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Sample records for bsub hffrfe studied

  1. Study of the weak annihilation contributions in charmless B{sub s} → VV decays

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    Chang, Qin [Henan Normal University, Institute of Particle and Nuclear Physics, Henan (China); Central China Normal University, Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOE), Wuhan, Hubei (China); Li, Xiaonan; Sun, Junfeng [Henan Normal University, Institute of Particle and Nuclear Physics, Henan (China); Li, Xin-Qiang [Central China Normal University, Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOE), Wuhan, Hubei (China)

    2017-06-15

    In this paper, in order to probe the spectator-scattering and weak annihilation contributions in charmless B{sub s} → VV (where V stands for a light vector meson) decays, we perform the χ{sup 2}-analyses for the endpoint parameters within the QCD factorization framework, under the constraints from the measured anti B{sub s} → ρ{sup 0}φ, φK{sup *0}, φφ and K{sup *0} anti K{sup *0} decays. The fitted results indicate that the endpoint parameters in the factorizable and nonfactorizable annihilation topologies are non-universal, which is also favored by the charmless B → PP and PV (where P stands for a light pseudo-scalar meson) decays observed in previous work. Moreover, the abnormal polarization fractions f{sub L,} {sub perpendicular} {sub to} (anti B{sub s} → K{sup *0} anti K{sup *0}) = (20.1±7.0)%, (58.4±8.5)% measured by the LHCb collaboration can be reconciled through the weak annihilation corrections. However, the branching ratio of anti B{sub s} → φK{sup *0} decay exhibits a tension between the data and theoretical result, which dominates the contributions to χ{sub min}{sup 2} in the fits. Using the fitted endpoint parameters, we update the theoretical results for the charmless B{sub s} → VV decays, which will be further tested by the LHCb and Belle-II experiments in the near future. (orig.)

  2. Fluorescence enhancement of the aflatoxin B{sub 1} by forming inclusion complexes with some cyclodextrins and molecular modeling study

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    Aghamohammadi, Mohammad [Department of Chemistry, Faculty of Science, Tarbiat Modarres University, P.O. Box 14115-111, Tehran (Iran, Islamic Republic of); Alizadeh, Naader [Department of Chemistry, Faculty of Science, Tarbiat Modarres University, P.O. Box 14115-111, Tehran (Iran, Islamic Republic of)], E-mail: alizaden@modares.ac.ir

    2007-12-15

    The interaction between the aflatoxin B{sub 1} (AFB{sub 1}) and three cyclodextrins, {alpha}-cyclodextrin ({alpha}-CD), {beta}-cyclodextrin ({beta}-CD) and heptakis-2,6-dimethyl-o-{beta}-cyclodextrin (ome-CD), was studied by spectrofluorescence technique. It was found that the inclusion association behavior occurs for the complexes of cyclodextrins with AFB{sub 1}. The fluorescence of AFB{sub 1} is generally enhanced in the complexes with cyclodextrins in aqueous solutions. The inclusion complex constants of the three types of cyclodextrins at different temperatures were evaluated from Benesi-Hildebrand plot and also by non-linear regression analysis. These cyclodextrins can only form the 1:1 (host:guest) inclusion complex in the studied temperature range of 20-50 deg. C. The enthalpy ({delta}H{sup o}) and entropy ({delta}S{sup o}) changes of complexation were extracted from the temperature dependency of complex formation constants (K). Temperature-dependent measurements showed that the association step is controlled by enthalpy-entropy compensation effect. The use of ome-CD generally resulted in the greatest fluorescence intensity. On the other hand, the discrepancy between the exhibited enhanced fluorescence and thermodynamic parameters ({delta}G{sup o}) is proposed to be different only by the orientation of the AFB{sub 1} within the cyclodextrin cavity. To find the most favorable structure, the geometry of complex was investigated by molecular modeling approach employing the semiemperical HF-SCF calculations.

  3. Optical and XPS studies of BCN thin films by co-sputtering of B{sub 4}C and BN targets

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    Prakash, Adithya, E-mail: adithya@knights.ucf.edu; Sundaram, Kalpathy B.

    2017-02-28

    Highlights: • Wide range of optical band gaps (Eg) are achieved for dual target sputtered BCN films in the range of 1.9 eV−3.7 eV. • Optical band gap (Eg) studies are performed as a function of target powers, gas ratios and deposition temperatures. • Eg is found to increase with N{sub 2}/Ar flow ratios and deposition temperatures. • XPS studies are conducted to ascertain the chemical and bonding characteristics. • XPS showed higher h-BN and B{sub 4}C property at higher N{sub 2}/Ar gas ratios for films deposited at 20 W and 40 W B{sub 4}C power respectively. - Abstract: Boron carbon nitride (BCN) thin films are investigated for their optical properties. BCN, is the unanimous choice for inter-dielectric layer (IDL) in very large scale integration (VLSI) because of its low-k dielectric constant. Optical properties can be tailored as a function of elemental composition, which makes BCN a prospective material in UV-filters and mirrors. Films are deposited by reactive co-sputtering of boroncarbide (B{sub 4}C) and boronnitride (BN) with varying N{sub 2}/Ar gas flow ratio by DC and RF sputtering respectively. XPS studies are performed to deduce the bonding and chemical properties of the BCN thinfilms. Optical band gap (Eg) studies are performed as a result of varying target powers, gas ratios and deposition temperatures. Eg is found to increase with N{sub 2}/Ar flow ratios and deposition temperatures. BCN deposited at 20 W DC exhibited higher band gap range and the highest achieved is 3.7 eV at N{sub 2}/Ar = 0.75. Lowest value achieved is 1.9 eV at N{sub 2}/Ar = 0.25 for as-deposited films.

  4. A study of the reaction {pi}{sup -} p {yields} {omega}{pi}{sup -} p at 18 GeV/c: The D and S decay amplitudes for b{sub 1}(1235) {yields} {omega}{pi}

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    Mina Nozar; Gary Adams; T. Adams; Z. Bar-Yam; J.M. Bishop; V.A. Bodyagin; D.S. Brown; N.M. Cason; S.U. Chung; John Cummings; K. Danyo; A.I. Demianov; S.P. Denisov; V. Dorofeev; J.P. Dowd; Paul Eugenio; X.L. Fan; A.M. Gribushin; R.W. Hackenburg; M. Hayek; J. Hu; E.I. Ivanov; David Joffe; I. Kachaev; W. Kern; E. King; O.L. Kodolova; V.L. Korotkikh; M.A. Kostin; Joachim Kuhn; V.V. Lipaev; John Losecco; M. Lu; Joseph Manak; James Napolitano; C. Olchanski; Alexander Ostrovidov; T.K. Pedlar; A.V. Popov; D.I. Ryabchikov; L.I. Sarycheva; K.K. Seth; N. Shenhav; Xiaoyan Shen; W.D. Shephard; N.B. Sinev; D.L. Stienike; J.S. Suh; S.A. Taegar; A. Tomaradze; I.N. Vardanyan; Dennis Weygand; D.B. White; H.J. Willutzki; M. Witkowski; A.A. Yershov

    2002-08-08

    The reaction {pi}{sup -} p {yields} {omega}{pi}{sup -} p, {omega} {yields} {pi}{sup +} {pi}{sup -} {pi}{sup 0} has been studied at 18 GeV/c. The {omega}{pi}{sup -} mass spectrum is found to be dominated by the b{sub 1}(1235). Partial Wave Analysis shows that b{sub 1} production is dominated by natural parity exchange. The S-wave and D-wave amplitudes for b{sub 1}(1235) {yields} {omega}{pi} have been determined, and it is found that the amplitude ratio, |D/S| = 0.269 {+-} (0.009){sub stat} {+-} (0.01){sub sys} and the phase difference, {phi}(D-S) = 10.54{sup o} {+-} (2.4{sup o}){sub stat} {+-} (3.9){sub sys}.

  5. The B{sub s}{sup 0}: measurement of the life time and study of the oscillations with the ALEPH experiment; Le B{sub s}{sup 0}: mesure de la duree de vie et etude des oscillations dans l'experience ALEPH

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    Schune, M.H. [Paris-11 Univ., 91 - Orsay (France). Lab. de l' Accelerateur Lineaire]|[Universite de Paris Sud, 91 - Orsay (France)

    1997-05-22

    his work describes first the theoretical motivations for the study of the life time and the oscillation frequency of the B{sub s}{sup 0} meson. After a brief presentation of the Cabbibo-Kobayashi-Maskawa matrix, the oscillation formalism is presented and the importance of the {delta}m{sub d} and {delta}m{sub s} pointed out in the frame of the Standard Model. The author explains the importance of measuring the B{sub s}{sup 0} life time and the {delta}{gamma}{sub s}, the width difference between the two states of B{sub s}{sup 0}. The second chapter is devoted to the selection of events and the measurement of the proper time, taking the time resolution into account. The third chapter deals with the measurement of the life time and the analytical convolution used for this measurement and for the study of the oscillations. This chapter gives also the experimental result obtained for the measurement of {delta}{gamma}{sub s}. The fourth chapter states the tagging method, the variables used for it and the systematic checking. Rapid simulations are presented in the fifth chapter as well as the procedure used to give a lower limit for {delta}m{sub s}. Finally, the last chapter shows the analysis of the B{sub s}{sup 0} oscillation frequency, states the obtained limit in comparison to other results. The influence of this limit and a limit obtained by combining the results of the ALEPH and DELPHI collaborations are discussed with respect to the determination of the Standard Model parameters. (N.T.)

  6. Possible magnetism in vortex cores of superconducting TmNi{sub 2}B{sub 2}C studied by small angle neutron scattering

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    Abrahamsen, Asger Bech

    2003-11-01

    The compound TmNi{sub 2}B{sub 2}C has previously been studied by Small Angle Neutron Scattering(SANS) with the applied field along the crystalline c-axis and a very rich phase diagram in terms of flux line lattices(FLL) with different symmetries have been observed. One of the FLL transitions is coincident with a magnetic phase transition between two spin density waves. In this thesis additional SANS studies of the FLL phases in TmNi{sub 2}B{sub 2}C are reported and an interpretation of the phase diagram in the paramagnetic region is presented. It is suggested that the square FLL observed is stable in between two transition lines determined by two different length scales. The lower transition field is reached when the distance between the flux lines becomes comparable to the non-locality radius resulting from non-local electrodynamics, whereas the upper transition field is determined from the crossover from intermediate to high flux line density where the vortex cores start to overlap and the superconducting order parameter is suppressed in between the flux lines. A detailed examination of the intensity of the neutron diffraction spots caused by scattering on the flux line lattice in TmNi{sub 2}B{sub 2}C is presented and analyzed on the basis of the form factor of an isolated flux line. This analysis can not provide a good explanation for the observed scattering and it is suggested that the scattering from the Tm ions must be considered. One can argue that the moments of the Tm ions are modulated by the flux line lattice, because the Ruderman-Kittel- Kasuya-Yosida(RKKY) interaction between the Tm ions might be different inside the vortex cores than outside in the superconducting phase. A calculation of the neutron scattering cross section of such a magnetic flux line lattice has been performed and compared to the SANS data. This offers a qualitative explanation of some of the observations, but future work is needed to perform a more quantitative comparison. (au)

  7. Structural and photoluminescence study of Er-Yb codoped nanocrystalline ZrO{sub 2}-B{sub 2}O{sub 3} solid solution

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    Salas, P. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro 76000 (Mexico); Borja-Urby, R. [Grupo de Espectroscopia de Materiales Avanzados y nanoestructurados (EMANA), Centro de Investigaciones en Optica, A. C., Loma del Bosque 115, Col. Lomas del Campestre, C.P. 37150 Leon, Gto. (Mexico); Diaz-Torres, L.A., E-mail: ditlacio@cio.mx [Grupo de Espectroscopia de Materiales Avanzados y nanoestructurados (EMANA), Centro de Investigaciones en Optica, A. C., Loma del Bosque 115, Col. Lomas del Campestre, C.P. 37150 Leon, Gto. (Mexico); Rodriguez, G. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro 76000 (Mexico); Vega, M. [Centro de Geociencias, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro 76000 (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Eje Central Lazaro Cardenas 152, A.P. 14-805, 07730 Mexico, DF (Mexico)

    2012-09-20

    Codoped Er{sup 3+} and Yb{sup 3+} nanocrystalline ZrO{sub 2}-B{sub 2}O{sub 3} phosphor obtained by a modified sol-gel method is demonstrated. The addition of up to 2.5 mol% B{sub 2}O{sub 3} to nanocrystalline ZrO{sub 2}:Yb(2%), Er(1%) keep the tetragonal rare-earth stabilized ZrO{sub 2} phase; whereas higher B{sub 2}O{sub 3} content destabilize the tetragonal phase, leading to the tetragonal to monoclinic transition with no tetragonal ZrO{sub 2} phase segregation. Visible upconversion of the luminescent active ions, Er{sup 3+} and Yb{sup 3+}, depend strongly on B{sub 2}O{sub 3} content. The PL intensity is strongly quenched for high B{sub 2}O{sub 3} content due to increasing multiphonon relaxation processes related to B-O and B-O-B vibronic modes.

  8. Study of domain structure and magnetization reversal after thermal treatments in Fe{sub 40}Co{sub 38}Mo{sub 4}B{sub 18} microwires

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    Klein, P. [Institute of Physics, Faculty of Science, UPJS, Park Angelinum 9, 041 54 Kosice (Slovakia); Varga, R., E-mail: rvarga@upjs.sk [Institute of Physics, Faculty of Science, UPJS, Park Angelinum 9, 041 54 Kosice (Slovakia); Badini-Confalonieri, G.A.; Vazquez, M. [Instituto de Ciencia de Materiales de Madrid, CSIC, Sor Juana Ines de la Cruz 3, 28049 Cantoblanco, Madrid (Spain)

    2011-12-15

    We have studied the effect of thermal treatment on the magnetic domain structure and magnetic reversal process of amorphous and nanocrystalline Fe{sub 40}Co{sub 38}Mo{sub 4}B{sub 18} microwires. The domain structure and the magnetization reversal of amorphous FeCoMoB microwires reflect the complex stress distribution introduced by the glass coating. Hence, the thickness of radial domain structure decreases with temperature and the temperature dependence of the switching field presents a discontinuous behavior. After nanocrystallization, the domain structure of FeCoMoB microwire is almost constant within the temperature range 10-400 K and the switching field decreases almost linearly with temperature mostly because of the decrease of saturation magnetization. - Highlights: > Nanocrystalline FeCoMoB microwires are characterized by the high Curie temperature. > Nanocrystalline FeCoMoB microwires remains bistable even in nanocrystalline state. > Nanocrystalline FeCoMoB microwires are characterized by high magnetic stability in a wide temperature range.

  9. Thermal treatment of the Fe{sub 78}Si{sub 9}B{sub 13} alloy in it amorphous phase studied by means of Moessbauer spectroscopy; Tratamiento termico de la aleacion Fe{sub 78}Si{sub 9}B{sub 13} en su fase amorfa estudiado por medio de la espectroscopia Moessbauer

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    Cabral P, A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Lopez, A.; Garcia S, F. [Facultad de Ciencias, UAEM, 50000 Toluca, Estado de Mexico (Mexico)

    2003-07-01

    The magnetic and microhardness changes, dependents of the temperature that occur in the Fe{sub 78}Si{sub 9}B{sub 13} alloy in it amorphous state were studied by means of the Moessbauer spectroscopy and Vickers microhardness. According to the Moessbauer parameters and in particular that of the hyperfine magnetic field, this it changes according to the changes of the microhardness; i.e. if the microhardness increases, the hyperfine magnetic field increases. The registered increment of hardness in the amorphous state of this alloy should be considered as anomalous, according to the prediction of the Hall-Petch equation, the one that relates negative slopes with grain sizes every time but small. (Author)

  10. Influence of B{sub 1}-inhomogeneity on pharmacokinetic modeling of dynamic contrast-enhanced MRI: A simulation study

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    Park, Bun Woo [Dept. of Radiology, Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Choi, Byung Se [Dept. of Radiology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); and others

    2017-08-01

    To simulate the B1-inhomogeneity-induced variation of pharmacokinetic parameters on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). B1-inhomogeneity-induced flip angle (FA) variation was estimated in a phantom study. Monte Carlo simulation was performed to assess the FA-deviation-induced measurement error of the pre-contrast R1, contrast-enhancement ratio, Gd-concentration, and two-compartment pharmacokinetic parameters (Ktrans, ve, and vp). B1-inhomogeneity resulted in −23–5% fluctuations (95% confidence interval [CI] of % error) of FA. The 95% CIs of FA-dependent % errors in the gray matter and blood were as follows: −16.7–61.8% and −16.7–61.8% for the pre-contrast R1, −1.0–0.3% and −5.2–1.3% for the contrast-enhancement ratio, and −14.2–58.1% and −14.1–57.8% for the Gd-concentration, respectively. These resulted in −43.1–48.4% error for Ktrans, −32.3–48.6% error for the ve, and −43.2–48.6% error for vp. The pre-contrast R1 was more vulnerable to FA error than the contrast-enhancement ratio, and was therefore a significant cause of the Gd-concentration error. For example, a −10% FA error led to a 23.6% deviation in the pre-contrast R1, −0.4% in the contrast-enhancement ratio, and 23.6% in the Gd-concentration. In a simulated condition with a 3% FA error in a target lesion and a −10% FA error in a feeding vessel, the % errors of the pharmacokinetic parameters were −23.7% for Ktrans, −23.7% for ve, and −23.7% for vp. Even a small degree of B1-inhomogeneity can cause a significant error in the measurement of pharmacokinetic parameters on DCE-MRI, while the vulnerability of the pre-contrast R1 calculations to FA deviations is a significant cause of the miscalculation.

  11. Low-temperature sequential pulsed chemical vapor deposition of ternary B{sub x}Ga{sub 1-x}N and B{sub x}In{sub 1-x}N thin film alloys

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    Haider, Ali, E-mail: ali.haider@bilkent.edu.tr, E-mail: biyikli@unam.bilkent.edu.tr; Kizir, Seda; Ozgit-Akgun, Cagla; Biyikli, Necmi, E-mail: ali.haider@bilkent.edu.tr, E-mail: biyikli@unam.bilkent.edu.tr [National Nanotechnology Research Center (UNAM), Bilkent University, Bilkent, Ankara 06800, Turkey and Institute of Materials Science and Nanotechnology, Bilkent University, Bilkent, Ankara 06800 (Turkey); Okyay, Ali Kemal [National Nanotechnology Research Center (UNAM), Bilkent University, Bilkent, Ankara 06800 (Turkey); Institute of Materials Science and Nanotechnology, Bilkent University, Bilkent, Ankara 06800 (Turkey); Department of Electrical and Electronics Engineering, Bilkent University, Bilkent, Ankara 06800 Turkey (Turkey)

    2016-01-15

    In this work, the authors have performed sequential pulsed chemical vapor deposition of ternary B{sub x}Ga{sub 1-x}N and B{sub x}In{sub 1-x}N alloys at a growth temperature of 450 °C. Triethylboron, triethylgallium, trimethylindium, and N{sub 2} or N{sub 2}/H{sub 2} plasma have been utilized as boron, gallium, indium, and nitrogen precursors, respectively. The authors have studied the compositional dependence of structural, optical, and morphological properties of B{sub x}Ga{sub 1-x}N and B{sub x}In{sub 1-x}N ternary thin film alloys. Grazing incidence X-ray diffraction measurements showed that boron incorporation in wurtzite lattice of GaN and InN diminishes the crystallinity of B{sub x}Ga{sub 1-x}N and B{sub x}In{sub 1-x}N sample. Refractive index decreased from 2.24 to 1.65 as the B concentration of B{sub x}Ga{sub 1-x}N increased from 35% to 88%. Similarly, refractive index of B{sub x}In{sub 1-x}N changed from 1.98 to 1.74 for increase in B concentration value from 32% to 87%, respectively. Optical transmission band edge values of the B{sub x}Ga{sub 1-x}N and B{sub x}In{sub 1-x}N films shifted to lower wavelengths with increasing boron content, indicating the tunability of energy band gap with alloy composition. Atomic force microscopy measurements revealed an increase in surface roughness with boron concentration of B{sub x}Ga{sub 1-x}N, while an opposite trend was observed for B{sub x}In{sub 1-x}N thin films.

  12. Gastric emptying in patients with vitamin B{sub 12} deficiency

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    Yagci, Muenci; Yamac, Kadri; Acar, Kadir; Haznedar, Rauf [Department of Hematology, Gazi Medical School (Turkey); Cingi, Elif; Kitapci, Mehmet [Department of Nuclear Medicine, Gazi Medical School (Turkey)

    2002-09-01

    The clinical presentation of patients with vitamin B{sub 12} deficiency varies in a spectrum ranging from haematological disorders to neuropsychiatric diseases. In rare cases, orthostatic hypotension, impotence, constipation and urinary retention have been attributed to autonomic nervous system dysfunction due to vitamin B{sub 12} deficiency. The aim of this study was to evaluate the effect of vitamin B{sub 12} deficiency on autonomic nervous system function by studying gastric emptying times (T{sub 1/2}). Twenty patients with newly diagnosed vitamin B{sub 12} deficiency and 12 control patients with gastritis and normal vitamin B{sub 12} levels were enrolled in this study. Gastroduodenoscopy, endoscopic biopsy, histopathological evaluation of the biopsy specimens and radionuclide gastric emptying studies were performed. After vitamin B{sub 12} replacement therapy for 3 months, radionuclide gastric emptying studies were repeated. Mean gastric emptying T{sub 1/2} in patients before and after treatment and in controls were 103.83{+-}48.80 min, 90.00{+-}17.29 min and 74.55{+-}8.52 min, respectively. The difference in mean gastric emptying T{sub 1/2} between patients before treatment and controls was statistically significant (P<0.01). The statistically significant difference persisted after vitamin B{sub 12} treatment (P<0.05), though mean gastric emptying T{sub 1/2} was somewhat shorter. There were no positive or negative correlations between gastric emptying T{sub 1/2} and the following parameters: haemoglobin, vitamin B{sub 12} level and Helicobacter pylori positivity. In conclusion, gastric emptying T{sub 1/2} was prolonged in patients with vitamin B{sub 12} deficiency and this prolongation was not corrected after vitamin B{sub 12} replacement therapy. Although autonomic nervous system dysfunction due to vitamin B{sub 12} deficiency rarely gives rise to clinical manifestations, latent dysfunction demonstrated by laboratory tests seems to be a frequent phenomenon

  13. Magnetoimpedance studies on urine treated Co{sub 66}Ni{sub 7}Si{sub 7}B{sub 20} ribbons

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    Kotagiri, Ganesh [Advanced Magnetic Materials Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India); Markandeyulu, G., E-mail: mark@iitm.ac.in [Advanced Magnetic Materials Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India); Doble, Mukesh; Nandakumar, V. [Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036 (India)

    2015-11-15

    Magnetoimpedance (MI) response of Co{sub 66}Ni{sub 7}Si{sub 7}B{sub 20} ribbons treated with artificial urine with protein bovine serum albumin (BSA), artificial urine without protein BSA and healthy male urine was studied as a function of time of incubation. The maximum MI [(MI){sub m}] values of the ribbons treated with artificial urine without protein (RTAU) after 3 h, 6 h, 12 h and 24 h of incubation are 30% (at 4 MHz), 15% (at 5 MHz), 14% (at 10 MHz) and 8% (at 13 MHz) respectively. On the other hand, the respective (MI){sub m} values of the ribbons treated with artificial urine with protein (RTAUP) are 33% (at 4 MHz), 25% (at 5 MHz), 20% (at 8 MHz) and 15% (12 MHz). However (MI){sub m} values of the ribbons treated with healthy male urine (RTHMU) after 4 h, 5 h, 10 h and 15 h of incubation are 71% (at 3 MHz), 57% (at 3 MHz), 25% (at 6 MHz) and 25% (at 5 MHz), respectively. The saturation magnetization (M{sub s}) values of RTAU after 3 h, 6 h, 12 h and 24 h of incubation are 71 emu/g, 65 emu/g, 63 emu/g and 60 emu/g respectively whereas, the respective M{sub s} values of RTAUP are 73 emu/g, 69 emu/g, 67 emu/g and 64 emu/g. The M{sub s} values of RTHMU after 4 h, 5 h, 10 h and 15 h of incubation are 96 emu/g, 90 emu/g, 75 emu/g and 75 emu/g respectively. The decrease in M{sub s} and (MI){sub m} values in RTAU and RTAUP compared to as-quenched ribbon is related to the amounts of various elements etched out from the ribbons and increased surface roughness. The M{sub s} and (MI){sub m} values of RTHMU are seen to have increased after 4 h and 5 h of incubation, due to strain relaxation through removal of strain developed during rapid quenching of the ribbons. On the other hand, the M{sub s} and (MI){sub m} values of RTHMU after 10 h and 15 h have decreased due to deterioration of the surface of the ribbons and thus, increase in magnetic (surface) anisotropy. The decrease in (MI){sub m} and M{sub S} of RTAU with the time of incubation are more rapid compared to that

  14. Arcing at B{sub 4}C-covered limiters exposed to a SOL-plasma

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    Laux, M. E-mail: michael.laux@ipp.mpg.delaux@ipp.mpg.de; Schneider, W.; Wienhold, P.; Juettner, B.; Huber, A.; Balden, M.; Linke, J.; Kostial, H.; Mayer, M.; Rubel, M.; Herrmann, A.; Pospieszczyk, A.; Jachmich, S.; Schweer, B.; Hildebrandt, D.; Bolt, H

    2003-03-01

    Plasma sprayed B{sub 4}C-layers considered as wall coatings for the W7X stellarator have been studied during and after exposure to TEXTOR and after arcing experiments in vacuum. Arcing through the B{sub 4}C layer occurred favoured by high power fluxes and not restricted to less stable phases. But this arcing implies an especially noisy scrape-off layer (SOL). Instead of moving retrograde in the external magnetic field, the arc spot on the B{sub 4}C-layer sticks to the same location for its whole lifetime. Consequently, the arc erodes the entire B{sub 4}C layer, finally burning down to the Cu substrate. In the neighbourhood of craters the surface contains Cu originating from those craters. This material, hauled to the surface by the arc, is subject to subsequent erosion, transport, and redeposition by the SOL-plasma. The behaviour of arcs on B{sub 4}C is most probably caused by the peculiar temperature dependences of the electrical and heat conductivity of B{sub 4}C.

  15. Magnetic flux structures in RNi{sub 2}B{sub 2}C single crystals in normal and superconducting states

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    Vinnikov, L Ya; Veshchunov, I S [Institute of Solid State Physics, RAS, Chernogolovka, Moscow region 142432 (Russian Federation); Bud' ko, S L; Canfield, P C; Kogan, V G, E-mail: vinnik@issp.ac.r [Ames Laboratory U.S. DOE, Iowa State University, Ames, Iowa 50011 (United States)

    2009-03-01

    RNi{sub 2}B{sub 2}C single crystals, where R = Lu, Y, Er, Ho and Tb have been studied by high-resolution Bitter decoration technique, over the wide range temperatures and magnetic fields up to 2 T. Diverse vortex lattice structures were investigated: transition from triangular to square lattice for LuNi{sub 2}B{sub 2}C single crystals; peculiar vortex structures associated with antiferromagnetic (AFM) and weak-ferromagnetic (WFM) states below T{sub c} for ErNi{sub 2}B{sub 2}C single crystals . In addition, Bitter decoration revealed structures associated with a long range magnetic order in the non-superconducting TbNi{sub 2}B{sub 2}C as well as ErNi{sub 2}B{sub 2}C in the normal but magnetically ordered state.

  16. Tribomechanical behavior of B{sub 4}C{sub p} reinforced Al 359 composites

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    Ramasamy, Deivasigamani; Rathanasamy, Rajasekar [Kongu Engineering College, Tamil Nadu (India). Dept. of Mechanical Engineering; Subramanian, Mohan Kumar; Kaliyannan, Gobinath Velu [PAAVAI Engineering College, Tamil Nadu (India). Dept. of Mechatronics Engineering; Palaniappan, Sathish Kumar [Indian Institute of Technology, Kharagpur, West Bengal (India); Durairaj, Jayanth

    2017-03-01

    n the present investigation, the influence of B{sub 4}C{sub p} particles on the mechanical and tribological behavior of Al 359 composites has been studied. B{sub 4}C{sub p} particle reinforced Al 359 composite samples were prepared by stir casting process. Hardness, tensile strength and wear behavior of the composites were studied and compared with a control specimen. Hardness of B{sub 4}C{sub p} particles reinforced Al 359 matrix increases compared to base matrix due to the presence of the ceramic phase. Coefficient of friction considerably increases with up to 20 wt.-% addition of B{sub 4}C{sub p} in base matrix. Specimens were subjected to wear tests under different load conditions and the following five different wear mechanisms such as wear groove, abrasion, delamination, oxidation and plastic deformation were evaluated. The abrasion results prove the increase in wear resistance of B{sub 4}C{sub p} reinforced composites compared to a control specimen.

  17. Sintering of B{sub 4}C powder obtained by a modified carbo-thermal reaction

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, R.M.; Kazumi, M.H.; Goncalves, D.P.; Melo, F.C.L. [Centro Tecnico Aeroespacial (CTA) - Instituto de Aeronautica e Espaco, Praca Marechal Eduardo Gomes, 50 Campus do CTA - Vila das Acacias, 12228-904 Sao Jose dos Campos-SP (Brazil)

    2005-07-01

    Boron carbide is one of the hardest materials and a highly refractory material that is of great interest for structural, electronic and nuclear applications. B{sub 4}C is commercially manufactured by the carbo-thermal reduction of a mixture of boron oxide (B{sub 2}O{sub 3}) in an batch electric arc furnace process. However the carbo-thermal reaction on the stoichiometric starting composition results an excess carbon residue because of the boron loss in the form of B{sub 2}O{sub 2}. Thus, a modified carbo-thermal reaction is applied with an excess B{sub 2}O{sub 3} to compensate the loss and to obtain stoichiometric powders. The aim of this work is to study the sinterability of this powder with the lower carbon residue acting as sintering additive. Pressureless sintering in the temperatures of 1900 deg. C/30 min and 2100 deg. C/30 min in argon atmosphere were applied. The synthesized powders were analysed by XRD and SEM. Density of 94% of theoretical density was achieved for sample prepared with the powder obtained with 50% B{sub 2}O{sub 3} excess synthesized at 1700 deg. C/15 min. (authors)

  18. Interface interaction in the B{sub 4}C/(Fe-B-C) system

    Energy Technology Data Exchange (ETDEWEB)

    Aizenshtein, M. [Department of Material Engineering, Ben-Gurion University, P.O. Box 653, Beer-Sheva 84105 (Israel); NRC-Negev, P.O. Box 9001, Beer-Sheva 84190 (Israel); Mizrahi, I.; Froumin, N.; Hayun, S.; Dariel, M.P. [Department of Material Engineering, Ben-Gurion University, P.O. Box 653, Beer-Sheva 84105 (Israel); Frage, N. [Department of Material Engineering, Ben-Gurion University, P.O. Box 653, Beer-Sheva 84105 (Israel)], E-mail: nfrage@bgu.ac.il

    2008-11-15

    The wetting behavior in the B{sub 4}C/(Fe-C-B) system was investigated in order to clarify the role of Fe additions on the sinterability of B{sub 4}C. Iron and its alloys with C and B react with the boron carbide substrate and form a reaction zone consisting of a fine mixture of FeB and graphite. The apparent contact angles are relatively low for the alloys with a moderate concentration of the boron and carbon and allow liquid phase sintering to occur in the B{sub 4}C-Fe mixtures. A dilatometric study of the sintering kinetics confirms that liquid phase sintering actually takes place and leads to improved mass transfer. A thermodynamic analysis of the ternary Fe-B-C system allows accounting for the experimental observations.

  19. Proton-induced nanorod melting in a coating obtained from the pulsed laser ablation of W{sub 2}B{sub 5}/B{sub 4}C

    Energy Technology Data Exchange (ETDEWEB)

    Tadadjeu Sokeng, I., E-mail: ifriky@tlabs.ac.za [Department of Electrical, Electronics and Computer Engineering, French South African Institute of Technology/Cape Peninsula University of Technology, Bellville Campus, PO Box 1906, Bellville 7530 (South Africa); Electron Microscopy Unit, University of the Western Cape, Private bag x17, Bellville 7535 (South Africa); Ngom, B.D. [Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, 7129, PO Box 722, Somerset West, Western Cape Province (South Africa); UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Laboratoire de Photonique et de Nanofrabrication, Groupes de physique du Solide et Sciences des Matriaux (GPSSM), Facult des sciences et Techniques, Universit Cheikh Anta Diop de Dakar (UCAD), B.P. 25114 Dakar-Fann, Dakar (Senegal); Cummings, F. [Electron Microscopy Unit, University of the Western Cape, Private bag x17, Bellville 7535 (South Africa); Kotsedi, L. [Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, 7129, PO Box 722, Somerset West, Western Cape Province (South Africa); UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Msimanga, M. [iThemba LABS Gauten, Private Bag 11, WITS 2050, Johannesburg (South Africa); Maaza, M. [Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, 7129, PO Box 722, Somerset West, Western Cape Province (South Africa); UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); and others

    2015-02-01

    Highlights: • Coatings from ablated B{sub 4}C/W{sub 2}B{sub 5} were irradiated with 900 keV protons. • Nanorod clusters were observed to melt and disperse. • Uniformly shaped nanorods were observed to grow. • Lateral diffusion of energy and lateral dispersion of matter were observed. - Abstract: Coatings obtained from pulsed laser ablated W{sub 2}B{sub 5}/B{sub 4}C were irradiated with 900keV protons at fluences ranging from about 1×10{sup 15}protons/cm{sup 2} to about 4×10{sup 15}protons/cm{sup 2}. Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were used to study the resulting structural effects. Clusters of nanorods were observed to disperse and reduce in number with increase in proton fluence. The atomic percentage of constituent elements were observed to vary with proton fluence, both within the nanorods and the film floor. Our results show that the structural effect of proton irradiation on the coating is lateral dispersion of matter.

  20. Serum B/sub 12/ levels in iron definiency anemia

    Energy Technology Data Exchange (ETDEWEB)

    Sagan, L.A.; Ohki, Keiichi

    1964-04-23

    As part of its research program to study the late effects of radiation in survivors of the atomic bombs, the Atomic Bomb Casualty Commission (ABCC) in conjunction with the Japanese National Institute of Health (JNIH), conducts biennial medical examinations on the selected population which comprises the ABCC-JHIN Adult Health Study sample. The patients herein described as Groups 1 and 2 were selected from among those examined in Nagasaki who had had a hemoglobin value of less than 11.0 g/100 ml at examination 2 years previously and who had responded to iron therapy sufficiently to justify a diagnosis of iron deficiency anemia. Almost all were women of child bearing age. The effect of iron therapy on the level of serum B/sub 12/ was investigated. Of 58 patients so studied, 46 showed some rise in post-treatment levels of B/sub 12/. This is evaluated as indicating that gastric secretion of intrinsic factor is depressed in the majority of iron deficient patients.

  1. The thermal properties of amorphous Fe{sub 40}Pd{sub 40}B{sub 20} and Fe{sub 60}Pd{sub 20}B{sub 20} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yuan-Tsung, E-mail: ytchen@yuntech.edu.tw

    2015-07-15

    The thermal stability of FePdB thin films was studied using nonisothermal and isothermal analyses. X-ray diffraction (XRD) patterns indicated that Fe{sub 40}Pd{sub 40}B{sub 20} and Fe{sub 60}Pd{sub 20}B{sub 20} films with thicknesses in the range 25–75 Å were amorphous, whereas Fe{sub 40}Pd{sub 40}B{sub 20} and Fe{sub 60}Pd{sub 20}B{sub 20} films with thicknesses in the range 100–200 Å exhibited a nanocrystalline FePd (111) structure. The crucial glass forming ability index (γ and γ{sub m}) was determined using the differential scanning calorimetry (DSC) results of amorphous FePdB films. The Kissinger formula was applied to calculate the activation energy (Q) of crystallization for determining the resistance of the films to crystallization. Thermal analysis showed that the thermal stability and incubation time of Fe{sub 40}Pd{sub 40}B{sub 20} are more favorable than those of Fe{sub 60}Pd{sub 20}B{sub 20}. - Highlights: • FePdB films were amorphous in the range 25–75 Å. • FePdB films exhibited a FePd (111) structure in the range 100–200 Å. • The crucial glass forming ability index was determined using the DSC. • Kissinger formula was applied to calculate the activation energy of crystallization. • The thermal performance of Fe{sub 40}Pd{sub 40}B{sub 20} is more favorable than Fe{sub 60}Pd{sub 20}B{sub 20}.

  2. Evidence that cytochrome b{sub 5} acts as a redox donor in CYP17A1 mediated androgen synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Duggal, Ruchia [Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL (United States); Liu, Yilin [Department of Chemistry, Marquette University, Milwaukee, WI (United States); Gregory, Michael C.; Denisov, Ilia G. [Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL (United States); Kincaid, James R. [Department of Chemistry, Marquette University, Milwaukee, WI (United States); Sligar, Stephen G., E-mail: s-sligar@illinois.edu [Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL (United States); Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, IL (United States)

    2016-08-19

    Cytochrome P450 17A1 (CYP17A1) is an important drug target for castration resistant prostate cancer. It is a bi-functional enzyme, catalyzing production of glucocorticoid precursors by hydroxylation of pregnene-nucleus, and androgen biosynthesis by a second C−C lyase step, at the expense of glucocorticoid production. Cytochrome b{sub 5} (cyt b{sub 5}) is known to be a key regulator of the androgen synthesis reaction in vivo, by a mechanism that is not well understood. Two hypotheses have been proposed for the mechanism by which cyt b{sub 5} increases androgen biosynthesis. Cyt b{sub 5} could act as an allosteric effector, binding to CYP17A1 and either changing its selective substrate affinity or altering the conformation of the P450 to increase the catalytic rate or decrease unproductive uncoupling channels. Alternatively, cyt b{sub 5} could act as a redox donor for supply of the second electron in the P450 cycle, reducing the oxyferrous complex to form the reactive peroxo-intermediate. To understand the mechanism of lyase enhancement by cyt b{sub 5}, we generated a redox-inactive form of cyt b{sub 5}, in which the heme is replaced with a Manganese-protoporphyrin IX (Mn-b{sub 5}), and investigated enhancement of androgen producing lyase reaction by CYP17A1. Given the critical significance of a stable membrane anchor for all of the proteins involved and the need for controlled stoichiometric ratios, we employed the Nanodisc system for this study. The redox inactive form was observed to have no effect on the lyase reaction, while reactions with the normal heme-iron containing cyt b{sub 5} were enhanced ∼5 fold as compared to reactions in the absence of cyt b{sub 5}. We also performed resonance Raman measurements on ferric CYP17A1 bound to Mn-b{sub 5}. Upon addition of Mn-b{sub 5} to Nanodisc reconstituted CYP17A1, we observed clear evidence for the formation of a b{sub 5}-CYP17A1 complex, as noted by changes in the porphyrin modes and alteration in the proximal

  3. RE{sub 2}B{sub 8}O{sub 15} (RE = La, Pr, Nd). Syntheses of three new rare earth borates isotypic to Ce{sub 2}B{sub 8}O{sub 15}

    Energy Technology Data Exchange (ETDEWEB)

    Glaetzle, Matthias; Hoerder, Gregor J.; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie

    2016-08-01

    The rare earth borates RE{sub 2}B{sub 8}O{sub 15} (RE = La, Pr, Nd) were synthesized in a Walker-type multianvil apparatus under conditions of 5.5 GPa and 1100 C. Starting from the corresponding rare earth oxides and boron oxide, the syntheses yielded crystalline products of all new compounds that allowed crystal structure analyses based on single-crystal X-ray diffraction data for La{sub 2}B{sub 8}O{sub 15} and Nd{sub 2}B{sub 8}O{sub 15}. The compound Pr{sub 2}B{sub 8}O{sub 15} could be characterized via X-ray powder diffractometry. The results show that the new compounds crystallize isotypically to Ce{sub 2}B{sub 8}O{sub 15} in the monoclinic space group P2/c. The infrared spectra of RE{sub 2}B{sub 8}O{sub 15} (RE = La, Pr, Nd) have also been studied.

  4. Integration of the denoising, inpainting and local harmonic B{sub z} algorithm for MREIT imaging of intact animals

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Kiwan [National Institute for Mathematical Sciences, Daejeon (Korea, Republic of); Kim, Hyung Joong; Woo, Eung Je [Department of Biomedical Engineering, Kyung Hee University, Yongin (Korea, Republic of); Lee, Chang-Ock [Department of Mathematical Sciences, KAIST, Daejeon (Korea, Republic of); Seo, Jin Keun, E-mail: ejwoo@khu.ac.k [Department of Computational Science and Engineering, Yonsei University, Seoul (Korea, Republic of)

    2010-12-21

    Conductivity imaging based on the current-injection MRI technique has been developed in magnetic resonance electrical impedance tomography. Current injected through a pair of surface electrodes induces a magnetic flux density distribution inside an imaging object, which results in additional magnetic field inhomogeneity. We can extract phase changes related to the current injection and obtain an image of the induced magnetic flux density. Without rotating the object inside the bore, we can measure only one component B{sub z} of the magnetic flux density B = (B{sub x}, B{sub y}, B{sub z}). Based on a relation between the internal conductivity distribution and B{sub z} data subject to multiple current injections, one may reconstruct cross-sectional conductivity images. As the image reconstruction algorithm, we have been using the harmonic B{sub z} algorithm in numerous experimental studies. Performing conductivity imaging of intact animal and human subjects, we found technical difficulties that originated from the MR signal void phenomena in the local regions of bones, lungs and gas-filled tubular organs. Measured B{sub z} data inside such a problematic region contain an excessive amount of noise that deteriorates the conductivity image quality. In order to alleviate this technical problem, we applied hybrid methods incorporating ramp-preserving denoising, harmonic inpainting with isotropic diffusion and ROI imaging using the local harmonic B{sub z} algorithm. These methods allow us to produce conductivity images of intact animals with best achievable quality. We suggest guidelines to choose a hybrid method depending on the overall noise level and existence of distinct problematic regions of MR signal void.

  5. Influence of ligand coordination of cobalt ions on structural properties of ZnO-ZnF{sub 2}-B{sub 2}O{sub 3} glass system by means of spectroscopic studies

    Energy Technology Data Exchange (ETDEWEB)

    Naresh, P.; Naga Raju, G. [Department of Physics, Acharya Nagarjuna University-Nuzvid Campus, Nuzvid 521201, A.P. (India); Srinivasa Rao, Ch. [Department of Physics, Andhra Loyola College, Vijayawada 520008, A.P. (India); Prasad, S.V.G.V.A. [Department of Physics, Andhra Jateeya Kalasala, Machilipatnam 520001, A.P. (India); Ravi Kumar, V. [Department of Physics, Acharya Nagarjuna University-Nuzvid Campus, Nuzvid 521201, A.P. (India); Veeraiah, N., E-mail: nvr8@rediffmail.com [Department of Physics, Acharya Nagarjuna University-Nuzvid Campus, Nuzvid 521201, A.P. (India)

    2012-02-15

    The glasses of the composition 10ZnO-30ZnF{sub 2}-60B{sub 2}O{sub 3} doped with different concentrations of CoO were prepared. Differential scanning calorimetric (DSC) studies, optical absorption, photoluminescence and infrared spectra of these glasses have been carried out. DSC studies have indicated that the resistance of the glass against devitrification increases with the increase in the concentration of CoO. Optical absorption spectra have exhibited one octahedral band due to {sup 4}T{sub 1g}(F){yields}{sup 2}T{sub 1g}(H) and two tetrahedral bands due to {sup 4}A{sub 2}({sup 4}F){yields}{sup 4}T{sub 1}({sup 4}P) {sup 4}A{sub 2}({sup 4}F){yields}{sup 4}T{sub 1}({sup 4}F) transitions of Co{sup 2+} ions at about 525, 570 and 1400 nm, respectively. As the concentration of CoO is increased the tetrahedral bands are observed to grow at the expense of octahedral band. The luminescence spectra have exhibited two emission bands in the spectral regions of 600-700 nm and 800-900 nm due to {sup 4}T{sub 1}({sup 4}P){yields}{sup 4}A{sub 2}({sup 4}F) and {sup 4}T{sub 1}({sup 4}P){yields}{sup 4}T{sub 2}({sup 4}F) tetrahedral transitions of Co{sup 2+} ions, respectively. With the increasing content of cobalt ions in the glass matrix, the half width and intensity of these bands are observed to increase. The analysis of the results of these two spectra coupled with IR spectra has indicated that as the concentration of CoO is increased in the glass matrix, the tetrahedral occupancy of cobalt ions dominates over the octahedral occupancy and increase the rigidity of the glass network.

  6. Low-temperature heat capacity and thermodynamic functions of vitamin B{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Knyazev, A.V., E-mail: knyazevav@gmail.com; Smirnova, N.N.; Plesovskikh, A.S.; Shushunov, A.N.; Knyazeva, S.S.

    2014-04-01

    Graphical abstract: - Highlights: • Temperature dependence of heat capacity of vitamin B{sub 12} has been measured by precision adiabatic vacuum calorimetry. • The thermodynamic functions of the vitamin B{sub 12} have been determined for the range from T → 0 to 343 K. • The character of heterodynamics of structure was detected. • The thermal stability of cyanocobalamin was studied by differential scanning calorimetry. - Abstract: In the present work temperature dependence of heat capacity of vitamin B{sub 12} (cyanocobalamin) has been measured for the first time in the range from 6 to 343 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B{sub 12}, namely, the heat capacity, enthalpy H°(T) − H°(0), entropy S°(T) − S°(0) and Gibbs function G°(T) − H°(0) have been determined for the range from T → 0 to 343 K. The value of the fractal dimension D in the function of multifractal generalization of Debye's theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. The thermal stability of cyanocobalamin was also studied by differential scanning calorimetry.

  7. B{sub s}π-B anti K interactions in finite volume and X(5568)

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jun-Xu; Geng, Li-Sheng [Beihang University, School of Physics and Nuclear Energy Engineering, International Research Center for Nuclei and Particles in the Cosmos, Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beijing (China); Ren, Xiu-Lei [Peking University, State Key Laboratory of Nuclear Physics and Technology, School of Physics, Beijing (China)

    2017-02-15

    The recent observation of X(5568) by the D0 Collaboration has aroused a lot of interest both theoretically and experimentally. In the present work, we first point out that X(5568) and D{sub s0}{sup *}(2317) cannot simultaneously be of molecular nature, from the perspective of heavy-quark symmetry and chiral symmetry, based on a previous study of the lattice QCD scattering lengths of DK and its coupled channels. Then we compute the discrete energy levels of the B{sub s}π and B anti K system in finite volume using unitary chiral perturbation theory. The comparison with the latest lattice QCD simulation, which disfavors the existence of X(5568), supports our picture where the B{sub s}π and B anti K interactions are weak and X(5568) cannot be a B{sub s}π and B anti K molecular state. In addition, we show that the extended Weinberg compositeness condition also indicates that X(5568) cannot be a molecular state made from B{sub s}π and B anti K interactions. (orig.)

  8. Ab Initio MO study on the nucleophilic oxirane ring opening of exo and endo Aflatoxin B{sub 1} 8,9-Oxide; Ekiso oyobi endo Aflatoxin B{sub 1} 8,9-Oxide no kyukaku kaikan hanno ni taisuru Ab Initio ho ni yoru kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Okajima, Toshiya; Hashikawa, Akane [Saga University, Saga (Japan). Department of Chemistry

    1999-08-10

    The difference of the reactivity for S{sub N}2 type oxirane ring opening of exo and endo Aflatoxin B{sub 1} (AFB{sub 1}) 8,9-oxide (exo-1 and endo-1, respectively) was analyzed with ab initio molecular orbital theory. All stationary points including transition-state structures were optimized with no geometry constraint at the RHF/3-21G basis set, and energies were evaluate at Becke3LYP/3-21G level based on the RHF/3-21G geometries. The calculation clarified the following three points: (1) the activation energy ({delta}E{sup {ne}}) for endo attacking of NH{sub 3} molecule (the reaction with exo derivatives containing exo-1) is considerably smaller than those for exo attacking (the reaction with endo ones containing endo-1), (2) the reactivity for nucleophilic oxirane ring opening is controlled by the distortion of LUMO{sub C-O} of oxirane ring, which is probably caused by exo/endo relationship between oxirane ring and five-membered dihydrofurano ring (B) with respect to A ring, and (3) the remaining part (inclusing coumarin skeleton) of AFB{sub 1} oxid has little influence on the geometry around the reaction center and the activation energy. (author)

  9. Serum thymidine kinase in vitamin B/sub 12/ deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Hagberg, H.; Gronowitz, S.; Killander, A.; Kaellander, C. (University Hospital, Uppsala, Sweden)

    1984-01-01

    In DNA synthesis deoxythymidine kinase (TK) catalyses the conversion of deoxythymidine to deoxythymidine monophosphate (dTMP) via the 'salvage pathway'. Serum deoxythymidine kinase (S=TK) was measured in this study in 75 patients with vitamin B/sub 12/ deficiency by a new, very sensitive method, using /sup 125/I-deoxyuridine as substrate. Elevated S-TK levels were found in those patients who had developed haemolysis and anaemia and the more advanced the disease the higher the S-TK value. Thus there was a highly significant correlation between S-TK, haemoglobin level and lactic dehydrogenase activity. These findings are consistent with the theory that elevated levels of S-TK are due to release from unstable proliferating tissue.

  10. Reaction between B{sub 4}C and austenitic stainless steel in oxidizing atmosphere at temperatures below 1673 K

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Ryosuke; Ueda, Shigeru, E-mail: tie@tagen.tohokku.ac.jp; Kim, Sun-Joong; Gao, Xu; Kitamura, Shin-ya

    2015-11-15

    Synopsis: The control rod of a light water nuclear reactor is constructed of a pole comprising stainless steel filled with a boron carbide (B{sub 4}C) core. To appraise the stability of this control rod in the event of a severe accident, the reactions of the system of B{sub 4}C and grade 304 austenitic stainless steel (SS) were observed at 1473 K in Ar, air, and a mixture of both. To clarify the reaction mechanism and the influence of the oxygen partial pressure, the weight change ratio was monitored and differential thermal analysis was performed at the temperature range from room temperature to 1673 K to monitor the reaction under controlled oxygen partial pressure. The results showed that there was no direct reaction between B{sub 4}C and SS. When the temperature was higher than the melting point of B{sub 2}O{sub 3} (743 K), the molten B{sub 2}O{sub 3} formed by oxidation of B{sub 4}C covered the surface of SS by spreading wetting. This B{sub 2}O{sub 3} layer functioned to transport oxygen from the atmosphere to SS, leading to accelerated oxidation of SS. As a result, a Fe–Cr–Ni–B–O oxide phase covered the surface of SS. Oxygen continuously entered the oxide phase with prolonged reaction time, and oxides such as Fe{sub 2}O{sub 3}, Fe{sub 3}O{sub 4}, and FeOx–Cr{sub 2}O{sub 3} were found on the outer layer. Therefore, in the presence of B{sub 2}O{sub 3} formed by oxidation of B{sub 4}C, the oxidation of SS was accelerated below the eutectic temperature of the Fe–C system. - Highlights: • The reactions of the system of B{sub 4}C and grade 304 austenitic stainless steel (SS) were studied at 1473 K. • The molten B{sub 2}O{sub 3} formed by oxidation of B{sub 4}C covered the surface of SS by spreading wetting at the temperature above 743 K. • In the presence of B{sub 2}O{sub 3}, the oxidation of SS was accelerated.

  11. Ab-initio study of B{sub 2}-type technetium AB (A=Tc, B=Nb and Ta) intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Acharya, Nikita, E-mail: acharyaniks30@gmail.com; Fatima, Bushra; Sanyal, Sankar P. [Department of Physics, Barkatullah University, Bhopal, 462026 (India)

    2016-05-06

    The structural, electronic and elastic properties of AB type (A = Tc, B = Nb and Ta) technetium intermetallic compounds are studied using full potential linearized plane wave (FP-LAPW) method within generalized gradient approximation (GGA). The calculated lattice parameters agree well with the experimental results. The elastic constants obey the stability criteria for cubic system. Ductility for these compounds has been analyzed using the Pugh’s rule and Cauchy’s pressure and found that all the compounds are ductile in nature. Bonding nature is discussed in terms of Fermi surface and band structures.

  12. Synthesis and characterization of thermoluminescent Li{sub 2}B{sub 4}O{sub 7} nanophosphor

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Lakhwant, E-mail: lakhwant@yahoo.co [Department of Physics, Guru Nanak Dev University, Amritsar, Punjab 143005 (India); Chopra, Vibha [Department of Physics, Guru Nanak Dev University, Amritsar, Punjab 143005 (India); Lochab, S.P. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, PostBox 10502, New Delhi 110067 (India)

    2011-06-15

    Lithium borate (Li{sub 2}B{sub 4}O{sub 7}) is a low Z{sub eff}, tissue equivalent material that is commonly used for medical dosimetry using the thermoluminescence (TL) technique. Nanocrystals of lithium borate were synthesized by the combustion method for the first time in the laboratory. TL characteristics of the synthesized material were studied and compared with those of commercially available microcrystalline Li{sub 2}B{sub 4}O{sub 7}. The optimum pre-irradiation annealing condition was found to be 300 {sup o}C for 10 min and that of post-irradiation annealing was 300 {sup o}C for 30 min. The synthesized Li{sub 2}B{sub 4}O{sub 7} nanophosphor has very poor sensitivity for low doses of gamma up to 10{sup 1} Gy whereas from 10{sup 1} to 4.5x10{sup 2} Gy this phosphor exhibits a linear response and then from 4.5x10{sup 2} to 10{sup 3} Gy it shows supralinearity. Thermoluminescence properties of Li{sub 2}B{sub 4}O{sub 7} nanophosphor doped with Cu has also been investigated in this paper. It shows low fading and a linear response over a wide range of gamma radiation from 1x10{sup 2} to 5x10{sup 3} Gy. Therefore the synthesized lithium borate nanophosphor doped with Cu may be used for high dose measurements of gamma radiations. - Highlights: {yields} Current paper deals with the synthesis of nanocrystalline Li{sub 2}B{sub 4}O{sub 7} using the combustion method. {yields} Its TL properties are compared to that of commercially available microcrystalline Li{sub 2}B{sub 4}O{sub 7}. {yields} The effect of Cu doping on TL properties of Li{sub 2}B{sub 4}O{sub 7} nanophosphor is also discussed.

  13. Measurement of the B{sub S} lifetime

    Energy Technology Data Exchange (ETDEWEB)

    Siccama, I.

    1996-10-07

    This thesis presents a measurement of the B{sub s} lifetime using 3 million hadronic Z decays collected by the DELPHI detector at LEP from 1991 to 1994. Decays of B{sub s} mesons are tagged by the reconstruction of a D{sub s}{sup -}{yields}{phi}{pi}{sup -}or D{sub s}{sup -}{yields}K{sup *0}K{sup -} decay (including the charge conjugated states of these decay modes). The decay time is obtained by reconstructing both the B{sub s} momentum and the B{sub s} flight distance. The combined result for the D{sub s}-lepton and D{sub s}-hadron samples is: {tau}(B{sub s})=1.54{+-}0.31{+-}0.15 ps where the first error is statistical and the second is systematic. (orig./HSI).

  14. Latest B{sub s} mixing results from ALEPH

    Energy Technology Data Exchange (ETDEWEB)

    Coyle, P. [Centre de Physique des Particules de Marseille (France)

    2001-07-01

    B{sub s} mixing results from the ALEPH experiment, based on analysis of about 4M Z{sup 0} decays at LEP are presented. Three recently updated analyses; fully reconstructed B{sub s}, D{sub s}-lepton and inclusive-lepton are discussed. The combination of all three analyses yields {delta}m{sub s}>10.6 ps{sup -1} at 95% CL, with a sensitivity of 12.8 ps{sup -1}. (author)

  15. Electroweak penguins in isospin-violating B{sub s} decays

    Energy Technology Data Exchange (ETDEWEB)

    Hofer, Lars; Scherer, Dominik [Karlsruher Institut fuer Technologie (Germany); Vernazza, Leonardo [Johannes-Gutenberg-Universitaet Mainz (Germany)

    2010-07-01

    During the last decade, experimental data from B{yields}K{pi} decays has caused many discussions about deviations from Standard Model predictions and their possible explanation by New Physics. In particular, models which allow for enhanced electroweak penguins have been investigated in this context since they allow for sizeable isospin-violating effects. We study the consequences of such enhanced electroweak penguins in the purely isospin-violating decays B{sub s}{yields}{phi}{pi} and B{sub s}{yields}{phi}{rho}. The branching fractions of these modes are highly sensitive to New Physics in EW penguins and are thus an interesting topic for LHCb and super-B-factories, complementary to precise B{yields}K{pi} measurements.

  16. Electroweak penguins in isospin-violating B{sub s} decays

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, Dominik; Hofer, Lars [Karlsruhe Institute of Technology - KIT, P.O. Box 3640, 76021 Karlsruhe (Germany); Vernazza, Leonardo [Institut fuer Physik - WA THEP, Johannes-Gutenberg-Universitaet, 55099 Mainz (Germany)

    2010-07-01

    During the last decade, experimental data from B {yields} K {pi} decays has caused many discussions about deviations from Standard Model predictions and their possible explanation by New Physics. In particular, models which allow for enhanced electroweak penguins have been investigated in this context since they allow for sizeable isospin-violating effects. We study the consequences of such enhanced electroweak penguins in the purely isospin-violating decays B{sub s} {yields} {phi} {rho} and B{sub s} {yields} {phi} {pi}. The branching fractions of these modes are highly sensitive to New Physics in EW penguins and are thus an interesting topic for LHCb and Super-B-factories, complementary to precise B {yields} K {pi} measurements. (author)

  17. Carbon ion induced DNA double-strand breaks in melanophore B{sub 16}

    Energy Technology Data Exchange (ETDEWEB)

    Wei Zengquan; Zhou Guangming; Wang Jufang; He Jing; Li Qiang; Li Wenjian; Xie Hongmei; Cai Xichen; Tao Huang; Dang Bingrong; Han Guangwu [Chinese Academy of Sciences, Lanzhou (China). Inst. of Modern Physics; Gao Qingxiang [Lanzhou Univ. (China)

    1997-09-01

    DNA double-strand breaks (DSBs) in melanophore B{sub 16} induced by plateau and extended Bragg peak of 75 MeV/u {sup 12}C{sup 6+} ions were studied by using a technique of inverse pulsed-field gel electrophoresis (PIGE). DNA fragment lengths were distributed in two ranges: the larger in 1.4 Mbp-3.2 Mbp and the smaller in less than 1.2 Mbp. It indicates that distribution of DNA fragments induced by heavy ion irradiation is not stochastic and there probably are sensitive sites to heavy ions in DNA molecules of B{sub 16}. Percentage of DNA released from plug (PR) increased and trended towards a quasi-plateau {proportional_to}85% as dose increased. Content of the larger fragments decreased and flattened with increasing dose while content of the smaller ones increased and trended towards saturation. (orig.)

  18. Structural and optical study of B{sub x}In{sub y}Ga{sub 1-x-y}As/GaAs and In{sub y}Ga{sub 1-y}As/GaAs QW's grown by MOCVD

    Energy Technology Data Exchange (ETDEWEB)

    Saidi, F., E-mail: faouzi.saidi@fsm.rnu.t [Laboratoire de Physique des Semiconducteurs et des Composants Electroniques, Faculte des Sciences de Monastir, Avenue de l' Environnement, 5000 Monastir (Tunisia); Hamila, R.; Maaref, H. [Laboratoire de Physique des Semiconducteurs et des Composants Electroniques, Faculte des Sciences de Monastir, Avenue de l' Environnement, 5000 Monastir (Tunisia); Rodriguez, Ph.; Auvray, L.; Monteil, Y. [Laboratoire Multimateriaux et Interfaces. Universite Claude Bernard Lyon 1 43, Boulevard du 11 Novembre 1918 (France)

    2010-02-18

    Structural and optical studies of In{sub y}Ga{sub 1-y}As/GaAs and B{sub x}In{sub y}Ga{sub 1-x-y}As/GaAs quantum wells, grown by Metal Organic Chemical Vapor Deposition (MOCVD), with the same indium composition, have been achieved by High-resolution X-ray Diffraction (HRXRD) and Photoluminescence spectroscopy (PL). An important fraction of indium (36%) has been incorporated into GaAs and BGaAs confirmed the growth conditions. The strain effects have been reduced by In incorporation into BGaAs which show that a B{sub x}In{sub y}Ga{sub 1-x-y}As can be grown lattice-matched to GaAs. It has been shown that the BInGaAs PL band shifts significantly to low energy side (of a bout 50 meV) compared to InGaAs. The temperature dependence of the BInGaAs PL peak energy has shown an abnormal behavior. Based on these experimental results, we have suggested that the carrier recombination mechanisms in the BInGaAs QWs result from exciton-localization like mode. These results are attributed to the localized states induced by the clustering and the non-uniform insertion of boron atoms in BInGaAs QW.

  19. Disposable pencil graphite electrode modified with peptide nanotubes for Vitamin B{sub 12} analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pala, Betül Bozdoğan [Nanotechnology and Nanomedicine Division, Institute of Science, Hacettepe University, 06800 Ankara (Turkey); Vural, Tayfun [Department of Chemistry, Faculty of Science, Hacettepe University, 06800 Beytepe, Ankara (Turkey); Kuralay, Filiz [Department of Chemistry, Faculty of Science and Arts, Ordu University, 52200 Ordu (Turkey); Çırak, Tamer [Nanotechnology and Nanomedicine Division, Institute of Science, Hacettepe University, 06800 Ankara (Turkey); Bolat, Gülçin; Abacı, Serdar [Department of Chemistry, Faculty of Science, Hacettepe University, 06800 Beytepe, Ankara (Turkey); Denkbaş, Emir Baki, E-mail: denkbas@hacettepe.edu.tr [Department of Chemistry, Faculty of Science, Hacettepe University, 06800 Beytepe, Ankara (Turkey)

    2014-06-01

    In this study, peptide nanostructures from diphenylalanine were synthesized in various solvents with various polarities and characterized with Scanning Electron Microscopy (SEM) and Powder X-ray Diffraction (PXRD) techniques. Formation of peptide nanofibrils, nanovesicles, nanoribbons, and nanotubes was observed in different solvent mediums. In order to investigate the effects of peptide nanotubes (PNT) on electrochemical behavior of disposable pencil graphite electrodes (PGE), electrode surfaces were modified with fabricated peptide nanotubes. Electrochemical activity of the pencil graphite electrode was increased with the deposition of PNTs on the surface. The effects of the solvent type, the peptide nanotube concentration, and the passive adsorption time of peptide nanotubes on pencil graphite electrode were studied. For further electrochemical studies, electrodes were modified for 30 min by immobilizing PNTs, which were prepared in water at 6 mg/mL concentration. Vitamin B{sub 12} analyses were performed by the Square Wave (SW) voltammetry method using modified PGEs. The obtained data showed linearity over the range of 0.2 μM and 9.50 μM Vitamin B{sub 12} concentration with high sensitivity. Results showed that PNT modified PGEs were highly simple, fast, cost effective, and feasible for the electro-analytical determination of Vitamin B{sub 12} in real samples.

  20. Radiolysis of cyanocobalamin (vitamin B{sub 12})

    Energy Technology Data Exchange (ETDEWEB)

    Juanchi, X.; Albarran, G.; Negron-Mendoza, A

    2000-03-01

    Research on the radiolysis of vitamins is of considerable interest since these compounds are important nutritional constituents in foods and in dietetic supplements. In spite of these considerations there are few data and very often difficult to compare for the radiolytic behavior of vitamins. In this work we focused our attention on to the study of the radiolysis of cyanocobalamin (vitamin B{sub 12}) in solid state and in aqueous solutions. The procedure was followed by HPLC and UV-spectroscopy. The results obtained in aqueous solutions showed a dependence of the decomposition as a linear function of the dose. The G of decomposition for a 1x10{sup -5} M solution was 3.3. In the solid state the vitamin was very stable towards the irradiation in the conditions used in this study with a G=2.1x10{sup -3}. A study made with Serratia marcescens as a microbiological contaminant showed that at the sterilization dose there is a destruction of the vitamin in aqueous solution. In the solid state the degree of decomposition was 7%. (author)

  1. Magnetic structure of the magnetocaloric compound AlFe{sub 2}B{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Cedervall, Johan, E-mail: johan.cedervall@kemi.uu.se [Department of Chemistry – Ångström Laboratory, Uppsala University, Box 538, 751 21 Uppsala (Sweden); Andersson, Mikael Svante; Sarkar, Tapati [Department of Engineering Sciences, Uppsala University, Box 534, 751 21 Uppsala (Sweden); Delczeg-Czirjak, Erna K. [Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala (Sweden); Bergqvist, Lars [Department of Materials and Nano Physics and Swedish e-Science Research Centre (SeRC), Royal Institute of Technology (KTH), Electrum 229, SE-164 40 Kista (Sweden); Hansen, Thomas C. [Institut Laue-Langevin, B.P. 156, Grenoble Cedex 9, 38042 France (France); Beran, Premysl [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Rez, 25068 Czech Republic (Czech Republic); Nordblad, Per [Department of Engineering Sciences, Uppsala University, Box 534, 751 21 Uppsala (Sweden); Sahlberg, Martin [Department of Chemistry – Ångström Laboratory, Uppsala University, Box 538, 751 21 Uppsala (Sweden)

    2016-04-15

    The crystal and magnetic structures of AlFe{sub 2}B{sub 2} have been studied with a combination of X-ray and neutron diffraction and electronic structure calculations. The magnetic and magnetocaloric properties have been investigated by magnetisation measurements. The samples have been produced using high temperature synthesis and subsequent heat treatments. The compound crystallises in the orthorhombic crystal system Cmmm and it orders ferromagnetically at 285 K through a second order phase transition. At temperatures below the magnetic transition the magnetic moments align along the crystallographic a-axis. The magnetic entropy change from 0 to 800 kA/m was found to be −1.3 J/K kg at the magnetic transition temperature. - Graphical abstract: The magnetic structure of AlFe{sub 2}B{sub 2} has been investigated using neutron diffraction and the magnetic spins have been found to align ferromagnetically along the crystallographic a-axis. - Highlights: • The crystal and magnetic structures of AlFe{sub 2}B{sub 2} have been studied. • Orders ferromagnetically at 285 K via a second order phase transition. • The magnetic moments are found to be aligned along the crystallographic a-axis. • The magnetic entropy change from 0 to 800 kA/m was found to be −1.3 J/K kg.

  2. The B{sub c} → ψ(2S)π, η{sub c}(2S)π decays in the perturbative QCD approach

    Energy Technology Data Exchange (ETDEWEB)

    Rui, Zhou; Wang, Guang-xin; Song, Li-hua [North China University of Science and Technology, College of Sciences, Tangshan (China); Wang, Wen-Fei [Shanxi University, Department of Physics and Institute of Theoretical Physics, Taiyuan, Shanxi (China); Chinese Academy of Sciences, Center for Future High Energy Physics, Institute of High Energy Physics, Beijing (China); Lue, Cai-Dian [Chinese Academy of Sciences, Center for Future High Energy Physics, Institute of High Energy Physics, Beijing (China)

    2015-06-15

    Nonleptonic two-body B{sub c} decays including radially excited ψ(2S) or η{sub c}(2S) mesons in the final state are studied using the perturbative QCD approach based on k{sub T} factorization. The charmonium distribution amplitudes are extracted from the n = 2, l = 0 Schroedinger states for the harmonic oscillator potential. Utilizing these distribution amplitudes, we calculate the numerical results of the B{sub c} → ψ(2S), η{sub c}(2S) transition form factors and branching fractions of B{sub c} → ψ(2S)π, η{sub c}(2S)π decays. The ratio between two decay modes B{sub c} → ψ(2S)π and B{sub c} → J/ψπ is compatible with the experimental data within uncertainties, which indicates that the harmonic-oscillator wave functions for ψ(2S) and η{sub c}(2S)(2S) work well. It is found that the branching fraction of B{sub c} → η{sub c}(2S)π, which is dominated by the twist-3 charmonium distribution amplitude, can reach the order of 10{sup -3}. We hope it can be measured soon in the LHCb experiment. (orig.)

  3. Structural modifications induced by ion irradiation and temperature in boron carbide B{sub 4}C

    Energy Technology Data Exchange (ETDEWEB)

    Victor, G., E-mail: g.victor@ipnl.in2p3.fr [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Pipon, Y.; Bérerd, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Institut Universitaire de Technologie (IUT) Lyon-1, Université Claude Bernard Lyon 1, 69622 Villeurbanne Cedex (France); Toulhoat, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); CEA-DEN, Saclay, 91191 Gif-sur-Yvette (France); Moncoffre, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Djourelov, N. [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, 72 Tzarigradsko chaussee blvd, BG-1784 Sofia (Bulgaria); ELI-NP, IFIN-HH, 30 Reactorului Str, MG-6 Bucharest-Magurele (Romania); Miro, S. [CEA-DEN, Service de Recherches de Métallurgie Physique, Laboratoire JANNUS, F-91191 Gif-sur-Yvette (France); Baillet, J. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Pradeilles, N.; Rapaud, O.; Maître, A. [SPCTS, UMR CNRS 7315, Centre Européen de la céramique, University of Limoges (France); Gosset, D. [CEA, Saclay, DMN-SRMA-LA2M, 91191 Gif-sur-Yvette (France)

    2015-12-15

    Already used as neutron absorber in the current French nuclear reactors, boron carbide (B{sub 4}C) is also considered in the future Sodium Fast Reactors of the next generation (Gen IV). Due to severe irradiation conditions occurring in these reactors, it is of primary importance that this material presents a high structural resistance under irradiation, both in the ballistic and electronic damage regimes. Previous works have shown an important structural resistance of boron carbide even at high neutron fluences. Nevertheless, the structural modification mechanisms due to irradiation are not well understood. Therefore the aim of this paper is to study structural modifications induced in B{sub 4}C samples in different damage regimes. The boron carbide pellets were shaped and sintered by using spark plasma sintering method. They were then irradiated in several conditions at room temperature or 800 °C, either by favoring the creation of ballistic damage (between 1 and 3 dpa), or by favoring the electronic excitations using 100 MeV swift iodine ions (S{sub e} ≈ 15 keV/nm). Ex situ micro-Raman spectroscopy and Doppler broadening of annihilation radiation technique with variable energy slow positrons were coupled to follow the evolution of the B{sub 4}C structure under irradiation.

  4. Thermoluminescence characteristics of gamma irradiated Li{sub 2}B{sub 4}O{sub 7}:Cu nanophosphor

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, Vibha [Department of Physics, Guru Nanak Dev University, Amritsar, Punjab 143005 (India); Singh, Lakhwant, E-mail: lakhwant@yahoo.com [Department of Physics, Guru Nanak Dev University, Amritsar, Punjab 143005 (India); Lochab, S.P. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, PostBox 10502, New Delhi 110067 (India)

    2013-07-21

    Nanocrystals of the Li{sub 2}B{sub 4}O{sub 7}:Cu were synthesized by the combustion method using different concentrations of Cu. X-ray diffraction (XRD) spectra and transmission electron microscopy (TEM) image confirm the nanometric size of synthesized material. The thermal stability of phosphor was obtained by thermogravimetric analysis (TGA). TL characteristics of the synthesized Li{sub 2}B{sub 4}O{sub 7}:Cu material doped with Cu of concentrations 1000 ppm and 2500 ppm were studied. It is observed that Li{sub 2}B{sub 4}O{sub 7}:Cu doped with Cu (both 1000 ppm and 2500 ppm) exhibit a linear response in the range 1×10{sup 0}–5×10{sup 3} Gy of gamma radiations. Finally the trapping parameters associated with the glow peaks were calculated using the glow curve deconvolution (GCD) glow fit method. Fading and reproducibility of phosphors were also studied and it was found that the Li{sub 2}B{sub 4}O{sub 7}:Cu is quite suitable for radiation dosimetry. -- Highlights: • The synthesis of Nanocrystalline Li2B4O7:Cu using the combustion method. • TL properties of samples doped with Cu of concentration 1000 and 2500 ppm are studied. • The trapping parameters of Li2B4O7:Cu nanophosphor are also calculated.

  5. Comparison of B{sub 2}O{sub 3} and BN deposited by atomic layer deposition for forming ultrashallow dopant regions by solid state diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Consiglio, Steven, E-mail: steve.consiglio@us.tel.com; Clark, Robert D.; O' Meara, David; Wajda, Cory S.; Tapily, Kandabara; Leusink, Gert J. [TEL Technology Center, America, LLC, 255 Fuller Rd., Albany, New York 12203 (United States)

    2016-01-15

    In this study, the authors investigated atomic layer deposition (ALD) of B{sub 2}O{sub 3} and BN for conformal, ultrashallow B doping applications and compared the effect of dopant-containing overlayers on sheet resistance (R{sub s}) and B profiles for both types of films subjected to a drive-in thermal anneal. For the deposition of B{sub 2}O{sub 3}, tris(dimethylamido)borane and O{sub 3} were used as coreactants and for the deposition of BN, BCl{sub 3} and NH{sub 3} were used as coreactants. Due to the extreme air instability of B{sub 2}O{sub 3} films, physical analysis was performed on B{sub 2}O{sub 3} films, which were capped in-situ with ∼30 Å ALD grown Al{sub 2}O{sub 3} layers. For the BN films, in-situ ALD grown Si{sub 3}N{sub 4} capping layers (∼30 Å) were used for comparison. From spectroscopic ellipsometry, a thickness decrease was observed after 1000 °C, 30 s anneal for the B{sub 2}O{sub 3} containing stack with 60 ALD cycles of B{sub 2}O{sub 3}, whereas the BN containing stacks showed negligible thickness decrease after the annealing step, regardless of the number of BN cycles tested. The postanneal reduction in film thickness as well as decrease in R{sub s} for the B{sub 2}O{sub 3} containing stack suggests that the solid state diffusion dopant mechanism is effective, whereas for the BN containing stacks this phenomenon seems to be suppressed. Further clarification of the effectiveness of the B{sub 2}O{sub 3} containing layer compared to the film stacks with BN was evidenced in backside secondary ion mass spectrometry profiling of B atoms. Thus, B{sub 2}O{sub 3} formed by an ALD process and subsequently capped in-situ followed by a drive-in anneal offers promise as a dopant source for ultrashallow doping, whereas the same method using BN seems ineffective. An integrated approach for B{sub 2}O{sub 3} deposition and annealing on a clustered tool also demonstrated controllable R{sub s} reduction without the use of a capping layer.

  6. Spin conversion of cytochrome b{sub 559} in photosystem II induced by exogenous high potential quinone

    Energy Technology Data Exchange (ETDEWEB)

    Kropacheva, Tatyana N.; Feikema, W. Onno; Mamedov, Fikret; Feyziyev, Yashar; Styring, Stenbjorn; Hoff, Arnold J

    2003-11-01

    The spin-state of cytochrome b{sub 559} (Cyt b{sub 559}) was studied in photosystem II (PSII) membrane fragments by low-temperature EPR spectroscopy. Treatment of the membranes with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) converts the native low-spin (LS) form of Cyt b{sub 559} to the high-spin (HS) form characterized with the g= 6.19 and g= 5.95 split signal. The HS Cyt b{sub 559} was pH dependent with the amplitude increasing toward more acidic pH values (pH 5.5-8.5). The HS state was not photochemically active upon 77 and 200 K continuous illumination under our conditions and was characterized by a low reduction potential ({<=}0 V). It was also demonstrated that DDQ treatment damages the oxygen evolving complex, leading to inhibition of oxygen evolution, decrease of the S{sub 2}-state EPR multiline signal and release of Mn{sup 2+}. In parallel, studies of model systems containing iron(III) protoporphyrin IX chloride (Fe{sup III}Por), which is a good model compound for the Cyt b{sub 559} prosthetic group, were performed by using optical and EPR spectroscopy. The interaction of Fe{sup III}Por with imidazole (Im) in weakly polar solvent results in formation of bis-imidazole coordinated heme iron (Fe{sup III}Por Im{sub 2}) which mimic the bis-histidine axial ligation of Cyt b{sub 559}. The reaction of DDQ with the LS Fe{sup III}Por Im{sub 2} complex leads to its transformation into the HS state (g{sub perpendicular}=5.95, g{sub parallel}=2.00). It was shown that the spin conversion occurs due to the donor-acceptor interaction of coordinated imidazole with this high-potential quinone causing the displacement of imidazole from the axial position. The similar mechanism of DDQ-induced spin change is assumed to be valid for the native membrane Cyt b{sub 559} in PSII centers.

  7. Thermoluminescence and radioluminescence properties of tissue equivalent Cu-doped Li{sub 2}B{sub 4}O{sub 7} for radiation dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Cruz Z, E.; Furetta, C. [UNAM, Instituto de Ciencias Nucleares, Apdo. Postal 70543, 04510 Mexico D. F. (Mexico); Marcazzo, J.; Santiago, M. [Instituto de Fisica Arroyo Seco / UNICEN, Gral. Pinto 399, 7000 Tandil, Buenos Aires (Argentina); Guarneros, C. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Altamira Km 14.5, 896000 Altamira, Tamaulipas (Mexico); Pacio, M. [Benemerita Universidad Autonoma de Puebla, Instituto de Ciencias, Centro de Investigacion en Dispositivos Semiconductores, Av. 14 Sur, 72570 Puebla, Pue. (Mexico); Palomino, R., E-mail: ecruz@nucleares.unam.mx [Benemerita Universidad Autonoma de Puebla, Facultad de Ciencias Fisico-Matematicas, Av. San Claudio y 18 Sur, 72570 Puebla Pue. (Mexico)

    2015-10-15

    Thermoluminescence (Tl) and radioluminescence (Rl) properties of lithium tetraborate (Li{sub 2}B{sub 4}O{sub 7}) doped with different concentration of copper (0.25, 0.5, 1 wt %) under gamma and beta irradiation has been investigated. The feasibility of using this borate in radiation dosimetry at low doses has been evaluated. Tissue equivalent Li{sub 2}B{sub 4}O{sub 7} was prepared by solid state reaction using mixing stoichiometric compositions of lithium carbonate (Li{sub 2}CO{sub 3}) and boric acid (H{sub 3}BO{sub 3}) and a solution of CuCl{sub 2} as dopant. The glow curve, of the most efficient copper doped borate (Li{sub 2}B{sub 4}O{sub 7}:Cu 0.5 wt %), shows a main stable peak centered at 225 degrees C and a second low temperature peak centered at 80 degrees C. The low temperature peak disappears completely after 24 hours of storage in darkness and at room temperature or after an annealing at 120 degrees C for 10 seconds. The main peak of the Li{sub 2}B{sub 4}O{sub 7}:Cu remains constant. The Tl response of Li{sub 2}B{sub 4}O{sub 7}:Cu shows good linearity in the analyzed dose range. The stability and repeatability of Rl signals of the borate have been studied and the Li{sub 2}B{sub 4}O{sub 7}:Cu (0.5 wt %) shown the higher Rl emission and a stable and repetitive response. Results show that Li{sub 2}B{sub 4}O{sub 7}:Cu has prospects to be used in gamma and beta radiation dosimetry. (Author)

  8. Studies of electrical resistance in Ni{sub 75}Cr{sub 7}Si{sub 7.5}Mn{sub 10.5} and Ni{sub 80.5}Cr{sub 4.2}Si{sub 6.5}Mn{sub 5}B{sub 3.8}glass-coated wires

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, C. [Dpto. de Fisica de Materiales, Fac. Quimicas, UPV/EHU, San Sebastian (Spain); Dpt. Material Science and Engineering, MIT, Cambridge (United States); Zhukova, V.; Blanco, J.M. [Dpto. de Fisica Aplicada, EUPDS, UPV/EHU, San Sebastian (Spain); Val, J.J. del; Zhukov, A. [Dpto. de Fisica de Materiales, Fac. Quimicas, UPV/EHU, San Sebastian (Spain)

    2009-04-15

    In this paper we studied thermal stability of Ni{sub 75}Cr{sub 7}Si{sub 7.5}Mn{sub 10.5} and Ni{sub 80.5}Cr{sub 4.2}Si{sub 6.5}Mn{sub 5}B{sub 3.8} glass coated microwires with metallic nucleus diameters ranging between 10 {mu}m and 20 {mu}m using electrical resistance measurements, X-ray diffraction and DSC methods. Electrical resistance was measured during Joule heating of the sample i.e. flowing the DC current. X-ray diffraction was used to determine the crystalline structure in as-prepared microwires. It was found that electrical resistance per length, {rho}, depends on the sample geometry. Besides this dependence is opposite for Ni{sub 75}Cr{sub 7}Si{sub 7.5}Mn{sub 10.5} and Ni{sub 80.5}Cr{sub 4.2}Si{sub 6.5}Mn{sub 5}B{sub 3.8} glass coated microwires. Such dependences have been related with effect of rapid solidification conditions on the grain sizes and consequently on grain growth process during annealing. Temperature coefficient of resistivity in the case of Ni{sub 75}Cr{sub 7}Si{sub 7.5}Mn{sub 10.5}microwires is much smaller (about 5 times smaller). Considerable dependence of the current density for beginning of phase transition on metallic nucleus diameter has been attributed to the thermal transfer conditions. Efficiently of Joule heating for the case of thinner microwires is smaller and the current density for achieving the phase transition-higher. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Thermodynamic properties of vitamin B{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Knyazev, A.V., E-mail: knyazevav@gmail.com; Letyanina, I.A.; Plesovskikh, A.S.; Smirnova, N.N.; Knyazeva, S.S.

    2014-01-10

    Graphical abstract: - Highlights: • Temperature dependence of heat capacity of vitamin B{sub 2} has been measured by precision adiabatic vacuum calorimetry. • The thermodynamic functions of the vitamin B{sub 2} have been determined for the range from T → 0 to 322 K. • The energy of combustion of the riboflavin has been measured at 298.15 K. • The enthalpy of combustion Δ{sub c}H° and the thermodynamic parameters Δ{sub f}H°, Δ{sub f}S°, Δ{sub f}G° have been calculated. - Abstract: In the present work temperature dependence of heat capacity of vitamin B{sub 2} (riboflavin) has been measured for the first time in the range from 6 to 322 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B{sub 2}, namely, the heat capacity, enthalpy H°(T) − H°(0), entropy S°(T) − S°(0) and Gibbs function G°(T) − H°(0) have been determined for the range from T → 0 to 322 K. The value of the fractal dimension D in the function of multifractal generalization of Debye's theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. In a calorimeter with a static bomb and an isothermal shield, the energy of combustion of the riboflavin has been measured at 298.15 K. The enthalpy of combustion Δ{sub c}H° and the thermodynamic parameters Δ{sub f}H°, Δ{sub f}S°, Δ{sub f}G° and of reaction of formation of the riboflavin from simple substances at T = 298.15 K and p = 0.1 MPa have been calculated.

  10. Coatings synthesised by the pulsed laser ablation of a B{sub 4}C/W{sub 2}B{sub 5} ceramic composite

    Energy Technology Data Exchange (ETDEWEB)

    Tadadjeu Sokeng, I., E-mail: ifriky@tlabs.ac.za [Department of Electrical, Electronics and Computer Engineering, French South African Institute of Technology/Cape Peninsula University of Technology, Bellville campus, PO Box 1906, Bellville, 7530 (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, 7129, PO Box 722, Somerset West, Western Cape Province (South Africa); UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Ngom, B.D. [Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, 7129, PO Box 722, Somerset West, Western Cape Province (South Africa); UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Laboratoire de Photonique et de Nanofrabrication, Groupes de physique du Solide et Sciences des Matriaux (GPSSM), Facult des sciences et Techniques Universit Cheikh Anta Diop de Dakar (UCAD), B.P. 25114 Dakar, Fann Dakar (Senegal); Msimanga, M. [iThemba LABS Gauten, Private Bag 11, WITS 2050 Johannesburg (South Africa); Nuru, Z.Y.; Kotsedi, L.; Maaza, M. [Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, 7129, PO Box 722, Somerset West, Western Cape Province (South Africa); UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Van Zyl, R.R. [Department of Electrical, Electronics and Computer Engineering, French South African Institute of Technology/Cape Peninsula University of Technology, Bellville campus, PO Box 1906, Bellville, 7530 (South Africa)

    2015-10-30

    A pellet of B{sub 4}C/W{sub 2}B{sub 5} ceramic composite was characterised and subjected to pulsed laser ablation for the deposition of coatings on corning glass substrates. We reports an attempt to produce coatings from B{sub 4}C/W{sub 2}B{sub 5} by pulsed laser deposition (PLD). The thermal, electric and mechanical properties of B{sub 4}C/W{sub 2}B{sub 5} suggest that coatings synthesised from this composite can be used for space applications. The samples were characterised using X-ray Diffraction, Atomic Force Microscopy and Heavy Ion Elastic Recoil Detection Analysis. The characterisation of the samples deposited on soda lime corning glass showed that the laser energy used in this PLD was enough to obtain non amorphous coatings formed by some alteration of the tungsten carbide crystal lattice at room temperature, and that there was no stoichiometry transfer as would be expected from PLD. The coating also showed space applicable features worth investigating. - Highlights: • B{sub 4}C/W{sub 2}B{sub 5} ceramic composite was ablated for deposition on corning glass subtrates. • Non-amorphous coating was obtained at room temperature. • There was no stoichiometry transfer as would be expected from Pulsed Laser Deposition.

  11. B>12P2: Improved Epitaxial Growth and Evaluation of Alpha Irradiation on its Electrical Transport Properties

    Energy Technology Data Exchange (ETDEWEB)

    Frye, Clint D. [Kansas State Univ., Manhattan, KS (United States)

    2016-10-17

    The wide bandgap (3.35 eV) semiconductor icosahedral boron phosphide (B>12P2) has been reported to self-heal from radiation damage from β particles (electrons) with energies up to 400 keV by demonstrating no lattice damage using transmission electron microscopy. This property could be exploited to create radioisotope batteries–semiconductor devices that directly convert the decay energy from a radioisotope to electricity. Such devices potentially have enormous power densities and decades-long lifetimes. To date, the radiation hardness of B>12P2 has not been characterized by electrical measurements nor have B>12P2 radioisotope batteries been realized. Therefore, this study was undertaken to evaluate the radiation hardness of B>12P2 after improving its epitaxial growth, developing ohmic electrical contacts, and reducing the residual impurities. Subsequently, the effects of radiation from a radioisotope on the electrical transport properties of B>12P2 were tested.

