101 research outputs found
“La fraseología en tres diccionarios fraseológicos del español
No full textResumen: La fraseología está cobrando cada vez más mayor visibilidad y atención en la lexicografía. Los diccionarios específicos de fraseología representan un modelo para las obras bilingües (www.contrastiva.it). Nuestro objetivo es estudiar su tratamiento en tres obras esenciales de la lexicografía monolingüe peninsular: el Diccionario fraseológico del español moderno de Varela y Kubart (1994), el Diccionario fraseológico documentado del español actual de Manuel Seco (2004) y el Diccionario de expresiones y locuciones del español de Martínez López y Myre (2009). Se atenderá a la información contenida tanto en la macroestructura (definición de fraseología, clasificación, marcación, ejemplos) como en la microestructura
Broadband optical absorption caused by plasmonic response of coalesced Au nanoparticles embedded in a TiO2 matrix
No full textThe effect of Au nanoparticles (NPs) concentration, size and spatial distribution within a TiO2
dielectric matrix on the Localized Surface Plasmon Resonance (LSPR) band characteristics, were
experimentally and theoretically studied. The results of the analysis of the Au NPs’ size
distributions allowed to conclude that isolated NPs grow only up to 5-6 nm in size, even for the
highest annealing temperature used. However, for higher volume fractions of Au, the coalescence of
closely located NPs yields elongated clusters, which are much larger in size and cause a
considerable broadening of the LSPR band. This effect was confirmed by Monte Carlo modeling
results. Coupled dipole equations were solved to find the electromagnetic modes of a supercell,
where isolated and coalesced NPs were distributed, from which an effective dielectric function of
the nanocomposite material was calculated and used to evaluate the optical transmittance and
reflectance spectra. The modeling results suggested that the observed LSPR band broadening is due
to a wider spectral distribution of plasmonic modes, caused by the presence of coalesced NPs (in
addition to the usual damping effect). This is particularly important for detection applications via
Surface-Enhanced Raman Spectroscopy (SERS), where it is desirable to have a spectrally broad
LSPR band in order to favor the fulfillment of the conditions of resonant matching, to electronic
transitions in detected species.This research was sponsored by FEDER funds through the COMPETE program (Programa
Operacional Factores de Competitividade) and by FCT (Fundação para a Ciência e a Tecnologia),
under the projects PEST-C/FIS/UI607/2013, UID/EMS/00285/2013 and PEst-OE/MAT/UI0013/2014. The authors also acknowledge the financial support by the project ESF
Research Networking Programme PLASMONBIONANOSENSE. J. Borges also acknowledges the
support by the European social fund within the framework of realizing the project “Support of inter
sectoral mobility and quality enhancement of research teams at Czech Technical University in
Prague”, CZ.1.07/2.3.00/30.0034
Body suspension: performativita bolesti
No full textVe studii "Body suspension: performativita bolesti" se pokouším téma tělesného zavěšování (body suspension) předestřít v nepříliš problematizované podobě co nejširší odborné čtenářské obci, s ohledem na vlastní východiska, jež pramení především v teatrologii a dílčích otázkách teatrality a performativity (Fischer-Lichte, Judith Butler). V českém prostředí dosud odborně nereflektované téma vykazuje velmi zajímavé znaky, jež by měly upoutat každého divadelního vědce, antropologa, etnologa či kulturologa. Kontext a vzájemné souvislosti jednotlivostí fenoménu body suspension jsou natolik komplexní, že si jistě zasluhují první akademické texty. Má studie je kompilátem základních informačních zdrojů a vlastního výzkumu v českých a slovenských komunitách zabývajících se body suspension.In the study the author strives to present the topic of body suspension to wide professional Czech public, to which it has been practically unknown, with regard to methodology of theatre and performance studies (Erika Fischer-Lichte, Judith Butler). The phenomenon bears a number of features interesting especially from the perspective of Theatre and Performance Studies, Anthropology, Ethnology, and Culturology. The study is supposed to attract interest of professional public to this complex phenomenon, presenting it with help of foreign secondary sources and the author's own research of Czech and Slovak body suspension communities
Thin films composed of Ag nanoclusters dispersed in TiO2: Influence of composition and thermal annealing on the microstructure and physical responses
