45 research outputs found
Synthesis and Characterization of Hybrid Materials Consisting of n-octadecyltriethoxysilane by Using n-Hexadecylamine as Surfactant and Q0 and T0 Cross-Linkers
Novel hybrid xerogel materials were synthesized by a sol-gel procedure. n-octadecyltriethoxysilane was co-condensed with and without different cross-linkers using Q0 and T0 mono-functionalized organosilanes in the presence of n-hexadecylamine with different hydroxyl silica functional groups at the surface. These polymer networks have shown new properties, for example, a high degree of cross-linking and hydrolysis. Two different synthesis steps were carried out: simple self-assembly followed by sol-gel transition and precipitation of homogenous sols. Due to the lack of solubility of these materials, the compositions of the new materials were determined by infrared spectroscopy, 13C and 29Si CP/MAS NMR spectroscopy and scanning electron microscopy
Investigating the dependence of the temperature of high-intensity discharge (HID) lamp electrodes on the operating frequency by pyrometric measurements
Vacuum arc cathode spot parameters from highâresolution luminosity measurements
Cathode spots on arcâcleaned copper and molybdenum electrodes in vacuum were studied by fast image converter framing and streak camera photography with high temporal and spatial resolution. The frame exposure time was 20 ns and the interframe period was 200 ns; the streak sweep time was between 200 ns and 1 ÎŒs. Spatial structures with a resolution of 5 ÎŒm could be determined by observing the spot movement with a small slit at the streak camera and a high sweep speed. Strong fluctuations of the light emission of the spot were found with characteristic times of 50â100 ns. When the spot moved out of the slit field of view a stepwise decrease occurred in the measured light, indicating an internal substructure of the spot with distances between fragments less than 10 ÎŒm and even smaller fragment diameters. The current per fragment was estimated to be 20â40 A. The frames confirm the short time constants of the spot. From frame to frame a spot motion was observed in most cases, yielding spot residence times <200 ns
Grundlagenuntersuchungen der Eigenschaften thermisch emittierender Kathoden fuer Plasmalampen. Teilvorhaben: Existenzbedingungen nichtstationaerer Stromansaetze in Lichtboegen Abschlussbericht
SIGLEAvailable from TIB Hannover: F00B1067+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman
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Verbundprojekt: Grundlegende Charakterisierung von Elektroden fĂŒr zeitverĂ€nderliche Energieeinkopplung in umweltfreundliche Hochdruck-Plasmalampen, Teilvorhaben : Charakterisierung der Ăbergangsbereiche zwischen Plasma und Elektroden in HID-Lampen : Schlussbericht
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