Las huellas del tiempo en la arquitectura moderna intervenida

Algunas obras ejemplares del Movimiento Moderno, como son: el Sanatorio en Hilversum, la Escuela de la Bauhaus, la Villa Savoye o el Pabellón de Alemania, etc., han sido intervenidas. ¿Qué criterios se han seguido? ¿Han sido los mismos? ¿Cuáles han sido los prioritarios? Sea mediante restauraciones o reconstrucciones parciales o totales, los criterios que más han prevalecido devuelven las obras al origen, por lo menos en la forma. Resulta significativo que lo que más ha motivado estas intervenciones sea el avanzado deterioro debido, en muchos casos, a la debilidad de las soluciones constructivas empleadas que no han superado el medio siglo. ¿Es el movimiento moderno patrimonio? ¿Qué diferencia hay entre esta arquitectura moderna y la histórica que la precedió? Si se considera que ambas son portadoras de los valores culturales de su época, ¿por qué se aplican criterios distintos en cada caso? ¿Por qué sobre el patrimonio histórico prima el diferenciar el tiempo de la actuación mientras que sobre el patrimonio moderno se tiende a borrar las huellas del tiempo mediante la restauración arqueológica? ¿Cuánto no hay de contradictorio con los fundamentos del Movimiento Moderno en esta fosilización?.

Conversion of a digital camera into a non-contact colorimeter for use in stone cultural heritage: The application case to Spanish granites

In this study, a digital CMOS camera was calibrated for use as a non-contact colorimeter for measuring the color of granite artworks. The low chroma values of the granite, which yield similar stimulation of the three color channels of the camera, proved to be the most challenging aspect of the task. The appropriate parameters for converting the device-dependent RGB color space into a device-independent color space were established. For this purpose, the color of a large number of Munsell samples (corresponding to the previously defined color gamut of granite) was measured with a digital camera and with a spectrophotometer (reference instrument). The color data were then compared using the CIELAB color formulae. The best correlations between measurements were obtained when the camera works to 10-bits and the spectrophotometric measures in SCI mode. Finally, the calibrated instrument was used successfully to measure the color of six commercial varieties of Spanish granite.

Population synthesis of isolated neutron stars with magneto-rotational evolution – II. From radio-pulsars to magnetars

Population synthesis studies constitute a powerful method to reconstruct the birth distribution of periods and magnetic fields of the pulsar population. When this method is applied to populations in different wavelengths, it can break the degeneracy in the inferred properties of initial distributions that arises from single-band studies. In this context, we extend previous works to include X-ray thermal emitting pulsars within the same evolutionary model as radio-pulsars. We find that the cumulative distribution of the number of X-ray pulsars can be well reproduced by several models that, simultaneously, reproduce the characteristics of the radio-pulsar distribution. However, even considering the most favourable magneto-thermal evolution models with fast field decay, lognormal distributions of the initial magnetic field overpredict the number of visible sources with periods longer than 12 s. We then show that the problem can be solved with different distributions of magnetic field, such as a truncated lognormal distribution, or a binormal distribution with two distinct populations. We use the observational lack of isolated neutron stars (NSs) with spin periods P > 12 s to establish an upper limit to the fraction of magnetars born with B > 1015 G (less than 1 per cent). As future detections keep increasing the magnetar and high-B pulsar statistics, our approach can be used to establish a severe constraint on the maximum magnetic field at birth of NSs.