Science.gov

Sample records for adult weddell seals

  1. Bimodal Winter Haul-Out Patterns of Adult Weddell Seals (Leptonychotes weddellii) in the Southern Weddell Sea

    PubMed Central

    Fedak, Mike; Årthun, Marius; Nicholls, Keith; Robinson, Patrick; Costa, Dan; Biuw, Martin

    2016-01-01

    Hauling out is an essential component of pinniped life-history. Haul-out behaviour may be affected by biological (e.g. sex, age and condition) and physical factors (e.g. food availability and environmental conditions), and identifying these factors may help explain the spatio-temporal distribution and habitat use of pinnipeds. The aim of this study is to describe observed winter haul-out patterns of adult Weddell seals in the Weddell Sea and investigate the role of potential predictors to gain insight into the way these animals interact with the physical environment in this region. We examined the haul-out behaviour in relation to available biological (i.e., diving effort, sex) and physical information (i.e., sun angle). Thirty-three satellite telemetry tags were deployed on adult Weddell seals in the southern Weddell Sea during February 2007, 2009 and 2011, following their annual moult recording information on the behavioural mode of the animal: at surface, hauled out or diving. At the end of the austral summer Weddell seals spent, on average, more than 40% of their time hauled out on the ice. Under constant light conditions, it appears that physiological factors drive sex differences in the timing and duration of haul-out behaviour, with females spending on average more time hauled out than males during daylight hours. This time spent hauled-out declined to around 15% in both sexes by the beginning of autumn and remained at this level with a clear nocturnal haul-out pattern during the winter. The time spent diving increased during this period, indicating an increase in foraging effort during the winter months, and led to a common haul-out pattern in both sexes over winter. We found a positive relationship between haul-out duration and the percentage of time spent diving prior to a haul-out in both sexes, with the exception of female daytime haul-outs early in the year. PMID:27196097

  2. Health and condition in the adult Weddell seal of McMurdo Sound, Antarctica.

    PubMed

    Mellish, Jo-Ann E; Hindle, Allyson G; Horning, Markus

    2011-06-01

    Weddell seals (Leptonychotes weddellii) are large-bodied, long-lived mammals that live only in the circumpolar Antarctic. As such, they represent an ideal sentinel species for the impacts of environmental change on polar species. However, longitudinal physiological studies of marine mammals are notoriously difficult due to their largely aquatic lifestyle, such that many baseline indicators of health and condition are not well defined. Fifty known-age, adult seals (9-27 years, 24 males, 26 females) in McMurdo Sound were sampled for mass, total body fat, blubber depth and a suite of blood parameters (21 variables) to assess hydration state, nutritional plane, reproductive hormones (females only), organ function and immune status. Total body mass increased with age, whereas variation in blubber depth was best described by mass and/or sex, with an overall greater blubber thickness in female seals (p<0.001). Ten blood parameters showed a significant effect of one or more model variables, most prominently between the sexes. Serum chemistry suggested that females were better nourished and displayed lower indicators of acute stress compared to males. We noted limited age-related declines that might indicate impaired organ function. Overall, seals demonstrated clinically normal values for large mammals, even at the upper end of the age continuum. Future physiological studies in this species are strongly encouraged to incorporate potential sex effects in experimental design and analysis.

  3. Serum chemistry and antibodies against pathogens in antarctic fur seals, Weddell seals, crabeater seals, and Ross seals.

    PubMed

    Tryland, Morten; Nymo, Ingebjørg H; Nielsen, Ole; Nordøy, Erling S; Kovacs, Kit M; Krafft, Bjørn A; Thoresen, Stein I; Åsbakk, Kjetil; Osterrieder, Klaus; Roth, Swaantje J; Lydersen, Christian; Godfroid, Jacques; Blix, Arnoldus S

    2012-07-01

    Information on health parameters, such as antibody prevalences and serum chemistry that can reveal exposure to pathogens, disease, and abnormal physiologic conditions, is scarce for Antarctic seal species. Serum samples from Antarctic fur seals (Arctocephalus gazella, n=88) from Bouvetøya (2000-2001 and 2001-2002), and from Weddell seals (Leptonychotes weddellii, n=20), Ross seals (Ommatophoca rossii, n=20), and crabeater seals (Lobodon carcinophagus, n=9) from the pack-ice off Queen Maud Land, Antarctica (2001) were analyzed for enzyme activity, and concentrations of protein, metabolites, minerals, and cortisol. Adult Antarctic fur seal males had elevated levels of total protein (range 64-99 g/l) compared to adult females and pups (range 52-79 g/l). Antarctic fur seals had higher enzyme activities of creatine kinase, lactate dehydrogenase, and amylase, compared to Weddell, Ross, and crabeater seals. Antibodies against Brucella spp. were detected in Weddell seals (37%), Ross seals (5%), and crabeater seals (11%), but not in Antarctic fur seals. Antibodies against phocine herpesvirus 1 were detected in all species examined (Antarctic fur seals, 58%; Weddell seals, 100%; Ross seals, 15%; and crabeater seals, 44%). No antibodies against Trichinella spp., Toxoplasma, or phocine distemper virus (PDV) were detected (Antarctic fur seals were not tested for PDV antibodies). Antarctic seals are challenged by reduced sea ice and increasing temperatures due to climate change, and increased anthropogenic activity can introduce new pathogens to these vulnerable ecosystems and represent a threat for these animals. Our data provide a baseline for future monitoring of health parameters of these Antarctic seal species, for tracking the impact of environmental, climatic, and anthropogenic changes in Antarctica over time.

  4. Antarctophthirus carlinii (Anoplura: Echinophthiriidae), a new species from the Weddell seal Leptonychotes weddelli.

    PubMed

    Leonardi, María Soledad; Poljak, Sebastián; Carlini, Pedro; Galliari, Juan; Bobinac, Magalí; Santos, Mercedes; Márquez, María E; Negrete, Javier

    2014-11-01

    As a part of an ongoing long-term study on the biology of pack-ice seals in Antarctica, we had the opportunity to collect lice from Weddell seals (Leptonychotes weddelli). We did not find the original description of this host-parasite association. Antarctophthirus ogmorhini had previously been reported as a parasite for the Weddell seal, but the information is, to a certain extent, confusing. During the development of the present study, we had access to literature concerning the presence of A. ogmorhini on this host, which, to our knowledge, was not determined in any of the previous works on this species. We compared lice collected from Weddell seals with A. ogmorhini obtained from the type host, the leopard seal (Hydrurga leptonyx), and we found that both species can be distinguished. The main differences are the characteristic pattern of chaetotaxy in the dorsal side of the head in lice from Weddell seals, the size and form of the pseudopenis, and the distribution and size of the fringe of setae surrounding the genital opening. Considering the conservative morphology, and ecological and evolutionary features of sucking lice, we proposed that lice from Weddell seals constitute a new species. In the present work, we described and illustrated adults of this new species collected from Weddell seals during the austral summer of 2014 at the Danco Coast, Antarctic Peninsula.

  5. Variation in probability of first reproduction of Weddell seals

    USGS Publications Warehouse

    Hadley, G.L.; Rotella, J.J.; Garrott, R.A.; Nichols, J.D.

    2006-01-01

    Summary 1. For many species, when to begin reproduction is an important life-history decision that varies by individual and can have substantial implications for lifetime reproductive success and fitness. 2. We estimated age-specific probabilities of first-time breeding and modelled variation in these rates to determine age at first reproduction and understand why it varies in a population of Weddell seals in Erebus Bay, Antarctica. We used multistate mark?recapture modelling methods and encounter histories of 4965 known-age female seals to test predictions about age-related variation in probability of first reproduction and the effects of annual variation, cohort and population density. 3. Mean age at first reproduction in this southerly located study population (7.62 years of age, SD =1.71) was greater than age at first reproduction for a Weddell seal population at a more northerly and typical latitude for breeding Weddell seals (mean =4?5 years of age). This difference suggests that age at first reproduction may be influenced by whether a population inhabits the core or periphery of its range. 4. Age at first reproduction varied from 4 to 14 years, but there was no age by which all seals recruited to the breeding population, suggesting that individual heterogeneity exists among females in this population. 5. In the best model, the probability of breeding for the first time varied by age and year, and the amount of annual variation varied with age (average variance ratio for age-specific rates =4.3%). 6. Our results affirmed the predictions of life-history theory that age at first reproduction in long-lived mammals will be sensitive to environmental variation. In terms of life history evolution, this variability suggests that Weddell seals display flexibility in age at first reproduction in order to maximize reproductive output under varying environmental conditions. Future analyses will attempt to test predictions regarding relationships between environmental

  6. Isolation and partial characterization of a parapoxvirus isolated from a skin lesion of a Weddell seal.

    PubMed

    Tryland, M; Klein, J; Nordøy, E S; Blix, A S

    2005-03-01

    A solitary skin lesion was found on the neck of a Weddell seal (Leptonychotes weddellii), chemically immobilized in Queen Maud Land (70 degrees 09'S, 05 degrees 22'E) Antarctica 2001. The lesion was elevated and 3cm in diameter, consisting of partly fresh and partly necrotic tissue, and proliferative papilloma-like structures were seen. Electron microscopy on a biopsy from the lesion revealed typical parapoxvirus particles. Polymerase chain reaction (PCR; B2L gene) generated amplicons of approximately 594 base pairs, comparable to Orf-virus, the prototype parapoxvirus. A comparison of these B2L PCR amplicon DNA sequences with corresponding sequences from other parapoxviruses, showed that the Weddell seal virus resembled isolates from grey seal (Halichoerus grypus) and harbour seal (Phoca vitulina) more than parapoxvirus from red deer (Cervus elaphus), sheep, cattle and Japanese serows (Capricornis crispus). It is thus concluded that the Weddell seal parapoxvirus belong to the tentative seal parapoxvirus species. Since parapox and orthopoxviruses may cause similar clinical diseases, we suggest that the term sealpox should be restricted to the clinical disease, whereas seal parapoxvirus should be used when caused by a parapoxvirus, rather than the general term "sealpox virus". This is the first verified case of parapoxvirus infection in a Weddell seal, and also the first report of any such infections in the Antarctic.

  7. Perfluoroalkyl substances detected in the world's southernmost marine mammal, the Weddell seal (Leptonychotes weddellii).

    PubMed

    Routti, Heli; Krafft, Bjørn A; Herzke, Dorte; Eisert, Regina; Oftedal, Olav

    2015-02-01

    This study investigates concentrations of 18 perfluoroalkyl substances (PFAS) in blood plasma of adult lactating Weddell seals (Leptonychotes weddellii) (n = 10) from McMurdo Sound, Antarctica. Perfluoroundecanoic acid (PFUnDA) was detected in all samples at concentrations ranging from 0.08 to 0.23 ng/ml. Perfluorooctane sulfonate (PFOS), perfluorohexanoate (PFHxA) and perfluorotridecanoate (PFTriDA) were sporadically detected, while the remaining compounds were below the limit of detection. This is the first report of detectible concentrations of PFASs in an endemic Antarctic marine mammal species. We suggest that the pollutants have been subjected to long range atmospheric transportation and/or derive from a local source. A review of these and published data indicate that perfluoroalkyl carboxylates (PFCAs) dominate in biotic PFAS patterns in species feeding south of the Antarctic Circumpolar Current (ACC), whereas PFOS was the major PFAS detected in species feeding predominantly north of the current.

  8. Scaling matters: incorporating body composition into Weddell seal seasonal oxygen store comparisons reveals maintenance of aerobic capacities.

    PubMed

    Shero, Michelle R; Costa, Daniel P; Burns, Jennifer M

    2015-10-01

    Adult Weddell seals (Leptonychotes weddellii) haul-out on the ice in October/November (austral spring) for the breeding season and reduce foraging activities for ~4 months until their molt in the austral fall (January/February). After these periods, animals are at their leanest and resume actively foraging for the austral winter. In mammals, decreased exercise and hypoxia exposure typically lead to decreased production of O2-carrying proteins and muscle wasting, while endurance training increases aerobic potential. To test whether similar effects were present in marine mammals, this study compared the physiology of 53 post-molt female Weddell seals in the austral fall to 47 pre-breeding females during the spring in McMurdo Sound, Antarctica. Once body mass and condition (lipid) were controlled for, there were no seasonal changes in total body oxygen (TBO2) stores. Within each season, hematocrit and hemoglobin values were negatively correlated with animal size, and larger animals had lower mass-specific TBO2 stores. But because larger seals had lower mass-specific metabolic rates, their calculated aerobic dive limit was similar to smaller seals. Indicators of muscular efficiency, myosin heavy chain composition, myoglobin concentrations, and aerobic enzyme activities (citrate synthase and β-hydroxyacyl CoA dehydrogenase) were likewise maintained across the year. The preservation of aerobic capacity is likely critical to foraging capabilities, so that following the molt Weddell seals can rapidly regain body mass at the start of winter foraging. In contrast, muscle lactate dehydrogenase activity, a marker of anaerobic metabolism, exhibited seasonal plasticity in this diving top predator and was lowest after the summer period of reduced activity.

  9. Assessment of legacy and emerging persistent organic pollutants in Weddell seal tissue (Leptonychotes weddellii) near McMurdo Sound, Antarctica.

    PubMed

    Trumble, Stephen J; Robinson, Eleanor M; Noren, Shawn R; Usenko, Sascha; Davis, Jay; Kanatous, Shane B

    2012-11-15

    Muscle samples were collected from pup, juvenile and adult Weddell seals (Leptonychotes weddellii) near McMurdo Sound, Antarctica during the austral summer of 2006. Blubber samples were collected from juvenile and adult seals. Samples were analyzed for emerging and legacy persistent organic pollutants (POPs) including current and historic-use organochlorine pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). Of the 41 target analytes, 28 contaminants were recovered from the Weddell seal blubber, in this order of prevalence: p,p'-DDE, p,p'-DDT, trans-nonachlor, mirex, cis-nonachlor, PCB 153, PCB 138, dieldrin, heptachlor epoxide, nonachlor III, PCB 187, oxychlordane, cis-chlordane, PCB 118, PBDE 47, PCB 156, PCB 149, PCB 180, PCB 101, PCB 170, PCB 105, o,p'-DDT, PCB 99, trans-chlordane, PCB 157, PCB 167, PCB 189, and PCB 114. Fewer POPs were found in the muscle samples, but were similar in the order of prevalence to that of the blubber: p,p'-DDE, o,p'-DDT, trans-nonachlor, nonachlor III, oxychlordane, p,p'-DDT, dieldrin, mirex, cis-nonachlor, PCB 138, and PCB 105. Besides differences in toxicant concentrations reported between the muscle and blubber, we found differences in POP levels according to age class and suggest that differences in blubber storage and/or mobilization of lipids result in age class differences in POPs. To our knowledge, such ontogenetic associations are novel. Importantly, data from this study suggest that p,p'-DDT is becoming less prevalent temporally, resulting in an increased proportion of its metabolite p,p'-DDE in the tissues of this top predator. In addition, this study is among the first to identify a PBDE congener in Weddell seals near the McMurdo Station. This may provide evidence of increased PBDE transport and encroachment in Antarctic wildlife.

  10. Indication of geographic variaritions of organochlorine concentrations in the blubber of Antarctic Weddell seals (Leptonychotes weddelli).

    PubMed

    Vetter, Walter; Weichbrodt, Marion; Stoll, Elke

    2003-03-01

    A sample cleanup procedure using microwave-assisted extraction (MAE) with focus open vessel (FOV-MAE) technique was validated for the determination of organohalogen compounds in the blubber of a Weddell seal (Leptonychotes Weddelli) from the Antarctic (King George Island, 62 degrees 14' S, 58 degrees 40' W). Good reproducibility in replicate analysis of samples confirms the suitability of the method for samples with very low persistent organic pollutant (POP) concentrations. The method was used to analyze three additional blubber samples of Weddell seals from King George Island. This community of Weddell seals showed the lowest DDT (11-19 microg/kg) and PCB (1-2.5 microg/kg) concentrations so far detected in comparable marine mammals from all over the world. The concentrations determined in the four Weddell seals were also typical for the population at King George Island. However, the DDT and PCB concentrations on King George Island were one order of magnitude lower than in samples of the same species from other sites in the Antarctic (located between 69 degrees S and 78 degrees S). This suggests a wide variability of organohalogen levels in the Antarctic, depending on the geographic site. King George Island (62 degrees S) is found at the outskirts of the Antarctic Peninsula, i.e., the region with the mildest climate in the Antarctic. Low organohalogen levels at this site were attributed to a lower degree of condensation in comparison with locations further south. Most of the reference samples were taken in the Weddell and Ross Seas, i.e., from coastlines as close as possible to the pole. Consequently, other sites on the same latitude as the Weddell and Ross Seas are found on the Antarctic continent This raises the question whether high proportions of organohalogens are being deposited on the Antarctic continent where they are not available to marine organisms. Although this hypothesis has to be proven in follow-up studies, our study clearly demonstrates that it is

  11. Environmental correlates of temporary emigration for female Weddell seals and consequences for recruitment

    USGS Publications Warehouse

    Stauffer, Glenn E.; Rotella, Jay J.; Garrott, Robert A.; Kendall, William

    2014-01-01

    In colonial-breeding species, prebreeders often emigrate temporarily from natal reproductive colonies then subsequently return for one or more years before producing young. Variation in attendance–nonattendance patterns can have implications for subsequent recruitment. We used open robust-design multistate models and 28 years of encounter data for prebreeding female Weddell seals (Leptonychotes weddellii [Lesson]) to evaluate hypotheses about (1) the relationships of temporary emigration (TE) probabilities to environmental and population size covariates and (2) motivations for attendance and consequences of nonattendance for subsequent probability of recruitment to the breeding population. TE probabilities were density dependent (βˆBPOP = 0.66,  = 0.17; estimated effects [β] and standard errors of population size in the previous year) and increased when the fast-ice edge was distant from the breeding colonies (βˆDIST = 0.75,  = 0.04; estimated effects and standard errors of distance to the sea-ice edge in the current year on TE probability in the current year) and were strongly age and state dependent. These results suggest that trade-offs between potential benefits and costs of colony attendance vary annually and might influence motivation to attend colonies. Recruitment probabilities were greatest for seals that consistently attended colonies in two or more years (e.g.,  = 0.56, SD = 0.17) and lowest for seals that never or inconsistently attended prior to recruitment (e.g.,  = 0.32, SD = 0.15), where denotes the mean recruitment probability (over all years) for 10-year-old seals for the specified prebreeder state. In colonial-breeding seabirds, repeated colony attendance increases subsequent probability of recruitment to the adult breeding population; our results suggest similar implications for a marine mammal and are consistent with the hypothesis that prebreeders were motivated to attend reproductive colonies to gain reproductive skills or

  12. Diel and seasonal patterns of underwater sounds by Weddell seals, leopard seals, and killer whales in the Antarctic: When it's adaptive to be quiet

    NASA Astrophysics Data System (ADS)

    Mindach, Debrah; Thomas, Jeanette

    2005-09-01

    Automated underwater recordings taken during the austral breeding season of the Weddell seal (Leptonychotes weddellii) in Antarctica also provided data on the vocalizations of predators in the area; leopard seals (Hydrurga leptonyx) and killer whales (Orcinus orca). Weddell seals inhabit fast ice areas to give birth, mate, and molt. Near the end of the breeding season in December the fast ice often breaks out and the two pack ice predators are able to move near the Weddell seal colonies and prey on them, especially pups. Recordings were taken continuously for a 2.5-min period each hour from mid-October 1977 and late-January 1978 at Hutton Cliffs and South Turtle Rock Crack, in McMurdo Sound. The leopard seals increased their trill calls when killer whales came into the area as evidenced by an increase in their frequency-modulated squeak calls. Weddell seals decreased their vocalization rate dramatically (~10 sounds/min) compared to during the peak of the breeding season (~75 sounds/min). Perhaps by being quiet, Weddell seals do not attract predators to their area.

  13. Coping with the loss of large, energy-dense prey: a potential bottleneck for Weddell Seals in the Ross Sea.

    PubMed

    Salas, Leo; Nur, Nadav; Ainley, David; Burns, Jennifer; Rotella, Jay; Ballard, Grant

    2017-01-01

    Extraction of Antarctic toothfish (Dissostichus mawsoni) in the Ross Sea began in 1997, following a management plan that targets the largest fish with a goal of reducing the spawning biomass by 50% over 35 yr. We investigate the potential long-term consequences of the reduced availability of this prey for Weddell seals (Leptonychotes weddellii). Energy demands in seals are acute, especially immediately following lactation, when females must recover substantial mass and cope with molting costs. We tested the hypothesis that toothfish are critically important for adult female seals during this period. Toothfish body mass is three orders of magnitude greater, and its energy density nearly double that of the most common seal prey, Antarctic silverfish (Pleuragramma antarcticum). Reduction or elimination of toothfish consumption could impair a female's ability to sufficiently recover and successfully produce a pup in the following pupping season. Our goals are to (1) illustrate mechanisms and conditions whereby toothfish depletion might plausibly affect seal population trends; (2) identify measurable parameters of the seals' ecology that may help better understand the potential negative impact of toothfish depletion on seal populations; and (3) promote a precautionary management approach for the fishery that includes monitoring of seal populations We constructed a set of inter-linked models of seal diving behavior, physiological condition, and demography based on existing information. We evaluate the effect of the following factors on seal mass recovery and intrinsic population growth rates: fishery depletion rate, daily diving limits, probability of a successful dive, and body mass recovery target. We show that loss of toothfish has the greatest potential impact on seal populations' growth rate. Under some scenarios, populations may decrease at >10% per year. Critical parameters to better understand fishery impacts include prevalence and size of toothfish in the seals

  14. Milk composition in the Weddell seal Leptonychotes weddellii: evidence for a functional role of milk carbohydrates in pinnipeds.

    PubMed

    Eisert, Regina; Oftedal, Olav T; Barrell, Graham K

    2013-01-01

    We propose that secretion of milk sugar has important consequences for the metabolic economies of lactating phocid seals and their pups. Milk was collected from 21 Weddell seals Leptonychotes weddellii in McMurdo Sound, Antarctica, and assayed by standard methods. Milk composition changed over the course of lactation, but at mid- to late lactation (16-40 d postpartum), Weddell seal milk composition was relatively constant at 33.8% +/- 0.82% water, 54.0% +/- 0.80% fat, 10.1% +/- 0.16% crude protein, 0.84% +/- 0.03% sugar, 0.75% +/- 0.02% ash, and 23.3 +/- 0.3 kJ g−1 whole milk (WM). At this stage, milk composition varied among individual seals in all assayed constituents except ash. The concentration of sugar in the aqueous phase of Weddell seal milk ( 24.9 +/- 0.6g sugar L−1 water) was ca. 44%-77% of levels found in terrestrial carnivores, indicating that the low sugar concentration of WM is primarily due to its high fat content, not alteration of the aqueous phase. In early lactation, fasting Weddell seals were estimated to devote 39 g d(-1) glucose to milk sugar synthesis, an amount similar to the estimated demand of the maternal brain. This additional glucose demand must be covered by gluconeogenesis in fasting animals and represents a considerable additional drain on maternal resources. However, provision of sugar to offspring at rates sufficient to meet neonatal substrate requirements appears to be essential for efficient fat and protein deposition and thus may be an important component of the phocid reproductive strategy of rapid growth and early weaning.

  15. Classification and behavior of free-ranging Weddell seal dives based on three-dimensional movements and video-recorded observations

    NASA Astrophysics Data System (ADS)

    Davis, Randall W.; Fuiman, Lee A.; Madden, Kiersten M.; Williams, Terrie M.

    2013-04-01

    The goal of this study was to classify free-ranging (FR) dives of Weddell seals (Leptonychotes weddellii) and to compare them to isolated hole (IH) dives. Classification and comparisons were based on 58 descriptors for three-dimensional dive paths computed from data obtained by attaching video and data recorders to the backs of 12 adult Weddell seals that were free-ranging in eastern McMurdo Sound, Antarctica. We then inferred behavioral functions for the dive classes based on video-recorded observations. Three of the four dive types previously identified from seals diving at an IH occurred in FR seals. Although there were differences associated with location, Types 1, 2 and 3 dives clustered in a similar pattern in the discriminant analysis for FR and IH dives. Most prey (79%) captures occurred during Type 1 dives, and the primary (99%) prey was Antarctic silverfish (Pleuragramma antarcticum). Type 1 dives were the deepest (mean maximum depth 324-378 m), longest in duration (15.0-27.0 min), covered the greatest total distance (1470-2197 m), and had the steepest dive angles (descents: -30°; ascents: +27°). Types 2 and 3 dives formed a continuum from short duration (3.6-7.5 min), shallow (mean maximum depth 30-66 m) dives that were close to the ice hole (farpoint distance 75-130 m) and often involved aggressive interactions with other seals for breathing opportunities (Type 2) to progressively longer (7.9-17.2 min), deeper (mean maximum depth 81-143 m) dives that covered greater total distances (878-1194 m) and were associated with transiting between holes, exploring and occasionally foraging (Type 3). Very long distance Type 4 exploratory dives that were identified in the IH study were completely absent in FR seals.

  16. An evaluation of density-dependent and density-independent influences on population growth rates in Weddell seals

    USGS Publications Warehouse

    Rotella, J.J.; Link, W.A.; Nichols, J.D.; Hadley, G.L.; Garrott, R.A.; Proffitt, K.M.

    2009-01-01

    Much of the existing literature that evaluates the roles of density-dependent and density-independent factors on population dynamics has been called into question in recent years because measurement errors were not properly dealt with in analyses. Using state-space models to account for measurement errors, we evaluated a set of competing models for a 22-year time series of mark-resight estimates of abundance for a breeding population of female Weddell seals (Leptonychotes weddellii) studied in Erebus Bay, Antarctica. We tested for evidence of direct density dependence in growth rates and evaluated whether equilibrium population size was related to seasonal sea-ice extent and the Southern Oscillation Index (SOI). We found strong evidence of negative density dependence in annual growth rates for a population whose estimated size ranged from 438 to 623 females during the study. Based on Bayes factors, a density-dependence-only model was favored over models that also included en! vironmental covariates. According to the favored model, the population had a stationary distribution with a mean of 497 females (SD = 60.5), an expected growth rate of 1.10 (95% credible interval 1.08-1.15) when population size was 441 females, and a rate of 0.90 (95% credible interval 0.87-0.93) for a population of 553 females. A model including effects of SOI did receive some support and indicated a positive relationship between SOI and population size. However, effects of SOI were not large, and including the effect did not greatly reduce our estimate of process variation. We speculate that direct density dependence occurred because rates of adult survival, breeding, and temporary emigration were affected by limitations on per capita food resources and space for parturition and pup-rearing. To improve understanding of the relative roles of various demographic components and their associated vital rates to population growth rate, mark-recapture methods can be applied that incorporate both

  17. Field use of ultrasonography to characterize the reproductive tract and early pregnancy in a phocid, the Weddell seal (Leptonychotes weddellii).

    PubMed

    Shero, Michelle R; Adams, Gregg P; Burns, Jennifer M

    2015-12-01

    The utility of transrectal ultrasonography was tested in a field setting to characterize the reproductive tract and detect early pregnancy (embryonic vesicles < 3 mm in diameter) in 17 multiparous female Weddell seals (Leptonychotes weddellii). Female Weddell seals give birth in October/November each year, followed by the breeding season (December) and embryonic diapause. Transrectal ultrasonography was attempted in January/February 2014 to examine the entire reproductive tract (uterine horns and body, ovaries with follicles and corpora lutea) using a 5-10 MHz linear-array probe with a 70 cm-long extension. A single pregnancy was detected in 14 of 17 seals (82.4%) as a circular or guitar-pick shaped nonechogenic (black) vesicle with a clearly visible echogenic border within the lumen of the uterus. The stage of embryonic development (ostensibly the gestational age) varied markedly among individuals, ranging from a vesicle with no embryo proper to a large fetus with an ocular orbit, nose/mouth, limb buds, spinal column, umbilical cord, and prominent vasculature. Two of the pregnant seals were re-examined 3-6 days after the initial examination to obtain longitudinal growth rates. Images of one or both ovaries were obtained in nine and seven of the 19 examinations, respectively. Numerous ovarian follicles (3 to 12 mm diameter) were detected and animals typically had a single well-perfused corpus luteum (determined by Doppler color-flow) ipsilateral to the uterine horn containing the pregnancy. We conclude that real-time transrectal ultrasonography is an effective tool for characterizing reproductive events in phocids including ovarian dynamics, and for elucidating the nature of embryonic diapause.

  18. Effects of hydrographic variability on the spatial, seasonal and diel diving patterns of southern elephant seals in the eastern Weddell Sea.

    PubMed

    Biuw, Martin; Nøst, Ole Anders; Stien, Audun; Zhou, Qin; Lydersen, Christian; Kovacs, Kit M

    2010-11-03

    Weddell Sea hydrography and circulation is driven by influx of Circumpolar Deep Water (CDW) from the Antarctic Circumpolar Current (ACC) at its eastern margin. Entrainment and upwelling of this high-nutrient, oxygen-depleted water mass within the Weddell Gyre also supports the mesopelagic ecosystem within the gyre and the rich benthic community along the Antarctic shelf. We used Conductivity-Temperature-Depth Satellite Relay Data Loggers (CTD-SRDLs) to examine the importance of hydrographic variability, ice cover and season on the movements and diving behavior of southern elephant seals in the eastern Weddell Sea region during their overwinter feeding trips from Bouvetøya. We developed a model describing diving depth as a function of local time of day to account for diel variation in diving behavior. Seals feeding in pelagic ice-free waters during the summer months displayed clear diel variation, with daytime dives reaching 500-1500 m and night-time targeting of the subsurface temperature and salinity maxima characteristic of CDW around 150-300 meters. This pattern was especially clear in the Weddell Cold and Warm Regimes within the gyre, occurred in the ACC, but was absent at the Dronning Maud Land shelf region where seals fed benthically. Diel variation was almost absent in pelagic feeding areas covered by winter sea ice, where seals targeted deep layers around 500-700 meters. Thus, elephant seals appear to switch between feeding strategies when moving between oceanic regimes or in response to seasonal environmental conditions. While they are on the shelf, they exploit the locally-rich benthic ecosystem, while diel patterns in pelagic waters in summer are probably a response to strong vertical migration patterns within the copepod-based pelagic food web. Behavioral flexibility that permits such switching between different feeding strategies may have important consequences regarding the potential for southern elephant seals to adapt to variability or systematic

  19. Density of pack-ice seals and penguins in the western Weddell Sea in relation to ice thickness and ocean depth

    NASA Astrophysics Data System (ADS)

    Flores, Hauke; Haas, Christian; van Franeker, Jan Andries; Meesters, Erik

    2008-04-01

    Aerial band transect censuses were carried out parallel with ice thickness profiling surveys in the pack ice of the western Weddell Sea during the ISPOL (Ice Station POLarstern) expedition of R.V. Polarstern from November 2004 to January 2005. Three regions were surveyed: the deep sea of the Weddell Sea, a western continental shelf/slope region where R.V. Polarstern passively drifted with an ice floe (ISPOL), and a northern region (N). Animal densities were compared among regions and in relation to bathymetry and ice thickness distribution. Crabeater seals Lobodon carcinophaga were the most abundant species in all three regions. Their density was significantly lower in the deep sea (0.50 km -2) than in the ISPOL (1.00 km -2) and northern regions (1.21 km -2). Weddell seals Leptonychotes weddellii were not sighted in the deep-sea region, their density elsewhere ranging from 0.03 (N) to 0.08 km -2 (ISPOL). Leopard seals Hydrurga leptonyx were observed in all three areas, but could only be quantified in the deep-sea (0.05 km -2) and northern regions (0.06 km -2). The abundance of emperor penguins Aptenodytes forsteri was markedly higher in the northern (0.75 km -2) than in the ISPOL (0.13 km -2) and the deep-sea region (not quantified). Crabeater seal density was significantly related to ocean depth and modal ice thickness.

  20. Evaluating the demographic buffering hypothesis with vital rates estimated for Weddell seals from 30years of mark-recapture data

    USGS Publications Warehouse

    Rotella, J.J.; Link, W.A.; Chambert, T.; Stauffer, G.E.; Garrott, R.A.

    2012-01-01

    1.Life-history theory predicts that those vital rates that make larger contributions to population growth rate ought to be more strongly buffered against environmental variability than are those that are less important. Despite the importance of the theory for predicting demographic responses to changes in the environment, it is not yet known how pervasive demographic buffering is in animal populations because the validity of most existing studies has been called into question because of methodological deficiencies. 2.We tested for demographic buffering in the southern-most breeding mammal population in the world using data collected from 5558 known-age female Weddell seals over 30years. We first estimated all vital rates simultaneously with mark-recapture analysis and then estimated process variance and covariance in those rates using a hierarchical Bayesian approach. We next calculated the population growth rate's sensitivity to changes in each of the vital rates and tested for evidence of demographic buffering by comparing properly scaled values of sensitivity and process variance in vital rates. 3.We found evidence of positive process covariance between vital rates, which indicates that all vital rates are affected in the same direction by changes in annual environment. Despite the positive correlations, we found strong evidence that demographic buffering occurred through reductions in variation in the vital rates to which population growth rate was most sensitive. Process variation in vital rates was inversely related to sensitivity measures such that variation was greatest in breeding probabilities, intermediate for survival rates of young animals and lowest for survival rates of older animals. 4.Our work contributes to a small but growing set of studies that have used rigorous methods on long-term, detailed data to investigate demographic responses to environmental variation. The information from these studies improves our understanding of life

  1. Skin microbial flora and effectiveness of aseptic technique for deep muscle biopsies in Weddell seals (Leptonychotes weddellii ) in McMurdo Sound, Antarctica.

    PubMed

    Mellish, J; Tuomi, P; Hindle, A; Jang, S; Horning, M

    2010-04-01

    Deep muscle biopsies were collected from the pectoralis and longissimus dorsi of wild Weddell seals (Leptonychotes weddellii) in McMurdo Sound, Antarctica, during October-December 2007. Sterile swabs were collected from the surface of each skin site before biopsy and from the deep-needle path after biopsy. No growth occurred in two of six pectoralis and three of six longissimus skin sites, or in four of 10 pectoralis deep biopsy and eight of 12 longissimus deep-biopsy sites. Positive skin culture was not predictive of deep-biopsy contamination, nor did contamination at one body location correlate with contamination at the second site. Psychrobacter species were most common in one or more samples from each of the four sample types. Only one of the eight documented bacteria exhibited resistance to commonly used antibiotics.

  2. Occurrence of microbial indicators and Clostridium perfringens in wastewater, water column samples, sediments, drinking water, and Weddell seal feces collected at McMurdo Station, Antarctica.

    PubMed

    Lisle, John T; Smith, James J; Edwards, Diane D; McFeters, Gordon A

    2004-12-01

    McMurdo Station, Antarctica, has discharged untreated sewage into McMurdo Sound for decades. Previous studies delineated the impacted area, which included the drinking water intake, by using total coliform and Clostridium perfringens concentrations. The estimation of risk to humans in contact with the impacted and potable waters may be greater than presumed, as these microbial indicators may not be the most appropriate for this environment. To address these concerns, concentrations of these and additional indicators (fecal coliforms, Escherichia coli, enterococci, coliphage, and enteroviruses) in the untreated wastewater, water column, and sediments of the impacted area and drinking water treatment facility and distribution system at McMurdo Station were determined. Fecal samples from Weddell seals in this area were also collected and analyzed for indicators. All drinking water samples were negative for indicators except for a single total coliform-positive sample. Total coliforms were present in water column samples at higher concentrations than other indicators. Fecal coliform and enterococcus concentrations were similar to each other and greater than those of other indicators in sediment samples closer to the discharge site. C. perfringens concentrations were higher in sediments at greater distances from the discharge site. Seal fecal samples contained concentrations of fecal coliforms, E. coli, enterococci, and C. perfringens similar to those found in untreated sewage. All samples were negative for enteroviruses. A wastewater treatment facility at McMurdo Station has started operation, and these data provide a baseline data set for monitoring the recovery of the impacted area. The contribution of seal feces to indicator concentrations in this area should be considered.

  3. Occurrence of microbial indicators and Clostridium perfringens in wastewater, water column samples, sediments, drinking water, and Weddell seal feces collected at McMurdo Station, Antarctica

    USGS Publications Warehouse

    Lisle, J.T.; Smith, J.J.; Edwards, D.D.; McFeters, G.A.

    2004-01-01

    McMurdo Station, Antarctica, has discharged untreated sewage into McMurdo Sound for decades. Previous studies delineated the impacted area, which included the drinking water intake, by using total coliform and Clostridium perfringens concentrations. The estimation of risk to humans in contact with the impacted and potable waters may be greater than presumed, as these microbial indicators may not be the most appropriate for this environment. To address these concerns, concentrations of these and additional indicators (fecal coliforms, Escherichia coli, enterococci, coliphage, and enteroviruses) in the untreated wastewater, water column, and sediments of the impacted area and drinking water treatment facility and distribution system at McMurdo Station were determined. Fecal samples from Weddell seals in this area were also collected and analyzed for indicators. All drinking water samples were negative for indicators except for a single total coliform-positive sample. Total coliforms were present in water column samples at higher concentrations than other indicators. Fecal coliform and enterococcus concentrations were similar to each other and greater than those of other indicators in sediment samples closer to the discharge site. C. perfringens concentrations were higher in sediments at greater distances from the discharge site. Seal fecal samples contained concentrations of fecal coliforms, E. coli, enterococci, and C. perfringens similar to those found in untreated sewage. All samples were negative for enteroviruses. A wastewater treatment facility at McMurdo Station has started operation, and these data provide a baseline data set for monitoring the recovery of the impacted area. The contribution of seal feces to indicator concentrations in this area should be considered.

  4. Experiments directed to the compound-specific determination of the stable carbon isotope ratios of the Toxaphene congener B8-1413 in two technical mixtures and Antarctic Weddell seal.

    PubMed

    Vetter, Walter; Schlatterer, Jörg; Gleixner, Gerd

    2006-03-31

    The carbon stable isotope ratio (delta(13)C value) of an environmentally-relevant Toxaphene congener in technical products and a biological sample from a remote region was in the focus of this work. For this reason, the major octachlorobornane residue of the multicomponent pesticide Toxaphene in biological samples, 2-endo,3-exo,5-endo,6-exo,8,8,10,10-octachlorobornane (B8-1413 or P26), was quantitatively enriched from two technical Toxaphene mixtures (Toxaphene and Melipax) in duplicates as well as from an Antarctic Weddell seal sample. Normal phase followed by reversed-phase high-performance liquid chromatography (HPLC) with three columns, respectively, coupled in series was used for this purpose. Four of the five fractionated samples fulfilled the requirement of an interference-free GC-elution for subsequent determination of the delta(13)C value by gas chromatography interfaced to an isotope ratio mass spectrometer (GC-IRMS). B8-1413 in Toxaphene (n=1) was more depleted in (12)C than in Melipax (n=2), which agrees with previous results obtained for the entire mixtures. The B8-1413 isolate from a Weddell seal sample from the Antarctic showed a delta(13)C value between the two technical products. Although a source appointment to the one or the other product was not possible, this example indicates that long range transport to the Antarctic and by uptake and food-chain bioaccumulation of B8-1413 in seals did not change the delta(13)C value significantly. The observed differences in one duplicate sample indicate that statistic evaluation of samples used for isotope ratio MS measurements is an important issue.

  5. Phagocytosis in pup and adult harbour, grey and harp seals.

    PubMed

    Frouin, Héloïse; Lebeuf, Michel; Hammill, Mike; Fournier, Michel

    2010-04-15

    Knowledge on pinniped immunology is still in its infancy. For instance, age-related and developmental aspects of the immune system in pinnipeds need to be better described. The present study examined the phagocytic activity and efficiency of harbour, grey and harp seal leukocytes. In the first part of the study, peripheral blood was collected from captive female harbour seals of various ages. Data showed an age-related decrease in phagocytosis in female harbour seals from sub-adult to adulthood. In the second part of the study, changes in phagocytosis were quantified during lactation in wild newborn harbour, grey and harp seals and in their mothers (harp and grey seals). In newborns of the same age, leukocytes of harbour and harp seals phagocytosed less than those of grey seal pups. The phagocytic activity and efficiency increased significantly from early to mid-lactation in newborn harbour seals, and from early to late lactation in newborn grey seals, which could suggest that the transfer of phagocytosis-promoting factor(s) in colostrum is an important feature of temporary protection for pups. In contrast, no changes in phagocytic activity and efficiency were observed in lactating females of the two seal species, harp and grey, examined. At late lactation, phagocytic activity in both grey and harp seal pups and phagocytic efficiency in grey seal pups were significantly higher than in their mothers. These results could reflect either the capacity of phagocytes of the newborn harp and grey seals to respond to pathogens. Results from this study suggest that the phagocytosis of the seal species examined is not fully developed at birth as it generally increases in pups during lactation. Thereafter, the phagocytic activity of seals appears to decrease throughout adulthood.

  6. Transfer of individual chlorobiphenyls from adult female grey seals to their offspring via milk

    SciTech Connect

    Green, N.J.L.; Jones, K.C.; Pomeroy, P.P.; Harwood, J.

    1994-12-31

    Branded individual grey seals (Halichoerus grypus) have been monitored on the Isle of May, Scotland over a three year period to investigate the influence of polychlorinated biphenyls (PCBs) on their health. Simultaneous sampling of milk, blood and adipose tissue from weaning mothers has enabled a detailed analysis of the release of individual chlorobiphenyls from a mother seal`s fat reserves, and their availability to the seal`s offspring through lactation. Transfer coefficients have been calculated for 22 individual congeners for their mobilization from adipose to blood, and for their incorporation from blood into milk. The overall transfer from blubber to milk decreased with increasing chlorination from ca 0.6 for tetra- to < 0.1 for octa- and nona-chlorinated biphenyls. Fat samples from 21 pups of the study adults were analyzed for the same chlorobiphenyl congeners. No congener selectivity was observable for the combined uptake and storage processes of these chlorobiphenyls by the pups.

  7. Angiotensin II and aldosterone increase with fasting in breeding adult male northern elephant seals (Mirounga angustirostris).

    PubMed

    Ortiz, Rudy M; Crocker, Daniel E; Houser, Dorian S; Webb, Paul M

    2006-01-01

    The renin-angiotensin-aldosterone system (RAAS) appears to contribute significantly to osmoregulation of fasting northern elephant seal (Mirounga angustirostris) pups; however, RAAS has not been characterized in fasting adult seals. Therefore, this study examined the contribution of RAAS to water turnover rates in fasting adult male northern elephant seals. Blood samples were obtained twice during their breeding fast at an interval of 6.5 wk, and water efflux rate was estimated by isotopic dilution during the same period. Serum electrolytes (Na+, K+, Cl-) and osmolality were unaltered between the two sampling periods, indicating ionic and osmotic homeostasis during the fast. Despite the lack of an increase in vasopressin, serum angiotensin II and aldosterone were increased and were significantly and positively correlated. Changes in aldosterone concentration and water efflux rate were significantly and negatively correlated, suggesting that the greater the increase in aldosterone, the smaller the loss of water. Adult male seals maintain ionic and osmotic homeostasis similar to that of fasting weaned pups, and this homeostasis appears to be mediated, at least in part, by RAAS, which probably contributes to increased water retention as well. The hormonal mechanisms by which northern elephant seals maintain water and electrolyte balance during fasting conditions appear to be similar regardless of age.

  8. Assessment of harbor seal predation on adult salmonids in a Pacific Northwest estuary.

    PubMed

    Wright, Bryan E; Riemer, Susan D; Brown, Robin F; Ougzin, Aicha M; Bucklin, Katherine A

    2007-03-01

    The populations of many native species have increased or expanded in distribution in recent decades, sometimes with negative consequences to sympatric native species that are rarer or less adaptable to anthropogenic changes to the environment. An example of this phenomenon from the Pacific Northwest is predation by locally abundant pinnipeds (seals and sea lions) on threatened, endangered, or otherwise depleted salmonid (Oncorhynchus spp.) populations. We used survey sampling methodology, acoustic telemetry, and molecular genetics to quantify the amount of harbor seal (Phoca vitulina) predation on a depressed run of coho salmon (O. kisutch) and to determine whether some seals consumed a disproportionately higher number of salmonids than others. Based on a probability sample totaling 759.5 h of observation, we estimated that seals consumed 1161 adult salmonids (95% CI = 503-1818 salmonids) during daylight hours over an 18.9-km estuarine study area in Oregon during an 84-d period in fall 2002. Simultaneous tracking of 56 seals via an acoustic telemetry array indicated that a small proportion of marked seals (12.5%) exhibited behavior that was consistent with specialization on salmonids. These seals spent the majority of their time in the riverine portion of the study area and did so disproportionately more at night than day. Genetic analysis of 116 salmonid structures recovered from 11 seal fecal samples suggested that coho salmon accounted for approximately one-half of total salmonid consumption. Though subject to considerable uncertainty, the combined results lead us to infer that seals consumed 21% (range = 3-63%) of the estimated prespawning population of coho salmon. We speculate that the majority of the predation occurred upriver, at night, and was done by a relatively small proportion of the local seal population. Understanding the extent and nature of pinniped predation can provide important inputs into risk assessments and other modeling efforts designed to

  9. Weddell Sea exploration from ice station

    NASA Astrophysics Data System (ADS)

    Ice Station Weddell Group of Principal Investigators; Chief Scientists; Gordon, Arnold L.

    On January 18, 1915, the Endurance and Sir Ernest Shackleton and his crew were stranded in the ice of the Weddell Sea and began one of the most famous drifts in polar exploration. Shackleton turned a failure into a triumph by leading all of his team to safety [Shackleton, 1919]. The drift track of the Endurance and the ice floe occupied by her stranded crew after the ship was lost on November 21, 1915, at 68°38.5‧S and 52°26.5‧W, carried the group along the western rim of the Weddell Gyre, representing a rare human presence in this region of perennial sea-ice cover.Seventy-seven years later, in 1992, the first intentional scientific Southern Ocean ice drift station, Ice Station Weddell-1 (ISW-1), was established in the western Weddell Sea by a joint effort of the United States and Russia. ISW-1 followed the track of the Endurance closely (Figure 1) and gathered an impressive array of data in this largely unexplored corner of the Southern Ocean, the western edge of the Weddell Gyre.

  10. Physiological effects of seawater intake in adult harp seals during phase I of fasting.

    PubMed

    Storeheier, P V; Nordøy, E S

    2001-02-01

    Previous studies have shown that harp seals may drink considerable amounts of seawater. The current study was undertaken to study the physiological responses to bolus administration of seawater. Adult harp seals (Phoca groenlandica) were fasted without access to water for 48 h and then given 1000 or 1500 ml of seawater by a stomach tube. Changes in urine and plasma parameters were thereafter monitored for another 12-20 h. Urine production and urine excretion rate of Na+ and Cl- increased soon after administration and reached a maximum 3-4 h later. Urine osmolality was kept rather stable and high ( approximately 1500 mOsm x kg(-1)) following seawater administration, due to a drop in urine concentration of urea that was proportional to the simultaneous increase in urine concentration of NaCl. Plasma osmolality remained at approximately 340 mOsm x kg(-1), while plasma concentration of urea decreased some 20-25% due to increased excretion of urea when seawater was ingested. Despite bolus administrations of seawater of up to approximately 2% of body mass, homeostasis was maintained and no ill effects observed. It is concluded that the concentrating abilities of the kidneys of harp seals are sufficient to prevent net loss of body water following seawater ingestion. Seawater ingestion may, moreover, increase urinary osmotic space and thus serve as a mechanism to excrete additional urea produced during phase I of fasting.

