1,720,975 research outputs found
Sol-gel hybrid materials for aerospace applications: Chemical characterization and comparative investigation of the magnetic properties
No full textChemical characterization and magnetic properties of hybrid materials obtained via sol-gel route
No full textSynthesis and characterisation of La1-xNaxMnO3+delta thin films manganites
No full textptimally sodium doped lanthanum manganite (LNMO) thin films have been grown onto differently oriented NdGaO3 single crystals substrates by means of radio-frequency (RF)-magnetron sputtering technique, in order to investigate the role of the strain imposed by lattice mismatch on the magnetotransport properties. Films deposited onto NdGaO3 (I 10) experiment a slight in-plane compressive strain that can be tuned by the thickness and allows to achieve colossal magnetoresistive effects. On the contrary, the change of the substrate orientation induces an in-plane tensile strain, making the film insulating. Above observations are explained by considering the effect of distortions of the Mn-O coordination polyhedra
Preparation, structural and magnetic characterisation of RF-sputtered La1-xNaxMnO3 +/-delta thin films manganites
No full textIn this paper we report about the synthesis and characterisation of the structure and magnetic properties of sodium doped LaMnO3 thin films prepared by means of RF-magnetron sputtering. The synthesis was realised at two different substrate temperatures (500 and 700°C) and with different gas chamber compositions. The role of oxygen content variation has been checked by annealing the thin films at different oxygen partial pressures. By reducing the oxygen content an increase of the distortion in the film has been observed together with a reduction of the Curie temperatures. Films with high Curie temperatures (250 K) have been prepared at 700°C in pure argon
ZrO2/PEG hybrid nanocomposites synthesized via sol-gel: Characterization and evaluation of the magnetic properties
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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
Structure and magnetic properties of SiO2/PCL novel sol-gel organic-inorganic hybrid materials
No full textOrganic-inorganic nanocomposite materials have been synthesized via sol-gel. They consist of an inorganic SiO2 matrix, in which different percentages of poly(e-caprolactone) (PCL) have been incorporated. The formation of H-bonds among the carbonyl groups of the polymer chains and Si-OH group of the inorganic matrix has been proved by means of Fourier transform infrared spectroscopy (FT-IR) analysis and has been confirmed by solid-state nuclear magnetic resonance (NMR). X-Ray diffraction (XRD) analysis highlighted the amorphous nature of the synthesized materials. Scanning electron microscope (SEM) micrograph and atomic force microscope (AFM) topography showed their homogeneous morphology and nanostructure nature. Considering the opportunity to synthesize these hybrid materials under microgravity conditions by means of magnetic levitation, superconducting quantum interference device (SQUID) magnetometry has been used to quantify their magnetic susceptibility. This measure has shown that the SiO2/PCL hybrid materials are diamagnetic and that their diamagnetic susceptibility is independent of temperature and increases with the PCL amount
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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