WorldWideScience

Sample records for argos reactor

  1. ARGOS un reactor a la diagonal

    OpenAIRE

    Barca Salom, Francesc Xavier

    2011-01-01

    El reactor Argos va funcionar des del 16 de gener de 1963 en què va aconseguir l’autorització provisional. Al 1976 el reactor fou aturat per exigències de la nova llei nuclear. Al 1987 es va procedir a la clausura i el 1992 es va enviar l’urani a la Gran Bretanya i es va engegar un procés de descontaminació i desmantellament. Va ser el primer reactor experimental construit majoritàriament a la Junta d'Energia Nuclear.

  2. La política nuclear espanyola: el caos del reactor nuclear Argos

    OpenAIRE

    Barca Salom, Francesc Xavier

    2000-01-01

    L’11 de juny de 1962 s’inaugurava a l’Escola Tècnica Superior d’Enginyeria Industrial de Barcelona un reactor nuclear experimental, que era batejat amb el nom mític d’Argos. Tota la premsa barcelonina se’n feu ressò i el presentava com el primer reactor construït íntegrament a Espanya per la Junta d’Energia Nuclear. La idea de dotar l’Escola d’un reactor nuclear havia nascut, però, set anys abans, precisament en el mateix moment de la creació de la Càtedra Ferran Tallada d’enginyeria...

  3. Argo Navis

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    (the Ship) a large southern constellation representing the ship Argo of Jason and the Argonauts in Greek mythology whose brightest stars were cataloged by Ptolemy (c. AD 100-175) in the Almagest. It was divided up by the French astronomer Nicolas L de Lacaille (1713-62), who charted the southern sky in 1751-2, into the constellations Carina (the Keel), Vela (the Sails), Puppis (the Poop or Stern)...

  4. The ARGO Project

    Science.gov (United States)

    Kozameh, C. N.

    El proyecto µARGO propone el desarrollo, construcción y operación del Observatorio Espacial de Rayos Gamma, que operará en una órbita terrestre. Este observatorio constará de un telescopio con capacidad de medir simultáneamente dirección de incidencia y polarización de rayos Gamma en dos rangos de energía: 50 KeV - 3 MeV y 10 MeV - 1 GeV. Para ello se usarán detectores de silicio de última generación y microelectrónica adaptada a la configuración. La masa total en órbita del observatorio estará en el orden de los 60 - 100 kg. dependiendo de la geometría adoptada lo que permitirá minimizar costos de desarrollo y construcción, sin perder por ello calidad en su misión científica. ? Desde el punto de vista energético μARGO cubrirá el rango cubierto por COMPTEL y EGRET del CGRO, duplicando como mínimo la resolución angular de ambos con una reducción de peso de dos órdenes de magnitud. En adición, μARGO podr´ medir la polarización incidente de los rayos energéticos. Si bien existen otros dos proyectos en marcha (GLAST y AGILE) para reemplazar EGRET que serán lanzados antes que μARGO, estos proyectos no están diseñados para medir polarización ni tampoco cubren el rango mas bajo de energía arriba mencionado.

  5. ARGO-YBJ Highlights

    CERN Document Server

    Di Sciascio, G

    2010-01-01

    The ARGO-YBJ experiment is a multipurpose detector exploiting the full-coverage approach at very high altitude. The apparatus is in stable data taking since November 2007 at the YangBaJing Cosmic Ray Laboratory (Tibet, P.R. China, 4300 m a.s.l., 606 g/cm$^2$). In this paper we report the main results in Gamma-Ray Astronomy and Cosmic Ray Physics after about 3 years of operations.

  6. Argos: an Automaton-Based Synchronous Language

    OpenAIRE

    Maraninchi, Florence; Rémond, Yann

    2001-01-01

    International audience Argos belongs to the family of synchronous languages, designed for programming reactive systems (Lustre, Esterel, Signal, ...). Argos is a set of operators that allow to combine Boolean Mealy machines, in a compositional way. It takes its origin in Statecharts, but with the Argos operators, one can build only a subset of Statecharts, roughly those that do not make use of multi-level arrows. We explain the main motivations for the definition of Argos, and the main dif...

  7. ARGOS PHWR 380. Argentine offer of a safer pressurized heavy-water reactor of 380 MW. '...a many-eyed guardian...' concerned about nuclear power plant safety

    International Nuclear Information System (INIS)

    Reactor vendors in most countries have had lean pickings for the past decade, and ordering seems unlikely to show much growth until the shock wave from the Chernobyl accident has died away. Paradoxically, however, at least one firm sees a niche in the market. ENACE - the Empresa Nuclear Argentina de Centrales Electricas, or Argentine Nuclear Power Plant Corporation - is stepping out into the market place with a newly-designed 380 MWe nuclear power plant. The plant is equipped with a pressurized heavy-water reactor of the pressure vessel type (PHWR). ENACE has adopted new boundary design conditions and has embodied a number of special features to assure safety and economy in operation. The major shareholder in ENACE is the Argentine National Atomic Energy Commission (CNEA). ENACE is the architect-engineer for the NPP projects of the Argentine nuclear programme. It has a licensing agreement with Siemens AG's Kraftwerk Union AG, which is its minor shareholder. Under this agreement, ENACE has the right to use the Siemens-KWU PHWR technology, which was originally developed for the MZFR reactor in the Federal Republic of Germany, as well as their know-how in pressurized (light-) water reactors (PWRs) design and construction. The CNEA also has agreements with Atomic Energy of Canada Ltd. for the transfer of technology related to CANDU-type PTHWRs. The CNEA and ENACE have acquired considerable practical experience from the construction and operation of the 367 MWe Atucha I PHWR and the 648 MWe Embalse PTHWR; ENACE is currently building Argentina's third nuclear power plant, Atucha II, a 745 MWe PHWR. (author)

  8. Puitmaja klaster : intervjuu Argo Sauliga / Argo Saul ; intervjueerinud Kalle Komissarov

    Index Scriptorium Estoniae

    Saul, Argo

    2010-01-01

    Eesti Puitmajaliidu juhatuse esimehe ning Nordic Houses osaniku ja juhatuse esimehe Argo Sauliga arhitektide ja tüüpmaja tootjate võimalikust koostööst Eesti puitmaja klastris, millega Eesti Arhitektide Liit on liitunud. Nordic Houses on norra arhitektide projektide järgi tootnud ja tarninud üle 700 puhkemaja Norrasse

  9. ARGoS: a modular, multi-engine simulator for heterogeneous swarm robotics

    OpenAIRE

    Pinciroli C; Trianni V; O'Grady R; Pini G; Brutschy A; Brambilla M; Mathews N; Ferrante E; Di Caro G; Ducatelle F

    2011-01-01

    We present ARGoS, a novel open source multi-robot simulator. The main design focus of ARGoS is the real-time simulation of large heterogeneous swarms of robots. Existing robot simulators obtain scalability by imposing limitations on their extensibility and on the accuracy of the robot models. By contrast, in ARGoS we pursue a deeply modular approach that allows the user both to easily add custom features and to allocate computational resources where needed by the experiment. A unique feature ...

  10. Animal Tracking ARGOS vs GPS

    Science.gov (United States)

    Robinson, P. W.; Costa, D.; Arnould, J.; Weise, M.; Kuhn, C.; Simmons, S. E.; Villegas, S.; Tremblay, Y.

    2006-12-01

    ARGOS satellite tracking technology has enabled a tremendous increase in our understanding of the movement patterns of a diverse array of marine vertebrates from Sharks to marine mammals. Our current understanding has moved from simple descriptions of large scale migratory patterns to much more sophisticated comparisons of animal movements and behavior relative to oceanic features. Further, animals are increasingly used to carry sensors that can acquire water column temperature and salinity profiles. However, a major limitation of this work is the spatial precision of ARGOS locations. ARGOS provides 7 location qualities that range from 3,2,1,0,A,B,Z and correspond to locations with a precision of 150m to tens of kilometers. Until recently, GPS technology could not be effectively used with marine mammals because they did not spend sufficient time at the surface to allow complete acquisition of satellite information. The recent development of Fastloc technology has allowed the development of GPS tags that can be deployed on marine mammals. Here we compare the location quality and frequency derived from standard ARGOS PTTs to Fastloc GPS locations acquired from 11 northern elephant seals, 5 California and 5 Galapagos sea lions and 1 Cape and 3 Australian fur seals. Our results indicate that GPS technology will greatly enhance our ability to understand the movement patterns of marine vertebrates and the in-situ oceanographic data they collect.

  11. Reval Hotel Lietuva / Argo Vaikla

    Index Scriptorium Estoniae

    Vaikla, Argo, 1966-

    2004-01-01

    Vilniuse hotelli "Lietuva" renoveerimine. Arhitektuurne renoveerimisprojekt: Aare Saks, Nils Palm (SWECO FFNS Arkitekter AB, Rootsi), Rolandas Palekas (UAB Viltekta). Sisekujundus: Katrin ja Argo Vaikla, Liis Lindvere, Peeter Loo (Vaikla Disain AS). Ehitaja: Merko Statyba UAB. Projekt 2002, valmis 2003. I korruse plaan, välisvaade, 4 sisevaadet

  12. ARGOS PHWR 380

    International Nuclear Information System (INIS)

    This paper introduces the design of a nuclear power plant of 380 MWe, equipped with a preassure-vessel heavy-water reactor. An explanation is given of the technical, economical and financial factors that led to the design of this medium sized nuclear power plant, which is compatible with the latest advances in the field of nuclear safety. (Author)

  13. ARGOS laser system mechanical design

    Science.gov (United States)

    Deysenroth, M.; Honsberg, M.; Gemperlein, H.; Ziegleder, J.; Raab, W.; Rabien, S.; Barl, L.; Gässler, W.; Borelli, J. L.

    2014-07-01

    ARGOS, a multi-star adaptive optics system is designed for the wide-field imager and multi-object spectrograph LUCI on the LBT (Large Binocular Telescope). Based on Rayleigh scattering the laser constellation images 3 artificial stars (at 532 nm) per each of the 2 eyes of the LBT, focused at a height of 12 km (Ground Layer Adaptive Optics). The stars are nominally positioned on a circle 2' in radius, but each star can be moved by up to 0.5' in any direction. For all of these needs are following main subsystems necessary: 1. A laser system with its 3 Lasers (Nd:YAG ~18W each) for delivering strong collimated light as for LGS indispensable. 2. The Launch system to project 3 beams per main mirror as a 40 cm telescope to the sky. 3. The Wave Front Sensor with a dichroic mirror. 4. The dichroic mirror unit to grab and interpret the data. 5. A Calibration Unit to adjust the system independently also during day time. 6. Racks + platforms for the WFS units. 7. Platforms and ladders for a secure access. This paper should mainly demonstrate how the ARGOS Laser System is configured and designed to support all other systems.

  14. Argo packing friction research update

    International Nuclear Information System (INIS)

    This paper focuses on the issue of valve packing friction and its affect on the operability of motor- and air-operated valves (MOVs and AOVs). At this time, most nuclear power plants are required to perform postmaintenance testing following a packing adjustment or replacement. In many cases, the friction generated by the packing does not impact the operability window of a valve. However, to date there has not been a concerted effort to substantiate this claim. To quantify the effects of packing friction, it has become necessary to develop a formula to predict the friction effects accurately. This formula provides a much more accurate method of predicting packing friction than previously used factors based strictly on stem diameter. Over the past 5 years, Argo Packing Company has been developing and testing improved graphite packing systems at research facilities, such as AECL Chalk River and Wyle Laboratories. Much of this testing has centered around reducing and predicting friction that is related to packing. In addition, diagnostic testing for Generic Letter 89-10 MOVs and AOVs has created a significant data base. In July 1992 Argo asked several utilities to provide running load data that could be used to quantify packing friction repeatability and predictability. This technical paper provides the basis to predict packing friction, which will improve calculations for thrust requirements for Generic Leter 89-10 and future AOV programs. In addition, having an accurate packing friction formula will improve packing performance when low running loads are identified that would indicate insufficient sealing force

  15. OBIS - ARGOS Satellite Tracking of Animals

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Various species have been tracked using ARGOS PTT trackers since the early 1990's. These include Emperor, King and Adelie pengiuns, Light-mantled Sooty, Grey-headed...

  16. Job submission and management system design and implementation for the ARGO grid

    International Nuclear Information System (INIS)

    The ARGO Grid job submission and management system has been developed on the ARGO grid to provide a convenient and efficient way of submitting ARGO jobs to the grid for ARGO physics users. This paper gives details of the system design and implementation with database technique and wrapper technique. The system has been successfully deployed and tested in the ARGO grid with ARGO reconstruction and simulation applications. (authors)

  17. ARGO-YBJ: Status and Highlights

    CERN Document Server

    Di Sciascio, G

    2012-01-01

    The ARGO-YBJ experiment is in stable data taking since November 2007 at the YangBaJing Cosmic Ray Laboratory (Tibet, P.R. China, 4300 m a.s.l., 606 g/cm$^2$). ARGO-YBJ is facing open problems in Cosmic Ray (CR) physics in different ways. The search for CR sources is carried out by the observation of TeV gamma-ray sources both galactic and extra-galactic. The CR spectrum, composition and anisotropy are measured in a wide energy range (TeV - PeV) thus overlapping for the first time direct measurements. In this paper we summarize the current status of the experiment and describe some of the scientific highlights since 2007.

  18. The Impact of "Bad" Argo Profiles on Ocean Data Assimilation

    Institute of Scientific and Technical Information of China (English)

    YAN Chang-Xiang; ZHU Jiang

    2010-01-01

    Recent studies have found cold biases in a fraction of Argo profiles (hereinafter referred to as bad Array for Real-time Geostrophic Oceanography (Argo) profiles) due to the pressure drifts during 2003 and 2006. These bad Argo profiles have had an important impact on in situ observation-based global ocean heat content estimates. This study investigated the impact of bad Argo profiles on ocean data assimilation results that were based on observations from diverse ocean observation systems, such as in situ profiles (e.g., Argo, expendable bathythermograph (XBT), and Tropical Atmosphere Ocean (TAO), remote-sensing sea surface temperature products and satellite altimetry between 2004 and 2006. Results from this work show that the upper ocean heat content analysis is vulnerable to bad Argo profiles and demonstrate a cooling trend in the studied period despite the multiple independent data types that were assimilated. When the bad Argo profiles were excluded from the assimilation, the decreased heat content disappeared and a warming occurred. Combination of satellite altimetry and mass variation data from gravity satellite demonstrated an increase, which agrees well with the increased heat content. Additionally, when an additional Argo profile quality control procedure was utilized that simply removed the profiles that presented static unstable water columns, the results were very similar to those obtained when the bad Argo profiles were excluded from the assimilation. This indicates that an ocean data assimilation that uses multiple data sources with improved quality control could be less vulnerable to a major observation system failure, such as a bad Argo event.

  19. Implementation in ARGOS of ERMIN and AGRICP

    DEFF Research Database (Denmark)

    Jacobsen, L.H.; Andersson, Kasper Grann; Charnock, T.;

    2010-01-01

    . This paper provides a short overview of the background of the two models and describes the features enabled through their implementation in the ARGOS decision support system. The integration allows calculation of both dose rates and doses in particular areas, and can be used to evaluate the effectiveness......The ERMIN model is a new implement developed to enable estimation of the radiological consequences in inhabited areas of accidents in nuclear installations. Similarly, AGRICP is a model developed to enable estimation of the radiological consequences of contamination of agricultural production areas...

  20. Recent highlights from ARGO-YBJ

    Science.gov (United States)

    Di Sciascio, Di; ARGO-YBJ Collaboration

    2016-05-01

    The ARGO-YBJ experiment has been in stable data taking for more than 5 years at the YangBaJing Cosmic Ray Laboratory (Tibet, P.R. China, 4300 m a.s.L, 606 g/cm2 ). With a duty-cycle of about 87% the detector collected more than 5×1011 events in a wide energy range, from few hundreds GeV up to 10 PeV. A number of open problems in cosmic ray physics has been faced exploiting different analyses. In this talk we summarize the latest physics results obtained in gamma-ray astronomy and in cosmic ray physics.

  1. Experience of the ARGO autonomous vehicle

    Science.gov (United States)

    Bertozzi, Massimo; Broggi, Alberto; Conte, Gianni; Fascioli, Alessandra

    1998-07-01

    This paper presents and discusses the first results obtained by the GOLD (Generic Obstacle and Lane Detection) system as an automatic driver of ARGO. ARGO is a Lancia Thema passenger car equipped with a vision-based system that allows to extract road and environmental information from the acquired scene. By means of stereo vision, obstacles on the road are detected and localized, while the processing of a single monocular image allows to extract the road geometry in front of the vehicle. The generality of the underlying approach allows to detect generic obstacles (without constraints on shape, color, or symmetry) and to detect lane markings even in dark and in strong shadow conditions. The hardware system consists of a PC Pentium 200 Mhz with MMX technology and a frame-grabber board able to acquire 3 b/w images simultaneously; the result of the processing (position of obstacles and geometry of the road) is used to drive an actuator on the steering wheel, while debug information are presented to the user on an on-board monitor and a led-based control panel.

  2. Hotelli Palace**** renoveerimine = Renovation of the hotel Palace**** / Argo Vaikla

    Index Scriptorium Estoniae

    Vaikla, Argo, 1966-

    2015-01-01

    Hotell Palace Tallinnas Vabaduse väljak 3, valminud 2014. Hoone rekonstrueerimisprojekt Reet Valk (AB Reet Valk), sisearhitektid Katrin Vaikla, Argo Vaikla, Mari-Liis Süld, Riin Luuk. 2014. aasta Kultuurkapitali Arhitektuuripreemia kandidaat

  3. Cosmic ray physics with ARGO-YBJ

    CERN Document Server

    ,

    2016-01-01

    The ARGO--YBJ experiment has been in stable data taking for more than five years at the Yangbajing cosmic ray observatory (Tibet, P.R. China, 4300 m a.s.l.). The detector collected about $5\\times10^{11}$ events in a wide energy range from few TeVs up to the PeV region. In this work we summarize the latest results in cosmic ray physics particularly focusing on the cosmic ray energy spectrum. The results of the measurement of the all-particle and proton plus helium energy spectra in the energy region between $10^{12} - 10^{16}$ eV are discussed. A precise measurement of the cosmic ray energy spectrum and composition in this energy region allows a better understanding of the origin of the knee and provides a powerful cross-check among different experimental techniques.

  4. Argos: An Optimized Time-Series Photometer

    Indian Academy of Sciences (India)

    Anjum S. Mukadam; R. E. Nather

    2005-06-01

    We designed a prime focus CCD photometer, Argos, optimized for high speed time-series measurements of blue variables (Nather & Mukadam 2004) for the 2.1 m telescope at McDonald Observatory. Lack of any intervening optics between the primary mirror and the CCD makes the instrument highly efficient.We measure an improvement in sensitivity by a factor of nine over the 3-channel PMT photometers used on the same telescope and for the same exposure time. The CCD frame transfer operation triggered by GPS synchronized pulses serves as an electronic shutter for the photometer. This minimizes the dead time between exposures, but more importantly, allows a precise control of the start and duration of the exposure. We expect the uncertainty in our timing to be less than 100 s.

  5. Text-mining-assisted biocuration workflows in Argo.

    Science.gov (United States)

    Rak, Rafal; Batista-Navarro, Riza Theresa; Rowley, Andrew; Carter, Jacob; Ananiadou, Sophia

    2014-01-01

    Biocuration activities have been broadly categorized into the selection of relevant documents, the annotation of biological concepts of interest and identification of interactions between the concepts. Text mining has been shown to have a potential to significantly reduce the effort of biocurators in all the three activities, and various semi-automatic methodologies have been integrated into curation pipelines to support them. We investigate the suitability of Argo, a workbench for building text-mining solutions with the use of a rich graphical user interface, for the process of biocuration. Central to Argo are customizable workflows that users compose by arranging available elementary analytics to form task-specific processing units. A built-in manual annotation editor is the single most used biocuration tool of the workbench, as it allows users to create annotations directly in text, as well as modify or delete annotations created by automatic processing components. Apart from syntactic and semantic analytics, the ever-growing library of components includes several data readers and consumers that support well-established as well as emerging data interchange formats such as XMI, RDF and BioC, which facilitate the interoperability of Argo with other platforms or resources. To validate the suitability of Argo for curation activities, we participated in the BioCreative IV challenge whose purpose was to evaluate Web-based systems addressing user-defined biocuration tasks. Argo proved to have the edge over other systems in terms of flexibility of defining biocuration tasks. As expected, the versatility of the workbench inevitably lengthened the time the curators spent on learning the system before taking on the task, which may have affected the usability of Argo. The participation in the challenge gave us an opportunity to gather valuable feedback and identify areas of improvement, some of which have already been introduced. Database URL: http://argo.nactem.ac.uk.

  6. A statistical method for correcting salinity observations from autonomous profiling floats: An ARGO perspective

    Digital Repository Service at National Institute of Oceanography (India)

    Durand, F.; Reverdin, G.

    The Profiling Autonomous Lagrangian Circulation Explorer (PALACE) float is used to implement the Array for Real-Time Geostrophic Oceanography (ARGO). This study presents a statistical approach to correct salinity measurement errors of an ARGO...

  7. ARGO-YBJ data acquisition system

    Energy Technology Data Exchange (ETDEWEB)

    Aloisio, A. [Dipartimento di Fisica, Universita ' Federico II' and INFN, Naples (Italy); Branchini, P. [Dipartimento di Fisica, Universita Roma Tre and INFN, Rome (Italy); Budano, A. [Dipartimento di Fisica, Universita Roma Tre and INFN, Rome (Italy); Catalanotti, S. [Dipartimento di Fisica, Universita ' Federico II' and INFN, Naples (Italy); Creti, P. [Dipartimento di Ingegneria, Universita degli Studi di Lecce and INFN, Lecce (Italy); Galeazzi, F. [Dipartimento di Fisica, Universita Roma Tre and INFN, Rome (Italy); Marsella, G. [Dipartimento di Ingegneria, Universita degli Studi di Lecce and INFN, Lecce (Italy); Mastroianni, S. [Dipartimento di Fisica, Universita ' Federico II' and INFN, Naples (Italy)]. E-mail: Stefano.Mastroianni@na.infn.it; Ruggieri, F. [Dipartimento di Fisica, Universita Roma Tre and INFN, Rome (Italy); Stanescu, C. [Dipartimento di Fisica, Universita Roma Tre and INFN, Rome (Italy)

    2006-12-01

    The ARGO-YBJ experiment is reaching its final design configuration. An array of single layer Resistive Plate Counters (RPCs) covering an area of {approx}5800m{sup 2} will collect a huge amount of data. The throughput required from the final detector strongly depends on the trigger rate. The DAQ system must be able to sustain a data transfer rate estimated to be the order of 15MB/s and a high peak of data flow. Data are read out using a typical front-end acquisition chain built around a custom bus. Specialized electronics have been designed and efficient software had to be written to perform this task. Data are then sent to the on-line farm through a switch exploiting gigabit-ethernet protocol. In this paper we will describe the design of the DAQ system, the software which deals with data collection and network sending and the performances. The architecture of the on-line farm is also described together with the monitoring system.

  8. Implementation of SLODAR atmospheric turbulence profiling to the ARGOS system

    Science.gov (United States)

    Mazzoni, Tommaso; Busoni, Lorenzo; Bonaglia, Marco; Esposito, Simone

    2014-08-01

    ARGOS is the Ground Layer Adaptive Optics system of the Large Binocular Telescope, it uses three Laser Guide Stars at 12 km altitude, generated by Rayleigh backscattered light of pulsed Nd:YAG lasers at 532nm. The wavefront distortion in the Ground Layer is measured by three Shack-Hartmann WFS, sampling with 15×15 subaperture the three LGS arranged on a single CCD with 8×8px per square subaperture. The SLOpe Detection And Ranging (SLODAR) is a method used to measure the turbulence profiles. Cross correlation of wavefronts gradient from multiple stars is used to estimate the relative strengths of turbulent layers at different altitudes. In the ARGOS case the LGS are arranged on a triangle inscribed in a 2 arcmin radius circle, so we expect an effective slopes correlation up to 5km altitude. We present here the results of a study aimed to implement the SLODAR method on ARGOS performed with the idl-based simulation code used to characterize the ARGOS performance. Simulation implements the atmospheric turbulence on different layers with variable strength, altitude and wind speed. The algorithm performance are evaluated comparing the input turbulence with the cross-correlation of the SH slopes acquired in open loop.

  9. Validation of argo data in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Pankajakshan, T.; Muraleedharan, P.M.; Gopalakrishna, V.V.; Reddy, G.V.; Ratnakaran, L.; Revichandran, C.; Murty, V.S.N.

    in the dimension of the conductivity cell due to fouling. Sensor manufacturers have improved the anti-fouling measures with biocide rings and anti-fouling paint (Tri- Butyl Tin Oxide, TBTO). However, since the Argo floats remain in the waters for years together...

  10. Maize and Arabidopsis ARGOS Proteins Interact with Ethylene Receptor Signaling Complex, Supporting a Regulatory Role for ARGOS in Ethylene Signal Transduction[OPEN

    Science.gov (United States)

    Shi, Jinrui; Wang, Hongyu; Habben, Jeffrey E.

    2016-01-01

    The phytohormone ethylene regulates plant growth and development as well as plant response to environmental cues. ARGOS genes reduce plant sensitivity to ethylene when overexpressed in transgenic Arabidopsis (Arabidopsis thaliana) and maize (Zea mays). A previous genetic study suggested that the endoplasmic reticulum and Golgi-localized maize ARGOS1 targets the ethylene signal transduction components at or upstream of CONSTITUTIVE TRIPLE RESPONSE1, but the mechanism of ARGOS modulating ethylene signaling is unknown. Here, we demonstrate in Arabidopsis that ZmARGOS1, as well as the Arabidopsis ARGOS homolog ORGAN SIZE RELATED1, physically interacts with Arabidopsis REVERSION-TO-ETHYLENE SENSITIVITY1 (RTE1), an ethylene receptor interacting protein that regulates the activity of ETHYLENE RESPONSE1. The protein-protein interaction was also detected with the yeast split-ubiquitin two-hybrid system. Using the same yeast assay, we found that maize RTE1 homolog REVERSION-TO-ETHYLENE SENSITIVITY1 LIKE4 (ZmRTL4) and ZmRTL2 also interact with maize and Arabidopsis ARGOS proteins. Like AtRTE1 in Arabidopsis, ZmRTL4 and ZmRTL2 reduce ethylene responses when overexpressed in maize, indicating a similar mechanism for ARGOS regulating ethylene signaling in maize. A polypeptide fragment derived from ZmARGOS8, consisting of a Pro-rich motif flanked by two transmembrane helices that are conserved among members of the ARGOS family, can interact with AtRTE1 and maize RTL proteins in Arabidopsis. The conserved domain is necessary and sufficient to reduce ethylene sensitivity in Arabidopsis and maize. Overall, these results suggest a physical association between ARGOS and the ethylene receptor signaling complex via AtRTE1 and maize RTL proteins, supporting a role for ARGOS in regulating ethylene perception and the early steps of signal transduction in Arabidopsis and maize. PMID:27268962

  11. Validation of salinity data from ARGO floats: Comparison between the older ARGO floats and that of later deployments

    Digital Repository Service at National Institute of Oceanography (India)

    Youn, Y.-H.; Lee, H.; Chang, Y.-S.; Pankajakshan, T.

    time different of less than 100 km are considered for the match-up data sets. For analysis of the salinity drift under the stable water mass, observations of the floats from deepest water masses have been used. From the cross-check of ARGO floats...

  12. Drift in salinity data from Argo profiling floats in the Sea of Japan

    Digital Repository Service at National Institute of Oceanography (India)

    Pankajakshan, T.; Bajish, C.C.; Behera, S.; Gopalakrishna, V.V.

    for constructive sug- gestionsthat helpedtoimprovethequalityof thepaper. REFERENCES Argo, 2010: Report of 11th Argo Data Management Meeting, version1.2.,124pp.[Availableonlineathttp://www.argodatamgt. org/Data-Mgt-Team/Meetings-and-reports.] Bryden, L. H., E. L. Mc... inopenoceanregions, in additiontoconfinedbasins suchas SOJ, SALD was applied successfully todetect salinity error in Argo data from the subtropical North Pacific (SNP). 1. Introduction Salinity plays a major role in ocean circulation to af- fect regional and global...

  13. Physics Results from the Argo-YBJ Experiment

    CERN Document Server

    Di Sciascio, G

    2008-01-01

    The ARGO-YBJ experiment has been in stable data taking since November 2007 at the YangBaJing Cosmic Ray Laboratory (Tibet, P.R. China, 4300 m a.s.l.). In this paper we report a few selected results in Gamma-Ray Astronomy (Crab Nebula and Mrk421 observations, search for high energy tails of GRBs) and Cosmic Ray Physics (Moon and Sun shadow observations, proton-air cross section and antiproton/proton preliminary measurements).

  14. Gamma-Ray Astronomy with ARGO-YBJ

    CERN Document Server

    Di Sciascio, G

    2011-01-01

    ARGO-YBJ is a full coverage air shower array located at the YangBaJing Cosmic Ray Laboratory (Tibet, P.R. China, 4300 m a.s.l., 606 g/cm^2) recording data with a duty cycle $\\geq$85% and an energy threshold of a few hundred GeV. In this paper the latest results in Gamma-Ray Astronomy are summarized.

  15. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2010-04-01 for the Global Argo Data Repository, date ranged from 2005-10-23 to 2010-04-07 (NODC Accession 0062992)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  16. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2003-05-18 for the Global Argo Data Repository, date ranged from 2001-11-28 to 2003-05-24 (NODC Accession 0001037)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  17. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-04-30 for the Global Argo Data Repository, date ranged from 2002-03-08 to 2006-05-06 (NODC Accession 0002664)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  18. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2005-11-06 for the Global Argo Data Repository, date ranged from 2001-10-13 to 2005-11-12 (NODC Accession 0002455)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  19. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2009-07-16 for the Global Argo Data Repository, date ranged from 2002-03-01 2009-07-22 (NODC Accession 0056186)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  20. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2003-09-07 for the Global Argo Data Repository, date ranged from 2003-04-28 to 2003-09-13 (NODC Accession 0001166)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  1. Temperature and salinity profile data from globally distributed Argo profiling floats for the month of November 2006 for the Global Argo Data Repository, 1996-01-05 to 2006-12-01 (NODC Accession 0011212)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  2. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-12-10 for the Global Argo Data Repository, date ranged from 2002-12-08 to 2006-12-16 (NODC Accession 0011574)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  3. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-09-03 for the Global Argo Data Repository, date ranged from 1998-05-25 to 2006-09-09 (NODC Accession 0002834)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  4. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2003-06-08 for the Global Argo Data Repository, date ranged from 2003-05-26 to 2003-06-14 (NODC Accession 0001054)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  5. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2005-06-19 for the Global Argo Data Repository, date ranged from 2000-06-18 to 2005-06-25 (NODC Accession 0002257)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  6. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2009-03-12 for the Global Argo Data Repository, date ranged from 1998-12-08 to 2009-03-18 (NODC Accession 0002061)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  7. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2007-03-04 for the Global Argo Data Repository, date ranged from 2001-09-30 to 2007-03-10 (NODC Accession 0013875)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  8. Temperature and salinity profile data from globally distributed Argo profiling floats for the month of January 2007 for the Global Argo Data Repository, 1996-01-05 to 2007-01-31 (NODC Accession 0013024)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  9. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2003-07-27 for the Global Argo Data Repository, date ranged from 2001-10-27 to 2003-08-02 (NODC Accession 0001117)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  10. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2009-08-20 for the Global Argo Data Repository, date ranged from 2001-09-30 to 2009-08-26 (NODC Accession 0057201)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  11. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-12-03 for the Global Argo Data Repository, date ranged from 1999-10-25 to 2006-12-09 (NODC Accession 0011263)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  12. Temperature and salinity profile data from globally distributed Argo profiling floats for the month of June 2007 for the Global Argo Data Repository, 1996-01-05 to 2007-07-01 (NODC Accession 0020937)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  13. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2007-02-11 for the Global Argo Data Repository, date ranged from 2002-10-29 to 2007-02-17 (NODC Accession 0013200)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  14. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2009-12-24 for the Global Argo Data Repository, date ranged from 2002-02-15 to 2009-12-30 (NODC Accession 0060860)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  15. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2009-03-26 for the Global Argo Data Repository, date ranged from 1999-10-02 to 2009-04-01 (NODC Accession 0052543)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  16. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2007-10-14 for the Global Argo Data Repository, date ranged from 1995-09-07 to 2007-10-20 (NODC Accession 0035978)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR)as the long-term archive for the International Global Argo Project...

  17. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2003-06-01 for the Global Argo Data Repository, date ranged from 2001-10-18 to 2003-06-07 (NODC Accession 0001051)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  18. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2009-12-17 for the Global Argo Data Repository, date ranged from 2002-02-05 to 2009-12-23 (NODC Accession 0060676)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  19. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2008-01-06 for the Global Argo Data Repository, date ranged from 2002-12-13 to 2008-01-12 (NODC Accession 0038182)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR)as the long-term archive for the International Global Argo Project...

  20. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2003-10-19 for the Global Argo Data Repository, date ranged from 2003-06-08 to 2003-10-25 (NODC Accession 0001210)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  1. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2007-05-20 for the Global Argo Data Repository, date ranged from 2003-07-29 to 2007-05-26 (NODC Accession 0019205)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  2. Temperature and salinity profile data from globally distributed Argo profiling floats for the month of October 2003 for the Global Argo Data Repository, 1996-01-05 to 2003-10-31 (NODC Accession 0001217)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  3. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2007-07-08 for the Global Argo Data Repository, date ranged from 2002-03-30 to 2007-07-14 (NODC Accession 0029182)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  4. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-07-02 for the Global Argo Data Repository, date ranged from 2001-07-30 to 2006-07-08 (NODC Accession 0002745)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  5. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2005-01-09 for the Global Argo Data Repository, 2000-03-01 to 2005-01-15 (NODC Accession 0001981)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  6. Temperature and salinity profile data from globally distributed Argo profiling floats for the month of April 2006 for the Global Argo Data Repository, 1996-01-05 to 2006-04-30 (NODC Accession 0002655)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  7. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2010-07-08 for the Global Argo Data Repository, date ranged from 2005-01-19 to 2010-07-14 (NODC Accession 0065728)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository(GADR as the long-term archive for the International Global Argo Project...

  8. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-11-19 for the Global Argo Data Repository, date ranged from 2001-01-21 to 2006-11-25 (NODC Accession 0011021)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  9. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2008-05-29 for the Global Argo Data Repository, date ranged from 2006-03-01 to 2008-06-04 (NODC Accession 0042701)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR)as the long-term archive for the International Global Argo Project...

  10. Temperature and salinity profile data from globally distributed Argo profiling floats for the month of June 2005 for the Global Argo Data Repository, 1996-01-05 to 2005-06-30 (NODC Accession 0002261)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  11. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2005-02-13 for the Global Argo Data Repository, 2001-04-10 to 2005-02-19 (NODC Accession 0002035)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  12. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2009-10-29 for the Global Argo Data Repository, date ranged from 2001-09-21 to 2009-11-04 (NODC Accession 0059252)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  13. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-03-05 for the Global Argo Data Repository, date ranged from 2002-04-02 to 2006-03-11 (NODC Accession 0002598)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  14. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2009-04-30 for the Global Argo Data Repository, date ranged from 2004-03-06 to 2009-05-06 (NODC Accession 0053667)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  15. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-01-08 for the Global Argo Data Repository, date ranged from 2001-06-14 to 2006-01-14 (NODC Accession 0002499)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  16. Temperature and salinity profile data from globally distributed Argo profiling floats for the month of May 2007 for the Global Argo Data Repository, 1996-01-05 to 2007-06-01 (NODC Accession 0019350)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  17. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2010-02-18 for the Global Argo Data Repository, date ranged from 2001-09-30 to 2010-02-24 (NODC Accession 0062336)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  18. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2010-05-06 for the Global Argo Data Repository, date ranged from 2001-01-21 to 2010-05-12 (NODC Accession 0064275)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository(GADR as the long-term archive for the International Global Argo Project...

  19. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2009-04-23 for the Global Argo Data Repository, date ranged from 2001-11-07 to 2009-04-29 (NODC Accession 0053406)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  20. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2009-02-19 for the Global Argo Data Repository, date ranged from 1999-07-16 to 2009-02-25 (NODC Accession 0051511)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  1. Temperature and salinity profile data from globally distributed Argo profiling floats for the month of February 2007 for the Global Argo Data Repository, 1996-01-05 to 2007-02-28 (NODC Accession 0013628)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  2. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2003-10-05 for the Global Argo Data Repository, date ranged from 2001-10-13 to 2003-10-11 (NODC Accession 0001198)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  3. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2010-01-14 for the Global Argo Data Repository, date ranged from 2003-02-20 to 2010-01-20 (NODC Accession 0061422)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  4. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2010-03-04 for the Global Argo Data Repository, date ranged from 2002-10-05 to 2010-03-10 (NODC Accession 0062620)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  5. Temperature and salinity profile data from globally distributed Argo profiling floats for the month of October 2007 for the Global Argo Data Repository, 1995-09-07 to 2007-10-31 (NODC Accession 0036822)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  6. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-02-26 for the Global Argo Data Repository, date ranged from 2001-12-12 to 2006-03-04 (NODC Accession 0002591)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  7. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2004-09-12 for the Global Argo Data Repository, date ranged from 2004-01-12 to 2004-09-18 (NODC Accession 0001719)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  8. Temperature and Salinity profile data from globally distributed Argo profiling floats for the week of 2008-06-05 for the Global Argo Data Repository, date ranged from 2006-10-08 to 2008-06-11 (NODC Accession 0042829)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR)as the long-term archive for the International Global Argo Project...

  9. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2007-04-08 for the Global Argo Data Repository, date ranged from 2005-02-25 to 2007-04-14 (NODC Accession 0014769)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  10. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2009-08-13 for the Global Argo Data Repository, date ranged from 2002-03-12 to 2009-08-19 (NODC Accession 0057012)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  11. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2003-04-20 for the Global Argo Data Repository, date ranged from 2003-03-10 to 2003-04-26 (NODC Accession 0001001)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  12. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2004-07-18 for the Global Argo Data Repository, date ranged from 2003-09-26 to 2004-07-24 (NODC Accession 0001640)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  13. Temperature and Salinity profile data from globally distributed Argo profiling floats for the week of 2008-11-20 for the Global Argo Data Repository, date ranged from 2000-02-01 to 2008-11-26 (NODC Accession 0048970)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR as the long-term archive for the International Global Argo Project...

  14. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2008-02-24 for the Global Argo Data Repository, date ranged from 1979-05-15 to 2008-03-01 (NODC Accession 0039348)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR)as the long-term archive for the International Global Argo Project...

  15. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2004-05-02 for the Global Argo Data Repository, date ranged from 2000-11-22 to 2004-05-08 (NODC Accession 0001453)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  16. Temperature and salinity profile data from globally distributed Argo profiling floats for the month of February 2005 for the Global Argo Data Repository, 1996-01-05 to 2005-02-28 (NODC Accession 0002048)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  17. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2009-04-16 for the Global Argo Data Repository, date ranged from 2004-07-07 to 2009-04-22 (NODC Accession 0053405)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  18. Temperature and Salinity profile data from globally distributed Argo profiling floats for the week of 2008- 10-16 for the Global Argo Data Repository, date ranged from 1998-05-22 to 2008-10-22 (NODC Accession 0046744)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR)as the long-term archive for the International Global Argo Project...

  19. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2010-01-07 for the Global Argo Data Repository, date ranged from 2003-09-15 to 2010-01-13 (NODC Accession 0061249)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  20. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-08-13 for the Global Argo Data Repository, date ranged from 2000-10-31 to 2006-08-19 (NODC Accession 0002802)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  1. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2004-11-21 for the Global Argo Data Repository, date ranged from 2002-08-30 to 2004-11-27 (NODC Accession 0001911)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  2. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2007-11-11 for the Global Argo Data Repository, date ranged from 2002-01-11 to 2007-11-17 (NODC Accession 0036655)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR)as the long-term archive for the International Global Argo Project...

  3. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2009-05-28 for the Global Argo Data Repository, date ranged from 2002-02-05 to 2009-06-02 (NODC Accession 0054265)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  4. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2009-12-31 for the Global Argo Data Repository, date ranged from 2006-03-28 to 2010-01-06 (NODC Accession 0061041)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  5. Temperature and Salinity profile data from globally distributed Argo profiling floats for the week of 2008-07-10 for the Global Argo Data Repository, date ranged from 2007-12-18 to 2008-07-17 (NODC Accession 0043460)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR)as the long-term archive for the International Global Argo Project...

  6. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-04-09 for the Global Argo Data Repository, date ranged from 1998-02-23 to 2006-04-15 (NODC Accession 0002633)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  7. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2003-12-14 for the Global Argo Data Repository, date ranged from 2002-05-12 to 2003-12-20 (NODC Accession 0001272)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  8. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-01-29 for the Global Argo Data Repository, date ranged from 2001-06-03 to 2006-01-31 (NODC Accession 0002527)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  9. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-06-18 for the Global Argo Data Repository, date ranged from 2000-04-04 to 2006-06-24 (NODC Accession 0002726)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  10. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-02-05 for the Global Argo Data Repository, date ranged from 2003-10-22 to 2006-02-11 (NODC Accession 0002572)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  11. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2003-10-26 for the Global Argo Data Repository, date ranged from 2003-03-12 to 2003-11-01 (NODC Accession 0001216)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  12. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2003-07-13 for the Global Argo Data Repository, date ranged from 2002-02-17 to 2003-07-19 (NODC Accession 0001103)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  13. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2007-11-25 for the Global Argo Data Repository, date ranged from 2000-05-10 to 2007-12-01 (NODC Accession 0036984)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR)as the long-term archive for the International Global Argo Project...

  14. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2010-05-13 for the Global Argo Data Repository, date ranged from 2001-01-21 to 2010-05-19 (NODC Accession 0064383)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository(GADR as the long-term archive for the International Global Argo Project...

  15. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2006-10-15 for the Global Argo Data Repository, date ranged from 2006-03-26 to 2006-10-21 (NODC Accession 0010542)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  16. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2004-04-04 for the Global Argo Data Repository, date ranged from 2000-11-22 to 2004-04-10 (NODC Accession 0001422)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  17. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2005-10-02 for the Global Argo Data Repository, date ranged from 2000-12-08 to 2005-10-08 (NODC Accession 0002398)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  18. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2010-06-10 for the Global Argo Data Repository, date ranged from 2004-06-08 to 2010-06-16 (NODC Accession 0065228)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository(GADR as the long-term archive for the International Global Argo Project...

  19. Temperature and salinity profile data from globally distributed Argo profiling floats for the week of 2004-03-28 for the Global Argo Data Repository, date ranged from 2004-02-29 to 2004-04-03 (NODC Accession 0001411)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR) as the long-term archive for the International Global Argo...

  20. Temperature and Salinity profile data from globally distributed Argo profiling floats for the week of 2008-10-02 for the Global Argo Data Repository, date ranged from 2002-01-19 to 2008-10-08 (NODC Accession 0046221)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Oceanographic Data Center (NODC) operates the Global Argo Data Repository (GADR)as the long-term archive for the International Global Argo Project...

  1. Analyses of altimetry errors using Argo and GRACE data

    Science.gov (United States)

    Legeais, Jean-François; Prandi, Pierre; Guinehut, Stéphanie

    2016-05-01

    This study presents the evaluation of the performances of satellite altimeter missions by comparing the altimeter sea surface heights with in situ dynamic heights derived from vertical temperature and salinity profiles measured by Argo floats. The two objectives of this approach are the detection of altimeter drift and the estimation of the impact of new altimeter standards that requires an independent reference. This external assessment method contributes to altimeter calibration-validation analyses that cover a wide range of activities. Among them, several examples are given to illustrate the usefulness of this approach, separating the analyses of the long-term evolution of the mean sea level and its variability, at global and regional scales and results obtained via relative and absolute comparisons. The latter requires the use of the ocean mass contribution to the sea level derived from Gravity Recovery and Climate Experiment (GRACE) measurements. Our analyses cover the estimation of the global mean sea level trend, the validation of multi-missions altimeter products as well as the assessment of orbit solutions.Even if this approach contributes to the altimeter quality assessment, the differences between two versions of altimeter standards are getting smaller and smaller and it is thus more difficult to detect their impact. It is therefore essential to characterize the errors of the method, which is illustrated with the results of sensitivity analyses to different parameters. This includes the format of the altimeter data, the method of collocation, the temporal reference period and the processing of the ocean mass solutions from GRACE. We also assess the impact of the temporal and spatial sampling of Argo floats, the choice of the reference depth of the in situ profiles and the importance of the deep steric contribution. These analyses provide an estimation of the robustness of the method and the characterization of associated errors. The results also allow us

  2. Application of Argo-derived background diapycnal mixing in HYCOM

    Science.gov (United States)

    Deng, Zengan; Yu, Ting

    2014-09-01

    Internal wave-induced background diapycnal mixing (DM) in the upper 2000 m of the global ocean, which primarily depends on the local inertial frequency, is calculated based on Argo observations using the newly published Thermodynamic Equation of Seawater-2010 (IOC, SCOR and IAPSO, 2010). This spatially dependent background DM agrees well with previous theoretical and observational mixing estimates. More importantly, the DM data are gridded, which renders the data suitable for modeling applications. The implementation of these data in the HYbrid Coordinate Ocean Model (HYCOM) demonstrates the potential for their application in numerical ocean models. Three numerical experiments that are specifically designed with different DM settings reveal that the meridional overturning circulation (MOC), temperature and salinity in the Atlantic change substantially when the constant background DM is replaced with Argo-derived mixing. Tropical and high-latitude regions that are considered important for global climate are identified as the areas that are most sensitive to the magnitude of the background DM. Compared with constant background DM, the enhanced mid-latitude DM most likely contributes substantially to the MOC transport. Thus, although room remains for improvement, the spatially varying DM derived in the present study may facilitate global circulation and climate modeling.

  3. Multifrequency seismic detectability of seasonal thermoclines assessed from ARGO data

    Science.gov (United States)

    Ker, S.; Le Gonidec, Y.; Marié, L.

    2016-08-01

    Seismic oceanography is a developing research topic where new acoustic methods allow high-resolution teledetection of the thermohaline structure of the ocean. First implementations to study the Ocean Surface Boundary Layer have recently been achieved but remain very challenging due to the weakness and shallowness of such seismic reflectors. In this article, we develop a multifrequency seismic analysis of hydrographic data sets collected in a seasonally stratified midlatitude shelf by ARGO network floats to assess the detectability issue of shallow thermoclines. This analysis, for which sensitivity to the data reduction scheme used by ARGO floats for the transmission of the profiles is discussed, allows characterizing both the depth location and the frequency dependency of the dominant reflective feature of such complex structures. This approach provides the first statistical distribution of the range of variability of the frequency-dependent seismic reflection amplitude of the midlatitude seasonal thermoclines. We introduce a new parameter to quantify the overall capability of a multichannel seismic setup, including the source strength, the fold, and the ambient noise level, to detect shallow thermoclines. Seismic source signals are approximated by Ricker wavelets, providing quantitative guidelines to help in the design of seismic experiments targeting such oceanic reflectors. For shallow midlatitude seasonal thermoclines, we show that the detectability is optimal for seismic peak frequencies between 200 and 400 Hz: this means that airgun and Sparker sources are not well suited and that significant improvements of source devices will be necessary before seismic imaging of OSBL structures can be reliably attempted.

  4. How essential are Argo observations to constrain a global ocean data assimilation system?

    Science.gov (United States)

    Turpin, V.; Remy, E.; Le Traon, P. Y.

