Lattice dynamical and thermodynamical properties of ReB2, RuB2, and OsB2 compounds in the ReB2 structure

International Nuclear Information System (INIS)

Deligoz, E.; Colakoglu, K.; Ciftci, Y. O.

2012-01-01

Structural and lattice dynamical properties of ReB 2 , RuB 2 , and OsB 2 in the ReB 2 structure are studied in the framework of density functional theory within the generalized gradient approximation. The present results show that these compounds are dynamically stable for the considered structure. The temperature-dependent behaviors of thermodynamical properties such as internal energy, free energy, entropy, and heat capacity are also presented. The obtained results are in good agreement with the available experimental and theoretical data

2.2.1. Synthesis, spectroscopic characterization and crystal structure of [ReV(O2(pyz4][ReII(NOBr4(pyz] (pyz = pyrazine

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Mario Pacheco, Alicia Cuevas, Javier González-Platas, Carlos Kremer*

2015-03-01

Full Text Available Abstract: A novel Re(V-Re(II nitrosyl complex, [Re(O2(pyz 4][Re(NOBr4(pyz] (pyz = pyrazine was prepared and characterized by X-ray diffraction, elemental analysis, infrared and ultraviolet-visible absorption spectra. This product is obtained in the initial steps of the reaction of (NBu4[Re(NOBr4(EtOH] with pyrazine. Both, the cation and the anion are mononuclear complexes. The Re(V atom in the cation is six-coordinate with four nitrogen atoms from pyrazine ligands, and two oxo ligands. The Re(II anion is also six-coordinate, with four bromide ligands, a linear nitrosyl group and one nitrogen from pyrazine. The spectroscopic studies are discussed and compared with those already reported separately for the cation and the anion. Supporting information: X-Ray (CIF file

Do older adults change their eyewitness reports when re-questioned?

Science.gov (United States)

Henkel, Linda A

2014-05-01

This study examined how older adults responded to different types of pressure to change their responses when questioned a second time about their memory for a crime. After watching a video of a crime and answering questions about remembered details, younger (18-22 years) and older adults (64-91 years) were either given negative feedback about their memory performance, were told that most people their age did poorly on the memory test (stereotype threat), or were simply asked to answer the questions again. This was done regardless of their actual accuracy, and the questions were then repeated. Results showed that both younger and older adults changed significantly more responses following negative feedback and changed more responses on misleading than on nonleading questions. Among older adults, as age increased, accuracy decreased and rate of response change increased. People were moderately confident overall about both their correct and incorrect responses. These results highlight the dangers of repeatedly questioning older witnesses with misleading questions and suggest that the responses that are changed may come to be remembered confidently-regardless of whether they are correct or incorrect.

Electronic structures and properties of the rhenium alkoxy derivatives Re2O3(OMe)6, Re4O6(OMe)12, and ReMoO2(OMe)7

International Nuclear Information System (INIS)

Ermakov, A.I.; Belousov, V.V.; Drobot, D.V.; Shcheglov, P.A.

2006-01-01

The geometrical structures, charge distributions, dipole moments, frequencies of normal vibrations, NMR spectra, and total energies of the chemical bonds for the rhenium alkoxy derivatives Re 2 O 3 (OMe) 6 , Re 4 O 6 (OMe) 12 , and ReMoO 2 (OMe) 7 were calculated by the DFT-B3LYP and Hartree-Fock ab initio methods based on the effective core potential theory (LANL2DZ approximation) and the semiempirical PM3(tm) method. Two optimized structures of Re 2 O 3 (OMe) 6 with close energies were found to substantially differ in geometry, 1 H, 13 C, and 17 O NMR spectra, and dipole moment. Various characteristics of the electronic structures and the trans-effect of the ligands in the compounds under consideration were discussed [ru

Neutron diffraction studies on structural and magnetic properties of RE2NiGe3 (RE=La, Ce)

International Nuclear Information System (INIS)

Kalsi, Deepti; Rayaprol, S.; Siruguri, V.; Peter, Sebastian C.

2014-01-01

We report the crystallographic properties of RE 2 NiGe 3 (RE=La, Ce) synthesized by arc melting. Rietveld refinement on the powder neutron diffraction (ND) data suggest both compounds are isostructural and crystallize in the non-centrosymmetric Er 2 RhSi 3 type structure having hexagonal space group P6 ¯ 2c. In the crystal structure of RE 2 NiGe 3 , two dimensional arrangements of nickel and germanium atoms lead to the formation of hexagonal layers with rare earth atoms sandwiched between them. Magnetic susceptibility measurements performed in low fields exhibit antiferromagnetic ordering in cerium compound around (T o =) 3.2 K. Neutron diffraction measurements at 2.8 K (i.e., at T2 NiGe 3 and Ce 2 NiGe 3 crystallize in the Er 2 RhSi 3 type. Magnetic susceptibility show antiferromagnetic ordering for Ce 2 NiGe 3 at 3.2 K and neutron diffraction confirms the absence of long range ordering. - Highlights: RE 2 NiGe 3 (RE=La, Ce) crystallize in the ordered superstructure of the AlB 2 type. Magnetic susceptibility measurements exhibit antiferromagnetic ordering in Ce 2 NiGe 3 . Structure and magnetism of RE 2 NiGe 3 (RE=La, Ce) are studied by neutron diffraction

What Children Learn from Questioning

Science.gov (United States)

Harris, Paul

2015-01-01

Research shows that young children ask a multitude of why and how questions. And when they do, they're not simply trying to get adult attention; instead, they're actively seeking information. In this article, Paul Harris describes the findings of a number of research analyses based on extensive transcripts of children's natural speech. Some of the…

Experimental determination of the hydrothermal solubility of ReS2 and the Re–ReO2 buffer assemblage and transport of rhenium under supercritical conditions

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Wood Scott A

2002-01-01

Full Text Available To understand the aqueous species important for transport of rhenium under supercritical conditions, we conducted a series of solubility experiments on the Re–ReO2 buffer assemblage and ReS2. In these experiments, pH was buffered by the K–feldspar–muscovite–quartz assemblage; in sulfur-free systems was buffered by the Re–ReO2 assemblage; and and in sulfur-containing systems were buffered by the magnetite–pyrite–pyrrhotite assemblage. Our experimental studies indicate that the species ReCl40 is dominant at 400°C in slightly acidic to near-neutral, and chloride-rich (total chloride concentrations ranging from 0.5 to 1.0 M environments, and ReCl3+ may predominate at 500°C in a solution with total chloride concentrations ranging from 0.5 to 1.5 M. The results also demonstrate that the solubility of ReS2 is about two orders of magnitude less than that of ReO2. This finding not only suggests that ReS2 (or a ReS2 component in molybdenite is the solubility-controlling phase in sulfur-containing, reducing environments but also implies that a mixing process involving an oxidized, rhenium-containing solution and a solution with reduced sulfur is one of the most effective mechanisms for deposition of rhenium. In analogy with Re, TcS2 may be the stable Tc-bearing phase in deep geological repositories of radioactive wastes.

Calculation and evaluation of the activation cross sections for 187Re(n,2n)186m,gRe reactions

International Nuclear Information System (INIS)

Huang Xiaolong; Lu Hanlin; Zhou Chunmei

1998-01-01

The activation cross sections for 187 Re(n,2n) 186m,g Re reactions are calculated using UNF code. The calculations are in good agreement with the re-evaluated measured data. Finally the excitation function for 187 Re(n,2n) 186m,g Re reactions are evaluated and recommended based on present calculations and evaluated decay data

(ReTranslating as Re-membering

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Julie Tarif

2016-07-01

Full Text Available This paper explores how (retranslation – interlingual and intersemiotic – can be perceived as a way of both remembering the literary legacy of other cultures but also as a way of re-membering/re-generating the body of literature(s of the importing culture. It focuses on what is called “a classic” and anchors its reflexion in polysystem theory and in the metaphorical vision of literary works as an organic living body. To do so, it concentrates on the British literary classic Oliver Twist and its translations and adaptations into French. The article addresses the following questions: What is to be remembered of certain works? Why, how and by whom are those works remembered?

Refinement of the Al-rich part of the Al–Cu–Re phase diagram and atomic model of the ternary Al{sub 6.2}Cu{sub 2}Re phase

Energy Technology Data Exchange (ETDEWEB)

Samuha, S. [Department of Materials Engineering, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel); NRCN, P.O. Box 9001, Beer Sheva 84190 (Israel); Grushko, B. [MaTecK, Jülich D 52428 (Germany); PGI-5, Forschungszentrum Jülich, Jülich D 52425 (Germany); Meshi, L., E-mail: Louisa@bgu.ac.il [Department of Materials Engineering, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel); Ilse Katz Institute for Nanoscale Science & Technology, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel)

2016-06-15

Partial isothermal sections at 800, 650 and 590 °C were constructed for an Al-rich compositional range of Al–Cu–Re. The maximal solubility of Cu in the Al{sub 11}Re{sub 4}, h-Al{sub 4}Re and l-Al{sub 4}Re phases was found to be ∼6, 4.5, and 2.3 at% respectively, while the solubility of Re in the Al–Cu θ, η{sub 1} and ε{sub 2} phases was below 0.5 at%. Below 740 °C, a ternary hexagonal phase (P6{sub 3}, a = 1.1029 and c = 1.2746 nm) is formed in a small compositional range close to Al{sub 65}Cu{sub 25}Re{sub 10}. Its structural model was deduced by direct methods applied on the precession electron diffraction tomography data. - Highlights: • Al–Cu–Re was studied at 540–1030 °C up to 25 at% Re and 60 at% Cu. • Al{sub 11}Re{sub 4}, h-Al{sub 4}Re and l-Al{sub 4}Re dissolve 6, 4.5 and 2.3 at% Cu, respectively. • Earlier reported ternary compound Al{sub 8}CuRe was not confirmed. • Earlier reported ternary compound Al{sub 7}Cu{sub 2}Re is probably Al{sub 6.2}Cu{sub 2}Re. • Crystal structure of hexagonal Al{sub 6.2}Cu{sub 2}Re was solved.

Influence of annealing temperature on structural and optical properties of SiO{sub 2}:RE{sub 2}O{sub 3} [RE = Y, Gd] powder

Energy Technology Data Exchange (ETDEWEB)

Ahlawat, Rachna, E-mail: rachnaahlawat2003@yahoo.com

2015-07-25

Highlights: • Sol–gel process is used to obtain spherical nanocrystallites of SiO{sub 2}:RE{sub 2}O{sub 3} [RE = Y, Gd] powder. • Effect of four steps annealing is studied on micro strain, nanocrystallite size and dislocation density. • Optical properties are examined by absorption spectra and PL. • SiO{sub 2}:RE{sub 2}O{sub 3} [RE = Y, Gd] binary oxides are promising materials for high temperature structural applications. - Abstract: SiO{sub 2}:RE{sub 2}O{sub 3} [RE = Y, Gd] powder were prepared by wet chemical technique and the prepared binary oxides annealed at 500 °C and 900 °C. The crystalline structure, phase transformation, and surface morphologies of as-prepared and annealed samples were investigated by XRD and TEM. The normal transmission was measured using FTIR spectroscopy. Optical properties have been studied with UV–Vis spectroscopy and PL study. XRD results shows that the as prepared samples of SiO{sub 2}:RE{sub 2}O{sub 3} [RE = Y, Gd] powder has mixed phases of RE(NO{sub 3}){sub 3} and Si(OH){sub 3}. However, cubic rare earth oxide phase alone is found for annealed samples. The strain values are calculated from W–H plot for annealed samples. TEM micrograph shows that the samples are composed of individual spherical nanocrystallites at 500 °C and aggregated nanocrystallites at 900 °C. From the UV–Vis spectra, it is found that the position of the absorption peak is shifted toward the higher wavelength side when annealing temperature is increased. In the PL spectra, the broad emission bands are observed between 570–600 nm and the presence of O–Si–O (silica) and metal oxide is confirmed by FTIR spectra.

Seismic re-evaluation process in Medzamor-2 NPP

International Nuclear Information System (INIS)

Zadoyan, P.

2000-01-01

Seismic re-evaluation process for Medzamor-2 NPP describes the following topics: program implementation status; re-evaluation program structure; regulatory procedure and review plan; current tasks and practice; and regulatory assessment and research programs

[ReF₆]^2-

DEFF Research Database (Denmark)

Pedersen, Kasper Steen; Sigrist, Marc; Sørensen, Mikkel Agerbæk

2014-01-01

studied including the slow relaxation of the magnetization observed below ca. 4 K. This slow dynamic is preserved for the one-dimensional coordination polymer [Zn(viz)4(ReF 6)]1 (2, viz=1-vinylimidazole), demonstrating the irrelevance of low symmetry for such magnetization dynamics in systems with easy......-plane-type anisotropy. The ability of fluoride to mediate significant exchange interactions is exemplified by the isostructural [Ni(viz)4(ReF6)]1 (3) analogue in which the ferromagnetic NiII-ReIV interaction (+10.8 cm-1) dwarfs the coupling present in related cyanide-bridged systems. These results reveal [ReF6...

Intricate Resonant Raman Response in Anisotropic ReS2.

Science.gov (United States)

McCreary, Amber; Simpson, Jeffrey R; Wang, Yuanxi; Rhodes, Daniel; Fujisawa, Kazunori; Balicas, Luis; Dubey, Madan; Crespi, Vincent H; Terrones, Mauricio; Hight Walker, Angela R

2017-10-11

The strong in-plane anisotropy of rhenium disulfide (ReS 2 ) offers an additional physical parameter that can be tuned for advanced applications such as logic circuits, thin-film polarizers, and polarization-sensitive photodetectors. ReS 2 also presents advantages for optoelectronics, as it is both a direct-gap semiconductor for few-layer thicknesses (unlike MoS 2 or WS 2 ) and stable in air (unlike black phosphorus). Raman spectroscopy is one of the most powerful characterization techniques to nondestructively and sensitively probe the fundamental photophysics of a 2D material. Here, we perform a thorough study of the resonant Raman response of the 18 first-order phonons in ReS 2 at various layer thicknesses and crystal orientations. Remarkably, we discover that, as opposed to a general increase in intensity of all of the Raman modes at excitonic transitions, each of the 18 modes behave differently relative to each other as a function of laser excitation, layer thickness, and orientation in a manner that highlights the importance of electron-phonon coupling in ReS 2 . In addition, we correct an unrecognized error in the calculation of the optical interference enhancement of the Raman signal of transition metal dichalcogenides on SiO 2 /Si substrates that has propagated through various reports. For ReS 2 , this correction is critical to properly assessing the resonant Raman behavior. We also implemented a perturbation approach to calculate frequency-dependent Raman intensities based on first-principles and demonstrate that, despite the neglect of excitonic effects, useful trends in the Raman intensities of monolayer and bulk ReS 2 at different laser energies can be accurately captured. Finally, the phonon dispersion calculated from first-principles is used to address the possible origins of unexplained peaks observed in the Raman spectra, such as infrared-active modes, defects, and second-order processes.

Reactions of the dirhenium(II) complexes Re2X4(dppm)2 (X = Cl, Br; dppm = Ph2PCH2PPh2) with isocyanides. 5. Mixed carbonyl-isocyanide and carbonyl-isocyanide-nitrile complexes of stoichiometry (Re2Cl3(dppm)2(CO)(CNR)(L))PF6 (R = t-Bu, xyl (Xylyl); L = t-BuNC, xylNC, MeCN, EtCN). Structural characterization of the cation (Cl2(CO)Re(μ-dppm)2ReCl (CN-t-Bu)2)+

International Nuclear Information System (INIS)

Fanwick, P.E.; Price, A.C.; Walton, R.A.

1988-01-01

Several dirhenium (II) species that contain mixed sets of carbonyl, isocyanide, and/or nitrile ligands have been prepared from the reactions between Re 2 Cl 4 (dppm) 2 (CO)(CNR) (dppm = Ph 2 PCHPPh 2 ; R = t-Bu, xyl (xylyl)), and the appropriate ligands in the presence of TlPF 6 . The crystal structures of these compounds are reported. The terminally-bound ligand noted in the complexes (Re 2 Cl 3 (dppm) 2 (CO)(CN-t-Bu) 2 )PF 6 and (Re 2 CL 3 (dppm) 2 (CO)(CN-t-Bu)(CNxyl))PF 6 indicates structures that have not been previously reported. Complexes in which there are mixed sets of carbonyl, isocyanide, and nitrile ligands, viz. (Re 2 Cl 3 (dppm) 2 (CO)(CNR)(CNR'))PF 6 are also reported. 20 refs., 1 fig., 5 tabs

The social question revisited

DEFF Research Database (Denmark)

Kenneth, Petersson; Olsson, Ulf; Krejsler, John B.

2015-01-01

The focus of this chapter is the re-installation of the social question as a historical practice. The purpose is to investigate how historic figures return and are applied in contemporary political discourses, more precisely in the context of education, education policy and teacher education...

Re-Presenting Slavery: Underserved Questions in Museum Collections

Science.gov (United States)

Levenson, Cyra

2014-01-01

This article looks at the notion of what, not who, is underserved in museum education. The importance of looking through, in, and from objects in order to uncover underserved questions and themes is vital. A willingness to consider new ways to approach collections and display is necessary to have a dialogue with our audiences about how museums can…

Le retour de la question foncière dans l’aménagement des stations touristiques alpines en Suisse

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Christophe Clivaz

2010-09-01

Full Text Available Cette contribution montre dans quelle mesure les enjeux et les problèmes actuels en matière de gestion foncière et immobilière dans les stations touristiques des Alpes suisses découlent pour une part importante des incohérences du régime fédéral de l’aménagement du territoire mis en place à la fin des années 1970, régime fondé sur le zonage et excluant quasiment tout instrument foncier, notamment le prélèvement de la plus-value. Dans ces conditions très favorables aux propriétaires fonciers, qui voient par ailleurs la garantie de la propriété foncière encore renforcée par son inscription dans la Constitution fédérale à la fin des années 1960, les « coalitions de croissances » structurant le pouvoir local dans de nombreuses communes touristiques ont généralement produit des zones à bâtir surdimensionnées (et souvent mal situées qui ont favorisé le développement de l’industrie de la résidence secondaire au détriment de l’immobilier de rente. Face à l’impuissance de la planification et du zonage à limiter ces tendances dont les effets négatifs pour le développement touristique commencent sérieusement à se faire sentir à partir des années 1990, l’on assiste depuis quelques années à la réémergence de la question foncière dans les discussions concernant l’aménagement des stations touristiques, notamment au travers de la mise en œuvre d’instruments fonciers et immobiliers, tels que quotas, contingentements, moratoires ou taxes, intervenant de manière beaucoup plus directe que le seul zonage sur les propriétaires fonciers et immobiliers, modalités d’intervention initialement écartées de la politique d’aménagement du territoire.This contribution demonstrates how the issues and current problems regarding real estate management in Swiss Alpine tourist resorts emerge, for an important part, from the inconsistencies of the Federal land management system set in place at the end of

Large-Area CVD-Grown Sub-2 V ReS2 Transistors and Logic Gates.

Science.gov (United States)

Dathbun, Ajjiporn; Kim, Youngchan; Kim, Seongchan; Yoo, Youngjae; Kang, Moon Sung; Lee, Changgu; Cho, Jeong Ho

2017-05-10

We demonstrated the fabrication of large-area ReS 2 transistors and logic gates composed of a chemical vapor deposition (CVD)-grown multilayer ReS 2 semiconductor channel and graphene electrodes. Single-layer graphene was used as the source/drain and coplanar gate electrodes. An ion gel with an ultrahigh capacitance effectively gated the ReS 2 channel at a low voltage, below 2 V, through a coplanar gate. The contact resistance of the ion gel-gated ReS 2 transistors with graphene electrodes decreased dramatically compared with the SiO 2 -devices prepared with Cr electrodes. The resulting transistors exhibited good device performances, including a maximum electron mobility of 0.9 cm 2 /(V s) and an on/off current ratio exceeding 10 4 . NMOS logic devices, such as NOT, NAND, and NOR gates, were assembled using the resulting transistors as a proof of concept demonstration of the applicability of the devices to complex logic circuits. The large-area synthesis of ReS 2 semiconductors and graphene electrodes and their applications in logic devices open up new opportunities for realizing future flexible electronics based on 2D nanomaterials.

Design and assembly of ternary Pt/Re/SnO2 NPs by controlling the zeta potential of individual Pt, Re, and SnO2 NPs

Science.gov (United States)

Drzymała, Elżbieta; Gruzeł, Grzegorz; Pajor-Świerzy, Anna; Depciuch, Joanna; Socha, Robert; Kowal, Andrzej; Warszyński, Piotr; Parlinska-Wojtan, Magdalena

2018-05-01

In this study Pt, Re, and SnO2 nanoparticles (NPs) were combined in a controlled manner into binary and ternary combinations for a possible application for ethanol oxidation. For this purpose, zeta potentials as a function of the pH of the individual NPs solutions were measured. In order to successfully combine the NPs into Pt/SnO2 and Re/SnO2 NPs, the solutions were mixed together at a pH guaranteeing opposite zeta potentials of the metal and oxide NPs. The individually synthesized NPs and their binary/ternary combinations were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning transmission electron microscopy (STEM) combined with energy dispersive X-ray spectroscopy (EDS) analysis. FTIR and XPS spectroscopy showed that the individually synthesized Pt and Re NPs are metallic and the Sn component was oxidized to SnO2. STEM showed that all NPs are well crystallized and the sizes of the Pt, Re, and SnO2 NPs were 2.2, 1.0, and 3.4 nm, respectively. Moreover, EDS analysis confirmed the successful formation of binary Pt/SnO2 and Re/SnO2 NP, as well as ternary Pt/Re/SnO2 NP combinations. This study shows that by controlling the zeta potential of individual metal and oxide NPs, it is possible to assemble them into binary and ternary combinations. [Figure not available: see fulltext.

Thermochemical Properties of the Complexes RE(HSal)3·2H2O (RE=La, Ce, Pr, Nd, Sm)

Institute of Scientific and Technical Information of China (English)

无

2006-01-01

Five solid rare earth salicylate complexes were synthesized by low hydrated lathanide chloride and salicylic acid. The complexes in this experiment were identified as the general formula RE(Hsal)3·2H2O(RE=La, Ce, Pr, Nd, Sm) by elemental analysis and EDTA volumetric analysis. IR spectra of the complexes show that carboxyl of salicylic acid coordinates to RE3+ ions. Electrochemical behaviors of the complexes on the glass-carbon electrode were researched with cyclic voltammetry (CV). It is indicated that the electrochemical process of the complexes is a one-electron redox process and the electrochemical reversibility of complexes is less than that of the lanthanide chlorides. The constant-volume combustion energies of complexes, ΔcU, were determined with a precise rotating-bomb calorimeter at 298.15 K. Their standard molar enthalpies of combustion, ΔcHθm, and standard molar enthalpies of formation, ΔfHθm, were calculated.

Selective removal of Cs and Re by precipitation in a Na2CO3-H2O2 solution

International Nuclear Information System (INIS)

Eil-Hee Lee; Jae-Gwan Lim; Dong-Yong Chung; Han-Beom Yang; Kwang-Wook Kim

2010-01-01

The removal of Cs and Re (as a surrogate for Tc) by selective precipitation from the simulated fission products which were co-dissolved with uranium during the oxidative dissolution of spent fuel in a Na 2 CO 3 -H 2 O 2 solution was investigated in this study. The precipitations of Cs and Re were examined by introducing sodium tetraphenylborate (NaTPB) and tetraphenylohosponium chloride (TPPCl), respectively. The precipitation of Cs by NaTPB and that of Re by TPPCl each took place within 5 min, and an increase in temperature up to 50 deg C and a stirring speed up to 1000 rpm hardly affected their precipitation rates. The most important factor in the precipitation with NaTPB and TPPCl was found to be a pH of the solution after precipitation. Since Mo tends to co-precipitate with Cs or Re at a lower pH, an effective precipitation with NaTPB and TPPCl was done at pH of above 9 without the co-precipitation of Mo. More than 99% of Cs and Re were precipitated when the initial concentration ratio of NaTPB to Cs was above 1 and when that of TPPCl to Re was above 1. The precipitation of Cs and Re was never affected by the concentration of Na 2 CO 3 and H 2 O 2 , even though they were raised up to 1.5 and 1.0 M, respectively. Precipitation yields of Cs and Re in a Na 2 CO 3 -H 2 O 2 solution were found to be dependent on the concentration ratios of [NaTBP]/[Cs] and [TPPCl]/[Re]. (author)

Energetics of stepwise disordering transformation in pyrochlores, RE2Ti2O7 (RE = Y, Gd and Dy)

International Nuclear Information System (INIS)

Hayun, Shmuel; Tran, Tien B.; Lian, Jie; Fuentes, Antonio F.; Navrotsky, Alexandra

2012-01-01

Graphical abstract: The transformation from disordered to more order state in the pyrochlore system go through multiple energetics steps; the cation sublattice rearrangement is control by the diffusion of the cations while the anion sublattice display an irreversible transformation from a disordered to a higher-ordered state via diffusionless transformation. - Abstract: The capacity to incorporate actinide cations makes pyrochlore titanates first-choice phases in titanate-based waste form ceramics. Despite broad interest in the pyrochlore order–disorder transformation due to the cumulative effects of 238 U, 235 U and 232 Th radioactive decay and their daughter products, only limited thermodynamic data, mainly based on simulations of ion-beam irradiation experiments, have been reported. In this work, for the first time, heavily disordered pyrochlores, RE 2 Ti 2 O 7 (RE = Y, Gd and Dy), from mechanical milling of their constituent oxides, were thermochemically investigated. Two types of thermal events were identified using high-temperature differential scanning calorimetry and correlated to the structural disorder in the cation and anion sublattices. Moreover, the excess formation energy measured by oxide melt solution calorimetry shows that the smaller the ionic radius of the RE, the easier it is to remove damage domains.

Electronic and optoelectronic device applications based on ReS2

Science.gov (United States)

Liu, Erfu; Long, Mingsheng; Wang, Yaojia; Pan, Yiming; Ho, Chinghwa; Wang, Baigeng; Miao, Feng

Rhenium disulfide (ReS2) is a unique semiconducting TMD with distorted 1T structure and weak interlayer coupling. We have previously investigated its in-plane anisotropic property and electronic applications on FET and digital inverters. In this talk, we will present high responsivity phototransistors based on few-layer ReS2. Depending on the back gate voltage, source drain bias and incident optical light intensity, the maximum attainable photoresponsivity can reach as high as 88,600 A W-1, which is one of the highest value among individual two-dimensional materials with similar device structures. Such high photoresponsivity is attributed to the increased light absorption as well as the gain enhancement due to the existence of trap states in the few-layer ReS2 flakes. The existence of trap states is proved by temperature dependent transport measurements. It further enables the detection of weak signals. Our studies underscore ReS2 as a promising material for future electronic and sensitive optoelectronic applications.

The oxidation of ReCl_5 with oleum: synthesis and crystal structure of Re_2O_4Cl_4(SO_4)

International Nuclear Information System (INIS)

Betke, Ulf; Wickleder, Mathias S.

2012-01-01

The reaction of ReCl_5 and fuming sulfuric acid (25 % SO_3) in a sealed glass tube at 200 C led to red, needle shaped single crystals of Re_2O_4Cl_4(SO_4) (monoclinic, C2/c, a = 1501.8(2) pm, b = 1545.9(2) pm, c = 945.18(8) pm, β = 98.761(9) , Z = 8). In the crystal structure the [ReO_2] moieties are linked by [SO_4]"2"- tetrahedra to chains along the [101] direction. Each sulfate ion connects four rhenium atoms, additional two chloride ions complete the octahedral coordination sphere of each rhenium atom according to "1_∞[ReO_2_/_1Cl_2_/_1(SO_4)_2_/_4]. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Preparation of cyclotron-produced {sup 186}Re and comparison with reactor-produced {sup 186}Re and generator-produced {sup 188}Re for the labeling of bombesin

Energy Technology Data Exchange (ETDEWEB)

Moustapha, Moustapha E. [Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211 (United States); University of Missouri Research Reactor (MURR), University of Missouri-Columbia, Columbia, MO 65211 (United States); Ehrhardt, Gary J. [Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211 (United States); University of Missouri Research Reactor (MURR), University of Missouri-Columbia, Columbia, MO 65211 (United States); Smith, Charles J. [Department of Radiology, University of Missouri-Columbia, Columbia, MO 65211 (United States); University of Missouri Research Reactor (MURR), University of Missouri-Columbia, Columbia, MO 65211 (United States); Research Services, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201 (United States); Szajek, Lawrence P. [Positron Emission Tomography Department, National Institutes of Health, Bethesda, MD 20892-1180 (United States); Eckelman, William C. [Positron Emission Tomography Department, National Institutes of Health, Bethesda, MD 20892-1180 (United States); Jurisson, Silvia S. [Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211 (United States)]. E-mail: jurissons@missouri.edu

2006-01-15

-expressing cells. This study showed that the N{sub 3}S-5-Ava-BBN(7-14)NH{sub 2} could be labeled with {sup 186,188}Re following the preconjugation, postmetallation approach. The {sup 186,188}Re{sup V}O-N{sub 3}S-5-Ava-BBN(7-14)NH{sub 2} complexes were found to form stable complexes following the reduction of perrhenate (Re{sup VII}O{sub 4} {sup -}) with stannous chloride at room temperature, as verified by HPLC and stability studies. The radiolabeling yield was found to be >90%. The HPLC chromatograms of {sup 186,188}Re-N{sub 3}S-5-Ava-BBN(7-14)NH{sub 2} complexes revealed two peaks for each conjugate, reflecting the presence of syn- and anti-isomers, which were resolvable by HPLC but re-isomerized on separation. The biodistribution studies showed that the compounds were excreted through the renal and hepatobiliary systems and demonstrated receptor-specific uptake with an average pancreas accumulation of 8.15% ID/g at 1 h postinjection. Administration of cold BBN effectively blocked pancreatic uptake and further reflects the high specificity this conjugate has for the GRP receptors. At low levels of radioactivity, radiolysis effects were not observed. Scale-up may or may not elicit this effect, particularly for the higher energy {beta} emitter {sup 188}Re. The biodistribution studies demonstrated that the CA and NCA {sup 186,188}Re conjugates behaved similarly, raising the question of whether NCA {sup 186,188}Re is necessary for specific tumor receptor targeting.

Ternary rhombohedral Laves phases RE_2Rh_3Ga (RE = Y, La-Nd, Sm, Gd-Er)

International Nuclear Information System (INIS)

Seidel, Stefan; Benndorf, Christopher; Heletta, Lukas; Poettgen, Rainer; Eckert, Hellmut; Sao Paulo Univ., Sao Carlos

2017-01-01

The ordered Laves phases RE_2Rh_3Ga (RE=Y, La-Nd, Sm, Gd-Er) were synthesized by arc-melting of the elements and subsequent annealing. The samples were characterized by powder X-ray diffraction (XRD). They crystallize with the rhombohedral Mg_2Ni_3Si type structure, space group R3m. Three structures were refined from single crystal X-ray diffractometer data: a=557.1(1), c=1183.1(2), wR2=0.0591, 159 F"2 values, 10 variables for Y_2Rh_3Ga, a=562.5(2), c=1194.4(2) pm, wR2=0.0519, 206 F"2 values, 11 variables for Ce_2Rh_3Ga and a=556.7(2), c=1184.1(3) pm, wR2=0.0396, 176 F"2 values, 11 variables for Tb_2Rh_3Ga. The Rh_3Ga tetrahedra are condensed via common corners and the large cavities left by the network are filled by the rare earth atoms. The RE_2Rh_3Ga Laves phases crystallize with a translationengleiche subgroup of the cubic RERh_2 Laves phases with MgCu_2 type. Magnetic susceptibility measurements reveal Pauli paramagnetism for Y_2Rh_3Ga and La_2Rh_3Ga. Ce_2Rh_3Ga shows intermediate cerium valence while all other RE_2Rh_3Ga phases are Curie-Weiss paramagnets which order magnetically at low temperatures. The "8"9Y and "7"1Ga solid state nuclear magnetic resonance (NMR) spectra of the diamagnetic representative Y_2Rh_3Ga show well-defined single resonances in agreement with an ordered bulk phase. In comparison to the binary Laves phase YRh_2 a strongly increased "8"9Y resonance frequency is observed owing to a higher s-electron spin density at the "8"9Y nuclei as proven by density of states (DOS) calculations.

Impact of hydrogen absorption on crystal structure and magnetic properties of RE{sub 2}T{sub 2}X compounds

Energy Technology Data Exchange (ETDEWEB)

Mašková, S., E-mail: maskova@mag.mff.cuni.cz [Department of Condensed Matter Physics, Charles University, Prague 2 (Czech Republic); Kolomiets, A. [Department of Condensed Matter Physics, Charles University, Prague 2 (Czech Republic); Department of Physics, Lviv Polytechnic National University, Lviv (Ukraine); Havela, L. [Department of Condensed Matter Physics, Charles University, Prague 2 (Czech Republic); Andreev, A.V. [Institute of Physics, AVCR, Prague 8 (Czech Republic); Svoboda, P. [Department of Condensed Matter Physics, Charles University, Prague 2 (Czech Republic)

2015-10-05

Highlights: • RE{sub 2}Pd{sub 2}In(Sn) compounds absorb, depending on RE, different amounts of hydrogen. • Compounds with the light rare earths become amorphous upon the hydrogenation. • Compounds with the heavy rare earths preserve the original tetragonal structure. • Magnetic ordering temperatures of RE{sub 2}Pd{sub 2}In compounds are reduced by the hydrogenation. - Abstract: RE{sub 2}Pd{sub 2}In, RE{sub 2}Pd{sub 2}Sn compounds (RE = rare earth) absorb, depending on the rare earth (RE) element, different amounts of hydrogen. The parent compounds RE{sub 2}Pd{sub 2}In show the linear decrease of both lattice parameters and the unit cell volume with the increasing atomic number of RE, attributed to the lanthanide contraction. All the compounds absorb at least 2 H/f.u.; the tetragonal structure is merely expanded. The expansion is anisotropic (Δc/c > Δa/a), and for RE = Tb, Dy, Ho, and Er the lattice even contracts along the a-axis (Δa/a < 0), whereas Δc/c still weakly increases. A higher H concentration can be achieved in the compounds with light rare earths (La, Nd, both for In and Sn), which then become amorphous. The magnetic ordering temperatures of all studied RE{sub 2}Pd{sub 2}In compounds are dramatically reduced by the hydrogenation, typically to the temperature range below 1.8 K.

IDC Re-Engineering Phase 2 Architecture Document.

Energy Technology Data Exchange (ETDEWEB)

Burns, John F.

2015-12-01

This document contains a description of the system architecture for the IDC Re-Engineering Phase 2 project. This is a draft version that primarily provides background information for understanding delivered Use Case Realizations.

The effect of children on men's and women's chances of re-partnering in a European context

NARCIS (Netherlands)

Ivanova, K.; Kalmijn, M.; Uunk, W.

2013-01-01

This work examines what role children play in the re-partnering process in five European countries (Norway, France, Germany, Romania, and the Russian Federation) by addressing the following research questions: (1) To what extent do men and women differ in their re-partnering chances?; (2) Can gender

Polytypism and unexpected strong interlayer coupling in two-dimensional layered ReS2

Science.gov (United States)

Qiao, Xiao-Fen; Wu, Jiang-Bin; Zhou, Linwei; Qiao, Jingsi; Shi, Wei; Chen, Tao; Zhang, Xin; Zhang, Jun; Ji, Wei; Tan, Ping-Heng

2016-04-01

Anisotropic two-dimensional (2D) van der Waals (vdW) layered materials, with both scientific interest and application potential, offer one more dimension than isotropic 2D materials to tune their physical properties. Various physical properties of 2D multi-layer materials are modulated by varying their stacking orders owing to significant interlayer vdW coupling. Multilayer rhenium disulfide (ReS2), a representative anisotropic 2D material, was expected to be randomly stacked and lack interlayer coupling. Here, we demonstrate two stable stacking orders, namely isotropic-like (IS) and anisotropic-like (AI) N layer (NL, N > 1) ReS2 are revealed by ultralow- and high-frequency Raman spectroscopy, photoluminescence and first-principles density functional theory calculation. Two interlayer shear modes are observed in AI-NL-ReS2 while only one shear mode appears in IS-NL-ReS2, suggesting anisotropic- and isotropic-like stacking orders in IS- and AI-NL-ReS2, respectively. This explicit difference in the observed frequencies identifies an unexpected strong interlayer coupling in IS- and AI-NL-ReS2. Quantitatively, the force constants of them are found to be around 55-90% of those of multilayer MoS2. The revealed strong interlayer coupling and polytypism in multi-layer ReS2 may stimulate future studies on engineering physical properties of other anisotropic 2D materials by stacking orders.Anisotropic two-dimensional (2D) van der Waals (vdW) layered materials, with both scientific interest and application potential, offer one more dimension than isotropic 2D materials to tune their physical properties. Various physical properties of 2D multi-layer materials are modulated by varying their stacking orders owing to significant interlayer vdW coupling. Multilayer rhenium disulfide (ReS2), a representative anisotropic 2D material, was expected to be randomly stacked and lack interlayer coupling. Here, we demonstrate two stable stacking orders, namely isotropic-like (IS) and

Copper(II) perrhenate Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2}: Synthesis from isopropanol and CuReO{sub 4}, structure and properties

Energy Technology Data Exchange (ETDEWEB)

Mikhailova, D., E-mail: d.mikhailova@ifw-dresden.de [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials (IAM), Hermann-von-Helmholtz-Platz 1, D-76434 Eggenstein-Leopoldshafen (Germany); Institute for Complex Materials, IFW Dresden, Helmholtzstrasse 20, D-01069 Dresden (Germany); Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, D-01187 Dresden (Germany); Engel, J.M. [Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Str. 2, D-64287 Darmstadt (Germany); Schmidt, M. [Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, D-01187 Dresden (Germany); Tsirlin, A.A. [National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn (Estonia); Ehrenberg, H. [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials (IAM), Hermann-von-Helmholtz-Platz 1, D-76434 Eggenstein-Leopoldshafen (Germany); Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Str. 2, D-64287 Darmstadt (Germany)

2015-12-15

The crystal structure of Cu{sup +}Re{sup 7+}O{sub 4} is capable of a quasi-reversible incorporation of C{sub 3}H{sub 7}OH molecules. A room-temperature reaction between CuReO{sub 4} and C{sub 3}H{sub 7}OH under oxidizing conditions leads to the formation of a novel metal-organic hybrid compound Cu{sup 2+}(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2}. Upon heating under reducing conditions, this compound transforms back into CuReO{sub 4}, albeit with ReO{sub 2} and metallic Cu as by-products. The crystal structure of Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2} solved from single-crystal X-ray diffraction (Pbca, a=10.005(3) Å, b=7.833(2) Å, and c=19.180(5) Å) reveals layers of corner-sharing CuO{sub 6}-octahedra and ReO{sub 4}-tetrahedra, whereas isopropyl groups are attached to both sides of these layers, thus providing additional connections within the layers through hydrogen bonds. Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2} is paramagnetic down to 4 K because the spatial arrangement of the Cu{sup 2+} half-filled orbitals prevents magnetic superexchange. The paramagnetic effective moment of 2.0(1) μ{sub B} is slightly above the spin-only value and typical for Cu{sup 2+} ions. - Highlights: • Novel Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2} compound has a sequence of inorganic and organic layers. • Hydrogen bonds provide an additional bonding Isopropanol molecules serve as a reducing agent during decomposition. • No direct Cu-O-Re-O-Cu connections via d{sub x2-y2} orbital of Cu{sup 2+} explain paramagnetism. • Hydrogen bonds provide an additional bonding. • Isopropanol molecules serve as a reducing agent during decomposition.

Synthesis, crystal structure, and magnetic properties of novel 2D kagome materials RE{sub 3}Sb{sub 3}Mg{sub 2}O{sub 14} (RE = La, Pr, Sm, Eu, Tb, Ho): Comparison to RE{sub 3}Sb{sub 3}Zn{sub 2}O{sub 14} family

Energy Technology Data Exchange (ETDEWEB)

Sanders, M.B.; Baroudi, K.M.; Krizan, J.W.; Mukadam, O.A.; Cava, R.J. [Department of Chemistry, Princeton University, Princeton, NJ (United States)

2016-10-15

The crystal structures and magnetic properties of RE{sub 3}Sb{sub 3}Mg{sub 2}O{sub 14} (RE = La, Pr, Sm, Eu, Tb, Ho) with a perfect kagome lattice are presented and compared to RE{sub 3}Sb{sub 3}Zn{sub 2}O{sub 14}. Rietveld structure refinements were performed using X-ray diffraction data, indicating that the layered compounds are fully structurally ordered. The compounds crystallize in a rhombohedral supercell of the cubic pyrochlore structure, in the space group R-3m. Magnetic susceptibility measurements show no signs of magnetic ordering above 2 K. The RE{sub 3}Sb{sub 3}Mg{sub 2}O{sub 14} family is similar to that of RE{sub 3}Sb{sub 3}Zn{sub 2}O{sub 14}; however, the series reported here features a fully ordered distribution of cations in both the nonmagnetic antimony and magnetic rare earth kagome lattices. Unlike the offsite disorder that Zn{sup 2+} experiences in RE{sub 3}Sb{sub 3}Zn{sub 2}O{sub 14}, the magnesium sites in RE{sub 3}Sb{sub 3}Mg{sub 2}O{sub 14} are completely ordered. Here we compare the magnetic properties in both series of kagome compounds to determine how significant Zn{sup 2+}'s positional ordering is within this structure type. The compounds reported here appear to be relatively defect-free and are therefore model systems for investigating magnetic frustration on an ideal 2D rare earth kagome lattice. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Ternary gallides RE_4Rh_9Ga_5, RE_5Rh_1_2Ga_7 and RE_7Rh_1_8Ga_1_1 (RE=Y, La-Nd, Sm, Gd, Tb). Intergrowth structures with MgCu_2 and CaCu_5 related slabs

International Nuclear Information System (INIS)

Seidel, Stefan; Rodewald, Ute C.; Poettgen, Rainer; Janka, Oliver

2017-01-01

Fourteen ternary gallides RE_4Rh_9Ga_5, RE_5Rh_1_2Ga_7 and RE_7Rh_1_8Ga_1_1 (RE=Y, La-Nd, Sm, Gd, Tb) were synthesized from the elements by arc-melting, followed by different annealing sequences either in muffle or induction furnaces. The samples were characterized through Guinier powder patterns and the crystal structures of Ce_4Rh_9Ga_5, Ce_5Rh_1_2Ga_7, Ce_7Rh_1_8Ga_1_1, Nd_5Rh_1_0_._4_4_(_4_)Ga_8_._5_6_(_4_), Nd_4Rh_9Ga_5 and Gd_4Rh_9Ga_5 were refined from single crystal X-ray diffractometer data. The new gallides are the n=2, 3 and 5 members of the RE_2_+_n Rh_3_+_3_n Ga_1_+_2_n structure series in the Parthe intergrowth concept. The slabs of these intergrowth structures derive from the cubic Laves phase MgCu_2 (Mg_2Ni_3Si as ternary variant) and CaCu_5 (CeCo_3B_2 as ternary variant). Only the Nd_5Rh_1_0_._4_4_(_4_)Ga_8_._5_6_(_4_) crystal shows Rh/Ga mixing within the Laves type slabs. Magnetic susceptibility measurements reveal Pauli paramagnetism for Y_4Rh_9Ga_5 and Curie-Weiss paramagnetism for Gd_4Rh_9Ga_5 and Tb_4Rh_9Ga_5. Low-temperature data show ferromagnetic ordering at T_C=78.1 (Gd_4Rh_9Ga_5) and 55.8 K (Tb_4Rh_9Ga_5).

Room temperature synthesis of ReS2 through aqueous perrhenate sulfidation

Science.gov (United States)

Borowiec, Joanna; Gillin, William P.; Willis, Maureen A. C.; Boi, Filippo S.; He, Y.; Wen, J. Q.; Wang, S. L.; Schulz, Leander

2018-02-01

In this study, a direct sulfidation reaction of ammonium perrhenate (NH4ReO4) leading to a synthesis of rhenium disulfide (ReS2) is demonstrated. These findings reveal the first example of a simplistic bottom-up approach to the chemical synthesis of crystalline ReS2. The reaction presented here takes place at room temperature, in an ambient and solvent-free environment and without the necessity of a catalyst. The atomic composition and structure of the as-synthesized product were characterized using several analysis techniques including energy dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, x-ray diffraction, transmission electron microscopy, Raman spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The results indicated the formation of a lower symmetry (1Tʹ) ReS2 with a low degree of layer stacking.

Yttrium aluminum garnet (YAG) obtained by rare-earth mixed oxide (RE2O3)

International Nuclear Information System (INIS)

Castro, D.F.; Daguano, J.K.M.F.; Rodrigues Junior, D.; Suzuki, P.A.; Silva, O.M.M.

2010-01-01

In this work, the substitution of commercial Y 2 O 3 by a rare earth mixed oxide, RE 2 O 3 , to form Yttrium aluminum Garnet-Y 3 Al 5 O 12 , was investigated. Al 2 O 3 :Y 2 O 3 and Al 2 O 3 :RE 2 O 3 powder-mixtures, in a molar ratio of 60:40, were milled and subsequently cold uniaxially-pressed. Compacts were sintered at 1000, 1400 or 1600 deg C, for 120 minutes. RE 2 O 3 oxide was characterized by high-resolution synchrotron X-ray diffraction (HRXRD) and compared to Y 2 O 3 . X-ray diffraction pattern of the RE 2 O 3 indicates a true solid solution formation. Rietveld refinement of the sintered YAG and (RE)AG reveled a similar crystal structure to the YAGs obtained by the use of Al 2 O 3 -Y 2 O 3 or Al 2 O 3 -RE 2 O 3 respectively. Microstructural analysis of both, YAG or (RE)AG, revealed similar grain sizes of about 2.5 μm besides mechanical properties, with hardness of 400HV and fracture toughness of 3.8MPa.m1/2. It could be, thus, demonstrated that pure Y 2 O 3 can be substituted by the rare-earth solid solution, RE 2 O 3 , in the formation YAGs, presenting similar microstructural and mechanical properties. (author)

Room temperature synthesis of ReS2 through aqueous perrhenate sulfidation.

Science.gov (United States)

Borowiec, Joanna; Gillin, William P; Willis, Maureen; Boi, Filippo; He, Yi; Wen, Jiqiu; Wang, Shanling; Schulz, Leander

2017-12-29

In this study, a direct sulfidation reaction of ammonium perrhenate (NH₄ReO₄) leading to a synthesis of rhenium disulfide (ReS₂) is demonstrated. These finding reveal the first example of a simplistic bottom-up approach to the chemical synthesis of crystalline ReS₂. The reaction presented here takes place at room temperature, in an ambient and solvent-free environment and without the necessity of a catalyst. The atomic composition and structure of the as-synthesized product were characterized using several analysis techniques including energy dispersive X-ray (EDX) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, thermogravimetric analysis (TGA) and differential scannig calorimetry (DSC). The results indicated the formation of a lower symmetry (1T_d) ReS₂ with a low degree of layer stacking. © 2017 IOP Publishing Ltd.

A study on the electronic and interfacial structures of monolayer ReS2-metal contacts.

Science.gov (United States)

Wang, Jin; Yang, Guofeng; Sun, Rui; Yan, Pengfei; Lu, Yanan; Xue, Junjun; Chen, Guoqing

2017-10-11

In this paper, we perform a systematic and rigorous study to evaluate the Ohmic nature of the top-contact formed by the monolayer ReS 2 (mReS 2 ) and metals (gold, silver, platinum, nickel, titanium, and scandium) by means of first-principles density functional theory calculations. We investigate the potential barrier, charge transfer and atomic orbital overlap at the mReS 2 -metal interface in consideration of van der Waals forces to understand how efficiently carriers could be injected from the metal contact to the mReS 2 channel. ReS 2 is physisorbed on Au and Ag, which leads to little perturbation of its electronic structures and forms a larger Schottky contact and a higher tunnel barrier at the interface. ReS 2 is chemisorbed on Ti and Sc, where the bonding strongly perturbs the electronic structures and is found to be purely Ohmic. The bonding of ReS 2 on Pt and Ni lies between these two extreme cases, demonstrating an intermediate behavior. These findings not only provide an insight into the mReS 2 -metal interfaces but may also prove to be instrumental in the future design of ReS 2 -based devices with good performance.

Structural, hyperfine and Raman properties of RE2FeSbO7 compounds

International Nuclear Information System (INIS)

Berndt, G.; Silva, K.L.; Ivashita, F.F.; Paesano, A.; Blanco, M.C.; Miner, E.V.P.; Carbonio, R.E.; Dantas, S.M.; Ayala, A.P.; Isnard, O.

2015-01-01

Highlights: • We prepared monophasic RE 2 FeSbO 7 pyrochlores. • RE 2 FeSbO 7 compounds were characterized regarding crystallographic, vibrational and hyperfine properties. • We find out that a site disorder takes place for the RE’s of larger ionic radii. • Lattice parameters, Raman bands and quadrupole splittings were shown to depend correlatedly on the RE ionic radius. - Abstract: Pyrochlores of the RE 2 FeSbO 7 type were synthesized by ball-milling followed by annealing in free atmosphere at high temperatures. The samples prepared were characterized by X-ray diffraction, Raman spectroscopy and 57 Fe Mössbauer spectroscopy, at room temperature. The results showed that RE 2 FeSbO 7 compounds have a cubic structure, i.e., Fd-3m (#227) space group, and that a site disorder takes place for the RE’s of larger ionic radii. Lattice parameters, Raman bands and quadrupole splittings were shown to depend correlatedly on the RE ionic radius. This behavior is discussed in terms of the pyrochlore crystallographic structure

Sol–gel synthesis of long-lasting phosphors CdSiO3: Mn2+, RE3+ (RE = Tb, Eu, Nd) and luminescence mechanism research

International Nuclear Information System (INIS)

Qu, Xiaofei; Cao, Lixin; Liu, Wei; Su, Ge; Wang, Pingping; Schultz, Isabel

2012-01-01

Highlights: ► New long-lasting CdSiO 3 : Mn 2+ , RE 3+ (RE = Tb, Eu, Nd) phosphors were synthesized by a sol–gel method. ► The afterglow performance of the CdSiO 3 : Mn 2+ , Eu 3+ phosphor was the best. ► The role of RE 3+ co-doped into the CdSiO 3 : Mn 2+ matrix was discussed in this paper. -- Abstract: Mn 2+ and RE 3+ (RE = Tb, Eu, Nd) co-doped CdSiO 3 orange phosphors were prepared at 1050 °C by a sol–gel method. The phase and crystallinity of the synthesized materials were investigated by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The luminescence characteristics were analyzed using photoluminescence (PL) spectra, afterglow decay curves, long-lasting phosphorescence spectra, and thermoluminescence (TL) spectra. Due to the difference in co-doped rare earth ionic radii, it varied greatly in trap density and trap depth caused by the different defects deriving from RE 3+ ions co-doping into the CdSiO 3 : Mn 2+ host. The afterglow intensity and time for these samples increased as follows: CdSiO 3 : Mn 2+ 0.2%, Nd 3+ 0.8% 3 : Mn 2+ 0.4%, Tb 3+ 0.8% 3 : Mn 2+ 0.4%, Eu 3+ 0.3%. CdSiO 3 : Mn 2+ 0.4%, Eu 3+ 0.3% had the best afterglow properties, which could be due to the proper traps formed by Eu 3+ ions co-doping into the host. The role of RE 3+ co-doped into the CdSiO 3 : Mn 2+ matrix and the possible long-lasting phosphorescence process was also discussed in this paper.

