Ex-vessel remote maintenance for the Compact Ignition Tokamak

The use of deuterium-tritium (D-T) fuel for operation of the Compact Ignition Tokamak (CIT) requires the use of remote handling technology to carry out maintenance operations on the machine. These operations consist in removing and repairing such components as diagnostic modules by using remotely operated maintenance equipment. The major equipment being developed for maintenance external to the plasma chamber includes a bridge-mounted manipulator system for test cell operations, decontamination (decon) equipment, hot cell equipment, and solid-radiation-waste-handling equipment. Wherever possible, the project will use commercially available equipment. Several areas of the maintenance system design were addressed in fiscal year (FY) 1987, including conceptual designs of manipulator systems, the start of a remote equipment research and development (RandD) program, and definition of the hot cell, decon, and equipment repair facility requirements. R and D work included preliminary demonstrations of remote handling operations on full-size, partial mock-ups of the CIT machine at the Oak Ridge National Laboratory (ORNL) Remote Operations and Maintenance Development (ROMD) Facility. 1 ref., 6 figs

Maintainability features of the compact ignition tokamak

The Compact Ignition Tokamak (CIT) is a deuterium-tritium (D-T) device envisaged to be the next experimental reactor in the US Fusion Program. The reactor will initially operate in a nonactivated hydrogen phase for approximately two years. This will permit verification of the integrity of the total system and allow hands-on repair to equipment which has experienced shakedown and early operation failures. Once D-T operations commence, reactor maintenance will require remote handling techniques. An evaluation has been completed to determine what maintenance operations must be performed on the CIT. A maintenance philosophy has been developed which is based upon the use of manipulator systems and robotics in the test cell. Replacement of life-limited equipment will be accomplished using a modular design approach for components, with simple remotely operable interfaces. Examples of operations to be done remotely include: (1) replacing of rf antennae and Faraday shields, (2) uncoupling diagnostic and fueling penetrations, (3) removing of all port covers, and (4) replacing first wall armor tiles, optical mirrors, and vacuum windows

Cerebellar direct current stimulation enhances on-line motor skill acquisition through an effect on accuracy

The cerebellum is involved in the update of motor commands during error-dependent learning. Transcranial direct current stimulation (tDCS), a form of noninvasive brain stimulation, has been shown to increase cerebellar excitability and improve learning in motor adaptation tasks. Although cerebellar involvement has been clearly demonstrated in adaptation paradigms, a type of task that heavily relies on error-dependent motor learning mechanisms, its role during motor skill learning, a behavior that likely involves errordependent as well as reinforcement and strategic mechanisms, is not completely understood. Here, in humans, we delivered cerebellar tDCS to modulate its activity during novel motor skill training over the course of 3 d and assessed gains during training (on-line effects), between days (off-line effects), and overall improvement. We found that excitatory anodal tDCS applied over the cerebellum increased skill learning relative to sham and cathodal tDCS specifically by increasing on-line rather than off-line learning. Moreover, the larger skill improvement in the anodal group was predominantly mediated by reductions in error rate rather than changes in movement time. These results have important implications for using cerebellar tDCS as an intervention to speed up motor skill acquisition and to improve motor skill accuracy, as well as to further our understanding of cerebellar function

Installazione di un radiometro nell'area sommitale del vulcano Etna

Le tecniche di telerilevamento satellitare e da terra per la stima della temperatura di anomalie termiche delle superfici vulcaniche, della loro variazione nel tempo e per individuare attività parossistiche o l’inizio di una fase di colate di lava, sono ormai entrate a far parte della sorveglianza e del monitoraggio vulcanologico [es. Francis, 1979; Geraci et al., 1985; Lombardo et al., 2011; Spampinato et al., 2011]. I sensori in una banda spettrale dell’infrarosso quali radiometri e telecamere termiche, utilizzati in prossimità di bocche eruttive, hanno fornito cospicue quantità di dati di temperatura della superficie di corpi magmatici (colate laviche, laghi di lava, duomi lavici), plume vulcanici, fumarole, registrati a distanza di totale sicurezza [Spampinato et al., 2011]. In particolare, i radiometri, sia portatili che installati in stazioni permanenti, oltre che fornire dati da confrontare con misure geochimiche, permettono l’acquisizione di dati di temperatura ad elevata frequenza, tali da essere messi in relazione con le misure derivate da osservazioni geofisiche quali ad esempio il tremore sismico [es. Harris e Ripepe, 2007; Branan et al., 2008].In questo lavoro si descrivono i dettagli dell’installazione di una stazione radiometrica collocata nell’area sommitale dell’Etna in zona Belvedere, nel sito già utilizzato da una stazione multiparametrica (con sensori sismici e infrasonici) e denominato EBEL. Si descrivono anche la metodologia di trasmissione dati in continuo, il trattamento del dato convertito in temperatura apparente nel campo di vista del radiometro, la visualizzazione in tempo quasi reale del dato e la sua diffusione tramite WEB