    2016-02-01

    Observing system experiments (OSEs) are carried out over a 1-year period to quantify the impact of Argo observations on the Mercator Ocean 0.25° global ocean analysis and forecasting system. The reference simulation assimilates sea surface temperature (SST), SSALTO/DUACS (Segment Sol multi-missions dALTimetrie, d'orbitographie et de localisation précise/Data unification and Altimeter combination system) altimeter data and Argo and other in situ observations from the Coriolis data center. Two other simulations are carried out where all Argo and half of the Argo data are withheld. Assimilating Argo observations has a significant impact on analyzed and forecast temperature and salinity fields at different depths. Without Argo data assimilation, large errors occur in analyzed fields as estimated from the differences when compared with in situ observations. For example, in the 0-300 m layer RMS (root mean square) differences between analyzed fields and observations reach 0.25 psu and 1.25 °C in the western boundary currents and 0.1 psu and 0.75 °C in the open ocean. The impact of the Argo data in reducing observation-model forecast differences is also significant from the surface down to a depth of 2000 m. Differences between in situ observations and forecast fields are thus reduced by 20 % in the upper layers and by up to 40 % at a depth of 2000 m when Argo data are assimilated. At depth, the most impacted regions in the global ocean are the Mediterranean outflow, the Gulf Stream region and the Labrador Sea. A significant degradation can be observed when only half of the data are assimilated. Therefore, Argo observations matter to constrain the model solution, even for an eddy-permitting model configuration. The impact of the Argo floats' data assimilation on other model variables is briefly assessed: the improvement of the fit to Argo profiles do not lead globally to unphysical corrections on the sea surface temperature and sea surface height. The main conclusion

  5. A comparison of Argo nominal surface and near-surface temperature for validation of AMSR-E SST

    Science.gov (United States)

    Liu, Zenghong; Chen, Xingrong; Sun, Chaohui; Wu, Xiaofen; Lu, Shaolei

    2016-06-01

    Satellite SST (sea surface temperature) from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) is compared with in situ temperature observations from Argo profiling floats over the global oceans to evaluate the advantages of Argo NST (near-surface temperature: water temperature less than 1 m from the surface). By comparing Argo nominal surface temperature (~5 m) with its NST, a diurnal cycle caused by daytime warming and nighttime cooling was found, along with a maximum warming of 0.08±0.36°C during 14:00-15:00 local time. Further comparisons between Argo 5-m temperature/Argo NST and AMSR-E SST retrievals related to wind speed, columnar water vapor, and columnar cloud water indicate warming biases at low wind speed (28 mm during daytime. The warming tendency is more remarkable for AMSR-E SST/Argo 5-m temperature compared with AMSR-E SST/Argo NST, owing to the effect of diurnal warming. This effect of diurnal warming events should be excluded before validation for microwave SST retrievals. Both AMSR-E nighttime SST/Argo 5-m temperature and nighttime SST/Argo NST show generally good agreement, independent of wind speed and columnar water vapor. From our analysis, Argo NST data demonstrated their advantages for validation of satellite-retrieved SST.

  6. Accurate estimation of influenza epidemics using Google search data via ARGO.

    Science.gov (United States)

    Yang, Shihao; Santillana, Mauricio; Kou, S C

    2015-11-24

    Accurate real-time tracking of influenza outbreaks helps public health officials make timely and meaningful decisions that could save lives. We propose an influenza tracking model, ARGO (AutoRegression with GOogle search data), that uses publicly available online search data. In addition to having a rigorous statistical foundation, ARGO outperforms all previously available Google-search-based tracking models, including the latest version of Google Flu Trends, even though it uses only low-quality search data as input from publicly available Google Trends and Google Correlate websites. ARGO not only incorporates the seasonality in influenza epidemics but also captures changes in people's online search behavior over time. ARGO is also flexible, self-correcting, robust, and scalable, making it a potentially powerful tool that can be used for real-time tracking of other social events at multiple temporal and spatial resolutions.

  7. Quality Control of ARGO Data Based on Climatological T-S Models

    Institute of Scientific and Technical Information of China (English)

    纪风颖; 林绍花

    2004-01-01

    By implementing the ARGO program, a large number of T-S profiles can be observed in the world ocean. However, it is very difficult to examine changes of the sensitivity of the sensors equipped at the ARGO floats, because it is difficult to understand their condition in the sea and the reliability of the data. Quality control must be done in order to avoid the wrong conclusion deduced from the wrong data.One of the realistic methods for quality control of the ARGO data is the comparison with the local climatology. High quality climatological T-S models in northwest Pacific have been built based on the Nansen bottle data and CTD data for the quality control in NMDIS. The models are used to check the ARGO data in this area and have got good result.

  8. Using ARGO, GRACE and altimetry to assess the quasi stationary circulation in the North Atlantic

    OpenAIRE

    Richter, Falk; Sidorenko, Dmitry; Danilov, Sergey; Schröter, Jens

    2009-01-01

    The data available from Argo profiling buoys and satellite altimetry are combined into Inverse Finite Element Ocean model (IFEOM) for each of the years 2005 and 2006. The model solves for temperature and salinity fields that are close to measurements, respects quasi-stationary dynamical balances, and simultaneously produces estimates of the circulation. Several experiments have been performed to reconstruct the interannual variability. The assimilation of Argo data alone produces qualitative ...

  9. ARGO-YBJ:丰富多彩的宇宙线观测%ARGO-YBJ: Fruitful Cosmic Ray Observations

    Institute of Scientific and Technical Information of China (English)

    曹臻

    2012-01-01

    Being smoothly operated for 5 years, the ARGO-YBJ experiment collected 0.4 trillion cosmic ray event samples. Many scientific goals have been achieved based on the very important data base. Here in this article, we summarize all major contributions to cosmic ray related researches, including conventional measurements such as cosmic ray energy spectrum, composition and anisotropy. The researches also cover many non-traditional topics such as the monitoring of solar activity using Galactic cosmic rays, forecasting large geomagnetic storms induced by huge flares of the sun, exploring the correlation between thunderstorms and extensives air shower of cosmic rays and so forth. With the progresses of the future experiment LHAASO, all researches reported in this paper will be greatly enhanced using the most sensitive new generation apparatus. Breakthrough may be expected in some of the topics.

  10. What can ARGO's tell us on the processes in Baltic Sea?

    Science.gov (United States)

    Roiha, Petra; Siiriä, Simo-Matti; Nummelin, Aleksi; Aro, Eemeli; Purokoski, Tero

    2014-05-01

    Finnish Meteorological Institute has been testing ARGO floats in the Baltic Sea as a mean for collecting data from the sea areas that are not easily reachable by research vessels or remote sensing. The observational data for Baltic Sea off-shore areas is very sparse and new observational methods are needed to fill the gaps in our knowledge and collect new data for different purposes, such as, operational activities, modelling and ocean science. The ARGO floats have been used successfully in the deep oceans. However, applying the ARGO floats in Baltic Sea is not straight forward, as the conditions differ greatly: the water is brackish, some areas are heavily trafficked and the northern parts freeze during the winter. In addition, the mean depth is only 54 metres, which is only a fraction of depths where ARGO floats have commonly been used. FMI has deployed three ARGO floats in Baltic Sea for different missions. The first ARGO was deployed in 2012 with normal diving algorithm, which checks the pressure hourly. The second float was modified by Aalto University so that the algorithm checks the pressure every 15 minutes. The first float was deployed in the Bothnian Sea in May 2013 and it measured over 200 profiles during its half year mission. The float with faster pressure detection was deployed in the Bothnian Sea in May 2013, and during it's 4 month mission it measured succesfully over 120 profiles. Another, longer test is ongoing on Eastern Gotland basin, where another ARGO float was deployed at Aug 2013, and still measures at Jan 2014. This one differs from earlier experiments as it has additional oxygen and scattering meters, also the area of measurements is deeper (200+ meters). The missions so far indicate, that with proper control and monitoring, ARGO's can be operated, and can measure long series of profiles. In addition to the actual measurements, the movement of ARGO floats gives possibilities to analyse currents in deeper areas of Baltic, and help

  11. CRAB NEBULA: FIVE-YEAR OBSERVATION WITH ARGO-YBJ

    Energy Technology Data Exchange (ETDEWEB)

    Bartoli, B.; Catalanotti, S.; D' Ettorre Piazzoli, B.; Di Girolamo, T. [Dipartimento di Fisica dell' Università di Napoli " Federico II," Complesso Universitario di Monte Sant' Angelo, via Cinthia, I-80126 Napoli (Italy); Bernardini, P.; D' Amone, A.; De Mitri, I. [Dipartimento Matematica e Fisica " Ennio De Giorgi," Università del Salento, via per Arnesano, I-73100 Lecce (Italy); Bi, X. J.; Cao, Z.; Chen, S. Z. [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918, 100049 Beijing (China); Branchini, P.; Budano, A. [Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tre, via della Vasca Navale 84, I-00146 Roma (Italy); Camarri, P. [Dipartimento di Fisica dell' Università di Roma " Tor Vergata," via della Ricerca Scientifica 1, I-00133 Roma (Italy); Cardarelli, R.; Di Sciascio, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tor Vergata, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Chen, T. L.; Danzengluobu [Tibet University, 850000 Lhasa, Xizang (China); Creti, P. [Istituto Nazionale di Fisica Nucleare, Sezione di Lecce, via per Arnesano, I-73100 Lecce (Italy); Cui, S. W. [Hebei Normal University, Shijiazhuang 050016 Hebei (China); Dai, B. Z., E-mail: vernetto@to.infn.it [Yunnan University, 2 North Cuihu Rd., 650091 Kunming, Yunnan (China); Collaboration: ARGO-YBJ Collaboration; and others

    2015-01-10

    The ARGO-YBJ air shower detector monitored the Crab Nebula gamma-ray emission from 2007 November to 2013 February. The integrated signal, consisting of ∼3.3 × 10{sup 5} events, reached the statistical significance of 21.1 standard deviations. The obtained energy spectrum in the energy range 0.3-20 TeV can be described by a power law function dN/dE = I {sub 0} (E/2 TeV){sup –α}, with a flux normalization I {sub 0} = (5.2 ± 0.2) × 10{sup –12} photons cm{sup –2} s{sup –1} TeV{sup –1} and α = 2.63 ± 0.05, corresponding to an integrated flux above 1 TeV of 1.97 × 10{sup –11} photons cm{sup –2} s{sup –1}. The systematic error is estimated to be less than 30% for the flux normalization and 0.06 for the spectral index. Assuming a power law spectrum with an exponential cutoff dN/dE = I {sub 0} (E/2 TeV){sup –α} exp (–E/E {sub cut}), the lower limit of the cutoff energy E {sub cut} is 12 TeV, at 90% confidence level. Our extended data set allows the study of the TeV emission over long timescales. Over five years, the light curve of the Crab Nebula in 200-day bins is compatible with a steady emission with a probability of 7.3 × 10{sup –2}. A correlated analysis with Fermi-LAT data over ∼4.5 yr using the light curves of the two experiments gives a Pearson correlation coefficient r = 0.56 ± 0.22. Concerning flux variations on timescales of days, a ''blind'' search for flares with a duration of 1-15 days gives no excess with a significance higher than four standard deviations. The average rate measured by ARGO-YBJ during the three most powerful flares detected by Fermi-LAT is 205 ± 91 photons day{sup –1}, consistent with the average value of 137 ± 10 day{sup –1}.

  12. Accuracy of ARGOS locations of Pinnipeds at-sea estimated using Fastloc GPS.

    Directory of Open Access Journals (Sweden)

    Daniel P Costa

    Full Text Available BACKGROUND: ARGOS satellite telemetry is one of the most widely used methods to track the movements of free-ranging marine and terrestrial animals and is fundamental to studies of foraging ecology, migratory behavior and habitat-use. ARGOS location estimates do not include complete error estimations, and for many marine organisms, the most commonly acquired locations (Location Class 0, A, B, or Z are provided with no declared error estimate. METHODOLOGY/PRINCIPAL FINDINGS: We compared the accuracy of ARGOS Locations to those obtained using Fastloc GPS from the same electronic tags on five species of pinnipeds: 9 California sea lions (Zalophus californianus, 4 Galapagos sea lions (Zalophus wollebaeki, 6 Cape fur seals (Arctocephalus pusillus pusillus, 3 Australian fur seals (A. p. doriferus and 5 northern elephant seals (Mirounga angustirostris. These species encompass a range of marine habitats (highly pelagic vs coastal, diving behaviors (mean dive durations 2-21 min and range of latitudes (equator to temperate. A total of 7,318 ARGOS positions and 27,046 GPS positions were collected. Of these, 1,105 ARGOS positions were obtained within five minutes of a GPS position and were used for comparison. The 68(th percentile ARGOS location errors as measured in this study were LC-3 0.49 km, LC-2 1.01 km, LC-1 1.20 km, LC-0 4.18 km, LC-A 6.19 km, LC-B 10.28 km. CONCLUSIONS/SIGNIFICANCE: The ARGOS errors measured here are greater than those provided by ARGOS, but within the range of other studies. The error was non-normally distributed with each LC highly right-skewed. Locations of species that make short duration dives and spend extended periods on the surface (sea lions and fur seals had less error than species like elephant seals that spend more time underwater and have shorter surface intervals. Supplemental data (S1 are provided allowing the creation of density distributions that can be used in a variety of filtering algorithms to improve the

  13. The Application of ARGO Data to the Global Ocean Data Assimilation Operational System of NCC

    Institute of Scientific and Technical Information of China (English)

    LIU Yimin; ZHANG Renhe; YIN Yonghong; NIU Tao

    2005-01-01

    In this paper, we have preliminarily studied the application of ARGO (Array for Real-time Geostrophic Oceanography) data to the Global Ocean Data Assimilation System of National Climate Center of China (NCC-GODAS), which mainly contains 4 sub-systems such as data preprocessing, real-time wind stress calculating, variational analysis and interpolating, and ocean dynamic model. For the sake of using ARGO data, the relevant adjustment and improvement have been made at the corresponding aspects in the subsystems.Using the observation data from 1981 to 2003 including the ARGO data of 2001 to July. 2003, we have performed a series of numerical experiments on this system. Comparing with the corresponding results of NCEP, It is illustrated that using ARGO data can improve the results of NCC-GODAS in the region of the Middle Pacific, for instance SST, SSTA (SST anomalies), Nino index, sea sub-surface temperature,etc. Furthermore, it is obtained that NCC-GODAS benefits from ARGO data in the other regions such as Atlantic Ocean, Indian Ocean, and extratropical Pacific Ocean much more than in the tropical Pacific.

  14. Crab Nebula: five-year observation with ARGO-YBJ

    CERN Document Server

    ,

    2015-01-01

    The ARGO-YBJ air shower detector monitored the Crab Nebula gamma ray emission from 2007 November to 2013 February. The integrated signal, consisting of $\\sim$3.3 $\\times$ 10$^5$ events,reached the statistical significance of 21.1 standard deviations. The obtained energy spectrum in the energy range 0.3-20 TeV can be described by a power law function dN/dE = I$_0$ (E / 2 TeV)$^{-\\alpha}$, with a flux normalization I$_0$ = (5.2 $\\pm$ 0.2) $\\times$ 10$^{-12}$ photons cm$^{-2}$ s$^{-1}$ TeV$^{-1}$ and $\\alpha$ = 2.63 $\\pm$ 0.05, corresponding to an integrated flux above 1 TeV of 1.97 $\\times$ 10$^{-11}$ photons cm$^{-2}$ s$^{-1}$. The systematic error is estimated to be less than 30$\\%$ for the flux normalization and 0.06 for the spectral index. Assuming a power law spectrum with an exponential cutoff dN/dE = I$_0$ (E / 2 TeV)$^{-\\alpha}$ $\\exp$ (-E / E$_{cut}$), the lower limit of the cutoff energy E$_{cut}$ is 12 TeV, at 90$\\%$ confidence level. Our extended dataset allows the study of the TeV emission over lon...

  15. Sea surface freshening inferred from SMOS and ARGO salinity: impact of rain

    Directory of Open Access Journals (Sweden)

    J. Boutin

    2012-10-01

    Full Text Available The sea surface salinity (SSS measured from space by the Soil Moisture and Ocean Salinity (SMOS mission has recently been revisited by the European Space Agency first campaign reprocessing. We show that, with respect to the previous version, biases close to land and ice greatly decrease. The accuracy of SMOS SSS averaged over 10 days 100 × 100 km2 in the open ocean and estimated by comparison to ARGO SSS is on the order of 0.3–0.4 in tropical and subtropical regions and 0.5 in a cold region. The mean SSS −0.1 bias observed in the Tropical Pacific Ocean between 5° N and 15° N, relatively to other regions, is suppressed when SMOS rainy events, as detected on SSMIs rain rates, are removed from the SMOS-ARGO comparisons. The SMOS freshening is linearly correlated to SSMIs rain rate with a slope estimated to −0.14 mm−1 h, after correction for rain atmospheric contribution. This tendency is the signature of the temporal SSS variability between the time of SMOS and ARGO measurements linked to rain variability and of the vertical salinity stratification between the first centimeter of the sea surface layer sampled by SMOS and the 5 m depth sampled by ARGO. However, given that the whole set of collocations includes situations with rainy ARGO measurements collocated with non rainy SMOS measurements, the mean −0.1 bias and the negative skewness of the statistical distribution of SMOS minus ARGO SSS difference are very likely the mean signature of the vertical salinity stratification. In the future, the analysis of ongoing in situ salinity measurements in the top 50 cm of the sea surface and of Aquarius satellite SSS are expected to provide complementary information about the sea surface salinity stratification.

  16. Argo: enabling the development of bespoke workflows and services for disease annotation.

    Science.gov (United States)

    Batista-Navarro, Riza; Carter, Jacob; Ananiadou, Sophia

    2016-01-01

    Argo (http://argo.nactem.ac.uk) is a generic text mining workbench that can cater to a variety of use cases, including the semi-automatic annotation of literature. It enables its technical users to build their own customised text mining solutions by providing a wide array of interoperable and configurable elementary components that can be seamlessly integrated into processing workflows. With Argo's graphical annotation interface, domain experts can then make use of the workflows' automatically generated output to curate information of interest.With the continuously rising need to understand the aetiology of diseases as well as the demand for their informed diagnosis and personalised treatment, the curation of disease-relevant information from medical and clinical documents has become an indispensable scientific activity. In the Fifth BioCreative Challenge Evaluation Workshop (BioCreative V), there was substantial interest in the mining of literature for disease-relevant information. Apart from a panel discussion focussed on disease annotations, the chemical-disease relations (CDR) track was also organised to foster the sharing and advancement of disease annotation tools and resources.This article presents the application of Argo's capabilities to the literature-based annotation of diseases. As part of our participation in BioCreative V's User Interactive Track (IAT), we demonstrated and evaluated Argo's suitability to the semi-automatic curation of chronic obstructive pulmonary disease (COPD) phenotypes. Furthermore, the workbench facilitated the development of some of the CDR track's top-performing web services for normalising disease mentions against the Medical Subject Headings (MeSH) database. In this work, we highlight Argo's support for developing various types of bespoke workflows ranging from ones which enabled us to easily incorporate information from various databases, to those which train and apply machine learning-based concept recognition models

  17. Characterizing Ocean Turbulence from Argo, Acoustic Doppler, and Simulation Data

    Science.gov (United States)

    McCaffrey, Katherine

    Turbulence is inherently chaotic and unsteady, so observing it and modeling it are no easy tasks. The ocean's sheer size makes it even more difficult to observe, and its unpredictable and ever-changing forcings introduce additional complexities. Turbulence in the oceans ranges from basin scale to the scale of the molecular viscosity. The method of energy transfer between scales is, however, an area of active research, so observations of the ocean at all scales are crucial to understanding the basic dynamics of its motions. In this collection of work, I use a variety of datasets to characterize a wide range of scales of turbulence, including observations from multiple instruments and from models with different governing equations. I analyzed the largest scales of the turbulent range using the global salinity data of the Argo profiling float network. Taking advantage of the scattered and discontinuous nature of this dataset, the second-order structure function was calculated down to 2000m depth, and shown to be useful for predicting spectral slopes. Results showed structure function slopes of 2/3 at small scales, and 0 at large scales, which corresponds with spectral slopes of -5/3 at small scales, and -1 at large scales. Using acoustic Doppler velocity measurements, I characterized the meter- to kilometer-scale turbulence at a potential tidal energy site in the Puget Sound, WA. Acoustic Doppler current profiler (ADCP) and acoustic Doppler velocimeter (ADV) observations provided the data for an analysis that includes coherence, anisotropy, and intermittency. In order to more simply describe these features, a parameterization was done with four turbulence metrics, and the anisotropy magnitude, introduced here, was shown to most closely capture the coherent events. Then, using both the NREL TurbSim stochastic turbulence generator and the NCAR large-eddy simulation (LES) model, I calculated turbulence statistics to validate the accuracy of these methods in reproducing

  18. Intraseasonal Oscillation in Global Ocean Temperature Inferred from Argo

    Institute of Scientific and Technical Information of China (English)

    HU Ruijin; WEI Meng

    2013-01-01

    The intraseasonal oscillation (ISO; 14-97-day periods) of temperature in the upper 2000 m of the global ocean was studied based on Argo observations from 2003-2008.It is shown that near the surface the ISO existed mainly in a band east of 60°E,between 10°S and 10°N,and the region around the Antarctic Circumpolar Current (ACC).At other levels analyzed,the ISOs also existed in the regions of the Kuroshio,the Gulf Stream,the Indonesian throughflow,the Somalia current,and the subtropical countercurrent (STCC) of the North Pacific.The intraseasonal signals can be seen even at depths of about 2000 m in some regions of the global ocean.The largest amplitude of ISO appeared at the thermocline of the equatorial Pacific,Atlantic and Indian Ocean,with maximum standard deviation (STD) exceeding 1.2℃.The ACC,the Kuroshio,and the Gulf Stream regions all exhibited large STD for all levels analyzed.Especially at 1000 m,the largest STD appeared in the south and southeast of South Africa-a part of the ACC,with a maximum value that reached 0.5℃.The ratios of the intraseasonal temperature variance to the total variance at 1000 m and at the equator indicated that,in a considerable part of the global deep ocean,the ISO was dominant in the variations of temperature,since such a ratio exceeded even 50% there.A case study also confirmed the existence of the ISO in the deep ocean.These results provide useful information for the design of field observations in the global ocean.Analysis and discussion are also given for the mechanism of the ISO.

  19. Argo and other tidal structures around the milky way

    Directory of Open Access Journals (Sweden)

    Helio J. Rocha-Pinto

    2006-01-01

    Full Text Available Se realiz o una b usqueda de sobredensidades que pudieran estar asociadas con subestructuras en el halo gal actico en bajas latitudes a partir de una muestra de gigantes M de 2MASS. Bajo la hip otesis de que las poblaciones estelares en la V a L actea exterior deber an de estar distribuidas de manera m as o menos sim etrica, se utilizaron dos m etodos para identi car asimetr as en la distribuci on (l; b de gigantes M de 2MASS que pudieran ser indicios de sobredensidades estelares: (1 la veri caci on directa de simetr a en campos re ejados sobre varios c rculos mayores sim etricos hipot eticos en la Galaxia; y (2 la extracci on de un modelo gal actico sim etrico para la distribuci on de gigantes M a partir de la distribuci on observada. Si bien podemos con rmar varios de los aspectos reportados previamente de la corriente de marea Monoceros, un hallazgo mayor de nuestro trabajo es que el n ucleo aparente del sistema Monoceros no se localiza en Canis Major, como lo han sugerido otras exploraciones, sino con mayor probabilidad a mayor l, en la regi on de la antigua constelaci on Argo (actualmente Puppis, Vela y Carina. Adem as del extenso sistema Monoceros, identi camos varias otras sobredensidades de gigantes M, principalmente a mayores distancias. Algunas de ellas corresponden a sistemas encontrados previamente en Triangulo-Andr omeda y Perseo, mientras que la naturaleza de otros de menor signi cado permanece incierta o puede ser atribuida a asimetr as de primer plano de estrellas enanas M contaminantes.

  20. Argos: Internacionalización en un entorno de conflicto armado Argos: Internacionalización en un entorno de conflicto armado*

    Directory of Open Access Journals (Sweden)

    Juan David Penagos Tascón

    2008-12-01

    Full Text Available This case study illustrates how Argos achieved to become one of the largest cement and concrete suppliers of Latin America, in spite of the fact that some of its production facilities are located in armed conflict areas. For that reason, the company implemented various corporate social responsibility strategies to overcome the difficulties of operating in these areas. These strategies contributed to the consolidation of the company’s operations under a single juridical and administrative entity, and facilitated the internationalization process to Central America, the Caribbean and the United States.Este caso de estudio empresarial muestra cómo la compañía Argos logró convertirseen uno de los proveedores de cemento y concreto más grandes de Latinoamérica,a pesar de que algunas de sus plantas productoras se encontraban ubicadas enzonas de conflicto armado, razón por la cual se desarrollaron diferentes iniciativasde responsabilidad social corporativa que permitieron operar en estas zonas.Garantizada la continuidad del negocio, las autoridades de Argos decidenconsolidar todas sus operaciones en una sola razón jurídica y administrativa yllevar a la empresa a un proceso de internacionalización en Centroamérica, Caribey Estados Unidos.

  1. On-line satellite/central computer facility of the Multiparticle Argo Spectrometer System

    International Nuclear Information System (INIS)

    An on-line satellite/central computer facility has been developed at Brookhaven National Laboratory as part of the Multiparticle Argo Spectrometer System (MASS). This facility consisting of a PDP-9 and a CDC-6600, has been successfully used in study of proton-proton interactions at 28.5 GeV/c. (U.S.)

  2. Tudengid teevad oma kohviku / Argo Ralja ; intervjueerinud Triinu Püvi

    Index Scriptorium Estoniae

    Ralja, Argo

    2012-01-01

    Intervjuu Tallinna Ülikooli Üliõpilaskonna esimehe Argo Raljaga, kes on olnud tihedalt seotud kohviku idee elluviimisega. Üliõpilaskohvik hakkab asuma ülikoolilinnakus Astra majas ning projekt on usaldatud Üliõpilaskonna kätesse

  3. Parametric improvement for the ingestion dose module of the European ARGOS and RODOS decision support systems

    DEFF Research Database (Denmark)

    Andersson, Kasper Grann; Nielsen, Sven Poul; Thørring, H.;

    2011-01-01

    The European decision support systems ARGOS and RODOS rely on the ECOSYS model for prognoses of ingestion doses. ECOSYS needs an update of various parameter values to provide reliable estimates. This paper reports on some results of a Nordic initiative to derive parameter values that are specific...

  4. Improving ingestion dose modelling for the ARGOS and RODOS decision support systems: A Nordic Initiative

    DEFF Research Database (Denmark)

    Andersson, Kasper Grann; Nielsen, Sven Poul; Thørring, Håvard;

    2011-01-01

    A Nordic work group under the NKS-B activity PARDNOR has revised the input parameters in the ECOSYS model that is incorporated for ingestion dose modelling in the ARGOS and RODOS decision support systems. The new parameterisation takes into account recent measurement data, and targets the model f...

  5. Design of the wavefront sensor unit of ARGOS, the LBT laser guide star system

    CERN Document Server

    Bonaglia, Marco

    2012-01-01

    ARGOS is the laser guide star ground layer adaptive optics system of the LBT. ARGOS is designed to bring a moderate but uniform reduction of the PSF size over a FoV as large as 4x4arcmin, allowing a significative increase of the science throughput of LUCI, the LBT NIR imager and MOS. ARGOS relays on 3 Rayleigh beacons to sense the lower layers of the atmosphere achieving almost 100% sky coverage. The ground layer AO correction is allowed by the 2 adaptive secondaries of the LBT. This PhD thesis first discusses a study based on numerical simulations and aimed to evaluate the performance of ARGOS. This work has been carried out using CAOS and representing in the code most of the features that characterize the system itself: as the laser beacon propagation in the atmosphere, the SH type wavefront sensing, the AO reconstruction and closed loop delays and the atmosphere tip-tilt sensing done using a NGS and a quad-cell type sensor. The results obtained in this study are in agreement and definitively confirm the pe...

  6. Üks suund, kaks vaadet / Tiit Land, Argo Ralja ; intervjueerinud Katrin Reimann

    Index Scriptorium Estoniae

    Land, Tiit, 1964-

    2012-01-01

    Intervjuu Tallinna Ülikooli rektori Tiit Landi ja Üliõpilaskonna juhatuse esimehe Argo Raljaga Tallinna Ülikooli iseloomustavatest märksõnadest möödunud aastal, positsioonist Eesti hariduses, ülikooli koostööst instituutide ja kolledžitega

  7. Aptychi from the Lower Cretaceous strata along the Río Argos (Caravaca, SE Spain)

    NARCIS (Netherlands)

    Vašícek, Z.; Hoedemaeker, Ph.J.

    1997-01-01

    The aptychi of the Berriasian to Barremian strata of the Río Argos succession near Caravaca (SE Spain) are described. One new subspecies is introduced, Lamellaptychus angulocostatus gracilicostatus, from the latest Hauterivian Ohmi Zone (ammonite zone). Like in the Eastern Alps also in Southern Spai

  8. Temperature, salinity and dissolved oxygen profile data from globally distributed Argo profiling floats through the month of September 2016 for the Global Argo Data Repository, 1995-09-07 to 2016-09-30 (NODC Accession 0042682)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent all data collected from Argo profiling floats through the current month (September 2016). The NOAA National Centers for Environmental...

  9. CRED APEX Drifting Buoy Argos_ID 25321 Data in the Northwestern Hawaiian Islands, 200110-200404 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED APEX drifter Argos_ID 25321 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. APEX drifter data files...

  10. CRED SVP Drifting Buoy Argos_ID 24753 Data in American Samoa, 200307-200407 (NODC Accession 0067474)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 24753 was deployed in the region of American Samoa to assess ocean currents and sea surface temperature. SVP drifter data files contain...

  11. CRED SVP Drifting Buoy Argos_ID 44765 Data, Manua in the American Samoa, 200402-200406 (NODC Accession 0067474)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 44765 was deployed in the region of American Samoa to assess ocean currents and sea surface temperature. SVP drifter data files contain...

  12. CRED APEX Drifting Buoy Argos_ID 25330 Data Maro Reef, Northwestern Hawaiian Islands, 200109-200201 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED APEX drifter Argos_ID 25330 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. APEX drifter data files...

  13. CRED SVP Drifting Buoy Argos_ID 30147 Data Nihoa, Northwestern Hawaiian Islands, 200209-200501 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 30147 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. SVP drifter data files...

  14. CRED SVP Drifting Buoy Argos_ID 29099 Data, Rota in the Marianas Archipelago, 200309-200402 (NODC Accession 0067473)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 29099 was deployed in the region of Marianas Archipelago to assess ocean currents and sea surface temperature. SVP drifter data files...

  15. CRED SVP Drifting Buoy Argos_ID 52299 Data, Arakane in the Marianas Archipelago, 200509-200607 (NODC Accession 0067473)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 52299 was deployed in the region of the Marianas Archipelago to assess ocean currents and sea surface temperature. drifter data files...

  16. CRED SVP Drifting Buoy Argos_ID 30225 Data in the Northwestern Hawaiian Islands, 200209-200401 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 30225 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. SVP drifter data files...

  17. CRED SVP Drifting Buoy Argos_ID 29938 Data in the Northwestern Hawaiian Islands, 200209-200312 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 29938 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. SVP drifter data files...

  18. CRED SVP Drifting Buoy Argos_ID 24666 Data in the American Samoa, 200309-200503 (NODC Accession 0067474)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 24666 was deployed in the region of American Samoa to assess ocean currents and sea surface temperature. SVP drifter data files contain...

  19. CRED SVP Drifting Buoy Argos_ID 35646 Data in the American Samoa, 200202-200302 (NODC Accession 0067474)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 35646 was deployed in the region of American Samoa to assess ocean currents and sea surface temperature. SVP drifter data files contain...

  20. CRED APEX Drifting Buoy Argos_ID 25333 Data in the NW Hawaiian Islands, 200110-200204 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED APEX drifter Argos_ID 25333 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. APEX drifter data files...

  1. CRED SVP Drifting Buoy Argos_ID 35644 Data Tau, American Samoa, 200202-200207 (NODC Accession 0067474)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 35644 was deployed in the region of American Samoa to assess ocean currents and sea surface temperature. SVP drifter data files contain...

  2. Enhancing the use of Argos satellite data for home range and long distance migration studies of marine animals.

    Directory of Open Access Journals (Sweden)

    Xavier Hoenner

    Full Text Available Accurately quantifying animals' spatial utilisation is critical for conservation, but has long remained an elusive goal due to technological impediments. The Argos telemetry system has been extensively used to remotely track marine animals, however location estimates are characterised by substantial spatial error. State-space models (SSM constitute a robust statistical approach to refine Argos tracking data by accounting for observation errors and stochasticity in animal movement. Despite their wide use in ecology, few studies have thoroughly quantified the error associated with SSM predicted locations and no research has assessed their validity for describing animal movement behaviour. We compared home ranges and migratory pathways of seven hawksbill sea turtles (Eretmochelys imbricata estimated from (a highly accurate Fastloc GPS data and (b locations computed using common Argos data analytical approaches. Argos 68(th percentile error was 4 km for LC ≤ 0. Argos error structure was highly longitudinally skewed and was, for all LC, adequately modelled by a Student's t distribution. Both habitat use and migration routes were best recreated using SSM locations post-processed by re-adding good Argos positions (LC 1, 2 and 3 and filtering terrestrial points (mean distance to migratory tracks ± SD = 2.2 ± 2.4 km; mean home range overlap and error ratio = 92.2% and 285.6 respectively. This parsimonious and objective statistical procedure however still markedly overestimated true home range sizes, especially for animals exhibiting restricted movements. Post-processing SSM locations nonetheless constitutes the best analytical technique for remotely sensed Argos tracking data and we therefore recommend using this approach to rework historical Argos datasets for better estimation of animal spatial utilisation for research and evidence-based conservation purposes.

  3. Sea surface freshening inferred from SMOS and ARGO salinity: impact of rain

    Directory of Open Access Journals (Sweden)

    J. Boutin

    2013-02-01

    Full Text Available The sea surface salinity (SSS measured from space by the Soil Moisture and Ocean Salinity (SMOS mission has recently been revisited by the European Space Agency first campaign reprocessing. We show that, with respect to the previous version, biases close to land and ice greatly decrease. The accuracy of SMOS SSS averaged over 10 days, 100 × 100 km2 in the open ocean and estimated by comparison to ARGO (Array for Real-Time Geostrophic Oceanography SSS is on the order of 0.3–0.4 in tropical and subtropical regions and 0.5 in a cold region. The averaged negative SSS bias (−0.1 observed in the tropical Pacific Ocean between 5° N and 15° N, relatively to other regions, is suppressed when SMOS observations concomitant with rain events, as detected from SSM/Is (Special Sensor Microwave Imager rain rates, are removed from the SMOS–ARGO comparisons. The SMOS freshening is linearly correlated to SSM/Is rain rate with a slope estimated to −0.14 mm−1 h, after correction for rain atmospheric contribution. This tendency is the signature of the temporal SSS variability between the time of SMOS and ARGO measurements linked to rain variability and of the vertical salinity stratification between the first centimeter of the sea surface layer sampled by SMOS and the 5 m depth sampled by ARGO. However, given that the whole set of collocations includes situations with ARGO measurements concomitant with rain events collocated with SMOS measurements under no rain, the mean −0.1 bias and the negative skewness of the statistical distribution of SMOS minus ARGO SSS difference are very likely the mean signature of the vertical salinity stratification. In the future, the analysis of ongoing in situ salinity measurements in the top 50 cm of the sea surface and of Aquarius satellite SSS are expected to provide complementary information about the sea surface salinity stratification.

  4. Typical Surface Seasonal Circulation in the Indian Ocean Derived from Argos Floats

    Institute of Scientific and Technical Information of China (English)

    ZHENG Shao-Jun; ZHANG Yu-Hong; ZHUANG Wei; LI Jia-Xun; DU Yan

    2012-01-01

    This study investigates the surface circulation in the Indian Ocean using Argos float data over the period 1979--2011. The Argos observations manifest some new phenomena. The climatological annual mean circulation shows that the surface current becomes much stronger after turning around in shore in the western Indian Ocean. In the tropical Indian Ocean, the Great Whirl (GW) to the east of Somalia develops quickly in spring (April-May) as the monsoon reverses to move northward, becoming strongest in summer (June-September) and disappearing in autumn (October-November). The west end of the Agulhas retroflection can reach 18°E, and it exhibits a seasonal variation. At approximately 90°E, the Agulhas Return Current combines with the eastward South Atlantic Current and finally joins the Antarctic Circumpolar Current.

  5. Improvement of bias detection in Argo float conductivity sensors and its application in the North Atlantic

    Science.gov (United States)

    Cabanes, Cécile; Thierry, Virginie; Lagadec, Catherine

    2016-08-01

    We propose modifications of the OW method (Owens and Wong, 2009) used to estimate the time-varying correction of conductivity measurements from Argo floats. These modifications are necessary to account for large interannual to decadal variability of the large-scale salinity field observed, for instance, in the North-Atlantic Ocean and to provide corrections with realistic error bars. The covariance function used to map reference salinity data at the float profile position was modified in order to minimize the contribution of the oldest reference data to the large-scale salinity field estimate. Mapping error now includes errors in the large-scale field estimates and fit error now takes into account the lateral dependence between climatological profiles. Finally, we used the modified OW method to check the consistency of the Argo salinity dataset available in delayed mode in the North-Atlantic Ocean. Overall, salinity corrections need to be reconsidered for 4.5% of the floats.

  6. Using Altimetry, GRACE and Argo to assess stationary circulation and transports in the North Atlantic

    OpenAIRE

    Richter, Falk; Sidorenko, Dmitry; Schröter, Jens

    2010-01-01

    The data available from satellite altimetry and Argo profiling buoys are combined into Inverse Finite Element Ocean model (IFEOM) for each of the years 1999 and 2008. The model solves for temperature and salinity fields that are close to measurements, respects stationary dynamical balances, and simultaneously produces estimates of the circulation. Several experiments have been performed to reconstruct the interannual variability. We show, that including altimetry improves the circulation pict...

  7. SMOS validation using SSS data from Barcelona World Race and Argo profilers

    Science.gov (United States)

    Umbert, M.; Ballabrera, J.; Fernandez, P.; Salat, J.; Salvador, J.

    2012-04-01

    The organisers of the Barcelona World Race (BWR), the Institute of Marine Sciences (ICM-CSIC) and the Maritime Catalan Forum (FMC) agreed on equiping the FMC boat, participating in the race, with a SeaBird MiniCTD. The idea was for the first time to explore how such oceanic races could help to monitor surface temperature and salinity all around the world ocean in real time. The boat spent 112 days to complete the rond trip, sending 12-30 real-time samples/day via ARGOS satellites, using a transmitter developed at the ICM. Data was also stored in the instrument, at 192 samples/day to allow further final global analyses. In the SMOS (Soil Moisture and Ocean Salinity) satellite mission processing chain, sea surface salinity (SSS) values are retrieved from brightness temperature data at level 2 (L2). Global maps of SSS are being generated at level 3 (L3) using spatial and temporal weighted averages. Finally, improved representations of the SSS field are obtained at level 4 (L4) where satellite data is blended with data from other sensors. In the present study, validation of L2, L3 and L4 products using data from BWR and ARGO buoys is presented, covering the race period from January to April 2011. Differences between these two sets of data are also investigated as the uppermost robust measurements from Argo profilers have larger depths than the ones associated to the BWR boat.

  8. Impact study of the Argo array definition in the Mediterranean Sea based on satellite altimetry gridded data

    Science.gov (United States)

    Sanchez-Roman, Antonio; Ruiz, Simón; Pascual, Ananda; Guinehut, Stéphanie; Mourre, Baptiste

    2016-04-01

    The existing Argo network provides essential data in near real time to constrain monitoring and forecasting centers and strongly complements the observations of the ocean surface from space. The comparison of Sea Level Anomalies (SLA) provided by satellite altimeters with in-situ Dynamic Heights Anomalies (DHA) derived from the temperature and salinity profiles of Argo floats contribute to better characterize the error budget associated with the altimeter observations. In this work, performed in the frame of the E-AIMS FP7 European Project, we focus on the Argo observing system in the Mediterranean Sea and its impact on SLA fields provided by satellite altimetry measurements in the basin. Namely, we focus on the sensitivity of specific SLA gridded merged products provided by AVISO in the Mediterranean to the reference depth (400 or 900 dbar) selected in the computation of the Argo Dynamic Height (DH) as an integration of the Argo T/S profiles through the water column. This reference depth will have impact on the number of valid Argo profiles and therefore on their temporal sampling and the coverage by the network used to compare with altimeter data. To compare both datasets, altimeter grids and synthetic climatologies used to compute DHA were spatially and temporally interpolated at the position and time of each in-situ Argo profile by a mapping method based on an optimal interpolation scheme. The analysis was conducted in the entire Mediterranean Sea and different sub-regions of the basin. The second part of this work is devoted to investigate which configuration in terms of spatial sampling of the Argo array in the Mediterranean will properly reproduce the mesoscale dynamics in this basin, which is comprehensively captured by new standards of specific altimeter products for this region. To do that, several Observing System Simulation Experiments (OSSEs) were conducted assuming that altimetry data computed from AVISO specific reanalysis gridded merged product for

  9. Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hogerton, John

    1964-01-01

    This pamphlet describes how reactors work; discusses reactor design; describes research, teaching, and materials testing reactors; production reactors; reactors for electric power generation; reactors for supply heat; reactors for propulsion; reactors for space; reactor safety; and reactors of tomorrow. The appendix discusses characteristics of U.S. civilian power reactor concepts and lists some of the U.S. reactor power projects, with location, type, capacity, owner, and startup date.

  10. Estimating the global oceanic net freshwater flux from Argo and comparing it with satellite-based freshwater flux products

    Science.gov (United States)

    Ren, Li; Hackert, Eric; Arkin, Phillip; Busalacchi, Antonio J.

    2014-11-01

    Following the idea that analysis of in situ information in the salt budget could be used as a surrogate for global "ocean rain gauge," the annual mean oceanic net freshwater flux (E-P) was estimated from the Argo profiles and the wind stress data on a global scale. The comparison between the independent E-P estimation from Argo and the E-P product sets, including the combination of precipitation from TRMM, GPCP, CMAP and evaporation from OAFlux, GSSTF3 and IFREMER and E-P set from NEWS formed from satellite, generally show similar spatial patterns, particularly on the large scale. However, there are differences among the different satellite-based E-P estimates and between satellite estimates and independent in situ estimates. Based on the pattern correlation and the RMSD, the evaporation and precipitation from OAFlux and TRMM agrees best with the E-P estimated from the independent Argo-based estimates.

  11. Evaluation of Argos Telemetry Accuracy in the High-Arctic and Implications for the Estimation of Home-Range Size.

    Directory of Open Access Journals (Sweden)

    Sylvain Christin

    Full Text Available Animal tracking through Argos satellite telemetry has enormous potential to test hypotheses in animal behavior, evolutionary ecology, or conservation biology. Yet the applicability of this technique cannot be fully assessed because no clear picture exists as to the conditions influencing the accuracy of Argos locations. Latitude, type of environment, and transmitter movement are among the main candidate factors affecting accuracy. A posteriori data filtering can remove "bad" locations, but again testing is still needed to refine filters. First, we evaluate experimentally the accuracy of Argos locations in a polar terrestrial environment (Nunavut, Canada, with both static and mobile transmitters transported by humans and coupled to GPS transmitters. We report static errors among the lowest published. However, the 68th error percentiles of mobile transmitters were 1.7 to 3.8 times greater than those of static transmitters. Second, we test how different filtering methods influence the quality of Argos location datasets. Accuracy of location datasets was best improved when filtering in locations of the best classes (LC3 and 2, while the Douglas Argos filter and a homemade speed filter yielded similar performance while retaining more locations. All filters effectively reduced the 68th error percentiles. Finally, we assess how location error impacted, at six spatial scales, two common estimators of home-range size (a proxy of animal space use behavior synthetizing movements, the minimum convex polygon and the fixed kernel estimator. Location error led to a sometimes dramatic overestimation of home-range size, especially at very local scales. We conclude that Argos telemetry is appropriate to study medium-size terrestrial animals in polar environments, but recommend that location errors are always measured and evaluated against research hypotheses, and that data are always filtered before analysis. How movement speed of transmitters affects location

  12. Evaluation of Argos Telemetry Accuracy in the High-Arctic and Implications for the Estimation of Home-Range Size.

    Science.gov (United States)

    Christin, Sylvain; St-Laurent, Martin-Hugues; Berteaux, Dominique

    2015-01-01

    Animal tracking through Argos satellite telemetry has enormous potential to test hypotheses in animal behavior, evolutionary ecology, or conservation biology. Yet the applicability of this technique cannot be fully assessed because no clear picture exists as to the conditions influencing the accuracy of Argos locations. Latitude, type of environment, and transmitter movement are among the main candidate factors affecting accuracy. A posteriori data filtering can remove "bad" locations, but again testing is still needed to refine filters. First, we evaluate experimentally the accuracy of Argos locations in a polar terrestrial environment (Nunavut, Canada), with both static and mobile transmitters transported by humans and coupled to GPS transmitters. We report static errors among the lowest published. However, the 68th error percentiles of mobile transmitters were 1.7 to 3.8 times greater than those of static transmitters. Second, we test how different filtering methods influence the quality of Argos location datasets. Accuracy of location datasets was best improved when filtering in locations of the best classes (LC3 and 2), while the Douglas Argos filter and a homemade speed filter yielded similar performance while retaining more locations. All filters effectively reduced the 68th error percentiles. Finally, we assess how location error impacted, at six spatial scales, two common estimators of home-range size (a proxy of animal space use behavior synthetizing movements), the minimum convex polygon and the fixed kernel estimator. Location error led to a sometimes dramatic overestimation of home-range size, especially at very local scales. We conclude that Argos telemetry is appropriate to study medium-size terrestrial animals in polar environments, but recommend that location errors are always measured and evaluated against research hypotheses, and that data are always filtered before analysis. How movement speed of transmitters affects location error needs

  13. An argo-based model for investigation of the Global Ocean (AMIGO)

    Science.gov (United States)

    Lebedev, K. V.

    2016-03-01

    We analyze the newly developed Argo-Based Model for Investigation of the Global Ocean (AMIGO), which consists of a block for variational interpolation of the profiles of drifting Argo floats to a regular grid and a block for model hydrodynamic adjustment of variationally interpolated fields. Such a method makes it possible to obtain a full set of oceanographic characteristics—temperature, salinity, density, and current velocity—using irregularly located Argo measurements. The resulting simulations are represented as monthly mean, seasonal, and annual means and climatological fields. The AMIGO oceanographic database developed at the Shirshov Institute of Oceanology from model simulations covers the 10-year period from 2005 to 2014. Analysis of transport variations in the propagation of North Atlantic Current jets to the Arctic based on the AMIGO data showed that during this period, anomalous winter transports were observed, which correlate with anomalous winter temperatures in regions of northwestern Europe, northern European Russia, and Iceland, which are subjected to the influence of these currents. Comparative analysis of variations in mass and heat transport by the currents and the North Atlantic Oscillation (NAO) index in the period of 2005-2014 shows a well pronounced correlation between them. The low winter values of the NAO index correspond to the low values of winter transports by the Faroe-Shetland branch of the North Atlantic current, and usually, to the high values of winter transports by the North Icelandic branch of the Irminger Current. High winter value of the NAO index results in a substantial increase in the winter transport by the Faroe-Shetland branch of the North Atlantic Current without notable influence on the transport of the North Icelandic branch of the Irminger Current.

  14. Circumpolar Estimates of Isopycnal Mixing in the ACC from Argo Floats

    Science.gov (United States)

    Roach, C. J.; Balwada, D.; Speer, K. G.