The Analysis of the Primary School Mathematics Exam Questions According to the MATH Taxonomy [İlköğretim Matematik Dersi Sınav Sorularının MATH Taksonomisine Göre Analizi

Directory of Open Access Journals (Sweden)

Berna Aygün

2016-04-01

Full Text Available In this study, the contents and types of elementary 6th, 7th, 8th grades’ mathematics exam questions are analyzed according to groups and categories of the MATH taxonomy. In order to achieve this aim documentary analysis research and Chi-square test are used and the analyses of questions are based on the definitions of groups and categories of the MATH taxonomy. Analyzed questions consist of 939 questions which are collected from mathematics classes of different schools at East Blacksea regions. In all of the questions, 260 are at 6th grade (27.7%, 327 are at 7th grade (34.8%, and 352 are at 8th grade (37.5% mathematics written exam questions. According to the results, two in every three questions used by instructors in math exams are at A3 "Routine use of Procedures" level in which the use of the procedure or algorithm is required to use properly. Most of the questions are from category A which contains routine procedures and basic abilities. in addition to this, there are fewer questions at category B which is required the higher order thinking skill, and scarcely any questions at higher-up thinking level, category C. [Bu çalışmada ilköğretim 6., 7. ve 8. sınıfların matematik dersi sınav sorularının ait olduğu öğrenme alanlarının ve soru türlerinin MATH taksonomi grup ve kategorilerine göre incelenmesi amaçlanmıştır. Bu amaç doğrultusunda çalışmada karma yöntem kullanılmış ve sorular MATH Taksonomi Grup ve Kategorilerine ait açıklamalar temel alınarak doküman incelemesi ve ki-kare testi ile analiz edilmiştir. İncelenen sorular, Doğu Karadeniz bölgesindeki çeşitli okullardaki matematik dersi sınavlarında sorulan toplam 939 sorudan oluşmaktadır. Bu sorulardan 260 tanesi (% 27,7 6. sınıf, 327 tanesi (% 34,8 7. sınıf, 352 tanesi (% 37,5 ise 8. sınıf matematik dersi yazılı sınav sorularıdır. Elde edilen bulgulara göre öğretmenlerin matematik dersi sınavlarında kullandıkları her 3

ReCourse Learning Design Editor 2.0

NARCIS (Netherlands)

Beauvoir, Phillip; Sharples, Paul; Griffiths, Dai; Miao, Yongwu

2009-01-01

ReCourse is an Eclipse Rich Client Platform application. A number of plug-ins are included, enabling users to author QTI compliant tests, link to services, upload to repositories, and publish and populate Units of Learning. New features in version 2.0 include support for IMS LD levels B & C, and a

Field induced 4f5d [Re(salen)]2O3[Dy(hfac)3(H2O)]2 single molecule magnet.

Science.gov (United States)

Pointillart, Fabrice; Bernot, K; Sessoli, R; Gatteschi, D

2010-05-03

The reaction between the mononuclear [ReO(salen)(OMe)] (salen(2-) = N,N'-ethan-1,2-diylbis(salicylidenamine) dianion) and Dy(hfac)(3).2H(2)O (hfac(-) = 1,1,1,5,5,5-hexafluoroacetylacetonate anion) complexes lead to the formation of a compound with the formula {[Re(salen)](2)O(3)[Dy(hfac)(3)(H(2)O)](2)}(CHCl(3))(2)(CH(2)Cl(2))(2) noted (Dy(2)Re(2)). This compound has been characterized by single crystal and powder X-ray diffraction and has been found isostructural to the Y(III) derivative (Y(2)Re(2)) that we previously reported. The cyclic voltammetry demonstrates the redox activity of the system. The characterization of both static and dynamic magnetic properties is reported. Static magnetic data has been analyzed after the cancellation of the crystal field contribution by two different methods. Weak ferromagnetic exchange interactions between the Dy(III) ions are highlighted. The compound Dy(2)Re(2) displays slow relaxation of the magnetization when an external magnetic field is applied. Alternating current susceptibility shows a thermally activated behavior with pre-exponential factors of 7.13 (+/-0.10) x 10(-6) and 5.76 (+/-0.27) x 10(-7) s, and energy barriers of 4.19 (+/-0.02) and 8.52 (+/-0.55) K respectively for low and high temperature regimes.

Completing the series. New coordination networks of composition {sup 3}{sub ∞}[RE{sub 2}(ADC){sub 3}(H{sub 2}O){sub 6}].2H{sub 2}O with RE = Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Y and ADC{sup 2-} = acetylenedicarboxylate ({sup -}O{sub 2}C-C≡C-CO{sub 2}{sup -})

Energy Technology Data Exchange (ETDEWEB)

Gramm, Verena K.; Schuy, Andrea; Ruschewitz, Uwe [Institut fuer Anorganische Chemie, Koeln Univ. (Germany); Suta, Markus; Wickleder, Claudia [Anorganische Chemie, Universitaet Siegen (Germany); Sternemann, Christian [Fakultaet Physik / DELTA, Technische Universitaet Dortmund (Germany)

2018-02-01

The crystal structures of {sup 3}{sub ∞}[RE{sub 2}(ADC){sub 3}(H{sub 2}O){sub 6}].2H{sub 2}O (RE = Pr, Nd, Sm, Eu, Tb, Dy) were solved and refined from X-ray single crystal data. They crystallize in a structure type already known for RE = La, Ce and Gd (P1, no. 2, Z = 2), which is characterized by REO{sub 9} polyhedra forming dimeric units being the nodes of a 3D framework structure linked by ADC{sup 2-} anions ({sup -}O{sub 2}C-C≡C-CO{sub 2}{sup -} = acetylenedicarboxylate). From synchrotron powder diffraction data it was shown that isostructural coordination networks are formed for RE = Ho, Er, Y, whereas for RE = Tm, Yb, Lu a new structure type crystallizing in a highly complex crystal structure with a large orthorhombic unit cell is found. All compounds are obtained by slow evaporation of an aqueous solution containing RE(OAc){sub 3}.xH{sub 2}O and acetylenedicarboxylic acid (H{sub 2}ADC). The coordination networks of composition {sup 3}{sub ∞}[RE{sub 2}(ADC){sub 3}(H{sub 2}O){sub 6}].2H{sub 2}O were thoroughly investigated by thermal analysis and for RE = Eu, Tb, a strong red and green photoluminescence was observed and investigated by means of UV/Vis spectroscopy. (copyright 2018 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Narrowing the gap: from semiconductor to semimetal in the homologous series of rare-earth zinc arsenides RE(2-y)Zn4As4·n(REAs) and Mn-substituted derivatives RE(2-y)Mn(x)Zn(4-x)As4·n(REAs) (RE = La-Nd, Sm, Gd).

Science.gov (United States)

Lin, Xinsong; Tabassum, Danisa; Mar, Arthur

2015-12-14

A homologous series of ternary rare-earth zinc arsenides, prepared by reactions of the elements at 750 °C, has been identified with the formula RE(2-y)Zn4As4·n(REAs) (n = 2, 3, 4) for various RE members. They adopt trigonal structures: RE(4-y)Zn4As6 (RE = La-Nd), space group R3̄m1, Z = 3; RE(5-y)Zn4As7 (RE = Pr, Nd, Sm, Gd), space group P3̄m1, Z = 1; RE(6-y)Zn4As8 (RE = La-Nd, Sm, Gd), space group R3̄m1, Z = 3. The Zn atoms can be partially substituted by Mn atoms, resulting in quaternary derivatives RE(2-y)Mn(x)Zn(4-x)As4·n(REAs). Single-crystal structures were determined for nine ternary and quaternary arsenides RE(2-y)M4As4·n(REAs) (M = Mn, Zn) as representative examples of these series. The structures are built by stacking close-packed nets of As atoms, sometimes in very long sequences, with RE atoms occupying octahedral sites and M atoms occupying tetrahedral sites, resulting in an intergrowth of [REAs] and [M2As2] slabs. The recurring feature of all members of the homologous series is a sandwich of [M2As2]-[REAs]-[M2As2] slabs, while rocksalt-type blocks of [REAs] increase in thickness between these sandwiches with higher n. Similar to the previously known related homologous series REM(2-x)As2·n(REAs) which is deficient in M, this new series RE(2-y)M4As4·n(REAs) exhibits deficiencies in RE to reduce the electron excess that would be present in the fully stoichiometric formulas. Enthalpic and entropic factors are considered to account for the differences in site deficiencies in these two homologous series. Band structure calculations indicate that the semiconducting behaviour of the parent n = 0 member (with CaAl2Si2-type structure) gradually evolves, through a narrowing of the gap between valence and conduction bands, to semimetallic behaviour as the number of [REAs] blocks increases, to the limit of n = ∞ for rocksalt-type REAs.

Radioanalysis of RE enrichment of ion adsorption type RE ores

CERN Document Server

Zhao Shu Quan; Hu He Ping; Li Fu Sheng; Chen Ying Min; LiuShiMing

2002-01-01

Objective: To analyze the radioactivity in Rare Earth (RE) enrichment of ion adsorption type RE ores. Methods: Using HPGe-gamma spectrometer to analyze the activity ratio of gamma radionuclides in kind of samples, using FJ-2603 low background alpha, beta measurement apparatus to measure their total alpha and total beta activities, and using X-ray fluorescence spectrometer to analyze contents of La sub 2 O sub 3 and Y sub 2 O sub 3 , respectively. Results: HPGe gamma spectroscopy and X-ray fluorescence spectroscopy are simple, convenient and non-destructive methods of analyzing radionuclides and La sub 2 O sub 3 , Y sub 2 O sub 3 in RE enrichment of ion adsorption type RE ores, respectively. Conclusion: The basic data were provided for radiation protection and treatment of gas, liquid and solid waste in RE production of ion adsorption type RE ores; method and experience were provided for studying ion adsorption type RE ores

Ternary rhombohedral Laves phases RE{sub 2}Rh{sub 3}Ga (RE = Y, La-Nd, Sm, Gd-Er)

Energy Technology Data Exchange (ETDEWEB)

Seidel, Stefan; Benndorf, Christopher; Heletta, Lukas; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Janka, Oliver [Oldenburg Univ. (Germany). Inst. fuer Chemie; Mausolf, Bernhard [RWTH Aachen (Germany). Inst. fuer Anorganische Chemie; Haarmann, Frank [RWTH Aachen (Germany). Inst. fuer Anorganische Chemie; Max-Planck-Institut fuer Chemische Physik fester Stoffe, Dresden (Germany); Eckert, Hellmut [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; Sao Paulo Univ., Sao Carlos (Brazil). Inst. of Physics

2017-06-01

The ordered Laves phases RE{sub 2}Rh{sub 3}Ga (RE=Y, La-Nd, Sm, Gd-Er) were synthesized by arc-melting of the elements and subsequent annealing. The samples were characterized by powder X-ray diffraction (XRD). They crystallize with the rhombohedral Mg{sub 2}Ni{sub 3}Si type structure, space group R3m. Three structures were refined from single crystal X-ray diffractometer data: a=557.1(1), c=1183.1(2), wR2=0.0591, 159 F{sup 2} values, 10 variables for Y{sub 2}Rh{sub 3}Ga, a=562.5(2), c=1194.4(2) pm, wR2=0.0519, 206 F{sup 2} values, 11 variables for Ce{sub 2}Rh{sub 3}Ga and a=556.7(2), c=1184.1(3) pm, wR2=0.0396, 176 F{sup 2} values, 11 variables for Tb{sub 2}Rh{sub 3}Ga. The Rh{sub 3}Ga tetrahedra are condensed via common corners and the large cavities left by the network are filled by the rare earth atoms. The RE{sub 2}Rh{sub 3}Ga Laves phases crystallize with a translationengleiche subgroup of the cubic RERh{sub 2} Laves phases with MgCu{sub 2} type. Magnetic susceptibility measurements reveal Pauli paramagnetism for Y{sub 2}Rh{sub 3}Ga and La{sub 2}Rh{sub 3}Ga. Ce{sub 2}Rh{sub 3}Ga shows intermediate cerium valence while all other RE{sub 2}Rh{sub 3}Ga phases are Curie-Weiss paramagnets which order magnetically at low temperatures. The {sup 89}Y and {sup 71}Ga solid state nuclear magnetic resonance (NMR) spectra of the diamagnetic representative Y{sub 2}Rh{sub 3}Ga show well-defined single resonances in agreement with an ordered bulk phase. In comparison to the binary Laves phase YRh{sub 2} a strongly increased {sup 89}Y resonance frequency is observed owing to a higher s-electron spin density at the {sup 89}Y nuclei as proven by density of states (DOS) calculations.

Indides RE{sub 3}T{sub 2}In{sub 4} (RE = Y, Gd-Tm, Lu; T = Ni, Ru, Rh) with a ZrNiAl superstructure

Energy Technology Data Exchange (ETDEWEB)

Heying, Birgit; Niehaus, Oliver; Rodewald, Ute C.; Poettgen, Rainer [Univ. Muenster (Germany). Inst. fuer Anorganische und Analytische Chemie

2016-07-01

Three series of rare earth-transition metal-indides RE{sub 3}T{sub 2}In{sub 4} (RE=Y, Gd-Tm, Lu; T=Ni, Ru, Rh) were synthesized from arc-melted RE{sub 3}T{sub 2} precursor compounds and indium tear shot in sealed niobium ampoules using different annealing sequences. The new indides crystallize with the hexagonal Lu{sub 3}Co{sub 2}In{sub 4}-type structure, space group P anti 6. All samples were characterized on the basis of Guinier powder patterns and six structures were refined from single crystal X-ray diffractometer data. The RE{sub 3}T{sub 2}In{sub 4} structures are derived from the ZrNiAl type through RE/In ordering, paralleled by a symmetry reduction from P anti 62m to P anti 6. This induces twinning for some of the investigated crystals. The main crystal chemical motifs of the RE{sub 3}T{sub 2}In{sub 4} structures are trigonal prisms of rare earth, respectively indium atoms that are filled by the transition metals.

Rhenium Re

International Nuclear Information System (INIS)

Busev, A.I.; Tiptsova, V.G.; Ivanov, V.M.

1978-01-01

The basic methods for determining rhenium in various objects are presented. The gravimetric determination of rhenium is based on a quantitative precipitation of ReO 4 - ions with tetraphenylarsonium chloride. The determination is not hindered by tungstates and molybdates. The potentiometric determination of rhenium in alloys (>=0.5% Re) is based on perrhenate ion reduction to Re(4) with the titrated solution of the Cr(2) salt. Re(7) is titrated in a hot sulfuric acid solution in the presence of KJ. The relative error of the method is 1 to 3%. The photometric determination of rhenium is performed by the rhodamide method in molybdenum-and tungsten-containing alloys and catalytically, in rocks, after it has been separated in the form of sulfide. The extraction-photometric determination of rhenium is carried out with the aid of methyl violet (analysis of a stock with a high content of Mo, W, Ta, Nb, Ti ahd Zr) and thio-oxine (the determination of Re is hindered by Au, Pt, Pd, Ru, Os, Rh, Ir). Also described are methods for differential-spectrophotometric determination of Re with the aid of thiocarbamide, as well as with the aid of dimethylglyoxime in the presence of SnCl 2 in an acid medium when Re is determined in its alloys with niobium and hafnium. It takes 2 hours to analyze the Hf-Re alloy and 3 hours to analyze the Nb-Re alloy, the standard deviation being 0.005 at 30-50% Re and 0.027 to 0.019 at 10-50% Re

Ternary rare-earth bismuthides RE5SiBi2 and RE5GeBi2 (RE=La-Nd, Gd-Er): Stabilization of the β-Yb5Sb3-type structure through tetrel substitution

International Nuclear Information System (INIS)

Barry, Stephen D.; Tkachuk, Andriy V.; Bie, Haiying; Blanchard, Peter E.R.; Mar, Arthur

2011-01-01

Ternary bismuthides RE 5 TtBi 2 containing rare-earth (RE=La-Nd, Gd-Er) and tetrel (Tt=Si, Ge) atoms have been prepared by arc-melting of the elements followed by annealing at 800 o C. They adopt the β-Yb 5 Sb 3 -type structure (Pearson symbol oP32, space group Pnma, Z=4), as revealed through analysis by single-crystal X-ray diffraction on Ce 5 Si 0.869(4) Bi 2.131(4) and powder X-ray diffraction on Ce 5 GeBi 2 . Cell parameters for the entire series lie in the ranges of a=12.8-11.8 A, b=9.6-9.0 A, and c=8.4-7.9 A. Solid solubility in Ce 5 Si x Bi 3-x and Pr 5 Si x Bi 3-x (approximately 0.9≤x≤1.2, depending on the RE member) is much more limited compared to the antimonides, consistent with a highly ordered structure in which the two possible anion sites are essentially segregated into a smaller one occupied by Tt atoms (CN7) and a larger one occupied by Bi atoms (CN9). Band structure calculations on La 5 SiBi 2 confirm the importance of La-La bonding interactions near the Fermi level. X-ray photoelectron spectra support the presence of partially anionic Bi atoms, as indicated by a small negative binding energy shift relative to elemental Bi. The Ce and Pr members undergo magnetic transitions at low temperatures, possibly involving ferromagnetic interactions, that are strongly influenced by the nature of the Tt atom. -- Graphical Abstract: Tetrel (Si or Ge) and Bi atoms are arranged in an ordered manner in the β-Yb 5 Sb 3 -type structure adopted by RE 5 TtBi 2 . Display Omitted

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.

Unraveling the Raman Enhancement Mechanism on 1T'-Phase ReS2 Nanosheets.

Science.gov (United States)

Miao, Peng; Qin, Jing-Kai; Shen, Yunfeng; Su, Huimin; Dai, Junfeng; Song, Bo; Du, Yunchen; Sun, Mengtao; Zhang, Wei; Wang, Hsing-Lin; Xu, Cheng-Yan; Xu, Ping

2018-04-01

2D transition metal dichalcogenides materials are explored as potential surface-enhanced Raman spectroscopy substrates. Herein, a systematic study of the Raman enhancement mechanism on distorted 1T (1T') rhenium disulfide (ReS 2 ) nanosheets is demonstrated. Combined Raman and photoluminescence studies with the introduction of an Al 2 O 3 dielectric layer unambiguously reveal that Raman enhancement on ReS 2 materials is from a charge transfer process rather than from an energy transfer process, and Raman enhancement is inversely proportional while the photoluminescence quenching effect is proportional to the layer number (thickness) of ReS 2 nanosheets. On monolayer ReS 2 film, a strong resonance-enhanced Raman scattering effect dependent on the laser excitation energy is detected, and a detection limit as low as 10 -9 m can be reached from the studied dye molecules such as rhodamine 6G and methylene blue. Such a high enhancement factor achieved through enhanced charge interaction between target molecule and substrate suggests that with careful consideration of the layer-number-dependent feature and excitation-energy-related resonance effect, ReS 2 is a promising Raman enhancement platform for sensing applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of the ES-2re Dummy in Biofidelity, Component, and Full Vehicle Crash Tests.

Science.gov (United States)

Sutterfield, Aleta; Pecoraro, Katie; Rouhana, Stephen W; Xu, Lan; Abramczyk, Joe; Berliner, Jeff; Irwin, Annette; Jensen, Jack; Mertz, Harold J; Nusholtz, Guy; Pietsch, Hollie; Scherer, Risa; Tylko, Suzanne

2005-11-01

This technical paper presents the results from tests conducted with the ES-2re, a version of the ES-2 side impact dummy that was modified by the National Highway Traffic Safety Administration (NHTSA) to improve its performance in crash tests. Through the series of biofidelity tests conducted on the ES-2re, described in International Standards Organization (ISO) Technical Report (TR)9790 (1999), the OSRP observed a final overall biofidelity ranking of 4.1 for the ES-2re, which corresponds to an ISO classification of "marginal." The biofidelity of the ES-2re is compared to that of the ES-2 and the WorldSID. Repeatability was also evaluated on the ES-2re based on the biofidelity test data. Additional pendulum tests were performed to assess the response of the dummy in oblique loading conditions, and results indicate that oblique loading from the front leads to significantly reduced rib deflections. To evaluate inconsistencies observed in the response of the ES-2, the OSRP analyzed the shoulder biofidelity via additional sled and drop tests. Due to the shoulder design of the ES-2 and ES-2re, the dummies appear to have significant sensitivity to initial conditions, potentially increasing variability in full vehicle tests. Finally, the responses of the ES-2re in full vehicle tests are compared to those of the ES-2 and the WorldSID.

High temperature properties of rare-earth tungstates RE{sub 2}W{sub 2}O{sub 9}

Energy Technology Data Exchange (ETDEWEB)

Marrero-López, D., E-mail: damarre@uma.es [Dpto. de Física Aplicada I, Universidad de Málaga, 29071-Málaga (Spain); Canales-Vázquez, J. [Renewable Energy Research Institute, University of Castilla-La Mancha, 02071-Albacete (Spain); Ruiz-Morales, J.C.; Núñez, P. [Dpto. de Química, U.D. Química Inorgánica, Universidad de la Laguna, 38206-Tenerife (Spain)

2015-02-15

Highlights: • RE{sub 2}W{sub 2}O{sub 9} (RE = Nd, Pr, Sm, Eu and Gd) are prepared by freeze-drying precursor. • The samples crystallize in the monoclinic s.g. P2{sub 1}/c. • A first order phase transition was detected between 330 and 590 °C. • These materials exhibit low ionic conductivity of 10{sup -5} S cm{sup -1} at 800 °C. - Abstract: RE{sub 2}W{sub 2}O{sub 9} (RE = Ce, Nd, Pr, Sm, Eu, Gd and Tb) compounds have been prepared by a freeze-drying precursor method in order to explore their high temperature thermal properties by different techniques. Samples with Nd, Pr, Sm, Eu and Gd crystallize in the same monoclinic structure with space group P2{sub 1}/c. The thermal, X-ray diffraction, and electrical analysis reveal the existence of a reversible first order phase transition, which is accompanied by a sudden decrease of the unit cell volume and conductivity. A large thermal hysteresis of about 250 °C is also observed during the heating and cooling processes. These materials exhibit low electrical conductivity of the order of 10{sup -5} S cm{sup -1} at 800 °C.

Rancière, Marx and Claudette Colvin: Time, Knowledge, Memory and Strategy of Politics

Directory of Open Access Journals (Sweden)

Anders Fjeld

2015-01-01

Full Text Available How does Jacques Rancière construct a democratic approach to politics through his critique of Marxism as a “metapolitics”? I will develop the hypothesis that Rancière reconfigures the Marxist political subject by disconnecting it from its metapolitics, searching to think it rather in terms of improper excess, untimeliness and the force to forget. I will then define how Rancière rethinks the concepts of time and knowledge, opening questions left in suspense in his thought on memory, strategy and power – questions that might belong to a more experimental and existential register. I will develop these questions through a study on the black movement in 1955-56 in Montgomery, Alabama.

Isotope effect on superconductivity and Raman phonons of Pyrochlore Cd2Re2O7

Science.gov (United States)

Razavi, F. S.; Hajialamdari, M.; Reedyk, M.; Kremer, R. K.

2018-06-01

Cd2Re2O7 is the only α-Pyrochlore exhibiting superconductivity with a transition temperature (Tc) of ∼ 1 K. In this study, we present the effect of oxygen isotope (18O) as well as combined 18O and cadmium isotope (116Cd) substitution on the superconductivity and Raman scattering spectrum of Cd2Re2O7. The change of Tc and the energy gap Δ(T) are reported using various techniques including point contact spectroscopy. The shift in Raman phonon frequencies upon isotope substitution will be compared with measurement of the isotope effect on the superconducting transition temperature.

DMPD: Cytokines, PGE2 and endotoxic fever: a re-assessment. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 15967158 Cytokines, PGE2 and endotoxic fever: a re-assessment. Blatteis CM, Li S, L... (.svg) (.html) (.csml) Show Cytokines, PGE2 and endotoxic fever: a re-assessment. PubmedID 15967158 Title C...ytokines, PGE2 and endotoxic fever: a re-assessment. Authors Blatteis CM, Li S, L

Hierarchical architecture of ReS_2/rGO composites with enhanced electrochemical properties for lithium-ion batteries

International Nuclear Information System (INIS)

Qi, Fei; Chen, Yuanfu; Zheng, Binjie; He, Jiarui; Li, Qian; Wang, Xinqiang; Lin, Jie; Zhou, Jinhao; Yu, Bo; Li, Pingjian; Zhang, Wanli

2017-01-01

Highlights: • The ReS_2/rGO composites have been synthesized by a facile one-pot method. • The ReS_2/rGO composites exhibit hierarchical architecture. • The ReS_2/rGO composites deliver better electrochemical performances than ReS_2. • The enhanced performance is due to porous and conductive structure of ReS_2/rGO. - Abstract: Rhenium disulfide (ReS_2), a two-dimensional (2D) semiconductor, has attracted more and more attention due to its unique anisotropic electronic, optical, mechanical properties. However, the facile synthesis and electrochemical property of ReS_2 and its composite are still necessary to be researched. In this study, for the first time, the ReS_2/reduced graphene oxide (rGO) composites have been synthesized through a facile and one-pot hydrothermal method. The ReS_2/rGO composites exhibit a hierarchical, interconnected, and porous architecture constructed by nanosheets. As anode for lithium-ion batteries, the as-synthesized ReS_2/rGO composites deliver a large initial capacity of 918 mAh g"−"1 at 0.2 C. In addition, the ReS_2/rGO composites exhibit much better electrochemical cycling stability and rate capability than that of bare ReS_2. The significant enhancement in electrochemical property can be attributed to its unique architecture constructed by nanosheets and porous structure, which can allow for easy electrolyte infiltration, efficient electron transfer, and ionic diffusion. Furthermore, the graphene with high electronic conductivity can provide good conductive passageways. The facile synthesis approach can be extended to prepare other 2D transition metal dichalcogenides semiconductors for energy storage and catalytic application.

Structural order parameter in the pyrochlore superconductor Cd sub 2 Re sub 2 O sub 7

CERN Document Server

Sergienko, I A

2003-01-01

It is shown that both structural phase transitions in Cd sub 2 Re sub 2 O sub 7 , which occur at T sub s sub 1 = 200 K and T sub s sub 2 = 120 K, are due to an instability of the Re tetrahedral network with respect to the same doubly degenerate long-wavelength phonon mode. The primary structural order parameter transforms according to the irreducible representation E sub u of the point group O sub h. We argue that the transition at T sub s sub 1 may be of the second order, in accordance with experimental data. We obtain the phase diagram in the space of phenomenological parameters and propose a thermodynamic path that Cd sub 2 Re sub 2 O sub 7 follows upon cooling. Coupling of the itinerant electronic system and localized spin states in pyrochlores and spinels to atomic displacements are discussed. (author)

Invention/Re-invention

OpenAIRE

Mera, M.

2009-01-01

This article examines the relationship between texts that are re-invented for different media and/or contexts including: film remakes, prequels and sequels, video games that become films and vice versa, internet mashups, and television series that move across geographical borders. The article points to significant sources in this emerging field and presents some of the challenges that arise in relation to its study. In particular questions of originality, fidelity, repetition and difference a...

Query2Question: Translating Visualization Interaction into Natural Language.

Science.gov (United States)

Nafari, Maryam; Weaver, Chris

2015-06-01

Richly interactive visualization tools are increasingly popular for data exploration and analysis in a wide variety of domains. Existing systems and techniques for recording provenance of interaction focus either on comprehensive automated recording of low-level interaction events or on idiosyncratic manual transcription of high-level analysis activities. In this paper, we present the architecture and translation design of a query-to-question (Q2Q) system that automatically records user interactions and presents them semantically using natural language (written English). Q2Q takes advantage of domain knowledge and uses natural language generation (NLG) techniques to translate and transcribe a progression of interactive visualization states into a visual log of styled text that complements and effectively extends the functionality of visualization tools. We present Q2Q as a means to support a cross-examination process in which questions rather than interactions are the focus of analytic reasoning and action. We describe the architecture and implementation of the Q2Q system, discuss key design factors and variations that effect question generation, and present several visualizations that incorporate Q2Q for analysis in a variety of knowledge domains.

Crystal Structure, Spectroscopic Investigations, and Physical Properties of the Ternary Intermetallic REPt2Al3 (RE = Y, Dy–Tm and RE2Pt3Al4 Representatives (RE = Tm, Lu

Directory of Open Access Journals (Sweden)

Fabian Eustermann

2018-04-01

Full Text Available The REPt2Al3 compounds of the late rare-earth metals (RE = Y, Dy–Tm were found to crystallize isostructural. Single-crystal X-ray investigations of YPt2Al3 revealed an orthorhombic unit cell (a = 1080.73(6, b = 1871.96(9, c = 413.04(2 pm, wR2 = 0.0780, 942 F2 values, 46 variables with space group Cmmm (oC48; q2pji2hedb. A comparison with the Pearson database indicated that YPt2Al3 forms a new structure type, in which the Pt and Al atoms form a [Pt2Al3]δ− polyanion and the Y atoms reside in the cavities within the framework. Via a group-subgroup scheme, the relationship between the PrNi2Al3-type structure and the new YPt2Al3-type structure was illustrated. The compounds with RE = Dy–Tm were characterized by powder X-ray diffraction experiments. While YPt2Al3 is a Pauli-paramagnet, the other REPt2Al3 (RE = Dy–Tm compounds exhibit paramagnetic behavior, which is in line with the rare-earth atoms being in the trivalent oxidation state. DyPt2Al3 and TmPt2Al3 exhibit ferromagnetic ordering at TC = 10.8(1 and 4.7(1 K and HoPt2Al3 antiferromagnetic ordering at TN = 5.5(1 K, respectively. Attempts to synthesize the isostructural lutetium compound resulted in the formation of Lu2Pt3Al4 (Ce2Ir3Sb4-type, Pnma, a = 1343.4(2, b = 416.41(8, c = 1141.1(2 pm, which could also be realized with thulium. The structure was refined from single-crystal data (wR2 = 0.0940, 1605 F2 values, 56 variables. Again, a polyanion with bonding Pt–Al interactions was found, and the two distinct Lu atoms were residing in the cavities of the [Pt3Al4]δ– framework. X-ray photoelectron spectroscopy (XPS measurements were conducted to examine the electron transfer from the rare-earth atoms onto the polyanionic framework.

Chemical effects of nuclear transformations in mixed crystals. 7. Chemical effects of the 35Cl(n,γ)36Cl nuclear reaction in K2ReCl6-K2ReBr6 mixed crystals

International Nuclear Information System (INIS)

Mueller, H.; Diefallah, E.H.M.; Martin, S.

1981-01-01

The solid-state reactions occurring during the moderation of recoiling 36 Cl, produced by the (n,γ) reaction, have been studied in K 2 ReCl 6 -K 2 ReBr 6 mixed crystals. The main reaction products are Re 36 ClCl 5 2- , Re 36 ClBr 5 2- , and 36 Cl - , but the more intimately mixed species Re 36 ClCl/sub n/Br/sub 5-n/ 2- (n = 1, 2, 3, 4) are found in significant amounts. The production of the different recoil-labeled species can be explained by elementary impact models: 6% of the recoils do not leave their original lattice site (primary retetion); between 6% and 23%, dependent upon the mixed-crystal composition, appear as interstitials; 31 to 48% give rise to direct displacement reactions of one halide ligand; and 40% produce larger disruption by substitution of at least two halide ligands. The results have been compared with Roessler's 38 Cl recoil experiments

Full elastic tensor of a crystal of the superhard compound ReB{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Levine, J.B. [Department of Chemistry and Biochemistry and California NanoSystems Institute, University of California, Los Angeles, CA 90095-1569 (United States); Betts, J.B. [National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Garrett, J.D. [Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario, L8S 4M1 (Canada); Guo, S.Q. [Composites Group, National Institute for Materials Science, Tsukuba 3050047 (Japan); Eng, J.T. [Department of Chemistry and Biochemistry and California NanoSystems Institute, University of California, Los Angeles, CA 90095-1569 (United States); Migliori, A., E-mail: migliori@cybermesa.com [National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Kaner, R.B., E-mail: kaner@chem.ucla.edu [Department of Chemistry and Biochemistry and California NanoSystems Institute, University of California, Los Angeles, CA 90095-1569 (United States)] [Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095-1595 (United States)

2010-03-15

The search for superhard materials, driven by their widespread use in industrial applications, highlights one of the most difficult problems in the field of materials science: the accurate characterization of a material's intrinsic physical properties. This paper reports on the full elastic tensor of two polycrystalline isotropic specimens and one specimen of ReB{sub 2} consisting of highly oriented grains. The high-monocrystal bulk modulus value extracted from the grain-oriented specimen, measured by resonant ultrasound spectroscopy, validates the ultra-incompressibility of ReB{sub 2}. An observed hardness of 40 GPa and a Debye temperature of 731 K were calculated for the ReB{sub 2} crystal, confirming its superhard and super-stiff properties. All the measured moduli of the ReB{sub 2} grain-oriented crystal exceed the comparable ones for the polycrystal by amounts that cannot be explained by averaging over direction, which may reveal why recent measurements reported on ReB{sub 2} containing excess boron yield values that are not as hard or incompressible as the crystal.

Investigation of the transport properties and compositions of the Ca{sub 2}RE{sub 7}Pn{sub 5}O{sub 5} series (RE=Pr, Sm, Gd, Dy; Pn=Sb, Bi)

Energy Technology Data Exchange (ETDEWEB)

Forbes, Scott [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada); Yuan, Fang [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada); Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Kosuda, Kosuke; Kolodiazhnyi, Taras [Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Mozharivskyj, Yurij, E-mail: mozhar@mcmaster.ca [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada)

2016-10-15

The Ca{sub 2}RE{sub 7}Pn{sub 5}O{sub 5} phases (RE=Pr, Sm, Gd, Dy; Pn=Sb, Bi) were successfully prepared from high temperature reactions at 1225–1300 °C. These phases maintain the same structure types as the parent RE{sub 9}Pn{sub 5}O{sub 5} phases, except for a Ca/RE mixing. The study and preparation of these phases was motivated by the desire to shift the metallic type properties of the parent RE{sub 9}Pn{sub 5}O{sub 5} phases to a level more suitable for thermoelectric applications. Electrical resistivity measurements performed on pure, bulk samples indicated all phases to be narrow band gap semiconductors or semimetals, supporting the charge balanced electron count of the Ca{sub 2}RE{sub 7}Pn{sub 5}O{sub 5} composition. Unfortunately, all samples are too electrically resistive for any potential usage as thermoelectrics. Electronic band structure calculations performed on idealized RE{sub 9}Pn{sub 5}O{sub 5} structures revealed the presence of a pseudogap at the Fermi level, which is consistent with the observed electrical resistivity and Seebeck coefficient behavior. - Graphical abstract: Ca substitution in RE{sub 9}Pn{sub 5}O{sub 5} leads to charge-balanced Ca{sub 2}RE{sub 7}Pn{sub 5}O{sub 5} phases with semiconducting or semimetallic properties. - Highlights: • The RE{sub 9}Pn{sub 5}O{sub 5} structure may be stabilized with calcium substitution in the form of Ca{sub 2}RE{sub 7}Pn{sub 5}O{sub 5}. • The Ca{sub 2}RE{sub 7}Pn{sub 5}O{sub 5} phases maintain the parent P 4/n structure, albeit with Ca/RE mixing. • The Ca{sub 2}RE{sub 7}Sb{sub 5}O{sub 5} phases behave as semiconductors while Ca{sub 2}RE{sub 7}Bi{sub 5}O{sub 5} are semimetals with electron-electron correlations. • Electronic structure calculations yield a semimetal-like density of states for both Ca{sub 2}RE{sub 7}Sb{sub 5}O{sub 5} and Ca{sub 2}RE{sub 7}Bi{sub 5}O{sub 5}.

Magnetic, electrical and structural properties of the Re-doped ruthenocuprate Ru{sub 1−x}Re{sub x}Sr{sub 2}GdCu{sub 2}O{sub y}

Energy Technology Data Exchange (ETDEWEB)

Corredor, L.T. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Programa de Pós-Graduação em Ciências de Materiais-CCEN, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Grupo de Física de Nuevos Materiales, Departamento de Física, Universidad Nacional de Colombia, Bogotá D.C. (Colombia); Albino Aguiar, J. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Programa de Pós-Graduação em Ciências de Materiais-CCEN, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Landínez Téllez, D.A. [Grupo de Física de Nuevos Materiales, Departamento de Física, Universidad Nacional de Colombia, Bogotá D.C. (Colombia); Pureur, P.; Mesquita, F. [Instituto de Física, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, RS (Brazil); Roa-Rojas, J. [Grupo de Física de Nuevos Materiales, Departamento de Física, Universidad Nacional de Colombia, Bogotá D.C. (Colombia)

2015-06-15

Highlights: • We investigated the effect of the dilution of magnetic Ru sub-lattice of RuSr{sub 2}GdCu{sub 2}O{sub 8}. • We synthesized the doped compound Rui{sub x}Re{sub x}Sr{sub 2}GdCu{sub 2}O{sub y}, for 3%, 6%, 9% and 12% Re. • Re would affect the electron coupling: just 3 and 6% samples were superconductor. • Superconductivity emergence strongly affects magnetic properties of 3 and 6% samples. • A weak ferromagnetic component is consistent with a globally antiferromagnetic system. - Abstract: Despite the discovery of new superconductors classes, high-Tc oxides continue to be a current topic, because of their complex phase diagrams and doping-dependant effects (allowing one to investigate the interaction between orbitals), as well as structural properties such as lattice distortion and charge ordering, among many others. Ruthenocuprates are magnetic superconductors in which the magnetic transition temperature is much higher than the critical superconducting temperature, making them unique compounds. With the aim of investigating the dilution of the magnetic Ru sub-lattice, we proposed the synthesis of the Ru{sub 1−x}Re{sub x}Sr{sub 2}GdCu{sub 2}O{sub y} ruthenocuprate-type family, adapting the known two-step process (double perovskite + CuO) by directly doping the double perovskite, thus obtaining the perovskite compound Sr{sub 2}GdRu{sub 1−x}Re{sub x}O{sub y}, which represents a new synthesis process to the best of our knowledge. Our samples were structurally characterized through X-ray diffraction, and the patterns were analysed via Rietveld refinement. A complete magnetic characterization as a function of temperature and applied field, as well as transport measurements were carried out. We discuss our results in the light of the two-lattice model for ruthenocuprates, and a relation between RuO{sub 2} (magnetic) and CuO{sub 2} (superconductor) sub-lattices can clearly be observed.

Chemical Vapor Deposition Growth of Degenerate p-Type Mo-Doped ReS2 Films and Their Homojunction.

Science.gov (United States)

Qin, Jing-Kai; Shao, Wen-Zhu; Xu, Cheng-Yan; Li, Yang; Ren, Dan-Dan; Song, Xiao-Guo; Zhen, Liang

2017-05-10

Substitutional doping of transition metal dichalcogenide two-dimensional materials has proven to be effective in tuning their intrinsic properties, such as band gap, transport characteristics, and magnetism. In this study, we realized substitutional doping of monolayer rhenium disulfide (ReS 2 ) with Mo via chemical vapor deposition. Scanning transmission electron microscopy demonstrated that Mo atoms are successfully doped into ReS 2 by substitutionally replacing Re atoms in the lattice. Electrical measurements revealed the degenerate p-type semiconductor behavior of Mo-doped ReS 2 field effect transistors, in agreement with density functional theory calculations. The p-n diode device based on a doped ReS 2 and ReS 2 homojunction exhibited gate-tunable current rectification behaviors, and the maximum rectification ratio could reach up to 150 at V d = -2/+2 V. The successful synthesis of p-type ReS 2 in this study could largely promote its application in novel electronic and optoelectronic devices.

Re criticality assessment following reactor core damage in Fukushima unit 2

International Nuclear Information System (INIS)

Jeong, Hae Sun; Song, Jin Ho; Park, Chang Je; Ha, Kwang Soon; Song, Yong Mann; Ryu, Eun Hyun

2012-01-01

Following the severe core damage accident at the Fukushima nuclear power plants (NPPs), many researchers have studied a possible Re criticality caused by core melting or corium. However, no one can accurately examine the internal conditions of the reactor vessel, and thus there have been different opinions from some organizations depending on their assumption and analysis methods. If there is a potential Re criticality in the reactor vessel, some counter plans for the accident management should be established to prevent and mitigate re criticality, and to return the plant to a safe and stable state. In this study, the criticality level following a severe core damage accident was first analyzed using the MCNPX 2.6.0 code. Based on this result, practical strategies in terms of accident management were obtained by charging soluble boron (H 3B O 3) into re flooded water

Cubic Re6+ (5d1) Double Perovskites, Ba2MgReO6, Ba2ZnReO6, and Ba2Y2/3ReO6: Magnetism, Heat Capacity, μSR, and Neutron Scattering Studies and Comparison with Theory.

Science.gov (United States)

Marjerrison, Casey A; Thompson, Corey M; Sala, Gabrielle; Maharaj, Dalini D; Kermarrec, Edwin; Cai, Yipeng; Hallas, Alannah M; Wilson, Murray N; Munsie, Timothy J S; Granroth, Garrett E; Flacau, Roxana; Greedan, John E; Gaulin, Bruce D; Luke, Graeme M

2016-10-04

Double perovskites (DP) of the general formula Ba 2 MReO 6 , where M = Mg, Zn, and Y 2/3 , all based on Re 6+ (5d 1 , t 2g 1 ), were synthesized and studied using magnetization, heat capacity, muon spin relaxation, and neutron-scattering techniques. All are cubic, Fm3̅m, at ambient temperature to within the resolution of the X-ray and neutron diffraction data, although the muon data suggest the possibility of a local distortion for M = Mg. The M = Mg DP is a ferromagnet, T c = 18 K, with a saturation moment ∼0.3 bohr magnetons at 3 K. There are two anomalies in the heat capacity: a sharp feature at 18 K and a broad maximum centered near 33 K. The total entropy loss below 45 K is 9.68 e.u., which approaches R ln 4 (11.52 e.u.) supporting a j = 3/2 ground state. The unit cell constants of Ba 2 MgReO 6 and the isostructural, isoelectronic analogue, Ba 2 LiOsO 6 , differ by only 0.1%, yet the latter is an anti-ferromagnet. The M = Zn DP also appears to be a ferromagnet, T c = 11 K, μ sat (Re) = 0.1 μ B . In this case the heat capacity shows a somewhat broad peak near 10 K and a broader maximum at ∼33 K, behavior that can be traced to a smaller particle size, ∼30 nm, for this sample. For both M = Mg and Zn, the low-temperature magnetic heat capacity follows a T 3/2 behavior, consistent with a ferromagnetic spin wave. An attempt to attribute the broad 33 K heat capacity anomalies to a splitting of the j = 3/2 state by a crystal distortion is not supported by inelastic neutron scattering, which shows no transition at the expected energy of ∼7 meV nor any transition up to 100 meV. However, the results for the two ferromagnets are compared to the theory of Chen, Pereira, and Balents, and the computed heat capacity predicts the two maxima observed experimentally. The M = Y 2/3 DP, with a significantly larger cell constant (3%) than the ferromagnets, shows predominantly anti-ferromagnetic correlations, and the ground state is complex with a spin frozen component T

The oxidation of ReCl{sub 5} with oleum: synthesis and crystal structure of Re{sub 2}O{sub 4}Cl{sub 4}(SO{sub 4})

Energy Technology Data Exchange (ETDEWEB)

Betke, Ulf; Wickleder, Mathias S. [Carl von Ossietzky University of Oldenburg, Institute of Pure and Applied Chemistry (Germany)

2012-01-15

The reaction of ReCl{sub 5} and fuming sulfuric acid (25 % SO{sub 3}) in a sealed glass tube at 200 C led to red, needle shaped single crystals of Re{sub 2}O{sub 4}Cl{sub 4}(SO{sub 4}) (monoclinic, C2/c, a = 1501.8(2) pm, b = 1545.9(2) pm, c = 945.18(8) pm, β = 98.761(9) , Z = 8). In the crystal structure the [ReO{sub 2}] moieties are linked by [SO{sub 4}]{sup 2-} tetrahedra to chains along the [101] direction. Each sulfate ion connects four rhenium atoms, additional two chloride ions complete the octahedral coordination sphere of each rhenium atom according to {sup 1}{sub ∞}[ReO{sub 2/1}Cl{sub 2/1}(SO{sub 4}){sub 2/4}]. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Taylor dispersion in premixed combustion: Questions from turbulent combustion answered for laminar flames

Science.gov (United States)

Daou, Joel; Pearce, Philip; Al-Malki, Faisal

2018-02-01

We present a study of Taylor dispersion in premixed combustion and use it to clarify fundamental issues related to flame propagation in a flow field. In particular, simple analytical formulas are derived for variable density laminar flames with arbitrary Lewis number Le providing clear answers to important questions arising in turbulent combustion, when these questions are posed for the case of one-scale laminar parallel flows. Exploiting, in the context of a laminar Poiseuille flow model, a thick flame distinguished asymptotic limit for which the flow amplitude is large with the Reynolds number Re fixed, three main contributions are made. First, a link is established between Taylor dispersion [G. Taylor, Proc. R. Soc. London Ser. A 219, 186 (1953), 10.1098/rspa.1953.0139] and Damköhler's second hypothesis [G. Damköhler, Ber. Bunsen. Phys. Chem. 46, 601 (1940)] by describing analytically the enhancement of the effective propagation speed UT due to small flow scales. More precisely, it is shown that Damköhler's hypothesis is only partially correct for one-scale parallel laminar flows. Specifically, while the increase in UT due to the flow is shown to be directly associated with the increase in the effective diffusivity as suggested by Damköhler, our results imply that UT˜Re (for Re≫1 ) rather than UT˜√{Re} , as implied by Damköhler's hypothesis. Second, it is demonstrated analytically and confirmed numerically that, when UT is plotted versus the flow amplitude for fixed values of Re, the curve levels off to a constant value depending on Re. We may refer to this effect as the laminar bending effect as it mimics a similar bending effect known in turbulent combustion. Third, somewhat surprising implications associated with the dependence of UT and of the effective Lewis number Leeff on the flow are reported. For example, Leeff is found to vary from Le to Le-1 as Re varies from small to large values. Also, UT is found to be a monotonically increasing function

Low-Frequency Noise in Layered ReS2 Field Effect Transistors on HfO2 and Its Application for pH Sensing.

Science.gov (United States)

Liao, Wugang; Wei, Wei; Tong, Yu; Chim, Wai Kin; Zhu, Chunxiang

2018-02-28

Layered rhenium disulfide (ReS 2 ) field effect transistors (FETs), with thickness ranging from few to dozens of layers, are demonstrated on 20 nm thick HfO 2 /Si substrates. A small threshold voltage of -0.25 V, high on/off current ratio of up to ∼10 7 , small subthreshold swing of 116 mV/dec, and electron carrier mobility of 6.02 cm 2 /V·s are obtained for the two-layer ReS 2 FETs. Low-frequency noise characteristics in ReS 2 FETs are analyzed for the first time, and it is found that the carrier number fluctuation mechanism well describes the flicker (1/f) noise of ReS 2 FETs with different thicknesses. pH sensing using a two-layer ReS 2 FET with HfO 2 as a sensing oxide is then demonstrated with a voltage sensitivity of 54.8 mV/pH and a current sensitivity of 126. The noise characteristics of the ReS 2 FET-based pH sensors are also examined, and a corresponding detection limit of 0.0132 pH is obtained. Our studies suggest the high potential of ReS 2 for future low-power nanoelectronics and biosensor applications.

MAG2GABA-biocytin synthesized with new intermediates for radiolabelling 99mTc and 188Re

International Nuclear Information System (INIS)

Ahn, S.H.; Choi, T.H.; Choi, C.W.; Yang, S.D.; Woo, K.S.; Chung, W.S.; Lim, S.M.

2001-01-01

188 Re from 188 W- 188 Re generator, is recently introduced in therapeutic nuclear medicine and made it possible to use whenever needed. We synthesized MAG 2 GABA-Biocytin (MGB), labelled with 188 Re for pretargeted radioimmunotherapy and evaluated biological behavior of 188 Re-MGB. N-hydroxysuccinimidyl ester of S-benzoyl mercaptoacetyldiglycine (NHS-MAG 2 ) was synthesized first, reacted with aminobutyric acid(GABA) to give MAG 2 GABA and then converted to NHS-MAG 2 GABA and conjugated to biocytin to give the MGB. To label MGB with 188 Re (50mA), ag, 200ml 1M tartrate pH7, 200 l stannous (10mg/mL) and 180MBq perrhenate were mixed and heated for 30min at 100 deg. C. The reactant was purified with C 18 Sep-Pak. HPLC analysis of the 188 Re-MGB performed on reverse phase C 18 column with a gradient. To see the stability, 188 Re-MGB was added to serum at 37 deg. C. Binding capacity of 188 Re-MGB to avidin or streptavidin was determined by size exclusion HPLC system. Biodistribution was studied in ICR normal mice(n=4/group), from 5min to 120min. In Raji cells tumour bearing nude mice(n=3), biotinylated Lym-1(40MEG) injection after 48 h, streptavidin(50MEG) was injected. 24 h later, 188 Re-MGB(0.5MEG) was injected, and biodistribution was observed 2 h later. 188 Re-MGB was obtained with labelling yield 98%. Stability in serum was maintained over 70% until 3 h. Binding capacity of 188 Re-MGB to streptavidin was greater than avidin. In normal mice, 188 Re-MGB was excreted via hepatobiliary pathway,%ID/g of GI tract was 52.1 at 120min. In Raji cells tumour bearing nude mice, liver and colon were higher than those of normal mouse. Tumour uptake at 120min was 0.05%ID/g. 188 Re-MGB was effectively labelled and retained binding activity with streptavidin. 188 Re-MGB may have a role in pretargeted radioimmunotherapy. (author)

Photogrammetry Of A Parabolic Antenna

Science.gov (United States)

Merrick, W. D.; Lansing, F. L.; Stoller, F. W.; Lobb, V. B.

