2.3. Medium TestsThe duration of these tests is the time consumed for the machining along the length of the bar employed. The identification for these tests is MT-FFF-SSSS-DDD-L1/L2/..LN-G1/G2..GM, being:MT: Medium tests.FFF-SSSS-DDD: The same codes that in the short tests case. That is, values of the feed rate in mm/rev, values of the spindle speed in revolution per minute (rpm) and values of the depth of cut expressed in mm.L1/L2. LN: L is the longitudinal section of the bar on where the measurement is made and N is the total number of the sections considered (up to three are suggested).G1/G2. GM: G is the generatrix of the bar on where the measurement is made and M is the total number of generatrix considered (up to three are suggested).

For these types of tests, as surface roughness measurements are made on the workpiece, the last two alphanumeric codes have to be added in order to establish in which part of the workpiece the measurement is carried out.In Figure 1, a sketch of the workpiece is represented with the locat
This work presents a review of the analysis of cultural heritage using time-resolved photoluminescence spectroscopy (TRPL) and fluorescence lifetime imaging (FLIM) which we illustrate through applied case studies. Both techniques are non-destructive and based on the use of ps or ns pulsed lasers and gated detection for the analysis of range of organic and inorganic materials.1.1. Background of Photoluminescence Analysis of Works of ArtThe analysis of works of art often begins with the visual examination of the surface of an object under UV light.

This is because the spectrum of the optical emission from the surface as well as its spatial distribution in a field of view can provide conservators, art historians, and scientists key information regarding the presence of heterogeneities on a painting or a sculpture, signed papers or modern design objects. While the interpretation of fluorescence and the attribution of emissions to specific materials is far from trivial, both the spectrum of the emission, perceived as colour, and the spatial distribution of fluorescence are valuable starting points for further investigations. For example, conservators are experienced at relating differences in the fluorescence of surfaces to damage, to traces of materials (for example Batimastat organic binders) which may provide insights regarding degradation or to past interventions, to the local applications of varnish (which tends to develop fluorescence with age) or to the presence of retouching (which is often dark when examined under UV light).

Many materials found in cultural heritage fluoresce: indeed, stone substrates, organic pigments, binding media and waxes, conservation materials and semiconductors pigments have all been studied using fluorescence spectroscopy [1�C10].