Die Bedeutung der Fascia stylopharyngea bei intraoralen Blockadetechniken

Zusammenfassung: Hintergrund: Mittels transoraler Blockade des Ganglion cervicale superius des Truncus sympathicus kann bei Trigeminusneuralgien durch Ausbreitung eines Opioids bis zum N.mandibularis eine zusätzliche Schmerzreduktion erzielt werden. Das Vorhandensein der Fascia stylopharyngea senkt möglicherweise die Erfolgsrate. Durch genaue anatomische Untersuchung der Faszie wollen wir auf die Effektivität der zusätzlichen Opioidwirkung rückschließen. Material und Methode: 103 Kopfhälften wurden untersucht, die Faszie von lateral her aufgesucht. Dabei unterschieden wir 3 Gruppen: GruppeA repräsentierte vollständig ausgebildete Faszienblätter, Gruppe Bunvollständige Faszien und in GruppeC war die Faszie nicht ausgebildet. Ergebnis: Die Faszie war in 86 vollständig und in 13 Fällen unvollständig ausgebildet. Lediglich in 4 Fällen fehlte sie vollends. Schlussfolgerung: Die Faszie kann die Erfolgsquote der Schmerzreduktion bei Trigeminusneuralgie beeinflusse

Phenomenological investigation of sodium boiling in a SFR core during a postulated ULOF transient with CATHARE 2 system code: a stabilized boiling case

International audienceIn the framework of the research and development on GEN IV sodium fast reactors (SFRs), the phenomenology of sodium boiling during a postulated unprotected loss of flow (ULOF) transient has been investigated with the CATHARE 2 system code. This study focuses on a stabilized boiling case: in such a regime, no flow redistribution occurs from the subassemblies which have reached the saturation temperature to those that are still single-phase. In this paper, for a subassembly design featuring no restrictive structures above the fuel bundle, a quasi-static approach is first developed to get an upper bound of the reactor core power at boiling onset that would be compatible with the well-known Ledinegg criteria for diphasicflowstaticequilibrium.Then,dynamicsresultsachievedthroughsimulationwiththeCATHARE 2 code for a postulated ULOF are presented: boiling is shown to remain stable during the transient for such a core power at boiling onset. Another important outcome of the simulation is the calculation of a dynamic instability, in the form of a two-phase hydrodynamic chugging phenomenon. The predicted phenomenology of this stabilized boiling case should be studied further in order to consider its dependency on the underlying closure laws and to eliminate the possibility of a numerical instability

IAEA NAPRO Coordinated Research Project : Heat Transfer and Pressure Drop Correlations for Sodium Cooled Systems

International audienceIn 2013 the International Atomic Energy Agency (IAEA) established a Coordinated Research Project (CRP) on “Sodium properties and safe operation of experimental facilities in support of the development and deployment of Sodium Cooled Fast Reactors”, the socalled CRP-NAPRO project to be carried out in the time period of 2013–2017. This activity has the aim toestablish a common database of sodium properties and related correlations, as well as other important sodium technology related issues, thus contributing to the enhanced safety of future sodium cooled systems. The CRP work package WP 1.2, under the leadership of Karlsruhe Institute of Technology (KIT), is focused on the collection and assessment of heat transfer and pressure drop (friction factor) correlations for sodium cooled systems. In the end result, this activity will lead to arecommendation of qualified correlations for conditions occurring in sodium systems, such as forced convection and natural convection for circular tubes, rod bundles, wire-wrapped tubes, etc., which will be published in the form of separate chapter(s) of a general handbook. This work is carried out by five participating organizations from IAEA Member States through the review and evaluation of the existing correlations and the development of recommendations for experts working on sodium cooled systems. The implemented methodology for WP 1.2 is described, as well as the heat transfer and pressure drop (friction factor) correlations included in WP 1.2 and their classification. Major findings to date related to WP 1.2 are presented in this paper. The last section of the paper also includes preliminary conclusions from WP 1.2, as well as a list of the main correlations used by the participating organizations when simulating sodium cooled fast reactors and other sodium cooled systems