1988-01-01

Surface measured with accuracy better than 10 to the negative fifth power times diameter. Report describes use of advanced close-range photogrammetry to determine deviations of 34-m-diameter antenna main reflector and subreflector from nominal paraboloidal shapes. Measurements enable removal of linear offsets and angular misalignments of subreflector, with consequent increase of 4 percent in aperture efficiency.

Magnetoelastic coupling in Sr2(Fe1-xCrx)ReO6 double perovskites

International Nuclear Information System (INIS)

Serrate, D; Teresa, J M De; Algarabel, P A; Marquina, C; Blasco, J; Ibarra, M R; Galibert, J

2007-01-01

We have investigated magnetoelastic coupling in Sr 2 (Fe 1-x Cr x )ReO 6 polycrystalline double perovskites. The end compound, Sr 2 CrReO 6 , shows a high ferromagnetic transition temperature of 635 K and is thought to exhibit a nearly half-metallic conduction band. We probed the unexpected high orbital moment borne by the Re atom by means of volume and anisotropic magnetostriction measurements in magnetic fields up to 12 T. Our magnetostriction results can be explained by the existence of a large spin-orbit coupling which, in combination with crystal-field effects, produces a single-ion type magnetostrictive response. The Re orbital moment triggers a greatly enhanced magnetocrystalline anisotropy compared to other ferromagnetic double perovskites. From our magnetostriction data, the temperature dependence of the coercive field as a function of Cr-doping is obtained. We discovered that the coercive field increases as Fe is replaced with Cr, which is linked to a strong enhancement of the magnetic anisotropy. This suggests a close relationship between the Fe[Cr]-O-Re coupling and the magnetic anisotropy. We also analysed the impact of the Re orbital moment on the spin-dependent transport across Sr 2 CrReO 6 grain boundaries. The present work opens up the possible use of these compounds for magnetostrictive applications in a wide temperature and magnetic field range

Experimental studies on the simultaneous reduction of NO and SO2 emissions by re burning

International Nuclear Information System (INIS)

Sun, Rui; Yu, Leibo; Fei, Jun; Mu, Yangyang; Zhang, Xin; Sun, Shaozeng; Wu, Shaohua

2010-01-01

The simultaneous reduction of NO and SO 2 by pulverized coal re burning was studied in a drop tube furnace (DTF). A bituminous pulverized coal was chosen as the re burning fuel, and calcium oxide was added as desulfurizer. The influences of stoichiometric ratio (SR), re burning temperature, calcium to sulfur ratio (Ca/ S), and residence time on efficiency of removing NO and SO 2 were studied by DTF hot experiments. The experiment results showed that, at the condition of the re burning temperature 1200 degree Celsius, Ca/ S=1.5, NO reduction efficiency decreased with the increase of re burning fuels stoichiometric ratio, but SO 2 reduction efficiency increased. When the re burning temperature increased from 1000 degree Celsius to 1200 degree Celsius, NO and SO 2 reduction efficiencies initially increased, but then decreased as temperature higher than 1100 degree Celsius. NO reduction efficiency decreased when Ca/ S changed from 1.0 to 2.5, and SO 2 reduction efficiency increased at all times, in spite of the increasing trend became flat when Ca/ S was higher than 2.0. Among all tests, high SO 2 and NO reduction ratios were obtained at SR of 0.8∼0.9 and Ca/ S of 1.5. The mechanisms of desulfurization and denitrification are also discussed and presented to explain the reactions routine in the DTF. (author)

Hierarchical architecture of ReS{sub 2}/rGO composites with enhanced electrochemical properties for lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Qi, Fei; Chen, Yuanfu, E-mail: yfchen@uestc.edu.cn; Zheng, Binjie; He, Jiarui; Li, Qian; Wang, Xinqiang; Lin, Jie; Zhou, Jinhao; Yu, Bo; Li, Pingjian; Zhang, Wanli

2017-08-15

Highlights: • The ReS{sub 2}/rGO composites have been synthesized by a facile one-pot method. • The ReS{sub 2}/rGO composites exhibit hierarchical architecture. • The ReS{sub 2}/rGO composites deliver better electrochemical performances than ReS{sub 2}. • The enhanced performance is due to porous and conductive structure of ReS{sub 2}/rGO. - Abstract: Rhenium disulfide (ReS{sub 2}), a two-dimensional (2D) semiconductor, has attracted more and more attention due to its unique anisotropic electronic, optical, mechanical properties. However, the facile synthesis and electrochemical property of ReS{sub 2} and its composite are still necessary to be researched. In this study, for the first time, the ReS{sub 2}/reduced graphene oxide (rGO) composites have been synthesized through a facile and one-pot hydrothermal method. The ReS{sub 2}/rGO composites exhibit a hierarchical, interconnected, and porous architecture constructed by nanosheets. As anode for lithium-ion batteries, the as-synthesized ReS{sub 2}/rGO composites deliver a large initial capacity of 918 mAh g{sup −1} at 0.2 C. In addition, the ReS{sub 2}/rGO composites exhibit much better electrochemical cycling stability and rate capability than that of bare ReS{sub 2}. The significant enhancement in electrochemical property can be attributed to its unique architecture constructed by nanosheets and porous structure, which can allow for easy electrolyte infiltration, efficient electron transfer, and ionic diffusion. Furthermore, the graphene with high electronic conductivity can provide good conductive passageways. The facile synthesis approach can be extended to prepare other 2D transition metal dichalcogenides semiconductors for energy storage and catalytic application.

Microstructural analyses and critical current densities in the high-Tc superconductor system ReBa2Cu3OX, with RE = Y, Sm, Eu, Gd, Dy, Ho

International Nuclear Information System (INIS)

Schindler, G.; Seebacher, B.

1989-01-01

The authors report on investigations into the impact of the rare earths (RE) as given in the title on the ceramic microstructure and the critical current density j c in the superconductor system REBa 2 Cu 3 O x . With RE = Sm, Eu, or Gd, the material is homogeneous in phase and crystallizes in platelets with maximum sizes of up to 350 μm. Material with RE = Y, Dy, or Ho exhibits grain sizes up to 500 μm, and a low amount of phase inhomogeneities. The critical currents measured are between 25 Acm -2 and 290 Acm -2 at 77 K, without external field. The highest values are found in systems with RE = Eu or Gd. (orig.) [de

Solubility and superconductivity in RE(Ba2-xREx)Cu3O7+δ (RE = Nd, Sm, Eu, Gd, Dy)

International Nuclear Information System (INIS)

Zhang, K.; Dabrowski, B.; Segre, C.U.; Hinks, D.G.; Schuller, I.K.; Jorgensen, J.D.; Slaski, M.

1987-10-01

Solid solutions of RE(Ba 2-x RE x )Cu 3 O 7- δ (RE=Nd,Sm,Eu,Gd,Dy) for x=0 to x=0.5 have been investigated. X-ray and resistivity measurements show that there exists a solid solution region, through which, the structure changes from orthorhombic to tetragonal and the superconducting properties are depressed. The solubility limits depend strongly on the size of the rare-earth ion, with the smallest (Dy) showing no appreciable solubility. The superconducting transition temperature versus x for all of the rare-earth ion substitutions falls on a universal curve, indicating that the Ba sites are extremely ionic and magnetically isolated. 20 refs., 4 figs

La question locale comme nouvelle frontière socio-spatiale

Directory of Open Access Journals (Sweden)

Christophe Gibout

2009-06-01

Full Text Available Partant de l’objet football socialement reconnu et de deux formes de pratique préalablement identifiées – pratiques fédérale et de « pied d’immeuble » – notre travail interroge l’influence et l’importance de la localisation dans la définition formelle des pratiques et la compréhension de leurs logiques identitaires. Parce que les pratiquants déploient des « arts de faire » singuliers sur un territoire jouant le rôle de lien et de liant, notre enquête montre que la dichotomie rural/urbain ne semble plus aujourd’hui heuristiquement pertinente pour comprendre le construit de la pratique sportive. Dès lors émerge la question locale – celle du « chez soi » – comme élément central de la construction sociale de la pratique sportive ; en témoigne la réalité d’une autre forme de football, non exclusive des deux autres : le football « sauvage ».The local question as a new socio-spatial frontierBeyond opposition between urban and rural soccer: the “at home” oneOn the basis of socially recognized football and of two beforehand identified forms of practice – official soccer and football played at the foot of one's building – our work questions the influence and the importance of the localization in the definition of the practices and in the comprehension of their identity logics. Because of the players use « second hand habits » on a territory playing the part of bond and binder, our investigation shows that the rural/urban dichotomy doesn’t seem any more relevant today to understand the construction of sport’s practice. Consequently emerges the local question – the one of « at home » – as central element of the social construction of the sport’s practice as testified to the reality of another form of football, nonexclusive of both others: « wild » football.Lo local como nueva frontera socio-espacialMas allá de la oposición entre el futbol urbano y el futbol rural

(Re)constructing Reflexivity: A Relational Constructionist Approach

NARCIS (Netherlands)

Hosking, D.M.; Pluut, B.

2010-01-01

This article distinguishes three discourses of reflexivity in relation to human inquiry. One of these arises from a post-modern, relational constructionist perspective which radically re-conceptualizes reflexivity: (a) as a local and co-constructed process oriented towards the question (b) how are

Observation of anisotropic interlayer Raman modes in few-layer ReS{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Nagler, Philipp; Plechinger, Gerd; Schueller, Christian; Korn, Tobias [Institut fuer Experimentelle und Angewandte Physik, Universitaet Regensburg, 93040, Regensburg (Germany)

2016-02-15

ReS{sub 2} has recently emerged as a new member in the rapidly growing family of two-dimensional materials. Unlike MoS{sub 2} or WSe{sub 2}, the optical and electrical properties of ReS{sub 2} are not isotropic due to the reduced symmetry of the crystal. Here, we present layer-dependent Raman measurements of ReS{sub 2} samples ranging from monolayers to ten layers in the ultralow frequency regime. We observe layer breathing and shear modes which allow for easy assignment of the number of layers. Polarization-dependent measurements give further insight into the crystal structure and reveal an energetic shift of the shear mode which stems from the in-plane anisotropy of the shear modulus in this material. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

37 CFR 354.2 - Novel questions.

Science.gov (United States)

2010-07-01

... of law, referral to the Register of Copyrights by the Copyright Royalty Judges is mandatory. A “novel... discretionary referral of material questions of copyright law to the Register of Copyrights by the Copyright... Copyrights in resolving material questions of substantive law is binding upon the Copyright Royalty Judges...

Synthesis and photoluminescence properties of microcrystalline Sr{sub 2}ZnWO{sub 6}:RE{sup 3+} (RE = Eu, Dy, Sm and Pr) phosphors

Energy Technology Data Exchange (ETDEWEB)

Dabre, K.V. [Department of Physics, Arts, Commerce and Science College, Koradi, Nagpur 441111 (India); Park, K. [Faculty of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul 143-747 (Korea, Republic of); Dhoble, S.J., E-mail: sjdhoble@rediffmail.com [Department of Physics, R.T.M. Nagpur University, Nagpur 440033 (India)

2014-12-25

Graphical abstract: CIE chromaticity coordinate diagram (1931) indicating different colors of Sr{sub 2}ZnWO{sub 6}:RE{sup 3+} (RE = Eu (a), Dy (b and c), Sm (d–f) and Pr (g and h)) phosphor under different excitation 466 nm (a), 312 nm (b), 454 nm (c), 313 nm (d), 408 nm (e), 482 nm (f), 315 nm (g) and 450 nm (h). - Highlights: • Microcrystalline Sr{sub 2}ZnWO{sub 6}:RE{sup 3+} (RE = Eu, Dy, Sm and Pr) phosphors were synthesized by solid state method. • Photoluminescence properties of phosphor were investigated. • Color of the phosphor for different excitation has been verified by chromaticity diagram. • The host absorption and energy transfer were investigated. - Abstract: The novel microcrystalline Sr{sub 2}ZnWO{sub 6}:RE{sup 3+} (RE = Eu, Dy, Sm and Pr) phosphors were synthesized by solid-state reaction method at 1250 °C and their photoluminescence properties were investigated. The Eu{sup 3+} and Dy{sup 3+} activated phosphors show intense red (616 nm) and yellow (574 nm) emission respectively; which indicate that the rare earth ions are substituted at non-centrosymmetric site in the host lattice. Near white (Dy{sup 3+}) and reddish-orange (Sm{sup 3+}) emissions of rare earth ions in the host lattice show strong host absorption and energy transfer from the host to activator ion. Pr{sup 3+} activated phosphor shows a series of emission peaks in the visible region with the most intense peak in the blue region at 491 and 499 nm.

Experimental evaluation of ontology-based HIV/AIDS frequently asked question retrieval system.

Science.gov (United States)

Ayalew, Yirsaw; Moeng, Barbara; Mosweunyane, Gontlafetse

2018-05-01

This study presents the results of experimental evaluations of an ontology-based frequently asked question retrieval system in the domain of HIV and AIDS. The main purpose of the system is to provide answers to questions on HIV/AIDS using ontology. To evaluate the effectiveness of the frequently asked question retrieval system, we conducted two experiments. The first experiment focused on the evaluation of the quality of the ontology we developed using the OQuaRE evaluation framework which is based on software quality metrics and metrics designed for ontology quality evaluation. The second experiment focused on evaluating the effectiveness of the ontology in retrieving relevant answers. For this we used an open-source information retrieval platform, Terrier, with retrieval models BM25 and PL2. For the measurement of performance, we used the measures mean average precision, mean reciprocal rank, and precision at 5. The results suggest that frequently asked question retrieval with ontology is more effective than frequently asked question retrieval without ontology in the domain of HIV/AIDS.

Influence of rare-earth ions on SiO{sub 2}-Na{sub 2}O-RE{sub 2}O{sub 3} glass structure

Energy Technology Data Exchange (ETDEWEB)

Johnson, J A [Department of Materials Science and Engineering, University of Tennessee Space Institute, Tullahoma, TN 37388 (United States); Benmore, C J [X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Holland, D [Department of Physics, University of Warwick, CV4 7AL (United Kingdom); Du, J [Department of Material Science and Engineering, University of North Texas, Denton, TX 76203 (United States); Beuneu, B [Laboratoire Leon Brillouin, CEA-CNRS, CEA/Saclay, F-91191 Gif-sur-Yvette (France); Mekki, A, E-mail: jjohnson@utsi.edu [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

2011-02-16

Praseodymium and europium sodium silicate glasses of nominal composition (SiO{sub 2}){sub 0.70-x}(Na{sub 2}O){sub 0.30}(RE{sub 2}O{sub 3}){sub x}, where RE is the rare earth and 0 {<=} x {<=} 0.10, were studied by neutron and high-energy x-ray scattering and classical molecular dynamics simulations. The observation of a significant x-ray intensity in doped as compared to un-doped glasses is indicative of RE-RE correlations at a distance of {approx} 3.7-3.9 A, much shorter than would be expected for a homogeneous distribution, suggesting that clustering of the rare-earth cations occurs in both these glass systems at low concentrations. Above x = 0.075 (nominal), minimal changes in this region indicate that the RE atoms are incorporated much more randomly into the glass structure. The molecular dynamics simulations suggest that the rare-earth ions enter the sodium-rich regions in the sodium silicate glasses and act as modifiers. A cluster analysis performed on the model systems indicates that the tendency for clustering is higher in praseodymium-containing glasses than in the europium glasses.

IDC Re-Engineering Phase 2 Glossary Version 1.3

Energy Technology Data Exchange (ETDEWEB)

Young, Christopher J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Harris, James M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-01-01

This document contains the glossary of terms used for the IDC Re-Engineering Phase 2 project. This version was created for Iteration E3. The IDC applies automatic processing methods in order to produce, archive, and distribute standard IDC products on behalf of all States Parties.

Re-OPCAB vs. Re-CABG for myocardial revascularization.

Science.gov (United States)

Schütz, A; Mair, H; Wildhirt, S M; Gillrath, G; Lamm, P; Kilger, E; Reichart, B

2001-06-01

The present study compared redo coronary artery bypass grafting (Re-OPCAB) techniques with conventional redo coronary artery bypass grafting (Re-CABG) with particular focus on myocardial damage and clinical outcome parameters. Redo OPCAB (Re-OPCAB) was performed on 20 consecutive patients (15 males, mean age 63.2 +/- 9.3 years) using either the anterolateral approach for minimally invasive direct coronary artery bypass (n = 4) or the Octopus technique with regular sternotomy (n = 16). The Re-CABG group consisted of 20 consecutive patients (18 males, mean age 67.1 +/- 6.6 years). Groups did not differ in the number of atherosclerotic risk factors, or left ventricular, renal or liver function. Duration of surgery, number of bypass grafts and amount of transfused red blood cells did not differ significantly between both groups. Requirement of epinephrine (mg/h) within the first 24 h was lower in the Re-OPCAB group (Re-OPCAB: 0.14 +/- 0.22 vs. CABG: 0.88 +/- 0.97; p<0.01). In addition, CKMB levels at 24 h after operation were lower in the Re-OPCAB group (Re-OPCAB: 10.0 +/- 10.1 vs. Re-CABG: 38.7 +/- 28.1 U/l, p<0.001). There were no acute myocardial infarctions or deaths in the perioperative period. In the CABG group, there was a longer time period to extubation (hours) (Re-OPCAB: 9.8 +/- 3.9 vs. Re-CABG: 28.7 +/- 25.5; p<0.001), and the length of ICU stay was significantly prolonged (OPCAB: 1.3 +/- 0.5 versus Re-CABG: 4.4 +/- 8.7; p<0.001). The graft patency rate at follow-up was 95% in the Re-OPCAB group. Re-OPCAB results in decreased cardiac specific enzyme release, reduced requirement of inotropes and comparable clinical outcome in the early postoperative period. It is an appropriate alternative to conventional Re-CABG in selected patients awaiting reoperation for myocardial revascularization. Larger prospective and randomized trials are required to select the appropriate patient who benefits most from one or the other treatment regime.

Cancer-promoting tumor-associated macrophages: new vistas and open questions.

Science.gov (United States)

Mantovani, Alberto; Germano, Giovanni; Marchesi, Federica; Locatelli, Marco; Biswas, Subhra K

2011-09-01

Tumor-associated macrophages (TAMs) are key components of the tumor macroenvironment. Cancer- and host cell-derived signals generally drive the functions of TAMs towards an M2-like polarized, tumor-propelling mode; however, when appropriately re-educated. TAMs also have the potential to elicit tumor destructive reactions. Here, we discuss recent advances regarding the immunobiology of TAMs and highlight open questions including the mechanisms of their accumulation (recruitment versus proliferation), their diversity and how to best therapeutically target these cells. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ternary rare-earth bismuthides RE5SiBi 2 and RE5GeBi 2 ( RE=La-Nd, Gd-Er): Stabilization of the β-Yb 5Sb 3-type structure through tetrel substitution

Science.gov (United States)

Barry, Stephen D.; Tkachuk, Andriy V.; Bie, Haiying; Blanchard, Peter E. R.; Mar, Arthur

2011-01-01

Ternary bismuthides RE5TtBi 2 containing rare-earth ( RE=La-Nd, Gd-Er) and tetrel ( Tt=Si, Ge) atoms have been prepared by arc-melting of the elements followed by annealing at 800 °C. They adopt the β-Yb 5Sb 3-type structure (Pearson symbol o P32, space group Pnma, Z=4), as revealed through analysis by single-crystal X-ray diffraction on Ce 5Si 0.869(4)Bi 2.131(4) and powder X-ray diffraction on Ce 5GeBi 2. Cell parameters for the entire series lie in the ranges of a=12.8-11.8 Å, b=9.6-9.0 Å, and c=8.4-7.9 Å. Solid solubility in Ce 5Si xBi 3- x and Pr 5Si xBi 3- x (approximately 0.9≤ x≤1.2, depending on the RE member) is much more limited compared to the antimonides, consistent with a highly ordered structure in which the two possible anion sites are essentially segregated into a smaller one occupied by Tt atoms (CN7) and a larger one occupied by Bi atoms (CN9). Band structure calculations on La 5SiBi 2 confirm the importance of La-La bonding interactions near the Fermi level. X-ray photoelectron spectra support the presence of partially anionic Bi atoms, as indicated by a small negative binding energy shift relative to elemental Bi. The Ce and Pr members undergo magnetic transitions at low temperatures, possibly involving ferromagnetic interactions, that are strongly influenced by the nature of the Tt atom.

Delay Management with Re-Routing of Passengers

NARCIS (Netherlands)

T.A.B. Dollevoet (Twan); D. Huisman (Dennis); M.E. Schmidt (Marie); A. Schöbel (Anita)

2010-01-01

textabstractThe question of delay management is whether trains should wait for a delayed feeder train or should depart on time. In classical delay management models passengers always take their originally planned route. In this paper, we propose a model where re-routing of passengers is

In vivo examination of {sup 188}Re(I)-tricarbonyl-labeled trastuzumab to target HER2-overexpressing breast cancer

Energy Technology Data Exchange (ETDEWEB)

Chen, K.-T. [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Lee, T.-W. [Institute of Nuclear Energy Research, Longtan 32546, Taiwan (China); Lo, Jem-Mau [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Institute of Nuclear Engineering and Science, National Tsing Hua University, Hsinchu 30013, Taiwan (China)], E-mail: jmlo@mx.nthu.edu.tw

2009-05-15

Introduction: Trastuzumab (Herceptin), a humanized IgG1 monoclonal antibody directed against the extracellular domain of the HER2 protein, acts as an immunotherapeutic agent for HER2-overexpressing human breast cancers. Radiolabeled trastuzumab with {beta}- or {alpha} emitters can be used as radioimmunotherapeutic agent for the similar purpose but with additional radiation effect. Methods: In this study, trastuzumab was labeled with {sup 188}Re for radioimmunotherapy of HER2/neu-positive breast cancer. {sup 188}Re(I)-tricarbonyl ion, [{sup 188}Re(OH{sub 2}){sub 3}(CO){sub 3}]{sup +}, was employed as a precursor for directly labeling the monoclonal antibody with {sup 188}Re. The immunoreactivity of {sup 188}Re(I)-trastuzumab was estimated by competition receptor-binding assay using HER2/neu-overexpressive BT-474 human breast cancer cells. The localization properties of {sup 188}Re(I)-trastuzumab within both tumor and normal tissues of athymic mice bearing BT-474 human breast cancer xenografts (HER2/neu-overexpressive) and similar mice bearing MCF-7 human breast cancer xenografts (HER2/neu-low expressive) were investigated. Results: When incubated with human serum albumin and histidine at 25{sup o}C, {sup 188}Re(I)-trastuzumab was found to be stable within 24 h. The IC{sub 50} of {sup 188}Re(I)-trastuzumab was found to be 22.63{+-}4.57 nM. {sup 188}Re(I)-trastuzumab was shown to accumulate specifically in BT-474 tumor tissue in in vivo biodistribution studies. By microSPECT/CT, the image of {sup 188}Re localized BT-474 tumor was clearly visualized within 24 h. In contrast, {sup 188}Re(I)-trastuzumab uptake in HER2-low-expressing MCF-7 tumor was minimal, and the {sup 188}Re image at the localization of the tumor was dim. Conclusion: These results reveal that {sup 188}Re(I)-trastuzumab could be an appropriate radioimmunotherapeutic agent for the treatment of HER2/neu-overexpressing cancers.

All-electron study of ultra-incompressible superhard material ReB2: structural and electronic properties

International Nuclear Information System (INIS)

Yan-Ling, Li; Guo-Hua, Zhong; Zhi, Zeng

2009-01-01

This paper investigates the structural and electronic properties of rhenium diboride by first-principles calculation based on density functional theory. The obtained results show that the calculated equilibrium structural parameters of ReB 2 are in excellent agreement with experimental values. The calculated bulk modulus is 361 GPa in comparison with that of the experiment. The compressibility of ReB 2 is lower than that of well-known OsB 2 . The anisotropy of the bulk modulus is confirmed by c/a ratio as a function of pressure curve and the bulk modulus along different axes along with the electron density distribution. The high bulk modulus is attributed to the strong covalent bond between Re-d and B-p orbitals and the wider pseudogap near the Fermi level, which could be deduced from both electron charge density distribution and density of states. The band structure and density of states of ReB 2 exhibit that this material presents metallic behavior. The good metallicity and ultra-incompressibility of ReB 2 might suggest its potential application as pressure-proof conductors. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Multimodal Person Re-identification Using RGB-D Sensors and a Transient Identification Database

DEFF Research Database (Denmark)

Møgelmose, Andreas; Moeslund, Thomas B.; Nasrollahi, Kamal

2013-01-01

This paper describes a system for person re-identification using RGB-D sensors. The system covers the full flow, from detection of subjects, over contour extraction, to re-identification using soft biometrics. The biometrics in question are part-based color histograms and the subjects height...

Institutional Innovation: Re-invigorating the University through Transdisciplinary Engagement

Directory of Open Access Journals (Sweden)

Gale Moore

2011-11-01

Full Text Available The view that ICTs-and-Society is a transdiscipline offers great potential as a way forward. As the community moves toward a shared understanding of what constitutes transdisciplinary engagement a series of new questions are raised. This paper reflects on one of them – the question of how transdisciplinarity can be accomplished in the university. The argument advanced is that by re-framing the challenges of accommodating transdisciplinarity as an opportunity for institutional innovation there is potential to increase the support for research on ICTs-and-Society in the university, and to provide university administrators with a way to demonstrate leadership by adopting a broader innovation agenda that could re-invigorate the university and strengthen its relationship with the broader community in which it is situated.

Question marks concerning CO2 trade after 2012

International Nuclear Information System (INIS)

Wellander, Dag

2006-01-01

Different aspects of the Kyoto protocol are discussed, from the (in)significance of the Kyoto protocol, the inefficiency of the CO 2 trade system, to questions about how electricity prices will be affected in the EU, and what will be the solution in the future when the Kyoto agreement ends in 2012

Chemical ordering in substituted fluorite oxides: a computational investigation of Ho2Zr2O7 and RE2Th2O7 (RE=Ho, Y, Gd, Nd, La)

Science.gov (United States)

Solomon, Jonathan M.; Shamblin, Jacob; Lang, Maik; Navrotsky, Alexandra; Asta, Mark

2016-12-01

Fluorite-structured oxides find widespread use for applications spanning nuclear energy and waste containment, energy conversion, and sensing. In such applications the host tetravalent cation is often partially substituted by trivalent cations, with an associated formation of charge-compensating oxygen vacancies. The stability and properties of such materials are known to be influenced strongly by chemical ordering of the cations and vacancies, and the nature of such ordering and associated energetics are thus of considerable interest. Here we employ density-functional theory (DFT) calculations to study the structure and energetics of cation and oxygen-vacancy ordering in Ho2Zr2O7. In a recent neutron total scattering study, solid solutions in this system were reported to feature local chemical ordering based on the fluorite-derivative weberite structure. The calculations show a preferred chemical ordering qualitatively consistent with these findings, and yield values for the ordering energy of 9.5 kJ/mol-cation. Similar DFT calculations are applied to additional RE2Th2O7 fluorite compounds, spanning a range of values for the ratio of the tetravalent and trivalent (RE) cation radii. The results demonstrate that weberite-type order becomes destabilized with increasing values of this size ratio, consistent with an increasing energetic preference for the tetravalent cations to have higher oxygen coordination.

Re-Appropriating a Question/Answer System to Support Dialectical Constructivist Learning Activity

Science.gov (United States)

Carroll, John M.; Wu, Yu; Shih, Patrick C.; Zheng, Saijing

2016-01-01

Learning can be engaged by dialectic, that is, by identifying pros and cons that inhere in propositions, and more generally, by raising questions about the validity of claims. We report here on a classroom case study of dialectical constructivist pedagogy: Students created dialectical analyses of two lectures and four books as core activities in a…

Labelling of Re-ABP with 188Re for bone pain palliation

International Nuclear Information System (INIS)

Arteaga de Murphy, Consuelo; Ferro-Flores, Guillermina; Pedraza-Lopez, Martha; Melendez-Alafort, Laura; Croft, B.Y.Barbara Y.; Ramirez, Flor de Maria; Padilla, Juan

2001-01-01

Etidronate and medronate have been labelled with technetium-99m ( 99m Tc-HEDP, 99m Tc-MDP) for bone scanning and, with rhenium-188 ( 188 Re-HEDP) to palliate the pain resulting from bone metastases. The objective of this study was to label alendronate, ABP, a new bisphosphonate, with SnF 2 -reduced- 188 Re. The reagents for the 5 mg ABP kit were SnF 2 , KReO 4 and gentisic acid at acid pH. The chemical, spectroscopic and microscopic characteristics, quality control, rat bone uptake of [ 188 Re]Re-ABP and similarities with 99m Tc-ABP are presented. We conclude that this is a promising new radiopharmaceutical for bone metastases pain palliation

Ternary germanides RERhGe{sub 2} (RE = Y, Gd-Ho) – New representatives of the YIrGe{sub 2} type

Energy Technology Data Exchange (ETDEWEB)

Voßwinkel, Daniel; Heletta, Lukas; Hoffmann, Rolf-Dieter; Pöttgen, Rainer, E-mail: pottgen@uni-muenster.de

2016-11-15

The YIrGe{sub 2} type ternary germanides RERhGe{sub 2} (RE = Y, Gd-Ho) were synthesized from the elements by arc-melting and characterized by powder X-ray diffraction. The structure of DyRhGe{sub 2} was refined from single crystal X-ray diffractometer data: Immm, a = 426.49(9), b = 885.0(2), c = 1577.4(3) pm, wR2 = 0.0533, 637 F{sup 2} values, 30 variables (300 K data). The structure contains two crystallographically independent dysprosium atoms in pentagonal prismatic and hexagonal prismatic coordination. The three-dimensional [RhGe{sub 2}] polyanion is stabilized through covalent Rh–Ge (243–261 pm) and Ge–Ge (245–251 pm) bonding. The close structural relationship with the slightly rhodium-poorer germanides RE{sub 5}Rh{sub 4}Ge{sub 10} (≡ RERh{sub 0.8}Ge{sub 2}) is discussed. Temperature-dependent magnetic susceptibility measurements reveal Pauli paramagnetism for YRhGe{sub 2} and Curie-Weiss paramagnetism for RERhGe{sub 2} with RE = Gd, Tb, Dy and Ho. These germanides order antiferromagnetically at T{sub N} = 7.2(5), 10.6(5), 8.1(5), and 6.4(5) K, respectively. - Graphical abstract: The germanides RERhGe{sub 2} (RE = Y, Gd-Ho) are new representatives of the YIrGe{sub 2} type.

Different diffusion mechanisms of oxygen in ReBa{sub 2}Cu{sub 3}O{sub 7−x} (Re = Y, Ho) single crystals

Energy Technology Data Exchange (ETDEWEB)

Vovk, R.V.; Boiko, Y.I.; Bogdanov, V.V.; Kamchatnaya, S.N.; Goulatis, I.L. [V. N. Karazin Kharkiv National University, 4 Svobody sq., 61077 Kharkiv (Ukraine); Chroneos, A. [Faculty of Engineering, Environment and Computing, Coventry University, Priory Street, Coventry CV1 5FB (United Kingdom); Department of Materials, Imperial College London, London SW7 2AZ (United Kingdom)

2017-05-15

Highlights: • Single file diffusion mechanism of oxygen ions. • Ho modifies the diffusion mechanism in the oxygen sublattice. • Ho changes the efficient interaction of ions in CuO-planes. - Abstract: In the present study, the time dependencies of the resistivity of ReBa{sub 2}Cu{sub 3}O{sub 7−x} (Re=Y, Ho) single crystals with varying degree of deviation from oxygen stoichiometry was investigated. It was shown that the accelerated transport of oxygen ions in the initial stage of the process can be carried out along the one-dimensional non-stoichiometric vacancies’ accumulation by the single file diffusion mechanism. The final phase redistribution of oxygen ions in ReBa{sub 2}Cu{sub 3}O{sub 7−x} (Re = Y, Ho) is described by the classical mechanism of volume diffusion. The substitution of yttrium by holmium significantly affects the charge redistribution and changes the efficient interaction of ions in CuO-planes, thereby modifying the mass transfer diffusion mechanisms in the oxygen sublattice. Thus, a significant length change of the time intervals occurs, corresponding to the oxygen ions’ single file and volume diffusion mechanisms.

Hexagonal perovskites with cationic vacancies. 7. Vibrational spectroscopic investigations on the rhombohedral 12 L-stacking polytypes Ba/sub 4/Bsup(II)(Re/sub 2/vacantO/sub 12/) and Ba/sub 4/Bsub(2/3)sup(III)vacantsub(1/3)(Re/sub 2/vacantO/sub 12/)

Energy Technology Data Exchange (ETDEWEB)

Fadini, A; Kemmler-Sack, S; Schittenhelm, H J; Rother, H J; Treiber, U [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1979-07-01

For the rhombohedral 12 L stacking polytypes Ba/sub 4/Bsup(II)(Re/sub 2/vacantO/sub 12/) and Ba/sub 4/Bsub(2/3)sup(III)vacantsub(1/3)(Re/sub 2/vacantO/sub 12/), space group R3m, sequence (3)(1), the lattice consists of groups of three face sharing octahedra with the composition Re/sub 2/vacantO/sub 12/. They are isolated from each other by the Ba and B ions. The vibrational spectra are interpreted according to the factor group analysis. For the Re/sub 2/vacantO/sub 12/ unit (symmetry Dsub(3d) the results of a complete vibrational analysis and the calculation of the force constants are reported.

An investigation on the tribological properties of Co(ReO4)2/MoS2 composite as potential lubricating additive at various temperatures

Science.gov (United States)

Wang, Junhai; Lu, Bing; Zhang, Lixiu; Li, Ting; Yan, Tingting; Li, Mengxu

2018-02-01

The Co(ReO4)2 powder was fabricated via the aqueous solution method, and mixed with MoS2 powder using ball milling technique. A certain concentration of Co(ReO4)2/MoS2 composite additive was dispersed into the poly alpha olefin base oil with the assistance of surface active agents. The load-carrying property and lubricating behavior of base oil containing a certain content of Co(ReO4)2/MoS2 composite additive at various temperatures were evaluated by four-ball test and ball-on-disc sliding friction test. The physical properties and friction-reducing mechanism of synthesized composite were ascertained by a series of characterization techniques including X-ray diffraction, scanning electron microscopy-energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and differential thermal analysis/thermogravimetry. The four-ball test results suggested the Co(ReO4)2/MoS2 composite additive could effectively promote the load-carrying capacity of base oil, and decrease the friction coefficient as well as wear scar diameter. Ball-on-disc sliding friction test results showed that the base oil with Co(ReO4)2/MoS2 composite additive possessed lower friction coefficients than that of base oil in the whole temperature range, particularly at high temperatures. The protective layer consisted of composite additive and native oxides from superalloy substrate formed on the worn surface to prevent the direct contact between friction pair. The Co(ReO4)2/MoS2 composite played a dominant role in friction-reducing function in the protective layer at elevated temperatures, and the reason for this was that MoS2 possessed layered structure and superior adsorption capacity, and Co(ReO4)2 had experienced thermal softening with elevated temperatures and maintained shear-susceptible hexagonal structure.

Magnetic interactions in rhenium-containing rare earth double perovskites Sr{sub 2}LnReO{sub 6} (Ln=rare earths)

Energy Technology Data Exchange (ETDEWEB)

Nishiyama, Atsuhide; Doi, Yoshihiro; Hinatsu, Yukio, E-mail: hinatsu@sci.hokudai.ac.jp

2017-04-15

The perovskite-type compounds containing both rare earth and rhenium Sr{sub 2}LnReO{sub 6} (Ln=Y, Tb-Lu) have been prepared. Powder X-ray diffraction measurements and Rietveld analysis show that Ln{sup 3+} and Re{sup 5+} ions are structurally ordered at the B site of the perovskite SrBO{sub 3}. Magnetic anomalies are found in their magnetic susceptibility and specific heat measurements at 2.6–20 K for Ln=Y, Tb, Dy, Yb, Lu compounds. They are due to magnetic interactions between Re{sup 5+} ions. The results of the magnetic hysteresis and remnant magnetization measurements for Sr{sub 2}YReO{sub 6} and Sr{sub 2}LuReO{sub 6} indicate that the antiferromagnetic interactions between Re{sup 5+} ions below transition temperatures have a weak ferromagnetic component. The analysis of the magnetic specific heat data for Sr{sub 2}YbReO{sub 6} shows that both the Yb{sup 3+} and Re{sup 5+} ions magnetically order at 20 K. For the case of Sr{sub 2}DyReO{sub 6}, magnetic ordering of the Re{sup 5+} moments occurs at 93 K, and with decreasing temperature, the moments of Dy{sup 3+} ferromagnetically order at 5 K from the measurements of magnetic susceptibility and specific heat. - Graphical abstract: Crystal structure of double perovskite Sr{sub 2}LnReO{sub 6}. Red and black lines show cubic and monoclinic unit cells, respectively. - Highlights: • Double perovskites Sr{sub 2}LnReO{sub 6} (Ln=rare earths) were prepared. • They show an antiferromagnetic transition at 2.6–20 K. • In Sr{sub 2}DyReO{sub 6}, Dy and Re moments magnetically order at 5 and 93 K, respectively.

Magnetic transitions in double perovskite Sr2FeRe1-xSbxO6 (0≤x≤0.9)

International Nuclear Information System (INIS)

Jung, Alexandra; Ksenofontov, Vadim; Reiman, Sergey; Therese, Helen Annal; Felser, Claudia; Tremel, Wolfgang; Kolb, Ute

2006-01-01

The double perovskites Sr 2 FeMO 6 (M=Re,Mo) belong to the important class of half-metallic magnetic materials. In this study we explore the effect of replacing the electronic 5d buffer element Re with variable valency by the main group element Sb with fixed valency. X-ray diffraction reveals Sr 2 FeRe 1-x Sb x O 6 (0 2 FeReO 6 changes to antiferromagnetic upon Sb substitution as was determined by magnetic susceptibility measurements. Samples up to a doping level of 0.3 are ferrimagnetic, while Sb contents higher than 0.6 result in an overall antiferromagnetic behavior. 57 Fe and 121 Sb Moessbauer spectroscopy specifies the valence state of Sb to be +5 within the whole range of substitution whereas the Fe valence state changes from +2.7 for the parent compound to +2.9 for Sr 2 FeRe 0.1 Sb 0.9 O 6 . Accordingly, Fe adopts the role of an electronic buffer element from Re upon heavy Sb doping. Additionally, 57 Fe Moessbauer results show a coexistence of ferri- and antiferromagnetic clusters within the same perovskite-type crystal structure in the Sb substitution range 0.3 2 FeReO 6 and Sr 2 FeRe 0.9 Sb 0.1 O 6 are ''purely'' ferrimagnetic and Sr 2 FeRe 0.1 Sb 0.9 O 6 contains antiferromagnetically ordered Fe sites only. Consequently, a replacement of the Re atoms by a nonmagnetic main group element such as Sb blocks the superexchange pathways -Fe-O-Re(Sb)-O-Fe- along the crystallographic axis of the perovskite unit cell and destroys the itinerant magnetism of the parent compound

Investigations of the trend followed in heat capacity of Re_6UO_1_2 (s) along lanthanide series

International Nuclear Information System (INIS)

Sahu, Manjulata; Saxena, M.K.; Rawat, Deepak; Dash, Smruti

2017-01-01

The compound RE_6UO_1_2 (s) (RE = Ho, Er, Tm, Yb and Lu) was synthesized by complex polymerisation method and characterised using X-ray diffraction (XRD). Heat capacity measurements of RE_6UO_1_2 (s) were performed with heat flux-type differential scanning calorimeter in the temperature range of 300-870 K. The trend in heat capacity along the rare earth series was proposed for RE_6UO_1_2 (s) and thermodynamic functions were generated. (author)

Theoretical analysis of hydrogen chemisorption on Pd(111), Re(0001) and PdML/Re(0001), ReML/Pd(111) pseudomorphic overlayers

DEFF Research Database (Denmark)

Pallassana, Venkataraman; Neurock, Matthew; Hansen, Lars Bruno

1999-01-01

not appear to provide an independent parameter for assessing surface reactivity. The weak chemisorption of hydrogen on the Pd-ML/Re(0001) surface relates to substantial lowering of the d-band center of Pd, when it is pseudomorphically deposited as a monolayer on a Re substrate. [S0163-1829(99)00331-2].......Gradient-corrected density-functional theory (DFT-GGA) periodic slab calculations have been used to analyze the binding of atomic hydrogen on monometallic Pd(111), Re(0001), and bimetallic Pd-mL/Re(0001) [pseudomorphic monolayer of Pd(111) on Re(0001)] and Re-ML/Pd(111) surfaces. The computed...

Studies of HEDP labelled with 188Re from different generators of 188W /188Re

International Nuclear Information System (INIS)

Marczewski, Barbara Szot

2006-01-01

The widespread interest in 188 Re for therapeutic applications, is due to its attractive 16,9 hours half-life, emission of a β - particle with maximum energy of 2.12 MeV and gamma-ray of 155 keV suitable for imaging. This work presents the radiolabelling of HEDP (etidronate) with 188 Re eluted from alumina-based 188 W/ 188 Re generators and tungstate-based 188 W/ 188 Re gel generators. Dependence of the yield of the 18 '8Re-HEDP on the concentration of the reduction agent, p H, reaction time, temperature and addition of carrier Re 2 O 7 were evaluated. The radiolabelling of 188 Re-HEDP procedure using the optimum conditions resulted a yield >= 98% for liquid and lyophilized kits. This basic formulation contains: 30 mg de HEDP, 7 mg de SnCl 2 , 3 mg de ascorbic acid and addition of 20 mug of Re 2 O 7 . The reactions were carried out with heating in boiling water for 30 minutes followed by 60 minutes of incubation. Another important aspect of this work was the radiochemical quality control comparing the results of PC, TLC and ion chromatography, along with the experiments with HPLC. The biological distribution proved the adequate bone uptake and in vivo stability of 188 Re-HEDP complexes. (author)

Measurements of the microwave spectrum, Re-H bond length, and Re quadrupole coupling for HRe(CO)5

Science.gov (United States)

Kukolich, Stephen G.; Sickafoose, Shane M.

1993-11-01

Rotational transition frequencies for rhenium pentacarbonyl hydride were measured in the 4-10 GHz range using a Flygare-Balle type microwave spectrometer. The rotational constants and Re nuclear quadrupole coupling constants for the four isotopomers, (1) H187Re(CO)5, (2) H185Re(CO)5, (3) D187Re(CO)5, and (4) D185Re(CO)5, were obtained from the spectra. For the most common isotopomer, B(1)=818.5464(2) MHz and eq Q(187Re)=-900.13(3) MHz. The Re-H bond length (r0) determined by fitting the rotational constants is 1.80(1) Å. Although the Re atom is located at a site of near-octahedral symmetry, the quadrupole coupling is large due to the large Re nuclear moments. A 2.7% increase in Re quadrupole coupling was observed for D-substituted isotopomers, giving a rather large isotope effect on the quadrupole coupling. The Cax-Re-Ceq angle is 96(1)°, when all Re-C-O angles are constrained to 180°.

Private Finance 2 (PF2): Re-inventing the Wheel?

Science.gov (United States)

Zawawi, N. A. W. A.; Abdul-Aziz, A. R.; Khamidi, M. F.; Othman, I.; Idrus, A.; Umar, A. A.

2013-06-01

The Procurement policy of any government is the most influential factor in determining the efficiency of infrastructure and service provision like roads, water supply and energy. The UK's HM Treasury released its new guidelines on private involvement in infrastructures provision and services towards reforming the popular Private Finance Initiatives (PFI) policy. This new approach, it now refers to as the Private Finance 2 (PF2) is meant to correct the imperfections which have bedeviled the older version-PFI. However, the 'new guidelines' contained nothing really new in the area of private financing and operation of public infrastructures, at best it is akin to 're-inventing the wheel' rather than being 'new'. While dwelling extensively on issues relating to cheaper financing sources, risks transfer, counterpart funding by government and improving public sector procurement skills, this paper argues that some countries in the developing world have long recognised these issues and taken practical steps to correct them.

Private Finance 2 (PF2): Re-inventing the Wheel?

International Nuclear Information System (INIS)

Zawawi, N A W A; Khamidi, M F; Othman, I; Umar, A A; Abdul-Aziz, A R; Idrus, A

2013-01-01

The Procurement policy of any government is the most influential factor in determining the efficiency of infrastructure and service provision like roads, water supply and energy. The UK's HM Treasury released its new guidelines on private involvement in infrastructures provision and services towards reforming the popular Private Finance Initiatives (PFI) policy. This new approach, it now refers to as the Private Finance 2 (PF2) is meant to correct the imperfections which have bedeviled the older version-PFI. However, the 'new guidelines' contained nothing really new in the area of private financing and operation of public infrastructures, at best it is akin to 're-inventing the wheel' rather than being 'new'. While dwelling extensively on issues relating to cheaper financing sources, risks transfer, counterpart funding by government and improving public sector procurement skills, this paper argues that some countries in the developing world have long recognised these issues and taken practical steps to correct them.

{sup 186}Re-maSGS-Z{sub HER2:342}, a potential affibody conjugate for systemic therapy of HER2-expressing tumours

Energy Technology Data Exchange (ETDEWEB)

Orlova, Anna; Tran, Thuy A. [Uppsala University, Division of Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala (Sweden); Ekblad, Torun; Karlstroem, Amelie Eriksson [Royal Institute of Technology, School of Biotechnology, Division of Molecular Biotechnology, Stockholm (Sweden); Tolmachev, Vladimir [Uppsala University, Division of Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala (Sweden); Uppsala University, Division of Nuclear Medicine, Department of Medical Sciences, Uppsala (Sweden)

2010-02-15

Affibody molecules are a novel class of tumour-targeting proteins, which combine small size (7 kDa) and picomolar affinities. The Affibody molecule Z{sub HER2:342} has been suggested for imaging of HER2 expression in order to select patients for trastuzumab therapy. When optimizing chelators for {sup 99m}Tc-labelling, we have found that synthetic Z{sub HER2:342} conjugated with mercaptoacetyl-glycyl-glycyl-glycyl (maGGG) and mercaptoacetyl-glycyl-seryl-glycyl (maGSG) chelators provides relatively low renal uptake of radioactivity and could be suitable for therapy. maGGG-Z{sub HER2:342} and maGSG-Z{sub HER2:342} were labelled with {sup 186}Re and their biodistribution was studied in normal mice. Dosimetric evaluation and tumour targeting to HER2-overexpressed xenografts (SKOV-3) by {sup 186}Re-maGSG-Z{sub HER2:342} were studied. Gluconate-mediated labelling of maGGG-Z{sub HER2:342} and maGSG-Z{sub HER2:342} with {sup 186}Re provided a yield of more than 95% within 60 min. The conjugates were stable and demonstrated specific binding to HER2-expressing SKOV-3 cells. Biodistribution in normal mice demonstrated rapid blood clearance, low accumulation of radioactivity in the kidney and other organs, accumulating free perrhenate. Both {sup 186}Re-maGGG-Z{sub HER2:342} and {sup 186}Re-maGSG-Z{sub HER2:342} demonstrated lower renal uptake than their {sup 99m}Tc-labelled counterparts. {sup 186}Re-maGSG-Z{sub HER2:342} provided the lowest uptake in healthy tissues. Biodistribution of {sup 186}Re-maGSG-Z{sub HER2:342} in nude mice bearing SKOV-3 xenografts showed specific targeting of tumours. Tumour uptake 24 h after injection (5.84{+-}0.54%ID/g) exceeded the concentration in blood by more than 500-fold, and uptake in kidneys by about 8-fold. Preliminary dosimetric evaluation showed that dose-to-tumour should exceed dose-to-kidney by approximately 5-fold. Optimization of chelators improves biodistribution properties of rhenium-labelled small scaffold proteins and enables

Assessing the psychometric questioner for students rating teachers

Directory of Open Access Journals (Sweden)

Razaghi Reza Sharif

2016-07-01

Full Text Available Educational institutions use different ways to evaluate their teachers. Asking students to rate their teachers is common practice. The purpose of this research was to examine the reliability of the instruments used to evaluate the instructors in a college of medicine. This cross-sectional descriptive research used questioners that evaluated instructors. The questioner was targeting different dimensions of instructors. Item analysis in addition to exploratory factor analysis was performed on 1040questioners answered by the students of the College of Medicine of Kashan University of Medical Sciences. SPSS software was used to perform the analysis. The psychometric properties of questionnaires including Cronbach alpha was determined. The result of exploratory factor analysis and item analysis indicated that three of the subscales of the questioner showed sufficient reliability to evaluate the instructors and two subscales needed further examination. This type of evaluations is necessary to ensure quality of instructors working in an institution as well as providing reliable feedback to the instructors. The result showed that while some subscales of the questioner seems to target the concept of interest; a re-evaluation of the instrument would be valuable to increase its reliability for the administrators in the colleges.

Country Report: Rep. of Korea. {sup 188}re-Tricabonyl Labeling Strategy: Preparation of 1{sup 188}Re(I) Tricarbonyl Precursor [{sup 188}Re(OH{sub 2}){sub 3}(CO){sub 3}]+ for the Labeling of Biomolecules

Energy Technology Data Exchange (ETDEWEB)

Park, Sang Hyun [Radiation Research Division for Biotechnology, Korea Atomic Energy Research Institute (Korea, Republic of)

2010-07-01

The {sup 99m}Tc(I) and {sup 188}Re(I) tricarbonyl precursors [M(OH{sub 2}){sub 3}(CO){sub 3}]{sup +} have been shown to be excellent starting materials for the synthesis of {sup 99m}Tc(I) and {sup 188}Re(I) tricarbonyl complexes as well as radiolabeling of target-specific biomolecules.{sup 1-8} Recently, a user-friendly kit formulation (IsoLink{sup TM}) was developed using potassium boranocarbonate, K{sub 2}[BH{sub 3}CO{sub 2}], for preparation of the {sup 99m}Tc precursor complex. This solid reagent serves both as a source of carbon monoxide and a reducing agent for technetium. It was also used by Schibli and coworkers for the preparation of the corresponding {sup 188}Re precursor complex (“Schibili’s kit”).{sup 9} This approach involved the reduction of [{sup 188}Re]perrhenate eluate (1 ml) in neutral solution with 3 mg K{sub 2}[BH{sub 3}CO{sub 2}] and 5 mg BH3≅NH3 by incubation at 60 °C for 15 min. The amounts of reducing agents and acid (concentrated phosphoric acid) were carefully balanced not only to avoid fast hydrolysis of the boranes, but also to maintain a sufficiently low pH to stabilize reduced rhenium intermediates. The preparations resulted in yields >85 % of the desired precursor complex. In addition, perrhenate (7±3 %), colloidal {sup 188}ReO{sub 2} (<5 %), and a byproduct of unknown composition were also detected. To increase the yields even further, we evaluated the recently described borohydride exchange resin (BER) as an additional reducing agent and an anion scavengers.

