2,147 research outputs found

    Influence of roughness on conoscopic holography digitizing of DIN34CrMo4 surfaces

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    AbstractConoscopic Holography is a non-contact digitizing technique used in inspection and reverse engineering tasks. A laser beam is projected onto a surface, and its reflection generates a holographic pattern inside the sensor. This pattern is later analysed and the distance between sensor and surface is calculated. Like other optical techniques, conoscopic holography shall be affected by surface properties and ambient conditions. This works deals with the influence of surface roughness and manufacturing process on the quality of digitizing. 34CrMo4 steel test specimens have been manufactured to obtain four different Ra levels. Two different manufacturing process, electrical discharge machining (EDM) and ball-end milling (BEM) have been also considered. Quality of the digitized point clouds under different sensor configurations has been analysed, in order to provide a recommendation for optimal capture conditions

    Comparison of charge modulations in La1.875_{1.875}Ba0.125_{0.125}CuO4_4 and YBa2_2Cu3_3O6.6_{6.6}

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    A charge modulation has recently been reported in (Y,Nd)Ba2_2Cu3_3O6+x_{6+x} [Ghiringhelli {\em et al.} Science 337, 821 (2013)]. Here we report Cu L3L_3 edge soft x-ray scattering studies comparing the lattice modulation associated with the charge modulation in YBa2_2Cu3_3O6.6_{6.6} with that associated with the well known charge and spin stripe order in La1.875_{1.875}Ba0.125_{0.125}CuO4_4. We find that the correlation length in the CuO2_2 plane is isotropic in both cases, and is 259±9259 \pm 9 \AA for La1.875_{1.875}Ba0.125_{0.125}CuO4_4 and 55±1555 \pm 15 \AA for YBa2_2Cu3_3O6.6_{6.6}. Assuming weak inter-planar correlations of the charge ordering in both compounds, we conclude that the order parameters of the lattice modulations in La1.875_{1.875}Ba0.125_{0.125}CuO4_4 and YBa2_2Cu3_3O6.6_{6.6} are of the same order of magnitude.Comment: 3 pages, 2 figure

    Habilidades del psicólogo en drogodependencias

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    Las habilidades del terapeuta constituyen un aspecto fundamental para la consecución de los distintos objetivos que al psicólogo se le plantean en el transcurso de su intervención con el usuario drogodependiente. En este articulo se presenta una revisión de las habilidades que los autores consideran imprescindibles, aportando ejemplos prácticos y con independencia de la orientación teórica del psicólogo. Las habilidades técnicas o profesionales se refieren a conocimientos teóricos y prácticos; el afltocontrol emocional, incluyendo tanto el afrontamiento ef caz por parte del psicólogo de ciertas situaciones ante el usuario, y especificamente si éste es un drogodelincuente, como el afrontamiento del burn out; y por último, las habilidades sociales, en las que se sustenta la interacción entre el psicólogo y el usuario, destacando la asertividad y la empatia. Finalmente se revisan distintos aspectos y principios generales referidos a la ética profesional en la práctica de la Psicologia Clínica

    Influence of methane and carbon monoxide in the volumetric behaviour of the anthropogenic CO2: Experimental data and modelling in the critical region

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    Density measurements of the systems CO 2 + CH 4 at T = 304.21 K and CO 2 + CO at T = 304.21 and 308.15 K were carried out at pressures and compositions of interest in the process of transport and storage of CO 2 (CCS technology): P = 0.1 to 20 MPa, and xCO 2 ≥0.97. From the experimental P––T –xCO 2 data, we have studied the dependence of the isothermal compressibility, the excess molar volume, and the par- tial molar volume of the solute with composition, pressure and temperature within the critical region. We have modelled the volumetric behaviour of these systems with Peng–Robinson, PC-SAFT and GERG Equations of State, thus validating these equations under the conditions considered. Furthermore, we have confirmed the weakly attractive behaviour of these systems by performing a study of the interac- tions between solvent molecules, CO 2 , and those of the solute, CO or CH 4 , using the Krichevskii Function concept and the Kirkwood–Buff Theory. Finally, we have quantified the influence of small amounts of CH 4 and CO in the transport of anthropogenic CO 2 through several normalized parameters, related to the design and operation of the fluid transport process

