The mechanical properties of macrolithic artifacts: a methodological background for functional analysis

Natural, technical and social factors led to the use of a wide range of rocks for the production of macrolithic artifacts during the later prehistory. In the case of some artifact types, such as the grinding stones, rocks with very different petrographic qualities appear. Analysis of the material behavior, as developed by material sciences, provides a tool which allows the translation of these petrographic characteristics into mechanical properties. Experiments with a group of rocks subjected to different forms of abrasion in industrial machines allow an evaluation of the adjustment between the mechanical properties of the rock and the functions for which they were chosen by prehistoric societies. Finally, the understanding of the mechanical properties of the raw materials together with their forms of exploitation, distribution and use allows the designation of social and economic meaning to the production systems linked to the macrolithic tools.     

Physics-Based Simulation Model of Post-Earthquake Fire Spread

This article describes a new model that simulates the spread of post-earthquake urban fires. Adapting and integrating compartment fire models, this new model explicitly represents: (1) the evolution of fire within a room or roof; (2) room-to-room spread within a building through doorways, by burning through walls and ceilings, and by leapfrogging between windows; and (3) building-to-building spread by window flame impingement; radiation from window flames, room gas, and roof flames; and branding. The model can be used to explore how much, how fast, where, and by what modes fires will spread, and what factors influence fire spread.     

Application of a Physics-Based Simulation Model to Examine Post-Earthquake Fire Spread

For 50 years, post-earthquake fire spread models used the basic empirical, macro approach developed by Hamada in 1951 Hamada, M. 1951. On Fire Spreading Velocity in Disasters, Tokyo: Sagami Shobo. (in Japanese) [Google Scholar]. Recently, however, a few physics-based models have emerged in which different modes of fire spread (e.g., radiation, branding) are modeled separately, more realistically, and in more detail. Using a case study for Los Angeles, this article illustrates how a new physics-based model developed by the authors can be used to estimate how much, how fast, and where fires spread, and also to provide insight into how fires spread and factors that influence fire spread.