  11. Condition and mass impact oxygen stores and dive duration in adult female northern elephant seals.

    PubMed

    Hassrick, J L; Crocker, D E; Teutschel, N M; McDonald, B I; Robinson, P W; Simmons, S E; Costa, D P

    2010-02-15

    The range of foraging behaviors available to deep-diving, air-breathing marine vertebrates is constrained by their physiological capacity to breath-hold dive. We measured body oxygen stores (blood volume and muscle myoglobin) and diving behavior in adult female northern elephant seals, Mirounga angustirostris, to investigate age-related effects on diving performance. Blood volume averaged 74.4+/-17.0 liters in female elephant seals or 20.2+/-2.0% of body mass. Plasma volume averaged 32.2+/-7.8 liters or 8.7+/-0.7% of body mass. Absolute plasma volume and blood volume increased independently with mass and age. Hematocrit decreased weakly with mass but did not vary with age. Muscle myoglobin concentration, while higher than previously reported (7.4+/-0.7 g%), did not vary with mass or age. Pregnancy status did not influence blood volume. Mean dive duration, a proxy for physiological demand, increased as a function of how long seals had been at sea, followed by mass and hematocrit. Strong effects of female body mass (range, 218-600 kg) on dive duration, which were independent of oxygen stores, suggest that larger females had lower diving metabolic rates. A tendency for dives to exceed calculated aerobic limits occurred more frequently later in the at-sea migration. Our data suggest that individual physiological state variables and condition interact to determine breath-hold ability and that both should be considered in life-history studies of foraging behavior.

  12. Isolation and characterization of Campylobacter spp. from Antarctic fur seals (Arctocephalus gazella) at Deception Island, Antarctica.

    PubMed

    García-Peña, F J; Pérez-Boto, D; Jiménez, C; San Miguel, E; Echeita, A; Rengifo-Herrera, C; García-Párraga, D; Ortega-Mora, L M; Pedraza-Díaz, S

    2010-09-01

    The presence of Campylobacter spp. was investigated in 41 Antarctic fur seals (Arctocephalus gazella) and 9 Weddell seals (Leptonychotes weddellii) at Deception Island, Antarctica. Infections were encountered in six Antarctic fur seals. The isolates, the first reported from marine mammals in the Antarctic region, were identified as Campylobacter insulaenigrae and Campylobacter lari.

  13. Environment and activity affect skin temperature in breeding adult male elephant seals (Mirounga angustirostris).

    PubMed

    Norris, A L; Houser, D S; Crocker, D E

    2010-12-15

    The large body size and high rates of metabolic heat production associated with male mating success in polygynous systems creates potential thermoregulatory challenges for species breeding in warm climates. This is especially true for marine predators carrying large blubber reserves intended for thermoregulation in cold water and fuel provision during extended fasts. Thermographic images were used to measure changes in skin temperature (T(S)) in adult male northern elephant seals (Mirounga angustirostris) over the breeding season. Environmental variables, primarily ambient temperature and solar radiation, were the principal determinants of mean and maximum T(S). When controlled for environmental variables, dominance rank significantly impacted mean T(S), being highest in alpha males. Behavioral activity significantly influenced T(S) but in a counter-intuitive way, with inactive males exhibiting the highest T(S). This was likely due to strong impacts of environmental variables on the kinds of behavior exhibited, with males being less active on warm, humid days at peak solar radiation. We classified thermal windows as areas in which T(S) was one standard deviation greater than mean T(S) for the individual seal within a thermograph. Thermal features suggest active physiological thermoregulation during and after combat and significant circulatory adaptations for heat dumping, as evidenced by recurring locations of thermal windows representing widely varying T(S) values. Frequent observations of localized T(S) above 37°C, particularly after combat, suggest the production of thermoregulatory stress during breeding behavior. Our findings demonstrate the importance of environmental drivers in shaping activity patterns during breeding and provide evidence for thermoregulatory costs of successful breeding in large polygynous males.

  14. Population structure of ice-breeding seals.

    PubMed

    Davis, Corey S; Stirling, Ian; Strobeck, Curtis; Coltman, David W

    2008-07-01

    The development of population genetic structure in ice-breeding seal species is likely to be shaped by a combination of breeding habitat and life-history characteristics. Species that return to breed on predictable fast-ice locations are more likely to exhibit natal fidelity than pack-ice-breeding species, which in turn facilitates the development of genetic differentiation between subpopulations. Other aspects of life history such as geographically distinct vocalizations, female gregariousness, and the potential for polygynous breeding may also facilitate population structure. Based on these factors, we predicted that fast-ice-breeding seal species (the Weddell and ringed seal) would show elevated genetic differentiation compared to pack-ice-breeding species (the leopard, Ross, crabeater and bearded seals). We tested this prediction using microsatellite analysis to examine population structure of these six ice-breeding species. Our results did not support this prediction. While none of the Antarctic pack-ice species showed statistically significant population structure, the bearded seal of the Arctic pack ice showed strong differentiation between subpopulations. Again in contrast, the fast-ice-breeding Weddell seal of the Antarctic showed clear evidence for genetic differentiation while the ringed seal, breeding in similar habitat in the Arctic, did not. These results suggest that the development of population structure in ice-breeding phocid seals is a more complex outcome of the interplay of phylogenetic and ecological factors than can be predicted on the basis of breeding substrate and life-history characteristics.

  15. Same size--same niche? Foraging niche separation between sympatric juvenile Galapagos sea lions and adult Galapagos fur seals.

    PubMed

    Jeglinski, Jana W E; Goetz, Kimberley T; Werner, Christiane; Costa, Daniel P; Trillmich, Fritz

    2013-05-01

    1. In vertebrates, patterns of resource utilization change throughout development according to age- and or size-specific abilities and requirements. Thus, interspecific competition affects different age classes differently. 2. Adults of sympatric species often show distinct foraging niche segregation, but juvenile resource use might overlap with adult competitors of similar body size. Resultant negative effects on juveniles can have important consequences for population dynamics, yet such interactions have received little attention in studies of mammalian communities. 3. Using GPS tracking devices, time-depth recorders and stable isotope data, we compared diving depth, activity time, trophic position and foraging habitat characteristics to investigate foraging niche overlap between similar-sized sympatric juvenile Galapagos sea lions (Zalophus wollebaeki) and adult Galapagos fur seals (Arctocephalus galapagoensis) and compared each group with much larger-bodied adult Galapagos sea lions. 4. We found little indication for direct competition but a complex pattern of foraging niche segregation: juvenile sea lions and adult fur seals dived to shallow depths at night, but foraged in different habitats with limited spatial overlap. Conversely, juvenile and adult sea lions employed different foraging patterns, but their foraging areas overlapped almost completely. 5. Consistency of foraging habitat characteristics between juvenile and adult sea lions suggests that avoidance of competition may be important in shaping foraging habitat utilization. Resultant specialization on a limited habitat could contribute to low sea lion numbers that contrast with high fur seal abundance. Our data suggest that exploitation by multiple predators within spatially restricted foraging ranges of juveniles might negatively impact juvenile foraging success and ultimately influence population dynamics.

  16. Seals and Sealing Techniques

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Developments by the aerospace industry in seals and sealing techniques are announced for possible use in other areas. The announcements presented are grouped as: sealing techniques for cryogenic fluids, high pressure applications, and modification for improved performance.

  17. 76 FR 43266 - Marine Mammals; File No. 16472

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-20

    ...), leopard seals (Hydrurga leptonyx), Ross seals (Ommatophoca rossii), and Weddell seals (Leptonychotes... pups; 50 leopard seal adults and juveniles; 50 southern elephant seal adults and juveniles; 100... leopard seals, 200 Weddell seals, and 5 Ross seals would be taken annually by harassment during aerial...

  18. Click-evoked potentials in a large marine mammal, the adult male northern elephant seal (Mirounga angustirostris).

    PubMed

    Houser, Dorian S; Crocker, Daniel E; Finneran, James J

    2008-07-01

    Auditory evoked potential (AEP) hearing studies in marine mammals should consider an expected size-dependent reduction in AEP amplitude. This study is the first to measure the click-evoked response in a large marine mammal, the adult male elephant seal (Mirounga angustirostris). Click stimuli were presented at peak-peak equivalent sound pressure levels of 117-118 dB re: 20 microPa. Three positive peaks (P1-P3) and two negative peaks (N4 and N5) were observed in the AEP. Response latencies were longer than previously observed in a 1.8 yr old seal and the maximum peak-peak amplitude was comparatively reduced by more than 60%. The inverse relationship between size and AEP amplitude will likely require increased averaging with larger subjects and possibly modifications to electrode placement and design in order to increase the quality of recorded evoked responses.

  19. Pre-partum diet of adult female bearded seals in years of contrasting ice conditions.

    PubMed

    Hindell, Mark A; Lydersen, Christian; Hop, Haakon; Kovacs, Kit M

    2012-01-01

    Changing patterns of sea-ice distribution and extent have measurable effects on polar marine systems. Beyond the obvious impacts of key-habitat loss, it is unclear how such changes will influence ice-associated marine mammals in part because of the logistical difficulties of studying foraging behaviour or other aspects of the ecology of large, mobile animals at sea during the polar winter. This study investigated the diet of pregnant bearded seals (Erignathus barbatus) during three spring breeding periods (2005, 2006 and 2007) with markedly contrasting ice conditions in Svalbard using stable isotopes (δ(13)C and δ(15)N) measured in whiskers collected from their newborn pups. The δ(15)N values in the whiskers of individual seals ranged from 11.95 to 17.45 ‰, spanning almost 2 full trophic levels. Some seals were clearly dietary specialists, despite the species being characterised overall as a generalist predator. This may buffer bearded seal populations from the changes in prey distributions lower in the marine food web which seems to accompany continued changes in temperature and ice cover. Comparisons with isotopic signatures of known prey, suggested that benthic gastropods and decapods were the most common prey. Bayesian isotopic mixing models indicated that diet varied considerably among years. In the year with most fast-ice (2005), the seals had the greatest proportion of pelagic fish and lowest benthic invertebrate content, and during the year with the least ice (2006), the seals ate more benthic invertebrates and less pelagic fish. This suggests that the seals fed further offshore in years with greater ice cover, but moved in to the fjords when ice-cover was minimal, giving them access to different types of prey. Long-term trends of sea ice decline, earlier ice melt, and increased water temperatures in the Arctic are likely to have ecosystem-wide effects, including impacts on the forage bases of pagophilic seals.

  20. Pre-Partum Diet of Adult Female Bearded Seals in Years of Contrasting Ice Conditions

    PubMed Central

    Hindell, Mark A.; Lydersen, Christian; Hop, Haakon; Kovacs, Kit M.

    2012-01-01

    Changing patterns of sea-ice distribution and extent have measurable effects on polar marine systems. Beyond the obvious impacts of key-habitat loss, it is unclear how such changes will influence ice-associated marine mammals in part because of the logistical difficulties of studying foraging behaviour or other aspects of the ecology of large, mobile animals at sea during the polar winter. This study investigated the diet of pregnant bearded seals (Erignathus barbatus) during three spring breeding periods (2005, 2006 and 2007) with markedly contrasting ice conditions in Svalbard using stable isotopes (δ13C and δ15N) measured in whiskers collected from their newborn pups. The δ15N values in the whiskers of individual seals ranged from 11.95 to 17.45 ‰, spanning almost 2 full trophic levels. Some seals were clearly dietary specialists, despite the species being characterised overall as a generalist predator. This may buffer bearded seal populations from the changes in prey distributions lower in the marine food web which seems to accompany continued changes in temperature and ice cover. Comparisons with isotopic signatures of known prey, suggested that benthic gastropods and decapods were the most common prey. Bayesian isotopic mixing models indicated that diet varied considerably among years. In the year with most fast-ice (2005), the seals had the greatest proportion of pelagic fish and lowest benthic invertebrate content, and during the year with the least ice (2006), the seals ate more benthic invertebrates and less pelagic fish. This suggests that the seals fed further offshore in years with greater ice cover, but moved in to the fjords when ice-cover was minimal, giving them access to different types of prey. Long-term trends of sea ice decline, earlier ice melt, and increased water temperatures in the Arctic are likely to have ecosystem-wide effects, including impacts on the forage bases of pagophilic seals. PMID:22693616

  1. High-density lipoprotein remains elevated despite reductions in total cholesterol in fasting adult male elephant seals (Mirounga angustirostris).

    PubMed

    Tift, Michael S; Houser, Dorian S; Crocker, Daniel E

    2011-08-01

    We examined changes in lipid profiles of 40 adult northern elephant seal bulls over the 3-month breeding fast and the 1-month molting fast to investigate impacts of fasting on serum total cholesterol (TC), triglycerides (TG) and lipoproteins. Total cholesterol and low-density lipoprotein (LDL) levels were initially high (3930 ± 190mgL(-1)and 1610 ± 170mgL(-1), respectively) and decreased significantly over the breeding season. Total cholesterol and LDL declined significantly with adipose tissue reserves (p<0.001), and LDL levels as low as 43 mgL(-1) were measured in seals late in the breeding fast. Less dramatic but similar changes in lipid metabolism were observed across the molting fast. High-density lipoproteins (HDL) remained consistently elevated (>1750 mgL(-1)) suggesting that elephant seals defend HDL concentrations, despite significant depletion of TC and LDL across the breeding fast. Triglyceride levels were significantly higher during the molt, consistent with lower rates of lipid oxidation needed to meet metabolic energy demands during this period. The maintenance of HDL during breeding is consistent with its role in delivering cholesterol from adipose tissue for steroidogenesis and spermatogenesis and potentially mitigates oxidative stress associated with fasting.

  2. The Weddell sea anomaly observed with the Topex satellite data

    NASA Astrophysics Data System (ADS)

    Horvath, I.; Essex, E. A.

    2003-04-01

    This paper introduces the complete image of the Weddell Sea Anomaly, observed with the over-the-ocean ionospheric total electron content (TEC) values obtained from the TOPEX satellite data with an almost unlimited coverage over the oceans, the first time according to the literature; and investigates its development. With a series of TOPEX TEC maps, this paper demonstrates the diurnal variations of both the night-time and the day-time Weddell Sea Anomaly, which appeared as a night-time TEC enhancement and as a day-time TEC depletion, during the near sunspot maximum period of 1998 and 1999 investigated. Several TOPEX passes, plotted in geomagnetic latitudes, are also presented to demonstrate the longitudinal variations of the Weddell Sea Anomaly, and also to show other ionospheric features appearing such as the southern-hemisphere mid-latitude day-time and night-time trough, the northern-hemisphere mid-latitude night-time trough and the equatorial anomaly. This paper demonstrates how large the anomaly is in reality situated west of the Faraday ionosonde station over the Bellinghausen Sea and not over the Weddell Sea that is east of Faraday. Thus the correct name should be Bellinghausen Sea Anomaly. Based upon the review paper of Dudeney and Piggott (1978), the development of the Weddell Sea Anomaly is explained with the combined effects of solar ultraviolet radiation and thermospheric neutral winds.

  3. Effects of environmental variables on surface temperature of breeding adult female northern elephant seals, Mirounga angustirostris, and pups.

    PubMed

    Codde, Sarah A; Allen, Sarah G; Houser, Dorian S; Crocker, Daniel E

    2016-10-01

    Pinnipeds spend extended periods of time on shore during breeding, and some temperate species retreat to the water if exposed to high ambient temperatures. However, female northern elephant seals (Mirounga angustirostris) with pups generally avoid the water, presumably to minimize risks to pups or male harassment. Little is known about how ambient temperature affects thermoregulation of well insulated females while on shore. We used a thermographic camera to measure surface temperature (Ts) of 100 adult female elephant seals and their pups during the breeding season at Point Reyes National Seashore, yielding 782 thermograms. Environmental variables were measured by an onsite weather station. Environmental variables, especially solar radiation and ambient temperature, were the main determinants of mean and maximum Ts of both females and pups. An average of 16% of the visible surface of both females and pups was used as thermal windows to facilitate heat loss and, for pups, this area increased with solar radiation. Thermal window area of females increased with mean Ts until approximately 26°C and then declined. The Ts of both age classes were warmer than ambient temperature and had a large thermal gradient with the environment (female mean 11.2±0.2°C; pup mean 14.2±0.2°C). This large gradient suggests that circulatory adjustments to bypass blubber layers were sufficient to allow seals to dissipate heat under most environmental conditions. We observed the previously undescribed behavior of females and pups in the water and determined that solar radiation affected this behavior. This may have been possible due to the calm waters at the study site, which reduced the risk of neonates drowning. These results may predict important breeding habitat features for elephant seals as solar radiation and ambient temperatures change in response to changing climate.

  4. Westward flow of Weddell Sea Bottom Water through Drake Passage

    NASA Astrophysics Data System (ADS)

    Gebler, M.; Huhn, O.; Rhein, M.

    2009-04-01

    During the Polarstern cruise ANT XXIII-3 (2006) an enlarged chlorofluorocarbon (CFC) signal was found in the southern part of Drake Passage indicating the presence of recently ventilated water, presumably Weddell Sea Bottom Water (WSBW) originating from the western Weddell Sea. This WSBW leaves the Weddell Basin through gaps in the South Scotia Ridge and spreads westward along the continental slope. It reaches the 2006 section and is probably stopped by Shackleton Fracture Zone. By applying an Optimum Multiparameter Analysis (OMP) using temperature, salinity, oxygen, silicate, nitrate and δHe3 we determine the fractions of WSBW in the Drake Passage Section. The CFC age derived from the WSBW fractions indicates that there must be an additional CFC source, because the observed concentrations are higher than can be explained by the WSBW.

  5. Space Radar Image of Weddell Sea, Antarctica

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar color composite shows a portion of the Weddell Sea, which is adjacent to the continent of Antarctica. The image shows extensive coverage of first-year sea ice mixtures and patches of open water inside the ice margin. The image covers a 100 kilometer by 30 kilometer (62 mile by 18.5 mile) region of the southern ocean, centered at approximately 57 degrees south latitude and 3 degrees east longitude, which was acquired on October 3, 1994. Data used to create this image were obtained using the L-band (horizontally transmitted and vertically received) in red; the L-band (horizontally transmitted and received) in green; and the C-band (horizontally transmitted and received) in blue. The sea ice, which appears rust-brown in the image, is composed of loosely packed floes from approximately 1 meter to 2 meters (3 feet to 6.5 feet) thick and ranging from 1 meter to 20 meters (3 feet to 65.5 feet) in diameter. Large patches of open water, shown as turquoise blue, are scattered throughout the area, which is typical for ice margins experiencing off-ice winds. The thin, well-organized lines clearly visible in the ice pack are caused by radar energy reflected by floes riding the crest of ocean swells. The wispy, black features seen throughout the image represent areas where new ice is forming. Sea ice, because it acts as an insulator, reduces the loss of heat between the relatively warm ocean and cold atmosphere. This interaction is an important component of the global climate system. Because of the unique combination of winds, currents and temperatures found in this region, ice can extend many hundreds of kilometers north of Antarctica each winter, which classifies the Weddell Sea as one of nature's greatest ice-making engines. During the formation of sea ice, great quantities of salt are expelled from the frozen water. The salt increases the density of the upper layer of sea water, which then sinks to great depths

  6. Space Radar Image of Weddell Sea

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Two radar images are shown in this composite to compare the size of a standard spaceborne radar image (small inset) to the image that is created when the radar instrument is used in the ScanSAR mode (large image). The predominant image shows two large ocean circulation features, called eddies, at the northernmost edge of the sea ice pack in the Weddell Sea, off Antarctica. The eddy processes in this region play an important role in the circulation of the global ocean and the transportation of heat toward the pole. The large image is the first wide-swath, multi-frequency, multi-polarization radar image ever processed. To date, no other spaceborne radar sensors have obtained swaths exceeding 100 kilometers (62 miles) in width. This developmental image was produced at NASA's Jet Propulsion Laboratory by the Alaska SAR Facility's ScanSAR processor system, using radar data obtained on October 5, 1994, during the second flight of the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour. The image is oriented approximately east-west, with a center location of around 56.6 degrees south latitude and 6.5 degrees west longitude. Image dimensions are 240 km by 350 km (149 miles by 218 miles). The smaller image inset (upper right edge) was obtained by SIR-C/X-SAR on October 6, 1994, and covers a portion of the same ice features that are shown in the large image. The inset image dimensions are 18 km by 50 km (11 miles by 31 miles). The ocean eddies have a clockwise (or cyclonic) rotation and are roughly 40 km to 60 km (25 miles to 37 miles) in diameter. The dark areas are new ice and the lighter green areas are small sea-ice floes that are swept along by surface currents; both of these areas are shown within the eddies and to the south of the eddies. First year seasonal ice, typically 0.5 meter to 0.8 meter (1.5 feet to 2.5 feet) thick, is shown in the darker green area in the lower right corner. The open ocean to the north

  7. Space Radar Image of Weddell Sea Ice

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is the first calibrated, multi-frequency, multi-polarization spaceborne radar image of the seasonal sea-ice cover in the Weddell Sea, Antarctica. The multi-channel data provide scientists with details about the ice pack they cannot see any other way and indicates that the large expanse of sea-ice is, in fact, comprised of many smaller rounded ice floes, shown in blue-gray. These data are particularly useful in helping scientists estimate the thickness of the ice cover which is often extremely difficult to measure with other remote sensing systems. The extent, and especially thickness, of the polar ocean's sea-ice cover together have important implications for global climate by regulating the loss of heat from the ocean to the cold polar atmosphere. The image was acquired on October 3, 1994, by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour. This image is produced by overlaying three channels of radar data in the following colors: red (C-band, HH-polarization), green (L-band HV-polarization), and blue (L-band, HH-polarization). The image is oriented almost east-west with a center location of 58.2 degrees South and 21.6 degrees East. Image dimensions are 45 kilometers by 18 kilometers (28 miles by 11 miles). Most of the ice cover is composed of rounded, undeformed blue-gray floes, about 0.7 meters (2 feet) thick, which are surrounded by a jumble of red-tinged deformed ice pieces which are up to 2 meters (7 feet) thick. The winter cycle of ice growth and deformation often causes this ice cover to split apart, exposing open water or 'leads'. Ice growth within these openings is rapid due to the cold, brisk Antarctic atmosphere. Different stages of new-ice growth can be seen within the linear leads, resulting from continuous opening and closing. The blue lines within the leads are open water areas in new fractures which are roughened by wind. The bright red lines are an intermediate stage of new

  8. Seal Lungs Collapse during Free Diving: Evidence from Arterial Nitrogen Tensions

    NASA Astrophysics Data System (ADS)

    Falke, Konrad J.; Hill, Roger D.; Qvist, Jesper; Schneider, Robert C.; Guppy, Michael; Liggins, Graham C.; Hochachka, Peter W.; Elliott, Richard E.; Zapol, Warren M.

    1985-08-01

    Arterial blood nitrogen tensions of free-diving Weddell seals (Leptonychotes weddelli) were measured by attaching a microprocessor-controlled blood pump and drawing samples at depth to determine how these marine mammals dive to great depths and ascend rapidly without developing decompression sickness. Forty-seven samples of arterial blood were obtained from four Weddell seals during free dives lasting up to 23 minutes to depths of 230 meters beneath the sea ice of McMurdo Sound, Antarctica. Peak arterial blood nitrogen tensions of between 2000 and 2500 millimeters of mercury were recorded at depths of 40 to 80 meters during descent, indicating that the seal's lung collapses by 25 to 50 meters. Then arterial blood nitrogen tensions slowly decreased to about 1500 millimeters of mercury at the surface. In a single dive, alveolar collapse and redistribution of blood nitrogen allow the seal to avoid nitrogen narcosis and decompression sickness.

  9. Acoustic seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  10. Acoustic Seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  11. Iceberg Drift In The Eastern Weddell Sea: Observed And Modeled

    NASA Astrophysics Data System (ADS)

    Wesche, Christine; Rackow, Thomas; Dierking, Wolfgang

    2013-12-01

    The eastern Weddell Sea region is an alley for drifting icebergs, which calve further east along the coastline of East Antarctica. Our analysis is focused on the region north of the Ekstro ̈m Ice Shelf. Since at the Ekstro ̈m Ice Shelf a landing place is used for the supply of the German overwintering station Neumayer III and the South-African station Sanae IV, it is important to monitor the drifting routes taken by the icebergs in this region. We use a series of ENVISAT ASAR WSM data to follow a larger (D18) and a smaller (IB1) iceberg through the eastern Weddell Sea region in 2006. Model simulations are carried out to get more detailed information about the relative influence of different forces on the iceberg drift in this region.

  12. Passive microwave in situ observations of winter Weddell Sea ice

    NASA Technical Reports Server (NTRS)

    Comiso, J. C.; Grenfell, T. C.; Bell, D. L.; Lange, M. A.; Ackley, S. F.

    1989-01-01

    Results are presented on the microwave radiative characteristics of Antarctic sea ice measured during the 1986 Winter Weddell Sea Project with a set of portable radiometers. Radiometer measurements at 6, 10, 18, 37, and 90 GHz in vertical and horizontal polarizations were supplemented by near-simultaneous measurements of the ice physical characteristics (including ice thickness, salinity, temperature, snow cover, and density) made during two cruises, lasting 3 months each. Measurements were obtained on various types of sea ice over a large portion of the Weddell-Sea ice cover, including four transects across the entire ice pack. Data analysis shows a large variability in the multispectral microwave emissivities of different ice types, especially at 90 GHz, demonstrating a strong potential of the use of the 90-GHz channel, in combination with lower-frequency channels, for detailed characterizations of the ice cover.

  13. Wind-driven export of Weddell Sea slope water

    NASA Astrophysics Data System (ADS)

    Meijers, A. J. S.; Meredith, M. P.; Abrahamsen, E. P.; Morales Maqueda, M. A.; Jones, D. C.; Naveira Garabato, A. C.

    2016-10-01

    The export of waters from the Weddell Gyre to lower latitudes is an integral component of the southern subpolar contribution to the three-dimensional oceanic circulation. Here we use more than 20 years of repeat hydrographic data on the continental slope on the northern tip of the Antarctic Peninsula and 5 years of bottom lander data on the slope at 1000 m to show the intermittent presence of a relatively cold, fresh, westward flowing current. This is often bottom-intensified between 600 and 2000 dbar with velocities of over 20 cm s-1, transporting an average of 1.5 ± 1.5 Sv. By comparison with hydrography on the continental slope within the Weddell Sea and modeled tracer release experiments we show that this slope current is an extension of the Antarctic Slope Current that has crossed the South Scotia Ridge west of Orkney Plateau. On monthly to interannual time scales the density of the slope current is negatively correlated (r > 0.6 with a significance of over 95%) with eastward wind stress over the northern Weddell Sea, but lagging it by 6-13 months. This relationship holds in both the high temporal resolution bottom lander time series and the 20+ year annual hydrographic occupations and agrees with Weddell Sea export variability observed further east. We compare several alternative hypotheses for this wind stress/export relationship and find that it is most consistent with wind-driven acceleration of the gyre boundary current, possibly modulated by eddy dynamics, and represents a mechanism by which climatic perturbations can be rapidly transmitted as fluctuations in the supply of intermediate-level waters to lower latitudes.

  14. Deep-sea Hexactinellida (Porifera) of the Weddell Sea

    NASA Astrophysics Data System (ADS)

    Janussen, Dorte; Tabachnick, Konstantin R.; Tendal, Ole S.

    2004-07-01

    New Hexactinellida from the deep Weddel Sea are described. This moderately diverse hexactinellid fauna includes 14 species belonging to 12 genera, of which five species and one subgenus are new to science: Periphragella antarctica n. sp., Holascus pseudostellatus n. sp., Caulophacus (Caulophacus) discohexactinus n. sp., C. ( Caulodiscus) brandti n. sp., C. ( Oxydiscus) weddelli n. sp., and C. ( Oxydiscus) n. subgen. So far, 20 hexactinellid species have been reported from the deep Weddell Sea, 15 are known from the northern part and 10 only from here, while 10 came from the southern area, and five of these only from there. However, this apparent high "endemism" of Antarctic hexactinellid sponges is most likely the result of severe undersampling of the deep-sea fauna. We find no reason to believe that a division between an oceanic and a more continental group of species exists. The current poor database indicates that a substantial part of the deep hexactinellid fauna of the Weddell Sea is shared with other deep-sea regions, but it does not indicate a special biogeographic relationship with any other ocean.

  15. Simulation of Coastal Polynyas in the Western Weddell Sea

    NASA Astrophysics Data System (ADS)

    Haid, Verena; Timmermann, Ralph

    2010-05-01

    Coastal polynyas play a prominent role in the formation and modification of water masses in the polar oceans. A coastal polynya is usually kept open mechanically, primarily by winds, and the ocean surface is at freezing point. Thus a major fraction of the annual ice production of the high-latitude oceans occurs in polynyas and hence the duration and extent of their appearance has a substantial effect on bottom water formation. In the western Weddell Sea, recurring coastal polynyas are formed in front of the Filchner-Ronne Ice Shelf and in the area of the decayed Larsen A/B Ice Shelf. Simulations to study polynya formation and their impact on ice production and bottom water formation in the western Weddell Sea were performed with the Finite Element Sea ice-Ocean Model (FESOM) of Alfred-Wegener-Institute (AWI). FESOM is a fully coupled system of a primitive-equation, hydrostatic ocean model and a dynamic-thermodynamic sea ice model. The simulations were conducted on a global grid with a resolution varying between roughly 300 km in tropical latitudes and <5 km along the coast of the southwestern Weddell Sea. In vertical direction, the grid uses terrain-following coordinates. The model results give insight into the mechanisms governing the formation of transient and persistent polynyas and their influence on ice production and deep water formation. Water mass formation and ice export rates are quantified and compared to observation-based estimates.

  16. Foraging habitats of southern elephant seals, Mirounga leonina, from the Northern Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Muelbert, Monica M. C.; de Souza, Ronald B.; Lewis, Mirtha N.; Hindell, Mark A.

    2013-04-01

    Elephant Island (EI) is uniquely placed to provide southern elephant seals (SES) breeding there with potential access to foraging grounds in the Weddell Sea, the frontal zones of the South Atlantic Ocean, the Patagonian shelf and the Western Antarctic Peninsula (WAP). Quantifying where seals from EI forage therefore provides insights into the types of important habitats available, and which are of particular importance to elephant seals. Twenty nine SES (5 sub-adult males—SAM and 24 adult females—AF) were equipped with SMRU CTD-SLDRs during the post-breeding (PB 2008, 2009) and post-moulting (PM 2007, 2008, 2009, 2010) trips to sea. There were striking intra-annual and inter-sex differences in foraging areas, with most of the PB females remaining within 150 km of EI. One PB AF travelled down the WAP as did 16 out of the 20 PM females and foraged near the winter ice-edge. Most PM sub-adult males remained close to EI, in areas similar to those used by adult females several months earlier, although one SAM spent the early part of the winter foraging on the Patagonian Shelf. The waters of the Northern Antarctic Peninsula (NAP) contain abundant resources to support the majority of the Islands' SES for the summer and early winter, such that the animals from this population have shorter migrations than those from most other populations. Sub-adult males and PB females are certainly taking advantage of these resources. However, PM females did not remain there over the winter months, instead they used the same waters at the ice-edge in the southern WAP that females from both King George Island and South Georgia used. Females made more benthic dives than sub-adult males—again this contrasts with other sites where SAMs do more benthic diving. Unlike most other populations studied to date EI is a relatively southerly breeding colony located on the Antarctic continental shelf. EI seals are using shelf habitats more than other SES populations but some individuals still

  17. Fortuitous encounters between seagliders and adult female northern fur seals (Callorhinus ursinus) off the Washington (USA) coast: upper ocean variability and links to top predator behavior.

    PubMed

    Pelland, Noel A; Sterling, Jeremy T; Lea, Mary-Anne; Bond, Nicholas A; Ream, Rolf R; Lee, Craig M; Eriksen, Charles C

    2014-01-01

    Behavioral responses by top marine predators to oceanographic features such as eddies, river plumes, storms, and coastal topography suggest that biophysical interactions in these zones affect predators' prey, foraging behaviors, and potentially fitness. However, examining these pathways is challenged by the obstacles inherent in obtaining simultaneous observations of surface and subsurface environmental fields and predator behavior. In this study, migratory movements and, in some cases, diving behavior of 40 adult female northern fur seals (NFS; Callorhinus ursinus) were quantified across their range and compared to remotely-sensed environmental data in the Gulf of Alaska and California Current ecosystems, with a particular focus off the coast of Washington State (USA)--a known foraging ground for adult female NFS and where autonomous glider sampling allowed opportunistic comparison of seal behavior to subsurface biophysical measurements. The results show that in these ecosystems, adult female habitat utilization was concentrated near prominent coastal topographic, riverine, or inlet features and within 200 km of the continental shelf break. Seal dive depths, in most ecosystems, were moderated by surface light level (solar or lunar), mirroring known behaviors of diel vertically-migrating prey. However, seal dives differed in the California Current ecosystem due to a shift to more daytime diving concentrated at or below the surface mixed layer base. Seal movement models indicate behavioral responses to season, ecosystem, and surface wind speeds; individuals also responded to mesoscale eddies, jets, and the Columbia River plume. Foraging within small scale surface features is consistent with utilization of the inner coastal transition zone and habitats near coastal capes, which are known eddy and filament generation sites. These results contribute to our knowledge of NFS migratory patterns by demonstrating surface and subsurface behavioral responses to a spatially

  18. Fortuitous Encounters between Seagliders and Adult Female Northern Fur Seals (Callorhinus ursinus) off the Washington (USA) Coast: Upper Ocean Variability and Links to Top Predator Behavior

    PubMed Central

    Pelland, Noel A.; Sterling, Jeremy T.; Lea, Mary-Anne; Bond, Nicholas A.; Ream, Rolf R.; Lee, Craig M.; Eriksen, Charles C.

    2014-01-01

    Behavioral responses by top marine predators to oceanographic features such as eddies, river plumes, storms, and coastal topography suggest that biophysical interactions in these zones affect predators' prey, foraging behaviors, and potentially fitness. However, examining these pathways is challenged by the obstacles inherent in obtaining simultaneous observations of surface and subsurface environmental fields and predator behavior. In this study, migratory movements and, in some cases, diving behavior of 40 adult female northern fur seals (NFS; Callorhinus ursinus) were quantified across their range and compared to remotely-sensed environmental data in the Gulf of Alaska and California Current ecosystems, with a particular focus off the coast of Washington State (USA) – a known foraging ground for adult female NFS and where autonomous glider sampling allowed opportunistic comparison of seal behavior to subsurface biophysical measurements. The results show that in these ecosystems, adult female habitat utilization was concentrated near prominent coastal topographic, riverine, or inlet features and within 200 km of the continental shelf break. Seal dive depths, in most ecosystems, were moderated by surface light level (solar or lunar), mirroring known behaviors of diel vertically-migrating prey. However, seal dives differed in the California Current ecosystem due to a shift to more daytime diving concentrated at or below the surface mixed layer base. Seal movement models indicate behavioral responses to season, ecosystem, and surface wind speeds; individuals also responded to mesoscale eddies, jets, and the Columbia River plume. Foraging within small scale surface features is consistent with utilization of the inner coastal transition zone and habitats near coastal capes, which are known eddy and filament generation sites. These results contribute to our knowledge of NFS migratory patterns by demonstrating surface and subsurface behavioral responses to a spatially

  19. Active Microwave Remote Sensing Observations of Weddell Sea Ice

    NASA Technical Reports Server (NTRS)

    Drinkwater, Mark R.

    1997-01-01

    Since July 1991, the European Space Agency's ERS-1 and ERS-2 satellites have acquired radar data of the Weddell Sea, Antarctica. The Active Microwave Instrument on board ERS has two modes; SAR and Scatterometer. Two receiving stations enable direct downlink and recording of high bit-rate, high resolution SAR image data of this region. When not in an imaging mode, when direct SAR downlink is not possible, or when a receiving station is inoperable, the latter mode allows normalized radar cross-section data to be acquired. These low bit-rate ERS scatterometer data are tape recorded, downlinked and processed off-line. Recent advances in image generation from Scatterometer backscatter measurements enable complementary medium-scale resolution images to be made during periods when SAR images cannot be acquired. Together, these combined C-band microwave image data have for the first time enabled uninterrupted night and day coverage of the Weddell Sea region at both high (25 m) and medium-scale (-20 km) resolutions. C-band ERS-1 radar data are analyzed in conjunction with field data from two simultaneous field experiments in 1992. Satellite radar signature data are compared with shipborne radar data to extract a regional and seasonal signature database for recognition of ice types in the images. Performance of automated sea-ice tracking algorithms is tested on Antarctic data to evaluate their success. Examples demonstrate that both winter and summer ice can be effectively tracked. The kinematics of the main ice zones within the Weddell Sea are illustrated, together with the complementary time-dependencies in their radar signatures. Time-series of satellite images are used to illustrate the development of the Weddell Sea ice cover from its austral summer minimum (February) to its winter maximum (September). The combination of time-dependent microwave signatures and ice dynamics tracking enable various drift regimes to be defined which relate closely to the circulation of the

  20. Scanning electron microscopic study on the tongue and lingual papillae of the adult Spotted seal, Phoca largha.

    PubMed

    Yoshimura, Ken; Shindo, Junji; Miyawaki, Yoshiko; Kobayashi, Kan; Kageyama, Ikuo

    2007-11-01

    We observed the external surface and connective tissue cores (CTCs) of the lingual papillae (filiform, fungiform and vallate papillae) of adult Spotted seals (Phoca largha) using SEM and light microscopy. The tongue was V-shaped and its apex was rather rounded. On the dorsal surface from apex to the one-third posterior of the tongue, the lingual mucosa was densely covered by filiform papillae, with a scatted distribution of dome-like fungiform papillae, which have orthokeratinized epithelium. At the posterior part of the tongue, filiform papillae were totally diminished and their epithelium was parakeratinized. Approximately 6-7 vallate papillae were arranged in a V-shape on the posterior of the tongue. After removal of the epithelium, the CTCs of the filiform papillae that were distributed at apex consisted of a primary core and approximately 5-6 rod-shaped small accessory cores. The CTCs of filiform papillae that were distributed at anterior part of the tongue lacked primary protrusions and possessed approximately 10-15 rod shaped small accessory cores that were arranged in a horseshoe manner. The CTCs offungiform papillae had cylindrical primary cores and were fringed with accessory protrusion. In the Vallate papillae, taste buds were only seen at the dorsal epithelium.

  1. Glass sealing

    SciTech Connect

    Brow, R.K.; Kovacic, L.; Chambers, R.S.

    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.

  2. Coining seal

    DOEpatents

    Mancebo, Lloyd

    1976-01-01

    A bakeable high pressure-vacuum seal is provided in which an inductile sealing element having a butterfly shaped crosssection with protruding sharp edges at each of the four corners, is sandwiched between two ductile sealing elements, the sandwiched assembly then being compressed between the surfaces of the flange elements of a high pressure or high vacuum vessel to coin the ductile sealing element into the surface of the inductile sealing element as well as the surfaces of the flange elements.

  3. Sealing device

    SciTech Connect

    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.

  4. Lunar cycles in diel prey migrations exert a stronger effect on the diving of juveniles than adult Galápagos fur seals.

    PubMed

    Horning, M; Trillmich, F

    1999-06-07

    In our study of the development of diving in Galápagos fur seals, we analysed changes in diving activity and body mass trends over the lunar cycle. Based on previously observed lunar cycles in colony attendance patterns, we hypothesized a greater impact of prey migrations of deep scattering layer organisms on younger fur seals. Using electronic dive recorders, we determined that seals dived less and deeper on moonlit nights than at new moon, and incurred body mass losses. These changes in foraging over the lunar cycle correlate with the suppression of the vertical migration of prey by lunar light. All effects were more pronounced in juveniles than adult females, with greater relative mass loss during full moon, which must (i) negatively affect long-term juvenile growth rates, (ii) lengthen periods of maternal dependence, and (iii) contribute to the lowest reproductive rate reported for seals. This underlines the importance of studying ontogeny in order to understand life histories, and for determining the susceptibility of animal populations to fluctuations in food availability.

  5. Metabolic responses to adrenocorticotropic hormone (ACTH) vary with life-history stage in adult male northern elephant seals.

    PubMed

    Ensminger, David C; Somo, Derek A; Houser, Dorian S; Crocker, Daniel E

    2014-08-01

    Strong individual and life-history variation in serum glucocorticoids has been documented in many wildlife species. Less is known about variation in hypothalamic-pituitary-adrenal (HPA) axis responsiveness and its impact on metabolism. We challenged 18 free-ranging adult male northern elephant seals (NES) with an intramuscular injection of slow-release adrenocorticotropic hormone (ACTH) over 3 sample periods: early in the breeding season, after 70+ days of the breeding fast, and during peak molt. Subjects were blood sampled every 30 min for 2h post-injection. Breeding animals were recaptured and sampled at 48 h. In response to the ACTH injection, cortisol increased 4-6-fold in all groups, and remained elevated at 48 h in early breeding subjects. ACTH was a strong secretagogue for aldosterone, causing a 3-8-fold increase in concentration. Cortisol and aldosterone responses did not vary between groups but were correlated within individuals. The ACTH challenge produced elevations in plasma glucose during late breeding and molting, suppressed testosterone and thyroid hormone at 48 h in early breeding, and increased plasma non-esterified fatty acids and ketoacids during molting. These data suggest that sensitivity of the HPA axis is maintained but the metabolic impacts of cortisol and feedback inhibition of the axis vary with life history stage. Strong impacts on testosterone and thyroid hormone suggest the importance of maintaining low cortisol levels during the breeding fast. These data suggest that metabolic adaptations to extended fasting in NES include alterations in tissue responses to hormones that mitigate deleterious impacts of acute or moderately sustained stress responses.

  6. Observations of energetic turbulence on the Weddell Sea continental slope

    NASA Astrophysics Data System (ADS)

    Fer, Ilker; Darelius, Elin; Daae, Kjersti B.

    2016-01-01

    Turbulence profile measurements made on the upper continental slope and shelf of the southeastern Weddell Sea reveal striking contrasts in dissipation and mixing rates between the two sites. The mean profiles of dissipation rates from the upper slope are 1-2 orders of magnitude greater than the profiles collected over the shelf in the entire water column. The difference increases toward the bottom where the dissipation rate of turbulent kinetic energy and the vertical eddy diffusivity on the slope exceed 10-7 W kg-1 and 10-2 m2 s-1, respectively. Elevated levels of turbulence on the slope are concentrated within a 100 m thick bottom layer, which is absent on the shelf. The upper slope is characterized by near-critical slopes and is in close proximity to the critical latitude for semidiurnal internal tides. Our observations suggest that the upper continental slope of the southern Weddell Sea is a generation site of semidiurnal internal tide, which is trapped along the slope along the critical latitude, and dissipates its energy in a m thick layer near the bottom and within km across the slope.

  7. East Weddell Sea echinoids from the JR275 expedition

    PubMed Central

    Saucède, Thomas; Griffiths, Huw; Moreau, Camille; Jackson, Jennifer A.; Sands, Chester; Downey, Rachel; Reed, Adam; Mackenzie, Melanie; Geissler, Paul; Linse, Katrin

    2015-01-01

    Abstract Information regarding the echinoids in this dataset is based on the Agassiz Trawl (AGT) and epibenthic sledge (EBS) samples collected during the British Antarctic Survey cruise JR275 on the RRS James Clark Ross in the austral summer 2012. A total of 56 (1 at the South Orkneys and 55 in the Eastern Weddell Sea) Agassiz Trawl and 18 (2 at the South Orkneys and 16 in the Eastern Weddell Sea) epibenthic sledge deployments were performed at depths ranging from ~280 to ~2060 m. This presents a unique collection for the Antarctic benthic biodiversity assessment of an important group of benthic invertebrates. In total 487 specimens belonging to six families, 15 genera, and 22 morphospecies were collected. The species richness per station varied between one and six. Total species richness represents 27% of the 82 echinoid species ever recorded in the Southern Ocean (David et al. 2005b, Pierrat et al. 2012, Saucède et al. 2014). The Cidaridae (sub-family Ctenocidarinae) and Schizasteridae are the two most speciose families in the dataset. They comprise seven and nine species respectively. This is illustrative of the overall pattern of echinoid diversity in the Southern Ocean where 65% of Antarctic species belong to the families Schizasteridae and Cidaridae (Pierrat et al. 2012). PMID:26019674

  8. Security seal

    DOEpatents

    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.

  9. Radiocarbon in the Weddell Sea as observed in a deep-sea coral and in krill

    SciTech Connect

    Michel, R.L.; Druffel, E.M.

    1983-03-01

    Radiocarbon mesurements were performed on krill and coral samples collected from the Weddell Sea during IWSOE '80. These are the first radiocarbon measurements available from this area since 1973. These data reveal carbon-14 levels for Weddell surface water and southern Weddell Shelf water. These data indicate that the radiocarbon levels in surface waters in 1980 were the same or slightly lower than those present in 1973. In addition, an unusually low ..delta../sup 14/C value for shelf water (from coral) at 500 m is evidence that Warm Deep Water (WDW) may penetrate much further and more frequently onto the shelf region than had previously been expected.

  10. Seal assembly

    DOEpatents

    Johnson, Roger Neal; Longfritz, William David

    2001-01-01

    A seal assembly that seals a gap formed by a groove comprises a seal body, a biasing element, and a connection that connects the seal body to the biasing element to form the seal assembly. The seal assembly further comprises a concave-shaped center section and convex-shaped contact portions at each end of the seal body. The biasing element is formed from an elastic material and comprises a convex-shaped center section and concave-shaped biasing zones that are opposed to the convex-shaped contact portions. The biasing element is adapted to be compressed to change a width of the seal assembly from a first width to a second width that is smaller than the first width. In the compressed state, the seal assembly can be disposed in the groove. After release of the compressing force, the seal assembly expands. The contact portions will move toward a surface of the groove and the biasing zones will move into contact with another surface of the groove. The biasing zones will bias the contact portions of the seal body against the surface of the groove.

