ELECTRON SPIN RESONANCE STUDY OF WHITE MARBLES FROM THARROS (SARDINIA): A REAPPRAISAL OF THE TECHNIQUE,POSSIBILITIES AND LIMITATIONS*

The characterization of various samples of white marble from the archaeological site of Tharros (Sardinia) is the starting point for the reexamination of the capabilities of electron spin resonance (ESR) spectroscopy as a tool for identifying the quarries of origin of ancient marble artefacts. Existing methods and data bases are employed for the assignment of our samples, but also reviewed to see if a more extensive use of the technique is feasible. It turns out that ESR spectroscopy, coupled with other available methods, may readily provide valuable information, often yielding the final answer to the problem of marble provenance. However, it is also clear that much work has still to be done to standardize the data collection and analysis procedures and to expand the available data base.     

Forecasting Structural Change With a Regional Econometric Input-Output Model

The sophistication of regional economic models has been demonstrated in numerous ways, most recently in the form of linking several modeling systems or in the expansion in the number of equations that can be manipulated successfully to produce impact analyses or forecasts. In this paper, an alternative perspective is employed. What do regional macro-level forecasts indicate about the process of structural change? A new methodology is illustrated that enables analysts to make forecasts of detailed structural change in the interindustry relations in an economy. Using a regional econometric input-output model developed for the Chicago metropolitan region, derived input-output tables are extracted for the period 1975–2016. These tables are then analyzed to determine the forecasted direction of structural changes for the region. The innovation illustrated here is based on a model that exploits the general equilibrium spirit of computable general equilibrium models through the adjustment of input coefficients to clear markets.     

CANADA'S NATIONAL PARKS: A MODEL OF ADMINISTRATIVE PENETRATION

National parks can no longer be considered as pristine ecosystems protected by impenetrable boundaries. It is now realised that many forces outside national park boundaries create significant changes within those boundaries. To date, most attention has focussed upon penetration by biophysical factors. This paper addresses another aspect, external influence over decision making in the parks. It suggests that three main groups - entrepreneurs, environmentalists, and aboriginal peoples - have been dominant in different time periods, and uses case studies to illustrate the rise to current prominence of aboriginal peoples. Reasons are suggested for this ascendancy.
Les pares nationaux ne peuvent plus être considérés comme des écosystèmes primitifs protégés par des limites impénétrables. On remarque à présent que beaucoup de forces en dehors des limites des pares nationaux peuvent créer des changements significatifs à &lcaron intérieur de ces limites. Jusquà maintenant la plupart des études ont traité de la pénétration par des facteurs biophysiques. Cet article traite &dcaron un autre facteur, une influence externe qui agit sur les décisions prises au sujet des pares. Nous suggérons que trois groupes principaux - les entrepreneurs, les écologistes et les populations autochtones - ont été dominants à des époques différentes, et soumettrons des études de cas pour illustrer comment les populations autochtones sont arriveées à la dominance. Nous offrirons également des raisons pour cette ascension.     

ELECTRON SPIN RESONANCE THERMOMETRY APPLIED TO QUARTZITE COBBLES FROM VERGELEGEN SLAVE LODGE,SOMERSET WEST,SOUTH AFRICA

This paper describes the use of electron spin resonance spectroscopy to estimate the degree of heating of quartzite cobbles from hearths on the floor of the archaeological remains of an eighteenth-century Dutch colonial slave lodge. A novel technique based on the comparison of line intensities for the E’and O^-₂ centres in quartz distinguished successfully between cobbles which had been heated to estimated temperatures ranging from 300 °C to 450° C and controls from an adjacent stream bed. This inexpensive and simple technique could be applied to a wide range of archaeological problems involving the thermal history of objects consisting of or containing quartz.     

The Pyramids—Cement or Stone?

Several samples of pyramids from Giza were obtained. The samples were analysed by scanning electron microscopy, electron diffraction by X-rays, powder X-ray diffraction, inductively coupled plasmography, Fourier-transform infrared spectroscopy and other techniques. Some scientists who have recently studied the pyramids have suggested that the pyramids were poured into place, stone by stone. The prevailing theory among Egyptologists is, of course, that the pyramids were built from blocks of natural stone. All of the results obtained during this study directly support the concept that the pyramids are made of limestone and are not cementitious in nature.     

Net migration estimation in an extended,multiregional gravity model

A multi-regional framework is developed in order to analyze net migration over time to all 10 Canadian provinces within an integrated system of equations. "An extended gravity model is the basis for the equation specification and the use of constrained econometric estimation techniques allows for the provincial interdependence of the migration decision while at the same time ensuring that an important system-wide requirement is respected." The model is estimated using official Canadian data for the 1960s and 1970s. "The results suggest the predominance of the push factor for interprovincial migration for most provinces, although net migration to the Atlantic provinces is also shown to be subject to pull forces from the rest of the country." The effects of wage rate variables, unemployment, and political disturbances in Quebec on inter-provincial migration are noted.