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Sample records for ribbon seal histriophoca

  1. Carbon sources and trophic relationships of ice seals during recent environmental shifts in the Bering Sea.

    Science.gov (United States)

    Wang, Shiway W; Springer, Alan M; Budge, Suzanne M; Horstmann, Lara; Quakenbush, Lori T; Wooller, Matthew J

    2016-04-01

    Dramatic multiyear fluctuations in water temperature and seasonal sea ice extent and duration across the Bering-Chukchi continental shelf have occurred in this century, raising a pressing ecological question: Do such environmental changes alter marine production processes linking primary producers to upper trophic-level predators? We examined this question by comparing the blubber fatty acid (FA) composition and stable carbon isotope ratios of individual FA (δ¹³CFA) of adult ringed seals (Pusa hispida), bearded seals (Erignathus barbatus), spotted seals (Phoca largha), and ribbon seals (Histriophoca fasciata), collectively known as "ice seals," sampled during an anomalously warm, low sea ice period in 2002-2005 in the Bering Sea and a subsequent cold, high sea ice period in 2007-2010. δ¹³C(FA) values, used to estimate the contribution to seals of carbon derived from sea ice algae (sympagic production) relative to that derived from water column phytoplankton (pelagic production), indicated that during the cold period, sympagic production accounted for 62-80% of the FA in the blubber of bearded seals, 51-62% in spotted seals, and 21-60% in ringed seals. Moreover, the δ¹³CFA values of bearded seals indicated a greater incorporation of sympagic FAs during the cold period than the warm period. This result provides the first empirical evidence of an ecosystem-scale effect of a putative change in sympagic production in the Western Arctic. The FA composition of ice seals showed clear evidence of resource partitioning among ringed, bearded, and spotted seals, and little niche separation between spotted and ribbon seals, which is consistent with previous studies. Despite interannual variability, the FA composition of ringed and bearded seals showed little evidence of differences in diet between the warm and cold periods. The findings that sympagic production contributes significantly to food webs supporting ice seals, and that the contribution apparently is less in

  2. Brucella Antibodies in Alaskan True Seals and Eared Seals—Two Different Stories

    Directory of Open Access Journals (Sweden)

    Ingebjørg H. Nymo

    2018-01-01

    Full Text Available Brucella pinnipedialis was first isolated from true seals in 1994 and from eared seals in 2008. Although few pathological findings have been associated with infection in true seals, reproductive pathology including abortions, and the isolation of the zoonotic strain type 27 have been documented in eared seals. In this study, a Brucella enzyme-linked immunosorbent assay (ELISA and the Rose Bengal test (RBT were initially compared for 206 serum samples and a discrepancy between the tests was found. Following removal of lipids from the serum samples, ELISA results were unaltered while the agreement between the tests was improved, indicating that serum lipids affected the initial RBT outcome. For the remaining screening, we used ELISA to investigate the presence of Brucella antibodies in sera of 231 eared and 1,412 true seals from Alaskan waters sampled between 1975 and 2011. In eared seals, Brucella antibodies were found in two Steller sea lions (Eumetopias jubatus (2% and none of the 107 Northern fur seals (Callorhinus ursinus. The low seroprevalence in eared seals indicate a low level of exposure or lack of susceptibility to infection. Alternatively, mortality due to the Brucella infection may remove seropositive animals from the population. Brucella antibodies were detected in all true seal species investigated; harbor seals (Phoca vitulina (25%, spotted seals (Phoca largha (19%, ribbon seals (Histriophoca fasciata (16%, and ringed seals (Pusa hispida hispida (14%. There was a low seroprevalence among pups, a higher seroprevalence among juveniles, and a subsequent decreasing probability of seropositivity with age in harbor seals. Similar patterns were present for the other true seal species; however, solid conclusions could not be made due to sample size. This pattern is in accordance with previous reports on B. pinnipedialis infections in true seals and may suggest environmental exposure to B. pinnipedialis at the juvenile stage, with a

  3. Serologic evidence of Brucella infection in pinnipeds along the coast of Hokkaido, the northernmost main island of Japan.

    Science.gov (United States)

    Abe, Erika; Ohishi, Kazue; Ishinazaka, Tsuyoshi; Fujii, Kei; Maruyama, Tadashi

    2017-04-01

    Brucella infection in Hokkaido was serologically surveyed in four species of pinnipeds inhabiting Cape Erimo during 2008-2013 and the Shiretoko Peninsula in 1999 by ELISA using Brucella abortus and B. canis as antigens. Anti-Brucella positive sera showed higher absorbance to B. abortus than B. canis in almost all samples. Anti-B. abortus antibodies were detected in serum samples from 24% (n = 55) of Western Pacific harbor seals (Phoca vitulina stejnegeri) in Cape Erimo and from 66% (n = 41) of spotted seals (P. largha), 15% (n = 20) of ribbon seals (Histriophoca fasciata) and 18% (n = 17) of Western Steller's sea lions (Eumetopias jubatus jubatus) in the Shiretoko Peninsula. Anti-Brucella antibodies were detected at higher absorbance in 1- to 4-year-old harbor seals than in the pups and mature animals, suggesting either that Brucella infection mainly occurs after weaning or that it is maternally transmitted to pups with premature or suppressed immunity. Anti-Brucella antibodies were detected in both immature and mature spotted seals and ribbon seals, with higher absorbance in the former. The antibodies were detected only in mature Western Steller's sea lions. Western blot analysis of the serum samples showed some differences in band appearances, namely discrete versus smeary, and in the number of bands, indicating that multiple different Brucella may be prevalent in pinnipeds in Hokkaido. Alternatively, the Brucella of pinnipeds may have some intra-species diversity. © 2017 The Societies and John Wiley & Sons Australia, Ltd.

  4. Hydrostatic extrusion of Cu-Ag melt spun ribbon

    Science.gov (United States)

    Hill, Mary Ann; Bingert, John F.; Bingert, Sherri A.; Thoma, Dan J.

    1998-01-01

    The present invention provides a method of producing high-strength and high-conductance copper and silver materials comprising the steps of combining a predetermined ratio of the copper with the silver to produce a composite material, and melt spinning the composite material to produce a ribbon of copper and silver. The ribbon of copper and silver is heated in a hydrogen atmosphere, and thereafter die pressed into a slug. The slug then is placed into a high-purity copper vessel and the vessel is sealed with an electron beam. The vessel and slug then are extruded into wire form using a cold hydrostatic extrusion process.

  5. Ribbon curling

    Science.gov (United States)

    Juel, Anne; Prior, Chris; Moussou, Julien; Chakrabarti, Buddhapriya; Jensen, Oliver

    The procedure of curling a ribbon by running it over a sharp blade is commonly used when wrapping presents. Despite its ubiquity, a quantitative explanation of this everyday phenomenon is still lacking. We address this using experiment and theory, examining the dependence of ribbon curvature on blade curvature, the longitudinal load imposed on the ribbon and the speed of pulling. Experiments in which a ribbon is drawn steadily over a blade under a fixed load show that the ribbon curvature is generated over a restricted range of loads, the curvature/load relationship can be non-monotonic, and faster pulling (under a constant imposed load) results in less tightly curled ribbons. We develop a theoretical model that captures these features, building on the concept that the ribbon under the imposed deformation undergoes differential plastic stretching across its thickness, resulting in a permanently curved shape. The model identifies factors that optimize curling and clarifies the physical mechanisms underlying the ribbon's nonlinear response to an apparently simple deformation.

  6. Bering-Okhotsk Seal Survey (BOSS) Color Imagery (2012-13)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — US surveys were conducted of the Bering Sea pack ice for bearded, spotted, ribbon, and ringed seals using digital cameras and thermal imagers mounted in the belly...

  7. Bering-Okhotsk Seal Survey (BOSS) Identified Hot Spots (2012-13)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — US surveys were conducted of the Bering Sea pack ice for bearded, spotted, ribbon, and ringed seals using digital cameras and thermal imagers mounted in the belly...

  8. Bering Sea Helicopter Surveys for Ice-Associated Seals (2007-08)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In the spring of 2007 and 2008, researchers from the Alaska Fisheries Science Center conducted aerial surveys for ribbon, bearded, and spotted seals in the US sector...

  9. Baffles Promote Wider, Thinner Silicon Ribbons

    Science.gov (United States)

    Seidensticker, Raymond G.; Mchugh, James P.; Hundal, Rolv; Sprecace, Richard P.

    1989-01-01

    Set of baffles just below exit duct of silicon-ribbon-growing furnace reduces thermal stresses in ribbons so wider ribbons grown. Productivity of furnace increased. Diverts plume of hot gas from ribbon and allows cooler gas from top of furnace to flow around. Also shields ribbon from thermal radiation from hot growth assembly. Ribbon cooled to lower temperature before reaching cooler exit duct, avoiding abrupt drop in temperature as entering duct.

  10. Elongation of Flare Ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Jiong; Longcope, Dana W. [Department of Physics, Montana State University, Bozeman MT (United States); Cassak, Paul A. [Department of Physics and Astronomy, West Virginia University, Morgantown WV (United States); Priest, Eric R. [School of Mathematics and Statistics, University of St. Andrews, Fife KY16 9SS, Scotland (United Kingdom)

    2017-03-20

    We present an analysis of the apparent elongation motion of flare ribbons along the polarity inversion line (PIL), as well as the shear of flare loops in several two-ribbon flares. Flare ribbons and loops spread along the PIL at a speed ranging from a few to a hundred km s{sup −1}. The shear measured from conjugate footpoints is consistent with the measurement from flare loops, and both show the decrease of shear toward a potential field as a flare evolves and ribbons and loops spread along the PIL. Flares exhibiting fast bidirectional elongation appear to have a strong shear, which may indicate a large magnetic guide field relative to the reconnection field in the coronal current sheet. We discuss how the analysis of ribbon motion could help infer properties in the corona where reconnection takes place.

  11. Gas-Jet Meniscus Control in Ribbon Growth

    Science.gov (United States)

    Zoutendyk, J. A.; Vonroos, O.

    1983-01-01

    Gas jet used to control shape of meniscus and thus to regulate ribbon thickness in vertical silicon-ribbon growth. Gas jet also cools ribbon, increasing maximum possible pull speed for silicon, contact angle of 11 degrees plus or minus 1 degree required for constant thickness ribbon growth. Cooling effect of gas jet increases maximum possible pull speed.

  12. Numerical Simulation Of Silicon-Ribbon Growth

    Science.gov (United States)

    Woda, Ben K.; Kuo, Chin-Po; Utku, Senol; Ray, Sujit Kumar

    1987-01-01

    Mathematical model includes nonlinear effects. In development simulates growth of silicon ribbon from melt. Takes account of entire temperature and stress history of ribbon. Numerical simulations performed with new model helps in search for temperature distribution, pulling speed, and other conditions favoring growth of wide, flat, relatively defect-free silicon ribbons for solar photovoltaic cells at economically attractive, high production rates. Also applicable to materials other than silicon.

  13. Chirality effect in disordered graphene ribbon junctions

    International Nuclear Information System (INIS)

    Long Wen

    2012-01-01

    We investigate the influence of edge chirality on the electronic transport in clean or disordered graphene ribbon junctions. By using the tight-binding model and the Landauer-Büttiker formalism, the junction conductance is obtained. In the clean sample, the zero-magnetic-field junction conductance is strongly chirality-dependent in both unipolar and bipolar ribbons, whereas the high-magnetic-field conductance is either chirality-independent in the unipolar or chirality-dependent in the bipolar ribbon. Furthermore, we study the disordered sample in the presence of magnetic field and find that the junction conductance is always chirality-insensitive for both unipolar and bipolar ribbons with adequate disorders. In addition, the disorder-induced conductance plateaus can exist in all chiral bipolar ribbons provided the disorder strength is moderate. These results suggest that we can neglect the effect of edge chirality in fabricating electronic devices based on the magnetotransport in a disordered graphene ribbon. (paper)

  14. 78 FR 41371 - Endangered and Threatened Wildlife; Determination on Whether To List the Ribbon Seal as a...

    Science.gov (United States)

    2013-07-10

    ... number and volume of erythrocytes (red blood cells) and the highest blood hemoglobin (oxygen-transport protein in red blood cells) of all seals, as well as larger internal organs than those of other seals...; Burns, 1981), during which time mothers continue to feed, sometimes leaving their pups unattended on the...

  15. Dislocation dynamics of web type silicon ribbon

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, Jr, O W; Tsai, C T; DeAngelis, R J

    1987-03-01

    Silicon ribbon grown by the dendritic web process passes through a rapidly changing thermal profile in the growth direction. This rapidly changing profile induces stresses which produce changes in the dislocation density in the ribbon. A viscoplastic material response function (Haasen-Sumino model) is used herein to calculate the stresses and the dislocation density at each point in the silicon ribbon. The residual stresses are also calculated.

  16. Ca(2+) influx and neurotransmitter release at ribbon synapses.

    Science.gov (United States)

    Cho, Soyoun; von Gersdorff, Henrique

    2012-01-01

    Ca(2+) influx through voltage-gated Ca(2+) channels triggers the release of neurotransmitters at presynaptic terminals. Some sensory receptor cells in the peripheral auditory and visual systems have specialized synapses that express an electron-dense organelle called a synaptic ribbon. Like conventional synapses, ribbon synapses exhibit SNARE-mediated exocytosis, clathrin-mediated endocytosis, and short-term plasticity. However, unlike non-ribbon synapses, voltage-gated L-type Ca(2+) channel opening at ribbon synapses triggers a form of multiquantal release that can be highly synchronous. Furthermore, ribbon synapses appear to be specialized for fast and high throughput exocytosis controlled by graded membrane potential changes. Here we will discuss some of the basic aspects of synaptic transmission at different types of ribbon synapses, and we will emphasize recent evidence that auditory and retinal ribbon synapses have marked differences. This will lead us to suggest that ribbon synapses are specialized for particular operating ranges and frequencies of stimulation. We propose that different types of ribbon synapses transfer diverse rates of sensory information by expressing a particular repertoire of critical components, and by placing them at precise and strategic locations, so that a continuous supply of primed vesicles and Ca(2+) influx leads to fast, accurate, and ongoing exocytosis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Are All Flare Ribbons Simply Connected to the Corona?

    Energy Technology Data Exchange (ETDEWEB)

    Judge, Philip G. [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States); Paraschiv, Alin; Lacatus, Daniela; Donea, Alina [Monash Center for Astrophysics, School of Mathematical Science, Monash University, Victoria 3800 (Australia); Lindsey, Charlie, E-mail: judge@ucar.edu, E-mail: alina.donea@monash.edu, E-mail: alin.paraschiv@monash.edu, E-mail: daniela.lacatus@monash.edu, E-mail: indsey@cora.nwra.com [Northwest Research Associates, 3380 Mitchell Lane, Boulder, CO 80301 (United States)

    2017-04-01

    We consider the observational basis for the belief that flare ribbons in the chromosphere result from energy transport from the overlying corona. We study ribbons of small flares using magnetic and intensity data from the Hinode , Solar Dynamics Observatory , and IRIS missions. While most ribbons appear connected to the corona and overlie regions of significant vertical magnetic field, we examine one ribbon with no clear evidence for such connections. Evolving horizontal magnetic fields seen with Hinode suggest that reconnection with preexisting fields below the corona can explain the data. The identification of just one, albeit small, ribbon, with no apparent connection to the corona, leads us to conclude that at least two mechanisms are responsible for the heating that leads to flare ribbon emission.

  18. Geothermal Technologies Program Blue Ribbon Panel Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2011-06-17

    The Geothermal Technologies Program assembled a geothermal Blue Ribbon Panel on March 22-23, 2011 in Albuquerque, New Mexico for a guided discussion on the future of geothermal energy in the United States and the role of the DOE Program. The Geothermal Blue Ribbon Panel Report captures the discussions and recommendations of the experts. An addendum is available here: http://www.eere.energy.gov/geothermal/pdfs/gtp_blue_ribbon_panel_report_addendum10-2011.pdf

  19. Diagrammatic documentation for ribbon computing in Microsoft Office

    Directory of Open Access Journals (Sweden)

    Kaveh Farbeh-Tabrizi

    Full Text Available In 2007 Microsoft changed the graphical user interface of MS Office, and moved away from the long -established drop down menu approach to a ribbon graphical user interface. There have been mixed reactions to Microsoft\\'s ribbon interface. Ericson (2006 mentioned that even the experienced user might have difficulty adopting the interface, and Dostal (2010 concluded that the biggest issue with the Ribbon User Interface is to get accustomed to a redesigned user interface. Reaction to this change was negative among our new and current students. For years the students had tried to memorise how to apply the right commands in Microsoft Office applications by selecting the correct items from the dropdown menus of the WIMP (windows, icons, menus, pointer interface, and now that they were confronted with the new interface their confusion had begun to slow their progress down. The major effect in transition from the traditional WIMP interface to the Ribbon interface had created a difficulty for most students who had their original training with the older versions of MS Office software, as they were not able to locate the commands that they had learnt with the earlier versions of the MS Office in the new Ribbon interfaced version. The shrinking nature of the ribbon that would hide some commands on the ribbon when the resolution of the screen changes was also confusing for those students as they could not quickly locate the command they were looking for because the Ribbon had compacted them to save space. For both new students and also more experienced ones, the approach to learning the Ribbon Interface seemed to be difficult due to the fact that they had to memorise the hierarchy of tab names, group names and then the commands. This led us to enhance our current teaching methods to try to deal with this change.

  20. ON THE GEOMETRY OF THE IBEX RIBBON

    Energy Technology Data Exchange (ETDEWEB)

    Sylla, Adama; Fichtner, Horst [Institut für Theoretische Physik IV, Ruhr-Universität Bochum, D-44780 Bochum (Germany)

    2015-10-01

    The Energetic Neutral Atom (ENA) full-sky maps obtained with the Interstellar Boundary Explorer (IBEX) show an unexpected bright narrow band of increased intensity. This so-called ENA ribbon results from charge exchange of interstellar neutral atoms with protons in the outer heliosphere or beyond. Among other hypotheses it has been argued that this ribbon may be related to a neutral density enhancement, or H-wave, in the local interstellar medium. Here we quantitatively demonstrate, on the basis of an analytical model of the principal large-scale heliospheric structure, that this scenario for the ribbon formation leads to results that are fully consistent with the observed location of the ribbon in the full-sky maps at all energies detected with high-energy sensor IBEX-Hi.

  1. Observations and Numerical Modeling of the Jovian Ribbon

    Science.gov (United States)

    Cosentino, R. G.; Simon, A.; Morales-Juberias, R.; Sayanagi, K. M.

    2015-01-01

    Multiple wavelength observations made by the Hubble Space Telescope in early 2007 show the presence of a wavy, high-contrast feature in Jupiter's atmosphere near 30 degrees North. The "Jovian Ribbon," best seen at 410 nanometers, irregularly undulates in latitude and is time-variable in appearance. A meridional intensity gradient algorithm was applied to the observations to track the Ribbon's contour. Spectral analysis of the contour revealed that the Ribbon's structure is a combination of several wavenumbers ranging from k equals 8-40. The Ribbon is a dynamic structure that has been observed to have spectral power for dominant wavenumbers which vary over a time period of one month. The presence of the Ribbon correlates with periods when the velocity of the westward jet at the same location is highest. We conducted numerical simulations to investigate the stability of westward jets of varying speed, vertical shear, and background static stability to different perturbations. A Ribbon-like morphology was best reproduced with a 35 per millisecond westward jet that decreases in amplitude for pressures greater than 700 hectopascals and a background static stability of N equals 0.005 per second perturbed by heat pulses constrained to latitudes south of 30 degrees North. Additionally, the simulated feature had wavenumbers that qualitatively matched observations and evolved throughout the simulation reproducing the Jovian Ribbon's dynamic structure.

  2. The ribbon microphone - an educational aid: use of a ribbon microphone to teach multi-discipline computer simulation skills

    CSIR Research Space (South Africa)

    Van Wyk, Marius

    2016-07-01

    Full Text Available The ribbon microphone serves as an excellent aid to learn computer simulation and computational skills. Simulation of this seemingly simple device is all but trivial. The ribbon microphone is an all-in-one example for simulations in acoustics...

  3. Electrostatics-Driven Hierarchical Buckling of Charged Flexible Ribbons.

    Science.gov (United States)

    Yao, Zhenwei; Olvera de la Cruz, Monica

    2016-04-08

    We investigate the rich morphologies of an electrically charged flexible ribbon, which is a prototype for many beltlike structures in biology and nanomaterials. Long-range electrostatic repulsion is found to govern the hierarchical buckling of the ribbon from its initially flat shape to its undulated and out-of-plane twisted conformations. In this process, the screening length is the key controlling parameter, suggesting that a convenient way to manipulate the ribbon morphology is simply to change the salt concentration. We find that these shapes originate from the geometric effect of the electrostatic interaction, which fundamentally changes the metric over the ribbon surface. We also identify the basic modes by which the ribbon reshapes itself in order to lower the energy. The geometric effect of the physical interaction revealed in this Letter has implications for the shape design of extensive ribbonlike materials in nano- and biomaterials.

  4. Carbon nanotube fiber spun from wetted ribbon

    Science.gov (United States)

    Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi

    2014-04-29

    A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

  5. Magnetic and sensitive magnetoelastic properties of Finemet nanostructured ribbon

    International Nuclear Information System (INIS)

    Pham Duc Thang; Hoang Hai Duong; Nguyen Hoang Nghi

    2009-01-01

    Soft-magnetic Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 (Finemet) ribbon has been fabricated by using melt-spinning techniques. After annealing at suitable temperature the ribbon changes from an amorphous to crystalline state which related to the formation of Fe nanocrystallites. Study on the magnetic and magnetoelastic properties of the ribbon is presented. Furthermore, based on the fabricated ribbon stress sensors are simply constructed. The sensors showed high sensitivity of 3.8 mV/MPa as well as a wide working range up to 17 MPa. These sensors are potential for practical applications such as detecting small stress and movement in civil structures.

  6. Seals and sealing handbook

    CERN Document Server

    Flitney, Robert K

    2014-01-01

    Seals and Sealing Handbook, 6th Edition provides comprehensive coverage of sealing technology, bringing together information on all aspects of this area to enable you to make the right sealing choice. This includes detailed coverage on the seals applicable to static, rotary and reciprocating applications, the best materials to use in your sealing systems, and the legislature and regulations that may impact your sealing choices. Updated in line with current trends this updated reference provides the theory necessary for you to select the most appropriate seals for the job and with its 'Failur

  7. Wrinkles, loops, and topological defects in twisted ribbons

    Science.gov (United States)

    Chopin, Julien

    Nature abounds with elastic ribbon like shapes including double-stranded semiflexible polymers, graphene and metal oxide nanoribbons which are examples of elongated elastic structures with a strongly anisotropic cross-section. Due to this specific geometry, it is far from trivial to anticipate if a ribbon should be considered as a flat flexible filament or a narrow thin plate. We thus perform an experiment in which a thin elastic ribbon is loaded using a twisting and traction device coupled with a micro X-ray computed tomography machine allowing a full 3D shape reconstruction. A wealth of morphological behaviors can be observed including wrinkled helicoids, curled and looped configurations, and faceted ribbons. In this talk, I will show that most morphologies can be understood using a far-from-threshold approach and simple scaling arguments. Further, we find that the various shapes can be organized in a phase diagram using the twist, the tension, and the geometry of the ribbon as control parameters. Finally, I will discuss the spontaneous formation of topological defects with negatively-signed Gaussian charge at large twist and small but finite stretch.

  8. Modeling of inter-ribbon tunneling in graphene

    OpenAIRE

    Van de Put, Maarten L.; Vandenberghe, William G.; Sorée, Bart; Magnus, Wim; Fischetti, Massimo

    2015-01-01

    The tunneling current between two crossed graphene ribbons is described invoking the empirical pseudopotential approximation and the Bardeen transfer Hamiltonian method. Results indicate that the density of states is the most important factor determining the tunneling current between small (nm) ribbons. The quasi-one dimensional nature of graphene nanoribbons is shown to result in resonant tunneling.

  9. Dosimetry of wires and single ribbons of Iridium 192; Dosimetria de alambres y ribbons individuales de Iridio-192

    Energy Technology Data Exchange (ETDEWEB)

    Mazzucco, L.D. [Centro Medico Nuclear S.R.L. San Juan (Argentina)

    1998-12-31

    The objective of this work is in order to present in table formats the dosimetry of wires and single ribbons of Iridium with lengths 1-12 cm for each one linear source along the bisector which is perpendicular at tissue sources (water) computed for linear activity 1 mCi/cm in the case of wires, and 1 mCi/seed for ribbons. The above tables are of direct use, adaptable at particular cases so they facilitate logarithmic graphics of doses in function of the distance for interpolation and use in the treatments planning. It was shown that for two sources with identical linear activity and total length, one of the equidistant seeds at 1 cm (ribbon) and one wire on the other hand, the differences in dose rates in near positions can be about the 15% so corroborating that it is not possible to use wire tables for seeds neither vice versa. Moreover it was elaborated tables of practical direct use for dose rate in water at c Gy/hr for wires and Ribbons 1-12 cm length and from 0.5-10 cm of distance in the perpendicular bisector at the Iridium implant. (Author)

  10. Electronic properties and mechanical strength of β-phosphorene nano-ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Swaroop, Ram; Bhatia, Pradeep; Kumar, Ashok, E-mail: ashok@cup.ac.in [Centre for Physical Sciences, School of Basic and Applied Sciences, Central University of Punjab, Bathinda, India-151001 (India)

    2016-05-06

    We have performed first principles calculations to find out the effect of mechanical strain on the electronic properties of zig-zag edged nano ribbons of β-phosphorene. It is found that electronic band-gap get opened-up to 2.61 eV by passivation of the edges of ribbons. Similarly, the mechanical strength is found to be increase from 1.75 GPa to 2.65 GPa on going from unpassivated nano ribbons to passivated ones along with the 2% increase in ultimate tensile strain. The band-gap value of passivated ribbon gets decreased to 0.43 eV on applying strain up to which the ribbon does not break. These tunable properties of β-phospherene with passivation with H-atom and applying mechanical strain offer its use in tunable nano electronics.

  11. Structure and magnetic properties of Alnico ribbons

    Science.gov (United States)

    Zhang, Ce; Li, Ying; Han, Xu-Hao; Du, Shuai-long; Sun, Ji-bing; Zhang, Ying

    2018-04-01

    Al-Ni-Co alloy has been widely applied in various industrial fields due to its excellent thermal and magnetic stability. In this paper, new Al-Ni-Co ribbons are prepared by simple processes combining melt-spinning with annealing, and their phase transition, microstructure and magnetic properties are studied. The results show that after as-spun ribbons are annealed, the grain size of ribbons increases from 1.1 ± 0.3 μm to 4.8 ± 0.8 μm, but still much smaller than that of the bulk Al-Ni-Co alloy manufactured by traditional technologies. In addition, some rod-like Al70Co20Ni10-type, Al9Co2-type and Fe2Nb-type phases are precipitated at grain boundaries; simultaneously, the distinct spinodal decomposition microstructure with periodic ingredient variation is thoroughly formed in all grains by the reaction of α → α1 + α2. Furthermore, the α1 and α2 distribute alternately like a maze, the Fe-Co-rich α1 phase holds 35.9-47.3 vol%, while the Al-Ni-rich α2 phase occupies the rest. Finally, the coercivity of annealed ribbons can reach to 485.3 ± 76.6 Oe. If the annealed ribbons are further aged at 560 °C, their Hc even increases to 738.1 ± 81.0 Oe. The coercivity mechanism is discussed by the combination of microstructure and domain structure.

  12. Synaptic ribbon. Conveyor belt or safety belt?

    Science.gov (United States)

    Parsons, T D; Sterling, P

    2003-02-06

    The synaptic ribbon in neurons that release transmitter via graded potentials has been considered as a conveyor belt that actively moves vesicles toward their release sites. But evidence has accumulated to the contrary, and it now seems plausible that the ribbon serves instead as a safety belt to tether vesicles stably in mutual contact and thus facilitate multivesicular release by compound exocytosis.

  13. Experimental investigation of the ribbon-array ablation process

    International Nuclear Information System (INIS)

    Li Zhenghong; Xu Rongkun; Chu Yanyun; Yang Jianlun; Xu Zeping; Ye Fan; Chen Faxin; Xue Feibiao; Ning Jiamin; Qin Yi; Meng Shijian; Hu Qingyuan; Si Fenni; Feng Jinghua; Zhang Faqiang; Chen Jinchuan; Li Linbo; Chen Dingyang; Ding Ning; Zhou Xiuwen

    2013-01-01

    Ablation processes of ribbon-array loads, as well as wire-array loads for comparison, were investigated on Qiangguang-1 accelerator. The ultraviolet framing images indicate that the ribbon-array loads have stable passages of currents, which produce axially uniform ablated plasma. The end-on x-ray framing camera observed the azimuthally modulated distribution of the early ablated ribbon-array plasma and the shrink process of the x-ray radiation region. Magnetic probes measured the total and precursor currents of ribbon-array and wire-array loads, and there exists no evident difference between the precursor currents of the two types of loads. The proportion of the precursor current to the total current is 15% to 20%, and the start time of the precursor current is about 25 ns later than that of the total current. The melting time of the load material is about 16 ns, when the inward drift velocity of the ablated plasma is taken to be 1.5 × 10 7 cm/s.

  14. Nanostructure and magnetic properties of Ni-substituted finemet ribbons

    International Nuclear Information System (INIS)

    Iturriza, N.; Fernandez, L.; Ipatov, M.; Vara, G.; Pierna, A.R.; Val, J.J. del; Chizhik, A.; Gonzalez, J.

    2007-01-01

    Magnetic anisotropy has been induced during the nanocrystallization process of Ni-rich amorphous ferromagnetic (Finemet) ribbons by means of the application of a constant stress during the annealing process. Magnetization measurements have evidenced the anisotropy of the treated samples. The main goal of this work was the analysis of the treated ribbons using X-ray Diffraction (XRD), Transmission Electronic Microscopy (TEM) and Atomic Force Microscopy (AFM). AFM measurements revealed in all the cases a strong nanocrystallisation of the surface without evidences of amorphous matrix, which contrast with XRD and TEM measurements that have shown a high content of amorphous phase in the bulk of the ribbons. Magneto-optical Kerr effect measurements show much higher coercive field values than in the bulk, indicating a complex magnetic behavior for the surface of the ribbons

  15. Blue Ribbon Panel Report

    Science.gov (United States)

    An NCI Cancer Currents blog by the NCI acting director thanking the cancer community for contributing to the Cancer Moonshot Blue Ribbon Panel report, which was presented to the National Cancer Advisory Board on September 7.

  16. THE NATURE OF FLARE RIBBONS IN CORONAL NULL-POINT TOPOLOGY

    International Nuclear Information System (INIS)

    Masson, S.; Aulanier, G.; Pariat, E.; Schrijver, C. J.

    2009-01-01

    Flare ribbons are commonly attributed to the low-altitude impact, along the footprints of separatrices or quasi-separatrix layers (QSLs), of particle beams accelerated through magnetic reconnection. If reconnection occurs at a three-dimensional coronal magnetic null point, the footprint of the dome-shaped fan surface would map a closed circular ribbon. This paper addresses the following issues: does the entire circular ribbon brighten simultaneously, as expected because all fan field lines pass through the null point? And since the spine separatrices are singular field lines, do spine-related ribbons look like compact kernels? What can we learn from these observations about current sheet formation and magnetic reconnection in a null-point topology? The present study addresses these questions by analyzing Transition Region and Coronal Explorer and Solar and Heliospheric Observatory/Michelson Doppler Imager observations of a confined flare presenting a circular ribbon. Using a potential field extrapolation, we linked the circular shape of the ribbon with the photospheric mapping of the fan field lines originating from a coronal null point. Observations show that the flare ribbon outlining the fan lines brightens sequentially along the counterclockwise direction and that the spine-related ribbons are elongated. Using the potential field extrapolation as initial condition, we conduct a low-β resistive magnetohydrodynamics simulation of this observed event. We drive the coronal evolution by line-tied diverging boundary motions, so as to emulate the observed photospheric flow pattern associated with some magnetic flux emergence. The numerical analysis allows us to explain several observed features of the confined flare. The vorticity induced in the fan by the prescribed motions causes the spines to tear apart along the fan. This leads to formation of a thin current sheet and induces null-point reconnection. We also find that the null point and its associated topological

  17. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...

  18. Generation Mechanisms of Quasi-parallel and Quasi-circular Flare Ribbons in a Confined Flare

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Perez, Aaron; Thalmann, Julia K.; Veronig, Astrid M.; Dickson, Ewan C. [IGAM/Institute of Physics, University of Graz, A-8010 Graz (Austria); Su, Yang [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory Chinese Academy of Sciences, 2 West Beijing Road, 210008 Nanjing (China); Gömöry, Peter, E-mail: aaron.hernandez-perez@uni-graz.at [Astronomical Institute, Slovak Academy of Sciences, 05960 Tatranská Lomnica (Slovakia)

    2017-10-01

    We analyze a confined multiple-ribbon M2.1 flare (SOL2015-01-29T11:42) that originated from a fan-spine coronal magnetic field configuration, within active region NOAA 12268. The observed ribbons form in two steps. First, two primary ribbons form at the main flare site, followed by the formation of secondary ribbons at remote locations. We observe a number of plasma flows at extreme-ultraviolet temperatures during the early phase of the flare (as early as 15 minutes before the onset) propagating toward the formation site of the secondary ribbons. The secondary ribbon formation is co-temporal with the arrival of the pre-flare generated plasma flows. The primary ribbons are co-spatial with Ramaty High Energy Spectroscopic Imager ( RHESSI ) hard X-ray sources, whereas no enhanced X-ray emission is detected at the secondary ribbon sites. The (E)UV emission, associated with the secondary ribbons, peaks ∼1 minute after the last RHESSI hard X-ray enhancement. A nonlinear force-free model of the coronal magnetic field reveals that the secondary flare ribbons are not directly connected to the primary ribbons, but to regions nearby. Detailed analysis suggests that the secondary brightenings are produced due to dissipation of kinetic energy of the plasma flows (heating due to compression), and not due to non-thermal particles accelerated by magnetic reconnection, as is the case for the primary ribbons.

  19. Plastic deformation of silicon dendritic web ribbons during the growth

    Science.gov (United States)

    Cheng, L. J.; Dumas, K. A.; Su, B. M.; Leipold, M. H.

    1984-01-01

    The distribution of slip dislocations in silicon dendritic web ribbons due to plastic deformation during the cooling phase of the growth was studied. The results show the existence of two distinguishable stress regions across the ribbon formed during the plastic deformation stage, namely, shear stress at the ribbon edges and tensile stress at the middle. In addition, slip dislocations caused by shear stress near the edges appear to originate at the twin plane.

  20. Flare Ribbons Approach Observed by the Interface Region Imaging Spectrograph and the Solar Dynamics Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ting; Zhang, Jun; Hou, Yijun, E-mail: liting@nao.cas.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2017-10-10

    We report flare ribbons approach (FRA) during a multiple-ribbon M-class flare on 2015 November 4 in NOAA AR 12443, obtained by the Interface Region Imaging Spectrograph and the Solar Dynamics Observatory. The flare consisted of a pair of main ribbons and two pairs of secondary ribbons. The two pairs of secondary ribbons were formed later than the appearance of the main ribbons, with respective time delays of 15 and 19 minutes. The negative-polarity main ribbon spread outward faster than the first secondary ribbon with the same polarity in front of it, and thus the FRA was generated. Just before their encounter, the main ribbon was darkening drastically and its intensity decreased by about 70% in 2 minutes, implying the suppression of main-phase reconnection that produced two main ribbons. The FRA caused the deflection of the main ribbon to the direction of secondary ribbon with a deflection angle of about 60°. A post-approach arcade was formed about 2 minutes later and the downflows were detected along the new arcade with velocities of 35–40 km s{sup −1}, indicative of the magnetic restructuring during the process of FRA. We suggest that there are three topological domains with footpoints outlined by the three pairs of ribbons. Close proximity of these domains leads to deflection of the ribbons, which is in agreement with the magnetic field topology.

  1. Inter-ribbon tunneling in graphene: An atomistic Bardeen approach

    Energy Technology Data Exchange (ETDEWEB)

    Van de Put, Maarten L., E-mail: maarten.vandeput@uantwerpen.be; Magnus, Wim [Department of Physics, Universiteit Antwerpen, B-2020 Antwerpen (Belgium); imec, B-3001 Heverlee (Belgium); Vandenberghe, William G.; Fischetti, Massimo V. [Department of Material Science, University of Texas at Dallas, Texas 75080 (United States); Sorée, Bart [Department of Physics, Universiteit Antwerpen, B-2020 Antwerpen (Belgium); imec, B-3001 Heverlee (Belgium); Department of Electrical Engineering, KU Leuven, B-3001 Leuven (Belgium)

    2016-06-07

    A weakly coupled system of two crossed graphene nanoribbons exhibits direct tunneling due to the overlap of the wavefunctions of both ribbons. We apply the Bardeen transfer Hamiltonian formalism, using atomistic band structure calculations to account for the effect of the atomic structure on the tunneling process. The strong quantum-size confinement of the nanoribbons is mirrored by the one-dimensional character of the electronic structure, resulting in properties that differ significantly from the case of inter-layer tunneling, where tunneling occurs between bulk two-dimensional graphene sheets. The current-voltage characteristics of the inter-ribbon tunneling structures exhibit resonance, as well as stepwise increases in current. Both features are caused by the energetic alignment of one-dimensional peaks in the density-of-states of the ribbons. Resonant tunneling occurs if the sign of the curvature of the coupled energy bands is equal, whereas a step-like increase in the current occurs if the signs are opposite. Changing the doping modulates the onset-voltage of the effects as well as their magnitude. Doping through electrostatic gating makes these structures promising for application towards steep slope switching devices. Using the atomistic empirical pseudopotentials based Bardeen transfer Hamiltonian method, inter-ribbon tunneling can be studied for the whole range of two-dimensional materials, such as transition metal dichalcogenides. The effects of resonance and of step-like increases in the current we observe in graphene ribbons are also expected in ribbons made from these alternative two-dimensional materials, because these effects are manifestations of the one-dimensional character of the density-of-states.

  2. After the Ribbon Cutting

    DEFF Research Database (Denmark)

    Hodge, Graeme A.; Boulot, Emille; Duffield, Colin

    2017-01-01

    Much attention has gone towards ‘up-front’ processes when delivering infrastructure public–private partnerships (PPPs), but less on how to best govern after the ribbon is cut and the infrastructure built. This paper identifies the primary contractual and institutional governance challenges arising...

  3. Position of the IBEX ribbon as a key to understand its origin

    Science.gov (United States)

    Swaczyna, Pawel; Bzowski, Maciej; Sokół, Justyna M.; Christian, Eric R.; Funsten, Herbert O.; McComas, David J.; Schwadron, Nathan A.

    2017-04-01

    Observations of the energetic neutral atom (ENA) emission by the Interstellar Boundary Explorer (IBEX) allow for remote sensing of the plasma properties in heliosheath. The first IBEX results revealed an unexpected arc-like enhancement of the ENA flux in the sky, dubbed the IBEX ribbon. This discovery led to formulation of more than a dozen hypotheses on its origin. The emission source region proposed in these hypotheses span the heliospheric termination shock up to a hypothetical nearby interface between the Local Interstellar Cloud and a local bay in the Local Bubble. Among these hypotheses is the concept that the ribbon is produced by the secondary ENA mechanism, operating in the outer heliosheath. The observational strategy of IBEX allows observation of the same part of the sky from the opposite sides of the Sun every six months and thus provides parallax viewing with a baseline of 2 AU. After correcting the observations for the Compton-Getting effect and for gravitational deflection and radiation pressure, we use this parallax viewing to precisely determine the apparent position of the maximum flux associated with the ribbon. We find that the ribbon peak position differs semi-annually by an angle of 0.41±0.15 deg, which we interpret as the parallax effect. This angle corresponds to a distance of 140-38+84 AU, and thus suggests that most likely the ribbon's source is located just beyond the heliopause. Comparison of the IBEX ribbon position in five energy steps of IBEX-Hi shows a systematic shift, which changes the position of the ribbon center by ˜10 deg. We find that it can be explained using an analytic model of the secondary ENA mechanism with the neutralized supersonic solar wind as the source of the primary ENAs, which are ionized in the outer heliosheath, picked up by the ambient magnetic field, and eventually re-neutralized (as originally conceived, McComas et al. 2009). We use a realistic model of the solar wind evolution dependent on heliographic

  4. Mena–GRASP65 interaction couples actin polymerization to Golgi ribbon linking

    Science.gov (United States)

    Tang, Danming; Zhang, Xiaoyan; Huang, Shijiao; Yuan, Hebao; Li, Jie; Wang, Yanzhuang

    2016-01-01

    In mammalian cells, the Golgi reassembly stacking protein 65 (GRASP65) has been implicated in both Golgi stacking and ribbon linking by forming trans-oligomers through the N-terminal GRASP domain. Because the GRASP domain is globular and relatively small, but the gaps between stacks are large and heterogeneous, it remains puzzling how GRASP65 physically links Golgi stacks into a ribbon. To explore the possibility that other proteins may help GRASP65 in ribbon linking, we used biochemical methods and identified the actin elongation factor Mena as a novel GRASP65-binding protein. Mena is recruited onto the Golgi membranes through interaction with GRASP65. Depleting Mena or disrupting actin polymerization resulted in Golgi fragmentation. In cells, Mena and actin were required for Golgi ribbon formation after nocodazole washout; in vitro, Mena and microfilaments enhanced GRASP65 oligomerization and Golgi membrane fusion. Thus Mena interacts with GRASP65 to promote local actin polymerization, which facilitates Golgi ribbon linking. PMID:26538023

  5. The status of silicon ribbon growth technology for high-efficiency silicon solar cells

    Science.gov (United States)

    Ciszek, T. F.

    1985-01-01

    More than a dozen methods have been applied to the growth of silicon ribbons, beginning as early as 1963. The ribbon geometry has been particularly intriguing for photovoltaic applications, because it might provide large area, damage free, nearly continuous substrates without the material loss or cost of ingot wafering. In general, the efficiency of silicon ribbon solar cells has been lower than that of ingot cells. The status of some ribbon growth techniques that have achieved laboratory efficiencies greater than 13.5% are reviewed, i.e., edge-defined, film-fed growth (EFG), edge-supported pulling (ESP), ribbon against a drop (RAD), and dendritic web growth (web).

  6. Scintillating ribbon x-ray detector

    International Nuclear Information System (INIS)

    Kinchen, B.E.; Rogers, A.

    1995-01-01

    A patent in the early 1970's by Aerojet Corporation in Sacramento, CA put forth the idea of using an array of scintillating fibers for x-ray detection and imaging. In about 1975, Pratt and Whitney Aircraft in East Hartford, CT designed and manufactured an imaging system based on the patent. The device was 1.75 in thick in the direction of the x-ray beam and about 4 in. by 4 in. square. The device was used with a 8 MeV x-ray source to image and measure internal clearances within operating aircraft, gas turbines engines. There are significant advantages of fiber optic detectors in x-ray detection. However, the advantages are often outweighed by the disadvantages. Two of the advantages of scintillating fiber optic x-ray detectors are: (1) high limiting spatial frequency -- between 20 and 25 lp/mm; and (2) excellent x-ray stopping power -- they can be made thick and retain spatial resolution. In traditional fiber optic detectors the x-rays are oriented parallel to the long axis of the fiber. For the scintillating ribbon x-ray sensor, the x-rays are oriented normal to the fiber long axis. This ribbon sensor technique has a number of advantages over the two current radiographic techniques digital x-radiography and x-ray film: The main advantage the ribbon has is size and shape. It can be as thin as 0.05 in., virtually any width or length, and flexible. Once positioned in a given location, 20 to 100 square inches of the object being inspected can be imaged with a single x-ray beam sweep. It is clear that conventional digital cameras do not lend themselves to placement between walls of aircraft structures or similar items requiring x-ray inspections. A prototype scintillating ribbon x-ray sensor has been fabricated and tested by Synergistic Detector Designs. Images were acquired on corrosion test panels of aluminum fabricated by Iowa State University

  7. Electronic, magnetic and transport properties of graphene ribbons terminated by nanotubes

    International Nuclear Information System (INIS)

    Akhukov, M A; Yuan Shengjun; Fasolino, A; Katsnelson, M I

    2012-01-01

    We study, by density functional and large-scale tight-binding transport calculations, the electronic structure, magnetism and transport properties of the recently proposed graphene ribbons with edges rolled to form nanotubes. Edges with armchair nanotubes present magnetic moments localized either in the tube or the ribbon and of metallic or half-metallic character, depending on the symmetry of the junction. These properties have potential for spin valve and spin filter devices with advantages over other proposed systems. Edges with zigzag nanotubes are either metallic or semiconducting without affecting the intrinsic mobility of the ribbon. Varying the type and size of the nanotubes and ribbons offers the possibility to tailor the magnetic and transport properties, making these systems very promising for applications. (paper)

  8. A MAGNETIC RIBBON MODEL FOR STAR-FORMING FILAMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Auddy, Sayantan; Basu, Shantanu [Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7 (Canada); Kudoh, Takahiro, E-mail: sauddy3@uwo.ca, E-mail: basu@uwo.ca, E-mail: kudoh@nagasaki-u.ac.jp [Faculty of Education, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521 (Japan)

    2016-11-01

    We develop a magnetic ribbon model for molecular cloud filaments. These result from turbulent compression in a molecular cloud in which the background magnetic field sets a preferred direction. We argue that this is a natural model for filaments and is based on the interplay between turbulence, strong magnetic fields, and gravitationally driven ambipolar diffusion, rather than pure gravity and thermal pressure. An analytic model for the formation of magnetic ribbons that is based on numerical simulations is used to derive a lateral width of a magnetic ribbon. This differs from the thickness along the magnetic field direction, which is essentially the Jeans scale. We use our model to calculate a synthetic observed relation between apparent width in projection versus observed column density. The relationship is relatively flat, similar to observations, and unlike the simple expectation based on a Jeans length argument.

  9. Development of a magnetic measurement device for thin ribbon samples

    International Nuclear Information System (INIS)

    Sato, Yuta; Todaka, Takashi; Enokizono, Masato

    2008-01-01

    This paper presents a magnetic measurement device for thin ribbon samples, which are produced by rapid cooling technique. This device enables us to measure magnetic properties easily by only inserting a ribbon sample into a sample holder. The sample holder was made by bakelite to fix any width sample. A long solenoid coil was used to generate a uniform magnetic field and the sample holder was placed at the mid part of the solenoid. The magnetic field strength was measured using a shunt resistor and the magnetic flux density and magnetization in sample ribbons were evaluated by using search coils. The accuracy of measurement was verified with an amorphous metal ribbon sample. Next, we have measured magnetic properties of some magnetic shape memory alloys, which have different compositions. The measured results are compared and we clarified the effect of Sm contents on the magnetic properties

  10. FLARE RIBBON ENERGETICS IN THE EARLY PHASE OF AN SDO FLARE

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, L.; Hannah, I. G.; Hudson, H. S. [School of Physics and Astronomy, SUPA, University of Glasgow, Glasgow, G12 8QQ (United Kingdom); Innes, D. E. [Max Planck Institute for Solar System Research, Max-Planck-Strasse 2, D-37191 Katlenburg-Lindau (Germany)

    2013-07-10

    The sites of chromospheric excitation during solar flares are marked by extended extreme ultraviolet ribbons and hard X-ray (HXR) footpoints. The standard interpretation is that these are the result of heating and bremsstrahlung emission from non-thermal electrons precipitating from the corona. We examine this picture using multi-wavelength observations of the early phase of an M-class flare SOL2010-08-07T18:24. We aim to determine the properties of the heated plasma in the flare ribbons, and to understand the partition of the power input into radiative and conductive losses. Using GOES, SDO/EVE, SDO/AIA, and RHESSI, we measure the temperature, emission measure (EM), and differential emission measure of the flare ribbons, and deduce approximate density values. The non-thermal EM, and the collisional thick target energy input to the ribbons are obtained from RHESSI using standard methods. We deduce the existence of a substantial amount of plasma at 10 MK in the flare ribbons, during the pre-impulsive and early-impulsive phase of the flare. The average column EM of this hot component is a few times 10{sup 28} cm{sup -5}, and we can calculate that its predicted conductive losses dominate its measured radiative losses. If the power input to the hot ribbon plasma is due to collisional energy deposition by an electron beam from the corona then a low-energy cutoff of {approx}5 keV is necessary to balance the conductive losses, implying a very large electron energy content. Independent of the standard collisional thick-target electron beam interpretation, the observed non-thermal X-rays can be provided if one electron in 10{sup 3}-10{sup 4} in the 10 MK (1 keV) ribbon plasma has an energy above 10 keV. We speculate that this could arise if a non-thermal tail is generated in the ribbon plasma which is being heated by other means, for example, by waves or turbulence.

  11. GMI effect in CuO coated Co-based amorphous ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Taysioglu, Asli Ayten [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Peksoz, Ahmet, E-mail: peksoz@uludag.edu.t [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Kaya, Yunus [Department of Chemistry, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Derebasi, Naim [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Irez, Gazi [Department of Chemistry, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Kaynak, Gokay [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey)

    2009-11-13

    A Copper oxide (CuO) film has been grown on a surface of Co-based amorphous ribbon using chemical successive ionic layer adsorption and reaction technique, at room temperature and atmosphere pressure. The influence of coating and width of ribbon on giant magneto impedance have been investigated over a frequency range from 0.1 to 3 MHz and under a static magnetic field between -8 and +8 kA/m. The results showed that Co-based amorphous ribbons, which are coated CuO film, have a significant effect on the magnitude and operation frequency for the giant magneto impedance effect as compared to the samples without coating. The highest giant magneto impedance effect was found to be 14.90 on 5 mm width coated ribbon, which is 60% higher than the sample without coating. A surface observation of these samples has been carried out by an atomic force microscope. The AFM images reveal the difference between surfaces of coated and as-cast sample.

  12. GMI effect in CuO coated Co-based amorphous ribbons

    International Nuclear Information System (INIS)

    Taysioglu, Asli Ayten; Peksoz, Ahmet; Kaya, Yunus; Derebasi, Naim; Irez, Gazi; Kaynak, Gokay

    2009-01-01

    A Copper oxide (CuO) film has been grown on a surface of Co-based amorphous ribbon using chemical successive ionic layer adsorption and reaction technique, at room temperature and atmosphere pressure. The influence of coating and width of ribbon on giant magneto impedance have been investigated over a frequency range from 0.1 to 3 MHz and under a static magnetic field between -8 and +8 kA/m. The results showed that Co-based amorphous ribbons, which are coated CuO film, have a significant effect on the magnitude and operation frequency for the giant magneto impedance effect as compared to the samples without coating. The highest giant magneto impedance effect was found to be 14.90 on 5 mm width coated ribbon, which is 60% higher than the sample without coating. A surface observation of these samples has been carried out by an atomic force microscope. The AFM images reveal the difference between surfaces of coated and as-cast sample.

  13. Seals and sealing handbook

    CERN Document Server

    Flitney, Robert K

    2007-01-01

    Wherever machinery operates there will be seals of some kind ensuring that the machine remains lubricated, the fluid being pumped does not leak, or the gas does not enter the atmosphere. Seals are ubiquitous, in industry, the home, transport and many other places. This 5th edition of a long-established title covers all types of seal by application: static, rotary, reciprocating etc. The book bears little resemblance to its predecessors, and Robert Flitney has re-planned and re-written every aspect of the subject. No engineer, designer or manufacturer of seals can afford to be without this uniq

  14. Dosimetry of wires and single ribbons of Iridium 192

    International Nuclear Information System (INIS)

    Mazzucco, L.D.

    1998-01-01

    The objective of this work is in order to present in table formats the dosimetry of wires and single ribbons of Iridium with lengths 1-12 cm for each one linear source along the bisector which is perpendicular at tissue sources (water) computed for linear activity 1 mCi/cm in the case of wires, and 1 mCi/seed for ribbons. The above tables are of direct use, adaptable at particular cases so they facilitate logarithmic graphics of doses in function of the distance for interpolation and use in the treatments planning. It was shown that for two sources with identical linear activity and total length, one of the equidistant seeds at 1 cm (ribbon) and one wire on the other hand, the differences in dose rates in near positions can be about the 15% so corroborating that it is not possible to use wire tables for seeds neither vice versa. Moreover it was elaborated tables of practical direct use for dose rate in water at c Gy/hr for wires and Ribbons 1-12 cm length and from 0.5-10 cm of distance in the perpendicular bisector at the Iridium implant. (Author)

  15. Nanocrystallization in amorphous Fe40Ni40(Si+B)19Mo1-2 ribbons

    International Nuclear Information System (INIS)

    Saiseng, S.; Winotai, P.; Nilpairuch, S.; Limsuwan, P.; Tang, I.M.

    2004-01-01

    Cut Fe 40 Ni 40 (Si+B) 19 Mo 1-2 ribbons were annealed for 2 h at various temperatures between 350 deg. C and 600 deg. C. XRD and Mossbauer effect spectroscopy (ME) measurements were then performed on all of the ribbons. The magnetic properties of several ribbons were measured using a vibrating sample magnetometer (VSM). A differential thermal analysis scan (over the range 20-800 deg. C) of the as-cast ribbon showed two phase transitions; the first at 454 deg. C and the second at 525 deg. C. Both the XRD and ME spectra of the as cast, the 350 deg. C and 400 deg. C annealed ribbons showed that they were amorphous. The ME spectra of the 450 deg. C, 475 deg. C and 500 deg. C annealed ribbons showed that these ribbons contained α-Fe, α-Fe(Si) and t-Fe 2 B nanocrystallites. For the ribbons annealed above 550 deg. C, crystallites of t-Fe 2 B, t-Fe 3 B, t-Fe 5 SiB 2 and FCC-FeNi appeared, with the α-Fe and α-Fe(Si) crystallites disappearing. The sextets of all of the Fe compounds appeared in the ME spectra of the 525 deg. C annealed ribbon. The VSM measurements supported the picture of a two-stage phase transitions; amorphous phase→a nanocrystalline phase (Fe-containing nanocrystallites in an amorphous matrix) at 454 deg. C and then a second transition, the nanocrystalline phase→a disordered alloy containing Fe-B and Fe-Ni crystallites at 525 deg. C

  16. Metallurgical characterization of melt-spun ribbons of U-5.4 wt%Nb alloy

    Science.gov (United States)

    Ma, Rong; Ren, Zhiyong; Tang, Qingfu; Chen, Dong; Liu, Tingyi; Su, Bin; Wang, Zhenhong; Luo, Chao

    2018-06-01

    The microstructures and micro-mechanical properties of the melt-spun ribbons of U-5.4 wt%Nb alloy were characterized using optical microscopy, scanning electron microscopy, X-ray diffraction and nanoindentation. Observed variations in microstructures and properties are related to the changes in ribbon thicknesses and cooling rates. The microstructures of the melt-spun ribbon consist of fine-scale columnar grains (∼1 μm) adjacent to the chill surface and coarse cellular grains in the remainder of the ribbon. In addition, the formation of inclusions in the ribbon is suppressed kinetically due to the high cooling rate during melt spinning. Compared with the water-quenched specimen prepared by traditional gravity casting and solution heat treatment, the elastic modulus values of the U-5.4 wt%Nb alloy were examined to vary with grain size and exhibited diverse energy dissipation capacities.

  17. The ribbon microphone: A teaching aid for low frequency electromagnetic education

    CSIR Research Space (South Africa)

    Van Wyk, Marius S

    2017-09-01

    Full Text Available The ribbon microphone lends itself as a good example to use for education of multi-physics computer modeling and simulation. The value of the ribbon microphone as teaching aid can be extended by adding a transformer and electronic amplifier...

  18. Domain walls dynamics in the amorphous ribbon with a helical magnetic anisotropy

    International Nuclear Information System (INIS)

    Zhmetko, D.N.; Savin, V.V.; Lemish, P.V.; Troschenkov, Y.N.

    2006-01-01

    The damping mechanism for motion of domain walls, which form the sandwich structure and move from the middle plane of the ribbon to opposite surfaces during the dynamic magnetization reversal, have been investigated. The difference between the real and ideal sandwich domain structure, the actual distribution of the anisotropy easy directions through the ribbon thickness and the M-bar s deviation from local easy directions under the action of applied magnetic field have been taken into account. It was revealed that the maximum of the total damping coefficient β tot (x) near the half-way of the domain wall run is due to the influence of the magnetic stray fields. These fields have a character of irregular oscillations and are directed approximately perpendicular to the local easy direction of the ribbon layer through which the domain wall propagates. The damping coefficient β e.c. (x) determined by eddy-currents has the maximal value close to the ribbon middle and decreases linearly to zero when the domain wall approaches the ribbon surface

  19. Magnetoimpedance of cobalt-based amorphous ribbons/polymer composites

    Energy Technology Data Exchange (ETDEWEB)

    Semirov, A.V., E-mail: semirov@mail.ru [Irkutsk State University, Irkutsk (Russian Federation); Derevyanko, M.S.; Bukreev, D.A.; Moiseev, A.A.; Kudryavtsev, V.O. [Irkutsk State University, Irkutsk (Russian Federation); Safronov, A.P. [Ural Federal University, Yekaterinburg (Russian Federation)

    2016-10-01

    The combined influence of the temperature, the elastic tensile stress and the external magnetic field on the total impedance and impedance components were studied for rapidly quenched amorphous Co{sub 75}Fe{sub 5}Si{sub 4}B{sub 16} ribbons. Both as-cast amorphous ribbons and Co{sub 75}Fe{sub 5}Si{sub 4}B{sub 16}/polymer amorphous ribbon based composites were considered. Following polymer coverings were studied: modified rubber solution in o-xylene, solution of butyl methacrylate and methacrylic acid copolymer in isopropanol and solution of polymethylphenylsiloxane resin in toluene. All selected composites showed very good adhesion of the coverings and allowed to provide temperature measurements from 163 K up to 383 K under the applied deforming tensile force up to 30 N. The dependence of the modulus of the impedance and its components on the external magnetic field was influenced by the elastic tensile stresses and was affected by the temperature of the samples. It was shown that maximal sensitivity of the impedance and its components to the external magnetic field was observed at minimal temperature and maximal deforming force depended on the frequency of an alternating current. - Highlights: • Impedance and its components of amorphous Co{sub 75}Fe{sub 5}Si{sub 4}B{sub 16} ribbons were studied. • MI sensitivity to the magnetic field depends on a temperature and a deforming force. • Polymer covering can affect the functional properties of the composite.

  20. OBSERVATIONS OF AN X-SHAPED RIBBON FLARE IN THE SUN AND ITS THREE-DIMENSIONAL MAGNETIC RECONNECTION

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.; Ding, M. D.; Yang, K. [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Qiu, J.; Longcope, D. W., E-mail: yingli@nju.edu.cn [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

    2016-05-20

    We report evolution of an atypical X-shaped flare ribbon that provides novel observational evidence of three-dimensional (3D) magnetic reconnection at a separator. The flare occurred on 2014 November 9. High-resolution slit-jaw 1330 Å images from the Interface Region Imaging Spectrograph reveal four chromospheric flare ribbons that converge and form an X-shape. Flare brightening in the upper chromosphere spreads along the ribbons toward the center of the “X” (the X-point), and then spreads outward in a direction more perpendicular to the ribbons. These four ribbons are located in a quadrupolar magnetic field. Reconstruction of magnetic topology in the active region suggests the presence of a separator connecting to the X-point outlined by the ribbons. The inward motion of flare ribbons in the early stage therefore indicates 3D magnetic reconnection between two sets of non-coplanar loops that approach laterally, and reconnection proceeds downward along a section of vertical current sheet. Coronal loops are also observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory confirming the reconnection morphology illustrated by ribbon evolution.

  1. Mena-GRASP65 interaction couples actin polymerization to Golgi ribbon linking.

    Science.gov (United States)

    Tang, Danming; Zhang, Xiaoyan; Huang, Shijiao; Yuan, Hebao; Li, Jie; Wang, Yanzhuang

    2016-01-01

    In mammalian cells, the Golgi reassembly stacking protein 65 (GRASP65) has been implicated in both Golgi stacking and ribbon linking by forming trans-oligomers through the N-terminal GRASP domain. Because the GRASP domain is globular and relatively small, but the gaps between stacks are large and heterogeneous, it remains puzzling how GRASP65 physically links Golgi stacks into a ribbon. To explore the possibility that other proteins may help GRASP65 in ribbon linking, we used biochemical methods and identified the actin elongation factor Mena as a novel GRASP65-binding protein. Mena is recruited onto the Golgi membranes through interaction with GRASP65. Depleting Mena or disrupting actin polymerization resulted in Golgi fragmentation. In cells, Mena and actin were required for Golgi ribbon formation after nocodazole washout; in vitro, Mena and microfilaments enhanced GRASP65 oligomerization and Golgi membrane fusion. Thus Mena interacts with GRASP65 to promote local actin polymerization, which facilitates Golgi ribbon linking. © 2016 Tang et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  2. Dynamics of sandwich domain structure in Co-based amorphous ribbons with helical magnetic anisotropy: Part I

    International Nuclear Information System (INIS)

    Zhmetko, D.N.; Zhmetko, S.D.