  12. Studies on influence of aluminium ions on the bioactivity of B{sub 2}O{sub 3}–SiO{sub 2}–P{sub 2}O{sub 5}–Na{sub 2}O–CaO glass system by means of spectroscopic studies

    Energy Technology Data Exchange (ETDEWEB)

    Mohini, G. Jagan; Krishnamacharyulu, N. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar, Guntur 522 510, Andhra Pradesh (India); Department of Physics, Andhra Loyola College, Vijayawada 520 008, Andhra Pradesh (India); Sahaya Baskaran, G., E-mail: sbalc@rediffmail.com [Department of Physics, Andhra Loyola College, Vijayawada 520 008, Andhra Pradesh (India); Rao, P. Venkateswara [Physics Department, University of West Indies, Mona Campus, Kingston (Jamaica); Veeraiah, N., E-mail: nvr8@rediffmail.com [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar, Guntur 522 510, Andhra Pradesh (India)

    2013-12-15

    Bioactive multi component glasses of the composition of 27.4 B{sub 2}O{sub 3}–6.4 SiO{sub 2}–2.5 P{sub 2}O{sub 5}–25.5 Na{sub 2}O–(38.2 − x) CaO: x Al{sub 2}O{sub 3} (x between 0 and 3.2) were synthesized, by melt quenching technique and their bioactivity was investigated as a function of Al{sub 2}O{sub 3} concentration. Initially, optical absorption and infrared spectra were recorded and analyzed in order to have some pre-understanding over structural aspects of the glasses. For understanding the bioactivity, the samples were immersed in simulated body fluid (SBF) solution for prolonged times (∼30 days) and the weight loss measurements were carried out. The spectroscopic studies were repeated on the post immersed samples. From the comparison of the analysis of the spectroscopic data of both pre-immersed and post-immersed samples together with the information on variation of pH value of residual solution as a function of immersion time, it is concluded that the participation of aluminium ions in tetrahedral positions is hindrance for the formation of HA layer and for the bioactivity of the samples.

  13. Simulation of interplanetary magnetic field B{sub y} penetration into the magnetotail

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jiuling [Center for Educational Technology, Peking University, Beijing 100871 (China); State Key Laboratory of Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China); Shen, Chao; Liu, Zhenxing [State Key Laboratory of Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-07-15

    Based on our global 3D magnetospheric MHD simulation model, we investigate the phenomena and physical mechanism of the B{sub y} component of the interplanetary magnetic field (IMF) penetrating into the magnetotail. We find that the dayside reconnected magnetic field lines move to the magnetotail, get added to the lobe fields, and are dragged in the IMF direction. However, the B{sub y} component in the plasma sheet mainly originates from the tilt and relative slippage of the south and north lobes caused by plasma convection, which results in the original B{sub z} component in the plasma sheet rotating into a B{sub y} component. Our research also shows that the penetration effect of plasma sheet B{sub y} from the IMF B{sub y} during periods of northward IMF is larger than that during periods of southward IMF.

  14. Specific heat of holmium and YNi{sub 2}B{sub 2}C. Criticalbehaviour and superconducting properties; Spezifische Waerme von Holmium und YNi{sub 2}B{sub 2}C. Kritisches Verhalten und supraleitende Eigenschaften

    Energy Technology Data Exchange (ETDEWEB)

    Bekkali, Abdelhakim

    2010-01-04

    Object of the thesis is the study of the specific heat of holmium and YNi{sub 2}B{sub 2}C in the temperature ranges from 50 to 200 KI respectively from 380 mK to 20 K in magnetic fields up to 9 T. In the present thesis the criticalbehaviour of YNi{sub 2}B{sub 2}C and properties of the superconducting state of tne non-magnetic rare-earth nickel borocarbide YNi{sub 2}B{sub 2}C are studied by means of a self-developed measurement apparatur of the specific heat using the quasi-adiabatic heating-pulse method as well as of holmium by means of the relaxation method. In this thesis reliable statements about the critical exponents on monocrystalline holmium could be made. The study on holmium proves that the critical behaviour of the specific heats cannot be described in the framework of the predictions of the chiral universality classes. By means of measurements of the specific heat in this thesis could be confirmed that YNi{sub 2}B{sub 2}C is a multiband superconductor. The positive curvature of the boundary line below T{sub c} in the phase diagram yields a first hint to the many-band character of YNI{sub 2}B{sub 2}C. In the zero-field the electronic specific heat in the superconducting state c{sub es}(T) can be not explained in the framework of the pure BCS theory. At low temperatures a residual contribution by normally conducting electrons could be detected, which hints to a not completely opened energy gap. A possible explanation would be that a band (or several bands) with low charge-carrier concentration not contribute to the superconductivity. This result agrees with de Haas-van Alphen measurements on isostructural superconducting LuNi{sub 2}B{sub 2}C monocrystals, which suggest the many-band character of the superconductivity as well as a vanishing energy gap in one band. The fluctuation behaviour of the specific heat of YNi{sub 2}B{sub 2}C in the neighbourhood of the superconducting-normally conducting transition agrees well with that of the 3D-XY model. [German

  15. Superconducting and normal state magnetic properties of RNi{sub 2}B{sub 2}C single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, D.C.; Borsa, F.; Cho, B.K. [Ames Lab., IA (United States)]|[Iowa State Univ., Ames, IA (United States). Dept. of Physics and Astronomy] [and others

    1995-10-01

    The authors` studies of the magnetic properties of RNi{sub 2}B{sub 2}C single crystals (R = Y, Gd-Tm, Lu) are reviewed. Of particular interest are the ordered magnetic structures when R is a magnetic rare earth atom, the interaction between magnetism and superconductivity, the influence of crystalline electric fields of the magnetic rare earth ions on these behaviors, and the magnetic character of the Ni sublattice.

  16. Structural and electrical conductivity studies on the solid electrolyte system {sub x}Li2O-(100-x) [0.5B{sub 2}O{sub 3}-0.5 P{sub 2}O{sub 5}] where 20

    Energy Technology Data Exchange (ETDEWEB)

    Padmasree, K. P.; Diaz-Guillen, M. R.; Diaz-Guillen, J. A.; Mendoza, E. M.; Fuentes, A. F. [Cinvestav, unidad Saltillo, Ramos Arizpe, Coahuila (Mexico)]. E-mail: padma512@yahoo.com

    2009-09-15

    Lithium ion conducting glasses have been extensively investigated due to their potential application as solid state amorphous electrolytes in lithium rechargeable batteries. The use of glassy electrolytes in all solid state devices may provide numerous advantages like increased safety, facility of fabrication and miniaturization and having a higher conductivity than those of the crystalline counterparts. In this work, we prepared and studied the Lithium ion conducting glassy solid electrolytes of the composition {sub x}Li{sub 2}O-(1-x)[0.5B{sub 2}O{sub 3} -0.5P{sub 2}O{sub 5}] where 20B{sub 2}O{sub 3} -0.5P{sub 2}O{sub 5}] donde 20

  17. Impact of family-non-universal Z' boson on pure annihilation B{sub s} → π{sup +}π{sup -} and B{sub d} → K{sup +}K{sup -} decays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ying; Wang, Wen-Long; Du, Dong-Shuo; Li, Zuo-Hong [Yantai University, Department of Physics, Yantai (China); Xu, Hong-Xia [Yantai University, Wenjing College, Yantai (China)

    2015-07-15

    We study the B{sub s} → π{sup +}π{sup -} and B{sub d} → K{sup +}K{sup -} decays in the standard model and the family-non-universal Z' model. Since none of the quarks in the final states is the same as the initial quark, these decay modes can occur only via power-suppressed annihilation diagrams. Despite the consistency of the standard model prediction with the available data, room remains for a light Z' boson. Taking into account the Z' contribution, we find that theoretical results for the branching fractions can better accommodate the data. With the relevant data, we also derive a constraint on the parameter space for the Z'. Moreover, for B{sub d} → K{sup +}K{sup -}, both the direct and the mixing-induced CP asymmetry are sensitive to the couplings between Z' and fermions in the parameter spaces constrained by the data. The measurements at future experimental facilities, including the LHCb, Belle-II, and the proposed high energy e{sup +}e{sup -} collider, will provide us useful hints for direct searching for the light Z' boson. (orig.)

  18. Impact of family-non-universal Z{sup ′} boson on pure annihilation B{sub s}→π{sup +}π{sup -} and B{sub d}→K{sup +}K{sup -} decays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ying, E-mail: liying@ytu.edu.cn; Wang, Wen-Long; Du, Dong-Shuo; Li, Zuo-Hong [Department of Physics, Yantai University, 264-005, Yantai (China); Xu, Hong-Xia [Wenjing College, Yantai University, 264-005, Yantai (China)

    2015-07-17

    We study the B{sub s}→π{sup +}π{sup -} and B{sub d}→K{sup +}K{sup -} decays in the standard model and the family-non-universal Z{sup ′} model. Since none of the quarks in the final states is the same as the initial quark, these decay modes can occur only via power-suppressed annihilation diagrams. Despite the consistency of the standard model prediction with the available data, room remains for a light Z{sup ′} boson. Taking into account the Z{sup ′} contribution, we find that theoretical results for the branching fractions can better accommodate the data. With the relevant data, we also derive a constraint on the parameter space for the Z{sup ′}. Moreover, for B{sub d}→K{sup +}K{sup -}, both the direct and the mixing-induced CP asymmetry are sensitive to the couplings between Z{sup ′} and fermions in the parameter spaces constrained by the data. The measurements at future experimental facilities, including the LHCb, Belle-II, and the proposed high energy e{sup +}e{sup -} collider, will provide us useful hints for direct searching for the light Z{sup ′} boson.

  19. Measurements of the magnetic vortex lattice in the noncentrosymmetric superconductor Ru{sub 7}B{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Tymoshenko, Yuliia; Cameron, Alistair; Inosov, Dmytro [Institut fuer Festkoerperphysik, TU Dresden (Germany); Balakrishnan, Geetha; Ciomaga Hatnean, Monica; Paul, Don McK. [Department of Physics, University of Warwick (United Kingdom)

    2016-07-01

    The noncentrosymmetric (NCS) superconductor Ru{sub 7}B{sub 3} has a hexagonal structure within the [001] plane. NCS superconductors are of significant interest to the condensed matter community, as their crystal structure breaks inversion symmetry, leading to novel superconducting states with unusual properties. Such states associated with NCS superconductors have been predicted to have a significant effect on the vortex lattice (VL) within these materials. We investigated a large single crystal of Ru{sub 7}B{sub 3} by small-angle neutron scattering (SANS). Our goal was to explore the possible influence of the NCS crystal structure on the VL order. During our measurements at the D33 SANS diffractometer at the Laue-Langevin Institute (ILL) in Grenoble, France we clearly observed the formation of VL in Ru{sub 7}B{sub 3}. The VL maintains its orientation and remains isotropic within the whole studied field and temperature range, implying a similar degree of isotropy in the SC parameters. An unusual VL rotation with decreasing field at base temperature was seen for field parallel to the (100) direction.

  20. Microstructures and mechanical properties in B{sub 4}C-CeO{sub 2} ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Sun Shuchen, E-mail: sunsc@smm.neu.edu.cn [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China); Sakamoto, Tatsuaki; Nakai, Kiyomichi [Department of Materials Science and Biotechnology, Ehime University, 3Bunkyo-cho, Matsuyama 790-8577 (Japan); Kurishita, Hiroaki [International Research Center for Nuclear Materials Science, Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Kobayashi, Sengo [Department of Materials Science and Biotechnology, Ehime University, 3Bunkyo-cho, Matsuyama 790-8577 (Japan); Xu Jingyu; Cao Hui; Gao Bo; Bianxue; Wu Wenyuan; Tu Ganfeng [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China); Matsuda, Seiji [Department of Anatomy and Embryology, Ehime University, Shizugawa, Toon 791-0295 (Japan)

    2011-10-01

    B{sub 4}C-CeO{sub 2} composite ceramics with various concentrations of CeO{sub 2} were fabricated by hot press. The effects of CeO{sub 2} on the microstructures and mechanical properties of the B{sub 4}C-CeO{sub 2} ceramics have been investigated. During hot press, CeB{sub 6} was formed by the reaction between CeO{sub 2} and B{sub 4}C. The B{sub 4}C-CeO{sub 2} ceramics had higher levels of density, fracture toughness, flexural strength and Vickers hardness than those in monolithic B{sub 4}C. The microstructures of the B{sub 4}C-CeO{sub 2} ceramics were observed and analyzed by transmission electron microscopy. In-situ synthesized CeB{sub 6} indicated whisker-like shape and grew along the interface with B{sub 4}C, and different boron carbides with different content of C existed at/around the interface of CeB{sub 6} with B{sub 4}C in the composite ceramics. It made mechanical properties greatly improved.

  1. A basic study on capture and solidification of rare earth nuclide (Nd) in LiCl-KCl eutectic salt using an inorganic composite with Li{sub 2}OAl{sub 2}O{sub 3}- SiO{sub 2}-B{sub 2}O{sub 3} systems

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Na Young; Eum, Hee Chul; Park, Hwan Seo; Ahn, Do Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-03-15

    The pyroprocessing of spent nuclear fuel generates LiCl-KCl eutectic waste salt containing radioactive rare earth nuclides. It is necessary to develop a simple process for the treatment of LiCl-KCl eutectic waste in a hot-cell facility. In this study, capture and solidification of a rare earth nuclide (Nd) in LiCl-KCl eutectic salt using an inorganic composite with a Li{sub 2}OAl{sub 2}O{sub 3}- SiO{sub 2}-B{sub 2}O{sub 3} system was conducted to simplify the existing separation and solidification process of rare earth nuclides in LiCl-KCl eutectic waste salt from the pyroprocessing of spent nuclear fuel. More than 98wt% of Nd in LiCl-KCl eutectic salt was captured when the mass ratio of the composite was 0.67 over NdCl3 in the eutectic salt. The content of Nd{sub 2}O{sub 3} in the Nd captured-composite reached about 50wt%, and this composite was directly fabricated into a homogeneous and chemical resistant glass waste in a monolithic form. These results will be utilized in designing a process to simplify the existing separation and solidification process.

  2. Non-isothermal nanocrystallization kinetics study on (Fe{sub 0.8}Ni{sub 0.15}M{sub 0.05}){sub 78}Si{sub 8}B{sub 14} (M = Nb, Ta, W) amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu [School of Materials Science and Engineering, Tongji University, Shanghai 201804 (China); Shanghai Key Lab. of D and A for Metal-Functional Materials, Shanghai 201804 (China); Yan, Biao, E-mail: yanbiao@vip.sina.com [School of Materials Science and Engineering, Tongji University, Shanghai 201804 (China); Shanghai Key Lab. of D and A for Metal-Functional Materials, Shanghai 201804 (China); Yang, Ying [School of Materials Science and Engineering, Tongji University, Shanghai 201804 (China); Shanghai Key Lab. of D and A for Metal-Functional Materials, Shanghai 201804 (China); Wang, Yuxin [School of Materials Science and Engineering, Tongji University, Shanghai 201804 (China); Shanghai Key Lab. of D and A for Metal-Functional Materials, Shanghai 201804 (China); Dept. of Chemical and Materials Engineering, The University of Auckland, PB 92019, Auckland 1142 (New Zealand)

    2013-10-15

    Highlights: •Nb, Ta and W addition affected nucleation and growth mechanism of FeNiSiB alloys. •The alloy with Ta had the best thermal stability compared to the other two alloys. •A process of Fe2B from metastable Fe3B phase existed in the alloy M = Ta. •Nb and W may inhibit formation of metastable Fe3B phase. -- Abstract: The nanocrystallization kinetics of the (Fe{sub 0.8}Ni{sub 0.15}M{sub 0.05}){sub 78}Si{sub 8}B{sub 14} (M = Nb, Ta, W) amorphous alloy was investigated by differential scanning calorimetry (DSC). Kissinger method, Ozawa method and the expended Friedman method were used to calculate and compare the kinetic parameters of the crystallization processes. The nanocrystallization mechanism for the non-isothermal primary crystallization of the amorphous alloys were discussed using Avrami exponent n. Transmission electron microscopy (TEM) studies verified the influence of nanocrystallization mechanism on the microstructure.

  3. Isospin violating decays of positive parity B{sub s} mesons in HMχPT

    Energy Technology Data Exchange (ETDEWEB)

    Fajfer, Svjetlana [University of Ljubljana, Department of Physics, Ljubljana (Slovenia); J. Stefan Institute, Jamova 39, P. O. Box 3000, Ljubljana (Slovenia); Prapotnik Brdnik, Anita [J. Stefan Institute, Jamova 39, P. O. Box 3000, Ljubljana (Slovenia); University of Maribor, Faculty of Civil Engineering, Transportation Engineering and Architecture, Maribor (Slovenia)

    2016-10-15

    Recent lattice QCD results suggest that the masses of the first two positive parity B{sub s} mesons lie below the BK threshold, similar to the case of D{sup *}{sub s0}(2317){sup +} and D{sub s1}(2460){sup +} mesons. The mass spectrum of B{sub s} mesons seems to follow the pattern of a D{sub s} mass spectrum. As in the case of charmed mesons, the structure of positive parity B{sub s} mesons is very intriguing. To shed more light on this issue, we investigate the strong isospin violating decays B{sub s0}{sup *0} → B{sub s}{sup 0}π{sup 0}, B{sub s1}{sup 0} → B{sub s}{sup *0}π{sup 0}, and B{sub s1}{sup 0} → B{sub s}{sup 0}ππ within heavy meson chiral perturbation theory. The two-body decay amplitude arises at tree level and we show that the loop corrections give significant contributions. On the other hand, in the case of three-body decay B{sub s1}{sup 0} → B{sub s}{sup 0}ππ the amplitude occurs only at loop level. We find that the decay widths for these decays are Γ(B{sub s1}{sup 0} → B{sub s}{sup 0}ππ) ∝ 10{sup -3} keV, and Γ(B{sub s0}{sup *0} → B{sub s}{sup 0}π{sup 0}) ≤ 55 keV, Γ(B{sub s1}{sup 0} → B{sub s}{sup *0}π{sup 0}) ≤ 50 keV. More precise knowledge of the coupling constant describing the interaction of positive and negative parity heavy mesons with light pseudo-scalar mesons would help to increase the accuracy of our calculation. (orig.)

  4. Microstructural analyses of B{sub 4}C-CeO{sub 2} and B{sub 4}C-La{sub 2}O{sub 3} ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Tatsuaki, E-mail: sakamoto.tatsuaki@eng.ehime-u.ac.jp [Department of Materials Science and Biotechnology, Ehime University, 3 Bunkyo-cho, Matsuyama 790-8577 (Japan); Sun, Shu-Chen [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China); Furuno, Tomoya; Kajioka, Michio [Graduate Student of Ehime Univerisity, 3 Bunkyo-cho, Matsuyama 790-8577 (Japan); Nakai, Kiyomichi [Department of Materials Science and Biotechnology, Ehime University, 3 Bunkyo-cho, Matsuyama 790-8577 (Japan); Kurishita, Hiroaki [International Research Center for Nuclear Materials Science, Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Kobayashi, Sengo [Department of Materials Science and Biotechnology, Ehime University, 3 Bunkyo-cho, Matsuyama 790-8577 (Japan); Wu, Wen-Yuan; Tu, Gan-Feng [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China); Matsuda, Seiji [Department of Anatomy and Embryology, Ehime University, Shizugawa, Toon 791-0295 (Japan)

    2011-10-01

    Effects of additions of CeO{sub 2} and La{sub 2}O{sub 3} on microstructure and mechanical properties of B{sub 4}C fabricated under and without hot press have been investigated. Vickers hardness and fracture strength are increased by hot press due to the reduction of porosity because the sintering rate is enhanced. Hardness is increased by the reduction of porosity because crack probably occurs when the hardness is measured due to pore as an initiation point of crack. Hardness increases with increasing additions of CeO{sub 2} and La{sub 2}O{sub 3} because porosity decreases due to the formation of CeB{sub 6} and LaB{sub 6} on the grain boundary of B{sub 4}C, respectively. The borides are formed through reaction between solid phases, which might induce coherent boundary between boride and B{sub 4}C. Such coherency also contributes to strengthening the grain boundary of B{sub 4}C. The addition of CeO{sub 2} enhances the sintering rate more than that of La{sub 2}O{sub 3}, resulting in higher hardness of B{sub 4}C-CeO{sub 2} than that of B{sub 4}C-La{sub 2}O{sub 3}.

  5. Study of CP violation in the channel B{sub d}{sup 0} {yields} J/{psi}(ee)K{sub S}{sup 0}, identification and reconstruction of electrons in the LHCb experiment; Etude de la violation de CP dans le canal B{sub d}{sup 0} {yields} J/{psi}(ee)K{sub S}{sup 0}, identification et reconstruction des electrons dans l'experience LHCb

    Energy Technology Data Exchange (ETDEWEB)

    Terrier, H

    2005-04-15

    LHCb experiment has been designed in order to do precise measurements of CP violation and rare decays with B mesons. In 2000, the collaboration decided to modify the spectrometer in order to minimize the amount of matter seen by particles and to optimize the trigger. This thesis was done in this context and is divided into 3 parts. The first part is relative to the electron identification and to the recovery of Bremsstrahlung photons emitted by electrons when they pass through matter. Electron identification is mainly based on information provided by calorimeter system but also uses RICH and muon system. A method based on reference histograms had been developed which combine information provided by these detectors. Electron identification efficiency, for electrons in ECAL acceptance is 95% and the pion mis-identification rates 0.8% with a 65% purity of electron sample. Bremsstrahlung recovery allows the selection of J/{phi} decaying in e{sup +}e{sup -} pair and of B{sub d}{sup 0} {yields} J/{phi}(ee)K{sub S}{sup 0} channel which are described in the second part. The selection of this channel was developed in order to get an acceptable selection efficiency with a good rejection of background. A set of kinematic and topological cuts were designed and total selection efficiency is 0.176%, corresponding to 28000 untagged events reconstructed by year, with a ratio B/S belonging to [0.017;0.069] (at 90% of confidence level) for inclusive bb-bar background. In the third part, B meson flavour tagging is presented. The addition of information provided by the vertex locator allows to reject electron coming from conversion and to improve slightly the performances. The LHCb sensibility to sin(2{beta}) from B{sup 0} {yields} J/{psi}K{sub S}{sup 0} decay is also determined. The statistical error, expected after one year of data collecting, corresponding to an integrated luminosity of 2 fb{sup -1} and bb-bar pair cross section of 0.5 mb, varies from 0.015 to 0.020 according to

  6. Improvement in bronchial squamous metaplasia in smokers treated with folate and vitamin B/sub 12/: report of a preliminary randomized, double-blind intervention trial

    Energy Technology Data Exchange (ETDEWEB)

    Heimburger, D.C.; Alexander, C.B.; Birch, R.; Butterworth, C.E. Jr.; Bailey, W.C.; Krumdieck, C.L.

    1988-03-11

    To test whether changes in folate and vitamin B/sub 12/ nutrition modify the severity of potentially premalignant lesions identified by cytology in sputum samples of smokers, the authors conducted a randomized, controlled prospective intervention trial in smokers with bronchial squamous metaplasia. Seventy-three men with a history of 20 or more pack-years of cigarette smoking who had metaplasia on one or more sputum samples were stratified according to smoking level and randomly assigned to four months' treatment with either placebo or 10 mg of folate plus 500 ..mu..g of hydroxocobalamin. Direct cytological comparison of the two groups after four months showed significantly greater reduction of atypia in the supplemented group. This provides preliminary evidence that atypical bronchial squamous metaplasia may be reduced by supplementation with folate and vitamin B/sub 12/. However, the significance of these findings is tempered by substantial spontaneous variation in sputum cytologies, the small study population, the short duration of the trial, and the supraphysiological doses of folate and B/sub 12/ used. The results should not be construed as pointing to a potential way of preventing lung cancer in individuals who continue to smoke or as supporting self-medication with large doses of folate or B/sub 12/ by smokers.

  7. Boron induced change of valence state of Eu in EuPd{sub 3}B{sub x} (0{<=}x{<=}0.55)

    Energy Technology Data Exchange (ETDEWEB)

    Gumeniuk, R.; Loison, C.; Leithe-Jasper, A.; Schnelle, W.; Burkhardt, U.; Schmidt, M.; Schmitt, M.; Schwarz, U.; Rosner, H. [Max-Planck-Inst. fuer Chemische Physik Fester Stoffe, Dresden (Germany)

    2007-07-01

    A detailed experimental and theoretical study of the solubility of B in cubic EuPd{sub 3} (AuCu{sub 3} structure type) and its influence on the physical properties is presented here. Theoretical calculations (LDA+U+CPA method) predict in EuPd{sub 3}B{sub x} a change of non-magnetic 4f{sup 6} Eu to magnetic 4f{sup 7} Eu for a boron content of x>0.2 together with an anomaly in the unit cell volume. At 950 C the incorporation of B in the structure of EuPd{sub 3}B{sub x} is possible up to x=0.55, as can be concluded from measurements of lattice parameters, WDXS and chemical analyses. The lattice parameter of EuPd{sub 3}B{sub x} varies linearly with B content (x) with a distinct change of slope at x=0.31. From Eu L{sub III} XAS studies as well as from measurements of magnetic susceptibility it can be deduced that Eu atoms in EuPd{sub 3} and in EuPd{sub 3}B{sub x} (0{<=}x{<=}0.31) exhibit a 4f{sup 6} state, while for EuPd{sub 3}B{sub x} (0.31{<=}x{<=}0.55) an intermediate valence state of (mixed 4f{sup 6} and 4f{sup 7}) can be assumed. Our findings are discussed with respect to previously published studies. (orig.)

  8. The rare semi-leptonic B{sub c} decays involving orbitally excited final mesons

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Wan-Li; Wang, Guo-Li [Department of Physics, Harbin Institute of Technology,Harbin, 150001 (China); Fu, Hui-Feng [Department of Physics, Tsinghua University,Beijing, 100084 (China); Wang, Zhi-Hui [Department of Physics, Beifang University of Nationalities,Yinchuan, 750021 (China); Li, Ying [Department of Physics, Yantai University,Yantai 264-005 (China)

    2015-09-24

    The rare processes B{sub c}→D{sub (s)J}{sup (∗)}μμ̄, where D{sub (s)J}{sup (∗)} stands for the final meson D{sub s0}{sup ∗}(2317), D{sub s1}(2460,2536), D{sub s2}{sup ∗}(2573), D{sub 0}{sup ∗}(2400), D{sub 1}(2420,2430) or D{sub 2}{sup ∗}(2460), are studied within the Standard Model. The hadronic matrix elements are evaluated in the Bethe-Salpeter approach and furthermore a discussion on the gauge-invariant condition of the annihilation hadronic currents is presented. Considering the penguin, box, annihilation, color-favored cascade and color-suppressed cascade contributions, the observables dBr/dQ{sup 2}, A{sub LPL}, A{sub FB} and P{sub L} are calculated.

  9. Three-chain B{sub 6n+14} cages as possible precursors for the syntheses of boron fullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Haigang, E-mail: luhg@sxu.edu.cn; Li, Si-Dian [Key Laboratory of Chemical Biology and Molecular Engineering of the Education Ministry, Institute of Molecular Science, Shanxi University, Taiyuan, Shanxi 030006 (China)

    2013-12-14

    Using the first principle methods, we proposed a series of three-chain boron cages B{sub 6n+14} (n = 1–12) which are mainly built by fusing three boron semi-double-rings. Their simple geometric structures (approximate D{sub 3} or C{sub 3} symmetry) facilitate their bottom-up syntheses from the hexagonal B{sub 7} and the double-chain boron clusters, such as B{sub 2}, B{sub 4}, B{sub 6}, B{sub 8}H{sub 2}, B{sub 10}H{sub 2}, B{sub 12}H{sub 2}, and the double ring B{sub 20}. The spherical shapes of these three-chain boron cages show that they could be taken as the possible precursors to further synthesize the boron fullerenes, such as B{sub 80}. Therefore, these three-chain boron cages provide a possible synthesis pathway of the boron fullerenes from the experimentally synthesized small planar boron clusters.

  10. Predicted electronic and structural properties of B{sub x}In{sub 1-x}As

    Energy Technology Data Exchange (ETDEWEB)

    Tayebi, N. [Laboratory of Applied Materials, University of Sidi Bel Abbes, 31 rue de Madagascar, Sidi Bel Abbes (Algeria); Benkabou, K., E-mail: kbenkabou@yahoo.fr [Laboratory of Applied Materials, University of Sidi Bel Abbes, 31 rue de Madagascar, Sidi Bel Abbes (Algeria); Aoumeur-Benkabou, F.Z. [Laboratory of Applied Materials, University of Sidi Bel Abbes, 31 rue de Madagascar, Sidi Bel Abbes (Algeria)

    2012-07-15

    Structural and electronic properties of the B{sub x}In{sub 1-x}As ternary alloy are studied using the tight binding method. The optical band gap bowing is calculated for the first time in the full range of Boron composition x. It is found to be strong. A small deviation from virtual crystal approximation is found for the bond length. New results on elastic constants are reported. The obtained results are in good agreement with the available data in the literature.

  11. Temperature affecting the magnetic properties of the Co{sub 79−x}Fe{sub 3}Cr{sub 3}Si{sub 15}B{sub x} amorphous alloy

    Energy Technology Data Exchange (ETDEWEB)

    Tsepelev, Vladimir, E-mail: v.s.tsepelev@urfu.ru [Boris Yeltzin Ural Federal University, Mira 19, Ekaterinburg 620002 (Russian Federation); Starodubtsev, Yuri [Boris Yeltzin Ural Federal University, Mira 19, Ekaterinburg 620002 (Russian Federation); Research and Production Enterprise «Gammamet», Kirov 28, Ekaterinburg 620028 (Russian Federation); Zelenin, Viktor; Belozerov, Vladimir [Research and Production Enterprise «Gammamet», Kirov 28, Ekaterinburg 620028 (Russian Federation); Konashkov, Viktor [Boris Yeltzin Ural Federal University, Mira 19, Ekaterinburg 620002 (Russian Federation)

    2015-09-15

    The paper studies the effect the temperature has on the magnetic properties of the Co{sub 79−x}Fe{sub 3}Cr{sub 3}Si{sub 15}B{sub x} amorphous alloy with different boron content. Magnetic saturation induction B{sub s} and Curie temperature T{sub C} decrease as the boron content increases. Within the range of relatively high temperatures, magnetic saturation induction B{sub s} = μ{sub 0}M{sub s} is related to the temperature by B{sub s}(T) ∼ (T{sub C} − T){sup 0.38}. In the Co{sub 79−x}Fe{sub 3}Cr{sub 3}Si{sub 15}B{sub x} amorphous alloys with the Curie temperature of lower than 180 °C the initial permeability of 200,000 and the coercive force of 0.1 A/m were obtained. The high initial permeability of the amorphous alloy is attributed to the absence of the crystalline, magnetoelastic and induced magnetic anisotropy in this alloy. Low Curie temperature near which the permeability appreciably increases (Hopkinson effect) is another approach to the ideal magnetic softness.

  12. A Measurement of the Time Dependence of B{sub d}-bar B{sub d} Mixing with Kaon Tagging

    Energy Technology Data Exchange (ETDEWEB)

    Wittlin, Jodi L.

    2001-12-10

    The time dependence of B{sub d} - {bar B}{sub d} mixing has been measured in b{bar b} events containing one or more kaons at the SLD experiment at the Stanford Linear Accelerator Center. A simultaneous measurement of the ''right sign production fraction'' of kaons from B{sub d} decays has also been made. The initial state B hadron flavor was determined using the large forward-backward asymmetry provided by the polarized electron beam of the SLC in combination with a jet charge technique and information from the opposite hemisphere. From a sample of 400,000 Z{sup 0} events collected by the SLD experiment at SLC from 1996 to 1998, the kaon right sign production fraction has been measured to be 0.797 {+-} 0.022 and the mass difference between the two B{sub d} eigenstates has been measured to be {Delta}m{sub d} = 0.503 {+-} 0.028 {+-} 0.020 ps{sup -1}.

  13. B{sub 36} borophene as an electronic sensor for formaldehyde: Quantum chemical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shahbazi Kootenaei, Amirhossein, E-mail: a.kootenaei@gmail.com [Department of Chemical Engineering, Mahshahr Branch, Islamic Azad University, Mahshahr (Iran, Islamic Republic of); Ansari, Goodarz [Department of Chemistry, Mahshahr Branch, Islamic Azad University, Mahshahr (Iran, Islamic Republic of)

    2016-08-06

    Pristine carbon nanotubes and graphene show great sensitivity toward several lethal gases but cannot identify some extremely toxic chemicals such as formaldehyde (HCOH). Recent successful synthesis of all-boron graphene-like sheets attracted strong interest in exploring their possible applications. Herein, we inspected the potential application of B{sub 36} borophene sheet as a sensor for HCOH detection, using density functional theory computations. Different theoretical levels including B97D and Minnesota 06 functionals with different basis sets were employed. It was predicted that the electrical conductivity of B{sub 36} borophene significantly increases at the presence of HCOH molecules, thereby generating an electrical signal. The electrical signal is increased by increasing the number of adsorbed HCOH molecules, indicating that this sensor is sensitive to the concentration (or pressure) of HCOH gas. These results suggest that the pristine borophene may be used in the HCOH chemical sensors. - Highlights: • B{sub 36} borophene sheet can be used as a chemical sensor for HCOH detection. • The B{sub 36} is sensitive to the concentration of HCOH. • When the B{sub 36} adsorbs HCOH molecules, it is converted to a p-type semiconductor.

  14. On the spin-2 Kaluza-Klein spectrum of AdS{sub 4}×S{sup 2}(B{sub 4})

    Energy Technology Data Exchange (ETDEWEB)

    Richard, Jean-Marc [Université Claude Bernard (Lyon 1)UMR 5822, CNRS/IN2P3, Institut de Physique Nucléaire de Lyon4 rue Enrico Fermi, F-69622 Villeurbanne Cedex (France); Terrisse, Robin [Université Claude Bernard (Lyon 1)UMR 5822, CNRS/IN2P3, Institut de Physique Nucléaire de Lyon4 rue Enrico Fermi, F-69622 Villeurbanne Cedex (France); Université de Lyon, ENS de Lyon,46 allée d’Italie, F-69364 Lyon CEDEX 07 (France); Tsimpis, Dimitrios [Université Claude Bernard (Lyon 1)UMR 5822, CNRS/IN2P3, Institut de Physique Nucléaire de Lyon4 rue Enrico Fermi, F-69622 Villeurbanne Cedex (France)

    2014-12-22

    We perform a numerical study of the four-dimensional spin-2 Kaluza-Klein spectrum of supersymmetric AdS{sub 4}×S{sup 2}(B{sub 4}) vacua and show that they do not exhibit scale separation. Our methods are generally applicable to similar problems where the compactification geometry is not known analytically, hence an analytic treatment of the spectrum of Kaluza-Klein masses is not available.

  15. Wear properties of Fe-Cr-C and B{sub 4}C powder coating on AISI 316 stainless steel analyzed by the Taguchi method

    Energy Technology Data Exchange (ETDEWEB)

    Gur, Ali Kaya; Ozay, Cetin; Orhan, Ayhan; Buytoz, Soner; Caligulu, Ugur; Yigitturk, Necmettin [Firat Univ., Elazig (Turkey). Faculty of Technical Education

    2014-06-01

    In this study, the plasma arc welded cladding of FeCrC and B{sub 4}C powder mixtures alloyed with 70 wt.-% Cr on the surface of AISI 316 stainless steel was investigated. Application of the Taguchi method revealed respective effects on the abrasive wear resistance of the cladding layer on the stainless steel. The abrasive wear behaviour of the AISI 316 stainless steel surfaces coated with Fe-Cr-C and with 10 wt.-%, 15 wt.-%, 20 wt.-%, and 25 wt.-% B{sub 4}C was investigated by using four loads and four distances for the 220 mesh SiC abrasive. Results were analyzed by variance analysis using ANOVA, and effects of parameters on the wear rate were determined as percentage rate. Furthermore, the error ratio was statistically evaluated. The experimental results were analyzed by the respective analysis of means and variance which is discussed in detail. (orig.)

  16. Simultaneous determination of fumonisins B{sub 1}, B{sub 2} and B{sub 3} contaminants in maize by ultra high-performance liquid chromatography tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ren Yiping [Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang (China); Zhang Yu [Department of Food Science and Nutrition, School of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310029, Zhejiang (China); Han Shiyun; Han Zheng [Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang (China); Wu Yongning, E-mail: wuyncdc@yahoo.com.cn [Key Lab of Chemical Safety and Health, National Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, 29 Nanwei Road, Beijing 100050 (China)

    2011-04-29

    The present work developed an analytical method for simultaneous determination of fumonisins B{sub 1}, B{sub 2} and B{sub 3} residues in maize by ultra high-performance liquid chromatography combined with electrospray ionization triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) under the multiple reaction monitoring (MRM) mode, and especially focused on the optimization of extraction, clean-up, UHPLC separation and MS/MS parameters. The method involves addition of fumonisins isotope internal standards, extraction with a mixture of acetonitrile and water and clean-up with solid-phase extraction (SPE) cartridges before UHPLC-MS/MS analysis. A single-laboratory method validation was conducted by testing three different spiking levels for repeatability and recovery according to International Union of Pure and Applied Chemistry (IUPAC) guidelines. The LOQ of FB{sub 1}, FB{sub 2} and FB{sub 3} were 1.50, 1.65 and 0.4 {mu}g kg{sup -1}, respectively, which were lower than the criteria of EU, USA and other countries regarding minimum residue limits of fumonisins in foods including baby foods and feedstuffs. Recoveries of three fumonisins ranged from 80.9% to 97.0% with RSD values of 2.4-11.1%.The advantages of this method include simple pretreatment, rapid determination and high sensitivity, and it fulfills the requirements for food analysis with respect to minimum residue limits of fumonisins in various countries.

  17. Photocatalytic characteristics of single phase Fe-doped anatase TiO{sub 2} nanoparticles sensitized with vitamin B{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Gharagozlou, Mehrnaz, E-mail: gharagozlou@icrc.ac.ir [Department of Nanomaterials and Nanotechnology, Institute for Color Science and Technology, Tehran (Iran, Islamic Republic of); Bayati, R. [Intel Corporation, IMO-SC, SC2, Santa Clara, CA 95054 (United States)

    2015-01-15

    Highlights: • Anatase TiO{sub 2}/B{sub 12} hybrid nanostructured catalyst was successfully synthesized by sol–gel technique. • The nanoparticle catalyst was doped with iron at several concentrations. • Nanoparticles were characterized in detail by XRD, Raman, TEM, EDS, and spectroscopy techniques. • The formation mechanism and role of point defects on photocatalytic properties were discussed. • A structure-property-processing correlation was established. - Abstract: We report a processing-structure-property correlation in B{sub 12}-anatase titania hybrid catalysts doped with several concentrations of iron. Our results clearly show that low-level iron doping alters structure, defect content, and photocatalytic characteristics of TiO{sub 2}. XRD and Raman studies revealed formation of a single-phase anatase TiO{sub 2} where no iron based segregation in particular iron oxide, was detected. FT-IR spectra clearly confirmed sensitization of TiO{sub 2} nanoparticles with vitamin B{sub 12}. TEM micrographs and diffraction patterns confirmed crystallization of anatase nanoparticles with a radius of 15–20 nm. Both XRD and Raman signals showed a peak shift and a peak broadening which are surmised to originate from creation of point defects, namely oxygen vacancy and titanium interstitial. The doped samples revealed a narrower band gap as compared to undoped samples. Photocatalytic activity of the samples was assessed through measuring the decomposition rate of rhodamine B. It was found that sensitization with vitamin B{sub 12} and Fe-doping significantly enhances the photocatalytic efficiency of the anatase nanoparticles. We also showed that there is an optimum Fe-doping level where the maximum photocatalytic activity is achieved. The boost of photocatalytic activity was qualitatively understood to originate from a more effective use of the light photons, formation of point defects, which enhance the charge separation, higher carrier mobility.

  18. “W-X-M” transformations in isomerization of B{sub 39}{sup −} borospherenes

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Ting-Ting; Chen, Qiang; Mu, Yue-Wen; Lu, Haigang, E-mail: luhg@sxu.edu.cn, E-mail: lisidian@sxu.edu.cn; Li, Si-Dian, E-mail: luhg@sxu.edu.cn, E-mail: lisidian@sxu.edu.cn [Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, Taiyuan 030006 (China)

    2016-06-15

    The Stone-Wales transformation plays an important role in the isomerization of fullerenes and graphenic systems. The continuous conversions between neighboring six- and seven-membered rings in the borospherene (all-boron fullerene) B{sub 40} had been discovered (Martínez-Guajardo et al. Sci. Rep. 5, 11287 (2015)). In the first axially chiral borospherenes C{sub 3} B{sub 39}{sup −} and C{sub 2} B{sub 39}{sup −}, we identify three active boron atoms which are located at the center of three alternative sites involving five boron atoms denoted as “W”, “X”, and “M”, respectively. The concerted movements of these active boron atoms and their close neighbors between neighboring six- and seven-membered rings define the “W-X-M” transformation of borospherenes. Extensive first-principles molecular dynamics simulations and quadratic synchronous transit transition-state searches indicate that, via three transition states (TS1, TS2, and TS3) and two intermediate species (M1 and M2), the three-step “W-X-M” transformations convert the C{sub 3} B{sub 39}{sup −} global minimum into its C{sub 2} isomer at room temperature (300 K) and vice versa. The maximum barriers are only 3.89 kcal/mol from C{sub 3} to C{sub 2} B{sub 39}{sup −} and 2.1 kcal/mol from C{sub 2} to C{sub 3} B{sub 39}{sup −}, rendering dynamic fluxionalities to these borospherenes. Therefore, the “W-X-M” transformation plays an important role in the borospherenes and borospherene-based nanostructures.

  19. Branching ratios from B{sub s} and {Lambda}{sub b}{sup 0}

    Energy Technology Data Exchange (ETDEWEB)

    Matthew S. Martin

    2004-05-28

    CDF Run II relative branching ratio measurements for 65 pb{sup -1} of data in the channels B{sub s} {yields} D{sub s}{sup {-+}}{pi}{sup {-+}}, {Lambda} {sub b}{sup 0} {yields} {Lambda}{sub c}{sup {+-}}{pi}{sup {-+}} and B {yields} h{sup +}h{sup -} are presented. Further, an observation of B{sub s} {yields} K{sup {+-}} K{sup {-+}} and a measurement of A{sub CP} are presented.

  20. Charmless B{sub (s)} → VV decays in factorization-assisted topological-amplitude approach

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chao; Zhang, Qi-An [CAS, Institute of High Energy Physics, P.O. Box 918, Beijing (China); University of Chinese Academy of Sciences, School of Physics, Beijing (China); Li, Ying [Yantai University, Department of Physics, Yantai (China); CAS, State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Beijing (China); Lue, Cai-Dian [CAS, Institute of High Energy Physics, P.O. Box 918, Beijing (China); University of Chinese Academy of Sciences, School of Physics, Beijing (China); CAS, State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Beijing (China)

    2017-05-15

    Within the factorization-assisted topological-amplitude approach, we studied the 33 charmless B{sub (s)} → VV decays, where V stands for a light vector meson. According to the flavor flows, the amplitude of each process can be decomposed into eight different topologies. In contrast to the conventional flavor diagrammatic approach, we further factorize each topological amplitude into decay constant, form factors and unknown universal parameters. By χ{sup 2} fitting 46 experimental observables, we extracted 10 theoretical parameters with χ{sup 2} per degree of freedom around 2. Using the fitted parameters, we calculated the branching fractions, polarization fractions, CP asymmetries and relative phases between polarization amplitudes of each decay mode. The decay channels dominated by tree diagram have large branching fractions and large longitudinal polarization fraction. The branching fractions and longitudinal polarization fractions of color-suppressed decays become smaller. Current experimental data of large transverse polarization fractions in the penguin dominant decay channels can be explained by only one transverse amplitude of penguin annihilation diagram. Our predictions of the not yet measured channels can be tested in the ongoing LHCb experiment and the Belle-II experiment in the future. (orig.)

  1. Study of new complexes of uranium and comba radical. II-Complexes formed in the presence of OH{sup -}, CO{sub 3}H{sup -}, CH{sub 3}-COO{sup -}, and B{sub 4}={sub 7}; Estudio de nuevos complejos entre uranio y el radical CADMBA. II. Complejos formados en presencia de OH{sup -}, CO{sub 3}H, CH{sub 3}-COO{sup -} y B{sub 4}O{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Vera Palomino, V.; Galiano Sedano, J. A.; Parellada Bellod, R.; Bellido Gonzalez, A.

    1975-07-01

    Several complexes extracted with CDMBAC organic solutions from uranium aqueous solutions, in presence of sodium and ammonium hydroxides, are studied. These complexes fit to the general formula: U0{sub 2}(OH){sub n}(CDMBA){sub n}-2 . The uranium extraction in presence of an excess of sodium bicarbonate is also studied. From aqueous solutions of uranyl acetate we have isolated the complex U0{sub 2}(CH{sub 3}-C00){sub n} (CDMBA){sub n}-2. In presence of boric acid and sodium tetraborate an U-CDMBA compound containing boron in its molecule has being obtained by precipitation and liquid-liquid extraction. (Author) 5 refs.

  2. Metallization and softening of B{sub 6}O at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuehui [Institute of Physics and Chemistry, HNUST, Qinhuangdao, Hebei 066600 (China); Wang, Yachun; Yao, Tiankai; Li, Hui; Wu, Lailei; Yang, Meng [Key Laboratory of Metastable Materials Science and Technology, College of Material Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Zhang, Jingwu, E-mail: ziw@ysu.edu.cn [Key Laboratory of Metastable Materials Science and Technology, College of Material Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Gou, Huiyang, E-mail: huiyang.gou@gmail.com [Key Laboratory of Metastable Materials Science and Technology, College of Material Science and Engineering, Yanshan University, Qinhuangdao 066004 (China)

    2014-07-05

    Highlights: • Structural searching identified a high-pressure phase for B{sub 6}O with monoclinic Cc structure. • Cc structure B{sub 6}O is mechanically and dynamically stable. • Cc phase characterizes in pentagonal pyramids and zig-zag O–B1–O chains. • Cc phase shows metallization and softened hardness as compared to zero-pressure structure. - Abstract: Structural stability, elastic and electronic properties of boron suboxide, B{sub 6}O, up to 300 GPa were investigated by first-principles calculations. Structural searching and enthalpy differences calculations identify a high-pressure phase for B{sub 6}O with monoclinic Cc structure (denoted as β-B{sub 6}O), which is energetically preferable to the known R-3 m-type phase above 245 GPa. β-B{sub 6}O phase forms a three-dimensional covalent network mainly composed of pentagonal pyramids and zig-zag O–B1–O chains extended along c-direction. β-B{sub 6}O phase is found to be stable examined by the calculated elastic constants and phonon dispersion and exhibits metallic behavior and greater elastic and hardness anisotropy, totally different from the semiconducting character and relative isotropy of ground state structure. Moreover, β-B{sub 6}O is predicted to soften significantly with a Vicker’s hardness of about 20.7 GPa.

  3. A Search for Time Dependent B{sub S}{sup 0}-{bar B}{sub S}{sup 0} Oscillations Using Exclusively Reconstructed D{sub S}{sup +} AT SLD

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Cheng-Ju S

    2002-01-10

    The authors set a preliminary 95% C.L. exclusion on the oscillation frequency of B{sub s}{sup 0} - {bar B}{sub s}{sup 0} mixing using a sample of 400,000 hadronic Z{sup 0} decays collected by the SLD experiment at the SLC during the 1996-98 run. In this analysis, B{sub s}{sup 0} mesons are partially reconstructed by combining a fully reconstructed D{sub s} with other B{sub s}{sup 0} decay products. The D{sub s} decays are reconstructed via the {phi}{pi} and K*K channels. The b-hadron flavor at production is determined by exploiting the large forward-backward asymmetry of polarized Z{sup 0} {yields} b{bar b} decays as well as information from the hemisphere opposite to the reconstructed B decay. The flavor of the B{sub s}{sup 0} at the decay vertex is determined by the charge of the D{sub s}. A total of 361 candidates passed the final event selection cuts. This analysis excludes the following values of the B{sub s}{sup 0}-{bar B}{sub s}{sup 0} mixing oscillation frequency: {Delta}m{sub s} < 1.4 psec{sup -1} and 2.5 < {Delta}m{sub s} < 5.3 psec{sup -1} at the 95% confidence level.

  4. The study on surface chemical modification of Fe{sub 71.5}Cu{sub 1}Nb{sub 3}Si{sub 13.5}B{sub 9}V{sub 2} amorphous alloy ribbons and its piezomagnetic effect

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jie; Zhu, Zhenghou, E-mail: z00708@sina.com

    2016-12-01

    In this paper, a type of smooth even endogeny conversion coat composed of Cu{sub 0.86}Fe{sub 2.14}O{sub 4} and (Cu{sub 0.18}Fe{sub 0.82})Cu{sub 0.82}Fe{sub 1.18}O{sub 4} phases was successfully obtained by a conversion reaction on the surfaces of Fe{sub 71.5}Cu{sub 1}Nb{sub 3}Si{sub 13.5}B{sub 9}V{sub 2} amorphous alloy ribbons. In this way, its ribbon thickness was decreased about 6–8 µm equivalently. The phase composition and microstructure of the conversion coat were investigated by XRD and SEM. In addition, the adhesion test of epoxy resin and amorphous alloy ribbon was verified by dipping experiments. It is found that the interface bonding strength between the conversion coat and ribbons is strong comparatively. On one hand, the proper interface between conversion coat and epoxy resin make it easy for ribbons to be encapsulated; on the other hand, the ribbons perform better significant piezomagnetic effect than the untreated ones due to a thinner thickness. This work may be a good basic for the applications of Fe{sub 71.5}Cu{sub 1}Nb{sub 3}Si{sub 13.5}B{sub 9}V{sub 2} amorphous alloy ribbons in piezomagnetic sensor and other devices based on the piezomagnetism effect. - Highlights: • A conversion coat was successfully obtained on the surfaces of amorphous alloy ribbons. • The encapsulated problem was solved by the conversion coats. • The ribbon after reaction had a better piezomagnetic sensitivity.

  5. Electronic structure, Fermi surface and optical properties of metallic compound Be{sub 8}(B{sub 48})B{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Reshak, A.H. [Institute of Complex Systems, FFPW, CENAKVA, University of South Bohemia in CB, Nove Hrady 37333 (Czech Republic); Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia); Azam, Sikander, E-mail: sikander.physicst@gmail.com [Institute of Complex Systems, FFPW, CENAKVA, University of South Bohemia in CB, Nove Hrady 37333 (Czech Republic); Alahmed, Z.A. [Department of Physics and Astronomy, King Saud University, Riyadh 11451 (Saudi Arabia); Chyský, Jan [Department of Instrumentation and Control Engineering, Faculty of Mechanical Engineering, CTU in Prague, Technicka 4, 166 07 Prague 6 (Czech Republic)

    2014-02-15

    The band structure, density of states, electronic charge density, Fermi surface and optical properties for B{sub 8}(Be{sub 48})B{sub 2} compound has been investigated in the support of density functional theory (DFT). The atomic positions of B{sub 8}(Be{sub 48})B{sub 2} compound were optimized by minimization of the forces acting on the atoms using the full potential linear augmented plane wave (FPLAPW) method. We have employed the local density approximation (LDA), generalized gradient approximation (GGA) and Engal-Vosko GGA (EVGGA) to indulgence the exchange correlation potential by solving Kohn–Sham equations. The result shows that the compound is metallic with sturdy hybridization near the Fermi energy level (E{sub F}). The density of states at Fermi energy, N(E{sub F}), is determined by the overlaping between B-p, B-s and Be-s states. This overlaping is strong enough indicating metallic origin with different values of N(E{sub F}). These values are 16.4, 16.27 and 14.89 states/eV, and the corresponding bare linear low-temperature electronic specific heat coefficient (γ) is found to be 2.84, 2.82 and 2.58 mJ/mol K{sup 2} for EVGGA, GGA and LDA respectively. There exists a strong hybridization between B-s and B-p states, also between B-s and Be-p states around the Fermi level. The Fermi surface is composed of three sheets. These sheets consist of set of holes and electrons. The bonding features of the compounds are analyzed using the electronic charge density in the (101 and −101) crystallographic planes and also the analyzing of charge density shows covalent bonding between B and B. The linear optical properties are also deliberated and discussed in particulars. - Highlights: • The compound is metallic. • The density of states at the Fermi energy is calculated. • The bare linear low-temperature electronic specific heat coefficient is obtained. • Fermi surface is composed of three sheets. • The bonding features are analyzed using the electronic

  6. Analyzing B{sub s} - anti B{sub s} mixing. Non-perturbative contributions to bag parameters from sum rules

    Energy Technology Data Exchange (ETDEWEB)

    Mannel, T. [Siegen Univ. (Germany). FB 7, Theoretische Physik; Pecjak, B.D. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Pivovarov, A.A. [Siegen Univ. (Germany). FB 7, Theoretische Physik]|[Russian Academy of Sciecnes, Moscow (Russian Federation). Inst. for Nuclear Research

    2007-03-15

    We use QCD sum rules to compute matrix elements of the {delta}B=2 operators appearing in the heavy-quark expansion of the width difference of the B{sub s} mass eigenstates. Our analysis includes the leading-order operators Q and Q{sub S}, as well as the subleading operators R{sub 2} and R{sub 3}, which appear at next-to-leading order in the 1/m{sub b} expansion. We conclude that the violation of the factorization approximation for these matrix elements due to non-perturbative vacuum condensates is as low as 1-2%. (orig.)

  7. Structure elucidation and toxicity analyses of the radiolytic products of aflatoxin B{sub 1} in methanol-water solution

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Feng [Institute of Agro-food Science and Technology of Chinese Academy of Agricultural Sciences, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Key Opening Laboratory of Agricultural Products Processing and Quality Control, Ministry of Agriculture, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Graduate School of Chinese Academy of Agricultural Sciences, 12th Zhongguancun South Road, Hai Dian District, Beijing 100081 (China); Xie, Fang [Institute of Agro-food Science and Technology of Chinese Academy of Agricultural Sciences, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Key Opening Laboratory of Agricultural Products Processing and Quality Control, Ministry of Agriculture, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Xue, Xiaofeng [Bee Research Institute of Chinese Academy of Agricultural Sciences, 1st Xiangshan North Ditch, Hai Dian District, Beijing 100093 (China); Wang, Zhidong; Fan, Bei [Institute of Agro-food Science and Technology of Chinese Academy of Agricultural Sciences, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Key Opening Laboratory of Agricultural Products Processing and Quality Control, Ministry of Agriculture, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Ha, Yiming, E-mail: wxfay2011@hotmail.com [Institute of Agro-food Science and Technology of Chinese Academy of Agricultural Sciences, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China); Key Opening Laboratory of Agricultural Products Processing and Quality Control, Ministry of Agriculture, 2nd Yuanmingyuan West Road, Hai Dian District, Beijing 100193 (China)

    2011-09-15

    Highlights: {yields} Radiolytic products of aflatoxin B{sub 1} were produced under gamma irradiation. {yields} Seven key radiolytic products were structure-elucidated. {yields} Free-radical species in radiolytic solution resulted in the formation of products. {yields} Based on the structure-activity relationship analysis, the toxicity of radiolytic products was significantly reduced compared with that of AFB{sub 1}. {yields} The addition reaction on furan ring double bond was the reason for the reduced toxicity. - Abstract: The identification of the radiolytic products of mycotoxins is a key issue in the feasibility study of gamma ray radiation detoxification. Methanol-water solution (60:40, v/v) spiked with aflatoxin B{sub 1} (AFB{sub 1}; 20 mg L{sup -1}) was irradiated with Co{sup 60} gamma ray to generate radiolytic products. Liquid chromatography-quadruple time-of-flight mass spectrometry was applied to identify the radiolytic products of AFB{sub 1}. Accurate mass and proposed molecular formulas with a high-matching property of more than 20 radiolytic products were obtained. Seven key radiolytic products were proposed based on the molecular formulas and tandem mass spectrometry spectra. The analyses of toxicity and formation pathways were proposed based on the structure of the radiolytic products. The addition reaction caused by the free-radical species in the methanol-water solution resulted in the formation of most radiolytic products. Based on the structure-activity relationship analysis, the toxicity of radiolytic products was significantly reduced compared with that of AFB{sub 1} because of the addition reaction that occurred on the double bond in the terminal furan ring. For this reason, gamma irradiation is deemed an effective tool for the detoxification of AFB{sub 1}.

  8. Dipstick based immunochemiluminescence biosensor for the analysis of vitamin B{sub 12} in energy drinks: A novel approach

    Energy Technology Data Exchange (ETDEWEB)

    Selvakumar, L.S. [Fermentation Technology and Bioengineering Department, Central Food Technological Research Institute (a constituent laboratory of the Council of Scientific and Industrial Research, CSIR), Mysore 570020, Karnataka (India); Thakur, M.S., E-mail: msthakur@cftri.res.in [Fermentation Technology and Bioengineering Department, Central Food Technological Research Institute (a constituent laboratory of the Council of Scientific and Industrial Research, CSIR), Mysore 570020, Karnataka (India)

    2012-04-13

    Graphical abstract: (a) Schematic representation of immunochemiluminescence based dipstick technique for detection of vitamin B{sub 12}. (b) Enzymatic dephosphorylation of dioxetane by alkaline phosphatase. Highlights: Black-Right-Pointing-Pointer Dipstick based immunochemiluminescence biosensor proposed for vitamin B{sub 12} analysis. Black-Right-Pointing-Pointer The limit of detection of vitamin B{sub 12} is 1 ng mL{sup -1} and applied in energy drinks. Black-Right-Pointing-Pointer Chemiluminescence generated was inversely proportional to vitamin B{sub 12} concentration. Black-Right-Pointing-Pointer Chemiluminescence analytical procedure was compared with ELISA. Black-Right-Pointing-Pointer Alkaline phosphatase was stable chemiluminescent enzyme than Horse Radish Peroxidase. - Abstract: In this article, we describe a dipstick based immunochemiluminescence (immuno-CL) biosensor for the detection of vitamin B{sub 12} in energy drinks. The method is a direct competitive type format involving the immobilization of vitamin B{sub 12} antibody on nitrocellulose membrane (NC) followed by treatment with vitamin B{sub 12} and vitamin B{sub 12}-alkaline phosphatase conjugate to facilitate the competitive binding. The dipstick was further treated with substrate disodium 2-chloro-5-(4-methoxyspiro {l_brace}1,2-dioxetane-3,2 Cent-Sign -(5 Cent-Sign -chloro)tricyclo[3.3.1.13,7]decan{r_brace}-4-yl)-1-phenyl phosphate (CDP-Star) to generate chemiluminescence (CL). The number of photons generated was inversely proportional to the vitamin B{sub 12} concentration. After systematic optimization, the limit of detection was 1 ng mL{sup -1}. The coefficient of variation was below 0.2% for both intra- and inter-assay precision. Vitamin B{sub 12} was extracted from energy drinks with recovery ranged from 90 to 99.4%. Two different energy drinks samples were analyzed, and a good correlation was observed when the data were compared with a reference enzyme linked immuno sorbent assay (ELISA

  9. B{sub K}-parameter from N{sub f}=2 twisted mass lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Constantinou, M. [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Dimopoulos, P. [Roma Univ. (Italy). Dipt. di Fisica; Frezzotti, R. [Roma ' ' Tor Vergata' ' Univ. (Italy). Dipt. di Fisica; INFN, Rome (IT). Dipt. di Fisica] (and others)

    2011-01-07

    We present an unquenched N{sub f} = 2 lattice computation of the B{sub K} parameter which controls K{sup 0}- anti K{sup 0} oscillations. A partially quenched setup is employed with two maximally twisted dynamical (sea) light Wilson quarks, and valence quarks of both the maximally twisted and the Osterwalder-Seiler variety. Suitable combinations of these two kinds of valence quarks lead to a lattice definition of the B{sub K} parameter which is both multiplicatively renormalizable and O(a) improved. Employing the non-perturbative RI-MOM scheme, in the continuum limit and at the physical value of the pion mass we get B{sup RGI}{sub K}=0.729{+-}0.030, a number well in line with the existing quenched and unquenched determinations. (orig.)

  10. Absorption and transport of radioactive /sup 57/Co-vitamin B/sub 12/ in experimental giardiasis in rats

    Energy Technology Data Exchange (ETDEWEB)

    Deka, N.C.; Sehgal, A.K.; Chnuttani, P.N. (Post-Graduate Inst. of Medical Education and Research, Chandigarh (India))

    1981-11-01

    Giardiasis was produced in weanling albino rats by feeding suspension of Giardia lamblia cysts isolated from human stool. Experiments were carried out to assess the absorption and transport through intestinal wall of /sup 57/Co-vitamin B/sub 12/ in these rats. The results showed a significant impairment of the absorption of the vitamin in the rats with experimental giardiasis. However, the transport of the vitamin B/sub 12/ was unimpaired.

  11. Thermodynamic properties and low-temperature X-ray diffraction of vitamin B{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Knyazev, A.V., E-mail: knyazevav@gmail.com; Smirnova, N.N.; Shipilova, A.S.; Shushunov, A.N.; Gusarova, E.V; Knyazeva, S.S.

    2015-03-20

    Highlights: • Temperature dependence of heat capacity of vitamin B{sub 3} has been measured by precision adiabatic vacuum calorimetry. • The thermodynamic functions of the vitamin B{sub 3} have been determined for the range from T → 0 to 346 K. • The thermodynamic analysis of reactions involving nicotinic acid was made. • The low-temperature X-ray diffraction was used for the determination of coefficients of thermal expansion. - Abstract: In the present work temperature dependence of heat capacity of vitamin B{sub 3} (nicotinic acid) has been measured for the first time in the range from 5 to 346 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B{sub 3}, namely, the heat capacity, enthalpy H°(T) – H°(0), entropy S°(T) – S°(0) and Gibbs function G°(T) – H°(0) have been determined for the range from T → 0 to 343 K. The value of the fractal dimension D in the function of multifractal generalization of Debye’s theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. The thermodynamic parameters Δ{sub f}S°, Δ{sub f}G° at T = 298.15 K and p = 0.1 MPa have been calculated. The thermodynamic analysis of reactions involving nicotinic acid was made. The low-temperature X-ray diffraction was used for the determination of coefficients of thermal expansion.

  12. Elucidating structural order and disorder phenomena in mullite-type Al{sub 4}B{sub 2}O{sub 9} by automated electron diffraction tomography

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Haishuang; Krysiak, Yaşar [Institute of Inorganic Chemistry and Analytical Chemistry, Jakob-Welder-Weg 11, Johannes Gutenberg-University Mainz, 55128 Mainz (Germany); Hoffmann, Kristin [Crystallography, Department of Geosciences, Klagenfurter Str. 2, GEO, University of Bremen, 28359 Bremen (Germany); Institute of Inorganic Chemistry and Crystallography, Leobener Str. NW2, University of Bremen, 28359 Bremen (Germany); Barton, Bastian [Institute of Inorganic Chemistry and Analytical Chemistry, Jakob-Welder-Weg 11, Johannes Gutenberg-University Mainz, 55128 Mainz (Germany); Molina-Luna, Leopoldo [Department of Materials and Geoscience, Technische Universität Darmstadt, Petersenstr. 23, 64287 Darmstadt (Germany); Neder, Reinhard B. [Department of Physics, Lehrstuhl für Kristallographie und Strukturphysik, Friedrich-Alexander University Erlangen-Nürnberg, Staudtstr.3, 91058 Erlangen (Germany); Kleebe, Hans-Joachim [Department of Materials and Geoscience, Technische Universität Darmstadt, Petersenstr. 23, 64287 Darmstadt (Germany); Gesing, Thorsten M. [Institute of Inorganic Chemistry and Crystallography, Leobener Str. NW2, University of Bremen, 28359 Bremen (Germany); MAPEX Center for Materials and Processes, Bibliothekstr.1, University of Bremen, 28359 Bremen (Germany); Schneider, Hartmut [Crystallography, Department of Geosciences, Klagenfurter Str. 2, GEO, University of Bremen, 28359 Bremen (Germany); Fischer, Reinhard X. [Crystallography, Department of Geosciences, Klagenfurter Str. 2, GEO, University of Bremen, 28359 Bremen (Germany); MAPEX Center for Materials and Processes, Bibliothekstr.1, University of Bremen, 28359 Bremen (Germany); and others

    2017-05-15

    The crystal structure and disorder phenomena of Al{sub 4}B{sub 2}O{sub 9}, an aluminum borate from the mullite-type family, were studied using automated diffraction tomography (ADT), a recently established method for collection and analysis of electron diffraction data. Al{sub 4}B{sub 2}O{sub 9}, prepared by sol-gel approach, crystallizes in the monoclinic space group C2/m. The ab initio structure determination based on three-dimensional electron diffraction data from single ordered crystals reveals that edge-connected AlO{sub 6} octahedra expanding along the b axis constitute the backbone. The ordered structure (A) was confirmed by TEM and HAADF-STEM images. Furthermore, disordered crystals with diffuse scattering along the b axis are observed. Analysis of the modulation pattern implies a mean superstructure (AAB) with a threefold b axis, where B corresponds to an A layer shifted by ½a and ½c. Diffraction patterns simulated for the AAB sequence including additional stacking disorder are in good agreement with experimental electron diffraction patterns. - Graphical abstract: Crystal structure and disorder phenomena of B-rich Al{sub 4}B{sub 2}O{sub 9} studied by automated electron diffraction tomography (ADT) and described by diffraction simulation using DISCUS. - Highlights: • Ab-initio structure solution by electron diffraction from single nanocrystals. • Detected modulation corresponding mainly to three-fold superstructure. • Diffuse diffraction streaks caused by stacking faults in disordered crystals. • Observed streaks explained by simulated electron diffraction patterns.

  13. Effect of superconductivity on spin dynamics in (Y/sub 1-x/Re/sub x/)Rh/sub 4/B/sub 4/

    Energy Technology Data Exchange (ETDEWEB)

    Kumagai, K.; Fradin, F.Y.

    1982-01-01

    An adiabatic field-cycle method has been used to study spin dynamics of RE ions in (Y/sub 1-x/RE/sub x/)Rh/sub 4/B/sub 4/. Longitudinal dipolar fluctuations of RE moments are found to be the main source of the nuclear spin-lattice relaxation time of /sup 11/B. The variation of T/sub 1/ in the superconducting state is attributed to the reduction of the electronic spin-relaxation time, tau/sub m/, which is mainly determined by the RKKY type interaction mediated by the conduction electrons. 3 figures.

  14. Spectroscopic and dielectric properties of titanium doped MgO-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3} glass system

    Energy Technology Data Exchange (ETDEWEB)

    Raju, G Naga; Ramesh, N Ch; Naresh, P; Krishna, T L; Srinivasulu, K; Sudhkar, K S V; Rao, P Venkateswara, E-mail: gnag_9@rediffmail.com [Department of Physics, Acharya Nagarjuna University-Nuzvid Campus, Nuzvid - 521 201 (India)

    2009-07-15

    In this paper we have reported the influence of titanium ions on different spectroscopic and dielectric properties of MgO-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3} glasses. The analysis of result of all these studies has indicated that as the concentration of TiO{sub 2} increased in the glass matrix, there is a gradual transformation of titanium ions from octahedral position to tetrahedral positions and cause to increase the rigidity of glass network.

  15. Upper bounds on ε{sup ′}/ε parameters B{sub 6}{sup (1/2)} and B{sub 8}{sup (3/2)} from large N QCD and other news

    Energy Technology Data Exchange (ETDEWEB)

    Buras, Andrzej J. [TUM Institute for Advanced Study,Lichtenbergstr. 2a, D-85748 Garching (Germany); Physik Department, TU München,James-Franck-Straße, D-85748 Garching (Germany); Gérard, Jean-Marc [Centre for Cosmology, Particle Physics and Phenomenology (CP3),Université catholique de Louvain,Chemin du Cyclotron 2, B-1348 Louvain-la-Neuve (Belgium)

    2015-12-01

    We demonstrate that in the large N approach developed by the authors in collaboration with Bardeen, the parameters B{sub 6}{sup (1/2)} and B{sub 8}{sup (3/2)} parametrizing the K→ππ matrix elements 〈Q{sub 6}〉{sub 0} and 〈Q{sub 8}〉{sub 2} of the dominant QCD and electroweak operators receive both negativeO(1/N) corrections such that B{sub 6}{sup (1/2)}≤B{sub 8}{sup (3/2)}<1 in agreement with the recent lattice results of the RBC-UKQCD collaboration. We also point out that the pattern of the size of the hadronic matrix elements of all QCD and electroweak penguin operators Q{sub i} contributing to the K→ππ amplitudes A{sub 0} and A{sub 2}, obtained by this lattice collaboration, provides further support to our large N approach. In particular, the lattice result for the matrix element 〈Q{sub 8}〉{sub 0} implies for the corresponding parameter B{sub 8}{sup (1/2)}=1.0±0.2 to be compared with large N value B{sub 8}{sup (1/2)}=1.1±0.1. We discuss briefly the implications of these findings for the ratio ε{sup ′}/ε. In fact, with the precise value for B{sub 8}{sup (3/2)} from RBC-UKQCD collaboration, our upper bound on B{sub 6}{sup (1/2)} implies ε{sup ′}/ε in the SM roughly by a factor of two below its experimental value (16.6±2.3)×10{sup −4}. We also briefly comment on the parameter B̂{sub K} and the ΔI=1/2 rule.

  16. A novel high color purity blue-emitting phosphor: CaBi{sub 2}B{sub 2}O{sub 7}:Tm{sup 3+}

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jiangong, E-mail: lijiangong01@gmail.com [Department of Electronic Science and Engineering, Huanghuai University, Zhumadian 463000 (China); Yan, Huifang [Department of Foreign Languages and Literature, Huanghuai University, Zhumadian 463000 (China); Yan, Fengmei [Department of Chemistry and Chemical Engineering, Huanghuai University, Zhumadian 463000 (China)

    2016-07-15

    Graphical abstract: - Highlights: • A series of Tm{sup 3+}-doped CaBi{sub 2}B{sub 2}O{sub 7} blue-emitting phosphors were prepared. • The optimum doping content of Tm{sup 3+} ions was found. • The critical distance and concentration quenching mechanism was discussed. • The color purity of as prepared sample was analyzed and compared. - Abstract: A series of Tm{sup 3+}-doped CaBi{sub 2−x}B{sub 2}O{sub 7}:xTm{sup 3+} (0.02 ≤ x ≤ 0.12) blue-emitting phosphors with high color purity were prepared by solid-state reaction method. The crystal structure and luminescence properties of the as-prepared phosphors were studied. This phosphor shows a satisfactory blue performance (peak at 453 nm) due to the {sup 1}D{sub 2} → {sup 3}F{sub 4} transition of Tm{sup 3+} excited by 357 nm light. Investigation of Tm{sup 3+} content dependent emission spectra indicates that x = 0.04 is the optimum doping content of Tm{sup 3+} ions in the CaBi{sub 2}B{sub 2}O{sub 7} host. The critical distance and the concentration quenching mechanism were also investigated. In particular, the color purity of as prepared sample was analyzed and the result shows that the color purity of CaBi{sub 2}B{sub 2}O{sub 7}:Tm{sup 3+} is higher than the commercial blue phosphor BaMgAl{sub 10}O{sub 17}:Eu{sup 2+} (BAM:Eu{sup 2+}) and the latest reported Tm{sup 3+} doped blue phosphors. The present work suggests that the CaBi{sub 2}B{sub 2}O{sub 7}:Tm{sup 3+} phosphor is a potential blue-emitting candidate for the application in the near-UV WLEDs.

  17. Atom probe analysis and magnetic properties of nanocrystalline Fe{sub 84.3}Si{sub 4}B{sub 8}P{sub 3}Cu{sub 0.7}

    Energy Technology Data Exchange (ETDEWEB)

    Jafari, S., E-mail: sahar_jafari@iust.ac.ir [Magnetic Materials Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, 305-0047 (Japan); Center of Excellence for Ceramics in Energy and Environment, School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran, 16846-13114 (Iran, Islamic Republic of); Beitollahi, A., E-mail: beitolla@iust.ac.ir [Center of Excellence for Ceramics in Energy and Environment, School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran, 16846-13114 (Iran, Islamic Republic of); Yekta, B. Eftekhari [Center of Excellence for Ceramics in Energy and Environment, School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran, 16846-13114 (Iran, Islamic Republic of); Ohkubo, T. [Magnetic Materials Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, 305-0047 (Japan); Budinsky, Viktoria; Marsilius, Mie; Herzer, Giselher [Vacuumschmelze GmbH & Co. KG, D-63450, Hanau (Germany); Hono, K. [Magnetic Materials Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, 305-0047 (Japan)

    2016-07-25

    We have investigated the microstructure and the magnetic properties of as-cast and flash annealed (4 s at 420 °C–560 °C) Fe{sub 84.3}Si{sub 4}B{sub 8}P{sub 3}Cu{sub 0.7} melt-spun ribbons. The scanning electron microscopy-electron backscattered diffraction (SEM-EBSD) analyses proved the existence of crystalline layer with the thickness of 1 μm in the as-cast state on both the wheel-contacted and the free surfaces of ribbons. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) patterns showed that the crystalline surfaces were textured. Moreover, the microstructure, composition and phase evolution of surface crystallization were studied using TEM and 3DAP which the spherulitic microstructure on the surface was demonstrated. Flash annealing above 420 °C led to a nanocrystalline microstructure of containing 10–15 nm α-Fe (Si) crystallites embedded in a residual amorphous matrix containing Fe, Si, B and P. Three-dimensional atom probe (3DAP) and high resolution transmission electron microscopy (HRTEM) analysis revealed that boron and phosphorous were rejected from α-Fe (Si) phase and enriched in the residual amorphous phase. The nucleation of the nanocrystals occurs heterogeneously from the 3–5 nm α-Fe crystals that were present in the as-cast state. The saturation magnetic induction (B{sub s}) increases from B{sub s} = 1.55 T in the amorphous state to B{sub s} = 1.76 T after the crystallization. The saturation magnetostriction constant, λ{sub s}, decreased from originally 35 ppm in the as-cast state to about 14 ppm with coercive fields in the range of H{sub c} = 20–30 A/m. - Highlights: • We studied microstructure and magnetic properties of Fe{sub 84.3}Si{sub 4}B{sub 8}P{sub 3}Cu{sub 0.7} alloys. • The crystalline layer with spherulitic microstructure in as-cast state was shown. • In as-cast sample, nano clusters of α-Fe were detected within amorphous matrix. • B and P partitioned in amorphous phase that led to the grain growth

  18. Effects of B{sub 2}O{sub 3} addition on sintering behavior and microwave dielectric properties of ixiolite-structure ZnTiNb{sub 2}O{sub 8} ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Haitao, E-mail: msse_wuht@ujn.edu.cn; Mei, Quanjing; Xing, Chunfang; Bi, Jinxin

    2016-09-15

    The effects of B{sub 2}O{sub 3} additives on the sintering behavior, microstructure and microwave dielectric properties of ixiolite-structure ZnTiNb{sub 2}O{sub 8} ceramics prepared by conventional solid-state route were investigated. The B{sub 2}O{sub 3} additives, acting as a sintering aid, can effectively decrease the sintering temperature of ZnTiNb{sub 2}O{sub 8} ceramics to 1050 °C, due to the formation of liquid phase. Little second phase from XRD results was observed throughout the entire experiments. The variations in the dielectric constant (ε{sub r}) and quality factor (Q·f) of the ixiolite-structure ZnTiNb{sub 2}O{sub 8} ceramics were studied systematically depending on the adopting of B{sub 2}O{sub 3} and the sintering temperatures. With the increase of the B{sub 2}O{sub 3} addition, ε{sub r} and Q·f decreased and the temperature coefficient of resonant frequency (τ{sub f}) slightly fluctuated around −20 ppm/°C. The optimal microwave dielectric properties with high ε{sub r} ∼35.04, Q·f ∼50,100 GHz, and a near-zero τ{sub f} ∼−20.21 ppm/°C were obtained at 1 wt%-B{sub 2}O{sub 3}-doped samples sintered at 1050 °C. The relatively low sintering temperature and high dielectric properties in microwave range would make ZnTiNb{sub 2}O{sub 8} ceramics promising for application in electronics. - Highlights: • B{sub 2}O{sub 3} was doped to reduce the sintering temperature of ZnTiNb{sub 2}O{sub 8} ceramics. • The τ{sub f} values of ZnTiNb{sub 2}O{sub 8} ceramics were in range of −10.21 to −32.2 ppm/°C. • The 1 wt% B{sub 2}O{sub 3}-doped ZnTiNb{sub 2}O{sub 8} ceramics were sintered at 1050 °C. • The optimal microwave dielectric properties were ε{sub r} ∼35.04 and Q·ƒ ∼50,100 GHz.

  19. Structural, dielectric, impedance and optical properties of CaBi{sub 2}B{sub 2}O{sub 7} glasses and glass-nanocrystal composites

    Energy Technology Data Exchange (ETDEWEB)

    Majhi, Koushik [Materials Research Centre, Indian Institute of Science, Bangalore 560 012 (India); Varma, K.B.R., E-mail: kbrvarma@mrc.iisc.ernet.in [Materials Research Centre, Indian Institute of Science, Bangalore 560 012 (India)

    2009-10-15

    Optically clear glasses were fabricated by quenching the melt of CaCO{sub 3}-Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3} (in equimolecular ratio). The amorphous and glassy characteristics of the as-quenched samples were confirmed via the X-ray powder diffraction (XRD) and differential scanning calorimetric (DSC) studies. These glasses were found to have high thermal stability parameter (S). The optical transmission studies carried out in the 200-2500 nm wavelength range confirmed both the as-quenched and heat-treated samples to be transparent between 400 nm and 2500 nm. The glass-plates that were heat-treated just above the glass transition temperature (723 K) for 6 h retained {approx}60% transparency despite having nano-crystallites ({approx}50-100 nm) of CaBi{sub 2}B{sub 2}O{sub 7} (CBBO) as confirmed by both the XRD and transmission electron microscopy (TEM) studies. The dielectric properties and impedance characteristics of the as-quenched and heat-treated (723 K/6 h) samples were studied as a function of frequency at different temperatures. Cole-Cole equation was employed to rationalize the impedance data.

  20. A roadmap to control penguin effects in B{sub d}{sup 0}→J/ψK{sub S}{sup 0} and B{sub s}{sup 0}→J/ψϕ

    Energy Technology Data Exchange (ETDEWEB)

    Bruyn, Kristof De [Nikhef,Science Park 105, NL-1098 XG Amsterdam (Netherlands); Fleischer, Robert [Nikhef,Science Park 105, NL-1098 XG Amsterdam (Netherlands); Department of Physics and Astronomy, Vrije Universiteit Amsterdam,De Boelelaan 1081, NL-1081 HV Amsterdam (Netherlands)

    2015-03-26

    Measurements of CP violation in B{sub d}{sup 0}→J/ψK{sub S}{sup 0} and B{sub s}{sup 0}→J/ψϕ decays play key roles in testing the quark-flavour sector of the Standard Model. The theoretical interpretation of the corresponding observables is limited by uncertainties from doubly Cabibbo-suppressed penguin topologies. With continuously increasing experimental precision, it is mandatory to get a handle on these contributions, which cannot be calculated reliably in QCD. In the case of the measurement of sin 2β from B{sub d}{sup 0}→J/ψK{sub S}{sup 0}, the U-spin-related decay B{sub s}{sup 0}→J/ψK{sub S}{sup 0} offers a tool to control the penguin effects. As the required measurements are not yet available, we use data for decays with similar dynamics and the SU(3) flavour symmetry to constrain the size of the expected penguin corrections. We predict the CP asymmetries of B{sub s}{sup 0}→J/ψK{sub S}{sup 0} and present a scenario to fully exploit the physics potential of this decay, emphasising also the determination of hadronic parameters and their comparison with theory. In the case of the benchmark mode B{sub s}{sup 0}→J/ψϕ used to determine the B{sub s}{sup 0}-B-bar{sub s}{sup 0} mixing phase ϕ{sub s} the penguin effects can be controlled through B{sub d}{sup 0}→J/ψρ{sup 0} and B{sub s}{sup 0}→J/ψ ( K)-bar {sup ∗0} decays. The LHCb collaboration has recently presented pioneering results on this topic. We analyse their implications and present a roadmap for controlling the penguin effects.

  1. Isovalent substitutes play in different ways: Effects of isovalent substitution on the thermoelectric properties of CoSi{sub 0.98}B{sub 0.02}

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hui, E-mail: huisun3@iflytek.com [Department of Basic Teaching, Anhui Institute of Information Technology, Wuhu, Anhui 241000 (China); Lu, Xu [College of Physics, Chongqing University, Chongqing 401331 (China); Morelli, Donald T. [Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan 48824 (United States)

    2016-07-21

    Boron-added CoSi, CoSi{sub 0.98}B{sub 0.02}, possesses a very high thermoelectric power factor of 60 μW cm{sup −1} K{sup −2} at room temperature, which is among the highest power factors that have ever been reported for near-room-temperature thermoelectric applications. Since the electrical properties of this material have been tuned properly, isovalent substitution for its host atoms is intentionally employed to reduce the lattice thermal conductivity while maintaining the electronic properties unchanged. In our previous work, the effect of Rh substitution for Co atoms on the thermoelectric properties of CoSi{sub 0.98}B{sub 0.02} has been studied. Here, we present a study of the substitution of Ge for Si atoms in this compound. Even though Ge and Rh are isovalent with their corresponding host atoms, they play different roles in determining the electrical and thermal transport properties. Through the evaluation of the lattice thermal conductivity by the Debye approximation and the comparison between the high-temperature Seebeck coefficients, we propose that Rh substitution leads to a further overlapping of the conduction and the valence bands, while Ge substitution only shifts the Fermi level upward into the conduction band. Our results show that the influence of isovalent substitution on the electronic structure cannot be ignored when the alloying method is used to improve thermoelectric properties.

  2. Tribological properties of B{sub 4}C-TiB{sub 2}-TiC-Ni cermet coating produced by HVOF

    Energy Technology Data Exchange (ETDEWEB)

    Rafiei, Mahdi [Islamic Azad Univ., Najafabad (Iran, Islamic Republic of). Dept. of Materials Engineering; Isfahan Univ. of Technology, Isfahan (Iran, Islamic Republic of). Depr. of Materials Engineering; Shamanian, Morteza; Salehi, Mehdi [Isfahan Univ. of Technology, Isfahan (Iran, Islamic Republic of). Depr. of Materials Engineering; Mostaan, Hossein [Arak Univ., Arak (Iran, Islamic Republic of). Dept. of Materials and Metallurgical Engineering

    2017-08-15

    In this study, B{sub 4}C-TiB{sub 2}-TiC-Ni coating was sprayed on the surface of 4130 steel by high velocity oxy-fuel torch. The tribological behavior of samples was studied by ball on disk wear testing. Structural evolution of the coating was analyzed by X-ray diffractometry. The microstructure of the coating, wear track and Al{sub 2}O{sub 3} ball was investigated by scanning electron microscopy, field emission scanning electron microscopy and optical microscopy. Elemental analysis of the wear track was done by energy dispersive X-ray spectroscopy. It was found that a cermet coating containing B{sub 4}C, TiB{sub 2}, TiC and Ni phases with good bonding to the 4130 steel substrate with no sign of any cracking or pores was formed. The wear mechanism of the composite coating was delamination. The friction coefficient of samples was decreased with increasing load because of higher frictional heat and creation of more oxide islands.

  3. Anomalous vortex dynamics in YNi{sub 2}B{sub 2}C

    Energy Technology Data Exchange (ETDEWEB)

    Okuma, S., E-mail: sokuma@o.cc.titech.ac.j [Research Center for Low Temperature Physics, Tokyo Institute of Technology, 2-12-1, Ohokayama, Meguro-ku, Tokyo 152-8551 (Japan); Ichimura, T. [Research Center for Low Temperature Physics, Tokyo Institute of Technology, 2-12-1, Ohokayama, Meguro-ku, Tokyo 152-8551 (Japan); Takeya, H.; Hirata, K. [National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2009-10-15

    We report on measurements of current-voltage (I-V) characteristics for YNi{sub 2}B{sub 2}C single crystals with weak pinning in various fields at 7.6 K. We find nonmonotonic, N-shaped I-V curves in a certain field region deep in the vortex solid phase. This behavior is anomalous, since there exists an intermediate I region where flow voltage V shows a decrease with increasing I (a driving force). While the exact nature remains unknown, this phenomenon suggests vortex motion (driving I) induced pinning.

  4. Unusual pinning induced by vortex motion in YNi{sub 2}B{sub 2}C

    Energy Technology Data Exchange (ETDEWEB)

    Okuma, S., E-mail: sokuma@o.cc.titech.ac.j [Research Center for Low Temperature Physics, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan); Ichimura, T. [Research Center for Low Temperature Physics, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan); Takeya, H.; Hirata, K. [National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2010-12-15

    We present measurements of current-voltage (I-V) characteristics and voltage noise S{sub V} generated by current-driven vortices for a YNi{sub 2}B{sub 2}C single crystal with weak-pinning. Nonmonotonic, N-shaped I-V curves are observed deep in the vortex-solid phase. In the intermediate I region where the unusual negative dV/dI is observed, S{sub V} exhibits a sharp peak. The result suggests vortex-motion-induced dynamic pinning.