  11. Atmospheric Response to Weddell Sea Open-Ocean Polynya

    SciTech Connect

    Hodos, Travis; Weijer, Wilbert

    2015-07-02

    The atmospheric conditions associated with the rare Weddell Sea open ocean polynya are investigated. The polynya has not been seen since 1976, so data on the event is scarce. The CESM high resolution model is used to investigate multiple atmospheric variables. We analyze three years of polynyas, which are also compared to three years without a polynya. The surface temperature, sensible heat flux, latent heat flux, humidity, average wind speed, precipitation, longwave flux, and shortwave flux all increased over the polynya. The sensible heat flux had a higher magnitude than the latent heat flux because conduction and convection were the primary drivers of heat flux. A combination of increased latent heat flux and humidity led to an increase in precipitation. Increased longwave downwelling flux over the polynya indicated the presence of clouds over the polynya. Lastly, the sea level pressure was consistently lower over the polynya because of the presence of a thermal low generated by thermally driven convective updrafts.

  12. Combined Satellite - and ULS-Derived Sea-Ice Flux in the Weddell Sea

    NASA Technical Reports Server (NTRS)

    Drinkwater, M.; Liu, X.; Harms, S.

    2000-01-01

    Several years of daily microwave satellite ice-drift are combined with moored Upward Looking Sonar (ULS) ice-drafts into an ice volume flux record at points along a flux gate across the Weddell Sea, Antarctica.

  13. A geomorphological seabed classification for the Weddell Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Jerosch, Kerstin; Kuhn, Gerhard; Krajnik, Ingo; Scharf, Frauke Katharina; Dorschel, Boris

    2016-06-01

    Sea floor morphology plays an important role in many scientific disciplines such as ecology, hydrology and sedimentology since geomorphic features can act as physical controls for e.g. species distribution, oceanographically flow-path estimations or sedimentation processes. In this study, we provide a terrain analysis of the Weddell Sea based on the 500 m × 500 m resolution bathymetry data provided by the mapping project IBCSO. Seventeen seabed classes are recognized at the sea floor based on a fine and broad scale Benthic Positioning Index calculation highlighting the diversity of the glacially carved shelf. Beside the morphology, slope, aspect, terrain rugosity and hillshade were calculated and supplied to the data archive PANGAEA. Applying zonal statistics to the geomorphic features identified unambiguously the shelf edge of the Weddell Sea with a width of 45-70 km and a mean depth of about 1200 m ranging from 270 m to 4300 m. A complex morphology of troughs, flat ridges, pinnacles, steep slopes, seamounts, outcrops, and narrow ridges, structures with approx. 5-7 km width, build an approx. 40-70 km long swath along the shelf edge. The study shows where scarps and depressions control the connection between shelf and abyssal and where high and low declination within the scarps e.g. occur. For evaluation purpose, 428 grain size samples were added to the seabed class map. The mean values of mud, sand and gravel of those samples falling into a single seabed class was calculated, respectively, and assigned to a sediment texture class according to a common sediment classification scheme.

  14. Eddy overturning of the Antarctic Slope Front controls glacial melting in the Eastern Weddell Sea

    NASA Astrophysics Data System (ADS)

    NøSt, O. A.; Biuw, M.; Tverberg, V.; Lydersen, C.; Hattermann, T.; Zhou, Q.; Smedsrud, L. H.; Kovacs, K. M.

    2011-11-01

    The Eastern Weddell Sea is characterized by narrow continental shelves and Warm Deep Water (WDW) is located in close proximity to the ice shelves in this region. The exchange of WDW across the Antarctic Slope Front (ASF) determines the rate of basal ice shelf melting. Here, we present a unique data set consisting of 2351 vertical profiles of temperature and salinity collected by southern elephant seals (Mirounga leonina) and a profile beneath the Fimbul Ice Shelf (FIS), obtained via drilling through 395 m of ice. This data set reveals variations in salinity and temperature through winter, and using a conceptual model of the coastal salt budget we quantify the main exchange processes. Our data show that modified WDW, with temperatures below -1.5°C, is advected onto the shelf and into the ice shelf cavities by an eddy overturning of the ASF. The onshore Ekman flux of surface waters during summer is the main source of freshwater that leads to the formation of low salinity shelf waters in the region. The modified WDW that reaches beneath the ice shelves is too cold for basal ice shelf melting to create such low salinity water. A high-resolution model of an idealized ASF-continental shelf-ice shelf system supports the conclusions from the data analysis. The inflow of WDW onto the continental shelf and into the ice shelf cavity occurs within a bottom boundary layer where the eddy advection in the model is particularly strong, in close agreement with the observed vertical profile of temperature beneath the FIS.

  15. Nozzle seal

    DOEpatents

    Groff, Russell Dennis; Vatovec, Richard John

    1978-06-11

    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 annular sealing members operatively disposed between the outlet nozzle and the hoop and partly within a retaining annulus formed in the hoop. The sealing members are biased against the pressure vessel and the hoop and one of the sealing members is provided with a piston type pressure ring sealing member which effectively closes the path between the inlet and outlet coolants in the region about the outlet nozzle establishing a leak-proof condition. Furthermore, the flexible responsiveness of the seal assures that the seal will not structurally couple the hoop to the pressure vessel.

  16. Distribution, density, and abundance of pack-ice seals in the Amundsen and Ross Seas, Antarctica

    NASA Astrophysics Data System (ADS)

    Bengtson, John L.; Laake, Jeff L.; Boveng, Peter L.; Cameron, Michael F.; Bradley Hanson, M.; Stewart, Brent S.

    2011-05-01

    We made three sets of population surveys of the four species of ice-inhabiting phocid pinnipeds in the Ross and Amundsen Seas between 26 December 1999 and 24 March 2000 using icebreakers and helicopters deployed from those icebreakers. We used line transect methods to survey 23,671 km by helicopter and 3,694 km by ship accounting for a total coverage of 53,217 km 2. We detected and identified 11,308 seals in 7,104 groups and estimated their abundance from estimates of densities using distance sampling methods and corrections for probability of haul out of seals derived from satellite telemetry of tagged seals. Crabeater seals were most abundant (ca 1.7 million) followed by Weddell seals (330,000), Ross seals (22,600), and leopard seals (15,000). Our estimates of abundance are difficult to directly compare with earlier estimates because of geographic areas covered and by our improvements in survey and analytical methods. Notwithstanding these limitations and with some adjustments for differences in methods, we found that our estimates of abundance for crabeater seals are similar to those from the most recent surveys in the Ross and Amundsen Seas and along the George-Oates Coast. Our estimates for Weddell seals are the first for the broad areas of pack ice that we surveyed in the Ross and Amundsen Seas but indicate that these habitats are ecologically important to this species. Our estimates of abundance of Ross seals were relatively similar to estimates for surveys in these areas in the 1970s and 1980s whereas our estimates of abundance of leopard seals were substantially lower.

  17. Ferrules seals

    DOEpatents

    Smith, James L.

    1984-01-01

    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.

  18. Ferrules seals

    DOEpatents

    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.

  19. Ceramic Seal.

    SciTech Connect

    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

    2016-11-01

    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. Seal arrangement

    DOEpatents

    Lundholm, Gunnar

    1987-01-01

    A seal arrangement is provided for preventing gas leakage along a reciprocating piston rod or other reciprocating member passing through a wall which separates a high pressure gas chmber and a low pressure gas chamber. Liquid lubricant is applied to the lower pressure side of a sealing gland surrounding the piston rod to prevent the escape of gas between the rod and the gland. The sealing gland is radially forced against the piston rod by action of a plurality of axially stacked O-rings influenced by an axially acting spring as well as pressure from the gas.

  1. Soil formation in Seymour Island, Weddell Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Souza, Katia Karoline Delpupo; Schaefer, Carlos Ernesto G. R.; Simas, Felipe Nogueira Bello; Spinola, Diogo Noses; de Paula, Mayara Daher

    2014-11-01

    The Antarctic Peninsula marks the climatic transition between Maritime and Continental Antarctica. Ice-free areas at the western side of the Peninsula (Maritime Antarctica) have been increasingly studied in the last 10 years whereas soils on the eastern coast have been relatively less studied. The objective of the present study is to analyze the properties of soils developed on Seymour Island, in the Weddell sea sector, eastern coast of the Antarctic Peninsula, in order to identify the main factors and processes involved in soil formation under semi-polar desert conditions in this part of Antarctica. Twenty-one pedons were described, sampled and analyzed for their physical, chemical and mineralogical attributes. Most of the soils were classified as Gelisols and Cryosols by the Soil Taxonomy and WRB/FAO, respectively. Three soil groups were found: immature alkaline soils on sandstones and siltstones, acid sulfate and ornithogenic soils. Soils have little cryoturbation and are all affected by salinization with natric and salic characters. Acid sulfate soils are the most weathered soils in Seymour Island. Due to the dry climate, phosphatization is still incipient with P-rich ornithogenic layers with little interaction with the mineral substrate. The Soil Taxonomy and WRB/FAO systems lack adequate classification criteria to classify all soils developed in transitional areas that are affected by a combination of salinization, sulfurization and phosphatization.

  2. Inland extent of the Weddell Sea Rift imaged by new aerogeophysical data

    NASA Astrophysics Data System (ADS)

    Jordan, Tom A.; Ferraccioli, Fausto; Ross, Neil; Corr, Hugh F. J.; Leat, Philip T.; Bingham, Rob G.; Rippin, David M.; le Brocq, Anne; Siegert, Martin J.

    2013-02-01

    The Weddell Sea Rift was a major focus for Jurassic extension and magmatism during the early stages of Gondwana break-up and underlies the Weddell Sea Embayment, which separates East Antarctica from a collage of crustal blocks in West Antarctica. Newly-collected aerogeophysical data over the catchments of Institute and Möller ice streams reveal the inland extent of the Weddell Sea Rift against the Ellsworth-Whitmore block and a hitherto unknown major left-lateral strike slip boundary between East and West Antarctica. Aeromagnetic and gravity anomalies define the regional subglacial extent of Proterozoic basement, Middle Cambrian rift-related volcanic rocks, Jurassic intrusions and sedimentary rocks of inferred post-Jurassic age. 2D and 3D magnetic depth-to-source estimates were used to help constrain joint magnetic and gravity models for the region. The models reveal that Proterozoic crust similar to that exposed at Haag Nunataks, extends southeast of the Ellsworth Mountains to the margin of the Coastal Basins. Thick granitic Jurassic intrusions are modelled at the transition between the Ellsworth-Whitmore block and the thinner crust of the Weddell Sea Rift and within the Pagano Shear Zone. The crust beneath the inland extension of the Weddell Sea Rift is modelled as being either ~ 4 km thinner compared to the adjacent Ellsworth-Whitmore block or as underlain by an up to 8 km thick mafic underplate.

  3. Explaining the Weddell Polynya--a large ocean eddy shed at Maud Rise.

    PubMed

    Holland, D M

    2001-06-01

    Satellite observations have shown the occasional occurrence of a large opening in the sea-ice cover of the Weddell Sea, Antarctica, a phenomenon known as the Weddell Polynya. The transient appearance, position, size, and shape of the polynya is explained here by a mechanism by which modest variations in the large-scale oceanic flow past the Maud Rise seamount cause a horizontal cyclonic eddy to be shed from its northeast flank. The shed eddy transmits a divergent Ekman stress into the sea ice, leading to a crescent-shaped opening in the pack. Atmospheric thermodynamical interaction further enhances the opening by inducing oceanic convection. A sea-ice-ocean computer model simulation vividly demonstrates how this mechanism fully accounts for the characteristics that mark Weddell Polynya events.

  4. Impacts of open-ocean deep convection in the Weddell Sea on coastal and bottom water temperature

    NASA Astrophysics Data System (ADS)

    Wang, Zhaomin; Wu, Yang; Lin, Xia; Liu, Chengyan; Xie, Zelin

    2016-07-01

    A high resolution global ocean-sea ice model is employed to investigate the impacts of open-ocean deep convection on coastal and bottom water temperature in the Weddell Sea. The imposed strong and persistent cyclonic wind forcing and the large loss of bottom water weaken the stratification and eventually trigger the occurrence of open-ocean deep convection in the southern limb of the Weddell Gyre in this model. The production rate of the bottom water induced by the deep convection is estimated to be about 5 Sv (1 Sv = 106 m3/s) for a polynya with a similar size to that of the observed Weddell Polynya in the mid-1970s. The cooling induced by deep convection at mid-depth is transported towards the shelf regions by standing meanders or eddies to affect the basal melting of ice shelves, and is transported westward by an intensified slope current; interior coastal temperature in regions with a broader continental shelf is less affected by the deep convection, as the intensified slope current acts to suppress heat exchanges across the shelf break. Also, the deep convection causes warming in the Weddell bottom water around the convection site, when the simulated polynya size is similar to that of the observed Weddell Polynya in the mid-1970s. This finding sheds light on the observed non-monotonic decadal change (cooling between 1984-1992 and warming between 1998-2008) in the Weddell bottom water temperature. When the simulated polynya further develops into a large size across the Weddell Sea, the sustained broad deep convection causes large cooling in the bottom water in the western Weddell Sea and warming in the eastern Weddell Sea, with the bottom water temperature also being strongly modulated by a greatly intensified Weddell Gyre.

  5. Heartworm (Acanthocheilonema spirocauda) and seal louse (Echinophthirius horridus) infections in harbour seals (Phoca vitulina) from the North and Baltic Seas

    NASA Astrophysics Data System (ADS)

    Lehnert, Kristina; Schwanke, Eva; Hahn, Kerstin; Wohlsein, Peter; Siebert, Ursula

    2016-07-01

    The seal louse (Echinophthirius [E.] horridus) and the heartworm (Acanthocheilonema [A.] spirocauda) are parasites of harbour seal (Phoca vitulina). Little is known about the role of the seal louse as a potential vector and its role for the development and transmission of heartworm larvae to their final host, the harbour seal. The life-cycle of the heartworm is still not fully understood. For the presented study, findings of 1191 stranded harbour seals collected along the North- and Baltic Sea coast between 1996 and 2013 were examined. 4.4% (n = 53) of these harbour seals were infected with adult heartworms and 3.4% (n = 40) harbour seals carried seal lice. The highest prevalence and level of infection with adult heartworms (A. spirocauda) (9.3%) and seal lice (E. horridus) (8.9%) were found on yearling harbour seals (7-18 months) compared to neonate and adult seals. Investigating seal lice (n = 35) for larval heartworm stages one larvae was encountered in an ethanol-fixated seal louse. During a health monitoring survey of live harbour seals, 109 animals were captured and examined during spring and autumn between 2008 and 2014. Blood samples were taken and microfilariae were discovered in blood smears in 41% (n = 45) of the examined harbour seals. Yearling seals (n = 21) showed higher prevalence (86%) and level of infection with microfilariae than adults. Microfilariae were identified as A. spirocauda by sequencing the species-specific COI gene in 24 blood samples. The high prevalence of microfilariae of A. spirocauda in blood samples (41%) is in contrast to the low prevalence of mature infections/adult specimens in stranded seals (4.4%) investigated. Although rare parasites of seals, the recent increase in prevalence of heartworm and seal lice in stranded seals and the relatively high occurrence of microfilaria in the free-ranging population underscore the importance of further studies investigating the immunology of infections and their transmission pathways, as

  6. A possible small plate in the northwest Weddell Sea?

    NASA Astrophysics Data System (ADS)

    Lawver, L. A.; Ghidella, M. E.; Gahagan, L.; Lavier, L. L.

    2011-12-01

    Using the only unambiguously identified magnetic anomalies in the Weddell Sea, chrons C33n/C33r/C34 as markers, synthetic flowlines were calculated from major plate motions between South America (SAM) and Africa (AFR) and between AFR and East Antarctica (ANT). The flowlines produce a remarkable match with satellite-derived gravity "fracture zone" lineations (Sandwell and Smith, 2009) between C33r/C34n to where the present day SAM - ANT spreading center either is or should be. Our synthetic flowlines imply that a present day SAM - ANT spreading center may still exist or be very recently deceased, south of the South Sandwich Fracture Zone in an area that has high heat flow, ~180 mW/m2. If such a spreading center does indeed still exist then there would be a very small remnant of the South American plate located to the east of Jane and Discovery Banks but separated from the SAM plate by the recent, rapid, eastward motion of the South Sandwich trench and plate. While an active spreading center should be apparent from seismic events, there are remarkably few epicenters along the possible, phantom spreading center. While the lack of apparent teleseismic events and the lack of the tell-tale gravity low associated with many abandoned spreading centers argue against a relict spreading center, synthetic magnetic anomalies, generated using the major plate motions give an excellent match for anomalies younging from the C33r/C34n marker with shipboard collected anomalies as young as C5c (~16 Ma). The shipboard anomaly locations agree quite well with the flowline picks for anomalies ranging from C25 (~56 Ma) to C5c. There is also at least one match between the synthetic and marine magnetic anomalies collected on a crossing of the possible spreading center, with the possible match extending out to C4 (~7.5 Ma). All of the magnetic anomaly matches younger than C25 disagree with the previously published interpretations for anomalies in the northwest Weddell Sea. Those

  7. End-tidal sevoflurane concentration for ProSeal(TM) versus Classic(TM) laryngeal mask airway insertion in unpremedicated anaesthetised adult females.

    PubMed

    Ghai, B; Jain, K; Bansal, D; Bhatia, N

    2016-03-01

    The optimal end-tidal sevoflurane concentration for successful ProSealTM (Teleflex, Morrisville, NC, USA) laryngeal mask airway (PLMA) versus ClassicTM (Teleflex, Morrisville, NC, USA) laryngeal mask airway (CLMA) insertion in unpremedicated anaesthetised adults is unknown. We determined end-tidal sevoflurane concentrations for successful insertion in fifty percent of anaesthetised adults. This randomised, prospective, double-blind study was conducted in the operating theatre of a government tertiary care hospital. Forty-four unpremedicated American Society of Anesthesiologists physical status I and II women with cervical carcinoma (aged 30 to 60 years), scheduled for intracavity caesium implantation under general anaesthesia with a laryngeal mask airway (LMA) were included in the study. The participants were randomised to one of the two groups, to receive either a PLMA or CLMA. After anaesthetic induction with sevoflurane, a predetermined end-tidal sevoflurane concentration (starting at 2.5%) was sustained for 10 minutes before LMA insertion was attempted. End-tidal sevoflurane concentration was increased/decreased (step-size 0.25%) using Dixon and Massey's up-and-down method for the next patient based on the previous patient's response. Placement without clenching, movement, coughing or biting within one minute was considered successful insertion. The end-tidal sevoflurane concentration required for successful LMA insertion in fifty percent of anaesthetised adults was calculated as the mean of the crossover pairs' midpoints in each group and further confirmed by probit regression analysis. The end-tidal sevoflurane concentration (95% confidence interval) required for successful PLMA insertion in 50% of anaesthetised adults (3.15% [3.12% to 3.18%]) was significantly higher than that for CLMA insertion (2.71% [2.66% to 2.76%], P<0.001). These findings suggest that deeper anaesthesia is required for placement of a PLMA in comparison to a CLMA.

  8. The sun, moon, wind, and biological imperative-shaping contrasting wintertime migration and foraging strategies of adult male and female northern fur seals (Callorhinus ursinus).

    PubMed

    Sterling, Jeremy T; Springer, Alan M; Iverson, Sara J; Johnson, Shawn P; Pelland, Noel A; Johnson, Devin S; Lea, Mary-Anne; Bond, Nicholas A

    2014-01-01

    Adult male and female northern fur seals (Callorhinus ursinus) are sexually segregated in different regions of the North Pacific Ocean and Bering Sea during their winter migration. Explanations for this involve interplay between physiology, predator-prey dynamics, and ecosystem characteristics, however possible mechanisms lack empirical support. To investigate factors influencing the winter ecology of both sexes, we deployed five satellite-linked conductivity, temperature, and depth data loggers on adult males, and six satellite-linked depth data loggers and four satellite transmitters on adult females from St. Paul Island (Bering Sea, Alaska, USA) in October 2009. Males and females migrated to different regions of the North Pacific Ocean: males wintered in the Bering Sea and northern North Pacific Ocean, while females migrated to the Gulf of Alaska and California Current. Horizontal and vertical movement behaviors of both sexes were influenced by wind speed, season, light (sun and moon), and the ecosystem they occupied, although the expression of the behaviors differed between sexes. Male dive depths were aligned with the depth of the mixed layer during daylight periods and we suspect this was the case for females upon their arrival to the California Current. We suggest that females, because of their smaller size and physiological limitations, must avoid severe winters typical of the northern North Pacific Ocean and Bering Sea and migrate long distances to areas of more benign environmental conditions and where prey is shallower and more accessible. In contrast, males can better tolerate often extreme winter ocean conditions and exploit prey at depth because of their greater size and physiological capabilities. We believe these contrasting winter behaviors 1) are a consequence of evolutionary selection for large size in males, important to the acquisition and defense of territories against rivals during the breeding season, and 2) ease environmental

  9. The Sun, Moon, Wind, and Biological Imperative–Shaping Contrasting Wintertime Migration and Foraging Strategies of Adult Male and Female Northern Fur Seals (Callorhinus ursinus)

    PubMed Central

    Sterling, Jeremy T; Springer, Alan M.; Iverson, Sara J.; Johnson, Shawn P.; Pelland, Noel A.; Johnson, Devin S.; Lea, Mary-Anne; Bond, Nicholas A.

    2014-01-01

    Adult male and female northern fur seals (Callorhinus ursinus) are sexually segregated in different regions of the North Pacific Ocean and Bering Sea during their winter migration. Explanations for this involve interplay between physiology, predator-prey dynamics, and ecosystem characteristics, however possible mechanisms lack empirical support. To investigate factors influencing the winter ecology of both sexes, we deployed five satellite-linked conductivity, temperature, and depth data loggers on adult males, and six satellite-linked depth data loggers and four satellite transmitters on adult females from St. Paul Island (Bering Sea, Alaska, USA) in October 2009. Males and females migrated to different regions of the North Pacific Ocean: males wintered in the Bering Sea and northern North Pacific Ocean, while females migrated to the Gulf of Alaska and California Current. Horizontal and vertical movement behaviors of both sexes were influenced by wind speed, season, light (sun and moon), and the ecosystem they occupied, although the expression of the behaviors differed between sexes. Male dive depths were aligned with the depth of the mixed layer during daylight periods and we suspect this was the case for females upon their arrival to the California Current. We suggest that females, because of their smaller size and physiological limitations, must avoid severe winters typical of the northern North Pacific Ocean and Bering Sea and migrate long distances to areas of more benign environmental conditions and where prey is shallower and more accessible. In contrast, males can better tolerate often extreme winter ocean conditions and exploit prey at depth because of their greater size and physiological capabilities. We believe these contrasting winter behaviors 1) are a consequence of evolutionary selection for large size in males, important to the acquisition and defense of territories against rivals during the breeding season, and 2) ease environmental

  10. The comparison of ProSeal and I-gel laryngeal mask airways in anesthetized adult patients under controlled ventilation

    PubMed Central

    Ekinci, Osman; Abitagaoglu, Süheyla; Turan, Güldem; Sivrikaya, Zübeyir; Bosna, Gülşen; Özgultekin, Asu

    2015-01-01

    Objectives: To compare the insertion time, ease of device insertion, ease of gastric tube insertion, airway leakage pressure, and complications between the laryngeal mask airway (LMA) ProSeal (P-LMA) and I-gel (I-gel) groups. Methods: Eighty patients with age range 18-65 years who underwent elective surgery were included in the study. The study took place in the operation rooms of Haydarpaşa Numune Hospital, Istanbul, Turkey from November 2013 to April 2014. Patients were equally randomized into 2 groups; the I-gel group, and the P-LMA group. In both groups, the same specialist inserted the supraglottic airway devices. The insertion time of the devices, difficulty during insertion, difficulty during gastric tube insertion, coverage of airway pressure, and complications were recorded. Results: The mean insertion time in the I-gel group was significantly lower than that of the P-LMA group (I-gel: 8±3; P-LMA: 13±5 s). The insertion success rate was higher in the I-gel group (100%, first attempt) than in the P-LMA group (82.5%, first attempt). The gastric tube placement success rate was higher in the I-gel group (92.5%, first attempt) than in the P-LMA group (72.5%, first attempt). The airway leakage pressures were similar. Conclusion: Insertion was easier, insertion time was lower, and nasogastric tube insertion success was higher with the I-gel application, and is, therefore, the preferred LMA. PMID:25828279

  11. On the warm inflow at the eastern boundary of the Weddell Gyre

    NASA Astrophysics Data System (ADS)

    Ryan, S.; Schröder, M.; Huhn, O.; Timmermann, R.

    2016-01-01

    The Weddell Sea plays an important role for the global oceans and climate by being one of the biggest production and export areas of Antarctic Bottom Water (AABW). Circumpolar Deep Water (CDW) enters the Weddell Gyre (WG) at its eastern boundary. Then called Warm Deep Water (WDW), it is a major contributor to the formation of deep and bottom waters due to ocean-ice shelf interactions in the southern and soutwestern Weddell Sea. Hydrographic data collected between 0 and 30°E on the RV Polarstern cruise ANT XX/2 reveals a two-core structure for the eastern inflow of warm water at roughly 20°E but not further downstream at the Greenwich meridian (GM). Model results and climatological fields suggest that the two cores represent two separate modes of warm inflow. One mode is driven by eddy mixing in the northeastern corner of the WG and the other one is an advective mode, forming the southern branch of the inflow which extends beyond 30°E before turning westward. Both pathways are likely to carry waters from different origins within the Antarctic Circumpolar Current ACC, where more ventilated CDW is found at the Southern Boundary SB compared to the centre. The southern route shows considerable interannual variability in the model. A variable inflow of two types of CDW together with admixed recirculated and cooler waters from the Weddell Sea can potentially contribute to the observed variability and warming trend of WDW over the last decade at the GM.

  12. Sea ice thickness in the Weddell Sea, inferred from upward looking sonar measurements

    NASA Astrophysics Data System (ADS)

    Behrendt, Axel; Dierking, Wolfgang; Witte, Hannelore

    2014-05-01

    Sea ice has been routinely monitored by satellites since 1979. However, thickness measurements of sea ice are still very sparse, especially in the Southern Hemisphere. Satellite altimetry still provides relatively uncertain estimates of ice thickness. Today, the only tool for monitoring sea ice thickness over long time periods with highest accuracy (5-10 cm) are moored upward looking sonars (ULS). The instruments measure the subsurface portion (draft) of the ice, which can be converted into total ice thickness. We present a data set of ULS time series from 13 positions in the Atlantic sector of the Southern Ocean (Weddell Sea), which were made in different years between 1990 and 2010. Monthly mean sea ice draft shows high interannual variability and can reach more than 3 m in the dynamic coastal regions of the eastern and western Weddell Sea. The thinnest ice is found away from the coast in the eastern Weddell Sea and rarely exceeds 1 m in the monthly mean. In single years the ULS data allow for a clear discrimination between thermodynamic ice growth and dynamic ice growth due to rafting and ridging of the floes. We demonstrate that the thermodynamic ice thickness can reach its theoretical maximum value of 1 m in the central Weddell basin. Despite significant gaps, the presented data set provides an important validation tool for satellite algorithms and sea ice models.

  13. Forming a seal between planar sealing surfaces

    SciTech Connect

    Ezekoye, L.I.; Rusnica, E.J.; Sepp, H.A. Jr.

    1987-12-29

    A method of forming a seal between the confronting planar sealing surfaces on two annular structural members which are drawn together by axially extending bolts is described comprising the steps of: forming a seal assembly by locking a toroidal, crushable seal member within a substantially flat annular spacer member against an annular shoulder formed on the inner diameter thereof with an annular resilient member seated in a radially extending groove in the inner surface of the substantially flat annular member, the flat annular member being axially thinner than the toroidal, crushable seal member; placing the sealing assembly between the planar sealing surfaces and positively aligning the assembly relative to the axially extending bolts; and tightening the bolts to draw the planar sealing surfaces toward each other and into contact with the flat annular member while crushing the toroidal, crushable seal member to form a seal between the planar sealing surfaces.

  14. Python fiber optic seal

    SciTech Connect

    Ystesund, K.; Bartberger, J.; Brusseau, C.; Fleming, P.; Insch, K.; Tolk, K.

    1993-08-01

    Sandia National Laboratories has developed a high security fiber optic seal that incorporates tamper resistance features that are not available in commercial fiber optic seals. The Python Seal is a passive fiber optic loop seal designed to give indication of unauthorized entry. The seal includes a fingerprint feature that provides seal identity information in addition to the unique fiber optic pattern created when the seal is installed. The fiber optic cable used for the seal loop is produced with tamper resistant features that increase the difficulty of attacking that component of a seal. A Seal Reader has been developed that will record the seal signature and the fingerprint feature of the seal. A Correlator software program then compares seal images to establish a match or mismatch. SNL is also developing a Polaroid reader to permit hard copies of the seal patterns to be obtained directly from the seal.

  15. GAS SEAL

    DOEpatents

    Monson, H.; Hutter, E.

    1961-07-11

    A seal is described for a cover closing an opening in the top of a pressure vessel that may house a nuclear reactor. The seal comprises a U-shaped trough formed on the pressure vessel around the opening therein, a mass of metal in the trough, and an edge flange on the cover extending loosely into the trough and dipping into the metal mass. The lower portion of the metal mass is kept melted, and the upper portion, solid. The solid pontion of the metal mass prevents pressure surges in the vessel from expelling the liquid portion of the metal mass from the trough; the liquld portion, thus held in place by the solid portion, does not allow gas to go through, and so gas cannot escape through shrinkage holes in the solid portion.

  16. Current prevalence of adult Uncinaria spp. in northern fur seal (Callorhinus ursinus) and California sea lion (Zalophus californianus) pups on San Miguel Island, California, with notes on the biology of these hookworms.

    PubMed

    Lyons, E T; Melin, S R; DeLong, R L; Orr, A J; Gulland, F M; Tolliver, S C

    2001-06-28

    A prevalence survey for hookworms (Uncinaria spp.) was done in northern fur seal (Callorhinus ursinus) and California sea lion (Zalophus californianus) pups on San Miguel Island, CA, in 2000. Intestines of dead pups were examined for adult hookworms in July. These parasites were found in 95% of 20 fur seal pups and 100% of 31 sea lion pups. The number of hookworms varied from 4 to 2142 (mean = 760) in fur seal pups and from 20 to 2634 (mean = 612) in sea lion pups. A direct relationship was evident between body condition and number of hookworms in the pups; that is, pups in poor condition had fewer hookworms than those in good condition. There was a decline in the number of hookworms in sea lion pups in 2000 compared to collections in 1996. Eggs of Uncinaria spp. were found in rectal feces (collected in late September and early October) of none of 35 (0%) live fur seal pups and 41 of 48 (85%) live sea lion pups. Packed cell volume values, determined for most of the same live pups, were essentially normal for C. ursinus but were much lower than normal for most Z. californianus. Hookworm larvae were not found in blubber of fur seal and sea lion pups or in rookery sand in July. Rookery sand, positive for live hookworm larvae when put in a refrigerator, was negative at removal 2.5 years later. The average number of eggs in utero of female hookworms was 285 for three specimens from a fur seal pup and 281 from three specimens from a sea lion pup. One hookworm larva was recovered from milk stripped from the teats of a stranded Z. californianus female at The Marine Mammal Center, Sausalito, CA.

  17. Fluid pressure balanced seal

    NASA Technical Reports Server (NTRS)

    Marsh, H. W. (Inventor)

    1966-01-01

    A seal which increases in effectiveness with increasing pressure is presented. The seal's functional capability throughout both static and dynamic operation makes it particularly useful for sealing ball valve ports. Other features of the seal include the ability to seal two opposed surfaces simultaneously, tolerance of small misalignments, tolerance of wide temperature ranges, ability to maintain positive sealing contact under conditions of internal or external pressurization, and ability to conform to slight irregularities in seal or surface contours.

  18. Investigations of peritoneal and intestinal infections of adult hookworms (Uncinaria spp.) in northern fur seal (Callorhinus ursinus) and California sea lion (Zalophus californianus) pups on San Miguel Island, California (2003).

    PubMed

    Lyons, Eugene T; Delong, R L; Nadler, S A; Laake, J L; Orr, A J; Delong, B L; Pagan, C

    2011-09-01

    The peritoneal cavity (PNC) and intestine of northern fur seal (Callorhinus ursinus) pups and California sea lion (Zalophus californianus) pups that died in late July and early August, 2003, on San Miguel Island, California, were examined for hookworms. Prevalence and morphometric studies were done with the hookworms in addition to molecular characterization. Based on this and previous molecular studies, hookworms from fur seals are designated as Uncinaria lucasi and the species from sea lions as Uncinaria species A. Adult hookworms were found in the PNC of 35 of 57 (61.4%) fur seal pups and of 13 of 104 (12.5%) sea lion pups. The number of hookworms located in the PNC ranged from 1 to 33 (median = 3) for the infected fur seal pups and 1 to 16 (median = 2) for the infected sea lion pups. In addition to the PNC, intestines of 43 fur seal and 32 sea lion pups were examined. All of these pups were positive for adult hookworms. The worms were counted from all but one of the sea lion pups. Numbers of these parasites in the intestine varied from 3 to 2,344 (median = 931) for the fur seal pups and 39 to 2,766 (median = 643) for the sea lion pups. Sea lion pups with peritoneal infections had higher intensity infections in the intestines than did pups without peritoneal infections, lending some support for the hypothesis that peritoneal infections result from high-intensity infections of adult worms. There was no difference in intestinal infection intensities between fur seal pups with and without peritoneal infections. Female adult hookworms in the intestines of both host species were significantly larger than males, and sea lion hookworms were larger than those in fur seals. Worms in the intestine also were larger than worms found in the PNC. Gene sequencing and (RFLP) analysis of (PCR) amplified (ITS) ribosomal DNA were used to diagnose the species of 172 hookworms recovered from the PNC and intestine of 18 C. ursinus and seven Z. californianus hosts

  19. Turbine with radial acting seal

    SciTech Connect

    Eng, Darryl S; Ebert, Todd A

    2016-11-22

    A floating brush seal in a rim cavity of a turbine in a gas turbine engine, where the floating brush seal includes a seal holder in which the floating brush seal floats, and a expandable seal that fits within two radial extending seal slots that maintains a seal with radial displacement of the floating brush seal and the seal holder.

  20. Dynamic Face Seal Arrangement

    NASA Technical Reports Server (NTRS)

    Dellacorte, Christopher (Inventor)

    1999-01-01

    A radial face seal arrangement is disclosed comprising a stationary seal ring that is spring loaded against a seal seat affixed to a rotating shaft. The radial face seal arrangement further comprises an arrangement that not only allows for preloading of the stationary seal ring relative to the seal seat, but also provides for dampening yielding a dynamic seating response for the radial face seal arrangement. The overall seal system, especially regarding the selection of the material for the stationary seal ring, is designed to operate over a wide temperature range from below ambient up to 900 C.

  1. Regenerator seal design

    DOEpatents

    Eckart, Francis H.

    1982-01-01

    A rotary regenerator disc matrix has a face seal with a cross arm and arcuate rim segments joined by prestress clamps to prestrain the arcuate rim seals so as to compensate seal rim twisting or coning and resultant disc face seal leakage as produced by operating thermal gradients across the seal.

  2. Sealing arrangement

    SciTech Connect

    Brandenstein, M.; Hans, R.; Kiener, H.

    1985-04-09

    An hydraulically operated clutch release has an annular piston hydraulically moveable in an annular chamber. A felt ring is mounted on a shoulder of the piston away from the chamber, to engage the bore surface of the chamber, and a holding ring is snapped onto the end of the shoulder to hold the felt ring on the shoulder. An extension of the holding ring forms a seal with the bore on the chamber, and defines, with the felt ring a dust catching recesS.

  3. Shifts in Ross Sea food web structure as indicated by δ15N and δ13C values of fossil Antarctic seals

    NASA Astrophysics Data System (ADS)

    Leopold, A.; Brault, E.; McMahon, K.

    2013-12-01

    As climate change continues to mount, there is a growing need for understanding its effects on biological-physical interactions of marine ecosystems. Assessing the effects of anthropogenic activities on the coastal marine ecosystem involves understanding the underlying mechanisms driving these changes as well as establishing baselines of the natural system. Preliminary findings have indicated shifts in bulk carbon (C) and nitrogen (N) isotopic values of southern elephant seal (Mirounga leonina) samples, collected in the Dry Valleys of Antarctica in the Ross Sea region, over approximately the last 7,000 years. These shifts could result from 1) seals changing their foraging location and/or diet over this time, 2) climate change-induced shifts in the biogeochemistry at the base of the food web, or 3) some combination of both processes. We explored the patterns of long-term change in Ross Sea food web structure by examining the stable isotope values of three top predators in this system, Weddell seals (Leptonychotes weddellii), leopard seals (Hydrurga leptonyx), and crabeater seals (Lobodon carcinophagus). Fossil seal samples were collected in the Dry Valleys during the austral summer of 2012/13 and then analyzed for bulk C and N isotopes via an elemental analyzer/isotope-ratio mass spectrometer (EA/IRMS). Our initial findings indicate that C isotopic values of fossil seal samples from Weddell, leopard, and crabeater seals were more enriched than isotopic values of modern seals of the same species (e.g., δ13C = -22.79 × 0.92 ‰ and -26.71 × 0.50 ‰ for fossil and modern crabeater seals, respectively). Given the relatively consistent diet of crabeater seals, these findings suggest a shift in baseline food web structure occurred over the last 10,000 years, either through changes in foraging location or local shifts in biogeochemistry. For all species, N isotopic values are widely variable (e.g., 7.28 to 16.0 δ15N ‰ for the Weddell seal), which may be a result of

  4. Regenerator seal

    DOEpatents

    Davis, Leonard C.; Pacala, Theodore; Sippel, George R.

    1981-01-01

    A method for manufacturing a hot side regenerator cross arm seal assembly having a thermally stablilized wear coating with a substantially flat wear surface thereon to seal between low pressure and high pressure passages to and from the hot inboard side of a rotary regenerator matrix includes the steps of forming a flat cross arm substrate member of high nickel alloy steel; fixedly securing the side edges of the substrate member to a holding fixture with a concave surface thereacross to maintain the substrate member to a slightly bent configuration on the fixture surface between the opposite ends of the substrate member to produce prestress therein; applying coating layers on the substrate member including a wear coating of plasma sprayed nickel oxide/calcium flouride material to define a wear surface of slightly concave form across the restrained substrate member between the free ends thereon; and thereafter subjecting the substrate member and the coating thereon to a heat treatment of 1600.degree. F. for sixteen hours to produce heat stabilizing growth in the coating layers on the substrate member and to produce a thermally induced growth stress in the wear surface that substantially equalizes the prestress in the substrate whereby when the cross arm is removed from the fixture surface following the heat treatment step a wear face is formed on the cross arm assembly that will be substantially flat between the ends.

  5. Damper Spring For Omega Seal

    NASA Technical Reports Server (NTRS)

    Maclaughlin, Scott T.; Montgomery, Stuart K.

    1993-01-01

    Damper spring reduces deflections of omega-cross-section seal, reducing probability of failure and extending life of seal. Spring is split ring with U-shaped cross section. Placed inside omega seal and inserted with seal into seal cavity. As omega seal compressed into cavity, spring and seal make contact near convolution of seal, and spring becomes compressed also. During operation, when seal dynamically loaded, spring limits deflection of seal, reducing stress on seal.

  6. Triple acting radial seal

    SciTech Connect

    Ebert, Todd A; Carella, John A

    2012-03-13

    A triple acting radial seal used as an interstage seal assembly in a gas turbine engine, where the seal assembly includes an interstage seal support extending from a stationary inner shroud of a vane ring, the interstage seal support includes a larger annular radial inward facing groove in which an outer annular floating seal assembly is secured for radial displacement, and the outer annular floating seal assembly includes a smaller annular radial inward facing groove in which an inner annular floating seal assembly is secured also for radial displacement. A compliant seal is secured to the inner annular floating seal assembly. The outer annular floating seal assembly encapsulates the inner annular floating seal assembly which is made from a very low alpha material in order to reduce thermal stress.

  7. Gravity field of the Western Weddell Sea: Comparison of airborne gravity and Geosat derived gravity

    NASA Technical Reports Server (NTRS)

    Bell, R. E.; Brozena, J. M.; Haxby, W. F.; Labrecque, J. L.

    1989-01-01

    Marine gravity surveying in polar regions was typically difficult and costly, requiring expensive long range research vessels and ice-breakers. Satellite altimetry can recover the gravity field in these regions where it is feasible to survey with a surface vessel. Unfortunately, the data collected by the first global altimetry mission, Seasat, was collected only during the austral winter, producing a very poor quality gravitational filed for the southern oceans, particularly in the circum-Antarctic regions. The advent of high quality airborne gravity (Brozena, 1984; Brozena and Peters, 1988; Bell, 1988) and the availability of satellite altimetry data during the austral summer (Sandwell and McAdoo, 1988) has allowed the recovery of a free air gravity field for most of the Weddell Sea. The derivation of the gravity field from both aircraft and satellite measurements are briefly reviewed, before presenting along track comparisons and shaded relief maps of the Weddell Sea gravity field based on these two data sets.

  8. Fundamentals of fluid sealing

    NASA Technical Reports Server (NTRS)

    Zuk, J.

    1976-01-01

    The fundamentals of fluid sealing, including seal operating regimes, are discussed and the general fluid-flow equations for fluid sealing are developed. Seal performance parameters such as leakage and power loss are presented. Included in the discussion are the effects of geometry, surface deformations, rotation, and both laminar and turbulent flows. The concept of pressure balancing is presented, as are differences between liquid and gas sealing. Mechanisms of seal surface separation, fundamental friction and wear concepts applicable to seals, seal materials, and pressure-velocity (PV) criteria are discussed.

  9. Model sensitivity of the Weddell and Ross seas, Antarctica, to vertical mixing and freshwater forcing

    NASA Astrophysics Data System (ADS)

    Kjellsson, Joakim; Holland, Paul R.; Marshall, Gareth J.; Mathiot, Pierre; Aksenov, Yevgeny; Coward, Andrew C.; Bacon, Sheldon; Megann, Alex P.; Ridley, Jeff

    2015-10-01

    We examine the sensitivity of the Weddell and Ross seas to vertical mixing and surface freshwater forcing using an ocean-sea ice model. The high latitude Southern Ocean is very weakly stratified, with a winter salinity difference across the pycnocline of only ∼0.2 PSU. We find that insufficient vertical mixing, freshwater supply from the Antarctic Ice Sheet, or initial sea ice causes a high salinity bias in the mixed layer which erodes the stratification and causes excessive deep convection. This leads to vertical homogenisation of the Weddell and Ross seas, opening of polynyas in the sea ice and unrealistic spin-up of the subpolar gyres and Antarctic Circumpolar Current. The model freshwater budget shows that a ∼30% error in any component can destratify the ocean in about a decade. We find that freshwater forcing in the model should be sufficient along the Antarctic coastline to balance a salinity bias caused by dense coastal water that is unable to sink to the deep ocean. We also show that a low initial sea ice area introduces a salinity bias in the marginal ice zone. We demonstrate that vertical mixing, freshwater forcing and initial sea ice conditions need to be constrained simultaneously to reproduce the Southern Ocean hydrography, circulation and sea ice in a model. As an example, insufficient vertical mixing will cause excessive convection in the Weddell and Ross seas even in the presence of large surface freshwater forcing and initial sea ice cover.

  10. Freshwater fluxes in the Weddell Gyre: results from δ18O

    PubMed Central

    Brown, Peter J.; Meredith, Michael P.; Jullion, Loïc; Naveira Garabato, Alberto; Torres-Valdés, Sinhue; Holland, Paul; Leng, Melanie J.; Venables, Hugh

    2014-01-01

    Full-depth measurements of δ18O from 2008 to 2010 enclosing the Weddell Gyre in the Southern Ocean are used to investigate the regional freshwater budget. Using complementary salinity, nutrients and oxygen data, a four-component mass balance was applied to quantify the relative contributions of meteoric water (precipitation/glacial input), sea-ice melt and saline (oceanic) sources. Combination of freshwater fractions with velocity fields derived from a box inverse analysis enabled the estimation of gyre-scale budgets of both freshwater types, with deep water exports found to dominate the budget. Surface net sea-ice melt and meteoric contributions reach 1.8% and 3.2%, respectively, influenced by the summer sampling period, and −1.7% and +1.7% at depth, indicative of a dominance of sea-ice production over melt and a sizable contribution of shelf waters to deep water mass formation. A net meteoric water export of approximately 37 mSv is determined, commensurate with local estimates of ice sheet outflow and precipitation, and the Weddell Gyre is estimated to be a region of net sea-ice production. These results constitute the first synoptic benchmarking of sea-ice and meteoric exports from the Weddell Gyre, against which future change associated with an accelerating hydrological cycle, ocean climate change and evolving Antarctic glacial mass balance can be determined. PMID:24891394

  11. Middle Miocene to present sediment transport and deposits in the Southeastern Weddell Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Huang, Xiaoxia; Jokat, Wilfried

    2016-04-01

    Understanding the transport and deposition of sediments along the Antarctic continental shelves helps to provide constraints on past ice sheet dynamics. Seismic stratigraphic and scientific drilling data from the Antarctic continental margins have provided much direct evidence concerning ice sheet evolution and sedimentation history. In this study, we describe a series of sedimentary features along the continental margin of the southeastern Weddell Sea to constrain glacial-influenced sedimentation processes from the Middle Miocene to the present. The Crary Trough Mouth Fan (CTMF), channel systems, Mix-system turbidity-contourites are investigated by using seismic reflection, sub-bottom profiler, and results from ODP Site 693. The sinuous, NE-SW-oriented turbidity-contourites are characterized by bathymetric highs that are more than 150 km wide, 700 km long, and have a sediment thickness of up to 2 km. The unique sedimentation environment of the southeastern Weddell Sea is controlled by a large catchment area and its fast (paleo-)ice streams feeding the Filchner Ronne Ice Shelf, turbidity/bottom currents as well as sea level changes. A remarkable increase in mass transport deposits (MTDs) in the Late Miocene and Early Pliocene strata has been related to, ice sheet loading, eustatic sea level fall, earthquakes, and overpressure of rapid sediment accumulation. Our seismic records also imply that fluctuations of East Antarctic ice sheet similar to those that occurred during the last glacial cycle might have been typical for southeastern Weddell Sea during glacial periods since the Late Miocene or even earlier.

