Color representation and interpretation of special effect coatings

A representation of the color gamut of special effect coatings is proposed and shown for six different samples, whose colors were calculated from spectral bidirectional reflectance distribution function (BRDF) measurements at different geometries. The most important characteristic of the proposed representation is that it allows a straightforward understanding of the color shift to be done both in terms of conventional irradiation and viewing angles and in terms of flake-based parameters. A different line was proposed to assess the color shift of special effect coatings on a*,b*-diagrams: the absorption line. Similar to interference and aspecular lines (constant aspecular and irradiation angles, respectively), an absorption line is the locus of calculated color coordinates from measurement geometries with a fixed bistatic angle. The advantages of using the absorption lines to characterize the contributions to the spectral BRDF of the scattering at the absorption pigments and the reflection at interference pigments for different geometries are shown.

Antonio Maura y el papel del II Reich en las negociaciones hispano-francesas sobre Marruecos de 1903-1904

En la primera parte del artículo se aborda el problema que ha de afrontar el estadista Antonio Maura al convertirse en el jefe del gobierno español, a finales de 1903 y consistente en concluir el proceso de negociación sobre Marruecos entablado con Francia desde 1901. Se resalta el carácter continuista del ideario colonial de Maura con respecto al del anterior líder conservador, Silvela, y la preponderancia de cuestiones como la seguridad nacional como motivadoras de dicho ideario. En la segunda parte, se explica la apelación del gobierno maurista a una ayuda por parte de Alemania, en función de movimientos previos de la diplomacia germana que se había interesado por controlar una parte del Marruecos español, o por conseguir compensaciones en Fernando Po. Finalmente se analiza el intento de Berlín de instrumentalizar al gobierno Maura en el curso de las conversaciones hispano-francesas sobre el Imperio jerifiano.

ConfChem Conference on A Virtual Colloquium to Sustain and Celebrate IYC 2011 Initiatives in Global Chemical Education—The Global Experiment of the IYC2011: Creating Online Communities for Education and Science

The Global Experiment, Water: A Chemical Solution, was one of the flagship activities of the International Year of Chemistry (IYC). During the virtual colloquium of the spring 2012 online ConfChem conference, the main results of this year-long experiment were presented and discussed online for a week. Some of the main conclusions of the virtual conversations relate to the benefits of creating online communities of people sharing similar interests, the use of online educational platforms to gather massive amounts of data, and specific questions about the development of this IYC initiative. The activities of the global water experiment (GWE) were designed by a team of experts and the protocols are available online on the GWE Web site. The results were shown in one interactive world map that allowed students to learn about data visualization, validation, and interpretation. The feedback obtained from the participants of the GWE and later by the contributors of the virtual colloquium was very positive. Many participants asked specific and technical questions about the development of this experiment, while others excitedly endorsed the convenience of these large open-access activities to promote chemistry worldwide. The estimate is that over 2 million people took part in the GWE during the IYC. This communication summarizes one of the invited papers to the ConfChem online conference: A Virtual Colloquium to Sustain and Celebrate IYC 2011 Initiatives in Global Chemical Education, held from May 18 to June 29, 2012 and hosted by the ACS DivCHED Committee on Computers in Chemical Education and the IUPAC Committee on Chemistry Education.