  5. Magnetocaloric effect in amorphous and partially crystallized Fe{sub 40}Ni{sub 38}Mo{sub 4}B{sub 18} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Thanveer, T.; Thomas, S., E-mail: senoythomas@gmail.com [Materials Science and Technology Division, National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019 (India); Ramanujan, R. V. [School of Materials Science and Engineering, Nanyang Avenue, Nanyang Technological University, Singapore 639798 (Singapore)

    2016-05-15

    A study of magnetocaloric effect in amorphous and partially crystallized Fe{sub 40}Ni{sub 38}Mo{sub 4}B{sub 18} alloys is reported. Amorphous Fe{sub 40}Ni{sub 38}Mo{sub 4}B{sub 18}, near its magnetic ordering temperature (600 K) showed a magnetic entropy change ΔS{sub M} of 1.1 J/KgK and a relative cooling power of 36 J/Kg in a field change of 10 kOe. Amorphous samples were partially crystallized by annealing at 700 K at different time intervals. Partially crystallized samples showed two distinct magnetic ordering temperature, one corresponding to the precipitated FeNi nanocrystals and the other one corresponding to the boron rich amorphous matrix. Magnetic ordering temperature of the residual amorphous matrix got shifted to the lower temperatures on increasing the annealing duration. Partially crystallised samples showed a magnetic entropy change of about 0.27 J/kgK near the magnetic ordering temperature of the amorphous matrix (540 K) in a field change of 10 kOe. The decrease in ΔS{sub M} on partial crystallisation is attributed to the biphasic magnetic nature of the sample.

  6. Elastic rotation of Escherichia coli F{sub O}F{sub 1} having ε subunit fused with cytochrome b{sub 562} or flavodoxin reductase

    Energy Technology Data Exchange (ETDEWEB)

    Oka, Hideyuki [Department of Bioscience, Nagahama Institute of Bioscience and Technology, Nagahama, Shiga 526-0829 (Japan); Hosokawa, Hiroyuki; Nakanishi-Matsui, Mayumi [Department of Biochemistry, Faculty of Pharmaceutical Sciences, Iwate Medical University, Yahaba, Iwate 028-3694 (Japan); Dunn, Stanley D. [Department of Biochemistry, University of Western Ontario, London, Ontario N6A 5C1 (Canada); Futai, Masamitsu [Department of Biochemistry, Faculty of Pharmaceutical Sciences, Iwate Medical University, Yahaba, Iwate 028-3694 (Japan); Iwamoto-Kihara, Atsuko, E-mail: a_iwamoto@nagahama-i-bio.ac.jp [Department of Bioscience, Nagahama Institute of Bioscience and Technology, Nagahama, Shiga 526-0829 (Japan)

    2014-04-18

    Highlights: • Intra-molecular rotation of F{sub O}F{sub 1} ATP synthase was observed using a small bead probe. • Carboxyl-terminus of the ε subunit was fused to cytochrome b{sub 562} or flavodoxin reductase. • The F{sub O}F{sub 1} showed continual rotation with similar rate to the wild-type enzyme. • The intra-molecular rotation is flexible and elastic. - Abstract: Intra-molecular rotation of F{sub O}F{sub 1} ATP synthase enables cooperative synthesis and hydrolysis of ATP. In this study, using a small gold bead probe, we observed fast rotation close to the real rate that would be exhibited without probes. Using this experimental system, we tested the rotation of F{sub O}F{sub 1} with the ε subunit connected to a globular protein [cytochrome b{sub 562} (ε-Cyt) or flavodoxin reductase (ε-FlavR)], which is apparently larger than the space between the central and the peripheral stalks. The enzymes containing ε-Cyt and ε-FlavR showed continual rotations with average rates of 185 and 148 rps, respectively, similar to the wild type (172 rps). However, the enzymes with ε-Cyt or ε-FlavR showed a reduced proton transport. These results indicate that the intra-molecular rotation is elastic but proton transport requires more strict subunit/subunit interaction.

  7. Preparation and characterization of zinc-exchanged montmorillonite and its effectiveness as aflatoxin B{sub 1} adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Dakovic, Aleksandra, E-mail: a.dakovic@itnms.ac.rs [Institute for Technology of Nuclear and Other Mineral Raw Materials, Franche d' Epere 86, P.O. Box 390, 11000 Belgrade (Serbia); Kragovic, Milan [Institute for Technology of Nuclear and Other Mineral Raw Materials, Franche d' Epere 86, P.O. Box 390, 11000 Belgrade (Serbia); Rottinghaus, George E. [Veterinary Medical Diagnostic Laboratory, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211 (United States); Ledoux, David R.; Butkeraitis, Paula [Department of Animal Science, University of Missouri, Columbia, MO 65211-5300 (United States); Vojislavljevic, Dubravka Z. [Department of Chemistry, University of Belgrade, P.O. Box 158, 11000 Belgrade (Serbia); Zaric, Snezana D. [Department of Chemistry, University of Belgrade, P.O. Box 158, 11000 Belgrade (Serbia); Department of Chemistry, Texas A and M University at Qatar, P.O. Box 23874 Doha (Qatar); Stamenic, Ljubisav [The Vinca Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia)

    2012-11-15

    A zinc-exchanged montmorillonite (Zn-MONT) was prepared from a natural montmorillonite (MONT) and the adsorption of aflatoxin B{sub 1} (AFB{sub 1}) was investigated at pH 3 and 7. Characterization of Zn-MONT was done by determination of chemical composition, the point of the zero charge (pH{sub pzc}), thermal (DTA/TGA/DTG) and X-ray powder diffraction (XRPD) analysis. Adsorption of AFB{sub 1} (C{sub 0} = 4 ppm) by Zn-MONT, at different solid/liquid ratios (10, 1 and 0.5 g L{sup -1}), at pH 3 or 7, showed that its adsorption was high (over 96%) and independent of pH, similar to MONT. No desorption of AFB{sub 1} from MONT-AFB{sub 1} and Zn-MONT-AFB{sub 1} complexes occurred at pH 6.5, suggesting strong binding of AFB{sub 1} by both adsorbents. Furthermore, AFB{sub 1} adsorption by Zn-MONT followed a non-linear (Langmuir) type of isotherm at pH 3 with a calculated maximum capacity of 60.17 mg g{sup -1}. The stability of MONT-AFB{sub 1} and Zn-MONT-AFB{sub 1} complexes was evaluated by calculating the binding energies between AFB{sub 1} and metal cations using quantum chemical methods. The evaluated interaction energies of AFB{sub 1} with hydrated Zn{sup 2+}, Mg{sup 2+}, and Ca{sup 2+} cations showed that the strongest interaction was the interaction of the Zn{sup 2+} system, -70.2 kcal mol{sup -1}, whereas energies for Mg{sup 2} and Ca{sup 2+} systems were -68.8 and -62.9 kcal mol{sup -1}, respectively. The results indicate that Zn-MONT can be suitable for potential practical application as both, an antibacterial and an aflatoxin binding agent. -- Highlights: Black-Right-Pointing-Pointer Adsorption of aflatoxin B{sub 1} (AFB{sub 1}) by zinc modified montmorillonite (Zn-MONT) was studied at pH 3 and 7. Black-Right-Pointing-Pointer Presence of zinc in the interlamellar space of MONT increased adsorption of AFB{sub 1}. Black-Right-Pointing-Pointer The binding energies between AFB{sub 1} and metal cations were calculated using quantum chemical methods. Black

  8. Effect of crystallization on soft magnetic properties of nanocrystalline Fe{sub 80}B{sub 10}Si{sub 8}Nb{sub 1}Cu{sub 1} alloy

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini-Nasb, Farzad, E-mail: f.hosseininasab@modares.ac.ir [Department of Nanotechnology, Faculty of Engineering, Tarbiat Modares University, P.O. Box 14115-143, Tehran 1411713116 (Iran, Islamic Republic of); Beitollahi, Ali, E-mail: beitolla@iust.ac.ir [School of Metallurgy and Materials Engineering, Iran Universities of Science and Technology, Tehran 1684613114 (Iran, Islamic Republic of); Moravvej-Farshi, Mohammad Kazem, E-mail: farshi_k@modares.ac.ir [Faculty of Electrical and Computer Engineering, Tarbiat Modares University, P.O. Box 14115-194, Tehran 1411713116 (Iran, Islamic Republic of)

    2015-01-01

    The crystallization processes that occur in amorphous melt-spun ribbons of nominal composition Fe{sub 80}B{sub 10}Si{sub 8}Nb{sub 1}Cu{sub 1} during preparation and heat treatment affect the soft magnetic properties of this alloy. Fe{sub 80}B{sub 10}Si{sub 8}Nb{sub 1}Cu{sub 1} alloys are prepared by different quenching rates (wheel speeds of 10, 20 and 40 m/s) and their soft magnetic properties are studied. The XRD data reveal that as the wheel speed increases, the fraction of crystallinity and the Fe–Si grain size both decrease. These data also show that the sample prepared by the wheel speed of 10 m/s exhibits α-Fe particles on its free surface. The data for the samples prepared by the wheel speed of 20 and 40 m/s are in good agreement with the HRTEM images. VSM measurements show that these nanostructured samples exhibit coercivity in the range of 3–21 A/m and magnetic saturation in the range of 1.55–1.78 T. - Highlights: • Fe{sub 80}B{sub 10}Si{sub 8}Nb{sub 1}Cu{sub 1} alloys are prepared by different quenching rates and their soft magnetic properties are studied. • Soft magnetic properties of the Fe{sub 80}B{sub 10}Si{sub 8}Nb{sub 1}Cu{sub 1} alloys are shown to strongly depend on their microstructures, specifically on the grain size. • XRD patterns and HRTEM images taken for the samples are in good agreement. • VSM measurements indicate the coercivities and magnetic saturations are in the ranges of 3–21 A/m and 1.55–1.78 T, respectively.

  9. The leukotriene B{sub 4} receptor, BLT1, is required for the induction of experimental autoimmune encephalomyelitis

    Energy Technology Data Exchange (ETDEWEB)

    Kihara, Yasuyuki, E-mail: kihara-yasuyuki@umin.net [Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Yokomizo, Takehiko [Department of Medical Biochemistry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582 (Japan); Core Research for Embryonic Science and Technology (CREST), Japan Science and Technology Agency (Japan); Kunita, Akiko; Morishita, Yasuyuki; Fukayama, Masashi [Department of Pathology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033 (Japan); Ishii, Satoshi; Shimizu, Takao [Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2010-04-09

    Leukotriene B{sub 4} (LTB{sub 4}) is a potent chemoattractant and activator of neutrophils, macrophages and T cells. These cells are a key component of inflammation and all express BLT1, a high affinity G-protein-coupled receptor for LTB{sub 4}. However, little is known about the neuroimmune functions of BLT1. In this study, we describe a distinct role for BLT1 in the pathology of experimental autoimmune encephalomyelitis (EAE) and T{sub H}1/T{sub H}17 immune responses. BLT1 mRNA was highly upregulated in the spinal cord of EAE mice, especially during the induction phase. BLT1{sup -/-} mice had delayed onset and less severe symptoms of EAE than BLT1{sup +/+} mice. Additionally, inflammatory cells were recruited to the spinal cord of asymptomatic BLT1{sup +/+}, but not BLT1{sup -/-} mice before the onset of disease. Ex vivo studies showed that both the proliferation and the production of IFN-{gamma}, TNF-{alpha}, IL-17 and IL-6 were impaired in BLT1{sup -/-} cells, as compared with BLT1{sup +/+} cells. Thus, we suggest that BLT1 exacerbates EAE by regulating the migration of inflammatory cells and T{sub H}1/T{sub H}17 immune responses. Our findings provide a novel therapeutic option for the treatment of multiple sclerosis and other T{sub H}17-mediated diseases.

  10. Improved estimates of the B{sub (s)}→VV decays in perturbative QCD approach

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Zhi-Tian; Li, Ying [Yantai Univ. (China). Dept. of Physics; Ali, Ahmed [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Lue, Cai-Dian [Institute of High Energy Physics, Beijing, BJ (China); Theoretical Physics Center for Science Facilities, CAS, Beijing (China); Liu, Xin [Jiangsu Normal Univ., Xuzhou (China). School of Physics and Electronic Engineering

    2015-01-15

    We reexamine the branching ratios, CP-asymmetries, and other observables in a large number of B{sub q}→VV(q=u,d,s) decays in the perturbative QCD (PQCD) approach, where V denotes a light vector meson (ρ,K{sup *},ω,φ). The essential difference between this work and the earlier similar works is of parametric origin and in the estimates of the power corrections related to the ratio r{sup 2}{sub i}=m{sup 2}{sub V{sub i}}/m{sup 2}{sub B} (i=2,3) (m{sub V} and m{sub B} denote the masses of the vector and B meson, respectively). In particular, we use up-to-date distribution amplitudes for the final state mesons and keep the terms proportional to the ratio r{sup 2}{sub i} in our calculations. Our updated calculations are in agreement with the experimental data, except for a limited number of decays which we discuss. We emphasize that the penguin annihilation and the hard-scattering emission contributions are essential to understand the polarization anomaly, such as in the B→φK{sup *} and B{sub s}→φφ decay modes. We also compare our results with those obtained in the QCD factorization (QCDF) approach and comment on the similarities and differences, which can be used to discriminate between these approaches in future experiments.

  11. B{sub 4}C protective coating under irradiation by QSPA-T intensive plasma fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Buzhinskij, O. I.; Barsuk, V. A. [Troitsk Institute for Innovation and Fusion Research (TRINITI) (Russian Federation); Begrambekov, L. B., E-mail: lbb@plasma.mephi.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation); Klimov, N. S.; Otroshchenko, V. G.; Putric, A. B. [Troitsk Institute for Innovation and Fusion Research (TRINITI) (Russian Federation)

    2016-12-15

    The effect of the QSPA-T pulsed plasma irradiation on the crystalline boron carbide B{sub 4}C coating was examined. The duration of the rectangular plasma pulses was 0.5 ms with an interval of 5–10 min between pulses. The maximum power density in the central part of plasma stream was 1 GW/m{sup 2}. The coating thickness varied from 20 to 40 μm on different surface areas. Modification of the surface layers and transformation of the coating at elevated temperature under plasma pulse irradiation during four successive series of impulses are described. It is shown that the boron carbide coating withstood the full cycle of tests under irradiation with 100 plasma pulses with peak power density of 1GW/m{sup 2}. Constitutive surface deterioration was not detected and the boron carbide coating kept crystal structure B{sub 4}C throughout the irradiation zone at the surface depth no less 2 μm.

  12. Determination of the CP violating phase {gamma}by a sum over common decay modes to B{sub S} and anti B{sub S}

    Energy Technology Data Exchange (ETDEWEB)

    Aleksan, R. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Physique des Particules Elementaires; Le Yaouanc, A. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique Theorique et Hautes Energies; Oliver, L. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique Theorique et Hautes Energies; Pene, O. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique Theorique et Hautes Energies; Raynal, J.C. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique Theorique et Hautes Energies

    1995-06-01

    To help the difficult determination of the angle {gamma} of the unitarity triangle, Aleksan, Dunietz and Kayser have proposed the modes of the type K{sup -}D{sup +}{sub s}, common to B{sub s} and anti B{sub s}. We point out that it is possible to gain in statistics by a sum over all modes with ground state mesons in the final state, i.e. K{sup -}D{sup +}{sub s}, K{sup *{sup -}}D{sup +}{sub s}, K{sup -}D{sup *{sup +}}{sub s}, K{sup *{sup -}}D{sup *{sup +}}{sub s}. The delicate point is the relative phase of these different contributions to the dilution factor D of the time dependent asymmetry. Each contribution to D is proportional to a product F{sup cb}F{sup ub}f{sub D{sub s}}f{sub K} where F denotes form factors and f decay constants. Within a definite phase convention (i.e. for example the one defined by the heavy quark symmetry in the limit of heavy quarks), lattice calculations do not show any change in sign when extrapolating to light quarks the form factors and decay constants. Then, we can show that all modes contribute constructively to the dilution factor, except the P-wave K{sup *{sup -}}D{sup *{sup +}}{sub s}, which is small. Quark model arguments based on wave function overlaps also confirm this stability in sign. By summing over all these models we find a gain of a factor 6 in statistics relatively to K{sup -}D{sup +}{sub s}. The dilution factor for the sum D{sub tot} is remarkably stable for theoretical schemes that are not in very strong conflict with data on B{yields} {psi}K(K{sup *}) or extrapolated from semileptonic charm form factors, giving D{sub tot} {>=} 0.6, always close to D(K{sup -}D{sup +}{sub s}). (orig.)

  13. Preparation and characterization of B{sub 4}C coatings for advanced research light sources

    Energy Technology Data Exchange (ETDEWEB)

    Störmer, Michael, E-mail: michael.stoermer@hzg.de [Helmholtz-Zentrum Geesthacht, Max-Planck-Strasse 1, D-21502 Geesthacht (Germany); Siewert, Frank [Helmholtz-Zentrum Berlin, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Sinn, Harald [European XFEL GmbH, Albert-Einstein-Ring 19, 22761 Hamburg (Germany)

    2016-01-01

    The challenging specifications for long X-ray mirrors for upcoming free-electron lasers can be achieved, especially for maintaining below 2 nm peak-to-valley shape error along the optical aperture of approximately 1 m-long mirrors. X-ray optical elements are required for beam transport at the current and upcoming free-electron lasers and synchrotron sources. An X-ray mirror is a combination of a substrate and a coating. The demand for large mirrors with single layers consisting of light or heavy elements has increased during the last few decades; surface finishing technology is currently able to process mirror lengths up to 1 m with microroughness at the sub-nanometre level. Additionally, thin-film fabrication is able to deposit a suitable single-layer material, such as boron carbide (B{sub 4}C), some tens of nanometres thick. After deposition, the mirror should provide excellent X-ray optical properties with respect to coating thickness errors, microroughness values and slope errors; thereby enabling the mirror to transport the X-ray beam with high reflectivity, high beam flux and an undistorted wavefront to an experimental station. At the European XFEL, the technical specifications of the future mirrors are extraordinarily challenging. The acceptable shape error of the mirrors is below 2 nm along the whole length of 1 m. At the Helmholtz-Zentrum Geesthacht (HZG), amorphous layers of boron carbide with thicknesses in the range 30–60 nm were fabricated using the HZG sputtering facility, which is able to cover areas up to 1500 mm long by 120 mm wide in one step using rectangular B{sub 4}C sputtering targets. The available deposition area is suitable for the specified X-ray mirror dimensions of upcoming advanced research light sources such as the European XFEL. The coatings produced were investigated by means of X-ray reflectometry and interference microscopy. The experimental results for the B{sub 4}C layers are discussed according to thickness uniformity, density

  14. Potentialities of the LHCb experiment for the discovery of the physics beyond the standard model in the B{sub d}{sup 0} {yields} {phi}K{sub S}{sup 0} decay; Etude du potentiel de l'experience LHCb pour la decouverte de physique au-dela du modele standard dans la desintegration B{sub d}{sup 0} {yields} {phi}K{sub S}{sup 0}

    Energy Technology Data Exchange (ETDEWEB)

    Viaud, B

    2003-10-01

    The Standard Model predicts the same time-dependant CP asymmetry in both B{sub d}{sup 0} -> J/{psi}K{sub S}{sup 0} and B{sub d}{sup 0} {yields} {phi}K{sub S}{sup 0} decays. This asymmetry is proportional to sin(2*{beta}). Any difference between the CP asymmetries measured in these 2 channels would indicate the presence of new phenomena beyond the Standard Model. We study the sensitivity of the LHCb experiment to this effect. To that end, we estimate the statistical error on the measurement of sin(2*{beta}) in the B{sub d}{sup 0} {yields} {phi}K{sub S}{sup 0} channel by LHCb. We do that with the LHCb classic detector, and then with the re-optimized detector. The number of simulated background events is too small with respect to the annual statistics to obtain precise evaluations. We developed several methods to improve these evaluations. In the most optimistic case, we predict that sin(2*{beta}) would be measured in the LHCb classic configuration with a statistical error equal to 0.56. With the re-optimized detector, this error is further improved: 0.29. (author)

  15. Thermal treatment of the Fe{sub 78} Si{sub 9} B{sub 13} alloy and the analysis of it magnetic properties through Moessbauer spectroscopy and Positronium annihilation; Tratamiento termico de la aleacion Fe{sub 78} Si{sub 9} B{sub 13} y el analisis de sus propiedades magneticas mediante Espectroscopia de Moessbauer y Aniquilacion de positronio

    Energy Technology Data Exchange (ETDEWEB)

    Lopez M, A

    2005-07-01

    The present work is divided in five chapters. In the first one a general vision of the amorphous alloys is given from antecedents, structure, obtaining methods, properties and problems that at the moment, focusing us in a certain moment to the iron base alloys and the anomalous problem of hardness that it presents the alloy Fe{sub 78}Si{sub 9}B{sub 13} like previously mention us. The second chapter tries on the basic theory of the techniques of Moessbauer spectroscopy and Positron Annihilation spectroscopy, used for the characterization of our alloy as well as the complementary technique of X-ray diffraction (XRD) to observe that the amorphous phase was even studying. The third chapter describes the experimental conditions that were used to study the alloy Fe{sub 78}Si{sub 9}B{sub 13} in each one of their thermal treatments. In the fourth chapter the obtained results and their discussion are presented. In the fifth chapter the conclusions to which were arrived after analyzing the results are presented. (Author)

  16. Vitamin B{sub 1}2 in Enrichments of hydrothermal vents sediments supplements with cobalt and methanol

    Energy Technology Data Exchange (ETDEWEB)

    Gomez y Gomez, Y.; Garcia-Pena, I.; Guerrero-Barajas, C.

    2009-07-01

    Vitamin B{sub 1}2 (VB12) is an important cofactor present in methanogens and acetogenic bacterium. Biosynthesis of cyanocobalamin under different anaerobic and aerobic conditions has been reported for sewage, granular sludge and pure cultures. Corrinoids containing cobalt have also been identified as components in at least one dehalogenases belonging to Dehalooccoides bacteria. (Author)

  17. New NZP-phosphates B{sub 0.5}FeTa(PO{sub 4}){sub 3} (where B - Ca, Sr, Ba)

    Energy Technology Data Exchange (ETDEWEB)

    Bortsova, Ye.V. [Chemical Department, Nizhni Novgorod State University, 603950 Nizhni Novgorod (Russian Federation); Koryttseva, A.K. [Chemical Department, Nizhni Novgorod State University, 603950 Nizhni Novgorod (Russian Federation)], E-mail: koak@mail.ru; Orlova, A.I. [Chemical Department, Nizhni Novgorod State University, 603950 Nizhni Novgorod (Russian Federation); Kurazhkovskaya, V.S. [Geological Department, Moscow State University, 119899 Moscow (Russian Federation); Kazantsev, G.N.; Samoilov, S.G. [Institute of Physics and Power Engineering, 249033 Obninsk, Kaluga Region (Russian Federation); Karuchkina, Ye.A. [Chemical Department, Nizhni Novgorod State University, 603950 Nizhni Novgorod (Russian Federation)

    2009-05-05

    New phosphates with NaZr{sub 2}(PO{sub 4}){sub 3} structure of the B{sub 0.5}FeTa(PO{sub 4}){sub 3}-type (where B-Ca, Sr, Ba) are synthesized and characterized by X-ray diffraction analysis and IR-spectroscopy. The heating behavior of the phosphates is studied using high-temperature X-ray crystallography in the range 15-625 deg. C. The unit-cell parameters, the coefficients of thermal expansion {alpha}{sub a}, {alpha}{sub c} and their thermal expansion anisotropy |{alpha}{sub c} - {alpha}{sub a}| of the phosphates under study are determined and the dependences of these characteristics on the nature of cations are established and analyzed.

  18. Structural relaxations in the bulk amorphous alloy Fe{sub 61}Co{sub 10}Ti{sub 3}Y{sub 6}B{sub 20}

    Energy Technology Data Exchange (ETDEWEB)

    Błoch, K., E-mail: 23kasia1@wp.pl; Nabiałek, M.; Gondro, J.

    2017-05-01

    The paper presents studies of annealing effect on the disaccommodation phenomenon in bulk amorphous alloy Fe{sub 61}Co{sub 10}Ti{sub 3}Y{sub 6}B{sub 20}. The investigated sample was prepared by suction-casting method in the form of rod. The annealing process has been performed at temperature well below the crystallisation temperature. The amorphous structure has been confirmed using X-ray diffractometer. The susceptibility and its disaccommodation were determined using completely automated set up. The disaccommodation curve was decomposed into three elementary processes, each of them was described by Gaussian distribution of relaxation times. The obtained results indicate that the disaccommodation phenomenon in studied alloy is related with directional ordering of atom pairs near the free volumes; this is in agreement with H. Kronmüller's theorem.

  19. Sulforaphane, a cancer chemopreventive agent, induces pathways associated with membrane biosynthesis in response to tissue damage by aflatoxin B{sub 1}

    Energy Technology Data Exchange (ETDEWEB)

    Techapiesancharoenkij, Nirachara [Laboratory of Environmental Toxicology, Chulabhorn Research Institute, Bangkok 10210 (Thailand); Fiala, Jeannette L.A. [Department of Biological Engineering and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Navasumrit, Panida [Laboratory of Environmental Toxicology, Chulabhorn Research Institute, Bangkok 10210 (Thailand); Croy, Robert G.; Wogan, Gerald N. [Department of Biological Engineering and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Groopman, John D. [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Ruchirawat, Mathuros [Laboratory of Environmental Toxicology, Chulabhorn Research Institute, Bangkok 10210 (Thailand); Essigmann, John M., E-mail: jessig@mit.edu [Department of Biological Engineering and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2015-01-01

    Aflatoxin B{sub 1} (AFB{sub 1}) is one of the major risk factors for liver cancer globally. A recent study showed that sulforaphane (SF), a potent inducer of phase II enzymes that occurs naturally in widely consumed vegetables, effectively induces hepatic glutathione S-transferases (GSTs) and reduces levels of hepatic AFB{sub 1}-DNA adducts in AFB{sub 1}-exposed Sprague Dawley rats. The present study characterized the effects of SF pre-treatment on global gene expression in the livers of similarly treated male rats. Combined treatment with AFB{sub 1} and SF caused reprogramming of a network of genes involved in signal transduction and transcription. Changes in gene regulation were observable 4 h after AFB{sub 1} administration in SF-pretreated animals and may reflect regeneration of cells in the wake of AFB{sub 1}-induced hepatotoxicity. At 24 h after AFB{sub 1} administration, significant induction of genes that play roles in cellular lipid metabolism and acetyl-CoA biosynthesis was detected in SF-pretreated AFB{sub 1}-dosed rats. Induction of this group of genes may indicate a metabolic shift toward glycolysis and fatty acid synthesis to generate and maintain pools of intermediate molecules required for tissue repair, cell growth and compensatory hepatic cell proliferation. Collectively, gene expression data from this study provide insights into molecular mechanisms underlying the protective effects of SF against AFB{sub 1} hepatotoxicity and hepatocarcinogenicity, in addition to the chemopreventive activity of this compound as a GST inducer. - Highlights: • This study revealed sulforaphane (SF)-deregulated gene sets in aflatoxin B{sub 1} (AFB{sub 1})-treated rat livers. • SF redirects biochemical networks toward lipid biosynthesis in AFB{sub 1}-dosed rats. • SF enhanced gene sets that would be expected to favor cell repair and regeneration.

  20. Interwoven magnetic and flux line structures in single crystal (Tm,Er)Ni{sub 2}B{sub 2}C (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Gammel, P. L. [Bell Laboratories, Lucent Technologies, 700 Mountain Avenue, Murray Hill, New Jersey 07974 (United States); Lopez, D. [Bell Laboratories, Lucent Technologies, 700 Mountain Avenue, Murray Hill, New Jersey 07974 (United States); Bishop, D. J. [Bell Laboratories, Lucent Technologies, 700 Mountain Avenue, Murray Hill, New Jersey 07974 (United States); Eskildsen, M. R. [Risoe National Laboratories, DK-4000, Roskilde, (Denmark); Andersen, N. H. [Risoe National Laboratories, DK-4000, Roskilde, (Denmark); Mortensen, K. [Risoe National Laboratories, DK-4000, Roskilde, (Denmark); Fisher, I. R. [Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); Cheon, K. O. [Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); Canfield, P. C. [Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)

    2000-05-01

    We review studies of the interactions between magnetic order and the flux line lattice (FLL) in the (RE)Ni{sub 2}B{sub 2}C intermetallic borocarbides for (RE)=Tm and Er using small angle neutron scattering (SANS) and magneto-transport. For (RE)=Tm the magnetic order and the FLL assume a common symmetry, sharing a phase transition at {approx}2 kOe, despite an order of magnitude difference in periodicity. For (RE)=Er, the penetration depth {lambda} and the coherence length {xi}, both of which are derived from the FLL form factor, are modified near T{sub N}=6 K by a theoretically predicted weakly divergent pairbreaking. Finally, below 2.3 K, (RE)=Er shows a coexistence of weak ferromagnetism and superconductivity. This state reveals a highly disordered FLL and a striking increase in the critical current, both arising from the strong ferromagnetic pairbreaking. (c) 2000 American Institute of Physics.

  1. Nanocrystallization and magnetic anisotropy in Co{sub 66}Si{sub 16}B{sub 12}Fe{sub 4}Mo{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, J.A. [Dep. de Fisica, Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Rivas, M. [Dep. de Fisica, Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain)]. E-mail: rivas@uniovi.es; Tejedor, M. [Dep. de Fisica, Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Svalov, A. [Dep. de Fisica, Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Pierna, A.R. [Dep. de Ingenieria Quimica y Medio Ambiente, Universidad del Pais Vasco, PO Box 1379, 20080 San Sebastian (Spain); Marzo, F.F. [Dep. de Ingenieria Quimica y Medio Ambiente, Universidad del Pais Vasco, PO Box 1379, 20080 San Sebastian (Spain)

    2005-04-15

    A study of the magnetic anisotropy originated by the nanocrystallization of the amorphous Co{sub 66}Si{sub 16}B{sub 12}Fe{sub 4}Mo{sub 2} is presented. Mechanically polished samples of this alloy were submitted to various thermal treatments to obtain different degrees of crystallization. The results show that an homogeneous distribution of nanocrystallites of about 10nm originates a magnetic anisotropy of 18Jm{sup -3} while the larger crystals that appear, due to the coalescence of the small crystallites, with annealings over 500 deg. C produce an increase of the magnetic anisotropy up to values of about 100Jm{sup -3}, that are similar to the ones of the as-quenched material. From the value of the effective magnetic anisotropy constant we deduce that in the samples annealed below the onset temperature, the majority of the crystallites are of Co{sub 2}B and Co{sub 3}B.

  2. Magnetic anisotropy of the spin-antiferromagnet GdNi{sub 2}B{sub 2}C probed by high-frequency ESR

    Energy Technology Data Exchange (ETDEWEB)

    Kataev, V; Schaufuss, U; Muranyi, F; Alfonsov, A; Buechner, B [IFW Dresden, PO Box 270116, D-01171 Dresden (Germany); Doerr, M [Institut fuer Festkoerperphysik, Technische Universitaet Dresden, D-01062 Dresden (Germany); Rotter, M, E-mail: v.kataev@ifw-dresden.d [Oxford University, Physics Department, Clarendon Laboratory, Parks Road, Oxford OX1 3PU (United Kingdom)

    2009-03-01

    A Gd{sup 3+} electron spin resonance study in a frequency range 10 - 350 GHz on a single crystal of the spin-only antiferromagnet GdNi{sub 2}B{sub 2}C is reported. The Korringa relaxation broadening of the Gd-ESR signal is surprisingly anisotropic implying anisotropic interactions between the localized Gd{sup 3+} spins and the conduction electrons. In the antiferromagnetic state at T

  3. Vitamin B/sub 12/ production from whey and simulation of optimal cultural conditions. [Propionibacterium shermanii 566

    Energy Technology Data Exchange (ETDEWEB)

    Marwaha, S.S.; Kennedy, J.F.; Sethi, R.P.

    1983-12-01

    The paper reports Propionibacterium shermanii 566 to be an efficient culture, among the three propionibacteria tested, for vitamin B/sub 12/ fermentation from whey. On the basis of the results observed and expected values calculated from simulated equations, 24 hours old inoculum, 5 mg/iron and 4% whey lactose concentration were selected as the optimal values for the fermentation. Carbon mixture of whey lactose and D-glucose (3.6% + 0.4%) and supplementation of whey with 0.5% (NH/sub 4/)/sub 2/HPO/sub 4/ further enhanced the yield of the metabolite. Under optimum cultural conditions, the organism metabolized 5.12 ..mu..g vitamin B/sub 12//ml culture, subsequently reducing the BOD by 90%, thereby reducing the pollution problems.

  4. Effects of B{sub 2}O{sub 3} in precursor B powder on MgB{sub 2} critical current density

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Sihai, E-mail: sihai@uow.edu.a [Institute for Superconducting and Electronic Material, University of Wollongong, Northfields Avenue, Wollongong NSW2522 (Australia); Zhang Yun; Dou Shixue [Institute for Superconducting and Electronic Material, University of Wollongong, Northfields Avenue, Wollongong NSW2522 (Australia)

    2010-12-15

    A purifying process was used to remove the B{sub 2}O{sub 3} from the oxidized B powder. The samples made with purified B powder show higher J{sub c}. The improvement of the J{sub c} was attributed to the remove of the B{sub 2}O{sub 3} from the B powder, and correspondingly, causing less MgO in the MgB{sub 2} during the later sintering.

  5. Measurement of the lifetime of the CP pair component of B{sub s}{sup 0} in LHCb. Validation of the phototubes of the pre-shower; Mesure du temps de vie de la composante CP paire du B{sub s}{sup 0} dans LHCb. Qualification des phototubes du preshower

    Energy Technology Data Exchange (ETDEWEB)

    Borras, D

    2006-10-15

    This manuscript discusses a twofold research: an instrumental work and a prospective physics study both conducted in the framework of the LHCb experiment (CERN), foreseen to start at the Spring 2008. The LHC machine is a proton-proton collider clocked at 40 MHz and delivering a center-of-mass energy of 14 TeV. At nominal luminosity, about 10{sup 12} pairs of b-particles will be produced in LHCb. After the remarkable achievements of the B factories (BaBar and Belle), it is established that the Standard Model (through the CKM mechanism) is the dominant source of CP violation in the B system. Moreover, no significant deviation to the Standard Model predictions is observed in the whole Flavour Physics data up to now. In this scope, the large statistics which will be available at LHCb should allow to reach rare decays potentially sensitive to New Physics contribution. it will also allow to perform precision measurements and deeply test the global consistency of the CKM predictions, in particular with the B{sub s}{sup 0} particles. This document describes a prospective study about the measurement of the lifetime of the short component of the B{sub s}{sup 0} meson, reconstructed in the final state B{sub s}{sup 0} {yields} D{sub s}{sup +}D{sub s}{sup -}, where the D{sub s} meson decays in KK{pi}. It has been shown that LHCb should reach a 2% precision on this observable for a nominal year of data taking, yielding interesting constraints on {delta}{gamma}{sub s}/{gamma}{sub s}. On the instrumentation side, the team I belong to has the charge of the entire readout of the Pre-Shower (PS) detector of the LHCb spectrometer (design, construction and qualification). My contribution was devoted to the operation of a dedicated test bench aimed at qualifying the phototubes reading the PS detector. The photodetectors which have been retained are the 64-anodes PMTs produced by the Hamamatsu company. The main physics specifications for these devices were concerning the uniformity of

  6. Determination of vitamin B/sub 6/ bioavailability in animal tissues using intrinsic and extrinsic labeling in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Ink, S.L.; Gregory, J.F. III; Sartain, D.B.

    The effect of thermal processing on the bioavailability of vitamin B/sub 6/ in liver and muscle was examined by radioisotopic enrichment of these tissues. Rats were fed a single gelled test meal containing rat liver or muscle intrinsically enriched by vascular perfusion with (/sup 3/H)vitamin B/sub 6/ or a gelled test meal containing (/sup 3/H)pyridoxine (PN). Diets were extrinsically enriched with (/sup 14/C)PN to permit a direct comparison of enrichment methods. Absorption and metabolism were examined by analysis of tissues and excreta 24 h after the test meal had been consumed. The bioavailability of (/sup 3/H)B/sub 6/ vitamers in the raw tissues was equivalent to that of (/sup 3/H)PN in controls. Thermal processing of the tissues (121/sup 0/C, 45 min) induced destruction of 25-30% of the (/sup 3/H)B/sub 6/ vitamers and weakly reduced (less than or equal to10%) the utilization of the remaining(/sup 3/H)B/sub 6/ vitamers. The presence of monosodium glutamate (MSG) during thermal processing did not alter the results. The utilization of (/sup 14/C)PN was unaffected by diet composition. These data demonstrate the high bioavailability of vitamin B/sub 6/ in animal-derived foods and support the use of isotopic enrichment methods as an alternative to conventional bioassay procedures.

  7. Cutting tool performance enhancement by using a B{sub 4}C/BCN/C-BN multilayer system

    Energy Technology Data Exchange (ETDEWEB)

    Bejarano Gaitan, G. [Technological Development Center ASTIN-SENA, Cali (Colombia); Group of Corrosion and Protection, University of Antioquia, Medellin (Colombia); Caicedo, J.C. [Technological Development Center ASTIN-SENA, Cali (Colombia); Excellence Center for Novel Materials, Universidad del Valle, Cali (Colombia); Prieto, P. [Excellence Center for Novel Materials, Universidad del Valle, Cali (Colombia); Balogh, Adam G. [Institute of Materials Science, Darmstadt University of Technology (Germany)

    2007-07-01

    Thin films of B{sub 4}C/BCN/c-BN multilayers were deposited on to AISI M2 high speed steel substrates by rf. (13.56 MHz) multi-target magnetron sputtering from high purity (99.99%) h-BN and a (99.5%)B{sub 4}C target, in Ar(90%)/N{sub 2}(10%) gasmixture. For their deposition we varied the bias voltage of the B{sub 4}C films between -50 and -250 V and, for the BCN coatings the nitrogen gas flow from 3% to 12%. A 300-nm thick TiN buffer layer was first deposited to improve the adhesion of all samples. Mechanical properties like hardness, elastic Young modulus, and adhesion were determined by nanoindentation and scratch measurements. Finally, cutting tools were carried out. Tool performance was registered as functions of bilayer numbers showed enhancement between 60% and 107% and a surface roughness reduction of 60% for cutting tools coated with 16 bilayers, compared to uncoated tools. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. m{sub b} and f{sub B{sub s}} from a combination of HQET and QCD

    Energy Technology Data Exchange (ETDEWEB)

    Guazzini, D.; Sommer, R. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Tantalo, N. [Istituto Nazionale di Fisica Nucleare, Rome (Italy)]|[Centro E. Fermi, Rome (Italy)

    2006-10-15

    We compute the mass of the b-quark and the B{sub s} meson decay constant in quenched lattice QCD using a combination of HQET and the standard relativistic QCD Lagrangian. We start from a small volume, where one can directly deal with the b-quark, and compute the evolution to a big volume, where the finite size effects are negligible through step scaling functions which give the change of the observables when L is changed to 2L. In all steps we extrapolate to the continuum limit, separately in HQET and in QCD for masses below m{sub b}. The point m{sub b} is then reached by an interpolation of the continuum results. With r{sub 0}=0.5 fm and the experiment B{sub s} and K masses we find f{sub B{sub s}}=191(6) MeV and the renormalization group invariant mass M{sub b}=6.89(11) GeV, translating into anti m{sub b}(anti m{sub b})=4.42(7) GeV in the MS scheme. (orig.)

  9. Biochemical and molecular aspects of mammalian susceptibility to aflatoxin B{sub 1} carcinogenicity

    Energy Technology Data Exchange (ETDEWEB)

    Massey, T.E.; Stewart, R.K. [Queen`s Univ., Kingston, Ontario (Canada); Daniels, J.M. [Environmental Health Centre, Ottawa, Ontario (Canada)] [and others

    1995-03-01

    Aflatoxin B{sub 1} (AFB{sub 1}) is a fungal toxin that has been implicated as a causative agent in human hepatic and extrahepatic carcinogenesis. In this review, the mechanisms involved in AFB{sub 1} toxicity are delineated, in order to describe the features that make a specific cell, tissue, or species susceptible to the mycotoxin. Important considerations include: (i) different mechanisms for bioactivation of AFB{sub 1} to its ultimate carcinogenic epoxide metabolite; (ii) the balance between bioactivation to and detoxification of the epoxide; (iii) the interaction of AFB{sub 1} epoxide with DNA and the mutational events leading to neoplastic transformation; (iv) the role of cytotoxicity in AFB{sub 1} carcinogenesis; (v) the significance of nonepoxide metabolites in toxicity; and (vi) the contribution of mycotoxin-unrelated disease processes. Although considerable controversy remains about the importance of specific events, a great deal has been learned about biochemical and molecular actions of AFB{sub 1}. 157 refs., 4 figs., 1 tab.

  10. Charmless non-leptonic B{sub s} decays to PP, PV and VV final states in the pQCD approach

    Energy Technology Data Exchange (ETDEWEB)

    Ali, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kramer, G. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Li, Y.; Lue, C.D.; Shen, Y.L.; Wang, W.; Wang, Y.M. [Institute of High Energy Physics, CAS, Beijing (China)

    2007-03-15

    We calculate the CP-averaged branching ratios and CP-violating asymmetries of a number of two-body charmless hadronic decays B{sub s}{sup 0}{yields}PP,PV,VV in the perturbative QCD (pQCD) approach to leading order in {alpha}{sub s} (here P and V denote light pseudoscalar and vector mesons, respectively). The mixinginduced CP violation parameters are also calculated for these decays. We also predict the polarization fractions of B{sub s}{yields}VV decays and find that the transverse polarizations are enhanced in some penguin dominated decays such as B{sub s}{sup 0}{yields}K{sup *}K{sup *}, K{sup *}{rho}. Some of the predictions worked out here can already be confronted with the recently available data from the CDF collaboration on the branching ratios for the decays B{sub s}{sup 0}{yields}K{sup +}{pi}{sup -}, B{sub s}{sup 0}{yields}K{sup +}K{sup -} and the CP-asymmetry in the decay B{sub s}{sup 0}{yields}K{sup +}{pi}{sup -}, and are found to be in agreement within the current errors. A large number of predictions for the branching ratios, CP-asymmetries and vector-meson polarizations in B{sub s}{sup 0} decays, presented in this paper and compared with the already existing results in other theoretical frameworks, will be put to stringent experimental tests in forthcoming experiments at Fermilab, LHC and Super B-factories. (orig.)

  11. Effect of annealing on the structural and magnetic properties of (Fe{sub 1−x}Co{sub x}){sub 83}B{sub 17} metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Bhagat, Neeru, E-mail: neerubhagat@hotmail.com [Department of Applied Science, Symbiosis Institute of Technology, SIU, Lavale, Mulshi, Pune 412115 (India); Gupta, Ajay [Center for Spintronic Materials, Amity University, Sector 125, Noida (India); Reddy, V.R. [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore (India); Pandey, Brajesh, E-mail: bpandey@gmail.com [Department of Applied Science, Symbiosis Institute of Technology, SIU, Lavale, Mulshi, Pune 412115 (India)

    2015-05-01

    Amorphous alloys of (Fe{sub 1−x}Co{sub x}){sub 83}B{sub 17} (x=22, 25.3, 28.4) in the vicinity of 25 at% of Co were prepared by melt spun technique. The samples were annealed at different temperatures and the changes in structural and magnetic properties have been studied. Phase stabilization and magnetic properties of amorphous alloys were studies using X-ray diffraction and Mössbauer spectroscopy. The result shows anomalies in structure and in magnetic properties in the studied samples. Annealing at 475 °C brings about the formation of complete and stable crystalline structure. At this stage multiple crystalline phases have been observed. Mössbauer spectroscopy also revealed that two phases of Fe{sub 3}B were formed along with stable Fe{sub 3}Co phase. - Highlights: • Using melt spun technique alloys of (Fe{sub 1−x}Co{sub x}){sub 83}B{sub 17} (x=22, 25.3, 28.4) in amorphous phase were prepared. • Crystalline phase increases with increasing the Co concentration. • Appearance of one crystalline phase is observed when samples annealing at 345 °C. • Annealing at higher temperature leads to emergence of multiple crystalline phases. • Different phases of Fe–Co, and Fe–Co–B were identified.

  12. Synthesis and electromagnetic properties of U-type hexaferrites Ba{sub 4}B{sub 2}Fe{sub 36}O{sub 60} (B: Co, Ni, Cu)

    Energy Technology Data Exchange (ETDEWEB)

    Shannigrahi, S.R., E-mail: santi-s@imre.a-star.edu.sg [Institute of Materials Research and Engineering, A-STAR (Agency for Science Technology and Research), 3 Research Link, Singapore 117602 (Singapore); Au, W.Q.; Suresh Kumar, V. [School of Materials Science and Engineering, Nanyang Technological University, Nanyang Avenue 50, Singapore 639798 (Singapore); Liu, L.; Yang, Z.H. [Temasek Laboratories, National University of Singapore, Singapore 117508 (Singapore); Cheng, C. [School of Materials Science and Engineering, Nanyang Technological University, Nanyang Avenue 50, Singapore 639798 (Singapore); Tan, C.K.I. [Institute of Materials Research and Engineering, A-STAR (Agency for Science Technology and Research), 3 Research Link, Singapore 117602 (Singapore); Ramanujan, R.V. [School of Materials Science and Engineering, Nanyang Technological University, Nanyang Avenue 50, Singapore 639798 (Singapore)

    2013-01-15

    Polycrystalline samples of U-type hexaferrites Ba{sub 4}B{sub 2}Fe{sub 36}O{sub 60} (B: Co, Ni and Cu) were synthesized using a modified solid state reaction technique. The sintered hexaferrites were tested for their crystalline quality using x-ray diffraction technique and their magnetic properties using the Physical Property Measurement System (PPMS). The individual ferrites were further used as fillers to prepare composites using a polyethylene matrix. The composites were tested for their complex permittivity and permeability spectra and finally reflection loss spectra were derived from these results. Among the studied composites, lowest and highest values of saturation magnetization were 25 and 35 emu/g, respectively, for the Cu doped hexaferrites and the Co doped hexaferrites. All the studied composites demonstrated microwave absorption property, which was tunable by manipulating the sample thickness. Co-doped composites offered the highest absorption ({approx}98%) and were found the most suitable to suppress electromagnetic interference. - Research highlights:: Black-Right-Pointing-Pointer Synthesis of U-type hexaferrites: Ba{sub 4}B{sub 2}Fe{sub 36}O{sub 60} (B: Co, Ni, Cu) using modified solid state reaction process. Black-Right-Pointing-Pointer Developed composites using ferrite fillers and a polyethylene matrix. Black-Right-Pointing-Pointer Characterization of electromagnetic properties of the composites. Black-Right-Pointing-Pointer Cobalt-doped composites have the highest electromagnetic absorption ({approx}98%).

  13. Influence of protein deficient diet, vitamin B[sub]2[/sub] supplementation and physical training on serum composition of polyunsaturated fatty acids (PUFAs) in rats.

    Science.gov (United States)

    Lewicka, Aneta; Lewicki, Sławomir; Kłos, Anna; Dębski, Bogdan; Kurył, Tomasz; Bertrandt, Jerzy

    2017-05-11

    [b]Introduction[/b]. Prolonged shortages of protein in the diet significantly alter the composition and content of polyunsaturated fatty acids (PUFA) in tissues and body fluids. One of nutritional factors which may reduce negative effects of protein malnutrition might be vitamin B[sub]2[/sub] due to its influence on lipids metabolism. [b]Objective. [/b]The aim of the study was to investigate the influence of low protein (LP) diet enriched with vitamin B[sub]2[/sub] on the content and composition of PUFA in the blood serum of rats treated with dosed physical exercise. [b]Materials and method. [/b]The experiment was carried out for 3 months on 72 growing male Wistar rats divided into 5 groups. Animals were fed ad libitum on a diet with an energy value of 350 kcal/100 g, in which 4.5% of the energy was provided by protein. In the control diet, 20% of the energy was provided by protein. Two groups were fed the diet enriched with vitamin B2. The two groups of tested animals were trained for 5 days a week. [b]Results.[/b] LP diet caused a decrease in α-linolenic acid (ALA) after 30 days, and a decrease in docosahexaenoic acid (DHA) after 60 days of experiment, compared with rats fed the control diet. After 60 and 90 days of the experiment, a significant decrease was noted in arachidonic acid (AA) in serum of trained rats, compared with sedentary rats fed the LP diet. Physical activity increased LA (mainly on day 30), EPA (on day 90) and reduced AA content (on day 90) in serum of rats fed the LP diet. B2 supplementation in the trained LP group did not change the EPA and AA dependence; however, there was a decrease in LA content in comparison to the non-supplemented trained group. [b]Conclusions. [/b] Results of this study suggest that all investigated factors (protein deficiency, physical exercise and supplementation of vitamin B2) have significant impact on PUFA composition of serum in rats.

  14. Oscillatory magnetic fluctuations near the superconductor-to-ferromagnet transition in ErRh/sub 4/B/sub 4/

    Energy Technology Data Exchange (ETDEWEB)

    Moncton, D.E.; McWhan, D.B.; Schmidt, P.H.; Shirane, G.; Thomlinson, W.; Maple, M.B.; MacKay, H.B.; Woolf, L.D.; Fisk, Z.; Johnston, D.C.

    1980-12-22

    Small-angle neutron experiments show that near the transition from superconductor to ferromagnet in ErRh/sub 4/B/sub 4/ scattering peaks occur at a wave vector Vertical Barq/sub s/Vertical Bar=0.06 A/sup -1/. The temperature and wave-vector dependence suggest this signal is due to oscillatory magnetization fluctuations caused by the electromagnetic coupling of magnetic and superconducting order parameters. The ferromagnetic Bragg scattering shows a 5% hysteresis and transition-temperature--smearing effects which are also due to magnetic-superconducting interactions.

  15. Deposition of B{sub 4}C/BCN/c-BN multilayered thin films by r.f. magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Bejarano, G. [Laboratorio de Recubrimientos Duros del CDT-ASTIN SENA, Cali (Colombia); Caicedo, J.M. [Laboratorio de Recubrimientos Duros del CDT-ASTIN SENA, Cali (Colombia); Baca, E. [Departamento de Fisica, Universidad del Valle, A.A. 25360, Cali (Colombia); Prieto, P. [Departamento de Fisica, Universidad del Valle, A.A. 25360, Cali (Colombia)]. E-mail: pprieto@calima.univalle.edu.co; Balogh, A.G. [Institute for Material Science, Darmstadt University of Technology (Germany); Enders, S. [Max Plank Institute, Department of Material Research, Stuttgart (Germany)

    2006-01-03

    Thin films of cubic boron nitride (c-BN) and B{sub 4}C/BCN/c-BN multilayers, were deposited by r.f. (13.56 MHz) multi-target magnetron sputtering from high-purity (99.99%) h-BN and a (99.5%) B{sub 4}C targets, in an Ar (90%)/N{sub 2} (10%) gas mixture. Films were deposited onto silicon substrates with (100) orientations at 300 {sup o}C, with r.f. power density near 7 W/cm{sup 2}. In order to obtain the highest fraction of the c-BN phase, an r.f. substrate bias voltage between - 100 and - 300 V was applied during the initial nucleation process and - 50 to - 100 V during the film growth. Additionally, B{sub 4}C and BCN films were deposited and analyzed individually. For their deposition, we varied the bias voltage of the B{sub 4}C films between - 50 and - 250 V, and for the BCN coatings, the nitrogen gas flow from 3% to 12%. A 300-nm-thick TiN buffer layer was first deposited to improve the adhesion of all samples. X-ray diffraction patterns revealed the presence of c-BN (111) and h-BN phases. FTIR spectroscopy measurements indicate the presence of a peak at 780 cm{sup -} {sup 1} referred to as 'out-of-plane' h-BN vibration mode; another peak at 1100 cm{sup -} {sup 1} corresponds to the c-BN TO mode and the 'in-plane' vibration mode of the h-BN at 1400 cm{sup -} {sup 1}. BN films deposited at 300 deg. C at a pressure of 4.0 Pa and under - 150 V of nucleation r.f. bias, applied for 35 min, presented the highest c-BN fraction, near 85%. By using 32 layers, it was possible to deposit a 4.6-{mu}m-thick c-BN film with adequate mechanical properties and good adhesion to the substrate.

  16. Temperature dependence of the coercive field of gas atomized Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1}

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Escorial, A., E-mail: age@cenim.csic.es [CENIM-CSIC, Avda, Gregorio del Amo, 8, 28040 Madrid (Spain); Lieblich, M. [CENIM-CSIC, Avda, Gregorio del Amo, 8, 28040 Madrid (Spain); Hernando, A.; Aragon, A.; Marin, P. [Instituto de Magnetismo Aplicado, IMA, P.O. Box 155, 28230 Madrid (Spain)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer An anomalous thermal dependence of the coercive field of gas atomized Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} powder particles under 25 {mu}m powder particle, increasing Hc as temperature increases. Black-Right-Pointing-Pointer It is proposed that Cu rich regions at inter-grain boundaries could act as exchange decoupling regions contributing to the thermal increase of coercivity. Black-Right-Pointing-Pointer This anomalous thermal dependence points out that tailoring microstructure and size, by controlling the cooling rate of more adequate multiphase systems, could be a promising procedure to develop soft or hard magnets, avoiding Rare Earths metals that is nowadays an important target for the engineering of magnetic materials. - Abstract: In this work, the dependence of the coercive field of Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} gas atomized powder with the temperature for different particle sizes has been studied, observing an anomalous behavior in the under 25 powder particle size fraction. This unusual behavior is related with the microstructure of the powder, and is attributed to the presence of a multiphase magnetic system, with non-magnetic regions decoupling the ferromagnetic domains.

  17. Creep behavior and wear resistance of Al 5083 based hybrid composites reinforced with carbon nanotubes (CNTs) and boron carbide (B{sub 4}C)

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Ali [Faculty of Materials & Manufacturing Processes, Malek-e-Ashtar University of Technology, Tehran (Iran, Islamic Republic of); Abdollahi, Alireza, E-mail: alirezaabdollahi1366@gmail.com [Faculty of Materials & Manufacturing Processes, Malek-e-Ashtar University of Technology, Tehran (Iran, Islamic Republic of); Biukani, Hootan [Faculty of Engineering, South Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2015-11-25

    In the current research, aluminum based hybrid composite reinforced with boron carbide (B{sub 4}C) and carbon nanotubes (CNTs) was produced by powder metallurgy method. creep behavior, wear resistance, surface roughness, and hardness of the samples were investigated. To prepare the samples, Al 5083 powder was milled with boron carbide particles and carbon nanotubes using planetary ball mill under argon atmosphere with ball-to-powder weight ratio of 10:1 for 5 h. Afterwards, the milled powders were formed by hot press process at 380{sup °}C and then were sintered at 585{sup °}C under argon atmosphere for 2 h. There was shown to be an increase in hardness values of composite with an increase in B{sub 4}C content. The micrograph of worn surfaces indicate a delamination mechanism due to the presence of CNTs and abrasion mechanism in composite containing 10 vol.%B{sub 4}C. Moreover, it was shown that increasing B{sub 4}C content increases the wear resistance by 3 times under a load of 20 N and 10 times under a load of 10 N compared to CNTs-reinforced composite. surface roughness of the composite containing 5 vol.%CNT has shown to be more than other samples. The results of creep test showed that adding carbon nanotubes increases creep rate of Al 5083 alloy; however, adding B{sub 4}C decreases its creep rate. - Highlights: • Al 5083/(CNTs + B{sub 4}C) hybrid composite was produced by powder metallurgy method. • Creep behavior, wear resistance, surface roughness, and Hardness of samples were investigated. • Addition of CNTs to Al 5083 matrix reduces alloy hardness, wear resistance and creep strength. • By addition of B{sub 4}C and composite hybridization, creep strength and wear resistance increased. • Surface roughness of Al-5 vol.%CNT has shown to be more than other samples.

  18. New physics contributions to anti B{sub s} → π{sup 0}(ρ{sup 0})η{sup (')} decays

    Energy Technology Data Exchange (ETDEWEB)

    Faisel, Gaber [Sueleyman Demirel University, Department of Physics, Faculty of Arts and Sciences, Isparta (Turkey); National Taiwan University, Department of Physics, Taipei (China)

    2017-06-15

    The decay modes anti B{sub s} → π{sup 0}(ρ{sup 0})η{sup (')} are dominated by electroweak penguins that are small in the standard model. In this work we investigate the contributions to these penguins from a model with an additional U(1){sup '} gauge symmetry and show there effects on the branching ratios of anti B{sub s} → π{sup 0}(ρ{sup 0})η{sup (')}. In a scenario of the model, where Z{sup '} couplings to the left-handed quarks vanish, we show that the maximum enhancement occurs in the branching ratio of anti B{sub s}{sup 0} → π{sup 0}η{sup '} where it can reach 6 times the SM prediction. On the other hand, in a scenario of the model where Z{sup '} couplings to both left-handed and right-handed quarks do not vanish, we find that Z{sup '} contributions can enhance the branching ratio of B{sup 0}{sub s} → ρ{sup 0}η up to one order of magnitude comparing to the SM prediction for several sets of the parameter space where both ΔM{sub B{sub s}} and S{sub ψφ} constraints are satisfied. This kind of enhancement occurs for a rather fine-tuned point where the ΔM{sub B{sub s}} constraint on vertical stroke S{sub SM}(B{sub s}) + S{sub Z}{sup {sub '}} (B{sub s}) vertical stroke is fulfilled by overcompensating the SM via S{sub Z}{sup {sub '}}(B{sub s}) ≅ -2S{sub SM}(B{sub s}). (orig.)

  19. Mo{sub 2}B{sub 4}O{sub 9} - connecting borate and metal-cluster chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Martin K.; Huppertz, Hubert [Institut fuer Allgemeine, Anorganische und Theoretische Chemie, Universitaet Innsbruck (Austria); Janka, Oliver; Poettgen, Rainer [Institut fuer Anorganische und Analytische Chemie, Universitaet Muenster (Germany); Benndorf, Christopher [Institut fuer Anorganische und Analytische Chemie, Universitaet Muenster (Germany); Institut fuer Physikalische Chemie, Universitaet Muenster (Germany); Institut fuer Mineralogie, Kristallographie und Materialwissenschaften, Universitaet Leipzig (Germany); Oliveira, Marcos de Jr. [Sao Carlos Institute of Physics, University of Sao Paulo, Sao Carlos (Brazil); Eckert, Hellmut [Institut fuer Physikalische Chemie, Universitaet Muenster (Germany); Sao Carlos Institute of Physics, University of Sao Paulo, Sao Carlos (Brazil); Pielnhofer, Florian; Tragl, Amadeus-Samuel [Institut fuer Anorganische Chemie, Universitaet Regensburg (Germany); Weihrich, Richard [Institut fuer Materials Resource Management, Universitaet Augsburg (Germany); Joachim, Bastian [Institut fuer Mineralogie und Petrographie, Universitaet Innsbruck (Austria); Johrendt, Dirk [Department Chemie, Ludwig-Maximilians-Universitaet Muenchen (Germany)

    2017-06-01

    We report on the first thoroughly characterized molybdenum borate, which was synthesized in a high-pressure/high-temperature experiment at 12.3 GPa/1300 C using a Walker-type multianvil apparatus. Mo{sub 2}B{sub 4}O{sub 9} incorporates tetrahedral molybdenum clusters into an anionic borate crystal structure - a structural motif that has never been observed before in the wide field of borate crystal chemistry. The six bonding molecular orbitals of the [Mo{sub 4}] tetrahedron are completely filled with 12 electrons, which are fully delocalized over the four molybdenum atoms. This finding is in agreement with the results of the magnetic measurements, which confirmed the diamagnetic character of Mo{sub 2}B{sub 4}O{sub 9}. The two four-coordinated boron sites can be differentiated in the {sup 11}B MAS-NMR spectrum because of the strongly different degrees of local distortions. Experimentally obtained IR and Raman bands were assigned to vibrational modes based on DFT calculations. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Effect of cooling rate on the phase structure and magnetic properties of Fe{sub 26.7}Co{sub 28.5}Ni{sub 28.5}Si{sub 4.6}B{sub 8.7}P{sub 3} high entropy alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Ran; Sun, Huan; Chen, Chen [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001 (China); Han, Zhenhua [School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710068 (China); Li, Fushan, E-mail: fsli@zzu.edu.cn [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001 (China)

    2017-08-01

    Highlights: • High entropy alloy with amorphous phase and FCC solid solution phase are successfully developed respectively. • The amorphous phase exhibits better soft magnetic properties than that of the solid solution phase. • The BCC phase transformed into FCC phase, and then into BCC phase was found in this HEA. - Abstract: The effect of cooling rate on phase structure and magnetic properties of the Fe{sub 26.7}Co{sub 28.5}Ni{sub 28.5}Si{sub 4.6}B{sub 8.7}P{sub 3} high entropy alloy (HEA) was investigated. The HEA forms into amorphous phase by melt spinning method at high cooling rate and FCC solid solution phase at low cooling rate. The soft magnetic properties of the amorphous phase (saturation magnetization B{sub s} of 1.07T and coercivity H{sub c} of 4 A/m) are better than that of the solid solution phase (B{sub s} of 1.0 T and H{sub c} of 168 A/m). In order to study the phase evolution of the present HEA, anneal experiments were conducted. It is found that crystallization products of amorphous phase are solid solution phase which constitute much of FCC and a small amount of BCC. BCC phase transforms into FCC phase, and then into BCC phase with the increase of annealing temperature.

  1. Synthesis and characterization of the lead borate Pb{sub 6}B{sub 12}O{sub 21}(OH){sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Schoenegger, Sandra; Ortner, Teresa S.; Wurst, Klaus; Heymann, Gunter; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie

    2016-11-01

    A lead borate with the composition Pb{sub 6}B{sub 12}O{sub 21}(OH){sub 6} was synthesized through a hydrothermal synthesis, using lead metaborate in combination with sodium nitrate and potassium nitrate. The compound crystallizes in the trigonal, non-centrosymmetric space group P3{sub 2} (no. 145) with the lattice parameters a = 1176.0(4), c = 1333.0(4) pm, and V = 0.1596(2) nm{sup 3}. Interestingly, the data of Pb{sub 6}B{sub 12}O{sub 21}(OH){sub 6} correct the structure of a literature known lead borate with the composition ''Pb{sub 6}B{sub 11}O{sub 18}(OH){sub 9}''. For the latter compound, nearly identical lattice parameters of a = 1176.91(7) and c = 1333.62(12) pm were reported, possessing a crystal structure, in which the localization and refinement of one boron atom was obviously overlooked. The structure of Pb{sub 6}B{sub 12}O{sub 21}(OH){sub 6} is built up from trigonal planar BO{sub 3} and tetrahedral BO{sub 4} groups forming complex chains. The Pb{sup 2+} cations are located between neighboring polyborate chains. The here reported compound Pb{sub 6}B{sub 12}O{sub 21}(OH){sub 6} and ''Pb{sub 6}B{sub 11}O{sub 18}(OH){sub 9}'' were, however, produced under different synthesis conditions. While ''Pb{sub 6}B{sub 11}O{sub 18}(OH){sub 9}'' was synthesized via a hydrothermal synthesis including ethylenediamine and acetic acid, the here reported lead borate Pb{sub 6}B{sub 12}O{sub 21}(OH){sub 6} could be obtained under moderate hydrothermal conditions (240 C) without the addition of organic reagents.

  2. The effect of non-magnetic dilution of the Tb sublattice in TbCo{sub 3}B{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Wolfson, Erez J [Department of Nuclear Engineering, Ben-Gurion University of the Negev, PO Box 653, Beer-Sheva 84105 (Israel); Caspi, El' ad N; Ettedgui, Hanania [Nuclear Research Centre-Negev, PO Box 9001, Beer-Sheva 84190 (Israel); Shaked, Hagai [Department of Physics, Ben-Gurion University, PO Box 653, Beer-Sheva 84105 (Israel); Avdeev, Maxim, E-mail: ejwolf@gmail.co, E-mail: wolfsoy@bgu.ac.i [Bragg Institute, ANSTO, PMB 1, Menai, NSW 2234 (Australia)

    2010-01-20

    Solid solutions of Tb{sub 1-x}Y{sub x}Co{sub 3}B{sub 2} (x = 0.05, 0.1, 0.25, 0.4 and 0.5) were studied by neutron powder diffraction, x-ray diffraction, AC susceptibility and SQUID magnetization measurements. Their magnetic and crystallographic properties were deduced and examined together with those previously published for the end compounds (x = 0,1). These solid solutions have hexagonal symmetry and are paramagnetic at RT, and undergo a magnetic ordering transition of the Co sublattice, with the magnetic moments along the hexagonal axis, at T{sub Co}approx150(15) K, independent of Y concentration. A second magnetic ordering transition of the Tb sublattice T{sub Tb}<=30 K accompanied by the rotation of the magnetic moments towards the basal plane, was observed for solid solutions with Y concentration x<=0.25. This transition was also found to be accompanied by a crystallographic symmetry decrease. Unexpectedly, neutron powder diffraction showed that the magnitude of the ordered magnetic moment of the Tb ion decreases with Tb concentration.

  3. Lowest-lying even-parity anti B{sub s} mesons: heavy-quark spin-flavor symmetry, chiral dynamics, and constituent quark-model bare masses

    Energy Technology Data Exchange (ETDEWEB)

    Albaladejo, M.; Fernandez-Soler, P.; Nieves, J.; Ortega, P.G. [Centro Mixto CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular (IFIC), Institutos de Investigacion de Paterna, Aptd. 22085, Valencia (Spain)

    2017-03-15

    The discovery of the D{sup *}{sub s0}(2317) and D{sub s1}(2460) resonances in the charmed-strange meson spectra revealed that formerly successful constituent quark models lose predictability in the vicinity of two-meson thresholds. The emergence of non-negligible effects due to meson loops requires an explicit evaluation of the interplay between Q anti q and (Q anti q)(q anti q) Fock components. In contrast to the c anti s sector, there is no experimental evidence of J{sup P} = 0{sup +}, 1{sup +} bottom-strange states yet. Motivated by recent lattice studies, in this work the heavy-quark partners of the D{sub s0}{sup *}(2317) and D{sub s1}(2460) states are analyzed within a heavy meson chiral unitary scheme. As a novelty, the coupling between the constituent quark-model P-wave anti B{sub s} scalar and axial mesons and the anti B{sup (*)}K channels is incorporated employing an effective interaction, consistent with heavy-quark spin symmetry, constrained by the lattice energy levels. (orig.)

  4. Radiation induced defects in Sr{sub 2}B{sub 5}O{sub 9}Br:Ce{sup 3+} storage phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Sidorenko, A V [Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Bos, A J J [Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Dorenbos, P [Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Eijk, C W E van [Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Rodnyi, P A [St Petersburg State Technical University, Polytekhnicheskaya 29, 195251 St Petersburg (Russian Federation); Berezovskaya, I V [A V Bogatsky Physico-Chemical Institute, Ukranian Academy of Science, 65080 Odessa (Ukraine); Dotsenko, V P [A V Bogatsky Physico-Chemical Institute, Ukranian Academy of Science, 65080 Odessa (Ukraine); Guillot-Noel, O [Laboratoire de Chimie Appliquee de l' Etat Solide, UMR 7574, ENSCP, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); Gourier, D [Laboratoire de Chimie Appliquee de l' Etat Solide, UMR 7574, ENSCP, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France)

    2004-06-16

    Radiation induced defects in polycrystalline pure and Ce{sup 3+} doped Sr{sub 2}B{sub 5}O{sub 9}Br storage phosphors have been investigated using EPR and optical absorption methods. The EPR of irradiated pure Sr{sub 2}B{sub 5}O{sub 9}Br represents two overlapping spectra in the 335-340 mT range from paramagnetic electron and hole trapping centres, which are stable at room temperature. These centres are attributed to F(Br{sup -}) and O{sub Br}{sup -} centres, i.e. an electron trapped in a bromine vacancy and a hole trapped on an oxygen ion at a bromine site. The 1s {yields} 2p transitions of F(Br{sup -}) centres cause the optical absorption band at 560 nm. Another observed absorption band at 365 nm was attributed to the transitions of O{sup -} centres. Thus electron and hole trapping in pure Sr{sub 2}B{sub 5}O{sub 9}Br occurs in V{sub Br} and O{sub Br}{sup 2-} aggregates, which are created during the synthesis. EPR and optical absorption measurements on Ce{sup 3+} doped Sr{sub 2}B{sub 5}O{sub 9}Br reveal similar defects as in pure material. It is very likely that the same defects take part in the processes of thermally and photo-stimulated luminescence.

  5. Coaxial triple-layered versus helical Be{sub 6}B{sub 11}{sup -} clusters. Dual structural fluxionality and multifold aromaticity

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jin-Chang [Institute of Materials Science and Department of Chemistry, Xinzhou Teachers University, Shanxi (China); Nanocluster Laboratory, Institute of Molecular Science, Shanxi University, Taiyuan (China); Feng, Lin-Yan; Wang, Ying-Jin; Zhai, Hua-Jin [Nanocluster Laboratory, Institute of Molecular Science, Shanxi University, Taiyuan (China); Jalife, Said; Vasquez-Espinal, Alejandro; Cabellos, Jose Luis; Pan, Sudip; Merino, Gabriel [Departamento de Fisica Aplicada, Centro de Investigacion y de Estudios Avanzados, Unidad Merida, km 6 Antigua carretera a Progreso, Merida, Yuc. (Mexico)

    2017-08-14

    Two low-lying structures are unveiled for the Be{sub 6}B{sub 11}{sup -} nanocluster system that are virtually isoenergetic. The first, triple-layered cluster has a peripheral B{sub 11} ring as central layer, being sandwiched by two Be{sub 3} rings in a coaxial fashion, albeit with no discernible interlayer Be-Be bonding. The B{sub 11} ring revolves like a flexible chain even at room temperature, gliding freely around the Be{sub 6} prism. At elevated temperatures (1000 K), the Be{sub 6} core itself also rotates; that is, two Be{sub 3} rings undergo relative rotation or twisting with respect to each other. Bonding analyses suggest four-fold (π and σ) aromaticity, offering a dilute and fluxional electron cloud that lubricates the dynamics. The second, helix-type cluster contains a B{sub 11} helical skeleton encompassing a distorted Be{sub 6} prism. It is chiral and is the first nanosystem with a boron helix. Molecular dynamics also shows that at high temperature the helix cluster readily converts into the triple-layered one. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Structure, growth and properties of a novel polar material, KSr{sub 4}B{sub 3}O{sub 9}

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Wenwu [Xinjiang Key Laboratory of Electronic Information Materials and Devices, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 40-1 South Beijing Road, Urumqi 830011 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Pan, Shilie, E-mail: slpan@ms.xjb.ac.cn [Xinjiang Key Laboratory of Electronic Information Materials and Devices, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 40-1 South Beijing Road, Urumqi 830011 (China); Wang, Yongjiang [Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), CAS (China); Yang, Zhihua; Wang, Xian; Han, Jian [Xinjiang Key Laboratory of Electronic Information Materials and Devices, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 40-1 South Beijing Road, Urumqi 830011 (China)

    2012-11-15

    A novel polar material, KSr{sub 4}B{sub 3}O{sub 9}, has been obtained by the high temperature solution method for the first time. It crystallizes in the polar space group Ama2. The material exhibits a three-dimensional structure consisting of interconnecting KO{sub 10} groups, SrO{sub x} (x=8, 9) units and isolated BO{sub 3} triangles. DSC/TG curve shows that KSr{sub 4}B{sub 3}O{sub 9} melts incongruently. The calculated band structures and the density of states of KSr{sub 4}B{sub 3}O{sub 9} suggest that its direct gap is 3.897 eV. The absorption spectrum indicates the absorption edge of KSr{sub 4}B{sub 3}O{sub 9} is about 302 nm. It produces SHG intensity about as large as that of KH{sub 2}PO{sub 4} (KDP) and is phase matchable. - Graphical abstract: Viewed along the c-axis, B(2)O{sub 3} triangles and B(3)O{sub 3} triangles are parallel with the (0 1 0) face and opposite to each other. However, all the B(1)O{sub 3} triangles have the same direction along the c-axis. So the main SHG efficiency of the compound comes from B(1)O{sub 3} triangles according to the anion group theory. Highlights: Black-Right-Pointing-Pointer A polar material, KSr{sub 4}B{sub 3}O{sub 9}, has been obtained by high temperature solution method. Black-Right-Pointing-Pointer The material consists of KO{sub 10} units, SrO{sub x}(x=8, 9) units and isolated BO{sub 3} units. Black-Right-Pointing-Pointer KSr{sub 4}B{sub 3}O{sub 9} produces SHG intensity as large as that of KDP and is phase matchable. Black-Right-Pointing-Pointer The absorption edge of KSr{sub 4}B{sub 3}O{sub 9} is about 302 nm.

  7. Synthesis, crystal structure, spectrum properties, and electronic structure of a new three-borate Ba{sub 4}Na{sub 2}Zn{sub 4}(B{sub 3}O{sub 6}){sub 2}(B{sub 12}O{sub 24}) with two isolated types of blocks: 3[3Δ] and 3[2Δ + 1T

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xuean, E-mail: xueanchen@bjut.edu.cn [College of Materials Science and Engineering, Beijing University of Technology, Ping Le Yuan 100, Beijing 100124 (China); Chen, Yanjun; Sun, Chong; Chang, Xinan [College of Materials Science and Engineering, Beijing University of Technology, Ping Le Yuan 100, Beijing 100124 (China); Xiao, Weiqiang [Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124 (China)

    2013-08-15

    Graphical abstract: Ba{sub 4}Na{sub 2}Zn{sub 4}(B{sub 3}O{sub 6}){sub 2}(B{sub 12}O{sub 24}) contains complicated porous anionic layers composed of ZnO{sub 4} tetrahedra, [B{sub 3}O{sub 6}]{sup 3−} rings with notation of 3[3Δ], and [B{sub 12}O{sub 24}]{sup 12−} groups built up from four BO{sub 4} tetrahedra and eight BO{sub 3} triangles with notation of 2 × {2 × (3[2Δ + 1T])}. The anionic layers stack along c-axis, with the intralayer open channels and interlayer void spaces occupied by Na{sup +} or Ba{sup 2+} cations to balance charge. Highlights: •Ba{sub 4}Na{sub 2}Zn{sub 4}(B{sub 3}O{sub 6}){sub 2}(B{sub 12}O{sub 24}) has been prepared by solid state reaction method. •It has a layered structure consisting of ZnO{sub 4} tetrahedra, [B{sub 3}O{sub 6}]{sup 3−} rings, and [B{sub 12}O{sub 24}]{sup 12−} groups. •The IR spectrum confirmed the presence of both BO{sub 3} and BO{sub 4} groups. •UV–vis diffuse reflectance spectrum revealed a band gap of about 3.13 eV. •Band structure calculations indicated that it is an indirect band material. -- Abstract: A new barium sodium zincoborate, Ba{sub 4}Na{sub 2}Zn{sub 4}(B{sub 3}O{sub 6}){sub 2}(B{sub 12}O{sub 24}), has been prepared by solid state reaction method below 750 °C. Single-crystal XRD analysis showed that it crystallizes in the triclinic space group P1{sup ¯} with a = 7.0288(14) Å, b = 7.0687(14) Å, c = 17.501(4) Å, α = 91.92(3)°, β = 96.46(3)°, γ = 119.72(3)°, Z = 1. The crystal structure exhibits complicated porous anionic layers composed of ZnO{sub 4} tetrahedra, [B{sub 3}O{sub 6}]{sup 3−} rings with notation of 3[3Δ], and [B{sub 12}O{sub 24}]{sup 12−} groups built up from four BO{sub 4} tetrahedra and eight BO{sub 3} triangles with notation of 2 × {2 × (3[2Δ + 1T])}. The anionic layers stack along c-axis, with the intralayer open channels and interlayer void spaces occupied by Na{sup +} or Ba{sup 2+} cations to balance charge. The IR spectrum further confirmed the

  8. Nido-Carborane building-block reagents. 2. Bulky-substituent (alkyl)/sub 2/C/sub 2/B/sub 4/H/sub 6/ derivatives and (C/sub 6/H/sub 5/)/sub 2/C/sub 2/B/sub 4/H/sub 6/: synthesis and properties

    Energy Technology Data Exchange (ETDEWEB)

    Boyter, H.A. Jr.; Grimes, R.N.

    1988-09-07

    The preparation and chemistry of nido-2,3-R/sub 2/C/sub 2/C/sub 2/B/sub 4/H/sub 6/ carboranes in which R is n-butyl, isopentyl, n-hexyl, and phenyl was investigated in order to further assess the steric and electronic influence of the R groups on the properties of the nido-C/sub 2/B/sub 4/ cage, especially with respect to metal complexation at the C/sub 2/B/sub 3/ face and metal-promoted oxidative fusion. The three dialkyl derivatives were prepared from the corresponding dialkylacetylenes via reaction with B/sub 5/H/sub 9/ and triethylamine, but the diphenyl compound could not be prepared in this manner and was obtained instead in a thermal reaction of B/sub 5/H/sub 9/ with diphenylacetylene in the absence of amine. All four carboranes are readily bridge-deprotonated by NaH in THF, and the anions of the dialkyl species, on treatment with FeCl/sub 2/ and air oxidation, generate the respective R/sub 4/C/sub 4/B/sub 8/H/sub 8/ carborane fusion products were R = n-C/sub 4/H/sub 9/, i-C/sub 5/H/sub 11/ or n-C/sub 6/H/sub 13/. The diphenylcarborane anion Ph/sub 2/C/sub 2/B/sub 4/H/sub 5//sup /minus// did not form detectable metal complexes with Fe/sup 2+/, Co/sup 2+/, or Ni/sup 2+/, and no evidence of a Ph/sub 4/C/sub 4/B/sub 8/H/sub 8/ fusion product has been found. Treatment of Ph/sub 2/C/sub 2/B/sub 4/H/sub 6/ with Cr(CO)/sub 6/ did not lead to metal coordination of the phenyl rings, unlike (PhCH/sub 2/)/sub 2/C/sub 2/B/sub 4/H/sub 6/, which had previously been shown to form mono- and bis(tricarbonylchromium) complexes. However, the reaction of Ph/sub 2/C/sub 2/B/sub 4/H/sub 5//sup /minus//, CoCl/sub 2/, and (PhPCH/sub 2/)/sub 2/ did give 1,1-(Ph/sub 2/PCH/sub 2/)/sub 2/-1-Cl-1,2,3-Co(Ph/sub 2/C/sub 2/B/sub 4/H/sub 4/), the only case in which metal complexation of the diphenylcarborane was observed. 14 references, 3 figures, 3 tables.

  9. MnO - induced crystallization and optical characteristics of PbO-Sb{sub 2}O{sub 3}-B{sub 2}O{sub 3} glass system

    Energy Technology Data Exchange (ETDEWEB)

    Satyanarayana, T; Nagarjuna, G; Veeraiah, N [Department of Physics, Acharya Nagarjuna University-Nuzvid Campus, Nuzvid - 521 201, A.P (India); Raghavaiah, B V [St. Ann' s College of Engineering and Technology, Chirala-523 187, A.P (India); Mohan, N Krishna, E-mail: nvr8@rediffmail.com [Department of Physics, Akkineni Nageswara Rao College, Gudivada-521 301, A.P (India)

    2009-07-15

    PbO-Sb{sub 2}O{sub 3}-B{sub 2}O{sub 3} glasses mixed with different concentrations of MnO (ranging from 0 to 3.0 mol %) were crystallized. The samples were characterized by X-ray diffraction, scanning electron microscopy and EDS techniques. A number of studies viz., optical absorption, ESR, IR, magnetic susceptibility and luminescence of these glass ceramics have been carried out. The X-ray diffraction spectra revealed the presence of lead antimony oxide and manganese antimony oxide crystalline phases in these samples. The variations observed as the function of the crystallizing agent in all the properties have been analyzed in the light of different oxidation states (Mn{sup 2+} and Mn{sup 3+}) and environment of manganese ions in the glass ceramic network.

  10. Giant magnetoimpedance effect of Co{sub 68.15} Fe{sub 4.35} Si{sub 12.5} B{sub 15} amorphous wire in the presence of magnetite ferrofluid

    Energy Technology Data Exchange (ETDEWEB)

    Amirabadizadeh, A. [Department of Physics, University of Birjand, P. O. Box 97175-615, Birjand (Iran, Islamic Republic of); Lotfollahi, Z., E-mail: lotfollahi@gmail.com [Department of Physics, University of Birjand, P. O. Box 97175-615, Birjand (Iran, Islamic Republic of); Zelati, A. [Department of Electrical Engineering, Technical Faculty of Ferdows, University of Birjand (Iran, Islamic Republic of)

    2016-10-01

    Giant magnetoimpedance effect (GMI) in Co{sub 68.15} Fe{sub 4.35} Si{sub 12.5} B{sub 15} amorphous wire was studied in the presence of magnetite ferrofluid and without it. Magnetite nanoparticles for ferrofluid were prepared by the traditional wet chemistry co-precipitation method. GMI was measured in the frequency range of 2 to 6 MHz. The maximum value of GMI value of the ferrofluid covered amorphous wire was increased in all frequency intervals in comparison with GMI response of the wire non-covered by ferrofluid. These results open a new way of increasing magnetoimpedance effect value useful for sensor applications. - Highlights: • Amorphous Co-based wires display GMI effect and this feature is of potential interest for developing small magnetic field sensors and biosensors. • This manuscript is dealing with the improvement of the GMI response of an amorphous Co-based wire/magnetite ferrofluid. • The effect of ferrofluid presence in the sensing element is also analyzed. • The results show that GMI maximum increases in a 100% at 4.5 MHz and the sensitivity also does about a 150%. • Amorphous Co-based wires display giant magneto impedance effect (GMI) and this intrinsic feature is of potential interest for developing small magnetic field sensors and biosensors. • This manuscript is dealing with the improvement of the GMI response of an amorphous Co{sub 68.15}Fe{sub 4.35}Si{sub 12.5}B{sub 15} wire/magnetite ferrofluid. • The effect of ferrofluid presence in the sensing element is also analyzed. • The results show that GMI maximum increases in a 100% at 4.5 MHz and the sensitivity also does about a 150%.

  11. D{sub sJ}(2860) from the semileptonic decays of B{sub s} mesons

    Energy Technology Data Exchange (ETDEWEB)

    Gan, Long-Fei; Zhang, Jian-Rong; Huang, Ming-Qiu; Zhuo, Hong-Bin; Ma, Yan-Yun; Zhu, Qing-Jun; Liu, Jian-Xun; Zhang, Guo-Bo [National University of Defense Technology, College of Science, Changsha, Hunan (China)

    2015-05-15

    In the framework of heavy quark effective theory, the leading-order Isgur-Wise form factors relevant to semileptonic decays of the ground state anti bs meson B{sub s} into orbitally excited D-wave anti cs mesons, including the newly observed narrow D{sub s1}{sup *}(2860) and D{sub s3}{sup *}(2860) states by the LHCb Collaboration, are calculated with the QCD sum rule method. With these universal form factors, the decay rates and branching ratios are estimated. We find that the decay widths are Γ(B{sub s} → D{sub s1}{sup *}l anti ν) = 1.25{sub -0.60}{sup +0.80} x 10{sup -19} GeV, Γ(B{sub s} → D{sub s2}{sup '}l anti ν) = 1.49{sub -0.73}{sup +0.97} x 10{sup -19} GeV, Γ(B{sub s} → D{sub s2}l anti ν) = 4.48{sub -0.94}{sup +1.05} x 10{sup -17} GeV, and Γ(B{sub s} → D{sub s3}{sup *}l anti ν) = 1.52{sub -0.31}{sup +0.35} x 10{sup -16} GeV. The corresponding branching ratios are B(B{sub s} → D{sub s1}{sup *}l anti ν) = 2.85{sub -1.36}{sup +1.82} x 10{sup -7}, B(B{sub s} → D{sub s2}{sup '}l anti ν) = 3.40{sub -1.66}{sup +2.21} x 10{sup -7}, B(B{sub s} → D{sub s2}l anti ν) = 1.02{sub -0.21}{sup +0.24} x 10{sup -4}, and B(B{sub s} → D{sub s3}{sup *}l anti ν) = 3.46{sub -0.70}{sup +0.80} x 10{sup -4}. The decay widths and branching ratios of corresponding B{sub s}{sup *} semileptonic processes are also predicted. (orig.)

  12. Crystal structure features in a new compound C{sub 4}B{sub 25}Mg{sub 1.42}

    Energy Technology Data Exchange (ETDEWEB)

    Konovalikhin, S. V., E-mail: ksv17@ism.ac.ru; Ponomarev, V. I. [Russian Academy of Sciences, Institute of Structural Macrokinetics and Materials Science (Russian Federation)

    2015-09-15

    The composition of C{sub 4}B{sub 25}Mg{sub 1.42} crystal obtained by self-propagating high-temperature synthesis was determined using X-ray diffraction. This is the first crystalline structure where all boron atoms in the B{sub 12} icosahedron occupy crystallographically independent positions; this circumstance allowed us to analyze the effect of substituents on bond lengths in the icosahedron. The crystal structure features, including the channels filled with disordered Mg atoms and the spread of B—B endo- and exo-bond lengths in the icosahedra, are described. A crystallochemical analysis of pair bonds has been performed for the first time.

  13. Measurement of CP violation parameters and polarisation fractions in B{sub s}{sup 0}→J / ψ K̄ {sup ∗0} decays

    Energy Technology Data Exchange (ETDEWEB)

    Aaij, R. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Adeva, B. [Universidad de Santiago de Compostela, Santiago de Compostela (Spain); Adinolfi, M. [H.H. Wills Physics Laboratory, University of Bristol, Bristol (United Kingdom); Affolder, A. [Oliver Lodge Laboratory, University of Liverpool, Liverpool (United Kingdom); Collaboration: The LHCb collaboration; and others

    2015-11-12

    The first measurement of C P asymmetries in the decay B{sub s}{sup 0}→J / ψ ( K)-bar  {sup ∗}(892){sup 0} and an updated measurement of its branching fraction and polarisation fractions are presented. The results are obtained using data corresponding to an integrated luminosity of 3.0 fb{sup −1} of proton-proton collisions recorded with the LHCb detector at centre-of-mass energies of 7 and 8 TeV. Together with constraints from B{sup 0}→J / ψ ρ{sup 0}, the results are used to constrain additional contributions due to penguin diagrams in the C P-violating phase ϕ{sub s}, measured through B{sub s}{sup 0} decays to charmonium.

