217 research outputs found
Thermal evolution and sintering of chondritic planetesimals III. Modelling the heat conductivity of porous chondrite material
The construction of models for the internal constitution and the temporal
evolution of large planetesimals, the parent bodies of chondrites, requires
information on the heat conductivity of the complex mixture of minerals and
iron metal found in chondrites. It is attempted to evaluate the heat
conductivity of a multi-component mineral mixture and granular medium from the
heat conductivities of its mixture components. Random mixtures of solids with
chondritic composition and packings of spheres are numerically generated. The
heat conduction equation is solved in high spatial resolution for a test cube
filled with such matter. From the heat flux through the cube the heat
conductivity of the mixture is derived. The model results for porous material
are consistent with data for compacted sandstone, but are at odds with
measurements for H and L chondrites. The discrepancy is traced back to shock
modification of the currently available meteoritic material by impacts on the
parent body over the last 4.5 Ga. This causes numerous micro-cracks that act as
additional barriers for heat transfer. The void structure in meteorites is
different from that which probably existed in the pristine material of the
parent bodies. The results obtained for the heat conductivity of the pristine
material are used for calculating models for the evolution of the H chondrite
parent body which are fitted to the cooling data of a number of H chondrites.
The fit to the data good.Comment: 19 pages, 8 figures, accepted by Astronomy & Astrophysic
Report and preliminary results of R/V SONNE Cruise SO251 - Extreme events Archived in the GEologial Record of JAPAN's subduction margins (EAGER-JAPAN)
Leg A SO251-1, Yokohama - Yokohama, 04.10.2016 - 15.10.2016, Leg B SO251-2, Yokohama - Yokohama, 18.10.2016 - 02.11.201
Complex networks for climate model evaluation with application to statistical versus dynamical modeling of South American climate
Acknowledgments: This paper was developed within the scope of the IRTG 1740/TRP 2011/50151-0, funded by the DFG/FAPESP. Furthermore, this work has been financially supported by the Leibniz Society (project ECONS), and the Stordalen Foundation (JFD). For certain calculations, the software packages pyunicorn (Donges et al. 2013a) and igraph (Csa´rdi and Nepusz 2006) were used. The authors would like to thank Manoel F. Cardoso, Niklas Boers, and the reviewers for helpful comments on the manuscript. Open Access: This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.Peer reviewedPostprin
A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.
The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world
Bürgerliche Modernisierungskrise und historische Sinnbildung: Kulturgeschichte bei Droysen, Burckhardt und Max Weber
Jaeger F. Bürgerliche Modernisierungskrise und historische Sinnbildung: Kulturgeschichte bei Droysen, Burckhardt und Max Weber. Bürgertum ; 5. Göttingen: Vandenhoeck & Ruprecht; 1994
Die Betriebsergebnisse eines Thomasstahlwerkes in Abhängigkeit von der wechselnden Ausnutzung der Produktionsanlagen unter besonderer Behandlung der auf die Betriebsergebnisse einwirkenden Einflüsse
Der Kulturbegriff im Werk Max Webers und seine Bedeutung für eine moderne Kulturgeschichte
- …