In-Vessel Coil Material Failure Rate Estimates for ITER Design Use

The ITER international project design teams are working to produce an engineering design for construction of this large tokamak fusion experiment. One of the design issues is ensuring proper control of the fusion plasma. In-vessel magnet coils may be needed for plasma control, especially the control of edge localized modes (ELMs) and plasma vertical stabilization (VS). These coils will be lifetime components that reside inside the ITER vacuum vessel behind the blanket modules. As such, their reliability is an important design issue since access will be time consuming if any type of repair were necessary. The following chapters give the research results and estimates of failure rates for the coil conductor and jacket materials to be used for the in-vessel coils. Copper and CuCrZr conductors, and stainless steel and Inconel jackets are examined

Review of Maintenance and Repair Times for Components in Technological Facilities

This report is a compilation of some unique component repair time data and it also presents citations of more extensive reports where lists of repair times can be found. This collection of information should support analysts who seek to quantify maintainability and availability of high technology and nuclear energy production systems. While there are newer sources of repair time information, most, if not all, of the newer sources are proprietary and cannot be shared. This report offers data that, while older, is openly accessible and can serve as reasonable estimates of repair times, at least for initial studies. Some times were found for maintenance times in radiation environments, and some guidance for multiplicative factors to use to account for work in contamination areas

Dust Combustion Safety Issues for Fusion Applications

This report summarizes the results of a safety research task to identify the safety issues and phenomenology of metallic dust fires and explosions that are postulated for fusion experiments. There are a variety of metal dusts that are created by plasma erosion and disruptions within the plasma chamber, as well as normal industrial dusts generated in the more conventional equipment in the balance of plant. For fusion, in-vessel dusts are generally mixtures of several elements; that is, the constituent elements in alloys and the variety of elements used for in-vessel materials. For example, in-vessel dust could be composed of beryllium from a first wall coating, tungsten from a divertor plate, copper from a plasma heating antenna or diagnostic, and perhaps some iron and chromium from the steel vessel wall or titanium and vanadium from the vessel wall. Each of these elements has its own unique combustion characteristics, and mixtures of elements must be evaluated for the mixture’s combustion properties. Issues of particle size, dust temperature, and presence of other combustible materials (i.e., deuterium and tritium) also affect combustion in air. Combustion in other gases has also been investigated to determine if there are safety concerns with “inert” atmospheres, such as nitrogen. Several coolants have also been reviewed to determine if coolant breach into the plasma chamber would enhance the combustion threat; for example, in-vessel steam from a water coolant breach will react with metal dust. The results of this review are presented here

Failure Rate Data Analysis for High Technology Components

Understanding component reliability helps designers create more robust future designs and supports efficient and cost-effective operations of existing machines. The accelerator community can leverage the commonality of its high-vacuum and high-power systems with those of the magnetic fusion community to gain access to a larger database of reliability data. Reliability studies performed under the auspices of the International Energy Agency are the result of an international working group, which has generated a component failure rate database for fusion experiment components. The initial database work harvested published data and now analyzes operating experience data. This paper discusses the usefulness of reliability data, describes the failure rate data collection and analysis effort, discusses reliability for components with scarce data, and points out some of the intersections between magnetic fusion experiments and accelerators

Lift truck safety review

This report presents safety information about powered industrial trucks. The basic lift truck, the counterbalanced sit down rider truck, is the primary focus of the report. Lift truck engineering is briefly described, then a hazard analysis is performed on the lift truck. Case histories and accident statistics are also given. Rules and regulations about lift trucks, such as the US Occupational Safety an Health Administration laws and the Underwriter`s Laboratories standards, are discussed. Safety issues with lift trucks are reviewed, and lift truck safety and reliability are discussed. Some quantitative reliability values are given

The Signs of Maize? A Reconsideration of What δ¹³C Values Say about Palaeodiet in the Andean Region

Palaeodietary isotope studies have long assumed C_4 signals in South American archaeological populations to be due to the consumption of maize (Zea mays), which in turn, underlie interpretations important social processes. We presents δ¹³C data from wild plants (n=89) from the south coast of Peru, which may have been significant in the diets of humans and animals in the past. A combination of these with previously published results from domesticates of the Andean region (n=144) brings the proportion of C_4 species likely to have contributed to the human dietary isotopic signal, whether directly or indirectly, to almost one third. This undermines the widespread assumption that maize is the only plant to contribute a C_4 signal to diets. By considering both direct and indirect routes whereby C_4 plants may have contributed to the human isotopic signal we show the need for a reassessment of how palaeodietary studies are interpreted in the Andes, and perhaps elsewhere in the Americas.LC would like to thank the AHRC, the Anthony Wilkins Fund and the Santander Universities Grant for Travel to Latin America for enabling this research. TCO would like to thank the Wellcome Trust.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s10745-012-9509-0