  14. Preparation, characterization and wear resistance to ceramic composites Si C/Ti B{sub 2}; Elaboration, caracterisation et resistance a l`usure de composites ceramiques SiC/TiB{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, C.

    1997-12-18

    The composites Si C-Ti B{sub 2} (5,10,15% vol. Ti B{sub 2}) have been synthesized by natural and reactive sintering from Ti O{sub 2}, B{sub 4} C and phenolic resin used as carbon source, by the reaction: Ti O{sub 2} + 0.5 B{sub 4} C +1.5 C -> Ti B{sub 2} + 2 CO (1400 degrees Celsius). They have been characterized from a microstructural, mechanical and tribological point of view. The dispersion of Ti B{sub 2} particles is very homogeneous in optical microscopy and in scanning electron microscopy. The images analysis has showed that most of the particles have a size smaller than 1 {mu}m. The atomic force microscopy and the transmission electron microscopy have revealed the existence of nanometrical particles. Concerning the mechanical properties, the fracture toughness increases with the Ti B{sub 2} rate and the hardness decreases. By friction, the composite materials wear slowly than the monolithic SiC. The wear mechanisms are modified in air and in water. In air, a layer of oxidized scraps, protector if it is stable, are formed for composites while there is formation of rollers for SiC. In water, composites are polished while SiC wears by cleavages. The influence of the Ti B{sub 2} phase on the wear resistance is due to the tribo-oxidation: a lubrication can take place through the tribo-oxidation products. (O.M.) 64 refs.

  15. Hydrothermal synthesis and thermodynamic properties of 2ZnO . 3B{sub 2}O{sub 3} . 3H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Gao Yihong [Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an 710062 (China); Liu Zhihong [Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an 710062 (China)], E-mail: liuzh@snnu.edu.cn; Wang Xiaolan [Department of Chemistry, Shaanxi Institute of Education, Xi' an 710061 (China)

    2009-06-15

    The important zinc borate of 2ZnO . 3B{sub 2}O{sub 3} . 3H{sub 2}O has been synthesized and characterized by means of chemical analysis, XRD, FT-IR, and DTA-TG techniques. The molar enthalpies of solution of H{sub 3}BO{sub 3}(s) in HCl . 54.561H{sub 2}O, of ZnO(s) in the mixture of HCl . 54.561H{sub 2}O and calculated amount of H{sub 3}BO{sub 3}, and of 2ZnO . 3B{sub 2}O{sub 3} . 3H{sub 2}O(s) in HCl . 54.604H{sub 2}O were measured, respectively. With the use of the standard molar enthalpies of formation for ZnO(s), H{sub 3}BO{sub 3}(s), and H{sub 2}O(l), the standard molar enthalpy of formation of -(5561.7 {+-} 4.9) kJ . mol{sup -1} for 2ZnO . 3B{sub 2}O{sub 3} . 3H{sub 2}O(s) was obtained. Thermodynamic properties of this compound were also calculated by a group contribution method.

  16. Structure of the metastable cubic B{sub 1} phase of the La{sub 2}Mo{sub 2}O{sub 9} single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Alekseeva, O. A., E-mail: olalex@ns.crys.ras.ru; Sorokina, N. I.; Verin, I. A. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Voronkova, V. I.; Krasil' nikova, A. E. [Moscow State University, Faculty of Physics (Russian Federation)

    2009-01-15

    The structure of the metastable B{sub 1} phase of the La{sub 2}Mo{sub 2}O{sub 9} single crystal is investigated using X-ray diffraction. It is established that the crystal structure of the compound under investigation is described by the cubic unit cell with the parameter a = 7.158(5) A, which makes it possible to index approximately 84% of the reflections measured for this single crystal. The structure of the metastable cubic B{sub 1} phase is characterized by a local lowering of the symmetry for the La and Mo atoms, which are displaced from their positions on the threefold axis, thus forming three sites around it with an occupancy of 0.333(2). The O(1) atom in the structure of the metastable cubic B{sub 1} phase remains in the 4a position on the threefold axis but occupies it by only 86%. The O(2) and O(3) atoms located in a general position occupy their own sites with occupancies of 0.77(2) and 0.35(2), respectively. The final R factor of the refinement of this structural model is 2.52%.

  17. Measurement of the B{sub s} oscillations with the semileptonic deacy B{sup 0}{sub s} {yields} D{sup -}{sub s} ({phi}{pi}{sup -}) {mu}{sup +}{nu}{sub {mu}} with the DOe detector; Messung der B{sub s}-Oszillation mit dem semileptonischen Zerfall B{sup 0}{sub s} {yields} D{sup -}{sub s} ({phi}{pi}{sup -}) {mu}{sup +}{nu}{sub {mu}} mit dem DOe-Detektor

    Energy Technology Data Exchange (ETDEWEB)

    Ay, C.

    2006-07-01

    in this thesis the measurement of B{sub s} oscillations by means of the decay B{sub s}{yields}D{sub s}{sup -}({phi}{pi}{sup -}){sub {mu}}{sup +}X at the Tevatron at a c. m. energy of {radical}(s)=1.96 TeV is described. From the results a lower limit of the oscillation frequency of {delta}m{sub s}>15.5 ps{sup -1} has been derived. (HSI)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-05-15

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

  19. Microstructure evolution in the rapidly quenched Fe{sub 78}Si{sub 9}B{sub 13} ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.-M., E-mail: weiminw@sdu.edu.c [Key Lab of Liquid Structure and Heredity of Materials, Shandong University, Jinan 250061 (China); Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Jin, S.F. [Key Lab of Liquid Structure and Heredity of Materials, Shandong University, Jinan 250061 (China); Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China); Zhang, J.T.; Huang, T.; Wang, L.; Bian, X.F. [Key Lab of Liquid Structure and Heredity of Materials, Shandong University, Jinan 250061 (China)

    2009-11-01

    We report microstructure evolution in as-spun Fe{sub 78}Si{sub 9}B{sub 13} ribbons under various wheel speeds (s), which was investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). With decreasing s, the volume fraction of the residual amorphous phase (V{sub a}) in the as-spun ribbons decreases gradually, and the total exothermic heat of the crystallization in the DSC curves also decreases, but the ratio of the exothermic heat of the second crystallization to the first one is on the contrary. alpha-Fe is found in the ribbon with s of 32.9 m/s, while alpha-Fe, eutectic alpha-Fe+Fe{sub 2}B, and Fe{sub 3}Si phases are found in ribbons with s of 25.6 and 18.3 m/s. The phase precipitating behavior in cooling processes is well consistent with the annealing process in the literatures.

  20. Optical spectra of YBa{sub 2}Cu{sub 3}O{sub 7} monocrystalline films on Li{sub 2}B{sub 4}O{sub 7} (001) substrates in the 0.2-6 eV spectral range

    Energy Technology Data Exchange (ETDEWEB)

    Kityk, I.V.; Burak, Ya.V.; Lutsiv, R.V.; Mervinskii, R.I.; Roter, V.E. [Franko Lvov State Univ. (Ukraine)

    1993-12-01

    Studies of YBa{sub 2}Cu{sub 3}O{sub 7} films on Li{sub 2}B{sub 4}O{sub 7} substrates showed that the excitation energy of plasmons related to free carriers is weakly anisotropic in the ab plane. The corresponding splitting (0.16 eV) is far less than that in crystals ({approx_equal}0.58 eV). The splitting of plasmons related to the valence electrons lies within 0.05-0.10 eV. The plasmon energies in films and in crystals are shifted by 0.5 eV. 8 refs., 2 figs.

  1. Model-based analysis of thromboxane B{sub 2} and prostaglandin E{sub 2} as biomarkers in the safety evaluation of naproxen

    Energy Technology Data Exchange (ETDEWEB)

    Sahota, Tarjinder; Sanderson, Ian; Danhof, Meindert [Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden (Netherlands); Della Pasqua, Oscar [Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden (Netherlands); Clinical Pharmacology Modelling and Simulation, GlaxoSmithKline, Uxbridge (United Kingdom)

    2014-08-01

    The assessment of safety in traditional toxicology protocols relies on evidence arising from observed adverse events (AEs) in animals and on establishing their correlation with different measures of drug exposure (e.g., C{sub max} and AUC). Such correlations, however, ignore the role of biomarkers, which can provide further insight into the underlying pharmacological mechanisms. Here we use naproxen as a paradigm drug to explore the feasibility of a biomarker-guided approach for the prediction of AEs in humans. A standard toxicology protocol was set up for the evaluation of effects of naproxen in rat, in which four doses were tested (7.5, 15, 40 and 80 mg/kg). In addition to sparse blood sampling for the assessment of exposure, thromboxane B{sub 2} and prostaglandin E{sub 2} were also collected in satellite groups. Nonlinear mixed effects modelling was used to evaluate the predictive performance of the approach. A one-compartmental model with first order absorption was found to best describe the pharmacokinetics of naproxen. A nonlinear relationship between dose and bioavailability was observed which leads to a less than proportional increase in naproxen concentrations with increasing doses. The pharmacodynamics of TXB{sub 2} and PGE{sub 2} was described by direct inhibition models with maximum pharmacological effects achieved at doses > 7.5 mg/kg. The predicted PKPD relationship in humans was within 10-fold of the values previously published. Moreover, our results indicate that biomarkers can be used to assess interspecies differences in PKPD and extrapolated data from animals to humans. Biomarker sampling should be used systematically in general toxicity studies. - Highlights: • Prediction of a drug's safety profile from preclinical protocols remains challenging. • Pharmacokinetic measures of safe exposure (e.g., AUC) ignore the role of biomarkers. • PKPD relationships enable the evaluation of adverse events in a mechanistic manner. • Major

  2. Structure and crystallization behavior of La{sub 2}O{sub 3}⋅3B{sub 2}O{sub 3} metaborate glasses doped with Nd{sup 3+} or Eu{sup 3+} ions

    Energy Technology Data Exchange (ETDEWEB)

    Pytalev, D.S., E-mail: pytalev@isan.troitsk.ru [Institute of Spectroscopy, Russian Academy of Sciences, 5 Fizicheskaya St., 142190 Troitsk, Moscow (Russian Federation); Caurant, D.; Majérus, O.; Trégouët, H. [Institut de Recherche de Chimie Paris, CNRS – Chimie ParisTech, 11 Rue Pierre et Marie Curie, 75005 Paris (France); Charpentier, T. [CEA, IRAMIS, NIMBE, CEA-CNRS UMR 3299, Laboratoire de Structure et Dynamique par Résonance Magnétique, 91191 Gif-sur-Yvette (France); Mavrin, B.N. [Institute of Spectroscopy, Russian Academy of Sciences, 5 Fizicheskaya St., 142190 Troitsk, Moscow (Russian Federation)

    2015-08-25

    Highlights: • The structure and crystallization behavior of the La{sub 2}O{sub 3}⋅3B{sub 2}O{sub 3} glass are studied. • LaB{sub 3}O{sub 6} crystallizes congruently without intermediate but only from glass surface. • The structure of the amorphous and the crystalline phases differ significantly. • The activation energy of LaB{sub 3}O{sub 6} crystal growth is determined. - Abstract: The local structure and crystallization behavior of the stoichiometric La{sub 2}O{sub 3}⋅3B{sub 2}O{sub 3} (LaMB) metaborate glass doped with Nd{sup 3+} or Eu{sup 3+} ions are studied using differential thermal analysis (DTA), X-ray diffraction (XRD), Raman scattering and {sup 11}B magic-angle spinning nuclear magnetic resonance (MAS NMR), optical absorbance and luminescence techniques. In the crystallized samples, XRD, NMR and Raman spectroscopy have detected the formation of only one crystalline phase (congruent crystallization of LaB{sub 3}O{sub 6}). No intermediate metastable crystalline phase has been detected before LaB{sub 3}O{sub 6} crystals formation (single stage crystallization process). The observation of heat treated glass samples by scanning electron microscopy (SEM) and optical microscopy coupled with the study of the effect of varying the glass particle size on the DTA curves have both revealed that LaB{sub 3}O{sub 6} crystallization only occurs by a heterogeneous nucleation mechanism (needle-shape crystals) from glass surface. The activation energy E{sub c} of crystal growth has been determined by performing DTA experiments at different heating rates with the Kissinger (784 kJ/mol) and Ozawa (801 kJ/mol) equations than can be used for surface crystallization processes. The heterogeneous crystallization behavior and the spectroscopic results obtained in this work by comparing the LaMB glass with the LaB{sub 3}O{sub 6} crystalline phase suggest the existence of significant structural differences between the amorphous and the crystalline phases contrary to what

  3. Diagnosis of SDAT by HMPAO SPECT and vitamin B{sub 12} serum concentration; Diagnostik der SDAT mittels HMPAO-SPECT und Serumvitamin-B{sub 12}-Spiegel

    Energy Technology Data Exchange (ETDEWEB)

    Mikosch, P. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin; Gallowitsch, H.J. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin; Gomez, I. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin; Kresnik, E. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin; Ploeb, H. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin; Lind, P. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin

    1995-06-01

    It is quite difficult to confirm the diagnosis of demential disorders, including senile dementia of the Alzheimer type (SDAT) by clinical means only. Through the combination of {sup 99m}Tc-HMPAO brain SPECT and serum vitamin B{sub 12} determination it was hoped to speed up and improve the diagnosis of SDAT. 116 patients who had been divided into four groups according to their defect pattern in the {sup 99m}Tc-HMPAO brain SPECT 17 very probably had SDAT; of these 15 showed a defect pattern with brain SPECT which could be associated to SDAT. The majority of SDAT patients had serum vitamin B{sub 12} levels in the lower normal range or pathologically below that range. Both investigations contributed to establishing the SDAT diagnosis without replacing other investigations. The determination of serum vitamin B{sub 12} does not require any major additional effort. (orig.) [Deutsch] Die alleinige klinische Abklaerung dementieller Zustandsbilder, so auch der senilen Demenz vom Alzheimertyp (SDAT), ist schwierig. Durch die Kombination von {sup 99m}Tc-HMPAO-Gehirn-SPECT und Serumvitamin-B{sub 12}-Bestimmung erwarteten wir eine Beschleunigung und Verbesserung der Diagnostik der SDAT. Von 116 Patienten, die in 4 Gruppen, entsprechend ihrem {sup 99m}Tc-HMPAO-Verteilungsmuster eingeteilt worden waren, konnten bei 17 klinisch sehr wahrscheinlichen SDAT-Patienten bei 15 Auffaelligkeiten mit Hinweis auf SDAT im Gehirn SPECT gefunden werden. Ein Teil der Patienten wies einen niedrig-normalen bzw. pathologisch niedrigen Vitamin-B{sub 12}-Spiegel auf. Andere Untersuchungen wuerden durch die Kombination von Gehirn-SPECT und Serumvitamin-B{sub 12}-Bestimmung nicht ueberfluessig werden, obwohl beide Untersuchungen Informationen lieferten, die die Zuordnung zur Diagnose SDAT erleichterten. Die zusaetzliche Serumvitamin-B{sub 12}-Bestimmung stellt keinen wesentlichen Mehraufwand dar. (orig.)

  4. Nitrogen versus helium: effects of the choice of the atomizing gas on the structures of Fe{sub 50}Ni{sub 30}Si{sub 10}B{sub 10} and Fe{sub 32}Ni{sub 36}Ta{sub 7}Si{sub 8}B{sub 17} powders

    Energy Technology Data Exchange (ETDEWEB)

    Zambon, A

    2004-07-15

    Gas atomization can produce, besides a possible significant degree of undercooling, high cooling rates, whose extent depends on the size of the droplets, on their velocity with respect to the surrounding medium, on the thermo-physical properties of both the alloy and the gas, and of course on the operating conditions such as melt overheating and gas-to-metal flow ratio. In this respect it is well-known that the atomizing gas can play a significant role in determining both the powder size distribution and the kind and mix of phases which result from the solidification and cooling processes. The microstructures and solidification morphologies of powders obtained from nitrogen and helium sonic gas atomization of two iron-nickel base glass forming alloys, Fe{sub 50}Ni{sub 30}Si{sub 10}B{sub 10} and Fe{sub 32}Ni{sub 36}Ta{sub 7}Si{sub 8}B{sub 17}, were investigated by means of light microscopy, X-ray diffraction (XRD) and differential thermal analysis (DTA). The Fe{sub 32}Ni{sub 36}Ta{sub 7}Si{sub 8}B{sub 17} alloy exhibits a higher proneness to the development of amorphous phase than the Fe{sub 50}Ni{sub 30}Si{sub 10}B{sub 10} alloy, while the effect of the higher speed attainable by the stream of helium with respect to that of nitrogen, affords not only to obtain a larger amount of particles in the finer size ranges, but also to affect the relative amounts of phases within the different size fractions.

  5. Synthesis and optical properties of polycrystalline Li{sub 2}Al{sub 2}B{sub 2}O{sub 7} (LABO)

    Energy Technology Data Exchange (ETDEWEB)

    Dagdale, S. R., E-mail: shiva.dagdale68@gmail.com; Muley, G. G., E-mail: gajananggm@yahoo.co.in [Department of Physics Sant Gadge Baba Amravati University, Amravati, Maharashtra, India-444602 (India)

    2016-05-06

    A polycrystalline lithium aluminum borate (Li{sub 2}Al{sub 2}B{sub 2}O{sub 7}, LABO) has been synthesized by using simple solid-state technique. The obtained LABO polycrystalline was characterized by powder X-ray diffraction; Fourier transform infrared (FT-IR) spectroscopy and second harmonic generation (SHG) efficiency measurement. The functional groups were identified using the FT-IR spectroscopic data. The SHG efficiency of the polycrystalline material was obtained by the classic Kurtz powder technique using a fundamental wavelength 1064 nm of Nd:YAG laser and it is found to be 1.4 times that of potassium dihydrogen phosphate (KDP).

  6. Small angle neutron scattering studies of the flux line lattices in the borocarbide superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Eskildsen, Morten Ring

    1998-12-01

    This thesis describes small angle neutron scattering studies of the flux line lattice (FLL) in the following members of the borocarbide superconductors: YNi{sub 2}B{sub 2}C, ErNi{sub 2}B{sub 2}C, TmNi{sub 2}B{sub 2}C, LuNi{sub 2}B{sub 2}C, Y{sub 0.75}Lu{sub 0.25}Ni{sub 2}B{sub 2}C and Lu(Ni{sub 1-x}CO{sub x}){sub 2}B{sub 2}C with x = 1.5 - 9%. Of the materials ErN{sub 2}B{sub 2}C and TmNi{sub 2}B{sub 2}C exhibits coexisting superconductivity and magnetic ordering. Three main conclusions can be derived from the results in this thesis. Existence of a low field hexagonal to square symmetry transition of the FLL, ubiquitous to the superconducting borocarbides, magnetic and non-magnetic alike. This symmetry transition is due to the four-fold anisotropy of the Fermi surface, distorting the screening currents towards a square flow pattern. This four-fold anisotropy together with non-local electrodynamics induces a transition to a square FLL, as the field is increased. Changing the non-locality range shifts the square to hexagonal transition onset field. A static disordering of the FLL in YNi{sub 2}B{sub 2}C and LuNi{sub 2}B{sub 2}C. In these materials one observes a well ordered FLL, with a longitudinal correlation length exceeding 100 flux line spacings. As the applied field is increased the longitudinal correlation length, increases with field up to H/H{sub c2} {approx} 0.2. Above this field the FLL correlation length slowly starts to fall off, in contradiction to theoretical models. The existence of complex interactions between the magnetic state and the FLL in TmNi{sub 2}B{sub 2}C. This is signalled by coinciding changes in the FLL symmetry and in the magnetic structure. The FLL show a two-step symmetry transition from square to rhombic and then hexagonal with increased field. In addition, the FLL reflectivity shows distinct peaks as the thulium ions orders magnetically at T{sub N} and across the field driven magnetic transition. No explanation for this behaviour

  7. Structural influence of aluminium, gallium and indium metal oxides by means of dielectric and spectroscopic properties of CaO-Sb{sub 2}O{sub 3}-B{sub 2}O{sub 3} glass system

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasa Reddy, M. [Department of Physics, Acharya Nagarjuna University P.G. Centre, Nuzvid 521 201, AP (India); Naga Raju, G. [Department of Physics, Acharya Nagarjuna University P.G. Centre, Nuzvid 521 201, AP (India); Nagarjuna, G. [Department of Chemistry, Acharya Nagarjuna University, Nagarjunanagar, AP (India); Veeraiah, N. [Department of Physics, Acharya Nagarjuna University P.G. Centre, Nuzvid 521 201, AP (India)]. E-mail: nvr8@rediffmail.com

    2007-07-12

    Dielectric constant ({epsilon}'), loss (tan {delta}), ac conductivity ({sigma}) of CaO-Sb{sub 2}O{sub 3}-B{sub 2}O{sub 3}:M{sub 2}O{sub 3} (Al{sub 2}O{sub 3}, Ga{sub 2}O{sub 3} and In{sub 2}O{sub 3}) glasses with varying concentrations of M{sub 2}O{sub 3} (0-5 mol%), were measured as a function of frequency and temperature over moderately wide ranges. The analysis of results of these studies along with IR, Raman and optical absorption spectra and also DTA studies indicated that in the concentration ranges, 0 {<=} Al{sub 2}O{sub 3} {<=} 4, 0 {<=} Ga{sub 2}O{sub 3} {<=} 2 and 1 {<=} In{sub 2}O{sub 3} {<=} 5, Al{sup 3+}, Ga{sup 3+} ions occupy tetrahedral positions whereas In{sup 3+} ions take up octahedral substitutional positions, cross-link with the other structural units in the glass network and increase the rigidity of the glass network.

  8. Effect of irradiation temperature on crystallization of {alpha}-Fe induced by He irradiations in Fe{sub 80}B{sub 20} amorphous alloy

    Energy Technology Data Exchange (ETDEWEB)

    San-noo, Toshimasa; Toriyama, Tamotsu; Wakabayashi, Hidehiko; Iijima, Hiroshi [Musashi Inst. of Tech., Tokyo (Japan); Hayashi, Nobuyuki; Sakamoto, Isao

    1997-03-01

    Since amorphous alloys are generally highly resistant to irradiation and their critical radiation dose is an order of magnitude higher for Fe-B amorphous alloy than Mo-methods, these alloys are expected to become applicable as for fusion reactor materials. The authors investigated {alpha}-Fe crystallization in an amorphous alloy, Fe{sub 80}B{sub 20} using internal conversion electron Moessbauer spectroscopy. The amount of {alpha}-Fe component was found to increase by raising the He-irradiation dose. The target part was modified to enable He ion radiation at a lower temperature (below 400 K) by cooling with Peltier element. Fe{sub 80}B{sub 20} amorphous alloy was cooled to keep the temperature at 300 K and exposed to 40 keV He ion at 1-3 x 10{sup 8} ions/cm{sup 2}. The amount of {alpha}-Fe crystal in each sample was determined. The crystal formation was not observed for He ion radiation below 2 x 10{sup 18} ions/cm{sup 2}, but that at 3 x 10{sup 8} ions/ cm{sup 2} produced a new phase ({delta} +0.40 mm/sec, {Delta} = 0.89 mm/sec). The decrease in the radiation temperature from 430 to 300 K resulted to extremely repress the production of {alpha}-Fe crystal, suggesting that the crystallization induced by He-radiation cascade is highly depending on the radiation temperature. (M.N.)

  9. Crystal electric field splitting of R{sup 3+}-ions in pure and Co- and Cu-doped RNi{sub 2}B{sub 2}C (R=Ho, Er, Tm)

    Energy Technology Data Exchange (ETDEWEB)

    Gasser, U.; Allenspach, P.; Henggeler, W.; Zolliker, M.; Furrer, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    From the crystal-electric-field (CEF) splitting of the R{sup 3+}-ions, the CEF parameters of RNi{sub 2}B{sub 2}C (R=Ho, Er, Tm) were deduced. In order to get information about the influence of the variation of the density of states (DOS) at the Fermi level (E{sub F}), CEF spectroscopy measurements with Co- and Cu-doped ErNi{sub 2}B{sub 2}C-samples were performed. (author) 1 fig., 1 tab., 1 ref.

  10. Effect of interface on magnetic properties of Co{sub 20}Fe{sub 60}B{sub 20} in ion-beam sputtered Si/CoFeB/MgO and Si/MgO/CoFeB bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Raju, M., E-mail: rajuhcu519@gmail.com [Thin Film Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110 016 (India); Chaudhary, Sujeet; Pandya, D.K. [Thin Film Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110 016 (India)

    2013-04-15

    Effect of interface on magnetic properties of Co{sub 20}Fe{sub 60}B{sub 20} in ion-beam sputtered Si/MgO/CoFeB(top) and Si/CoFeB(bottom)/MgO bilayers is reported. The X-ray reflectivity and magneto-optical Kerr effect analysis revealed that, the interface between bottom MgO and top CoFeB is sensitive to the MgO growth process (post-oxidation, ion-assisted and reactive growth) and its process parameters (assist-ion energy). An increase in interface width from 0.17 nm to 0.47 nm correlates to increase in coercivity from 6 Oe to 34 Oe, decrease of in-plane uniaxial magnetic anisotropy (UMA) from 8×10{sup 3} to 5×10{sup 3} J/m{sup 3} and changes in magnetization reversal. In contrast, the CoFeB(bottom)/MgO interface shows different magnetic behavior and no UMA. - Highlights: ► Dependence of the magnetic response of CoFeB on interface with MgO. ► Growth methods studied for MgO are post-oxidation, reactive and ion-assisted growth. ► Significant amount of in-plane magnetic anisotropy observed for CoFeB(top)/MgO. ► Absence of in-plane magnetic anisotropy in MgO/CoFeB(bottom)

  11. Effect of the oxidation in the surface coercive force of nanocrystalline Fe{sub 73.5}Cu{sub 1}Nb{sub 3}Si{sub 13.5}B{sub 9}alloy

    Energy Technology Data Exchange (ETDEWEB)

    Elbaile, Laura [Departamento de Fisica. Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Pierna, Angel R. [Departamento de Ingenieria Quimica y Medio Ambiente. Universidad del Pais Vasco, PO Box 1379, 20080 San Sebastian (Spain); Garcia, Jose A. [Departamento de Fisica. Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain)]. E-mail: joseagd@uniovi.es; Crespo, Rosario D. [Departamento de Fisica. Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Vara, Gemma [Departamento de Ingenieria Quimica y Medio Ambiente. Universidad del Pais Vasco, PO Box 1379, 20080 San Sebastian (Spain); Angeles Cerdeira, M. [Departamento de Fisica. Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Tejedor, Marcos [Departamento de Fisica. Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain)

    2006-09-15

    Influence of electrochemical corrosion on the surface coercive force of Fe{sub 73.5}Cu{sub 1}Nb{sub 3}Si{sub 13.5}B{sub 9}in the amorphous and nanocrystalline states is investigated. The results show that, in both amorphous and nanocrystalline states, when the oxidized layer increases the surface coercivity decreases.

  12. Luminescence properties of B{sub 2}O{sub 3}–GeO{sub 2}–Gd{sub 2}O{sub 3} scintillating glass doped with rare-earth and transition-metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xin-Yuan, E-mail: sxy5306@126.com [Department of Physics, Jinggangshan University, Ji’an 343009 (China); Jiang, Da-Guo; Wang, Wen-Feng; Cao, Chun-Yan; Li, Yu-Nong; Zhen, Guo-Tai [Department of Physics, Jinggangshan University, Ji’an 343009 (China); Wang, Hong; Yang, Xin-Xin; Chen, Hao-Hong; Zhang, Zhi-Jun [Key Laboratory of Transparent Opto-functional Inorganic Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Zhao, Jing-Tai, E-mail: jtzhao@mail.sic.ac.cn [Key Laboratory of Transparent Opto-functional Inorganic Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

    2013-07-11

    Novel B{sub 2}O{sub 3}–GeO{sub 2}–Gd{sub 2}O{sub 3} ternary scintillating glasses doped with 1 mol% rare-earth and transition-metal activators were synthesized by melt-quenching method. Their transmittance, photoluminescence (PL) and X-ray excited luminescence (XEL) spectra were investigated. The results suggest that a high content of Gd{sub 2}O{sub 3} is of significance for designing dense glass with density of 6.0 g/cm{sup 3}. And energy transfer from Gd{sup 3+} to the incorporated activators can be realized in the borogermanate glasses. The emission position and decay time can be efficiently tuned by incorporating various kinds of activators. All results imply the developed borogermanate scintillating glass is potential for scintillating fields. -- Highlights: • Glass-forming region of B{sub 2}O{sub 3}–GeO{sub 2}–Gd{sub 2}O{sub 3} ternary system are determined. • Radioluminescence response from transition-metal doped B{sub 2}O{sub 3}–GeO{sub 2}–Gd{sub 2}O{sub 3} glasses. • Radioluminescence response from rare-earth doped B{sub 2}O{sub 3}–GeO{sub 2}–Gd{sub 2}O{sub 3} glasses. • Emission peak position and decay time can be tuneable by incorporating various activators.

  13. Phase stabilization of magnetite (Fe{sub 3}O{sub 4}) nanoparticles with B{sub 2}O{sub 3} addition: A significant enhancement on the phase transition temperature

    Energy Technology Data Exchange (ETDEWEB)

    Topal, Uğur, E-mail: ugur.topal@tubitak.gov.tr [TUBITAK-UME, National Metrology Institute, PK 54, 41470 Gebze-Kocaeli (Turkey); Aksan, Mehmet Ali [Inonu Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu 44280, Malatya (Turkey)

    2016-05-15

    Magnetite nanoparticles (MNPs) are extensively investigated for biomedical applications, particularly as contrast agents for Magnetic Resonance Imaging and as drug delivery agent and heat mediators for cancer therapy. Tuning the magnetic properties of the magnetite nanoparticles with doping of foreign atoms has a crucial importance for determining the application areas of these materials and so attracts much interests. On the other hand the doping with foreign atoms requires high temperature annealing, and it causes a phase transition to the hematite phase above 400 °C. In this work the phase transition temperature from the magnetite to the hematite phase has been increased by 200 °C, which is the highest enhancement reported in literature. It was achieved by addition of the appropriate amounts of B{sub 2}O{sub 3.} Our experiments indicates that the 5.0 wt% of B{sub 2}O{sub 3} addition stabilizes and keeps the existence of single phase magnetite up to 600 °C. - Highlights: • B{sub 2}O{sub 3} addition to magnetite nanoparticles enhances the superparamagnetism. • The phase transition temperature of magnetite to hematite increases by 200 °C. • B{sub 2}O{sub 3} addition increases the activation energy of magnetite.

  14. Hydrothermal synthesis, characterization, and luminescence of Ca{sub 2}B{sub 2}O{sub 5}:RE (RE = Eu{sup 3+}, Tb{sup 3+}, Dy{sup 3+}) nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Li; Wan, Yingpeng; Li, Yuze; Pu, Yinfu; Huang, Yanlin, E-mail: huang@suda.edu.cn [Soochow University, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science (China); Chen, Cuili; Seo, Hyo Jin, E-mail: hjseo@pknu.ac.kr [Pukyong National University, Department of Physics and Interdisciplinary Program of Biomedical Engineering (Korea, Republic of)

    2016-04-15

    Ca{sub 2}B{sub 2}O{sub 5}:RE (RE = Eu{sup 3+}, Tb{sup 3+}, Dy{sup 3+}) nanofibers were synthesized by the hydrothermal reaction method. The structural refinement was conducted on the base of the X-ray powder diffraction (XRD) measurements. The surface properties of the Ca{sub 2}B{sub 2}O{sub 5}:RE (RE = Eu{sup 3+}, Tb{sup 3+}, Dy{sup 3+}) nanofibers were investigated by the measurements such as the scanning electron microscope (SEM), transmission electron microscope (TEM), and the energy dispersive spectrum (EDS). The nanofiber has a diameter of about 100 nm and a length of several micrometers. The luminescence properties such as photoluminescence excitation (PLE) and emission spectra (PL), decay lifetime, color coordinates, and the absolute internal quantum efficiency (QE) were reported. Ca{sub 2}B{sub 2}O{sub 5}:Eu{sup 3+} nanofibers show the red luminescence with CIE coordinates of (x = 0.41, y = 0.51) and the luminescence lifetime of 0.63 ms. The luminescence of Ca{sub 2}B{sub 2}O{sub 5}:Tb{sup 3+} nanofibers is green color (x = 0.29, y = 0.53) with the lifetime of 2.13 ms. However, Dy{sup 3+}-doped Ca{sub 2}B{sub 2}O{sub 5} nanofibers present a single-phase white-color phosphor with the fluorescence decay of 3.05 ms. Upon near-UV excitation, the absolute quantum efficiency is measured to be 65, 35, and 37 % for Eu{sup 3+}-, Tb{sup 3+}-, Dy{sup 3+}-doped Ca{sub 2}B{sub 2}O{sub 5} nanofibers, respectively. It is suggested that Ca{sub 2}B{sub 2}O{sub 5}:RE (RE = Eu{sup 3+}, Tb{sup 3+}, Dy{sup 3+}) nanofibers could be an efficient phosphor for lighting and display.

  15. Defects spectroscopy by means of the simple trapping model of the Fe{sub 78}Si{sub 9}B{sub 13} alloy; Espectroscopia de defectos mediante el modelo de atrapamiento simple de la aleacion Fe{sub 78}Si{sub 9}B{sub 13}

    Energy Technology Data Exchange (ETDEWEB)

    Lopez M, A.; Cabral P, A.; Garcia S, S.F. [Laboratorio de Fisica Avanzada, Facultad de Ciencias, Universidad Autonoma del Estado de Mexico. El Cerillo Piedras Blancas, 50000 Toluca, Estado de Mexico (Mexico)

    2007-07-01

    In this work it is analyzed quantitatively the results of the positron annihilation in the Fe{sub 78}Si{sub 9}B{sub 13} alloy by means of the simple trapping model. From this analysis its are derived: a reason of positron trapping in the defects (K), the defects concentration (C{sub d}) and the electronic density associated to the defect (n{sub d}); both first parameters, (K, C{sub d}) its increase and n{sub d} diminishes when increasing the alloy temperature. From this analysis it is also inferred that the defect consists of a multi vacancy of between 15 and 20 mono vacancies. (Author)

  16. YRh{sub 2}Ga. A new intergrowth variant of MgNi{sub 2} and CeCo{sub 3}B{sub 2} related slabs

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, Stefan; Rodewald, Ute C.; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie

    2017-09-01

    The gallide YRh{sub 2}Ga was synthesized by melting of the elements in an arc-furnace followed by annealing in a sealed silica tube in an induction furnace. YRh{sub 2}Ga crystallizes with a new structure type: P6{sub 3}/mmc, a=552.2(1), c=3119.5(6) pm, wR=0.0957, 497 F{sup 2} values, and 34 variables. It is the n=1 member of the RE{sub 2+n}T{sub 3+3n}X{sub 1+2n} structure series with Laves phase (MgNi{sub 2} type in the present case) and CaCu{sub 5} (CeCo{sub 3}B{sub 2} type in the present case) related slabs in the Parthe intergrowth concept.

  17. The effect of B{sub 2}O{sub 3} flux on growth NLBCO superconductor by solid state reaction and wet-mixing methods

    Energy Technology Data Exchange (ETDEWEB)

    Suharta, W. G., E-mail: wgsuharta@gmail.com; Wendri, N.; Ratini, N.; Suarbawa, K. N. [Departement of Physics Faculty of Mathematics and Natural Science Udayana University Bali Indonesia (Indonesia)

    2016-03-11

    The synthesis of B{sub 2}O{sub 3} flux substituted NLBCO superconductor NdBa{sub 1.75}La{sub 0.25}Cu{sub 3}O{sub 7-∂} has been done using solid state reaction and wet-mixing methods in order to obtain homogeneous crystals and single phase. From DTA/TGA characteritations showed the synthesis process by wet-mixing requires a lower temperature than the solid state reaction in growing the superconductor NdBa{sub 1.75}La{sub 0.25}Cu{sub 3}O{sub 7-∂}. Therefore, in this research NdBa{sub 1.75}La{sub 0.25}Cu{sub 3}O{sub 7-∂} sample calcinated at 650°C for wet-mixing method and 820°C for solid state reaction methods. The all samples was sintered at 950°C for ten hours. Crystallinity of the sample was confirmed using X-ray techniques and generally obtained sharp peaks that indicates the sample already well crystallized. Search match analyses for diffraction data gave weight fractions of impurity phase of the solid state reaction method higher than wet-mixing method. In this research showed decreasing the price of the lattice parameter about 1% with the addition of B{sub 2}O{sub 3} flux for the both synthesis process and 2% of wet mixing process for all samples. Characterization using scanning electron microscopy (SEM) showed the distribution of crystal zise for wet-mixing method more homogeneous than solid state reaction method, with he grain size of samples is around 150–250 nm. The results of vibrating sample magnetometer (VSM) showed the paramagnetic properties for all samples.

  18. The substitution effect of chromium on the magnetic properties of (Fe{sub 1−x}Cr{sub x}){sub 80}Si{sub 6}B{sub 14} metallic glasses (0.02≤x≤0.14)

    Energy Technology Data Exchange (ETDEWEB)

    Álvarez-Alonso, Pablo [Departamento de Electricidad y Electrónica, Universidad del País Vasco, Barrio Sarriena s/n, 48940 Leioa (Spain); Santos, J.D.; Pérez, María J. [Departamento de Física, Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Sánchez-Valdes, C.F.; Sánchez Llamazares, J.L. [División de Materiales Avanzados, Instituto Potosino de Investigación Científica y Tecnológica A.C., Camino a la presa San José 2055, CP 78216 San Luis Potosí (Mexico); Gorria, Pedro, E-mail: pgorria@uniovi.es [Departamento de Física, EPI, Universidad de Oviedo, 33203 Gijón (Spain)

    2013-12-15

    Magnetization studies were carried out to characterize the magnetic properties of the Iron-rich metallic glasses (Fe{sub 1−x}Cr{sub x}){sub 80}Si{sub 6}B{sub 14} with 0.02≤x≤0.14. The Curie temperature T{sub C} diminishes almost linearly with the increase in the Cr-content from 401 K (x=0.10) to 291 K (x=0.14), while the saturation magnetization M{sub S} at T=5 K also undergoes a linear reduction from 169 Am{sup 2} kg{sup −1} (x=0.02) to 87 Am{sup 2} kg{sup −1} (x=0.14). These results suggest that the system should become paramagnetic for x≈0.22. The magneto-caloric properties of samples with T{sub C} near room temperature, i.e., with x=0.12 and 0.14, were investigated up to a maximum magnetic field change of 8 T. Both ribbons are characterized by a very broad temperature dependence of the magnetic entropy change ΔS{sub M}(T) and moderate peak values of 2.9 Jkg{sup −1} K{sup −1} and 2.6 Jkg{sup −1} K{sup −1}, respectively. - Highlights: • We report on the magnetic properties of (Fe{sub 1−x}Cr{sub x}){sub 80}Si{sub 6}B{sub 14} metallic glasses with 0.02≤x≤0.14. • Curie temperature and saturation magnetization values reduce linearly as the chromium content increases. • The magneto-caloric response up to 8 T has been measured for samples with x=0.12 and 0.14.

  19. A series of novel gallium and indium borates constructed from [B{sub 5}O{sub 8}(OH){sub 2}]{sup 3-} clusters and metal complex linkers

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Lin [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Yang, Guo-Yu, E-mail: ygy@fjirsm.ac.cn [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); MOE Key Laboratory of Cluster Science, School of Chemistry, Beijing Institute of Technology, Beijing 100081 (China)

    2013-02-15

    Four novel gallium and indium borates, [M(en){sub 2}][B{sub 5}O{sub 8}(OH){sub 2}]{center_dot}H{sub 2}O (M=Ga (1), In (2); en=ethylenediamine), [In(dap){sub 2}][B{sub 5}O{sub 8}(OH){sub 2}]{center_dot}H{sub 2}O (3, dap=1,2-diaminopropane), [In(dien)][B{sub 5}O{sub 8}(OH){sub 2}] (4, dien=diethylenetriamine), have been hydrothermally synthesized and characterized by IR spectra, elemental analyses, powder X-ray diffraction, single crystal X-ray diffraction, and thermogravimetric analyses. Compounds 1, 2 and 3 are isostructural and consist of one-dimensional (1-D) chains built up from [B{sub 5}O{sub 8}(OH){sub 2}]{sup 3-} clusters and Ga-/In-complex linkers. The structure of compound 4 features a 1-D chain containing 8-member rings built by [B{sub 5}O{sub 8}(OH){sub 2}]{sup 3-} clusters and {l_brace}In{sub 2}O{sub 4}{r_brace} dimeric cluster linkers which have never observed in the structural chemistry of borates to date. The H-bonding interactions between adjacent chains lead to 3-D supramolecular network structure. - Graphical abstract: Four novel gallium and indium borates with one-dimensional structures built by B{sub 5}O{sub 8}(OH){sub 2}{sup 3+} clusters and metal complex linkers have been successfully synthesized under hydrothermal conditions. Highlights: Black-Right-Pointing-Pointer Four new Ga/In borates have been hydrothermally made. Black-Right-Pointing-Pointer The helical/ribbon-like chains made of B{sub 5}O{sub 8}(OH){sub 2}{sup 3+} clusters and Ga-/In-complex linkers. Black-Right-Pointing-Pointer The chains form novel 3-D supermolecule framework via H-bonds.

  20. Giant magnetoimpedance intrinsic impedance and voltage sensitivity of rapidly solidified Co{sub 66}Fe{sub 2}Cr{sub 4}Si{sub 13}B{sub 15} amorphous wire for highly sensitive sensors applications

    Energy Technology Data Exchange (ETDEWEB)

    Das, Tarun K.; Mandal, Sushil K. [CSIR - National Metallurgical Laboratory, NDE and Magnetic Materials Group, MST Division, Jamshedpur (India); Banerji, Pallab [Indian Institute of Technology, Kharagpur, Materials Science Centre, Kharagpur (India)

    2016-11-15

    We report a systematic study of the influence of wire length, L, dependence of giant magneto-impedance (GMI) sensitivity of Co{sub 66}Fe{sub 2}Cr{sub 4}Si{sub 13}B{sub 15} soft magnetic amorphous wire of diameter ∝ 100 μm developed by in-water quenching technique. The magnetization behaviour (hysteresis loops) of the wire with different length (L = 1, 2, 3, 5, 8 and 10 cm) has been evaluated by fuxmetric induction method. It was observed that the behaviour of the hysteresis loops change drastically with the wire length, being attributed to the existence of a critical length, L{sub C}, found to be around 3 cm. GMI measurements have been taken using automated GMI measurement system and the GMI sensitivities in terms of intrinsic impedance sensitivity (S{sub Ω/Am}{sup -1}) and voltage sensitivity (S{sub V/Am}{sup -1}) of the wire have been evaluated under optimal bias field and excitation current. It was found that the maximum (S{sub Ω/Am}{sup -1}){sub max} ∼ 0.63 Ω/kAm{sup -1}/cm and (S{sub V/Am}{sup -1}){sub max} ∼ 3.10 V/kAm{sup -1}/cm were achieved at a critical length L{sub C} ∝ 3 cm of the wire for an AC current of 5 mA and a frequency of 5 MHz. These findings provide crucial insights for optimization of the geometrical dimensions of magnetic sensing elements and important practical guidance for designing high sensitive GMI sensors. The relevant combinations of magnetic material parameters and operating conditions that optimize the sensitivity are highlighted. (orig.)

  1. Magnetic properties of A{sub k}(A{sub p}B{sub 1-p}){sub 1}B{sub h} superlattices containing alloy disordered interfaces in a spin-1/2 model

    Energy Technology Data Exchange (ETDEWEB)

    Khater, A.; Fresneau, M. [Laboratoire de Physique PEC, Universite du Mans, Le Mans (France); Abou Ghantous, M. [Department of Physics, American University of Beirut, Beirut (Lebanon)

    2002-05-21

    An Ising model is presented for a simple cubic-type structure, to determine the magnetic properties for superlattices of periodic A{sub k}(A{sub p}B{sub 1-p}){sub 1}B{sub h} formula consisting of k layers of spin-1/2 A ions, h layers of spin-1/2 B ions and single layer disordered alloy interfaces between them. The interface layers are characterized by random arrangements of A and B ions so that (A{sub p}B{sub 1-p}){sub 1} is a two-dimensional thermodynamically stable alloy. The magnetic properties studied concern notably the phase diagrams and the sublattice magnetizations of these systems. The model is general and can be used for ferro- or anti-ferromagnetic A-B exchange couplings. In this paper the A-A and B-B exchange couplings are considered ferromagnetic with no loss of generality. An effective field theory is employed to calculate the properties of these systems. We apply the method to various Fe{sub k}(Fe{sub p} Tb{sub 1-p}){sub 1}Tb{sub h} superlattices. The needed exchange constants for the two-dimensional alloy interface are calculated in the framework of this model, and used to calculate these properties for different concentrations 0{<=}p{<=}1, for these superlattices. The architecture and concentration dependence of the magnetic properties is an important feature of this paper, allowing a useful experimental analysis of similar systems. (author)

  2. Structural and magnetic properties of nanocrystalline Nd{sub 4.5}Fe{sub 72}Co{sub 2}Cr{sub 3}Al{sub 1}B{sub 17.5} ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Pampillo, L.G. [Laboratorio de Solidos Amorfos, Departamento de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires, Av. Paseo Colon 850 (C1063ACV), Ciudad de, Buenos Aires (Argentina)]. E-mail: lpampillo@fi.uba.ar; Saccone, F.D. [Laboratorio de Solidos Amorfos, Departamento de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires, Av. Paseo Colon 850 (C1063ACV), Ciudad de, Buenos Aires (Argentina); Sirkin, H.R.M. [Laboratorio de Solidos Amorfos, Departamento de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires, Av. Paseo Colon 850 (C1063ACV), Ciudad de, Buenos Aires (Argentina)

    2007-02-01

    In this work, it was made a study on structural and magnetic properties of nanocrystalline Nd{sub 4.5}Fe{sub 72}Co{sub 2}Cr{sub 3}Al{sub 1}B{sub 17.5} ribbons obtained from crystallisation of amorphous precursors. A complex two-step crystallisation process, was found by differential scanning calorimetry (DSC): a first crystallisation peak at around T=570 deg. C exhibiting the precipitation of {alpha}-Fe and t-Fe{sub 3}B phases and a diffusive stage ending in a second exothermic peak. Also, isothermal annealings of 10 min duration were performed at 605, 635, 650 and 685 deg. C . Hysteresis curves of isothermally annealed samples showed magnetic hardening, with coercive fields above 2 kOe and an optimised M {sub R}/M {sub S} ratio of around 0.6. Except for the highest treatment temperature used in this work, the demagnetizing curves of annealed ribbons exhibited a step near zero field. This fact suggests a low exchange coupling between hard and soft phases, which can be attributed to the grain border phases. Otherwise, Moessbauer effect spectroscopy allowed us to determine that the absence of step in the demagnetizing curve of ribbons annealed at 685 deg. C , may be attributed to the formation of a {alpha}-(Fe, Co) solid solution (with hyperfine parameters B {sub HF}=35.5 T and {delta}=-0.11 mm/s). The formation of this solid solution also explains the diffusive process in the second crystallisation stage observed by DSC experiment.

  3. Up-regulation of nucleotide excision repair in mouse lung and liver following chronic exposure to aflatoxin B{sub 1} and its dependence on p53 genotype

    Energy Technology Data Exchange (ETDEWEB)

    Mulder, Jeanne E. [Pharmacology and Toxicology Graduate Program, Department of Biomedical and Molecular Sciences, Queen' s University Kingston, Ontario K7L 3N6 (Canada); Bondy, Genevieve S.; Mehta, Rekha [Toxicology Research Division, 2202D, Bureau of Chemical Safety, Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, Ontario K1A 0K9 (Canada); Massey, Thomas E., E-mail: masseyt@queensu.ca [Pharmacology and Toxicology Graduate Program, Department of Biomedical and Molecular Sciences, Queen' s University Kingston, Ontario K7L 3N6 (Canada)

    2014-03-01

    Aflatoxin B{sub 1} (AFB{sub 1}) is biotransformed in vivo into an epoxide metabolite that forms DNA adducts that may induce cancer if not repaired. p53 is a tumor suppressor gene implicated in the regulation of global nucleotide excision repair (NER). Male heterozygous p53 knockout (B6.129-Trp53{sup tm1Brd}N5, Taconic) and wild-type mice were exposed to 0, 0.2 or 1.0 ppm AFB{sub 1} for 26 weeks. NER activity was assessed with an in vitro assay, using AFB{sub 1}-epoxide adducted plasmid DNA as a substrate. For wild-type mice, repair of AFB{sub 1}–N7-Gua adducts was 124% and 96% greater in lung extracts from mice exposed to 0.2 ppm and 1.0 ppm AFB{sub 1} respectively, and 224% greater in liver extracts from mice exposed to 0.2 ppm AFB{sub 1} (p < 0.05). In heterozygous p53 knockout mice, repair of AFB{sub 1}–N7-Gua was only 45% greater in lung extracts from mice exposed to 0.2 ppm AFB{sub 1} (p < 0.05), and no effect was observed in lung extracts from mice treated with 1.0 ppm AFB{sub 1} or in liver extracts from mice treated with either AFB{sub 1} concentration. p53 genotype did not affect basal levels of repair. AFB{sub 1} exposure did not alter repair of AFB{sub 1}-derived formamidopyrimidine adducts in lung or liver extracts of either mouse genotype nor did it affect XPA or XPB protein levels. In summary, chronic exposure to AFB{sub 1} increased NER activity in wild-type mice, and this response was diminished in heterozygous p53 knockout mice, indicating that loss of one allele of p53 limits the ability of NER to be up-regulated in response to DNA damage. - Highlights: • Mice are chronically exposed to low doses of the mycotoxin aflatoxin B{sub 1} (AFB{sub 1}). • The effects of AFB{sub 1} and p53 status on nucleotide excision repair are investigated. • AFB{sub 1} increases nucleotide excision repair in wild type mouse lung and liver. • This increase is attenuated in p53 heterozygous mouse lung and liver. • Results portray the role of p53 in

  4. Effects of B{sub 2}O{sub 3} content and sintering temperature on crystallization and microstructure of CBS glass–ceramic coatings

    Energy Technology Data Exchange (ETDEWEB)

    Li, Pengyang [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Wang, Shubin, E-mail: shubinwang@buaa.edu.cn [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials and Engneering, Beihang University, Beijing 100191 (China); Liu, Jianggao; Feng, Mengjie; Yang, Xinwang [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China)

    2015-11-30

    Graphical abstract: (a) TEM photogram of CG3 sintered at 800 °C, crystals are obvious; (b) the XRD patterns of CG3 glass samples sintered at various temperatures; (c) SEM photogram of CG3 sintered at 800 °C; (d) Kissinger, Augis–Bennett and Ozawa kinetics plots of CG3 glass samples. - Highlights: • Combining sol–gel method with direct sintering method to reduce the temperature of coatings formation. • Characterizing CaO–SiO{sub 2}–B{sub 2}O{sub 3} glass–ceramic coatings on porous substrates. • Surface crystallization of CBS glass–ceramic coatings: nucleation and kinetics. • Activation energies for crystal growth in CBS glass–ceramics with different contents of B{sub 2}O{sub 3}. - Abstract: Borosilicate glass–ceramics precursors with varying compositional ratios in the CaO–SiO{sub 2}–B{sub 2}O{sub 3} (CBS) system were synthesized by sol–gel method. The precursors were calcined at 1200 °C for 2 h to form glass powders. The glass–ceramics were prepared by overlaying glass slurries on the substrates before sintering at different temperatures. The as-prepared glasses and glass–ceramics were characterized by differential scanning calorimetry and X-ray diffraction. The crystallization activation energies (E{sub c}) were calculated using the Kissinger method from DSC results. The morphology and crystallization behavior of the glass–ceramics were monitored by scanning electron microscopy. Both glass transition and crystallization temperatures decreased, however, the metastable zone increased. The E{sub c} values of CBS glasses and glass–ceramics were 254.1, 173.2 and 164.4 kJ/mol with increasing B{sub 2}O{sub 3} content, whereas that of the calcined G3 glass was 104.9 kJ/mol. Finally, the coatings were prepared at a low temperature (700 °C). The crystals that grew on the surface of multilayer coatings demonstrated heterogeneous surface nucleation and crystallization after heat-treatment from 700 °C to 850 °C for 4 h.

  5. Syntheses of halogenated polyhedral phosphaboranes: crystal structure of conjuncto-3,3{sup '}-(closo-1,2-P{sub 2}B{sub 4}Br{sub 3}){sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Willi [Institut fuer Chemie, Universitaet Hohenheim, Garbenstrasse 30, 70599, Stuttgart (Germany)

    2017-04-18

    Co-pyrolysis of B{sub 2}Br{sub 4} with PBr{sub 3} at 480 C gave, in addition to the main product closo-1,2-P{sub 2}B{sub 4}Br{sub 4}, conjuncto-3,3{sup '}-(1,2-P{sub 2}B{sub 4}Br{sub 3}){sub 2} (1) and the twelve-vertex closo-1,7-P{sub 2}B{sub 10}Br{sub 10} (2), both in low yields. X-ray structure determination for 1 [triclinic, space-group P1 with a = 7.220(2) Aa, b = 7.232(2) Aa, c = 8.5839(15) Aa, α = 97.213(15) , β = 96.81(2) , γ = 94.07(2) and Z = 1] confirmed that 1 adopts a structure consisting of two symmetrically boron-boron linked distorted octahedra with the bridging boron atoms in the 3,3{sup '}-positions and the phosphorus atoms in the 1,2-positions. The intercluster 2e/2c B-B bond length is 1.61(3) Aa. The shortest boron-boron bond within the cluster framework is 1.68(2) Aa located between the boron atoms antipodal to the phosphorus atoms. The icosahedral phosphaborane 2 was characterized by {sup 11}B-{sup 11}B COSY NMR spectroscopy showing cross peaks indicative for the isomer with the phosphorus atoms in 1,7-positions. Both the X-ray data of 1 and the NMR spectroscopic data of 1 and 2 give further evidence for the influence of an antipodal effect of heteroatoms to cross-cage boron atoms and, vice versa, of an additional shielding of the phosphorus atoms caused by B-Hal substitution at the boron positions trans to phosphorus. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. PrB{sub 7}{sup -}. A praseodymium-doped boron cluster with a Pr{sup II} center coordinated by a doubly aromatic planar η{sup 7}-B{sub 7}{sup 3-} ligand

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Teng-Teng; Jian, Tian; Wang, Lai-Sheng [Department of Chemistry, Brown University, Providence, RI (United States); Li, Wan-Lu; Chen, Xin; Li, Jun [Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing (China)

    2017-06-06

    The structure and bonding of a Pr-doped boron cluster (PrB{sub 7}{sup -}) are investigated using photoelectron spectroscopy and quantum chemistry. The adiabatic electron detachment energy of PrB{sub 7}{sup -} is found to be low [1.47(8) eV]. A large energy gap is observed between the first and second detachment features, indicating a highly stable neutral PrB{sub 7}. Global minimum searches and comparison between experiment and theory show that PrB{sub 7}{sup -} has a half-sandwich structure with C{sub 6v} symmetry. Chemical bonding analyses show that PrB{sub 7}{sup -} can be viewed as a Pr{sup II}[η{sup 7}-B{sub 7}{sup 3-}] complex with three unpaired electrons, corresponding to a Pr (4f{sup 2}6s{sup 1}) open-shell configuration. Upon detachment of the 6s electron, the neutral PrB{sub 7} cluster is a highly stable Pr{sup III}[η{sup 7}-B{sub 7}{sup 3-}] complex with Pr in its favorite +3 oxidation state. The B{sub 7}{sup 3-} ligand is found to be highly stable and doubly aromatic with six delocalized π and six delocalized σ electrons and should exist for a series of lanthanide M{sup III}[η{sup 7}-B{sub 7}{sup 3-}] complexes. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Structure and physical properties of Cr{sub 5}B{sub 3}-type Ta{sub 5}Si{sub 3} and Ta{sub 5}Ge{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Fang; Forbes, Scott [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada); Ramachandran, Krishna Kumar [Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2 (Canada); Mozharivskyj, Yurij, E-mail: mozhar@mcmaster.ca [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada)

    2015-11-25

    The Cr{sub 5}B{sub 3}-type Ta{sub 5}Si{sub 3} phase was prepared by arc-melting, while the Cr{sub 5}B{sub 3}-type Ta{sub 5}Ge{sub 3} one was synthesized through sintering at 1000 °C. X-ray single crystal diffraction was employed to elucidate their structure. According to the magnetization measurements, both Ta{sub 5}Si{sub 3} and Ta{sub 5}Ge{sub 3} are Pauli paramagnets, with Ta{sub 5}Ge{sub 3} showing a Curie-Weiss-like paramagnetic behavior at low temperatures likely due to presence of paramagnetic impurity. Both Ta{sub 5}Si{sub 3} and Ta{sub 5}Ge{sub 3} display a very low electrical resistivity from 2 to 300 K. The resistivity is constant below 20 K, but displays a positive temperature coefficient above 20 K. Electronic structure calculations with the TB-LMTO-ASA method support the metallic character of the two phases and suggest that the bonding is optimized in both phases. - Highlights: • Synthesis of Cr{sub 5}B{sub 3}-type Ta{sub 5}Si{sub 3} and Ta{sub 5}Ge{sub 3} phases with high purity by arc-melting and sintering, respectively. • Magnetization data and electrical resistivity of the Cr{sub 5}B{sub 3}-type Ta{sub 5}Si{sub 3} and Ta{sub 5}Ge{sub 3} phases. • Crystal and electronic structure analysis for Ta{sub 5}Si{sub 3} and Ta{sub 5}Ge{sub 3} phase by X-ray diffraction and TB-LMTO-ASA calculations.

  8. Effect of Y addition on crystallization behavior and soft-magnetic properties of Fe{sub 78}Si{sub 9}B{sub 13} ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Zhanwei, Liu; Dunbo, Yu, E-mail: yudb2008@126.com; Kuoshe, Li; Yang, Luo; Chao, Yuan; Zilong, Wang; Liang, Sun; Kuo, Men

    2017-08-15

    Highlights: • Thermal stability of Fe-Si-B amorphous alloy is enhanced by Y addition. • Y addition can improve soft magnetic properties of Fe-Si-B amorphous alloy. • Decomposition of metastable Fe{sub 3}B phase is related to Y content in Fe-Si-B matrix. - Abstract: A series of amorphous Fe-Si-B ribbons with various Y addition were prepared by melt-spinning. The effect of Y addition on crystallization behavior, thermal and magnetic properties was systematically investigated. With the increase of Y content, the initial crystallization temperature shifted to a higher temperature, indicating that the thermal stability of amorphous state in Fe-Si-B-Y ribbon is enhanced compared to that of Fe-Si-B alloy. Meanwhile, compared to the two exothermic peaks in the samples with lower Y content, a new exothermic peak was found in the ribbons with Y content higher than 1 at%, which corresponded to the decomposition of metastable Fe{sub 3}B phase. Among all the alloys, Fe{sub 76.5}Si{sub 9}B{sub 13}Y{sub 1.5} alloy exhibits optimized magnetic properties, with high saturation magnetization M{sub s} of 187 emu/g and low coercivity H{sub cJ} of 7.6 A/m.

  9. Multi-jump magnetic switching in ion-beam sputtered amorphous Co{sub 20}Fe{sub 60}B{sub 20} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Raju, M.; Chaudhary, Sujeet; Pandya, D. K. [Thin Film Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India)

    2013-08-07

    Unconventional multi-jump magnetization reversal and significant in-plane uniaxial magnetic anisotropy (UMA) in the ion-beam sputtered amorphous Co{sub 20}Fe{sub 60}B{sub 20}(5–75 nm) thin films grown on Si/amorphous SiO{sub 2} are reported. While such multi-jump behavior is observed in CoFeB(10 nm) film when the magnetic field is applied at 10°–20° away from the easy-axis, the same is observed in CoFeB(12.5 nm) film when the magnetic field is 45°–55° away from easy-axis. Unlike the previous reports of multi-jump switching in epitaxial films, their observance in the present case of amorphous CoFeB is remarkable. This multi-jump switching is found to disappear when the films are crystallized by annealing at 420 °C. The deposition geometry and the energy of the sputtered species appear to intrinsically induce a kind of bond orientation anisotropy in the films, which leads to the UMA in the as-grown amorphous CoFeB films. Exploitation of such multi-jump switching in amorphous CoFeB thin films could be of technological significance because of their applications in spintronic devices.

  10. Analysis of the semileptonic B{sub c} → D{sub 1}{sup 0} transition in QCD sum rules and HQET

    Energy Technology Data Exchange (ETDEWEB)

    Khosravi, R. [Isfahan University of Technology, Department of Physics, Isfahan (Iran, Islamic Republic of)

    2015-04-01

    We investigate the structure of the D{sub 1}{sup 0}(2420 [2430])(J{sup P} = 1{sup +}) mesons via analyzing the semileptonic B{sub c} → D{sub 1}{sup 0}lν transition in the frame work of the three-point QCD sum rules and the heavy-quark effective theory. We consider the D{sub 1}{sup 0} meson in three ways: as a pure vertical stroke c anti u right angle state, as a mixture of the two vertical stroke {sup 3}P{sub 1} right angle and vertical stroke {sup 1}P{sub 1} right angle states with a mixing angle θ, and as a combination of the two mentioned states with mixing angle θ = 35.3 {sup circle} in the heavy-quark limit. Taking into account the gluon condensate contributions, the relevant form factors are obtained for the three above conditions. These form factors are numerically calculated for vertical stroke c anti u right angle and the heavy-quark limit cases. The obtained results for the form factors are used to evaluate the decay rates and the branching ratios. Also for mixed states, all of the mentioned physical quantities are plotted with respect to the unknown mixing angle θ. (orig.)

  11. Electrochemical reduction of 2,4-dinitrophenol on nanocomposite electrodes modified with mesoporous silica and poly(vitamin B{sub 1}) films

    Energy Technology Data Exchange (ETDEWEB)

    Yang Ping; Cai Hui; Liu Shantang [School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430073 (China); Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan 430073 (China); Hubei Key Lab of Novel Reactor and Green Chemical Technology, Wuhan 430073 (China); Wan Qijin, E-mail: qijinwan@mail.wit.edu.cn [School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430073 (China); Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan 430073 (China); Hubei Key Lab of Novel Reactor and Green Chemical Technology, Wuhan 430073 (China); Wang Xiaoxia [Blumenstrasse 6, Gundelfingen 79194 (Germany); Yang Nianjun, E-mail: nianjun.yang@iaf.fraunhofer.de [Fraunhofer-Institute for Applied Solid State Physics (IAF), Freiburg 79108 (Germany)

    2011-08-01

    Electrochemical reduction of 2,4-dinitrophenol was investigated on a glassy carbon electrode modified with a nanocomposite Santa Barbara Amorphous silica (SBA-15) film and poly(vitamin B{sub 1}) film. For sensitive and selective detections, vanadium pentoxide and cerium oxide nanoparticles were incorporated into the matrix of SBA-15. 2,4-Dinitrophenol was reduced on the modified electrode at -0.39 and -0.25 V, corresponding to the reduction of 4-dinitrophenol and 2-dinitrophenol, respectively. Both cathodic peak currents were controlled by the diffusion of 2,4-dinitrophenol. The amplitude of the peak currents was proportional to the 2,4-dinitrophenol concentration in the range of 3.0-30 {mu}M. The modified electrode demonstrated a long lifetime for the detection of 2,4-dinitrophenol. The detection limit of 2,4-dinitrophenol was 0.5 {mu}M. Moreover, the modified electrode was used successfully to detect 2,4-dinitrophenol in lake water.

  12. New analysis of the {delta}I equal to 1/2 rule in Kaon decays and the B{sub K} parameter.

    Energy Technology Data Exchange (ETDEWEB)

    Hambye, T [Istituto Nazionale di Fisica Nucleare, Frascati, RM (Italy). Laboratori Nazionali di Frascati; Koehler, G.O.; Soldan, P.H. [Dortmund Univ., Dortmund (Germany). Inst. fuer Phisik

    1999-07-01

    It is used the 1/N{sub c} expansion within the effective chiral lagrangian for pseudoscalar mesons and compute the hadronic matrix elements at leading and next-to-leading order in the chiral and the 1/N{sub c} expansions. Numerically, our calculation reproduces the dominant {delta}I = 1/2 K{yields} {pi}{pi} amplitude. The result depends only moderately on the choice of the cutoff scale in the chiral loops. The {delta}I = 3/2 amplitude emerges sufficiently suppressed but shows a significant dependence on the cutoff. The B{sub K} parameter turns out to be smaller than the value previously obtained in the 1/N{sub c} approach. It also shows a significant dependence on the choice of the cutoff scale. The results indicate that corrections from higher order terms and/or higher resonances are large for the {delta}I = 3/2 K {yields} {pi}{pi} amplitude and the (|{delta}S| = 2) K{sup 0} - K{sup 0} transition amplitude.

  13. Study of boron carbide evolution under neutron irradiation; Contribution a l'etude de l'evolution du carbure de bore sous irradiation neutronique

    Energy Technology Data Exchange (ETDEWEB)

    Simeone, D. [CEA/Saclay, Dept. de Mecanique et de Technologie (DMT), 91 - Gif-sur-Yvette (France)]|[Universite Blaise Pascal, Clermont-Ferrand II, (CNRS), 63 - Aubiere (France)

    1999-07-01

    Owing to its high neutron efficiency, boron carbide (B{sub 4}C) is used as a neutron absorber in control rods of nuclear plants. Its behaviour under irradiation has been extensively studied for many years. It now seems clear that brittleness of the material induced by the {sup 10}B(n,{alpha}){sup 7}Li capture reaction is due to penny shaped helium bubbles associated to a high strain field around them. However, no model explains the behaviour of the material under neutron irradiation. In order to build such a model, this work uses different techniques: nuclear microprobe X-ray diffraction profile analysis and Raman and Nuclear Magnetic Resonance Spectroscopy to present an evolution model of B{sub 4}C under neutron irradiation. The use of nuclear reactions produced by a nuclear microprobe such as the {sup 7}Li(p,p'{gamma}){sup 7}Li reaction, allows to measure lithium profile in B{sub 4}C pellets irradiated either in Pressurised Water Reactors or in Fast Breeder Reactors. Examining such profiles enables us to describe the migration of lithium atoms out of B{sub 4}C materials under neutron irradiation. The analysis of X-ray diffraction profiles of irradiated B{sub 4}C samples allows us to quantify the concentrations of helium bubbles as well as the strain fields around such bubbles.Furthermore Raman spectroscopy studies of different B{sub 4}C samples lead us to propose that under neutron irradiation. the CBC linear chain disappears. Such a vanishing of this CBC chain. validated by NMR analysis, may explain the penny shaped of helium bubbles inside irradiated B{sub 4}C. (author)

  14. In silico characterization of nitric oxide adsorption on a magnetic [B{sub 24}N{sub 36} fullerene/(TiO{sub 2}){sub 2}]{sup −} nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Anota, E. Chigo, E-mail: ernesto.chigo@correo.buap.mx [Benemérita Universidad Autónoma de Puebla, Facultad de Ingeniería Química, Ciudad Universitaria, San Manuel, Puebla, Código Postal 72570 (Mexico); Arriagada, D. Cortes [Laboratorio de Química Teórica Computacional (QTC), Pontificia Universidad Católica de Chile, Santiago, Av. Vicuña Mackenna 4860, Macul, Santiago 9900087 (Chile); Hernández, A. Bautista [Benemérita Universidad Autónoma de Puebla, Facultad de Ingeniería, Apdo. Postal J-39, Puebla, Pue., 72570 (Mexico); Castro, M., E-mail: miguel.castro.m@gmail.com [Universidad Nacional Autónoma de México-Departamento de Física y Química Teórica, DEPg-Facultad de Química, México D.F., C.P. 04510 (Mexico)

    2017-04-01

    Highlights: • Magnetic properties emerges in homonuclear nitrogen bonding [BN]{sup −} fullerene ions. • Adsorption of nitric oxide on magnetic [BNF/(TiO{sub 2}){sub 2}]{sup −} composites using DFT methods. • The stability of the BN fullerene-NO interaction is enhanced by homo-nuclear N bonds. • The nature of the [B{sub 24}N{sub 36}F/TiO{sub 2}]{sup −}-NO interaction, relatively strong and magnetic, may provide protection to the NO molecule. - Abstract: The (TiO{sub 2}){sub 2}{sup −} cluster supported on an magnetic boron nitride [BN]{sup −} fullerene, re-forced with homonuclear nitrogen bonding, fullerene [BNF]{sup −} was studied using density functional theory. Mainly, adsorption of the nitric oxide, NO, molecule on the [BNF/(TiO{sub 2}){sub 2}]{sup −} nanocomposite was studied. Calculations were done by means of the functional developed by Heyd-Scuseria-Ernzerhof, within the generalized gradient approximation. Quantum simulation results reveal chemical type adsorption for the (TiO{sub 2}){sub 2} anion, which is favorably done on an hexagonal face, of 5N1B composition, of the BNF surface, appearing Ti−N and O−B bonding. The [BNF/(TiO{sub 2}){sub 2}]{sup −} nanocomposite is characterized by magnetic semiconductor behavior: the HOMO–LUMO gap is of 0.93 eV and it presents 1.0 magneton bohr, being similar to those of the pristine BNF and (TiO{sub 2}){sub 2} species. Low-reactivity, high polarity and low work function are attributes of this system. Chemisorption occurs for the interaction of NO with [BNF/(TiO{sub 2}){sub 2}]{sup −}, carried out through the (TiO{sub 2}){sub 2} supported cluster. The increase of the polarity for the three BNF/(TiO{sub 2}){sub 2}-NO, BNF/(TiO{sub 2}){sub 2} and BNF systems, suggest improvement in their dispersion as well an in their solubility in aqueous mediums. Moreover, BNF/(TiO{sub 2}){sub 2}-NO presents a reduction of reactivity, as referred to that of pristine fullerene. Functionalization of fullerene

  15. Determination of the CP violating phase {gamma} by a sum over common decay modes to B{sub s} and antiB{sub s}

    Energy Technology Data Exchange (ETDEWEB)

    Aleksan, R. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee; Le Yaouanc, A.; Oliver, L.; Pene, O.; Raynal, J.C. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique Theorique et Hautes Energies

    1994-06-01

    To help in the difficult determination of the angle {gamma} of the unitarity triangle, Aleksan, Dunietz and Kayser have proposed the modes of the type K{sup -}D{sub s}{sup +}, common to B{sub s} and antiB{sub s}. It is pointed out here that it is possible to gain in statistics by a sum over all modes with ground state mesons in the final state. The delicate point is the relative phase of these different contributions to the dilution factor D of the time-dependent asymmetry. Each contribution to D is proportional to a product F{sup cb} F{sup ub} f{sub D{sub s}} f{sub K} where F denotes form factors and f decay constants. Within a definite phase convention, lattice calculations do not show any change in sign when extrapolating to light quarks the form factors and decay constants. Then, one can show that all modes contribute constructively to the dilution factor, except the P-wave K{sup *-}D{sub s}{sup *+}, which is small. Quark model arguments based on wave function overlaps also confirm this stability in sign. By summing over all these modes, a gain of a factor 6 in statistics relatively to K{sup -}D{sub s}{sup +}, is found. The dilution factor for the sum D{sub tot} is remarkably stable for theoretical schemes that are not in very strong conflict with data on B {yields} {psi}K(K{sup *}) or extrapolated from semileptonic charm form factors, giving D{sub tot} {approx_equal} 0.6, always close to D(K{sup -}D{sub s}{sup +}). (authors). 3 figs., 4 tabs., 21 refs.

  16. First-principles study of structural stability, electronic, optical and elastic properties of binary intermetallic: PtZr

    Energy Technology Data Exchange (ETDEWEB)

    Pagare, Gitanjali, E-mail: gita-pagare@yahoo.co.in [Department of Physics, Sarojini Naidu Government Girls P. G. Autonomous College, Bhopal-462016 (India); Jain, Ekta, E-mail: jainekta05@gmail.com [Department of Physics, Government M. L. B. Girls P. G. Autonomous College, Bhopal-462002 (India); Sanyal, S. P., E-mail: sps.physicsbu@gmail.com [Department of Physics, Barkatullah University, Bhopal-462026 (India)

    2016-05-06

    Structural, electronic, optical and elastic properties of PtZr have been studied using the full-potential linearized augmented plane wave (FP-LAPW) method within density functional theory (DFT). The energy against volume and enthalpy vs. pressure variation in three different structures i.e. B{sub 1}, B{sub 2} and B{sub 3} for PtZr has been presented. The equilibrium lattice parameter, bulk modulus and its pressure derivative have been obtained using optimization method for all the three phases. Furthermore, electronic structure was discussed to reveal the metallic character of the present compound. The linear optical properties are also studied under zero pressure for the first time. Results on elastic properties are obtained using generalized gradient approximation (GGA) for exchange correlation potentials. Ductile nature of PtZr compound is predicted in accordance with Pugh’s criteria.

  17. Order-disorder transition of vortex matter in Mg{sub 0.9}B{sub 2}: anisotropic effects

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, A A M; Ortiz, W A [Grupo de Supercondutividade e Magnetismo, Departamento de Fisica, Universidade Federal de Sao Carlos, SP (Brazil); Sharma, P A; Hur, N; Cheong, S-W, E-mail: ana@df.ufscar.b, E-mail: ana@df.ufscar.b [Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers, NJ (United States)

    2009-03-01

    Third-harmonic susceptibility studies have been employed to probe the order-disorder transition of Vortex Matter of a magnesium-deficient sample of MgB{sub 2}. Our results reveal that the measured threshold is anisotropic for different orientations of the applied magnetic field, suggesting that the pinning efficiency of the magnesium-deficient regions depend on the orientation of the penetrated vortices.

  18. Microstrucural characterization of gas atomized Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} and Fe{sub 97}Si{sub 3} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Escorial, A., E-mail: age@cenim.csic.es [CENIM-CSIC, Avda. Gregorio del Amo, 8, 28040 Madrid (Spain); Lieblich, M. [CENIM-CSIC, Avda. Gregorio del Amo, 8, 28040 Madrid (Spain); Lopez, M.; Marin, P. [Instituto de Magnetismo Aplicado, P.O. Box 155, 28230 Madrid (Spain)

    2011-06-15

    Research highlights: > Two FeSi-base alloys as precursors for small dimension soft magnets. > Small particles rapidly solidified by gas atomisation. > Increase effective magnetic anisotropy constant by alloying segregation. > Magnetic hardenning due to volume decrease. - Abstract: Powder particles of Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} and Fe{sub 97}Si{sub 3} soft magnetic alloys have been prepared by gas atomization. The gas atomized powder was microstructurally characterized and the dependence of coercivity with the composition and powder particle size investigated. As-atomized powder particles of both compositions were constituted by a bcc {alpha}-Fe (Si) solid solution. The Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} powder particles presented a grain microstructure with dendrite structure, which dendrite arms were enriched in Nb. The coercivity increased as the particle size decreased, with a minimum coercivity, of 5 Oe, measured in the Fe{sub 97}Si{sub 3} alloy in the range of 50-100 {mu}m powder particle size. The coercive fields were quite higher in the Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} than in the Fe{sub 97}Si{sub 3} powder, due to the Nb addition, which produced a phase segregation that leads to a noticeable magnetic hardening.

  19. Thickness dependence of magnetic properties and giant magneto-impedance effect in amorphous Co{sub 73}Si{sub 12}B{sub 15} thin films prepared by Dual-Ion beam assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); BISSE/BUAA-SPNEE joint Laboratory Magnetism and Sperconducting technology on Spacecraft, Beihang University, Beijing 100191 (China); Wang, San-sheng, E-mail: wangssh@buaa.edu.cn [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); BISSE/BUAA-SPNEE joint Laboratory Magnetism and Sperconducting technology on Spacecraft, Beihang University, Beijing 100191 (China); Hu, Teng [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); He, Tong-fu [School of Instrumentation Science and Opto-electronics Engineering, Beihang University, Beijing 100191 (China); Chen, Zi-yu [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Yi, Zhong; Meng, Li-Fei [Science and Technology on Reliability and Environmental Engineering Laboratory, Beijing Institute of Spacecraft Environment Engineering, Beijing 100094 (China); BISSE/BUAA-SPNEE joint Laboratory Magnetism and Sperconducting technology on Spacecraft, Beihang University, Beijing 100191 (China)

    2017-03-15

    Dual-Ion Beam Assisted Deposition is a suitable method for the preparation of giant magneto-impedance (GMI) materials. In this paper, Co{sub 73}Si{sub 12}B{sub 15} thin films with different thicknesses were prepared by Dual-Ion Beam Assisted Deposition, and the influences of film thickness on magnetic properties and GMI effect were investigated. It was found that the asymmetric magnetic hysteresis loop in the prepared Co{sub 73}Si{sub 12}B{sub 15} thin films occurs at ambient temperature, and the shift behavior of hysteresis loop associated with film thickness. With the film thickness increasing, the values of shift field and coercive field and other parameters such as remanence and shift ratio appeared complex variation. At a certain frequency, the large GMI effect is only observed in some films, which have good magnetic properties including low coercivity, low remanence ratio and high shift ratio. The results indicated that the thickness dependence of magnetic properties nonlinearly determined the GMI effect in Co{sub 73}Si{sub 12}B{sub 15} thin films. - Highlights: • The relationship between film thickness and ΔZ/Z, ΔR/R, ΔX/X ratio of CoSiB film exhibits a complex behavior as the film thickness increases from 1.33 to 7.34 µm. The maximum value of GMI ratio is observed when the film thickness was 1.56, 2.48, 3.81 or 7.34 µm. • With the increase of film thickness, the peak frequency shifts to lower frequency, but does not decrease following the t-power law. • The above thickness phenomenon is due to the different magnetic properties of thin films. • The Dual-Ion Beam Assisted Deposition is introduced to prepare the GMI materials.

  20. Hydrothermal synthesis and structural analysis of new mixed oxyanion borates: Ba{sub 11}B{sub 26}O{sub 44}(PO{sub 4}){sub 2}(OH){sub 6}, Li{sub 9}BaB{sub 15}O{sub 27}(CO{sub 3}) and Ba{sub 3}Si{sub 2}B{sub 6}O{sub 16}

    Energy Technology Data Exchange (ETDEWEB)

    Heyward, Carla, E-mail: cheywar@clemson.edu; McMillen, Colin D., E-mail: cmcmill@clemson.edu; Kolis, Joseph, E-mail: kjoseph@clemson.edu

    2013-07-15

    Several new borate compounds, Ba{sub 11}B{sub 26}O{sub 44}(PO{sub 4}){sub 2}(OH){sub 6} (1), Li{sub 9}BaB{sub 15}O{sub 27}(CO{sub 3}) (2), and Ba{sub 3}Si{sub 2}B{sub 6}O{sub 16} (3) were synthesized containing other hetero-oxyanion building blocks in addition to the borate frameworks. They were all prepared under hydrothermal conditions and characterized by single crystal and powder X-ray diffraction, and IR spectroscopy. Crystal data: For 1; space group P2{sub 1}/c, a=6.8909 (14) Å, b=13.629 (3) Å, c=25.851 (5) Å, β=90.04 (3)°; For 2; space group P-31c, a=8.8599 (13) Å, c=15.148 (3) Å; For 3; space group P-1, a=5.0414 (10) Å, b=7.5602 (15) Å, c=8.5374 (17) Å, α=77.15 (3)°, β=77.84 (3)°, γ=87.41 (3)° for 3. Compounds 1 and 2 contain isolated oxyanions [PO{sub 4}]{sup 3−} and [CO{sub 3}]{sup 2−} respectively, sitting in channels created by the borate framework, while structure 3 has the [SiO{sub 4}]{sup 4−} groups directly bonded to the borate groups creating a B–O–Si framework. - Highlights: • Hydrothermal syntheses of three new mixed oxyanion borates are presented. • Ba{sub 11}B{sub 26}O{sub 44}(PO{sub 4}){sub 2}(OH){sub 6} contains isolated [PO{sub 4}]{sup 3−} in voids of the borate framework. • Li{sub 9}BaB{sub 15}O{sub 27}(CO{sub 3}) contains isolated [CO{sub 3}]{sup 2−} in channels created by the framework. • Ba{sub 3}Si{sub 2}B{sub 6}O{sub 16} has direct bonding of [SiO{sub 4}]{sup 4−} and borates creating a B–O–Si framework.

  1. Magnetic power losses in [(Fe{sub 1-x}Co{sub x}){sub 75}B{sub 20}Si{sub 5}]{sub 93}Nb{sub 4}Y{sub 3} (x = 0, 0.2, 0.4) bulk metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Piccin, R; Baricco, M [Dipartimento di Chimica IFM and NIS, Universita di Torino, Via P.Giuria 9, 10125 Torino (Italy); Tiberto, P [Istituto Nazionale di Ricerca Metrologica INRIM, Strada delle Cacce 91, 10135 Torino (Italy); Chiriac, H, E-mail: rafael.piccin@unito.i [National Institute of Research and Development for Technical Physics, 47 Mangeron Blvd, Iasi 700050 (Romania)

    2009-01-01

    Magnetic power losses of [(Fe{sub 1-x}Co{sub x}){sub 75}B{sub 20}Si{sub 5}]{sub 93}Nb{sub 4}Y{sub 3} (x = 0, 0.2, 0.4) metallic glasses have been investigated. Bulk samples were prepared by water-cooled Cu-mold injection casting technique with shapes of cylinders (0.8 mm diameter and 30 mm length) and toroids (10 mm external diameter and 0.5 mm thickness). Ribbons prepared by the melt- spinning technique were also analyzed. Glassy structures were confirmed by the presence of a main halo in XRD and by crystallization signal in DSC. Power losses were studied with a digital wattmeter over a range of frequencies from 1 to 400 Hz at selected peak inductions. Ribbons show smaller losses than bulk samples, presenting 24.5 J/m{sup 3} at 50 Hz and 0.65 T peak induction. It was observed that the Co addition reduces significantly the power losses. A separation theory was applied in order to explain the square root behavior of the measured power losses as a function of frequency and the results are in good agreement with the experimental data. The magnetic data were used to identify the presence of crystalline inclusions in the magnetic bulk metallic glasses. The effect of sample shape and composition on magnetic properties will be discussed.

  2. Study of the effects of metalloid elements (P, C, B) on Fe-based amorphous alloys by ab initio molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wenbiao; Li, Qiang, E-mail: qli@xju.edu.cn, E-mail: dhm@xju.edu.cn; Duan, Haiming, E-mail: qli@xju.edu.cn, E-mail: dhm@xju.edu.cn [School of Physics Science and Technology, Xinjiang University, Urumqi, Xinjiang 830046 (China)

    2015-03-14

    In order to understand the effects of the metalloid elements M (M: P, C, B) on the atomic structure, glass formation ability (GFA) and magnetic properties of Fe-based amorphous alloys, Fe{sub 80}P{sub 13}C{sub 7}, Fe{sub 80}P{sub 14}B{sub 6} and Fe{sub 80}B{sub 14}C{sub 6} amorphous alloys are chosen to study through first-principle simulations in the present work. The atomic structure characteristic of the three amorphous alloys is investigated through the pair distribution functions (PDFs) and Voronoi Polyhedra (VPs) analyses. The PDFs and VPs analyses suggest that the GFA of the three alloys dropped in the order of Fe{sub 80}P{sub 13}C{sub 7}, Fe{sub 80}P{sub 14}B{sub 6}, and Fe{sub 80}B{sub 14}C{sub 6}, which is well consistent with the experimental results. The density of state (DOS) of the three amorphous alloys is calculated to investigate their magnetic properties. Based on the DOS analysis, the average magnetic moment of Fe atom in Fe{sub 80}P{sub 13}C{sub 7} and Fe{sub 80}P{sub 14}B{sub 6} amorphous alloys can be estimated to be 1.71 μ{sub B} and 1.70 μ{sub B}, respectively, which are in acceptable agreement with the experimental results. However, the calculated average magnetic moment of Fe atom in Fe{sub 80}B{sub 14}C{sub 6} amorphous alloy is about 1.62 μ{sub B}, which is far less than the experimental result.

  3. Influence of corrosion on surface magnetic density in amorphous and nanocrystalline Fe{sub 73.5}Cu{sub 1}Nb{sub 3}Si{sub 13.5}B{sub 9} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Tejedor, M [Departamento de FIsica, Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); GarcIa, J A [Departamento de FIsica, Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Elbaile, L [Departamento de FIsica, Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo, (Spain); Santos, J D [Departamento de FIsica, Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Pierna, A R [Departamento de IngenierIa QuImica y Medio Ambiente, Universidad del PaIs Vasco, PO Box 1379, 20080 San Sebastian (Spain); Vara, G [Departamento de IngenierIa QuImica y Medio Ambiente, Universidad del PaIs Vasco, PO Box 1379, 20080 San Sebastian (Spain); Marzo, F F [Departamento de IngenierIa QuImica y Medio Ambiente, Universidad del PaIs Vasco, PO Box 1379, 20080 San Sebastian (Spain)

    2004-04-21

    The variation of surface magnetization with corrosion in Fe{sub 73.5}Cu{sub 1}Nb{sub 3}Si{sub 13.5}B{sub 9} in the amorphous and nanocrystalline states is investigated. The results show that in the amorphous samples when the oxidized layer increases the surface saturation magnetization decreases. However, in the nanocrystalline samples the surface saturation magnetization does not change significantly with the corrosion process but the approximation to saturation is different in the non-oxidized and oxidized nanocrystalline samples. In the case of non-oxidized samples, the surface saturation magnetization is reached at a low applied magnetic field (1000 Am{sup -1}), whereas in the oxidized samples it is reached at a higher applied magnetic field of 7000 and 9000 Am{sup -1} for the samples annealed at 520 deg. C for 60 min and 30 min, respectively.