Recent progress on RE2O3-Mo/W emission materials.

Science.gov (United States)

Wang, Jinshu; Zhang, Xizhu; Liu, Wei; Cui, Yuntao; Wang, Yiman; Zhou, Meiling

2012-08-01

RE2O3-Mo/W cathodes were prepared by powder metallurgy method. La2O3-Y2O3-Mo cermet cathodes prepared by traditional sintering method and spark plasma sintering (SPS) exhibit different secondary emission properties. The La2O3-Y2O3-Mo cermet cathode prepared by SPS method has smaller grain size and exhibits better secondary emission performance. Monte carlo calculation results indicate that the secondary electron emission way of the cathode correlates with the grain size. Decreasing the grain size can decrease the positive charging effect of RE2O3 and thus is favorable for the escaping of secondary electrons to vacuum. The Scandia doped tungsten matrix dispenser cathode with a sub-micrometer microstructure of matrix with uniformly distributed nanometer-particles of Scandia has good thermionic emission property. Over 100 A/cm2 full space charge limited current density can be obtained at 950Cb. The cathode surface is covered by a Ba-Sc-O active surface layer with nano-particles distributing mainly on growth steps of W grains, leads to the conspicuous emission property of the cathode.

Synthesis of complex compounds in the system [ReOG5]2--thiosemicarbazone acetone-Hg-acetone

International Nuclear Information System (INIS)

Amindzhanov, A.A.; Kurbanov, N.M.

1993-01-01

Present article is devoted to synthesis of complex compounds in the system [ReOG 5 ] 2- -thiosemicarbazone acetone-Hg-acetone. The literature data on complex compounds of various metals with thiosemicarbazone was summarized. The synthesis of complex compounds in the system [ReOG 5 ] 2- -thiosemicarbazone acetone-Hg-acetone was conducted. The complex compounds of rhenium with methyl ident thiosemicarbazone were synthesized.

Catalysts for selective hydrogenation of furfural derived from the double complex salt [Pd(NH 3 ) 4 ](ReO 4 ) 2 on γ-Al 2 O 3

Energy Technology Data Exchange (ETDEWEB)

Thompson, Simon T.; Lamb, H. Henry

2017-06-01

The double complex salt [Pd(NH3)4](ReO4)2 was employed as precursor of supported bimetallic catalysts for selective hydrogenation of furfural. Direct reduction of [Pd(NH3)4](ReO4)2 on γ-Al2O3 in flowing H2 at 400 °C yields bimetallic nanoparticles 1–2 nm in size that exhibit significant interaction between the metals, as evidenced by temperature-programmed hydride decomposition (complete suppression of β-PdHx formation), extended X-ray absorption fine structure spectroscopy at the Pd K and Re LIII edges (PdRe distance = 2.72 Å), and scanning transmission electron microscopy with energy dispersive X-ray analysis. In contrast, calcination of [Pd(NH3)4](ReO4)2 on γ-Al2O3 at 350 °C in air and subsequent reduction in H2 at 400 °C results in metal segregation and formation of large (>50 nm) supported Pd particles; Re species cover the Pd particles and γ-Al2O3 support. A PdRe 1:2 catalyst prepared by sequential impregnation and calcination using HReO4 and [Pd(NH3)4](NO3)2 has a similar morphology. The catalyst derived by direct reduction of [Pd(NH3)4](ReO4)2 on γ-Al2O3 exhibits remarkably high activity for selective hydrogenation of furfural to furfuryl alcohol (FAL) at 150 °C and 1 atm. Suppression of H2 chemisorption via elimination of Pd threefold sites, as evidenced by CO diffuse-reflectance infrared Fourier transform spectroscopy, correlates with increased FAL selectivity.

Charge Density Wave in the New Polymorphs of RE ₂ Ru ₃ Ge ₅ ( RE = Pr, Sm, Dy)

Energy Technology Data Exchange (ETDEWEB)

Bugaris, Daniel E.; Malliakas, Christos D.; Han, Fei; Calta, Nicholas P.; Sturza, Mihai; Krogstad, Matthew J.; Osborn, Raymond; Rosenkranz, Stephan; Ruff, Jacob P. C.; Trimarchi, Giancarlo; Bud’ko, Sergey L.; Balasubramanian, Mahalingam; Chung, Duck Young; Kanatzidis, Mercouri G.

2017-02-16

A new polymorph of the RE₂Ru₃Ge₅ (RE = Pr, Sm, Dy) compounds has been grown as single crystals via an indium flux. These compounds crystallize in tetragonal space group P4/mnc with the Sc₂Fe₃Si₅-type structure, having lattice parameters a = 11.020(2) Å and c = 5.853(1) Å for RE = Pr, a = 10.982(2) Å and c = 5.777(1) Å for RE = Sm, and a = 10.927(2) Å and c = 5.697(1) Å for RE = Dy. These materials exhibit a structural transition at low temperature, which is attributed to an apparent charge density wave (CDW). Both the high-temperature average crystal structure and the low-temperature incommensurately modulated crystal structure (for Sm₂Ru₃Ge₅ as a representative) have been solved. The charge density wave order is manifested by periodic distortions of the onedimensional zigzag Ge chains. From X-ray diffraction, charge transport (electrical resistivity, Hall effect, magnetoresistance), magnetic measurements, and heat capacity, the ordering temperatures (T_CDW) observed in the Pr and Sm analogues are ~200 and ~175 K, respectively. The charge transport measurement results indicate an electronic state transition happening simultaneously with the CDW transition. X-ray absorption near-edge spectroscopy (XANES) and electronic band structure results are also reported.

Les FAQs du tableau de bord - Mythes et réalités du tableau de bord à l'ère de la mondialisation

OpenAIRE

Van Caillie, Didier

2013-01-01

Ce document synthétise en 8 questions clés l'état de notre expérience en matière de conception et d'implémentation d'un tableau de bord dans une organisation, privée ou publique, grande ou petite. Les 8 questions abordées sont : 1. Qu’est-ce qu’un tableau de bord ? 2. Quelle est son utilité pour une organisation à l’ère de la mondialisation ? 3. Quels sont les prérequis à l’utilisation d’un tableau de bord ? 4. Faut-il un tableau de bord unique ou plusieurs tableaux de bord ? 5. Quels indicat...

Large magnetoresistance in (AA')2FeReO6 double perovskites

International Nuclear Information System (INIS)

Teresa, J.M. de; Serrate, D.; Blasco, J.; Ibarra, M.R.; Morellon, L.

2005-01-01

We review the main structural, magnetic and magnetotransport properties of the intriguing (AA') 2 FeReO 6 magnetic double perovskites. As the average cation size decreases, the crystallographic structure at room temperature evolves from cubic [(AA') 2 =Ba 2 , Ba 1.5 Sr 0.5 , BaSr, Ba 0.5 Sr 1.5 ] to tetragonal [(AA') 2 =Sr 2 ] and monoclinic [(AA') 2 =Ca 0.5 Sr 1.5 , CaSr, Ca 1.5 Sr 0.5 , Ca 2 ]. The Curie temperature increases anomalously from ∼303K for Ba 2 to ∼522K for Ca 2 in sharp contrast with the observed behaviour in the isostructural compounds (AA') 2 FeMoO 6 . Other anomalous features in the (AA') 2 FeReO 6 series are: the large magnetic anisotropy, the large magnetoelastic coupling and the semiconducting behaviour of the monoclinic compounds. The monoclinic compounds undergo a structural/magnetic transition at T S below 125K. Three different magnetoresistance mechanisms have been identified: the intergrain negative magnetoresistance effect, which is present across the whole series of compounds, and in the case of the monoclinic compounds below T S a negative magnetoresistance effect associated to the melting of the low-temperature phase and a positive magnetoresistance effect only present in (AA') 2 =Ca 2 below T∼50K

Interface engineered HfO2-based 3D vertical ReRAM

International Nuclear Information System (INIS)

Hudec, Boris; Wang, I-Ting; Lai, Wei-Li; Chang, Che-Chia; Hou, Tuo-Hung; Jančovič, Peter; Fröhlich, Karol; Mičušík, Matej; Omastová, Mária

2016-01-01

We demonstrate a double-layer 3D vertical resistive random access memory (ReRAM) stack implementing a Pt/HfO 2 /TiN memory cell. The HfO 2 switching layer is grown by atomic layer deposition on the sidewall of a SiO 2 /TiN/SiO 2 /TiN/SiO 2 multilayer pillar. A steep vertical profile was achieved using CMOS-compatible TiN dry etching. We employ in situ TiN bottom interface engineering by ozone, which results in (a) significant forming voltage reduction which allows for forming-free operation in AC pulsed mode, and (b) non-linearity tuning of low resistance state by current compliance during Set operation. The vertical ReRAM shows excellent read and write disturb immunity between vertically stacked cells, retention over 10 4 s and excellent switching stability at 400 K. Endurance of 10 7 write cycles was achieved using 100 ns wide AC pulses while fast switching speed using pulses of only 10 ns width is also demonstrated. The active switching region was evaluated to be located closer to the bottom interface which allows for the observed high endurance. (paper)

Standard Molar Enthalpy of Formation of RE(C5H8NS2)3(C12H8N2)

Institute of Scientific and Technical Information of China (English)

Meng Xiangxin; Shuai Qi; Chen Sanping; Xie Gang; Gao Shengli; Shi Qizhen

2005-01-01

Four solid ternary complexes of RE (C5H8NS2)3(C12H8N2) (RE=Eu, Gd, Tb, Dy) were synthesized in absolute ethanol by rare earth chloride low hydrate with the mixed ligands of ammonium pyrrolidinedi-thiocarbamate (APDC) and 1, 10-phenanthroline*H2O (o-phen*H2O) in the ordinary laboratory atmosphere without any cautions against moisture or air sensitivity. IR spectra of the complexes show that the RE3+ coordinated with six sulfur atoms of three PDC- and two nitrogen atoms of o-phen*H2O. It was assumed that the coordination number of RE3+ is eight. The constant-volume combustion energies of the complexes, ΔcU, were determined as (-16937.88±9.79 ), (-17588.79±8.62 ), (-17747.14±8.25 ) and (-17840.37±8.87 ) kJ*mol-1, by a precise rotating-bomb calorimeter at 298.15 K. Its standard molar enthalpies of combustion, ΔcHθm, and standard molar enthalpies of formation, ΔfHθm, were calculated as (-16953.37±9.79), (-17604.28±8.62), (-17762.63±8.25), (-17855.86±8.87) kJ*mol-1 and (-857.04±10.52), (-282.43±9.58), (-130.08±9.13), (-55.75±9.83) kJ*mol-1.

Spin-glass behavior in the S=1/2 fcc ordered perovskite Sr2CaReO6

International Nuclear Information System (INIS)

Wiebe, C.R.; Greedan, J.E.; Luke, G.M.; Gardner, J.S.

2002-01-01

The ordered perovskite Sr 2 CaReO 6 of monoclinic symmetry [space group P2 1 /n,a=5.7556(3) A,b=5.8534(3) A,c=8.1317(4) A,β=90.276(5) deg. at T=4 K] has been synthesized using standard solid-state chemistry techniques. The difference in the size and charge of the cations induces an ordering of the B site Ca 2+ and Re 6+ ions which leads to a distorted fcc lattice of spin-(1/2) Re 6+ (5d 1 ) moments. dc magnetic susceptibility measurements indicate a maximum at T G ∼14 K and an irreversibility in the field-cooled and zero-field-cooled data at ∼22 K that is believed to be caused by the geometric frustration inherent in the fcc structure. Neutron-scattering measurements confirm the absence of magnetic long-range order, and muon spin relaxation experiments indicate the presence of an abrupt spin freezing at T G . Specific heat measurements reveal a broad anomaly typical of spin glasses and no sharp feature. 65% of the spin entropy is released at low temperatures. The low-temperature data do not show the expected linear temperature dependence, but rather a T 3 relationship, as is observed, typically, for antiferromagnetic spin waves. The material is characterized as an unconventional, essentially disorder-free, spin glass

41 CFR 300-2.20 - What is the purpose of the question & answer format?

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false What is the purpose of the question & answer format? 300-2.20 Section 300-2.20 Public Contracts and Property Management Federal Travel Regulation System GENERAL INTRODUCTION 2-HOW TO USE THE FTR Question & Answer Format § 300...

Phosphide oxides RE2AuP2O (RE = La, Ce, Pr, Nd): synthesis, structure, chemical bonding, magnetism, and 31P and 139La solid state NMR.

Science.gov (United States)

Bartsch, Timo; Wiegand, Thomas; Ren, Jinjun; Eckert, Hellmut; Johrendt, Dirk; Niehaus, Oliver; Eul, Matthias; Pöttgen, Rainer

2013-02-18

Polycrystalline samples of the phosphide oxides RE(2)AuP(2)O (RE = La, Ce, Pr, Nd) were obtained from mixtures of the rare earth elements, binary rare earth oxides, gold powder, and red phosphorus in sealed silica tubes. Small single crystals were grown in NaCl/KCl fluxes. The samples were studied by powder X-ray diffraction, and the structures were refined from single crystal diffractometer data: La(2)AuP(2)O type, space group C2/m, a = 1515.2(4), b = 424.63(8), c = 999.2(2) pm, β = 130.90(2)°, wR2 = 0.0410, 1050 F(2) values for Ce(2)AuP(2)O, and a = 1503.6(4), b = 422.77(8), c = 993.0(2) pm, β = 130.88(2)°, wR2 = 0.0401, 1037 F(2) values for Pr(2)AuP(2)O, and a = 1501.87(5), b = 420.85(5), c = 990.3(3) pm, β = 131.12(1)°, wR2 = 0.0944, 1143 F(2) values for Nd(2)AuP(2)O with 38 variables per refinement. The structures are composed of [RE(2)O](4+) polycationic chains of cis-edge-sharing ORE(4/2) tetrahedra and polyanionic strands [AuP(2)](4-), which contain gold in almost trigonal-planar phosphorus coordination by P(3-) and P(2)(4-) entities. The isolated phosphorus atoms and the P(2) pairs in La(2)AuP(2)O could clearly be distinguished by (31)P solid state NMR spectroscopy and assigned on the basis of a double quantum NMR technique. Also, the two crystallographically inequivalent La sites could be distinguished by static (139)La NMR in conjunction with theoretical electric field gradient calculations. Temperature-dependent magnetic susceptibility measurements show diamagnetic behavior for La(2)AuP(2)O. Ce(2)AuP(2)O and Pr(2)AuP(2)O are Curie-Weiss paramagnets with experimental magnetic moments of 2.35 and 3.48 μ(B) per rare earth atom, respectively. Their solid state (31)P MAS NMR spectra are strongly influenced by paramagnetic interactions. Ce(2)AuP(2)O orders antiferromagnetically at 13.1(5) K and shows a metamagnetic transition at 11.5 kOe. Pr(2)AuP(2)O orders ferromagnetically at 7.0 K.

Magnetic, electrical and structural properties of the Re-doped ruthenocuprate Ru1−xRexSr2GdCu2Oy

International Nuclear Information System (INIS)

Corredor, L.T.; Albino Aguiar, J.; Landínez Téllez, D.A.; Pureur, P.; Mesquita, F.; Roa-Rojas, J.

2015-01-01

Highlights: • We investigated the effect of the dilution of magnetic Ru sub-lattice of RuSr 2 GdCu 2 O 8 . • We synthesized the doped compound Rui x Re x Sr 2 GdCu 2 O y , for 3%, 6%, 9% and 12% Re. • Re would affect the electron coupling: just 3 and 6% samples were superconductor. • Superconductivity emergence strongly affects magnetic properties of 3 and 6% samples. • A weak ferromagnetic component is consistent with a globally antiferromagnetic system. - Abstract: Despite the discovery of new superconductors classes, high-Tc oxides continue to be a current topic, because of their complex phase diagrams and doping-dependant effects (allowing one to investigate the interaction between orbitals), as well as structural properties such as lattice distortion and charge ordering, among many others. Ruthenocuprates are magnetic superconductors in which the magnetic transition temperature is much higher than the critical superconducting temperature, making them unique compounds. With the aim of investigating the dilution of the magnetic Ru sub-lattice, we proposed the synthesis of the Ru 1−x Re x Sr 2 GdCu 2 O y ruthenocuprate-type family, adapting the known two-step process (double perovskite + CuO) by directly doping the double perovskite, thus obtaining the perovskite compound Sr 2 GdRu 1−x Re x O y , which represents a new synthesis process to the best of our knowledge. Our samples were structurally characterized through X-ray diffraction, and the patterns were analysed via Rietveld refinement. A complete magnetic characterization as a function of temperature and applied field, as well as transport measurements were carried out. We discuss our results in the light of the two-lattice model for ruthenocuprates, and a relation between RuO 2 (magnetic) and CuO 2 (superconductor) sub-lattices can clearly be observed

Questioning the Questions

Science.gov (United States)

Tienken, Christopher H.; Goldberg, Stephanie; DiRocco, Dominic

2010-01-01

Historical accounts of questioning used in the education process trace back to Socrates. One of the best examples of his use of questioning is found in Plato's "The Republic." Socrates used a series of strategic questions to help his student Glaucon come to understand the concept of justice. Socrates purposefully posed a series of…

Structural phase transition and magnetic properties of double perovskites Ba2CaMO6 (M=W, Re, Os)

International Nuclear Information System (INIS)

Yamamura, Kazuhiro; Wakeshima, Makoto; Hinatsu, Yukio

2006-01-01

Structures and magnetic properties for double perovskites Ba 2 CaMO 6 (M=W, Re, Os) were investigated. Both Ba 2 CaReO 6 and Ba 2 CaWO 6 show structural phase transitions at low temperatures. For Ba 2 CaReO 6 , the second order transition from cubic Fm3-bar m to tetragonal I4/m has been observed near 120K. For Ba 2 CaWO 6 , the space group of the crystal structure is I4/m at 295K and the transition to monoclinic I2/m has been observed between 220K. Magnetic susceptibility measurements show that Ba 2 CaReO 6 (S=1/2) and Ba 2 CaOsO 6 (S=1) transform to an antiferromagnetic state below 15.4 and 51K, respectively. Anomalies corresponding to their structural phase transition and magnetic transition have been also observed through specific heat measurements

Role of Re in Pt-Re/TiO2 catalyst for water gas shift reaction: A mechanistic and kinetic study.

NARCIS (Netherlands)

Azzam, K.G.H.; Babych, Igor V.; Seshan, Kulathuiyer; Lefferts, Leonardus

2008-01-01

Transient kinetic studies and in situ FTIR spectroscopy were used to follow the reaction sequences that occur during water gas shift (WGS) reaction over Pt–Re/TiO2 catalyst. Results pointed to contributions of an associative formate route with redox regeneration and two classical redox routes

Syntaxe et sémantique chez Tesnière

Directory of Open Access Journals (Sweden)

Paul Garde

1994-12-01

Full Text Available Ce qui frappe avant tout dans les Eléments de syntaxe structurale de Lucien Tesnière, c'est leur caractère exhaustif: il s'agit d' une somme, rendant compte potentiellement de tous les phénomènes syntaxiques de toutes les langues. Aucun des autres grands linguistes du XX0 siècle ne nous presénte une oeuvre comparable, tous, de Hjelmslev à Chomsky, insistent davantage sur des questions de méthode sans en rechercher l’application à tous les problèmes possibles.

Addressing challenges to MMPI-2-RF-based testimony: questions and answers.

Science.gov (United States)

Ben-Porath, Yossef S

2012-11-01

Introduction of a new version of a psychological test brings with it challenges that can be accentuated by the adversarial nature of the legal process. In the case of the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF), these challenges can be addressed by becoming familiar with the rationale for and the methods used in revising the inventory, the information contained in the test manuals, and the growing peer-reviewed literature on the test. Potential challenges to MMPI-2-RF-based testimony are identified in this article and discussed in question and answer format. The questions guiding this discussion are based on the Daubert factors, established in 1993 by the US Supreme Court as criteria for gauging the scientific validity of proffered expert testimony. The answers to these questions apply more broadly to testimony in depositions, pre-trial hearings, and at trial. Consideration of the MMPI-2-RF in light of the Daubert factors indicates that the instrument has been subjected to extensive empirical testing and that a substantial peer-reviewed literature is available to guide and support its use. Information about the known and potential rate of error associated with MMPI-2-RF scores is available, and standard procedures for administration, scoring, and interpretation of the inventory are detailed in the test administration manual. Indicators of MMPI-2-RF acceptance can be cited, and criticisms of the MMPI-2-RF can be addressed with information available in the test documents and an extensive, modern, and actively growing peer-reviewed literature.

Evaluating the role of re-adsorption of dissolved Hg{sup 2+} during cinnabar dissolution using isotope tracer technique

Energy Technology Data Exchange (ETDEWEB)

Jiang, Ping [Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199 (United States); Li, Yanbin [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education/Qingdao Collaborative Innovation Center of Marine Science and Technology, Ocean University of China, Qingdao 266100 (China); Liu, Guangliang [Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199 (United States); Southeast Environmental Research Center, Florida International University, Miami, FL 33199 (United States); Yang, Guidi [College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002 (China); Lagos, Leonel [Applied Research Center, Florida International University, Miami, FL 33199 (United States); Yin, Yongguang [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Gu, Baohua [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge TN 37831 (United States); Jiang, Guibin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Cai, Yong, E-mail: cai@fiu.edu [Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199 (United States); Southeast Environmental Research Center, Florida International University, Miami, FL 33199 (United States)

2016-11-05

Highlights: • Develop a new method to study Hg re-adsorption in cinnabar. • Both isotope dilution and tracer techniques were adopted. • The presence of O{sub 2} can significantly enhance the dissolution of cinnabar. • Prove the necessity of including re-adsorption in estimating cinnabar dissolution. - Abstract: Cinnabar dissolution is an important factor controlling mercury (Hg) cycling. Recent studies have suggested the co-occurrence of re-adsorption of the released Hg during the course of cinnabar dissolution. However, there is a lack of feasible techniques that can quantitatively assess the amount of Hg re-adsorbed on cinnabar when investigating cinnabar dissolution. In this study, a new method, based on isotope tracing and dilution techniques, was developed to study the role of Hg re-adsorption in cinnabar dissolution. The developed method includes two key components: (1) accurate measurement of both released and spiked Hg in aqueous phase and (2) estimation of re-adsorbed Hg on cinnabar surface via the reduction in spiked {sup 202}Hg{sup 2+}. By adopting the developed method, it was found that the released Hg for trials purged with oxygen could reach several hundred μg L{sup −1}, while no significant cinnabar dissolution was detected under anaerobic condition. Cinnabar dissolution rate when considering Hg re-adsorption was approximately 2 times the value calculated solely with the Hg detected in the aqueous phase. These results suggest that ignoring the Hg re-adsorption process can significantly underestimate the importance of cinnabar dissolution, highlighting the necessity of applying the developed method in future cinnabar dissolution studies.

Dehydriding and re-hydriding properties of high-energy ball milled LiBH{sub 4}+MgH{sub 2} mixtures

Energy Technology Data Exchange (ETDEWEB)

Crosby, Kyle; Shaw, Leon L. [Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, 97 North Eagleville Road, U-3136, Storrs, CT 06269 (United States)

2010-07-15

Here we report the first investigation of the dehydriding and re-hydriding properties of 2LiBH{sub 4} + MgH{sub 2} mixtures in the solid state. Such a study is made possible by high-energy ball milling of 2LiBH{sub 4}+MgH{sub 2} mixtures at liquid nitrogen temperature with the addition of graphite. The 2LiBH{sub 4}+MgH{sub 2} mixture ball milled under this condition exhibits a 5-fold increase in the released hydrogen at 265 C when compared with ineffectively ball milled counterparts. Furthermore, both LiBH{sub 4} and MgH{sub 2} contribute to hydrogen release in the solid state. The isothermal dehydriding/re-hydriding cycles at 265 C reveal that re-hydriding is dominated by re-hydriding of Mg. These unusual phenomena are explained based on the formation of nanocrystalline and amorphous phases, the increased defect concentration in crystalline compounds, and possible catalytic effects of Mg,MgH{sub 2} and LiBH{sub 4} on their dehydriding and re-hydriding properties. (author)

Giant magnetostriction in Ca2FeReO6 double perovskite

International Nuclear Information System (INIS)

Serrate, D.; De Teresa, J.M.; Algarabel, P.A.; Marquina, C.; Morellon, L.; Blasco, J.; Ibarra, M.R.

2005-01-01

We report magnetostriction measurements in polycrystalline Ca 2 FeReO 6 magnetic double perovskite up to 20T and in the temperature range 4.2-250K. This compound shows a high Curie temperature (T C =523K) and a structural transition at low temperatures (T S =110K). By combining magnetostriction measurements parallel and perpendicular to the magnetic field, we evaluate the anisotropic (λ t ) and volume magnetostriction (ω). The λ t at room temperature is large and reaches below T S the giant value of ∼0.1% at 15T. Below T S , the ω is also found to be large: ∼0.05% at 15T at 5K. These results are interpreted within a scenario where the Re orbital state plays a crucial role in the ground state. The observed effect could open a new way to observe giant magnetostriction effects in transition-metal-based magnetic oxides through suitable tuning of the orbital effects in the transition metals

Questions from Afar: The Influence of Outsideness on Web-Based Conversation

Science.gov (United States)

Deed, Craig; Edwards, Anthony; Gomez, Viviana

2015-01-01

This paper defines the metaphor of outsideness in relation to web-based interaction. Outsideness is conceived of as a key influence in online academic conversation. In particular, through the sharing of cultural perspectives, asking questions to resolve doubt, and collaborative writing and re-writing as a basis for shaping ideas through reasoning.…

In situ X-ray and neutron diffraction of the Ruddlesden-Popper compounds (RE2-xSrx)0.98(Fe0.8Co0.2)1-yMgyO4-δ (RE=La, Pr): Structure and CO2 stability

DEFF Research Database (Denmark)

Chatzichristodoulou, Christodoulos; Hauback, B.C.; Hendriksen, Peter Vang

2013-01-01

The crystal structure of the Ruddlesden-Popper compounds (La 1.0Sr1.0)0.98Fe0.8Co 0.2O4-δ and (La1.2Sr0.8) 0.98(Fe0.8Co0.2)0.8Mg 0.2O4-δ was investigated at 1000 °C in N 2 (aO2=1×10-4) by in-situ powder neutron diffraction. In-situ powder X-ray diffraction (PXD) was also employed to investigate....... The equivalent pseudo-cubic thermal and chemical expansion coefficients are in agreement with values determined by dilatometry. The chemical stability in CO2 containing environments of various Ruddlesden-Popper compounds with chemical formula (RE2-xSr x)0.98(Fe0.8Co0.2) 1-yMgyO4-δ (RE=La, Pr), as well...

Nature of the tensor order in Cd2Re2O7

Science.gov (United States)

Di Matteo, S.; Norman, M. R.

2017-09-01

The pyrochlore metal Cd2Re2O7 has been recently investigated by second-harmonic generation (SHG) reflectivity. In this paper, we develop a general formalism that allows for the identification of the relevant tensor components of the SHG from azimuthal scans. We demonstrate that the secondary order parameter identified by SHG at the structural phase transition is the x2-y2 component of the axial toroidal quadrupole. This differs from the 3 z2-r2 symmetry of the atomic displacements associated with the I 4 ¯m 2 crystal structure that was previously thought to be its origin. Within the same formalism, we suggest that the primary order parameter detected in the SHG experiment is the 3 z2-r2 component of the magnetic quadrupole. We discuss the general mechanism driving the phase transition in our proposed framework, and suggest experiments, particularly resonant x-ray scattering ones, that could clarify this issue.

Magnesium-rich intermetallics RE3RuMg7 (RE = Y, Nd, Dy, Ho). Rows of condensed Ru rate at RE6/2 octahedra in magnesium matrices

International Nuclear Information System (INIS)

Kersting, Marcel; Rodewald, Ute C.; Schwickert, Christian; Poettgen, Rainer

2013-01-01

The magnesium-rich intermetallic phases RE 3 RuMg 7 (RE = Y, Nd, Dy, Ho) have been synthesized from the elements in sealed niobium ampoules and subsequently characterized by powder X-ray diffraction. The structure of the dysprosium compound was refined on the basis of single-crystal X-ray diffractometer data: Ti 6 Sn 5 type, P6 3 /mmc, a = 1019.1(2), c = 606.76(9) pm, wR2 = 0.0159, 439 F 2 values, 19 variables. The Mg3 site shows a small degree of Mg3/Dy mixing, leading to the composition Dy 3.03 RuMg 6.97 for the investigated crystal. The striking structural motifs in the Dy 3 RuMg 7 structure are rows of face-sharing Ru rate at Dy 6 octahedra and corner-sharing Mg2 rate at Mg 8 Dy 4 icosahedra. The rows of octahedra form a hexagonal rod-packing, and each rod is enrolled by six rows of the condensed icosahedra. Temperature-dependent magnetic susceptibility measurements of Dy 3 RuMg 7 show Curie-Weiss behavior with an experimental magnetic moment of 10.66(1) μ B per Dy atom. Antiferromagnetic ordering is detected at T N = 27.5(5) K. The 5 K isotherm shows a metamagnetic transition at a critical field of H C = 40 kOe. (orig.)

Seismic re-evaluation of the Tarapur atomic power plants 1 and 2

International Nuclear Information System (INIS)

Ingole, S.M.; Kumar, B.S.; Gupta, S.; Singh, U.P.; Giridhar, K.; Bhawsar, S.D.; Samota, A.; Chhatre, A.G.; Dixit, K.B.; Bhardwaj, S.A.

2004-01-01

Two Boiling Water Reactors (BWR) of 210 MWe each at Tarapur Atomic Power Station, Units-1 and 2 (TAPS-1-2) were commissioned in the year 1969. The safety related civil structures at TAPS had been designed for a seismic coefficient of 0.2 g and other structures for 0.1 g. The work of seismic re-evaluation of the TAPS-1-2 has been taken up in the year 2002. As two new Pressurized Heavy Water Reactor (PHWR) plants of 540 MWe each, Tarapur Atomic Power Project Units-3 and 4 (TAPP-3-4), are coming up in the vicinity of TAPS-1-2, detailed geological and seismological studies of the area around TAPS-1-2 are available. The same free-field ground motion as generated for TAPP-3-4 has been used for TAPS-1-2. The seismic re-evaluation of the plant has been performed as per the procedure given in IAEA, Safety Reports Series entitled 'Seismic Evaluation of Existing Nuclear Power Plants', and meeting the various codes and standards, viz., ASME, ASCE, IEEE standards etc. The Safety Systems (SS) and Safety Support Systems (SSS) are qualified by adopting detailed analysis and testing methods. The equipment in the SS and SSS have been qualified by conducting a walk-down as per the procedure given in Generic Implementation Procedure, Dept. of Energy (GIP--DOE), USA. The safety systems include the systems required for safe shutdown of the plant, one chain of decay heat removal and containment of activity. The safety support systems viz., Electrical, Instrumentation and Control and systems other than SS and SSS have been qualified by limited analysis, testing and mostly by following the procedure of walk-down. The paper brings out the details of the work accomplished during seismic re-evaluation of the two units of BWR at Tarapur. (authors)

Rare earth-rich cadmium compounds RE{sub 10}TCd{sub 3} (RE = Y, Tb, Dy, Ho, Er, Tm, Lu; T = Rh, Pd, Ir, Pt) with an ordered Co{sub 2}Al{sub 5}-type structure

Energy Technology Data Exchange (ETDEWEB)

Block, Theresa; Klenner, Steffen; Heletta, Lukas; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie

2018-04-01

Eighteen new rare earth-rich intermetallic phases RE{sub 10}TCd{sub 3} (RE = Y, Tb, Dy, Ho, Er, Tm, Lu; T = Rh, Pd, Ir, Pt) were obtained by induction melting of the elements in sealed niobium ampoules followed by annealing in muffle furnaces. All samples were characterized by X-ray powder diffraction. The structures of four representatives were refined from single-crystal X-ray diffractometer data: ordered Co{sub 2}Al{sub 5} type, P6{sub 3}/mmc, a = 951.2(1), c = 962.9(2) pm, wR = 0.0460, 595 F{sup 2} values, 20 parameters for Er{sub 10}RhCd{sub 3}; a = 945.17(4), c = 943.33(4), wR = 0.0395, 582 F{sup 2} values, 21 parameters for Lu{sub 9.89}PdCd{sub 3.11}; a = 964.16(6), c = 974.93(6) pm, wR = 0.0463, 614 F{sup 2} values, 21 parameters for Y{sub 10}Ir{sub 1.09}Cd{sub 2.91}; a = 955.33(3), c = 974.56(3) pm, wR = 0.0508, 607 F{sup 2} values, 22 refined parameters for Dy{sub 9.92}IrCd{sub 3.08}. Refinements of the occupancy parameters revealed small homogeneity ranges resulting from RE/Cd, respectively T/Cd mixing. The basic building units of the RE{sub 10}TCd{sub 3} phases are transition metal-centered RE{sub 6} trigonal prisms (TP) that are condensed with double-pairs of empty RE{sub 6} octahedra via common triangular faces. A second type of rods is formed by slightly distorted RE3 rate at Cd{sub 6}RE{sub 6} icosahedra which are condensed via Cd{sub 3} triangular faces. The shortest interatomic distances occur for RE-T, compatible with strong covalent bonding interactions. Temperature dependent magnetic susceptibility measurements were performed for RE{sub 10}RhCd{sub 3} (RE = Dy-Tm, Lu), RE{sub 10}IrCd{sub 3} (RE = Er, Tm, Lu) and RE{sub 10}PtCd{sub 3} (RE = Y, Lu). While Y{sub 10}PtCd{sub 3} and Lu{sub 10}TCd{sub 3} (T = Rh, Ir, Pt) show Pauli paramagnetic behavior, the compounds containing paramagnetic rare earth elements show Curie-Weiss behavior (the experimental magnetic moments indicate stable trivalent RE{sup 3+}) and magnetic ordering at low temperatures

Evaluating the role of re-adsorption of dissolved Hg(2+) during cinnabar dissolution using isotope tracer technique.

Science.gov (United States)

Jiang, Ping; Li, Yanbin; Liu, Guangliang; Yang, Guidi; Lagos, Leonel; Yin, Yongguang; Gu, Baohua; Jiang, Guibin; Cai, Yong

2016-11-05

Cinnabar dissolution is an important factor controlling mercury (Hg) cycling. Recent studies have suggested the co-occurrence of re-adsorption of the released Hg during the course of cinnabar dissolution. However, there is a lack of feasible techniques that can quantitatively assess the amount of Hg re-adsorbed on cinnabar when investigating cinnabar dissolution. In this study, a new method, based on isotope tracing and dilution techniques, was developed to study the role of Hg re-adsorption in cinnabar dissolution. The developed method includes two key components: (1) accurate measurement of both released and spiked Hg in aqueous phase and (2) estimation of re-adsorbed Hg on cinnabar surface via the reduction in spiked (202)Hg(2+). By adopting the developed method, it was found that the released Hg for trials purged with oxygen could reach several hundred μgL(-1), while no significant cinnabar dissolution was detected under anaerobic condition. Cinnabar dissolution rate when considering Hg re-adsorption was approximately 2 times the value calculated solely with the Hg detected in the aqueous phase. These results suggest that ignoring the Hg re-adsorption process can significantly underestimate the importance of cinnabar dissolution, highlighting the necessity of applying the developed method in future cinnabar dissolution studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Temperature-dependent Raman spectroscopy studies of the interface coupling effect of monolayer ReSe2 single crystals on Au foils

Science.gov (United States)

Jiang, Shaolong; Zhao, Liyun; Shi, Yuping; Xie, Chunyu; Zhang, Na; Zhang, Zhepeng; Huan, Yahuan; Yang, Pengfei; Hong, Min; Zhou, Xiebo; Shi, Jianping; Zhang, Qing; Zhang, Yanfeng

2018-05-01

Rhenium diselenide (ReSe2), which bears in-plane anisotropic optical and electrical properties, is of considerable interest for its excellent applications in novel devices, such as polarization-sensitive photodetectors and integrated polarization-controllers. However, great challenges to date in the controllable synthesis of high-quality ReSe2 have hindered its in-depth investigations and practical applications. Herein, we report a feasible synthesis of monolayer single-crystal ReSe2 flakes on the Au foil substrate by using a chemical vapor deposition route. Particularly, we focus on the temperature-dependent Raman spectroscopy investigations of monolayer ReSe2 grown on Au foils, which present concurrent red shifts of Eg-like and Ag-like modes with increasing measurement temperature from 77–290 K. Linear temperature dependences of both modes are revealed and explained from the anharmonic vibration of the ReSe2 lattice. More importantly, the strong interaction of ReSe2 with Au, with respect to that with SiO2/Si, is further confirmed by temperature-dependent Raman characterization. This work is thus proposed to shed light on the optical and thermal properties of such anisotropic two-dimensional three-atom-thick materials.

Synthesis and luminescence properties of ZnAl{sub 2}O{sub 4}:RE{sup 3+} (RE = Eu, Sm) phosphors

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Jin; Cho, Shin Ho [Silla University, Busan (Korea, Republic of)

2014-01-15

ZnAl{sub 2}O{sub 4}:RE{sup 3+} (RE = Eu or Sm) phosphor powders were synthesized with different concentrations of activator ions by using the conventional solid-state reaction method. The effects of the concentration of activator ions on the structural, morphological, and luminescent properties of zinc aluminate phosphors were investigated. The X-ray diffraction patterns revealed that the phosphors synthesized with different concentrations of activator ions showed mixed phases of ZnAl{sub 2}O{sub 4}, ZnO, and Al{sub 2}O{sub 3}. The crystallite size was estimated using the Scherrer formula, and the maximum size was obtained for 0.20 mol of Eu{sup 3+} ions. The emission spectra of of Eu{sup 3+}-doped ZnAl{sub 2}O{sub 4} phosphors under excitation at 303 nm exhibited one intense green band at approximately 520 nm and three weak bands centered at 590, 621, and 701 nm, respectively. The intensity of all the emission bands reached a maximum for 0.05 mol of Eu{sup 3+} ions. For the Sm{sup 3+}-doped ZnAl{sub 2}O{sub 4} phosphors, a broad emission band peak at 526 nm and several weak lines in the range 470 - 700 nm were observed. The results suggest that the luminescent intensity of the phosphors can be enhanced by controlling the amount of activator ions incorporated into the host lattice.

Late Pliocene carnivores from Včeláre 2 (Southeastern Slovakia)

Czech Academy of Sciences Publication Activity Database

Sabol, M.; Holec, P.; Wagner, Jan

2008-01-01

Roč. 42, č. 5 (2008), s. 531-543 ISSN 0031-0301 Institutional research plan: CEZ:AV0Z30130516 Keywords : Homotherium * Ursus * Parailurus * Včeláre 2 (Slovakia) Subject RIV: EG - Zoology Impact factor: 0.369, year: 2008

Low-temperature heat capacity and thermodynamic properties of [Re2(Ile)4(H2O)8](ClO4)6 (Re=Nd, Er, Ile=isoleucine)

International Nuclear Information System (INIS)

Lan Xiaozheng; Tan Zhicheng; Liu Beiping; Nan Zhaodong; Sun Lixian; Xu Fen

2003-01-01

The heat capacities of two kinds of rare-earth element solid complexes with isoleucine [Re 2 (Ile) 4 (H 2 O) 8 ](ClO 4 ) 6 (where Re=Nd, Er, and Ile=isoleucine) have been measured by an automatic adiabatic calorimeter in the temperature range from 80 to 370 K. Two solid-solid phase transitions were found from the C p curve of Nd formed complex in the range of 165-175 K with a peak temperature of 167.88 K and in the range of 195-210 K with a peak temperature of 202.13 K. The corresponding molar enthalpies of these phase transitions were determined to be 404.61 J mol -1 and 2.955 kJ mol -1 , respectively. One solid-solid phase transition was found for the Er formed complex in the range of 190-205 K with a peak temperature of 193.42 K. The corresponding molar enthalpy of this transition was 14.11 kJ mol -1 . Smooth heat capacities and thermodynamic functions relative to the standard state (298.15 K), H T -H 298.15 , S T -S 298.15 and -[G T -G 298.15 ], of the two compounds, were calculated on basis of experimental heat capacity data. Possible mechanisms of thermal decompositions for the pair of compounds were suggested according to the thermogravimetric (TG) analysis

Production of {sup 186}Re and {sup 188}Re, and synthesis of {sup 188}Re-DTPA

Energy Technology Data Exchange (ETDEWEB)

Hashimoto, Kazuyuki; Motoishi, Shoji; Kobayashi, Katsutoshi; Izumo, Mishiroku [Department of Radioisotopes, Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan); Musdja, Muhammad Yanis

1999-08-01

Production of radioactive rhenium isotopes {sup 186}Re and {sup 188}Re, and synthesis of {sup 188}Re-DTPA have been studied. For {sup 186}Re, a production method by the {sup 185}Re(n, {gamma}) {sup 186}Re reaction in a reactor has been established. For {sup 188}Re, a production method by the double neuron capture reaction of {sup 186}W, which produces a {sup 188}W/{sup 188}Re generator, has been established. For synthesis of {sup 188}Re-DTPA, the optimum conditions, including pH, the amounts of regents and so on, have been determined. (author)

Comparative NMR investigation of the Re-based borides

Science.gov (United States)

Lue, C. S.; Tao, Y. F.; Su, T. H.

2008-07-01

We report a systematic study of the rhenium-based borides, ReB2 , Re7B3 , and Re3B , by means of the B11 nuclear magnetic resonance (NMR) spectroscopy. While Re7B3 and Re3B are superconductors, ReB2 exhibits no superconducting signature but is of current interest due to its superhard mechanical property. Since the major focus of this investigation is their electronic characteristics in the normal states, we performed the measurements at temperatures between 77 and 295 K. For Re7B3 and Re3B , s -character electrons were found to be responsible for the observed B11 NMR Knight shift and spin-lattice relaxation rate (1/T1) . From T1 analysis, we thus deduce the partial Bs Fermi-level density of states (DOS) of both borides. On the other hand, the relaxation rate of ReB2 is mainly associated with p electrons, similar to the cases of OsB2 and RuB2 . In addition, the extracted B2p Fermi-level DOS is in good agreement with the theoretical prediction from band-structure calculations.

Re-telling, Re-evaluating and Re-constructing

Directory of Open Access Journals (Sweden)

Gorana Tolja

2013-11-01

Full Text Available 'Graphic History: Essays on Graphic Novels and/as History '(2012 is a collection of 14 unique essays, edited by scholar Richard Iadonisi, that explores a variety of complex issues within the graphic novel medium as a means of historical narration. The essays address the issues of accuracy of re-counting history, history as re-constructed, and the ethics surrounding historical narration.

Usage-based vs. rule-based learning: the acquisition of word order in wh-questions in English and Norwegian.

Science.gov (United States)

Westergaard, Marit

2009-11-01

This paper discusses different approaches to language acquisition in relation to children's acquisition of word order in wh-questions in English and Norwegian. While generative models assert that children set major word order parameters and thus acquire a rule of subject-auxiliary inversion or generalized verb second (V2) at an early stage, some constructivist work argues that English-speaking children are simply reproducing frequent wh-word+auxiliary combinations in the input. The paper questions both approaches, re-evaluates some previous work, and provides some further data, concluding that the acquisition of wh-questions must be the result of a rule-based process. Based on variation in adult grammars, a cue-based model to language acquisition is presented, according to which children are sensitive to minor cues in the input, called micro-cues. V2 is not considered to be one major parameter, but several smaller-scale cues, which are responsible for children's lack of syntactic (over-)generalization in the acquisition process.

La vitesse de la lumière et les neutrinos 50 questions/réponses pour mieux comprendre

CERN Document Server

Vannucci, François

2012-01-01

La vitesse de la lumière est une constante de la physique. Sa valeur définit une limite infranchissable, le fameux c valant 300 000 km/s. Or une expérience appelée OPERA, située près de Rome, a déclaré avoir observé des neutrinos, produits au CERN de Genève, atteignant une vitesse supérieure. La nouvelle a été largement relayée par les médias. L'orthodoxie semble aujourd'hui rétablie, mais il est intéressant de revisiter ce résultat pour en comprendre les enjeux. Mais au juste, les neutrinos, c'est quoi ? Qu'est-ce que le CERN ? Que veut dire OPERA ? Pourquoi sous une montagne ? Comment mesure-t-on une vitesse ? Est-ce la première mesure du genre ? Pourquoi la communauté est-elle en ébullition ? D'où vient la vitesse de la lumière ? Qu'est-ce que la relativité restreinte ? La causalité est-elle violée ? Les corrections sont-elles bien calculées ? Des dimensions supplémentaires existent-elles ? Pourquoi tout ce battage médiatique ? Les réponses connues à ce jour sont discutées d...

Hexagonal perovskites with cationic vacancies. 27. Systems Ba/sub 4-x/Sr/sub x/B/sup II/Re/sub 2/vacantO/sub 12/, Ba/sub 4/B/sub 1-x//sup II/Ca/sub x/Re/sub 2/vacantO/sub 12/, and Ba/sub 4-x/La/sub x/B/sup II/Re/sub 2-x/W/sub x/vacantO/sub 12/ with B/sup II/ = Co, Ni

Energy Technology Data Exchange (ETDEWEB)

Herrmann, M; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1981-05-01

In the systems Ba/sub 4-x/Sr/sub x/B/sup II/Re/sub 2/vacantO/sub 12/, Ba/sub 4/B/sub 1-x//sup II/Ca/sub x/Re/sub 2/vacantO/sub 12/ and Ba/sub 4-x/La/sub x/B/sup II/Re/sub 2-x/W/sub x/va/sub x/antO/sub 12/ (B/sup II/ =Co, Ni) hexagonal perovskites with a rhombohedral 12 L structure (general composition A/sub 4/BM/sub 2/vacantO/sub 12/; sequence (hhcc)/sub 3/; space group R3m) are observed. With the exception of Ba/sub 4/NiRe/sub 2/vacantO/sub 12/ the octahedral net consists of BO/sub 6/ single octahedra and M/sub 2/vacantO/sub 12/ face connected blocks (type 1). In type 2 (Ba/sub 4/NiRe/sub 2/vacantO/sub 12/) the M ions are located in the single octahedra and in the center of the groups of three face connected octahedra. The two outer positions of the latter are occupied by B ions and vacancies in the ratio 1:1. The difference between type 1 and 2 are discussed by means of the vibrational and diffuse reflectance spectra.

RE-AIM Checklist for Integrating and Sustaining Tier 2 Social-Behavioral Interventions

Science.gov (United States)

Cheney, Douglas A.; Yong, Minglee

2014-01-01

Even though evidence-based Tier 2 programs are now more commonly available, integrating and sustaining these interventions in schools remain challenging. RE-AIM, which stands for Reach, Effectiveness, Adoption, Implementation, and Maintenance, is a public health framework used to maximize the effectiveness of health promotion programs in…

Kalinnikov: Sinfonie Nr.2 A-Dur, Ouvertüre Zar Boris / Hanspeter Krellmann

Index Scriptorium Estoniae

Krellmann, Hanspeter

1990-01-01

Uuest heliplaadist "Kalinnikov: Sinfonie Nr.2 A-Dur, Ouvertüre Zar Boris, Die Zeder und die Palme. Scottish National Orchestra, Neeme Järvi" (AD: 1989) Chandos / Koch Records CD 8805 (WD: 59'40") DDD

Probing in-plane anisotropy in few-layer ReS2 using low frequency noise measurement

Science.gov (United States)

Mitra, Richa; Jariwala, Bhakti; Bhattacharya, Arnab; Das, Anindya

2018-04-01

ReS2, a layered two-dimensional material popular for its in-plane anisotropic properties, is emerging as one of the potential candidates for flexible electronics and ultrafast optical applications. It is an n-type semiconducting material having a layer independent bandgap of 1.55 eV. In this paper we have characterized the intrinsic electronic noise level of few-layer ReS2 for the first time. Few-layer ReS2 field effect transistor devices show a 1/f nature of noise for frequency ranging over three orders of magnitude. We have also observed that not only the electrical response of the material is anisotropic; the noise level is also dependent on direction. In fact the noise is found to be more sensitive towards the anisotropy. This fact has been explained by evoking the theory where the Hooge parameter is not a constant quantity, but has a distinct power law dependence on mobility along the two-axes direction. The anisotropy in 1/f noise measurement will pave the way to quantify the anisotropic nature of two-dimensional (2D) materials, which will be helpful for the design of low-noise transistors in future.

VQABQ: Visual Question Answering by Basic Questions

KAUST Repository

Huang, Jia-Hong

2017-03-19

Taking an image and question as the input of our method, it can output the text-based answer of the query question about the given image, so called Visual Question Answering (VQA). There are two main modules in our algorithm. Given a natural language question about an image, the first module takes the question as input and then outputs the basic questions of the main given question. The second module takes the main question, image and these basic questions as input and then outputs the text-based answer of the main question. We formulate the basic questions generation problem as a LASSO optimization problem, and also propose a criterion about how to exploit these basic questions to help answer main question. Our method is evaluated on the challenging VQA dataset and yields state-of-the-art accuracy, 60.34% in open-ended task.

VQABQ: Visual Question Answering by Basic Questions

KAUST Repository

Huang, Jia-Hong; Alfadly, Modar; Ghanem, Bernard

2017-01-01

Taking an image and question as the input of our method, it can output the text-based answer of the query question about the given image, so called Visual Question Answering (VQA). There are two main modules in our algorithm. Given a natural language question about an image, the first module takes the question as input and then outputs the basic questions of the main given question. The second module takes the main question, image and these basic questions as input and then outputs the text-based answer of the main question. We formulate the basic questions generation problem as a LASSO optimization problem, and also propose a criterion about how to exploit these basic questions to help answer main question. Our method is evaluated on the challenging VQA dataset and yields state-of-the-art accuracy, 60.34% in open-ended task.

