Effect of organic and inorganic consolidation agents on Tlaltecuhtli monolith

A huge monolithic piece corresponding to the first years of the sixteenth century has been discovered in Mexico City. It represents the earth goddess Tlaltecuhtli. The preservation of such a magnificent piece is imperative. Therefore, the surface has to be characterized and the interaction of consolidants with the rock has to be understood.Some of the consolidation methods are impregnation of the mineral with nopal or silicic acid derivatives. In this work we compare the physico-chemical effects of organic and inorganic consolidants. Original and impregnated samples are characterized with a series of original techniques: X-ray diffraction, nuclear magnetic resonance, nitrogen adsorption and small angle X-ray scattering. Fractal dimension, specific surface area and pore size distribution clearly differentiated the samples. The organic materials, nopal gum or slobber, cover the mineral particles with a smooth layer. The KSE solutions react and lead to microporosity.     

On Language, Culture, and Social Action

This article outlines the theoretical developments experienced in historical studies over the last two decades. As a consequence of the growing critical reconsideration of some of the main theoretical assumptions underlying historical explanation of individuals' meaningful actions, a new theory of society has taken shape among historians during this time. By emphasizing the empirical and analytical distinction between language as a pattern of meanings and language as a means of communication, a significant group of historians has thoroughly recast the conventional notions of society, experience, interests, culture, and identity, and has developed a new concept of social action. Thus, historiographical debate seems to have started to transcend, for the first time, the longstanding and increasingly futile contest or dilemma between objectivism and subjectivism, between materialism and culturalism, between social and intentional explanation, or between social constraints and human agency. The groundwork has now been laid for an alternative to the declining paradigm of social history that does not entail a revisionist return (be it partial or complete) to idealist history but opens a quite different path.     

Building synergies between WTO and UNESCO: the case for data-driven policy coordination

The different legal worldviews of WTO and UNESCO on trade and culture vividly illustrate the formidable challenges we face nowadays to deliver legal and policy coherence in global governance. Bridging the trade and culture policy divide in this area requires stronger inter-agency dialog and cooperation, starting with joint initiatives for improved policy-oriented statistics.     

Rocking of Non-symmetric Rigid Blocks in Buildings Considering Effects Associated with Dynamic Soil-Structure Interaction

A dynamic model for the estimation of the rocking and/or overturning response of a free-standing non-symmetric rigid block considering rotational and horizontal excitation is proposed. The block is situated at different levels of a building with flexible base subjected to earthquakes. Base flexibility introduces the rotational component of the excitation due to dynamic soil-structure interaction (DSSI). The model is used to assess the influence of the dynamic soil-structure interaction on the behavior of the block. An illustrative example of the proposed model for non-symmetric rigid blocks in 5-, 10-, and 15-story buildings located in soft soils considering earthquakes from different seismic sources is presented. Results show that it is important to consider kinematic effects as well as inertial effects of DSSI in the dynamic response of contents. The influence of base flexibility depends on the change of spectral intensities associated to the increase of the building structural period and is larger for higher building levels.     

A Data-based Probabilistic Approach for the Generation of Spectra-Compatible Time-History Records

A data-based procedure is presented to develop spectra-compatible time-history records that are based on the dominant probabilistic features of an ensemble of records corresponding to the non-stationary stochastic phenomena of interest (e.g., earthquakes, wind loads, etc). The method requires a statistically significant collection of time-history records that are used to construct the associated covariance kernel of the random process. Subsequently, orthogonal decomposition approaches are used to determine the dominant eigenvectors of the covariance matrix, and these vectors are then linearly combined, with an adjustable amplitude-scale and phase-shift, to determine, via a nonlinear optimization scheme (employing a combination of stochastic and deterministic approaches), a time-history record that matches the target spectrum within a specified error bound. The utility of this approach is demonstrated with several collections of earthquake records from different regions of the world (Japan, Los Angeles, and San Francisco) that are then used to match various spectra widely used in seismic design applications. Issues that impact the selection of the bases vectors to construct the optimum spectra-matching record are discussed, and guidelines are provided for successful implementation of the proposed methodology.     

Protocol,Potentials, and Limitations of Ancient Teeth 3D Printing

Bioarchaeological analyses of teeth rely traditionally on noninvasive methods that reveal essential information about past individuals and populations. Methodological developments have revolutionized the discipline, but their application is commonly invasive and destructive. The resulting loss of material and information can be buffered through 3D technology applications. Although useful, it is essential that we carefully assess the reliability of these methods, in order to understand what data are preserved and which ones are lost through their application. This study offers a protocol for the implementation of 3D technology in the fabrication of ancient teeth analogs. Analog accuracy was assessed by comparing metric and non-metric traits between the originals and their respective analogs. Results showed that metric traits preserved well, but the preservation of non-metric traits was partially hindered.     

Investigation Techniques for the Seismic Response Assessment of Buildings Located in Historical Centers

ABSTRACT

It is an acknowledged fact that historical centers, given its significance from the cultural and architectural viewpoint, bring further challenges in terms of maintenance planning, survey, and safety assessment. The preparation of an adequate investigation plan and the extent of data to be collected is highly reliant on many aspects, such as the category of the architectonic asset, the importance of the heritage site, or the resources available, for example. In what regards the seismic response assessment of urban cultural heritage assets located in historical centers, the amount and detail of data also depend on this article, scale of assessment, and current state of conservation and occupation. Within this framework, this article provides an overview of the state of the art of investigation techniques currently used in survey operations, which are currently available for improving the knowledge level of urban cultural heritage assets within historical centers, as a supporting tool for the seismic response assessment of such singular assets. Finally, acknowledging the lack of accuracy when evaluating the seismic response of an asset enclosed in aggregate as an isolated structure, this article also focuses on the identification of the main particularities inherent to buildings enclosed in aggregate.     

Egyptian sculptures from Imperial Rome. Non-destructive characterization of granitoid statues through macroscopic methodologies and in situ XRF analysis

Aegyptiaca-like Domitian’s obelisk is now decorating Bernini’s fountain on Piazza Navona or the Egyptian lions flanking Michelangelo’s stairs towards the Capitol figure prominently amidst Rome’s cultural heritage. Motivations for the import, contextualization, and copying of these objects during the Imperial Roman period are as heavily debated as they are ill understood. Provenance determination plays an important role in these discussions in terms of a (supposed) dichotomy between Egyptian (real) versus egyptianising (copy) but has only been applied stylistically and never been tested analytically. A scientific characterization of the materials themselves is even lacking altogether, as is an investigation into the cultural and symbolic meaning of the materials used. This paper is a first attempt to address these important lacunae on the basis of an explorative study of a selected sample of Egyptian statues from Rome. The identification and provenance attribution of the materials used for these statues are often problematic due to their relatively fine-grained nature and dark color. Therefore, a full non-destructive analysis of Egyptian statues in dark-colored rocks is presented in this study, with the stones evaluated by macroscopic examination and handheld X-ray fluorescence (XRF) analysis. The implemented methodology has allowed a distinction between greywacke and several varieties of granitoid rocks. In order to evaluate the potential for source attribution, a comparison was made between the results of our analyses and geochemical data for several granitoid rocks from Egypt. This has suggested Aswan as most likely source. The results presented here indicate that handheld XRF analysis can be used for the assessment of compositional variability in and potentially for the provenance of granitoid rocks, provided that a fine-grained area of the material can be measured on multiple locations, and if these values can be assessed on (in)consistencies with other published reference materials.