  4. Synthesis and properties of magnetic solid superacid: SO{sub 4}{sup 2-}/ZrO{sub 2}-B{sub 2}O{sub 3}-Fe{sub 3}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Guan Dahui [College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Fan Meiqing [College of Chemical Engineering, Jilin Technology Institute of Industry, Jilin 132011 (China); Wang Jun, E-mail: zhqw1888@sohu.com [College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); College of Chemical Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zhang Yan; Liu Qi; Jing Xiaoyan [College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China)

    2010-07-01

    A magnetic SO{sub 4}{sup 2-}/ZrO{sub 2}-B{sub 2}O{sub 3}-Fe{sub 3}O{sub 4} solid superacid catalyst is prepared via a simple chemical co-precipitation approach. The obtained materials were characterized in detailed by X-ray powder diffraction, thermogravimetric analysis-different scanning calorimetry, Fourier transform infrared spectroscopy (FTIR), electron microscopy (SEM and TEM), and Mossbauer spectra. Powder X-ray diffraction patterns show that in this composite oxide the transformation temperature of ZrO{sub 2} from tetragonal to monoclinic phase is higher compared to the pristine SO{sub 4}{sup 2-}/ZrO{sub 2} material. The introduction of Fe{sub 3}O{sub 4} endows the superacid with a super-paramagnetic property while in a ferromagnetic state after calcination. The superacid exhibits high catalytic activity in forming ethyl acetate by esterification.

  5. Role of titanium valence states in optical and electronic features of PbO-Sb{sub 2}O{sub 3}-B{sub 2}O{sub 3}:TiO{sub 2} glass alloys

    Energy Technology Data Exchange (ETDEWEB)

    Satyanarayana, T. [Department of Physics, Acharya Nagarjuna University, Nuzvid Campus, Nuzvid 521201, A.P. (India); Kityk, I.V., E-mail: Iwan.Kityk@polsl.p [Chemical Department, Silesian Technological University, ul.Strzody 9, Gliwice (Poland); Electrical Engineering Department, Technical University of Czestochowa, Al.Armii Krajowej 17/19, Czestohcowa (Poland); Ozga, K. [Chair of Public Health, Technical University of Czestochowa, Al. Armii Krajowej 36 B (Poland); Piasecki, M.; Bragiel, P. [Institute of Physics, J. Dlugosz University Czestochowa, Al. Armii Krajowej 13/15, Czestochowa (Poland); Brik, M.G. [Institute of Physics, University of Tartu, Riia 142, Tartu 51014 (Estonia); Ravi Kumar, V. [Department of Physics, Acharya Nagarjuna University, Nuzvid Campus, Nuzvid 521201, A.P. (India); Reshak, A.H. [Institute of Physical Biology, South Bohemia University, NoVe Hrady 37333 (Czech Republic); Veeraiah, N. [Department of Physics, Acharya Nagarjuna University, Nuzvid Campus, Nuzvid 521201, A.P. (India)

    2009-08-12

    PbO-Sb{sub 2}O{sub 3}-B{sub 2}O{sub 3} glasses mixed with different concentrations of TiO{sub 2} (ranging from 0 to 1.5 mol.%) were synthesized. The samples are characterized by X-ray diffraction, scanning electron microscopy and DSC techniques. A variety of properties, i.e. optical absorption, photoluminescence, infrared, ESR spectra, magnetic susceptibility, photo-induced birefringence (PIB) and dielectric properties (constant epsilon', loss tan delta, a.c. conductivity sigma{sub ac} over a wide range of frequency and temperature) of these glass-ceramics have been explored. The analysis of these results indicated that Ti ion surrounding ligands play principal role in the observed PIB and the sample crystallized with 0.8 mol.% of TiO{sub 2} is the most suitable for the applications in non-linear optical devices.

  6. Nano and micro reoriented domains and their relation with the crystal structure in the new ferroelectric boracite Zn{sub 3}B{sub 7}O{sub 13}Br

    Energy Technology Data Exchange (ETDEWEB)

    Campa-Molina, J [Centro Universitario de la Cienega, Universidad de Guadalajara, Laboratorio de Materiales, Avenida Universidad No. 1115, Colonia Linda Vista, CP 47840, Ocotlan, Jalisco (Mexico); Ulloa-Godinez, S [Centro Universitario de la Cienega, Universidad de Guadalajara, Laboratorio de Materiales, Avenida Universidad No. 1115, Colonia Linda Vista, CP 47840, Ocotlan, Jalisco (Mexico); Barrera, A [Centro Universitario de la Cienega, Universidad de Guadalajara, Laboratorio de Materiales, Avenida Universidad No. 1115, Colonia Linda Vista, CP 47840, Ocotlan, Jalisco (Mexico); Bucio, L [Instituto de Fisica, UNAM, Apartado Postal 20-364, 01000 Mexico, DF (Mexico); Mata, J [Centro de Ciencias de la Materia Condensada, UNAM, Apartado Postal 2681, E-22800, Ensenada, BC (Mexico)

    2006-05-24

    A new zinc brome boracite Zn{sub 3}B{sub 7}O{sub 13}Br has been grown by a chemical transport reaction in closed quartz ampoules at 920 K. The crystal structure was characterized by Rietveld refinement. Ferroelectric nano and micro reorientable domains were found in this material using polarizing optical microscopy (PLM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Chemical analysis was performed with x-ray energy dispersive spectroscopy (EDX). In the crystal, a new structure transition at 586 K from orthorhombic (Pca 2{sub 1}) to cubic cell (F4-bar3c) has been found. This transition was corroborated by differential scanning calorimetry (DSC)

  7. Crossrelaxations and non-radiative energy transfer from ({sup 4}G{sub 5/2}) Sm{sup 3+} → ({sup 5}D{sub 0}) Eu{sup 3+}: B{sub 2}O{sub 3}–ZnO glasses

    Energy Technology Data Exchange (ETDEWEB)

    Naresh, V., E-mail: varna.naresh@gmail.com; Rudramadevi, B.H.; Buddhudu, S., E-mail: profsb_svuniv@hotmail.com

    2015-05-25

    Graphical abstract: The energy transfer process occurring from Sm{sup 3+} to Eu{sup 3+} in B{sub 2}O{sub 3}–ZnO (BZn) glasses is analyzed. Based on the Foster–Dexter theory, the possibility of energy transfer between Sm{sup 3+} and Eu{sup 3+} has been demonstrated from the spectral overlap of Eu{sup 3+} absorption and Sm{sup 3+} emission, photoluminescence spectra, energy level diagram and lifetime measurements. The energy transfer mechanism in (Sm{sup 3+} + Eu{sup 3+}) co-doped glass is governed by dipole–dipole interaction. - Highlights: • Spectroscopic properties of individually doped Sm{sup 3+}, Eu{sup 3+} & co-doped (Sm{sup 3+} + Eu{sup 3+}) in BZn glasses were studied separately. • The effect of Eu{sup 3+} concentration on luminescence properties is explained from cross-relaxations. • Energy transfer from Sm{sup 3+} ({sup 4}G{sub 5/2}) to Eu{sup 3+} ({sup 5}D{sub 0}) has been explained from Foster–Dexter theory. • Dipole–dipole mechanism governs the energy transfer from Sm{sup 3+} to Eu{sup 3+}. - Abstract: The present paper reports on the results concerning to photoluminescence features of Eu{sup 3+}, Sm{sup 3+} ions and energy transfer process occurring from Sm{sup 3+} to Eu{sup 3+} doped in 45 B{sub 2}O{sub 3}–55 ZnO (BZn) glasses prepared by melt quenching technique. Luminescence quenching as a function of Eu{sup 3+} concentration in BZn glasses has been discussed. Among the studied concentrations, 0.5 mol% of Eu{sup 3+} is optimized because it has exhibited red emission transition {sup 5}D{sub 0} → {sup 7}F{sub 2}. With regard to Sm{sup 3+} glasses, orange emission at 602 nm ({sup 4}G{sub 5/2} → {sup 6}H{sub 7/2}) has been noticed on exciting with λ{sub exci} = 403 nm. Based on the Foster–Dexter theory, the possibility of energy transfer between Sm{sup 3+} and Eu{sup 3+} has been explained from the spectral overlap of Eu{sup 3+} absorption and Sm{sup 3+} emission. The optimized concentration 0.5 mol% of Eu{sup 3+} is co

  8. Volumetric properties of ascorbic acid (vitamin C) and thiamine hydrochloride (vitamin B{sub 1}) in dilute HCl and in aqueous NaCl solutions at (283.15, 293.15, 298.15, 303.15, 308.15, and 313.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Ayranci, Guler; Sahin, Melike [Chemistry Department, Akdeniz University, 07058 Antalya (Turkey); Ayranci, Erol [Chemistry Department, Akdeniz University, 07058 Antalya (Turkey)], E-mail: eayranci@akdeniz.edu.tr

    2007-12-15

    Apparent molar volumes and apparent molar isentropic compressibilities of ascorbic acid (vitamin C) and thiamine hydrochloride (vitamin B{sub 1}) were determined from accurately measured density and sound velocity data in water and in aqueous NaCl solutions at (283.15, 293.15, 298.15, 303.15, 308.15, and 313.15) K. These volume and compressibility data were extrapolated to zero concentration using suitable empirical or theoretical equations to determine the corresponding infinite dilution values. Apparent molar expansibilities at infinite dilution were determined from slopes of apparent molar volume vs. temperature plots. Ionization of both ascorbic acid and thiamine hydrochloride were suppressed using sufficiently acidic solutions. Apparent molar volumes at infinite dilution for ascorbic acid and thiamine hydrochloride were found to increase with temperature in acidic solutions and in the presence of co-solute, NaCl. Apparent molar expansibility at infinite dilution were found to be constant over the temperature range studied and were all positive, indicating the hydrophilic character of the two vitamins studied in water and in the presence of co-solute, NaCl. Apparent molar isentropic compressibilities of ascorbic acid at infinite dilution were positive in water and in the presence of co-solute, NaCl, at low molalities. Those of thiamine hydrochloride at infinitive dilution were all negative, consistent with its ionic nature. Transfer apparent molar volumes of vitamins at infinite dilution from water solutions to NaCl solutions at various temperatures were determined. The results were interpreted in terms of complex vitamin-water-co-solute (NaCl) interactions.

  9. Study of influence content of TiB{sub 2} by reaction in situ B{sub 4}C and TiC in mechanical properties on B4C ceramics; Estudo da infuencia do teor de TIB{sub 2}, obtido pela reacao in sutu de B{sub 4}C de TiC, nas propriedades mecanicas de ceramicas a base de B{sub 4}C

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, M.L. Ramos; Bressiani, J.C. [Instituto de Pesquisa Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Gomide, R.G.; Andrade, F.A. de, E-mail: maluraco@usp.br, E-mail: gomide@ctmsp.mar.mil.br, E-mail: fernando.andrade@ctmsp.mar.mil.br, E-mail: jbressia@ipen.br [Centro Tecnologico da Marinha em Sao Paulo (CTMS), Sao Paulo, SP (Brazil)

    2012-07-01

    The low density of ceramic materials promoted a change in research lines in the defense field. Research efforts and development directed to obtaining products of high density sintered of Al2O3, SiC and B4C, using different routes, both traditional as innovative, led to promising initial results, which justify the convergence of skills for the consolidation of research lines and the nationalization that sintered components of B4C with characteristics and properties compatible with the technical requirements established for the ballistic application. The low density of boron carbide (2.52 g/cm{sup 3}) gives in the final product a weight approximately 30% lower than armor made of alumina (3.96 g/cm{sup 3}). (author)

  10. Synthesis, crystal structure, and properties of an interesting elliptical vanadoborate housing crystal: [Ni(en){sub 2}]{sub 6}[(VO){sub 12}O{sub 6}B{sub 18}O{sub 39}(OH){sub 3}]·5H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xiangzhan; Dong, Xiaoyu [Key Laboratory of Functional Materials and Devices for Special Environments of CAS, Xinjiang Technical Institute of Physics and Chemistry of CAS, Xinjiang Key Laboratory of Electronic Information Materials and Devices, 40-1 South Beijing Road, 830011 Urumqi (China); Key Laboratory at Universities of Education Department of Xinjiang Uygur Autonomous Region for New Energy Materials, Xinjiang Institute of Engineering, 830091 Urumqi (China); Pan, Shilie, E-mail: slpan@ms.xjb.ac.cn [Key Laboratory of Functional Materials and Devices for Special Environments of CAS, Xinjiang Technical Institute of Physics and Chemistry of CAS, Xinjiang Key Laboratory of Electronic Information Materials and Devices, 40-1 South Beijing Road, 830011 Urumqi (China); Han, Jian, E-mail: hanjian@ms.xjb.ac.cn [Key Laboratory of Functional Materials and Devices for Special Environments of CAS, Xinjiang Technical Institute of Physics and Chemistry of CAS, Xinjiang Key Laboratory of Electronic Information Materials and Devices, 40-1 South Beijing Road, 830011 Urumqi (China); Yang, Yun; Zhang, Fangyuan; Yu, Hongwei [Key Laboratory of Functional Materials and Devices for Special Environments of CAS, Xinjiang Technical Institute of Physics and Chemistry of CAS, Xinjiang Key Laboratory of Electronic Information Materials and Devices, 40-1 South Beijing Road, 830011 Urumqi (China)

    2015-03-05

    Highlights: • We synthesize a new organic–inorganic vanadoborate under a hydrothermal condition. • The crystal contains a novel elliptical housing with V{sub 12}B{sub 18}O{sub 60} clusters. • The physical and chemical properties of the crystal are described. - Abstract: A new vanadoborate, [Ni(en){sub 2}]{sub 6}[(VO){sub 12}O{sub 6}B{sub 18}O{sub 39}(OH){sub 3}]·5H{sub 2}O, has been synthesized under a hydrothermal condition. It crystallizes into rhombohedral crystal system with centrosymmetric space group of R3{sup ‾} with a = 20.824(7) Å, c = 21.050(14) Å, Z = 3. The crystal contains a novel elliptical housing with V{sub 12}B{sub 18}O{sub 60} clusters. Around the housing, there is six nickel atoms coordinated with two ethylenediamine molecules. The oxidation states of vanadium in the compound are V(IV) and V(V). The characterizations by powder X-ray diffraction, infrared spectroscopy, UV–Vis diffuse reflectance spectrum, and TG curve are also described.

  11. Influence of crystal field potential on the spectroscopic parameters of SiO{sub 2}.B{sub 2}O{sub 3}.PbO glass doped with Nd{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, N.O.; Serqueira, E.O. [Laboratorio de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Fisica, Universidade Federal de Uberlandia, CP593, 38400-902, Uberlandia-MG (Brazil); Bell, M.J.V., E-mail: mjbell@fisica.ufjf.b [Laboratorio de Espectroscopia de Materiais, Departamento de Fisica, Universidade Federal de Juiz de Fora, Juiz de Fora-MG, 36036-330 (Brazil); Anjos, V.; Carvalho, E.A. [Laboratorio de Espectroscopia de Materiais, Departamento de Fisica, Universidade Federal de Juiz de Fora, Juiz de Fora-MG, 36036-330 (Brazil); Lourenco, S.A. [Universidade Tecnologica Federal do Parana-Campus Apucarana, 86812-460, Apucarana-PR (Brazil); Pereira-da-Silva, M.A. [Instituto de Fisica de Sao Carlos, USP, Sao Carlos, SP 13560-250 (Brazil); Centro Universitario Central Paulista, UNICEP, Sao Carlos, SP 13563-470 (Brazil)

    2011-05-15

    This paper presents the optical characteristics of Nd{sup 3+} silicate glass (SiO{sub 2}-B{sub 2}O{sub 3}-PbO), synthesized by the fusion method. Two sets of samples were prepared: glass and corresponding glass ceramics. Optical absorption, luminescence, Raman spectroscopy and atomic force microscopy (AFM) measurements were performed in order to determine the structural properties of the systems and the radiative characteristics of Nd{sup 3+} ions. Near infrared luminescence exhibited typical Nd{sup 3+} bands. Raman and AFM measurements indicated nanocrystal growth with thermal treatment of the glass ceramics. Judd-Ofelt calculations also confirmed that heat treatment induced structural rearrangement of the samples that was dependent on Nd{sub 2}O{sub 3} concentration. This resulted in changes in the optical and physical properties of the samples, including stimulated emission cross section and rigidity. - Research highlights: {yields} Glass and glass-ceramics were formed as a function of heat treatment. {yields} Heat treatment induced structural rearrangement that depends on Nd{sub 2}O{sub 3} concentration. {yields} Structural rearrangement of the glasses was detected by Raman and AFM measurements. {yields} Judd Ofelt theory show changes in the stimulated emission cross section and rigidity of the samples.

  12. Tb{sub 2}Ni{sub 2}Mg{sub 3}: a new structure type derived from the Ru{sub 3}Al{sub 2}B{sub 2} type

    Energy Technology Data Exchange (ETDEWEB)

    Solokha, P. [Ivan Franko National Univ. of Lviv (Ukraine). Dept. of Inorganic Chemistry; De Negri, S.; Saccone, A. [Genova Univ. (Italy). Sezione di Chimica Inorganica e Metallurgia; Pavlyuk, V. [Ivan Franko National Univ. of Lviv (Ukraine). Dept. of Inorganic Chemistry; Jan Dlugosz Univ., Czestochowa (Poland). Inst. of Chemistry and Environment Protection; Marciniak, B. [Jan Dlugosz Univ., Czestochowa (Poland). Inst. of Chemistry and Environment Protection; Tedenac, J.C. [Montpellier II Univ., 34 (France). Lab. de Phisico-chimie de la Matiere Condensee; LPMC UMR CNRS, 34 - Montpellier (France)

    2007-02-15

    Single crystals of diterbium dinickel trimagnesium, Tb{sub 2}Ni{sub 2}Mg{sub 3}, were synthesized from the elements by induction melting. The novel compound crystallizes in the space group Cmmm with one Mg atom of site symmetry mmm and the Tb, Ni and other Mg atom in m2m positions. This ternary compound represents a new structure type that is derived from Ru{sub 3}Al{sub 2}B{sub 2} by way of Wyckoff site distribution. The twolayer structure of Tb{sub 2}Ni{sub 2}Mg{sub 3} is a new representative of a homologous linear structure series of general formula R'{sub k+n}X{sub 2n}R''{sub 200m+k} based on structural fragments of the {alpha}-Fe, CsCl and AlB{sub 2} structure types. The Tb atoms in the structure are enclosed in 17-vertex polyhedra, while rhombododecahedra and distorted rhombododecahedra surround the Mg atoms, and equatorially tricapped trigonal prisms form around the Ni atoms. All interatomic distances indicate metallic type bonding. (orig.)

  13. Absorption and magnetic circular dichroism (MCD) studies of 1,4,5,8-naphthalenetetracarboxy diimides in terms of CASSCF method and FC theory

    Energy Technology Data Exchange (ETDEWEB)

    Sterzel, Mariusz; Andrzejak, Marcin; Pawlikowski, Marek T.; Gawronski, J

    2004-05-10

    The electronic and geometrical structures of the low-energy states of 1,4,5,8-naphthalenetetracarboxylic dianhydride parent diimide (1) are studied in terms of the complete active space self-consistent field (CASSCF) method employed at different level with respect to the size and the quality of the active space. In the framework of the vibronic model based on the Franck-Condon (FC) effect the absorption and magnetic circular dichroism (MCD) spectra are studied in the excitation region corresponding to two low-energy 1{sup 1}A{sub g} {yields} 1{sup 1}B{sub 2u} and 1{sup 1}A{sub g} {yields} 1{sup 1}B{sub 3u} electronic transitions in diimides. In that (visible) excitation region the CASSCF computations with the 5{pi}[4n]5{pi} active space (i.e., the naphthalene-like {pi} orbitals enriched by the four lone pair orbitals of the oxygen atoms) were found to reproduce very well the empirical absorption and the MCD spectra measured for the dicyclohexyl-N,N{sup '}-substituted diimide (2). At the same CASSCF/5{pi}[4n]5{pi} level, the electronic absorption of diimides in the near UV excitation region were attributed to the 1{sup 1}A{sub g} {yields} 2{sup 1}B{sub 1u}, 1{sup 1}A{sub g} {yields} 2{sup 1}B{sub 3u} and 1{sup 1}A{sub g} {yields} 2{sup 1}B{sub 2u} electronic transitions; the latter two are mostly localized on the ''diimide chromophore''. For these transitions the calculated magneto-optical characteristics, such as sign pattern and intensity distribution in the MCD spectrum, were found to be consistent with that experimentally observed for the diimide 2 compound.

  14. Structural stability of boron carbide under pressure proven by spectroscopic studies up to 73 GPa

    Energy Technology Data Exchange (ETDEWEB)

    Chuvashova, Irina [Material Physics and Technology at Extreme Conditions, Laboratory of Crystallography, University of Bayreuth (Germany); Bayerisches Geoinstitut, University of Bayreuth (Germany); Gasharova, Biliana; Mathis, Yves-Laurent [IBPT, Karlsruhe Institute of Technology, Karlsruhe (Germany); Dubrovinsky, Leonid [Bayerisches Geoinstitut, University of Bayreuth (Germany); Dubrovinskaia, Natalia [Material Physics and Technology at Extreme Conditions, Laboratory of Crystallography, University of Bayreuth (Germany)

    2017-11-17

    Being a material of choice for lightweight armor applications, boron carbide has been intensively studied. Its behavior under pressure was investigated using both theoretical and experimental methods, such as powder X-ray diffraction and vibrational spectroscopy. As there is a discrepancy in experimental observations, in the presented work we studied vibrational properties of commercially available, ''nearly stoichiometric'' B{sub 4}C using IR and Raman spectroscopy up to 73 GPa. No phase transitions were found in the entire pressure range. Our results are at odds with the recent report of a phase transition in B{sub 4.3}C at about 40 GPa. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. B{sub 2}O{sub 3}/Al{sub 2}O{sub 3} as a new, highly efficient and reusable heterogeneous catalyst for the selective synthesis of {beta}-enamino ketones and esters under solvent-free conditions

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jiu-Xi; Gao, Wen-Xia; Jin, Hui-Le; Ding, Jin-Chang; Wu, Hua-Yue, E-mail: huayuewu@wzu.edu.c [Wenzhou University, Wenzhou (China). Coll. of Chemistry and Materials Engineering; Zhang, Chang-Fu [Wenzhou Vocational and Technical College, Wenzhou (China)

    2010-07-01

    Boron oxide adsorbed on alumina (B{sub 2}O{sub 3}/Al{sub 2}O{sub 3}) has been found to be a new and highly efficient heterogeneous catalyst for the synthesis of {beta}-enamino ketones and esters by the enamination of various primary and secondary amines with {beta}-dicarbonyl compounds under solvent-free conditions. The important features of this methodology are broad substrate scope, high yield, no requirement of metal catalysts, high regio- and chemoselectivity and environmental friendliness. In addition, the catalyst could be recovered easily after the reactions and reused without evident loss of reactivity. (author)

  16. Enhance magnetocaloric effects in Mn{sub 1.15}Fe{sub 0.85}P{sub 0.52}Si{sub 0.45}B{sub 0.03} alloy achieved by copper-mould casting and annealing treatments

    Energy Technology Data Exchange (ETDEWEB)

    Yu, H.Y.; Zhu, Z.R.; Lai, J.W. [School of Materials Science & Engineering, South China University of Technology, Guangzhou 510640 (China); Zheng, Z.G., E-mail: mszgzheng@scut.edu.cn [School of Materials Science & Engineering, South China University of Technology, Guangzhou 510640 (China); Zeng, D.C., E-mail: medczeng@scut.edu.cn [School of Materials Science & Engineering, South China University of Technology, Guangzhou 510640 (China); Zhang, J.L. [Department of Physics and Materials Science, City University of Hong Kong, Hong Kong (China)

    2015-11-15

    The Mn{sub 1.15}Fe{sub 0.85}P{sub 0.52}Si{sub 0.45}B{sub 0.03} rods were prepared by copper mould suction casting. The effects of heat treatments on the structure and magnetocaloric properties have been investigated. The X-ray diffraction patterns indicated that the annealed Mn{sub 1.15}Fe{sub 0.85}P{sub 0.52}Si{sub 0.45}B{sub 0.03} rods present hexagonal Fe{sub 2}P-type structure with a small amount of Mn{sub 3}Fe{sub 2}Si{sub 3} impurity. With elevated annealing temperatures from 1123 K to 1423 K, the Curie temperature increases from 205 K to 251 K, the magnetic entropy change jumps from 0.6 to 19.8 J kg{sup –1}K{sup −1} under a magnetic field change of 0–2 T and the thermal hysteresis is reduced from 17 K to 10.5 K. Thus, the heat treatment is suggested to be an effective way to enhance the magnetocaloric effects of Mn{sub 1.15}Fe{sub 0.85}P{sub 0.52}Si{sub 0.45}B{sub 0.03} alloys. - Highlights: • Mn{sub 1.15}Fe{sub 0.85}P{sub 0.52}Si{sub 0.45}B{sub 0.03} alloy was prepared by copper mould suction casting method. • Curie temperature and magnetic entropy change can be tuned by heat treatment. • The −ΔS{sub M} for annealed alloys reaches 19.8 J kg{sup −1}K{sup −1} under the magnetic field change of 0–2 T. • Magnetic transitions are tuned from second-order to first-order by annealing temperature.

  17. Analysis of cellular responses to aflatoxin B{sub 1} in yeast expressing human cytochrome P450 1A2 using cDNA microarrays

    Energy Technology Data Exchange (ETDEWEB)

    Guo Yingying [Departmental of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA (United States); Fred Hutchinson Cancer Research Center, Seattle, WA (United States); Breeden, Linda L. [Fred Hutchinson Cancer Research Center, Seattle, WA (United States); Fan, Wenhong [Fred Hutchinson Cancer Research Center, Seattle, WA (United States); Zhao Lueping [Fred Hutchinson Cancer Research Center, Seattle, WA (United States); Eaton, David L. [Departmental of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA (United States); Fred Hutchinson Cancer Research Center, Seattle, WA (United States); Zarbl, Helmut [Departmental of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA (United States) and Fred Hutchinson Cancer Research Center, Seattle, WA (United States)]. E-mail: hzarbl@fhcrc.org

    2006-01-29

    Aflatoxin B1 (AFB{sub 1}) is a potent human hepatotoxin and hepatocarcinogen produced by the mold Aspergillus flavus. In human, AFB{sub 1} is bioactivated by cytochrome P450 (CYP450) enzymes, primarily CYP1A2, to the genotoxic epoxide that forms N{sup 7}-guanine DNA adducts. To characterize the transcriptional responses to genotoxic insults from AFB{sub 1}, a strain of Saccharomyces cerevisiae engineered to express human CYP1A2 was exposed to doses of AFB{sub 1} that resulted in minimal lethality, but substantial genotoxicity. Flow cytometric analysis demonstrated a dose and time dependent S phase delay under the same treatment conditions, indicating a checkpoint response to DNA damage. Replicate cDNA microarray analyses of AFB{sub 1} treated cells showed that about 200 genes were significantly affected by the exposure. The genes activated by AFB{sub 1}-treatment included RAD51, DUN1 and other members of the DNA damage response signature reported in a previous study with methylmethane sulfonate and ionizing radiation [A.P. Gasch, M. Huang, S. Metzner, D. Botstein, S.J. Elledge, P.O. Brown, Genomic expression responses to DNA-damaging agents and the regulatory role of the yeast ATR homolog Mec1p, Mol. Biol. Cell 12 (2001) 2987-3003]. However, unlike previous studies using highly cytotoxic doses, environmental stress response genes [A.P. Gasch, P.T. Spellman, C.M. Kao, O. Carmel-Harel, M.B. Eisen, G. Storz, D. Botstein, P.O. Brown, Genomic expression programs in the response of yeast cells to environmental changes, Mol. Biol. Cell 11 (2000) 4241-4257] were largely unaffected by our dosing regimen. About half of the transcripts affected are also known to be cell cycle regulated. The most strongly repressed transcripts were those encoding the histone genes and a group of genes that are cell cycle regulated and peak in M phase and early G1. These include most of the known daughter-specific genes. The rapid and coordinated repression of histones and M/G1-specific

  18. Beryllium-free β-Rb{sub 2}Al{sub 2}B{sub 2}O{sub 7} as a possible deep-ultraviolet nonlinear optical material replacement for KBe{sub 2}BO{sub 3}F{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Tran, T. Thao; Halasyamani, P. Shiv [Department of Chemistry, University of Houston, TX (United States); Koocher, Nathan Z.; Rondinelli, James M. [Department of Materials Science and Engineering, Northwestern University, Evanston, IL (United States)

    2017-03-06

    A new beryllium-free deep-ultraviolet (DUV) nonlinear optical (NLO) material, β-Rb{sub 2}Al{sub 2}B{sub 2}O{sub 7} (β-RABO), has been synthesized and characterized. The chiral nonpolar acentric material shows second-harmonic generation (SHG) activity at both 1064 and 532 nm with efficiencies of 2 x KH{sub 2}PO{sub 4} and 0.4 x β-BaB{sub 2}O{sub 4}, respectively, and exhibits a short absorption edge below 200 nm. β-Rb{sub 2}Al{sub 2}B{sub 2}O{sub 7} has a three-dimensional structure of corner-shared Al(BO{sub 3}){sub 3}O polyhedra. The discovery of β-RABO shows that through careful synthesis and characterization, replacement of KBe{sub 2}BO{sub 3}F{sub 2} (KBBF) by a Be-free DUV NLO material is possible. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Fabrication of CaO-ZrO{sub 2}-TiO{sub 2}-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}-SiO{sub 2} glasses and glass-ceramics. Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jing-Shi; Shen, Pouyan [Institute of Materials Science and Engineering, National Sun Yat-sen University, Kaohsiung (Taiwan, Province of China)

    1996-09-01

    The CaO-ZrO{sub 2}-TiO{sub 2}-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}-SiO{sub 2} glass, a potential glaze, solder and immobilizer of high-level radioactive wastes, was prepared from the powder batches of CaO-ZrO{sub 2}-TiO{sub 2} (C{sub 5}ZT, subscripts are molar ratios) with the additives of B{sub 2}O{sub 3}, SiO{sub 2} and Al{sub 2}O{sub 3} and at a firing temperature of 1200C. Upon heating (10C/min) for differential thermal analysis, all the glasses went through a glass transition event at 640C (peak temperature) and then two devitrification events at 800 and 900C, which caused the formation of m-ZrO{sub 2} and ZrO{sub 2}-derived phases (predominantly zirconolite, CaZrTi{sub 2}O{sub 7}), respectively. Glass-ceramics were further fabricated from the glass slabs by one-stage heating at 900C, which caused first the cellular layer and then spherulitic clusters of ZrO{sub 2} derivatives. When the glass-ceramics were subjected to prolonged annealing, the ZrO{sub 2}-derived phases always survived while borate, silicate and other phases appeared. The selection of zirconia-related phases during devitrification are discussed.

  20. Synthesis and characterization of a new quaternary borate Na{sub 2}Cs{sub 2}Sr(B{sub 9}O{sub 15}){sub 2} with the unprecedented [B{sub 9}O{sub 19}]{sup 11−} group, notation of 3 × (3:2Δ + T)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xuean, E-mail: xueanchen@bjut.edu.cn [College of Materials Science and Engineering, Beijing University of Technology, Ping Le Yuan 100, Beijing 100124 (China); Wu, Long; Wang, Kun; Chang, Xinan [College of Materials Science and Engineering, Beijing University of Technology, Ping Le Yuan 100, Beijing 100124 (China); Xiao, Weiqiang [Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124 (China)

    2015-02-25

    Graphical abstract: Na{sub 2}Cs{sub 2}Sr(B{sub 9}O{sub 15}){sub 2} represents a new structure type in which three [B{sub 3}O{sub 7}]{sup 5−} triborate groups are bridged by two common oxygen atoms to form a [B{sub 9}O{sub 19}]{sup 11−} group that is further condensed into a 3D {sup 3}{sub ∞}[B{sub 9}O{sub 15}]{sup 3-} network, with the intersecting open channels as well as pockets accommodating Cs{sup +}, Sr{sup 2+}, and Na{sup +} cations. - Highlights: • Na{sub 2}Cs{sub 2}Sr(B{sub 9}O{sub 15}){sub 2} has been synthesized and characterized. • It has a 3D network formed by the unprecedented [B{sub 9}O{sub 19}]{sup 11−} groups. • IR spectrum confirms the presence of low symmetric BO{sub 3} and BO{sub 4} groups. • UV–VIS diffuse reflectance spectrum shows a band gap of about 3.26 eV. • Band structure calculations indicate that it is an indirect band-gap insulator. - Abstract: A new sodium cesium strontium borate, Na{sub 2}Cs{sub 2}Sr(B{sub 9}O{sub 15}){sub 2}, has been synthesized and its crystal structure determined by single-crystal XRD methods. The compound crystallizes in the space group P2{sub 1}/c (No. 14) with the following cell parameters: a = 8.4670(17) Å, b = 8.5220(17) Å, c = 17.206(3) Å, β = 92.60(3)°, V = 1240.2(4) Å{sup 3}, Z = 2. It represents a new structure type in which three [B{sub 3}O{sub 7}]{sup 5−} triborate groups are bridged by two common oxygen atoms to form a [B{sub 9}O{sub 19}]{sup 11−} group that is further condensed into a 3D {sup 3}{sub ∞}[B{sub 9}O{sub 15}]{sup 3-} network, with the shorthand notation 9:∞{sup 3}[3 × (3:2Δ + T)], where Δ and T represent BO{sub 3} triangles and BO{sub 4} tetrahedra, respectively. The 3D borate anionic network also affords intersecting open channels as well as pockets that accommodate Cs{sup +}, Sr{sup 2+}, and Na{sup +} cations. IR spectrum further confirms that this compound contains low symmetric BO{sub 3} and BO{sub 4} groups. UV–VIS diffuse reflectance spectrum

  1. Uptake of radiolabeled morphiceptin and its analogs by experimental mammary adenocarcinoma: in vitro and in vivo studies

    Energy Technology Data Exchange (ETDEWEB)

    Mirowski, M. E-mail: mirowski@ich.pharm.am.lodz.pl; Wiercioch, R.; Janecka, A.; Balcerczak, E.; Byszewska, E.; Birnbaum, G.; Byzia, Sz.; Garnuszek, P.; Wierzbicki, R

    2004-05-01

    Morphiceptin (Tyr-Pro-Phe-Pro-NH{sub 2}) and its analogs modified at position 3: [D-Phe{sup 3}]morphiceptin, [D-ClPhe{sup 3}]morphiceptin and [D-Cl{sub 2}Phe{sup 3}]morphiceptin were synthesized and labeled with [{sup 125}I] or [{sup 131}I]. Their binding to membranes isolated from experimental adenocarcinoma was examined in vitro with the use of a cross-linking assay followed by the Western blot technique. The radioactive complex had molecular weight of about 65 kDa and was detectable by anti-{mu}-opioid receptor polyclonal antibody. Expression of the {mu}-opioid receptor in mouse mammary adenocarcinoma was confirmed by reverse transcriptase-polymerase chain reaction. The binding studies showed the highest affinity and capacity for [D-Phe{sup 3}]morphiceptin (K{sub d} 0.39 and B{sub max} 1112) and [D-ClPhe{sup 3}]morphiceptin (K{sub d} 1.8 and B{sub max} 220). Morphiceptin and its D-Cl{sub 2}Phe analog had significantly lower B{sub max} values (131 and 83, respectively). Biodistribution experiments in tumor-bearing C3H/Bi mice with the use of the {sup 131}I-labeled peptides confirmed the results of our in vitro studies. The highest accumulation of radioactive peptides in the tumor tissue was also found for peptides with D-Phe and D-ClPhe.

  2. Chirality and polarity in the f-block borates M{sub 4}[B{sub 16}O{sub 26}(OH){sub 4}(H{sub 2}O){sub 3}Cl{sub 4}] (M=Sm, Eu, Gd, Pu, Am, Cm, and Cf)

    Energy Technology Data Exchange (ETDEWEB)

    Polinski, Matthew J.; Pace, Kristen A.; Stritzinger, Jared T.; Lin, Jian; Cross, Justin N.; Cary, Samantha K.; Albrecht-Schmitt, Thomas E. [Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL (United States); Van Cleve, Shelley M. [Nuclear Materials Processing Group, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Alekseev, Evgeny V. [Institute for Energy and Climate Research (IEK-6), Forschungszentrum Juelich GmbH (Germany); Institut fur Kristallographie, Rheinisch-Westfaelische Technische Hochschule University, Aachen (Germany)

    2014-08-04

    The reactions of trivalent lanthanides and actinides with molten boric acid in high chloride concentrations result in the formation of M{sub 4}[B{sub 16}O{sub 26}(OH){sub 4}(H{sub 2}O){sub 3}Cl{sub 4}] (M=Sm, Eu, Gd, Pu, Am, Cm, Cf). This cubic structure type is remarkably complex and displays both chirality and polarity. The polymeric borate network forms helical features that are linked via two different types of nine-coordinate f-element environments. The f-f transitions are unusually intense and result in dark coloration of these compounds with actinides. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Glass forming ability and magnetic properties of Co{sub (40.2−x)}Fe{sub (20.1+x)}Ni{sub 6.7}B{sub 22.7}Si{sub 5.3}Nb{sub 5} (x=0–10) bulk metallic glasses produced by suction casting

    Energy Technology Data Exchange (ETDEWEB)

    Sarlar, Kagan [Physics Department, Faculty of Arts and Sciences, Uludag University, Gorukle Campus, 16059 Bursa (Turkey); Physics Department, Kamil Ozdag Faculty of Sciences, Karamanoglu Mehmetbey University, YunusEmre Campus, 70100 Karaman (Turkey); Kucuk, Ilker, E-mail: ikucuk@uludag.edu.tr [Physics Department, Faculty of Arts and Sciences, Uludag University, Gorukle Campus, 16059 Bursa (Turkey)

    2015-01-15

    The effect of Fe concentration on the glass forming ability (GFA) and magnetic properties in Co{sub (40.2−x)}Fe{sub (20.1+x)}Ni{sub 6.7}B{sub 22.7}Si{sub 5.3}Nb{sub 5} (x=0–10) bulk metallic glasses were investigated. By suction casting method, the bulk metallic glasses with diameters up to 2 mm were produced. We try to find out which Fe concentration makes an influence on Co based system's magnetic properties and glass forming ability. The curves of thermal analysis, obtained using differential scanning calorimetry (DSC), show that the Co{sub (40.2−x)}Fe{sub (20.1+x)}Ni{sub 6.7}B{sub 22.7}Si{sub 5.3}Nb{sub 5} (x=0–10) have a supercooled liquid region (∆T{sub x}) of about 44 K. The saturation magnetizations (J{sub s}) for as-cast BMG alloys were in the range of 0.62 T−0.81 T. - Highlights: • The effect of Fe concentration on the glass forming ability. • The substitution of an appropriate amount of Fe can enhance the GFA. • The substitution of Fe for Co also improves soft magnetic properties of the BMGs. • The high of J{sub s} 0.62−0.81 T with a low H{sub c} of 2−289 A/m of the alloys.

  4. Communication: Rovibrationally selected absolute total cross sections for the reaction H{sub 2}O{sup +}(X{sup 2}B{sub 1}; v{sub 1}{sup +}v{sub 2}{sup +}v{sub 3}{sup +}= 000; N{sup +}{sub Ka+Kc+)}+ D{sub 2}: Observation of the rotational enhancement effect

    Energy Technology Data Exchange (ETDEWEB)

    Xu Yuntao; Xiong Bo; Chang, Yih Chung; Ng, C. Y. [Department of Chemistry, University of California, Davis, California 95616 (United States)

    2012-12-28

    By employing the newly established vacuum ultraviolet laser pulsed field ionization-photoion (PFI-PI) double quadrupole-double octopole ion guide apparatus, we have measured the rovibrationally selected absolute total cross sections of the ion-molecule reaction H{sub 2}O{sup +}(X{sup 2}B{sub 1}; v{sub 1}{sup +}v{sub 2}{sup +}v{sub 3}{sup +}= 000; N{sup +}{sub Ka+Kc+)}+ D{sub 2}{yields} H{sub 2}DO{sup +}+ D in the center-of-mass collision energy (E{sub cm}) range of 0.05-10.00 eV. The pulsing scheme used for the generation of PFI-PIs has made possible the preparation of reactant H{sub 2}O{sup +}(X{sup 2}B{sub 1}; v{sub 1}{sup +}v{sub 2}{sup +}v{sub 3}{sup +}= 000) ions in single N{sup +}{sub Ka+Kc+} rotational levels with high kinetic energy resolutions. The absolute total cross sections observed in different N{sup +}{sub Ka+Kc+} levels with rotational energies in the range of 0-200 cm{sup -1} were found to exhibit a significant rotational enhancement on the reactivity for the titled reaction. In contrast, the measured cross sections reveal a decreasing trend with increasing E{sub cm}, indicating that the rotational enhancement observed is not a total energy effect, but a dynamical effect. Furthermore, the rotational enhancement is found to be more pronounced as E{sub cm} is decreased. This experiment provided evidence that the coupling of the core rotational angular momentum with the orbital angular momentum could play a role in chemical reactivity, particularly at low E{sub cm}.

  5. About LTCC materials in the substance system of CaO-La{sub 2}O{sub 3}-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}; Ueber LTCC-Werkstoffe aus dem Stoffsystem CaO-La{sub 2}O{sub 3}-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Gemeinert, Marion

    2009-09-01

    Glass ceramic composites made of glassy and crystalline powders offer numerous possibilities for modifying materials properties e.g. sintering behaviour, thermal expansion coefficient, mechanical behaviour, chemical durability, dielectric properties and surface quality for special use. Glass ceramic composite powders can be used for the production of ceramic green tapes which are processed by LTCC (Low Temperature Co-fired Ceramics)- technology to form ceramic multilayers for electronic packaging in microsystems. During free sintering of LTCC-multilayers a lateral shrinkage occurs which is connected with a comparatively high shrinkage tolerance. Different sintering technologies are used to avoid the lateral shrinkage. A new possibility to achieve a zero lateral shrinkage is given by use of a self-constrained laminate. Therefore a multilayer is produced of two different materials for inner and outer layers, showing different sintering temperatures ({delta}T>50 K). Object of this dissertation was the development of LTCC-materials, which can be used for inner layers of a self-constrained laminate to reduce the lateral shrinkage nearly to zero. Therefore LTCC-materials in the field of CaO-La{sub 2}O{sub 3}-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}, which can be sintered below 800 C, were investigated. Starting from the development of adapted glasses based on calcium lanthanium borate- and calcium lanthanium alumoborate glasses glass ceramic composites were produced by the addition of corundum powder. The composites crystallize during the sintering process almost completely. Lanthanum borate crystallizes from the glassy phase and calcium alumoborate and calcium alumoborate oxide respectively is formed by a chemical solid state reaction of the residual glassy phase, which is enriched by calcium borate, and the corundum. The proportional relation of the new crystalline phases determines the thermal and dielectric properties of the material. The most important formed new

  6. Study of crystallization processes in Gd-substituted Finemet alloys

    Energy Technology Data Exchange (ETDEWEB)

    Crisan, O. [National Institute for Materials Physics, P.O. Box MG-07, 77125 Bucharest-Magurele (Romania)]. E-mail: ocrisan@yahoo.com; Le Breton, J.M. [GPM, UMR 6634 CNRS, Universite de Rouen, 76801 St. Etienne du Rouvray Cedex (France); Crisan, A.D. [National Institute for Materials Physics, P.O. Box MG-07, 77125 Bucharest-Magurele (Romania); Filoti, G. [National Institute for Materials Physics, P.O. Box MG-07, 77125 Bucharest-Magurele (Romania)

    2006-09-28

    The crystallization processes that occur in amorphous melt-spun ribbons of nominal composition Fe{sub 73.5}Cu{sub 1}Nb{sub 3}Si{sub 13.5}B{sub 9} with Gd addition in different concentrations are studied by differential scanning calorimetry (DSC). The aim of Gd addition is to study the changes induced in the calorimetric behavior of Finemet alloys, the crystallization sequences at intermediate stages of annealing as well as the nature of obtained crystallization products. The nature and structural properties of the phases formed at the end of the calorimetric process are investigated using X-ray diffraction (XRD) and Moessbauer spectrometry (MS). The crystallization sequence and also the phase composition at different stages of annealing were investigated for the Fe{sub 68.5}Gd{sub 5}Cu{sub 1}Nb{sub 3}Si{sub 13.5}B{sub 9} alloy. Structure and magnetic properties of resulting crystallized samples have been thoroughly investigated. It is shown that in the above-mentioned composition, the decomposition at around 690 deg. C of the metastable Gd{sub 3}Fe{sub 62}B{sub 14} phase formed at incipient stages of crystallization leads to the co-existence of Gd{sub 2}Fe{sub 14}B, Fe{sub 2}B and {alpha}-Fe(Si) phases. Magnetic measurements of as-cast and annealed samples are in good agreement with the XRD and MS results and with the proposed crystallization sequences and decomposition of intermediate metastable phases.

  7. Spectroscopic and energy transfer studies of Er{sup 3+} ions in B{sub 2}O{sub 3}–TeO{sub 2}–MgO–ZnO glasses

    Energy Technology Data Exchange (ETDEWEB)

    Vijayakumar, M.; Arunkumar, S.; Marimuthu, K., E-mail: mari-ram2000@yahoo.com [Department of Physics, Gandhigram Rural Institute - Deemed University, Gandhigram – 624 302 (India); Maheshvaran, K. [Department of Physics, Kongu Engineering College, Perundurai, Erode-638 052 (India)

    2016-05-23

    Composition dependent spectroscopic behavior of Er{sup 3+} doped telluroborate glasses were prepared and the energy transfer mechanism in Er{sup 3+} ions were investigated for 1.532 µm amplification. The emission cross-section and gain coefficient for {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} level of Er{sup 3+} ions have been analysed through the Judd-Ofelt and McCumber theory. The excited state decay curves were measured and the effect of TeO{sub 2} on the lifetime for {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} level of Er{sup 3+} ions has been associated with the various energy transfer mechanism. Further the interaction between Er{sup 3+} and OH{sup −} were investigated and it was confirmed that the OH free radicals in the prepared glasses are dominant quenching center through the non-radiative relaxation that causes the quenching of 1.532 µm amplification. The non-radiative rate through the OH content were calculated and compared with the reported Er{sup 3+} doped glasses.

  8. Critical behavior of resistivity in the pressure-induced first to second order transition in Pr{sub 0.6}Ca{sub 0.4}Mn{sub 0.96}B{sub 0.04}O{sub 3} (B = Co and Cr)

    Energy Technology Data Exchange (ETDEWEB)

    Thiyagarajan, R.; Esakki Muthu, S.; Kalai Selvan, G. [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu (India); Mahendiran, R. [Department of Physics, 2 Science Drive 3, Faculty of Science, National University of Singapore, Singapore 117551 (Singapore); Arumugam, S., E-mail: sarumugam1963@yahoo.com [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu (India)

    2015-01-05

    Highlights: • 1st order PMI–FMM transition at T{sub IM} Pr{sub 0.6}Ca{sub 0.4}Mn{sub 0.96}B{sub 0.04}O{sub 3} (B = Co and Cr) samples. • Crossover from 1st to 2nd order is observed by the application of P on both the samples. • Critical exponents’ are close to the 3D Heisenberg model for the Co doped sample. • Critical exponents’ are close to the Mean field model for the Cr doped sample. - Abstract: We have investigated the hydrostatic pressure (P) dependence of the resistivity on Pr{sub 0.6}Ca{sub 0.4}Mn{sub 0.96}B{sub 0.04}O{sub 3} (B = Co and Cr) polycrystals. At ambient pressure, the temperature dependence of resistivity [ρ(T)] of both the samples show a first order paramagnetic insulator–ferromagnetic metallic transition at T = T{sub IM}. The application of P on both the samples increases the T{sub IM}, reduces the resistivity, and suppresses the hysteresis width, indicating a crossover from first to second order transition. The critical pressure, where the first–second order crossover takes place, are 2.02 and 2.40 GPa for Co and Cr doped samples respectively. The critical property of both systems around second order transition is investigated using Fisher–Langer relation and Suezaki–Mori method. The estimated critical exponents are close to the three-dimensional Heisenberg model for the Co doped sample suggesting short range interaction, and the exponents for the Cr doped sample follow the mean field theory suggesting long range ferromagnetic order. Further, the application of P suppresses the high temperature resistivity by reducing high temperature polarons in the case of the Cr doped sample, but it does not happen for the Co doped sample. The application of P helps to examine the stability of polarons in the high temperature regime.

  9. Alkali-metal/alkaline-earth-metal fluorine beryllium borate NaSr{sub 3}Be{sub 3}B{sub 3}O{sub 9}F{sub 4} with large nonlinear optical properties in the deep-ultraviolet region

    Energy Technology Data Exchange (ETDEWEB)

    Reshak, A. H., E-mail: maalidph@yahoo.com [New Technologies—Research Centre, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic); Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia); Huang, Hongwei [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Kamarudin, H. [Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia); Auluck, S. [Council of Scientific and Industrial Research—National Physical Laboratory, Dr. K S Krishnan Marg, New Delhi 110012, India and Physics Department, Indian Institute of Technology - Delhi, Hauz Khas, New Delhi 110016 (India)

    2015-02-28

    The linear optical response and second harmonic generation (SHG) in alkali-metal/alkaline-earth-metal fluorine beryllium borate NaSr{sub 3}Be{sub 3}B{sub 3}O{sub 9}F{sub 4} are investigated by means of density functional theory. Calculations are performed using four types of exchange correlations: Ceperley-Alder local density approximation, Perdew Burke and Ernzerhof general gradient approximation, Engel-Vosko generalized gradient approximation, and the recently modified Becke-Johnson potential (mBJ). The mBJ approach brings the calculated band gap (7.20 eV) in excellent agreement with the experimental one (7.28 eV). The calculated values of the uniaxial anisotropy δε=−0.076 and the birefringence Δn(0)=0.052 indicate considerable anisotropy in the linear optical properties, which makes it favorable for the second harmonic generation. The dominant component of the second harmonic generation is χ{sub 111}{sup (2)}(ω). The value of |χ{sub 111}{sup (2)}(ω)| is about 1.2 pm/V at λ = 1064 nm in agreement with previous calculations. To analyze the origin of the high SHG of NaSr{sub 3}Be{sub 3}B{sub 3}O{sub 9}F{sub 4} single crystals, we have correlated the features of |χ{sub 111}{sup (2)}(ω)| spectra with the features of ε{sub 2}(ω) spectra as a function of ω/2 and ω. From the calculated dominant component |χ{sub 111}{sup (2)}(ω)|, we find that the microscopic first hyperpolarizability, β{sub 111}, the vector components along the dipole moment direction is 0.5 × 10{sup −30} esu at static limit and 0.6 × 10{sup −30} esu at λ = 1064 nm.

  10. Study of tau lepton decay into leptons and K{sup 0}{sub L}; Etude des desintegrations du lepton tau en leptons et en K{sup 0}{sub L}

    Energy Technology Data Exchange (ETDEWEB)

    Park, H.J.

    1995-03-21

    In this thesis the {tau} lepton is identified from its decay products and the decay rates into electrons, muons and final states containing K{sub L}{sup 0} (kaons neutral long-lived) are measured. A {tau}{tau} pair is produced in the LEP storage ring from the electron-positron annihilation to a Z{sup 0} boson, e{sup +}e{sup -} {yields} Z{sup 0} {yields} {tau}{sup +}{tau}{sup -}. Each {tau} then decays, {tau} {yields} {nu}{sub {tau}}X where in this thesis only the final states X = e anti{nu}{sub e}, {mu} anti {nu}{sub {mu}}, and {pi}/K({pi}{sup d}eg)K{sub L}{sup 0} are considered. About 62000 {tau}{tau} pairs have been detected by the ALEPH (a detector for LEP physics) period 1991-93 at a center-of-mass energy of about 91 GeV, around the Z{sup 0} boson mass. The total systematic error on the leptonic {tau} decay fractions is 2.9 per mill for B{sub e} and 2.6 per mill for B{sub {mu}}, dominated by Monte Carlo statistics (1.4 per mill), non-{tau} backgrounds (1.4 per mill) and {tau}{tau} selection uncertainty (1.2 per mill). Finally, the following branching ratios are obtained: B{sub e} = (17.79 {+-} 0.13)%, B{sub {mu}} = (17.31 {+-} 0.12)%. These measurements allow to test precisely the e-{mu}-{tau} universality in the charged weak current couplings (Wl anti{nu}{sub l}), g{mu}/g{sub e} = 1.0003 {+-} 0.0051, g{tau}/g{mu} = 0.9979 {+-} 0.0027(world av. {tau}{sub {tau}}) {+-} 0.0023(B{sub l}) {+-} 0.0004(m{tau}) where unity corresponds to perfect e-{mu} and {mu}-{tau} universalities. In addition, a hadronic {tau} final state containing a K{sub L}{sup 0} is studied, which nicely demonstrates the ALEPH capabilities of K{sub L}{sup 0} identification. (authors). 66 refs., 115 figs., 49 tabs.

  11. Luminescence, scintillation, and energy transfer in SiO{sub 2}-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}-Gd{sub 2}O{sub 3}:Ce{sup 3+},Pr{sup 3+} glasses

    Energy Technology Data Exchange (ETDEWEB)

    Lertloypanyachai, Prapon; Chewpraditkul, Weerapong; Pattanaboonmee, Nakarin [Department of Physics, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand); Chen, Danping [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai (China); Babin, Vladimir; Beitlerova, Alena; Nikl, Martin [Institute of Physics, AS CR, Prague (Czech Republic)

    2017-09-15

    Ce{sup 3+},Pr{sup 3+}-codoped SiO{sub 2}-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}-Gd{sub 2}O{sub 3} glasses (SABG:Ce,Pr) were prepared by melt quenching under a CO reducing atmosphere. Luminescence properties were investigated under UV and X-ray excitations. A dominant emission band at 430 nm belonging to the Ce{sup 3+}:5d{sub 1} → 4f transition was observed in the photo- and radio-luminescence spectra. The energy transfer occurs from this Ce{sup 3+} band toward the {sup 3}P{sub J} levels of Pr{sup 3+} with an efficiency of up to 24%, followed by the reduction of integrated luminescence intensity with an increasing Pr{sup 3+} concentration. This result is attributed to the increase in the reabsorption of Ce{sup 3+} luminescence and the non-radiative energy transfer toward the {sup 3}P{sub J} levels of Pr{sup 3+}. The cross-relaxation process within the Pr{sup 3+} pairs can further diminish the total luminescence yield at high Pr{sup 3+} concentrations. The integral scintillation efficiency and light yield measurements were carried out and compared to the reference Bi{sub 4}Ge{sub 3}O{sub 12} (BGO) crystal. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Influence of Co content on the structure and magnetic permeability of nanocrystalline (Fe{sub 1-x}Co{sub x}){sub 73.5}Cu{sub 1}Nb{sub 3}Si{sub 13.5}B{sub 9} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Han Yemei [School of Science, Tianjin University, Tianjin 300072 (China); Wang, Zhi [School of Science, Tianjin University, Tianjin 300072 (China)], E-mail: zhiwang@tju.edu.cn; Che Xianghui; Chen Xuegang; Li Wenrun [School of Science, Tianjin University, Tianjin 300072 (China); Li Yali [Key Laboratory of Advanced Ceramics and Machining Technology (Tianjin University), Ministry of Education, Tianjin 300072 (China)

    2009-01-25

    Structural and soft magnetic response of nanocrystalline (Fe{sub 1-x}Co{sub x}){sub 73.5}Cu{sub 1}Nb{sub 3}Si{sub 13.5}B{sub 9} (x = 0, 0.25, 0.5, 0.75) alloys were investigated. Influences of heat treatment and Co content on the crystallization were analyzed through estimation of the crystalline volume fraction V{sub cr} and thickness of the intergranular amorphous layer {lambda} from XRD patterns. High-temperature soft magnetic response was analyzed by the temperature evolution of the magnetic permeability from room temperature to 780 deg. C. It was found that the high-temperature soft magnetic behavior is improved with increasing Co content for x {<=} 0.5, which is ascribed to reinforcing magnetic coupling between the crystals, however, a decrease of {mu}{sub i} was observed for the Co richest sample. The observed {mu}{sub i} behavior as a function of Co content is interpreted in terms of variations in the degree of exchange coupling.

  13. Ferromagnetic glass ceramics and glass fibers based on the composition of SiO{sub 2}-CaO-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}-Fe{sub 2}O{sub 3} glass system

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jianan, E-mail: lja@qlu.edu.cn; Zhu, Chaofeng; Zhang, Meimei; Zhang, Yanfei; Yang, Xuena

    2017-03-15

    Ferromagnetic glass-ceramics and glass fibers were obtained by the melt-method from the glass system SiO{sub 2}-CaO-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}-Fe{sub 2}O{sub 3} without performing any nucleation and crystallization heat treatments. Glass-ceramics and glass fibers were characterized by x-ray diffraction, scanning and transmission electron microscopy, magnetic measurements, and thermal expansion instrument. The influence of alumina content on the spontaneous crystallization of magnetite, magnetism properties and thermal expansion performances in glass were investigated. We examined the crystallization behavior of the glasses and found that the spontaneous crystallization capacity of magnetite and magnetism properties in base glass increases with increasing the content of alumina. The ferromagnetic glass fibers containing magnetite nano-crystals are also obtained. - Highlights: • Magnetite nano-crystals are formed spontaneously in the investigated glass systems. • The crystallization behavior of the glasses with the alumina content is examined. • Ferromagnetic glass fibers containing magnetite nano-crystals are obtained.

  14. ALD Produced B{sub 2}O{sub 3}, Al{sub 2}O{sub 3} and TiO{sub 2} Coatings on Gd{sub 2}O{sub 3} Burnable Poison Nanoparticles and Carbonaceous TRISO Coating Layers

    Energy Technology Data Exchange (ETDEWEB)

    Weimer, Alan

    2012-11-26

    This project will demonstrate the feasibility of using atomic layer deposition (ALD) to apply ultrathin neutron-absorbing, corrosion-resistant layers consisting of ceramics, metals, or combinations thereof, on particles for enhanced nuclear fuel pellets. Current pellet coating technology utilizes chemical vapor deposition (CVD) in a fluidized bed reactor to deposit thick, porous layers of C (or PyC) and SiC. These graphitic/carbide materials degrade over time owing to fission product bombardment, active oxidation, thermal management issues, and long-term irradiation effects. ALD can be used to deposit potential ceramic barrier materials of interest, including ZrO{sub 2}, Y{sub 2}O{sub 3}:ZrO{sub 2} (YSZ), Al{sub 2}O{sub 3}, and TiO{sub 2}, or neutron-absorbing materials, namely B (in BN or B{sub 2}O{sub 3}) and Gd (in Gd{sub 2}O{sub 3}). This project consists of a two-pronged approach to integrate ALD into the next-generation nuclear plant (NGNP) fuel pellet manufacturing process:

  15. Influence of the microstructure on the magnetic properties of Fe{sub 86}Zr{sub 7}Nb{sub 1}Cu{sub 1}B{sub 5} alloy in the states following solidification and following short-duration annealing below the crystallization temperature

    Energy Technology Data Exchange (ETDEWEB)

    Gondro, Joanna, E-mail: j.gondro@wp.pl

    2017-06-15

    Highlights: • The samples prepared, in the form of ribbons, using a rapid-cooling method. • Amorphous ribbon of the alloy, of nominal composition Fe{sub 86}Zr{sub 7}Nb{sub 1}Cu{sub 1}B{sub 5}. • The amorphous structure was confirmed using XRD, Mössbauer spectroscopy and the microstructure of the specimens were observed with the use of high resolution transmission electron microscopy. • The magnetic properties of the samples were determined by analysis of initial magnetization curves. - Abstract: This paper investigates the influence of heat treatment on the magnetic properties of alloy samples prepared, in the form of ribbons, using a rapid-cooling method. The adopted isothermal annealing processes were found to lead: to the homogenization of the composition, to relaxation of the structure in the amorphous state, and to nanocrystallization. It has been shown that structural relaxation, occurring within the volume of the tested samples, exerts a large influence on the magnetic properties. Observed changes in the distribution of the induction hyperfine field at the {sup 57}Fe nuclei represent direct proof that chemical and topological disorder exists within the volume of the alloy, and the annealing process reduces the internal energy of the entire system. Considering the random anisotropy model for nanocrystalline materials, it can be concluded that the factor that increases, for example, the saturation magnetization is an increase in strength of exchange interactions, which is a measure of the ferromagnetic correlation interactions.

  16. Crystallization of 21.25Gd{sub 2}O{sub 3}-63.75MoO{sub 3}-15B{sub 2}O{sub 3} glass induced by femtosecond laser at the repetition rate of 250 kHz

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, M.J.; Han, Y.M. [Department of Physics, Shanghai University, 99 Shangda Road, Shanghai 200444 (China); Liu, L.P. [Hunan Biological and Electromechanical Polytechnic, Changsha 410126 (China); Zhou, P.; Du, Y.Y.; Guo, Q.T. [Department of Physics, Shanghai University, 99 Shangda Road, Shanghai 200444 (China); Ma, H.L., E-mail: mahl@staff.shu.edu.cn [Department of Physics, Shanghai University, 99 Shangda Road, Shanghai 200444 (China); Dai, Y. [Department of Physics, Shanghai University, 99 Shangda Road, Shanghai 200444 (China)

    2010-12-01

    We report the formation of {beta}'-Gd{sub 2}(MoO{sub 4}){sub 3} (GMO) crystal on the surface of the 21.25Gd{sub 2}O{sub 3}-63.75MoO{sub 3}-15B{sub 2}O{sub 3} glass, induced by 250 kHz, 800 nm femtosecond laser irradiation. The morphology of the modified region in the glass was clearly examined by scanning electron microscopy (SEM). By micro-Raman spectra, the laser-induced crystals were confirmed to be GMO phases and it is found that these crystals have a strong dependence on the number and power of the femtosecond laser pulses. When the irradiation laser power was 900 mW, not only the Raman peaks of GMO crystals but also some new peaks at 214 cm{sup -1}, 240 cm{sup -1}, 466 cm{sup -1}, 664 cm{sup -1} and 994 cm{sup -1}which belong to the MoO{sub 3} crystals were observed. The possible mechanisms are proposed to explain these phenomena.

  17. NO sub 3 , the study of molecular properties and photodissociation by ab initio method, spectroscopy, and translational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, B.

    1990-10-01

    This report discusses the following topics: molecular structure of NO{sub 3} radical studied by laser induced fluorescence; photodissociation and fluorescence spectroscopy of NO{sub 3} in molecular beam; vertical electronic spectrum of NO{sub 3}:{sup 2}A{prime}{sub 2}, {sup 2}E{double prime}({sup 2}A{sub 2}{sup 2}B{sub 1}), and {sup 2}E{prime} states; and Ab initio study of the vibrational spectra of NO{sub 3}.

  18. Study of the influence of the temperature in the magnetic properties and in microstructure in the permanent magnets Pr-Fe-B-Nb-Co based obtained by hydrogen; Estudo da influencia da temperatura nas propriedades magneticas e na microestrutura nos imas permanentes a base de Pr-Fe-B-Nb-Co obtidos com hidrogenio

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Suelanny Carvalho da

    2007-07-01

    Fine magnetic powders were produced using the hydrogenation disproportionation desorption and recombination (HDDR) process. The first stage in this work involved an investigation of the effect of the Co content and range of desorption/ recombination temperatures between 800 and 900 deg C with the purpose of optimizing the HDDR treatment for Pr{sub 14}Fe{sub 80}B{sub 6} and Pr{sub 14}Fe{sub bal}Co{sub x}B{sub 6}Nb{sub 0,1} (x= 0, 4, 8, 10, 12, 16) alloys. The cast alloys were annealed at 1100 deg C for 20 hours for homogenization. The processing temperature (desorption/ recombination) affected the microstructure and magnetic properties of the bonded magnets. The alloy with low cobalt content (4 at.%) required the highest reaction temperature (880 deg C) to yield anisotropic bonded magnets. The optimum temperature for alloys with 8 at.% Co and 10 at.% Co were 840 deg C and 820 deg C, respectively. Alloys with high cobalt content (12 at.% and 16 at.%) were processed at 840 deg C. The optimum desorption temperature for achieving high anisotropy for Pr{sub 14}Fe{sub 80}B{sub 6} and Pr{sub 14}Fe{sub 79,9}B{sub 6}Nb{sub 0,1} was 820 deg C. The best remanence (862 mT) was achieved with the Pr{sub 14}Fe{sub 67,9}B{sub 6}Co{sub 12}Nb{sub 0,1} magnet, processed at 840 deg C. Each alloy required an optimum reaction temperature and exhibited a particular microstructure according to the composition. The second stage of the work involved the characterization, for each temperature, of the Pr{sub 14}Fe{sub 80}B{sub 6} HDDR powder processed using X-ray diffraction analysis. The samples of the HDDR material were studied by synchrotron radiation powder diffraction using the Rietveld method for cell refinement, phase quantification and crystallite sizes determination. Scanning electron microscopy has also been employed to reveal the morphology of the HDDR powder. (author)

  19. Study of hyperfine interactions in intermetallic compounds Gd(Ni,Pd,Cu)In, Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In; Estudo de interacoes hiperfinas em compostos intermetalicos Gd(Ni,Pd,Cu)In, Tb(Ni,Pd)In, Dy(Ni,Pd)In e Ho(Ni,Pd)In

    Energy Technology Data Exchange (ETDEWEB)

    Lapolli, Andre Luis

    2006-07-01

    Systematic behavior of magnetic hyperfine field (B{sub hf}) in the intermetallic compounds Gd(Ni,Pd,Cu)In Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In was studied by Perturbed Gamma-Gamma Angular Correlation spectroscopy. The measurements of B{sub hf} were carried out at the rare earth atom and in sites using the nuclear probes {sup 140}Ce and {sup 11}'1Cd respectively. The variation of hyperfine field with temperature, in most cases, follows the Brillouin function predicted from the molecular field theory. The hyperfine field values at rare earth atom sites obtained from {sup 140}Ce probe as well as at in sites obtained from {sup 111}Cd probe for each series of compounds were extrapolated to zero Kelvin B{sub hf}(T=0) from these curves. These values were compared with the values of the literature for other compounds containing the same rare earth element and all of them show a linear relationship with the ordering temperature. This indicates that the main contribution to B{sub hf} comes from the conduction electron polarization (CEP) through Fermi contact interaction and the principal mechanism of magnetic interaction in these compounds can be described by the RKKY type interaction. The values of B{sub hf}(T=0) for each family of intermetallic compounds RNiIn and RPdIn when plotted as a function of 4f spin projection of rare earth element also shows a linear relationship. Exceptions are the results for the compounds RNiIn obtained with {sup 111}Cd probe where a small deviation from linearity is observed. The results of the measurements carried out with the {sup 111}Cd probe were also analyzed to obtain the hyperfine parameters of the quadrupole interaction as a function of temperature for RPdln and GdNiIn compounds. The results show that for the compound GdPdIn there might be some Gd-In disorder at high temperature. (author)

  20. Excited state non-adiabatic dynamics of pyrrole: A time-resolved photoelectron spectroscopy and quantum dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Guorong [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada); State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Neville, Simon P.; Worth, Graham A., E-mail: g.a.worth@bham.ac.uk [School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Schalk, Oliver [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada); Department of Physics, AlbaNova University Center, Stockholm University, Roslagstullsbacken 21, 109 61 Stockholm (Sweden); Sekikawa, Taro [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada); Department of Applied Physics, Hokkaido University, Kita-13 Nishi-8, Kita-ku, Sapporo 060-8628 (Japan); Ashfold, Michael N. R. [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Stolow, Albert, E-mail: astolow@uottawa.ca [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada); Departments of Chemistry and Physics, University of Ottawa, 10 Marie Curie, Ottawa, Ontario K1N 6N5 (Canada)

    2015-02-21

    The dynamics of pyrrole excited at wavelengths in the range 242-217 nm are studied using a combination of time-resolved photoelectron spectroscopy and wavepacket propagations performed using the multi-configurational time-dependent Hartree method. Excitation close to the origin of pyrrole’s electronic spectrum, at 242 and 236 nm, is found to result in an ultrafast decay of the system from the ionization window on a single timescale of less than 20 fs. This behaviour is explained fully by assuming the system to be excited to the A{sub 2}(πσ{sup ∗}) state, in accord with previous experimental and theoretical studies. Excitation at shorter wavelengths has previously been assumed to result predominantly in population of the bright A{sub 1}(ππ{sup ∗}) and B{sub 2}(ππ{sup ∗}) states. We here present time-resolved photoelectron spectra at a pump wavelength of 217 nm alongside detailed quantum dynamics calculations that, together with a recent reinterpretation of pyrrole’s electronic spectrum [S. P. Neville and G. A. Worth, J. Chem. Phys. 140, 034317 (2014)], suggest that population of the B{sub 1}(πσ{sup ∗}) state (hitherto assumed to be optically dark) may occur directly when pyrrole is excited at energies in the near UV part of its electronic spectrum. The B{sub 1}(πσ{sup ∗}) state is found to decay on a timescale of less than 20 fs by both N-H dissociation and internal conversion to the A{sub 2}(πσ{sup ∗}) state.

  1. Uranyl complexes formed with a para-t-butylcalix[4]arene bearing phosphinoyl pendant arms on the lower rim. Solid and solution studies

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, F. de M. [Instituto Nacional de Investigaciones Nucleares, La Marquesa, Ocoyoacac (Mexico). Dept. de Quimica; Varbanov, S. [Bulgarian Academy of Sciences, Sofia (Bulgaria). Inst. of Organic Chemistry with Center of Phytochemistry; Buenzli, J.C.G. [Ecole Polytechnique Federale de Lausanne (EPFL) (Switzerland). Inst. of Chemical Sciences and Engineering; Rivas-Silva, J.F.; Ocana-Bribiesca, M.A. [Instituto de Fisica de la BUAP, Puebla (Mexico); Cortes-Jacome, M.A.; Toledo-Antonio, J.A. [Instituto Mexicano del Petroleo/Programa de Ingenieria Molecular (Mexico)

    2012-07-01

    The current interest in functionalized calixarenes with phosphorylated pendant arms resides in their coordination ability towards f elements and capability towards actinide/rare earth separation. Uranyl cation forms 1:1 and 1:2 (M:L) complexes with a tetra-phosphinoylated p-tert-butylcalix[4]arene, B{sub 4}bL{sup 4}: UO{sub 2}(NO{sub 3}){sub 2}(B{sub 4}bL{sup 4}){sub n} . xH{sub 2}O (n = 1, x = 2, 1; n = 2, x = 6, 2). Spectroscopic data point to the inner coordination sphere of 1 containing one monodentate nitrate anion, one water molecule and the four phosphinoylated arms bound to UO{sub 2}{sup 2+} while in 2, uranyl is only coordinated to calixarene ligands. In both cases the U(VI) ion is 8-coordinate. Uranyl complexes display enhanced metal-centred luminescence due to energy transfer from the calixarene ligands; the luminescence decays are bi-exponential with associated lifetimes in the ranges 220 {mu}s < {tau}{sub s} < 250 {mu}s and 630 {mu}s < {tau}{sub L} < 640 {mu}s, pointing to the presence of two species with differently coordinated calixarene, as substantiated by a XPS study of U(4f{sub 5/2,7/2}), O(1s) and P(2p) levels on solid state samples. The extraction study of UO{sub 2}{sup 2+} cation and trivalent rare-earth (Y, La, Eu) ions from acidic nitrate media by B{sub 4}bL{sup 4} in chloroform shows the uranyl cation being much more extracted than rare earths. (orig.)

  2. Magnetostrictive behaviour of Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3-x}Mo{sub x}Cu{sub 1} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Silveyra, J.M. [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, UBA-CONICET, Paseo Colon 850, C1063ACV Buenos Aires (Argentina); Cremaschi, V.J., E-mail: vcremas@gmail.co [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, UBA-CONICET, Paseo Colon 850, C1063ACV Buenos Aires (Argentina); Member of Carrera del Investigador, CONICET (Argentina); Vlasak, G.; Illekova, E.; Janickovic, D.; Svec, P. [Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 845 11 Bratislava (Slovakia)

    2010-08-15

    Magnetostriction, dilatation and calorimetric measurements were performed on FINEMET type as-quenched and heat treated ribbons. Nb was gradually replaced by Mo in order to study the influence of the refractory elements exchange on several magnetostriction parameters. The results could be correlated with magnetic and structural transformations throughout thermal treatments and assured that the whole series is suitable for technical applications.

  3. Effect of holding time on microstructure and mechanical properties of SiC/SiC joints brazed by Ag-Cu-Ti + B>4C composite filler

    OpenAIRE

    Dai, Xiangyu; Cao, Jian; Tian, Yingtao; Chen, Zhe; Song, Xiaoguo; Feng, Jicai

    2016-01-01

    The composite fillers have a number of advantages comparing with the traditional filler metals, and have been widely used for brazing ceramics. However, previous researches mainly focus on the strengthening mechanism of either whiskers or particles. It is still of great interest to investigate the reinforcement effect with the presence of both whiskers and particles. In this study, Ag-Cu-Ti + B4C composite filler was developed to braze SiC ceramics, and effects of holding time on the microstr...

  4. Luminescence and thermoluminescence of Sr{sub 2}B{sub 5}O{sub 9}X:Ce{sup 3+},A{sup +} (X = Cl, Br, A = Na{sup +}, K{sup +}) phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Sidorenko, A V [Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Bos, A J J [Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Dorenbos, P [Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Rodnyi, P A [St Petersburg State Technical University, Polytekhnicheskaya 29, 195251 St Petersburg (Russian Federation); Eijk, C W E van [Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Berezovskaya, I V [A V Bogatsky Physico-Chemical Institute, Ukranian Academy of Science, 65080 Odessa (Ukraine); Dotsenko, V P [A V Bogatsky Physico-Chemical Institute, Ukranian Academy of Science, 65080 Odessa (Ukraine)

    2003-05-28

    The luminescence properties of Ce{sup 3+} activated strontium haloborates with and without K{sup +} or Na{sup +} co-doping have been studied under optical and x-ray excitation. Three types of Ce{sup 3+} emission centre have been found as the result of different methods of charge compensation in non-co-doped samples. In the co-doped compounds only one type of Ce{sup 3+} emission centre has been observed. The influence of Ce{sup 3+} concentration, anion type and co-doping ion on thermoluminescence (TL) has been analysed. The TL glow curves of all the studied materials contain two peaks. The emission corresponding to the low temperature peak is associated with charge uncompensated Ce{sup 3+} centres in non-co-doped compounds. The emission of the high temperature peak represents the superposition of both charge compensated and uncompensated Ce{sup 3+} centres. The emission corresponding to both TL peaks in co-doped samples originates from one type of Ce{sup 3+} centre.

  5. High-resolution T{sub 2}-weighted cervical cancer imaging: a feasibility study on ultra-high-field 7.0-T MRI with an endorectal monopole antenna

    Energy Technology Data Exchange (ETDEWEB)

    Hoogendam, Jacob P.; Verheijen, Rene H.M.; Zweemer, Ronald P. [University Medical Centre Utrecht, Department of Gynaecological Oncology, UMC Utrecht Cancer Centre, PO Box 85500, Utrecht (Netherlands); Kalleveen, Irene M.L.; Castro, Catalina S.A. de; Raaijmakers, Alexander J.E.; Bosch, Maurice A.A.J. van den; Klomp, Dennis W.J.; Veldhuis, Wouter B. [University Medical Centre Utrecht, Department of Radiology, Utrecht (Netherlands)

    2017-03-15

    We studied the feasibility of high-resolution T{sub 2}-weighted cervical cancer imaging on an ultra-high-field 7.0-T magnetic resonance imaging (MRI) system using an endorectal antenna of 4.7-mm thickness. A feasibility study on 20 stage IB1-IIB cervical cancer patients was conducted. All underwent pre-treatment 1.5-T MRI. At 7.0-T MRI, an external transmit/receive array with seven dipole antennae and a single endorectal monopole receive antenna were used. Discomfort levels were assessed. Following individualised phase-based B{sub 1} {sup +} shimming, T{sub 2}-weighted turbo spin echo sequences were completed. Patients had stage IB1 (n = 9), IB2 (n = 4), IIA1 (n = 1) or IIB (n = 6) cervical cancer. Discomfort (ten-point scale) was minimal at placement and removal of the endorectal antenna with a median score of 1 (range, 0-5) and 0 (range, 0-2) respectively. Its use did not result in adverse events or pre-term session discontinuation. To demonstrate feasibility, T{sub 2}-weighted acquisitions from 7.0-T MRI are presented in comparison to 1.5-T MRI. Artefacts on 7.0-T MRI were due to motion, locally destructive B{sub 1} interference, excessive B{sub 1} under the external antennae and SENSE reconstruction. High-resolution T{sub 2}-weighted 7.0-T MRI of stage IB1-IIB cervical cancer is feasible. The addition of an endorectal antenna is well tolerated by patients. (orig.)

  6. Study of the influence of zirconium and gallium on the magnetic properties and microstructures of praseodymium-based permanent magnets; Estudo da influencia do zirconio e galio nas propriedades magneticas e na microestrutura dos imas permanentes a base de praseodimio

    Energy Technology Data Exchange (ETDEWEB)

    Fusco, Alexandre Giardini

    2006-07-01

    In this work was studied the influence of the addition of 0.5 at. % of zirconium and gallium on praseodymium-based HD sintered magnets obtained using a mixture of alloys. The alloys used in this study were: Pr{sub 12.6}Fe{sub 68.3}Co{sub 11.6}B{sub 6}Zr{sub 0.5}Ga{sub 1}, Pr{sub 16}Fe{sub 75.5}B{sub 8}Zr{sub 0.5}, Pr{sub 13}Fe{sub 80.5}B{sub 6}Zr{sub 0.5}. The investigation started by measuring the magnetic properties and observing the microstructure of the magnets. After that, the magnets were annealed at 1000 deg C for 2 hours followed by rapid cooling, in a total of 10 hours. This heat treatment was followed by 5 hours at the same temperature up to a total of 35 hours. Changes in the microstructure were compared to the change in the magnetic properties aiming at a proper understanding of the role of each added element in relation to the magnetically hard phase (phase {phi}). It has been shown that gallium and zirconium act as grain refiners of the matrix phase {phi}. Gallium acts in the grain and favoring of the shape stability and improvement of the magnetic properties. For the Pr{sub 14.3}Fe{sub 71.9}Co{sub 5.8}B{sub 7}Zr{sub 0.5}Ga{sub 0.5} sintered magnet the evolution of the magnetic properties after 15 hours heat treatment was: remanence from (1.25{+-}0.02) T to (1.30{+-}0.02) T, intrinsic coercivity from (1.11{+-}0.02) T to (0.87{+-}0.02) T, squareness factor from (0.68{+-}0.02) to (0.82{+-}0.02) and energy product from (285{+-}5) kJ/m{sup 3} to (317{+-}5) kJ/m{sup 3}. Zirconium has two effects on the sintered magnets. Firstly, avoiding random grain growth and enhancing anisotropy. However, by concentrating on the grain boundaries, yield reverse domains and is detrimental to the intrinsic coercivity. For the sintered Pr{sub 14.5}Fe{sub 78}B{sub 7}Zr{sub 0.5} magnet the evolution of the magnetic properties achieved after a heat treatment of 15 hours was: remanence from (1.19{+-}0.02) T to (1.25{+-}0.02) T, coercivity from (0.74{+-}0.02) T to (0

  7. Spin echo and nuclear orientation study of metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Pavlovsky, J.; Rotter, M.; Sedlak, B.; Lestak, L.; Bartos, M.; Prochazka, I.; Finger, M.

    Hyperfine fields on Co nuclei in amorphous as-quenched and heat-treated Co/sub 75/Fe/sub 5/B/sub 20/ samples were studied by conventional NMR and by very low temperature nuclear orientation techniques. The /sup 59/Co spin echo measurement at 1.4 K yielded broad spectra between 130 - 260 MHz, with narrow maxima at 145.5 MHz and 155.1 MHz for as-quenched sample and with a broad maximum at 227 MHz for heat-treated sample well below the recrystallization point. The /sup 60/Co nuclear orientation measurements gave the mean value of the hyperfine field 15 T nearly independent of the sample heat-treatment. The spin-lattice relaxation was studied by pulse NMR and also by nuclear orientation thermal cycling technique.

  8. DSC and optical studies on BaO-Li{sub 2}O-B{sub 2}O{sub 3}-CuO glass system

    Energy Technology Data Exchange (ETDEWEB)

    Bhogi, Ashok, E-mail: ashokbhogi@gmail.com; Kumar, R. Vijaya [School of Physics, University of Hyderabad, Hyderabad, Telangana, India. (India); Ahmmad, Shaik Kareem [Department of Physics, Muffakham Jah College of Engineering and Technology, Hyderabad, Telangana, India. (India); Kistaiah, P. [Department of Physics, Osmania University, Hyderabad, Telangana, India. (India)

    2016-05-06

    Glasses with composition 15BaO-25Li{sub 2}O-(60-x)B{sub 2}O{sub 3} -xCuO (x= 0, 0.2, 0.4, 0.6, 0.8 and 1 mol%) were prepared by the conventional melt quenching technique. These glasses were characterized using X-ray diffraction (XRD), differential scanning calorimetry (DSC) and density measurements. Optical absorption studies were carried out as a function of copper ion concentration. The optical absorption spectra of studied glasses containing copper oxide exhibit a single broad band around 761nm which has been assigned to the 2B{sub 1g}→2B{sub 2g} transition. From these studies, the variations in the values of glass transition temperature (T{sub g}) have been observed. The fundamental absorption edge has been determined from the optical absorption spectra. The values of optical band gap and Urbach energy were determined with increase in concentration of CuO. The variations in density, glass transition temperature, optical band gap and Urbach energy with CuO content have been discussed in terms of changes in the glass structure. The analysis of these results indicated that copper ions mostly exist in Cu{sup 2+} state in these glasses when the concentration of CuO ≤ 0.8 mol% and above this concentration copper ions seem to subsist in Cu{sup 1+} state.

  9. New structural studies of liquid crystal by reflectivity and resonant X-ray diffraction; Nouvelles etudes structurales de cristaux liquides par reflectivite et diffraction resonante des rayons X

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, P

    2007-04-15

    This memory presents three structural studies of smectic Liquid Crystals by reflectivity and resonant diffraction of X-rays. It is divided in five chapters. In the first a short introduction to Liquid Crystals is given. In particular, the smectic phases that are the object of this study are presented. The second chapter is consecrated to the X-ray experimental techniques that were used in this work. The three last chapters present the works on which this thesis can be divided. Chapter three demonstrates on free-standing films of MHPOBC (historic liquid crystal that possesses the antiferroelectric sub-phases) the possibility to extend the technique of resonant X-ray diffraction to liquid crystals without resonant element. In the fourth chapter the structure of the B{sub 2} liquid crystal phase of bent-core molecules (or banana molecules) is elucidated by using resonant X-ray diffraction combined with polarization analysis of the diffracted beam. A model of the polarization of the resonant beam diffracted by four different structures proposed for the B{sub 2} phase is developed in this chapter. In the fifth chapter a smectic binary mixture presenting a very original critical point of phase separation is studied by X-ray reflectivity and optical microscopy. A concentration gradient in the direction perpendicular to the plane of the film seems to be induced by the free-standing film geometry. The results of a simplified model of the system are compatible with this interpretation.

  10. Structural and magnetic study of Mo-doped FINEMET

    Energy Technology Data Exchange (ETDEWEB)

    Silveyra, J.M., E-mail: jsilveyra@fi.uba.a [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires-CONICET, Paseo Colon 850, (C1063ACV) Buenos Aires (Argentina); Cremaschi, V.J. [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires-CONICET, Paseo Colon 850, (C1063ACV) Buenos Aires (Argentina); Miembro de la Carrera del Investigador del CONICET (Argentina); Janickovic, D.; Svec, P. [Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 845 11 Bratislava (Slovakia); Arcondo, B. [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires-CONICET, Paseo Colon 850, (C1063ACV) Buenos Aires (Argentina)

    2011-02-15

    In this paper, a study of the structural and the magnetic correlation of the crystalline and amorphous phases in the nanocrystalline system Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3-x}Mo{sub x}Cu{sub 1} (x=0, 1.5, 2, 3) was made. By means of Moessbauer spectroscopy, simple mass balance considerations and density measurements, both phases fractions and chemical compositions were calculated (in at%, wt% and vol%). Then, quasistatic magnetic measurements and ab initio calculations were used in a magnetic balance model in order to estimate the magnetic contribution of the remaining amorphous phase, which was compared to that of as-quenched amorphous samples of the same composition. The difference in both magnitudes showed the influence of penetrating fields and that these became more important for higher crystalline fractions.

  11. B0(s) mixing studies at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Naimuddin, M.D.; /Delhi U.

    2006-05-01

    Measurement of the B{sub s}{sup 0} oscillation frequency via B{sub s}{sup 0} mixing analysis provides a powerful constraint on CKM matrix elements. This note briefly reviews the motivation behind these analyses and describes the various steps that go into a mixing measurement. Recent results on B{sub s}{sup 0} mixing obtained by the CDF and D0 collaborations using the data samples collected at Tevatron Collider in the period 2002-2005 are presented.

  12. Electronic structure, elasticity, bonding features and mechanical behaviour of zinc intermetallics: A DFT study

    Energy Technology Data Exchange (ETDEWEB)

    Fatima, Bushra, E-mail: bushrafatima25@gmail.com; Acharya, Nikita; Sanyal, Sankar P. [Department of Physics, Barkatullah University, Bhopal, 462026 (India)

    2016-05-06

    The structural stability, electronic structure, elastic and mechanical properties of TiZn and ZrZn intermetallics have been studied using ab-initio full potential linearized augmented plane wave (FP-LAPW) method within generalized gradient approximation for exchange and correlation potentials. The various structural parameters, such as lattice constant (a{sub 0}), bulk modulus (B), and its pressure derivative (B’) are analysed and compared. The investigation of elastic constants affirm that both TiZn and ZrZn are elastically stable in CsCl (B{sub 2} phase) structure. The electronic structures have been analysed quantitatively from the band structure which reveals the metallic nature of these compounds. To better illustrate the nature of bonding and charge transfer, we have also studied the Fermi surfaces. The three well known criterion of ductility namely Pugh’s rule, Cauchy’s pressure and Frantsevich rule elucidate the ductile nature of these compounds.

