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We have analyzed time-series data for 160 stars in the old open cluster M67. Approximately 400 CCD frames from two nights on the Burrell Schmidt have been reduced differentially relative to an ensemble of seventeen stable stars. We present data on two new variables and evidence of four new suspected variable stars in M67.
The presence or absence of dwarf galaxies with Mr' > -14 in low-density volumes correlates with dark matter halos and how they affect galaxy formation. We are conducting a redshifted Hα imaging survey for dwarf galaxies with Mr' > -13 in the heart of the well-defined voids FN2 and FN8 using the KPNO 4m Mayall telescope and Mosaic Imager. These data have furnished over 600 strong candidates in a four square degree area. Follow-up spectra finding none of these candidates to be within the void volumes will constrain the dwarf population there to be 2 to 8% of the cosmic mean. Conversely, finding even one Hα dwarf in the void heart will challenge several otherwise successful theories of large-scale structure formation.
Advanced materials are being designed and tested for high-stress, high-cycle ball bearing applications. Important information about the tribological performance of these materials is gained through rolling contact fatigue (RCF) measurements. No such data have been reported to date for hybrid bearings consisting of titanium carbide (TiC)-coated REX20 steel balls and REX20 steel raceways. Chemical vapor deposition (CVD) was used for depositing the TiC coating. In this paper, we present the first report of the effects of RCF tests on this particular combination of hybrid bearings. Post-test characterizations of these bearings are discussed. Our investigations include plan-view and cross-sectional scanning electron microscopy, chemical compositional analyses, X-ray diffraction, and nano-indentation measurements. Results of these investigations provide a detailed understanding of the TiC coating on REX20 steel balls following extended rolling contact.
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