Sample records for argentine reactor ra-2

  1. Reactors

    CERN Document Server

    International Electrotechnical Commission. Geneva


    This standard applies to the following types of reactors: shunt reactors, current-limiting reactors including neutral-earthing reactors, damping reactors, tuning (filter) reactors, earthing transformers (neutral couplers), arc-suppression reactors, smoothing reactors, with the exception of the following reactors: small reactors with a rating generally less than 2 kvar single-phase and 10 kvar three-phase, reactors for special purposes such as high-frequency line traps or reactors mounted on rolling stock.

  2. Argentine tango in Parkinson disease. (United States)


    This article reports on a meta-analysis of 13 studies of the effects of Argentine tango (AT) as a music-based movement therapy for people with Parkinson's disease (PD). Nine studies involved randomised controlled trials.


    Institute of Scientific and Technical Information of China (English)

    WU An-hua; TIE Xin-xin; WANG Yun-jie; YANG Guo-rui


    Objective: To investigate the expression of IL-13Ra2 gene in brain tumors. Methods: Seventy-nine human brain tumors were obtained from the department of Neurosurgery of China Medical University. Human IL-13Ra2 expression was evaluated by reverse transcriptase polymerase chain reaction and immunohistochemical analysis. Results: IL-13Ra2 gene was highly expressed in glioblastoma, medulloblastoma, malignant meningioma and benign meningioma. Conclusion:Human IL-13Ra2 gene is expressed in brain tumors in addition to gliomas, and our result indicates that the IL-13Ra2 gene promoter based gene therapy method can be used to treat brain tumors in addition to gliomas. Further studies involving larger numbers of samples are necessary to fully understand the expression profile of IL-13Ra2 gene in the brain tumors.

  4. Ionizable (Thia)calix[4]crowns as Highly Selective 226Ra2+ Ionophores

    NARCIS (Netherlands)

    Leeuwen, van Fijs W.B.; Beijleveld, Hans; Miermans, Cornelis J.H.; Huskens, Jurriaan; Verboom, Willem; Reinhoudt, David N.


    The 226Ra2+ selectivity of the ionizable (thia)calix[4]crowns 1-4 was determined in the presence of a large excess of the most common alkali and alkaline earth cations. Selective 226Ra2+ (2.9 × 10-8 M) extraction occurs even at extremely high Mn+/226Ra2+ ratios of 3.5 × 107 [Mn+ = Na+, K+, Rb+, Cs+,

  5. Data of evolutionary structure change: 1E1RA-2HLDT [Confc[Archive

    Lifescience Database Archive (English)


  6. Carlos Mayo and Argentine historiography

    Directory of Open Access Journals (Sweden)

    Sara E. Mata


    Full Text Available The work of Carlos Mayo is distinguished by its originality and academic excellence. Our goal has been to briefly address their valuable contributions to the Argentine historiography, particularly that relating to the agricultural history of the Río de la Plata

  7. Contemporary Argentine Cinema during Neoliberalism (United States)

    Rocha, Carolina


    In this article I analyze contemporary Argentine cinematic production assessing the impact of Law 24,377 that was implemented in 1995 and that provided much-needed funds for national productions. By looking at film production and consumption, the emergence of young filmmakers and the performance of both commercial films and those belonging to the…

  8. Predicting Argentine Jet Fuel Prices (United States)


    economics, engineering, and the social and biological sciences (Kutner, 2005:2), but successful application of this method requires not only a deep...situations that affected the country. This crisis had politic, economic and social implications. Five presidents governed in a two month period. The...Scheimberg Sebastian. “Comentario al trabajo de German Coloma: Analisys of the behavior of the Argentine fuel market”. Political Economy Asociation

  9. Selective removal of 226Ra2+ from gas-field-produced waters

    NARCIS (Netherlands)

    Leeuwen, van Fijs W.B.; Miermans, Cornelis J.H.; Beijleveld, Hans; Tomasberger, Tanja; Davis, Jeffery T.; Verboom, Willem; Reinhoudt, David N.


    The 226Ra2+ selectivity of both the self-assembled (iso)guanosine-based systems and ionizable thiacalix[4]crown dicarboxylic acids was determined in gas-field-produced water and a metal ion-containing model solution (simulant). Seven gas-field-produced water samples have been analyzed. From a sample

  10. INVAP's Research Reactor Designs

    Directory of Open Access Journals (Sweden)

    Eduardo Villarino


    Full Text Available INVAP, an Argentine company founded more than three decades ago, is today recognized as one of the leaders within the research reactor industry. INVAP has participated in several projects covering a wide range of facilities, designed in accordance with the requirements of our different clients. For complying with these requirements, INVAP developed special skills and capabilities to deal with different fuel assemblies, different core cooling systems, and different reactor layouts. This paper summarizes the general features and utilization of several INVAP research reactor designs, from subcritical and critical assemblies to high-power reactors.

  11. Reactor (United States)

    Evans, Robert M.


    1. A neutronic reactor having a moderator, coolant tubes traversing the moderator from an inlet end to an outlet end, bodies of material fissionable by neutrons of thermal energy disposed within the coolant tubes, and means for circulating water through said coolant tubes characterized by the improved construction wherein the coolant tubes are constructed of aluminum having an outer diameter of 1.729 inches and a wall thickness of 0.059 inch, and the means for circulating a liquid coolant through the tubes includes a source of water at a pressure of approximately 350 pounds per square inch connected to the inlet end of the tubes, and said construction including a pressure reducing orifice disposed at the inlet ends of the tubes reducing the pressure of the water by approximately 150 pounds per square inch.

  12. The worldwide expansion of the Argentine ant

    DEFF Research Database (Denmark)

    Vogel, Valerie; Pedersen, Jes Søe; Giraud, Tatiana;


    ) and secondary introductions (from sites with established invasive supercolonies) were important in the global expansion of the Argentine ant. In combination with the similar social organization of colonies in the native and introduced range, this indicates that invasiveness did not evolve recently as a unique...

  13. IL-13Ra2- and glioma stem cell-pulsed dendritic cells induce glioma cell death in vitro

    Institute of Scientific and Technical Information of China (English)

    Ying Wang; Ruifan Xie; Hongquan Niu; Ting Lei


    Objective Gliomas are the most common malignant tumors in the central nervous system. Despite mul-tiple therapies including surgery, chemotherapy, and radiotherapy, the prognosis of patients remains poor. Immunotherapy is an alternative method of treating glioma, and the use of dendritic cel vaccines is one of the promising treatment options. However, there is no specific tumor cel antigen that can trigger dendritic cel s (DCs). IL-13Ra2 is a specific antigen expressed in glioma cel s; in the current study, we have at-tempted to explore whether IL-13Ra2 could be the antigen that triggers DCs and to envisage its application as potential therapy for glioma. Methods The expression of IL-13Ra2 was detected in U251 glioma cel lines and primary glioma tissues using dif erent methods. DCs from human blood were isolated and pulsed with recombinant IL-13Ra2, fol-lowing which the cytotoxicity of these DCs on glioma cel s was detected and analyzed. Results About 55.9% human glioma tissue cel s expressed IL-13Ra2, while normal brain tissue cel s did not show any expression. DC vaccines loaded with IL-13Ra2, glioma cel antigen, and brain tumor stem cel (BTSC) antigen could significantly stimulate the proliferation of T lymphocytes and induce cel death in the glioma tissue. Compared to other groups, DC vaccines loaded with BTSC antigen showed the strongest ability to activate cytotoxic T lymphocytes (CTLs), while the glioma cel antigen group showed no significant dif erence. Conclusion IL-13Ra2, which is expressed in gliomas and by glioma stem cel s, as wel as IL-13Ra2 could prove to be potential antigens for DC vaccine-based immunotherapy.

  14. 75 FR 53731 - Culturally Significant Objects Imported for Exhibition Determinations: “Contemporary Argentine... (United States)


    ... for Exhibition Determinations: ``Contemporary Argentine Masterworks'' SUMMARY: Notice is hereby given... hereby determine that the objects to be included in the exhibition ``Contemporary Argentine...

  15. Argentine hemorrhagic fever: a primate model. (United States)

    Weissenbacher, M C; Calello, M A; Colillas, O J; Rondinone, S N; Frigerio, M J


    Experimental Junin virus infection of a New World primate, Callithrix jacchus, was evaluated. The virus produced anorexia, loss of weight, thrombocytopenia, leukopenia, and hemorrhagic and neurological symptoms and terminated in death. Virus was recovered from urine, blood samples and all tissues taken at autopsy. These preliminary observations show that several aspects of the experimental disease in C. jacchus are quite similar to severe natural Argentine hemorrhagic fever of man.

  16. Exploration of Possible Astroblemes in the Argentine Puna (United States)

    Acevedo, R. D.; Alonso, R.; Rocca, M.; Klajnik, K.; Tálamo, E.


    Potential three new astrobleme sites have been detected by remote sensors and checked in situ in Argentine Puna: an elevated plateau that it has remained stable and invariable across long geological periods.

  17. Framing crime: moral panic in Argentine newspapers

    Directory of Open Access Journals (Sweden)

    Natalia ARUGUETE


    Full Text Available Carolina Píparo was shot a few minutes after withdrawing cash from a bank branch. This case outraged the public opinion because she was eight months pregnant at the moment of the assault. She had to undergo a caesarean section and her baby only survived one week. Through an exploratory and inductive research we will analyze how the Argentine newspapers presented the case. We aim at elaborating a content analysis code book that can be validated in future similar researches on the subject. We apply the Framing theory in order to detect the frames used in the news coverage and to observe if they are compatible with the idea of «moral panic» proposed by Stanley Cohen.

  18. Pheromone disruption of Argentine ant trail integrity (United States)

    Suckling, D.M.; Peck, R.W.; Manning, L.M.; Stringer, L.D.; Cappadonna, J.; El-Sayed, A. M.


    Disruption of Argentine ant trail following and reduced ability to forage (measured by bait location success) was achieved after presentation of an oversupply of trail pheromone, (Z)-9-hexadecenal. Experiments tested single pheromone point sources and dispersion of a formulation in small field plots. Ant walking behavior was recorded and digitized by using video tracking, before and after presentation of trail pheromone. Ants showed changes in three parameters within seconds of treatment: (1) Ants on trails normally showed a unimodal frequency distribution of walking track angles, but this pattern disappeared after presentation of the trail pheromone; (2) ants showed initial high trail integrity on a range of untreated substrates from painted walls to wooden or concrete floors, but this was significantly reduced following presentation of a point source of pheromone; (3) the number of ants in the pheromone-treated area increased over time, as recruitment apparently exceeded departures. To test trail disruption in small outdoor plots, the trail pheromone was formulated with carnuba wax-coated quartz laboratory sand (1 g quartz sand/0.2 g wax/1 mg pheromone). The pheromone formulation, with a half-life of 30 h, was applied by rotary spreader at four rates (0, 2.5, 7.5, and 25 mg pheromone/m2) to 1- and 4-m2 plots in Volcanoes National Park, Hawaii. Ant counts at bait cards in treated plots were significantly reduced compared to controls on the day of treatment, and there was a significant reduction in ant foraging for 2 days. These results show that trail pheromone disruption of Argentine ants is possible, but a much more durable formulation is needed before nest-level impacts can be expected. ?? 2008 Springer Science+Business Media, LLC.

  19. The Mindful Attention Awareness Scale (MAAS) in an Argentine Population (United States)

    Montes, Silvana Andrea; Ledesma, Rubén Daniel; García, Natalia Mariana; Poó, Fernando Martín


    The purpose of this study was to provide evidence of validity for the Mindful Attention Awareness Scale scores in an Argentine sample (Spanish-language version). Results indicated satisfactory psychometric properties (a one-factor structure, good item discrimination, high reliability, and significant correlations with additional measures). This…

  20. Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hogerton, John


    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.

  1. Molecular cytogenetic characterization of a new wheat Secale africanum 2Ra(2D) substitution line for resistance to stripe rust

    Indian Academy of Sciences (India)

    Mengping Lei; Guangrong Li; Sufen Zhang; Cheng Liu; Zujun Yang


    A stable, highly fertile wheat Secale africanum substitution line LF24, derived from the F7 generation of a cross between Mianyang11 (MY11) and Triticum durum, S. africanum amphiploid (YF) was identified through molecular cytogenetic analysis. Application of C-banding, in situ hybridization and molecular markers analysis showed that LF24 was a wheat S. africanum 2Ra(2D) substitution line. When inoculated with stripe rust isolates, T. durum and MY11 were highly susceptible, while S. africanum, YF and LF24 were immune. It is confirmed through molecular cytogenetic analysis that the stripe rust resistance of LF24 was derived from S. africanum chromosome 2Ra. We compared the banding patterns and disease resistance of reported chromosomes 2R from different S. cereale introduced into wheat background, and found that there was new stripe rust resistance gene(s) on S. africanum 2Ra. LF24 is a new substitution line which can be used as stripe rust resistant source in wheat improvement.

  2. Fast and flexible: argentine ants recruit from nearby trails. (United States)

    Flanagan, Tatiana P; Pinter-Wollman, Noa M; Moses, Melanie E; Gordon, Deborah M


    Argentine ants (Linepithema humile) live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources.

  3. Fast and flexible: argentine ants recruit from nearby trails.

    Directory of Open Access Journals (Sweden)

    Tatiana P Flanagan

    Full Text Available Argentine ants (Linepithema humile live in groups of nests connected by trails to each other and to stable food sources. In a field study, we investigated whether some ants recruit directly from established, persistent trails to food sources, thus accelerating food collection. Our results indicate that Argentine ants recruit nestmates to food directly from persistent trails, and that the exponential increase in the arrival rate of ants at baits is faster than would be possible if recruited ants traveled from distant nests. Once ants find a new food source, they walk back and forth between the bait and sometimes share food by trophallaxis with nestmates on the trail. Recruiting ants from nearby persistent trails creates a dynamic circuit, like those found in other distributed systems, which facilitates a quick response to changes in available resources.

  4. Malvinas: the Argentine Perspective of the Falkland’s Conflict (United States)


    commando operations was the book written by Isidoro Ruiz Moreno: Comandos en Accion . Munoz, Chacho, and Garasino‘s Malvinas; Album de Campana; Nora...defense of the Malvinas.32 The plan recognized that Argentina would face some difficulties defending the islands without the development of...significant military infrastructure and capabilities in the theatre. The defense plan was received on the 23rd of April 1982 by the Argentine Governor of

  5. Accelerated Mineralization of Pentachlorophenol in Soil upon Inoculation with Mycobacterium chlorophenolicum PCP1 and Sphingomonas chlorophenolica RA2. (United States)

    Miethling, R; Karlson, U


    Mineralization of pentachlorophenol (PCP) was studied in nonsterile soil from a PCP-contaminated site upon inoculation with two PCP-degrading bacterial strains. At spiked [(sup14)C]PCP concentrations of 30 and 100 mg/kg, the effects of organism type, different inoculation techniques, including structural amendment with sawdust and cell attachment to polyurethane (PU), as well as the effect of different inoculum sizes of 10(sup4) to 10(sup8) cells per g (dry weight) of soil were compared with PCP mineralization by indigenous bacteria. Gas chromatographic analysis was used to monitor PCP disappearance and to check mass balances. The survival and activity of the released bacteria were examined by immunofluorescence microscopy and respiking experiments. Noninoculated soil completely mineralized 30 mg of PCP per kg within 7 months but showed no or only low degradation activity at 100 mg/kg in the same period. Structural amendment with PU or sawdust initiated slow mineralization after half a year. Soil inoculation with Sphingomonas chlorophenolica RA2 shortened the mineralization time drastically to 1 month at 30 mg of PCP per kg using 10(sup8) cells per g, with approximately 80% of the added radioactivity being converted to CO(inf2). The inoculated cells disappeared rapidly, with a count of 2 x 10(sup6) cells per g after 2.3 months and nondetectability after 7 months. At 100 mg/kg, mineralization was slower because of PCP toxicity but approached completion within 7.5 months. The inhibition could be overcome by addition of sawdust (1 g/kg of soil), resulting in a mineralization rate of 3 to 4 mg/kg(middot)d. PU had the opposite effect. Lower inoculum densities resulted in prolonged lag phases and lower rates, although mineralization was still enhanced over the background level. At 30 mg of PCP per kg, inoculation with Mycobacterium chlorophenolicum PCP1 increased mineralization slightly over the indigenous bacterial activity, regardless of inoculum size, but only when

  6. Brazilian multipurpose reactor

    Energy Technology Data Exchange (ETDEWEB)



    The Brazilian Multipurpose Reactor (RMB) Project is an action of the Federal Government, through the Ministry of Science Technology and Innovation (MCTI) and has its execution under the responsibility of the Brazilian National Nuclear Energy Commission (CNEN). Within the CNEN, the project is coordinated by the Research and Development Directorate (DPD) and developed through research units of this board: Institute of Nuclear Energy Research (IPEN); Nuclear Engineering Institute (IEN); Centre for Development of Nuclear Technology (CDTN); Regional Center of Nuclear Sciences (CRCN-NE); and Institute of Radiation Protection and Dosimetry (IRD). The Navy Technological Center in Sao Paulo (CTMSP) and also the participation of other research centers, universities, laboratories and companies in the nuclear sector are important and strategic partnerships. The conceptual design and the safety analysis of the reactor and main facilities, related to nuclear and environmental licensing, are performed by technicians of the research units of DPD / CNEN. The basic design was contracted to engineering companies as INTERTHECNE from Brazil and INVAP from Argentine. The research units from DPD/CNEN are also responsible for the design verification on all engineering documents developed by the contracted companies. The construction and installation should be performed by specific national companies and international partnerships. The Nuclear Reactor RMB will be a open pool type reactor with maximum power of 30 MW and have the OPAL nuclear reactor of 20 MW, built in Australia and designed by INVAP, as reference. The RMB reactor core will have a 5x5 configuration, consisting of 23 elements fuels (EC) of U{sub 3}Si{sub 2} dispersion-type Al having a density of up to 3.5 gU/cm{sup 3} and enrichment of 19.75% by weight of {sup 23{sup 5}}U. Two positions will be available in the core for materials irradiation devices. The main objectives of the RMB Reactor and the other nuclear and radioactive

  7. Trail Pheromone Disruption of Argentine Ant Trail Formation and Foraging (United States)

    Suckling, D.M.; Peck, R.W.; Stringer, L.D.; Snook, K.; Banko, P.C.


    Trail pheromone disruption of invasive ants is a novel tactic that builds on the development of pheromone-based pest management in other insects. Argentine ant trail pheromone, (Z)-9-hexadecenal, was formulated as a micro-encapsulated sprayable particle and applied against Argentine ant populations in 400 m2 field plots in Hawai'i Volcanoes National Park. A widely dispersed point source strategy for trail pheromone disruption was used. Traffic rates of ants in bioassays of treated filter paper, protected from rainfall and sunlight, indicated the presence of behaviorally significant quantities of pheromone being released from the formulation for up to 59 days. The proportion of plots, under trade wind conditions (2-3 m s-1), with visible trails was reduced for up to 14 days following treatment, and the number of foraging ants at randomly placed tuna-bait cards was similarly reduced. The success of these trail pheromone disruption trials in a natural ecosystem highlights the potential of this method for control of invasive ant species in this and other environments. ?? Springer Science+Business Media, LLC 2010.

  8. The First Molecular Characterization of Picocyanobacteria from the Argentine Sea

    Directory of Open Access Journals (Sweden)

    Macarena Perez-Cenci


    Full Text Available Picocyanobacteria are abundant throughout the world’s oceans. Particularly, it has been reported that Synechococcus strains have a wide latitudinal distribution, from polar to tropical waters. However, their molecular characterization in the Southwest Atlantic Ocean is still missing. We analyzed Synechococcus genetic diversity in a sector of the Argentine Sea, one of the richest biological areas of the world oceans. 16S rRNA amplicons obtained after PCR amplification of environmental DNA extracted from water samples of this area were used for DGGE and sequenced. Only Synechococcus sequences could be retrieved. On the other hand, we isolated two Synechococcus strains from the environment. Our analyses revealed that the clade I group was widespread from latitude 38°S to 48°S and that can coexist with clade IV strains in shelf waters. The cooccurrence of these two clades may be related to an adaptation to high-nutrient/low-temperature waters. Our data are the first report on Synechococcus ecotypes that would be important contributors to phytoplankton biomass in the Argentine Sea, one of the richest biological areas of the world oceans.

  9. New mutualism for old: indirect disruption and direct facilitation of seed dispersal following Argentine ant invasion. (United States)

    Rowles, Alexei D; O'Dowd, Dennis J


    The indirect effects of biological invasions on native communities are poorly understood. Disruption of native ant communities following invasion by the Argentine ant (Linepithema humile) is widely reported to lead indirectly to the near complete collapse of seed dispersal services. In coastal scrub in southeastern Australia, we examined seed dispersal and handling of two native and two invasive alien plant species at Argentine ant-invaded or -uninvaded sites. The Argentine ant virtually eliminates the native keystone disperser Rhytidoponera victoriae, but seed dispersal did not collapse following invasion. Indeed, Argentine ants directly accounted for 92% of all ant-seed interactions and sustained overall seed dispersal rates. Nevertheless, dispersal quantity and quality among seed species differed between Argentine ant-invaded and -uninvaded sites. Argentine ants removed significantly fewer native Acacia retinodes seeds, but significantly more small seeds of invasive Polygala myrtifolia than did native ants at uninvaded sites. They also handled significantly more large seeds of A. sophorae, but rarely moved them >5 cm, instead recruiting en masse, consuming elaiosomes piecemeal and burying seeds in situ. In contrast, Argentine ants transported and interred P. myrtifolia seeds in their shallow nests. Experiments with artificial diaspores that varied in diaspore and elaiosome masses, but kept seed morphology and elaiosome quality constant, showed that removal by L. humile depended on the interaction of seed size and percentage elaiosome reward. Small diaspores were frequently taken, independent of high or low elaiosome reward, but large artificial diaspores with high reward instead elicited mass recruitment by Argentine ants and were rarely moved. Thus, Argentine ants appear to favour some diaspore types and reject others based largely on diaspore size and percentage reward. Such variability in response indirectly reduces native seed dispersal and can directly

  10. Antibiotic sensitivity of an Argentine strain collection of Moraxella bovis. (United States)

    Zielinski, G; Piscitelli, H; Perez-Monti, H; Stobbs, L A


    The antimicrobial susceptibility of 88 isolates of Moraxella bovis of Argentine origin was evaluated for 12 antimicrobials by broth microdilution procedures. The isolates had a minimum inhibitory concentration (MIC90) of or = 32 microg/mL to lincomycin. Modal MIC values for these antimicrobials were as follows: enrofloxacin, 0.03 microg/mL; ceftiofur, 0.06 pg/mL; ampicillin, 0.25 microg/mL; florfenicol, gentamicin, erythromycin, and oxytetracycline, 0.5 microg/mL; tilmicosin, 1.0 microg/mL; tylosin and spectinomycin, 4.0 microg/mL; lincomycin and erythromycin, 16 microg/mL; and trimethoprim/ sulfamethoxazole, < or = 0.25/4.75 microg/mL. These data show that all antimicrobials except lincomycin have MICs suggestive of sensitivity in vitro, though confirmation of clinical efficacy can only be properly assessed based on pharmacologic and/or clinical data to support the MIC values.

  11. Assessment of the Applicability of Total Quality Leadership into the Argentine Army. (United States)


    LEADERSHIP INTO THE ARGENTINE ARMY by Gustavo A. Landa Major, Argentine Army Engineer, Escuela Superior Tecnica , 1990 Submitted in partial fulfillment...needed to check the population reality. Different mental model [Ref 16:p. 174] may be present in the minds of the Generals. Operational definitions (see... mental model at every level. * Current promotion system does not encourage self-education. * Some possible degree of lack of confidence from senior

  12. Networks in Argentine agriculture: a multiple-case study approach

    Directory of Open Access Journals (Sweden)

    Sebastián Senesi


    Full Text Available Argentina is among the four largest producers of soybeans, sunflower, corn, and wheat, among other agricultural products. Institutional and policy changes during the 1990s fostered the development of Argentine agriculture and the introduction of innovative process and product technologies (no-till, agrochemicals, GMO, GPS and new investments in modern, large-scale sunflower and soybean processing plants. In addition to technological changes, a "quiet revolution" occurred in the way agricultural production was carried out and organized: from self-production or ownership agriculture to a contract-based agriculture. The objective of this paper is to explore and describe the emergence of networks in the Argentine crop production sector. The paper presents and describes four cases that currently represent about 50% of total grain and oilseed production in Argentina: "informal hybrid form", "agricultural trust fund", "investor-oriented corporate structure", and "network of networks". In all cases, hybrid forms involve a group of actors linked by common objectives, mainly to gain scale, share resources, and improve the profitability of the business. Informal contracts seem to be the most common way of organizing the agriculture process, but using short-term contracts and sequential interfirm collaboration. Networks of networks involve long-term relationships and social development, and reciprocal interfirm collaboration. Agricultural trust fund and investor-oriented corporate structures have combined interfirm collaboration and medium-term relationships. These organizational forms are highly flexible and show a great capacity to adapt to challenges; they are competitive because they enjoy aligned incentives, flexibility, and adaptability.

  13. H Reactor (United States)

    Federal Laboratory Consortium — The H Reactor was the first reactor to be built at Hanford after World War II.It became operational in October of 1949, and represented the fourth nuclear reactor on...

  14. Insecticide transfer efficiency and lethal load in Argentine ants

    Energy Technology Data Exchange (ETDEWEB)

    Hooper-Bui, L.M. [Department of Environmental Science, Louisiana State University, Baton Rouge, LA 70803 (United States); Department of Entomology, University of California, Riverside, CA 92521 (United States); Kwok, E.S.C. [Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92521 (United States); Buchholz, B.A., E-mail: [Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States); Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Rust, M.K. [Department of Entomology, University of California, Riverside, CA 92521 (United States); Eastmond, D.A. [Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92521 (United States); Vogel, J.S. [Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States)


    Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of {sup 14}C-sucrose, {sup 14}C-hydramethylnon, and {sup 14}C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

  15. Active tectonics in the Argentine Precordillera and Western Sierras Pampeanas

    Directory of Open Access Journals (Sweden)

    L.L. Siame


    Full Text Available The Andean foreland of western Argentina (28°S-33°S corresponds to retroarc deformations associated with the ongoing flat subduction of the Nazca plate beneath the South American lithosphere. This region is characterized by high levels of seismic activity and crustal active faulting. To improve earthquake source identification and characterization in the San Juan region, data from seismology, structural geology and quantitative geomorphology were integrated and combined to provide a seismotectonic model. In this seismotectonic model, the Andean back-arc of western Argentina can be regarded as an obliquely converging foreland where Plio-Quaternary deformations are partitioned between strike-slip and thrust motions that are localized on the E-verging, thin-skinned Argentine Precordillera, and the W-verging thick-skinned Sierras Pampeanas, respectively. In this seismotectonic model, the Sierra Pie de Palo appears to be a key structure playing a major role in the partitioning of the Plio-Quaternary deformations.

  16. Feeding strategy and cannibalism of the Argentine hake Merluccius hubbsi. (United States)

    Ocampo Reinaldo, M; González, R; Romero, M A


    The diet composition and feeding strategy of the Argentine hake Merluccius hubbsi in the San Matías Gulf were analysed in order to use this information for the sustainable management of the fishery. Merluccius hubbsi behaved as an opportunistic predator. Small M. hubbsi consumed planktonic crustaceans, whereas medium and large fish ate numerous prey taxa with low frequency of occurrence and variable specific abundance. Intra- and intercohort cannibalism were detected in all size groups and were particularly significant in large M. hubbsi. Medium-sized M. hubbsi consumed small conspecifics and large-sized M. hubbsi consumed both small and medium M. hubbsi. These results indicate that the removal of large M. hubbsi by fishing may increase the risk of overfishing by two combined effects: a direct effect of recruitment-overfishing and an indirect effect of growth-overfishing through an enhanced cannibalism of medium M. hubbsi on small M. hubbsi. Intra- and intercohort cannibalism and other trophic relationships in the M. hubbsi should therefore be considered explicitly in stock assessment models.

  17. [Distribution of Lutzomyia longipalpis in the Argentine Mesopotamia, 2010]. (United States)

    Salomon, Oscar D; Fernandez, Maria S; Santini, María S; Saavedra, Silvina; Montiel, Natalia; Ramos, Marina A; Rosa, Juan R; Szelag, Enrique A; Martinez, Mariela F


    The first case of visceral leishmaniasis (VL) in Argentina was reported in 2006 in Posadas, Misiones. During the summer 2008-2009 Lutzomyia longipalpis, the VL vector, and canine VL cases were already spread along the province of Corrientes. In order to know the distribution of VL risk, systematic captures of the vector were performed between February and March 2010, in 18 areas of the provinces of Entre Ríos and Corrientes, and the city of Puerto Iguazú, Misiones, with a total of 313 traps/night. We confirmed the presence of Lu. longipalpis, for the first time in Chajarí (Entre Ríos), Alvear, La Cruz, Curuzú Cuatiá and Bella Vista (Corrientes), and Puerto Iguazú (Misiones). In Santo Tome and Monte Caseros (Corrientes), where the vector had been previously reported, traps with more samples were obtained with 830 and 126 Lu. Longipalpis trap/site/night respectively. These results show that the vector of urban VL continues spreading in the Argentine territory. Simultaneously, the spread of the parasite and the resulting human VL cases are associated with the dispersion of reservoirs, infected dogs, with or without clinical symptoms or signs, due to human transit.

  18. Fragile-X mental retardation: molecular diagnosis in Argentine patients. (United States)

    Florencia, Giliberto; Irene, Szijan; Veronica, Ferreiro


    Fragile-X-syndrome (FXS) is the most common type of inherited cognitive impairment. The underlying molecular alteration consists of a CGG-repeat amplification within the FMR-1 gene. The phenotype is only apparent once a threshold in the number of repeats has been exceeded (full mutation). The aim of this study was to characterize the FMR-1 CGG-repeat status in Argentine patients exhibiting mental retardation. A total of 330 blood samples from patients were analyzed by PCR and Southern blot analysis. Initially, DNA from 78 affected individuals were studied by PCR. Since this method is unable to detect high molecular weight alleles, however, we undertook a second approach using the Southern blotting technique to analyze the CGG repeat number and methylation status. Southern blot analysis showed an altered pattern in 14 out of 240 (6%) unrelated patients, with half of them presenting a mosaic pattern. Eight out of 17 families (47%) showed a (suggest deleting highlight). The characteristic FXS pattern was identified in 8/17 families (47%), and in 4 of these families 25% of the individuals presented with a mosaic model. The expansion from pre-mutation to full mutation was shown to occur both at the pre and post zygotic levels. The detection of FXS mutations has allowed us to offer more informed genetic counseling, prenatal diagnosis and reliable patient follow-up.

  19. Reactor Physics

    Energy Technology Data Exchange (ETDEWEB)

    Ait Abderrahim, A


    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.

  20. Reactor safeguards

    CERN Document Server

    Russell, Charles R


    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

  1. Reactor operation

    CERN Document Server

    Shaw, J


    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

  2. Perspectives on Argentine Migration to Spain: Oral, Journal and Film Sources

    Directory of Open Access Journals (Sweden)

    Susana Schmidt


    Full Text Available This contribution takes up our doctoral research –Argentine migrationto Spain- to share some theoretical-methodological considerations.We refer to the conceptualization of "transnational social spaces," an approach that allows us to consider migration in its double dimension origin/destination and is particularly useful to thing the relationship between migration and creation of social and cultural ties in the Hispano-Argentine or Argentine-Spanish space. Similarly, the transnational spaces approach allows to put in dialog diverse social groups involved in the phenomenon: the migrants themselves, whose life stories are analysed by using oral sources; the society of origin and the host society, analysing collective image through journal sources; the filmmakers, whose migration stories we discussmigration through various fiction films; and, of course, historians and other social scientists who study these migrations.

  3. Reactor Neutrinos


    Soo-Bong Kim; Thierry Lasserre; Yifang Wang


    We review the status and the results of reactor neutrino experiments. Short-baseline experiments have provided the measurement of the reactor neutrino spectrum, and their interest has been recently revived by the discovery of the reactor antineutrino anomaly, a discrepancy between the reactor neutrino flux state of the art prediction and the measurements at baselines shorter than one kilometer. Middle and long-baseline oscillation experiments at Daya Bay, Double Chooz, and RENO provided very ...

  4. Argentine experience in the field of illegal immigration. (United States)

    Villar, J M


    This article provides a brief history of Argentine policy toward migratory flows from neighboring countries and Europe, and concludes with statistics on the number of foreigners in Argentina in the 1970-80 period. Measures passed during the 1940s and 1950s were aimed at providing amnesty for foreigners who were residing in Argentina without immigrant status. However, the lack of an adequate administrative structure to regulate foreigners at the borders was a drawback for migration authorities and limited the possiblility of applying admission criteria effectively. By 1970, there were 583,000 foreigners from neighboring countries living in Argentina, which represented a 25% increase from 1960. 42% of these migrants were in the metropolitan region of the country, indicative of a shift away from employment in agriculture. Decree No. 87, passed in 1974, represented an extension of a migration policy aimed at granting ample facilities for permanent residence to aliens from contiguous countries and was designed to prevent abuse of clandestine workers by employers. As a result of this measure, 150,000 foreigners were able to settle legally in the country. A 1981 law, yet to be implemented, establishes a new legal framework aimed at fostering immigration and regulating the admission of foreigners. To attain the objective of settling workers in areas of the country considered of prime importance to economic development, the law provides for infrastructural investments and promotional measures in areas such as tax exemption and the granting of credit. The 1980 National Population Census indicated there were 677,000 foreigners from neighboring countries in Argentina. In that year, foreigners comprised 2.4% of the country's population and 3.1% of the inhabitants of the metropolitan region. These figures are indicative of a decline in the growth of immigration, most likely due to the decline in the purchasing power of workers' salaries in the late 1970s.

  5. DNA barcoding identifies Argentine fishes from marine and brackish waters.

    Directory of Open Access Journals (Sweden)

    Ezequiel Mabragaña

    Full Text Available BACKGROUND: DNA barcoding has been advanced as a promising tool to aid species identification and discovery through the use of short, standardized gene targets. Despite extensive taxonomic studies, for a variety of reasons the identification of fishes can be problematic, even for experts. DNA barcoding is proving to be a useful tool in this context. However, its broad application is impeded by the need to construct a comprehensive reference sequence library for all fish species. Here, we make a regional contribution to this grand challenge by calibrating the species discrimination efficiency of barcoding among 125 Argentine fish species, representing nearly one third of the known fauna, and examine the utility of these data to address several key taxonomic uncertainties pertaining to species in this region. METHODOLOGY/PRINCIPAL FINDINGS: Specimens were collected and morphologically identified during crusies conducted between 2005 and 2008. The standard BARCODE fragment of COI was amplified and bi-directionally sequenced from 577 specimens (mean of 5 specimens/species, and all specimens and sequence data were archived and interrogated using analytical tools available on the Barcode of Life Data System (BOLD; Nearly all species exhibited discrete clusters of closely related haplogroups which permitted the discrimination of 95% of the species (i.e. 119/125 examined while cases of shared haplotypes were detected among just three species-pairs. Notably, barcoding aided the identification of a new species of skate, Dipturus argentinensis, permitted the recognition of Genypterus brasiliensis as a valid species and questions the generic assignment of Paralichthys isosceles. CONCLUSIONS/SIGNIFICANCE: This study constitutes a significant contribution to the global barcode reference sequence library for fishes and demonstrates the utility of barcoding for regional species identification. As an independent assessment of alpha

  6. Genetic variability and population structure in loci related to milk production traits in native Argentine Creole and commercial Argentine Holstein cattle

    Directory of Open Access Journals (Sweden)

    Golijow C.D.


    Full Text Available Many cattle breeds have been subjected to high selection pressure for production traits. Consequently, population genetic structure and allelic distribution could differ in breeds under high selection pressure compared to unselected breeds. Analysis of k-casein, aS1-casein and prolactin gene frequencies was made for Argentine Creole (AC and Argentine Holstein (AH cattle herds. The calculated FST values measured the degree of genetic differentiation of subpopulations, depending on the variances of gene frequencies.The AC breed had considerably more variation among herds at the aS1-casein and k-casein loci. Conservation strategies should consider the entire AC population in order to maintain the genetic variability found in this native breed.

  7. Argentine Hydrellia Robineau-Desvoidy (Diptera, Ephydridae): new species and key to identification. (United States)

    Rodrigues Júnior, Francisco De Assis; Mathis, Wayne Nielsen; Hauser, Martin


    Hydrellia egeriae sp. nov., a new species of Hydrellia from Campana (34 14' 04 S, 58 52' 32 W) and Hurlingham (3435'14 S, 5838'27 W), Buenos Aires province, Argentina is described. A key to the Argentine Hydrellia species is presented.

  8. English as an Instrumental Language: Language Displacement in the Anglo-Argentine Community. (United States)

    Cortes-Conde, Florencia


    Surveyed 99 Anglo-Argentine students aged 10 through 18 at five Spanish-English bilingual schools in Buenos Aires about their language attitudes and usage. It found that, despite the prestige of the English language, Spanish had become the dominant language for most. Age and place of residency in Buenos Aires also had a significant effect on…

  9. Powerful motors: Kinship, citizenship and the transformation of the Argentine oil industry (United States)

    Shever, Elana

    The privatization of the Argentine oil industry has been described as an unprecedented transfer of property, capital and control from the state to the corporate sphere, but this study demonstrates that the privatization process is better understood as a transformation of the historical configurations of oil-fueled development, political communities and human subjectivities. This dissertation probes the development of the state-led oil industry, and the shift to a corporate-led one, through an ethnography of Argentines differently positioned in relation to the global oil industry. The ethnography explores the lives of middle class oil workers and their families in Northwest Patagonia, impoverished residents of the shanty neighborhoods near the refineries in metropolitan Buenos Aires, and affluent employees of the translocal corporations operating in the Argentine oil fields. After the Introduction delineates this study's four principal interventions into anthropological scholarship, each subsequent chapter engages a particular problem that cuts across the Argentine oil fields and the anthropological theoretical fields. Chapter Two scrutinizes the historical construction of the Argentine subterritory as a "natural" space of value. Chapters Three and Four investigate the articulation of capitalist production and filial reproduction. These chapters argue that sentiment is a crucial generative force that has shaped the oil industry, company towns and worker families from the founding of the state-owned oil company in beginning of the twentieth century to its conversion into a corporate-owned one at the century's close. Chapters Five and Six examine the emergence of consumer citizenship and corporate citizenship out of Argentine neoliberalismo and its transformation of the oil industry. They argue that consumer and corporate citizenship are both reformulations of the older traditions of liberalism and Peronism. All the chapters of this dissertation illustrate that the

  10. Multifunctional reactors

    NARCIS (Netherlands)

    Westerterp, K.R.


    Multifunctional reactors are single pieces of equipment in which, besides the reaction, other functions are carried out simultaneously. The other functions can be a heat, mass or momentum transfer operation and even another reaction. Multifunctional reactors are not new, but they have received much

  11. Comparative leaf anatomy in argentine Galactia species Anatomía comparada de hoja en especies argentinas de Galactia


    G. M. Tourn; M. T. Cosa; G. G. Roitman; Silva,M.P.


    A comparative study of anatomical characters of the leaves of argentine species of Genera Galactia was carried out in order to evaluate their potential value in Taxonomy. In Argentine 14 species and some varieties from Sections Odonia and Collaearia can be found. Section Odonia: G. benthamiana Mich., G. dubia DC., G. fiebrigiana Burkart var. correntina Burkart, G. glaucophylla Harms, G. gracillima Benth., G. latisiliqua Desv., G. longifolia (Jacq.) Benth., G. marginalis Benth., G. striata (Ja...

  12. Reactor vessel


    Makkee, M.; Kapteijn, F.; Moulijn, J.A


    A reactor vessel (1) comprises a reactor body (2) through which channels (3) are provided whose surface comprises longitudinal inwardly directed parts (4) and is provided with a catalyst (6), as well as buffer bodies (8, 12) connected to the channels (3) on both sides of the reactor body (2) and comprising connections for supplying (9, 10, 11) and discharging (13, 14, 15) via the channels (3) gases and/or liquids entering into a reaction with each other and substances formed upon this reactio...

  13. Ce-Fe-modified zeolite-rich tuff to remove Ba(2+)-like (226)Ra(2+) in presence of As(V) and F(-) from aqueous media as pollutants of drinking water. (United States)

    Olguín, María Teresa; Deng, Shuguang


    The sorption behavior of the Ba(2+)-like (226)Ra(2+) in the presence of H2AsO4(-)/HAsO4(2-) and F(-) from aqueous media using Ce-Fe-modified zeolite-rich tuff was investigated in this work. The Na-modified zeolite-rich tuff was also considered for comparison purposes. The zeolite-rich tuff collected from Wyoming (US) was in contact with NaCl and CeCl3-FeCl3 solutions to obtain the Na- and Ce-Fe-modified zeolite-rich tuffs (ZUSNa and ZUSCeFe). These zeolites were characterized by scanning electron microscopy and X-ray diffraction. The BET-specific surface and the points of zero charge were determined as well as the content of Na, Ce and Fe by neutron activation analysis. The textural characteristics and the point of zero charge were changed by the presence of Ce and Fe species in the zeolitic network. A linear model described the Ba(2+)-like (226)Ra(2+) sorption isotherms and the distribution coefficients (Kd) varied with respect to the metallic species present in the zeolitic material. The As(V) oxianionic chemical species and F(-) affected this parameter when the Ba(2+)-like (226)Ra(2+)-As(V)-F(-) solutions were in contact with ZUSCeFe. The H2AsO4(-)/HAsO4(2-) and F(-) were adsorbed by ZUSCeFe in the same amount, independent of the concentration of Ba(2+)-like (226)Ra(2+) in the initial solution.

  14. Abstract bodies, concrete risks: clinical devices and the health of ova donors in Argentine reproductive medicine


    Lucía Ariza


    Using a methodological perspective grounded in science and technology studies, this article analyzes two sociotechnical devices used in Argentine reproductive medicine (biostatistical measures and donation registries) with the aim of controlling both the so-called “genetic risk” arising from the use of donated ova as well as the health risks to female donors. By examining how the deployment of monitoring criteria disregards the specificity of ova donation, the article suggests that it is not ...

  15. Therapeutic Argentine tango dancing for people living with Parkinson’s disease: a feasibility study


    Blandy, Laura M.; Meg E. Morris; Winifred A Beevers


    Background: Individuals living with Parkinson’s disease (PD) can experience a range of movement disorders. Therapeutic dance is enjoyable and thought to improve mobility, balance and well being in some people with PD. The primary objective of this study was to evaluate the feasibility and safety of a 4 week Argentine tango dance program for people with PD. Methods: Six community dwelling individuals with mild-moderate PD were recruited from Parkinson’s support groups, movement disorder clini...

  16. The Falklands War: Understanding the Power of Context in Shaping Argentine Strategic Decisions (United States)


    Malvinas—La Defensa de Puerto Argentino, Comandos en Accion and Testimonio de su Gobernador.65 Additional insight into the origins of the conflict can be... planning . For a defending force, in this case the Argentines, the goal 128 Stewart, 60. 129... planned naval movement against the British task force. The attack was to be a two-pronged assault with the Belgrano leading the southern element of

  17. Viral Strain Dependent Differences in Experimental Argentine Hemorrhagic Fever (Junin Virus) Infection of Guinea Pigs (United States)


    Nacional de Estudios Sobre Virosis Hemorragicas, Pergamino, Province de Buenos Aires, S Argentina Key Words. Argentine hemorrhagic fever virus • Junin...Gonzalez, P.H.: Maiztegui. J. I.: plaques. Proc. Soc. exp. Biol. Med. 130:1013 1019 Laguens, R.P.: Estudio morfologico de la medula (1969). osea humana en... casos de fiebre hemorra- Atlanta 1976). gica Argentina. Pensa med. Argentina 56.605 614 14 The Subcommittee on Arbovirus Laborator (1969). Safety of

  18. Draft Genome Sequences of Four Enterococcus faecium Strains Isolated from Argentine Cheese (United States)

    Martino, Gabriela P.; Quintana, Ingrid M.; Espariz, Martín; Blancato, Victor S.; Gallina Nizo, Gabriel; Esteban, Luis


    We report the draft genome sequences of four Enterococcus faecium strains isolated from Argentine regional cheeses. These strains were selected based on their technological properties, i.e., their ability to produce aroma compounds (diacetyl, acetoin, and 2,3-butanediol) from citrate. The goal of our study is to provide further genetic evidence for the rational selection of enterococci strains based on their pheno- and genotype in order to be used in cheese production. PMID:26847907

  19. Efficacy of Argentine propolis formulation for topical treatment of canine otitis externa


    L.A Lozina; M.E Peichoto; S.I Boehringer; P. Koscinczuk; G.E Granero; O.C Acosta


    The therapeutic effects of Argentine propolis ear drop formulation on canine otitis externa were evaluated. Forty-eight dogs with symptoms of otitis externa were randomly assigned to double-blinded, controlled clinical trial to evaluate the efficacy of topical formulation with propolis versus a topical placebo in the treatment of otitis externa. The propolis preparation and placebo were administrated into both external ear canals, twice daily for 14 days. Throughout the study, clinical examin...

  20. Inhibition of cyclooxygenase activity by standardized hydroalcoholic extracts of four Asteraceae species from the Argentine Puna


    Alberto,M.R.; Zampini,I.C.; Isla, M. I.


    We determined the anti-inflammatory activity of standardized extracts of four medicinal plant species (Baccharis incarum, B. boliviensis, Chuquiraga atacamensis, Parastrephia lucida) that grow in the Argentine Puna (3800 m above sea level) and that are used to reduce oxidative stress and alleviate gout and arthritic pain. The extracts of plant aerial parts were standardized in terms of total phenolic compounds and flavone/flavanone content and free radical scavenging activity. All extracts sh...

  1. The executive and legislative branches and trade unions in the Argentine social security reform

    Directory of Open Access Journals (Sweden)

    Sidney Jard da Silva


    Full Text Available This article analyzes the interaction between organized labor and government during reform of the pension system in Argentina. The purpose is to investigate the political and institutional conditions favorable to the inclusion of trade unions in a negotiated pension reform process. The Argentine pattern of union-government interaction was shown to be shaped more by the peculiarities of the decision-making process than by the demands and power of union organizations.

  2. NUCLEAR REACTOR (United States)

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


    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.

  3. Reactor Neutrinos

    Directory of Open Access Journals (Sweden)

    Soo-Bong Kim


    Full Text Available We review the status and the results of reactor neutrino experiments. Short-baseline experiments have provided the measurement of the reactor neutrino spectrum, and their interest has been recently revived by the discovery of the reactor antineutrino anomaly, a discrepancy between the reactor neutrino flux state of the art prediction and the measurements at baselines shorter than one kilometer. Middle and long-baseline oscillation experiments at Daya Bay, Double Chooz, and RENO provided very recently the most precise determination of the neutrino mixing angle θ13. This paper provides an overview of the upcoming experiments and of the projects under development, including the determination of the neutrino mass hierarchy and the possible use of neutrinos for society, for nonproliferation of nuclear materials, and geophysics.

  4. Chemical Reactors. (United States)

    Kenney, C. N.


    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)

  5. Reactor Neutrinos


    Lasserre, T.; Sobel, H.W.


    We review the status and the results of reactor neutrino experiments, that toe the cutting edge of neutrino research. Short baseline experiments have provided the measurement of the reactor neutrino spectrum, and are still searching for important phenomena such as the neutrino magnetic moment. They could open the door to the measurement of coherent neutrino scattering in a near future. Middle and long baseline oscillation experiments at Chooz and KamLAND have played a relevant role in neutrin...

  6. Sonochemical Reactors. (United States)

    Gogate, Parag R; Patil, Pankaj N


    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.

  7. Hydrological cycles and trends in the NW Argentine Andes since 1940 (United States)

    Castino, Fabiana; Bookhagen, Bodo; Strecker, Manfred


    Strong spatiotemporal variability characterizes the hydrometeorological pattern in the NW Argentine Andes, draining parts of the most populated and economically important areas of South America. During the summer monsoon season (DJF), the eastern flanks of the central Andes are characterized by deep convection, exposing them to extreme hydrometeorological events. These often result in floods and landslides with disastrous effects on the local populations. Here, we analyze river discharge to explore long-term hydrological variability in NW Argentine Andes and the linked climate controlling processes. We rely on 13 daily river discharge time series relevant to drainage basins spanning several size orders (102-104 km2) starting in 1914 and define different hydro-climate indices both for the mean and the extreme hydrological events. We apply quantile regression to investigate long-term trends and spectral analysis associated with cross-correlation with SST-based climate indices to identify links to large-scale climate variability modes. River discharge presents a pronounced and coherent variability signal in South America, particularly for wide drainage basins, such as the Amazon and Paraná/La Plata rivers, strongly associated to Pacific and Atlantic Oceans Sea Surface Temperature (SST) anomalies (i.e. ENSO, PDO, AMO). Our analysis evidences that in the NW Argentine Andes, mean discharge values are characterized by statistically significant, mostly positive, long-term trends since 1940, whereas the extreme events present a more non-unidirectional trend pattern. Also, coherent multi-annual to multi-decadal cycles characterizing the discharge pattern have been identified, suggesting that processes linked to SST anomaly-modes strongly control the hydrometeorology variability in the NW Argentina Andes.

  8. Hantavirus reservoir Oligoryzomys longicaudatus spatial distribution sensitivity to climate change scenarios in Argentine Patagonia

    Directory of Open Access Journals (Sweden)

    González Paula LM


    Full Text Available Abstract Background Oligoryzomys longicaudatus (colilargo is the rodent responsible for hantavirus pulmonary syndrome (HPS in Argentine Patagonia. In past decades (1967–1998, trends of precipitation reduction and surface air temperature increase have been observed in western Patagonia. We explore how the potential distribution of the hantavirus reservoir would change under different climate change scenarios based on the observed trends. Methods Four scenarios of potential climate change were constructed using temperature and precipitation changes observed in Argentine Patagonia between 1967 and 1998: Scenario 1 assumed no change in precipitation but a temperature trend as observed; scenario 2 assumed no changes in temperature but a precipitation trend as observed; Scenario 3 included changes in both temperature and precipitation trends as observed; Scenario 4 assumed changes in both temperature and precipitation trends as observed but doubled. We used a validated spatial distribution model of O. longicaudatus as a function of temperature and precipitation. From the model probability of the rodent presence was calculated for each scenario. Results If changes in precipitation follow previous trends, the probability of the colilargo presence would fall in the HPS transmission zone of northern Patagonia. If temperature and precipitation trends remain at current levels for 60 years or double in the future 30 years, the probability of the rodent presence and the associated total area of potential distribution would diminish throughout Patagonia; the areas of potential distribution for colilargos would shift eastwards. These results suggest that future changes in Patagonia climate may lower transmission risk through a reduction in the potential distribution of the rodent reservoir. Conclusion According to our model the rates of temperature and precipitation changes observed between 1967 and 1998 may produce significant changes in the rodent

  9. A new species of Havelockia Pearson, 1903 from the Argentine Sea (Holothuroidea: Dendrochirotida: Sclerodactylidae). (United States)

    Martinez, Mariano I; Thandar, Ahmed S; Penchaszadeh, Pablo E


    Havelockia pegi sp. nov., is here described from shallow waters of the Argentine Sea. This new species is distinctive in the purple colouration of its tentacles, scarcity of body wall ossicles and the presence of rosette-shaped ossicles in both the introvert and the tentacles. It is not closely related to any of its congenors. This is the first record of a true sclerodactylid from Argentina. Thandarum hernandezi Martinez & Brogger, 2012, described in the family Sclerodactylidae, is now classified in the family Sclerothyonidae.

  10. The argentine territory as an international venue for the administration of punishment


    Argenti, Natalia


    El objetivo principal de este trabajo es poner de relieve los múltiples problemas que deberían afrontarse para que las cárceles argentinas administren las penas de acuerdo con el Estatuto de Roma (art. 103). La propuesta tiene eficacia cuantificable en términos del tratamiento humanitario de los reos y promueve, en general, el ejercicio de sus derechos más vitales y básicos. The primary goal of this work is to highlight the various problems that should be addressed so that Argentine prison...

