The quest for companions to post-common envelope binaries: I. Searching a sample of stars from the CSS and SDSS

As part of an ongoing collaboration between student groups at high schools and professional astronomers, we have searched for the presence of circum-binary planets in a bona-fide unbiased sample of twelve post-common envelope binaries (PCEBs) from the Catalina Sky Survey (CSS) and the Sloan Digital Sky Survey (SDSS). Although the present ephemerides are significantly more accurate than previous ones, we find no clear evidence for orbital period variations between 2005 and 2011 or during the 2011 observing season. The sparse long-term coverage still permits O-C variations with a period of years and an amplitude of tens of seconds, as found in other systems. Our observations provide the basis for future inferences about the frequency with which planet-sized or brown-dwarf companions have either formed in these evolved systems or survived the common envelope (CE) phase.Comment: accepted by A&

The effects of different opacifiers on the translucency of experimental dental composite resins

OBJECTIVE: The aim of this study was to evaluate the effects of different opacifiers on the translucency of experimental dental composite-resins. METHODS: Three metal oxides that are used as opacifiers were tested in this study: titanium oxide (TiO2), aluminium oxide (Al2O3) and zirconium oxide (ZrO2). Experimental composite-resins were fabricated containing 25wt.% urethane dimethacrylate (UDMA)-based resin matrix and 75% total filler including different concentrations of metal oxides (0, 0.25, 0.5, 0.75 and 1wt.%) blended into silane treated barium-silicate filler. The specimens (15.5mm diameter and 1mm thickness) were light-cured and tested in the transmittance mode using a UV/VIS spectrophotometer at wavelengths from 380 to 700nm under a standard illuminant D65. The color differences (ΔE* ab) between different concentrations of opacifiers were also measured in transmittance mode based on their Lab values. RESULTS: Statistical analysis by ANOVA and Tukey's test showed a significant decrease (p<0.05) in light transmittance with the addition of opacifiers to the experimental composite-resins. There was a linear correlation between different concentrations of TiO2 and Al2O3 and total transmittance. Total transmittance was also found to be wavelength dependent. The color differences for the concentrations of 0-1wt.% of the opacifiers were above 1 ΔE* unit, with Al2O3 showing the smallest color shift. SIGNIFICANCE: The type and the amount of the opacifiers used in this study had a significant effect on the translucency of the experimental UDMA-based dental composite resins. The most effective opacifier was TiO2, followed by ZrO2 and Al2O3 in decreasing order, respectively

Targeting optimization of existing marketing strategies a third division handballclub : using the example of SG Leutershausen Handball GmbH

Diese Bachelorarbeit beschäftigt sich mit der zielführenden Optimierung der vorhandenen Vermarktungsstrategien eines Handball-Drittligisten. Sie beleuchtet dabei einerseits den Vermarktungsbereich durch die Sponsoren und andererseits den Vermarktungsbereich mit den Medien am Beispiel der SG Leutershausen Handball GmbH. Dabei wird zu Beginn der Gesamtverein vorgestellt, bevor die IST-Situation der Gesellschaft mt beschränkter Haftung der 1.Herrenmannschaft genauer erläutert wird. Danach werden die Experteninterviews eingebaut, um die Thematik und Problematik explizit zu untersuchen, bevor es abschließend zum Vergleich der zuvor aufgestellten Hypothesen und den Handlungsempfehlungen kommt. Ziel dieser Bachelorarbeit ist es, die Vermarktung des Vereins hinsichtlich der wirtschaftlichen, aber auch der daraus resultierenden sportlichen Wettkampffähigkeit zu untersuchen und zu verbessern