THE GENUS HYPOGLOSSUM KÜTZING (DELESSERIACEAE, RHODOPHYTA) IN THE TROPICAL WESTERN ATLANTIC, INCLUDING H. ANOMALUM SP. NOV. 1

Observations are made on the occurrence and distribution of the red algal genus Hypoglossum KÜtzing (Delesseriaceae, Ceramiales) in the tropical western Atlantic. In addition to the type of the genus, H. hypoglossoides (Stackh.) Coll. & Herv., three other species are reported: H. anomalum sp. nov., H. involvens (Harv.) J. Ag., and H. tenuifolium (Harv.) J. Ag. A key is presented to distinguish these four species. The newly described species, H. anomalum, is like other species in the genus in that its branches arise endogenously from the primary axial row but it is unique in that the branches emerge from the parent blade at some point between the midline and the margin of the blade. The new species is reported from Puerto Rico and Florida.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65648/1/j.1529-8817.1986.tb04162.x.pd

Measurements of a low temperature mechanical dissipation peak in a single layer of Ta2O5 doped with TiO2

Thermal noise arising from mechanical dissipation in oxide coatings is a major limitation to many precision measurement systems, including optical frequency standards, high resolution optical spectroscopy and interferometric gravity wave detectors. Presented here are measurements of dissipation as a function of temperature between 7 K and 290 K in ion-beam sputtered Ta2O5 doped with TiO2, showing a loss peak at 20 K. Analysis of the peak provides the first evidence of the source of dissipation in doped Ta2O5 coatings, leading to possibilities for the reduction of thermal noise effects

Friction reduction and zero wear for 52100 bearing steel by high‐dose implantation of carbon

Ion implantation of carbon in the AISI 52100 bearing steel yields a distinct reduction in friction and wear. This improvement is strongly dependent on the implanted fluence. The coefficient of friction decreases from 0.6 to 0.2 for doses >1×1018 cm-2 (energy 100 keV) and a wear reduction to nearly ‘‘zero wear’’ was obtainable even under severe wear conditions. The counterpart (unimplanted AISI 52100 steel ball) shows a similar behavior, which demonstrates that the tribological system is totally changed. Mössbauer spectroscopy and x-ray diffraction revealed that hexagonal ¿-carbide is formed on implantation. On the other hand, Rutherford backscattering spectrometry shows that for high doses a large fraction of the implanted carbon is not contained in this carbide