The Servilia tomb: an architecturally and pictorially important Roman building

One hundred and eleven samples from the important Servilia Roman tomb have been analysed for the first time by Raman spectroscopy, resulting in a complete characterisation of the pigment palette used for its remarkable wall paintings: 73 different pigment mixtures have been identified for the composition of its 11 colours and their tonalities. Dyer’s weld, an ancient organic yellow pigment, which was described by Vitruvius, has been identified and characterised for the first time in Roman wall paintings. Distinctive Raman spectroscopic signals which differentiate between haematite and caput mortuum (a violet colour from haematite which has been subjected to thermal treatment) are also reported. The use of the very expensive lazurite for a balance relates the importance of this otherwise ordinary instrument with psychostasia (the human soul weighing process) and is not found elsewhere in the tomb. The distribution of white minerals alone or in admixture is not related to any particular colouring pigment or figure; this possibly indicates that there was no specific use for each white mineral and that several craftsmen worked on the paintings, perhaps in different periods, or that the frescoes have been subjected to unrecorded restoration. We conclude that Raman spectroscopy is a valuable analytical technique for the unambiguous identification of mixtures of both organic and inorganic compounds, to study the degree of mineral crystallinity and for identifying treatment. These data are relevant for the holistic interpretation of the artwork in its historical, economical and social context.     

Performing postcolonial identities at the United Nations’ climate negotiations

This study aims to understand how postcolonial identities were performed in the negotiations that led to the new climate agreement signed in Paris in December 2015. Based on interviews, the analysis of documents and participant observation of the negotiations it was possible to identify the legal, economic and scientific discourses mobilised by both global North and South countries. In all three discourses, it was possible to identify a systematic effort of the Northern parties to unmake the identity of Southern parties as ‘developing countries’ as a way to erase the ontological difference between emerging and established industrialised economies. At the same time, in the context of the convention Southern parties reaffirmed their identities as ‘developing countries’ and demanded from the North a strong commitment to tackle climate change and the transfer of more financial resources to the South. In this process, it was also possible to identify an inversion of the position usually taken by mainstream and critical postcolonial scholars that see the deconstruction of categories such as ‘developing countries’ as key for the emancipation of the global South. Finally, this invites postocolonial scholars to look more closely at how postcolonial identities are being instrumentalised, discursively and politically.     

A sweet and amnesic present: the postcolonial landscape and memory makings in Cape Verde

The construction of memory in landscapes is a complex process which is embedded in webs of political and economic power. Often history is twisted and bended to better serve the current interests of the hegemonic forces at play. In this paper I attempt to explore how memory is at work in three different sites in Santiago Island, Cape Verde: an old fort and a historical town; a concentration camp; and a global resort. The three sites participate in the erasure, maintenance and creation of memory in different ways, forging new forms of collective identity, which are embedded in local as well as global forces and processes. Through an analysis of the changes taking place on these sites, this paper suggests that while the country lives on foreign aid and attempts to embrace neo-liberal practices, it fails not only to provide basic services to the population but to engage critically with its history and geography.     

Seismic Tests and Numerical Modeling of a Rolling-ball Isolation System

For the seismic isolation of light structures, the use of laminated rubber bearings is neither economical nor, for most cases, technically suited. For the isolation of this type of structure a new system, consisting of steel balls rolling on rubber tracks, has been developed at TARRC (Tun Abdul Razak Research Centre).

This article presents the results of experimental tests carried out for the characterization of the behavior of this new device. A numerical model is also proposed that can be used to assess the seismic response of structures with this isolation system.

Comparison of the predictions of the numerical model with the experimental data shows that the model is adequate to perform the correct assessment of the seismic response of isolated structures. The results of the experimental campaign of shaking-table tests, as well as the numerical simulations, show that there is an effective reduction of the acceleration levels induced in the isolated structures.     

Statistical Characterization of Structural Demand under Earthquake Loading. Part 1: Robust Estimation of the Central Value of the Data

This article is the first of two companion articles addressing the statistical characterization of seismic demand. Performance-based earthquake engineering methodologies often require the characterization of central value estimates of structural demand. Since outliers can occur in the data, central value estimates should be determined by robust estimation methods. The performance of 50 robust central value estimators is evaluated, for different sample sizes, using the chord rotation, curvature, shear force, and inter-story drift demands obtained after analyzing five reinforced concrete structures under real earthquake records scaled to several intensities. Based on the results, seven estimators are proposed for different sample sizes.