  13. High flux expansion divertor studies in NSTX

    Energy Technology Data Exchange (ETDEWEB)

    Soukhanovskii, V A; Maingi, R; Bell, R E; Gates, D A; Kaita, R; Kugel, H W; LeBlanc, B P; Maqueda, R; Menard, J E; Mueller, D; Paul, S F; Raman, R; Roquemore, A L

    2009-06-29

    Projections for high-performance H-mode scenarios in spherical torus (ST)-based devices assume low electron collisionality for increased efficiency of the neutral beam current drive. At lower collisionality (lower density), the mitigation techniques based on induced divertor volumetric power and momentum losses may not be capable of reducing heat and material erosion to acceptable levels in a compact ST divertor. Divertor geometry can also be used to reduce high peak heat and particle fluxes by flaring a scrape-off layer (SOL) flux tube at the divertor plate, and by optimizing the angle at which the flux tube intersects the divertor plate, or reduce heat flow to the divertor by increasing the length of the flux tube. The recently proposed advanced divertor concepts [1, 2] take advantage of these geometry effects. In a high triangularity ST plasma configuration, the magnetic flux expansion at the divertor strike point (SP) is inherently high, leading to a reduction of heat and particle fluxes and a facilitated access to the outer SP detachment, as has been demonstrated recently in NSTX [3]. The natural synergy of the highly-shaped high-performance ST plasmas with beneficial divertor properties motivated a further systematic study of the high flux expansion divertor. The National Spherical Torus Experiment (NSTX) is a mid-sized device with the aspect ratio A = 1.3-1.5 [4]. In NSTX, the graphite tile divertor has an open horizontal plate geometry. The divertor magnetic configuration geometry was systematically changed in an experiment by either (1) changing the distance between the lower divertor X-point and the divertor plate (X-point height h{sub X}), or by (2) keeping the X-point height constant and increasing the outer SP radius. An initial analysis of the former experiment is presented below. Since in the divertor the poloidal field B{sub {theta}} strength is proportional to h{sub X}, the X-point height variation changed the divertor plasma wetted area due to

  14. Study of a new glass matrix by the thermoluminescence technique; Estudo de uma nova matriz vitrea pela tecnica de termoluminescencia

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Pamela Z.; Vedovato, Uly P.; Cunha, Diego M. da; Dantas, Noelio O.; Silva, Anielle C.A.; Neves, Lucio P.; Perini, Ana P., E-mail: anapaula.perini@ufu.br [Universidade Federal de Uberlandia (INFIS/UFU), MG (Brazil). Instituto de Fisica; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Carrera, Betzabel N.S.; Watanabe, Shigueo [Universidade de Sao Paulo (IF/USP), Sao Paulo, SP (Brazil). Instituto de Fisica

    2015-07-01

    The thermoluminescence technique is widely used for both personal and for high-dose dosimetry. In this work, the thermoluminescence technique was utilized to study a new glass matrix, with nominal composition of 20Li{sub 2}CO{sub 3}.10Al{sub 2}O{sub 3}.20BaO.50B{sub 2}O{sub 3} (mol%), irradiated with different doses in a {sup 60}Co source. The glow curves and the dose-response curve were obtained for radiation doses between 50 Gy and 900 Gy. The results showed that this new glass matrix presents potential use in high-dose dosimetry. (author)

  15. Study of Cs adsorption on (100) surface of [001]-oriented GaN nanowires: A first principle research

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Sihao [Department of Optoelectronic Technology, School of Electronic and Optical Engineering, Nanjing University of Science and Technology Nanjing, 210094 (China); Liu, Lei, E-mail: liu1133_cn@sina.com.cn [Department of Optoelectronic Technology, School of Electronic and Optical Engineering, Nanjing University of Science and Technology Nanjing, 210094 (China); Kong, Yike [Department of Optoelectronic Technology, School of Electronic and Optical Engineering, Nanjing University of Science and Technology Nanjing, 210094 (China); Wang, Honggang; Wang, Meishan [School of Information and Electrical Engineering, Ludong University, Yantai 264025 (China)

    2016-11-30

    Highlights: • B{sub N} is the most stable adsorption site. • Work function is reduced after Cs adsorption. • Surface atomic structures are reconstructed. • Surface states near fermi level is contributed to the hybridization of Cs 5s state with Ga 4p and N 2p state. • NEA surface is demonstrated after Cs adsorption on GaN nanowire surface. - Abstract: Based on first-principle study, the adsorption mechanism of Cs on (100) crystal plane of GaN nanowire surface with coverage of 1/12 monolayer is explored. It is discovered that the most stable adsorption site is B{sub N} because of its lowest adsorption energy. The work function of GaN nanowire surface is reduced by 1.69 eV and will be further reduced with increasing Cs adsorption, which promotes the development of negative electron affinity (NEA) state of the materials. Furthermore, Cs adatom will make a great influence on the surface atomic structure, oppositely, little influence on the center atomic structure. There appears a dipole moment valued −6.93 Debye on the nanowire surface contributed to the formation the heterojunction on the surface, which is beneficial to the photoelectrons liberation. After Cs adsorption, the valence band and conduction band both move to lower energy side. The surface states mainly result from the hybridization of Cs 5s state with Ga 4p state and N 2p state. This study can help us to further experiment on the Cs adsorption processing on GaN nanowire and improve the photoemission performance of GaN nanowire devices.

  16. Structural phase transition of ternary dielectric SmGdO{sub 3}: Evidence from angle dispersive x-ray diffraction and Raman spectroscopic studies

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Yogesh, E-mail: rkatiyar@uprrp.edu, E-mail: satya504@gmail.com, E-mail: yogesh.sharma@upr.edu; Sahoo, Satyaprakash, E-mail: rkatiyar@uprrp.edu, E-mail: satya504@gmail.com, E-mail: yogesh.sharma@upr.edu; Misra, Pankaj; Pavunny, Shojan P.; Katiyar, Ram S., E-mail: rkatiyar@uprrp.edu, E-mail: satya504@gmail.com, E-mail: yogesh.sharma@upr.edu [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, San Juan, Puerto Rico 00936-8377 (United States); Mishra, A. K.; Dwivedi, Abhilash; Sharma, S. M. [High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai (India)

    2015-03-07

    High-pressure synchrotron based angle dispersive x-ray diffraction (ADXRD) studies were carried out on SmGdO{sub 3} (SGO) up to 25.7 GPa at room temperature. ADXRD results indicated a reversible pressure-induced phase transition from ambient monoclinic to hexagonal phase at ∼8.9 GPa. The observed pressure-volume data were fitted with the third order Birch-Murnaghan equation of state yielding zero pressure bulk modulus B{sub 0} = 132(22) and 177(9) GPa for monoclinic (B-type) and hexagonal (A-type) phases, respectively. Pressure dependent micro-Raman spectroscopy further confirmed the monoclinic to hexagonal phase transition at about 5.24 GPa. The mode Grüneisen parameters and pressure coefficients for different Raman modes corresponding to each individual phases of SGO were calculated using pressure dependent Raman mode analysis.

  17. Kinetics of crystallization in FeB based nanocrystalline soft magnetic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini-Nasab, Farzad, E-mail: f.hosseininasab@modares.ac.ir [Department of Nanotechnology, Faculty of Engineering, Tarbiat Modares University, P. O. Box 14115-143, Tehran 1411713116 (Iran, Islamic Republic of); Tavakoli, Mohammad Mahdi, E-mail: m.tavakoli@modares.ac.ir [Department of Nanotechnology, Faculty of Engineering, Tarbiat Modares University, P. O. Box 14115-143, Tehran 1411713116 (Iran, Islamic Republic of); Beitollahi, Ali, E-mail: beitolla@iust.ac.ir [School of Metallurgy and Materials Engineering, Iran Universities of Science and Technology, Tehran 1684613114 (Iran, Islamic Republic of); Moravvej-Farshi, Mohammad Kazem, E-mail: farshi_k@modares.ac.ir [Faculty of Electrical and Computer Engineering, Tarbiat Modares University, Tehran 1411713116 (Iran, Islamic Republic of)

    2016-06-01

    An attempt is made to study the effect of substituting Si and Cu atoms for B in Fe{sub 84}B{sub 16} alloys on the microstructure and magnetic properties of the resulting melt spun compositions (i.e., Fe{sub 84}B{sub 14}Si{sub 2} and Fe{sub 84}B{sub 12}Si{sub 3.3}Cu{sub 0.7}). As-spun and annealed samples were characterized by various techniques to investigate their crystallization kinetics and the magnetic properties of the resulting microstructures. Experiments have revealed that Fe{sub 84}B{sub 12}Si{sub 3.3}Cu{sub 0.7} composition exhibits the optimum magnetic properties of M{sub S}=1.92 T and H{sub C}=11 A/m among the three samples under study. - Highlights: • Grains’ size in annealed Fe{sub 8}4B{sub 14}Si{sub 2} is ~20% smaller than those in Fe{sub 8}4B{sub 16}. Primary activation energy of Fe{sub 8}4B{sub 14}Si{sub 2} is 36% lower than that of Fe{sub 8}4B{sub 16}. Secondary activation energy of Fe{sub 8}4B{sub 14}Si{sub 2} is 8% higher than that of Fe{sub 8}4B{sub 16}. • Grains’ size in annealed Fe{sub 8}4B{sub 12}Si{sub 3.3}Cu{sub 0.7} is ~60% smaller than those in Fe{sub 8}4B{sub 16}. Primary activation energy of Fe{sub 8}4B{sub 12}Si{sub 3.3}Cu{sub 0.7} is 48% lower than that of Fe{sub 8}4B{sub 16}. Secondary activation energy of Fe{sub 8}4B{sub 12}Si{sub 3.3}Cu{sub 0.7} is 57% higher than that of Fe{sub 8}4B{sub 16}. • Fine microstructures formed in Fe{sub 8}4B{sub 12}Si{sub 3.3}Cu{sub 0.7} has led to M{sub s}=1.92 T and H{sub c}=11 A/m.

  18. B^0_s Oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Casarsa, Massimo; /Fermilab

    2007-12-01

    For a long time the B{sub s}{sup 0}-{bar B}{sub s}{sup 0} system has eluded a complete investigation of its observables. Only recently the Tevatron experiments have accumulated sizable B{sub s}{sup 0} samples, which allow a direct and precise study of the system properties. This contribution reviews the most up-to-date measurements by the CDF and D0 Collaborations of the B{sub s}{sup 0}-{bar B}{sub s}{sup 0} system parameters: the mass and decay width differences, {Delta}m{sub s} and {Delta}{Lambda}{sub s}, between the heavy and light B{sub s}{sup 0} mass eigenstates, the average decay width {Lambda}{sub s}, and the CP-violating phase in the mixing {phi}{sub s}.

  19. REFINEMENT OF THE NEPHELINE DISCRIMINATOR: RESULTS OF A PHASE I STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K; James Newell, J; Tommy Edwards, T; David Best, D; Irene Reamer, I; Phyllis Workman, P

    2008-02-13

    studied HLW glasses with relatively high Al{sub 2}O{sub 3} compositions of 25 wt % or greater and nepheline discriminator values well below 0.62 have been shown to be free of nepheline crystallization upon quenching and slow cooling. Thus, the current nepheline discriminator equation also appears to be conservative for some HLW glass compositions. Refining the nepheline discriminator to include other important components and to reduce conservatism may provide access to high Al{sub 2}O{sub 3} concentration glass compositions for the DWPF, which could in turn allow access to higher waste loadings, decreased washing and improved waste throughput. The objective of this study was to develop and characterize a series of HLW glass compositions based on a projected composition of Sludge Batch 5 (SB5), the next sludge batch to be processed in the DWPF. The selected glass compositions all had nepheline discriminator values below the current limit of 0.62. They cover a range of locations on the SiO{sub 2}-Na{sub 2}O-Al{sub 2}O{sub 3} diagram. They also include varying amounts of B{sub 2}O{sub 3} and CaO to support an evaluation of the impact of these components on the propensity for nepheline crystallization. The results described in this report confirm that some conservatism exists in the current nepheline discriminator. Several glass compositions, particularly compositions that target higher Al{sub 2}O{sub 3} concentrations, were shown to be very durable (i.e., PCT responses that were more than an order of magnitude better than that of the Environmental Assessment benchmark glass) while their nepheline discriminator values were well below the current nepheline discriminator limit of 0.62. Increased concentrations of B{sub 2}O{sub 3} and increased concentrations of CaO were shown to improve durability responses and suppress the formation of nepheline. This provides incentive to revise the nepheline discriminator to reduce some of this conservatism and incorporate the influence of B{sub

  20. Synthesis and studies on microhardness of alkali zinc borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Subhashini,, E-mail: subhashini.p.p@gmail.com; Bhattacharya, Soumalya, E-mail: subhashini.p.p@gmail.com; Shashikala, H. D., E-mail: subhashini.p.p@gmail.com; Udayashankar, N. K., E-mail: subhashini.p.p@gmail.com [Department of Physics, National Institute of Technology Karnataka, Surathkal-575025 (India)

    2014-04-24

    The mixed alkali effect on zinc borate glasses have been reported. The glass systems of nominal composition 10Zn+xLi{sub 2}O+yNa{sub 2}O+80B{sub 2}O{sub 3} (x = y = 0, 5, 10, 15 mol%) were prepared using standard melt quenching method. The structural, physical and mechanical properties of the samples have been studied using X-ray diffraction(XRD), density measurement and Vickers hardness measurement, respectively. A consistent increase in the density was observed, which explains the role of the modifiers (Li{sub 2}O and Na{sub 2}O) in the network modification of borate structure. The molar volume is decreasing linearly with the alkali concentration, which is attributed to the conversion of tetrahedral boron (BO{sub 4/2}){sup −} into (BO{sub 3/2}){sup −}. The microhardness studies reveals the anisotropy nature of the material. It further confirms that the samples belong to hard glass category.

  1. Spectroscopic study of neodymium doped lead-bismuth-borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Pasha, Altaf; Dayani, P.; Negalur, Mahesh; Swamy, Manjunatha; Abhiram, J. [Dept of Post Graduate Studies & Research in Physics, The National Degree College, Bangalore (India); Rajaramakrishna, R. [Dept of Post Graduate Studies & Research in Physics, The National Degree College, Bangalore (India); Physics Department, Bangalore University, Bangalore (India)

    2016-05-06

    This paper reports on different physical and optical properties of rare earth doped heavy metal oxide glasses. The glass composition of 10Bi{sub 2}O{sub 3}-30PbO-60B{sub 2}O{sub 3}-xNd{sub 2}O{sub 3} where x = 0, 0.1, 0.2, 0.5 and 1 (in mol %) has been synthesized using melt-quenching technique. Refractive index measurements for these glasses were done and physical parameters were studied. Structural properties of these glasses were analysed through infrared spectra that was recorded between 1600cm{sup −1} and 300cm{sup −1} in transmission mode. The optical absorption spectra were recorded in the wavelength range from 300 to 700 nm. The transitions originated from ground state energy {sup 4}I{sub 9/2}. The energy level analysis has been carried out by considering absorption spectral bands. The results thus obtained are comparable with reports on similar glasses, indicating that the prepared glasses may have potential laser applications.

  2. Characterization and study of dielectric and electrical properties of CaBi4Ti4O{sub 15} (CBT) added with Bi{sub 2}O{sub 3}; Caracterizacao e estudo das propriedades eletricas e dieletricas do CaBi{sub 4}Ti{sub 4}O{sub 15} (CBT) adicionado com Bi{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, D.B.; Campos Filho, M.C.; Sales, J.C.; Silva, P.M.O.; Sombra, A.S. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil)

    2011-07-01

    The ceramic perovskite CaBi{sub 4}Ti{sub 4}O{sub 15} (CBT) of space group A21am, Aurivillius family with deficiency A{sub 5}B{sub 4}O{sub 15} cation has been prepared by solid state method in a planetary ball mill of high energy. The reagents samples were ground and calcined and then added with Bi{sub 2}O{sub 3} (2% wt.) This work aims to characterize by X-ray diffraction to study the electrical properties and dielectric properties of (CBT). The x-ray diffraction revealed the formation of single orthorhombic phase. As for the dielectric properties (dielectric constant and dielectric loss) were measured at 30 deg C to 450 deg C, through which can be verified the presence of thermally activated processes. This phase has properties very relevant for possible use in capacitive devices, miniaturized filters, dielectric resonators antennas and oscillators. (author)

  3. REFINEMENT OF THE NEPHELINE DISCRIMINATOR: RESULTS OF A PHASE II STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K; Tommy Edwards, T

    2008-11-21

    Twenty five glass compositions were selected for a Phase II study to assess the potential for reducing the conservatism in the nepheline discriminator. The glass compositions were restricted to regions that fell within the validation ranges of the DWPF PCCS models. In addition, the liquidus temperature model was used to restrict the glass compositions so that they could all be melted at the same temperature. The nepheline discriminator was used to force the glass compositions into regions where nepheline formation was predicted to occur. The glasses were fabricated in the laboratory and characterized for crystallization and chemical durability after both quenching and slow cooling. Chemical analysis showed that the fabricated glasses met the target compositions. Nepheline was identified in one of the quenched glasses and several of the CCC glasses. There was no clear relationship between the types of crystallization that occurred in a particular glass and its location on the Al{sub 2}O{sub 3}-Na{sub 2}O-SiO{sub 2} ternary diagram. A partitioning algorithm was used to identify trends in crystallization behavior based on glass composition. Generally, for the CCC glasses MnO influenced the crystallization of spinels and B{sub 2}O{sub 3} and SiO{sub 2} influenced the crystallization of nepheline. Measured durability responses varied from acceptable to unacceptable depending on the glass composition and type and extent of crystallization that occurred. It was not possible to identify any linear effects of composition on chemical durability performance for this set of study glasses. The results were not sufficient to recommend modification of the current nepheline discriminator at this time. It is recommended that the next series of experiments continue to focus not only on compositional regions where the PCCS models are considered applicable (i.e., the model validation ranges), but also be restricted to compositional regions where acceptable glasses are predicted to be

  4. De-chlorination and solidification of radioactive LiCl waste salt by using SiO{sub 2}-Al{sub 2}O{sub 3}-P{sub 2}O{sub 5} (SAP) inorganic composite including B{sub 2}O{sub 3} component

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ki Rak; Park, Hwan-Seo; Cho, In-Hak; Choi, Jung-Hoon; Eun, Hee-Chul; Lee, Tae-Kyo; Han, Seung Youb; Ahn, Do-Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-09-15

    SAP (SiO{sub 2}-Al{sub 2}O{sub 3}-P{sub 2}O{sub 5}) composite has been recently studied in KAERI to deal with the immobilization of radioactive salt waste, one of the most problematic wastes in the pyro-chemical process. Highly unstable salt waste was successfully converted into stable compounds by the dechlorination process with SAPs, and then a durable waste form with a high waste loading was produced when adding glassy materials to dechlorination product. In the present study, U-SAP composite which is SAP bearing glassy component (Boron) was synthesized to remove the adding and mixing steps of glassy materials for a monolithic wasteform. With U-SAPs prepared by a sol-gel process, a series of wasteforms were fabricated to identify a proper reaction condition. Physical and chemical properties of dechlorination products and U-SAP wasteforms were characterized by XRD, DSC, SEM, TGA and PCT-A. A U-SAP wasteform showed suitable properties as a radioactive wasteform such as dense surface morphology, high waste loading, and high durability at the optimized U-SAP/salt ratio 2.

  5. Study

    Directory of Open Access Journals (Sweden)

    Erum Zahir

    2017-05-01

    Full Text Available Physicochemical properties like density, viscosity, boiling point, saponification value (SV, iodine value (IV,and peroxide value (PV of Corn and Mustard oils were studied to evaluate the compositional quality of oils and also to investigate the effect on the use of same oil for repeated frying as it ultimately changes the physicochemical, nutritional and sensory properties of the oil. FT-IR spectroscopy was used to evaluate the degree of oxidation after heating and frying processes. Results revealed that due to the temperature change in the oil there is a notable difference in the spectral band which showed that the proportions of the fatty acids were changed. The spectra of Corn oil at the boiling point and at multiple frying times with a piece of potato showed frequencies in range of 2852.7–2926.0 cm−1 while in Mustard oil an additional peak was observed at 3633.8 cm−1 which exhibits the secondary oxidized product formation.

  6. Controlled and selective placement of boron subphthalocyanines on either chain end of polymers synthesized by nitroxide mediated polymerization

    Directory of Open Access Journals (Sweden)

    Benoît H. Lessard

    2015-10-01

    Full Text Available In previous studies, we synthesized the first organic light emitting diode (OLED using boron subphthalocyanines (BsubPcs based polymers. When designing new polymer materials for organic electronic applications such as OLEDs or organic photovoltaic (OPV devices it is important to consider not only the contribution of each monomer but also the polymer chain ends. In this paper we establish a post-polymerization strategy to couple BsubPcs onto either the α- or the ω-chain end using chemically selective BsubPc derivatives. We outline how the chain ends of two representative polymers, poly(styrene (PS and poly(n-butylacrylate (BA, synthesized by nitroxide mediated polymerization (NMP, using BlocBuilder-MA as the initiating species, can be chemically modified by the incorporation of BsubPc chromophores. The addition of the BsubPc chromophore was confirmed through the use of a photodiode array detector (PDA connected in-line with a gel permeation chromatography (GPC setup. These findings represent the first reported method for the controlled and selective placement of a BsubPc chromophores on either end of a polymer produced by NMP. This strategy will therefore be utilized to make next generation BsubPc polymers for OLEDs and OPV devices. The extremely high molar extinction coefficient of BsubPc also make these polymers ideally suited for dye-labelling of polymers.

  7. Decays of J/psi (3100) to baryon final states

    Energy Technology Data Exchange (ETDEWEB)

    Eaton, M.W.

    1982-05-01

    We present results for the decays of psi(3100) into baryon and hyperon final states. The sample studied here consists of 1.3 million produced psi decays. The decays into nonstrange baryons agree well with currently established results, but with better statistics. In addition, significant resonance formation in multibody final states is observed. The decay psi ..-->.. anti pp..gamma.., the first direct photon decay of the psi involving baryons in the final state, is presented and the theoretical implications of the decays are briefly explored. Several new decays of the psi involving strange baryons are explored, including the first observations of three body final states involving hyperons. The I-spin symmetry of the strong decay psi ..-->.. baryons has clearly been observed. The reduced matrix elements for psi ..-->.. B anti B are presented for final states of different SU(3) content. The B/sub 8/ anti B/sub 8/ results are in excellent agreement with the psi being an SU(3) singlet as are the results for psi ..-->.. B/sub 10/ anti B/sub 10/. We present the first evidence for the SU(3) violating decays of the type psi ..-->.. B/sub 8/ anti B/sub 10/ + c.c.. Angular distributions for psi ..-->.. B/sub 8/ anti B/sub 8/ are presented and compared with theoretical predictions. Statistics are limited, but the data tends to prefer other than a 1 + Cos/sup 2/theta distribution.

  8. Studies of thermal energy confinement scaling in PDX plasmas: D/sup 0/. -->. H/sup +/ limiter discharges

    Energy Technology Data Exchange (ETDEWEB)

    Kaye, S.M.; Goldston, R.J.; Bell, M.; Bol, K.; Bitter, M.; Fonck, R.; Grek, B.; Hawryluk, R.J.; Johnson, D.; Kaita, R.

    1984-06-01

    Experiments were performed on the PDX tokamak to study plasma heating and ..beta.. scaling with higher power, near-perpendicular neutral beam injection. The data taken during these experiments were analyzed using a time-dependent data interpretation code (TRANSP) to study the transport and thermal confinement scaling over a wide range of plasma parameters. This study focuses on results from experiments with D/sup 0/ injection into H/sup +/ plasmas using graphite rail limiters, a = 40 to 44 cm, R = 143 cm, I/sub p/ = 200 to 480 kA, B/sub T/ = 0.7 to 2.2 T, and typically anti n/sub e/ = 2.5 to 4.2 x 10/sup 13/ cm/sup -3/. The results of this study indicate that for both ohmic and neutral beam heated discharges the energy flow out of the plasma is dominated by anomalous electron losses, attributed to electron thermal conduction. The ion conduction losses are well described to electron thermal conduction. The ion conduction losses are well described by neoclassical theory; however, the total ion loss influences the power balance significantly only at high toroidal fields and high plasma currents.

  9. Studies of transition states and radicals by negative ion photodetachment

    Energy Technology Data Exchange (ETDEWEB)

    Metz, R.B.

    1991-12-01

    Negative ion photodetachment is a versatile tool for the production and study of transient neutral species such as reaction intermediates and free radicals. Photodetachment of the stable XHY{sup {minus}} anion provides a direct spectroscopic probe of the transition state region of the potential energy surface for the neutral hydrogen transfer reaction X + HY {yields} XH + Y, where X and Y are halogen atoms. The technique is especially sensitive to resonances, which occur at a specific energy, but the spectra also show features due to direct scattering. We have used collinear adiabatic simulations of the photoelectron spectra to evaluate trail potential energy surfaces for the biomolecular reactions and have extended the adiabatic approach to three dimensions and used it to evaluate empirical potential energy surfaces for the I + Hl and Br + HI reactions. In addition, we have derived an empirical, collinear potential energy surface for the Br + HBr reaction that reproduces our experimental results and have extended this surface to three dimensions. Photodetachment of a negative ion can be also used to study neutral free radicals. We have studied the vibrational and electronic spectroscopy of CH{sub 2}NO{sub 2} by photoelectron spectroscopy of CH{sub 2}NO{sub 2}{sup {minus}}, determining the electron affinity of CH{sub 2}NO{sub 2}, gaining insight on the bonding of the {sup 2}B{sub 1} ground state and observing the {sup 2}A{sub 2} excited state for the first time. Negative ion photodetachment also provides a novel and versatile source of mass-selected, jet-cooled free radicals. We have studied the photodissociation of CH{sub 2}NO{sub 2} at 270, 235, and 208 nm, obtaining information on the dissociation products by measuring the kinetic energy release in the photodissociation.

  10. Molecular dynamics study of structural changes versus deposited energy dose in a sodium borosilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Bureau, G.; Delaye, J.M.; Peuget, S. [DEN/DTCD/SECM, CEA Marcoule, BP 17171, Bagnols-sur-Ceze cedex, 30207 (France); Calas, G. [IMPMC, 140 rue de Lourmel, Paris, 75015 (France)

    2008-07-01

    Assessing the long-term behavior of nuclear glass implies evaluating the impact of cumulative alpha decay induced by the minor actinides it contains. When subjected to alpha decay ({sup 244}Cm-doped glass specimens) or to external ion irradiation, some macroscopic properties vary appreciably with the dose. Above a given dose level, the properties do not evolve any more. To improve our understanding of these modifications, studies are carried out on simplified glass compositions (three oxides SiO{sub 2}, B{sub 2}O{sub 3}, Na{sub 2}O), modeled by molecular dynamics in which irradiation effects are simulated by accelerating uranium projectiles. Accumulation of displacements cascades have been performed up to 4.5*10{sup 20} keV/cm{sup 3} nuclear energy deposited in the glass. The density variations observed in actinide-doped materials is qualitatively reproduced. At high doses, the swelling tends to stabilize. Marples model is used to fit the glass swelling versus the deposited energy dose, giving the volume damaged per projectile. This volume approximates the cascade core volume, suggesting that the underlying mechanisms of volume expansion are contained in the cascade core and are thus related to the highest energy events: atom ejection and thermal quenching. On the contrary, the volumetric parameter of the Marples model applied to the other structural properties is related to a volume corresponding to the core + periphery of the cascades. (authors)

  11. Development of in vitro models for cellular and molecular studies in toxicology and chemoprevention

    Energy Technology Data Exchange (ETDEWEB)

    Mace, K.; Offord, E.A.; Harris, C.C.; Pfeifer, A.M.A. [Nestle Research Center, Lausanne (Switzerland)

    1998-12-31

    Many natural dietary phytochemicals found compounds found in fruits, vegetables, spices and tea have been shown in recent years to be protective against cancer in various animal models. In the light of the potential impact of these compounds on human health it is important to elucidate the mechanisms involved. We therefore developed and characterized relevant in vitro models using immortalized human epithelial cell lines derived from target tissues in carcinogenesis, such as lung, liver and colon. Assays were established, allowing the evaluation of the cytotoxic and genotoxic effects of various procarcinogens, including nitrosamines, mycotoxins and heterocyclic amines on these metabolically-competent human epithelial cell lines. These cellular models appeared to be a useful tool to study the capacity of certain food components to block the initiation stage of carcinogenesis. The ability of carnosol and carnosic acid from rosemary as well as the synthetic dithiolethione, oltipraz, to block the formation of DNA adducts, and their effects on the expression of phase I and phase II enzymes was investigated. We have observed that both rosemary extracts and oltiprax inhibited benzo(a)pyrene- or aflatoxin B{sub 1}-induced DNA adduct formation by strongly inhibiting CYP{sub 450} activities and inducing the expression of glutathione S-transferase. These results in human cell models give some insight into the different mechanisms involved in the chemopreventive action of both natural and synthetic compounds in relation to phase I and phase II enzymes. (orig.)

  12. Study on nuclear physics of high burnup full MOX PWR core

    Energy Technology Data Exchange (ETDEWEB)

    Kugo, Teruhiko; Shimada, Syoichiro; Okubo, Tsutomu; Ochiai, Masaaki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-10-01

    As one of options for future light water reactors, we have been studying a new concept of a high burnup full MOX PWR core. We have proposed a core of 600 MWe to ensure discharged burnup of 100 GWd/t by increasing a moderator to fuel volume ratio to 2.6 with enlarged fuel pin pitch of 13.8 mm, and have investigated its feasibility in neutronics. A plutonium fissile content of 12% is needed for this core. A soluble boric acid with B-10 enrichment of 40% is able to control burnup reactivity without increasing a capacity of boron tanks. A control rod cluster with use of natural boron carbide (B{sub 4}C) per three fuel assemblies ensures a shutdown margin of more than 2%dk/kk`. A moderator temperature and void coefficients are negative through an operating cycle. Although the use of burnable poisons like Gd{sub 2}O{sub 3} and Er{sub 2}O{sub 3} is not necessary to reduce an excess reactivity, it can lower a radial power peaking factor by about 0.1. (author)

  13. Doping chloro boron subnaphthalocyanines and chloro boron subphthalocyanine in simple OLED architectures yields warm white incandescent-like emissions

    Science.gov (United States)

    Plint, Trevor G.; Lessard, Benoît H.; Bender, Timothy P.

    2018-01-01

    We have incorporated chloro boron subphthalocyanine (Cl-BsubPc) and chloro boron subnapthalocyanines (Cl-ClnBsubNcs) into organic light emitting diodes (OLEDs) that enabled an overall warm white emission with CIE coordinates close to that of a 60 W incandescent lightbulb. More specifically, we have shown that Cl-BsubPc and Cl-ClnBsubNcs can be used as dopant emitters in a simple host-dopant architecture, and we have compared the use of NPB and Alq3 as potential hosts for these materials. When doped into Alq3, Cl-BsubPc shows a strong orange emission, and Cl-ClnBsubNcs shows a moderately strong red emission. We have further demonstrated that Cl-BsubPc and Cl-ClnBsubNcs can be co-doped into the same layer giving combined orange and red emission peaks. A "cascade" energy transfer mechanism of sequential absorption and re-emission is proposed. Device performance characteristics such as luminance, current efficiency, photoluminescence efficiency, and external quantum efficiency are tabulated. Additionally, in view of ongoing research into white emitting OLEDs for indoor lighting purposes, the Colour Rendering Index (CRI), R9 values, and CIE co-ordinates for these devices are also discussed. We conclude from this study that the BsubNc chromophore has potential application as a red dopant in OLEDs including for indoor lighting. Additionally, given the scope for axial and peripheral derivatization of the BsubNc motif, we believe that this chromophore has many unexplored molecular design handles that will affect its ultimate performance and application in OLEDs and other opto-electronic devices.

  14. Studies on the oxygen precipitation in highly boron doped silicon; Untersuchungen zur Sauerstoffausscheidung in hoch bordotiertem Silicium

    Energy Technology Data Exchange (ETDEWEB)

    Zschorsch, Markus

    2007-12-14

    The aim of this thesis was the getting of new knowledge on the elucidation of the oxygen precipitation in highly doped silicon. In the study of the early phases of the oxygen precipitation boron-oxygen complexes and their kinetics could be indirectly detected. These arise already during the cooling of the crystal and can be destroyed by subsequent temperature processes. The formation of the here as BO assumed species during the cooling after the silicon crystal fabrication could be numerically reproduced. Furthermore the study of early precipitation phases by means of neutron small angle scattering a maximum of the oxygen precipitation at {rho}=9 m{omega}cm. It could be shown that the decreasing of this at increasing boron concentration can be most probably reduced to boron precipitations. Furthermore it could be shown that after a tempering time of 24 hours at 700 C in silicon with {rho}=9 m{omega}cm platelet-shaped precipitates form. By the study of the precipitate growth could be shown that also in this phase the oxygen precipitation in silicon is strongest with a specific resistance of {rho}=9 m{omega}cm. By means of FTIR spectroscopy a new absorption band at a wave number of 1038 cm{sup -1} was found, which could be assigned to a boron species. By different experiments it is considered as probable that at this species it deals with BI respectively B{sub 2}I complexes.

  15. New ternary tantalum borides containing boron dumbbells: Experimental and theoretical studies of Ta{sub 2}OsB{sub 2} and TaRuB

    Energy Technology Data Exchange (ETDEWEB)

    Mbarki, Mohammed; Touzani, Rachid St.; Rehorn, Christian W.G.; Gladisch, Fabian C. [Institute of Inorganic Chemistry, RWTH Aachen University, D-52056 Aachen (Germany); Fokwa, Boniface P.T., E-mail: bfokwa@ucr.edu [Institute of Inorganic Chemistry, RWTH Aachen University, D-52056 Aachen (Germany); Department of Chemistry, University of California Riverside (UCR), Riverside, CA 92521 (United States)

    2016-10-15

    The new ternary transition metal-rich borides Ta{sub 2}OsB{sub 2} and TaRuB have been successfully synthesized by arc-melting the elements in a water-cooled crucible under an argon atmosphere. The crystal structures of both compounds were solved by single-crystal X-ray diffraction and their metal compositions were confirmed by EDX analysis. It was found that Ta{sub 2}OsB{sub 2} and TaRuB crystallize in the tetragonal Nb{sub 2}OsB{sub 2} (space group P4/mnc, no. 128) and the orthorhombic NbRuB (space group Pmma, no. 51) structure types with lattice parameters a=5.878(2) Å, c=6.857(2) Å and a=10.806(2) Å, b=3.196(1) Å, c=6.312(2) Å, respectively. Furthermore, crystallographic, electronic and bonding characteristics have been studied by density functional theory (DFT). Electronic structure relaxation has confirmed the crystallographic parameters while COHP bonding analysis indicates that B{sub 2}-dummbells are the strongest bonds in both compounds. Moreover, the formation of osmium dumbbells in Ta{sub 2}OsB{sub 2} through a Peierls distortion along the c-axis, is found to be the origin of superstructure formation. Magnetic susceptibility measurements reveal that the two phases are Pauli paramagnets, thus confirming the theoretical DOS prediction of metallic character. Also hints of superconductivity are found in the two phases, however lack of single phase samples has prevented confirmation. Furthermore, the thermodynamic stability of the two modifications of AMB (A=Nb, Ta; M =Ru, Os) are studied using DFT, as new possible phases containing either B{sub 4}- or B{sub 2}-units are predicted, the former being the most thermodynamically stable modification. - Graphical abstract: The two new ternary tantalum borides, Ta{sub 2}OsB{sub 2} and TaRuB, have been discovered. Their crystal structures contain boron dumbbells, which are the strongest bonds. Peirls distortion is found responsible for Os{sub 2}-dumbbells formation in Ta{sub 2}OsB{sub 2}. Ta{sub 2}OsB{sub 2} and

  16. Essential and toxic element concentrations in blood and urine and their associations with diet: Results from a Norwegian population study including high-consumers of seafood and game

    Energy Technology Data Exchange (ETDEWEB)

    Birgisdottir, B.E.; Knutsen, H.K.; Haugen, M.; Gjelstad, I.M. [Division of Environmental Medicine, Norwegian Institute of Public Health, Oslo (Norway); Jenssen, M.T.S. [Norwegian Institute for Water Research, Oslo (Norway); Ellingsen, D.G.; Thomassen, Y. [National Institute of Occupational Health, Oslo (Norway); Alexander, J. [Office of the Director-General, Norwegian Institute of Public Health, Oslo (Norway); Meltzer, H.M. [Division of Environmental Medicine, Norwegian Institute of Public Health, Oslo (Norway); Brantsæter, A.L., E-mail: Anne.Lise.Brantsaeter@fhi.no [Division of Environmental Medicine, Norwegian Institute of Public Health, Oslo (Norway)

    2013-10-01

    The first aim of the study was to evaluate calculated dietary intake and concentrations measured in blood or urine of essential and toxic elements in relation to nutritional and toxicological reference values. The second aim was to identify patterns of the element concentrations in blood and urine and to identify possible dietary determinants of the concentrations of these elements. Adults with a known high consumption of environmental contaminants (n = 111), and a random sample of controls (n = 76) answered a validated food frequency questionnaire (FFQ). Complete data on biological measures were available for 179 individuals. Blood and urine samples were analyzed for selenium, iodine, arsenic, mercury, cadmium and lead. Principal component analysis was used to identify underlying patterns of correlated blood and urine concentrations. The calculated intakes of selenium, iodine, inorganic arsenic and mercury were within guideline levels. For cadmium 24% of the high consumer group and 8% of the control group had intakes above the tolerable weekly intake. Concentrations of lead in blood exceeded the bench-mark dose lower confidence limits for some participants. However, overall, the examined exposures did not give rise to nutritional or toxicological concerns. Game consumption was associated with lead in blood (B{sub ln} 0.021; 95%CI:0.010, 0.031) and wine consumption. Seafood consumption was associated with urinary cadmium in non-smokers (B{sub ln} 0.009; 95%CI:0.003, 0.015). A novel finding was a distinct pattern of positively associated biological markers, comprising iodine, selenium, arsenic and mercury (eigenvalue 3.8), reflecting seafood intake (B 0.007; 95%CI:0.004, 0.010). The study clearly demonstrates the significance of seafood as a source of both essential nutrients and toxic elements simultaneously and shows that exposure to various essential and toxic elements can be intertwined. - Highlights: • A study on interplay and sources of six different

  17. Nuclear magnetic resonance study of the RE(Co,B)[sub 5]-type compounds (RE[identical to]Y, Gd). [YCoB; GdCoB

    Energy Technology Data Exchange (ETDEWEB)

    Kapusta, C. (Dept. of Solid State Physcis, Univ. of Mining and Metallurgy, Cracow (Poland)); Rosenberg, M. (Inst. of Experimental Physics 6, Ruhr Univ., Bochum (Germany)); Buschow, K.H.J. (Philips Research Labs., Eindhoven (Netherlands) Kamerlingh Onnes Lab., Univ. of Leiden (Netherlands))

    1992-09-25

    The nuclear magnetic resonance spin echo spectra of RECo[sub 5], RECo[sub 4]B, RE[sub 3]Co[sub 11]B[sub 4], RE[sub 2]Co[sub 7]B[sub 3] and RECo[sub 3]B[sub 2] (RE = Y, Gd) at 4.2 K are presented. An assignment of the resonance lines to the various cobalt sites in these compounds is proposed. The variations in the cobalt hyperfine field observed between different cobalt sites and different compounds are analysed in terms of spin and orbital contributions to the cobalt moments. The cobalt hyperfine fields at sites of the same symmetry and nearest-neighbour configuration are similar in the different compounds. The gadolinium hpyerfine field in GdCo[sub 3]B[sub 2] is close to the free ion value. The temperature-independent Knight shift of cobalt and boron observed in YCo[sub 3]B[sub 2] indicates that this compound is a Pauli paramagnet. (orig.).

  18. Excited state non-adiabatic dynamics of N-methylpyrrole: A time-resolved photoelectron spectroscopy and quantum dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Guorong [National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada); State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023 (China); Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Neville, Simon P. [Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, Ontario K1N 6N5 (Canada); Schalk, Oliver [National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada); Department of Physics, AlbaNova University Center, Stockholm University, Roslagstullsbacken 21, 106 91 Stockholm (Sweden); Sekikawa, Taro [Department of Applied Physics, Hokkaido University, Kita-13 Nishi-8, Kita-ku, Sapporo 060-8628 (Japan); Ashfold, Michael N. R. [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Worth, Graham A. [School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Stolow, Albert, E-mail: astolow@uottawa.ca [National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada); Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, Ontario K1N 6N5 (Canada); Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5 (Canada)

    2016-01-07

    The dynamics of N-methylpyrrole following excitation at wavelengths in the range 241.5-217.0 nm were studied using a combination of time-resolved photoelectron spectroscopy (TRPES), ab initio quantum dynamics calculations using the multi-layer multi-configurational time-dependent Hartree method, as well as high-level photoionization cross section calculations. Excitation at 241.5 and 236.2 nm results in population of the A{sub 2}(πσ{sup ∗}) state, in agreement with previous studies. Excitation at 217.0 nm prepares the previously neglected B{sub 1}(π3p{sub y}) Rydberg state, followed by prompt internal conversion to the A{sub 2}(πσ{sup ∗}) state. In contrast with the photoinduced dynamics of pyrrole, the lifetime of the wavepacket in the A{sub 2}(πσ{sup ∗}) state was found to vary with excitation wavelength, decreasing by one order of magnitude upon tuning from 241.5 nm to 236.2 nm and by more than three orders of magnitude when excited at 217.0 nm. The order of magnitude difference in lifetimes measured at the longer excitation wavelengths is attributed to vibrational excitation in the A{sub 2}(πσ{sup ∗}) state, facilitating wavepacket motion around the potential barrier in the N–CH{sub 3} dissociation coordinate.

  19. Study of charmonium production in b-hadron decays and first evidence for the decay B{sup 0}{sub s} → φφφ

    Energy Technology Data Exchange (ETDEWEB)

    Aaij, R. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Adeva, B. [Santiago de Compostela Univ. (Spain); Adinolfi, M. [Bristol Univ. (United Kingdom). H.H. Wills Physics Lab.; Collaboration: LHCb Collaboration; and others

    2017-09-15

    Using decays to φ-meson pairs, the inclusive production of charmonium states in b-hadron decays is studied with pp collision data corresponding to an integrated luminosity of 3.0 fb{sup -1}, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. Denoting by B{sub C} ≡ B(b → CX) x B(C → φφ) the inclusive branching fraction of a b hadron to a charmonium state C that decays into a pair of φ mesons, ratios R{sub C{sub 2}{sup C{sub 1}}} ≡ B{sub C{sub 1}}/B{sub C{sub 2}} are determined as R{sup χ{sub c}{sub 0η{sub c(1S)}}} = 0.147 ± 0.023 ± 0.011, R{sup χ{sub c}{sub 1η{sub c(1S)}}} = 0.073 ± 0.016 ± 0.006, R{sup χ{sub c}{sub 2η{sub c(1S)}}} = 0.081 ± 0.013 ± 0.005, R{sup χ{sub c}{sub 1χ{sub c{sub 0}}}} = 0.50 ± 0.11 ± 0.01, R{sup χ{sub c}{sub 2χ{sub c{sub 0}}}} = 0.56 ± 0.10 ± 0.01 and R{sup η{sub c}(2S)}{sub η{sub c(1S)}} = 0.040 ± 0.011 ± 0.004. Here and below the first uncertainties are statistical and the second systematic. Upper limits at 90% confidence level for the inclusive production of X(3872), X(3915) and χ{sub c2}(2P) states are obtained as R{sup X(3872)}{sub χ{sub c{sub 1}}} < 0.34, R{sup X(3915)}{sub χ{sub c{sub 0}}} < 0.12 and R{sup χ{sub c}{sub 2}(2P)}{sub χ{sub c{sub 2}}} < 0.16. Differential cross-sections as a function of transverse momentum are measured for the η{sub c}(1S) and χ{sub c} states. The branching fraction of the decay B{sup 0}{sub s} → φφφ is measured for the first time, B(B{sup 0}{sub s} → φφφ) = (2.15 ± 0.54 ± 0.28 ± 0.21{sub B}) x 10{sup -6}. Here the third uncertainty is due to the branching fraction of the decay B{sup 0}{sub s} → φφ, which is used for normalization. No evidence for intermediate resonances is seen. A preferentially transverse φ polarization is observed. The measurements allow the determination of the ratio of the branching fractions for the η{sub c}(1S) decays to φφ and p anti p as B(η{sub c}(1S) → φφ)/B(η{sub c}(1S) → p anti p

  20. 1987 Neutron and gamma personnel dosimeter intercomparison study using a D/sub 2/O-moderated /sup 252/Cf source

    Energy Technology Data Exchange (ETDEWEB)

    Swaja, R.E.; West, L.E.; Sims, C.S.; Welty, T.J.

    1989-05-01

    The thirteenth Personnel Dosimetry Intercomparison Study (i.e., PDIS 13) was conducted during April 1987 as a joint effort by Oak Ridge National Laboratory's (ORNL) Dosimetry Applications Research Group and the Southwest Radiation Calibration Center at the University of Arkansas. A total of 48 organizations (34 from the US and 14 from abroad) participated in PDIS 13. Participants submitted a total of 1,113 neutron and gamma dosimeters for this mixed field study. The dosimeters were transferred by mail and were handled by experimental personnel at ORNL and the University of Arkansas. The type of neutron dosimeter and the percentage of participants submitting that type are as follows: TLD-albedo (49%), direct interaction TLD (31%), CR-39 (17%), film (3%). The type of gamma dosimeter and the percentage of participants submitting that type are as follows: Li/sub 2/B/sub 4/O/sub 7/, alone or in combination with CaSO/sub 4/, (69%), /sup 7/LiF (28%), natural LiF (3%). Radiation exposures in PDIS 13 were limited to 0.5 and 1.5 mSv from /sup 252/Cf moderated by 15-cm of D/sub 2/O. Traditional exposures using the Health Physics Research Reactor (HPRR) were not possible due to the fact that all reactors at ORNL, including the HPRR, were shutdown by order of the Department of Energy at the time the intercomparison was performed. Planned exposures using a /sup 238/PuBe source were negated by a faulty timing mechanism. Based on accuracy and precision, direct interaction TLD dosimeters exhibited the best performance in PDIS 13 neutron measurements. They were followed, in order of best performance, by CR-39, TLD albedo, and film. The Li/sub 2/B/sub 4/O/sub 7/ type TLD dosimeters exhibited the best performance in PDIS 13 gamma measurements. They were followed by natural LiF, /sup 7/LiF, and film. 12 refs., 1 fig., 5 tabs.

  1. Improved Method for CKM Constraints in Charmless Three-body B and Bs Decays

    Energy Technology Data Exchange (ETDEWEB)

    Gronau, Michael; /Technion /SLAC; Pirjol, Dan; /MIT, LNS; Soni, Amarjit; /Brookhaven; Zupan, Jure; /Carnegie Mellon U. /Stefan Inst., Ljubljana

    2006-09-22

    Recently Ciuchini, Pierini and Silvestrini proposed a method for constraining CKM parameters in B {yields} K{pi}{pi} and B{sub s} {yields} K{pi}{pi} through phase measurements of amplitudes involving I = 3/2 K*{pi} final states. We show that complementary information on CKM parameters may be obtained by studying the phases of {Delta}I = 1 B {yields} (K*{pi}){sub I = 1/2}, B{sub s} {yields} (K* {bar K}){sub l=1} and B{sub s} {yields} ({bar K}* K){sub I=1} amplitudes. Hadronic uncertainties in these constraints from electroweak penguin operators O{sub 9} and O{sub 10}, studied using flavor SU(3), are shown to be very small in B {yields} K{pi}{pi} and B{sub s} {yields} K{pi}{pi} and somewhat larger in B{sub s} {yields} K{bar K}{pi}. The first processes imply a precise linear relation between {bar {rho}} and {bar {eta}}, with a measurable slope and an intercept at {bar {eta}} = 0 involving a theoretical error of 0.03. The decays B{sub s} {yields} K{pi}{pi} permit a measurement of involving a theoretical error below a degree. We note that while time-dependence is required when studying B{sup 0} decays at the {Upsilon}(4S), it is not needed when studying B{sub s} decays at hadronic colliders.

  2. High current and low q{sub 95} scenario studies for FAST in the view of ITER and DEMO

    Energy Technology Data Exchange (ETDEWEB)

    Calabrò, G., E-mail: giuseppe.calabro@enea.it [Associazione Euratom-ENEA sulla Fusione, C.P. 65-I-00044 Frascati, Rome (Italy); Crisanti, F.; Ramogida, G. [Associazione Euratom-ENEA sulla Fusione, C.P. 65-I-00044 Frascati, Rome (Italy); Mantica, P.; Baiocchi, B. [Istituto di Fisica del Plasma ‘P.Caldirola’, Associazione Euratom-ENEA-CNR, Milano (Italy); Cucchiaro, A.; Frosi, P.; Fusco, V. [Associazione Euratom-ENEA sulla Fusione, C.P. 65-I-00044 Frascati, Rome (Italy); Liu, Y. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Mastrostefano, S.; Villone, F. [Associazione EURATOM/ENEA/CREATE, DIEI, Università di Cassino e del Lazio Meridionale (Italy); Vlad, G. [Associazione Euratom-ENEA sulla Fusione, C.P. 65-I-00044 Frascati, Rome (Italy); Fresa, R. [Associazione Euratom-ENEA-CREATE, DIFA-Univ. della Basilicata, Via dell’Ateneo Lucano, 10 I-85100 Potenza (Italy)

    2013-10-15

    The Fusion Advanced Study Torus (FAST) has been proposed as a possible European satellite, in view of ITER and DEMO, in order to: (a) explore plasma wall interaction in reactor relevant conditions, (b) test tools and scenarios for safe and reliable tokamak operation up to the border of stability, and (c) address fusion plasmas with a significant population of fast particles. A new FAST scenario has been designed focusing on low-q operation, at plasma current I{sub P} = 10 MA, toroidal field B{sub T} = 8.5 T, with a q{sub 95} ≈ 2.3 that would correspond to I{sub P} ≈ 20 MA in ITER. The flat-top of the discharge can last a couple of seconds (i.e. half the diffusive resistive time and twice the energy confinement time), and is limited by the heating of the toroidal field coils. A preliminary evaluation of the end-of-pulse temperatures and of the electromagnetic forces acting on the central solenoid pack and poloidal field coils has been performed. Moreover, a VDE plasma disruption has been simulated and the maximum total vertical force applied on the vacuum vessel has been estimated.

  3. FTIR and Mössbauer spectroscopic study of sodium–aluminum–iron phosphate glassy materials for high level waste immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Stefanovsky, S.V., E-mail: serge.stefanovsky@yandex.ru [Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, Laboratory of Radioecology and Radiation Problems, Moscow (Russian Federation); Stefanovsky, O.I. [Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, Laboratory of Radioecology and Radiation Problems, Moscow (Russian Federation); Remizov, M.B.; Belanova, E.A.; Kozlov, P.V. [FSUE PA Mayak, Central Plant Laboratory, Ozersk, Chelyabinsk Reg. (Russian Federation); Glazkova, Ya.S.; Sobolev, A.V.; Presniakov, I.A. [Lomonosov Moscow State University, Department of Radiochemistry (Russian Federation); Kalmykov, S.N. [Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, Laboratory of Radioecology and Radiation Problems, Moscow (Russian Federation); Lomonosov Moscow State University, Department of Radiochemistry (Russian Federation); Vernadsky Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences, Laboratory of Radiochemistry, Moscow (Russian Federation); Myasoedov, B.F. [Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, Laboratory of Radioecology and Radiation Problems, Moscow (Russian Federation); Vernadsky Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences, Laboratory of Radiochemistry, Moscow (Russian Federation)

    2015-11-15

    Complex sodium-aluminum-iron phosphate glassy materials with various Al{sub 2}O{sub 3} to Fe{sub 2}O{sub 3} ratio containing high level waste (HLW) surrogate were characterized by X-ray diffraction and scanning electron microscopy and studied in details by Fourier transform infrared (FTIR) spectroscopy. The samples with high Al{sub 2}O{sub 3} content and not containing Fe{sub 2}O{sub 3} were predominantly amorphous but subjected to devitrification under annealing. Addition of B{sub 2}O{sub 3} and partial Fe{sub 2}O{sub 3} substitution for Al{sub 2}O{sub 3} in the materials increases their resistance to devitrification whereas further substitution and NiO incorporation significantly increase the tendency to devitrification. FTIR spectra demonstrate changes in the structure of glassy materials caused by both structural variations in the anionic motif and occurrence of crystalline phases in the materials. According to Mössbauer spectroscopy data, iron in the glassy samples is present as octahedrally coordinated Fe{sup 3+} ions while in the partly devitrified samples iron is partitioned among vitreous and crystalline phases entering the vitreous phase mainly as Fe{sup 3+}O{sub 6} units and crystalline phases as major Fe{sup 3+} and minor Fe{sup 2+} ions in a magnetically ordered state and participating in a “fast” electronic exchange.

  4. Effects of differential rotation on the eigenfrequencies of small adiabatic barotropic modes of oscillations of polytropic models of stars

    Energy Technology Data Exchange (ETDEWEB)

    Lal, A K; Pathania, Ankush [School of Mathematics and Computer Applications, Thapar University, Patiala, Punjab (India); Bhalla, Alka [Department of Mathematics, N.I.T., Jalandhar, Punjab (India); Mohan, C [Professor of Mathematics (Retd.), IIT Roorkee, Uttarakhand (India)], E-mail: aklal@thapar.edu

    2009-12-04

    Mohan et al (1992 Astrophys. Space. Sci. 193 69) (1998 Indian J. Pure Appl. Math. 29 199) investigated the problem of equilibrium structures and periods of small adiabatic oscillations of differentially rotating stellar models using a law of differential rotation of the type {omega}{sup 2} = b{sub 0} + b{sub 1}s{sup 2} + b{sub 2}s{sup 4} (here {omega} is a nondimensional measure of the angular velocity of rotation of a fluid element at a distance s from the axis of rotation and b's are suitably chosen constant parameters). This law of differential rotation assumes cylindrical symmetry for the rotating fluid elements. In the present paper, we have extended their study and used a more general law of differential rotation of the type {omega}{sup 2} = b{sub 0} + b{sub 1}s{sup 2} + b{sub 2}s{sup 4} + b{sub 3}z{sup 2} + b{sub 4}z{sup 4} + b{sub 5}z{sup 2}s{sup 2} in which the angular velocity of rotation of a fluid element is assumed to depend both on its distance s from the axis of rotation and on its distance z from the plane through the center of the star perpendicular to the axis of rotation. The main objective of this study has been to investigate whether the dependence of angular velocity of rotation on the parameter z in addition to the parameter s substantially alters the behavior of the eigenfrequencies of small adiabatic barotropic modes of oscillations of differentially rotating stars or not.

  5. Spectral hole burning studies of photosystem II

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hai -Chou [Iowa State Univ., Ames, IA (United States)

    1995-09-26

    Low temperature absorption and hole burning spectroscopies were applied to the D1-D2-cyt b>559 and the CP47 and CP43 antenna protein complexes of Photosystem H from higher plants. Low temperature transient and persistent hole-burning data and theoretical calculations on the kinetics and temperature dependence of the P680 hole profile are presented and provide convincing support for the linker model. Implicit in the linker model is that the 684-nm-absorbing Chl a serve to shuttle energy from the proximal antenna complex to reaction center. The stoichiometry of isolated Photosystem H Reaction Center (PSII RC) in several different preparations is also discussed. The additional Chl a are due to 684-nm-absorbing Chl a, some contamination by the CP47 complex, and non-native Chl a absorbing near 670 nm. In the CP47 protein complex, attention is focused on the lower energy chlorophyll a Qy-states. High pressure hole-burning studies of PSII RC revealed for the first time a strong pressure effect on the primary electron transfer dynamics. The 4.2 K lifetime of P680*, the primary donor state, increases from 2.0 ps to 7.0 ps as pressure increases from 0.1 to 267 MPa. Importantly, this effect is irreversible (plastic) while the pressure induced effect on the low temperature absorption and non-line narrowed P680 hole spectra are reversible (elastic). Nonadiabatic rate expressions, which take into account the distribution of energy gap values, are used to estimate the linear pressure shift of the acceptor state energy for both the superexchange and two-step mechanisms for primary charge separation. It was found that the pressure dependence could be explained with a linear pressure shift of ~1 cm-1/MPa in magnitude for the acceptor state. The results point to the marriage of hole burning and high pressures as having considerable potential for the study of primary transport dynamics in reaction centers and antenna complexes.

  6. Spectroscopic studies of neutral and chemically oxidized species of β-carotene, lycopene and norbixin in CH{sub 2}Cl{sub 2}: Fluorescence from intermediate compounds

    Energy Technology Data Exchange (ETDEWEB)

    Alwis, D.D.D.H [Department of Chemistry, The Open University of Sri Lanka, Nawala (Sri Lanka); Department of Chemistry, University of Sri Jayewardenepura, Nugegoda (Sri Lanka); Chandrika, U.G. [Department of Biochemistry, University of Sri Jayewardenepura, Nugegoda (Sri Lanka); Jayaweera, P.M., E-mail: pradeep@sjp.ac.lk [Department of Chemistry, University of Sri Jayewardenepura, Nugegoda (Sri Lanka)

    2015-02-15

    Radical cations, dications and oxidized intermediate species of three carotenoids, namely, β-carotene, lycopene and norbixin, were generated in CH{sub 2}Cl{sub 2} solutions via chemical oxidation using anhydrous FeCl{sub 3}. UV–vis, fluorescence and fluorescence-excitation spectroscopic studies were performed to understand and compare the nature of intermediate species generated during the chemical oxidation process and subsequent degradation. The intense emission observed at 550 nm can be assigned to the S{sub 2}→S{sub 0} (1{sup 1}B{sub u}→1{sup 1}A{sub g}) transition of the carotenoid molecules. The 350 nm excitation during the oxidation process for β-carotene, lycopene and norbixin exhibit intense fluorescence peaks at 492 nm, 493 nm and 500 nm, respectively. These peaks are assigned to intermediate peroxy/epoxy compounds of the three molecules that are formed with molecular oxygen prior to the formation of oxidized short-chain stable compounds. - Highlights: • Fluorescence and UV–vis studies on β-carotene, lycopene and norbixin. • Oxidation, induced by FeCl{sub 3} in CH{sub 2}Cl{sub 2} shows blue shifted fluorescence peaks. • Fluorescence peaks were assigned to intermediate peroxy/epoxy forms of carotenoids. • The D0→D3 transition of radical cations are observed in the near IR region.

  7. Radiation environment simulations at the Tevatron, studies of the beam profile and measurement of the Bc meson mass

    Energy Technology Data Exchange (ETDEWEB)

    Nicolas, Ludovic Y. [Univ. of Glasgow, Scotland (United Kingdom)

    2005-09-01

    The description of a computer simulation of the CDF detector at Fermilab and the adjacent accelerator parts is detailed, with MARS calculations of the radiation background in various elements of the model due to the collision of beams and machine-related losses. Three components of beam halo formation are simulated for the determination of the principal source of radiation background in CDF due to beam losses. The effect of a collimator as a protection for the detector is studied. The simulation results are compared with data taken by a CDF group. Studies of a 150 GeV Tevatron proton beam are performed to investigate the transverse diffusion growth and distribution. A technique of collimator scan is used to scrape the beam under various experimental conditions, and computer programs are written for the beam reconstruction. An average beam halo growth speed is given and the potential of beam tail reconstruction using the collimator scan is evaluated. A particle physics analysis is conducted in order to detect the Bc → J/Ψπ decay signal with the CDF Run II detector in 360 pb-1 of data. The cut variables and an optimization method to determine their values are presented along with a criterion for the detection threshold of the signal. The mass of the B{sub c} meson is measured with an evaluation of the significance of the signal.

  8. Reflector and Shield Material Properties for Project Prometheus

    Energy Technology Data Exchange (ETDEWEB)

    J. Nash

    2005-11-02

    This letter provides updated reflector and shield preliminary material property information to support reactor design efforts. The information provided herein supersedes the applicable portions of Revision 1 to the Space Power Program Preliminary Reactor Design Basis (Reference (a)). This letter partially answers the request in Reference (b) to provide unirradiated and irradiated material properties for beryllium, beryllium oxide, isotopically enriched boron carbide ({sup 11}B{sub 4}C) and lithium hydride. With the exception of {sup 11}B{sub 4}C, the information is provided in Attachments 1 and 2. At the time of issuance of this document, {sup 11}B{sub 4}C had not been studied.

  9. Compactification of M(atrix) theory on noncommutative toroidal orbifolds

    Energy Technology Data Exchange (ETDEWEB)

    Konechny, Anatoly E-mail: konechny@thsrv.lbl.gov; Schwarz, Albert E-mail: schwarz@math.ucdavis.edu

    2000-12-25

    It was shown by A. Connes, M. Douglas and A. Schwarz that noncommutative tori arise naturally in consideration of toroidal compactifications of M(atrix) theory. A similar analysis of toroidal Z{sub 2} orbifolds leads to the algebra B{sub {theta}} that can be defined as a crossed product of noncommutative torus and the group Z{sub 2}. Our paper is devoted to the study of projective modules over B{sub {theta}} (Z{sub 2}-equivariant projective modules over a noncommutative torus). We analyze the Morita equivalence (duality) for B{sub {theta}} algebras working out the two-dimensional case in detail.

  10. Decay study of {sup 246}Fm at SHIP

    Energy Technology Data Exchange (ETDEWEB)

    Venhart, M. [Comenius University, Department of Nuclear Physics and Biophysics, Bratislava (Slovakia); Slovak Academy of Sciences, Institute of Physics, Bratislava (Slovakia); Hessberger, F.P.; Ackermann, D.; Heinz, S.; Kindler, B.; Kojouharov, I.; Lommel, B.; Mann, R. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Antalic, S.; Saro, S. [Comenius University, Department of Nuclear Physics and Biophysics, Bratislava (Slovakia); Gray-Jones, C.; Herzberg, R.D.; Papadakis, P. [University of Liverpool, Department of Physics, Liverpool (United Kingdom); Greenlees, P.T.; Ketelhut, S.; Leino, M. [University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland); Hofmann, S. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Goethe-Universitaet, Institut fuer Kernphysik, Frankfurt am Main (Germany); Rostron, D. [Goethe-Universitaet, Institut fuer Kernphysik, Frankfurt am Main (Germany); Rudolph, D. [Lund University, Department of Physics, Lund (Sweden); Sulignano, B. [CEA Saclay, DAPNIA/SPhN, Gif/Yvette Cedex (France)

    2011-02-15

    The decay chain of {sup 246}Fm has been investigated employing the SHIP separator at GSI Darmstadt. The {sup 246}Fm nuclei were produced via the {sup 40}Ar({sup 208}Pb, 2n){sup 246}Fm fusion-evaporation reaction. Improved values of the half-life, T{sub 1/2} = 1.54(4) s, and of the spontaneous fission branching ratio, b{sub SF} = 0.068(6), of {sup 246}Fm were obtained. The {beta}{sup +} /electron capture branching ratio, b{sub EC} = 0.39(3), of {sup 242}Cf was deduced. Possible structures of high-K states in {sup 246}Fm are discussed within the framework of a model calculation based on the Woods-Saxon potential. (orig.)

  11. Soft X-ray emission studies of biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Kurmaev, E.Z. E-mail: kurmaev@ifmlrs.uran.ru; Werner, J.P.; Moewes, A.; Chiuzbaian, S.; Bach, M.; Ching, W.-Y.; Motozaki, W.; Otsuka, T.; Matsuya, S.; Endo, K.; Neumann, M

    2004-07-01

    Soft X-ray fluorescence measurements are used to characterize three groups of biomaterials: Vitamin B{sub 12} and derivatives, antioxidants (aspirin and paracetamol), and human teeth. We show that the chemical bonding in Vitamin B{sub 12} is characterized by the strong Co-C bond and the relatively weak Co-N bond. The Co-C bond in cyanocobalamin is found to be stronger than that of methylcobalamin leading to their different biological activity. The chemical bonding of paracetamol and aspirin is characterized by the formation of oxygen lone-pair {pi}-orbitals, which can neutralize free radicals and therefore be related to antioxidant activity of these compounds. Carbon K{alpha} emission spectra of a caries lesion suggest that the CaCO{sub 3} like phase exists in sound enamel and that a selective loss of carbonate occurs during the early stages of a caries attack.

  12. Synthesis and evaluation of [{sup 123}I]labelled analogues of the partial inverse agonist Ro 15-4513 for the study of diazepam-insensitive benzodiazepine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Katsifis, Andrew E-mail: akx@ansto.gov.au; Mardon, Karine; McPhee, Meredith; Mattner, Filomena; Dikic, Branko; Ridley, Damon

    1999-08-01

    The imidazobenzodiazepines ethyl 8-iodo-5,6 dihydro-5-methyl-6-oxo-4H-imidazo[1,5a][1,4] benzodiazepine-3-carboxylate 1 and tert-butyl 8-iodo-5,6 dihydro-5-methyl-6-oxo-4H-imidazo [1,5a][1,4] benzodiazepine-3-carboxylate 2 were prepared to study the diazepam-insensitive (DI) benzodiazepine receptor (BZR) subtype. The [{sup 123}I] analogues were prepared via iododestannylation reactions in radiochemical yields of 70-80% and a specific activity >2,500 Ci/mmol. The tert-butyl analogue [{sup 123}I]-2 exhibited nanomolar affinity for BZRs in homogenate membranes of rat cerebellum with K{sub d} values for the diazepam-sensitive (DS) and DI receptors of 3.18{+-}0.58 and 13.55{+-}2.72 nM, respectively. The B{sub max} for cerebellar DS and DI receptors were 1,276{+-}195 and 518{+-}26 fmol/mg protein, respectively.

  13. Study of the K{sup ±}→π{sup ±}γγ decay by the NA62 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lazzeroni, C.; Romano, A.; Ceccucci, A.; Danielsson, H.; Falaleev, V.; Gatignon, L.; Goy Lopez, S.; Hallgren, B.; Maier, A.; Peters, A.; Piccini, M.; Riedler, P.; Frabetti, P.L.; Gersabeck, E.; Kekelidze, V.; Madigozhin, D.; Misheva, M.; Molokanova, N.; Movchan, S.; Potrebenikov, Yu.; and others

    2014-05-01

    A study of the dynamics of the rare decay K{sup ±}→π{sup ±}γγ has been performed on a sample of 232 decay candidates, with an estimated background of 17.4±1.1 events, collected by the NA62 experiment at CERN in 2007. The results are combined with those from a measurement conducted by the NA48/2 Collaboration at CERN. The combined model-independent branching ratio in the kinematic range z=(m{sub γγ}/m{sub K}){sup 2}>0.2 is B{sub MI}(z>0.2)=(0.965±0.063)×10{sup −6}, and the combined branching ratio in the full kinematic range assuming a Chiral Perturbation Theory description is B(K{sub πγγ})=(1.003±0.056)×10{sup −6}. A detailed comparison of the results with the previous measurements is performed.

  14. Thermoluminescence study of Cu and Ag doped lithium tetraborate samples synthesized by water/solution assisted method

    Energy Technology Data Exchange (ETDEWEB)

    Thiyagarajan, S.; Kumar, S.; Vallejo, M.; Sosa, M. [Universidad de Guanajuato, Departamento de Ingenieria Fisica, 37150 Leon, Guanajuato (Mexico); Velusamy, J., E-mail: thiya93@gmail.com [Centro de Investigaciones en Optica, Apdo. Postal 1-948, Leon, Guanajuato (Mexico)

    2016-10-15

    In this paper lithium tetraborate (Li{sub 2}B{sub 4}O{sub 7}) was produced by water/solution assisted synthesis method. Transition metals, such as Cu and Ag were used to dope Li{sub 2}B{sub 4}O{sub 7} in order to enhance its thermoluminescent properties. The heating temperature parameters for synthesis were 750 degrees Celsius for 2 hours and 150 degrees Celsius for another 2 hours. The samples produced by water assisted method were doped at different doping percentage (0.08, 0.12, 0.5, 0.1 and 1%) of Cu and Ag. Pellets of samples were prepared and there were irradiated with different doses (58, 100, 500 and 945 mGy) by using and X-ray source. The characteristics of undoped and doped Li{sub 2}B-4O{sub 7} were determined by X-ray diffraction (XRD), scanning electron microscopy (Sem), photoluminescence and ultraviolet-visible spectroscopy. The chemical composition and their morphologies of the obtained Li{sub 2}B{sub 4}O{sub 7} and Li{sub 2}B{sub 4}O{sub 7}:Cu, Ag was confirmed by XRD and Sem results. The most intense peak of the XRD pattern of the lithium tetraborate sample was determined by comparing to the reference data and was found to have a tetragonal structure. The thermoluminescent glow curves of the pellets exposed to different doses exhibited a clear response to X-ray irradiation. Especially Li{sub 2}B{sub 4}O{sub 7}:Cu presented a good glow curve in all kind of doses. The experimental results showed that this could have good potential applications in radiation dosimetry. The order of kinetics (b), frequency factor (s) and activation energy (E) or the trapping parameters were calculated using peak shape method. (Author)

  15. Patterns of flavor signals in supersymmetric models

    Energy Technology Data Exchange (ETDEWEB)

    Goto, T. [KEK National High Energy Physics, Tsukuba (Japan)]|[Kyoto Univ. (Japan). YITP; Okada, Y. [KEK National High Energy Physics, Tsukuba (Japan)]|[Graduate Univ. for Advanced Studies, Tsukuba (Japan). Dept. of Particle and Nucelar Physics; Shindou, T. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[International School for Advanced Studies, Trieste (Italy); Tanaka, M. [Osaka Univ., Toyonaka (Japan). Dept. of Physics

    2007-11-15

    Quark and lepton flavor signals are studied in four supersymmetric models, namely the minimal supergravity model, the minimal supersymmetric standard model with right-handed neutrinos, SU(5) supersymmetric grand unified theory with right-handed neutrinos and the minimal supersymmetric standard model with U(2) flavor symmetry. We calculate b{yields}s(d) transition observables in B{sub d} and B{sub s} decays, taking the constraint from the B{sub s}- anti B{sub s} mixing recently observed at Tevatron into account. We also calculate lepton flavor violating processes {mu} {yields} e{gamma}, {tau} {yields} {mu}{gamma} and {tau} {yields} e{gamma} for the models with right-handed neutrinos. We investigate possibilities to distinguish the flavor structure of the supersymmetry breaking sector with use of patterns of various flavor signals which are expected to be measured in experiments such as MEG, LHCb and a future Super B Factory. (orig.)

  16. Formation and annealing of boron-oxygen defects in irradiated silicon and silicon-germanium n{sup +}–p structures

    Energy Technology Data Exchange (ETDEWEB)

    Makarenko, L. F. [Belarusian State University, Minsk (Belarus); Lastovskii, S. B.; Korshunov, F. P. [Scientific-Practical Materials Research Centre of NAS of Belarus (Belarus); Moll, M. [CERN, Geneva (Switzerland); Pintilie, I. [National Institute of Materials Physics, Magurele (Romania); Abrosimov, N. V. [Leibniz Institute for Crystal Growth, Berlin (Germany)

    2014-02-21

    New findings on the formation and annealing of interstitial boron-interstitial oxygen complex (B{sub i}O{sub i}) in p-type silicon are presented. Different types of n+−p structures irradiated with electrons and alpha-particles have been used for DLTS and MCTS studies. Electronic excitation essentially changes the formation rate of B{sub i}O{sub i}. It has been found that the increase of oxygen content slows the B{sub i}O{sub i} annealing rate down. The activation energy of the B{sub i}O{sub i} dissociation has been determined and it was found that germanium doping does not change the activation energy.

  17. On current termination in rotamak discharges

    Energy Technology Data Exchange (ETDEWEB)

    Donaldson, N.; Euripides, P.; Jones, I.R.; Xu, S. [Flinders Univ. of South Australia, Bedford Park, SA (Australia). School of Physical Sciences

    1995-03-01

    A new series of rotamak experiments conducted in a 50 litre spherical pyrex discharge vessel is described. An analysis of the results, together with that of previous results from a smaller, 10 litre vessel, provides an explanation for the current termination phenomenon which is such a noteworthy and characteristic feature of all rotamak discharges studied to date. It is shown that the amplitude of the applied rotating magnetic field, B{sub {omega}}, has to be greater than a certain critical value, B{sub {omega}}{sup crit}, for the rotamak discharge to be maintained. Provided B{sub {omega}} {>=} B{sub {omega}}{sup crit}, the properties of the discharge are then determined by the behaviour of the circuit used to couple the RF generators to the plasma load. The conditions necessary for the production of a compact toroidal magnetic configuration are presented. (author).

  18. CP violation and B{sup 0}-(B{sup 0})-bar mixing

    Energy Technology Data Exchange (ETDEWEB)

    Aleksan, R. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee

    1996-01-01

    The status of CP violation and B{sup 0}-(B{sup 0})-bar mixing is given and the subsequent constraints in the framework of the Standard Model are discussed. Recent result on CP violation in the kaon system and related topics are reviewed, including the status of T violation and the tests of the CPT symmetry. The results on B{sup 0}-(B{sup 0})-bar mixing are presented followed by the studies on B{sub d}{sup 0}-(B{sub d}{sup 0})-bar and B{sub s}{sup 0}-(B{sub s}{sup 0})-bar oscillations. Finally, the prospects of progress on understanding CP violation are discussed in framework of the new projects expected to produce results at the turn of the century. (author). 76 refs.

  19. $B$ mixing and lifetimes at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Ceballos, G.; Piedra, J.

    2006-04-01

    The Tevatron collider at Fermilab provides a very rich environment for the study of b-hadrons. Both the D0 and CDF experiments have collected a sample of about 1 fb{sup -1}. they report results on three topics: b-hadron lifetimes, polarization amplitudes and the decay width difference in B{sub s}{sup 0} {yields} J/{psi}{phi}, and B{sub s}{sup 0} mixing.

  20. Structural studies on A-cation-deficient perovskite-related phases. I. ThNb/sub 4/O/sub 12/. Thorium/vacancy ordering in slow-cooled samples

    Energy Technology Data Exchange (ETDEWEB)

    Alario-Franco, M.A. (Universidad Complutense de Madrid (Spain). Facultad de Ciencias Quimicas); Grey, I.E.; Joubert, J.C.; Vincent, H. (Centre National de la Recherche Scientifique, 38 - Grenoble (France)); Labeau, M. (Institut National Polytechnique, 38 - Grenoble (France))

    1982-03-01

    The A-cation-deficient perovskite, Thsub(0.25)NbO/sub 3/, i.e. ThNb/sub 4/O/sub 12/, when slowly cooled from the melt, presents an interesting hierachy of ordering phenomena. The associated diffraction effects have been studied with electron microscopy/diffraction and X-ray diffraction techniques. Three main types of ordering processes occur, with different degrees of long-range order. Independent models for thorium/vacancy ordering and octahedral tilts have been refined with the intensities of the corresponding groups of satellites measured from precession photographs. The complete model for ThNb/sub 4/O/sub 12/ can be described in the unit cell 3..sqrt..2asub(p) x ..sqrt..2bsub(p) x 4csub(p), P2mm. The superlattice reflections arising from the octahedral tilts are split into groups of four satellites in the form of crosses, owing to microdomain formation in ThNb/sub 4/O/sub 12/, with domain boundaries parallel to (100)sub(p) and (010)sub(p) and with average widths of approximately25 A.

  1. A study of the efficiency of different spectrochemical buffers applied to the uranium ore analysis; Estudio de la eficiencia de diversos reguladores espectroqimicos aplicados al analisis de minerales de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Roca, M.; Diaz Guerra, J. P.

    1981-07-01

    A direct-reading emission spectroscopy method allowing the determination of Al, Ca, Fe, Mg, Mn, Na, P, Si and Ti in geological materials, that are of interest for the prospecting and recovery of uranium, is proposed. Direct-current are between graphite electrodes Is used as the excitation source. Efficiency of Ag{sub 2}O, BaCO{sub 3}, Bi{sub 2}O{sub 3}, CuF{sub 2}, CuO, Ga{sub 2}0{sub 3}, Ge0{sub 2}, graphite, K{sub 2}CO{sub 3}, H{sub 2}B{sub 4}O{sub 7}, Li{sub 2}CO{sub 3}, Ni, PbS, Sb{sub 2}o{sub 4} , SrC0{sub 3}, Ti{sub 2}O{sub 3} and ZnO as spectrochemical buffers has been studied. It has been inferred that through a sample dilution with Li{sub 2}CO{sub 3}, SrC0{sub 3} and graphite powder in the rations 1:10:10:20, respectively, the highest reduction of the matrix effects is achieved. Phosphorus determination Is better performed with PbS as spectrochemical buffer Instead of the indicated above. The action of the selected compounds Is completed by using Co, In, Li and Sr as internal standards, and, as a whole, satisfactory accuracy and reproducibility are attained. (Author) 7 refs.

  2. Magnetic susceptibilities and anisotropy studies of holmium pyrogermanate (Ho{sub 2}Ge{sub 2}O{sub 7}) crystal

    Energy Technology Data Exchange (ETDEWEB)

    Jana, S.; Ghosh, D. [Indian Association for the Cultivation of Science, Calcutta (India). Dept. of Solid State Physics; Wanklyn, B.M. [Clarendon Laboratory, University of Oxford, Oxford (United Kingdom)

    1998-03-01

    Experimental results of the magnetic susceptibilities (K {sub parallel}, K {sub perpendicular} {sub to}) and the anisotropy (K {sub perpendicular} {sub to} -K {sub parallel} ={Delta}K) of a single crystal of holmium pyrogermanate between 300 and 27 K are reported for the first time. At 300 K, {Delta}K is 4835 x 10{sup -6} emu/mol (being 10% of the mean susceptibility anti K) but at 27 K it increases by 144 times, becoming 88% of anti K. Crystal field (CF) analysis of the results was made considering D{sub 5h} site symmetry. The observed data were best fitted with CF parameters B{sub 20}=-150; B{sub 20}=300; B{sub 60}=-400; B{sub 65}=1500 (all in cm{sup -1}). Using the ground CF energy pattern, Schottky specific heat and the hyperfine splittings of the ground and first nuclear levels of {sup 165}Ho in the pyrogermanate host were calculated. The values of quadrupolar splittings of ground and first nuclear states were found to be 28.15 x 10{sup -4} and 33.42 x 10{sup -4} cm{sup -1}, respectively at 1 K. Moessbauer spectra are expected to show 12 transition lines. (orig.) 40 refs.

  3. Structure study and properties of rare earth-rich glassed for the conditioning of nuclear waste; Etude des caracteristiques structurales et des proprietes de verres riches en terres rares destines au confinement des produits de fission et elements a vie longue

    Energy Technology Data Exchange (ETDEWEB)

    Bardez, I

    2004-11-15

    A new nuclear glass composition, able to immobilize highly radioactive liquid wastes from high burn-up UO{sub 2} fuel, was established and its structure studied. The composition of the selected rare earth-rich glass is (molar %): 61.79 SiO{sub 2} - 8.94 B{sub 2}O{sub 3} - 3.05 Al{sub 2}O{sub 3} - 14.41 Na{sub 2}O - 6.32 CaO - 1.89 ZrO{sub 2} - 3.60 RE{sub 2}O{sub 3} (with RE = La, Ce, Pr and Nd) The aim of this study was to determine the local environment of the rare earth in this glass and also to glean information about the effect of glass composition on the rare earth neighbouring (influence of Si, B, Al, Na and Ca contents). To this end, several series of glasses, prepared from the baseline glass, were studied by different characterisation methods such as EXAFS spectroscopy at the neodymium L{sub III}-edge, optical absorption spectroscopy, Raman spectroscopy and {sup 29}Si, {sup 27}Al and {sup 11}B MAS-NMR. By coupling all the results obtained, several hypotheses about the nature of the rare earth neighbouring in the glass were proposed. (author)

  4. Effect of addition of tartaric acid on synthesis of boron carbide powder from condensed boric acid–glycerin product

    Energy Technology Data Exchange (ETDEWEB)

    Tahara, Naoki; Kakiage, Masaki, E-mail: kakiage@apc.saitama-u.ac.jp; Yanase, Ikuo; Kobayashi, Hidehiko

    2013-10-05

    Highlights: •B{sub 4}C powder was synthesized from a condensed H{sub 3}BO{sub 3}-glycerin product with tartaric acid added. •A precursor consisting of B{sub 2}O{sub 3} and carbon was prepared by the thermal decomposition in air. •The precursors had a three-dimensional bicontinuous B{sub 2}O{sub 3}/carbon network structure. •The dispersion state became more homogeneous and finer with the addition of tartaric acid. •The complete formation of B{sub 4}C powder was achieved at 1250 °C within a shorter heat treatment time. -- Abstract: The effect of the addition of tartaric acid on the synthesis of boron carbide (B{sub 4}C) powder from a condensed boric acid (H{sub 3}BO{sub 3})–glycerin product was investigated in this study. The condensed product was prepared by dehydration condensation after directly mixing equimolar amounts of H{sub 3}BO{sub 3} and glycerin with the addition of 0–50 mol% tartaric acid (based on glycerin), which was followed by thermal decomposition in air to obtain a precursor powder from which excess carbon had been eliminated. The dispersion state of the boron oxide (B{sub 2}O{sub 3}) and carbon components in the precursor prepared from the condensed product with 25 mol% tartaric acid added was finer than that without tartaric acid added, in which both precursors had a three-dimensional bicontinuous B{sub 2}O{sub 3}/carbon network structure. The complete formation of crystalline B{sub 4}C powder was achieved at 1250 °C within a shorter heat treatment time for the precursor with a fine dispersion state. The synthesized B{sub 4}C powders became fine owing to the increased number of nucleation sites.

  5. Use of Li.sub.2[B.sub.12H.sub.12] salt to absorb water into polymers

    Energy Technology Data Exchange (ETDEWEB)

    Eastwood, Eric A.; Bowen, III, Daniel E.

    2016-08-30

    Methods of adjusting the properties of a composition are provided. The compositions comprise a polymer-containing matrix and a filler comprising a hygroscopic salt. Preferred such salts comprise a cage compound selected from the group consisting of borane cage compounds, carborane cage compounds, metal complexes thereof, residues thereof, mixtures thereof, and/or agglomerations thereof, where the cage compound is not covalently bound to the matrix polymer.

  6. Study of rice. gamma. -irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lien, J.J.; Chau, R.S.; Chen, S.C.; Chu, S.L.; Fu, Y.K.; Fang, C.K.; Fu, Y.H.

    1981-03-01

    The purpose of this experiment was to investigate whether the /sup 60/Co gamma-irradiated milled rice packed in economic and practical sealed bags could be preserved in common granaries in Taiwan for more than one year rather than slightly over one month without quality deterioration. As a result of this experiment we found that during the preservation of over a period of 18 months, the contents, such as moisture, ash, protein and fiber, of Tainan-5 Bon-Lai (Japonica Type) rice irradiated with 20 and 40 krad doses were quite stable, whereas reducing sugar showed slight fluctuations but did not vary significantly either. The fat, vitamin B/sub 1/ and niacin contents were found being reduced, while the increase in fatty acid content was an inevitable phenomenon along with the proceeding of the preservation.

  7. Developement of a same-side kaon tagging algorithm of B^0_s decays for measuring delta m_s at CDF II

    Energy Technology Data Exchange (ETDEWEB)

    Menzemer, Stephanie; /Heidelberg U.

    2006-06-01

    The authors developed a Same-Side Kaon Tagging algorithm to determine the production flavor of B{sub s}{sup 0} mesons. Until the B{sub s}{sup 0} mixing frequency is clearly observed the performance of the Same-Side Kaon Tagging algorithm can not be measured on data but has to be determined on Monte Carlo simulation. Data and Monte Carlo agreement has been evaluated for both the B{sub s}{sup 0} and the high statistics B{sup +} and B{sup 0} modes. Extensive systematic studies were performed to quantify potential discrepancies between data and Monte Carlo. The final optimized tagging algorithm exploits the particle identification capability of the CDF II detector. it achieves a tagging performance of {epsilon}D{sup 2} = 4.0{sub -1.2}{sup +0.9} on the B{sub s}{sup 0} {yields} D{sub s}{sup -} {pi}{sup +} sample. The Same-Side Kaon Tagging algorithm presented here has been applied to the ongoing B{sub s}{sup 0} mixing analysis, and has provided a factor of 3-4 increase in the effective statistical size of the sample. This improvement results in the first direct measurement of the B{sub s}{sup 0} mixing frequency.

  8. Effects of chlorophyll and chlorophyllin on low-dose aflatoxin B1 pharmacokinetics in human volunteers: A pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Jubert, C; Mata, J; Bench, G; Dashwood, R; Pereira, C; Tracewell, W; Turteltaub, K; Williams, D; Bailey, G

    2009-04-20

    Chlorophyll (Chla) and chlorophyllin (CHL) were shown previously to reduce carcinogen bioavailability, biomarker damage, and tumorigenicity in trout and rats. These findings were partially extended to humans (Proc Natl Acad Sci USA 98, 14601-14606 (2001)), where CHL reduced excretion of aflatoxin B{sub 1} (AFB{sub 1})-DNA repair products in Chinese unavoidably exposed to dietary AFB{sub 1}. However, neither AFB{sub 1} pharmacokinetics nor Chla effects were examined. We conducted a small unblinded crossover study to establish AFB{sub 1} pharmacokinetic parameters in human volunteers, and to explore possible effects of CHL or Chla co-treatment on those parameters. For protocol 1, fasted subjects received an IRB-approved dose of 14C-AFB{sub 1} (30 ng, 5 nCi) by capsule with 100 ml water, followed by normal eating and drinking after hr 2. Blood and cumulative urine samples were collected over 72 hr, and {sup 14}C-AFB{sub 1} equivalents were determined by Accelerator Mass Spectrometry. Protocols 2 and 3 were similar except capsules also contained 150 mg of purified Chla, or CHL, respectively. All protocols were repeated 3 times for each of three volunteers. The study revealed rapid human AFB{sub 1} uptake (plasma ka 5.05 {+-} 1.10 hr-1, Tmax 1.0 hr) and urinary elimination (95% complete by 24 hr) kinetics. Chla and CHL treatment each significantly impeded AFB{sub 1} absorption and reduced Cmax and AUC's (plasma and urine) in one or more subjects. These initial results provide AFB{sub 1} pharmacokinetic parameters previously unavailable for humans, and suggest that Chla or CHL co-consumption may limit the bioavailability of ingested aflatoxin in humans, as they do in animal models.