  12. On the relation between organic and inorganic carbon in the Weddell Sea

    NASA Astrophysics Data System (ADS)

    Wedborg, Margareta; Hoppema, Mario; Skoog, Annelie

    1998-11-01

    Carbon cycling in the Weddell Sea was investigated during the ANT X/7 cruise with `FS Polarstern' December 1992-January 1993. Samples were taken on a cross section from Kapp Norvegia to Joinville Island, and on a section from the Larsen Ice Shelf to the northeast. The following quantities were measured: total carbon dioxide (TCO 2), fluorescence from humic substances and total organic carbon. The distribution of TCO 2 was strongly positively correlated to the time elapsed since the various water masses were last ventilated. In general, humic substance fluorescence was positively correlated with TCO 2, with the exception of the productive part of the western Weddell Sea, where the correlation was negative in the surface mixed layer. The increased fluorescence at the surface is suggested to be a result of biological production. The distribution of total organic carbon showed less structure, since this quantity includes a particulate component, which is subject to dispersion processes different from those of the dissolved components TCO 2 and humic substances. The mean total organic carbon concentration below the surface mixed layer was 50 μmol l -1. At some stations, a steep TOC maximum around 2000 m depth was observed. This was interpreted to result from mass sinking of phytoplankton blooms. Total organic carbon had a maximum in surface water, and at some stations also a second subsurface maximum. In the Warm Deep Water (WDW), TCO 2 and fluorescence had their maximum values, while total organic carbon tended to be low. In low productivity surface water in the eastern part of the Kapp Norvegia-Joinville Island section, the lowest flourescence was found. Surface water is eventually formed from Warm Deep Water, which had the highest fluorescence values, and therefore it is concluded that humic substances were removed in situ from surface water. In the central area of the Weddell Sea, TCO 2 and fluorescence showed the highest Warm Deep Water maxima, while total organic

  13. A colostrum trypsin inhibitor gene expressed in the Cape fur seal mammary gland during lactation.

    PubMed

    Pharo, Elizabeth A; Cane, Kylie N; McCoey, Julia; Buckle, Ashley M; Oosthuizen, W H; Guinet, Christophe; Arnould, John P Y

    2016-03-01

    The colostrum trypsin inhibitor (CTI) gene and transcript were cloned from the Cape fur seal mammary gland and CTI identified by in silico analysis of the Pacific walrus and polar bear genomes (Order Carnivora), and in marine and terrestrial mammals of the Orders Cetartiodactyla (yak, whales, camel) and Perissodactyla (white rhinoceros). Unexpectedly, Weddell seal CTI was predicted to be a pseudogene. Cape fur seal CTI was expressed in the mammary gland of a pregnant multiparous seal, but not in a seal in its first pregnancy. While bovine CTI is expressed for 24-48 h postpartum (pp) and secreted in colostrum only, Cape fur seal CTI was detected for at least 2-3 months pp while the mother was suckling its young on-shore. Furthermore, CTI was expressed in the mammary gland of only one of the lactating seals that was foraging at-sea. The expression of β-casein (CSN2) and β-lactoglobulin II (LGB2), but not CTI in the second lactating seal foraging at-sea suggested that CTI may be intermittently expressed during lactation. Cape fur seal and walrus CTI encode putative small, secreted, N-glycosylated proteins with a single Kunitz/bovine pancreatic trypsin inhibitor (BPTI) domain indicative of serine protease inhibition. Mature Cape fur seal CTI shares 92% sequence identity with Pacific walrus CTI, but only 35% identity with BPTI. Structural homology modelling of Cape fur seal CTI and Pacific walrus trypsin based on the model of the second Kunitz domain of human tissue factor pathway inhibitor (TFPI) and porcine trypsin (Protein Data Bank: 1TFX) confirmed that CTI inhibits trypsin in a canonical fashion. Therefore, pinniped CTI may be critical for preventing the proteolytic degradation of immunoglobulins that are passively transferred from mother to young via colostrum and milk.

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

    PubMed

    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.

  15. Turbine disc sealing assembly

    DOEpatents

    Diakunchak, Ihor S.

    2013-03-05

    A disc seal assembly for use in a turbine engine. The disc seal assembly includes a plurality of outwardly extending sealing flange members that define a plurality of fluid pockets. The sealing flange members define a labyrinth flow path therebetween to limit leakage between a hot gas path and a disc cavity in the turbine engine.

  16. Mechanical seal assembly

    DOEpatents

    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.

  17. Mechanical seal assembly

    DOEpatents

    Kotlyar, Oleg M.

    2002-01-01

    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 transfering it to the mechanical diode.

  18. Turbine blade platform seal

    SciTech Connect

    Zagar, Thomas W.; Schiavo, Anthony L.

    2001-01-01

    A rotating blade group 90 for a turbo-machine having an improved device for sealing the gap 110 between the edges 112,114 of adjacent blade platforms 96,104. The gap 110 between adjacent blades 92,100 is sealed by a seal pin 20 its central portion 110 and by a seal plate 58,60 at each of the front 54 and rear 56 portions. The seal plates 58,60 are inserted into corresponding grooves 62,64 formed in the adjacent edges 112,114 of adjoining blades 92,100 and held in place by end plates 40,42. The end of the seal plates 58,60 may be chamfered 78,80 to improve the seal against the end plate 40,42. The seal pin 20 provides the required damping between the blades 92,100 and the seal plates 58,60 provide improved sealing effectiveness.

  19. Seal design alternatives study

    SciTech Connect

    Van Sambeek, L.L.

    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.

  20. Rotary shaft sealing assembly

    DOEpatents

    Dietle, Lannie L; Schroeder, John E; Kalsi, Manmohan S; Alvarez, Patricio D

    2013-08-13

    A rotary shaft sealing assembly in which a first fluid is partitioned from a second fluid in a housing assembly having a rotary shaft located at least partially within. In one embodiment a lip seal is lubricated and flushed with a pressure-generating seal ring preferably having an angled diverting feature. The pressure-generating seal ring and a hydrodynamic seal may be used to define a lubricant-filled region with each of the seals having hydrodynamic inlets facing the lubricant-filled region. Another aspect of the sealing assembly is having a seal to contain pressurized lubricant while withstanding high rotary speeds. Another rotary shaft sealing assembly embodiment includes a lubricant supply providing a lubricant at an elevated pressure to a region between a lip seal and a hydrodynamic seal with a flow control regulating the flow of lubricant past the lip seal. The hydrodynamic seal may include an energizer element having a modulus of elasticity greater than the modulus of elasticity of a sealing lip of the hydrodynamic seal.

  1. Rotary shaft sealing assembly

    DOEpatents

    Dietle, Lannie L.; Schroeder, John E.; Kalsi, Manmohan S.; Alvarez, Patricio D.

    2010-09-21

    A rotary shaft sealing assembly in which a first fluid is partitioned from a second fluid in a housing assembly having a rotary shaft located at least partially within. In one embodiment a lip seal is lubricated and flushed with a pressure-generating seal ring preferably having an angled diverting feature. The pressure-generating seal ring and a hydrodynamic seal may be used to define a lubricant-filled region with each of the seals having hydrodynamic inlets facing the lubricant-filled region. Another aspect of the sealing assembly is having a seal to contain pressurized lubricant while withstanding high rotary speeds. Another rotary shaft sealing assembly embodiment includes a lubricant supply providing a lubricant at an elevated pressure to a region between a lip seal and a hydrodynamic seal with a flow control regulating the flow of lubricant past the lip seal. The hydrodynamic seal may include an energizer element having a modulus of elasticity greater than the modulus of elasticity of a sealing lip of the hydrodynamic seal.

  2. The modified Cobra Seal

    SciTech Connect

    Ystesund, K.J.; Drayer, D.D.

    1990-01-01

    The Cobra Seal was developed in response to the International Atomic Energy Agency's request for an in situ verifiable seal. The Type E metal cap seal, still widely used by the IAEA, must be removed and returned to Agency headquarters for verification. The Cobra Seal allows an inspector to verify seal identity and integrity on site, without removing the seal. The seal consists of a loop of multi-strand fiber optic cable, which can be routed around or through the object to be sealed, and a seal body that secures the ends of the fiber optic cable. A cutting blade in the seal body randomly cuts a portion of the optical fibers in the cable. After the seal assembly is completed, a reference image is recorded of the unique pattern of light spots produced when the seal face is illuminated. Subsequent photographs of the seal pattern are compared to the original to establish the seal identity and integrity. This paper reviews the improvements and the technology of the cobra seal system. 3 refs., 5 figs.

  3. Corkscrew Seals: Grey Seal (Halichoerus grypus) Infanticide and Cannibalism May Indicate the Cause of Spiral Lacerations in Seals.

    PubMed

    Brownlow, Andrew; Onoufriou, Joseph; Bishop, Amanda; Davison, Nicholas; Thompson, Dave

    2016-01-01

    Large numbers of dead seals with characteristic spiral lesions have been washing ashore around the North Atlantic over the past two decades. Interactions with ship propellers and shark predation have been suggested as the likely causal mechanisms. However, new evidence points towards a more likely candidate: grey seal predation. An adult male grey seal was observed and recorded catching, killing and eating five weaned grey seal pups over a period of one week on the Isle of May, Scotland. A further 9 carcasses found in the same area exhibited similar injuries. Post mortem analysis of lesions indicated the wound characteristics were similar to each other and in 12 of the 14 carcasses analysed, were indistinguishable from carcasses previously attributed to propeller interaction. We therefore propose that most of the seal carcasses displaying spiral lacerations in the UK are caused by grey seal predation. Cases in other locations should be re-evaluated using the scoring system presented here to identify whether grey seal predation is a major cause of mortality in phocid seals.

  4. Corkscrew Seals: Grey Seal (Halichoerus grypus) Infanticide and Cannibalism May Indicate the Cause of Spiral Lacerations in Seals

    PubMed Central

    2016-01-01

    Large numbers of dead seals with characteristic spiral lesions have been washing ashore around the North Atlantic over the past two decades. Interactions with ship propellers and shark predation have been suggested as the likely causal mechanisms. However, new evidence points towards a more likely candidate: grey seal predation. An adult male grey seal was observed and recorded catching, killing and eating five weaned grey seal pups over a period of one week on the Isle of May, Scotland. A further 9 carcasses found in the same area exhibited similar injuries. Post mortem analysis of lesions indicated the wound characteristics were similar to each other and in 12 of the 14 carcasses analysed, were indistinguishable from carcasses previously attributed to propeller interaction. We therefore propose that most of the seal carcasses displaying spiral lacerations in the UK are caused by grey seal predation. Cases in other locations should be re-evaluated using the scoring system presented here to identify whether grey seal predation is a major cause of mortality in phocid seals. PMID:27254025

  5. Nuclear reactor sealing system

    DOEpatents

    McEdwards, James A.

    1983-01-01

    A liquid metal-cooled nuclear reactor sealing system. 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.

  6. Airborne gravity measurement over sea-ice: The western Weddel Sea

    SciTech Connect

    Brozena, J.; Peters, M. ); LaBrecque, J.; Bell, R.; Raymond, C. )

    1990-10-01

    An airborne gravity study of the western Weddel Sea, east of the Antarctic Peninsula, has shown that floating pack-ice provides a useful radar altimetric reference surface for altitude and vertical acceleration corrections surface for alititude and vertical acceleration corrections to airborne gravimetry. Airborne gravimetry provides an important alternative to satellite altimetry for the sea-ice covered regions of the world since satellite alimeters are not designed or intended to provide accurate geoidal heights in areas where significant sea-ice is present within the radar footprint. Errors in radar corrected airborne gravimetry are primarily sensitive to the variations in the second derivative of the sea-ice reference surface in the frequency pass-band of interest. With the exception of imbedded icebergs the second derivative of the pack-ice surface closely approximates that of the mean sea-level surface at wavelengths > 10-20 km. With the airborne method the percentage of ice coverage, the mixture of first and multi-year ice and the existence of leads and pressure ridges prove to be unimportant in determining gravity anomalies at scales of geophysical and geodetic interest, provided that the ice is floating and not grounded. In the Weddell study an analysis of 85 crosstrack miss-ties distributed over 25 data tracks yields an rms error of 2.2 mGals. Significant structural anomalies including the continental shelf and offsets and lineations interpreted as fracture zones recording the early spreading directions within the Weddell Sea are observed in the gravity map.

  7. Renal lesions in Baltic grey seals (Halichoerus grypus) and ringed seals (Phoca hispida botnica).

    PubMed

    Bergman, A; Bergstrand, A; Bignert, A

    2001-11-01

    A severe reduction in the populations of grey and ringed seals in the Baltic occurred during the 1960s and 1970s. Adult animals showed (and still show) a series of lesions inter alia in the female reproductive organs, intestines, integument, kidneys, adrenals, and skulls (the Baltic seal disease complex). The morphology and prevalence of light microscopic changes in the kidneys of 76 grey seals and 29 ringed seals collected in the Baltic proper and the Gulf of Bothnia during 1977-1996 are presented in this report. Specific changes in the glomeruli were diffuse thickening of the capillary walls and the presence of large, rounded, hyaline bodies in the capillary or capsular walls. Specific changes in the distal convoluted tubules and the collecting ducts included focal replacement of the normal epithelium by multilayered cell proliferations. The prevalence and extent of the changes were age-related and thus correlated with the time of exposure to environmental toxicants. The lesions were more conspicuous in Baltic grey seals than in Baltic ringed seals. Similar findings were recorded in 5 grey seals from Swedish zoological gardens. These animals had been fed Baltic fish for most of their lives. Electron microscopy was performed on 5 of the Baltic grey seals and on one of the grey seals from zoological gardens. Electron microscopy results mainly based on findings in one of the Baltic grey seals, included mesangial inter-position in the glomerular capillary walls and the characteristics of intercalated cells in cell proliferations in the distal parts of the nephrons. Eleven grey seals from the Scottish coast and 23 ringed seals from Svalbard served as reference material. None of the reference seals showed the specific lesions described above. The authors propose that organochlorine pollution of the Baltic environment is a factor in the cause of these kidney changes.

  8. C-Band Backscatter Measurements of Winter Sea-Ice in the Weddell Sea, Antarctica

    NASA Technical Reports Server (NTRS)

    Drinkwater, M. R.; Hosseinmostafa, R.; Gogineni, P.

    1995-01-01

    During the 1992 Winter Weddell Gyre Study, a C-band scatterometer was used from the German ice-breaker R/V Polarstern to obtain detailed shipborne measurement scans of Antarctic sea-ice. The frequency-modulated continuous-wave (FM-CW) radar operated at 4-3 GHz and acquired like- (VV) and cross polarization (HV) data at a variety of incidence angles (10-75 deg). Calibrated backscatter data were recorded for several ice types as the icebreaker crossed the Weddell Sea and detailed measurements were made of corresponding snow and sea-ice characteristics at each measurement site, together with meteorological information, radiation budget and oceanographic data. The primary scattering contributions under cold winter conditions arise from the air/snow and snow/ice interfaces. Observations indicate so e similarities with Arctic sea-ice scattering signatures, although the main difference is generally lower mean backscattering coefficients in the Weddell Sea. This is due to the younger mean ice age and thickness, and correspondingly higher mean salinities. In particular, smooth white ice found in 1992 in divergent areas within the Weddell Gyre ice pack was generally extremely smooth and undeformed. Comparisons of field scatterometer data with calibrated 20-26 deg incidence ERS-1 radar image data show close correspondence, and indicate that rough Antarctic first-year and older second-year ice forms do not produce as distinctively different scattering signatures as observed in the Arctic. Thick deformed first-year and second-year ice on the other hand are clearly discriminated from younger undeformed ice. thereby allowing successful separation of thick and thin ice. Time-series data also indicate that C-band is sensitive to changes in snow and ice conditions resulting from atmospheric and oceanographic forcing and the local heat flux environment. Variations of several dB in 45 deg incidence backscatter occur in response to a combination of thermally-regulated parameters

  9. New taeniogyrinid species of sea cucumber from the Weddell Sea (Echinodermata: Holothuroidea: Synaptida).

    PubMed

    O'Loughlin, P Mark; Mackenzie, Melanie; VandenSpiegel, Didier; Griffiths, Huw

    2015-08-05

    The case put by Alexei Smirnov in 2012 is accepted and the order name Synaptida Cuénot is adopted in place of Apodida Brandt. Two new Synaptida species are described for the Weddell Sea in Antarctica with single author O'Loughlin: Sigmodota magdarogera sp. nov. and Taeniogyrus bamberi sp. nov.. A specimen of Sigmodota magnibacula (Massin & Hétérier) is described. A key is provided for the genera and species of Taeniogyrinae that occur south of the Antarctic Convergence.

  10. Ultraviolet absorbance by diatom populations from the Weddell-Scotia Confluence

    SciTech Connect

    Neale, P.J.; Spector, A.M.

    1994-12-31

    Austral spring ozone depletion results in exposure of phytoplankton in the Weddell-Scotia Confluence to enhanced surface ultraviolet-B radiation (UV-B, 280 to 320 nanometers). Since this is an area of high phytoplankton biomass during the early spring, an investigation was made of possible effects of increased UV-B on the phytoplankton productivity during October and November 1993 aboard the R/V Nathaniel B. Palmer (UV-B/Ozone 93). The measurements made during the studies included phytoplankton UV absorbance (this paper) as well as phytoplankton photosynthesis, nutrient uptake, pigment composition, and growth rates. 10 refs., 3 figs.

  11. Compliant Foil Seal Investigations

    NASA Technical Reports Server (NTRS)

    Proctor, Margaret; Delgado, Irebert

    2004-01-01

    Room temperature testing of an 8.5 inch diameter foil seal was conducted in the High Speed, High Temperature Turbine Seal Test Rig at the NASA Glenn Research Center. The seal was operated at speeds up to 30,000 rpm and pressure differentials up to 75 psid. Seal leakage and power loss data will be presented and compared to brush seal performance. The failure of the seal and rotor coating at 30,000 rpm and 15 psid will be presented and future development needs discussed.

  12. Inboard seal mounting

    DOEpatents

    Hayes, John R.

    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.

  13. Energy efficient face seal

    NASA Technical Reports Server (NTRS)

    Sehnal, J.; Sedy, J.; Etsion, I.; Zobens, A.

    1982-01-01

    Torque, face temperature, leakage, and wear of a flat face seal were compared with three coned face seals at pressures up to 2758 kPa and speeds up to 8000 rpm. Axial movement of the mating seal parts was recorded by a digital data acquisition system. The coning of the tungsten carbide primary ring ranged from .51 micro-m to 5.6 micro-m. The torque of the coned face seal balanced to 76.3% was an average 42% lower, the leakage eleven times higher, than that of the standard flat face seal. The reduction of the balance of the coned face seal to 51.3% resulted by decreasing the torque by an additional 44% and increasing leakage 12 to 230 times, depending on the seal shaft speed. No measurable wear was observed on the face of the coned seals.

  14. Sealed container sampling device

    NASA Technical Reports Server (NTRS)

    Hennigan, T. J.

    1969-01-01

    Sampling device, by means of a tapered needle, pierces a sealed container while maintaining the seal and either evacuates or pressurizes the container. This device has many applications in the chemical, preservative and battery-manufacturing industries.

  15. Magnetically Actuated Seal

    NASA Technical Reports Server (NTRS)

    Pinera, Alex

    2013-01-01

    This invention is a magnetically actuated seal in which either a single electromagnet, or multiple electromagnets, are used to control the seal's position. This system can either be an open/ close type of system or an actively controlled system.

  16. Titanium sealing glasses and seals formed therefrom

    DOEpatents

    Brow, R.K.; McCollister, H.L.; Phifer, C.C.; Day, D.E.

    1997-12-02

    Alkaline-earth lanthanoborate sealing-glass compositions containing CaO, La{sub 2}O{sub 3}, B{sub 2}O{sub 3}, TiO{sub 2} and Al{sub 2}O{sub 3} in various combinations of mole-% are provided. These sealing-glass compositions are useful for forming hermetic glass-to-metal seals with titanium and titanium alloys that have a high aqueous durability for component or device applications requiring exposure to moisture, water or body fluids. Particular applications of the titanium sealing-glass compositions include forming glass-to-metal seals for lithium batteries and implanted biomedical devices (e.g. batteries, pacemakers, defibrillators, pumps). 2 figs.

  17. Titanium sealing glasses and seals formed therefrom

    DOEpatents

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

    1997-01-01

    Alkaline-earth lanthanoborate sealing-glass compositions containing CaO, La.sub.2 O.sub.3, B.sub.2 O.sub.3, TiO.sub.2 and Al.sub.2 O.sub.3 in various combinations of mole-% are provided. These sealing-glass compositions are useful for forming hermetic glass-to-metal seals with titanium and titanium alloys that have a high aqueous durability for component or device applications requiring exposure to moisture, water or body fluids. Particular applications of the titanium sealing-glass compositions include forming glass-to-metal seals for lithium batteries and implanted biomedical devices (e.g. batteries, pacemakers, defibrillators, pumps).

  18. Tamper-indicating seal

    DOEpatents

    Fiarman, Sidney; Degen, Michael F.; Peters, Henry F.

    1985-01-01

    There is disclosed a tamper-indicating seal that permits in the field inspection and detection of tampering. Said seal comprises a shrinkable tube having a visible pattern of markings which is shrunk over the item to be sealed, and a second transparent tube, having a second visible marking pattern, which is shrunk over the item and the first tube. The relationship between the first and second set of markings produces a pattern so that the seal may not be removed without detection.

  19. Security seal. [Patent application

    DOEpatents

    Gobeli, G.W.

    1981-11-17

    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.

  20. Turbomachine Interface Sealing

    NASA Technical Reports Server (NTRS)

    Hendricks, Robert C.; Chupp, Raymond E.; Lattime, Scott B.; Steinetz, Bruce M.

    2005-01-01

    Sealing interfaces and coatings, like lubricants, are sacrificial, giving up their integrity for the benefit of the component. Clearance control is a major issue in power systems turbomachine design and operational life. Sealing becomes the most cost-effective way to enhance system performance. Coatings, films, and combined use of both metals and ceramics play a major role in maintaining interface clearances in turbomachine sealing and component life. This paper focuses on conventional and innovative materials and design practices for sealing interfaces.

  1. Resilient Braided Rope Seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor); Kren, Lawrence A. (Inventor)

    1996-01-01

    A resilient braided rope seal for use in high temperature applications. The resilient braided rope seal includes a center core of fibers, a resilient 5 member overbraided by at least one layer of braided sheath fibers tightly packed together. The resilient member adds significant stiffness to the seal while maintaining resiliency. Furthermore, the seal permanent set and hysteresis are greatly reduced. Finally, improved load capabilities are provided.

  2. Topside ionospheric electron temperature and density along the Weddell Sea latitude

    NASA Astrophysics Data System (ADS)

    Liu, J. Y.; Chang, F. Y.; Oyama, K. I.; Kakinami, Y.; Yeh, H. C.; Yeh, T. L.; Jiang, S. B.; Parrot, M.

    2015-01-01

    has been well known that the ionospheric electron density Ne is greater in the summer nighttime than daytime around the Weddell Sea region, which is named Weddell Sea Anomaly (WSA). This paper for the first time reports unusual increases (decreases) of the daytime (nighttime) electron temperature Te at about 830 km altitude over the WSA latitudes probed by Tatiana-2 during December 2009 to January 2010. Concurrent measurements at 660-830 km altitude observed by Tatiana-2, Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER), and Formosa Satellite 3/Constellation Observing System for Meteorology, Ionosphere and Climate (F3/C) reveal the anticorrelation between Te and Ne along the WSA latitudes in the daytime and nighttime. Based on F3/C Ne along the WSA latitudes observed at various local times, the associated Te values are computed. The Tatiana-2 and DEMETER observations as well as the computed results show that Te yield the maximum values over the WSA region during daytime and over the Indian and Atlantic Ocean area during nighttime. The maxima or minima in F3/C Ne and the computed Te reveal eastward phase shifts.

  3. Representation of the Weddell Sea Anomaly obtained by the Swarm constellation

    NASA Astrophysics Data System (ADS)

    Slominska, E.; Blecki, J. S.; Slominski, J.

    2015-12-01

    Recently it has become apparent that the Weddell Sea Anomaly (WSA) and the mid-latitude nighttime summer anomaly (MSNA) are phenomena, which are governed by similar mechanisms. Key questions relate to the fact how do those anomalies set up or how does spatial and altitudinal structure evolve. In-situ registrations of electron density from the Langmuir probe onboard three Swarm satellites are used to study the spatial and temporal evolution of nighttime plasma density enhancements. The study introduces the normalized density difference index INDD to provide global estimates of the phenomenon. The advantage of the index is, that it provides relative values and can be used for further comparison with external missions and exhisting ionospheric models (like IRI). With proposed index, we find signatures the Weddell Sea Anomaly and mid-latitude nighttime summer anomaly in the ionosphere. The study provides evidence that occurrence of the WSA and MSNA is not limited to the local summer conditions but tends to occur in remaining seasons. Analyzed annual trends and spatial pattern of INDD suggest that observed anomalies evince similarity with the behaviour of the equatorial ionosphere. Multi-instrumental analysis based on the Swarm data provide better insight into the WSA phenomenon and should help to acquire full understanding of responsible processes.

  4. Controls on Last Glacial Maximum ice extent in the Weddell Sea embayment, Antarctica

    NASA Astrophysics Data System (ADS)

    Whitehouse, Pippa L.; Bentley, Michael J.; Vieli, Andreas; Jamieson, Stewart S. R.; Hein, Andrew S.; Sugden, David E.

    2017-01-01

    The Weddell Sea sector of the Antarctic Ice Sheet is hypothesized to have made a significant contribution to sea-level rise since the Last Glacial Maximum. Using a numerical flowline model we investigate the controls on grounding line motion across the eastern Weddell Sea and compare our results with field data relating to past ice extent. Specifically, we investigate the influence of changes in ice temperature, accumulation, sea level, ice shelf basal melt, and ice shelf buttressing on the dynamics of the Foundation Ice Stream. We find that ice shelf basal melt plays an important role in controlling grounding line advance, while a reduction in ice shelf buttressing is found to be necessary for grounding line retreat. There are two stable positions for the grounding line under glacial conditions: at the northern margin of Berkner Island and at the continental shelf break. Global mean sea-level contributions associated with these two scenarios are 50 mm and 130 mm, respectively. Comparing model results with field evidence from the Pensacola Mountains and the Shackleton Range, we find it unlikely that ice was grounded at the continental shelf break for a prolonged period during the last glacial cycle. However, we cannot rule out a brief advance to this position or a scenario in which the grounding line retreated behind present during deglaciation and has since re-advanced. Better constraints on past ice sheet and ice shelf geometry, ocean temperature, and ocean circulation are needed to reconstruct more robustly past behavior of the Foundation Ice Stream.

  5. Collapsable seal member

    DOEpatents

    Sherrell, Dennis L.

    1990-01-01

    A hollow, collapsable seal member normally disposed in a natural expanded state offering fail-safe pressure sealing against a seating surface and adapted to be evacuated by a vacuum force for collapsing the seal member to disengage the same from said seating surface.

  6. Skew resisting hydrodynamic seal

    DOEpatents

    Conroy, William T.; Dietle, Lannie L.; Gobeli, Jeffrey D.; Kalsi, Manmohan S.

    2001-01-01

    A novel hydrodynamically lubricated compression type rotary seal that is suitable for lubricant retention and environmental exclusion. Particularly, the seal geometry ensures constraint of a hydrodynamic seal in a manner preventing skew-induced wear and provides adequate room within the seal gland to accommodate thermal expansion. The seal accommodates large as-manufactured variations in the coefficient of thermal expansion of the sealing material, provides a relatively stiff integral spring effect to minimize pressure-induced shuttling of the seal within the gland, and also maintains interfacial contact pressure within the dynamic sealing interface in an optimum range for efficient hydrodynamic lubrication and environment exclusion. The seal geometry also provides for complete support about the circumference of the seal to receive environmental pressure, as compared the interrupted character of seal support set forth in U.S. Pat. Nos. 5,873,576 and 6,036,192 and provides a hydrodynamic seal which is suitable for use with non-Newtonian lubricants.

  7. Seals development and evaluation

    SciTech Connect

    Waddoups, I.G.; Horton, P.R.V.

    1994-08-01

    This paper discusses Sandia`s support of DOE`s domestic seals program. Testing was conducted on several pressure sensitive seals and a few wire loop seals currently in use as well as on a few new seals. The testing on new seals concentrated on loop seals and included two fiber optic seals and a recently available wire loop seal being considered for use. Environmental, handling and vulnerability testing were conducted. The standardized testing approach used and the results of the testing are summarized. The status of evaluations for using higher security active and passive seals for domestic applications is also presented. The conclusion of the testing -of seals currently in use is that, even though there is some variability in their ability to meet all the test criterion, they are all generally acceptable by the test standards used. The motivation for evaluating higher security seals is to ascertain if seals could be used in broader domestic environment and result in improved cost-effectiveness.

  8. Hydraulic System Seal Development.

    DTIC Science & Technology

    1981-06-01

    supplying the seal. Shamban, Fluorocarbon, Parker, Powty, Hercules, Disogrin, Bal Seal Engineering, American Variseal , Tetrafluor, Conover, and Greene...characteristics, as did the Variseal , but both caused minor rod scoring. The Greene Tweed llytrel seal was not considered for further testing becduse

  9. Bioaccumulation of radiocaesium in Arctic seals.

    PubMed

    Carroll, Jolynn; Wolkers, Hans; Andersen, Magnus; Rissanen, Kristina

    2002-12-01

    Seals are high trophic level feeders that bioaccumulate many contaminants to a greater degree than most lower trophic level organisms. Their trophic status in the marine food web and wide-spread distribution make seals useful sentinels of arctic environmental change. The purpose of this investigation is to document the levels and bioaccumulation potential of radiocaesium in high latitude seal species for which data have not previously been available. The study was carried out on harp, ringed, and bearded seals caught north of the island archipelago of Svalbard (82 degrees N) in 1999. The results are then compared with previous studies in order to elucidate factors responsible for bioaccumulation in Arctic seals. Concentrations of 137Cs were determined in muscle, liver and kidney samples from a total of 10 juvenile and one adult seal. The mean concentration in muscle samples for all animals was 0.23 +/- 0.045 Bq/kg f.w. 137Cs concentrations in both liver and kidney samples were near detection limits (approximately 0.2 Bq/kg f.w.). The results are consistent with previous studies indicating low levels of radiocaesium in Arctic seals in response to a long term trend of decreasing levels of 137Cs in the Barents Sea region. Bioconcentration factors (BCFs) estimated for seals from NE Svalbard are low, ranging from 34 to 130. Comparing these values with reported BCFs for Greenland seals from other sectors of the European Arctic, we suggest that the combination of physiological and ecological factors on radiocaesium bioaccumulation is comparable among different Arctic seal populations. The application of this work to Arctic monitoring and assessment programs is discussed.

  10. Fuel cell manifold sealing system

    DOEpatents

    Grevstad, Paul E.; Johnson, Carl K.; Mientek, Anthony P.

    1980-01-01

    A manifold-to-stack seal and sealing method for fuel cell stacks. This seal system solves the problem of maintaining a low leak rate manifold seal as the fuel cell stack undergoes compressive creep. The seal system eliminates the problem of the manifold-to-stack seal sliding against the rough stack surface as the stack becomes shorter because of cell creep, which relative motion destroys the seal. The seal system described herein utilizes a polymer seal frame firmly clamped between the manifold and the stack such that the seal frame moves with the stack. Thus, as the stack creeps, the seal frame creeps with it, and there is no sliding at the rough, tough to seal, stack-to-seal frame interface. Here the sliding is on a smooth easy to seal location between the seal frame and the manifold.

  11. Reconstruction of changes in the Weddell Sea sector of the Antarctic Ice Sheet since the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Hillenbrand, Claus-Dieter; Bentley, Michael J.; Stolldorf, Travis D.; Hein, Andrew S.; Kuhn, Gerhard; Graham, Alastair G. C.; Fogwill, Christopher J.; Kristoffersen, Yngve; Smith, James. A.; Anderson, John B.; Larter, Robert D.; Melles, Martin; Hodgson, Dominic A.; Mulvaney, Robert; Sugden, David E.

    2014-09-01

    The Weddell Sea sector is one of the main formation sites for Antarctic Bottom Water and an outlet for about one fifth of Antarctica's continental ice volume. Over the last few decades, studies on glacial-geological records in this sector have provided conflicting reconstructions of changes in ice-sheet extent and ice-sheet thickness since the Last Glacial Maximum (LGM at ca 23-19 calibrated kiloyears before present, cal ka BP). Terrestrial geomorphological records and exposure ages obtained from rocks in the hinterland of the Weddell Sea, ice-sheet thickness constraints from ice cores and some radiocarbon dates on offshore sediments were interpreted to indicate no significant ice thickening and locally restricted grounding-line advance at the LGM. Other marine geological and geophysical studies concluded that subglacial bedforms mapped on the Weddell Sea continental shelf, subglacial deposits and sediments over-compacted by overriding ice recovered in cores, and the few available radiocarbon ages from marine sediments are consistent with major ice-sheet advance at the LGM. Reflecting the geological interpretations, different ice-sheet models have reconstructed conflicting LGM ice-sheet configurations for the Weddell Sea sector. Consequently, the estimated contributions of ice-sheet build-up in the Weddell Sea sector to the LGM sea-level low-stand of ˜130 m vary considerably. In this paper, we summarise and review the geological records of past ice-sheet margins and past ice-sheet elevations in the Weddell Sea sector. We compile marine and terrestrial chronological data constraining former ice-sheet size, thereby highlighting different levels of certainty, and present two alternative scenarios of the LGM ice-sheet configuration, including time-slice reconstructions for post-LGM grounding-line retreat. Moreover, we discuss consistencies and possible reasons for inconsistencies between the various reconstructions and propose objectives for future research. The aim

  12. SEAL FOR ROTATING SHAFT

    DOEpatents

    Coffman, R.T.

    1957-12-10

    A seal is described for a rotatable shaft that must highly effective when the shaft is not rotating but may be less effective while the shaft is rotating. Weights distributed about a sealing disk secured to the shaft press the sealing disk against a tubular section into which the shiilt extends, and whem the shaft rotates, the centrifugal forces on the weights relieve the pressurc of the sealing disk against the tubular section. This action has the very desirible result of minimizing the wear of the rotating disk due to contact with the tubular section, while affording maximum sealing action when it is needed.

  13. Tamper-indicating seal

    DOEpatents

    Fiarman, S.; Degen, M.F.; Peters, H.F.

    1982-08-13

    There is disclosed a tamper-indicating seal that permits in the field inspection and detection of tampering. Said seal comprises a shrinkable tube having a visible pattern of markings which is shrunk over th item to be sealed, and a second transparent tube, having a second visible marking pattern, which is shrunk over the item and the first tube. The relationship between the first and second set of markings produces a pattern so that the seal may not be removed without detection. The seal is particularly applicable to UF/sub 6/ cylinder valves.

  14. Low Cost, Durable Seal

    SciTech Connect

    Roberts, George; Parsons, Jason; Friedman, Jake

    2010-12-17

    Seal durability is critical to achieving the 2010 DOE operational life goals for both stationary and transportation PEM fuel cell stacks. The seal material must be chemically and mechanically stable in an environment consisting of aggressive operating temperatures, humidified gases, and acidic membranes. The seal must also be producible at low cost. Currentlyused seal materials do not meet all these requirements. This project developed and demonstrated a high consistency hydrocarbon rubber seal material that was able to meet the DOE technical and cost targets. Significant emphasis was placed on characterization of the material and full scale molding demonstrations.

  15. Rotary kiln seal

    SciTech Connect

    Drexler, Robert L.

    1992-01-01

    A rotary seal used to prevent the escape of contaminates from a rotating kiln incinerator. The rotating seal combines a rotating disc plate which is attached to the rotating kiln shell and four sets of non-rotating carbon seal bars housed in a primary and secondary housing and which rub on the sides of the disc. A seal air system is used to create a positive pressure in a chamber between the primary and secondary seals to create a positive air flow into the contaminated gas chamber. The seal air system also employs an air inlet located between the secondary and tertiary seals to further insure that no contaminates pass the seal and enter the external environment and to provide makeup air for the air which flows into the contaminated gas chamber. The pressure exerted by the seal bars on the rotating disc is controlled by means of a preload spring. The seal is capable of operating in a thermally changing environment where the both radial expansion and axial movement of the rotating kiln do not result in the failure of the seal.

  16. Sea ice concentration temporal variability over the Weddell Sea and its relationship with tropical sea surface temperature

    USGS Publications Warehouse

    Barreira, S.; Compagnucci, R.

    2007-01-01

    Principal Components Analysis (PCA) in S-Mode (correlation between temporal series) was performed on sea ice monthly anomalies, in order to investigate which are the main temporal patterns, where are the homogenous areas located and how are they related to the sea surface temperature (SST). This analysis provides 9 patterns (4 in the Amundsen and Bellingshausen Seas and 5 in the Weddell Sea) that represent the most important temporal features that dominated sea ice concentration anomalies (SICA) variability in the Weddell, Amundsen and Bellingshausen Seas over the 1979-2000 period. Monthly Polar Gridded Sea Ice Concentrations data set derived from satellite information generated by NASA Team algorithm and acquired from the National Snow and Ice Data Center (NSIDC) were used. Monthly means SST are provided by the National Center for Environmental Prediction reanalysis. The first temporal pattern series obtained by PCA has its homogeneous area located at the external region of the Weddell and Bellingshausen Seas and Drake Passage, mostly north of 60°S. The second region is centered in 30°W and located at the southeast of the Weddell. The third area is localized east of 30°W and north of 60°S. South of the first area, the fourth PC series has its homogenous region, between 30° and 60°W. The last area is centered at 0° W and south of 60°S. Correlation charts between the five Principal Components series and SST were performed. Positive correlations over the Tropical Pacific Ocean were found for the five PCs when SST series preceded SICA PC series. The sign of the correlation could relate the occurrence of an El Niño/Southern Oscillation (ENSO) warm (cold) event with posterior positive (negative) anomalies of sea ice concentration over the Weddell Sea.

  17. Anthropogenic carbon estimates in the Weddell Sea using an optimized CFC based transit time distribution approach

    NASA Astrophysics Data System (ADS)

    Huhn, Oliver; Hauck, Judith; Hoppema, Mario; Rhein, Monika; Roether, Wolfgang

    2010-05-01

    We use a 20 year time series of chlorofluorocarbon (CFC) observations along the Prime Meridian to determine the temporal evolution of anthropogenic carbon (Cant) in the two deep boundary currents which enter the Weddell Basin in the south and leave it in the north. The Cant is inferred from transit time distributions (TTDs), with parameters (mean transit time and dispersion) adjusted to the observed mean CFC histories in these recently ventilated deep boundary currents. We optimize that "classic" TTD approach by accounting for water exchange of the boundary currents with an old but not CFC and Cant free interior reservoir. This reservoir in turn, is replenished by the boundary currents, which we parameterize as first order mixing. Furthermore, we account for the time-dependence of the CFC and Cant source water saturation. A conceptual model of an ideal saturated mixed layer and exchange with adjacent water is adjusted to observed CFC saturations in the source regions. The time-dependence for the CFC saturation appears to be much weaker than for Cant. We find a mean transit time of 14 years and an advection/dispersion ratio of 5 for the deep southern boundary current. For the northern boundary current we find a mean transit time of 8 years and a much advection/dispersion ratio of 140. The fractions directly supplied by the boundary currents are in both cases in the order of 10%, while 90% are admixed from the interior reservoirs, which are replenished with a renewal time of about 14 years. We determine Cant ~ 11 umol/kg (reference year 2006) in the deep water entering the Weddell Sea in the south (~2.1 Sv), and 12 umol/kg for the deep water leaving the Weddell Sea in the north (~2.7 Sv). These Cant estimates are, however, upper limits, considering that the Cant source water saturation is likely to be lower than that for the CFCs. Comparison with Cant intrusion estimates based on extended multiple linear regression (using potential temperature, salinity, oxygen, and

  18. COMPRESSION SEAL AND SEALING MATERIAL THEREFOR

    DOEpatents

    Branin, T.G.

    1962-05-29

    This patent relates to compression seal and more particularly to a seaiing material therefor. The sealing surface is a coating consisting of alternate layers of gold and of a non-gold metal having similar plastic flow properties under pressure as gold. The coating is substantially free from oxidation effects when exposed to ambient atmosphere and does not become brittle when worked, as in a valve. (AEC)

  19. Shaft seal system

    DOEpatents

    Kapich, Davorin D.

    1985-01-01

    A shaft seal system is disclosed for isolating two regions of different fluid mediums through which a rotatable shaft extends. The seal system includes a seal housing through which the shaft extends and which defines an annular land and an annular labyrinth both of which face on the shaft so that each establishes a corresponding fluid sealing annulus. A collection cavity is formed in communication with the annular sealing spaces, and fluids compatible with the fluids in each of the two regions to be isolated are introduced, respectively, into the annular sealing spaces and collected in the collection cavity from which the fluid mixture is removed and passed to a separator which separates the fluids and returns them to their respective annular sealing spaces in a recycling manner. In the illustrated embodiment, the isolated fluid mediums comprise a liquid region and a gas region. Gas is removed from the gas region and passed through a purifier and a gas pump operative to introduce the purified gas through the labyrinth sealing annulus to the collection cavity. After passing to the separator, the separated gas is passed through a dryer from which the dried gas is caused to pass through the labyrinth sealing annulus into the collection cavity independently of the purified gas so as to insure isolation of the gas region in the event of sealing gas pump malfunction.

  20. Phocid seals, seal lice and heartworms: a terrestrial host-parasite system conveyed to the marine environment.

    PubMed

    Leidenberger, Sonja; Harding, Karin; Härkönen, Tero

    2007-10-15

    Adaptation of pinnipeds to the marine habitat imposed parallel evolutions in their parasites. Ancestral pinnipeds must have harboured sucking lice, which were ancestors of the seal louse Echinophthirius horridus. The seal louse is one of the few insects that successfully adjusted to the marine environment. Adaptations such as keeping an air reservoir and the ability to hold on to and move on the host were necessary, as well as an adjustment of their life cycle to fit the diving habits of their host. E. horridus are confined to the Northern Hemisphere and have been reported from 9 species of northern phocids belonging to 4 genera, including land-locked seal species. The transmission from seal to seal is only possible when animals are hauled-out on land or ice. Lice are rarely found on healthy adult seals, but frequently on weak and young animals. The seal louse is suggested to play an important role as an intermediate host transmitting the heartworm Acanthocheilonema spirocauda among seals. However, the evidence is restricted to a single study where the first 3 larval stages of the heartworm were shown to develop in the louse. The fourth-stage larvae develop in the blood system of seals and eventually transform into the adult stage that matures in the heart. Since all other studies failed to confirm the presence of heartworm larvae in seal lice, other unknown intermediate hosts could be involved in the transmission of the heartworm. Transplacental transmission of microfilariae in seals has been suggested as an additional possibility, but is not likely to be important since the occurrence of heartworms in adult seals is very rare compared with juveniles. Furthermore, there are no findings of the first 3 larval stages in seals. This review shows that the heartworm infects nearly the same species of seals as the seal louse, except for the grey seal Halichoerus grypus, where the heartworm is absent. Prevalence and intensity of infection differ among regions in the

  1. Contracting/expanding self-sealing cryogenic tube seals

    NASA Technical Reports Server (NTRS)

    Jia, Lin X. (Inventor)

    1997-01-01

    Contracting/expanding self-sealing cryogenic tube seals are disclosed which use the different properties of thermal contraction and expansion of selected dissimilar materials in accord with certain design criteria to yield self-tightening seals via sloped-surface sealing. The seals of the subject invention are reusable, simple to assemble, and adaptable to a wide variety of cryogenic applications.

  2. Free-drifting icebergs: hot spots of chemical and biological enrichment in the Weddell Sea.

    PubMed

    Smith, Kenneth L; Robison, Bruce H; Helly, John J; Kaufmann, Ronald S; Ruhl, Henry A; Shaw, Timothy J; Twining, Benjamin S; Vernet, Maria

    2007-07-27

    The proliferation of icebergs from Antarctica over the past decade has raised questions about their potential impact on the surrounding pelagic ecosystem. Two free-drifting icebergs, 0.1 and 30.8 square kilometers in aerial surface area, and the surrounding waters were sampled in the northwest Weddell Sea during austral spring 2005. There was substantial enrichment of terrigenous material, and there were high concentrations of chlorophyll, krill, and seabirds surrounding each iceberg, extending out to a radial distance of approximately 3.7 kilometers. Extrapolating these results to all icebergs in the same size range, with the use of iceberg population estimates from satellite surveys, indicates that they similarly affect 39% of the surface ocean in this region. These results suggest that free-drifting icebergs can substantially affect the pelagic ecosystem of the Southern Ocean and can serve as areas of enhanced production and sequestration of organic carbon to the deep sea.

  3. Ocean drilling program for Georges Bank, Eastern Pacific Rise, Mid American Trench, and Antarctica (Weddell sea)

    SciTech Connect

    Not Available

    1985-06-01

    The draft form of an environmental impact statement (EPA No. 850262D) on a proposed 10-year international ocean drilling program describes plans for drilling in the Georges Bank, Eastern Pacific Rise, Mid-American Trench, and Weddell Sea areas. Core samples from the ocean floor in the four study areas will examine oceanic crust, active and passive margins, and ocean paleoenvironment. The program would generate information on sea floor spreading, plate tectonics, the structure of the earth's interior, evolution of ocean life, climatic changes through time, and the structure of the planet. Negative impacts would be damage to the sea floor, drilling muds, possible gas or brine blowouts, and a possible effect on the sonar or hearing of marine mammals. Legal mandates for the impact statement are laws addressing water pollution, international conventions of the sea, and protection for marine life.

  4. High productivity in an ice melting hot spot at the eastern boundary of the Weddell Gyre

    NASA Astrophysics Data System (ADS)

    Geibert, W.; Assmy, P.; Bakker, D. C. E.; Hanfland, C.; Hoppema, M.; Pichevin, L. E.; Schröder, M.; Schwarz, J. N.; Stimac, I.; Usbeck, R.; Webb, A.

    2010-09-01

    The Southern Ocean (SO) plays a key role in modulating atmospheric CO2 via physical and biological processes. However, over much of the SO, biological activity is iron-limited. New in situ data from the Antarctic zone south of Africa in a region centered at ˜20°E-25°E reveal a previously overlooked region of high primary production, comparable in size to the northwest African upwelling region. Here, sea ice together with enclosed icebergs is channeled by prevailing winds to the eastern boundary of the Weddell Gyre, where a sharp transition to warmer waters causes melting. This cumulative melting provides a steady source of iron, fuelling an intense phytoplankton bloom that is not fully captured by monthly satellite production estimates. These findings imply that future changes in sea-ice cover and dynamics could have a significant effect on carbon sequestration in the SO.

  5. Ocean glider observations of iceberg-enhanced biological production in the northwestern Weddell Sea

    NASA Astrophysics Data System (ADS)

    Biddle, Louise C.; Kaiser, Jan; Heywood, Karen J.; Thompson, Andrew F.; Jenkins, Adrian

    2015-01-01

    Icebergs affect local biological production around Antarctica. We used an ocean glider to observe the effects of a large iceberg that was advected by the Antarctic Slope Current along the continental slope in the northwestern Weddell Sea in early 2012. The high-resolution glider data reveal a pronounced effect of the iceberg on ocean properties, with oxygen concentrations of (13 ± 4) μmol kg-1 higher than levels in surrounding waters, which are most likely due to positive net community production. This response was confined to three areas of water in the direct vicinity of the iceberg track, each no larger than 2 km2. Our findings suggest that icebergs have an impact on Antarctic production presumably through local micronutrient injections, on a scale smaller than typical satellite observations of biological production in the Southern Ocean.