  11. Equity during an economic crisis: financing of the Argentine health system. (United States)

    Cavagnero, Eleonora; Bilger, Marcel


    This article analyses the redistributive effect caused by health financing and the distribution of healthcare utilization in Argentina before and during the severe 2001/2002 economic crisis. Both dramatically changed during this period: the redistributive effect became much more positive and utilization shifted from pro-poor to pro-rich. This clearly demonstrates that when utilization is contingent on financing, changes can occur rapidly; and that an integrated approach is required when monitoring equity. From a policy perspective, the Argentine health system appears vulnerable to economic downturns mainly due to high reliance on out-of-pocket payments and the strong link between health insurance and employment.

  12. The first study of the micro-fauna of middle Cambrian olistoliths in the Argentine Precordillera


    Fahlgren, Elise; Tranvik, Maria


    This study implies a survey of a somewhat unexplored Cambrian carbonate formation in the Argentine Precordillera (AP) located in western Argentina, close to the city of San José de Jáchal. The carbonate platform of the AP is a unique piece of the South American geology and is in this study partly surveyed and compared with the Stephen Formation of northern Canada, a middle Cambrian unit renowned for its contents of exceptionally well preserved soft bodied fossils named the Burgess Shale biota...

  13. The widespread collapse of an invasive species: Argentine ants (Linepithema humile) in New Zealand



    Synergies between invasive species and climate change are widely considered to be a major biodiversity threat. However, invasive species are also hypothesized to be susceptible to population collapse, as we demonstrate for a globally important invasive species in New Zealand. We observed Argentine ant populations to have collapsed in 40 per cent of surveyed sites. Populations had a mean survival time of 14.1 years (95% CI = 12.9–15.3 years). Resident ant communities had recovered or partly re...

  14. Graphic correlation of Argentine Precordillera and North American Lower/Middle Ordovician sections

    Institute of Scientific and Technical Information of China (English)

    Walter C.Sweet; Guillermo L.Albanesi


    @@ Present work demonstrates that a level equivalent to the proposed Whiterockian basal GSSP can be located graphically in a composite section anchored by the Niquivil section of the Argentine Precordillera. The FAD of Cooperignathus aranda in the Niquivil composite section, a candidate for GSSP of the Lower/Middle Ordovician boundary, projects to a level very close to the FAD of Tripodus laevis in the Whiterockian reference section. The conodont-based framework reported here includes the potential for recognition of the proposed Whiterock Canyon-based GSSP, the Cooperignathus aranda-based GSSP, and, possibly, the Baltoniodus triangularisbased GSSP, recently proposed.

  15. Determination of TBT in water and sediment samples along the Argentine Atlantic coast. (United States)

    de Waisbaum, R G; Rodriguez, C; Nudelman, N Sbarbati


    Cases of imposex have been reported for some organisms living in areas of the Argentine Atlantic coast. Since this is one of the known effects of the anti-fouling agent tributyltin (TBT), quantitative determinations of organotins in samples of water and sediments collected from sites along the Argentine coast were carried out. Severe cases of imposex were first reported for two gastropod species living in the Mar del Plata area, and determinations of TBT in samples collected from this site gave extremely high values and showed a close correlation between the degree of imposex and TBT concentration. Recent investigations in the area have shown a significant decrease. Surveys were also conducted in sites that exhibit highly irregular coastal profiles to examine the relevance of physical environments. Alarming concentrations of TBT were determined in most of the sites where heavy boat traffic and/or marine activities occur, demonstrating the urgent need for regulations to avoid further input of TBT. Reports from other sites in South America reveal that this should be a subject of regional concern in order to avoid severe damage to the biodiversity of regional marine organisms.

  16. High-resolution stable isotope stratigraphy of the upper Cambrian and Ordovician in the Argentine Precordillera

    DEFF Research Database (Denmark)

    Sial, A.N.; Peralta, S.; Gaucher, C.;


    We report the occurrence of important carbon isotope excursions in early Paleozoic formations of the Eastern and Central Argentine Precordillera. The Steptoean positive isotope carbon excursion (SPICE) is known from North America, Kazakhstan, South China, Australia and South America, and the nega......We report the occurrence of important carbon isotope excursions in early Paleozoic formations of the Eastern and Central Argentine Precordillera. The Steptoean positive isotope carbon excursion (SPICE) is known from North America, Kazakhstan, South China, Australia and South America......, and the negative isotope carbon excursion (SNICE) has been described for the first time in South America. We report here the record of the SPICE and SNICE in a single section in the Eastern Precordillera. In the Central Precordillera, a minor middle Darriwilian positive carbon isotope excursion (MDICE) and a late...... Sandbian positive isotope carbon excursion, the GICE (~ + 3‰; C. bicornis biozone) are reported from two sections. One pre-GICE positive carbon-isotope excursion (Sandbian Sa1, N. gracilis biozone) in the Central Precordillera with a δ13C peak of ~ + 2‰ is, perhaps, equivalent to the positive Spechts Ferry...

  17. Nutrition and interference competition have interactive effects on the behavior and performance of Argentine ants. (United States)

    Kay, Adam D; Zumbusch, Taylor; Heinen, Justa L; Marsh, Tom C; Holway, David A


    Food availability often influences competitive outcomes through effects on consumer growth. Although it has received less attention, food availability may also affect competition through nutritional effects on behavior. One hypothesis linking nutrition and competition in ants posits that increased access to carbohydrates favors greater investment in worker traits that underlie behavioral dominance. We tested this hypothesis by varying dietary protein:carbohydrate (P:C) ratios and levels of interspecific interference for Argentine ants (Linepithema humile), a widespread invasive species. As predicted, colonies facing interference increased patrolling more when reared on low P:C diets; this result is the first demonstration of an interactive effect of nutrition and interference on ant colonies. Several results suggest that this dietary effect on patrolling was due primarily to changes in colony size rather than worker behavior. Colonies on lower P:C diets had lower worker mortality and larger final colony sizes. Diet had little effect on per capita patrolling, and worker behavior in performance assays depended more on previous exposure to interference than on diet. Our findings indicate that dietary P:C ratios can influence Argentine ant performance in a competitive environment and suggest a mechanism by which monopolization of carbohydrate-rich resources can help invasive ants displace native ant competitors.

  18. Optimisation in a natural system: Argentine ants solve the Towers of Hanoi. (United States)

    Reid, Chris R; Sumpter, David J T; Beekman, Madeleine


    Natural systems are a source of inspiration for computer algorithms designed to solve optimisation problems. Yet most 'nature-inspired' algorithms take only superficial inspiration from biology, and little is known about how real biological systems solve difficult problems. Moreover, ant algorithms, neural networks and similar methods are usually applied to static problems, whereas most biological systems have evolved to perform under dynamically changing conditions. We used the Towers of Hanoi puzzle to test whether Argentine ants can solve a potentially difficult optimisation problem. We also tested whether the ants can adapt to dynamic changes in the problem. We mapped all possible solutions to the Towers of Hanoi on a single graph and converted this into a maze for the ants to solve. We show that the ants are capable of solving the Towers of Hanoi, and are able to adapt when sections of the maze are blocked off and new sections installed. The presence of exploration pheromone increased the efficiency of the resulting network and increased the ants' ability to adapt to changing conditions. Contrary to previous studies, our study shows that mass-recruiting ant species such as the Argentine ant can forage effectively in a dynamic environment. Our results also suggest that novel optimisation algorithms can benefit from stronger biological mimicry.

  19. The cycles of Argentine wine exports / Los ciclos de las exportaciones de vino argentinas

    Directory of Open Access Journals (Sweden)

    Cerdá Juan Manuel


    Full Text Available This paper analyses the different episodes that the Argentina wine industry transited between the years 1980 to 2012, within a context of globalization of the wine-grape industry. In particular, we study the significance that some winemakers had in the process and the effect of the exchange rate and recipients of Argentine wine in the expansion of exports in recent years. The hypothesis of this article is that, from the 80 s, the winemakers observed in exports as a solution to face their most important crisis. This required a transformation of the industry to produce quality wines that could be sold on the international market. Thus, winemakers added to a century-old winemaking tradition new practices and strategies. On the other hand, over 30 years, various macroeconomic policies affect the overall industry growth, especially in exports. On balance, in this paper we propose to show that the growth of exports of Argentine wine was a sinuous and different path to the literature has been found for the “new world” exporters countries. The data was obtained from Instituto Nancional de Vitivinícultura (INV, Bolsa de Comercio de Mendoza and International Organisation of Vine and Wine (OIV as well as interviews collected on primary and secondary sources.

  20. Conflits et coopérations en territoire montagnard Mapuche (Argentine

    Directory of Open Access Journals (Sweden)

    Renaud Miniconi


    Full Text Available La question des autochtones est devenue, durant les deux dernières décennies, une préoccupation majeure dans différents pays du monde, comme en Argentine où environ 600 000 individus se reconnaissent comme tels, soit 1,5 % de sa population totale. Toutefois, ces populations sont encore trop souvent marginalisées à l’échelle de certaines régions, comme c’est le cas pour les Mapuche du Parc National Nahuel Huapi, situé dans les provinces du Rio Negro et de Neuquén. Si les textes internationaux et parfois nationaux réhabilitent certains droits humains essentiels de ces populations, les réalités locales sont plus contrastées, du fait d’intérêts souvent divergents des acteurs régionaux. Dans le contexte particulier d’une Argentine marquée par des difficultés d’accès à la propriété foncière pour une large part de la population, les parcs nationaux se révèlent être des outils pertinents, pour les populations autochtones, de recouvrement de leurs terres ancestrales, grâce en particulier aux processus de co-gestion participative mise en place sur ces territoires.

  1. Prosecuting International Crimes at National Level: Lessons from the Argentine ‘Truth-Finding Trials’

    Directory of Open Access Journals (Sweden)

    Elena Maculan


    Full Text Available Truth-finding trials (juicios por la verdad constitute a novel solution devised by the Argentine judicial system to cope with crimes committed by the past military dictatorship. This mechanism uses criminal courts as well as criminal procedure in order to investigate the truth about the dictatorship's crimes; however, the trials allow judges neither to establish criminal responsibility nor to punish the perpetrators of crimes. This limitation is due to the inability, imposed by the Full Stop and Due Obedience Laws, to prosecute the perpetrators of crimes.From the perspective of criminal law, truth-finding trials present two problematic features: firstly, their creation and regulation are set by judges, which has caused the development of many non-homogeneous local solutions and, secondly, their hybrid nature, which entails a possible subversion of conventional forms and goals in the context of the criminal trial.The paper also describes the current situation, since the Argentine impunity laws were declared unconstitutional and criminal proceedings reopened. The new framework provokes questions about the relationship between the reopened criminal trials and the truth-finding investigations, not only with regard to evidentiary issues but also with respect to the reason why the truth-finding investigations are still held.Finally, the shift from a non-punitive approach to the current full criminal accountability seems to suggest that truth-finding trials were merely a temporary solution, while the notion of the full prosecution and punishment of State crimes was never really set aside.

  2. Efficacy of Argentine propolis formulation for topical treatment of canine otitis externa

    Directory of Open Access Journals (Sweden)

    L.A Lozina


    Full Text Available The therapeutic effects of Argentine propolis ear drop formulation on canine otitis externa were evaluated. Forty-eight dogs with symptoms of otitis externa were randomly assigned to double-blinded, controlled clinical trial to evaluate the efficacy of topical formulation with propolis versus a topical placebo in the treatment of otitis externa. The propolis preparation and placebo were administrated into both external ear canals, twice daily for 14 days. Throughout the study, clinical examination and microbiological analysis of dogs ear exudates were made. The most frequent microorganisms isolated in culture media were: Malassezia pachydermatis (54.2%, Staphylococcus aureus (43.8%, coagulase-negative Staphylococcus (25.0%, Pseudomonas aeruginosa (20.8%, Candida albicans (18.8%, Proteus mirabilis (16.7%, Streptococcus spp. (16.7%, Enteroccocus faecalis (12.5%, Escherichia coli (12.5%, Staphylococcus intermedius (6.3%, Klebsiella spp. (4.2%, andCandida glabrata (2.1%. Whereas the control group did not recover from the infectious ear disease, the propolis preparation exhibited antimicrobial activity against most of the microorganisms isolated from samples of the treated group. In addition, no propolis-adverse effects were observed. This allowed propolis-treated patients to show a significant improvement of the clinical parameters. Thus, this new Argentine propolis ear drop formulation may be used for topical treatment of otitis externa in dogs.

  3. Analysis of genetic diversity and population structure in Argentine and Bolivian Creole cattle using five loci related to milk production

    Directory of Open Access Journals (Sweden)

    Lirón J.P.


    Full Text Available Data from five protein-coding loci related to dairy production were used to study the genetic diversity and population structure of Argentine and Bolivian Creole cattle breeds. Genomic DNA was extracted from blood samples of six Creole cattle breeds: Argentine (n = 230, Patagonian (n = 25; "Saavedreño" (n = 140, "Chaqueño Boliviano" (n = 30, "Yacumeño" (n = 27, and "Chusco" (n = 11. kappa-casein, beta-lactoglobulin, growth hormone and prolactin were measured by PCR-RFLP, while alphaS1-casein was typed by PCR-ASO. The results are discussed, focusing on: historical origin, recent differentiation and selection events, Zebu gene introgression, and population structure. This work shows that: (i For the studied genes, the observed gene frequency profiles of Argentine and Bolivian Creole cattle breeds were close to the data reported for Iberian breeds and for other South-American Creole cattle breeds which are historically related; (ii although Zebu gene introgression has been reported at the studied loci, these breeds seem to be far from the Zebu gene frequency profiles; and (iii the Argentine and Bolivian Creole cattle showed significant levels of subdivision, but each population has maintained its degree of genetic variability.

  4. Hybrid adsorptive membrane reactor (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)


    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.

  5. D and DR Reactors (United States)

    Federal Laboratory Consortium — The world's second full-scale nuclear reactor was the D Reactor at Hanford which was built in the early 1940's and went operational in December of 1944.D Reactor ran...

  6. Hybrid adsorptive membrane reactor (United States)

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


    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.

  7. Abstract bodies, concrete risks: clinical devices and the health of ova donors in Argentine reproductive medicine

    Directory of Open Access Journals (Sweden)

    Lucía Ariza


    Full Text Available Using a methodological perspective grounded in science and technology studies, this article analyzes two sociotechnical devices used in Argentine reproductive medicine (biostatistical measures and donation registries with the aim of controlling both the so-called “genetic risk” arising from the use of donated ova as well as the health risks to female donors. By examining how the deployment of monitoring criteria disregards the specificity of ova donation, the article suggests that it is not the absence of control measures and clinical criteria that produces an inadequate monitoring of such risks, but rather the concrete ways in which such measures are implemented that results in potential harms to the health of female donors.

  8. The widespread collapse of an invasive species: Argentine ants (Linepithema humile) in New Zealand. (United States)

    Cooling, Meghan; Hartley, Stephen; Sim, Dalice A; Lester, Philip J


    Synergies between invasive species and climate change are widely considered to be a major biodiversity threat. However, invasive species are also hypothesized to be susceptible to population collapse, as we demonstrate for a globally important invasive species in New Zealand. We observed Argentine ant populations to have collapsed in 40 per cent of surveyed sites. Populations had a mean survival time of 14.1 years (95% CI = 12.9-15.3 years). Resident ant communities had recovered or partly recovered after their collapse. Our models suggest that climate change will delay colony collapse, as increasing temperature and decreasing rainfall significantly increased their longevity, but only by a few years. Economic and environmental costs of invasive species may be small if populations collapse on their own accord.

  9. Loss of Wolbachia infection during colonisation in the invasive Argentine ant Linepithema humile

    DEFF Research Database (Denmark)

    Reuter, M.; Pedersen, Jes Søe; Keller, L.


    the phylogenies of Wolbachia and its arthropod hosts indicate that infection is frequently lost, but the causes of symbiont extinction have so far remained elusive. Here, we report data showing that colonisation of new habitats is a possible mechanism leading to the loss of infection. The presence and prevalence...... of Wolbachia were studied in three native and eight introduced populations of the Argentine ant Linepithema humile. The screening shows that the symbiont is common in the three native L. humile populations analysed. In contrast, Wolbachia was detected in only one of the introduced populations. The loss...... of infection associated with colonisation of new habitats may result from drift (founder effect) or altered selection pressures in the new habitat. Furthermore, a molecular phylogeny based on sequences of the Wolbachia wsp gene indicates that L. humile has been infected by a single strain. Horizontal...

  10. Moessbauer study of the Fe mineralogy in two different Argentine soils

    Energy Technology Data Exchange (ETDEWEB)

    Mijovilovich, A. [Departamento de Fisica, Comision Nacional de Energia Atomica (Argentina); Morras, H. [Instituto de Suelos, INTA-CIRN (Argentina); Causevic, H. [Universidad de Buenos Aires, Ciudad Universitaria, Facultad de Ciencias Exactas y Naturales (Argentina); Saragovi, C. [Departamento de Fisica, Comision Nacional de Energia Atomica (Argentina)


    Two Argentine soils featuring different characteristics and compositions (mollisols and ultisols) have been studied by Moessbauer spectroscopy and X-ray diffraction. The first type has a weakly developed profile with a solum thickness of 40 cm; the Fe oxyhydroxides are present in low concentrations in mixtures with other slightly weathered minerals (e.g., quartz, feldspars, 2 : 1 phyllosilicates, etc.). The second one is a typic kandihumult, which is a highly weathered red coloured, deep soil. The Fe oxyhydroxides are abundant, mixed mainly with kaolinite clay minerals. Analyses of iron mineralogy show hematite and goethite in both soils. Their ratio is low in the first case and high in the last case. Magnetite-maghemite are also present in both situations, but in the mollisol their content is much lower than in the ultisol. The mineralogy found is related to the different lithological characteristics and processes of pedological evolution on both soils.

  11. Copi et Puig, ovnis du théâtre argentin ?


    Souquet, Lionel


    C’est en 1968 que Copi (Raúl Damonte Botana, 1939-1987) publie sa première pièce, La journée d’une rêveuse puis, un an plus tard, la très iconoclaste Eva Peron. Par son milieu familial, Copi a baigné dès l’enfance dans la vie théâtrale internationale et a été fortement influencé par sa grand-mère, la dramaturge anarcho-féministe Salvadora Medina Onrubia de Botana. Mais, vivant en exil avec sa famille, Copi est coupé de la réalité de la scène argentine et il écrit d’ailleurs ses premières pièc...

  12. Screening of plants used in Argentine folk medicine for antimicrobial activity. (United States)

    Anesini, C; Perez, C


    Screening of 132 extracts from Argentine folk-medicinal plants for antimicrobial activity has been conducted using a penicillin G resistant strain of Staphylococcus aureus, Escherichia coli and Aspergillus niger as test microorganisms. Cephazolin, ampicillin and miconazole were used as standard antibiotics and concentration-response curves were obtained using the agar-well diffusion method. Boiling water extracts of plant materials were tested and 12 species were active against Staphylococcus aureus, whereas 10 were effective against Escherichia coli and 4 against Aspergillus niger. Tabebuia impetiginosa bark, Achyrocline sp. aerials parts, Larrea divaricata leaves, Rosa borboniana flowers, Punica granatum fruit pericarp, Psidium guineense fruit pericarp, Lithrea ternifolia leaves and Allium sativum bulbs produced some of the more active extracts.

  13. [Candid#1 vaccine against Argentine hemorrhagic fever produced in Argentina. Immunogenicity and safety]. (United States)

    Enria, Delia A; Ambrosio, Ana M; Briggiler, Ana M; Feuillade, María Rosa; Crivelli, Eleonora


    A clinical study in 946 human volunteers was done to compare Candid #1 vaccine manufactured in Argentina with the vaccine produced in USA that had been previously used. The efficacy was evaluated using immunogenicity measured by the detection of neutralizing antibodies as a subrogate marker. Safety was evaluated comparing the rate of adverse events. Both vaccines showed a comparable rate of seroconversion, slightly higher than the efficacy estimated from previous studies (95.5%). There were no severe adverse events related to the vaccines. The general events considered related to the vaccines were not clinically relevant and disappeared either spontaneously or with symptomatic treatment. Similar rates of adverse events (29.9% for the Argentine vaccine and 35.0% for the USA vaccine) were found for both vaccines. These included: headache, weakness, myalgias, mild low blood cell (ANMAT).


    Directory of Open Access Journals (Sweden)

    Esteban Serrani


    Full Text Available The objective of the paper is to analyze the path of the state oil company YPF, from privatization to its expropriation (1989-2012. In this process, it has a special emphasis on the identification and analysis of national peculiarities that explain why in the ‘90s YPF, one of the nation’s premier companies in history, was fully privatized (counter to the regional experience in Mexico, Venezuela and Brazil; and how, just twenty years later, the same company was again in state control, with an expropriation which was widely popular and parliamentary support. It also reviews the main consequences of deregulation and the opening in the Argentine oil sector, especially in the performance of --- since acquired all shares of YPF in 1999, to explain this path.

  15. Ethical and Civic Education. Difficulties during the Curricular Reform in Argentine Patagonia

    Directory of Open Access Journals (Sweden)

    Isabelino Siede


    Full Text Available DOI: What type of ethical and civic education is effectively provided at school? This article analyzes the curricular prescriptions of Ethical and Citizenship Education in primary schools of the Argentine Patagonia, as well as its relations and contradictions with the school practices of moral education It inquires the process of definition of the area in the context of the Educational Reform in the 90s. Also, it pursuits to remake the way it was incorporated in the provincial curriculum design. Throughout focus groups and interviews to teachers from different public and private schools of three towns from de north of Santa Cruz, we analyze the descriptions and expectative of the teachers about their teaching practice in the moral area, as well as the possible causes of the differences and the contradictions between the policies of the curricular statement and educational proposals offered at school.

  16. Use of remote sensing and GIS to identify Flamingo habitat in the Argentine Altiplano (United States)

    Boyle, Susan C.; Hoffer, Roger M.; Boyle, Terence P.; Bucher, Enrique H.


    The Argentine altiplano is a remote area which has never been adequately mapped. It is an arid region with harsh climate, little vegetation, sparse population, and an average elevation of over 3,500 feet. Little is known about the large populations of three species of flamingos which nest and feed in the altiplano lakes. In a study funded by the National Geographic Society satellite data (Landsat MSS and TM data) were used to map the location of major water bodies and to analyze the spectral characteristics of the aquatic ecosystems in the altiplano. A comparison of the two images revealed dramatic changes in the size, depth, and spectral reflectance of the lakes utilized by the flamingos.

  17. Development and validation of an Argentine set of facial expressions of emotion. (United States)

    Vaiman, Marcelo; Wagner, Mónica Anna; Caicedo, Estefanía; Pereno, Germán Leandro


    Pictures of facial expressions of emotion are used in a wide range of experiments. The last decade has seen an increase in the number of studies presenting local sets of emotion stimuli. However, only a few existing sets contain pictures of Latin Americans, despite the growing attention emotion research is receiving in this region. Here we present the development and validation of the Universidad Nacional de Cordoba, Expresiones de Emociones Faciales (UNCEEF), a Facial Action Coding System (FACS)-verified set of pictures of Argentineans expressing the six basic emotions, plus neutral expressions. FACS scores, recognition rates, Hu scores, and discrimination indices are reported. Evidence of convergent validity was obtained using the Pictures of Facial Affect in an Argentine sample. However, recognition accuracy was greater for UNCEEF. The importance of local sets of emotion pictures is discussed.

  18. Adjective checklist to assess the big five personality factors in the Argentine population. (United States)

    Ledesma, Rubén D; Sánchez, Roberto; Díaz-Lázaro, Carlos M


    The aim of this work was to develop an adjective checklist to assess the Big Five personality factors in the Argentine population. The new instrument was administered to pilot (n= 112), validation (n= 372), and replication (n= 309) samples. The final version of the checklist included 67 adjectives encompassing its 5 dimensions. Factor analysis results were consistent with the Five-factor model. Internal consistency of scales was very good and convergent correlations with the Big Five Inventory (BFI; John, Donahue, & Kentle, 1991) were substantial. Face validity, as evaluated by 2 independent raters, was good. Preliminary evidence of validity for the checklist is presented. Finally, the Adjective Checklist for Personality Assessment and BFI are compared, taking into consideration their psychometric properties in our cultural context. Study limitations and future research are discussed.

  19. Organochlorinated pesticides in the Argentine Antarctic sector and Atlantic coastline waters. (United States)

    García Fernández, J C; Casabella, A N; Marzi, A A; Astolfi, E; Roses, O; Donnewald, H; Villamil, E


    The presence of organochlorinated pesticides in water samples drawn in the Argentine Antarctic Sector and Atlantic coastline has been proved. In general, these samples showed quantities that varied between a few hundredths of a ppmm to slightly more than 1 ppmm, although in some cases and for certain pesticides, depending on the locations, the levels found were definitely higher. With the exception of Dieldrin, which appeared in only one sample/in what would seem to be its course few hundredths of a ppm, to slightly more than 1 ppmm, although in some cases and for certain pesticides found were the same as those reported in previous investigations. The isolated cases of high pesticide contents in water samples drawn at wharves and of snow in the vicinity of Almirante Brown Base show up clearly the influence of human activity on the contamination of the environment.

  20. Therapeutic Argentine tango dancing for people living with Parkinson’s disease: a feasibility study

    Directory of Open Access Journals (Sweden)

    Laura M Blandy


    Full Text Available Background: Individuals living with Parkinson’s disease (PD can experience a range of movement disorders. Therapeutic dance is enjoyable and thought to improve mobility, balance and well being in some people with PD. The primary objective of this study was to evaluate the feasibility and safety of a 4 week Argentine tango dance program for people with PD. Methods: Six community dwelling individuals with mild-moderate PD were recruited from Parkinson’s support groups, movement disorder clinics and the Parkinson’s disease Association in Australia. To minimise falls risk, participants were required to be less than 75 years of age and physically independent (Hoehn and Yahr stages I-III. They were also required to speak English. Participants attended a 1 hour dance class at a dance studio twice per week for 4 weeks. A professional dance instructor led and choreographed the classes. Physiotherapists were present to assist participants during the class and served as dance partners as necessary. The primary outcome was feasibility which was determined by measures of recruitment, adherence, attrition, safety (falls, near misses and adverse events and resource requirements. Secondary measures included the Beck Depression Inventory and the Euroqol-5D, administered at baseline and post intervention. Therapy outcomes pre and post-intervention were analysed descriptively as medians and inter-quartile ranges and using Wilcoxon matched pair signed-rank tests.Results: The Argentine tango dance intervention was shown to be safe, with no adverse events. Adherence to the dance program was 89%. Depression scores improved after intervention (p=0.04. Some challenges were associated with the need to quickly recruitment participants and supplying physiotherapists to act as dance partners. Conclusion: The program was shown to be feasible and safe for people with mild to moderately severe PD.

  1. Culture et propagande franquiste dans l’Argentine péroniste

    Directory of Open Access Journals (Sweden)

    Laurent Bonardi


    Full Text Available La fin de la Seconde Guerre Mondiale et la condamnation internationale de l’Espagne plongent le régime franquiste dans une situation très délicate. Cependant, le gouvernement argentin du général Peron devient un véritable gilet de sauvetage pour la dictature espagnole. Le régime du Caudillo profite de ce contexte pour développer une propagande très intense dans le Rio de la Plata. Pour mener à bien les différentes actions de propagande, les représentants espagnols en Argentine devront lutter contre les activités antifranquistes des exilés.La conclusión de la Segunda Guerra Mundial y la condena internacional de España sumen al régimen franquista en una muy delicada coyuntura. Sin embargo, el gobierno argentino del general Perón se convierte en un auténtico chaleco salvavidas para la dictadura española. El régimen del Caudillo aprovecha este contexto para desarrollar una intensa propaganda en el Río de la Plata. Para llevar a cabo las distintas acciones propagandísticas, los representantes españoles en Argentina tendrán que luchar contra las actividades antifranquistas de los exiliados.The end of World War II and the international condemnation of Spain put Franco’s regime in a very delicate situation. However, the Argentinian government of the general Peron appeared as a “life jacket” for the Spanish dictatorship. The government of the Caudillo used this context to develop a very intense propaganda in the Rio de la Plata. Still, to conclude their various propagandist actions, the Spanish representatives in Argentina had to fight against the activities of antifranquist people in exile.

  2. Consequences of the Argentine ant, Linepithema humile (Mayr), invasion on pollination of Euphorbia characias (L.) (Euphorbiaceae) (United States)

    Blancafort, Xavier; Gómez, Crisanto


    We have studied the influence of the Argentine ant, Linepithema humile, on the pollination of Euphorbia characias, a deciduous insect-pollinated shrub. The observations were made in two adjacent areas (invaded and non-invaded by L. humile) in a Mediterranean cork-oak forest. In the invaded area, L. humile has replaced most of the native ants that climb up this plant's inflorescences. Five native ant species were detected in the non-invaded areas and only one in the invaded area. The number of visitors to infested inflorescences (1.54 ± 1.86 visitors/10 min observation) was lower than in non-infested inflorescences in the invaded area (3.74 ± 4.19 visitors/10'), and in the non-invaded areas (4.16 ± 5.00 visits/10'). For several species of flower-visiting insects, no differences were detected between the time spent in the flowers and the number of flowers visited in the two areas, except for Eristalis tenax, a dipteran which visited more flowers (15.2 ± 11.1 flowers visited/10') and spent more time (9.4 ± 5.8 sec) in the non-invaded area than in the invaded area (7.8 ± 8.2 flowers visited/10' and 5.3 ± 2.1 sec, respectively). The relative representation of insect orders in the two areas was not different. A significant reduction in fruit-set and seed-set was detected in the invaded area. These results suggest that the Argentine ant may greatly affect the reproductive success of components of the Mediterranean flora.

  3. Can the Argentine ant ( Linepithema humile Mayr) replace native ants in myrmecochory? (United States)

    Gómez, Crisanto; Oliveras, Jordi


    We analyse the influence of the Argentine ant ( Linepithema humile Mayr) on the seed dispersal process of the myrmecochorous plants Euphorbia characias, E. biumbellata, Genista linifolia, G. triflora, G. monspessulana and Sarothamnus arboreus. The observations were made in two study plots of Mediterranean cork-oak secondary forest (invaded and non-invaded by L. humile). The presence of L. humile implies the displacement of all native ant species that disperse seeds. Seed transports in the non-invaded zone were carried out by eight ant species. In the invaded zone, L. humile workers removed and transported seeds to the nest. In vertebrate exclusion trials, we observed the same level of seed removal in the invaded and non-invaded zones. Two findings could explain this result. Although mean time to seed localization was higher for native ants (431.7 s) than that for L. humile (150.5 s), the mean proportion of seeds transported after being detected was higher (50.1%) in non-invaded than in invaded (16.8%) zones. The proportion of seeds removed and transported into an ant nest after an ant-seed interaction had dramatically reduced from non-invaded (41.9%) to invaded (7.4%) zones. The levels of seed dispersal by ants found prior to invasion are unlikely to be maintained in invaded zones. However, total replacement of seed dispersal function is possible if contact iteration finally offers similar levels or quantities of seeds reaching the nests. The results obtained confirm that the Argentine ant invasion may affect myrmecochory dramatically in the Mediterranean biome.

  4. Global-scale analyses of chemical ecology and population genetics in the invasive Argentine ant. (United States)

    Brandt, M; Van Wilgenburg, E; Tsutsui, N D


    Ants are some of the most abundant and ecologically successful terrestrial organisms, and invasive ants rank among the most damaging invasive species. The Argentine ant is a particularly well-studied invader, in part because of the extreme social structure of introduced populations, known as unicoloniality. Unicolonial ants form geographically vast supercolonies, within which territorial behaviour and intraspecific aggression are absent. Because the extreme social structure of introduced populations arises from the widespread acceptance of conspecifics, understanding how this colonymate recognition occurs is key to explaining their success as invaders. Here, we present analyses of Argentine ant recognition cues (cuticular hydrocarbons) and population genetic characteristics from 25 sites across four continents and the Hawaiian Islands. By examining both hydrocarbon profiles and microsatellite genotypes in the same individual ants, we show that native and introduced populations differ in several respects. Both individual workers and groups of nestmates in the introduced range possess less diverse chemical profiles than ants in the native range. As previous studies have reported, we also find that introduced populations possess much lower levels of genetic diversity than populations in the native range. Interestingly, the largest supercolonies on several continents are strikingly similar to each other, suggesting that they arose from a shared introduction pathway. This high similarity suggests that these geographically far-flung ants may still recognize and accept each other as colonymates, thus representing distant nodes of a single, widely distributed supercolony. These findings shed light on the behaviour and sociality of these unicolonial invaders, and pose new questions about the history and origins of introduced populations.

  5. Marine fronts are important fishing areas for demersal species at the Argentine Sea (Southwest Atlantic Ocean) (United States)

    Alemany, Daniela; Acha, Eduardo M.; Iribarne, Oscar O.


    The high primary and secondary production associated with frontal systems attract a diversity of organisms due to high prey availability; this is why a strong relationship between fronts and pelagic fisheries has been shown worldwide. In the Argentine Sea, demersal resources are the most important, both in economical and in ecological sense; so we hypothesize that fronts are also preferred fishing areas for demersal resources. We evaluated the relationship between spatial distribution of fishing effort and oceanographic fronts, analyzing three of the most important frontal systems located in the Argentine Sea: the shelf-break front, the southern Patagonia front and the mid-shelf front. Individual vessel satellite monitoring system data (VMS; grouped by fleet type: ice-trawlers, freezer-trawlers and jigging fleet) were studied and fishing events were identified. Fishing events per area were used as a proxy of fishing effort and its spatial distribution by fleet type was visualized and analyzed with Geographic Information Systems. Oceanographic fronts were defined using polygons based on satellite chlorophyll amplitude values, and the percentage of fishing events within each polygon was calculated. Results showed a positive association between fronts and fishing activities of the different fleets, which suggests the aggregation of target species in these zones. The coupling of the freezer-trawler and jigging fleets (that operate on lower trophic level species; Macruronus magellanicus and Illex argentinus respectively) with fronts was higher than the ice-trawler fleet, targeting species of higher trophic level (Merluccius hubbsi). Marine fronts represent important fishing areas, even for demersal resources, as the distribution of fishing fleets and fishing effort are positively associated with frontal zones.

  6. Reactor and method of operation (United States)

    Wheeler, John A.


    A nuclear reactor having a flattened reactor activity curve across the reactor includes fuel extending over a lesser portion of the fuel channels in the central portion of the reactor than in the remainder of the reactor.

  7. Argentina; Argentine

    Energy Technology Data Exchange (ETDEWEB)



    This economical study summarizes the energy situation of Argentina: energy institutions and policy, energy companies (oil, electricity, gas, coal), energy supplies (resources, power production, petroleum, natural gas), prices and tariffs, consumption, economical stakes and perspectives (investments, agreements, projects). Energy data for the 1971-1999 period are summarized in graphs and tables. (J.S.)

  8. Mémoire d’un saccage. Argentine, le hold-up du siècle

    Directory of Open Access Journals (Sweden)

    Julien Welter


    Full Text Available Memoria del saqueo – la oscura trama de la corrupcion Documentaire argentin de Fernando SOLANAS, 2004, 120mn. Sortie de la dictature, l’Argentine ne pensait jamais connaître une nouvelle fois le cauchemar d’un désastre social. Ce pays, naguère le plus riche d’Amérique du Sud, a en effet tout tenté pour s’éloigner des régimes autoritaires conduisant à l’asservissement du peuple. Tout tenté, même l’extrême opposé, l’ultralibéralisme. En revenant sur ces années d’une politique en apparence ouver...

  9. Floral visitation by the Argentine ant reduces pollinator visitation and seed set in the coast barrel cactus, Ferocactus viridescens. (United States)

    LeVan, Katherine E; Hung, Keng-Lou James; McCann, Kyle R; Ludka, John T; Holway, David A


    Mounting evidence indicates that trade-offs between plant defense and reproduction arise not only from resource allocation but also from interactions among mutualists. Indirect costs of plant defense by ants, for example, can outweigh benefits if ants deter pollinators. Plants can dissuade ants from occupying flowers, but such arrangements may break down when novel ant partners infiltrate mutualisms. Here, we examine how floral visitation by ants affects pollination services when the invasive Argentine ant (Linepithema humile) replaces a native ant species in a food-for-protection mutualism with the coast barrel cactus (Ferocactus viridescens), which, like certain other barrel cacti, produces extrafloral nectar. We compared the effects of floral visitation by the Argentine ant with those of the most prevalent native ant species (Crematogaster californica). Compared to C. californica, the Argentine ant was present in higher numbers in flowers. Cactus bees (Diadasia spp.), the key pollinators in this system, spent less time in flowers when cacti were occupied by the Argentine ant compared to when cacti were occupied by C. californica. Presumably as a consequence of decreased duration of floral visits by Diadasia, cacti occupied by L. humile set fewer seeds per fruit and produced fewer seeds overall compared to cacti occupied by C. californica. These data illustrate the importance of mutualist identity in cases where plants balance multiple mutualisms. Moreover, as habitats become increasingly infiltrated by introduced species, the loss of native mutualists and their replacement by non-native species may alter the shape of trade-offs between plant defense and reproduction.

  10. Experimental study on Ra2+ uptake by barite (BaSO{sub 4}). Kinetics of solid solution formation via BaSO{sub 4} dissolution and Ra{sub x}Ba{sub 1-x}SO{sub 4} (re) precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Bosbach, Dirk; Boettle, Melanie; Metz, Volker (Karlsruher Inst. fuer Technologie, Inst fuer Nukleare Entsorgung (INE), Karlsruhe (Germany))


    226Ra2+ and 133Ba2+ uptake by barite in aqueous solution is studied on the basis of batch type experiments with two different barite powders with different specific surface area (0.5 m2/g and 3.2 m2/g, respectively). The uptake of 226Ra2+ and 133Ba2+ is not only limited to adsorption reactions but proceeds significantly into the bulk of the barite crystals. 133Ba2+ uptake kinetics is affected by various parameters, such as amount of sample, specific surface area, sample type and solution composition. In the case of 133Ba2+, complete isotopic equilibration of the 133Ba2+ spiked solution with the barite powder occurs within 50 to 600 days. This information is derived by monitoring the aqueous 133Ba2+ concentration combined with simple mass balance calculations. In the case of 226Ra2+ a Ra{sub x}Ba{sub 1-x}SO{sub 4} solid solution forms and the uptake rate drops significantly within 400 days. The observed 226Ra2+ concentration in solution is controlled by the solubility of a Ra{sub x}Ba{sub 1-x}SO{sub 4} solid solution and several orders of magnitude below the Ra2+ solubility with respect to a pure RaSO{sub 4}(s) end member. It cannot be demonstrated unambiguously that a zero exchange rate and therefore thermodynamic equilibrium has been established within the observation period. The observed concentrations may be interpreted either as (1) a partial equilibration of 20 to 50% of the barite crystals with 226Ra2+ or (2) as complete equilibration of a Ra{sub 0.000128}Ba{sub 0.999872}SO{sub 4} solid solution with 226Ra2+ with no pure barite left. In both cases it is concluded that equilibration between aqueous Ra2+ and barite involves the replacement of a substantial fraction of the initial barite and proceeds significantly beyond pure surface adsorption processes

  11. Perpetuating Social Movements amid Declining Opportunity: The Survival Strategies of Two Argentine Piquetero Groups

    Directory of Open Access Journals (Sweden)

    Edward C. Epstein


    Full Text Available This article examines the recent behaviour in Argentina of two national protest groups of socalled ‘piqueteros’ or picketers (impoverished unemployed individuals who used the blockage of strategic roads and bridges to force government concessions that emerged politically in the buildup to the crisis of 2001-2002. Using theoretical concepts developed by McAdam, Tarrow, and Tilly in understanding social movements, the author analyses what he calls the ‘survival strategy’ adopted by their leaders as the political opportunities that produced their initial growth gave way to a more hostile environment with the normalization of Argentine politics under the Kirchner administration. While the two piquetero groups studied differ considerably in terms of their politics and ideology, both ended up depending on the same traditional tactic of utilizing important government contacts to obtain the resources necessary for organizational maintenance, despite their nominal identity as radical protesters against the present political system.Resumen: Perpetuando movimientos sociales y oportunidades decrecientes: las estrategias de sobrevivencia de dos grupos de piqueteros argentinesEste artículo examina el comportamiento reciente de dos grupos nacionales de protesta argentinos llamados ‘piqueteros’ (desempleados empobrecidos que usaron el bloqueo de calles y puentes estratégicos para forzar concesiones gubernamentales que aparecieron durante la crisis de 2001- 2002. Utilizando conceptos teóricos creados por McAdam, Tarrow, y Tilly en su discusión sobre los movimientos sociales, el autor analiza lo que describe como ‘estrategias de sobrevivencia’ adoptadas por sus dirigentes cuando las oportunidades que ocasionaron su crecimiento inicial cedieron ante un ambiente más hostil en el contexto de la normalización de la política argentina durante la administración de Kirchner. Aunque los dos grupos piqueteros estudiados se diferencian mucho en t

  12. Reactor Physics Programme

    Energy Technology Data Exchange (ETDEWEB)

    De Raedt, C


    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.

  13. [Prevalence of hepatitis C antibodies in plasma donors for the treatment of Argentine hemorrhagic fever]. (United States)

    Saavedra, M C; Briggiler, A M; Enría, D; Riera, L; Ambrosio, A M


    For Argentine Hemorrhagic Fever, a disease caused by Junin virus (JV), there is an effective treatment, consisting of the transfusion of immune plasma (IP). This plasma is obtained from individuals who have had the disease. Since Hepatitis C virus (HCV) is transmitted parenterally, this study was aimed to estimate the prevalence of anti-HCV in a population of IP donors. In this study, 376 donors (47 females and 329 males) were studied: 95 individuals (24 females and 71 males) who had had FHA but had not received treatment and 88 laboratory workers (57 females and 31 males) who were included as controls. Serum samples were tested by EIA (Abbott, Germany) for HCV, and later confirmed by LIATEK (Organon, Ireland). Antibodies to HCV were detected in 29/376 donors (7.7%), in only 1/95 (1.0%) untreated convalescents of AHF and in 1/ 88 (1.1%) of laboratory workers. Retrospective analysis of the seroconversion for HCV in these individuals demonstrated that in 16/24 donors (66.6%) the infection by HCV was probably associated with the IP transfusion. The data presented herein show how the infection with HCV was disseminated among donors of IP, stressing the risk associated to transfusional practices, and emphasizing the need of vaccination to prevent AHF and also the risk inherent to its treatment.

  14. Moessbauer and magnetic studies of parent material from argentine pampas soils

    Energy Technology Data Exchange (ETDEWEB)

    Bidegain, J. C. [Laboratorio de Entrenamiento Multidisciplinario para la Investigacion Tecnologica (Argentina); Bartel, A. A. [Universidad Nacional de La Pampa, Facultad de Ciencias Exactas y Naturales (Argentina); Sives, F. R.; Mercader, R. C., E-mail: [Universidad Nacional de La Plata, Departamento de Fisica, Facultad de Ciencias Exactas (Argentina)


    In order to establish a correlation between the different types of soils using hyperfine and magnetic parameters as climatic and environmental proxies, we have studied the differentiation of soil developed around 38.5{sup o} south latitude, in the central Pampas of Argentina, by means of Moessbauer spectroscopy and environmental magnetism. The soils transect (climosequence) investigated stretches from the drier west (around 64{sup o} W) to the more humid east (at around 59{sup o} W) in the Buenos Aires Province, covering a distance of 600 km. The soils studied developed during recent Holocene geologic times in a landscape characterized by small relict plateaus, slopes and depressions, dunes and prairies. The parent material consists of eolian sandy silts overlying calcrete layers. The low mean annual precipitation in the western parts of the region gives rise to soils without B-horizons, which limits the agricultural use of land. The preliminary results show an increase of the paramagnetic Fe{sup 3+} relative concentration from west to east in the soils investigated. Magnetite is probably mainly responsible for the observed enhancement in the susceptibility values. The magnetic response of the parent material is similar to that of the loess part of the previously investigated loess-paleosol sequences of the Argentine loess plateau.

  15. Characteristics of pica practice during pregnancy in a sample of Argentine women. (United States)

    López, L B; Marigual, M; Martín, N; Mallorga, M; Villagrán, E; Zadorozne, M E; Martín De Portela, M L P; Ortega Soler, C R


    The purpose of this study was to describe the practice of pica during pregnancy in Argentine women. Maternal and fetal characteristics as well as the practice of pica were evaluated during the puerperium in a sample of 1,014 women from five different geographical areas. Pica prevalence for the total sample was 23.2% (95% CI 20.6-25.8). Pagophagia (ice consumption) was the main type of pica practice, followed by geophagia (earth intake) and the ingestion of soap, toothpaste and chalk. The onset of the practice was mainly in the first months of pregnancy. A total of 49.8% of women revealed a family history of pica; 30.6% had pica in childhood and 13.2% suffered from polypica. Women with pica during pregnancy had similar age, pre-pregnancy body mass index (BMI), parity, neonatal birth weight and gestational age compared with non-pica mothers, although maternal haemoglobin concentration was lower in women with pica than in non-pica mothers (p = 0.0001).

  16. Les intellectuels espagnols exilés dans l'Argentine peroniste

    Directory of Open Access Journals (Sweden)

    Laurent Bonardi


    Full Text Available El gobierno argentino del general Perón reveló ser un verdadero chaleco salvavidas para la dictadura española. Esta política de cooperación provoca una viva oposición en Argentina. Este trabajo propone un análisis de las reacciones de los intelectuales españoles exiliados en Argentina. Observaremos de que manera los intelectuales españoles lucharon contra la dictadura franquista durante el idilio hispano-argentino y analizaremos el “modus operandi” adoptado por el gobierno peronista para obstaculizar las actividades anti-franquistas en el exilio.__________________ABSTRACT:The Argentine government of general Perón becomes an authentic life jacket for the Spanish dictatorship. This policy of cooperation triggers ample dispproval in Argentina. We propose an analysis of the reactions of the spanish intellectuals exiled in Argentina. We will see how the Spanish intellectuals fight against the Franco dictatorship during the honeymoon Hispanic-Argentinean. Also we will analyze the modus operandi adopted by the Peronist government to prevent the antifrancoist activities of the exiliados.

  17. Les variations glaciaires dans les Andes de Mendoza (Argentine entre 1975 et 2007

    Directory of Open Access Journals (Sweden)

    Étienne Cossart


    Full Text Available Le suivi des glaciers constitue un enjeu essentiel pour l’organisation des sociétés et le fonctionnement des milieux montagnards. Dans la mesure où les glaciers influencent fortement le régime des cours d’eau, et donc les stratégies d’irrigation, leur disparition peut remettre en cause de nombreux usages liés à l’eau. Or, si nombre de glaciers sont étudiés individuellement, des méthodes permettant d’effectuer des suivis de l’englacement à l’échelle régionale manquent. Nous proposons donc ici une méthode, fondée sur la reconstitution de champs d’altitudes de la Ligne d’Équilibre Glaciaire, aboutissant à la réalisation de cartes diachroniques régionales. Nous synthétisons ainsi les variations glaciaires depuis 30 ans sur l’ensemble d’un secteur de plusieurs milliers de kilomètres carr��s : les Andes de Mendoza (Argentine.

  18. Activity of bifenthrin, chlorfenapyr, fipronil, and thiamethoxam against Argentine ants (Hymenoptera: Formicidae). (United States)

    Wiltz, B A; Suiter, D R; Gardner, W A


    Bifenthrin, chlorfenapyr, fipronil, and thiamethoxam were evaluated for activity against the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae). Mobility impairment and lethal times were determined after topical treatments. Ants were immobilized most quickly by bifenthrin, followed by chlorfenapyr and thiamethoxam. After 2 h, the number of fipronil-treated ants unable to walk out of test arenas did not differ from control ants. Median lethal time (LT50) after topical treatment was lowest in the bifenthrin treatment, followed by thiamethoxam, chlorfenapyr, and then fipronil. Mortality due to horizontal exposure was evaluated at 10, 20, or 30 degrees C, with topically treated ant corpses serving as donors. There was low to moderate horizontal activity in bifenthrin and chlorfenapyr treatments, with no temperature effect in bifenthrin treatments and a positive temperature effect in chlorfenapyr treatments. Mortality in the fipronil treatments was highest and was positively correlated with temperature. Thiamethoxam treatments did not differ from controls at 10 degrees C, but mortality increased with temperature. To evaluate contact activity, either all of 20% of the ants in a cohort were exposed to insecticide-treated pine needles. In both tests, mortality was highest in fipronil and bifenthrin treatments, followed by thiamethoxam, with lowest mortality in chlorfenapyr treatments. Effectiveness as a barrier was evaluated by providing a choice between bridges treated with insecticide or water. Although bifenthrin did not provide an impenetrable barrier, it was the only treatment having fewer ants than its paired control. Mortality data suggest that lack of recruitment rather than repellency account for this result.

  19. Impact of CPS1 Gene rs7422339 Polymorphism in Argentine Patients With Hyperhomocysteinemia

    Directory of Open Access Journals (Sweden)

    Silene M. Silvera-Ruiz BSc


    Full Text Available Carbamoyl phosphate synthetase 1 (CPS1 is a key gene in the first step of urea cycle and has been correlated with nitric oxide level and vascular smooth muscle activity. A functional single-nucleotide polymorphism C/A at position 4217 in CPS1 (National Center for Biotechnology Information SNP database no. rs7422339, T1405N was reported to be associated with high homocysteine (Hcy plasma values. Although genetic variants of methylenetetrahydrofolate reductase (MTHFR gene are known to influence Hcy concentration, other genetic determinants of Hcy remain largely unknown. The association between the CPS1 rs7422339 and the risk of hyperhomocysteinemia in Latin American populations is unknown. Here, we study this association in 100 patients having hyperhomocysteinemia without MTHFR c.677C>T polymorphism and 100 controls. CPS1 rs7422339 was studied using polymerase chain reaction and enzymatic restriction. Comparisons of the CPS1 rs7422339 genotype distributions revealed a significant difference between groups (P = 2.3 × 10−3. Patients carrying polymorphic allele showed almost 3 times higher risk (odds ratio [OR] = 2.47 of hyperhomocysteinemia than wild-type allele, suggesting that rs7422339 SNP is associated with high Hcy levels in the Argentine population.

  20. Urban Infestation Patterns of Argentine Ants, Linepithema humile, in Los Angeles

    Directory of Open Access Journals (Sweden)

    Smadar Gilboa


    Full Text Available Infestations of buildings by Argentine ants, Linepithema humile (Mayr, were monitored on the campus of the University of California, Los Angeles. Foraging ant activity peaked during the hotter months of the year. The mean monthly maximum temperature, but not rainfall, positively correlated with indoor infestation frequency. Neither garden size nor the predominant groundcover vegetation correlated with the number of foraging ants at baits within gardens. Although the number of foraging ants outside a building varied over 40-fold, ant density in gardens did not predict the likelihood of infestation within the building. Also, the type of vegetative groundcover employed did not predict infestation frequency. There was, however, a significant negative relationship between the size of the garden outside of a building and the number of infestations. Given the large foraging area of L. humile workers, buildings next to small gardens may be infested simply because they lie within the “normal” foraging area of a colony. The best predictor of which rooms were infested within buildings was the presence of a water source. Thus providing water for ant colonies outside and away from buildings may be one method of integrated pest management to reduce the proclivity of ants to infest structures.