  9. Raman and infrared studies of the Sharp 890 cm{sup -1} mode in organic superconductors.

    Energy Technology Data Exchange (ETDEWEB)

    Eldridge, J. E.; Lin, Y.; Schlueter, J. A.; Wang, H. H.; Kini, A. M.

    2000-11-28

    Raman and infrared spectra of several organic superconductors are presented, showing some unusual behaviors of a sharp line at 890 cm{sup {minus}} in both spectra. These include a frequency shift below T{sub c}, a positive deuterium isotope shift, frequency softening at low temperatures and sensitivity to lattice superstructure. It is proposed that either the ion or the neutral molecule has a distortion with a strong v{sub 60}(B{sub 3g}) mode component.

  10. Multicompartmental study of fluorine-18 altanserin binding to brain 5HT[sub 2] receptors in humans using positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Biver, F. (Psychiatry Dept., Erasme Hospital, Free Univ. of Brussels (Belgium) PET-Biomedical Cyclotron Unit, Erasme Hospital, Free Univ. of Brussels (Belgium)); Goldman, S. (PET-Biomedical Cyclotron Unit, Erasme Hospital, Free Univ. of Brussels (Belgium)); Luxen, A. (PET-Biomedical Cyclotron Unit, Erasme Hospital, Free Univ. of Brussels (Belgium)); Monclus, M. (PET-Biomedical Cyclotron Unit, Erasme Hospital, Free Univ. of Brussels (Belgium)); Forestini, M. (PET-Biomedical Cyclotron Unit, Erasme Hospital, Free Univ. of Brussels (Belgium)); Mendlewicz, J. (Psychiatry Dept., Erasme Hospital, Free Univ. of Brussels (Belgium)); Lotstra, F. (Psychiatry Dept., Erasme Hospital, Free Univ. of Brussels (Belgium))

    1994-09-01

    Serotoninergic type 2 (5HT[sub 2]) receptors have been implicated in the regulation of many brain functions in humans and may play a role in several neurological and psychiatric diseases. Fluorine-18 altanserin has been proposed as a new radiotracer for the study of 5HT[sub 2] receptors by PET because of its high affinity for 5HT[sub 2] receptors (Ki: 0.13 nM) and its good specificity in in vitro studies. Dynamic PET studies were carried out in 12 healthy volunteers after intravenous injection of 0.1 mCi/kg [[sup 18]F] altanserin. Ninety minutes after injection, we observed mainly cortical binding. Basal ganglia and cerebellum showed very low uptake and the frontal cortex to cerebellum ratio was about 3. To evaluate the quantitative distribution of this ligand in the brain, we used two different methods of data analysis: a four-compartment model was used to achieve quantitative evaluation of rate constants (K[sub 1] and k[sub 2] through k[sub 6]) by non-linear regression, and a multiple-time graphical analysis technique for reversible binding was employed for the measurement of k[sub 1]/k[sub 2] and k[sub 3]/k[sub 4] ratios. Using both methods, we found significant differences in binding capacity (estimated by k[sub 3]/k[sub 4] = B[sub max]/K[sub d]) between regions, the values increasing as follows: occipital, limbic, parietal, frontal and temporal cortex. After correction of values obtained by the graphical method for the existence of non-specific binding, results generated by the two methods were consistent. (orig.)

  11. Effect of Mg/B{sub 2}O{sub 3} molar ratio and furnace temperature on the phase evaluation and morphology of SiC–B{sub 4}C nanocomposite prepared by MASHS method

    Energy Technology Data Exchange (ETDEWEB)

    Roghani, Hamed [Semiconductor Department, Materials and Energy Research Center, Karaj (Iran, Islamic Republic of); Tayebifard, Seyed Ali, E-mail: a_tayebifard@yahoo.com [Semiconductor Department, Materials and Energy Research Center, Karaj (Iran, Islamic Republic of); Kazemzadeh, Asghar [Semiconductor Department, Materials and Energy Research Center, Karaj (Iran, Islamic Republic of); Nikzad, Leila [Ceramic Department, Materials and Energy Research Center, Karaj (Iran, Islamic Republic of)

    2015-07-01

    In this study, SiC–B{sub 4}C nanocomposite has been synthesized in situ successfully by Mechanical activated combustion synthesis method (MASHS). Initially Si, C, B{sub 2}O{sub 3} and Mg powders as raw materials were weighed according to different molar ratio of Mg to B{sub 2}O{sub 3}. In next step theses materials were milled in a planetary mill under Ar atmosphere. The synthesis step was performed in a tube furnace equipped with controlled atmosphere system. The different furnace temperature was investigated on the phase synthesis and morphology of the products. The specimens in the various steps were studied by XRD analysis for evaluation of the phase compositions and calculation of the average crystallite size of them. The morphology of synthesized products was investigated by scanning and transmission electron microscopes (SEM&TEM). The final product contains main phases MgO, B{sub 4}C and SiC. Also, In this sample byproducts were characterized such as Mg{sub 3}B{sub 2}O{sub 6}, Mg{sub 2}B{sub 2}O{sub 5} and remaining carbon. XRD pattern of synthesized sample showed the considerable effect of increasing Mg to B{sub 2}O{sub 3} molar ratio on reducing the amount of Mg{sub 3}B{sub 2}O{sub 6}, Mg{sub 2}B{sub 2}O{sub 5} and remaining carbon. SiC–B{sub 4}C composite was synthesized with more homogenous morphology by reducing the furnace temperature from 1000 to 900 °C, but reduction of temperature up to 800 °C give rise to uncompleted reaction whereas some unreacted Si remains. Average crystallite sizes of optimal sample were calculated 10.5 and 8 nm for SiC and B{sub 4}C respectively. These values are consisted of the TEM results somehow while grain size was less than 70 nm. Also SEM observation showed fine grains with sizes falling in the nanometer range. - Graphical abstract: Display Omitted - Highlights: • Composite prepared by combustion synthesis method in system of Si, C, B{sub 2}O{sub 3} and Mg. • More than stoichiometric Mg/B{sub 2}O{sub 3

  12. Boron neutron capture therapy (BNCT) inhibits tumor development from precancerous tissue: An experimental study that supports a potential new application of BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Monti Hughes, A.; Heber, E.M. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina); Pozzi, E. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina); Department of Research and Production Reactors, Ezeiza Atomic Center, CNEA, Buenos Aires (Argentina); Nigg, D.W. [Idaho National Laboratory, Idaho Falls, Idaho (United States); Calzetta, O.; Blaumann, H.; Longhino, J. [Department of Nuclear Engineering, Bariloche Atomic Center, CNEA, Rio Negro (Argentina); Nievas, S.I. [Department of Chemistry, CNEA, Buenos Aires (Argentina); Aromando, R.F. [Department of Oral Pathology, Faculty of Dentistry, University of Buenos Aires, Buenos Aires (Argentina); Itoiz, M.E. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina); Department of Oral Pathology, Faculty of Dentistry, University of Buenos Aires, Buenos Aires (Argentina); Trivillin, V.A. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina); Schwint, A.E. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina)], E-mail: schwint@cnea.gov.ar

    2009-07-15

    We previously demonstrated the efficacy of boron neutron capture therapy (BNCT) mediated by boronophenylalanine (BPA), GB-10 (Na{sub 2}{sup 10}B{sub 10}H{sub 10}) and (GB-10+BPA) to control tumors, with no normal tissue radiotoxicity, in the hamster cheek pouch oral cancer model. Herein we developed a novel experimental model of field-cancerization and precancerous lesions (globally termed herein precancerous tissue) in the hamster cheek pouch to explore the long-term potential inhibitory effect of the same BNCT protocols on the development of second primary tumors from precancerous tissue. Clinically, second primary tumor recurrences occur in field-cancerized tissue, causing therapeutic failure. We performed boron biodistribution studies followed by in vivo BNCT studies, with 8 months follow-up. All 3 BNCT protocols induced a statistically significant reduction in tumor development from precancerous tissue, reaching a maximum inhibition of 77-100%. The inhibitory effect of BPA-BNCT and (GB-10+BPA)-BNCT persisted at 51% at the end of follow-up (8 months), whereas for GB-10-BNCT it faded after 2 months. Likewise, beam-only elicited a significant but transient reduction in tumor development. No normal tissue radiotoxicity was observed. At 8 months post-treatment with BPA-BNCT or (GB-10+BPA)-BNCT, the precancerous pouches that did not develop tumors had regained the macroscopic and histological appearance of normal (non-cancerized) pouches. A potential new clinical application of BNCT would lie in its capacity to inhibit local regional recurrences.

  13. High pressure study of high-temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Souliou, Sofia-Michaela

    2014-09-29

    The current thesis studies experimentally the effect of high external pressure on high-T{sub c} superconductors. The structure and lattice dynamics of several members of the high-T{sub c} cuprate and Fe-based superconductors families were investigated by means of Raman spectroscopy and X-ray diffraction under well-controlled, hydrostatic high pressure and low temperature conditions. The lattice dynamics of the high-T{sub c} superconductor YBa{sub 2}Cu{sub 3}O{sub 6+x} have been investigated systematically by Raman spectroscopy as a function of doping (x = 0.95, 0.75, 0.60, 0.55, and 0.45) and external pressure. Under ambient pressure conditions, in addition to the Raman modes expected from group theory, we observe new Raman active phonons upon cooling the underdoped samples, at temperatures well above the superconducting transition temperature. The doping dependence and the onset temperatures of the new Raman features suggest that they are associated with the incommensurate charge density wave (CDW) state recently discovered in underdoped cuprates using synchrotron X-ray scattering techniques. Under high pressure conditions (from 2 to 12 GPa), our Raman measurements on highly ordered underdoped YBa{sub 2}Cu{sub 3}O{sub 6.55} samples do not show any of the new Raman phonons seen at ambient pressure. High pressure and low temperature Raman measurements have been performed on the underdoped superconductor YBa{sub 2}Cu{sub 4}O{sub 8}. A clear renormalization of some of the Raman phonons is seen below T{sub c} as a result of the changes in the phonon self-energy upon the opening of the superconducting gap, with the most prominent one being that of the B{sub 1g}-like buckling phonon mode. The amplitude of this renormalization strongly increases with pressure, resembling the effect of hole doping in YBa{sub 2}Cu{sub 3}O{sub 6+x}. At ∝ 10 GPa, the system undergoes a reversible pressure-induced structural phase transition to a non-centrosymmmetric structure (space group

  14. Comparative study of radiation shielding parameters for bismuth borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kaundal, Rajinder Singh, E-mail: rajinder_apd@yahoo.com [Department of Physics, School of Physical Sciences, Lovely Professional University, Phagwara, Punjab (India)

    2016-07-15

    Melt and quench technique was used for the preparation of glassy samples of the composition x Bi{sub 2}O{sub 3-}(1-x) B{sub 2}O{sub 3} where x= .05 to .040. XCOM computer program is used for the evaluation of gamma-ray shielding parameters of the prepared glass samples. Further the values of mass attenuation coefficients, effective atomic number and half value layer for the glassy samples have been calculated in the energy range from 1KeV to 100GeV. Rigidity of the glass samples have been analyzed by molar volume of the prepared glass samples. (author)

  15. A study of potential high band-gap photovoltaic materials for a two step photon intermediate technique in fission energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    1991-08-16

    A diamond synthesis chamber and an ion implanter have been constructed. Work has been rapidly progressing and diamond has been synthesized. There are five variables which affect the quality of diamond: (1) mass flow of methane, (2) mass flow of hydrogen, (3) filament temperature, (4) substrate temperature, and (5) substrate material. Enclosed are pictures and data of previous diamond growth experiments. Current work is focused on the conditions which produce the best quality diamond films. In this study, diamond films were deposited using a hot-filament CVD method with boron trioxide (B{sub 2}O{sub 3}) and diphosphorus pentoxide (P{sub 2}O{sub 5}) as the doping sources. P{sub 2}O{sub 5} is the only known effective phosphorus source for forming n-type semiconducting material. An RF generator has been made operation for epitaxial growth of AIN by the chemical vapor deposition method. In initial experiments with a graphite substrate, the RF generator heated the material to a temperature of 1100{degrees}C. A reactor which will use the RF generator has been built for AIN synthesis. The device should be assembled and tested by the end of August. A new process for fabricating platinum silicide photovoltaic cells has been developed. A diffused guard ring has been added to minimize leakage current. VUV to near IR capability has been developed for optical characterization. A microwave driven excimer lamp has been built and tested. Our previous work used a microwave source on an electron cyclotron heated ion source.

  16. Development and calibration of a same side kaon tagging algorithm and measurement of the B{sup 0}{sub s}- anti B{sup 0}{sub s} oscillation frequency Δm{sub s} at the LHCB experiment

    Energy Technology Data Exchange (ETDEWEB)

    Krocker, Georg Alexander

    2013-11-20

    This thesis presents a so called same side kaon tagging algorithm, which is used in the determination of the production flavour of B{sub s}{sup 0} mesons. The measurement of the B{sub s}{sup 0} - anti B{sub s}{sup 0} oscillation frequency Δm{sub s} in the decay B{sub s}{sup 0} → D{sub s}{sup -}π{sup +} is used to optimise and calibrate this algorithm. The presented studies are performed on a data set corresponding to an integrated luminosity of L=1.0 fb{sup -1} collected by the LHCb experiment in 2011. The same side kaon tagging algorithm, based on multivariant classifiers, is developed, calibrated and tested using a sample of about 26,000 reconstructed B{sub s}{sup 0} → D{sub s}{sup -}π{sup +} decays. An effective tagging power of ε{sub eff}=ε{sub tag}(1-2ω){sup 2}=2.42±0.39% is achieved. Combining the same side kaon tagging algorithm with additional flavour tagging algorithms results in a combined tagging performance of ε{sub eff} = ε{sub tag}(1 - 2ω){sup 2} = 5.13 ± 0.54%. With this combination, the B{sub s}{sup 0}- anti B{sub s}{sup 0} oscillation frequency is measured to be Δm{sub s}=17.745±0.022(stat.)±0.006(syst.) ps{sup -1}, which is the most precise measurement to date.

  17. Oxidation behaviour of boron carbide powder

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.Q. [College of Materials Science and Engineering, Nanjing University of Technology, New Model Road 5, Nanjing, Jiangsu 210009 (China)]. E-mail: Li.Yuanqiang@nims.go.jp; Qiu, T. [College of Materials Science and Engineering, Nanjing University of Technology, New Model Road 5, Nanjing, Jiangsu 210009 (China)

    2007-01-25

    Isothermal oxidation behaviour of powdered boron carbide (B{sub 4}C) with the fine (1.52 {mu}m), medium (22.5 {mu}m) and coarse (59.6 {mu}m) particle size has been studied in air ranging from 500 to 800 deg. C. The oxidation rate strongly depends on the particle size of boron carbide and temperature. The smaller particle size the higher oxidation rate of B{sub 4}C powder due to its larger surface area. When B{sub 4}C powder is oxidized in air, a B{sub 2}O{sub 3} glass film is formed on the surface of B{sub 4}C grain which retards the further oxidation reaction. The oxidation kinetics is approximately fitted to the diffusion-controlled rate law which can be described by the Jander's equation. The apparent activation energy for the fine-, medium- and coarse-B{sub 4}C powders is 209.4 {+-} 11.4, 212.7 {+-} 35.8 and 219.2 {+-} 45.3 kJ mol{sup -1}, respectively, slightly varying with the impurity content of B{sub 4}C powders. The type of rate law suggests that the diffusion of oxygen through the oxide layer is the rate-limiting step in the oxidation reactions. In addition, the change in the oxidation process at higher oxidation fraction might associate with the B{sub 2}O{sub 3} volatilization at higher temperatures.

  18. Study of crotoxin mechanism of action to mammary carcinomas and evaluation of its potential as a radiopharmaceutical; Estudo do mecanismo de acao da crotoxina em tumores mamarios e avaliacao do seu potenctial radiofarmaceutico

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Marina Bicalho

    2010-07-01

    Crotoxin, the main component of Crotalus durissus terrificus snake venom, has been studied since 1938. It is a natural polypeptidic complex with pharmacological potential because of its antitumoral properties which has attracted great interest for diagnosis and therapy of oncological diseases. However, Crotoxin mechanism of action and sites of specific interaction on tumor cells are still misunderstood. Breast cancer is the second most frequent type in the world and the most common cancer in women. About 30 to 60% of mammary tumors overexpress epidermal growth factor receptor (EGFR), a transmembrane protein related to cell proliferation. Since literature has reported that Crotoxin antitumoral effect is more potent on cells with EGFR overexpression the objectives of this work were to evaluate Crotoxin cytotoxic effects on mammary tumor cells human breast carcinoma (MCF-7) and Ehrlich tumor cells (murine ascitics carcinoma), and to investigate the specific molecular interaction of Crotoxin on Ehrlich tumor cells. Initially, Crotoxin was radiolabelled with iodine-125 ({sup 125}I-Crotoxin) and iodine-131 ({sup 131}I-Crotoxin). Saturation and competition assay were carried out to characterize Crotoxin in vitro interaction; Crotoxin biodistribution studies and singlephoton emission computed tomography (SPECT) of mice bearing Ehrlich tumor have been evaluated to describe in vivo interaction. Our results showed that Crotoxin presented cytotoxic effect against Ehrlich with DL{sub 50} in vitro (concentration of compound which is lethal for 50% of cells) of about one micromolar, but did not present significant effect against MCF-7. Morphological alterations characteristic of apoptosis suggests programmed cell death. {sup 125}I-Crotoxin interaction with Ehrlich tumor cells was saturable with approximately 70% specificity, and presented K{sub d}=24.98 nmol/L and B{sub max}=16,570 sites/cell for low affinity binding sites and K{sub d}=0.06 nmol/L and B{sub max}=210 sites

  19. Study the influence of zinc oxide addition on cobalt doped alkaline earth borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, F., E-mail: F.Ahmad378@yahoo.com [Department of Physics, Faculty of Science, Alazhar University (Girls Branch), Nasr City, Cairo (Egypt); Hassan Aly, E. [Department of Physics, Faculty of Science, Ain Shams University, P.O. Box 11566, Abbassia, Cairo (Egypt); Atef, M.; ElOkr, M.M. [Department of Physics, Faculty of Science, Alazhar University, Nasr City, Cairo (Egypt)

    2014-04-01

    Highlights: • The glassy system xZnO–(79.9−x)B{sub 2}O{sub 3}–20BaO–0.1Co{sub 3}O{sub 4} was prepared by a quenching method. • XRD patterns revealed that the amorphous nature of the present glasses matrix. • The results show that Zn{sup 2+} ions occupy both forming and modifying positions. • Optical parameters are reported as a function of ZnO content. - Abstract: The glasses of the composition 79.9B{sub 2}O{sub 3}–20BaO–0.1Co{sub 3}O{sub 4} doped with different concentrations of ZnO (5, 10, 15, 20, 25 and 30 mol%) were prepared using melt quenching technique. Various studies such as XRD, density, theoretical optical basicity, FT-IR and optical absorption have been carried out to study the role of ZnO on the physical and structural properties of the investigated system. Powder X-ray diffraction patterns confirmed the glassy nature of all the glassy samples. The density and molar volume of glassy samples showed opposite behavior to each other. An increment of the theoretical optical basicity with increasing ZnO content, which is due to an increase in the polarizability and a decrease in the single bond strength is observed. FT-IR analysis revealed that an increase in non-bridging oxygen’s (NBO’s) up to ZnO ⩽ 15 mol% and then a decrease at ZnO > 15 mol%. The results indicated that the Zn{sup 2+} ions are likely to occupy network modifier positions at a concentration of ZnO ⩽ 15 mol%. Above which these ions occupy network forming positions. From ultraviolet absorption edges calculations, the optical band gap energy and steepness parameter decrease whilst Urbach energy and refractive index increase by the addition of ZnO up to 15 mol% above which then the behavior follows reversal trend. The values of the crystal field strength and the interelectronic repulsion Racah parameter calculated from the optical transitions energies of cobalt doped glassy samples. All prepared samples exhibit blue color, indicating that mostly Co ions are acted upon

  20. Absorption and fluorescence studies of Sm{sup 3+} ions in lead containing sodium fluoroborate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Madhukar Reddy, C.; Dillip, G.R.; Mallikarjuna, K.; Zulifiqar Ali Ahamed, Sd. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Sudhakar Reddy, B. [Department of Physics, Sri Venkateswara Degree College, Kadapa 516003 (India); Deva Prasad Raju, B., E-mail: drdevaprasadraju@gmail.co [Department of Future Studies, Sri Venkateswara University, Tirupati 517 502 (India)

    2011-07-15

    Lead containing calcium zinc sodium fluoroborate glasses (LCZSFB) with molar composition of 20PbO+5CaO+5ZnO+10NaF+(60-x) B{sub 2}O{sub 3}+x Sm{sub 2}O{sub 3}, (x=0.1, 0.25, 0.5, 1.0 and 2.0 mol%) were prepared and investigated by the XRD, FTIR, optical absorption, photoluminescence and decay curve analysis. Judd-Ofelt theory was applied to the experimental oscillator strengths to evaluate the phenomenological J-O intensity parameters {Omega}{sub {lambda}} ({lambda}=2, 4 and 6). Using the J-O intensity parameters as well as from the emission and decay measurements, various radiative parameters such as transition probabilities (A{sub R}), radiative lifetimes ({tau}{sub R}), measured lifetimes ({tau}{sub m}), calculated branching ratios ({beta}{sub R}), measured branching ratios ({beta}{sub m}), effective bandwidth ({Delta}{lambda}{sub eff}) and stimulated emission cross sections {sigma}({lambda}{sub p}) have been calculated for the excited {sup 4}G{sub 5/2} luminescent level. The nature of decay curves of {sup 4}G{sub 5/2} level for different Sm{sup 3+} ion concentrations in all LCZSFB glasses has been analyzed and the lifetimes are noticed to decrease with increase of concentration. The concentration quenching has been attributed to the energy transfer through the cross-relaxation between Sm{sup 3+} ions. Based on these results, the utility of Sm{sup 3+} ions doped lead containing fluoroborate glasses as laser active materials in the visible region is discussed. - Highlights: {yields} In this study, we prepared LCZSFB glasses for different concentrations of Sm{sup 3+} ions. {yields} We characterize the prepared glasses with XRD, FTIR, absorption, emission and decay curve analysis. {yields} We used Judd-Ofelt theory to calculate oscillator strengths, J-O intensity parameters and different radiative properties. {yields} In this study, we conclude that Sm{sup 3+}-doped LCZSFB glasses are useful for the development of lasers and photonic devices in the visible region.

  1. 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

  2. In vitro and in vivo studies of ultrafine-grain Ti as dental implant material processed by ECAP

    Energy Technology Data Exchange (ETDEWEB)

    An, Baili; Li, Zhirui; Diao, Xiaoou [State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); National Clinical Research Center for Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); Shannxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); Xin, Haitao, E-mail: xhthmj@fmmu.edu.cn [State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); National Clinical Research Center for Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); Shannxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); Zhang, Qiang; Jia, Xiaorui; Wu, Yulu; Li, Kai [State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); National Clinical Research Center for Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); Shannxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi' an 710032 (China); Guo, Yazhou [School of Aeronautics, Northwestern Polytechnical University, Xi' an 710032 (China)

    2016-10-01

    The aim of this study was to investigate the surface characterization of ultrafine-grain pure titanium (UFG-Ti) after sandblasting and acid-etching (SLA) and to evaluate its biocompatibility as dental implant material in vitro and in vivo. UFG-Ti was produced by equal channel angular pressing (ECAP) using commercially pure titanium (CP-Ti). Microstructure and yield strength were investigated. The morphology, wettability and roughness of the specimens were analyzed after they were modified by SLA. MC3T3-E1 osteoblasts were seeded onto the specimens to evaluate its biocompatibility in vitro. For the in vivo study, UFG-Ti implants after SLA were embedded into the femurs of New Zealand rabbits. Osseointegration was investigated though micro-CT analysis, histological assessment and pull-out test. The control group was CP-Ti. UFG-Ti with enhanced mechanical properties was produced by four passes of ECAP in B{sub C} route at room temperature. After SLA modification, the hierarchical porous structure on its surface exhibited excellent wettability. The adhesion, proliferation and viability of cells cultured on the UFG-Ti were superior to that of CP-Ti. In the in vivo study, favorable osseointegration occurred between the implant and bone in CP and UFG-Ti groups. The combination intensity of UF- Ti with bone was higher according to the pull-out test. This study supports the claim that UFG-Ti has grain refinement with outstanding mechanical properties and, with its excellent biocompatibility, has potential for use as dental implant material. - Highlights: • Yield strength and Vickers hardness of Ti are improved significantly after it is grain-refined by ECAP process. • The hierarchical micro-porous structure with superior wettability could be formed on the surface of ECAP Ti after SLA. • The results in vitro exhibited excellent cell biocompatibility of UFG-Ti after sandblasting and acid-etching. • The osseointegration between UFG-Ti implant and surrounding bone could

  3. A study of lattice dynamics in iron-based superconductors by inelastic light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Um, Youngje

    2013-12-13

    After the discovery of high temperature (high T{sub c}) superconductivity in copper oxide-based materials (cuprates) in 1986, this phenomenon was a unique property of the cuprates for more than 20 years. The origin of high T{sub c} superconductivity is still under debate. In 2008, high T{sub c} superconductivity was discovered in iron-based compounds. This discovery presents new opportunities for the development of a fundamental understanding of high T{sub c} superconductivity. Density functional calculations indicate a weak electron-phonon coupling strength in iron-based superconductors and these suggest that superconductivity is not mediated by phonons. However, experimental report of a large isotope effect of the iron atoms on the superconductivity T{sub c} suggests that phonons play an important role in iron-based superconductors. Motivated by these findings, this thesis presents a Raman scattering study of the lattice dynamics of the iron-based superconductors Fe{sub 1+y}Te{sub 1-x}Se{sub x}, LiFeAs and NaFe{sub 1-x}Co{sub x}As as a function of chemical composition and temperature. In Fe{sub 1+y}Te{sub 1-x}Se{sub x}, an unconventional linewidth broadening of the c-axis polarized Fe phonon of B{sub 1g} symmetry is found with decreasing temperature, which indicates an unusual coupling between the phonon and iron excessinduced magnetic fluctuations in this compound. In LiFeAs, the Raman scattering data provide evidence for a weak electron-phonon coupling, which is consistent with non-phonon mediated Cooper pairing in this compound. In NaFe{sub 1-x}Co{sub x}As, upon cooling two features are observed: (i) an unconventional linewidth broadening of several phonons, which is indicative of spin fluctuation-phonon coupling, and (ii) a superconductivity-induced phonon lineshape renormalization, which can not be explained by standard model calculations.

  4. Core-level photoabsorption study of defects and metastable bonding configurations in boron nitride

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, I.; Jankowski, A.F.; Terminello, L.J. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    Boron nitride is an interesting material for technological applications and for fundamental solid state physics investigations. It is a compound isoelectronic with carbon and, like carbon can possess sp{sup 2} and sp{sup 3} bonded phases resembling graphite and diamond. BN crystallizes in the sp{sup 2}-bonded hexagonal (h-BN), rhombohedral (r-BN) and turbostratic phases, and in the sp{sup 3}-bonded cubic (c-BN) and wurtzite (w-BN) phases. A new family of materials is obtained when replacing C-C pairs in graphite with isoelectronic B-N pairs, resulting in C{sub 2}BN compounds. Regarding other boron compounds, BN is exceptional in the sense that it has standard two-center bonds with conventional coordination numbers, while other boron compounds (e.g. B{sub 4}C) are based on the boron icosahedron unit with three-center bonds and high coordination numbers. The existence of several allotropic forms and fullerene-like structures for BN suggests a rich variety of local bonding and poses the questions of how this affects the local electronic structure and how the material accommodates the stress induced in the transition regions between different phases. One would expect point defects to play a crucial role in stress accommodation, but these must also have a strong influence in the electronic structure, since the B-N bond is polar and a point defect will thus be a charged structure. The study of point defects in relationship to the electronic structure is of fundamental interest in these materials. Recently, the authors have shown that Near-Edge X-ray Absorption Fine Structure (NEXAFS) is sensitive to point defects in h-BN, and to the formation of metastable phases even in amorphous materials. This is significant since other phase identification techniques like vibrational spectroscopies or x-ray diffraction yield ambiguous results for nanocrystalline and amorphous samples. Serendipitously, NEXAFS also combines chemical selectivity with point defect sensitivity.

  5. Beautiful CP violation

    Energy Technology Data Exchange (ETDEWEB)

    Dunietz, I.

    1997-09-24

    CP violation is observed to date only in K{sup 0} decays and is parameterizable by a single quantity {epsilon}. Because it is one of the least understood phenomena in the Standard Model and holds a clue to baryogenesis, it must be investigated further. Highly specialized searches in K{sup 0} decays are possible. Effects in B decays are much larger. In addition to the traditional B{sub d} {yields} J/{psi}K{sub S}, {pi}{sup +}{pi}{sup {minus}} asymmetries, CP violation could be searched for in already existing inclusive B data samples. The rapid B{sub s}--{anti B}{sub s} oscillations cancel in untagged B{sub s} data samples, which therefore allow feasibility studies for the observation of CP violation and the extraction of CKM elements with present vertex detectors. The favored method for the extraction of the CKM angle {gamma} is shown to be unfeasible and a solution is presented involving striking direct CP violation in charged B decays. Novel methods for determining the B{sub s} mixing parameter {Delta}m are described without the traditional requirement of flavor-specific final states.

  6. Determining the CP-violating phase. gamma

    Energy Technology Data Exchange (ETDEWEB)

    Aleksan, R. (CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Physique des Particules Elementaires); Dunietz, I. (European Organization for Nuclear Research, Geneva (Switzerland). Theory Div.); Kayser, B. (National Science Foundation, Washington, DC (United States). Div. of Physics)

    1992-06-01

    The weak phase {gamma} is conventionally probed by the B{sub s}{yields}{rho}{sup 0} K{sub S} mode. The predicted rate is tiny. Even if a B{sub s}{yields}{rho}{sup 0}K{sub S} rate difference could be established, it would not be clear that sin 2{gamma} had been measured, because amplitudes with other weak phases may contribute significantly. Non-CP eigenstates, such as B{sub s}{yields}D{sub s}{sup {+-}}K{sup -+}, have a two-fold advantage over B{sub s}{yields}{rho}{sup 0}K{sub S}. Their rates are orders of magnitude above that for B{sub s}{yields}{rho}{sup 0}K{sub S}, and they probe the CP-violating phase {gamma}, without any contamination from other weak phases. Detailed time-dependent studies of non-CP eigenstates remove possible final-state phases and extract the weak phase {gamma}. (orig.).

  7. Structural and crystallisation study of a rare earth alumino borosilicate glass designed for nuclear waste confinement; Etude de la structure et du comportement en cristallisation d'un verre nucleaire d'aluminoborosilicate de terre rare

    Energy Technology Data Exchange (ETDEWEB)

    Quintas, A

    2007-09-15

    This work is devoted to the study of a rare earth alumino borosilicate glass, which molar composition is 61,81 SiO{sub 2} - 3,05 Al{sub 2}O{sub 3} - 8,94 B{sub 2}O{sub 3} - 14,41 Na{sub 2}O - 6,33 CaO - 1,90 ZrO{sub 2} - 3,56 Nd{sub 2}O{sub 3}, and envisaged for the immobilization of nuclear wastes originating from the reprocessing of high discharge burn up spent fuel. From a structural viewpoint, we investigated the role of the modifier cations on the arrangement of the glass network through different modifications of the glass composition: variation of the Na/Ca ratio and modification of the nature of the alkali and alkaline earth cations. The NMR and Raman spectroscopic techniques were useful to determine the distribution of modifier cations among the glass network and also to cast light on the competition phenomena occurring between alkali and alkaline earth cations for charge compensation of [AlO{sub 4}]{sup -} and [BO{sub 4}]{sup -} species. The neodymium local environment could be probed by optical absorption and EXAFS spectroscopies which enabled to better understand the insertion mode of Nd{sup 3+} ions among the silicate domains of the glass network. Concerning the crystallization behavior we were interested in how the glass composition may influence the crystallization processes and especially the formation of the apatite phase of composition Ca{sub 2}Nd{sub 8}(SiO{sub 4}){sub 6}O{sub 2}. In particular, this work underlined the important role of both alkaline earth and rare earth cations on the crystallization of the apatite phase. (author)

  8. A study of potential high band-gap photovoltaic materials for a two step photon intermediate technique in fission energy conversion. Progress report for year one, December 1, 1990--November 30, 1991

    Energy Technology Data Exchange (ETDEWEB)

    1991-08-16

    A diamond synthesis chamber and an ion implanter have been constructed. Work has been rapidly progressing and diamond has been synthesized. There are five variables which affect the quality of diamond: (1) mass flow of methane, (2) mass flow of hydrogen, (3) filament temperature, (4) substrate temperature, and (5) substrate material. Enclosed are pictures and data of previous diamond growth experiments. Current work is focused on the conditions which produce the best quality diamond films. In this study, diamond films were deposited using a hot-filament CVD method with boron trioxide (B{sub 2}O{sub 3}) and diphosphorus pentoxide (P{sub 2}O{sub 5}) as the doping sources. P{sub 2}O{sub 5} is the only known effective phosphorus source for forming n-type semiconducting material. An RF generator has been made operation for epitaxial growth of AIN by the chemical vapor deposition method. In initial experiments with a graphite substrate, the RF generator heated the material to a temperature of 1100{degrees}C. A reactor which will use the RF generator has been built for AIN synthesis. The device should be assembled and tested by the end of August. A new process for fabricating platinum silicide photovoltaic cells has been developed. A diffused guard ring has been added to minimize leakage current. VUV to near IR capability has been developed for optical characterization. A microwave driven excimer lamp has been built and tested. Our previous work used a microwave source on an electron cyclotron heated ion source.

  9. Ab initio study of the elastic properties of single and polycrystal TiO{sub 2}, ZrO{sub 2} and HfO{sub 2} in the cotunnite structure

    Energy Technology Data Exchange (ETDEWEB)

    Caravaca, M A; Mino, J C; Perez, V J [Departamento de Fisico-Quimica, Facultad de Ingenieria, UNNE, Avenida Las Heras 727, CP 3500, Resistencia (Argentina); Casali, R A; Ponce, C A [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales y Agrimensura UNNE, Avenida Libertad 5600, CP 3400, Corrientes (Argentina)

    2009-01-07

    In this work, we study theoretically the elastic properties of the orthorhombic (Pnma) high-pressure phase of IV-B group oxides: titania, zirconia and hafnia. By means of the self-consistent SIESTA code, pseudopotentials, density functional theory in the LDA and GGA approximations, the total energies, hydrostatic pressures and stress tensor components are calculated. From the stress-strain relationships, in the linear regime, the elastic constants C{sub ij} are determined. Derived elastic constants, such as bulk, Young's and shear modulus, Poisson coefficient and brittle/ductile behavior are estimated with the polycrystalline approach, using Voigt-Reuss-Hill theories. We have found that C{sub 11}, C{sub 22} and C{sub 33} elastic constants of hafnia and zirconia show increased strength with respect to the experimental values of the normal phase, P 2{sub 1}/c. A similar situation applies to titania if these constants are compared with its normal phase, rutile. However, shear elastic constants C{sub 44}, C{sub 55} and C{sub 66} are similar to the values found in the normal phase. This fact increases the compound anisotropy as well as its ductile behavior. The dependence of unit-cell volumes under hydrostatic pressures is also analyzed. P-V data, fitted to third-order Birch-Murnaghan equations of state, provide the bulk modulus B{sub 0} and its pressure derivatives B'{sub 0}. In this case, LDA estimations show good agreement with respect to recent measured bulk moduli of ZrO{sub 2} and HfO{sub 2}. Thermo-acoustic properties, e.g. the propagation speed of transverse, longitudinal elastic waves together with associated Debye temperatures, are also estimated.

  10. Raman active modes of NiSi crystal

    Energy Technology Data Exchange (ETDEWEB)

    Wan Li, E-mail: liwan_china@yahoo.com.c [Department of Physics, Wenzhou University (China); Tang Bo; Cheng Xinhong; Ren Yiming; Zhang Xuefei; Xu Dapeng; Luo Haijun; Huang Yunmi [Department of Physics, Wenzhou University (China)

    2009-08-01

    Raman scattering intensities of the NiSi Raman-active modes have been calculated with three Raman measurement configurations, which can be used for the symmetry assignment of the NiSi Raman peaks. Raman-active vibrations of the NiSi crystal have also been theoretically studied. Results show that the lattices with A{sub g} and B{sub 2g} modes vibrate only in the plane normal to the NiSi[0 1 0] direction while the lattices with B{sub 1g} and B{sub 3g} modes vibrate only along the NiSi[0 1 0] axis. Based on such study, the relationship between the anisotropic strain distribution in the NiSi thin film and the Raman peak shifts has been briefly discussed.

  11. Comparative study of frying to other cooking techniques influence on the nutritive value

    Directory of Open Access Journals (Sweden)

    Bognár, A.

    1998-08-01

    Full Text Available Frying is one of the oldest methods of food preparation. It improves the sensory quality of food by formation of aroma compounds, attractive colour, crust and texture. Undesirable changes involved are loss of nutritive quality e.g. due to degradation of heat - susceptible vitamins. The influence of common frying methods (frying in an oven, in a pan deep frying on cooking time and nutritive value of vegetables, potatoes, meat, poultry and fish is described and compared to other cooking methods (boiling, steaming, stewing. Frying of vegetables, potatoes and breaded meat, poultry and fish, no matter whether in a pan or by deep - frying, is associated with fat uptake (2 - 14 g per 100 g of raw food while non - breaded high fat food of animal origin loses fat during frying (2 - 30%. Data suggest that the fat quantity absorbed during frying increases up to a saturation limit which depends on the kind of food and on the amount of panade. Deep - fried meat, poultry and fish usually absorb less fat than meat, poultry and fish fried in a pan. The kind of fat had no essential influence on fat uptake. After frying of vegetable food and of breaded meat, poultry and fish, the content of protein, carbohydrates and minerals was nearly fully retained while boiling and steaming reduced the mineral content by 25-50%. In the majority of cases frying including deep frying also retained the vitamins B>1, B>2, B>6 and C better than boiling, steaming and stewing.

  12. Stability of superheavy elements around Z=120 probed by the study of their fission time obtained by the crystal blocking method; Stabilite d'elements superlourds au voisinage de Z=120 testee par l'etude de leurs temps de fission deduits par la methode du blocage cristallin

    Energy Technology Data Exchange (ETDEWEB)

    Laget, M

    2007-10-15

    While the existence of an island of stability beyond Z=110 is theoretically acquired, the location of this island ranges from Z=114 to Z=126 depending on models. In this work, the stability of super-heavy nuclei is probed through the study of their fission time. The chosen experimental method, the crystal blocking method, is sensitive to the presence of possible long time components in the fission time distribution which indicates a fission mechanism occurring after the formation of a compound nucleus. The blocking dips were therefore constituted for the various products of the reaction U{sup 238} + Ni (6.6 MeV/A) {yields} 120, the experimental set-up allowing us to clearly identify and select the reaction mechanisms. The comparison of the blocking dip constituted for quasi-elastic scattering events with the one obtained for the fission fragments of a Z=120, combined with the study of kinematical properties of these fission fragments, give evidences of the existence of very long fission times (> 10{sup -18} s) only compatible with a fusion-fission mechanism implying a non vanishing fission barrier height for Z=120. The second part outlines microscopic calculations of fission barrier heights, carried out in the framework of the finite temperature of the Hartree-Fock-Bogoliubov (HFB) theory. Because of the progressive vanishing of the pairing correlation with T, which happens differently at the ground state and at the top of the barrier, B{sub f} first grows until T {approx_equal} 0.8 MeV before dropping with T owing to shell-effects damping with temperature. (author)

  13. Polarized Raman spectroscopy study of NiSi film grown on Si(001) substrate

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Li; Ren, Yiming; Tang, Bo; Cheng, Xinhong; Zhang, Xuefei; Xu, Dapeng; Luo, Hijun; Huang, Yunmi [Wenzhou University, Department of Physics, Wenzhou (China)

    2009-11-15

    We report on the growth of NiSi film on Si(001) substrate with an orientation of NiSi[200]//Si[001]. Polarized Raman spectroscopy was used to assign the symmetry of the NiSi Raman peaks. Raman peaks at 213 cm{sup -1}, 295 cm{sup -1}, and 367 cm{sup -1} are assigned to be A{sub g} symmetry and peaks at 196 cm{sup -1}, and 254 cm{sup -1} are B{sub 3g} symmetry. (orig.)

  14. OH (1720 MHz) MASERS: A MULTIWAVELENGTH STUDY OF THE INTERACTION BETWEEN THE W51C SUPERNOVA REMNANT AND THE W51B STAR FORMING REGION

    Energy Technology Data Exchange (ETDEWEB)

    Brogan, C. L.; Hunter, T. R. [National Radio Astronomy Observatory, 520 Edgemont Rd, Charlottesville, VA 22903 (United States); Goss, W. M.; Chandler, C. J.; Claussen, M. J. [National Radio Astronomy Observatory, P.O. Box 0, Socorro, NM 87801 (United States); Richards, A. M. S. [Jodrell Bank Centre for Astrophysics, Turing Building, University of Manchester, Manchester M13 9PL (United Kingdom); Lazendic, J. S. [Monash University, Clayton, VIC 3800 (Australia); Koo, B.-C. [Astronomy Program, SEES, Seoul National University, Seoul 151-742 (Korea, Republic of); Hoffman, I. M., E-mail: cbrogan@nrao.edu [Wittenberg University, Springfield, OH 45501 (United States)

    2013-07-10

    We present a comprehensive view of the W51B H II region complex and the W51C supernova remnant (SNR) using new radio observations from the VLA, VLBA, MERLIN, JCMT, and CSO along with archival data from Spitzer, ROSAT, ASCA, and Chandra. Our VLA data include the first {lambda} = 400 cm (74 MHz) continuum image of W51 at high resolution (88''). The 400 cm image shows non-thermal emission surrounding the G49.2-0.3 H II region, and a compact source of non-thermal emission (W51B{sub N}T) coincident with the previously-identified OH (1720 MHz) maser spots, non-thermal 21 and 90 cm emission, and a hard X-ray source. W51B{sub N}T falls within the region of high likelihood for the position of TeV {gamma}-ray emission. Using the VLBA, three OH (1720 MHz) maser spots are detected in the vicinity of W51B{sub N}T with sizes of 60-300 AU and Zeeman effect magnetic field strengths of 1.5-2.2 mG. The multiwavelength data demonstrate that the northern end of the W51B H II region complex has been partly enveloped by the advancing W51C SNR and this interaction explains the presence of W51B{sub N}T and the OH masers. This interaction also appears in the thermal molecular gas which partially encircles W51B{sub N}T and exhibits narrow pre-shock ({Delta}v {approx} 5 km s{sup -1}) and broad post-shock ({Delta}v {approx} 20 km s{sup -1}) velocity components. RADEX radiative transfer modeling of these two components yield physical conditions consistent with the passage of a non-dissociative C-type shock. Confirmation of the W51B/W51C interaction provides additional evidence in favor of this region being one of the best candidates for hadronic particle acceleration known thus far.

  15. Mechanochemical synthesis of nanocrystalline Fe and Fe–B magnetic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, Majid; Ghasemi, Ali, E-mail: ali13912001@yahoo.com; Tavoosi, Majid

    2016-12-01

    Mechanochemical synthesis and magnetic characterization of nanocrystalline Fe and Fe–B magnetic alloys was the goal of this study. In this regard, different Fe{sub 2}O{sub 3}–B{sub 2}O{sub 3} powder mixtures with sufficient amount of CaH{sub 2} were milled in a planetary ball mill in order to produce nanocrystalline Fe, Fe{sub 95}B{sub 5} and Fe{sub 85}B{sub 15} alloys. The produced samples were characterized using X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The results showed that, nanocrystalline Fe, Fe{sub 95}B{sub 5} and Fe{sub 85}B{sub 15} alloys can be successfully synthesized by the reduction reaction of Fe{sub 2}O{sub 3} and B{sub 2}O{sub 3} with CaH{sub 2} during mechanical alloying. The structure of produced Fe{sub 95}B{sub 5} and Fe{sub 85}B{sub 15} alloys was a combination of Fe and Fe{sub 2}B phases with average crystallite sizes of about 15 and 10 nm, respectively. The produced nanocrystalline alloys exhibited soft magnetic properties with the coercivity and saturation of magnetization in the range of 170–240 Oe and 9–28 emu/g, respectively. Increasing the boron content has a destructive effect on soft magnetic properties of Fe–B alloys. - Highlights: • We study the mechanochemical synthesis of nanocrystalline boron, Fe and Fe–B alloys. • We study the reduction reaction of B{sub 2}O{sub 3}–CaH{sub 2} during milling. • We study the reduction reaction of Fe{sub 2}O{sub 3}–CaH{sub 2} during milling. • We study the reduction reaction of Fe{sub 2}O{sub 3}–B{sub 2}O{sub 3}–CaH{sub 2} during milling. • We study the effect of B on magnetic properties of nanocrystalline Fe–B alloys.

  16. Mechanical alloying of Fe-Ni based nanostructured magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Du, S.W. [School of Materials Engineering, Nanyang Technological University, B1k N4.1, Nanyang Ave., Singapore 639798 (Singapore); Ramanujan, R.V. [School of Materials Engineering, Nanyang Technological University, B1k N4.1, Nanyang Ave., Singapore 639798 (Singapore)]. E-mail: ramanujan@ntu.edu.sg

    2005-04-15

    Alloys with the composition Fe{sub 40}Ni{sub 38}B{sub 18}Mo{sub 4}, Fe{sub 49}Ni{sub 46}Mo{sub 5} and Fe{sub 42}Ni{sub 40}B{sub 18} were processed from elemental powders by mechanical alloying and the microstructure was studied by differential scanning calorimetry (DSC), X-ray diffractometer (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. Nanocrystalline fcc solid solution was achieved as a result of mechanical alloying in all three alloy compositions and the grain size reduced to nanoscale but lattice strain was introduced. Molybdenum was found to affect the products of mechanical alloying, specifically, the Fe{sub 3}B phase formed in the Fe{sub 42}Ni{sub 40}B{sub 18} alloy while no boride phase formed in the Fe{sub 40}Ni{sub 38}B{sub 18}Mo{sub 4} alloy. SEM studies indicated that the presence of boron was found to make the milling process easier. Elemental mapping by SEM as well as XRD results showed that molybdenum does not dissolve easily in the Fe-Ni solid solution produced by milling. The DSC results suggested that an amorphous structure together with nanocrystals was obtained in the Fe{sub 40}Ni{sub 38}B{sub 18}Mo{sub 4} and Fe{sub 42}Ni{sub 40}B{sub 18} alloys. A two-stage crystallization process was found in the Fe{sub 40}Ni{sub 38}B{sub 18}Mo{sub 4} and Fe{sub 42}Ni{sub 40}B{sub 18} alloys, the presence of boron was found to make amorphization easier. TEM investigations were consistent with these XRD and DSC results. Heat-treated samples of the Fe{sub 40}Ni{sub 38}B{sub 18}Mo{sub 4} and Fe{sub 42}Ni{sub 40}B{sub 18} alloys milled for 100 h showed that molybdenum inhibited the grain growth. The saturation magnetization of the heat-treated Fe{sub 40}Ni{sub 38}B{sub 18}Mo{sub 4} alloy milled for 100 h was stable, coercivity was reduced; on the other hand, the M {sub s} of heat-treated Fe{sub 42}Ni{sub 40}B{sub 18} alloy milled for 100 h decreased and the H {sub c} increased. This difference in magnetic

  17. Human Vitamin B12 Absorption and Metabolism are Measured by Accelerator Mass Spectrometry Using Specifically Labeled 14C-Cobalamin

    Energy Technology Data Exchange (ETDEWEB)

    Carkeet, C; Dueker, S R; Lango, J; Buchholz, B A; Miller, J W; Green, R; Hammock, B D; Roth, J R; Anderson, P J

    2006-01-26

    There is need for an improved test of human ability to assimilate dietary vitamin B{sub 12}. Assaying and understanding absorption and uptake of B{sub 12} is important because defects can lead to hematological and neurological complications. Accelerator mass spectrometry (AMS) is uniquely suited for assessing absorption and kinetics of {sup 14}C-labeled substances after oral ingestion because it is more sensitive than decay counting and can measure levels of carbon-14 ({sup 14}C) in microliter volumes of biological samples, with negligible exposure of subjects to radioactivity. The test we describe employs amounts of B{sub 12} in the range of normal dietary intake. The B{sub 12} used was quantitatively labeled with {sup 14}C at one particular atom of the DMB moiety by exploiting idiosyncrasies of Salmonellametabolism. In order to grow aerobically on ethanolamine, S. entericamust be provided with either pre-formed B{sub 12} or two of its precursors: cobinamide and dimethylbenzimidazole (DMB). When provided with {sup 14}C-DMB specifically labeled in the C2 position, cells produced {sup 14}C-B{sub 12} of high specific activity (2.1 GBq/mmol, 58 mCi/mmol) and no detectable dilution of label from endogenous DMB synthesis. In a human kinetic study, a physiological dose (1.5 mg, 2.2 KBq/59 nCi) of purified {sup 14}C-B{sub 12} was administered and showed plasma appearance and clearance curves consistent with the predicted behavior of the pure vitamin. This method opens new avenues for study of B{sub 12} assimilation.

  18. First-principles study of structural stabilities, elastic and electronic properties of transition metal monocarbides (TMCs) and mononitrides (TMNs)

    Energy Technology Data Exchange (ETDEWEB)

    Rached, H.; Rached, D.; Benalia, S. [Laboratoire des Matériaux Magnétiques, Faculté des Sciences, Université Djillali Liabès de Sidi Bel-Abbès, Sidi Bel-Abbès 22000 (Algeria); Reshak, A.H., E-mail: maalidph@yahoo.co.uk [Institute of Complex Systems, FFPW, CENAKVA, University of South Bohemia in CB, Nove Hrady 37333 (Czech Republic); Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia); Rabah, M. [Laboratoire des Matériaux Magnétiques, Faculté des Sciences, Université Djillali Liabès de Sidi Bel-Abbès, Sidi Bel-Abbès 22000 (Algeria); Khenata, R. [Laboratoire de Physique Quantique et de Modélisation Mathématique de la Matière (LPQ3M), université de Mascara, Mascara 29000 (Algeria); Bin Omran, S. [Department of Physics and Astronomy, Faculty of Science, King Saud University, Riyadh 11451 (Saudi Arabia)

    2013-12-16

    The structural stabilities, elastic and electronic properties of 5d transition metal mononitrides (TMNs) XN with (X = Ir, Os, Re, W and Ta) and 5d transition metal monocarbides (TMCs) XC with (X = Ir, Os, Re and Ta) were investigated using the full-potential linear muffin-tin orbital (FP-LMTO) method, in the framework of the density functional theory (DFT) within the local density approximation (LDA) for the exchange correlation functional. The ground state quantities such as the lattice parameter, bulks modulus and its pressure derivatives for the six considered crystal structures, Rock-salt (B1), CsCl (B2), zinc-blend (B3), Wurtzite (B4), NiAs (B8{sub 1}) and the tungsten carbides (B{sub h}) are calculated. The elastic constants of TMNs and TMCs compounds in its different stable phases are determined by using the total energy variation with strain technique. The elastic modulus for polycrystalline materials, shear modulus (G), Young's modulus (E), and Poisson's ratio (ν) are calculated. The Debye temperature (θ{sub D}) and sound velocities (v{sub m}) were also derived from the obtained elastic modulus. The analysis of the hardness of the herein studied compounds classifies OsN – (B4 et B8{sub 1}), ReN – (B8{sub 1}), WN – (B8{sub 1}) and OsC – (B8{sub 1}) as superhard materials. Our results for the band structure and densities of states (DOS), show that TMNs and TMCs compounds in theirs energetically and mechanically stable phase has metallic characteristic with strong covalent nature Metal–Nonmetal elements. - Highlights: • Structural stabilities, elastic, electronic properties of 5d TMNs XN are investigated. • 5d TMCs XC with (X = Ir, Os, Re and Ta) were investigated. • The ground state properties for the six considered crystal structure are calculated. • The elastic constants of TMNs and TMCs in its different stable phases are determined. • The elastic modulus for polycrystalline materials, G, E, and ν are calculated.

  19. Heavy pseudoscalar twist-3 distribution amplitudes within QCD theory in background fields

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Tao [Henan Normal University, College of Physics and Materials Science, Xinxiang (China); Wu, Xing-Gang [Chongqing University, Department of Physics, Chongqing (China); Huang, Tao [Chinese Academy of Sciences, Institute of High Energy Physics and Theoretical Physics Center for Science Facilities, Beijing (China); Fu, Hai-Bing [Guizhou Minzu University, School of Science, Guiyang (China)

    2016-09-15

    In this paper, we study the properties of the twist-3 distribution amplitude (DA) of the heavy pseudoscalars such as η{sub c}, B{sub c}, and η{sub b}. New sum rules for the twist-3 DA moments left angle ξ{sup n}{sub P} right angle {sub HP} and left angle ξ{sup n}{sub σ} right angle {sub HP} up to sixth order and up to dimension-six condensates are deduced under the framework of the background field theory. Based on the sum rules for the twist-3 DA moments, we construct a new model for the two twist-3 DAs of the heavy pseudoscalar with the help of the Brodsky-Huang-Lepage prescription. Furthermore, we apply them to the B{sub c} → η{sub c} transition form factor (f{sub +}{sup B{sub c}→η{sub c}}(q{sup 2})) within the light-cone sum rules approach, and the results are comparable with other approaches. It has been found that the twist-3 DAs φ{sup P}{sub 3;η{sub c}} and φ{sup σ}{sub 3;η{sub c}} are important for a reliable prediction of f{sub +}{sup B{sub c}→η{sub c}}(q{sup 2}). For example, at the maximum recoil region, we have f{sub +}{sup B{sub c}→η{sub c}}(0) = 0.674 ± 0.066, in which those two twist-3 terms provide ∝33 and ∝22% contributions. Also we calculate the branching ratio of the semi-leptonic decay B{sub c} → η{sub c}lν Br(B{sub c} → η{sub c}lν) = (9.31{sup +2.27}{sub -2.01}) x 10{sup -3}. (orig.)

  20. Hydrogenation disproportionation desorption and recombination (HDDR) studies on direct-reduced Nd{sub 15}Fe{sub 77{minus}x}B{sub 8}Ga{sub x} powders

    Energy Technology Data Exchange (ETDEWEB)

    Burkhardt, C.; Harris, I.R. [Univ. of Birmingham (United Kingdom). School of Metallurgy and Materials; Steinhorst, M. [Elektro-Thermit GmbH, Essen (Germany)

    1995-11-01

    Direct-reduced Nd-Fe-B powders with additions of 1.0% and 2.0% Ga were treated by the HDDR process at temperatures between 770 C and 900 C in order to optimize the processing parameters. The microstructures of the powders were investigated by scanning electron microscopy (SEM) on rotary forged Al bonded samples. The investigation of the magnetic properties was carried out on wax-bonded samples on a vibrating sample magnetometer (VSM). It was found that the direct-reduced Nd-Fe-B powders containing Ga additions show significantly increased intrinsic coercivities of up to 895 kA/m compared to those of the ternary alloy or those of powders with Zr additions. The remanence appears to be, for both Nd{sub 15}Fe{sub 76}B{sub 8}Ga{sub 1} and Nd{sub 15}Fe{sub 75}B{sub 8}Ga{sub 2}, relatively constant over a processing temperature range of {approximately}50 C with Nd{sub 15}Fe{sub 76}B{sub 8}Ga{sub 1} exhibiting higher values of up to 680 mT. The disproportionation time has a significant influence on the magnetic properties of the material, higher processing temperatures requiring shorter times in the disproportionated state, lower temperatures longer times. Under the conditions employed in these experiments, the HDDR treatment removes existing anisotropy in the as-received coarse grain material, thus leading to predominantly isotropic behavior.

  1. Characterization and study of the electrical and dielectric properties of SrBi{sub 4}Ti{sub 4}O{sub 15} (SBTi) added PbO and V{sub 2}O{sub 5} for radio frequency (RF) applications; Caracterizacao e estudo das propriedades eletricas e dieletricas do SrBi{sub 4}Ti{sub 4}O{sub 15} (SBTi) adicionado de PbO e V{sub 2}O{sub 5} para aplicacoes em radio frequencia (RF)

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues Junior, C.A.; Freitas, D.B.; Fernandes, T.S.M.; Sombra, A.S.B., E-mail: cauby@fisica.ufc.br [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Departamento de Engenharia de Teleinformatica; Silva, M.A.S. [Universidade Federal do Ceara (LOCEM/UFC), Fortaleza, CE (Brazil). Laboratorio de Telecomunicacoes e Ciencia e Engenharia de Materiais; Sales, J.C. [Universidade Estadual Vale do Acarau (UVA), Sobral, CE (Brazil)

    2011-07-01

    The objective of this work was to study the dielectric and electric properties in radio frequency (RF) of the compound SrBi{sub 4}Ti{sub 4}O{sub 15} (SBTi) added with PbO and V{sub 2}O{sub 5}. The SBT ceramic, perovskite with cation deficiency A{sub 5}B{sub 4}O{sub 15}, was prepared by the solid state reaction method and then added with PbO (0, 2, 5, 10 and 15% by weight) and with V{sub 2}O{sub 3} (in the range of 0.2 %, 5%, 10% and 15% by weight). The samples were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). A study based on Impedance Spectroscopy was also performed. X-ray analysis indicates that all samples have orthorhombic crystalline system and spatial group A21am. The quantitative phase analysis performed by the Rietveld refinement confirmed the crystal structure with net parameter a = 5.4400 Å, b = 5.4326 Å and c = 41.2169 Å. Scanning electron microscopy shows globular and crystal shaped grains, with a certain uniformity in the grain size that is very small, between 1 and 2 μm approximately. Dielectric properties: dielectric constant (K ') and dielectric loss (tang δ) were measured at room temperature in the 40 Hz - 110 MHz frequency range, as well as the a.c. conductivity and have very relevant properties, such as dielectric constant above 50, for the production of possible capacitive devices. All samples were investigated for possible applications in electronic circuits.

  2. MATRIX 2 RESULTS OF THE FY07 ENHANCED DOE HIGH-LEVEL WASTE MELTER THROUGHPUT STUDIES AT SRNL

    Energy Technology Data Exchange (ETDEWEB)

    Raszewski, F; Tommy Edwards, T; David Peeler, D

    2008-10-23

    % (based strictly on retention or solubility). (2) For those study glasses that had very close compositional overlap with the model development and/or model validation ranges of the current DWPF TL model (except TiO{sub 2} and MgO concentrations), there was very little difference in the predicted and measured TL values. Even though the TiO{sub 2} concentrations were above the 2 wt% upper limit, the results indicate that the current T{sub L} model is applicable in this compositional region with TiO{sub 2} contents up to approximately 3.5 wt%. (3) As the target glass compositions diverge from the model development and validation ranges, the T{sub L} data suggest that the model under-predicted the measured values. These discrepancies imply that there are individual oxides or oxide combinations that need to be accounted for in the model. These oxides include B{sub 2}O{sub 3}, SiO{sub 2}, MnO, TiO{sub 2} and/or their combinations. More data would be required to fill in these anticipated DWPF compositional regions for higher WL glasses so that the model coefficients could be refit to account for these differences. (4) Based on PCT response of HWL-21 and HWL-22 (two glasses that were prone to nepheline formation) it appears that increasing the B{sub 2}O{sub 3} concentration in glass does not consistently suppress the formation of nepheline in glasses with higher Al{sub 2}O{sub 3} and/or Na{sub 2}O content. Although the chemical durabilities of the quenched versions of these glasses were very acceptable, the canister centerline cooled (ccc) glasses exhibited a considerable decrease in durability and were found to contain nepheline via XRD. In fact, one of the glasses had a release that was 5 times greater than that of the Environmental Assessment (EA) benchmark glass. These results suggest a need for a more fundamental understanding of the compositional and kinetic effects of nepheline formation in high WL glasses. (5) Data have been generated in support of the replacement of the

  3. Weak matrix elements on the lattice - Circa 1995

    Energy Technology Data Exchange (ETDEWEB)

    Soni, A.

    1995-10-03

    Status of weak matrix elements is reviewed. In particular, e{prime}/e, B {yields} K*{gamma}, B{sub B} and B{sub B}, are discussed and the overall situation with respect to the lattice effort and some of its phenomenological implications are summarised. For e{prime}/e the need for the relevant matrix elements is stressed in view of the forthcoming improved experiments. For some of the operators, (e.g. O{sub 6}), even bound on their matrix elements would be very helpful. On B {yields} K{degrees}{gamma}, a constant behavior of T{sub 2} appears disfavored although dependence of T{sub 2} could, of course, be milder than a simple pole. Improved data is badly needed to settle this important issue firmly, especially in view of its ramification for extractions of V{sub td} from B {yields} {rho}{gamma}. On B{sub {kappa}}, the preliminary result from JLQCD appears to contradict Sharpe et al. JLQCD data seems to fit very well to linear {alpha} dependence and leads to an appreciably lower value of B{sub {kappa}}. Four studies of B{sub {kappa}} in the {open_quotes}full{close_quotes} (n{sub f} = 2) theory indicate very little quenching effects on B{sub {kappa}}; the full theory value seems to be just a little less than the quenched result. Based on expectations from HQET, analysis of B-parameter (B{sub h}{ell}) for the heavy-light mesons via B{sub h}{ell}) = constant + constants{prime}/m{sub h}{ell} is suggested. A summary of an illustrative sample of hadron matrix elements is given and constraints on CKM parameters (e.g. V{sub td}/V{sub ts}, on the unitarity triangle and on x{sub s}/x{sub d}, emerging from the lattice calculations along with experimental results are briefly discussed. In quite a few cases, for the first time, some indication of quenching errors on weak matrix elements are now becoming available.

  4. Anti-idiotypic nanobody-alkaline phosphatase fusion proteins: Development of a one-step competitive enzyme immunoassay for fumonisin B{sub 1} detection in cereal

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Mei [State Key Laboratory of Food Science and Technology, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); Jiangxi-OAI Joint Research Institute, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); Xu, Yang, E-mail: xuyang@ncu.edu.cn [State Key Laboratory of Food Science and Technology, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); Jiangxi-OAI Joint Research Institute, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); Liu, Xing [State Key Laboratory of Food Science and Technology, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); College of Food Science and Technology, Hainan University, No. 58 Renmin Avenue, Haikou 570228 (China); Li, Yanping; He, Qinghua [Jiangxi-OAI Joint Research Institute, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); Tu, Zhui [State Key Laboratory of Food Science and Technology, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); Fu, Jinheng [Jiangxi-OAI Joint Research Institute, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); Gee, Shirley J.; Hammock, Bruce D. [Department of Entomology and UCD Comprehensive Cancer Center, University of California, Davis, CA 95616 (United States)

    2016-06-14

    A rapid and sensitive one-step competitive enzyme immunoassay for the detection of FB{sub 1} was developed. The anti-idiotypic nanobody–alkaline phosphatase (Ab2β−Nb−AP) was validated by the AP enzyme activity and the properties of bounding to anti-FB1-mAb (3F11) through colorimetric and chemiluminescence analyses. The 50% inhibitory concentration and the detection limit (LOD) of colorimetric enzyme-linked immunosorbent assay (ELISA) for FB{sub 1} were 2.69 and 0.35 ng mL{sup −1}, respectively, with a linear range of 0.93–7.73 ng mL{sup −1}. The LOD of the chemiluminescence ELISA (CLIA) was 0.12 ng mL{sup −1}, and the IC{sub 50} was 0.89 ± 0.09 ng mL{sup −1} with a linear range of 0.29–2.68 ng mL{sup −1}. Compared with LC-MS/MS, the results of this assay indicated the reliability of the Ab2β−Nb−AP fusion protein based one-step competitive immunoassay for monitoring FB{sub 1} contamination in cereals. The Ab2β−Nb−AP fusion proteins have the potential to replace chemically-coupled probes in competitive enzyme immunoassay systems. - Highlights: • Ab2β−Nb−AP has the potential to replace chemically-coupled probes. • Ab2β−Nb−AP is homogeneous enzyme-labelled antigen can be prepared reproducibly. • We developed a green and rapid one-step competitive enzyme immunoassay. • The sensitivity of one-step CLIA was 9-folds higher than two-step ELISA.

  5. Afnor NF D 35-330. Gas-fired central heating boilers. Type B{sub 11} and B{sub 11BIS} boilers fitted with atmospheric burners of nominal heat input not exceeding 70 kW. (European standard EN 297); Afnor NF D 35-330. Chaudieres de chauffage central utilisant les combustibles gazeux. Chaudieres des types B{sub 11} et B{sub 11BIS} equipees de bruleurs atmospheriques dont le debit calorifique nominal est inferieur ou egal a 70 kW. (Norme europeenne EN 297)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-10-01

    This standard document defines the specifications and testing techniques relative to the manufacturing, safety, energy rational use, functioning capacity, classification and labeling of gas-fueled heating plants. It replaces the previous NF D 35-331 norm from November 1989 which comprised the NF D 35-331 norm from January 1980, its additives 1 (January 1980) and 2 (June 1984), its modifications 1 (July 1980), 2 (September 1986), 3 (December 1988) and 4 (November 1989) and the D 30-005 experimental norm of November 1991. (J.S.)

  6. Application of B{sub 4}C/Al{sub 2}O{sub 3} Burnable Absorber Rod to Control Excess Reactivity of SMR

    Energy Technology Data Exchange (ETDEWEB)

    Muth, Boravy; Hah, C. J. [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2016-10-15

    Soluble boron in a nuclear reactor coolant is one of the methods to control excess reactivity of the reactor. However, the use of soluble boron also causes some negative effects such as corrosion, more-positive tendency of Moderator Temperature Coefficient (MTC) and the requirement of Chemical Volume Control System (CVCS). One of the conceptual design features of SMR having been developed in Korea is soluble boron- free reactor to eliminate those drawbacks. Control rods and Burnable Absorber (BA) rods can be other methods than soluble to control excess reactivity. WABA (Wet Annular Burnable Absorber) and PYREX are such type. The other type is IFBA (Integral Fuel Burnable Absorber) in which fuel pellet surface is coated with BA. This paper compares nuclear characteristics of three types of BA as well as SLOBA in terms of k-infinite vs. burnup and explain design basis of SLOBA. This paper also presents the application of SLOBA rods to control long-term excess reactivity of SMR. The SMR loaded with SLOBA rods has been developed for the past few years in Korean. It is named as Bandi-50 with design features of 180 MWth, 37 FAs, fuel assembly height of 200 cm. Soluble-boron-free is one of nuclear design requirements of Bandi-50 and is achieved by controlling excess reactivity of the SMR using BAs and control rods only. To achieve this design requirement, LP is carefully determined in such way that CBC should be as low as possible. Fuel assembly cross-sections are generated by CASMO-3, and core depletion calculations are performed by MASTER.

  7. Evaluating the electronic energy eigenvalues for A{sub 2}B{sub 6} crystals obtained with the GGGA+U functional

    Energy Technology Data Exchange (ETDEWEB)

    Syrotyuk, Stepan V. [Semiconductor Electronics Department, Lviv Polytechnic National University, S. Bandera Street 12, 79000 Lviv (Ukraine)

    2010-06-15

    Electronic energy bands of ZnS, ZnSe, and ZnTe crystals evaluated within the mixed basis approach with using the core Bloch states and plane waves. The exchange-correlation potential has been derived from the new exchange-correlation-energy functional including the density gradient corrections and the intra-atomic Coulomb term U. The calculated energy band structure parameters of the crystals show an improvement compared with the LDA results. The semicore Zn 3d state energies are closer to experimental data than those obtained within the LDA approach. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Design Validation of a {sup 10}B{sub 4}C Coated RSP with Multi-layered structure for Homeland Security

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Su Hyun; Kim, Jong Yul; Lee, Joo Hyun; Moon, Mung Kook [KAERI, Daejeon (Korea, Republic of); Lim, Chang Hwy [Korea Research Institute of Ships and Ocean Engineering, Daejeon (Korea, Republic of); Lim, Ki Seo [Myongji University, Yongin (Korea, Republic of)

    2016-05-15

    It is a national priority to prevent radiological threats including radiological terrorism and smuggling nuclear material and devices. For this purpose, many governments and relevant organizations have been exploiting radiation detection technology. Especially, radiation portal monitor (RPM) is a widely used type of radiation detectors when it comes to homeland security and commonly deployed at strategic sites like airports and ports. In the most cases, they could be divided into two types of primary screening and secondary screening. In the latter case, hand-held detectors are mainly used for a closer inspection. On the other hand, RPMs for the primary screening, our concern, are stationary mounted type and comprise gamma-ray detector and neutron detector in many cases. The expected performance of the design of a RSP(Radiation Sensor Panel) has been demonstrated. According to the results of the simulation, three RSPs should be needed to meet the criterion mentioned in subsection 2.1. The design still can be validated when taking into account that the geometrical acceptance will be increased since it has been planned that the RPM is going to installed with four RSPs.

  9. The CMSSM and NUHM1 in light of 7 TeV LHC, B{sub s} {yields} {mu}{sup +}{mu}{sup -} and XENON100 data

    Energy Technology Data Exchange (ETDEWEB)

    Buchmueller, O.; Citron, M. [Imperial College, London (United Kingdom). Blackett Laboratory; Cavanaugh, R. [Fermi National Accelerator Laboratory, Batavia, IL (United States); Illinois Univ., Chicago, IL (US). Physics Dept.] (and others)

    2012-08-15

    We make a frequentist analysis of the parameter space of the CMSSM and NUHM1, using a Markov Chain Monte Carlo (MCMC) with 95 (221) million points to sample the CMSSM (NUHM1) parameter spaces. Our analysis includes the ATLAS search for supersymmetric jets+missing E{sub T} signals using {proportional_to}5/fb of LHC data at 7 TeV, which we apply using PYTHIA and a Delphes implementation that we validate in the relevant parameter regions of the CMSSM and NUHM1. Our analysis also includes the constraint imposed by searches for BR(B{sub s} {yields} {mu}{sup +}{mu}{sup -}) by LHCb, CMS, ATLAS and CDF, and the limit on spin-independent dark matter scattering from 225 live days of XENON100 data. We assume M{sub h}{proportional_to}125 GeV, and use a full set of electroweak precision and other flavour-physics observables, as well as the cold dark matter density constraint. The ATLAS{sub 5/fb} constraint has relatively limited effects on the 68 and 95% CL regions in the (m{sub 0},m{sub 1/2}) planes of the CMSSM and NUHM1. The new BR(B{sub s} {yields} {mu}{sup +}{mu}{sup -}) constraint has greater impacts on these CL regions, and also impacts significantly the 68 and 95% CL regions in the (M{sub A},tan {beta}) planes of both models, reducing the best-fit values of tan {beta}. The recent XENON100 data eliminate the focus-point region in the CMSSM and affect the 68 and 95% CL regions in the NUHM1. In combination, these new constraints reduce the best-fit values of m{sub 0},m{sub 1/2} in the CMSSM, and increase the global {chi}{sup 2} from 31.0 to 32.8, reducing the p-value from 12% to 8.5%. In the case of the NUHM1, they have little effect on the best-fit values of m{sub 0}, m{sub 1/2}, but increase the global {chi}{sup 2} from 28.9 to 31.3, thereby reducing the p-value from 15% to 9.1%.

  10. (Experimental studies of elementary particle interactions at high energies)

    Energy Technology Data Exchange (ETDEWEB)

    Khuri, N.N.

    1990-01-01

    This report includes descriptions of the combined work of both Tasks B and B{sub 1} at Rockefeller University. Some highlights are worth stressing in this brief introduction. First, one should note the active involvement of two members of our group, Ren and Callaway, in understanding the problem of superconductivity, both high and low {Tc}. This reflects the broad reach of many, but perhaps not all, particle physicists. Second, spurred by the Rockefeller environment, some in our group are also looking at problems in biology. As for our main purpose, I would like to single out the results of Sanda and Morozumi on the {Delta}I = {1/2} rule, the work of Bitar, Ren and myself on a new approach to the path integral, S.Y. Pi's results on Chern-Simons non-relativistic quantum mechanics, and finally the work by Lee and collaborators on the origin of Fermion masses and mixing.

  11. Structural study and DC conductivity of vanadyl doped zinc lithium borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Seema [Physics Department, Deenbandhu Chhotu Ram University of Science & Technology, Murthal-131039 (India); Physics Department, Baba Mast Nath University, Asthal Bohr, Rohtak-124001 (India); Khasa, S., E-mail: skhasa@rediff.com; Dahiya, M. S.; Yadav, Arti [Physics Department, Deenbandhu Chhotu Ram University of Science & Technology, Murthal-131039 (India); Agarwal, A. [Applied Physics Department, Guru Jambheshwar University of Science & Technology, Hisar-125001 (India); Dahiya, S. [Physics Department, Baba Mast Nath University, Asthal Bohr, Rohtak-124001 (India)

    2015-06-24

    Glasses with composition xZnO⋅(30 − x)⋅Li{sub 2}O⋅70B{sub 2}O{sub 3} containing 2 mol% of V{sub 2}O{sub 5} (x = 0, 2, 5, 7 and 10) were prepared by standard melt-quench technique. The amorphous nature of the glass samples was confirmed by using x-ray diffraction. The structural changes in these glasses have been investigated by employing IR spectroscopy in the mid-IR range. The infrared spectroscopic analysis confirms the presence of both triangular and tetraheldral coordinated boron units and absence of boroxol ring. It also shows that metal-oxide vibrations are present which are due to the bonding of lithium and zinc ions with oxygen. The dc conductivity was measured in the temperature range 353-523 K. The dc conductivity results show that conductivity decreases and activation energy increases when Li{sub 2}O is replaced by ZnO, keeping the concentration of B{sub 2}O{sub 3} constant. Decrease in conductivity and increase in activation energy shows that addition of ZnO to the glass matrix shows a “blocking effect” on the overall mobility of alkali ions, but at higher concentration the hopping effect was also observed.

  12. Studies on femtosecond fluorescence dynamics of photosystem II Particle complex at low temperature

    CERN Document Server

    Liu Xiao; He, Jun Fang; Cai, Xia; Peng Jun Fang; Kuang Ting Yun

    2004-01-01

    In order to understanding the diversity of energy transfer in PS II at different temperatures, PS II particle complex purified from spinach was investigated with femtosecond time-resolved fluorescence spectroscopy in the case of excitation 507 nm at 83 K, 160 K, 273 K. The data were analyzed by Gauss analysis and fluorescence decay time- fitting. Some results were achieved. (1) Increase of the temperature results in a broadening of the fluorescence emission spectra due to the temperature-dependent expressions for nonradiative transitions between two electronic states. (2) There are at least several characteristic Chl molecules exist in PS II particle complex, i.e. Chl b/sub 639//sup 640/, Chl b/sub 640//sup 645/, Chl a/sub 660//sup 663/, Chl a/sub 667//sup 668/, Chl a/sub 673//sup 676/, Chl a/sub 680 //sup 681/, Chl a/sub 680/681//sup 682/, Chl a/sub 684,685//sup 668 /689/, Chl a/sub 688//sup 698/, (Chl a/b/sub a//sup e/: a represents the peak of absorption, e represents the peak of emission). (3) Though the ...

  13. Study on magnetic properties of (Nd{sub 0.8}Ce{sub 0.2}){sub 2−x}Fe{sub 12}Co{sub 2}B (x = 0–0.6) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Tan, G.S.; Xu, H., E-mail: huixu8888@shu.edu.cn; Yu, L.Y.; Tan, X.H.; Zhang, Q.; Gu, Y.; Hou, X.L.

    2017-09-01

    Highlights: • (Nd{sub 0.8}Ce{sub 0.2}){sub 2−x}Fe{sub 12}Co{sub 2}B alloys are prepared by melt-spinning method with simultaneously decreasing of Nd, Ce concentration. • The magnetic properties B{sub r}, (BH){sub max} and squareness are all improved with an appropriate reduction of Nd, Ce concentration. • Magnetic field heat treatment offers a significant improvement in B{sub r}, (BH){sub max} and squareness. - Abstract: In the present work, (Nd{sub 0.8}Ce{sub 0.2}){sub 2−x}Fe{sub 12}Co{sub 2}B (x = 0–0.6) permanent alloys are prepared by melt-spinning method. The hard magnetic properties of (Nd{sub 0.8}Ce{sub 0.2}){sub 2−x}Fe{sub 12}Co{sub 2}B (x = 0–0.6) alloys annealed at optimum temperatures have been investigated systematically. Depending on the Nd, Ce concentration, the maximum energy product ((BH){sub max}) and remanence (B{sub r}) increase gradually with x in the range of 0 ≤ x ≤ 0.4, whereas decrease gradually in the alloys with 0.4 < x ≤ 0.6. It is found that the optimum magnetic properties are obtained at x = 0.4: H{sub ci} = 4.9 kOe, B{sub r} = 10.1 kG, (BH){sub max} = 13.7 MGOe. Specifically, magnetic field heat treatment below the Curie temperature is applied for (Nd{sub 0.8}Ce{sub 0.2}){sub 1.6}Fe{sub 12}Co{sub 2}B (x = 0.4) annealed ribbons. The magnetic properties B{sub r}, (BH){sub max} and squareness are all enhanced after the magnetic field heat treatment. The (BH){sub max} shows a substantial increase from 13.7 MGOe to 16.0 MGOe after the heat treatment at 623 K with a magnetic field of 1 T, which gets 17% improvement compared with that of the sample without a magnetic field heat treatment. We demonstrate that the magnetic field heat treatment plays a certain role in the magnetization reversal behavior and can improve the microstructure of (Nd{sub 0.8}Ce{sub 0.2}){sub 1.6}Fe{sub 12}Co{sub 2}B alloy.

  14. Measurement of charm and beauty-production in deep inelastic scattering at HERA and test beam studies of ATLAS pixel sensors

    Energy Technology Data Exchange (ETDEWEB)

    Libov, Vladyslav

    2013-08-15

    A measurement of charm and beauty production in Deep Inelastic Scattering at HERA is presented. The analysis is based on the data sample collected by the ZEUS detector in the period from 2003 to 2007 corresponding to an integrated luminosity of 354 pb{sup -1}. The kinematic region of the measurement is given by 54.2(5) GeV for charm (beauty) and -1.6<{eta}{sup jet}<2.2 for both charm and beauty, where E{sup jet}{sub T} and {eta}{sup jet} are the transverse energy and pseudorapidity of the jet, respectively. The significance of the decay length and the invariant mass of charged tracks associated with the secondary vertex are used as discriminating variables to distinguish between signal and background. Differential cross sections of jet production in charm and beauty events as a function of Q{sup 2}, y, E{sup jet}{sub T} and {eta}{sup jet} are measured. Results are compared to Next-to-Leading Order (NLO) predictions from Quantum Chromodynamics (QCD) in the fixed flavour number scheme. Good agreement between data and theory is observed. Contributions of the charm and beauty production to the inclusive proton structure function, F{sup cbar} {sup c}{sub 2} and F{sup b} {sup anti} {sup b}{sub 2}, are determined by extrapolating the double differential cross sections using NLO QCD predictions. Contributions to the test beam program for the Insertable B-Layer upgrade project of the ATLAS pixel detector are discussed. The test beam data analysis software package EUTelescope was extended, which allowed an efficient analysis of ATLAS pixel sensors. The USBPix DAQ system was integrated into the EUDET telescope allowing test beam

  15. Moessbauer spectroscopy of Fe-B based amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kreislerova, Y.; Zemcik, T. (Ceskoslovenska Akademie Ved, Brno. Ustav Fyzikalni Metalurgie)

    1984-01-01

    The influence of heat treatment on structure changes of amorphous alloy Fe/sub 83/B/sub 17/ was studied by /sup 57/Fe Moessbauer spectroscopy. At 613 K a change in the magnetization direction was detected and at 633 K the precipitation of ..cap alpha..-Fe quantitatively determined.

  16. Effect of gamma irradiation on the B vitamins of pork chops and chicken breasts

    Energy Technology Data Exchange (ETDEWEB)

    Fox, J.B. Jr.; Thayer, D.W.; Jenkins, R.K.; Phillips, J.G.; Ackerman, S.A.; Beecher, G.R.; Holden, J.M.; Morrow, F.D.; Quirbach, D.M.

    1989-04-01

    A study was made of the effect of low-dose gamma irradiation on the content of thiamine (B/sub 1/), riboflavin (B/sub 2/), niacin, pyridoxine (B/sub 6/) and cobalamin (B/sub 12/) in pork chops, and thiamine, riboflavin and niacin in chicken breasts. Over the range of dose and temperature studied (0.49-6.65 kGy from -20 to 20/sup 0/C) it was possible to derive a mathematical expression for predicting losses. A calculation was made of the effect of the loss of thiamine, riboflavin and niacin due to irradiation on overall loss of these vitamins in the American diet. Losses of riboflavin and niacin were of the order of a fraction of a per cent. The calculated loss at 1.0kGy of thiamine in cooked pork was only 1.5%. There were initial increases with radiation doses up to 2-4 kGy in measured concentrations of riboflavin and niacin in pork and chicken. Increases were highly significant, and of concern to the study of radiation effects and the chemical method of determination of these vitamins.

  17. A comparative study of the Au + H{sub 2}, Au{sup +} + H{sub 2}, and Au{sup −} + H{sub 2} systems: Potential energy surfaces and dynamics of reactive collisions

    Energy Technology Data Exchange (ETDEWEB)

    Dorta-Urra, Anaís [Facultad de Ciencias Básicas y Aplicadas, Departamento de Física, Universidad Militar Nueva Granada, Bogotá DC (Colombia); Zanchet, Alexandre; Roncero, Octavio [Instituto de Física Fundamental, CSIC Serrano 123, 28006 Madrid (Spain); Aguado, Alfredo [Facultad de Ciencias, Departamento de Química-Física Aplicada, Unidad Asociada CSIC-UAM, Universidad Autónoma de Madrid, 28049 Madrid (Spain)

    2015-04-21

    In order to study the Au{sup −} + H{sub 2} collision, a new global potential energy surface (PES) describing the ground electronic state of AuH{sub 2}{sup −} system is developed and compared with the PESs of the neutral [Zanchet et al., J. Chem. Phys. 132, 034301 (2010)] and cationic systems [Anaís et al., J. Chem. Phys. 135, 091102 (2011)]. We found that Au{sup −} − H{sub 2} presents a H-Au-H insertion minimum attributed to the stabilization of the LUMO 3b{sub 2} orbital, which can be considered as the preamble of the chemisorption well appearing in larger gold clusters. While the LUMO orbital is stabilized, the HOMO 6a{sub 1} is destabilized, creating a barrier at the geometry where the energy orbitals’ curves are crossing. In the anion, this HOMO is doubly occupied, while in the neutral system is half-filled and completely empty in the cation, explaining the gradual disappearance of the well and the barrier as the number of electrons decreases. The cation presents a well in the entrance channel partially explained by electrostatic interactions. The three systems’ reactions are highly endothermic, by 1.66, 2.79, and 3.23 eV for AuH, AuH{sup +}, and AuH{sup −} products, respectively. The reaction dynamics is studied using quasi-classical trajectory method for the three systems. The one corresponding to the anionic system is new in this work. Collision energies between 1.00 and 8.00 eV, measured for the cation, are in good agreement with the simulated cross section for the AuH{sup +}. It was also found that the total fragmentation, in three atoms, competes becoming dominant at sufficiently high energy. Here, we study the competition between the two different reaction pathways for the anionic, cationic, and neutral species, explaining the differences using a simple model based on the topology of the potential energy surfaces.

  18. LHCb performance on $B_{s}^{0} \\to h^{+}h^{-}$ measurements

    CERN Document Server

    Carbone, A

    2004-01-01

    The selection of B/sup 0/ to pi /sup +/ pi /sup -/, B/sup 0/ to K/sup +/ pi /sup -/, B/sub s//sup 0/ to K/sup +/K/sup -/ and B/sub s//sup 0 / to pi /sup +/K/sup -/ decays at LHCb is presented, and the estimated annual signal yields and background-to-signal ratios for specific and combinatorial backgrounds are quoted. The combined measurement of the B/sup 0/ to pi /sup +/ pi /sup -/ and B/sub s//sup 0/ to K/sup +/K/sup -/ CP asymmetries provides a promising strategy to determine the gamma angle of the unitarity triangle. The results of a study on the sensitivity on the direct and mixing-induced CP- violating observables for B/sup 0/ to pi /sup +/ pi /sup -/ and B/sub s//sup 0/ to K/sup +/K/sup -/decays, as well as on gamma are also discussed. (14 refs).