    2009-01-01

    The distribution of axes of easy magnetization close to a homogeneous distribution is revealed in each half-thickness of a ribbon after annealing it in a helical magnetic field. The transition from magnetic reversal of a ribbon by the displacement of two domain walls formed near a middle plane of a ribbon to magnetic reversal of a ribbon by displacement of two domain walls formed near to the main surfaces of a ribbon is found out during each half-period of a magnetic reversal.

  3. Temperature distribution study in flash-annealed amorphous ribbons

    International Nuclear Information System (INIS)

    Moron, C.; Garcia, A.; Carracedo, M.T.

    2003-01-01

    Negative magnetrostrictive amorphous ribbons have been locally current annealed with currents from 1 to 8 A and annealing times from 14 ms to 200 s. In order to obtain information about the sample temperature during flash or current annealing, a study of the temperature dispersion during annealing in amorphous ribbons was made. The local temperature variation was obtained by measuring the local intensity of the infrared emission of the sample with a CCD liquid nitrogen cooled camera. A distribution of local temperature has been found in spite of the small dimension of the sample

  4. Pressure Actuated Leaf Seals for Improved Turbine Shaft Sealing

    Science.gov (United States)

    Grondahl, Clayton

    2006-01-01

    This presentation introduces a shaft seal in which leaf seal elements are constructed from slotted shim material formed and layered into a frusto-conical assembly. Limited elastic deflection of seal leaves with increasing system pressure close large startup clearance to a small, non-contacting, steady state running clearance. At shutdown seal elements resiliently retract as differential seal pressure diminishes. Large seal clearance during startup and shutdown provides a mechanism for rub avoidance. Minimum operating clearance improves performance and non-contacting operation promises long seal life. Design features of this seal, sample calculations at differential pressures up to 2400 psid and benefit comparison with brush and labyrinth seals is documented in paper, AIAA 2005 3985, presented at the Advanced Seal Technology session of the Joint Propulsion Conference in Tucson this past July. In this presentation use of bimetallic leaf material will be discussed. Frictional heating of bimetallic leaf seals during a seal rub can relieve the rub condition to some extent with a change in seal shape. Improved leaf seal rub tolerance is expected with bimetallic material.

  5. A micromagnetic study of the oscillations of pinned domain walls in magnetic ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Alejos, Oscar [Dpto. Electricidad y Electronica, Universidad de Valladolid, 47071 Valladolid (Spain)]. E-mail: oscaral@ee.uva.es; Torres, Carlos [Dpto. Electricidad y Electronica, Universidad de Valladolid, 47071 Valladolid (Spain); Hernandez-Gomez, Pablo [Dpto. Electricidad y Electronica, Universidad de Valladolid, 47071 Valladolid (Spain); Lopez-Diaz, Luis [Dpto. Fisica Aplicada, Universidad de Salamanca, 37071 Salamanca (Spain); Torres, Luis [Dpto. Fisica Aplicada, Universidad de Salamanca, 37071 Salamanca (Spain); Martinez, Eduardo [Dpto. Ingenieria Electromecanica, Universidad de Burgos, 09001 Burgos (Spain)

    2007-09-15

    The work studies the dynamics of domain walls in magnetic ribbons with thicknesses of the order of magnitude of the permalloy exchange length (5.7 nm) by means of micromagnetic simulations. Two small defects are symmetrically placed on both edges of the ribbon, one on each edge, occupying the whole ribbon thickness. One transverse domain wall is pinned by the defects, in a head-to-head configuration. A free wall oscillation is forced by applying a static external magnetic field in the direction of the large axis until the wall reaches a new equilibrium position (elongation), and then removed. Three dynamic regimes are observed depending on the size of the cross ribbon section.

  6. A micromagnetic study of the oscillations of pinned domain walls in magnetic ribbons

    International Nuclear Information System (INIS)

    Alejos, Oscar; Torres, Carlos; Hernandez-Gomez, Pablo; Lopez-Diaz, Luis; Torres, Luis; Martinez, Eduardo

    2007-01-01

    The work studies the dynamics of domain walls in magnetic ribbons with thicknesses of the order of magnitude of the permalloy exchange length (5.7 nm) by means of micromagnetic simulations. Two small defects are symmetrically placed on both edges of the ribbon, one on each edge, occupying the whole ribbon thickness. One transverse domain wall is pinned by the defects, in a head-to-head configuration. A free wall oscillation is forced by applying a static external magnetic field in the direction of the large axis until the wall reaches a new equilibrium position (elongation), and then removed. Three dynamic regimes are observed depending on the size of the cross ribbon section

  7. Application Potential of Nanocrystalline Ribbons Still Pending

    Science.gov (United States)

    Butvin, Pavol; Butvinová, Beata; Švec, Peter; Sitek, Jozef

    2010-09-01

    Nanocrystalline soft-magnetic ribbons promised a wide-spread practical use when introduced at the beginning of nineties. After 20 years of extensive research there are still unclear material problems which are thought to be the principal reason why these materials show but marginal use. Poorly controllable magnetic anisotropy due to spontaneous intrinsic macroscopic stress that comes from an inevitable heterogeneity of the ribbon materials is pointed to in this work. Certain stress-based mechanisms are shown to induce the unintended anisotropy in the already familiar Finemets as well as in the newer Hitperms. Hysteresis loops, domain structure and power loss is used to reveal the anisotropy consequences and particular connected but still unanswered questions are pinpointed.

  8. Magnetic properties of nanocrystallized Fe-Pt-B melt-spun ribbons

    International Nuclear Information System (INIS)

    Yamamoto, Tokujiro; Omori, Akihiro; Kimura, Hisamichi; Inoue, Akihisa

    2007-01-01

    L1 0 FePt nanoparticles have been prepared by etching grain boundaries of heat-treated melt-spun Fe-19Pt-25B (at.%) alloy ribbons. It is revealed that an L1 0 FePt nanocrystalline phase is directly formed from the Fe-Pt-B amorphous ribbons by long-time heat treatment at low temperatures in the vicinity of 723 K. With increasing heat treatment time, dimensions of the nanocrystallized FePt grains increase, accompanied by a change from soft ferromagnetic to hard ferromagnetic. The ribbon crystallized at 723 K for 1.8 ks consists of only an FePt L1 0 phase and its coercivity is as low as 0.381 kA/m. However, it increases to 372 kA/m with increasing grain size of precipitated L1 0 phase to about 30 nm by heat treatment for 86.4 ks, while the saturation magnetic flux density remains constant at about 0.4 T. Etching boundaries in heat-treated ribbons has been performed to obtain ferromagnetic L1 0 FePt nanoparticles and several particles were observed by means of transmission electron microscopy

  9. Mechanical properties of metallic ribbons investigated by depth sensing indentation technique

    International Nuclear Information System (INIS)

    Pesek, Ladislav; Dobrzanski, Leszek A.; Zubko, Pavol; Konieczny, Jaroslaw

    2006-01-01

    The paper presents mechanical properties of two kinds of Co-based and one Fe-based metallic ribbons by the depth sensing indentation (DSI) technique. Investigations were carried out on two kinds ternary alloy Co 77 Si 11,5 B 11,5 and Fe 78 Si 13 B 9 and multicomponent Co 68 Fe 4 Mo 1 Si 13,5 B 13,5 , which are so-called 'zero-magnetostriction' materials. Metallic ribbons were investigated in amorphous state and partially crystallized state after annealing in 400deg. C in argon atmosphere. Heating of ribbons obtained by melt spinning technique was performed to check its effect on changes of mechanical properties

  10. Oxygen measurements in thin ribbon silicon

    Energy Technology Data Exchange (ETDEWEB)

    Hyland, S L; Ast, D G; Baghdadi, A

    1987-03-01

    The oxygen content of thin silicon ribbons grown by the dendritic web technique was measured using a modification of the ASTM method based on Fourier transform infrared spectroscopy. Web silicon was found to have a high oxygen content, ranging from 13 to 19 ppma, calculated from the absorption peak associated with interstitial oxygen and using the new ASTM conversion coefficient. The oxygen concentration changed by about 10% along the growth direction of the ribbon. In some samples, a shoulder was detected on the absorption peak. A similar shoulder in Czochralski grown material has been variously interpreted in the literature as due to a complex of silicon, oxygen, and vacancies, or to a phase of SiO/sub 2/ developed along dislocations in the material. In the case of web silicon, it is not clear which is the correct interpretation.

  11. Fabrication of Fe-6.5wt%Si Ribbons by Melt Spinning Method on Large Scale

    Directory of Open Access Journals (Sweden)

    Y. F. Liang

    2015-01-01

    Full Text Available Melt spinning method has been widely applied for fabrication of Fe-based amorphous/nanocrystalline ribbons in industry. Compared with Fe-based amorphous/nanocrystalline alloys, Fe-6.5wt%Si high silicon steel is of low cost and has comparable excellent soft magnetic properties. Due to higher melting point and absence of supercooled liquid region, fabrication of Fe-6.5wt%Si ribbons is very hard and is only on lab scale. In this paper, we report that large scale fabrication of Fe-6.5wt%Si ribbons was successful and microstructures, ordered structures, and mechanical and soft magnetic properties of the ribbons were investigated. Due to rapid solidification rate, the ribbons were of ultrafine grains, and low degree of order and exhibited some extent of bending and tensile ductility. After heat treatment, excellent soft magnetic properties were obtained. Due to near-zero magnetostriction, the ribbons are promising to be used in electric devices with high frequencies where low noises are required.

  12. VAK III. Seals and sealing system

    International Nuclear Information System (INIS)

    d'Agraives, B.C.; Dal Cero, G.; Debeir, R.; Mascetti, E.; Toornvliet, J.; Volcan, A.

    1986-01-01

    This report presents the VAK III seals and sealing system, which have been used over a period of two years at the Kahl nuclear facility (Federal Republic of Germany), where field tests and feasibility studies were conducted in order to offer a possible solution for the sealing of LWR fuel assemblies. It has been prepared with the aim of an assessment study to be done at the IAEA. It gives all characteristics and technical descriptions for: the sealing principle, the seal construction, the operating tools, the data processing, the drawings, the publications related to that seal. The main points of progress are: the Strong Random Internal Defects (STRID) incorporated in the seals, allowing the obtention of a good signature stability; the Integrity Check on the Seal Status (broken or not) obtained through a decisive mechanical improvement: the Double Breakage Integrity Check (DOBRIC) and with a better ultrasonic evidence of that status; the provision of new function tools, allowing the performance of Identity Measurements in dry conditions (which means also at the manufacturer plant) or in deeper water (wet storage); the study and development of a new JRC VAK 45 Compact Instrument Box, in which all the measuring functions can be grouped and incorporating an autonomous Minicomputer offering to the Inspection the possibility of performing, on the spot, Correlation and Decision processes. The general benefit of such a feasibility study should be to convince the potential users that such a Safeguards Sealing System can be studied for slightly - or largely - different other applications, provided that the Basic and Operating Functions required to the system be clearly defined, possibly after a common agreement would be stated

  13. Piezoelectric ribbons printed onto rubber for flexible energy conversion.

    Science.gov (United States)

    Qi, Yi; Jafferis, Noah T; Lyons, Kenneth; Lee, Christine M; Ahmad, Habib; McAlpine, Michael C

    2010-02-10

    The development of a method for integrating highly efficient energy conversion materials onto stretchable, biocompatible rubbers could yield breakthroughs in implantable or wearable energy harvesting systems. Being electromechanically coupled, piezoelectric crystals represent a particularly interesting subset of smart materials that function as sensors/actuators, bioMEMS devices, and energy converters. Yet, the crystallization of these materials generally requires high temperatures for maximally efficient performance, rendering them incompatible with temperature-sensitive plastics and rubbers. Here, we overcome these limitations by presenting a scalable and parallel process for transferring crystalline piezoelectric nanothick ribbons of lead zirconate titanate from host substrates onto flexible rubbers over macroscopic areas. Fundamental characterization of the ribbons by piezo-force microscopy indicates that their electromechanical energy conversion metrics are among the highest reported on a flexible medium. The excellent performance of the piezo-ribbon assemblies coupled with stretchable, biocompatible rubber may enable a host of exciting avenues in fundamental research and novel applications.

  14. Broadband magnetic losses of nanocrystalline ribbons and powder cores

    Energy Technology Data Exchange (ETDEWEB)

    Beatrice, Cinzia, E-mail: c.beatrice@inrim.it [Istituto Nazionale di Ricerca Metrologica, Nanoscience and Materials Division, Torino (Italy); Dobák, Samuel [Institute of Physics, Faculty of Science, P.J. Šafárik University, Košice (Slovakia); Ferrara, Enzo; Fiorillo, Fausto [Istituto Nazionale di Ricerca Metrologica, Nanoscience and Materials Division, Torino (Italy); Ragusa, Carlo [Politecnico di Torino, Energy Department, Torino (Italy); Füzer, Ján; Kollár, Peter [Institute of Physics, Faculty of Science, P.J. Šafárik University, Košice (Slovakia)

    2016-12-15

    Finemet type alloys have been investigated from DC to 1 GHz at different induction levels upon different treatments: as amorphous precursors, as ribbons nanocrystallized with and without an applied saturating field, as consolidated powders. The lowest energy losses at all frequencies and maximum Snoek's product are exhibited by the transversally field-annealed ribbons. This is understood in terms of rotation-dominated magnetization process in the low-anisotropy material. Intergrain eddy currents are responsible for the fast increase of the losses with frequency and for early permeability relaxation of the powder cores. Evidence for resonant phenomena at high frequencies and for the ensuing inadequate role of the static magnetic constitutive equation of the material in solving the magnetization dynamics via the Maxwell's diffusion equation of the electromagnetic field is provided. It is demonstrated that, by taking the Landau–Lifshitz–Gilbert equation as a constitutive relation, the excellent frequency response of the transverse anisotropy ribbons can be described by analytical method.

  15. Performance of candidate gas turbine abradeable seal materials in high temperature combustion atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Simms, N.J. [Cranfield University, Power Generation Technology Centre, Cranfield, Beds, MK43 0AL (United Kingdom); Norton, J.F. [Cranfield University, Power Generation Technology Centre, Cranfield, Beds, MK43 0AL (United Kingdom); Consultant in Corrosion Science and Technology, Hemel Hempstead, Herts HP1 1SR (United Kingdom); McColvin, G. [Siemens Industrial Turbines Ltd., Lincoln, LN5 7FD (United Kingdom)

    2005-11-01

    The development of abradeable gas turbine seals for higher temperature duties has been the target of an EU-funded R and D project, ADSEALS, with the aim of moving towards seals that can withstand surface temperatures as high as {proportional_to} 1100 C for periods of at least 24,000 h. The ADSEALS project has investigated the manufacturing and performance of a number of alternative materials for the traditional honeycomb seal design and novel alternative designs. This paper reports results from two series of exposure tests carried out to evaluate the oxidation performance of the seal structures in combustion gases and under thermal cycling conditions. These investigations formed one part of the evaluation of seal materials that has been carried out within the ADSEALS project. The first series of three tests, carried out for screening purposes, exposed candidate abradeable seal materials to a simulated natural gas combustion environment at temperatures within the range 1050-1150 C in controlled atmosphere furnaces for periods of up to {proportional_to} 2,500 h with fifteen thermal cycles. The samples were thermally cycled to room temperature on a weekly basis to enable the progress of the degradation to be monitored by mass change and visual observation, as well as allowing samples to be exchanged at planned intervals. The honeycombs were manufactured from PM2000 and Haynes 214. The backing plates for the seal constructions were manufactured from Haynes 214. Some seals contained fillers or had been surface treated (e.g. aluminised). The second series of three tests were carried out in a natural gas fired ribbon furnace facility that allowed up to sixty samples of candidate seal structures (including honeycombs, hollow sphere structures and porous ceramics manufactured from an extended range of materials including Aluchrom YHf, PM2Hf, Haynes 230, IN738LC and MarM247) to be exposed simultaneously to a stream of hot combustion gas. In this case the samples were cooled

  16. Alaska Phocid Food Habits

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Relatively little is known of the diet and foraging behaviors of the four species of ice-associated seals (ribbon seal, bearded seal, spotted seal, and ringed seal)...

  17. Cover-gas seals: 11-LMFBR seal-test program

    International Nuclear Information System (INIS)

    Steele, O.P. III; Horton, P.H.

    1977-01-01

    The objective of the Cover Gas Seal Material Development Program is to perform the engineering development required to provide reliable seals for LMFBR application. Specific objectives are to verify the performance of commercial solid cross-section and inflatable seals under reactor environments including radiation, to develop advanced materials and configurations capable of achieving significant improvement in radioactive gas containment and seal temperature capabilities, and to optimize seal geometry for maximum reliability and minimal gas permeation

  18. A CIRCULAR-RIBBON SOLAR FLARE FOLLOWING AN ASYMMETRIC FILAMENT ERUPTION

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chang; Deng, Na; Lee, Jeongwoo; Wang, Haimin [Space Weather Research Laboratory, New Jersey Institute of Technology, University Heights, Newark, NJ 07102-1982 (United States); Liu, Rui [CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei 230026 (China); Pariat, Étienne [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universits, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, F-92190 Meudon (France); Wiegelmann, Thomas [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig Weg 3, D-37077 Göttingen (Germany); Liu, Yang [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305-4085 (United States); Kleint, Lucia, E-mail: chang.liu@njit.edu [University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch (Switzerland)

    2015-10-20

    The dynamic properties of flare ribbons and the often associated filament eruptions can provide crucial information on the flaring coronal magnetic field. This Letter analyzes the GOES-class X1.0 flare on 2014 March 29 (SOL2014-03-29T17:48), in which we found an asymmetric eruption of a sigmoidal filament and an ensuing circular flare ribbon. Initially both EUV images and a preflare nonlinear force-free field model show that the filament is embedded in magnetic fields with a fan-spine-like structure. In the first phase, which is defined by a weak but still increasing X-ray emission, the western portion of the sigmoidal filament arches upward and then remains quasi-static for about five minutes. The western fan-like and the outer spine-like fields display an ascending motion, and several associated ribbons begin to brighten. Also found is a bright EUV flow that streams down along the eastern fan-like field. In the second phase that includes the main peak of hard X-ray (HXR) emission, the filament erupts, leaving behind two major HXR sources formed around its central dip portion and a circular ribbon brightened sequentially. The expanding western fan-like field interacts intensively with the outer spine-like field, as clearly seen in running difference EUV images. We discuss these observations in favor of a scenario where the asymmetric eruption of the sigmoidal filament is initiated due to an MHD instability and further facilitated by reconnection at a quasi-null in corona; the latter is in turn enhanced by the filament eruption and subsequently produces the circular flare ribbon.

  19. Pseudo ribbon metal ion beam source

    International Nuclear Information System (INIS)

    Stepanov, Igor B.; Ryabchikov, Alexander I.; Sivin, Denis O.; Verigin, Dan A.

    2014-01-01

    The paper describes high broad metal ion source based on dc macroparticle filtered vacuum arc plasma generation with the dc ion-beam extraction. The possibility of formation of pseudo ribbon beam of metal ions with the parameters: ion beam length 0.6 m, ion current up to 0.2 A, accelerating voltage 40 kV, and ion energy up to 160 kV has been demonstrated. The pseudo ribbon ion beam is formed from dc vacuum arc plasma. The results of investigation of the vacuum arc evaporator ion-emission properties are presented. The influence of magnetic field strength near the cathode surface on the arc spot movement and ion-emission properties of vacuum-arc discharge for different cathode materials are determined. It was shown that vacuum-arc discharge stability can be reached when the magnetic field strength ranges from 40 to 70 G on the cathode surface

  20. Pseudo ribbon metal ion beam source.

    Science.gov (United States)

    Stepanov, Igor B; Ryabchikov, Alexander I; Sivin, Denis O; Verigin, Dan A

    2014-02-01

    The paper describes high broad metal ion source based on dc macroparticle filtered vacuum arc plasma generation with the dc ion-beam extraction. The possibility of formation of pseudo ribbon beam of metal ions with the parameters: ion beam length 0.6 m, ion current up to 0.2 A, accelerating voltage 40 kV, and ion energy up to 160 kV has been demonstrated. The pseudo ribbon ion beam is formed from dc vacuum arc plasma. The results of investigation of the vacuum arc evaporator ion-emission properties are presented. The influence of magnetic field strength near the cathode surface on the arc spot movement and ion-emission properties of vacuum-arc discharge for different cathode materials are determined. It was shown that vacuum-arc discharge stability can be reached when the magnetic field strength ranges from 40 to 70 G on the cathode surface.

  1. Amorphous metal matrix composite ribbons

    International Nuclear Information System (INIS)

    Barczy, P.; Szigeti, F.

    1998-01-01

    Composite ribbons with amorphous matrix and ceramic (SiC, WC, MoB) particles were produced by modified planar melt flow casting methods. Weldability, abrasive wear and wood sanding examinations were carried out in order to find optimal material and technology for elevated wear resistance and sanding durability. The correlation between structure and composite properties is discussed. (author)

  2. Effects of surface crystallization and oxidation in nanocrystalline FeNbCuSiB(P) ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Butvinová, B., E-mail: beata.butvinova@savba.sk [Institute of Physics SAS, Dúbravská cesta 9, 845 11 Bratislava (Slovakia); Butvin, P. [Institute of Physics SAS, Dúbravská cesta 9, 845 11 Bratislava (Slovakia); Brzózka, K. [Department of Physics, University of Technology and Humanities in Radom, Krasickiego 54, 26-600 Radom (Poland); Kuzminski, M. [Institute of Physics PAS, Al. Lotnikow 36/42, 02-668 Warsaw (Poland); Maťko, I.; Švec Sr, P. [Institute of Physics SAS, Dúbravská cesta 9, 845 11 Bratislava (Slovakia); Chromčíková, M. [Institute of Inorg. Chem. SAS, Centrum VILA, Študentská 2, 911 50 Trenčín (Slovakia)

    2017-02-15

    Si-poor Fe{sub 74}Nb{sub 3}Cu{sub 1}Si{sub 8}B{sub 14−x}P{sub x}, (x=0, 3) nanocrystalline ribbon-form alloys often form surfaces, which exert in-plane force on underlying ribbon interior when nanocrystallized in even modest presence of oxygen. Mostly unwanted hard-ribbon-axis magnetic anisotropy is standard result. Essential sources of the surface-caused stress have been sought and influence of P instead of B substitution on this effect was studied too. Preferred surface crystallization (PSC) was found to be the major reason. However P substitution suppresses PSC and promotes Fe-oxide formation, which eases the stress, softens the surfaces and provides different annealing evolution of surface properties. - Highlights: • Ar anneal of low-Si FeNbCuBSi ribbons produce surfaces that stress ribbon interior. • The stress comes mainly from preferred crystallization of surfaces. • Partial substitution of B by P changes annealing evolution of surface properties. • Without P, more crystalline surfaces significantly reduce ribbon's elasticity. • P suppresses surface crystallinity, promotes oxides and reduces mutual stress.

  3. Martensitic transformation behavior and shape memory properties of Ti-Ni-Pt melt-spun ribbons

    International Nuclear Information System (INIS)

    Inamura, Tomonari; Takahashi, Yohei; Hosoda, Hideki; Wakashima, Kenji; Nagase, Takeshi; Nakano, Takayoshi; Umakoshi, Yukichi; Miyazaki, Shuichi

    2006-01-01

    Martensitic transformation behavior and shape memory properties of a Ti 50 Ni 40 Pt 10 (TiNiPt) melt-spun ribbon fabricated by a single roll melt-spinning technique were characterized. The constituent phases of the as-spun ribbon were B2 (parent phase) and B19 (martensite phase) at room temperature. The B2-B19 martensitic transformation temperatures of the as-spun ribbon were 100K higher than those of the bulk-material with the same chemical composition. The martensitic transformation temperatures of the as-spun ribbon were decreased with increasing the temperature of the heat-treatment made after the melt-spinning. The as-spun ribbon and the heat-treated ribbons exhibited shape recovery by heating and/or pseudoelasticity. The martensitic transformation temperatures determined from the temperature dependence of the 0.2% flow stress of the pseudoelastic deformation were in good agreement with those of B2-B19 martensitic transformation determined by DSC. It was confirmed that the observed shape recovery and pseudoelasticity are shape memory effect and superelasticity due to the B2-B19 martensitic transformation. Shape memory effect and superelasticity of melt-spun TiNiPt alloy were found to appear at higher temperatures compared to those of Bulk-material with the same composition. (author)

  4. Mechanical seals

    CERN Document Server

    Mayer, E

    1977-01-01

    Mechanical Seals, Third Edition is a source of practical information on the design and use of mechanical seals. Topics range from design fundamentals and test rigs to leakage, wear, friction and power, reliability, and special designs. This text is comprised of nine chapters; the first of which gives a general overview of seals, including various types of seals and their applications. Attention then turns to the fundamentals of seal design, with emphasis on six requirements that must be considered: sealing effectiveness, length of life, reliability, power consumption, space requirements, and c

  5. Sealing device

    Science.gov (United States)

    Garcia-Crespo, Andres Jose

    2013-12-10

    A sealing device for sealing a gap between a dovetail of a bucket assembly and a rotor wheel is disclosed. The sealing device includes a cover plate configured to cover the gap and a retention member protruding from the cover plate and configured to engage the dovetail. The sealing device provides a seal against the gap when the bucket assemply is subjected to a centrifugal force.

  6. Laser-zone Growth in a Ribbon-to-ribbon (RTR) Process Silicon Sheet Growth Development for the Large Area Silicon Sheet Task of the Low Cost Solar Array Project

    Science.gov (United States)

    Baghdadi, A.; Gurtler, R. W.; Legge, R.; Sopori, B.; Rice, M. J.; Ellis, R. J.

    1979-01-01

    A technique for growing limited-length ribbons continually was demonstrated. This Rigid Edge technique can be used to recrystallize about 95% of the polyribbon feedstock. A major advantage of this method is that only a single, constant length silicon ribbon is handled throughout the entire process sequence; this may be accomplished using cassettes similar to those presently in use for processing Czochralski waters. Thus a transition from Cz to ribbon technology can be smoothly affected. The maximum size being considered, 3 inches x 24 inches, is half a square foot, and will generate 6 watts for 12% efficiency at 1 sun. Silicon dioxide has been demonstrated as an effective, practical diffusion barrier for use during the polyribbon formation.

  7. Evolutionary analysis of a novel zinc ribbon in the N-terminal region of threonine synthase.

    Science.gov (United States)

    Kaur, Gurmeet; Subramanian, Srikrishna

    2017-10-18

    Threonine synthase (TS) catalyzes the terminal reaction in the biosynthetic pathway of threonine and requires pyridoxal phosphate as a cofactor. TSs share a common catalytic domain with other fold type II PALP dependent enzymes. TSs are broadly grouped into two classes based on their sequence, quaternary structure, and enzyme regulation. We report the presence of a novel zinc ribbon domain in the N-terminal region preceding the catalytic core in TS. The zinc ribbon domain is present in TSs belonging to both classes. Our sequence analysis reveals that archaeal TSs possess all zinc chelating residues to bind a metal ion that are lacking in the structurally characterized homologs. Phylogenetic analysis suggests that TSs with an N-terminal zinc ribbon likely represents the ancestral state of the enzyme while TSs without a zinc ribbon must have diverged later in specific lineages. The zinc ribbon and its N- and C-terminal extensions are important for enzyme stability, activity and regulation. It is likely that the zinc ribbon domain is involved in higher order oligomerization or mediating interactions with other biomolecules leading to formation of larger metabolic complexes.

  8. Sealing Failure Analysis on V-Shaped Sealing Rings of an Inserted Sealing Tool Used for Multistage Fracturing Processes

    Directory of Open Access Journals (Sweden)

    Gang Hu

    2018-06-01

    Full Text Available The inserted sealing tool is a critical downhole implement that is used to balance the downhole pressure in multistage fracturing operations and prevent fracturing fluid from overflow and/or backward flow. The sealing ring of an inserted sealing tool plays an important role in downhole sealing since a sealing failure would ail the fracturing operation. In order to improve the sealing performance and reduce the potential fracturing failures, this research aims to investigate the influence of V-shaped sealing ring geometries on sealing performance. Constitutive experiments of rubber materials were carried out and the parameters of the constitutive relationship of rubber materials were obtained. A two-dimensional axisymmetric model considering the sealing ring has been established and influences are investigated with considerations of various system parameters and operating conditions. It is found that the stresses concentrated at the shoulder and inner vertex of the sealing ring have direct impact on the damage of the sealing rings under operational conditions. Moreover, the sealing interference, among several other factors, greatly affects the life of the sealing ring. A new design of the sealing ring is suggested with optimized geometric parameters. Its geometric parameters are the edge height of 5 mm, the vertex angle of 90°–100°, and the interference of 0.1 mm, which show a better performance and prolonged operation life of the sealing ring.

  9. HOOKED FLARE RIBBONS AND FLUX-ROPE-RELATED QSL FOOTPRINTS

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jie; Li, Hui [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, CAS, Nanjing 210008 (China); Gilchrist, Stuart A.; Aulanier, Guillaume; Schmieder, Brigitte; Pariat, Etienne, E-mail: nj.lihui@pmo.ac.cn [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris-Diderot, Sorbonne Paris Cité, 5 place Jules Janssen, F-92195 Meudon (France)

    2016-05-20

    We studied the magnetic topology of active region 12158 on 2014 September 10 and compared it with the observations before and early in the flare that begins at 17:21 UT (SOL2014-09-10T17:45:00). Our results show that the sigmoidal structure and flare ribbons of this active region observed by the Solar Dynamics Observatory /Atmospheric Imaging Assembly can be well reproduced from a Grad–Rubin nonlinear force-free field extrapolation method. Various inverse-S- and inverse-J-shaped magnetic field lines, which surround a coronal flux rope, coincide with the sigmoid as observed in different extreme-ultraviolet wavelengths, including its multithreaded curved ends. Also, the observed distribution of surface currents in the magnetic polarity where it was not prescribed is well reproduced. This validates our numerical implementation and setup of the Grad–Rubin method. The modeled double inverse-J-shaped quasi-separatrix layer (QSL) footprints match the observed flare ribbons during the rising phase of the flare, including their hooked parts. The spiral-like shape of the latter may be related to a complex pre-eruptive flux rope with more than one turn of twist, as obtained in the model. These ribbon-associated flux-rope QSL footprints are consistent with the new standard flare model in 3D, with the presence of a hyperbolic flux tube located below an inverse-teardrop-shaped coronal QSL. This is a new step forward forecasting the locations of reconnection and ribbons in solar flares and the geometrical properties of eruptive flux ropes.

  10. HOOKED FLARE RIBBONS AND FLUX-ROPE-RELATED QSL FOOTPRINTS

    International Nuclear Information System (INIS)

    Zhao, Jie; Li, Hui; Gilchrist, Stuart A.; Aulanier, Guillaume; Schmieder, Brigitte; Pariat, Etienne

    2016-01-01

    We studied the magnetic topology of active region 12158 on 2014 September 10 and compared it with the observations before and early in the flare that begins at 17:21 UT (SOL2014-09-10T17:45:00). Our results show that the sigmoidal structure and flare ribbons of this active region observed by the Solar Dynamics Observatory /Atmospheric Imaging Assembly can be well reproduced from a Grad–Rubin nonlinear force-free field extrapolation method. Various inverse-S- and inverse-J-shaped magnetic field lines, which surround a coronal flux rope, coincide with the sigmoid as observed in different extreme-ultraviolet wavelengths, including its multithreaded curved ends. Also, the observed distribution of surface currents in the magnetic polarity where it was not prescribed is well reproduced. This validates our numerical implementation and setup of the Grad–Rubin method. The modeled double inverse-J-shaped quasi-separatrix layer (QSL) footprints match the observed flare ribbons during the rising phase of the flare, including their hooked parts. The spiral-like shape of the latter may be related to a complex pre-eruptive flux rope with more than one turn of twist, as obtained in the model. These ribbon-associated flux-rope QSL footprints are consistent with the new standard flare model in 3D, with the presence of a hyperbolic flux tube located below an inverse-teardrop-shaped coronal QSL. This is a new step forward forecasting the locations of reconnection and ribbons in solar flares and the geometrical properties of eruptive flux ropes.

  11. Variation of boron concentration in metallic glass ribbons

    International Nuclear Information System (INIS)

    Nagy, A.Z.; Vasvari, B.; Bakos, L.; Duwez, P.; Bogancs, J.; Nazarov, V.M.

    1980-01-01

    The boron concentration of Fe 40 Ni 40 P 14 B 6 , Fe 32 Ni 36 Cr 14 P 12 B 6 and Fe 40 Ni 40 B 20 metallic glasses is measured by neutron activation analysis on both surfaces of the ribbon samples. It is found that the boron concentration is always higher on the bright side of the ribbon than that on the dull side which is in contact with the cold surface of the wheel during the rapid quenching from the melt. A possible explanation is given in terms of the solid-liquid interface moving rapidly from the cooled surface to the free surface when preparing the samples. (author)

  12. Low-frequency magnetization processes in chemically etched Co-based amorphous ribbons

    International Nuclear Information System (INIS)

    Betancourt, I.; Martinez, L.A.; Valenzuela, R.

    2005-01-01

    In this report we present a study of the magnetization processes for Co-based amorphous ribbons at low frequencies (10 Hz-13 MHz) as a function of decreasing thicknesses attained by chemical etching. Reversible domain-wall bulging, characterized by initial permeability and relaxation frequency, was monitored by means of inductance measurements. The real part of inductance (proportional to initial permeability) exhibited a decreasing trend with diminishing ribbon thickness, together with an increasing tendency for the relaxation frequency. For high amplitude of the ac field (leading to domain-wall unpinning), reduced ribbon thickness showed a deleterious-enhancement effect on irreversible domain-wall displacement, which was observed for both real and imaginary inductance spectroscopic plots. Results are interpreted in terms of reduced domain-wall pinning distances resulting from thinner alloy samples

  13. Cover gas seals: FFTF-LMFBR seal test program

    International Nuclear Information System (INIS)

    Kurzeka, W.; Oliva, R.; Welch, T.S.; Shimazaki, T.

    1974-01-01

    The objectives of this program are to: (1) conduct static and dynamic tests to demonstrate or determine the mechanical performance of full-size (cross section) FFTF fuel transfer machine and reactor vessel head seals intended for use in a sodium vapor-inert gas environment, (2) demonstrate that these FFTF seals or new seal configurations provide acceptable fission product and cover gas retention capabilities at Clinch River Breeder Reactor Plant (CRBRP) operating environmental conditions other than radiation, and (3) develop improved seals and seal technology for the CRBRP to support the national objective to reduce all atmospheric contaminations to low levels

  14. A new dental powder from nanocrystalline melt-spun Ag-Sn-Cu alloy ribbons

    International Nuclear Information System (INIS)

    Do-Minh, N.; Le-Thi, C.; Nguyen-Anh, S.

    2003-01-01

    A new non-gamma-two dental powder has been developed from nanocrystalline melt-spun Ag-Sn-Cu alloy ribbons. The amalgam made from this powder exhibits excellent properties for dental filling. The nanocrystalline microstructure was found for the first time in as-spun and heat treated Ag(27-28)Sn(9-32) Cu alloy ribbons, using X-ray diffraction, scanning electron microscopy and energy-dispersive spectroscopy. As-spun ribbons exhibited a multi-phase microstructure with preferred existence of β (Ag 4 Sn) phase formed during rapid solidification (RS) due to supersaturating of copper (Cu) atoms and homogenous nanostructure with subgrain size of about (40-50) nm, which seems to be developed during RS process and can be caused by eutectic reaction of the Ag 3 Sn/Ag 4 Sn-Cu 3 Sn system. In heat treated ribbons the clustering of Cu atoms was always favored and stable in an ageing temperature and time interval determined by Cu content. The heat treatment led to essential changes of subgrain morphology, resulted in the appearance of large-angle boundaries with fine Cu 3 Sn precipitates and forming typical recrystallization twins. Such a microstructure variation in melt-spun ribbons could eventually yield enhanced technological, clinical and physical properties of the dental products, controlled by the ADA Specification N deg 1 and reported before. Thus, using the rapid solidification technique a new non-gamma-two dental material of high quality, nanocrystalline ribbon powder, can be produced. Copyright (2003) AD-TECH - International Foundation for the Advancement of Technology Ltd

  15. Magnetic properties, phase evolution, and microstructure of the Co–Zr–V ribbons

    International Nuclear Information System (INIS)

    Hou, Zhipeng; Su, Feng; Xu, Shifeng; Zhang, Jinbao; Wu, Chunji; Liu, Dan; Wei, Beipei; Wang, Wenquan

    2013-01-01

    The substitution of V for Zr significantly impeded the growth of grain in the Co 82 Zr 18 ribbons during melt spinning and the amorphous Co 82 Zr 13 V 5 melt-spun ribbons were successfully produced at a wheel speed of 40 m/s. The values of coercivity H c and maximum energy product (BH) max first increased, reaching maximum at 560 °C and then they decreased sharply with increasing the annealing temperature. The optimal magnetic properties of H c =4.0 kOe and (BH) max =5.0 MGOe were obtained in the amorphous ribbons annealed at 560 °C. A suitable grain size of Co 11 Zr 2 phase was considered to be the main reason for the increase in coercivity. - Highlights: • High performance was obtained in Co 82 Zr 13 V 5 amorphous ribbons annealed. • We proved the hard magnetic phase was Co 11 Zr 2 phase. • Suitable grain size of Co 11 Zr 2 phase was the main reason for increase in coercivity

  16. Large magnetic entropy change in melt-spun LaFe11.5Si1.5 ribbons

    International Nuclear Information System (INIS)

    Xie Kun; Song Xiaoping; Zhu Yaoming; Lv Weipeng; Sun Zhanbo

    2004-01-01

    The microstructure transformation and the magnetic entropy change of LaFe 11.5 Si 1.5 melt-spun ribbons were investigated. The melt-spun ribbons show a homogeneous distribution of elements, and the homogeneity develops further after 5 h annealing. XRD results show that the ribbons are composed of NaZn 13 -type LaFe 11.5 Si 1.5 compounds and an α-Fe phase. After annealing, the ribbons crystallize well in the NaZn 13 -type structure and exhibit a very large magnetic entropy change. A first-order magnetic transition is observed in the annealed ribbons, and this is believed to be the origin of the large magnetic entropy. These results suggest that NaZn 13 -type LaFe 11.5 Si 1.5 compounds with a large magnetic entropy change can be produced by melt-spinning, the annealing time can be shortened significantly and the production cost of the magnetic refrigerant will be cut down accordingly

  17. Manufacture of ribbon and solar cells of material of semiconductor grade

    International Nuclear Information System (INIS)

    1980-01-01

    A method is described of producing ribbon-like substantially monocrystalline bodies of silicon or other materials of semiconductor grade suitable for use in solar cells or other semiconductor devices. A tube of the material is made and a photovoltaic junction formed in it. The tube is then divided lengthwise into a number of ribbon-like bodies. The photovoltaic junction can be formed either by diffusion or by ion-implantation. (U.K.)

  18. Failure analysis and seal life prediction for contacting mechanical seals

    Science.gov (United States)

    Sun, J. J.; He, X. Y.; Wei, L.; Feng, X.

    2008-11-01

    Fault tree analysis method was applied to quantitatively investigate the causes of the leakage failure of mechanical seals. It is pointed out that the change of the surface topography is the main reasons causing the leakage of mechanical seals under the condition of constant preloads. Based on the fractal geometry theory, the relationship between the surface topography and working time were investigated by experiments, and the effects of unit load acting on seal face on leakage path in a mechanical seal were analyzed. The model of predicting seal life of mechanical seals was established on the basis of the relationship between the surface topography and working time and allowable leakage. The seal life of 108 mechanical seal operating at the system of diesel fuel storage and transportation was predicted and the problem of the condition monitoring for the long-period operation of mechanical seal was discussed by this method. The research results indicate that the method of predicting seal life of mechanical seals is feasible, and also is foundation to make scheduled maintenance time and to achieve safe-reliability and low-cost operation for industrial devices.

  19. Ceramic Seal.

    Energy Technology Data Exchange (ETDEWEB)

    Smartt, Heidi A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Romero, Juan A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Custer, Joyce Olsen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hymel, Ross W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Krementz, Dan [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Gobin, Derek [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Harpring, Larry [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Martinez-Rodriguez, Michael [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Varble, Don [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); DiMaio, Jeff [Tetramer Technologies, Pendleton, SC (United States); Hudson, Stephen [Tetramer Technologies, Pendleton, SC (United States)

    2016-11-01

    Containment/Surveillance (C/S) measures are critical to any verification regime in order to maintain Continuity of Knowledge (CoK). The Ceramic Seal project is research into the next generation technologies to advance C/S, in particular improving security and efficiency. The Ceramic Seal is a small form factor loop seal with improved tamper-indication including a frangible seal body, tamper planes, external coatings, and electronic monitoring of the seal body integrity. It improves efficiency through a self-securing wire and in-situ verification with a handheld reader. Sandia National Laboratories (SNL) and Savannah River National Laboratory (SRNL), under sponsorship from the U.S. National Nuclear Security Administration (NNSA) Office of Defense Nuclear Nonproliferation Research and Development (DNN R&D), have previously designed and have now fabricated and tested Ceramic Seals. Tests have occurred at both SNL and SRNL, with different types of tests occurring at each facility. This interim report will describe the Ceramic Seal prototype, the design and development of a handheld standalone reader and an interface to a data acquisition system, fabrication of the seals, and results of initial testing.

  20. Ceramic Seal

    International Nuclear Information System (INIS)

    Smartt, Heidi A.; Romero, Juan A.; Custer, Joyce Olsen; Hymel, Ross W.; Krementz, Dan; Gobin, Derek; Harpring, Larry; Martinez-Rodriguez, Michael; Varble, Don; DiMaio, Jeff; Hudson, Stephen

    2016-01-01

    Containment/Surveillance (C/S) measures are critical to any verification regime in order to maintain Continuity of Knowledge (CoK). The Ceramic Seal project is research into the next generation technologies to advance C/S, in particular improving security and efficiency. The Ceramic Seal is a small form factor loop seal with improved tamper-indication including a frangible seal body, tamper planes, external coatings, and electronic monitoring of the seal body integrity. It improves efficiency through a self-securing wire and in-situ verification with a handheld reader. Sandia National Laboratories (SNL) and Savannah River National Laboratory (SRNL), under sponsorship from the U.S. National Nuclear Security Administration (NNSA) Office of Defense Nuclear Nonproliferation Research and Development (DNN R&D), have previously designed and have now fabricated and tested Ceramic Seals. Tests have occurred at both SNL and SRNL, with different types of tests occurring at each facility. This interim report will describe the Ceramic Seal prototype, the design and development of a handheld standalone reader and an interface to a data acquisition system, fabrication of the seals, and results of initial testing.

  1. Fiscal 1974 Sunshine Project result report. R and D on photovoltaic power generation system (R and D on Si ribbon crystal vertical pulling method); 1974 nendo taiyoko hatsuden system no kenkyu kaihatsu seika hokokusho. Silicon tatehiki ribbon kessho no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1975-05-30

    This research includes (1) basic study on Si ribbon crystal vertical pulling method, (2) basic design of continuous Si ribbon crystal vertical pulling mechanism, (3) basic study on vertically pulled Si ribbon crystal, (4) study on capillary materials for capillary crystal pulling method, and (5) basic study on AlAs-GaAs system compound semiconductors. In the 1st research, for Si ribbon crystal vertical pulling growth, the ribbon crystal pulling equipment was prepared and modified, and Si crystals were obtained by capillary and web methods. In the 2nd research, for development of Si ribbon crystal vertical pulling growth technology, study was made on the simple energy-saving resource-saving continuous automatic production process. In the 3rd research, measurement was made on various characteristics of ribbon crystals. In the 4th research, study was made on requirements of capillary materials from the viewpoint of capillary growth mechanism. In the 5th research, basic technology for solar cell production was established through growth experiments of AlAs-GaAs mixed crystals and multiple epitaxial crystal layers. (NEDO)

  2. Mechanical seal assembly

    Science.gov (United States)

    Kotlyar, Oleg M.

    2001-01-01

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transferring it to the mechanical diode.

  3. Mechanical Seal Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Kotlyar, Oleg M.

    1999-06-18

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transferring it to the mechanical diode.

  4. 75 FR 41808 - Narrow Woven Ribbons With Woven Selvedge From the People's Republic of China: Final Determination...

    Science.gov (United States)

    2010-07-19

    ... Ribbon Company, Inc. (``Petitioner''); Yama; and Yangzhou Bestpak Gifts & Crafts Co., Ltd. (``Bestpak... liquid petroleum gas from the supplier to Yama's factory.\\10\\ \\10\\ See Final Analysis Memorandum for Yama... limited to gift bags, gift boxes and/ or other types of ribbon. Narrow woven ribbons subject to the...

  5. Glass sealing

    Energy Technology Data Exchange (ETDEWEB)

    Brow, R.K.; Kovacic, L.; Chambers, R.S. [Sandia National Labs., Albuquerque, NM (United States)

    1996-04-01

    Hernetic glass sealing technologies developed for weapons component applications can be utilized for the design and manufacture of fuel cells. Design and processing of of a seal are optimized through an integrated approach based on glass composition research, finite element analysis, and sealing process definition. Glass sealing procedures are selected to accommodate the limits imposed by glass composition and predicted calculations.

  6. Rotary plug seal

    International Nuclear Information System (INIS)

    Ito, Koji; Abiko, Yoshihiro.

    1981-01-01

    Purpose: To enable fuel exchange even upon failure of regular seals and also to enable safety seal exchange by the detection of the reduction in the contact pressure of a rotary plug seal. Constitution: If one of a pair of regular tube seals for the rotary plug is failed during ordinary operation of a FBR type reactor, the reduction in the contact pressure of the seal to the plug gibbousness is detected by a pressure gauge and a solenoid valve is thereby closed. Thus, a back-up-tube seal provided above or below the tube seal is press-contacted by way of argon gas to the gibbousness to enter into operation state and lubricants are supplied from an oil tank. In such a structure, the back-up-tube seal is operated before the failure of the tube seal to enable to continue the fuel exchange work, as well as safety exchange for the tube seal. (Moriyama, K.)

  7. Silicon ribbon growth by a capillary action shaping technique. Annual report (Quarterly technical progress report No. 9)

    Energy Technology Data Exchange (ETDEWEB)

    Schwuttke, G.H.; Ciszek, T.F.; Kran, A.

    1977-10-01

    Progress on the technological and economical assessment of ribbon growth of silicon by a capillary action shaping technique is reported. Progress in scale-up of the process from 50 mm to 100 mm ribbon widths is presented, the use of vitreous carbon as a crucible material is analyzed, and preliminary tests of CVD Si/sub 3/N/sub 4/ as a potential die material are reported. Diffusion length measurements by SEM, equipment and procedure for defect display under MOS structure in silicon ribbon for lifetime interpretation, and an assessment of ribbon technology are discussed. (WHK)

  8. Sealing performance of a magnetic fluid seal for rotary blood pumps.

    Science.gov (United States)

    Mitamura, Yoshinori; Takahashi, Sayaka; Kano, Kentaro; Okamoto, Eiji; Murabayashi, Shun; Nishimura, Ikuya; Higuchi, Taka-Aki

    2009-09-01

    A magnetic fluid (MF) for a rotary blood pump seal enables mechanical contact-free rotation of the shaft and, hence, has excellent durability. The performance of a MF seal, however, has been reported to decrease in liquids. We have developed a MF seal that has a "shield" mechanism and a new MF with a higher magnetization of 47.9 kA/m. The sealing performance of the MF seal installed in a rotary blood pump was studied. Under the condition of continuous flow, the MF seal remained in perfect condition against a pressure of 298 mm Hg (pump flow rate: 3.96 L/min). The seal was also perfect against a pressure of 170 mm Hg in a continuous flow of 3.9 L/min for 275 days. We have developed a MF seal that works in liquid against clinically used pressures. The MF seal is promising as a shaft seal for rotary blood pumps.

  9. The sandwich domain structure in a Fe-based amorphous ribbon with uniaxial magnetic anisotropy

    International Nuclear Information System (INIS)

    Zhmetko, D.N.; Matsura, A.V.; Troschenkov, Y.N.; Seidametov, S.V.

    2011-01-01

    The formation and motion of two domain walls parallel to the ribbon surface are discovered during its dynamic magnetic reversal. The domain walls form near by the middle plane of a ribbon and move to its opposite main surfaces with different velocities.

  10. Synthesis of MoS{sub 2} ribbons and their branched structures by chemical vapor deposition in sulfur-enriched environment

    Energy Technology Data Exchange (ETDEWEB)

    Mahyavanshi, Rakesh D., E-mail: rmahyavanshi@gmail.com [Department of Physical Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Kalita, Golap, E-mail: kalita.golap@nitech.ac.jp [Department of Physical Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Sharma, Kamal P. [Department of Physical Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Kondo, Masuharu; Dewa, Takeshita [Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Kawahara, Toshio [Department of Electronics and Information Engineering, Chubu University, 1200 Matsumoto-cho, Kasugai 487-8501 (Japan); Tanemura, Masaki [Department of Physical Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan)

    2017-07-01

    Highlights: • We demonstrate synthesis of monolayer MoS{sub 2} ribbons and their branched structures. • Unidirectional, bi and tri-directional growth of ribbons from the nucleation point are obtained. • Unidirectional and other branched structures can be synthesized controlling the composition of MoO{sub 3} and sulfur vapor. • The ribbons possess uneven edge structures with angles of 60° and 120°, indicating molybdenum and sulfur terminations. - Abstract: Here, we demonstrate the synthesis of monolayer molybdenum disulfide (MoS{sub 2}) ribbons and their branched structures by chemical vapor deposition (CVD) in sulfur-enriched environment. The growth of the MoS{sub 2} ribbons, triangular and other crystals significantly depends on the exposure of sulfur and concentration of molybdenum oxide (MoO{sub 3}) vapor on the substrate surface. The width and length of the synthesized ribbons is around 5–10 and 50–100 μm, respectively, where the width reduces from the nucleation point toward the end of the ribbon. Unidirectional, bi and tri-directional growth of ribbons from the nucleation point with an angle of 60° and 120° were obtained attributing to crystallographic growth orientation of MoS{sub 2} crystals. The directional growth of dichalcogenides ribbons is a significant challenge, our process shows that such unidirectional and other branched structures can be achieved by controlling the stoichiometric composition of MoO{sub 3} and sulfur exposure on the substrate surface. Interestingly, all the individual and branched ribbons possess uneven abundant edge structures, where the edges are formed with angles of 60° and 120°, indicating variation in molybdenum and sulfur edge terminations. The directional growth of MoS{sub 2} ribbons with defined edge structures in particular CVD condition can open up new possibilities for electronic and electrochemical applications.

  11. 38 CFR 21.9700 - Yellow Ribbon Program.

    Science.gov (United States)

    2010-07-01

    ... Yellow Ribbon Program and the student maintains satisfactory progress, conduct, and attendance according...) Based on student status (i.e. , undergraduate, graduate, doctoral), or (ii) For each subelement of the institution (i.e., college or professional school). The maximum amount specified for each subelement of the...

  12. Controlling the microstructure and associated magnetic properties of Ni0.2Mn3.2Ga0.6 melt-spun ribbons by annealing

    Directory of Open Access Journals (Sweden)

    Mahmud Khan

    2017-05-01

    Full Text Available Here we report on the structural and magnetic properties of Ni0.2Mn3.2Ga0.6 melt-spun ribbons. The as-spun ribbons were found to exhibit mixed cubic phases that transform to non-cubic structure upon annealing. Additionally, an amorphous phase was found to co-exist in all ribbons. The SEM images show that minor grain formation occurs on the as-spun ribbons. However, the formation of extensive nano-grains was observed on the surfaces of the annealed ribbons. While the as-spun ribbons exhibit predominantly paramagnetic behavior, the ribbons annealed under various thermal conditions were found to be ferromagnetic with a Curie temperature of about 380 K. The ribbons annealed at 450 °C for 30 minutes exhibit a large coercive field of about 2500 Oe. The experimental results show that the microstructure and associated magnetic properties of the ribbons can be controlled by annealing techniques. The coercive fields and the shape of the magnetic hysteresis loops vary significantly with annealing conditions. Exchange bias effects have also been observed in the annealed ribbons.

  13. ANALYSIS OF RIBBONING ON CONICAL YARN PACKAGE WOUND BY OPENEND SPINNING MACHINES

    Directory of Open Access Journals (Sweden)

    Resul FETTAHOV

    2001-03-01

    Full Text Available In this paper, Ribboning , one of the common faults in yarn packages, is mathematically analysed. If yarn is repeatly laid on top of or along the same path as the previously wound yarn, this duplication of yarn path on the package creates a defect known as ribboning. The number of turns of package (n per double traverse of yarn guide is calculated in two different way One is calculated the length of a coil on the package and total length of yarn in a double traverse; the other is considered transmission rate between drum and conical yarn package The result of two different approach is similar and the probable diameter of conical yarn package which ribboning is occurred is calculated and used on Schalafhorst-Autocore OE spinning machines.

  14. Electronic self-monitoring seal

    International Nuclear Information System (INIS)

    Campbell, J.W.

    1978-01-01

    The Electronic Self-Monitoring Seal is a new type of security seal which allows continuous verification of the seal's identity and status. The identity information is a function of the individual seal, time, and seal integrity. A description of this seal and its characteristics are presented. Also described are the use cycle for the seal and the support equipment for programming and verifying the seal

  15. Inboard seal mounting

    Science.gov (United States)

    Hayes, John R. (Inventor)

    1983-01-01

    A regenerator assembly for a gas turbine engine has a hot side seal assembly formed in part by a cast metal engine block having a seal recess formed therein that is configured to supportingly receive ceramic support blocks including an inboard face thereon having a regenerator seal face bonded thereto. A pressurized leaf seal is interposed between the ceramic support block and the cast metal engine block to bias the seal wear face into sealing engagement with a hot side surface of a rotary regenerator matrix.

  16. Security seal

    Science.gov (United States)

    Gobeli, Garth W.

    1985-01-01

    Security for a package or verifying seal in plastic material is provided by a print seal with unique thermally produced imprints in the plastic. If tampering is attempted, the material is irreparably damaged and thus detectable. The pattern of the imprints, similar to "fingerprints" are recorded as a positive identification for the seal, and corresponding recordings made to allow comparison. The integrity of the seal is proved by the comparison of imprint identification records made by laser beam projection.

  17. Orthogonal ribbons for suspending test masses in interferometric gravitational wave detectors

    International Nuclear Information System (INIS)

    Lee, B.H.; Ju, L.; Blair, D.G.

    2005-01-01

    We show that a simple modification of proposed ribbon suspensions for laser interferometric gravitational wave detectors can substantially reduce the amplitude of violin modes at the expense of a small deterioration of suspension thermal noise. Using low loss fused silica, large amplitude peaks which cause dynamic range problems can be reduced by 21 dB. The total number of horizontal longitudinal direction violin modes below 5 kHz is reduced to less than half that expected with conventional ribbon suspensions

  18. Orthogonal ribbons for suspending test masses in interferometric gravitational wave detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.H. [School of Physics, University of Western Australia, Crawley 6009, WA (Australia)]. E-mail: bhl@physics.uwa.edu.au; Ju, L. [School of Physics, University of Western Australia, Crawley 6009, WA (Australia); Blair, D.G. [School of Physics, University of Western Australia, Crawley 6009, WA (Australia)

    2005-05-23

    We show that a simple modification of proposed ribbon suspensions for laser interferometric gravitational wave detectors can substantially reduce the amplitude of violin modes at the expense of a small deterioration of suspension thermal noise. Using low loss fused silica, large amplitude peaks which cause dynamic range problems can be reduced by 21 dB. The total number of horizontal longitudinal direction violin modes below 5 kHz is reduced to less than half that expected with conventional ribbon suspensions.

  19. Graphene ribbon growth on structured silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Stoehr, Alexander; Link, Stefan; Starke, Ulrich [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); Baringhaus, Jens; Aprojanz, Johannes; Tegenkamp, Christoph [Institut fuer Festkoerperphysik, Leibniz Universitaet Hannover (Germany); Niu, Yuran [MAX IV Laboratory, Lund University (Sweden); present address: School of Physics and Astronomy, Cardiff University (United Kingdom); Zakharov, Alexei A. [MAX IV Laboratory, Lund University (Sweden); Chen, Chaoyu; Avila, Jose; Asensio, Maria C. [Synchrotron SOLEIL and Universite Paris-Saclay, Gif sur Yvette (France)

    2017-11-15

    Structured Silicon Carbide was proposed to be an ideal template for the production of arrays of edge specific graphene nanoribbons (GNRs), which could be used as a base material for graphene transistors. We prepared periodic arrays of nanoscaled stripe-mesas on SiC surfaces using electron beam lithography and reactive ion etching. Subsequent epitaxial graphene growth by annealing is differentiated between the basal-plane mesas and the faceting stripe walls as monitored by means of atomic force microscopy (AFM). Microscopic low energy electron diffraction (μ-LEED) revealed that the graphene ribbons on the facetted mesa side walls grow in epitaxial relation to the basal-plane graphene with an armchair orientation at the facet edges. The π-band system of the ribbons exhibits linear bands with a Dirac like shape corresponding to monolayer graphene as identified by angle-resolved photoemission spectroscopy (ARPES). (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Mechanical seal program

    International Nuclear Information System (INIS)

    Lowery, G.B.

    1983-01-01

    The experimental plans and timing for completion of the mechanical seal program for both the slurry and transfer pumps are given. The slurry pump seal program will be completed by April 1984 with turnover of two seals in pumps to SRP Tank 15H. Transfer pump seal design will be released for plant use by May 1984. Also included are various other pump and seal related tests

  1. Analysis of stress-strain relationships in silicon ribbon

    Science.gov (United States)

    Dillon, O. W., Jr.

    1984-01-01

    An analysis of stress-strain relationships in silicon ribbon is presented. A model to present entire process, dynamical Transit Analysis is developed. It is found that knowledge of past-strain history is significant in modeling activities.

  2. Gettering effects in RAD polysilicon ribbons: An XPS/AES study

    Energy Technology Data Exchange (ETDEWEB)

    Amarray, E.; Deville, J.P.; Quesada, J.

    1987-03-01

    Evidence for gettering effects during the various heat treatments applied to RAD ribbons were investigated with surface analysis methods. These heat treatments occur either during the burning-off process of the carbon support or during the POCl/sub 3/ diffusion, and transport metallic impurities near the surface of the sample. Oxidation of clean silicon surfaces, cleaved either in air or ultra-high vacuum, has shown that the same metallic impurities are brought near the surface by this treatment alone. It is thus suggested that controlled oxidations and heat treatments can be used to improve the electrical properties of polysilicon, and especially of ribbons.

  3. Secondary seal effects in hydrostatic non-contact seals for reactor coolant pump shaft

    International Nuclear Information System (INIS)

    Fujita, T.; Koga, T.; Tanoue, H.; Hirabayashi, H.

    1987-01-01

    The paper presents a seal flow analysis in a hydrostatic non-contact seal for a PWR coolant pump shaft. A description is given of the non-contact seal for the reactor coolant pump. Results are presented for a distortion analysis of the seal ring, along with the seal flow characteristics and the contact pressure profiles of the secondary seals. The results of the work confirm previously reported findings that the seal ring distortion is sensitive to the o-ring location (which was placed between the ceramic seal face and the seal ring retainer). The paper concludes that the seal flow characteristics and the tracking performance depend upon the dynamic properties of the secondary seal. (U.K.)

  4. Design optimization of seal structure for sealing liquid by magnetic fluids

    International Nuclear Information System (INIS)

    Liu Tonggang; Cheng Yusheng; Yang Zhiyi

    2005-01-01

    The durability of the magnetic fluid seal clearly decreases when sealing another liquid because of the interface instability caused by the applied magnetic field and the velocity difference of the two liquids. With an intention to establish a stable interface during sealing liquid, a new magnetic fluid seal was developed in this paper. The parameters of the structure were optimized by a simulation apparatus. And the magnetic fluid seal designed based on the optimum parameters shows good performance and long life for sealing lubricating oil

  5. Seal arrangement

    International Nuclear Information System (INIS)

    Dempsey, J.D.

    1978-01-01

    A hydraulically balanced face type shaft seal is provided in which the opening and closing seal face areas retain concentricity with each other in the event of lateral shaft displacement. The seal arrangement is for a vertical high pressure pump, indented for use in the cooling system of a nuclear reactor. (Auth.)

  6. Seroprevalence of Antibodies against Seal Influenza A(H10N7) Virus in Harbor Seals and Gray Seals from the Netherlands.

    Science.gov (United States)

    Bodewes, Rogier; Rubio García, Ana; Brasseur, Sophie M; Sanchez Conteras, Guillermo J; van de Bildt, Marco W G; Koopmans, Marion P G; Osterhaus, Albert D M E; Kuiken, Thijs

    2015-01-01

    In the spring and summer 2014, an outbreak of seal influenza A(H10N7) virus infection occurred among harbor seals (Phoca vitulina) off the coasts of Sweden and Denmark. This virus subsequently spread to harbor seals off the coasts of Germany and the Netherlands. While thousands of seals were reported dead in Sweden, Denmark and Germany, only a limited number of seals were found dead in the Netherlands. To determine the extent of exposure of seals in the Netherlands to influenza A/H10N7 virus, we measured specific antibody titers in serum samples from live-captured seals and seals admitted for rehabilitation in the Netherlands by use of a hemagglutination inhibition assay and an ELISA. In harbor seals in 2015, antibodies against seal influenza A(H10N7) virus were detected in 41% (32 out of 78) pups, 10% (5 out of 52) weaners, and 58% (7 out of 12) subadults or adults. In gray seals (Halichoerus grypus) in 2015, specific antibodies were not found in the pups (n = 26), but in 26% (5 out of 19) of the older animals. These findings indicate that, despite apparent low mortality, infection with seal influenza A(H10N7) virus was geographically widespread and also occurred in grey seals.