  1. Lithologic identification and characterization using ETM+ (Landsat 7. Study case of the Upsala glacier basin, Argentine

    Directory of Open Access Journals (Sweden)

    A. Lo Vecchio


    Full Text Available The object of this study aims to evaluate and analyze digital image processing techniques applied to the Enhanced Thematic Mapper Plus (ETM+, in order to demark and characterize the outcropping lithologies on the Upsala Glacier basin, Santa Cruz, Argentine Republic. The prolific technological and spatial development experienced in the last decades has given place to the generation, without precedents, of multiple remote sensors capable of capturing information of the terrestrial surface and also the improvement of digital image processing techniques and software; amongst them, the amazing possibilities in the detection and differentiation of diverse covers present on the terrestrial surface can be highlighted, such as glaciers, volcanoes, vegetation, soils, water, types of rock outcrops, etc. This situation improves mapping and monitoring of natural phenomenon in the Earth Sciences field. The proposed methodology includes radiometric corrections, elimination of unwanted covers, statistical evaluation in the combination of the most appropriate bands, application of the Z index, discretization of the statistical series, entailing tasks of spectral classification with field samples and a later validation. Valuable results were obtained by means of digital processing of images, that were validated yielding a 82% of accuracy in the proposed classification, which are good results taking into account the diversity of covers present and the lithological heterogeneity that makes up each pixel (30m. These results were also validated with existing geological maps, obtaining a good agreement.

  2. Inhibition of cyclooxygenase activity by standardized hydroalcoholic extracts of four Asteraceae species from the Argentine Puna

    Directory of Open Access Journals (Sweden)

    M.R. Alberto


    Full Text Available We determined the anti-inflammatory activity of standardized extracts of four medicinal plant species (Baccharis incarum, B. boliviensis, Chuquiraga atacamensis, Parastrephia lucida that grow in the Argentine Puna (3800 m above sea level and that are used to reduce oxidative stress and alleviate gout and arthritic pain. The extracts of plant aerial parts were standardized in terms of total phenolic compounds and flavone/flavanone content and free radical scavenging activity. All extracts showed high phenolic compound concentration (0.5-1.6 mg/mL, mainly flavones and flavonols (0.1-0.8 mg/mL. The extracts showed hydrogen donating ability (DPPH and ABTS and reactive oxygen species scavenging activity (O2●-, OH-, H2O2. The ability of the extracts to inhibit cyclooxygenase enzymes (COX-1 and COX-2 was determined by calculating percent inhibition of PGE2 production measured by enzyme immunoassay. All extracts inhibited both enzymes with IC50 values of 2.0 to 16.7 µg/mL. The anti-inflammatory activity of B. incarum and C. atacamensis extracts was higher than that of B. boliviensis and P. lucida. The IC50 values obtained for indomethacin were 0.11 and 0.78 µM for COX-1 and COX-2, respectively. The present results are consistent with the anecdotal use of these species in phytotherapic preparations.

  3. Inhibition of cyclooxygenase activity by standardized hydroalcoholic extracts of four Asteraceae species from the Argentine Puna. (United States)

    Alberto, M R; Zampini, I C; Isla, M I


    We determined the anti-inflammatory activity of standardized extracts of four medicinal plant species (Baccharis incarum, B. boliviensis, Chuquiraga atacamensis, Parastrephia lucida) that grow in the Argentine Puna (3800 m above sea level) and that are used to reduce oxidative stress and alleviate gout and arthritic pain. The extracts of plant aerial parts were standardized in terms of total phenolic compounds and flavone/flavanone content and free radical scavenging activity. All extracts showed high phenolic compound concentration (0.5-1.6 mg/mL), mainly flavones and flavonols (0.1-0.8 mg/mL). The extracts showed hydrogen donating ability (DPPH and ABTS) and reactive oxygen species scavenging activity (O2-, OH-, H2O2). The ability of the extracts to inhibit cyclooxygenase enzymes (COX-1 and COX-2) was determined by calculating percent inhibition of PGE2 production measured by enzyme immunoassay. All extracts inhibited both enzymes with IC50 values of 2.0 to 16.7 microg/mL. The anti-inflammatory activity of B. incarum and C. atacamensis extracts was higher than that of B. boliviensis and P. lucida. The IC50 values obtained for indomethacin were 0.11 and 0.78 microM for COX-1 and COX-2, respectively. The present results are consistent with the anecdotal use of these species in phytotherapic preparations.

  4. Chromosomal variation in Argentine populations of Akodon montensis Thomas, 1913 (Rodentia, Cricetidae, Sigmodontinae). (United States)

    Malleret, Matías Maximiliano; Labaroni, Carolina Alicia; García, Gabriela Verónica; Ferro, Juan Martín; Martí, Dardo Andrea; Lanzone, Cecilia


    The genus Akodon Meyen, 1833 is one of the most species-rich among sigmodontine rodents and has great chromosome variability. Akodon montensis has a relatively broad distribution in South America, and Argentine populations are located in the southernmost region of its range. Brazilian populations have important chromosomal variability, but cytogenetic data from Argentina are scarce. We performed a chromosome characterization of natural populations of Akodon montensis using conventional staining, C-banding, Ag-NORs and base-specific fluorochromes. A total of 31 specimens from five localities of Misiones Province, in Argentina, were analyzed. The 2n=24 chromosomes was the most frequently observed karyotype. However, five individuals presented 25 chromosomes due to a supernumerary B-chromosome; and one individual had 2n=26 due to one B plus a trisomy for chromosome 11. Additionally, two XY females and two variants of the X chromosomes were found. C-positive centromeric bands occurred in all chromosomes; additional C-bands were observed in some autosomes, the X, Y and B chromosomes. Ag-NORs were observed in five autosomes, and the B chromosome was frequently marked. Fluorochrome banding was similar among karyotypes of the analyzed populations. Comparisons of cytogenetic data among populations of Argentina and Brazil showed the presence of high intraspecific variability in Akodon montensis and some differences among regions.

  5. Myxozoans as biological tags for stock identification of the Argentine hake, Merluccius hubbsi (Gadiformes: Merlucciidae). (United States)

    Cantatore, D M P; Irigoitia, M M; Holzer, A S; Timi, J T


    Myxozoans have been successfully used as tags for fish stock identification around the world. However, few studies using myxozoan tags have been carried out in the Southern Atlantic, a region with complex oceanography that constitutes a potentially suitable scenario for testing the utility of myxozoans as indicators. Its usefulness was tested using six samples of Merluccius hubbsi in two different regions of the Argentine Sea. Generalized linear models were performed to assess the effects of fish size and sex, and year and region of capture and selected using the Information Theoretic approach. Three myxozoan species were recorded: Kudoa rosenbuschi, Myxoproteus meridionalis and Fabespora sp. Results of modelling species individually showed differential capabilities for detecting geographical population structure at different spatial scales, with K. rosenbuschi and Fabespora sp. allowing the discrimination of northern and southern stocks, but Fabespora sp. also as a promissory indicator of intrapopulation sub-structure due to different migratory routes during non-reproductive periods. This work confirms that myxozoans offer a set of suitable markers at different spatial scales, which can be selected individually or in any combination, depending on the geographical extent of the study, constituting tools adaptable to the objectives of further research on fish population structure.

  6. Screening of FSH receptor gene in Argentine women with premature ovarian failure (POF). (United States)

    Sundblad, Victoria; Chiauzzi, Violeta A; Escobar, Maria Eugenia; Dain, Liliana; Charreau, Eduardo H


    Diverse mutations in FSH-receptor (FSHR) gene have been described as possible cause of premature ovarian failure (POF). To investigate the presence of mutations and/or polymorphisms in FSHR gene, DNA from 20 POF, 5 of which were diagnosed as resistant ovary syndrome (ROS), and from 44 controls was isolated from peripheral lymphocytes. The complete coding sequence was analysed by PCR followed by SSCP, direct sequencing or restriction enzyme analysis. No mutations in FSHR gene were identified in the patients studied. The two already described polymorphisms in exon 10, A919G and A2039G, cosegregated in all the homozygous individuals, indicating that FSHR presents two isoforms: Ala307-Ser680 and Thr307-Asn680. OR results suggest that the 919G-2039G allelic variant or the homozygous genotype is not associated to disease risk. In addition, a heterozygous substitution T1022C (Val341Ala) was found in two control subjects. We suggest that mutations in FSHR gene are rare in women with POF in Argentine. Presence of a particular FSHR isoform does not appear to be associated with this disease.

  7. Magnetic and Moessbauer Studies of Quaternary Argentine Loessic Soils and Paleosols

    Energy Technology Data Exchange (ETDEWEB)

    Mercader, R. C., E-mail:; Sives, F. R. [Universidad Nacional de La Plata, Departamento de Fisica, IFLP, Facultad de Ciencias Exactas (Argentina); Imbellone, P. A. [Universidad Nacional de La Plata, Instituto de Geomorfologia y Suelos (Argentina); Vandenberghe, R. E. [Ghent University, NUMAT, Department of Subatomic and Radiation Physics (Belgium)


    This paper is a review of the current status about the remaining problems that are found in the investigation of the Quaternary Argentine soils and loessic sediments, and the way that Moessbauer studies can assist in solving them. There are two main types of investigations that make use of the magnetic response of the samples to correlate them with information gathered by other methods. On the one hand, there is the stratigraphic and chronological research, which is of importance from the geological and paleontological points of view. On the other hand, the paleoclimatic records, of significance toward a possible model of the past climate, are also studied because of their close relation to the sediments history. However, there is not yet a model that can tell the difference between the modifications due to the climatic conditions at the time when the soils were buried from processes that occurred after burial. Some examples are given that show that Moessbauer studies can be applied with a certain degree of success when cross-checked with magnetic measurements toward understanding the processes that occurred in alluvial B (paleosols) and C horizons (loess) from the eastern part of Buenos Aires Province. Although the application of Moessbauer studies to hydromorphic processes in soils is not straightforward, there are cases in which Moessbauer spectroscopy, if applied properly and correlated with other techniques, is able to characterize the type of iron oxides existing in the materials and thus assist theories about its origin and history.

  8. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Hiroto


    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.).

  9. Light water reactor safety

    CERN Document Server

    Pershagen, B


    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

  10. Nuclear reactor physics

    CERN Document Server

    Stacey, Weston M


    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

  11. Spinning fluids reactor (United States)

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


    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.

  12. Tulio Halperin Donghi, Révolution et guerre. Formation d’une élite dirigeante dans l’Argentine Créole



    Difficile de mesurer l’événement que constitue la récente traduction de Revolución y guerra de l’historien Argentin Tulio Halperin Donghi pour les sciences humaines francophones. Plus de quarante ans après sa publication initiale aux éditions Siglo XXI et de la parution française de son Histoire Contemporaine de l’Amérique latine, la sortie de l’un des plus grands classiques de l’historiographie argentine est en effet une entreprise éditoriale qu’il faut grandement saluer. Nous tenterons de l...

  13. TDT in Argentine and Chile: dynamics of power in the process of adoption of the technological standard ISDB-TB

    Directory of Open Access Journals (Sweden)



    Full Text Available The article analyses the media policymaking process about the adoption of the technological standard for the digital terrestrial television in Argentine and Chile. The explorative and descriptive study inquires about the tensions, articulations and dynamics of the national and supranational parties (State, broadcasters, lobbies of technical standards and civil society that played in the politic process from the late 90s when the issue of digital television inserted into public agenda until August/September on 2009 when both countries adopted the Japanese- Brazilian technology system.

  14. 15 June 2009 - President of the Argentine Nation C. Fernández visiting ATLAS experimental area.

    CERN Multimedia

    Maximilien Brice


    Tirage 1:President of the Argentine Nation, C. Fernández and Minister of Science, Technology and Innovative Production,L. Barañao Tirage 2-8:Arrival greetings Tirage 9-12:Introduction to CERN's activities by Director-General, R. Heuer Tirage 13-15:Signature of the guest book Tirage 16-25:M. Benedetti,R. Heuer and L.Barañao sit for the signature of the Agreement Tirage 26-33: Meeting with Argentinian scientists at CERN

  15. Figurations of Islandness in Argentine Culture and Literature: Macedonio Fernández, Leopoldo Marechal, and César Aira

    Directory of Open Access Journals (Sweden)

    Norman Cheadle


    Full Text Available This article explores islandness in the River Plate imaginary. Two modern foundational “island texts” – Thomas More’s Utopia and Daniel Defoe’s Robinson Crusoe – have exerted a formative influence on the Spanish-American colonial imagination, an influence inflected by the particular historical experience of the River Plate region and its dominant city, Buenos Aires. The figuration of islandness is examined in three twentieth-century Argentine novels by Macedonio Fernández, Leopoldo Marechal, and César Aira. The article finds both continuity and evolution in the images of islandness in these novels.

  16. The Argentine Impact Record: Implications for Episodes of Increased Flux during the Last 10 Myr (United States)

    Harris, R. S.; Schultz, P. H.


    Schultz et al. [1-6] have identified 8 impact melt breccia deposits in late Cenozoic strata of the Argentine Pampas. 40Ar/39Ar and fission track dating, combined with sequence and biostratigraphic controls, demonstrate that they represent separate events between 9.24 Ma and 6 ka. These ejecta contain shocked minerals and excavated basement clasts indicative of crater-forming events rather than air blasts. If each involved iron bolides ≤ 50 m across, 8 impacts over ~1.1 x 106 km2 in 10 Myr does not represent an anomaly. However, the melt volumes and distributions observed suggest at least half of the collisions were much larger. One event close to the Miocene-Pliocene boundary (5.28 Ma) appears to have spread microtektites as far as the South Tasman Rise. And three deposits contain meteoritic debris linked to stony and stony-iron asteroids (including HED and angrite-like material) [6,7]. Consequently, one or more increases in the impact flux since the mid-Miocene may be required to account for the Argentine record [8]. Farley et al. [9,10] propose that the disruption of a large main-belt asteroid 8.3 Ma increased the IDP flux in the inner solar system leading to a positive 3He anomaly in late Miocene (~6.8-8.3 Ma) sediments. The anomaly is comparable to the late Eocene (~34.2-36.4 Ma) 3He enhancement attributed to a comet [11] or asteroid [12] shower, which increased both the abundance of IDPs and large asteroids reaching the surface. But Farley et al. discount such a scenario in the late Miocene based on a perceived absence of coincident crater-forming impacts. Preserved ejecta and geochemical signatures, however, indicate the contrary. We suggest that the late Miocene contains at least as rich a record of terrestrial impacts as the late Eocene. The patterns of elevated 3He, main-belt breakups, and significant impact events are very similar through both intervals. Two reported asteroid breakups during the Pliocene and mid-Pleistocene [13,14] also appear to

  17. 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


    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.

  18. Practical Pest Management Strategies to Reduce Pesticide Runoff for Argentine Ant (Hymenoptera: Formicidae) Control. (United States)

    Greenberg, Les; Rust, Michael K; Richards, Jaben; Wu, Xiaoqin; Kabashima, John; Wilen, Cheryl; Gan, Jay; Choe, Dong-Hwan


    The purpose of this study was to involve pest management professionals in the design of application techniques and strategies that would be efficacious and also reduce insecticide runoff. Our study involved measuring both the efficacy of treatments for the Argentine ant, Linepithema humile (Mayr), and the concurrent runoff of fipronil and pyrethroids. Two collaborating companies used low-impact protocols for controlling ants while minimizing runoff. Protocol 1 involved bimonthly treatments, while Protocol 2 was monthly. Both protocols involved an initial treatment with a fipronil spray around the foundation. At the garage door-driveway interface, the fipronil application was done as a pin stream for Protocol 1, and as a crack and crevice application in the expansion joint near the garage for Protocol 2. Protocol 1 replaced most pyrethroid sprays with bifenthrin granules placed around bushes and away from the driveway. For the next treatment on day 63, Protocol 1 also included cyfluthrin spray treatments around the house foundation and crack and crevice applications around the edge of the driveway. For the first treatment in Protocol 2, the fipronil spray was supplemented with spot treatments of cyfluthrin. For subsequent Protocol 2 treatments, botanical insecticides were applied. For weeks 1 and 2 posttreatment combined, Protocol 1 had significantly higher reductions in ant numbers compared with Protocol 2. Thereafter there were no significant differences between the protocols. Runoff of bifenthrin from the granules used with Protocol 1 was much lower than in previous trials involving bifenthrin sprays. Day 1 fipronil runoff for Protocol 2 was significantly lower than that for Protocol 1. This difference may be because of the crack and crevice application applied in Protocol 2. Cyfluthrin runoff was minimal for Protocol 2, which involved spot treatments to supplement the fipronil on day 1, or the botanical insecticides for subsequent treatments. Protocol 1 had a

  19. Suspending the next turn as a form of repair initiation: evidence from Argentine Sign Language

    Directory of Open Access Journals (Sweden)

    Elizabeth eManrique


    Full Text Available Practices of other-initiated repair deal with problems of hearing or understanding what another person has said in the fast-moving turn-by-turn flow of conversation. As such, other-initiated repair plays a fundamental role in the maintenance of intersubjectivity in social interaction. This study finds and analyses a special type of other-initiated repair that is used in turn-by-turn conversation in a sign language: Argentine Sign Language (Lengua de Señas Argentina or LSA. We describe a type of response termed a ‘freeze-look’, which occurs when a person has just been asked a direct question: instead of answering the question in the next turn position, the person holds still while looking directly at the questioner. In these cases it is clear that the person is aware of having just been addressed and is not otherwise accounting for their delay in responding (e.g., by displaying a ‘thinking’ face or hesitation, etc.. We find that this behavior functions as a way for an addressee to initiate repair by the person who asked the question. The ‘freeze-look’ results in the questioner ‘re-doing’ their action of asking a question, for example by repeating or rephrasing it. Thus we argue that the ‘freeze-look’ is a practice for other-initiation of repair. In addition, we argue that it is an ‘off-record’ practice, thus contrasting with known on-record practices such as saying ‘Huh?’ or equivalents. The findings aim to contribute to research on human understanding in everyday turn-by-turn conversation by looking at an understudied sign language, with possible implications for our understanding of visual bodily communication in spoken languages as well.

  20. Suspending the next turn as a form of repair initiation: evidence from Argentine Sign Language. (United States)

    Manrique, Elizabeth; Enfield, N J


    Practices of other-initiated repair deal with problems of hearing or understanding what another person has said in the fast-moving turn-by-turn flow of conversation. As such, other-initiated repair plays a fundamental role in the maintenance of intersubjectivity in social interaction. This study finds and analyses a special type of other-initiated repair that is used in turn-by-turn conversation in a sign language: Argentine Sign Language (Lengua de Señas Argentina or LSA). We describe a type of response termed a "freeze-look," which occurs when a person has just been asked a direct question: instead of answering the question in the next turn position, the person holds still while looking directly at the questioner. In these cases it is clear that the person is aware of having just been addressed and is not otherwise accounting for their delay in responding (e.g., by displaying a "thinking" face or hesitation, etc.). We find that this behavior functions as a way for an addressee to initiate repair by the person who asked the question. The "freeze-look" results in the questioner "re-doing" their action of asking a question, for example by repeating or rephrasing it. Thus, we argue that the "freeze-look" is a practice for other-initiation of repair. In addition, we argue that it is an "off-record" practice, thus contrasting with known on-record practices such as saying "Huh?" or equivalents. The findings aim to contribute to research on human understanding in everyday turn-by-turn conversation by looking at an understudied sign language, with possible implications for our understanding of visual bodily communication in spoken languages as well.

  1. SNTP program reactor design (United States)

    Walton, Lewis A.; Sapyta, Joseph J.


    The Space Nuclear Thermal Propulsion (SNTP) program is evaluating the feasibility of a particle bed reactor for a high-performance nuclear thermal rocket engine. Reactors operating between 500 MW and 2,000 MW will produce engine thrusts ranging from 20,000 pounds to 80,000 pounds. The optimum reactor arrangement depends on the power level desired and the intended application. The key components of the reactor have been developed and are being tested. Flow-to-power matching considerations dominate the thermal-hydraulic design of the reactor. Optimal propellant management during decay heat cooling requires a three-pronged approach. Adequate computational methods exist to perform the neutronics analysis of the reactor core. These methods have been benchmarked to critical experiment data.

  2. Fast Spectrum Reactors

    CERN Document Server

    Todd, Donald; Tsvetkov, Pavel


    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...

  3. Hybrid reactors. [Fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Moir, R.W.


    The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of /sup 233/U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW.m/sup -2/, and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are usually rapid.

  4. Validation of the Argentine version of the Memory Binding Test (MBT for Early Detection of Mild Cognitive Impairment

    Directory of Open Access Journals (Sweden)

    Fabian Roman

    Full Text Available ABSTRACT Background: "Forgetfulness" is frequent in normal aging and characteristic of the early stages of dementia syndromes. The episodic memory test is central for detecting amnestic mild cognitive impairment (MCI. The Memory Binding Test (MBT is a simple, easy and brief memory test to detect the early stage of episodic memory impairment. Objective: To validate the Argentine version of the MBT in a Latin American population and to estimate the diagnostic accuracy as a tool for early detection of MCI. Methods: 88 subjects (46 healthy controls and 42 patients with amnestic MCI matched for age and educational level were evaluated by an extensive neuropsychological battery and the memory binding test. Results: A significantly better performance was detected in the control group; all MBT scales were predictive of MCI diagnosis (p<.01. The MBT showed high sensitivity (69% and high specificity (88%, with a PPV of 93% and a NPV of 55% for associative paired recall. A statistically significant difference (c2=14,164, p<.001 was obtained when comparing the area under the curve (AUC of the MBT (0.88 and the MMSE (0.70. Conclusion: The Argentine version of the MBT correlated significantly with the MMSE and the memory battery and is a useful tool in the detection of MCI. The operating characteristics of the MBT are well suited, surpassing other tests commonly used for detecting MCI.

  5. Multi purpose research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Raina, V.K. [Research Reactor Design and Projects Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)]. E-mail:; Sasidharan, K. [Research Reactor Design and Projects Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Sengupta, Samiran [Research Reactor Design and Projects Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Singh, Tej [Research Reactor Services Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)


    At present Dhruva and Cirus reactors provide the majority of research reactor based facilities to cater to the various needs of a vast pool of researchers in the field of material sciences, physics, chemistry, bio sciences, research and development work for nuclear power plants and production of radio isotopes. With a view to further consolidate and expand the scope of research and development in nuclear and allied sciences, a new 20 MWt multi purpose research reactor is being designed. This paper describes some of the design features and safety aspects of this reactor.

  6. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kanbe, Mitsuru


    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.)

  7. Hydroacoustical evidence of the expansion of pelagic swarms of Munida gregaria (Decapoda, Munididae) in the Beagle Channel and the Argentine Patagonian Shelf, and its relationship with habitat features (United States)

    Diez, Mariano J.; Cabreira, Ariel G.; Madirolas, Adrián; Lovrich, Gustavo A.


    Squat lobsters are highly diversified and widespread decapods, of which only three species form pelagic swarms. Here we infer the expansion of Munida gregaria populations in the Beagle Channel and the Argentine Patagonian Shelf by means of acoustic surveys of pelagic swarms. We also describe the habitat characteristics in which these swarms occur. Acoustic data was collected during three multidisciplinary scientific cruises on board of the R/V Puerto Deseado during 2009, 2012 and 2014. Despite differences in the environmental conditions between the two surveyed areas, between 2009 and 2014 pelagic swarms increased their occurrence and abundance both in the Beagle Channel and on the Argentine Patagonian Shelf. Towards the end of the studied period, pelagic swarms of M. gregaria occurred in new locations, supporting the notion of a population expansion. Within the Beagle Channel swarm expansions were more marked than on the Patagonian Shelf. We here postulate that M. gregaria expansions occur in association with productive areas of the Argentine continental shelf, such as frontal zones, favoured by the squat lobster phenotypic plasticity that permit to exploit resources in both the neritic and benthic environments. At a regional scale on the Patagonian Shelf, three main groups of pelagic swarms of M. gregaria were clearly associated to respective frontal zones. The information presented here is necessary to understand fluctuations in both distribution and abundance patterns of a key species on the Argentine continental shelf. These fluctuations could be direct or indirect indicators of changes in the ecosystem.

  8. Large-Scale Agricultural Management and Soil Meso- and Macrofauna Conservation in the Argentine Pampas

    Directory of Open Access Journals (Sweden)

    José Camilo Bedano


    Full Text Available Soil is the most basic resource for sustainable agricultural production; it promotes water quality, is a key component of the biogeochemical cycles and hosts a huge diversity of organisms. However, we are not paying enough attention to soil degradation produced by land use. Modern agriculture has been successful in increasing yields but has also caused extensive environmental damage, particularly soil degradation. In the Argentine Pampas, agriculturization reached a peak with the generalized use of the no-till technological package: genetically modified soybeans tolerant to glyphosate, no-till, glyphosate, and inorganic fertilizers. This phenomenon has been widely spread in the country; the no-till package has been applied in large areas and has been used by tenants in a 60%–70% of cultivated lands. Thus, those who were involved in developing management practices may not be the same as those who will face degradation issues related to those practices. Indeed, most evidence reviewed in this paper suggests that the most widely distributed practices in the Pampas region are actually producing severe soil degradation. Biological degradation is particularly important because soil biota is involved in numerous soil processes on which soil functioning relies, affecting soil fertility and productivity. For example, soil meso- and macrofauna are especially important in nutrient cycling and in soil structure formation and maintenance, and they are key components of the network that links microbial process to the scale of fields and landscapes where ecosystem services are produced. However, the knowledge of the impact of different agricultural managements on soil meso- and macrofauna in Pampas agroecosystems is far from conclusive at this stage. The reason for this lack of definite conclusions is that this area has been given less attention than in other parts of the world; the response of soil fauna to agricultural practices is complex and taxa

  9. The Pacific-Atlantic connection: Biogeochemical signals in the southern end of the Argentine shelf (United States)

    Garzón, J. E. Cardona; Martínez, A. M.; Barrera, F.; Pfaff, F.; Koch, B. P.; Freije, R. H.; Gómez, E. A.; Lara, R. J.


    The Cape Horn Current transports low-salinity waters from the SE Pacific Ocean into the Atlantic, which are transported further north by the Malvinas current. Biogeochemical signals of this connection were studied by characterization of dissolved organic matter (DOM) by determination of dissolved organic carbon (DOC), fluorescent dissolved organic matter (FDOMc), and DOM humification index (HIX). Further, inorganic nutrients, salinity, temperature, stable isotopic composition of particulate organic nitrogen (δ15N) and chlorophyll a (Chla) were measured in the southern end of the Argentine shelf in March 2012. Three water types were characterized: waters of the Beagle Channel (BCW), coastal waters (CW) and oceanic waters (OW). Highest values of ammonium, DOC, FDOMc and HIX were found in BCW, the lowest in OW, suggesting that terrigenous input is a main source of ammonium and refractory carbon, which is supported by a highly significant inverse correlation of these parameters with salinity. In turn, lowest concentrations of nitrate, silicate and phosphate were found in BCW and CW, and highest in OW, with highly significant correlations of these nutrients with salinity, indicating the contribution of the saltier, nutrient-rich Antarctic Circumpolar Current (ACC) to the Pacific-Atlantic connection system. In general there was an inverse distribution pattern between Chla and those nutrients contributed by the ACC, which is consistent with the transition from coastal waters to the low-silicate, high-nitrate, low-chlorophyll, iron-limited setting of the Subantarctic oceanic waters north of the Polar Front. In contrast, in the low-salinity, internal BCW, high values of ammonium, DOC, HIX and FDOM indicate continental inputs, likely including iron complexes, which could have led to the observed high Chla values. δ15N values were positive in the study region, and same as ammonium, reached a maximum in the inner part of the BCW, declining towards OW. This does not support a

  10. Light water reactor program

    Energy Technology Data Exchange (ETDEWEB)

    Franks, S.M.


    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.

  11. Space Nuclear Reactor Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Poston, David Irvin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    We needed to find a space reactor concept that could be attractive to NASA for flight and proven with a rapid turnaround, low-cost nuclear test. Heat-pipe-cooled reactors coupled to Stirling engines long identified as the easiest path to near-term, low-cost concept.

  12. Reactor Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Van Walle, E


    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)

  13. Nuclear reactor design

    CERN Document Server


    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.

  14. Status of French reactors

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  15. 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))


    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.

  16. Gas cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)



    Although most of the development work on fast breeder reactors has been devoted to the use of liquid metal cooling, interest has been expressed for a number of years in alternative breeder concepts using other coolants. One of a number of concepts in which interest has been retained is the Gas-Cooled Fast Reactor (GCFR). As presently envisioned, it would operate on the uranium-plutonium mixed oxide fuel cycle, similar to that used in the Liquid Metal Fast Breeder Reactor (LMFBR), and would use helium gas as the coolant.

  17. Microfluidic electrochemical reactors (United States)

    Nuzzo, Ralph G [Champaign, IL; Mitrovski, Svetlana M [Urbana, IL


    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.

  18. 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.


    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. The hegemonic construction of technical institutions in the Argentine agriculture: analysis of AAPRESID and AACREA speeches in the last decade

    Directory of Open Access Journals (Sweden)

    María Dolores Liaudat Landivar


    Full Text Available This paper seeks to research on a type of organizations that gains relevance in recent decades in the Argentine agricultural world: the "technical organizations". We intend to trace the ideological nature and the aim of hegemonic construction of the two most representative associations: AAPRESID and AACREA. To advance in this way of research we have worked on the analysis of their discourses, using as sources documents the institutional journals, publications and videos, and minutes of the annual conferences. From this analysis we trace three elements: the roots of local and transnational discourses that they promote, the ways to articulate them and the hegemonic construction operations. These elements allow us to show the strategy of AAPRESID and AACREA to become an intellectual and moral authority in our country.

  20. Italian and Argentine olive oils: a NMR and gas chromatographic study

    Directory of Open Access Journals (Sweden)

    Segre, Annalaura


    Full Text Available High-field Nuclear Magnetic Resonance (NMR spectroscopy and Gas Chromatography (GC were used to analyze 16 monovarietal olive oils obtained from few matched Mediterranean cultivars grown in experimental fields located in Italy and in the Catamarca region of Argentina. The Catamarca region is characterized by extreme pedoclimatic conditions and by a wild spontaneous vegetation. The proposed sampling allows to study the effect of different pedoclimatic conditions on olive oil composition. GC gives the fatty acid profile of olive oil samples. 1H and 13C NMR techniques provide different information: the 1H NMR spectrum allows the measurement of minor components of olive oils such as b-sytosterol, hexanal, trans-2-hexenal, formaldehyde, squalene, cycloartenol and linolenic acid; the 1C NMR spectrum allows to obtain information about glycerol tri-esters of olive oils, i.e., about their acyl composition and positional distribution on glycerol moiety. All the NMR and GC results have been submitted to Linear Discriminant Analysis (LDA and Tree Cluster Analysis (TCA. A careful analysis of the statistical results allows to select the Mediterranean cultivars less affected by the climatic conditions present in the Catamarca region. The selected cultivars produce olive oils which keep their Mediterranean characteristics and which can be proposed as colonizing plants in this wild Argentine region.La espectroscopía de Resonancia Magnética Nuclear de alta resolución (RMN y Cromatografía Gaseosa (CG fueron utilizadas para analizar 16 monovariedades de aceites de oliva, obtenidas de algunos olivares Mediterráneos cultivados contemporáneamente en campos experimentales localizados en Italia y en la región de Catamarca en Argentina. Estas muestras permiten estudiar diferentes condiciones pedoclimáticas en la composición de los aceite de oliva. La CG proporciona el perfil en ácidos grasos de los aceites de oliva y las técnicas RMN 1H y RMN 13C suministran

  1. En torno a la desilusión argentina On Argentine disillusionment

    Directory of Open Access Journals (Sweden)

    Andrés Kozel


    its emergence with general social and economic processes?; How can we extract the incidents of this idea?; How can we characterize and classify its main expressions?; How can we think about the global meaning of this ideological and political process? The general exposition of the research is focused on showing that the topic of the failure acquired its decisive attributes during the first half of the 20th century, through a complex dynamic, comprised of diverse channels which should be captured in their specificity, although without losing sight of the more general movement of which they form a part: seen globally, this movement contributed to the erosion of an entire ideological-cultural configuration, which I call "argentine illusion". The backdrop of the process was none other than the growing social complexity, the greater and more dissonant discursive diversification (Tulio Halperín and the profound hegemony crisis which the country experienced throughout the period.

  2. Structure, composition and metagenomic profile of soil microbiomes associated to agricultural land use and tillage systems in Argentine Pampas. (United States)

    Carbonetto, Belén; Rascovan, Nicolás; Álvarez, Roberto; Mentaberry, Alejandro; Vázquez, Martin P


    Agriculture is facing a major challenge nowadays: to increase crop production for food and energy while preserving ecosystem functioning and soil quality. Argentine Pampas is one of the main world producers of crops and one of the main adopters of conservation agriculture. Changes in soil chemical and physical properties of Pampas soils due to different tillage systems have been deeply studied. Still, not much evidence has been reported on the effects of agricultural practices on Pampas soil microbiomes. The aim of our study was to investigate the effects of agricultural land use on community structure, composition and metabolic profiles on soil microbiomes of Argentine Pampas. We also compared the effects associated to conventional practices with the effects of no-tillage systems. Our results confirmed the impact on microbiome structure and composition due to agricultural practices. The phyla Verrucomicrobia, Plactomycetes, Actinobacteria, and Chloroflexi were more abundant in non cultivated soils while Gemmatimonadetes, Nitrospirae and WS3 were more abundant in cultivated soils. Effects on metabolic metagenomic profiles were also observed. The relative abundance of genes assigned to transcription, protein modification, nucleotide transport and metabolism, wall and membrane biogenesis and intracellular trafficking and secretion were higher in cultivated fertilized soils than in non cultivated soils. We also observed significant differences in microbiome structure and taxonomic composition between soils under conventional and no-tillage systems. Overall, our results suggest that agronomical land use and the type of tillage system have induced microbiomes to shift their life-history strategies. Microbiomes of cultivated fertilized soils (i.e. higher nutrient amendment) presented tendencies to copiotrophy while microbiomes of non cultivated homogenous soils appeared to have a more oligotrophic life-style. Additionally, we propose that conventional tillage systems may

  3. Reactor BR2. Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Gubel, P


    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.

  4. Reactor Neutrino Spectra

    CERN Document Server

    Hayes, A C


    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.

  5. New reactor type proposed

    CERN Multimedia


    "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).

  6. Helias reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Beidler, C.D. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Grieger, G. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Harmeyer, E. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Kisslinger, J. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Karulin, N. [Nuclear Fusion Institute, Moscow (Russian Federation); Maurer, W. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany); Nuehrenberg, J. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Rau, F. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Sapper, J. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Wobig, H. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)


    The present status of Helias reactor studies is characterised by the identification and investigation of specific issues which result from the particular properties of this type of stellarator. On the technical side these are issues related to the coil system, while physics studies have concentrated on confinement, alpha-particle behaviour and ignition conditions. The usual assumptions have been made in those fields which are common to all toroidal fusion reactors: blanket and shield, refuelling and exhaust, safety and economic aspects. For blanket and shield sufficient space has been provided, a detailed concept will be developed in future. To date more emphasis has been placed on scoping and parameter studies as opposed to fixing a specific set of parameters and providing a detailed point study. One result of the Helias reactor studies is that physical dimensions are on the same order as those of tokamak reactors. However, it should be noticed that this comparison is difficult in view of the large spectrum of tokamak reactors ranging from a small reactor like Aries, to a large device such as SEAFP. The notion that the large aspect ratio of 10 or more in Helias configurations also leads to large reactors is misleading, since the large major radius of 22 m is compensated by the average plasma radius of 1.8 m and the average coil radius of 5 m. The plasma volume of 1400 m{sup 3} is about the same as the ITER reactor and the magnetic energy of the coil system is about the same or even slightly smaller than envisaged in ITER. (orig.)

  7. Future Reactor Experiments


    He, Miao


    The measurement of the neutrino mixing angle $\\theta_{13}$ opens a gateway for the next generation experiments to measure the neutrino mass hierarchy and the leptonic CP-violating phase. Future reactor experiments will focus on mass hierarchy determination and the precision measurement of mixing parameters. Mass hierarchy can be determined from the disappearance of reactor electron antineutrinos based on the interference effect of two separated oscillation modes. Relative and absolute measure...

  8. Reactor Neutrino Experiments


    Cao, Jun


    Precisely measuring $\\theta_{13}$ is one of the highest priority in neutrino oscillation study. Reactor experiments can cleanly determine $\\theta_{13}$. Past reactor neutrino experiments are reviewed and status of next precision $\\theta_{13}$ experiments are presented. Daya Bay is designed to measure $\\sin^22\\theta_{13}$ to better than 0.01 and Double Chooz and RENO are designed to measure it to 0.02-0.03. All are heading to full operation in 2010. Recent improvements in neutrino moment measu...

  9. 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....

  10. Moon base reactor system (United States)

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


    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.

  11. The Argentine electric market indicative planning. The transport systems reference guides; Planificacion indicativa del mercado electrico argentino. Las guias de referencia de los sistemas de transporte

    Energy Technology Data Exchange (ETDEWEB)

    Nizovoy, Jorge Alberto; Puleri, Cesar Anibal [Transener S.A., Buenos Aires (Argentina)]. E-mail:


    This work describes the foreseen tool in the Argentine electric market to guide the users regarding transport systems probable evolution, whereas they have to make inversion decisions in order to enlarge the power transportation networks. The Transportation System Reference Guides constitute such tools. Besides referring to its contents and experiences that have guided to improvements on its edition process, the work approaches aspects of the Argentine electric system development, which illustrate the challenger context on which they have been accomplishing and the obtained knowledge from comparison between what has been really accomplished and what has been proposed by the guides. For this, it is used the Transener S.A. company private experience by means of real examples from its seven published Reference Guides.

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

    Energy Technology Data Exchange (ETDEWEB)

    P. Delmolino


    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.


    Energy Technology Data Exchange (ETDEWEB)

    Steimke, J.; Qureshi, Z.; Restivo, M.; Guerrero, H.


    Savannah River Site has five dormant nuclear production reactors. Long term disposition will require filling some reactor buildings with grout up to ground level. Portland cement based grout will be used to fill the buildings with the exception of some reactor tanks. Some reactor tanks contain significant quantities of aluminum which could react with Portland cement based grout to form hydrogen. Hydrogen production is a safety concern and gas generation could also compromise the structural integrity of the grout pour. Therefore, it was necessary to develop a non-Portland cement grout to fill reactors that contain significant quantities of aluminum. Grouts generate heat when they set, so the potential exists for large temperature increases in a large pour, which could compromise the integrity of the pour. The primary purpose of the testing reported here was to measure heat of hydration, specific heat, thermal conductivity and density of various reactor grouts under consideration so that these properties could be used to model transient heat transfer for different pouring strategies. A secondary purpose was to make qualitative judgments of grout pourability and hardened strength. Some reactor grout formulations were unacceptable because they generated too much heat, or started setting too fast, or required too long to harden or were too weak. The formulation called 102H had the best combination of characteristics. It is a Calcium Alumino-Sulfate grout that contains Ciment Fondu (calcium aluminate cement), Plaster of Paris (calcium sulfate hemihydrate), sand, Class F fly ash, boric acid and small quantities of additives. This composition afforded about ten hours of working time. Heat release began at 12 hours and was complete by 24 hours. The adiabatic temperature rise was 54 C which was within specification. The final product was hard and displayed no visible segregation. The density and maximum particle size were within specification.

  14. Všeobecné volby v Argentině 2015: analýza průběhu a dopadů



    This bachelor thesis deals with the general (presidential and parliamentary) election in Argentina in 2015. Its aim is to analyse the progress and the impacts of the election. In the first chapter the thesis deals with the issue of presidential government in theory. It describes the various issues and questions which may arise from the presidential system of government. In the second chapter the thesis describes the Argentine political system from its historical beginnings, through constituti...

  15. Scaleable, High Efficiency Microchannel Sabatier Reactor Project (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...

  16. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Takeshi; Iida, Masaaki; Moriki, Yasuyuki


    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.).

  17. Reactor Structural Materials: Reactor Pressure Vessel Steels

    Energy Technology Data Exchange (ETDEWEB)

    Chaouadi, R


    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.

  18. Thermionic Reactor Design Studies

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred


    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. Nuclear Rocket Engine Reactor

    CERN Document Server

    Lanin, Anatoly


    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.

  20. Operation of Reactor

    Institute of Scientific and Technical Information of China (English)


    3.1 Annual Report of SPR Operation Chu Shaochu Having overseen by National Nuclear Safety Administration and specialists, the reactor restarted up successfully after Safety renovation on April 16, 1996. In August 1996 the normal operation of SPR was approved by the authorities of Naitonal Nuclear Safety Administration. 1 Operation status In 1996, the reactor operated safely for 40 d and the energy released was about 137.3 MW·d. The operation status of SPR is shown in table 1. The reactor started up to higher power (power more than 1 MW) and lower power (for physics experiments) 4 times and 14 times respectively. Measurement of control rod efficiency and other measurement tasks were 2 times and 5 times respectively.

  1. Comparative leaf anatomy in argentine Galactia species Anatomía comparada de hoja en especies argentinas de Galactia

    Directory of Open Access Journals (Sweden)

    G. M. Tourn


    Full Text Available A comparative study of anatomical characters of the leaves of argentine species of Genera Galactia was carried out in order to evaluate their potential value in Taxonomy. In Argentine 14 species and some varieties from Sections Odonia and Collaearia can be found. Section Odonia: G. benthamiana Mich., G. dubia DC., G. fiebrigiana Burkart var. correntina Burkart, G. glaucophylla Harms, G. gracillima Benth., G. latisiliqua Desv., G. longifolia (Jacq. Benth., G. marginalis Benth., G. striata (Jacq. Urban, G. martioides Burkart, G. neesi D. C. var. australis Malme, G. pretiosa Burkart var. pretiosa, G. texana (Scheele A. Gray and G. boavista (Vell. Burkart from Section Collaearia. The characterization of sections is mainly based on reproductive characters, vegetative ones (exomorphological aspects are scarcely considered. The present paper provides a description of anatomical characters of leaves in argentine species of Galactia. Some of them, may have diagnostic value in taxonomic treatment. Special emphasis is placed on the systematic significance of the midvein structure. The aim of the present study, covering 10 species (named in bold, is a to add more data of leaf anatomy characters, thus b to evaluate the systematic relevance and/ or ecological significance.Se realizó un estudio comparativo de la anatomía foliar de especies argentinas del género Galactia (Fabaceae, a fin de evaluar su potencial en taxonomía. En la Argentina se reconocen 14 especies (con algunas variedades, 13 de la sección Odonia -G. benthamiana Mich., G. fiebrigiana Burkart var. correntina Burkart , G. gracillima Benth., G. latisiliqua Desv., G. marginalis Benth., G. striata (Jacq. Urban y G. texana (Scheele A. Gray, G. dubia DC., G. glaucophylla Harms, G. longifolia (Jacq. Benth., G. martioides Burkart, G. neesi DC. var. australis Malme, G. pretiosa Burkart var. Pretiosa- y G. boavista (Vell. Burkart de la sección Collaearia (Burkart, 1971. Los estudios se realizaron en

  2. An Overview of Reactor Concepts, a Survey of Reactor Designs. (United States)


    Public Affairs Office and is releasaole to the National Technical Information Services (NTIS). At NTIS, it will be available to the general public...Reactors that use deu- terium (heavy water) as a coolant can use natural uranium as a fuel. The * Canadian reactor, CANDU , utilizes this concept...reactor core at the top and discharged at the Dotton while the reactor is in operation. The discharged fuel can then b inspected to see if it can De used

  3. Oscillatory flow chemical reactors

    Directory of Open Access Journals (Sweden)

    Slavnić Danijela S.


    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.

  4. 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)


    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.

  5. Reactor Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Van Walle, E


    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.

  6. Reactor operation environmental information document

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  7. High Flux Isotope Reactor (HFIR) (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...

  8. Reactor operation safety information document

    Energy Technology Data Exchange (ETDEWEB)


    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)

  9. Thermal Reactor Safety

    Energy Technology Data Exchange (ETDEWEB)


    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. Chromatographic and Related Reactors. (United States)


    special information about effects of surface heteroge- neity in the methanation reaction. Studies of an efficient multicolumn assembly for measuring...of organic basic catalysts such as pyridine and 4-methylpicoline. It was demonstrated that the chromatographic reactor gave special information about...Programmed Reaction to obtain special information about surface heterogeneity in the methanation reaction. Advantages of stopped flow over steady state

  11. Nuclear Reactors and Technology

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  12. Fusion reactor materials

    Energy Technology Data Exchange (ETDEWEB)



    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.

  13. WATER BOILER REACTOR (United States)

    King, L.D.P.


    As its name implies, this reactor utilizes an aqueous solution of a fissionable element salt, and is also conventional in that it contains a heat exchanger cooling coil immersed in the fuel. Its novelty lies in the utilization of a cylindrical reactor vessel to provide a critical region having a large and constant interface with a supernatant vapor region, and the use of a hollow sleeve coolant member suspended from the cover assembly in coaxial relation with the reactor vessel. Cool water is circulated inside this hollow coolant member, and a gap between its outer wall and the reactor vessel is used to carry off radiolytic gases for recombination in an external catalyst chamber. The central passage of the coolant member defines a reflux condenser passage into which the externally recombined gases are returned and condensed. The large and constant interface between fuel solution and vapor region prevents the formation of large bubbles and minimizes the amount of fuel salt carried off by water vapor, thus making possible higher flux densities, specific powers and power densities.

  14. The First Reactor. (United States)

    Department of Energy, Washington, DC.

    On December 2, 1942, in a racquet court underneath the West Stands of Stagg Field at the University of Chicago, a team of scientists led by Enrico Fermi created the first controlled, self-sustaining nuclear chain reaction. This updated and revised story of the first reactor (or "pile") is based on postwar interviews (as told to Corbin…


    Jonke, A.A.; Graae, J.E.A.; Levitz, N.M.


    A multistage fluidized bed reactor is described in which each of a number of stages is arranged with respect to an associated baffle so that a fluidizing gas flows upward and a granular solid downward through the stages and baffles, whereas the granular solid stopsflowing downward when the flow of fluidizing gas is shut off.

  16. Modeling Chemical Reactors I: Quiescent Reactors

    CERN Document Server

    Michoski, C E; Schmitz, P G


    We introduce a fully generalized quiescent chemical reactor system in arbitrary space $\\vdim =1,2$ or 3, with $n\\in\\mathbb{N}$ chemical constituents $\\alpha_{i}$, where the character of the numerical solution is strongly determined by the relative scaling between the local reactivity of species $\\alpha_{i}$ and the local functional diffusivity $\\mathscr{D}_{ij}(\\alpha)$ of the reaction mixture. We develop an operator time-splitting predictor multi-corrector RK--LDG scheme, and utilize $hp$-adaptivity relying only on the entropy $\\mathscr{S}_{\\mathfrak{R}}$ of the reactive system $\\mathfrak{R}$. This condition preserves these bounded nonlinear entropy functionals as a necessarily enforced stability condition on the coupled system. We apply this scheme to a number of application problems in chemical kinetics; including a difficult classical problem arising in nonequilibrium thermodynamics known as the Belousov-Zhabotinskii reaction where we utilize a concentration-dependent diffusivity tensor $\\mathscr{D}_{ij}(...

  17. Modelling American trypanosomiasis in an endemic zone: application to the initial spread of household infection in the Argentine Chaco. (United States)

    Fabrizio, M C; Schweigmann, N J; Bartoloni, N J


    The complex dynamics of Trypanosoma cruzi infection (Chagas disease) involves different actors and multiple transmission routes. Based on the information currently available, here, we propose a new and more comprehensive model to better understand the dynamics of the infection. This mathematical deterministic model was formulated considering: (i) the three clinical forms in humans: acute, chronic indeterminate and chronic with determinate pathology, (ii) the three main modes of transmission in the human population: vector-borne, congenital and transfusional, (iii) populations of triatomines and dogs as the main domestic reservoirs of T. cruzi and (iv) open populations. A numerical simulation was also performed to estimate the initial spread of the infection in a typical rural household in the endemic zone of the Argentine Gran Chaco. We also analysed the incidence of infected individuals corresponding to each of the three species (humans/triatomines/dogs) over times until the appearance of the first case in the other species. The model predicts that, in the absence of control measures, a few infected individuals are sufficient for the establishment and dispersion of the infection in all the inhabitants of the household. The model proposed and the results obtained allow describing the consequences of the presence of infected individuals in any of the three species considered in the dynamics and the output of the infection.

  18. Relationship Between Beak Morphological Variables and Body Size and Mantle Length of Male and Female Argentine Shortfin Squid (Illex argentinus)

    Institute of Scientific and Technical Information of China (English)

    CHEN Xinjun; LU Huajie; LIU Bilin; FANG Zhou


    Beak of cephalopod is an important hard tissue.Understanding the morphology of beak can yield critical information on the role of cephalopods in the ecosystem.The south patagonic stock of the Argentine shortfin squid,Illex argentinus,is not only one of the most important fishing targets,but also one of the most important species in the marine eco-system of the southwest Atlantic.A total of 430 samples of I.argentinus,including 229 females 103-346mm in mantle length (ML) and 201males 140-298mm in ML,were collected from the area off the Exclusive Economic Zone of Argentinean waters by Chinese squid jigging vessels during February to May 2007.The morphology of their beaks was evaluated.The relationships between beak morphological variables and ML differed significantly among males and females.They could be best described by logarithmic functions for females and linear functions for males except for upper wing length (UWL) and lower rostrum length (LRL),which followed exponential functions in their relationships with ML.The results showed the sexual dimorphism in the relationship between ML and beak morphology for the south patagonic stock of I.argentinus.However,no significant difference was found between males and females in the relationships of beak morphological variables (except for UWL) versus body weight (BW),suggesting that the relationship between beak morphological variables and BW can be used for estimating the biomass consumed by their predators.

  19. Les corps disparus. La fictionnalisation de la guerre sale dans l’Argentine de la dictature militaire (1976-1983

    Directory of Open Access Journals (Sweden)

    Jordi Bonells


    Full Text Available À travers l’analyse de certains romans en langue espagnole sur la dictature militaire en Argentine (1976-1983, l’auteur aborde la question de la disparition comme réalité historique et comme thème littéraire à travers une double approche : analyser l’intentionnalité qui porte ces récits sur le « Proceso » ; rendre compte des mécanismes qui régissent ce que l’on peut appeler la « mise en dictature du roman ».A través del análisis de algunas novelas en lengua española sobre la dictadura militar en Argentina (1976-1983, el autor aborda la cuestión de la desaparición como realidad histórica y como tema literario a partir de un doble enfoque: analizar la intencionalidad subyacente de dichos relatos sobre el Proceso; dar cuenta de los mecanismos que regulan lo que podemos denominar «la novela en dictadura».

  20. The Usefulness of Edible and Medicinal Fabaceae in Argentine and Chilean Patagonia: Environmental Availability and Other Sources of Supply

    Directory of Open Access Journals (Sweden)

    Soledad Molares


    Full Text Available Fabaceae is of great ethnobotanical importance in indigenous and urban communities throughout the world. This work presents a revision of the use of Fabaceae as a food and/or medicinal resource in Argentine-Chilean Patagonia. It is based on a bibliographical analysis of 27 ethnobotanical sources and catalogues of regional flora. Approximately 234 wild species grow in Patagonia, mainly (60% in arid environments, whilst the remainder belong to Sub-Antarctic forest. It was found that 12.8% (30 species, mainly woody, conspicuous plants, are collected for food or medicines. Most of the species used grow in arid environments. Cultivation and purchase/barter enrich the Fabaceae offer, bringing it up to a total of 63 species. The richness of native and exotic species, and the existence of multiple strategies for obtaining these plants, indicates hybridization of knowledge and practices. Only 22% of the total species used are mentioned in bothcontexts of food and medicine, reflecting low-use complementation. This study suggests a significant ecological appearance and a high level of availability in shops and exchange networks in Patagonia, highlighting the need to consider the full set of environmental and socioeconomic factors in research related to the use and cultural importance of plants in regional contexts.

  1. Prevalence and evolution of helmet use in motorcycle riders in an Argentine city (Mar del Plata, 2006-2014

    Directory of Open Access Journals (Sweden)

    Jeremías David Tosi


    Full Text Available Traffic collisions involving motorcyclists are a growing problem in low and middle income countries. Helmet use is the foremost protective measure for this group of road users, however many riders do not wear them. The objective of the present study is to report the changes in helmet use during the period 2006-2014 in an Argentine city and discover associated factors for the year 2014. The sample includes more than 6,900 observations of motorcyclists carried out during the years 2006 (n=962, 2008 (n=977, 2012 (n=2,542, and 2014 (n=2,466. The data indicates a progressive increase in helmet use over time, but differences due to gender and type of rider remain. Factors associated to helmet use in motorcycle drivers during 2014 were: passenger helmet use, motorcycle type, license plate use and gender. Although the results are positive, it is necessary to be attentive to the negative consequences of the growing fleet of motorcycles.