    2015-12-01

    There are few direct observations of cross-stream isopycnal mixing in the interior of the Southern Ocean, yet such measurements are needed to determine the role of eddies transporting properties across the ACC, and key to progress toward testing theories of meridional overturning. In light of this we examine if it is possible to obtain estimates of mixing from Argo float trajectories. We divided the Southern Ocean into overlapping 15ο longitude bins before estimating mixing. Resulting diffusivities ranged from 300 to 3000 m2s-1, with peaks corresponding to the Scotia Sea; Kerguelen and Campbell Plateaus. Comparison of our diffusivities with previous regional studies demonstrated good agreement. Tests of the methodology in the DIMES region found that mixing from Argo floats agreed closely with mixing from RAFOS floats. To further test the method we used the Southern Ocean State Estimate velocity fields to advect particles with Argo and RAFOS float like behaviours. Stirring estimates from the particles agreed well with each other in the Kerguelen Island region, South Pacific and Scotia Sea, despite the differences in the imposed behaviour. Finally, these estimates were compared to mixing length suppression theory presented in Ferrari and Nikurashin 2010. This mixing length suppression theory quantifies horizontal diffusivity similar to Prandtl (1925), but the mixing length is suppressed in the presence of mean flows and eddy phase speeds. Our results suggest that the theory can explain both the structure and magnitude of mixing using mean flow data. An exception is near the Kerguelen and Campbell Plateaus where theory under-estimates mixing relative to our results.

  15. The ARGOS laser system: green light for ground layer adaptive optics at the LBT

    Science.gov (United States)

    Raab, Walfried; Rabien, Sebastian; Gässler, Wolfgang; Esposito, Simone; Barl, Lothar; Borelli, Jose; Daysenroth, Matthias; Gemperlein, Hans; Kulas, Martin; Ziegleder, Julian

    2014-07-01

    We report on the development of the laser system of ARGOS, the multiple laser guide star adaptive optics system for the Large Binocular Telescope (LBT). The system uses a total of six high powered, pulsed Nd:YAG lasers frequency-doubled to a wavelength of 532 nm to generate a set of three guide stars above each of the LBT telescopes. The position of each of the LGS constellations on sky as well as the relative position of the individual laser guide stars within this constellation is controlled by a set of steerable mirrors and a fast tip-tilt mirror within the laser system. The entire opto-mechanical system is housed in two hermetically sealed and thermally controlled enclosures on the SX and DX side of the LBT telescope. The laser beams are propagated through two refractive launch telescopes which focus the beams at an altitude of 12 km, creating a constellation of laser guide stars around a 4 arcminute diameter circle by means of Rayleigh scattering. In addition to the GLAO Rayleigh beacon system, ARGOS has also been designed for a possible future upgrade with a hybrid sodium laser - Rayleigh beacon combination, enabling diffraction limited operation. The ARGOS laser system was successfully installed at the LBT in April 2013. Extensive functional tests have been carried out and have verified the operation of the systems according to specifications. The alignment of the laser system with respect to the launch telescope was carried out during two more runs in June and October 2013, followed by the first propagation of laser light on sky in November 2013.

  16. Argo data assimilation into HYCOM with an EnOI method in the Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    D. Mignac

    2014-07-01

    Full Text Available An ocean data assimilation system to assimilate Argo temperature (T and salinity (S profiles into HYCOM was constructed, implemented and evaluated for the first time in the Atlantic Ocean (78° S to 50° N and 98° W to 20° E. The system is based on the Ensemble Optimal Interpolation (EnOI algorithm proposed by Xie and Zhu (2010, especially made to deal with the hybrid nature of HYCOM vertical coordinate system with multiple steps. The Argo T/S profiles were projected to the model vertical space to create pseudo-observed layer thicknesses (Δ pobs which correspond to the model target densities. The first step was to assimilate Δ pobs considering the sub-state vector composed by the model layer thickness (Δ p and the baroclinic velocity components. After that, T and S were assimilated separately. At last, T was diagnosed below the mixed layer to preserve the density of the model isopycnal layers. Five experiments were performed from 1 January 2010 until 31 December 2012: a control run without assimilation, and four assimilation runs considering different vertical localizations of T, S and Δ p. The assimilation experiments were able to significantly improve the thermohaline structure produced by the control run. They reduced the RMSD of T (S calculated with respect to Argo independent data in 34.11% (43.56% in comparison to the control run. In some regions, such as the west North Atlantic, substantial corrections in the 20 °C isotherm depth and the upper ocean heat content towards climatological states were achieved. The runs with vertical localization of Δ p showed positive impacts in the correction of the thermohaline structure and reduced the RMSD of T (S from 0.993 °C (0.149 psu to 0.905 °C (0.138 psu for the whole domain with respect to the other assimilation runs.

  17. Interpolation of On-Line Data of the Argo Float System for Data Assimilation in the World Ocean Circulation Model

    Science.gov (United States)

    Zakharova, N. B.; Lebedev, S. A.

    2010-12-01

    For many years parameters of the World ocean state were measured by traditional contact methods that lacked in efficiency and the ability to measure temperature much beneath the surface. The ARGO float system involves both contact and distance ocean parameters measure methods. Sea temperature and salinity profiles are measured by contact methods, but data communication is made using satellites. Therefore, the ARGO float system has added efficiency and greater reliability to ocean parameters measurements. Interpolation and extrapolation methods of input information are important among numerical mathematical methods used for solving data assimilation problems. Thus the development of such algorithms and programs based on up-to-date approaches is a timely problem.

  18. Virtual Visit to the ATLAS Control Room by High schools of Argos prefecture

    CERN Multimedia

    2014-01-01

    Continuing the subatomic journey that started last year in Argos, Greece, 45 students from 14 high schools of the prefecture will take part in a dedicated ATLAS Masterclass organized by the University of Athens in the framework of the Go-Lab and Inspiring Science Education European projects. Students will learn how to analyse real events from the ATLAS experiment with the use of HYPATIA online applet. They will also have the opportunity to visit the ATLAS control room to learn what it takes for scientists to keep on pushing the boundaries of our understanding of the origins of the universe.

  19. Mean Interplanetary Magnetic Field Measurement Using the ARGO-YBJ Experiment

    CERN Document Server

    Aielli, G; Bartoli, B; Bernardini, P; Bi, X J; Bleve, C; Branchini, P; Budano, A; Bussino, S; Melcarne, A K Calabrese; Camarri, P; Cao, Z; Cappa, A; Cardarelli, R; Catalanotti, S; Cattaneo, C; Celio, P; Chen, S Z; Chen, T L; Chen, Y; Creti, P; Cui, S W; Dai, B Z; Staiti, G D'Alí; Danzengluobu,; Dattoli, M; De Mitri, I; Piazzoli, B D'Ettorre; De Vincenzi, M; Di Girolamo, T; Ding, X H; Di Sciascio, G; Feng, C F; Feng, Z Y; Feng, Zhenyong; Galeazzi, F; Galeotti, P; Gargana, R; Gou, Q B; Guo, Y Q; He, H H; Hu, Haibing; Hu, Hongbo; Huang, Q; Iacovacci, M; Iuppa, R; James, I; Jia, H Y; Labaciren,; Li, H J; Li, J Y; Li, X X; Liberti, B; Liguori, G; Liu, C; Liu, C Q; Liu, M Y; Liu, J; Lu, H; Ma, X H; Mancarella, G; Mari, S M; Marsella, G; Martello, D; Mastroianni, S; Meng, X R; Montini, P; Ning, C C; Pagliaro, A; Panareo, M; Perrone, L; Pistilli, P; Qu, X B; Rossi, E; Ruggieri, F; Saggese, L; Salvini, P; Santonico, R; Shen, P R; Sheng, X D; Shi, F; Stanescu, C; Surdo, A; Tan, Y H; Vallania, P; Vernetto, S; Vigorito, C; Wang, B; Wang, H; Wu, C Y; Wu, H R; Yao, Z G; Xu, B; Xue, L; Yan, Y X; Yang, Q Y; Yang, X C; Yuan, A F; Zha, M; Zhang, H M; Zhang, JiLong; Zhang, JianLi; Zhang, L; Zhang, P; Zhang, X Y; Zhang, Y; Zhaxisangzhu,; Zhaxiciren,; Zhou, X X; Zhu, F R; Zhu, Q Q; Zizzi, G

    2011-01-01

    The sun blocks cosmic ray particles from outside the solar system, forming a detectable shadow in the sky map of cosmic rays detected by the ARGO-YBJ experiment in Tibet. Because the cosmic ray particles are positive charged, the magnetic field between the sun and the earth deflects them from straight trajectories and results in a shift of the shadow from the true location of the sun. Here we show that the shift measures the intensity of the field which is transported by the solar wind from the sun to the earth.

  20. Spatial correlations applied to gamma/hadron discrimination in the ARGO-YBJ experiment

    International Nuclear Information System (INIS)

    Following recently proposed approaches on gamma/hadron separation, spatial correlations among secondary charged particles in extensive air showers have been studied for the case of the ARGO-YBJ experiment, which represents a particularly suited detector in this respect because of its “continuous-carpet” geometry. Two different types of statistics have been considered, namely the nearest-neighbor spacing distribution (NNSD) and the variance of the number of secondary particles at given distance. The results of this preliminary investigation are reported

  1. Recent Results from ArgoNeuT and Status of MicroBooNE

    Energy Technology Data Exchange (ETDEWEB)

    Szelc, Andrzej [Yale

    2015-07-10

    Liquid Argon Time Projection Chamber (LArTPC) detectors hold the key to answering the outstanding questions about the role of neutrinos in the Standard Model of Particle physics and beyond. Their fine granularity combined with calorimetric capabilities allows for precision measurements that answering these questions will require. Here, we discuss the recent results from the ArgoNeuT experiment as well as the status and prospects for MicroBooNE, both a part of the US-based LArTPC neutrino program.

  2. Pre-shipment test of the ARGOS laser guide star wavefront sensor

    Science.gov (United States)

    Bonaglia, Marco; Busoni, Lorenzo; Mazzoni, Tommaso; Puglisi, Alfio; Antichi, Jacopo; Esposito, Simone; Orban de Xivry, Gilles; Rabien, Sebastian

    2014-08-01

    We present the results of the laboratory characterization of the ARGOS LGS wavefront sensor (LGSW) and dichroic units. ARGOS is the laser guide star adaptive optics system of the Large Binocular Telescope (LBT). It implements a Ground Layer Adaptive Optics (GLAO) correction for LUCI, an infrared imager and multi-object spectrograph (MOS), using 3 pulsed Rayleigh beacons focused at 12km altitude. The LGSW is a Shack-Hartman sensor having 15 × 15 subaspertures over the telescope pupil. Each LGS is independently stabilized for on-sky jitter and gated to reduce spot elongation. The 3 LGS pupils are stabilized to compensate mechanical flexure and are arranged on a single detector. Two units of LGSW have been produced and tested at Arcetri Observatory. We report on the results obtained in the pre-shipment laboratory test: internal active flexure compensation loop performance, optomechanical stability under different gravity conditions, thermal cycling, Pockels cells performance. We also update on the upcoming installation and commissioning campaign at LBT.

  3. A calibration method of Argo floats based on multiple regression analysis

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Argo floats are free-moving floats that report vertical profiles of salinity, temperature and pressure at regular time intervals. These floats give good measurements of temperature and pressure, but salinity measurements may show significant sensor drifting with time. It is found that sensor drifting with time is not purely linear as presupposed by Wong (2003). A new method is developed to calibrate conductivity data measured by Argo floats. In this method, Wong's objective analysis method was adopted to estimate the background climatological salinity field on potential temperature surfaces from nearby historical data in WOD01. Furthermore, temperature and time factors are taken into account, and stepwise regression was used for a time-varying or temperature-varying slope in potential conductivity space to correct the drifting in these profiling float salinity data. The result shows salinity errors using this method are smaller than that of Wong's method, the quantitative and qualitative analysis of the conductivity sensor can be carried out with our method.

  4. The analog Resistive Plate Chamber detector of the ARGO-YBJ experiment

    CERN Document Server

    Bartoli, B; Bi, X J; Cao, Z; Catalanotti, S; Chen, S Z; Chen, T L; Cui, S W; Dai, B Z; D'Amone, A; Danzengluobu,; De Mitri, I; Piazzoli, B D'Ettorre; Di Girolamo, T; Di Sciascio, G; Feng, C F; Feng, Zhaoyang; Feng, Zhenyong; Gou, Q B; Guo, Y Q; He, H H; Hu, Haibing; Hu, Hongbo; Iacovacci, M; Iuppa, R; Jia, H Y; Labaciren,; Li, H J; Liu, C; Liu, J; Liu, M Y; Lu, H; Ma, L L; Ma, X H; Mancarella, G; Mari1, S M; Marsella, G; Mastroianni, S; Montini, P; Ning, C C; Perrone, L; Pistilli, P; Salvini1, P; Santonico, R; Shen, P R; Sheng, X D; Shi, F; Surdo, A; Tan, Y H; Vallania, P; Vernetto, S; Vigorito, C; Wang, H; Wu, C Y; Wu, H R; Xue, L; Yang, Q Y; Yang, X C; Yao, Z G; Yuan, A F; Zha, M; Zhang, H M; Zhang, L; Zhang, X Y; Zhang, Y; Zhao, J; Zhaxiciren,; Zhaxisangzhu,; Zhou, X X; Zhu, F R; Zhu, Q Q

    2015-01-01

    The ARGO-YBJ experiment has been in stable data taking from November 2007 till February 2013 at the YangBaJing Cosmic Ray Observatory (4300 m a.s.l.). The detector consists of a single layer of Resistive Plate Chambers (RPCs) ( about 6700 m^2}) operated in streamer mode. The signal pick-up is obtained by means of strips facing one side of the gas volume. The digital readout of the signals, while allows a high space-time resolution in the shower front reconstruction, limits the measurable energy to a few hundred TeV. In order to fully investigate the 1-10 PeV region, an analog readout has been implemented by instrumenting each RPC with two large size electrodes facing the other side of the gas volume. Since December 2009 the RPC charge readout has been in operation on the entire central carpet (about 5800 m^2). In this configuration the detector is able to measure the particle density at the core position where it ranges from tens to many thousands of particles per m^2. Thus ARGO-YBJ provides a highly detailed...

  5. From satellite altimetry to operational oceanography and Argo: three revolutions in oceanography (Fridtjof Nansen Medal Lecture)

    Science.gov (United States)

    Le Traon, P. Y.

    2012-04-01

    The launch of the US/French mission Topex/Poseidon (T/P) (CNES/NASA) in August 1992 was the start of a revolution in oceanography. For the first time, a very precise altimeter system optimized for large scale sea level and ocean circulation observations was flying. Topex/Poseidon revolutionized our vision and understanding of the ocean. It provided new views of the large scale seasonal and interannual sea level and ocean circulation variations. T/P alone could not observe the mesoscale circulation. In the 1990s, the ESA satellites ERS-1/2 were flying simultaneously with T/P. The ERS-1/2 orbit was well adapted for mesoscale circulation sampling but the orbit determination and altimeter performance were much less precise than for T/P. We demonstrated that we could use T/P as a reference mission for ERS-1/2 and bring the ERS-1/2 data to an accuracy level comparable to T/P. This was an essential first step for the merging of T/P and ERS-1/2. The second step required the development of a global optimal interpolation method. Near real time high resolution global sea level anomaly maps were then derived. These maps have been operationally produced as part of the SSALTO/DUACS system for the last 15 years. They are now widely used by the oceanographic community and have contributed to a much better understanding and recognition of the role and importance of mesoscale dynamics. The unique capability of satellite altimetry to observe the global ocean in near real time at high resolution was essential to the development of global ocean forecasting, a second revolution in oceanography. The Global Ocean Data Assimilation Experiment (GODAE) (1998-2008) was phased with the T/P and ERS-1/2 successors (Jason-1 and ENVISAT) and was instrumental in the development of global operational oceanography capabilities. Europe played a leading role in GODAE. In 1998, the global in-situ observing system was inadequate for the global scope of GODAE. This led to the development of Argo, an

  6. Small Berriasian, lower Valanginian and Barremian heteromorphic ammonites from the Río Argos succession (Caravaca, southeast Spain)

    NARCIS (Netherlands)

    Vasícek, V; Hoedemaeker, P.J.

    2003-01-01

    The small heteromorphic ammonites from the Berriasian, lower Valanginian and Barremian strata of the Río Argos succession (west of Caravaca, southeast Spain) are described. One new genus is introduced, Sabaudiella (type species Ancyloceras sabaudianum Pictet & de Loriol, 1858), and three new species

  7. Ammonite biostratigraphy of the uppermost Tithonian, Berriasian, and lower Valanginian along the Río Argos (Caravaca, SE Spain)

    NARCIS (Netherlands)

    Hoedemaeker, P.J.

    1982-01-01

    This paper deals with the ammonite biostratigraphy of the lower 312 m of the Miravetes Formation (sections Y and Z) exposed 500 m north and northwest of Los Miravetes along the Río Argos, 3 km west of Caravaca (SE Spain). This sequence embraces the uppermost Tithonian, Berriasian, and lower Valangin

  8. Present status and development trend of Argos System%Argos系统的发展现状与趋势

    Institute of Scientific and Technical Information of China (English)

    宋飞; 冯旭哲

    2012-01-01

    Argos系统作为具备单星定位能力的卫星通信系统,具有功耗低、体积小、全球覆盖以及数据实时性较好等优点,目前在对自然环境的科学观测中得到了广泛应用.从系统运行的角度,阐述了组成系统的平台部分、空间部分和地面部分;结合第二代和第三代Argos系统,分析了平台终端、空间卫星、地面系统以及主要应用四个方面的发展现状;最后对Argos系统发展趋势进行了探讨和展望.%As a satellite communication system with capability of the single-satellite positioning, Argos system has advantages of low power consumption, small size, global coverage and good real-time ability for data transmission, etc. Due to above merits, Argos system is widely applied in the scientific observation for the marine environment. The platform section, the space segment and the ground segment of which the Argos system consists, are described from the view of system operation. With a comprehensive consideration of the second and the third generation Argos system, the development status of such four aspects as the platform terminal, space satellites, the ground system and the main application field, are analyzed. Finally, an outlook for the development trend of the Argos system is given.

  9. From satellite altimetry to Argo and operational oceanography: three revolutions in oceanography

    Directory of Open Access Journals (Sweden)

    P. Y. Le Traon

    2013-10-01

    Full Text Available The launch of the French/US mission Topex/Poseidon (T/P (CNES/NASA in August 1992 was the start of a revolution in oceanography. For the first time, a very precise altimeter system optimized for large-scale sea level and ocean circulation observations was flying. T/P alone could not observe the mesoscale circulation. In the 1990s, the ESA satellites ERS-1/2 were flying simultaneously with T/P. Together with my CLS colleagues, we demonstrated that we could use T/P as a reference mission for ERS-1/2 and bring the ERS-1/2 data to an accuracy level comparable to T/P. Near-real-time high-resolution global sea level anomaly maps were then derived. These maps have been operationally produced as part of the SSALTO/DUACS system for the last 15 yr. They are now widely used by the oceanographic community and have contributed to a much better understanding and recognition of the role and importance of mesoscale dynamics. Altimetry needs to be complemented with global in situ observations. At the end of the 90s, a major international initiative was launched to develop Argo, the global array of profiling floats. This has been an outstanding success. Argo floats now provide the most important in situ observations to monitor and understand the role of the ocean on the earth climate and for operational oceanography. This is a second revolution in oceanography. The unique capability of satellite altimetry to observe the global ocean in near-real-time at high resolution and the development of Argo were essential for the development of global operational oceanography, the third revolution in oceanography. The Global Ocean Data Assimilation Experiment (GODAE was instrumental in the development of the required capabilities. This paper provides an historical perspective on the development of these three revolutions in oceanography which are very much interlinked. This is not an exhaustive review and I will mainly focus on the contributions we made together with many

  10. CRED SVP Drifting Buoy Argos_ID 24961 Data, South of Necker, in the Northwestern Hawaiian Islands, 200109-200406 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 24961 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. SVP drifter data files...

  11. CRED SVP Drifting Buoy Argos_ID 24756 Data, 10mn East of Upolu, in the American Samoa, 200307-200310 (NODC Accession 0067474)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 24756 was deployed in the region of American Samoa to assess ocean currents and sea surface temperature. SVP drifter data files contain...

  12. CRED SVP Drifting Buoy Argos_ID 29109 Data on the south side of Swains Island, American Samoa , 200402-200606 (NODC Accession 0067474)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 29109 was deployed in the region of American Samoa to assess ocean currents and sea surface temperature. SVP drifter data files contain...

  13. CRED SVP Drifting Buoy Argos_ID 24955 Data at Bank 8, in the NW Hawaiian Islands, 200110-200504 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 24955 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. SVP drifter data files...

  14. CRED SVP Drifting Buoy Argos_ID 29098 Data, Necker Island in the Northwestern Hawaiian Islands, 200307-200410 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 29098 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. SVP drifter data files...

  15. CRED SVP Drifting Buoy Argos_ID 24946 Data, north of Niihau, in the NW Hawaiian Islands, 200110-200209 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 24946 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. SVP drifter data files...

  16. CRED SVP Drifting Buoy Argos_ID 29102 Data, Lisianski Island in the Northwestern Hawaiian Islands, 200307-200310 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 29102 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. SVP drifter data files...

  17. CRED SVP Drifting Buoy Argos_ID 30288 Data near Necker in the NW Hawaiian Islands, 200209-200404 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 30288 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. SVP drifter data files...

  18. CRED SVP Drifting Buoy Argos_ID 29106 Data, Laysan Island in the Northwestern Hawaiian Islands, 200307-200411 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 29106 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. SVP drifter data files...

  19. CRED SVP Drifting Buoy Argos_ID 24754 Data, between Ofu and Tutuila, in the American Samoa, 200307-200308 (NODC Accession 0067474)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 24754 was deployed in the region of American Samoa to assess ocean currents and sea surface temperature. SVP drifter data files contain...

  20. CRED SVP Drifting Buoy Argos_ID 30111 Data, French Frigate Shoals in the Northwestern Hawaiian Islands, 200210-200309 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 30111 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. SVP drifter data files...

  1. CRED SVP Drifting Buoy Argos_ID 44769 Data, Enroute to Manua from Tutuila, in the American Samoa, 200402-200406 (NODC Accession 0067474)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 44769 was deployed in the region of American Samoa to assess ocean currents and sea surface temperature. SVP drifter data files contain...

  2. CRED SVP Drifting Buoy Argos_ID 30311 Data between Nihoa and Niihau in the NW Hawaiian Islands, 200210-200402 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 30311 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. SVP drifter data files...

  3. CRED SVP Drifting Buoy Argos_ID 29097 Data near Nihoa Island, in the Northwestern Hawaiian Islands, 200307-200412 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 29097 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. SVP drifter data files...

  4. CRED SVP Drifting Buoy Argos_ID 29101 Data, Kure Atoll in the Northwestern Hawaiian Islands, 200308-200509 (NODC Accession 0049436)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CRED SVP drifter Argos_ID 29101 was deployed in the region of NW Hawaiian Islands to assess ocean currents and sea surface temperature. SVP drifter data files...

  5. A neural network-based method for merging ocean color and Argo data to extend surface bio-optical properties to depth: Retrieval of the particulate backscattering coefficient

    Science.gov (United States)

    Sauzède, R.; Claustre, H.; Uitz, J.; Jamet, C.; Dall'Olmo, G.; D'Ortenzio, F.; Gentili, B.; Poteau, A.; Schmechtig, C.

    2016-04-01

    The present study proposes a novel method that merges satellite ocean color bio-optical products with Argo temperature-salinity profiles to infer the vertical distribution of the particulate backscattering coefficient (bbp). This neural network-based method (SOCA-BBP for Satellite Ocean-Color merged with Argo data to infer the vertical distribution of the Particulate Backscattering coefficient) uses three main input components: (1) satellite-based surface estimates of bbp and chlorophyll a concentration matched up in space and time with (2) depth-resolved physical properties derived from temperature-salinity profiles measured by Argo profiling floats and (3) the day of the year of the considered satellite-Argo matchup. The neural network is trained and validated using a database including 4725 simultaneous profiles of temperature-salinity and bio-optical properties collected by Bio-Argo floats, with concomitant satellite-derived products. The Bio-Argo profiles are representative of the global open-ocean in terms of oceanographic conditions, making the proposed method applicable to most open-ocean environments. SOCA-BBP is validated using 20% of the entire database (global error of 21%). We present additional validation results based on two other independent data sets acquired (1) by four Bio-Argo floats deployed in major oceanic basins, not represented in the database used to train the method; and (2) during an AMT (Atlantic Meridional Transect) field cruise in 2009. These validation tests based on two fully independent data sets indicate the robustness of the predicted vertical distribution of bbp. To illustrate the potential of the method, we merged monthly climatological Argo profiles with ocean color products to produce a depth-resolved climatology of bbp for the global ocean.

  6. Argo floats revealing bimodality of large-scale mid-depth circulation in the North Atlantic

    Institute of Scientific and Technical Information of China (English)

    CHU Peter C; IVANOV Leonid M; MELNICHENKO Oleg V; LI Rongfeng

    2008-01-01

    Analysis of Argo float trajectories at 1000 m and temperature at 950 m in the North Atlantic between November 2003 and January 2005 demonstrates the existence of two different circulation modes with fast transition between them. Each mode has a pair of cy-clonic - anticyclonic gyres. The difference is the location of the cyclonic gyre. The cyclonic gyre stretches from southeast to north-west in the first mode and from the southwest to the northeast in the second mode. The observed modes strongly affect the heat and salt transport in the North Atlantic. In particular, the second mode slows down the westward transport of the warm and saline water from the Mediterranean Sea.

  7. Impacts of XBT, TAO, Altimetry and ARGO Observations on the Tropical Pacific Ocean Data Assimilation

    Institute of Scientific and Technical Information of China (English)

    YAN Changxiang; ZHU Jiang; ZHOU Guangqing

    2007-01-01

    This study aims at assessing the relative impacts of four major components of the tropical Pacific Ocean observing system on assimilation of temperature and salinity fields. Observations were collected over a period between January 2001 through June 2003 including temperature data from the expendable bathythermographs (XBT), thermistor data from the Tropical Ocean Global Atmosphere Tropical Atmosphere-Ocean (TOGA-TAO) mooring array, sea level anomalies from the Topex/Poseidon and Jason-1 altimetry (T/P-J),and temperature and salinity profiles from the Array for Real-time Geostrophic Oceanography (ARGO) floats.An efficient three-dimensional variational analysis-based method was introduced to assimilate the above data into the tropical-Pacific circulation model. To evaluate the impact of the individual component of the observing system, four observation system experiments were carried out. The experiment that assimilated all four components of the observing system was taken as the reference. The other three experiments were implemented by withholding one of the four components. Results show that the spatial distribution of the data influences its relative contribution. XBT observations produce the most distinguished effects on temperature analyses in the off-equatorial region due to the large amount of measurements and high quality.Similarly, the impact of TAO is dominant in the equatorial region due to the focus of the spatial distribution.The Topex/Poseidon-Jason-1 can be highly complementary where the XBT and TAO observations are sparse.The contribution of XBT or TAO on the assimilated salinity is made by the model dynamics because no salinity observations from them are assimilated. Therefore, T/P-J, as a main source for providing salinity data, has been shown to have greater impacts than either XBT or TAO on the salinity analysis. Although ARGO includes the subsurface observations, the relatively smaller number of observation makes it have the smallest

  8. Error properties of Argos satellite telemetry locations using least squares and Kalman filtering.

    Directory of Open Access Journals (Sweden)

    Janice D Boyd

    Full Text Available Study of animal movements is key for understanding their ecology and facilitating their conservation. The Argos satellite system is a valuable tool for tracking species which move long distances, inhabit remote areas, and are otherwise difficult to track with traditional VHF telemetry and are not suitable for GPS systems. Previous research has raised doubts about the magnitude of position errors quoted by the satellite service provider CLS. In addition, no peer-reviewed publications have evaluated the usefulness of the CLS supplied error ellipses nor the accuracy of the new Kalman filtering (KF processing method. Using transmitters hung from towers and trees in southeastern Peru, we show the Argos error ellipses generally contain <25% of the true locations and therefore do not adequately describe the true location errors. We also find that KF processing does not significantly increase location accuracy. The errors for both LS and KF processing methods were found to be lognormally distributed, which has important repercussions for error calculation, statistical analysis, and data interpretation. In brief, "good" positions (location codes 3, 2, 1, A are accurate to about 2 km, while 0 and B locations are accurate to about 5-10 km. However, due to the lognormal distribution of the errors, larger outliers are to be expected in all location codes and need to be accounted for in the user's data processing. We evaluate five different empirical error estimates and find that 68% lognormal error ellipses provided the most useful error estimates. Longitude errors are larger than latitude errors by a factor of 2 to 3, supporting the use of elliptical error ellipses. Numerous studies over the past 15 years have also found fault with the CLS-claimed error estimates yet CLS has failed to correct their misleading information. We hope this will be reversed in the near future.

  9. Error properties of Argos satellite telemetry locations using least squares and Kalman filtering.

    Science.gov (United States)

    Boyd, Janice D; Brightsmith, Donald J

    2013-01-01

    Study of animal movements is key for understanding their ecology and facilitating their conservation. The Argos satellite system is a valuable tool for tracking species which move long distances, inhabit remote areas, and are otherwise difficult to track with traditional VHF telemetry and are not suitable for GPS systems. Previous research has raised doubts about the magnitude of position errors quoted by the satellite service provider CLS. In addition, no peer-reviewed publications have evaluated the usefulness of the CLS supplied error ellipses nor the accuracy of the new Kalman filtering (KF) processing method. Using transmitters hung from towers and trees in southeastern Peru, we show the Argos error ellipses generally contain <25% of the true locations and therefore do not adequately describe the true location errors. We also find that KF processing does not significantly increase location accuracy. The errors for both LS and KF processing methods were found to be lognormally distributed, which has important repercussions for error calculation, statistical analysis, and data interpretation. In brief, "good" positions (location codes 3, 2, 1, A) are accurate to about 2 km, while 0 and B locations are accurate to about 5-10 km. However, due to the lognormal distribution of the errors, larger outliers are to be expected in all location codes and need to be accounted for in the user's data processing. We evaluate five different empirical error estimates and find that 68% lognormal error ellipses provided the most useful error estimates. Longitude errors are larger than latitude errors by a factor of 2 to 3, supporting the use of elliptical error ellipses. Numerous studies over the past 15 years have also found fault with the CLS-claimed error estimates yet CLS has failed to correct their misleading information. We hope this will be reversed in the near future. PMID:23690980

  10. Salinity variability in the North Atlantic through synergetic analysis of Argo floats and satellite altimetry data

    Science.gov (United States)

    Stendardo, Ilaria; Rhein, Monika; Klein, Birgit; Roessler, Achim

    2015-04-01

    Salinity distribution in the North Atlantic is affected by changes in the circulation and freshwater fluxes. Changes in salinity are introduced into the ocean's interior by vertical processes like subduction or convection, and transported along circulation pathways. At a given location and depth, salinity could vary by water mass changes due to changes in the freshwater flux, or by vertical migration of density surfaces caused either by wind-driven changes of ocean ventilation or by thermodynamic processes, like poleward migration of isopycnals as a result of surface warming. Changes in the wind driven circulation with a consequence shift of the subpolar front, that separates the fresher subpolar from the saline subtropical gyre, also have a marked influence on upper ocean salinity in the subpolar North Atlantic. Due to the lack of temporal and spatial resolution of salinity observations, salinity anomalies in the last century could only be studied by 5-year means. Thanks to the Argo program, the temporal and spatial resolution of salinity and temperature profiles since early 2000 have significantly improved, allowing to calculate even monthly means. To further improve temporal and spatial resolution of salinity, Argo profiles are combined with altimetry data and a "Transfer function", the Gravest Empirical Mode (GEM), is calculated. The GEM technique exploits the relationship between T/S profiles and dynamic height in order to parameterize salinity data as a function of dynamic height from the satellite altimetry. This technique gives the opportunity to extend the investigation of the salinity variability, with extremely high temporal (daily) and spatial (1/4°) resolution, back to 1993, the beginning of the altimetry data. This method was tested on several regions of the North Atlantic and it works particularly well for some of them, for example in the regions where the North Atlantic Current plays an important role. Within these regions salinity variability in

  11. Estimation of eddy heat transport in the global ocean from Argo data

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhiwei; ZHONG Yisen; TIAN Jiwei; YANG Qingxuan; ZHAO Wei

    2014-01-01

    The Argo data are used to calculate eddy (turbulence) heat transport (EHT) in the global ocean and analyze its horizontal distribution and vertical structure. We calculate the EHT by averaging all the v′, T′ profiles within each 2◦× 2◦ bin. The velocity and temperature anomalies are obtained by removing their clima-tological values from the Argo“instantaneous”values respectively. Through the Student’s t-test and an error evaluation, we obtained a total of 87% Argo bins with significant depth-integrated EHTs (D-EHTs). The results reveal a positive-and-negative alternating D-EHT pattern along the western boundary currents (WBC) and Antarctic Circumpolar Current (ACC). The zonally-integrated D-EHT (ZI-EHT) of the global o-cean reaches 0.12 PW in the northern WBC band and-0.38 PW in the ACC band respectively. The strong ZI-EHT across the ACC in the global ocean is mainly caused by the southern Indian Ocean. The ZI-EHT in the above two bands accounts for a large portion of the total oceanic heat transport, which may play an important role in regulating the climate. The analysis of vertical structures of the EHT along the 35◦N and 45◦S section reveals that the oscillating EHT pattern can reach deep in the northern WBC regions and the Agulhas Return Current (ARC) region. It also shows that the strong EHT could reach 600 m in the WBC re-gions and 1 000 m in the ARC region, with the maximum mainly located between 100 and 400 m depth. The results would provide useful information for improving the parameterization scheme in models.

  12. Meso-scale circulation at the intermediate-depth east of Mindanao observed by Argo profiling floats

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The meso-scale circulation at the intermediate depth east of Mindanao is studied using Argo profiling floats observations. The trajectories and the parking-depth velocities of Argo floats show that the intermediate-depth circulation east of Mindanao contains significant meso-scale features that are highly variable both in space and in time. Both cyclonic and anticyclonic eddies at the intermediate depth (1000–2000 m) are indicated by the trajectories east of Mindanao. The mean tangential velocities of these eddies are about 10 cm/s at 2000 m and over 20 cm/s at 1000 m, which indicates that the geostrophic calculation may contain large errors due to the vigorous eddy activity at the reference levels. The analyses also suggest that these eddies might play an important role in mass and vorticity balances of the intermediate-depth circulation east of Mindanao.

  13. LIDERAZGO, LA COMPETENCIA ESENCIAL QUE TRANSFORMÓ UNA EMPRESA COLOMBIANA EN UN GIGANTE INTERNACIONAL: EL CASO DE CEMENTOS ARGOS

    Directory of Open Access Journals (Sweden)

    HÉCTOR OCHOA DÍAZ

    2011-01-01

    Full Text Available Cementos Argos ha sido catalogado como uno de los gigantes de la industria cementera colombiana por su gran capacidad de consolidación en el mercado nacional y sus estrategias de internacionalización poco convencionales. Esta investigación documenta la experiencia internacional de Argos bajo la perspectiva de las teorías de internacionalización de mayor aceptación en laliteratura internacional, haciendo uso del enfoque metodológico de los estudios de caso. Como resultado se encontró que las estrategias de fidelización,aunadas al rediseño organizacional resultado del liderazgo de la alta gerencia, han sido herramientas vitales para asegurar el crecimiento de la compañía en los mercados local y externo.

  14. Evaluation of Mid-Depth Currents of NCEP Reanalysis Data in the Tropical Pacific Using ARGO Float Position Information

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The global project of the Array for Real-time Geostrophic Oceanography (ARGO) provides a unique opportunity to observe the absolute velocity in mid-depths of the world oceans. A total of 1597 velocity vectors at 1000 (2000) db in the tropical Pacific derived from the ARGO float position information during the period November 2001 to October 2004 are used to evaluate the intermediate currents of the National Centers for Environmental Prediction reanalysis. To derive reliable velocity information from ARGO float trajectory points, a rigorous quality control scheme is applied, and by virtue of a correction method for reducing the drift error on the surface in obtaining the velocity vectors, their relative errors are less than 25%. Based on the comparisons from the quantitative velocity vectors and from the space-time average currents, some substantial discrepancies are revealed. The first is that the velocities of the reanalysis at mid-depths except near the equator are underestimated relative to the observed velocities by the floats.The average speed difference between NCEP and ARGO values ranges from about -2.3 cms-1 to -1.8cms-1. The second is that the velocity difference between the ocean model and the observations at 2000dB seems smaller than that at 1000 dB. The third is that the zonal flow in the reanalysis is too dominant so that some eddies could not be simulated, such as the cyclonic eddy to the east of 160°E between 20°N and 30°N at 2000 dB. In addition, it is noticeable that many floats parking at 1000 dB cannot acquire credible mid-depth velocities due to the time information of their end of ascent (start of descent) on the surface in the trajectory files. Thus, relying on default times of parking, descent and ascent in the metadata files gravely confines their application to measuring mid-depth currents.

  15. The Argos-CLS Kalman Filter: Error Structures and State-Space Modelling Relative to Fastloc GPS Data.

    Directory of Open Access Journals (Sweden)

    Andrew D Lowther

    Full Text Available Understanding how an animal utilises its surroundings requires its movements through space to be described accurately. Satellite telemetry is the only means of acquiring movement data for many species however data are prone to varying amounts of spatial error; the recent application of state-space models (SSMs to the location estimation problem have provided a means to incorporate spatial errors when characterising animal movements. The predominant platform for collecting satellite telemetry data on free-ranging animals, Service Argos, recently provided an alternative Doppler location estimation algorithm that is purported to be more accurate and generate a greater number of locations that its predecessor. We provide a comprehensive assessment of this new estimation process performance on data from free-ranging animals relative to concurrently collected Fastloc GPS data. Additionally, we test the efficacy of three readily-available SSM in predicting the movement of two focal animals. Raw Argos location estimates generated by the new algorithm were greatly improved compared to the old system. Approximately twice as many Argos locations were derived compared to GPS on the devices used. Root Mean Square Errors (RMSE for each optimal SSM were less than 4.25 km with some producing RMSE of less than 2.50 km. Differences in the biological plausibility of the tracks between the two focal animals used to investigate the utility of SSM highlights the importance of considering animal behaviour in movement studies. The ability to reprocess Argos data collected since 2008 with the new algorithm should permit questions of animal movement to be revisited at a finer resolution.

  16. Hydrodynamic features of the South Aegean Sea as derived from Argo T/ S and dissolved oxygen profiles in the area

    Science.gov (United States)

    Kassis, Dimitris; Krasakopoulou, Evangelia; Korres, Gerasimos; Petihakis, George; Triantafyllou, George S.

    2016-11-01

    In this work, the hydrodynamic picture of the South Aegean Sea is examined through an analysis of recent measurements in its sub-basins, the Myrtoan and Cretan Sea. Both sub-basins play an important role in the water circulation, exchange, and formation processes that affect the dynamics of the whole Eastern Mediterranean. For the first time, Bio-Argo floats were deployed in the area under the Greek Argo Research Infrastructure coordination. The acquired profiles cover an almost 2-year period (November 2013-July 2015) and are compared with previous Argo profiles and the re-processed time-series data recorded from the E1-M3A POSEIDON observatory operating in the area since 2007. The spatio-temporal distribution of the physical and chemical properties in each sub-basin is examined. Dense water formation events are revealed in the northern part (Myrtoan), while the wider area can be characterized as pre-conditioned. In the Cretan basin, a strong inter-annual variability of the salinity field at intermediate and deep layers is observed that is associated with water exchange from its open boundaries. Furthermore, comparison of the dissolved oxygen (DO) distribution with physical water properties within both the mixed layer, and at greater depths, indicated that relatively high but still under-saturated DO values are more likely to be associated with convection events. Finally, an updated picture of the physical properties and the DO distribution is presented based on the last 5 years of measurements and the recent introduction of Bio-Argo floats with DO sensors in the area.

  17. Uppermost Jurassic to Lower Cretaceous benthic foraminiferal biostratigraphy at ODP Site 765 on the Argo Abyssal Plain.

    OpenAIRE

    Kaminski, M.A.; Gradstein, F.M.; Geroch, S.

    1992-01-01

    Benthic foraminifers were studied in 99 samples collected from the lower 200 m of Hole 765C. The studied section ranges from the Tithonian to Aptian, and benthic foraminifers can be subdivided into five assemblages on the basis of faunal diversity and stratigraphic ranges of distinctive species. Compared with deep-water assemblages from Atlantic DSDP sites and Poland, assemblages from the Argo Abyssal Plain display a higher diversity of agglutinated forms, which comprise the autochthonous ...

  18. The Argos-CLS Kalman Filter: Error Structures and State-Space Modelling Relative to Fastloc GPS Data.

    Science.gov (United States)

    Lowther, Andrew D; Lydersen, Christian; Fedak, Mike A; Lovell, Phil; Kovacs, Kit M

    2015-01-01

    Understanding how an animal utilises its surroundings requires its movements through space to be described accurately. Satellite telemetry is the only means of acquiring movement data for many species however data are prone to varying amounts of spatial error; the recent application of state-space models (SSMs) to the location estimation problem have provided a means to incorporate spatial errors when characterising animal movements. The predominant platform for collecting satellite telemetry data on free-ranging animals, Service Argos, recently provided an alternative Doppler location estimation algorithm that is purported to be more accurate and generate a greater number of locations that its predecessor. We provide a comprehensive assessment of this new estimation process performance on data from free-ranging animals relative to concurrently collected Fastloc GPS data. Additionally, we test the efficacy of three readily-available SSM in predicting the movement of two focal animals. Raw Argos location estimates generated by the new algorithm were greatly improved compared to the old system. Approximately twice as many Argos locations were derived compared to GPS on the devices used. Root Mean Square Errors (RMSE) for each optimal SSM were less than 4.25 km with some producing RMSE of less than 2.50 km. Differences in the biological plausibility of the tracks between the two focal animals used to investigate the utility of SSM highlights the importance of considering animal behaviour in movement studies. The ability to reprocess Argos data collected since 2008 with the new algorithm should permit questions of animal movement to be revisited at a finer resolution.

  19. N Reactor

    Data.gov (United States)

    Federal Laboratory Consortium — The last of Hanfordqaodmasdkwaspemas7ajkqlsmdqpakldnzsdflss nine plutonium production reactors to be built was the N Reactor.This reactor was called a dual purpose...

  20. On the nature of the Madagascar dipoles: An analysis from Argo profiling floats and altimetry measurements

    Science.gov (United States)

    Aguiar-González, Borja; Ponsoni, Leandro; Ridderinkhof, Herman; de Ruijter, Will P. M.; Maas, Leo R. M.

    2016-04-01

    The South East Madagascar Current (SEMC) flows poleward along the eastern coast of Madagascar as a western boundary current which further south provides some of the source waters of the Agulhas Current, either directly or in the form of eddies. We investigate the region of dipole formation south of Madagascar combining vertical T/S profiles from Argo floats, altimetry measurements and an existing eddy detection algorithm. Results from our analysis show that the dipole consists of an anticyclonic intrathermocline eddy (ITE) formed on its southern flank and a cyclonic ITE formed on its northern flank. Both lobes of the dipole exhibit similar T/S properties throughout the water column, although vertically shifted within the thermocline depending on its nature: upward in a cyclonic ITE and downward in an anticyclonic ITE. A subsurface salinity maximum of about 35.5 psu characterizes the upper layers with Subtropical Surface Water (STSW). At intermediate levels, a well defined path of South Indian Central Water (SICW) extends throughout the water column up to reach a minimum in salinity of 34.5 psu, corresponding to Antarctic Intermediate Water (AAIW). Below, at deep layers, the North Atlantic Deep Water (NADW) is found. The intrathermocline nature of the Madagascar dipoles has not been previously reported and represents an important feature to be considered when assessing the heat and salt fluxes driven by eddy movement and contributing to the Agulhas Current. Unlike surface eddies, intrathermocline eddies strongly influence the intermediate/deeper layers in the oceans and, hence, may have a larger contribution in the spreading rates and pathways of water masses. Because the intrathermocline nature of eddies is invisible to altimetry measurements, these results stress the importance of combining altimetry with historical records of Argo profiles which uncover eddy dynamics below the sea surface. Lastly, we further investigate from altimetry the area of dipole formation

  1. Observations of new western Mediterranean deep water formation using Argo floats 2004–2006

    Directory of Open Access Journals (Sweden)

    K. Stansfield

    2008-05-01

    Full Text Available The deep convection that occurs in the western basin of the Mediterranean Sea was investigated using Argo float data over two consecutive winters in 2004–2005 and 2005–2006. The results showed deep mixed layers reaching 2000 m in surprising locations, namely the eastern Catalan subbasin (39.785° N, 4.845° E and the western Ligurian subbasin (43.392° N, 7.765° E. Subsequently, new deep water was formed in March of 2005 and 2006 with θ=12.89–12.92°C, S=38.48–38.49 and σθ=29.113 kg m−3. The deep water produced in the Ligurian subbasin during 2006 was more saline, warmer and denser than any historical observations of western Mediterranean deep water. The results show S, θ and σθ in the western Mediterranean deep water are higher than 1990s values, with a salinity increase of 1.5×10−3 yr−1, a temperature increase of 3.6×10−3 °C yr−1 and a density increase of 4.0×10−4 kg m−3 yr−1 apparent from a dataset of western Mediterranean deep water properties spanning 1955–2006.

  2. The upper ocean response to tropical cyclones in the northwestern Pacific analyzed with Argo data

    Institute of Scientific and Technical Information of China (English)

    LIU Zenghong; XU Jianping; ZHU Bokang; SUN Chaohui; ZHANG Lifeng

    2007-01-01

    A large number of autonomous profiling floats deployed in global oceans have provided abundant temperature and salinity profiles of the upper ocean. Many floats occasionally profile observations during the passage of tropical cyclones. These in-situ observations are valuable and useful in studying the ocean's response to tropical cyclones, which are rarely observed due to harsh weather conditions. In this paper, the upper ocean response to the tropical cyclones in the northwestern Pacific during 2000-2005 is analyzed and discussed based on the data from Argo profiling floats. Results suggest that the passage of tropical cyclones caused the deepening of mixed layer depth (MLD), cooling of mixed layer temperature (MLT), and freshening of mixed layer salinity (MLS). The change in MLT is negatively correlated to wind speed. The cooling of the MLT extended for 50-150 km on the right side of the cyclone track. The change of MLS is almost symmetrical in distribution on both sides of the track, and the change of MLD is negatively correlated to pre-cyclone initial MLD.

  3. Measurement of the Cosmic Ray Energy Spectrum with ARGO-YBJ

    CERN Document Server

    ,

    2014-01-01

    The ARGO-YBJ detector, located at high altitude in the Cosmic Ray Observatory of Yangbajing in Tibet (4300 m asl, about 600 g/cm2 of atmospheric depth) provides the opportunity to study, with unprecedented resolution, the cosmic ray physics in the primary energy region between 10^{12} and 10^{16} eV. The preliminary results of the measurement of all-particle and light-component (i.e. protons and helium) energy spectra between approximately 5 TeV and 5 PeV are reported and discussed. The study of such energy region is particularly interesting because not only it allows a better understanding of the so called 'knee' of the energy spectrum and of its origin, but also provides a powerful cross-check among very different experimental techniques. The comparison between direct measurements by balloons/satellites and the results by surface detectors, implying the knowledge of shower development in the atmosphere, also allows to test the hadronic interaction models currently used for understanding particle and cosmic ...