Preparation, biodistribution, and dosimetry of 188Re-Labeled MoAb ior cea1 and its f(ab')2 fragments by avidin-biotin strategy

International Nuclear Information System (INIS)

Ferro-Flores, Guillermina; Pimentel-Gonzalez, Gilmara; Gonzalez-Zavala, Maria Antonia; Murphy, Consuelo Arteaga de; Melendez-Alafort, Laura; Tendilla, Jose I.; Croft, Barbara Y.

1999-01-01

The biotinylated monoclonal antibody (MoAb) ior cea1 and its F(ab') 2 fragments were labeled with Re-188 by combination of avidin-biotin strategy. 188 Re-MoAb, 188 Re-MoAb-biotin, 188 Re-F(ab') 2 , and 188 Re-F(ab') 2 -biotin preparations were produced for these studies with specific activities of 1.30±0.18 GBq/mg and from instant freeze-dried kit formulations using ethane-1-hydroxy-1,1-diphosphonic acid (EHDP) as a weak competing ligand. There were no significant differences (p>0.05) between the biodistribution in mice of biotinylated and unbiotinylated 188 Re-labeled immunoconjugates. When avidin was injected as a chase after injection of 188 Re-MoAb-biotin or 188 Re-F(ab') 2 -biotin, the blood radioactivity level decreased approximately 75% (cumulated activity) and the effective dose decreased almost 25% with respect to that of the radioimmunoconjugates in which the chase effect was not used. Our results suggest that 188 Re-labeled biotinylated MoAb ior cea1 and its F(ab') 2 fragments prepared by this method are stable complexes in vivo

Formative student-authored question bank: perceptions, question quality and association with summative performance.

Science.gov (United States)

Walsh, Jason L; Harris, Benjamin H L; Denny, Paul; Smith, Phil

2018-02-01

There are few studies on the value of authoring questions as a study method, the quality of the questions produced by students and student perceptions of student-authored question banks. Here we evaluate PeerWise, a widely used and free online resource that allows students to author, answer and discuss multiple-choice questions. We introduced two undergraduate medical student cohorts to PeerWise (n=603). We looked at their patterns of PeerWise usage; identified associations between student engagement and summative exam performance; and used focus groups to assess student perceptions of the value of PeerWise for learning. We undertook item analysis to assess question difficulty and quality. Over two academic years, the two cohorts wrote 4671 questions, answered questions 606 658 times and posted 7735 comments. Question writing frequency correlated most strongly with summative performance (Spearman's rank: 0.24, p=<0.001). Student focus groups found that: (1) students valued curriculum specificity; and (2) students were concerned about student-authored question quality. Only two questions of the 300 'most-answered' questions analysed had an unacceptable discriminatory value (point-biserial correlation <0.2). Item analysis suggested acceptable question quality despite student concerns. Quantitative and qualitative methods indicated that PeerWise is a valuable study tool. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Olefins metathesis, synthesis and properties of homogeneous models of the Re{sub 2}O{sub 7}/Al{sub 2}O{sub 3} catalyst; Methathese des olefines, synthese et proprietes des modeles homogenes du catalyseur Re{sub 2}O{sub 7}/Al{sub 2}O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Doledec, G.

1999-10-05

The aim of this work was to synthesize and to study homogeneous models of the rhenium oxide on alumina catalyst in order to better understand the influence of the alumina environment over the activity in olefin metathesis. A series of aluminium complexes (ArO){sub 2}Al-Y have been synthesised, where ArO is a 4-substituted-2,6-di-tert-butyl-phenoxy, or (ArO){sub 2} is a CH{sub 2{sup -}} or S-ortho bridged-4,4'-di-tert-butyl-di-phenoxy, and Y is an alkyl or chlorine ligand. The reaction of (ArO){sub 2}Al-Cl with AgReO{sub 4} led to new complexes (ArO){sub 2}Al-OReO{sub 3} (A). These complexes exhibit a low to moderate activity in metathesis of 2-pentene (TOF = 0,5 min{sup -1} at 25 deg. C in a toluene solution). Complexes (ArO){sub 2}Al-R (R = iBu, Et) react with Re{sub 2}O{sub 7} in THF or dioxane giving type B complexes including oligomeric linkages like O{sub 3}Re-[Al(OAr)-O){sub 2}-ReO{sub 3}. They show a fairly high activity in the metathesis of 2-pentene, with TOF values as high as 100 min{sup -1}. As far as we know, these are the most active rhenium-based homogeneous metathesis catalysts. Complexes type A may be converted into type B complexes upon reaction with (ArO){sub 2}Al-R in an ether solvent. The high activity of B complexes is tentatively related to the Al-O-Al linkages that are molecular in the homogeneous models or present at the surface of the alumina in the heterogeneous catalyst. These results bear out again the role of the Lewis acidity in these catalysts. We used (ArO){sub 2}Al-R complexes to modify the heterogenous catalyst. It appears that it is an excellent way to reduce the rhenium loading without any loss of activity. (author)

Relaxation of atomic state multipoles by radiation re-absorption: Neon 2p2 atoms in a discharge plasma

International Nuclear Information System (INIS)

Nimura, M.; Imagawa, T.; Hasuo, M.; Fujimoto, T.

2005-01-01

In a positive column of a glow discharge in the magnetic field of 36.4G, a linearly polarized laser pulse or a circularly polarized laser pulse has produced polarized neon atoms (alignment or orientation) in the 2p 2 (Paschen notation) level from the 1s 3 level. The subsequent fluorescence to the 1s 2 level was observed with its polarized components resolved. Depopulation, disorientation and disalignment rates of the 2p 2 atom were measured and their discharge current dependences were examined for a discharge current from 0.4 to 2.0mA. The degrees of radiation re-absorption, or the optical thickness, of the transition lines from the 2p 2 level to the 1s 2 -1s 5 levels were measured as functions of the discharge current. A Monte Carlo simulation was performed by which the depopulation, disorientation and disalignment rates by the radiation re-absorption for these transitions were determined. The calculated rates were compared with the observed ones and found to reproduce the their discharge current dependences. D'Yankonov and Perel's analytical expression for these rates was quantified from comparison with the Monte Carlo results

Retour "écologique" sur la question des nitrates

OpenAIRE

Buson, Christian

2012-01-01

Un examen critique de la question des nitrates est proposé dans cet article, à la lumière des connaissances disponibles dans différentes disciplines. Au plan sanitaire, la norme sur l’eau potable établie depuis plusieurs décennies résulte d’une erreur ancienne aujourd’hui reconnue comme telle. Les nitrates n’engendrent aucun trouble sanitaire et les griefs tels que la méthémoglobinémie du nourrisson, ou le risque de cancer du à la formation de nitrosamines, qui les ont...

Electronic and optical properties of layered RE{sub 2}Ti{sub 2}O{sub 7} (RE = Ce and Pr) from first principles

Energy Technology Data Exchange (ETDEWEB)

Sayede, A. [Universite Lille Nord de France, F-59000 Lille (France); Khenata, R. [Laboratoire de Physique Quantique et de Modlisation Mathmatique, Universite de Mascara, Mascara, 29000 (Algeria); Chahed, A.; Benhelal, O. [Condensed Matter and Sustainable Development Laboratory, Djillali Liabes University of Sidi Bel-Abbes, Sidi Bel-Abbes 22000 (Algeria)

2013-05-07

We have studied the structural and electronic properties of Ce{sub 2}Ti{sub 2}O{sub 7} (CeTO) and Pr{sub 2}Ti{sub 2}O{sub 7} (PrTO) by first-principles density functional theory calculations. The computed structural parameters are in fairly good agreement with the available experimental findings. Band structure calculations using the GGA+U approach predict an insulating ground state for the herein studied compounds. The insulating band gaps of 2.00 eV and 2.83 eV are found for CeTO and PrTO, respectively. The analysis of the density of states reveals that the strongly localized RE 4f levels act as charge-trapping sites, predicting a lower photocatalytic activity for CeTO. We have also calculated the optical properties for both CeTO and PrTO. Based on these properties, it is predicted that these titanates are insensitive to ultra-violet radiation, while they are more sensitive to frequencies of the radiation in visible and early UV regions.

Re-annotation and re-analysis of the Campylobacter jejuni NCTC11168 genome sequence

Directory of Open Access Journals (Sweden)

Dorrell Nick

2007-06-01

Full Text Available Abstract Background Campylobacter jejuni is the leading bacterial cause of human gastroenteritis in the developed world. To improve our understanding of this important human pathogen, the C. jejuni NCTC11168 genome was sequenced and published in 2000. The original annotation was a milestone in Campylobacter research, but is outdated. We now describe the complete re-annotation and re-analysis of the C. jejuni NCTC11168 genome using current database information, novel tools and annotation techniques not used during the original annotation. Results Re-annotation was carried out using sequence database searches such as FASTA, along with programs such as TMHMM for additional support. The re-annotation also utilises sequence data from additional Campylobacter strains and species not available during the original annotation. Re-annotation was accompanied by a full literature search that was incorporated into the updated EMBL file [EMBL: AL111168]. The C. jejuni NCTC11168 re-annotation reduced the total number of coding sequences from 1654 to 1643, of which 90.0% have additional information regarding the identification of new motifs and/or relevant literature. Re-annotation has led to 18.2% of coding sequence product functions being revised. Conclusions Major updates were made to genes involved in the biosynthesis of important surface structures such as lipooligosaccharide, capsule and both O- and N-linked glycosylation. This re-annotation will be a key resource for Campylobacter research and will also provide a prototype for the re-annotation and re-interpretation of other bacterial genomes.

Re-Imagining the Nature of (Student-Focused) Learning through Digital Technology

Science.gov (United States)

Hood, Nina

2018-01-01

Digital technology is frequently positioned as being central to the establishment of a 'future focused' education system that provides high quality student-focused learning opportunities and re-envisioned educational outcomes. While recognising the potential of technology, this paper explores some of the questions about its role in education and…

41 CFR 300-2.21 - How is the rule expressed in the question and answer format?

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false How is the rule expressed in the question and answer format? 300-2.21 Section 300-2.21 Public Contracts and Property Management Federal Travel Regulation System GENERAL INTRODUCTION 2-HOW TO USE THE FTR Question & Answer...

Reaalsuse re/presenteerimise strateegiad etenduskunstides / Strategies to Re-(Present Reality in the Performing Arts

Directory of Open Access Journals (Sweden)

Anneli Saro

2014-12-01

Full Text Available Contemporary theatre, and performing arts in general, no longer seems to be interested in the representation of illusion and reality. There seems to be an increasing emphasis on free play or/and an immediate presentation of reality. And, thus, the mainstream is moving towards the aesthetics of performance art and happenings, where recurrence is shunned and improvisation is emphasized on one hand, while the boundary between performance and reality is obscured on the other. This means that representative theatre, where performers and objects signify someone/something other, is retreating to give way to presentative theatre, where the performers and objects primarily signify themselves.  In the light of the aforementioned, this paper attempts to answer the following questions: how has the presentation of reality in theatre changed over the last forty years, how does presentative theatre differ from representative theatre and does presentative theatre arrive at a deeper/more objective understanding of reality or merely create yet another illusion? In order to answer these questions, the complicated relationship between art and reality as well as issues intrinsic to realist theatre are analysed. The author attempts to prove that it is difficult to find anything fundamentally new in 21st century theatre practice. A lot of the currently fashionable strategies are further developments of older waves, such as realism, or experiments placed in a new temporal and cultural context.  Considering the physical relationship between performing arts and reality, the third section of the paper analyses three strategies of (re-presenting reality: 1. Presenting the elements of reality on stage: performances of documentary material in as authentic a manner as possible, i.e. the self-presentations of so-called regular people or actors, etc. 2. Giving reality an artistic framework: audience tours through the city led by guide(s/performer(s or audio guides. 3

Precipitation behaviors of Cs and Re(/Tc) by NaTPB and TPPCl from a simulated fission products-(Na2CO3-NaHCO3)-H2O2 solution

International Nuclear Information System (INIS)

Lee, Eil Hee; Lim, Jae Gwan; Chung, Dong Yong; Yang, Han Beum; Kim, Kwang Wook

2010-01-01

In this study, the removal of Cs and Tc from a simulated fission products (FP) solution which were co-dissolved with U during the oxidative-dissolution of spent fuel in a mixed carbonate solution of (Na 2 CO 3 -NaHCO 3 )-H 2 O 2 was investigated by using a selective precipitation method. As Cs and Tc might cause an unstable behavior due to the high decay heat emission of Cs as well as the fast migration of Tc when disposed of underground, it is one of the important issues to removal them in views of the increase of disposal safety. The precipitation of Cs and Re (as a surrogate for Tc) was examined by introducing sodium tetraphenylborate (NaTPB) and tetraphenylphosponium chloride (TPPCl), respectively. Precipitation of Cs by NaTPB and that of Re by TPPCl were completed within 5 minutes. Their precipitation rates were not influenced so much by the temperature and stirring speed even if they were increased by up to 50 .deg. C and 1,000 rpm. However, the pH of the solution was found to have a great influence on the precipitation with NaTPB and TPPCl. Since Mo tends to co-precipitate with Re at a lower pH, especially, it was effective that a selective precipitation of Re by TPPCl was carried out at pH of above 9 without co-precipitation of Mo and Re. Over 99% of Cs was precipitated when the ratio of [NaTPB]/[Cs]>1 and more than 99% of Re, likewise, was precipitated when the ratio of [TPPCl]/[Re]>1.

Re-thinking visuals: Understanding discursive reformulation of visuals to inform Peace Journalism

Directory of Open Access Journals (Sweden)

Saumava Mitra

2014-10-01

Full Text Available Current definitions of 'peace journalism' are inadequate to take on the full implication of the 'open' nature of visual content because normative discussions are restricted to explicit content of visuals while not underlining the importance of their implicit meaning. Analyzing a photo feature showing empowered Afghan women called 'Liberated in the Hindukush' published in the Foreign Policy magazine as a case study, the article identifies how the particular media product in question fits existing descriptions of (if only, 'accidental' peace journalism but its contextual re-deployment of meaning is contrary to its content. The article argues that the norms of peace journalism need to be revised to account for the subtlety of discursive re-appropriation and re-assimilation of media content, especially visuals.

Standard Molar Enthalpy of Formation of RE(C5H8NS2)3(o-phen)

Institute of Scientific and Technical Information of China (English)

MENG Xiang-Xin; GAO Sheng-Li; CHEN San-Ping; YANG Xu-Wu; XIE Gang; SHI Qi-Zhen

2005-01-01

Five solid ternary complexes of RE(C5H8NS2)3(o-phen) (RE=Ho, Er, Tm, Yb, Lu) have been synthesized in absolute ethanol by rare earth chloride low hydrate reacting with the mixed ligands of ammonium pyrrolidinedithiocarbamate (APDC) and 1,10-phenanthroline·H2O (o-phen·H2O) in the ordinary laboratory atmosphere without any cautions against moisture or air. IR spectra of the complexes showed that the RE3+ coordinated with six sulfur atoms of three PDC- and two nitrogen atoms of o-phen·H2O. It was assumed that the coordination number of RE3+was eight. The constant-volume combustion energies of the complexes, △cU, were determined as (-16788.46±7.74), (- 15434.53± 8.28), (- 15287.807.31), (- 15200.50±7.22) and (- 15254.34±6.61) kJ·mol-1, respectively, by a precise rotating-bomb calorimeter at 298.15 K. Its standard molar enthalpies of combustion, △cH m,and standard molar enthalpies of formation, △fH m, were calculated as (-16803.95 ±7.74), (-15450.02±8.28),(-15303.29±9.28), (-15215.99±7.22), (-15269.83±6.61) kJ·mol-1 and (-1115.42±8.94), (-2477.80±9.15), (-2619.95 ±10.44), (-2670.17 ± 8.22), ( -2650.06± 8.49) kJ·mol-1, respectively.

Ternary gallides RE{sub 4}Rh{sub 9}Ga{sub 5}, RE{sub 5}Rh{sub 12}Ga{sub 7} and RE{sub 7}Rh{sub 18}Ga{sub 11} (RE=Y, La-Nd, Sm, Gd, Tb). Intergrowth structures with MgCu{sub 2} and CaCu{sub 5} related slabs

Energy Technology Data Exchange (ETDEWEB)

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

2017-07-01

Fourteen ternary gallides RE{sub 4}Rh{sub 9}Ga{sub 5}, RE{sub 5}Rh{sub 12}Ga{sub 7} and RE{sub 7}Rh{sub 18}Ga{sub 11} (RE=Y, La-Nd, Sm, Gd, Tb) were synthesized from the elements by arc-melting, followed by different annealing sequences either in muffle or induction furnaces. The samples were characterized through Guinier powder patterns and the crystal structures of Ce{sub 4}Rh{sub 9}Ga{sub 5}, Ce{sub 5}Rh{sub 12}Ga{sub 7}, Ce{sub 7}Rh{sub 18}Ga{sub 11}, Nd{sub 5}Rh{sub 10.44(4)}Ga{sub 8.56(4)}, Nd{sub 4}Rh{sub 9}Ga{sub 5} and Gd{sub 4}Rh{sub 9}Ga{sub 5} were refined from single crystal X-ray diffractometer data. The new gallides are the n=2, 3 and 5 members of the RE{sub 2+n} Rh{sub 3+3n} Ga{sub 1+2n} structure series in the Parthe intergrowth concept. The slabs of these intergrowth structures derive from the cubic Laves phase MgCu{sub 2} (Mg{sub 2}Ni{sub 3}Si as ternary variant) and CaCu{sub 5} (CeCo{sub 3}B{sub 2} as ternary variant). Only the Nd{sub 5}Rh{sub 10.44(4)}Ga{sub 8.56(4)} crystal shows Rh/Ga mixing within the Laves type slabs. Magnetic susceptibility measurements reveal Pauli paramagnetism for Y{sub 4}Rh{sub 9}Ga{sub 5} and Curie-Weiss paramagnetism for Gd{sub 4}Rh{sub 9}Ga{sub 5} and Tb{sub 4}Rh{sub 9}Ga{sub 5}. Low-temperature data show ferromagnetic ordering at T{sub C}=78.1 (Gd{sub 4}Rh{sub 9}Ga{sub 5}) and 55.8 K (Tb{sub 4}Rh{sub 9}Ga{sub 5}).

Closing the gap in travel medicine: reframing research questions for a new era.

Science.gov (United States)

Chen, Lin H; Leder, Karin; Wilson, Mary E

2017-07-01

Travel medicine needs are changing. New patterns of travel, including greater travel by individuals from emerging economies with different values in costs, risks and benefits, must be considered. This review aims to (1) highlight selected studies that have been published that address previously identified gaps in knowledge; (2) propose possible ways to consider questions regarding travel medicine practice for travelers from emerging economies, underscoring priorities for research focusing on these important populations; (3) highlight potential deficiencies in relevance of current international guidelines as they pertain to travelers from emerging economies; (4) frame research questions for travelers from emerging economies and (5) consider roles for ISTM in closing the gap. We reviewed past travel medicine research priorities published in 2010 to identify publications that responded to some research questions posed. We also reviewed CDC and WHO recommendations and assessed their applicability to travelers from emerging economies. Recent publications have responded to some research questions, but gaps remain and new questions have emerged. Re-framing of several key research questions is needed for travelers from emerging economies. A new challenge looms for traditional travel medicine fields to identify and attend to knowledge and guideline gaps, particularly to rethink questions regarding travel medicine to make them relevant for travelers from emerging economies. The International Society of Travel Medicine is well positioned to assist emerging economies assess their resources and needs, formulate research priorities and tailor the development of travel medicine into a framework aligned to their requirements. © International Society of Travel Medicine, 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Questioning Questions: Elementary Teachers' Adaptations of Investigation Questions Across the Inquiry Continuum

Science.gov (United States)

Biggers, Mandy

2018-02-01

Questioning is a central practice in science classrooms. However, not every question translates into a "good" science investigation. Questions that drive science investigations can be provided by many sources including the teacher, the curriculum, or the student. The variations in the source of investigation questions were explored in this study. A dataset of 120 elementary science classroom videos and associated lesson plans from 40 elementary teachers (K-5) across 21 elementary school campuses were scored on an instrument measuring the amount of teacher-direction or student-direction of the lessons' investigation questions. Results indicated that the investigation questions were overwhelmingly teacher directed in nature, with no opportunities for students to develop their own questions for investigation. This study has implications for researchers and practitioners alike, calling attention to the teacher-directed nature of investigation questions in existing science curriculum materials, and the need for teacher training in instructional strategies to adapt their existing curriculum materials across the continuum of teacher-directed and student-directed investigation questions. Teachers need strategies for adapting the teacher-directed questions provided in their existing curriculum materials in order to allow students the opportunity to engage in this essential scientific practice.

The collaborative ec project ReCosy - 16203

International Nuclear Information System (INIS)

Kienzler, Bernhard; Buckau, Gunnar

2009-01-01

The Collaborative Project (CP) ReCosy (Redox Controlling Systems) was established in 2008. It falls within the EURATOM program and is implemented within the European Commission's 7. Framework Program. Main objectives of CP ReCosy are the sound understanding of redox phenomena controlling the long-term release/retention of radionuclides in nuclear waste disposal and providing tools to apply the results to Performance Assessment/Safety Case. Although redox is not a new geochemical problem, different questions are still not resolved and thus raised by implementers and scientists. Radionuclide redox transformations on minerals are considered to be decisive scenarios in various FEP lists. 32 institutions from 13 European countries contribute to the 4-years CP by i) development of advanced analytical tools, ii) investigations of processes responsible for redox control (thermodynamically and kinetically controlled processes, surface reactions and microbial processes), iii) provision of required data on redox controlling processes, and iv) response of the disposal systems to external/internal disturbances. Systems which are investigated comprise simple very well defined ones under controlled laboratory conditions, complex laboratory systems, near-natural systems in the laboratory, real systems, and near-field systems controlled spent nuclear fuel. The scientific results of the CP ReCosy are reported during annual workshops (AW). The first AW took place in February 10-12, 2009. The scientific contributions underwent a peer review and are published in the form of workshop proceedings together with scientific-technical overview papers of the different project work packages. The present paper summarizes the main results obtained after the first year of ReCosy. The status during the project preparation phase of the CP ReCosy is published elsewhere. (authors)

Socio-Economic status of parents as a correlate of re-entry of girls ...

African Journals Online (AJOL)

economic status (SES) and re-entry of girls into school in Edo State, Nigeria. One research question and one hypothesis were formulated for the study. Two research instruments, the “Socio-Economic Status of Parents” and the “Reentry into ...

Evaluating the CO 2 emissions reduction potential and cost of power sector re-dispatch

Energy Technology Data Exchange (ETDEWEB)

Steinberg, Daniel C.; Bielen, David A.; Townsend, Aaron

2018-01-01

Prior studies of the U.S. electricity sector have recognized the potential to reduce carbon dioxide (CO2) emissions by substituting generation from coal-fired units with generation from under-utilized and lower-emitting natural gas-fired units; in fact, this type of 're-dispatch' was invoked as one of the three building blocks used to set the emissions targets under the Environmental Protection Agency's Clean Power Plan. Despite the existence of surplus natural gas capacity in the U.S., power system operational constraints not often considered in power sector policy analyses, such as transmission congestion, generator ramping constraints, minimum generation constraints, planned and unplanned generator outages, and ancillary service requirements, could limit the potential and increase the cost of coal-to-gas re-dispatch. Using a highly detailed power system unit commitment and dispatch model, we estimate the maximum potential for re-dispatch in the Eastern Interconnection, which accounts for the majority of coal capacity and generation in the U.S. Under our reference assumptions, we find that maximizing coal-to-gas re-dispatch yields emissions reductions of 230 million metric tons (Mt), or 13% of power sector emissions in the Eastern Interconnection, with a corresponding average abatement cost of $15-$44 per metric ton of CO2, depending on the assumed supply elasticity of natural gas.

Development of thermocouple re-instrumentation technique for irradiated fuel rod. Techniques for making center hole into UO2 pellets and thermocouple re-instrumentation to fuel rod

International Nuclear Information System (INIS)

Shimizu, Michio; Saito, Junichi; Oshima, Kunio

1995-07-01

The information on FP gas pressure and centerline temperature of fuel pellets during power transient is important to study the pellet clad interaction (PCI) mechanism of high burnup LWR fuel rods. At the Department of JMTR, a re-instrumentation technique of FP gas pressure gage for an irradiated fuel rod was developed in 1990. Furthermore, a thermocouple re-instrumentation technique was successfully developed in 1994. Two steps were taken to carry out the development program of the thermocouple re-instrumentation technique. In the first step, a drilling technique was developed for making a center hole of the irradiated fuel pellets. Various drilling tests were carried out using dummy of fuel rods consisted of Ba 2 FeO 3 pellets and Zry-2 cladding. On this work it is important to keep the pellets just the state cracked at a power reactor. In these tests, the technique to fix the pellets by frozen CO 2 was used during the drilling work. Also, diamond drills were used to make the center hole. These tests were completed successfully. A center hole, 54mm depth and 2.5mm diameter, was realized by these methods. The second step of this program is the in-pile demonstration test on an irradiated fuel rod instrumented dually a thermocouple and FP gas pressure gage. The demonstration test was carried out at the JMTR in 1995. (author)

A single crystal study of RE{sub 14}Co{sub 3}In{sub 3} (RE = Y, Tb, Dy, Ho, Er)

Energy Technology Data Exchange (ETDEWEB)

Zaremba, V.I.; Kalychak, Y.M.; Dzevenko, M.V. [Inorganic Chemistry Dept., Ivan Franko National Univ. of Lviv (Ukraine); Rodewald, U.Ch.; Heying, B.; Poettgen, R. [Inst. fuer Anorganische und Analytische Chemie, Westfaelische Wilhelms-Univ. Muenster (Germany)

2006-01-01

The rare earth-cobalt-indides RE{sub 14}Co{sub 3}In{sub 3} (RE = Y, Tb, Dy, Ho, Er) were prepared in polycrystalline form from the elements by arc-melting. Small single crystals were grown through a special annealing sequence. The compounds were investigated on the basis of X-ray powder and single crystal data: Lu{sub 14}Co{sub 2}In{sub 3} (Gd{sub 14}Co{sub 3}In{sub 2.7}) type, P4{sub 2}/nmc, Z = 4, a = 959.0(1), c = 2319.1(5) pm, wR2 = 0.055, 2289 F{sup 2} values, 65 variables for Y{sub 13.90}Co{sub 2.99}In{sub 3.02}, a = 953.8(1), c = 2315.8(5) pm, wR2 = 0.108, 2357 F{sup 2} values, 65 variables for Tb{sub 13.92}Co{sub 3.01}In{sub 2.92}, a = 949.24(3), c = 2296.5(1) pm, wR2 = 0.129, 2518 F{sup 2} values, 65 variables for Dy{sub 13.90}Co{sub 2.97}In{sub 2.95}, a = 946.3(1), c = 2289.0(5) pm, wR2 = 0.099, 2297 F{sup 2} values, 64 variables for Ho{sub 14}Co{sub 2.80}In{sub 2.89}, and a = 941.0(1), c = 2274.2(5) pm, wR2 = 0.140, 2450 F{sup 2} values, 65 variables for Er{sub 13.83}Co{sub 2.88}In{sub 3.10}. All RE{sub 14}Co{sub 3}In{sub 3} indides show a small degree of In/Co mixing (between 7 and 16% Co) on the 4c In1 site and defects on the 8g Co1 positions (between 84 and 95% Co). Except for the holmium compound, the RE{sub 14}Co{sub 3}In{sub 3} intermetallics also reveal RE/In mixing on the 4c RE1 sites, leading to the refined compositions. The seven crystallographically independent RE sites have between 9 and 10 nearest RE neighbors. The RE{sub 14}Co{sub 3}In{sub 3} structures consist of a complex intergrowth of rare earth based polyhedra. Both cobalt sites have a distorted trigonal-prismatic rare earth coordination. An interesting feature is the In2-In2 dumb-bell with an In2-In2 distance of 300 pm (for Ho{sub 14}Co{sub 2.80}In{sub 2.89}). The crystal chemistry of the RE{sub 14}Co{sub 3}In{sub 3} indides is discussed. (orig.)

Re-admissions, re-operations and length of stay in hospital after aseptic revision knee replacement in Denmark

DEFF Research Database (Denmark)

Lindberg-Larsen, M.; Jørgensen, C. C.; Hansen, Torben Bæk

2014-01-01

of hospital stay was four days (interquartile range: 3 to 5), with a 90 days re-admission rate of 9.9%, re-operation rate of 3.5% and mortality rate of 0.2%. The age ranges of 51 to 55 years (p = 0.018), 76 to 80 years (p re-admission...

Spin-glass-like behaviour in IrSr2RECu2O8 (RE=Sm and Eu)

International Nuclear Information System (INIS)

Santos-Garcia, A.J. dos; Duijn, J. van; Alario-Franco, M.A.

2008-01-01

We report the results of magnetic and specific heat measurements on the 1212-type compounds IrSr 2 RECu 2 O 8 with RE=Sm and Eu, prepared by high-pressure and high-temperature synthesis. The magnetic susceptibility of these compounds shows a large difference in the temperature dependence of the magnetization measured under zero-field-cooled and field-cooled conditions below 87 and 71 K, respectively, and upon further cooling below ∼10 K substantial maxima are observed too. Further AC susceptibility measurements support a glassy behaviour in lower magnetic transitions whereas the specific heat measurements do not show the typical long-range ordering commonly displayed in ferro, ferri or antiferromagnetic transitions. Hysteresis loops suggest the presence of magnetic clusters in the otherwise paramagnetic zone, indicating that these compounds probably display a reentrant spin-glass transition. Results are presented and discussed. - Graphical abstract: IrSr 2 RECu 2 O 8 with RE=Sm and Eu were prepared by high-pressure and high-temperature synthesis. Both samples adopt a M-1212-type perovskite structure and a microdomain texturing of the long c-axis is observed by TEM. A very interesting magnetic behaviour is observed in these materials. A 'cluster by cluster freezing' model is proposed, instead of the classical individual spin freezing one to explain the spin-glass-like behaviour that seems to coexist with weak ferromagnetism in both compounds

Behavior of HfB2-SiC Materials in Simulated Re-Entry Environments

Science.gov (United States)

Ellerby, Don; Beckman, Sarah; Irby, Edward; Johnson, Sylvia M.; Gunsman, Michael; Gasch, Matthew; Ridge, Jerry; Martinez, Ed; Squire, Tom; Olejniczak, Joe

2003-01-01

The objectives of this research are to: 1) Investigate the oxidation/ablation behavior of HfB2/SiC materials in simulated re-entry environments; 2) Use the arc jet test results to define appropriate use environments for these materials for use in vehicle design. The parameters to be investigated include: surface temperature, stagnation pressure, duration, number of cycles, and thermal stresses.

Synthesis under ambient pressure and tri-axial magnetic orientation in REBa2Cu4O8 (RE = Y, Sm, Eu, Gd, Dy, Ho, Er)

International Nuclear Information System (INIS)

Yamaki, M.; Horii, S.; Haruta, M.; Maeda, T.; Shimoyama, J.

2011-01-01

REBa 2 Cu 4 O 8 (RE124) was synthesized by a flux method in ambient pressure for RE = Y, Sm, Eu, Gd, Dy, Ho and Er. Tri-axial orientation of RE124 was achieved in a modulated rotating magnetic field of 10 T. Orientation axes in RE124 depended on the type of RE. Magnetization axes were determined from magnetic anisotropies of Cu and RE ions. We report the rare-earth (RE)-dependent magnetization axes of REBa 2 Cu 4 O 8 , which was synthesized by a flux method under ambient pressure, using powder samples tri-axially oriented in a modulated rotating magnetic field of 10 T. By optimizing the growth temperature and cooling rate, RE124 crystals were successfully grown for RE = Y, Sm, Eu, Gd, Dy, Ho, and Er. From the X-ray diffraction measurement, the magnetically oriented directions were largely dependent on the type of RE ions of RE124. However, the tri-axial magnetic anisotropies of RE124 could be qualitatively understood in terms of the magnitude relation between the single-ion magnetic anisotropy of RE 3+ ions and the magnetic anisotropy generated by the CuO 2 plane and Cu-O chain. For the practical use of this magneto-scientific process, the control of magnetization axes and tri-axial magnetic anisotropies through crystallochemical control is indispensable.

Temperature-programmed reaction of CO2 reduction in the presence of hydrogen over Fe/Al2O3, Re/Al2O3 and Cr-Mn-O/Al2O3 catalysts

International Nuclear Information System (INIS)

Mirzabekova, S.R.; Mamedov, A.B.; Krylov, O.V.

1996-01-01

Regularities in CO 2 reduction have been studied using the systems Fe/Al 2 O 3 , Re/Al 2 O 3 and Cr-Mn-O/Al 2 O 3 under conditions of thermally programmed reaction by way of example. A sharp increase in the reduction rate in the course of CO 2 interaction with reduced Fe/Al 2 O 3 and Re/Al 2 O 3 , as well as with carbon fragments with addition in CO 2 flow of 1-2%H 2 , has been revealed. The assumption is made on intermediate formation of a formate in the process and on initiating effect of hydrogen on CO 2 reduction by the catalyst. Refs. 26, figs. 10

Identification of a potential superhard compound ReCN

International Nuclear Information System (INIS)

Fan, Xiaofeng; Li, M.M.; Singh, David J.; Jiang, Qing; Zheng, W.T.

2015-01-01

Highlights: • We identify a new ternary compound ReCN with theoretical calculation. • The ternary compound ReCN is with two stable structures with P63mc and P3m1. • ReCN is a semiconductor from the calculation of electronic structures. • ReCN is found to possess the outstanding mechanical properties. • ReCN may be synthesized relatively easily. - Abstract: We identify a new ternary compound, ReCN and characterize its properties including structural stability and indicators of hardness using first principles calculations. We find that there are two stable structures with space groups P63mc (HI) and P3m1 (HII), in which there are no C–C and N–N bonds. Both structures, H1 and III are elastically and dynamically stable. The electronic structures show that ReCN is a semiconductor, although the parent compounds, ReC 2 and ReN 2 are both metallic. ReCN is found to possess the outstanding mechanical properties with the large bulk modulus, shear modulus and excellent ideal strengths. In addition, ReCN may perhaps be synthesized relatively easily because it becomes thermodynamic stable with respect to decomposition at very low pressures

A re-analysis of neutron diffraction data from UO2

International Nuclear Information System (INIS)

Cooper, M.J.; Sakata, M.

1979-04-01

The results of a re-analysis of recent single crystal and powder neutron diffraction data from UO2 are presented and discussed. It is shown that apparent inconsistencies in the results of previous analyses of these data arose from differences between the values assumed for some of the parameters and that the various sets of data are in fact extremely consistent. These data also provide a more accurate value for the ratio of the scattering amplitudes, i.e. bU/bO = 1.451(2), which gives a value for bU = 0.842(2) x 10(-12) cm on the assumption of a value for b0 = 0.5805(11) x 10(-12) cm. The temperature factors for the atoms at room temperature are determined to be BU = 0.23(1)Angstrom and BO = 0.44(1)Angstrom(2). (author)

Systems of OsO4-RuO4 and Re2O7-OsO4

International Nuclear Information System (INIS)

Nisel'son, L.A.; Sokolova, T.D.; Orlov, A.M.; Shorikov, Yu.S.

1981-01-01

The meltability diagrams of the systems OsO 4 -RuO 4 and Re 2 O 7 -OsO 4 are studied using the visual-polythermal method. The OsO 4 -RuO 4 system forms a continuous series of solid solutions with practically rectilinear line of the liquidus. The Re 2 O 7 -OsO 4 system of the eutectic type has the eutectics degenerated from the side of OsO 4 . For the system OsO 4 (basis)-RuO 4 (admixture) the equilibrium coefficient of distribution is determined using the method of directed crystallization [ru

Utility of re-windowing for MR T2-weighted images in differentiating between benign tumors and cysts

International Nuclear Information System (INIS)

Yamamoto, A.; Nishikawa, K.; Otonari-Yamamoto, M.; Sano, T.

2009-01-01

Both benign tumors and cysts in the oral and maxillofacial region show clear borders and homogeneously high signal intensity on magnetic resonance (MR T2-weighted images, making differentiation difficult without contrast enhancement. Windowing for brightness and contrast adjustment may be helpful in interpreting relative signal intensities on MR images. This study was performed to determine whether re-windowing against targeted lesions on T2-weighted images was a useful procedure that would enhance differentiation without invasive contrast enhancement. Twenty-six lesions (13 benign tumors, 13 cysts) that showed clear borders and homogeneously high signal intensity on T2-weighted images were examined. The windowing parameters of axial images were readjusted to emphasize contrast only inside the lesions using automatic density adjustment. Re-windowed images were reviewed by three experienced oral radiologists and categorized based on the internal homogeneity of the lesion into four grades: 0, heterogeneous; 1, slightly heterogeneous; 2, slightly homogeneous; 3, homogeneous. Re-windowing was then evaluated for its usefulness in differentiating between benign tumors and cysts. For cysts, the rates of homogeneous (grades 3 and 2) and heterogeneous intensity (grades 1 and 0) were 66.7 (26/39) and 33.3% (13/39), respectively. For benign tumors, these rates were 33.3 (13/39) and 66.7% (26/39), respectively. Cysts showed a higher rate of homogeneous intensity, while the opposite was true for benign tumors. A significant difference in distribution was observed between cysts and benign tumors (P 2 test). Re-windowing for T2-weighted images is helpful in differentiating between benign tumors and cysts with clear borders and homogeneously high signal intensity on T2-weighted images. (author)

Re-engineering change in higher education

Directory of Open Access Journals (Sweden)

David Allen

1999-01-01

Full Text Available Business Process Re-engineering (BPR is being used in a number of UK Higher Education Institutions (HEIs as a change management strategy. Whilst the focus of these HEIs is on re-engineering administrative services, there are also tentative attempts to redesign teaching and learning. This paper adopts a case study approach to determine the applicability of BPR to HEIs. The research started from a broad research question: How does organisational culture in HEIs impact on the implementation of BPR programmes? The conclusions drawn from the research are that the organisational culture and structure of HEIs limit the degree of change sought from a BPR project: the focus of the case study HEIs was on incremental process improvement of administrative services. The projects in these institutions were not about radical change. BPR techniques are shown to have something to offer HEIs in terms of co-ordinating administrative activities, but the emphasis on IT and processes in project design means the human resources change necessary for significant gains in efficiency is unlikely.

Space-Efficient Re-Pair Compression

DEFF Research Database (Denmark)

Bille, Philip; Gørtz, Inge Li; Prezza, Nicola

2017-01-01

Re-Pair [5] is an effective grammar-based compression scheme achieving strong compression rates in practice. Let n, σ, and d be the text length, alphabet size, and dictionary size of the final grammar, respectively. In their original paper, the authors show how to compute the Re-Pair grammar...... in expected linear time and 5n + 4σ2 + 4d + √n words of working space on top of the text. In this work, we propose two algorithms improving on the space of their original solution. Our model assumes a memory word of [log2 n] bits and a re-writable input text composed by n such words. Our first algorithm runs...

Input Enhancement and L2 Question Formation.

Science.gov (United States)

White, Lydia; And Others

1991-01-01

Investigated the extent to which form-focused instruction and corrective feedback (i.e., "input enhancement"), provided within a primarily communicative program, contribute to learners' accuracy in question formation. Study results are interpreted as evidence that input enhancement can bring about genuine changes in learners' interlanguage…

Studies on the preparation and isomeric composition of [sup 186]Re- and [sup 188]Re-pentavalent rhenium dimercaptosuccinic acid complex

Energy Technology Data Exchange (ETDEWEB)

Singh, J. (Canterbury Univ. (United Kingdom). Biological Lab.); Reghebi, K.; Lazarus, C.R.; Clarke, S.E.M. (Guy' s Hospital, London (United Kingdom)); Callahan, A.P.; Knapp, F.F. Jr. (Oak Ridge National Lab., TN (United States)); Blower, P.J. (Kent and Canterbury Hospital (United Kingdom))

1993-03-01

The preparative conditions for [sup 186]Re(V)DMSA and [sup 188]Re(V)DMSA (DMSA = meso-dimercaptosuccinic acid), [beta]-emitting radiopharmaceuticals that have been shown to localize in medullary thyroid carcinoma, require modification depending on the amount of carrier rhenium and the chemical form and medium in which the rhenium is supplied. Preparative conditions are described for use with carrier-free [sup 188]ReO[sub 4][sup -] in saline, and for use with [sup 186]ReO[sub 4][sup -] in saline, sodium hydroxide or nitric acid. Preparation of [sup 186]Re(V)DMSA (carrier present up to 2 mg per 2.5 ml reaction volume) requires a DMSA:SnCl[sub 2]:Re ratio of 10:5:1 at 100[sup o]C for 30 min. Addition of excess nitric acid or hydrochloric acid up to a concentration of 155 mM does not reduce the yield from 100%. A commercial DMSA kit vial (e.g. Amerscan DMSA) can be used for preparation of [sup 188]Re(V)DMSA (carrier free) provided the required is in a volume of less than 1 ml per vial. A convenient method of concentrating the [sup 188]Re generator eluate to the required volume is described. (Author).

Reaction of ReH sub 7 (PPh sub 3 ) sub 2 with silanes: Preparation and characterization of the first silyl polyhydride complexes, ReH sub 6 (SiR sub 3 )(PPh sub 3 ) sub 2 (SiR sub 3 = SiPh sub 3 , SiEt sub 3 , SiHEt sub 2 )

Energy Technology Data Exchange (ETDEWEB)

Luo, Xiaoliang; Baudry, D.; Boydell, P.; Charpin, P.; Nierlich, M.; Ephritikhine, M.; Crabtree, R.H. (Yale Univ., New Haven, CT (USA) CEA-CEN Saclay, Gif-sur-Yvette (France))

1990-04-18

Reaction of silanes with ReH{sub 7}(PPh{sub 3}){sub 2} (1) gives the novel rhenium silyl hexahydride complexes ReH{sub 6}(SiR{sub 3})(PPh{sub 3}){sub 2} (SiR{sub 3} = SiPh{sub 3} (2a), SiEt{sub 3} (2b), SiHEt{sub 2} (2c)), which have been fully characterized by IR and {sup 1}H, {sup 31}P, and {sup 13}C NMR spectroscopy and, in the case of 2a, by single-crystal x-ray crystallography. The spectroscopic and x-ray diffraction data suggest that 2a-c probably have a classical nine-coordinate tricapped trigonal-prismatic structure with the two phosphine ligands and the silyl group occupying the three equatorial sites and the six hydride ligands occupying the six axial positions. 2a has been obtained in two crystalline forms, one solvated (CH{sub 2}Cl{sub 2}) and the other unsolvated, and structures were determined on both. The crystal structures of crystals of unsolvated 2a and 2a {times} CH{sub 2} Cl{sub 2} are reported. The Re-Si bond lengths, 2.474 (4) {angstrom} (2a) and 2.475 (4) {angstrom} (2a {times} CH{sub 2}Cl{sub 2}), are shorter than the sum of the covalent radii of the Re and Si atoms (2.65 {angstrom}), which is unusual for a transition-metal silyl complex with a formal d{sup 0} configuration. 35 refs., 2 figs., 4 tabs.

Dissecting the Re-Os molybdenite geochronometer.

Science.gov (United States)

Barra, Fernando; Deditius, Artur; Reich, Martin; Kilburn, Matt R; Guagliardo, Paul; Roberts, Malcolm P

2017-11-22

Rhenium and osmium isotopes have been used for decades to date the formation of molybdenite (MoS 2 ), a common mineral in ore deposits and the world's main source of molybdenum and rhenium. Understanding the distribution of parent 187 Re and radiogenic daughter 187 Os isotopes in molybdenite is critical in interpreting isotopic measurements because it can compromise the accurate determination and interpretation of mineralization ages. In order to resolve the controls on the distribution of these elements, chemical and isotope mapping of MoS 2 grains from representative porphyry copper-molybdenum deposits were performed using electron microprobe and nano-scale secondary ion mass spectrometry. Our results show a heterogeneous distribution of 185,187 Re and 192 Os isotopes in MoS 2 , and that both 187 Re and 187 Os isotopes are not decoupled as previously thought. We conclude that Re and Os are structurally bound or present as nanoparticles in or next to molybdenite grains, recording a complex formation history and hindering the use of microbeam techniques for Re-Os molybdenite dating. Our study opens new avenues to explore the effects of isotope nuggeting in geochronometers.

Re-energizing enquiry among our young professionals

Science.gov (United States)

Roychoudhuri, ChandraSekhar

2017-08-01

Children are born with enquiring mindset. They keep on asking questions to explore, understand and take part in their environment. However, modern educational systems discourage persistent enquiring questions. Most students, graduating from college, can use their enquiring faculties only to solve problems at hand. They accept the theories taught as the final models for the laws of nature. They safely assume that no further deeper enquiry is needed. This is a disturbing collective tendency counter to our continuously evolving nature. We should also consciously train our minds to evolve continuously by persistently asking enquiring questions. Therefore, we suggest that we take pro-active steps to re-energize the enquiring mindset among our young professionals by organizing enquiry forums for students from all international Student Chapters during most of our optical society meetings. Panels of volunteer senior scientists should encourage deep enquiring questions from the students. In this paper, as examples, I will present a set of enquiring questions in the field of optics that we have been underscoring to students. This is one of the three papers by this author for this conference, ETOP 100-43. Since scientific content-wise they complement each other, the readers should consult the others. They are: ETP100-36, "Consequences of repeated discovery and benign neglect of non-interaction of waves" and ETP100-83, and "Demonstration and implications when 50% beam combiners can behave as 0 or 100% reflector/transmitter inside some interferometers."

CO2 sensing and CO2 regulation of stomatal conductance: advances and open questions

Science.gov (United States)

Engineer, Cawas; Hashimoto-Sugimoto, Mimi; Negi, Juntaro; Israelsson-Nordstrom, Maria; Azoulay-Shemer, Tamar; Rappel, Wouter-Jan; Iba, Koh; Schroeder, Julian

2015-01-01

Guard cells form epidermal stomatal gas exchange valves in plants and regulate the aperture of stomatal pores in response to changes in the carbon dioxide (CO2) concentration in leaves. Moreover, the development of stomata is repressed by elevated CO2 in diverse plant species. Evidence suggests that plants can sense CO2 concentration changes via guard cells and via mesophyll tissues in mediating stomatal movements. We review new discoveries and open questions on mechanisms mediating CO2-regulated stomatal movements and CO2 modulation of stomatal development, which together function in CO2-regulation of stomatal conductance and gas exchange in plants. Research in this area is timely in light of the necessity of selecting and developing crop cultivars which perform better in a shifting climate. PMID:26482956

Net improvement of correct answers to therapy questions after pubmed searches: pre/post comparison.

Science.gov (United States)

McKibbon, Kathleen Ann; Lokker, Cynthia; Keepanasseril, Arun; Wilczynski, Nancy L; Haynes, R Brian

2013-11-08

Clinicians search PubMed for answers to clinical questions although it is time consuming and not always successful. To determine if PubMed used with its Clinical Queries feature to filter results based on study quality would improve search success (more correct answers to clinical questions related to therapy). We invited 528 primary care physicians to participate, 143 (27.1%) consented, and 111 (21.0% of the total and 77.6% of those who consented) completed the study. Participants answered 14 yes/no therapy questions and were given 4 of these (2 originally answered correctly and 2 originally answered incorrectly) to search using either the PubMed main screen or PubMed Clinical Queries narrow therapy filter via a purpose-built system with identical search screens. Participants also picked 3 of the first 20 retrieved citations that best addressed each question. They were then asked to re-answer the original 14 questions. We found no statistically significant differences in the rates of correct or incorrect answers using the PubMed main screen or PubMed Clinical Queries. The rate of correct answers increased from 50.0% to 61.4% (95% CI 55.0%-67.8%) for the PubMed main screen searches and from 50.0% to 59.1% (95% CI 52.6%-65.6%) for Clinical Queries searches. These net absolute increases of 11.4% and 9.1%, respectively, included previously correct answers changing to incorrect at a rate of 9.5% (95% CI 5.6%-13.4%) for PubMed main screen searches and 9.1% (95% CI 5.3%-12.9%) for Clinical Queries searches, combined with increases in the rate of being correct of 20.5% (95% CI 15.2%-25.8%) for PubMed main screen searches and 17.7% (95% CI 12.7%-22.7%) for Clinical Queries searches. PubMed can assist clinicians answering clinical questions with an approximately 10% absolute rate of improvement in correct answers. This small increase includes more correct answers partially offset by a decrease in previously correct answers.

A parity-breaking electronic nematic phase transition in the spin-orbit coupled correlated metal Cd2Re2O7

Science.gov (United States)

Harter, J. W.; Zhao, Z. Y.; Yan, J.-Q.; Mandrus, D. G.; Hsieh, D.

Strong interactions between electrons are known to drive metallic systems toward a variety of well-known symmetry-broken phases, including superconducting, electronic liquid crystalline, and charge- and spin-density wave ordered states. In contrast, the electronic instabilities of correlated metals with strong spin-orbit coupling have only recently begun to be explored. We uncover a novel multipolar nematic phase of matter in the metallic pyrochlore Cd2Re2O7 using spatially-resolved second-harmonic optical anisotropy measurements. Like previously discovered electronic liquid crystalline phases, this multipolar nematic phase spontaneously breaks rotational symmetry while preserving translational invariance. However, it has the distinguishing property of being odd under spatial inversion, which is allowed only in the presence of spin-orbit coupling. By examining the critical behavior of the multipolar nematic order parameter, we show that it drives the thermal phase transition near 200 K in Cd2Re2O7 and induces a parity-breaking lattice distortion as a secondary order parameter.

Questioning Questions: Elementary Teachers' Adaptations of Investigation Questions across the Inquiry Continuum

Science.gov (United States)

Biggers, Mandy

2018-01-01

Questioning is a central practice in science classrooms. However, not every question translates into a "good" science investigation. Questions that drive science investigations can be provided by many sources including the teacher, the curriculum, or the student. The variations in the source of investigation questions were explored in…

ALnS2:RE (A=K, Rb; Ln=La, Gd, Lu, Y): New optical materials family

International Nuclear Information System (INIS)

Jarý, V.; Havlák, L.; Bárta, J.; Mihóková, E.; Buryi, M.; Nikl, M.