  2. The peri-urban interface and house infestation with Triatoma infestans in the Argentine Chaco: an underreported process?

    Directory of Open Access Journals (Sweden)

    Yael M Provecho


    Full Text Available Peri-urban infestations with triatomine bugs, their sources and their dynamics have rarely been investigated. Here, we corroborated the reported occurrence of Triatoma infestans in a peri-urban area and in neighbouring rural houses in Pampa del Indio, in the Argentine Chaco, and identified its putative sources using spatial analysis and demographic questionnaires. Peri-urban householders reported that 10% of their premises had triatomines, whereas T. infestans was collected by timed manual searches or community-based surveillance in only nine (3% houses. Trypanosoma cruzi-infected T. infestans and Triatoma sordida were collected indoors only in peri-urban houses and were infected with TcV and TcI, respectively. The triatomines fed on chickens, cats and humans. Peri-urban infestations were most frequent in a squatter settlement and particularly within the recently built mud houses of rural immigrants, with large-sized households, more dogs and cats and more crowding. Several of the observed infestations were most likely associated with passive bug transport from other sources and with active bug dispersal from neighbouring foci. Thus, the households in the squatter settlement were at a greater risk of bug invasion and colonisation. In sum, the incipient process of domestic colonisation and transmission, along with persistent rural-to-urban migratory flows and unplanned urbanisation, indicate the need for active vector surveillance and control actions at the peri-urban interface of the Gran Chaco.

  3. Alternative approaches to fusion. [reactor design and reactor physics for Tokamak fusion reactors (United States)

    Roth, R. J.


    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.

  4. Reactor monitoring using antineutrino detectors (United States)

    Bowden, N. S.


    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.

  5. Reactor vessel support system. [LMFBR (United States)

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


    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.

  6. Methanogenesis in Thermophilic Biogas Reactors

    DEFF Research Database (Denmark)

    Ahring, Birgitte Kiær


    Methanogenesis in thermophilic biogas reactors fed with different wastes is examined. The specific methanogenic activity with acetate or hydrogen as substrate reflected the organic loading of the specific reactor examined. Increasing the loading of thermophilic reactors stabilized the process...... as indicated by a lower concentration of volatile fatty acids in the effluent from the reactors. The specific methanogenic activity in a thermophilic pilot-plant biogas reactor fed with a mixture of cow and pig manure reflected the stability of the reactor. The numbers of methanogens counted by the most...... against Methanothrix soehngenii or Methanothrix CALS-I in any of the thermophilic biogas reactors examined. Studies using 2-14C-labeled acetate showed that at high concentrations (more than approx. 1 mM) acetate was metabolized via the aceticlastic pathway, transforming the methyl-group of acetate...


    Wheeler, J.A.


    A design of a reactor is presented in which the fuel elements may be immersed in a liquid coolant when desired without the necessity of removing them from the reactor structure. The fuel elements, containing the fissionable material are in plate form and are disposed within spaced slots in a moderator material, such as graphite to form the core. Adjacent the core is a tank containing the liquid coolant. The fuel elements are mounted in spaced relationship on a rotatable shaft which is located between the core and the tank so that by rotation of the shaft the fuel elements may be either inserted in the slots in the core to sustain a chain reaction or immersed in the coolant.

  8. Compact fusion reactors

    CERN Document Server

    CERN. Geneva


    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.

  9. Reactor Neutrino Spectra


    Hayes, A. C.; Vogel, Petr


    We present a review of the antineutrino spectra emitted from reactors. Knowledge of these spectra and their associated uncertainties is crucial for neutrino oscillation studies. The spectra used to date have been determined either by converting measured electron spectra to antineutrino spectra or by summing over all of the thousands of transitions that make up the spectra, using modern databases as input. The uncertainties in the subdominant corrections to β-decay plague both methods, and we ...


    Greenstreet, B.L.


    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)


    Heckman, T.P.


    A nuclear power reactor of the type in which a liquid moderator-coolant is transformed by nuclear heating into a vapor that may be used to drive a turbo- generator is described. The core of this reactor comprises a plurality of freely suspended tubular fuel elements, called fuel element trains, within which nonboiling pressurized liquid moderator-coolant is preheated and sprayed through orifices in the walls of the trains against the outer walls thereof to be converted into vapor. Passage of the vapor ovcr other unwetted portions of the outside of the fuel elements causes the steam to be superheated. The moderatorcoolant within the fuel elements remains in the liqUid state, and that between the fuel elements remains substantiaily in the vapor state. A unique liquid neutron-absorber control system is used. Advantages expected from the reactor design include reduced fuel element failure, increased stability of operation, direct response to power demand, and circulation of a minimum amount of liquid moderatorcoolant. (A.G.W.)

  12. 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)


    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)

  13. Thermionic Reactor Design Studies

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred


    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

  14. Influence of alternating air injection on the color and “alambrado” of natural black olives cv. Arauco, as compared with the traditional Argentine method



    Ripe black olives cv. Arauco were processed under different conditions to evaluate the effects of alternating air injection (AI) on the color of olives and on spoilage known as “alambrado”, using a system based on the one patented by the “Instituto de la Grasa” (Sevilla, Spain), as compared with the traditional Argentine processing method, which consists of drying the olives in natural air (“extendido”) for 24 hours at 7, 14 and 21 days of fermentation. Four types of fermentation were used: b...

  15. Selection and characterization of Argentine isolates of Trichoderma harzianum for effective biocontrol of Septoria leaf blotch of wheat. (United States)

    Stocco, Marina C; Mónaco, Cecilia I; Abramoff, Cecilia; Lampugnani, Gladys; Salerno, Graciela; Kripelz, Natalia; Cordo, Cristina A; Consolo, Verónica F


    Species of the genus Trichoderma are economically important as biocontrol agents, serving as a potential alternative to chemical control. The applicability of Trichoderma isolates to different ecozones will depend on the behavior of the strains selected from each zone. The present study was undertaken to isolate biocontrol populations of Trichoderma spp. from the Argentine wheat regions and to select and characterize the best strains of Trichoderma harzianum by means of molecular techniques. A total of 84 out of the 240 strains of Trichoderma were able to reduce the disease severity of the leaf blotch of wheat. Thirty-seven strains were selected for the reduction equal to or greater than 50% of the severity, compared with the control. The percentage values of reduction of the pycnidial coverage ranged between 45 and 80%. The same last strains were confirmed as T. harzianum by polymerase chain reaction amplification of internal transcribed spacers, followed by sequencing. Inter-simple sequence repeat was used to examine the genetic variability among isolates. This resulted in a total of 132 bands. Further numerical analysis revealed 19 haplotypes, grouped in three clusters (I, II, III). Shared strains, with different geographical origins and isolated in different years, were observed within each cluster. The origin of the isolates and the genetic group were partially related. All isolates from Paraná were in cluster I, all isolates from Lobería were in cluster II, and all isolates from Pergamino and Santa Fe were in cluster III. Our results suggest that the 37 native strains of T. harzianum are important in biocontrol programs and could be advantageous for the preparation of biopesticides adapted to the agroecological conditions of wheat culture.

  16. Skeletal involvement in Gaucher disease: An observational multicenter study of prognostic factors in the Argentine Gaucher disease patients. (United States)

    Drelichman, Guillermo; Fernández Escobar, Nicolás; Basack, Nora; Aversa, Luis; Larroude, María Silvia; Aguilar, Gabriela; Szlago, Marina; Schenone, Andrea; Fynn, Alcyra; Cuello, María Fernanda; Aznar, Marcela; Fernández, Ramiro; Ruiz, Alba; Reichel, Paola; Guelbert, Norberto; Robledo, Hugo; Watman, Nora; Bolesina, Moira; Elena, Graciela; Veber, S Ernesto; Pujal, Graciela; Galván, Graciela; Chain, Juan José; Arizo, Adriana; Bietti, Julieta; Bar, Daniel; Dragosky, Marta; Marquez, Marisa; Feldman, Leonardo; Muller, Katja; Zirone, Sandra; Buchovsky, Greogorio; Lanza, Victoria; Sanabria, Alba; Fernández, Ignacio; Jaureguiberry, Rossana; Contte, Marcelo; Barbieri María, Angie; Maro, Alejandra; Zárate, Graciela; Fernández, Gabriel; Rapetti, María Cristina; Donato, Hugo; Degano, Adriana; Kantor, Gustavo; Albina, Roberto; Á Lvarez Bollea, María; Brun, María; Bacciedoni, Viviana; Del Río, Francis; Soberón, Bárbara; Boido, Nazario; Schweri, Maya; Borchichi, Sandra; Welsh, Victoria; Corrales, Marcela; Cedola, Alejandra; Carvani, Analía; Diez, Blanca; Richard, Lucía; Baduel, Ccecilia; Nuñez, Gabriela; Colimodio, Rubén; Barazzutti, Lucía; Medici, Hugo; Meschengieser, Susana; Damiani, Germán; Nucifora, María; Girardi, Beatriz; Gómez, Sergio; Papucci, Maura; Verón, David; Quiroga, Luis; Carro, Gustavo; De Ambrosio, Patricia; Ferro, José; Pujol, Marcelo; Castella, Cristina Cabral; Franco, Liliana; Nisnovich, Gisela; Veloso, María; Pacheco, Isabel; Savarino, Mario; Marino, Andrés; Saavedra, José Luis


    Patients with Gaucher type 1 (GD1) throughout Argentina were enrolled in the Argentine bone project to evaluate bone disease and its determinants. We focused on presence and predictors of bone lesions (BL) and their relationship to therapeutic goals (TG) with timing and dose of enzyme replacement therapy (ERT). A total of 124 patients on ERT were enrolled in a multi-center study. All six TG were achieved by 82% of patients: 70.1% for bone pain and 91.1% for bone crisis. However, despite the fact that bone TGs were achieved, residual bone disease was present in 108 patients on ERT (87%) at time 0. 16% of patients showed new irreversible BL (bone infarcts and avascular osteonecrosis) despite ERT, suggesting that they appeared during ERT or were not detected at the moment of diagnosis. We observed 5 prognostic factors that predicted a higher probability of being free of bone disease: optimal ERT compliance; early diagnosis; timely initiation of therapy; ERT initiation dose ≥45 UI/kg/EOW; and the absence of history of splenectomy. Skeletal involvement was classified into 4 major phenotypic groups according to BL: group 1 (12.9%) without BL; group 2 (28.2%) with reversible BL; group 3 (41.9%) with reversible BL and irreversible chronic BL; and group 4 (16.9%) with acute irreversible BL. Our study identifies prognostic factors for achieving best therapeutic outcomes, introduces new risk stratification for patients and suggests the need for a redefinition of bone TG. Am. J. Hematol. 91:E448-E453, 2016. © 2016 Wiley Periodicals, Inc.

  17. Isolation of Salmonella spp. from yacare caiman (Caiman yacare) and broad-snouted caiman (Caiman latirostris) from the Argentine Chaco. (United States)

    Uhart, Marcela; Ferreyra, Hebe; Mattiello, Rosana; Caffer, María Inés; Terragno, Raquel; Schettino, Adriana; Prado, Walter


    Presence of Salmonella spp. was evaluated in yacare caiman (Caiman yacare) and broad-snouted caiman (Caiman latirostris) from a ranching facility in the Argentine Chaco. Crocodilian ranching programs are based on captive breeding of wild-harvested eggs and release of excess hatchlings into the wild. Samples for bacterial isolation were collected from 102 captive (35 C. yacare and 67 C. latirostris) and seven free-ranging caiman (four C. yacare and three C. latirositris) between 2001 and 2005 and from three artificially incubated C. yacare wild eggs. Two Salmonella spp. of known zoonotic potential, S. infantis and S. nottingham, were isolated from captive caiman in 2001 and 2002, respectively. This is the first report for S. nottingham in reptiles and of S. infantis in caiman. Salmonella spp. prevalence varied significantly between years, with a 77% prevalence peak in 2002. Although the cause of this increase was not confirmed, we found no correlation with the type of enclosure, caiman species, or body weight. Deteriorated physical condition of caiman hatchlings due to dietary changes in 2002 could have influenced Salmonella spp. shedding. However, external sources such as food, water, or enclosures could not be ruled out. Pathogenic Salmonella spp. present a risk for human infection. Inadvertent introduction of Salmonella spp. or other bacteria into the environment when caiman are released could pose a threat to wild caiman populations. Prophylactic measures to detect and decrease Salmonella spp. presence in caiman ranching facilities are recommended to reduce risk to humans and make caiman-ranching a sound conservation strategy for crocodilian species.

  18. Invasive breast cancer in Argentine women: association between risk and prognostic factors with antigens of a peptidic and carbohydrate nature

    Directory of Open Access Journals (Sweden)

    Croce MV


    Full Text Available Sandra O Demichelis, Marina T Isla-Larrain, Luciano Cermignani, Cecilio G Alberdi, Amada Segal-Eiras, María Virginia CroceCentre of Basic and Applied Immunological Research, Faculty of Medical Sciences, National University of La Plata, La Plata, ArgentinaObjective: In breast cancer, several tumor markers have been identified. The marker most extensively associated with breast cancer is MUC1. The objective of the study was to analyze prognostic and risk factors in relation to tumor markers in order to clarify breast cancer biology. A total of 349 primary tumor samples and lymph nodes from breast cancer patients were studied. Risk and prognostic factors were considered. An immunohistochemical approach was applied and an extensive statistical analysis was performed, including frequency analysis and analysis of variance. Correlation among variables was performed with principal component analysis.Results: All the antigens showed an increased expression according to tumor size increment; moreover, sialyl Lewis x expression showed a significant increase in relation to disease stage, whereas Tn and TF presented a positive tendency. Vascular invasion was related to sialyl Lewis x expression and number of metastatic lymph nodes. Taking into account risk factors, when a patient had at least one child, Lewis antigens diminished their expression. In relation to breastfeeding, sialyl Lewis x expression diminished, although its apical expression increased.Conclusion: Associations between MUC1 and carbohydrate antigens and risk and prognostic factors show the complexity of the cellular biological behavior that these antigens modulate in breast cancer.Keywords: breast cancer, Argentine women, risk factors, prognostic factors, antigenic expression

  19. Interactive effects of large- and small-scale sources of feral honey-bees for sunflower in the Argentine Pampas.

    Directory of Open Access Journals (Sweden)

    Agustín Sáez

    Full Text Available Pollinators for animal pollinated crops can be provided by natural and semi-natural habitats, ranging from large vegetation remnants to small areas of non-crop land in an otherwise highly modified landscape. It is unknown, however, how different small- and large-scale habitat patches interact as pollinator sources. In the intensively managed Argentine Pampas, we studied the additive and interactive effects of large expanses (up to 2200 ha of natural habitat, represented by untilled isolated "sierras", and narrow (3-7 m wide strips of semi-natural habitat, represented by field margins, as pollinator sources for sunflower (Helianthus annus. We estimated visitation rates by feral honey-bees, Apis mellifera, and native flower visitors (as a group at 1, 5, 25, 50 and 100 m from a field margin in 17 sunflower fields 0-10 km distant from the nearest sierra. Honey-bees dominated the pollinator assemblage accounting for >90% of all visits to sunflower inflorescences. Honey-bee visitation was strongly affected by proximity to the sierras decreasing by about 70% in the most isolated fields. There was also a decline in honey-bee visitation with distance from the field margin, which was apparent with increasing field isolation, but undetected in fields nearby large expanses of natural habitat. The probability of observing a native visitor decreased with isolation from the sierras, but in other respects visitation by flower visitors other than honey-bees was mostly unaffected by the habitat factors assessed in this study. Overall, we found strong hierarchical and interactive effects between the study large and small-scale pollinator sources. These results emphasize the importance of preserving natural habitats and managing actively field verges in the absence of large remnants of natural habitat for improving pollinator services.

  20. Influence of weeds on Argentine ant (Hymenoptera: Formicidae) and obscure mealybug (Hemiptera: Pseudococcidae) in a central California vineyard. (United States)

    Costello, Michael J; Welch, Mark D


    Obscure mealybug is a pest of grapes in the cool climate regions of coastal California, is found on some vineyard weeds, and is tended by the Argentine ant. A study was conducted at a vineyard in Arroyo Grande, CA, to evaluate the impact of weeds on ant activity on grapevines, and the role that ants and weeds have on obscure mealybug infestation in grape clusters. The incidence of the fungus Botrytis cinerea was recorded as well. Treatments were weed exclusion versus the presence of weeds, and ant exclusion versus the presence of ants. Ant activity was evaluated weekly using sugar-based monitoring stations, and mealybug infestation and Botrytis incidence of clusters were evaluated at harvest. Ant exclusion reduced the overall number of ant visits by 82%, and ants increased mealybug infestation of clusters by 53%. Ant activity was 33% higher in the weeds treatment, but there was no impact of weeds on mealybug infestation. We suggest that the higher ant activity recorded in the weeds treatment may have been an artifact of the sugar-based sampling method. Botrytis incidence was three times higher with ants, but did not differ between weeds and weed exclusion treatments. The study supports other research showing a relationship between mealybug infestation and the presence of ants, as well as the lack of impact of floor vegetation on mealybug infestation of grape clusters. It is the first report of a relationship between ants and Botrytis, although it is more likely that the higher Botrytis incidence found here is a result of increased mealybug density than a direct effect by ants.

  1. Favipiravir (T-705 inhibits Junin virus infection and reduces mortality in a guinea pig model of Argentine hemorrhagic fever.

    Directory of Open Access Journals (Sweden)

    Brian B Gowen

    Full Text Available BACKGROUND: Junín virus (JUNV, the etiologic agent of Argentine hemorrhagic fever (AHF, is classified by the NIAID and CDC as a Category A priority pathogen. Presently, antiviral therapy for AHF is limited to immune plasma, which is readily available only in the endemic regions of Argentina. T-705 (favipiravir is a broadly active small molecule RNA-dependent RNA polymerase inhibitor presently in clinical evaluation for the treatment of influenza. We have previously reported on the in vitro activity of favipiravir against several strains of JUNV and other pathogenic New World arenaviruses. METHODOLOGY/PRINCIPAL FINDINGS: To evaluate the efficacy of favipiravir in vivo, guinea pigs were challenged with the pathogenic Romero strain of JUNV, and then treated twice daily for two weeks with oral or intraperitoneal (i.p. favipiravir (300 mg/kg/day starting 1-2 days post-infection. Although only 20% of animals treated orally with favipiravir survived the lethal challenge dose, those that succumbed survived considerably longer than guinea pigs treated with placebo. Consistent with pharmacokinetic analysis that showed greater plasma levels of favipiravir in animals dosed by i.p. injection, i.p. treatment resulted in a substantially higher level of protection (78% survival. Survival in guinea pigs treated with ribavirin was in the range of 33-40%. Favipiravir treatment resulted in undetectable levels of serum and tissue viral titers and prevented the prominent thrombocytopenia and leucopenia observed in placebo-treated animals during the acute phase of infection. CONCLUSIONS/SIGNIFICANCE: The remarkable protection afforded by i.p. favipiravir intervention beginning 2 days after challenge is the highest ever reported for a small molecule antiviral in the difficult to treat guinea pig JUNV challenge model. These findings support the continued development of favipiravir as a promising antiviral against JUNV and other related arenaviruses.

  2. Faulting and erosion in the Argentine Precordillera during changes in subduction regime: Reconciling bedrock cooling and detrital records (United States)

    Fosdick, Julie C.; Carrapa, Barbara; Ortíz, Gustavo


    The Argentine Precordillera is an archetypal retroarc fold-and-thrust belt that records tectonics associated with changing subduction regimes. The interactions between exhumation and faulting in the Precordillera were investigated using apatite and zircon (U-Th-Sm)/He and apatite fission track thermochronometry from the Precordillera and adjacent geologic domains. Inverse modeling of thermal histories constrains eastward in-sequence rock cooling associated with deformation and erosion from 18 to 2 Ma across the Central Precordillera tracking thrusting during this time. The youngest AHe ages (5-2 Ma) and highest erosion rates are located in the eastern and western extremities of the Precordillera and indicate that recent denudation is concentrated at its structural boundaries. Moreover, synchronous rapid Pliocene cooling of the Frontal Cordillera, Eastern Precordillera, and Sierra del Valle Fértil was coeval with initiation of basement-involved faulting in the foreland. Detrital zircon U-Pb geochronology from the ca. 16-8.1 Ma Bermejo foreland basin strata suggests fluvial connectivity westward beyond the Frontal Cordillera to the Main Cordillera and Coast Range followed by an important shift in sediment provenance at ca. 10 Ma. At this time, we suggest that a substantial decrease in Permo-Triassic igneous sources in the Frontal Cordillera and concurrent increase in recycled zircons signatures of Paleozoic strata are best explained by uplift and erosion of the Precordillera during widening of the thrust-belt. Bedrock thermochronology and modeling indicate a 2-6 Myr lag time between faulting-related cooling in the hinterland and the detrital record of deformation in the foreland basin, suggesting that for tectonically active semi-arid settings, bedrock cooling may be more sensitive to onset of faulting. We suggest that high erosion rates in the Frontal Cordillera and Eastern Precordillera are associated with increased interplate coupling during shallowing of the

  3. Variation in the proximate composition and fatty acid profile recovered from Argentine hake (Merluccius hubbsi waste from Patagonia

    Directory of Open Access Journals (Sweden)

    Cretton, M.


    Full Text Available The fish processing operations in Patagonia produce large amounts of waste. The main fishery resource in Argentina is the Argentine hake (Merluccius hubbsi. The ports of the province of Chubut (the most important of which are Puerto Madryn, Rawson and Comodoro Rivadavia, together with Caleta Paula Port (province of Santa Cruz, in the Argentine Patagonia, capture more than 82,000 tons of hake annualy, 80% of which are of M. hubbsi, which is mostly converted into fillets. From this capture, about 2,296 tons of liver would be available for the extraction of oil. To promote the recovery and industrial use of fish oil, in the present study, we determined the variation in the proximate composition and fatty acid profile of Argentine hake waste from the ports mentioned above at different catch times. Proximate composition was determined according of the Official Methods of Analysis (AOAC. Fatty acid profile was analyzed by gas chromatography of the fatty acid methyl esters (FAMEs. A standard mixture of FAMEs was run under identical conditions to identify the compounds on the basis of their retention times. Fatty acids were quantified using heptadecanoic acid (C17:0 as internal standard. The highest lipid recovery (27.0 to 41.8% of total lipids was obtained from the liver fraction. Palmitic acid (C16:0, oleic acid (18:1 n9, docosahexaenoic acid (22:6 n3, eicosapentaenoic acid (20:5 n3 and palmitoleic acid (16:1 were the main constituents. Protein levels in viscera without livers (V-L were higher than those in the liver. The extraction of marine fish oil and the production of fish offal meal from waste from fish factories would contribute to the sustainability of the regional industry, because it would also decrease the volume of waste, with benefits to the environment.El procesamiento de pescados en Patagonia produce gran cantidad de residuos. El recurso de pesca más importante en la Argentina es la merluza argentina (Merluccius hubbsi. En Patagonia

  4. Turning points in reactor design

    Energy Technology Data Exchange (ETDEWEB)

    Beckjord, E.S.


    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.

  5. Fast reactor programme in India

    Indian Academy of Sciences (India)

    P Chellapandi; P R Vasudeva Rao; Prabhat Kumar


    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.

  6. Acceptability of reactors in space

    Energy Technology Data Exchange (ETDEWEB)

    Buden, D.


    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.

  7. Spiral-shaped disinfection reactors

    KAUST Repository

    Ghaffour, Noreddine


    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.

  8. Hydrogen Production in Fusion Reactors


    Sudo, S.; Tomita, Y.; Yamaguchi, S.; Iiyoshi, A.; Momota, H; Motojima, O.; Okamoto, M.; Ohnishi, M.; Onozuka, M; Uenosono, C.


    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.

  9. Neutrino Oscillation Studies with Reactors

    CERN Document Server

    Vogel, Petr; Zhang, Chao


    Nuclear reactors are one of the most intense, pure, controllable, cost-effective, and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavors are quantum mechanical mixtures. Over the past several decades reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle $\\theta_{13}$. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.

  10. FAST NEUTRONIC REACTOR (United States)

    Snell, A.H.


    This patent relates to a reactor and process for carrying out a controlled fast neutron chain reaction. A cubical reactive mass, weighing at least 920 metric tons, of uranium metal containing predominantly U/sup 238/ and having a U/sup 235/ content of at least 7.63% is assembled and the maximum neutron reproduction ratio is limited to not substantially over 1.01 by insertion and removal of a varying amount of boron, the reactive mass being substantially freed of moderator.

  11. Biparticle fluidized bed reactor (United States)

    Scott, C.D.


    A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase is described. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves. 3 figures.

  12. Licensed reactor nuclear safety criteria applicable to DOE reactors

    Energy Technology Data Exchange (ETDEWEB)


    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.

  13. Reactor Physics Analysis Models for a CANDU Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hang Bok


    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.

  14. Argentine Radiation Protection Society Experience in RP education and training; Experiencia de la Sociedad Argentina de Radioproteccion en capacitacion en Proteccion Radiologica

    Energy Technology Data Exchange (ETDEWEB)

    Bomben, A. M.; Ciallella, N. R.; Thomasz, E.; Rudelli, M.; Gisone, P.; Ventura, M.; Gomez Parada, I.; Signoretta, C.


    Since its creation in 1967, the Argentine Radiation Protection Society (SAR) promotes all the radiation protection and nuclear safety aspects not only within the scientific, technical and academic areas, but also to general public. To fulfill this objective, SAR organised training and refresher courses, seminars and workshops on RP subjects. During 2002, SAR organised 7 basic and specialized courses regarding the uses of radioactive materials in industrial applications and the course on medical response in radiological accidents, that was attended by Argentine and other Latin American participants. The programmes of the courses are developed in compliance with the legal requirements and also considering specifics needs. In this paper, the characteristics of the courses are enunciated and basic statistics regarding courses and participants are presented. For the 2003 and 2004, SAR foresees the organisation of 18 courses per year and has the capacity to deliver other courses by request. all the courses are delivered in Spanish language. Based on this educational experience SAR consider a priority the inclusion, of a RP module in all the scientific graduate programmes to generate awareness on the importance of RP. Taking into account the migration of professionals to Europe and North America and the Globalization, SAR advocates the harmonization of RP syllabus to attain an international recognition. (Author)

  15. El campo médico argentino y su mirada al tribadismo, 1936-1955 The medical argentine field and its look on the tribadism, 1936-1955

    Directory of Open Access Journals (Sweden)

    Karina Inés Ramacciotti


    Full Text Available Este artículo describe y analiza la articulación discursiva sobre el lesbianismo en el campo médico argentino entre 1936 y 1955. Las "verdades" de la medicina poseen una fuerza normativa que constituyen un lugar privilegiado para propiciar la aplicación del modelo heterosexual e imponer esta visión al resto de la sociedad. En primer lugar esbozaremos los argumentos médicos en el ámbito europeo por ser los referentes más recorridos por la elite médica argentina. Luego, analizaremos las relecturas y apropiaciones realizadas en el contexto argentino articulándolas con el modelo hegemónico heterosexual de feminidad.This article describes and analyzes the discursive articulation on the lesbianism in the medical Argentine field between 1936 and 1955. The "truths" of the medicine possess a normative force which constitutes a suitable place to favor the heterosexual model and to impose this point of view to the rest of the society. First we will outline the medical arguments in the European area. They were the most accessed models by the medical Argentine elite. Then, we will analyze the re-readings and appropriations realized in Argentina, articulating them with the hegemonic heterosexual model of femininity.

  16. Brookhaven leak reactor to close

    CERN Multimedia

    MacIlwain, C


    The DOE has announced that the High Flux Beam Reactor at Brookhaven is to close for good. Though the news was not unexpected researchers were angry the decision had been taken before the review to assess the impact of reopening the reactor had been concluded (1 page).

  17. Thermochemical reactor systems and methods

    Energy Technology Data Exchange (ETDEWEB)

    Lipinski, Wojciech; Davidson, Jane Holloway; Chase, Thomas Richard


    Thermochemical reactor systems that may be used to produce a fuel, and methods of using the thermochemical reactor systems, utilizing a reactive cylindrical element, an optional energy transfer cylindrical element, an inlet gas management system, and an outlet gas management system.

  18. Chemical-vapor-deposition reactor (United States)

    Chern, S.


    Reactor utilizes multiple stacked trays compactly arranged in paths of horizontally channeled reactant gas streams. Design allows faster and more efficient deposits of film on substrates, and reduces gas and energy consumption. Lack of dead spots that trap reactive gases reduces reactor purge time.

  19. Antineutrino Monitoring of Thorium Reactors

    CERN Document Server

    Akindele, Oluwatomi A; Norman, Eric B


    Various groups have demonstrated that antineutrino monitoring can be successful in assessing the plutonium content in water-cooled nuclear reactors for nonproliferation applications. New reactor designs and concepts incorporate nontraditional fuels types and chemistry. Understanding how these properties affect the antineutrino emission from a reactor can extend the applicability of antineutrino monitoring.Thorium molten salt reactors (MSR) breed U-233, that if diverted constitute an IAEA direct use material. The antineutrino spectrum from the fission of U-233 has been determined, the feasibility of detecting the diversion of a significant quantity, 8 kg of U-233, within the IAEA timeliness goal of 30 days has been evaluated. The antineutrino emission from a thorium reactor operating under normal conditions is compared to a diversion scenario at a 25 meter standoff by evaluating the daily antineutrino count rate and the energy spectrum of the detected antineutrinos. It was found that the diversion of a signifi...

  20. Engineering reactors for catalytic reactions

    Indian Academy of Sciences (India)

    Vivek V Ranade


    Catalytic reactions are ubiquitous in chemical and allied industries. A homogeneous or heterogeneous catalyst which provides an alternative route of reaction with lower activation energy and better control on selectivity can make substantial impact on process viability and economics. Extensive studies have been conducted to establish sound basis for design and engineering of reactors for practising such catalytic reactions and for realizing improvements in reactor performance. In this article, application of recent (and not so recent) developments in engineering reactors for catalytic reactions is discussed. Some examples where performance enhancement was realized by catalyst design, appropriate choice of reactor, better injection and dispersion strategies and recent advances in process intensification/ multifunctional reactors are discussed to illustrate the approach.

  1. Unsteady processes in catalytic reactors

    Energy Technology Data Exchange (ETDEWEB)

    Matros, Yu.Sh.


    In recent years a realization has occurred that reaction and reactor dynamics must be considered when designing and operating catalytic reactors. In this book, the author has focussed on both the processes occurring on individual porous-catalyst particles as well as the phenomena displayed by collections of these particles in fixed-bed reactors. The major topics discussed include the effects of unsteady-state heat and mass transfer, the influence of inhomogeneities and stagnant regions in fixed beds, and reactor operation during forced cycling of operating conditions. Despite the title of the book, attention is also paid to the determination of the number and stability of fixed-bed steady states, with the aim of describing the possibility of controlling reactors at unstable steady states. However, this development is somewhat dated, given the recent literature on multiplicity phenomena and process control.

  2. A model of reactor kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, A.S.; Thompson, B.R.


    The analytical model of nuclear reactor transients, incorporating both mechanical and nuclear effects, simulates reactor kinetics. Linear analysis shows the stability borderline for small power perturbations. In a stable system, initial power disturbances die out with time. With an unstable combination of nuclear and mechanical characteristics, initial disturbances persist and may increase with time. With large instability, oscillations of great magnitude occur. Stability requirements set limits on the power density at which particular reactors can operate. The limiting power density depends largely on the product of two terms: the fraction of delayed neutrons and the frictional damping of vibratory motion in reactor core components. As the fraction of delayed neutrons is essentially fixed, mechanical damping largely determines the maximum power density. A computer program, based on the analytical model, calculates and plots reactor power as a nonlinear function of time in response to assigned values of mechanical and nuclear characteristics.

  3. Metallic fuels for advanced reactors (United States)

    Carmack, W. J.; Porter, D. L.; Chang, Y. I.; Hayes, S. L.; Meyer, M. K.; Burkes, D. E.; Lee, C. B.; Mizuno, T.; Delage, F.; Somers, J.


    In the framework of the Generation IV Sodium Fast Reactor Program, the Advanced Fuel Project has conducted an evaluation of the available fuel systems supporting future sodium cooled fast reactors. This paper presents an evaluation of metallic alloy fuels. Early US fast reactor developers originally favored metal alloy fuel due to its high fissile density and compatibility with sodium. The goal of fast reactor fuel development programs is to develop and qualify a nuclear fuel system that performs all of the functions of a conventional fast spectrum nuclear fuel while destroying recycled actinides. This will provide a mechanism for closure of the nuclear fuel cycle. Metal fuels are candidates for this application, based on documented performance of metallic fast reactor fuels and the early results of tests currently being conducted in US and international transmutation fuel development programs.

  4. Vestiges of an Ordovician west-vergent thin-skinned Ocloyic thrust belt in the Argentine Precordillera, southern Central Andes (United States)

    Thomas, William A.; Astini, Ricardo A.


    Collision of the down-going, Laurentia-derived Argentine Precordillera terrane with the Gondwanan margin drove the Ordovician Ocloyic orogeny, including subduction volcanism, metamorphism, and top-to-west shearing east of the Precordillera. In the Precordillera, above passive-margin carbonates (Lower Ordovician San Juan Limestone and older carbonates), a Middle to Upper Ordovician westward-prograding synorogenic clastic wedge of black shale (Gualcamayo Shale) and coarser clastic sediment (Las Vacas Conglomerate and Trapiche Formation) fills a peripheral foreland basin. New research has identified vestiges of a west-directed thin-skinned Ocloyic foreland thrust belt that has been fragmented by east-directed Andean thrusting. The El Corral thrust sheet, with hanging-wall detachment in the San Juan Limestone, extends over a west-directed footwall frontal ramp and extensive flat to low-angle footwall cutoff in the Gualcamayo and Las Vacas formations. Las Vacas conglomerates in the footwall include olistoliths (10-m scale) exclusively of San Juan Limestone and Gualcamayo Shale; the beds in some olistoliths are folded. The advancing El Corral thrust sheet successively supplied and overrode the stratigraphically restricted olistoliths. In the El Corral footwall, tight west-vergent folds and faults within an anticlinorium in the San Juan Limestone and Gualcamayo Shale suggest a deeper (unexposed) thrust fault, the Los Celestitos fault. West of the anticlinorium, easterly dip (restored to remove Andean deformation) beneath an angular unconformity between Las Vacas and Trapiche beds is consistent geometrically with the trailing limb of a west-vergent fault-propagation anticline in the hanging wall of the subsurface Los Celestitos fault. The same angular unconformity truncates the El Corral fault and hanging-wall strata. In the Trapiche Formation, contrasting sedimentary facies from sandy turbidites westward to limestone-clast megabeds and olistoliths suggest another frontal

  5. Oxigenoterapia en vuelos nacionales e internacionales en la Argentina Oxygen therapy during Argentine-based national and international flights

    Directory of Open Access Journals (Sweden)

    Alejandro Martínez Fraga


    Full Text Available No existe estudio que evalúe el estado de la oxigenoterapia en vuelo (OV en nuestro país. El objetivo de este estudio fue evaluar los requisitos, dificultades, sistemas y costos de la OV de las companías aéreas nacionales (N e internacionales (I que operan desde Buenos Aires. Se utilizó la misma encuesta telefónica y metodología que el estudio de Stoller y col.12. Los autores se comunicaron telefónicamente con 25 aerolíneas que operaban en los dos aeropuertos de Buenos Aires en julio de 2007, y se interrogó sobre los requisitos necesarios para viajar, sistemas y costos. Se usaron técnicas estadísticas convencionales siendo significativa pThere are no data about supplemental oxygen in flight in our country. The objective of our study was to evaluate arranging in-flight-oxygen required by a simulated traveler, system of administration and costs, and to compare the results between Argentine-based (A and international (I airlines. The questionnaire used was similar to that of Stoller et al12. Data collection consisted of telephone calls placed by one of the authors to all commercial air carriers listed in our two Buenos Aires City airports during July 2007. A structured interview with questions was addressed on issues that an oxygen-using air traveler would need to arrange in-flight oxygen. Of the 25 airlines, 6 were discarded because of lack of information (24%, three A -60%-and one I-16%-. All A allowed in-flightoxygen vs. 80% of I (p<0.05, 100% of A and 94% of I required a medical certificate (p=NS; 71% of A and 100% of I required previous notification (p<0.05; 50% of A and 87% of I provided patient interphases of oxygen administration (p=NS. Free of charge oxygen could be provided by 100% of A and 50% of I, with airline charge between 70 to 300 dollars. In conclusion, we observed different policies, rules, availability, and a pronounced lack of standardization of airline information. The cost of oxygen was very different between

  6. Neutrino Experiments at Reactors (United States)

    Reines, F.; Gurr, H. S.; Jenkins, T. L.; Munsee, J. H.


    A description is given of the electron-antineutrino program using a large fission reactor. A search has been made for a neutral weak interaction via the reaction (electron antineutrino + d .> p + n + electron antineutrino), the reaction (electron antineutrino + d .> n + n + e{sup +}) has now been detected, and an effort is underway to observe the elastic scattering reaction (electron antineutrino + e{sup -} .> electron antineutrino + e{sup -}) as well as to measure more precisely the reaction (electron antineutrino + p .> n + e{sup+}). The upper limit on the elastic scattering reaction which we have obtained with our large composite NaI, plastic, liquid scintillation detector is now about 50 times the predicted value.

  7. Neutronic Reactor Shield (United States)

    Fermi, Enrico; Zinn, Walter H.

    The argument of the present Patent is a radiation shield suitable for protection of personnel from both gamma rays and neutrons. Such a shield from dangerous radiations is achieved to the best by the combined action of a neutron slowing material (a moderator) and a neutron absorbing material. Hydrogen is particularly effective for this shield since it is a good absorber of slow neutrons and a good moderator of fast neutrons. The neutrons slowed down by hydrogen may, then, be absorbed by other materials such as boron, cadmium, gadolinium, samarium or steel. Steel is particularly convenient for the purpose, given its effectiveness in absorbing also the gamma rays from the reactor (both primary gamma rays and secondary ones produced by the moderation of neutrons). In particular, in the present Patent a shield is described, made of alternate layers of steel and Masonite (an hydrolized ligno-cellulose material). The object of the present Patent is not discussed in any other published paper.

  8. Licensed reactor nuclear safety criteria applicable to DOE reactors

    Energy Technology Data Exchange (ETDEWEB)


    This document is a compilation and source list of nuclear safety criteria that the Nuclear Regulatory Commission (NRC) applies to licensed reactors; it can be used by DOE and DOE contractors to identify NRC criteria to be evaluated for application to the DOE reactors under their cognizance. The criteria listed are those that are applied to the areas of nuclear safety addressed in the safety analysis report of a licensed reactor. They are derived from federal regulations, USNRC regulatory guides, Standard Review Plan (SRP) branch technical positions and appendices, and industry codes and standards.

  9. Reactor service life extension program

    Energy Technology Data Exchange (ETDEWEB)

    Caskey, G.R.; Sindelar, R.L.; Ondrejcin, R.S.; Baumann, E.W.


    A review of the Savannah River Site production reactor systems was initiated in 1980 and led to implementation of the Reactor Materials Program in 1984 to assess reactor safety and reactor service life. The program evaluated performance of the reactor tanks, primary coolant piping, and thermal shields, components of welded construction that were fabricated from Type 304 stainless steel. The structural integrity analysis of the primary coolant system has shown that the pressure boundary is not susceptible to gross rupture, including a double ended guillotine break or equivalent large area bank. Residual service life is potentially limited by two material degradation modes, irradiation damage and intergranular stress corrosion cracking. Analysis of the structural integrity of the tanks and piping has shown that continued safe operation of the reactors for several additional decades is not limited by the material performance of the primary coolant system. Although irradiation damage has not degraded material behavior to an unacceptable level, past experience has revealed serious difficulties with repair welding on irradiated stainless steel. Stress corrosion can be mitigated by newly identified limits on impurity concentrations in the coolant water and by stress mitigation of weld residual stresses. Work continues in several areas: the effects of helium on mechanical behavior of irradiated stainless steel; improved weld methods for piping and the reactor tanks; and a surveillance program to track irradiation effects on the tank walls.

  10. Reactor service life extension program

    Energy Technology Data Exchange (ETDEWEB)

    Caskey, G.R.; Sindelar, R.L.; Ondrejcin, R.S.; Baumann, E.W.


    A review of the Savannah River Site production reactor systems was initiated in 1980 and led to implementation of the Reactor Materials Program in 1984 to assess reactor safety and reactor service life. The program evaluated performance of the reactor tanks, primary coolant piping, and thermal shields, components of welded construction that were fabricated from Type 304 stainless steel. The structural integrity analysis of the primary coolant system has shown that the pressure boundary is not susceptible to gross rupture, including a double ended guillotine break or equivalent large area bank. Residual service life is potentially limited by two material degradation modes, irradiation damage and intergranular stress corrosion cracking. Analysis of the structural integrity of the tanks and piping has shown that continued safe operation of the reactors for several additional decades is not limited by the material performance of the primary coolant system. Although irradiation damage has not degraded material behavior to an unacceptable level, past experience has revealed serious difficulties with repair welding on irradiated stainless steel. Stress corrosion can be mitigated by newly identified limits on impurity concentrations in the coolant water and by stress mitigation of weld residual stresses. Work continues in several areas: the effects of helium on mechanical behavior of irradiated stainless steel; improved weld methods for piping and the reactor tanks; and a surveillance program to track irradiation effects on the tank walls.

  11. Assessment of torsatrons as reactors

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, J.F. (Oak Ridge National Lab., TN (United States)); Painter, S.L. (Australian National Univ., Canberra, ACT (Australia))


    Stellarators have significant operational advantages over tokamaks as ignited steady-state reactors because stellarators have no dangerous disruptions and no need for continuous current drive or power recirculated to the plasma, both easing the first wall, blanket, and shield design; less severe constraints on the plasma parameters and profiles; and better access for maintenance. This study shows that a reactor based on the torsatron configuration (a stellarator variant) could also have up to double the mass utilization efficiency (MUE) and a significantly lower cost of electricity (COE) than a conventional tokamak reactor (ARIES-I) for a range of assumptions. Torsatron reactors can have much smaller coil systems than tokamak reactors because the coils are closer to the plasma and they have a smaller cross section (higher average current density because of the lower magnetic field). The reactor optimization approach and the costing and component models are those used in the current stage of the ARIES-I tokamak reactor study. Typical reactor parameters for a 1-GW(e) Compact Torsatron reactor example are major radius R[sub 0] = 6.6-8.8 m, on-axis magnetic field B[sup 0] = 4.8-7.5 T, B[sub max] (on coils) = 16 T, MUE 140-210 kW(e)/tonne, and COE (in constant 1990 dollars) = 67-79 mill/kW(e)h. The results are relatively sensitive to assumptions on the level of confinement improvement and the blanket thickness under the inboard half of the helical windings but relatively insensitive to other assumptions.

  12. Concept for LEU Burst Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Steven Karl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kimpland, Robert Herbert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    Design and performance of a proposed LEU burst reactor are sketched. Salient conclusions reached are the following: size would be ~1,500 kg or greater, depending on the size of the central cavity; internal stresses during burst require split rings for relief; the reactor would likely require multiple control and safety rods for fine control; the energy spectrum would be comparable to that of HEU machines; and burst yields and steady-state power levels will be significantly greater in an LEU reactor.

  13. Nuclear reactor downcomer flow deflector

    Energy Technology Data Exchange (ETDEWEB)

    Gilmore, Charles B. (Greensburg, PA); Altman, David A. (Pittsburgh, PA); Singleton, Norman R. (Murrysville, PA)


    A nuclear reactor having a coolant flow deflector secured to a reactor core barrel in line with a coolant inlet nozzle. The flow deflector redirects incoming coolant down an annulus between the core barrel and the reactor vessel. The deflector has a main body with a front side facing the fluid inlet nozzle and a rear side facing the core barrel. The rear side of the main body has at least one protrusion secured to the core barrel so that a gap exists between the rear side of the main body adjacent the protrusion and the core barrel. Preferably, the protrusion is a relief that circumscribes the rear side of the main body.

  14. Safety of VVER-440 reactors

    CERN Document Server

    Slugen, Vladimir


    Safety of VVER-440 Reactors endeavours to promote an increase in the safety of VVER-440 nuclear reactors via the improvement of fission products limitation systems and the implementation of special non-destructive spectroscopic methods for materials testing. All theoretical and experimental studies performed the by author over the last 25 years have been undertaken with the aim of improving VVER-440 defence in depth, which is one of the most important principle for ensuring safety in nuclear power plants. Safety of VVER-440 Reactors is focused on the barrier system through which the safety pri

  15. Random processes in nuclear reactors

    CERN Document Server

    Williams, M M R


    Random Processes in Nuclear Reactors describes the problems that a nuclear engineer may meet which involve random fluctuations and sets out in detail how they may be interpreted in terms of various models of the reactor system. Chapters set out to discuss topics on the origins of random processes and sources; the general technique to zero-power problems and bring out the basic effect of fission, and fluctuations in the lifetime of neutrons, on the measured response; the interpretation of power reactor noise; and associated problems connected with mechanical, hydraulic and thermal noise sources

  16. Fuel Fabrication and Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    The uranium from the enrichment plant is still in the form of UF6. UF6 is not suitable for use in a reactor due to its highly corrosive chemistry as well as its phase diagram. UF6 is converted into UO2 fuel pellets, which are in turn placed in fuel rods and assemblies. Reactor designs are variable in moderators, coolants, fuel, performance etc.The dream of energy ‘too-cheap to meter’ is no more, and now the nuclear power industry is pushing ahead with advanced reactor designs.

  17. Nuclear reactor PBMR and cogeneration; Reactor nuclear PBMR y cogeneracion

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez S, J. R.; Alonso V, G., E-mail: [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)


    In recent years the nuclear reactor designs for the electricity generation have increased their costs, so that at the moment costs are managed of around the 5000 US D for installed kw, reason for which a big nuclear plant requires of investments of the order of billions of dollars, the designed reactors as modular of low power seek to lighten the initial investment of a big reactor dividing the power in parts and dividing in modules the components to lower the production costs, this way it can begin to build a module and finished this to build other, differing the long term investment, getting less risk therefore in the investment. On the other hand the reactors of low power can be very useful in regions where is difficult to have access to the electric net being able to take advantage of the thermal energy of the reactor to feed other processes like the water desalination or the vapor generation for the processes industry like the petrochemical, or even more the possible hydrogen production to be used as fuel. In this work the possibility to generate vapor of high quality for the petrochemical industry is described using a spheres bed reactor of high temperature. (Author)

  18. FASTER test reactor preconceptual design report summary

    Energy Technology Data Exchange (ETDEWEB)

    Grandy, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Belch, H. [Argonne National Lab. (ANL), Argonne, IL (United States); Brunett, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Heidet, F. [Argonne National Lab. (ANL), Argonne, IL (United States); Hill, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hoffman, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Jin, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Mohamed, W. [Argonne National Lab. (ANL), Argonne, IL (United States); Moisseytsev, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Passerini, S. [Argonne National Lab. (ANL), Argonne, IL (United States); Sienicki, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Sumner, T. [Argonne National Lab. (ANL), Argonne, IL (United States); Vilim, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hayes, Steven [Argonne National Lab. (ANL), Argonne, IL (United States)


    The FASTER reactor plant is a sodium-cooled fast spectrum test reactor that provides high levels of fast and thermal neutron flux for scientific research and development. The 120MWe FASTER reactor plant has a superheated steam power conversion system which provides electrical power to a local grid allowing for recovery of operating costs for the reactor plant.


    Directory of Open Access Journals (Sweden)

    Vyacheslav K. Mayevski


    Full Text Available This paper describes a mathematical model of an industrial chemical reactor for production of synthetic rubber. During reactor operation the model parameters vary considerably. To create a control algorithm performed transformation of mathematical model of the reactor in order to obtain a dependency that can be used to determine the model parameters are changing during reactor operation.

  20. FASTER Test Reactor Preconceptual Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Grandy, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Belch, H. [Argonne National Lab. (ANL), Argonne, IL (United States); Brunett, A. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Heidet, F. [Argonne National Lab. (ANL), Argonne, IL (United States); Hill, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hoffman, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Jin, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Mohamed, W. [Argonne National Lab. (ANL), Argonne, IL (United States); Moisseytsev, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Passerini, S. [Argonne National Lab. (ANL), Argonne, IL (United States); Sienicki, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Sumner, T. [Argonne National Lab. (ANL), Argonne, IL (United States); Vilim, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hayes, S. [Argonne National Lab. (ANL), Argonne, IL (United States)


    The FASTER test reactor plant is a sodium-cooled fast spectrum test reactor that provides high levels of fast and thermal neutron flux for scientific research and development. The 120MWe FASTER reactor plant has a superheated steam power conversion system which provides electrical power to a local grid allowing for recovery of operating costs for the reactor plant.

  1. Breeder Reactors, Understanding the Atom Series. (United States)

    Mitchell, Walter, III; Turner, Stanley E.

    The theory of breeder reactors in relationship to a discussion of fission is presented. Different kinds of reactors are characterized by the cooling fluids used, such as liquid metal, gas, and molten salt. The historical development of breeder reactors over the past twenty-five years includes specific examples of reactors. The location and a brief…

  2. Evolution of the tandem mirror reactor concept

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, G.A.; Logan, B.G.


    We discuss the evolution of the tandem mirror reactor concept from the original conceptual reactor design (1977) through the first application of the thermal barrier concept to a reactor design (1979) to the beginning of the Mirror Advanced Reactor Study (1982).

  3. 14 November 2016 - Ambassador Extraordinary and Plenipotentiary H. M. Cima, Permanent Representative of the Argentine Republic to the United Nations Office and other international organisations in Geneva signing the guest book with CERN Director-General F. Gianotti, Director for International Relations C. Warakaulle; Adviser J. Salicio Diez and V. Perez-Reale, CERN HR Department, are also present.

    CERN Multimedia

    Brice, Maximilien


    His Excellency Mr Héctor Marcelo Cima Ambassador Extraordinary and Plenipotentiary Permanent Representative of the Argentine Republic to the United Nations Office and other international organisations in Geneva

  4. Jules Horowitz Reactor, basic design

    Energy Technology Data Exchange (ETDEWEB)

    Bergamaschi, Y.; Bouilloux, Y.; Chantoin, P.; Guigon, B.; Bravo, X.; Germain, C.; Rommens, M.; Tremodeux, P


    Since the shutdown of the SILOE reactor in 1997, the OSIRIS reactor has ensured the needs regarding technological irradiation at CEA including those of its industrial partners and customers. The Jules Horowitz Reactor will replace it. It has the ambition to provide the necessary nuclear data and maintain a fission research capacity in Europe after 2010. This capacity should be service-oriented. It will be established in Cadarache. The Jules Horowitz reactor will also: - represent a significant step in term of performances and experimental capabilities, - be designed with a high flexibility, in order to satisfy the current demand from European industry, research and be able to accommodate future requirements, - reach a high level of safety, according to the best current practice. This paper will present the main functionalities and the design options resulting from the 'preliminary design' studies. (authors)

  5. Advanced Catalytic Hydrogenation Retrofit Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Reinaldo M. Machado


    Industrial hydrogenation is often performed using a slurry catalyst in large stirred-tank reactors. These systems are inherently problematic in a number of areas, including industrial hygiene, process safety, environmental contamination, waste production, process operability and productivity. This program proposed the development of a practical replacement for the slurry catalysts using a novel fixed-bed monolith catalyst reactor, which could be retrofitted onto an existing stirred-tank reactor and would mitigate many of the minitations and problems associated with slurry catalysts. The full retrofit monolith system, consisting of a recirculation pump, gas/liquid ejector and monolith catalyst, is described as a monolith loop reactor or MLR. The MLR technology can reduce waste and increase raw material efficiency, which reduces the overall energy required to produce specialty and fine chemicals.

