OECD/CSNI ISP NR. 43 Rapid Boron Dilution Transient Tests For Code Verification Post Test Calculation With CFX-4

The need of the experimental support for validation of the computational tools to be applied to analyze the mixing of diluted slugs has been recognized in various countries. The test series for the International Standard Problem ISP-43 provides a platform for experiences to be applied to the simulation of a well-defined test series. Test A and B of the UM2x4 loop test facility were calculated with the CFD Code CFX-4.3. Sensitivity studies were made to analyze the used turbulence model and numerical errors. The results show good agreement with the experimental data for both tests

π\pi-Electron Ferromagnetism in Metal Free Carbon Probed by Soft X-Ray Dichroism

Elemental carbon represents a fundamental building block of matter and the possibility of ferromagnetic order in carbon attracted widespread attention. However, the origin of magnetic order in such a light element is only poorly understood and has puzzled researchers. We present a spectromicroscopy study at room temperature of proton irradiated metal free carbon using the elemental and chemical specificity of x-ray magnetic circular dichroism (XMCD). We demonstrate that the magnetic order in the investigated system originates only from the carbon $\pi$-electron system.Comment: 10 pages 3 color figure

CFD-Post Test Analysen der dichtegetriebenen Vermischungsexperimente an der ROCOM Versuchsanlage

An der Anlage ROCOM wurden Experimente durchgeführt, um den Einfluss von Dichtedifferenzen und die Bedingungen des Übergangs zwischen auftriebsdominierter und impulsbetriebener Vermischung generisch zu untersuchen. In den Experimenten mit Dichteunterschieden wurden keine konkreten Störfallszenarien nachgebildet. In diesem Bericht werden nun die experimentellen Ergebnisse mit den Resultaten des Strömungsberechnungsprogrammes CFX-4 verglichen. Die Nachrechnung der Dichteexperimente an der ROCOM-Versuchsanlage ergab für die Randfälle impulsdominierte bzw. dichtedominierte Strömung als auch für Zwischenstadien eine gute qualitative Übereinstimmung mit den beobachteten, sehr unterschiedlichen Vermischungsbildern

Exploring the functional domain and the target of the tetanus toxin light chain in neurohypophysial terminals

The tetanus toxin light chain blocks calcium induced vasopressin release from neurohypophysial nerve terminals. Here we show that histidine residue 233 within the putative zinc binding motif of the tetanus toxin light chain is essential for the inhibition of exocytosis, in the rat. The zinc chelating agent dipicolinic acid as well as captopril, an inhibitor of zinc-dependent peptidases, counteract the effect of the neurotoxin. Synthetic peptides, the sequences of which correspond to motifs present in the cytoplasmic domain of the synaptic vesicle membrane protein synaptobrevin 1 and 2, prevent the effect of the tetanus toxin light chain. Our results indicate that zinc bound to the zinc binding motif constitutes the active site of the tetanus toxin light chain. Moreover they suggest that cleavage of synaptobrevin by the neurotoxin causes the inhibition of exocytotic release of vasopressin from secretory granules

Cryopyrin-associated periodic fever syndrome manifesting as Tolosa-Hunt syndrome

Background Tolosa-Hunt syndrome (THS) is characterized by unilateral orbital pain, ipsilateral oculomotor paresis and a prompt response to treatment with corticosteroids. Several reports have demonstrated that the clinical features of THS are not specific to one causal aetiology and can lead to misdiagnosis. Case report We report the case of a patient diagnosed with THS after an episode of unilateral orbital pain and diplopia with demonstration of granulomatous inflammation of both cavernous sinus on cerebral magnetic resonance imaging and an immediate response to treatment with corticosteroids. Progression of the disease over the following years, accompanied by increasing signs of inflammation on cerebral magnetic resonance imaging and cerebrospinal fluid pleocytosis, led to further diagnostic tests. Genetic analyses revealed a heterozygote low-penetrance mutation (Q703K) of the cryopyrin/NLRP3 gene compatible with a cryopyrin-associated periodic fever syndrome. Discussion This case report demonstrates that THS can be a central nervous system manifestation of cryopyrin-associated periodic fever syndrome, which therefore represents a differential diagnosis of THS, even in elderly patients

Best scale for detecting the effects of stratospheric sulphate aerosol geoengineering on surface temperature

Stratospheric sulfate aerosol injection (SAI) has been proposed as a way to geo-engineer climate. Whilst swift global-mean surface cooling is generally expected from tropical SAI, the regional impacts of such perturbation on near-surface air temperature (SAT) are projected to be spatially inhomogeneous. By using existing simulations from the Geoengineering Model Intercomparison Project (GeoMIP) G4 scenario, where 5 Tg yr-1 of sulfur dioxide (SO2) is injected into the tropical stratosphere to offset some of the warming in a mid-range representative greenhouse gas concentration pathway (RCP4.5) between 2020 and 2070, we examine the regional detectability of the SAI surface cooling effect, and attempt to find the best spatial scale for potential SAI monitoring. We use optimal fingerprint detection and attribution techniques to estimate the time horizon over which the SAI surface cooling effect would be detected after implementation in 2020 on sub-global scales, ranging from the near-global in situ observational coverage down to sub-continental regions. We show that using the spatio-temporal SAT pattern across the Northern and Southern extra-tropics and the Tropics, and across the Northern and Southern Hemispheres, as well as averaging SATs over the whole globe robustly result in successful SAI detection within 10 years of geoengineering implementation in a majority of the included plausible geoengineering realizations. However, detecting the SAI effect on SAT within the first decade of implementation would be more challenging on sub-continental scales

Induced Magnetic Ordering by Proton Irradiation in Graphite

We provide evidence that proton irradiation of energy 2.25 MeV on highly-oriented pyrolytic graphite samples triggers ferro- or ferrimagnetism. Measurements performed with a superconducting quantum interferometer device (SQUID) and magnetic force microscopy (MFM) reveal that the magnetic ordering is stable at room temperature.Comment: 3 Figure