2016-01-01

In the presented review paper, new potentially interesting material family, RE-doped ternary sulfides ALnS 2 (RE=Ce, Pr, Sm, Eu, Tb, Tm; A=Rb, K; Ln=La, Gd, Lu, Y) is discussed. Their synthesis is described and the structural and optical properties, characterized by methods of X-ray diffraction, time-resolved luminescence spectroscopy and electron paramagnetic resonance, are summarized and reviewed especially with respect to the influence of their composition. All samples discussed were synthesized in the form of transparent crystalline hexagonal platelets by chemical reaction under the flow of hydrogen sulfide. Their luminescence characteristics, including absorption, radioluminescence, photoluminescence excitation and emission spectra and decay kinetics, were measured and evaluated in a broad temperature (8–800 K) and concentration (0.002–20% of dopants) range. The application potential of mentioned compounds in the field of white LED solid state lightings or X-ray phosphors is thoroughly discussed. - Highlights: • RE-doped ALnS 2 (A=K, Rb; Ln=La, Gd, Lu, Y) were synthesized. • Their optical characteristics are summarized. • Concentration and temperature dependences of luminescence features investigated. • EPR technique is employed to explain Eu 2+ incorporation into KLuS 2 host. • The application potential in white LED and X-ray phosphors is discussed.

Photoluminescence properties of aeschynite-type LaNbTiO6:RE3+ (RE = Tb, Dy, Ho) down-converting phosphors.

Science.gov (United States)

Ma, Qian; Lu, Mengkai; Yang, Ping; Zhang, Aiyu; Cao, Yongqiang

2014-06-01

In this study, a series of LaNbTiO6:RE(3+) (RE = Tb, Dy, Ho) down-converting phosphors were synthesized using a modified sol-gel combustion method, and their photoluminescence (PL) properties were investigated as a function of activator concentration and annealing temperature. The resultant particles were characterized using X-ray diffraction, transmission electron microscopy, scanning electron microscopy, UV/Vis diffuse reflectance spectroscopy and PL spectra. The highly crystalline LaNbTiO6:RE(3+) (RE = Tb, Dy, Ho) phosphors with an average size of 200-300 nm obtained at 1100°C have an orthorhombic aeschynite-type structure and exhibit the highest luminescent intensity in our study range. The emission spectra of LaNbTiO6:RE(3+) (RE = Tb, Dy, Ho) phosphors under excitations at UV/blue sources are mainly composed of characteristic peaks arising from the f-f transitions of RE(3+), including 489 nm ((5) D4 → (7) F6) and 545 nm ((5) D4 → (7) F5) for Tb(3+), 476 and 482 nm ((4) F9/2 → (6) H15/2) and 571 nm ((4) F9/2 → (6) H13/2) for Dy(3+), and 545 nm ((5) F4 + (5) S2 → (5) I8) for Ho(3+), respectively. The luminescent mechanisms were further investigated. It can be expected that these phosphors are of intense interest and potential importance for many optical applications. Copyright © 2013 John Wiley & Sons, Ltd.

Pyrazole complexes of rhenium. Synthesis and crystal structure of trans-[Re(O)(OMe)L4]Br2 · L · 4H2O (L - 3,5-dimethylpyrazole)

International Nuclear Information System (INIS)

Sokolov, M.N.; Fedorova, N.Eh.; Fedorov, V.E.; Virovets, A.V.; Nun'es, P.

2002-01-01

The first rhenium (V) mononuclear complex featuring composition [Re(O)(OMe)L 4 ]Br 2 (L = 3,5-dimethylpyrazole), which is resistant to hydrolysis in neutral aqueous solution, along with its molecular adduct of the composition [Re(O)(OMe)L 4 ]Br 2 · L · 4H 2 O were synthesized. The reaction products were characterized by the methods of elementary analysis, absorption spectroscopy in visible, UV and IR ranges, mass spectrometry. Besides, the adduct structure was studied by the method of X-ray diffraction analysis. It was ascertained that the adduct is crystallized in tetragonal crystal system with unit cell parameters as follows: a = 14.912 (3), c = 17.108 (4) A, sp. gr. I4/m, Z = 4. In the complex molecule linear grouping Re(O)(OMe)] 2+ (Re-O-C angle being equal to 180 deg) is coordinated by four L ligand molecules [ru

Study on the preparation and stability of 188Re biomolecules via EHDP

International Nuclear Information System (INIS)

Ferro-Flores, G.; Garcia-Salinas, L.; Paredes-Gutierrez, L.; Hashimoto, K.; Melendez-Alafort, L.; Murphy, C.A.

2001-01-01

A direct labelling technique via ethane-1-hydroxy-1,1-diphosphonic acid (EHDP) as a weak competing ligand was developed for the preparation of several biomolecules: 188 Re-monoclonal antibody ior cea1 against carcinoembryonic antigen ( 188 Re-MoAb), biotinylated 188 Re-MoAb ( 188 Re-MoAb-biotin), 188 Re-polyclonal IgG ( 188 Re-IgG), 188 Re-peptide (somatostatine analogue peptide b-(2-naphtyl)-D-Ala-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-amide), 188 Re-MoAb fragments ( 188 Re-F(ab') 2 ) and biotinylated 188 Re-F(ab') 2 ( 188 Re-F(ab') 2 -biotin). The reaction conditions such as pH, temperature, weak ligand concentration and stannous chloride concentration were optimized during the radiolabelling of each biomolecule. Before the labelling procedure, disulphide bridge groups of the biomolecules were reduced with 2-mercaptoethanol (2-ME). To obtain 188 Re labelled antibodies and peptides in high radiochemical yields (>90%) via EHDP, it was necessary to use acidic conditions and a high concentration of stannous chloride to allow the redox reaction Re +7 →Re +5 :Re +4 . The labelling of MoAb and F(ab') 2 with 188 Re via EHDP was also evaluated employing a pretargeted technique by avidin-biotin strategy in normal mice, demonstrating that the 188 Re-labelled biotinylated antibodies are stable complexes in vivo. The 188 Re-peptide complex prepared by this method, was stable for 24 h and no radiolytic degradation was observed. (author)

The RELixSn2 (RE=La–Nd, Sm, and Gd; 0≤x<1) series revisited. Synthesis, crystal chemistry, and magnetic susceptibilities

International Nuclear Information System (INIS)

Makongo, Julien P.A.; Suen, Nian-Tzu; Guo, Shengping; Saha, Shanta; Greene, Richard; Paglione, Johnpierre; Bobev, Svilen

2014-01-01

This study is concerned with the ternary compounds RELi x Sn 2 (RE=La–Nd, Sm, and Gd; 0≤x 2 phases. These materials crystallize with the base-centered orthorhombic space group Cmcm (No. 63), and can be formally assigned with the CeNiSi 2 structure type (Pearson symbol oC16). Our systematic single-crystal X-ray diffraction studies revealed substantial Li-deficiencies in all cases, with SmSn 2 (space group Cmmm, ZrGa 2 structure type, Pearson symbol oC12) and GdSn 2 (space group Cmcm, ZrSi 2 structure type, Pearson symbol oC12) being completely lithium-free. The structure refinements also uncovered positional disorder on the Sn site neighboring the vacancies. The Sn-disorder and the Li-deficiency correlate, and vary monotonically with the decreased size of the rare-earth atoms in the order RE=La–Nd. The SmSn 2 and GdSn 2 structures are devoid of any disorder. Temperature-dependent studies of the magnetic response of the title compounds are also presented and discussed. -- Graphical abstract: RELi x Sn 2 (RE=La–Nd, 0≤x 2 structure type (a). The Sn-disorder and the Li-deficiency correlate, and vary monotonically with the decreased size of the rare-earth atoms in the order RE=La–Nd. The SmSn 2 (b) and GdSn 2 (c) structures are devoid of any disorder. Highlights: • The crystal structures of the RELi x Sn 2 (RE=La–Nd, 0≤x 2 structure type or defect variant of the CeNiSi 2 structure type. • SmSn 2 is isotypic with the ZrGa 2 structure, while RESn 2 (RE=Gd–Lu) are isotypic with the ZrSi 2 structure

Structure and Chemical Bonding of the Li-Doped Polar Intermetallic RE2In1−xLixGe2 (RE = La, Nd, Sm, Gd; x = 0.13, 0.28, 0.43, 0.53 System

Directory of Open Access Journals (Sweden)

Junsu Lee

2018-03-01

Full Text Available Four polar intermetallic compounds belonging to the RE2In1−xLixGe2 (RE = La, Nd, Sm, Gd; x = 0.13(1, 0.28(1, 0.43(1, 0.53(1 system have been synthesized by the traditional solid-state reaction method, and their crystal structures have been characterized by single-crystal X-ray diffraction (SXRD analyses. The isotypic crystal structures of four title compounds adopt the Mo2FeB2-type structure having the tetragonal space group P4/mbm (Z = 2, Pearson code tP40 with three crystallographically independent atomic sites and can be simply described as a pile of the identical 2-dimensioanl (2D RE2In1-xLixGe2 slabs stacked along the c-axis direction. The substituting Li atom shows a particular site preference for replacing In at the Wyckoff 2a site rather than Ge at the Wyckoff 4g in this crystal structure. As the size of a used rare-earth metal decreases from La3+ to Gd3+ throughout the title system, the Ge-Ge and Ge-In/Li bond distances, both of which consist of the 2D anionic Ge2(In/Li layer, gradually decrease resulting in the reduction of a unit cell volume. A series of theoretical investigations has been performed using a hypothetical structure model Gd2In0.5Li0.5Ge2 by tight-binding linear muffin-tin orbital (TB-LMTO method. The resultant densities of states (DOS value at the Fermi level (EF suggests a metallic conductivity for this particular composition, and this calculation result is in a good agreement with the formal charge distribution assigning two extra valence electrons for a metal-metal bond in the conduction band. The thorough analyses of six crystal orbital Hamilton population (COHP curves representing various interatomic interactions and an electron localization function (ELF diagram indicating the locations of paired-electron densities are also provided in this article.

Tuning of Hidden Order and Superconductivity in URu2Si2 by Applied Pressure and Re Substitution

International Nuclear Information System (INIS)

Nicholas P. Butch; Jason R. Jeffries; Benjamin T. Yukich; M. Brian Maple

2006-01-01

Single crystals of URu2-xRexSi2 have been grown via the Czochralski technique. Detailed electrical transport studies under pressure on single crystals of URu2Si2 confirm that the zero- temperature critical field is suppressed smoothly towards an extrapolated critical pressure of 15 kbar, which also corresponds to the accepted critical pressure of the hidden order phase. Improving on previous work on polycrystalline samples, studies of single crystals of URu2-xRexSi2 have provided more precise tracking of the suppression of both the hidden order phase at low doping and the ferromagnetic phase at intermediate Re concentrations

Growth of Sr2CrReO6 epitaxial thin films by pulsed laser deposition

International Nuclear Information System (INIS)

Orna, J.; Morellon, L.; Algarabel, P.A.; Pardo, J.A.; Magen, C.; Varela, M.; Pennycook, S.J.; De Teresa, J.M.; Ibarra, M.R.

2010-01-01

We report the growth, structural, magnetic, and electrical transport properties of epitaxial Sr 2 CrReO 6 thin films. We have succeeded in depositing films with a high crystallinity and a relatively large cationic order in a narrow window of growth parameters. The epitaxy relationship is Sr 2 CrReO 6 (SCRO) (0 0 1) [1 0 0]-parallel SrTiO 3 (STO) (0 0 1) [1 1 0] as determined by high-resolution X-ray diffraction and scanning transmission electron microscopy (STEM). Typical values of saturation magnetization of M S (300 K)=1 μ B /f.u. and ρ (300 K)=2.8 mΩ cm have been obtained in good agreement with previous published results in sputtered epitaxial thin films. We estimate that the antisite defects concentration in our thin films is of the order of 14%, and the measured Curie temperature is T C =481(2) K. We believe these materials be of interest as electrodes in spintronic devices.

Answers to frequently asked questions about cleanup activities at Three Mile Island, Unit 2

International Nuclear Information System (INIS)

1984-03-01

This question-and-answer report provides answers in nontechnical language to frequently asked questions about the status of cleanup activities at Three Mile Island, Unit 2. The answers update information first prepared in 1981, shortly after the cleanup got under way. Since then, a variety of important developments in the cleanup has occurred. The information in the report should be read in conjunction with NUREG 1060, a discussion of increased occupational exposure estimates for the cleanup. The questions and answers in this report cover purpose and community involvement, decontamination of water and reactor, fuel removal, radwaste transport, environmental impact, social and economic effects, worker exposures and safety, radiation monitoring, potential for accidents, and schedule and funding

Rhetorical questions or rhetorical uses of questions?

Directory of Open Access Journals (Sweden)

Špago Džemal

2016-12-01

Full Text Available This paper aims to explore whether some rhetorical questions contain certain linguistic elements or forms which would differentiate them from answer-eliciting and action-eliciting questions, and thereby hint at their rhetorical nature even outside the context. Namely, despite the fact that the same questions can be rhetorical in one context, and answer-eliciting in another, some of them are more likely to be associated with rhetorical or non-rhetorical use. The analysis is based on extensive data (over 1200 examples of rhetorical questions taken from 30 plays by two British and two American writers, and the results are expected to give an insight into whether we can talk about rhetorical questions or just a rhetorical use of questions.

Microstructural analysis of the creep resistance of die-cast Mg-4Al-2RE alloy

Energy Technology Data Exchange (ETDEWEB)

Zhu, S.M. [CAST CRC, Department of Materials Engineering, Monash University, Victoria 3800 (Australia)], E-mail: suming.zhu@eng.monash.edu.au; Gibson, M.A. [CAST CRC, CSIRO Materials Science and Engineering, Private Bag 33, Clayton South MDC, Clayton, Victoria 3169 (Australia); Nie, J.F.; Easton, M.A. [CAST CRC, Department of Materials Engineering, Monash University, Victoria 3800 (Australia); Abbott, T.B. [Advanced Magnesium Technologies, Milton, Queensland 4064 (Australia)

2008-03-15

The microstructure and microstructural stability of die-cast AE42 (Mg-4Al-2RE) alloy were investigated by transmission electron microscopy. It is shown that the formation of Mg{sub 17}Al{sub 12} after ageing at 200 deg. C is not due to the decomposition of A1{sub 11}RE{sub 3} as reported in the literature, but, rather, is associated with the supersaturation of Al solute in the {alpha}-Mg matrix. The level of Al solute retained in the {alpha}-Mg matrix after die-casting is suggested to be an important factor in influencing creep resistance.

Coherent Control of Nanoscale Ballistic Currents in Transition Metal Dichalcogenide ReS2.

Science.gov (United States)

Cui, Qiannan; Zhao, Hui

2015-04-28

Transition metal dichalcogenides are predicted to outperform traditional semiconductors in ballistic devices with nanoscale channel lengths. So far, experimental studies on charge transport in transition metal dichalcogenides are limited to the diffusive regime. Here we show, using ReS2 as an example, all-optical injection, detection, and coherent control of ballistic currents. By utilizing quantum interference between one-photon and two-photon interband transition pathways, ballistic currents are injected in ReS2 thin film samples by a pair of femtosecond laser pulses. We find that the current decays on an ultrafast time scale, resulting in an electron transport of only a fraction of one nanometer. Following the relaxation of the initially injected momentum, backward motion of the electrons for about 1 ps is observed, driven by the Coulomb force from the oppositely moved holes. We also show that the injected current can be controlled by the phase of the laser pulses. These results demonstrate a new platform to study ballistic transport of nonequilibrium carriers in transition metal dichalcogenides.

Re-use of disposable coil dialysers

International Nuclear Information System (INIS)

Abbud Filho, M.

1980-01-01

Re-use of disposable dialysers has been in practice for over 16 years throughout the world but it still is a polemical subject. The main justification for it is the reduction of costs in the hemodialytic treatment. We evaluated the technique of re-use that we adopt by studying 33 patients who should re-utilize coil dialysers for 8 consecutive hemodialysis sessions. We investigated: 1) small and middle molecules clearances trough a radioisotopic method; 2) the integrity of the system regarding bacterial invasion; 3) the frequency of anti-N antibodies; 4) aspects of scanning electron microscopy (SEM) of dialysis membrane after re-use. We observed no changes in the dialysers performance during re-use. We conclude that the re-use of dialyzers is feasible, without risks for the patients, allowing marked reduction of costs, thus making possible to offer treatment to a larger number of uremic patients. (author)

Shear-induced structural transformation and plasticity in ultraincompressible ReB2 limit its hardness

Czech Academy of Sciences Publication Activity Database

Zhang, R. F.; Legut, Dominik; Niewa, R.; Argon, A. S.; Veprek, S.

2010-01-01

Roč. 82, č. 10 (2010), 104104/1-104104/7 ISSN 1098-0121 Institutional research plan: CEZ:AV0Z20410507 Keywords : ReB2 * ab initio * ultrahard * shear-induced transformation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.772, year: 2010

Variations in the use of emergency PCI for the treatment of re-infarction following intravenous fibrinolytic therapy: impact on outcomes in HERO-2.

Science.gov (United States)

Edmond, J J; French, J K; Aylward, P E G; Wong, C K; Stewart, R A H; Williams, B F; De Pasquale, C G; O'connell, R L; Van den Berg, K; Van de Werf, F J; Simes, R J; White, H D

2007-06-01

Patients who suffer re-infarction during initial hospitalization for ST-elevation myocardial infarction (STEMI) have decreased survival compared to patients without re-infarction, so treatment of re-infarction may influence survival. To determine whether the utilization of reperfusion therapies varied within 12 h of re-infarction and was associated with 30-day mortality, we studied 552 patients with re-infarction of 17,073 patients with STEMI enrolled in HERO-2 in five regions (Russia, Eastern Europe, Western Countries, Asia, and Latin America). Patients presenting within 6 h of symptom-onset were randomized to receive either bivalirudin or unfractionated heparin intravenously just prior to streptokinase. Re-infarction occurred in 2.8 and 3.6% of bivalirudin and heparin treated patients, respectively (P = 0.004), but treatment assignment did not influence mortality after re-infarction. Patients with re-infarction had a higher 30-day mortality than those without re-infarction (24 vs. 10%; P model). Within 12 h of re-infarction, fibrinolytic therapy was administered to 12.0 and 8.2% underwent percutaneous coronary intervention (PCI); these two treatments were more frequently utilized in patients from Western countries (n = 112), compared to patients from other countries (n = 440) (34.8 and 16.1% compared to 6.1 and 6.1%, respectively, P < 0.001). Mortality was 15% in patients receiving reperfusion therapy for re-infarction and 27% for those with conservative management, hazard ratio (HR) 0.53 (95% CI 0.32-0.88), P = 0.01. In multiple Cox regression analysis which included adjustment for clinical variables and randomized treatment assignment, 30-day mortality after re-infarction varied by region (highest Latin America 29%, lowest Western countries 15%; P = 0.01). Other independent prognostic factors included age, time from randomization to re-infarction, and Killip class at randomization. The HR for PCI treatment of re-infarction was 0.18 [(95% CI 0.04-0.76), P = 0

Re-irradiation for abdominal tumor. Preliminary results

International Nuclear Information System (INIS)

Narisada, Hiroyuki; Imada, Hajime; Tomoda, Yoshinori

2012-01-01

The purpose of this study was to assess the efficacy of loco-regional radiotherapy for recurrent abdominal tumor treated with re-irradiation. Re-irradiated areas of 16 patients were eight of pelvic space, five of retroperitonium and three of liver or porta hepatica. Eligibility criteria of re-irradiation were success of initial irradiation, no other effective treatment except re-irradiation, constancy of bowel gas at hunger status and respiratory movement, visceral dosage reduction at re-irradiation. Total dose of initial, second course of radiation were 51.3±10.8 Gy, 50.6±14.2 Gy, respectively. Interval of initial and second course of radiation were 16.6±10.2 months. Local control after second course of radiation was four cases of complete response, five of partial response and seven of stable disease. Median survival periods were 55 months after initial treatment and 28 months after second course of radiation. In two cases of pelvic reirradiation, skin to pelvic space fistula was occurred. Re-irradiation for abdominal tumor may become useful salvage treatment. (author)

Photoresponse Enhancement in Monolayer ReS2 Phototransistor Decorated with CdSe-CdS-ZnS Quantum Dots.

Science.gov (United States)

Qin, Jing-Kai; Ren, Dan-Dan; Shao, Wen-Zhu; Li, Yang; Miao, Peng; Sun, Zhao-Yuan; Hu, PingAn; Zhen, Liang; Xu, Cheng-Yan

2017-11-15

ReS 2 films are considered as a promising candidate for optoelectronic applications due to their direct band gap character and optical/electrical anisotropy. However, the direct band gap in a narrow spectrum and the low absorption of atomically thin flakes weaken the prospect for light-harvesting applications. Here, we developed an efficient approach to enhance the performance of a ReS 2 -based phototransistor by coupling CdSe-CdS-ZnS core-shell quantum dots. Under 589 nm laser irradiation, the responsivity of the ReS 2 phototransistor decorated with quantum dots could be enhanced by more than 25 times (up to ∼654 A/W) and the rising and recovery time can be also reduced to 3.2 and 2.8 s, respectively. The excellent optoelectronic performance is originated from the coupling effect of quantum dots light absorber and cross-linker ligands 1,2-ethanedithiol. Photoexcited electron-hole pairs in quantum dots can separate and transfer efficiently due to the type-II band alignment and charge exchange process at the interface. Our work shows that the simple hybrid zero- and two-dimensional hybrid system can be employed for photodetection applications.

Periodic safety re-evaluations in NPPs in EC member states, Finland and Sweden

International Nuclear Information System (INIS)

1990-01-01

The work on periodic safety re-evaluations summarized in this report was performed by a Task Force of the CEC Working Group on the Safety of Thermal Reactors. The periodic safety re-evaluations under review in this study were those that are carried out in addition to other reviews which represent the primary means of safety assurance. The periodic safety re-evaluation is broader and more comprehensive in nature. The cumulative effects of experience (national and international), advances in knowledge and analysis techniques, improvements in safety standards and operating practices, overall effects of plant ageing, and the totality of all modifications over the period in question need to be taken into account. All countries have recognized the value of such periodic reviews, and licensees, either as a regulatory requirement or as a voluntary action, are carrying them out. The scope and contents of each country's review showed many similarities of approach, any differences being explained by the age and type of reactor in operation. Many similarities emerged in the topics selected for re-evaluation and in the approach to re-evaluation itself. The overall conclusion was that while approaches may differ in some respects, for practical purposes comparable levels of safety are achieved in the periodic safety re-evaluation of nuclear power plants

Defect chemistry, thermomechanical and transport properties of (RE₂ - _xSr_x)_0.98(Fe_0.8Co_0.2)_{1 - y}Mg_yO_{4 - δ} (RE = La, Pr)

DEFF Research Database (Denmark)

Chatzichristodoulou, Christodoulos; Schönbeck, C.; Hagen, Anke

2013-01-01

The oxygen nonstoichiometry of Ruddlesden-Popper compounds with chemical composition (RE2 - xSrx)0.98(Fe 0.8Co0.2)1 - yMgyO 4 - δ (RE = La, Pr, x = 0.9-1.2 and y = 0, 0.2) was measured as a function of temperature and oxygen activity (aO2) by coulometric titration and thermogravimetry. All...

BIFOCAL STEREO FOR MULTIPATH PERSON RE-IDENTIFICATION

Directory of Open Access Journals (Sweden)

G. Blott

2017-11-01

Full Text Available This work presents an approach for the task of person re-identification by exploiting bifocal stereo cameras. Present monocular person re-identification approaches show a decreasing working distance, when increasing the image resolution to obtain a higher reidentification performance. We propose a novel 3D multipath bifocal approach, containing a rectilinear lens with larger focal length for long range distances and a fish eye lens of a smaller focal length for the near range. The person re-identification performance is at least on par with 2D re-identification approaches but the working distance of the approach is increased and on average 10% more re-identification performance can be achieved in the overlapping field of view compared to a single camera. In addition, the 3D information is exploited from the overlapping field of view to solve potential 2D ambiguities.

Synthesis of a '4+1' Re(V) complex from Re(III), and its ...

African Journals Online (AJOL)

bis(2-hydroxybenzyl)-2-(2-aminoethyl)dimethylamine) was prepared from the oxidation of [ReCl3(MeCN)(PPh3)2] by dioxygen in the presence of H2had in ethanol. This reaction was done under reflux conditions for a relatively short reaction ...

Biomolecule labelling by 186 Re

International Nuclear Information System (INIS)

Lungu, Valeria Viorica; Mihailescu, Gabriela; Dumitrescu, Gabriela

1998-01-01

The aim of this study is to develop and improve the existing radiolabelling techniques of peptides and monoclonal antibodies with 186 Re and 188 Re as potential agents for cancer targeted radiotherapy. We selected the following methods and techniques for direct labelling of peptides and monoclonal antibody: 1. Prereduction of -S-S- bridges of biomolecule to sulfhydryls using reducing agents: ascorbic acid, cysteine, active hydrogen, 2,3 dimercaptopropanol. The prereduction reactions are controlled by massic ratios of reduction agents/biomolecule, pH, temperature and time of incubation; 2. Reduction of 186 Re O 4 - stannous chloride in acid and alkaline pH; 3. Coupling reaction of 186 Re (red) with the biomolecule controlled by the time and temperature of incubation, the influence of pH regarding the binding of 186 Re to the biomolecules. The quality control was effected by chromatography techniques (paper and elution gel chromatography) on labeled biomolecule before and after purification. The elution gel chromatography was spectrophotometricaly monitored at 280 nm. In the same time the radioactivity of samples was measured using a gamma counter. All the results confirm in vitro stability of labeled biomolecule. The biological evaluation studies regarding accumulation and biological affinity will be controlled by scintigraphy method. Biodistribution studies will be effected to Walker tumor bearing animals at 4 and 24 hours after injections. (authors)

Magneto-structural correlations in a family of Fe(II)Re(IV)(CN)2 single-chain magnets: density functional theory and ab initio calculations.

Science.gov (United States)

Zhang, Yi-Quan; Luo, Cheng-Lin; Wu, Xin-Bao; Wang, Bing-Wu; Gao, Song

2014-04-07

Until now, the expressions of the anisotropic energy barriers Δξ and ΔA, using the uniaxial magnetic anisotropy D, the intrachain coupling strength J, and the high-spin ground state S for single-chain magnets (SCMs) in the intermediate region between the Ising and the Heisenberg limits, were unknown. To explore this relationship, we used density functional theory and ab initio methods to obtain expressions of Δξ and ΔA in terms of D, J, and S of six R4Fe(II)-Re(IV)Cl4(CN)2 (R = diethylformamide (1), dibutylformamide (2), dimethylformamide (3), dimethylbutyramide (4), dimethylpropionamide (5), and diethylacetamide (6)) SCMs in the intermediate region. The ΔA value for compounds 1-3 was very similar to the magnetic anisotropic energy of a single Fe(II), while the value of Δξ was predicted using the exchange interaction of Fe(II) with the neighboring Re(IV), which could be expressed as 2JSReSFe. Similar to compounds 1-3, the anisotropy energy barrier ΔA of compounds 4 and 5 was also equal to (Di - Ei)SFe(2), but the correlation energy Δξ was closely equal to 2JSReSFe(cos 98.4 - cos 180) due to the reversal of the spins on the opposite Fe(II). For compound 6, one unit cell of Re(IV)Fe(II) was regarded as a domain wall since it had two different Re(IV)-Fe(II) couplings. Thus, the Δξ of compound 6 was expressed as 4J″SRe1Fe1SRe2Fe2, where J″ was the coupling constant of the neighboring unit cells of Re1Fe1 and Re2Fe2, and ΔA was equal to the anisotropic energy barrier of one domain wall given by DRe1Fe1(S(2)Re1Fe1 - 1/4).

FUZZY INFERENCE SYSTEM MODELING FOR BED ACTIVE CARBON RE-GENERATION PROCESS (CO2 GAS FACTORY CASE

Directory of Open Access Journals (Sweden)

S. Febriana

2005-01-01

Full Text Available Bed active carbon is one of the most important materials that had great impact in determining level of impurities in production of CO2 gas. In this particular factory case, there is unavailability of standard duration time of heating and cooling and steam flow rate for the re-generation process of bed active carbon. The paper discusses the fuzzy inference system for modeling of re-generation process of bed active carbon to find the optimum setting parameter. The fuzzy inference system was build using real historical daily processing data. After validation process, surface plot analysis was performed to find the optimum setting. The result of re-generation parameter setting is 9-10 hours of heating process, 4.66-5.32 hours of cooling process, and 1500-2500 kg/hr of steam flow rate.

Processing and properties of large grain (RE)BCO

International Nuclear Information System (INIS)

Cardwell, D.A.

1998-01-01

The potential of high temperature superconductors to generate large magnetic fields and to carry current with low power dissipation at 77 K is particularly attractive for a variety of permanent magnet applications. As a result large grain bulk (RE)-Ba-Cu-O ((RE)BCO) materials have been developed by melt process techniques in an attempt to fabricate practical materials for use in high field devices. This review outlines the current state of the art in this field of processing, including seeding requirements for the controlled fabrication of these materials, the origin of striking growth features such as the formation of a facet plane around the seed, platelet boundaries and (RE) 2 BaCuO 5 (RE-211) inclusions in the seeded melt grown microstructure. An observed variation in critical current density in large grain (RE)BCO samples is accounted for by Sm contamination of the material in the vicinity of the seed and with the development of a non-uniform growth morphology at ∼4 mm from the seed position. (RE)Ba 2 Cu 3 O 7-δ (RE-123) dendrites are observed to form and bro[en preferentially within the a/b plane of the lattice in this growth regime. Finally, trapped fields in excess of 3 T have been reported in irr[iated U-doped YBCO and (RE) 1+x Ba 2-x Cu 3 O y (RE=Sm, Nd) materials have been observed to carry transport current in fields of up to 10 T at 77 K. This underlines the potential of bulk (RE)BCO materials for practical permanent magnet type applications. (orig.)

Interactive modeling-synthesis-characterization approach towards controllable in situ self-assembly of artificial pinning centers in RE-123 films

Science.gov (United States)

Wu, Judy; Shi, Jack

2017-10-01

Raising critical current density J c in high temperature superconductors (HTSs) is an important strategy towards performance-cost balanced HTS technology for commercialization. The development of strong nanoscale artificial pinning centers (APCs) in HTS, such as YBa2Cu3O7 or RE-123 in general, represents one of the most exciting progressions in HTS material research in the last decade. Significantly raised J c has been demonstrated in APC/RE-123 nanocomposites by enhanced pinning on magnetic vortices in magnetic fields towards that demanded in practical applications. Among other processes, strain-mediated self-organization has been explored extensively for in situ formation of the APCs based on fundamental physics design rules. The desire in controlling the morphology, dimension, orientation, and concentration of APCs has led to a fundamental question on how strains interact in determining APCs at a macroscopic scale. Answering this question demands an interactive modeling-synthesis-characterization approach towards a thorough understanding of fundamental physics governing the strain-mediated self-organization of the APCs in the APC/RE-123 nanocomposites. Such an understanding is the key for a leap forward from the traditionally empirical method to materials-by-design to enable an optimal APC landscape to be achieved in epitaxial films of APC/YBCO nanocomposites under a precise guidance of fundamental physics. The paper intends to provide a review of recent progress made in the controllable generation of APCs using the interactive modeling-synthesis-characterization approach. The emphasis will be given to the understanding so far achieved using such an approach on the collective effect of the strain field on the morphology, dimension, and orientation of APCs in epitaxial APC/RE-123 nanocomposite films.

CAT questions and answers

International Nuclear Information System (INIS)

1993-02-01

This document, prepared in February 1993, addresses the most common questions asked by APS Collaborative Access Teams (CATs). The answers represent the best judgment on the part of the APS at this time. In some cases, details are provided in separate documents to be supplied by the APS. Some of the answers are brief because details are not yet available. The questions are separated into five categories representing different aspects of CAT interactions with the APS: (1) Memorandum of Understanding (MOU), (2) CAT Beamline Review and Construction, (3) CAT Beamline Safety, (4) CAT Beamline Operations, and (5) Miscellaneous. The APS plans to generate similar documents as needed to both address new questions and clarify answers to present questions

Gate-tunable diode-like current rectification and ambipolar transport in multilayer van der Waals ReSe2/WS2 p-n heterojunctions.

Science.gov (United States)

Wang, Cong; Yang, Shengxue; Xiong, Wenqi; Xia, Congxin; Cai, Hui; Chen, Bin; Wang, Xiaoting; Zhang, Xinzheng; Wei, Zhongming; Tongay, Sefaattin; Li, Jingbo; Liu, Qian

2016-10-12

Vertically stacked van der Waals (vdW) heterojunctions of two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted a great deal of attention due to their fascinating properties. In this work, we report two important gate-tunable phenomena in new artificial vdW p-n heterojunctions created by vertically stacking p-type multilayer ReSe 2 and n-type multilayer WS 2 : (1) well-defined strong gate-tunable diode-like current rectification across the p-n interface is observed, and the tunability of the electronic processes is attributed to the tunneling-assisted interlayer recombination induced by majority carriers across the vdW interface; (2) the distinct ambipolar behavior under gate voltage modulation both at forward and reverse bias voltages is found in the vdW ReSe 2 /WS 2 heterojunction transistors and a corresponding transport model is proposed for the tunable polarity behaviors. The findings may provide some new opportunities for building nanoscale electronic and optoelectronic devices.

Hydrothermal synthesis, characterization, and luminescence of Ca_2B_2O_5:RE (RE = Eu"3"+, Tb"3"+, Dy"3"+) nanofibers

International Nuclear Information System (INIS)

Yang, Li; Wan, Yingpeng; Li, Yuze; Pu, Yinfu; Huang, Yanlin; Chen, Cuili; Seo, Hyo Jin

2016-01-01

Ca_2B_2O_5:RE (RE = Eu"3"+, Tb"3"+, Dy"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_2B_2O_5:RE (RE = Eu"3"+, Tb"3"+, Dy"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_2B_2O_5:Eu"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_2B_2O_5:Tb"3"+ nanofibers is green color (x = 0.29, y = 0.53) with the lifetime of 2.13 ms. However, Dy"3"+-doped Ca_2B_2O_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"3"+-, Tb"3"+-, Dy"3"+-doped Ca_2B_2O_5 nanofibers, respectively. It is suggested that Ca_2B_2O_5:RE (RE = Eu"3"+, Tb"3"+, Dy"3"+) nanofibers could be an efficient phosphor for lighting and display.

Existing reflection seismic data re-processing

International Nuclear Information System (INIS)

Higashinaka, Motonori; Sano, Yukiko; Kozawa, Takeshi

2005-08-01

This document is to report the results of existing seismic data re-processing around Horonobe town, Hokkaido, Japan, which is a part of the Horonobe Underground Research Project. The main purpose of this re-processing is to recognize the subsurface structure of Omagari Fault and fold system around Omagari Fault. The seismic lines for re-processing are TYHR-A3 line and SHRB-2 line, which JAPEX surveyed in 1975. Applying weathering static correction using refraction analysis and noise suppression procedure, we have much enhanced seismic profile. Following information was obtained from seismic re-processing results. TYHR-A3 line: There are strong reflections, dipping to the west. These reflections are corresponding western limb of anticline to the west side of Omagari Fault. SHRB-2 line: There are strong reflections, dipping to the west, at CDP 60-140, while there are reflections, dipping to the east, to the east side of CDP 140. These reflections correspond to the western limb and the eastern limb of the anticline, which is parallel to Omagari FAULT. This seismic re-processing provides some useful information to know the geological structure around Omagari Fault. (author)

Antenna Controller Replacement Software

Science.gov (United States)

Chao, Roger Y.; Morgan, Scott C.; Strain, Martha M.; Rockwell, Stephen T.; Shimizu, Kenneth J.; Tehrani, Barzia J.; Kwok, Jaclyn H.; Tuazon-Wong, Michelle; Valtier, Henry; Nalbandi, Reza;

Activity of RE/sub 2/O/sub 3/ in liquid La/sub 2/O/sub 3/-Al/sub 2/O/sub 3/-CaF/sub 2/ and Ce/sub 2/O/sub 3/-CaO-CaF/sub 2/ slags

International Nuclear Information System (INIS)

Changzhen, W.; Shuqing, Y.; Qieng, D.

1985-01-01

In the course of electro-slag refining, if the slag contains rare earth oxides, the amount of rare earth introduced to the steel depends on the composition of the slag and other conditions. The main aim of this investigation is to study the activity of RE/sub 2/O/sub 3/ in the electro-slags of various compositions. One is the La/sub 2/O/sub 3/-CaO-CaF/sub 2/ ternary slag system and the other is the Ce/sub 2/O/sub 3/-CaO-CaF/sub 2/ slag system. The iso-activity diagram for RE/sub 2/O/sub 3/ and the liquid boundary for slags system were estimated

Theoretical calculations of hardness and metallicity for multibond hexagonal 5d transition metal diborides with ReB2 structure

International Nuclear Information System (INIS)

Yang Jun; Gao Fa-Ming; Liu Yong-Shan

2017-01-01

The hardness, electronic, and elastic properties of 5d transition metal diborides with ReB 2 structure are studied theoretically by using the first principles calculations. The calculated results are in good agreement with the previous experimental and theoretical results. Empirical formulas for estimating the hardness and partial number of effective free electrons for each bond in multibond compounds with metallicity are presented. Based on the formulas, IrB 2 has the largest hardness of 21.8 GPa, followed by OsB 2 (21.0 GPa) and ReB 2 (19.7 GPa), indicating that they are good candidates as hard materials. (paper)

Can we share questions? Performance of questions from different question banks in a single medical school.

Science.gov (United States)

Freeman, Adrian; Nicholls, Anthony; Ricketts, Chris; Coombes, Lee

2010-01-01

To use progress testing, a large bank of questions is required, particularly when planning to deliver tests over a long period of time. The questions need not only to be of good quality but also balanced in subject coverage across the curriculum to allow appropriate sampling. Hence as well as creating its own questions, an institution could share questions. Both methods allow ownership and structuring of the test appropriate to the educational requirements of the institution. Peninsula Medical School (PMS) has developed a mechanism to validate questions written in house. That mechanism can be adapted to utilise questions from an International question bank International Digital Electronic Access Library (IDEAL) and another UK-based question bank Universities Medical Assessment Partnership (UMAP). These questions have been used in our progress tests and analysed for relative performance. Data are presented to show that questions from differing sources can have comparable performance in a progress testing format. There are difficulties in transferring questions from one institution to another. These include problems of curricula and cultural differences. Whilst many of these difficulties exist, our experience suggests that it only requires a relatively small amount of work to adapt questions from external question banks for effective use. The longitudinal aspect of progress testing (albeit summatively) may allow more flexibility in question usage than single high stakes exams.

Polynomial solutions of the Monge-Ampère equation

Energy Technology Data Exchange (ETDEWEB)

Aminov, Yu A [B.Verkin Institute for Low Temperature Physics and Engineering, National Academy of Sciences of Ukraine, Khar' kov (Ukraine)

2014-11-30

The question of the existence of polynomial solutions to the Monge-Ampère equation z{sub xx}z{sub yy}−z{sub xy}{sup 2}=f(x,y) is considered in the case when f(x,y) is a polynomial. It is proved that if f is a polynomial of the second degree, which is positive for all values of its arguments and has a positive squared part, then no polynomial solution exists. On the other hand, a solution which is not polynomial but is analytic in the whole of the x, y-plane is produced. Necessary and sufficient conditions for the existence of polynomial solutions of degree up to 4 are found and methods for the construction of such solutions are indicated. An approximation theorem is proved. Bibliography: 10 titles.

Answers to frequently asked questions about cleanup activities at Three Mile Island, Unit 2. Public information report

International Nuclear Information System (INIS)

1980-09-01

The document presents answers to frequently asked questions about plans for cleanup and decontamination activities at Three Mile Island, Unit 2. Answers to the questions asked are based on information in the NRC 'Draft Programmatic Environmental Impact Statement related to decontamination and disposal of radioactive wastes resulting from March 28, 1979, accident, Three Mile Island Nuclear Station, Unit 2' NUREG-0683

Online scheduling of 2-re-entrant flexible manufacturing systems

NARCIS (Netherlands)

Pinxten, J. van; Waqas, U.; Geilen, M.; Basten, T.; Somers, L.

2017-01-01

Online scheduling of operations is essential to optimize productivity of flexible manufacturing systems (FMSs) where manufacturing requests arrive on the fly. An FMS processes products according to a particular flow through processing stations. This work focusses on online scheduling of re-entrant

Fictions et interactions : les fictions artistiques et la question de l’espace

Directory of Open Access Journals (Sweden)

Bernard Guelton

2015-10-01

Full Text Available Dans cette courte présentation, je vais esquisser quelques questions sur les rapports possibles entre l’espace et la fiction puis je vais faire un aperçu sur l’évolution de la ligne de recherche Fictions et interactions. Dans la première partie, je vais aborder trois questions : 1 le rapport entre la fiction et l’espace des images, 2 les espaces immersifs et 3 trois exemples d’oeuvres artistiques et performatives qui mettent en jeu les espaces en réalités alternées. RESUMO Nessa curta apresentação, vou esboçar algumas questões sobre as relações possíveis entre o espaço e a ficção, depois farei um panorama da evolução da linha de pesquisa Fictions & Interactions (Ficções & Interações. Na primeira parte abordarei três questões: 1 a relação entre a ficção e a espacialidade das imagens; 2 os espaços imersivos; e 3 três exemplos de obras artísticas e performativas que põem em jogo a noção de espaço em realidades alternadas. PALAVRAS-CHAVE Ficção, espaço, imersão.

Electric Power Lines : Questions and Answers on Research into Health Effects.

Energy Technology Data Exchange (ETDEWEB)

United States. Bonneville Power Administration.

1994-05-01

Most people know that electric power lines, like the wiring in our homes, can cause serious electric shocks if we`re not careful. Many people also want to know whether the electric and magnetic fields (EMF) produced by power lines and other electrical devices cause health effects. The purpose of this booklet is to answer some common questions that the Bonneville Power Administration (BPA) receives about the possible effects of power lines on health. First, some basic electrical terms are defined, and electric and magnetic fields are debed. Next, answers are given to several questions about recent scientific studies. Some important information about electrical safety follows. We then describe how BPA is addressing public concerns about potential health effects of power lines. The last section tells you how to obtain more detailed information about the health and safety issues summarized in this booklet.

Complexation of 188Re-phosphonates: in vitro and in vivo studies

International Nuclear Information System (INIS)

Faintuch, B.L.; Muramoto, E.; Faintuch, S.

2003-01-01

MDP (methylenediphosphonate) and HEDP (hydroxyethylidene diphosphonate), both disphosphonates, and EDTMP (ethylenediamine tetramethylene phosphonic acid), a tetraphosphonate ligand, have been previously labeled with 188 Re for use in metastatic bone-pain palliation. The aim of this study was a comparison between the three complexes 188 Re-MDP, 188 Re-HEDP and 188 Re-EDTMP concerning the complexation conditions, in order to achieve maximum yield, stability and bone uptake. Methods: MDP was dissolved in water and HEDP and EDTMP were dissolved in NaOH 1 N followed by reduction of pH with HCl 1 N. To all mixtures stannous chloride and 188 ReO 4 - were added in a nitrogen atmosphere. The preparations were heated in boiling water bath for 15 min. Yield as well as radiochemical stability was estimated by ITLC. Different concentrations of phosphonates and stannous chloride were evaluated. Biodistribution studies in Swiss mice were done for the three 188 Re-phosphonates that presented the best radiochemical yield. The optimal ligand concentration for maximum complexation was 85.2 mM for MDP, 72.8 mM for HEDP and 45.8 mM for EDTMP. The best amount of SnCl 2 .2H 2 O was 1.5 mg/mL for 188 Re-HEDP and 1 mg/mL for both 188 Re-MDP and 188 Re-EDTMP. In these conditions the three complexes showed a complexation rate above 95%. Reasonable radiochemical stability for 24 hours was achieved by 188 Re-EDTMP when employing ascorbic acid. All products showed a great uptake by the kidneys. 188 Re-EDTMP had the greatest uptake by femur (3.1 ± 0.2% ID/g) followed by 188 Re-MDP (1.2 ± 0.1% ID/g) and 188 Re-HEDP (1.0 ± 0.1% ID/g), 4 hours post injection. 188 Re-EDTMP displayed a femur bone/muscle ratio of 28.5, 188 Re-MDP 4.9 and 188 Re-HEDP 4.9. In conclusion 188 Re-EDTMP demonstrated the best potential as a radiopharmaceutical for bone cancer pain relief, encouraging further dosimetric studies and clinical trials. (orig.)

Ten-year assessment of the 100 priority questions for global biodiversity conservation.

Science.gov (United States)

Jucker, Tommaso; Wintle, Bonnie; Shackelford, Gorm; Bocquillon, Pierre; Geffert, Jan Laurens; Kasoar, Tim; Kovacs, Eszter; Mumby, Hannah S; Orland, Chloé; Schleicher, Judith; Tew, Eleanor R; Zabala, Aiora; Amano, Tatsuya; Bell, Alexandra; Bongalov, Boris; Chambers, Josephine M; Corrigan, Colleen; Durán, América P; Duvic-Paoli, Leslie-Anne; Emilson, Caroline; da Silva, Jéssica Fonseca; Garnett, Emma E; Green, Elizabeth J; Guth, Miriam K; Hacket-Pain, Andrew; Hinsley, Amy; Igea, Javier; Kunz, Martina; Luke, Sarah H; Lynam, William; Martin, Philip A; Nunes, Matheus H; Ockendon, Nancy; Pavitt, Aly; Payne, Charlotte L R; Plutshack, Victoria; Rademacher, Tim T; Robertson, Rebecca J; Rose, David C; Serban, Anca; Simmons, Benno I; Emilson, Erik J S; Tayleur, Catherine; Wordley, Claire F R; Mukherjee, Nibedita

2018-06-20

In 2008, a group of conservation scientists compiled a list of 100 priority questions for the conservation of the world's biodiversity [Sutherland et al. (2009) Conservation Biology, 23, 557-567]. However, now almost a decade later, no one has yet published a study gauging how much progress has been made in addressing these 100 high-priority questions in the peer-reviewed literature. Here we take a first step toward re-examining the 100 questions and identify key knowledge gaps that still remain. Through a combination of a questionnaire and a literature review, we evaluated each of the 100 questions on the basis of two criteria: relevance and effort. We defined highly-relevant questions as those which - if answered - would have the greatest impact on global biodiversity conservation, while effort was quantified based on the number of review publications addressing a particular question, which we used as a proxy for research effort. Using this approach we identified a set of questions that, despite being perceived as highly relevant, have been the focus of relatively few review publications over the past ten years. These questions covered a broad range of topics but predominantly tackled three major themes: the conservation and management of freshwater ecosystems, the role of societal structures in shaping interactions between people and the environment, and the impacts of conservation interventions. We see these questions as important knowledge gaps that have so far received insufficient attention and may need to be prioritised in future research. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Interpretation of Genomic Data Questions and Answers

Science.gov (United States)

Simon, Richard

2008-01-01

Using a question and answer format we describe important aspects of using genomic technologies in cancer research. The main challenges are not managing the mass of data, but rather the design, analysis and accurate reporting of studies that result in increased biological knowledge and medical utility. Many analysis issues address the use of expression microarrays but are also applicable to other whole genome assays. Microarray based clinical investigations have generated both unrealistic hyperbole and excessive skepticism. Genomic technologies are tremendously powerful and will play instrumental roles in elucidating the mechanisms of oncogenesis and in devlopingan era of predictive medicine in which treatments are tailored to individual tumors. Achieving these goals involves challenges in re-thinking many paradigms for the conduct of basic and clinical cancer research and for the organization of interdisciplinary collaboration. PMID:18582627

When is a research question not a research question?

Science.gov (United States)

Mayo, Nancy E; Asano, Miho; Barbic, Skye Pamela

2013-06-01

Research is undertaken to answer important questions yet often the question is poorly expressed and lacks information on the population, the exposure or intervention, the comparison, and the outcome. An optimal research question sets out what the investigator wants to know, not what the investigator might do, nor what the results of the study might ultimately contribute. The purpose of this paper is to estimate the extent to which rehabilitation scientists optimally define their research questions. A cross-sectional survey of the rehabilitation research articles published during 2008. Two raters independently rated each question according to pre-specified criteria; a third rater adjudicated all discrepant ratings. The proportion of the 258 articles with a question formulated as methods or expected contribution and not as what knowledge was being sought was 65%; 30% of questions required reworking. The designs which most often had poorly formulated research questions were randomized trials, cross-sectional and measurement studies. Formulating the research question is not purely a semantic concern. When the question is poorly formulated, the design, analysis, sample size calculations, and presentation of results may not be optimal. The gap between research and clinical practice could be bridged by a clear, complete, and informative research question.

Anomalous Polarized Raman Scattering and Large Circular Intensity Differential in Layered Triclinic ReS2.

Science.gov (United States)

Zhang, Shishu; Mao, Nannan; Zhang, Na; Wu, Juanxia; Tong, Lianming; Zhang, Jin

2017-10-24

The Raman tensor of a crystal is the derivative of its polarizability tensor and is dependent on the symmetries of the crystal and the Raman-active vibrational mode. The intensity of a particular mode is determined by the Raman selection rule, which involves the Raman tensor and the polarization configurations. For anisotropic two-dimensional (2D) layered crystals, polarized Raman scattering has been used to reveal the crystalline orientations. However, due to its complicated Raman tensors and optical birefringence, the polarized Raman scattering of triclinic 2D crystals has not been well studied yet. Herein, we report the anomalous polarized Raman scattering of 2D layered triclinic rhenium disulfide (ReS 2 ) and show a large circular intensity differential (CID) of Raman scattering in ReS 2 of different thicknesses. The origin of CID and the anomalous behavior in polarized Raman scattering were attributed to the appearance of nonzero off-diagonal Raman tensor elements and the phase factor owing to optical birefringence. This can provide a method to identify the vertical orientation of triclinic layered materials. These findings may help to further understand the Raman scattering process in 2D materials of low symmetry and may indicate important applications in chiral recognition by using 2D materials.

Spontaneous growth of whiskers on RE-bearing intermetallic compounds of Sn-RE, In-RE, and Pb-RE

International Nuclear Information System (INIS)

Liu Meng; Xian Aiping

2009-01-01

A phenomenon of the whiskers growth on the bulk rare earth (RE)-intermetallic compounds of NdSn 3 , NdIn 3 , and LaPb 3 is reported. The whiskers formed spontaneously on all of the RE-intermetallic compounds after exposed to room ambience (21-28 deg. C/20-56% RH, relative humidity) for several days. Among the samples, the propensity of whisker growth for NdSn 3 is the strongest, on which the tin whiskers were flourishing and covered all of the surfaces after exposed to room ambience for 22 days; while LaPb 3 is the secondary and NdIn 3 is the last one. Observed by SEM, the whiskers were exhibited as different morphology, size, and number density. The XRD analysis confirms the existence of RE(OH) 3 after whiskers formed, also, the weight gain curve of the samples exposed to room ambience supports that a spontaneous chemical reaction of the RE-intermetallic compounds with water in room ambience takes place. In discussion, it is proposed that the fresh metal atoms released by the chemical reaction could be causative to result in nucleation and spontaneous growth of the whiskers, while the anisotropy of crystal structure could be a reason to understand the difference of the whisker growth behaviors between Sn and Pb.

