874 research outputs found

    Study of the charge profile of thermally poled electrets

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    The charge profile of thermally poled electrets has been studied using two different methods, laser induced pressure pulse (LIPP) and pulsed electroacoustic (PEA), to gain insight into the mechanisms that are activated and assess which is the most appropriate method to study the charge profile. Disc--shaped PET samples have been conventionally poled to activate both the alpha and the rho relaxation and, right after, partially discharged up to a temperature Tpd. In this way, samples with a different combination of dipolar and space charge polarization have been obtained. Both LIPP and PEA reveal asymmetric profiles for Tpd below the glass transition temperature, that progressively become antisymmetric for higher temperatures. The shape and evolution of the charge profiles can be explained assuming injection of negative carriers from the anode that enhances the trapping of positive carriers near this electrode. It can be observed that PEA is able to detect a wider variety of polarization mechanisms in the system while LIPP gives a simpler picture of the charge profile.Comment: 19 pages, 11 figure

    The Source of Maser Emission W33C (G12.8-0.2)

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    Results of observations of the maser sources toward the W33C region (G12.8-0.2) carried out on the 22-m radio telescope of the Pushchino Radio Astronomy Observatory in the 1.35-cm H2O line and on the Large radio telescope in Nancay (France) in the main (1665 and 1667 MHz) and satellite (1612 and 1720 MHz) OH lines are reported. Multiple, strongly variable short-lived H2O emission features were detected in a broad interval of radial velocities, from -7 to 55 km/s. OH maser emission in the 1667-MHz line was discovered in a velocity range of 35-41 km/s. Stokes parameters of maser emission in the main OH lines 1665 and 1667 MHz were measured. Zeeman splitting was detected in the 1665-MHz line at 33.4 and 39.4 km/s and in the 1667 MHz line only at 39.4 km/s. The magnetic field intensity was estimated. A appreciable variability of Zeeman splitting components was observed at 39 and 39.8 km/s in both main lines. The extended spectrum and fast variability of the H2O maser emission together with the variability of the Zeeman splitting components in the main OH lines can be due to the composite clumpy structure of the molecular cloud and to the presence in it of large-scale rotation and bipolar outflow as well as of turbulent motions of material.Comment: 7 pages, 2 tables, 8 figures, accepted by Astronomicheskii Zhurnal (Astronomy Reports

    Dimensión ética de la actividad socioeconómica

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    La realidad empírica de los fenómenos éticos sociales, que nadie niega y que es de inmediato conocimiento, lleva a reconocer -experimental, aunque no sensitivamente- la existencia de una moral socioeconómica de carácter objetivo. Los actos voluntarios de las personas no sólo producen una transformación ética en los individuos -se hacen buenos o malos-, sino también en las mismas instituciones sociales que, objetivamente, pueden ser mejores o peores; este carácter ético de las estructuras condiciona, pero no determina, las actuaciones morales personales. Por último, no basta demostrar la existencia de un verdadero saber científico en el campo de la moral socioeconómica: es necesario además -quizá en mayor medida- conocer y difundir sus criterios, y practicar -ayudando a que otros también lo hagan- sus directrices. Sólo de esta manera lograremos construir una civilización digna del hombre

    Trabajo y humanización de la persona

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    Observations of OH in comet Levy with the Nancay radio telescope

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    Due to extremely favorable excitation conditions, comet Levy (1990c) exhibited in August-September 1990 the strongest OH 18-cm signal ever recorded in a comet at the Nancay radio telescope. This unique opportunity was used to measure the OH satellite lines at 1612 and 1721 MHz, to perform extensive mapping of the OH radio emission and to make a sensitive evaluation of the cometary magnetic field, of the H2O outflow velocity and of the OH production rate

    Internet-based psychoeducation for bipolar disorder: a qualitative analysis of feasibility, acceptability and impact

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    <p>Background: In a recent exploratory randomised trial we found that a novel, internet-based psychoeducation programme for bipolar disorder (Beating Bipolar) was relatively easy to deliver and had a modest effect on psychological quality of life. We sought to explore the experiences of participants with respect to feasibility, acceptability and impact of Beating Bipolar.</p> <p>Methods: Participants were invited to take part in a semi-structured interview. Thematic analysis techniques were employed; to explore and describe participants’ experiences, the data were analysed for emerging themes which were identified and coded.</p> <p>Results: The programme was feasible to deliver and acceptable to participants where they felt comfortable using a computer. It was found to impact upon insight into illness, health behaviour, personal routines and positive attitudes towards medication. Many participants regarded the programme as likely to be most beneficial for those recently diagnosed.</p> <p>Conclusions: An online psychoeducation package for bipolar disorder, such as Beating Bipolar, is feasible and acceptable to patients, has a positive impact on self-management behaviours and may be particularly suited to early intervention. Alternative (non-internet) formats should also be made available to patients.</p&gt

    El argumento "personalista" en la encíclica Laborem exercens

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    La libre afirmación de nuestro ser. Una fundamentación de la ética realista [RESEÑA]

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