1,721,007 research outputs found
The use of the small caliber JJ stent with anti-reflux valve in double kidney transplant. Personal experience
No full textRAMAN-SPECTROSCOPY OF HTAMO6.XH2O (M=W AND TE) PYROCHLORES AND THEIR POTASSIUM PRECURSORS
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CADMIUM-ION DISTRIBUTION AND MOTION IN BETA-ALUMINA - AN X-RAY-DIFFRACTION AND RAMAN-SCATTERING INVESTIGATION
No full textThe structure and dynamics of a mixed cadmium-sodium β-alumina crystal, with composition (Cd0.79Na0.42O)1.22⋅11Al2O3, was investigated by x-ray diffraction and Raman spectroscopy. The conventional crystal-structure determination was carried out at room temperature, attaining R=0.043 in the least-squares refinement. Cadmium ions are close to mid-oxygen sites, but displaced by 0.168(5) Å from the conduction plane. Sodium ions are located in 6h sites near the Beevers-Ross positions, and the bridging oxygen atoms are disorderly distributed slightly off the threefold axes. Al interstitial-vacancy pairs correlated with oxygen interstitials were detected. Polarized Raman spectra, obtained in the low-frequency region at some temperatures from 300 K down to liquid-helium temperature region, are analyzed. The results of the analysis of features connected with cadmium-ion vibrational dynamics in room-temperature spectra are consistent with the model of ionic distribution obtained by refining x-ray-diffraction data. The temperature evolution of some Raman bands is discussed in terms of cadmium-ion rearrangement
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Kinetics of deuteration of the Pd0.772Ag0.228 alloy with α/β phase transition by in-situ neutron diffraction
Full text linkThe deuteration reaction of a Pd0.772Ag0.228 foil was studied by neutron powder diffraction measurements vs. time in different T and p(D-2) conditions (D20 and D2B high-resolution diffractometers at ILL, France). The system has great importance as permeable membrane for hydrogen separation. At p = 1 bar and T < 200 degrees C Bragg peak splitting indicates the presence of two cubic phases, to be identified with the a and beta modifications of palladium hydride. Rietveld refinements provided the corresponding a(alpha), and a(beta) lattice constants, the nu(alpha), and nu(beta) occupancies of D, and the beta phase volume fraction vs. time during deuteration progress. A continuous alpha -> beta transformation takes place till reaction end. At T= 200 degrees C or p> 1 bar a single phase was always observed. The phase diagram of Pd0.772Ag0.228D nu is thus shown to present a alpha+beta two-phase domain less extended but similar to that of PdH nu, at variance with most thermodynamic measurements suggesting full single-phase behavior. The p(t) kinetic data of deuteration at 80 degrees C/1 bar can be interpreted by a mechanism based on a first-order nucleation step followed by a zero-order step of surface adsorption and dissociation of the D-2 molecule. (C) 2019 Elsevier B.V. All rights reserved
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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