Split Fermi Surfaces of the Spin-Orbit-Coupled Metal Cd2Re2O7 Probed by de Haas-van Alphen Effect

Science.gov (United States)

Matsubayashi, Yasuhito; Sugii, Kaori; Hirose, Hishiro T.; Hirai, Daigorou; Sugiura, Shiori; Terashima, Taichi; Uji, Shinya; Hiroi, Zenji

2018-05-01

The superconducting pyrochlore oxide Cd2Re2O7 shows a structural transition with inversion symmetry breaking (ISB) at Ts1 = 200 K. A recent theory [https://doi.org/10.1103/PhysRevLett.115.026401" xlink:type="simple">L. Fu, Phys. Rev. Lett. 115, 026401 (2015)] suggests that the origin is an electronic instability that leads to a multipolar order in the spin-orbit-coupled metal. To observe the Fermi surface of the low-temperature phase of Cd2Re2O7, we perform de Haas-van Alphen effect measurements by means of magnetic torque. In reference to a calculated band structure, the spin-split Fermi surfaces with large cyclotron masses of 5-9m0 are revealed. The splitting is suggested to be due to an antisymmetric spin-orbit coupling induced by ISB, the strength of which is estimated to be approximately 67 K, which is rather smaller than those of typical non-centrosymmetric metals.

Griffiths-like phase in high TC perovskite La2FeReO6 prepared in a controlled reducing atmosphere

Science.gov (United States)

Kaipamagalath, Aswathi; Palakkal, Jasnamol P.; Varma, Manoj R.

2018-05-01

The perovskite La2FeReO6 is prepared by solid-state reaction method. Calcination was done in a controlled reducing atmosphere. The structure of the compound is found to be orthorhombic with Pbnm space group. From the DC magnetic studies, the transition temperature (TC) of La2FeReO6 is found to be at 729 K. A Griffiths-like phase is present in the material with ferromagnetic short-range correlations above TC up to the Griffiths temperature TG = 863 K.

Beam test results of the first full-scale prototype of CMS RE 1/2 resistive plate chamber

International Nuclear Information System (INIS)

Ying Jun; Ban Yong; Ye Yanlin; Cai Jianxin; Qian Sijin; Wang Quanjin; Liu Hongtao

2005-01-01

The authors reported the muon beam test results of the first full-scale prototype of CMS RE 1/2 Resistive Plate Chamber (RPC). The bakelite surface is treated using a special technology without oil to make it smooth enough. The full scale RE 1/2 RPC with honeycomb supporting frame is strong and thin enough to be fitted to the limited space of CMS design for the inner Forward RPC. The muon beam test was performed at CERN Gamma Irradiation Facility (GIF). The detection efficiency of this full scale RPC prototype is >95% even at very high irradiation background. The time resolution (less than 1.2 ns) and spatial resolution are satisfactory for the muon trigger device in future CMS experiments. The noise rate is also calculated and discussed

Questions and Questioning Techniques: A View of Indonesian Students’ Preferences

Directory of Open Access Journals (Sweden)

Debora Tri Ragawanti

2009-01-01

Full Text Available This study investigated students’ preference on teacher’s questions and questionings techniques and more importantly on how they could facilitate or impede their learning. The results on teacher’s questioning techniques showed that random nomination was more preferred than pre-arranged format nomination. In addition, techniques of nominating volunteering students and of giving wait-time were disliked by most student-respondents. As for types of question, the yes/no question was favored by most of the respondents. Different from the yes/no question, the number of respondents leaning forward to the analysis question, questions about fact of life, and questions to state opinion did not show a significant difference from the number of those leaning against the same questions.

Calcium lignosulphonate: re-evaluation of relevant endpoints to re-confirm validity and NOAEL of a 90-day feeding study in rats.

Science.gov (United States)

Thiel, Anette; Braun, William; Cary, Maurice G; Engelhardt, Jeffery A; Goodman, Dawn G; Hall, William C; Romeike, Annette; Ward, Jerrold M

2013-08-01

A 90-day feeding study in Han/Wistar rats with calcium lignosulphonate was evaluated by the EFSA. The study was considered to be inadequate due to potentially impaired health status of the animals based upon a high incidence of minimal lymphoid hyperplasia in mesenteric/mandibular lymph nodes and Peyer's patches, and minimal lymphoid cell infiltration in the liver in all animals. The EFSA Panel further disagreed with the conclusion that the treatment-related observation of foamy histiocytosis in mesenteric lymph nodes was non-adverse and asked whether this observation would progress to something more adverse over time. A PWG was convened to assess the sections of lymph nodes, Peyer's patches and liver. In addition, all lymphoid tissues were re-examined. The clinical pathology and animal colony health screening data were re-evaluated. The question whether the foamy histiocytosis could progress to an adverse finding with increasing exposure duration was addressed by read-across. In conclusion, the animals on the 90-day feeding study were in good health, the study was adequate for safety evaluation, and the foamy histiocytes in the mesenteric lymph nodes were not considered adverse, but rather an adaptive response that was considered unlikely to progress to an adverse condition with time. The NOAEL was re-affirmed to be 2000 mg/kgbw/d. Copyright © 2013 Elsevier Inc. All rights reserved.

Adaptive prostate IGRT combining online re-optimization and re-positioning: a feasibility study

International Nuclear Information System (INIS)

Li Taoran; Zhu Xiaofeng; Lee, W Robert; Vujaskovic, Zeljko; Yin Fangfang; Wu, Q Jackie; Thongphiew, Danthai

2011-01-01

In prostate radiation therapy, inter-fractional organ motion/deformation has posed significant challenges on reliable daily dose delivery. To correct for this issue, off-line re-optimization and online re-positioning have been used clinically. In this paper, we propose an adaptive images guided radiation therapy (AIGRT) scheme that combines these two correction methods in an anatomy-driven fashion. The AIGRT process first tries to find a best plan for the daily target from a plan pool, which consists of the original CT plan and all previous re-optimized plans. If successful, the selected plan is used for daily treatment with translational shifts. Otherwise, the AIGRT invokes the re-optimization process of the CT plan for the anatomy of the day, which is afterward added to the plan pool as a candidate for future fractions. The AIGRT scheme is evaluated by comparisons with daily re-optimization and online re-positioning techniques based on daily target coverage, organs at risk (OAR) sparing and implementation efficiency. Simulated treatment courses for 18 patients with re-optimization alone, re-positioning alone and AIGRT shows that AIGRT offers reliable daily target coverage that is highly comparable to daily re-optimization and significantly improves from re-positioning. AIGRT is also seen to provide improved OAR sparing compared to re-positioning. Apart from dosimetric benefits, AIGRT in addition offers an efficient scheme to integrate re-optimization to current re-positioning-based IGRT workflow.

La presse française commente la question macédonienne à l’aube des guerres balkaniques

Directory of Open Access Journals (Sweden)

Nicolas Pitsos

2011-12-01

Full Text Available Comment la presse française, en trois familles idéologiques distinctes, présente la question macédonienne en 1912.L’objectif de cette communication est d’étudier comment la presse française aborda la question macédonienne au commencement de la première guerre balkanique. Une première catégorie de journaux (socialistes, syndicalistes, anarchistes, anticléricaux se prononce pour la paix et soutient soit le maintien du statu quo territorial, soit la création d’une fédération balkanique, en dénonçant en même temps le caractère expansionniste des projets des alliés balkaniques. Une deuxième catégorie (nationalistes de droite, antirépublicains adopte la rhétorique officielle des royaumes balkaniques qui justifiaient leur mobilisation au nom de la défense des droits de leurs coreligionnaires dans l’Empire ottoman et notamment en Macédoine. La plupart de ces plumes ont trempé d’une part dans la haine du Turc et du musulman et sont inspirées d’autre part, par leur volonté revancharde contre l’Allemagne qui aurait équipé l’armée ottomane alors que l’industrie française aurait doté les alliés balkaniques. Enfin, une dernière catégorie (catholiques, bonapartistes considère que le bouleversement du statu quo territorial au profit des royaumes orthodoxes serait préjudiciable pour les intérêts économiques et culturels français.French newspapers comment the Macedonian question at the dawn of the Balkan Wars.The aim of this paper is to study how the French newspapers dealt with the Macedonian question at the beginning of the Balkan Wars. A first group (socialists, trade-unionists, anarchists, anticlerical, backs up a peaceful settlement of the dispute and is in favor of the maintenance of the status quo or the creation of a Balkan federation. It is also denouncing the expansionist character of allies’ projects. A second group (right nationalists, antirepublicans adopts the official rhetoric of the

42 CFR 405.213 - Re-evaluation of a device categorization.

Science.gov (United States)

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Re-evaluation of a device categorization. 405.213... Decisions That Relate to Health Care Technology § 405.213 Re-evaluation of a device categorization. (a... experimental/investigational (Category A) may request re-evaluation of the categorization decision. (2) A...

Concentration of 188Re-Perrhenate for Therapeutic Radiopharmaceuticals

International Nuclear Information System (INIS)

Bokhari, T.H.; Hina, S.; Ahmad, M.; Iqbal, M.

2013-01-01

Summary: Rhenium-188 (T1/2=16.9h) has great potential for a variety of therapeutic applications, including radionuclide synovectomy, oncology and bone pain palliation. The radioactive concentration of 188Re is dependent upon the specific activity of 188W, which dictates the bed size of the alumina/gel column. Due to the high content of inactive tungsten in neutron irradiated WO3, large columns containing aluminum oxide or gel are needed to prepare to double neutron capture based 188W/188Re generators that results in large elution volumes containing relatively high188W contents and low concentrations of /sup 188/ ReO/sub 4/ This decrease in specific volume of 188ReO/sub 4/ places a limitation because a high radioactive concentration of 188ReO4 - is always needed for filling angioplasty balloons or other therapeutic radiopharmaceuticals like188Re -EHDP 188Re -EDTMP, 188Re - MAG3 and 188Re -DTPA. We report post elution concentration of 188ReO4 - using in- house prepared lead cation exchange and alumina columns. Using these columns high bolus volume (10 mL saline) of 188ReO4 - can conveniently be concentrated in 1 mL of physiological saline for therapeutic use. (author)

Spontaneous growth of whiskers on RE-bearing intermetallic compounds of Sn-RE, In-RE, and Pb-RE

Energy Technology Data Exchange (ETDEWEB)

Liu Meng [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Science, 72 Wenhua Road, Shenyang 110016 (China); Xian Aiping, E-mail: ap.xian@imr.ac.c [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Science, 72 Wenhua Road, Shenyang 110016 (China)

2009-11-03

A phenomenon of the whiskers growth on the bulk rare earth (RE)-intermetallic compounds of NdSn{sub 3}, NdIn{sub 3}, and LaPb{sub 3} is reported. The whiskers formed spontaneously on all of the RE-intermetallic compounds after exposed to room ambience (21-28 deg. C/20-56% RH, relative humidity) for several days. Among the samples, the propensity of whisker growth for NdSn{sub 3} is the strongest, on which the tin whiskers were flourishing and covered all of the surfaces after exposed to room ambience for 22 days; while LaPb{sub 3} is the secondary and NdIn{sub 3} is the last one. Observed by SEM, the whiskers were exhibited as different morphology, size, and number density. The XRD analysis confirms the existence of RE(OH){sub 3} after whiskers formed, also, the weight gain curve of the samples exposed to room ambience supports that a spontaneous chemical reaction of the RE-intermetallic compounds with water in room ambience takes place. In discussion, it is proposed that the fresh metal atoms released by the chemical reaction could be causative to result in nucleation and spontaneous growth of the whiskers, while the anisotropy of crystal structure could be a reason to understand the difference of the whisker growth behaviors between Sn and Pb.

Electric Power Lines : Questions and Answers on Research into Health Effects.

Energy Technology Data Exchange (ETDEWEB)

United States. Bonneville Power Administration.

1993-11-01

Most people know that electric power lines, like the wiring in our homes, can cause serious electric shocks if we`re not careful. Many people also want to know whether the electric and magnetic fields (EMF) produced by power lines and other electrical devices cause health effects. The purpose of this pamphlet is to answer some common questions that the Bonneville Power Administration (BPA) receives about the possible effects of power lines on health. (BPA is the Pacific Northwest`s Federal electric power marketing agency.) First, some basic electrical terms are defined, and electric and magnetic fields are described. Next, answers are given to several questions about recent scientific studies. We then describe how BPA is addressing public concerns raised by these studies. Some important information about electrical safety follows. The last section tells you how to obtain more detailed information about the health and safety issues summarized in this pamphlet.

Gentlemen, players and re-moralisation of banking:Solution or diversion?

OpenAIRE

Kerr, Ronald; Robinson, Sarah

2016-01-01

In this chapter, ‘A return to gentlemanly banking: re-moralisation as solution ordiversion?’ the authors focus on proposals for changes in institutional culture in the field of banking and finance in order to address issues of what has been called ‘shameful’ and ‘dishonourable’ behaviour by individual bankers. They pose the following questions: in what ways can ‘culture change’ be conceptualised and understood in the context of banking; and to what extent is such proposed change feasible in t...

Thermoelectric properties, crystal and electronic structure of semiconducting RECuSe2 (RE = Pr, Sm, Gd, Dy and Er)

International Nuclear Information System (INIS)

Esmaeili, Mehdi; Tseng, Yu-Chih; Mozharivskyj, Yurij

2014-01-01

Highlights: • Crystal and electronic structure of monoclinic and trigonal RECuSe 2 phases. • Thermoelectric properties of the RECuSe 2 phases. • Temperature stability of the RECuSe 2 phases. - Abstract: The ternary RECuSe 2 phases have been prepared and structurally characterized. They adopt either a monoclinic structure (P2 1 /c, z = 4) for lighter rare earths (RE = Pr, Sm and Gd) or Cu-disordered trigonal structure for heavier rare-earths (P3 ¯ m1, z = 1, RE = Dy and Er). The resistivity and Seebeck coefficient measurements on GdCuSe 2 , DyCuSe 2 and ErCuSe 2 indicate that the studied phases are p-type semiconductors with relatively small activation energies (0.045–0.11 eV). However, their electrical resistivities are too high (0.45–220 Ω cm at room temperature) to make them competitive thermoelectric materials. Electronic structure calculations indicate presence of a band gap in the RECuSe 2 phases

ions (RE = La, Pr, Nd, Sm, Gd and Dy)

Indian Academy of Sciences (India)

) zirconia), tendency of phase transformation (tetragonal to monoclinic () zirconia) and lattice strain were studied with mechanical property e.g. tensile strength of sol–gel derived ZrO2–2 mol% RE2O3 (RE = La, Pr, Nd, Sm, Gd and Dy) spun ...

Effect of two types of control questions and two question formats on the outcomes of polygraph examinations.

Science.gov (United States)

Horvath, Frank; Palmatier, John J

2008-07-01

Two major variations of polygraph "Control Question" testing, the Zone Comparison (ZoC) and the Modified General Question Test (MGQT) were evaluated. Within each, the type of control question, Exclusive or "time bar" (e.g., "Before you were 21, did you ever...") and Nonexclusive or "no time bar" (e.g., "Did you ever....?") was manipulated in a mock theft scenario, with 80 male and 40 female subjects randomly assigned to be either innocent or guilty. Polygraphic data collected by experienced field examiners were numerically scored by an evaluator blind to all aspects of the study. Decision accuracy was not related to the type of procedure (ZoC/MGQT) used or the subject's sex. Accuracy was significantly related to the type of control question [chi(2) (2) = 11.46, p = 0.003; tau c = 0.29]. Nonexclusive control questions produced greater accuracy than Exclusive control questions on both innocent and guilty subjects. These results and subjects' self-reports support the general "theory" on which control question (CQ) testing is based. The need for better empirical support of accepted dogma and current field practices is strongly indicated by these findings.

Design analysis of a Helium re-condenser

Science.gov (United States)

Muley, P. K.; Bapat, S. L.; Atrey, M. D.

2017-02-01

Modern helium cryostats deploy a cryocooler with a re-condenser at its II stage for in-situ re-condensation of boil-off vapor. The present work is a vital step in the ongoing research work of design of cryocooler based 100 litre helium cryostat with in-situ re-condensation. The cryostat incorporates a two stage Gifford McMahon cryocooler having specified refrigerating capacity of 40 W at 43 K for I stage and 1 W at 4.2 K for II stage. Although design of cryostat ensures thermal load for cryocooler below its specified refrigerating capacity at the second stage, successful in-situ re-condensation depends on proper design of re-condenser which forms the objective of this work. The present work proposes design of helium re-condenser with straight rectangular fins. Fins are analyzed for optimization of thermal performance parameters such as condensation heat transfer coefficient, surface area for heat transfer, re-condensing capacity, efficiency and effectiveness. The present work provides design of re-condenser with 19 integral fins each of 10 mm height and 1.5 mm thickness with a gap of 1.5 mm between two fins, keeping in mind the manufacturing feasibility, having efficiency of 80.96 % and effectiveness of 10.34.

Concurrent Engineering in Aerospace Industry: How To Achieve Radiofrequency Geometric Specifications in Satellite Antennae

Directory of Open Access Journals (Sweden)

J. Vargas

2000-01-01

Full Text Available One of the problems that a satellite manufacturing involves is to obtain the geometrical forms and the accurate positions for the different radiofrequency components (reflectors, subreflectors and feeders. CFRP (Carbon Fibber Reinforced Plastics sandwich structures never are obtained as designed due to the deformations associated to the manufacturing process. So, reflectors, subreflectors and structural components (towers, panels... have to be measured in order to include their deviations in the design of the regulation parts. High performance equipment (Co-ordinate Measurement Machines, CAD/CAM Systems and 5 Axis Machine Tool is used, but it is also necessary to make an integrated and multidisciplinary team. This paper describes how this process was implemented in CASA Space Division during HISPASAT 1C satellite manufacturing program.

Question popularity analysis and prediction in community question answering services.

Science.gov (United States)

Liu, Ting; Zhang, Wei-Nan; Cao, Liujuan; Zhang, Yu

2014-01-01

With the blooming of online social media applications, Community Question Answering (CQA) services have become one of the most important online resources for information and knowledge seekers. A large number of high quality question and answer pairs have been accumulated, which allow users to not only share their knowledge with others, but also interact with each other. Accordingly, volumes of efforts have been taken to explore the questions and answers retrieval in CQA services so as to help users to finding the similar questions or the right answers. However, to our knowledge, less attention has been paid so far to question popularity in CQA. Question popularity can reflect the attention and interest of users. Hence, predicting question popularity can better capture the users' interest so as to improve the users' experience. Meanwhile, it can also promote the development of the community. In this paper, we investigate the problem of predicting question popularity in CQA. We first explore the factors that have impact on question popularity by employing statistical analysis. We then propose a supervised machine learning approach to model these factors for question popularity prediction. The experimental results show that our proposed approach can effectively distinguish the popular questions from unpopular ones in the Yahoo! Answers question and answer repository.

Crystal structure of R.E. NiSn and R.E. PdSn equiatomic compounds

International Nuclear Information System (INIS)

Dwight, A.E.

1983-03-01

Call constants and volume per formula weight are tabulated for RE NiSn (RE = La to Lu, Y) and RE PdSn (RE = Nd to Ho). The unit cell constants are also plotted versus ionic radius of the RE; trends are noted

IDC Re-Engineering Phase 2 System Specification Document Version 1.5

Energy Technology Data Exchange (ETDEWEB)

Satpathi, Meara Allena [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Burns, John F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Harris, James M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-01-01

This document contains the system specifications derived to satisfy the system requirements found in the IDC System Requirements Document for the IDC Re-Engineering Phase 2 project. This System Specification Document (SSD) defines waveform data processing requirements for the International Data Centre (IDC) of the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO). The routine processing includes characterization of events with the objective of screening out events considered to be consistent with natural phenomena or non-nuclear, man-made phenomena. This document does not address requirements concerning acquisition, processing and analysis of radionuclide data but does include requirements for the dissemination of radionuclide data and products.

Kant's answer to the question 'what is man?' and its implications for anthropology.

Science.gov (United States)

Cohen, Alix A

2008-12-01

This paper examines Kant's anthropological project and its relationship to his conception of 'man' in order to show that Kant's answer to the question 'what is man?' entails a decisive re-evaluation of traditional conceptions of human nature. I argue that Kant redirects the question 'what is man?' away from defining man in terms of what he is, and towards defining him in terms of what he does, in particular through the distinction between three levels of what I will call 'man's praxis': the levels of technicality, prudence, and morality. As soon as man is understood in terms of what he makes of himself rather than in terms of what he is, two crucial issues arise: what is the purpose of his making? And how can he reach this destination? My claim is that whilst the first question is answered by ethics and a doctrine of prudence, the second question is answered by anthropology. In this sense, anthropology plays the crucial role of identifying the worldly helps and hindrances to the realisation of man's purposes--and this is the reason why it should be understood as a 'pragmatic' discipline.

76 FR 40403 - R.E. Ginna Nuclear Power Plant, LLC, R.E. Ginna Nuclear Power Plant, R.E. Ginna Independent Spent...

Science.gov (United States)

2011-07-08

... NUCLEAR REGULATORY COMMISSION [Docket No. 50-244; Docket No. 72-67] R.E. Ginna Nuclear Power Plant, LLC, R.E. Ginna Nuclear Power Plant, R.E. Ginna Independent Spent Fuel Storage Installation; Notice of... Facility Operating License No. DPR-18, for the R.E. Ginna Nuclear Power Plant (Ginna), currently held by R...

Robustness Analysis of Visual Question Answering Models by Basic Questions

KAUST Repository

Huang, Jia-Hong

2017-11-01

Visual Question Answering (VQA) models should have both high robustness and accuracy. Unfortunately, most of the current VQA research only focuses on accuracy because there is a lack of proper methods to measure the robustness of VQA models. There are two main modules in our algorithm. Given a natural language question about an image, the first module takes the question as input and then outputs the ranked basic questions, with similarity scores, of the main given question. The second module takes the main question, image and these basic questions as input and then outputs the text-based answer of the main question about the given image. We claim that a robust VQA model is one, whose performance is not changed much when related basic questions as also made available to it as input. We formulate the basic questions generation problem as a LASSO optimization, and also propose a large scale Basic Question Dataset (BQD) and Rscore (novel robustness measure), for analyzing the robustness of VQA models. We hope our BQD will be used as a benchmark for to evaluate the robustness of VQA models, so as to help the community build more robust and accurate VQA models.

Robustness Analysis of Visual Question Answering Models by Basic Questions

KAUST Repository

Huang, Jia-Hong

2017-01-01

Visual Question Answering (VQA) models should have both high robustness and accuracy. Unfortunately, most of the current VQA research only focuses on accuracy because there is a lack of proper methods to measure the robustness of VQA models. There are two main modules in our algorithm. Given a natural language question about an image, the first module takes the question as input and then outputs the ranked basic questions, with similarity scores, of the main given question. The second module takes the main question, image and these basic questions as input and then outputs the text-based answer of the main question about the given image. We claim that a robust VQA model is one, whose performance is not changed much when related basic questions as also made available to it as input. We formulate the basic questions generation problem as a LASSO optimization, and also propose a large scale Basic Question Dataset (BQD) and Rscore (novel robustness measure), for analyzing the robustness of VQA models. We hope our BQD will be used as a benchmark for to evaluate the robustness of VQA models, so as to help the community build more robust and accurate VQA models.

Two-Year-Old Children Differentiate Test Questions from Genuine Questions

Science.gov (United States)

Grosse, Gerlind; Tomasello, Michael

2012-01-01

Children are frequently confronted with so-called "test questions". While genuine questions are requests for missing information, test questions ask for information obviously already known to the questioner. In this study we explored whether two-year-old children respond differentially to one and the same question used as either a genuine question…

Physics 30 Program Machine-Scorable Open-Ended Questions: Unit 2: Electric and Magnetic Forces. Diploma Examinations Program.

Science.gov (United States)

Alberta Dept. of Education, Edmonton.

This document outlines the use of machine-scorable open-ended questions for the evaluation of Physics 30 in Alberta. Contents include: (1) an introduction to the questions; (2) sample instruction sheet; (3) fifteen sample items; (4) item information including the key, difficulty, and source of each item; (5) solutions to items having multiple…

Nuclear questions; Le nucleaire en questions

Energy Technology Data Exchange (ETDEWEB)

Berg, Eugene

2012-02-15

Civilian and military nuclear questions fill a multitude of publications these days, especially after the Japanese tsunami and the Fukushima disaster. The author analyses some of them and highlights the links between civil and military nuclear industries, the realities of the nuclear cycle and related industrial questions before concluding on the controversial issue of weapons and their proliferation potential

Re-irradiation of recurrent esophageal cancer after primary definitive radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Suk; Lee, Chang Geol; Kim, Kyung Hwan; Kim, Tae Hyung [Dept. of Radiation Oncology, Yonsei University Health System, Yonsei University College of Medicine, Seoul (Korea, Republic of)

2012-12-15

For recurrent esophageal cancer after primary definitive radiotherapy, no general treatment guidelines are available. We evaluated the toxicities and clinical outcomes of re-irradiation (re-RT) for recurrent esophageal cancer. We analyzed 10 patients with recurrent esophageal cancer treated with re-RT after primary definitive radiotherapy. The median time interval between primary radiotherapy and re-RT was 15.6 months (range, 4.8 to 36.4 months). The total dose of primary radiotherapy was a median of 50.4 Gy (range, 50.4 to 63.0 Gy). The total dose of re-RT was a median of 46.5 Gy (range, 44.0 to 50.4 Gy). The median follow-up period was 4.9 months (range, 2.6 to 11.4 months). The tumor response at 3 months after the end of re-RT was complete response (n = 2), partial response (n = 1), stable disease (n = 2), and progressive disease (n = 5). Grade 5 tracheoesophageal fistula developed in three patients. The time interval between primary radiotherapy and re-RT was less than 12 months in two of these three patients. Late toxicities included grade 1 dysphagia (n = 1). Re-RT of recurrent esophageal cancer after primary radiotherapy can cause severe toxicity.

Re-irradiation of recurrent esophageal cancer after primary definitive radiotherapy

International Nuclear Information System (INIS)

Kim, Young Suk; Lee, Chang Geol; Kim, Kyung Hwan; Kim, Tae Hyung

2012-01-01

For recurrent esophageal cancer after primary definitive radiotherapy, no general treatment guidelines are available. We evaluated the toxicities and clinical outcomes of re-irradiation (re-RT) for recurrent esophageal cancer. We analyzed 10 patients with recurrent esophageal cancer treated with re-RT after primary definitive radiotherapy. The median time interval between primary radiotherapy and re-RT was 15.6 months (range, 4.8 to 36.4 months). The total dose of primary radiotherapy was a median of 50.4 Gy (range, 50.4 to 63.0 Gy). The total dose of re-RT was a median of 46.5 Gy (range, 44.0 to 50.4 Gy). The median follow-up period was 4.9 months (range, 2.6 to 11.4 months). The tumor response at 3 months after the end of re-RT was complete response (n = 2), partial response (n = 1), stable disease (n = 2), and progressive disease (n = 5). Grade 5 tracheoesophageal fistula developed in three patients. The time interval between primary radiotherapy and re-RT was less than 12 months in two of these three patients. Late toxicities included grade 1 dysphagia (n = 1). Re-RT of recurrent esophageal cancer after primary radiotherapy can cause severe toxicity.

XPS investigations of tribolayers formed on TiN and (Ti,Re)N coatings

Energy Technology Data Exchange (ETDEWEB)

Oktay, Serkan; Kahraman, Zafer; Urgen, Mustafa; Kazmanli, Kursat, E-mail: kursat@itu.edu.tr

2015-02-15

Graphical abstract: - Highlights: • The (Ti,Re)N coating (8 ± 1.9 at.% Re) consisted of TiN and ReNx (x > 1.33) phases. • TiO{sub 2} provided low friction coefficient to TiN coating at 150 °C. • Re addition to TiN drastically dropped the friction coefficients to 0.17–0.22. • Re{sub 2}O{sub 7} provided very low friction coefficient to (Ti,Re)N coating. • Re addition to TiN improved the wear behavior. - Abstract: TiN and (Ti,Re)N coatings were deposited on high-speed-steel substrates by a hybrid coating system composed of cathodic arc PVD and magnetron sputtering techniques. In order to keep rhenium content low (8 ± 1.9 at.%) in the coating, magnetron sputtering technique was utilized to evaporate rhenium. The (Ti,Re)N coating consisted of TiN and ReN{sub x} (x > 1.33) phases. The hardness of TiN and (Ti,Re)N were 31 GPa and 29 GPa ( ± 2 GPa), respectively. Tribological behaviors of the samples were tested against Al{sub 2}O{sub 3} balls at 21 °C (RT) and 150 °C (HT) by reciprocating wear technique. The tribolayers were analyzed by XPS technique. Friction coefficients of TiN were 0.56, 0.35 for 21 °C and 150 °C tests, respectively. Rhenium addition to TiN drastically dropped the friction coefficients to 0.22 and 0.17 for RT and HT samples. Rhenium addition also improved the wear resistance of the coating at both test temperatures. For TiN, main oxide component of the tribolayers was Ti{sub 2}O{sub 3} for RT tests and TiO{sub 2} for HT tests. The oxide layer formed on (Ti,Re)N were the mixture of TiO{sub 2}, Ti−O−N, ReO{sub 2} and Re{sub 2}O{sub 7} for both test temperatures. Re{sub 2}O{sub 7} provided very low friction coefficient to (Ti,Re)N. The findings are consistent with the crystal chemistry approach.

Study of de-aggregation of mechanochemically synthesized ZnSe nanoparticles by re-milling in the presence of ZnCl2 solution

Directory of Open Access Journals (Sweden)

Marcela Achimovičová

2013-12-01

Full Text Available Conventional mechanochemical synthesis of zinc selenide, ZnSe nanoparticles was performed in a planetary ball mill by high-energy milling of zinc (Zn and selenium (Se powders. Mechanochemically synthesized ZnSe was subsequently re-milled in circulation mill in ZnCl2 solution in order to study de-aggregation, physical-chemical and optical properties of ZnSe nanoparticles. The mechanochemically synthesized and re-milled samples were characterized by X-ray diffraction analysis (XRD that confirmed the presence of cubic and hexagonal ZnSe phases. Size of crystallites calculated from XRD patterns has decreased from 50 to 19 nm for cubic ZnSe phase and from 145 to 2.5 nm for hexagonal ZnSe phase after re-milling for 110 min in ZnCl2 solution. Size, phase composition, morphology, and crystallinity of ZnSe nanoparticles were studied by transmission electron microscopy (TEM and selected area electron diffraction (SAED. UV-Vis optical spectroscopy has provided an evidence of blue shift of the re-milled nanocrystalline ZnSe particles from the direct band gap of 2.67 eV characteristic of bulk ZnSe crystals. Colloidal stability of ZnSe nanoparticles dispersions was studied by ? �potential measurements.

Answers to questions about removing krypton from the Three Mile Island, Unit 2 reactor building. Public information report

International Nuclear Information System (INIS)

1980-05-01

This document presents answers to frequently asked questions about the probable effects of controlled releases of the krypton presently contained within the reactor building of Three Mile Island, Unit 2. Also answered are questions about alternative means for removing the krypton

Answers to questions about updated estimates of occupational radiation doses at Three Mile Island, Unit 2

International Nuclear Information System (INIS)

1983-12-01

The purpose of this question and answer report is to provide a clear, easy-to-understand explanation of revised radiation dose estimates which workers are likely to receive over the course of the cleanup at Three Mile Island, Unit 2, and of the possible health consequences to workers of these new estimates. We will focus primarily on occupational dose, although pertinent questions about public health and safety will also be answered

La première traduction slave de Molière et la naissance du théâtre slovène

Directory of Open Access Journals (Sweden)

Boštjan Marko Turk

2008-12-01

Full Text Available Trois ans après sa première représentation à Versailles, Georges Dandin de Molière a fait l 'objet d'une traduction partielle en slovène réalisée par Franjo Krsto Frankopan. Cette traduction des trois premières scènes peut être objectivement considérée comme l'un des défis les plus ardus de l'histoire littéraire contemporaine. La recherche slovène et internationale l'a tantôt ignoré, tantôt considéré comme lettre morte. La raison en est que, dans ce fragment, Frankopan aurait utilisé le slovène comme langue servant à ridiculiser, comme l'ayaient fait les dramaturges italiens de la Renaissance avec les dialectes slaves. Or, rien n'est plus éloigné de la vérité. Le texte est intégralement écrit en slovène, langue de la mère de Frankopan. Du reste, comme le montre ne serait-ce que l'analyse bergsonienne du comique, Georges Dandin n'est pas un texte comique. Il convient, par contre, de voir le lien entre la traduction du fragment de la pièce de Molière et l'action de Frankopan contre la monarchie habsbourgeoise. Par l'intermédiaire de la diplomatie viennoise, ce dernier cherchait en effet des appuis à la cour du .roi Louis XIV dont l'auteur dramatique comique en titre était précisément Molière. En conclusion, il convient de souligner que le fragment traduit par Frankopan, en tant que premier texte dramatique en langue slovène, invite à remettre en question la datation des débuts du théâtre slovène proposée par les historiens de la littérature.

Conflating Capacity & Authority: Why We're Asking the Wrong Question in the Adolescent Decision-Making Debate.

Science.gov (United States)

Salter, Erica K

2017-01-01

Whether adolescents should be allowed to make their own medical decisions has been a topic of discussion in bioethics for at least two decades now. Are adolescents sufficiently capacitated to make their own medical decisions? Is the mature-minor doctrine, an uncommon legal exception to the rule of parental decision-making authority, something we should expand or eliminate? Bioethicists have dealt with the curious liminality of adolescents-their being neither children nor adults-in a variety of ways. However, recently there has been a trend to rely heavily, and often exclusively, on emerging neuroscientific and psychological data to answer these questions. Using data from magnetic resonance imaging and functional MRI studies on the adolescent brain, authors have argued both that the adolescent brain isn't sufficiently mature to broadly confer capacity on this population and that the adolescent brain is sufficiently mature to assume adolescent capacity. Scholars then accept these data as sufficient for concluding that adolescents should or should not have decision-making authority. Two critical mistakes are being made here. The first is the expectation that neuroscience or psychology is or will be able to answer all our questions about capacity. The second, and more concerning, mistake is the conflation of decision-making capacity with decision-making authority. © 2017 The Hastings Center.

[Study on mercury re-emissions during fly ash utilization].

Science.gov (United States)

Meng, Yang; Wang, Shu-Xiao

2012-09-01

The amount of fly ash produced during coal combustion is around 400 million tons per year in China. About 65%-68% of fly ash is used in building material production, road construction, architecture and agriculture. Some of these utilization processes include high temperature procedures, which may lead to mercury re-emissions. In this study, experiments were designed to simulate the key process in cement production and steam-cured brick production. A temperature programmed desorption (TPD) method was used to study the mercury transformation in the major utilization processes. Mercury re-emission during the fly ash utilization in China was estimated based on the experimental results. It was found that mercury existed as HgCl2 (Hg2 Cl2), HgS and HgO in the fly ash. During the cement production process, more than 98% of the mercury in fly ash was re-emitted. In the steam-curing brick manufacturing process, the average mercury re-emission percentage was about 28%, which was dominated by the percentage of HgCl2 (Hg2 Cl2). It is estimated that the mercury re-emission during the fly ash utilization have increased from 4.07 t in 2002 to 9.18 t in 2008, of which cement industry contributes about 96.6%.

Low-temperature heat capacity and thermodynamic properties of [Re{sub 2}(Ile){sub 4}(H{sub 2}O){sub 8}](ClO{sub 4}){sub 6} (Re=Nd, Er, Ile=isoleucine)

Energy Technology Data Exchange (ETDEWEB)

Lan Xiaozheng; Tan Zhicheng; Liu Beiping; Nan Zhaodong; Sun Lixian; Xu Fen

2003-06-03

The heat capacities of two kinds of rare-earth element solid complexes with isoleucine [Re{sub 2}(Ile){sub 4}(H{sub 2}O){sub 8}](ClO{sub 4}){sub 6} (where Re=Nd, Er, and Ile=isoleucine) have been measured by an automatic adiabatic calorimeter in the temperature range from 80 to 370 K. Two solid-solid phase transitions were found from the C{sub p} curve of Nd formed complex in the range of 165-175 K with a peak temperature of 167.88 K and in the range of 195-210 K with a peak temperature of 202.13 K. The corresponding molar enthalpies of these phase transitions were determined to be 404.61 J mol{sup -1} and 2.955 kJ mol{sup -1}, respectively. One solid-solid phase transition was found for the Er formed complex in the range of 190-205 K with a peak temperature of 193.42 K. The corresponding molar enthalpy of this transition was 14.11 kJ mol{sup -1}. Smooth heat capacities and thermodynamic functions relative to the standard state (298.15 K), H{sub T}-H{sub 298.15}, S{sub T}-S{sub 298.15} and -[G{sub T}-G{sub 298.15}], of the two compounds, were calculated on basis of experimental heat capacity data. Possible mechanisms of thermal decompositions for the pair of compounds were suggested according to the thermogravimetric (TG) analysis.

Recurrent pannus formation causing prosthetic aortic valve dysfunction: is excision without valve re-replacement applicable?

Science.gov (United States)

Darwazah, Ahmad K

2012-06-29

Prosthetic valve dysfunction at aortic position is commonly caused by pannus formation. The exact etiology is not known. It arises from ventricular aspect of the prosthesis encroaching its leaflets causing stenosis or it may remain localized causing left ventricular outflow tract obstruction without affecting valve function.The difference in location entails different approaches in management. Such a pathology requires surgical excision of the pannus with or without valve re-replacement.A recurrent pannus was observed in a female patient who needed repeated surgical intervention to excise a localized pannus without re-replacement of a well functioning prosthetic valve.Management of our case presents several questions, whether recurrence of pannus is caused by sparing the prosthetic valve, is it simply an exaggeration of an inflammatory healing process in certain individuals or is it ideal to re-replace the valve despite a well preserved function.

Inflammatory responses, matrix remodeling, and re-epithelialization after fractional CO2 laser treatment of scars.

Science.gov (United States)

DeBruler, Danielle M; Blackstone, Britani N; Baumann, Molly E; McFarland, Kevin L; Wulff, Brian C; Wilgus, Traci A; Bailey, J Kevin; Supp, Dorothy M; Powell, Heather M

2017-09-01

Fractional CO 2 laser therapy has been used to improve scar pliability and appearance; however, a variety of treatment protocols have been utilized with varied outcomes. Understanding the relationship between laser power and extent of initial tissue ablation and time frame for remodeling could help determine an optimum power and frequency for laser treatment. The characteristics of initial injury caused by fractional CO 2 laser treatment, the rates of dermal remodeling and re-epithelialization, and the extent of inflammation as a function of laser stacking were assessed in this study in a porcine scar model. Full-thickness burn wounds were created on female Red Duroc pigs followed by immediate excision of the eschar and split-thickness autografting. Three months after injury, the resultant scars were treated with a fractional CO 2 laser with 70 mJ of energy delivered as either a single pulse or stacked for three consecutive pulses. Immediately prior to laser treatment and at 1, 24, 96, and 168 hours post-laser treatment, transepidermal water loss (TEWL), erythema, and microscopic characteristics of laser injury were measured. In addition, markers for inflammatory cytokines, extracellular matrix proteins, and re-epithelialization were quantified at all time points using qRT-PCR. Both treatments produced erythema in the scar that peaked 24 hours after treatment then decreased to basal levels by 168 hours. TEWL increased after laser treatment and returned to normal levels between 24 and 96 hours later. Stacking of the pulses did not significantly increase the depth of ablated wells or extend the presence of erythema. Interleukin 6 and monocyte chemoattractant protein-1 were found to increase significantly 1 hour after treatment but returned to baseline by 24 hours post laser. In contrast, expression of transforming growth factor β1 and transforming growth factor β3 increased slowly after treatment with a more modest increase than interleukin 6 and monocyte

Methanesulfonates of high-valent metals. Syntheses and structural features of MoO_2(CH_3SO_3)_2, UO_2(CH_3SO_3)_2, ReO_3(CH_3SO_3), VO(CH_3SO_3)_2, and V_2O_3(CH_3SO_3)_4 and their thermal decomposition under N_2 and O_2 atmosphere

International Nuclear Information System (INIS)

Betke, Ulf; Neuschulz, Kai; Wickleder, Mathias S.

2011-01-01

Oxide methanesulfonates of Mo, U, Re, and V have been prepared by reaction of MoO_3, UO_2(CH_3COO)_2.2 H_2O, Re_2O_7(H_2O)_2, and V_2O_5 with CH_3SO_3H or mixtures thereof with its anhydride. These compounds are the first examples of solvent-free oxide methanesulfonates of these elements. MoO_2(CH_3SO_3)_2 (Pbca, a=1487.05(4), b=752.55(2), c=1549.61(5) pm, V=1.73414(9) nm"3, Z=8) contains [MoO_2] moieties connected by [CH_3SO_3] ions to form layers parallel to (100). UO_2(CH_3SO_3)_2 (P2_1/c, a=1320.4(1), b=1014.41(6), c=1533.7(1) pm, β=112.80(1) "c"i"r"c"l"e, V=1.8937(3) nm"3, Z=8) consists of linear UO_2"2"+ ions coordinated by five [CH_3SO_3] ions, forming a layer structure. VO(CH_3SO_3)_2 (P2_1/c, a=1136.5(1), b=869.87(7), c=915.5(1) pm, β=113.66(1) "c"i"r"c"l"e, V=0.8290(2) nm"3, Z=4) contains [VO] units connected by methanesulfonate anions to form corrugated layers parallel to (100). In ReO_3(CH_3SO_3) (P anti 1, a=574.0(1), b=1279.6(3), c=1641.9(3) pm, α=102.08(2), β=96.11(2), γ=99.04(2) "c"i"r"c"l"e, V=1.1523(4) nm"3, Z=8) a chain structure exhibiting infinite O-[ReO_2]-O-[ReO_2]-O chains is formed. Each [ReO_2]-O-[ReO_2] unit is coordinated by two bidentate [CH_3SO_3] ions. V_2O_3(CH_3SO_3)_4 (I2/a, a=1645.2(3), b=583.1(1), c=1670.2(3) pm, β=102.58(3), V=1.5637(5) pm"3, Z=4) adopts a chain structure, too, but contains discrete [VO]-O-[VO] moieties, each coordinated by two bidentate [CH_3SO_3] ligands. Additional methanesulfonate ions connect the [V_2O_3] groups along [001]. Thermal decomposition of the compounds was monitored under N_2 and O_2 atmosphere by thermogravimetric/differential thermal analysis and XRD measurements. Under N_2 the decomposition proceeds with reduction of the metal leading to the oxides MoO_2, U_3O_7, V_4O_7, and VO_2; for MoO_2(CH_3SO_3)_2, a small amount of MoS_2 is formed. If the thermal decomposition is carried out in a atmosphere of O_2 the oxides MoO_3 and V_2O_5 are formed. (Copyright copyright 2011 WILEY-VCH Verlag

Several new phases in RE-Mg-Ge systems (RE = rare earth metal) - syntheses, structures, and chemical bonding

International Nuclear Information System (INIS)

Suen, Nian-Tzu; Bobev, Svilen

2012-01-01

Reported are the synthesis and structural characterization of Ce_5Mg_8Ge_8 (its own structure type), CeMg_2_-_xGe_2_+_x (BaAl_4-type structure), RE_4Mg_7Ge_6 (RE = Ce-Nd, Sm; La_4Mg_7Ge_6-type structure), and RE_4Mg_5Ge_6 (RE = Ce, Pr; Tm_4Zn_5Ge_6-type structure). The structures of these compounds have been established by single-crystal and powder X-ray diffraction. These compounds are closely related to each other not only in their chemical compositions but also in their structures. A common structural feature of all are MgGe_4 tetrahedra, which are connected by corner- and/or edge-sharing into complex polyanionic frameworks with the rare-earth metal atoms filling the ''empty'' space. The structures are compared to known types of structures, and we have investigated the chemical bonding in Ce_5Mg_8Ge_8 with electronic structure calculations, which were carried out by the tight-bonding linear muffin-tin orbital (TB-LMTO) method. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Do Père David's deer lose memories of their ancestral predators?

Directory of Open Access Journals (Sweden)

Chunwang Li

Full Text Available Whether prey retains antipredator behavior after a long period of predator relaxation is an important question in predator-prey evolution. Père David's deer have been raised in enclosures for more than 1200 years and this isolation provides an opportunity to study whether Père David's deer still respond to the cues of their ancestral predators or to novel predators. We played back the sounds of crows (familiar sound and domestic dogs (familiar non-predators, of tigers and wolves (ancestral predators, and of lions (potential naïve predator to Père David's deer in paddocks, and blank sounds to the control group, and videoed the behavior of the deer during the experiment. We also showed life-size photo models of dog, leopard, bear, tiger, wolf, and lion to the deer and video taped their responses after seeing these models. Père David's deer stared at and approached the hidden loudspeaker when they heard the roars of tiger or lion. The deer listened to tiger roars longer, approached to tiger roars more and spent more time staring at the tiger model. The stags were also found to forage less in the trials of tiger roars than that of other sound playbacks. Additionally, it took longer for the deer to restore their normal behavior after they heard tiger roars, which was longer than that after the trial of other sound playbacks. Moreover, the deer were only found to walk away after hearing the sounds of tiger and wolf. Therefore, the tiger was probably the main predator for Père David's deer in ancient time. Our study implies that Père David's deer still retain the memories of the acoustic and visual cues of their ancestral predators in spite of the long term isolation from natural habitat.

The Chemistry of Re-188 Radiopharmaceuticals: Could Re-188 Play the Same Role in Therapy as Tc-99m in Diagnostics?

International Nuclear Information System (INIS)

Duatti, A.

2009-01-01

Radiopharmaceuticals incorporating the β-emitting radionuclide Re-188 are still attracting much interest for their potential application in nuclear medicine as therapeutic agents. There are many advantages of employing this class of radioactive compounds as briefly summarized in the following. (1) Re-188 emits a high-energy β- particle (2.1 MeV) that can be efficiently used to deliver high-dose radiation to the target. (2) Re-188 concomitantly emits a 155-keV γ photon that can be conveniently employed to obtain good-quality SPECT images of the biodistribution of Re-188 radiopharmaceuticals and, ultimately, following in vivo the course of the therapy. (3) Re-188 has a relatively short half-life (17 hours) that may allow multiple treatments of the same patient's disease. (4) Re-188 is a radiometal belonging to the same group of Tc-99m in the transition metal series of the Periodic Table, and shares with its cogener similar (though not identical) chemical properties that could be useful for designing a broad class of Re-188 radiopharmaceuticals having the same biodistribution properties of the corresponding Tc-99m analogues. (5) Similarly to Tc-99m, the radionuclide Re-188 is produced in high-specific activity through the 188 W/ 188 Re transportable generator system. A first challenge encountered in the attempt to develop efficient labeling procedures for Re-188 was related to the low radiochemical yield usually observed in tracer-level preparations of Re-188 radiopharmaceuticals starting from generator-produced [ 188 ReO 4 ]-. This drawback is commonly associated with the low value of the standard reduction potential of the tetraoxo anion as compared to the corresponding Tc-99m pertechnetate anion. In recent years, we reported a simple and efficient procedure for overcoming this problem based on a general chemical principle called 'expansion of the coordination sphere' and involving the addition to the reaction vial of an ancillary ligand (usually, chelating hard

In vitro structure-activity relationship of Re-cyclized octreotide analogues

Energy Technology Data Exchange (ETDEWEB)

Dannoon, Shorouk F. [Department of Chemistry, University of Missouri, Columbia, MO 65211 (United States); Bigott-Hennkens, Heather M. [Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO 65211 (United States); Ma Lixin [Department of Radiology, University of Missouri, Columbia, MO 65211 (United States); International Institute of Nano and Molecular Medicine, University of Missouri, Columbia, MO 65211 (United States); Nuclear Science and Engineering Institute, University of Missouri, Columbia, MO 65211 (United States); Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201 (United States); Gallazzi, Fabio [Structural Biology Core, University of Missouri, Columbia, MO 65211 (United States); Lewis, Michael R., E-mail: lewismic@missouri.ed [Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO 65211 (United States); Department of Radiology, University of Missouri, Columbia, MO 65211 (United States); Nuclear Science and Engineering Institute, University of Missouri, Columbia, MO 65211 (United States); Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201 (United States); Jurisson, Silvia S., E-mail: jurissons@missouri.ed [Department of Chemistry, University of Missouri, Columbia, MO 65211 (United States); Department of Radiology, University of Missouri, Columbia, MO 65211 (United States); Nuclear Science and Engineering Institute, University of Missouri, Columbia, MO 65211 (United States)

2010-07-15

Introduction: Development of radiolabeled octreotide analogues is of interest for targeting somatostatin receptor (SSTR)-positive tumors for diagnostic and therapeutic purposes. We are investigating a direct labeling approach for incorporation of a Re ion into octreotide analogues, where the peptide sequences are cyclized via coordination to Re rather than through a disulfide bridge. Methods: Various octreotide analogue sequences and coordination systems (e.g., S{sub 2}N{sub 2} and S{sub 3}N) were synthesized and cyclized with nonradioactive Re. In vitro competitive binding assays with {sup 111}In-DOTA-Tyr{sup 3}-octreotide in AR42J rat pancreatic tumor cells yielded IC{sub 50} values as a measure of SSTR affinity of the Re-cyclized analogues. Three-dimensional structures of Re-cyclized Tyr{sup 3}-octreotate and its disulfide-bridged analogue were calculated from two-dimensional NMR experiments to visualize the effect of metal cyclization on the analogue's pharmacophore. Results: Only two of the 11 Re-cyclized analogues investigated showed moderate in vitro binding affinity toward somatostatin subtype 2 receptors. Three-dimensional molecular structures of Re- and disulfide-cyclized Tyr{sup 3}-octreotate were calculated, and both of their pharmacophore turns appear to be very similar with minor differences due to metal coordination to the amide nitrogen of one of the pharmacophore amino acids. Conclusions: Various Re-cyclized analogues were developed and analogue 4 had moderate affinity toward somatostatin subtype 2 receptors. In vitro stable studies that are in progress showed stable radiometal cyclization of octreotide analogues via NS{sub 3} and N{sub 2}S{sub 2} coordination forming five- and six-membered chelate rings. In vivo biodistribution studies are underway of {sup 99m}Tc-cyclized analogue 4.