  6. Noble gas tracers of ventilation during deep-water formation in the Weddell Sea

    NASA Astrophysics Data System (ADS)

    Nicholson, D. P.; Khatiwala, S.; Heimbach, P.

    2016-05-01

    To explore the dynamics and implications of incomplete air-sea equilibration during the formation of abyssal water masses, we simulated noble gases in the Estimating the Circulation & Climate of the Ocean (ECCO) global ocean state estimate. A novel computation approach utilizing a matrix-free Newton-Krylov (MFNK) scheme was applied to quickly compute the periodic seasonal solutions for noble gas tracers. MFNK allows for quick computation of a cyclo-stationary solution for tracers (i.e., a spun-up, repeating seasonal cycle), which would otherwise be computationally infeasible due to the long time scale of dynamic adjustment of the abyssal ocean (1000’s of years). A suite of experiments isolates individual processes, including atmospheric pressure effects, the solubility pump and air-sea bubble fluxes. In addition to these modeled processes, a volumetric contribution of 0.28 ± 0.07% of glacial melt water is required to reconcile deep-water observations in the Weddell Sea. Another primary finding of our work is that the saturation anomaly of heavy noble gases in model simulations is in excess of two-fold more negative than is suggested from Weddell Sea observations. This result suggests that model water masses are insufficiently ventilated prior to subduction and thus there is insufficient communication between atmosphere and ocean at high latitudes. The discrepancy between noble gas observations and ECCO simulations highlights that important inadequacies remain in how we model high-latitude ventilation with large implications for the oceanic uptake and storage of carbon.

  7. Layered seal for turbomachinery

    DOEpatents

    Sarawate, Neelesh Nandkumar; Morgan, Victor John; Weber, David Wayne

    2015-11-20

    The present application provides seal assemblies for reducing leakages between adjacent components of turbomachinery. The seal assemblies may include outer shims, and at least a portion of the outer shims may be substantially impervious. At least one of the outer shims may be configured for sealing engagement with seal slots of the adjacent components. The seal assemblies may also include at least one of an inner shim and a filler layer positioned between the outer shims. The at least one inner shim may be substantially solid and the at least one filler layer may be relatively porous. The seal assemblies may be sufficiently flexible to account for misalignment between the adjacent components, sufficiently stiff to meet assembly requirements, and sufficiently robust to operating meet requirements associated with turbomachinery.

  8. Seals Code Development Workshop

    NASA Technical Reports Server (NTRS)

    Hendricks, Robert C. (Compiler); Liang, Anita D. (Compiler)

    1996-01-01

    Seals Workshop of 1995 industrial code (INDSEAL) release include ICYL, GCYLT, IFACE, GFACE, SPIRALG, SPIRALI, DYSEAL, and KTK. The scientific code (SCISEAL) release includes conjugate heat transfer and multidomain with rotordynamic capability. Several seals and bearings codes (e.g., HYDROFLEX, HYDROTRAN, HYDROB3D, FLOWCON1, FLOWCON2) are presented and results compared. Current computational and experimental emphasis includes multiple connected cavity flows with goals of reducing parasitic losses and gas ingestion. Labyrinth seals continue to play a significant role in sealing with face, honeycomb, and new sealing concepts under investigation for advanced engine concepts in view of strict environmental constraints. The clean sheet approach to engine design is advocated with program directions and anticipated percentage SFC reductions cited. Future activities center on engine applications with coupled seal/power/secondary flow streams.

  9. Dynamic sealing principles

    NASA Technical Reports Server (NTRS)

    Zuk, J.

    1976-01-01

    The fundamental principles governing dynamic sealing operation are discussed. Different seals are described in terms of these principles. Despite the large variety of detailed construction, there appear to be some basic principles, or combinations of basic principles, by which all seals function, these are presented and discussed. Theoretical and practical considerations in the application of these principles are discussed. Advantages, disadvantages, limitations, and application examples of various conventional and special seals are presented. Fundamental equations governing liquid and gas flows in thin film seals, which enable leakage calculations to be made, are also presented. Concept of flow functions, application of Reynolds lubrication equation, and nonlubrication equation flow, friction and wear; and seal lubrication regimes are explained.

  10. Mechanically expandable annular seal

    DOEpatents

    Gilmore, R.F.

    1983-07-19

    A mechanically expandable annular reusable seal assembly to form an annular hermetic barrier between two stationary, parallel, and planar containment surfaces is described. A rotatable ring, attached to the first surface, has ring wedges resembling the saw-tooth array of a hole saw. Matching seal wedges are slidably attached to the ring wedges and have their motion restricted to be perpendicular to the second surface. Each seal wedge has a face parallel to the second surface. An annular elastomer seal has a central annular region attached to the seal wedges' parallel faces and has its inner and outer circumferences attached to the first surface. A rotation of the ring extends the elastomer seal's central region perpendicularly towards the second surface to create the fluid tight barrier. A counter rotation removes the barrier. 6 figs.

  11. Mechanically expandable annular seal

    DOEpatents

    Gilmore, Richard F.

    1983-01-01

    A mechanically expandable annular reusable seal assembly to form an annular hermetic barrier between two stationary, parallel, and planar containment surfaces. A rotatable ring, attached to the first surface, has ring wedges resembling the saw-tooth array of a hole saw. Matching seal wedges are slidably attached to the ring wedges and have their motion restricted to be perpendicular to the second surface. Each seal wedge has a face parallel to the second surface. An annular elastomer seal has a central annular region attached to the seal wedges' parallel faces and has its inner and outer circumferences attached to the first surface. A rotation of the ring extends the elastomer seal's central region perpendicularly towards the second surface to create the fluidtight barrier. A counterrotation removes the barrier.

  12. Sodium sulfur battery seal

    DOEpatents

    Mikkor, Mati

    1981-01-01

    This disclosure is directed to an improvement in a sodium sulfur battery construction in which a seal between various battery compartments is made by a structure in which a soft metal seal member is held in a sealing position by holding structure. A pressure applying structure is used to apply pressure on the soft metal seal member when it is being held in sealing relationship to a surface of a container member of the sodium sulfur battery by the holding structure. The improvement comprises including a thin, well-adhered, soft metal layer on the surface of the container member of the sodium sulfur battery to which the soft metal seal member is to be bonded.

  13. Compliant Turbomachine Sealing

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Braun, M. J.; Deng, D.; Hendricks, J. A.

    2011-01-01

    Sealing interface materials and coatings are sacrificial, giving up their integrity for the benefit of the component. Seals that are compliant while still controlling leakage, dynamics, and coolant flows are sought to enhance turbomachine performance. Herein we investigate the leaf-seal configuration. While the leaf seal is classified as contacting, a ready modification using the leaf-housing arrangement in conjunction with an interface film rider (a bore seal, for example) provides for a film-riding noncontact seal. The leaf housing and leaf elements can be made from a variety of materials from plastic to ceramic. Four simplistic models are used to identify the physics essential to controlling leakage. Corroborated by CFD, these results provide design parameters for applications to within reasonable engineering certainty. Some potential improvements are proposed.

  14. Damped flexible seal

    SciTech Connect

    DuBois, Neil J.; Amaral, Antonio M.

    1992-10-27

    A damped flexible seal assembly for a torpedo isolates the tailcone thereof rom vibrational energy present in the drive shaft assembly. A pair of outside flanges, each of which include an inwardly facing groove and an O-ring constrained therein, provide a watertight seal against the outer non-rotating surface of the drive shaft assembly. An inside flange includes an outwardly-facing groove and an O-ring constrained therein, and provides a watertight seal against the inner surface of the tail cone. Two cast-in-place elastomeric seals provide a watertight seal between the flanges and further provide a damping barrier between the outside flanges and the inside flanges for damping vibrational energy present in the drive shaft assembly before the energy can reach the tailcone through the seal assembly.

  15. Inflatable traversing probe seal

    NASA Technical Reports Server (NTRS)

    Trimarchi, Paul A.

    1991-01-01

    An inflatable seal acts as a pressure-tight zipper to provide traversing capability for instrumentation rakes and probes. A specially designed probe segment with a teardrop cross-section in the vicinity of the inflatable seal minimizes leakage at the interface. The probe is able to travel through a lengthwise slot in a pressure vessel or wind tunnel section, while still maintaining pressure integrity. The design uses two commercially available inflatable seals, opposing each other, to cover the probe slot in a wind tunnel wall. Proof-of-concept tests were conducted at vessel pressures up to 30 psig, with seals inflated to 50 psig, showing no measurable leakage along the seal's length or around the probe teardrop cross-section. This seal concept can replace the existing technology of sliding face plate/O-ring systems in applications where lengthwise space is limited.

  16. The Lost Seal: A Scientific Children's Book from the Long Term Ecological Research (LTER) Network Schoolyard Program

    NASA Astrophysics Data System (ADS)

    Sommer, S.

    2006-12-01

    A true story about an encounter between LTER scientists and a young Weddell seal in the Dry Valleys of Antarctica has inspired a new children's book, The Lost Seal. Written by Diane McKnight, professor of environmental engineering at the University of Colorado and fellow of the Institute of Arctic and Alpine Research (INSTAAR), the book is an engaging introduction to Antarctica and the Dry Valleys. McKnight tells the story of the seal in the context of the harsh Dry Valleys environment and the LTER scientific work taking place there. The book includes information about hydrology, limnology, and microbial ecology. Artwork by professional illustrator Dorothy Emerling connects young readers with the environment and wildlife of Antarctica, while artwork from children in Australia, England, New Zealand, and the United States emphasizes the international nature of interest in the Antarctic. The Lost Seal has been published in time for the International Polar Year and is the second book in the NSF-supported LTER children's book series. The Lost Seal is at the center of many outreach activities: classroom activities in four countries; a colorful children's book distributed to schools and sold in national parks; a teacher's edition of the book; curriculum development in Boulder, Colorado schools; an educational web site (www.mcmlter.org/lostseal); and workshops for scientists on how to create scientific children's literature. This session will describe the various outreach activities and show how lessons learned from publication of The Lost Seal might apply to other IPY outreach efforts.

  17. Liquid Annular Seal Research

    NASA Technical Reports Server (NTRS)

    Palazzolo, Alan B.; Venkataraman, Balaji; Padavala, Sathya S.; Ryan, Steve; Vallely, Pat; Funston, Kerry

    1996-01-01

    This paper highlights the accomplishments on a joint effort between NASA - Marshall Space Flight Center and Texas A and M University to develop accurate seal analysis software for use in rocket turbopump design, design audits and trouble shooting. Results for arbitrary clearance profile, transient simulation, thermal effects solution and flexible seal wall model are presented. A new solution for eccentric seals based on cubic spline interpolation and ordinary differential equation integration is also presented.

  18. Compliant seal development

    NASA Technical Reports Server (NTRS)

    Hendricks, Robert C.

    1993-01-01

    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.

  19. Seals Flow Code Development

    NASA Technical Reports Server (NTRS)

    1991-01-01

    In recognition of a deficiency in the current modeling capability for seals, an effort was established by NASA to develop verified computational fluid dynamic concepts, codes, and analyses for seals. The objectives were to develop advanced concepts for the design and analysis of seals, to effectively disseminate the information to potential users by way of annual workshops, and to provide experimental verification for the models and codes under a wide range of operating conditions.

  20. Grayloc seal static tests

    SciTech Connect

    Leisher, W.B.; Biffle, J.H.

    1983-02-01

    A series of evaluation tests was performed on Grayloc seals. Helium service and standard seals, size 292, were used. Measurements were made of axial force and motion, diameter, hoop and axial strain, and helium leak rate. Leak rates were in the 10/sup -6/ atm cc/s range for the helium service seals. Pretest analytical calculations agreed reasonably well with measured makeup forces and deflections.

  1. Repository seals requirements study

    SciTech Connect

    1997-11-03

    The Yucca Mountain Site Characterization Project, managed by the Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) is conducting investigations to support the Viability Assessment and the License Application for a high-level nuclear waste repository at Yucca Mountain, Nevada. The sealing subsystem is part of the Yucca Mountain Waste Isolation System. The Yucca Mountain Site Characterization Project is currently evaluating the role of the sealing subsystem (shaft, ramp and exploratory borehole seals) in achieving the overall performance objectives for the Waste Isolation System. This report documents the results of those evaluations. This report presents the results of a repository sealing requirements study. Sealing is defined as the permanent closure of the shafts, ramps, and exploratory boreholes. Sealing includes those components that would reduce potential inflows above the repository, or that would divert flow near the repository horizon to allow vertical infiltration to below the repository. Sealing of such features as emplacement drifts was not done in this study because the current capability to calculate fracture flow into the drifts is not sufficiently mature. The objective of the study is to provide water or air flow performance based requirements for shafts, ramps, and exploratory boreholes located near the repository. Recommendations, as appropriate, are provided for developing plans, seals component testing, and other studies relating to sealing.

  2. Foil Face Seal Testing

    NASA Technical Reports Server (NTRS)

    Munson, John

    2009-01-01

    In the seal literature you can find many attempts by various researchers to adapt film riding seals to the gas turbine engine. None have been successful, potential distortion of the sealing faces is the primary reason. There is a film riding device that does accommodate distortion and is in service in aircraft applications, namely the foil bearing. More specifically a foil thrust bearing. These are not intended to be seals, and they do not accommodate large axial movement between shaft & static structure. By combining the 2 a unique type of face seal has been created. It functions like a normal face seal. The foil thrust bearing replaces the normal primary sealing surface. The compliance of the foil bearing allows the foils to track distortion of the mating seal ring. The foil seal has several perceived advantages over existing hydrodynamic designs, enumerated in the chart. Materials and design methodology needed for this application already exist. Also the load capacity requirements for the foil bearing are low since it only needs to support itself and overcome friction forces at the antirotation keys.

  3. Bidirectional Brush Seals

    NASA Technical Reports Server (NTRS)

    Hendricks, Robert C.; Wilson, Jack; Wu, Tom; Flower, Ralph

    1997-01-01

    Presented is a study of the use of a set of I.D./O.D. bidirectional press seals to reduce the leakage losses in a wave rotor. Relative to the baseline configuration, data indicate the use of brush seals enhanced wave rotor efficiency from 36 to 45 percent at low leakages (small rotor endwall gap spacings) and from 15 to 33 percent at high leakages (larger endwall gap spacings). These brush seals are capable of sealing positive or negative pressure drops with respect to the axial direction. Surface tribology for these tests suggested little evidence of grooving although the bristles appeared polished.

  4. Liquid zone seal

    DOEpatents

    Klebanoff, Leonard E.

    2001-01-01

    A seal assembly that provides a means for establishing multiple pressure zones within a system. The seal assembly combines a plate extending from the inner wall of a housing or inner enclosure that intersects with and is immersed in the fluid contained in a well formed in a tray contained within the enclosure. The fluid is a low vapor pressure oil, chemically inert and oxidation resistant. The use of a fluid as the sealing component provides a seal that is self-healing and mechanically robust not subject to normal mechanical wear, breakage, and formation of cracks or pinholes and decouples external mechanical vibrations from internal structural members.

  5. High Pressure Hydraulic Seals

    DTIC Science & Technology

    1988-09-01

    looked XV2690-18D Ring good, front seal XP2714-4 Backups, (ML1841) cracked. American Variseal /Shamban 100,493 110cc leakage on P/N AS-1272 rear seal...BACKUPS SEVERELY SEAL CEC 49S1C-214-DS DETERIORATED. 38. AMERICAN VARISEAL / TESTED THROUGH 100.493 CYCLES. EXCESSIVE LEAKAGE 110 CC SHAMBAN ON REAR SEAL...California 90230 Koppers Company, Inc. Baltimore, Maryland 21203 American Variseal Corp. Broomfield, Colorado 80020 The test actuator parts were serialized

  6. Decline of deep and bottom water ventilation and slowing down of anthropogenic carbon storage in the Weddell Sea, 1984-2011

    NASA Astrophysics Data System (ADS)

    Huhn, Oliver; Rhein, Monika; Hoppema, Mario; van Heuven, Steven

    2013-06-01

    We use a 27 year long time series of repeated transient tracer observations to investigate the evolution of the ventilation time scales and the related content of anthropogenic carbon (Cant) in deep and bottom water in the Weddell Sea. This time series consists of chlorofluorocarbon (CFC) observations from 1984 to 2008 together with first combined CFC and sulphur hexafluoride (SF6) measurements from 2010/2011 along the Prime Meridian in the Antarctic Ocean and across the Weddell Sea. Applying the Transit Time Distribution (TTD) method we find that all deep water masses in the Weddell Sea have been continually growing older and getting less ventilated during the last 27 years. The decline of the ventilation rate of Weddell Sea Bottom Water (WSBW) and Weddell Sea Deep Water (WSDW) along the Prime Meridian is in the order of 15-21%; the Warm Deep Water (WDW) ventilation rate declined much faster by 33%. About 88-94% of the age increase in WSBW near its source regions (1.8-2.4 years per year) is explained by the age increase of WDW (4.5 years per year). As a consequence of the aging, the Cant increase in the deep and bottom water formed in the Weddell Sea slowed down by 14-21% over the period of observations.

  7. Brucella antibody seroprevalence in Antarctic seals (Arctocephalus gazella, Leptonychotes weddellii and Mirounga leonina).

    PubMed

    Jensen, Silje-Kristin; Nymo, Ingebjørg Helena; Forcada, Jaume; Hall, Ailsa; Godfroid, Jacques

    2013-09-03

    Brucellosis is a worldwide infectious zoonotic disease caused by Gram-negative bacteria of the genus Brucella, and Brucella infections in marine mammals were first reported in 1994. A serosurvey investigating the presence of anti-Brucella antibodies in 3 Antarctic pinniped species was undertaken with a protein A/G indirect enzyme-linked immunosorbent assay (iELISA) and the Rose Bengal test (RBT). Serum samples from 33 Weddell seals Leptonychotes weddelli were analysed, and antibodies were detected in 8 individuals (24.2%) with the iELISA and in 21 (65.6%) with the RBT. We tested 48 southern elephant seal Mirounga leonina sera and detected antibodies in 2 animals (4.7%) with both the iELISA and the RBT. None of the 21 Antarctic fur seals Arctocephalus gazella was found positive. This is the first report of anti-Brucella antibodies in southern elephant seals. The potential impact of Brucella infection in pinnipeds in Antarctica is not known, but Brucella spp. are known to cause abortion in terrestrial species and cetaceans. Our findings suggest that Brucella infection in pinnipeds is present in the Antarctic, but to date B. pinnipedialis has not been isolated from any Antarctic pinniped species, leaving the confirmation of infection pending.

  8. Resilient Braided Rope Seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor); Kren, Lawrence A. (Inventor)

    2000-01-01

    A resilient braided rope seal for use in high temperature applications includes a center core of fibers. a resilient canted spring member supporting the core and at least one layer of braided sheath fibers tightly packed together overlying the spring member. The seal provides both improved load bearing and resiliency. Permanent set and hysteresis are greatly reduced.

  9. Seal ring installation tool

    NASA Technical Reports Server (NTRS)

    Haselmaier, L. Haynes (Inventor)

    2004-01-01

    A seal ring tool that allows an installer to position a primary seal ring between hub ends of pipe flanges that are being assembled together. The tool includes a pivoting handle member and extension arms attached to the pivoting handle member. The ends of the arms have side indentation type longitudinal grooves angled toward one another for holding the primary seal ring in place between the hubs of respective pipes that are to be attached together. The arms of the tool can also have flat sides that can be used to abut against an optional second larger seal that is supported within a groove in one of the hub ends so that the second hub end can then be moved against the other side of the primary seal ring. Once the seal ring is positioned between the pipe hubs, the pipe hubs can be moved about the seal ring due to the flat sides of the arms of the tool. The tool eliminates the chances of damaging and contaminating seal rings being installed within pipe hubs that are being attached to one another.

  10. Pneumatic stowing seals mines

    SciTech Connect

    Brezovec, D.

    1983-11-01

    A pneumatic stowing technique has been used in the US to seal entries to abandoned mines. Limestone mixed with dry cement or bentonite is blown into the opening. Sealing can be accomplished in much less time than with traditional concrete block/clay plug methods.

  11. Seals and Scrolls.

    ERIC Educational Resources Information Center

    Macaulay, Sara Grove

    2000-01-01

    Describes an art unit in which students sculpt a signature seal out of clay and use Chinese brush painting techniques to paint a scroll. Discusses the seal and its historical use in China. Lists materials needed and explains the procedure. (CMK)

  12. Sodium sulfur battery seal

    DOEpatents

    Topouzian, Armenag

    1980-01-01

    This invention is directed to a seal for a sodium sulfur battery in which a flexible diaphragm sealing elements respectively engage opposite sides of a ceramic component of the battery which separates an anode compartment from a cathode compartment of the battery.

  13. Repository seals requirement study

    SciTech Connect

    1997-11-03

    The Yucca Mountain Site Characterization Project, managed by the Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) is conducting investigations to support the Viability Assessment and the License Application for a high-level nuclear waste repository at Yucca Mountain, Nevada. The sealing subsystem is part of the Yucca Mountain Waste Isolation System. The Yucca Mountain Site Characterization Project is currently evaluating the role of the sealing subsystem (shaft, ramp and exploratory borehole seals) in achieving the overall performance objectives for the Waste Isolation System. This report documents the results of those evaluations. The objective of the study is to provide water or air flow performance based requirements for shafts, ramps, and exploratory boreholes located near the repository. Recommendations, as appropriate, are provided for developing plans, seals component testing, and other studies relating to sealing.

  14. Sealing in Turbomachinery

    NASA Technical Reports Server (NTRS)

    Chupp, Raymond E.; Hendricks, Robert C.; Lattime, Scott B.; Steinetz, Bruce M.

    2006-01-01

    Clearance control is of paramount importance to turbomachinery designers and is required to meet today's aggressive power output, efficiency, and operational life goals. Excessive clearances lead to losses in cycle efficiency, flow instabilities, and hot gas ingestion into disk cavities. Insufficient clearances limit coolant flows and cause interface rubbing, overheating downstream components and damaging interfaces, thus limiting component life. Designers have put renewed attention on clearance control, as it is often the most cost effective method to enhance system performance. Advanced concepts and proper material selection continue to play important roles in maintaining interface clearances to enable the system to meet design goals. This work presents an overview of turbomachinery sealing to control clearances. Areas covered include: characteristics of gas and steam turbine sealing applications and environments, benefits of sealing, types of standard static and dynamics seals, advanced seal designs, as well as life and limitations issues.

  15. Rotary shaft seal

    DOEpatents

    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 transucer 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.

  16. Rotary shaft seal

    DOEpatents

    Langebrake, Clair 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.

  17. Transmission seal development

    NASA Technical Reports Server (NTRS)

    Brien, M.

    1977-01-01

    An experimental evaluation was performed on a high-speed (72.9 m/s, 14,349 ft/min) transmission seal of the synergistic type. During testing of the seal, oil leakage occurred at positive bearing cavity pressures. Modifications were made in an attempt to eliminate the leakage but none were completely successful. Leakage appears to be the result of questionable positioning of the sealing elements resulting in inadequate shaft contact by the oil side sealing element. This condition may be related to the nonsymmetrical shape of the elastomeric retainer and to dimensional changes caused by swelling of the elastomeric retainer from exposure to the sealed fluid. Indications of a speed dependent leakage characteristic were also observed.

  18. SSME interstage seal research

    NASA Technical Reports Server (NTRS)

    Childs, D. W.

    1984-01-01

    Test results comprising direct and transverse force coefficients and leakage coefficients are reported for six seal configurations. All seals tested use the same smooth rotor and have the same constant minimum clearance. The following stator configurations were tested: (1) Smooth, (2) knurled pattern, (3) axially-grooved pattern with end seals, (4) diamond-grid roughened, (5) diamond-grid roughened with end seals, and (6) round-hole pattern. Comparison of the seals shows the Knurled-pattern stator to be the stiffest and the round-hole pattern stator to yield the largest net damping and the least leakage. The theory of reference is shown to substantially underestimate the stiffness and effective-added-mass coefficients, but do a reasonable job in predicting the net-damping-force coefficient.

  19. HSCT Anticipated Seal Needs Turbomachinery Seals Combustor Seals

    NASA Technical Reports Server (NTRS)

    Henry, John

    2006-01-01

    The High Speed Civil Transport (HSCT) engine concept is a large mixed flow turbofan similar in construction to current military fighter engines. The mission, however, is quite different. The engine will operate for long periods of time at very high Mach numbers and high altitudes. The engine is required to have very low emissions and noise levels to be acceptable in commercial service. Current thrust levels are in the 55000 lb range. At the current supercruise speed requirement of Mach 2.4, the engine inlet temperature will be at least 380 F. This is the lowest cycle temperature expected anywhere in the propulsion system.Seals will be exposed to operate at this temperature and higher for thousands of hours without failure. Durability, cost, and weight will all be very important in determining the type of seals selected for a successful HSCT engine.

  20. Seals Flow Code Development 1993

    NASA Technical Reports Server (NTRS)

    Liang, Anita D. (Compiler); Hendricks, Robert C. (Compiler)

    1994-01-01

    Seals Workshop of 1993 code releases include SPIRALI for spiral grooved cylindrical and face seal configurations; IFACE for face seals with pockets, steps, tapers, turbulence, and cavitation; GFACE for gas face seals with 'lift pad' configurations; and SCISEAL, a CFD code for research and design of seals of cylindrical configuration. GUI (graphical user interface) and code usage was discussed with hands on usage of the codes, discussions, comparisons, and industry feedback. Other highlights for the Seals Workshop-93 include environmental and customer driven seal requirements; 'what's coming'; and brush seal developments including flow visualization, numerical analysis, bench testing, T-700 engine testing, tribological pairing and ceramic configurations, and cryogenic and hot gas facility brush seal results. Also discussed are seals for hypersonic engines and dynamic results for spiral groove and smooth annular seals.

  1. Reactor cavity seal ring

    SciTech Connect

    Hankinson, M.F.

    1986-04-22

    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.

  2. Sealing device for providing a seal in a turbomachine

    DOEpatents

    Lacy, Benjamin Paul; Kottilingam, Srikanth Chandrudu; Porter, Christopher Donald; Schick, David Edward; Weber, David Wayne

    2016-08-16

    Sealing device for providing seals between adjacent components, and turbomachines utilizing such sealing devices, are provided. A sealing device includes a seal plate insertable between the adjacent components, the seal plate comprising a first face and an opposing second face. The sealing device further includes a plurality of pins extending from one of the first face or the second face, the plurality of pins configured to space the one of the first face or the second face from contact surfaces of the adjacent components.

  3. Multilayer compressive seal for sealing in high temperature devices

    DOEpatents

    Chou, Yeong-Shyung; Stevenson, Jeffry W.

    2007-08-21

    A mica based compressive seal has been developed exhibiting superior thermal cycle stability when compared to other compressive seals known in the art. The seal is composed of compliant glass or metal interlayers and a sealing (gasket) member layer composed of mica that is infiltrated with a glass forming material, which effectively reduces leaks within the seal. The compressive seal shows approximately a 100-fold reduction in leak rates compared with previously developed hybrid seals after from 10 to about 40 thermal cycles under a compressive stress of from 50 psi to 100 psi at temperatures in the range from 600.degree. C. to about 850.degree. C.

  4. Bellow seal and anchor

    DOEpatents

    Mansure, Arthur J.

    2001-01-01

    An annular seal is made of a collapsible bellows. The bellows can function as an anchor or a seal and is easily set into position using relative component movement. The bellows folds can be slanted and their outer sealing edges can have different profiles to meet expected conditions. The bellows is expanded for insertion to reduce its outer dimension and sets by compaction as a result of relative movement. The bellows can be straight or tapered and is settable with a minimal axial force.

  5. Gland With Cantilever Seal

    NASA Technical Reports Server (NTRS)

    Melton, Patrick B.

    1989-01-01

    Single-piece gland forms tight seal on probe or tube containing liquid or gas at high pressure. Gland and probe align as assembled by simple torquing procedure. Disconnected easily and reused at same site. Made from any of wide variety of materials so compatible with application. Cantilever ring at top of gland bites into wall of tube or probe, sealing it. Wall of tube or probe must be thick enough to accommodate deformation without rupturing. Maximum deformation designed in coordination with seating and deformation of boss or conical seal.

  6. SEALING SIMULATED LEAKS

    SciTech Connect

    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.

  7. Engine sealing and lubrication systems

    NASA Technical Reports Server (NTRS)

    Zuk, J.

    1975-01-01

    Engine sealing programs are discussed which are directed toward the two major classes of engine seals: engine shaft seals and primary gas path seals. In addition, some concepts and results from fundamental lubrication research, as it pertains to the lubrication of bearings, are presented.

  8. Sensitivity of the Weddell Sea sector ice streams to sub-shelf melting and surface accumulation

    NASA Astrophysics Data System (ADS)

    Wright, A. P.; Le Brocq, A. M.; Cornford, S. L.; Bingham, R. G.; Corr, H. F. J.; Ferraccioli, F.; Jordan, T. A.; Payne, A. J.; Rippin, D. M.; Ross, N.; Siegert, M. J.

    2014-11-01

    A recent ocean modelling study indicates that possible changes in circulation may bring warm deep-ocean water into direct contact with the grounding lines of the Filchner-Ronne ice streams, suggesting the potential for future ice losses from this sector equivalent to ~0.3 m of sea-level rise. Significant advancements have been made in our knowledge of both the basal topography and ice velocity in the Weddell Sea sector, and the ability to accurately model marine ice sheet dynamics, thus enabling an assessment to be made of the relative sensitivities of the diverse collection of ice streams feeding the Filchner-Ronne Ice Shelf. Here we use the BISICLES ice sheet model, which employs adaptive-mesh refinement to resolve grounding line dynamics, to carry out such an assessment. The impact of realistic perturbations to the surface and sub-shelf mass balance forcing fields from our 2000-year "reference" model run indicate that both the Institute and Möller ice streams are highly sensitive to changes in basal melting either near to their respective grounding lines, or in the region of the ice rises within the Filchner-Ronne Ice Shelf. These same perturbations have little impact, however, on the Rutford, Carlson or Foundation ice streams, while the Evans Ice Stream is found to enter a phase of unstable retreat only after melt at its grounding line has increased by 50% of likely present-day values.

  9. Diversity and distribution of Porifera in the bathyal and abyssal Weddell Sea and adjacent areas

    NASA Astrophysics Data System (ADS)

    Janussen, Dorte; Tendal, Ole Secher

    2007-08-01

    During the ANDEEP I-III expeditions, we obtained a rich and highly diverse sponge collection from the deep Weddell Sea. All the three Poriferan classes, Calcarea, Demospongiae and Hexactinellida, were well represented. Among this material, we have identified a total of 76 species from 47 genera and 30 families. Of these, 17 species (22%) are new to science and 37 (49%) new for the Southern Ocean. Particularly remarkable is the considerable depth of the boundary between bathyal and abyssal sponge faunas. Both Demospongiae and Hexactinellida show a strong shift in their taxonomic composition from a typical shelf assemblage to a more cosmopolitan deep-sea fauna at around 2500 m. Within the Demospongiae, the families Polymastiidae and Cladorhizidae (carnivorous sponges) are particularly abundant and very diverse. The Calcarea are recorded for the first time from the Antarctic deep sea. The type of sampling gear used, especially the epibenthic sledge, was an important factor for the successful collection of deep-sea sponges during the ANDEEP campaigns.

  10. Roughness of Weddell Sea ice and estimates of the air-ice drag coefficient

    NASA Technical Reports Server (NTRS)

    Andreas, Edgar L.; Lange, Manfred A.; Ackley, Stephen F.; Wadhams, Peter

    1993-01-01

    Snow surface, ice surface, and ice underside roughness computed from 47 surface elevation profiles collected during a transect of the Weddell Sea are reported. Roughness spectra for all three surfaces and for both deformed and undeformed ice roll off roughly as k exp -1 when the wavenumber k is between 0.1 and 3 rad/m. The snow surface and underside spectra roll off somewhat faster than k exp -1, and the ice surface spectra roll off somewhat slower than k exp -1. It is argued that the excess spectral intensity at high wavenumbers in the Antarctic ice surface spectra results from the small-scale roughness that the ice sheet had on consolidation. The snow surface spectra are used to compute a roughness scale that parameterizes the air-ice momentum coupling and makes it possible to estimate the neutral stability drag coefficient referenced to a height of 10 m, C sub DN10. Typical C sub DN10 values are 1.1-1.4 x 10 exp -3 over undeformed ice and 1.3-1.8 x 10 exp -3 over deformed ice.

  11. Seasonal resonance of diurnal coastal trapped waves in the southern Weddell Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Semper, Stefanie; Darelius, Elin

    2017-01-01

    The summer enhancement of diurnal tidal currents at the shelf break in the southern Weddell Sea is studied using velocity measurements from 29 moorings during the period 1968 to 2014. Kinetic energy associated with diurnal tidal frequencies is largest at the shelf break and decreases rapidly with distance from it. The diurnal tidal energy increases from austral winter to summer by, on average, 50 %. The austral summer enhancement is observed in all deployments. The observations are compared to results from an idealised numerical solution of the properties of coastal trapped waves (CTWs) for a given bathymetry, stratification and an along-slope current. The frequency at which the dispersion curve for mode 1 CTWs displays a maximum (i.e. where the group velocity is zero and resonance is possible) is found within or near the diurnal frequency band, and it is sensitive to the stratification in the upper part of the water column and to the background current. The maximum of the dispersion curve is shifted towards higher frequencies, above the diurnal band, for weak stratification and a strong background current (i.e. austral winter-like conditions) and towards lower frequencies for strong upper-layer stratification and a weak background current (austral summer). The seasonal evolution of hydrography and currents in the region is inferred from available mooring data and conductivity-temperature-depth profiles. Near-resonance of diurnal tidal CTWs during austral summer can explain the observed seasonality in tidal currents.

  12. Active and Passive Microwave Determination of the Circulation and Characteristics of Weddell and Ross Sea Ice

    NASA Technical Reports Server (NTRS)

    Drinkwater, Mark R.; Liu, Xiang

    2000-01-01

    A combination of satellite microwave data sets are used in conjunction with ECMWF (Medium Range Weather Forecasts) and NCEP (National Center for Environment Prediction) meteorological analysis fields to investigate seasonal variability in the circulation and sea-ice dynamics of the Weddell and Ross Seas. Results of sea-ice tracking using SSM/I (Special Sensor Microwave Imager), Scatterometer and SAR images are combined with in-situ data derived from Argos buoys and GPS drifters to validate observed drift patterns. Seasonal 3-month climatologies of ice motion and drift speed variance illustrate the response of the sea-ice system to seasonal forcing. A melt-detection algorithm is used to track the onset of seasonal melt, and to determine the extent and duration of atmospherically-led surface melting during austral summer. Results show that wind-driven drift regulates the seasonal distribution and characteristics of sea-ice and the intensity of the cyclonic Gyre circulation in these two regions.

  13. Low-frequency currents and continental shelf waves in the southern Weddell Sea

    SciTech Connect

    Middleton, J.H.; Foster, T.D.; Foldvik, A.

    1982-07-01

    The salient features of low-frequency current fluctuations, obtained from an analysis of eight current meter records from the continental shelf and slope of the southern Weddell sea, are compared to baroclinic and barotropic theories. A simple baroclinic theory of internal waves is used successfully to predict high-frequency spectral cutoff values from low-frequency velocity ellipse calculations made from the continental slope mooring data. The success of this theory indicates that the higher spectral energy levels observed over the slope compared to the shelf are probably due to baroclinic motions. A barotropic model of free continental shelf waves proposed by Saint-Guily (1976) is adapted for the local topography and the predictions of the model compared to observations. Coherences and phases between moorings separated by 10 and 160 km in the long-shelf direction provide substantial evidence of the existence of shelf waves as predicted by the theory for periods of 3--60 days and for the lowest three modes. For periods of 3--8 days rotary spectral levels indicate anticlockwise rotating current vectors over the shelf as predicted by theory, but for longer periods current vectors rotate clockwise. It is speculated that fluctuations in along-shelf wind stress drive the shelf waves but that the longer period motions are driven directly by the wind stress.

  14. Tamper indicating seal

    DOEpatents

    Romero, Juan A [Albuquerque, NM; Walker, Charles A [Albuquerque, NM; Blair, Dianna S [Albuquerque, NM; Bodmer, Connie C [Albuquerque, NM

    2012-05-29

    Seals have a flexible wire that can be looped through a hasp-like device. The seals include a body having a recess, a plug insertable into the recess and a snap ring for fastening the plug to the body. The plug and/or body can have access holes for inserting the wire into the recess. "Teeth" on the outer diameter and through-holes through the thickness of the snap ring allow for passing the ends of the flexible wire from the recess through the snap ring. The ends of the wire can be folded back over the snap ring and into engagement with the teeth. Assembly of the seal causes the ends of the wire to be securely fastened between the teeth of the snap ring and the sidewall of the recess. Seals can include a plug and/or body made of a frangible material such as glass, ceramic, glass-ceramic or brittle polymer.

  15. Gas turbine sealing apparatus

    SciTech Connect

    Marra, John Joseph; Wessell, Brian J.; Liang, George

    2013-03-05

    A sealing apparatus in a gas turbine. The sealing apparatus includes a seal housing apparatus coupled to a disc/rotor assembly so as to be rotatable therewith during operation of the gas turbine. The seal housing apparatus comprises a base member, a first leg portion, a second leg portion, and spanning structure. The base member extends generally axially between forward and aft rows of rotatable blades and is positioned adjacent to a row of stationary vanes. The first leg portion extends radially inwardly from the base member and is coupled to the disc/rotor assembly. The second leg portion is axially spaced from the first leg portion, extends radially inwardly from the base member, and is coupled to the disc/rotor assembly. The spanning structure extends between and is rigidly coupled to each of the base member, the first leg portion, and the second leg portion.

  16. Flexible cloth seal assembly

    DOEpatents

    Bagepalli, B.S.; Taura, J.C.; Aksit, M.F.; Demiroglu, M.; Predmore, D.R.

    1999-06-29

    A seal assembly is described having a flexible cloth seal which includes a shim assemblage surrounded by a cloth assemblage. A first tubular end portion, such as a gas turbine combustor, includes a longitudinal axis and has smooth and spaced-apart first and second surface portions defining a notch there between which is wider at its top than at its bottom and which extends outward from the axis. The second surface portion is outside curved, and a first edge of the cloth seal is positioned in the bottom of the notch. A second tubular end portion, such as a first stage nozzle, is located near, spaced apart from, and coaxially aligned with, the first tubular end portion. The second tubular end portion has a smooth third surface portion which surrounds at least a portion of the first tubular end portion and which is contacted by the cloth seal. 7 figs.

  17. Rotatable seal assembly

    DOEpatents

    Logan, Clinton M.; Garibaldi, Jack L.

    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 O-ring. 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.

  18. Flexible cloth seal assembly

    DOEpatents

    Bagepalli, Bharat Sampathkumar; Taura, Joseph Charles; Aksit, Mahmut Faruk; Demiroglu, Mehmet; Predmore, Daniel Ross

    1999-01-01

    A seal assembly having a flexible cloth seal which includes a shim assemblage surrounded by a cloth assemblage. A first tubular end portion, such as a gas turbine combustor, includes a longitudinal axis and has smooth and spaced-apart first and second surface portions defining a notch therebetween which is wider at its top than at its bottom and which extends outward from the axis. The second surface portion is outside curved, and a first edge of the cloth seal is positioned in the bottom of the notch. A second tubular end portion, such as a first stage nozzle, is located near, spaced apart from, and coaxially aligned with, the first tubular end portion. The second tubular end portion has a smooth third surface portion which surrounds at least a portion of the first tubular end portion and which is contacted by the cloth seal.

  19. Turbine seal assembly

    SciTech Connect

    Little, David A.

    2013-04-16

    A seal assembly that limits gas leakage from a hot gas path to one or more disc cavities in a turbine engine. The seal assembly includes a seal apparatus that limits gas leakage from the hot gas path to a respective one of the disc cavities. The seal apparatus comprises a plurality of blade members rotatable with a blade structure. The blade members are associated with the blade structure and extend toward adjacent stationary components. Each blade member includes a leading edge and a trailing edge, the leading edge of each blade member being located circumferentially in front of the blade member's corresponding trailing edge in a direction of rotation of the turbine rotor. The blade members are arranged such that a space having a component in a circumferential direction is defined between adjacent circumferentially spaced blade members.

  20. Ingestion resistant seal assembly

    SciTech Connect

    Little, David A

    2011-12-13

    A seal assembly limits gas leakage from a hot gas path to one or more disc cavities in a gas turbine engine. The seal assembly includes a seal apparatus associated with a blade structure including a row of airfoils. The seal apparatus includes an annular inner shroud associated with adjacent stationary components, a wing member, and a first wing flange. The wing member extends axially from the blade structure toward the annular inner shroud. The first wing flange extends radially outwardly from the wing member toward the annular inner shroud. A plurality of regions including one or more recirculation zones are defined between the blade structure and the annular inner shroud that recirculate working gas therein back toward the hot gas path.

  1. Conduit sealing system

    SciTech Connect

    Weinberg, R.A.

    1984-02-28

    The invention relates to an annular seal system designed for high pressure applications in subterranean wells. The annular seal system comprises a vertical stack of subassemblies. Each subassembly incorporates an annular sealing element formed from an elastomeric material, such as a perfluoroelastomer, which is provided with a truncated pear-shaped cross-sectional configuration having reversely curved axial side surfaces. The sealing element is abutted on each axial side by a uniform thickness annular bearing element formed from a thermoplastic such as a polyphenylene sulfide resin having good bearing properties. Each of the thermoplastic bearing elements is in turn abutted by an annular metallic restraining element having correspondingly shaped reversely curved axial side surfaces and defining an inverted truncated pear-shaped cross-sectional configuration.

  2. Current developments in brush seals

    NASA Technical Reports Server (NTRS)

    Loewenthal, Bob

    1994-01-01

    The objective of the brush seal development program is to develop a comprehensive design methodology for brush seals using application requirements from engine manufacturers and experimental characterization of seal design and tribological pairs. The goals are to substantially lower leakage compared to labyrinth seals, seal life consistent with man-rated mission requirements, to investigate single and multiple staged brush seals, temperature up to 1200 F and surface speed up to 900 fps, and pressure drop across the seal of 50 psid. Test results are presented in viewgraph format.

  3. Ultra high vacuum seal arrangement

    DOEpatents

    Flaherty, Robert

    1981-01-01

    Arrangement for demountably sealing two concentric metallic tubes in an ultra high vacuum system which facilitates remote actuation. A tubular seal includes integral spaced lips which circumferentially engage the metallic tubes. The lips plastically deform the metallic tubes by mechanical forces resulting from a martensite to austenite transformation of the tubular seal upon application of a predetermined temperature. The sealing force is released upon application of another temperature which causes a transformation from the stronger austenite to the weaker martensite. Use of a dual acting sealing ring and driving ring circumferentially contacting the sealing ring is particularly applicable to sealing larger diameter concentric metallic members.

  4. Seal system with integral detector

    DOEpatents

    Fiarman, S.

    1982-08-12

    A seal system is disclosed for materials where security is of the essence, such as nuclear materials. The seal is tamper-indicating, indicates changes in environmental conditions that evidence attempts to bypass the seal, is unique and cost effective. The seal system is comprised of a seal where an optical signal is transmitted through a loop, with a detector to read said signal, and one or more additional detectors designed to detect environmental changes, these detectors being operatively associated with the seal so that detection of a break in the optical signal or detection of environmental changes will cause an observable change in the seal.

  5. Self-acting shaft seals

    NASA Technical Reports Server (NTRS)

    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.

  6. Core disruptive accident margin seal

    DOEpatents

    Golden, Martin P.

    1979-01-01

    Apparatus for sealing the annulus defined within a substantially cylindrical rotatable riser assembly and plug combination of a nuclear reactor closure head. 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.

  7. Radial pressure flange seal

    DOEpatents

    Batzer, Thomas H.; Call, Wayne R.

    1989-01-01

    This invention provides an all metal seal for vacuum or pressure vessels or systems. This invention does not use gaskets. The invention uses a flange which fits into a matching groove. Fluid pressure is applied in a chamber in the flange causing at least one of the flange walls to radially press against a side of the groove creating the seal between the flange wall and the groove side.

  8. Radial pressure flange seal

    DOEpatents

    Batzer, T.H.; Call, W.R.

    1989-01-24

    This invention provides an all metal seal for vacuum or pressure vessels or systems. This invention does not use gaskets. The invention uses a flange which fits into a matching groove. Fluid pressure is applied in a chamber in the flange causing at least one of the flange walls to radially press against a side of the groove creating the seal between the flange wall and the groove side. 5 figs.

  9. Titanium hermetic seals

    DOEpatents

    Brow, Richard K.; Watkins, Randall D.

    1995-01-01

    Titanium is prenitrided by being heated in a nitrogen environment under conditions which give rise to the formation of a titanium-nitride surface layer on the titanium. Titanium thus prenitrided may be used in electrical components which are hermetically sealed using silicate glasses and standard glass sealing techniques. According to the method of the invention, alkali volatilization and formation of deleterious interfacial silicide are inhibited.

  10. Titanium hermetic seals

    DOEpatents

    Brow, Richard K.; Watkins, Randall D.

    1995-07-04

    Titanium is prenitrided by being heated in a nitrogen environment under conditions which give rise to the formation of a titanium-nitride surface layer on the titanium. Titanium thus prenitrided may be used in electrical components which are hermetically sealed using silicate glasses and standard glass sealing techniques. According to the method of the invention, alkali volatilization and formation of deleterious interfacial silicide are inhibited.

  11. Entrapment of adult fingers between window glass and seal entry of a motor vehicle side door: an experimental study for investigation of the force at the subjective pain threshold.

    PubMed

    Hohendorff, B; Weidermann, C; Pollinger, P; Burkhart, K J; Konerding, M A; Prommersberger, K J; Rommens, P M

    2011-07-28

    In modern motor vehicles with automatic power windows, a potential hazard exists for jam events of fingers between the window glass and seal entry. This study determined entrapment forces acting on adult fingers at the subjective maximum pain threshold during entrapment in such windows. The length and the girth of the proximal and distal interphalangeal joints of the triphalangeal fingers of the right hands of 109 participants (60 men, 49 women) were measured; the diameter was calculated from girth, which was assumed to be circular. The automatic power window system of a motor vehicle side door was changed to a mechanical system. During entrapment the force distributed across the four proximal interphalangeal joints (PIPs), and separately on the proximal interphalangeal (iPIP) and then the distal interphalangeal (iDIP) joints of the index finger was measured using a customized force sensor. The maximum bearable entrapment force was 97.2 ± 51.8 N for the PIPs, 43.4 ± 19.9 N for the iPIP, and 36.9 ± 17.8 N for the iDIP. The positive correlation between finger diameter and maximum entrapment force was significant. Particularly with regard to the risk to children's fingers, the 100 N statutory boundary value for closing force of electronic power windows should be reduced.