  4. Gamma-Ray Flares from Mrk421 in 2008 observed with the ARGO-YBJ experiment

    CERN Document Server

    Di Sciascio, G

    2009-01-01

    In 2008, the blazar Mrk421 entered in a very active phase and was one of the brightest sources in the sky at TeV energies, showing strong and frequent flaring. We searched for gamma-ray emission at energies E > 0.8 TeV during the whole 2008 with the ARGO-YBJ experiment, a full coverage air shower detector located at Yangbajing (4300 m a.s.l., Tibet, P.R. China). The observed signal is not constant and in correlation with X-ray measurements. The average emission, during the active period of the source, was about twice the Crab Nebula level, with an integral flux of (4.9$\\pm 2.0$)x 10$^{-11}$ photons cm$^{-2}$ s$^{-1}$ for E$_{\\gamma}$ >1 TeV. This paper concentrates on 2008 June when the Mrk421 flaring activity has been studied from optical to 100 MeV gamma rays, and only partially up to TeV energies, since the moonlight hampered the Cherenkov telescope observations after 8 June. Our data complete these observations, with the detection of a second flare of intensity of about 7 Crab units on June 11-13, with a ...

  5. Assessment of Global Oceanic Net Freshwater Flux Products Using Argo Salinity Observations

    Science.gov (United States)

    Ren, L.; Arkin, P. A.; Hackert, E. C.; Busalacchi, A. J.

    2012-12-01

    The annual mean global upper ocean salt budget is investigated using the Argo profiling float data from 2006 to 2011, which provides a way to estimate the annual mean oceanic evaporation and precipitation (E-P) from the ocean salinity. Employing this "ocean rain gauge" concept, E-P estimated from the salt budget is compared with the various satellite based oceanic precipitation and evaporation observational products. In this study, twelve sets of E-P from the evaporation and precipitation products including the precipitation datasets GPCP, CMAP and TRMM and the evaporation datasets OAFlux, GSSTF2b, IFREMER and RSS are compared to the E-P estimated from the salinity. We will describe the spatial patterns of the various E-P products derived from the satellite based data sets and compare these patterns to those derived from the oceanic salinity on the annual mean time scale. We will also examine time series of near-global integrated E-P derived from satellite products and compare them to time series based on oceanic salinity observations as well as continental discharge. This intercomparison of independently derived estimates of fresh water flux at the ocean surface will improve our understanding of errors in remotely sensed estimates of evaporation and precipitation.

  6. Reactor Physics

    Energy Technology Data Exchange (ETDEWEB)

    Ait Abderrahim, A

    2001-04-01

    The Reactor Physics and MYRRHA Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis of reactor fuel. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2000 are summarised.

  7. Assessing performance of Bayesian state-space models fit to Argos satellite telemetry locations processed with Kalman filtering.

    Science.gov (United States)

    Silva, Mónica A; Jonsen, Ian; Russell, Deborah J F; Prieto, Rui; Thompson, Dave; Baumgartner, Mark F

    2014-01-01

    Argos recently implemented a new algorithm to calculate locations of satellite-tracked animals that uses a Kalman filter (KF). The KF algorithm is reported to increase the number and accuracy of estimated positions over the traditional Least Squares (LS) algorithm, with potential advantages to the application of state-space methods to model animal movement data. We tested the performance of two Bayesian state-space models (SSMs) fitted to satellite tracking data processed with KF algorithm. Tracks from 7 harbour seals (Phoca vitulina) tagged with ARGOS satellite transmitters equipped with Fastloc GPS loggers were used to calculate the error of locations estimated from SSMs fitted to KF and LS data, by comparing those to "true" GPS locations. Data on 6 fin whales (Balaenoptera physalus) were used to investigate consistency in movement parameters, location and behavioural states estimated by switching state-space models (SSSM) fitted to data derived from KF and LS methods. The model fit to KF locations improved the accuracy of seal trips by 27% over the LS model. 82% of locations predicted from the KF model and 73% of locations from the LS model were GPS position. Uncertainty in KF model estimates (5.6 ± 5.6 km) was nearly half that of LS estimates (11.6 ± 8.4 km). Accuracy of KF and LS modelled locations was sensitive to precision but not to observation frequency or temporal resolution of raw Argos data. On average, 88% of whale locations estimated by KF models fell within the 95% probability ellipse of paired locations from LS models. Precision of KF locations for whales was generally higher. Whales' behavioural mode inferred by KF models matched the classification from LS models in 94% of the cases. State-space models fit to KF data can improve spatial accuracy of location estimates over LS models and produce equally reliable behavioural estimates. PMID:24651252

  8. Assessing performance of Bayesian state-space models fit to Argos satellite telemetry locations processed with Kalman filtering.

    Directory of Open Access Journals (Sweden)

    Mónica A Silva

    Full Text Available Argos recently implemented a new algorithm to calculate locations of satellite-tracked animals that uses a Kalman filter (KF. The KF algorithm is reported to increase the number and accuracy of estimated positions over the traditional Least Squares (LS algorithm, with potential advantages to the application of state-space methods to model animal movement data. We tested the performance of two Bayesian state-space models (SSMs fitted to satellite tracking data processed with KF algorithm. Tracks from 7 harbour seals (Phoca vitulina tagged with ARGOS satellite transmitters equipped with Fastloc GPS loggers were used to calculate the error of locations estimated from SSMs fitted to KF and LS data, by comparing those to "true" GPS locations. Data on 6 fin whales (Balaenoptera physalus were used to investigate consistency in movement parameters, location and behavioural states estimated by switching state-space models (SSSM fitted to data derived from KF and LS methods. The model fit to KF locations improved the accuracy of seal trips by 27% over the LS model. 82% of locations predicted from the KF model and 73% of locations from the LS model were <5 km from the corresponding interpolated GPS position. Uncertainty in KF model estimates (5.6 ± 5.6 km was nearly half that of LS estimates (11.6 ± 8.4 km. Accuracy of KF and LS modelled locations was sensitive to precision but not to observation frequency or temporal resolution of raw Argos data. On average, 88% of whale locations estimated by KF models fell within the 95% probability ellipse of paired locations from LS models. Precision of KF locations for whales was generally higher. Whales' behavioural mode inferred by KF models matched the classification from LS models in 94% of the cases. State-space models fit to KF data can improve spatial accuracy of location estimates over LS models and produce equally reliable behavioural estimates.

  9. Reactor safeguards

    CERN Document Server

    Russell, Charles R

    2013-01-01

    Reactor Safeguards provides information for all who are interested in the subject of reactor safeguards. Much of the material is descriptive although some sections are written for the engineer or physicist directly concerned with hazards analysis or site selection problems. The book opens with an introductory chapter on radiation hazards, the construction of nuclear reactors, safety issues, and the operation of nuclear reactors. This is followed by separate chapters that discuss radioactive materials, reactor kinetics, control and safety systems, containment, safety features for water reactor

  10. Reactor operation

    CERN Document Server

    Shaw, J

    2013-01-01

    Reactor Operation covers the theoretical aspects and design information of nuclear reactors. This book is composed of nine chapters that also consider their control, calibration, and experimentation.The opening chapters present the general problems of reactor operation and the principles of reactor control and operation. The succeeding chapters deal with the instrumentation, start-up, pre-commissioning, and physical experiments of nuclear reactors. The remaining chapters are devoted to the control rod calibrations and temperature coefficient measurements in the reactor. These chapters also exp

  11. Calibration of the RPC charge readout in the ARGO-YBJ experiment with the iso-gradient method

    International Nuclear Information System (INIS)

    The ARGO-YBJ experiment is a full coverage array of Resistive Plate Chambers (RPCs) with an active area of 5800 m2. In order to eliminate the response difference of the charge readout from the RPCs, a calibration procedure is carried out with the iso-gradient method. This method also allows the extension of the absolute calibration with the muon telescope including scintillation detectors to all the RPCs in the array. The overall systematic uncertainty in measurements of the number of particles by the RPCs is 10.7%. In general, the method gives results consistent with those from a totally different approach also used in the experiment

  12. Revision of deposition and weathering parameters for the ingestion dose module (ECOSYS) of the ARGOS and RODOS decision support systems

    DEFF Research Database (Denmark)

    Andersson, Kasper Grann; Nielsen, Sven Poul; Thørring, Håvard;

    2011-01-01

    The ECOSYS model is the ingestion dose model integrated in the ARGOS and RODOS decision support systems for nuclear emergency management. The parameters used in this model have however not been updated in recent years, where the level of knowledge on various environmental processes has increased...... considerably. A Nordic work group has carried out a series of evaluations of the general validity of current ECOSYS default parameters. This paper specifically discusses the parameter revisions required with respect to the modelling of deposition and natural weathering of contaminants on agricultural crops...

  13. Measurement of the cosmic ray all-particle and light-component energy spectra with the ARGO-YBJ experiment

    Directory of Open Access Journals (Sweden)

    De Mitri I.

    2015-01-01

    Full Text Available The ARGO-YBJ detector, located at high altitude in the Cosmic Ray Observatory of YangBaJing in Tibet (4300 m asl, about 600 g/cm2 of atmospheric depth provides the opportunity for the study, with unprecedented resolution, of cosmic ray physics in the primary energy region between 1012 and 1016 eV. Preliminary results of the measurements of the all-particle and light-component (i.e. protons and helium energy spectra between approximately 5 TeV and 5 PeV are reported and discussed.

  14. Experimental Research on Atmospheric Electric Field and Extensive Air Shower Particle Increasing During Thunderstorms with ARGO-YBJ

    Institute of Scientific and Technical Information of China (English)

    XU Bin; ZHANG Ying; JIA Huan-Yu

    2008-01-01

    From April lst to August 14th, 2006, thunderstorms had been recorded at Yangbajing Cosmic Ray Observatory by ARGO-YBJ experiment. This paper analyzed the correlation between atmospheric electric field (AEF) and "scaler mode" counting rate during thunderstorm. Counting rates of multiplicities n = 1,2 were found to have a large increase ( from 1.02% to 9.03% ), while there was few or no changes in those of multiplicities n =3 and n≥4 during the thunderstorms. The counts of different multiplicities had different feedbacks on the violent change of AEF, which showed that their energy and most components were distinguishing.

  15. Sistema de adquisición, almacenamiento y distribución de datos con sistema ARGOS

    OpenAIRE

    Pérez López, Fernando

    2011-01-01

    Proyecto Fin de Carrera del Área de Redes de Computadores de la titulación de Ingeniería Informática. El proyecto versa sobre el desarrollo de un sistema automático de descarga, distribución de datos y transformación de datos de boyas con el sistema ARGOS, así como una aplicación móvil para el sistema operativo móvil iOS, para su uso en dispositivos móviles iPhone.

  16. BIO ARGO floats: tools for operational monitoring of the Black Sea

    Science.gov (United States)

    Palazov, Atanas; Slabakova, Violeta; Peneva, Elisaveta; Stanev, Emil

    2014-05-01

    The assessment of ecological status in the context of the Water Framework Directive (WFD) and Marine Strategy Framework Directive (MSFD) requires comprehensive knowledge and understanding of the physical and biogeochemical processes that determine the functioning of marine ecosystems. One of the main challenges however is the need of data with frequency relevant to the spatial and temporal scales of the ecological processes. The majority of in situ observations that are commonly used for ecological monitoring of the Black Sea are generally based on near-shore monitoring programs or irregular oceanographic cruises that provide either non-synoptic, coarse resolution realizations of large scale processes or detailed, but time and site specific snapshots of local features. These gaps can be filled by two independent sources: satellite observation and profiling floats. In fact satellite ocean color sensors allows for determination at synoptic scale of water quality parameters through its absorption properties. However the satellite ocean color methods have a number of limitations such as: measurements can only be made during daylight hours; require cloud-free conditions and are sensitive to atmospheric aerosols; provide information only for the upper layer of the ocean (approximately the depth of 10% incident light); algorithms developed for global applications are a source of large uncertainties in the marginal seas and costal areas. These constrains of the optical remote sensing observations can be avoided by using miniature biogeochemical sensors and autonomous platforms that offer remarkable perspectives for observing the "biological" ocean, notably at critical spatiotemporal scales which have been out of reach until recently (Claustre et al., 2010). In the frame of "E-AIMS: Euro-Argo Improvements for the GMES marine Service" 7 EC FP project two Bio Argo floats were deployed in the Black Sea. Beside the traditionally CTD the floats were equipped with biogeochemical

  17. 基于海温参数模型推算Argo表层温度%Estimation of Argo sea subsurface temperature based on a thermal parametric model

    Institute of Scientific and Technical Information of China (English)

    张春玲; 许建平; 鲍献文; 王振峰; 刘增宏

    2014-01-01

    Argo has become an important part of the global ocean observation system. While, due to the lack of sea surface measurements, application of the Argo data still has some limitations. Based on a simple thermal parametric model,the relationship between sea surface temperature and subsurface temperature was constructed in this paper by the thermal parameters calculated from Argo profile data and WOA09 climatic data. And then sea surface temperature was estimated by Argo subsurface data in the Pacific Ocean. Among them, the thermal parameters were calculated by the maximum angle method. The novel objective method produced the more accurate thermal parameters than those by the iterative technique used in previous studies, such as mixed layer depth, thermocline temperature gradient, thermocline bottom depth and so on. Compared with the SST extrapolated from the traditional method and retrieved from satellite SST,the RMSEs between the estimated Argo surface temperature and the observed GTSPP or Argo NST have been significantly reduced;the correlation coefficient between estimation result and in situ observation was larger as well. The Argo surface temperature estimated by the thermal parametric model in the Pacific Ocean was theoretically proved to be reliable through correlation analysis. This study made up for the lacking of surface observation in Argo. It provided a new way to establish complete Argo data sets.%Argo浮标观测已成为全球海洋观测系统的重要支柱,但因缺乏表层观测,使得Argo观测资料在海洋和大气研究中的应用仍有一定的局限性。基于一个简化的海洋温度参数模型,由Argo剖面观测及气候态数据所确定的垂向海洋温度参数,得到表层与次表层温度的函数关系,进而利用太平洋海域的Argo次表层温度数据来推算表层温度场。其中,海温参数模型的相关参数采用最大角度法求得,利用此方法得到的混合层深度,温跃层梯度,

  18. Research reactors

    International Nuclear Information System (INIS)

    This article proposes an overview of research reactors, i.e. nuclear reactors of less than 100 MW. Generally, these reactors are used as neutron generators for basic research in matter sciences and for technological research as a support to power reactors. The author proposes an overview of the general design of research reactors in terms of core size, of number of fissions, of neutron flow, of neutron space distribution. He outlines that this design is a compromise between a compact enough core, a sufficient experiment volume, and high enough power densities without affecting neutron performance or its experimental use. The author evokes the safety framework (same regulations as for power reactors, more constraining measures after Fukushima, international bodies). He presents the main characteristics and operation of the two families which represent almost all research reactors; firstly, heavy water reactors (photos, drawings and figures illustrate different examples); and secondly light water moderated and cooled reactors with a distinction between open core pool reactors like Melusine and Triton, pool reactors with containment, experimental fast breeder reactors (Rapsodie, the Russian BOR 60, the Chinese CEFR). The author describes the main uses of research reactors: basic research, applied and technological research, safety tests, production of radio-isotopes for medicine and industry, analysis of elements present under the form of traces at very low concentrations, non destructive testing, doping of silicon mono-crystalline ingots. The author then discusses the relationship between research reactors and non proliferation, and finally evokes perspectives (decrease of the number of research reactors in the world, the Jules Horowitz project)

  19. Reactor physics and reactor computations

    International Nuclear Information System (INIS)

    Mathematical methods and computer calculations for nuclear and thermonuclear reactor kinetics, reactor physics, neutron transport theory, core lattice parameters, waste treatment by transmutation, breeding, nuclear and thermonuclear fuels are the main interests of the conference

  20. Comparison of Data From Far Ultraviolet Limb Scanning and Imaging Instrumentation Aboard the Advanced Research and Global Observation Satellite (ARGOS)

    Science.gov (United States)

    Walker, P. W.; Carruthers, G. R.; Dymond, K. F.; Finch, M. A.; McDonald, S. E.; Nicholas, A. C.; Thonnard, S. E.; Budzien, S. A.; McCoy, R. P.

    2001-05-01

    The ARGOS satellite includes two Naval Research Laboratory experiments that monitor naturally occurring far ultraviolet emissions in the Earth's upper atmosphere. Coincident observations between these two instruments, the Global Imaging Monitor of the Ionosphere (GIMI) and the Low Resolution Airglow and Auroral Spectrograph (LORAAS), have been obtained. The GIMI instrument produces 9 ° x 9 ° limb images with passband coverage between 131 and 200 nm. The LORAAS instrument provides the spectral distribution from 80 to 170 nm for 2.4 ° x 17 ° field of regard. The two instruments are coaligned aboard the spacecraft, aft-looking in the orbital plane. Preliminary comparisons of observations obtained from the imaging and scanning instruments under quiet geomagnetic conditions are reported, including irradiances and spectral distributions. By combining the GIMI data with that from LORAAS, the study of the dynamics of the ionosphere can be expanded to investigate both horizontal and vertical distrubutions and their variances. The improved capability can extend to the study of active periods with highly variable and disturbed ionospheres, and examples are discussed from data acquired during periods of high geomagnetic activity. These results provide the first direct comparison between near simultaneous limb scans and images from ARGOS, and show promise as a validation technique to improve capabilities for the study of ionospheric variability.

  1. Implementation of position assimilation for ARGO floats in a realistic Mediterranean Sea OPA model and twin experiment testing

    Directory of Open Access Journals (Sweden)

    V. Taillandier

    2006-05-01

    Full Text Available In this paper, a Lagrangian assimilation method is presented and implemented in a realistic OPA OGCM with the goal of providing an assessment of the assimilation of realistic Argo float position data. We focus on an application in the Mediterranean Sea, where in the framework of the MFSTEP project an array of Argo floats have been deployed with parking depth at 350 m and sampling interval of 5 days. In order to quantitatively test the method, the ''twin experiment'' approach is followed and synthetic trajectories are considered. The method is first tested using ''perfect'' data, i.e. without shear drift errors and with relatively high coverage. Results show that the assimilation is effective, correcting the velocity field at the parking depth, as well as the velocity profiles and the geostrophically adjusted mass field. We then consider the impact of realistic datasets, which are spatially sparse and characterized by shear drift errors. Such data provide a limited global correction of the model state, but they efficiently act on the location, intensity and shape of the described mesoscale structures of the intermediate circulation.

  2. An Ensemble Recentering Kalman Filter with an Application to Argo Temperature Data Assimilation into the NASA GEOS-5 Coupled Model

    Science.gov (United States)

    Keppenne, Christian L.

    2013-01-01

    A two-step ensemble recentering Kalman filter (ERKF) analysis scheme is introduced. The algorithm consists of a recentering step followed by an ensemble Kalman filter (EnKF) analysis step. The recentering step is formulated such as to adjust the prior distribution of an ensemble of model states so that the deviations of individual samples from the sample mean are unchanged but the original sample mean is shifted to the prior position of the most likely particle, where the likelihood of each particle is measured in terms of closeness to a chosen subset of the observations. The computational cost of the ERKF is essentially the same as that of a same size EnKF. The ERKF is applied to the assimilation of Argo temperature profiles into the OGCM component of an ensemble of NASA GEOS-5 coupled models. Unassimilated Argo salt data are used for validation. A surprisingly small number (16) of model trajectories is sufficient to significantly improve model estimates of salinity over estimates from an ensemble run without assimilation. The two-step algorithm also performs better than the EnKF although its performance is degraded in poorly observed regions.

  3. Observation of TeV gamma rays from the Cygnus region with the ARGO-YBJ experiment

    CERN Document Server

    Bartoli, B; Bi, X J; Bleve, C; Bolognino, I; Branchini, P; Budano, A; Melcarne, A K Calabrese; Camarri, P; Cao, Z; Cardarelli, R; Catalanotti, S; Cattaneo, C; Chen, S Z; Chen, T L; Chen, Y; Creti, P; Cui, S W; Dai, B Z; Staiti, G D'Alí; Danzengluobu,; Dattoli, M; De Mitri, I; Piazzoli, B D'Ettorre; Di Girolamo, T; Ding, X H; Di Sciascio, G; Feng, C F; Feng, Zhaoyang; Feng, Zhenyong; Galeazzi, F; Giroletti, E; Gou, Q B; Guo, Y Q; He, H H; Hu, Haibing; Hu, Hongbo; Huang, Q; Iacovacci, M; Iuppa, R; James, I; Jia, H Y; Labaciren,; Li, H J; Li, J Y; Li, X X; Liguori, G; Liu, C; Liu, C Q; Liu, J; Liu, M Y; Lu, H; Ma, L L; Ma, X H; Mancarella, G; Mari, S M; Marsella, G; Martello, D; Mastroianni, S; Montini, P; Ning, C C; Pagliaro, A; Panareo, M; Panico, B; Perrone, L; Pistilli, P; Ruggieri, F; Salvini, P; Santonico, R; Shen, P R; Sheng, X D; Shi, F; Stanescu, C; Surdo, A; Tan, Y H; Vallania, P; Vernetto, S; Vigorito, C; Wang, B; Wang, H; Wu, C Y; Wu, H R; Xu, B; Xue, L; Yang, Q Y; Yang, X C; Yao, Z G; Yuan, A F; Zha, M; Zhang, H M; Zhang, Jilong; Zhang, Jianli; Zhang, L; Zhang, P; Zhang, X Y; Zhang, Y; Zhao, J; Zhaxiciren,; Zhaxisangzhu,; Zhou, X X; Zhu, F R; Zhu, Q Q; Zizzi, G

    2012-01-01

    We report the observation of TeV gamma-rays from the Cygnus region using the ARGO-YBJ data collected from 2007 November to 2011 August. Several TeV sources are located in this region including the two bright extended MGRO J2019+37 and MGRO J2031+41. According to the Milagro data set, at 20 TeV MGRO J2019+37 is the most significant source apart from the Crab Nebula. No signal from MGRO J2019+37 is detected by the ARGO-YBJ experiment, and the derived flux upper limits at 90% confidence level for all the events above 600 GeV with medium energy of 3 TeV are lower than the Milagro flux, implying that the source might be variable and hard to be identified as a pulsar wind nebula. The only statistically significant (6.4 standard deviations) gamma-ray signal is found from MGRO J2031+41, with a flux consistent with the measurement by Milagro.

  4. Long-term monitoring of the TeV emission from Mrk 421 with the ARGO-YBJ experiment

    CERN Document Server

    Bartoli, B; Bi, X J; Bleve, C; Bolognino, I; Branchini, P; Budano, A; Melcarne, A K Calabrese; Camarri, P; Cao, Z; Cappa, A; Cardarelli, R; Catalanotti, S; Cattaneo, C; Celio, P; Chen, S Z; Chen, T L; Chen, Y; Creti, P; Cui, S W; Dai, B Z; Staiti, G D'Alí; Danzengluobu,; Dattoli, M; De Mitri, I; Piazzoli, B D'Ettorre; Di Girolamo, T; Ding, X H; Di Sciascio, G; Feng, C F; Feng, Zhaoyang; Feng, Zhenyong; Galeazzi, F; Galeotti, P; Giroletti, E; Gou, Q B; Guo, Y Q; He, H H; Hu, Haibing; Hu, Hongbo; Huang, Q; Iacovacci, M; Iuppa, R; James, I; Jia, H Y; Labaciren,; Li, H J; Li, J Y; Li, X X; Liguori, G; Liu, C; Liu, C Q; Liu, J; Liu, M Y; Lu, H; Ma, X H; Mancarella, G; Mari, S M; Marsella, G; Martello, D; Mastroianni, S; Montini, P; Ning, C C; Pagliaro, A; Panareo, M; Panico, B; Perrone, L; Pistilli, P; Qu, X B; Rossi, E; Ruggieri, F; Salvini, P; Santonico, R; Shen, P R; Sheng, X D; Shi, F; Stanescu, C; Surdo, A; Tan, Y H; Vallania, P; Vernetto, S; Vigorito, C; Wang, B; Wang, H; Wu, C Y; Wu, H R; Xu, B; Xue, L; Yan, Y X; Yang, Q Y; Yang, X C; Yao, Z G; Yuan, A F; Zha, M; Zhang, H M; Zhang, Jilong; Zhang, Jianli; Zhang, L; Zhang, P; Zhang, X Y; Zhang, Y; Zhaxiciren,; Zhaxisangzhu,; Zhou, X X; Zhu, F R; Zhu, Q Q; Zizzi, G

    2011-01-01

    ARGO-YBJ is an air shower detector array with a fully covered layer of resistive plate chambers. It is operated with a high duty cycle and a large field of view. It continuously monitors the northern sky at energies above 0.3 TeV. In this paper, we report a long-term monitoring of Mrk 421 over the period from 2007 November to 2010 February. This source was observed by the satellite-borne experiments Rossi X-ray Timing Explorer and Swift in the X-ray band. Mrk 421 was especially active in the first half of 2008. Many flares are observed in both X-ray and gamma-ray bands simultaneously. The gamma-ray flux observed by ARGO-YBJ has a clear correlation with the X-ray flux. No lag between the X-ray and gamma-ray photons longer than 1 day is found. The evolution of the spectral energy distribution is investigated by measuring spectral indices at four different flux levels. Hardening of the spectra is observed in both X-ray and gamma-ray bands. The gamma-ray flux increases quadratically with the simultaneously measur...

  5. Analyses of phenotype and ARGOS and ASY1 expression in a ploidy Chinese cabbage series derived from one haploid.

    Science.gov (United States)

    Gu, Ai Xia; Zhao, Jian Jun; Li, Li Min; Wang, Yan Hua; Zhao, Yu Jing; Hua, Fan; Xu, Yuan Chao; Shen, Shu Xing

    2016-03-01

    The aim of this research was to improve our understanding of how ploidy level influences phenotype and gene expression in Chinese cabbage (Brassica rapa L. ssp. pekinensis). Haploid plants (2n = 10) was induced by 0.2% colchicine to produce diploid (2n = 20) and tetraploid plants (2n = 40). The aneuploid (2n = 24) was also obtained by hybridization between diploid plants as the female and tetraploid plants. The ploidy levels of all plants were identified through chromosome counts and flow cytometry. Leaves and petals became larger as the ploidy level increased from haploid to diploid, and from aneuploid to tetraploid. Similarly, expression of ARGOS was regulated by genome size, increasing in parallel with the level of ploidy. Among the four ploidy types, expression was stronger in the floral buds than in the leaves. Expression by ASY1 also differed according to ploidy level, being highest in diploid plants, followed in order by tetraploids. Expression was similar between haploids and aneuploids at two stages-prior to and after meiosis-but was higher in the haploids during meiosis. When buds were compared within the same ploidy type at different stages, ASY1 expression was obviously higher during meiosis than either before or after. Our study demonstrated the generation and phenotype of a ploidy Chinese cabbage series derived from one haploid. Expression of genes ARGOS and ASY1 were modulated by genome size in this ploidy series, and the regulated patterns of the two genes was different. PMID:27162487

  6. Direct measurements of surface and mid-depth circulation in the Shikoku Basin by Argo profiling floats

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hui; GUO Peifang; XU Jianping; SHI Maochong

    2007-01-01

    The circulation in the Shikoku Basin plays a very important role in the pathway of the Kuroshio and the water exchange in the subtropical gyre in the North Pacific Ocean. The Argo profiling floats deployed in the Shikoku Basin are used to study the circulations and water masses in the basin. The trajectories and parking depth velocity fields derived from all Argo floats show an anticyclonic circulation at 2 000 m in the Shikoku Basin. There are inhanced eddy activities in the Shikoku Basin, which have large influence on the Shikoku Basin circulation patterns. The characteristics of temperature - salinity curves indicate that there are North Pacific Ocean tropical water (NPTW), North Pacific Ocean subtropical mode water (NPSTMW) and North Pacific Ocean intermediate water (NPIW) in the Shikoku Basin. The NPTW is only exists south of 32°N. In the middle part of the basin, which is 28°~31°N,133°~135°E, there is a confluence region. Water masses coming from the Kuroshio mix with the water in the Shikoku Basin.

  7. Interpretation of Postmodern Feminism in Argo%《逃离德黑兰》的后现代女性主义解读

    Institute of Scientific and Technical Information of China (English)

    张乔源

    2015-01-01

    作为一部惊心动魄、扣人心弦的政治大片,《逃离德黑兰》充斥着浓烈的美国式个人英雄主义和爱国主义。然而爱国主义主旋律的背后却也隐藏着不可磨灭的男权印记。基于后现代女性主义,从男性话语霸权、两性二元对立思维模式以及女性内部的异化和压迫等三个方面着手,分析《逃离德黑兰》中的男权色彩。%As one of the most impressive political films, Argo is filled with American individual heroism and patriotism.However, be-hind the cover of patriotism, Argo reflects the patriarchal society and male chauvinism.Based on Postmodern Feminism, this paper at-tempts to analyze Argo from the perspective of the discourse hegemony of male, gender dichotomy as well as the internal alienation and oppression of female, so as to reflect the patriarchy in Argo.

  8. Global representation of tropical cyclone-induced short-term ocean thermal changes using Argo data

    Science.gov (United States)

    Cheng, L.; Zhu, J.; Sriver, R. L.

    2015-09-01

    Argo floats are used to examine tropical cyclone (TC) induced ocean thermal changes on the global scale by comparing temperature profiles before and after TC passage. We present a footprint method that analyzes cross-track thermal responses along all storm tracks during the period 2004-2012. We combine the results into composite representations of the vertical structure of the average thermal response for two different categories: tropical storms/tropical depressions (TS/TD) and hurricanes. The two footprint composites are functions of three variables: cross-track distance, water depth and time relative to TC passage. We find that this footprint strategy captures the major features of the upper-ocean thermal response to TCs on timescales up to 20 days when compared against previous case study results using in situ measurements. On the global scale, TCs are responsible for 1.87 PW (11.05 W m-2) of heat transfer annually from the global ocean to the atmosphere during storm passage (0-3 days). Of this total, 1.05 ± 0.20 PW (4.80 ± 0.85 W m-2) is caused by TS/TD and 0.82 ± 0.21 PW (6.25 ± 1.5 W m-2) is caused by hurricanes. Our findings indicate that ocean heat loss by TCs may be a substantial missing piece of the global ocean heat budget. Changes in ocean heat content (OHC) after storm passage are estimated by analyzing the temperature anomalies during wake recovery following storm events (4-20 days after storm passage) relative to pre-storm conditions. Results indicate the global ocean experiences a 0.75 ± 0.25 PW (5.98 ± 2.1 W m-2) heat gain annually for hurricanes. In contrast, under TS/TD conditions, the ocean experiences 0.41 ± 0.21 PW (1.90 ± 0.96 W m-2) ocean heat loss, suggesting the overall oceanic thermal response is particularly sensitive to the intensity of the event. The ocean heat uptake caused by all storms during the restorative stage is 0.34 PW.

  9. Mesoscale variability of water masses in the Arabian Sea as revealed by ARGO floats

    Directory of Open Access Journals (Sweden)

    X. Carton

    2012-03-01

    Full Text Available By analysing ARGO float data over the last four years, a few aspects of the mesoscale variability of water masses in the Arabian Sea are described.

    The Red Sea Outflow Water (RSOW is concentrated in the Southwestern Gulf of Aden, in particular when a cyclonic gyre predominates in this region. Salinities of 36.5 and temperatures of 16 °C are found in this area at depths between 600 and 1000 m. RSOW is more dilute in the eastern part of the Gulf, where intense and relatively barotropic gyres mix it with Indian ocean Central Water. RSOW is also detected along the northeastern coast of Socotra, and fragments of RSOW are found between one and three degrees of latitude north of this island. In the whole Gulf of Aden, the correlation between the deep motions of the floats and the sea-level anomaly measured by altimetry is strong, at regional scale. The finer scale details of the float trajectories are not sampled by altimetry and are often related to the anomalous water masses that the floats encounter.

    The Persian Gulf Water (PGW is found in the float profiles near Ras ash Sharbatat (near 57° E, 18° N, again with 36.5 in salinity and about 18–19 °C in temperature. These observations were achieved in winter when the southwestward monsoon currents can advect PGW along the South Arabian coast. Fragments of PGW were also observed in the Arabian Sea between 18 and 20° N and 63 and 65° E in summer, showing that this water mass can escape the Gulf of Oman southeastward, during that season.

    Kinetic energy distributions of floats with respect to distance or angle share common features between the two regions (Gulf of Aden and Arabian Sea, in particular peaks at 30, 50 and 150 km scales and along the axis of monsoon currents. Hydrological measurements by floats are also influenced by the seasonal variations of PGW and RSOW in these regions.

  10. An upper ocean response to Typhoon Bolaven analyzed with Argo profiling floats

    Institute of Scientific and Technical Information of China (English)

    LIU Zenghong; XU Jianping; SUN Chaohui; WU Xiaofen

    2014-01-01

    In situ observations from Argo profiling floats combined with satellite retrieved SST and rain rate are used to investigate an upper ocean response to Typhoon Bolaven from 20 through 29 August 2012. After the passage of Typhoon Bolaven, the deepening of mixed layer depth (MLD), and the cooling of mixed layer temperature (MLT) were observed. The changes in mixed layer salinity (MLS) showed an equivalent number of increasing and decreasing because the typhoon-induced salinity changes in the mixed layer were influenced by precipi-tation, evaporation, turbulent mixing and upwelling of thermocline water. The deepening of the MLD and the cooling of the MLT indicated a significant rightward bias, whereas the MLS was freshened to the left side of the typhoon track and increased on the other side. Intensive temperature and salinity profiles observed by Iridium floats make it possible to view response processes in the upper ocean after the passage of a typhoon. The cooling in the near-surface and the warming in the subsurface were observed by two Iridium floats located to the left side of the cyclonic track during the development stage of the storm, beyond the radius of maxi-mum winds relative to the typhoon center. Water salinity increases at the base of the mixed layer and the top of the thermocline were the most obvious change observed by those two floats. On the right side of the track and near the typhoon center when the typhoon was intensified, the significant cooling from sea surface to a depth of 200×104 Pa, with the exception of the water at the top of the thermocline, was observed by the other Iridium float. Owing to the enhanced upwelling near the typhoon center, the water salinity in the near-surface increased noticeably. The heat pumping from the mixed layer into the thermocline induced by downwelling and the upwelling induced by the positive wind stress curl are the main causes for the different temperature and salinity variations on the different sides of the

  11. Variation of Indo-Pacific upper ocean heat content during 2001–2012 revealed by Argo

    Institute of Scientific and Technical Information of China (English)

    WU Xiaofen; LIU Zenghong; LIAO Guanghong; WU Lingjuan

    2015-01-01

    Understanding of the temporal variation of oceanic heat content (OHC) is of fundamental importance to the prediction of climate change and associated global meteorological phenomena. However, OHC characteristics in the Pacific and Indian oceans are not well understood. Based on in situ ocean temperature and salinity profiles mainly from the Argo program, we estimated the upper layer (0–750 m) OHC in the Indo-Pacific Ocean (40°S–40°N, 30°E–80°W). Spatial and temporal variability of OHC and its likely physical mechanisms are also analyzed. Climatic distributions of upper-layer OHC in the Indian and Pacific oceans have a similar saddle pattern in the subtropics, and the highest OHC value was in the northern Arabian Sea. However, OHC variabilities in the two oceans were different. OHC in the Pacific has an east-west see-saw pattern, which does not appear in the Indian Ocean. In the Indian Ocean, the largest change was around 10°S. The most interesting phenomenon is that, there was a long-term shift of OHC in the Indo-Pacific Ocean during 2001–2012. Such variation coincided with modulation of subsurface temperature/salinity. During 2001–2007, there was subsurface cooling (freshening) nearly the entire upper 400 m layer in the western Pacific and warming (salting) in the eastern Pacific. During 2008–2012, the thermocline deepened in the western Pacific but shoaled in the east. In the Indian Ocean, there was only cooling (upper 150 m only) and freshening (almost the entire upper 400 m) during 2001–2007. The thermocline deepened during 2008–2012 in the Indian Ocean. Such change appeared from the equator to off the equator and even to the subtropics (about 20°N/S) in the two oceans. This long-term change of subsurface temperature/salinity may have been caused by change of the wind field over the two oceans during 2001–2012, in turn modifying OHC.

  12. Reactor building

    International Nuclear Information System (INIS)

    The whole reactor building is accommodated in a shaft and is sealed level with the earth's surface by a building ceiling, which provides protection against penetration due to external effects. The building ceiling is supported on walls of the reactor building, which line the shaft and transfer the vertical components of forces to the foundations. The thickness of the walls is designed to withstand horizontal pressure waves in the floor. The building ceiling has an opening above the reactor, which must be closed by cover plates. Operating equipment for the reactor can be situated above the building ceiling. (orig./HP)

  13. Using GPS data to evaluate the accuracy of state-space methods for correction of Argos satellite telemetry error.

    Science.gov (United States)

    Patterson, Toey A; McConnell, Bernie J; Fedak, Mike A; Bravington, Mark V; Hindell, Mark A

    2010-01-01

    Recent studies have applied state-space models to satellite telemetry data in order to remove noise from raw location estimates and infer the true tracks of animals. However, while the resulting tracks may appear plausible, it is difficult to determine the accuracy of the estimated positions, especially for position estimates interpolated to times between satellite locations. In this study, we use data from two gray seals (Halichoerus grypus) carrying tags that transmitted Fastloc GPS positions via Argos satellites. This combination of Service Argos data and highly accurate GPS data allowed examination of the accuracy of state-space position estimates and their uncertainty derived from satellite telemetry data. After applying a speed filter to remove aberrant satellite telemetry locations, we fit a continuous-time Kalman filter to estimate the parameters of a random walk, used Kalman smoothing to infer positions at the times of the GPS measurements, and then compared the filtered telemetry estimates with the actual GPS measurements. We investigated the effect of varying maximum speed thresholds in the speed-filtering algorithm on the root mean-square error (RMSE) estimates and used minimum RMSE as a criterion to guide the final choice of speed threshold. The optimal speed thresholds differed between the two animals (1.1 m/s and 2.5 m/s) and retained 50% and 65% of the data for each seal. However, using a speed filter of 1.1 m/s resulted in very similar RMSE for both animals. For the two seals, the RMSE of the Kalman-filtered estimates of location were 5.9 and 12.76 km, respectively, and 75% of the modeled positions had errors less than 6.25 km and 11.7 km for each seal. Confidence interval coverage was close to correct at typical levels (80-95%), although it tended to be overly generous at smaller sizes. The reliability of uncertainty estimates was also affected by the chosen speed threshold. The combination of speed and Kalman filtering allows for effective

  14. Temperature and salinity profiles from CTD casts from the ARGOS and other PLATFORMS from a World-Wide Distribution in support of the Integrated Global Ocean Services System (IGOSS) from 01 November 1989 to 30 November 1989 (NODC Accession 8900297)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CTD and other data were collected from the ARGOS and other PLATFORMS in support of the Integrated Global Ocean Services System (IGOSS). Data were collected by US...

  15. Effects of interannual salinity variability on the dynamic height in the western equatorial Pacific as diagnosed by Argo

    Institute of Scientific and Technical Information of China (English)

    ZHENG Fei; WANG Hui; WAN Liying

    2015-01-01

    In this paper, interannual variations of the ocean dynamic height over the tropical Pacific are diagnosed using three-dimensional temperature and salinity fields from Argo profiles, with a focus on the effects of interannually varying salinity on the El Ni(n)o-Southern Oscillation (ENSO) evolutions. The diagnostic analyses clearly demonstrate a significant and large role that the salinity field plays in modulating the sea surface dynamic height (SSDH) in the western tropical Pacific. In particular, the contribution of the interannually varying salinity to the interannual variations in SSDH approximately equals to that of the interannually varying temperature. Over the western equatorial Pacific, the salinity variability was responsible for a 30% to 40% reduction in SSDH anomaly in opposition to the thermal build up in SSDH anomaly, providing an important contribution to modulating the seasonal-to-interannual evolution of the tropical Pacific Ocean and affecting the developing of ENSO events.

  16. Compact Reactor

    International Nuclear Information System (INIS)

    Weyl's Gauge Principle of 1929 has been used to establish Weyl's Quantum Principle (WQP) that requires that the Weyl scale factor should be unity. It has been shown that the WQP requires the following: quantum mechanics must be used to determine system states; the electrostatic potential must be non-singular and quantified; interactions between particles with different electric charges (i.e. electron and proton) do not obey Newton's Third Law at sub-nuclear separations, and nuclear particles may be much different than expected using the standard model. The above WQP requirements lead to a potential fusion reactor wherein deuterium nuclei are preferentially fused into helium nuclei. Because the deuterium nuclei are preferentially fused into helium nuclei at temperatures and energies lower than specified by the standard model there is no harmful radiation as a byproduct of this fusion process. Therefore, a reactor using this reaction does not need any shielding to contain such radiation. The energy released from each reaction and the absence of shielding makes the deuterium-plus-deuterium-to-helium (DDH) reactor very compact when compared to other reactors, both fission and fusion types. Moreover, the potential energy output per reactor weight and the absence of harmful radiation makes the DDH reactor an ideal candidate for space power. The logic is summarized by which the WQP requires the above conditions that make the prediction of DDH possible. The details of the DDH reaction will be presented along with the specifics of why the DDH reactor may be made to cause two deuterium nuclei to preferentially fuse to a helium nucleus. The presentation will also indicate the calculations needed to predict the reactor temperature as a function of fuel loading, reactor size, and desired output and will include the progress achieved to date

  17. NEUTRONIC REACTOR

    Science.gov (United States)

    Anderson, H.L.

    1960-09-20

    A nuclear reactor is described comprising fissionable material dispersed in graphite blocks, helium filling the voids of the blocks and the spaces therebetween, and means other than the helium in thermal conductive contact with the graphite for removing heat.

  18. NUCLEAR REACTOR

    Science.gov (United States)

    Miller, H.I.; Smith, R.C.

    1958-01-21

    This patent relates to nuclear reactors of the type which use a liquid fuel, such as a solution of uranyl sulfate in ordinary water which acts as the moderator. The reactor is comprised of a spherical vessel having a diameter of about 12 inches substantially surrounded by a reflector of beryllium oxide. Conventionnl control rods and safety rods are operated in slots in the reflector outside the vessel to control the operation of the reactor. An additional means for increasing the safety factor of the reactor by raising the ratio of delayed neutrons to prompt neutrons, is provided and consists of a soluble sulfate salt of beryllium dissolved in the liquid fuel in the proper proportion to obtain the result desired.

  19. Chemical Reactors.

    Science.gov (United States)

    Kenney, C. N.

    1980-01-01

    Describes a course, including content, reading list, and presentation on chemical reactors at Cambridge University, England. A brief comparison of chemical engineering education between the United States and England is also given. (JN)

  20. A new species in the genus Pseudorhyncomyia Peris, 1952 and the identity of P. deserticola Zumpt and Argo, 1978 (Diptera, Rhiniidae).

    Science.gov (United States)

    Rognes, Knut

    2013-01-01

    The genus Pseudorhyncomyia Peris, 1952 is re-described and shown to have two valid species: P. braunsi (Villeneuve, 1920) and P. aethiopica sp. nov. The latter is described on the basis of a single male specimen captured near Ado, Ethiopia, in 1953. Nominal species P. deserticola Zumpt and Argo, 1978 is transferred to Zumba Peris, 1951, where it is placed as a junior synonym of Z. antennalis (Villeneuve, 1929), syn. nov.

  1. Hydrodynamic features of the South Aegean Sea as derived from Argo T/S and dissolved oxygen profiles in the area

    Science.gov (United States)

    Kassis, Dimitris; Krasakopoulou, Evangelia; Korres, Gerasimos; Petihakis, George; Triantafyllou, George S.

    2016-09-01

    In this work, the hydrodynamic picture of the South Aegean Sea is examined through an analysis of recent measurements in its sub-basins, the Myrtoan and Cretan Sea. Both sub-basins play an important role in the water circulation, exchange, and formation processes that affect the dynamics of the whole Eastern Mediterranean. For the first time, Bio-Argo floats were deployed in the area under the Greek Argo Research Infrastructure coordination. The acquired profiles cover an almost 2-year period (November 2013-July 2015) and are compared with previous Argo profiles and the re-processed time-series data recorded from the E1-M3A POSEIDON observatory operating in the area since 2007. The spatio-temporal distribution of the physical and chemical properties in each sub-basin is examined. Dense water formation events are revealed in the northern part (Myrtoan), while the wider area can be characterized as pre-conditioned. In the Cretan basin, a strong inter-annual variability of the salinity field at intermediate and deep layers is observed that is associated with water exchange from its open boundaries. Furthermore, comparison of the dissolved oxygen (DO) distribution with physical water properties within both the mixed layer, and at greater depths, indicated that relatively high but still under-saturated DO values are more likely to be associated with convection events. Finally, an updated picture of the physical properties and the DO distribution is presented based on the last 5 years of measurements and the recent introduction of Bio-Argo floats with DO sensors in the area.

  2. NUCLEAR REACTOR

    Science.gov (United States)

    Anderson, C.R.

    1962-07-24

    A fluidized bed nuclear reactor and a method of operating such a reactor are described. In the design means are provided for flowing a liquid moderator upwardly through the center of a bed of pellets of a nentron-fissionable material at such a rate as to obtain particulate fluidization while constraining the lower pontion of the bed into a conical shape. A smooth circulation of particles rising in the center and falling at the outside of the bed is thereby established. (AEC)

  3. Nuclear reactor

    International Nuclear Information System (INIS)

    In order to reduce neutron embrittlement of the pressue vessel of an LWR, blanked off elements are fitted at the edge of the reactor core, with the same dimensions as the fuel elements. They are parallel to each other, and to the edge of the reactor taking the place of fuel rods, and are plates of neutron-absorbing material (stainless steel, boron steel, borated Al). (HP)

  4. Revision of deposition and weathering parameters for the ingestion dose module (ECOSYS) of the ARGOS and RODOS decision support systems

    International Nuclear Information System (INIS)

    The ECOSYS model is the ingestion dose model integrated in the ARGOS and RODOS decision support systems for nuclear emergency management. The parameters used in this model have however not been updated in recent years, where the level of knowledge on various environmental processes has increased considerably. A Nordic work group has carried out a series of evaluations of the general validity of current ECOSYS default parameters. This paper specifically discusses the parameter revisions required with respect to the modelling of deposition and natural weathering of contaminants on agricultural crops, to enable the trustworthy prognostic modelling that is essential to ensure justification and optimisation of countermeasure strategies. New modelling approaches are outlined, since it was found that current ECOSYS approaches for deposition and natural weathering could lead to large prognostic errors. - Highlights: → We examined concepts and parameters in the ECOSYS ingestion dose model. → Natural weathering and deposition processes were studied. → A series of revisions were recommended to users. → Order-of-magnitude errors can be avoided by using the new values.

  5. Origins and pathways of the subsurface and intermediate water masses of the Indonesian Throughflow derived from historical and Argo data

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yanhui; YU Xiaolin; WANG Fan

    2008-01-01

    On the basis of Argo data and historic temperature/salinity data from the World Ocean Database 2001(WOD01),origins and spreading pathways of the subsurface and intermediate water masses in the Indonesian Throughflow (ITF) region were discussed by analyzing distributions of salinity on representative isepycnal layers.Results were shown that,subsurface water mostly comes from the North Pacific Ocean while the intermediate water originates from both the North and South Pacific Ocean,even possibly from the Indian Ocean.Spreading through the Sulawesi Sea,the Makassar Strait,and the Flores Sea,the North Pacific subsurface water and the North Pacific Intermediate water dominate the western part of the Indonesian Archipelago.Furthermore as the depth increases,the features of the North Pacific sourced water masses become more obvious.In the eastern part of the waters,high sa-1inity South Pacific subsurface water is blocked by a strong salinity front between Halmahera and New Guinea.Intermediate water in the eastern interior region owns salinity higher than the North Pacific intermediate water and the antarctic intermediate water (AAIW),possibly coming from the vertical mixing between subsurface water and the AAIW from the Pacific Ocean,and possibly coming from the northward extending of the AAIW from the Indian Ocean as well.