  7. Variation of magnetic properties with mischmetal content in the resource saving magnets of MM-Fe-B ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhu-bai, E-mail: lzbgj@163.com [Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010 (China); State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wang, Li-chen [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Geng, Xiao-peng [Inner Mongolia Baotou Steel Rare Earth Magnetic Materials Co.Ltd, Baotou 014030 (China); Hu, Feng-xia; Sun, Ji-rong; Shen, Bao-gen [State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2017-03-15

    Magnetic materials of MM-Fe-B (MM=mischmetal) ribbons were prepared using melt spinning method by varying the content of MM. The ribbons contain minor phases besides the main phase of Re{sub 2}Fe{sub 14}B. X-ray techniques show that the diffraction peak intensities of the minor phase Fe{sub 3}B vary with the content of constituent elements, indicating that the amount of minor phase could be tunable. The squareness of hysteresis loop is the best in MM{sub 13}Fe{sub 80.5}B{sub 6.5} ribbons, which should mainly ascribe to the less amount of minor phase. Henkel plots verify the more uniform magnetization reversals in MM{sub 13}Fe{sub 80.5}B{sub 6.5} ribbons, and the energy product achieves to the maximum of 12.74 MGOe with the coercivity of 6.50 kOe. With the increase of MM content the coercivity increases monotonically, and reaches to 9.13 kOe in MM{sub 15}Fe{sub 77.5}B{sub 7.5} ribbons, which should be related with the nature of the defects in the main phase. These investigations show that optimizing the content of constituent elements and phase constitution could improve magnetic properties in the resource-saving magnets of MM-Fe-B ribbons. - Highlights: • MM-Fe-B (MM=mischmetal) ribbons contains the minor phases besides the main phase of Re{sub 2}Fe{sub 14}B. • The amount of minor phases varies with the content of constituent elements. • The energy product of 12.74 MGOe is obtained in MM{sub 13}Fe{sub 80.5}B{sub 6.5} ribbons by optimizing the phase constitution.

  8. Device for investigation of magnetic flux jumps in ribbon superconductors

    International Nuclear Information System (INIS)

    Andrianov, A.V.; Bashkirov, Yu.A.; Kremlev, M.G.

    1986-01-01

    A device for simulation of magnetic flux jumps in superconductors of conducting magnet sandwich-type windings super-applyed of a ribbon conductor is described. A superconducting magnet with a measuring cassetter are the main elements of the device. An external magnetic field is generated by a two-sectional superconducting magnet permitting to simulate the shape of the magnetic field characteristic for sandwich-type windings. Maximum radial component of the magnetic field is 2 T. Jumps of the magnetic flux are recorded by induction transducers and the magnetic field-by Hall trasducer. The effect of coating of standard metal on magnetic flux jumps in Nb 3 Sn base superconducting ribbon is considered

  9. Use of intraventricular ribbon gauze to reduce particulate emboli during aortic valve replacement

    Directory of Open Access Journals (Sweden)

    Loubani Mahmoud

    2006-11-01

    Full Text Available Abstract Background The incidence of cerebrovascular accidents following aortic valve surgery remains a devastating complication. The aim of this study was to determine the number of potential embolic material arising during aortic valve replacement and to examine the efficacy of using ribbon gauze in the left ventricle during removal of the native valve and decalcification of the aortic annulus. Methods Ribbon gauze was inserted into the left ventricular cavity prior to aortic valve excision in an unselected, prospectively studied series of 30 patients undergoing aortic valve replacement. A further 30 lengths of ribbon gauze were soaked in the pericardiotomy blood of the same patients and all were subjected to histological analysis. Results The median number of tissue fragments from the aortic valve replacement group was significantly higher than in the control group 5 (0–18 versus 0 (0–1 (p = 3.6 × 10-5. The size of tissue fragments varied between 0.1 and 9.0 mm with a mean of 0.61 ± 1.12 mm and a median of 0.2 mm. There was a significantly higher number of tissue fragments associated with patients having surgery for aortic stenosis when compared with patients who had aortic regurgitation with median of 5 (0–18 versus 0 (0–3 (p = 0.8 × 10-3. Conclusion Significant capture of particulate debris by the intraventricular ribbon gauze suggests that the technique of left ventricular ribbon gauze insertion during aortic valve excision has merit.

  10. Properties of rapidly solidified Fe-Cr-Al ribbons for the use as automotive exhaust gas catalyst substrates

    International Nuclear Information System (INIS)

    Emmerich, K.

    1993-01-01

    Metallic honeycomb structures are used as catalyst substrates in automotive exhaust gas systems. This application requires an outstanding corrosion resistance at elevated temperatures of the substrate material. Technical improvements can be achieved by the use of rapid solidification technology for the production of the Fe-Cr-Al ribbons since the Al content can be substantially increased from about 5% Al in the conventionally rolled material to about 12% Al in the rapid solidified ribbon. As a result the lifetime of the ribbon in a higher-temperature corrosion environment is drastically increased. In addition the scale/metal adherance is improved. The impediment of recrystallization in the rapidly solidified ribbons prevents an embrittlement even in carbonizing atmospheres. (orig.)

  11. Seal design alternatives study

    International Nuclear Information System (INIS)

    Van Sambeek, L.L.; Luo, D.D.; Lin, M.S.; Ostrowski, W.; Oyenuga, D.

    1993-06-01

    This report presents the results from a study of various sealing alternatives for the WIPP sealing system. Overall, the sealing system has the purpose of reducing to the extent possible the potential for fluids (either gas or liquid) from entering or leaving the repository. The sealing system is divided into three subsystems: drift and panel seals within the repository horizon, shaft seals in each of the four shafts, and borehole seals. Alternatives to the baseline configuration for the WIPP seal system design included evaluating different geometries and schedules for seal component installations and the use of different materials for seal components. Order-of-magnitude costs for the various alternatives were prepared as part of the study. Firm recommendations are not presented, but the advantages and disadvantages of the alternatives are discussed. Technical information deficiencies are identified and studies are outlined which can provide required information

  12. Structural relaxation of Ni-Si-B amorphous ribbon

    NARCIS (Netherlands)

    Jurikova, A.; Csach, K.; Miskuf, J.; Ocelik, V.

    The structural relaxation of the Ni-Si-B amorphous ribbon was studied by means of differential scanning calorimetry and thermomechanical analysis. It was shown that considerable length changes associated with reversible structural relaxation were revealed after a previous creep applied at higher

  13. Variation of boron concentration in metallic glass ribbons

    International Nuclear Information System (INIS)

    Nagy, A.Z.; Vasvari, B.; Duwez, P.; Bakos, L.; Seres, Z.; Bogancs, J.; Nazarov, V.M.

    1979-12-01

    The surface boron concentration of Fe 40 Ni 40 P 14 B 6 , Fe 32 Ni 36 Cr 14 P 12 B 6 and Fe 40 Ni 40 B 20 metallic glasses was measured by neutron activation analysis on both sides of the ribbon samples. It was found that the boron concentration is always higher at the bright side of the ribbon than that at the dull side which is in contact with the cold surface of the wheel during the rapid quenching from the melt. A possible explanation is given in terms of the solid-liquid interface moving rapidly from the cooled surface to the free surface when preparing the samples. Range values of alpha-particles for some characteristic compositions of metallic glasses are tabulated. A mathematical technique for the deconvolution of experimental data is described and the listing of the Fortran program is enclosed. (author)

  14. Nuclear waste vault sealing

    International Nuclear Information System (INIS)

    Gyenge, M.

    1980-01-01

    A nuclear waste vault must be designed and built to ensure adequate isolation of the nuclear wastes from human contact. Consequently, after a vault has been fully loaded, it must be adequately sealed off to prevent radionuclide migration which may be provided by circulating groundwater. Vault sealing entails four major aspects, i.e.: (a) vault grouting; (b) borehole sealing; (c) buffer packing; and (d) backfilling. Of particular concern in vault sealing are the physical and chemical properties of the sealing material, its long-term durability and stability, and the techniques used for its emplacement. Present sealing technology and sealing materials are reviewed in terms of the particular needs of vault sealing. Areas requiring research and development are indicated

  15. Nozzle seal

    International Nuclear Information System (INIS)

    Herman, R.F.

    1977-01-01

    In an illustrative embodiment of the invention, a nuclear reactor pressure vessel, having an internal hoop from which the heated coolant emerges from the reactor core and passes through to the reactor outlet nozzles, is provided with sealing members operatively disposed between the outlet nozzle and the hoop. The sealing members are biased against the pressure vessel and the hoop and are connected by a leak restraining member establishing a leak-proof condition between the inlet and outlet coolants in the region about the outlet nozzle. Furthermore, the flexible responsiveness of the seal assures that the seal will not structurally couple the hoop to the pressure vessel

  16. Nozzle seal

    International Nuclear Information System (INIS)

    Walling, G.A.

    1977-01-01

    In an illustrative embodiment of the invention, a nuclear reactor pressure vessel, having an internal hoop from which the heated coolant emerges from the reactor core and passes through to the reactor outlet nozzles, is provided with sealing rings operatively disposed between the outlet nozzles and the hoop. The sealing rings connected by flexible members are biased against the pressure vessel and the hoop, establishing a leak-proof condition between the inlet and outlet coolants in the region about the outlet nozzle. Furthermore, the flexible responsiveness of the seal assures that the seal will not structurally couple the hoop to the pressure vessel. 4 claims, 2 figures

  17. Magnetocaloric properties of rapidly solidified Dy{sub 3}Co alloy ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez Llamazares, J. L., E-mail: jose.sanchez@ipicyt.edu.mx; Flores-Zúñiga, H.; Sánchez-Valdés, C. F. [Instituto Potosino de Investigación Científica y Tecnológica A.C., Camino a la Presa San José 2055 Col. Lomas 4" a, San Luis Potosí, S.L.P. 78216 (Mexico); Álvarez-Alonso, Pablo [Departamento de Electricidad y Electrónica, UPV/EHU, 48940 Leioa (Spain); Lara Rodríguez, G. A. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, México, D. F. 04510 (Mexico); Fernández-Gubieda, M. L. [Departamento de Electricidad y Electrónica, UPV/EHU, 48940 Leioa (Spain); BC Materials, Camino de Ibaizabal, Edificio 500, Planta 1, Parque Científico y Tecnológico de Zamudio, 48160 Derio (Spain)

    2015-05-07

    The magnetic and magnetocaloric (MC) properties of melt-spun ribbons of the Dy{sub 3}Co intermetallic compound were investigated. Samples were fabricated in an Ar environment using a homemade melt spinner system at a linear speed of the rotating copper wheel of 40 ms{sup −1}. X-ray diffraction analysis shows that ribbons crystallize into a single-phase with the Fe{sub 3}C-type orthorhombic crystal structure. The M(T) curve measured at 5 mT reveals the occurrence of a transition at 32 K from a first to a second antiferromagnetic (AFM) state and an AFM-to-paramagnetic transition at T{sub N} = 43 K. Furthermore, a metamagnetic transition is observed below T{sub N}, but the magnetization change ΔM is well below the one reported for bulk alloys. Below 12 K, large inverse MC effect and hysteresis losses are observed. This behavior is related to the metamagnetic transition. For a magnetic field change of 5 T (2 T) applied along the ribbon length, the produced ribbons show a peak value of the magnetic entropy change ΔS{sub M}{sup peak} of −6.5 (− 2.1) Jkg{sup −1}K{sup −1} occurring close to T{sub N} with a full-width at half-maximum δT{sub FWHM} of 53 (37) K, and refrigerant capacity RC = 364 (83) Jkg{sup −1} (estimated from the product |ΔS{sub M}{sup peak}| × δT{sub FWHM})

  18. Flexible ring seal

    International Nuclear Information System (INIS)

    Abbes, Claude; Gournier, Andre; Rouaud, Christian; Villepoix, Raymond de.

    1976-01-01

    The invention concerns a flexible metal ring seal, able to ensure a perfect seal between two bearings due to the crushing and elastic deformation properties akin to similar properties in elastomers. Various designs of seal of this kind are already known, particularly a seal made of a core formed by a helical wire spring with close-wound turns and with high axial compression ratio, closed on itself and having the shape of an annulus. This wire ring is surrounded by at least one envelope having at rest the shape of a toroidal surface of which the generating circle does not close on itself. In a particular design mode, the seal in question can include, around the internal spring, two envelopes of which one in contact with the spring is composed of a low ductility elastic metal, such as mild steel or stainless steel and the other is, on the contrary, made of a malleable metal, such as copper or nickel. The first envelope evenly distributes the partial crushing of the spring, when the seal is tightened, on the second envelope which closely fits the two surfaces between which the seal operates. The stress-crushing curve characteristic of the seal comprises two separate parts, the first with a relatively sharp slope corresponds to the start of the seal compression phase, enabling at least some of these curves to reach the requisite seal threshold very quickly, then, beyond this, a second part, practically flat, where the stress is appreciably constant for a wide operating bracket [fr

  19. Active Infrared Thermography for Seal Contamination Detection in Heat-Sealed Food Packaging

    Directory of Open Access Journals (Sweden)

    Karlien D’huys

    2016-11-01

    Full Text Available Packaging protects food products from environmental influences, assuring quality and safety throughout shelf life if properly performed. Packaging quality depends on the quality of the packaging material and of the closure or seal. A common problem possibly jeopardizing seal quality is the presence of seal contamination, which can cause a decreased seal strength, an increased packaging failure risk and leak formation. Therefore, early detection and removal of seal contaminated packages from the production chain is crucial. In this work, a pulsed-type active thermography method using the heated seal bars as an excitation source was studied for detecting seal contamination. Thermal image sequences of contaminated seals were recorded shortly after sealing. The detection performances of six thermal image processing methods, based on a single frame, a fit of the cooling profiles, thermal signal reconstruction, pulsed phase thermography, principal component thermography and a matched filter, were compared. High resolution digital images served as a reference to quantify seal contamination, and processed thermal images were mapped to these references. The lowest detection limit (equivalent diameter 0.60 mm was obtained for the method based on a fit of the cooling profiles. Moreover, the detection performance of this method did not depend strongly on the time after sealing at which recording of the thermal images was started, making it a robust and generally applicable method.

  20. Nuclear reactor sealing system

    International Nuclear Information System (INIS)

    McEdwards, J.A.

    1983-01-01

    A liquid metal-cooled nuclear reactor sealing system is disclosed. The nuclear reactor includes a vessel sealed at its upper end by a closure head. The closure head comprises at least two components, one of which is rotatable; and the two components define an annulus therebetween. The sealing system includes at least a first and second inflatable seal disposed in series in an upper portion of the annulus. The system further includes a dip seal extending into a body of insulation located adjacent a bottom portion of the closure head. The dip seal comprises a trough formed by a lower portion of one of the components, and a seal blade pendently supported from the other component and extending downwardly into the trough. A body of liquid metal is contained in the trough which submerges a portion of the seal blade. The seal blade is provided with at least one aperture located above the body of liquid metal for providing fluid communication between the annulus intermediate the dip seal and the inflatable seals, and a body of cover gas located inside the vessel. There also is provided means for introducing a purge gas into the annulus intermediate the inflatable seals and the seal blade. The purge gas is introduced in an amount sufficient to substantially reduce diffusion of radioactive cover gas or sodium vapor up to the inflatable seals. The purge gas mixes with the cover gas in the reactor vessel where it can be withdrawn from the vessel for treatment and recycle to the vessel

  1. The IRES electronic seal

    International Nuclear Information System (INIS)

    Autrusson, B.; Brochard, D.; Moreau, J.F.; Martin, J.C.

    2001-01-01

    In the framework of the French Support Program for the IAEA Safeguards, the 'Institut de Protection et de Surete Nucleaire' (IPSN), developed an electronic seal called Integrated and Reusable Electronic Seal (IRES) that enables independent verification by different inspectorates (IAEA, Euratom, and National Inspectorate). The seal can be remotely interrogated by radio frequency and integrated to other Containment/surveillance systems by serial line RS 485. Data are authenticated and the IRESMAG software manages in the seal reader all functionalities of the seal and records inspection data compatible with the IAEA's Seal Database. To perform this development, IPSN relies on industrial partners: SAPHYMO for the general architecture of the seal and the electronics, THALES for the authentication of data and the security of transmission. The main features of the IRES seal are the following: Interrogation by different inspectorate, allowing independent conclusions; Recording of events, including tampering, in a non-volatile memory; Authentication of data and enhanced security of the communication between the seal and the seal reader; Remote interrogation by an inspector or/and automatic for unattended systems or remote monitoring; Reusable after erasing the seal memory and replacement of the batteries

  2. Compliant seal development

    Science.gov (United States)

    Hendricks, Robert C.

    1993-10-01

    The compliant metallic seal combines the noncontact feature of the labyrinth seal, the low leakage of a mechanical seal, and the compliant nature of the brush seal. It consists of several thin metallic elements or leaves mounted within a ring which is press fit into the housing, and in form, sort of resembles a lip seal sections wiping the shaft. A second set of overlapping cover leaves are placed on top of the shaft riding leaves which reduces leakage and provides stiffness. The leaves can be straight or angle cut. The shaft riding fingers are designed with mismatched curvature to provide lift off similar to the Rayleigh lift pads in mechanical seals with leading edge clearances nearly twice those of the trailing edge as as shown by Fleming to be optimal for gas flows in convergent seal passages. Leading edge clearances range from 300 to 500 microinches. Balance pockets beneath the leaves provide fluid film feed to the 'Rayleigh lift' surface and the proper balance ratio (mechanical seal) when combined with the static pressure and film pressure. The leaves flex in the radial direction and accommodate thermomechanical behavior as well as axial motion and angular misalignment. In the static mode, there is a net closing force on the leaves. The seals were tested to 70 psi at speeds to 16,000 rpm or surface speeds to 330 fps and temperatures from ambient to 440 F. A slow cycle through the rig critical at 10,000 rpm induced a radial vibration response of 0.004 to 0.005 inch were accommodated by the seal. Preliminary performance data are encouraging demonstrating hydrodynamic liftoff and noncontacting operation at pressure and speeds typical of gas turbine engines. The leakage performance data are significantly better than commercial labyrinth and brush seals which should be expected as this design incorporates the features of the low leakage face or mechanical seal along with the flexibility of the brush configuration.

  3. Self-acting shaft seals

    Science.gov (United States)

    Ludwig, L. P.

    1978-01-01

    Self-acting seals are described in detail. The mathematical models for obtaining a seal force balance and the equilibrium operating film thickness are outlined. Particular attention is given to primary ring response (seal vibration) to rotating seat face runout. This response analysis reveals three different vibration models with secondary seal friction being an important parameter. Leakage flow inlet pressure drop and affects of axisymmetric sealing face deformations are discussed. Experimental data on self-acting face seals operating under simulated gas turbine conditions are given. Also a spiral groove seal design operated to 244 m/sec (800 ft/sec) is described.

  4. HMSRP Hawaiian Monk Seal Master Identification Records (seal)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains records of all individually identified Hawaiian monk seals since 1981. These seals were identified by PSD personnel and cooperating scientists...

  5. Temperature dependent evolution of wrinkled single-crystal silicon ribbons on shape memory polymers.

    Science.gov (United States)

    Wang, Yu; Yu, Kai; Qi, H Jerry; Xiao, Jianliang

    2017-10-25

    Shape memory polymers (SMPs) can remember two or more distinct shapes, and thus can have a lot of potential applications. This paper presents combined experimental and theoretical studies on the wrinkling of single-crystal Si ribbons on SMPs and the temperature dependent evolution. Using the shape memory effect of heat responsive SMPs, this study provides a method to build wavy forms of single-crystal silicon thin films on top of SMP substrates. Silicon ribbons obtained from a Si-on-insulator (SOI) wafer are released and transferred onto the surface of programmed SMPs. Then such bilayer systems are recovered at different temperatures, yielding well-defined, wavy profiles of Si ribbons. The wavy profiles are shown to evolve with time, and the evolution behavior strongly depends on the recovery temperature. At relatively low recovery temperatures, both wrinkle wavelength and amplitude increase with time as evolution progresses. Finite element analysis (FEA) accounting for the thermomechanical behavior of SMPs is conducted to study the wrinkling of Si ribbons on SMPs, which shows good agreement with experiment. Merging of wrinkles is observed in FEA, which could explain the increase of wrinkle wavelength observed in the experiment. This study can have important implications for smart stretchable electronics, wrinkling mechanics, stimuli-responsive surface engineering, and advanced manufacturing.

  6. Mn-silicide nanostructures aligned on massively parallel silicon nano-ribbons

    International Nuclear Information System (INIS)

    De Padova, Paola; Ottaviani, Carlo; Ronci, Fabio; Colonna, Stefano; Quaresima, Claudio; Cricenti, Antonio; Olivieri, Bruno; Dávila, Maria E; Hennies, Franz; Pietzsch, Annette; Shariati, Nina; Le Lay, Guy

    2013-01-01

    The growth of Mn nanostructures on a 1D grating of silicon nano-ribbons is investigated at atomic scale by means of scanning tunneling microscopy, low energy electron diffraction and core level photoelectron spectroscopy. The grating of silicon nano-ribbons represents an atomic scale template that can be used in a surface-driven route to control the combination of Si with Mn in the development of novel materials for spintronics devices. The Mn atoms show a preferential adsorption site on silicon atoms, forming one-dimensional nanostructures. They are parallel oriented with respect to the surface Si array, which probably predetermines the diffusion pathways of the Mn atoms during the process of nanostructure formation.

  7. Sealing devices

    International Nuclear Information System (INIS)

    Coulson, R.A.

    1980-01-01

    A sealing device for minimising the leakage of toxic or radioactive contaminated environments through a biological shield along an opening through which a flexible component moves that penetrates the shield. The sealing device comprises an outer tubular member which extends over a length not less than the maximum longitudinal movement of the component along the opening. An inner sealing block is located intermediate the length of the component by connectors and is positioned in the bore of the outer tubular member to slide in the bore and effect a seal over the entire longitudinal movement of the component. The cross-section of the device may be circular and the block may be of polytetrafluoroethylene or of nylon impregnated with molybdenum or may be metallic. A number of the sealing devices may be combined into an assembly for a plurality of adjacent longitudinally movable components, each adapted to sustain a tensile load, providing the various drives of a master-slave manipulator. (author)

  8. Test results of Nb3Sn ribbons for the Princeton D coil test program

    International Nuclear Information System (INIS)

    Kaugerts, J.; File, J.; Willard, J.W.

    1974-10-01

    A previously described D coil test program was modified. Details of a smaller Nb 3 Sn D coil test program are described. Cusp coil tests were made with several Nb 3 Sn composite ribbons. Measurements of both the quench and recovery currents as a function of magnetic field component perpendicular to the wide edge of the ribbon are presented. (auth)

  9. Hermetically Sealed Compressor

    Science.gov (United States)

    Holtzapple, Mark T.

    1994-01-01

    Proposed hermetically sealed pump compresses fluid to pressure up to 4,000 atm (400 MPa). Pump employs linear electric motor instead of rotary motor to avoid need for leakage-prone rotary seals. In addition, linear-motor-powered pump would not require packings to seal its piston. Concept thus eliminates major cause of friction and wear. Pump is double-ended diaphragm-type compressor. All moving parts sealed within compressor housing.

  10. Large Area Silicon Sheet by EFG. [quality control and productivity of edge-defined film-fed growth of ribbons

    Science.gov (United States)

    1979-01-01

    Influences on ribbon quality which might be caused by various materials of construction which are used in the growth furnace were assessed. At the present level of ribbon quality, which has produced 8.5% to 9.5% efficient solar cells, no particular influence of any furnace part was detected. The experiments led to the suspicion that the general environment and the somewhat unoptimized materials handling procedures might be responsible for the current variations in ribbon quality and that, therefore, continuous work with this furnace under rather more stringent environmental conditions and operating procedures could perhaps improve materials quality to some extent. The work on the multiple furnace was continued with two multiple growth runs being performed. In these runs, the melt replenishment system performed poorly and extensive modifications to it were designed to make reliable melt feeding for five ribbon growth possible. Additional characterization techniques for wide ribbons, stress measurements, and growth dynamics experiments are reported.

  11. Characterisation of melt spun Ni-Ti shape memory Ribbons' microstructure

    Science.gov (United States)

    Mehrabi, Kambiz; Brunčko, Mihael; Kneissl, Albert C.; Čolič, Miodrag; Stamenković, Dragoslav; Ferčec, Janko; Anžel, Ivan; Rudolf, Rebeka

    2012-06-01

    NiTi alloys are the most technologically important medical Shape Memory Alloys in a wide range of applications used in Orthopaedics, Neurology, Cardiology and interventional Radiology as guide-wires, self-expandable stents, stent grafts, inferior vena cava filters and clinical instruments. This paper discusses the use of rapid solidification by the melt spinning method for the preparation of thin NiTi ribbons for medical uses. Generally, the application of rapid solidification via melt-spinning can change the microstructure drastically, which improves ductility and shape memory characteristics and leads to samples with small dimensions. As the increase in the wheel speed led to a reduced ribbon thickness, the cooling rate increased and, therefore, the martensitic substructure became finer. Furthermore, no transition from the crystalline phase to the amorphous phase was obtained by increasing the cooling rate, even at a wheel speed of 30 m/s. Specimens for our metallographic investigation were cut from the longitudinal cross sections of melt-spun ribbons. Conventional TEM studies were carried out with an acceleration voltage of 120 kV. Additionally, the chemical composition of the samples was examined with a TEM equipped with an EDX analyser. The crystallographic structure was determined using Bragg-Brentano x-ray diffraction with Cu-Kα radiation at room temperature.

  12. Transverse magnetization and giant magnetoimpedance in amorphous ribbons

    International Nuclear Information System (INIS)

    Orue, I.; Garcia-Arribas, A.; Saad, A.; Cos, D. de; Barandiaran, J.M.

    2005-01-01

    In the classical approach giant magnetoimpedance (GMI) is driven by the transverse permeability of the sample, as excited by the current flowing through it. Transverse permeability is usually taken as a constant, while detailed magnetization processes are important for the interpretation of GMI data. In most cases the transverse permeability (or magnetization) is only guessed by looking at the longitudinal magnetization curve and direct determinations of such parameter are scarce in the literature. In this work we report on the operation of a simple setup which provides the transverse magnetization of amorphous ribbons as a function of the current intensity flowing through it, by means of the magnetooptical kerr effect (MOKE). The system has been tested on low magnetostriction amorphous ribbons of very soft character with both longitudinal and transverse anisotropy. The transverse magnetization as a function of both the current and a DC longitudinal field applied, was compared with magneto impedance measurements

  13. Reinforced seal component

    International Nuclear Information System (INIS)

    Jeanson, G.M.; Odent, R.P.

    1980-01-01

    The invention concerns a seal component of the kind comprising a soft sheath and a flexible reinforcement housed throughout the entire length of the sheath. The invention enables O ring seals to be made capable of providing a radial seal, that is to say between two sides or flat collars of two cylindrical mechanical parts, or an axial seal, that is to say between two co-axial axisymmetrical areas. The seal so ensured is relative, but it remains adequately sufficient for many uses, for instance, to ensure the separation of two successive fixed blading compartments of axial compressors used in gas diffusion isotope concentration facilities [fr

  14. Numerical Investigation of the Effect of Radial Lip Seal Geometry on Sealing Performance

    Science.gov (United States)

    Tok, G.; Parlar, Z.; Temiz, V.

    2018-01-01

    Sealing elements are often needed in industry and especially in machine design. With the change and development of machine technology from day to day, sealing elements show continuous development and change in parallel with these developments. Many factors influence the performance of the sealing elements such as shaft surface roughness, radial force, lip geometry etc. In addition, the radial lip seals must have a certain pre-load and interference in order to provide a good sealing. This also affects the friction torque. Researchers are developing new seal designs to reduce friction losses in mechanical systems. In the presented study, the effect of the lip seal geometry on sealing performance will be examined numerically. The numerical model created for this purpose will be verified with experimental data firstly. In the numerical model, shaft and seal will be modeled as hyper-elastic in 2D and 3D. NBR (Nitrile Butadiene Rubber) as seal material will be analyzed for the rotating shaft state at constant speed by applying a uniform radial force.

  15. Reactor vessel sealing plug

    International Nuclear Information System (INIS)

    Dooley, R.A.

    1986-01-01

    This invention relates to an apparatus and method for sealing the cold leg nozzles of a nuclear reactor pressure vessel from a remote location during maintenance and inspection of associated steam generators and pumps while the pressure vessel and refueling canal are filled with water. The apparatus includes a sealing plug for mechanically sealing the cold leg nozzle from the inside of a reactor pressure vessel. The sealing plugs include a primary and a secondary O-ring. An installation tool is suspended within the reactor vessel and carries the sealing plug. The tool telescopes to insert the sealing plug within the cold leg nozzle, and to subsequently remove the plug. Hydraulic means are used to activate the sealing plug, and support means serve to suspend the installation tool within the reactor vessel during installation and removal of the sealing plug

  16. Magnetoimpedance studies on urine treated Co{sub 66}Ni{sub 7}Si{sub 7}B{sub 20} ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Kotagiri, Ganesh [Advanced Magnetic Materials Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India); Markandeyulu, G., E-mail: mark@iitm.ac.in [Advanced Magnetic Materials Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India); Doble, Mukesh; Nandakumar, V. [Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036 (India)

    2015-11-15

    Magnetoimpedance (MI) response of Co{sub 66}Ni{sub 7}Si{sub 7}B{sub 20} ribbons treated with artificial urine with protein bovine serum albumin (BSA), artificial urine without protein BSA and healthy male urine was studied as a function of time of incubation. The maximum MI [(MI){sub m}] values of the ribbons treated with artificial urine without protein (RTAU) after 3 h, 6 h, 12 h and 24 h of incubation are 30% (at 4 MHz), 15% (at 5 MHz), 14% (at 10 MHz) and 8% (at 13 MHz) respectively. On the other hand, the respective (MI){sub m} values of the ribbons treated with artificial urine with protein (RTAUP) are 33% (at 4 MHz), 25% (at 5 MHz), 20% (at 8 MHz) and 15% (12 MHz). However (MI){sub m} values of the ribbons treated with healthy male urine (RTHMU) after 4 h, 5 h, 10 h and 15 h of incubation are 71% (at 3 MHz), 57% (at 3 MHz), 25% (at 6 MHz) and 25% (at 5 MHz), respectively. The saturation magnetization (M{sub s}) values of RTAU after 3 h, 6 h, 12 h and 24 h of incubation are 71 emu/g, 65 emu/g, 63 emu/g and 60 emu/g respectively whereas, the respective M{sub s} values of RTAUP are 73 emu/g, 69 emu/g, 67 emu/g and 64 emu/g. The M{sub s} values of RTHMU after 4 h, 5 h, 10 h and 15 h of incubation are 96 emu/g, 90 emu/g, 75 emu/g and 75 emu/g respectively. The decrease in M{sub s} and (MI){sub m} values in RTAU and RTAUP compared to as-quenched ribbon is related to the amounts of various elements etched out from the ribbons and increased surface roughness. The M{sub s} and (MI){sub m} values of RTHMU are seen to have increased after 4 h and 5 h of incubation, due to strain relaxation through removal of strain developed during rapid quenching of the ribbons. On the other hand, the M{sub s} and (MI){sub m} values of RTHMU after 10 h and 15 h have decreased due to deterioration of the surface of the ribbons and thus, increase in magnetic (surface) anisotropy. The decrease in (MI){sub m} and M{sub S} of RTAU with the time of incubation are more rapid compared to that

  17. High pressure shaft seal

    International Nuclear Information System (INIS)

    Martinson, A.R.; Rogers, V.D.

    1980-01-01

    In relation to reactor primary coolant pumps, mechanical seal assembly for a pump shaft is disclosed which features a rotating seal ring mounting system which utilizes a rigid support ring loaded through narrow annular projections in combination with centering non-sealing O-rings which effectively isolate the rotating seal ring from temperature and pressure transients while securely positioning the ring to adjacent parts. A stationary seal ring mounting configuration allows the stationary seal ring freedom of motion to follow shaft axial movement up to 3/4 of an inch and shaft tilt about the pump axis without any change in the hydraulic or pressure loading on the stationary seal ring or its carrier. (author)

  18. Does the seal licensing system in Scotland have a negative impact on seal welfare?

    Directory of Open Access Journals (Sweden)

    Laetitia Nunny

    2016-08-01

    Full Text Available This study examined the licensing system that permits seal shooting in Scotland, which was established under Part 6 Conservation of Seals of the Marine (Scotland Act 2010. Four approaches were used: data were collated and analyzed from both the Scottish Government and Scottish Marine Animal Stranding Scheme; a survey was sent to current license holders and informal interviews were conducted with key stakeholder types. Between February 2011 and the end of October 2015, 1229 gray seals and 275 common seals were reported shot under license to the Scottish Government. The numbers of seals reported as shot has reduced year-on-year since the licensing system was put in place. While some license holders, notably fish farms, were using some non-lethal forms of deterrent to reduce seal-related damage, these were often used alongside seal shooting. Of the seals reported as shot to the Scottish Government, only a small percentage were also reported to the Scottish Marine Animal Stranding Scheme, despite this being a licensing requirement. Only 2.3% of the shot gray seals and 4.5% of the shot common seals were necropsied. There is evidence from these necropsies that some seals had not died instantly or had not been shot in the manner recommended by the Scottish Seal Management Code of Practice. These preliminary results show that more carcasses need to be recovered and necropsied if the welfare implications of current seal shooting practice are to be properly assessed. The current legislation does not specify closed seasons to protect breeding seals and thirty-five per cent of necropsied seals were pregnant gray seals. Seals have also been shot during their lactation periods when pups are dependent on their mothers. This raises significant welfare concerns. The re-introduction of closed seasons specific to each species of seal is recommended along with greater effort to deploy non-lethal methods. Independent assessment of the number of seals being killed

  19. SSME Seal Test Program: Test results for sawtooth pattern damper seal

    Science.gov (United States)

    Childs, D. W.

    1986-01-01

    Direct and transverse force coefficients for 11, sawtooth-pattern, and damper-seal configurations were examined. The designation damper seal uses a deliberately roughened stator and smooth rotor to increase the net damping force developed by a seal. The designation sawtooth-pattern refers to a stator roughness pattern. The sawtooth pattern yields axial grooves in the stator which are interrupted by spacer elements which act as flow constrictions or dams. All seals use the same smooth rotor and have the same, constant, minimum clearance. The stators examined the consequences of changes in the following design parameters: (1) axial-groove depth; (2) number of teeth: (3) number of sawtooth sections; (4) number of spacer elements; (5) dam width; (6) axially aligned sawtooth sections versus axially-staggered sawtooth sections; and (7) groove geometry. It is found that none of the sawtooth-pattern seal performs as well as the best round-hole-pattern seal. Maximum damping configurations for the sawtooth and round-hole-pattern stators have comparable stiffness performance. Several of the sawtooth pattern stators outperformed the best round-hole pattern seal.

  20. Circumferential shaft seal

    Science.gov (United States)

    Ludwig, L. P. (Inventor)

    1981-01-01

    A circumferential shaft seal comprising two sealing rings held to a rotating shaft by means of a surrounding elastomeric band is disclosed. The rings are segmented and are of a rigid sealing material such as carbon or a polyimide and graphite fiber composite.

  1. Sealing arrangement for radioactive material

    International Nuclear Information System (INIS)

    Gray, I.L.S.; Sievwright, R.W.T.; Elliott, J.C.

    1993-01-01

    A sealing arrangement for hermetically sealing two mating surfaces comprises two seals arranged to lie between the surfaces. Each seal provides hermetic sealing over a respective different temperature range and lie serially along the surfaces between the regions to be isolated. A main seal integrity test arrangement is provided in the form of a port and passage. This allows for the introduction of a fluid into or the evacuation of a region between the two seals to detect a leak. The port is also provided with at least two test port seals which seal with a plug. The plug is also provided with a test port to allow the integrity of the test port seal to be tested. (UK)

  2. Fin Ray Stiffness and Fin Morphology Control Ribbon-Fin-Based Propulsion.

    Science.gov (United States)

    Liu, Hanlin; Taylor, Bevan; Curet, Oscar M

    2017-06-01

    Ribbon-fin-based propulsion has rich locomotor capabilities that can enhance the mobility and performance of underwater vehicles navigating in complex environments. Bony fishes using this type of propulsion send one or multiple traveling waves along an elongated fin with the actuation of highly flexible rays that are interconnected by an elastic membrane. In this work, we study how the use of flexible rays and different morphology can affect the performance of ribbon-fin propulsion. We developed a physical model composed of 15 rays that are interconnected with an elastic membrane. We tested four different ray flexural stiffness and four aspect ratios. The robotic model was tested in a low-turbulence flume under two flow conditions ([Formula: see text] wavelength/s). In two experimental sets, we measured fin kinematics, net surge forces, and power consumption. Using these data, we perform a thrust and power analysis of the undulating fin. We present the thrust coefficient, power coefficient, and propulsive efficiency. We find that the thrust generation was linear with the enclosed area swept by the fin, and square of the relative velocity between the incoming flow and traveling wave. The thrust coefficient levels off around 0.5. In addition, for our parameter range, we find that the power consumption scales by the cube of the effective tangential velocity of the rays [Formula: see text] (A is the amplitude of the ray oscillating motion, and [Formula: see text] is the angular velocity). We show that a decay in stiffness decreases both thrust production and power consumption. However, for rays with high flexural stiffness, the difference in thrust compared with rigid rays is minimal. Moreover, our results show that flexible rays can improve the propulsive efficiency compared with a rigid counterpart. Finally, we find that the morphology of ribbon fin affects its propulsive efficiency. For the aspect ratio considered in our experiments, [Formula: see text] was the most

  3. Severe service sealing solutions

    International Nuclear Information System (INIS)

    Metcalfe, R.; Wensel, R.

    1994-09-01

    Successful sealing usually requires much more than initial leak-tightness. Friction and wear must also be acceptable, requiring a good understanding of tribology at the sealing interface. This paper describes various sealing solutions for severe service conditions. The CAN2A and CAN8 rotary face seals use tungsten carbide against carbon-graphite to achieve low leakage and long lifetime in nuclear main coolant pumps. The smaller CAN6 seal successfully uses tungsten carbide against silicon carbide in reactor water cleanup pump service. Where friction in CANDU fuelling machine rams must be essentially zero, a hydrostatic seal using two silicon carbide faces is the solution. In the NRU reactor moderator pumps, where pressure is much lower, eccentric seals that prevent boiling at the seal faces are giving excellent service. All these rotary face seals rely on supplementary elastomer seals between their parts. An integrated engineering approach to high performance sealing with O-rings is described. This is epitomized in critical Space Shuttle applications, but is increasingly being applied in CANDU plants. It includes gland design, selection and qualification of material, quality assurance, detection of defects and the effects of lubrication, surface finish, squeeze, stretch and volume constraints. In conclusion, for the severe service applications described, customized solutions have more than paid for themselves by higher reliability, lower maintenance requirements and reduced outage time. (author)

  4. Research on seal control systems for international nuclear safeguard and the vulnerability assessment on the seals

    International Nuclear Information System (INIS)

    Zhang Hongjian; Liu Tianshu; Cao Fangfang; Xu Chunyan

    2014-01-01

    Safeguard seals, also called Tamper-indicating devices (TIDs), are widely used to detect tampering or unauthorized entry in the international safeguard and security systems, Seal control systems consist of seal implementing plan, seal development and the vulnerability assessment on tbe seals, effective implementing procedures and methods of the seals. The vulnerability assessment contents of safeguard seals, thermo-shrinked film seals being as an example, and seals control systems in the implementation program are researched. The seal control systems discuss task assignment, seals management flow and seals program data flow to promote applying effectively seals. The vulnerability assessment program of seals studies assurance level to some different tampering techniques and measures. The researches must promote utilizing seals effectively for nuclear security, non-proliferation of nuclear weapons, radioactive waste management, and the nuclear material accounting and control. (authors)

  5. Nanocrystallization in Co67Cr7Fe4Si8B14 Amorphous Alloy Ribbons

    Directory of Open Access Journals (Sweden)

    Zahra Jamili-Shirvan

    2013-12-01

    Full Text Available The nanocrystallization of Co67Fe4Cr7Si8B14 amorphous ribbons which prepared by planar flow melt spinning process (PFMS was investigated. Crystallization of the ribbons was studied by differential thermal analysis (DTA, X-ray diffraction (XRD and transmission electron microscopy (TEM. The DTA result of amorphous ribbon at heating rate of 10˚C/min showedoccurrence of phase transitions in two stages. The ribbons were isothermally annealed for 30 minutes in argon atmosphere at different temperatures between 300 and 650ºC with 25ºC steps. The magnetic properties of annealed samples were measured using a vibrating sample magnetometer (VSM. The VSM results revealed that optimum soft magnetic properties occurred at 400ºC. XRD patterns showed that the samples isothermally annealed up to 450ºC were amorphous, while TEM results at 400ºC indicated 7-8 nm mean size nanocrytallites in amorphous matrix and size of the nanocrystallites increased by increasing temperature. Also by X-ray diffraction pattern, precipitation of different phases at higher temperatures confirmed.

  6. Overexpression of guanylate cyclase activating protein 2 in rod photoreceptors in vivo leads to morphological changes at the synaptic ribbon.

    Directory of Open Access Journals (Sweden)

    Natalia López-del Hoyo

    Full Text Available Guanylate cyclase activating proteins are EF-hand containing proteins that confer calcium sensitivity to retinal guanylate cyclase at the outer segment discs of photoreceptor cells. By making the rate of cGMP synthesis dependent on the free intracellular calcium levels set by illumination, GCAPs play a fundamental role in the recovery of the light response and light adaptation. The main isoforms GCAP1 and GCAP2 also localize to the synaptic terminal, where their function is not known. Based on the reported interaction of GCAP2 with Ribeye, the major component of synaptic ribbons, it was proposed that GCAP2 could mediate the synaptic ribbon dynamic changes that happen in response to light. We here present a thorough ultrastructural analysis of rod synaptic terminals in loss-of-function (GCAP1/GCAP2 double knockout and gain-of-function (transgenic overexpression mouse models of GCAP2. Rod synaptic ribbons in GCAPs-/- mice did not differ from wildtype ribbons when mice were raised in constant darkness, indicating that GCAPs are not required for ribbon early assembly or maturation. Transgenic overexpression of GCAP2 in rods led to a shortening of synaptic ribbons, and to a higher than normal percentage of club-shaped and spherical ribbon morphologies. Restoration of GCAP2 expression in the GCAPs-/- background (GCAP2 expression in the absence of endogenous GCAP1 had the striking result of shortening ribbon length to a much higher degree than overexpression of GCAP2 in the wildtype background, as well as reducing the thickness of the outer plexiform layer without affecting the number of rod photoreceptor cells. These results indicate that preservation of the GCAP1 to GCAP2 relative levels is relevant for maintaining the integrity of the synaptic terminal. Our demonstration of GCAP2 immunolocalization at synaptic ribbons at the ultrastructural level would support a role of GCAPs at mediating the effect of light on morphological remodeling changes of

  7. Third nearest neighbor parameterized tight binding model for graphene nano-ribbons

    Directory of Open Access Journals (Sweden)

    Van-Truong Tran

    2017-07-01

    Full Text Available The existing tight binding models can very well reproduce the ab initio band structure of a 2D graphene sheet. For graphene nano-ribbons (GNRs, the current sets of tight binding parameters can successfully describe the semi-conducting behavior of all armchair GNRs. However, they are still failing in reproducing accurately the slope of the bands that is directly associated with the group velocity and the effective mass of electrons. In this work, both density functional theory and tight binding calculations were performed and a new set of tight binding parameters up to the third nearest neighbors including overlap terms is introduced. The results obtained with this model offer excellent agreement with the predictions of the density functional theory in most cases of ribbon structures, even in the high-energy region. Moreover, this set can induce electron-hole asymmetry as manifested in results from density functional theory. Relevant outcomes are also achieved for armchair ribbons of various widths as well as for zigzag structures, thus opening a route for multi-scale atomistic simulation of large systems that cannot be considered using density functional theory.

  8. The IRES electronic seal

    International Nuclear Information System (INIS)

    Gourlez, P.; Funk, P.; Brochard, D.; Moreau, J.F.; Martin, J.C.

    2001-01-01

    In the framework of the French Support Program for the IAEA Safeguards, the 'Institut de Protection et de Surete Nucleaire' (IPSN), developed an electronic seal called Integrated and Reusable Electronic Seal (IRES) that enables independent verification by different inspectorates (IAEA, Euratom, and National Inspectorate) Furthermore, a bilateral co-ordination between Euratom and French domestic safeguards takes place in some French facilities regarding a common approach concerning the seals especially in case of crisis situation. The seal can be remotely interrogated by radio frequency and integrated to other Containment/surveillance systems by serial line RS 485. Data are authenticated and the IRESMAG software manages in the seal reader all functionalities of the seal and records inspection data compatible with the IAEA's Seal Database

  9. Development of variable width ribbon heating elements for liquid metal and gas-cooled fast breeder reactor fuel rod simulators

    International Nuclear Information System (INIS)

    McCulloch, R.W.; Lovell, R.T.; Post, D.W.; Snyder, S.D.

    1980-01-01

    Variable width ribbon heating elements have been fabricated which provide a chopped cosine, variable heat flux profile for fuel rod simulators used in test loops by the Breeder Reactor Program Thermal Hydraulic Out-of-Reactor Safety test facility and the Gas-Cooled Fast Breeder Reactor Core Flow Test Loop. Thermal, mechanical, and electrical design considerations result in the derivation of an analytical expression for the ribbon contours. From this, the ribbons are machined and wound on numerically controlled equipment. Postprocessing and inspection results in a wound, variable width ribbon with the precise dimensional, electrical, and mechanical properties needed for use in fuel pin simulators

  10. Microstructure evolution in the rapidly quenched Fe{sub 78}Si{sub 9}B{sub 13} ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.-M., E-mail: weiminw@sdu.edu.c [Key Lab of Liquid Structure and Heredity of Materials, Shandong University, Jinan 250061 (China); Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Jin, S.F. [Key Lab of Liquid Structure and Heredity of Materials, Shandong University, Jinan 250061 (China); Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China); Zhang, J.T.; Huang, T.; Wang, L.; Bian, X.F. [Key Lab of Liquid Structure and Heredity of Materials, Shandong University, Jinan 250061 (China)

    2009-11-01

    We report microstructure evolution in as-spun Fe{sub 78}Si{sub 9}B{sub 13} ribbons under various wheel speeds (s), which was investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). With decreasing s, the volume fraction of the residual amorphous phase (V{sub a}) in the as-spun ribbons decreases gradually, and the total exothermic heat of the crystallization in the DSC curves also decreases, but the ratio of the exothermic heat of the second crystallization to the first one is on the contrary. alpha-Fe is found in the ribbon with s of 32.9 m/s, while alpha-Fe, eutectic alpha-Fe+Fe{sub 2}B, and Fe{sub 3}Si phases are found in ribbons with s of 25.6 and 18.3 m/s. The phase precipitating behavior in cooling processes is well consistent with the annealing process in the literatures.

  11. Cover-gas-seal component development: dynamic inflatable-plug seal improvement

    International Nuclear Information System (INIS)

    Horton, P.H.

    1977-01-01

    This report documents the 1) radial compliance and 2) low friction coating tests conducted on the CRBRP Rotating Plug Inflatable Seals per test plan N707TR810014. Test results show that narrowing the seal blade from 0.25 to 0.12 in. will effectively reduce dynamic drag from 30 to 20 lb/ft under nominal conditions and will increase seal radial compliance from 0.12 to 0.30 in. without an unacceptable rise in dynamic drag. Tests also demonstrated that application of a teflon coating to the seal wear surface reduced breakaway drag by 25% based on results of comparison dwells

  12. Effect of bar sealing parameters on OPP/MCPP heat seal strength

    Directory of Open Access Journals (Sweden)

    2007-11-01

    Full Text Available The effect of bar sealing parameters on the heat seal strength of oriented polypropylene (OPP/metallic cast polypropylene (MCPP laminate film was investigated. Based on the results obtained from the parametric study, a bar sealing process window was developed. All points drop within the process window are combinations of platen temperature and dwell time that produce acceptable heat seal. Optimum combinations are indicated by the lower border of the window. The plateau initiation temperature, Tpi of OPP/MCPP laminate film used in the present study occurred before the final melting temperature, Tmf of the sealant material. The highest achievable heat seal strength was at the plateau region, and the corresponding failure modes were delaminating, tearing or combine failure modes (delaminating and tearing. Minimum pressure level of 1.25 bars is necessary to bring the laminate interface into intimate contact in order to effect sealing.

  13. Characterization of consolidated rapidly solidified Cu-Nb ribbons

    International Nuclear Information System (INIS)

    Ebrahimi, F.; Henne, M.L.C.

    1997-01-01

    Copper-niobium ribbons produced by melt-spinning were compacted by swaging and consolidated using HIPping. Final processing to obtain in-situ composites was done by swaging. The strength of the composite is discussed in terms of the composition and morphology of the niobium phase as evaluated using electron microscopy techniques

  14. Comparative study on two different seal surface structure for reactor pressure vessel sealing behavior

    International Nuclear Information System (INIS)

    Chen Jun; Xiong Guangming; Deng Xiaoyun

    2014-01-01

    The seal surface structure is very important to reactor pressure vessel (RPV) sealing behavior. In this paper, two 3-D RPV sealing analysis finite models have been established with different seal surface structures, in order to study the influence of two structures. The separation of RPV upper and lower flanges, bolt loads and etc. are obtained, which are used to evaluate the sealing behavior of the RPV. Meanwhile, the comparative analysis of safety margin of two seal surface structural had been done, which provides the theoretical basis for RPV seal structure design optimization. (authors)

  15. Long-range ferromagnetism and magnetocaloric effects in rapidly quenched Ni50−xCoxMn50−yAly ribbons

    Directory of Open Access Journals (Sweden)

    Nguyen Thi Mai

    2017-03-01

    Full Text Available Ni50−xCoxMn50−yAly (x = 7 and 9; y = 17, 18 and 19 alloy ribbons were prepared by melt-spinning with a tangential velocity of copper wheel of 40 m s−1. X-ray diffraction patterns reveal multi-crystalline phase behavior in the fabricated ribbons. The shape of thermomagnetization curves clearly depends on Co and Al concentrations. The Curie temperatures (TC of the alloy ribbons strongly increase with increasing the Co concentration and slightly decrease with increasing the Al concentration. The martensitic-austenitic phase transition in the alloy ribbons can be manipulated by tuning Co and Al concentrations. The maximum magnetic entropy change |ΔSm|max of about 0.75 J kg−1 K−1 for a field change of 12 kOe at TC ≈ 364 K was achieved for the Ni43Co7Mn32Al18 ribbon. Critical analysis using the Arrott-Noaks and Kouvel–Fisher methods demonstrates the existence of a long-range ferromagnetic order in this ribbon.

  16. Effects of pre-deformation on the martensitic transformation and magnetocaloric property in Ni-Mn-Co-Sn ribbons

    International Nuclear Information System (INIS)

    Ma Sheng-Can; Xuan Hai-Cheng; Zhang Cheng-Liang; Wang Liao-Yu; Cao Qing-Qi; Wang Dun-Hui; Du You-Wei

    2010-01-01

    This paper investigates the martensitic transformation and magnetocaloric effect in pre-deformed Ni-Mn-Co-Sn ribbons. The experimental results show that the reverse martensitic transformation temperature T M increases with the increasing pre-pressure, suggesting that pre-deformation is another effective way to adjust T M in ferromagnetic shape memory alloys. Large magnetic entropy changes and refrigerant capacities are obtained in these ribbons as well. It also discusses the origin of the enhanced martensitic transformation temperature and magnetocaloric property in pre-deformed Ni-Mn-Co-Sn ribbons

  17. Seals in motion

    NARCIS (Netherlands)

    Brasseur, Sophie Marie Jacqueline Michelle

    2017-01-01

    The harbour seal Phoca vitulina and the grey seal Halichoerus grypus have been inhabitants of the Wadden Sea since millennia. Prehistoric findings indicate the presence of both species around 5000 BC. This changed dramatically in the mid Middle-Ages as around 1500 AC, the grey seal disappeared from

  18. Universal method for opnimal design main structural assemblies of steel structures stationary conveyor with hanging ribbon

    Directory of Open Access Journals (Sweden)

    Boslovyak P.V.

    2015-10-01

    Full Text Available The technique and the detailed algorithm for optimal design of steel structures hospitaltion of the conveyor with hang-ing ribbon. Developed a universal objective function together with the system-limited-subject to limits of main components of steel structures of stationary conveyor with hanging ribbon.

  19. Structural and Electrical Properties Characterization of Sb1.52Bi0.48Te3.0 Melt-Spun Ribbons

    Directory of Open Access Journals (Sweden)

    Viktoriia Ohorodniichuk

    2017-06-01

    Full Text Available Melt-spinning (MS has been reported as a promising tool to tailor the microstructure of bulk thermoelectric materials leading to enhanced thermoelectric performances. Here, we report on a detailed characterization of p-type Bi0.48Sb1.52Te3 ribbons produced by melt-spinning. The microstructure of the melt-spun ribbons has been studied by means of X-ray diffraction, scanning and transmission electron microscopy (TEM. The analyses indicate that the ribbons are highly-textured with a very good chemical homogeneity. TEM reveals clear differences in the microstructure at large and short-range scales between the surface that was in contact with the copper wheel and the free surface. These analyses further evidence the absence of amorphous regions in the melt-spun ribbons and the precipitation of elemental Te at the grain boundaries. Low-temperature electrical resistivity and thermopower measurements (20–300 K carried out on several randomly-selected ribbons confirm the excellent reproducibility of the MS process. However, the comparison of the transport properties of the ribbons with those of bulk polycrystalline samples of the same initial composition shows that MS leads to a more pronounced metallic character. This difference is likely tied to changes in deviations from stoichiometry due to the out-of-equilibrium conditions imposed by MS.

  20. Design and development of face seal type sealing plug for advanced heavy water reactor

    International Nuclear Information System (INIS)

    Bansal, S.; Bhattacharyya, S.; Patel, R.J.; Agrawal, R.G.; Vaze, K.K.

    2005-09-01

    Advanced Heavy Water Reactor is a vertical pressure tube type reactor having light water as its coolant and heavy water as moderator. Sealing plug is required to close the pressure boundary of main heat transport system of the reactor by preventing escape of light water/steam From the coolant channel. There are 452 coolant channels in the reactor located in square lattice pitch. Sealing plug is located at the top of each coolant channel (in the top end fitting). Top end fitting is having a stepped bore to create a sealing face. Sealing plug is held through its expanded jaws in a specially provided groove of the end fitting. The plug was designed and prototypes were manufactured considering its functional importance, intricate design and precision machining requirements. Sealing plug consists of about 20 components mostly made up of precipitation hardening stainless steel, which is suitable for water environment and meets other requirements of strength and resistance to wear and galling. Seal disc is a critical component of the sealing plug as it is the pressure-retaining component. It is a circular disc with protruded stem. One face of the seal disc is nickel plated in the peripheral area that creates the sealing by abutting against the sealing face provided in the end fitting. The typical shape and profile of seal disc provides flexibility and allows elastic deformation to assist in locking of sealing plug and creating adequate seating force for effective sealing. Design and development aspects of the sealing plug have been detailed out in this report. Also results of stress analysis and experimental studies for seal disc have been mentioned in the report. Stress analysis and experimental testing was required for the seal disc because high stresses are developed due to its exposure to high pressure and temperature environment of Main Heat Transport system. Hot testing was carried out to simulate the reactor-simulated condition. The performance was found to be

  1. Cover gas seals. 11 - FFTF-LMFBR seal-test program, January-March 1974

    International Nuclear Information System (INIS)

    Kurzeka, W.; Oliva, R.; Welch, F.

    1974-01-01

    The objectives of this program are to: (1) conduct static and dynamic tests to demonstrate or determine the mechanical performance of full-size (cross section) FFTF fuel transfer machine and reactor vessel head seals intended for use in a sodium vapor - inert gas environment, (2) demonstrate that these FFTF seals or new seal configuration provide acceptable fission product and cover gas retention capabilities at LMFBR Clinch River Plant operating environmental conditions other than radiation, and (3) develop improved seals and seal technology for the LMFBR Clinch River Plant to support the national objective to reduce all atmospheric contaminations to low levels

  2. The identification of a sensitizing component used in the manufacturing of an ink ribbon

    Science.gov (United States)

    Anderson, Stacey E.; Tapp, Loren; Durgam, Srinivas; Meade, B. Jean; Jackson, Laurel G.; Cohen, David E.

    2015-01-01

    Skin diseases including dermatitis constitute ≈ 30% of all occupational illnesses, with a high incidence in the printing industry. An outbreak of contact dermatitis among employees at an ink ribbon manufacturing plant was investigated by scientists from the National Institute for Occupational Safety and Health (NIOSH). Employees in the process areas of the plant were exposed to numerous chemicals and many had experienced skin rashes, especially after the introduction of a new ink ribbon product. To identify the causative agent(s) of the occupational dermatitis, the murine local lymph node assay (LLNA) was used to identify the potential of the chemicals used in the manufacture of the ink ribbon to induce allergic contact dermatitis. Follow-up patch testing with the suspected allergens was conducted on exposed employees. Polyvinyl butyral, a chemical component used in the manufacture of the ink ribbon in question and other products, tested positive in the LLNA, with an EC3 of 3.6%, which identifies it as a potential sensitizer; however, no employees tested positive to this chemical during skin patch testing. This finding has implications beyond those described in this report because of occupational exposure to polyvinyl butyral outside of the printing industry. PMID:22375946

  3. Seals Research at AlliedSignal

    Science.gov (United States)

    Ullah, M. Rifat

    1996-01-01

    A consortium has been formed to address seal problems in the Aerospace sector of Allied Signal, Inc. The consortium is represented by makers of Propulsion Engines, Auxiliary Power Units, Gas Turbine Starters, etc. The goal is to improve Face Seal reliability, since Face Seals have become reliability drivers in many of our product lines. Several research programs are being implemented simultaneously this year. They include: Face Seal Modeling and Analysis Methodology; Oil Cooling of Seals; Seal Tracking Dynamics; Coking Formation & Prevention; and Seal Reliability Methods.

  4. Brush seal performance measurement system

    OpenAIRE

    Aksoy, Serdar; Akşit, Mahmut Faruk; Aksit, Mahmut Faruk; Duran, Ertuğrul Tolga; Duran, Ertugrul Tolga

    2009-01-01

    Brush seals are rapidly replacing conventional labyrinth seals in turbomachinery applications. Upon pressure application, seal stiffness increases drastically due to frictional bristle interlocking. Operating stiffness is critical to determine seal wear life. Typically, seal stiffness is measured by pressing a curved shoe to brush bore. The static-unpressurized measurement is extrapolated to pressurized and high speed operating conditions. This work presents a seal stiffness measurement syste...

  5. Seals

    International Nuclear Information System (INIS)

    Welsher, R.A.G.

    1982-01-01

    An aperture through a biological shield is sealed by a flexible sheath having a beading at one end located on an annular member slidable in the aperture such that the beading bears in sealing engagement against the sides of the aperture. The annular member is retained by a retractable latch and can be rejected by pushing it out of the aperture using a replacement annular member with a replacement sheath thereon to butt against the annular member to be rejected. The replacement annular member may be mounted on a tubular device having an outer co-axial member for operating the latch when the replacement annular member butts against the annular member to be rejected. Applications include effecting a seal between a remote handling equipment and a wall through which the equipment extends. (author)

  6. 76 FR 38648 - Availability of the Geothermal Technologies Program Blue Ribbon Panel Report and Request for...

    Science.gov (United States)

    2011-07-01

    ....S. has lagged that of solar and wind energy. The purpose of the Blue Ribbon Panel meeting was to... Geothermal Technologies Program Blue Ribbon Panel Report and Request for Public Comment AGENCY: Office of... Panel (the Panel) on March 22/23, 2011 in Albuquerque, New Mexico for a guided discussion on the future...

  7. Electronic seal

    International Nuclear Information System (INIS)

    Musyck, E.

    1981-01-01

    An electronic seal is presented for a volume such as container for fissile materials. The seal encloses a lock for barring the space as well as a device for the detection and the recording of the intervention of the lock. (AF)

  8. Fish Marketing of Ribbon Fish (Trichiurus sp. in Nusantara Fishing Port (NFPat Palabuhanratu, West Java

    Directory of Open Access Journals (Sweden)

    Nur Bambang Azis

    2018-01-01

    Full Text Available The objective of this research is to study the marketing process of ribbon fish (Trichiurus sp., including the marketing margin, marketing agencies, traders and marketing channels The research was carried out for 3 mo in Nusantara Fishing Port (NFP, Palabuhanratu, Sukabumi, West Java. A case study was used in this research. A purposive sampling method was used to collect data from 55 respondents of fish marketing, consisting of fishermen, agents, traders, and retailers, who were involved in the marketing of ribbon fish in NFP Palabuhanratu. The result of the research showed that ribbon fish production in Palabuhanratu fluctuated from year to year. There are two types of ribbon fish marketing, i.e. type one is from fishermen to retailers, and type two is indirect marketing from fisherman to consumers through intermediate traders (exporters. The greatest marketing margin was obtained from the first type, while the smallest marketing margin was obtained from type two. The form of the market was considered to be oligopsony market. Fisherman’s share is greatest in the collectors and the smallest share is on retailers. Marketing process in traders is efficient due to its lowest margin and highest fisherman’s share.

