TRADITIONAL ECONOMIES AND SOCIAL PROTEST IN WEST GERMANY AND ITALY IN 1966-1974

Every crisis of the world capitalist economy prompts a new wave of interest in long economic cycles. In the second half of the 20 century, the emergence of new social movements and activity of «traditional» working class can be analyzed as important barometers of socio-economic development in transitional economies of European countries towards postindustrial society. In this article the author employs a theory of the dynamics of protest waves developed by Ruud Koopmans to analyse social processes in West Germany and Italy between 1966 and 1974. Special attention is given to study of different types of social protest movements: spontaneous, semi-military groups and those affiliated with political parties. A special emphasis is put on showing how the protest wave started with confrontational actions, subsequently entered a phase of moderate mass mobilization, and ended up with a twin process of institutionalization and radicalization

Bosonic Excitations in Random Media

We consider classical normal modes and non-interacting bosonic excitations in disordered systems. We emphasise generic aspects of such problems and parallels with disordered, non-interacting systems of fermions, and discuss in particular the relevance for bosonic excitations of symmetry classes known in the fermionic context. We also stress important differences between bosonic and fermionic problems. One of these follows from the fact that ground state stability of a system requires all bosonic excitation energy levels to be positive, while stability in systems of non-interacting fermions is ensured by the exclusion principle, whatever the single-particle energies. As a consequence, simple models of uncorrelated disorder are less useful for bosonic systems than for fermionic ones, and it is generally important to study the excitation spectrum in conjunction with the problem of constructing a disorder-dependent ground state: we show how a mapping to an operator with chiral symmetry provides a useful tool for doing this. A second difference involves the distinction for bosonic systems between excitations which are Goldstone modes and those which are not. In the case of Goldstone modes we review established results illustrating the fact that disorder decouples from excitations in the low frequency limit, above a critical dimension $d_c$, which in different circumstances takes the values $d_c=2$ and $d_c=0$. For bosonic excitations which are not Goldstone modes, we argue that an excitation density varying with frequency as $\rho(\omega) \propto \omega^4$ is a universal feature in systems with ground states that depend on the disorder realisation. We illustrate our conclusions with extensive analytical and some numerical calculations for a variety of models in one dimension

Pairing and Density Correlations of Stripe Electrons in a Two-Dimensional Antiferromagnet

We study a one-dimensional electron liquid embedded in a 2D antiferromagnetic insulator, and coupled to it via a weak antiferromagnetic spin exchange interaction. We argue that this model may qualitatively capture the physics of a single charge stripe in the cuprates on length- and time scales shorter than those set by its fluctuation dynamics. Using a local mean-field approach we identify the low-energy effective theory that describes the electronic spin sector of the stripe as that of a sine-Gordon model. We determine its phases via a perturbative renormalization group analysis. For realistic values of the model parameters we obtain a phase characterized by enhanced spin density and composite charge density wave correlations, coexisting with subleading triplet and composite singlet pairing correlations. This result is shown to be independent of the spatial orientation of the stripe on the square lattice. Slow transverse fluctuations of the stripes tend to suppress the density correlations, thus promoting the pairing instabilities. The largest amplitudes for the composite instabilities appear when the stripe forms an antiphase domain wall in the antiferromagnet. For twisted spin alignments the amplitudes decrease and leave room for a new type of composite pairing correlation, breaking parity but preserving time reversal symmetry.Comment: Revtex, 28 pages incl. 5 figure

Determination of the distorted surface layer thickness in machined optically transparent polymer articles

The functional performance of the optical polymer articles and the service life thereof are defined to a considerable extent by the surface layer state. When machined, the surface layer of polymer articles differs in its properties from the initial material. The combined force and heat action during the cutting results in a complex final structure state of the surface layer. This fact requires investigations to determine the changed (distorted) layer depth after the machining and to study its influence on the functional properties of the optical polymer articles.Функциональные свойства и долговечность работы изделий из оптических полимеров в значительной степени определяются состоянием их поверхностного слоя. При механической обработке поверхностный слой полимерных изделий приобретает свойства, отличные от свойств исходного материала. Взаимное проявление силового и теплового факторов в процессе резания приводит к сложному итоговому структурному состоянию поверхностного слоя изделия. Это требует проведения обстоятельных исследований для выявления глубины измененного (нарушенного) слоя после механической обработки и изучения его влияния на эксплуатационные свойства оптических полимерных изделий.Функціональні властивості і довговічність роботи виро6ів з оптичних полімерів в значній мірі визначаються станом їхнього поверхневого шару. При механічній обробці поверхневий шар полімерних виробів здобуває властивості, відмінні від властивостей вихідного матеріалу. Взаємний прояв силового і теплового факторів у процесі різання приводить до складного підсумкового структурного стану поверхневого шару виробу. Це вимагає проведення докладних досліджень для виявлення глибини зміненого (порушеного) шару після механічної обробки і вивчення його впливу на експлуатаційні властивості оптичних полімерних виробів