the Spanish Gypsies a population model to study FA heterozygote mutations in cancer.

  2. The Mass Elevation Effect of the Central Andes and Its Implications for the Southern Hemisphere's Highest Treeline

    Directory of Open Access Journals (Sweden)

    Wenhui He

    2016-05-01

    Full Text Available One of the highest treelines in the world is at 4810 m above sea level on the Sajama Volcano in the central Andes. The climatological cause of that exceptionally high treeline position is still unclear. Although it has been suggested that the mass elevation effect (MEE explains the upward shift of treelines in the Altiplano region, the magnitude of MEE has not yet been quantified for that region. This paper defines MEE as the air temperature difference in summer at the same elevation between the inner mountains/plateaus (Altiplano and the free atmosphere above the adjacent lowlands of the Andean Cordillera. The Altiplano air temperature was obtained from the Global Historical Climatology Network-Monthly temperature database, and the air temperature above the adjacent lowlands was interpolated based on the National Center for Environmental Prediction/National Center for Atmospheric Research Reanalysis 1 data set. We analyzed the mean air temperature differences for January, July, and the warm months from October to April. The air temperature was mostly higher on the Altiplano than over the neighboring lowlands at the same altitude. The air temperature difference increased from the outer Andean east-facing slope to the interior of the Altiplano in summer, and it increased from high latitudes to low latitudes in winter. The mean air temperature in the Altiplano in summer is approximately 5 K higher than it is above the adjacent lowlands at the same mean elevation, averaging about 3700 m above sea level. This upward shift of isotherms in the inner part of the Cordillera enables the treeline to climb to 4810 m, with shrub-size trees reaching even higher. Therefore, the MEE explains the occurrence of one of the world’s highest treelines in the central Andes.

  3. Contact with HIV prevention services highest in gay and bisexual men at greatest risk: cross-sectional survey in Scotland

    Directory of Open Access Journals (Sweden)

    Hart Graham J

    2010-12-01

    Full Text Available Abstract Background Men who have sex with men (MSM remain the group most at risk of acquiring HIV in the UK and new HIV prevention strategies are needed. In this paper, we examine what contact MSM currently have with HIV prevention activities and assess the extent to which these could be utilised further. Methods Anonymous, self-complete questionnaires and Orasure™ oral fluid collection kits were distributed to men visiting the commercial gay scenes in Glasgow and Edinburgh in April/May 2008. 1508 men completed questionnaires (70.5% response rate and 1277 provided oral fluid samples (59.7% response rate; 1318 men were eligible for inclusion in the analyses. Results 82.5% reported some contact with HIV prevention activities in the past 12 months, 73.1% obtained free condoms from a gay venue or the Internet, 51.1% reported accessing sexual health information (from either leaflets in gay venues or via the Internet, 13.5% reported talking to an outreach worker and 8.0% reported participating in counselling on sexual health or HIV prevention. Contact with HIV prevention activities was associated with frequency of gay scene use and either HIV or other STI testing in the past 12 months, but not with sexual risk behaviours. Utilising counselling was also more likely among men who reported having had an STI in the past 12 months and HIV-positive men. Conclusions Men at highest risk, and those likely to be in contact with sexual health services, are those who report most contact with a range of current HIV prevention activities. Offering combination prevention, including outreach by peer health workers, increased uptake of sexual health services delivering behavioural and biomedical interventions, and supported by social marketing to ensure continued community engagement and support, could be the way forward. Focused investment in the needs of those at highest risk, including those diagnosed HIV-positive, may generate a prevention dividend in the long

  4. Energy efficiency in future wireless networks: cognitive radio standardization requirements

    CSIR Research Space (South Africa)

    Masonta, M

    2012-09-01

    Full Text Available Energy consumption of mobile and wireless networks and devices is significant, indirectly increasing greenhouse gas emissions and energy costs for operators. Cognitive radio (CR) solutions can save energy for such networks and devices; moreover...

  5. Dielectric response and room temperature ferromagnetism in Cr doped anatase TiO2 nanoparticles

    Science.gov (United States)

    Naseem, Swaleha; Khan, Wasi; Khan, Shakeel; Husain, Shahid; Ahmad, Abid

    2018-02-01

    In the present work, nanocrystalline samples of Ti1-xCrxO2 (x = 0, 0.02, 0.04, 0.06 and 0.08) were synthesized in anatase phase through simple and cost effective acid modified sol gel method. The influence of Cr doping on thermal, microstructural, electrical and magnetic properties was investigated in TiO2 host matrix. The surface morphology has revealed less agglomeration a