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When measuring Q and the flexural resonance frequency of bars clamped at one end, constituted by a viscoelastic polymeric material glued to a rigid support of modulus E, it is possible to calculate the components E and E of the complex elastic modulus of the polymeric material examined. In this work the minimum (critical) value of the ratio a′=E/ E= a and the values of the ratio Q/ Q= F are evaluated beyond which no exact calculation of E and of Q is possible. Within the confidence limits of the linear viscoelasticity theory, these values depend on the accuracy of measurement of both frequency and resonance curve, as well as on the instrument employed, on the operating temperature and on the ratio between the thicknesses of the two coupled materials. In order to keep outside the critical conditions, the most convenient method involves the use of measurements of coupled test-pieces having different ratios z between their thicknesses and of supports having different modulus E, depending on the field of temperature of the analysis of E and tg γ concerning and E.P.R. elastomer and a vulcanized cis-1,4 polyisoprene in very wide ranges of temperature comprising the glass transition. Moreover, it is demonstrated by analysis the shift on the temperature axis of the tg γ maximum of the composite test-piece with respect to the position of the tg γ maximum of the polymeric material alone. [ABSTRACT FROM AUTHOR]

This article reports on some of the methodological problems encountered in the present work to compare the national income, and its components, of the planned economies of Eastern Europe within the framework of the Council for Mutual Economic Assistance (CMEA) as of June 1966. The chief aim of the study is to compare the national income of these countries. Starting from the expenditure side of the national income the comparison covers two basic aggregates: consumption, and accumulation. Industrial and agricultural production, that is, the two most important branches of production, are also compared, in some degree independently of the comparison of national income, but in essence by means of similar methods using several types of indicators. The results of these large scale computations based on a great quantity of data permit a many-sided comparative analysis of the countries. The main task is, of course, to determine the proportions of the aggregates studied and of the physical volumes of the components of the aggregates in the countries, i.e., to construct inter-regional indices of volume. In addition, the results obtained make it possible to show the most important characteristics of the production and consumption patterns of the countries. The comparison gives highly valuable information on the real purchasing power of the currencies.