Beam related thermal losses on the cryogenic and vacuum systems of LEP

The LEP Collider was operated in 1997 with 60 superconducting four-cavity accelerating modules (about 2600 MV available) installed at the four interaction points. During operation for physics it was o bserved that the dissipated heat in the superconducting cavities is not only a function of the acceleration gradient but it also depends on beam characteristics: number of bunches, bunch length and cu rrent per bunch. These beam effects were not foreseen in the original heat budget of the LEP refrigerators. Three days of LEP Machine Development were dedicated in August 97 to clarifying the correlat ion of the losses with the beam characteristics. The beam dependent heat load of the cryogenic system for the superconducting cavities is described. The dependence on various beam parameters is presen ted and scaling laws are given. A possible explanation will be presented and the consequence for LEP operation will be discussed

Wirtschaft als eigenes Schulfach? Empirische Evidenz zur Facheinführung in Baden-Württemberg

Das Buch präsentiert die Ergebnisse einer Studie, die über vier Jahre die Einführung des Faches Wirtschaft/Berufs- und Studienorientierung in Baden-Württemberg begleitete. In einem Vergleich der letzten Kohorte von Lernenden ohne Fach mit den Schüler:innen, die erstmals im Fach unterrichtet wurden, werden Facheffekte untersucht und bewertet. Im Mittelpunkt stehen die Fragen, inwieweit der Unterricht zu einer Stärkung ökonomischer Kompetenz beiträgt und ob durch ihn nicht intendierte Einstellungsänderungen bewirkt werden. Außerdem werden mögliche Verhaltensänderungen und Wissenszuwächse untersucht. Die Verfasser:innen diskutieren ihre Resultate sowohl methodisch als auch vor dem Hintergrund der curricularen Änderungen und der damit einhergehenden Diskussion um das Für und Wider der Facheinführung. Ihr Fazit ist insgesamt positiv, zeigt aber auch Förderbedarfe für bestimmte Gruppen von Lernenden auf. Zusätzlich enthält der Band den kompletten und gut validierten Kompetenztest inklusive einer Kurzfassung zur Integration in weitere Studien. (DIPF/Orig.

SensoPlate™: Glass Bottom Microplates (24, 96, 384, 1536 Well) for High Performance Detection

Greiner Bio-One and Aventis Pharma have co-developed a full set of unique glass bottom microplates (24, 96, 384, 1536 well). The glass bottom plates incorporate high quality optical glass with a thickness of 175 µm bonded to the parent plastic microplate. All plates comply to the standardized microplate footprint and provide superior quality in applications where low autofluorescence and optical clarity are required. At the time, these plates are available in opaque black for high-resolution imaging, sensitive fluorescence and confocal microscopy applications, like fluorescence correlation spectroscopy (FCS) and single molecule detection. The combination of modern confocal optics, new dyes as efficient fluorescent probes, sensitive PMTs, and fast data processing made FCS suitable for real time dynamics of single molecules in femtoliter volumes, close to the size of a common bacterial cell. This method has found its way as a tool for basic research as well as for industrial applications such as drug screening. Applications like FCS and confocal microscopy require high quality glass bottom plates with superior planarity. The new SensoPlates™ have a bottom flatness of less than 70 µm. The black frame of the SensoPlate™ consists of low autofluorescence, black opaque polystyrene to minimize light reflection and scattering. The glass bottom enables high transmittance and optical clarity for wavelengths from 350 up to 1000 nm. The biocompatible and medical grade adhesive applied provides strong and tight joints in water, PBS buffer and DMSO media between -10°C and 50°C. With the advent of SensoPlate™ a full set of glass bottom microplates (24, 96, 384, 1536 wells) is now available with high planarity, high optical clarity and low autofluorescence. The plates have already demonstrated its superior performance in selected applications