  6. Advanced Carbothermal Electric Reactor Project (United States)

    National Aeronautics and Space Administration — The overall objective of the Phase 1 effort was to demonstrate the technical feasibility of the Advanced Carbothermal Electric (ACE) Reactor concept. Unlike...

  7. Reactor operation environmental information document

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, L.R.; Hayes, D.W.; Hunter, C.H.; Marter, W.L.; Moyer, R.A.


    This volume is a reactor operation environmental information document for the Savannah River Plant. Topics include meteorology, surface hydrology, transport, environmental impacts, and radiation effects. 48 figs., 56 tabs. (KD)

  8. Unique features of space reactors (United States)

    Buden, David

    Space reactors are designed to meet a unique set of requirements; they must be sufficiently compact to be launched in a rocket to their operational location, operate for many years without maintenance and servicing, operate in extreme environments, and reject heat by radiation to space. To meet these restrictions, operating temperatures are much greater than in terrestrial power plants, and the reactors tend to have a fast neutron spectrum. Currently, a new generation of space reactor power plants is being developed. The major effort is in the SP-100 program, where the power plant is being designed for seven years of full power, and no maintenance operation at a reactor outlet operating temperature of 1350 K.

  9. Thermal Analysis for Mobile Reactor

    Institute of Scientific and Technical Information of China (English)


    <正>Mobile reactor design in the paper is consisted of two grades of thermal electric conversion. The first grade is the thermionic conversion inside the core and the second grade is thermocouple conversion

  10. Teaching About Nature's Nuclear Reactors

    CERN Document Server

    Herndon, J M


    Naturally occurring nuclear reactors existed in uranium deposits on Earth long before Enrico Fermi built the first man-made nuclear reactor beneath Staggs Field in 1942. In the story of their discovery, there are important lessons to be learned about scientific inquiry and scientific discovery. Now, there is evidence to suggest that the Earth's magnetic field and Jupiter's atmospheric turbulence are driven by planetary-scale nuclear reactors. The subject of planetocentric nuclear fission reactors can be a jumping off point for stimulating classroom discussions about the nature and implications of planetary energy sources and about the geomagnetic field. But more importantly, the subject can help to bring into focus the importance of discussing, debating, and challenging current thinking in a variety of areas.

  11. Advanced Carbothermal Electric Reactor Project (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to develop the Advanced Carbothermal Electric (ACE) reactor to efficiently extract oxygen from lunar regolith. Unlike state-of-the-art carbothermal...

  12. Solid State Reactor Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Mays, G.T.


    The Solid State Reactor (SSR) is an advanced reactor concept designed to take advantage of Oak Ridge National Laboratory's (ORNL's) recently developed graphite foam that has enhanced heat transfer characteristics and excellent high-temperature mechanical properties, to provide an inherently safe, self-regulated, source of heat for power and other potential applications. This work was funded by the U.S. Department of Energy's Nuclear Energy Research Initiative (NERI) program (Project No. 99-064) from August 1999 through September 30, 2002. The initial concept of utilizing the graphite foam as a basis for developing an advanced reactor concept envisioned that a suite of reactor configurations and power levels could be developed for several different applications. The initial focus was looking at the reactor as a heat source that was scalable, independent of any heat removal/power conversion process. These applications might include conventional power generation, isotope production and destruction (actinides), and hydrogen production. Having conducted the initial research on the graphite foam and having performed the scoping parametric analyses from neutronics and thermal-hydraulic perspectives, it was necessary to focus on a particular application that would (1) demonstrate the viability of the overall concept and (2) require a reasonably structured design analysis process that would synthesize those important parameters that influence the concept the most as part of a feasible, working reactor system. Thus, the application targeted for this concept was supplying power for remote/harsh environments and a design that was easily deployable, simplistic from an operational standpoint, and utilized the new graphite foam. Specifically, a 500-kW(t) reactor concept was pursued that is naturally load following, inherently safe, optimized via neutronic studies to achieve near-zero reactivity change with burnup, and proliferation resistant. These four major areas

  13. Microchannel Reactors for ISRU Applications (United States)

    Carranza, Susana; Makel, Darby B.; Blizman, Brandon; Ward, Benjamin J.


    Affordable planning and execution of prolonged manned space missions depend upon the utilization of local resources and the waste products which are formed in manned spacecraft and surface bases. Successful in-situ resources utilization (ISRU) will require component technologies which provide optimal size, weight, volume, and power efficiency. Microchannel reactors enable the efficient chemical processing of in situ resources. The reactors can be designed for the processes that generate the most benefit for each mission. For instance, propellants (methane) can be produced from carbon dioxide from the Mars atmosphere using the Sabatier reaction and ethylene can be produced from the partial oxidation of methane. A system that synthesizes ethylene could be the precursor for systems to synthesize ethanol and polyethylene. Ethanol can be used as a nutrient for Astrobiology experiments, as well as the production of nutrients for human crew (e.g. sugars). Polyethylene can be used in the construction of habitats, tools, and replacement parts. This paper will present recent developments in miniature chemical reactors using advanced Micro Electro Mechanical Systems (MEMS) and microchannel technology to support ISRU of Mars and lunar missions. Among other applications, the technology has been demonstrated for the Sabatier process and for the partial oxidation of methane. Microchannel reactors were developed based on ceramic substrates as well as metal substrates. In both types of reactors, multiple layers coated with catalytic material are bonded, forming a monolithic structure. Such reactors are readily scalable with the incorporation of extra layers. In addition, this reactor structure minimizes pressure drop and catalyst settling, which are common problems in conventional packed bed reactors.

  14. Reactor antineutrinos and nuclear physics (United States)

    Balantekin, A. B.


    Short-baseline reactor neutrino experiments successfully measured the neutrino parameters they set out to measure, but they also identified a shape distortion in the 5-7 MeV range as well as a reduction from the predicted value of the flux. Nuclear physics input into the calculations of reactor antineutrino spectra needs to be better refined if this anomaly is to be interpreted as due to sterile neutrino states.

  15. Sobre las etapas políticas de los doscientos años argentinos On political stages of two centuries argentines

    Directory of Open Access Journals (Sweden)

    Ricardo Sidicaro


    Full Text Available Las diferentes etapas del desarrollo político de los dos siglos argentinos son analizadas por el autor considerando interpretaciones de actores políticos y de sociólogos de cada época que centraron el foco de su interés en los sistemas de poder y en los modos de acción de los dirigentes del Estado y de los partidos políticos.Different stages of political development of two centuries argentines are analyzed by the author considering interpretations of political actors and sociologists of each era that centered the focus of interest in systems of power and modes of action of the leaders of the State and political parties.

  16. Lathyrus linearifolius (Leguminosae-Vicieae confirmed species for the Argentine flora LATHYRUS LINEARIFOLIUS (LEGUMINOSAE-VICIEAE, ESPECIE CONFIRMADA PARA LA FLORA ARGENTINA

    Directory of Open Access Journals (Sweden)

    Ricardo O. Vanni


    Full Text Available Lathyrus linearifolius Vogel is confirmed in the Argentine flora. The number of species of the genus recorded for the northeast region is increased to nine. The new citation is described and illustrated indicating its geographic distribution. A key to distinguish the nine species from NE of Argentina is provided Lathyrus linerifolius Vogel se confirma para la flora Argentina. El número de especies del género mencionadas para la región nordeste se incrementa a nueve. Se describe e ilustra la nueva cita, indicando su distribución geográfica. Se presenta una clave para diferenciar a las nueve especies representadas en el NE de Argentina

  17. Reactor Simulator Testing (United States)

    Schoenfeld, Michael P.; Webster, Kenny L.; Pearson, Boise J.


    As part of the Nuclear Systems Office Fission Surface Power Technology Demonstration Unit (TDU) project, a reactor simulator test loop (RxSim) was design & built to perform integrated testing of the TDU components. In particular, the objectives of RxSim testing was to verify the operation of the core simulator, the instrumentation and control system, and the ground support gas and vacuum test equipment. In addition, it was decided to include a thermal test of a cold trap purification design and a pump performance test at pump voltages up to 150 V since the targeted mass flow rate of 1.75 kg/s was not obtained in the RxSim at the originally constrained voltage of 120 V. This paper summarizes RxSim testing. The gas and vacuum ground support test equipment performed effectively in NaK fill, loop pressurization, and NaK drain operations. The instrumentation and control system effectively controlled loop temperature and flow rates or pump voltage to targeted settings. The cold trap design was able to obtain the targeted cold temperature of 480 K. An outlet temperature of 636 K was obtained which was lower than the predicted 750 K but 156 K higher than the cold temperature indicating the design provided some heat regeneration. The annular linear induction pump (ALIP) tested was able to produce a maximum flow rate of 1.53 kg/s at 800 K when operated at 150 V and 53 Hz.

  18. Novel Catalytic Membrane Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Stuart Nemser, PhD


    There are many industrial catalytic organic reversible reactions with amines or alcohols that have water as one of the products. Many of these reactions are homogeneously catalyzed. In all cases removal of water facilitates the reaction and produces more of the desired chemical product. By shifting the reaction to right we produce more chemical product with little or no additional capital investment. Many of these reactions can also relate to bioprocesses. Given the large number of water-organic compound separations achievable and the ability of the Compact Membrane Systems, Inc. (CMS) perfluoro membranes to withstand these harsh operating conditions, this is an ideal demonstration system for the water-of-reaction removal using a membrane reactor. Enhanced reaction synthesis is consistent with the DOE objective to lower the energy intensity of U.S. industry 25% by 2017 in accord with the Energy Policy Act of 2005 and to improve the United States manufacturing competitiveness. The objective of this program is to develop the platform technology for enhancing homogeneous catalytic chemical syntheses.

  19. LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Iwashige, Kengo


    In an LMFBR type reactor, partitions are disposed to a coolant channel at positions lower than the free liquid level, and the width of the partitions is adapted to have a predetermined condition. Namely, when low temperature fluid overflowing the wall of the coolant channel, flows down and collided against the free liquid surface in the coolant channel, since the dropping speed thereof is reduced abruptly, large pressure waves are caused by kinetic force of the low temperature fluid. However, if appropriate numbers of partitions having an appropriate shape are formed, the dropping speed of the low temperature fluid is moderated to reduce the pressure waves. In addition, since the pressure waves are dispersed to the circumferential and lateral directions of the coolant flow channel respectively, the propagation of the pressure waves can be prevented effectively. Further, when the flow of the low temperature fluid is changed to the circumferential direction, for example, by earthquakes, since the partitions act as members resisting against the circumferential change of the low temperature fluid, the change of the direction can be suppressed. (N.H.)

  20. Calculation of reactor antineutrino spectra in TEXONO

    CERN Document Server

    Chen Dong Liang; Mao Ze Pu; Wong, T H


    In the low energy reactor antineutrino physics experiments, either for the researches of antineutrino oscillation and antineutrino reactions, or for the measurement of abnormal magnetic moment of antineutrino, the flux and the spectra of reactor antineutrino must be described accurately. The method of calculation of reactor antineutrino spectra was discussed in detail. Furthermore, based on the actual circumstances of NP2 reactors and the arrangement of detectors, the flux and the spectra of reactor antineutrino in TEXONO were worked out

  1. Tritium management in fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Galloway, T.R.


    This is a review paper covering the key environmental and safety issues and how they have been handled in the various magnetic and inertial confinement concepts and reference designs. The issues treated include: tritium accident analyses, tritium process control, occupational safety, HTO formation rate from the gas-phase, disposal of tritium contaminated wastes, and environmental impact--each covering the Joint European Tokamak (J.E.T. experiment), Tokamak Fusion Test Reactor (TFTR), Russian T-20, The Next Step (TNS) designs by Westinghouse/ORNL and General Atomic/ANL, the ANL and ORNL EPR's, the G.A. Doublet Demonstration Reactor, the Italian Fintor-D and the ORNL Demo Studies. There are also the following full scale plant reference designs: UWMAK-III, LASL's Theta Pinch Reactor Design (RTPR), Mirror Fusion Reactor (MFR), Tandem Mirror Reactor (TMR), and the Mirror Hybrid Reactor (MHR). There are four laser device breakeven experiments, SHIVA-NOVA, LLL reference designs, ORNL Laser Fusion power plant, the German ''Saturn,'' and LLL's Laser Fusion EPR I and II.

  2. Coordination of the U.S. DOE-Argentine National Atomic Energy Commission (CNEA) science and technology implementing arrangement. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ebadian, M.A.


    In 1989, the US Department of Energy (DOE) established the Office of Environmental Management (EM) and delegated to the office the responsibility of cleaning up the US nuclear weapons complex. EM`s mission has three primary activities: (1) to assess, remediate, and monitor contaminated sites and facilities; (2) to store, treat, and dispose of wastes from past and current operations; and (3) to develop and implement innovative technologies for environmental remediation. To this end, EM has established domestic and international cooperative technology development programs, including one with the Republic of Argentina. Cooperating with Argentine scientific institutes and industry meets US cleanup objectives by: (1) identifying and accessing Argentine EM-related technologies, thereby leveraging investments and providing cost-savings; (2) improving access to technical information, scientific expertise, and technologies applicable to EM needs; and (3) fostering the development of innovative environmental technologies by increasing US private sector opportunities in Argentina in EM-related areas. Florida International University`s Hemispheric Center for Environmental Technology (FIU-HCET) serves as DOE-OST`s primary technology transfer agent. FIU-HCET acts as the coordinating and managing body for the Department of Energy (DOE)-Argentina National Atomic Energy Commission (CNEA) Arrangement. Activities include implementing standard operating procedures, tracking various technical projects, hosting visiting scientists, advising DOE of potential joint projects based on previous studies, and demonstrating/transferring desired technology. HCET hosts and directs the annual Joint Coordinating Committee for Radioactive and Mixed Waste Management meeting between the DOE and CNEA representatives. Additionally, HCET is evaluating the possibility of establishing similar arrangements with other Latin American countries.

  3. Organización y financiamiento del sistema de salud en la Argentina The Argentine Health System: Organization and financial features

    Directory of Open Access Journals (Sweden)

    Hugo E Arce


    Full Text Available El sistema de salud argentino se caracteriza por los siguientes rasgos: a la organización federal del país, donde las provincias se encargan de administrar salud y educación; b coexistencia de servicios públicos y privados, tanto ambulatorios como de internación; c entidades fragmentadas de seguridad social, en su mayoría de origen extra-estatal. Se describen y se calculan los componentes del sistema; se analiza la distribución del poder de decisión entre la autoridad sanitaria nacional y las provinciales y se comparan con la organización de otros países. Se muestran datos estadísticos sobre distribución del gasto en salud y cobertura de servicios en la población. Asimismo se presentan flujos financieros entre las diversas fuentes de recursos, aseguradores, prestadores y los usuarios de cada sector.The Argentine health system is defined by the following features: a federal country organization; b coexistence of public and private services with either outpatients or inpatients; c fragmented entities of social security, most of these originated outside of the state organization. Components of the system are described and weighed; making decisions strength between national and provincial health authorities is analyzed and the Argentine system is compared with that of other countries. Statistical data on distribution of health expenditures and coverage of health services are presented as well as financial flow among diverse funding sources, insurers, providers and users of each sector.

  4. Argentine Space Assets. (United States)


    Interview, December 1996. Perea, Mauricio, La CFI Invierte En La Empresa Encargada De Las Comunicaciones Por Satelite En Argentina. Corporacion Financiera...1 Attn: Servicio de Comunicaciones Navales 630 Indiana Avenue NW Washington, D.C. 20004-2989 13. A rgentine N

  5. V Argentine - matriarhat

    Index Scriptorium Estoniae


    Argentina presidendi Nestor Kirchneri abikaasa Cristina Fernandez de Kirchner edestas presidendivalimistel oma konkurente. C. Kirchneri edu põhjusest, tema võrdlemisest Evita Peroni ja Hillary Clintoniga

  6. Innovative hybrid biological reactors using membranes; Reactores biologico hibrido innovadores utilizando membranas

    Energy Technology Data Exchange (ETDEWEB)

    Diez, R.; Esteban-Garcia, A. L.; Florio, L. de; Rodriguez-Hernandez, L.; Tejero, I.


    In this paper we present two lines of research on hybrid reactors including the use of membranes, although with different functions: RBPM, biofilm reactors and membranes filtration RBSOM, supported biofilm reactors and oxygen membranes. (Author) 14 refs.

  7. Establishment of licensing process for development reactors

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Jong Chull; Yune, Young Gill; Kim, Woong Sik (and others)


    A study on licensing processes for development reactors has been performed to prepare the licensing of development reactors developed in Korea. The contents and results of the study are summarized as follows. The licensing processes for nuclear reactors in Korea, U.S.A., Japan, France, U.K., Canada, and IAEA were surveyed and analyzed to obtain technical bases necessary for establishing licensing processes applicable to development reactors in Korea. Based on the technical bases obtained the above analysis, the purpose, power output, and design characteristics of development reactors were analyzed in detail. The analysis results suggested that development reactors should be classified as a new reactor category (called as 'development reactor') separated from the current reactor categories such as the research reactor and the power reactor. Therefore, it is proposed to establish a new reactor category classified as 'development reactor' for the development reactors. And licensing processes, including licensing technical requirements, licensing document requirements, and other regulatory requirements, were also proposed for the development reactors. In order to institutionalize the licensing processes developed in this study, it is necessary to revise the current laws. Therefore, draft provisions of Atomic Energy Act, Enforcement Decree of the Atomic Energy Act, and Enforcement Regulation of the Atomic Energy Act have been developed for the preparation of the future legalization of the licensing processes proposed for the development reactors. Conclusively, a proposal of licensing processes and draft provisions of laws have been developed for the development reactors. The results proposed in this study can be applied directly to the licensing of the future development reactors. Furthermore, they will also contribute to establishing successfully the licensing processes of the development reactors.

  8. Repairing liner of the reactor; Reparacion del liner del reactor

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar H, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)


    Due to the corrosion problems of the aluminum coating of the reactor pool, a periodic inspections program by ultrasound to evaluate the advance grade and the corrosion speed was settled down. This inspections have shown the necessity to repair some areas, in those that the slimming is significant, of not making it can arrive to the water escape of the reactor pool. The objective of the repair is to place patches of plates of 1/4 inch aluminum thickness in the areas of the reactor 'liner', in those that it has been detected by ultrasound a smaller thickness or similar to 3 mm. To carry out this the fuels are move (of the core and those that are decaying) to a temporary storage, the structure of the core is confined in a tank that this placed inside the pool of the reactor, a shield is placed in the thermal column and it is completely extracted the water for to leave uncover the 'liner' of the reactor. (Author)

  9. Reactor Simulator Testing (United States)

    Schoenfeld, Michael P.; Webster, Kenny L.; Pearson, Boise Jon


    As part of the Nuclear Systems Office Fission Surface Power Technology Demonstration Unit (TDU) project, a reactor simulator test loop (RxSim) was design & built to perform integrated testing of the TDU components. In particular, the objectives of RxSim testing was to verify the operation of the core simulator, the instrumentation and control system, and the ground support gas and vacuum test equipment. In addition, it was decided to include a thermal test of a cold trap purification design and a pump performance test at pump voltages up to 150 V since the targeted mass flow rate of 1.75 kg/s was not obtained in the RxSim at the originally constrained voltage of 120 V. This paper summarizes RxSim testing. The gas and vacuum ground support test equipment performed effectively in NaK fill, loop pressurization, and NaK drain operations. The instrumentation and control system effectively controlled loop temperature and flow rates or pump voltage to targeted settings. The cold trap design was able to obtain the targeted cold temperature of 480 K. An outlet temperature of 636 K was obtained which was lower than the predicted 750 K but 156 K higher than the cold temperature indicating the design provided some heat regeneration. The annular linear induction pump (ALIP) tested was able to produce a maximum flow rate of 1.53 kg/s at 800 K when operated at 150 V and 53 Hz. Keywords: fission, space power, nuclear, liquid metal, NaK.

  10. Reactivity determination in accelerator driven reactors using reactor noise analysis

    Directory of Open Access Journals (Sweden)

    Kostić Ljiljana 1


    Full Text Available Feynman-alpha and Rossi-alpha methods are used in traditional nuclear reactors to determine the subcritical reactivity of a system. The methods are based on the measurement of the mean value, variance and the covariance of detector counts for different measurement times. Such methods attracted renewed attention recently with the advent of the so-called accelerator driven reactors (ADS proposed some time ago. The ADS systems, intended to be used either in energy generation or transuranium transmutation, will use a subcritical core with a strong spallation source. A spallation source has statistical properties that are different from those traditionally used by radioactive sources. In such reactors the monitoring of the subcritical reactivity is very important, and a statistical method, such as the Feynman-alpha method, is capable of resolving this problem.

  11. Heterogeneous Transmutation Sodium Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    S. E. Bays


    The threshold-fission (fertile) nature of Am-241 is used to destroy this minor actinide by capitalizing upon neutron capture instead of fission within a sodium fast reactor. This neutron-capture and its subsequent decay chain leads to the breeding of even neutron number plutonium isotopes. A slightly moderated target design is proposed for breeding plutonium in an axial blanket located above the active “fast reactor” driver fuel region. A parametric study on the core height and fuel pin diameter-to-pitch ratio is used to explore the reactor and fuel cycle aspects of this design. This study resulted in both non-flattened and flattened core geometries. Both of these designs demonstrated a high capacity for removing americium from the fuel cycle. A reactivity coefficient analysis revealed that this heterogeneous design will have comparable safety aspects to a homogeneous reactor of comparable size. A mass balance analysis revealed that the heterogeneous design may reduce the number of fast reactors needed to close the current once-through light water reactor fuel cycle.

  12. Thermonuclear Reflect AB-Reactor

    CERN Document Server

    Bolonkin, Alexander


    The author offers a new kind of thermonuclear reflect reactor. The remarkable feature of this new reactor is a three net AB reflector, which confines the high temperature plasma. The plasma loses part of its energy when it contacts with the net but this loss can be compensated by an additional permanent plasma heating. When the plasma is rarefied (has a small density), the heat flow to the AB reflector is not large and the temperature in the triple reflector net is lower than 2000 - 3000 K. This offered AB-reactor has significantly less power then the currently contemplated power reactors with magnetic or inertial confinement (hundreds-thousands of kW, not millions of kW). But it is enough for many vehicles and ships and particularly valuable for tunnelers, subs and space apparatus, where air to burn chemical fuel is at a premium or simply not available. The author has made a number of innovations in this reactor, researched its theory, developed methods of computation, made a sample computation of typical pr...

  13. Imaging Fukushima Daiichi reactors with muons

    Directory of Open Access Journals (Sweden)

    Haruo Miyadera


    Full Text Available A study of imaging the Fukushima Daiichi reactors with cosmic-ray muons to assess the damage to the reactors is presented. Muon scattering imaging has high sensitivity for detecting uranium fuel and debris even through thick concrete walls and a reactor pressure vessel. Technical demonstrations using a reactor mockup, detector radiation test at Fukushima Daiichi, and simulation studies have been carried out. These studies establish feasibility for the reactor imaging. A few months of measurement will reveal the spatial distribution of the reactor fuel. The muon scattering technique would be the best and probably the only way for Fukushima Daiichi to make this determination in the near future.

  14. Fast breeder reactors an engineering introduction

    CERN Document Server

    Judd, A M


    Fast Breeder Reactors: An Engineering Introduction is an introductory text to fast breeder reactors and covers topics ranging from reactor physics and design to engineering and safety considerations. Reactor fuels, coolant circuits, steam plants, and control systems are also discussed. This book is comprised of five chapters and opens with a brief summary of the history of fast reactors, with emphasis on international and the prospect of making accessible enormous reserves of energy. The next chapter deals with the physics of fast reactors and considers calculation methods, flux distribution,

  15. ABACC: annual report 2012 - Brazilian-Argentine Agency for the Accounting and Control of Nuclear Materials; ABACC: informe annual 2012 - Agencia Brasileiro-Argentina de Contabilidade e Controle de Materiais Nucleares

    Energy Technology Data Exchange (ETDEWEB)



    This document reports the actives during the year 2012 related to: technical activities as safeguards application and advances in application of safeguards; main activities conducted in Brazil and main activities developed at ABACC headquarters; management of the Quadripartite Agreement and of the SCCC - Common System for Accounting and Control of Nuclear Materials; training; technical cooperation; institutional, administrative and financial activities; perspectives for 2013; list of inspectors; list of Brazilian and Argentine facilities subject to the Quadripartite Agreement.

  16. Plasma reactor waste management systems (United States)

    Ness, Robert O., Jr.; Rindt, John R.; Ness, Sumitra R.


    The University of North Dakota is developing a plasma reactor system for use in closed-loop processing that includes biological, materials, manufacturing, and waste processing. Direct-current, high-frequency, or microwave discharges will be used to produce plasmas for the treatment of materials. The plasma reactors offer several advantages over other systems, including low operating temperatures, low operating pressures, mechanical simplicity, and relatively safe operation. Human fecal material, sunflowers, oats, soybeans, and plastic were oxidized in a batch plasma reactor. Over 98 percent of the organic material was converted to gaseous products. The solids were then analyzed and a large amount of water and acid-soluble materials were detected. These materials could possibly be used as nutrients for biological systems.

  17. Nuclear Reactor Engineering Analysis Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Carlos Chavez-Mercado; Jaime B. Morales-Sandoval; Benjamin E. Zayas-Perez


    The Nuclear Reactor Engineering Analysis Laboratory (NREAL) is a sophisticated computer system with state-of-the-art analytical tools and technology for analysis of light water reactors. Multiple application software tools can be activated to carry out different analyses and studies such as nuclear fuel reload evaluation, safety operation margin measurement, transient and severe accident analysis, nuclear reactor instability, operator training, normal and emergency procedures optimization, and human factors engineering studies. An advanced graphic interface, driven through touch-sensitive screens, provides the means to interact with specialized software and nuclear codes. The interface allows the visualization and control of all observable variables in a nuclear power plant (NPP), as well as a selected set of nonobservable or not directly controllable variables from conventional control panels.

  18. Utilisation of thorium in reactors (United States)

    Anantharaman, K.; Shivakumar, V.; Saha, D.


    India's nuclear programme envisages a large-scale utilisation of thorium, as it has limited deposits of uranium but vast deposits of thorium. The large-scale utilisation of thorium requires the adoption of closed fuel cycle. The stable nature of thoria and the radiological issues associated with thoria poses challenges in the adoption of a closed fuel cycle. A thorium fuel based Advanced Heavy Water Reactor (AHWR) is being planned to provide impetus to development of technologies for the closed thorium fuel cycle. Thoria fuel has been loaded in Indian reactors and test irradiations have been carried out with (Th-Pu) MOX fuel. Irradiated thorium assemblies have been reprocessed and the separated 233U fuel has been used for test reactor KAMINI. The paper highlights the Indian experience with the use of thorium and brings out various issues associated with the thorium cycle.

  19. A tubular focused sonochemistry reactor

    Institute of Scientific and Technical Information of China (English)

    ZHOU GuangPing; LIANG ZhaoFeng; LI ZhengZhong; ZHANG YiHui


    This paper presents a new sonochemistry reactor, which consists of a cylindrical tube with a certain length and piezoelectric transducers at tube's end with the longitudinal vibration. The tube can effectively transform the longitudinal vibration into the radial vibration and thereby generates ultrasound. Furthermore, ultrasound can be focused to form high-intensity ultrasonic field inside tube. The reactor boasts of simple structure and its whole vessel wall can radiate ultrasound so that the electroacoustic transfer efficiency is high. The focused ultrasonic field provides good condition for sonochemical reaction. The length of the reactor can be up to 2 meters, and liquids can pass through it continuously, so it can be widely applied in liquid processing such as sonochemistry.

  20. A compact Tokamak transmutation reactor

    Institute of Scientific and Technical Information of China (English)

    QiuLi-Jian; XiaoBing-Jia


    The low aspect ration tokamak is proposed for the driver of a transmutation reactor.The main parameters of the reactor core,neutronic analysis of the blanket are given>the neutron wall loading can be lowered from the magnitude order of 1 MW/m2 to 0.5MW/m2 which is much easier to reach in the near future,and the transmutation efficiency (fission/absorption ratio)is raised further.The blanket power density is about 200MW/m3 which is not difficult to deal with.The key components such as diverter and center conductor post are also designed and compared with conventional TOkamak,Finally,by comparison with the other drivers such as FBR,PWR and accelerator,it can be anticipated that the low aspect ratio transmutation reactor would be one way of fusion energy applications in the near future.

  1. Investigation of KW reactor incident

    Energy Technology Data Exchange (ETDEWEB)

    Sturges, D G [USAEC Hanford Operations Office, Richland, WA (United States); Hauff, T W; Greager, O H [General Electric Co., Richland, WA (United States). Hanford Atomic Products Operation


    The new KW reactor was placed in operation on January 4, 1955, and had been running at relatively low power levels for only 17 hours when it was shut down because of a process tube water leak which appeared to be associated with a slug rupture. After several days of unrewarding effort to remove the slugs and tube by customary methods, it developed that considerable melting of the tube and slugs had taken place. It was then evident that removal of the stuck mass and repairs to the damaged tube channel would require unusual measures that were certain to extend the reactor outage for several weeks. This report documents the work and findings of the Committee which investigated the KW reactor incident. Its content represents unanimous agreement among the three Committee members.

  2. Accountability and non-proliferation nuclear regime: a review of the mutual surveillance Brazilian-Argentine model for nuclear safeguards; Accountability e regime de nao proliferacao nuclear: uma avaliacao do modelo de vigilancia mutua brasileiro-argentina de salvaguardas nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Xavier, Roberto Salles


    The regimes of accountability, the organizations of global governance and institutional arrangements of global governance of nuclear non-proliferation and of Mutual Vigilance Brazilian-Argentine of Nuclear Safeguards are the subject of research. The starting point is the importance of the institutional model of global governance for the effective control of non-proliferation of nuclear weapons. In this context, the research investigates how to structure the current arrangements of the international nuclear non-proliferation and what is the performance of model Mutual Vigilance Brazilian-Argentine of Nuclear Safeguards in relation to accountability regimes of global governance. For that, was searched the current literature of three theoretical dimensions: accountability, global governance and global governance organizations. In relation to the research method was used the case study and the treatment technique of data the analysis of content. The results allowed: to establish an evaluation model based on accountability mechanisms; to assess how behaves the model Mutual Vigilance Brazilian-Argentine Nuclear Safeguards front of the proposed accountability regime; and to measure the degree to which regional arrangements that work with systems of global governance can strengthen these international systems. (author)

  3. L’identité argentine ou la construction d’un mythe littéraire entre Europe et Amérique

    Directory of Open Access Journals (Sweden)

    Lionel Souquet


    Full Text Available Cet article propose une approche de quelques archétypes qui, jusqu’en Europe, ont contribué à construire une image un peu théâtrale et parfois floue de l’Argentin. Une image littéraire avant tout, mais paradoxalement, souvent proche de la réalité socioculturelle car l’identité du romancier latino-américain est souvent liée à un profond engagement qui se traduit par la description et l’analyse – philosophique, politique, historique, sociologique… - du réel. C’est en étudiant le portrait que les intellectuels du XIXème siècle dressent du gaucho, personnage emblématiquement fort mais aussi victime de toutes les manipulations idéologiques, que l’on voit comment l’identité argentine a été forgée autour d’une dichotomie civilisation-barbarie dont le mythe semble encore vivant dans l’Argentine d’aujourd’hui. L’article aborde ensuite le thème de l’immigration, facteur essentiel de la mutation de cette société et de son entrée dans le XXème siècle. Le portrait de l’Argentin de classe moyenne (groupe social qui distingue particulièrement l’Argentine du reste de l’Amérique latine est ensuite dessiné plus en détail, mais à travers le miroir à la fois déformant et grossissant de l’écrivain Manuel Puig. Il est indéniable que l’imaginaire modèle la réalité. La littérature est certes un miroir déformant et contradictoire de la réalité mais elle appartient aussi à cette réalité.This paper focuses on some of the archetypes which have contributed to the construction of the rather theatrical and blurred picture of the Argentinian – including in Europe. Paradoxically enough, this literary image is not so far removed from the socio-cultural reality as the identity of the Latin-American novelist is often defined by his or her engagement with reality through (philosophical, political, historical and sociological description and analysis. A study of the portrayal by 19th

  4. Fundamentals of Nuclear Reactor Physics

    CERN Document Server

    Lewis, E E


    This new streamlined text offers a one-semester treatment of the essentials of how the fission nuclear reactor works, the various approaches to the design of reactors, and their safe and efficient operation. The book includes numerous worked-out examples and end-of-chapter questions to help reinforce the knowledge presented. This textbook offers an engineering-oriented introduction to nuclear physics, with a particular focus on how those physics are put to work in the service of generating nuclear-based power, particularly the importance of neutron reactions and neutron behavior. Engin

  5. PITR: Princeton Ignition Test Reactor

    Energy Technology Data Exchange (ETDEWEB)


    The principal objectives of the PITR - Princeton Ignition Test Reactor - are to demonstrate the attainment of thermonuclear ignition in deuterium-tritium, and to develop optimal start-up techniques for plasma heating and current induction, in order to determine the most favorable means of reducing the size and cost of tokamak power reactors. This report describes the status of the plasma and engineering design features of the PITR. The PITR geometry is chosen to provide the highest MHD-stable values of beta in a D-shaped plasma, as well as ease of access for remote handling and neutral-beam injection.

  6. Analysis of Adiabatic Batch Reactor

    Directory of Open Access Journals (Sweden)

    Erald Gjonaj


    Full Text Available A mixture of acetic anhydride is reacted with excess water in an adiabatic batch reactor to form an exothermic reaction. The concentration of acetic anhydride and the temperature inside the adiabatic batch reactor are calculated with an initial temperature of 20°C, an initial temperature of 30°C, and with a cooling jacket maintaining the temperature at a constant of 20°C. The graphs of the three different scenarios show that the highest temperatures will cause the reaction to occur faster.

  7. External fuel thermionic reactor system. (United States)

    Mondt, J. F.; Peelgren, M. L.


    Thermionic reactors are prime candidates for nuclear electric propulsion. The national thermionic reactor effort is concentrated on the flashlight concept with the external-fuel concept as the backup. The external-fuel concept is very adaptable to a completely modular power subsystem which is attractive for highly reliable long-life applications. The 20- to 25-cm long, externally-fueled converters have been designed, fabricated, and successfully tested with many thermal cycles by electrical heating. However, difficulties have been encountered during encapsulation for nuclear heated tests and none have been started to date. These nuclear tests are required to demonstrate the concept feasibility.

  8. Reactor shutdown delays medical procedures (United States)

    Gwynne, Peter


    A longer-than-expected maintenance shutdown of the Canadian nuclear reactor that produces North America's entire supply of molybdenum-99 - from which the radioactive isotopes technetium-99 and iodine-131 are made - caused delays to the diagnosis and treatment of thousands of seriously ill patients last month. Technetium-99 is a key component of nuclear-medicine scans, while iodine-131 is used to treat cancer and other diseases of the thyroid. Production eventually resumed, but only after the Canadian government had overruled the Canadian Nuclear Safety Commission (CNSC), which was still concerned about the reactor's safety.

  9. Request for Naval Reactors Comment on Proposed Prometheus Space Flight Nuclear Reactor High Tier Reactor Safety Requirements and for Naval Reactors Approval to Transmit These Requirements to JPL

    Energy Technology Data Exchange (ETDEWEB)

    D. Kokkinos


    The purpose of this letter is to request Naval Reactors comments on the nuclear reactor high tier requirements for the PROMETHEUS space flight reactor design, pre-launch operations, launch, ascent, operation, and disposal, and to request Naval Reactors approval to transmit these requirements to Jet Propulsion Laboratory to ensure consistency between the reactor safety requirements and the spacecraft safety requirements. The proposed PROMETHEUS nuclear reactor high tier safety requirements are consistent with the long standing safety culture of the Naval Reactors Program and its commitment to protecting the health and safety of the public and the environment. In addition, the philosophy on which these requirements are based is consistent with the Nuclear Safety Policy Working Group recommendations on space nuclear propulsion safety (Reference 1), DOE Nuclear Safety Criteria and Specifications for Space Nuclear Reactors (Reference 2), the Nuclear Space Power Safety and Facility Guidelines Study of the Applied Physics Laboratory.

  10. Oregon State University TRIGA Reactor annual report

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, T.V.; Johnson, A.G.; Bennett, S.L.; Ringle, J.C.


    The use of the Oregon State University TRIGA Reactor during the year ending June 30, 1979, is summarized. Environmental and radiation protection data related to reactor operation and effluents are included.

  11. Reactor Antineutrino Signals at Morton and Boulby

    CERN Document Server

    Dye, Steve


    Increasing the distance from which an antineutrino detector is capable of monitoring the operation of a registered reactor, or discovering a clandestine reactor, strengthens the Non-Proliferation of Nuclear Weapons Treaty. This report presents calculations of reactor antineutrino interactions, from quasi-elastic neutrino-proton scattering and elastic neutrino-electron scattering, in a water-based detector operated >10 km from a commercial power reactor. It separately calculates signal from the proximal reactor and background from all other registered reactors. The main results are interaction rates and kinetic energy distributions of charged leptons scattered from quasi-elastic and elastic processes. Comparing signal and background distributions evaluates reactor monitoring capability. Scaling the results to detectors of different sizes, target media, and standoff distances is straightforward. Calculations are for two examples of a commercial reactor (P_th~3 GW) operating nearby (L~20 km) an underground facil...

  12. Transmutation of actinides in power reactors. (United States)

    Bergelson, B R; Gerasimov, A S; Tikhomirov, G V


    Power reactors can be used for partial short-term transmutation of radwaste. This transmutation is beneficial in terms of subsequent storage conditions for spent fuel in long-term storage facilities. CANDU-type reactors can transmute the main minor actinides from two or three reactors of the VVER-1000 type. A VVER-1000-type reactor can operate in a self-service mode with transmutation of its own actinides.

  13. Comportamiento de cepas argentinas del virus de la Coriomeningitis Linfocitaria en roedores Behavior of Argentine lymphocytic choriomeningitis virus strains in rodents

    Directory of Open Access Journals (Sweden)

    María Del Cármen Saavedra


    Full Text Available La actividad del virus LCM fue informada en Argentina a comienzos de la década del 70 y sólo han sido aisladas cinco cepas a partir del roedor Mus domesticus y dos de humanos. El objetivo de este trabajo consistió en investigar características biológicas de las cepas argentinas de virus LCM para compararlas entre sí y respecto a las cepas históricas WE y Armstrong. En células L 929 se obtuvieron placas bajo agarosa tanto con las cepas humanas como con las cepas de ratón, pero en células Vero sólo se obtuvieron placas con las cepas humanas. No se observó ninguna característica morfométrica de las placas que distinguiera nítidamente a las cepas históricas de las cepas argentinas, ni se observaron diferencias que se relacionen con las especies de origen de las cepas. Las cepas históricas y las cepas argentinas no fueron letales para ratón recién nacido (rrn generando una infección persistente, según se comprobó al inocular ratones recién nacidos (rrn por vía intracerebral con cepas de virus LCM y detectarse virus en los cerebros cosechados a diferentes días post inoculación. La única excepción fue la cepa Cba An 13065 que resultó virulenta para rrn ya que con sólo 0.026 UFP se logró 1 DL50. Todas las cepas resultaron letales en ratón adulto (rad, siendo las cepas de ratón más virulentas que las cepas de humanos. Estos resultados permitieron evidenciar el diferente comportamiento en cultivos celulares de las cepas de ratón con respecto a las cepas humanas, e identificar marcadores de virulencia mediante la respuesta a la inoculación por vía intracerebral del rad y del rrn.The activity of LCM virus was first reported in Argentina at the beginning of the seventies and only five strains have been isolated from rodents Mus domesticus and two from humans. The objective of this paper was to find differential biological characteristics of Argentine strains of LCM virus comparing them in relation to the historical

  14. Laminar Entrained Flow Reactor (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)


    The Laminar Entrained Flow Reactor (LEFR) is a modular, lab scale, single-user reactor for the study of catalytic fast pyrolysis (CFP). This system can be employed to study a variety of reactor conditions for both in situ and ex situ CFP.

  15. Some new viewpoints in reactor noise analysis

    Institute of Scientific and Technical Information of China (English)

    罗征培; 李富; 等


    It is propsed that the linearity criterion and order criterion via frequency spectrum features without any limitation of the model's phase can be used in reactor noise analysis.The time constant,natural frequency as well as the recovered transfer function of reactors can bhe obtained via the analyzable model based on reactor noise.

  16. Heat-pipe thermionic reactor concept

    DEFF Research Database (Denmark)

    Storm Pedersen, E.


    Main components are reactor core, heat pipe, thermionic converter, secondary cooling system, and waste heat radiator; thermal power generated in reactor core is transported by heat pipes to thermionic converters located outside reactor core behind radiation shield; thermionic emitters are in direct...

  17. Heavy Water Reactor; Reacteurs a eau lourde

    Energy Technology Data Exchange (ETDEWEB)

    Yu, St.; HOpwood, J.; Meneley, D. [Energie Atomique du Canada (Canada)


    This document deals with the Heavy Water Reactor (HWR) technology and especially the Candu (Canada Deuterium Uranium) reactor. This reactors type offers many advantages that promote them for the future. General concepts, a description of the Candu nuclear power plants, the safety systems, the fuel cycle and economical and environmental aspects are included. (A.L.B.)

  18. Operating Modes Of Chemical Reactors Of Polymerization

    Directory of Open Access Journals (Sweden)

    Meruyert Berdieva


    Full Text Available In the work the issues of stable technological modes of operation of main devices of producing polysterol reactors have been researched as well as modes of stable operation of a chemical reactor have been presented, which enables to create optimum mode parameters of polymerization process, to prevent emergency situations of chemical reactor operation in industrial conditions.

  19. Nuclear Reactors and Technology; (USA)

    Energy Technology Data Exchange (ETDEWEB)

    Cason, D.L.; Hicks, S.C. (eds.)


    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 (EDB) 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 EDB and Nuclear Science Abstracts (NSA) database. Current information, added daily to EDB, 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.

  20. A Simple Tubular Reactor Experiment. (United States)

    Hudgins, Robert R.; Cayrol, Bertrand


    Using the hydrolysis of crystal violet dye by sodium hydroxide as an example, the theory, apparatus, and procedure for a laboratory demonstration of tubular reactor behavior are described. The reaction presented can occur at room temperature and features a color change to reinforce measured results. (WB)

  1. Silica-Immobilized Enzyme Reactors (United States)


    immobilized artificial membrane chromatography and lysophospholipid micellar electrokinetic chromatography . J. Chromatogr. A 1998, 810, 95-103. 50...Journal of Liquid Chromatography and Related Technologies. Air Force Research Laboratory Materials and Manufacturing Directorate Airbase...immobilized enzyme reactors (IMERs) can also be integrated directly to further analytical methods such as liquid chromatography or mass spectrometry.[6] In

  2. British high flux beam reactor. (United States)

    Egelstaff, P A


    The neutron scattering technique has become an accepted method for the study of condensed matter. Because of the great scientific and technical value of neutron experiments and the growing body of users, several proposals have been made during the past decade for a nuclear reactor devoted primarily to this technique. This article reviews the reasons for and history behind these proposals.

  3. JPRS Report, Science & Technology, Europe & Latin America, Argentina: Specifications of ARGOS 380 MW Reactor. (United States)


    in the market. ENACE the Empresa Nuclear Argentina dc Ccntralcs Flöctricas, or Argentine Nu- clear Power Plant Corporation is stepping out into the...and economy in operation. ENACE is an acronym for Empresa Nuclear Argentina de Centrales Electricas, or Argentine Nuclear Power Plant Energia Atömica; Buenos Aires, Argentina. Consejo Aso- sor para el Licenciamiento do Instalaciones Nucleares. "Criterios generales de seguridad en

  4. Nuclear reactors and fuel cycle

    Energy Technology Data Exchange (ETDEWEB)



    The Nuclear Fuel Center (CCN) of IPEN produces nuclear fuel for the continuous operation of the IEA-R1 research reactor of IPEN. The serial production started in 1988, when the first nuclear fuel element was delivered for IEA-R1. In 2011, CCN proudly presents the 100{sup th} nuclear fuel element produced. Besides routine production, development of new technologies is also a permanent concern at CCN. In 2005, U{sub 3}O{sub 8} were replaced by U{sub 3}Si{sub 2}-based fuels, and the research of U Mo is currently under investigation. Additionally, the Brazilian Multipurpose Research Reactor (RMB), whose project will rely on the CCN for supplying fuel and uranium targets. Evolving from an annual production from 10 to 70 nuclear fuel elements, plus a thousand uranium targets, is a huge and challenging task. To accomplish it, a new and modern Nuclear Fuel Factory is being concluded, and it will provide not only structure for scaling up, but also a safer and greener production. The Nuclear Engineering Center has shown, along several years, expertise in the field of nuclear, energy systems and correlated areas. Due to the experience obtained during decades in research and technological development at Brazilian Nuclear Program, personnel has been trained and started to actively participate in design of the main system that will compose the Brazilian Multipurpose Reactor (RMB) which will make Brazil self-sufficient in production of radiopharmaceuticals. The institution has participated in the monitoring and technical support concerning the safety, licensing and modernization of the research reactors IPEN/MB-01 and IEA-R1. Along the last two decades, numerous specialized services of engineering for the Brazilian nuclear power plants Angra 1 and Angra 2 have been carried out. The contribution in service, research, training, and teaching in addition to the development of many related technologies applied to nuclear engineering and correlated areas enable the institution to

  5. Climate variability, precipitation trends, and impacts on surface processes in humid to arid climate transition zones of the NW Argentine Andes (24° S, 65° W) (United States)

    Castino, Fabiana; Bookhagen, Bodo; Strecker, Manfred


    In the Andes of NW Argentina the distribution and amount of rainfall and associated surface processes are intimately correlated with pronounced topographic gradients and relief contrasts that intercept easterly moisture-bearing winds related to the South American Monsoon System. These conditions have led to a pronounced elevation-dependent distribution of rainfall, which involves areally limited transition zones between the humid eastern flanks of the orogen (eastern foreland and eastern flanks of the E Cordillera) and the arid orogen interior (Puna Plateau). At interannual scales rainfall patterns in this area can be modulated by different atmospheric disturbances, such as the South Atlantic Convergent Zone and the El Niño Southern Oscillation, resulting in drought or flooding events. During the last two decades, field observations document fluvial aggradation in many intermontane valleys along the eastern flanks of the orogen. This may be related to changing overall climatic conditions, impacting hillslope erosion processes at high elevation, but contemporaneously overwhelming the fluvial system and reducing transport capacity, leading to transient sediment storage. We analyzed rainfall trends in the humid to arid climatic transition zone in the NW Argentine Andes over different time periods to characterize the spatiotemporal variability of rainfall patterns during the last five decades. We relied on both daily ground station (40 stations, 1956-2012) and three-hourly remote sensing rainfall data (3B42 V7 TRMM data, 1998-2014). Seasonal total anomalies analysis shows a complex rainfall pattern, reflected both in station data and remote sensing observations with clear positive (negative) statistically significant trends in the northern Puna Plateau and in the northern part of the foreland basin (southern part of the eastern foreland basin) of up to +20mm/yr (-20mm/yr). Quantile regression of three-hourly and daily data furthermore shows that, on average

  6. Discussion about decision support systems using continuous multi-criteria methods for planning in areas with hydro-basins, agriculture and forests, from examples in Argentine. (United States)

    Anton, J. M.; Grau, J. B.; Tarquis, A. M.; Andina, D.; Cisneros, J. M.; Sanchez, E.


    The authors were involved last years in projects considering diverse decision problems on the use of some regions in Argentine, and also related to rivers or rural services in them. They used sets of multi-criteria decision methods, first discrete when the problem included few distinct alternatives, such as e.g. forestry, traditional or intensive agriculture. For attributes they were different effects, classified then in environmental, economic and social criteria. Extending to other gentler areas, such as at South of the Province of Córdoba, Arg., they have balanced more delicately effects of continuous levels of actions, with a combination of Goal Programming linked methods, and they adopted compromises to have precise solutions. That has shown, and in part open, a line of research, as the setting of such models require various kinds of definitions and valuations, including optimizations, goals with penalties in deviations and restrictions. That can be in diverse detail level and horizon, in presence of various technical and human horizons, and that can influence politics of use of terrain and production that will require public and private agents. The research will consider consideration of use and conservation of soils, human systems and agro productions, and hence models for optimization, preferably in such Goal Programming ways. That will require considering various systems of models, first in theory to be reliable, and then in different areas to evaluate the quality of conclusions, and maybe that successively if results are found advantageous. The Bayesian ways will be considered, but they would require a prospective of sets of precise future states of nature or markets with elicited probabilities, which are neither evident nor decisive for the moment, as changes may occur in years but will be very unexpected or uncertain. The results will be lines of models to aid to establish policies of use of territories, by public agencies setting frames for private

  7. Estudio histórico y bibliométrico de la revista argentina Diaeta Historical and bibliometric study of the argentine journal Diata

    Directory of Open Access Journals (Sweden)

    V Aguirre


    Full Text Available Objetivo: Evaluar el desarrollo de la investigación y la publicación científica de los nutricionistas argentinos a través del análisis histórico y bibliométrico de la revista Diaeta. Método: Diseño descriptivo transversal. Todos los números de la revista Diaeta desde el comienzo de su edición en 1981 hasta fines de 2008 fueron incluidos. Se obtuvo una muestra de 63 ejemplares mediante muestreo estratificado por cada año. Resultados: Se observó un aumento en el porcentaje de Artículos Originales y el aumento en otras áreas temáticas diferentes de la tradicional de Dietoterapia. El promedio del número de autores por artículo científico, fue de tres por Artículo Original y dos autores por Trabajo de Actualización y/o Revisión. Las citas bibliográficas fueron en su mayoría en idioma inglés, en segundo término en español. Las profesiones de los autores más productivos, además de los Licenciados en Nutrición fueron; médicos, químicos, e ingenieros. Conclusiones: La revista DIAETA ha mostrado en pocos años un importante progreso acompañando el desarrollo de la investigación de los nutricionistas del país.Objective: To evaluate the development of research and scientific publications by Argentine nutritionists through the historical and bibliometric analysis of Diaeta journal. Methodology: Descriptive transversal design. All the issues of Diaeta journal, from the beginning of its edition in 1981 through late 2008, were included in this study. A sample of 63 units was obtained through a stratified sampling for each year. Results: An increase in the number of Original Articles and other thematic areas other than the traditional Diet Therapy was observed. The average number of authors per scientific article was three for Original Articles and two authors for Update and/or Review articles. The most frequent language for the bibliographical references was English, Spanish being in the second place. Professions of the most

  8. Heterogeneous Recycling in Fast Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Forget, Benoit; Pope, Michael; Piet, Steven J.; Driscoll, Michael


    Current sodium fast reactor (SFR) designs have avoided the use of depleted uranium blankets over concerns of creating weapons grade plutonium. While reducing proliferation risks, this restrains the reactor design space considerably. This project will analyze various blanket and transmutation target configurations that could broaden the design space while still addressing the non-proliferation issues. The blanket designs will be assessed based on the transmutation efficiency of key minor actinide (MA) isotopes and also on mitigation of associated proliferation risks. This study will also evaluate SFR core performance under different scenarios in which depleted uranium blankets are modified to include minor actinides with or without moderators (e.g. BeO, MgO, B4C, and hydrides). This will be done in an effort to increase the sustainability of the reactor and increase its power density while still offering a proliferation resistant design with the capability of burning MA waste produced from light water reactors (LWRs). Researchers will also analyze the use of recycled (as opposed to depleted) uranium in the blankets. The various designs will compare MA transmutation efficiency, plutonium breeding characteristics, proliferation risk, shutdown margins and reactivity coefficients with a current reference sodium fast reactor design employing homogeneous recycling. The team will also evaluate the out-of-core accumulation and/or burn-down rates of MAs and plutonium isotopes on a cycle-by-cycle basis. This cycle-by-cycle information will be produced in a format readily usable by the fuel cycle systems analysis code, VISION, for assessment of the sustainability of the deployment scenarios.

