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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]

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]

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]

A survey is given of properties, formation, and application of muonic atoms in physics, chemistry, and archeometry. In the field of physics the measurement of nuclear charge distributions and vacuum polarization as well as the slowing down of muons in matter are treated in some detail, and in the fields of chemistry and archeometry, non-destructive quantitative chemical analysis of bulk material and, with the help of suitable beam setting, also of selected parts of the specimen. [ABSTRACT FROM AUTHOR]

Types of asbestos are distinguished not only by structure, chemical compositon, shape of aggregates, and length and quality of fibers, but also by its formation. Though consisting of quite common elements, deposits are formed only under very special conditions. Its unique combination of properties has created over 3000 fields of application (about 70% in asbestos cement). Great efforts have been made to substitute all types of asbestos by harmless, similarly cheap and versatile synthetic fibers, owing to the unquestioned carcinogenic properties of all asbestos dusts. However, development of such fibers has not made any remarkable progress until recently. Consequently risk to workers in mining and manufactoring, consumers, outsiders, and the environment should be kept as low as possible by intensifying precautions and diminishing emissions. [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]