  12. Applauding the performing seal

    SciTech Connect

    Not Available

    1992-03-01

    Whether the culprit is a pump, valve, compressor, or flanged pipe connection, the end result is the same: process-fluid leakage damages the environment and is costly to operators, in terms of lost product, lost production due to downtime, and the replacement of damaged process equipment. Hard-to-handle fluids, such as abrasive slurries of coal and flyash, can damage the seals that contain them, allowing potentially harmful fluids to escape. Even more insidious is the often-invisible escape of volatile organic compounds (VOCs) from equipment that handles liquid petroleum, petroleum by-products and chemicals. This paper reports that seal manufacturers are using their ingenuity to minimize the escape of liquid and gaseous emissions. One approach uses the power of magnetic attraction to create a seal along a rotating pump shaft by positioning magnetic fluids there. Ferrofluidics Corp. starts by creating a magnetic fluid - essentially a colloidal suspension of ultrafine magnetic salts dispersed in a carrier fluid - which is then used as a liquid O-ring seal in conjunction with a mechanical seal. The seal apparatus consists of a doughnut-shaped sandwich (centered around the pump shaft), with a permanent magnet as the middle layer, and a washer of magnetically permeable material on either side.

  13. Nuclear instrumentation cable end seal

    DOEpatents

    Cannon, Collins P.; Brown, Donald 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. 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.

  14. Pressure Actuated Leaf Seals for Improved Turbine Shaft Sealing

    NASA Technical Reports Server (NTRS)

    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.

  15. Shaft seal assembly and method

    NASA Technical Reports Server (NTRS)

    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.

  16. Impact of coastal polynyas on sea ice production and water mass modification in the southwestern Weddell Sea

    NASA Astrophysics Data System (ADS)

    Haid, V.; Timmermann, R.; Ebner, L.; Heinemann, G.

    2012-04-01

    The thermohaline circulation of the world ocean is partly driven by deep water formation at high-latitudes. In the Southern Ocean, deep and bottom water formation in the marginal seas is induced by high freezing rates as generally found at coastal polynyas. Atmospheric cooling and brine-release enable the production of very cold and saline water masses. In the southwestern Weddell Sea, wide shelves allow for a strong salinification of the whole water column and the formation of High Salinity Shelf Water (HSSW). The impact of coastal polynyas on ice production and water mass formation in the southwestern Weddell Sea was studied employing the Finite Element Sea ice-Ocean Model (FESOM) of the Alfred Wegener Institute, Bremerhaven. FESOM is a coupled system of a primitive-equation, hydrostatic ocean model and a dynamic-thermodynamic sea ice model. Simulations were conducted on a global unstructured mesh with a strong focus on the southwestern Weddell Sea coastline (up to 3 km resolution). In vertical direction, the grid features 37 z-coordinate depth levels of which 6 are within the uppermost 100 m. The model runs were initialised in 1980 and forced with NCEP reanalysis data (daily resolution). The year 2008 was also simulated with higher-resolution GME and regional COSMO forcing data. For data evaluation and analysis the period 1990-2009 is used. A comparison of AMSR sea ice concentration and model results shows good accordance in spatial and temporal polynya extent. Also, calculated vertical temperature and salinity profiles agree well with CTD measurements. Our simulations feature a 20-year winter mean area of coastal polynyas of 6.7 · 103 km2 (0.4% of the continental shelf area) in the southwestern Weddell Sea which is in good agreement with observations. Winter sea ice production within the coastal polynyas exceeds the ice production of the surrounding ice-covered area by a factor of 7 in the 20-year mean, so that the polynya contribution to total sea ice

  17. Interannual controls on Weddell Sea surface water fCO 2 during the autumn-winter transition phase

    NASA Astrophysics Data System (ADS)

    Bellerby, Richard G. J.; Hoppema, Mario; Fahrbach, Eberhard; de Baar, Hein J. W.; Stoll, Michel H. C.

    2004-06-01

    The fugacity of carbon dioxide ( fCO 2) of the surface waters of the Weddell Sea along the prime meridian has been described for the austral autumn in 1996 and 1998. For individual years, fCO 2 has a strong linear relationship with sea surface temperature, although the relationships cannot be reconciled to provide an interannually consistent algorithm for remotely sensed assessment of fCO 2. However, from the assumption that Weddell Sea surface water has a single end member (upwelled Warm Deep Water) we have determined the relative contributions of heating, ice-melt, and biological activity on fCO 2. A breakdown of the controls shows that the measured annual fCO 2 distributions can be recreated for both transects by adjusting solely for thermodynamic forcing, and model adjustments for salinity are small except in regions of significant upwelling during 1998. The incorporation of nitrate utilisation into the model results in a general and significant underestimation of fCO 2. This runs contrary to the earlier findings of Sabine and Key (Mar. Chem. 60 (1998) 95) in the Southern Ocean although it is consistent with models in the area (Louanchi et al., Deep-Sea Res. I 48 (2001) 1581). A major caveat to these findings is the significant departure of the thermodynamic model and a tightening of the nitrate-adjusted model in 1998 in areas with deeper mixing in the southern Weddell Sea. We propose that there are two reasons for the discrepancies in our model: the source waters are not as homogenous as the model assumes; and there are geographical and seasonal variations of CO 2 exchange with the atmosphere and the input of inorganic carbon and nitrate from below the mixed layer resulting in imbalances in the mixed layer concentration ratios.

  18. Oil Saving Seal

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Driven under difficult field conditions, the Army Jeep shown went more than 22,000 miles without an oil change in a test conducted by the U.S. Army Mobility Equipment Research and Development Command. Key to this exceptionally long oil life was a set of piston ring seals made of a new synthetic rubber formula called RC-34; the seal pictured, photographed after its arduous Army trial, shows no signs of deterioration. The seal and the RC-34 material, which may soon be available for use in the family auto, were developed by Ramsey Corporation, St. Louis, Missouri, a division of TRW Automotive Worldwide. The oil in an automobile engine must be I replaced every few thousand miles not because it wears out but because it becomes contaminated. The contamination sources are gasoline and combustion gases which blow by the piston rings to mix with the oil, reducing the oil's ability to lubricate properly. Seeking to prolong oil life by eliminating "blowby," Ramsey Corporation looked for a better way to seal piston rings and used NASA technology as a departure point. The parent company TRW, under contract to NASA's Jet Propulsion Laboratory, had developed seals and bladders from a type of material called elastomers which where designed to withstand the environmental extremes of interplanetary flight. That effort formed a knowledge base for research which culminated in Ramsey's RC-34 elastomer.

  19. Persistent organic pollutants in ringed seals from the Russian Arctic.

    PubMed

    Savinov, Vladimir; Muir, Derek C G; Svetochev, Vladislav; Svetocheva, Olga; Belikov, Stanislav; Boltunov, Andrey; Alekseeva, Ludmila; Reiersen, Lars-Otto; Savinova, Tatiana

    2011-06-15

    Organochlorine compounds total DDT (ΣDDT), total HCH isomers (ΣHCH), toxaphenes (sum of Parlar 26, 50, 62), mirex, endrin, methoxychlor, total chlorinated benzenes (ΣCBz), total chlordane compounds (ΣCHL), polychlorinated biphenyls (total of 56 congeners; ΣPCBs), polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), and polybrominated diphenyl ethers (sum of 7 tri- to hepta congeners; ΣPBDEs) were analysed in the blubber of adult ringed seals from the four areas of the Russian Arctic (White Sea, Barents Sea, Kara Sea and Chukchi Sea) collected in 2001-2005. Ringed seals from the south-western part of the Kara Sea (Dikson Island - Yenisei estuary) were the most contaminated with ΣDDTs, ΣPCBs, ΣCHL, and mirex as compared with those found in the other three areas of Russian Arctic, while the highest mean concentrations of ΣHCHs and PCDD/Fs were found in the blubber of ringed seals from the Chukchi Sea and the White Sea, respectively. Among all organochlorine compounds measured in ringed seals from the European part of the Russian Arctic, concentrations of ΣDDT and ΣPCBs only were higher as compared with the other Arctic regions. Levels of all other organochlorine compounds were similar or lower than in seals from Svalbard, Alaska, the Canadian Arctic and Greenland. ΣPBDEs were found in all ringed seal samples analysed. There were no significant differences between ΣPBDE concentrations found in the blubber of ringed seals from the three studied areas of the European part of the Russian Arctic, while PBDE contamination level in ringed seals from the Chukchi Sea was 30-50 times lower. ΣPBDE levels in the blubber of seals from the European part of the Russian Arctic are slightly higher than in ringed seals from the Canadian Arctic, Alaska, and western Greenland but lower compared to ringed seals from Svalbard and eastern Greenland.

  20. An outbreak of leptospirosis in seals (Phoca vitulina) in captivity.

    PubMed

    Kik, M J L; Goris, M G; Bos, J H; Hartskeerl, R A; Dorrestein, G M

    2006-03-01

    An outbreak of leptospirosis in seals (Phoca vitulina) in captivity is described. In a zoo in The Netherlands 5 adult seals died within 12 days. At necropsy all animals showed signs of acute septicaemia, consistent with acute leptospirosis. Serological examination of one animal was positive for antibodies against Leptospira interrogans serovar Icterohaemorrhagiae and the serologically closely related serovar Copenhageni. Polymerase chain reaction was positive in one other animal. 8 nutria (Myocastor coypus) were examined, serologically, through bacteriological culture and PCR. 81,8% (9/11) were serologically positive for Leptospira. The seals and nutria were housed in the same water system.

  1. Design guide for helicopter transmission seals

    NASA Technical Reports Server (NTRS)

    Hayden, T. S.; Keller, C. H., Jr.

    1974-01-01

    A detailed approach for the selection and design of seals for helicopter transmissions is presented. There are two major types of seals presently being used and they are lip type seals and mechanical type seals. Lip type seals can be divided in conventional lip seals and hydrodynamic lip seals. Conventional lip seals can be used for slow-speed, low-pressure, low-temperature sealing. Hydrodynamic lip seals although they are as pressure and temperature limited as conventional lip seals, can operate at a higher speed. Mechanical types seals are comprised of face seals and circumferential seals. Face seals are capable of high speed, high pressure, and high temperature. Circumferential seals can be used in high-speed and high-temperature applications, but will leak excessively at moderate pressures. The performance goals of transmission seals are a life that is at least equal to the scheduled overhaul interval of the gearbox component and a leakage rate of near zero.

  2. Pathological findings of a fatal leopard seal attack.

    PubMed

    Rutty, Guy N

    2007-03-01

    A unique case of a fatal leopard seal attack against an adult human female is presented. The death occurred in Rothera, Antarctica when the female was snorkeling while undertaking scientific research. The principle injuries occurred, during life, to the facial areas prior to the act of drowning. The method of attack of leopard seals against their natural prey is discussed and related to the findings on the deceased.

  3. Midwater food web in the vicinity of a marginal ice zone in the western Weddell Sea

    NASA Astrophysics Data System (ADS)

    Hopkins, Thomas L.; Torres, Joseph J.

    1989-04-01

    The structure of the food web in the vicinity of a marginal ice zone was investigated in the western Weddell Sea during austral autumn 1986. The diets of 40 species of zooplankton and micronekton occurring in the epipelagic zone were examined and compared using non-hierarchical clustering procedures. Over half the species were in three clusters of predominantly small-particle (phytoplankton; protozoans) grazers. These included biomass dominants Calanoides acutus, Calanus propinquus, Metridia gerlachei and Salpa thompsoni. Six clusters contained omnivores that had diets consisting of small particles as well as a substantial fraction of metazoan food. Among these was Euphausia superba. Seven groups were carnivorous, including species of copepods (1), chaetognaths (3), and fishes (5). Copepods were the most frequent food of carnivores; however krill also were important in the diets of three fish species. Among small-particle grazers, phytoplankton occurred more frequently in guts of individuals from open water; carnivory was more in evidence in samples collected under the pack ice. Regional comparisons of material taken on this and several previous cruises indicate that, in most of the dominant species, diets remain relatively consistent with respect to major food categories. Seasonal impact on feeding dynamics appears to be great: the guts of grazing species were generally much more full (visual evidence) during summer bloom conditions than during the autumn. The following trophic sequence is suggested for grazing zooplankton species in ice-covered regions of the Antarctic: (1) Active small-particle grazing during the summer bloom period; (2) reduced ingestion rates in autumn as primary production declines and the system becomes more oligotrophic, with some species augmenting grazing with carnivory; (3) descent of zooplankton biomass species into the mesopelagic zone in late autumn-early winter with feeding largely terminated. The sequence applies to the dominant

  4. Post-glacial thinning history of the Foundation Ice Stream, Weddell Sea embayment, Antarctica

    NASA Astrophysics Data System (ADS)

    Bentley, M.; Hein, A. S.; Sugden, D. E.; Whitehouse, P.; Vieli, A.; Hindmarsh, R. C.

    2012-12-01

    The Antarctic ice sheet is the largest on earth and any instability is likely to dominate global sea level change. We therefore require models of the ice sheet to make more reliable and robust predictions of future change. One problem in meeting this challenge is the lack of past data on deglaciation with which to initialize and calibrate the models. This problem has been particularly acute in the Weddell Sea embayment and in particular its eastern part where the Foundation - Thiel Trough has been a principal drainage route for the West Antarctic Ice Sheet (WAIS), and its southern extension may be a potential location for future instability. Two significantly different models of glacial history have been proposed for the trough. The first, based largely on marine geology suggests that grounded ice extended to the continental shelf at the Last Glacial Maximum (LGM), filling the Foundation-Thiel trough. The second, based largely on terrestrial glacial geology suggests a much more restricted advance of ice in the trough with relatively minor or even zero thickening of the ice sheet onshore. Here we present new glacial geologic data from the margins of the Foundation Ice Stream, which currently occupies the southern extension of the trough. We sampled erratic clasts from several nunataks along > 100km transect of the ice stream, and will present the 10Be ages on these clasts. The data show several hundred metres of thinning occurred along the lower Foundation Ice Stream and its tributary the Academy Glacier in the Holocene. We discuss the implications for the competing models of LGM and post-LGM glacial history.

  5. Linkage between Grounding Line Dynamics and Geological Observations in the Weddell Sea Sector of Antarctica

    NASA Astrophysics Data System (ADS)

    Huybers, K. M.; Roe, G.; Conway, H.; Balco, G.; Todd, C. E.

    2012-12-01

    Surface-exposure dating is a potentially a powerful technique to constrain Antarctic ice-sheet thinning from the Last Glacial Maximum to its present state. Erratics recently collected near the grounding line of the Foundation Ice Stream in Antarctica's Weddell Sea sector detail thickness maxima and exposure rates along local nunatak elevation transects. These points in space and time constrain the local thickness and rate of thinning—however, what can they tell us about the history of the elevation profile of the interior ice stream? The elevation profile of the interior ice is strongly controlled by the position of the grounding line, which in turn depends on sea level, accumulation, and the ice stream/shelf's physical characteristics. We use to an idealized flowline model to assess the relative importance of factors used to model ice stream thickness profiles. We divide these factors into two general categories: model physics, and environmental factors. Model physics includes choices about the ice rheology, the sliding law, and the calculated flux at the grounding line, where the ice transitions from grounded stream to floating shelf. Environmental factors include climate, basal topography, sliding parameterization, sea level, ice softness, and lateral shelf stresses. In our simplified model, we ignore the potentially important effects of isostatic rebound and the gravitational pull of the ice on ocean water. Preliminary findings indicate that the position of the grounding line controls the elevation at the exposure sites; and that sub-glacial and sub-marine basal topography, together with the assumed form of the grounding-line flux, dominates the grounding-line sensitivity to change. This suggests that the surface elevation predominantly reflects regional-scale ice sheet behavior rather than the climate local to the ice-stream catchment.

  6. Seal system with integral detector

    DOEpatents

    Fiarman, Sidney

    1985-01-01

    There is disclosed a seal system for materials where security is of the essence, such as nuclear materials, which is tamper-indicating, which indicates changes in environmental conditions that evidence attempts to by-pass the seal, which is unique and cost effective, said seal system comprised of a seal where an optical signal is transmitted through a loop, with a detector to read said signal, and one or more additional detectors designed to detect environmental changes, these detectors being operatively associated with the seal so that detection of a break in the optical signal or detection of environmental changes will cause an observable change in the seal.

  7. Dye filled security seal

    DOEpatents

    Wilson, Dennis C. W.

    1982-04-27

    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.

  8. REACTOR COOLANT TUBE SEAL

    DOEpatents

    Morris, W.J.

    1958-12-01

    A plle-flattenlng control element and a fluid seal therefore to permit movement of the element into a liquld contnining region of a neutronlc reactor are described. The device consists of flattened, thin-walled aluminum tubing contalnlng a uniform mixture of thermal neutron absorbing material, and a number of soft rubber closures for the process tubes, having silts capable of passing the flattened elements therethrough, but effectively sealing the process tubes against fluld leaknge by compression of the rubber. The flattened tubing is sufficiently flexible to enable it to conform to the configuratlon of the annular spacing surrounding the fuel elements ln the process tubes.

  9. Method of sealing

    DOEpatents

    Groh, Edward F.; Cassidy, Dale A.

    1978-01-01

    A thermocouple lead or other small diameter wire, cable or tube is passed through a thin material such as sheet metal and sealed thereinto by drawing complementary longitudinally angled, laterally rounded grooves terminating at their base ends in a common plane in both sides of the thin material with shearing occuring at the deep end faces thereof to form a rounded opening in the thin material substantially perpendicular to the plane of the thin material, passing a thermocouple lead or similar object through the opening so formed and sealing the opening with a sealant which simultaneously bonds the lead to the thin material.

  10. Sealing coupling. [LMFBR

    DOEpatents

    Pardini, J.A.; Brubaker, R.C.; Rusnak, J.J.

    1982-09-20

    Disclosed is a remotely operable releasable sealing coupling which provides fluid-tight joinder of upper and a lower conduit sections. Each conduit section has a concave conical sealing surface adjacent its end portion. A tubular sleeve having convex spherical ends is inserted between the conduit ends to form line contact with the concave conical end portions. An inwardly projecting lip located at one end of the sleeve cooperates with a retaining collar formed on the upper pipe end to provide swivel capture for the sleeve. The upper conduit section also includes a tapered lower end portion which engages the inside surface of the sleeve to limit misalignment of the connected conduit sections.

  11. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring

    PubMed Central

    Han, Chuanjun

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal. PMID:27019582

  12. Tuberculosis in wild seals and characterisation of the seal bacillus.

    PubMed

    Cousins, D V; Williams, S N; Reuter, R; Forshaw, D; Chadwick, B; Coughran, D; Collins, P; Gales, N

    1993-03-01

    Tuberculosis was diagnosed in 3 otariid seals found dead on beaches at 3 locations on the south coast of Western Australian between May 1990 and March 1991. This confirms that tuberculosis is present in the 2 native seals (Neophoca cinerea and Arctocephalus forsteri) in Western Australian waters. Mycobacterium sp isolated from the lungs of 2 of the seals were studied to determine the similarity of the strains to each other, to the strains isolated during 1986 from Australian sea lions and New Zealand fur seals kept in captivity at a marine park near Perth, Western Australia, and to a strain isolated in 1988 from a seal trainer who worked with the infected captive seals for 3 years. After restriction endonuclease analysis (REA) with the endonucleases Bst EII, Bcl I and Pvu II, one of the wild seal strains appeared to have identical DNA fragment patterns to the strains from the captive seals and the seal trainer. The other wild seal isolate had identical REA profiles using Bst EII and Bcl I, but a minor difference was detected using Pvu II. Differences in these isolates were more clearly seen in restriction fragment length polymorphisms after hybridisation with two DNA probes. The secretory protein MPB70, present in M bovis, was not detected in wild seal isolates using sodium dodecyl sulphate polyacrylamide gel electrophoresis and Western blotting techniques. Analysis of protein and DNA fragment profiles indicated that seal tuberculosis isolates form a unique cluster within the M tuberculosis complex.

  13. Static seal for turbine engine

    DOEpatents

    Salazar, Santiago; Gisch, Andrew

    2014-04-01

    A seal structure for a gas turbine engine, the seal structure including first and second components located adjacent to each other and forming a barrier between high and low pressure zones. A seal cavity is defined in the first and second components, the seal cavity extending to either side of an elongated gap extending generally in a first direction between the first and second components. A seal member is positioned within the seal cavity and spans across the elongated gap. The seal member includes first and second side edges extending into each of the components in a second direction transverse to the first direction, and opposing longitudinal edges extending between the side edges generally parallel to the first direction. The side edges include a groove formed therein for effecting a reduction of gas flow around the seal member at the side edges.

  14. Seal For Precooling A Turbopump

    NASA Technical Reports Server (NTRS)

    Owen, Samuel S.; Mulready, R.C.

    1988-01-01

    Diaphragm reduces misalignment. Rotary seal retains precooling fluid in pump section of cryogenic turbopump, preventing fluid from entering turbine section. Precooling fluid held in pump section of turbopump by knife-edge labyrinth seal on diaphragm.

  15. Sealing micropores in thin castings

    NASA Technical Reports Server (NTRS)

    Mersereau, G. A.; Nitzschke, G. O.; Ochs, H. L.; Sutch, F. S.

    1981-01-01

    Microscopic pores in thin-walled aluminum castings are sealed by impregnation pretreatment. Technique was developed for investment castings used in hermetically sealed chassic for electronic circuitry. Excessively high leakage rates were previously measured in some chassis.

  16. Coating for hot sliding seals

    NASA Technical Reports Server (NTRS)

    Stock, J.

    1979-01-01

    Heat resistant paint is effective surface coating for sliding seals that must operate at elevated temperatures. Economical paint is easy to apply, offers minimal friction, and improves reliability of seals.

  17. Feather seal slot for vanes

    SciTech Connect

    Del Mastro, B. P.; Eckart, F.

    1985-10-22

    The slots for accommodating feather seals in the turbine vanes of a gas turbine engine has the end thereof sealed off by use of weld wire inserted into the slot and simultaneously welded and cut to the required length.

  18. Self-stabilizing radial face seal

    NASA Technical Reports Server (NTRS)

    Etsion, I. (Inventor)

    1981-01-01

    A self-stabilizing radial face seal comprises an axial member and a primary seal ring juxtapositioned to a seal seat. At least one primary seal ring and seal seat unit is affixed to the axial member so as to rotate with it. The primary seal ring has a front face which opposes a face of the seal seat. The seal has both high-pressure and low-pressure regions of fluid, and seal seat is provided with a porous ring-like circumferential structure in the face of the seal seat opposite the front face of the primary seal ring.

  19. Mid-Holocene pulse of thinning in the Weddell Sea sector of the West Antarctic ice sheet.

    PubMed

    Hein, Andrew S; Marrero, Shasta M; Woodward, John; Dunning, Stuart A; Winter, Kate; Westoby, Matthew J; Freeman, Stewart P H T; Shanks, Richard P; Sugden, David E

    2016-08-22

    Establishing the trajectory of thinning of the West Antarctic ice sheet (WAIS) since the last glacial maximum (LGM) is important for addressing questions concerning ice sheet (in)stability and changes in global sea level. Here we present detailed geomorphological and cosmogenic nuclide data from the southern Ellsworth Mountains in the heart of the Weddell Sea embayment that suggest the ice sheet, nourished by increased snowfall until the early Holocene, was close to its LGM thickness at 10 ka. A pulse of rapid thinning caused the ice elevation to fall ∼400 m to the present level at 6.5-3.5 ka, and could have contributed 1.4-2 m to global sea-level rise. These results imply that the Weddell Sea sector of the WAIS contributed little to late-glacial pulses in sea-level rise but was involved in mid-Holocene rises. The stepped decline is argued to reflect marine downdraw triggered by grounding line retreat into Hercules Inlet.

  20. Mid-Holocene pulse of thinning in the Weddell Sea sector of the West Antarctic ice sheet

    PubMed Central

    Hein, Andrew S.; Marrero, Shasta M.; Woodward, John; Dunning, Stuart A.; Winter, Kate; Westoby, Matthew J.; Freeman, Stewart P. H. T.; Shanks, Richard P.; Sugden, David E.

    2016-01-01

    Establishing the trajectory of thinning of the West Antarctic ice sheet (WAIS) since the last glacial maximum (LGM) is important for addressing questions concerning ice sheet (in)stability and changes in global sea level. Here we present detailed geomorphological and cosmogenic nuclide data from the southern Ellsworth Mountains in the heart of the Weddell Sea embayment that suggest the ice sheet, nourished by increased snowfall until the early Holocene, was close to its LGM thickness at 10 ka. A pulse of rapid thinning caused the ice elevation to fall ∼400 m to the present level at 6.5–3.5 ka, and could have contributed 1.4–2 m to global sea-level rise. These results imply that the Weddell Sea sector of the WAIS contributed little to late-glacial pulses in sea-level rise but was involved in mid-Holocene rises. The stepped decline is argued to reflect marine downdraw triggered by grounding line retreat into Hercules Inlet. PMID:27545202

  1. Mid-Holocene pulse of thinning in the Weddell Sea sector of the West Antarctic ice sheet

    NASA Astrophysics Data System (ADS)

    Hein, Andrew S.; Marrero, Shasta M.; Woodward, John; Dunning, Stuart A.; Winter, Kate; Westoby, Matthew J.; Freeman, Stewart P. H. T.; Shanks, Richard P.; Sugden, David E.

    2016-08-01

    Establishing the trajectory of thinning of the West Antarctic ice sheet (WAIS) since the last glacial maximum (LGM) is important for addressing questions concerning ice sheet (in)stability and changes in global sea level. Here we present detailed geomorphological and cosmogenic nuclide data from the southern Ellsworth Mountains in the heart of the Weddell Sea embayment that suggest the ice sheet, nourished by increased snowfall until the early Holocene, was close to its LGM thickness at 10 ka. A pulse of rapid thinning caused the ice elevation to fall ~400 m to the present level at 6.5-3.5 ka, and could have contributed 1.4-2 m to global sea-level rise. These results imply that the Weddell Sea sector of the WAIS contributed little to late-glacial pulses in sea-level rise but was involved in mid-Holocene rises. The stepped decline is argued to reflect marine downdraw triggered by grounding line retreat into Hercules Inlet.

  2. Observing the advection of sea ice in the Weddell Sea using buoy and satellite passive microwave data

    NASA Technical Reports Server (NTRS)

    Massom, Robert A.

    1992-01-01

    Data from four buoys tracked by Nimbus 6 and concurrent ice concentrations retrieved from Nimbus 7 scanning multichannel microwave radiometer data are used to investigate the progress and behavior of an area of sea ice as it drifts from the southwestern Weddell Sea. The overall drift characteristics and their relationship to ice edge displacement are examined within the framework of four zones. Three phases are identified in the large-scale behavior of the Weddell Sea ice cover, namely, a rapid equatorward and eastward advance, a quasi-equilibrium phase, and a period of rapid recession. Outbreaks of cold continental air alternate with incursions of relatively warm air from the north; warm conditions are recorded as far as 1200 km in from the ice edge in winter. Closed loops in the buoy trajectories, which are clockwise to the south of 63 deg S, reverse to become anticlockwise to the north. A coherence is observed in the response of the buoys to the passage of storms, even though the buoys separated by a distance of over 100 km.

  3. GOLD PRESSURE VESSEL SEAL

    DOEpatents

    Smith, A.E.

    1963-11-26

    An improved seal between the piston and die member of a piston-cylinder type pressure vessel is presented. A layer of gold, of sufficient thickness to provide an interference fit between the piston and die member, is plated on the contacting surface of at least one of the members. (AEC)

  4. Piston rod seal

    DOEpatents

    Lindskoug, Stefan

    1984-01-01

    In a piston rod seal of the type comprising a gland through which the piston rod is passed the piston is provided with a sleeve surrounding the piston rod and extending axially so as to axially partly overlap the gland when the piston is in its bottom dead center position.

  5. "The Seventh Seal."

    ERIC Educational Resources Information Center

    Palmer, Peter M.

    1969-01-01

    The significance of Bergman's "Seventh Seal" lies not in the speeches nor in the actions of the central characters but rather in the film's form, its totality created by the emotive elements of imagery and sound together with the intellectual elements of actions and words. The scene-units are related to a central motif (the opening of…

  6. Gas path seal

    NASA Technical Reports Server (NTRS)

    Bill, R. C.; Johnson, R. D. (Inventor)

    1979-01-01

    A gas path seal suitable for use with a turbine engine or compressor is described. A shroud wearable or abradable by the abrasion of the rotor blades of the turbine or compressor shrouds the rotor bades. A compliant backing surrounds the shroud. The backing is a yieldingly deformable porous material covered with a thin ductile layer. A mounting fixture surrounds the backing.

  7. Composite seal for turbomachinery

    NASA Technical Reports Server (NTRS)

    Bill, R. C.; Ludwig, L. P. (Inventor)

    1980-01-01

    A gas path seal suitable for use with a turbine engine or compressor is provided. A shroud wearable or abradable by the abrasion of the rotor blades of the turbine or compressor shrouds the rotor blades. A compliant backing surrounds the shroud. The backing is a compliant material covered with a thin ductile layer. A mounting fixture surrounds the backing.

  8. Composite seal for turbomachinery

    NASA Technical Reports Server (NTRS)

    Bill, R. C.; Ludwig, L. P. (Inventor)

    1981-01-01

    A gas path seal suitable for use with a turbine engine or compressor is provided. A shroud wearable or abradable by the abrasion of the rotor blades of the turbine or compressor shrouds the rotor blades. A compliant backing surrounds the shroud. The backing is a yieldingly deformable porous material covered with a thin ductile layer. A mounting fixture surrounds the backing.

  9. Ceramic to metal seal

    DOEpatents

    Snow, Gary S.; Wilcox, Paul D.

    1976-01-01

    Providing a high strength, hermetic ceramic to metal seal by essentially heating a wire-like metal gasket and a ceramic member, which have been chemically cleaned, while simultaneously deforming from about 50 to 95 percent the metal gasket against the ceramic member at a temperature of about 30 to 75 percent of the melting temperature of the metal gasket.

  10. Seal for sodium sulfur battery

    DOEpatents

    Topouzian, Armenag; Minck, Robert W.; Williams, William J.

    1980-01-01

    This invention is directed to a seal for a sodium sulfur battery in which the sealing is accomplished by a radial compression seal made on a ceramic component of the battery which separates an anode compartment from a cathode compartment of the battery.

  11. Rim-Supported Turbine Seal

    NASA Technical Reports Server (NTRS)

    Longenecker, Kent O.

    1988-01-01

    Interstage seal accommodates large pressure drop across vane stage. Sealing surfaces close to inner diameter of gas-flow path. Two blade stages supported by single disk, broached over entire width of rim. Seal concept developed for small rocket turbines as liquid-oxygen pumps. Well suited to turbines with high pressure drops across vane stages.

  12. Ultrasonic dip seal maintenance system

    DOEpatents

    Poindexter, Allan M.; Ricks, Herbert E.

    1978-01-01

    A system for removing impurities from the surfaces of liquid dip seals and or 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.

  13. Ceramic-Cord Gas Seal

    NASA Technical Reports Server (NTRS)

    Etzel, C. W.

    1983-01-01

    High-temperature gasket material seals at temperatures above 1,100 degrees C. Concentric exhaust pipes are typical of applications in which ceramic-cord seals might be used. Cord is crushed to form seal between inner and outer pipes when inner pipe is expanded into place. Typical applications include engine exhaust ducts or hot pipes passing through firewalls.

  14. Cryosols Formation and classification in the semiarid Antarctica: the Weddel Sea sector of northern Seymour Island

    NASA Astrophysics Data System (ADS)

    Gjorup, Davi; Schaefer, Carlos; Francelino, Marcio

    2015-04-01

    The Seymour Island is located in the northern sector of the Weddell Sea zone, at the Antarctic Peninsular area, representing a transitional zone between Maritime and Continental Antarctica, with a subpolar, semiarid climate. The Seymour Island is predominantly composed by marine sedimentary rocks of Cretaceus to Eocene age. The aims of this work were to study the chemical, physical, mineralogical and morphological attributes of a selected, representative toposequence of soils at the northern sector of Seymour Island. Soil formation processes and taxonomical implications were discussed. Nine soil profiles were described, collected and analysed, following a toposequence according to different parent materials and landforms. Samples were subjected to textural analysis, routine chemical analysis, chemical extractions by ammonium oxalate and CBD, as well as X ray diffraction. Permafrost is continuous and widespread, generally at depths of less than 100 cm, so the Gelisols order (Soil Taxonomy), or Cryosols (WRB), are the dominant soils. Cryoturbation and organic matter accumulation were not observed. Soils were separated into two groups: acid-sulphate soils and alkaline soils, unaffected by sulphates. The first are the best developed in the study area, meaning a significant physico-chemical and mineralogical alteration. Low pH and high Al saturation and potential acidity are typical. This accounts for primary mineral dissolution, and its absence in the clay fraction. Secondary minerals are those related to sulphide oxidation: soluble and insoluble sulphates, low crystalline Fe-hydroxides and little crystalline Fe phases. The peculiar yellowish colour of these soils are attributed to the presence of Fe-oxides and Jarosite. The presence of 2:1 clays (smectite and illite) in the Clay fraction despite the acidity is due to low leaching. The alkaline soils, non affected by sulphates do not showed any marked weathering or transformation, with high pH, low potential acidity

  15. Analysing subglacial geology hidden beneath the ice streams flowing into the Weddell Sea (West Antarctica)

    NASA Astrophysics Data System (ADS)

    Ferraccioli, F.; King, O.; Jordan, T. A.; Ross, N.; Bingham, R. G.; Le Brocq, A. M.; Smith, A.; Hindmarsh, R. C. A.; Siegert, M. J.

    2014-12-01

    Subglacial geology provides important controls on the onset and maintenance of fast glacial flow in the West Antarctic Ice Sheet (WAIS). Widespread subglacial sediments deposited within deep rift basins, thinner drapes of marine sediments within the West Antarctic Rift System (WARS) and high geothermal heat flux associated with Cenozoic magmatism have been previously identified as key geological controls that can modulate ice sheet dynamics. Here, we compile a suite of new and vintage aeromagnetic and airborne gravity observations to examine the large-scale geological setting of several major ice streams flowing into the Weddell Sea Embayment and assess the role of geological controls on subglacial topography and WAIS flow regimes. We focus on the subglacial geology beneath the Institute and Moeller ice streams, the Rutford ice stream and the Evans ice stream. We show that the Moeller ice stream is underlain by a major strike-slip fault system, which is part of the tectonic boundary between East and West Antarctica. A set of en-echelon subglacial basins formed along the strike-slip fault and these basins appear to steer enhanced flow far inland. Deep sedimentary basins are not present along this fault system, however, suggesting that subglacial sediments are not necessarily a geological template for the onset of fast glacial flow. The recently identified Robin Subglacial Basin that underlies the fast flowing coastal region of the Institute ice stream contains 1-3 km of sedimentary infill and smooth bedrock topography. Enhanced flow in the tributaries of the Institute ice stream cuts across the Ellsworth Mountains and is controlled by basement faults displacing metasedimentary and metavolcanic rocks. Prominent magnetic anomalies overlie outcrops of Jurassic granitic intrusions and enable us to trace their subglacial extent beneath the catchments of Institute, Moeller and Rutford ice streams. These large granitoid bodies form topographic highs that appear to divert

  16. Asteroids, ophiuroids and holothurians from the southeastern Weddell Sea (Southern Ocean).

    PubMed

    Gutt, Julian; Piepenburg, Dieter; Voß, Joachim

    2014-01-01

    Until the early 1980s, the composition and distribution of the asteroid (starfish), ophiuroid (brittle star) and holothurian (sea cucumber) bottom fauna of the southeastern Weddell Sea was virtually unknown. This southernmost part of the Atlantic sector of the Southern Ocean is a typical high-latitude Antarctic region located in the circumpolar permanent pack-ice zone. It became accessible for large-scale scientific surveys only through the availability of modern ice-breaking research vessels, such as the German RV "Polarstern". Here, we describe a dataset of the faunal composition and abundance of starfish, brittle star and sea cucumber assemblages in this area, based on collections from trawl catches carried out during three "Polarstern" cruises in 1983, 1984 and 1985. The set comprises a total of 4,509 records of abundances of 35 asteroid species (with a total of 2,089 specimens) and 38 ophiuroid species (with a total of 18,484 specimens) from 34 stations, as well as of 66 holothurian species (with a total of 20,918 specimens) from 59 stations including zero-abundances (absences). A synthesizing zoogeographical community analysis confirms the presence of three distinct assemblages of asteroids, ophiuroids, and holothurians with highest species richness on the eastern shelf. Overall, starfishes, brittle stars and sea cucumbers were present at all sites investigated in the study area but composition and abundance of asterozoan (asteroids and ophiuroids together) and holothurian fauna varied considerably. A synthesizing zoogeographical community analysis confirms the presence of three distinct assemblages of asteroids, ophiuroids, and holothurians with highest species richness on the eastern shelf. In the case of asterozoans, water depth and latitude seemed to be the most important drivers of assemblage distribution and composition. One of the holothurian assemblages was part of the rich macrozoobenthic community dominated by a diverse and abundant epifauna, mainly

  17. Asteroids, ophiuroids and holothurians from the southeastern Weddell Sea (Southern Ocean)

    PubMed Central

    Gutt, Julian; Piepenburg, Dieter; Voß, Joachim

    2014-01-01

    Abstract Until the early 1980s, the composition and distribution of the asteroid (starfish), ophiuroid (brittle star) and holothurian (sea cucumber) bottom fauna of the southeastern Weddell Sea was virtually unknown. This southernmost part of the Atlantic sector of the Southern Ocean is a typical high-latitude Antarctic region located in the circumpolar permanent pack-ice zone. It became accessible for large-scale scientific surveys only through the availability of modern ice-breaking research vessels, such as the German RV “Polarstern”. Here, we describe a dataset of the faunal composition and abundance of starfish, brittle star and sea cucumber assemblages in this area, based on collections from trawl catches carried out during three “Polarstern” cruises in 1983, 1984 and 1985. The set comprises a total of 4,509 records of abundances of 35 asteroid species (with a total of 2,089 specimens) and 38 ophiuroid species (with a total of 18,484 specimens) from 34 stations, as well as of 66 holothurian species (with a total of 20,918 specimens) from 59 stations including zero-abundances (absences). A synthesizing zoogeographical community analysis confirms the presence of three distinct assemblages of asteroids, ophiuroids, and holothurians with highest species richness on the eastern shelf. Overall, starfishes, brittle stars and sea cucumbers were present at all sites investigated in the study area but composition and abundance of asterozoan (asteroids and ophiuroids together) and holothurian fauna varied considerably. A synthesizing zoogeographical community analysis confirms the presence of three distinct assemblages of asteroids, ophiuroids, and holothurians with highest species richness on the eastern shelf. In the case of asterozoans, water depth and latitude seemed to be the most important drivers of assemblage distribution and composition. One of the holothurian assemblages was part of the rich macrozoobenthic community dominated by a diverse and abundant

  18. Thruster sealing system and apparatus

    NASA Technical Reports Server (NTRS)

    Svejkovsky, Paul A. (Inventor)

    1992-01-01

    A thruster nozzle sealing system and apparatus is provided for protection of spacecraft thruster motors. The system includes a sealing plug, a sealing plug insertion tool, an outer cover, an outer cover attachment, and a ferry flight attachment. The sealing plug prevents moisture from entering the thruster engine so as to prevent valve failure. The attachments are interchangeably connectable with the sealing plug. The ferry flight attachment is used during air transportation of the spacecraft, and the outer cover attachment is used during storage and service of the spacecraft. The outer cover provides protection to the thruster nozzle from mechanical damage.

  19. Seals Having Textured Portions for Protection in Space Environments

    NASA Technical Reports Server (NTRS)

    Daniels, Christopher (Inventor); Garafolo, Nicholas (Inventor)

    2016-01-01

    A sealing construct for a space environment includes a seal-bearing object, a seal on the seal-bearing object, and a seal-engaging object. The seal includes a seal body having a sealing surface, and a textured pattern at the sealing surface, the textured pattern defining at least one shaded channel surface. The seal-engaging object is selectively engaged with the seal-bearing object through the seal. The seal-engaging object has a sealing surface, wherein, when the seal-engaging object is selectively engaged with the seal-bearing object, the sealing surface of the seal-engaging object engages the sealing surface of the seal, and the seal is compressed between the seal-bearing object and the seal-engaging object such that at least one shaded channel surface engages the sealing surface of the seal-engaging object.

  20. Hermetic Seal Leak Detection Apparatus

    NASA Technical Reports Server (NTRS)

    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.

  1. Regenerator cross arm seal assembly

    DOEpatents

    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.

  2. Bellows sealed plug valve

    DOEpatents

    Dukas, Jr., Stephen J.

    1990-01-01

    A bellows sealed plug valve includes a valve body having an inlet passage and an outlet passage, a valve chamber between the inlet and outlet passages. A valve plug has substantially the same shape as the valve chamber and is rotatably disposed therein. A shaft is movable linearly in response to a signal from a valve actuator. A bellows is sealingly disposed between the valve chamber and the valve actuator and means are located between the bellows and the valve plug for converting linear movement of the shaft connected to the valve actuator to rotational movement of the plug. Various means are disclosed including helical thread mechanism, clevis mechanism and rack and pinion mechanism, all for converting linear motion to rotational motion.

  3. Gas turbine sealing apparatus

    SciTech Connect

    Wiebe, David J; Wessell, Brian J; Ebert, Todd; Beeck, Alexander; Liang, George; Marussich, Walter H

    2013-02-19

    A gas turbine includes forward and aft rows of rotatable blades, a row of stationary vanes between the forward and aft rows of rotatable blades, an annular intermediate disc, and a seal housing apparatus. The forward and aft rows of rotatable blades are coupled to respective first and second portions of a disc/rotor assembly. The annular intermediate disc is coupled to the disc/rotor assembly so as to be rotatable with the disc/rotor assembly during operation of the gas turbine. The annular intermediate disc includes a forward side coupled to the first portion of the disc/rotor assembly and an aft side coupled to the second portion of the disc/rotor assembly. The seal housing apparatus is coupled to the annular intermediate disc so as to be rotatable with the annular intermediate disc and the disc/rotor assembly during operation of the gas turbine.

  4. Sealing Nitrogen Tetroxide Leaks

    NASA Technical Reports Server (NTRS)

    Garrard, George G.; Houston, Donald W.; Scott, Frank D.

    1990-01-01

    Use of Furmanite FSC-N-6B sealant in clam-shell sealing device makes it possible to stop leaks of nitrogen tetroxide through defective or improperly-seated plumbing fittings. Devised to stop leaks in vent line of small rocket motor on Space Shuttle. Also used on plumbing containing hydrazine and other hazardous fluids, and repair withstands severe temperature, vibration, and shock. Leaks stopped in place, without draining or replacement of leaking parts.

  5. Origin, distribution and glaciological implications of Jurassic high heat production granites in the Weddell Sea rift, Antarctica

    NASA Astrophysics Data System (ADS)

    Leat, Phil T.; Jordan, Tom A. R. M.; Ferraccioli, Fausto; Flowerdew, Michael; R, Riley, Teal; Vaughan, Alan P. M.; Whitehouse, Martin

    2013-04-01

    The distribution of heat flow in Antarctic continental crust is critical to understanding ice sheet nucleation, growth and basal rheology and hydrology. We identify a group of High Heat Production granites intruded into Palaeozoic sedimentary sequences which may contribute to locally high heat flow beneath the central part of the West Antarctic Ice Sheet. Four of the granite plutons are exposed above ice sheet level at Pagano Nunatak, Pirrit Hills, Nash Hills and Whitmore Mountains. A new U-Pb zircon age from Pirrit Hills of 177.9 ± 2.3 Ma confirms earlier Rb-Sr dating that suggested an Early-Middle Jurassic age for the granites, coincident with the Karoo-Ferrar large igneous province and the first stage of Gondwana break-up. Our recently-acquired aerogeophysical data indicate that the plutons are distributed unevenly over 1000 km2 and were intruded into the actively extending, locally transcurrent, Jurassic Weddell Sea Rift [1]. In the NW part of the rift, the Pirrit Hills, Nash Hills and Whitmore Mountains granites form small isolated intrusions within weakly deformed upper crust. In the SE part of the rift, where granite intrusion was strongly structurally controlled within transtensional structures, the Pagano Nunatak granite is the only outcrop of a probably multiphase, ca 180 km long granite intrusion. The granites are weakly peraluminous, S-type and have Th and U abundances up to 61 and 19 ppm respectively. Heat production of analysed granite samples is ca. 2.9-9.1 µWm-3, toward the upper limit of values for High Heat Production granites globally. The granites are thought to have been generated during mafic underplating of the Weddell Rift during eruption of the contemporaneous Karoo-Ferrar magmatism [2]. The high Th and U abundances may be related to fractionation of the high Th-U Ferrar basaltic magmas combined with assimilation of pelitic sedimentary rocks. The granites correspond to an area of West Antarctica that may have heat flow significantly above

  6. Sustained observations in the Weddell Sea spanning more than 20 years show gradual increase of the deep water heat content

    NASA Astrophysics Data System (ADS)

    Strass, Volker; Rohardt, Gerd; Hoppema, Mario

    2014-05-01

    Beginning in 1989, Eberhard Fahrbach established and maintained until his premature death an observational programme in the Weddell Sea, which outstandingly contributed to alleviate the grave problem of undersampling of the Southern Ocean. Continuation of his legacy by the Alfred-Wegener-Institut has yielded a time series that now extends into 2013, hence covers almost 24 years. Here we analyse this data set for long-term changes of the heat content in the deep Weddell Sea. We exclusively evaluate the calibrated temperature records obtained with ship-lowered CTD (conductivity-temperature-depth sonde) casts at repeated hydrographic stations and along repeated sections. Using this approach we avoid introducing potential temperature offsets that can result from combination of different measurement technologies and potential biases resultant from differences in geographic positions. Our results show that the deep water masses below 700 m gradually warmed over the past two decades by 0.001 - 0.004 K a-1. Superimposed inter-annual to multi-annual variations appear as largely uncorrelated horizontally across the Weddell Gyre. The long-term (21 - 24 years) trends of increasing temperatures in different depth layers below 700 m at all stations and sections can be approximated by linear regression that explains between 27 and 91 % of the variance, where the coefficients of correlation tend to increase with depth. No significant trends are found in the top 700 m. The heating rate of the water masses below 700 m is estimated to 0.79 ± 0.14 W m-2, which is more than twice as high as determined for the global deep ocean in general. Our results hence corroborate the view that Southern Ocean processes make an above-average contribution to the deep ocean warming, and so add to bring global estimates of the deep ocean heating rate and of the net energy flux into the Earth's climate system at the top of the atmosphere of 0.5 - 1 W m-2 closer in line with each other. Thus they help

  7. Navy GTE seal development activity

    NASA Technical Reports Server (NTRS)

    Grala, Carl P.