  19. Effect of Ga doping on micro/structural, electrical and optical properties of pulsed laser deposited ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, S.D. [Centre for Advanced Studies in Materials Science and Condensed Matter Physics, Department of Physics, University of Pune, Pune 411 007 (India); Deshmukh, A.V. [Centre for Advanced Studies in Materials Science and Condensed Matter Physics, Department of Physics, University of Pune, Pune 411 007 (India); Department of Physics, College of Engineering, Pune 411 005 (India); Date, S.K. [Centre for Advanced Studies in Materials Science and Condensed Matter Physics, Department of Physics, University of Pune, Pune 411 007 (India); Sathe, V.G. [UGC-DAE Consortium for Scientific Research, University Campus, Indore-452 017 (India); Adhi, K.P., E-mail: kpa@physics.unipune.ac.in [Centre for Advanced Studies in Materials Science and Condensed Matter Physics, Department of Physics, University of Pune, Pune 411 007 (India)

    2011-12-01

    Undoped and Ga doped ZnO thin films (1% GZO, 3% GZO and 5% GZO) were grown on c-Al{sub 2}O{sub 3} substrates using the 1, 3 and 5 at. wt.% Ga doped ZnO targets by pulsed laser deposition. X-ray diffraction studies revealed that highly c-axis oriented, single phase, undoped and Ga doped ZnO thin films with wurtzite structure were deposited. Micro-Raman scattering analysis showed that Ga doping introduces defects in the host lattice. The E{sub 2}{sup High} mode of ZnO in Ga doped ZnO thin film was observed to shift to higher wavenumber indicating the presence of residual compressive stress. Appearance of the normally Raman inactive B{sub 1} modes (B{sub 1}{sup Low}, 2B{sub 1}{sup Low} and B{sub 1}{sup High}) due to breaking of local translational symmetry, also indicated that defects were introduced into the host lattice due to Ga incorporation. Band gap of the Ga doped ZnO thin films was observed to shift to higher energy with the increase in doping concentration and is explicated by the Burstein-Moss effect. Electrical resistivity measurements of the undoped and GZO thin films in the temperature range 50 to 300 K revealed the metal to semiconductor transition for 3 and 5% GZO thin films.

  20. Measurements of Rates, Asymmetries, and Angular Distributions in B -> K l+ l- and B -> K* l+ l- Decays

    Energy Technology Data Exchange (ETDEWEB)

    Hollar, Jonathan; /SLAC /Wisconsin U., Madison

    2006-09-21

    This dissertation describes studies of the rare decays B{sub d} {yields} K{ell}{sup +}{ell}{sup -} and B{sub d} {yields} K*{ell}{sup +}{ell}{sup -}, where {ell}{sup +}{ell}{sup -} is either an e{sup +}e{sup -} or a {mu}{sup +}{mu}{sup -} pair. These decays are highly suppressed in the Standard Model, and could be strongly affected by physics beyond the Standard Model. The authors measure the total branching fractions {Beta}(B{sub d} {yields} K{ell}{sup +}{ell}{sup -}) = (0.34 {+-} 0.07 {+-} 0.03) x 10{sup -6}, {Beta}(B{sub d} {yields} K*{ell}{sup +}{ell}{sup -}) = (0.78{sub -0.17}{sup +0.19} {+-} 0.12) x 10{sup -6}. In addition, they measure the partial branching fractions, relative abundance of muons to electrons, direct CP asymmetry, dilepton forward-backward asymmetry, and longitudinal polarization of the K* in these modes. They also search for the lepton flavor-violating decays B{sub d} {yields} Ke{sup {+-}}{mu}{sup {-+}} and B{sub d} {yields} K*e{sup {+-}}{mu}{sup {-+}}. The measurements were performed at the SLAC PEP II storage ring running at the {Upsilon}(4S) resonance.

  1. Contribution of diffusion-weighted MR imaging for predicting benignity of complex adnexal masses

    Energy Technology Data Exchange (ETDEWEB)

    Thomassin-Naggara, Isabelle [Hopital Tenon, Assistance Publique Hopitaux de Pariss, Department of Radiology, Paris (France); Universite Rene Descartes, LRI-EA4062, Paris (France); Darai, Emile [Hopital Tenon, Assistance Publique Hopitaux de Pariss, Department of Gynecology-Obstetrics, Paris (France); Cuenod, Charles A.; Fournier, Laure [Universite Rene Descartes, LRI-EA4062, Paris (France); Hopital Europeen Georges Pompidou (HEGP), Assistance Publique Hopitaux de Paris, Department of Radiology, Paris (France); Toussaint, Irwin; Marsault, Claude; Bazot, Marc [Hopital Tenon, Assistance Publique Hopitaux de Pariss, Department of Radiology, Paris (France)

    2009-06-15

    The purpose of this study was to prospectively assess the contribution of diffusion-weighted MR imaging (DWI) for characterizing complex adnexal masses. Seventy-seven women (22-87 years old) with complex adnexal masses (30 benign and 47 malignant) underwent MR imaging including DWI before surgery. Conventional morphological MR imaging criteria were recorded in addition to b{sub 1,000} signal intensity and apparent diffusion coefficient (ADC) measurements of cystic and solid components. Positive likelihood ratios (PLR) were calculated for predicting benignity and malignancy. The most significant criteria for predicting benignity were low b{sub 1,000} signal intensity within the solid component (PLR = 10.9), low T2 signal intensity within the solid component (PLR = 5.7), absence of solid portion (PLR = 3.1), absence of ascites or peritoneal implants (PLR = 2.3) and absence of papillary projections (PLR = 2.3). ADC measurements did not contribute to differentiating benign from malignant adnexal masses. All masses that displayed simultaneously low signal intensity within the solid component on T2-weighted and on b{sub 1,000} diffusion-weighted images were benign. Alternatively, the presence of a solid component with intermediate T2 signal and high b{sub 1,000} signal intensity was associated with a PLR of 4.5 for a malignant adnexal tumour. DWI signal intensity is an accurate tool for predicting benignity of complex adnexal masses. (orig.)

  2. Effect of annealing on magnetic properties and structure of Fe-Ni based magnetic microwires

    Energy Technology Data Exchange (ETDEWEB)

    Zhukova, V. [Dpto. de Física de Materiales, Fac. Químicas, UPV/EHU, 20018 San Sebastian (Spain); Dpto. de Física Aplicada, EUPDS, UPV/EHU, 20018 San Sebastian (Spain); Korchuganova, O.A.; Aleev, A.A. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409 Moscow (Russian Federation); Tcherdyntsev, V.V.; Churyukanova, M. [National University of Science and Technology «MISIS», 119049 Moscow (Russian Federation); Medvedeva, E.V. [Institute of Electrophysics, Ural Branch, Russian Academy of Sciences 620016 Yekaterinburg (Russian Federation); Seils, S.; Wagner, J. [Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology, 76131 Karlsruhe (Germany); Ipatov, M. [Dpto. de Física de Materiales, Fac. Químicas, UPV/EHU, 20018 San Sebastian (Spain); Dpto. de Física Aplicada, EUPDS, UPV/EHU, 20018 San Sebastian (Spain); Blanco, J.M. [Dpto. de Física Aplicada, EUPDS, UPV/EHU, 20018 San Sebastian (Spain); Kaloshkin, S.D. [National University of Science and Technology «MISIS», 119049 Moscow (Russian Federation); Aronin, A. [National University of Science and Technology «MISIS», 119049 Moscow (Russian Federation); Insitute of Solid State Physics, Moscow Region, 142432 Chernogolovka (Russian Federation); Abrosimova, G.; Orlova, N. [Insitute of Solid State Physics, Moscow Region, 142432 Chernogolovka (Russian Federation); and others

    2017-07-01

    Highlights: • High domain wall mobility of Fe-Ni-based microwires. • Enhancement of domain wall velocity and mobility in Fe-rich microwires after annealing. • Observation of areas enriched by Si and depleted by B after annealing. • Phase separation in annealed Fe-Ni based microwires in metallic nucleus and near the interface layer. - Abstract: We studied the magnetic properties and domain wall (DW) dynamics of Fe{sub 47.4}Ni{sub 26.6}Si{sub 11}B{sub 13}C{sub 2} and Fe{sub 77.5}Si{sub 7.5}B{sub 15} microwires. Both samples present rectangular hysteresis loop and fast magnetization switching. Considerable enhancement of DW velocity is observed in Fe{sub 77.5}Si{sub 7.5}B{sub 15}, while DW velocity of samples Fe{sub 47.4}Ni{sub 26.6}Si{sub 11}B{sub 13}C{sub 2} is less affected by annealing. The other difference is the magnetic field range of the linear region on dependence of domain wall velocity upon magnetic field: in Fe{sub 47.4}Ni{sub 26.6}Si{sub 11}B{sub 13}C{sub 2} sample is considerably shorter and drastically decreases after annealing. We discussed the influence of annealing on DW dynamics considering different magnetoelastic anisotropy of studied microwires and defects within the amorphous state in Fe{sub 47.4}Ni{sub 26.6}Si{sub 11}B{sub 13}C{sub 2}. Consequently we studied the structure of Fe{sub 47.4}Ni{sub 26.6}Si{sub 11}B{sub 13}C{sub 2} sample using X-ray diffraction and the atom probe tomography. The results obtained using the atom probe tomography supports the formation of the B-depleted and Si-enriched precipitates in the metallic nucleus of Fe-Ni based microwires.

  3. Nickel electrodes as a cheap and versatile platform for studying structure and function of immobilized redox proteins

    Energy Technology Data Exchange (ETDEWEB)

    Han, Xiao Xia [State Key Laboratory of Supramolecular Structure and Materials, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Institut für Chemie, Technische Universität Berlin, Sekr. PC14, Strasse des 17. Juni 135, D-10623 Berlin (Germany); Li, Junbo [State Key Laboratory of Supramolecular Structure and Materials, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Öner, Ibrahim Halil [Institut für Chemie, Technische Universität Berlin, Sekr. PC14, Strasse des 17. Juni 135, D-10623 Berlin (Germany); Zhao, Bing [State Key Laboratory of Supramolecular Structure and Materials, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Leimkühler, Silke [Institut für Biochemie und Biologie, Universität Potsdam, Karl-Liebknecht Straße 24-25, H. 25, Golm D-14476 (Germany); Hildebrandt, Peter [Institut für Chemie, Technische Universität Berlin, Sekr. PC14, Strasse des 17. Juni 135, D-10623 Berlin (Germany); Weidinger, Inez M., E-mail: i.weidinger@mailbox.tu-berlin.de [Institut für Chemie, Technische Universität Berlin, Sekr. PC14, Strasse des 17. Juni 135, D-10623 Berlin (Germany)

    2016-10-19

    Practical use of many bioelectronic and bioanalytical devices is limited by the need of expensive materials and time consuming fabrication. Here we demonstrate the use of nickel electrodes as a simple and cheap solid support material for bioelectronic applications. The naturally nanostructured electrodes showed a surprisingly high electromagnetic surface enhancement upon light illumination such that immobilization and electron transfer reactions of the model redox proteins cytochrome b{sub 5} (Cyt b{sub 5}) and cytochrome c (Cyt c) could be followed via surface enhanced resonance Raman spectroscopy. It could be shown that the nickel surface, when used as received, promotes a very efficient binding of the proteins upon preservation of their native structure. The immobilized redox proteins could efficiently exchange electrons with the electrode and could even act as an electron relay between the electrode and solubilized myoglobin. Our results open up new possibility for nickel electrodes as an exceptional good support for bioelectronic devices and biosensors on the one hand and for surface enhanced spectroscopic investigations on the other hand. - Highlights: • Nickel electrodes were used without further functionalization as supports for various redox proteins. • It was possible to monitor the immobilized proteins via surface enhanced Raman spectroscopy. • The native structure of the immobilized proteins was preserved and they could exchange electrons with the Ni electrode. • The immobilized redox proteins worked as an electron relay between electrode and solubilized myoglobin.

  4. Transition metal borides. Synthesis, characterization and superconducting properties

    Energy Technology Data Exchange (ETDEWEB)

    Kayhan, Mehmet

    2013-07-12

    A systematic study was done on the synthesis and superconducting properties of metal rich transition metal borides. Five different binary systems were investigated including the boride systems of niobium, tantalum, molybdenum, tungsten and rhenium. High temperature solid state methods were used in order to synthesize samples of different transition metal borides of the composition M{sub 2}B, MB, M{sub 3}B{sub 2}, MB{sub 2}, and M{sub 2}B{sub 4}. The reactions were carried out in three different furnaces with different sample containers: the electric arc (copper crucible), the high frequency induction furnace (boron nitride, tantalum or glassy carbon crucibles), and the conventional tube furnace (sealed evacuated quartz ampoules). The products obtained were characterized with X-ray powder diffractometry, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Phase analyses and crystal structure refinements using the Rietveld method and based on structure models known from literature were performed. A neutron diffraction measurement was done for W{sub 2}B{sub 4} to allow for a complete crystal structure determination, because of the presence of a heavy element like tungsten and a light element like boron that made it difficult to determine the accurate determination of the boron atom positions and occupancies from X-ray data. A new structure model for W{sub 2}B{sub 4} was proposed. Magnetic measurements in a SQUID magnetometer down to temperatures as low as 1.8 K were performed to several of the products in order to see if the transition metal borides become superconducting at low temperatures, and the results were compared with data from literature. Superconducting properties were found for the following compounds: NbB{sub 2} (T{sub C} = 3.5 K), β-MoB (T{sub C} = 2.4 K), β-WB (T{sub C} = 2.0 K), α-WB (T{sub C} = 4.3 K), W{sub 2}B{sub 4} (T{sub C} = 5.4 K), Re{sub 7}B{sub 3} (T{sub C} = 2.4 K). A relationship between the superconducting properties

  5. The effect of deformation treatment on the decomposition of supersaturated Ni(Nb,B) and Ni(Mo,B) solid solutions synthesized by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Kubalova, L.M., E-mail: kubal@yandex.ru [K.L. Khetagurov North-Ossetian State University, Vatutina Str. 44-46, Vladikavkaz 362025 (Russian Federation); Fadeeva, V.I., E-mail: fadeeva@general.chem.msu.ru [Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation)

    2014-02-15

    Highlights: • Influence of deformation on decomposition of Ni-based solid solutions was studied. • X-ray diffraction analysis and scanning electron microscopy were used. • Decomposition of Ni(Nb,B), Ni(Mo,B) solid solutions takes place under deformation. • Formation of Ni{sub 21}(Nb,Mo){sub 2}B{sub 6}τ-phases after deformation treatment is observed. • Identity of MA and deformation on the decomposition of solid solutions is shown. -- Abstract: The effect of rotary-shear deformation during powders compacting on the decomposition of supersaturated Ni(Nb,B) and Ni(Mo,B) solid solutions is studied. The metastable fcc solid solutions were synthesized by mechanical alloying (MA) of the mixtures of components of Ni{sub 75}Nb{sub 12}B{sub 13} and Ni{sub 73}Mo{sub 14}B{sub 13} compositions. The powders were compacted on a Bridgman anvil. Col plastic deformation action is realized by using this technique. As a result the initial structure of nonequilibrium supersaturated solid solutions changed. The data of X-ray diffraction analysis and scanning electron microscopy showed a partial decomposition of Ni(Nb,B) and Ni(Mo,B) solid solutions, which leads to the formation of cubic boride τ phases – Ni{sub 21}Nb{sub 2}B{sub 6} with a lattice parameter of a = 1.0572 nm and, correspondingly, Ni{sub 21}Mo{sub 2}B{sub 6} phase with a lattice parameter of a = 1.0498 nm. The τ phase probably forms coherently to the fcc crystal lattice of solid solution because of its lattice parameter is equal to three lattice parameter of nickel. According to the data of local X-ray spectral analysis, the compacted alloys are heterogeneous and are contained boron-reach and also niobium- and molybdenum-rich regions.

  6. Qualitative studies

    National Research Council Canada - National Science Library

    Qualitative Studies (QS) aims to become a central forum for discussions of qualitative research in psychology, education, communication, cultural studies, health sciences and social sciences in general...

  7. Study Drugs

    Science.gov (United States)

    ... What Are Study Drugs? Doctors prescribe medicines like Adderall and Ritalin to treat conditions like attention deficit ... stimulants are used as study drugs: amphetamines like Adderall, Dexedrine, or Vyvanse methylphenidates like Ritalin or Concerta ...

  8. Cystometric study

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003904.htm Cystometric study To use the sharing features on this page, please enable JavaScript. Cystometric study measures the amount of fluid in the bladder ...

  9. Initial Study

    DEFF Research Database (Denmark)

    Torp, Kristian

    2009-01-01

    increased. In the initial study presented here, the time it takes to pass an intersection is studied in details. Two major signal-controlled four-way intersections in the center of the city Aalborg are studied in details to estimate the congestion levels in these intersections, based on the time it takes...

  10. HTS Teologiese Studies / Theological Studies

    African Journals Online (AJOL)

    HTS Teologiese Studies/Theological Studies is an acclaimed Open Access journal with broad coverage that promotes multidisciplinary, religious, and biblical aspects of studies in the international theological arena. The journal's publication criteria are based on high ethical standards and the rigor of the methodology and ...

  11. Europaian Studies

    OpenAIRE

    Manners, Ian

    2003-01-01

    This article is written for the special issue on European Studies and reflects on 45 years of theorising contemporary Europe, within the context of broader developments in the social sciences. What is immediately clear to anyone reading this article, the Journal of Contemporary European Studies, Journal of  Common Market Studies, Journal of European Public Policy, Journal of European Integration, or any of the many other established journals of contemporary or any of the many other establishe...

  12. Synchrotron X-ray diffraction studies of phase transitions and mechanical properties of nanocrystalline materials at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Prilliman, Stephen Gerald [Univ. of California, Berkeley, CA (United States)

    2003-01-01

    The behavior of nanocrystals under extreme pressure was investigated using synchrotron x-ray diffraction. A major part of this investigation was the testing of a prototype synchrotron endstation on a bend magnet beamline at the Advanced Light Source for high pressure work using a diamond anvil cell. The experiments conducted and documented here helped to determine issues of efficiency and accuracy that had to be resolved before the construction of a dedicated ''super-bend'' beamline and endstation. The major conclusions were the need for a cryo-cooled monochromator and a fully remote-controllable pressurization system which would decrease the time to change pressure and greatly reduce the error created by the re-placement of the diamond anvil cell after each pressure change. Two very different types of nanocrystal systems were studied, colloidal iron oxide (Fe2O3) and thin film TiN/BN. Iron oxide nanocrystals were found to have a transition from the γ to the α structure at a pressure strongly dependent on the size of the nanocrystals, ranging from 26 GPa for 7.2 nm nanocrystals to 37 GPa for 3.6 nm nanocrystals. All nanocrystals were found to remain in the α structure even after release of pressure. The transition pressure was also found, for a constant size (5.7 nm) to be strongly dependent on the degree of aggregation of the nanocrystals, increasing from 30 GPa for completely dissolved nanocrystals to 45 GPa for strongly aggregated nanocrystals. Furthermore, the x-ray diffraction pattern of the pressure induced α phase demonstrated a decrease in intensity for certain select peaks. Together, these observations were used to make a complete picture of the phase transition in nanocrystalline systems. The size dependence of the transition was interpreted as resulting from the extremely high surface energy of the α phase which would increase the thermodynamic offset and thereby increase the kinetic barrier to transition

  13. Studying effect of MoO{sub 3} on elastic and crystallization behavior of lithium diborate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Shaaban, KH.S.; Abd Elnaeim, A.M. [El-Azhar University, Physics Department, Faculty of Science, Assiut (Egypt); Abo-naf, S.M. [National Research Centre, Glass Research Department, Cairo (Egypt); Hassouna, M.E.M. [Beni-Suef University, Chemistry Department, Faculty of Science, Beni Suef (Egypt)

    2017-06-15

    The effect of MoO{sub 3} addition on the crystallization characteristics of 2Al{sub 2}O{sub 3}-23Li{sub 2}O-(75 - x) B{sub 2}O{sub 3} glass (where x MoO{sub 3} = 0, 10, 20, and 40 mol %) has been investigated. The compositional dependence of the glass transition (T{sub g}), and crystallization (T{sub c}) temperatures was determined by the differential thermal analysis (DTA). It was found that both the T{sub g} and T{sub c} decrease with increasing MoO{sub 3} content. The amorphous nature of the as-quenched glass and crystallinity of the produced glass-ceramics were confirmed by X-ray powder diffraction (XRD) analysis. Glass-ceramics embedded with diomignite (lithium diborate, Li{sub 2}B{sub 4}O{sub 7}) were produced from all investigated glasses by heat-treating the as-quenched glasses at the appropriate temperatures obtained from the DTA traces. Addition of MoO{sub 3} to the glass composition at 10% MoO{sub 3}, causes the formation of lithium molybdenum oxide (Li{sub 4}MoO{sub 5}) crystalline phase in addition to the diomignite phase. Increasing MoO{sub 3} content to 20% causes a phase transformation of lithium molybdenum oxide from the (Li{sub 4}MoO{sub 5}) to the (Li{sub 2}MoO{sub 4}) phase and the formation of another lithium borate (Li{sub 4}B{sub 2}O{sub 5}) phase in addition to the diomignite. Further increase of MoO{sub 3} content to 40% results in another phase transformation to the lithium aluminum molybdenum oxide [LiAl(MoO{sub 4}){sub 2}], and, in this case, the molybdenum content was excess enough to crystallize the molybdate (MoO{sub 3}) itself. Scanning electron microscopy (SEM) was used to characterize the morphology and microstructure of the formed solid solution phases. The values of the T{sub g} decrease with increasing the MoO{sub 3} content. The ultrasonic wave velocities and elastic moduli were determined using the pulse-echo method. Both velocities (v{sub L} and v{sub T}) were increased as the MoO{sub 3} content, this increase can be

  14. Differences in the sensitivity of children and adults to carciogenic substances - literature study; Unterschiede in der Empfindlichkeit von Kindern gegenueber krebserzeugenden Stoffen im Vergleich zu Erwachsenen - Literaturstudien

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, K. [Forschungs- und Beratungsinstitut Gefahrstoffe GmbH (FoBiG), Freiburg (Germany)

    1999-06-01

    Wirkungen durch radioaktive Strahlung ist belegt, dass exponierte Kinder im Vergleich zu Erwachsenen eine hoehere Empfindlichkeit fuer Brustkrebs, Leukaemie und Schilddruesentumoren aufweisen. In Bezug auf chemische Stoffe stammen relevante Hinweise aus tierexperimentellen Untersuchungen mit Vinylchlorid und anderen Substanzen (z.B. Nitrosamine und -amide, PAK, 2-Acetylaminofluoren, Benzidin, Aflatoxin B{sub 1}, Cycasin, Urethan), die hoehere Tumorinzidenzen bei Exposition junger Tiere ergaben als bei erwachsenen Tieren unter vergleichbaren Expositionsbedingungen. Alle genannten Substanzen sind gentoxische Kanzerogene und mechanistische Studien lassen es plausibel erscheinen, dass hohe Zellteilungsraten in den Organen des wachsenden Organismus in Verbindung mit der gentoxischen Aktivitaet der Stoffe zu hohen Tumorinzidenzen fuehren. Fuer das nicht gentoxisch wirkende Blasenkanzerogen Saccharin zeigt eine Studie, dass zusaetzliche Exposition vor und nach der Geburt zu einer hoeheren Tumorinzidenz fuehrt, als ausschliessliche Exposition erwachsener Tiere. Untersuchungen mit anderen nicht gentoxischen Stoffen ergaben unter aehnlichen Bedingungen keinen entsprechenden Befund. Die vorliegenden Daten weisen auf eine hohe Empfindlichkeit des kindlichen Organismus gegenueber bestimmten (gentoxischen) Kanzerogenen hin. Wenn Kinder gegenueber diesen Stoffen exponiert sind, ist deshalb auch bei Exposition ueber kuerzere Zeitraeume ein hohes Krebsrisiko nicht auszuschliessen. (orig.)

  15. INTERHEART STUDY

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. INTERHEART STUDY. About 90% of CHD Risk (“PAR”) can be explained by 9 Risk Factors: Smoking. Dyslipidemia. High BP. Diabetes. Abdominal Obesity. Psychosocial Factors. Fruits & Vegetables. Exercise. Alcohol.

  16. ACTIVITY STUDIES

    African Journals Online (AJOL)

    2-HYDROXY-4-METHOXYBENZALDEHYDE: LARVICIDAL STRUCTURE-. ACTIVITY STUDIES. Geoffrey M. Mahangal, Teresa O. Akengal, Wilber Lwandez, Isaiah 0. ... 2Behavioural and Chemical Ecology Department, International Centre for Insect Physiology and .... Y = mean death count, X = initial larvae population'.

  17. Floodplain Study

    Data.gov (United States)

    Montgomery County of Maryland — The purpose of a floodplain study is to establish the 100-year floodplain limits within or near a development in order to preserve the natural resources within the...

  18. Actuarial Studies

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Office of the Actuary in the Centers for Medicare and Medicaid Services (CMS) from time to time conducts studies on various aspects of the Medicare and Medicaid...

  19. European Studies

    Directory of Open Access Journals (Sweden)

    V. O. Pechatnov

    2014-01-01

    Full Text Available The study of Western countries and teaching courses on the related subjects have longstanding and established tradition at MGIMO-University. The basis of this brilliant research and teaching tradition was laid down by such academicians as E.V. Tarle and V.G. Trukhanovsky, Professor L.I. Clove, Y. Borisov, F.I. Notovitch, G.L. Rozanov. Their work in 1940-1960's at the Department of World History at MGIMO-University progressed in following directions: France studies, German studies, American studies. The work resulted in a number of monographs and textbooks on modern history and foreign policy of the studied countries and regions. The aim of the publications was dictated by the goal of the Institute - to prepare the specialists in international affairs primarily for practical work. A close relationship with the Foreign Ministry was "binding advantage" sometimes limiting researchers in choosing periods and subjects for the study. At the same time the undisputed advantage and quality of regional studies at MGIMO were strengthened by the practical relevance of research, making it a vital and interesting not only for specialists but also for students and researchers from other research centers. Another characteristic of the tradition is the analysis of foreign policy and diplomacy in a close relationship with the socio-economic and political processes. Such an integrated approach to regional geography also formed largely under the influence of institutional profile designed to train highly skilled and versatile specialists in specific countries and regions with a good knowledge of their languages, history, economics, politics, law and culture. Therefore, scientific and educational-methodical work at MGIMO-University has always relied on a wealth of empirical data and has been focused on the analysis of real-world phenomena and processes, acute problems of foreign countries. Scientific research at MGIMO-University traditionally intertwined with

  20. Clinical Studies

    DEFF Research Database (Denmark)

    Pallesen, Ulla

    universities and practicing dentists restore millions of teeth throughout the World with composite resin materials. Do we know enough about the clinical performance of these restorations over time? Numerous in vitro studies are being published on resin materials and adhesion, some of them attempting to imitate...... and results from own up to 30-year prospective clinical university studies and practice based studies from Public Dental Health Service on the clinical performance of posterior composite resin restorations.......Within the last 25 years composite resin materials have in many countries successively replaced amalgam as a restorative for posterior teeth. Resin materials and bonding systems are continuously being improved by the manufactures, adhesive procedures are now included in the curriculum of most...

  1. Studying Sideways

    DEFF Research Database (Denmark)

    Plesner, Ursula

    2011-01-01

    inequalities in relation to the people we study. This article argues that not all types of social scientific research interviews benefit from an à priori problematization of power and control, ethics and equality, or emancipation. From a constructivist perspective, the article seeks to displace...... and researched share professional background to some degree, where negotiations replace a researcher-imposed dialogue, and where the circulation of shared or common concepts messes up an orderly division between researchers’ vocabulary and interviewees’ vocabularies. It is proposed that when we study sideways...

  2. Study Proposal

    African Journals Online (AJOL)

    MATHEMATICS DEPARTMENT

    Msc in Mathematics Faculty of Education, Jimma University, Jimma, Ethiopia. P. O. Box 378 ..... Inquiry was made to know factors affecting their study of mathematics ..... mathematics. English language for teaching mathematics must start right at. 7th grade, and make it practical and applied. ▫ In Ethiopia we have no system of.

  3. Study Strategies

    DEFF Research Database (Denmark)

    Nielsen, Camilla Kirketerp; Noer, Vibeke Røn

    ID: 1277 / 22 SES 06 B: 2 22. Research in Higher Education Format of Presentation: Paper Alternative EERA Network: 19. Ethnography Topics: NW 22: Teaching, learning and assessment in higher education Keywords: Profession-oriented learning, study strategies, professionalisation processes, comparat......ID: 1277 / 22 SES 06 B: 2 22. Research in Higher Education Format of Presentation: Paper Alternative EERA Network: 19. Ethnography Topics: NW 22: Teaching, learning and assessment in higher education Keywords: Profession-oriented learning, study strategies, professionalisation processes......, comparative cross-disciplinary ethnography Study Strategies – Crossing Contexts Camilla Kirketerp Nielsen 1, Vibeke Røn Noer 2,1 1 University of Copenhagen, Denmark; 2 VIA University College Presenting Author: Kirketerp Nielsen, Camilla; Røn Noer, Vibeke This paper provides comparative cross...... module”. The projects differ in terms of both starting point and main focus of research (an alternative educational model and profession-orientated Game-based learning). However, in the on-going process of research, an empirical ´harmony´ on common recurrent themes related to students `study strategies...

  4. CASE STUDY

    African Journals Online (AJOL)

    BY TOXOPLASMOSIS. CASE STUDY. Christine Katusiime1, MB ChB, PGDPPM. Ponsiano Ocama2, MB ChB, MMed. Andrew Kambugu1, MB ChB, MMed. 1Makerere University, College of Health Sciences, Infectious Diseases Institute, Kampala, Uganda. 2Makerere University, College of Health Sciences, Department of ...

  5. Club studies

    DEFF Research Database (Denmark)

    Demant, Jakob Johan; Ravn, Signe; Harder, Sidsel Kirstine

    2010-01-01

    suggests a mixed-methods approach to club studies that combine quantitative data, qualitative interviews and ethnography conducted in the club space. By introducing the concept of ‘socionautics', this review suggests that the researcher travels into the social landscape of youth, clubs and drugs...

  6. Colour Studies

    African Journals Online (AJOL)

    DR Nneka

    2015-04-14

    Apr 14, 2015 ... colour thus: Color can sway thinking, change actions, and cause reactions. It can irritate or soothe your eyes, raise your blood pressure and suppress ... object and something like a fire from the eye, which sees as a spirit or soul ..... Finally, the study of one's own subjective colour preferences and the field of.

  7. CASE STUDY

    African Journals Online (AJOL)

    2011-06-02

    AIDS Control Programme, Sri Lanka. CASE STUDY. A 49-year-old male security supervisor was admitted to hospital with recurrent chest infections. He was found to be HIV positive with a CD4 count of 60 cells/µl, and was.

  8. Studying CO

    NARCIS (Netherlands)

    Boullenger, B.; Verdel, A.; Paap, B.; Thorbecke, J.; Draganov, D.

    2014-01-01

    Seismic interferometry applied to ambient-noise measurements allows the retrieval of the seismic response between pairs of receivers. We studied ambient-noise seismic interferometry (ANSI) to retrieve time-lapse reflection responses from a reservoir during CO2 geologic sequestration,

  9. Research Study

    Science.gov (United States)

    Glick, Ashley

    2010-01-01

    Background: Action Research about my 2nd grade classroom in the Buffalo School District. I examined three areas of interest and tried to find some conclusions related to behavior management. Purpose: The purpose of this study is how will implementing procedures, rules, and consequences help improve student behavior. Research Design: Descriptive;…

  10. Study protocol

    DEFF Research Database (Denmark)

    Madsen, Helle Østergaard; Dam, Ole Henrik; Hageman, Ida

    2012-01-01

    yields a Global Seasonal Score and a prevalence of SAD. Outcomes from the two groups will be compared. Moreover, outcomes from subgroups of the visually impaired population will be compared. ETHICS AND DISSEMINATION: The study is approved by the Danish Data Protection Agency. Results will be published...

  11. Based Study

    African Journals Online (AJOL)

    A prospective community-based study of pregnant women in rural communi- ties of south central Ethiopia ... pregnancy outcome were stillbirth (19/1000 births), perinatal mortality (45/1000 births) and neonatal mortality (37/1000 live births). Poor birth ..... ated widi maternal under-nutrition and age (teen- agers giving birdi to ...

  12. Study protocol

    DEFF Research Database (Denmark)

    Thorsteinsson, Troels; Helms, Anne Sofie; Adamsen, Lis

    2013-01-01

    . Secondary endpoints are quality of life measured by validated questionnaires and interviews, and physical performance. RESPECT includes a multimodal intervention program, including ambassador-facilitated educational, physical, and social interventions. The educational intervention includes an educational...... to interaction with peers.Methods/design: The RESPECT study is a nationwide population-based prospective, controlled, mixed-methods intervention study looking at children aged 6-18 years newly diagnosed with cancer in eastern Denmark (n = 120) and a matched control group in western Denmark (n = 120). RESPECT...... program aimed at the child with cancer, the child's schoolteachers and classmates, and the child's parents. Children with cancer will each have two ambassadors assigned from their class. The ambassadors visit the child with cancer at the hospital at alternating 2-week intervals and participate...

  13. Project studies

    DEFF Research Database (Denmark)

    Geraldi, Joana; Söderlund, Jonas

    2018-01-01

    Project organising is a growing field of scholarly inquiry and management practice. In recent years, two important developments have influenced this field: (1) the study and practice of projects have extended their level of analysis from mainly focussing on individual projects to focussing on micro......- as well as macro-level concerns around projects; and (2) there has been a greater interest in different kinds of scholarly inquiry. Taken together, these two developments call for closer scrutiny of how the levels of analysis and the types of inquiry are related and benefit each other...... project research: (1) levels of analysis; and (2) type of research. Analysing recent developments within project studies, we observe the emergence of what we refer to as type 3 research, which reconciles the need for theoretical development and engagement with practice. Type 3 research suggests pragmatic...

  14. Invisibility Studies

    DEFF Research Database (Denmark)

    Invisibility Studies explores current changes in the relationship between what we consider visible and what invisible in different areas of contemporary culture. Contributions trace how these changes make their marks on various cultural fields and investigate the cultural significance...... conditioned by physical and social settings that create certain possibilities for visibility and visuality, yet exclude others. The richness and complexity of this cultural framework means that no single discipline or interdisciplinary approach could capture it single-handedly. Invisibility Studies begins...... this conversation by bringing together scholars across the fields of architectural history and theory, art, film and literature, philosophy, cultural theory and contemporary anthropology as well as featuring work by a collective of artists....

  15. Security Studies

    OpenAIRE

    ,

    2005-01-01

    Security Studies has firmly established itself as a leading journal on international security issues. The journal publishes theoretical, historical and policy-oriented articles on the causes and consequences of war, and the sources and conditions of peace. The journal has published articles on balancing vs. bandwagoning, deterrence in enduring rivalries, the Domino theory, nuclear weapons proliferation, civil-military relations, political reforms in China, strategic culture in Asia and the P...

  16. Study of the p+{sup 12}C reaction at energies up to 30 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Masahide; Yamamoto, A.; Yoshioka, S. [Kyushu Univ., Fukuoka (Japan)] [and others

    1998-03-01

    Double differential cross sections of charged-particles emitted in the p+{sup 12}C reaction were measured in the energy region from 14 to 26 MeV. The observed continuous components of emitted protons and {alpha}-particles were analyzed by assuming sequential decay of intermediate reaction products and/or simultaneous breakup process. It was found that the three body simultaneous decay, p+{alpha}+{sup 8}Be, and the sequential decay via p+{sup 12}C{sup *}{sub 3-} and {alpha}+{sup 9}B{sub g.s.} are most important in the proton-induced breakup of {sup 12}C for energies up to 30 MeV. (author)

  17. Physical and optical absorption studies of Fe{sup 3+} - ions doped lithium borate glasses containing certain alkaline earths

    Energy Technology Data Exchange (ETDEWEB)

    Bhogi, Ashok [VNR Vignana Jyothi Institute of Engineering and Technology, Hyderabad, Telangana (India); Kumar, R. Vijaya [School of Physics, University of Hyderabad, Hyderabad, Telangana (India); Kistaiah, P., E-mail: pkistaiah@yahoo.com [Department of Physics, Osmania University, Hyderabad, Telangana (India)

    2016-05-23

    Iron ion doped lithium borate glasses with the composition 15RO-25Li{sub 2}O-59B{sub 2}O{sub 3}-1Fe{sub 2}O{sub 3} (where R= Ca, Sr and Ba) have been prepared by the conventional melt quenching technique and characterized to investigate the physical and optical properties using XRD, density, molar volume and UV-Visible spectroscopy. The optical absorption spectra exhibit a band at around 460 nm which is assigned to {sup 6}A{sub 1g}(S) → 4E{sub g} (G) of Fe{sup 3+} ions with distorted octahedral symmetry. From ultraviolet absorption edges, the optical band gap and Urbach energies have been evaluated. The effect of alkaline earths on these properties is discussed.

  18. FP-LAPW study of structural, electronic, elastic, mechanical and thermal properties of AlFe intermetallic

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Ekta, E-mail: jainekta05@gmail.com [Department of Physics, Government M. L. B. Girls P. G. Autonomous College, Bhopal-462002 (India); Pagare, Gitanjali, E-mail: gita-pagare@yahoo.co.in [Department of Physics, Sarojini Naidu Government Girls P. G. Autonomous College, Bhopal-462016 (India); Sanyal, S. P., E-mail: sps.physicsbu@gmail.com [Department of Physics, Barkatullah University, Bhopal-462026 (India)

    2016-05-06

    The structural, electronic, elastic, mechanical and thermal properties of AlFe intermetallic compound in B{sub 2}-type (CsCl) structure have been investigated using first-principles calculations. The exchange-correlation term was treated within generalized gradient approximation. Ground state properties i.e. lattice constants (a{sub 0}), bulk modulus (B) and first-order pressure derivative of bulk modulus (B’) are presented. The density of states are derived which show the metallic character of present compound. Our results for C{sub 11}, C{sub 12} and C{sub 44} agree well with previous theoretical data. Using Pugh’s criteria (B/G{sub H} < 1.75), brittle character of AlFe is satisfied. In addition shear modulus (G{sub H}), Young’s modulus (E), sound wave velocities and Debye temperature (θ{sub D}) have also been estimated.

  19. B mesons phenomenology and lattice QCD; Phenomenologie des mesons B et chromodynamique quantique sur reseau

    Energy Technology Data Exchange (ETDEWEB)

    Blossier, B

    2006-06-15

    We have studied some phenomenological aspects of the B meson physics by using lattice QCD, which is a non perturbative method (based on the first principles of Quantum Field Theory) of computing Green functions of the theory. Pionic couplings g{sub 1} and g{sub 2}, parameterizing the effective chiral Lagrangian which describes interactions between heavy-light mesons and soft pions, have been computed beyond the quenched approximation (at N{sub f} = 2). We have renormalized the operator q-bar{gamma}{sub {mu}}{gamma}{sup 5}q non perturbatively by using chiral Ward identities. We obtain g{sub 1} = 0.4/0.6 and g{sub 2} = -0.1/-0.3. We have estimated from an un-quenched simulation (at N{sub f} = 2) the strange quark mass: the non perturbative renormalisation scheme RI-MOM has been applied. After the matching in the MS scheme the result is m{sub s}(2 GeV) = 101 {+-} 8(-0,+25) MeV. We have proposed a method to calculate on the lattice the Heavy Quark Effective Theory form factors of the semileptonic transitions B {yields} D{sup **} at zero recoil. The renormalisation constant of the operator h-bar{gamma}{sub i}{gamma}{sup 5}D{sub j}h has been computed at one-loop order of the perturbation theory. We obtain {tau}{sub 1/2}(1) = 0.3/0.5 and {tau}{sub 3/2}(1) 0.5/0.7. Eventually the bag parameter B{sub B{sub s}} associated the B{sub s} - B{sub s}-bar mixing amplitude in the Standard Model has been estimated in the quenched approximation by using for the strange quark an action which verifies the chiral symmetry at finite lattice spacing a. Thus systematic errors are significantly reduced in the renormalisation procedure because the spurious mixing of the four-fermion operator h-bar{gamma}{sub {mu}}{sub L}qh-bar{gamma}{sub {mu}}{sub L}q with four-fermion operators of different chirality is absent. The result is B{sub B{sub s}} = 0.92(3). (author)

  20. Studying Emerge

    DEFF Research Database (Denmark)

    Davies, Sarah Rachael; Selin, Cynthia; Rodegher, Sandra

    2015-01-01

    The Emerge event, held in Tempe, AZ in March 2012, brought together a range of scientists, artists, futurists, engineers and students in order to experiment with innovative methods for thinking about the future. These methodological techniques were tested through nine workshops, each of which made...... use of a different format; Emerge as a whole, then, offered an opportunity to study a diverse set of future-oriented engagement practices. We conducted an event ethnography, in which a team of 11 researchers collaboratively developed accounts of the practices at play within Emerge and its workshops...

  1. Economic Studies

    Directory of Open Access Journals (Sweden)

    A. V. Kholopov

    2014-01-01

    Full Text Available The establishment of the School of Economic Science at MGIMO was due to the necessity of the world economy research, and the need to prepare highly skilled specialists in international economics. The school is developing a number of areas, which reflect the Faculty structure. - Economic theory is one of the most important research areas, a kind of foundation of the School of Economic Science at MGIMO. Economic theory studies are carried out at the chair of Economic theory. "The course of economic theory" textbook was published in 1991, and later it was reprinted seven times. Over the past few years other textbooks and manuals have been published, including "Economics for Managers" by Professor S.N. Ivashkovskaya, which survived through five editions; "International Economics" - four editions and "History of Economic Thought" - three editions. - International Economic Relations are carried out by the Department of International Economic Relations and Foreign Economic Activity. Its establishment is associated with the prominent economist N.N. Lyubimov. In 1957 he with his colleagues published the first textbook on the subject which went through multiple republications. The editorial team of the textbook subsequently formed the pride of Soviet economic science - S.M. Menshikov, E.P. Pletnev, V.D. Schetinin. Since 2007, the chair of Foreign Economic Activities led by Doctor of Economics, Professor I. Platonova has been investigating the problems of improving the architecture of foreign economic network and the international competitiveness of Russia; - The history of the study of problems of the world economy at MGIMO begins in 1958 at the chair baring the same name. Since 1998, the department has been headed by Professor A. Bulatov; - The study of international monetary relations is based on the chair of International Finance, and is focused on addressing the fundamental scientific and practical problems; - The chair "Banks, monetary circulation

  2. Law Studies

    Directory of Open Access Journals (Sweden)

    G. P. Tolstopiatenko

    2014-01-01

    Full Text Available At the origin of the International Law Department were such eminent scientists, diplomats and teachers as V.N. Durdenevsky, S.B. Krylov and F.I. Kozhevnikov. International law studies in USSR and Russia during the second half of the XX century was largely shaped by the lawyers of MGIMO. They had a large influence on the education in the international law in the whole USSR, and since 1990s in Russia and other CIS countries. The prominence of the research of MGIMO international lawyers was due to the close connections with the international practice, involving international negotiations in the United Nations and other international fora, diplomatic conferences and international scientific conferences. This experience is represented in the MGIMO handbooks on international law, which are still in demand. The Faculty of International Law at MGIMO consists of seven departments: Department of International Law, Department of Private International and Comparative Law; Department of European Law; Department of Comparative Constitutional Law; Department of Administrative and Financial Law; Department of Criminal Law, Department Criminal Procedure and Criminalistics. Many Russian lawyers famous at home and abroad work at the Faculty, contributing to domestic and international law studies. In 1947 the Academy of Sciences of the USSR published "International Law" textbook which was the first textbook on the subject in USSR. S.B. Krylov and V.N. Durdenevsky were the authors and editors of the textbook. First generations of MGIMO students studied international law according to this textbook. All subsequent books on international law, published in the USSR, were based on the approach to the teaching of international law, developed in the textbook by S.B. Krylov and V.N. Durdenevsky. The first textbook of international law with the stamp of MGIMO, edited by F.I. Kozhevnikov, was published in 1964. This textbook later went through five editions in 1966, 1972

  3. Conceptual study

    Energy Technology Data Exchange (ETDEWEB)

    Harty, H.

    1978-09-01

    This appendix is a compendium of topical reports prepared for the Hanford Nuclear Energy Center: Status Report: Conceptual Fuel Cycle Studies for the Hanford Nuclear Energy Center; Selection of Heat Disposal Methods for a Hanford Nuclear Energy Center; Station Service Power Supply for a Hanford Nuclear Energy Center (HNEC); Impact of a Hanford Nuclear Energy Center on Ground Level Fog and Humidity; A Review of Potential Technology for the Seismic Characterization of Nuclear Energy Centers; Reliability of Generation at a Hanford Nuclear Energy Center (HNEC); Meteorological Evaluation of Multiple Reactor Contamination Probabilities for a Hanford Nuclear Energy Center; Electric Power Transmission for a Hanford Nuclear Energy Center (HNEC); The Impact of a Hanford Nuclear Energy Center on Cloudiness and Insolation; and A Licensing Review for an HNEC.

  4. Studying antimatter

    CERN Multimedia

    CERN. Geneva

    2006-01-01

    Antiparticles are a crucial ingredient of particle physics and cosmology. Almost 80 years after Dirac’s bold prediction and the subsequent discovery of the positron in 1932, antiparticles are still in the spotlight of modern physics. This lecture for non-specialists will start with a theoretical and historical introduction. Why are antiparticles needed? When and how were they discovered? Why is the (CPT) symmetry between particles and antiparticles so fundamental? What is their role in cosmology? The second part will give an overview about the many aspects of antiparticles in experimental physics: their production, their use in colliders; as a probe inside atoms or nuclei; or as an object to study fundamental symmetries. In the third part, the lecture will focus on results and challenges of the “antimatter” programme at the Antiproton Decelerator (AD), with special emphasis on antihydrogen production, trapping and precision measurements.

  5. Treatability studies

    DEFF Research Database (Denmark)

    Bennedsen, Lars Rønn; Studds, Phil

    implementation of the preferred remedial technology.    In stead of selecting a full scale technique solely based on information collated during a literature research it is best practice to supplement the remediation screening phase with laboratory and in situ pilot treatability tests. As well as establishing......The fundamental information that a well-designed treatability study can provide is essential to the success of all remediation systems. Over the past years several new techniques for in situ and on site remediation of contaminated soil and groundwater have been used with varying degrees of success....... Based on the wide selection of different techniques several screening matrices have been developed in order to make it easier to choose the best suited technique for a given situation. However, these matrices only provide an indication of which technology that might be effective and often the assessor...

  6. Modeling of wear behavior of Al/B{sub 4}C composites produced by powder metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Ismail; Bektas, Asli [Gazi Univ., Ankara (Turkey). Dept. of Industrial Design Engineering; Guel, Ferhat; Cinci, Hanifi [Gazi Univ., Ankara (Turkey). Dept. of Materials and Metallurgy Engineering

    2017-06-01

    Wear characteristics of composites, Al matrix reinforced with B{sub 4}C particles percentages of 5, 10,15 and 20 produced by the powder metallurgy method were studied in this study. For this purpose, a mixture of Al and B{sub 4}C powders were pressed under 650 MPa pressure and then sintered at 635 C. The analysis of hardness, density and microstructure was performed. The produced samples were worn using a pin-on-disk abrasion device under 10, 20 and 30 N load through 500, 800 and 1200 mesh SiC abrasive papers. The obtained wear values were implemented in an artificial neural network (ANN) model having three inputs and one output using feed forward backpropagation Levenberg-Marquardt algorithm. Thus, the optimum wear conditions and hardness values were determined.

  7. Lattice dynamics of {alpha} boron and of boron carbide; Proprietes vibrationnelles du bore {alpha} et du carbure de bore

    Energy Technology Data Exchange (ETDEWEB)

    Vast, N

    1999-07-01

    The atomic structure and the lattice dynamics of {alpha} boron and of B{sub 4}C boron carbide have been studied by Density Functional Theory (D.F.T.) and Density Functional Perturbation Theory (D.F.P.T.). The bulk moduli of the unit-cell and of the icosahedron have been investigated, and the equation of state at zero temperature has been determined. In {alpha} boron, Raman diffusion and infrared absorption have been studied under pressure, and the theoretical and experimental Grueneisen coefficients have been compared. In boron carbide, inspection of the theoretical and experimental vibrational spectra has led to the determination of the atomic structure of B{sub 4}C. Finally, the effects of isotopic disorder have been modeled by an exact method beyond the mean-field approximation, and the effects onto the Raman lines has been investigated. The method has been applied to isotopic alloys of diamond and germanium. (author)

  8. Systems Studies

    Energy Technology Data Exchange (ETDEWEB)

    Graham, R.L.

    1998-03-17

    The Systems Studies Activity had two objectives: (1) to investigate nontechnical barriers to the deployment of biomass production and supply systems and (2) to enhance and extend existing systems models of bioenergy supply and use. For the first objective, the Activity focused on existing bioenergy markets. Four projects were undertaken: a comparative analysis of bioenergy in Sweden and Austria; a one-day workshop on nontechnical barriers jointly supported by the Production Systems Activity; the development and testing of a framework for analyzing barriers and drivers to bioenergy markets; and surveys of wood pellet users in Sweden, Austria and the US. For the second objective, two projects were undertaken. First, the Activity worked with the Integrated BioEnergy Systems (TBS) Activity of TEA Bioenergy Task XIII to enhance the BioEnergy Assessment Model (BEAM). This model is documented in the final report of the IBS Activity. The Systems Studies Activity contributed to enhancing the feedstock portion of the model by developing a coherent set of willow, poplar, and switchgrass production modules relevant to both the US and the UK. The Activity also developed a pretreatment module for switchgrass. Second, the Activity sponsored a three-day workshop on modeling bioenergy systems with the objectives of providing an overview of the types of models used to evaluate bioenergy and promoting communication among bioenergy modelers. There were nine guest speakers addressing different types of models used to evaluate different aspects of bioenergy, ranging from technoeconomic models based on the ASPEN software to linear programming models to develop feedstock supply curves for the US. The papers from this workshop have been submitted to Biomass and Bioenergy and are under editorial review.

  9. Study on

    Directory of Open Access Journals (Sweden)

    Razieh Pourdarbani

    2015-01-01

    Full Text Available In the present study, a machine vision based, online sorting system was developed, the aim being to sort Date fruits (Berhee CV. based at different stages of maturity, namely Khalal, Rotab and Tamar to meet consumers’ demands. The system comprises a conveying unit, illumination and capturing unit, and sorting unit. Physical and mechanical features were extracted from the samples provided, and the detection algorithm was designed accordingly. An index based on color features was defined to detect Date samples. Date fruits were fed on a conveyor belt in a row. When they were at the center of the camera’s field of view, a snapshot was taken, the image was processed immediately and the maturity stage of the Date was determined. When the Date passed the sensor, positioned at the end of the conveyor belt, a signal was sent to the interface circuit and an appropriate actuator, driven by a step motor, was actuated, leading the Date toward an appropriate port. For validation of proposed system performance, entire samples were again sorted by experts visually. Detection rate of the system for Tamar and Khalal was satisfactory. Although the detection rate was insufficient for the Rotab stage, there was no a significant difference between system accuracy and that obtained by the experts. The speed of image processing system was 0.34 s. System capacity was 15.45 kg/h.

  10. Studying toxicity

    Science.gov (United States)

    Elkus, A.; LeBlanc, L.; Kim, C.; Van Beneden, R.; Mayer, G.

    2006-01-01

    With funding from the George Mitchell Center for the Environment at the University of Maine, a team of scientists used a simple laboratory-based sediment resuspension design, and two well-established aquatic toxicology models, fathead minnows (Pimephales promelas) and zebrafish (Danio rerio), to evaluate if resuspension of Penobscot river sediment significantly elevates the toxicity of river water and to provide preliminary information on the types of chemicals likely to desorb during resuspension. The group collected sediments from two sites with known chemical contamination downstream of the Great Works and Veazie dams. The sediments were examined to determine the dynamics of PAH desorption and degradation under different resuspension frequencies. The scientists used clarified water from resuspension experiments for toxicity tests with the water-flea Ceriodaphnia dubia, and other aquatic test organisms to infer toxicity from sediments from northern California rivers. Data from the study will help ascertain whether metals and/or xenoestrogens are present in the desorption water and give insight into possible avenues of sediment remediation.

  11. Criticality assessment of basket designs for use in the MH-1A shipping cask

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J.T.

    1982-04-01

    An analytical study is made of a proposed stainless steel basket to be used in the MH-1A cask for the shipment of National Bureau of Standards reactor fuel elements. The use of B/sub 4/C in the basket as a primary control for the prevention of criticality is shown to be effective but not necessary. A basket fabricated of 0.635-cm-thick stainless steel provides a sufficient margin of subcriticality.

  12. Decay properties of charm and bottom mesons in a quantum isotonic nonlinear oscillator potential model

    Energy Technology Data Exchange (ETDEWEB)

    Rahmani, S.; Hassanabadi, H. [Shahrood University of Technology, Physics Department, Shahrood (Iran, Islamic Republic of)

    2017-09-15

    Employing generalized quantum isotonic oscillator potential we determine wave function for mesonic system in nonrelativistic formalism. Then we investigate branching ratios of leptonic decays for heavy-light mesons including a charm quark. Next, by applying the Isgur-Wise function we obtain branching ratios of semileptonic decays for mesons including a bottom quark. The weak decay of the B{sub c} meson is also analyzed to study the life time. Comparison with other available theoretical approaches is presented. (orig.)

  13. Microscopic thin-shell wormholes in magnetic Melvin universe

    Energy Technology Data Exchange (ETDEWEB)

    Mazharimousavi, S.H.; Halilsoy, M.; Amirabi, Z. [Eastern Mediterranean University, Department of Physics, North Cyprus, Mersin 10 (Turkey)

    2014-05-15

    We construct thin-shell wormholes in the magnetic Melvin universe. It is shown that in order to make a TSW in the Melvin spacetime the radius of the throat cannot be larger than (2)/(B{sub 0}), in which B{sub 0} is the magnetic field constant. We also analyze the stability of the constructed wormhole in terms of a linear perturbation around the equilibrium point. In our stability analysis we scan a full set of the Equation of States such as Linear Gas, Chaplygin Gas, Generalized Chaplygin Gas, Modified Generalized Chaplygin Gas, and Logarithmic Gas. Finally we extend our study to the wormhole solution in the unified Melvin and Bertotti-Robinson spacetime. In this extension we show that for some specific cases, the local energy density is partially positive but the total energy which supports the wormhole is positive. (orig.)

  14. Background dependence of dimuon asymmetry in p{sup Macron }p interactions at {radical}(s)=1.96 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Gronau, Michael, E-mail: gronau@physics.technion.ac.il [Physics Department, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Rosner, Jonathan L. [Enrico Fermi Institute and Department of Physics, University of Chicago, Chicago, IL 60637 (United States)

    2012-02-14

    The D0 Collaboration has reported an anomalous charge asymmetry in the production of same-sign muon pairs at the Fermilab Tevatron. The magnitude of this effect depends on the subtraction of several backgrounds, the most notable of which is due to kaons being misidentified as muons either through decays in flight or punch-through. The present authors suggested a check on such backgrounds consisting of a tight restriction on the muon impact parameter b, to confirm that this excess was indeed due to B{sub (s)} meson decays. The D0 Collaboration has performed a related check applying transverse impact parameter (IP) restrictions, whose implications are discussed. We study background asymmetry predictions for events involving two muons with IP bounds which are complementary to each other. These predictions may be used in future measurements of the net charge asymmetry from B{sub (s)} decays.

  15. Probing the pairing symmetry of the iron pnictides with electronic Raman scattering

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, G.R.

    2010-04-29

    An important issue in the study of the iron-arsenic based superconductors is the symmetry of the superconducting gap, a problem complicated by multiple gaps on different Fermi surface sheets. Electronic Raman scattering is a flexible bulk probe which allows one in principle to determine gap magnitudes and test for gap nodes in different regions of the Brillouin zone by employing different photon polarization states. Here we calculate the clean Raman intensity for A{sub 1g}, B{sub 1g} and B{sub 2g} polarizations, and discuss the peak structures and low-energy power laws which might be expected for several popular models of the superconducting gap in these systems.

  16. CDF Run I B physics results

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, S.

    2001-03-08

    The CDF Run I B physics program has been very successful, making numerous measurements over a wide variety of B physics topics. Measurements have included masses and lifetimes; discovery of the B{sub c}; B{sub s} {r_arrow} J/{psi}{phi} polarization; B{sup 0} {leftrightarrow} {bar B}{sup 0} mixing; sin (2{beta}); and rare decay limits. Recent results include a search for {Lambda}{sub b} {r_arrow} {Lambda}{gamma} and a study of B{sup 0} {r_arrow} J/{psi}K(*){sup 0} {pi}{sup +}{pi}{sup {minus}} decays. The tools and experience developed during Run I are quite valuable as CDF enters Run II.

  17. Magnetoimpedance of cobalt-based amorphous ribbons/polymer composites

    Energy Technology Data Exchange (ETDEWEB)

    Semirov, A.V., E-mail: semirov@mail.ru [Irkutsk State University, Irkutsk (Russian Federation); Derevyanko, M.S.; Bukreev, D.A.; Moiseev, A.A.; Kudryavtsev, V.O. [Irkutsk State University, Irkutsk (Russian Federation); Safronov, A.P. [Ural Federal University, Yekaterinburg (Russian Federation)

    2016-10-01

    The combined influence of the temperature, the elastic tensile stress and the external magnetic field on the total impedance and impedance components were studied for rapidly quenched amorphous Co{sub 75}Fe{sub 5}Si{sub 4}B{sub 16} ribbons. Both as-cast amorphous ribbons and Co{sub 75}Fe{sub 5}Si{sub 4}B{sub 16}/polymer amorphous ribbon based composites were considered. Following polymer coverings were studied: modified rubber solution in o-xylene, solution of butyl methacrylate and methacrylic acid copolymer in isopropanol and solution of polymethylphenylsiloxane resin in toluene. All selected composites showed very good adhesion of the coverings and allowed to provide temperature measurements from 163 K up to 383 K under the applied deforming tensile force up to 30 N. The dependence of the modulus of the impedance and its components on the external magnetic field was influenced by the elastic tensile stresses and was affected by the temperature of the samples. It was shown that maximal sensitivity of the impedance and its components to the external magnetic field was observed at minimal temperature and maximal deforming force depended on the frequency of an alternating current. - Highlights: • Impedance and its components of amorphous Co{sub 75}Fe{sub 5}Si{sub 4}B{sub 16} ribbons were studied. • MI sensitivity to the magnetic field depends on a temperature and a deforming force. • Polymer covering can affect the functional properties of the composite.

  18. Electron transport in coupled double quantum wells and wires

    Energy Technology Data Exchange (ETDEWEB)

    Harff, N.E.; Simmons, J.A.; Lyo, S.K. [and others

    1997-04-01

    Due to inter-quantum well tunneling, coupled double quantum wells (DQWs) contain an extra degree of electronic freedom in the growth direction, giving rise to new transport phenomena not found in single electron layers. This report describes work done on coupled DQWs subject to inplane magnetic fields B{sub {parallel}}, and is based on the lead author`s doctoral thesis, successfully defended at Oregon State University on March 4, 1997. First, the conductance of closely coupled DQWs in B{sub {parallel}} is studied. B{sub {parallel}}-induced distortions in the dispersion, the density of states, and the Fermi surface are described both theoretically and experimentally, with particular attention paid to the dispersion anticrossing and resulting partial energy gap. Measurements of giant distortions in the effective mass are found to agree with theoretical calculations. Second, the Landau level spectra of coupled DQWs in tilted magnetic fields is studied. The magnetoresistance oscillations show complex beating as Landau levels from the two Fermi surface components cross the Fermi level. A third set of oscillations resulting from magnetic breakdown is observed. A semiclassical calculation of the Landau level spectra is then performed, and shown to agree exceptionally well with the data. Finally, quantum wires and quantum point contacts formed in DQW structures are investigated. Anticrossings of the one-dimensional DQW dispersion curves are predicted to have interesting transport effects in these devices. Difficulties in sample fabrication have to date prevented experimental verification. However, recently developed techniques to overcome these difficulties are described.

  19. Magnetoelectric effect in antiferromagnetic multiferroic Pb(Fe.sub.1/2./sub. N b.sub.1/2./sub.)O.sub.3./sub. and its solid solutions with PbTi O.sub.3./sub.

    Czech Academy of Sciences Publication Activity Database

    Laguta, Valentyn; Stephanovich, V. A.; Raevski, I. P.; Raevskaya, S. I.; Titov, V.V.; Smotrakov, V. G.; Eremkin, V. V.

    2017-01-01

    Roč. 95, č. 1 (2017), 1-13, č. článku 014207. ISSN 1098-0121 R&D Projects: GA MŠk LO1409; GA MŠk LM2015088; GA ČR GA13-11473S Institutional support: RVO:68378271 Keywords : multiferroic * antiferromagnetic * ferroelectrics * magnetoelectric effect * Landau theory Subject RIV: BM - Solid Matter Physics ; Magnetism

  20. Correlations between critical current density, j{sub c}, critical temperature, T{sub c}, and structural quality of Y{sub 1}B{sub 2}Cu{sub 3}O{sub 7-x} thin superconducting films

    Energy Technology Data Exchange (ETDEWEB)

    Chrzanowski, J.; Xing, W.B.; Atlan, D. [Simon Fraser Univ., British Columbia (Canada)] [and others

    1994-12-31

    Correlations between critical current density (j{sub c}) critical temperature (T{sub c}) and the density of edge dislocations and nonuniform strain have been observed in YBCO thin films deposited by pulsed laser ablation on (001) LaAlO{sub 3} single crystals. Distinct maxima in j{sub c} as a function of the linewidths of the (00{ell}) Bragg reflections and as a function of the mosaic spread have been found in the epitaxial films. These maxima in j{sub c} indicate that the magnetic flux lines, in films of structural quality approaching that of single crystals, are insufficiently pinned which results in a decreased critical current density. T{sub c} increased monotonically with improving crystalline quality and approached a value characteristic of a pure single crystal. A strong correlation between j{sub c} and the density of edge dislocations N{sub D} was found. At the maximum of the critical current density the density of edge dislocations was estimated to be N{sub D}{approximately}1-2 x 10{sup 9}/cm{sup 2}.

  1. Luminescent properties of Ce{sup 3+}ions in Ca {sub 2}B {sub 5}O {sub 9}Cl

    Energy Technology Data Exchange (ETDEWEB)

    Dotsenko, V.P.; Berezovskaya, I.V.; Efryushina, N.P.; Shabanov, E.V. [A.V. Bogatsky Physico-Chemical Institute, Ukrainian Academy of Sciences, Lustdorfskaya doroga 86, 65080 Odessa (Ukraine); Voloshinovskii, A.S. [Lviv Franko State University, Kirilo i Mefodii 8, 79005 Lviv (Ukraine)

    2006-04-15

    The luminescent properties of Ce{sup 3+} ions in Ca{sub 2}B{sub 5}O{sub 9}Cl have been studied upon excitation in the 3.5-25 eV region. The energies of all 5d crystal field levels of Ce{sup 3+} ions in double doped Ca{sub 2}B{sub 5}O{sub 9}Cl:Ce{sup 3+}, Na{sup +} have been determined. In addition to the 4f {yields} 5d excitation bands, the excitation spectrum of the Ce{sup 3+} emission shows a band with a maximum at 7.7 eV, which is attributed to the absorption of the borate groups. The influence of the structural features of Ca{sub 2}B{sub 5}O{sub 9}Cl on the luminescent behavior of Ce{sup 3+} is discussed. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Crystallization processes in Fe-Pt-Nb-B melt spun ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Crisan, A.D. [National Institute for Materials Physics, PO Box MG-7, 77125 Bucharest (Romania); Institut fuer Physik, Universitaet Rostock, August-Bebel-Str. 55, 18055 Rostock (Germany); Crisan, O. [National Institute for Materials Physics, PO Box MG-7, 77125 Bucharest (Romania); Institut fuer Physik, Universitaet Rostock, August-Bebel-Str. 55, 18055 Rostock (Germany)], E-mail: ocrisan@yahoo.com; Randrianantoandro, N. [LPEC, UMR CNRS 6087, Universite du Maine, 72085 Le Mans Cedex 9 (France); Valeanu, M.; Morariu, M. [National Institute for Materials Physics, PO Box MG-7, 77125 Bucharest (Romania); Burkel, E. [Institut fuer Physik, Universitaet Rostock, August-Bebel-Str. 55, 18055 Rostock (Germany)

    2007-09-15

    Intermetallic Fe-Pt-Nb-B alloys with 3 different compositions have been synthesized by rapid solidification technique and their phase structure was characterized by means of X-ray diffraction and Moessbauer spectrometry. It is shown that Fe{sub 68}Pt{sub 21}Nb{sub 2}B{sub 9} and Fe{sub 65}Pt{sub 25}Nb{sub 2}B{sub 8} as-cast samples consist mainly of A1 soft magnetic f.c.c. Fe-Pt phase, while the Fe{sub 68}Pt{sub 13}Nb{sub 2}B{sub 17} as-cast sample exhibits topological short-range order, typical for amorphous ribbons. Crystallization processes in the amorphous sample and phase evolution with the temperature have been studied using differential scanning calorimetry (DSC). The occurrence of exothermic peaks is related to structural transformations in the alloys and the crystallization process is shown to be highly dependent upon the heating rate in the DSC process.

  3. Volatilization mechanism of certain elements in a method of semiquantitative spectrographic analysis; Mecanismo de volatilizacion de ciertos elementos en un metodo de analisis espectrografico semicuantitativo

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Guerra, J. P.

    1972-07-01

    The efficiency of the compounds GeO{sub 2}, Li{sub 2}B{sub 4}O{sub 7}, Li{sub 2}CO{sub 3}, SiO{sub 2} and SrCO{sub 3} as spectrochemical buffers, in the development of a semiquantitative spectrographic method of analysis, that can be applied to the determination of 47 elements in different matrices, has been tested. It has been shown that trough the use of Li{sub 2}B{sub 4}O{sub 7} or Geo{sub 2} adequate accuracy is obtained, attaining with the latter the detection of much lower concentrations, specially for the elements Mo. Ti, V and W. In order to account for the different behaviour of these elements their volatilization mechanism has been studied. MoB{sub 2}, TiB{sub 2}, VB{sub 2}.{delta}WB and {epsilon}-WB were found, by x-ray diffraction analysis, to be reaction products in the case of mixtures with Li{sub 2}B{sub 4}O{sub 7}. (Author)

  4. Combined Results on b-Hadron Production Rates and Decay Properties

    Energy Technology Data Exchange (ETDEWEB)

    Su, Dong

    2002-09-11

    Combined results on b-hadron lifetimes, b-hadron production rates, B{sub d}{sup 0}-{bar B}{sub d}{sup 0} and B{sub s}{sup 0}-{bar B}{sub s}{sup 0} oscillations, the decay width difference between the mass eigenstates of the B{sub s}{sup 0}-{bar B}{sub s}{sup 0} system, the average number of c and {bar c} quarks in b-hadron decays, and searches for CP violation in the B{sub d}{sup 0}-{bar B}{sub d}{sup 0} system are presented. They have been obtained from published and preliminary measurements available in Summer 2000 from the ALEPH, CDF, DELPHI, L3, OPAL and SLD Collaborations. These results have been used to determine the parameters of the CKM unitarity triangle.

  5. Pion couplings to the scalar B meson

    Energy Technology Data Exchange (ETDEWEB)

    Blossier, Benoit [Unite Mixte de Recherche 8627 du Centre National de la Recherche Scientifique, CNRS et Universite Paris-Sud XI, Laboratoire de Physique Theorique, Orsay Cedex (France); Garron, Nicolas [University of Cambridge, Department of Applied Mathematics and Theoretical Physics, Cambridge (United Kingdom); Gerardin, Antoine [Unite Mixte de Recherche 8627 du Centre National de la Recherche Scientifique, CNRS et Universite Paris-Sud XI, Laboratoire de Physique Theorique, Orsay Cedex (France); Unite Mixte de Recherche 6533 CNRS/IN2P3-Universite Blaise Pascal, Laboratoire de Physique Corpusculaire de Clermont-Ferrand, Campus des Cezeaux, 24 avenue des Landais, BP 80026, Aubiere Cedex (France)

    2015-03-01

    We present two-flavor lattice QCD estimates of the hadronic couplings g{sub B{sub 0{sup *}Bπ}} and g{sub B{sub 1{sup *}B{sub 0{sup *}π}}} that parametrize the non-leptonic decays B{sub 0}{sup *} → Bπ and B{sub 1}{sup *} → B{sub 0}{sup *}π. We use CLS two-flavor gauge ensembles. Our framework is the Heavy Quark Effective Theory (HQET) in the static limit and solving a Generalized Eigenvalue Problem (GEVP) reveals crucial to disentangle the B{sub 0}{sup *}(B{sub 1}{sup *}) state from the Bπ(B{sup *}π) state. This work brings us some experience on how to treat the possible contribution from multihadronic states to correlation functions calculated on the lattice, especially when S-wave states are involved. (orig.)

  6. Volume and surface symmetry energy coefficients from photoabsorption cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Lipparini, E.; Stringari, S. (Trento Univ. (Italy). Dipartimento di Fisica)

    1982-05-27

    We analyze the experimental data on the giant dipole resonance to extract the volume and surface symmetry energy coefficients bsub(vol) and bsub(surf) entering in the semi-empirical mass formula. The analysis is based on a hydrodynamic model and yields bsub(vol) = 66 MeV and bsub(surf) = 131 MeV in disagreement with recent mass-formula fits. The crucial role of surface effects on the static polarizability is discussed in detail.

  7. Rare B decays at CDF

    Energy Technology Data Exchange (ETDEWEB)

    Farrington, Sinead M.; /Liverpool U.

    2006-10-01

    The confidence level limits of the CDF search for the B{sub s}{sup 0} and B{sub d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} rare decays and the branching ratio measurement of B{sub s}{sup 0} {yields} D{sub s}{sup +} D{sub s}{sup -} are presented.

  8. Case Study: Testing with Case Studies

    Science.gov (United States)

    Herreid, Clyde Freeman

    2015-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue discusses using case studies to test for knowledge or lessons learned.

  9. Lead recovery and high silica glass powder synthesis from waste CRT funnel glasses through carbon thermal reduction enhanced glass phase separation process

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Mingfei [Henan Key Laboratory Cultivation Base of Mine Environmental Protection and Ecological Remediation, Henan Polytechnic University, Jiaozuo 454000 Henan China (China); Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000 Henan China (China); Fu, Zegang [Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000 Henan China (China); Wang, Yaping, E-mail: wangyp326@163.com [School of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo 454000, Henan China (China); Wang, Jingyu [Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000 Henan China (China); Zhang, Zhiyuan [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2017-01-15

    Highlights: • CRT funnel glass was remelted with B{sub 2}O{sub 3} in reducing atmosphere. • A part of PbO was reduced into Pb and detached from the glass phase. • The rest of PbO and other metal oxides were mainly concentrated in the B{sub 2}O{sub 3} phase. • PbO enriched in the interconnected B{sub 2}O{sub 3} phase can be completely leached out by HNO{sub 3}. • High silica glass powder(SiO{sub 2} purity >95%) was obtained after the leaching process. - Abstract: In this study, a novel process for the removal of toxic lead from the CRT funnel glass and synchronous preparation of high silica glass powder was developed by a carbon-thermal reduction enhanced glass phase separation process. CRT funnel glass was remelted with B{sub 2}O{sub 3} in reducing atmosphere. In the thermal process, a part of PbO contained in the funnel glass was reduced into metallic Pb and detached from the glass phase. The rest of PbO and other metal oxides (including Na{sub 2}O, K{sub 2}O, Al{sub 2}O{sub 3,} BaO and CaO) were mainly concentrated in the boric oxide phase. The metallic Pb phase and boric oxide phase were completely leached out by 5 mol/L HNO{sub 3}. The lead removal rate was 99.80% and high silica glass powder (SiO{sub 2} purity >95 wt%) was obtained by setting the temperature, B{sub 2}O{sub 3} added amount and holding time at 1000 °C, 20% and 30 mins, respectively. The prepared high silicate glass powders can be used as catalyst carrier, semipermeable membranes, adsorbents or be remelted into high silicate glass as an ideal substitute for quartz glass. Thus this study proposed an eco-friendly and economical process for recycling Pb-rich electronic glass waste.

  10. Luminescence studies of Dy{sup 3+} doped bismuth zinc borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugavelu, B.; Kumar, V.V. Ravi Kanth, E-mail: ravi.phy@pondiuni.edu.in

    2014-02-15

    Glasses having composition of (100−x) (1Bi{sub 2}O{sub 3}–1ZnO–1B{sub 2}O{sub 3})-xDy{sub 2}O{sub 3} (where x=0.1, 0.3, 0.5, 1 and 2 mol%) were prepared by melt quenching method and characterized through optical absorption, emission and decay curve measurements. Optical absorption spectra have been analyzed using Judd–Ofelt theory. Asymmetric ratio, the intensity ratio of yellow to blue transitions, has been calculated from the emission spectra to understand the symmetry around the Dy{sup 3+} ions in the glass matrix. The emission spectra have been analyzed in the framework of CIE 1931 chromaticity colour coordinates in order to find out the white light emission characteristics of the glasses. The decay curve measurements exhibit single exponential behaviour up to 1 mol% of Dy{sup 3+} ions whereas non exponential behaviour is observed for 2 mol% of Dy{sup 3+} ions. The non exponential curve has been fitted to the Inokuti–Hirayama model to understand the nature of energy transfer process. -- Highlights: • Luminescence quenching occurs at high concentration of Dy{sup 3+} ion. • The interaction between Dy{sup 3+} ions is of dipole–dipole type. • CIE chromaticity coordinates fall within the white light region.

  11. Nanocrystals and amorphous matrix phase studies of Finemet-like alloys containing Ge

    Energy Technology Data Exchange (ETDEWEB)

    Moya, J.A., E-mail: jmoya.fi.uba@gmail.co [IESIING, Facultad de Ingenieria e Informatica, UCASAL, A4402FYP Salta (Argentina); Lab. Solidos Amorfos, Facultad de Ingenieria, INTECIN, UBA-CONICET (Argentina); CONICET (Argentina)

    2010-07-15

    Two simple models were developed in order to determine the chemical composition of both nanocrystals and intergranular amorphous phases in nanocrystallized Fe{sub 73.5}Si{sub 13.5}B{sub 9}Nb{sub 3}Cu{sub 1} containing Ge using data from X-ray diffraction and Moessbauer spectroscopy techniques. Saturation magnetization of the amorphous intergranular matrix (M{sub s}{sup am}) was calculated considering the contribution of the alpha-Fe(Si,Ge) nanocrystals and saturation magnetization of the alloys. The behavior of M{sub s}{sup am} with the iron content of the matrix was obtained and discussed. The exchange stiffness constant for the nanograins and for the amorphous phases was determined. The increment in the coercive field (H{sub c}) with increasing Ge content was evaluated using two theoretical models for the random magnetocrystalline anisotropy constant (). Results show that the magnetic hardening observed could not be attributed to an increase in but mainly to an important increment of the magnetostriction constant of the alpha-Fe(Si,Ge) nanocrystals (lambda{sub s}{sup cr}). Values for lambda{sub s}{sup cr} are proposed.

  12. Study of the ^7_{Lambda}He hypernucleus in formalism of the Faddeev equations

    Energy Technology Data Exchange (ETDEWEB)

    Igor Filikhin; Vladimir M. Suslov; Branislav Vlahovic

    2006-02-01

    P-shell A = 7 hypernuclei are considered in the cluster {sub {Lambda}}{sup 5}He + N + N model. The folding procedure are applied to construct the {sub {Lambda}}{sup 5}He-N interaction. We use the OBE simulating NSC97f potential for {Lambda}N interaction and various phenomenological potentials for {alpha}{Lambda} interaction. Configuration space Faddeev calculations are performed for hyperon binding energy of the {sub {Lambda}}{sup 7}He(1/2{sup +}) and {sub {lambda}}{sup 7}Li(1/2{sup +} and 3/2{sup +}, T=0) nuclei. Predicted value for B{sub {Lambda}}({sub {Lambda}}{sup 7}He) is 5.35 MeV. This value is obtained when the {sup {Lambda}}{sup 6}He(2{sup -}) excitation energy is equal 0.26 MeV by the adjustment of pair {sub {Lambda}}{sup 5}He-N effective potential to reproduce the experimental value of the {sub {Lambda}}{sup 7}Li(3/2{sup +}) excitation energy. Our results are compared with those of E. Hiyama et al.

  13. Nanocomposite Nd-Y-Fe-B-Mo bulk magnets prepared by injection casting technique

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Shan [Magnetism Key Laboratory of Zhejiang Province, China Jiliang University, Hangzhou 310018 (China); Ahmad, Zubair [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Zhang, Pengyue [Magnetism Key Laboratory of Zhejiang Province, China Jiliang University, Hangzhou 310018 (China); Yan, Mi, E-mail: mse_yanmi@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Zheng, Xiaomei [Magnetism Key Laboratory of Zhejiang Province, China Jiliang University, Hangzhou 310018 (China)

    2017-09-01

    Highlights: • Nanocomposite Nd{sub 7}Y{sub 6}Fe{sub 61}B{sub 22}Mo{sub 4} sheet magnets were synthesized by injection casting. • High coercivity of 1289 kA/m was obtained for the directly casted magnet. • Magnetic properties arise from magnetically exchange coupled soft and hard phases. - Abstract: The phase composition, magnetic and microstructural properties of Nd{sub 2}Fe{sub 14}B/(α-Fe, Fe{sub 3}B) nanocomposite magnets produced by injection casting technique have been studied. Magnetic hysteresis loop of the Nd{sub 7}Y{sub 6}Fe{sub 61}B{sub 22}Mo{sub 4} permanent magnet demonstrates the coercivity as high as 1289 kA/m. Electron microscopy elucidates a microstructure composed of magnetically soft α-Fe, Fe{sub 3}B and hard Nd{sub 2}Fe{sub 14}B/Y{sub 2}Fe{sub 14}B nanograins (20–50 nm) separated by ultra-thin grain boundary layer. The Henkel plot curve of the Nd{sub 7}Y{sub 6}Fe{sub 61}B{sub 22}Mo{sub 4} magnet yields the existence of exchange coupling interactions between soft and hard phases. Macroscopically large size sheet magnet is obtained due to high glass forming ability of the Nd{sub 7}Y{sub 6}Fe{sub 61}B{sub 22}Mo{sub 4} alloy derived from large atomic radius mismatch and negative enthalpy of alloy constituent elements. The high coercivity of the magnet is attributed to the magnetically hard phase increment, nucleation of reverse domains and the presence of thin grain boundary phase. Good magnetic properties such as remanence of 0.51 T, coercivity of 1289 kA/m and maximum energy product of 46.2 kJ/m{sup 3} are obtained in directly casted Nd{sub 7}Y{sub 6}Fe{sub 61}B{sub 22}Mo{sub 4} sheet magnets.

  14. Effect of different uranium compounds on the properties of U-Pt-Y-Ba-O double-perovskite pinning centres in textured Y-Ba-Cu-O superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Sawh, Ravi-Persad; Weinstein, Roy; Parks, Drew; Gandini, Alberto [Beam Particle Dynamics Laboratories, University of Houston, Houston, TX 77204-5005 (United States); Department of Physics, University of Houston, Houston, TX 77204-5005 (United States); Texas Center for Superconductivity and Advanced Materials, University of Houston, Houston, TX 77204-5005 (United States)

    2005-02-01

    An experiment was performed to test the effect of different uranium compounds on the properties of chemical pinning centres. UO{sub 2}, UO{sub 3}, and UO{sub 4}{center_dot}2H{sub 2}O wereadmixed to Y 123+Pt, and textured. Tests of J{sub c} via measurements of trapped field (B{sub trap}) indicate a clear dependence of B{sub trap} on the U compound admixed to create the pinning centres. In all three cases there is a monotonic increase in B{sub trap} as the mass (M{sub U}) of U is increased. However, the magnitude of the increase in B{sub trap} depends on the admixed U compound. The highest increase in B{sub trap} is measured in samples doped with UO{sub 4}{center_dot}2H{sub 2}O, and the lowest is obtained in samples doped with UO{sub 2}. Microstructure studies indicate that the composition of the U-rich pinning deposits is the same in all three cases, i.e. all are the previously identified (U{sub 0.6}Pt{sub 0.4})Y Ba{sub 2}O{sub 6} compound. The primary difference among the three types of samples is that the size of the U-Pt-Y-Ba-O pinning deposits depends on the admixed U compound. While all are in the nanometre domain, the diameter of these deposits was markedly larger in UO{sub 2} doped samples than in UO{sub 3} doped samples, and smallest in UO{sub 4}{center_dot}2H{sub 2}O doped samples. Because some form of poisoning limits the amount of U that can be added to create pinning centres, to M{sub U} {approx}1 wt%, smaller deposits result in a greater number of pinning centres. We conclude that UO{sub 4}{center_dot}2H{sub 2}O is more effective than either UO{sub 3} or UO{sub 2} in the formation of U-Pt-Y-Ba-O pinning centres because of diminished pinning centre size, and consequent increase in pinning centre density.

  15. Characterization of the patterns of polymorphism in a [open quotes]cryptic repeat[close quotes] reveals a novel type of hypervariable sequence

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, D.P.; Schmeling, P.; Sommer, S.S. (Mayo Clinic/Foundation, Rochester, MN (United States))

    1993-08-01

    Alternating purine and pyrimidine repeats (RY(i)) are an abundant source of polymorphism. The subset with long tandem repeats of GT or AC (GT(i)) have been studied extensively, but cryptic RY(i) (i.e., no single tandem repeat predominates) have received little attention. The factor IX gene has a polymorphic cryptic RY(i) of 142-216 bp. Previously, there were four known polymorphic alleles, of the form AB, A[sub 2]B, A[sub 2]B[sub 2], and A[sub 3]B[sub 2], where A = (GT)(AC)[sub 3](AT)[sub 3](GT)(AT)[sub 4] and B = A with an additional 3' AT dinucleotide. To further characterize this locus, the authors examined more than 1,700 additional human chromosomes and determined the sequences of the homologous sites in orangutans and chimpanzees. The novel alleles found in humans expand the repertoire of A/B alleles to A[sub 0-4]B[sub 1] and A[sub 1-3]B[sub 2]. The A[sub n]B[sub 2] series are abundant in Caucasians but are absent in blacks and Asians. Conversely, the A[sub 0]B[sub 1] allele is common in blacks but is not found in more than 1,700 Caucasian chromosomes. The data are compatible with a model in which recombination is more frequent than polymerase slippage at this locus. In orangutans, the RY(i) is present, but the sequence is markedly different. An A/B-type of pattern was discerned in which B differs from A by an additional six (AT) dinucleotides at the 3' end. In chimpanzees, the size of the RY(i) locus was greatly expanded, and the sequence showed a novel pattern of hypervariability in which there are many tandem repeats of the form (GT)[sub n](AC)[sub 0](AT)[sub p](GT)[sub q](AT)[sub s], where n, o, p, q, and s are different integers. The sequences of the factor IX intron 1 cryptic RY(i) in three primates provide perspective on the range of possible patterns of polymorphism. Analysis of the patterns suggests how the RY(i) can be conserved during evolution, while the precise sequence varies. 25 refs., 5 figs., 3 tabs.

  16. Measurement of branching rates and search for CP violation in decays B0 {yields} {rho} {pi}, {rho} K; Mesure des rapports d'embranchement et recherche de la violation de CP dans les modes B{sup 0}{yields}rhopi, rhoK

    Energy Technology Data Exchange (ETDEWEB)

    Laplace, S

    2003-04-01

    The BABAR experiment, at the PEP-II collider at SLAC, has been studying since 1999 CP violation in the B meson system. After the precise measurement of sin(2*{beta}) we are now concentrating on measuring the alpha and gamma angles of the unitarity triangle. The work presented in this thesis concerns the measurement of the alpha angle in the B{sub 0} {yields} {rho}{pi} mode. We realized a time-dependant analysis of CP and the measurements of branching ratios concerning B{sub 0} {yields} {rho}{sup +-}{pi}{sup -+} and B{sub 0} {yields} {rho}{sup -}K{sup +} modes. The results obtained on an integrated luminosity of 80.9 fb{sup -1} are the following: B(B{sub 0} {yields} {rho}{sup +-}{pi}{sup -+}) = (22.6 {+-} 1.8 {+-} 2.2) 10{sup -6}, B(B{sub 0} {yields} {rho}{sup -}K{sup +}) (7.3 {+-} 1.3 {+-} 1.3) 10{sup -6}, ACP({rho}{pi}) = -0.18 {+-} 0.08 {+-} 0.03, ACP({rho}K) = -0.28 {+-} 0.17 {+-} 0.08, C({rho}{pi}) -0.36 {+-} 0.18 {+-} 0.04, S({rho}{pi}) = -0.19 {+-} 0.24 {+-} 0.03, {delta}C({rho}{pi}) = 0.28 {+-} 0.19 {+-} 0.04, {delta}S({rho}{pi}) = 0.15 {+-} 0.25 {+-} 0.03. We also measured the branching ratio of B{sub 0} {yields} {rho}{sub 0}{pi}{sub 0} with a significance of 2.7 {sigma}. We therefore put the following upper limit at 90% CL (confidence level): B(B{sub 0} {yields} {rho}{sub 0}{pi}{sub 0}) < 2.7*10{sup -6} at 90% CL. Finally, we built the heart of a complete Dalitz plot analysis of B{sub 0} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup 0}, and estimated the experimental sensibility on alpha. The results obtained on the B{sub 0} {yields} {rho}{pi} modes are interpreted in terms of constraints on the alpha angle with methods using SU(2) and SU(3) symmetries. We also measured the branching ratio of B{sub 0} {yields} {alpha}{sub 0}{pi} using a reduced luminosity, leading to the result: B(B{sub 0} {yields} {alpha}{sub 0}{pi}) = (6.2 +3.0-2.5 {+-} 1.1)*10{sup -6}. Some phenomenological studies have been performed to infer the feasibility of a CP analysis to determine the

  17. Islands, Island Studies, Island Studies Journal

    Directory of Open Access Journals (Sweden)

    Godfrey Baldacchino

    2006-05-01

    Full Text Available Islands are sites of innovative conceptualizations, whether of nature or human enterprise, whether virtual or real. The study of islands on their own terms today enjoys a growing and wide-ranging recognition. This paper celebrates the launch of Island Studies Journal in the context of a long and thrilling tradition of island studies scholarship.

  18. Case Study: Writing a Journal Case Study

    Science.gov (United States)

    Prud'homme-Genereux, Annie

    2016-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue describes incorporating a journal article into the classroom by first converting it into a case study.

  19. Electrophysiology Studies (EPS)

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Electrophysiology Studies (EPS) Updated:Dec 21,2016 What are electrophysiology studies? Electrophysiology studies (EPS) are tests that help doctors ...