  6. Objective mapping of Argo data in the Weddell Gyre: a gridded dataset of upper ocean water properties

    Directory of Open Access Journals (Sweden)

    K. A. Reeve

    2015-06-01

    Full Text Available The Weddell Gyre plays a crucial role in the modification of climate by advecting heat poleward to the Antarctic ice shelves and by regulating the density of water masses that feed the lowest limb of the global ocean overturning circulation. However, our understanding of Weddell Gyre water mass properties is limited to regions of data availability, primarily along the Prime Meridian. The aim of this paper is to provide a dataset of the upper water column properties of the entire Weddell Gyre. Objective mapping was applied to Argo float data in order to produce spatially gridded, time composite maps of temperature and salinity for fixed pressure levels ranging from 50 to 2000 dbar, as well as temperature, salinity and pressure at the level of the sub-surface temperature maximum. While the data are currently too limited to incorporate time into the gridded structure, the data are extensive enough to produce maps of the entire region across three time composite periods (2002–2005, 2006–2009 and 2010–2013, which can be used to determine how representative conclusions drawn from data collected along general RV transect lines are on a gyre scale perspective. The work presented here represents the technical prerequisite in addressing climatological research questions in forthcoming studies. These data sets are available in netCDF format at doi:10.1594/PANGAEA.842876.

  7. The Argo Simulation: I. Quenching of Massive Galaxies at High Redshift as a Result of Cosmological Starvation

    CERN Document Server

    Feldmann, Robert

    2014-01-01

    Observations show a prevalence of high redshift galaxies with large stellar masses and predominantly passive stellar populations. A variety of processes have been suggested that could reduce the star formation in such galaxies to observed levels, including quasar mode feedback, virial shock heating, or galactic winds driven by stellar feedback. However, the main quenching mechanisms have yet to be identified. Here we study the origin of star formation quenching using Argo, a cosmological zoom-in simulation that follows the evolution of a massive galaxy at $z\\geq{}2$. This simulation adopts the same sub-grid recipes of the Eris simulations, which have been shown to form realistic disk galaxies, and, in one version, adopts also a mass and spatial resolution identical to Eris. The resulting galaxy has properties consistent with those of observed, massive (M_* ~ 1e11 M_sun) galaxies at z~2 and with abundance matching predictions. Our models do not include AGN feedback indicating that supermassive black holes like...

  8. Quality Controlled Argo Profiling Float Oxygen Data: Open Source Sharing and Version Control Using IPython Notebooks on GitHub

    Science.gov (United States)

    Sakamoto, C.; McCann, M. P.; Plant, J. N.; Johnson, K. S.

    2015-12-01

    Profiling floats equipped with biogeochemical sensors are an ideal platform for observing the seasonal evolution of physical and chemical processes from the surface to the deep interior. As of August 2015, there have reportedly been 765 floats equipped with oxygen sensors with 363 currently active. Although new insights into oceanic biogeochemical processes have come from these data, the profiling oxygen data set has not been fully utilized because the dissolved oxygen data does not undergo QC procedures at the Argo data centers. The oxygen sensors on profiling floats have been demonstrated to produce highly stable and precise data over many months and years but only a small percentage have been verified with discrete samples taken at deployment to determine the sensor accuracy. Takeshita et al (2013) presented a climatology based quality control procedure utilizing the World Ocean Atlas 2009 (WOA09). We used a straightforward approach mentioned in their paper to calculate the sensor gain by comparing the surface %Sat(float) to the surface %Sat(WOA09) using > 1 year of data. We have developed Python scripts to provide QC'd data that are freely available and easily shared using IPython Notebooks hosted on GitHub. We will examine the consistency of the corrected oxygen data set, relative to existing climatologies, and its use in oceanographic studies.

  9. Exclusive Muon-Neutrino Charged Current Muon Plus Any Number of Protons Topologies In ArgoNeuT

    Energy Technology Data Exchange (ETDEWEB)

    Partyka, Kinga Anna [Yale Univ., New Haven, CT (United States)

    2013-01-01

    Neutrinos remain among the least understood fundamental particles even after decades of study. As we enter the precision era o f neutrino measurements bigger and more sophisticated detectors have emerged. The leading candidate among them is a Liquid Argon Time Projection Chamber (LArTPC ) detector technology due to its bubble-like chamber imaging, superb background rejection and scalability. I t is a perfect candidate that w ill aim to answer the remaining questions of the nature o f neutrino and perhaps our existence. Studying neutrinos with a detector that employs detection via beautiful images o f neutrino interactions can be both illuminating and surprising. The analysis presented here takes the full advantage of the LArTPC power by exploiting the first topological analysis of charged current muon neutrino p + N p , muon and any number of protons, interactions with the ArgoNeuT LArTPC experiment on an argon target. The results presented here are the first that address the proton multiplicity at the vertex and the proton kinematics. This study also addresses the importance o f nuclear effects in neutrino interactions. Furthermore, the developed here reconstruction techniques present a significant step forward for this technology and can be employed in the future LArTPC detectors.

  10. Exclusive Muon-Neutrino Charged Current muon plus any number of protons topologies in ArgoNeuT

    Science.gov (United States)

    Partyka, Kinga Anna

    Neutrinos remain among the least understood fundamental particles even after decades of study. As we enter the precision era of neutrino measurements bigger and more sophisticated detectors have emerged. The leading candidate among them is a Liquid Argon Time Projection Chamber (LArTPC) detector technology due to its bubble-like chamber imaging, superb background rejection and scalability. It is a perfect candidate that will aim to answer the remaining questions of the nature of neutrino and perhaps our existence. Studying neutrinos with a detector that employs detection via beautiful images of neutrino interactions can be bath illuminating and surprising. The analysis presented here takes the full advantage of the LArTPC power by exploiting the first topological analysis of charged current muon neutrino mu + Np, muon and any number of protons, interactions with the ArgoNeuT LArTPC experiment on an argon target. The results presented here are the first that address the proton multiplicity at the vertex and the proton kinematics. This study also addresses the importance of nuclear effects in neutrino interactions. Furthermore, the developed here reconstruction techniques present a significant step forward for this technology and can be employed in the future LArTPC detectors.

  11. Sonochemical Reactors.

    Science.gov (United States)

    Gogate, Parag R; Patil, Pankaj N

    2016-10-01

    Sonochemical reactors are based on the generation of cavitational events using ultrasound and offer immense potential for the intensification of physical and chemical processing applications. The present work presents a critical analysis of the underlying mechanisms for intensification, available reactor configurations and overview of the different applications exploited successfully, though mostly at laboratory scales. Guidelines have also been presented for optimum selection of the important operating parameters (frequency and intensity of irradiation, temperature and liquid physicochemical properties) as well as the geometric parameters (type of reactor configuration and the number/position of the transducers) so as to maximize the process intensification benefits. The key areas for future work so as to transform the successful technique at laboratory/pilot scale into commercial technology have also been discussed. Overall, it has been established that there is immense potential for sonochemical reactors for process intensification leading to greener processing and economic benefits. Combined efforts from a wide range of disciplines such as material science, physics, chemistry and chemical engineers are required to harness the benefits at commercial scale operation.

  12. Reactor container

    International Nuclear Information System (INIS)

    A reactor container has a suppression chamber partitioned by concrete side walls, a reactor pedestal and a diaphragm floor. A plurality of partitioning walls are disposed in circumferential direction each at an interval inside the suppression chamber, so that independent chambers in a state being divided into plurality are formed inside the suppression chamber. The partition walls are formed from the bottom portion of the suppression chamber up to the diaphragm floor to isolate pool water in a divided state. Operation platforms are formed above the suppression chamber and connected to an access port. Upon conducting maintenance, inspection or repairing, a pump is disposed in the independent chamber to transfer pool water therein to one or a plurality of other independent chambers to make it vacant. (I.N.)

  13. NEUTRONIC REACTORS

    Science.gov (United States)

    Anderson, J.B.

    1960-01-01

    A reactor is described which comprises a tank, a plurality of coaxial steel sleeves in the tank, a mass of water in the tank, and wire grids in abutting relationship within a plurality of elongated parallel channels within the steel sleeves, the wire being provided with a plurality of bends in the same plane forming adjacent parallel sections between bends, and the sections of adjacent grids being normally disposed relative to each other.

  14. The Knee of the Cosmic Hydrogen and Helium Spectrum below 1 PeV Measured by ARGO-YBJ and a Cherenkov Telescope of LHAASO

    CERN Document Server

    Bartoli, B; Bi, X J; Branchini, P; Budano, A; Camarri, P; Cao, Z; Cardarelli, R; Catalanotti, S; Chen, S Z; Chen, T L; Creti, P; Cui, S W; Dai, B Z; D'Amone, A; Danzengluobu,; De Mitri, I; Piazzoli, B D'Ettorre; Di Girolamo, T; Di Sciascio, G; Feng, C F; Feng, Zhaoyang; Feng, Zhenyong; Gou, Q B; Guo, Y Q; He, H H; Hu, Haibing; Hu, Hongbo; Iacovacci, M; Iuppa, R; Jia, H Y; Labaciren,; Li, H J; Liguori, G; Liu, C; Liu, J; Liu, M Y; Lu, H; Ma, L L; Ma, X H; Mancarella, G; Mari, S M; Marsella, G; Martello, D; Mastroianni, S; Montini, P; Ning, C C; Panareo, M; Perrone, L; Pistilli, P; Ruggieri, F; Salvini, P; Santonico, R; Shen, P R; Sheng, X D; Shi, F; Surdo, A; Tan, Y H; Vallania, P; Vernetto, S; Vigorito, C; Wang, H; Wu, C Y; Wu, H R; Xue, L; Yang, Q Y; Yang, X C; Yao, Z G; Yuan, A F; Zha, M; Zhang, H M; Zhang, L; Zhang, X Y; Zhang, Y; Zhao, J; Zhaxiciren,; Zhaxisangzhu,; Zhou, X X; Zhu, F R; Zhu, Q Q; Zizzi, G; Bai, Y X; Chen, M J; Chen, Y; Feng, S H; Gao, B; Gu, M H; Hou, C; Li, X X; Liu, J L; Wang, X; Xiao, G; Zhang, B K; Zhang, S S; Zhou, B; Zuo, X

    2015-01-01

    The measurement of cosmic ray energy spectra, in particular for individual species, is an essential approach in finding their origin. Locating the "knees" of the spectra is an important part of the approach and has yet to be achieved. Here we report a measurement of the mixed Hydrogen and Helium spectrum using the combination of the ARGO-YBJ experiment and of a prototype Cherenkov telescope for the LHAASO experiment. A knee feature at 640+/-87 TeV, with a clear steepening of the spectrum, is observed. This gives fundamental inputs to galactic cosmic ray acceleration models.

  15. Towards closure of regional heat budgets in the North Atlantic using Argo floats and surface flux datasets

    Directory of Open Access Journals (Sweden)

    N. C. Wells

    2009-04-01

    Full Text Available The upper ocean heat budget (0–300 m of the North Atlantic from 20°–60° N is investigated using data from Argo profiling floats for 1999–2005 and the NCEP/NCAR and NOC surface flux datasets. Estimates of the different terms in the budget (heat storage, advection, diffusion and surface exchange are obtained using the methodology developed by Hadfield et al. (2007a, b. The method includes optimal interpolation of the individual profiles to produce gridded fields with error estimates at a 10°×10° grid box resolution. Closure of the heat budget is obtained within the error estimates for some regions – particularly the eastern subtropical Atlantic – but not for those boxes that include the Gulf Stream. Over the whole range considered, closure is obtained for 13 (9 out of 20 boxes with the NOC (NCEP/NCAR surface fluxes. The seasonal heat budget at 20–30° N, 35–25° W is considered in detail. Here, the NCEP based budget has an annual mean residual of −55±35 Wm−2 compared with a NOC based value of −4±35 Wm−2. For this box, the net heat divergence of 36 Wm−2 (Ekman=−4 Wm−2, geostrophic=11 Wm−2, diffusion=29 Wm−2 offsets the net heating of 32 Wm−2 from the NOC surface heat fluxes. The results in this box are consistent with an earlier evaluation of the fluxes using measurements from research buoys in the subduction array which revealed biases in NCEP but good agreement of the buoy values with the NOC fields.

  16. Towards closure of regional heat budgets in the North Atlantic using Argo floats and surface flux datasets

    Directory of Open Access Journals (Sweden)

    N. C. Wells

    2009-01-01

    Full Text Available The upper ocean heat budget (0–300 m of the North Atlantic from 20°–60° N is investigated using data from Argo profiling floats for 1999–2005 and the NCEP/NCAR and NOC surface flux datasets. Estimates of the different terms in the budget (heat storage, advection, diffusion and surface exchange are obtained using the methodology developed by Hadfield et al. (2007. The method includes optimal interpolation of the individual profiles to produce gridded fields with error estimates at a 10×10 degree grid box resolution. Closure of the heat budget is obtained within the error estimates for some regions – particularly the eastern subtropical Atlantic – but not for those boxes that include the Gulf Stream. Over the whole range considered, closure is obtained for 13 (9 out of 20 boxes with the NOC (NCEP/NCAR surface fluxes. The seasonal heat budget at 20°–30° N, 35°–25° W is considered in detail. Here, the NCEP based budget has an annual mean residual of -55±35 W m-2 compared with a NOC based value of -4±35 W m-2. For this box, the net heat divergence of 36 W m-2 (Ekman=-4 W m-2, geostrophic=11 W m-2, diffusion=29 W m-2 offsets the net heating of 32 W m-2 from the NOC surface heat fluxes. The results in this box are consistent with an earlier evaluation of the fluxes using measurements from research buoys in the subduction array which revealed biases in NCEP but good agreement of the buoy values with the NOC fields.

  17. A high resolution salinity time series 1993-2012 in the North Atlantic from Argo and Altimeter data

    Science.gov (United States)

    Stendardo, I.; Rhein, M.; Hollmann, R.

    2016-04-01

    The study of salinity changes has been hampered by the lack of temporal and spatial resolution of the observations. In order to improve the spatial and temporal distribution of salinity observations, we used the Gravest Empirical Mode (GEM) technique to calculate high-resolution salinity distributions as a function of dynamic height for the period 1993-2012. This technique combined Argo and altimeter data to exploit the relationship between T/S profiles and dynamic height in the North Atlantic. The method was valid in the upper 700 m mainly at and near the pathways of the North Atlantic Current (NAC), but failed in regions with weak stratification or with ambiguities in the T/S relationships. Coherent, multiannual large-scale variability was observed, with many features present in all regions, albeit with weaker amplitudes in the eastern basins. Some of the interannual features in the northeastern Atlantic basins were unrelated to the variability further south and west, pointing to an occasional advection of subtropical water in the eastern Atlantic. Origin and advection of salinity anomalies with the NAC from the North American Basin into the western subpolar North Atlantic are correlated with the state of the North Atlantic Oscillation (NAO) and dampened by the surface freshwater fluxes. Other mechanisms influencing the salinity pattern are the changing location of the subpolar front, also related to the NAO. The large multiyear variability in the 20 year time series obscured any potential trends caused by global warming. Only the Rockall Trough showed a salinity increase of 0.03 per decade.

  18. Nuclear research reactors

    International Nuclear Information System (INIS)

    It's presented data about nuclear research reactors in the world, retrieved from the Sien (Nuclear and Energetic Information System) data bank. The information are organized in table forms as follows: research reactors by countries; research reactors by type; research reactors by fuel and research reactors by purpose. (E.G.)

  19. Nuclear reactor

    International Nuclear Information System (INIS)

    A nuclear reactor is described in which the core components, including fuel-rod assemblies, control-rod assemblies, fertile rod-assemblies, and removable shielding assemblies, are supported by a plurality of separate inlet modular units. These units are referred to as inlet module units to distinguish them from the modules of the upper internals of the reactor. The modular units are supported, each removable independently of the others, in liners in the supporting structure for the lower internals of the reactor. The core assemblies are removably supported in integral receptacles or sockets of the modular units. The liners, units, sockets and assemblies have inlet openings for entry of the fluid. The modular units are each removably mounted in the liners with fluid seals interposed between the opening in the liner and inlet module into which the fluid enters in the upper and lower portion of the liner. Each assembly is similarly mounted in a corresponding receptacle with fluid seals interposed between the openings where the fluid enters in the lower portion of the receptacle or fitting closely in these regions. As fluid flows along each core assembly a pressure drop is produced along the fluid so that the fluid which emerges from each core assembly is at a lower pressure than the fluid which enters the core assembly. However because of the seals interposed in the mountings of the units and assemblies the pressures above and below the units and assemblies are balanced and the units are held in the liners and the assemblies are held in the receptacles by their weights as they have a higher specific gravity than the fluid. The low-pressure spaces between each module and its liner and between each core assembly and its module is vented to the low-pressure regions of the vessel to assure that fluid which leaks through the seals does not accumulate and destroy the hydraulic balance

  20. Nuclear reactor physics course for reactor operators

    International Nuclear Information System (INIS)

    The education and training of nuclear reactor operators is important to guarantee the safe operation of present and future nuclear reactors. Therefore, a course on basic 'Nuclear reactor physics' in the initial and continuous training of reactor operators has proven to be indispensable. In most countries, such training also results from the direct request from the safety authorities to assure the high level of competence of the staff in nuclear reactors. The aim of the basic course on 'Nuclear Reactor Physics for reactor operators' is to provide the reactor operators with a basic understanding of the main concepts relevant to nuclear reactors. Seen the education level of the participants, mathematical derivations are simplified and reduced to a minimum, but not completely eliminated

  1. Decommissioning of an argonaut type reactor at the Technical University of Catalonia in Barcelona (Spain)

    International Nuclear Information System (INIS)

    The reactor ARGOS is a training nuclear reactor that was active, from 1962 to 1976, at the Technical University of Catalonia (UPC) in Barcelona (Spain). It is an Argonaut type experimental Reactor with 10 kW of maximal thermal power, and was set up by the main Spanish Nuclear Research Centre, presently named CIEMAT, in the period 1958-1962. In 1977, the nuclear installation was halted for technical, economical and administrative reasons. The fuel burn-up of the reactor was 2.7 kWh. In 1992 the fuel was removed from the site and a dismantling project was launched by an academic team of the UPC Nuclear Energy Department. In 1998 the Spanish authorities approved the dismantling plan which was based on the IAEA document Planning and Management of the Decommissioning of Research and Other Small Nuclear Facilities, IAEA 1993. In this plan the University proposed to set up its own dismantling group mainly based on its own academic staff and experimental facilities

  2. Sensitivity study of (10,100) GeV gamma-ray bursts with double shower front events from ARGO-YBJ

    Science.gov (United States)

    Zhou, Xun-Xiu; Gao, Lan-Lan; Zhang, Yu; Guo, Yi-Qing; Zhu, Qing-Qi; Jia, Huan-Yu; Huang, Dai-Hui

    2016-07-01

    ARGO-YBJ, located at the Yangbajing Cosmic Ray Observatory (4300 m a.s.l., Tibet, China), is a full coverage air shower array, with an energy threshold of ∼300 GeV for gamma-ray astronomy. Most of the recorded events are single front showers, satisfying the trigger requirement of at least 20 particles detected in a given time window. However, in ∼11.5% of the events, two randomly arriving showers may be recorded in the same time window, and the second one, generally smaller, does not need to satisfy the trigger condition. These events are called double shower front events. By using these small showers, well under the trigger threshold, the detector primary energy threshold can be lowered to a few tens of GeV. In this paper, the angular resolution that can be achieved with these events is evaluated by a full Monte Carlo simulation. The ARGO-YBJ sensitivity in detecting gamma-ray bursts (GRBs) by using double shower front events is also studied for various cutoff energies, time durations, and zenith angles of GRBs in ARGO’s field of view. Supported by National Natural Science Foundation of China (11475141) and Fundamental Research Funds for Central Universities (2682014CX091)

  3. Vertical temperature dynamics in the Northern Baltic Sea based on 3D modelling and data from shallow-water Argo floats

    Science.gov (United States)

    Westerlund, Antti; Tuomi, Laura

    2016-06-01

    3D hydrodynamic models often produce errors in the depth of the mixed layer and the vertical density structure. We used the 3D hydrodynamic model NEMO to investigate the effect of vertical turbulence parameterisations on seasonal temperature dynamics in the Bothnian Sea, Baltic Sea for the years 2012 and 2013. We used vertical profiles from new shallow-water Argo floats, operational in the area since 2012, to validate our model. We found that NEMO was able to reproduce the general features of the seasonal temperature variations in the study area, when meteorological forcing was accurate. The k-ε and k-ω schemes were selected for a more detailed analysis. Both schemes showed clear differences, but neither proved superior. While sea surface temperature was better simulated with the k-ω scheme, thermocline depth was clearly better with the k-ε scheme. We investigated the effect of wave-breaking on the mixing of the surface layer. The Craig and Banner parameterisation clearly improved the representation of thermocline depth. However, further tuning of the mixing parameterisations for the Baltic Sea is needed to better simulate the vertical temperature structure. We found the autonomous Baltic Sea Argo floats valuable for model validation and performance evaluation.

  4. Hydrodynamic variability of the Cretan Sea derived from Argo float profiles and multi-parametric buoy measurements during 2010-2012

    Science.gov (United States)

    Kassis, Dimitris; Korres, Gerasimos; Petihakis, George; Perivoliotis, Leonidas

    2015-12-01

    In this work, we examine the complex hydrology of the Cretan Sea, an important area which affects the dynamics of the Eastern Mediterranean basin. We use T/S profile data derived from the first Argo float deployed in the area during June 2010 within the framework of the Greek Argo program. Temperature and salinity profiles were measured over a 2-year period, analyzed, and combined with time series data recorded from the POSEIDON E1-M3A multi-parametric instrumentation platform operating in the area since 2007. The acquired datasets have been enriched with available CTD profiles taken on the mooring site during cruise maintenance surveys. The combined research activities resulted in a large dataset of physical properties allowing extended geographical coverage and an in-depth analysis of the Cretan Sea dynamics during this 2-year period. Data analysis shows significant variability of water masses of different origin at subsurface and deep layers. This confirms previous findings describing the area as transitional with water masses of different origin meeting and interacting. Furthermore, additional features of the area are described combining information from satellite altimetry. In this study, new circulation systems are identified at intermediate and subsurface layers affecting both the dynamic behavior of the basin's upper thermocline and the intermediate/deep water mass tempo-spatial variability. We further investigate the physical properties of the water column and suggest an updated mesoscale circulation picture based on the dynamics of the variable hydrological regimes of the Cretan Sea basin.

  5. 4.5 years multi-wavelength observations of Mrk 421 during the ARGO-YBJ and Fermi common operation time

    CERN Document Server

    Bartoli, B; Bi, X J; Cao, Z; Catalanotti, S; Chen, S Z; Chen, T L; Cui, S W; Dai, B Z; Damone, A; Danzengluobu,; De Mitri, I; Piazzoli, B D Ettorre; Di Girolamo, T; Di Sciascio, G; Feng, C F; Feng, Zhaoyang; Feng, Zhenyong; Gou, Q B; Guo, Y Q; He, H H; Hu, Haibing; Hu, Hongbo; Iacovacci, M; Iuppa, R; Jia, H Y; Labaciren,; Li, H J; Liu, C; Liu, J; Liu, M Y; Lu, H; Ma, L L; Ma, X H; Mancarella, G; Mari, S M; Marsella, G; Mastroianni, S; Montini, P; Ning, C C; Perrone, L; Pistilli, P; Salvini, P; Santonico, R; Shen, P R; Sheng, X D; Shi, F; Surdo, A; Tan, Y H; Vallania, P; Vernetto, S; Vigorito, C; Wang, H; Wu, C Y; Wu, H R; Xue, L; Yang, Q Y; Yang, X C; Yao, Z G; Yuan, A F; Zha, M; Zhang, H M; Zhang, L; Zhang, X Y; Zhang, Y; Zhao, J; Zhaxiciren,; Zhaxisangzhu,; Zhou, X X; Zhu, F R; Zhu, Q Q

    2016-01-01

    We report on the extensive multi-wavelength observations of the blazar Markarian 421 (Mrk 421) covering radio to gamma-rays, during the 4.5 year period of ARGO-YBJ and Fermi common operation time, from August 2008 to February 2013. In particular, thanks to the ARGO-YBJ and Fermi data, the whole energy range from 100 MeV to 10 TeV is covered without any gap. In the observation period, Mrk 421 showed both low and high activity states at all wavebands. The correlations among flux variations in different wavebands were analyzed. Seven large flares, including five X-ray flares and two GeV gamma-ray flares with variable durations (3-58 days), and one X-ray outburst phase were identified and used to investigate the variation of the spectral energy distribution with respect to a relative quiescent phase. During the outburst phase and the seven flaring episodes, the peak energy in X-rays is observed to increase from sub-keV to few keV. The TeV gamma-ray flux increases up to 0.9-7.2 times the flux of the Crab Nebula. T...

  6. Observation of TeV gamma-rays from the unidentified source HESS J1841-055 with the ARGO-YBJ experiment

    CERN Document Server

    Bartoli, B; Bi, X J; Bolognino, I; Branchini, P; Budano, A; Melcarne, A K Calabrese; Camarri, P; Cao, Z; Cardarelli, R; Catalanotti, S; Cattaneo, C; Chen, S Z; Chen, T L; Chen, Y; Creti, P; Cui, S W; Dai, B Z; Staiti, G DAli; DAmone, A; Danzengluobu,; De Mitri, I; Piazzoli, B DEttorre; Di Girolamo, T; Ding, X H; Di Sciascio, G; Feng, C F; Feng, Zhaoyang; Feng, Zhenyong; Galeazzi, F; Giroletti, E; Gou, Q B; Guo, Y Q; He, H H; Hu, Haibing; Hu, Hongbo; Huang, Q; Iacovacci, M; Iuppa, R; James, I; Jia, H Y; Labaciren,; Li, H J; Li, J Y; Li, X X; Liguori, G; Liu, C; Liu, C Q; Liu, J; Liu, M Y; Lu, H; Ma, L L; Ma, X H; Mancarella, G; Mari, S M; Marsella, G; Martello, D; Mastroianni, S; Montini, P; Ning, C C; Pagliaro, A; Panareo, M; Panico, B; Perrone, L; Pistilli, P; Ruggieri, F; Salvini, P; Santonico, R; Sbano, S N; Shen, P R; Sheng, X D; Shi, F; Surdo, A; Tan, Y H; Vallania, P; Vernetto, S; Vigorito, C; Wang, B; Wang, H; Wu, C Y; Wu, H R; Xu, B; Xue, L; Yang, Q Y; Yang, X C; Yao, Z G; Yuan, A F; Zha, M; Zhang, H M; Zhang, Jilong; Zhang, Jianli; Zhang, L; Zhang, P; Zhang, X Y; Zhang, Y; Zhao, J; Zhaxiciren,; Zhaxisangzhu,; Zhou, X X; Zhu, F R; Zhu, Q Q; Zizzi, G

    2013-01-01

    We report the observation of a very high energy \\gamma-ray source, whose position is coincident with HESS J1841-055. This source has been observed for 4.5 years by the ARGO-YBJ experiment from November 2007 to July 2012. Its emission is detected with a statistical significance of 5.3 standard deviations. Parameterizing the source shape with a two-dimensional Gaussian function we estimate an extension \\sigma=(0.40(+0.32,-0.22}) degree, consistent with the HESS measurement. The observed energy spectrum is dN/dE =(9.0-+1.6) x 10^{-13}(E/5 TeV)^{-2.32-+0.23} photons cm^{-2} s^{-1} TeV^{-1}, in the energy range 0.9-50 TeV. The integral \\gamma-ray flux above 1 TeV is 1.3-+0.4 Crab units, which is 3.2-+1.0 times the flux derived by HESS. The differences in the flux determination between HESS and ARGO-YBJ, and possible counterparts at other wavelengths are discussed.

  7. Detection of thermal neutrons with the PRISMA-YBJ array in extensive air showers selected by the ARGO-YBJ experiment

    Science.gov (United States)

    Bartoli, B.; Bernardini, P.; Bi, X. J.; Cao, Z.; Catalanotti, S.; Chen, S. Z.; Chen, T. L.; Cui, S. W.; Dai, B. Z.; D'Amone, A.; Danzengluobu; De Mitri, I.; D'Ettorre Piazzoli, B.; Di Girolamo, T.; Di Sciascio, G.; Feng, C. F.; Feng, Zhaoyang; Feng, Zhenyong; Gou, Q. B.; Guo, Y. Q.; He, H. H.; Hu, Haibing; Hu, Hongbo; Iacovacci, M.; Iuppa, R.; Jia, H. Y.; Labaciren; Li, H. J.; Liu, C.; Liu, J.; Liu, M. Y.; Lu, H.; Ma, L. L.; Ma, X. H.; Mancarella, G.; Mari, S. M.; Marsella, G.; Mastroianni, S.; Montini, P.; Ning, C. C.; Perrone, L.; Pistilli, P.; Salvini, P.; Santonico, R.; Shen, P. R.; Sheng, X. D.; Shi, F.; Surdo, A.; Tan, Y. H.; Vallania, P.; Vernetto, S.; Vigorito, C.; Wang, H.; Wu, C. Y.; Wu, H. R.; Xue, L.; Yang, Q. Y.; Yang, X. C.; Yao, Z. G.; Yuan, A. F.; Zha, M.; Zhang, H. M.; Zhang, L.; Zhang, X. Y.; Zhang, Y.; Zhao, J.; Zhaxiciren; Zhaxisangzhu; Zhou, X. X.; Zhu, F. R.; Zhu, Q. Q.; Stenkin, Yu. V.; Alekseenko, V. V.; Aynutdinov, V.; Cai, Z. Y.; Guo, X. W.; Liu, Y.; Rulev, V.; Shchegolev, O. B.; Stepanov, V.; Volchenko, V.; Zhang, H.

    2016-08-01

    We report on a measurement of thermal neutrons, generated by the hadronic component of extensive air showers (EAS), by means of a small array of EN-detectors developed for the PRISMA project (PRImary Spectrum Measurement Array), novel devices based on a compound alloy of ZnS(Ag) and 6LiF. This array has been operated within the ARGO-YBJ experiment at the high altitude Cosmic Ray Observatory in Yangbajing (Tibet, 4300 m a.s.l.). Due to the tight correlation between the air shower hadrons and thermal neutrons, this technique can be envisaged as a simple way to estimate the number of high energy hadrons in EAS. Coincident events generated by primary cosmic rays of energies greater than 100 TeV have been selected and analyzed. The EN-detectors have been used to record simultaneously thermal neutrons and the air shower electromagnetic component. The density distributions of both components and the total number of thermal neutrons have been measured. The correlation of these data with the measurements carried out by ARGO-YBJ confirms the excellent performance of the EN-detector.

  8. 4.5-year simultaneous multi-wavelength observation of Mrk 421 in the ARGO-YBJ and Fermi overlap era

    CERN Document Server

    Chen, Songzhan

    2015-01-01

    As one of the most active blazars, Mrk421 is an excellent candidate for the study of the physical processes within the jets of AGN. Here we report on the extensive multi-wavelength observations of Mrk 421 over 4.5 years, from 2008 August to 2013 February. This source was simultaneously monitored by several experiments at different wavelengths: ARGO-YBJ in TeV $\\gamma$-rays, $Fermi$-LAT in GeV $\\gamma$-rays, $Swift$-BAT in hard X-rays, $RXTE$-ASM, $MAXI$ and $Swift$-XRT in soft X-rays, $Swift$-UVOT in ultraviolet, and OVRO in radio frequencies. In particular, thanks to the ARGO-YBJ and $Fermi$ data, the whole energy range from 100 MeV to 10 TeV is covered without any gap. According to the observed light curves, ten states (including seven large flares, two quiescent phases and one outburst) were selected. For the first time, the multi-wavelength spectral evolutions of Mrk 421 during different states were systematically analyzed. During the outburst phase and the seven flaring episodes, the peak energy in X-ray...

  9. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  10. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  11. Reactor container

    International Nuclear Information System (INIS)

    Purpose: To prevent shocks exerted on a vent head due to pool-swell caused within a pressure suppression chamber (disposed in a torus configuration around the dry well) upon loss of coolant accident in BWR type reactors. Constitution: The following relationship is established between the volume V (m3) of a dry well and the ruptured opening area A (m2) at the boundary expected upon loss of coolant accident: V >= 30340 (m) x A Then, the volume of the dry well is made larger than the ruptured open area, that is, the steam flow rate of leaking coolants upon loss of coolant accident to decrease the pressure rise in the dry well at the initial state where loss of coolant accident is resulted. Accordingly, the pressure of non-compressive gases jetted out from the lower end of the downcomer to the pool water is decreased to suppress the pool-swell. (Ikeda, J.)

  12. Analysis of Vertical Dynamics in the Northern Baltic Sea based on 3D Modelling and Data from Shallow-Water Argo Floats

    Science.gov (United States)

    Westerlund, Antti; Tuomi, Laura

    2016-04-01

    Vertical mixing is a challenge for ocean models. 3D hydrodynamic models often produce considerable errors in mixed layer depths and vertical temperature structure that can be related to the vertical turbulence parameterisation. These errors can be pronounced in areas with complex hydrography. In the Baltic Sea, for example, there are high horizontal and vertical salinity gradients. Furthermore, thermocline and halocline are located at different depths. This produces stratification conditions challenging for all ocean models. We studied vertical mixing with modelling experiments and new observational data. NEMO 3D ocean model has been set up at Finnish Meteorological Institute (FMI) for the Baltic Sea, based on the NEMO Nordic configuration. The model has been discretized on a Baltic Sea - North Sea grid with 2 nautical mile resolution and 56 vertical layers, using FMI-HIRLAM atmospheric forcing. The observational data for Baltic Sea off-shore areas is sparse and new methods are needed to collect data for model validation and development. FMI has been testing Argo floats in the Baltic Sea since 2011 in order to increase the amount of observed vertical profiles of salinity and temperature. This is the first time Argo floats have been successfully used in the brackish, shallow waters of the Baltic Sea. This new data set is well suited for evaluating the capability of hydrodynamic models to produce the vertical structure of temperature. It provides a time series of profiles from the area of interest with good temporal resolution, showing the structure of temperature in the water column throughout the summer. We found that NEMO was able to reproduce the general features of the seasonal temperature variations in the study area, when meteorological forcing was accurate. We ran the model with different vertical turbulence parameterisations. The k-ɛ and k-ω schemes showed clear differences, but neither proved superior. While sea surface temperature was better simulated

  13. Research Nuclear Reactors

    International Nuclear Information System (INIS)

    Published in English and in French, this large report first proposes an overview of the use and history of research nuclear reactors. It discusses their definition, and presents the various types of research reactors which can be either related to nuclear power (critical mock-ups, material test reactors, safety test reactors, training reactors, prototypes), or to research (basic research, industry, health), or to specific particle physics phenomena (neutron diffraction, isotope production, neutron activation, neutron radiography, semiconductor doping). It reports the history of the French research reactors by distinguishing the first atomic pile (ZOE), and the activities and achievements during the fifties, the sixties and the seventies. It also addresses the development of instrumentation for research reactors (neutron, thermal, mechanical and fission gas release measurements). The other parts of the report concern the validation of neutronics calculations for different reactors (the EOLE water critical mock-up, the MASURCA air critical mock-up dedicated to fast neutron reactor study, the MINERVE water critical mock-up, the CALIBAN pulsed research reactor), the testing of materials under irradiation (OSIRIS reactor, laboratories associated with research reactors, the Jules Horowitz reactor and its experimental programs and related devices, irradiation of materials with ion beams), the investigation of accident situations (on the CABRI, Phebus, Silene and Jules Horowitz reactors). The last part proposes a worldwide overview of research reactors

  14. The Cosmic Ray p+He energy spectrum in the 3-3000 TeV energy range measured by ARGO-YBJ

    Science.gov (United States)

    Mari, S. M.; Montini, P.

    2016-07-01

    The ARGO-YBJ experiment is a full coverage air shower detector operated at the Yangbajing International Cosmic Ray Observatory. The detector has been in stable data taking in its full configuration since November 2007 to February 2013. The high altitude and the high segmentation and spacetime resolution offer the possibility to explore the cosmic ray energy spectrum in a very wide range, from a few TeV up to the PeV region. The high segmentation allows a detailed measurement of the lateral distribution, which can be used in order to discriminate showers produced by light and heavy elements. In this work we present the measurement of the cosmic ray light component spectrum in the energy range 3-3000 TeV. The analysis has been carried out by using a two-dimensional unfolding method based on the Bayes' theorem.

  15. Reactor Physics Training

    International Nuclear Information System (INIS)

    University courses in nuclear reactor physics at the universities consist of a theoretical description of the physics and technology of nuclear reactors. In order to demonstrate the basic concepts in reactor physics, training exercises in nuclear reactor installations are also desirable. Since the number of reactor facilities is however strongly decreasing in Europe, it becomes difficult to offer to students a means for demonstrating the basic concepts in reactor physics by performing training exercises in nuclear installations. Universities do not generally possess the capabilities for performing training exercises. Therefore, SCK-CEN offers universities the possibility to perform (on a commercial basis) training exercises at its infrastructure consisting of two research reactors (BR1 and VENUS). Besides the organisation of training exercises in the framework of university courses, SCK-CEN also organizes theoretical courses in reactor physics for the education and training of nuclear reactor operators. It is indeed a very important subject to guarantee the safe operation of present and future nuclear reactors. In this framework, an understanding of the fundamental principles of nuclear reactor physics is also necessary for reactor operators. Therefore, the organisation of a basic Nuclear reactor physics course at the level of reactor operators in the initial and continuous training of reactor operators has proven to be indispensable. In most countries, such training also results from the direct request from the safety authorities to assure the high level of competence of the staff in nuclear reactors. The objectives this activity are: (1) to provide training and education activities in reactor physics for university students and (2) to organise courses in nuclear reactor physics for reactor operators

  16. Safeguarding research reactors

    International Nuclear Information System (INIS)

    The report is organized in four sections, including the introduction. The second section contains a discussion of the characteristics and attributes of research reactors important to safeguards. In this section, research reactors are described according to their power level, if greater than 25 thermal megawatts, or according to each fuel type. This descriptive discussion includes both reactor and reactor fuel information of a generic nature, according to the following categories. 1. Research reactors with more than 25 megawatts thermal power, 2. Plate fuelled reactors, 3. Assembly fuelled reactors. 4. Research reactors fuelled with individual rods. 5. Disk fuelled reactors, and 6. Research reactors fuelled with aqueous homogeneous fuel. The third section consists of a brief discussion of general IAEA safeguards as they apply to research reactors. This section is based on IAEA safeguards implementation documents and technical reports that are used to establish Agency-State agreements and facility attachments. The fourth and last section describes inspection activities at research reactors necessary to meet Agency objectives. The scope of the activities extends to both pre and post inspection as well as the on-site inspection and includes the examination of records and reports relative to reactor operation and to receipts, shipments and certain internal transfers, periodic verification of fresh fuel, spent fuel and core fuel, activities related to containment and surveillance, and other selected activities, depending on the reactor

  17. Reactor Physics Programme

    Energy Technology Data Exchange (ETDEWEB)

    De Raedt, C

    2000-07-01

    The Reactor Physics and Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis on reactor fuel. This expertise is applied within the Reactor Physics and MYRRHA Research Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments. Progress and achievements in 1999 in the following areas are reported on: (1) investigations on the use of military plutonium in commercial power reactors; (2) neutron and gamma calculations performed for BR-2 and for other reactors; (3) the updating of neutron and gamma cross-section libraries; (4) the implementation of reactor codes; (6) the management of the UNIX workstations; and (6) fuel cycle studies.

  18. The bending of the proton plus helium flux in primary cosmic rays measured by the ARGO-YBJ experiment in the energy range from 20 TeV to 5 PeV

    CERN Document Server

    Montini, P

    2016-01-01

    The measurement of proton plus helium and all-particle energy spectra in the range $20\\,$ TeV to $5 \\,$PeV and $80 \\,$TeV to $5 \\,$PeV respectively are presented. Data taken by the ARGO-YBJ detector in the 2010 year have been analyzed. The ARGO-YBJ experiment (Tibet, P. R. China) has been taking data for more than five years by means of a full-coverage array of RPC detectors. The discrimination between showers produced by light and heavy primaries has been performed by looking at the lateral particle density close to the core region. A Bayesian unfolding technique was therefore applied to the measured quantities in order to evaluate the cosmic ray energy spectrum. The proton plus helium spectrum clearly shows a bending at about $1 \\,$PeV, while the all-particle spectrum is consistent with previous observations.

  19. Ship propulsion reactors technology

    International Nuclear Information System (INIS)

    This paper takes the state of the art on ship propulsion reactors technology. The french research programs with the corresponding technological stakes, the reactors specifications and advantages are detailed. (A.L.B.)

  20. Undergraduate reactor control experiment

    International Nuclear Information System (INIS)

    A sequence of reactor and related experiments has been a central element of a senior-level laboratory course at Pennsylvania State University (Penn State) for more than 20 yr. A new experiment has been developed where the students program and operate a computer controller that manipulates the speed of a secondary control rod to regulate TRIGA reactor power. Elementary feedback control theory is introduced to explain the experiment, which emphasizes the nonlinear aspect of reactor control where power level changes are equivalent to a change in control loop gain. Digital control of nuclear reactors has become more visible at Penn State with the replacement of the original analog-based TRIGA reactor control console with a modern computer-based digital control console. Several TRIGA reactor dynamics experiments, which comprise half of the three-credit laboratory course, lead to the control experiment finale: (a) digital simulation, (b) control rod calibration, (c) reactor pulsing, (d) reactivity oscillator, and (e) reactor noise

  1. Reactor System Design

    International Nuclear Information System (INIS)

    SMART NPP(Nuclear Power Plant) has been developed for duel purpose, electricity generation and energy supply for seawater desalination. The objective of this project IS to design the reactor system of SMART pilot plant(SMART-P) which will be built and operated for the integrated technology verification of SMART. SMART-P is an integral reactor in which primary components of reactor coolant system are enclosed in single pressure vessel without connecting pipes. The major components installed within a vessel includes a core, twelve steam generator cassettes, a low-temperature self pressurizer, twelve control rod drives, and two main coolant pumps. SMART-P reactor system design was categorized to the reactor coe design, fluid system design, reactor mechanical design, major component design and MMIS design. Reactor safety -analysis and performance analysis were performed for developed SMART=P reactor system. Also, the preparation of safety analysis report, and the technical support for licensing acquisition are performed

  2. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Hiroto

    1995-02-07

    A reactor container of the present invention has a structure that the reactor container is entirely at the same temperature as that at the inlet of the reactor and, a hot pool is incorporated therein, and the reactor container has is entirely at the same temperature and has substantially uniform temperature follow-up property transiently. Namely, if the temperature at the inlet of the reactor core changes, the temperature of the entire reactor container changes following this change, but no great temperature gradient is caused in the axial direction and no great heat stresses due to axial temperature distribution is caused. Occurrence of thermal stresses caused by the axial temperature distribution can be suppressed to improve the reliability of the reactor container. In addition, since the laying of the reactor inlet pipelines over the inside of the reactor is eliminated, the reactor container is made compact and the heat shielding structures above the reactor and a protection structure of container walls are simplified. Further, secondary coolants are filled to the outside of the reactor container to simplify the shieldings. The combined effects described above can improve economical property and reliability. (N.H.).

  3. Fossil nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Maurette, M.

    1976-01-01

    The discussion of fossil nuclear reactors (the Oklo phenomenon) covers the earth science background, neutron-induced isotopes and reactor operating conditions, radiation-damage studies, and reactor modeling. In conclusion possible future studies are suggested and the significance of the data obtained in past studies is summarized. (JSR)

  4. Nuclear reactor repairing device

    International Nuclear Information System (INIS)

    Purpose: To enable free repairing of an arbitrary position in an LMFBR reactor. Constitution: A laser light emitted from a laser oscillator installed out of a nuclear reactor is guided into a portion to be repaired in the reactor by using a reflecting mirror, thereby welding or cutting it. The guidance of the laser out of the reactor into the reactor is performed by an extension tube depending into a through hole of a rotary plug, and the guidance of the laser light into a portion to be repaired is performed by the transmitting and condensing action of the reflecting mirror. (Kamimura, M.)

  5. Nuclear reactor physics

    CERN Document Server

    Stacey, Weston M

    2010-01-01

    Nuclear reactor physics is the core discipline of nuclear engineering. Nuclear reactors now account for a significant portion of the electrical power generated worldwide, and new power reactors with improved fuel cycles are being developed. At the same time, the past few decades have seen an ever-increasing number of industrial, medical, military, and research applications for nuclear reactors. The second edition of this successful comprehensive textbook and reference on basic and advanced nuclear reactor physics has been completely updated, revised and enlarged to include the latest developme

  6. Light water reactor safety

    CERN Document Server

    Pershagen, B

    2013-01-01

    This book describes the principles and practices of reactor safety as applied to the design, regulation and operation of light water reactors, combining a historical approach with an up-to-date account of the safety, technology and operating experience of both pressurized water reactors and boiling water reactors. The introductory chapters set out the basic facts upon which the safety of light water reactors depend. The central section is devoted to the methods and results of safety analysis. The accidents at Three Mile Island and Chernobyl are reviewed and their implications for light wate

  7. Spinning fluids reactor

    Science.gov (United States)

    Miller, Jan D; Hupka, Jan; Aranowski, Robert

    2012-11-20

    A spinning fluids reactor, includes a reactor body (24) having a circular cross-section and a fluid contactor screen (26) within the reactor body (24). The fluid contactor screen (26) having a plurality of apertures and a circular cross-section concentric with the reactor body (24) for a length thus forming an inner volume (28) bound by the fluid contactor screen (26) and an outer volume (30) bound by the reactor body (24) and the fluid contactor screen (26). A primary inlet (20) can be operatively connected to the reactor body (24) and can be configured to produce flow-through first spinning flow of a first fluid within the inner volume (28). A secondary inlet (22) can similarly be operatively connected to the reactor body (24) and can be configured to produce a second flow of a second fluid within the outer volume (30) which is optionally spinning.

  8. Reactor Vessel Surveillance Program for Advanced Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Kyeong-Hoon; Kim, Tae-Wan; Lee, Gyu-Mahn; Kim, Jong-Wook; Park, Keun-Bae; Kim, Keung-Koo

    2008-10-15

    This report provides the design requirements of an integral type reactor vessel surveillance program for an integral type reactor in accordance with the requirements of Korean MEST (Ministry of Education, Science and Technology Development) Notice 2008-18. This report covers the requirements for the design of surveillance capsule assemblies including their test specimens, test block materials, handling tools, and monitors of the surveillance capsule neutron fluence and temperature. In addition, this report provides design requirements for the program for irradiation surveillance of reactor vessel materials, a layout of specimens and monitors in the surveillance capsule, procedures of installation and retrieval of the surveillance capsule assemblies, and the layout of the surveillance capsule assemblies in the reactor.

  9. Fast Spectrum Reactors

    CERN Document Server

    Todd, Donald; Tsvetkov, Pavel

    2012-01-01

    Fast Spectrum Reactors presents a detailed overview of world-wide technology contributing to the development of fast spectrum reactors. With a unique focus on the capabilities of fast spectrum reactors to address nuclear waste transmutation issues, in addition to the well-known capabilities of breeding new fuel, this volume describes how fast spectrum reactors contribute to the wide application of nuclear power systems to serve the global nuclear renaissance while minimizing nuclear proliferation concerns. Readers will find an introduction to the sustainable development of nuclear energy and the role of fast reactors, in addition to an economic analysis of nuclear reactors. A section devoted to neutronics offers the current trends in nuclear design, such as performance parameters and the optimization of advanced power systems. The latest findings on fuel management, partitioning and transmutation include the physics, efficiency and strategies of transmutation, homogeneous and heterogeneous recycling, in addit...