    Parity-odd multipoles, magnetic charges and chirality in haematite (alfa-Fe2O3)

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    Collinear and canted magnetic motifs in haematite were investigated by Kokubun et al. (2008) using x-ray Bragg diffraction magnified at the iron K-edge, and analyses of observations led to various potentially interesting conclusions. We demonstrate that the reported analyses for both non-resonant and resonant magnetic diffraction at low energies near the absorption K-edge are not appropriate. In its place, we apply a radically different formulation, thoroughly tried and tested, that incorporates all magnetic contributions to resonant x-ray diffraction allowed by the established chemical and magnetic structures. Essential to a correct formulation of diffraction by a magnetic crystal with resonant ions at sites that are not centres of inversion symmetry are parity-odd atomic multipoles, time-even (polar) and time-odd (magneto-electric), that arise from enhancement by the electric-dipole (E1) - electric-quadrupole (E2) event. Analyses of azimuthal-angle scans on two space-group forbidden reflections, hexagonal (0, 0, 3)h and (0, 0, 9)h, collected by Kokubun et al. above and below the Morin temperature (TM = 250K), allow us to obtain good estimates of contributing polar and magneto-electric multipoles, including the iron anapole. We show, beyond reasonable doubt, that available data are inconsistent with parity-even events only (E1-E1 and E2- E2). For future experiments, we show that chiral states of haematite couple to circular polarization and differentiate E1-E2 and E2-E2 events, while the collinear motif supports magnetic charges

    High-pressure speed of sound in pure CO2 and in CO2 with SO2 as an impurity using methanol as a doping agent

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    Reliable speed of sound, c, values in CO2- rich mixtures and pure CO2 are required for carbon capture and storage (CCS) technology but are difficult to determine, particularly at relatively high frequencies. We tested the suitability of methanol as doping agent to obtain accurate c values in CCS systems at 5 MHz. We measured c in seven CO2-rich, CO2 + methanol mixtures between 263.15 and 323.15 K and up to 196.30 MPa, and we extrapolated the values to obtain c in pure CO2. Additionally, we measured c from 263.15 to 373.19 K and up to 190.10 MPa in two CO2-rich, CO2 + SO2 mixtures with the same SO2 composition, which is of interest for CCS, with one mixture doped with methanol. We compared our results for pure CO2 with the literature and the Span and Wagner equation of state (EoS). We validated the PC-SAFT EoS and the modeling with the REFPROP 9 software for the mixtures by comparing the predicted values with our experimental data under the studied conditions. We conclude that methanol is a suitable doping agent to measure c in pure CO2 and CO2-rich mixtures. For the CO2 + SO2 mixtures, the effect of methanol on the experimental values is small and negligible for modeling

    Insuficiencia cardíaca congestiva en la clínica de pequeños animales : terapéutica práctica moderna III. Diuréticos y bases xánticas en la clínica diaria

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    En el presente trabajo revisamos los medicamentos de efectos diuréticos más usados en la clínica de animales de compañía y aportamos nuestra experiencia personal en su uso y en la posible utilización de otros productos menos difundidos. Junto a ellos, y como una parte importante del tratamiento de muchos casos de insuficiencia cardíaca congestiva en el perro, una breve revisión de efectos, usos y problemas que pueden aportar las Xantinas de la clínica diaria.This paper reviews the diuretic drugs most often used in small animal practice and discloses the authors' personal experience in their application and the possible use of other less common products. A brief review of effects, uses and problems of Xantines in routine practice is also made, as an important element of the treatment of many cases of Congestivo Heart Failure in dogs

    Química de los cementos

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    En la presente comunicación se describen los resultados mas relevantes obtenidos a lo largo del tiempo en torno a algunas de las líneas de trabajo mas importantes que se desarrollan en el seno del grupo de investigación “Química del Cemento” del Instituto de Ciencias de la Construcción Eduardo Torroja (IETcc-CSIC).Edición financiada por el Ministerio de Educación y Ciencia con cargo al "Plan Nacional de I+D+I 2004-2007".Peer reviewe
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