    1993-01-01

    Under the auspices of the Integrated High Performance Turbine Engine Technology Initiative, the Naval Air Warfare Center conducts advanced development programs for demonstration in the next generation of air-breathing propulsion systems. Among the target technologies are gas path and lube oil seals. Two development efforts currently being managed by NAWCAD are the High Performance Compressor Discharge Film-Riding Face Seal and the Subsonic Core High Speed Air/Oil Seal. The High Performance Compressor Discharge Film-Riding Face Seal Program aims at reducing parasitic leakage through application of a film-riding face sea concept to the compressor discharge location of a Phase 2 IHPTET engine. An order-of-magnitude leakage reduction relative to current labyrinth seal configurations is expected. Performance goals for these seals are (1) 1200 F air temperature, (2) 800 feet-per-second surface velocity, and (3) 600 SPI differential pressure. The two designs chosen for fabrication and rig test are a spiral groove and a Rayleigh step seal. Rig testing is currently underway. The Subsonic Core High Speed Air/Oil Seal Program is developing shaft-to-ground seals for next-generation propulsion systems that will minimize leakage and provide full life. Significantly higher rotor speeds and temperatures will be experienced. Technologies being exploited include, hydrodynamic lift assist features, ultra light weight designs, and improved cooling schemes. Parametric testing has been completed; a final seal design is entering the endurance test phase.

  8. Navy GTE seal development activity

    NASA Astrophysics Data System (ADS)

    Grala, Carl P.

    1993-10-01

    Under the auspices of the Integrated High Performance Turbine Engine Technology Initiative, the Naval Air Warfare Center conducts advanced development programs for demonstration in the next generation of air-breathing propulsion systems. Among the target technologies are gas path and lube oil seals. Two development efforts currently being managed by NAWCAD are the High Performance Compressor Discharge Film-Riding Face Seal and the Subsonic Core High Speed Air/Oil Seal. The High Performance Compressor Discharge Film-Riding Face Seal Program aims at reducing parasitic leakage through application of a film-riding face sea concept to the compressor discharge location of a Phase 2 IHPTET engine. An order-of-magnitude leakage reduction relative to current labyrinth seal configurations is expected. Performance goals for these seals are (1) 1200 F air temperature, (2) 800 feet-per-second surface velocity, and (3) 600 SPI differential pressure. The two designs chosen for fabrication and rig test are a spiral groove and a Rayleigh step seal. Rig testing is currently underway. The Subsonic Core High Speed Air/Oil Seal Program is developing shaft-to-ground seals for next-generation propulsion systems that will minimize leakage and provide full life. Significantly higher rotor speeds and temperatures will be experienced. Technologies being exploited include, hydrodynamic lift assist features, ultra light weight designs, and improved cooling schemes. Parametric testing has been completed; a final seal design is entering the endurance test phase.

  9. Closure and Sealing Design Calculation

    SciTech Connect

    T. Lahnalampi; J. Case

    2005-08-26

    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

  10. TECHNOLOGY ROADMAPPING FOR IAEA SEALS.

    SciTech Connect

    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 presentation will include a

  11. Pneumatic stowing seals mines

    SciTech Connect

    Brezovec, D.

    1983-11-01

    A mechanized technique to seal abandoned mines has been used successfully to close 13 openings at Duquesne Light Co.'s mined-out Warwick No. 2 mine, near Greensboro, Pa. The mechanized system, which uses a pneumatic stower and crushed limestone, closed the entries more economically and in less time than it would have taken to install traditional concrete block stopping and clay plug seals, according to John C. Draper. Draper, a mining engineer with Duquesne Light's coal department, was in charge of installing the Warwick seals in a Bureau of Mines-sponsored field test on the pneumatic sealing technique. The lowest estimated cost for installing conventional stopping and plug closures for the 13 Warwick openings was $225,000, says Draper, while the openings were closed using the mechanized system for $245,000. Draper says the newer stopping cost more in the instance because work was stopped often to gather information for the experiment. The experimental closures were installed in 38 days. The job would have taken at least 149 days if traditional closures were being installed, Draper say. To install a traditional concrete block/clay plug closure, the mine opening must be cleaned thoroughly and the roof must be supported for some 3 ft from the outside. Then a solid wall or stopping must be built 25 ft from the surface and the entry must be packed with clay to the surface. Much of this job requires workers to remain underground. In pneumatic stowing, 1 1/2-in. crushed limestone with fines is conveyed through a pipeline and into the mine opening under low air pressure. Watertight seals can be installed by blowing about 10 ft of rock into the opening against the top to act as roof support. Safety posts are installed and about 10 or 15 ft of mine entry is cleaned. About 2 in. of raw cement or bentonite is placed on the floor and limestone mixed with dry cement or bentonite is blown into the opening.

  12. Canister, Sealing Method And Composition For Sealing A Borehole

    SciTech Connect

    Brown, Donald W.; Wagh, Arun S.

    2005-06-28

    Method and composition for sealing a borehole. A chemically bonded phosphate ceramic sealant for sealing, stabilizing, or plugging boreholes is prepared by combining an oxide or hydroxide and a phosphate with water to form slurry. The slurry is introduced into the borehole where the seal, stabilization or plug is desired, and then allowed to set up to form the high strength, minimally porous sealant, which binds strongly to itself and to underground formations, steel and ceramics.

  13. QwikSeal (registered trademark) Pre-Sealed Aerospace Fasteners

    DTIC Science & Technology

    2012-08-29

    UV - curable and solvent-based systems being evaluated – New application methodology being integrated onto QwikSeal production machine Automated...materials with a wide range of viscosities – Solvent based and 100% solids UV - curable materials can both be sprayed with fine control • Bench top...Std Z39-18 Overview 2 Background Sealant Barrier Coat PCI ESTCP Program Integration • QwikSeal Background – Problem – QwikSeal Solution

  14. High temperature braided rope seals for static sealing applications

    NASA Technical Reports Server (NTRS)

    Adams, Michael L.; Olsen, Andrew; Darolia, Ram; Steinetz, Bruce M.; Bartolotta, Paul A.

    1996-01-01

    Achieving efficiency and performance goals of advanced aircraft and industrial systems are leading designers to implement high temperature materials such as ceramics and intermetallics. Generally these advanced materials are applied selectively in the highest temperature sections of the engine system including the combustor and high pressure turbine, amongst others. Thermal strains that result in attaching the low expansion-rate components to high expansion rate superalloy structures can cause significant life reduction in the components. Seals are being designed to both seal and to serve as compliant mounts allowing for relative thermal growths between high temperature but brittle primary structures and the surrounding support structures. Designers require high temperature, low-leakage, compliant seals to mitigate thermal stresses and control parasitic and cooling airflow between structures. NASA is developing high temperature braided rope seals in a variety of configurations to help solve these problems. This paper will describe the types of seals being developed, describe unique test techniques used to assess seal performance, and present leakage flow data under representative pressure, temperature and scrubbing conditions. Feasibility of the braided rope seals for both an industrial tube seal and a turbine vane seal application is also demonstrated.

  15. Setting properties and sealing ability of hydraulic temporary sealing materials.

    PubMed

    Ogura, Yoko; Katsuumi, Ichiroh

    2008-09-01

    This study sought to investigate the setting progress and sealing ability of hydraulic temporary sealing materials used in endodontic treatment: Lumicon, Caviton, and HY-Seal. To evaluate setting progress, the materials were filled into glass tubes with one end sealed and immersed in water. After immersion, a measurement apparatus was inserted from the non-immersed end and the set area was determined by subtracting the unset area from the sample thickness. To evaluate sealing ability, materials were filled into glass tubes and divided into four groups based on different immersion times. Thermal cycling and dye penetration were performed. At 7 days, the setting depths of HY-Seal and Caviton were almost equivalent to full sample thickness, while that of Lumicon was only half of full sample thickness (p < 0.01). On sealing ability, Lumicon ranked the highest followed by Caviton, whereas HY-Seal was unstable (p < 0.01). These results suggested that there was no correlation between setting progress and sealing ability.

  16. Acoustic insights into the zooplankton dynamics of the eastern Weddell Sea

    NASA Astrophysics Data System (ADS)

    Cisewski, Boris; Strass, Volker H.

    2016-05-01

    The success of any efforts to determine the effects of climate change on marine ecosystems depends on understanding in the first instance the natural variations, which contemporarily occur on the interannual and shorter time scales. Here we present results on the environmental controls of zooplankton distribution patterns and behaviour in the eastern Weddell Sea, Southern Ocean. Zooplankton abundance and vertical migration are derived from the mean volume backscattering strength (MVBS) and the vertical velocity measured by moored acoustic Doppler current profilers (ADCPs), which were deployed simultaneously at 64°S, 66.5°S and 69°S along the Greenwich Meridian from February, 2005, until March, 2008. While these time series span a period of full three years they resolve hourly changes. A highly persistent behavioural pattern found at all three mooring locations is the synchronous diel vertical migration (DVM) of two distinct groups of zooplankton that migrate between a deep residence depth during daytime and a shallow depth during nighttime. The DVM was closely coupled to the astronomical daylight cycles. However, while the DVM was symmetric around local noon, the annual modulation of the DVM was clearly asymmetric around winter solstice or summer solstice, respectively, at all three mooring sites. DVM at our observation sites persisted throughout winter, even at the highest latitude exposed to the polar night. Since the magnitude as well as the relative rate of change of illumination is minimal at this time, we propose that the ultimate causes of DVM separated from the light-mediated proximal cue that coordinates it. In all three years, a marked change in the migration behaviour occurred in late spring (late October/early November), when DVM ceased. The complete suspension of DVM after early November is possibly caused by the combination of two factors: (1) increased availability of food in the surface mixed layer provided by the phytoplankton spring bloom, and

  17. Low post-glacial rebound rates in the Weddell Sea due to Late Holocene ice-sheet readvance

    NASA Astrophysics Data System (ADS)

    Bradley, Sarah L.; Hindmarsh, Richard C. A.; Whitehouse, Pippa; Bentley, Michael J.; King, Matt

    2014-05-01

    The Holocene deglaciation of West Antarctica resulted in widespread ice surface lowering. While many ice-sheet reconstructions generally assume a monotone Holocene retreat for the West Antarctica Ice sheet (WAIS) [Ivins et al., 2013; Peltier, 2004; Whitehouse et al., 2012], an increasing number of glaciological observations infer it is readvancing, following retreat behind the present-day margin[Siegert et al., 2013]. We will show that a readvance in the Weddell Sea region can reconcile two outstanding problems: (i) the present-day widespread occurrence of seemingly stable ice-streams grounded on beds that deepen inland in apparent contradiction to theory [Schoof, 2007]; and (ii) the inability of models of Glacial Isostatic Adjustment (GIA) to match present-day uplift rates [Whitehouse et al., 2012]. Combining a suite of ice loading histories that include a readvance with a model of GIA provides significant improvements to predictions of present-day uplift rates, and we are able to reproduce previously unexplained observations of subsidence in the southern sector of the Weddell Sea. We hypothesize that retreat behind present grounding lines occurred when the bed was lower, and isostatic recovery led to shallowing, ice sheet re-grounding and readvance. We will conclude that some sections of the current WAIS grounding line that are theoretically unstable, may be advancing and that the volume change of the WAIS may have been more complex in the Late Holocene than previously posited. This revised Holocene ice-loading history would have important implications for the GIA correction applied to Gravity Recovery and Climate Experiment (GRACE) data, likely resulting in a reduction in the GIA correction and a smaller estimate of present-day ice mass loss within the Weddell Sea region of the WAIS. Ivins, E. R., T. S. James, J. Wahr, E. J. O. Schrama, F. W. Landerer, and K. M. Simon (2013), Antarctic contribution to sea level rise observed by GRACE with improved GIA correction

  18. A new monothalamous foraminiferan from 1000 to 6300 m water depth in the Weddell Sea: morphological and molecular characterisation

    NASA Astrophysics Data System (ADS)

    Gooday, Andrew J.; Holzmann, Maria; Guiard, Jackie; Cornelius, Nils; Pawlowski, Jan

    2004-07-01

    We describe Bathyallogromia weddellensis gen. & sp. nov., a deep-water, monothalamous foraminiferan from bathyal and abyssal sites in the western Weddell Sea. The species is characterised by a delicate, almost spherical, organic-walled test, a low, broad projecting apertural region, and light grey or greenish cytoplasm containing mineral grains and other inclusions. Molecular phylogenetic analyses, based on small subunit rRNA gene sequences, indicate that Bathyallogromia is an independent lineage branching within a clade of monothalamous foraminiferans, which also includes such genera as Saccammina, Gloiogullmia, Cylindrogullmia, Rhabdammina, Toxisarcon and Pilulina (?). Lack of significant genetic differences between specimens collected at depths ranging from 1000 to 6300 m suggests that B. weddellensis is adapted to conditions that span a broad bathymetric range.

  19. Seals cap rotary kiln emissions

    SciTech Connect

    Gunkle, D.W. )

    1993-09-01

    The possibility of producing fugitive emissions is one of the most critical aspects of an incineration system. Whether such a system processes hazardous, medical, mixed or municipal waste, fugitive emissions are of special concern to system operators and the public alike. Effectively designed rotary-kiln seals can reduce fugitive emissions to acceptable, minimal levels. Modern air monitoring systems track incineration site emissions. Possible emissions sources include excavation and transfer sites, storage areas, material-feed systems, rotary kiln seals, and exhaust stacks. Several options are available for rotary-kiln seals. Six are discussed here: labyrinth; overlapping spring plate; graphite block; pneumatic; shrouded; and overpressure. Kiln seals are used to prevent process gases from escaping or ambient air from entering a rotary kiln uncontrolled. They are not designed to function as material seals, or prevent spills of solids or liquids. Seal design involves considering differential pressure produced by a kiln's internal-to-external temperature, pressure excursions (explosions) and material spills.

  20. Metal to ceramic sealed joint

    DOEpatents

    Lasecki, J.V.; Novak, R.F.; McBride, J.R.

    1991-08-27

    A metal to ceramic sealed joint which can withstand wide variations in temperature and maintain a good seal is provided for use in a device adapted to withstand thermal cycling from about 20 to about 1000 degrees C. The sealed joint includes a metal member, a ceramic member having an end portion, and an active metal braze forming a joint to seal the metal member to the ceramic member. The joint is positioned remote from the end portion of the ceramic member to avoid stresses at the ends or edges of the ceramic member. The sealed joint is particularly suited for use to form sealed metal to ceramic joints in a thermoelectric generator such as a sodium heat engine where a solid ceramic electrolyte is joined to metal parts in the system. 11 figures.

  1. Metal to ceramic sealed joint

    DOEpatents

    Lasecki, John V.; Novak, Robert F.; McBride, James R.

    1991-01-01

    A metal to ceramic sealed joint which can withstand wide variations in temperature and maintain a good seal is provided for use in a device adapted to withstand thermal cycling from about 20 to about 1000 degrees C. The sealed joint includes a metal member, a ceramic member having an end portion, and an active metal braze forming a joint to seal the metal member to the ceramic member. The joint is positioned remote from the end portion of the ceramic member to avoid stresses at the ends or edges of the ceramic member. The sealed joint is particularly suited for use to form sealed metal to ceramic joints in a thermoelectric generator such as a sodium heat engine where a solid ceramic electrolyte is joined to metal parts in the system.

  2. Aft outer rim seal arrangement

    SciTech Connect

    Lee, Ching-Pang; Tham, Kok-Mun; Schroeder, Eric; Meeroff, Jamie; Miller, Jr., Samuel R; Marra, John J; Campbell, Christian X

    2015-04-28

    An outer rim seal arrangement (10), including: an annular rim (70) centered about a longitudinal axis (30) of a rotor disc (31), extending fore and having a fore-end (72), an outward-facing surface (74), and an inward-facing surface (76); a lower angel wing (62) extending aft from a base of a turbine blade (22) and having an aft end (64) disposed radially inward of the rim inward-facing surface to define a lower angel wing seal gap (80); an upper angel wing (66) extending aft from the turbine blade base and having an aft end (68) disposed radially outward of the rim outward-facing surface to define a upper angel wing seal gap (80, 82); and guide vanes (100) disposed on the rim inward-facing surface in the lower angel wing seal gap. Pumping fins (102) may be disposed on the upper angel wing seal aft end in the upper angel wing seal gap.

  3. Rim seal for turbine wheel

    DOEpatents

    Glezer, Boris; Boyd, Gary L.; Norton, Paul F.

    1996-01-01

    A turbine wheel assembly includes a disk having a plurality of blades therearound. A ceramic ring is mounted to the housing of the turbine wheel assembly. A labyrinth rim seal mounted on the disk cooperates with the ceramic ring to seal the hot gases acting on the blades from the disk. The ceramic ring permits a tighter clearance between the labyrinth rim seal and the ceramic ring.

  4. Immunogenetics of the Elephant Seal

    NASA Technical Reports Server (NTRS)

    Garza, John Carlos

    1999-01-01

    The goals of this cooperative agreement fall into three categories: 1) A basic description of Immunogenetic variation in the northern elephant seal genome; 2) A basic genetic map of the northern elephant seal genome; 3). Microevolutionary forces in the northern elephant seal genome. The results described in this report were acquired using funds from this cooperative agreement together with funds from a National Science Foundation Dissertation Improvement Grant.

  5. Low-Torque Seal Development

    NASA Technical Reports Server (NTRS)

    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.

  6. 30 CFR 57.8535 - Seals.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....8535 Seals. Seals shall be provided with a means for checking the quality of air behind the seal and a means to prevent a water head from developing unless the seal is designed to impound water. ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Seals. 57.8535 Section 57.8535...

  7. 19 CFR 113.25 - Seals.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Seals. 113.25 Section 113.25 Customs Duties U.S... Bond Requirements § 113.25 Seals. When a seal is required, the seal shall be affixed adjoining the signatures of principal and surety, if individuals, and the corporate seal shall be affixed close to...

  8. 19 CFR 113.25 - Seals.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Seals. 113.25 Section 113.25 Customs Duties U.S... Bond Requirements § 113.25 Seals. When a seal is required, the seal shall be affixed adjoining the signatures of principal and surety, if individuals, and the corporate seal shall be affixed close to...

  9. 19 CFR 113.25 - Seals.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Seals. 113.25 Section 113.25 Customs Duties U.S... Bond Requirements § 113.25 Seals. When a seal is required, the seal shall be affixed adjoining the signatures of principal and surety, if individuals, and the corporate seal shall be affixed close to...

  10. 19 CFR 113.25 - Seals.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Seals. 113.25 Section 113.25 Customs Duties U.S... Bond Requirements § 113.25 Seals. When a seal is required, the seal shall be affixed adjoining the signatures of principal and surety, if individuals, and the corporate seal shall be affixed close to...

  11. 19 CFR 113.25 - Seals.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Seals. 113.25 Section 113.25 Customs Duties U.S... Bond Requirements § 113.25 Seals. When a seal is required, the seal shall be affixed adjoining the signatures of principal and surety, if individuals, and the corporate seal shall be affixed close to...

  12. Borehole sealing method and apparatus

    DOEpatents

    Hartley, James N.; Jansen, Jr., George

    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.

  13. Electrodes for sealed secondary batteries

    NASA Technical Reports Server (NTRS)

    Boies, D. B.; Child, F. T.

    1972-01-01

    Self-supporting membrane electrode structures, in which active ingredients and graphite are incorporated in a polymeric matrix, improve performance of electrodes in miniature, sealed, alkaline storage batteries.

  14. Internal coaxial cable seal system

    DOEpatents

    Hall, David R.; Sneddon, Cameron; Dahlgren, Scott Steven; Briscoe, Michael A.

    2006-07-25

    The invention is a seal system for a coaxial cable and is placed within the coaxial cable and its constituent components. A series of seal stacks including load ring components and elastomeric rings are placed on load bearing members within the coaxial cable sealing the annular space between the coaxial cable and an electrical contact passing there through. The coaxial cable is disposed within drilling components to transmit electrical signals between drilling components within a drill string. The seal system can be used in a variety of downhole components, such as sections of pipe in a drill string, drill collars, heavy weight drill pipe, and jars.

  15. Pressure sensor for sealed containers

    DOEpatents

    Hodges, Franklin R.

    2001-01-01

    A magnetic pressure sensor for sensing a pressure change inside a sealed container. The sensor includes a sealed deformable vessel having a first end attachable to an interior surface of the sealed container, and a second end. A magnet mounted to the vessel second end defining a distance away from the container surface provides an externally detectable magnetic field. A pressure change inside the sealed container causes deformation of the vessel changing the distance of the magnet away from the container surface, and thus the detectable intensity of the magnetic field.

  16. Advanced High Temperature Structural Seals

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  17. SEAL FOR HIGH SPEED CENTRIFUGE

    DOEpatents

    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.

  18. High Temperature Hydraulic Seals

    DTIC Science & Technology

    1993-05-01

    test rods were made from PH13 - 8 Mo corrosion resistant steel, hardened to Rc=45. Two unsuccessful attempts were made to test the rod seals. In both...BARRELS MATERIAL AND HEAT TREAT NOTES: 1. Material shall be 2-3/ 8 inch diameter PH13 -8Mo stainless steel bars per AMS 5629, purchased in condition "A...s PE-62203 PR-3145 6. AUTHOR(S) TA- 30 K. R. Williams WU-45 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8 . PERFORMING ORGANIZATION REPORT

  19. Mechanical Face Seal Dynamics.

    DTIC Science & Technology

    1985-12-01

    Fig. 4(a)]. The axial runout at the tuter radius 6- TABLE 1: PARAMWtIER VALUlFS FOiR THE. SINtGt.t PER UtLRimAlTIN Scin.i’ IIN SCIIEI;Mt Mass, m,n kg...critical rotor runout are presented. It is shown that the more simple to use small perturbation analysis gives very good results for most practical...stiffness and damping coefficients i : are not constants. In the case of seal-rotor runout , the stiffness and damping coefficients of the elastomer are

  20. Advanced Duct Sealing Testing

    SciTech Connect

    Sherman, Max H.; Walker, Iain S.

    2003-08-01

    Duct leakage has been identified as a major source of energy loss in residential buildings. Most duct leakage occurs at the connections to registers, plenums or branches in the duct system. At each of these connections a method of sealing the duct system is required. Typical sealing methods include tapes or mastics applied around the joints in the system. Field examinations of duct systems have typically shown that these seals tend to fail over extended periods of time. The Lawrence Berkeley National Laboratory has been testing sealant durability for several years. Typical duct tape (i.e. fabric backed tapes with natural rubber adhesives) was found to fail more rapidly than all other duct sealants. This report summarizes the results of duct sealant durability testing of five UL 181B-FX listed duct tapes (three cloth tapes, a foil tape and an Oriented Polypropylene (OPP) tape). One of the cloth tapes was specifically developed in collaboration with a tape manufacturer to perform better in our durability testing. The first test involved the aging of common ''core-to-collar joints'' of flexible duct to sheet metal collars, and sheet metal ''collar-to-plenum joints'' pressurized with 200 F (93 C) air. The second test consisted of baking duct tape specimens in a constant 212 F (100 C) oven following the UL 181B-FX ''Temperature Test'' requirements. Additional tests were also performed on only two tapes using sheet metal collar-to-plenum joints. Since an unsealed flexible duct joint can have a variable leakage depending on the positioning of the flexible duct core, the durability of the flexible duct joints could not be based on the 10% of unsealed leakage criteria. Nevertheless, the leakage of the sealed specimens prior to testing could be considered as a basis for a failure criteria. Visual inspection was also documented throughout the tests. The flexible duct core-to-collar joints were inspected monthly, while the sheet metal collar-to-plenum joints were inspected

  1. The acoustic reflex in children without an hermetic seal.

    PubMed

    Kaplan, H; Babecki, S; Thomas, C

    1980-01-01

    In clinical practice with children, the hermetic seal is either often not obtainable or is lost before acoustic reflex measures are obtained. In a recent study, Surr and Schuchman (Archives of Otolaryngology 102, 160--161, 1976.) found that in the majority of cases reflex thresholds could be measured in adults with normal middle ears in the absence of an hermetic seal. This study was designed to find out whether the conclusions of Surr and Schuchman could be extended to children. Sealed and unsealed reflexes were compared in 30 children, ages 3 to 7, with normal middle ears. Results indicated that: (1) approximately two-thirds of the children demonstrated reflexes in the unsealed condition; (2) differences between sealed and unsealed reflex thresholds were not clinically significant; (3) in most cases, unsealed reflexes were measurable at all frequencies or at none; (4) neither size of ear canal volume nor amplitude of the sealed reflex at 10 dB SL seemed to be related to the presence or absence of the unsealed reflex. It was concluded that reflex thresholds obtained in the absence of an hermetic seal may be considered valid but the absence of an unsealed reflex should not be considered diagnostically significant.

  2. Levels and temporal trends of HCH isomers in ringed seals from West and East Greenland.

    PubMed

    Rigét, Frank; Vorkamp, Katrin; Dietz, Rune; Muir, Derek C G

    2008-08-01

    Levels and temporal trends of the hexachlorocyclohexane isomers alpha-, beta- and gamma-HCH were analysed in blubber of juvenile ringed seals from West Greenland (1994 to 2006) and juvenile and adult ringed seals from East Greenland (1986 to 2006). No significant differences in the concentration levels in the juvenile seals were found between East and West Greenland for any of the three isomers. alpha-HCH concentrations were not significantly different between juvenile and adult ringed seals from East Greenland, whereas beta- and gamma-HCH concentrations were significantly higher in adult ringed seals. alpha- and beta-HCH in Greenland ringed seals were approximately a factor two lower than in the Canadian Arctic, and alpha-HCH was a factor 2-3 higher than in ringed seals from an area east of Svalbard, Norway. Annual decreases in ringed seals from Greenland during the study periods were detected to be 9.1-11.7%, 1.4-3.9% and 6.0-6.4% for alpha-, beta- and gamma-HCH, respectively, being quite similar in both East and West Greenland. Similar levels and trends in East and West Greenland support the general understanding of the pathways of HCH isomers to and in the Arctic.

  3. Disperser seal and method

    SciTech Connect

    Johnston, R. T.

    1981-06-02

    A seal is described for a shaft of a disperser crusher, that pulverizes hot coal particles, maintains a higher than atmospheric pressure within a casing for the crusher, and is able to withstand elevated temperatures that are produced within the casing. The pressure and temperature result from hot gases that convey coal particles to the crusher. The seal includes self lubricating graphite packings that are urged in abutting relation with a smooth, ceramic sleeve on the shaft and are able to withstand the temperature on the shaft surface. A first, interior packing is on the inside of a wall of the casing while a second, exterior packing is outside of the wall. Superheated steam, a gas inert with the coal particles, is supplied to the interior packing with sufficient pressure to substantially prevent the migration of coal particles through the interior packing. The tendency of the coal particles to migrate from the container through the interior packing is further inhibited by providing a tortuous path from the casing to the interior packing.

  4. Persistent organic pollutant patterns in grey seals (Halichoerus grypus).

    PubMed

    Roots, O; Zitko, V; Roose, A

    2005-08-01

    The aim of this paper is to examine the patterns of polychlorinated biphenyls (PCB) in the grey seals (Halichoerus grypus) from the Baltic, Northeast and Eastern England, and the St. Lawrence Estuary (Canada). In fact, the feeding habits of the ringed seal (Phoca hispida) include ingestion of major quantities of benthic crustaceans that might cause observed differences obtained in PCBs, whereas the grey seal feed mainly on fish. The profile (percent in mixture) of polychlorinated biphenyls (PCB) 101, 118, 138, 153, and 180, and the total of their concentrations in mg/kg lipid in grey seals from the Baltic, from Northeast and Eastern England, and from the St. Lawrence estuary (Canada), were examined by principal component analysis (PCA). When considering the possible effects of consuming seafood by the grey seal, it is necessary to characterize populations and individuals according to the amounts they consume, since populations in different parts of the world are likely to show big differences in their consumption of seafood. The patterns differ between juveniles and adult animals, but the gender of adults and geography do not appear to play a role.

  5. Seal between metal and ceramic conduits

    DOEpatents

    Underwood, Richard Paul; Tentarelli, Stephen Clyde

    2015-02-03

    A seal between a ceramic conduit and a metal conduit of an ion transport membrane device consisting of a sealing surface of ceramic conduit, a sealing surface of ceramic conduit, a single gasket body, and a single compliant interlayer.

  6. Toward an Improved Hypersonic Engine Seal

    NASA Technical Reports Server (NTRS)

    Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; DeMange,Jeffrey J.; Taylor, Shawn C.

    2003-01-01

    High temperature, dynamic seals are required in advanced engines to seal the perimeters of movable engine ramps for efficient, safe operation in high heat flux environments at temperatures from 2000 to 2500 F. Current seal designs do not meet the demanding requirements for future engines, so NASA s Glenn Research Center (GRC) is developing advanced seals to overcome these shortfalls. Two seal designs and two types of seal preloading devices were evaluated in a series of compression tests at room temperature and 2000 F and flow tests at room temperature. Both seals lost resiliency with repeated load cycling at room temperature and 2000 F, but seals with braided cores were significantly more flexible than those with cores composed of uniaxial ceramic fibers. Flow rates for the seals with cores of uniaxial fibers were lower than those for the seals with braided cores. Canted coil springs and silicon nitride compression springs showed promise conceptually as potential seal preloading devices to help maintain seal resiliency.

  7. Ceramic-to-metal vacuum seal

    NASA Technical Reports Server (NTRS)

    Sackerlotzky, O. H.

    1979-01-01

    Knife-edge sealing technique forms reliable, vacuum-tight bonds between materials having very different thermal-expansion characteristics. Seal is thin and flexible and absorb shear, hoop, and bonding stresses at joint so that seal remains vacuum tight.

  8. Compliant high temperature seals for dissimilar materials

    DOEpatents

    Rynders, Steven Walton; Minford, Eric; Tressler, Richard Ernest; Taylor, Dale M.

    2001-01-01

    A high temperature, gas-tight seal is formed by utilizing one or more compliant metallic toroidal ring sealing elements, where the applied pressure serves to activate the seal, thus improving the quality of the seal. The compliant nature of the sealing element compensates for differences in thermal expansion between the materials to be sealed, and is particularly useful in sealing a metallic member and a ceramic tube art elevated temperatures. The performance of the seal may be improved by coating the sealing element with a soft or flowable coating such as silver or gold and/or by backing the sealing element with a bed of fine powder. The material of the sealing element is chosen such that the element responds to stress elastically, even at elevated temperatures, permitting the seal to operate through multiple thermal cycles.

  9. Face-Sealing Butterfly Valve

    NASA Technical Reports Server (NTRS)

    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.

  10. Liquid trap seals thermocouple leads

    NASA Technical Reports Server (NTRS)

    Ruppe, E. P.

    1966-01-01

    Liquid trap seals thermocouple leads coming out of a brazing retort that operates with a controlled atmosphere so that air cannot enter the retort and hydrogen cannot escape. The trap is fastened to a duct welded to the retort. Thermocouple leads are led out through the duct and trap, with the fluid forming a gastight seal between the atmosphere and the retort.

  11. Rotating plug bearing and seal

    DOEpatents

    Wade, Elman E.

    1977-01-01

    A bearing and seal structure for nuclear reactors utilizing rotating plugs above the nuclear reactor vessel. The structure permits lubrication of bearings and seals of the rotating plugs without risk of the lubricant draining into the reactor vessel below. The structure permits lubrication by utilizing a rotating outer race bearing.

  12. Conical O-ring seal

    DOEpatents

    Chalfant, Jr., Gordon G.

    1984-01-01

    A shipping container for radioactive or other hazardous materials which has a conical-shaped closure containing grooves in the conical surface thereof and an O-ring seal incorporated in each of such grooves. The closure and seal provide a much stronger, tighter and compact containment than with a conventional flanged joint.

  13. Boltless Seal for Electronic Housings

    NASA Technical Reports Server (NTRS)

    Dawe, R. H.; Evans, J. T.

    1982-01-01

    Spring clips seal housings for electronic circuitry, preventing electromagnetic interference from entering or leaving housings. Clips also keep dust out of housing. Since no bolts are used, housing can be opened quickly; unlike bolts, clips can be used on thin-walled housing. Seal was developed for an X-band array amplifier.

  14. Conical O-ring seal

    DOEpatents

    Chalfant, G.G. Jr.

    A shipping container for radioactive or other hazardous materials has a conical-shaped closure containing grooves in the conical surface thereof and an O-ring seal incorporated in each of such grooves. The closure and seal provide a much stronger, tighter and compact containment than with a conventional flanged joint.

  15. Seals. Grades 3-6.

    ERIC Educational Resources Information Center

    New England Aquarium, Boston, MA.

    Explanations of a marine mammal rescue program and information on seals and sea lions are presented in this curriculum package for intermediate grade teachers. Activities are highlighted which focus on the natural history of harbor seals. This unit contains: (1) pre-trip activities (including fact sheets and worksheets on the different types of…

  16. Refractory Glass Seals for SOFC

    SciTech Connect

    Chou, Y. S.; Stevenson, Jeffry W.

    2011-07-01

    One of the critical challenges facing planar solid oxide fuel cell (SOFC) technology is the need for reliable sealing technology. Seals must exhibit long-term stability and mechanical integrity in the high temperature SOFC environment during normal and transient operation. Several different approaches for sealing SOFC stacks are under development, including glass or glass-ceramic seals, metallic brazes, and compressive seals. Among glass seals, rigid glass-ceramics, self-healing glass, and composite glass approaches have been investigated under the SECA Core Technology Program. The U.S. Department of Energy's Pacific Northwest National Laboratory (PNNL) has developed the refractory glass approach in light of the fact that higher sealing temperatures (e.g., 930-1000 degrees C) may enhance the ultimate in-service bulk strength and electrical conductivity of contact materials, as well as the bonding strength between contact materials and adjacent SOFC components, such as interconnect coatings and electrodes. This report summarizes the thermal, chemical, mechanical, and electrical properties of the refractory sealing glass.

  17. Repository Closure and Sealing Approach

    SciTech Connect

    A.T. Watkins

    2000-06-28

    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&O 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.

  18. Airfoil seal system for gas turbine engine

    SciTech Connect

    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.

  19. Experimental Trichinella infection in seals.

    PubMed

    Kapel, C M O; Measures, L; Møller, L N; Forbes, L; Gajadhar, A

    2003-11-01

    The susceptibility of seals to infection with Trichinella nativa and the cold tolerant characteristics of muscle larvae in seal meat were evaluated. Two grey seals, Halichoerus grypus, were inoculated with 5000 (100 larvae/kg) T. nativa larvae and two grey seals with 50000 (1000 larvae/kg). One seal from each dose group and two control seals were killed at 5 and 10 weeks post-inoculation (p.i.). At 5 weeks p.i., infection was established in both low and high dose seals with mean larval densities of 68 and 472 larvae per gram (lpg), respectively, using eight different muscles for analyses. At 10 weeks p.i., mean larval densities were 531 and 2649 lpg, respectively, suggesting an extended persistence of intestinal worms. In seals with high larval density infections, the distribution of larvae in various muscles was uniform, but in one seal with a low larval density infection, predilection sites of larvae included muscle groups with a relative high blood flow, i.e. diaphragm, intercostal and rear flipper muscles. Trichinella-specific antibody levels, as measured by ELISA, increased during the 10 week experimental period. Infected seal muscle was stored at 5, -5 and -18 degrees C for 1, 4 and 8 weeks. Muscle larvae released from stored seal muscle by artificial digestion were inoculated into mice to assess viability and infectivity. Larvae from seal muscle 10 weeks p.i. tolerated -18 degrees C for 8 weeks but larvae from seal muscle 5 weeks p.i. tolerated only 1 week at -18 degrees C, supporting the hypothesis that freeze tolerance increases with the age of the host-parasite tissue complex. The expressed susceptibility to infection, extended production of larvae, antibody response and freeze tolerance of T. nativa in seals are new findings from the first experimental Trichinella infection in any marine mammal and suggest that pinnipeds (phocids, otariiids or walrus) may acquire Trichinella infection by scavenging even small amounts of infected tissue left by hunters or

  20. Metal seal for wellhead apparatus

    SciTech Connect

    Boecker, R.A.

    1987-03-03

    A method is described of effecting a fluid-tight seal between a surface of an oil and/or gas well tubing or casing and a wellhead member, wherein the surface has been unprepared to form the seal, comprising the steps of: positioning the wellhead member circumferentially about a stub of the tubing or casing; positioning a metal-to-metal fluid-tight sealing means of the wellhead member adjacent the unprepared surface of the tubing or casing, the sealing means having at least one metallic projection positioned to extend toward the unprepared surface of the tubing or casing; and forcing the metallic projection into and penetrating the unprepared surface of the tubing or casing to form a seal therebetween.

  1. Sealed head access area enclosure

    DOEpatents

    Golden, Martin P.; Govi, Aldo R.

    1978-01-01

    A liquid-metal-cooled fast breeder power reactor is provided with a sealed head access area enclosure disposed above the reactor vessel head consisting of a plurality of prefabricated structural panels including a center panel removably sealed into position with inflatable seals, and outer panels sealed into position with semipermanent sealant joints. The sealant joints are located in the joint between the edge of the panels and the reactor containment structure and include from bottom to top an inverted U-shaped strip, a lower layer of a room temperature vulcanizing material, a separator strip defining a test space therewithin, and an upper layer of a room temperature vulcanizing material. The test space is tapped by a normally plugged passage extending to the top of the enclosure for testing the seal or introducing a buffer gas thereinto.

  2. Gas-path seal technology

    NASA Technical Reports Server (NTRS)

    Zuk, J.

    1976-01-01

    Improved gas-path seals are needed for better fuel economy, longer performance retention, and lower maintenance, particularly in advanced, high-performance gas turbine engines. Problems encountered in gas-path sealing are described, as well as new blade-tip sealing approaches for high-pressure compressors and turbines. These include a lubricant coating for conventional, porous-metal, rub-strip materials used in compressors. An improved hot-press metal alloy shows promise to increase the operating surface temperatures of high-pressure-turbine, blade-tip seals to 1450 K (2150 F). Three ceramic seal materials are also described that have the potential to allow much higher gas-path surface operating temperatures than are possible with metal systems.

  3. Aerodynamic seals for rotary machine

    DOEpatents

    Bidkar, Rahul Anil; Cirri, Massimiliano; Thatte, Azam Mihir; Williams, John Robert

    2016-02-09

    An aerodynamic seal assembly for a rotary machine 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 multiple labyrinth teeth therebetween facing the rotor. The sealing device segment also includes multiple flexures connected to the shoe plate and to a top interface element, wherein the multiple flexures are configured to allow the high pressure fluid to occupy a forward cavity and the low pressure fluid to occupy an aft cavity. Further, the sealing device segments include a secondary seal attached to the top interface element at one first end and positioned about the flexures and the shoe plate at one second end.

  4. SEALING MEANS FOR RELATIVELY ROTATABLE MEMBERS

    DOEpatents

    Skarstrom, C.S.

    1960-10-25

    A sealing means is offered for maintaining a seal between a pair of relatively rotatable members, panticularly between a rotating shaft and a stationary member surrounding the shaft. The sealing is accomplished by means of a flange extending outward radially on each of a plurality of sealing rings mounted on the rotating member which fit into annular grooves in the stationary member and are held in sealing relation therewith by means of spring rings. In addition, means are provided for passing a sealing gas through the seal sunfaces to prevent accumulation of lubricant and for scavenging any gas which may have leaked from the internal member into the seal area.

  5. High pressure mechanical seal

    NASA Technical Reports Server (NTRS)

    Babel, Henry W. (Inventor); Anderson, Raymond H. (Inventor)

    1996-01-01

    A relatively impervious mechanical seal is formed between the outer surface of a tube and the inside surface of a mechanical fitting of a high pressure fluid or hydraulic system by applying a very thin soft metal layer onto the outer surface of the hard metal tube and/or inner surface of the hard metal fitting. The thickness of such thin metal layer is independent of the size of the tube and/or fittings. Many metals and alloys of those metals exhibit the requisite softness, including silver, gold, tin, platinum, indium, rhodium and cadmium. Suitably, the coating is about 0.0025 millimeters (0.10 mils) in thickness. After compression, the tube and fitting combination exhibits very low leak rates on the order or 10.sup.-8 cubic centimeters per second or less as measured using the Helium leak test.

  6. High pressure mechanical seal

    NASA Technical Reports Server (NTRS)

    Babel, Henry W. (Inventor); Fuson, Phillip L. (Inventor); Chickles, Colin D. (Inventor); Jones, Cherie A. (Inventor); Anderson, Raymond H. (Inventor)

    1995-01-01

    A relatively impervious mechanical seal is formed between the outer surface of a tube and the inside surface of a mechanical fitting of a high pressure fluid or hydraulic system by applying a very thin soft metal layer onto the outer surface of the hard metal tube and/or inner surface of the hard metal fitting, prior to swaging the fitting onto the tube. The thickness of such thin metal layer is independent of the size of the tube and/or fittings. Many metals and alloys of those metals exhibit the requisite softness, including silver, gold, nickel, tin, platinum, indium, rhodium and cadmium. Suitably, the coating is about 0.0025 millimeters (0.10 mils) in thickness. After swaging, the tube and fitting combination exhibits very low leak rates on the order or 10.sup.-8 cubic centimeters per second or less as meaured using the Helium leak test.

  7. Tamper tape seals

    SciTech Connect

    Wright, B.W.; Undem, H.A.

    1994-07-01

    Tamper tapes are appealing for many applications due to their ease of use and relative robustness. Applications include seals for temporary area denial, protection of sensitive equipment, chain-of-custody audit trails, and inventory control practices. A next generation of adhesive tamper tapes is being developed that combines the best features of commercially available devices with additional state-of-the-art features in tamper indication, tamper-resistance, and counterfeit-resistance. The additional features are based on U.S. Department of Energy (DOE) research and development (R&D) activities that were originally associated with preparations for the Strategic Arms Reduction Treaty (START). New features include rapid-set, chemical-cure adhesive systems that allow user-friendly application and layered levels of counterfeit-resistance based on unique {open_quotes}fingerprint{close_quotes} characteristics that can be accessed as desired.

  8. Do crabeater seals forage cooperatively?

    NASA Astrophysics Data System (ADS)

    Gales, Nicholas J.; Fraser, William R.; Costa, Daniel P.; Southwell, Colin

    2004-08-01

    Crabeater seals are abundant pack-ice predators that feed almost exclusively on krill. They have a circumpolar distribution and are generally sighted hauled out on ice floes alone or in pairs. Here we report our observations of a sighting of 150-200 crabeater seals, which were synchronised in their diving and surfacing behaviour, along with a summary of similar observations from western Antarctica of large groups of crabeater seals in synchronous dive cycles. We report on the low frequency of sightings of such groups during Antarctic pack-ice seal surveys in eastern (Greater) Antarctica. We examine plausible hypotheses to explain these observations, and suggest this behaviour is likely to represent some form of cooperative foraging behaviour, whereby a net advantage in individual energy intake rates is conferred to each seal. Current research on crabeater seal foraging using satellite-linked dive recorders is unlikely to provide sufficiently fine-scale data to examine this hypothesis. Nor will this approach indicate if a seal is foraging with conspecifics. The use of remote or animal-borne camera systems is more likely to provide an insight into fine-scale foraging tactics, as well as the possible, occasional use of cooperative foraging strategies.

  9. Static pressure seal of earmolds.

    PubMed

    Macrae, J

    1990-01-01

    Four experiments were carried out to investigate the effect on the static pressure seal of earmolds made from currently used impression and earmold materials; the occasional practice of making more than one earmold from an impression; the earmoldmaker buildup of impressions; and the multistage buildup of impressions by the impression taker. Experiment 1 showed that the chance of sealing the ear with earmolds made by the ordinary two-stage technique with only general buildup of the impression was approximately 10 percent and that none of the impression or earmold materials significantly improved the chance of obtaining a seal. Experiment 2 showed that the chance of obtaining a seal with multiple earmolds made from the one impression was zero, or very close to zero. Experiment 3 revealed that the chance of obtaining a seal increased to 55 percent when the earmold was made from an impression which was specially built up by the earmoldmaker. Experiment 4 showed that the chance of sealing the ear with earmolds made from multistage impressions was significantly greater (87.5 percent) than sealing the ear with those made from impressions specially built up by the earmoldmaker.

  10. C-band radar backscatter of sea ice in the Weddell Sea, Antarctica during the austral winter of 1992

    NASA Technical Reports Server (NTRS)

    Hosseinmostafa, R.; Drinkwater, Mark R.; Gogineni, S. P.; Dierking, W.

    1993-01-01

    A C-band ship-based scatterometer was used to measure the backscatter coefficient of sea ice in the Weddell Sea during June and July 1992. These are the first microwave scatterometer data ever to be collected in the Antarctic sea ice cover during the austral winter. The instrument was a frequency-modulated continuous-wave (FM-CW) radar altimeter modified by the University of Kansas Radar Systems and Remote Sensing Laboratory to perform backscatter measurements. Measurements were taken as part of a Jet Propulsion Laboratory experiment aboard the German ice research vessel F.S. Polarstern. Backscatter measurements were performed at incidence angles ranging from 17 to 65 degrees with VV and HV polarization as the Polarstern travelled from east to west across the central Weddell Sea. Backscatter measurements were made of several different types of ice sea including pancake, dark nilas, white nilas, grey, first-year and second-year ice. Periodic external calibrations were performed with the aid of a Luneberg Lens to enable absolute values of backscatter to be derived from the data. At each radar measurement location, in-situ measurements were made of snow and sea ice. Physical and chemical analyses of ice core and snow samples, together with high magnification photography of snow crystallography provide important information with which to develop physical models of the scattering systems. Meteorological information and oceanographic conditions were also recorded throughout the experiment. Many of the stations were chosen to coincide with periods of near-simultaneous or coincident imaging by the ERS-1 satellite Synthetic Aperture Radar (SAR). This enabled spaceborne imaging by the C-band SAR of areas of sea ice in which backscatter measurements were taken. This provides a valuable tool for interpretation of satellite SAR imagery from Antarctic sea ice in terms of the physical properties of the sea ice and snow. Preliminary results of the backscatter from the various ice

  11. Snow cover and short-term synoptic events drive biogeochemical dynamics in winter Weddell Sea pack ice (AWECS cruise - June to August 2013)

    NASA Astrophysics Data System (ADS)

    Tison, Jean-Louis; Delille, Bruno; Dieckmann, Gherard; de Jong, Jeroen; Janssens, Julie; Rintala, Janne; Luhtanen, Annemari; Gussone, Niklaus; Uhlig, Christiane; Nomura, Daïki; Schoemann, Véronique; Zhou, Jiayun; Carnat, Gauthier; Fripiat, François

    2014-05-01

    This paper presents the preliminary results of an integrated multidisciplinary study of pack ice biogeochemistry in the Weddell Sea during the winter 2013 (June-August). The sea ice biogeochemistry group was one of the components of the AWECS (Antarctic Winter Ecosystem and Climate Study) cruise (Polarstern ANTXXIX-6). A total of 12 stations were carried out by the sea ice biogeochemistry group, which collected a suite of variables in the fields of physics, inorganic chemistry, gas content and composition, microbiology, biogeochemistry, trace metals and the carbonate system in order to give the best possible description of the sea ice cover and its interactions at interfaces. Samples were collected in the atmosphere above (gas fluxes), in the snow cover, in the bulk ice (ice cores), in the brines (sackholes) and in the sea water below (0m, 1m, 30 m). Here we present the results of basic physico-chemical (T° , bulk ice salinity, brine volumes, brine salinity, Rayleigh numbers) and biological (Chla) measurements in order to give an overview of the general status of the Weddell Sea winter pack ice encountered, and discuss how it controls climate relevant biogeochemical processes. Our results from the first set of 9 stations, mainly sampled along the Greenwich meridian and the easternmost part of the Weddell Sea definitively refute the view of a biogeochemically 'frozen' sea ice during the Winter. This has already been demonstrated for the Spring and Summer, but we now see that sea ice sustains considerable biological stocks and activities throughout the Winter, despite the reduced amount of available PAR radiation. Accretion of the snow cover appears to play an essential role in driving biogeochemical activity, through warming from insulation, thus favouring brine transport, be it through potential convection, surface brine migration (brine tubes) or flooding. This results in a 'widening' of the internal autumn layer (quite frequent in this rafting-dominated sea ice

  12. Bearing-Cartridge Damping Seal

    NASA Technical Reports Server (NTRS)

    Goggins, David G.; Scharrer, Joseph K.; Chen, Wei C.

