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Influence of wavelength-shifting films on multianode PMTs with UV-extended windows
Adamczewski-Musch, J.,Becker, K.-H.,Belogurov, S.,Boldyreva, N.,Chernogorov, A.,Deveaux, C.,Dobyrn, V.,Dü,rr, M.,Eom, J.,Eschke, J.,Hö,hne, C.,Kampert, K.-H.,Kleipa, V.,Kochenda, L.,Kolb, B.,K Elsevier 2015 Nuclear Instruments & Methods in Physics Research. Vol.783 No.-
<P><B>Abstract</B></P> <P>Wavelength-shifting (WLS) films were applied on UV-extended front windows of multianode photomultiplier tubes (MAPMTs) in order to increase the sensitivity of the MAPMTs at shorter wavelengths. The WLS material contained p-Terphenyl as photoactive component, which absorbs shorter wavelength photons ( < 300 nm ) and re-emits fluorescence photons around 350nm, i.e., at the maximum of the PMTs׳ sensitivity. The films were applied by means of dip-coating and the film performance was studied with respect to quantum efficiency, film homogeneity, and crosstalk on the MAPMTs. Using WLS-film-covered MAPMTs in a gaseous Ring Imaging Cherenkov detector, the number of detected photoelectrons per ring increased by up to 21% in an in-beam test.</P>
C. Rollbuhler,L. Stefanski,S. Gretzinger,J. Kolb,M. Hiller,M. Doppelbauer 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5
Current distortion of two-level converter-fed permanent magnet synchronous machines causes additional machine-side losses, which lead to a distinct reduction in the drive train efficiency of electric vehicles for instance. Determining these losses by measurement is still an ambitious task. On the one hand, there’s a lack of adequate voltage sources. On the other hand, there is no accurate procedure to distinguish between the different loss components. In this publication, a 100 kVA seven-level multilevel converter is used to determine the losses of a 60 kW highly-utilized permanent magnet synchronous machine for automotive use. Due to the good voltage quality of the multilevel converter, the machine currents have very low harmonic distortion and the determined losses are considered as fundamental ones. In a second experiment, the machine is operated with a conventional two-level converter. Comparing machine losses in both experiments allows the determination of the additional machine losses in two-level operation.
SUNSHINE, EARTHSHINE AND CLIMATE CHANGE: II. SOLAR ORIGINS OF VARIATIONS IN THE EARTH'S ALBEDO
GOODE P. R.,PALLE E.,YURCHYSHYN V.,QIU J.,HICKEY J.,RODRIGUEZ P. MONTANES,CHU M.-C.,KOLBE E.,BROWN C.T.,KOONIN S.E. The Korean Astronomical Society 2003 Journal of The Korean Astronomical Society Vol.36 No.suppl1
There are terrestrial signatures of the solar activity cycle in ice core data (Ram & Stoltz 1999), but the variations in the sun's irradiance over the cycle seem too small to account for the signature (Lean 1997; Goode & Dziembowski 2003). Thus, one would expect that the signature must arise from an indirect effect(s) of solar activity. Such an indirect effect would be expected to manifest itself in the earth's reflectance. Further, the earth's climate depends directly on the albedo. Continuous observations of the earthshine have been carried out from Big Bear Solar Observatory since December 1998, with some more sporadic measurements made during the years 1994 and 1995. We have determined the annual albedos both from our observations and from simulations utilizing the Earth Radiation Budget Experiment (ERBE) scene model and various datasets for the cloud cover, as well as snow and ice cover. With these, we look for inter-annual and longer-term changes in the earth's total reflectance, or Bond albedo. We find that both our observations and simulations indicate that the albedo was significantly higher during 1994-1995 (activity minimum) than for the more recent period covering 1999-2001 (activity maximum). However, the sizes of the changes seem somewhat discrepant. Possible indirect solar influences on the earth's Bond albedo are discussed to emphasize that our earthshine data are already sufficiently precise to detect, if they occur, any meaningful changes in the earth's reflectance. Still greater precision will occur as we expand our single site observations to a global network.