Leslie Morris: The Translated Jew. German Jewish Culture outside the Margins

Leslie Morris: The Translated Jew. German Jewish Culture outside the Margins (=Cultural Expressions of World War II). Evanston, Ill.: Northwestern University Press 2018, 235 S., ISBN: 978-0-8101-3763-9 (paper), 34,95 $. Besprochen von Hans-Joachim Hahn

Auswirkung von Setzungseffekten und variabler Randporosität auf die Leistung von Hochtemperatur-Schüttspeichern

Zur Flexibilisierung fossil befeuerter Kraftwerke sowie für den Betrieb von Kraftwerken im Bereich der erneuerbaren Energien sind effiziente thermische Hochtemperaturenergiespeicher von entscheidender Bedeutung. In solarthermischen Turmkraftwerken ermöglichen sie den Betrieb in Zeiten ohne direkte Sonneneinstrahlung, in fossilen Kraftwerken verbessern sie die Betriebsflexibilität. Im geforderten Temperaturbereich von 500-1000°C bieten sich direktdurchströmte Feststoffspeicher mit den Wärmeträgern Luft oder Rauchgas als Speichertechnologie an. Diese als Regeneratorspeicher bekannte Technologie wird in der Stahl- und Glasindustrie eingesetzt, dort werden keramische Formsteine als Speichermaterial verwendet. Für den Einsatz in Kraftwerksanwendungen ist eine Verbesserung der Kosteneffizienz notwendig, welche mit herkömmlichen Inventaroptionen jedoch schwer erreichbar ist. Schüttungen bieten sich als Alternative zu Formsteinen an, bergen aber erhebliche thermomechanische und strömungsmechanische Risiken. Die Ausführung als horizontal durchströmter Speicher mindert durch die verminderte Schütthöhe die thermomechanischen Risiken auf Grund reduzierter Eigengewichtsbelastung. Im Fokus dieses Beitrags steht die strömungsmechanische Untersuchung der Auswirkung von Realeffekten in Schüttungen wie die verminderte Randporosität und die Ausbildung einer Bypassströmung durch Setzungseffekte bei horizontal durchströmten Speichern. Durch diese Effekte sinkt in den betroffenen Bereichen der Strömungswiderstand was zu einer stärkeren Durchströmung führt. Daraus resultiert eine ungleichförmige thermische Be- und Entladung des Speichers, welche zu einem Verlust an Leistung führen kann. Der Beitrag quantifiziert diese Effekte mittels instationärer CFD-Berechnungen für den zyklischen Speicherbetrieb. Die Einzeleffekte werden separiert und ihre Auswirkung auf die thermische Leistung anhand von Kenngrößen ermittelt

Supernova Remnants with H.E.S.S.: Systematic Analysis and Population Synthesis

One of the most prominent classes of astrophysical particle accelerators are supernova remnants. These objects result from the interaction of stellar material, being ejected during supernova explosions at velocities of several thousands of kilometres per second, with the ambient medium. The H.E.S.S. experiment is able to observe such sources at very-high-energies (>100 GeV) with the best possible sensitivity to date. As a first part of this work, a simulation of the theoretically expected population of supernova remnants at these energies was performed, followed by an analysis of the very-high-energy gamma-ray emission from the source ensemble known at other wave lengths. Assuming currently accepted standard parameters, the simulation is able to reproduce the observed numbers of supernova remnants in the radio as well as the very-high-energy range, but only if these objects amplify their own magnetic field. It should be mentioned, however, that a large number of parameters is required in the simulation, many of which are attributed with large uncertainties. The data analysis did not result in any new detections but allowed it to determine over a hundred flux upper limits. A hint of a faint, cumulated emission from the ensemble of supernova remnants might have been observed. A comparison to the developed model gives an explanation for the gamma-ray faintness of the investigated objects and suggests a possible detection of over a hundred supernova remnants with the next generation of Cherenkov telescope experiments

Neue Beschleuniger 14C-Daten zum Jungpaläolithikum in Südwestdeutschland

Eine neue Datierungsmethocle mit dem Beschleuniger - AMS - hat der 14C-Methode zusammen mit der Kalibration weit in das Jungpleistozän hinein neue Möglichkeiten eröffnet. Eine Reihe Proben aus südwestdeutschen jungpaläolithischen Fundstellen, vor allem Geißenklösterle und Hohle Fels wurden damit datiert. Fuldas Aurignacien und das Gravettien stellen sich erhebliche Abweichungen gegenüber den bisherigen Ansätzen heraus, die jedoch anderen neueren Datierungen in Europa entsprechen. Demnach beginnt das ältere Jungpaläolithikum mit dem Protoaurignacien um 40 ka, das „mittlere" Aurignacien mit Geschoßspitzen mit gespaltener Basis ist um 36 ka und das Gravettien ist zwischen 29 und 27 ka anzusetzen. Besiedlungsgeschichtlich und in bezug auf die Quartärchronologie hat das Konsequenzen für die Verbreitung des Homo sapiens sapiens nach Europa. Das Magdalénien hingegen bleibt in dem bisherigen zeitlichen Rahmen. Eine zweite Serie von AMS-Daten soll aber diese Ergebnisse überprüfen.researc