No full textNoble metal powders containing gold and silver have been used for many centuries, providing different colours in the windows of the medieval cathedrals and in ancient Roman glasses. Nowadays, the interest in nanocomposite materials containing noble nanoparticles embedded in dielectric matrices is related with their potential use for a wide range of advanced technological applications. They have been proposed for environmental and biological sensing, tailoring colour of functional coatings, or for surface enhanced Raman spectroscopy. Most of these applications rely on the so-called localised surface plasmon resonance absorption, which is governed by the type of the noble metal nanoparticles, their distribution, size and shape and as well as of the dielectric characteristics of the host matrix. The aim of this work is to study the influence of the composition and thermal annealing on the morphological and structural changes of thin films composed of Ag metal clusters embedded in a dielectric TiO2 matrix. Since changes in size, shape and distribution of the clusters are fundamental parameters for tailoring the properties of plasmonic materials, a set of films with different Ag concentrations was prepared. The optical properties and the thermal behaviour of the films were correlated with the structural and morphological changes promoted by annealing. The films were deposited by DC magnetron sputtering and in order to promote the clustering of the Ag nanoparticles the as-deposited samples were subjected to an in-air annealing protocol. It was demonstrated that the clustering of metallic Ag affects the optical response spectrum and the thermal behaviour of the films
Large-area homogeneous periodic surface structures generated on the surface sputtered boron carbide thin films by femtosecond laser processing
No full textAmorphous and crystalline sputtered boron carbide thin films have a very high hardness even surpassing that of bulk crystalline boron carbide (approximate to 41 GPa). However, magnetron sputtered B-C films have high friction coefficients (C.o.F) which limit their industrial application. Nanopatterning of materials surfaces has been proposed as a solution to decrease the C.o.F. The contact area of the nanopatterned surfaces is decreased due to the nanometre size of the asperities which results in a significant reduction of adhesion and friction. In the present work, the surface of amorphous and polycrystalline B-C thin films deposited by magnetron sputtering was nanopatterned using infrared femtosecond laser radiation. Successive parallel laser tracks 10 mu m apart were overlapped in order to obtain a processed area of about 3 mm(2). Sinusoidal-like undulations with the same spatial period as the laser tracks were formed on the surface of the amorphous boron carbide films after laser processing. The undulations amplitude increases with increasing laser fluence. The formation of undulations with a 10 mu m period was also observed on the surface of the crystalline boron carbide film processed with a pulse energy of 72 mu J. The amplitude of the undulations is about 10 times higher than in the amorphous films processed at the same pulse energy due to the higher roughness of the films and consequent increase in laser radiation absorption. LIPSS formation on the surface of the films was achieved for the three B-C films under study. However, LIPSS are formed under different circumstances. Processing of the amorphous films at low fluence (72 mu J) results in LIPSS formation only on localized spots on the film surface. LIPSS formation was also observed on the top of the undulations formed after laser processing with 78 mu J of the amorphous film deposited at 800 degrees C. Finally, large-area homogeneous LIPSS coverage of the boron carbide crystalline films surface was achieved within a large range of laser fluences although holes are also formed at higher laser fluences.</p
Reactive sputtering of precursors for Cu2ZnSnS4 thin film solar cells
No full textThe quaternary semiconductor Cu2ZnSnS4 (CZTS) is a possible In-free replacement for Cu(In,Ga)Se-2. Here we present reactive sputtering with the possibility to obtain homogeneous CZTS-precursors with tunable composition and a stoichiometric quantity of sulfur. The precursors can be rapidly annealed to create large grained films to be used in solar cells. The reactive sputtering process is flexible, and morphology, stress and metal and sulfur contents were varied by changing the H2S/Ar-flow ratio, pressure and substrate temperature. A process curve for the reactive sputtering from CuSn and Zn targets is presented. The Zn-target is shown to switch to compound mode earlier and faster compared to the CuSn-target. The precursors containing a stoichiometric amount of sulfur exhibit columnar grains, have a crystal structure best matching ZnS and give a broad peak, best matching CZTS, in Raman scattering. In comparing process gas flows it is shown that the sulfur content is strongly dependent on the H2S partial pressure but the total pressures compared in this study have little effect on the precursor properties. Increasing the substrate temperature changes the film composition due to the high vapor pressures of Zn, SnS and S. High substrate temperatures also give slightly denser and increasingly oriented films. The precursors are under compressive stress, which is reduced with higher deposition temperatures. (C) 2012 Elsevier B.V. All rights reserved
Am. J. Hum. Genet.