  10. Multipurpose research reactors

    International Nuclear Information System (INIS)

    The international symposium on the utilization of multipurpose research reactors and related international co-operation was organized by the IAEA to provide for information exchange on current uses of research reactors and international co-operative projects. The symposium was attended by about 140 participants from 36 countries and two international organizations. There were 49 oral presentations of papers and 24 poster presentations. The presentations were divided into 7 sessions devoted to the following topics: neutron beam research and applications of neutron scattering (6 papers and 1 poster), reactor engineering (6 papers and 5 posters), irradiation testing of fuel and material for fission and fusion reactors (6 papers and 10 posters), research reactor utilization programmes (13 papers and 4 posters), neutron capture therapy (4 papers), neutron activation analysis (3 papers and 4 posters), application of small reactors in research and training (11 papers). A separate abstract was prepared for each of these papers. Refs, figs and tabs

  11. Knee of the cosmic hydrogen and helium spectrum below 1 PeV measured by ARGO-YBJ and a Cherenkov telescope of LHAASO

    Science.gov (United States)

    Bartoli, B.; Bernardini, P.; Bi, X. J.; Cao, Z.; Catalanotti, S.; Chen, S. Z.; Chen, T. L.; Cui, S. W.; Dai, B. Z.; D'Amone, A.; Danzengluobu; De Mitri, I.; D'Ettorre Piazzoli, B.; Di Girolamo, T.; Di Sciascio, G.; Feng, C. F.; Feng, Zhaoyang; Feng, Zhenyong; Guo, Q. B.; Guo, Y. Q.; He, H. H.; Hu, Haibing; Hu, Hongbo; Iacovacci, M.; Iuppa, R.; Jia, H. Y.; Labaciren; Li, H. J.; Liu, C.; Liu, J.; Liu, M. Y.; Lu, H.; Ma, L. L.; Ma, X. H.; Mancarella, G.; Mari, S. M.; Marsella, G.; Mastroianni, S.; Montini, P.; Ning, C. C.; Perrone, L.; Pistilli, P.; Salvini, P.; Santonico, R.; Shen, P. R.; Sheng, X. D.; Shi, F.; Surdo, A.; Tan, Y. H.; Vallania, P.; Vernetto, S.; Vigorito, C.; Wang, H.; Wu, C. Y.; Wu, H. R.; Xue, L.; Yang, Q. Y.; Yang, X. C.; Yao, Z. G.; Yuan, A. F.; Zha, M.; Zhang, H. M.; Zhang, L.; Zhang, X. Y.; Zhang, Y.; Zhao, J.; Zhaxiciren; Zhaxisangzhu; Zhou, X. X.; Zhu, F. R.; Zhu, Q. Q.; Bai, Y. X.; Chen, M. J.; Feng, S. H.; Gao, B.; Gu, M. H.; Hou, C.; Liu, J.; Liu, J. L.; Wang, X.; Xiao, G.; Zhang, B. K.; Zhang, S. S.; Zhou, B.; Zuo, X.; ARGO-YBJ Collaboration‡

    2015-11-01

    The measurement of the cosmic ray energy spectrum, in particular for individual species of nuclei, is an important tool to investigate cosmic ray production and propagation mechanisms. The determination of the "knees" in the spectra of different species remains one of the main challenges in cosmic ray physics. In fact, experimental results are still conflicting. In this paper we report a measurement of the mixed proton and helium energy spectrum, obtained with the combined data of the ARGO-YBJ experiment and a wide field of view Cherenkov telescope, a prototype of the future LHAASO experiment. By means of a multiparameter technique, we have selected a high-purity proton plus helium sample. The reconstructed energy resolution is found to be about 25% throughout the investigated energy range from 100 TeV to 3 PeV, with a systematic uncertainty in the absolute energy scale of 9.7%. The found energy spectrum can be fitted with a broken power-law function, with a break at the energy Ek =700 ±230 (stat )±70 (sys ) TeV , where the spectral index changes from -2.56 ±0.05 to -3.24 ±0.36 . The statistical significance of the observed spectral break is 4.2 standard deviations.

  12. A gridded data set of upper-ocean hydrographic properties in the Weddell Gyre obtained by objective mapping of Argo float measurements

    Science.gov (United States)

    Reeve, K. A.; Boebel, O.; Kanzow, T.; Strass, V.; Rohardt, G.; Fahrbach, E.

    2016-02-01

    The Weddell Gyre plays a crucial role in the modification of climate by advecting heat poleward to the Antarctic ice shelves and by regulating the density of water masses that feed the lowest limb of the global ocean overturning circulation. However, our understanding of Weddell Gyre water mass properties is limited to regions of data availability, primarily along the Prime Meridian. The aim of this paper is to provide a data set of the upper water column properties of the entire Weddell Gyre. Objective mapping was applied to Argo float data in order to produce spatially gridded, time-composite maps of temperature and salinity for fixed pressure levels ranging from 50 to 2000 dbar, as well as temperature, salinity and pressure at the level of the sub-surface temperature maximum. While the data are currently too limited to incorporate time into the gridded structure, the data are extensive enough to produce maps of the entire region across three time-composite periods (2001-2005, 2006-2009 and 2010-2013), which can be used to determine how representative conclusions drawn from data collected along general RV transect lines are on a gyre scale perspective. The work presented here represents the technical prerequisite for addressing climatological research questions in forthcoming studies. The data sets are available in netCDF format at doi:10.1594/PANGAEA.842876.

  13. Detection of thermal neutrons with the PRISMA-YBJ array in Extensive Air Showers selected by the ARGO-YBJ experiment

    CERN Document Server

    Bartoli, B; Bi, X J; Cao, Z; Catalanotti, S; Chen, S Z; Chen, T L; Cui, S W; Dai, B Z; D'Amone, A; Danzengluobu,; De Mitri, I; Piazzoli, B D'Ettorre; Di Girolamo, T; Di Sciascio, G; Feng, C F; Feng, Zhaoyang; Feng, Zhenyong; Gou, Q B; Guo, Y Q; He, H H; Hu, Haibing; Hu, Hongbo; Iacovacci, M; Iuppa, R; Jia, H Y; Labaciren,; Li, H J; Liu, C; Liu, J; Liu, M Y; Lu, H; Ma, L L; Ma, X H; Mancarella, G; Mari, S M; Marsella, G; Mastroianni, S; Montini, P; Ning, C C; Perrone, L; Pistilli, P; Salvini, P; Santonico, R; Shen, P R; Sheng, X D; Shi, F; Surdo, A; Tan, Y H; Vallania, P; Vernetto, S; Vigorito, C; Wang, H; Wu, C Y; Wu, H R; Xue, L; Yang, Q Y; Yang, X C; Yao, Z G; Yuan, A F; Zha, M; Zhang, H M; Zhang, L; Zhang, X Y; Zhang, Y; Zhao, J; Zhaxiciren,; Zhaxisangzhu,; Zhou, X X; Zhu, F R; Zhu, Q Q; Stenkin, Yu V; Alekseenko, V V; Aynutdinov, V; Cai, Z Y; Guo, X W; Liu, Y; Rulev, V; Shchegolev, O B; Stepanov, V; Volchenko, V; Zhang, H

    2015-01-01

    We report on a measurement of thermal neutrons, generated by the hadronic component of extensive air showers (EAS), by means of a small array of EN-detectors developed for the PRISMA project (PRImary Spectrum Measurement Array), novel devices based on a compound alloy of ZnS(Ag) and 6LiF. This array has been operated within the ARGO-YBJ experiment at the high altitude Cosmic Ray Observatory in Yangbajing (Tibet, 4300 m a.s.l.). Due to the tight correlation between the air shower hadrons and thermal neutrons, this technique can be envisaged as a simple way to get information on the EAS hadronic component, avoiding the use of huge calorimeters. Coincident events generated by primary cosmic rays of energies greater than 100 TeV have been selected and analyzed. The EN-detectors have been used to record simultaneously thermal neutrons and the air shower electromagnetic component. The density distribution of both components and the total number of thermal neutrons have been measured. The correlation of these data w...

  14. Reactor BR2

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P

    2000-07-01

    The BR2 reactor is still SCK-CEN's most important nuclear facility. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. Various aspects concerning the operation of the BR2 Reactor, the utilisation of the CALLISTO loop and the irradiation programme, the BR2 R and D programme and the production of isotopes and of NTD-silicon are discussed. Progress and achievements in 1999 are reported.

  15. The Integral Fast Reactor

    International Nuclear Information System (INIS)

    The Integral Fast Reactor (IFR) is an innovative liquid metal reactor concept being developed at Argonne National Laboratory. It seeks to specifically exploit the inherent properties of liquid metal cooling and metallic fuel in a way that leads to substantial improvements in the characteristics of the complete reactor system. This paper describes the key features and potential advantages of the IFR concept, with emphasis on its safety characteristics. 3 refs., 4 figs., 1 tab

  16. Reactor Engineering Division annual report

    International Nuclear Information System (INIS)

    Research and development activities in the Division of Reactor Engineering in fiscal 1981 are described. The work of the Division is closely related to development of multipurpose Very High Temperature Gas Cooled Reactor and fusion reactor, and development of Liquid Metal Fast Breeder Reactor carried out by Power Reactor and Nuclear Fuel Development Corporation. Contents of the report are achievements in fields such as nuclear data and group constants, theoretical method and code development, integral experiment and analysis, shielding, reactor and nuclear instrumentation, reactor control and diagnosis, and fusion reactor technology, and activities of the Committee on Reactor Physics. (author)

  17. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kanbe, Mitsuru

    1997-04-04

    An LMFBR type reactor comprises a plurality of reactor cores in a reactor container. Namely, a plurality of pot containing vessels are disposed in the reactor vessel and a plurality of reactor cores are formed in a state where an integrated-type fuel assembly is each inserted to a pot, and a coolant pipeline is connected to each of the pot containing-vessel to cool the reactor core respectively. When fuels are exchanged, the integrated-type fuel assembly is taken out together with the pot from the reactor vessel in a state where the integrated-type fuel assembly is immersed in the coolants in the pot as it is. Accordingly, coolants are supplied to each of the pot containing-vessel connected with the coolant pipeline and circulate while cooling the integrated-type fuel assembly for every pot. Then, when the fuels are exchanged, the integrated type fuel assembly is taken out to the outside of the reactor together with the pot by taking up the pot from the pot-containing vessel. Then, neutron economy is improved to thereby improve reactor power and the breeding ratio. (N.H.)

  18. One piece reactor removal

    International Nuclear Information System (INIS)

    Japan Research Reactor No.3 (JRR-3) was the first reactor consisting of 'Japanese-made' components alone except for fuel and heavy water. After reaching its initial critical state in September 1962, JRR-3 had been in operation for 21 years until March 1983. It was decided that the reactor be removed en-bloc in view of the work schedule, cost and management of the reactor following the removal. In the special method developed jointly by the Japanese Atomic Energy Research Institute and Shimizu Construction Co., Ltd., the reactor main unit was cut off from the building by continuous core boring, with its major components bound in the block with biological shield material (heavy concrete), and then conveyed and stored in a large waste store building constructed near the reactor building. Major work processes described in this report include the cutting off, lifting, horizontal conveyance and lowering of the reactor main unit. The removal of the JRR-3 reactor main unit was successfully carried out safely and quickly by the en-block removal method with radiation exposure dose of the workers being kept at a minimum. Thus the high performance of the en-bloc removal method was demonstrated and, in addition, valuable knowhow and other data were obtained from the work. (Nogami, K.)

  19. Reactor Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Van Walle, E

    2001-04-01

    The activities of the Reactor Materials Research Department of the Belgian Nuclear Research Centre SCK-CEN in 2000 are summarised. The programmes within the department are focussed on studies concerning (1) fusion, in particular mechanical testing; (2) Irradiation Assisted Stress Corrosion Cracking (IASCC); (3) nuclear fuel; and (4) Reactor Pressure Vessel Steel (RPVS)

  20. Light water reactor program

    Energy Technology Data Exchange (ETDEWEB)

    Franks, S.M.

    1994-12-31

    The US Department of Energy`s Light Water Reactor Program is outlined. The scope of the program consists of: design certification of evolutionary plants; design, development, and design certification of simplified passive plants; first-of-a-kind engineering to achieve commercial standardization; plant lifetime improvement; and advanced reactor severe accident program. These program activities of the Office of Nuclear Energy are discussed.

  1. Research reactor DHRUVA

    International Nuclear Information System (INIS)

    DHRUVA, a 100 MWt research reactor located at the Bhabha Atomic Research Centre, Bombay, attained first criticality during August, 1985. The reactor is fuelled with natural uranium and is cooled, moderated and reflected by heavy water. Maximum thermal neutron flux obtained in the reactor is 1.8 X 1014 n/cm2/sec. Some of the salient design features of the reactor are discussed in this paper. Some important features of the reactor coolant system, regulation and protection systems and experimental facilities are presented. A short account of the engineered safety features is provided. Some of the problems that were faced during commissioning and the initial phase of power operation are also dealt upon

  2. TRIGA research reactors

    International Nuclear Information System (INIS)

    TRIGA (Training, Research, Isotope production, General-Atomic) has become the most used research reactor in the world with 65 units operating in 24 countries. The original patent for TRIGA reactors was registered in 1958. The success of this reactor is due to its inherent level of safety that results from a prompt negative temperature coefficient. Most of the neutron moderation occurs in the nuclear fuel (UZrH) because of the presence of hydrogen atoms, so in case of an increase of fuel temperature, the neutron spectrum becomes harder and neutrons are less likely to fission uranium nuclei and as a consequence the power released decreases. This inherent level of safety has made this reactor fit for training tool in university laboratories. Some recent versions of TRIGA reactors have been designed for medicine and industrial isotope production, for neutron therapy of cancers and for providing a neutron source. (A.C.)

  3. Mirror reactor surface study

    International Nuclear Information System (INIS)

    A general survey is presented of surface-related phenomena associated with the following mirror reactor elements: plasma first wall, ion sources, neutral beams, director converters, vacuum systems, and plasma diagnostics. A discussion of surface phenomena in possible abnormal reactor operation is included. Several studies which appear to merit immediate attention and which are essential to the development of mirror reactors are abstracted from the list of recommended areas for surface work. The appendix contains a discussion of the fundamentals of particle/surface interactions. The interactions surveyed are backscattering, thermal desorption, sputtering, diffusion, particle ranges in solids, and surface spectroscopic methods. A bibliography lists references in a number of categories pertinent to mirror reactors. Several complete published and unpublished reports on surface aspects of current mirror plasma experiments and reactor developments are also included

  4. Iris reactor conceptual design

    Energy Technology Data Exchange (ETDEWEB)

    Carelli, M.D.; Conway, L.E.; Petrovic, B.; Paramonov, D.V. [Westinghouse Electric Comp., Pittsburgh, PA (United States); Galvin, M.; Todreas, N.E. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Lombardi, C.V.; Maldari, F.; Ricotti, M.E. [Politecnico di Milano, Milan (Italy); Cinotti, L. [Ansaldo SpA, Genoa (Italy)

    2001-07-01

    IRIS (International Reactor Innovative and Secure) is a modular, integral, light water cooled, low-to-medium power (100-350 MWe) reactor which addresses the requirements defined by the US DOE for Generation IV reactors, i.e., proliferation resistance, enhanced safety, improved economics and fuel cycle sustainability. It relies on the proven technology of light water reactors and features innovative engineering, but it does not require new technology development. This paper discusses the current reference IRIS design, which features a 1000 MWt thermal core with proven 5%-enriched uranium oxide fuel and five-year long straight burn fuel cycle, integral reactor vessel housing helical tube steam generators and immersed spool pumps. Other major contributors to the high level of safety and economic attractiveness are the safety by design and optimized maintenance approaches, which allow elimination of some classes of accidents, lower capital cost, long operating cycle, and high capacity factors. (author)

  5. Status of French reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ballagny, A. [Commissariat a l`Energie Atomique, Saclay (France)

    1997-08-01

    The status of French reactors is reviewed. The ORPHEE and RHF reactors can not be operated with a LEU fuel which would be limited to 4.8 g U/cm{sup 3}. The OSIRIS reactor has already been converted to LEU. It will use U{sub 3}Si{sub 2} as soon as its present stock of UO{sub 2} fuel is used up, at the end of 1994. The decision to close down the SILOE reactor in the near future is not propitious for the start of a conversion process. The REX 2000 reactor, which is expected to be commissioned in 2005, will use LEU (except if the fast neutrons core option is selected). Concerning the end of the HEU fuel cycle, the best option is reprocessing followed by conversion of the reprocessed uranium to LEU.

  6. Compact torsatron reactors

    International Nuclear Information System (INIS)

    Low-aspect-ratio torsatron configurations could lead to compact stellarator reactors with R0 = 8--11m, roughly one-half to one-third the size of more conventional stellarator reactor designs. Minimum-size torsatron reactors are found using various assumptions. Their size is relatively insensitive to the choice of the conductor parameters and depends mostly on geometrical constraints. The smallest size is obtained by eliminating the tritium breeding blanket under the helical winding on the inboard side and by reducing the radial depth of the superconducting coil. Engineering design issues and reactor performance are examined for three examples to illustrate the feasibility of this approach for compact reactors and for a medium-size (R0 ≅ 4 m,/bar a/ /approx lt/ 1 m) copper-coil ignition experiment. 26 refs., 11 figs., 7 tabs

  7. Nuclear reactor design

    CERN Document Server

    2014-01-01

    This book focuses on core design and methods for design and analysis. It is based on advances made in nuclear power utilization and computational methods over the past 40 years, covering core design of boiling water reactors and pressurized water reactors, as well as fast reactors and high-temperature gas-cooled reactors. The objectives of this book are to help graduate and advanced undergraduate students to understand core design and analysis, and to serve as a background reference for engineers actively working in light water reactors. Methodologies for core design and analysis, together with physical descriptions, are emphasized. The book also covers coupled thermal hydraulic core calculations, plant dynamics, and safety analysis, allowing readers to understand core design in relation to plant control and safety.

  8. Reactor Engineering Division annual report

    International Nuclear Information System (INIS)

    Research activities in the Division of Reactor Engineering in fiscal 1977 are described. Works of the Division are development of multi-purpose Very High Temperature Gas Cooled Reactor, fusion reactor engineering, and development of Liquid Metal Fast Breeder Reactor for Power Reactor and Nuclear Fuel Development Corporation. Contents of the report are nuclear data and group constants, theoretical method and code development, integral experiment and analysis, shielding, heat transfer and fluid dynamics, reactor and nuclear instrumentation, dynamics analysis and control method development, fusion reactor technology, and Committee on Reactor Physics. (Author)

  9. Reactor Engineering Department annual report

    International Nuclear Information System (INIS)

    Research and development activities in the Department of Reactor Engineering in fiscal 1983 are described. The work of the Department is closely related to development of multipurpose Very High Temperature Gas Cooled Reactor and Fusion Reactor, and development of Liquid Metal Fast Breeder Reactor carried out by Power Reactor and Nuclear Fuel Development Corporation. Contents of the report are achievements in fields such as nuclear data and group constants, theoretical method and code development, integral experiment and analysis, fusion neutronics, shielding, reactor and nuclear instrumentation, reactor control and diagnosis, and safeguards technology, and activities of the Committee on Reactor Physics. (author)

  10. Reactor Engineering Division annual report

    International Nuclear Information System (INIS)

    Research activities conducted in Reactor Engineering Division in fiscal 1975 are summarized in this report. Works in the division are closely related to the development of multi-purpose High-temperature Gas Cooled Reactor, the development of Liquid Metal Fast Breeder Reactor by Power Reactor and Nuclear Fuel Development Corporation, and engineering research of thermonuclear fusion reactor. Many achievements are described concerning nuclear data and group constants, theoretical method and code development, integral experiment and analysis, shielding, heat transfer and fluid dynamics, reactor and nuclear instrumentation, dynamics analysis and control method development, fusion reactor technology and activities of the Committee on Reactor Physics. (auth.)

  11. Reactor performance calculations for water reactors

    International Nuclear Information System (INIS)

    The principles of nuclear, thermal and hydraulic performance calculations for water cooled reactors are discussed. The principles are illustrated by describing their implementation in the UKAEA PATRIARCH scheme of computer codes. This material was originally delivered as a course of lectures at the Technical University of Helsinki in Summer of 1969.

  12. Safety of research reactors

    International Nuclear Information System (INIS)

    The number of research reactors that have been constructed worldwide for civilian applications is about 651. Of the reactors constructed, 284 are currently in operation, 258 are shut down and 109 have been decommissioned. More than half of all operating research reactors worldwide are over thirty years old. During this long period of time national priorities have changed. Facility ageing, if not properly managed, has a natural degrading effect. Many research reactors face concerns with the obsolescence of equipment, lack of experimental programmes, lack of funding for operation and maintenance and loss of expertise through ageing and retirement of the staff. Other reactors of the same vintage maintain effective ageing management programmes, conduct active research programmes, develop and retain high calibre personnel and make important contributions to society. Many countries that operate research reactors neither operate nor plan to operate power reactors. In most of these countries there is a tendency not to create a formal regulatory body. A safety committee, not always independent of the operating organization, may be responsible for regulatory oversight. Even in countries with nuclear power plants, a regulatory regime differing from the one used for the power plants may exist. Concern is therefore focused on one tail of a continuous spectrum of operational performance. The IAEA has been sending missions to review the safety of research reactors in Member States since 1972. Some of the reviews have been conducted pursuant to the IAEA' functions and responsibilities regarding research reactors that are operated within the framework of Project and Supply Agreements between Member States and the IAEA. Other reviews have been conducted upon request. All these reviews are conducted following procedures for Integrated Safety Assessment of Research Reactors (INSARR) missions. The prime objective of these missions has been to conduct a comprehensive operational safety

  13. Reactor Engineering Department annual report

    International Nuclear Information System (INIS)

    This report summarizes the research and development activities in the Department of Reactor Engineering during the fiscal year of 1992 (April 1, 1992-March 31, 1993). The major Department's programs promoted in the year are the assessment of the high conversion light water reactor, the design activities of advanced reactor system and development of a high energy proton linear accelerator for the engineering applications including TRU incineration. Other major tasks of the Department are various basic researches on the nuclear data and group constants, the developments of theoretical methods and codes, the reactor physics experiments and their analyses, fusion neutronics, radiation shielding, reactor instrumentation, reactor control/diagnosis, thermohydraulics and technology developments related to the reactor physics facilities. The cooperative works to JAERI's major projects such as the high temperature gas cooled reactor or the fusion reactor and to PNC's fast reactor project were also progressed. The activities of the Research Committee on Reactor Physics are also summarized. (author)

  14. Reactor engineering department annual report

    International Nuclear Information System (INIS)

    This report summarizes the research and development activities in the Department of Reactor Engineering during the fiscal year of 1989 (April 1, 1989 - March 31, 1990). One of major Department's programs is the assessment of the high conversion light water reactor and the design activities of advanced reactor system. Development of a high energy proton linear accelerator for the nuclear engineering including is also TRU incineration promoted. Other major tasks of the Department are various basic researches on nuclear data and group constants, theoretical methods and code development, on reactor physics experiments and analyses, fusion neutronics, radiation shielding, reactor instrumentation, reactor control/diagnosis, thermohydraulics, technology assessment of nuclear energy and technology developments related to the reactor physics facilities. The cooperative works to JAERI's major projects such as the high temperature gas cooled reactor or the fusion reactor and to PNC's fast reactor project also progressed. The activities of the Research Committee on Reactor Physics are also summarized. (author)

  15. Comparison of 37 months global net radiation flux derived from PICARD-BOS over the same period observations of CERES and ARGO

    Science.gov (United States)

    Zhu, Ping; Wild, Martin

    2016-04-01

    The absolute level of the global net radiation flux (NRF) is fixed at the level of [0.5-1.0] Wm-2 based on the ocean heat content measurements [1]. The space derived global NRF is at the same order of magnitude than the ocean [2]. Considering the atmosphere has a negligible effects on the global NRF determination, the surface global NRF is consistent with the values determined from space [3]. Instead of studying the absolute level of the global NRF, we focus on the interannual variation of global net radiation flux, which were derived from the PICARD-BOS experiment and its comparison with values over the same period but obtained from the NASA-CERES system and inferred from the ocean heat content survey by ARGO network. [1] Allan, Richard P., Chunlei Liu, Norman G. Loeb, Matthew D. Palmer, Malcolm Roberts, Doug Smith, and Pier-Luigi Vidale (2014), Changes in global net radiative imbalance 1985-2012, Geophysical Research Letters, 41 (no.15), 5588-5597. [2] Loeb, Norman G., John M. Lyman, Gregory C. Johnson, Richard P. Allan, David R. Doelling, Takmeng Wong, Brian J. Soden, and Graeme L. Stephens (2012), Observed changes in top-of-the-atmosphere radiation and upper-ocean heating consistent within uncertainty, Nature Geoscience, 5 (no.2), 110-113. [3] Wild, Martin, Doris Folini, Maria Z. Hakuba, Christoph Schar, Sonia I. Seneviratne, Seiji Kato, David Rutan, Christof Ammann, Eric F. Wood, and Gert Konig-Langlo (2015), the energy balance over land and oceans: an assessment based on direct observations and CMIP5 climate models, Climate Dynamics, 44 (no.11-12), 3393-3429.

  16. Slurry reactor design studies

    Energy Technology Data Exchange (ETDEWEB)

    Fox, J.M.; Degen, B.D.; Cady, G.; Deslate, F.D.; Summers, R.L. (Bechtel Group, Inc., San Francisco, CA (USA)); Akgerman, A. (Texas A and M Univ., College Station, TX (USA)); Smith, J.M. (California Univ., Davis, CA (USA))

    1990-06-01

    The objective of these studies was to perform a realistic evaluation of the relative costs of tublar-fixed-bed and slurry reactors for methanol, mixed alcohols and Fischer-Tropsch syntheses under conditions where they would realistically be expected to operate. The slurry Fischer-Tropsch reactor was, therefore, operated at low H{sub 2}/CO ratio on gas directly from a Shell gasifier. The fixed-bed reactor was operated on 2.0 H{sub 2}/CO ratio gas after adjustment by shift and CO{sub 2} removal. Every attempt was made to give each reactor the benefit of its optimum design condition and correlations were developed to extend the models beyond the range of the experimental pilot plant data. For the methanol design, comparisons were made for a recycle plant with high methanol yield, this being the standard design condition. It is recognized that this is not necessarily the optimum application for the slurry reactor, which is being proposed for a once-through operation, coproducing methanol and power. Consideration is also given to the applicability of the slurry reactor to mixed alcohols, based on conditions provided by Lurgi for an Octamix{trademark} plant using their standard tubular-fixed reactor technology. 7 figs., 26 tabs.

  17. Test reactor technology

    International Nuclear Information System (INIS)

    The Reactor Development Program created a need for engineering testing of fuels and materials. The Engineering Test Reactors were developed around the world in response to this demand. The design of the test reactors proved to be different from that of power reactors, carrying the fuel elements closer to the threshold of failure, requiring more responsive instrumentation, more rapid control element action, and inherent self-limiting behavior under accident conditions. The design of the experimental facilities to exploit these reactors evolved a new, specialized, branch of engineering, requiring a very high-lvel scientific and engineering team, established a meticulous concern with reliability, the provision for recovery from their own failures, and detailed attention to possible interactions with the test reactors. This paper presents this technology commencing with the Materials Testing Reactor (MTR) through the Fast Flux Test Facility, some of the unique experimental facilities developed to exploit them, but discusses only cursorily the experiments performed, since sample preparation and sample analyses were, and to some extent still are, either classified or proprietary. The Nuclear Engineering literature is filled with this information

  18. Fast Breeder Reactor studies

    International Nuclear Information System (INIS)

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts

  19. Fast Breeder Reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts.

  20. Licensed operating reactors

    International Nuclear Information System (INIS)

    The Operating Units Status Report --- Licensed Operating Reactors provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management from the Headquarters staff on NRC's Office of Enforcement (OE), from NRC's Regional Offices, and from utilities. The three sections of the report are: monthly highlights and statistics for commercial operating units, and errata from previously reported data; a compilation of detailed information on each unit, provided by NRC's Regional Offices, OE Headquarters and the utilities; and an appendix for miscellaneous information such as spent fuel storage capability, reactor-years of experience and non- power reactors in the US

  1. nuclear reactor design calculations

    International Nuclear Information System (INIS)

    In this work , the sensitivity of different reactor calculation methods, and the effect of different assumptions and/or approximation are evaluated . A new concept named error map is developed to determine the relative importance of different factors affecting the accuracy of calculations. To achieve this goal a generalized, multigroup, multi dimension code UAR-DEPLETION is developed to calculate the spatial distribution of neutron flux, effective multiplication factor and the spatial composition of a reactor core for a period of time and for specified reactor operating conditions. The code also investigates the fuel management strategies and policies for the entire fuel cycle to meet the constraints of material and operating limitations

  2. Course on reactor physics

    International Nuclear Information System (INIS)

    In Germany only few students graduate in nuclear technology, therefore the NPP operating companies are forced to develop their own education and training concepts. AREVA NP has started together with the Technical University of Dresden a one-week course ''reactor physics'' that includes the know-how of the nuclear power plant construction company. The Technical University of Dresden has the training reactor AKR-2 that is retrofitted by modern digital instrumentation and control technology that allows the practical training of reactor control.

  3. PWR type reactor

    International Nuclear Information System (INIS)

    From a PWR with a primary circuit, consisting of a reactor pressure vessel, a steam generator and a reactor coolant pump, hot coolant is removed by means of an auxiliary system containing h.p. pumps for feeding water into the primary circuit and being connected with a pipe, originating at the upper part, which has got at least one isolating value. This is done by opening an outlet in a part of the auxiliary system that has got a lower pressure than the reactor vessel. Preferably a water jet pump is used for mixing with the water of the auxiliary system. (orig.)

  4. Microfluidic electrochemical reactors

    Science.gov (United States)

    Nuzzo, Ralph G.; Mitrovski, Svetlana M.

    2011-03-22

    A microfluidic electrochemical reactor includes an electrode and one or more microfluidic channels on the electrode, where the microfluidic channels are covered with a membrane containing a gas permeable polymer. The distance between the electrode and the membrane is less than 500 micrometers. The microfluidic electrochemical reactor can provide for increased reaction rates in electrochemical reactions using a gaseous reactant, as compared to conventional electrochemical cells. Microfluidic electrochemical reactors can be incorporated into devices for applications such as fuel cells, electrochemical analysis, microfluidic actuation, pH gradient formation.

  5. Reactor BR2. Introduction

    International Nuclear Information System (INIS)

    The BR2 is a materials testing reactor and is still one of SCK-CEN's important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. During the last three years, the availability of the installation was maintained at an average level of 97.6 percent. In the year 2000, the reactor was operated for a total of 104 days at a mean power of 56 MW. In 2000, most irradiation experiments were performed in the CALLISTO PWR loop. The report describes irradiations achieved or under preparation in 2000, including the development of advanced facilities and concept studies for new programmes. An overview of the scientific irradiation programmes as well as of the R and D programme of the BR2 reactor in 2000 is given

  6. NEUTRONIC REACTOR FUEL COMPOSITION

    Science.gov (United States)

    Thurber, W.C.

    1961-01-10

    Uranium-aluminum alloys in which boron is homogeneously dispersed by adding it as a nickel boride are described. These compositions have particular utility as fuels for neutronic reactors, boron being present as a burnable poison.

  7. Pulsed fusion reactors

    International Nuclear Information System (INIS)

    This summer school specialized in examining specific fusion center systems. Papers on scientific feasibility are first presented: confinement of high-beta plasma, liners, plasma focus, compression and heating and the use of high power electron beams for thermonuclear reactors. As for technological feasibility, lectures were on the theta-pinch toroidal reactors, toroidal diffuse pinch, electrical engineering problems in pulsed magnetically confined reactors, neutral gas layer for heat removal, the conceptual design of a series of laser fusion power plants with ''Saturn'', implosion experiments and the problem of the targets, the high brightness lasers for plasma generation, and topping and bottoming cycles. Some problems common to pulsed reactors were examined: energy storage and transfer, thermomechanical and erosion effects in the first wall and blanket, the problems of tritium production, radiation damage and neutron activation in blankets, and the magnetic and inertial confinement

  8. Reactor BR2. Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P

    2002-04-01

    The BR2 materials testing reactor is one of SCK-CEN's most important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. In 2001, the reactor was operated for a total of 123 days at a mean power of 59 MW in order to satisfy the irradiation conditions of the internal and external programmes using mainly the CALLISTO PWR loop. The mean consumption of fresh fuel elements was 5.26 per 1000 MWd. Main achievements in 2001 included the development of a three-dimensional full-scale model of the BR2 reactor for simulation and prediction of irradiation conditions for various experiments; the construction of the FUTURE-MT device designed for the irradiation of fuel plates under representative conditions of geometry, neutron spectrum, heat flux and thermal-hydraulic conditions and the development of in-pile instrumentation and a data acquisition system.

  9. Reactor BR2. Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P

    2001-04-01

    The BR2 is a materials testing reactor and is still one of SCK-CEN's important nuclear facilities. After an extensive refurbishment to compensate for the ageing of the installation, the reactor was restarted in April 1997. During the last three years, the availability of the installation was maintained at an average level of 97.6 percent. In the year 2000, the reactor was operated for a total of 104 days at a mean power of 56 MW. In 2000, most irradiation experiments were performed in the CALLISTO PWR loop. The report describes irradiations achieved or under preparation in 2000, including the development of advanced facilities and concept studies for new programmes. An overview of the scientific irradiation programmes as well as of the R and D programme of the BR2 reactor in 2000 is given.

  10. Reactor Neutrino Spectra

    CERN Document Server

    Hayes, A C

    2016-01-01

    We present a review of the antineutrino spectra emitted from reactors. Knowledge of these and their associated uncertainties are crucial for neutrino oscillation studies. The spectra used to-date have been determined by either conversion of measured electron spectra to antineutrino spectra or by summing over all of the thousands of transitions that makeup the spectra using modern databases as input. The uncertainties in the subdominant corrections to beta-decay plague both methods, and we provide estimates of these uncertainties. Improving on current knowledge of the antineutrino spectra from reactors will require new experiments. Such experiments would also address the so-called reactor neutrino anomaly and the possible origin of the shoulder observed in the antineutrino spectra measured in recent high-statistics reactor neutrino experiments.

  11. Experience with Kamini reactor

    International Nuclear Information System (INIS)

    Kamini is a 233U fuelled, 30 kW(th) research reactor. It is one of the best neutron source facility with a core average flux of 1012 n/cm2/s in IGCAR used for neutron radiography of active and nonradioactive objects, activation analysis and radiation physics research. The core consists of nine plate type fuel elements with a total fuel inventory of 590 g of 233U. Two safety control plates made of cadmium are used for start up and shutdown of the reactor. Three beam tubes, two-thimble irradiation site outside reflector and one irradiation site nearer to the core constitute the testing facilities of Kamini. Kamini attained first criticality on 29th October 96 and nominal power of 30 kW in September 1997. This paper covers the design features of the reactor, irradiation facilities and their utilities and operating experience of the reactor. (author)

  12. Reactor pressure boundary materials

    International Nuclear Information System (INIS)

    With a long-term operation of nuclear power plants, the component materials are degraded under severe reactor conditions such as neutron irradiation, high temperature, high pressure and corrosive environment. It is necessary to establish the reliable and practical technologies for improving and developing the component materials and for evaluating the mechanical properties. Especially, it is very important to investigate the technologies for reactor pressure boundary materials such as reactor vessel and pipings in accordance with their critical roles. Therefore, this study was focused on developing and advancing the microstructural/micro-mechanical evaluation technologies, and on evaluating the neutron irradiation characteristics and radiation effects analysis technology of the reactor pressure boundary materials, and also on establishing a basis of nuclear material property database

  13. Fusion Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2002-04-01

    The objective of SCK-CEN's programme on fusion reactor materials is to contribute to the knowledge on the radiation-induced behaviour of fusion reactor materials and components as well as to help the international community in building the scientific and technical basis needed for the construction of the future reactor. Ongoing projects include: the study of the mechanical and chemical (corrosion) behaviour of structural materials under neutron irradiation and water coolant environment; the investigation of the characteristics of irradiated first wall material such as beryllium; investigations on the management of materials resulting from the dismantling of fusion reactors including waste disposal. Progress and achievements in these areas in 2001 are discussed.

  14. New reactor type proposed

    CERN Multimedia

    2003-01-01

    "Russian scientists at the Research Institute of Nuclear Power Engineering in Moscow are hoping to develop a new reactor that will use lead and bismuth as fuel instead of uranium and plutonium" (1/2 page).

  15. Special lecture on nuclear reactor

    International Nuclear Information System (INIS)

    This book gives a special lecture on nuclear reactor, which is divided into two parts. The first part has explanation on nuclear design of nuclear reactor and analysis of core with theories of integral transports, diffusion Nodal, transports Nodal and Monte Carlo skill parallel computer and nuclear calculation and speciality of transmutation reactor. The second part deals with speciality of nuclear reactor and control with nonlinear stabilization of nuclear reactor, nonlinear control of nuclear reactor, neural network and control of nuclear reactor, control theory of observer and analysis method of Adomian.

  16. Jet-Stirred Reactors

    OpenAIRE

    Herbinet, Olivier; Guillaume, Dayma

    2013-01-01

    The jet-stirred reactor is a type of ideal continuously stirred-tank reactor which is well suited for gas phase kinetic studies. It is mainly used to study the oxidation and the pyrolysis of hydrocarbon and oxygenated fuels. These studies consist in recording the evolution of the conversion of the reactants and of the mole fractions of reaction products as a function of different parameters such as reaction temperature, residence time, pressure and composition of the inlet gas. Gas chromatogr...

  17. Generation IV reactors: economics

    International Nuclear Information System (INIS)

    The operating nuclear reactors were built over a short period: no more than 10 years and today their average age rounds 18 years. EDF (French electricity company) plans to renew its reactor park over a far longer period : 30 years from 2020 to 2050. According to EDF this objective implies 3 constraints: 1) a service life of 50 to 60 years for a significant part of the present operating reactors, 2) to be ready to built a generation 3+ unit in 2020 which infers the third constraint: 3) to launch the construction of an EPR (European pressurized reactor) prototype as soon as possible in order to have it operating in 2010. In this scheme, generation 4 reactor will benefit the feedback experience of generation 3 and will take over in 2030. Economic analysis is an important tool that has been used by the generation 4 international forum to select the likely future reactor systems. This analysis is based on 4 independent criteria: the basic construction cost, the construction time, the operation and maintenance costs and the fuel cycle cost. This analysis leads to the evaluation of the global cost of electricity generation and of the total investment required for each of the reactor system. The former defines the economic competitiveness in a de-regulated energy market while the latter is linked to the financial risk taken by the investor. It appears, within the limits of the assumptions and models used, that generation 4 reactors will be characterized by a better competitiveness and an equivalent financial risk when compared with the previous generation. (A.C.)

  18. OECD Halden reactor project

    International Nuclear Information System (INIS)

    This report summarizes the activities of the OECD Halden Reactor Project for the year 1976. The main items reported on are: a) the process supervision and control which have focused on core monitoring and control, and operator-process communication; b) the fuel performance and safety behavior which have provided data and analytical descriptions of the thermal, mechanical and chemical behavior of fuel under various operating conditions; c) the reactor operations and d) the administration and finance

  19. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    A nuclear reactor fuel element comprising a column of vibration compacted fuel which is retained in consolidated condition by a thimble shaped plug. The plug is wedged into gripping engagement with the wall of the sheath by a wedge. The wedge material has a lower coefficient of expansion than the sheath material so that at reactor operating temperature the retainer can relax sufficient to accommodate thermal expansion of the column of fuel. (author)

  20. Department of Reactor Technology

    DEFF Research Database (Denmark)

    Risø National Laboratory, Roskilde

    The general development of the Department of Reactor Technology at Risø during 1981 is presented, and the activities within the major subject fields are described in some detail. Lists of staff, publications, and computer programs are included.......The general development of the Department of Reactor Technology at Risø during 1981 is presented, and the activities within the major subject fields are described in some detail. Lists of staff, publications, and computer programs are included....

  1. Moon base reactor system

    Science.gov (United States)

    Chavez, H.; Flores, J.; Nguyen, M.; Carsen, K.

    1989-01-01

    The objective of our reactor design is to supply a lunar-based research facility with 20 MW(e). The fundamental layout of this lunar-based system includes the reactor, power conversion devices, and a radiator. The additional aim of this reactor is a longevity of 12 to 15 years. The reactor is a liquid metal fast breeder that has a breeding ratio very close to 1.0. The geometry of the core is cylindrical. The metallic fuel rods are of beryllium oxide enriched with varying degrees of uranium, with a beryllium core reflector. The liquid metal coolant chosen was natural lithium. After the liquid metal coolant leaves the reactor, it goes directly into the power conversion devices. The power conversion devices are Stirling engines. The heated coolant acts as a hot reservoir to the device. It then enters the radiator to be cooled and reenters the Stirling engine acting as a cold reservoir. The engines' operating fluid is helium, a highly conductive gas. These Stirling engines are hermetically sealed. Although natural lithium produces a lower breeding ratio, it does have a larger temperature range than sodium. It is also corrosive to steel. This is why the container material must be carefully chosen. One option is to use an expensive alloy of cerbium and zirconium. The radiator must be made of a highly conductive material whose melting point temperature is not exceeded in the reactor and whose structural strength can withstand meteor showers.

  2. BWR type nuclear reactor

    International Nuclear Information System (INIS)

    Purpose: To simplify the structure of an emergency core cooling system while suppressing the flow out of coolants upon rapture accidents in a coolant recycling device of BWR type reactors. Constitution: Recirculation pumps are located at a position higher than the reactor core in a pressure vessel, and the lower plenum is bisected vertically by a partition plate. Further, a gas-liquid separator is surrounded with a wall and the water level at the outer side of the wall is made higher than the water level in the inside of the wall. In this structure, coolants are introduced from the upper chamber in the lower plenum into the reactor core, and the steams generated in the reactor core are separated in the gas-liquid separator, whereby the separated liquid is introduced as coolants by way of the inner chamber into the lower chamber of the lower plenum and further sent by way of the outer chamber into the reactor core. Consequently, idle rotation of the recycling pumps due to the flow-in of saturated water is prevented and loss of coolants in the reactor core can also be prevented upon raptures in the pipeway and the driving section of the pump connected to the pressure vessel and in the bottom of the pressure vessel. (Horiuchi, T.)

  3. OECD Halden reactor project

    International Nuclear Information System (INIS)

    This is the nineteenth annual Report on the OECD Halden Reactor Project, describing activities at the Project during 1978, the last year of the 1976-1978 Halden Agreement. Work continued in two main fields: test fuel irradiation and fuel research, and computer-based process supervision and control. Project research on water reactor fuel focusses on various aspects of fuel behavior under normal, and off-normal transient conditions. In 1978, participating organisations continued to submit test fuel for irradiation in the Halden boiling heavy-water reactor, in instrumented test assemblies designed and manufactured by the Project. Work included analysis of the impact of fuel design and reactor operating conditions on fuel cladding behavior. Fuel performance modelling included characterization of thermal and mechanical behavior at high burn-up, of fuel failure modes, and improvement of data qualification procedures to reduce and quantify error bands on in-reactor measurements. Instrument development yielded new or improved designs for measuring rod temperature, internal pressure, axial neutron flux shape determination, and for detecting cladding defects. Work on computer-based methods of reactor supervision and control included continued development of a system for predictive core surveillance, and of special mathematical methods for core power distribution control

  4. Reactor physics and economic aspects of the CANDU reactor system

    International Nuclear Information System (INIS)

    A history of the development of the CANDU system is given along with a fairly detailed description of the 600 MW(e) CANDU reactor. Reactor physics calculation methods are described, as well as comparisons between calculated reactor physics parameters and those measured in research and power reactors. An examination of the economics of CANDU in the Ontario Hydro system and a comparison between fossil fuelled and light water reactors is presented. Some physics, economics and resources aspects are given for both low enriched uranium and thorium-fuelled CANDU reactors. Finally the RβD program in Advanced Fuel Cycles is briefly described

  5. Reactor Safety Planning for Prometheus Project, for Naval Reactors Information

    Energy Technology Data Exchange (ETDEWEB)

    P. Delmolino

    2005-05-06

    The purpose of this letter is to submit to Naval Reactors the initial plan for the Prometheus project Reactor Safety work. The Prometheus project is currently developing plans for cold physics experiments and reactor prototype tests. These tests and facilities may require safety analysis and siting support. In addition to the ground facilities, the flight reactor units will require unique analyses to evaluate the risk to the public from normal operations and credible accident conditions. This letter outlines major safety documents that will be submitted with estimated deliverable dates. Included in this planning is the reactor servicing documentation and shipping analysis that will be submitted to Naval Reactors.

  6. Fast breeder reactor research

    International Nuclear Information System (INIS)

    Full text: The meeting was attended by 15 participants from seven countries and two international organizations. The Eighth Annual Meeting of the International Working Group on Fast Reactors (IWGFR) was attended by representatives from France, Fed. Rep. Germany, Italy, Japan, United Kingdom, Union of Soviet Socialist Republics and the United States of America - countries that have made significant progress in developing the technology and physics of sodium cooled fast reactors and have extensive national programmes in this field - as well as by representatives of the Commission of the European Communities and the IAEA. The design of fast-reactor power plants is a more difficult task than developing facilities with thermal reactors. Different reactor kinetics and dynamics, a hard neutron spectrum, larger integral doses of fuel and structural material irradiation, higher core temperatures, the use of an essentially novel coolant, and, as a result of all these factors, the additional reliability and safety requirements that are imposed on the planning and operation of sodium cooled fast reactors - all these factors pose problems that can be solved comprehensively only by countries with a high level of scientific and technical development. The exchange of experience between these countries and their combined efforts in solving the fundamental problems that arise in planning, constructing and operating fast reactors are promoting technical progress and reducing the relative expenditure required for various studies on developing and introducing commercial fast reactors. For this reason, the meeting concentrated on reviewing and discussing national fast reactor programmes. The situation with regard to planning, constructing and operating fast experimental and demonstration reactors in the countries concerned, the experience accumulated in operating them, the difficulties arising during operation and ways of over-coming them, the search for optimal designs for the power

  7. Improvement of radiological consequence estimation methodologies for NPP accidents in the ARGOS and RODOS decision support systems through consideration of contaminant physico-chemical forms

    International Nuclear Information System (INIS)

    The European standard computerized decision support systems RODOS and ARGOS, which are integrated in the operational nuclear emergency preparedness in practically all European countries, as well as in a range of non-European countries, are highly valuable tools for radiological consequence estimation, e.g., in connection with planning and exercising as well as in justification and optimization of intervention strategies. Differences between the Chernobyl and Fukushima accident atmospheric release source terms have demonstrated that differences in release conditions and processes may lead to very different degrees of volatilization of some radionuclides. Also the physico-chemical properties of radionuclides released can depend strongly on the release process. An example from the Chernobyl accident of the significance of this is that strontium particles released in the fire were oxidized and thus generally physico-chemically different from those released during the preceding explosion. This is reflected in the very different environmental mobility of the two groups of particles. The initial elemental matrix characteristics of the contaminants, as well as environmental parameters like pH, determine for instance the particle dissolution time functions, and thus the environmental mobility and potential for uptake in living organisms. As ICRP recommends optimization of intervention according to residual dose, it is crucial to estimate long term dose contributions adequately. In the EURATOM FP7 project PREPARE, an effort is made to integrate physico-chemical forms of contaminants in scenario-specific source term determination, thereby enabling consideration of influences on atmospheric dispersion/deposition, post-deposition migration, and effectiveness of countermeasure implementation. The first step in this context was to investigate, based on available experience, the important physico-chemical properties of radio-contaminants that might potentially be released to the

  8. BR2 Reactor: Introduction

    International Nuclear Information System (INIS)

    The irradiations in the BR2 reactor are in collaboration with or at the request of third parties such as the European Commission, the IAEA, research centres and utilities, reactor vendors or fuel manufacturers. The reactor also contributes significantly to the production of radioisotopes for medical and industrial applications, to neutron silicon doping for the semiconductor industry and to scientific irradiations for universities. Along the ongoing programmes on fuel and materials development, several new irradiation devices are in use or in design. Amongst others a loop providing enhanced cooling for novel materials testing reactor fuel, a device for high temperature gas cooled fuel as well as a rig for the irradiation of metallurgical samples in a Pb-Bi environment. A full scale 3-D heterogeneous model of BR2 is available. The model describes the real hyperbolic arrangement of the reactor and includes the detailed 3-D space dependent distribution of the isotopic fuel depletion in the fuel elements. The model is validated on the reactivity measurements of several tens of BR2 operation cycles. The accurate calculations of the axial and radial distributions of the poisoning of the beryllium matrix by 3He, 6Li and 3T are verified on the measured reactivity losses used to predict the reactivity behavior for the coming decades. The model calculates the main functionals in reactor physics like: conventional thermal and equivalent fission neutron fluxes, number of displacements per atom, fission rate, thermal power characteristics as heat flux and linear power density, neutron/gamma heating, determination of the fission energy deposited in fuel plates/rods, neutron multiplication factor and fuel burn-up. For each reactor irradiation project, a detailed geometry model of the experimental device and of its neighborhood is developed. Neutron fluxes are predicted within approximately 10 percent in comparison with the dosimetry measurements. Fission rate, heat flux and

  9. Scaleable, High Efficiency Microchannel Sabatier Reactor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A Microchannel Sabatier Reactor System (MSRS) consisting of cross connected arrays of isothermal or graded temperature reactors is proposed. The reactor array...