  9. Effects of the ingot phase transition on microstructure and magnetic properties of CeNdFeB melt-spun ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xuchao [Division of Functional Materials Research, Central Iron and Steel Research Institute, Beijing 100081, China (China); College of Sciences, Northeastern University, Shenyang 110819 (China); Zhu, Minggang, E-mail: mgzhu@126.com [Division of Functional Materials Research, Central Iron and Steel Research Institute, Beijing 100081, China (China); Li, Wei; Zheng, Liyun; Guo, Zhaohui; Du, Xiao [Division of Functional Materials Research, Central Iron and Steel Research Institute, Beijing 100081, China (China); Du, An [College of Sciences, Northeastern University, Shenyang 110819 (China)

    2015-11-01

    The paper studies the phase transition of ingot with the composition (Ce{sub 50}Nd{sub 50}){sub 30}Fe{sub bal}Co{sub 4}Ga{sub 0.2}B{sub 0.92} after the annealing treatment at 1050 °C. The melt-spun ribbons which is prepared by the two treatment status ingots. The phase structure and microstructure morphologies of the ingots and melt-spun ribbons were analysed and observed by XRD and SEM. It was found that the grain size of the ribbons is on the nanometer scale. The EDS results show that there are four different phases in the ingot: (CeNd){sub 2}Fe{sub 14}B, α-Fe, Ce-rich phase and Nd-rich phase. After the annealing treatment, α-Fe, Ce-rich phase, and Nd-rich phase were obviously reduced and the contents of the main phase was significantly increased in the annealed ingot compared with the unanneal treatment ingot. The VSM results show that there is a peak waist in the ribbon which is prepared by the untreated ingot. Because the ingot is uneven, the ribbons may have the secondary phase, the Hcj is 8394 Oe. But the demagnetization curves of the ribbons, which is prepared by the annealed ingot, is relatively smooth and without the soft magnetic phase and the Hcj is 12,528 Oe, which is higher than the unanneal treatment ingot. We can know that the ingot with fine organization is the key factors to preparing high-performance ribbons.

  10. 77 FR 32938 - Narrow Woven Ribbons With Woven Selvedge From Taiwan: Preliminary Results of Antidumping Duty...

    Science.gov (United States)

    2012-06-04

    ... ribbons subject to the order include all narrow woven fabrics, tapes, and labels that fall within this... the manufacture of typewriter or printer ribbons; (5) Narrow woven labels and apparel tapes, cut-to... 1994 U.S.C.C.A.N. 4040, 4198-99. Furthermore, ``affirmative evidence of bad faith on the part of a...

  11. Magnetic and surface properties of Fe-Nb (Mo, V)-Cu-B-Si ribbons

    International Nuclear Information System (INIS)

    Butvinova, B.; Butvin, P.; Svec, P. Sr.; Matko, I.; Svec, P.; Janickovic, D.; Kadlecikova, M.

    2014-01-01

    The rapidly quenched Finemet (FeNbCuBSi) ribbons prepared by planar flow casting of the melt are very variable to obtain very good soft-magnetic properties. An appropriate thermal treatment leading to ultra-fine grain structure enables to attain such properties as desired for practical use. Increasing Fe percentage to the detriment of non-magnetic components lifts saturation induction above 1.3 T, preserves low coercivity and makes the alloy even cheaper to suit its mass production for use in power electronics. Apart from the plenty of benefits the ribbons show some risks. One of them is macroscopic heterogeneity, which often manifests via differences between surfaces and interior of a ribbon [3]. The surfaces squeeze (by in-plane force) the interior of many such ribbons and if engaged in magnetoelastic interaction, the force affects the resulting magnetic anisotropy [4]. Current research shows that changes of hysteresis loop shape come rather from surface crystallization and not from oxides namely in positively magnetostrictive alloys FeNbCuBSi known as low- Si Finemets. The object of this work is to verify whether the substitution of another element instead of Nb (usually incorporated as the grain-growth blocker) can change surface properties and affects the resulting magnetic properties. We chose V and Mo instead of Nb. Oxides, oxyhydroxides and a possible squeezing layer was looked for after higher temperature annealing which ensures partially nanocrystalline structure. (authors)

  12. A hybrid floating brush seal (HFBS) for improved sealing and wear performance in turbomachinery applications

    Science.gov (United States)

    Lattime, Scott Byran

    A conceptually new type of seal has been developed for gas turbine applications which dramatically reduces wear and leakage associated with current labyrinth and brush seal technologies. The Hybrid Floating Brush Seal (HFBS) combines brush seal and film riding face seal technologies to create a hybrid seal that allows both axial and radial excursions of the sealed shaft, while simultaneously eliminating interface surface speeds (friction and heat) between the rotor and the brush material that characterize standard brush seal technology. A simple test rig was designed to evaluate feasibility of the HFBS under relatively low pressures and rotational speeds (50psig, 5krpm). A second test stand was created to study the effects of centrifugal force on bristle deflection. A third test facility was constructed for prototype development and extensive room temperature testing at moderate pressures and fairly high rotational speeds (100psig, 40krpm). This test rig also allowed the evaluation of the HFBS during axial movement of a rotating shaft. An analytical model to predict the effects of centrifugal force on the bristles of a rotating brush seal was developed. Room temperature analysis of the HFBS proved successful for relatively high operating rotational velocities at moderate pressures with very acceptable leakage rates for gas turbine engines. Brush seals were able to track rotor speeds up to 24krpm while maintaining sealing integrity. The HFBS's ability to function under axial shaft displacement and synchronous dynamic radial loading was also proven successful. Hydrodynamic performance of the face seal was proven to provide adequate stiffness and load carrying capacity to keep the brush seal from contacting the face seal at pressure drops across the brush of up to 100psi. Leakage performance over standard brush seal and labyrinth technology was quite dramatic. The HFBS showed its sealing advantage using much higher radial interference between the rotor and the bristle

  13. Combined effects of vertical and lateral confinement on the magnetic properties of MnAs micro and nano-ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Steren, L. B.; Tortarolo, M. [Centro Atómico Constituyentes CNEA, 1650 San Martín (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas, C1033AAJ Buenos Aires (Argentina); Fernandez Baldis, F.; Sirena, M. [Consejo Nacional de Investigaciones Científicas y Técnicas, C1033AAJ Buenos Aires (Argentina); Centro Atómico Bariloche and Instituto Balseiro, CNEA, 8400 S. C. de Bariloche (Argentina); Sacchi, M.; Eddrief, M. [Sorbonne Universités, UPMC Univ. Paris 06, UMR 7588, INSP, 4 place Jussieu, F-75005 Paris (France); CNRS, UMR 7588, Institut des Nanosciences de Paris, 4 place Jussieu, F-75005 Paris (France); Etgens, V. H. [Fédération Lavoisier Franklin, UVSQ, 78035 Versailles Cedex (France); Santos, B.; Mentes, T. O.; Locatelli, A. [Elettra-Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Trieste (Italy)

    2016-09-07

    The micromagnetic domain structure of MnAs films gave place to an intense research activity in the last few years due to its potential application in magneto-electronic devices such as domain-wall track memories and logic circuits. These applications require a full knowledge of miniaturization effects on the magnetic properties of the material. In this work, X-ray photoemission electron microscopy has been used for imaging magnetic domains in lithographically fabricated MnAs ribbons, addressing the dependence of the domain configuration on film thickness and ribbon width. Our experiments show a transition from head-on to regular stripe domains below a critical width/thickness ratio w{sub c} ≈ 6. Micromagnetic simulations suggest that this transition is correlated to the magnetic structure of the surface plane. Depending on the ribbon width and thickness, the magnetic configuration is shown to evolve from flux-closure domain structure to a state of almost homogeneous magnetization, observed for narrower ribbons. The evolution of the domain structure, magnetic fraction, and magnetization with temperature has been studied across the ferromagnetic/paramagnetic transition. Our experiments show that the magnetic configuration in ribbons exhibits higher stability to temperature variations than in as-cast films.

  14. Combined effects of vertical and lateral confinement on the magnetic properties of MnAs micro and nano-ribbons

    International Nuclear Information System (INIS)

    Steren, L. B.; Tortarolo, M.; Fernandez Baldis, F.; Sirena, M.; Sacchi, M.; Eddrief, M.; Etgens, V. H.; Santos, B.; Mentes, T. O.; Locatelli, A.

    2016-01-01

    The micromagnetic domain structure of MnAs films gave place to an intense research activity in the last few years due to its potential application in magneto-electronic devices such as domain-wall track memories and logic circuits. These applications require a full knowledge of miniaturization effects on the magnetic properties of the material. In this work, X-ray photoemission electron microscopy has been used for imaging magnetic domains in lithographically fabricated MnAs ribbons, addressing the dependence of the domain configuration on film thickness and ribbon width. Our experiments show a transition from head-on to regular stripe domains below a critical width/thickness ratio w_c ≈ 6. Micromagnetic simulations suggest that this transition is correlated to the magnetic structure of the surface plane. Depending on the ribbon width and thickness, the magnetic configuration is shown to evolve from flux-closure domain structure to a state of almost homogeneous magnetization, observed for narrower ribbons. The evolution of the domain structure, magnetic fraction, and magnetization with temperature has been studied across the ferromagnetic/paramagnetic transition. Our experiments show that the magnetic configuration in ribbons exhibits higher stability to temperature variations than in as-cast films.

  15. Hydrodynamic perception in true seals (Phocidae) and eared seals (Otariidae).

    Science.gov (United States)

    Hanke, Wolf; Wieskotten, Sven; Marshall, Christopher; Dehnhardt, Guido

    2013-06-01

    Pinnipeds, that is true seals (Phocidae), eared seals (Otariidae), and walruses (Odobenidae), possess highly developed vibrissal systems for mechanoreception. They can use their vibrissae to detect and discriminate objects by direct touch. At least in Phocidae and Otariidae, the vibrissae can also be used to detect and analyse water movements. Here, we review what is known about this ability, known as hydrodynamic perception, in pinnipeds. Hydrodynamic perception in pinnipeds developed convergently to the hydrodynamic perception with the lateral line system in fish and the sensory hairs in crustaceans. So far two species of pinnipeds, the harbour seal (Phoca vitulina) representing the Phocidae and the California sea lion (Zalophus californianus) representing the Otariidae, have been studied for their ability to detect local water movements (dipole stimuli) and to follow hydrodynamic trails, that is the water movements left behind by objects that have passed by at an earlier point in time. Both species are highly sensitive to dipole stimuli and can follow hydrodynamic trails accurately. In the individuals tested, California sea lions were clearly more sensitive to dipole stimuli than harbour seals, and harbour seals showed a superior trail following ability as compared to California sea lions. Harbour seals have also been shown to derive additional information from hydrodynamic trails, such as motion direction, size and shape of the object that caused the trail (California sea lions have not yet been tested). The peculiar undulated shape of the harbour seals' vibrissae appears to play a crucial role in trail following, as it suppresses self-generated noise while the animal is swimming.

  16. Shaft seal assembly and method

    Science.gov (United States)

    Keba, John E. (Inventor)

    2007-01-01

    A pressure-actuated shaft seal assembly and associated method for controlling the flow of fluid adjacent a rotatable shaft are provided. The seal assembly includes one or more seal members that can be adjusted between open and closed positions, for example, according to the rotational speed of the shaft. For example, the seal member can be configured to be adjusted according to a radial pressure differential in a fluid that varies with the rotational speed of the shaft. In addition, in the closed position, each seal member can contact a rotatable member connected to the shaft to form a seal with the rotatable member and prevent fluid from flowing through the assembly. Thus, the seal can be closed at low speeds of operation and opened at high speeds of operation, thereby reducing the heat and wear in the seal assembly while maintaining a sufficient seal during all speeds of operation.

  17. Rotary shaft seal

    International Nuclear Information System (INIS)

    Langebrake, C.O.

    1984-01-01

    The invention is a novel rotary shaft seal assembly which provides positive-contact sealing when the shaft is not rotated and which operates with its sealing surfaces separated by a film of compressed ambient gas whose width is independent of the speed of shaft rotation. In a preferred embodiment, the assembly includes a disc affixed to the shaft for rotation therewith. Axially movable, non-rotatable plates respectively supported by sealing bellows are positioned on either side of the disc to be in sealing engagement therewith. Each plate carries piezoelectric transducer elements which are electrically energized at startup to produce films of compressed ambient gas between the confronting surfaces of the plates and the disc. Following shutdown of the shaft, the transducer elements are de-energized. A control circuit responds to incipient rubbing between the plate and either disc by altering the electrical input to the transducer elements to eliminate rubbing

  18. Seal containment system

    International Nuclear Information System (INIS)

    Kugler, R.W.; Gerkey, K.S.; Kasner, W.H.

    1978-01-01

    An automated system for transporting nuclear fuel elements between fuel element assembly stations without contaminating the area outside the sealed assembly stations is described. The system comprises a plurality of assembly stations connected together by an elongated horizontal sealing mechanism and an automatic transport mechanism for transporting a nuclear fuel element in a horizontal attitude between the assembly stations while the open end of the fuel element extends through the sealing mechanism into the assembly station enclosure. The sealing mechanism allows the fuel element to be advanced by the transport mechanism while limiting the escape of radioactive particles from within the assembly station enclosure. 4 claims, 6 figures

  19. Core disruptive accident margin seal

    International Nuclear Information System (INIS)

    Golden, M.P.

    1979-01-01

    An apparatus for sealing the annulus defined within a substantially cylindrical rotatable riser assembly and plug combination of a nuclear reactor closure head is described. The apparatus comprises an inflatable sealing mechanism disposed in one portion of the riser assembly near the annulus such that upon inflation the sealing mechanism is radially actuated against the other portion of the riser assembly thereby sealing the annulus. The apparatus further comprises a connecting mechanism which places one end of the sealing mechanism in fluid communication with the reactor cover gas so that overpressurization of the reactor cover gas will increase the radial actuation of the sealing mechanism thus enhancing sealing of the annulus

  20. Improved circumferential shaft seal

    Science.gov (United States)

    Ludwig, L. P.; Strom, T. N.

    1974-01-01

    Comparative tests of modified and unmodified carbon ring seals showed that addition of helical grooves to conventional segmented carbon ring seals reduced leakage significantly. Modified seal was insensitive to shaft runout and to flooding by lubricant.

  1. Seals for sealing a pressure vessel such as a nuclear reactor vessel or the like

    International Nuclear Information System (INIS)

    Bruns, H.J.; Huelsermann, K.H.

    1975-01-01

    A description is given of seals for sealing a pressure vessel such as a nuclear reactor vessel, steam boiler vessel, or any other vessel which is desirably sealed against pressure of the type including a housing and a housing closure that present opposed vertical sealing surfaces which define the sides of a channel. The seals of the present invention comprise at least one sealing member disposed in the channel, having at least one stop face, a base portion and two shank portions extending from the base portion to form a groove-like recess. The shank portions are provided with sealing surfaces arranged to mate with the opposed vertical pressure vessel sealing surfaces. A shank-spreading wedge element also disposed in the channel has at least one stop face and is engaged in the groove-like recess with the sealing member and wedge element stop face adjacent to each other

  2. Influence of Mn incorporation for Ni on the magnetocaloric properties of rapidly solidified off-stoichiometric NiMnGa ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Dey, Sushmita; Singh, Satnam; Roy, R.K.; Ghosh, M.; Mitra, A.; Panda, A.K., E-mail: akpanda@nmlindia.org

    2016-01-01

    The present investigation addresses the magnetocaloric behaviour in a series of Ni{sub 77−x}Mn{sub x}Ga{sub 23} (x=23, 24, 25, 27 and 29) rapidly solidified alloys prepared in the form of ribbons by melt spinning technique. The approach of the study is to identify the off-stoichiometric composition wherein room temperature magneto-structural transformation is achieved. The alloy chemistry was tailored through Mn incorporation for Ni such that the magnetic and structural transitions were at close proximity to achieve highest entropy value of ΔS equal to 8.51 J Kg{sup −1} K{sup −1} for #Mn{sub 24} ribbon measured at an applied field of 3 T. When such transitions are more staggered as in #Mn{sub 29} the entropy value of ribbon reduced to as low as 1.61 J Kg{sup −1} K{sup −1}. Near room temperature transformations in #Mn{sub 24} ribbon have been observed through calorimetric and thermomagnetic evaluation. Reverse martensitic transformation (martensite→autstenite) temperature indicates not only distinct change in the saturation flux density but also an inter-martensitic phase. Microstructural analysis of #Mn{sub 24} alloy ribbon revealed structural ordering with the existence of plate morphology evidenced for martensitic phase. - Highlights: • Magnetocaloric effect in a series of melt spun NiMnGa ribbon is addressed. • The alloy series revealed austenitic state as well as its presence with martensite. • The morphology of the ribbons has been shown and discussed through phase analysis. • Influence of magnetising field on entropy and relative cooling power is discussed. • Influence of intermartensitic state on magnetization plots have also been shown.

  3. Seals in nuclear reactors

    International Nuclear Information System (INIS)

    1979-01-01

    The seals described are for use in a nuclear reactor where there are fuel assemblies in a vessel, an inlet and an outlet for circulating a coolant in heat transfer relationship with the fuel assemblies and a closure head on the vessel in a tight fluid relationship. The closure head comprises rotatable plugs which have mechanical seals disposed in the annulus around each plug while allowing free rotation of the plug when the seal is not actuated. The seal is usually an elastomer or copper. A means of actuating the seal is attached for drawing it vertically into the annulus for sealing. When the reactor coolant is liquid sodium, contact with oxygen must be avoided and argon cover gas fills the space between the bottom of the closure head and the coolant liquid level and the annuli in the closure head. (U.K.)

  4. Investigation of positive shaft seals

    Science.gov (United States)

    Pfouts, J. O.

    1970-01-01

    Welded metal bellows secondary seals prevent secondary seal leakage with a minimum number of potential leak paths. High performance seal is obtained by controlling the potentially unstable seal-face movements induced by mechanical vibrations and fluid pressure pulsations.

  5. Enhanced piezoelectricity and stretchability in energy harvesting devices fabricated from buckled PZT ribbons.

    Science.gov (United States)

    Qi, Yi; Kim, Jihoon; Nguyen, Thanh D; Lisko, Bozhena; Purohit, Prashant K; McAlpine, Michael C

    2011-03-09

    The development of a method for integrating highly efficient energy conversion materials onto soft, biocompatible substrates could yield breakthroughs in implantable or wearable energy harvesting systems. Of particular interest are devices which can conform to irregular, curved surfaces, and operate in vital environments that may involve both flexing and stretching modes. Previous studies have shown significant advances in the integration of highly efficient piezoelectric nanocrystals on flexible and bendable substrates. Yet, such inorganic nanomaterials are mechanically incompatible with the extreme elasticity of elastomeric substrates. Here, we present a novel strategy for overcoming these limitations, by generating wavy piezoelectric ribbons on silicone rubber. Our results show that the amplitudes in the waves accommodate order-of-magnitude increases in maximum tensile strain without fracture. Further, local probing of the buckled ribbons reveals an enhancement in the piezoelectric effect of up to 70%, thus representing the highest reported piezoelectric response on a stretchable medium. These results allow for the integration of energy conversion devices which operate in stretching mode via reversible deformations in the wavy/buckled ribbons.

  6. Forming three-dimensional closed shapes from two-dimensional soft ribbons by controlled buckling

    Science.gov (United States)

    Aoki, Michio; Juang, Jia-Yang

    2018-02-01

    Conventional manufacturing techniques-moulding, machining and casting-exist to produce three-dimensional (3D) shapes. However, these industrial processes are typically geared for mass production and are not directly applicable to residential settings, where inexpensive and versatile tools are desirable. Moreover, those techniques are, in general, not adequate to process soft elastic materials. Here, we introduce a new concept of forming 3D closed hollow shapes from two-dimensional (2D) elastic ribbons by controlled buckling. We numerically and experimentally characterize how the profile and thickness of the ribbon determine its buckled shape. We find a 2D master profile with which various elliptical 3D shapes can be formed. More complex natural and artificial hollow shapes, such as strawberry, hourglass and wheel, can also be achieved via strategic design and pattern engraving on the ribbons. The nonlinear response of the post-buckling regime is rationalized through finite-element analysis, which shows good quantitative agreement with experiments. This robust fabrication should complement conventional techniques and provide a rich arena for future studies on the mechanics and new applications of elastic hollow structures.

  7. Continuous improvement of pump seals

    International Nuclear Information System (INIS)

    Wong, W.; Eyvindson, A.; Rhodes, D.B.

    2003-01-01

    Pump seal reliability continues to be an area needing improvement and ongoing vigilance. Methods have been developed for identifying and assessing factors relating to seal performance, selecting the most relevant ones for a specific station, and then focusing on the most significant aspects and how to improve. Discussion invariably addresses maintenance practices, seal design, monitoring capabilities, operating conditions, transients, and pump and motor design. Success in reliability improvement requires ongoing dialogue among the station operators, pump manufacturers and seal designers. AECL CAN-seals lead the nuclear industry in reliability and seal life. They effectively save operators millions of dollars in outage time and person-rem. This paper describes some of the significant developments in AECL's ongoing program in seal R and D, as well as recent new installations following the most demanding seal qualification programs to date. (author)

  8. Ferrules seals

    Science.gov (United States)

    Smith, J.L.

    1984-07-10

    A device is provided for sealing an inner tube and an outer tube without excessively deforming the tubes. The device includes two ferrules which cooperate to form a vacuum-tight seal between the inner tube and outer tube and having mating surfaces such that overtightening is not possible. 3 figs.

  9. A magnetic fluid seal for rotary blood pumps: effects of seal structure on long-term performance in liquid.

    Science.gov (United States)

    Mitamura, Yoshinori; Takahashi, Sayaka; Amari, Shuichi; Okamoto, Eiji; Murabayashi, Shun; Nishimura, Ikuya

    2011-03-01

    A magnetic fluid (MF) seal enables mechanical contact-free rotation of the shaft and hence has excellent durability. The performance of an MF seal, however, has been reported to decrease in liquids. We developed an MF seal that has a "shield" mechanism, and a new MF with a higher magnetization of 47.9 kA/m. The sealing performance of the MF seal installed in a rotary blood pump was studied. Three types of MF seals were used. Seal A was a conventional seal without a shield. Seal B had the same structure as that of Seal A, but the seal was installed at 1 mm below liquid level. Seal C was a seal with a shield and the MF was set at 1 mm below liquid level. Seal A failed after 6 and 11 days. Seal B showed better results (20 and 73 days). Seal C showed long-term durability (217 and 275 days). The reason for different results in different seal structures was considered to be different flow conditions near the magnetic fluid. Fluid dynamics near the MF in the pump were analyzed using computational fluid dynamics (CFD) software. We have developed an MF seal with a shield that works in liquid for >275 days. The MF seal is promising as a shaft seal for rotary blood pumps.

  10. Borehole sealing method and apparatus

    International Nuclear Information System (INIS)

    Hartley, J.N.; Jansen, G. Jr.

    1977-01-01

    A method and apparatus is described for sealing boreholes in the earth. The borehole is blocked at the sealing level, and a sealing apparatus capable of melting rock and earth is positioned in the borehole just above seal level. The apparatus is heated to rock-melting temperature and powdered rock or other sealing material is transported down the borehole to the apparatus where it is melted, pooling on the mechanical block and allowed to cool and solidify, sealing the hole. Any length of the borehole can be sealed by slowly raising the apparatus in the borehole while continuously supplying powdered rock to the apparatus to be melted and added to the top of the column of molten and cooling rock, forming a continuous borehole seal. The sealing apparatus consists of a heater capable of melting rock, including means for supplying power to the heater, means for transporting powdered rock down the borehole to the heater, means for cooling the apparatus and means for positioning the apparatus in the borehole. 5 claims, 1 figure

  11. Fish Marketing of Ribbon Fish (Trichiurus sp.) in Nusantara Fishing Port (NFP)at Palabuhanratu, West Java

    Science.gov (United States)

    Bambang, Azis Nur

    2018-02-01

    The objective of this research is to study the marketing process of ribbon fish (Trichiurus sp.), including the marketing margin, marketing agencies, traders and marketing channels The research was carried out for 3 mo in Nusantara Fishing Port (NFP), Palabuhanratu, Sukabumi, West Java. A case study was used in this research. A purposive sampling method was used to collect data from 55 respondents of fish marketing, consisting of fishermen, agents, traders, and retailers, who were involved in the marketing of ribbon fish in NFP Palabuhanratu. The result of the research showed that ribbon fish production in Palabuhanratu fluctuated from year to year. There are two types of ribbon fish marketing, i.e. type one is from fishermen to retailers, and type two is indirect marketing from fisherman to consumers through intermediate traders (exporters). The greatest marketing margin was obtained from the first type, while the smallest marketing margin was obtained from type two. The form of the market was considered to be oligopsony market. Fisherman's share is greatest in the collectors and the smallest share is on retailers. Marketing process in traders is efficient due to its lowest margin and highest fisherman's share.

  12. TECHNOLOGY ROADMAPPING FOR IAEA SEALS.

    Energy Technology Data Exchange (ETDEWEB)

    HOFFHEINS,B.; ANNESE,C.; GOODMAN,M.; OCONNOR,W.; GUSHUE,S.; PEPPER,S.

    2003-07-13

    In the fall of 2002, the U.S. Support Program (USSP) initiated an effort to define a strategy or ''roadmap'' for future seals technologies and to develop a generalized process for planning safeguards equipment development, which includes seals and other safeguards equipment. The underlying objectives of the USSP include becoming more proactive than reactive in addressing safeguards equipment needs, helping the IAEA to maintain an inventory of cost-effective, reliable, and effective safeguards equipment, establishing a long-term planning horizon, and securing IAEA ownership in the process of effective requirements definition and timely transitioning of new or improved systems for IAEA use. At an initial workshop, seals, their functions, performance issues, and future embodiments were discussed in the following order: adhesive seals, metal seals, passive and active loop seals, ultrasonic seals, tamper indicating enclosures (including sample containers, equipment enclosures, and conduits). Suggested improvements to these technologies focused largely on a few themes: (1) The seals must be applied quickly, easily, and correctly; (2) Seals and their associated equipment should not unduly add bulk or weight to the inspectors load; (3) Rapid, in-situ verifiability of seals is desirable; and (4) Seal systems for high risk or high value applications should have two-way, remote communications. Based upon these observations and other insights, the participants constructed a skeletal approach for seals technology planning. The process begins with a top-level review of the fundamental safeguards requirements and extraction of required system features, which is followed by analysis of suitable technologies and identification of technology gaps, and finally by development of a planning schedule for system improvements and new technology integration. Development of a comprehensive procedure will require the partnership and participation of the IAEA. The

  13. Closure and Sealing Design Calculation

    International Nuclear Information System (INIS)

    T. Lahnalampi; J. Case

    2005-01-01

    The purpose of the ''Closure and Sealing Design Calculation'' is to illustrate closure and sealing methods for sealing shafts, ramps, and identify boreholes that require sealing in order to limit the potential of water infiltration. In addition, this calculation will provide a description of the magma that can reduce the consequences of an igneous event intersecting the repository. This calculation will also include a listing of the project requirements related to closure and sealing. The scope of this calculation is to: summarize applicable project requirements and codes relating to backfilling nonemplacement openings, removal of uncommitted materials from the subsurface, installation of drip shields, and erecting monuments; compile an inventory of boreholes that are found in the area of the subsurface repository; describe the magma bulkhead feature and location; and include figures for the proposed shaft and ramp seals. The objective of this calculation is to: categorize the boreholes for sealing by depth and proximity to the subsurface repository; develop drawing figures which show the location and geometry for the magma bulkhead; include the shaft seal figures and a proposed construction sequence; and include the ramp seal figure and a proposed construction sequence. The intent of this closure and sealing calculation is to support the License Application by providing a description of the closure and sealing methods for the Safety Analysis Report. The closure and sealing calculation will also provide input for Post Closure Activities by describing the location of the magma bulkhead. This calculation is limited to describing the final configuration of the sealing and backfill systems for the underground area. The methods and procedures used to place the backfill and remove uncommitted materials (such as concrete) from the repository and detailed design of the magma bulkhead will be the subject of separate analyses or calculations. Post-closure monitoring will not

  14. Sealing properties of mechanical seals for an axial flow blood pump.

    Science.gov (United States)

    Tomioka, J; Mori, T; Yamazaki, K; Koyanagi, H

    1999-08-01

    A miniature intraventricular axial flow blood pump for left ventricular support is under development. One of the key technologies required for such pumps is sealing of the motor shaft. In this study, to prevent blood backflow into the motor side, mechanical seals were developed and their sealing properties investigated. In the experimental apparatus, the mechanical seal separated the bovine blood on the chamber side from the cooling water on the motor side. A leakage of the blood was measured by inductively coupled plasma (ICP) light emission analysis. The rate of hemolysis was measured by the cyanmethemoglobin method. Frictional torque acting on the shaft was measured by a torque transducer. In the experiments, the rotational speed of the shaft was changed from 1,000 to 10,000 rpm, and the contact force of the seal faces was changed from 1.96 to 4.31 N. To estimate lubrication regimes, the Stribeck curve, a diagram of the coefficient of friction against the bearing characteristic G number, was drawn. The results of the experiments showed that both the leakage of blood and the rate of hemolysis were very small. The friction loss was also very small. The mechanical seal was operated in various lubrication regimes, from a fluid lubrication regime to a mixed lubrication regime.

  15. Investigating the sealing capacity of a seal system in rock salt (DOPAS project)

    Energy Technology Data Exchange (ETDEWEB)

    Jantschik, Kyra; Moog, Helge C.; Czaikowski, Oliver; Wieczorek, Klaus [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, Braunschweig (Germany)

    2016-11-15

    This paper describes research and development work on plugging and sealing repositories, an issue of fundamental importance for the rock salt option which represents one of the three European repository options, besides the clay rock and the crystalline rock options. The programme aims at providing experimental data needed for the theoretical analysis of the long-term sealing capacity of concrete- based sealing materials. In order to demonstrate hydro-mechanical material stability under representative load scenarios, a comprehensive laboratory testing programme is carried out. This comprises investigation of the sealing capacity of the combined seal system and impact of the so-called excavation-damaged zones (EDZ) as well as investigation of the hydro-chemical long-term stability of the seal in contact with different brines under diffusive and advective conditions. This paper presents experimental approaches and preliminary results from laboratory investigations on salt concrete and combined systems as obtained to date.

  16. Regenerator cross arm seal assembly

    Science.gov (United States)

    Jackman, Anthony V.

    1988-01-01

    A seal assembly for disposition between a cross arm on a gas turbine engine block and a regenerator disc, the seal assembly including a platform coextensive with the cross arm, a seal and wear layer sealingly and slidingly engaging the regenerator disc, a porous and compliant support layer between the platform and the seal and wear layer porous enough to permit flow of cooling air therethrough and compliant to accommodate relative thermal growth and distortion, a dike between the seal and wear layer and the platform for preventing cross flow through the support layer between engine exhaust and pressurized air passages, and air diversion passages for directing unregenerated pressurized air through the support layer to cool the seal and wear layer and then back into the flow of regenerated pressurized air.

  17. Aerial surveys of seals at Rødsand seal sanctuary and adjacent haul-out sites

    DEFF Research Database (Denmark)

    Teilmann, J.; Dietz, R.; Edren, Susi M.C.

    This report describes the preliminary results of aerial surveys at Rødsand seal sanctuary, southeast Denmark and adjacent seal haul-out sites in southwestern Baltic. The work was carried out in connection with studies of potential effects of the Nysted offshore wind farm. Rødsand seal sanctuary...... is a part of seal management area 4, and the area is believed to hold a more or less closed population with little exchange to other areas. Although the harbour seal is relatively stationary there may be movements between the haul-out sites in the area. A possible reaction to disturbance from...... the construction and operation of the wind farm may be that the seals use other haul-out sites to a higher extend....

  18. Magnetic properties of fcc (Co95Fe5)1-xAlx ribbons

    International Nuclear Information System (INIS)

    Makhlouf, Salah A.; Parker, F.T.; Benameur, T.

    1999-01-01

    Rapidly quenched (Co 95 Fe 5 ) 1-x Al x ribbons are investigated by X-ray diffraction, magnetization, and Moessbauer effect measurements. A single fcc phase is obtained for all ribbons x ≤ 10 at.%. The lattice constant increases linearly with x and is discussed in connection with magnetic moment. The influence of Al substitution on both magnetization and Fe-atom hyperfine field (H) is studied. At 296 K, the magnetization decreases linearly while H drops nonlinearly as x increases. Al substitution leads to substantial differences in iron hyperfine fields in bcc and fcc systems. Fe moment is perturbed differently by Al substitution in fcc (Co 95 Fe 5 ) 1-x Al x and bcc Fe-Al systems

  19. Ceramic/metal seals. [refractory materials for hermetic seals for lighium-metal sulfide batteries

    Science.gov (United States)

    Bredbenner, A. M.

    1977-01-01

    Design criteria are discussed for a hermetic seal capable of withstanding the 450 C operating temperature of a lithium-metal sulfide battery system. A mechanical seal consisting of two high strength alloy metal sleeves welded or brazed to a conductor assembly and pressed onto a ceramic is described. The conductor center passes through the ceramic but is not sealed to it. The seal is effected on the outside of the taper where the tubular part is pressed down over and makes contact.

  20. Microstructure, biocorrosion and cytotoxicity evaluations of rapid solidified Mg-3Ca alloy ribbons as a biodegradable material.

    Science.gov (United States)

    Gu, X N; Li, X L; Zhou, W R; Cheng, Y; Zheng, Y F

    2010-06-01

    Rapidly solidified (RS) Mg–3Ca alloy ribbons were prepared by the melt-spinning technique at different wheel rotating speeds (15 m s(-1), 30 m s(-1) and 45 m s(-1) with the as-cast Mg–3Ca alloy ingot as a raw material. The RS45 Mg–3Ca alloy ribbon showed a much more fine grain size feature (approximately 200–500 nm) in comparison to the coarse grain size (50–100 μm)of the original as-cast Mg–3Ca alloy ingot. The corrosion electrochemical tests in simulated body fluid indicated that the corrosion rate of the as-cast Mg–3Ca alloy was strongly reduced by the RS procedure and tended to be further decreased with increasing wheel rotating speeds(1.43 mm yr(-1) for RS15, 0.94 mm yr(-1) for RS30 and 0.36 mm yr(-1) for RS45). The RS Mg–3Ca alloy ribbons showed more uniform corrosion morphology compared with the as-cast Mg–3Ca alloy after polarization. The cytotoxicity evaluation revealed that the three experimental as-spun Mg–3Ca alloy ribbon extracts did not induce toxicity to the L-929 cells,whereas the as-cast Mg–3Ca alloy ingot extract did. The L-929 cells showed more improved adhesion on the surfaces of the three as-spun Mg–3Ca alloy ribbons than that of the as-cast Mg–3Ca alloy ingot.

  1. Microstructure, biocorrosion and cytotoxicity evaluations of rapid solidified Mg-3Ca alloy ribbons as a biodegradable material

    International Nuclear Information System (INIS)

    Gu, X N; Zhou, W R; Zheng, Y F; Li, X L; Cheng, Y

    2010-01-01

    Rapidly solidified (RS) Mg-3Ca alloy ribbons were prepared by the melt-spinning technique at different wheel rotating speeds (15 m s -1 , 30 m s -1 and 45 m s -1 ) with the as-cast Mg-3Ca alloy ingot as a raw material. The RS45 Mg-3Ca alloy ribbon showed a much more fine grain size feature (approximately 200-500 nm) in comparison to the coarse grain size (50-100 μm) of the original as-cast Mg-3Ca alloy ingot. The corrosion electrochemical tests in simulated body fluid indicated that the corrosion rate of the as-cast Mg-3Ca alloy was strongly reduced by the RS procedure and tended to be further decreased with increasing wheel rotating speeds (1.43 mm yr -1 for RS15, 0.94 mm yr -1 for RS30 and 0.36 mm yr -1 for RS45). The RS Mg-3Ca alloy ribbons showed more uniform corrosion morphology compared with the as-cast Mg-3Ca alloy after polarization. The cytotoxicity evaluation revealed that the three experimental as-spun Mg-3Ca alloy ribbon extracts did not induce toxicity to the L-929 cells, whereas the as-cast Mg-3Ca alloy ingot extract did. The L-929 cells showed more improved adhesion on the surfaces of the three as-spun Mg-3Ca alloy ribbons than that of the as-cast Mg-3Ca alloy ingot.

  2. Nuclear instrumentation cable end seal

    International Nuclear Information System (INIS)

    Cannon, C.P.; Brown, D.P.

    1979-01-01

    An improved coaxial end seal for hermetically sealed nuclear instrumentation cable exhibiting an improved breakdown pulse noise characteristic under high voltage, high temperature conditions is described. A tubular insulator body has metallized interior and exterior surface portions which are braze sealed to a center conductor and an outer conductive sheath. The end surface of the insulator body which is directed toward the coaxial cable to which it is sealed has a recessed surface portion within which the braze seal material terminates

  3. Turbine interstage seal with self-balancing capability

    Science.gov (United States)

    Mills, Jacob A; Jones, Russell B; Sexton, Thomas D

    2017-09-26

    An interstage seal for a turbine of a gas turbine engine, the interstage seal having a seal carrier with an axial extending seal tooth movable with a stator of the engine, and a rotor with a seal surface that forms the interstage seal with the seal tooth, where a magnetic force produced by two magnets and a gas force produced by a gas pressure acting on the seal carrier forms a balancing force to maintain a close clearance of the seal without the seal tooth contacting the rotor seal surfaces during engine operation. In other embodiments, two pairs of magnets produce first and second magnetic forces that balance the seal in the engine.

  4. Enhanced sealing project (ESP): evolution of a full-sized concrete and bentonite shaft seal

    International Nuclear Information System (INIS)

    Dixon, D.A.; Priyanto, D.G.; Martino, J.B.; De Combarieu, M.; Johansson, R.; Korkeakoski, P.; Villagran, J.

    2012-01-01

    Document available in extended abstract form only. A full-scale shaft seal was designed and installed in the 5-m-diameter access shaft at Atomic Energy of Canada's (AECL's) Underground Research Laboratory (URL) at the point where he shaft intersects an ancient water-bearing, low-angle thrust fault in granitic rock. The seal, part of the permanent closure of the URL, consists of a 6-m-thick bentonite-based component sandwiched between 3-m-thick upper and lower, 3-m-thick concrete components. The bentonite-based component spans the fracture zone and extends approximately 1 m beyond the maximum identified extent of the fracture. This design was adopted in order to limit water from the deeper, saline regions mixing with the fresher, near-surface groundwater regime. The concrete components provide the mechanical confinement and an in situ compacted 40/60 mixture of bentonite clay and quartz sand provides the sealing component. Construction of the shaft seal was done as part of Canada's Nuclear Legacies Liability Program. However, monitoring the seal evolution was not part of the decommissioning program's mandate. In addition to accomplishing the permanent closure of the URL, this seal's construction provides a unique opportunity to instrument and monitor the evolution of a full-scale shaft seal as well as the recovery of the regional groundwater regime as the facility passively floods above the seal. A jointly funded monitoring project was developed by NWMO (Canada), SKB (Sweden), Posiva (Finland) and ANDRA (France) and since mid 2009 the thermal, hydraulic and mechanical evolution of the seal has been constantly monitored. The evolution of the type of seal being monitored in the ESP is of relevance to repository closure planning, gaining confidence in the functionality of shaft seals. Although constructed in a crystalline rock medium, the results of the ESP are expected to be relevant to the performance of seals in a variety of host rock types. The shaft seal has been

  5. Sealing a conduit end

    International Nuclear Information System (INIS)

    Mentz, R.M.

    1993-01-01

    An apparatus for sealing or blocking conduits, such as the primary nozzles of a nuclear steam generator is described. It includes an annular bracket sealingly attached to the open end of the nozzle, the bracket having a plurality of threaded holes therein. Mounted atop the bracket is a generally circular nozzle dam for covering the opening. Interposed between the nozzle dam and the bracket is an extrusion-resistant seal member having a plurality of apertures therethrough for receiving each bolt. The seal member is configured to resist extrusion by having laminated layers of differing hardnesses, so that the seal member will not laterally extrude away from each bolt in a manner that enlarges the aperture surrounding each bolt as the nozzle dam is bolted to the bracket. (author)

  6. Concurrent gradients of ribbon volume and AMPA-receptor patch volume in cochlear afferent synapses on gerbil inner hair cells.

    Science.gov (United States)

    Zhang, Lichun; Engler, Sina; Koepcke, Lena; Steenken, Friederike; Köppl, Christine

    2018-07-01

    The Mongolian gerbil is a classic animal model for age-related hearing loss. As a prerequisite for studying age-related changes, we characterized cochlear afferent synaptic morphology in young adult gerbils, using immunolabeling and quantitative analysis of confocal microscopic images. Cochlear wholemounts were triple-labeled with a hair-cell marker, a marker of presynaptic ribbons, and a marker of postsynaptic AMPA-type glutamate receptors. Seven cochlear positions covering an equivalent frequency range from 0.5 - 32 kHz were evaluated. The spatial positions of synapses were determined in a coordinate system with reference to their individual inner hair cell. Synapse numbers confirmed previous reports for gerbils (on average, 20-22 afferents per inner hair cell). The volumes of presynaptic ribbons and postsynaptic glutamate receptor patches were positively correlated: larger ribbons associated with larger receptor patches and smaller ribbons with smaller patches. Furthermore, the volumes of both presynaptic ribbons and postsynaptic receptor patches co-varied along the modiolar-pillar and the longitudinal axes of their hair cell. The gradients in ribbon volume are consistent with previous findings in cat, guinea pig, mouse and rat and further support a role in differentiating the physiological properties of type I afferents. However, the positive correlation between the volumes of pre- and postsynaptic elements in the gerbil is different to the opposing gradients found in the mouse, suggesting species-specific differences in the postsynaptic AMPA receptors that are unrelated to the fundamental classes of type I afferents. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Hermetic Seal Leak Detection Apparatus

    Science.gov (United States)

    Kelley, Anthony R. (Inventor)

    2013-01-01

    The present invention is a hermetic seal leak detection apparatus, which can be used to test for hermetic seal leaks in instruments and containers. A vacuum tight chamber is created around the unit being tested to minimize gas space outside of the hermetic seal. A vacuum inducing device is then used to increase the gas chamber volume inside the device, so that a slight vacuum is pulled on the unit being tested. The pressure in the unit being tested will stabilize. If the stabilized pressure reads close to a known good seal calibration, there is not a leak in the seal. If the stabilized pressure reads closer to a known bad seal calibration value, there is a leak in the seal. The speed of the plunger can be varied and by evaluating the resulting pressure change rates and final values, the leak rate/size can be accurately calculated.

  8. Fiscal 1976 Sunshine Project result report. R and D on photovoltaic power generation system (R and D on Si ribbon crystal vertical pulling method); 1976 nendo taiyoko hatsuden system no kenkyu kaihatsu seika hokokusho. Silicon tatehiki ribbon kessho no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1977-03-31

    This report describes the fiscal 1976 research result on Si ribbon crystal vertical pulling method for photovoltaic power generation systems. The equipment for simultaneous growth of 3 ribbon crystals was designed and prepared in consideration of capillary die arrangement, vertical pulling method and control method of temperature profiles on the die surface. The temperature profiles on the die surface were controlled by subheaters for 3 parts of each capillary die which were divided longitudinally. Ribbon crystals grew up to 5mm simultaneously through both end dies. By cooling a part of crystal, fast pulling is probably possible. Study was made on the correlation between various crystal defects of Si ribbon crystals and cell characteristics, and in particular, basic characteristics of SiC deposited particles by SEM observation to reduce their impacts. Possibility of simultaneous vertical pulling of crystals was verified by using a capillary carbon die for multi-pulling. Although crystals grew by eutectic reaction under saturated dissolution of carbon, crystals with no transition were obtained. An SiC-coated die was excellent rather than carbon one. (NEDO)

  9. Reusable, tamper-indicating seal

    International Nuclear Information System (INIS)

    Ryan, M.J.

    1978-01-01

    A reusable, tamper-indicating seal is comprised of a drum confined within a fixed body and rotatable in one direction therewithin, the top of the drum constituting a tray carrying a large number of small balls of several different colors. The fixed body contains parallel holes for looping a seal wire therethrough. The base of the drums carries cams adapted to coact with cam followers to lock the wire within the seal at one angular position of the drum. A channel in the fixed body, visible from outside the seal, adjacent the tray constitutes a segregated location for a small plurality of the colored balls. A spring in the tray forces colored balls into the segregated location at one angular position of the drum, further rotation securing the balls in position and the wires in the seal. A wedge-shaped plough removes the balls from the segregated location, at a different angular position of the drum, the wire being unlocked at the same postion. A new pattern of colored balls will appear in the segregated location when the seal is relocked

  10. Double angle seal forming lubricant film

    Science.gov (United States)

    Ernst, William D.

    1984-01-01

    A lubricated piston rod seal which inhibits gas leaking from a high pressure chamber on one side of the seal to a low pressure chamber on the other side of the seal. A liquid is supplied to the surface of the piston rod on the low pressure side of the seal. This liquid acts as lubricant for the seal and provides cooling for the rod. The seal, which can be a plastic, elastomer or other material with low elastic modulus, is designed to positively pump lubricant through the piston rod/seal interface in both directions when the piston rod is reciprocating. The capacity of the seal to pump lubricant from the low pressure side to the high pressure side is less than its capacity to pump lubricant from the high pressure side to the low pressure side which ensures that there is zero net flow of lubricant to the high pressure side of the seal. The film of lubricant between the seal and the rod minimizes any sliding contact and prevents the leakage of gas. Under static conditions gas leakage is prevented by direct contact between the seal and the rod.

  11. Oxidation behaviour of ribbon shape carbon fibers and their composites

    International Nuclear Information System (INIS)

    Manocha, L.M.; Warrier, Ashish; Manocha, S.; Edie, D.D.; Ogale, A.A.

    2006-01-01

    Carbon fibers, though important constituent as reinforcements for high performance carbon/carbon composites, are shadowed by their oxidation in air at temperatures beginning 450 deg. C. Owing to tailorable properties of carbon fibers, efforts are underway to explore structural modification possibilities to improve the oxidation resistance of the fibers and their composites. The pitch based ribbon shape carbon fibers are found to have highly preferential oriented graphitic structure resulting in high mechanical properties and thermal conductivity. In the present work oxidation behaviour of ribbon shape carbon fibers and their composites heat treated to 1000-2700 deg. C has been studied. SEM examination of these composites exhibits development of graphitic texture and ordering within the fibers with increase in heat treatment temperature. Oxidation studies made by thermogravimetric analysis in air show that matrix has faster rate of oxidation and in the initial stages the matrix gets oxidized at faster rate with slower rate of oxidation of the fibers depending on processing conditions of fibers and composites

  12. Shaft and tunnel sealing considerations

    International Nuclear Information System (INIS)

    Kelsall, P.C.; Shukla, D.K.

    1980-01-01

    Much of the emphasis of previous repository sealing research has been placed on plugging small diameter boreholes. It is increasingly evident that equal emphasis should now be given to shafts and tunnels which constitute more significant pathways between a repository and the biosphere. The paper discusses differences in requirements for sealing shafts and tunnels as compared with boreholes and the implications for seal design. Consideration is given to a design approach for shaft and tunnel seals based on a multiple component design concept, taking into account the requirements for retrievability of the waste. A work plan is developed for the future studies required to advance shaft and tunnel sealing technology to a level comparable with the existing technology for borehole sealing

  13. Rotatable seal assembly

    International Nuclear Information System (INIS)

    Garibaldi, J.L.; Logan, C.M.

    1982-01-01

    An assembly is provided for rotatably supporting a rotor on a stator so that vacuum chambers in the rotor and stator remain in communication while the chambers are sealed from ambient air, which enables the use of a ball bearing or the like to support most of the weight of the rotor. The apparatus includes a seal device mounted on the rotor to rotate therewith, but shiftable in position on the rotor while being sealed to the rotor as by an oring. The seal device has a flat face that is biased towards a flat face on the stator, and pressurized air is pumped between the faces to prevent contact between them while spacing them a small distance apart to avoid the inflow of large amounts of air between the faces and into the vacuum chambers

  14. Recent advances in magnetic liquid sealing

    International Nuclear Information System (INIS)

    Raj, K.; Stahl, P.; Bottenberg, W.; True, D.; Martis, G.; Zook, C.

    1979-01-01

    In this paper recent work in design and testing of two special magnetic liquid seals extending the state-of-the-art of ferrofluidic sealing is discussed. These custom seals are a moving belt edge seal and an exclusion seal. The first seal provides a hermetic barrier to solid particulates expected to be present in enclosed nuclear environments. The second seal is used on a magnetic disk drive spindle and reduces the particulate contaminants in the memory disk pack area by up to three orders of magnitude. In addition, bearing life in the spindle is found to be doubled due to reduction of operating temperature. The fundamentals of magnetic fluid sealing are presented in terms of magnetic circuit design and physical properties of ferrofluids

  15. Seal Related Development Activities at EG/G

    Science.gov (United States)

    Greiner, Harold F.

    1991-01-01

    Seal related development activities including modeling, analysis, and performance testing are described for several current seal related projects. Among the current seal related projects are the following: high pressure gas sealing systems for turbomachinery; brush seals for gas path sealing in gas turbines; and tribological material evaluation for wear surfaces in sealing systems.

  16. Plasma immersion ion implantation of boron for ribbon silicon solar cells

    Directory of Open Access Journals (Sweden)

    Derbouz K.

    2013-09-01

    Full Text Available In this work, we report for the first time on the solar cell fabrication on n-type silicon RST (for Ribbon on Sacrificial Template using plasma immersion ion implantation. The experiments were also carried out on FZ silicon as a reference. Boron was implanted at energies from 10 to 15 kV and doses from 1015 to 1016 cm-2, then activated by a thermal annealing in a conventional furnace at 900 and 950 °C for 30 min. The n+ region acting as a back surface field was achieved by phosphorus spin-coating. The frontside boron emitter was passivated either by applying a 10 nm deposited SiOX plasma-enhanced chemical vapor deposition (PECVD or with a 10 nm grown thermal oxide. The anti-reflection coating layer formed a 60 nm thick SiNX layer. We show that energies less than 15 kV and doses around 5 × 1015 cm-2 are appropriate to achieve open circuit voltage higher than 590 mV and efficiency around 16.7% on FZ-Si. The photovoltaic performances on ribbon silicon are so far limited by the bulk quality of the material and by the quality of the junction through the presence of silicon carbide precipitates at the surface. Nevertheless, we demonstrate that plasma immersion ion implantation is very promising for solar cell fabrication on ultrathin silicon wafers such as ribbons.

  17. Magneto-Impedance behavior of Co-Fe-Nb-Si-B-based ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Partha; Mohanta, O.; Pal, S.K.; Panda, A.K. [National Metallurgical Laboratory, Council of Scientific and Industrial Research, Jamshedpur 831007 (India); Mitra, A., E-mail: amitra@nmlindia.or [National Metallurgical Laboratory, Council of Scientific and Industrial Research, Jamshedpur 831007 (India)

    2010-04-15

    The giant magneto-impedance of melt spun Co{sub x}Fe{sub 72-x}Nb{sub 4}Si{sub 4}B{sub 20}(x=10, 20, 36, 50) amorphous and nanostructured ribbons have been investigated. Alloys have been optimized at the driving current amplitude, frequency and found that amorphous ribbon of nominal composition of Co{sub 36}Fe{sub 36}Nb{sub 4}Si{sub 4}B{sub 20} shown maximum GMI ratio of 13%. The behaviour of the driving current amplitude on the GMI behaviour was studied and the sample was optimized for driving current amplitude, I{sub ac}=10 mA. The frequency dependence of the GMI behaviour was studied for the ribbon sample Co{sub 36}Fe{sub 36}Nb{sub 4}Si{sub 4}B{sub 20} at frequency in the range of 100 kHz-1.2 MHz of the optimized driving current amplitude and it was found that the sample showed the maximum GMI behaviour at f=700 kHz. The optimized samples were Joule heated at the current density J=0-35 A/m{sup 2} for a period of 1 min. The GMI ratio initially increased then progressively deteriorated with J, but after a certain range it shows up to 16% of improvement in the magneto-impedance value due the increase of nanocrystalline volume fraction. The asymmetry in the GMI profile was observed for the sample Joule heated at J=1-5 A/m{sup 2} for 1 min.

  18. Effect of annealing treatment on soft magnetic properties of Fe-6.5 wt% Si wide ribbons

    International Nuclear Information System (INIS)

    Roy, R.K.; Panda, A.K.; Ghosh, M.; Mitra, A.; Ghosh, R.N.

    2009-01-01

    The 25 mm wide ribbons of Fe-6.5 wt% Si alloy have been developed by melt spinning technique, showing sufficient ductility and white silver appearance. Two magnetic transitions take place at 676 and 760 deg. C due to the formation of B2 ordered phase and A2 disordered paramagnetic phase, respectively. The saturation magnetization of the ribbon is 17.5 kG under the applied field of 12 kG. The as-cast ribbons consist of disordered A2 structure with a low volume of B2 phases while the annealed microstructure comprises a dispersion of B2 domains in the disordered A2 matrix. The alloy shows the enhancement of the soft magnetic properties with a reduction in coercivity from 150 A/m in the as-cast state to 45 A/m in the annealed condition at 850 deg. C.

  19. SEALING SIMULATED LEAKS

    Energy Technology Data Exchange (ETDEWEB)

    Michael A. Romano

    2004-09-01

    This report details the testing equipment, procedures and results performed under Task 7.2 Sealing Simulated Leaks. In terms of our ability to seal leaks identified in the technical topical report, Analysis of Current Field Data, we were 100% successful. In regards to maintaining seal integrity after pigging operations we achieved varying degrees of success. Internal Corrosion defects proved to be the most resistant to the effects of pigging while External Corrosion proved to be the least resistant. Overall, with limitations, pressure activated sealant technology would be a viable option under the right circumstances.

  20. Fog seal guidelines.

    Science.gov (United States)

    2003-10-01

    Fog seals are a method of adding asphalt to an existing pavement surface to improve sealing or waterproofing, prevent further stone loss by holding aggregate in place, or simply improve the surface appearance. However, inappropriate use can result in...

  1. Manifold-splitting regularization, self-linking, twisting, writhing numbers of space-time ribbons

    International Nuclear Information System (INIS)

    Tze, C.H.

    1988-01-01

    The authors present an alternative formulation of Polyakov's regularization of Gauss' integral formula for a single closed Feynman path. A key element in his proof of the D = 3 fermi-bose transmutations induced by topological gauge fields, this regularization is linked here with the existence and properties of a nontrivial topological invariant for a closed space ribbon. This self-linking coefficient, an integer, is the sum of two differential characteristics of the ribbon, its twisting and writhing numbers. These invariants form the basis for a physical interpretation of our regularization. Their connection to Polyakov's spinorization is discussed. The authors further generalize their construction to the self-linking, twisting and writhing of higher dimensional d = eta(odd) submanifolds in D = (2eta + 1) space-time

  2. Reactor vessel sealing plug

    International Nuclear Information System (INIS)

    Dooley, R.A.

    1986-01-01

    An apparatus is described for sealing a cold leg nozzle of a nuclear reactor pressure vessel from a remote location comprising: at least one sealing plug for mechanically sealing the nozzle from the inside of the reactor pressure vessel. The sealing plug includes a plate and a cone assembly having an end part receptive in the nozzle, the plate being axially moveable relative to the cone assembly. The plate and cone assembly have confronting bevelled edges defining an opening therebetween. A primary O-ring is disposed about the opening and is supported on the bevelled edges, the plate being guidably mounted to the cone assembly for movement toward the cone assembly to radially expand the primary O-ring into sealing engagement with the nozzle. A means is included for providing relative movement between the outer plate and the cone assembly

  3. Effect of wheel speed and annealing temperature on microstructure and texture evolution of Ni{sub 45}Mn{sub 36.6}In{sub 13.4}Co{sub 5} ribbon

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yan, E-mail: yanfeng@nwpu.edu.cn [State Key Laboratory of Solidification Processing Northwestern Polytechnical University, Xi' an, Shaanxi 710072 (China); Chen, Hong [State Key Laboratory of Solidification Processing Northwestern Polytechnical University, Xi' an, Shaanxi 710072 (China); Gao, Li [College of Engineering Science and Technology, Shanghai Ocean University, Shanghai 201306 (China); Wang, Haibo [College of Physics and Electronic Engineering, Taizhou University, Taizhou, Zhejiang 318000 (China); Bian, Xiaohai; Gong, Mingjie [State Key Laboratory of Solidification Processing Northwestern Polytechnical University, Xi' an, Shaanxi 710072 (China)

    2016-12-15

    Ni{sub 45}Mn{sub 36.6}In{sub 13.4}Co{sub 5} magnetic shape memory alloy was successfully produced as preferentially textured ribbon by melting spinning with different wheel speed. X-ray diffraction (XRD) and electron back scatter diffraction (EBSD) were used to study structure and texture evolution of these melt-spun ribbons. The thickness of melt-spun ribbon is 42 μm, 65 μm and 30 μm depending on wheel speed of 1 0 m/s, 15 m/s and 20 m/s, respectively. Density of α fiber texture (〈100〉//ND) vary with wheel speed changes, and is most intensive in the ribbon with wheel speed of 15 m/s. Grains of the ribbons grow after being annealed at 873 K, 973 K, 1073 K and 1173 K, recrystallization was not observed in ribbons after being annealed at 873 K but occurred in ribbons after being annealed at higher temperatures. The α fiber texture becomes weaker to some extent after annealing at different temperatures, due to new recrystallization texture formed at the process of annealing. - Highlights: •Sectional part of shape memory ribbon is firstly investigated by EBSD method. •Thickness and texture of ribbons vary with wheel speed. •Annealing temperature affect texture and microstructure evolution greatly. •Recrystallization textures were observed in ribbons after being annealed.

  4. Detection of seal contamination in heat-sealed food packaging based on active infrared thermography

    Science.gov (United States)

    D'huys, Karlien; Saeys, Wouter; De Ketelaere, Bart

    2015-05-01

    In the food industry packaging is often applied to protect the product from the environment, assuring quality and safety throughout shelf life if properly performed. Packaging quality depends on the material used and the closure (seal). The material is selected based on the specific needs of the food product to be wrapped. However, proper closure of the package is often harder to achieve. One problem possibly jeopardizing seal quality is the presence of food particles between the seal. Seal contamination can cause a decreased seal strength and thus an increased packaging failure risk. It can also trigger the formation of microchannels through which air and microorganisms can enter and spoil the enclosed food. Therefore, early detection and removal of seal-contaminated packages from the production chain is essential. In this work, a pulsed-type active thermography method using the heat of the sealing bars as an excitation source was studied for detecting seal contamination. The cooling profile of contaminated seals was recorded. The detection performance of four processing methods (based on a single frame, a fit of the cooling profile, pulsed phase thermography and a matched filter) was compared. High resolution digital images served as a reference to quantify contamination. The lowest detection limit (equivalent diameter of 0.63 mm) and the lowest processing time (0.42 s per sample) were obtained for the method based on a single frame. Presumably, practical limitations in the recording stage prevented the added value of active thermography to be fully reflected in this application.

  5. Microstructure, biocorrosion and cytotoxicity evaluations of rapid solidified Mg-3Ca alloy ribbons as a biodegradable material

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X N; Zhou, W R; Zheng, Y F [State Key Laboratory for Turbulence and Complex System and Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871 (China); Li, X L [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Cheng, Y, E-mail: yfzheng@pku.edu.c [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China)

    2010-06-01

    Rapidly solidified (RS) Mg-3Ca alloy ribbons were prepared by the melt-spinning technique at different wheel rotating speeds (15 m s{sup -1}, 30 m s{sup -1} and 45 m s{sup -1}) with the as-cast Mg-3Ca alloy ingot as a raw material. The RS45 Mg-3Ca alloy ribbon showed a much more fine grain size feature (approximately 200-500 nm) in comparison to the coarse grain size (50-100 {mu}m) of the original as-cast Mg-3Ca alloy ingot. The corrosion electrochemical tests in simulated body fluid indicated that the corrosion rate of the as-cast Mg-3Ca alloy was strongly reduced by the RS procedure and tended to be further decreased with increasing wheel rotating speeds (1.43 mm yr{sup -1} for RS15, 0.94 mm yr{sup -1} for RS30 and 0.36 mm yr{sup -1} for RS45). The RS Mg-3Ca alloy ribbons showed more uniform corrosion morphology compared with the as-cast Mg-3Ca alloy after polarization. The cytotoxicity evaluation revealed that the three experimental as-spun Mg-3Ca alloy ribbon extracts did not induce toxicity to the L-929 cells, whereas the as-cast Mg-3Ca alloy ingot extract did. The L-929 cells showed more improved adhesion on the surfaces of the three as-spun Mg-3Ca alloy ribbons than that of the as-cast Mg-3Ca alloy ingot.