  9. A new MTR fuel for a new MTR reactor: UMo for the Jules Horowitz reactor

    Energy Technology Data Exchange (ETDEWEB)

    Guigon, B. [CEA Cadarache, F-13108 Saint Paul lez Durance (France); Vacelet, H. [CERCA, Romans (France); Dornbusch, D. [Technicatome, Aix en Provence (France)


    Within some years, the Jules Horowitz Reactor will be the only working experimental reactor (material and fuel testing reactor) in France. It will have to provide facilities for a wide range of needs from activation analysis to power reactor fuel qualification. In this paper the main characteristics of the Jules Horowitz Reactor are presented. Safety criteria are explained. Finally, merits and disadvantages of UMo compared to the standard U{sub 3}Si{sub 2} fuel are discussed. (author)

  10. Neutrino Mixing Discriminates Geo-reactor Models

    CERN Document Server

    Dye, S T


    Geo-reactor models suggest the existence of natural nuclear reactors at different deep-earth locations with loosely defined output power. Reactor fission products undergo beta decay with the emission of electron antineutrinos, which routinely escape the earth. Neutrino mixing distorts the energy spectrum of the electron antineutrinos. Characteristics of the distorted spectrum observed at the earth's surface could specify the location of a geo-reactor, discriminating the models and facilitating more precise power measurement. The existence of a geo-reactor with known position could enable a precision measurement of the neutrino oscillation parameter delta-mass-squared.

  11. Reactor monitoring and safeguards using antineutrino detectors

    CERN Document Server

    Bowden, N S


    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 very 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 reactors, as part of International Atomic Energy Agency (IAEA) and other reactor safeguards regimes. Several efforts to develop this monitoring technique are underway across the globe.

  12. Reactor assessments of advanced bumpy torus configurations

    Energy Technology Data Exchange (ETDEWEB)

    Uckan, N.A.; Owen, L.W.; Spong, D.A.; Miller, R.L.; Ard, W.B.; Pipkins, J.F.; Schmitt, R.J.


    Recently, several configurational approaches and concept improvement schemes were introduced for enhancing the performance of the basic ELMO Bumpy Torus (EBT) concept and for improving its reactor potential. These configurations include planar racetrack and square geometries, Andreoletti coil systems, and bumpy torus-stellarator hybrids (which include twisted racetrack and helical axis stellarator-snakey torus). Preliminary evaluations of reactor implications of each of these configurations have been carried out based on magnetics (vacuum) calculations, transport and scaling relationships, and stability properties. Results indicate favorable reactor projections with a significant reduction in reactor physical size as compared to conventional EBT reactor designs carried out in the past.

  13. Detection of antineutrinos for reactor monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeong Duk [Center for Underground Physics, Institute of Basic Science, Daejeon (Korea, Republic of)


    Reactor neutrinos have been detected in the past 50 years by various detectors for different purposes. Beginning in the 1980s, neutrino physicists have tried to use neutrinos to monitor reactors and develop an optimized detector for nuclear safeguards. Recently, motivated by neutrino oscillation physics, the technology and scale of reactor neutrino detection have progressed considerably. In this review, I will give an overview of the detection technology for reactor neutrinos, and describe the issues related to further improvements in optimized detectors for reactor monitoring.

  14. Brazilian Strategies to Overcome Molybdenum Crisis: Present and Future Perspectives of the Multipurpose Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Osso, J.A. Jr.; Teodoro, R.; Dias, C.R.B.R.; Bezerra, R.R.L.; Villela, L.A.; Correia, J.L.; Perrotta, J.A.; Pereira, G.A.; Zapparoli, C.L. Jr.; Mengatti, J. [Diretoria de Radiofarmacia, Instituto de Pesquisas Energeticas e Nucleares (DIRF-IPEN), Avenida Prof. Lineu Prestes 2242, 05508-000, Sao Paulo, SP (Brazil)


    Nuclear Medicine applications in Brazil have been widely growing in the past few decades, following the world trends. Procedures in oncology and cardiology can be highlighted among its major contributions. Nowadays more than 80% of diagnosis procedures are performed with {sup 99m}Tc, readily available from the elution of {sup 99}Mo-{sup 99m}Tc generators. The Brazilian demand, attended solely by IPEN-CNEN/SP, reaches out more than 320 generators per week with a total activity of about 16.7 TBq (450 Ci), which corresponds to 4% of the overall {sup 99}Mo global demand at an importation cost of US$20 million/year, most of it from Canada. The recent {sup 99}Mo supply crisis deeply affected the distribution of generators in Brazil. A short term solution was achieved with the purchase of {sup 99}Mo from Argentine and more recently from South Africa and also the distribution of generators produced by IBA and Israel. Mid term and long term projects are under way aiming the nationalization of the production of {sup 99}Mo. Both solutions will use the recently approved new Brazilian Multipurpose Reactor (BMR) that will be built near Sao Paulo city and will have a 30 MW power. The mid term project consists on the production of (n,{gamma}) {sup 99}Mo and distribution of {sup 99m}Tc and monodoses of radiopharmaceuticals labelled with {sup 99m}Tc to hospitals near Sao Paulo. The long term project deals with the production of {sup 99}Mo through the fission of {sup 235}U using LEU targets. This work describes the efforts taken by IPEN-CNEN/SP to overcome the recent {sup 99}Mo supply crisis and an up-to-date on the projects aiming the nationalization of the {sup 99}Mo production. (author)

  15. CFD Simulation on Ethylene Furnace Reactor Tubes

    Institute of Scientific and Technical Information of China (English)


    Different mathematical models for ethylene furnace reactor tubes were reviewed. On the basis of these models a new mathematical simulation approach for reactor tubes based on computational fluid dynamics (CFD) technique was presented. This approach took the flow, heat transfer, mass transfer and thermal cracking reactions in the reactor tubes into consideration. The coupled reactor model was solved with the SIMPLE algorithm. Some detailed information about the flow field, temperature field and concentration distribution in the reactor tubes was obtained, revealing the basic characteristics of the hydrodynamic phenomena and reaction behavior in the reactor tubes. The CFD approach provides the necessary information for conclusive decisions regarding the production optimization, the design and improvement of reactor tubes, and the new techniques implementation.

  16. Advanced reactor physics methods for heterogeneous reactor cores (United States)

    Thompson, Steven A.

    To maintain the economic viability of nuclear power the industry has begun to emphasize maximizing the efficiency and output of existing nuclear power plants by using longer fuel cycles, stretch power uprates, shorter outage lengths, mixed-oxide (MOX) fuel and more aggressive operating strategies. In order to accommodate these changes, while still satisfying the peaking factor and power envelope requirements necessary to maintain safe operation, more complexity in commercial core designs have been implemented, such as an increase in the number of sub-batches and an increase in the use of both discrete and integral burnable poisons. A consequence of the increased complexity of core designs, as well as the use of MOX fuel, is an increase in the neutronic heterogeneity of the core. Such heterogeneous cores introduce challenges for the current methods that are used for reactor analysis. New methods must be developed to address these deficiencies while still maintaining the computational efficiency of existing reactor analysis methods. In this thesis, advanced core design methodologies are developed to be able to adequately analyze the highly heterogeneous core designs which are currently in use in commercial power reactors. These methodological improvements are being pursued with the goal of not sacrificing the computational efficiency which core designers require. More specifically, the PSU nodal code NEM is being updated to include an SP3 solution option, an advanced transverse leakage option, and a semi-analytical NEM solution option.

  17. Reactor pulse repeatability studies at the annular core research reactor

    Energy Technology Data Exchange (ETDEWEB)

    DePriest, K.R. [Applied Nuclear Technologies, Sandia National Laboratories, Mail Stop 1146, Post Office Box 5800, Albuquerque, NM 87185-1146 (United States); Trinh, T.Q. [Nuclear Facility Operations, Sandia National Laboratories, Mail Stop 0614, Post Office Box 5800, Albuquerque, NM 87185-1146 (United States); Luker, S. M. [Applied Nuclear Technologies, Sandia National Laboratories, Mail Stop 1146, Post Office Box 5800, Albuquerque, NM 87185-1146 (United States)


    The Annular Core Research Reactor (ACRR) at Sandia National Laboratories is a water-moderated pool-type reactor designed for testing many types of objects in the pulse and steady-state mode of operations. Personnel at Sandia began working to improve the repeatability of pulse operations for experimenters in the facility. The ACRR has a unique UO{sub 2}-BeO fuel that makes the task of producing repeatable pulses difficult with the current operating procedure. The ACRR produces a significant quantity of photoneutrons through the {sup 9}Be({gamma}, n){sup 8}Be reaction in the fuel elements. The photoneutrons are the result of the gammas produced during fission and in fission product decay, so their production is very much dependent on the reactor power history and changes throughout the day/week of experiments in the facility. Because the photoneutrons interfere with the delayed-critical measurements required for accurate pulse reactivity prediction, a new operating procedure was created. The photoneutron effects at delayed critical are minimized when using the modified procedure. In addition, the pulse element removal time is standardized for all pulse operations with the modified procedure, and this produces less variation in reactivity removal times. (authors)

  18. In-reactor performance of pressure tubes in CANDU reactors (United States)

    Rodgers, D. K.; Coleman, C. E.; Griffiths, M.; Bickel, G. A.; Theaker, J. R.; Muir, I.; Bahurmuz, A. A.; Lawrence, S. St.; Resta Levi, M.


    The pressure tubes in CANDU reactors have been operating for times up to about 25 years. The in-reactor performance of Zr-2.5Nb pressure tubes has been evaluated by sampling and periodic inspection. This paper describes the behaviour and discusses the factors controlling the behaviour of these components in currently operating CANDU reactors. The mechanical properties (such as ultimate tensile strength, UTS, and fracture toughness), and delayed-hydride-cracking properties (crack growth rate Vc, and threshold stress intensity factor, KIH) change with irradiation; the former reach a limiting value at a fluence of Pressure tubes exhibit elongation and diametral expansion. The deformation behaviour is a function of operating conditions and material properties that vary from tube-to-tube and as a function of axial location. Semi-empirical predictive models have been developed to describe the deformation response of average tubes as a function of operating conditions. For corrosion and, more importantly deuterium pickup, semi-empirical predictive models have also been developed to represent the behaviour of an average tube. The effect of material variability on corrosion behaviour is less well defined compared with other properties. Improvements in manufacturing have increased fracture resistance by minimising trace elements, especially H and Cl, and reduced variability by tightening controls on forming parameters, especially hot-working temperatures.

  19. The argentine electric sector reform and its correlation with energy efficiency; La reforma del sector electrico argentino y su relacion con la eficiencia energetica

    Energy Technology Data Exchange (ETDEWEB)

    Carpio, Claudio [MGM International (Argentina)


    The reforms in the Argentine electrical sector and the effect these have originated in the energy efficiency policies for public sector are presented. The characteristics exposed of the Argentina Electric sector previous to the 1992 transformation are the departing base that gave rise to the reform fundaments, generating privatizations and a vertical economic scheme. The transformation of the electric sector departing from its environmental regulations yielded in a quality service, good electricity distribution, better prices and proper energy efficiency. [Spanish] Se presentan las reformas en el sector electrico argentino y el efecto que han tenido sobre las politicas de eficiencia energetica elaboradas en el sector publico. Las caracteristicas expuestas del sector electrico argentino previas a la transformacion de 1992 son la base de partida que dio lugar a los fundamentos de la reforma generando privatizaciones y un esquema economico vertical. La transformacion del sector electrico a partir de sus regulaciones energeticas y ambientales redituaron en calidad de servicio, de distribucion de electricidad, precios y en la propia eficiencia energetica.

  20. [Quali-quantitative study of the social variables defining transmission scenarios of Argentine Hemorrhagic Fever in the provinces of Buenos Aires and Santa Fe, 2001-2010]. (United States)

    Mastrangelo, Andrea; Tagliabue, Paula; Berro, Lorena; De Carolis, Darío; Sinchi, Anabel; Digilio, Clara; Enria, Delia


    The aim of this paper was to characterize transmission scenarios of Argentine Hemorrhagic Fever in the post-vaccination period (2001-2010). The study was made up of three phases. The first consisted of a quantitative analysis using the database of the Dr. Julio I. Maiztegui National Institute of Human Viral Diseases [Instituto Nacional de Enfermedades Virales Humanas] regarding the confirmed cases in the period of study (221 cases). Taking into account the transmission site and the known endemic area, cases were grouped into three hypothetical transmission scenarios, identified as: a) classical, b) emerging-reemerging, c) traveling. In the second phase, in order to test these hypotheses, in-depth interviews were carried out from August to September 2011 within an intentionally selected sample of patients distributed proportionally among the three hypotheses. Finally, in the third stage, the data obtained for each hypothetical scenario were grouped into three spatiotemporal scales: the microscale (subject), the mesoscale (locality) and macroscale (region). The results show that new transmission sites are associated with the social dynamics of cereal production and port-bound routes.

  1. Biofouling and biodeterioration in materials stored at the Historical Archive of the Museum of La Plata, Argentine and at the National Archive of the Republic of Cuba. (United States)

    Guiamet, Patricia; Borrego, Sofía; Lavin, Paola; Perdomo, Ivette; de Saravia, Sandra Gómez


    The aims of this paper were to study the biofouling and biodeterioration of photos and maps stored at Historical Archive of the Museum of La Plata (HAMP), Argentine, and two repositories of the National Archive of Cuba Republic (NARC) and to carry out the physiological characterization of the isolated fungi and bacteria. The role of the environmental microbiota in the biofouling formation was also studied. Microbial assemblages in the air were sampled by sedimentation technique while those on documents were sampled by swabbering. Biofilm formation and biofouling were monitored by scanning electron microscope (SEM). Large microbial assemblages were found at NARC archives with the prevalence of genera Aspergillus, Cladosporium and Penicillium, whereas at HAMP these values were lower, Penicillium was the only fungal genus detected. Most of the fungi degraded cellulose and produced pigments and acids, and all of the isolated bacteria had proteolytic and/or cellulolytic activity. In all cases, a higher concentration of viable bacteria than of fungi was isolated from documents. These results correlated with bacterial values detected in air at NARC repositories. However, this correlation cannot be observed at HAMP where Aspergillus, Penicillium and Talaromyces helicus (teleomorph of Penicillium) were isolated. It is the first time that the last genus is reported in documents.

  2. The influence of disturbed habitat on the spatial ecology of Argentine black and white tegu (Tupinambis merianae), a recent invader in the Everglades ecosystem (Florida, USA) (United States)

    Klug, Page E.; Reed, Robert N.; Mazzotti, Frank J.; McEachern, Michelle A.; Vinci, Joy J.; Craven, Katelin K.; Yackel Adams, Amy A.


    The threat of invasive species is often intensified in disturbed habitat. To optimize control programs, it is necessary to understand how degraded habitat influences the behavior of invasive species. We conducted a radio telemetry study to characterize movement and habitat use of introduced male Argentine black and white tegus (Tupinambis merianae) in the Everglades of southern Florida from May to August 2012 at the core and periphery of the introduced range. Tegus at the periphery moved farther per day (mean 131.7 ± 11.6 m, n = 6) compared to tegus at the core (mean 50.3 ± 12.4 m, n = 6). However, activity ranges were not significantly smaller in the core (mean 19.4 ± 8.4 ha, n = 6) compared to periphery (mean 29.1 ± 5.2 ha, n = 6). Peripheral activity ranges were more linear due to activity being largely restricted to levee habitat surrounded by open water or marsh. Tegus were located in shrub or tree habitat (mean 96%) more often than expected based on random locations (mean 58%), and the percent cover of trees and shrubs was higher in activity ranges (mean 61%) than the general study area (17%). Our study highlighted the ability of tegus to spread across the Florida landscape, especially in linear disturbed habitats where increased movement occurred and in areas of altered hydrology where movement is not restricted by water.

  3. Passive acoustic monitoring, development of disturbance calls and differentiation of disturbance and advertisement calls in the Argentine croaker Umbrina canosai (Sciaenidae). (United States)

    Tellechea, J S; Fine, M L; Norbis, W


    Disturbance and advertisement calls of the Argentine croaker Umbrina canosai were recorded from coastal Uruguayan waters. Dissections indicate typical sciaenid extrinsic swimbladder muscles present exclusively in males. Disturbance calls were produced when captive U. canosai were startled, chased with a net or grabbed by the tail. Calls were unusual for sciaenids because each pulse consisted of multiple cycles. The number of cycles per pulse and dominant frequency did not change with U. canosai size, but pulse duration and interpulse interval increased. Advertisement calls were recorded from unseen choruses in the field and confirmed with captive individuals in a large tank. Advertisement calls were recorded throughout the known range of the species in Uruguay indicating a continuous belt of spawning populations. Tank recordings of the same individuals permitted explicit comparisons between the two calls. Advertisement call pulses averaged 2·4 more cycles (11·0-8·6) although pulses of both calls were basically similar as were durations and dominant frequencies. Pulse number, however, differed markedly, averaging 13·6 and 3·4 pulses for disturbance and advertisement calls respectively. Furthermore, disturbance calls were produced as a rapid series with an interpulse interval of 26-31 ms whereas advertisement call patterns were less stereotyped and ranged from <100 to 450 ms. Multicycle pulses distinguished U. canosai from other sympatric sciaenids.

  4. The Pilagá of the Argentine Chaco through an exoticizing and ethnographic lens: The Swedish documentary film Following Indian trails by the Pilcomayo River

    Directory of Open Access Journals (Sweden)

    Anne Gustavsson


    Full Text Available In this article, we explore how traveling relates to image production and how transcultural filmic representations both uphold and are sustained by a “coloniality of seeing.” We pay special attention to the historical conditions of film making in an expedition context and the expectations associated with early film in Sweden. We discuss this through the study of the documentary film Following Indian Trails by the Pilcomayo River, which was recorded during a Swedish expedition to the Argentine Chaco in 1920 and later released in Stockholm in 1950 during a private screening organized by the Swedish Chaco Travellers Association. We argue that the film presents an account inspired by classic ethnography which rescues and puts into circulation images of indigenous people from the “impenetrable” and “savage” Chaco. The ethnographic emphasis in the narrative seems to have shifted with time as it was probably only partly present during the shooting of the footage. In the narrative mode of “monstration,” when bodies meet machines “in the field,” native performances are presented as an “unstaged” and realist spectacle. Later in the 1950 macro-“narration,” encompassing the final cutting and editing of the original footage, fragments of spectacle are systematized into an ethnographic description of primitive life.

  5. [Comparison of FRAX Score without bone mineral density determination and the criteria proposed by the Argentine Osteoporosis Society for the use of antiresorptive therapy in postmenopausal women]. (United States)

    Camporro, Fernando; Redondo, Laura; Bulacio, Exequiel; Gutiérrez Magaldi, Ignacio; Chamale, Elías; Sáenz, Fabián


    To identify patients at high risk of fracture using clinical risk factors could reduce health costs arising from the realization of a bone densitometry. The aim of this study was to compare the FRAX score without bone mineral density (BMD) with the criteria proposed by the Argentine Society of Osteoporosis (SAO) to consider starting antiresorptive treatment. We conducted an observational, cross-sectional study where 330 postmenopausal women between 40 and 90 years of age were included. The number of treatments given if the FRAX tool without BMD had been followed was compared with the number of treatments indicated using the SAO criteria. Using the SAO criteria, 85 (25.8%) patients would initiate antiresorptive treatment compared with 15 (4.5%) using the FRAX without BMD (p = 0.0019). Among the 67 patients with a diagnosis of osteoporosis by BMD determination, all of them (100%) would have received treatment by using the SAO criteria compared with 10 (15%) using the FRAX score (p = 0.011). The use of FRAX without BMD significantly underestimates the number of patients who should receive antiresorptive treatment. In patients diagnosed with osteoporosis by BMD, the FRAX score underestimates the number of patients to be treated.

  6. Population genetic structure and body shape assessment of Pagrus pagrus (Linnaeus, 1758 (Perciformes: Sparidae from the Buenos Aires coast of the Argentine Sea

    Directory of Open Access Journals (Sweden)

    Leonardo P. Porrini

    Full Text Available This study highlights the analysis of the morphological and genetic variation of the common sea bream Pagrus pagrus, and compares its two main areas of concentration: the northern (35ºS - 38ºS and the southern areas (39ºS - 41ºS of the Buenos Aires coast of the Argentine Sea. Body shape characterization presented two significantly different morphotypes (Wilks' Lambda=0.224, P<0.001. Northern individuals displayed a higher middle area while southern ones were smaller and their caudal peduncle was shorter. The northern and southern areas did not yield significant genetic differences either with the control region or the microsatellite loci, revealing that P. pagrus is not genetically structured. However, individuals from these areas should not be managed as a single group since they display distinct life history traits, responsible for morphological differentiation. The presence of two spawning areas with distinctive characteristics would define two stocks of P. pagrus from the Buenos Aires coast.

  7. Fluidized bed coal combustion reactor (United States)

    Moynihan, P. I.; Young, D. L. (Inventor)


    A fluidized bed coal reactor includes a combination nozzle-injector ash-removal unit formed by a grid of closely spaced open channels, each containing a worm screw conveyor, which function as continuous ash removal troughs. A pressurized air-coal mixture is introduced below the unit and is injected through the elongated nozzles formed by the spaces between the channels. The ash build-up in the troughs protects the worm screw conveyors as does the cooling action of the injected mixture. The ash layer and the pressure from the injectors support a fluidized flame combustion zone above the grid which heats water in boiler tubes disposed within and/or above the combustion zone and/or within the walls of the reactor.

  8. Nuclear reactor alignment plate configuration

    Energy Technology Data Exchange (ETDEWEB)

    Altman, David A; Forsyth, David R; Smith, Richard E; Singleton, Norman R


    An alignment plate that is attached to a core barrel of a pressurized water reactor and fits within slots within a top plate of a lower core shroud and upper core plate to maintain lateral alignment of the reactor internals. The alignment plate is connected to the core barrel through two vertically-spaced dowel pins that extend from the outside surface of the core barrel through a reinforcement pad and into corresponding holes in the alignment plate. Additionally, threaded fasteners are inserted around the perimeter of the reinforcement pad and into the alignment plate to further secure the alignment plate to the core barrel. A fillet weld also is deposited around the perimeter of the reinforcement pad. To accomodate thermal growth between the alignment plate and the core barrel, a gap is left above, below and at both sides of one of the dowel pins in the alignment plate holes through with the dowel pins pass.

  9. Transport simulation for EBT reactor

    Energy Technology Data Exchange (ETDEWEB)

    Uckan, T.; Uckan, N.A.; Jaeger, E.F.


    Transport simulation and modeling studies for the ELMO Bumpy Torus (EBT) reactor are carried out by using zero-dimensional (0-D) and one-and-one-half-dimensional (1 1/2-D) transport calculations. The time-dependent 0-D model is used for global analysis, whereas the 1 1/2-D radial transport code is used for accurate determination of density, temperature, and ambipolar potential profiles and of the role of these profiles in reactor plasma performance. Analysis with the 1 1/2-D transport code shows that profile effects near the outer edge of the hot electron ring lead to enhanced confinement by at least a factor of 2 to 5 beyond the simple scaling that is obtained from the global analysis. The radial profiles of core plasma density and temperatures (or core pressure) obtained from 1 1/2-D transport calculations are found to be similar to those theoretically required for stability.

  10. Gas-liquid autoxidation reactors

    Energy Technology Data Exchange (ETDEWEB)

    Morbidelli, M.; Paludetto, R.; Carra, S.


    A procedure for the simulation of autoxidation gas-liquid reactors has been developed based both on mathematical models and laboratory experiments. It has been shown that the complex radical chain mechanism of the autoxidation process can be simulated through two global parallel reactions, whose rates are obtained by assuming pseudo-steady-state concentration values for all the radical species involved. Using ethylbenzene autoxidation as a model reaction, an experimental analysis has been performed in order to estimate all the kinetic parameters of the model. The effect of the interaction between gas-liquid mass-transfer phenomena and the complex kinetic mechanism on the overall performance of an autoxidation reactor has been examined in detail within the framework of the liquid film model.

  11. Fast breeder reactor protection system (United States)

    van Erp, J.B.


    Reactor protection is provided for a liquid-metal-fast breeder reactor core by measuring the coolant outflow temperature from each of the subassemblies of the core. The outputs of the temperature sensors from a subassembly region of the core containing a plurality of subassemblies are combined in a logic circuit which develops a scram alarm if a predetermined number of the sensors indicate an over temperature condition. The coolant outflow from a single subassembly can be mixed with the coolant outflow from adjacent subassemblies prior to the temperature sensing to increase the sensitivity of the protection system to a single subassembly failure. Coherence between the sensors can be required to discriminate against noise signals. (Official Gazette)

  12. Reactor vessel lower head integrity

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, A.M.


    On March 28, 1979, the Three Mile Island Unit 2 (TMI-2) nuclear power plant underwent a prolonged small break loss-of-coolant accident that resulted in severe damage to the reactor core. Post-accident examinations of the TMI-2 reactor core and lower plenum found that approximately 19,000 kg (19 metric tons) of molten material had relocated onto the lower head of the reactor vessel. Results of the OECD TMI-2 Vessel Investigation Project concluded that a localized hot spot of approximately 1 meter diameter had existed on the lower head. The maximum temperature on the inner surface of the reactor pressure vessel (RPV) in this region reached 1100{degrees}C and remained at that temperature for approximately 30 minutes before cooling occurred. Even under the combined loads of high temperature and high primary system pressure, the TMI-2 RPV did not fail. (i.e. The pressure varied from about 8.5 to 15 MPa during the four-hour period following the relocation of melt to the lower plenum.) Analyses of RPV failure under these conditions, using state-of-the-art computer codes, predicted that the RPV should have failed via local or global creep rupture. However, the vessel did not fail; and it has been hypothesized that rapid cooling of the debris and the vessel wall by water that was present in the lower plenum played an important role in maintaining RPV integrity during the accident. Although the exact mechanism(s) of how such cooling occurs is not known, it has been speculated that cooling in a small gap between the RPV wall and the crust, and/or in cracks within the debris itself, could result in sufficient cooling to maintain RPV integrity. Experimental data are needed to provide the basis to better understand these phenomena and improve models of RPV failure in severe accident codes.

  13. The ARIES tokamak reactor study

    Energy Technology Data Exchange (ETDEWEB)


    The ARIES study is a community effort to develop several visions of tokamaks as fusion power reactors. The aims are to determine the potential economics, safety, and environmental features of a range of possible tokamak reactors, and to identify physics and technology areas with the highest leverage for achieving the best tokamak reactor. Three ARIES visions are planned, each having a different degree of extrapolation from the present data base in physics and technology. The ARIES-I design assumes a minimum extrapolation from current tokamak physics (e.g., 1st stability) and incorporates technological advances that can be available in the next 20 to 30 years. ARIES-II is a DT-burning tokamak which would operate at a higher beta in the 2nd MHD stability regime. It employs both potential advances in the physics and expected advances in technology and engineering. ARIES-II will examine the potential of the tokamak and the D{sup 3}He fuel cycle. This report is a collection of 14 papers on the results of the ARIES study which were presented at the IEEE 13th Symposium on Fusion Engineering (October 2-6, 1989, Knoxville, TN). This collection describes the ARIES research effort, with emphasis on the ARIES-I design, summarizing the major results, the key technical issues, and the central conclusions.

  14. Actinide transmutation in nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Bultman, J.H.


    An optimization method is developed to maximize the burning capability of the ALMR while complying with all constraints imposed on the design for reliability and safety. This method leads to a maximal transuranics enrichment, which is being limited by constraints on reactivity. The enrichment can be raised by using the neutrons less efficiently by increasing leakage from the fuel. With the developed optimization method, a metallic and an oxide fueled ALMR were optimized. Both reactors perform equally well considering the burning of transuranics. However, metallic fuel has a much higher heat conductivity coefficient, which in general leads to better safety characteristics. In search of a more effective waste transmuter, a modified Molten Salt Reactor was designed. A MSR operates on a liquid fuel salt which makes continuous refueling possible, eliminating the issue of the burnup reactivity loss. Also, a prompt negative reactivity feedback is possible for an overmoderated reactor design, even when the Doppler coefficient is positive, due to the fuel expansion with fuel temperature increase. Furthermore, the molten salt fuel can be reprocessed based on a reduction process which is not sensitive to the short-lived spontaneously fissioning actinides. (orig./HP).

  15. Assessment of the thorium fuel cycle in power reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kasten, P.R.; Homan, F.J.; Allen, E.J.


    A study was conducted at Oak Ridge National Laboratory to evaluate the role of thorium fuel cycles in power reactors. Three thermal reactor systems were considered: Light Water Reactors (LWRs); High-Temperature Gas-Cooled Reactors (HTGRs); and Heavy Water Reactors (HWRs) of the Canadian Deuterium Uranium Reactor (CANDU) type; most of the effort was on these systems. A summary comparing thorium and uranium fuel cycles in Fast Breeder Reactors (FBRs) was also compiled.

  16. Investigation of molten salt fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, Kenichi; Konomura, Mamoru [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan)


    On survey research for practicability strategy of fast reactor (FR) (phase 1), to extract future practicability image candidates of FR from wide options, in addition to their survey and investigation objects of not only solid fuel reactors of conventional research object but also molten salt reactor as a flowing fuel reactor, investigation on concept of molten salt FR plant was carried out. As a part of the first step of the survey research for practicability strategy, a basic concept on plant centered at nuclear reactor facility using chloride molten salt reactor capable of carrying out U-Pu cycle was examined, to perform a base construction to evaluate economical potential for a practical FBR. As a result, a result could be obtained that because of inferior fuel inventory and heat transmission to those in Na cooling reactor in present knowledge, mass of reactor vessel and intermediate heat exchanger were to widely increased to expect reduction of power generation unit price even on considering cheapness of its fuel cycle cost. Therefore, at present step further investigation on concept design of the chloride molten salt reactor plant system is too early in time, and it is at a condition where basic and elementary researches aiming at upgrading of economical efficiency such as wide reduction of fuel inventory, a measure expectable for remarkable rationalization effect of reprocessing system integrating a reactor to a processing facility, and so on. (G.K.)

  17. Molten-Salt Depleted-Uranium Reactor

    CERN Document Server

    Dong, Bao-Guo; Gu, Ji-Yuan


    The supercritical, reactor core melting and nuclear fuel leaking accidents have troubled fission reactors for decades, and greatly limit their extensive applications. Now these troubles are still open. Here we first show a possible perfect reactor, Molten-Salt Depleted-Uranium Reactor which is no above accident trouble. We found this reactor could be realized in practical applications in terms of all of the scientific principle, principle of operation, technology, and engineering. Our results demonstrate how these reactors can possess and realize extraordinary excellent characteristics, no prompt critical, long-term safe and stable operation with negative feedback, closed uranium-plutonium cycle chain within the vessel, normal operation only with depleted-uranium, and depleted-uranium high burnup in reality, to realize with fission nuclear energy sufficiently satisfying humanity long-term energy resource needs, as well as thoroughly solve the challenges of nuclear criticality safety, uranium resource insuffic...

  18. Performance of a multipurpose research electrochemical reactor

    Energy Technology Data Exchange (ETDEWEB)

    Henquin, E.R. [Programa de Electroquimica Aplicada e Ingenieria Electroquimica (PRELINE), Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santiago del Estero 2829, S3000AOM Santa Fe (Argentina); Bisang, J.M., E-mail: [Programa de Electroquimica Aplicada e Ingenieria Electroquimica (PRELINE), Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santiago del Estero 2829, S3000AOM Santa Fe (Argentina)


    Highlights: > For this reactor configuration the current distribution is uniform. > For this reactor configuration with bipolar connection the leakage current is small. > The mass-transfer conditions are closely uniform along the electrode. > The fluidodynamic behaviour can be represented by the dispersion model. > This reactor represents a suitable device for laboratory trials. - Abstract: This paper reports on a multipurpose research electrochemical reactor with an innovative design feature, which is based on a filter press arrangement with inclined segmented electrodes and under a modular assembly. Under bipolar connection, the fraction of leakage current is lower than 4%, depending on the bipolar Wagner number, and the current distribution is closely uniform. When a turbulence promoter is used, the local mass-transfer coefficient shows a variation of {+-}10% with respect to its mean value. The fluidodynamics of the reactor responds to the dispersion model with a Peclet number higher than 10. It is concluded that this reactor is convenient for laboratory research.

  19. Sulfide toxicity kinetics of a uasb reactor

    Directory of Open Access Journals (Sweden)

    D. R. Paula Jr.


    Full Text Available The effect of sulfide toxicity on kinetic parameters of anaerobic organic matter removal in a UASB (up-flow anaerobic sludge blanket reactor is presented. Two lab-scale UASB reactors (10.5 L were operated continuously during 12 months. The reactors were fed with synthetic wastes prepared daily using glucose, ammonium acetate, methanol and nutrient solution. One of the reactors also received increasing concentrations of sodium sulfide. For both reactors, the flow rate of 16 L.d-1 was held constant throughout the experiment, corresponding to a hydraulic retention time of 15.6 hours. The classic model for non-competitive sulfide inhibition was applied to the experimental data for determining the overall kinetic parameter of specific substrate utilization (q and the sulfide inhibition coefficient (Ki. The application of the kinetic parameters determined allows prediction of methanogenesis inhibition and thus the adoption of operating parameters to minimize sulfide toxicity in UASB reactors.

  20. Introduction to the neutron kinetics of nuclear power reactors

    CERN Document Server

    Tyror, J G; Grant, P J


    An Introduction to the Neutron Kinetics of Nuclear Power Reactors introduces the reader to the neutron kinetics of nuclear power reactors. Topics covered include the neutron physics of reactor kinetics, feedback effects, water-moderated reactors, fast reactors, and methods of plant control. The reactor transients following faults are also discussed, along with the use of computers in the study of power reactor kinetics. This book is comprised of eight chapters and begins with an overview of the reactor physics characteristics of a nuclear power reactor and their influence on system design and

  1. Microstructured reactors for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Aartun, Ingrid


    Small scale hydrogen production by partial oxidation (POX) and oxidative steam reforming (OSR) have been studied over Rh-impregnated microchannel Fecralloy reactors and alumina foams. Trying to establish whether metallic microchannel reactors have special advantages for hydrogen production via catalytic POX or OSR with respect to activity, selectivity and stability was of special interest. The microchannel Fecralloy reactors were oxidised at 1000 deg C to form a {alpha}-Al2O3 layer in the channels in order to enhance the surface area prior to impregnation. Kr-BET measurements showed that the specific surface area after oxidation was approximately 10 times higher than the calculated geometric surface area. Approximately 1 mg Rh was deposited in the channels by impregnation with an aqueous solution of RhCl3. Annular pieces (15 mm o.d.,4 mm i.d., 14 mm length) of extruded {alpha}-Al2O3 foams were impregnated with aqueous solutions of Rh(NO3)3 to obtain 0.01, 0.05 and 0.1 wt.% loadings, as predicted by solution uptake. ICP-AES analyses showed that the actual Rh loadings probably were higher, 0.025, 0.077 and 0.169 wt.% respectively. One of the microchannel Fecralloy reactors and all Al2O3 foams were equipped with a channel to allow for temperature measurement inside the catalytic system. Temperature profiles obtained along the reactor axes show that the metallic microchannel reactor is able to minimize temperature gradients as compared to the alumina foams. At sufficiently high furnace temperature, the gas phase in front of the Rh/Al2O3/Frecralloy microchannel reactor and the 0.025 wt.% Rh/Al2O3 foams ignites. Gas phase ignition leads to lower syngas selectivity and higher selectivity to total oxidation products and hydrocarbon by-products. Before ignition of the gas phase the hydrogen selectivity is increased in OSR as compared to POX, the main contribution being the water-gas shift reaction. After gas phase ignition, increased formation of hydrocarbon by

  2. Plasma spark discharge reactor and durable electrode

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young I.; Cho, Daniel J.; Fridman, Alexander; Kim, Hyoungsup


    A plasma spark discharge reactor for treating water. The plasma spark discharge reactor comprises a HV electrode with a head and ground electrode that surrounds at least a portion of the HV electrode. A passage for gas may pass through the reactor to a location proximate to the head to provide controlled formation of gas bubbles in order to facilitate the plasma spark discharge in a liquid environment.

  3. Experimental Breeder Reactor I Preservation Plan

    Energy Technology Data Exchange (ETDEWEB)

    Julie Braun


    Experimental Breeder Reactor I (EBR I) is a National Historic Landmark located at the Idaho National Laboratory, a Department of Energy laboratory in southeastern Idaho. The facility is significant for its association and contributions to the development of nuclear reactor testing and development. This Plan includes a structural assessment of the interior and exterior of the EBR I Reactor Building from a preservation, rather than an engineering stand point and recommendations for maintenance to ensure its continued protection.

  4. Reactor Bolshoi Moshchnosti Kalani; Reacteurs RBMK

    Energy Technology Data Exchange (ETDEWEB)

    Bastien, D. [Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France)


    The Reactor Bolshoi Molshchnosti Kalani (RBMK) are pressure tubes reactor, boiling light water cooled. Exported since 1990 from the ex-USSR, they are today in three independent countries: Russian, Ukraine and Lithuania. Since this date, data exchange with the occident allowed the better knowledge of this reactor type. The design, the technical description (core, fuel, primary system), the safety and the improvement since Chernobyl are detailed. (A.L.B.)

  5. NASA Reactor Facility Hazards Summary. Volume 1 (United States)


    The Lewis Research Center of the National Aeronautics and Space Administration proposes to build a nuclear research reactor which will be located in the Plum Brook Ordnance Works near Sandusky, Ohio. The purpose of this report is to inform the Advisory Committee on Reactor Safeguards of the U. S. Atomic Energy Commission in regard to the design Lq of the reactor facility, the characteristics of the site, and the hazards of operation at this location. The purpose of this research reactor is to make pumped loop studies of aircraft reactor fuel elements and other reactor components, radiation effects studies on aircraft reactor materials and equipment, shielding studies, and nuclear and solid state physics experiments. The reactor is light water cooled and moderated of the MTR-type with a primary beryllium reflector and a secondary water reflector. The core initially will be a 3 by 9 array of MTR-type fuel elements and is designed for operation up to a power of 60 megawatts. The reactor facility is described in general terms. This is followed by a discussion of the nuclear characteristics and performance of the reactor. Then details of the reactor control system are discussed. A summary of the site characteristics is then presented followed by a discussion of the larger type of experiments which may eventually be operated in this facility. The considerations for normal operation are concluded with a proposed method of handling fuel elements and radioactive wastes. The potential hazards involved with failures or malfunctions of this facility are considered in some detail. These are examined first from the standpoint of preventing them or minimizing their effects and second from the standpoint of what effect they might have on the reactor facility staff and the surrounding population. The most essential feature of the design for location at the proposed site is containment of the maximum credible accident.

  6. Heat for industry from nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kikoin, I.K.; Novikov, V.M.

    Two factors which incline nations toward the use of heat from nuclear reactors for industrial use are: 1) exhaustion of cheap fossil fuel resources, and 2) ecological problems associated both with extraction of fossil fuel from the earth and with its combustion. In addition to the usual problems that beset nuclear reactors, special problems associated with using heat from nuclear reactors in various industries are explored.

  7. D-D tokamak reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Evans, K.E. Jr.; Baker, C.C.; Brooks, J.N.; Ehst, D.A.; Finn, P.A.; Jung, J.; Mattas, R.F.; Misra, B.; Smith, D.L.; Stevens, H.C.


    A tokamak D-D reactor design, utilizing the advantages of a deuterium-fueled reactor but with parameters not unnecessarily extended from existing D-T designs, is presented. Studies leading to the choice of a design and initial studies of the design are described. The studies are in the areas of plasma engineering, first-wall/blanket/shield design, magnet design, and tritium/fuel/vacuum requirements. Conclusions concerning D-D tokamak reactors are stated.

  8. Initiating Events for Multi-Reactor Plant Sites

    Energy Technology Data Exchange (ETDEWEB)

    Muhlheim, Michael David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Flanagan, George F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Poore, III, Willis P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)


    Inherent in the design of modular reactors is the increased likelihood of events that initiate at a single reactor affecting another reactor. Because of the increased level of interactions between reactors, it is apparent that the Probabilistic Risk Assessments (PRAs) for modular reactor designs need to specifically address the increased interactions and dependencies.

  9. High Performance Photocatalytic Oxidation Reactor System Project (United States)

    National Aeronautics and Space Administration — Pioneer Astronautics proposes a technology program for the development of an innovative photocatalytic oxidation reactor for the removal and mineralization of...

  10. Savannah River Site reactor safety assessment. Draft

    Energy Technology Data Exchange (ETDEWEB)

    Woody, N.D.; Brandyberry, M.D. [eds.] [Westinghouse Savannah River Co., Aiken, SC (United States); Baker, W.H.; Brandyberry, M.D.; Kearnaghan, D.P.; O`Kula, K.R.; Woody, N.D. [Westinghouse Savannah River Co., Aiken, SC (United States); Amos, C.N.; Weingardt, J.J. [Science Applications International Corp., San Diego, CA (United States)


    This report gives the results of a Savannah River Site (SRS) Production Reactor risk assessment. Measures of adverse consequences to health and safety resulting from representations of severe accidents in SRS reactors are presented. In addition, the report gives a summary of the methods employed to represent these accidents and to assess the resultant consequences. The report is issued to provide timely information to the US Department of Energy (DOE) on the risk of operation of SRS reactors, for insights into severe accident phenomena that contribute to this risk, and in support of improved bases for other Site programs in Heavy Water Reactor safety.

  11. History of fast reactor fuel development

    Energy Technology Data Exchange (ETDEWEB)

    Kittel, J.H.; Frost, B.R.T. (Argonne National Lab., IL (United States)); Mustelier, J.P. (COGEMA, Velizy-Villacoublay (France))


    Most of the first generation of fast reactors that were operated at significant power levels employed solid metal fuels. They were constructed in the United States and United Kingdom in the 1950s and included Experimental Breeder Reactor (EBR)-I and -II operated by Argonne National Laboratory, United States, the Enrico Fermi Reactor operated by the Atomic Power Development Associates, United States and DFR operated by the U.K. Atomic Energy Authority (UKAEA). Their paper tracer pre-development of fast reactor fuel from these early days through the 1980s including ceramic fuels.

  12. Advanced nuclear reactor types and technologies

    Energy Technology Data Exchange (ETDEWEB)

    Ignatiev, V. [ed.; Feinberg, O.; Morozov, A. [Russian Research Centre `Kurchatov Institute`, Moscow (Russian Federation); Devell, L. [Studsvik Eco and Safety AB, Nykoeping (Sweden)


    The document is a comprehensive world-wide catalogue of concepts and designs of advanced fission reactor types and fuel cycle technologies. Two parts have been prepared: Part 1 Reactors for Power Production and Part 2 Heating and Other Reactor Applications. Part 3, which will cover advanced waste management technology, reprocessing and disposal for different nuclear fission options is planned for compilation during 1995. The catalogue was prepared according to a special format which briefly presents the project title, technical approach, development status, application of the technology, reactor type, power output, and organization which developed these designs. Part 1 and 2 cover water cooled reactors, liquid metal fast reactors, gas-cooled reactors and molten salt reactors. Subcritical accelerator-driven systems are also considered. Various reactor applications as power production, heat generation, ship propulsion, space power sources and transmutation of such waste are included. Each project is described within a few pages with the main features of an actual design using a table with main technical data and figure as well as references for additional information. Each chapter starts with an introduction which briefly describes main trends and approaches in this field. Explanations of terms and abbreviations are provided in a glossary.

  13. Supercritical-pressure light water cooled reactors

    CERN Document Server

    Oka, Yoshiaki


    This book focuses on the latest reactor concepts, single pass core and experimental findings in thermal hydraulics, materials, corrosion, and water chemistry. It highlights research on supercritical-pressure light water cooled reactors (SCWRs), one of the Generation IV reactors that are studied around the world. This book includes cladding material development and experimental findings on heat transfer, corrosion and water chemistry. The work presented here will help readers to understand the fundamental elements of reactor design and analysis methods, thermal hydraulics, materials and water

  14. Sandia National Laboratories Medical Isotope Reactor concept.

    Energy Technology Data Exchange (ETDEWEB)

    Coats, Richard Lee; Dahl, James J.; Parma, Edward J., Jr.


    This report describes the Sandia National Laboratories Medical Isotope Reactor and hot cell facility concepts. The reactor proposed is designed to be capable of producing 100% of the U.S. demand for the medical isotope {sup 99}Mo. The concept is novel in that the fuel for the reactor and the targets for the {sup 99}Mo production are the same. There is no driver core required. The fuel pins that are in the reactor core are processed on a 7 to 21 day irradiation cycle. The fuel is low enriched uranium oxide enriched to less than 20% {sup 235}U. The fuel pins are approximately 1 cm in diameter and 30 to 40 cm in height, clad with Zircaloy (zirconium alloy). Approximately 90 to 150 fuel pins are arranged in the core in a water pool {approx}30 ft deep. The reactor power level is 1 to 2 MW. The reactor concept is a simple design that is passively safe and maintains negative reactivity coefficients. The total radionuclide inventory in the reactor core is minimized since the fuel/target pins are removed and processed after 7 to 21 days. The fuel fabrication, reactor design and operation, and {sup 99}Mo production processing use well-developed technologies that minimize the technological and licensing risks. There are no impediments that prevent this type of reactor, along with its collocated hot cell facility, from being designed, fabricated, and licensed today.

  15. NCSU reactor sharing program. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Perez, P.B.


    The Nuclear Reactor Program at North Carolina State University provides the PULSTAR Research Reactor and associated facilities to eligible institutions with support, in part, from the Department of Energy Reactor Sharing Program. Participation in the NCSU Reactor Sharing Program continues to increase steadily with visitors ranging from advance high school physics and chemistry students to Ph.D. level research from neighboring universities. This report is the Final Technical Report for the DOE award reference number DE-FG05-95NE38136 which covers the period September 30, 1995 through September 30, 1996.

  16. Molecular ecology of anaerobic reactor systems

    DEFF Research Database (Denmark)

    Hofman-Bang, H. Jacob Peider; Zheng, D.; Westermann, Peter;


    Anaerobic reactor systems are essential for the treatment of solid and liquid wastes and constitute a core facility in many waste treatment plants. Although much is known about the basic metabolism in different types of anaerobic reactors, little is known about the microbes responsible...... to the abundance of each microbe in anaerobic reactor systems by rRNA probing. This chapter focuses on various molecular techniques employed and problems encountered when elucidating the microbial ecology of anaerobic reactor systems. Methods such as quantitative dot blot/fluorescence in-situ probing using various...

  17. Advances in light water reactor technologies

    CERN Document Server

    Saito, Takehiko; Ishiwatari, Yuki; Oka, Yoshiaki


    ""Advances in Light Water Reactor Technologies"" focuses on the design and analysis of advanced nuclear power reactors. This volume provides readers with thorough descriptions of the general characteristics of various advanced light water reactors currently being developed worldwide. Safety, design, development and maintenance of these reactors is the main focus, with key technologies like full MOX core design, next-generation digital I&C systems and seismic design and evaluation described at length. This book is ideal for researchers and engineers working in nuclear power that are interested

  18. Nanostructured Catalytic Reactors for Air Purification Project (United States)

    National Aeronautics and Space Administration — This SBIR Phase I project proposes the development of lightweight compact nanostructured catalytic reactors for air purification from toxic gaseous organic...

  19. Phosphorus removal in aerated stirred tank reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ghigliazza, R.; Lodi, A.; Rovatti, M. [Inst. of Chemical and Process Engineering ``G.B. Bonino``, Univ. of Genoa (Italy)


    The possibility to obtain biological phosphorus removal in strictly aerobic conditions has been investigated. Experiments, carried out in a continuous stirred tank reactor (CSTR), show the feasibility to obtain phosphorus removal without the anaerobic phase. Reactor performance in terms of phosphorus abatement kept always higher then 65% depending on adopted sludge retention time (SRT). In fact increasing SRT from 5 days to 8 days phosphorus removal and reactor performance increase but overcoming this SRT value a decreasing in reactor efficiency was recorded. (orig.) With 6 figs., 3 tabs., 18 refs.

  20. Sodium fast reactors with closed fuel cycle

    CERN Document Server

    Raj, Baldev; Vasudeva Rao, PR 0


    Sodium Fast Reactors with Closed Fuel Cycle delivers a detailed discussion of an important technology that is being harnessed for commercial energy production in many parts of the world. Presenting the state of the art of sodium-cooled fast reactors with closed fuel cycles, this book:Offers in-depth coverage of reactor physics, materials, design, safety analysis, validations, engineering, construction, and commissioning aspectsFeatures a special chapter on allied sciences to highlight advanced reactor core materials, specialized manufacturing technologies, chemical sensors, in-service inspecti

  1. Autonomous Control of Space Nuclear Reactors Project (United States)

    National Aeronautics and Space Administration — Nuclear reactors to support future robotic and manned missions impose new and innovative technological requirements for their control and protection instrumentation....

  2. Neutron imaging on the VR-1 reactor (United States)

    Crha, J.; Sklenka, L.; Soltes, J.


    Training reactor VR-1 is a low power research reactor with maximal thermal power of 1 kW. The reactor is operated by the Faculty of Nuclear Science and Physical Engineering of the Czech Technical University in Prague. Due to its low power it suits as a tool for education of university students and training of professionals. In 2015, as part of student research project, neutron imaging was introduced as another type of reactor utilization. The low available neutron flux and the limiting spatial and construction capabilities of the reactor's radial channel led to the development of a special filter/collimator insertion inside the channel and choosing a nonstandard approach by placing a neutron imaging plate inside the channel. The paper describes preliminary experiments carried out on the VR-1 reactor which led to first radiographic images. It seems, that due to the reactor construction and low reactor power, the neutron imaging technique on the VR-1 reactor is feasible mainly for demonstration or educational and training purposes.

  3. Microchannel Methanation Reactors Using Nanofabricated Catalysts Project (United States)

    National Aeronautics and Space Administration — Makel Engineering, Inc. (MEI) and the Pennsylvania State University (Penn State) propose to develop and demonstrate a microchannel methanation reactor based on...

  4. Nanostructured Catalytic Reactors for Air Purification Project (United States)

    National Aeronautics and Space Administration — This SBIR Phase II project proposes the development of lightweight compact nanostructured catalytic reactors for air purification from toxic gaseous organic...

  5. Continuous steroid biotransformations in microchannel reactors. (United States)

    Marques, Marco P C; Fernandes, Pedro; Cabral, Joaquim M S; Znidaršič-Plazl, Polona; Plazl, Igor


    The use of microchannel reactor based technologies within the scope of bioprocesses as process intensification and production platforms is gaining momentum. Such trend can be ascribed a particular set of characteristics of microchannel reactors, namely the enhanced mass and heat transfer, combined with easier handling and smaller volumes required, as compared to traditional reactors. In the present work, a continuous production process of 4-cholesten-3-one by the enzymatic oxidation of cholesterol without the formation of any by-product was assessed. The production was carried out within Y-shaped microchannel reactors in an aqueous-organic two-phase system. Substrate was delivered from the organic phase to aqueous phase containing cholesterol oxidase and the product formed partitions back to the organic phase. The aqueous phase was then forced through a plug-flow reactor, containing immobilized catalase. This step aimed at the reduction of hydrogen peroxide formed as a by-product during cholesterol oxidation, to avoid cholesterol oxidase deactivation due to said by-product. This setup was compared with traditional reactors and modes of operation. The results showed that microchannel reactor geometry outperformed traditional stirred tank and plug-flow reactors reaching similar conversion yields at reduced residence time. Coupling the plug-flow reactor containing catalase enabled aqueous phase reuse with maintenance of 30% catalytic activity of cholesterol oxidase while eliminating hydrogen peroxide. A final production of 36 m of cholestenone was reached after 300 hours of operation.

  6. The press and the military government: their relationship in the history of Argentine archaeology (1976-1983. The case of the “La Nación” newspaper

    Directory of Open Access Journals (Sweden)

    Paola Silvia RAMUNDO


    Full Text Available This paper presents a critical and reflexive analysis of the news published between 1976 and 1983 by the newspaper La Nación dealing with Argentine archaeology. Hence, news are considered a tool to study the history of this discipline during a badly reviewed period, evaluating the impact of the socio-historical context on Archaeology in order to determine the degree of public communication of science and the specific role played by this discipline in the construction of the past. Current and past views on Archaeology by the press are analyzed, considering these written documents an opinion former mass media.