  10. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Takeshi; Iida, Masaaki; Moriki, Yasuyuki

    1994-10-18

    A reactor core is divided into a plurality of coolants flowrate regions, and electromagnetic pumps exclusively used for each of the flowrate regions are disposed to distribute coolants flowrates in the reactor core. Further, the flowrate of each of the electromagnetic pumps is automatically controlled depending on signals from a temperature detector disposed at the exit of the reactor core, so that the flowrate of the region can be controlled optimally depending on the burning of reactor core fuels. Then, the electromagnetic pumps disposed for every divided region are controlled respectively, so that the coolants flowrate distribution suitable to each of the regions can be attained. Margin for fuel design is decreased, fuels are used effectively, as well as an operation efficiency can be improved. Moreover, since the electromagnetic pump has less flow resistance compared with a mechanical type pump, and flow resistance of the reactor core flowrate control mechanism is eliminated, greater circulating flowrate can be ensured after occurrence of accident in a natural convection using a buoyancy of coolants utilizable for after-heat removal as a driving force. (N.H.).

  11. Reactor coolant cleanup facility

    International Nuclear Information System (INIS)

    A depressurization device is disposed in pipelines upstream of recycling pumps of a reactor coolant cleanup facility to reduce a pressure between the pressurization device and the recycling pump at the downstream, thereby enabling high pressure coolant injection from other systems by way of the recycling pumps. Upon emergency, the recycling pumps of the coolant cleanup facility can be used in common to an emergency reactor core cooling facility and a reactor shutdown facility. Since existent pumps of the emergency reactor core cooling facility and the reactor shutdown facility which are usually in a stand-by state can be removed, operation confirmation test and maintenance for equipments in both of facilities can be saved, so that maintenance and reliability of the plant are improved and burdens on operators can also be mitigated. Moreover, low pressure design can be adopted for a non-regenerative heat exchanger and recycling coolant pumps, which enables to improve the reliability and economical property due to reduction of possibility of leakage. (N.H.)

  12. EBT reactor analysis

    International Nuclear Information System (INIS)

    This report summarizes the results of a recent ELMO Bumpy Torus (EBT) reactor study that includes ring and core plasma properties with consistent treatment of coupled ring-core stability criteria and power balance requirements. The principal finding is that constraints imposed by these coupling and other physics and technology considerations permit a broad operating window for reactor design optimization. Within this operating window, physics and engineering systems analysis and cost sensitivity studies indicate that reactors with approx. 6 to 10%, P approx. 1200 to 1700 MW(e), wall loading approx. 1.0 to 2.5 MW/m2, and recirculating power fraction (including ring-sustaining power and all other reactors auxiliaries) approx. 10 to 15% are possible. A number of concept improvements are also proposed that are found to offer the potential for further improvement of the reactor size and parameters. These include, but are not limited to, the use of: (1) supplementary coils or noncircular mirror coils to improve magnetic geometry and reduce size, (2) energetic ion rings to improve ring power requirements, (3) positive potential to enhance confinement and reduce size, and (4) profile control to improve stability and overall fusion power density

  13. Generalities about nuclear reactors

    International Nuclear Information System (INIS)

    From Zoe, the first nuclear reactor, till the current EPR, the French nuclear industry has always advanced by profiting from the feedback from dozens of years of experience and operations, in particular by drawing lessons from the most significant events in its history, such as the Fukushima accident. The new generations of reactors must improve safety and economic performance so that the industry maintain its legitimacy and its share in the production of electricity. This article draws the history of nuclear power in France, gives a brief description of the pressurized water reactor design, lists the technical features of the different versions of PWR that operate in France and compares them with other types of reactors. The feedback experience concerning safety, learnt from the major nuclear accidents Three Miles Island (1979), Chernobyl (1986) and Fukushima (2011) is also detailed. Today there are 26 third generation reactors being built in the world: 4 EPR (1 in Finland, 1 in France and 2 in China); 2 VVER-1200 in Russia, 8 AP-1000 (4 in China and 4 in the Usa), 8 APR-1400 (4 in Korea and 4 in UAE), and 4 ABWR (2 in Japan and 2 in Taiwan)

  14. Reactor Structural Materials: Reactor Pressure Vessel Steels

    Energy Technology Data Exchange (ETDEWEB)

    Chaouadi, R

    2000-07-01

    The objectives of SCK-CEN's R and D programme on Rector Pressure Vessel (RPV) Steels are:(1) to complete the fracture toughness data bank of various reactor pressure vessel steels by using precracked Charpy specimens that were tested statically as well as dynamically; (2) to implement the enhanced surveillance approach in a user-friendly software; (3) to improve the existing reconstitution technology by reducing the input energy (short cycle welding) and modifying the stud geometry. Progress and achievements in 1999 are reported.

  15. Mimic of OSU research reactor

    International Nuclear Information System (INIS)

    The Ohio State University research reactor (OSURR) is undergoing improvements in its research and educational capabilities. A computer-based digital data acquisition system, including a reactor system mimic, will be installed as part of these improvements. The system will monitor the reactor system parameters available to the reactor operator either in digital parameters available to the reactor operator either in digital or analog form. The system includes two computers. All the signals are sent to computer 1, which processes the data and sends the data through a serial port to computer 2 with a video graphics array VGA monitor, which is utilized to display the mimic system of the reactor

  16. Methanation assembly using multiple reactors

    Science.gov (United States)

    Jahnke, Fred C.; Parab, Sanjay C.

    2007-07-24

    A methanation assembly for use with a water supply and a gas supply containing gas to be methanated in which a reactor assembly has a plurality of methanation reactors each for methanating gas input to the assembly and a gas delivery and cooling assembly adapted to deliver gas from the gas supply to each of said methanation reactors and to combine water from the water supply with the output of each methanation reactor being conveyed to a next methanation reactor and carry the mixture to such next methanation reactor.

  17. MINT research reactor safety program

    Energy Technology Data Exchange (ETDEWEB)

    Mohamad Idris bin Taib [Division of Special Project, Malaysian Institute for Nuclear Technology Research (MINT), Bangi (Malaysia)

    2000-11-01

    Malaysian Institute for Nuclear Technology Research (MINT) Research Reactor Safety Program has been done along with Reactor Power Upgrading Project, Reactor Safety Upgrading Project and Development of Expert System for On-Line Nuclear Process Control Project. From 1993 up to date, Neutronic and Thermal-hydraulics analysis, Probabilistic Safety Assessment as well as installation of New 2 MW Secondary Cooling System were done. Installations of New Reactor Building Ventilation System, Reactor Monitoring System, Updating of Safety Analysis Report and Upgrading Primary Cooling System are in progress. For future activities, Reactor Modeling will be included to add present activities. (author)

  18. Thermionic Reactor Design Studies

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred

    1994-08-01

    Paper presented at the 29th IECEC in Monterey, CA in August 1994. The present paper describes some of the author's conceptual designs and their rationale, and the special analytical techniques developed to analyze their (thermionic reactor) performance. The basic designs, first published in 1963, are based on single-cell converters, either double-ended diodes extending over the full height of the reactor core or single-ended diodes extending over half the core height. In that respect they are similar to the thermionic fuel elements employed in the Topaz-2 reactor subsequently developed in the Soviet Union, copies of which were recently imported by the U.S. As in the Topaz-2 case, electrically heated steady-state performance tests of the converters are possible before fueling.

  19. International Thermonuclear Experimental Reactor

    International Nuclear Information System (INIS)

    An international design team comprised of members from Canada, Europe, Japan, the Soviet Union, and the United States of America, are designing an experimental fusion test reactor. The engineering and testing objectives of this International Thermonuclear Experimental Reactor (ITER) are to validate the design and to demonstrate controlled ignition, extended burn of a deuterium and tritium plasma, and achieve steady state using technology expected to be available by 1990. The concept maximizes flexibility while allowing for a variety of plasma configurations and operating scenarios. During physics phase operation, the machine produces a 22 MA plasma current. In the technology phase, the machine can be reconfigured with a thicker shield and a breeding blanket to operate with an 18 MA plasma current at a major radius of 5.5 meters. Canada's involvement in the areas of safety, facility design, reactor configuration and maintenance builds on our internationally recognized design and operational expertise in developing tritium processes and CANDU related technologies

  20. Licensed operating reactors

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission's monthly Licensed Operating Reactors Status Summary Report provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management, from the Headquarters Staff of NRC's Office of Inspection and Enforcement, from NRC's Regional Offices, and from utilities. This report is divided into three sections: the first contains monthly highlights and statistics for commercial operating units, and errata from previously reported data; the second is a compilation of detailed information on each unit, provided by NRC Regional Offices, IE Headquarters and the Utilities; and the third section is an appendix for miscellaneous information such as spent fuel storage capability, reactor years of experience and non-power reactors in the United States

  1. Licensed operating reactors

    International Nuclear Information System (INIS)

    THE OPERATING UNITS STATUS REPORT - LICENSED OPERATING REACTORS provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management from the Headquarters staff of NRC's Office of Enforcement (OE), from NRC's Regional Offices, and from utilities. The three sections of the report are: monthly highlights and statistics for commercial operating units, and errata from previously reported data; a compilation of detailed information on each unit, provided by NRC's Regional Offices, OE Headquarters and the utilities; and an appendix for miscellaneous information such as spent fuel storage capability, reactor-years of experience and non-power reactors in the US

  2. Licensed operating reactors

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission's monthly LICENSED OPERATING REACTORS Status Summary Report provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management, from the Headquarters Staff of NRC's Office of Inspection and Enforcement, from NRC's Regional Offices, and from utilities. This report is divided into three sections: the first contains monthly highlights and statistics for commercial operating units, and errata from previously reported data; the second is a compilation of detailed information on each unit, provided by NRC Regional Offices, IE Headquarters and the Utilities; and the third section is an appendix for miscellaneous information such as spent fuel storage capability, reactor years of experience and non-power reactors in the United States

  3. Reactor safety equipments

    International Nuclear Information System (INIS)

    Purpose: To positively recover radioactive substances discharged in a dry well at the time of failure of a reactor. Constitution: In addition to the emergency gas treating system fitted to a reactor building, a purification system connected through a pipeline to the dry well is arranged in the reactor building. This purification system is connected through pipes fitted to the dry well to forced circulation device, heat exchanger, and purification device. The atmosphere of high pressure steam gases in the dry well is derived to the heat exchanger for cooling, and then radioactive substances which are contained in the gases are removed by filter sets charged with the HEPA filters and the HECA filters. At last, there gases are returned to dry well by circulation pump, repeat this process. (Kamimura, M.)

  4. Licensed operating reactors

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission's monthly LICENSED OPERATING REACTORS Status Summary Report provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management, from the Headquarters Staff of NRC's Office of Inspection and Enforcement, from NRC's Regional Offices, and from utilities. This report is divided into three sections: the first contains monthly highlights and statistics for commercial operating units, and errata from previously reported data; the second is a compilation of detailed information on each unit, provided by NRC Regional Offices, IE Headquarters and the utilities; and the third section is an appendix for miscellaneous information such as spent fuel storage capability, reactor years of experience and non-power reactors in the United States

  5. Welding and reactor safety

    International Nuclear Information System (INIS)

    The high safety requirements which must be demanded of the quality of the welded joints in reactor technique have so far not been fulfilled in all cases. The errors occuring have caused considerable loss of availability and high material costs. They were not, however, so serious that one need have feared any immediate danger to the personnel or to the environment. The safety devices of reactor plants were only called upon in a few cases and to these they responded perfectly. The intensive efforts to complete and improve the specifications are to contribute to that in future, the reactor plants can be counted even more so as one of the safest technical plants ever. (orig./LH)

  6. Backfitting swimming pool reactors

    International Nuclear Information System (INIS)

    Calculations based on measurements in a critical assembly, and experiments to disclose fuel element surface temperatures in case of accidents like stopping of primary coolant flow during full power operation, have shown that the power of the swimming pool type research reactor FRG-2 (15 MW, operating since 1967) might be raised to 21 MW within the present rules of science and technology, without major alterations of the pool buildings and the cooling systems. A backfitting program is carried through to adjust the reactor control systems of FRG-2 and FRG-1 (5 MW, housed in the same reactor hall) to the present safety rules and recommendations, to ensure FRG-2 operation at 21 MW for the next decade. (author)

  7. Reactor operation experience

    International Nuclear Information System (INIS)

    Since the TRIGA Users Conference in Helsinki 1970 the TRIGA reactor Vienna was in operation without any larger undesired shutdown. The integrated thermal power production by August 15 1972 accumulated to 110 MWd. The TRIGA reactor is manly used for training of students, for scientific courses and research work. Cooperation with industry increased in the last two years either in form of research or in performing training courses. Close cooperation is also maintained with the IAEA, samples are irradiated and courses on various fields are arranged. Maintenance work was performed on the heat exchanger and to replace the shim rod magnet. With the view on the future power upgrading nine fuel elements type 110 have been ordered recently. Experiments, performed currently on the reactor are presented in details

  8. The MNSR reactor

    International Nuclear Information System (INIS)

    This tank-in-pool reactor is based on the same design concept as the Canadian Slowpoke. The core is a right circular cylinder, 24 cm diameter by 25 cm long, containing 411 fuel pin positions. The pins are HEU-Aluminium alloy, 0.5 cm in diameter. Critical mass is about 900 g. The reactor has a single cadmium control rod. The back-up shutdown system is the insertion of a cadmium capsule in a core position. Excess reactivity is limited to 3.5mk. In both the MNSR and Slowpoke, the insertion of the maximum excess reactivity results in a power transient limited by the coolant/moderator temperature to safe values, independent of any operator action. This reactor is used primarily in training and neutron activation analysis. Up to 64 elements have been analyzed in a great variety of different disciplines. (author)

  9. Nuclear Rocket Engine Reactor

    CERN Document Server

    Lanin, Anatoly

    2013-01-01

    The development of a nuclear rocket engine reactor (NRER ) is presented in this book. The working capacity of an active zone NRER under mechanical and thermal load, intensive neutron fluxes, high energy generation (up to 30 MBT/l) in a working medium (hydrogen) at temperatures up to 3100 K is displayed. Design principles and bearing capacity of reactors area discussed on the basis of simulation experiments and test data of a prototype reactor. Property data of dense constructional, porous thermal insulating and fuel materials like carbide and uranium carbide compounds in the temperatures interval 300 - 3000 K are presented. Technological aspects of strength and thermal strength resistance of materials are considered. The design procedure of possible emergency processes in the NRER is developed and risks for their origination are evaluated. Prospects of the NRER development for pilotless space devices and piloted interplanetary ships are viewed.

  10. Fusion reactor materials

    International Nuclear Information System (INIS)

    This is the fifteenth in a series of semiannual technical progress reports on fusion reactor materials. This report combines research and development activities which were previously reported separately in the following progress reports: Alloy Development for Irradiation Performance; Damage Analysis and Fundamental Studies; Special purpose Materials. These activities are concerned principally with the effects of the neutronic and chemical environment on the properties and performance of reactor materials; together they form one element of the overall materials programs being conducted in support of the Magnetic Fusion Energy Program of the U.S. Department of Energy. The Fusion Reactor Materials Program is a national effort involving several national laboratories, universities, and industries. The purpose of this series of reports is to provide a working technical record for the use of the program participants, and to provide a means of communicating the efforts of materials scientists to the rest of the fusion community, both nationally and worldwide

  11. Safety systems of heavy water reactors and small power reactors

    International Nuclear Information System (INIS)

    After introductional descriptions of heavy water reactors and natural circulation boiling water reactors the safety philosophy and safety systems like ECCS, residual heat removal, protection systems etc., are described. (RW)

  12. AREVA's nuclear reactors portfolio

    International Nuclear Information System (INIS)

    A reasonable assumption for the estimated new build market for the next 25 years is over 340 GWe net. The number of prospect countries is growing almost each day. To address this new build market, AREVA is developing a comprehensive portfolio of reactors intended to meet a wide range of power requirements and of technology choices. The EPR reactor is the flagship of the fleet. Intended for large power requirements, the four first EPRs are being built in Finland, France and China. Other countries and customers are in view, citing just two examples: the Usa where the U.S. EPR has been selected as the technology of choice by several U.S utilities; and the United Kingdom where the Generic Design Acceptance process of the EPR design submitted by AREVA and EDF is well under way, and where there is a strong will to have a plant on line in 2017. For medium power ranges, the AREVA portfolio includes a boiling water reactor and a pressurized water reactor which both offer all of the advantages of an advanced plant design, with excellent safety performance and competitive power generation cost: -) KERENA (1250+ MWe), developed in collaboration with several European utilities, and in particular with Eon; -) ATMEA 1 (1100+ MWe), a 3-loop evolutionary PWR which is being developed by AREVA and Mitsubishi. AREVA is also preparing the future and is deeply involved into Gen IV concepts. It has developed the ANTARES modular HTR reactor (pre-conceptual design completed) and is building upon its vast Sodium Fast Reactor experience to take part into the development of the next prototype. (author)

  13. Oscillatory flow chemical reactors

    Directory of Open Access Journals (Sweden)

    Slavnić Danijela S.

    2014-01-01

    Full Text Available Global market competition, increase in energy and other production costs, demands for high quality products and reduction of waste are forcing pharmaceutical, fine chemicals and biochemical industries, to search for radical solutions. One of the most effective ways to improve the overall production (cost reduction and better control of reactions is a transition from batch to continuous processes. However, the reactions of interests for the mentioned industry sectors are often slow, thus continuous tubular reactors would be impractically long for flow regimes which provide sufficient heat and mass transfer and narrow residence time distribution. The oscillatory flow reactors (OFR are newer type of tube reactors which can offer solution by providing continuous operation with approximately plug flow pattern, low shear stress rates and enhanced mass and heat transfer. These benefits are the result of very good mixing in OFR achieved by vortex generation. OFR consists of cylindrical tube containing equally spaced orifice baffles. Fluid oscillations are superimposed on a net (laminar flow. Eddies are generated when oscillating fluid collides with baffles and passes through orifices. Generation and propagation of vortices create uniform mixing in each reactor cavity (between baffles, providing an overall flow pattern which is close to plug flow. Oscillations can be created by direct action of a piston or a diaphragm on fluid (or alternatively on baffles. This article provides an overview of oscillatory flow reactor technology, its operating principles and basic design and scale - up characteristics. Further, the article reviews the key research findings in heat and mass transfer, shear stress, residence time distribution in OFR, presenting their advantages over the conventional reactors. Finally, relevant process intensification examples from pharmaceutical, polymer and biofuels industries are presented.

  14. Reactor Materials Research

    International Nuclear Information System (INIS)

    The activities of SCK-CEN's Reactor Materials Research Department for 2001 are summarised. The objectives of the department are: (1) to evaluate the integrity and behaviour of structural materials used in nuclear power industry; (2) to conduct research to unravel and understand the parameters that determine the material behaviour under or after irradiation; (3) to contribute to the interpretation, the modelling of the material behaviour and to develop and assess strategies for optimum life management of nuclear power plant components. The programmes within the department are focussed on studies concerning (1) Irradiation Assisted Stress Corrosion Cracking (IASCC); (2) nuclear fuel; and (3) Reactor Pressure Vessel Steel

  15. Nuclear reactor simulator

    International Nuclear Information System (INIS)

    The Nuclear Reactor Simulator was projected to help the basic training in the formation of the Nuclear Power Plants operators. It gives the trainee the opportunity to see the nuclear reactor dynamics. It's specially indicated to be used as the support tool to NPPT (Nuclear Power Preparatory Training) from NUS Corporation. The software was developed to Intel platform (80 x 86, Pentium and compatible ones) working under the Windows operational system from Microsoft. The program language used in development was Object Pascal and the compiler used was Delphi from Borland. During the development, computer algorithms were used, based in numeric methods, to the resolution of the differential equations involved in the process. (author)

  16. Diagnostics for hybrid reactors

    International Nuclear Information System (INIS)

    The Hybrid Reactor(HR) can be considered an attractive actinide-burner or a fusion assisted transmutation for destruction of transuranic(TRU) nuclear waste. The hybrid reactor has two important subsystems: the tokamak neutron source and the blanket which includes a fuel zone where the TRU are placed and a tritium breeding zone. The diagnostic system for a HR must be as simple and robust as possible to monitor and control the plasma scenario, guarantee the protection of the machine and monitor the transmutation.

  17. Small mirror fusion reactors

    International Nuclear Information System (INIS)

    Basic requirements for the pilot plants are that they produce a net product and that they have a potential for commercial upgrade. We have investigated a small standard mirror fusion-fission hybrid, a two-component tandem mirror hybrid, and two versions of a field-reversed mirror fusion reactor--one a steady state, single cell reactor with a neutral beam-sustained plasma, the other a moving ring field-reversed mirror where the plasma passes through a reaction chamber with no energy addition

  18. Reactor neutron dosimetry

    International Nuclear Information System (INIS)

    An analysis of requirements and possibilities for experimental neutron spectrum determination during the reactor pressure vessel surveil lance programme is given. Fast neutron spectrum and neutron dose rate were measured in the Fast neutron irradiation facility of our TRIGA reactor. It was shown that the facility can be used for calibration of neutron dosimeters and for irradiation of samples sensitive to neutron radiation. The investigation of the unfolding algorithm ITER was continued. Based on this investigations are two specialized unfolding program packages ITERAD and ITERGS written this year. They are able to unfold data from activation detectors and NaI(T1) gamma spectrometer respectively

  19. Perspectives on reactor safety

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission (NRC) maintains a technical training center at Chattanooga, Tennessee to provide appropriate training to both new and experienced NRC employees. This document describes a one-week course in reactor, safety concepts. The course consists of five modules: (1) historical perspective; (2) accident sequences; (3) accident progression in the reactor vessel; (4) containment characteristics and design bases; and (5) source terms and offsite consequences. The course text is accompanied by slides and videos during the actual presentation of the course

  20. Perspectives on reactor safety

    Energy Technology Data Exchange (ETDEWEB)

    Haskin, F.E. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering; Camp, A.L. [Sandia National Labs., Albuquerque, NM (United States)

    1994-03-01

    The US Nuclear Regulatory Commission (NRC) maintains a technical training center at Chattanooga, Tennessee to provide appropriate training to both new and experienced NRC employees. This document describes a one-week course in reactor, safety concepts. The course consists of five modules: (1) historical perspective; (2) accident sequences; (3) accident progression in the reactor vessel; (4) containment characteristics and design bases; and (5) source terms and offsite consequences. The course text is accompanied by slides and videos during the actual presentation of the course.

  1. Nuclear reactor constructions

    International Nuclear Information System (INIS)

    A nuclear reactor construction comprising a reactor core submerged in a pool of liquid metal coolant in a primary vessel which is suspended from the roof structure of a containment vault. Control rods supported from the roof structure are insertable in the core which is carried on a support structure from the wall of the primary vessel. To prevent excessive relaxation of the support structure whereby the control rods would be displaced relative to the core, the support structure incorporates a normally inactive secondary structure designed to become effective in bracing the primary structure against further relaxation beyond a predetermined limit. (author)

  2. Fusion Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2000-07-01

    SCK-CEN's research and development programme on fusion reactor materials includes: (1) the study of the mechanical behaviour of structural materials under neutron irradiation (including steels, inconel, molybdenum, chromium); (2) the determination and modelling of the characteristics of irradiated first wall materials such as beryllium; (3) the detection of abrupt electrical degradation of insulating ceramics under high temperature and neutron irradiation; (4) the study of the dismantling and waste disposal strategy for fusion reactors.; (5) a feasibility study for the testing of blanket modules under neutron radiation. Main achievements in these topical areas in the year 1999 are summarised.

  3. Reactor gamma spectrometry: status

    International Nuclear Information System (INIS)

    Current work is described for Compton Recoil Gamma-Ray Spectrometry including developments in experimental technique as well as recent reactor spectrometry measurements. The current status of the method is described concerning gamma spectromoetry probe design and response characteristics. Emphasis is given to gamma spectrometry work in US LWR and BR programs. Gamma spectrometry in BR environments are outlined by focussing on start-up plans for the Fast Test Reactor (FTR). Gamma spectrometry results are presented for a LWR pressure vessel mockup in the Poolside Critical Assembly (PCA) at Oak Ridge National Laboratory

  4. Reactor Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Van Walle, E

    2002-04-01

    The activities of SCK-CEN's Reactor Materials Research Department for 2001 are summarised. The objectives of the department are: (1) to evaluate the integrity and behaviour of structural materials used in nuclear power industry; (2) to conduct research to unravel and understand the parameters that determine the material behaviour under or after irradiation; (3) to contribute to the interpretation, the modelling of the material behaviour and to develop and assess strategies for optimum life management of nuclear power plant components. The programmes within the department are focussed on studies concerning (1) Irradiation Assisted Stress Corrosion Cracking (IASCC); (2) nuclear fuel; and (3) Reactor Pressure Vessel Steel.

  5. Risk prevention during reactor shutdown

    International Nuclear Information System (INIS)

    During reactor shutdown potential risks are issued of a number of maintenance operations. In this text we analyse these operations and give the modifications of technical specifications to ameliorate the reactor safety. 4 figs

  6. Power calibrations for TRIGA reactors

    International Nuclear Information System (INIS)

    The purpose of this paper is to establish a framework for the calorimetric power calibration of TRIGA reactors so that reliable results can be obtained with a precision better than ± 5%. Careful application of the same procedures has produced power calibration results that have been reproducible to ± 1.5%. The procedures are equally applicable to the Mark I, Mark II and Mark III reactors as well as to reactors having much larger reactor tanks and to TRIGA reactors capable of forced cooling up to 3 MW in some cases and 15 MW in another case. In the case of forced cooled TRIGA reactors, the calorimetric power calibration is applicable in the natural convection mode for these reactors using exactly the same procedures as are discussed below for the smaller TRIGA reactors (< 2 MW)

  7. Reactor Engineering Department annual report

    International Nuclear Information System (INIS)

    Research and development activities in the Department of Reactor Engineering in fiscal 1982 are described. The work of the Department is closely related to development of multipurpose Very High Temperature Gas Cooled Reactor and Fusion Reactor, and development of Liquid Metal Fast Breeder Reactor carried out by Power Reactor and Nuclear Fuel Development Corporation. Since fiscal 1982, Systematic research and development work on safeguards technology has been added to the activities of the Department. Contents of the report are achievements in fields such as nuclear data and group constants, theoretical method and code development, integral experiment and analysis, fusion neutronics, shielding, reactor and nuclear instrumentation, reactor control and diagnosis, and safeguards technology, and activities of the Committee on Reactor Physics. (author)

  8. Operating reactors licensing actions summary

    International Nuclear Information System (INIS)

    The Operating Reactors Licensing Actions Summary is designed to provide the management of the Nuclear Regulatory Commission (NRC) with an overview of licensing actions dealing with operating power and nonpower reactors

  9. Reactor operation environmental information document

    Energy Technology Data Exchange (ETDEWEB)

    Haselow, J.S.; Price, V.; Stephenson, D.E.; Bledsoe, H.W.; Looney, B.B.

    1989-12-01

    The Savannah River Site (SRS) produces nuclear materials, primarily plutonium and tritium, to meet the requirements of the Department of Defense. These products have been formed in nuclear reactors that were built during 1950--1955 at the SRS. K, L, and P reactors are three of five reactors that have been used in the past to produce the nuclear materials. All three of these reactors discontinued operation in 1988. Currently, intense efforts are being extended to prepare these three reactors for restart in a manner that protects human health and the environment. To document that restarting the reactors will have minimal impacts to human health and the environment, a three-volume Reactor Operations Environmental Impact Document has been prepared. The document focuses on the impacts of restarting the K, L, and P reactors on both the SRS and surrounding areas. This volume discusses the geology, seismology, and subsurface hydrology. 195 refs., 101 figs., 16 tabs.

  10. High Flux Isotope Reactor (HFIR)

    Data.gov (United States)

    Federal Laboratory Consortium — The HFIR at Oak Ridge National Laboratory is a light-water cooled and moderated reactor that is the United States’ highest flux reactor-based neutron source. HFIR...

  11. Reactor operation safety information document

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The report contains a reactor facility description which includes K, P, and L reactor sites, structures, operating systems, engineered safety systems, support systems, and process and effluent monitoring systems; an accident analysis section which includes cooling system anomalies, radioactive materials releases, and anticipated transients without scram; a summary of onsite doses from design basis accidents; severe accident analysis (reactor core disruption); a description of operating contractor organization and emergency planning; and a summary of reactor safety evolution. (MB)

  12. Reactor safety in Eastern Europe

    International Nuclear Information System (INIS)

    The papers presented to the GRS colloquium refer to the cooperative activities for reactor accident analysis and modification of the GRS computer codes for their application to reactors of the Russian design types of WWER or RBMK. Another topic is the safety of RBMK reactors in particular, and the current status of investigations and studies addressing the containment of unit 4 of the Chernobyl reactor station. All papers are indexed separately in report GRS--117. (HP)

  13. Fast reactor programme

    International Nuclear Information System (INIS)

    This progress report summarizes the fast reactor research carried out by ECN during the period covering the year 1980. This research is mainly concerned with the cores of sodium-cooled breeders, in particular the SNR-300, and its related safety aspects. It comprises six items: A programme to determine relevant nuclear data of fission- and corrosion-products; A fuel performance programme comprising in-pile cladding failure experiments and a study of the consequences of loss-of-cooling and overpower; Basic research on fuel; Investigation of the changes in the mechanical properties of austenitic stainless steel DIN 1.4948 due to fast neutron doses, this material has been used in the manufacture of the reactor vessel and its internal components; Study of aerosols which could be formed at the time of a fast reactor accident and their progressive behaviour on leaking through cracks in the concrete containment; Studies on heat transfer in a sodium-cooled fast reactor core. As fast breeders operate at high power densities, an accurate knowledge of the heat transfer phenomena under single-phase and two-phase conditions is sought. (Auth.)

  14. Thermal Reactor Safety

    International Nuclear Information System (INIS)

    Information is presented concerning fire risk and protection; transient thermal-hydraulic analysis and experiments; class 9 accidents and containment; diagnostics and in-service inspection; risk and cost comparison of alternative electric energy sources; fuel behavior and experiments on core cooling in LOCAs; reactor event reporting analysis; equipment qualification; post facts analysis of the TMI-2 accident; and computational methods

  15. NEUTRONIC REACTOR FUEL ELEMENT

    Science.gov (United States)

    Picklesimer, M.L.; Thurber, W.C.

    1961-01-01

    A chemically nonreactive fuel composition for incorporation in aluminum- clad, plate type fuel elements for neutronic reactors is described. The composition comprises a mixture of aluminum and uranium carbide particles, the uranium carbide particles containing at least 80 wt.% UC/sub 2/.

  16. Stabilized Spheromak Fusion Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, T

    2007-04-03

    The U.S. fusion energy program is focused on research with the potential for studying plasmas at thermonuclear temperatures, currently epitomized by the tokamak-based International Thermonuclear Experimental Reactor (ITER) but also continuing exploratory work on other plasma confinement concepts. Among the latter is the spheromak pursued on the SSPX facility at LLNL. Experiments in SSPX using electrostatic current drive by coaxial guns have now demonstrated stable spheromaks with good heat confinement, if the plasma is maintained near a Taylor state, but the anticipated high current amplification by gun injection has not yet been achieved. In future experiments and reactors, creating and maintaining a stable spheromak configuration at high magnetic field strength may require auxiliary current drive using neutral beams or RF power. Here we show that neutral beam current drive soon to be explored on SSPX could yield a compact spheromak reactor with current drive efficiency comparable to that of steady state tokamaks. Thus, while more will be learned about electrostatic current drive in coming months, results already achieved in SSPX could point to a productive parallel development path pursuing auxiliary current drive, consistent with plans to install neutral beams on SSPX in the near future. Among possible outcomes, spheromak research could also yield pulsed fusion reactors at lower capital cost than any fusion concept yet proposed.

  17. Reactors. Nuclear propulsion ships

    International Nuclear Information System (INIS)

    This article has for object the development of nuclear-powered ships and the conception of the nuclear-powered ship. The technology of the naval propulsion P.W.R. type reactor is described in the article B.N.3 141 'Nuclear Boilers ships'. (N.C.)

  18. Pressure tube type reactor

    International Nuclear Information System (INIS)

    Heretofore, a pressure tube type reactor has a problem in that the evaluation for the reactor core performance is complicate and no sufficient consideration is made for the economical property, to increase the size of a calandria tank and make the cost expensive. Then, in the present invention, the inner diameter of a pressure tube is set to greater than 50% of the lattice gap in a square lattice like arrangement, and the difference between the inner and the outer diameters of the calandria tube is set smaller than 20% of the lattice gap. Further, the inner diameter of the pressure tube is set to greater than 40% and the difference between the inner and the outer diameters of the calandria tube is set smaller than 30% of the lattice gap in a triangle lattice arrangement. Then, heavy water-to-fuel volume ratio can be determined appropriately and the value for the coolant void coefficient is made more negative side, to improve the self controllability inherent to the reactor. In particular, when 72 to 90 fuel rods are arranged per one pressure tube, the power density per one fuel rod is can be increased by about twice. Accordingly, the number of the pressure tubes can be reduced about to one-half, thereby enabling to remarkably decrease the diameter of the reactor core and to reduce the size of the calandria, which is economical. (N.H.)

  19. Fusion reactor materials

    International Nuclear Information System (INIS)

    At the Belgian Nuclear Research Centre SCK-CEN, activities related to fusion focus on environmental tolerance of opto-electronic components. The objective of this program is to contribute to the knowledge on the behaviour, during and after neutron irradiation, of fusion-reactor materials and components. The main scientific activities for 1997 are summarized

  20. Integral Fast Reactor Program

    International Nuclear Information System (INIS)

    This report summarizes highlights of the technical progress made in the Integral Fast Reactor (IFR) Program in FY 1992. Technical accomplishments are presented in the following areas of the IFR technology development activities: (1) metal fuel performance, (2) pyroprocess development, (3) safety experiments and analyses, (4) core design development, (5) fuel cycle demonstration, and (6) LMR technology R ampersand D

  1. Nuclear reactor building

    Science.gov (United States)

    Gou, Perng-Fei; Townsend, Harold E.; Barbanti, Giancarlo

    1994-01-01

    A reactor building for enclosing a nuclear reactor includes a containment vessel having a wetwell disposed therein. The wetwell includes inner and outer walls, a floor, and a roof defining a wetwell pool and a suppression chamber disposed thereabove. The wetwell and containment vessel define a drywell surrounding the reactor. A plurality of vents are disposed in the wetwell pool in flow communication with the drywell for channeling into the wetwell pool steam released in the drywell from the reactor during a LOCA for example, for condensing the steam. A shell is disposed inside the wetwell and extends into the wetwell pool to define a dry gap devoid of wetwell water and disposed in flow communication with the suppression chamber. In a preferred embodiment, the wetwell roof is in the form of a slab disposed on spaced apart support beams which define therebetween an auxiliary chamber. The dry gap, and additionally the auxiliary chamber, provide increased volume to the suppression chamber for improving pressure margin.

  2. Studies on reactor physics

    International Nuclear Information System (INIS)

    Most of the peaceful applications of atomic energy are inherently dependent on advances in the science and technology of nuclear reactors, and aspects of this development are part of a major programme of the International Atomic Energy Agency. The most useful role that the Agency can play is as a co-ordinating body or central forum where the trends can be reviewed and the results assessed. Some of the basic studies are carried out by members of the Agency's own scientific staff. The Agency also convenes groups of experts from different countries to examine a particular problem in detail and make any necessary recommendations. Some of the important subjects are discussed at international scientific meetings held by the Agency. One of the subjects covered by such studies is the physics of nuclear reactors and a specific topic recently discussed was Codes for Reactor Computations, on which a seminar was held in Vienna in April this year. Another The members of the Panel described the development of heavy water reactors, the equipment and methods of research currently used, and plans for further development in their respective countries meeting of Panel of Experts on Heavy Water Lattices was held in Vienna in August 1959

  3. Nuclear power reactor physics

    International Nuclear Information System (INIS)

    The purpose of this book is to explain the physical working conditions of nuclear reactors for the benefit of non-specialized engineers and engineering students. One of the leading ideas of this course is to distinguish between two fundamentally different concepts: - a science which could be called neutrodynamics (as distinct from neutron physics which covers the knowledge of the neutron considered as an elementary particle and the study of its interactions with nuclei); the aim of this science is to study the interaction of the neutron gas with real material media; the introduction will however be restricted to its simplified expression, the theory and equation of diffusion; - a special application: reactor physics, which is introduced when the diffusing and absorbing material medium is also multiplying. For this reason the chapter on fission is used to introduce this section. In practice the section on reactor physics is much longer than that devoted to neutrodynamics and it is developed in what seemed to be the most relevant direction: nuclear power reactors. Every effort was made to meet the following three requirements: to define the physical bases of neutron interaction with different materials, to give a correct mathematical treatment within the limit of necessary simplifying hypotheses clearly explained; to propose, whenever possible, numerical applications in order to fix orders of magnitude

  4. Cermet fuel reactors

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, C.L.; Palmer, R.S.; Van Hoomissen, J.E.; Bhattacharyya, S.K.; Barner, J.O.

    1987-09-01

    Cermet fueled nuclear reactors are attractive candidates for high performance space power systems. The cermet fuel consists of tungsten-urania hexagonal fuel blocks characterized by high strength at elevated temperatures, a high thermal conductivity and resultant high thermal shock resistance. Key features of the cermet fueled reactor design are (1) the ability to achieve very high coolant exit temperatures, and (2) thermal shock resistance during rapid power changes, and (3) two barriers to fission product release - the cermet matrix and the fuel element cladding. Additionally, thre is a potential for achieving a long operating life because of (1) the neutronic insensitivity of the fast-spectrum core to the buildup of fission products and (2) the utilization of a high strength refractory metal matrix and structural materials. These materials also provide resistance against compression forces that potentially might compact and/or reconfigure the core. In addition, the neutronic properties of the refractory materials assure that the reactor remains substantially subcritical under conditions of water immersion. It is concluded that cermet fueled reactors can be utilized to meet the power requirements for a broad range of advanced space applications. 4 refs., 4 figs., 3 tabs.

  5. Cermet fuel reactors

    International Nuclear Information System (INIS)

    Cermet fueled nuclear reactors are attractive candidates for high performance space power systems. The cermet fuel consists of tungsten-urania hexagonal fuel blocks characterized by high strength at elevated temperatures, a high thermal conductivity and resultant high thermal shock resistance. Key features of the cermet fueled reactor design are (1) the ability to achieve very high coolant exit temperatures, and (2) thermal shock resistance during rapid power changes, and (3) two barriers to fission product release - the cermet matrix and the fuel element cladding. Additionally, thre is a potential for achieving a long operating life because of (1) the neutronic insensitivity of the fast-spectrum core to the buildup of fission products and (2) the utilization of a high strength refractory metal matrix and structural materials. These materials also provide resistance against compression forces that potentially might compact and/or reconfigure the core. In addition, the neutronic properties of the refractory materials assure that the reactor remains substantially subcritical under conditions of water immersion. It is concluded that cermet fueled reactors can be utilized to meet the power requirements for a broad range of advanced space applications. 4 refs., 4 figs., 3 tabs

  6. The Chernobyl reactor accident

    International Nuclear Information System (INIS)

    The documentation abstracted contains a complete survey of the broadcasts transmitted by the Russian wire service of the Deutsche Welle radio station between April 28 and Mai 15, 1986 on the occasion of the Chernobyl reactor accident. Access is given to extracts of the remarkable eastern and western echoes on the broadcasts of the Deutsche Welle. (HP)

  7. SRP reactor safety evolution

    International Nuclear Information System (INIS)

    The Savannah River Plant reactors have operated for over 100 reactor years without an incident of significant consequence to on or off-site personnel. The reactor safety posture incorporates a conservative, failure-tolerant design; extensive administrative controls carried out through detailed operating and emergency written procedures; and multiple engineered safety systems backed by comprehensive safety analyses, adapting through the years as operating experience, changes in reactor operational modes, equipment modernization, and experience in the nuclear power industry suggested. Independent technical reviews and audits as well as a strong organizational structure also contribute to the defense-in-depth safety posture. A complete review of safety history would discuss all of the above contributors and the interplay of roles. This report, however, is limited to evolution of the engineered safety features and some of the supporting analyses. The discussion of safety history is divided into finite periods of operating history for preservation of historical perspective and ease of understanding by the reader. Programs in progress are also included. The accident at Three Mile Island was assessed for its safety implications to SRP operation. Resulting recommendations and their current status are discussed separately at the end of the report. 16 refs., 3 figs

  8. Fusion reactor materials

    International Nuclear Information System (INIS)

    This paper discuses the following topics on fusion reactor materials: irradiation, facilities, test matrices, and experimental methods; dosimetry, damage parameters, and activation calculations; materials engineering and design requirements; fundamental mechanical behavior; radiation effects; development of structural alloys; solid breeding materials; and ceramics

  9. Thermal Reactor Safety

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    Information is presented concerning fire risk and protection; transient thermal-hydraulic analysis and experiments; class 9 accidents and containment; diagnostics and in-service inspection; risk and cost comparison of alternative electric energy sources; fuel behavior and experiments on core cooling in LOCAs; reactor event reporting analysis; equipment qualification; post facts analysis of the TMI-2 accident; and computational methods.

  10. Department of reactor technology

    International Nuclear Information System (INIS)

    The activities of the Department of Reactor Technology at Risoe during 1980 are described. The work is presented in three chapters: General Information on the Department, Summary of the Department's Development during 1980, and Activities of the Department. Lists of staff, publications, computer programs, and test facilities are included. (author)

  11. The AP1000 reactor

    International Nuclear Information System (INIS)

    The design of the AP1000 reactor began 20 years ago when Westinghouse launched the AP600 reactor project. In fact by re-assessing AP600's safety margins Westinghouse realized that the its power output could be raised without putting at risk its safety standard. The AP1000 was born, it yields 1100 MWe. The main AP1000's design features is its passive safety (particularly after the Fukushima accident) and its modularity. The passive safety of the AP1000 implies: -) no humane intervention needed for 72 hours at least after the incident; -) no necessity for redundant complex safety systems. The modularity means that the plant, the reactor and other buildings are constructed from a choice of 300 modular units. These units can be built off-site and fit together on site. The modularity allows more construction activities to be led simultaneously and more chances to cope with the construction schedule. The NRC has approved the operation license for 30 years of the first AP1000 being built in the Usa (Vogtle plant in Georgia). 4 AP1000 are being built in China (Sanmen and Haiyang sites) and 6 others are planned in the Usa. Westinghouse is convinced that the AP1000's passive safety makes it more attractive. Let us not forget that Westinghouse was at the origin of the concept of pressurized water reactors, an idea adopted for half the nuclear power stations in the world and for all the plants now active in France. (A.C.)

  12. Fast reactor programme

    International Nuclear Information System (INIS)

    This progress report summarises the fast reactor research carried out at the Netherlands Energy Research Centre during the year 1981. The neutron and fission product cross sections of various isotopes have been evaluated. In the fuel performance programme, some preliminary results are given and irradiation facilities described. Creep experiments on various stainless steel components are reported

  13. Nuclear rocket engine reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lanin, Anatoly

    2013-07-01

    Covers a new technology of nuclear reactors and the related materials aspects. Integrates physics, materials science and engineering Serves as a basic book for nuclear engineers and nuclear physicists. The development of a nuclear rocket engine reactor (NRER) is presented in this book. The working capacity of an active zone NRER under mechanical and thermal load, intensive neutron fluxes, high energy generation (up to 30 MBT/l) in a working medium (hydrogen) at temperatures up to 3100 K is displayed. Design principles and bearing capacity of reactors area discussed on the basis of simulation experiments and test data of a prototype reactor. Property data of dense constructional, porous thermal insulating and fuel materials like carbide and uranium carbide compounds in the temperatures interval 300 - 3000 K are presented. Technological aspects of strength and thermal strength resistance of materials are considered. The design procedure of possible emergency processes in the NRER is developed and risks for their origination are evaluated. Prospects of the NRER development for pilotless space devices and piloted interplanetary ships are viewed.

  14. Nuclear Reactors and Technology

    Energy Technology Data Exchange (ETDEWEB)

    Cason, D.L.; Hicks, S.C. [eds.

    1992-01-01

    This publication Nuclear Reactors and Technology (NRT) announces on a monthly basis the current worldwide information available from the open literature on nuclear reactors and technology, including all aspects of power reactors, components and accessories, fuel elements, control systems, and materials. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database during the past month. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency`s Energy Technology Data Exchange or government-to-government agreements. The digests in NRT and other citations to information on nuclear reactors back to 1948 are available for online searching and retrieval on the Energy Science and Technology Database and Nuclear Science Abstracts (NSA) database. Current information, added daily to the Energy Science and Technology Database, is available to DOE and its contractors through the DOE Integrated Technical Information System. Customized profiles can be developed to provide current information to meet each user`s needs.

  15. Fusion reactor materials

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1989-01-01

    This paper discuses the following topics on fusion reactor materials: irradiation, facilities, test matrices, and experimental methods; dosimetry, damage parameters, and activation calculations; materials engineering and design requirements; fundamental mechanical behavior; radiation effects; development of structural alloys; solid breeding materials; and ceramics.

  16. Operating reactors licensing actions summary

    International Nuclear Information System (INIS)

    The operating reactors licensing actions summary is designed to provide the management of the Nuclear Regulatory Commission (NRC) with an overview of licensing actions dealing with operating power and nonpower reactors. These reports utilize data collected from the Division of Licensing in the Office of Nuclear Reactor Regulation and are prepared by the Office of Management and Program Analysis

  17. Fast reactors: potential for power

    International Nuclear Information System (INIS)

    The subject is discussed as follows: basic facts about conventional and fast reactors; uranium economy; plutonium and fast reactors; cooling systems; sodium coolant; safety engineering; handling and recycling plutonium; safeguards; development of fast reactors in Britain and abroad; future progress. (U.K.)

  18. Reactor physics problems on HCPWR

    International Nuclear Information System (INIS)

    Reactor physics problems on high conversion pressurized water reactors (HCPWRs) are discussed. Described in this report are outline of the HCPWR, expected accuracy for the various reactor physical qualities, and method for K-effective calculation in the resonance energy area. And requested further research problems are shown. The target value of the conversion ratio are also discussed. (author)

  19. Alternative approaches to fusion. [reactor design and reactor physics for Tokamak fusion reactors

    Science.gov (United States)

    Roth, R. J.

    1976-01-01

    The limitations of the Tokamak fusion reactor concept are discussed and various other fusion reactor concepts are considered that employ the containment of thermonuclear plasmas by magnetic fields (i.e., stellarators). Progress made in the containment of plasmas in toroidal devices is reported. Reactor design concepts are illustrated. The possibility of using fusion reactors as a power source in interplanetary space travel and electric power plants is briefly examined.

