Browsing by Author "Kreidl, Norbert J."

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    Glass in a decade of light
    (Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1987) Kreidl, John F.; Kreidl, Norbert J.
    Accelerated research and development is expected to increase significantly the integral role of hght in opto-electronic devices. Telecommunication may serve for longer repeater distances ( > 1000 km) to be achieved by the development of both lower-loss glasses and device sophistication. Heavy cation fluoride glasses are important candidate materials because of potentially low scattering losses, high radiation resistance and transmission in desirable IR ranges, although they still require property and process improvements. Sensors operating in the near infrared will benefit from those developments and command a large market. Digital optics, now a concept mostly of imagination, may become a reality competing with the electronics by switching speed (≪1 ps), and immunity to electrical noise.
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    Recent highlights of glass science A selective topical review Part 1. Glass formation, structure and properties of oxide and chalcogenide systems
    (Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1987) Kreidl, Norbert J.
    A concise review aiming at spreading information on advances in glass science beyond specialists in the many fields in this area. This first part covers the formation and structure of oxide and chalcogenide glasses.
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    Recent highlights of glass science A selective topical review Part 2. Silicate systems
    (Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1990) Kreidl, Norbert J.
    A concise review aiming at spreading information on advances in glass science beyond specializing in the many fields in this area. This paper is a continuation of part 1 [1] limited to the newest findings in the area of silica and simple as well as complex silicate glasses. Faced by the abundance of the current glass literature, any review admittedly will be incomplete and arbitrary. Borosilicate, aluminosilicate and fluorosilicate systems will be reviewed in later parts of this series.
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    Variability of optical properties and structure of glass
    (Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1989) Kreidl, Norbert J.
    The network theory of glass formation may be broadened by the accessory enhancing effect of some asymmetry of electronic structure to explain the glass formation of compounds containing large amounts of lead oxide. Molar refraction and its variability by cationic environment, temperature and time is used as a measure of electronic displacement. The apparent refraction of oxygen in silicates, borates and phosphates increases with decreasing field strength of cations, with increasing Ο : Si, Ο : Β and Ο : Ρ ratios and with decreasing degree of annealing. The apparent refraction of O2- thus is, for instance, 3.35 in Be2SiO4, 4.97 in Ba2SiO4. In a borosilicate crown annealing may increase density by 1 %, yet decrease refraction by 1/3 %. Generally, in the transformation range a steady, complex ordering phenomenon representable by decreasing entropy takes place which in contrast to discontinuous allotropic changes and in analogy to solid solutions of feldspars corresponds to a continuous series of possible states. In some cases this series may even lead first to denser, then to looser structures during one and the same isothermal treatment. This appears confirmed by experiments on thermal expansion, density and refractive index in different laboratories.