  7. La norma argentina de construcción de tesauros IRAM 32057: necesidad de actualización. 1. El vocabulario controlado The Argentine Standard for Thesaurus Construction IRAM 32057: a Need for Updating. 1. The Controlled Vocabulary

    Directory of Open Access Journals (Sweden)

    Ana M. Martínez


    Full Text Available Se comparó la norma argentina de construcción de tesauros monolingües (IRAM 32057:1983 con las últimas ediciones de la norma internacional (ISO 2788:1986, las normas nacionales de España (UNE 50106:1990, Estados Unidos (Z39.19:2005 y Gran Bretaña (BSI 8723-2:2005b, así como diversos manuales reconocidos. Se analizaron tanto el alcance y los aspectos formales de la norma, como los conceptos referidos a la normativa sobre el vocabulario controlado. El alcance de la norma argentina se limita a la construcción de tesauros monolingües, mientras que las nuevas normas estadounidense y británica cubren también diferentes sistemas de organización del conocimiento. En relación con los aspectos formales, la norma argentina carece de tabla de contenido, índice analítico, glosario, bibliografía y algunas secciones y anexos, contando además con muy pocos ejemplos. En cuanto a los aspectos conceptuales, algunas definiciones son incorrectas o desactualizadas, lo mismo que algunas de las recomendaciones para el control del vocabulario. Se concluye que la norma argentina debería revisarse y actualizarse de conformidad con las normas publicadas recientemente y la norma ISO 25964 aún en preparación.The Argentine standard for the construction of monolingual thesaurus (IRAM 32057:1983 was compared with the last editions of the international standard (ISO 2788:1986, and the national standards of Spain (UNE 50106:1990, United States (Z39.19:2005, and Great Britain (BSI 8723-2:2005b, and very well known manuals. The scope and formal issues were analyzed, as well as the conceptual issues for controlled vocabulary. The scope of the Argentine standard is limited to the construction of monolingual thesauri, while the new North-American and British standards also cover different knowledge organization systems. In relation to the formal issues, the Argentine standard has not table of content, analytical index, glossary, bibliography and some sections and

  8. Molecular identification, morphological characterization and new insights into the ecology of larval Pseudoterranova cattani in fishes from the Argentine coast with its differentiation from the Antarctic species, P. decipiens sp. E (Nematoda: Anisakidae). (United States)

    Timi, Juan T; Paoletti, Michela; Cimmaruta, Roberta; Lanfranchi, Ana L; Alarcos, Ana J; Garbin, Lucas; George-Nascimento, Mario; Rodríguez, Diego H; Giardino, Gisela V; Mattiucci, Simonetta


    Larvae of the genus Pseudoterranova constitute a risk for human health when ingested through raw or undercooked fish. They can provoke pseudoterranovosis in humans, a fish-borne zoonotic disease whose pathogenicity varies with the species involved, making their correct specific identification a necessary step in the knowledge of this zoonosis. Larvae of Pseudoterranova decipiens s.l. have been reported in several fish species from off the Argentine coasts; however, there are no studies dealing with their specific identification in this region. Here, a genetic identification and morphological characterization of larval Pseudoterranova spp. from three fish species sampled from Argentine waters and from Notothenia coriiceps from Antarctic waters was carried out. Larvae were sequenced for their genetic/molecular identification, including the mitochondrial cytochrome c oxidase subunit II (mtDNA cox2), the first (ITS-1) and the second (ITS-2) internal transcribed spacers of the nuclear ribosomal DNA, and compared with all species of the P. decipiens (sensu lato) species complex (sequences available in GenBank). Further, adults of Pseudoterranova spp. from the definitive host, the southern sea lion, Otaria flavescens, from Argentine and Chilean coasts were sequenced at the same genes. The sequences obtained at the ITS-1 and ITS-2 genes from all the larvae examined from fish of Argentine waters, as well as the adult worms, matched 100% the sequences for the species P. cattani. The sequences obtained at mtDNA cox2 gene for Antarctic larvae matched 99% those available in GenBank for the sibling P. decipiens sp. E. Both MP and BI phylogenetic trees strongly supported P. cattani and P. decipiens sp. E as two distinct phylogenetic lineages and depicted the species P. decipiens sp. E as sister taxon to the remaining taxa of the P. decipiens complex. Larval morphometry was similar between specimens of P. cattani from Argentina, but significantly different from those of P

  9. Effects of cigarette smoking on early arthritis: a cross-sectional study-data from the Argentine Consortium for Early Arthritis (CONAART). (United States)

    Haye Salinas, María Jezabel; Retamozo, Soledad; Alvarez, Ana Cecilia; Maldonado Ficco, Hernán; Dal Pra, Fernando; Citera, Gustavo; Benegas, Mariana; Chaparro del Moral, Rafael; Rillo, Oscar; Secco, Anastasia; Marino Claverie, Lucila; Catalan Pellet, Antonio; Marcos, Josefina; García, Mercedes Argentina; Marcos, Juan Carlos; Barbaglia, Ana; Bellomio, Verónica; Berman, Alberto; Quiroz, Cristian; Soriano, Enrique R; Ceccato, Federico; Paira, Sergio; Vazquez, Doralia; Juarez, Vicente Ricardo; Velozo, Edson Javier; Salvatierra, Gabriela; Caeiro, Francisco


    Our objective was to analyze the effects of cigarette smoking on disease activity, functional capacity, radiographic damage, serology and presence of extraarticular manifestations in patients with rheumatoid arthritis and undifferentiated arthritis. This is a cross-sectional study of 1,305 patients (729 with rheumatoid arthritis and 576 with undifferentiated arthritis) from CONAART, the Argentine Consortium for Early Arthritis that includes patients older than 16 years with <2 years of disease. Sociodemographic data, clinical characteristics of the disease and smoking history were collected. In patients with rheumatoid arthritis the disease activity score of 28 joints was 5.4 ± 1.3 in current smokers, 5.2 ± 1.4 in former smokers and 5.1 ± 1.4 in never smokers (p = 0.011). The simple erosion narrowing score was higher in current smokers and former smokers than in never smokers (M 14.0, R Q 6.0-21.0; M 15.0, R Q 7.0-24.0; M 10.0, R Q 5.0-17.0; p = 0.006). Current smokers had higher rheumatoid factor titer (M 160.0, R Q 80.0-341.0) than former smokers (M 146.8, R Q 6.03-255.5) and never smokers (M 15.0, R Q 9.0-80.0) (p = 0.004). The variable independently associated with tobacco exposure was simple erosion narrowing score (OR = 1.03, 95 % CI 1.00-1.05; p = 0.012). In patients with undifferentiated arthritis, an association between smoking status and parameters of activity or radiographic damage was not observed. Neither was tobacco exposure related to the presence of extraarticular manifestations or to the degree of disability in any of the two groups of patients. No relation was found between disease activity and severity, and number of packs smoked per year. Tobacco.

  10. Argentine – Chili : Une si longue frontière Argentina – Chile: Such a long boundary Argentina – Chile: Una frontera tan larga

    Directory of Open Access Journals (Sweden)

    Sébastien Velut


    Full Text Available Cet article aborde l’intégration sud américaine à partir de l’examen de la très longue frontière entre le Chili et l’Argentine et de sa configuration matérielle. Son tracé, des traités internationaux au terrain, a été une opération compliquée étalée sur plus d’un siècle. La limite est recoupée par les grands itinéraires transcontinentaux, qui jouent un rôle majeur dans les projets politiques d’intégration sud américaine. Les dispositifs de passages, les réseaux urbains et routiersThis paper explores South American regional integration from the vantage point of the very long boundary between Chile and Argentina and is material configurations. The drawing of this very long border, from international treaties to field, was a complex operation lasting more than one century. The limit is intersected by transcontinental itineraries that play a major role in the political projects of South American integration. Crossing devices, urban and road networks and exchanges define regional units.Este artículo estudia la integración sur Americana a partir de la muy larga frontera entre Chile y Argentina y sus configuraciones materiales. El dibujo de la frontera, desde los tratados internacionales hasta el terreno, ha sido una operación compleja que se extendió por más de un siglo. El límite se encuentra recortado por los grandes ejes transcontinentales, que juegan un papel central en los proyectos políticos de integración sur-americana. Los dispositivos de intercambio, las redes urbanas y de caminos y los intercambios definen unidades regionales.

  11. A comparative study of Trypanosoma cruzi infection in sylvatic mammals from a protected and a disturbed area in the Argentine Chaco. (United States)

    Orozco, M M; Enriquez, G F; Cardinal, M V; Piccinali, R V; Gürtler, R E


    Understanding the complex epidemiology of Trypanosoma cruzi transmission cycles requires comparative studies in widely different environments. We assessed the occurrence of T. cruzi infection in sylvatic mammals, their infectiousness to the vector, and parasite genotypes in a protected area of the Argentine Chaco, and compared them with information obtained similarly in a nearby disturbed area. A total of 278 mammals from >23 species in the protected area were diagnosed for T. cruzi infection using xenodiagnosis, kDNA-PCR and nuclear satellite DNA-PCR (SAT) from blood samples. The relative abundance and species composition differed substantially between areas. Didelphis albiventris opossums were less abundant in the protected area; had a significantly lower body mass index, and a stage structure biased toward earlier stages. The capture of armadillos was lower in the protected area. The composite prevalence of T. cruzi infection across host species was significantly lower in the protected area (11.1%) than in the disturbed area (22.1%), and heterogeneous across species groups. The prevalence of infection in D. albiventris and Thylamys pusilla opossums was significantly lower in the protected area (nil for D. albiventris), whereas infection in sigmodontine rodents was three times higher in the protected area (17.5 versus 5.7%). Parasite isolates from the two xenodiagnosis-positive mammals (1 Dasypus novemcinctus and 1 Conepatus chinga) were typed as TcIII; both specimens were highly infectious to Triatoma infestans. Fat-tailed opossums, bats and rodents were kDNA-PCR-positive and xenodiagnosis-negative. Desmodus rotundus and Myotis bats were found infected with T. cruzi for the first time in the Gran Chaco.

  12. The effects of nitric oxide cooling and the photodissociation of molecular oxygen on the thermosphere/ionosphere system over the Argentine Islands

    Directory of Open Access Journals (Sweden)

    G. D. Wells

    Full Text Available In the past the global, fully coupled, time-dependent mathematical model of the Earth's thermosphere/ionosphere/plasmasphere (CTIP has been unable to reproduce accurately observed values of the maximum plasma frequency, foF2, at extreme geophysical locations such as the Argentine Islands during the summer solstice where the ionosphere remains in sunlight throughout the day. This is probably because the seasonal dependence of thermospheric cooling by 5.3 µm nitric oxide has been neglected and the photodissociation of O2 and heating rate calculations have been over-simplified. Now we have included an up-to-date calculation of the solar EUV and UV thermospheric heating rate, coupled with a new calculation of a diurnally varying O2 photodissociation rate, in the model. Seasonally dependent 5.3 µm nitric oxide cooling is also included. With these important improvements, it is found that model values of foF2 are in substantially better agreement with observation. The height of the F2-peak is reduced throughout the day, but remains within acceptable limits of values derived from observation, except at around 0600 h LT. We also carry out two studies of the sensitivity of the upper atmosphere to changes in the magnitude of nitric oxide cooling and photodissociation rates. We find that hmF2 increases with increased heating, whilst foF2 falls. The converse is true for an increase in the cooling rate. Similarly increasing the photodissociation rate increases both hmF2 and foF2. These changes are explained in terms of changes in the neutral temperature, composition and neutral wind.

  13. Reactors for nuclear electric propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Buden, D.; Angelo, J.A. Jr.


    Propulsion is the key to space exploitation and power is the key to propulsion. This paper examines the role of nuclear fission reactors as the primary power source for high specific impulse electric propulsion systems for space missions of the 1980s and 1990s. Particular mission applications include transfer to and a reusable orbital transfer vehicle from low-Earth orbit to geosynchronous orbit, outer planet exploration and reconnaissance missions, and as a versatile space tug supporting lunar resource development. Nuclear electric propulsion is examined as an indispensable component in space activities of the next two decades.

  14. Biodegradation of MTBE in reactors

    DEFF Research Database (Denmark)

    Waul, Christopher Kevin


    The fuel oxygenate methyl tert-butyl ether (MTBE) was first introduced in the 1970’s to improve gasoline combustion efficiency and reduce emission of harmful gases. However, it has caused groundwater contamination in Denmark and in many locations worldwide through accidental releases from leaking...... such as ammonium or benzene, toluene, ethyl benzene and xylene (BTEX) oxidizers, which can be present together in a single system. The competition resulted in reduced and/or delayed degradation of MTBE when there were limitations of oxygen or space in the reactor. The fraction of biologically active (BA) MTBE...

  15. Coupled reactor kinetics and heat transfer model for heat pipe cooled reactors (United States)

    Wright, Steven A.; Houts, Michael


    Heat pipes are often proposed as cooling system components for small fission reactors. SAFE-300 and STAR-C are two reactor concepts that use heat pipes as an integral part of the cooling system. Heat pipes have been used in reactors to cool components within radiation tests (Deverall, 1973); however, no reactor has been built or tested that uses heat pipes solely as the primary cooling system. Heat pipe cooled reactors will likely require the development of a test reactor to determine the main differences in operational behavior from forced cooled reactors. The purpose of this paper is to describe the results of a systems code capable of modeling the coupling between the reactor kinetics and heat pipe controlled heat transport. Heat transport in heat pipe reactors is complex and highly system dependent. Nevertheless, in general terms it relies on heat flowing from the fuel pins through the heat pipe, to the heat exchanger, and then ultimately into the power conversion system and heat sink. A system model is described that is capable of modeling coupled reactor kinetics phenomena, heat transfer dynamics within the fuel pins, and the transient behavior of heat pipes (including the melting of the working fluid). This paper focuses primarily on the coupling effects caused by reactor feedback and compares the observations with forced cooled reactors. A number of reactor startup transients have been modeled, and issues such as power peaking, and power-to-flow mismatches, and loading transients were examined, including the possibility of heat flow from the heat exchanger back into the reactor. This system model is envisioned as a tool to be used for screening various heat pipe cooled reactor concepts, for designing and developing test facility requirements, for use in safety evaluations, and for developing test criteria for in-pile and out-of-pile test facilities. .

  16. Compound cryopump for fusion reactors

    CERN Document Server

    Kovari, M; Shephard, T


    We reconsider an old idea: a three-stage compound cryopump for use in fusion reactors such as DEMO. The helium "ash" is adsorbed on a 4.5 K charcoal-coated surface, while deuterium and tritium are adsorbed at 15-22 K on a second charcoal-coated surface. The helium is released by raising the first surface to ~30 K. In a separate regeneration step, deuterium and tritium are released at ~110 K. In this way, the helium can be pre-separated from other species. In the simplest design, all three stages are in the same vessel, with a single valve to close the pump off from the tokamak during regeneration. In an alternative design, the three stages are in separate vessels, connected by valves, allowing the stages to regenerate without interfering with each other. The inclusion of the intermediate stage would not affect the overall pumping speed significantly. The downstream exhaust processing system could be scaled down, as much of the deuterium and tritium could be returned directly to the reactor. This could reduce ...

  17. K-East and K-West Reactors (United States)

    Federal Laboratory Consortium — Hanford's "sister reactors", the K-East and the K-West Reactors, were built side-by-side in the early 1950's. The two reactors went operational within four months of...

  18. A new MTR fuel for a new MTR reactor: UMo for the Jules Horowitz reactor

    Energy Technology Data Exchange (ETDEWEB)

    Guigon, B. [CEA Cadarache, Dir. de l' Energie Nucleaire DEN, Reacteur Jules Horowitz, 13 - Saint-Paul-lez-Durance (France); Vacelet, H. [Compagnie pour l' Etude et la Realisation de Combustibles Atomiques, CERCA, Etablissement de Romans, 26 (France); Dornbusch, D. [Technicatome, Service d' Architecture Generale, 13 - Aix-en-Provence (France)


    Within some years, the Jules Horowitz Reactor will be the only working experimental reactor (material and fuel testing reactor) in France. It will have to provide facilities for a wide range of needs: from activation analysis to power reactor fuel qualification. In this paper will be presented the main characteristics of the Jules Horowitz Reactor: its total power, neutron flux, fuel element... Safety criteria will be explained. Finally merits and disadvantages of UMo compared to the standard U{sub 3}Si{sub 2} fuel will be discussed. (authors)

  19. Annual report on JEN-1 reactor; Informe periodico del Reactor JEN-1 correspondiente al ano 1971

    Energy Technology Data Exchange (ETDEWEB)

    Montes, J.


    In the annual report on the JEN-1 reactor the main features of the reactor operations and maintenance are described. The reactor has been critical for 1831 hours, what means 65,8% of the total working time. Maintenance and pool water contamination have occupied the rest of the time. The maintenance schedule is shown in detail according to three subjects. The main failures and reactor scrams are also described. The daily maximum values of the water activity are given so as the activity of the air in the reactor hall. (Author)

  20. Selective purge for hydrogenation reactor recycle loop (United States)

    Baker, Richard W.; Lokhandwala, Kaaeid A.


    Processes and apparatus for providing improved contaminant removal and hydrogen recovery in hydrogenation reactors, particularly in refineries and petrochemical plants. The improved contaminant removal is achieved by selective purging, by passing gases in the hydrogenation reactor recycle loop or purge stream across membranes selective in favor of the contaminant over hydrogen.

  1. Radiochemical problems of fusion reactors. 1. Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Crespi, M.B.A.


    A list of fusion reactor candidate materials is given, for use in connection with blanket structure, breeding, moderation, neutron multiplication, cooling, magnetic field generation, electrical insulation and radiation shielding. The phenomena being studied for each group of materials are indicated. Suitable irradiation test facilities are discussed under the headings (1) accelerator-based neutron sources, (2) fission reactors, and (3) ion accelerators.

  2. Advanced tokamak concepts and reactor designs

    NARCIS (Netherlands)

    Oomens, A. A. M.


    From a discussion of fusion reactor designs based on today's well-established experience gained in the operation of large tokamaks, it is concluded that such reactors are economically not attractive. The physics involved in the various options for concept improvement is described, some examples

  3. Startup of an industrial adiabatic tubular reactor

    NARCIS (Netherlands)

    Verwijs, J.W.; Berg, van den H.; Westerterp, K.R.


    The dynamic behaviour of an adiabatic tubular plant reactor during the startup is demonstrated, together with the impact of a feed-pump failure of one of the reactants. A dynamic model of the reactor system is presented, and the system response is calculated as a function of experimentally-determine

  4. Rotor for a pyrolysis centrifuge reactor

    DEFF Research Database (Denmark)


    The present invention relates to a rotor for a pyrolysis centrifuge reactor, said rotor comprising a rotor body having a longitudinal centre axis, and at least one pivotally mounted blade being adapted to pivot around a pivot axis under rotation of the rotor body around the longitudinal centre axis....... Moreover, the present invention relates to a pyrolysis centrifuge reactor applying such a rotor....

  5. Helix reactor: great potential for flow chemistry

    NARCIS (Netherlands)

    Geerdink, P.; Runstraat, A. van den; Roelands, C.P.M.; Goetheer, E.L.V.


    The Helix reactor is highly suited for precise reaction control based on good hydrodynamics. The hydrodynamics are controlled by the Dean vortices, which create excellent heat transfer properties, approach plug flow and avoid turbulence. The flexibility of this reactor has been demonstrated using a

  6. The Design of a Nuclear Reactor

    Indian Academy of Sciences (India)


    The aim of this largely pedagogical article is toemploy pre-college physics to arrive at an understanding of a system as complex as a nuclear reactor. We focus on three key issues: the fuelpin, the moderator, and lastly the dimensions ofthe nuclear reactor.

  7. Design of an organic simplified nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shirvan, Koroush [Dept. of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge (United States); Forrest, Eric [Primary Standards Laboratory, Sandia National Laboratories, Albuquerque (United States)


    Numerous advanced reactor concepts have been proposed to replace light water reactors ever since their establishment as the dominant technology for nuclear energy production. While most designs seek to improve cost competitiveness and safety, the implausibility of doing so with affordable materials or existing nuclear fuel infrastructure reduces the possibility of near-term deployment, especially in developing countries. The organic nuclear concept, first explored in the 1950s, offers an attractive alternative to advanced reactor designs being considered. The advent of high temperature fluids, along with advances in hydrocracking and reforming technologies driven by the oil and gas industries, make the organic concept even more viable today. We present a simple, cost-effective, and safe small modular nuclear reactor for offshore underwater deployment. The core is moderated by graphite, zirconium hydride, and organic fluid while cooled by the organic fluid. The organic coolant enables operation near atmospheric pressure and use of plain carbon steel for the reactor tank and primary coolant piping system. The core is designed to mitigate the coolant degradation seen in early organic reactors. Overall, the design provides a power density of 40 kW/L, while reducing the reactor hull size by 40% compared with a pressurized water reactor while significantly reducing capital plant costs.

  8. Technical features of the MR reactor decommissioning

    Directory of Open Access Journals (Sweden)

    Craig David


    Full Text Available This paper presents a preliminary technical design for the dismantling of the MR reactor. The goal of the design is the removal of reactor components allowing the re-use of the building for a different nuclear related purpose. The sequence of segmentation procedures is established. Considerations on the size reduction and tooling are presented.

  9. The First Reactor, 40th Anniversary (rev.)

    Energy Technology Data Exchange (ETDEWEB)

    Allardice, Corbin; Trapnell, Edward R; Fermi, Enrico; Fermi, Laura; Williams, Robert C


    This booklet, an updated version of the original booklet describing the first nuclear reactor, was written in honor of the 40th anniversary of the first reactor or "pile". It is based on firsthand accounts told to Corbin Allardice and Edward R. Trapnell, and includes recollections of Enrico and Laura Fermi.


    Balent, R.


    This patent describes a method of obtaining a flatter flux and more uniform power generation across the core of a nuclear reactor. The method comprises using moderator elements having differing moderating strength. The elements have an increasing amount of the better moderating material as a function of radial and/or axial distance from the reactor core center. (AEC)

  11. Parametric sensitivity and runaway in tubular reactors

    Energy Technology Data Exchange (ETDEWEB)

    Morbidelli, M.; Varma, A.


    Parametric sensitivity of tubular reactors is analyzed to provide critical values of the heat of reaction and heat transfer parameters defining runaway and stable operations for all positive-order exothermic reactions with finite activation energies, and for all reactor inlet temperatures. Evaluation of the critical values does not involve any trial and error.

  12. Microbial degradation of MTBE in reactors

    DEFF Research Database (Denmark)

    Waul, Christopher Kevin; Arvin, Erik; Schmidt, Jens Ejbye


    , toluene, ethylbenzene and xylenes, may reduce the removal rates of MTBE, or prevent its removal in reactors. With mathematical modelling, the long startup time required for some MTBE degrading reactors could be predicted. Long startup times of up to 200 days were due to the low maximum growth rate...

  13. Design of an Organic Simplified Nuclear Reactor

    Directory of Open Access Journals (Sweden)

    Koroush Shirvan


    Full Text Available Numerous advanced reactor concepts have been proposed to replace light water reactors ever since their establishment as the dominant technology for nuclear energy production. While most designs seek to improve cost competitiveness and safety, the implausibility of doing so with affordable materials or existing nuclear fuel infrastructure reduces the possibility of near-term deployment, especially in developing countries. The organic nuclear concept, first explored in the 1950s, offers an attractive alternative to advanced reactor designs being considered. The advent of high temperature fluids, along with advances in hydrocracking and reforming technologies driven by the oil and gas industries, make the organic concept even more viable today. We present a simple, cost-effective, and safe small modular nuclear reactor for offshore underwater deployment. The core is moderated by graphite, zirconium hydride, and organic fluid while cooled by the organic fluid. The organic coolant enables operation near atmospheric pressure and use of plain carbon steel for the reactor tank and primary coolant piping system. The core is designed to mitigate the coolant degradation seen in early organic reactors. Overall, the design provides a power density of 40 kW/L, while reducing the reactor hull size by 40% compared with a pressurized water reactor while significantly reducing capital plant costs.

  14. Verification of Remote Inspection Techniques for Reactor Internal Structures of Liquid Metal Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Young Sang; Lee, Jae Han


    The reactor internal structures and components of a liquid metal reactor (LMR) are submerged in hot sodium of reactor vessel. The division 3 of ASME code section XI specifies the visual inspection as major in-service inspection (ISI) methods of reactor internal structures and components. Reactor internals of LMR can not be visually examined due to opaque liquid sodium. The under-sodium viewing techniques using an ultrasonic wave should be applied for the visual inspection of reactor internals. Recently, an ultrasonic waveguide sensor with a strip plate has been developed for an application to the under-sodium inspection. In this study, visualization technique, ranging technique and monitoring technique have been suggested for the remote inspection of reactor internals by using the waveguide sensor. The feasibility of these remote inspection techniques using ultrasonic waveguide sensor has been evaluated by an experimental verification.

  15. State space modeling of reactor core in a pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ashaari, A.; Ahmad, T.; M, Wan Munirah W. [Department of Mathematical Science, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Shamsuddin, Mustaffa [Institute of Ibnu Sina, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Abdullah, M. Adib [Swinburne University of Technology, Faculty of Engineering, Computing and Science, Jalan Simpang Tiga, 93350 Kuching, Sarawak (Malaysia)


    The power control system of a nuclear reactor is the key system that ensures a safe operation for a nuclear power plant. However, a mathematical model of a nuclear power plant is in the form of nonlinear process and time dependent that give very hard to be described. One of the important components of a Pressurized Water Reactor is the Reactor core. The aim of this study is to analyze the performance of power produced from a reactor core using temperature of the moderator as an input. Mathematical representation of the state space model of the reactor core control system is presented and analyzed in this paper. The data and parameters are taken from a real time VVER-type Pressurized Water Reactor and will be verified using Matlab and Simulink. Based on the simulation conducted, the results show that the temperature of the moderator plays an important role in determining the power of reactor core.

  16. State space modeling of reactor core in a pressurized water reactor (United States)

    Ashaari, A.; Ahmad, T.; Shamsuddin, Mustaffa; M, Wan Munirah W.; Abdullah, M. Adib


    The power control system of a nuclear reactor is the key system that ensures a safe operation for a nuclear power plant. However, a mathematical model of a nuclear power plant is in the form of nonlinear process and time dependent that give very hard to be described. One of the important components of a Pressurized Water Reactor is the Reactor core. The aim of this study is to analyze the performance of power produced from a reactor core using temperature of the moderator as an input. Mathematical representation of the state space model of the reactor core control system is presented and analyzed in this paper. The data and parameters are taken from a real time VVER-type Pressurized Water Reactor and will be verified using Matlab and Simulink. Based on the simulation conducted, the results show that the temperature of the moderator plays an important role in determining the power of reactor core.

  17. Precision spectroscopy with reactor anti-neutrinos

    CERN Document Server

    Huber, P; Huber, Patrick; Schwetz, Thomas


    In this work we present an accurate parameterization of the anti-neutrino flux produced by the isotopes 235U, 239Pu and 241Pu in nuclear reactors. We determine the coefficients of this parameterization, as well as their covariance matrix, by performing a fit to spectra inferred from experimentally measured beta spectra. Subsequently we show that flux shape uncertainties play only a minor role in the KamLAND experiment, however, we find that future reactor neutrino experiments to measure the mixing angle $\\theta_{13}$ are sensitive to the fine details of the reactor neutrino spectra. Finally, we investigate the possibility to determine the isotopic composition in nuclear reactors through an anti-neutrino measurement. We find that with a 3 month exposure of a one ton detector the isotope fractions and the thermal reactor power can be determined at a few percent accuracy, which may open the possibility of an application for safeguard or non-proliferation objectives.

  18. Scanning tunneling microscope assembly, reactor, and system (United States)

    Tao, Feng; Salmeron, Miquel; Somorjai, Gabor A


    An embodiment of a scanning tunneling microscope (STM) reactor includes a pressure vessel, an STM assembly, and three spring coupling objects. The pressure vessel includes a sealable port, an interior, and an exterior. An embodiment of an STM system includes a vacuum chamber, an STM reactor, and three springs. The three springs couple the STM reactor to the vacuum chamber and are operable to suspend the scanning tunneling microscope reactor within the interior of the vacuum chamber during operation of the STM reactor. An embodiment of an STM assembly includes a coarse displacement arrangement, a piezoelectric fine displacement scanning tube coupled to the coarse displacement arrangement, and a receiver. The piezoelectric fine displacement scanning tube is coupled to the coarse displacement arrangement. The receiver is coupled to the piezoelectric scanning tube and is operable to receive a tip holder, and the tip holder is operable to receive a tip.

  19. Reactor assessments of advanced bumpy torus configurations

    Energy Technology Data Exchange (ETDEWEB)

    Uckan, N.A.; Owen, L.W.; Spong, D.A.; Miller, R.L.; Ard, W.B.; Pipkins, J.F.; Schmitt, R.J.


    Recently, several innovative approaches were introduced for enhancing the performance of the basic ELMO Bumpy Torus (EBT) concept and for improving its reactor potential. These include planar racetrack and square geometries, Andreoletti coil systems, and bumpy torus-stellarator hybrids (which include twisted racetrack and helical axis stellarator - snakey torus). Preliminary evaluations of reactor implications of each approach have been carried out based on magnetics (vacuum) calculations, transport and scaling relationships, and stability properties deduced from provisional configurations that implement the approach but are not necessarily optimized. Further optimization is needed in all cases to evaluate the full potential of each approach. Results of these studies indicate favorable reactor projections with a significant reduction in reactor physical size as compared to conventional EBT reactor designs carried out in the past.

  20. Reactivity control assembly for nuclear reactor. [LMFBR (United States)

    Bollinger, L.R.


    This invention, which resulted from a contact with the United States Department of Energy, relates to a control mechanism for a nuclear reactor and, more particularly, to an assembly for selectively shifting different numbers of reactivity modifying rods into and out of the core of a nuclear reactor. It has been proposed heretofore to control the reactivity of a breeder reactor by varying the depth of insertion of control rods (e.g., rods containing a fertile material such as ThO/sub 2/) in the core of the reactor, thereby varying the amount of neutron-thermalizing coolant and the amount of neutron-capturing material in the core. This invention relates to a mechanism which can advantageously be used in this type of reactor control system.

  1. Power Control Method for Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Baang, Dane; Suh, Yongsuk; Park, Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    Considering safety-oriented design concept and other control environment, we developed a simple controller that provides limiting function of power change- rate as well as fine tracking performance. The design result has been well-proven via simulation and actual application to a TRIGA-II type research reactor. The proposed controller is designed to track the PDM(Power Demand) from operator input as long as maintaining the power change rate lower than a certain value for stable reactor operation. A power control method for a TRIGA-II type research reactor has been designed, simulated, and applied to actual reactor. The control performance during commissioning test shows that the proposed controller provides fine control performance for various changes in reference values (PDM), even though there is large measurement noise from neutron detectors. The overshoot at low power level is acceptable in a sense of reactor operation.

  2. Ceramic oxygen transport membrane array reactor and reforming method (United States)

    Kelly, Sean M.; Christie, Gervase Maxwell; Robinson, Charles; Wilson, Jamie R.; Gonzalez, Javier E.; Doraswami, Uttam R.


    The invention relates to a commercially viable modular ceramic oxygen transport membrane reforming reactor configured using repeating assemblies of oxygen transport membrane tubes and catalytic reforming reactors.

  3. Psicanálise e marxismo: a fratura da Associação Psicanalítica Argentina (1971 Psychoanalysis and Marxism: the splitting of the Argentine Psychoanalytic Association (1971

    Directory of Open Access Journals (Sweden)

    Hugo Vezzetti


    Full Text Available O artigo aborda um acontecimento inusual em que se cruzam a história da psicanálise e a da esquerda marxista: a renúncia, por motivos ideológicos, de dois grupos à associação argentina. O trabalho procura ir além do testemunho dos protagonistas e interrogar os relatos fixados sobre o acontecimento. Para isso explora, a partir dos anos de 1960, as condições e as alternativas desse encontro entre Freud e Marx, particularmente no âmbito universitário (a Faculdade de Filosofia e Letras da UBA, na organização corporativa profissional (a Federação Argentina de Psiquiatras e em organizações políticas da época (o Partido Comunista e o peronismo revolucionário.The article looks at an unusual event in which the history of psychoanalysis and that of the Marxist left intersected: the resignation of two groups from the Argentine association on ideological grounds. Looking to go beyond the testimony of the protagonists and interrogate the accounts focusing on the event, the text explores the conditions and alternatives of this encounter between Freud and Marx from the 1960s onwards, particularly in academia (the Faculty of Philosophy and Letters of the UBA, in a professional organization (the Argentine Federation of Psychiatrists and in political organizations active during the period (the Communist Party and revolutionary Peronism.

  4. Fast Spectrum Molten Salt Reactor Options

    Energy Technology Data Exchange (ETDEWEB)

    Gehin, Jess C [ORNL; Holcomb, David Eugene [ORNL; Flanagan, George F [ORNL; Patton, Bruce W [ORNL; Howard, Rob L [ORNL; Harrison, Thomas J [ORNL


    During 2010, fast-spectrum molten-salt reactors (FS-MSRs) were selected as a transformational reactor concept for light-water reactor (LWR)-derived heavy actinide disposition by the Department of Energy-Nuclear Energy Advanced Reactor Concepts (ARC) program and were the subject of a preliminary scoping investigation. Much of the reactor description information presented in this report derives from the preliminary studies performed for the ARC project. This report, however, has a somewhat broader scope-providing a conceptual overview of the characteristics and design options for FS-MSRs. It does not present in-depth evaluation of any FS-MSR particular characteristic, but instead provides an overview of all of the major reactor system technologies and characteristics, including the technology developments since the end of major molten salt reactor (MSR) development efforts in the 1970s. This report first presents a historical overview of the FS-MSR technology and describes the innovative characteristics of an FS-MSR. Next, it provides an overview of possible reactor configurations. The following design features/options and performance considerations are described including: (1) reactor salt options-both chloride and fluoride salts; (2) the impact of changing the carrier salt and actinide concentration on conversion ratio; (3) the conversion ratio; (4) an overview of the fuel salt chemical processing; (5) potential power cycles and hydrogen production options; and (6) overview of the performance characteristics of FS-MSRs, including general comparative metrics with LWRs. The conceptual-level evaluation includes resource sustainability, proliferation resistance, economics, and safety. The report concludes with a description of the work necessary to begin more detailed evaluation of FS-MSRs as a realistic reactor and fuel cycle option.

  5. Radiation protection at new reactors

    Energy Technology Data Exchange (ETDEWEB)

    Brissaud, A. [EDF INDUSTRY, Basic Design Department, EDF-SEPTEN, VILLEURBANNE Cedex (France)


    The theoritical knowledge and the feedback of operating experience concerning radiations in reactors is now considerable. It is available to the designer in the form of predictive softwares and data bases. Thus, it is possible to include the radiation protection component throughout all the design process. In France, the existing reactors have not been designed with quantified radiation protection targets, although considerable efforts have been made to reduce sources of radiation illustrated by the decrease of the average dose rates (typically a factor 5 between the first 900 MWe and the last 1300 MWe units). The EDF ALARA PROJECT has demonstrated that good practises, radiation protection awareness, careful work organization had a strong impact on operation and maintenance work volume. A decrease of the average collective dose by a factor 2 has been achieved without noticeable modifications of the units. In the case of new nuclear facilities projects (reactor, intermediate storage facility,...), or special operations (such as steam generator replacement), quantified radiation protection targets are included in terms of collective and average individual doses within the frame of a general optimization scheme. The target values by themselves are less important than the application of an optimization process throughout the design. This is because the optimization process requires to address all the components of the dose, particularly the work volume for operation and maintenance. A careful study of this parameter contributes to the economy of the project (suppression of unecessary tasks, time-saving ergonomy of work sites). This optimization process is currently applied to the design of the EPR. General radiation protection provisions have been addressed during the basic design phase by applying general rules aiming at the reduction of sources and dose rates. The basic design optimization phase has mainly dealt with the possibility to access the containment at full

  6. The research reactors their contribution to the reactors physics; Les reacteurs de recherche leur apport sur la physique des reacteurs

    Energy Technology Data Exchange (ETDEWEB)

    Barral, J.C. [Electricite de France (EDF), 75 - Paris (France); Zaetta, A. [CEA/Cadarache, Direction des Reacteurs Nucleaires, DRN, 13 - Saint-Paul-lez-Durance (France); Johner, J. [CEA/Cadarache, Dept. de Recherches sur la Fusion Controlee (DRFC), 13 - Saint Paul lez Durance (France); Mathoniere, G. [CEA/Saclay, DEN, 91 - Gif sur Yvette (France)] [and others


    The 19 october 2000, the french society of nuclear energy organized a day on the research reactors. This associated report of the technical session, reactors physics, is presented in two parts. The first part deals with the annual meeting and groups general papers on the pressurized water reactors, the fast neutrons reactors and the fusion reactors industry. The second part presents more technical papers about the research programs, critical models, irradiation reactors (OSIRIS and Jules Horowitz) and computing tools. (A.L.B.)

  7. Riflessioni sulla formazione in servizio degli insegnanti nelle scuole italo-argentine della città e provincia di Córdoba / Considerations about the training of teachers in Italian-Argentine schools in the town and province of Córdoba

    Directory of Open Access Journals (Sweden)

    Luciana Zollo


    The bilingual and intercultural condition of Italian schools in Argentina represents a potential to the education of an active citizenship in today’s Latin American context. Italian literature, either as a way of expressing the social and historical aspects which strongly connect Argentine culture to the Italian one, or as a means towards literature education and the endorsement of the reading habit, can be proposed as a significant contribution to the validation of Italian intangible heritage. The role of Italian literature within the curricula is taken into consideration, as well as the educational proposals and projects and, particularly, the teachers’ training activities. The bilingual and bicultural curriculum of the schools in Córdoba City and Province, originated within communities strongly characterized by the history of Italian migrations in Argentina, constitutes the starting point for a reflection on didactics, the teachers’ profile and their entrusted tasks, the goals and methods of their inservice training. The complexity of the linguistic and socio-cultural identity of those who are protagonists in the experience of “making the Italian school” in Argentina offers multiple ideas with the purpose of arising both individual and social awareness of an Italian culture to be recognized, appreciated and reworked.

  8. PCCF flow analysis -- DR Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Calkin, J.F.


    This report contains an analysis of PCCF tube flow and Panellit pressure relations at DR reactor. Supply curves are presented at front header pressures from 480 to 600 psig using cold water and the standard 0.236 inch orifice with taper down stream and the pigtail valve (plug or ball) open. Demand curves are presented for slug column lengths of 200 inches to 400 inches using 1.44 inch O.D. solid poison pieces (either Al or Pb-Cd) and cold water with a rear header pressure of 50 psig. Figure 1 is a graph of Panellit pressure vs. flow with the above supply and demand curves and clearly shows the effect of front header pressure and charge length on flow.

  9. Coacervates as prebiotic chemical reactors (United States)

    Kolb, Vera M.; Swanson, Mercedes; Menger, Fredric M.


    Coacervates are colloidal systems that are comprised of two immiscible aqueous layers, the colloid-rich layer, so-called coacervate, and the colloid-poor layer, so-called equilibrium liquid. Although immiscible, the two phases are both water-rich. Coacervates are important for prebiotic chemistry, but also have various practical applications, notably as transport vehicles of personal care products and pharmaceuticals. Our objectives are to explore the potential of coacervates as prebiotic chemical reactors. Since the reaction medium in coacervates is water, this creates a challenge, since most organic reactants are not water-soluble. To overcome this challenge we are utilizing recent Green Chemistry examples of the organic reactions in water, such as the Passerini reaction. We have investigated this reaction in two coacervate systems, and report here our preliminary results.

  10. Replacement reactor to revolutionise magnets

    CERN Document Server

    Atkins, G


    Electric motors, hearing aids and magnetic resonance imaging are only some of the applications that will benefit from the first advances in magnets in a quarter of a century. Magnets achieve their characteristics when electrons align themselves to produce a unified magnetic field. Neutrons can probe these magnetic structures. The focus is not just on making more powerful magnets, but also identifying the characteristics that make magnets cheaper and easier for industry to manufacture. Staff from the ANSTO's Neutron Scattering Group have already performed a number of studies on the properties of magnets using using HIFAR, but the Replacement Research Reactor that will produce cold neutrons would allow scientists to investigate the atomic properties of materials with large molecules. A suite of equipment will enable studies at different temperatures, pressures and magnetic fields

  11. Dynamic analysis of process reactors

    Energy Technology Data Exchange (ETDEWEB)

    Shadle, L.J.; Lawson, L.O.; Noel, S.D.


    The approach and methodology of conducting a dynamic analysis is presented in this poster session in order to describe how this type of analysis can be used to evaluate the operation and control of process reactors. Dynamic analysis of the PyGas{trademark} gasification process is used to illustrate the utility of this approach. PyGas{trademark} is the gasifier being developed for the Gasification Product Improvement Facility (GPIF) by Jacobs-Siffine Engineering and Riley Stoker. In the first step of the analysis, process models are used to calculate the steady-state conditions and associated sensitivities for the process. For the PyGas{trademark} gasifier, the process models are non-linear mechanistic models of the jetting fluidized-bed pyrolyzer and the fixed-bed gasifier. These process sensitivities are key input, in the form of gain parameters or transfer functions, to the dynamic engineering models.

  12. Reactor operation environmental information document

    Energy Technology Data Exchange (ETDEWEB)

    Wike, L.D.; Specht, W.L.; Mackey, H.E.; Paller, M.H.; Wilde, E.W.; Dicks, A.S.


    The Savannah River Site (SRS) is a large United States Department of Energy installation on the upper Atlantic Coastal Plain of South Carolina. The SRS contains diverse habitats, flora, and fauna. Habitats include upland terrestrial areas, varied wetlands including Carolina Bays, the Savannah River swamp system, and impoundment related and riparian wetlands, and the aquatic habitats of several stream systems, two large cooling reservoirs, and the Savannah River. These diverse habitats support a large variety of plants and animals including many commercially or recreational valuable species and several rare, threatened or endangered species. This volume describes the major habitats and their biota found on the SRS, and discuss the impacts of continued operation of the K, L, and P production reactors.

  13. (Meeting on fusion reactor materials)

    Energy Technology Data Exchange (ETDEWEB)

    Jones, R.H. (Pacific Northwest Lab., Richland, WA (USA)); Klueh, R.L.; Rowcliffe, A.F.; Wiffen, F.W. (Oak Ridge National Lab., TN (USA)); Loomis, B.A. (Argonne National Lab., IL (USA))


    During his visit to the KfK, Karlsruhe, F. W. Wiffen attended the IEA 12th Working Group Meeting on Fusion Reactor Materials. Plans were made for a low-activation materials workshop at Culham, UK, for April 1991, a data base workshop in Europe for June 1991, and a molecular dynamics workshop in the United States in 1991. At the 11th IEA Executive Committee on Fusion Materials, discussions centered on the recent FPAC and Colombo panel review in the United States and EC, respectively. The Committee also reviewed recent progress toward a neutron source in the United States (CWDD) and in Japan (ESNIT). A meeting with D. R. Harries (consultant to J. Darvas) yielded a useful overview of the EC technology program for fusion. Of particular interest to the US program is a strong effort on a conventional ferritic/martensitic steel for fist wall/blanket operation beyond NET/ITER.

  14. Flexible Conversion Ratio Fast Reactor Systems Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Neil Todreas; Pavel Hejzlar


    Conceptual designs of lead-cooled and liquid salt-cooled fast flexible conversion ratio reactors were developed. Both concepts have cores reated at 2400 MWt placed in a large-pool-type vessel with dual-free level, which also contains four intermediate heat exchanges coupling a primary coolant to a compact and efficient supercritical CO2 Brayton cycle power conversion system. Decay heat is removed passively using an enhanced Reactor Vessel Auxiliary Cooling System and a Passive Secondary Auxiliary Cooling System. The most important findings were that (1) it is feasible to design the lead-cooled and salt-cooled reactor with the flexible conversion ratio (CR) in the range of CR=0 and CR=1 n a manner that achieves inherent reactor shutdown in unprotected accidents, (2) the salt-cooled reactor requires Lithium thermal Expansion Modules to overcme the inherent salt coolant's large positive coolant temperature reactivity coefficient, (3) the preferable salt for fast spectrum high power density cores is NaCl-Kcl-MgCl2 as opposed to fluoride salts due to its better themal-hydraulic and neutronic characteristics, and (4) both reactor, but attain power density 3 times smaller than that of the sodium-cooled reactor.

  15. The Swedish Zero Power Reactor R0

    Energy Technology Data Exchange (ETDEWEB)

    Landergaard, Olof; Cavallin, Kaj; Jonsson, Georg


    The reactor R0 is a critical facility built for heavy water and natural uranium or fuel of low enrichment,, The first criticality was achieved September 25, 1959. During a first period of more than two years the R0 will be operated as a bare reactor in order to simplify interpretation of results. The reactor tank is 3. 2 m high and 2. 25 m in diameter. The fuel suspension system is quite flexible in order to facilitate fuel exchange and lattice variations. The temperature of the water can be varied between about 10 and 90 C by means of a heater and a cooler placed in the external circulating system. The instrumentation of the reactor has to meet the safety requirements not only during operation but also during rearrangements of the core in the shut-down state. Therefore, the shut-down state is always defined by a certain low 'safe' moderator level in the reactor tank. A number of safety rods are normally kept above the moderator ready for action. For manual or automatic control of the reactor power a specially designed piston pump is needed, by which the moderator level is varied. The pump speed is controlled from the reactor power error by means of a Ward-Leonard system. Moderator level measurement is made by means of a water gauge with an accuracy of {+-} 0. 1 mm.

  16. Experience of the Argentine Radioprotection Society in training in radiological protection; Experiencia de la Sociedad Argentina de radioproteccion en capacitacion en proteccion radiologica

    Energy Technology Data Exchange (ETDEWEB)

    Bomben, A.M. [Sociedad Argentina de Radioproteccion (SAR), Av. del Libertador 8250 of. 122, (1429), Buenos Aires (Argentina)]. e-mail:


    From its creation in 1967, the Argentine Radioprotection Society (SAR) has as basic purpose promoting all the aspects related with the radiological protection and the nuclear safety. Due to the great increment in the use of radioactive sources in diverse areas, soon it was evident for the SAR the importance and necessity to promote the knowledge of the radioprotection approaches between the users of radioactive sources and ionizing radiations in all its application fields, be these industrial, academic or doctors. From the year 2000, the SAR comes organizing in regular and periodical form basic and specialized courses about radiological safety of radioactive sources for industrial use and profile of oil wells, among others. In this work, the characteristics of the different dictated courses are described whose programs have been developed keeping in mind the requirements of the competent authorities of Argentina. Also, statistical information on the dictated courses and its participants is presented. The number of dictated courses was incremented from 6 (year 2000) up to 16 (year 2005), being also increased significantly the number of participants for course. The dictated courses are theoretical-practical, with a duration average of 20 hs. The educational body is constituted by specialists in the different topics with recognized experience. Its given to the participants notes and support material, as well as copies of the material presented to develop the course. When concluding the courses, its deliver to the participants certifies of attendance and/or approval, as it corresponds. In their headquarters the SAR has didactic facilities and specific equipment for the dictation of the courses. Also accounts with the easiness of dictating those courses outside of their headquarters. This is particularly advantageous for companies or organizations that are seated in points far from the main cities and they should qualify in radiological safety to the personnel but, by

  17. The severe zonda wind event of 11 July 2006 east of the Andes Cordillera (Argentine): a case study using the BRAMS model (United States)

    Norte, Federico Augusto; Ulke, Ana Graciela; Simonelli, Silvia Carmen; Viale, Maximiliano


    The zonda is a wind that exhibits the so-called foehn effect: a warm, dry, strong wind related to adiabatic compression upon descending in the lee of the Andes. This phenomenon occurs mostly in winter and spring over the entire length of the extratropical Andes. It is frequently detected near the cities of Mendoza and San Juan, the most important urban regions of western Argentina. The aim of this work is to understand why a zonda wind event, occurring on 11 July 2006, reached and maintained the higher category Z4 during several hours. A secondary aim is to evaluate the ability of a Brazilian regional atmospheric modeling system (BRAMS) model to represent the features of this extreme episode and to explore if it can be used to predict a zonda event. The difference found with respect to other severe zonda wind episodes analyzed was that the wind registered the highest category (Z4) with extreme gusts during a long period. This condition was registered in particular on southern plain areas of San Juan province. The phenomenon had a great impact on the community, with residences and buildings being affected or destroyed, trees being felled, power supply and communications being shutdown, and several rural and urban fires being reported. The event was characterized through surface and upper-level information and model results. The synoptic surface and upper-air conditions were those typically associated with a severe zonda wind occurrence: a surface cold front approaching the region, driven by a 500 hPa trough, a strong upper-air jet stream, and a deep low-pressure surface system at higher latitudes over the Atlantic Ocean. The North West Argentine Low in central west Argentina during the following hours could be observed centered approximately at 31°S 66°W. in a few lower latitude than the location observed by National Center of Environmental Prediction (NCEP) reanalysis. On the other hand, it is the authors’ impression that the BRAMS model achieved an acceptable

  18. Encuadrando el delito: pánico moral en los periódicos Argentinos Framing crime: moral panic in Argentine newspapers

    Directory of Open Access Journals (Sweden)

    Natalia ARUGUETE


    Full Text Available El asalto a Carolina Píparo a la salida de un banco en la provincia de Buenos Aires, Argentina, estremeció a la opinión pública por tratarse de una víctima embarazada que, a raíz de un disparo recibido en el ataque, debió someterse a una cesárea después de la cual su hijo sobrevivió sólo una semana. Este trabajo analiza el tipo de tratamiento que recibió el llamado «caso Píparo» a través de un análisis de contenido exploratorio e inductivo de la cobertura que los diarios Clarín y La Nación dieron al tema. El objetivo es elaborar un libro de códigos que pueda ser validado en estudios de casos similares mediante el análisis de contenido de la prensa gráfica. Se busca aplicar la teoría del framing para, desde la detección de los encuadres noticiosos empleados, discutir si éstos son compatibles con el concepto de pánico moral planteado por Stanley Cohen.Carolina Píparo was shot a few minutes after withdrawing cash from a bank branch. This case outraged the public opinion because she was eight months pregnant at the moment of the assault. She had to undergo a caesarean section and her baby only survived one week. Through an exploratory and inductive research we will analyze how the Argentine newspapers presented the case. We aim at elaborating a content analysis code book that can be validated in future similar researches on the subject. We apply the Framing theory in order to detect the frames used in the news coverage and to observe if they are compatible with the idea of «moral panic» proposed by Stanley Cohen.

  19. Dictature, témoignage, histoire : paroles de victimes et de bourreaux dans les littératures argentine et chilienne (1983-2002

    Directory of Open Access Journals (Sweden)

    José García-Romeu


    Full Text Available Les dictatures militaires qui gouvernèrent le Chili et l’Argentine dans les années soixante-dix et quatre-vingt eurent un impact considérable sur les écrivains. Nous étudierons comment certains textes littéraires abordent la question à travers une reconstruction de la mémoire et de l’histoire, nationale ou familiale, en recourant au témoignage des victimes ou des bourreaux. Parfois l’auteur médiatise son expérience personnelle, d’autres fois il fabrique une fiction complexe et ambiguë. Cette étude nous permettra de distinguer à ce propos deux générations, la première soucieuse de résoudre les traumatismes propres (Daniel Moyano, Libro de navíos y borrascas, 1983 ; Juan Gelman, Interrupciones 2, 1988, la seconde engagée dans un réquisitoire envers les responsables de la répression (Roberto Bolaño, Nocturno de Chile, 2000 ; Martín Kohan, Dos veces junio, 2002.Las dictaduras militares que gobernaron en Chile y en Argentina durante los años setenta y ochenta tuvieron un impacto importante en los escritores. Estudiaremos cómo algunos textos literarios contemplan el problema mediante una reconstrucción de la memoria y de la historia, nacional o familiar, recurriendo al testimonio de las víctimas y de los verdugos. A veces, el autor representa su experiencia personal, otras fabrica una ficción compleja y ambigua. Este estudio nos ayudará a distinguir dos generaciones, la primera preocupada en resolver los traumas propios (Daniel Moyano, Libro de navíos y borrascas, 1983 ; Juan Gelman, Interrupciones 2, 1988, la segunda comprometida en acusar a los responsables de la represión (Roberto Bolaño, Nocturno de Chile, 2000 ; Martín Kohan, Dos veces junio, 2002.