Fluid distribution kinetics during cardiopulmonary bypass

OBJECTIVE: The purpose of this study was to examine the isovolumetric distribution kinetics of crystalloid fluid during cardiopulmonary bypass. METHODS: Ten patients undergoing coronary artery bypass grafting participated in this prospective observational study. The blood hemoglobin and the serum albumin and sodium concentrations were measured repeatedly during the distribution of priming solution (Ringer's acetate 1470 ml and mannitol 15% 200 ml) and initial cardioplegia. The rate of crystalloid fluid distribution was calculated based on 3-min Hb changes. The preoperative blood volume was extrapolated from the marked hemodilution occurring during the onset of cardiopulmonary bypass. Clinicaltrials.gov: NCT01115166. RESULTS: The distribution half-time of Ringer's acetate averaged 8 minutes, corresponding to a transcapillary escape rate of 0.38 ml/kg/min. The intravascular albumin mass increased by 5.4% according to mass balance calculations. The preoperative blood volume, as extrapolated from the drop in hemoglobin concentration by 32% (mean) at the beginning of cardiopulmonary bypass, was 0.6-1.2 L less than that estimated by anthropometric methods (

Creating a high-resolution picture of Cygnus with the Cherenkov Telescope Array

The Cygnus region hosts one of the most remarkable star-forming regions in the Milky Way. Indeed, the total mass in molecular gas of the Cygnus X complex exceeds 10 times the total mass of all other nearby star-forming regions. Surveys at all wavelengths, from radio to gamma-rays, reveal that Cygnus contains such a wealth and variety of sources---supernova remnants (SNRs), pulsars, pulsar wind nebulae (PWNe), H II regions, Wolf-Rayet binaries, OB associations, microquasars, dense molecular clouds and superbubbles---as to practically be a galaxy in microcosm. The gamma-ray observations along reveal a wealth of intriguing sources at energies between 1 GeV and tens of TeV. However, a complete understanding of the physical phenomena producing this gamma-ray emission first requires us to disentangle overlapping sources and reconcile discordant pictures at different energies. This task is made more challenging by the limited angular resolution of instruments such as the Fermi Large Area Telescope, ARGO-YBJ, and HAWC and the limited sensitivity and field of view of current imaging atmospheric Cherenkov telescopes (IACTs). The Cherenkov Telescope Array (CTA), with its improved angular resolution, large field of view, and order of magnitude gain in sensitivity over current IACTs, has the potential to finally create a coherent and well-resolved picture of the Cygnus region between a few tens of GeV and a hundred TeV. We describe a proposed strategy to study the Cygnus region using CTA data, which combines a survey of the whole region at $65^{\circ} < l < 85^{\circ}$ and $-3.5^{\circ} < b < 3.5^{\circ}$ with deeper observations of two sub-regions that host rich groups of known gamma-ray sources.Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.0589

Can perioperative hemodilution be monitored with non-invasive measurement of blood hemoglobin?

BACKGROUND Trends in non-invasive measurements of blood hemoglobin (Hb) may be useful for identifying the need for transfusion in the perioperative period. METHODS Crystalloid fluid (5-20 mL/kg) was administered intravenously or by mouth to 30 volunteers and 33 surgical patients in five non-randomized clinical studies where Hb was measured on 915 occasions by non-invasive (Radical-7™) and invasive methodology. The hemodilution curves were compared by volume kinetic analysis and linear regression, with the slope and scattering of the data as key outcome measures. RESULTS The slope was 1.0, indicating unity between the two modes of measuring Hb when crystalloid fluid was infused in volunteers; however, only 40-45% of the variability in the non-invasive Hb could be explained by the invasive Hb. Patients undergoing major surgery, who showed the most pronounced hemodilution (median 24 g/L); non-invasive Hb explained 72% of the variability but indicated only half the magnitude of the invasive Hb changes (slope 0.48, P < 0.001 versus the volunteers). Simulations based on volume kinetic parameters from the volunteers showed 25% less plasma volume expansion after infusion when based on non-invasive as compared to invasive Hb, while no difference was found during infusion. CONCLUSIONS In volunteers the non-invasive Hb had good accuracy (low bias) but poor precision. In surgical patients the non-invasive Hb had good precision but systematically underestimated the hemodilution. Despite severe limitations, the non-invasive technology can be used to follow Hb trends during surgery if supported by occasional invasive measurements to assure acceptable quality of the hemodilution curve. TRIAL REGISTRATIONS ControlledTrials.gov NCT01195025, NCT01062776, NCT01458678, NCT03848507, and NCT01360333 on September 3, 2010, February 4, 2010, October 25, 2011, February 20, 2019, and May 25, 2011, respectively