Obsidian hydration dating by infrared spectroscopy: method and calibration

Low temperature (90–190 °C) hydrothermal experiments have been conducted on seven obsidians where composition of the glass varies significantly in the concentration of structural water within the unhydrated bulk material. Infrared transmission spectroscopy was used to track the diffusion of molecular water into the glass surface as a function of time and temperature. Long-term (60–360 days) hydration sequences at 90 °C show a t^0.6 time dependence for the mass uptake of molecular water that forms the hydration layer. The structural water concentration of the unhydrated bulk obsidian is highly correlated with the pre-exponential and activation energy and may be used to estimate the Arrhenius constants. In addition, secondary ion mass spectrometry (SIMS) hydrogen profiling of Napa Glass Mountain obsidian hydrated at 90 °C reveals that the early stages of diffusion exhibit a dynamic behavior that includes a fluctuating hydrogen concentration and a changing diffusion coefficient that slows with time.     

Legal realism and human rights

This essay uses Schmitt's work to cast new light on the relevance of the American legal tradition known as ‘legal realism’ for the history and analysis of human rights. It does so by exploring several of Schmitt's most famous criticisms of international law and human rights, and then suggests how they might correspond with a widespread critical legal tradition in the 1920s and 1930s. This essay describes in detail two fundamental features of this tradition: historicism and realism. It concludes by suggesting that a return to some of these earlier law writers and texts might be a more substantive way to develop a constructive critical position in the fields of human rights and international law than an overreliance on the politically provocative (and problematic) rhetorical flourishes of Carl Schmitt.     

Prehistoric settlement chronology on Rapa Nui,Chile: obsidian hydration dating using infrared photoacoustic spectroscopy

The prehistoric Polynesian inhabitants of Rapa Nui (Easter Island) utilized obsidian for nearly 700 years in many activities connected with daily life. The near ubiquitous occurrence of the natural glass in both domestic residences and religious structures makes the application of obsidian hydration dating highly suitable for the investigation of cultural change. We have applied previously developed calibrations that estimate hydration rates for obsidian based upon the structural water content of the glass as determined by infrared spectroscopy. The archaeological ages estimated by this method were compared with accelerator mass spectrometry (AMS) dates using short-lived woody species endemic to the island. The convergence between the two dating methods is strong and we suggest that obsidian hydration dating may be used on Rapa Nui to reliably date contexts where suitable material for AMS dating may not be available.     

The view beyond downtown luxury towers: Diversity of condominium developments in a contemporary mid-sized city

A proliferation of condominiums is fundamentally changing the built, social, and economic fabric of Canada's cities. While developments may be found throughout the urban landscape of cities large and small, most of the contemporary research focuses on luxury towers in the urban cores of Toronto and Vancouver. The following study examines the complete inventory of all condominium units in Halifax, Nova Scotia, revealing spatial and temporal patterns in their development. Nearly 60% of Halifax's condominium units are found in the suburbs, with only 20% in the downtown. Condominium units built since 2010 command the highest prices, surpassing the median single detached house price in the city, while older units from the 1970s and 1980s remain largely affordable. Recent developments can be found in gentrifying neighbourhoods; however, they remain a minority as many more units are found in middle-class suburbs and wealthy inner-city neighbourhoods. Owing to their varied manifestations, the predominant associations of condominiums with a downtown, luxury housing format needs expanding to include locations throughout the metropolitan area, distinct building types, and wide range of prices.     

Legal realism and human rights

This essay uses Schmitt's work to cast new light on the relevance of the American legal tradition known as ‘legal realism’ for the history and analysis of human rights. It does so by exploring several of Schmitt's most famous criticisms of international law and human rights, and then suggests how they might correspond with a widespread critical legal tradition in the 1920s and 1930s. This essay describes in detail two fundamental features of this tradition: historicism and realism. It concludes by suggesting that a return to some of these earlier law writers and texts might be a more substantive way to develop a constructive critical position in the fields of human rights and international law than an overreliance on the politically provocative (and problematic) rhetorical flourishes of Carl Schmitt.