  6. SPECTROSCOPIC OBSERVATIONS OF AN EVOLVING FLARE RIBBON SUBSTRUCTURE SUGGESTING ORIGIN IN CURRENT SHEET WAVES

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, S. R.; Longcope, D. W.; Qiu, J. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

    2015-09-01

    We present imaging and spectroscopic observations from the Interface Region Imaging Spectrograph of the evolution of the flare ribbon in the SOL2014-04-18T13:03 M-class flare event, at high spatial resolution and time cadence. These observations reveal small-scale substructure within the ribbon, which manifests as coherent quasi-periodic oscillations in both position and Doppler velocities. We consider various alternative explanations for these oscillations, including modulation of chromospheric evaporation flows. Among these, we find the best support for some form of wave localized to the coronal current sheet, such as a tearing mode or Kelvin–Helmholtz instability.

  7. Shaft Seal Compensates for Cold Flow

    Science.gov (United States)

    Myers, W. N.; Hein, L. A.

    1985-01-01

    Seal components easy to install. Ring seal for rotating or reciprocating shafts spring-loaded to compensate for slow yielding (cold flow) of sealing material. New seal relatively easy to install because components preassembled, then installed in one piece.

  8. Film riding seals for rotary machines

    Science.gov (United States)

    Bidkar, Rahul Anil; Sarawate, Neelesh Nandkumar; Wolfe, Christopher Edward; Ruggiero, Eric John; Raj Mohan, Vivek Raja

    2017-03-07

    A seal assembly for a rotary machine is provided. The seal assembly includes multiple sealing device segments disposed circumferentially intermediate to a stationary housing and a rotor. Each of the segments includes a shoe plate with a forward-shoe section and an aft-shoe section having one or more labyrinth teeth therebetween facing the rotor. The sealing device includes a stator interface element having a groove or slot for allowing disposal of a spline seal for preventing segment leakages. The sealing device segment also includes multiple bellow springs or flexures connected to the shoe plate and to the stator interface element. Further, the sealing device segments include a secondary seal integrated with the stator interface element at one end and positioned about the multiple bellow springs or flexures and the shoe plate at the other end.

  9. Partially and fully de-alloyed glassy ribbons based on Au: Application in methanol electro-oxidation studies

    Energy Technology Data Exchange (ETDEWEB)

    Paschalidou, Eirini Maria, E-mail: epaschal@unito.it [Dipartimento di Chimica e Centro Interdipartimentale NIS (Nanostructured Surfaces and Interfaces), Università di Torino, Via Pietro Giuria 7, 10125, Torino (Italy); Scaglione, Federico [Dipartimento di Chimica e Centro Interdipartimentale NIS (Nanostructured Surfaces and Interfaces), Università di Torino, Via Pietro Giuria 7, 10125, Torino (Italy); Gebert, Annett; Oswald, Steffen [Leibniz Institut für Festkörper- und Werkstoffforschung IFW, Helmholtzstraße 20, 01069, Dresden (Germany); Rizzi, Paola; Battezzati, Livio [Dipartimento di Chimica e Centro Interdipartimentale NIS (Nanostructured Surfaces and Interfaces), Università di Torino, Via Pietro Giuria 7, 10125, Torino (Italy)

    2016-05-15

    In this work, electrochemical de-alloying of an amorphous alloy, Au{sub 40}Cu{sub 28}Ag{sub 7}Pd{sub 5}Si{sub 20}, cast in ribbon form by melt spinning, has been performed, obtaining self standing nanoporous materials suitable for use as electrodes for electrocatalytic applications. The de-alloying encompasses removal of less noble elements and the crystallization of Au, resulting in interconnected ligaments whose size and morphology are described as a function of time. Depending on de-alloying time, the crystals may contain residual amounts of Cu, Ag and Pd, as shown by Auger Electron Spectroscopy (AES), Energy Dispersive Spectroscopy (EDS) and Cyclic Voltammetry (CV) in a basic solution. Current density peaks in the 0.16–0.28 V range (vs Ag/AgCl) indicate that the porous ribbons are active for the electro-oxidation of methanol. The partially de-alloyed samples, which still partially contain the amorphous phase because of the shorter etching times, have finer ligaments and display peaks at lower potential. However, the current density decreases rapidly during repeated potential scans. This is attributed to the obstruction of Au sites, mainly by the Cu oxides formed during the scans. The fully de-alloyed ribbons display current peaks at about 0.20 V and remain active for hundreds of scans at more than 60% of the initial current density. They can be fully re-activated to achieve the same performance levels after a brief immersion in nitric acid. The good activity is due to trapped Ag and Pd atoms in combination with ligament morphology. - Graphical abstract: Fine ligaments and pores made by de-alloying a glassy ribbon of a Au-based alloy, homogeneously produced across the thickness (25 μm) for studying methanol's electro-oxidation behavior. - Highlights: • Size and composition of nanoporous layers tailored in de-alloying Au-based glassy ribbons. • From amorphous precursor fine crystals occur in ligaments with residual Pd and Ag. • Fully de

  10. Flare Ribbon Expansion and Energy Release Ayumi Asai , Takaaki ...

    Indian Academy of Sciences (India)

    2001-04-10

    1Nobeyama Solar Radio Observatory, Minamisaku, Nagano, 384-1305, Japan. ... X2.3 solar flare which occurred on April 10, 2001. .... In the right panel of. Fig. 3, we show the temporal variation of the physical parameters, such as Bp, vf , ˙ , and S along a slit line. Here, we defined vf as the speed of the flare-ribbon ...

  11. Low-Torque Seal Development

    Science.gov (United States)

    Lattime, Scott B.; Borowski, Richard

    2009-01-01

    The EcoTurn Class K production prototypes have passed all AAR qualification tests and received conditional approval. The accelerated life test on the second set of seals is in progress. Due to the performance of the first set, no problems are expected.The seal has demonstrated superior performance over the HDL seal in the test lab with virtually zero torque and excellent contamination exclusion and grease retention.

  12. Improved magnetoimpedance and mechanical properties on nanocrystallization of amorphous Fe68.5Si18.5Cu1Nb3B9 ribbons

    International Nuclear Information System (INIS)

    Sahoo, Trilochan; Majumdar, B.; Srinivas, V.; Srinivas, M.; Nath, T.K.; Agarwal, G.

    2013-01-01

    The effect of heat-treatment temperature on evolution of microstructures, mechanical and soft magnetic properties and magnetoimpedance (MI) effect in rapidly solidified Fe 68.5 Si 18.5 Cu 1 Nb 3 B 9 ribbons, has been investigated. The as-quenched ribbons were subjected to heat-treatment at different temperatures between 400 and 600 °C for 1 h under high vacuum. Detailed structural studies on the ribbons heat-treated at and above 525 °C revealed the presence of nanocrystalline Fe 3 Si phases embedded in a residual amorphous matrix. The ribbon heat-treated at 550 °C temperature exhibits maximum ductility, maximum relative permeability of 4.8×10 4 , minimum coercivity of 0.1 Oe, and maximum MI value of 62%. The enhanced MI effect is believed to be related to the magnetic softening of 550 °C heat-treated ribbons. However, the magnetic properties and MI effect deteriorated in the samples heat-treated above 550 °C due to the coarsening of grain sizes. The soft magnetic behavior of the nanocrystalline ribbons are discussed in the light of random anisotropy model, whereas the MI effect is discussed through standard skin effect in electrodynamics. - Highlights: • Microstructure was tuned by controlled crystallization to obtain superior magnetic properties. • Improved MI in the heat-treated ribbons is attributed to the superior electromagnetic properties. • Correlation between MI and magnetic properties of nc-Fe 68.5 Si 18.5 Cu 1 Nb 3 B 9 is established. • All the observed features are consistent with the proposed random anisotropy model

  13. THE SURFACE STRUCTURAL AND MECHANICAL PROPERTIES OF THE AMORPHOUS CO22Y54AL24 RIBBON

    Directory of Open Access Journals (Sweden)

    Anna Bukowska

    2013-09-01

    Full Text Available The aim of this study was to manufacture amorphous Co22Y54Al24 alloy in a form of thin ribbons and to investigate their properties. The investigated ribbons were prepared by rapid solidification of molten metal on a rotating copper cylinder (melt-spinning. In order to obtain the material with amorphous structure, the cooling rate of the liquid alloy should vary in a range from 104 to 106 K/s. The microstructure studies were performed using X-ray diffractometery. The mechanical properties were investigated by metallographic studies, micro-hardness and tribological resistance tests moreover the surface roughness profile were analyzed. All studies were performed for two sides of tapes, since the differences in ribbons surface, related with manufacturing process, are clearly visible. The surface from the bottom (drum side was glossy and from the top side it was shiny.

  14. Refrigeration system with clearance seals

    International Nuclear Information System (INIS)

    Holland, N. J.

    1985-01-01

    In a refrigeration system such as a split Stirling system, fluid seals associated with the reciprocating displacer are virtually dragless clearance seals. Movement of the displacer relative to the pressure variations in the working volume of gas is retarded by a discrete braking element. Because it is not necessary that the brake providing any sealing action, the brake can be designed for greater durability and less dependence on ambient and operating temperatures. Similarly, the clearance seal can be formed of elements having low thermal expansion such that the seal is not temperature dependent. In the primary embodiments the braking element is a split friction brake

  15. Reactor cavity seal ring

    International Nuclear Information System (INIS)

    Hankinson, M.F.

    1986-01-01

    A hydrostatic seal is described for sealing an annular gap between two flat substantially horizontal coplanar surfaces comprising, in combination: a generally flat annular plate of a width sufficient to span a gap between two surfaces: compressible annular sealing means disposed on the bottom surface of the flat annular plate for sealingly engaging the two flat surfaces in response to a downward force exerted on the plate; and fastening means, distributed along the center line of the plate, for releasably fastening the plate in a position to span the gap to be sealed and exert a downward force on the plate, each fastening means including a pair of elongated members of a size to fit into the gap to be sealed, means for mounting the members on the bottom surface of the plate so that at least a portion of each member is radially moveable in a direction toward a respective one of the vertical side surfaces defining the gap to be sealed to engage same and so that the plate is moveable relative to the members in a downward direction in response to hydrostatic pressure applied to the upper surface of the plate when the members are engaging the vertical side surfaces of an annular gap, and an actuating means, mounted on the plate for movement therewith in response to hydrostatic pressure, for radially moving the members, the actuating means extending through a bore in the plate to the upper surface of the plate

  16. Microstructure, mechanical and functional properties of NiTi-based shape memory ribbons

    International Nuclear Information System (INIS)

    Mehrabi, K.; Bruncko, M.; Kneissl, A.C.

    2012-01-01

    Highlights: ► Melt-spun samples exhibited martensite structure and shape memory effects immediately after processing at room temperature. ► Using a new etchant and interference contrast, it is possible to reveal the fine microstructures and grain boundaries. ► The martensite structure in NiTi is very fine, and nano-sized twin boundaries could be revealed using TEM only. ► Two-way effects have been successfully introduced by different thermomechanical training methods in NiTi, NiTiCu and NiTiW alloys, which can be used for several applications, e.g. microsensors and microactuators. - Abstract: The present work has been aimed to study the microstructures, functional properties and the influence of different thermomechanical training methods on the two-way shape memory effect in NiTi-based melt-spun ribbons. In order to get small-dimensioned shape memory alloys (SMAs) with good functional and mechanical properties, a rapid solidification technique was employed. Their fracture and elasticity characteristics have been determined, as well as shape memory properties by thermomechanical cycling. The ribbons were trained under tensile and bending deformation by thermal cycling through the phase transformation temperature range. The results displayed that all different training methods were effective in developing a two-way shape memory effect (TWSME). The influence of copper (5–25 at.% Cu) and tungsten (2 at.% W) on the microstructure, and the functional and mechanical behavior of NiTi thin ribbons was also investigated. All samples show a shape memory effect immediately after processing without further heat treatment. The melt-spun ribbons were trained under constant strain (bending and tensile deformation) by thermal cycling through the phase transformation temperature range. The addition of copper was effective to narrow the transformation hysteresis. The W addition has improved the TWSME stability of the NiTi alloys and mechanical properties. Results about

  17. Design considerations for mechanical face seals

    Science.gov (United States)

    Ludwig, L. P.; Greiner, H. F.

    1980-01-01

    Two companion reports deal with design considerations for improving performance of mechanical face seals, one of family of devices used in general area of fluid sealing of rotating shafts. One report deals with basic seal configuration and other with lubrication of seal.

  18. Megalencephaly, polymicrogyria and ribbon-like band heterotopia: A new cortical malformation.

    Science.gov (United States)

    Kobayashi, Yu; Magara, Shinichi; Okazaki, Kenichi; Komatsubara, Takao; Saitsu, Hirotomo; Matsumoto, Naomichi; Kato, Mitsuhiro; Tohyama, Jun

    2016-11-01

    Megalencephalic polymicrogyria syndromes include megalencephaly-capillary malformation and megalencephaly-polymicrogyria-polydactyly-hydrocephalus. Recent genetic studies have identified that genes in the PI3K-AKT pathway are involved in the pathogenesis of these disorders. Herein, we report a patient who presented with developmental delay, epilepsy and peculiar neuroimaging findings of megalencephaly, polymicrogyria, and symmetrical band heterotopia in the periventricular region. The heterotopias exhibited inhomogeneous signals with undulatory mixtures of gray and white matter, resembling ribbon-like heterotopia, with a predominance in the temporal to occipital regions. These neuroradiological findings were not consistent with those in known megalencephalic polymicrogyria syndromes. No genetic abnormality was identified through whole-exome sequencing. The neuroimaging findings of this patient may represent a novel cortical malformation involving megalencephaly with polymicrogyria and ribbon-like band heterotopia. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  19. Comparison of mechanical behavior between bulk and ribbon Cu-based metallic glasses

    International Nuclear Information System (INIS)

    Jiang, W.H.; Liu, F.X.; Wang, Y.D.; Zhang, H.F.; Choo, H.; Liaw, P.K.

    2006-01-01

    As-cast bulk and as-spun ribbon Cu 60 Zr 30 Ti 10 metallic glasses were characterized using differential-scanning calorimetry and instrumented nanoindentation. Two alloys show a significant difference in the amount of free volume, which is attributed to the difference in a cooling rate, while exhibiting a similar serrated plastic flow. Atomic-force-microscopy observations demonstrate the pile-ups containing shear bands around the indents in both alloys. The as-cast bulk alloy has higher hardness and elastic modulus than the as-spun ribbon alloy. The difference in the strengths of two alloys may be related to the different amount of free volume. The strength seems to be more sensitive to a cooling rate during solidification than the plastic-flow behavior in the Cu 60 Zr 30 Ti 10

  20. EBR-II rotating plug seal maintenance

    International Nuclear Information System (INIS)

    Allen, K.J.

    1986-01-01

    The EBR-II rotating plug seals require frequent cleaning and maintenance to keep the plugs from sticking during fuel handling. Time consuming cleaning on the cover gas and air sides of the dip ring seal is required to remove oxidation and sodium reaction products that accumulate and stop plug rotation. Despite severely limited access, effective seal cleaning techniques have removed 11 800 lb (5 352 kg) of deposits from the seals since 1964. Temperature control modifications and repairs have also required major maintenance work. Suggested seal design recommendations could significantly reduce maintenance on future similar seals

  1. The discovery of 9/8-ribbons, β/γ-peptides with curved shapes governed by a combined configuration-conformation code.

    Science.gov (United States)

    Grison, Claire M; Robin, Sylvie; Aitken, David J

    2015-11-21

    The de novo design of a β/γ-peptidic foldamer motif has led to the discovery of an unprecedented 9/8-ribbon featuring an uninterrupted alternating C9/C8 hydrogen-bonding network. The ribbons adopt partially curved topologies determined synchronistically by the β-residue configuration and the γ-residue conformation sets.

  2. Effects of Zr on microstructure and mechanical properties of Al-Cu base ribbons spun by planar flow casting

    Science.gov (United States)

    Lee, S. M.; Hong, C. P.

    1998-04-01

    The effects of the Zr addition on the solidification behavior and mechanical properties of the AI-Cu alloy ribbon have been investigated. Zr addition reduced the average grain size of the ribbon at the wheel-side surface, and promoted the microstructural transition into cellular/dendritic structure. Another noteworthy effect of Zr was the homogenization of the microstructure. The addition of Zr up to 0.5 wt.% in the /U-4.3 wt.% Cu ribbon resulted in a considerable increase in hardness at both the wheel-side and the air-side surfaces. The yield strength increased with the addition of Zr due to the grain refincment and more homogeneous distribution of ZrAI, particles. despite no noticeable improvement of the ductility.

  3. Tamper-indicating quantum optical seals

    Energy Technology Data Exchange (ETDEWEB)

    Humble, Travis S [ORNL; Williams, Brian P [ORNL

    2015-01-01

    Confidence in the means for identifying when tampering occurs is critical for containment and surveillance technologies. Fiber-optic seals have proven especially useful for actively surveying large areas or inventories due to the extended transmission range and flexible layout of fiber. However, it is reasonable to suspect that an intruder could tamper with a fiber-optic sensor by accurately replicating the light transmitted through the fiber. In this contribution, we demonstrate a novel approach to using fiber-optic seals for safeguarding large-scale inventories with increased confidence in the state of the seal. Our approach is based on the use of quantum mechanical phenomena to offer unprecedented surety in the authentication of the seal state. In particular, we show how quantum entangled photons can be used to monitor the integrity of a fiber-optic cable - the entangled photons serve as active sensing elements whose non-local correlations indicate normal seal operation. Moreover, we prove using the quantum no-cloning theorem that attacks against the quantum seal necessarily disturb its state and that these disturbances are immediately detected. Our quantum approach to seal authentication is based on physical principles alone and does not require the use of secret or proprietary information to ensure proper operation. We demonstrate an implementation of the quantum seal using a pair of entangled photons and we summarize our experimental results including the probability of detecting intrusions and the overall stability of the system design. We conclude by discussing the use of both free-space and fiber-based quantum seals for surveying large areas and inventories.

  4. Repository Closure and Sealing Approach

    International Nuclear Information System (INIS)

    A.T. Watkins

    2000-01-01

    The scope of this analysis will be to develop the conceptual design of the closure seals and their locations in the Subsurface Facilities. The design will be based on the recently established program requirements for transitioning to the Site Recommendation (SR) design as outlined by ''Approach to Implementing the Site Recommendation Baseline'' (Stroupe 2000) and the ''Monitored Geologic Repository Project Description Document'' (CRWMS M andO 1999b). The objective of this analysis will be to assist in providing a description for the Subsurface Facilities System Description Document, Section 2 and finally to document any conclusions reached in order to contribute and provide support to the SR. This analysis is at a conceptual level and is considered adequate to support the SR design. The final closure barriers and seals for the ventilation shafts, and the north and south ramps will require these openings to be permanently sealed to limit excessive air and water inflows and prevent human intrusion. The major tasks identified with closure in this analysis are: (1) Developing the overall subsurface seal layout and identifying design and operational interfaces for the Subsurface Facilities. (2) Summarizing the general site conditions and general rock characteristic with respect to seal location and describing the seal selected. (3) Identify seal construction materials, methodology of construction and strategic locations including design of the seal and plugs. (4) Discussing methods to prevent human intrusion

  5. Laser based thermo-conductometry as an approach to determine ribbon solid fraction off-line and in-line.

    Science.gov (United States)

    Wiedey, Raphael; Šibanc, Rok; Kleinebudde, Peter

    2018-06-06

    Ribbon solid fraction is one of the most important quality attributes during roll compaction/dry granulation. Accurate and precise determination is challenging and no in-line measurement tool has been generally accepted, yet. In this study, a new analytical tool with potential off-line as well as in-line applicability is described. It is based on the thermo-conductivity of the compacted material, which is known to depend on the solid fraction. A laser diode was used to punctually heat the ribbon and the heat propagation monitored by infrared thermography. After performing a Gaussian fit of the transverse ribbon profile, the scale parameter σ showed correlation to ribbon solid fraction in off-line as well as in-line studies. Accurate predictions of the solid fraction were possible for a relevant range of process settings. Drug stability was not affected, as could be demonstrated for the model drug nifedipine. The application of this technique was limited when using certain fillers and working at higher roll speeds. This study showed the potentials of this new technique and is a starting point for additional work that has to be done to overcome these challenges. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Air riding seal with purge cavity

    Science.gov (United States)

    Sexton, Thomas D; Mills, Jacob A

    2017-08-15

    An air riding seal for a turbine in a gas turbine engine, where an annular piston is axial moveable within an annular piston chamber formed in a stator of the turbine and forms a seal with a surface on the rotor using pressurized air that forms a cushion in a pocket of the annular piston. A purge cavity is formed on the annular piston and is connected to a purge hole that extends through the annular piston to a lower pressure region around the annular piston or through the rotor to an opposite side. The annular piston is sealed also with inner and outer seals that can be a labyrinth seal to form an additional seal than the cushion of air in the pocket to prevent the face of the air riding seal from overheating.

  7. Seals in nuclear reactors

    International Nuclear Information System (INIS)

    1979-01-01

    The aim of this invention is the provision of improved seals for reactor vessels in which fuel assemblies are located together with inlets and outlets for the circulation of a coolant. The object is to provide a seal arrangement for the rotatable plugs of nuclear reactor closure heads which has good sealing capacities over a wide gap during operation of the reactor but which also permits uninhibited rotation of the plugs for maintenance. (U.K.)

  8. Glassy formation ability, magnetic properties and magnetocaloric effect in Al27Cu18Er55 amorphous ribbon

    Science.gov (United States)

    Li, Lingwei; Xu, Chi; Yuan, Ye; Zhou, Shengqiang

    2018-05-01

    In this work, we have fabricated the Al27Cu18Er55 amorphous ribbon with good glassy formation ability by melt-spinning technology. A broad paramagnetic (PM) to ferromagnetic (FM) transition (second ordered) together with a large reversible magnetocaloric effect (MCE) in Al27Cu18Er55 amorphous ribbon was observed around the Curie temperature TC ∼ 11 K. Under the magnetic field change (ΔH of 0-7 T, the values of MCE parameter of the maximum magnetic entropy change (-ΔSMmax) and refrigerant capacity (RC) for Al27Cu18Er55 amorphous ribbon reach 21.4 J/kg K and 599 J/kg, respectively. The outstanding glass forming ability as well as the excellent magneto-caloric properties indicate that Al27Cu18Er55 amorphous could be a good candidate for low temperature magnetic refrigeration.

  9. Template synthesis and characterization of nanostructured hierarchical mesoporous ribbon-like NiO as high performance electrode material for supercapacitor

    International Nuclear Information System (INIS)

    Yao, Mingming; Hu, Zhonghua; Xu, Zijie; Liu, Yafei; Liu, Peipei; Zhang, Qiang

    2015-01-01

    The ribbon-like NiO was synthesized by a hard-template method combining the calcination, using mesoporous carbon as a hard templat and guanidine hydrochloride as precipitant of weak base, respectively. The nanostructured hierarchical mesoporous ribbon-like NiO exhibits the high specific capacitance of 1260 F g −1 at the current density of 1 A g −1 , and 95% capacity retention at a current density of 10 A g −1 in a testing range of 5000 cycles. - Highlights: • Ribbon-like NiO was prepared by using mesoporous carbon as a hard template. • Typical ribbon-like NiO possesses the hierarchical mesoporous nanostructure. • High specific capacitance of 1260 F g −1 is obtained at a current density of 1 A g −1 . • Excellent electrochemical stability of 95% after 5000 charge–discharge cycles. - Abstract: In this paper, nanostructured hierarchical mesoporous ribbon-like NiO was synthesized by a hard-template method combining the calcination process. Nickel sulfate hexahydrate, guanidine hydrochloride and mesoporous carbon were used as nickel precursors, precipitant of weak base and template, respectively. The resultant NiO samples were characterized by Raman spectroscopy, energy dispersive spectrometer, X-ray diffraction, N 2 adsorption and desorption, scanning electron microscopy and transmission electron microscopy. The electrochemical performances were evaluated by cyclic voltammetry (CV), cyclic chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS) in 6 M KOH solution. The typical hierarchical mesoporous ribbon-like NiO shows a good electrochemical performance: a high specific capacitance of 1260 F g −1 at 1 A g −1 , 748 F g −1 at high current density of 20 A g −1 and 95% capacity retention at a current density of 10 A g −1 in a testing range of 5000 cycles

  10. Random anisotropy studies in amorphous Co-Tb ribbons

    International Nuclear Information System (INIS)

    Hassanain, N.; Berrada, A.; Lassri, H.; Krishnan, R.

    1995-01-01

    Amorphous Co 1-x Tb x ribbons with x=0.45, 0.55 and 0.65 have been prepared by melt spinning technique. Magnetization measurements were carried out at 4.2 K, under magnetic fields up to 150 kOe. The Co moment is found to be very small and the Tb moment is 7.15μ B at 4.2 K, which indicates a speromagnetic spin structure. Using Chudnovsky's theory we have extracted some fundamental magnetic parameters. ((orig.))

  11. Random anisotropy studies in amorphous CoTb ribbons

    Science.gov (United States)

    Hassanain, N.; Berrada, A.; Lassri, H.; Krishnan, R.

    1995-02-01

    Amorphous Co 1- xTb x ribbons with x = 0.45, 0.55 and 0.65 have been prepared by melt spinning technique. Magnetization measurements were carried out at 4.2 K, under magnetic fields up to 150 kOe. The Co moment is found to be very small and the Tb moment is 7.15 μB at 4.2 K, which indicates a speromagnetic spin structure. Using Chudnovsky's theory we have extracted some fundamental magnetic parameters.

  12. Self-acting and hydrodynamic shaft seals

    Science.gov (United States)

    Ludwig, L. P.

    1973-01-01

    Self-acting and hydrodynamic seals are described. The analytical procedures are outlined for obtaining a seal force balance and the operating film thickness. Particular attention is given to primary ring response (seal vibration) to rotating seat face runout. This response analysis revealed three different vibration modes. Proposed applications of self-acting seals in gas turbine engines and in rocket vehicle turbopumps are described. Also experimental data on self-acting face seals operating under simulated gas turbine conditions are given; these data show the feasibility of operating the seal at conditions of 345 newtons per square centimeter (500 psi) and 152 meters per second (500 ft/sec) sliding speed.

  13. Radial lip seals, thermal aspects

    NARCIS (Netherlands)

    Stakenborg, M.J.L.; van Ostaijen, R.A.J.; Dowson, D.

    1989-01-01

    In this paper the influence of temperature on tne seal-snarc contact is studied, using coupled temperature-stress FEH analysis. A thermal network model is used to calculate the seal-shaft contact temperature for steady-state and transient conditions. Contact temperatures were measured under the seal

  14. Airfoil seal system for gas turbine engine

    Science.gov (United States)

    None, None

    2013-06-25

    A turbine airfoil seal system of a turbine engine having a seal base with a plurality of seal strips extending therefrom for sealing gaps between rotational airfoils and adjacent stationary components. The seal strips may overlap each other and may be generally aligned with each other. The seal strips may flex during operation to further reduce the gap between the rotational airfoils and adjacent stationary components.

  15. Analysis on the Viscous Pumping in a Magnetic Fluid Seal Under a Rotating Load and the Seal Design

    OpenAIRE

    長屋, 幸助; 大沼, 浩身; 佐藤, 淳

    1990-01-01

    This paper discusses effects of viscous pumping in a magnetic fluid seal under a rotating load. The Reynolds equation was presented for the seal based on magnetic fluid mechanics, and the expressions for obtaining pressures in the seal, eccentricities of the rotating shaft due to the viscous pumping and seal pressures were given. Numerical Calculations were carried out for some sample problems, and the effect of magnetic flux densities on the pressure in the seal and the seal pressures were c...

  16. Albinistic common seals (Phoca vitulina) and melanistic grey seals (Halichoerus grypus) rehabilitated in the Netherlands

    NARCIS (Netherlands)

    Osinga, Nynke; 't Hart, Pieter; Vader, Pieter C. van Voorst

    2010-01-01

    The Seal Rehabilitation and Research Centre (SRRC) in Pieterburen, The Netherlands, rehabilitates seals from the waters of the Wadden Sea, North Sea and Southwest Delta area. Incidental observations of albinism and melanism in common and grey seals are known from countries surrounding the North Sea.

  17. Enhanced sealing project: monitoring the THM response of a full-scale shaft seal

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, D.A.; Martino, J.B.; Holowick, B.; Priyanto, D. [Atomic Energy of Canada Limited, Pinawa, MB (Canada)

    2011-07-01

    Closure of the subsurface facilities at Atomic Energy of Canada Limited's (AECL) Underground Research Laboratory (URL) was completed in 2010 with installation of a concrete surface cap. Additionally, as part of decommissioning, seals were installed at the penetration of the shafts through the major hydro-geological feature known as Fracture Zone 2 (FZ2). The seal construction was funded by Natural Resources Canada (NRCan) under the Nuclear Legacy Liabilities Program (NLLP). The shaft seals at the URL were based on the composite seal concept developed for application in a deep geological repository for disposal of used nuclear fuel. The access shaft seal consists of two 3-m thick concrete segments that rigidly confine a 6-m long section of swelling clay-based material (40% bentonite clay - 60% sand by dry mass). Monitoring of the regional groundwater recovery following flooding of the lower shaft is a closure requirement and was included in the design. It was widely recognized that the installation of the seals at the URL represented a unique opportunity to monitor the evolution of the type of seal that might be installed in an actual repository but the NLLP mandate did not include any monitoring of shaft seal evolution. As a result the Enhanced Sealing Project (ESP) partnership composed of NWMO, Posiva, SKB and ANDRA was established and a set of 68 instruments (containing 100 sensors) were installed to monitor the evolution of the seal. In the first year of operation sensors have monitored the following parameters in the ESP: thermal evolution and strain of the concrete components, thermal, hydraulic and mechanical changes in the clay component and its contacts with the rock and concrete confinement. Additionally, monitoring of the near-field and regional groundwater evolution has been undertaken. Monitoring of the short-term thermal-mechanical evolution of the concrete components was successfully accomplished and only a small temperature rise occurred due to

  18. Enhanced sealing project: monitoring the THM response of a full-scale shaft seal

    International Nuclear Information System (INIS)

    Dixon, D.A.; Martino, J.B.; Holowick, B.; Priyanto, D.

    2011-01-01

    Closure of the subsurface facilities at Atomic Energy of Canada Limited's (AECL) Underground Research Laboratory (URL) was completed in 2010 with installation of a concrete surface cap. Additionally, as part of decommissioning, seals were installed at the penetration of the shafts through the major hydro-geological feature known as Fracture Zone 2 (FZ2). The seal construction was funded by Natural Resources Canada (NRCan) under the Nuclear Legacy Liabilities Program (NLLP). The shaft seals at the URL were based on the composite seal concept developed for application in a deep geological repository for disposal of used nuclear fuel. The access shaft seal consists of two 3-m thick concrete segments that rigidly confine a 6-m long section of swelling clay-based material (40% bentonite clay - 60% sand by dry mass). Monitoring of the regional groundwater recovery following flooding of the lower shaft is a closure requirement and was included in the design. It was widely recognized that the installation of the seals at the URL represented a unique opportunity to monitor the evolution of the type of seal that might be installed in an actual repository but the NLLP mandate did not include any monitoring of shaft seal evolution. As a result the Enhanced Sealing Project (ESP) partnership composed of NWMO, Posiva, SKB and ANDRA was established and a set of 68 instruments (containing 100 sensors) were installed to monitor the evolution of the seal. In the first year of operation sensors have monitored the following parameters in the ESP: thermal evolution and strain of the concrete components, thermal, hydraulic and mechanical changes in the clay component and its contacts with the rock and concrete confinement. Additionally, monitoring of the near-field and regional groundwater evolution has been undertaken. Monitoring of the short-term thermal-mechanical evolution of the concrete components was successfully accomplished and only a small temperature rise occurred due to

  19. 19 CFR 113.25 - Seals.

    Science.gov (United States)

    2010-04-01

    ... signatures of principal and surety, if individuals, and the corporate seal shall be affixed close to the... law of the state in which executed. However, when the charter or governing statute of a corporation requires its acts to be evidenced by its corporate seal, such seal is required. ...

  20. High temperature (900-1300 C) mechanical behaviour of dendritic web grown silicon ribbons - Strain rate and temperature dependence of the yield stress

    Science.gov (United States)

    Mathews, V. K.; Gross, T. S.

    1987-01-01

    The mechanical behavior of dendritic web Si ribbons close the melting point was studied experimentally. The goal of the study was to generate data for modeling the generation of stresses and dislocation structures during growth of dendritic web Si ribbons, thereby permitting modifications to the production process, i.e., the temperature profile, to lower production costs for the photovoltaic ribbons. A laser was used to cut specimens in the direction of growth of sample ribbons, which were then subjected to tensile tests at temperatures up to 1300 C in an Ar atmosphere. The tensile strengths of the samples increased when the temperature rose above 1200 C, a phenomena which was attributed to the diffusion of oxygen atoms to the quasi-dislocation sites. The migration to the potential dislocations sites effectively locked the dislocations.

  1. Surface plasmon enhanced absorption and suppressed transmission in periodic arrays of graphene ribbons

    Science.gov (United States)

    Nikitin, A. Yu.; Guinea, F.; Garcia-Vidal, F. J.; Martin-Moreno, L.

    2012-02-01

    Resonance diffraction in the periodic array of graphene microribbons is theoretically studied following a recent experiment [L. Ju , Nature Nanotech.1748-338710.1038/nnano.2011.146 6, 630 (2011)]. Systematic studies over a wide range of parameters are presented. It is shown that a much richer resonant picture would be observable for higher relaxation times of charge carriers: More resonances appear and transmission can be totally suppressed. The comparison with the absorption cross-section of a single ribbon shows that the resonant features of the periodic array are associated with leaky plasmonic modes. The longest-wavelength resonance provides the highest visibility of the transmission dip and has the strongest spectral shift and broadening with respect to the single-ribbon resonance, due to collective effects.

  2. Thermal Conductivity of Graphene-hBN Superlattice Ribbons.

    Science.gov (United States)

    Felix, Isaac M; Pereira, Luiz Felipe C

    2018-02-09

    Superlattices are ideal model systems for the realization and understanding of coherent (wave-like) and incoherent (particle-like) phonon thermal transport. Single layer heterostructures of graphene and hexagonal boron nitride have been produced recently with sharp edges and controlled domain sizes. In this study we employ nonequilibrium molecular dynamics simulations to investigate the thermal conductivity of superlattice nanoribbons with equal-sized domains of graphene and hexagonal boron nitride. We analyze the dependence of the conductivity with the domain sizes, and with the total length of the ribbons. We determine that the thermal conductivity reaches a minimum value of 89 W m -1 K -1 for ribbons with a superlattice period of 3.43 nm. The effective phonon mean free path is also determined and shows a minimum value of 32 nm for the same superlattice period. Our results also reveal that a crossover from coherent to incoherent phonon transport is present at room temperature for BNC nanoribbons, as the superlattice period becomes comparable to the phonon coherence length. Analyzing phonon populations relative to the smallest superlattice period, we attribute the minimum thermal conductivity to a reduction in the population of flexural phonons when the superlattice period equals 3.43 nm. The ability to manipulate thermal conductivity using superlattice-based two-dimensional materials, such as graphene-hBN nanoribbons, opens up opportunities for application in future nanostructured thermoelectric devices.

  3. Student Evaluation of the Yellow Ribbon Suicide Prevention Program in Midwest Schools

    Science.gov (United States)

    Flynn, Alexandra; Zackula, Rosalee; Klaus, Nicole M.; McGinness, Liz; Carr, Susan; Macaluso, Matthew

    2016-01-01

    Objective Yellow Ribbon is a gatekeeper-type suicide prevention program that is widely used in public schools. However, data on its effectiveness are limited. The purpose of our study was to evaluate self-reported changes in knowledge and comfort level communicating about suicide following Yellow Ribbon training for a large, representative sample of students from a public school system in the midwestern United States. Methods The program was administered to students within the same school district during 2006 through 2009. A pre-post survey using a 4-point Likert scale was administered to rate students’ knowledge of risk factors and available resources, comfort level communicating about suicide, estimate of friends at risk for suicide, and behavioral intent toward help-seeking. Results Aggregate responses from 3,257 students, aged 11 to 18 years, were collected by the schools; 51% were female, 33% were Hispanic, and 30% were white. Suicide-related knowledge of risk factors, where to go for help, and resources, along with comfort level in asking for help, all significantly improved following program participation (Cramer’s V = 0.243 to 0.376, P suicide prevention program appears to be beneficial for students in the midwestern United States. We observed significant improvement in knowledge, comfort level, and behavioral intent for help-seeking if suicidal thoughts occur. Findings also suggested that Yellow Ribbon training administered during middle school may be especially helpful for males. PMID:27733952

  4. Upgrading primary heat transport pump seals

    International Nuclear Information System (INIS)

    Graham, T.; Metcalfe, R.; Rhodes, D.; McInnes, D.

    1995-01-01

    Changes in the operating environment at the Bruce-A Nuclear Generating Station created the need for an upgraded Primary Heat Transport Pump (PHTP) seal. In particular, the requirement for low pressure running during more frequent start-ups exposed a weakness of the CAN2 seal and reduced its reliability. The primary concern at Bruce-A was the rotation of the CAN2 No. 2 stators in their holders. The introduction of low pressure running exacerbated this problem, giving rapid wear of the stator back face, overheating, and thermocracking. In addition, the resulting increase in friction between the stator and its holder increased stationary-side hysteresis and thereby changed the seal characteristic to the point where interseal pressure oscillations became prevalent. The resultant increased hysteresis also led to hard rubbing of the seal faces during temperature transients. An upgraded seal was required for improved reliability to avoid forced outages and to reduce maintenance costs. This paper describes this upgraded 'replacement seal' and its performance history. In spite of the 'teething' problems detailed in this paper, there have been no forced outages due to the replacement seal, and in the words of a seal maintenance worker at Bruce-A, 'it allows me to go home and sleep at night instead of worrying about seal failures.' (author)

  5. Advanced High Temperature Structural Seals

    Science.gov (United States)

    Newquist, Charles W.; Verzemnieks, Juris; Keller, Peter C.; Rorabaugh, Michael; Shorey, Mark

    2002-10-01

    This program addresses the development of high temperature structural seals for control surfaces for a new generation of small reusable launch vehicles. Successful development will contribute significantly to the mission goal of reducing launch cost for small, 200 to 300 pound payloads. Development of high temperature seals is mission enabling. For instance, ineffective control surface seals can result in high temperature (3100 F) flows in the elevon area exceeding structural material limits. Longer sealing life will allow use for many missions before replacement, contributing to the reduction of hardware, operation and launch costs.

  6. Flat-plate solar array project. Volume 3: Silicon sheet: Wafers and ribbons

    Science.gov (United States)

    Briglio, A.; Dumas, K.; Leipold, M.; Morrison, A.

    1986-01-01

    The primary objective of the Silicon Sheet Task of the Flat-Plate Solar Array (FSA) Project was the development of one or more low cost technologies for producing silicon sheet suitable for processing into cost-competitive solar cells. Silicon sheet refers to high purity crystalline silicon of size and thickness for fabrication into solar cells. Areas covered in the project were ingot growth and casting, wafering, ribbon growth, and other sheet technologies. The task made and fostered significant improvements in silicon sheet including processing of both ingot and ribbon technologies. An additional important outcome was the vastly improved understanding of the characteristics associated with high quality sheet, and the control of the parameters required for higher efficiency solar cells. Although significant sheet cost reductions were made, the technology advancements required to meet the task cost goals were not achieved.

  7. Upgrading inflatable door seals

    International Nuclear Information System (INIS)

    Sykes, T.M.; Metcalfe, R.; Welch, L.A.; Josefowich, J.M.

    1997-01-01

    Inflatable door seals are used for airlocks in CANDU stations. They have been a significant source of unreliability and maintenance cost. A program is underway to improve their performance and reliability, backed by environmental qualification testing. Only commercial products and suppliers existed in 1993. For historical reasons, these 'existing products' did not use the most durable material then available. In hindsight, neither had they been adapted nor optimized to combat conditions often experienced in the plants-sagging doors, damaged sealing surfaces, and many thousands of openings and closings per year. Initial attempts to involve the two existing suppliers in efforts to upgrade these seals were unsuccessful. Another suitable supplier had therefore to be found, and a 'new,' COG-owned seal developed; this was completed in 1997. This paper summarizes its testing, along with that of the two existing products. Resistance to aging has been improved significantly. Testing has shown that an accident can be safely withstood after 10 years of service or 40,000 openings-closings, whichever comes first. AECL's Fluid Sealing Technology Unit (FSTU) has invested in the special moulds, test fixtures and other necessary tooling and documentation required to begin commercial manufacture of this new quality product. Accordingly, as with FSTU's other nuclear products such as pump seals, the long-term supply of door seals to CANDU plants is now protected from many external uncertainties-e.g., commercial products being discontinued, materials being changed, companies going out of business. Manufacturing to AECL's detailed specifications is being subcontracted to the new supplier. FSTU is performing the quality surveillance, inspection, testing, and customer service activities concomitant with direct responsibility for supply to the plants. (author)

  8. Fiber Optic Safeguards Sealing System

    Science.gov (United States)

    1978-01-01

    8217 or trade names does not constitute an official indorsement or approval of the use thereof. Destroy this report when it is no longer needed. Do not...an intergrity check of a seal than to photograph the seal’s fingerprints and to match positive/negative overlays. The seal identification time and

  9. Turbine Seal Research at NASA GRC

    Science.gov (United States)

    Proctor, Margaret P.; Steinetz, Bruce M.; Delgado, Irebert R.; Hendricks, Robert C.

    2011-01-01

    Low-leakage, long-life turbomachinery seals are important to both Space and Aeronautics Missions. (1) Increased payload capability (2) Decreased specific fuel consumption and emissions (3) Decreased direct operating costs. NASA GRC has a history of significant accomplishments and collaboration with industry and academia in seals research. NASA's unique, state-of-the-art High Temperature, High Speed Turbine Seal Test Facility is an asset to the U.S. Engine / Seal Community. Current focus is on developing experimentally validated compliant, non-contacting, high temperature seal designs, analysis, and design methodologies to enable commercialization.

  10. Enhanced sealing project (ESP): design, construction and monitoring of a full-scale shaft seal

    International Nuclear Information System (INIS)

    Dixon, D.; Martino, J.; Kim, C.S.; Holowick, B.; Kwong, G.; Jonsson, E.; Palonen, E.; DeCombarieu, M.

    2010-01-01

    Document available in extended abstract form only. The Enhanced Sealing Project (ESP) consists of instrumenting and monitoring a full-scale shaft seal installed to permanently close the access shaft for Atomic Energy of Canada Limited's (AECL's) Underground Research Laboratory (URL) at the intersection of an ancient low dipping thrust fault. The URL was built to provide a facility where concepts for long-term management of Canada's nuclear fuel waste in a deep geological repository could be studied. Operated since the early 1980's, this facility provided much of the technical information used in developing the deep geological repository concept submitted by AECL to the Government of Canada in 1994 and continued to provide valuable technical data after that submission. In 2003, a decision was made to discontinue operation of the URL and ultimately decommission and permanently close the underground portion of this facility. As part of the Nuclear Legacy Liability Program (NLLP) being funded by Natural Resources Canada (NRCan), facilities including the URL that are no longer part of AECL's mandate or operations are being decommissioned. Included in this work is the installation of seals at the intersection of the access shaft and ventilation raise with a deep fracture zone in order to limit the potential for mixing of deeper saline and shallower less saline groundwater. The funding available from NRCan was limited to the seal installation, with no mandate to provide any more than basic hydrological monitoring of the rock mass at a considerable distance from these seals, and so the opportunity to monitor a full-scale shaft seal similar to one for a deep geological repository would have been lost. The ESP arose from the recognition by a number of organizations that the URL closure presented a unique opportunity to monitor the evolution of a full-scale repository-type shaft seal in a very well-characterized and otherwise undisturbed rock mass. As

  11. Sealed can of spent fuel

    International Nuclear Information System (INIS)

    Suzuki, Yasuyuki.

    1976-01-01

    Object: To provide a seal plug cover with a gripping portion fitted to a canning machine and a gripping portion fitted to a gripper of the same configuration as a fuel body for handling the fuel body so as to facilitate the handling work. Structure: A sealed can comprises a vessel and a seal plug cover, said cover being substantially in the form of a bottomed cylinder, which is slipped on the vessel and air-tightly secured by a fastening bolt between it and a flange. The spent fuel body is received into the vessel together with coolant during the step of canning operation. Said seal plug cover has two gripping portions, one for opening and closing the plug cover of the canning machine as an exclusive use member, the other being in the form of a hook-shaped peripheral groove, whereby the gripping portions may be effectively used using the same gripper when the spent fuel body is transported while being received in the sealed can or when the fuel body is removed from the sealed can. (Kawakami, Y.)

  12. Insecurity of imperfect quantum bit seal

    International Nuclear Information System (INIS)

    Chau, H.F.

    2006-01-01

    Quantum bit seal is a way to encode a classical bit quantum mechanically so that everyone can obtain non-zero information on the value of the bit. Moreover, such an attempt should have a high chance of being detected by an authorized verifier. Surely, a reader looks for a way to get the maximum amount of information on the sealed bit and at the same time to minimize her chance of being caught. And a verifier picks a sealing scheme that maximizes his chance of detecting any measurement of the sealed bit. Here, I report a strategy that passes all measurement detection procedures at least half of the time for all quantum bit sealing schemes. This strategy also minimizes a reader's chance of being caught under a certain scheme. In this way, I extend the result of Bechmann-Pasquinucci et al. by proving that quantum seal is insecure in the case of imperfect sealed bit recovery

  13. Development of variable-width ribbon heating elements for liquid-metal and gas-cooled fast breeder reactor fuel-pin simulators

    International Nuclear Information System (INIS)

    McCulloch, R.W.; Post, D.W.; Lovell, R.T.; Snyder, S.D.

    1981-04-01

    Variable-width ribbon heating elements that provide a chopped-cosine variable heat flux profile have been fabricated for fuel pin simulators used in test loops by the Breeder Reactor Program Thermal-Hydraulic Out-of-Reactor Safety test facility and the Gas-Cooled Fast Breeder Reactor-Core Flow Test Loop. Thermal, mechanical, and electrical design considerations are used to derive an analytical expression that precisely describes ribbon contour in terms of the major fabrication parameters. These parameters are used to generate numerical control tapes that control ribbon cutting and winding machines. Infrared scanning techniques are developed to determine the optimum transient thermal profile of the coils and relate this profile to that generated by the coils in completed fuel pin simulators

  14. Ultrasonic dip seal maintenance system

    International Nuclear Information System (INIS)

    Poindexter, A.M.; Ricks, H.E.

    1978-01-01

    Disclosed is a system for removing impurities from the surfaces of liquid dip seals and for wetting the metal surfaces of liquid dip seals in nuclear components. The system comprises an ultrasonic transducer that transmits ultrasonic vibrations along an ultrasonic probe to the metal and liquid surfaces of the dip seal thereby loosening and removing those impurities

  15. Reusable tamper-indicating security seal

    International Nuclear Information System (INIS)

    Ryan, M.J.

    1981-01-01

    A reusable tamper-indicating mechanical security seal for use in safeguarding nuclear material has been developed. The high-security seal displays an unpredictable, randomly selected, five-digit code each time it is used. This five digit code serves the same purpose that the serial number does for conventional non-reusable seals - a unique identifier for each use or application. The newly developed reusable seal is completely enclosed within a seamless, tamper-indicating, plastic jacket. The jacket is designed to reveal any attempts to penetrate, section or to chemically remove and replace with a counterfeit for surreptitious purposes

  16. Actively controlled shaft seals for aerospace applications

    Science.gov (United States)

    Salant, Richard F.

    1995-07-01

    This study experimentally investigates an actively controlled mechanical seal for aerospace applications. The seal of interest is a gas seal, which is considerably more compact than previous actively controlled mechanical seals that were developed for industrial use. In a mechanical seal, the radial convergence of the seal interface has a primary effect on the film thickness. Active control of the film thickness is established by controlling the radial convergence of the seal interface with a piezoelectric actuator. An actively controlled mechanical seal was initially designed and evaluated using a mathematical model. Based on these results, a seal was fabricated and tested under laboratory conditions. The seal was tested with both helium and air, at rotational speeds up to 3770 rad/sec, and at sealed pressures as high as 1.48 x 10(exp 6) Pa. The seal was operated with both manual control and with a closed-loop control system that used either the leakage rate or face temperature as the feedback. The output of the controller was the voltage applied to the piezoelectric actuator. The seal operated successfully for both short term tests (less than one hour) and for longer term tests (four hours) with a closed-loop control system. The leakage rates were typically 5-15 slm (standard liters per minute), and the face temperatures were generally maintained below 100C. When leakage rate was used as the feedback signal, the setpoint leakage rate was typically maintained within 1 slm. However, larger deviations occurred during sudden changes in sealed pressure. When face temperature was used as the feedback signal, the setpoint face temperature was generally maintained within 3 C, with larger deviations occurring when the sealed pressure changes suddenly. the experimental results were compared to the predictions from the mathematical model. The model was successful in predicting the trends in leakage rate that occurred as the balance ratio and sealed pressure changed

  17. A TWO-RIBBON WHITE-LIGHT FLARE ASSOCIATED WITH A FAILED SOLAR ERUPTION OBSERVED BY ONSET, SDO, AND IRIS

    International Nuclear Information System (INIS)

    Cheng, X.; Hao, Q.; Ding, M. D.; Chen, P. F.; Fang, C.; Liu, K.; Liu, Y. D.

    2015-01-01

    Two-ribbon brightenings are one of the most remarkable characteristics of an eruptive solar flare and are often used to predict the occurrence of coronal mass ejections (CMEs). Nevertheless, it was recently called into question whether all two-ribbon flares are eruptive. In this paper, we investigate a two-ribbon-like white-light (WL) flare that is associated with a failed magnetic flux rope (MFR) eruption on 2015 January 13, which has no accompanying CME in the WL coronagraph. Observations by the Optical and Near-infrared Solar Eruption Tracer and the Solar Dynamics Observatory reveal that with the increase of the flare emission and the acceleration of the unsuccessfully erupting MFR, two isolated kernels appear at the WL 3600 Å passband and quickly develop into two elongated ribbon-like structures. The evolution of the WL continuum enhancement is completely coincident in time with the variation of Fermi hard X-ray 26–50 keV flux. An increase of continuum emission is also clearly visible at the whole FUV and NUV passbands observed by the Interface Region Imaging Spectrograph. Moreover, in one WL kernel, the Si iv, C ii, and Mg ii h/k lines display significant enhancement and non-thermal broadening. However, their Doppler velocity pattern is location-dependent. At the strongly bright pixels, these lines exhibit a blueshift, while at moderately bright ones, the lines are generally redshifted. These results show that the failed MFR eruption is also able to produce a two-ribbon flare and high-energy electrons that heat the lower atmosphere, causing the enhancement of the WL and FUV/NUV continuum emissions and chromospheric evaporation

  18. Pool gateway seal

    International Nuclear Information System (INIS)

    Starr, J.A.; Steinert, L.A.

    1983-01-01

    A device for sealing a gateway between interconnectable pools in a nuclear facility comprising a frame supporting a liquid impermeable sheet positioned in a u-shaped gateway between the pools. An inflatable tube carried in a channel in the periphery of the frame and adjoining the gateway provides a seal therebetween when inflated. A restraining arrangement on the bottom edge of the frame is releasably engagable with an adjacent portion of the gateway to restrict the movement of the frame in the u-shaped gateway upon inflation of the tube, thereby enhancing the seal. The impermeable sheet is formed of an elastomer and thus is conformable to a liquid permeable supportive wall upon application of liquid pressure to the side of the sheet opposite the wall

  19. Development and high temperature sealing performance study of double sealing flange

    International Nuclear Information System (INIS)

    Zhang Qinhua; Fu Yuan; Xie Leidong; Li Zhong; Tang Zhongfeng

    2013-01-01

    Background: Flange is an important component used in the connection between pipes or between pipe and equipment. It is widely used in mechanical industry, petrochemical industry and nuclear industry. Ordinary flange could be oxidized oi corroded under high temperature and strong corrosion condition, which leads to flange's failure. Purpose: The aim is to design and validate the double sealing flange which could be used in high temperature and strong corrosion condition stably and supplied as a reliable detachable connection for petrochemical industry and nuclear industry under high temperature and strong corrosion environment. Methods: New flange is designed using flexible graphite spiral wound gaskets and C style metal ring double sealing structure. The unique protection gas design ensures the graphite spiral wound gasket used in high temperature reliably. Test bed is built to verify the stability of the flange. Results: Pressure reducing of graphite spiral wound gasket is only 0.01 MPa at 750℃, 0.7 MPa for 43 h, there is not obvious oxidation phenomenon at the same time. The leakage rate of metal C sealing ring is 11.51×10 -4 atm cc/s, and the metal C ring sealing's performance meets the engineering requirements. Conclusion: The leakage rate of double sealing flange is almost zero under 0.7 MPa at 750℃, which meets the engineering requirements. It avoids oxidizing at high temperature and corroding under strong corrosion condition. (authors)

  20. Steam Turbine Flow Path Seals (a Review)

    Science.gov (United States)

    Neuimin, V. M.

    2018-03-01

    Various types of shroud, diaphragm, and end seals preventing idle leak of working steam are installed in the flow paths of steam turbine cylinders for improving their efficiency. Widely known labyrinth seals are most extensively used in the Russian turbine construction industry. The category of labyrinth seals also includes seals with honeycomb inserts. The developers of seals with honeycomb inserts state that the use of such seals makes it possible to achieve certain gain due to smaller leaks of working fluid and more reliable operation of the system under the conditions in which the rotor rotating parts may rub against the stator elements. However, a positive effect can only be achieved if the optimal design parameters of the honeycomb structure are fulfilled with due regard to the specific features of its manufacturing technology and provided that this structure is applied in a goal-seeking manner in the seals of steam and gas turbines and compressors without degrading their vibration stability. Calculated and preliminary assessments made by experts testify that the replacement of conventional labyrinth seals by seals with honeycomb inserts alone, due to which the radial gaps in the shroud seal can be decreased from 1.5 to 0.5 mm, allows the turbine cylinder efficiency to be increased at the initial stage by approximately 1% with the corresponding gain in the turbine set power output. The use of rectangular-cellular seals may result, according to estimates made by their developers, in a further improvement of turbine efficiency by 0.5-1.0%. The labor input required to fabricate such seals is six to eight times smaller than that to fabricate labyrinth seals with honeycomb inserts. Recent years have seen the turbine construction companies of the United States and Germany advertising the use of abradable (sealing) coatings (borrowed from the gas turbine construction technology) in the turbine designs instead of labyrinth seals. The most efficient performance of

  1. Generation of second harmonic in off-diagonal magneto-impedance in Co-based amorphous ribbons

    International Nuclear Information System (INIS)

    Buznikov, N A; Yoon, S S; Jin, L; Kim, C O; Kim, C G

    2006-01-01

    The off-diagonal magneto-impedance in Co-based amorphous ribbons was measured using a pick-up coil wound around the sample. The ribbons were annealed in air or in vacuum in the presence of a weak magnetic field. The evolution of the first and second harmonics in the pick-up coil voltage as a function of the current amplitude was studied. At low current amplitudes, the first harmonic dominates in the frequency spectrum of the voltage, and at sufficiently high current amplitudes, the amplitude of the second harmonic becomes higher than that of the first harmonic. For air-annealed ribbons, the asymmetric two-peak behaviour of the field dependences of the harmonic amplitudes was observed, which is related to the coupling between the amorphous phase and surface crystalline layers appearing after annealing. For vacuum-annealed samples, the first harmonic has a maximum at zero external field, and the field dependence of the second harmonic exhibits symmetric two-peak behaviour. The experimental results are interpreted in terms of a quasi-static rotational model. It is shown that the appearance of the second harmonic in the pick-up coil voltage is related to the anti-symmetrical distribution of the transverse field induced by the current. The calculated dependences are in qualitative agreement with the experimental data

  2. Mössbauer and Kerr microscopy investigation of crystallization in FeCoB ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, V. Raghavendra, E-mail: varimalla@yahoo.com, E-mail: vrreddy@csr.res.in; Hussain, Zaineb; Babu, Hari [UGC DAE Consortium for Scientific Research, University Campus, Kandhwa Road, Indore-452001 India (India); Shrivastava, Namrata [School of Physics, DAVV, Khandwa Road, Indore – 452001 India (India); Gupta, Ajay [Amity Centre for Spintronic Materials, Amity University, Noida 201303.India (India)

    2016-05-23

    The present work reports the crystallization study of amorphous FeCoB ribbons using x-ray diffraction, {sup 57}Fe Mössbauer spectroscopy in transmission mode and magneto-optical Kerr (MOKE) microscopy. Annealing at 673 K is found to result in crystallization. From the Mossbauer measurements it is observed that the Fe magnetic moments are in the plane of sample for as-cast ribbon; α-FeCo, (Fe{sub 0.5}Co{sub 0.5}){sub 2}B and Fe{sub 2}B phases are formed after crystallization. MOKE microscopy revealed that wide 180° domain walls & narrow fingerprint domains are observed before crystallization and fine domains are observed after crystallization. The results are explained in terms of the presence of internal stresses and their annealing with thermal heat treatment.

  3. Ribbon scanning confocal for high-speed high-resolution volume imaging of brain.

    Directory of Open Access Journals (Sweden)

    Alan M Watson

    Full Text Available Whole-brain imaging is becoming a fundamental means of experimental insight; however, achieving subcellular resolution imagery in a reasonable time window has not been possible. We describe the first application of multicolor ribbon scanning confocal methods to collect high-resolution volume images of chemically cleared brains. We demonstrate that ribbon scanning collects images over ten times faster than conventional high speed confocal systems but with equivalent spectral and spatial resolution. Further, using this technology, we reconstruct large volumes of mouse brain infected with encephalitic alphaviruses and demonstrate that regions of the brain with abundant viral replication were inaccessible to vascular perfusion. This reveals that the destruction or collapse of large regions of brain micro vasculature may contribute to the severe disease caused by Venezuelan equine encephalitis virus. Visualization of this fundamental impact of infection would not be possible without sampling at subcellular resolution within large brain volumes.

  4. Exchange bias behavior in Ni{sub 50.0}Mn{sub 35.5} In{sub 14.5} ribbons annealed at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, T. [Dept. de Fisica, Universidad de Oviedo, Calvo Sotelo s/n, 33007 Oviedo (Spain); Sato Turtelli, R.; Groessinger, R. [Institut fur Festkoerperphysik, Technische Universitaet Wien, Wiedner Hauptstr. 8-10, 1040 Vienna (Austria); Sanchez, M.L.; Santos, J.D.; Rosa, W.O.; Prida, V.M. [Dept. de Fisica, Universidad de Oviedo, Calvo Sotelo s/n, 33007 Oviedo (Spain); Escoda, Ll.; Sunol, J.J. [Campus de Montilivi, Universidad de Girona, edifici PII, Lluis Santalo s/n. 17003 Girona (Spain); Koledov, V. [Kotelnikov Institute of Radio Engineering and Electronics, RAS, Moscow 125009 (Russian Federation); Hernando, B., E-mail: grande@uniovi.es [Dept. de Fisica, Universidad de Oviedo, Calvo Sotelo s/n, 33007 Oviedo (Spain)

    2012-10-15

    Heusler alloy Ni{sub 50.0}Mn{sub 35.5}In{sub 14.5} ribbons were prepared by melt-spinning technique. Several short time annealings were carried out in order to enhance the exchange bias effect in this alloy ribbon. The magnetic transition temperature increases with the annealing, compared to the as-spun sample, however no significant differences in respective Curie temperatures were observed for austenite and martensite phases in such annealed samples. Exchange bias effect is observed at low temperatures for all samples and practically vanishes at 60 K for the as-spun sample, whereas for the annealed ribbons it vanishes at 100 K.

  5. SEAL FOR HIGH SPEED CENTRIFUGE

    Science.gov (United States)

    Skarstrom, C.W.

    1957-12-17

    A seal is described for a high speed centrifuge wherein the centrifugal force of rotation acts on the gasket to form a tight seal. The cylindrical rotating bowl of the centrifuge contains a closure member resting on a shoulder in the bowl wall having a lower surface containing bands of gasket material, parallel and adjacent to the cylinder wall. As the centrifuge speed increases, centrifugal force acts on the bands of gasket material forcing them in to a sealing contact against the cylinder wall. This arrangememt forms a simple and effective seal for high speed centrifuges, replacing more costly methods such as welding a closure in place.

  6. The cool seal system: a practical solution to the shaft seal problem and heat related complications with implantable rotary blood pumps.

