Evaluation of portable Raman spectroscopy and handheld X-ray fluorescence analysis (hXRF) for the direct analysis of glyptics

In archaeometry, the advantages of a combined use of Raman spectroscopy and X-ray fluorescence spectroscopy are extensively discussed for applications such as the analysis of paintings, manuscripts, pottery, etc. Here, we demonstrate for the first time the advantage of using both techniques for analysing glyptics. These engraved gemstones or glass materials were originally used as stamps, to identify the owner, for instance on letters, but also on wine vessels. For this research, a set of 64 glyptics (42 Roman glass specimens and 22 modern ones), belonging to the collection of the museum ‘Quinta das Cruzes’ in Funchal (Madeira, Portugal), was analysed with portable Raman spectroscopy and handheld X-ray fluorescence (hXRF). These techniques were also used to confirm the gemological identification of these precious objects and can give extra information about the glass composition. Raman spectroscopy identifies the molecular composition as well as on the crystalline phases present. On the other hand, hXRF results show that the antique Roman glass samples are characterised with low Pb and Sn levels and that the modern specimens can be discriminated in two groups: lead-based and non-lead-based ones.

La población estudiantil en el sétimo año de la educación pública costarricense

Seventh grade students share personal characteristics that are analyzed in this paper based on the teachers´ performance of the proper mediation for the students´ learning. The results of an investigation done with the model of teachers´ profiles at this level will be the basis for this paper (Alfaro et al, 2008a). We conclude that the biopsychosocial development and maturational stage of the transit-preteen-teen children must be the domain of faculty at this level, as well as, the socioeconomic context of family and social contexts of their students.

Intercambio de experiencias de capacitación y de práctica profesional

The present article arises from the implementation of the Academic Exchange project between the Division de Educación Rural (Rural Education School) from Universidad Nacional and other collaborating schools. There are two fundamental actions that are approached; first, the theoretical methodological conception of the professional field practicum of the DER and second, the teaching training to rural teachers in service. From these academic activities, products developed are exposed in the project and some reflections about the academic experience were also exposed as a result of lessons learned during the whole process.