Kombinationstherapie von Entecavir und DNA-Protein-Vakzinen bei chronischen Hepadnavirus-Infektionen im Murmeltier-Modell

Chronische HBV-Infektionen können Folgeschäden nach sich ziehen, z. B. eine Leberzirrhose oder primäre „hepatozelluläre“ Karzinome verursachen. Bisher wurden keine ausreichend wirksamen Monotherapien, z. B. mit Interferonen oder Nukleosidanaloga, gefunden, da Interferone Nebenwirkungen haben und Nukleosidanaloga bei Langzeit-Therapie Resistenzen entwickeln. Daher ist man auf die weitere Erforschung und Evaluierung von Kombinationstherapien angewiesen. Ziel dieser Doktorarbeit war es, eine Kombinationstherapie mit einem Nukleosidanalogon und einer therapeutischen Vakzine auf ihre Wirksamkeit zur Bekämpfung einer chronischen WHV-Infektion hin zu testen. Die grundsätzliche Fragestellung war, in wie weit diese Therapie helfen kann, eine chronische Infektion mit WHV zu beenden bzw. den besten Langzeiteffekt zur Reduktion der Virämie aufweist. Dazu wurden 4 Versuchsgruppen getestet. Gruppe 1 war die unbehandelte Kontrollgruppe, Gruppe 2 erhielt als Monotherapie das Nukleosidanalogon Entecavir (ETV) für 3 Monate täglich, dann für 3 Monate einmal wöchentlich. Die Gruppen 3 und 4 erhielten ebenfalls ETV mit dem gleichen Schema wie die Gruppe 2. Zusätzlich wurden die Tiere der Gruppe 3 ab dem 4. Monat mit einer DNA-Vakzine und die Gruppe 4 mit einer DNA-Protein-Kombinationsvakzine geimpft. In der Gruppe 2 konnte gezeigt werden, dass man durch die Gabe von ETV alleine eine deutliche Reduzierung der Viruslast erreichen kann. Allerdings hält diese Reduzierung nur für die Dauer der Gabe des Medikamentes an. Schon kurze Zeit nach Absetzen des ETV kam es zu einem erneuten Anstieg des Viruslast, der z. T. sogar noch höhere Werte als vor Beginn des Versuches annehmen konnte. Dies deckt sich auch mit früheren Arbeiten, in denen ein Effekt von ETV alleine für Dauer der Gabe gezeigt wurde. In den Gruppen 3 und 4 konnte z. T. eine dramatische Reduzierung der Viruslast, sogar unter die Nachweisgrenze, aufgezeigt werden. Der virämiesenkende Effekt der Kombinationstherapie durch die zusätzliche therapeutische Vakzinierung deutlich verlängert werden. Es gab sogar zwei Tiere, bei denen auch nach 43 Wochen kein messbarer Anstieg der Viruslast festgestellt werden konnte. Es konnte also gezeigt werden, dass der Einsatz von einer Kombinationstherapie aus dem Nukleosidanalogon ETV und einer therapeutischen DNA-Vakzine helfen kann, eine chronische Infektion zu beenden und eine stabile Immunität aufzubauen bzw. über den Zeitraum der Gabe von ETV hinaus eine deutliche Reduktion der Virämie zu erreichen. Dies legt den Schluss nahe, dass der Einsatz dieser Kombinationstherapie auch bei Patienten eine neue Behandlungsmöglichkeit der chronischen HBV-Infektion bietet. In Zukunft muss allerdings noch weiter untersucht werden, um die bestmögliche Kombination beider Behandlungsformen (ETV-Gabe, Vakzinierung) herauszufinden. Insbesondere die Länge der ETV-Gabe, Häufigkeit und Art der therapeutischen Vakzinierung (nur DNA- oder DNA-Protein-Kombinationstherapie), Menge des eingesetzten Antigens in der Vakzine, ist in nachfolgenden Arbeiten noch näher zu untersuchen.Possible consequences of chronic HBV-infections are liver cirrhosis or primary hepatocellular carcinomas. Until now there are no effective mono therapies known. Mono therapies contain the application of interferon’s or nucleoside analogas. The problems of interferons are unwelcome side effects and the developing of resistances during long time therapy of nucleoside analogues. Therefore the developing and evaluation of combination therapies is necessary. Aim of this study has been the test for the effectiveness of combination therapy. The combination therapy consists of the application of nucleoside analogas and therapeutic vaccinations. The main formulation of question has been the investigation either this therapy is able to stop a chronic HBV infection or has a measurable long time effect for reduction of viremia. The study contains of 4 groups of experiments. Group 1 is the control group, group receive only ETV as a mono therapy during 3 months daily and another 3 months weekly. Groups 3 and 4 receive also ETV within the same scheme like group 2. Additionally the animals receive either a DNA-vaccine or DNA-protein-combinationvaccine since the 4th month of therapy. The results of group 2 show a clear reduction of virus titers. But the effect of the reduction last as long as the application of ETV lasts. Shortly after dismission of ETV the virus titers decrease again. Other early papers also show this course. In contrast to these results the groups 3 and 4 show significant reduction of virus titers below detection level. Combination therapy prolongs the effect of decreasing vermeil clearly. There have been already two animals showing now longer virus titers in blood for 43 weeks altogether. This study confirms the positive results of combination therapy, containing therapeutic vaccination and intake of ETV. The combination of these two therapies helps stopping chronic HBV infections and building up firmable immunity already over and above the ETV intake. So there are new possible strategies and approaches for using the combination strategy in human patients within chronic HBV infection. Further investigations are necessary for finding out the possible combination of both axle of the therapy (including ETV-dose, vaccination). Especially the duration of ETV intake, frequency and kind of therapeutic vaccination, quantity of used antigen has to be content of further studies