    Science.gov (United States)

    Yamazaki, K; Mori, T; Tomioka, J; Litwak, P; Antaki, J F; Tagusari, O; Koyanagi, H; Griffith, B P; Kormos, R L

    1997-01-01

    A critical issue facing the development of an implantable, rotary blood pump is the maintenance of an effective seal at the rotating shaft. Mechanical seals are the most versatile type of seal in wide industrial applications. However, in a rotary blood pump, typical seal life is much shorter than required for chronic support. Seal failure is related to adhesion and aggregation of heat denatured blood proteins that diffuse into the lubricating film between seal faces. Among the blood proteins, fibrinogen plays an important role due to its strong propensity for adhesion and low transition temperature (approximately 50 degrees C). Once exposed to temperature exceeding 50 degrees C, fibrinogen molecules fuse together by multi-attachment between heat denatured D-domains. This quasi-polymerized fibrin increases the frictional heat, which proliferates the process into seal failure. If the temperature of the seal faces is maintained well below 50 degrees C, a mechanical seal would not fail in blood. Based on this "Cool-Seal" concept, we developed a miniature mechanical seal made of highly thermally conductive material (SiC), combined with a recirculating purge system. A large supply of purge fluid is recirculated behind the seal face to augment convective heat transfer to maintain the seal temperature below 40 degrees C. It also cools all heat generating pump parts (motor coil, bearing, seal). The purge consumption has been optimized to virtually nil (seal system has now been incorporated into our intraventricular axial flow blood pump (IVAP) and newly designed centrifugal pump. Ongoing in vivo evaluation of these systems has demonstrated good seal integrity for more than 160 days. The Cool-Seal system can be applied to any type of rotary blood pump (axial, diagonal, centrifugal, etc.) and offers a practical solution to the shaft seal problem and heat related complications, which currently limit the use of implantable rotary blood pumps.

  7. 3D Anisotropy of Solar Wind Turbulence, Tubes, or Ribbons?

    Science.gov (United States)

    Verdini, Andrea; Grappin, Roland; Alexandrova, Olga; Lion, Sonny

    2018-01-01

    We study the anisotropy with respect to the local magnetic field of turbulent magnetic fluctuations at magnetofluid scales in the solar wind. Previous measurements in the fast solar wind obtained axisymmetric anisotropy, despite that the analysis method allows nonaxisymmetric structures. These results are probably contaminated by the wind expansion that introduces another symmetry axis, namely, the radial direction, as indicated by recent numerical simulations. These simulations also show that while the expansion is strong, the principal fluctuations are in the plane perpendicular to the radial direction. Using this property, we separate 11 yr of Wind spacecraft data into two subsets characterized by strong and weak expansion and determine the corresponding turbulence anisotropy. Under strong expansion, the small-scale anisotropy is consistent with the Goldreich & Sridhar critical balance. As in previous works, when the radial symmetry axis is not eliminated, the turbulent structures are field-aligned tubes. Under weak expansion, we find 3D anisotropy predicted by the Boldyrev model, that is, turbulent structures are ribbons and not tubes. However, the very basis of the Boldyrev phenomenology, namely, a cross-helicity increasing at small scales, is not observed in the solar wind: the origin of the ribbon formation is unknown.

  8. First-order reversal curve analysis in the hysteretic behavior of boron-rich nanocomposite Nd-Fe-B ribbons

    International Nuclear Information System (INIS)

    Saccone, F.D.; Pampillo, L.G.; Oliva, M.I.; Bercoff, P.G.; Bertorello, H.R.; Sirkin, H.R.M.

    2007-01-01

    Structural and magnetic properties of melt-spun Nd 4.5 Fe 72 Co 3 Cr 2 Al 1 B 17.5 ribbons were studied by means of differential scanning calorimetry, Moessbauer effect spectroscopy, X-ray diffraction and first-order reversal curve distributions. The presence of a solid solution (Fe, Co) in ribbons annealed at 685 C for 10 min was detected from Moessbauer spectra. Correlations between the observed structural changes at higher annealing temperatures and modifications in the interaction fields of precipitated phases are discussed

  9. Miniature magnetic fluid seal working in liquid environments

    Energy Technology Data Exchange (ETDEWEB)

    Mitamura, Yoshinori, E-mail: ymitamura@par.odn.ne.jp [Graduate School of Information Science and Technology, Hokkaido University, Sapporo 060-0814 (Japan); Durst, Christopher A., E-mail: chris@procyrion.com [Procyrion, Inc., Houston, TX 77027 (United States)

    2017-06-01

    This study was carried out to develop a miniature magnetic fluid (MF) seal working in a liquid environment. The miniature MF seal is intended for use in a catheter blood pump. The requirements for the MF seal included a size of less than Ø4×4.5 mm, shaft diameter of 1 mm, sealing pressure of 200 mmHg, shaft speed of up to 40000 rpm, and life of one month. The miniature MF seal was composed of an NdFeB magnet (Ø4×Ø2×1) sandwiched between two pole pieces (Ø4×Ø1.1×0.5). A shield (Ø4×Ø1.2×1.5) was placed on the pole piece facing the liquid to minimize the influence of pump flow on the MF. The seal was installed on a Ø1 shaft. A seal was formed by injecting MF (Ms: 47.8 kA/m and η: 0.5 Pa·sec) into the gap between the pole pieces and the shaft. Total volume of the MF seal was 44 μL. A sealing pressure of 370 mmHg was obtained at motor speeds of 0-40,000 rpm. The seal remained perfect for 10 days in saline under the condition of a pump flow of 1.5 L/min (The test was terminated in accordance with plans). The seal remained intact after ethylene oxide sterilization during which the seal was exposed to high pressures. In conclusion, the newly developed MF seal will be useful for a catheter pump. - Highlights: • A miniature magnetic fluid seal working in a liquid environment was developed. • The seal can be installed on Ø1 mm shaft and can seal against 370 mmHg at 40000 rpm. • The magnetic fluid seal will be useful for a catheter blood pump.

  10. Design analysis of a self-acting spiral-groove ring seal for counter-rotating shafts. [o ring seals

    Science.gov (United States)

    Dirusso, E.

    1983-01-01

    A self-acting spiral groove inter-shaft ring seal of nominal 16.33 cm (6.43 in.) diameter for sealing fan bleed air between counter rotating shafts in advanced turbofan engines was analyzed. The analysis focused on the lift force characteristics of the spiral grooves. A NASA Lewis developed computer program for predicting the performance of gas lubricated face seals was used to optimize the spiral groove geometry to produce maximum lift force. Load capacity curves (lift force as function of film thickness) were generated for four advanced turbofan engine operating conditions at relative seal speeds ranging from 17,850 to 29,800 rpm, sealed air pressures from 6 to 42 N/sq cm (9 to 60 psi) absolute and temperatures from 95 to 327 C (203 to 620 F). The relative seal sliding speed range was 152 to 255 m/sec (500 to 836 ft/sec). The analysis showed that the spiral grooves are capable of producing sufficient lift force such that the ring seal will operate in a noncontacting mode over the operating range of typical advanced turbofan engines.

  11. Seal Apparatus and Methods to Manufacture Thereof

    Science.gov (United States)

    Richard, James A. (Inventor)

    2013-01-01

    In some implementations, apparatus and methods are provided through which a dynamic cryogenic seal is manufactured. In some implementations, the seal includes a retainer and a spring-seal assembly, the assembly being comprised of a main spring housing and fluorine-containing polymer seals. In some implementations, either a radial seal, or an axial (or "piston seal") is provided. In some implementations, methods of manufacturing the dynamic cryogenic seal are also provided. In some implementations, the methods include assembling the components while either heated or cooled, taking advantage of thermal expansion and contraction, such that there is a strong interference fit between the components at room temperature. In some implementations, this process ensures that the weaker fluorine-containing polymer seal is forced to expand and contract with the stronger retainer and spring and is under constant preload. In some implementations, the fluorine-containing polymer is therefore fluidized and retained, and can not lift off.

  12. A dynamic analysis of rotary combustion engine seals

    Science.gov (United States)

    Knoll, J.; Vilmann, C. R.; Schock, H. J.; Stumpf, R. P.

    1984-01-01

    Real time work cell pressures are incorporated into a dynamic analysis of the gas sealing grid in Rotary Combustion Engines. The analysis which utilizes only first principal concepts accounts for apex seal separation from the crochoidal bore, apex seal shifting between the sides of its restraining channel, and apex seal rotation within the restraining channel. The results predict that apex seals do separate from the trochoidal bore and shift between the sides of their channels. The results also show that these two motions are regularly initiated by a seal rotation. The predicted motion of the apex seals compares favorably with experimental results. Frictional losses associated with the sealing grid are also calculated and compare well with measurements obtained in a similar engine. A comparison of frictional losses when using steel and carbon apex seals has also been made as well as friction losses for single and dual side sealing.

  13. Mechanical seal having a double-tier mating ring

    Science.gov (United States)

    Khonsari, Michael M.; Somanchi, Anoop K.

    2005-09-13

    An apparatus and method to enhance the overall performance of mechanical seals in one of the following ways: by reducing seal face wear, by reducing the contact surface temperature, or by increasing the life span of mechanical seals. The apparatus is a mechanical seal (e.g., single mechanical seals, double mechanical seals, tandem mechanical seals, bellows, pusher mechanical seals, and all types of rotating and reciprocating machines) comprising a rotating ring and a double-tier mating ring. In a preferred embodiment, the double-tier mating ring comprises a first and a second stationary ring that together form an agitation-inducing, guided flow channel to allow for the removal of heat generated at the seal face of the mating ring by channeling a coolant entering the mating ring to a position adjacent to and in close proximity with the interior surface area of the seal face of the mating ring.

  14. Development of the seal for nuclear material

    International Nuclear Information System (INIS)

    Lu Feng; Lu Zhao; Zhao Yonggang; Zhang Qixin; Xiao Xuefu

    2000-01-01

    Two kinds of double cap metallic seal and an adhesive seal are developed for the purpose of the accounting for and control of nuclear material. Two kinds of double cap metallic seal are made of stainless steel and copper, respectively and the self-locked technique is used. The number and the random pattern are carved out side and in side of a cap, respectively, for the seal. The random pattern carved inside of a cap for seal is taken a picture using numeral camera and memorized in computer. Special software is developed for verification of the random pattern memorized in computer. The adhesive seal is made of special adhesive paper for purpose of security, and a special pattern guarded against falsification is printed on seal paper using ultraviolet fluorescent light technique

  15. Numerical Study of the influence of a ribbon geometry of experiment on measuring particle angular distributions

    International Nuclear Information System (INIS)

    Artemov, A.S.

    1996-01-01

    The values and nature of systematic errors in small-angle particle scattering experiments using ribbon-like beams are investigated by numerical simulation. As shown, the extent of the influence of a ribbon geometry of experiment on the result of measurement is significantly dependent on the shape of the measured angular distribution in an elementary act of interaction. The algorithm of experimental material treatment, obtained in measuring the widths at half maximum of the angular differential cross sections of secondary particles, is presented using an example of specific distributions and certain experimental setup. (author). 12 refs., 7 figs

  16. The mechanics of Ribbons and Möbius bands

    CERN Document Server

    Fried, Eliot

    2016-01-01

    Recent developments in biology and nanotechnology have stimulated a rapidly growing interest in the mechanics of thin, flexible ribbons and Mobius bands. This edited volume contains English translations of four seminal papers on this topic, all originally written in German; of these, Michael A. Sadowsky published the first in 1929, followed by two others in 1930, and Walter Wunderlich published the last in 1962. The volume also contains invited, peer-reviewed, original research articles on related topics. Previously published in the Journal of Elasticity, Volume 119, Issue 1-2, 2015.

  17. Magnetoband structures of AB-stacked zigzag nanographite ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.P.; Chiu, C.W.; Shyu, F.L.; Chen, R.B.; Lin, M.F

    2002-12-30

    Magnetoband structures of AB-stacked zigzag nanographite ribbons are studied by the tight-binding model. The magnetic field changes band width, energy space, and energy dispersions (the produce of Landau subbands and Landau levels). It causes many zero energy points. Such points and corresponding localized states are studied in detail. There are certain important differences between localized states and edge states. Oscillation period of Landau subbands are determined by these points. The interribbon interactions also affect magnetoband structures, such as energy dispersions, band width, oscillation period of Landau subbands, and flux dependence of Hofstadter butterflies.

  18. Innovation to reality for improved pump seal performance

    International Nuclear Information System (INIS)

    Wong, W.; Eyvindson, A.; Rhodes, D.B.

    2003-01-01

    'Full-Text:' The nuclear industry requires reliable pump seals. Extended operating conditions for aging plants (i.e., low pressure starts, pressure and temperature transients) and increasing demands from new plants (larger sizes, higher speeds) are pushing the operating envelope for seals. This means that many seals that were previously considered adequate are now requiring increased attention and care. Operating utilities have taken different approaches to addressing their existing, or emerging, seal problems. Primary concerns include maintenance practices, seal design, and monitoring capabilities, as well as operating conditions, transients, pump and motor design. Success in this area requires ongoing dialogue among the station operators, pump manufacturers and seal designers. Regardless of the design, the basic requirement in CANDU is a reliable seal lifetime exceeding 5 years. This paper describes AECL's efforts to meet this requirement through an ongoing program of research and development in seal technology. Current work includes rigorous testing and evaluation of new seal materials and coatings to maximize seal stability and minimize friction and wear (i.e., pressure/temperature transients produce unpredictable shaft movement that can significantly alter face deflections affecting leak rates and seal stability, and sometimes cause the seal to hang-up and de-stage). Also required is a practical method for on-line monitoring of the condition of the seal, whether it is newly installed or after several years of reliable performance. This provides crucial information for inventory, maintenance and outage planning. While new concepts may look good on paper, it is only after they have been demonstrated under fully representative station operating conditions that they can truly be considered ready for field use. AECL CAN-seals lead the nuclear industry in reliability and seal life. They effectively save operators millions of dollars in outage time and person

  19. Innovative Seals for Solid Oxide Fuel Cells (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Raj

    2008-06-30

    A functioning SOFC requires different type of seals such as metal-metal, metal-ceramic, and ceramic-ceramic. These seals must function at high temperatures between 600--900{sup o}C and in oxidizing and reducing environments of the fuels and air. Among the different type of seals, the metal-metal seals can be readily fabricated using metal joining, soldering, and brazing techniques. However, the metal-ceramic and ceramic-ceramic seals require significant research and development because the brittle nature of ceramics/glasses can lead to fracture and loss of seal integrity and functionality. Consequently, any seals involving ceramics/glasses require a significant attention and technology development for reliable SOFC operation. This final report is prepared to describe the progress made in the program on the needs, approaches, and performance of high temperature seals for SOFC. In particular, a new concept of self-healing glass seals is pursued for making seals between metal-ceramic material combinations, including some with a significant expansion mismatch.

  20. Corrosion-resistant amorphous alloy ribbons for electromagnetic filtration of iron rusts from water

    International Nuclear Information System (INIS)

    Kawashima, Asahi; Asami, Katsuhiko; Sato, Takeaki; Hashimoto, Koji

    1985-01-01

    An attempt was made to use corrosion-resistant amorphous Fe-9Cr-13P-7C alloy ribbons as an electromagnetic filter material for trapping various iron rusts suspended in water at 40 0 C. The ferrimagnetic Fe 3 O 4 rust was trapped with the 100 % efficiency and paramagnetic rusts such as α-Fe 2 O 3 , α-FeOOH and amorphous ferric oxyhydroxide were trapped with certain efficiencies at the magnetic field strength of 0.5-10 kOe. The regeneration of the filter by back-washing was easy. The trapping capacity of electromagnetic filter was proportional to the edge length of the filter material where the high magnetic field strength existed. Therefore, melt-spun thin and narrow amorphous alloy ribbons having the high corrosion resistance have the potential utility as electromagnetic filter material. (author)

  1. The influence of API concentration on the roller compaction process: modeling and prediction of the post compacted ribbon, granule and tablet properties using multivariate data analysis.

    Science.gov (United States)

    Boersen, Nathan; Carvajal, M Teresa; Morris, Kenneth R; Peck, Garnet E; Pinal, Rodolfo

    2015-01-01

    While previous research has demonstrated roller compaction operating parameters strongly influence the properties of the final product, a greater emphasis might be placed on the raw material attributes of the formulation. There were two main objectives to this study. First, to assess the effects of different process variables on the properties of the obtained ribbons and downstream granules produced from the rolled compacted ribbons. Second, was to establish if models obtained with formulations of one active pharmaceutical ingredient (API) could predict the properties of similar formulations in terms of the excipients used, but with a different API. Tolmetin and acetaminophen, chosen for their different compaction properties, were roller compacted on Fitzpatrick roller compactor using the same formulation. Models created using tolmetin and tested using acetaminophen. The physical properties of the blends, ribbon, granule and tablet were characterized. Multivariate analysis using partial least squares was used to analyze all data. Multivariate models showed that the operating parameters and raw material attributes were essential in the prediction of ribbon porosity and post-milled particle size. The post compacted ribbon and granule attributes also significantly contributed to the prediction of the tablet tensile strength. Models derived using tolmetin could reasonably predict the ribbon porosity of a second API. After further processing, the post-milled ribbon and granules properties, rather than the physical attributes of the formulation were needed to predict downstream tablet properties. An understanding of the percolation threshold of the formulation significantly improved the predictive ability of the models.

  2. Novel hydrated graphene ribbon unexpectedly promotes aged seed germination and root differentiation

    Science.gov (United States)

    Hu, Xiangang; Zhou, Qixing

    2014-01-01

    It is well known that graphene (G) induces nanotoxicity towards living organisms. Here, a novel and biocompatible hydrated graphene ribbon (HGR) unexpectedly promoted aged (two years) seed germination. HGR formed at the normal temperature and pressure (120 days hydration), presented 17.1% oxygen, 0.9% nitrogen groups, disorder-layer structure, with 0.38 nm thickness ribbon morphology. Interestingly, there were bulges around the edges of HGR. Compared to G and graphene oxide (GO), HGR increased seed germination by 15% root differentiation between 52 and 59% and enhanced resistance to oxidative stress. The metabonomics analysis discovered that HGR upregulated carbohydrate, amino acid, and fatty acids metabolism that determined secondary metabolism, nitrogen sequestration, cell membrane integrity, permeability, and oxidation resistance. Hexadecanoic acid as a biomarker promoted root differentiation and increased the germination rate. Our discovery is a novel HGR that promotes aged seed germination, illustrates metabolic specificity among graphene-based materials, and inspires innovative concepts in the regulation of seed development.

  3. 21 CFR 864.9750 - Heat-sealing device.

    Science.gov (United States)

    2010-04-01

    ... and Blood Products § 864.9750 Heat-sealing device. (a) Identification. A heat-sealing device is a device intended for medical purposes that uses heat to seal plastic bags containing blood or blood... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Heat-sealing device. 864.9750 Section 864.9750...

  4. First-order reversal curve analysis in the hysteretic behavior of boron-rich nanocomposite Nd-Fe-B ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Saccone, F.D. [Laboratorio de Solidos Amorfos, Departamento de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires (Argentina) and CONICET (Argentina)]. E-mail: fsaccon@fi.uba.ar; Pampillo, L.G. [Laboratorio de Solidos Amorfos, Departamento de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires (Argentina); Oliva, M.I. [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba (Argentina); CONICET (Argentina); Bercoff, P.G. [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba (Argentina); CONICET (Argentina); Bertorello, H.R. [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba (Argentina); CONICET (Argentina); Sirkin, H.R.M. [Laboratorio de Solidos Amorfos, Departamento de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires (Argentina); CONICET (Argentina)

    2007-09-01

    Structural and magnetic properties of melt-spun Nd{sub 4.5}Fe{sub 72}Co{sub 3}Cr{sub 2}Al{sub 1}B{sub 17.5} ribbons were studied by means of differential scanning calorimetry, Moessbauer effect spectroscopy, X-ray diffraction and first-order reversal curve distributions. The presence of a solid solution (Fe, Co) in ribbons annealed at 685 C for 10 min was detected from Moessbauer spectra. Correlations between the observed structural changes at higher annealing temperatures and modifications in the interaction fields of precipitated phases are discussed.

  5. Refurbishing the seals of the H2S compressors in the isotopic exchange installations at the Heavy Water Reprocessing Plant. Technical solutions for replacing liquid seals by dry seals

    International Nuclear Information System (INIS)

    Panait; Adrian; Serban, Viorel; Androne, Marian; Florea, Ioana; Ciocan, George; State, Elena

    2004-01-01

    An analysis of the present sealing system in the H 2 S compressors showed that the risk of accidental hydrogen sulfide escape into the atmosphere is high in case of a seal oil pressure loss. At the same time there exist drawbacks occurring even in normal regime of functioning among which one can mention: - relatively high losses of oil occur, part of the oil being carried away by the compressors and released into the isotopic exchange columns where the water counter current flow produces a foaming that reduces the column processing capacity; - part of the sealing oil leaks reaches the final product, the heavy water, where from it must be removed by chemical procedures; - the installations adjacent to the sealing system are relatively sophisticated and require relatively high expenses for exploitation and maintenance. The classical sealing systems using sealing rings, sleeves, labyrinths, etc, cannot be used since their safe working range is exceeded due to either driving shaft rotational speed, or to the increase of its diameter, or else to an increase of the speed of motion of moving parts relative to the fix parts. The sealing systems with magnetic liquids are rather sophisticated and expensive while in case of electric supply loss they are completely unsafe, because their sealing capacity vanishes. The materials used for sealing gaskets limit their application only to the cases when the relative motion of the moving pieces is low or vanishing what happens only at shut down or failure situations. To prevent these drawbacks of the present seal system in the H 2 S compressors of the isotopic exchange columns and having in view the limitations of the currently used sealing systems a new system of sealing was conceived and designed on the basis of the patent titled 'Sealing Installation and Procedure' recorded by OSIM under No. A/0315/10.04.2003. The new system can be built as a single or double stage each of them having in turn a dynamic and a static sub-stage. The

  6. Improved cryogenic shaft seals

    Science.gov (United States)

    Gillon, W. A., Jr.; Tellier, G. F.

    1976-01-01

    Seals are designed for use with liquid propellant ball valves at temperatures ranging from -400 F to 130 F and 8,000 psig. Seals are capable of sustaining 90 degree rotation, with substantial amount of lateral and axial play, caused by large pressure loads and differential thermal contraction.

  7. Face-Sealing Butterfly Valve

    Science.gov (United States)

    Tervo, John N.

    1992-01-01

    Valve plate made to translate as well as rotate. Valve opened and closed by turning shaft and lever. Interactions among lever, spring, valve plate, and face seal cause plate to undergo combination of translation and rotation so valve plate clears seal during parts of opening and closing motions.

  8. Spray sealing: A breakthrough in integral fuel tank sealing technology

    Science.gov (United States)

    Richardson, Martin D.; Zadarnowski, J. H.

    1989-11-01

    In a continuing effort to increase readiness, a new approach to sealing integral fuel tanks is being developed. The technique seals potential leak sources by spraying elastomeric materials inside the tank cavity. Laboratory evaluations project an increase in aircraft supportability and reliability, an improved maintainability, decreasing acquisition and life cycle costs. Increased usable fuel volume and lower weight than conventional bladders improve performance. Concept feasibility was demonstrated on sub-scale aircraft fuel tanks. Materials were selected by testing sprayable elastomers in a fuel tank environment. Chemical stability, mechanical properties, and dynamic durability of the elastomer are being evaluated at the laboratory level and in sub-scale and full scale aircraft component fatigue tests. The self sealing capability of sprayable materials is also under development. Ballistic tests show an improved aircraft survivability, due in part to the elastomer's mechanical properties and its ability to damp vibrations. New application equipment, system removal, and repair methods are being investigated.

  9. Magnetically Actuated Seal, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — FTT proposes development of a magnetically actuated dynamic seal. Dynamic seals are used throughout the turbopump in high-performance, pump-fed, liquid rocket...

  10. Magnetically Actuated Seal, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — FTT proposes development of a magnetically actuated dynamic seal. Dynamic seals are used throughout the turbopump in high-performance, pump-fed, liquid rocket...

  11. Guide to optimized replacement of equipment seals

    International Nuclear Information System (INIS)

    Gleason, J.F.

    1990-03-01

    A reevaluation of current scheduled replacement intervals of polymeric seals in plant equipment can achieve significant benefits. Information is provided which has the potential for increasing replacement intervals based on better information on how seals have performed through unique nuclear industry tests to qualify equipment, improved elastomers and increased knowledge of the failure mechanisms and related performance. The research was performed by reviewing applications of elastomeric seals in nuclear plants and practice associated with defining seal replacement intervals in the nuclear power and other industries. Performance indicators and how they predict degradation of seals were evaluated. Guidelines and a flow chart for reevaluating seal replacement intervals are provided. 29 refs., 38 figs., 8 tabs

  12. Analysis of end-face seals by FEM

    Directory of Open Access Journals (Sweden)

    Juraszek J.

    2002-09-01

    Full Text Available The end face-seals joint simultaneously the function of seal, bearing and heat exchanger. In order to improve the design of end-face seals the analysis of this type of joint by means of finite element method, was developed. The temperature distribution is indispensable to the analysis of displacement and stress in this type of face seal. In this work the values of temperature and stress in end-face seals were calculated. The numerical results were confirmed by measurements in the laboratory.

  13. HRTEM and neutron diffraction study of LixMo5O17: From the ribbon (x=5) structure to the rock salt (x=12) structure

    International Nuclear Information System (INIS)

    Lebedev, O.I.; Caignaert, V.; Raveau, B.; Pop, N.; Gozzo, F.; Van Tendeloo, G.; Pralong, V.

    2011-01-01

    Structure determination of the fully intercalated phase Li 12 Mo 5 O 17 and of the deintercalated oxide Li 5 Mo 5 O 17 has been carried out by electron microscopy and neutron powder diffraction. The reversible topotactic transformation between the ordered rock salt structure of the former and the ribbon structure of the latter (closely related to that of Li 4 Mo 5 O 17 ) is explained on the following basis: both structures can be described as strips built up as an assembly of infinite ribbons of MoO 6 octahedra that are five octahedra thick, and that differ by slight displacements of the octahedral ribbons. We show that the electrochemical behavior of the Li x Mo 5 O 17 system is based on two sorts of Li + sites; those that are located within the strips between the ribbons, and those that are located at the border of the strips. The high rate of Li intercalation in this oxide and its reversibility are discussed in terms of its peculiar structure. -- Graphical abstract: Structure determination of the fully intercalated phase Li 12 Mo 5 O 17 and of the deintercalated oxide Li 5 Mo 5 O 17 has been carried out by electron microscopy and neutron powder diffraction. The reversible topotactic transformation between the ordered rock salt structure of the former and the ribbon structure of the latter is explained on the following basis: both structures can be described as strips built up as an assembly of infinite ribbons of MoO 6 octahedra that are five octahedra thick, and that differ by slight displacements of the octahedral ribbons. We show that the electrochemical behavior of the Li x Mo 5 O 17 system is based on two sorts of Li + sites; those that are located within the strips between the ribbons, and those that are located at the border of the strips. The high rate of Li intercalation in this oxide and its reversibility are discussed in terms of its peculiar structure. Research highlights: → Electron microscopy and neutron powder diffraction structure determination

  14. Sealing device and method for sealing fractures or leaks in wall or formation surrounding tube-shaped channel

    DEFF Research Database (Denmark)

    2014-01-01

    The sealing device (1) includes an elongated body (5) adapted to be introduced into a tube-shaped channel (2) and including a sealing fluid placement section (6) arranged between a first and a second annular flow barrier (7, 8). The elongated body further includes a sealing fluid activation secti...

  15. {gamma}-Fe phase plasma-induced on the surface of thin S3A alloy ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Cabral-Prieto, A., E-mail: agustin.cabral@inin.gob.mx; Garcia-Sosa, I., E-mail: irma.garcia@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares, Departamento de Quimica (Mexico); Nava, N., E-mail: tnava@imp.mx [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas (Mexico); Camps, E., E-mail: enrique.camps@inin.gob.mx; Escobar, Luis, E-mail: luis.escobar@inin.gov.mx [Instituto Nacional de Investigaciones Nucleares, Departamento de Quimica (Mexico); Lopez-Castanarez, R., E-mail: rlc@anuies.mx; Olea-Cardoso, O., E-mail: olc@anuies.mx [Universidad Autonoma del Edo. de Mexico, Facultad de Quimica (Mexico)

    2011-11-15

    Amorphous alloy ribbons of Fe{sub 77}Cr{sub 2}B{sub 16}Si{sub 5} were exposed to cold plasmas of N{sub 2} and Ar-N{sub 2} at temperatures lower than T{sub x} = 808 K. The conversion X-ray Moessbauer spectra of the plasma-exposed ribbons consist of a singlet and a broadened magnetic sextet. The singlet with isomer shift {delta} = -0.11 mm/s can be assigned to {gamma}-Fe austenite phase. Minor bulk magnetic changes in the alloy were measured as a consequence of these treatments; e.g. the relative intensities A23 of the transmission Moessbauer spectra of the untreated and treated samples, were 3.22 and 3.56, respectively, the B{sub hf} values changed from 22.9 T (untreated sample) to 22.4 T (plasma treated samples). Unexpectedly, the {gamma}-Fe phase can also be produced by simply heating the alloy ribbons under N{sub 2} flux at temperatures as low as 423 K. Moessbauer data of the crystallized samples are also reported, and a qualitative assessment on the mechanical properties of the Fe{sub 77}Cr{sub 2}B{sub 16}Si{sub 5} alloy associated with the plasma and/or temperature surface induced {gamma}-Fe phase is given.

  16. Quick-sealing design for radiological containment

    International Nuclear Information System (INIS)

    Rampdla, D.S.; Speer, E.

    1991-01-01

    This patent describes a quick-sealing assembly and method for forming an adhesive seal on opposite sides of a mechanical seal for a flexible containment bag of the type used for working with radioactively contaminated objects. The assembly includes an elongated mechanical fastener having opposing engaging members affixed at a predetermined distance from each of the elongated edges, with an adhesive layer formed between the mechanical fastener and the elongated edge such that upon engagement of the mechanical fastener and adhesive layers to opposing containment fabric, a neat triple hermetic seal is formed

  17. Quick-sealing design for radiological containment

    International Nuclear Information System (INIS)

    Rampolia, D.S.; Speer, E.

    1990-01-01

    This patent describes a quick-sealing assembly and method for forming an adhesive seal on opposite sides of a mechanical seal for a flexible containment bag of the type used for working with radioactively contaminated objects. The assembly includes an elongated mechanical fastener having opposing engaging members affixed at a predetermined distance from each of the elongated edges, with an adhesive layer formed between the mechanical fastener and the elongated edge such that upon engagement of the mechanical fastener and adhesive layers to opposing containment fabric, a neat triple hermetic seal is formed

  18. Quick-sealing design for radiological containment

    Science.gov (United States)

    Rampolia, Donald S.; Speer, Elmer

    1990-01-01

    A quick-sealing assembly and method for forming an adhesive seal on opposite sides of a mechanical seal for a flexible containment bag of the type used for working with radioactively contaminated objects. The assembly includes an elongated mechanical fastener having opposing engaging members affixed at a predetermined distance from each of the elongated edges, with an adhesive layer formed between the mechanical fastener and the elongated edge such that upon engagement of the mechanical fastener and adhesive layers to opposing containment fabric, a neat triple hermetic seal is formed.

  19. Auto-identification fiberoptical seal verifier

    International Nuclear Information System (INIS)

    Yamamoto, Yoichi; Mukaiyama, Takehiro

    1998-08-01

    An auto COBRA seal verifier was developed by Japan Atomic Energy Research Institute (JAERI) to provide more efficient and simpler inspection measures for IAEA safeguards. The verifier is designed to provide means of a simple, quantitative and objective judgment on in-situ verification for the COBRA seal. The equipment is a portable unit with hand-held weight and size. It can be operated by battery or AC power. The verifier reads a COBRA seal signature by using a built-in CCD camera and carries out the signature comparison procedure automatically on digital basis. The result of signature comparison is given as a YES/NO answer. The production model of the verifier was completed in July 1996. The development was carried out in collaboration with Mitsubishi Heavy Industries, Ltd. This report describes the design and functions of the COBRA seal verifier and the results of environmental and functional tests. The development of the COBRA seal verifier was carried out in the framework of Japan Support Programme for Agency Safeguards (JASPAS) as a project, JD-4 since 1981. (author)

  20. Vickers Microhardness and Hyperfine Magnetic Field Variations of Heat Treated Amorphous Fe{sub 78}Si{sub 9}B{sub 13} Alloy Ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Cabral-Prieto, A., E-mail: acpr@nuclear.inin.mx [Instituto Nacional de Investigaciones Nucleares, Department of Chemistry (Mexico); Garcia-Santibanez, F.; Lopez, A.; Lopez-Castanares, R.; Olea Cardoso, O. [Universidad Autonoma del Estado de Mexico, El Cerrillo Piedras Blancas, Facultad de Ciencias (Mexico)

    2005-02-15

    Amorphous Fe{sub 78}Si{sub 9}B{sub 13} alloy ribbons were heat treated between 296 and 763 K, using heating rates between 1 and 4.5 K/min. Whereas one ribbon partially crystallized at T{sub x} = 722 K, the other one partially crystallized at T{sub x} = 763 K. The partially crystallized ribbon at 722 K, heat treated using a triangular form for the heating and cooling rates, was substantially less fragile than the partially crystallized at 763 K where a tooth saw form for the heating and cooling rates was used. Vickers microhardness and hyperfine magnetic field values behaved almost concomitantly between 296 and 673 K. The Moessbauer spectral line widths of the heat-treated ribbons decreased continuously from 296 to 500 K, suggesting stress relief in this temperature range where the Vickers microhardness did not increase. At 523 K the line width decreased further but the microhardness increased substantially. After 523 K the line width behave in an oscillating form as well as the microhardness, indicating other structural changes in addition to the stress relief. Finally, positron lifetime data showed that both inner part and surface of Fe{sub 78}Si{sub 9}B{sub 13} alloy ribbons were affected distinctly. Variations on the surface may be the cause of some of the high Vickers microhardness values measured in the amorphous state.

  1. The use of dual material seals for packaging

    International Nuclear Information System (INIS)

    Temus, C.J.; Nichols, J.C.

    2004-01-01

    The use of dual material seals, metal and elastomeric for a transportation package, provides a viable option for packages requiring high temperature seal capability. Allowing the seal area to go to higher temperatures then allowed for all elastomeric seal reduce the necessity of providing thermal protection during a postulated accident condition fire. It also increases the options for impact limiting features that do not also mitigate the affects of accident thermal events. Typically, high temperature seals require the use of metal O-rings. Only one seal (typically identified as the containment seal) needs to survive the hypothetical accident conditions, including the high temperatures that may occur during the prescribed hypothetical thermal event. However, to expedite the assembly leakage rate testing of radioactive material packages, a dual O-ring seal arrangement is often used to allow creation of a relatively small volume test cavity between the seals. For any package that is being used on a frequent basis, the total cost of seals can be significantly reduced by using an elastomeric seal as the secondary seal. The elastomeric seal is not the containment boundary seal and does not need to survive the high temperature condition. To get the dual material O-ring seals to seat properly, a different approach has to be taken than with closure of a radioactive material package that does not use metallic O-ring(s). A metal O-ring requires an application of a seating force while the elastomeric package requires a certain percentage of deformation. This is further complicated when the seating force is developed using a multi-bolt closure. Because of the nature of multi-bolt closures, elastic interaction prevents the equal application of force. This paper develops the methods involved in properly closing and establishing containment when using dual material seals with a multi-bolt closure. These methods were demonstrated in two production casks requiring testing leak

  2. Sealing of boreholes using natural, compatible materials: Granular salt

    International Nuclear Information System (INIS)

    Finley, R.E.; Zeuch, D.H.; Stormont, J.C.; Daemen, J.J.K.

    1994-01-01

    Granular salt can be used to construct high performance permanent seals in boreholes which penetrate rock salt formations. These seals are described as seal systems comprised of the host rock, the seal material, and the seal rock interface. The performance of these seal systems is defined by the complex interactions between these seal system components through time. The interactions are largely driven by the creep of the host formation applying boundary stress on the seal forcing host rock permeability with time. The immediate permeability of these seals is dependent on the emplaced density. Laboratory test results suggest that careful emplacement techniques could results in immediate seal system permeability on the order of 10 -16 m 2 to 10 -18 m 2 (10 -4 darcy to 10 -6 ). The visco-plastic behavior of the host rock coupled with the granular salts ability to ''heal'' or consolidate make granular salt an ideal sealing material for boreholes whose permanent sealing is required

  3. HFCVD Diamond-Coated Mechanical Seals

    Directory of Open Access Journals (Sweden)

    Raul Simões

    2018-05-01

    Full Text Available A mechanical seal promotes the connection between systems or mechanisms, preventing the escape of fluids to the exterior. Nonetheless, due to extreme working conditions, premature failure can occur. Diamond, due to its excellent properties, is heralded as an excellent choice to cover the surface of these devices and extend their lifetime. Therefore, the main objective of this work was to deposit diamond films over mechanical seals and test the coated seals on a water pump, under real working conditions. The coatings were created by hot filament chemical vapor deposition (HFCVD and two consecutive layers of micro- and nanocrystalline diamond were deposited. One of the main difficulties is the attainment of a good adhesion between the diamond films and the mechanical seal material (WC-Co. Nucleation, deposition conditions, and pre-treatments were studied to enhance the coating. Superficial wear or delamination of the film was investigated using SEM and Raman characterization techniques, in order to draw conclusions about the feasibility of these coatings in the WC-Co mechanical seals with the purpose of increasing their performance and life time. The results obtained gave a good indication about the feasibility of this process and the deposition conditions used, with the mechanical seals showing no wear and no film delamination after a real work environment test.

  4. Laboratory studies of fluid flow through borehole seals

    International Nuclear Information System (INIS)

    South, D.L.

    1983-01-01

    Boreholes in the vicinity of a nuclear waste repository must be reliably sealed to prevent rapid migration of radionuclide contaminated water from the vicinity of the repository to the accessible environment. Few data currently exist regarding the effectiveness of borehole sealing. The objective of this research was to assess the performance of borehole seals under laboratory conditions, particularly with regard to varying stress fields. The approach used to evaluate borehole seals was to compare flow through a sealed borehole with flow through intact rock. Granite, basalt, and tuff were tested, using either cement or bentonite as the seal material. The main conclusions reached as a result of the experiments is that currently existing materials are capable of forming high quality seals when placed under laboratory conditions. Variation of triaxial stress state about a borehole does not significantly affect seal performance if the rock is stiffer than the seal material. Temperature/moisture variations (drying) degraded the quality of cement seals significantly. Performance partially recovered upon resaturation. Significant remaining questions include field emplacement techniques; field vertification of plug quality; plug performance over long time periods, particularly with respect to temperature/moisture variations and chemical stability; and radionuclide sorption capabilities. Scale effects are also important, as shafts and drifts must be sealed as well as larger diameter boreholes

  5. Miniature magnetic fluid seal working in liquid environments

    Science.gov (United States)

    Mitamura, Yoshinori; Durst, Christopher A.

    2017-06-01

    This study was carried out to develop a miniature magnetic fluid (MF) seal working in a liquid environment. The miniature MF seal is intended for use in a catheter blood pump. The requirements for the MF seal included a size of less than Ø4×4.5 mm, shaft diameter of 1 mm, sealing pressure of 200 mmHg, shaft speed of up to 40000 rpm, and life of one month. The miniature MF seal was composed of an NdFeB magnet (Ø4×Ø2×1) sandwiched between two pole pieces (Ø4×Ø1.1×0.5). A shield (Ø4×Ø1.2×1.5) was placed on the pole piece facing the liquid to minimize the influence of pump flow on the MF. The seal was installed on a Ø1 shaft. A seal was formed by injecting MF (Ms: 47.8 kA/m and η: 0.5 Pa·sec) into the gap between the pole pieces and the shaft. Total volume of the MF seal was 44 μL. A sealing pressure of 370 mmHg was obtained at motor speeds of 0-40,000 rpm. The seal remained perfect for 10 days in saline under the condition of a pump flow of 1.5 L/min (The test was terminated in accordance with plans). The seal remained intact after ethylene oxide sterilization during which the seal was exposed to high pressures. In conclusion, the newly developed MF seal will be useful for a catheter pump.

  6. Application of EIS to In Situ Characterization of Hydrothermal Sealing of Anodized Aluminum Alloys: Comparison between Hexavalent Chromium-Based Sealing, Hot Water Sealing and Cerium-Based Sealing

    OpenAIRE

    Carangelo, Anna; Curioni, Michele; Acquesta, Annalisa; Monetta, Tullio; Bellucci, Francesco

    2016-01-01

    Chromic acid anodizing has been used for almost a century to enhance corrosion protection of aerospace alloys. For some applications,hydrothermal sealing in hexavalent chromium-containing solution is required to enhance further the corrosion resistance but, due toenvironmental concerns, the use of hexavalent chromium must be discontinued. Good progress has been made to replace chromatesduring anodizing but comparatively less effort has focused on the sealing process. In this work, for the fir...

  7. Reactor coolant pump seal leakage monitoring

    International Nuclear Information System (INIS)

    Stevens, D.M.; Spencer, J.W.; Morris, D.J.; James, W.; Shugars, H.G.

    1986-01-01

    Problems with reactor coolant pump seals have historically accounted for a large percentage of unscheduled outages. Studies performed for the Electric Power Research Institute (EPRI) have shown that the replacement of coolant pump seals has been one of the leading causes of nuclear plant unavailability over the last ten years. Failures of coolant pump seals can lead to primary coolant leakage rates of 200-500 gallons per minute into the reactor building. Airborne activity and high surface contamination levels following these failures require a major cleanup effort and increases the time and personnel exposure required to refurbish the pump seals. One of the problems in assessing seal integrity is the inability to accurately measure seal leakage. Because seal leakage flow is normally very small, it cannot be sensed directly with normal flow instrumentation, but must be inferred from several other temperature and flow measurements. In operating plants the leakage rate has been quantified with a tipping-bucket gauge, a device which indicates when one quart of water has been accumulated. The tipping-bucket gauge has been used for most rainfall-intensity monitoring. The need for a more accurate and less expensive gauge has been addressed. They have developed a drop-counter precipitation sensor has been developed and optimized. The applicability of the drop-counter device to the problem of measuring seal leakage is being investigated. If a review of system specification and known drop-counter performance indicates that this method is feasible for measuring seal leak rates, a drop-counter gauge will be fabricated and tested in the laboratory. If laboratory tests are successful the gauge will be demonstrated in a pump test loop at Ontario Hydro and evaluated under simulated plant conditions. 3 references, 2 figures

  8. Numerical Investigation on Windback Seals Used in Aero Engines

    Directory of Open Access Journals (Sweden)

    Michael Flouros

    2018-01-01

    Full Text Available Seals are considered one of the most important flow elements in turbomachinery applications. The most traditional and widely known seal is the labyrinth seal but in recent years other types like the brush or carbon seals were introduced since they considerably reduce the sealing air consumption. When seals are used for sealing of aero engine bearing chambers they are subjected to high “bombardment” through oil particles which are present in the bearing chamber. These particles mainly result from the bearings as a consequence of the high rotational speeds. Particularly when carbon or brush seals are used, problems with carbon formation (coking may arise when oil gets trapped in the very tight gap of these seals. In order to prevent oil migration into the turbomachinery, particularly when the pressure difference over a seal is small or even negligible, significant improvement can be achieved through the introduction of so called windback seals. This seal has a row of static helical teeth (thread and below this thread a scalloped or smooth shaft section is rotating. Depending on the application, a windback seal can be used alone or as a combination with another seal (carbon, brush or labyrinth seal. A CFD analysis carried out with ANSYS CFX version 11 is presented in this paper with the aim to investigate this seal type. The simulations were performed by assuming a two-phase flow of air and oil in the bearing compartment. Design parameters like seal clearance, thread size, scallop width, were investigated at different operating conditions.

  9. Sealing Occlusal Dentin Caries in Permanent Molars

    DEFF Research Database (Denmark)

    Qvist, Vibeke; Borum, Mette Kit; Møller, Kirsten Dynes

    2017-01-01

    The purpose of this study was to investigate the possibility of postponing restorative intervention of manifest occlusal caries in young, permanent dentition by non-invasive sealing. This RCT-designed study included 521 occlusal lesions in 521 patients aged 6 to 17 y. Based on clinical and radiog......The purpose of this study was to investigate the possibility of postponing restorative intervention of manifest occlusal caries in young, permanent dentition by non-invasive sealing. This RCT-designed study included 521 occlusal lesions in 521 patients aged 6 to 17 y. Based on clinical...... longevity of sealings and restorations until retreatments, and 3) compare effectiveness of sealings and restorations to halt caries progression in sealed lesions and beneath restorations. Furthermore, we aimed to identify factors influencing longevity and the effectiveness of sealings and restorations.......001). The median survival time for sealings not replaced by restorations was 7.3 y (CI, 6.4 y to NA). Survival of sealings was increased in patients with low caries risk and/or excellent oral hygiene, second molars compared with first molars, and lesions not extending the middle one-third of the dentin. Survival...

  10. Floating seal system for rotary devices

    Science.gov (United States)

    Banasiuk, H.A.

    1983-08-23

    This invention relates to a floating seal system for rotary devices to reduce gas leakage around the rotary device in a duct and across the face of the rotary device to an adjacent duct. The peripheral seal bodies are made of resilient material having a generally U-shaped cross section wherein one of the legs is secured to a support member and the other of the legs forms a contacting seal against the rotary device. The legs of the peripheral seal form an extended angle of intersection of about 10[degree] to about 30[degree] in the unloaded condition to provide even sealing forces around the periphery of the rotary device. The peripheral seal extends around the periphery of the support member except where intersected by radial seals which reduce gas leakage across the face of the rotary device and between adjacent duct portions. The radial seal assembly is fabricated from channel bars, the smaller channel bar being secured to the divider of the support member and a larger inverted rigid floating channel bar having its legs freely movable over the legs of the smaller channel bar forming therewith a tubular channel. A resilient flexible tube is positioned within the tubular channel for substantially its full length to reduce gas leakage across the tubular channel. A spacer extends beyond the face of the floating channel near each end of the floating channel a distance to provide desired clearance between the floating channel and the face of the rotary device. 5 figs.

  11. Metal and elastomer seal tests for accelerator applications

    International Nuclear Information System (INIS)

    Welch, K.M.; McIntyre, G.T.; Tuozzolo, J.E.; Skelton, R.; Pate, D.J.; Gill, S.M.

    1989-01-01

    The vacuum system of the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory has more than a thousand metal vacuum seals. Also, numerous elastomer seals are used throughout the AGS to seal large beam component chambers. An accelerator upgrade program is being implemented to reduce the AGS operating pressure by x100 and improve the reliability of the vacuum system. This paper describes work in progress on metal and elastomer vacuum seals to help meet those two objectives. Tests are reported on the sealing properties of a variety of metal seals used on different sealing surfaces. Results are also given on reversible sorption properties of certain elastomers. 16 refs., 6 figs., 4 tabs

  12. Apparatus and method for inspecting a sealed container

    Science.gov (United States)

    Harmon, J Frank [Pocatello, ID; Jones, James L [Idaho Falls, ID; Hunt, Alan W [Pocatello, ID; Spaulding, Randy J [Pocatello, ID; Smith, Michael [Phoenix, AZ

    2009-03-24

    An apparatus for inspecting a sealed container is disclosed and which includes a pulsed electron accelerator which is positioned in spaced relation relative to a first side of the sealed container, and which produces a pulsed beam of photons which passes through the sealed container and any contents enclosed within the sealed container; a detector positioned in spaced relation relative to a second, opposite side of the sealed container, and which receives the pulsed beam of photons which passes through the contents of the sealed container, and which produces an output signal; and a computer for developing a visible image from the output signal of the detector which depicts the contents of the sealed container.

  13. Selection of vacuum seals for EBT-P

    International Nuclear Information System (INIS)

    Dillow, C.F.; Adlon, G.L.; Stubblefield, V.E.

    1981-01-01

    Elmo Bumpy Torus Proof of Principle (EBT-P) is a magnetic fusion RandD facility being constructed by McDonnell Douglas Astronautics Company - St. Louis Division of Oak Ridge National Laboratory (ORNL). EBT-P is a truly unique fusion device requiring careful consideration in selecting both the primary vacuum seals on the toroidal vessel and the secondary vacuum seals in components such as vacuum pumps and and valves. The vacuum seal environment is described and the considerations in vacuum seal selection fully discussed. Methods for protecting vacuum seals in pumps and valves from the microwave environments are also presented

  14. Seal analysis technology for reactor pressure vessel

    International Nuclear Information System (INIS)

    Zheng Liangang; Zhang Liping; Yang Yu; Zang Fenggang

    2009-01-01

    There is the coolant with radiation, high temperature and high pressure in the reactor pressure vessel (RPV). It is closely correlated to RPV sealing capability whether the whole nuclear system work well or not. The aim of this paper is to study the seal analysis method and technology, such as the pre-tensioning of the bolt, elastoplastic contact and coupled technology of thermal and structure. The 3 D elastoplastic seal analysis method really and generally consider the loads and model the contact problem with friction between the contact plates. This method is easier than the specialized seal program and used widely. And it is more really than the 2 D seal analysis method. This 3 D elastoplastic seal analysis method has been successfully used in the design and analysis of RPV. (authors)

  15. A Test of the Interstellar Boundary EXplorer Ribbon Formation in the Outer Heliosheath

    Energy Technology Data Exchange (ETDEWEB)

    Gamayunov, Konstantin V.; Rassoul, Hamid [Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, FL 32901 (United States); Heerikhuisen, Jacob, E-mail: kgamayunov@fit.edu [Department of Space Science, University of Alabama in Huntsville, Huntsville, AL 35899 (United States)

    2017-08-10

    NASA’s Interstellar Boundary EXplorer ( IBEX ) mission is imaging energetic neutral atoms (ENAs) propagating to Earth from the outer heliosphere and local interstellar medium (LISM). A dominant feature in all ENA maps is a ribbon of enhanced fluxes that was not predicted before IBEX . While more than a dozen models of the ribbon formation have been proposed, consensus has gathered around the so-called secondary ENA model. Two classes of secondary ENA models have been proposed; the first class assumes weak scattering of the energetic pickup protons in the LISM, and the second class assumes strong but spatially localized scattering. Here we present a numerical test of the “weak scattering” version of the secondary ENA model using our gyro-averaged kinetic model for the evolution of the phase-space distribution of protons in the outer heliosheath. As input for our test, we use distributions of the primary ENAs from our MHD-plasma/kinetic-neutral model of the heliosphere-LISM interaction. The magnetic field spectrum for the large-scale interstellar turbulence and an upper limit for the amplitude of small-scale local turbulence (SSLT) generated by protons are taken from observations by Voyager 1 in the LISM. The hybrid simulations of energetic protons are also used to set the bounding wavenumbers for the spectrum of SSLT. Our test supports the “weak scattering” version. This makes an additional solid step on the way to understanding the origin and formation of the IBEX ribbon and thus to improving our understanding of the interaction between the heliosphere and the LISM.

  16. Sealed radioactive sources toolkit

    International Nuclear Information System (INIS)

    Mac Kenzie, C.

    2005-09-01

    The IAEA has developed a Sealed Radioactive Sources Toolkit to provide information to key groups about the safety and security of sealed radioactive sources. The key groups addressed are officials in government agencies, medical users, industrial users and the scrap metal industry. The general public may also benefit from an understanding of the fundamentals of radiation safety

  17. Method and system to facilitate sealing in gas turbines

    Science.gov (United States)

    Morgan, Victor John; Foster, Gregory Thomas; Sarawate, Neelesh Nandkumar

    2017-09-12

    A method and system for sealing between components within a gas turbine is provided. A first recess defined in a first component receives a seal member. A second recess defined in a second component adjacent the first component also receives the seal member. The first and second recesses are located proximate a hot gas path defined through the gas turbine, and define circumferential paths about the turbine axis. The seal member includes a sealing face that extends in a direction substantially parallel to the turbine axis. The seal member also includes a plurality of seal layers, wherein at least one of the seal layers includes at least one stress relief region for facilitating flexing of the first seal member.

  18. Silicone foam for penetration seal

    International Nuclear Information System (INIS)

    Hoshino, Yoshikazu

    1986-01-01

    In nuclear power plants or general buildings, it is very important to form a fire-resistant seal around cables, cable trays and conduits passing through a wall or a floor. Rockwool, asbestos, glasswool and flame-retarded urethane foam have so far been used for these purposes. However, they were not satisfactory in sealing property, workability and safety. The silicone foam newly developed, ''TOSSEAL'' 300, has cleared these defects. It has now come to be used for fire resistant seal in nuclear power plants. (author)

  19. Infiltrating/sealing proximal caries lesions

    DEFF Research Database (Denmark)

    Martignon, S; Ekstrand, K R; Gomez, J

    2012-01-01

    This randomized split-mouth controlled clinical trial aimed at assessing the therapeutic effects of infiltration vs. sealing for controlling caries progression on proximal surfaces. Out of 90 adult students/patients assessed at university clinics and agreeing to participate, 39, each with 3...... differences in lesion progression between infiltration and placebo (P = 0.0012) and between sealing and placebo (P = 0.0269). The study showed that infiltration and sealing are significantly better than placebo treatment for controlling caries progression on proximal lesions. No significant difference...

  20. ATRF Ribbon-Cutting Ceremony Coincides with Chamber of Commerce Centennial Gala | Poster

    Science.gov (United States)

    By Frank Blanchard, Staff Writer U.S. Rep. Roscoe Bartlett, NCI Deputy Director for Management John Czajkowski, and SAIC Corporate Chief Executive Officer (CEO) John Jumper were joined by representatives of the Frederick County Chamber of Commerce in cutting the ribbon for the National Cancer Institute’s Advanced Technology Research Facility (ATRF).

  1. Cost saving synergistic shaft seal

    Science.gov (United States)

    Ludwig, L. P.; Strom, T. N.

    1976-01-01

    Segmented carbon rings, used to replace elastomeric seal lip, provide resistance to high temperatures generated in lubricating film. Machining and close manufacturing tolerances of conventional segmented seal are avoided by mounting segmented rings in elastomeric flex section.

  2. Development of a ceramic tamper indicating seal: SRNL contributions

    International Nuclear Information System (INIS)

    Krementz, Dan; Brinkman, Kyle S.; Martinez-Rodriguez, Michael J.; Mendez-Torres, Adrian E.; Weeks, George E.

    2013-01-01

    Savannah River National Laboratory (SRNL) and Sandia National Laboratories (SNL) are collaborating on development of a Ceramic Seal, also sometimes designated the Intrinsically Tamper Indicating Ceramic Seal (ITICS), which is a tamper indicating seal for international safeguards applications. The Ceramic Seal is designed to be a replacement for metal loop seals that are currently used by the IAEA and other safeguards organizations. The Ceramic Seal has numerous features that enhance the security of the seal, including a frangible ceramic body, protective and tamper indicating coatings, an intrinsic unique identifier using Laser Surface Authentication, electronics incorporated into the seal that provide cryptographic seal authentication, and user-friendly seal wire capture. A second generation prototype of the seal is currently under development whose seal body is of Low Temperature Co-fired Ceramic (LTCC) construction. SRNL has developed the mechanical design of the seal in an iterative process incorporating comments from the SNL vulnerability review team. SRNL is developing fluorescent tamper indicating coatings, with recent development focusing on optimizing the durability of the coatings and working with a vendor to develop a method to apply coatings on a 3-D surface. SRNL performed a study on the effects of radiation on the electronics of the seal and possible radiation shielding techniques to minimize the effects. SRNL is also investigating implementation of Laser Surface Authentication (LSA) as a means of unique identification of each seal and the effects of the surface coatings on the LSA signature.

  3. DEVELOPMENT OF A CERAMIC TAMPER INDICATING SEAL: SRNL CONTRIBUTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Krementz, D.; Brinkman, K.; Martinez-Rodriguez, M.; Mendez-Torres, A.; Weeks, G.

    2013-06-03

    Savannah River National Laboratory (SRNL) and Sandia National Laboratories (SNL) are collaborating on development of a Ceramic Seal, also sometimes designated the Intrinsically Tamper Indicating Ceramic Seal (ITICS), which is a tamper indicating seal for international safeguards applications. The Ceramic Seal is designed to be a replacement for metal loop seals that are currently used by the IAEA and other safeguards organizations. The Ceramic Seal has numerous features that enhance the security of the seal, including a frangible ceramic body, protective and tamper indicating coatings, an intrinsic unique identifier using Laser Surface Authentication, electronics incorporated into the seal that provide cryptographic seal authentication, and user-friendly seal wire capture. A second generation prototype of the seal is currently under development whose seal body is of Low Temperature Co-fired Ceramic (LTCC) construction. SRNL has developed the mechanical design of the seal in an iterative process incorporating comments from the SNL vulnerability review team. SRNL is developing fluorescent tamper indicating coatings, with recent development focusing on optimizing the durability of the coatings and working with a vendor to develop a method to apply coatings on a 3-D surface. SRNL performed a study on the effects of radiation on the electronics of the seal and possible radiation shielding techniques to minimize the effects. SRNL is also investigating implementation of Laser Surface Authentication (LSA) as a means of unique identification of each seal and the effects of the surface coatings on the LSA signature.

  4. 75 FR 66766 - NIAID Blue Ribbon Panel Meeting on Adjuvant Discovery and Development

    Science.gov (United States)

    2010-10-29

    ..., identifies gaps in knowledge and capabilities, and defines NIAID's goals for the continued discovery...), will convene a Blue Ribbon Panel to provide expertise in developing a strategic plan and research... vaccines. NIAID has developed a draft Strategic Plan and Research Agenda for Adjuvant Discovery and...

  5. Modeling the excitation of graphene plasmons in periodic grids of graphene ribbons: An analytical approach

    DEFF Research Database (Denmark)

    Gonçalves, P:A.D.; Dias, E. J. C.; Bludov, Yu V.

    2016-01-01

    We study electromagnetic scattering and subsequent plasmonic excitations in periodic grids of graphene ribbons. To address this problem, we develop an analytical method to describe the plasmon-assisted absorption of electromagnetic radiation by a periodic structure of graphene ribbons forming...... a diffraction grating for THz and mid-IR light. The major advantage of this method lies in its ability to accurately describe the excitation of graphene surface plasmons (GSPs) in one-dimensional (1D) graphene gratings without the use of both time-consuming, and computationally demanding full-wave numerical...... compare the theoretical data with spectra taken from experiments, for which we observe a very good agreement. These theoretical tools may therefore be applied to design new experiments and cutting-edge nanophotonic devices based on graphene plasmonics....

  6. Effects of material non-linearity on the residual stresses in a dendritic silicon crystal ribbon

    Science.gov (United States)

    Ray, Sujit K.; Utku, Senol

    1990-01-01

    Thermal stresses developed in a dendritic silicon crystal ribbon have been shown to cause plastic deformation and residual stresses in the ribbon. This paper presents an implementation of a numerical model proposed for thermoelastoplastic behavior of a material. The model has been used to study the effects of plasticity of silicon on the residual stresses. The material properties required to implement this model are all assumed, and the response of the material to the variations in these assumed parameters of the constitutive law and in the finite element mesh is investigated. The steady state growth process is observed to be periodic with nonzero residual stresses. Numerical difficulties are also encountered in the computer solution process, resulting in sharp jumps and large oscillations in the stress responses.

  7. Improved sealing for in-core systems

    International Nuclear Information System (INIS)

    Dunford, S.

    1989-01-01

    The in-core instrumentation sealing nozzles designed by Framatome have three mechanical seals in series instead of the one traditional seal, and are pressurized by simply tightening up the nozzle covers. They have been installed from the start on all Framatome PWRs, as well as having been backfitted on Belgium and Yugoslavian units and chosen for the Chinese Qinshan plant. (author)

  8. Multi-Canister overpack sealing configuration

    International Nuclear Information System (INIS)

    SMITH, K.E.

    1998-01-01

    The Spent Nuclear Fuel (SNF) position regarding the Multi-Canister Overpack (MCO) sealing configuration is to initially rely on an American Society of Mechanical Engineers (ASME) Section III Subsection NB code compliant mechanical closure/sealing system to quickly and safely establish and maintain full confinement of radioactive materials prior to and during MCO fuel drying activities. Previous studies have shown the mechanical seal to be the preferred closure method, based on dose, cost, and schedule considerations. The cost and schedule impacts of redesigning the mechanical closure to a welded shield plug do not support changing the closure system. The SNF Project has determined that the combined mechanical/welded closure system meets or exceeds the regulatory requirements to provide redundant seals while accommodating key safety and schedule limitations that are unique to K Basins fuel removal effort

  9. Coupled processes in repository sealing

    International Nuclear Information System (INIS)

    Case, J.B.; Kelsall, P.C.

    1985-01-01

    The significance of coupled processes in repository sealing is evaluated. In most repository designs, shaft seals will be located in areas of relatively low temperature perturbation, in which case the coupling of temperature with stress and permeability may be less significant than the coupling between stress and permeability that occurs during excavation. Constitutive relationships between stress and permeability are reviewed for crystalline rock and rocksalt. These provide a basis for predicting the development of disturbed zones near excavations. Field case histories of the degree of disturbance are presented for two contrasting rock types - Stripa granite and Southeastern New Mexico rocksalt. The results of field investigations in both rock types confirm that hydraulic conductivity or permeability is stress dependent, and that shaft seal performance may be related to the degree that stresses are perturbed and restored near the seal

  10. Sealing glasses for titanium and titanium alloys

    Science.gov (United States)

    Brow, Richard K.; McCollister, Howard L.; Phifer, Carol C.; Day, Delbert E.

