ON THE RELATION BETWEEN USERS' BENEFITS AND THE ECONOMIC EFFECTS OF TRANSPORTATION ACTIVITIES

ABSTRACT. The addition of output variation benefits to the users' surplus generated by transportation improvements has been subject to debate, and no agreement has been reached. In this paper, the problem is restated at the level of the origins of transportation demand, which can be derived from the information provided by the economic activity. It is shown that a competitive productive environment makes the transportation consumers' surplus exactly equal to the net economic benefits provoked in the products' markets; however, when monopolistic production prevails, the users' surplus may not reflect the benefits to the economy with accuracy. Mixed conditions are also explored and the role of final products' demand elasticity is highlighted. Different styles of welfare analysis are recommended for different market conditions.     

EVALUATION OF THE MANGANESE ESR METHOD OF MARBLE CHARACTERIZATION

Results suggest that ESR studies of Mn⁺² in marble can provide an excellent discriminator for the determination of marble provenance. In comparison with other methods of quantitative analysis for manganese such as AA or NAA, the ESR method determines only Mn⁺² rather than total Mn, is inexpensive and rapid with no chemical preparation required, and does not consume the sample.     

PROVENIENCE STUDY OF MEDIEVAL BULGARIAN GLASSES BY NAA AND CLUSTER ANALYSIS

The neutron activation analysis results from 30 glass samples were subjected to cluster analysis. The reliable localization of part of the medieval glass finds from Preslav enabled the evaluation of the variety of the production of a medieval glass workshop (ninth-tenth century), allowing conclusions to be made about the technological level of glass-making in Bulgaria during the Middle Ages. The work proved that NAA followed by cluster analysis is a successful approach to finding the local and chronological features of the investigated glasses.