  20. Reactor vessel support system. [LMFBR

    Science.gov (United States)

    Golden, M.P.; Holley, J.C.

    1980-05-09

    A reactor vessel support system includes a support ring at the reactor top supported through a box ring on a ledge of the reactor containment. The box ring includes an annular space in the center of its cross-section to reduce heat flow and is keyed to the support ledge to transmit seismic forces from the reactor vessel to the containment structure. A coolant channel is provided at the outside circumference of the support ring to supply coolant gas through the keyways to channels between the reactor vessel and support ledge into the containment space.

  1. Reactor monitoring using antineutrino detectors

    Science.gov (United States)

    Bowden, N. S.

    2011-08-01

    Nuclear reactors have served as the antineutrino source for many fundamental physics experiments. The techniques developed by these experiments make it possible to use these weakly interacting particles for a practical purpose. The large flux of antineutrinos that leaves a reactor carries information about two quantities of interest for safeguards: the reactor power and fissile inventory. Measurements made with antineutrino detectors could therefore offer an alternative means for verifying the power history and fissile inventory of a reactor as part of International Atomic Energy Agency (IAEA) and/or other reactor safeguards regimes. Several efforts to develop this monitoring technique are underway worldwide.

  2. Reactor physics activities in Japan

    International Nuclear Information System (INIS)

    This report reviews the research activity in reactor physics field in Japan during July, 1992 - July, 1993. The review was performed in the following fields : nuclear data evaluation, calculational method development, fast reactor physics, thermal reactor physics, advanced core design, fusion reactor neutronics, nuclear criticality safety, shielding, incineration of radioactive nuclear wastes, noise analysis and control and national programs. The main references were taken from journals and reports published during this period. The research committee of reactor physics is responsible for the review work. (author)

  3. Advanced reactor experimental facilities

    International Nuclear Information System (INIS)

    For many years, the NEA has been examining advanced reactor issues and disseminating information of use to regulators, designers and researchers on safety issues and research needed. Following the recommendation of participants at an NEA workshop, a Task Group on Advanced Reactor Experimental Facilities (TAREF) was initiated with the aim of providing an overview of facilities suitable for carrying out the safety research considered necessary for gas-cooled reactors (GCRs) and sodium fast reactors (SFRs), with other reactor systems possibly being considered in a subsequent phase. The TAREF was thus created in 2008 with the following participating countries: Canada, the Czech Republic, Finland, France, Germany, Hungary, Italy, Japan, Korea and the United States. In a second stage, India provided valuable information on its experimental facilities related to SFR safety research. The study method adopted entailed first identifying high-priority safety issues that require research and then categorizing the available facilities in terms of their ability to address the safety issues. For each of the technical areas, the task members agreed on a set of safety issues requiring research and established a ranking with regard to safety relevance (high, medium, low) and the status of knowledge based on the following scale relative to full knowledge: high (100%-75%), medium (75 - 25%) and low (25-0%). Only the issues identified as being of high safety relevance and for which the state of knowledge is low or medium were included in the discussion, as these issues would likely warrant further study. For each of the safety issues, the TAREF members identified appropriate facilities, providing relevant information such as operating conditions (in- or out-of reactor), operating range, description of the test section, type of testing, instrumentation, current status and availability, and uniqueness. Based on the information collected, the task members assessed prospects and priorities

  4. Washingtoni varjatumad vestlused / Argo Ideon

    Index Scriptorium Estoniae

    Ideon, Argo, 1966-

    2007-01-01

    President Toomas Hendrik Ilvese kohtumistel USA presidendi George W. Bushi, kaitseminister Robert M. Gates'i ja juhtivate kongresmenidega olid kõne all viisavabadus, Eestisse NATO küberkeskuse rajamine ning ka suhted Venemaaga. Vabariigi President töövisiidil Ameerika Ühendriikides 25.-26.06.2007

  5. Endine patsiga poiss / Argo Ideon

    Index Scriptorium Estoniae

    Ideon, Argo, 1966-

    2007-01-01

    E-hääletuse süsteemi looja Tarvi Martens sai organisatsioonilt Junior Chamber International (Rahvusvaheline Noortekoda) auhinna. T. Martens ei luba, et lähiajal käivituksid Eestis uued, maailma vapustavad e-lahendused, vaid leiab, et inimesed võiksid rohkem kasutada juba olemasolevaid lahendusi. Eesmärk on, et Eesti oleks 2009. aastaks kõige turvalisema internetiga riik

  6. Reactor simulator development. Workshop material

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency (IAEA) has established a programme in nuclear reactor simulation computer programs to assist its Member States in education and training. The objective is to provide, for a variety of advanced reactor types, insight and practice in reactor operational characteristics and their response to perturbations and accident situations. To achieve this, the IAEA arranges for the supply or development of simulation programs and training material, sponsors training courses and workshops, and distributes documentation and computer programs. This publication consists of course material for workshops on development of such reactor simulators. Participants in the workshops are provided with instruction and practice in the development of reactor simulation computer codes using a model development system that assembles integrated codes from a selection of pre-programmed and tested sub-components. This provides insight and understanding into the construction and assumptions of the codes that model the design and operational characteristics of various power reactor systems. The main objective is to demonstrate simple nuclear reactor dynamics with hands-on simulation experience. Using one of the modular development systems, CASSIMtm , a simple point kinetic reactor model is developed, followed by a model that simulates the Xenon/Iodine concentration on changes in reactor power. Lastly, an absorber and adjuster control rod, and a liquid zone model are developed to control reactivity. The built model is used to demonstrate reactor behavior in sub-critical, critical and supercritical states, and to observe the impact of malfunctions of various reactivity control mechanisms on reactor dynamics. Using a PHWR simulator, participants practice typical procedures for a reactor startup and approach to criticality. This workshop material consists of an introduction to systems used for developing reactor simulators, an overview of the dynamic simulation

  7. Reactor water spontaneous circulation structure in reactor pressure vessel

    International Nuclear Information System (INIS)

    The gap between the inner wall of a reactor pressure vessel of a BWR type reactor and a reactor core shroud forms a down comer in which reactor water flows downwardly. A feedwater jacket to which feedwater at low temperature is supplied is disposed at the outer circumference of the pressure vessel just below a gas/water separator. The reactor water at the outer circumferential portion just below the air/water separator is cooled by the feedwater jacket, and the feedwater after cooling is supplied to the feedwater entrance disposed below the feedwater jacket by way of a feedwater introduction line to supply the feedwater to the lower portion of the down comer. This can cool the reactor water in the down comer to increase the reactor water density in the down comer thereby forming strong downward flows and promote the recycling of the reactor water as a whole. With such procedures, the reactor water can be recycled stably only by the difference of the specific gravity of the reactor water without using an internal pump. In addition, the increase of the height of the pressure vessel can be suppressed. (I.N.)

  8. Safety review, assessment and inspection on research reactors, experimental reactors, nuclear heating reactors and critical facilities

    International Nuclear Information System (INIS)

    In 1998, the NNSA organized to complete the nuclear safety review on the test loop in-reactor operation of the High-flux Engineering Experimental Reactor (HFEER) and the re-operation of the China Pulsed Reactor and the Uranium-water Criticality Facility. The NNSA conducted the nuclear safety review on the CP application of the China Experimental Fast Reactor (CEFR) and the siting of China Advanced Research Reactor (CARR), and carried out the construction supervision on HTR-10, and dealt with the event about the technological tube breakage of HWRR and other events

  9. Compact fusion reactors

    CERN Document Server

    CERN. Geneva

    2015-01-01

    Fusion research is currently to a large extent focused on tokamak (ITER) and inertial confinement (NIF) research. In addition to these large international or national efforts there are private companies performing fusion research using much smaller devices than ITER or NIF. The attempt to achieve fusion energy production through relatively small and compact devices compared to tokamaks decreases the costs and building time of the reactors and this has allowed some private companies to enter the field, like EMC2, General Fusion, Helion Energy, Lawrenceville Plasma Physics and Lockheed Martin. Some of these companies are trying to demonstrate net energy production within the next few years. If they are successful their next step is to attempt to commercialize their technology. In this presentation an overview of compact fusion reactor concepts is given.

  10. Elk River Reactor dismantling

    International Nuclear Information System (INIS)

    The dismantling program was carried out in three overlapping phases: the planning phase which included the preliminary planning and selection of the dismantling approach, the dismantling phase which included all work performed to remove the reactor facility and restore the site to its pre-reactor condition, and the closeout phase which included the final site survey and efforts necessary to terminate the AEC license and contract. Of particular interest was the use of a remotely operated plasma cutting torch to section the pressure vessel internals, the pressure vessel and the outer thermal shield, the use of explosives in removal of the biological shield and the method of establishment of the criteria for material disposal

  11. REACTOR MODERATOR STRUCTURE

    Science.gov (United States)

    Greenstreet, B.L.

    1963-12-31

    A system for maintaining the alignment of moderator block structures in reactors is presented. Integral restraining grids are placed between each layer of blocks in the moderator structure, at the top of the uppermost layer, and at the bottom of the lowermost layer. Slots are provided in the top and bottom surfaces of the moderator blocks so as to provide a keying action with the grids. The grids are maintained in alignment by vertical guiding members disposed about their peripheries. (AEC)

  12. Fusion Reactor Materials

    International Nuclear Information System (INIS)

    SCK-CEN's programme on fusion reactor materials includes studies (1) to investigate fracture mechanics of neutron-irradiated beryllium; (2) to describe the helium behaviour in irradiated beryllium at atomic scale; (3) to define the kinetics of beryllium reacting with air or steam; (3) to perform a feasibility study for the testing of integrated blanket modules under neutron irradiation. Progress and achievements in 1997 are reported

  13. Decommissioning of research reactors

    International Nuclear Information System (INIS)

    Research reactors of WWR-S type were built in countries under Soviet influence in '60, last century and consequently reached their service life. Decommissioning implies removal of all radioactive components, processing, conditioning and final disposal in full safety of all sources on site of radiological pollution. The WWR-S reactor at Bucuresti-Magurele was put into function in 1957 and operated until 1997 when it was stopped and put into conservation in view of decommissioning. Presented are three decommissioning variants: 1. Reactor shut-down for a long period (30-50 years) what would entail a substantial decrease of contamination with lower costs in dismantling, mechanical, chemical and physical processing followed by final disposal of the radioactive wastes. The drawback of this solution is the life prolongation of a non-productive nuclear unit requiring funds for personnel, control, maintenance, etc; 2. Decommissioning in a single stage what implies large funds for a immediate investment; 3. Extending the operation on a series of stages rather phased in time to allow a more convenient flow of funds and also to gather technical solutions, better than the present ones. This latter option seems to be optimal for the case of the WWR-S Research at Bucharest-Magurele Reactor. Equipment and technologies should be developed in order to ensure the technical background of the first operations of decommissioning: equipment for scarification, dismantling, dismemberment in a highly radioactive environment; cutting-to-pieces and disassembling technologies; decontamination modern technologies. Concomitantly, nuclear safety and quality assurance regulations and programmes, specific to decommissioning projects should be implemented, as well as a modern, coherent and reliable system of data acquisition, recording and storing. Also the impact of decommissioning must be thoroughly evaluated. The national team of specialists will be assisted by IAEA experts to ensure the

  14. Nuclear reactor container

    International Nuclear Information System (INIS)

    Upon reactor accident, hydrogen and oxygen are generated by water-zirconium reaction and radiolysis of water, which are accumulated in the reactor. If the concentration of hydrogen and oxygen exceeds a burning limit, there is a possibility of hydrogen burning to cause a danger of deteriorating the integrity of the reactor container and the equipments therein. The limit for the occurrence of the detonation is determined by a relationship between the scale of a detonation cell and the size of the container, and if the scale is greater than the container, the detonation does not occur. The scale of the cell is determined by a gas combustion rate and, if the combustion reaction is suppressed, detonation does not occur even in a large container. Then, an appropriate diluent is added to increase heat capacity of a gas mixture to thereby suppress the temperature elevation of the gas. Incombustible gases having a great heat capacity are preferred for the diluent, and CO2 is used. As the concentration of the CO2 gas to be added is increased, the detonation cell is made greater. Thus, occurrence of detonation due to combustion of the accumulated hydrogen can be prevented. (N.H.)

  15. Towards nuclear fusion reactors

    International Nuclear Information System (INIS)

    In the middle of 21st century, the population on the earth is expected to double, and the energy that mankind consumes to triple. The nuclear fusion which is said the ultimate energy source for mankind is expected to solve this energy problem. As for fusion reactors, fuel materials exist inexhaustibly, distributing evenly, they have high safety in principle, the product of burning is harmless nonradioactive substance that does not require the treatment and disposal, and the attenuation of induced radioactivity due to neutrons is quick and the effect to global environment is little. The basic plan of second stage nuclear fusion research and development was decided in 1975, aiming at attaining the critical plasma condition. JT-60 has attained it in 1987. The project of international thermonuclear fusion experimental reactor (ITER) was started, and the conceptual design was carried out. Under such background, the third stage basic plan was decided in 1992, and its objective is self ignition condition, long time burning and the basis of the reactor engineering technology. The engineering design of the ITER is investigated. (K.I.)

  16. High temperature gas reactor

    International Nuclear Information System (INIS)

    The present invention provides a reflector block structure of a high temperature gas reactor in which graphite blocks are not failed even a containing cylinder loaded to a fuel exchanger collides against to secured reflectors upon loading and withdrawing fuel constitutional elements. Namely, a protection plate made of a metal material such as stainless steel is covered on the secured reflector blocks disposed to the upper most step among secured graphite reflector blocks constituting the reactor core. In addition, positioning guide grooves are formed on the protection plate for guiding the containing cylinder loaded to the fuel exchanger to the column of the reactor core constitutional elements. With such a constitution, even if the containing cylinder of fuel exchanger is hoisted down and collided against the inner circumferential edge of the secured reflector blocks due to deviation of the position and the direction upon exchange of fuels, the reflector blocks are not failed since the above-mentioned portion is covered with the metal protection plate. In addition, the positioning guide grooves lead the fuel exchanger to a predetermined column correctly. (I.S.)

  17. BWR type reactor

    International Nuclear Information System (INIS)

    In a coolant circulation in BWR type reactors, since the mixed stream of steam fluid undergoes a great resistance, the pressure loss due to the flow rate distribution when the coolants flow from the upper plenum into the stand pipe is increased upon passing stand pipe. Also in the spontaneous recycling reactor, pressure loss is still left upon passing the swirling blade of a gas-liquid separator. In view of the above, a plurality of vertical members each having a lower end opened to a gas-liquid two phase boundary and an upper end directly suspended from a steam dryer to the gas-liquid separator. The liquid droplets from the 2-phase boundary heated in the reactor core and formed into a mixed gas-liquid 2-phase stream is directed in the vertical direction accompanied with the steam. The liquid droplets spontaneously fallen by gravity from greater ones successively and the droplets in the steam abutted against the vertical member are fallen as a liquid membrane. Thus, the gas-liquid separation is conducted, the dry steam is directly flown into the steam dryer, thereby capable of providing a gas-liquid separator having gas-liquid separation performance with lower loss than usual. (N.H.)

  18. Licensed operating reactors

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission's monthly LICENSED OPERATING REACTORS Status Summary Report provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management, from the Headquarters Staff of NRC's Office of Inspection and Enforcement, from NRC's Regional Offices, and from utilities. Since all of the data concerning operation of the units is provided by the utility operators less than two weeks after the end of the month, necessary corrections to published information are shown on the ERRATA page. This report is divided into three sections: the first contains monthly highlights and statistics for commercial operating units, and errata from previously reported data; the second is a compilation of detailed information on each unit, provided by NRC Regional Offices, IE Headquarters and the Utilities; and the third section is an appendix for miscellaneous information such as spent fuel storage capability, reactor years of experience and non-power reactors in the United States

  19. Fusion reactor safety

    International Nuclear Information System (INIS)

    Nuclear fusion could soon become a viable energy source. Work in plasma physics, fusion technology and fusion safety is progressing rapidly in a number of Member States and international collaboration continues on work aiming at the demonstration of fusion power generation. Safety of fusion reactors and technological and radiological aspects of waste management are important aspects in the development and design of fusion machines. In order to provide an international forum to review and discuss the status and the progress made since 1983 in programmes related to operational safety aspects of fusion reactors, their waste management and decommissioning concepts, the IAEA had organized the Technical Committee on ''Fusion Reactor Safety'' in Culham, 3-7 November 1986. All presentations of this meeting were divided into four sessions: 1. Statements on National-International Fusion Safety Programmes (5 papers); 2. Operation and System Safety (15 papers); 3. Waste Management and Decommissioning (5 papers); 4. Environmental Impacts (6 papers). A separate abstract was prepared for each of these 31 papers. Refs, figs, tabs

  20. Licensed operating reactors

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission's monthly LICENSED OPERATING REACTORS Status Summary Report provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management, from the Headquarters Staff of NRC's Office of Inspection and Enforcement, from NRC's Regional Offices, and from utilities. Since all of the data concerning operation of the units are provided by the utility operators less than two weeks after the end of the month, necessary corrections to published information are shown on the ERRATA page. This report is divided into three sections: the first contains monthly highlights and statistics for commercial operating units, and errata from previously reported data; the second is a compilation of detailed information on each unit, provided by NRC Regional Offices, IE Headquarters and the Utilities; and the third section is an appendix for miscellaneous information such as spent fuel storage capability, reactor years of experience and non-power reactors in the United States

  1. OECD Halden Reactor Project

    International Nuclear Information System (INIS)

    The OECD Halden Reactor project is an agreement between OECD member countries. It was first signed in 1958 and since then regularly renewed every third year. The activities at the Project is centred around the Halden heavy water rector, the HBWR. The reseach programme comprizes studies of fuel performance under various operating conditions, and the application of computers for process control. The HBWR is equipped for exposing fuel rods to temperatures and pressures, and at heat ratings met in modern BWR's and PWR's. A range of in-core instruments are available, permitting detailed measurements of the reactions of the fuel, including mechanical deformations, thermal behaviour, fission gas release, and corrosion. In the area of computer application, the studies of the communication between operator and process, and the surveillance and control of the reactor core, are of particular interst for reactor operation. 1988 represents the 30th year since the Project was started, and this publication is produced to mark this event. It gives and account of the activities and achievements of the Project through the years 1958-1988

  2. Nuclear research reactors in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Cota, Anna Paula Leite; Mesquita, Amir Zacarias, E-mail: aplc@cdtn.b, E-mail: amir@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The rising concerns about global warming and energy security have spurred a revival of interest in nuclear energy, giving birth to a 'nuclear power renaissance' in several countries in the world. Particularly in Brazil, in the recent years, the nuclear power renaissance can be seen in the actions that comprise its nuclear program, summarily the increase of the investments in nuclear research institutes and the government target to design and build the Brazilian Multipurpose research Reactor (BMR). In the last 50 years, Brazilian research reactors have been used for training, for producing radioisotopes to meet demands in industry and nuclear medicine, for miscellaneous irradiation services and for academic research. Moreover, the research reactors are used as laboratories to develop technologies in power reactors, which are evaluated today at around 450 worldwide. In this application, those reactors become more viable in relation to power reactors by the lowest cost, by the operation at low temperatures and, furthermore, by lower demand for nuclear fuel. In Brazil, four research reactors were installed: the IEA-R1 and the MB-01 reactors, both at the Instituto de Pesquisas Energeticas Nucleares (IPEN, Sao Paulo); the Argonauta, at the Instituto de Engenharia Nuclear (IEN, Rio de Janeiro) and the IPR-R1 TRIGA reactor, at the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN, Belo Horizonte). The present paper intends to enumerate the characteristics of these reactors, their utilization and current academic research. Therefore, through this paper, we intend to collaborate on the BMR project. (author)

  3. Chernobyl reactor transient simulation study

    International Nuclear Information System (INIS)

    This paper deals with the Chernobyl nuclear power station transient simulation study. The Chernobyl (RBMK) reactor is a graphite moderated pressure tube type reactor. It is cooled by circulating light water that boils in the upper parts of vertical pressure tubes to produce steam. At equilibrium fuel irradiation, the RBMK reactor has a positive void reactivity coefficient. However, the fuel temperature coefficient is negative and the net effect of a power change depends upon the power level. Under normal operating conditions the net effect (power coefficient) is negative at full power and becomes positive under certain transient conditions. A series of dynamic performance transient analysis for RBMK reactor, pressurized water reactor (PWR) and fast breeder reactor (FBR) have been performed using digital simulator codes, the purpose of this transient study is to show that an accident of Chernobyl's severity does not occur in PWR or FBR nuclear power reactors. This appears from the study of the inherent, stability of RBMK, PWR and FBR under certain transient conditions. This inherent stability is related to the effect of the feed back reactivity. The power distribution stability in the graphite RBMK reactor is difficult to maintain throughout its entire life, so the reactor has an inherent instability. PWR has larger negative temperature coefficient of reactivity, therefore, the PWR by itself has a large amount of natural stability, so PWR is inherently safe. FBR has positive sodium expansion coefficient, therefore it has insufficient stability it has been concluded that PWR has safe operation than FBR and RBMK reactors

  4. United States Domestic Research Reactor Infrastructure TRIGA Reactor Fuel Support

    International Nuclear Information System (INIS)

    The purpose of this technical paper is to provide status of the United State domestic Research Reactor Infrastructure (RRI) Program at the Idaho National Laboratory. This paper states the purpose of the program, lists the universities operating TRIGA reactors that are supported by the program, identifies anticipated fresh fuel needs for the reactor facilities, discusses spent fuel activities associated with the program, and addresses successes and planned activities for the program. (author)

  5. Thermionic Reactor Design Studies

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred

    1994-06-01

    During the 1960's and early 70's the author performed extensive design studies, analyses, and tests aimed at thermionic reactor concepts that differed significantly from those pursued by other investigators. Those studies, like most others under Atomic Energy Commission (AEC and DOE) and the National Aeronautics and Space Administration (NASA) sponsorship, were terminated in the early 1970's. Some of this work was previously published, but much of it was never made available in the open literature. U.S. interest in thermionic reactors resumed in the early 80's, and was greatly intensified by reports about Soviet ground and flight tests in the late 80's. This recent interest resulted in renewed U.S. thermionic reactor development programs, primarily under Department of Defense (DOD) and Department of Energy (DOE) sponsorship. Since most current investigators have not had an opportunity to study all of the author's previous work, a review of the highlights of that work may be of value to them. The present paper describes some of the author's conceptual designs and their rationale, and the special analytical techniques developed to analyze their performance. The basic designs, first published in 1963, are based on single-cell converters, either double-ended diodes extending over the full height of the reactor core or single-ended diodes extending over half the core height. In that respect they are similar to the thermionic fuel elements employed in the Topaz-2 reactor subsequently developed in the Soviet Union, copies of which were recently imported by the U.S. As in the Topaz-2 case, electrically heated steady-state performance tests of the converters are possible before fueling. Where the author's concepts differed from the later Topaz-2 design was in the relative location of the emitter and the collector. Placing the fueled emitter on the outside of the cylindrical diodes permits much higher axial conductances to reduce ohmic

  6. Applications of Research Reactors

    International Nuclear Information System (INIS)

    One of the IAEA's statutory objectives is to 'seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world.' One way this objective is achieved is through the publication of a range of technical series. Two of these are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III.A.6 of the IAEA Statute, the safety standards establish 'standards of safety for protection of health and minimization of danger to life and property'. The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are written primarily in a regulatory style, and are binding on the IAEA for its own programmes. The principal users are the regulatory bodies in Member States and other national authorities. The IAEA Nuclear Energy Series comprises reports designed to encourage and assist R and D on, and application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia, and government officials, among others. This information is presented in guides, reports on technology status and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The IAEA Nuclear Energy Series complements the IAEA Safety Standards Series. The purpose of the earlier publication, The Application of Research Reactors, IAEA-TECDOC-1234, was to present descriptions of the typical forms of research reactor use. The necessary criteria to enable an application to be performed were outlined for each one, and, in many cases, the minimum as well as the desirable requirements were given. This revision of the publication over a decade later maintains the original purpose and now specifically takes into account the changes in service requirements demanded by the relevant stakeholders. In particular, the significant improvements in

  7. Reactor technology: power conversion systems and reactor operation and maintenance

    International Nuclear Information System (INIS)

    The use of advanced fuels permits the use of coolants (organic, high pressure helium) that result in power conversion systems with good thermal efficiency and relatively low cost. Water coolant would significantly reduce thermal efficiency, while lithium and salt coolants, which have been proposed for DT reactors, will have comparable power conversion efficiencies, but will probably be significantly more expensive. Helium cooled blankets with direct gas turbine power conversion cycles can also be used with DT reactors, but activation problems will be more severe, and the portion of blanket power in the metallic structure will probably not be available for the direct cycle, because of temperature limitations. A very important potential advantage of advanced fuel reactors over DT fusion reactors is the possibility of easier blanket maintenance and reduced down time for replacement. If unexpected leaks occur, in most cases the leaking circuit can be shut off and a redundant cooling curcuit will take over the thermal load. With the D-He3 reactor, it appears practical to do this while the reactor is operating, as long as the leak is small enough not to shut down the reactor. Redundancy for Cat-D reactors has not been explored in detail, but appears feasible in principle. The idea of mobile units operating in the reactor chamber for service and maintenance of radioactive elements is explored

  8. Nuclear Reactor RA Safety Report, Vol. 4, Reactor

    International Nuclear Information System (INIS)

    RA research reactor is thermal heavy water moderated and cooled reactor. Metal uranium 2% enriched fuel elements were used at the beginning of its operation. Since 1976, 80% enriched uranium oxide dispersed in aluminium fuel elements were gradually introduced into the core and are the only ones presently used. Reactor core is cylindrical, having diameter 40 cm and 123 cm high. Reaktor core is made up of 82 fuel elements in aluminium channels, lattice is square, lattice pitch 13 cm. Reactor vessel is cylindrical made of 8 mm thick aluminium, inside diameter 140 cm and 5.5 m high surrounded with neutron reflector and biological shield. There is no containment, the reactor building is playing the shielding role. Three pumps enable circulation of heavy water in the primary cooling circuit. Degradation of heavy water is prevented by helium cover gas. Control rods with cadmium regulate the reactor operation. There are eleven absorption rods, seven are used for long term reactivity compensation, two for automatic power regulation and two for safety shutdown. Total anti reactivity of the rods amounts to 24%. RA reactor is equipped with a number of experimental channels, 45 vertical (9 in the core), 34 in the graphite reflector and two in the water biological shield; and six horizontal channels regularly distributed in the core. This volume include detailed description of systems and components of the RA reactor, reactor core parameters, thermal hydraulics of the core, fuel elements, fuel elements handling equipment, fuel management, and experimental devices

  9. The research reactor TRIGA Mainz

    International Nuclear Information System (INIS)

    Paper dwells upon the design and the operation of one of the German test reactors, namely, the TRIGA Mainz one (TRIGA: Training Research Isotope Production General Atomic). The TRIGA reactor is a pool test reactor the core of which contains a graphite reflector and is placed into 2 m diameter and 6.25 m height aluminum vessel. There are 75 fuel elements in the reactor core, and any of them contains about 36 g of 235U. The TRIGA reactors under the stable operation enjoy wide application to ensure tests and irradiation, namely: neutron activation analysis, radioisotope production, application of a neutron beam to ensure the physical, the chemical and the medical research efforts. Paper presents the reactor basic experimental program lines

  10. Spiral-shaped disinfection reactors

    KAUST Repository

    Ghaffour, Noreddine

    2015-08-20

    This disclosure includes disinfection reactors and processes for the disinfection of water. Some disinfection reactors include a body that defines an inlet, an outlet, and a spiral flow path between the inlet and the outlet, in which the body is configured to receive water and a disinfectant at the inlet such that the water is exposed to the disinfectant as the water flows through the spiral flow path. Also disclosed are processes for disinfecting water in such disinfection reactors.

  11. Industrializing the liquid metal reactor

    International Nuclear Information System (INIS)

    Commercial acceptance of the liquid metal reactor had its beginning with the Fermi reactor, over two decades ago. The pattern of industrialization since that time is discussed, contrasting domestic and foreign experience. The recent termination of the Clinch River reactor project marks a watershed in the U.S. approach towards commercialization. The increased emphasis on achieving cost competitive designs reflects an awareness that barriers to industrialization are institutional and financial, and not technological

  12. Acceptability of reactors in space

    Energy Technology Data Exchange (ETDEWEB)

    Buden, D.

    1981-04-01

    Reactors are the key to our future expansion into space. However, there has been some confusion in the public as to whether they are a safe and acceptable technology for use in space. The answer to these questions is explored. The US position is that when reactors are the preferred technical choice, that they can be used safely. In fact, it dies not appear that reactors add measurably to the risk associated with the Space Transportation System.

  13. Hydrogen Production in Fusion Reactors

    OpenAIRE

    Sudo, S.; Tomita, Y.; Yamaguchi, S.; Iiyoshi, A.; Momota, H.; Motojima, O.; Okamoto, M; Ohnishi, M.; Onozuka, M.; Uenosono, C.

    1993-01-01

    As one of methods of innovative energy production in fusion reactors without having a conventional turbine-type generator, an efficient use of radiation produced in a fusion reactor with utilizing semiconductor and supplying clean fuel in a form of hydrogen gas are studied. Taking the candidates of reactors such as a toroidal system and an open system for application of the new concepts, the expected efficiency and a concept of plant system are investigated.

  14. Fast reactor programme in India

    Indian Academy of Sciences (India)

    P Chellapandi; P R Vasudeva Rao; Prabhat Kumar

    2015-09-01

    Role of fast breeder reactor (FBR) in the Indian context has been discussed with appropriate justification. The FBR programme since 1985 till 2030 is highlighted focussing on the current status and future direction of fast breeder test reactor (FBTR), prototype fast breeder reactor (PFBR) and FBR-1 and 2. Design and technological challenges of PFBR and design and safety targets with means to achieve the same are the major highlights of this paper.

  15. Turning points in reactor design

    International Nuclear Information System (INIS)

    This article provides some historical aspects on nuclear reactor design, beginning with PWR development for Naval Propulsion and the first commercial application at Yankee Rowe. Five turning points in reactor design and some safety problems associated with them are reviewed: (1) stability of Dresden-1, (2) ECCS, (3) PRA, (4) TMI-2, and (5) advanced passive LWR designs. While the emphasis is on the thermal-hydraulic aspects, the discussion is also about reactor systems

  16. Optimal control of nuclear reactors

    International Nuclear Information System (INIS)

    The modern control theory is applied to the design of control systems for experimental nuclear reactors that do not belong to power reactors, the component forms of optimal control systems for nuclear reactors are demonstrated. The adoption of output quadratic integral criterion and incomplete state feedback technique can make these systems both efficient and economical. Moreover, approximate handling methods are given so as to simplify the calculations in design. In addition, the adoptable reference values of parameters are given in the illustration

  17. Turning points in reactor design

    Energy Technology Data Exchange (ETDEWEB)

    Beckjord, E.S.

    1995-09-01

    This article provides some historical aspects on nuclear reactor design, beginning with PWR development for Naval Propulsion and the first commercial application at Yankee Rowe. Five turning points in reactor design and some safety problems associated with them are reviewed: (1) stability of Dresden-1, (2) ECCS, (3) PRA, (4) TMI-2, and (5) advanced passive LWR designs. While the emphasis is on the thermal-hydraulic aspects, the discussion is also about reactor systems.

  18. Acceptability of reactors in space

    International Nuclear Information System (INIS)

    Reactors are the key to our future expansion into space. However, there has been some confusion in the public as to whether they are a safe and acceptable technology for use in space. The answer to these questions is explored. The US position is that when reactors are the preferred technical choice, that they can be used safely. In fact, it does not appear that reactors add measurably to the risk associated with the Space Transportation System

  19. Advanced Fission Reactor Program objectives

    International Nuclear Information System (INIS)

    The objective of an advanced fission reactor program should be to develop an economically attractive, safe, proliferation-resistant fission reactor. To achieve this objective, an aggressive and broad-based research and development program is needed. Preliminary work at Brookhaven National Laboratory shows that a reasonable goal for a research program would be a reactor combining as many as possible of the following features: (1) initial loading of uranium enriched to less than 15% uranium 235, (2) no handling of fuel for the full 30-year nominal core life, (3) inherent safety ensured by core physics, and (4) utilization of natural uranium at least 5 times as efficiently as light water reactors

  20. Reactor safety - an international task

    International Nuclear Information System (INIS)

    The dimensions and the significance of the task of ensuring reactor safety can be defined on the basis of experiences gained from Harrisburg and Chernobyl. The countries that use nuclear energy are tied together to a community by virtue of the risk they share. Therefore the GRS is working in close cooperation with the EC, OECD, IAEO and COMECON. This results in safety examinations of the Greifswald reactor, safety analyses of nuclear reactors in Germany, France and the USA and also considerations on the safety demands to be placed on new reactor concepts. (DG)

  1. Operating reactors licensing actions summary

    International Nuclear Information System (INIS)

    The operating reactors licensing actions summary is designed to provide the management of the Nuclear Regulatory Commission (NRC) with an overview of licensing actions dealing with operating power and nonpower reactors. These reports utilize data collected from the Division of Licensing in the Office of Nuclear Reactor Regulation and are prepared by the Office of Management and Program Analysis. This summary report is published primarily for internal NRC use in managing the operating reactors licensing actions program. Its content will change based on NRC management informational requirements

  2. Integrated modular water reactor: IMR

    International Nuclear Information System (INIS)

    The Mitsubishi Heavy Industries, Ltd. Has investigated on a concept on small scale reactor with economical efficiency comparable with large scale one. Aims of development on the integrated modular water reactor (IMR) of a small scale reactor plant concept consist in large construction cost reduction through adoption of technique specific to the small scale reactor and integrated production of plural units and in establishment of high safety target without reality in a large scale reactor to realize reduction of operation and maintenance costs by this reduction to simplification of operation and maintenance. Its concrete developmental targets are to make an integrated reactor with vessel size actually producible and the largest output, to remove feasibility of coolant loss accident (LOCA), to remove an accident with feasibility related to fuel fracture, to remove feasibility of nuclear reactor coolant to leak out from a storage vessel, to secure safety of plant without necessity of human and physical assistances from other plants at all on an accident, to make numbers of operators per unit output equal to those of large scale reactor, and to make working amounts at maintenance per unit output equal to large scale reactor by simplification of apparatus practice of rotation on main apparatus such as SG, and so on. Here were described on design concept and plan to realization. (G.K.)

  3. 3. Interindustry conference on reactor materials science

    International Nuclear Information System (INIS)

    This document contains abstracts on papers presented at the Third Interindustry Conference on Reactor Materials Science (Dimitrovgrad, 27-30 October 1992). The subject scope of the papers is a follows: fuel and fuel elements of power reactors; structural materials of fast breeder reactors and thermonuclear reactors; structural materials of WWER and RBMK type reactors; absorbers and moderators

  4. Helias reactor studies

    International Nuclear Information System (INIS)

    The Helias reactor is an upgraded version of the Wendelstein 7-X experiment. The magnetic field has 5 field periods and the main optimization principle is the reduction of the Pfirsch-Schlueter currents and the Shafranov shift, which has been verified by computations with the NEMEC and MFBE-codes. The modular coil system comprises 50 coils, which are constructed using NbTi-superconducting cables. The basic dimensions are: major radius 22 m, average plasma radius 1.8 m, magnetic field on axis 5 T, maximum field on the coils 10 T. Forces and stresses in the coil system have been investigated with the aid of the ANSYS code, which found maximum stress values of about 650 MPa in the coil casing. Helias configurations with 4 and 3 field periods have been constructed by starting from the 5-period case and by eliminating one or two periods while the shape of the coils is kept nearly invariant. In a first survey blanket concepts, developed for the DEMO tokamak, have been adapted to the Helias geometry, in particular, the solid breeder concept developed by FZK (Karlsruhe) has been extrapolated to the Helias geometry identifying the drawbacks and advantages of this concept. Furthermore, the liquid breeder concept using Li7-Pb83 and water-cooling is an interesting alternative for the Helias reactor. Maintenance of blanket and plasma facing components is possible through the portholes between modular coils. Numerical simulations of the start-up phase of the Helias reactor using the TOTAL-P code have confirmed the zero-dimensional modeling of the fusion plasma with the aid of empirical scaling laws. (author)

  5. Reactor coolant pump flywheel

    Science.gov (United States)

    Finegan, John Raymond; Kreke, Francis Joseph; Casamassa, John Joseph

    2013-11-26

    A flywheel for a pump, and in particular a flywheel having a number of high density segments for use in a nuclear reactor coolant pump. The flywheel includes an inner member and an outer member. A number of high density segments are provided between the inner and outer members. The high density segments may be formed from a tungsten based alloy. A preselected gap is provided between each of the number of high density segments. The gap accommodates thermal expansion of each of the number of segments and resists the hoop stress effect/keystoning of the segments.

  6. Licensed operating reactors

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission's monthly Licensed Operating Reactors Status Summary Report provides data on the operation of nuclear units as timely and accurately as possible. This information is collected by the Office of Information Resources Management, from the Headquarters Staff of NRC's Office of Inspection and Enforcement, from NRC's Regional Offices, and from utilities. Since all of the data concerning operation of the units is provided by the utility operators less than two weeks after the end of the month, necessary corrections to published information are shown on the errata page

  7. FUEL ASSAY REACTOR

    Science.gov (United States)

    Spinrad, B.I.; Sandmeier, H.A.; Martens, F.H.

    1962-12-25

    A reactor having maximum sensitivity to perturbations is described comprising a core consisting of a horizontally disposed, rectangular, annular fuel zone containing enriched uranium dioxide dispersed in graphite, the concentration of uranium dioxide increasing from the outside to the inside of the fuel zone, an internal reflector of graphite containing an axial test opening disposed within the fuel zone, an external graphite reflector, means for changing the neutron spectrum in the test opening, and means for measuring perturbations in the neutron flux caused by the introduction of different fuel elements into the test opening. (AEC)

  8. Shutting down two reactors

    International Nuclear Information System (INIS)

    Nuclear power will be phased out of the swedish energy system during the first decades of the next century. Commissioned by the swedish government, the National Energy Administration reports a study on the possibilities for, and consequences of, an earlier shut down (1994-1996) of two of the twelve swedish power reactors. Some of the questions studied are: How much will the electricity price raise ?; How will the electricity consumption be affected ?; What are the alternatives to nuclear power ?; What will the cost be ? and What will the environmental effects be ?. (L.E.)

  9. Measurement in nuclear reactors

    International Nuclear Information System (INIS)

    A nuclear reactor construction has a flux detector comprising a bundle of fibre optics each having a bead incorporating a substance which scintillates on being struck by neutrons or gamma radiations. The other ends of the fibre optics terminate at an image intensifier. The optical fibres may be of glass made from a mixture of silica, alkaline earth metal oxide, cerous oxide and alkali metal oxide. The beads may be incorporated in a disc forming a detector head, which is in a protective guide tube, through which an inert gas may be passed. (author)

  10. TRIGA reactor operating experience

    International Nuclear Information System (INIS)

    The Oregon State TRIGA Reactor (OSTR) has been in operation 3 years. Last August it was upgraded from 250 kW to 1000 kW. This was accomplished with little difficulty. During the 3 years of operation no major problems have been experienced. Most of the problems have been minor in nature and easily corrected. They came from lazy susan (dry bearing), Westronics Recorder (dead spots in the range), The Reg Rod Magnet Lead-in Circuit (a new type lead-in wire that does not require the lead-in cord to coil during rod withdrawal hss been delivered, much better than the original) and other small corrections

  11. Reactor system safety assurance

    International Nuclear Information System (INIS)

    The philosophy of reactor safety is that design should follow established and conservative engineering practices, there should be safety margins in all modes of plant operation, special systems should be provided for accidents, and safety systems should have redundant components. This philosophy provides ''defense in depth.'' Additionally, the safety of nuclear power plants relies on ''safety systems'' to assure acceptable response to design basis events. Operating experience has shown the need to study plant response to more frequent upset conditions and to account for the influence of operators and non-safety systems on overall performance. Defense in depth is being supplemented by risk and reliability assessment

  12. The Oklo reactors

    International Nuclear Information System (INIS)

    The Oklo reactors comprise up to nine 235-U depleted zones in an uranium ore in the Republic of Gabon in West Africa. The depletion in fissile U-235 has been proved to have caused by nuclear chain reactions. The study of the Oklo phenomenon indicates that very efficient retardation mechanisms may operate in nature - at least under special conditions. A closer study of these processes ought to be made to establish the limitations to their occurrence. The Oklo sandstone formation today would probably be considered unacceptable as a host rock for a repository. (EG)

  13. Licensed reactor nuclear safety criteria applicable to DOE reactors

    Energy Technology Data Exchange (ETDEWEB)

    1991-04-01

    The Department of Energy (DOE) Order DOE 5480.6, Safety of Department of Energy-Owned Nuclear Reactors, establishes reactor safety requirements to assure that reactors are sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that adequately protects health and safety and is in accordance with uniform standards, guides, and codes which are consistent with those applied to comparable licensed reactors. This document identifies nuclear safety criteria applied to NRC (Nuclear Regulatory Commission) licensed reactors. The titles of the chapters and sections of USNRC Regulatory Guide 1.70, Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants, Rev. 3, are used as the format for compiling the NRC criteria applied to the various areas of nuclear safety addressed in a safety analysis report for a nuclear reactor. In each section the criteria are compiled in four groups: (1) Code of Federal Regulations, (2) US NRC Regulatory Guides, SRP Branch Technical Positions and Appendices, (3) Codes and Standards, and (4) Supplemental Information. The degree of application of these criteria to a DOE-owned reactor, consistent with their application to comparable licensed reactors, must be determined by the DOE and DOE contractor.

  14. Licensed reactor nuclear safety criteria applicable to DOE reactors

    International Nuclear Information System (INIS)

    The Department of Energy (DOE) Order DOE 5480.6, Safety of Department of Energy-Owned Nuclear Reactors, establishes reactor safety requirements to assure that reactors are sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that adequately protects health and safety and is in accordance with uniform standards, guides, and codes which are consistent with those applied to comparable licensed reactors. This document identifies nuclear safety criteria applied to NRC [Nuclear Regulatory Commission] licensed reactors. The titles of the chapters and sections of USNRC Regulatory Guide 1.70, Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants, Rev. 3, are used as the format for compiling the NRC criteria applied to the various areas of nuclear safety addressed in a safety analysis report for a nuclear reactor. In each section the criteria are compiled in four groups: (1) Code of Federal Regulations, (2) US NRC Regulatory Guides, SRP Branch Technical Positions and Appendices, (3) Codes and Standards, and (4) Supplemental Information. The degree of application of these criteria to a DOE-owned reactor, consistent with their application to comparable licensed reactors, must be determined by the DOE and DOE contractor

  15. Virtual nuclear reactor for education of nuclear reactor physics

    International Nuclear Information System (INIS)

    As one of projects that were programmed in the cultivation program for human resources in nuclear engineering sponsored by the Ministry of Economy, Trade and Industry, the development of a virtual reactor for education of nuclear reactor physics started in 2007. The purpose of the virtual nuclear reactor is to make nuclear reactor physics easily understood with aid of visualization. In the first year of this project, the neutron slowing down process was visualized. The data needed for visualization are provided by Monte Carlo calculations; The flights of the respective neutrons generated by nuclear fissions are traced through a reactor core until they disappear by neutron absorption or slow down to a thermal energy. With this visualization and an attached supplement textbook, it is expected that the learners can learn more clearly the physical implication of neutron slowing process that is mathematically described by the Boltzmann neutron transport equation. (author)

  16. Reactor Physics Analysis Models for a CANDU Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hang Bok

    2007-10-15

    Canada deuterium uranium (CANDU) reactor physics analysis is typically performed in three steps. At first, macroscopic cross-sections of the reference lattice is produced by modeling the reference fuel channel. Secondly macroscopic cross-sections of reactivity devices in the reactor are generated. The macroscopic cross-sections of a reactivity device are calculated as incremental cross-sections by subtracting macroscopic cross-sections of a three-dimensional lattice without reactivity device from those of a three-dimensional lattice with a reactivity device. Using the macroscopic cross-sections of the reference lattice and incremental cross-sections of the reactivity devices, reactor physics calculations are performed. This report summarizes input data of typical CANDU reactor physics codes, which can be utilized for the future CANDU reactor physics analysis.

  17. Reactor system on barge

    International Nuclear Information System (INIS)

    Floating electrical power plants or power plant barges add new dimensions to utility planners and agencies in the world. Intrinsically safe and economical reactors (ISER) employ steel reactor pressure vessels, which significantly reduce the weight as compared with PIUS, and provide siting versatility including barge-mounted plants. In this paper, the outline of power plant barges and barge-mounted ISERs is described. Besides their mobility, power plant barges have the salient advantages such as short delivery time and better quality control due to the outfitting in shipyards. These power plant barges may be temporarily moored or permanently grounded in shallow water at the centers of industrial complexes or the suitable areas adjacent to them, and satisfy the increasing needs for electric power. A cost-effective and technically perfect barge positioning system should be designed to meet the specific requirement for the location and its condition. Offshore siting away from coast may be applicable only to large plants of 1,000 MWe or more, and inshore siting and coastal or river siting are considered for an ISER-200 barge-mounted plant. The system of a barge-mounted ISER plant is discussed in the case of a floating type and the type on a seismic base isolator. (Kako, I.)

  18. Tokamak experimental power reactor

    International Nuclear Information System (INIS)

    A tokamak experimental power reactor has been designed that is capable of producing net electric power over a wide range of possible operating conditions. A net production of 81 MW of electricity is expected from the design reference conditions that assume a value of 0.07 for beta-toroidal, a maximum toroidal magnetic field of 9 T and a thermal conversion efficiency of 30%. Impurity control is achieved through the use of a low-Z first wall coating. This approach allows a burn time of 60 seconds without the incorporation of a divertor. The system is cooled by a dual pressurized water/steam system that could potentially provide thermal efficiencies as high as 39%. The first surface facing the plasma is a low-Z coated water cooled panel that is attached to a 20 cm thick blanket module. The vacuum boundary is removed a total of 22 cm from the plasma, thereby minimizing the amount of radiation damage in this vital component. Consideration is given in the design to the possible use of the EPR as a materials test reactor. It is estimated that the total system could be built for less than 550 million dollars

  19. The EPR reactor NDE

    International Nuclear Information System (INIS)

    In May 2006, Electricite de France decided to launch the building of the first EPRR Reactor on the Flamanville site in Normandy. The 'Flamanville 3' EPR unit is the first one to be subjected to the French Ministerial Orders of the 10 November 1999 and of the 13 December 2005 from the design phase. According to these orders, the non destructive examination (NDE) planned for the in service inspection (ISI) and for the pre service inspection (PSI) must be operational with a compulsory formal qualification. The PSI is a complete inspection of the main primary and secondary systems. The PSI's objective is to perform before the first core loading all the NDE planned for the future ISI in the same conditions, in order to have a reliable reference for the detection or for the evaluation of the possible damages during the ISI. The 'Flamanville 3' PSI is planned to start end 2010. The program consists of the development and the qualification of the NDE compatible with this new generation reactor's challenges. The paper is about: - the main EPR's objectives and the technological evolutions, - the main component modifications (which have an impact on the NDE), - the place of ISI in the general safety demonstration, - the main inspection objectives, - the NDE qualification process, - the approach to set up the ISI program, - the ISI program. (authors)

  20. Status of Japanese university reactors

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, Yoshiaki [Research Reactor Institute, Kyoto Univ., Kumatori, Osaka (Japan)

    1999-08-01

    Status of Japanese university reactors, their role and value in research and education, and the spent fuel problem are presented. Some of the reactors are now faced by severe difficulties in continuing their operation services. The point of measures to solve the difficulties is suggested. (author)