  20. Pratiques alimentaires et (reconstruction identitaire chez des migrants boliviens de retour d’Argentine Foodways and identity (reconstruction among Bolivian migrants returning from Argentina

    Directory of Open Access Journals (Sweden)

    Charles-Édouard de Suremain


    Full Text Available L’étude anthropologique des pratiques alimentaires de migrants boliviens de retour ayant longuement séjourné en Argentine permet d’aborder la problématique de la migration et de l’identité : la construction sociale, réelle et imaginaire, de la migration ne passe-t-elle pas aussi par l’alimentation ? Ce que l’on mange ici et là-bas éclaire, en creux, le succès ou l’échec donné à la migration par les migrants et aide à comprendre plus finement les significations locales données à la pauvreté et à la richesse, au bien-être et au mal-être. L’observation et les « récits de vie alimentaires » menés dans une perspective intergénérationnelle – sur l’importance de la consommation attribuée au pain, à la viande et au soda– conduisent finalement à s’interroger sur la situation sociale et symbolique des migrants de retour dans leur société d’origine comme dans la société d’accueil. Au-delà, l’étude montre que les pratiques et les représentations alimentaires reflètent et structurent à la fois des relations sociales, des relations de sexe et des rapports au corps, et qu’elles permettent d’induire des processus de construction d’identités complexes.The anthropological study of Bolivian returnees’ food practices, who have spent a long time in Argentina, leads us to deal with the problematic of migration and identity: as a matter of fact, the social construction of migration, either real or imaginary, is also based on alimentation. What is eaten here and there enlightens, in a way, the success or failure of their migration, as perceived from the migrants’ point of view; it helps to deeply understand the local significations given to poverty and wealth, to well-being and discontent. Observation and « intergenerational food life stories », conducted on the importance of consumption of bread, meat and sodas, finally lead to question the social and symbolic situation of returnees

  1. Entre el "deber" y el "derecho": patrimonio arqueológico y obligaciones sociales en Patagonia Argentina Among "duty" and "rights": Archaeological heritage and social obligations in Argentine

    Directory of Open Access Journals (Sweden)

    Carolina Crespo


    actualized around this heritage, the change of meanings of these artefacts that such relationships motivate and the effects they produce on the management of the archaeological heritage. An analysis of the exchange of services and of the mutual obligations that arise serves as an example of the new meanings acquired by archaeological goods - especially rock art in Argentine Patagonia - in recent years, as well as the complexities of its management.

  2. Facility for a Low Power Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Chalker, R. G.


    Preliminary investigation indicates that a reactor facility with ample research provisions for use by University or other interested groups, featuring safety in design, can be economically constructed in the Los Angeles area. The complete installation, including an underground gas-tight reactor building, with associated storage and experiment assembly building, administration offices, two general laboratory buildings, hot latoratory and lodge, can be constructed for approxinately $1,500,000. This does not include the cost of the reactor itself or of its auxiliary equipment,

  3. Pyrometric fuel particle measurements in pressurised reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hernberg, R.; Joutsenoja, T. [Tampere Univ. of Technology (Finland)


    A fiberoptic two-colour pyrometric technique for fuel particle temperature and size measurement is modified and applied to three pressurized reactors of different type in Finland, Germany and France. A modification of the pyrometric method for simultaneous in situ measurement of the temperature and size of individual pulverized coal particles at the pressurized entrained flow reactor in Jyvaeskylae was developed and several series of measurements were made. In Orleans a fiberoptic pyrometric device was installed to a pressurised thermogravimetric reactor and the two-colour temperatures of fuel samples were measured. Some results of these measurements are presented. The project belongs to EU`s Joule 2 extension research programme. (author)

  4. Oxidation performance of graphite material in reactors

    Institute of Scientific and Technical Information of China (English)

    Xiaowei LUO; Xinli YU; Suyuan YU


    Graphite is used as a structural material and moderator for high temperature gas-cooled reactors (HTGR). When a reactor is in operation, graphite oxida-tion influences the safety and operation of the reactor because of the impurities in the coolant and/or the acci-dent conditions, such as water ingress and air ingress. In this paper, the graphite oxidation process is introduced, factors influencing graphite oxidation are analyzed and discussed, and some new directions for further study are pointed out.

  5. Sistemas de salvaguardia en reactores EPR



    En este documento se describe brevemente el funcionamiento de los diversos sistemas de una planta nuclear operada con un reactor de tipo PWR. Más concretamente, el proyecto se centra en una descripción exhaustiva de los sistemas de salvaguardia y seguridad que regulan el funcionamiento de un reactor de tipo EPR, así como la central nuclear que contiene a dicho reactor. El proceso ha consistido en clasificar y resumir los distintos sistemas que operan en dicha planta, estudiando sus caracterís...

  6. Packed fluidized bed blanket for fusion reactor (United States)

    Chi, John W. H.


    A packed fluidized bed blanket for a fusion reactor providing for efficient radiation absorption for energy recovery, efficient neutron absorption for nuclear transformations, ease of blanket removal, processing and replacement, and on-line fueling/refueling. The blanket of the reactor contains a bed of stationary particles during reactor operation, cooled by a radial flow of coolant. During fueling/refueling, an axial flow is introduced into the bed in stages at various axial locations to fluidize the bed. When desired, the fluidization flow can be used to remove particles from the blanket.

  7. Monitoring and control of anaerobic reactors

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær;


    measurements are reviewed in detail. In the sequel, possible manipulated variables, such as the hydraulic retention time, the organic loading rate, the sludge retention time, temperature, pH and alkalinity are evaluated with respect to the two main reactor types: high-rate and low-rate. Finally, the different......The current status in monitoring and control of anaerobic reactors is reviewed. The influence of reactor design and waste composition on the possible monitoring and control schemes is examined. After defining the overall control structure, and possible control objectives, the possible process...

  8. Transients in reactors for power systems compensation (United States)

    Abdul Hamid, Haziah

    This thesis describes new models and investigations into switching transient phenomena related to the shunt reactors and the Mechanically Switched Capacitor with Damping Network (MSCDN) operations used for reactive power control in the transmission system. Shunt reactors and MSCDN are similar in that they have reactors. A shunt reactor is connected parallel to the compensated lines to absorb the leading current, whereas the MSCDN is a version of a capacitor bank designed as a C-type filter for use in the harmonic-rich environment. In this work, models have been developed and transient overvoltages due to shunt reactor deenergisation were estimated analytically using MathCad, a mathematical program. Computer simulations used the ATP/EMTP program to reproduce both single-phase and three-phase shunt reactor switching at 275 kV operational substations. The effect of the reactor switching on the circuit breaker grading capacitor was also examined by considering various switching conditions.. The main original achievement of this thesis is the clarification of failure mechanisms occurring in the air-core filter reactor due to MSCDN switching operations. The simulation of the MSCDN energisation was conducted using the ATP/EMTP program in the presence of surge arresters. The outcome of this simulation shows that extremely fast transients were established across the air-core filter reactor. This identified transient event has led to the development of a detailed air-core reactor model, which accounts for the inter-turn RLC parameters as well as the stray capacitances-to-ground. These parameters are incorporated into the transient simulation circuit, from which the current and voltage distribution across the winding were derived using electric field and equivalent circuit modelling. Analysis of the results has revealed that there are substantial dielectric stresses imposed on the winding insulation that can be attributed to a combination of three factors. (i) First, the

  9. Assessing Pretreatment Reactor Scaling Through Empirical Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lischeske, James J.; Crawford, Nathan C.; Kuhn, Erik; Nagle, Nicholas J.; Schell, Daniel J.; Tucker, Melvin P.; McMillan, James D.; Wolfrum, Edward J.


    Pretreatment is a critical step in the biochemical conversion of lignocellulosic biomass to fuels and chemicals. Due to the complexity of the physicochemical transformations involved, predictively scaling up technology from bench- to pilot-scale is difficult. This study examines how pretreatment effectiveness under nominally similar reaction conditions is influenced by pretreatment reactor design and scale using four different pretreatment reaction systems ranging from a 3 g batch reactor to a 10 dry-ton/d continuous reactor. The reactor systems examined were an Automated Solvent Extractor (ASE), Steam Explosion Reactor (SER), ZipperClave(R) reactor (ZCR), and Large Continuous Horizontal-Screw Reactor (LHR). To our knowledge, this is the first such study performed on pretreatment reactors across a range of reaction conditions (time and temperature) and at different reactor scales. The comparative pretreatment performance results obtained for each reactor system were used to develop response surface models for total xylose yield after pretreatment and total sugar yield after pretreatment followed by enzymatic hydrolysis. Near- and very-near-optimal regions were defined as the set of conditions that the model identified as producing yields within one and two standard deviations of the optimum yield. Optimal conditions identified in the smallest-scale system (the ASE) were within the near-optimal region of the largest scale reactor system evaluated. A reaction severity factor modeling approach was shown to inadequately describe the optimal conditions in the ASE, incorrectly identifying a large set of sub-optimal conditions (as defined by the RSM) as optimal. The maximum total sugar yields for the ASE and LHR were 95%, while 89% was the optimum observed in the ZipperClave. The optimum condition identified using the automated and less costly to operate ASE system was within the very-near-optimal space for the total xylose yield of both the ZCR and the LHR, and was

  10. Passive compact molten salt reactor (PCMSR), modular thermal breeder reactor with totally passive safety system

    Energy Technology Data Exchange (ETDEWEB)

    Harto, Andang Widi [Engineering Physics Department, Faculty of Engineering, Gadjah Mada University (Indonesia)


    Design Study Passive Compact Molten Salt Reactor (PCMSR) with totally passive safety system has been performed. The term of Compact in the PCMSR name means that the reactor system is designed to have relatively small volume per unit power output by using modular and integral concept. In term of modular, the reactor system consists of three modules, i.e. reactor module, turbine module and fuel management module. The reactor module is an integral design that consists of reactor, primary and intermediate heat exchangers and passive post shutdown cooling system. The turbine module is an integral design of a multi heating, multi cooling, regenerative gas turbine. The fuel management module consists of all equipments related to fuel preparation, fuel reprocessing and radioactive handling. The preliminary calculations show that the PCMSR has negative temperature and void reactivity coefficient, passive shutdown characteristic related to fuel pump failure and possibility of using natural circulation for post shutdown cooling system.

  11. Advanced research reactor fuel development

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang Kyu; Pak, H. D.; Kim, K. H. [and others


    The fabrication technology of the U{sub 3}Si fuel dispersed in aluminum for the localization of HANARO driver fuel has been launches. The increase of production yield of LEU metal, the establishment of measurement method of homogeneity, and electron beam welding process were performed. Irradiation test under normal operation condition, had been carried out and any clues of the fuel assembly breakdown was not detected. The 2nd test fuel assembly has been irradiated at HANARO reactor since 17th June 1999. The quality assurance system has been re-established and the eddy current test technique has been developed. The irradiation test for U{sub 3}Si{sub 2} dispersed fuels at HANARO reactor has been carried out in order to compare the in-pile performance of between the two types of U{sub 3}Si{sub 2} fuels, prepared by both the atomization and comminution processes. KAERI has also conducted all safety-related works such as the design and the fabrication of irradiation rig, the analysis of irradiation behavior, thermal hydraulic characteristics, stress analysis for irradiation rig, and thermal analysis fuel plate, for the mini-plate prepared by international research cooperation being irradiated safely at HANARO. Pressure drop test, vibration test and endurance test were performed. The characterization on powders of U-(5.4 {approx} 10 wt%) Mo alloy depending on Mo content prepared by rotating disk centrifugal atomization process was carried out in order to investigate the phase stability of the atomized U-Mo alloy system. The {gamma}-U phase stability and the thermal compatibility of atomized U-16at.%Mo and U-14at.%Mo-2at.%X(: Ru, Os) dispersion fuel meats at an elevated temperature have been investigated. The volume increases of U-Mo compatibility specimens were almost the same as or smaller than those of U{sub 3}Si{sub 2}. However the atomized alloy fuel exhibited a better irradiation performance than the comminuted alloy. The RERTR-3 irradiation test of nano

  12. Hydrodynamics of multi-phase packed bed micro-reactors

    NARCIS (Netherlands)

    Márquez Luzardo, N.M.


    Why to use packed bed micro-reactors for catalyst testing? Miniaturized packed bed reactors have a large surface-to-volume ratio at the reactor and particle level that favors the heat- and mass-transfer processes at all scales (intra-particle, inter-phase and inter-particle or reactor level). If the

  13. Progress of China Experimental Fast Reactor in 2011

    Institute of Scientific and Technical Information of China (English)


    1 Background Fast reactor is the reactor which realized the chain fission with fast neutron.As an optional type of generation Ⅳ reactor,fast reactor has three characters:1) It can change 238U to 239Pu and raise the uranium resource utilization

  14. Uncertainties in the Anti-neutrino Production at Nuclear Reactors


    Djurcic, Z.(Argonne National Laboratory, Argonne, Illinois, 60439, U.S.A.); Detwiler, J. A.; Piepke, A.; Foster Jr., V. R.; Miller, L.; Gratta, G.


    Anti-neutrino emission rates from nuclear reactors are determined from thermal power measurements and fission rate calculations. The uncertainties in these quantities for commercial power plants and their impact on the calculated interaction rates in electron anti-neutrino detectors is examined. We discuss reactor-to-reactor correlations between the leading uncertainties and their relevance to reactor anti-neutrino experiments.

  15. Ex-vessel Steam Explosion Analysis for Pressurized Water Reactor and Boiling Water Reactor


    Matjaž Leskovar; Mitja Uršič


    A steam explosion may occur during a severe accident, when the molten core comes into contact with water. The pressurized water reactor and boiling water reactor ex-vessel steam explosion study, which was carried out with the multicomponent three-dimensional Eulerian fuel–coolant interaction code under the conditions of the Organisation for Economic Co-operation and Development (OECD) Steam Explosion Resolution for Nuclear Applications project reactor exercise, is presented and discussed. In ...

  16. Optimization of a sequence of reactors

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui


    Concerns the optimal production of sulphuric acid in a sequence of reactors. Using a suitable approximation to the objective function, this problem can easily be solved using the maximum principle. A numerical example documents the applicability of the suggested approach...

  17. The Bifurcation Behavior of CO Coupling Reactor

    Institute of Scientific and Technical Information of China (English)

    徐艳; 马新宾; 许根慧


    The bifurcation behavior of the CO coupling reactor was examined based on the one-dimensional pseudohomogeneous axial dispersion dynamic model. The method of finite difference was used for solving the boundary value problem; the continuation technique and the direct method were applied to determine the bifurcation diagram.The effects of dimensionless adiabatic temperature rise, Damkoehler number, activation energy, heat transfer coefficient and feed ratio on the bifurcation behavior were investigated. It was shown that there existed static bifurcation and the oscillations did not occur in the reactor. The result also revealed that the reactor exhibited at most 1-3-1 multiplilicity patterns within the range of practical possible parameters and the measures, such as weakening the axial dispersion of reactor, enhancing heat transfer, decreasing the concentration of ethyl nitrite, were efficient for avoiding the possible risk of multiple steady states.

  18. Heat pipe reactors for space power applications (United States)

    Koenig, D. R.; Ranken, W. A.; Salmi, E. W.


    A family of heat pipe reactors design concepts has been developed to provide heat to a variety of electrical conversion systems. Three power plants are described that span the power range 1-500 kWe and operate in the temperature range 1200-1700 K. The reactors are fast, compact, heat-pipe cooled, high-temperature nuclear reactors fueled with fully enriched refractory fuels, UC-ZrC or UO2. Each fuel element is cooled by an axially located molybdenum heat pipe containing either sodium or lithium vapor. Virtues of the reactor designs are the avoidance of single-point failure mechanisms, the relatively high operating temperature, and the expected long lifetimes of the fuel element components.

  19. Reactor Antineutrinos: From Confusion to Clarity (United States)

    Dwyer, Dan


    Antineutrinos emitted by nuclear reactors have been a powerful tool for particle physics, demonstrating the existence of these weakly-interacting particles as well as their flavor oscillation. Despite these successes, our understanding of the total flux and energy spectra of reactor antineutrinos has been fraught with problems. I will give a brief overview of the unexpected developments in this field, and discuss upcoming measurements of antineutrinos, beta decays, and nuclear fission which are relevant to these questions. These measurements are expected to clarify many currently murky issues, including the hypothetical oscillation of reactor antineutrinos to sterile states. The results should also provide a unique perspective into the nuclear physics of fission reactors. DOE OHEP DE-AC02-05CH11231.

  20. Chemical reactor modeling multiphase reactive flows

    CERN Document Server

    Jakobsen, Hugo A


    Chemical Reactor Modeling closes the gap between Chemical Reaction Engineering and Fluid Mechanics.  The second edition consists of two volumes: Volume 1: Fundamentals. Volume 2: Chemical Engineering Applications In volume 1 most of the fundamental theory is presented. A few numerical model simulation application examples are given to elucidate the link between theory and applications. In volume 2 the chemical reactor equipment to be modeled are described. Several engineering models are introduced and discussed. A survey of the frequently used numerical methods, algorithms and schemes is provided. A few practical engineering applications of the modeling tools are presented and discussed. The working principles of several experimental techniques employed in order to get data for model validation are outlined. The monograph is based on lectures regularly taught in the fourth and fifth years graduate courses in transport phenomena and chemical reactor modeling, and in a post graduate course in modern reactor m...

  1. µ-reactors for Heterogeneous Catalysis

    DEFF Research Database (Denmark)

    Jensen, Robert

    catalyst surface area by reacting off an adsorbed layer of oxygen with CO. This procedure can be performed at temperatures low enough that sintering of Pt nanoparticles is not an issue. Some results from the reactors are presented. In particular an unexpected oscillation phenomenon of CO-oxidation on Pt...... nanoparticles are presented in detail. The sensitivity of the reactors are currently being investigated with CO oxidation on Pt thin films as a test reaction, and the results so far are presented. We have at this point shown that we are able to reach full conversion with a catalyst area of 38 µm2 with a turn......This thesis is the summary of my work on the µ-reactor platform. The concept of µ-reactors is presented and some of the experimental challenges are outlined. The various experimental issues regarding the platform are discussed and the actual implementation of three generations of the setup...

  2. Corrosion Minimization for Research Reactor Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Eric Shaber; Gerard Hofman


    Existing university research reactors are being converted to use low-enriched uranium fue to eliminate the use of highly-enriched uranium. These conversions require increases in fuel loading that will result in the use of elements with more fuel plates, resulting in a net decrease in the water annulus between fuel plates. The proposed decrease in the water annulus raises questions about the requirements and stability of the surface hydroxide on the aluminum fuel cladding and the potential for runaway corrosion resulting in fuel over-temperature incidents. The Nuclear Regulatory Commission (NRC), as regulator for these university reactors, must ensure that proposed fuel modifications will not result in any increased risk or hazard to the reactor operators or the public. This document reviews the characteristics and behavior of aluminum hydroxides, analyzes the drivers for fuel plate corrosion, reviews relevant historical incidents, and provides recommendations on fuel design, surface treatment, and reactor operational practices to avoid corrosion issues.

  3. Interactions of Pellet with Reactor Relevant Plasma

    Institute of Scientific and Technical Information of China (English)

    PENGLilin; DENGBaiquan; YANJiancheng


    Extended algorithm has been developed for ablation rate calculations of Li, Be, B impurity pellets and five combinations of solid isotopic hydrogenic H2, HD, D2, DT, T2 pellets. Numerical calculations have been performed for reactor relevant plasma.

  4. Autonomous Control of Space Nuclear Reactors Project (United States)

    National Aeronautics and Space Administration — Nuclear reactors to support future lunar and Mars robotic and manned missions impose new and innovative technological requirements for their control and protection...

  5. Advanced Test Reactor National Scientific User Facility

    Energy Technology Data Exchange (ETDEWEB)

    Frances M. Marshall; Jeff Benson; Mary Catherine Thelen


    The Advanced Test Reactor (ATR), at the Idaho National Laboratory (INL), is a large test reactor for providing the capability for studying the effects of intense neutron and gamma radiation on reactor materials and fuels. The ATR is a pressurized, light-water, high flux test reactor with a maximum operating power of 250 MWth. The INL also has several hot cells and other laboratories in which irradiated material can be examined to study material irradiation effects. In 2007 the US Department of Energy (DOE) designated the ATR as a National Scientific User Facility (NSUF) to facilitate greater access to the ATR and the associated INL laboratories for material testing research by a broader user community. This paper highlights the ATR NSUF research program and the associated educational initiatives.


    The Spouted Bed Reactor (SBR) technology utilizes the unique attributes of the "spouting " fluidization regime, which can provide heat transfer rates comparable to traditional fluid beds, while providing robust circulation of highly heterogeneous solids, concurrent with very agg...

  7. Molten salt reactors - safety options galore

    Energy Technology Data Exchange (ETDEWEB)

    Gat, U. [Oak Ridge National Lab., TN (United States); Dodds, H.L. [Univ. of Tennessee, Knoxville, TN (United States)


    Safety features and attributes of molten salt reactors (MSR) are described. The unique features of fluid fuel reactors of on-line continuous processing and the ability for so-called external cooling result in simple and safe designs with low excess reactivity, low fission product inventory, and small source term. These, in turn, make a criticality accident unlikely and reduce the severity of a loss of coolant to where they are no longer severe accidents. A melt down is not an accident for a reactor that uses molten fuel. The molten salts are stable, non-reactive and efficient heat transfer media that operate at high temperatures at low pressures and are highly compatible with selected structural materials. All these features reduce the accident plethora. Freeze valves can be used for added safety. An ultimate safe reactor (U.S.R) is described with safety features that are passive, inherent and non-tamperable (PINT).

  8. Steady State Analysis of Small Molten Salt Reactor : Effect of Fuel Salt Flow on Reactor Characteristics


    Yamamoto, Takahisa; MITACHI, Koshi; Suzuki, Takashi


    The Molten Salt Reactor (MSR) is a thermal neutron reactor with graphite moderation and operates on the thorium-uranium fuel cycle. The feature of the MSR is that fuel salt flows inside the reactor during the nuclear fission reaction. In the previous study, the authors developed numerical model with which to simulate the effects of fuel salt flow on the reactor characteristics. In this study, we apply the model to the steady-state analysis of a small MSR system and estimate the effects of fue...

  9. Development of technology for next generation reactor - Development of next generation reactor in Korea -

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Kyun; Chang, Moon Heuy; Hwang, Yung Dong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)] [and others


    The project, development of next generation reactor, aims overall related technology development and obtainment of related license in 2001. The development direction is to determine the reactor type and to build up the design concept in 1994. For development trend analysis of foreign next generation reactor, level-1 PSA, fuel cycle analysis and computer code development are performed on System 80+ and AP 600. Especially for design characteristics analysis and volume upgrade of AP 600, nuclear fuel and reactor core design analysis, coolant circuit design analysis, mechanical structure design analysis and safety analysis etc. are performed. (Author).

  10. A fast and flexible reactor physics model for simulating neutron spectra and depletion in fast reactors (United States)

    Recktenwald, Geoff; Deinert, Mark


    Determining the time dependent concentration of isotopes within a nuclear reactor core is central to the analysis of nuclear fuel cycles. We present a fast, flexible tool for determining the time dependent neutron spectrum within fast reactors. The code (VBUDS: visualization, burnup, depletion and spectra) uses a two region, multigroup collision probability model to simulate the energy dependent neutron flux and tracks the buildup and burnout of 24 actinides, as well as fission products. While originally developed for LWR simulations, the model is shown to produce fast reactor spectra that show high degree of fidelity to available fast reactor benchmarks.

  11. Developments and Tendencies in Fission Reactor Concepts (United States)

    Adamov, E. O.; Fuji-Ie, Y.

    This chapter describes, in two parts, new-generation nuclear energy systems that are required to be in harmony with nature and to make full use of nuclear resources. The issues of transmutation and containment of radioactive waste will also be addressed. After a short introduction to the first part, Sect. 58.1.2 will detail the requirements these systems must satisfy on the basic premise of peaceful use of nuclear energy. The expected designs themselves are described in Sect. 58.1.3. The subsequent sections discuss various types of advanced reactor systems. Section 58.1.4 deals with the light water reactor (LWR) whose performance is still expected to improve, which would extend its application in the future. The supercritical-water-cooled reactor (SCWR) will also be shortly discussed. Section 58.1.5 is mainly on the high temperature gas-cooled reactor (HTGR), which offers efficient and multipurpose use of nuclear energy. The gas-cooled fast reactor (GFR) is also included. Section 58.1.6 focuses on the sodium-cooled fast reactor (SFR) as a promising concept for advanced nuclear reactors, which may help both to achieve expansion of energy sources and environmental protection thus contributing to the sustainable development of mankind. The molten-salt reactor (MSR) is shortly described in Sect. 58.1.7. The second part of the chapter deals with reactor systems of a new generation, which are now found at the research and development (R&D) stage and in the medium term of 20-30 years can shape up as reliable, economically efficient, and environmentally friendly energy sources. They are viewed as technologies of cardinal importance, capable of resolving the problems of fuel resources, minimizing the quantities of generated radioactive waste and the environmental impacts, and strengthening the regime of nonproliferation of the materials suitable for nuclear weapons production. Particular attention has been given to naturally safe fast reactors with a closed fuel cycle (CFC

  12. A comparison of radioactive waste from first generation fusion reactors and fast fission reactors with actinide recycling

    Energy Technology Data Exchange (ETDEWEB)

    Koch, M.; Kazimi, M.S.


    Limitations of the fission fuel resources will presumably mandate the replacement of thermal fission reactors by fast fission reactors that operate on a self-sufficient closed fuel cycle. This replacement might take place within the next one hundred years, so the direct competitors of fusion reactors will be fission reactors of the latter rather than the former type. Also, fast fission reactors, in contrast to thermal fission reactors, have the potential for transmuting long-lived actinides into short-lived fission products. The associated reduction of the long-term activation of radioactive waste due to actinides makes the comparison of radioactive waste from fast fission reactors to that from fusion reactors more rewarding than the comparison of radioactive waste from thermal fission reactors to that from fusion reactors. Radioactive waste from an experimental and a commercial fast fission reactor and an experimental and a commercial fusion reactor has been characterized. The fast fission reactors chosen for this study were the Experimental Breeder Reactor 2 and the Integral Fast Reactor. The fusion reactors chosen for this study were the International Thermonuclear Experimental Reactor and a Reduced Activation Ferrite Helium Tokamak. The comparison of radioactive waste parameters shows that radioactive waste from the experimental fast fission reactor may be less hazardous than that from the experimental fusion reactor. Inclusion of the actinides would reverse this conclusion only in the long-term. Radioactive waste from the commercial fusion reactor may always be less hazardous than that from the commercial fast fission reactor, irrespective of the inclusion or exclusion of the actinides. The fusion waste would even be far less hazardous, if advanced structural materials, like silicon carbide or vanadium alloy, were employed.

  13. Ensayo preclínico de la vacuna candid #1 producida en Argentina contra la Fiebre Hemorrágica Argentina Preclinical assay of Candid #1 vaccine against Argentine Hemorrhagic Fever made in Argentina

    Directory of Open Access Journals (Sweden)

    Ana M. Ambrosio


    Full Text Available Se comparó en cobayos la seguridad, inmunogenicidad y eficacia protectora de un lote de vacuna Candid #1(C#1 fabricada en Estados Unidos de América (EE.UU. y distintos lotes de la misma vacuna fabricados en Argentina (Arg. El lote TSI 5-1-92 (EE.UU. y los lotes Exp Nº 3, 7A y 8A (Arg fueron inoculados (0.5 ml, IM en cobayos de 250-400 g. Para cada ensayo diez animales recibieron solución fisiológica y sirvieron como control. Todos fueron desafiados con la cepa patógena P23790 de virus Junin. Se registró: a temperatura rectal, b peso corporal, c presencia de anticuerpos neutralizantes (AcNT pre y post-vacunación, d respuesta al desafío. Todos los animales vacunados desarrollaron AcNT anti virus Junin (rango = 40- 81920 y sobrevivieron al desafío. En cada grupo control 8/10 animales murieron (día 23.3 ± 5.4 post-desafío. Los cobayos resultaron idénticamente protegidos de una descarga letal de virus Junin por la vacuna importada y los diferentes lotes de C#1 producidos en Argentina.Candid #1 vaccine against Argentine Hemorrhagic Fever produced in USA versus lots of the same vaccine made in Argentina were compared in guinea pigs regarding safety, immunogenicity and protective efficacy against a challenge with pathogenic Junin virus. Lots Nº Exp 3, 7A and 8A of Argentine origin as well as lot TSI 5-1-92 from USA were inoculated in guinea pigs of 250-400 g in two consecutive assays. Ten animals inoculated with saline performed as normal controls in each experiment. Parameters studied were: a temperature; b body weight; c neutralizing antibodies to Junin virus; d response to viral challenge. Animals gained weight and remained normothermic up to the challenge. Guinea pigs that received Candid #1 from any manufacturer elicited neutralizing antibodies to Junin virus (titles from 40 to 81920 and survived to challenge whilst 8/10 animals died in each control group. Data presented demonstrated that Candid #1 vaccines from USA or Argentine

  14. Environmental Information Document: L-reactor reactivation

    Energy Technology Data Exchange (ETDEWEB)

    Mackey, H.E. Jr. (comp.)


    Purpose of this Environmental Information Document is to provide background for assessing environmental impacts associated with the renovation, restartup, and operation of L Reactor at the Savannah River Plant (SRP). SRP is a major US Department of Energy installation for the production of nuclear materials for national defense. The purpose of the restart of L Reactor is to increase the production of nuclear weapons materials, such as plutonium and tritium, to meet projected needs in the nuclear weapons program.

  15. Oscillation Parameters with forthcoming Reactor Neutrino Experiments

    CERN Document Server

    Lasserre, Thierry


    I review the status of the forthcoming reactor neutrino experiments that toe the cutting edge of neutrino oscillation research. Kilometer baseline oscillation experiments (Double Chooz, Daya Bay, and Reno) will soon play a relevant role providing clean information on the last undetermined neutrino mixing angle !13. A 50-70 km baseline reactor neutrino experiment could later provide the best sensitivity to the !12 mixing angle.

  16. Advanced Reactors Transition Program Resource Loaded Schedule

    Energy Technology Data Exchange (ETDEWEB)

    GANTT, D.A.


    The Advanced Reactors Transition (ART) Resource Loaded Schedule (RLS) provides a cost and schedule baseline for managing the project elements within the ART Program. The Fast Flux Test Facility (FETF) activities are delineated through the end of FY 2000, assuming continued standby. The Nuclear Energy (NE) Legacies and Plutonium Recycle Test Reactor (PRTR) activities are delineated through the end of the deactivation process. This revision reflects the 19 Oct 1999 baseline.

  17. Advanced Reactors Transition Program Resource Loaded Schedule

    Energy Technology Data Exchange (ETDEWEB)

    BOWEN, W.W.


    The Advanced Reactors Transition (ART) Resource Loaded Schedule (RLS) provides a cost and schedule baseline for managing the project elements within the ART Program. The Fast Flux Test Facility (FFTF) activities are delineated through the end of FY 2000, assuming continued standby. The Nuclear Energy (NE) Legacies and Plutonium Recycle Test Reactor (PRTR) activities are delineated through the end of the deactivation process. This document reflects the 1 Oct 1999 baseline.

  18. The Daya Bay Reactor Neutrino Experiment

    Institute of Scientific and Technical Information of China (English)


    On Aug.15, 201l, a new large-scale scientific facility in China, Daya Bay Reactor Neutrino Experiment, started to operate. It is located in Daya Bay Nuclear Power Plant in Guangdong Province, around 50kin to both Hong Kong and Shenzhen City. The main scientific goal is to precisely determine the neutrino mixing angle 013 by detecting neutrinos from the reactors at different distances.

  19. Design of an Organic Simplified Nuclear Reactor


    Koroush Shirvan; Eric Forrest


    Numerous advanced reactor concepts have been proposed to replace light water reactors ever since their establishment as the dominant technology for nuclear energy production. While most designs seek to improve cost competitiveness and safety, the implausibility of doing so with affordable materials or existing nuclear fuel infrastructure reduces the possibility of near-term deployment, especially in developing countries. The organic nuclear concept, first explored in the 1950s, offers an attr...

  20. Strengthening IAEA Safeguards for Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Reid, Bruce D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Anzelon, George A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Budlong-Sylvester, Kory [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    During their December 10-11, 2013, workshop in Grenoble France, which focused on the history and future of safeguarding research reactors, the United States, France and the United Kingdom (UK) agreed to conduct a joint study exploring ways to strengthen the IAEA’s safeguards approach for declared research reactors. This decision was prompted by concerns about: 1) historical cases of non-compliance involving misuse (including the use of non-nuclear materials for production of neutron generators for weapons) and diversion that were discovered, in many cases, long after the violations took place and as part of broader pattern of undeclared activities in half a dozen countries; 2) the fact that, under the Safeguards Criteria, the IAEA inspects some reactors (e.g., those with power levels under 25 MWt) less than once per year; 3) the long-standing precedent of States using heavy water research reactors (HWRR) to produce plutonium for weapons programs; 4) the use of HEU fuel in some research reactors; and 5) various technical characteristics common to some types of research reactors that could provide an opportunity for potential proliferators to misuse the facility or divert material with low probability of detection by the IAEA. In some research reactors, for example, such characteristics include rapid on-line refueling, and a core design with room for such a large number of assemblies or targets that it is difficult to detect diversion or undeclared irradiation. In addition, infrastructure associated with research reactors, such as hot cells, where plutonium could be separated, could pose a safeguards challenge because, in some cases, they are not declared (because they are not located in the facility or because nuclear materials are not foreseen to be processed inside) and may not be accessible to inspectors in States without an Additional Protocol in force.

  1. Current status of fast reactor physics

    Energy Technology Data Exchange (ETDEWEB)

    Hummel, H.H.


    The subject of calculation of reactivity coefficients for fast reactors is developed, starting with a discussion of the status of relevant nuclear data and proceeding to the subjects of group cross section generation and of methods of obtaining reactivity coefficients from group cross sections. Reactivity coefficients measured in critical experiments are compared with calculated values. Dependence of reactivity coefficients on reactor design is discussed. Finally, results of the recent international comparison of calculated reactivity coefficients are presented.

  2. Automatic safety rod for reactors. [LMFBR (United States)

    Germer, J.H.


    An automatic safety rod for a nuclear reactor containing neutron absorbing material and designed to be inserted into a reactor core after a loss-of-flow. Actuation is based upon either a sudden decrease in core pressure drop or the pressure drop decreases below a predetermined minimum value. The automatic control rod includes a pressure regulating device whereby a controlled decrease in operating pressure due to reduced coolant flow does not cause the rod to drop into the core.

  3. Monitoring and control of anaerobic reactors

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær;


    control approaches that have been used are comprehensively described. These include simple and adaptive controllers, as well as more recent developments such as fuzzy controllers, knowledge-based controllers and controllers based on neural networks.......The current status in monitoring and control of anaerobic reactors is reviewed. The influence of reactor design and waste composition on the possible monitoring and control schemes is examined. After defining the overall control structure, and possible control objectives, the possible process...


    Avery, R.


    A nuclear reactor having a region operating predominantly on fast neutrons and another region operating predominantly on slow neutrons is described. The fast region is a plutonium core and the slow region is a natural uranium blanket around the core. Both of these regions are free of moderator. A moderating reflector surrounds the uranium blanket. The moderating material and thickness of the reflector are selected so that fissions in the uranium blanket make a substantial contribution to the reactivity of the reactor.

  5. Short-baseline reactor neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Mariani, C. [Department of Physics, Columbia University, New York, NY 10027 (United States)


    The neutrino mixing angle {theta}13 is currently a high-priority topic in the field of neutrino physics, with three different reactor neutrino experiments under way, searching for neutrino oscillations induced by this angle. A description of the reactor experiments searching for a non-zero value of {theta}13 is given, together with a discussion of their sensitivity within the next few years.

  6. Reactor Simulator Integration and Testing (United States)

    Schoenfield, M. P.; Webster, K. L.; Pearson, J. B.


    As part of the Nuclear Systems Office Fission Surface Power Technology Demonstration Unit (TDU) project, a reactor simulator (RxSim) test loop was designed and built to perform integrated testing of the TDU components. In particular, the objectives of RxSim testing were to verify the operation of the core simulator, the instrumentation and control system, and the ground support gas and vacuum test equipment. In addition, it was decided to include a thermal test of a cold trap purification design and a pump performance test at pump voltages up to 150 V because the targeted mass flow rate of 1.75 kg/s was not obtained in the RxSim at the originally constrained voltage of 120 V. This Technical Memorandum summarizes RxSim testing. The gas and vacuum ground support test equipment performed effectively in NaK fill, loop pressurization, and NaK drain operations. The instrumentation and control system effectively controlled loop temperature and flow rates or pump voltage to targeted settings. The cold trap design was able to obtain the targeted cold temperature of 480 K. An outlet temperature of 636 K was obtained, which was lower than the predicted 750 K but 156 K higher than the cold temperature, indicating the design provided some heat regeneration. The annular linear induction pump tested was able to produce a maximum flow rate of 1.53 kg/s at 800 K when operated at 150 V and 53 Hz.

  7. Solid oxide electrochemical reactor science.

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Neal P. (Colorado School of Mines, Golden, CO); Stechel, Ellen Beth; Moyer, Connor J. (Colorado School of Mines, Golden, CO); Ambrosini, Andrea; Key, Robert J. (Colorado School of Mines, Golden, CO)


    Solid-oxide electrochemical cells are an exciting new technology. Development of solid-oxide cells (SOCs) has advanced considerable in recent years and continues to progress rapidly. This thesis studies several aspects of SOCs and contributes useful information to their continued development. This LDRD involved a collaboration between Sandia and the Colorado School of Mines (CSM) ins solid-oxide electrochemical reactors targeted at solid oxide electrolyzer cells (SOEC), which are the reverse of solid-oxide fuel cells (SOFC). SOECs complement Sandia's efforts in thermochemical production of alternative fuels. An SOEC technology would co-electrolyze carbon dioxide (CO{sub 2}) with steam at temperatures around 800 C to form synthesis gas (H{sub 2} and CO), which forms the building blocks for a petrochemical substitutes that can be used to power vehicles or in distributed energy platforms. The effort described here concentrates on research concerning catalytic chemistry, charge-transfer chemistry, and optimal cell-architecture. technical scope included computational modeling, materials development, and experimental evaluation. The project engaged the Colorado Fuel Cell Center at CSM through the support of a graduate student (Connor Moyer) at CSM and his advisors (Profs. Robert Kee and Neal Sullivan) in collaboration with Sandia.

  8. Thermal-hydraulic interfacing code modules for CANDU reactors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.S.; Gold, M.; Sills, H. [Ontario Hydro Nuclear, Toronto (Canada)] [and others


    The approach for CANDU reactor safety analysis in Ontario Hydro Nuclear (OHN) and Atomic Energy of Canada Limited (AECL) is presented. Reflecting the unique characteristics of CANDU reactors, the procedure of coupling the thermal-hydraulics, reactor physics and fuel channel/element codes in the safety analysis is described. The experience generated in the Canadian nuclear industry may be useful to other types of reactors in the areas of reactor safety analysis.

  9. Development of computer simulator for coal liquefaction reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yawata, T.; Kobayashi, M.; Ohi, S.; Itho, H.; Hiraide, M. [Nippon Oil Co., Ltd., Tokyo (Japan)


    The computer simulator for a coal liquefaction reactor is a useful engineering tool to analyse the data of such reactors. The authors applied this technique to a reactor in the NEDOL process to predict the performance of the reactor, and to assist in the design of a reactor for demonstration plant. The development program of the simulator and its utilization plan are discussed. 4 figs., 2 tabs.

  10. Optimally moderated nuclear fission reactor and fuel source therefor (United States)

    Ougouag, Abderrafi M.; Terry, William K.; Gougar, Hans D.


    An improved nuclear fission reactor of the continuous fueling type involves determining an asymptotic equilibrium state for the nuclear fission reactor and providing the reactor with a moderator-to-fuel ratio that is optimally moderated for the asymptotic equilibrium state of the nuclear fission reactor; the fuel-to-moderator ratio allowing the nuclear fission reactor to be substantially continuously operated in an optimally moderated state.

  11. Design options for a bunsen reactor.

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Robert Charles


    This work is being performed for Matt Channon Consulting as part of the Sandia National Laboratories New Mexico Small Business Assistance Program (NMSBA). Matt Channon Consulting has requested Sandia's assistance in the design of a chemical Bunsen reactor for the reaction of SO2, I2 and H2O to produce H2SO4 and HI with a SO2 feed rate to the reactor of 50 kg/hour. Based on this value, an assumed reactor efficiency of 33%, and kinetic data from the literature, a plug flow reactor approximately 1%E2%80%9D diameter and and 12 inches long would be needed to meet the specification of the project. Because the Bunsen reaction is exothermic, heat in the amount of approximately 128,000 kJ/hr would need to be removed using a cooling jacket placed around the tubular reactor. The available literature information on Bunsen reactor design and operation, certain support equipment needed for process operation and a design that meet the specification of Matt Channon Consulting are presented.

  12. Decommissioning of the Salaspils Research Reactor

    Directory of Open Access Journals (Sweden)

    Abramenkovs Andris


    Full Text Available In May 1995, the Latvian government decided to shut down the Salaspils Research Reactor and to dispense with nuclear energy in the future. The reactor has been out of operation since July 1998. A conceptual study on the decommissioning of the Salaspils Research Reactor was drawn up by Noell-KRC-Energie- und Umwelttechnik GmbH in 1998-1999. On October 26th, 1999, the Latvian government decided to start the direct dismantling to “green-field” in 2001. The upgrading of the decommissioning and dismantling plan was carried out from 2003-2004, resulting in a change of the primary goal of decommissioning. Collecting and conditioning of “historical” radioactive wastes from different storages outside and inside the reactor hall became the primary goal. All radioactive materials (more than 96 tons were conditioned for disposal in concrete containers at the radioactive wastes depository “Radons” at the Baldone site. Protective and radiation measurement equipment of the personnel was upgraded significantly. All non-radioactive equipment and materials outside the reactor buildings were released for clearance and dismantled for reuse or conventional disposal. Contaminated materials from the reactor hall were collected and removed for clearance measurements on a weekly basis.

  13. MOX in reactors: present and future

    Energy Technology Data Exchange (ETDEWEB)

    Arslan, Marc; Gros, Jean Pierre [AREVA NC - 33 rue La Fayette, 75009 Paris (France); Niquille, Aurelie; Marincic, Alexis [AREVA NP - Tour AREVA, 1 Place Jean Millier 92084 Paris La Defense (France)


    In Europe, MOX fuel has been supplied by AREVA for more than 30 years, to 36 reactors: 21 in France, 10 in Germany, 3 in Switzerland, 2 in Belgium. For the present and future, recycling is compulsory in the frame of sustainable development of nuclear energy. By 2030 the overall volume of used fuel will reach about 400 000 t worldwide. Their plutonium and uranium content represents a huge resource of energy to recycle. That is the reason why, the European Utilities issued an EUR (European Utilities Requirement) demanding new builds reactors to be able of using MOX Fuel Assemblies in up to 50 % of the core. AREVA GEN3+ reactors, like EPR{sup TM} or ATMEA{sup TM} designed with MHI partnership, are designed to answer any utility need of MOX recycling. The example of the EPR{sup TM} reactor operated with 100 % MOX core optimized for MOX recycling will be presented. A standard EPR{sup TM} can be operated with 100 % MOX core using an advanced homogeneous MOX (single Pu content) with highly improved performances (burn-up and Cycle length). The adaptations needed and the main operating and safety reactor features will be presented. AREVA offers the utilities throughout the world, fuel supply (UO{sub 2}, ERU, MOX), and reactors designed with all the needed capability for recycling. For each country and each utility, an adapted global solution, competitive and non proliferant can be proposed. (authors)

  14. Moving hot cell for LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kanbe, Mitsuru


    A moving hot cell for an LMFBR type reactor is made movable on a reactor operation floor between a position just above the reactor container and a position retreated therefrom. Further, it comprises an overhung portion which can incorporate a spent fuel just thereunder, and a crane for moving a fuel assembly between a spent fuel cask and a reactor container. Further, an opening/closing means having a shielding structure is disposed to the bottom portion and the overhung portion thereof, to provide a sealing structure, in which only the receiving port for the spent fuel cask faces to the inner side, and the cask itself is disposed at the outside. Upon exchange of fuels, the movable hot cell is placed just above the reactor to take out the spent fuels, so that a region contaminated with primary sodium is limited within the hot cell. On the other hand, upon maintenance and repair for equipments, the hot cell is moved, thereby enabling to provide a not contaminated reactor operation floor. (N.H.).

  15. Supply of enriched uranium for research reactors

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, H. [NUKEM GmbH, Alzenau (Germany)


    Since the RERTR-meeting In Newport/USA in 1990 the author delivered a series of papers in connection with the fuel cycle for research reactors dealing with its front-end. In these papers the author underlined the need for unified specifications for enriched uranium metal suitable for the production of fuel elements and made proposals with regard to the re-use of in Europe reprocessed highly enriched uranium. With regard to the fuel cycle of research reactors the research reactor community was since 1989 more concentrating on the problems of its back-end since the USA stopped the acceptance of spent research reactor fuel on December 31, 1988. Now, since it is apparent that these back-end problem have been solved by AEA`s ability to reprocess and the preparedness of the USA to again accept physically spent research reactor fuel the author is focusing with this paper again on the front-end of the fuel cycle on the question whether there is at all a safe supply of low and high enriched uranium for research reactors in the future.

  16. A nanoliter-scale open chemical reactor. (United States)

    Galas, Jean-Christophe; Haghiri-Gosnet, Anne-Marie; Estévez-Torres, André


    An open chemical reactor is a container that exchanges matter with the exterior. Well-mixed open chemical reactors, called continuous stirred tank reactors (CSTR), have been instrumental for investigating the dynamics of out-of-equilibrium chemical processes, such as oscillations, bistability, and chaos. Here, we introduce a microfluidic CSTR, called μCSTR, that reduces reagent consumption by six orders of magnitude. It consists of an annular reactor with four inlets and one outlet fabricated in PDMS using multi-layer soft lithography. A monolithic peristaltic pump feeds fresh reagents into the reactor through the inlets. After each injection the content of the reactor is continuously mixed with a second peristaltic pump. The efficiency of the μCSTR is experimentally characterized using a bromate, sulfite, ferrocyanide pH oscillator. Simulations accounting for the digital injection process are in agreement with experimental results. The low consumption of the μCSTR will be advantageous for investigating out-of-equilibrium dynamics of chemical processes involving biomolecules. These studies have been scarce so far because a miniaturized version of a CSTR was not available.

  17. Uncertainty quantification approaches for advanced reactor analyses.

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, L. L.; Nuclear Engineering Division


    The original approach to nuclear reactor design or safety analyses was to make very conservative modeling assumptions so as to ensure meeting the required safety margins. Traditional regulation, as established by the U. S. Nuclear Regulatory Commission required conservatisms which have subsequently been shown to be excessive. The commission has therefore moved away from excessively conservative evaluations and has determined best-estimate calculations to be an acceptable alternative to conservative models, provided the best-estimate results are accompanied by an uncertainty evaluation which can demonstrate that, when a set of analysis cases which statistically account for uncertainties of all types are generated, there is a 95% probability that at least 95% of the cases meet the safety margins. To date, nearly all published work addressing uncertainty evaluations of nuclear power plant calculations has focused on light water reactors and on large-break loss-of-coolant accident (LBLOCA) analyses. However, there is nothing in the uncertainty evaluation methodologies that is limited to a specific type of reactor or to specific types of plant scenarios. These same methodologies can be equally well applied to analyses for high-temperature gas-cooled reactors and to liquid metal reactors, and they can be applied to steady-state calculations, operational transients, or severe accident scenarios. This report reviews and compares both statistical and deterministic uncertainty evaluation approaches. Recommendations are given for selection of an uncertainty methodology and for considerations to be factored into the process of evaluating uncertainties for advanced reactor best-estimate analyses.

  18. Antineutrino reactor safeguards - a case study

    CERN Document Server

    Christensen, Eric; Jaffke, Patrick


    Antineutrinos have been proposed as a means of reactor safeguards for more than 30 years and there has been impressive experimental progress in neutrino detection. In this paper we conduct, for the first time, a case study of the application of antineutrino safeguards to a real-world scenario - the North Korean nuclear crisis in 1994. We derive detection limits to a partial or full core discharge in 1989 based on actual IAEA safeguards access and find that two independent methods would have yielded positive evidence for a second core with very high confidence. To generalize our results, we provide detailed estimates for the sensitivity to the plutonium content of various types of reactors, including most types of plutonium production reactors, based on detailed reactor simulations. A key finding of this study is that a wide class of reactors with a thermal power of less than 0.1-1 GWth can be safeguarded achieving IAEA goals for quantitative sensitivity and timeliness with detectors right outside the reactor ...

  19. FBR and RBR particle bed space reactors

    Energy Technology Data Exchange (ETDEWEB)

    Powell, J.R.; Botts, T.E.


    Compact, high-performance nuclear reactor designs based on High-Temperature Gas Reactors (HTGRs) particulate fuel are investigated. The large surface area available with the small-diameter (approx. 500 microns) particulate fuel allows very high power densities (MW's/liter), small temperature differences between fuel and coolant (approx. 10/sup 0/K), high coolant-outlet temperatures (1500 to 3000/sup 0/K, depending on design), and fast reactor startup (approx. 2 to 3 seconds). Two reactor concepts are developed - the Fixed Bed Reactor (FBR), where the fuel particles are packed into a thin annular bed between two porous cylindrical drums, and the Rotating Bed Reactor (RBR), where the fuel particles are held inside a cold rotating (typically approx. 500 rpm) porous cylindrical drum. The FBR can operate steady-state in the closed-cycle He-cooled mode or in the open-cycle H/sub 2/-cooled mode. The RBR will operate only in the open-cycle H/sub 2/-cooled mode.

  20. Technology, Safety and Costs of Decommissioning Nuclear Reactors At Multiple-Reactor Stations

    Energy Technology Data Exchange (ETDEWEB)

    Wittenbrock, N. G.


    Safety and cost information is developed for the conceptual decommissioning of large (1175-MWe) pressurized water reactors (PWRs) and large (1155-MWe) boiling water reactors {BWRs) at multiple-reactor stations. Three decommissioning alternatives are studied: DECON (immediate decontamination), SAFSTOR (safe storage followed by deferred decontamination), and ENTOMB (entombment). Safety and costs of decommissioning are estimated by determining the impact of probable features of multiple-reactor-station operation that are considered to be unavailable at a single-reactor station, and applying these estimated impacts to the decommissioning costs and radiation doses estimated in previous PWR and BWR decommissioning studies. The multiple-reactor-station features analyzed are: the use of interim onsite nuclear waste storage with later removal to an offsite nuclear waste disposal facility, the use of permanent onsite nuclear waste disposal, the dedication of the site to nuclear power generation, and the provision of centralized services. Five scenarios for decommissioning reactors at a multiple-reactor station are investigated. The number of reactors on a site is assumed to be either four or ten; nuclear waste disposal is varied between immediate offsite disposal, interim onsite storage, and immediate onsite disposal. It is assumed that the decommissioned reactors are not replaced in one scenario but are replaced in the other scenarios. Centralized service facilities are provided in two scenarios but are not provided in the other three. Decommissioning of a PWR or a BWR at a multiple-reactor station probably will be less costly and result in lower radiation doses than decommissioning an identical reactor at a single-reactor station. Regardless of whether the light water reactor being decommissioned is at a single- or multiple-reactor station: • the estimated occupational radiation dose for decommissioning an LWR is lowest for SAFSTOR and highest for DECON • the estimated