Major eruptive style changes induced by structural modifications of a shallow conduit system: the 2007–2012 Stromboli case

Stromboli is known for its mild, persistent explosive activity from the vents located within the summit crater depression at the uppermost part of the Sciara del Fuoco (SdF) depression. Effusive activity (lava flows) at this volcano normally occurs every 5–15 years, involving often the opening of eruptive fissures along the SdF, and more rarely overflows from the summit crater. Between the end of the 2007 effusive eruption and December 2012, the number of lava flows inside and outside the crater depression has increased significantly, reaching a total of 28, with an average of 4.8 episodes per year. An open question is why this activity has become so frequent during the last 6 years and was quite rare before. In this paper, we describe this exceptional activity and propose an interpretation based on the structural state of the volcano, changed after the 2002–2003 and even more after the 2007 flank effusive eruption. We use images from the Stromboli fixed cameras network, as well as ground photos, plume SO2 and CO2 fluxes released by the summit crater, and continuous fumarole temperature recording, to unravel the interplay between magma supply, structural and morphology changes, and lava flow output. Our results might help forecast the future behaviour and hazard at Stromboli and might be applicable to other openconduit volcanoes.partially supported by the Project INGV-DPC Paroxysm V2/03, 2007–2009 funded by the Istituto Nazionale di Geofisica e Vulcanologia and the Italian Civil ProtectionPublished8413V. Dinamiche e scenari eruttiviJCR Journalrestricte

Metrology/viewing system for next generation fusion reactors

Next generation fusion reactors require accurate measuring systems to verify sub-millimeter alignment of plasma-facing components in the reactor vessel. A metrology system capable of achieving such accuracy must be compatible with the vessel environment of high gamma radiation, high vacuum, elevated temperature, and magnetic field. This environment requires that the system must be remotely deployed. A coherent, frequency modulated laser radar system is being integrated with a remotely operated deployment system to meet these requirements. The metrology/viewing system consists of a compact laser transceiver optics module which is linked through fiber optics to the laser source and imaging units that are located outside of the harsh environment. The deployment mechanism is a telescopic-mast positioning system. This paper identifies the requirements for the International Thermonuclear Experimental Reactor metrology and viewing system, and describes a remotely operated precision ranging and surface mapping system

The Merit(nTOF-11) High Intensity Liquid Mercury Target Experiment at the CERN PS

The MERIT(nTOF-11) experiment is a proof-ofprinciple test of a target system for a high power proton beam to be used as front-end for a neutrino factory or a muon collider. The experiment took data in autumn 2007 with the fast-extracted beam from the CERN Proton Synchrotron (PS) to a maximum intensity of $30 × 10^{12}$ per pulse. The target system, based on a free mercury jet, is capable of intercepting a 4-MW proton beam inside a 15-T magnetic field required to capture the low energy secondary pions as the source for intense muon beams. Partice detectors installed around the target setup measure the secondary particle flux out of the target and can probe cavitation effects in the mercury jet when excited by an intense proton beam.Preliminary results of the data analysis will be presented here

Etna 2004–2005: An archetype for geodynamically-controlled effusive eruptions

The 2004–05 eruption of Etna was characterised by outpouring of degassed lava from two vents within Valle del Bove. After three months of eruption lava volumes were estimated to be between 18.5 and 32 × 106 m3, with eruption rate between 2.3 and 4.1 m3/s. Petrological analyses show that magma is resident in the shallow plumbing system, emplaced during the last South-East Crater activity. SO2 flux data show no increase at the onset of the eruption and SO2/HCl ratios in gas emitted from the eruptive fissure are consistent with a degassed magma. No seismic activity was recorded prior to eruption, unlike eruptions observed since the 1980's. The purely effusive nature of this eruption, fed by a degassed, resident magma and the fracture dynamics suggest that magmatic overpressure played a limited role in this eruption. Rather, lateral spreading of Etna's eastern flank combined with general inflation of the edifice triggered a geodynamically-controlled eruption.Published1-4partially_ope