Integrated Canada-U.S. Power Sector Modeling with the Regional Energy Deployment System (ReEDS)

Energy Technology Data Exchange (ETDEWEB)

Martinez, A.; Eurek, K.; Mai, T.; Perry, A.

2013-02-01

The electric power system in North America is linked between the United States and Canada. Canada has historically been a net exporter of electricity to the United States. The extent to which this remains true will depend on the future evolution of power markets, technology deployment, and policies. To evaluate these and related questions, we modify the Regional Energy Deployment System (ReEDS) model to include an explicit representation of the grid-connected power system in Canada to the continental United States. ReEDS is unique among long-term capacity expansion models for its high spatial resolution and statistical treatment of the impact of variable renewable generation on capacity planning and dispatch. These unique traits are extended to new Canadian regions. We present example scenario results using the fully integrated Canada-U.S. version of ReEDS to demonstrate model capabilities. The newly developed, integrated Canada-U.S. ReEDS model can be used to analyze the dynamics of electricity transfers and other grid services between the two countries under different scenarios.

Can multiple-choice questions simulate free-response questions?

OpenAIRE

Lin, Shih-Yin; Singh, Chandralekha

2016-01-01

We discuss a study to evaluate the extent to which free-response questions could be approximated by multiple-choice equivalents. Two carefully designed research-based multiple-choice questions were transformed into a free-response format and administered on the final exam in a calculus-based introductory physics course. The original multiple-choice questions were administered in another similar introductory physics course on final exam. Findings suggest that carefully designed multiple-choice...

Business process re-engineering in service operations

International Nuclear Information System (INIS)

McClintock, J.W.

1995-01-01

The concept of business process re-engineering, and how it was applied to the operations of the Consumers Gas Company were discussed. Business process re-engineering was defined as the improvement of the efficiency of the customer-service process, and the overall improvement of practices and operations. The re-engineering project was said to involve a thorough analysis of information technology, current limitations, and business operational needs, undertaken on an enterprise-wide basis. Viewed generically,a re-engineering project was said to have six major components: (1) business drivers (i.e. the articulation of the Company's strategic issues); (2) benchmark measures; (3) future state process models; (4) cost/benefit analysis; (5) a change management plan; and (6) a development plan. Business improvements expected to result from the project include reduced cost of operation, reduction of waste, and a substantially complete re-design of the business process. Management of the project involved a team approach, and help of a consultant to identify the scope of the re-design, its limitations, and future state. A life expectancy of approximately 10 years was given for the re-engineering plan, with annual benefits (in terms of cost reduction) of $4.6 million by the year 2000

Development and application of the RE-AIM QuEST mixed methods framework for program evaluation.

Science.gov (United States)

Forman, Jane; Heisler, Michele; Damschroder, Laura J; Kaselitz, Elizabeth; Kerr, Eve A

2017-06-01

To increase the likelihood of successful implementation of interventions and promote dissemination across real-world settings, it is essential to evaluate outcomes related to dimensions other than Effectiveness alone. Glasgow and colleagues' RE-AIM framework specifies four additional types of outcomes that are important to decision-makers: Reach, Adoption, Implementation (including cost), and Maintenance. To further strengthen RE-AIM, we propose integrating qualitative assessments in an expanded framework: RE-AIM Qualitative Evaluation for Systematic Translation (RE-AIM QuEST), a mixed methods framework. RE-AIM QuEST guides formative evaluation to identify real-time implementation barriers and explain how implementation context may influence translation to additional settings. RE-AIM QuEST was used to evaluate a pharmacist-led hypertension management intervention at 3 VA facilities in 2008-2009. We systematically reviewed each of the five RE-AIM dimensions and created open-ended companion questions to quantitative measures and identified qualitative and quantitative data sources, measures, and analyses. To illustrate use of the RE-AIM QuEST framework, we provide examples of real-time, coordinated use of quantitative process measures and qualitative methods to identify site-specific issues, and retrospective use of these data sources and analyses to understand variation across sites and explain outcomes. For example, in the Reach dimension, we conducted real-time measurement of enrollment across sites and used qualitative data to better understand and address barriers at a low-enrollment site. The RE-AIM QuEST framework may be a useful tool for improving interventions in real-time, for understanding retrospectively why an intervention did or did not work, and for enhancing its sustainability and translation to other settings.

Software Toolchain for Large-Scale RE-NFA Construction on FPGA

Directory of Open Access Journals (Sweden)

Yi-Hua E. Yang

2009-01-01

and O(n×m memory by our software. A large number of RE-NFAs are placed onto a two-dimensional staged pipeline, allowing scalability to thousands of RE-NFAs with linear area increase and little clock rate penalty due to scaling. On a PC with a 2 GHz Athlon64 processor and 2 GB memory, our prototype software constructs hundreds of RE-NFAs used by Snort in less than 10 seconds. We also designed a benchmark generator which can produce RE-NFAs with configurable pattern complexity parameters, including state count, state fan-in, loop-back and feed-forward distances. Several regular expressions with various complexities are used to test the performance of our RE-NFA construction software.

Non-Destructive Testing: Sample Questions for Conduct of Examinations at Levels 1 and 2

International Nuclear Information System (INIS)

2010-01-01

The International Atomic Energy Agency (IAEA) supports industrial applications of radiation technology which include non-destructive testing (NDT) under its various programmes such as individual country Technical Co-operation (TC) projects, Regional Projects and Coordinated Research Projects (CRPs). NDT technology is essentially needed for the improvement of the quality of industrial products, equipment and plants all over the world, especially in developing Member States. Trained and certified personnel is one of the essential requirements for applying this technology in industry. With this in view, the IAEA first played an important role in cooperation with the International Organisation for Standardisation (ISO) for the development of a standard for training and certification of NDT personnel, namely ISO 9712, 'Non-Destructive Testing: Qualification and Certification of Personnel'. Subsequently the syllabi and needed training materials were identified and developed for the creation of, in each of the Member States, a core group of personnel who are trained and qualified to establish the training and certification process in their respective countries. One of the important requirements for such a process is to have the examination questions for conducting the certification examinations. A need had been felt to compile the appropriate questions firstly for conducting these examinations at the national and regional levels and secondly to provide these to the certification bodies of the Member States so that they could initiate their own level 1 and 2 certification examinations. For this purpose, Experts' Task Force Meetings were convened first in Accra, Ghana and then in Vienna, Austria under the AFRA regional projects on NDT. The experts examined and discussed in detail the ISO 9712 (1999 and 2005 versions) requirements for general, specific and practical examinations for level 1 and 2 personnel. After that a set of questions has been established which are

Nuclear medicine board review. Questions and answers for self-assessment. 2. ed.

International Nuclear Information System (INIS)

Goldfarb, C.R.; Ongseng, F.; Zuckier, L.S.; Karam, M.; Cooper, J.A.

2007-01-01

This book provides thorough preparation for certification examinations by the American Board of Radiology (Nuclear Medicine section and Special Competency), the American Board of Nuclear Medicine, and the America Board of Nuclear Cardiology. More than 1,780 questions test the reader's knowledge of the diagnostic and therapeutic uses of radionuclides, single-photon applications, and positron emission tomography (PET). Features: - A convenient question and answer format, in which questions appear on the left and answers on the right, allowing the reader to rapidly quiz and review. - New chapters addressing the emergence of PET/CT. - Measurements provided in both American standard and SI metric units. Ideal for board exam preparation, this concise text is an up-to-date question and answer review for the most important topics in nuclear medicine. (orig.)

Nuclear energy. Towards a re-launching in the UK?

International Nuclear Information System (INIS)

Marante, W.

2006-01-01

While the country recently started a debate about energy, United Kingdom is questioning about a re-launching of its nuclear energy. Even if UK's history of atomic energy is rather old (first nuclear power plant, Calder Hall, built in 1953), the lack of standardization of british plants, the fear of terrorism, the uncertainties about radioactive wastes, and a series of incidents at the Sellafield reprocessing plant have calmed down the infatuations of the past. This paper makes a brief overview of the energy prospects of a country where nuclear energy is in standby since 10 years. (J.S.)

SPARQL Query Re-writing Using Partonomy Based Transformation Rules

Science.gov (United States)

Jain, Prateek; Yeh, Peter Z.; Verma, Kunal; Henson, Cory A.; Sheth, Amit P.

Often the information present in a spatial knowledge base is represented at a different level of granularity and abstraction than the query constraints. For querying ontology's containing spatial information, the precise relationships between spatial entities has to be specified in the basic graph pattern of SPARQL query which can result in long and complex queries. We present a novel approach to help users intuitively write SPARQL queries to query spatial data, rather than relying on knowledge of the ontology structure. Our framework re-writes queries, using transformation rules to exploit part-whole relations between geographical entities to address the mismatches between query constraints and knowledge base. Our experiments were performed on completely third party datasets and queries. Evaluations were performed on Geonames dataset using questions from National Geographic Bee serialized into SPARQL and British Administrative Geography Ontology using questions from a popular trivia website. These experiments demonstrate high precision in retrieval of results and ease in writing queries.

Re-thinking residential mobility

Science.gov (United States)

van Ham, Maarten; Findlay, Allan M.

2015-01-01

While researchers are increasingly re-conceptualizing international migration, far less attention has been devoted to re-thinking short-distance residential mobility and immobility. In this paper we harness the life course approach to propose a new conceptual framework for residential mobility research. We contend that residential mobility and immobility should be re-conceptualized as relational practices that link lives through time and space while connecting people to structural conditions. Re-thinking and re-assessing residential mobility by exploiting new developments in longitudinal analysis will allow geographers to understand, critique and address pressing societal challenges. PMID:27330243

Four Questions

Science.gov (United States)

Hark-Weber, Amara G., Ed.

2013-01-01

The author is pleased to introduce a new section in "TAJ," Four Questions. The structure is simple: four questions are asked to teaching artists working in various media and locations. The questions are always the same, but because each teaching artist's approach is unique, their answers will provide an insight into particular methodologies that…

Synthesis of {sup 188}Re-DMSA complex using carrier-free {sup 188}Re

Energy Technology Data Exchange (ETDEWEB)

Hashimoto, Kazuyuki; Izumo, Mishiroku [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Islam, M S

1997-03-01

The synthesis of rhenium-DMSA labelled compound using carrier-free {sup 188}Re from the {sup 188}W/{sup 188}Re generator has been carried out. Stannous chloride was used as the reducing agent for reduction of rhenium and ascorbic acid was used as an antioxidant in the reaction media. The dependence of the yield of Re-DMSA complex upon the concentration of reducing agent, pH, reaction time, anti-oxidant, carrier and temperature was investigated. Under optimum conditions, the yield of Re-DMSA complexes were more than 98% for the carrier-free as well as carrier-added {sup 188}Re. The stability of the Re-DMSA complexes at different pH and time were also investigated. It was found that the Re-DMSA complex was very stable and did not undergo any changes or decomposition with the changes of pH from its initial values even after 48 hours of pH change for carrier-free as well as carrier-added complexes. (author)

Developing the 186 Re radiolabelling procedures of peptides and monoclonal antibodies

International Nuclear Information System (INIS)

Lungu, V.; Mihailescu, G.

1999-01-01

Mono and poli-clonal antibodies are the most recent candidate molecules for the radiopharmaceutical preparation used in radioimmunotherapy and radiodiagnostic. Our study presents results in 186 Re direct labelling of HIgG (Human Immunoglobulin G) poli-clonal antibody. The steps in labelling process are: 1. pre-reduction -S-S- bridges of HIgG molecule with ascorbic acid in pH = 3.5 - 4.5; 2. preparation of the reducing system for 186 ReO 4 - in presence of Sn 2+ ions excess and 3. coupling 186 Re (red) to -SH groups of biomolecules. The specific reactions of each step above are controlled by: incubation time and temperature, pH, molar ratio 186 Re: HIgG. 186 Re-HIgG samples were purified by gel elution chromatography method and the quality control was performed by chromatography techniques. To labelled of HIgG we effected the pre-reduction of -S-S- bridges of biomolecules to sulfhydryls using the following reducing agents: ascorbic acid, cysteine, active hydrogen, 2,3 dimercaptopropanol. The pre-reduction reactions are controlled by mass ratios of reduction agent/biomolecule, pH, temperature and time of incubation. HIgG was the biomolecule used in the pre-reduction reactions. The specific parameters for each systems are presented. The stannous chloride was used as reducing agent in two systems, SnCl 2 : 0.05 N HCl and SnCl 2 : 20 mg/ml citric acid. The coupling reaction of 186 Re (red) with the biomolecule has been controlled by time and incubation temperature and the influence of pH regarding the binding of 186 Re to the biomolecule. 186 Re-HIgG was obtained by: i) incubation at the room temperature, 1 hour time of HIgG in thiol form and 186 Re in reducing form and ii) incubation of HIgG in thiol form, at 37 deg C and 22 hours time, with adding after pre-reduction of SnCl 2 and Na 186 ReO 4 . Quality control was effected by chromatography techniques (paper and gel chromatography) on labelled biomolecule before and after purification. The elution gel chromatography

Riigivara õiguslikust režiimist. [1.-2. osa] / Peeter Kask

Index Scriptorium Estoniae

Kask, Peeter

1996-01-01

Riigivara õiguslik režiim 1990-1996. Riigivara baasil tegutsevate organisatsioonide jaotamine rühmadesse. Riigivaraseaduse üldmõistetest, riigivara kasutada andmisest, võõrandamisest, kõlbmatuks tunnistamisest, riigivara registrist ning eraõigusliku juriidilise isiku halduses olevast riigivarast. Õiend Juridica, 1997, Nr. 1, Lk. 40

Recurrent pannus formation causing prosthetic aortic valve dysfunction: Is excision without valve re-replacement applicable?

Directory of Open Access Journals (Sweden)

Darwazah Ahmad K

2012-06-01

Full Text Available Abstract Prosthetic valve dysfunction at aortic position is commonly caused by pannus formation. The exact etiology is not known. It arises from ventricular aspect of the prosthesis encroaching its leaflets causing stenosis or it may remain localized causing left ventricular outflow tract obstruction without affecting valve function. The difference in location entails different approaches in management. Such a pathology requires surgical excision of the pannus with or without valve re-replacement. A recurrent pannus was observed in a female patient who needed repeated surgical intervention to excise a localized pannus without re-replacement of a well functioning prosthetic valve. Management of our case presents several questions, whether recurrence of pannus is caused by sparing the prosthetic valve, is it simply an exaggeration of an inflammatory healing process in certain individuals or is it ideal to re-replace the valve despite a well preserved function.

New quaternary indides RE{sub 7}Ni{sub 5-x}Ge{sub 3+x}In{sub 6} (RE = La, Nd, Sm)

Energy Technology Data Exchange (ETDEWEB)

Dominyuk, Nataliya [Lviv Univ. (Ukraine). Dept. of Inorganic Chemistry; Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Zaremba, Vasyl I. [Lviv Univ. (Ukraine). Dept. of Inorganic Chemistry; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie

2011-04-15

The quaternary indides RE{sub 7}Ni{sub 5-x}Ge{sub 3+x}In{sub 6} (RE = La,Nd, Sm) were synthesized from the elements by arc-melting. Single crystals were grown by slow cooling of the polycrystalline samples. The structures were characterized by powder and single-crystal X-ray diffraction: Ce{sub 7}Ni{sub 4.73}Ge{sub 3.27}In{sub 6} type, P6/m, Z = 1, a = 1147.05(9), c = 426.82(4) pm, wR2 = 0.0652, 528 F{sup 2} values for La{sub 7}Ni{sub 4.46}Ge{sub 3.54}In{sub 6}, a = 1134.5(7), c = 407.1(7) pm, wR2 = 0.0419, 441 F{sup 2} values for Nd{sub 7}Ni{sub 4.91}Ge{sub 3.09}In{sub 6}, and a = 1133.5(2), c = 404.3(1) pm, wR2 = 0.0619, 498 F{sup 2} values for Sm{sub 7}Ni{sub 4.31}Ge{sub 3.69}In{sub 6}, with 25 parameters per refinement. Characteristic features of the RE{sub 7}Ni{sub 5-x}Ge{sub 3+x}In{sub 6} structures are hexagonal, AlB{sub 2}-related prisms around the RE1 atoms and a tricapped, trigonalprismatic coordination of the nickel atoms. (orig.)

Re-excision of margins before breast radiation-diagnostic or therapeutic?

International Nuclear Information System (INIS)

Chism, Derek B.; Freedman, Gary M.; Li, Tianyu; Anderson, Penny R.

2006-01-01

Purpose: To identify factors in breast cancer patients that predict the pathologic results of re-excision for close or positive margins and to determine the effect on local control. Methods and Materials: We divided 1,044 patients with Stage I-II breast cancer with a close (≤2 mm) or positive margin after initial excision into three groups. Group 1 included 199 patients without additional excision, Group 2 included 546 patients with re-excision found to be free of cancer, and Group 3 included 299 patients with re-excision and residual cancer. All patients were treated with radiotherapy with a median follow-up of 6.7 years. Results: The 10-year local control rate was 95% for Group 1 and 94% for Groups 2 and 3 (p = 0.788). Of the 846 patients, 65% had no residual disease on re-excision and 35% did have residual tumor. The factors significantly associated with positive re-excision findings were initial positive margins, positive nodes, Stage T2 tumor, and an extensive intraductal component. The 10-year local control rate was 95% for Group 2 vs. 91% for Group 3 (p = 0.038). Conclusion: The low recurrence rates seen in this study suggest that selected patients with non-negative margins, particularly those with a low risk of having residual disease at re-excision, may be treated with radiotherapy

Extraction of Tc(VII) and Re(VII) on TRU resin

Energy Technology Data Exchange (ETDEWEB)

Guerin, Nicolas; Riopel, Remi; Kramer-Tremblay, Sheila [Canadian Nuclear Laboratories (CNL), Chalk River, ON (Canada). Radiobiology and Health Branch; De Silva, Nimal; Cornett, Jack [Ottawa Univ., ON (Canada). Dept. of Earth and Environmental Sciences; Dai, Xiongxin [China Institute for Radiation Protection, Beijing (China)

2017-06-01

TRU resin can be used to rapidly and selectively extract Tc(VII) and Re(VII). The retention capacity curves of Tc(VII) and Re(VII) for HNO{sub 3}, HCl, H{sub 2}SO{sub 4} and H{sub 3}PO{sub 4} solutions were studied and prepared. Tc(VII) and Re(VII) were simultaneously extracted in 2 M H{sub 2}SO{sub 4} and 1.5 M H{sub 3}PO{sub 4} and were effectively separated from Mo(VI) and Ru(III). Tc(VII) and Re(VII) remained strongly bonded to the resin even after washing using a large volume of 2 M H{sub 2}SO{sub 4} at a relatively high flow rate. Also, they were both completely eluted from the resin using 15 mL of near boiling water, an eluent directly compatible for ICP-MS instrument measurements.

Synthesis of ReN3 Thin Films by Magnetron Sputtering

Directory of Open Access Journals (Sweden)

G. Soto

2014-01-01

Full Text Available In this work ReNx films were prepared by reactive magnetron sputtering at room temperature and deposited on a silicon wafer. It was found that the diffractograms of the nitrogen-rich rhenium film are consistent with those produced by high-pressure high-temperature methods, under the assumption that the film is oriented on the substrate. Using density functional calculations it was found that the composition of this compound could be ReN3, instead of ReN2, as stated on previous works. The ReN3 compound fits in the Ama2 (40 orthorhombic space group, and due to the existence of N3 anions between Re layers it should be categorized as an azide. The material is exceptionally brittle and inherently unstable under indentation testing.

How Do You Answer the Life on Mars Question? Use Multiple Small Landers Like Beagle 2

Science.gov (United States)

Gibson, Everett K.; Pillinger, C. T.; Wright, I. P.; Hurst, S. J.; Richter, L.; Sims, M. R.

2012-01-01

To address one of the most important questions in planetary science Is there life on Mars? The scientific community must turn to less costly means of exploring the surface of the Red Planet. The United Kingdom's Beagle 2 Mars lander concept was a small meter-size lander with a scientific payload constituting a large proportion of the flown mass designed to supply answers to the question about life on Mars. A possible reason why Beagle 2 did not send any data was that it was a one-off attempt to land. As Steve Squyres said at the time: "It's difficult to land on Mars - if you want to succeed you have to send two of everything".

Status report on seismic re-evaluation

International Nuclear Information System (INIS)

1998-01-01

re-evaluation of individual plants is typically carried out at intervals of approximately ten years. Major re-evaluations typically take 2 to 3 years to perform at a cost of approximately $US 1 million for software alone, although the majority of re-evaluations are carried out in less time and at lower cost. Methods of seismic re-evaluation include PSA, margins assessments and deterministic analysis, and a common feature of the process is a seismic walk-down, often based on SQUG principles. The input motion levels, seismic categorisation, analysis methods and assessment criteria that are applied depend on the objectives of the re-evaluation. In several responses they are indicated to be generally similar to those specified for new plant. In situ inspection of structures and plant is generally adopted, although most countries use original specifications for material properties, with some in situ evaluation where possible. More realistic criteria than would usually be adopted for new plant are often employed in the assessment of plant behaviour for severe accidents or risk estimates. The majority of countries are satisfied with the seismic re-evaluations that have been carried out to date, although there are a number of recommendations for improvements based on the experience gained so far. The process has resulted in some quite extensive physical modifications, improving the seismic robustness of structures, anchorages and restraints, particularly in older plants. Approximately half of the responding countries reported that they were engaged in active research in the specific field of seismic re-evaluation, but it is noted that there is also considerable effort taking place in the wider field of seismic research, and that this has a direct bearing on the re-evaluation process, leading to an improved understanding of failure modes and more realistic assessments of section capacity. There is also a need to identify future areas of research. It is recommended that some

Synthesis of metallic ReO3 nanowires

International Nuclear Information System (INIS)

Myung, Dongshin; Lee, Yumin; Lee, Jaeyeon; Kim, Myung Hwa; Yu, Hak Ki; Lee, Jong-Lam; Baik, Jeong Min; Kim, Woong

2010-01-01

We present the synthesis of highly crystalline metallic rhenium trioxide (ReO 3 ) nanowires via a simple physical vapor transport at 300 C for the first time. Based on HRTEM, the ReO 3 nanowires exhibit a core of perfect cubic perovskite-type single crystal structure with a shell of thin amorphous and disordered structures of less than 2 nm in the near surface layers. Possibly this is due to proton intercalation induced by the surface reaction of single crystal ReO 3 with water. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Phrasal Paraphrase Based Question Reformulation for Archived Question Retrieval.

Directory of Open Access Journals (Sweden)

Yu Zhang

Full Text Available Lexical gap in cQA search, resulted by the variability of languages, has been recognized as an important and widespread phenomenon. To address the problem, this paper presents a question reformulation scheme to enhance the question retrieval model by fully exploring the intelligence of paraphrase in phrase-level. It compensates for the existing paraphrasing research in a suitable granularity, which either falls into fine-grained lexical-level or coarse-grained sentence-level. Given a question in natural language, our scheme first detects the involved key-phrases by jointly integrating the corpus-dependent knowledge and question-aware cues. Next, it automatically extracts the paraphrases for each identified key-phrase utilizing multiple online translation engines, and then selects the most relevant reformulations from a large group of question rewrites, which is formed by full permutation and combination of the generated paraphrases. Extensive evaluations on a real world data set demonstrate that our model is able to characterize the complex questions and achieves promising performance as compared to the state-of-the-art methods.

Suspension culture process for H9N2 avian influenza virus (strain Re-2).

Science.gov (United States)

Wang, Honglin; Guo, Suying; Li, Zhenguang; Xu, Xiaoqin; Shao, Zexiang; Song, Guicai

2017-10-01

H9N2 avian influenza virus has caused huge economic loss for the Chinese poultry industry since it was first identified. Vaccination is frequently used as a control method for the disease. Meanwhile suspension culture has become an important tool for the development of influenza vaccines. To optimize the suspension culture conditions for the avian influenza H9N2 virus (Re-2 strain) in Madin-Darby Canine Kidney (MDCK) cells, we studied the culture conditions for cell growth and proliferation parameters for H9N2 virus replication. MDCK cells were successfully cultured in suspension, from a small scale to industrial levels of production, with passage time and initial cell density being optimized. The influence of pH on the culture process in the reactor has been discussed and the process parameters for industrial production were explored via amplification of the 650L reactor. Subsequently, we cultivated cells at high cell density and harvested high amounts of virus, reaching 10log2 (1:1024). Furthermore an animal experiment was conducted to detect antibody. Compared to the chicken embryo virus vaccine, virus cultured from MDCK suspension cells can produce a higher amount of antibodies. The suspension culture process is simple and cost efficient, thus providing a solid foundation for the realization of large-scale avian influenza vaccine production.

In situ X-ray and neutron diffraction of the Ruddlesden–Popper compounds (RE2−xSrx)0.98(Fe0.8Co0.2)1−yMgyO4−δ (RE=La, Pr): Structure and CO2 stability

International Nuclear Information System (INIS)

Chatzichristodoulou, C.; Hauback, B.C.; Hendriksen, P.V.

2013-01-01

The crystal structure of the Ruddlesden–Popper compounds (La 1.0 Sr 1.0 ) 0.98 Fe 0.8 Co 0.2 O 4−δ and (La 1.2 Sr 0.8 ) 0.98 (Fe 0.8 Co 0.2 ) 0.8 Mg 0.2 O 4−δ was investigated at 1000 °C in N 2 (a O2 =1×10 −4 ) by in-situ powder neutron diffraction. In-situ powder X-ray diffraction (PXD) was also employed to investigate the temperature dependence of the lattice parameters of the compounds in air and the oxygen activity dependence of the lattice parameters at 800 °C and 1000 °C. The thermal and chemical expansion coefficients, determined along the two crystallographic directions of the tetragonal unit cell, are highly anisotropic. The equivalent pseudo-cubic thermal and chemical expansion coefficients are in agreement with values determined by dilatometry. The chemical stability in CO 2 containing environments of various Ruddlesden–Popper compounds with chemical formula (RE 2−x Sr x ) 0.98 (Fe 0.8 Co 0.2 ) 1−y Mg y O 4−δ (RE=La, Pr), as well as their stability limit in H 2 /H 2 O=4.5 were also determined by in-situ PXD for x=0.9, 1.0 and y=0, 0.2. - Graphical abstract: Influence of electronic configuration on bond length, lattice parameters and anisotropic thermal and chemical expansion. Highlights: ► The thermal and chemical expansion coefficients are largely anisotropic. ► The expansion of the perovskite layers is constrained along the a direction. ► The studied compositions show remarkable thermodynamic stability upon reduction. ► The thermal and chemical expansion coefficients are lower than related perovskites. ► The investigated materials decompose in CO 2 containing atmospheres

REAuAl{sub 4}Ge{sub 2} and REAuAl{sub 4}(Au{sub x}Ge{sub 1-x}){sub 2} (RE=rare earth element): Quaternary intermetallics grown in liquid aluminum

Energy Technology Data Exchange (ETDEWEB)

Xiuni, Wu [Department of Chemistry, Michigan State University, East Lansing, Michigan 48824 (United States); Kanatzidis, Mercouri G [Department of Chemistry, Michigan State University, East Lansing, Michigan 48824 (United States)

2005-11-15

The two families of intermetallic phases REAuAl{sub 4}Ge{sub 2} (1) (RE=Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Tm and Yb) and REAuAl{sub 4}(Au{sub x}Ge{sub 1-x}){sub 2} (2) (x=0.4) (RE=Ce and Eu) were obtained by the reactive combination of RE, Au and Ge in liquid aluminum. The structure of (1) adopts the space group R-3m (CeAuAl{sub 4}Ge{sub 2}, a=4.2384(7)A, c=31.613(7)A; NdAuAl{sub 4}Ge{sub 2}, a=4.2258(4)A, c=31.359(5)A; GdAuAl{sub 4}Ge{sub 2}, a=4.2123(6)A, c=30.994(6)A; ErAuAl{sub 4}Ge{sub 2}, a=4.2074(4)A, c=30.717(5)A). The structure of (2) adopts the tetragonal space group P4/mmm with lattice parameters: a=4.3134(8)A, c=8.371(3)A for EuAuAl{sub 4}(Au{sub x}Ge{sub 1-x}){sub 2} (x=0.4). Both structure types present slabs of ''AuAl{sub 4}Ge{sub 2}'' or ''AuAl{sub 4}(Au{sub x}Ge{sub 1-x}){sub 2}'' stacking along the c-axis with layers of RE atoms in between. Magnetic susceptibility measurements indicate that the RE atoms (except for Ce and Eu) possess magnetic moments consistent with +3 species. The Ce atoms in CeAuAl{sub 4}Ge{sub 2} and CeAuAl{sub 4}(Au{sub x}Ge{sub 1-x}){sub 2} (x=0.4) appear to be in a mixed +3/+4 valence state; DyAuAl{sub 4}Ge{sub 2} undergoes an antiferromagnetic transition at 11K and below this temperature exhibits metamagnetic behavior. The Eu atoms in EuAuAl{sub 4}(Au{sub x}Ge{sub 1-x}){sub 2} (x=0.4) appear to be in a 2+ oxidation state.

La construction de la matière le modèle Standard

CERN Document Server

Léon, Jacques

2016-01-01

Qu'est-ce que la matière ? Voilà une question à laquelle il pourrait sembler facile de répondre car il n'est rien de plus concret que la matière. Et pourtant, la réponse qu'en donne la physique contemporaine est pour le moins déconcertante ! Le concept-même de particules, briques élémentaires de la matière, s'est volatilisé, dissout dans des objets mathématiques abstraits et abscons pour les non-initiés. Plus nos théories sont précises et plus l'image qu'elles nous renvoient est insaisissable. En un siècle, la représentation des particules s'est métamorphosée en nuages de probabilité portés par des champs quantiques régis par des symétries confinées dans des espaces abstraits. Mais dans un même temps, nous avons réussi le tour de force d'expliquer toute cette complexité avec seulement 16 particules… et une seule théorie, véritable construction de notre conception de la matière : le modèle standard. Ce livre tente de guider le lecteur dans le dédale de la physique des particu...

30 CFR 250.1200 - Question index table.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Question index table. 250.1200 Section 250.1200 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR... Security § 250.1200 Question index table. The table in this section lists questions concerning Oil and Gas...

Areva: questions about a champion

International Nuclear Information System (INIS)

Bottois, P.

2009-01-01

Siemens announced in January 26, 2009 its decision to leave Areva NP, i.e. the Areva/Siemens common daughter company for reactors. This news re-launches the questions about the long-term financing strategy of the Areva group, of its capitalistic partnerships and of its position in the world nuclear market. Siemens on its side wishes to preserve its position in this market and a possible cooperation with the Russian AtomEnergoProm is under discussion. Areva, the world leader of nuclear industry, integrates a mining activity as well and is the world number 3 of uranium exploitation (15% of the world offer). It wishes to double its production by 2012 thanks to big investments in Niger, Namibia and Canada. Areva is developing its enrichment capacities as well thanks to the future Georges-Besse II ultracentrifugation facility which is under construction at Tricastin (Drome, France) and which should be put into service in 2009. And finally, a second EPR (European pressurized reactor), the new generation of Areva reactors, is to be built at Penly (Haute Normandie, France) between 2012 and 2017 and will generate 1400 employments in the region. (J.S.)

An Online National Archive of Multiple-Choice Questions for Astro 101 and the Development of the Question Complexity Rubric

Science.gov (United States)

Cormier, S.; Prather, E.; Brissenden, G.

2011-09-01

We are developing a national archive of multiple-choice questions for use in the Astronomy 101 classroom. These questions are intended to supplement an instructor's implementation of Think-Pair-Share or for their assessment purposes (i.e., exams and homework). We are also developing the Question Complexity Rubric (QCR) to guide members of the Astro 101 teaching and learning community in assisting us with hierarchically ranking questions in this archive based on their conceptual complexity. Using the QCR, a score is assigned to differentiate each question based on the cognitive steps necessary to comprehensively explain the reasoning pathway to the correct answer. The lowest QCR score is given to questions with a reasoning pathway requiring only declarative knowledge. The highest QCR score is given to questions with a reasoning pathway that requires multiple connected cognitive steps. When completed, the online question archive will provide users with the utility to 1) use the QCR to score questions 2) search for and download questions based on topic and/or QCR score, and 3) add their own questions to the archive. Stop by our poster to test your skills at determining question complexity by trying out the QCR with our sample questions.

Defense programs business practices re-engineering QFD exercise

International Nuclear Information System (INIS)

Murray, C.; Halbleib, L.

1996-03-01

The end of the cold war has resulted in many changes for the Nuclear Weapons Complex (NWC). We now work in a smaller complex, with reduced resources, a smaller stockpile, and no new phase 3 weapons development programs. This new environment demands that we re-evaluate the way we design and produce nuclear weapons. The Defense Program (DP) Business Practices Re-engineering activity was initiated to improve the design and production efficiency of the DP Sector. The activity had six goals: (1) to identify DP business practices that are exercised by the Product Realization Process (PRP); (2) to determine the impact (positive, negative, or none) of these practices on defined, prioritized customer criteria; (3) to identify business practices that are candidates for elimination or re-engineering; (4) to select two or three business practices for re-engineering; (5) to re-engineer the selected business practices; and (6) to exercise the re-engineered practices on three pilot development projects. Business practices include technical and well as administrative procedures that are exercised by the PRP. A QFD exercise was performed to address (1)-(4). The customer that identified, defined, and prioritized the criteria to rate the business practices was the Block Change Advisory Group. Five criteria were identified: cycle time, flexibility, cost, product performance/quality, and best practices. Forty-nine business practices were identified and rated per the criteria. From this analysis, the group made preliminary recommendations as to which practices would be addressed in the re-engineering activity. Sixteen practices will be addressed in the re-engineering activity. These practices will then be piloted on three projects: (1) the Electronic Component Assembly (ECA)/Radar Project, (2) the B61 Mod 11, and (3) Warhead Protection Program (WPP)

submitter Performance Test of an 8 kA @ 10-T 4.2-K ReBCO-CORC Cable

CERN Document Server

Mulder, Tim; Mentink, Matthias; van der Laan, Danko; Dhalle, Marc; ten Kate, Herman

2016-01-01

CERN is developing high-current ReBCO conductor on round core (CORC) cables for application in future detector and accelerator magnets. A characterization test on a ReBCO-CORC cable sample and its joints is performed in the 10-T FRESCA cable test facility at CERN. The sample is taken from the first 12-m-long CORC production. Key is the characterization of the field- and temperature-dependent critical currents of the CORC cable at 1.9 K and 4.2 K. Secondary objectives include evaluating the response of the CORC cable to quenches and the performance of cylindrical low resistive cable terminals especially designed and manufactured for use on CORC cables. The 7.6-mm CORC cable features 8 kA at 4.2 K and 10 T, and the joint terminals show a 25 ± 5 - nΩ resistance for 20-cm length.

Irradiation induced precipitation in tungsten based, W-Re alloys

Science.gov (United States)

Williams, R. K.; Wiffen, F. W.; Bentley, J.; Stiegler, J. O.

1983-03-01

Tungsten-base alloys containing 5, 11, and 25 pct Re were irradiated in the EBR-II reactor. Irradiation temperatures ranged from 600 to 1500 °C. All compositions were irradiated to fluences in the range 4.3 to 6.1 X 1025 n/m2 (E > 0.1 MeV), and three 25 pct Re samples were also irradiated to 3.7 X 1026 n/m2 at temperatures 700 to 900 °C. Postirradiation examination included measurement of electrical resistivity at room temperature and lower temperatures, X-ray diffraction, optical metallography, microprobe analysis, and transmission electron microscopy. Irradiation induced resistivity decreases observed in most of the samples suggested second-phase precipitation. Complete results confirmed the precipitate formation in all samples, in disagreement with existing phase diagrams for the W-Re system. Electron diffraction showed the precipitates to be consistent with the cubic, Re-rich X-phase and inconsistent with the σ-phase. Large variations in precipitate morphology and distribution were observed between the different compositions and irradiation conditions. For the 5 and 11 pct Re-alloys, spherically symmetric strain fields surrounded the equiaxed precipitate particles, and were observed even where no particles were visible. These strain fields are believed to arise from local Re enrichment. Thermoelectric data show that the precipitation can lead to decalibration of W/Re thermocouples.

Qualitätsverbesserung von MC Fragen [Quality assurance of Multiple Choice Questions

Directory of Open Access Journals (Sweden)

Rotthoff, Thomas

2006-08-01

Full Text Available [english] Because of the missing relevance of graded examinations at the German medical faculties, there was no need to reflect the question quality in written examinations consistently. Through the new national legislation for medical education certification-relevant, faculty-internal examinations are prescribed. Until now, there is a lack of structures and processes which could lead to an improvement of the question quality. To reflect the different performance of the students, a different severity and a good selectivity of the test questions are necessary. For a interdisciplinary examination for fourth year undergraduate students at the University Hospital Duesseldorf, new Multiple choice (MC- questions which are application-orientated, clearly formulated and to a large extent free from formal errors should be developed. The implementation took place in the conception and performance of Workshops for the construction of MC-questions and the appointment of an interdisciplinary review-committee. It could be shown that an author training facilitates and accelerates the review-process for the committee and that a review process reflects itself in a high practise-orientation of the items. Prospectively, high-quality questions which are created in a review-process and metrological analysed could be read into inter-university databases. Therewith the initial expenditure of time could be reduced. The interdisciplinary constitution of the review-committee offers the possibility of an intensified discussion over content and relevance of the questions. [german] Wegen fehlender notenrelevanter Prüfungen an den Medizinischen Fakultäten in Deutschland bestand bisher keine Notwendigkeit, die Fragenqualität in schriftlichen Prüfungen konsequent zu reflektieren. Erst durch die neue Approbationsordnung sind zeugnisrelevante, fakultätsinterne Prüfungen vorgeschrieben. Es fehlen somit oftmals Strukturen und Prozesse, die zu einer Verbesserung der

Ortho-vanadates K3RE(VO4)2 (RE = La, Pr, Eu, Gd, Dy, Y) for near UV-converted phosphors

International Nuclear Information System (INIS)

Qin, Lin; Wei, Dong-Lei; Huang, Yanlin; Qin, Chuanxiang; Cai, Peiqing; Kim, Sun-Il; Seo, Hyo-Jin

2014-01-01

The orthovanadate poly-crystals K 3 RE(VO 4 ) 2 (RE = La, Pr, Eu, Gd, Dy, Y) were synthesized via the solid-state reaction route. The crystal phase formation was verified through X-ray diffraction (XRD) studies and was performed by structural refinements. The optical properties were also investigated in detail. K 3 RE(VO 4 ) 2 (RE = Eu, Dy, Gd, Pr, La, Y) phosphors present different luminescence behaviors: the profiles of excitation and emission spectra, the spectra shift, the luminescence decay lifetimes, the absolute quantum efficiency (QE), and the CIE color coordinates are very different. The luminescence of K 3 RE(VO 4 ) 2 (RE = La, Gd, Y, Pr) presents yellow or yellowish green color, while, K 3 Dy(VO 4 ) 2 and K 3 Eu(VO 4 ) 2 show white and red luminescence, respectively. This was discussed on the base of the different micro-structure, activator centers, and the charge transfer transitions from [VO 4 ] 3− groups in the lattices. K 3 Y(VO 4 ) 2 and K 3 Eu(VO 4 ) 2 show higher QE values of 47.0% and 45.0% at room temperature, respectively. All the phosphors have efficient absorption in the region of near-UV wavelengths or blue wavelength region. This can well match with the light from UV-LED (360–400 nm) or blue LED chips (450–480 nm) based on GaN semiconductor. K 3 RE(VO 4 ) 2 could be suggested to be a potential candidate to give further investigations for the application on near-UV excited white LEDs. - Graphical abstract: A series of orthovanadates K 3 RE(VO 4 ) 2 (RE = Eu, Dy, Gd, Pr, La, Y) have been developed to be new phosphors with rich luminescence colors; there are efficiency excitation in the near UV wavelength region. Compared with the reported vanadate phosphors K 3 R(VO 4 ) 2 has rich luminescence color, rich color, no concentration quenching, and comparable luminescence QE. - Highlights: • A new phosphor of non-doped of K 3 R(VO 4 ) 2 (R = Eu, Dy, Gd, Pr, La, Y) were developed by solid-state reaction route. • The phosphor

Large magnetization and frustration switching of magnetoresistance in the double-perovskite ferrimagnet Mn2FeReO6.

Science.gov (United States)

Arévalo-López, Angel M; McNally, Graham M; Attfield, J Paul

2015-10-05

Ferrimagnetic A2 BB'O6 double perovskites, such as Sr2 FeMoO6 , are important spin-polarized conductors. Introducing transition metals at the A-sites offers new possibilities to increase magnetization and tune magnetoresistance. Herein we report a ferrimagnetic double perovskite, Mn2 FeReO6 , synthesized at high pressure which has a high Curie temperature of 520 K and magnetizations of up to 5.0 μB which greatly exceed those for other double perovskite ferrimagnets. A novel switching transition is discovered at 75 K where magnetoresistance changes from conventional negative tunneling behavior to large positive values, up to 265 % at 7 T and 20 K. Neutron diffraction shows that the switch is driven by magnetic frustration from antiferromagnetic Mn(2+) spin ordering which cants Fe(3+) and Re(5+) spins and reduces spin-polarization. Ferrimagnetic double perovskites based on A-site Mn(2+) thus offer new opportunities to enhance magnetization and control magnetoresistance in spintronic materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

188W→188Re generator for biomedical applications

International Nuclear Information System (INIS)

Kamioki, Hiroshi; Mirzadeh, S.; Lambrecht, R.M.; Knapp, R. Jr.; Dadachova, K.

1994-01-01

An alumina-based 188 W → 188 Re generator was evaluated for 188 Re yield and elution profile and 188 W breakthrough using various reagents for a three-month period. To address the problem of low specific volume, the generator was eluted with reagents which could be easily destroyed by gentle evaporation from acidic solutions (e.g. NH 4 Cl and NH 4 NO 3 ). We also evaluated a proposed ''alumina/anion-exchange'' tandem generator for the preparation of highly purified 188 Re as perrhenic acid. In parallel studies, the adsorption dynamics of tungsten on alumina showed a sharp rise in the tungsten breakthrough at W/Al 2 O 3 ratio of ∼ 120 mg/g corresponding to a distribution constant of ∼ 8400 from nitrate solution at 0.05 M ionic strength. In adsorption on anion exchange resins, carrier-free 188 Re exhibited a behavior very similar to that of macroscopic quantities of Re. These studies further demonstrated the long and useful shelf-life of 188 W → 188 Re generator. (orig.)

Thermoelectric properties, crystal and electronic structure of semiconducting RECuSe{sub 2} (RE = Pr, Sm, Gd, Dy and Er)

Energy Technology Data Exchange (ETDEWEB)

Esmaeili, Mehdi [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada); Tseng, Yu-Chih [CANMET Materials, Natural Resources Canada, 183 Longwood Road South, Hamilton, Ontario L8P 0A5 (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)

2014-10-15

Highlights: • Crystal and electronic structure of monoclinic and trigonal RECuSe{sub 2} phases. • Thermoelectric properties of the RECuSe{sub 2} phases. • Temperature stability of the RECuSe{sub 2} phases. - Abstract: The ternary RECuSe{sub 2} phases have been prepared and structurally characterized. They adopt either a monoclinic structure (P2{sub 1}/c, z = 4) for lighter rare earths (RE = Pr, Sm and Gd) or Cu-disordered trigonal structure for heavier rare-earths (P3{sup ¯}m1, z = 1, RE = Dy and Er). The resistivity and Seebeck coefficient measurements on GdCuSe{sub 2}, DyCuSe{sub 2} and ErCuSe{sub 2} indicate that the studied phases are p-type semiconductors with relatively small activation energies (0.045–0.11 eV). However, their electrical resistivities are too high (0.45–220 Ω cm at room temperature) to make them competitive thermoelectric materials. Electronic structure calculations indicate presence of a band gap in the RECuSe{sub 2} phases.

Glucagon dynamics during hypoglycaemia and food-re-challenge following treatment with vildagliptin in insulin-treated patients with type 2 diabetes.

Science.gov (United States)

Farngren, J; Persson, M; Schweizer, A; Foley, J E; Ahrén, B

2014-09-01

To determine the effects of dipeptidyl peptidase-4 (DPP-4) inhibition on glucagon dynamics in patients with insulin-treated type 2 diabetes (T2D). The study was a single-centre, double-blind, randomized, placebo controlled crossover study in patients with T2D, mean age 59 ± 6 (s.d.) years and mean haemoglobin A1c 7.7 ± 0.8%, treated with exogenous insulin with or without oral antihyperglycaemic agents. Patients received vildagliptin (50 mg BID) or placebo as add-on to insulin for 4 weeks in random order with a 4-week washout in-between. On day 28 of the respective treatment, patients were served a standard meal (500 kcal) followed by a hyperinsulinaemic hypoglycaemic clamp (target 2.5 mmol/l) and a subsequent food re-challenge (700 kcal). The completers population (n = 29) was analysed. Glucose levels were lower with vildagliptin than with placebo during the meal [areas under the curve (AUC) 1.23 ± 0.07 vs. 1.46 ± 0.05 mol/l min, P vildagliptin (AUC 1.98 ± 0.15 vs. 2.15 ± 0.17 nmol/l min, P = 0.016). In contrast, the glucagon counter-regulation to the insulin-induced hypoglycaemia was sustained by vildagliptin (6.05 ± 1.20 pmol/l during vildagliptin vs.6.94 ± 1.09 pmol/l during placebo, NS). During the food re-challenge after hypoglycaemia, glucagon levels were, again, significantly lower after vildagliptin (AUC 1.30 ± 0.11 vs. 1.52 ± 0.12 nmol/l min, P vildagliptin compared to placebo during meal, hypoglycaemia and food re-challenge. Vildagliptin action to block GLP-1 and GIP inactivation by DPP-4 improves glucagon dynamics during hypoglycaemia, hyperglycaemia and food re-challenge. © 2014 John Wiley & Sons Ltd.

Ménière's Disease: Molecular Analysis of Aquaporins 2, 3 and Potassium Channel KCNE1 Genes in Brazilian Patients.

Science.gov (United States)

Lopes, Karen de Carvalho; Sartorato, Edi Lúcia; da Silva-Costa, Sueli M; de Macedo Adamov, Nadya Soares; Ganança, Fernando Freitas

2016-09-01

Ménière's disease (MD) is a complex disease of unknown etiology characterized by a symptomatic tetrad of vertigo, hearing loss, tinnitus, and aural fullness. In addition to factors related to homeostasis of the inner ear, genetic factors have been implicated in its pathophysiology, including genes related to the transport of water and ionic composition maintenance of the endolymph, such as the aquaporin genes AQP2 and AQP3, and the potassium channel gene KCNE1. The aim of this study was to identify polymorphisms of these genes and determine their association with clinical characteristics of patients with MD. A case-control genetic association study was carried out, including 30 patients with definite Ménière's disease and 30 healthy controls. The coding regions of the target genes were amplified from blood samples by polymerase chain reaction (PCR), followed by direct sequencing. The associations of polymorphisms with clinical characteristics were analyzed with logistic regression. Five polymorphisms were identified: rs426496 in AQP2; rs591810 in AQP3; and rs1805127, rs1805128, and rs17173510 in KCNE1. After adjustment, rs426496 was significantly associated with tinnitus during the initial crisis and with altered electronystagmography, and rs1805127 was significantly associated with nephropathy. The genetic variant rs426496 in AQP2; rs591810 in AQP3 and rs1805127, rs1805128, and rs17173510, in KCNE1 were found in patients with Ménière's disease. The polymorphism rs426496, in AQP2, is associated with tinnitus at the onset of Ménière's disease and altered electronystagmography. In addition, rs1805127, in KCNE1, is associated with the presence of nephropathy.

Finance computationnelle et gestion des risques ingénierie financière avec applications Excel (Visual Basic) et Matlab

CERN Document Server

Racicot, François-Éric

2006-01-01

Ce manuel propose un exposé rigoureux de la gestion des risques en finance. Les aspects théoriques de la question sont abordés par des démonstrations claires et des rappels élaborés des bases mathématiques de la finance computationnelle. Le texte est émaillé de nombreux programmes écrits en langages Visual Basic (Excel), Matlab et EViews qui prépareront l'étudiant à sa carrière de spécialiste en ingénierie financière.

Absolute counting of 188Re radiopharmaceuticals

International Nuclear Information System (INIS)

Ravindra, Anuradha; Kulkarni, D.B.; Joseph, Leena; Kulkarni, M.S.

2018-01-01

Rhenium-188 is radiopharmaceutical that belongs to the group of strong beta-weak gamma emitters. It emits high energy beta particles, (E β m ax = 2.12MeV) and weak gamma rays (E γ = 155 keV) hence makes it suitable for wide variety of therapeutic as well as diagnostic applications. Therapeutic applications include therapy of tumors, radionuclide synovectomy, bone pain palliation, intra vascular radiation therapy etc. 188 Re-labeled medicines have been employed increasingly in the therapy of tumors and vascular restenosis. To ensure that patient receives the appropriate radiation dose during the treatment, both the activity standardization and the determination of sensitivity coefficient of the secondary standard for 188 Re have become important tasks. This paper presents the methods and results obtained for the following measurements a) Standardisation of the 188 Re by using the 4π proportional counter (4πPC)-gamma extrapolation method b) Determination of sensitivity coefficient (pA/MBq) of the secondary standard ionization chamber type Centronic IG12, 20A for 188 Re

Phase relations and superconductivity in the binary Re-Si system

International Nuclear Information System (INIS)

Jorda, J.L.; Ishikawa, M.; Muller, J.

1982-01-01

The phase diagram of the Re-Si system was reinvestigated by means of high temperature methods of analysis. Several modifications were found to the existing diagram. An extended rhenium solid solution (up to 10 at.% Si) was established with a rapid quenching technique. Within this terminal solid solution, the superconducting transition temperature increased from 1.7 to 5.2 K. The phase corresponding to the Re 5 Si 3 compound was homogeneous at 33 at.% Si. The peritectically formed equiatomic compound decomposed eutectoidally at 1650 0 C and was superconducting at 1.5 K. The compound ReSi 2 was found to be off stoichiometric, occurring at the composition ReSisub(1.8). (Auth.)