Identifying a technological style in the making of lime plasters at Teopancazco (Teotihuacan,México)

The aim of this article is to focus on the technology of archeological plasters at Teotihuacan (Central Mexico), from the Classic Period (200–650 A.D.), focusing in the study of Teopancazco, a neighborhood center in the city. Petrographic and chemical analyses by OM, SEM-EDS, and LA-ICP-MS were conducted to characterize samples from different constructive phases and sectors of the neighborhood center, to determine the provenance of the raw materials employed in the manufacturing (e.g., volcanic glass shards) and to assess whether a shift occurred in the manufacturing of plasters and in the procurement strategies of raw materials during the different phases. The results of the analyses show that almost no changes occurred in the making of the plaster during more than four centuries and allow us to consider the presence of a technological style in their manufacture, which is characterized by the making of plaster by mixing lime with volcanic glass shards, which in the case of Teopancazco were derived from the Altotonga (Veracruz) magmatic system. The data at our disposal suggest that this style was developed in Teopancazco and later introduced throughout the city of Teotihuacan in the Early Xolalpan phase (A.D. 350), although we still do not know whether the provenance of the raw materials is the same. The wide distribution of this technological tradition could be due to the technological properties of the materials and/or the influence of the intermediate elite who ruled over Teopancazco. The paper confirms that the study of material culture and technology sheds light on broader cultural aspects of ancient societies.     

From Neo-Francoist Memory to Political Feeling in Narratives of Unearthing: Sánchez Dragó's Muertes Paralelas (2006) and Andrés Trapiello's Ayer no más (2012)

This article analyzes the novels Muertes paralelas and Ayer no más as representatives of two clearly defined perspectives within the Spanish twenty-first century narrative production on unearthing the past of Francoism. The symbolic construction of unearthing permits an investigation of the remnants of a neo-Francoist vision of the legacy of the civil war, while opening the view of a political feeling by which personal memory inserts itself most profoundly as a commitment to a more comprehensive and lasting closure of the past.     

Multiphase flow simulation through porous media with explicitly resolved fractures

Accurate simulation of multiphase flow in fractured porous media remains a challenge. An important problem is the representation of the discontinuous or near discontinuous behaviour of saturation in real geological formations. In the classical continuum approach, a refined mesh is required at the interface between fracture and porous media to capture the steep gradients in saturation and saturation‐dependent transport properties. This dramatically increases the computational load when large numbers of fractures are present in the numerical model. A discontinuous finite element method is reported here to model flow in fractured porous media. The governing multiphase porous media flow equations are solved in the adaptive mesh computational fluid dynamics code IC‐FERST on unstructured meshes. The method is based on a mixed control volume – discontinuous finite element formulation. This is combined with the P_N+1DG‐P_NDG element pair, which has discontinuous (order N+1) representation for velocity and discontinuous (order N) representation for pressure. A number of test cases are used to evaluate the method's ability to model fracture flow. The first is used to verify the performance of the element pair on structured and unstructured meshes of different resolution. Multiphase flow is then modelled in a range of idealised and simple fracture patterns. Solutions with sharp saturation fronts and computational economy in terms of mesh size are illustrated.     

Food for all: An agent-based model to explore the emergence and implications of cooperation for food storage

Abstract

A consistent access to food is paramount for humans at individual and group level. Besides providing the basic nutritional needs, access to food defines social structures and has stimulated innovation in food procurement, processing and storage. We focus on the social aspects of food storage, namely the role of cooperation for the emergence and maintenance of common stocks. Cooperative food stocks are examined here as a type of common-pool resource, where appropriators must cooperate to avoid shortage (i.e. the tragedy of commons). ‘Food for all’ is an agent-based model in which agents face the social dilemma of whether or not to store in a cooperative stock, adapting their strategies through a simple reinforcement learning mechanism. The model provides insights on the evolution of cooperation in terms of storage efficiency and considering the presence of social norms that regulate reciprocity. For cooperative food storage to emerge and be maintained, a significant dependency on the stored food and some degree of external pressure are needed. In fact, cooperative food storage emerges as the best performing strategy when facing environmental stress. Likewise, an intermediate control over reciprocity favours cooperation for food storage, suggesting that concepts of closed reciprocity are precursors to cooperative stocks, while excess control over reciprocity is detrimental for such institution.     

History manifested: making sense of unprecedented change

An essential element usually passes unnoticed in recent discussion about how history as an academic discipline is supposed to be relevant for the shaping of our public life. It is the concept of history itself (history as both the course of events and historical writing) that underlies the whole discussion, which also configures the two currently most influential and fashionable efforts to reinstate the public relevance of history: The History Manifesto, co-authored by Jo Guldi and David Armitage, and Hayden White's The Practical Past. In advising to turn to the past in order to shape the present and the future, both books rely on the familiar developmental view that characterised nineteenth-century thinking in general, and on which the discipline of history became institutionalised in particular. The author's main contention in this essay is that turning to this notion of history is not the solution for the problem of the supposed public irrelevance of professional historical studies, but the problem itself. The developmental view, based on a presumption of a deeper continuity provided by the subject of the historical process that retains its self-identity amid all changes, certainly suited the discipline of history when it was engaged in the project of nation-building. However, it hardly fits our present concerns. These concerns, like the Anthropocene, take the shape of unprecedented change, and what they challenge is precisely the deeper continuity of the developmental view. The discipline of history can regain public relevance only insofar as it proves to be able to exhibit a thinking of its own specificity which can nevertheless explain such unprecedented changes. What such historical thinking could provide is what the developmental view can no longer: the possibility to act upon a story that we can believe.