    1997-01-01

    Barium lanthanoborate sealing-glass compositions are provided comprising various combinations (in terms of mole-%) of boron oxide (B.sub.2 O.sub.3), barium oxide (BaO), lanthanum oxide (La.sub.2 O.sub.3), and at least one other oxide selected from the group consisting of aluminum oxide (Al.sub.2 O.sub.3), calcium oxide (CaO), lithium oxide (Li.sub.2 O), sodium oxide (Na.sub.2 O), silicon dioxide (SiO.sub.2), or titanium dioxide (TiO.sub.2). These sealing-glass compositions are useful for forming hermetic glass-to-metal seals with titanium and titanium alloys having an improved aqueous durability and favorable sealing characteristics. Examples of the sealing-glass compositions are provided having coefficients of thermal expansion about that of titanium or titanium alloys, and with sealing temperatures less than about 900.degree. C., and generally about 700.degree.-800.degree. C. The barium lanthanoborate sealing-glass compositions are useful for components and devices requiring prolonged exposure to moisture or water, and for implanted biomedical devices (e.g. batteries, pacemakers, defibrillators, pumps).

  11. Development of Advanced Carbon Face Seals for Aircraft Engines

    Science.gov (United States)

    Falaleev, S. V.; Bondarchuk, P. V.; Tisarev, A. Yu

    2018-01-01

    Modern aircraft gas turbine engines require the development of seals which can operate for a long time with low leakages. The basic type of seals applied for gas turbine engine rotor supports is face seal. To meet the modern requirements of reliability, leak-tightness and weight, low-leakage gas-static and hydrodynamic seals have to be developed. Dry gas seals use both gas-static and hydrodynamic principles. In dry gas seals microgrooves are often used, which ensure the reverse injection of leakages in the sealed cavity. Authors have developed a calculation technique including the concept of coupled hydrodynamic, thermal and structural calculations. This technique allows to calculate the seal performance taking into account the forces of inertia, rupture of the lubricant layer and the real form of the gap. Authors have compared the efficiency of seals with different forms of microgrooves. Results of calculations show that seal with rectangular form of microgrooves has a little gap leading to both the contact of seal surfaces and the wear. Reversible microgrooves have a higher oil mass flow rate, whereas HST micro-grooves have good performance, but they are difficult to produce. Spiral microgrooves have both an acceptable leakages and a high stiffness of liquid layer that is important in terms of ensuring of sealing performance at vibration conditions. Therefore, the spiral grooves were chosen for the developed seal. Based on calculation results, geometric dimensions were chosen to ensure the reliability of the seal operation by creating a guaranteed liquid film, which eliminates the wear of the sealing surfaces. Seals designed were tested both at the test rig and in the engine.

  12. Reactor coolant pump seals: improving their performance

    International Nuclear Information System (INIS)

    Pothier, N.E.; Metcalfe, R.

    1986-06-01

    Large CANDU plants are benefitting from transient-resistant four-year reliable reactor coolant pump seal lifetimes, a direct result of AECL's 20-year comprehensive seal improvement program involving R and D staff, manufacturers, and plant designers and operators. An overview of this program is presented, which covers seal modification design, testing, post-service examination, specialized maintenance and quality control. The relevancy of this technology to Light Water Reactor Coolant Pump Seals is also discussed

  13. Development of simplified rotating plug seal structure

    International Nuclear Information System (INIS)

    Ueta, M.; Ichimiya, M.; Kanaoka, T.; Sekiya, H.; Ueda, S.; Ishibashi, S.

    1991-01-01

    We studied a compact and simplified rotating plug seal structure and conducted experiments for key elements of the concept such us the mechanical seal structure and sodium deposit prevention system. Good characteristics were confirmed for the mechanical seal structure, which utilizes an elastomer seal and thin lathe bearing. Applicability of the density barrier concept was also confirmed as the sodium deposit prevention system. This concept can be applied to actual plants. (author)

  14. Application study of magnetic fluid seal in hydraulic turbine

    International Nuclear Information System (INIS)

    Yu, Z Y; Zhang, W

    2012-01-01

    The waterpower resources of our country are abundant, and the hydroelectric power is developed, but at present the main shaft sealing device of hydraulic turbine is easy to wear and tear and the leakage is great. The magnetic fluid seal has the advantages of no contact, no wear, self-healing, long life and so on. In this paper, the magnetic fluid seal would be used in the main shaft of hydraulic turbine, the sealing structure was built the model, meshed the geometry, applied loads and solved by using MULTIPHYSICS in ANSYS software, the influence of the various sealing structural parameters such as tooth width, height, slot width, sealing gap on the sealing property were analyzed, the magnetic fluid sealing device suitable for large-diameter shaft and sealing water was designed, the sealing problem of the hydraulic turbine main shaft was solved effectively which will bring huge economic benefits.

  15. Sealing apparatus for airfoils of gas turbine engines

    Science.gov (United States)

    Jones, R.B.

    1998-05-19

    An improved airfoil tip sealing apparatus is disclosed wherein brush seals are attached to airfoil tips with the distal ends of the brush seal fibers sealingly contacting opposing wall surfaces. Embodiments for variable vanes, stators and both cooled and uncooled turbine blade applications are disclosed. 17 figs.

  16. Reactor coolant pump shaft seal stability during station blackout

    International Nuclear Information System (INIS)

    Rhodes, D.B.; Hill, R.C.; Wensel, R.G.

    1987-05-01

    Results are presented from an investigation into the behavior of Reactor Coolant Pump shaft seals during a potential station blackout (loss of all ac power) at a nuclear power plant. The investigation assumes loss of cooling to the seals and focuses on the effect of high temperature on polymer seals located in the shaft seal assemblies, and the identification of parameters having the most influence on overall hydraulic seal performance. Predicted seal failure thresholds are presented for a range of station blackout conditions and shaft seal geometries

  17. Reactor coolant pump shaft seal stability during station blackout

    Energy Technology Data Exchange (ETDEWEB)

    Rhodes, D B; Hill, R C; Wensel, R G

    1987-05-01

    Results are presented from an investigation into the behavior of Reactor Coolant Pump shaft seals during a potential station blackout (loss of all ac power) at a nuclear power plant. The investigation assumes loss of cooling to the seals and focuses on the effect of high temperature on polymer seals located in the shaft seal assemblies, and the identification of parameters having the most influence on overall hydraulic seal performance. Predicted seal failure thresholds are presented for a range of station blackout conditions and shaft seal geometries.

  18. Growth behaviour of twisted ribbons of barium carbonate/silica self-assembled ceramics

    International Nuclear Information System (INIS)

    Garcia-Ruiz, J.M.; Moreno, A.

    1997-01-01

    Twisted ribbons of self-assembled crystal aggregates of barium carbonate, in the presence of silicate ions at pH 9.5 grow at constant rate between 20 and 50 mu m/min. The morphological behaviour depends on temperature, while it was demonstrated to be independent of the viscosity of the growth environment. (Author) 7 refs

  19. Trace element analysis in the serum and hair of Antarctic leopard seal, Hydrurga leptonyx, and Weddell seal, Leptonychotes weddellii

    Energy Technology Data Exchange (ETDEWEB)

    Gray, Rachael [Faculty of Veterinary Science, University of Sydney, NSW 2006 Australia (Australia); Australian Marine Mammal Research Centre PO Box 20 Mosman, NSW 2088 (Australia)], E-mail: rgray@vetsci.usyd.edu.au; Canfield, Paul [Faculty of Veterinary Science, University of Sydney, NSW 2006 (Australia); Rogers, Tracey [Australian Marine Mammal Research Centre PO Box 20 Mosman, NSW 2088 (Australia); Evolution and Ecology Research Centre and School of Biological Earth and Environmental Sciences, University of New South Wales, NSW 2052 (Australia)

    2008-07-25

    Leopard seal, Hydrurga leptonyx, and Weddell seal, Leptonychotes weddellii, occupy an upper trophic level within the Antarctic ecosystem and are useful indicator species in the Southern Ocean of trace element concentrations. Reference values for the concentration of 19 trace elements were determined in the serum and hair of leopard and Weddell seals sampled in Eastern Antarctica. These reference values can be used as 'baseline' levels for monitoring trace element concentrations in these species. Greater trace element concentrations were determined in hair compared to serum, indicating different time scales of trace element accumulation in these samples. For the majority of trace elements, except for Se in the leopard seal samples and Cr in the Weddell seal samples, significant regression relationships for trace element concentrations in hair and serum were not elucidated. Significant differences were determined in the concentrations of seven out of 15 elements with hair type, moult and new, in the leopard seal; concentrations in moult hair were determined to be greater than in new hair for all elements except Zn. Hair analysis was determined to be useful for monitoring exposure to trace elements and when collected off the ice from moulting seals, hair can be employed as a non-invasive sample for trace element analysis in leopard and Weddell seals.

  20. Solid oxide fuel cell having a glass composite seal

    Science.gov (United States)

    De Rose, Anthony J.; Mukerjee, Subhasish; Haltiner, Jr., Karl Jacob

    2013-04-16

    A solid oxide fuel cell stack having a plurality of cassettes and a glass composite seal disposed between the sealing surfaces of adjacent cassettes, thereby joining the cassettes and providing a hermetic seal therebetween. The glass composite seal includes an alkaline earth aluminosilicate (AEAS) glass disposed about a viscous glass such that the AEAS glass retains the viscous glass in a predetermined position between the first and second sealing surfaces. The AEAS glass provides geometric stability to the glass composite seal to maintain the proper distance between the adjacent cassettes while the viscous glass provides for a compliant and self-healing seal. The glass composite seal may include fibers, powders, and/or beads of zirconium oxide, aluminum oxide, yttria-stabilized zirconia (YSZ), or mixtures thereof, to enhance the desirable properties of the glass composite seal.

  1. Piston rod seal for a Stirling engine

    Science.gov (United States)

    Shapiro, Wilbur

    1984-01-01

    In a piston rod seal for a Stirling engine, a hydrostatic bearing and differential pressure regulating valve are utilized to provide for a low pressure differential across a rubbing seal between the hydrogen and oil so as to reduce wear on the seal.

  2. Folded membrane dialyzer with mechanically sealed edges

    Energy Technology Data Exchange (ETDEWEB)

    Markley, F.W.

    A semipermeable membrane is folded in accordion fashion to form a stack of pleats and the edges are sealed so as to isolate the opposite surfaces of the membrane. The stack is contained within a case that provides ports for flow of blood in contact with one surface of the membrane through channels formed by the pleats and also provides ports for flow of a dialysate through channels formed by the pleats in contact with the other surface of the membrane. The serpentine side edges of the membrane are sealed by a solidified plastic material, whereas effective mechanical means are provided to seal the end edges of the folded membrane. The mechanical means include a clamping strip which biases case sealing flanges into a sealed relationship with end portions of the membrane near the end edges, which portions extend from the stack and between the sealing flanges.

  3. 30 CFR 75.337 - Construction and repair of seals.

    Science.gov (United States)

    2010-07-01

    ... sealed areas. (b) Prior to sealing, the mine operator shall— (1) Remove insulated cables, batteries, and other potential electric ignition sources from the area to be sealed when constructing seals, unless it... after April 18, 2008, the seal at the lowest elevation shall have a corrosion-resistant, non-metallic...

  4. Liquid-metal dip seal with pneumatic spring

    International Nuclear Information System (INIS)

    Poindexter, A.M.

    1977-01-01

    An improved liquid-metal dip seal for sealing the annulus between rotating plugs in the reactor vessel head of a liquid-metal fast-breeder nuclear reactor has two legs of differing widths communicating under a seal blade; the wide leg is also in communication with cover gas of the reactor and the narrow leg is also in communication with an isolated plug annulus above the seal. The annulus contains inert gas which acts as a pneumatic spring. Upon increasing cover gas pressure which depresses the level in the wide leg and greatly increases the level in the narrow leg, the pneumatic spring is compressed, and resists further level changes, thus preventing radioactive cover gas from bubbling through the seal

  5. Experimental toxoplasma gondii infection in grey seals (Halichoerus grypus)

    DEFF Research Database (Denmark)

    Gajadhar, A. A.; Measures, L.; Forbes, L. B.

    2004-01-01

    Laboratory-reared animals were used to assess the susceptibility of seals (Halichoerus grypus) to Toxoplasma gondii infection. Four seals were each orally inoculated with 100 or 10,000 oocysts of T. gondii (VEG strain), and another 4 seals served as negative controls. Occasionally, mild behavioral...... changes were observed in all inoculated seals but not in control animals. A modified agglutination test revealed the presence of antibodies to T. gondii in sera collected from inoculated seals and mice inoculated as controls. No evidence of the parasite was found on an extensive histological examination...... of seal tissues, and immunohistochemical staining of tissue sections from inoculated seals revealed a single tissue cyst in only 1 seal. Control mice inoculated with 10 oocysts from the same inoculum given to seals became serologically and histologically positive for T. gondii. Cats that were fed brain...

  6. Low torque hydrodynamic lip geometry for rotary seals

    Science.gov (United States)

    Dietle, Lannie L.; Schroeder, John E.

    2015-07-21

    A hydrodynamically lubricating geometry for the generally circular dynamic sealing lip of rotary seals that are employed to partition a lubricant from an environment. The dynamic sealing lip is provided for establishing compressed sealing engagement with a relatively rotatable surface, and for wedging a film of lubricating fluid into the interface between the dynamic sealing lip and the relatively rotatable surface in response to relative rotation that may occur in the clockwise or the counter-clockwise direction. A wave form incorporating an elongated dimple provides the gradual convergence, efficient impingement angle, and gradual interfacial contact pressure rise that are conducive to efficient hydrodynamic wedging. Skewed elevated contact pressure zones produced by compression edge effects provide for controlled lubricant movement within the dynamic sealing interface between the seal and the relatively rotatable surface, producing enhanced lubrication and low running torque.

  7. Turbine and Structural Seals Team Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — Seals Team Facilities conceive, develop, and test advanced turbine seal concepts to increase efficiency and durability of turbine engines. Current projects include...

  8. Tamper-indicating devices and safeguards seals evaluation test report

    International Nuclear Information System (INIS)

    Horton, P.R.V.; Waddoups, I.G.

    1993-12-01

    Sandia National Laboratories was asked to evaluate the seals used as tamper-indicating devices (TIDs) at DOE facilities. Initially, a survey determined what seal manufacturers were being used and what similar seal types were available. Once the required specifications for TIDs were defined, a test plan measured the currently available seals against the requirements. Environmental and physical type tests stressed the seals under two broad categories: (1) handling durability and (2) tamper resistance. Results of the testing provide comparative ratings for the various seals, recommendations for using currently available seals, and a new tamper-indicating technology

  9. Design and research of seal structure for thermocouple column assembly

    International Nuclear Information System (INIS)

    Rao Qiqi; Li Na; Zhao Wei; Ma Zhigang

    2015-01-01

    The new seal structure was designed to satisfy the function of thermocouple column assembly and the reactor structure. This seal structure uses the packing graphite ring and adopts the self-sealing principle. Cone angle is brought to the seal face of seal structure which is conveniently to assembly and disassembly. After the sealing principle analysis and stress calculation of graphite ring which adopt the cone angle, the cone angle increases the radial force of seal structure and improves the seal effect. The stress analysis result shows the seal structure strength satisfies the regulation requirement. The cold and hot function test results shows the sealing effect is good, and the design requirement is satisfied. (authors)

  10. Development of sealing plug for sweep gas line

    International Nuclear Information System (INIS)

    Kikuchi, Taiji; Yamada, Hirokazu; Saitoh, Takashi; Nakamichi, Masaru; Tsuchiya, Kunihiko; Kawamura, Hiroshi

    2004-03-01

    On the irradiation capsule for neutron irradiation test of the tritium breeder, the sealing plug is necessary to prevent a leak of tritium gas when the tritium breeder is picked up from the irradiation capsule after irradiation test. However, the general valve and plug cannot apply to sealing of the sweep gas line because of the following factors, the neutron irradiation effect, limited space in the irradiation capsule, high sealing efficiency, simple method and operation for control. Therefore, the sealing plug for sweep gas line has to be developed. This paper reports the development of the sealing plug for sweep gas line and the operating procedure of the sealing plug in the irradiation capsule. (author)

  11. 2007 NASA Seal/Secondary Air System Workshop. Volume 1

    Science.gov (United States)

    Steinetz, Bruce M.; Hendricks, Robert C.; Delgado, Irebert

    2008-01-01

    The 2007 NASA Seal/Secondary Air System workshop covered the following topics: (i) Overview of NASA's new Orion project aimed at developing a new spacecraft that will fare astronauts to the International Space Station, the Moon, Mars, and beyond; (ii) Overview of NASA's fundamental aeronautics technology project; (iii) Overview of NASA Glenn s seal project aimed at developing advanced seals for NASA's turbomachinery, space, and reentry vehicle needs; (iv) Reviews of NASA prime contractor, vendor, and university advanced sealing concepts, test results, experimental facilities, and numerical predictions; and (v) Reviews of material development programs relevant to advanced seals development. Turbine engine studies have shown that reducing seal leakage as well as high-pressure turbine (HPT) blade tip clearances will reduce fuel burn, lower emissions, retain exhaust gas temperature margin, and increase range. Turbine seal development topics covered include a method for fast-acting HPT blade tip clearance control, noncontacting low-leakage seals, intershaft seals, and a review of engine seal performance requirements for current and future Army engine platforms.

  12. Comparison of correlation algorithms for identifying ultrasonic seals

    International Nuclear Information System (INIS)

    Beer, C.L.; McKenzie, J.M.

    1991-01-01

    Ultrasonic seals are used on reactor fuel assemblies for international safeguards applications. The seals are read by a Seal Pattern Reader to obtain a discrete digital signature that is unique to each seal. The signature is used to determine the identity and integrity of the seals such that accountability and integrity of the nuclear fuel assemblies can be addressed. A correlation coefficient is calculated between the signature obtained at the time of inspection and a stored reference signature, yielding a number between negative one and one. Numbers close to one indicate a high probability that the two signatures represent the same seal. Data from two seals were studied, the Atomic Energy of Canada Limited Random Coil (ARC) seal and the JRC-Ispra VAK-III seal. Currently, correlation coefficients are obtained using data in the time or spatial domain, respectively. An approach is proposed in which the correlation coefficients are obtained from the Fourier transforms of the data. This paper reports that the objective of the study was to perform independent experiments on available ARC and VAK-III data to determine the advantages, if any, of transforming the data to the frequency spectrum prior to performing the correlation calculation. The results indicate definite advantages can be obtained

  13. Effect of sealing on the morphology of anodized aluminum oxide

    International Nuclear Information System (INIS)

    Hu, Naiping; Dong, Xuecheng; He, Xueying; Browning, James F.; Schaefer, Dale W.

    2015-01-01

    Highlights: • We explored structural change of anodizing aluminum oxide induced by sealing. • All sealing methods decrease pore size as shown by X-ray/neutron scattering. • Cold sealing and hot water sealing do not alter the aluminum oxide framework. • Hot nickel acetate sealing both fills the pores and deposits on air oxide interface. • Samples with hot nickel acetate sealing outperform other sealing methods. - Abstract: Ultra-small angle X-ray scattering (USAXS), small-angle neutron scattering (SANS), X-ray reflectometry (XRR) and neutron reflectometry (NR) were used to probe structure evolution induced by sealing of anodized aluminum. While cold nickel acetate sealing and hot-water sealing decrease pore size, these methods do not alter the cylindrical porous framework of the anodic aluminum oxide layer. Hot nickel acetate both fills the pores and deposits on the air surface (air–oxide interface), leading to low porosity and small mean pore radius (39 Å). Electrochemical impedance spectroscopy and direct current polarization show that samples sealed by hot nickel acetate outperform samples sealed by other sealing methods

  14. Ergonomics and safety of manual bag sealing.

    NARCIS (Netherlands)

    Groot, M.D. de; Bosch, T.; Eikhout, S.M.; Vink, P.

    2005-01-01

    A variety of seals is used to close bags. Each seal has advantages and disadvantages. For shop assistants sealing bags could be a repetitive physically demanding action. Opening and closing the bags again can cause some discomfort or annoyance for consumers. Besides, it is an activity which can

  15. Improved magnetoimpedance and mechanical properties on nanocrystallization of amorphous Fe{sub 68.5}Si{sub 18.5}Cu{sub 1}Nb{sub 3}B{sub 9} ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, Trilochan [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Proof and Experimental Establishment, Balasore 756025 (India); Majumdar, B. [Defence Metallurgical Research Laboratory, Hyderabad 500068 (India); Srinivas, V., E-mail: veeturi@iitm.ac.in [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India); Srinivas, M. [Defence Metallurgical Research Laboratory, Hyderabad 500068 (India); Nath, T.K. [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Agarwal, G. [Department of Metallurgical Engineering, Banaras Hindu University, Varanasi 221005 (India)

    2013-10-15

    The effect of heat-treatment temperature on evolution of microstructures, mechanical and soft magnetic properties and magnetoimpedance (MI) effect in rapidly solidified Fe{sub 68.5}Si{sub 18.5}Cu{sub 1}Nb{sub 3}B{sub 9} ribbons, has been investigated. The as-quenched ribbons were subjected to heat-treatment at different temperatures between 400 and 600 °C for 1 h under high vacuum. Detailed structural studies on the ribbons heat-treated at and above 525 °C revealed the presence of nanocrystalline Fe{sub 3}Si phases embedded in a residual amorphous matrix. The ribbon heat-treated at 550 °C temperature exhibits maximum ductility, maximum relative permeability of 4.8×10{sup 4}, minimum coercivity of 0.1 Oe, and maximum MI value of 62%. The enhanced MI effect is believed to be related to the magnetic softening of 550 °C heat-treated ribbons. However, the magnetic properties and MI effect deteriorated in the samples heat-treated above 550 °C due to the coarsening of grain sizes. The soft magnetic behavior of the nanocrystalline ribbons are discussed in the light of random anisotropy model, whereas the MI effect is discussed through standard skin effect in electrodynamics. - Highlights: • Microstructure was tuned by controlled crystallization to obtain superior magnetic properties. • Improved MI in the heat-treated ribbons is attributed to the superior electromagnetic properties. • Correlation between MI and magnetic properties of nc-Fe{sub 68.5}Si{sub 18.5}Cu{sub 1}Nb{sub 3}B{sub 9} is established. • All the observed features are consistent with the proposed random anisotropy model.

  16. Cannula has lip seal movingly coupled to proximal section, to facilitate relative movement of instrument shaft between seal and proximal section and to maintain sealing engagement between shaft and proximal portion

    OpenAIRE

    Bonadio, Frank; Vaugh, Trevor

    2007-01-01

    The cannula (1) has an instrument insertion section (3) and a tube (2) with an access channel (7) for extension of an instrument. A lip seal (4) movingly couples to a proximal section to engage with an instrument shaft (5). The seal facilitates a lateral movement of the instrument, and maintains the sealing engagement between the seal and the instrument shaft. A coupling portion made of gelatinous elastomeric material with plasticizer consisting of naturally derived oils, synthetic oils and l...

  17. Dampers for Stationary Labyrinth Seals

    Science.gov (United States)

    El-Aini, Yehia; Mitchell, William; Roberts, Lawrence; Montgomery, Stuart; Davis, Gary

    2011-01-01

    Vibration dampers have been invented that are incorporated as components within the stationary labyrinth seal assembly. These dampers are intended to supplement other vibration-suppressing features of labyrinth seals in order to reduce the incidence of high-cycle-fatigue failures, which have been known to occur in the severe vibratory environments of jet engines and turbopumps in which labyrinth seals are typically used. A vibration damper of this type includes several leaf springs and/or a number of metallic particles (shot) all held in an annular seal cavity by a retaining ring. The leaf springs are made of a spring steel alloy chosen, in conjunction with design parameters, to maintain sufficient preload to ensure effectiveness of damping at desired operating temperatures. The cavity is vented via a small radial gap between the retaining ring and seal housing. The damping mechanism is complex. In the case of leaf springs, the mechanism is mainly friction in the slippage between the seal housing and individual dampers. In the case of a damper that contains shot, the damping mechanism includes contributions from friction between individual particles, friction between particles and cavity walls, and dissipation of kinetic energy of impact. The basic concept of particle/shot vibration dampers has been published previously; what is new here is the use of such dampers to suppress traveling-wave vibrations in labyrinth seals. Damping effectiveness depends on many parameters, including, but not limited to, coefficient of friction, mode shape, and frequency and amplitude of vibrational modes. In tests, preloads of the order of 6 to 15 lb (2.72 to 6.8 kilograms) per spring damper were demonstrated to provide adequate damping levels. Effectiveness of shot damping of vibrations having amplitudes from 20 to 200 times normal terrestrial gravitational acceleration (196 to 1,960 meters per square second) and frequencies up to 12 kHz was demonstrated for shot sizes from 0.032 to

  18. A Ribbon-like Structure in the Ejective Organelle of the Green Microalga Pyramimonas parkeae (Prasinophyceae) Consists of Core Histones and Polymers Containing N-acetyl-glucosamine.

    Science.gov (United States)

    Yamagishi, Takahiro; Kurihara, Akira; Kawai, Hiroshi

    2015-11-01

    The green microalga, Pyramimonas parkeae (Prasinophyceae) has an ejective organelle containing a coiled ribbon structure resembling the ejectisome in Cryptophyta. This structure is discharged from the cell by a stimulus and extends to form a tube-like structure, but the molecular components of the structure have not been identified. Tricine-SDS-PAGE analysis indicated that the ribbon-like structure of P. parkeae contains some proteins and low molecular acidic polymers. Edman degradation, LC/MS/MS analyses and immunological studies demonstrated that their proteins are core histones (H3, H2A, H2B and H4). In addition, monosaccharide composition analysis of the ribbon-like structures and degradation by lysozyme strongly indicated that the ribbon-like structure consist of β (1-4) linked polymers containing N-acetyl-glucosamine. Purified polymers and recombinant histones formed glob-like or filamentous structures. Therefore we conclude that the ribbon-like structure of P. parkeae mainly consists of a complex of core histones (H3, H2A, H2B and H4) and polymers containing N-acetyl-glucosamine, and suggest to name the ejective organelle in P. parkeae the "histrosome" to distinguish it from the ejectisome in Cryptophyta. Copyright © 2015 Elsevier GmbH. All rights reserved.

  19. Laser assisted crystallization of ferromagnetic amorphous ribbons: A multimodal characterization and thermal model study

    Energy Technology Data Exchange (ETDEWEB)

    Katakam, Shravana; Santhanakrishnan, S.; Smith, Casey; Banerjee, Rajarshi; Dahotre, Narendra B. [Laboratory of Laser Materials Processing and Synthesis Department of Materials Science and Engineering University of North Texas, Denton, Texas 76207 (United States); Devaraj, Arun; Bowden, Mark; Thevuthasan, Suntharampillai [William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States); Ramanujan, R. V. [Schhol of Materials Science and Engineering Nanyang Technological University, Singapore 639798 (Singapore)

    2013-11-14

    This paper focuses on laser-based de-vitrification of amorphous soft magnetic Fe-Si-B ribbons and its consequent influence on the magnetic properties. Laser processing resulted in a finer scale of crystallites due to rapid heating and cooling during laser annealing compared to conventional furnace annealing process. A significant increase in saturation magnetization is observed for laser-annealed ribbons compared to both as-received and furnace annealed samples coupled with an increase in coercivity compared to the as received samples. The combined effect of thermal histories and stresses developed during laser annealing results in the formation of nano-crystalline phase along the laser track. The phase evolution is studied by micro-XRD and TEM analysis. Solute partitioning and compositional variation within the phases are obtained by Local Electrode Atom probe analysis. The evolution of microstructure is rationalized using a Finite Element based heat transfer multi-physics model.

  20. Ductile alloys for sealing modular component interfaces

    Science.gov (United States)

    Marra, John J.; Wessell, Brian J.; James, Allister W.; Marsh, Jan H.; Gear, Paul J.

    2017-08-08

    A vane assembly (10) having: an airfoil (12) and a shroud (14) held together without metallurgical bonding there between; a channel (22) disposed circumferentially about the airfoil (12), between the airfoil (12) and the shroud (14); and a seal (20) disposed in the channel (22), wherein during operation of a turbine engine having the vane assembly (10) the seal (20) has a sufficient ductility such that a force generated on the seal (20) resulting from relative movement of the airfoil (12) and the shroud (14) is sufficient to plastically deform the seal (20).

  1. Ceramic-glass-metal seal by microwave heating

    Science.gov (United States)

    Meek, Thomas T.; Blake, Rodger D.

    1985-01-01

    A method for producing a ceramic-glass-metal seal by microwaving mixes a slurry of glass sealing material and coupling agent and applies same to ceramic and metal workpieces. The slurry and workpieces are then insulated and microwaved at a power, time and frequency sufficient to cause a liquid phase reaction in the slurry. The reaction of the glass sealing material forms a chemically different seal than that which would be formed by conventional heating because it is formed by diffusion rather than by wetting of the reactants.

  2. Bingham Sealing and Application in Vacuum Clamping

    Science.gov (United States)

    Yao, S. M.; Teo, Wee Kin; Geng, Zunmin; Turner, Sam; Ridgway, Keith

    2011-12-01

    Vacuum clamping is extensively used in shell machining. In this paper a Bingham Sealing (BS) is presented and formulized based on Bingham plastic performance. The sealing capability of BS is evaluated in various cases. A new Bingham plastic is developed and the yield stress is measured. The performances of "O"ring sealing and BS with the developed Bingham plastic are compared to the static experiment. In this experiment the same vacuum is achieved and the distortion of the blade with BS is better than that with "O" ring sealing.

  3. Bingham Sealing and Application in Vacuum Clamping

    International Nuclear Information System (INIS)

    Yao, S M; Teo, Wee Kin; Geng Zunmin; Turner, Sam; Ridgway, Keith

    2011-01-01

    Vacuum clamping is extensively used in shell machining. In this paper a Bingham Sealing (BS) is presented and formulized based on Bingham plastic performance. The sealing capability of BS is evaluated in various cases. A new Bingham plastic is developed and the yield stress is measured. The performances of Or ing sealing and BS with the developed Bingham plastic are compared to the static experiment. In this experiment the same vacuum is achieved and the distortion of the blade with BS is better than that with 'O' ring sealing.

  4. Tunnel sealing: concept and feasibility evidence

    International Nuclear Information System (INIS)

    Brenner, R.P.; Eppinger, G.; Mettler, K.

    1991-01-01

    This report discusses first the aim and purpose of tunnel seals as well as the requirements which should be satisfied. The basic seal concept is a zoned plug consisting of key zones and intermediate zones. The key zones act as barrier elements and will be placed into sections of competent and sound rock. The main function of the intermediate zones is that of a support and the requirements for sealing efficiency may be somewhat relaxed. Three sealing concepts have been devised for both the key zones and the intermediate zones. They differ in the materials used for the seal and in the placement method. For the key zones highly compacted bentonite is recommended, but also cement-based materials, such as standard concrete or prepact concrete are considered suitable. For the intermediate zones, the use of pumped concrete with subsequent grouting of the roof zone is favourable, but also a combination of concrete with a sand/gravel mixture or with properly compacted excavation material is feasible. The concepts introduced can all be realized by conventional tunnelling methods. Excavation by tunnel boring machine is most advantageous as it minimizes disturbance of the rock caused by the cavity-forming process. By employing simple material models, it can be shown that the depth of the excavation disturbed zone can be minimized if support of the tunnel is provided as early as possible after excavation. The cutting of a groove in the tunnel wall along the key zone can further contribute to reduce the depth of the excavation-disturbed zone. In order to ensure the quality of a seal, the quantities of the materials used can be checked and the work procedures to place the seal can be supervised. For the latter the experiences obtained from a large-scale test should be available. Finally, it is also shown that when considering safety analytical aspects, the proposed sealing concepts represent adequate solutions in spite of the probably increased permeability in the excavation

  5. HMSRP Hawaiian Monk Seal Crittercam video

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project investigates foraging behavior of Hawaiian monk seals by conducting telemetry studies. During these studies, live seals are instrumented with dive...

  6. Thermal, magnetic, and structural properties of soft magnetic FeCrNbCuSiB alloy ribbons

    International Nuclear Information System (INIS)

    Rosales-Rivera, A.; Valencia, V.H.; Quintero, D.L.; Pineda-Gomez, P.; Gomez, M.

    2006-01-01

    The thermal, magnetic and structural properties of amorphous magnetic Fe 73.5-x Cr x Nb 3 Cu 1 Si 13.5 B 9 alloy ribbons, with x=0, 2, 4, 6, 8, and 10, were studied by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), magneto-impedance measurements and X-ray diffraction (XRD). The ribbons exhibit ultrasoft magnetic behavior, especially giant magneto-impedance effect, GMI. A three-peak behavior was observed in GMI curves. Particular attention has been given to observation of crystallization kinetics via DSC and TGA. The primary crystallization T pcr , and Curie T c , temperatures were determined from DSC and TGA data, respectively. The effect of partial substitution of iron by Cr on the thermal and magnetic properties is discussed

  7. Leak detection of KNI seals

    International Nuclear Information System (INIS)

    Baranyai, G.; Peter, A.; Windberg, P.

    1990-03-01

    In Unit 3 and 4 of the Paks Nuclear Power Plant, Hungary, KNI type seals are used as lead-throughs with conical nickel sealing rings. Their failure can be critical for the operation of the reactor. An Acoustical Leak Detection System (ALDS) was constructed and tested for the operational testing of the seals. Some individual papers are presented in this collection on the calibration and testing of the ALDS intended to be placed on the top of the reactor vessels. The papers include simulation measurements of Unit 3 of NPP, laboratory experiments, evaluation of measurements, and further development needs with the ALDS. (R.P.) 50 figs.; 19 tabs

  8. Unification of reactor elastomeric sealing based on material

    International Nuclear Information System (INIS)

    Sinha, N.K.; Raj, Baldev

    2012-01-01

    The unification of elastomeric sealing applications of Indian nuclear reactors based on a few qualified fluoroelastomer/perfluoroelastomer compounds and standardized approaches for finite element analysis (FEA) based design, manufacturing process and antifriction coatings is discussed. It is shown that the advance polymer architecture based Viton ® formulation developed for inflatable seals of 500 MWe Prototype Fast Breeder Reactor (PFBR) and its four basic variations can encompass other sealing applications of PFBR with minimum additional efforts on development and validation. Changing the blend ratio of Viton ® GBL 200S and 600S in inflatable seal formulation could extend its use to Pressurized Heavy Water Reactors (PHWRs). The higher operating temperature of Advanced Heavy Water Reactor (AHWR) seals expands the choice to perfluoroelastomers. FEA based on plane-strain/axisymmetric modeling (with Mooney–Rivlin as the basic constitutive model), seal manufacture by cold feed extrusion and injection molding as well as plasma Teflon-like coating belonging to two variations obtained from the development of inflatable seals provide the necessary standardization for unification. The gains in simplification of design, development and operation of seals along with the enhancements of safety and reliability are expected to be substantial.

  9. Surface and bulk magnetic properties of as-quenched FeNbB ribbons

    Czech Academy of Sciences Publication Activity Database

    Životský, O.; Postava, K.; Kraus, Luděk; Juraszek, J.; Jirásková, Yvonna; Teillet, J.; Barčová, K.; Švec, P.; Janičkovič, D.; Pištora, J.

    2008-01-01

    Roč. 320, č. 8 (2008), s. 1535-1540 ISSN 0304-8853 R&D Projects: GA ČR GA202/05/2111; GA AV ČR KAN400100653 Institutional research plan: CEZ:AV0Z20410507; CEZ:AV0Z10100520 Keywords : Surface nanocrystallization * Fe-based ribbon * depth profile Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.283, year: 2008

  10. Machine Vision Inspection of Polymeric Traypack Seal Areas

    National Research Council Canada - National Science Library

    Coburn, John

    2002-01-01

    .... Since entrapped matter can lead to open seals, defects, and seal anomalies, a method of measurement for seal area contamination is useful in quantifying effects of filler changes, line speeds, and product formulations...

  11. 75 FR 11908 - Narrow Woven Ribbons With Woven Selvedge From China and Taiwan

    Science.gov (United States)

    2010-03-12

    ...)] Narrow Woven Ribbons With Woven Selvedge From China and Taiwan AGENCY: United States International Trade...(b) of the Act (19 U.S.C. 1673d(b)) to determine whether an industry in the United States is materially injured or threatened with material injury, or the establishment of an industry in the United...

  12. Reactor coolant pump shaft seal behavior during station blackout

    International Nuclear Information System (INIS)

    Kittmer, C.A.; Wensel, R.G.; Rhodes, D.B.; Metcalfe, R.; Cotnam, B.M.; Gentili, H.; Mings, W.J.

    1985-04-01

    A testing program designed to provide fundamental information pertaining to the behavior of reactor coolant pump (RCP) shaft seals during a postulated nuclear power plant station blackout has been completed. One seal assembly, utilizing both hydrodynamic and hydrostatic types of seals, was modeled and tested. Extrusion tests were conducted to determine if seal materials could withstand predicted temperatures and pressures. A taper-face seal model was tested for seal stability under conditions when leaking water flashes to steam across the seal face. Test information was then used as the basis for a station blackout analysis. Test results indicate a potential problem with an elastomer material used for O-rings by a pump vendor; that vendor is considering a change in material specification. Test results also indicate a need for further research on the generic issue of RCP seal integrity and its possible consideration for designation as an unresolved safety issue

  13. Cask systems development program seal technology

    International Nuclear Information System (INIS)

    Madsen, M.M.; Humphreys, D.L.; Edwards, K.R.

    1991-01-01

    General design or test performance requirements for radioactive materials (RAM) packages are specified in Title 10 of the US Code of Federal Regulations Part 71 (10 CFR 71). Seals that provide the containment system interface between the packaging body and the closure must function in both high- and low-temperature environments under dynamic and static conditions. Experiments were performed to characterize the performance of several seal materials at low temperatures. Helium leak tests on face seals were used to compare the materials. Materials tested include butyl, neoprene, ethylene propylene, fluorosilicone, silicone, Eypel, Kalrez, Teflon, fluorocarbon, and Teflon/silicone composites. Results show that the seal materials tested, with the exception of silicone S613-60, are not leak tight (1 x 10 -7 std cm 3 /s) at manufacturer low-temperature ratings

  14. High pressure thimble/guide tube seal fitting with built-in low pressure seal especially suitable for facilitated and more efficient nuclear reactor refueling service

    International Nuclear Information System (INIS)

    Bhatt, P.N.; Blaushield, R.M.

    1991-01-01

    This patent describes a HP/LP seal arrangement for an elongated guide tube and an elongated thimble disposed therein. The guide tube and thimble extending outwardly from the core of a nuclear reactor to a seal table where the guide tube is welded to the seal table to provide a high pressure seal relative thereto. It comprises: a tubular seal fitting disposed in alignment with the guide tube with the thimble extending therethrough on the low pressure side of the seal table; first high pressure sealing means coupling one end of the fitting to an end of the guide tube to prevent leakage from within the guide tube; inwardly facing thread means disposed adjacent the other and outer end of the seal fitting; a nut having an opening through which the thimble extends and further having outwardly facing threading in mating engagement with the fitting thread means; the fitting having a seal seat spaced longitudinally inwardly from the thread means and facing the fitting outer end and further disposed annularly about the inner surface of the fitting; deformable ring seal means; second releasable high pressure sealing means coupling the thimble to the outer end portion of the guide tube

  15. Seal for an object containing nuclear fuel

    International Nuclear Information System (INIS)

    Scheuerpflug, W.; Nentwich, D.

    1977-01-01

    This seal which cannot be counterfeited, specially for sealing nuclear objects, e.g. fuel rods, not only makes any damage which has taken place obvious, but makes identification according to a key possible. For this purpose a minimum number of 'particles' or small bodies, which are identical but of different permeability, are fixed inside a short tube during 'loading' of the seal in a certain or an accidental sequence. The sequence of the spheres, which represents a key, can only be determined by special electromagnetic measuring equipment. On first opening the seal, this key sequence is irrevocably destroyed. (HP) [de

  16. Properties of Sealing Materials in Groundwater Wells

    DEFF Research Database (Denmark)

    Köser, Claus

    pellets as sealing material in groundwater wells. The way and the pattern, in which bentonite pellets are deposited, have been shown to have an effect on the swelling pressure of the bentonite seal. During the transport phase of pellets from the terrain to a given sedimentation depth, a sorting process......) into densities for clay/water systems has been developed. This method has successfully been used to evaluate e.g., macroporosity, homogenization of the bentonite seal during the hydration of water, hydraulic conductivity and the creation of channels in the bentonite seals. Based on the results obtained...

  17. Sealing of ceramic SOFC-components with glass seals; Fuegen von keramischen Komponenten der Hochtemperatur-Brennstoffzellen mittels Glas- und Glaskeramikloten

    Energy Technology Data Exchange (ETDEWEB)

    Schillig, Cora

    2012-07-10

    The solid oxide fuel cell (SOFC) converts chemical energy of a fuel directly into electrical energy. However, for the implementation of SOFC-technology in competition to conventional power plants costs have to be reduced. The use of an alternative tubular cell design without closed end would allow reducing costs during cell manufacturing. However, this change in design makes a gastight sealing inside the generator near the gas inlet necessary. Different ceramic materials with varying coefficients of thermal expansion have to be sealed gastight and electrical insulating at temperatures between 850 C and 1000 C to prevent the gases from mixing and an electrical shortcut between the cells. This work comprises analysis of commercially available glass and glass-ceramic systems manufactured by Schott Electronic Packaging, Areva T and D and Ferro Corporation. Additionally new developed sealing glass and glass-ceramic systems were investigated and all systems were characterized fundamentally for the use as sealing material in SOFC generators. Therefore different test assemblies and series were conducted. Essential characteristics of a suitable sealing system are a thermal expansion coefficient between 9,5 and 12 . 10{sup -6}K{sup -1}, a viscosity in the range between 10{sup 4} to 10{sup 6} dPa{sup *}s and a wetting angle smaller than 90 during the sealing process. Also unwanted chemical side reactions between the sealing partners must be prevented, because a change in the phase composition or the creation of new phases in the sealing material could endanger the stability of the seal. Heat cycles, particularly those during generator operation, cause deterioration of the sealing material and subsequent reduction in its ability to prevent mixing of the gases. Sealant leaks can drastically impact efficiency of the generator. In order to ensure optimum operation low leak rates around 2,3 . 10{sup -4} mbar l/sec/cm{sup 2} must be maintained. Especially glass and glass

  18. Replacement of nickel sealing rings by expanded graphite sealing rings -upgrading of SG primary collector flange connection

    Energy Technology Data Exchange (ETDEWEB)

    Cikryt, F.; Bednarek, L.; Kusyn, L. [Vitkovice, Ostrava (Switzerland)

    1997-12-31

    One of the most loaded parts of a steam generator of VVER 440 MW type are the bolts and thread holes of the primary collector cover sealing set. The strength calculations and tensometric measurings performed during operation proved the high degree of a load on the bolts. The conditions of the stress limitation are not met in some cases according to the pertinent standards. The untightnesses at nickel rings occurred during putting the units of Jaslovske Bohunice and Dukovany nuclear power stations into operation. With regard to improve the reliability, the producer has taken measures to improve the quality of the rings and users have introduced more strict regulations for bolts tightening. Due to these measures the high reliability of the set has been obtained from point of view of the tightness, but substantial reduction of bolts and holes threads loading have not been obtained. Several years operation experience proved relatively low service of bolts, damage of thread holes and sealing grooves. As the degree of mechanical load is one of the vital parameters influencing the damage of sealing set, in 1996 we started with the works aimed at a possibility of nickel sealing rings replacement for a more modern type of sealing which assure the higher reliability and service life of the individual part of sealing set under the reduced load.

  19. Replacement of nickel sealing rings by expanded graphite sealing rings -upgrading of SG primary collector flange connection

    Energy Technology Data Exchange (ETDEWEB)

    Cikryt, F; Bednarek, L; Kusyn, L [Vitkovice, Ostrava (Switzerland)

    1998-12-31

    One of the most loaded parts of a steam generator of VVER 440 MW type are the bolts and thread holes of the primary collector cover sealing set. The strength calculations and tensometric measurings performed during operation proved the high degree of a load on the bolts. The conditions of the stress limitation are not met in some cases according to the pertinent standards. The untightnesses at nickel rings occurred during putting the units of Jaslovske Bohunice and Dukovany nuclear power stations into operation. With regard to improve the reliability, the producer has taken measures to improve the quality of the rings and users have introduced more strict regulations for bolts tightening. Due to these measures the high reliability of the set has been obtained from point of view of the tightness, but substantial reduction of bolts and holes threads loading have not been obtained. Several years operation experience proved relatively low service of bolts, damage of thread holes and sealing grooves. As the degree of mechanical load is one of the vital parameters influencing the damage of sealing set, in 1996 we started with the works aimed at a possibility of nickel sealing rings replacement for a more modern type of sealing which assure the higher reliability and service life of the individual part of sealing set under the reduced load.

  20. Application of radioisotope technique for investigation of pumps seals

    International Nuclear Information System (INIS)

    Antoszewski, B.; Zorawska, A.

    1988-01-01

    Radioisotope method of measuring the wear of rings of the face mechanical seals, bush in soft seals, and leakage in double mechanical seals is described. The examples are given. It is found that radioisotope technique can be used for investigation of the seals. (author)

  1. Legacy HMSRP Hawaiian Monk Seals Observers

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set documents observers that have collected monk seal data as part of the ongoing monk seal population assessment efforts by PSD personnel and cooperating...

  2. HMSRP Hawaiian Monk Seal Entanglement data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data set contains records of all entanglements of Hawaiian monk seals in marine debris. The data set comprises records of seals entangled by derelict fishing...

  3. Salt brickwork as long-term sealing in salt formations

    International Nuclear Information System (INIS)

    Walter, F.; Yaramanci, U.

    1993-01-01

    Radioactive wastes can be disposed of in deep salt formations. Rock salt is a suitable geologic medium because of its unique characteristics. Open boreholes, shafts and drifts are created to provide physical access to the repository. Long-term seals must be emplaced in these potential pathways to prevent radioactive release into the biosphere. The sealing materials must be mechanically and, most important, geochemically stable within the host rock. Salt bricks made from compressed salt-powder are understood to be the first choice long-term sealing material. Seals built of salt bricks will be ductile. Large sealing systems are built by combining the individual bricks with mortar. Raw materials for mortar are fine-grained halite powder and ground saliferous clay. This provides for the good adhesive strength of the mortar to the bricks and the high shear-strength of the mortar itself. To test the interaction of rock salt with an emplaced long-term seal, experiments will be carried out in situ, in the Asse salt mine in Germany. Simple borehole sealing experiments will be performed in horizontal holes and a complicated drift sealing experiment is planned, to demonstrate the technology of sealing a standard size drift or shaft inside a disturbed rock mass. Especially, the mechanical stability of the sealing system has to be demonstrated

  4. Sealed source peer review plan

    International Nuclear Information System (INIS)

    Feldman, Alexander; Leonard, Lee; Burns, Ron

    2009-01-01

    Sealed sources are known quantities of radioactive materials that have been encapsulated in quantities that produce known radiation fields. Sealed sources have multiple uses ranging from instrument calibration sources to sources that produce radiation fields for experimental applications. The Off-Site Source Recovery (OSR) Project at Los Alamos National Laboratory (LANL), created in 1999, under the direction of the Waste Management Division of the U.S. Department of Energy (DOE) Albuquerque has been assigned the responsibility to recover and manage excess and unwanted radioactive sealed sources from the public and private sector. LANL intends to ship drums containing qualified sealed sources to the Waste Isolation Pilot Plant (WIPP) for disposal. Prior to shipping, these drums must be characterized with respect to radiological content and other parameters. The U. S. Environmental Protection Agency (EPA) requires that ten radionulcides be quantified and reported for every container of waste to be disposed in the WIPP. The methods traditionally approved by the EPA include non-destructive assay (NDA) in accordance with Appendix A of the Contact-Handled Transuranic Waste Acceptance Criteria for the Waste Isolation Pilot Plant (DOE, 2002) (CH WAC). However, because of the nature and pedigree of historical records for sealed sources and the technical infeasibility of performing NDA on these sources, LANL proposes to characterize the content of these waste drums using qualified existing radiological data in lieu of direct measurement. This plan describes the process and documentation requirements for the use of the peer review process to qualify existing data for sealed radiological sources in lieu of perfonning radioassay. The peer review process will be performed in accordance with criteria provided in 40 CFR (section) 194.22 which specifies the use of the NUREG 1297 guidelines. The plan defines the management approach, resources, schedule, and technical requirements

  5. Molybdenum sealing glass-ceramic composition

    International Nuclear Information System (INIS)

    Eagan, R.J.

    1976-01-01

    A glass-ceramic composition is described having low hydrogen and helium permeability properties, along with high fracture strength, and a thermal coefficient of expansion similar to that of molybdenum. The composition is adaptable for hermetically sealing to molybdenum at temperatures between 900 and about 950 0 C to form a hermetically sealed insulator body

  6. Acoustic resonance spectroscopy intrinsic seals

    International Nuclear Information System (INIS)

    Olinger, C.T.; Burr, T.; Vnuk, D.R.

    1994-01-01

    We have begun to quantify the ability of acoustic resonance spectroscopy (ARS) to detect the removal and replacement of the lid of a simulated special nuclear materials drum. Conceptually, the acoustic spectrum of a container establishcs a baseline fingerprint, which we refer to as an intrinsic seal, for the container. Simply removing and replacing the lid changes some of the resonant frequencies because it is impossible to exactly duplicate all of the stress patterns between the lid and container. Preliminary qualitative results suggested that the ARS intrinsic seal could discriminate between cases where a lid has or has not been removed. The present work is directed at quantifying the utility of the ARS intrinsic seal technique, including the technique's sensitivity to ''nuisance'' effects, such as temperature swings, movement of the container, and placement of the transducers. These early quantitative tests support the potential of the ARS intrinsic seal application, but also reveal a possible sensitivity to nuisance effects that could limit environments or conditions under which the technique is effective

  7. Precipitate-induced R-phase in martensitic transformation of as-spun and annealed Ti51Ni49 ribbons

    International Nuclear Information System (INIS)

    Wu, Ling-Mei; Chang, Shih-Hang; Wu, Shyi-Kaan

    2010-01-01

    Differential scanning calorimetry (DSC) results indicate that a two-step B2 → R → B19' martensitic transformation and a one-step B19' → B2 transformation exhibit in as-spun and in 200-600 o C annealed Ti 51 Ni 49 ribbons. Guinier-Preston (GP) zones and Ti 2 Ni precipitates are formed in ribbons annealed at ≤300 o C and ≥400 o C, respectively, and a conspicuous increase of DSC transformation peak temperature occurs in between 300 o C and 400 o C. The sizes of GP zones and Ti 2 Ni precipitates increase with increased annealing temperature. Transmission electron microscope (TEM) observations show that GP zones can induce the R-phase and both of them are formed along B2 directions. DSC and TEM tests show that Ti 2 Ni precipitates can induce the R-phase more than GP zones and the induced R-phase plates are also found along B2 directions. Experimental results show that the growing direction of R-phase plates is strongly confined by that of GP zones and Ti 2 Ni precipitates. The length of R-phase plates can reach about 2 μm in 300 o C annealed ribbon.

  8. Pillow seal system at the BigRIPS separator

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, K., E-mail: ktanaka@riken.jp; Inabe, N.; Yoshida, K.; Kusaka, K.; Kubo, T.

    2013-12-15

    Highlights: • Pillow seal system has been installed for a high-intensity RI-beam facility at RIKEN. • It is aimed at facilitating remote maintenance under high residual radiation. • Local radiation shields are integrated with one of the pillow seals. • Pillow seals have been aligned to the beam axis within 1mm accuracy. • A leakage rate of 10{sup –9} Pa m{sup 3}/s has been achieved with our pillow seal system. -- Abstract: We have designed and installed a pillow seal system for the BigRIPS fragment separator at the RIKEN Radioactive Isotope Beam Factory (RIBF) to facilitate remote maintenance in a radioactive environment. The pillow seal system is a device to connect a vacuum chamber and a beam tube. It allows quick attachment and detachment of vacuum connections in the BigRIPS separator and consists of a double diaphragm with a differential pumping system. The leakage rate achieved with this system is as low as 10{sup –9} Pa m{sup 3}/s. We have also designed and installed a local radiation-shielding system, integrated with the pillow seal system, to protect the superconducting magnets and to reduce the heat load on the cryogenic system. We present an overview of the pillow seal and the local shielding systems.

  9. Plastic profiled sealing element for household refrigeration appliances

    Energy Technology Data Exchange (ETDEWEB)

    Wunderlich, E; Robl, G

    1988-12-28

    A plastic profiled sealing element for household refrigeration appliances, such as freezers, refrigerators, and freezer compartments, includes a sealing bellows having a hose-shaped cross section. The sealing bellows is provided with two side walls and a covering wall, and is made of a plastic that has been set by means of a softener so as to be continuously flexible. Further, the profiled sealing element is provided with an anchor member made of a plastic of the same or different material hardness, with the sealing bellows and the anchor member being connected with one another to form a unit. The cross sections of the two side walls of the sealing bellows narrow as the side walls rise from the region of the connection of the side walls with the covering wall of the anchor member to approximately half the height of the sealing bellows, so that the side walls become increasingly thinner. Thereafter, the cross sections of the side walls increase again to the edges of the covering wall of the sealing bellows, until the side walls again reach approximately their initial cross sections. The side walls, on the one hand, and the covering wall, on the other hand, are kept flexible by means of softeners having different characteristics.

  10. Dynamics of face seals for high speed turbomachinery

    Science.gov (United States)

    Leefe, Simon

    1993-10-01

    Face seals in rocket engine fuel and oxidizer turbopumps have been the subject of intense investigation for over 25 years. While advances have been made in the understanding of thin film lubrication between seal faces, valuable data has been produced on the friction and wear of material pairs in cryogenic environments; pioneering work has been done on the effect of lubricant phase change in seals, and many improvements have been made in mechanical seal design. Relatively superficial attention has been given to the vibrational dynamics of face seals in high-speed turbomachinery. BHR Group Ltd. (formerly BHRA) has recently completed the first stage of a study, commissioned by the European Space Agency, to investigate this area. This has involved the development of a two-dimensional adiabatic, turbulent lubrication model for thick gas film applications, the production of an integrated mathematical model of gas seal vibrational dynamics for thin film applications, implementation in software, the undertaking of an experimental program to validate software against variations in operating conditions and design variables, and suggestions for improved seal design.

  11. HMSRP Hawaiian Monk Seal Handling Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains records for all handling and measurement of Hawaiian monk seals since 1981. Live seals are handled and measured during a variety of events...

  12. 39 CFR 2.4 - Seal.

    Science.gov (United States)

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Seal. 2.4 Section 2.4 Postal Service UNITED STATES... Secretary of State, and is required by 39 U.S.C. 207 to be judicially noticed. The Seal shall be in the... description of the Postal Service emblem is described at 39 CFR 221.7. ...

  13. Magnetic shaft seals prevent hazardous leakage from wastewater agitators

    International Nuclear Information System (INIS)

    Traino, F.A.

    1985-01-01

    The US Department of Energy's laboratory in Miamisburg, OH, operated by Monsanto Research Corporation, processes approximately 45,000 gallons per week of low-level radioactive wastewater to meet Federal Environmental Protection Agency quality standards. Preventing the spread of radioactive contamination throughout the operating area demands effective sealing of all process piping, valves, pumps, and agitators. Rotating shafts of pumps and agitators installed a the start of operations in 1947 were sealed by stuffing glands with graphite impregnated asbestos packing. These pumps proved to be unsatisfactory. In the mid-1970's, new process pumps with mechanical seals and some with magnetic drives were installed. Later, in January 1979, new agitator shaft drives with double tandem, spring-loaded mechanical seals were installed, maintenance of these pumps was costly. The agitator drive shafts were redesigned to accommodate magnetic seals of the type successfully used in blowers and vacuum/pressure pumps in other plant locations. One inherent advantage of the magnetic seal is that it operates with a face loading as much as 50% less than a conventional spring-loaded mechanical seal. The lower loading by a predetermined uniform magnetic force contributes to long face life. Other advantages include compactness, ease of assembly with only a few parts, and insensitivity to vibration. The magnetic shaft seals installed on the agitator shafts in February 1983 are still in service without any leakage or need for maintenance. Based on current operating data and a projected five-year meantime between failures, the estimated cost benefit of the magnetic seals over spring-loaded mechanical seals over spring-loaded mechanical seals will be $640 vs $2400 respectively per seal, with 60% less downtime for maintenance

  14. Experimental investigation on flow and heat transfer for cooling flush-mounted ribbons in a channel: Application of an EHD active enhancement method

    Directory of Open Access Journals (Sweden)

    Alami Nia Amin

    2016-01-01

    Full Text Available In the present study, the heat transfer enhancement of a bundle of flush-mounted ribbons placed on the floor of a rectangular duct was investigated experimentally. The flush-mounted ribbons act as heat sources and the cooling happens with air. The air flow was two-dimensional, steady, viscous and incompressible under either laminar (500 ≤ ReDh < 2000 and turbulent (2000 ≤ Re Dh ≤ 4500 conditions. The hydrodynamics and heat transfer behavior of the air flow was studied by means of an active method with application of corona wind. The state of the art of this work revolves around an experimental investigation of an EHD1 active method and heat transfer enhancement from the surfaces of the flush- mounted ribbons. Due to the intricacies of the required experiment, a special apparatus needed to be designed and constructed.

  15. Performances of Magnetic Fluid Seal and Application to Turbopumps

    OpenAIRE

    北洞, 貴也; 黒川, 淳一; 宮副, 雄貴; 林, 正悦

    1994-01-01

    A magnetic fluid shaft seal can achieve zero-leakage and operate stably against shaft vibration, but the sealing pressure is very low. In order to improve the pressure performance of a magnetic fluid seal and apply it to a turbopump, the seal pressure characteristics are studied theoretically and experimentally. The Poisson equation for magnetic vector potential is solved by FEM, and the seal performances are determined by use of the Bernoulli equation. The validity of the theory is confirmed...

  16. Knife-edge seal for vacuum bagging

    Science.gov (United States)

    Rauschl, J. A.

    1980-01-01

    Cam actuated clamps pinch bagging material between long knife edge (mounted to clamps) and high temperature rubber cushion bonded to baseplate. No adhesive, tape, or sealing groove is needed to seal edge of bagging sheet against base plate.

  17. Verification on reliability of diaphragm seal

    International Nuclear Information System (INIS)

    Ide, Hiroshi; Sakuta, Yoshiyuki; Hanawa, Yoshio; Tsuji, Tomoyuki; Tsuboi, Kazuaki; Nagao, Yoshiharu; Miyazawa, Masataka

    2009-06-01

    The main body of the JMTR is composed of reactor pressure vessel, core and reactor pool. At the bottom of the reactor pool, the Diaphragm-seal (2.6m outer diameter, 2m inner diameter, thickness 1.5mm) of the JMTR made of stainless steel is installed to prevent the water leak of the reactor pool and to absorb the expansion of the reactor pressure vessel due to pressure and temperature changes. In the long-term maintenance plans drawn up in 2004, it is required that the visual inspection for the diaphragm-seal should be carried out in 2007 and that the inspection should be carried out every around five-year. Therefore, prior to the refurbishment of the JMTR, the inspection device which is a deposition-collection apparatus with underwater-camera was developed, and the visual inspection was carried out to confirm the soundness of the diaphragm-seal. As a result, harmful flaws and/or corrosions were not inspected in the visual inspection, and the soundness of the diaphragm seal was confirmed. In future, the long-term integrity of the diaphragm-seal will could be achieved by conducting the periodic inspection. (author)

  18. Sealing of investigation boreholes, Phase 4 - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Drawrite AB, Luleaa Technical University, Luleaa (Sweden); Ramqvist, Gunnar [El-Tekno AB, Figeholm (Sweden); Bockgaard, Niclas [Golder Associates, Goeteborg (Sweden); Ekman, Lennart [LE Geokonsult AB, Baelinge (Sweden)

    2011-09-15

    The report describes the outcome of Phase 4 of the project 'Sealing of investigation boreholes', which deals with 1) characterization and planning of borehole sealing, 2) performance and quality assessment, 3) sealing of large diameter holes, and 4) interaction of clay and concrete plugs. A specific goal was to find ways to characterize, plan and seal of boreholes so that their impact on the overall hydraulic performance of the repository rock can predicted and controlled. The work comprised selection of representative 'reference holes' at the Laxemar and Forsmark sites for development of a general programme for planning and simulating implementation of borehole plugging campaigns, considering also cost issues. A second aim was to define and quantify the role of seals in the reference holes for finding out how important sealing really is. A third was to test a practical way to seal large diameter boreholes and a fourth to find out how concrete matures and performs in contact with smectite clay. The study demonstrated, in conclusion, the need for developing techniques for preparing deep boreholes before lasting seals are installed in them, since poor sealing can short-circuit hydraulically important fracture zones intersected by the holes. The practically oriented sealing activities showed that the technique developed for tight sealing of large-diameter boreholes is practical and feasible. The issue of chemical stability was investigated by testing the performance and constitution of a plug consisting of CBI concrete in contact with smectite-rich seals for almost three years. This study showed that none of them underwent substantial degradation in this period of time, but chemical reactions and thereby generated changes in physical behaviour of the plug components had taken place, particularly in the clay. The rate of degradation is, however, not yet known. It was concluded from this study that it is suitable to carry out a corresponding

  19. Sealing of investigation boreholes, Phase 4 - Final report

    International Nuclear Information System (INIS)

    Pusch, Roland; Ramqvist, Gunnar; Bockgaard, Niclas; Ekman, Lennart

    2011-09-01

    The report describes the outcome of Phase 4 of the project 'Sealing of investigation boreholes', which deals with 1) characterization and planning of borehole sealing, 2) performance and quality assessment, 3) sealing of large diameter holes, and 4) interaction of clay and concrete plugs. A specific goal was to find ways to characterize, plan and seal of boreholes so that their impact on the overall hydraulic performance of the repository rock can predicted and controlled. The work comprised selection of representative 'reference holes' at the Laxemar and Forsmark sites for development of a general programme for planning and simulating implementation of borehole plugging campaigns, considering also cost issues. A second aim was to define and quantify the role of seals in the reference holes for finding out how important sealing really is. A third was to test a practical way to seal large diameter boreholes and a fourth to find out how concrete matures and performs in contact with smectite clay. The study demonstrated, in conclusion, the need for developing techniques for preparing deep boreholes before lasting seals are installed in them, since poor sealing can short-circuit hydraulically important fracture zones intersected by the holes. The practically oriented sealing activities showed that the technique developed for tight sealing of large-diameter boreholes is practical and feasible. The issue of chemical stability was investigated by testing the performance and constitution of a plug consisting of CBI concrete in contact with smectite-rich seals for almost three years. This study showed that none of them underwent substantial degradation in this period of time, but chemical reactions and thereby generated changes in physical behaviour of the plug components had taken place, particularly in the clay. The rate of degradation is, however, not yet known. It was concluded from this study that it is suitable to carry out a corresponding investigation of the plugs

  20. Magnetic vector field tag and seal

    Science.gov (United States)

    Johnston, Roger G.; Garcia, Anthony R.

