Optimierung der Kühlung supraleitender Stromkabel

Im Zuge der Energiewende rücken supraleitende Stromkabel in den Fokus, um große Mengen elektrischer Energie in dicht besiedelten Gebieten aber auch über weite Strecken zu transportieren. Für einen ökonomischen und energieeffizienten Betrieb dieser Kabel unterhalb der Sprungtemperatur (deutlich unter 100 K) werden Kälteanlagen benötigt, welche die Betriebskosten maßgeblich beeinflussen. Der Kältebedarf setzt sich hierbei aus der Kühlung der Stromzuführungen und dem Rückkühlen des Kältemittels im Kabel zusammen. Neben den entsprechenden Kühlstationen an den beiden Enden eines Kabels sind je nach Länge zusätzliche Zwischenkühlstationen nötig, um stets einen sicheren Betrieb gewährleisten zu können. In diesem Beitrag werden verschiedene bestehende technische Prozesse zur Bereitstellung der niedrigen Temperaturen analysiert und mit kryogenen Gemischkältekreisläufen (cryogenic mixed‐refrigerant cycles, CMRC) auf Basis des Joule-Thomson-Effekts verglichen. Die Besonderheit der Gemischkältekreisläufe liegt hierbei in der Kombination von guter Skalierbarkeit der Kälteleistung, Anpassbarkeit des Gemischs an die spezifische Anwendung (End- oder Zwischenstation) und einem einfachen und somit günstigen Prozessaufbau

Impact of the Level of Homogenization in 3D Thermal Simulation on the Internal Temperature Distribution of Li-Ion Battery Cells

Temperature is an important factor for an optimal battery performance. To gain knowledge about the internal temperature distribution in a battery, many thermal simulation studies are performed. Among other factors, they differ in the level of homogenization (LoH) of the geometry, which directly influences the computing time. However, the effects of different LoH, in particular of the cell layers, on the modeling and prediction quality of the temperature field are scarcely investigated. This work discusses the effect of different LoH of the cell stack on a numerical 3D thermal battery model for different thermal management strategies. A new approach of reducing the number of cell layers of the pouch cell geometry while keeping their volumetric proportions constant is proposed. It is clearly shown that the LoH has a large impact on the thermal transport paths, especially through the current collectors and tabs, and therefore on the predicted internal temperature distribution. In addition, the effect of the LoH differs for different thermal management strategies, because they affect the heat transport paths as well

Globalisation and the spatial concentration of production

Abstract In new trade theory (NTT) models, freer trade tends to increase the spatial concentration of industrial production across countries. While nations with large home markets and central geographical location become increasingly attractive business locations, small peripheral countries gradually deindustrialise. Using data for 26 industries, 20 OECD countries and 20 years, we investigate the empirical validity of this claim. Separating out the role of home market size from geographical factors, and using various panel methods, we find robust evidence in line with theory. Freer trade has indeed magnified the importance of domestic demand and geographical location for the pattern of industrial production across the globe and has therefore exacerbated spatial disparities. Keywords: Home market effect, hub effect, trade liberalisation, trade costs, increasing returns to scale, new trade theory, economic geography. JEL-Codes: F12, F15 * We are grateful to an anonymous referee for helpful suggestions and comments. Parts of this paper were drafted when Niepmann was an intern at the World Bank. We are grateful to Mary Amiti, Michael Boehm, Giancarlo Corsetti, Matthieu Crozet, Benjamin Jung, Wilhelm Kohler, Andreas Kopp, and Davide Sala, as well as to seminar participants at EUI Florence and at the RIEF Meeting 2009 in Aix en Provence for comments and discussion. All remaining errors are ours

The IFN-γ-Inducible GTPase, Irga6, Protects Mice against Toxoplasma gondii but Not against Plasmodium berghei and Some Other Intracellular Pathogens

Clearance of infection with intracellular pathogens in mice involves interferon-regulated GTPases of the IRG protein family. Experiments with mice genetically deficient in members of this family such as Irgm1(LRG-47), Irgm3(IGTP), and Irgd(IRG-47) has revealed a critical role in microbial clearance, especially for Toxoplasma gondii. The in vivo role of another member of this family, Irga6 (IIGP, IIGP1) has been studied in less detail. We investigated the susceptibility of two independently generated mouse strains deficient in Irga6 to in vivo infection with T. gondii, Mycobacterium tuberculosis, Leishmania mexicana, L. major, Listeria monocytogenes, Anaplasma phagocytophilum and Plasmodium berghei. Compared with wild-type mice, mice deficient in Irga6 showed increased susceptibility to oral and intraperitoneal infection with T. gondii but not to infection with the other organisms. Surprisingly, infection of Irga6-deficient mice with the related apicomplexan parasite, P. berghei, did not result in increased replication in the liver stage and no Irga6 (or any other IRG protein) was detected at the parasitophorous vacuole membrane in IFN-γ-induced wild-type cells infected with P. berghei in vitro. Susceptibility to infection with T. gondii was associated with increased mortality and reduced time to death, increased numbers of inflammatory foci in the brains and elevated parasite loads in brains of infected Irga6-deficient mice. In vitro, Irga6-deficient macrophages and fibroblasts stimulated with IFN-γ were defective in controlling parasite replication. Taken together, our results implicate Irga6 in the control of infection with T. gondii and further highlight the importance of the IRG system for resistance to this pathogen

Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors

Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe

Wer? Wie? Wann? Die Geschichte der Gender Studies Hannover.

Winter S. Wer? Wie? Wann? Die Geschichte der Gender Studies Hannover. In: Boehm S, Kämpfe F, eds. Anecken und Weiterdenken. Aktuelle Beiträge zur Geschlechterforschung. Hamburg: Argument; 2013: 13-34