The article offers a new product based theory of economic cycles. The theory explains economic activity fluctuations from the point of life-cycle of marketable goods and services. Based on our assumptions, we have created a model of world GDP and described its dynamics for the period from 1960 till 2015. In this article, we consider long-term growth trend as granted and as an independent variable due to the complexity of factors, which influence economic growth, while defining economic cycles as a recurrent process, which is analyzed by the model. Considering that, we used Hodrick-Prescott filter as an approximated function to the trend component and Fast Fourier Transform (FFT) as the method of spectral analysis of the cyclical component after detrending. We have also discovered main features of economic cycles in developed and developing countries along with the dependency of economic cycles’ amplitudes on the level of financial sector development.

The isochoric heat conductivity in plastic phases I and II solid cyclopentane(C5H10) is investigated. Various temperature dependents of heat conductivity indicate various characteristics of a rotary motion of molecules in these phases. In phase II, the motion of the molecules has mainly character of libration, and in phase I, is close to the hindered rotation. In a phase I of cyclopentane an increase in the slope of isochoric heat conductivity with the growth of the density of samples is revealed. Such behavior of heat conductivity is not characteristic of molecular crystals and can point to a contribution of “pseudorotation” to heat transfer. In phase II, cyclopentane the behavior of heat conductivity is close to a case of strong scattering of phonons.