No full textX-linked West syndrome, also called "X-linked infantile spasms" (ISSX), is characterized by early-onset generalized seizures, hypsarrhythmia, and mental retardation. Recently, we have shown that the majority of the X-linked families with infantile spasms carry mutations in the aristaless-related homeobox gene (ARX), which maps to the Xp21.3-p22.1 interval, and that the clinical picture in these patients can vary from mild mental retardation to severe ISSX with additional neurological abnormalities. Here, we report a study of two severely affected female patients with apparently de novo balanced X;autosome translocations, both disrupting the serine-threonine kinase 9 (STK9) gene, which maps distal to ARX in the Xp22.3 region. We show that STK9 is subject to X-inactivation in normal female somatic cells and is functionally absent in the two patients, because of preferential inactivation of the normal X. Disruption of the same gene in two unrelated patients who have identical phenotypes (consisting of early-onset severe infantile spasms, profound global developmental arrest, hypsarrhythmia, and severe mental retardation) strongly suggests that lack of functional STK9 protein causes severe ISSX and that STK9 is a second X-chromosomal locus for this disorder
Localised modifications of anatase TiO2 thin films by a Focused Ion Beam
No full textA Focused Ion Beam (FIB) has been used to implant micrometer-sized areas of polycrystalline anatase TiO2 thin films with Ga+ ions using fluencies from 10(15) to 10(17) ions/cm(2). The evolution of the surface morphology was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). In addition, the chemical modifications of the surface were followed by X-ray photoelectron spectroscopy (XPS). The implanted areas show a noticeable change in surface morphology as compared to the as-deposited surface. The surface loses its grainy morphology to gradually become a smooth surface with a RMS roughness of less than 1 nm for the highest ion fluence used. The surface recession or depth of the irradiated area increases with ion fluence, but the rate with which the depth increases changes at around 5 x 10(16) ions/cm(2). Comparison with implantation of a pre-irradiated surface indicates that the initial surface morphology may have a large effect on the surface recession rate. Detailed analysis of the XPS spectra shows that the oxidation state of Ti and O apparently does not change, whereas the implanted gallium exists in an oxidation state related to Ga2O3.</p
J/psi production versus centrality, transverse momentum, and rapidity in Au+Au collisions at root S(NN) = 200 GeV
No full textThe PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured J/psi production for rapidities -2.2 < y < 2.2 in Au+Au collisions at root s(NN)=200 GeV. The J/psi invariant yield and nuclear modification factor R-AA as a function of centrality, transverse momentum, and rapidity are reported. A suppression of J/psi relative to binary collision scaling of proton-proton reaction yields is observed. Models which describe the lower energy J/psi data at the CERN Super Proton Synchrotron invoking only J/psi destruction based on the local medium density predict a significantly larger suppression at RHIC and more suppression at midrapidity than at forward rapidity. Both trends are contradicted by our data
Annealing behavior of reactively sputtered precursor films for Cu2ZnSnS4 solar cells
No full textReactively sputtered Cu–Zn–Sn–S precursor films are prepared and recrystallized by rapid thermal processing to generate Cu2ZnSnS4 solar cell absorber layers. We study how the film properties are affected by substrate heating and composition. The stress, density and texture in the films were measured. Compressive stress was observed for the precursors but did not correlate to the deposition temperature, and had no influence on the properties of the annealed films or solar cells. However, the substrate temperature during precursor deposition had a large effect on the behavior during annealing and on the solar cell performance. The films deposited at room temperature had, after annealing, smaller grains and cracks, and gave shunted devices. Cracking is suggested to be due to a slightly higher sulfur content, lower density or to minor differences in material quality. The grain size in the annealed films seems to increase with higher copper content and higher precursor deposition temperature. The best device in the current series gave an efficiency of 4.5%
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