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This paper is an introduction to the problems of dumping at sea of radioactive wastes. A short survey is given on the dumping actions previously performed, the legal justification by international treaties, and the most important radioecological questions. [ABSTRACT FROM AUTHOR]

The direct conversion of solar energy to electrical energy (photovoltaic effect) by solar cells is receiving increasing attention on a world-wide scale. Photovoltaic energy conversion offers itself to a practical and meaningful implementation in regions without a conventional energy grid. This paper deals with the principles of silicon solar cells for terrestrial applications and new methods for the production of the necessary silicon. [ABSTRACT FROM AUTHOR]

A short historic introduction into the subject and the basics of the generation of a photoacoustic signal with the emphasis upon the particularities of solid samples are given. The set-up of a two-beam photoacoustic spectrometer is described. For a better understanding of the investigations of solid samples the basic theory is presented. Specially treated subjects are: the saturation effect and how to overcome it; depth profiles of thin layers as a nondestructive method used in the investigation of a green leaf and a sheet of color reversal paper; the investigation of solid solutions in a polymer matrix with the determination of the thermic data of the matrix itself, and the fluorescence quantum yield of organic dyes solved therein. Finally a summary of numerous other applications of the PAS is given. [ABSTRACT FROM AUTHOR]

The paper gives a short review of biochemical and genetic analyses of the eukaryotic cell cycle and cell division. Emphasis is placed on the interrelationship of macromolecular syntheses during chromosome replication, the possible involvement of protein phosphorylation in chromosome condensation, the function of contractile proteins in mitosis and cytokinesis and on mechanisms which trigger cell proliferation. [ABSTRACT FROM AUTHOR]

Alfred Wegener's most important work, the theory of continental drift, has a key position in the history of geophysics and has crucially advanced the discussion of this central problem of geodynamics amongst supporters and adversaries. The aim of this paper is to paint a portrait of Wegener's personality, of his stations of life, and of his interests and research work. The conceptions of the origin of continents and oceans prior to Wegener, and the further development of his ideas after his death on the ice cup of Greenland 50 years ago are discussed. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to give an idea of modern mathematics and of its contribution to science as a whole. As an example to illustrate this the theory of fixed points of continuous mappings has been chosen, because it allows to explain recent mathematical achievements to non-mathematicians without lengthy preparations and because it has several applications. We shall sketch such applications in biology, numerical computation, economics and hydrodynamics. [ABSTRACT FROM AUTHOR]

The preservation of historical works of artistic and cultural significance that are made of paper, wood, textiles, ivory, amber, and similar organic materials is difficult because of their rapid deterioration due to the action of light, humidity, temperature variation, or attack by fungi and insects. Based on the application of synthetic products, new techniques for the preservation of these materials have been developed in the last few years, which contribute to permanent protection. [ABSTRACT FROM AUTHOR]

This paper deals with the history of exoelectron emission (EE), as well as with the experimental results and the attempts to explain them. The author concludes that thermally and optically stimulated EE (TSEE, OSEE) are different phenomena and that OSEE is mere photoeffect. The source of the energy causing the emission has been heatedly discussed. The author believes that most of the models can be ruled out by the fact that the activation energies do not depend on the nature of the metal nor on its oxide. He supposes the simplest model-direct thermal emission from surface traps-to be right. The author concludes that none of the excitation processes produces electron traps, as is often assumed. They only fill existing traps with electrons, e.g., radiation, mechanical treatment or a simple dip in water. [ABSTRACT FROM AUTHOR]

Following an article on the charm model (Naturwissenschaften 64, 229 (1977)) and its predictions, the present paper reviews the current status of its experimental verification. Four out of six predicted mesons with charm have been detected by their nonleptonic decay. The semileptonic decay of charmed mesons has also been established proving the predicted weak nature of the decay. In addition, there are strong indications as to the existence of charmed baryons from a photoproduction experiment corroborating clues given earlier by neutrino experiments. [ABSTRACT FROM AUTHOR]

Because of the sudden rise in primary-energy costs and the rapid inflation of plants which are used for the conversion of primary to secondary energy, the storage of energy, as well as the avoidance of energy losses, has assumed new importance. This paper deals with the technical and economic aspects of energy storage and discusses some methods of energy transport. [ABSTRACT FROM AUTHOR]

New political, economical, and technical developments have changed the character of world fisheries. The exploitation of relatively small marine organisms, mainly pelagic fish, as a source of protein and the large distant-water fishing fleets of some countries operating worldwide make it possible to change marine ecosystems and particularly the upper parts of the food chain rapidly and drastically. The paper discusses recent changes in North Sea fish stocks and the ecological effects of antarctic whaling. [ABSTRACT FROM AUTHOR]

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The physical and chemical properties of polycyclic aromatic hydrocarbons depend on the size (number of carbon centres) and the topology of the systems. Consequently structure/property relations can be treated as quantitative analogy models with size and topology as the independent variables. This class of compounds is the example par excellence to put forward a general view in chemistry, i.e. topological chemistry. [ABSTRACT FROM AUTHOR]