The provenance, date and significance of a Cook-voyage Polynesian sculpture

A unique wooden sculpture collected by James Cook during his first voyage to the Pacific is widely considered to be a masterpiece of Oceanic art, but its exact provenance has been unclear. New analysis of shavings from the object now indicate that a) the tree from which it was carved was felled between 1690 and 1728, and that the carving was therefore up to 80 years old when obtained, and b) it originated in Tahiti, despite its stylistic affinities with art from the Austral Islands. Motifs and forms clearly travelled within regions, and populations interacted in ways that blur presumed tribal boundaries. It is perhaps time to reconsider the association between region and style upon which the cataloguing and identification of objects routinely depends.The research reported upon here has taken place in the context of two projects, 'Artefacts of Encounter', funded by the UK Arts and Humanities Research Council over 2010-13, and 'Pacific Presences', funded by the European Research Council over 2013-18. We are grateful to both agencies for their support. We also thank: Julie Adams (British Museum); Peter Brunt (Victoria University); Caroline Cartwright (British Museum); Steven Hooper (University of East Anglia); JeanYves Meyer (Ministère des Ressources Marines, des Mines et de la Recherche, Polynésie Française); Mark Nesbitt (Economic Botany Collection, Royal Botanic Gardens, Kew); Tamsin O’Connell (Dorothy Garrod Laboratory for Isotopic Analysis, McDonald Institute for Archaeological Research); Jessica Royles (Department of Plant Sciences, University of Cambridge); Matthew Spriggs (Australian National University); and the University of Oxford Radiocarbon Accelerator Unit

Radiation Protection Instrument Reliability and Ma

This report is a collection of reliability and ma

Dating the dead: New radiocarbon dates from the lower Ica Valley, south coast Peru

This article presents radiocarbon dates from human bone samples (n = 13) from seven pre-Columbian cemeteries in the Samaca and Ullujaya Basins of the lower Ica Valley, south coast of Peru, spanning from the end of the Early Horizon to the Inca Late Horizon. These contexts have been severely looted. Yet, in all cases, their putative dating by material culture remains is confirmed by these 14C dates. This shows that such disturbed contexts, sadly typical of the Peruvian coast, can nonetheless still yield valuable bioarchaeological and burial practice data. These dates elaborate upon an emerging picture of the absolute dating of the cultural phases of the wider south coast region, in particular casting new light on the poorly understood Middle Horizon to Late Intermediate period transition. A paucity of archaeological data for this 3-century period has been taken as evidence of some sort of environmentally or socially induced lacuna. Instead, the 14C dates presented here suggest that the basins of the lower Ica Valley were continuously occupied over this period.We thank the Ministerio de Cultural del Perú for granting permission for the fieldwork (No. 0028-2010-VMPCIC-MC) and analysis of samples for dating (No. 369-2011-VMPCIC-MC); Alberto Benavides Ganoza and the people of Samaca for facilitating fieldwork; the Arts and Humanities Research Council for LC's doctoral funding; the NERC Radiocarbon Facility for funding radiocarbon dating (grant number NF/2012/1/7 to TCO’C and LC); and Tom Higham, Diane Baker, Ingmar Unkel and Elmo Leon for their help and advice.This is the final version of the article. It first appeared from University of Arizona via http://dx.doi.org/10.2458/azu_rc.57.1834

Post-transcriptional regulation of satellite cell quiescence by TTP-mediated mRNA decay.

Skeletal muscle satellite cells in their niche are quiescent and upon muscle injury, exit quiescence, proliferate to repair muscle tissue, and self-renew to replenish the satellite cell population. To understand the mechanisms involved in maintaining satellite cell quiescence, we identified gene transcripts that were differentially expressed during satellite cell activation following muscle injury. Transcripts encoding RNA binding proteins were among the most significantly changed and included the mRNA decay factor Tristetraprolin. Tristetraprolin promotes the decay of MyoD mRNA, which encodes a transcriptional regulator of myogenic commitment, via binding to the MyoD mRNA 3' untranslated region. Upon satellite cell activation, p38α/β MAPK phosphorylates MAPKAP2 and inactivates Tristetraprolin, stabilizing MyoD mRNA. Satellite cell specific knockdown of Tristetraprolin precociously activates satellite cells in vivo, enabling MyoD accumulation, differentiation and cell fusion into myofibers. Regulation of mRNAs by Tristetraprolin appears to function as one of several critical post-transcriptional regulatory mechanisms controlling satellite cell homeostasis