    2004-08-31

    One or more magnets are placed in a container (preferably on objects inside the container) and the magnetic field strength and vector direction are measured with a magnetometer from at least one location near the container to provide the container with a magnetic vector field tag and seal. The location(s) of the magnetometer relative to the container are also noted. If the position of any magnet inside the container changes, then the measured vector fields at the these locations also change, indicating that the tag has been removed, the seal has broken, and therefore that the container and objects inside may have been tampered with. A hollow wheel with magnets inside may also provide a similar magnetic vector field tag and seal. As the wheel turns, the magnets tumble randomly inside, removing the tag and breaking the seal.

  1. Radioactive material package seal tests

    International Nuclear Information System (INIS)

    Madsen, M.M.; Humphreys, D.L.; Edwards, K.R.

    1990-01-01

    General design or test performance requirements for radioactive materials (RAM) packages are specified in Title 10 of the US Code of Federal Regulations Part 71 (US Nuclear Regulatory Commission, 1983). The requirements for Type B packages provide a broad range of environments under which the system must contain the RAM without posing a threat to health or property. Seals that provide the containment system interface between the packaging body and the closure must function in both high- and low-temperature environments under dynamic and static conditions. A seal technology program, jointly funded by the US Department of Energy Office of Environmental Restoration and Waste Management (EM) and the Office of Civilian Radioactive Waste Management (OCRWM), was initiated at Sandia National Laboratories. Experiments were performed in this program to characterize the behavior of several static seal materials at low temperatures. Helium leak tests on face seals were used to compare the materials. Materials tested include butyl, neoprene, ethylene propylene, fluorosilicone, silicone, Eypel, Kalrez, Teflon, fluorocarbon, and Teflon/silicone composites. Because most elastomer O-ring applications are for hydraulic systems, manufacturer low-temperature ratings are based on methods that simulate this use. The seal materials tested in this program with a fixture similar to a RAM cask closure, with the exception of silicone S613-60, are not leak tight (1.0 x 10 -7 std cm 3 /s) at manufacturer low-temperature ratings. 8 refs., 3 figs., 1 tab

  2. 2005 NASA Seal/Secondary Air System Workshop, Volume 1

    Science.gov (United States)

    Steinetz, Bruce M. (Editor); Hendricks, Robert C. (Editor)

    2006-01-01

    The 2005 NASA Seal/Secondary Air System workshop covered the following topics: (i) Overview of NASA s new Exploration Initiative program aimed at exploring the Moon, Mars, and beyond; (ii) Overview of the NASA-sponsored Propulsion 21 Project; (iii) Overview of NASA Glenn s seal project aimed at developing advanced seals for NASA s turbomachinery, space, and reentry vehicle needs; (iv) Reviews of NASA prime contractor, vendor, and university advanced sealing concepts including tip clearance control, test results, experimental facilities, and numerical predictions; and (v) Reviews of material development programs relevant to advanced seals development. Turbine engine studies have shown that reducing high-pressure turbine (HPT) blade tip clearances will reduce fuel burn, lower emissions, retain exhaust gas temperature margin, and increase range. Several organizations presented development efforts aimed at developing faster clearance control systems and associated technology to meet future engine needs. The workshop also covered several programs NASA is funding to develop technologies for the Exploration Initiative and advanced reusable space vehicle technologies. NASA plans on developing an advanced docking and berthing system that would permit any vehicle to dock to any on-orbit station or vehicle. Seal technical challenges (including space environments, temperature variation, and seal-on-seal operation) as well as plans to develop the necessary "androgynous" seal technologies were reviewed. Researchers also reviewed tests completed for the shuttle main landing gear door seals.

  3. 75 FR 53711 - Narrow Woven Ribbons With Woven Selvedge From China and Taiwan

    Science.gov (United States)

    2010-09-01

    ... Woven Ribbons With Woven Selvedge From China and Taiwan Determinations On the basis of the record \\1... U.S.C. 1673d(b)) (the Act), that an industry in the United States is threatened with material injury... (19 U.S.C. 1673d(b)), that an industry in the United States is threatened with material injury by...

  4. Mechanical seal monitoring technique by acoustic emission measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, Tadashi; Fujita, Yoshihiro; Kawaguchi, Kazunori; Saito, Kazuhiro; Yokota, Setsuo; Hisada, Yasuhide; Masahiro, Komatsu

    1987-09-20

    This report describes a technique for mechanical seal monitoring through acoustic emission (AE) measurement. The equipment consists of an AE sensor, preamplifier, multiplexer, main amplifier, effective value transducer and computer system. When the sealed liquid pressure undergoes a large change, the seal surface configuration is monitored and evaluated accurately through AE measurement. If the mechanical seal surface id damaged or worn, the AE level is kept high or continues to fluctuate largely for a rather long period. When leak occurs, the AE value shows great fluctuations either at extremely low levels or at high levels. The former trend is considered to result from a decrease in solid contact due to an excessive amount of liquid film being formed at the seal surface during leak. In the latter case, the leak is attributed to severe damage to the seal surface. (18 figs, 1 tab, 5 photos, 3 refs)

  5. The southern elephant seal Mirounga leonina at Gough Island

    African Journals Online (AJOL)

    haul-out in December coincided with the elephant seal moulting season, the elephant seals were found on the vegetated areas whilst the majority of fur seals hauled out onto the boulder beach. No interactions between the two species were recorded. Potential predators of elephant seals, i.e. the killer whales Orcinus orca ...

  6. Application of hydrophilic magnetic fluid to oil seal

    Science.gov (United States)

    Kim, Y. S.; Nakatsuka, K.; Fujita, T.; Atarashi, T.

    1999-07-01

    Bearing and gear are important components in machines. Lubricant for bearing or gear is usually confined in working space by rubber retainer or mechanical seal, and its lifetime which is determined by the friction wear of sealing material is important. In this report, the basic characteristics of magnetic fluid seal applied to lubricant retainer is studied. The fluid used for this purpose is ethyleneglycol-based magnetic fluid in which silica-coated iron particles are dispersed. The lubricant oil seal set consisting of six stages of pole piece and Nd-permanent magnets (4.0 Wb/m 2) in seal housing showed an excellent pressure resistance of 618 kPa under a rotating speed of 1800 rpm.

  7. A new ribbon-ignition method for fabricating p-CuO/n-CeO{sub 2} heterojunction with enhanced photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ning [School of Materials Science and Engineering, Southeast University, Jiangsu Key Laboratory for Advanced Metallic Materials, Nanjing 211189 (China); Pan, Ye, E-mail: panye@seu.edu.cn [School of Materials Science and Engineering, Southeast University, Jiangsu Key Laboratory for Advanced Metallic Materials, Nanjing 211189 (China); Lu, Tao; Li, Xingzhou; Wu, Shikai [School of Materials Science and Engineering, Southeast University, Jiangsu Key Laboratory for Advanced Metallic Materials, Nanjing 211189 (China); Wu, Jili [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China)

    2017-05-01

    Highlights: • A novel ribbon-ignition method was carried out to fabricate p-CuO/n-CeO{sub 2} heterojunction. • Cu-Ce binary amorphous ribbons are chosen as precursors. • Ribbon-ignition method has many advantages compared to traditional solution-based methods. • The CuO/CeO{sub 2} exhibited enhanced photodegradation activity towards RhB. • The formation of p-type CuO/n-type CeO{sub 2} heterojunction can promote the separation and transfer of the photoinduced carriers, resulting in the enhanced photocatalytic activity. - Abstract: The p-type CuO/n-type CeO{sub 2} heterojunction photocatalyst was synthesized by a facile combination of ribbon-ignition and calcination methods using Cu-Ce amorphous ribbons as precursors. The synthesized sample was characterized by X-ray diffraction (XRD), fourier transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectroscopy (DRS). XRD, FTIR and XPS reveal the successful synthesis of CuO/CeO{sub 2} composite. The SEM and TEM images show that the sample consists of large amounts of well-dispersed blocky-shaped particles with the size distribution from 20 nm to 2 μm. DRS exhibits the absorption band (about 491 nm) and the band gap energy (2.59 eV) of the CuO/CeO{sub 2} composite. The photocatalytic activities of the samples were evaluated by degrading rhodamine B (RhB) dye (10 mg/L) under visible light (λ > 420 nm) irradiation. Compared with pure CuO and CeO{sub 2}, the CuO/CeO{sub 2} exhibited significantly enhanced photocatalytic degradation activity. The reaction rate constant of CuO/CeO{sub 2} is 0.18 min{sup −1}, which is much higher than those of CuO (0.12 min{sup −1}) and CeO{sub 2} (0.10 min{sup −1}).

  8. Windpower and grey seals: An impact assessment of potential effects by sea-based windpower plants in a local seal population

    International Nuclear Information System (INIS)

    Sundberg, Jan; Soederman, Malin

    2000-05-01

    The impact of five sea-based wind power plants on two haulout sites for grey seals on southwestern Gotland, in the Baltic Sea, was analysed. Data on seal numbers was collected on a regular basis during the initial stages of the project from summer 1996, continuing during the building (autumn 1997) and running of the wind power plants (from spring 1998) until the end of June 1999. Additional observational data from earlier years was also available. Indications of lower occurrence and reduced number of seals in the area was found during periods of time in 1997 and 1998, times of construction and active running of the plants. However, no evidence on the wind power plants, per se, affecting the grey seals was found. Instead, several weather factors were found to affect the number of seals in the area, and periods of low occurrence and number of seals were more likely explained by i.e. unfavourable water levels and hard wind from certain directions. One important, short term, impact factor was however found. Human induced disturbances such as boat and helicopter traffic, some which were directly related to maintenance of the wind power plants, temporarily reduced number of seals and made them more restless. Disturbance thus constitutes a potential threat to seals. A shift from one to the other of the two haulout sites was also noted, a shift which likely is due to disturbances. Future guidelines are given, including some restrictions in movements near the haulout sites. Continued observations and studies are suggested if more off-shore wind power plants will be raised in the area. A call for more stringent use of environmental impact assessments is thus made. Also, suggestions on measures to be taken in order to reduce the effect of human related disturbances are made. In order to create sustainable conditions for a continued population of seals in the area and in order to create opportunities for a reestablishment of the grey seal in the southern Baltic region

  9. Windpower and grey seals: An impact assessment of potential effects by sea-based windpower plants in a local seal population

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, Jan; Soederman, Malin [Uppsala Univ. (Sweden). Dept. of Animal Ecology

    2000-05-01

    The impact of five sea-based wind power plants on two haulout sites for grey seals on southwestern Gotland, in the Baltic Sea, was analysed. Data on seal numbers was collected on a regular basis during the initial stages of the project from summer 1996, continuing during the building (autumn 1997) and running of the wind power plants (from spring 1998) until the end of June 1999. Additional observational data from earlier years was also available. Indications of lower occurrence and reduced number of seals in the area was found during periods of time in 1997 and 1998, times of construction and active running of the plants. However, no evidence on the wind power plants, per se, affecting the grey seals was found. Instead, several weather factors were found to affect the number of seals in the area, and periods of low occurrence and number of seals were more likely explained by i.e. unfavourable water levels and hard wind from certain directions. One important, short term, impact factor was however found. Human induced disturbances such as boat and helicopter traffic, some which were directly related to maintenance of the wind power plants, temporarily reduced number of seals and made them more restless. Disturbance thus constitutes a potential threat to seals. A shift from one to the other of the two haulout sites was also noted, a shift which likely is due to disturbances. Future guidelines are given, including some restrictions in movements near the haulout sites. Continued observations and studies are suggested if more off-shore wind power plants will be raised in the area. A call for more stringent use of environmental impact assessments is thus made. Also, suggestions on measures to be taken in order to reduce the effect of human related disturbances are made. In order to create sustainable conditions for a continued population of seals in the area and in order to create opportunities for a reestablishment of the grey seal in the southern Baltic region

  10. Seals, Concrete Anchors, and Connections

    Science.gov (United States)

    1989-02-01

    caulking compounds, nonhardening extruded tapes, nonhardening mastics, strippable spray coatings, pressure sensitive tapes, gaskets, adhesives, fabrics...films, etc. Although all of these materials may provide a seal, care must be taken when selecting a sealing material as to its chemical and...gaskets have performed satisfactorily. Another factor to be considered in the selection of gasketing material is its compatibility with both the

  11. Basis of property limits for inflatable seal fluoroelastomers

    International Nuclear Information System (INIS)

    Sinha, N.K.; Raj, Baldev

    2012-01-01

    Identification of a set of governing physico-mechanical properties for inflatable seals of Prototype Fast Breeder Reactor (PFBR) and specification of their limits is described based on operating requirements, design practices and results from seal development. The limits of tensile strength, elongation at break, hardness, tear strength, fluid compatibility, compression set and specific gravity defined for the Viton GBL 200S/600S based inflatable seal formulation provide a standardized framework for regular production of reactor seals and a streamlined approach for compounding, design, manufacture and quality control. This assures significant reduction of efforts during the envisaged unification of Fast Breeder Reactor sealing based on four variations of inflatable seal compound which could result in a universal design code apart from significant gains in safety, reliability and life. The property set has potential use in Pressurized Heavy Water Reactor and Advanced Heavy Water Reactor. Inclusion of factors such as batch-to-batch variations of compound properties and their reproducibility during laboratory measurements, hot tensile behavior of fluoroelastomer, long term ageing effects and the margin of safety at the end of seal design life ensures the utility of property set in attaining its intended objective.

  12. Mechanical seal with textured sidewall

    Energy Technology Data Exchange (ETDEWEB)

    Khonsari, Michael M.; Xiao, Nian

    2017-02-14

    The present invention discloses a mating ring, a primary ring, and associated mechanical seal having superior heat transfer and wear characteristics. According to an exemplary embodiment of the present invention, one or more dimples are formed onto the cylindrical outer surface of a mating ring sidewall and/or a primary ring sidewall. A stationary mating ring for a mechanical seal assembly is disclosed. Such a mating ring comprises an annular body having a central axis and a sealing face, wherein a plurality of dimples are formed into the outer circumferential surface of the annular body such that the exposed circumferential surface area of the annular body is increased. The texture added to the sidewall of the mating ring yields superior heat transfer and wear characteristics.

  13. Investigation of brush seals for application in steam turbines

    International Nuclear Information System (INIS)

    Zorn, Peter

    2012-01-01

    Brush seals have high potential for efficiency increase compared to conventional labyrinth seals in steam turbines. Due to less experience in operation today there is a lot of scepticism with customers of steam turbine manufacturers. Therefore this thesis is investigating characteristics of this type of seal. Experiments and numerical models will be presented, which lead to better knowledge about leakages and influence of flow through seal onto dynamics of rotor in comparison to labyrinth seals. This thesis is increasing area of experience and one more positive reference.

  14. Effect of Al substitution for B on magnetic and structural properties of Co-based melt-spun ribbons

    International Nuclear Information System (INIS)

    Sepehri Amin, H.; Gholamipour, R.; Shahri, F.; Mohammadi, A.

    2008-01-01

    This paper reports structural and magnetic properties of rapidly quenched Co 64 Fe 4 Ni 2 B 19-x Si 8 Cr 3 Al x (x=0, 1, 2, 3) amorphous ribbons prepared by the single roller melt spinning process. Thermal analysis of the ribbons shows that the replacement of B by Al causes a decrease in the crystallization temperature. Structural studies of the samples have been carried out by transmission electron microscopy and X-ray diffraction. With optimum amount of Al in the alloy, the as-cast material has better soft magnetic properties. The highest maximum permeability (3.55x10 5 ), saturation magnetization (523.7 mT) and the lowest coercivity (0.8174 A/m) were obtained in the sample with x=2

  15. Gas-path leakage seal for a gas turbine

    Science.gov (United States)

    Wolfe, C.E.; Dinc, O.S.; Bagepalli, B.S.; Correia, V.H.; Aksit, M.F.

    1996-04-23

    A gas-path leakage seal is described for generally sealing a gas-path leakage-gap between spaced-apart first and second members of a gas turbine (such as combustor casing segments). The seal includes a generally imperforate foil-layer assemblage which is generally impervious to gas and is located in the leakage-gap. The seal also includes a cloth-layer assemblage generally enclosingly contacting the foil-layer assemblage. In one seal, the first edge of the foil-layer assemblage is left exposed, and the foil-layer assemblage resiliently contacts the first member near the first edge to reduce leakage in the ``plane`` of the cloth-layer assemblage under conditions which include differential thermal growth of the two members. In another seal, such leakage is reduced by having a first weld-bead which permeates the cloth-layer assemblage, is attached to the metal-foil-layer assemblage near the first edge, and unattachedly contacts the first member. 4 figs.

  16. Dye filled security seal

    International Nuclear Information System (INIS)

    Wilson, D.C.

    1982-01-01

    A security seal for providing an indication of unauthorized access to a sealed object includes an elongate member to be entwined in the object such that access is denied unless the member is removed. The elongate member has a hollow, pressurizable chamber extending throughout its length that is filled with a permanent dye under greater than atmospheric pressure. Attempts to cut the member and weld it together are revealed when dye flows through a rupture in the chamber wall and stains the outside surface of the member

  17. Fuel cell cassette with compliant seal

    Science.gov (United States)

    Karl, Haltiner, Jr. J.; Anthony, Derose J.; Klotzbach, Darasack C.; Schneider, Jonathan R.

    2017-11-07

    A fuel cell cassette for forming a fuel cell stack along a fuel cell axis includes a cell retainer, a plate positioned axially to the cell retainer and defining a space axially with the cell retainer, and a fuel cell having an anode layer and a cathode layer separated by an electrolyte layer. The outer perimeter of the fuel cell is positioned in the space between the plate and the cell retainer, thereby retaining the fuel cell and defining a cavity between the cell retainer, the fuel cell, and the plate. The fuel cell cassette also includes a seal disposed within the cavity for sealing the edge of the fuel cell. The seal is compliant at operational temperatures of the fuel cell, thereby allowing lateral expansion and contraction of the fuel cell within the cavity while maintaining sealing at the edge of the fuel cell.

  18. Failure of Magnetic Fluid Seals Operating in Water: Preliminary Conclusions

    Directory of Open Access Journals (Sweden)

    Matuszewski Leszek

    2017-06-01

    Full Text Available The article analyses properties of magnetic fluid seals installed in rotary sealing nodes which operate in the utility water environment. Seals of this type have been examined as a possible solution to the problem with ship manoeuvring propulsion sealing. The present analysis bases on laboratory durability tests of magnetic fluid seals exposed to longterm utility water loads, at different water pressures and shaft revolutions. The basic seal durability criterion was the number of revolutions made by the sealing node shaft until the appearance of water tightness loss (leakage. It was found that the main factor leading to the wear of the seal is the relative speed of the magnetic fluid with respect to that of the utility water, and this process is heavily affected by the pressure acting on the seal. The reported test results are presented in the form of diagrams showing the seal durability (time until water tightness loss as a function of rotational speed. The curves shown in the diagrams are regular, with two different rotational speed ranges: the highspeed range, when the tightness loss is relatively fast, and the low-speed range, with a clear tendency to prolong the seal lifetime. These diagrams were given the name of durability curves of the MF seal operating in water. The results of the performed tests suggest formal similarity between the experimental data distribution concerning tightness loss processes occurring in magnetic fluid seals operating in water environment and metal fatigue processes. The article proposes a preliminary simplified durability model to describe the examined phenomenon.

  19. Experimental investigation on flow and heat transfer for cooling flush-mounted ribbons in a channel: Application of an EHD active enhancement method

    OpenAIRE

    Alami Nia Amin; Campo Antonio

    2016-01-01

    In the present study, the heat transfer enhancement of a bundle of flush-mounted ribbons placed on the floor of a rectangular duct was investigated experimentally. The flush-mounted ribbons act as heat sources and the cooling happens with air. The air flow was two-dimensional, steady, viscous and incompressible under either laminar (500 ≤ ReDh < 2000) and turbulent (2000 ≤ Re Dh ≤ 4500) conditions. The hydrodynamics and heat transfer behavior of the air flo...

  20. Small Scales Structure of MHD Turbulence, Tubes or Ribbons?

    Science.gov (United States)

    Verdini, A.; Grappin, R.; Alexandrova, O.; Lion, S.

    2017-12-01

    Observations in the solar wind indicate that turbulent eddies change their anisotropy with scales [1]. At large scales eddies are elongated in direction perpendicular to the mean-field axis. This is the result of solar wind expansion that affects both the anisotropy and single-spacecraft measurments [2,3]. At small scales one recovers the anisotropy expected in strong MHD turbulence and constrained by the so-called critical balance: eddies are elongated along the mean-field axis. However, the actual eddy shape is intermediate between tubes and ribbons, preventing us to discriminate between two concurrent theories that predict 2D axysimmetric anisotropy [4] or full 3D anisotropy [5]. We analyse 10 years of WIND data and apply a numerically-derived criterion to select intervals in which solar wind expansion is expected to be negligible. By computing the anisotropy of structure functions with respect to the local mean field we obtain for the first time scaling relations that are in agreement with full 3D anisotropy, i.e. ribbons-like structures. However, we cannot obtain the expected scaling relations for the alignment angle which, according to the theory, is physically responsible for the departure from axisymmetry. In addition, a further change of anisotropy occurs well above the proton scales. We discuss the implication of our findings and how numerical simulations can help interpreting the observed spectral anisotropy. [1] Chen et al., ApJ, 768:120, 2012 [2] Verdini & Grappin, ApJL, 808:L34, 2015 [3] Vech & Chen, ApJL, 832:L16, 2016 [4] Goldreich & Shridar, ApJ, 438:763, 1995 [5] Boldyrev, ApJL, 626:L37, 2005

  1. Long-term sealing of openings in salt formations

    International Nuclear Information System (INIS)

    Walter, F.; Stockmann, N.; Yaramanci, U.; Laurens, J.F.

    1993-01-01

    Radioactive wastes can be disposed of in deep salt formations. Rock salt is a suitable geologic medium because of its unique characteristics. Open boreholes, shafts and drifts are created to provide physical access to the repository. Long-term seals must be emplaced in those potential pathways to prevent radioactive release to the biosphere. The sealing materials must be mechanically and, most important, geochemically stable within the host rock. Salt bricks made of compressed salt-powder are understood to be the first choice long-term sealing material. Seals built from salt bricks will be ductile. The permeability of the salt bricks is assumed to be in the order of 2*10 -15 m 2 . Large sealing systems are built by combining the individual bricks with mortar. Raw materials for mortar are fine-grained halite powder and ground saliferous clay. The permeability of the mortar decreases with its salt content to approx. 2*10 -14 m 2 . Moistened saliferous clay may show temporary swelling. Sealing experiments will be carried out in the Asse salt mine. Long-term seals will be built into holes of 1 m diameter. The contact and merging of the brick-wall with the surrounding rock salt will be investigated in long-term tests. Within the in situ sealing program a number of geophysical methods are applied. Acoustic emission measurements are used to study the effects of high pressure gas injection and a geoelectrical observation program is aiming to estimate the permeability in and around the long-term seal. High frequency electromagnetic methods contribute to the knowledge of the petrophysical rock properties. 11 refs., 12 figs

  2. Technological progress in sealed lead/acid batteries

    Science.gov (United States)

    Yamashita, J.; Nakashima, H.; Kasai, Y.

    A brief review is given of the history of the research and development of sealed lead/acid batteries during the 30 years since, in 1959, the Yuasa Battery Co. introduced a small-sized sealed battery as the power supply for portable television sets. In 1965, Yuasa began the full-scale mass production and sale of a small-sized sealed lead/acid battery under the NOYPER brand. In 1970, the use of a PbCa alloy grid was adopted, and there followed the successful development of a sealed battery with an oxygen-recombination facility. In 1976, Yuasa more or less established the basic technology for the valve-regulated sealed lead/acid battery — the NP battery — which is now the type in general use. Throughout the 1980s, Yuasa, has continued development in order to expand the sphere of application for the production technology of valve-regulated batteries for motorcycles, as well as for stationary duties with large capacities of 100 to 3000 A h. Recently, in order to improve the reliability and boost the output of sealed lead/acid batteries for employment in UPS power sources, Yuasa has been working intently on the design of a valve-regulated lead/acid battery with outstanding characteristics for high-rate discharge and resistance to high temperatures.

  3. Sealing a Loosely Fitting Valve Assembly

    Science.gov (United States)

    Goff, L.; Tellier, G.

    1986-01-01

    Double-ring seal avoids expense of remachining or redesigning valve parts. Mating fittings on valve sealed by pair of rings - one O-ring and backup ring. Backup ring fills relatively large gap between parts. Prevents softer O-ring from being pushed into and through gap.

  4. Critical Height of the Torus Instability in Two-ribbon Solar Flares

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dong; Liu, Rui; Wang, Yuming; Liu, Kai; Chen, Jun; Liu, Jiajia; Zhou, Zhenjun [CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhang, Min, E-mail: rliu@ustc.edu.cn [Department of Mathematics and Physics, Anhui Jianzhu University, Hefei 230601 (China)

    2017-07-01

    We studied the background field for 60 two-ribbon flares of M-and-above classes during 2011–2015. These flares are categorized into two groups, i.e., eruptive and confined flares, based on whether a flare is associated with a coronal mass ejection or not. The background field of source active regions is approximated by a potential field extrapolated from the B {sub z} component of vector magnetograms provided by the Helioseismic and Magnetic Imager. We calculated the decay index n of the background field above the flaring polarity inversion line, and defined a critical height h {sub crit} corresponding to the theoretical threshold ( n {sub crit} = 1.5) of the torus instability. We found that h {sub crit} is approximately half of the distance between the centroids of opposite polarities in active regions and that the distribution of h {sub crit} is bimodal: it is significantly higher for confined flares than for eruptive ones. The decay index increases monotonously with increasing height for 86% (84%) of the eruptive (confined) flares but displays a saddle-like profile for the rest, 14% (16%), which are found exclusively in active regions of multipolar field configuration. Moreover, n at the saddle bottom is significantly smaller in confined flares than that in eruptive ones. These results highlight the critical role of background field in regulating the eruptive behavior of two-ribbon flares.

  5. Electromagnetic shaft seal

    International Nuclear Information System (INIS)

    Takahashi, Kenji.

    1994-01-01

    As an electromagnetic shaft seal, there are disposed outwarding electromagnetic induction devices having generating power directing to an electroconductive fluid as an object of sealing, and inwarding electromagnetic induction device added coaxially. There are disposed elongate rectangular looped first coils having a predetermined inner diameter, second coils having the same shape and shifted by a predetermined pitch relative to the first coil and third coil having the same shape and shifted by a predetermined pitch relative to the second coil respectively each at a predetermined inner diameter of clearance to the outwarding electromagnetic induction devices and the inwarding electromagnetic induction device. If the inwarding electromagnetic induction device and the outwarding electromagnetic induction device are operated, they are stopped at a point that the generating power of the former is equal with the sum of the generating power of the latter and a differential pressure. When three-phase AC is charged to the first coil, the second coil and the third coil successively, a force is generated in the advancing direction of the magnetic field in the electroconductive fluid by the similar effect to that of a linear motor, and the seal is maintained at high reliability. Moreover, the limit for the rotational angle of the shaft is not caused. (N.H.)

  6. Enclosed mechanical seal face design for brittle materials copyright

    International Nuclear Information System (INIS)

    Marsi, J.A.

    1994-01-01

    Metal carbides are widely used as seal face material due to their hardness and wear resistance. Silicon carbide (SiC) has excellent performance as a seal face material, but it is relatively brittle and may break due to accidental overloads outside the boundary of normal operating conditions. In mechanical seals for nuclear primary coolant pumps, the shattered SiC pieces can get into the reactor system and cause serious damage. The conventional method of containing an SiC seal face is to shrink-fit it in a holder, which may lead the seal designer to contend with unwanted seal face deflections. This paper presents a successful, tested design which does not rely on shrink-fits. 5 refs., 9 figs., 4 tabs

  7. High-Pressure Hot-Gas Self-Acting Floating Ring Shaft Seal for Liquid Rocket Turbopumps. [tapered bore seals

    Science.gov (United States)

    Burcham, R. E.; Diamond, W. A.

    1980-01-01

    Design analysis, detail design, fabrication, and experimental evaluation was performed on two self acting floating ring shaft seals for a rocket engine turbopump high pressure 24132500 n/sq m (3500 psig) hot gas 533 K 9500 F) high speed 3142 rad/sec (30000 rmp) turbine. The initial design used Rayleigh step hydrodynamic lift pads to assist in centering the seal ring with minimum rubbing contact. The final design used a convergent tapered bore to provide hydrostatic centering force. The Rayleigh step design was tested for 107 starts and 4.52 hours total. The leakage was satisfactory; however, the design was not acceptable due to excessive wear caused by inadequate centering force and failure of the sealing dam caused by erosion damage. The tapered bore design was tested for 370 starts and 15.93 hours total. Satisfactory performance for the required life of 7.5 hours per seal was successfully demonstrated.

  8. Fluid moderator control system fuel assembly seal connector

    International Nuclear Information System (INIS)

    Veronesi, L.; Tower, S.N.; Klassen, W.E.

    1987-01-01

    A nuclear reactor is described comprising fuel assemblies having one or more flow channels therethrough, a core support plate having one or more flow channels therethrough, and seal connectors for sealingly connecting the one or more flow channels in the core support plate with the one or more flow channels in the fuel assemblies. The seal connectors each comprises a first portion and second portion each comprising an elongated member having a flow channel therethrough and being in substantial axial alignment with each other and being separated by a space therebetween, means for sealingly connecting the first portion o one or the one or more flow channels in the fuel assemblies, means for sealingly connecting the second portion to the first portion and for allowing relative motion between the portions, means for limiting the relative motion of the first and second portion in directions toward and away from each other, means for reconnectingly connecting and resealingly sealing the second portion to one of the one or more flow channels in the core support plate. It comprises a slip fit connection whereby the remote end of the second portion fits within whereby the remote end of the second portion fits within an opening in the core support plate which is in flow communication with the one or more flow channels in the core support plate and further comprises a ball and cones seal in series with axially spaced ring seals

  9. A Study on Sealing Process of Anodized Al Alloy Film

    Science.gov (United States)

    Tsujita, Takeshi; Sato, Hiroshi; Tsukahara, Sonoko; Ishikawa, Yuuichi

    Since sealing is an important process to improve the corrosion resistance in practical application of anodized aluminum, we prepared anodic oxide films on A5052 alloy in an oxalic acid bath and a sulfuric acid bath, sealed them at various conditions, and analyzed them by scanning electron microscopy, acid-dissolution examination, admittance measurements and infrared spectroscopy. The pore radius of the oxalic acid anodized film was about 5 times larger than that of sulfuric acid anodized film, while the corrosion resistance of the former showed about 2 times higher value than the latter with the same sealed state and amount of hydroxide formed by sealing process of the former was 6 times larger than the latter, respectively. Steam sealing formed dense hydroxide and boiling water sealing formed big coral-like hydroxide, whereas the corrosion resistance of the film sealed by the former showed about 1.5 times higher value than that sealed by the latter, respectively. Thus microstructure of anodic oxide films and their surface morphology after sealing process clearly depended on their anodizing solution and the sealing condition and showed obvious relation to electric and corrosive properties.

  10. The symplectic fermion ribbon quasi-Hopf algebra and the SL(2,Z)-action on its centre

    Energy Technology Data Exchange (ETDEWEB)

    Farsad, Vanda

    2017-06-14

    This thesis is concerned with ''N pairs of symplectic fermions'' which are examples of logarithmic conformal field theories in two dimensions. The mathematical language of two-dimensional conformal field theories (on Riemannian surfaces of genus zero) are vertex operator algebras. The representation category of the even part of the symplectic fermion vertex operator super-algebra Rep V{sub ev} is conjecturally a factorisable finite ribbon tensor category. This determines an isomorphism of projective representations between two SL(2,Z)-actions associated to V{sub ev}. The first action is obtained by modular transformations on the space of so-called pseudo-trace functions of a vertex operator algebra. For V{sub ev} this was developed by A.M.Gaberdiel and I. Runkel. For the action one uses that Rep V{sub ev} is conjecturally a factorisable finite ribbon tensor category and thus carries a projective SL(2,Z)-action on a certain Hom-space [Ly1,Ly2,KL]. To do so we calculate the SL(2,Z)-action on the representation category of a general factorisable quasi-Hopf algebras. Then we show that Rep V{sub ev} is conjecturally ribbon equivalent to Rep Q, for Q a factorisable quasi-Hopf algebra, and calculate the SL(2,Z)-action explicitly on Rep Q. The result is that the two SL(2,Z)-action indeed agree. This poses the first example of such comparison for logarithmic conformal field theories.

  11. Shaft seal assembly for high speed and high pressure applications

    Science.gov (United States)

    Hadt, W. F.; Ludwig, L. P. (Inventor)

    1979-01-01

    A seal assembly is provided for reducing the escape of fluids from between a housing and a shaft rotably mounted in the housing. The seal assembly comprises a pair of seal rings resiliently connected to each other and disposed in side-by-side relationship. In each seal ring, both the internal bore surface and the radial face which faces away from the other seal ring are provided with a plurality of equi-spaced recesses. The seal faces referred to are located adjacent a seating surface of the housing. Under normal operating conditions, the seal assembly is stationary with respect to the housing, and the recesses generate life, keep the assembly spaced from the rotating shaft and allow slip therebetween. The seal assembly can seize on the shaft, and slip will then occur between the radial faces and the housing.

  12. Improvement in oil seal performance of gas compressor in HTTR

    International Nuclear Information System (INIS)

    Oyama, Sunao; Hamamoto, Shimpei; Nemoto, Takahiro; Sekita, Kenji; Isozaki, Minoru; Emori, Kouichi; Ohta, Yukimaru; Mizushima, Toshihiko; Kaneshiro, Noriyuki; Ito, Yoshiteru; Yamamoto, Hideo

    2007-08-01

    High-Temperature engineering Test Reactor (HTTR) built by Japan Atomic Energy Agency (JAEA) has reciprocating compressor commonly used to extract and discharge helium gas into primary/secondary coolant helium loop from helium purification system. Piston rod seal of the compressor consist of several components to prevent coolant leak. However, rod seal system has weak reliability during long term operation due to repeated leakage of seal oil in operation. As a result of investigations, leakage's root is found in that seal were used in a range beyond limit sliding properties of seal material. For this reason, a lip of the seal was worn and transformed itself and was not able to sustain a seal function. Therefore, through tests using facility actual equipment for endurance of candidate materials, one seal material were chosen for long term operation. (author)

  13. Application of a magnetic fluid seal to rotary blood pumps

    International Nuclear Information System (INIS)

    Mitamura, Y; Arioka, S; Azegami, M; Sakota, D; Sekine, K

    2008-01-01

    A magnetic fluid seal enables mechanical contact-free rotation of a shaft without frictional heat and material wear and hence has excellent durability. However, the durability of a magnetic fluid seal decreases in liquid. The life of a seal applied to a rotary blood pump is not known. We have developed a magnetic fluid seal that has a shield mechanism minimizing the influence of the rotary pump on the magnetic fluid. The developed magnetic fluid seal worked for over 286 days in a continuous flow condition, for 24 days (on-going) in a pulsatile flow condition and for 24 h (electively terminated) in blood flow. The magnetic fluid seal is promising as a shaft seal for rotary blood pumps

  14. VACOSS - variable coding seal system for nuclear material control

    International Nuclear Information System (INIS)

    Kennepohl, K.; Stein, G.

    1977-12-01

    VACOSS - Variable Coding Seal System - is intended to seal: rooms and containers with nuclear material, nuclear instrumentation and equipment of the operator, instrumentation and equipment at the supervisory authority. It is easy to handle, reusable, transportable and consists of three components: 1. Seal. The light guide in fibre optics with infrared light emitter and receiver serves as lead. The statistical treatment of coded data given in the seal via adapter box guarantees an extremely high degree of access reliability. It is possible to store the data of two undue seal openings together with data concerning time and duration of the opening. 2. The adapter box can be used for input or input and output of data indicating the seal integrity. 3. The simulation programme is located in the computing center of the supervisory authority and permits to determine date and time of opening by decoding the seal memory data. (orig./WB) [de

  15. Test of Seal System for Flexible Pipe End Fitting

    DEFF Research Database (Denmark)

    Banke, Lars; Jensen, Thomas Gregers

    1999-01-01

    The purpose of the end fitting seal system is to ensure leak proof termination of flexible pipes. The seal system of an NKT end fitting normally consists of a number of ring joint gaskets mounted in a steel sleeve on the outside of the polymeric inner liner of the pipe. The seal system is activated...... by compression of the gaskets, thus using the geometry to establish a seal towards the inner liner of the pipe and the steel sleeve of the end fitting. This paper describes how the seal system of an end fitting can be tested using an autoclave. By regulating temperature and pressure, the seal system can...... be tested up to 130oC and 51.7 MPa. Pressure, temperature and the mechanical behaviours of the pipe are measured for use in further research. The set-up is used to test the efficiency of the seal system as function of parameters such as cross sectional shapes of the gaskets, tolerances between gaskets...

  16. Stirling engine or heat pump having an improved seal

    Science.gov (United States)

    White, Maurice A.; Riggle, Peter; Emigh, Stuart G.

    1985-01-01

    A Stirling Engine or Heat Pump having two relatively movable machine elements for power transmission purposes includes a hermetic seal bellows interposed between the elements for separating a working gas from a pressure compensating liquid that balances pressure across the bellows to reduce bellows stress and to assure long bellows life. The volume of pressure compensating liquid displaced due to relative movement between the machine elements is minimized by enclosing the compensating liquid within a region exposed to portions of both machine elements at one axial end of a slidable interface presented between them by a clearance seal having an effective diameter of the seal bellows. Pressure equalization across the bellows is achieved by a separate hermetically sealed compensator including a movable enclosed bellows. The interior of the compensator bellows is in communication with one side of the seal bellows, and its exterior is in communication with the remaining side of the seal bellows. A buffer gas or additional liquid region can be provided at the remaining axial end of the clearnace seal, along with valved arrangements for makeup of liquid leakage through the clearance seal.

  17. Effect of precipitation on the shape memory effect of Ti50Ni25Cu25 melt-spun ribbon

    International Nuclear Information System (INIS)

    Tong Yunxiang; Liu Yong; Xie Zeliang; Zarinejad, Mehrdad

    2008-01-01

    The present research aims to provide accurate understanding of the relation between precipitation (volume fraction, morphology, type) and shape memory effect of Ti 50 Ni 25 Cu 25 melt-spun ribbon. Rapid thermal annealing was used to control the microstructural development while the shape memory effect of the ribbon was determined under constraint thermal cycling. The results show that the precipitation process takes the following sequence: B11 TiCu → B11 TiCu + Ti 2 (Ni, Cu) → Ti 2 (Ni, Cu) with increasing annealing temperature or duration. The shape memory effect is found to depend on both the volume fraction and the distribution of the precipitates. The former affects the shape recovery strain through reduction of the transformation volume participating the shape recovery. The latter affects the shape recovery strain through strengthening the matrix thus reducing the martensite strain which is more predominant under low constraint stresses. Precipitation strengthening, on the other hand, reduces the tendency of dislocation generation/movement, thus reducing the irreversible strain and improving shape recovery strain. This understanding provides guidelines on the optimization of the shape memory properties of the Ti 50 Ni 25 Cu 25 melt-spun ribbon via post-processing annealing

  18. Synthesis and magnetic properties of a new borophosphate SrCo2BPO7 with a four-column ribbon structure.

    Science.gov (United States)

    Gou, Wenbin; He, Zhangzhen; Yang, Ming; Zhang, Weilong; Cheng, Wendan

    2013-03-04

    A new borophosphate SrCo2BPO7 is synthesized by a conventional high-temperature solid-state reaction. The titled compound is found to crystallize in monoclinic system with space group P21/c, which displays a distorted four-column ribbon structure. Both BO3 triangles and PO4 tetrahedra are isolated, while irregular triangles built by Co(2+) ions are found to exist between the connecting ribbons. Magnetic behaviors are investigated by means of susceptibility, magnetization, and heat capacity measurements. The results confirm that SrCo2BPO7 possesses a three-dimensional antiferromagnetic ordering at 25 K. The possible spin arrangements in the system are also suggested.

  19. Performance assessment of sealing systems. Conceptual and integrated modelling of plugs and seals

    Energy Technology Data Exchange (ETDEWEB)

    Ruebel, Andre; Buhmann, Dieter; Kindlein, Jonathan; Lauke, Thomas

    2016-08-15

    The long-time isolation of radionuclides from the biosphere is the goal of the storage of radioactive waste in deep geological repositories. For repositories in rock salt, this goal is achieved on the one hand by the impermeable undisturbed part of the salt host rock formation and on the other hand by crushed salt, which is used to backfill the mine openings in the emplacement areas and galleries created during the construction of the repository. The crushed salt backfill is compacted over time and achieves a sufficiently high hydraulic resistance to avoid inflow of brines into the emplacement areas of the repository in the long-term. Plugs and seals must additionally provide their sealing function during the early post closure phase, until the compaction of the backfill is adequate and the permeability of the backfill is sufficiently low. To assess the future development of the waste repository, an adequate knowledge of the material behaviour is necessary and related mathematical models must be developed to be able to perform predictions on the long-term safety of the repository. An integrated performance assessment model was formulated that describes the long-term behaviour of a sealing built from salt concrete. The average permeability of the sealing changes with time after its emplacement from various processes of which two were regarded in a constitutive model: first, the healing of the EDZ in the host rock around the sealing, and second, the corrosion of the salt concrete material resulting from brine attack. Empirical parameter model functions were defined for both processes to reflect the actual behaviour. The mathematical model was implemented in the integrated performance assessment model LOPOS which is used by GRS as near-field model for repositories in salt. Deterministic and probabilistic calculations were performed with realistic parameters showing how the permeability of the sealing decreases during the first 2 000 years due to the healing of the EDZ

  20. Performance assessment of sealing systems. Conceptual and integrated modelling of plugs and seals

    International Nuclear Information System (INIS)

    Ruebel, Andre; Buhmann, Dieter; Kindlein, Jonathan; Lauke, Thomas

    2016-08-01

    The long-time isolation of radionuclides from the biosphere is the goal of the storage of radioactive waste in deep geological repositories. For repositories in rock salt, this goal is achieved on the one hand by the impermeable undisturbed part of the salt host rock formation and on the other hand by crushed salt, which is used to backfill the mine openings in the emplacement areas and galleries created during the construction of the repository. The crushed salt backfill is compacted over time and achieves a sufficiently high hydraulic resistance to avoid inflow of brines into the emplacement areas of the repository in the long-term. Plugs and seals must additionally provide their sealing function during the early post closure phase, until the compaction of the backfill is adequate and the permeability of the backfill is sufficiently low. To assess the future development of the waste repository, an adequate knowledge of the material behaviour is necessary and related mathematical models must be developed to be able to perform predictions on the long-term safety of the repository. An integrated performance assessment model was formulated that describes the long-term behaviour of a sealing built from salt concrete. The average permeability of the sealing changes with time after its emplacement from various processes of which two were regarded in a constitutive model: first, the healing of the EDZ in the host rock around the sealing, and second, the corrosion of the salt concrete material resulting from brine attack. Empirical parameter model functions were defined for both processes to reflect the actual behaviour. The mathematical model was implemented in the integrated performance assessment model LOPOS which is used by GRS as near-field model for repositories in salt. Deterministic and probabilistic calculations were performed with realistic parameters showing how the permeability of the sealing decreases during the first 2 000 years due to the healing of the EDZ

  1. Materials for water pump mechanical seals

    International Nuclear Information System (INIS)

    Brousse, P.

    1992-01-01

    In view of the continually increasing power ratings of conventional and nuclear power plants and the related reliability and safety problems, plant builders have had to develop seal systems compatible with current water pump performances. In 1970, EDF/R and DD was already concerned by this problem. It soon became obvious that the nature of the materials used for the friction surfaces was decisive for seal durability. Exceptional loads (transients, high vibration levels, etc...) hasten aging. To begin with, friction surfaces consisted of a hard material (tungsten carbide) mated with a soft material (carbon). Resistance was unpredictable and not compatible with industrial requirements. Tests performed on the EDF/R and DD test benches evidenced the same types of degradation. The mechanical seal manufacturers then began to use ceramic materials (silicon carbide), which raised high expectations. Unfortunately, these were recent materials and their manufacturing process was not thoroughly understood. Hopes were soon dashed in many applications, including that of mechanical seals. Fluctuating results were obtained over the next few years. The raw material suppliers made progress, especially with regard to reducing fragility. On a parallel, the mechanical seal manufacturers initiated comparative tests on the friction resistance of materials. It has also been established that ceramics have to be stringently supervised at all levels: part design, inspection, assembly, use. EDF has much insisted that mechanical seal suppliers guarantee the constant quality of their products. EDF/R and DD has systematically tested new sensitive devices, under normal and exceptional conditions, prior to their installation at the plants. At the present time, the silicon carbides proposed by the mechanical seal suppliers are entirely satisfactory. The carbon mating surface was far less problematic. The required reliability was obtained by replacing resin binder carbons by the more resistant

  2. 78 FR 29703 - Narrow Woven Ribbons With Woven Selvedge From Taiwan: Preliminary Results of Antidumping Duty...

    Science.gov (United States)

    2013-05-21

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-844] Narrow Woven Ribbons With... AGENCY: Import Administration, International Trade Administration, Department of Commerce. SUMMARY: The..., International Trade Administration, U.S. Department of Commerce, 14th Street and Constitution Avenue NW...

  3. The CANDU irradiated fuel safeguards sealing system at the threshold of implementation

    International Nuclear Information System (INIS)

    Stirling, A.J.; Kupca, S.; Martin, R.E.; West, R.J.; Aikens, A.E.; Cox, C.A.; White, B.F.; Smith, M.T.; Payne, W.E.

    1985-07-01

    The development of a safeguards containment and surveillance system for the irradiated fuel discharged from CANDU nuclear generating stations has inspired the development of three different sealing technologies. Each seal type utilizes a random seal identity of different design. The AECL Random Coil (ARC) Seal combines the identity and integrity elements in the ultrasonic signature of a wire coil. Two variants of an optical seal have been developed which features identity elements of crystalline zirconium and aluminum. The sealed cap-seal uses a conventional IAEA 'Type X Seal' (wire seal). The essential features and relative merits of each seal design are described

  4. Temporary fire sealing of penetrations on TFTR

    International Nuclear Information System (INIS)

    Hondorp, H.L.

    1981-02-01

    The radiation shielding provided for TFTR for D-D and D-T operation will be penetrated by numerous electrical and mechanical services. Eventually, these penetrations will have to be sealed to provide the required fire resistance, tritium sealability, pressure integrity and radiation attenuation. For the initial hydrogen operation, however, fire sealing of the penetrations in the walls and floor is the primary concern. This report provides a discussion of the required and desirable properties of a temporary seal which can be used to seal these penetrations for the hydrogen operation and then subsequently be removed and replaced as required for the D-D and D-T operations. Several candidate designs are discussed and evaluated and recommendations are made for specific applications

  5. Wafer-level packaging with compression-controlled seal ring bonding

    Science.gov (United States)

    Farino, Anthony J

    2013-11-05

    A device may be provided in a sealed package by aligning a seal ring provided on a first surface of a first semiconductor wafer in opposing relationship with a seal ring that is provided on a second surface of a second semiconductor wafer and surrounds a portion of the second wafer that contains the device. Forcible movement of the first and second wafer surfaces toward one another compresses the first and second seal rings against one another. A physical barrier against the movement, other than the first and second seal rings, is provided between the first and second wafer surfaces.

  6. O-Ring sealing arrangements for ultra-high vacuum systems

    Science.gov (United States)

    Kim, Chang-Kyo; Flaherty, Robert

    1981-01-01

    An all metal reusable O-ring sealing arrangement for sealing two concentric tubes in an ultra-high vacuum system. An O-ring of a heat recoverable alloy such as Nitinol is concentrically positioned between protruding sealing rings of the concentric tubes. The O-ring is installed between the tubes while in a stressed martensitic state and is made to undergo a thermally induced transformation to an austenitic state. During the transformation the O-ring expands outwardly and contracts inwardly toward a previously sized austenitic configuration, thereby sealing against the protruding sealing rings of the concentric tubes.

  7. Bentonite as a waste isolation pilot plant shaft sealing material

    International Nuclear Information System (INIS)

    Daemen, J.; Ran, Chongwei

    1996-12-01

    Current designs of the shaft sealing system for the Waste Isolation Pilot Plant (WIPP) propose using bentonite as a primary sealing component. The shaft sealing designs anticipate that compacted bentonite sealing components can perform through the 10,000-year regulatory period and beyond. To evaluate the acceptability of bentonite as a sealing material for the WIPP, this report identifies references that deal with the properties and characteristics of bentonite that may affect its behavior in the WIPP environment. This report reviews published studies that discuss using bentonite as sealing material for nuclear waste disposal, environmental restoration, toxic and chemical waste disposal, landfill liners, and applications in the petroleum industry. This report identifies the physical and chemical properties, stability and seal construction technologies of bentonite seals in shafts, especially in a saline brine environment. This report focuses on permeability, swelling pressure, strength, stiffness, longevity, and densification properties of bentonites

  8. Bentonite as a waste isolation pilot plant shaft sealing material

    Energy Technology Data Exchange (ETDEWEB)

    Daemen, J.; Ran, Chongwei [Univ. of Nevada, Reno, NV (United States)

    1996-12-01

    Current designs of the shaft sealing system for the Waste Isolation Pilot Plant (WIPP) propose using bentonite as a primary sealing component. The shaft sealing designs anticipate that compacted bentonite sealing components can perform through the 10,000-year regulatory period and beyond. To evaluate the acceptability of bentonite as a sealing material for the WIPP, this report identifies references that deal with the properties and characteristics of bentonite that may affect its behavior in the WIPP environment. This report reviews published studies that discuss using bentonite as sealing material for nuclear waste disposal, environmental restoration, toxic and chemical waste disposal, landfill liners, and applications in the petroleum industry. This report identifies the physical and chemical properties, stability and seal construction technologies of bentonite seals in shafts, especially in a saline brine environment. This report focuses on permeability, swelling pressure, strength, stiffness, longevity, and densification properties of bentonites.

  9. Magnetic nanofluids and magnetic composite fluids in rotating seal systems

    International Nuclear Information System (INIS)

    Borbath, T; Borbath, I; Boros, T; Bica, D; Vekas, L; Potencz, I

    2010-01-01

    Recent results are presented concerning the development of magnetofluidic leakage-free rotating seals for vacuum and high pressure gases, evidencing significant advantages compared to mechanical seals. The micro-pilot scale production of various types of magnetizable sealing fluids is shortly reviewed, in particular the main steps of the chemical synthesis of magnetic nanofluids and magnetic composite fluids with light hydrocarbon, mineral oil and synthetic oil carrier liquids. The behavior of different types of magnetizable fluids in the rotating sealing systems is analyzed. Design concepts, some constructive details and testing procedures of magnetofluidic rotating seals are presented such as the testing equipment. The main characteristics of several magnetofluidic sealing systems and their applications will be presented: vacuum deposition systems and liquefied gas pumps applications, mechanical and magnetic nanofluid combined seals, gas valves up to 40 bar equipped by rotating seal with magnetic nanofluids and magnetic composite fluids.

  10. Sensitivity analysis overlaps of friction elements in cartridge seals

    Directory of Open Access Journals (Sweden)

    Žmindák Milan

    2018-01-01

    Full Text Available Cartridge seals are self-contained units consisting of a shaft sleeve, seals, and gland plate. The applications of mechanical seals are numerous. The most common example of application is in bearing production for automobile industry. This paper deals with the sensitivity analysis of overlaps friction elements in cartridge seal and their influence on the friction torque sealing and compressive force. Furthermore, it describes materials for the manufacture of sealings, approaches usually used to solution of hyperelastic materials by FEM and short introduction into the topic wheel bearings. The practical part contains one of the approach for measurement friction torque, which results were used to specifying the methodology and precision of FEM calculation realized by software ANSYS WORKBENCH. This part also contains the sensitivity analysis of overlaps friction elements.

  11. Comment on 'Quantum string seal is insecure'

    International Nuclear Information System (INIS)

    He Guangping

    2007-01-01

    An attack strategy was recently proposed by Chau [Phys. Rev. A 75, 012327 (2007)], which was claimed to be able to break all quantum string seal protocols. Here it will be shown that the attack cannot obtain nontrivial information and escape the detection simultaneously in a class of quantum string seal, including the one proposed by He [Int. J. Quantum Inf. 4, 677 (2006)]. Thus it is insufficient to conclude that all quantum string seals are insecure

  12. A seal analyzer for testing container integrity

    International Nuclear Information System (INIS)

    McDaniel, P.; Jenkins, C.

    1988-01-01

    This paper reports on the development of laboratory and production seal analyzer that offers a rapid, nondestructive method of assuring the seal integrity of virtually any type of single or double sealed container. The system can test a broad range of metal cans, drums and trays, membrane-lidded vessels, flexible pouches, aerosol containers, and glass or metal containers with twist-top lids that are used in the chemical/pesticide (hazardous materials/waste), beverage, food, medical and pharmaceutical industries

  13. HMSRP Hawaiian Monk Seal Telemetry Tag Deployments

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project investigates foraging behavior of Hawaiian monk seals by conducting telemetry studies. During these studies, live seals are instrumented with dive...

  14. HMSRP Hawaiian Monk Seal Argos Location Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project investigates foraging behavior of Hawaiian monk seals by conducting telemetry studies. During these studies, live seals are instrumented with satellite...

  15. EXPERIMENTAL STUDY OF MAGNETIC FLUID SEAL

    Directory of Open Access Journals (Sweden)

    V. G. Bashtovoi

    2006-01-01

    Full Text Available Dependences of critical pressure drop, being held by magnetic fluid seal, on time in a static state and shaft rotation velocity in dynamics have been experimentally determined. The significant influence of particles’ redistribution in magnetic fluid on static parameters of magnetic fluid seal has been established.

  16. Straight cylindrical seal for high-performance turbomachines

    Science.gov (United States)

    Hendricks, Robert C.

    1987-01-01

    A straight cylindrical seal configuration representing the seal for a high-performance turbopump (e.g., the space shuttle main engine fuel pump) was tested under static (nonrotating) conditions. The test data included critical mass flux and pressure profiles over a wide range of inlet temperatures and pressures for fluid nitrogen and fluid hydrogen with the seal in concentric and fully eccentric positions. The critical mass fluxes (or leakage rates) for the concentric and fully eccentric configurations were nearly the same when based on stagnation conditions upstream of the seal. The fully eccentric configuration pressure profiles of the gas and liquid were different. Further, the pressure differences between the maximum and the minimum clearance positions were highly dependent on the geometric conditions, the temperature, and the absolute pressure at both the inlet and the exit. The pressure differences were greatest in the inlet region. The results, although complex, tend to follow the corresponding-states principles for critical flows. Gaseous injection near the seal exit plane significantly altered the pressure profiles and could be used to control turbomachine instabilities.

  17. Automated Image Acquisition System for the Verification of Copper-Brass Seal Images

    International Nuclear Information System (INIS)

    Stringa, E.; Bergonzi, C.; Littmann, F.; ); Marszalek, Y.; Tempesta, S.; )

    2015-01-01

    This paper describes a system for the verification of copper-brass seals realized by JRC according to DG ENER requirements. DG ENER processes about 20,000 metal seals per year. The verification of metal seals consists in visually checking the identity of a removed seal. The identity of a copper-brass seal is defined by a random stain pattern realized by the seal producer together with random scratches engraved when the seals are initialized ('seal production'). In order to verify that the seal returned from the field is the expected one its pattern is compared with an image taken during seal production. Formerly, seal initialization and verification were very heavy tasks as seal pictures were acquired with a camera one by one both in the initialization and verification stages. During the initialization the Nuclear Safeguards technicians had to place one by one new seals under a camera and acquire the related reference images. During the verification, the technician had to take used seals and place them one by one under a camera to take new pictures. The new images were presented to the technicians without any preprocessing and the technicians had to recognize the seal. The new station described in this paper has an automated image acquisition system allowing to easily process seals in batches of 100 seals. To simplify the verification, a software automatically centres and rotates the newly acquired seal image in order to perfectly overlap with the reference image acquired during the production phase. The new system significantly speeds up seal production and helps particularly with the demanding task of seal verification. As a large part of the seals is dealt with by a joint Euratom-IAEA team, the IAEA directly profits from this development. The new tool has been in routine use since mid 2013. (author)

  18. MWTF jumper connector integral seal block development and leak testing

    International Nuclear Information System (INIS)

    Ruff, E.S.; Jordan, S.R.

    1995-01-01

    In fiscal year 1993, tests of an o-ring/tetraseal retainer designed to replace a gasket-type seal used in PUREX-type process jumper connectors encouraged the design of an improved seal block. This new seal block combines several parts into one unitized component called an integral seal block. This report summarizes development and leak testing of the new integral seal block. The integral seal block uses a standard o-ring nested in a groove to accomplish leak tightness. This seal block eliminates the need to machine acme threads into the lower skirt casting and seal retainers, eliminates tolerance stack-up, reduces parts inventory, and eliminates an unnecessary leak path in the jumper connector assembly. This report also includes test data on various types of o-ring materials subjected to heat and pressure. Materials tested included Viton, Kalrez, and fluorosilicone, with some incidental data on teflon coated silicone o-rings. Test experience clearly demonstrates the need to test each seal material for temperature and pressure in its intended application. Some materials advertised as being open-quotes betterclose quotes at higher temperatures did not perform up to expectations. Inspection of the fluorosilicone and Kalrez seals after thermal testing indicates that they are much more susceptible to heat softening than Viton

  19. WIPP [Waste Isolation Pilot Plant] panel entryway seal: Numerical simulation of seal composite interaction for preliminary design evaluation

    International Nuclear Information System (INIS)

    Argueello, J.G.

    1988-04-01

    This report presents the results of a series of structural analyses performed to evaluate the structural interaction of the components of a potential two-component panel entryway seal configuration with each other and with the rock salt formation at the repository horizon of the Waste Isolation Pilot Plant. A two-dimensional axisymmetric geomechanical model is used to numerically simulate the interaction of the components of a 30.48 m (100 ft) long seal, consisting of concrete end caps and a crushed salt core, with each other and with the surrounding formation. Issues addressed in this report pertain to the consolidation of the crushed salt in terms of how much of the seal core reaches effective consolidation in the presence of the stiff concrete end caps since these could conceivably cause bridging (retardation of closure around the core) to occur. In addition, the stress field in the end caps is evaluated to determine if the concrete component maintains its integrity. The stresses induced in the surrounding formation are also evaluated to determine if the presence of the concrete component in the seal system results in a ''tightening'' of the formation around the seal. 20 refs., 43 figs., 2 tabs

  20. Electrical and microstructural characterization of silver sheathed high Tc superconductors wires and ribbons

    International Nuclear Information System (INIS)

    Chaffron, L.; Regnier, P.; Schmirgeld, L.; Maurice, F.; Aguillon, C.; Senoussi, S.

    1991-01-01

    High Tc superconductors wires and ribbons were prepared according to the powder in tube method. It is shown that the electrical performances of the so prepared superconductors can be considerably improved, first by increasing as much as possible the density of the green body before sintering, and afterwards by melt texturing the sintered conductors. Some measurements of the transport critical current density of our conductors as a function of their diameter or their thickness are then presented and compared with indirect values obtained via the Bean method. The highest transport Jc measured in the present study, before melt texturing, are: 2250 and 5100 A/cm 2 at 77 and 63 K respectively, for a 50 μm thick silver sheathed ribbon. These figures compare nicely with the values of the intergranular critical current densities determined from magnetic measurements which are: 2100 and 5000 A/cm 2 at the same temperatures, and 40000 A/cm 2 at 4.2 K. Much higher intergranular values, in the range of 10 5 A/cm 2 were obtained after melt texturing the wires. Finally, microstructural characterizations carried out by X-ray diffraction, electron microprobe analysis and transmission electron microscopy are reported and discussed