    1991-01-01

    In proposed design for improved ball-bearing cartridge, damping seal in form of thin-layer fluid journal bearing incorporated into cartridge. Damping seal acts as auxiliary bearing, relieving bearing balls of significant portions of both static and dynamic bearing loads. Damping from seal reduces dynamic loads even further by reducing amplitude of vibrations in second vibrational mode of rotor, which mode occurs when rotor turning at nearly full operating speed. Intended for use in high-pressure-oxygen turbopump of Space Shuttle main engine, also applicable to other turbomachinery bearings.

  13. Studying the Heat Shield's Seal

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This image from NASA's Mars Exploration Rover Opportunity highlights the seal on the rover's protective heat shield. Engineers evaluated the performance of the protective shell's seal during a 36-sol investigation.

    After viewing these images, engineers were pleased with how the seal performed.

    This is an approximately true-color rendering of the scene acquired around 1:07 p.m. local solar time on Opportunity's sol 339 (Jan. 6, 2005) in an image mosaic using panoramic camera filters at wavelengths of 750, 530, and 430 nanometers.

  14. Organochlorine contaminants in endangered Hawaiian monk seals from four subpopulations in the Northwestern Hawaiian Islands.

    PubMed

    Ylitalo, Gina M; Myers, Matthew; Stewart, Brent S; Yochem, Pamela K; Braun, Robert; Kashinsky, Lizabeth; Boyd, Daryle; Antonelis, George A; Atkinson, Shannon; Aguirre, A Alonso; Krahn, Margaret M

    2008-02-01

    We analyzed blubber and blood samples for organochlorines (OCs) from 158 Hawaiian monk seals (Monachus schauinslandi) at four of their six primary breeding colonies in the Northwestern Hawaiian Islands. Levels of OCs in blubber were lower in adult females compared to juveniles or adult males, evidently owing to the transfer of these lipophilic compounds to pups by pregnant and lactating females. Concentrations of SigmaPCBs and p,p'-DDE in blubber generally increased with age until seals were sexually mature and then continued to increase with age in males after puberty. Average levels of PCBs and PCB toxic equivalents (TEQs) in blubber were significantly higher in adult male and juvenile seals at Midway Atoll than the same age class of seals at the other colonies. Unlike concentrations of OCs in blubber, circulating levels of OCs in blood did not vary consistently among age classes of seals or among breeding colonies. Though the concentrations of OCs measured in Hawaiian monk seals were generally equal to or lower than those reported for other pinniped species in the North Pacific Ocean, they were high enough in a few seals to potentially affect their health.

  15. 7 CFR 29.35 - Lot seal.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Lot seal. 29.35 Section 29.35 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.35 Lot seal. A seal approved by the Director for sealing lots...

  16. 36 CFR 901.6 - Seal.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Seal. 901.6 Section 901.6... CORPORATION § 901.6 Seal. The Corporation may adopt a corporate seal which shall have the name of the Corporation and year of incorporation printed upon it. The seal may be used by causing it or a...

  17. 14 CFR 65.133 - Seal.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Seal. 65.133 Section 65.133 Aeronautics and...: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Parachute Riggers § 65.133 Seal. Each certificated parachute rigger must have a seal with an identifying mark prescribed by the Administrator, and a seal press....

  18. 9 CFR 381.98 - Official seal.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Official seal. 381.98 Section 381.98... Certificates; Certification Procedures § 381.98 Official seal. The official mark for use in sealing means of... and a serial number as shown below, and any seals approved by the Administrator for applying such...

  19. 30 CFR 75.339 - Seals records.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Seals records. 75.339 Section 75.339 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.339 Seals records. (a) The table entitled “Seal.... Table—§ 75.339(a) Seal Recordkeeping Requirements Record Section reference Retention time (1)...

  20. 14 CFR 65.133 - Seal.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Seal. 65.133 Section 65.133 Aeronautics and...: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Parachute Riggers § 65.133 Seal. Each certificated parachute rigger must have a seal with an identifying mark prescribed by the Administrator, and a seal press....

  1. 7 CFR 29.34 - Sample seal.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Sample seal. 29.34 Section 29.34 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.34 Sample seal. A seal approved by the Director for sealing...

  2. 36 CFR 901.6 - Seal.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Seal. 901.6 Section 901.6... CORPORATION § 901.6 Seal. The Corporation may adopt a corporate seal which shall have the name of the Corporation and year of incorporation printed upon it. The seal may be used by causing it or a...

  3. 14 CFR 65.133 - Seal.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Seal. 65.133 Section 65.133 Aeronautics and...: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Parachute Riggers § 65.133 Seal. Each certificated parachute rigger must have a seal with an identifying mark prescribed by the Administrator, and a seal press....

  4. 46 CFR 501.11 - Official seal.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 9 2011-10-01 2011-10-01 false Official seal. 501.11 Section 501.11 Shipping FEDERAL... Seal § 501.11 Official seal. (a) Description. Pursuant to section 201(c) of the Merchant Marine Act, 1936, as amended (46 U.S.C. 301(d)), the Commission prescribes its official seal, as adopted by...

  5. 7 CFR 29.35 - Lot seal.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Lot seal. 29.35 Section 29.35 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.35 Lot seal. A seal approved by the Director for sealing lots...

  6. 9 CFR 381.98 - Official seal.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Official seal. 381.98 Section 381.98... Certificates; Certification Procedures § 381.98 Official seal. The official mark for use in sealing means of... and a serial number as shown below, and any seals approved by the Administrator for applying such...

  7. 19 CFR 101.7 - Customs seal.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Customs seal. 101.7 Section 101.7 Customs Duties U... GENERAL PROVISIONS § 101.7 Customs seal. (a) Design. According to the design furnished by the Department of the Treasury, the Customs seal of the United States shall consist of the seal of the Department...

  8. 7 CFR 29.34 - Sample seal.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Sample seal. 29.34 Section 29.34 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.34 Sample seal. A seal approved by the Director for sealing...

  9. 46 CFR 501.11 - Official seal.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 9 2014-10-01 2014-10-01 false Official seal. 501.11 Section 501.11 Shipping FEDERAL... Seal § 501.11 Official seal. (a) Description. Pursuant to section 201(c) of the Merchant Marine Act, 1936, as amended (46 U.S.C. 301(d)), the Commission prescribes its official seal, as adopted by...

  10. 30 CFR 75.339 - Seals records.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Seals records. 75.339 Section 75.339 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.339 Seals records. (a) The table entitled “Seal.... Table—§ 75.339(a) Seal Recordkeeping Requirements Record Section reference Retention time (1)...

  11. 30 CFR 75.339 - Seals records.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Seals records. 75.339 Section 75.339 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.339 Seals records. (a) The table entitled “Seal.... Table—§ 75.339(a) Seal Recordkeeping Requirements Record Section reference Retention time (1)...

  12. 46 CFR 501.11 - Official seal.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 9 2013-10-01 2013-10-01 false Official seal. 501.11 Section 501.11 Shipping FEDERAL... Seal § 501.11 Official seal. (a) Description. Pursuant to section 201(c) of the Merchant Marine Act, 1936, as amended (46 U.S.C. 301(d)), the Commission prescribes its official seal, as adopted by...

  13. 9 CFR 381.98 - Official seal.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Official seal. 381.98 Section 381.98... Certificates; Certification Procedures § 381.98 Official seal. The official mark for use in sealing means of... and a serial number as shown below, and any seals approved by the Administrator for applying such...

  14. 46 CFR 501.11 - Official seal.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 9 2012-10-01 2012-10-01 false Official seal. 501.11 Section 501.11 Shipping FEDERAL... Seal § 501.11 Official seal. (a) Description. Pursuant to section 201(c) of the Merchant Marine Act, 1936, as amended (46 U.S.C. 301(d)), the Commission prescribes its official seal, as adopted by...

  15. 14 CFR 65.133 - Seal.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Seal. 65.133 Section 65.133 Aeronautics and...: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Parachute Riggers § 65.133 Seal. Each certificated parachute rigger must have a seal with an identifying mark prescribed by the Administrator, and a seal press....

  16. 19 CFR 101.7 - Customs seal.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Customs seal. 101.7 Section 101.7 Customs Duties U... GENERAL PROVISIONS § 101.7 Customs seal. (a) Design. According to the design furnished by the Department of the Treasury, the Customs seal of the United States shall consist of the seal of the Department...

  17. 7 CFR 29.35 - Lot seal.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Lot seal. 29.35 Section 29.35 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.35 Lot seal. A seal approved by the Director for sealing lots...

  18. 30 CFR 75.339 - Seals records.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Seals records. 75.339 Section 75.339 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.339 Seals records. (a) The table entitled “Seal.... Table—§ 75.339(a) Seal Recordkeeping Requirements Record Section reference Retention time (1)...

  19. 36 CFR 901.6 - Seal.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Seal. 901.6 Section 901.6... CORPORATION § 901.6 Seal. The Corporation may adopt a corporate seal which shall have the name of the Corporation and year of incorporation printed upon it. The seal may be used by causing it or a...

  20. 30 CFR 75.339 - Seals records.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Seals records. 75.339 Section 75.339 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.339 Seals records. (a) The table entitled “Seal.... Table—§ 75.339(a) Seal Recordkeeping Requirements Record Section reference Retention time (1)...

  1. 19 CFR 101.7 - Customs seal.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Customs seal. 101.7 Section 101.7 Customs Duties U... GENERAL PROVISIONS § 101.7 Customs seal. (a) Design. According to the design furnished by the Department of the Treasury, the Customs seal of the United States shall consist of the seal of the Department...

  2. 36 CFR 901.6 - Seal.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Seal. 901.6 Section 901.6... CORPORATION § 901.6 Seal. The Corporation may adopt a corporate seal which shall have the name of the Corporation and year of incorporation printed upon it. The seal may be used by causing it or a...

  3. 7 CFR 29.34 - Sample seal.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Sample seal. 29.34 Section 29.34 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.34 Sample seal. A seal approved by the Director for sealing...

  4. 9 CFR 381.98 - Official seal.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Official seal. 381.98 Section 381.98... Certificates; Certification Procedures § 381.98 Official seal. The official mark for use in sealing means of... and a serial number as shown below, and any seals approved by the Administrator for applying such...

  5. 7 CFR 29.34 - Sample seal.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Sample seal. 29.34 Section 29.34 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.34 Sample seal. A seal approved by the Director for sealing...

  6. 19 CFR 101.7 - Customs seal.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Customs seal. 101.7 Section 101.7 Customs Duties U... GENERAL PROVISIONS § 101.7 Customs seal. (a) Design. According to the design furnished by the Department of the Treasury, the Customs seal of the United States shall consist of the seal of the Department...

  7. 46 CFR 501.11 - Official seal.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 9 2010-10-01 2010-10-01 false Official seal. 501.11 Section 501.11 Shipping FEDERAL... Seal § 501.11 Official seal. (a) Description. Pursuant to section 201(c) of the Merchant Marine Act, 1936, as amended (46 U.S.C. 301(d)), the Commission prescribes its official seal, as adopted by...

  8. 9 CFR 381.98 - Official seal.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Official seal. 381.98 Section 381.98... Certificates; Certification Procedures § 381.98 Official seal. The official mark for use in sealing means of... and a serial number as shown below, and any seals approved by the Administrator for applying such...

  9. 14 CFR 65.133 - Seal.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Seal. 65.133 Section 65.133 Aeronautics and...: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Parachute Riggers § 65.133 Seal. Each certificated parachute rigger must have a seal with an identifying mark prescribed by the Administrator, and a seal press....

  10. 7 CFR 29.35 - Lot seal.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Lot seal. 29.35 Section 29.35 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.35 Lot seal. A seal approved by the Director for sealing lots...

  11. 36 CFR 901.6 - Seal.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Seal. 901.6 Section 901.6... CORPORATION § 901.6 Seal. The Corporation may adopt a corporate seal which shall have the name of the Corporation and year of incorporation printed upon it. The seal may be used by causing it or a...

  12. Overview of Turbine Seal Testing at GRC

    NASA Technical Reports Server (NTRS)

    Proctor, Margaret P.; Delgado, Irebert R.

    2006-01-01

    Objectives: 1) Evaluate feasibility of advanced seal concepts and materials of meeting next generation engine speed and temperature requirements; 2) Provide a state-of-the-art turbomachinery seal test rig capable of testing seals under known and anticipated design conditions; and 3) Work with industry to assess and demonstrate performance of their seals prior to test in engine.

  13. Seal device for ferromagnetic containers

    DOEpatents

    Meyer, Ross E.; Jason, Andrew J.

    1994-01-01

    A temporary seal or patch assembly prevents the escape of contents, e.g., fluids and the like, from within a container having a breach therethrough until the contents can be removed and/or a repair effected. A frame that supports a sealing bladder can be positioned over the breach and the frame is then attached to the container surface, which must be of a ferromagnet material, by using switchable permanent magnets. The permanent magnets are designed to have a first condition that is not attracted to the ferromagnetic surface and a second conditions whereby the magnets are attracted to the surface with sufficient force to support the seal assembly on the surface. Latching devices may be attached to the frame and engage the container surface with hardened pins to prevent the lateral movement of the seal assembly along the container surface from external forces such as fluid drag or gravity.

  14. Seal device for ferromagnetic containers

    DOEpatents

    Meyer, R.E.; Jason, A.J.

    1994-10-18

    A temporary seal or patch assembly prevents the escape of contents, e.g., fluids and the like, from within a container having a breach there through until the contents can be removed and/or a repair effected. A frame that supports a sealing bladder can be positioned over the breach and the frame is then attached to the container surface, which must be of a ferromagnet material, by using switchable permanent magnets. The permanent magnets are designed to have a first condition that is not attracted to the ferromagnetic surface and a second conditions whereby the magnets are attracted to the surface with sufficient force to support the seal assembly on the surface. Latching devices may be attached to the frame and engage the container surface with hardened pins to prevent the lateral movement of the seal assembly along the container surface from external forces such as fluid drag or gravity. 10 figs.

  15. Cryogenic Brush Seal Test Results

    NASA Technical Reports Server (NTRS)

    Proctor, Margaret P.; Walker, James F.

    1996-01-01

    Brush seals are compliant, contact seals that have long-life, low-leakage characteristics desirable for use in rocket engine turbopumps. 50.8-mm (2.0 inch) diameter brush seals with a nominal initial radial interference of 0.127-mm (0.005 inch) were tested in liquid nitrogen at shaft speeds up to 35,000 rpm and differential pressure loads up to 1.21 MPa (175 psi) per brush. The measured leakage rate of a single brush was 2-3 times less than that measured for a 12-tooth, 0.127-mm (0.005 inch) radial clearance labyrinth seal used as a baseline. Stage effects were studied and it was found that two brush seals with a large separation distance leaked less than two brushes tightly packed together. The maximum measured groove depth on the Inconel 718 rotor was 25.4 (mu)m (0.001 inch) after 4.31 hours of shaft rotation. The Haynes-25 bristles wore approximately 25.4-76.2 (mu)m (0.001-0.003 inch) under the same conditions. Three seal runner coatings, chromium carbide, Teflon impregnated chromium, and zirconium oxide, were tested in liquid hydrogen at 35,000 and 65,000 rpm with separate 50.8 mm diameter brush seals made of Haynes-25 bristles and having a nominal initial radial interference of 129 rpm. Two bare Inconel-718 rotors were also tested as a baseline. The test results revealed significant differences between the wear characteristics of the uncoated and coated seal runners. At both speeds the brush seal with the bare Inconel-718 seal runner exhibited significant bristle wear with excessive material transferring to the runner surface. In contrast, the coated seal runners inhibited the transfer and deposit of bristle material. The chromium carbide coating showed only small quantities of bristle material transferring to its surface. The Teflon impregnated chromium coating also inhibited material transfer and provided some lubrication. This coating, however, is self-sacrificing. The Teflon remained present on the low speed runner, but it was completely removed from the

  16. Remotely Monitored Sealing Array Software

    SciTech Connect

    2012-09-12

    The Remotely Monitored Sealing Array (RMSA) utilizes the Secure Sensor Platform (SSP) framework to establish the fundamental operating capabilities for communication, security, power management, and cryptography. In addition to the SSP framework the RMSA software has unique capabilities to support monitoring a fiber optic seal. Fiber monitoring includes open and closed as well as parametric monitoring to detect tampering attacks. The fiber monitoring techniques, using the SSP power management processes, allow the seals to last for years while maintaining the security requirements of the monitoring application. The seal is enclosed in a tamper resistant housing with software to support active tamper monitoring. New features include LED notification of fiber closure, the ability to retrieve the entire fiber optic history via translator command, separate memory storage for fiber optic events, and a more robust method for tracking and resending failed messages.

  17. Reactor vessel seal service fixture

    DOEpatents

    Ritz, W.C.

    1975-12-01

    An apparatus for the preparation of exposed sealing surfaces along the open rim of a nuclear reactor vessel comprised of a motorized mechanism for traveling along the rim and simultaneously brushing the exposed surfaces is described.

  18. Seals Research at AlliedSignal

    NASA Technical Reports Server (NTRS)

    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.

  19. Organic iodine in Antarctic sea ice: A comparison between winter in the Weddell Sea and summer in the Amundsen Sea

    NASA Astrophysics Data System (ADS)

    Granfors, Anna; Ahnoff, Martin; Mills, Matthew M.; Abrahamsson, Katarina

    2014-12-01

    Recent studies have recognized sea ice as a source of reactive iodine to the Antarctic boundary layer. Volatile iodinated compounds (iodocarbons) are released from sea ice, and they have been suggested to contribute to the formation of iodine oxide (IO), which takes part in tropospheric ozone destruction in the polar spring. We measured iodocarbons (CH3I, CH2ClI, CH2BrI, and CH2I2) in sea ice, snow, brine, and air during two expeditions to Antarctica, OSO 10/11 to the Amundsen Sea during austral summer and ANT XXIX/6 to the Weddell Sea in austral winter. These are the first reported measurements of iodocarbons from the Antarctic winter. Iodocarbons were enriched in sea ice in relation to seawater in both summer and winter. During summer, the positive relationship to chlorophyll a biomass indicated a biological origin. We suggest that CH3I is formed biotically in sea ice during both summer and winter. For CH2ClI, CH2BrI, and CH2I2, an additional abiotic source at the snow/ice interface in winter is suggested. Elevated air concentrations of CH3I and CH2ClI during winter indicate that they are enriched in lower troposphere and may take part in the formation of IO at polar sunrise.

  20. Reconstructing the Last Glacial Maximum ice sheet in the Weddell Sea embayment, Antarctica, using numerical modelling constrained by field evidence

    NASA Astrophysics Data System (ADS)

    Le Brocq, A. M.; Bentley, M. J.; Hubbard, A.; Fogwill, C. J.; Sugden, D. E.; Whitehouse, P. L.

    2011-09-01

    The Weddell Sea Embayment (WSE) sector of the Antarctic ice sheet has been suggested as a potential source for a period of rapid sea-level rise - Meltwater Pulse 1a, a 20 m rise in ˜500 years. Previous modelling attempts have predicted an extensive grounding line advance in the WSE, to the continental shelf break, leading to a large equivalent sea-level contribution for the sector. A range of recent field evidence suggests that the ice sheet elevation change in the WSE at the Last Glacial Maximum (LGM) is less than previously thought. This paper describes and discusses an ice flow modelling derived reconstruction of the LGM ice sheet in the WSE, constrained by the recent field evidence. The ice flow model reconstructions suggest that an ice sheet consistent with the field evidence does not support grounding line advance to the continental shelf break. A range of modelled ice sheet surfaces are instead produced, with different grounding line locations derived from a novel grounding line advance scheme. The ice sheet reconstructions which best fit the field constraints lead to a range of equivalent eustatic sea-level estimates between approximately 1.4 and 3 m for this sector. This paper describes the modelling procedure in detail, considers the assumptions and limitations associated with the modelling approach, and how the uncertainty may impact on the eustatic sea-level equivalent results for the WSE.

  1. Seasonal variability of water masses and transport on the Antarctic continental shelf and slope in the southeastern Weddell Sea

    NASA Astrophysics Data System (ADS)

    Graham, Jennifer A.; Heywood, Karen J.; Chavanne, Cédric P.; Holland, Paul R.

    2013-04-01

    An array of five moorings was deployed from February 2009 to February 2010 across the Antarctic shelf and slope in the southeastern Weddell Sea (~18°W). Observations demonstrate the key processes responsible for variability in water masses and transport in the region. Rapid fluctuations in temperature and salinity throughout the year are linked with variability in wind stress over the array. This causes the deepening or shoaling of the pycnocline, past the depth of the moorings. In the upper 500 m, the seasonal cycle in salinity shows freshening in autumn, with the strongest freshening at the shallowest mooring (~250 m), furthest on-shelf. The sea ice concentration over the array exceeds 90% during this period and contributes a positive salt flux into the ocean during autumn. Freshening begins during strong along-shore (easterly) winds in late April 2009. This demonstrates that variations in Ekman transport and wind-driven mixing play a key role in determining the salinity of shelf waters around Antarctica. Transport of the Antarctic Slope Current also shows a seasonal cycle with a maximum during late April. Model simulations show the importance of along-shore advection, as the arrival of a fresh anomaly from upstream determines the timing of the salinity minimum at the array. These processes are likely to be important for other regions around the Antarctic continent.

  2. Metal enrichment experiments in the Weddell-Scotia Seas: Effects of iron and manganese on various communities

    SciTech Connect

    Buma, A.G.J.; Barr, H.J.W. de; Nolting, R.F.; Bennekom, A.J. van )

    1991-12-01

    During the European Polarstern Study (EPOS 1988/1989) in the Weddell and Scotia Seas, five series of metal enrichment experiments were carried out with natural plankton communities under ultraclean conditions. Despite a clear stimulation of growth by the addition of Fe, control bottles also showed rapid buildup of Chl a and complete utilization of a major nutrient within 2 weeks, indicating nonlimiting ambient Fe levels. Effects of Mn additions were less pronounced or absent, whereas extra additions of Zn and Cu in one experiment showed little or no effect. The species composition of the plankton community, monitored by HPLC pigment analysis and microscopic observations, changed in favor of diatoms when Fe was added. The addition of Fe also caused an increase in microzooplankton densities and concentrations of pigment breakdown products. However, metal-mediated shifts in the plankton community were minor compared to major changes resulting from incubation. Changes were most pronounced in experiments where microzooplankton was strongly developed, presumably as a result of excluding mesozooplankton from the bottles. Fe had an impact on plankton growth and species composition, but other factors seem to responsible for keeping phytoplankton productivity far from its potential in these Antarctic waters.

  3. Brush Seals for Improved Steam Turbine Performance

    NASA Technical Reports Server (NTRS)

    Turnquist, Norman; Chupp, Ray; Baily, Fred; Burnett, Mark; Rivas, Flor; Bowsher, Aaron; Crudgington, Peter

    2006-01-01

    GE Energy has retrofitted brush seals into more than 19 operating steam turbines. Brush seals offer superior leakage control compared to labyrinth seals, owing to their compliant nature and ability to maintain very tight clearances to the rotating shaft. Seal designs have been established for steam turbines ranging in size from 12 MW to over 1200 MW, including fossil, nuclear, combined-cycle and industrial applications. Steam turbines present unique design challenges that must be addressed to ensure that the potential performance benefits of brush seals are realized. Brush seals can have important effects on the overall turbine system that must be taken into account to assure reliable operation. Subscale rig tests are instrumental to understanding seal behavior under simulated steam-turbine operating conditions, prior to installing brush seals in the field. This presentation discusses the technical challenges of designing brush seals for steam turbines; subscale testing; performance benefits of brush seals; overall system effects; and field applications.

  4. Self Sealing Magmas

    NASA Astrophysics Data System (ADS)

    von Aulock, Felix W.; Wadsworth, Fabian B.; Kennedy, Ben M.; Lavallee, Yan

    2015-04-01

    During ascent of magma, pressure decreases and bubbles form. If the volume increases more rapidly than the relaxation timescale, the magma fragments catastrophically. If a permeable network forms, the magma degasses non-violently. This process is generally assumed to be unidirectional, however, recent studies have shown how shear and compaction can drive self sealing. Here, we additionally constrain skin formation during degassing and sintering. We heated natural samples of obsidian in a dry atmosphere and monitored foaming and impermeable skin formation. We suggest a model for skin formation that is controlled by diffusional loss of water and bubble collapse at free surfaces. We heated synthetic glass beads in a hydrous atmosphere to measure the timescale of viscous sintering. The beads sinter at drastically shorter timescales as water vapour rehydrates an otherwise degassed melt, reducing viscosity and glass transition temperatures. Both processes can produce dense inhomogeneities within the timescales of magma ascent and effectively disturb permeabilities and form barriers, particularly at the margins of the conduit, where strain localisation takes place. Localised ash in failure zones (i.e. Tuffisite) then becomes associated with water vapour fluxes and alow rapid rehydration and sintering. When measuring permeabilities in laboratory and field, and when discussing shallow degassing in volcanoes, local barriers for degassing should be taken into account. Highlighting the processes that lead to the formation of such dense skins and sintered infills of cavities can help understanding the bulk permeabilities of volcanic systems.

  5. Reusable, tamper-indicating seal

    DOEpatents

    Ryan, Michael J.

    1978-01-01

    A reusable, tamper-indicating seal comprises 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 position. A new pattern of colored balls will appear in the segregated location when the seal is relocked.

  6. Probe Insertion Apparatus with Inflatable Seal

    NASA Technical Reports Server (NTRS)

    Trimarchi, Paul A.

    1991-01-01

    A sealing apparatus for inserting a probe into a pressure vessel having an elongated opening includes Ii pair of resiliently defQrmable seals opposingly disposed in sealing engagement with each other. A retainer is connected to the pressure vessel around the elongated opening and holds the pair of seals rigidly to the pressure vessel. A wedge is engageable with the pair of seals and carries the probe, for longitudinally translating the probe in the pressure vessel.

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

    PubMed

    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.

  8. Overview of NASA Glenn Seal Program

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Proctor, Margaret P.; Dunlap, Patrick H., Jr.; Delgado, Irebert; DeMange, Jeffrey J.; Daniels, Christopher C.; Lattime, Scott B.

    2003-01-01

    The Seal Team is divided into four primary areas. These areas include turbine engine seal development, structural seal development, acoustic seal development, and adaptive seal development. The turbine seal area focuses on high temperature, high speed shaft seals for secondary air system flow management. The structural seal area focuses on high temperature, resilient structural seals required to accommodate large structural distortions for both space- and aero-applications. Our goal in the acoustic seal project is to develop non-contacting, low leakage seals exploiting the principles of advanced acoustics. We are currently investigating a new acoustic field known as Resonant Macrosonic Synthesis (RMS) to see if we can harness the large acoustic standing pressure waves to form an effective air-barrier/seal. Our goal in the adaptive seal project is to develop advanced sealing approaches for minimizing blade-tip (shroud) or interstage seal leakage. We are planning on applying either rub-avoidance or regeneration clearance control concepts (including smart structures and materials) to promote higher turbine engine efficiency and longer service lives.

  9. Characteristics of marine debris that entangle Australian fur seals (Arctocephalus pusillus doriferus) in southern Australia.

    PubMed

    Lawson, T J; Wilcox, Chris; Johns, Karen; Dann, P; Hardesty, Britta Denise

    2015-09-15

    Marine debris is a global issue that can have devastating impacts on marine mammals. To understand the types of materials that result in entanglement and thus the potential impact of entangling items on marine wildlife, we analysed data collected from items in which Australian fur seals had been entangled in southern Victoria, Australia over a 15year period. From 1997 to 2012, 138 entangling items were removed from seals. The majority of these entanglements were plastic twine or rope, and seals were entangled in green items more than in any other colour. In general, younger seals were more likely to be entangled than adults. Understanding the effects of marine debris entanglement on the Australian fur seal population can lead to more effective management of the sources of debris and the wildlife that interact with it.

  10. Canister, sealing method and composition for sealing a borehole

    SciTech Connect

    Brown, Donald W.; Wagh, Arun S.

    2003-05-13

    Canister, sealing method and composition for sealing a borehole. The canister includes a container with slurry inside the container, one or more slurry exits at one end of the container, a pump at the other end of the container, and a piston inside that pushes the slurry though the slurry exit(s), out of the container, and into a borehole. An inflatable packer outside the container provides stabilization in the borehole. A borehole sealing material is made by combining an oxide or hydroxide and a phosphate with water to form a slurry which then sets to form a high strength, minimally porous material which binds well to itself, underground formations, steel and ceramics.

  11. Radioactive material package seal tests

    SciTech Connect

    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 {times} 10{sup {minus}7} std cm{sup 3}/s) at manufacturer low-temperature ratings. 8 refs., 3 figs., 1 tab.

  12. Tamper-Indicating Quantum Seal*

    NASA Astrophysics Data System (ADS)

    Williams, Brian P.; Britt, Keith A.; Humble, Travis S.

    2016-01-01

    Technical means for identifying when tampering occurs is a critical part of many containment and surveillance technologies. Conventional fiber-optic seals provide methods for monitoring enclosed inventories, but they are vulnerable to spoofing attacks based on classical physics. We address these vulnerabilities with the development of a quantum seal that offers the ability to detect the intercept-resend attack using quantum integrity verification. Our approach represents an application of entanglement to provide guarantees in the authenticity of the seal state by verifying it is transmitted coherently. We implement these ideas using polarization-entangled photon pairs that are verified after passing through a fiber-optic-channel test bed. Using binary-detection theory, we find the probability of detecting inauthentic signals is greater than 0.9999 with a false-alarm chance of 1 0-9 for a 10-s sampling interval. In addition, we show how the Hong-Ou-Mandel effect concurrently provides a tight bound on redirection attack, in which tampering modifies the shape of the seal. Our measurements limit the tolerable path-length change to submillimeter disturbances. These tamper-indicating features of the quantum seal offer unprecedented security for unattended monitoring systems.

  13. Early results from combined historic chlorofluorocarbon and first sulphur hexafluoride measurements in the Weddell Sea - variability of ventilation rates and anthropogenic carbon

    NASA Astrophysics Data System (ADS)

    Huhn, O.; Rhein, M.; Bulsiewicz, K.

    2012-04-01

    The Weddell Sea is a key area for the formation of deep and bottom water and, hence, a major driver of the deep part of the global ocean's conveyor belt. Furthermore, it provides an important sink for atmospheric gases like anthropogenic carbon. Its sensitivity to changing atmospheric conditions is under discussion. During the last three decades time series of anthropogenic transient tracer measurements (chlorofluorocarbons, CFCs) were obtained on a section crossing the Weddell Basin from the northern tip of the Antarctic Peninsula to Cape Norwegia and along the Prime Meridian from the Antarctic Continent to the Mid Atlantic Ridge (1984-2008). On our most recent RV POLARSTERN expedition from November 2010 to February 2011 we obtained for the first time sulphur hexafluoride (SF6) measurements in addition to CFCs in that area. The onset of the atmospheric SF6 history starts some decades after the CFCs, and the increase of SF6 in the atmosphere is steeper. The combination of CFC and SF6 may, hence, provide a better constraint for the quantification of very recently ventilated deep and bottom water and for the estimate of transport time scales or transit time distributions (TTDs). We discuss that new CFC and SF6 data set in comparison to the historic CFC data and show early results from our analysis. We use the extended CFC time series combined with the additional tracer SF6 to determine TTDs, from which we assess the ventilation rates of deep and bottom water and estimate the related content of anthropogenic carbon and their temporal variability in the Weddell Sea during the last three decades.

  14. Nonelastomeric Rod Seals for Advanced Hydraulic Systems

    NASA Technical Reports Server (NTRS)

    Hady, W. F.; Waterman, A. W.

    1976-01-01

    Advanced high temperature hydraulic system rod sealing requirements can be met by using seals made of nonelastomeric (plastic) materials in applications where elastomers do not have adequate life. Exploratory seal designs were optimized for advanced applications using machinable polyimide materials. These seals demonstrated equivalent flight hour lives of 12,500 at 350 F and 9,875 at 400 F in advanced hydraulic system simulation. Successful operation was also attained under simulated space shuttle applications; 96 reentry thermal cycles and 1,438 hours of vacuum storage. Tests of less expensive molded plastic seals indicated a need for improved materials to provide equivalent performance to the machined seals.

  15. Gas Path Sealing in Turbine Engines

    NASA Technical Reports Server (NTRS)

    Ludwig, L. P.

    1978-01-01

    A survey of gas path seals is presented with particular attention given to sealing clearance effects on engine component efficiency. The effects on compressor pressure ratio and stall margin are pointed out. Various case-rotor relative displacements, which affect gas path seal clearances, are identified. Forces produced by nonuniform sealing clearances and their effect on rotor stability are discussed qualitatively, and recent work on turbine-blade-tip sealing for high temperature is described. The need for active clearance control and for engine structural analysis is discussed. The functions of the internal-flow system and its seals are reviewed.

  16. Monolithic LTCC seal frame and lid

    SciTech Connect

    Krueger, Daniel S.; Peterson, Kenneth A.; Stockdale, Dave; Duncan, James Brent; Riggs, Bristen

    2016-06-21

    A method for forming a monolithic seal frame and lid for use with a substrate and electronic circuitry comprises the steps of forming a mandrel from a ceramic and glass based material, forming a seal frame and lid block from a ceramic and glass based material, creating a seal frame and lid by forming a compartment and a plurality of sidewalls in the seal frame and lid block, placing the seal frame and lid on the mandrel such that the mandrel fits within the compartment, and cofiring the seal frame and lid block.

  17. Actively controlled shaft seals for aerospace applications

    NASA Technical Reports Server (NTRS)

    Salant, Richard F.

    1991-01-01

    Actively controlled mechanical seals have recently been developed for industrial use. This study investigates the feasibility of using such seals for aerospace applications. In a noncontacting mechanical seal, the film thickness depends on the geometry of the seal interface. The amount of coning, which is a measure of the radial convergence or divergence of the seal interface, has a primary effect on the film thickness. Active control of the film thickness is established by controlling the coning with a piezoelectric material. A mathematical model has been formulated to predict the performance of an actively controlled mechanical seal.

  18. Labyrinth seal testing for lift fan engines

    NASA Technical Reports Server (NTRS)

    Dobek, L. J.

    1973-01-01

    An abradable buffered labyrinth seal for the control of turbine gas path leakage in a tip-turbine driven lift fan was designed, tested, and analyzed. The seal configuration was not designed to operate in any specific location but was sized to be evaluated in an existing test rig. The final sealing diameter selected was 28 inches. Results of testing indicate that the flow equations predicted seal air flows consistent with measured values. Excellent sealing characteristics of the abradable coating on the stator land were demonstrated when a substantial seal penetration of .030 inch into the land surface was encountered without appreciable wear on the labyrinth knife edges.

  19. Stable isotopes confirm a coastal diet for critically endangered Mediterranean monk seals.

    PubMed

    Karamanlidis, Alexandros A; Curtis, P Jeff; Hirons, Amy C; Psaradellis, Marianna; Dendrinos, Panagiotis; Hopkins, John B

    2014-01-01

    Understanding the ecology and behaviour of endangered species is essential for developing effective management and conservation strategies. We used stable isotope analysis to investigate the foraging behaviour of critically endangered Mediterranean monk seals (Monachus monachus) in Greece. We measured carbon and nitrogen isotope ratios (expressed as δ(13)C and δ(15)N values, respectively) derived from the hair of deceased adult and juvenile seals and the muscle of their known prey to quantify their diets. We tested the hypothesis that monk seals primarily foraged for prey that occupy coastal habitats in Greece. We compared isotope values from seal hair to their coastal and pelagic prey (after correcting all prey for isotopic discrimination) and used these isotopic data and a stable isotope mixing model to estimate the proportion of coastal and pelagic resources consumed by seals. As predicted, we found that seals had similar δ(13)C values as many coastal prey species and higher δ(13)C values than pelagic species; these results, in conjunction with mean dietary estimates (coastal=61 % vs. pelagic=39 %), suggest that seals have a diverse diet comprising prey from multiple trophic levels that primarily occupy the coast. Marine resource managers should consider using the results from this study to inform the future management of coastal habitats in Greece to protect Mediterranean monk seals.

  20. Chemical processes in the atmosphere-snow-sea ice over the Weddell Sea, Antarctica during winter and spring

    NASA Astrophysics Data System (ADS)

    Jacobi, Hans-Werner; Jourdain, Bruno; Dommergue, Aurelien; Nerentorp Mastromonaco, Michelle; Gardfeldt, Katarina; Abrahamsson, Katarina; Granfors, Anna; Ahnhoff, Martin; Frey, Markus M.; Méjean, Guillaume; Friess, Udo; Nasse, Jan-Marcus

    2016-04-01

    Wintertime chemical processes in the atmosphere-snow-sea ice system of Antarctica are almost unknown because of a lack of in situ observations. During two cruises with the German research icebreaker R/V Polarstern we had the opportunity to perform measurements over and in the sea ice of the Weddell Sea from June to October 2013 covering the transition from winter to spring in the Southern Hemisphere. We performed atmospheric measurements of ozone, mercury, and reactive mercury compounds linked due to so-called ozone and mercury depletion events (ODEs and AMDEs), during which the two normally ubiquitous compounds ozone and mercury are efficiently removed from the atmosphere. Moreover, reactive halogenated compounds as the major cause of these depletion events were also observed in the atmosphere using remote sensing as well as in situ techniques. The observations demonstrated that the formation of reactive halogen compounds as well as depletions of ozone and mercury occurred as early as July potentially caused by a dark halogen activation mechanism. The activation of halogens further left their imprint also in the chemical composition of the snow on top of the sea ice, which showed occasionally a reduction in bromide. Elevated concentrations of halogenated compounds in the sea ice well above levels normally observed during the summer season indicate that active halogen chemistry was not limited to the atmosphere, but impacted the entire atmosphere-snow-sea ice system. Finally, aerosol measurements confirmed that the snow on sea ice constitutes an important surface for the mobilization and generation of atmospheric sea salt aerosol. As a result, sea salt aerosol significantly increased during and after blowing snow events, providing a potentially significant reservoir of atmospheric reactive halogens.

  1. Austral spring microalgae across the Weddell Sea ice edge: spatial relationships found along a northward transect during AMERIEZ 83

    NASA Astrophysics Data System (ADS)

    Fryxell, Greta A.; Kendrick, Gary A.

    1988-01-01

    In the northwestern Weddell Sea and eastern Scotia Sea on a transect north from ice-covered, through ice-melt, to open-ocean stations, microalgae were compared to document an enhanced biological activity expected near the ice edge. The highest numbers of cells were found in open water, with 68.7 × 10 9 cells m -2 north of the ice edge, although melted ice cores and brine from pore water samples averaged more than an order of magnitude more cells per liter. The dominant taxa under the ice and in the ice-melt stations were the pennate diatom genus Nitzschia and the prymeesiophyte Phaeocystis. In the open ocean, the dominants were the centric diatom Thalassiosira gravida and Phaeocystis; both grew in gelatinous colonies, a growth habit that apparently gave competitive advantage and may have inhibited grazing. Phaeocystis could have been seeded from the melting ice and from the water under the ice; it seems less likely that T. gravida came only from those sources. Although Phaeocystis cells were frequently dominant in number, the genus represented far less carbon than T gravida in open waters; Phaeocystis presents a taxonomic and ecological enigma in comparison with accounts from the northern hemisphere in that it was abundant where diatoms also fluorished. Nitzschia survived in low light under the ice and in the brine pockets in the ice and increased steadily in abundance at the ice edge in the open water, whereas Thalassiosira was most abundant to the north and west where the water had recently been uncovered by the retreating ice edge. Of the three dominant taxa, Nitzschia appears to provide the best food base for the zooplankton such as krill.

  2. Cryogenic Flange and Seal Evaluation

    NASA Technical Reports Server (NTRS)

    Ramirez, Adrian

    2014-01-01

    The assembly of flanges, seals, and pipes are used to carry cryogenic fluid from a storage tank to the vehicle at launch sites. However, after a certain amount of cycles these raised face flanges with glass-filled Teflon gaskets have been found to have torque relaxation and are as a result susceptible to cryogenic fluid leakage if not re-torqued. The intent of this project is to identify alternate combinations of flanges and seals which may improve thermal cycle performance and decrease re-torque requirements. The general approach is to design a test fixture to evaluate leak characteristics between spiral and concentric serrations and to test alternate flange and seal combinations. Due to insufficient time, it was not possible to evaluate these different types of combinations for the combination that improved thermal cycle performance the most. However, the necessary drawings for the test fixture were designed and assembled along with the collection of the necessary parts.

  3. Laser sealed vacuum insulation window

    DOEpatents

    Benson, David K.; Tracy, C. Edwin

    1987-01-01

    A laser sealed evacuated window panel is comprised of two glass panes held spaced apart in relation to each other by a plurality of spherical glass beads and glass welded around the edges to provide an evacuated space between the glass panes that is completely glass sealed from the exterior. The glass welded edge seal is obtained by welding the edges of the glass panes together with a laser beam while the glass panes and bead spacers are positioned in a vacuum furnace and heated to the annealing point of the glass to avoid stress fracture in the area of the glass weld. The laser welding in the furnace can be directed around the perimeter of the glass panel by a combination of rotating the glass panel and linearly translating or aiming the laser with a relay mirror.

  4. Mechanical seal with textured sidewall

    DOEpatents

    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.

  5. Energy conservation through sealing technology

    NASA Technical Reports Server (NTRS)

    Stair, W. K.; Ludwig, L. P.

    1978-01-01

    Improvements in fluid film sealing resulting from a proposed research program could lead to an annual energy saving, on a national basis, equivalent to about 37 million bbl of oil or 0.3% of the total U.S. energy consumption. Further, the application of known sealing technology can result in an annual saving of an additional 10 million bbl of oil. The energy saving would be accomplished by reduction in process heat energy loss, reduction of frictional energy generated, and minimization of energy required to operate ancillary equipment associated with the seal system. In addition to energy saving, cost effectiveness is further enhanced by reduction in maintenance and in minimization of equipment for collecting leakage and for meeting environmental pollution standards.

  6. Laser sealed vacuum insulating window

    DOEpatents

    Benson, D.K.; Tracy, C.E.

    1985-08-19

    A laser sealed evacuated window panel is comprised of two glass panes held spaced apart in relation to each other by a plurality of spherical glass beads and glass welded around the edges to provide an evacuated space between the glass panes that is completely glass sealed from the exterior. The glass welded edge seal is obtained by welding the edges of the glass panes together with a laser beam while the glass panes and bead spacers are positioned in a vacuum furnace and heated to the annealing point of the glass to avoid stress fracture in the area of the glass weld. The laser welding in the furnace can be directed around the perimeter of the galss panel by a combination of rotating the glass panel and linearly translating or aiming the laser with a relay mirror.

  7. Sealed source peer review plan

    SciTech Connect

    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

  8. Stabilizing geometry for hydrodynamic rotary seals

    DOEpatents

    Dietle, Lannie L.; Schroeder, John E.

    2010-08-10

    A hydrodynamic sealing assembly including a first component having first and second walls and a peripheral wall defining a seal groove, a second component having a rotatable surface relative to said first component, and a hydrodynamic seal comprising a seal body of generally ring-shaped configuration having a circumference. The seal body includes hydrodynamic and static sealing lips each having a cross-sectional area that substantially vary in time with each other about the circumference. In an uninstalled condition, the seal body has a length defined between first and second seal body ends which varies in time with the hydrodynamic sealing lip cross-sectional area. The first and second ends generally face the first and second walls, respectively. In the uninstalled condition, the first end is angulated relative to the first wall and the second end is angulated relative to the second wall. The seal body has a twist-limiting surface adjacent the static sealing lip. In the uninstalled condition, the twist-limiting surface is angulated relative to the peripheral wall and varies along the circumference. A seal body discontinuity and a first component discontinuity mate to prevent rotation of the seal body relative to the first component.

  9. High Pressure Rotary Shaft Sealing Mechanism

    DOEpatents

    Dietle, Lannie; Gobeli, Jeffrey D.

    2001-05-08

    A laterally translatable pressure staged rotary shaft sealing mechanism having a seal housing with a shaft passage therein being exposed to a fluid pressure P1 and with a rotary shaft being located within the shaft passage. At least one annular laterally translatable seal carrier is provided. First and second annular resilient sealing elements are supported in axially spaced relation by the annular seal carriers and have sealing relation with the rotary shaft. The seal housing and at least one seal carrier define a first pressure staging chamber exposed to the first annular resilient sealing element and a second pressure staging chamber located between and exposed to the first and second annular resilient sealing elements. A first fluid is circulated to the first pressure chamber at a pressure P1, and a second staging pressure fluid is circulated to the second pressure chamber at a fraction of pressure P1 to achieve pressure staging, cooling of the seals. Seal placement provides hydraulic force balancing of the annular seal carriers.

  10. Electrically insulating and sealing frame

    DOEpatents

    Guthrie, Robin J.

    1983-11-08

    A combination gas seal and electrical insulator having a closed frame shape interconnects a fuel cell stack and a reactant gas plenum of a fuel cell generator. The frame can be of rectangular shape including at least one slidable spline connection in each side to permit expansion or contraction consistent with that of the walls of the gas plenum and fuel cell stack. The slidable spline connections in the frame sides minimizes lateral movement between the frame side members and sealing material interposed between the frame and the fuel cell stack or between the frame and the reactant gas plenum.

  11. Air bearing vacuum seal assembly

    DOEpatents

    Booth, Rex

    1978-01-01

    An air bearing vacuum seal assembly capable of rotating at the speed of several thousand revolutions per minute using an air cushion to prevent the rotating and stationary parts from touching, and a two stage differential pumping arrangement to maintain the pressure gradient between the air cushion and the vacuum so that the leak rate into the vacuum is, for example, less than 1 .times. 10.sup.-4 Pa m.sup.3 /s. The air bearing vacuum seal has particular application for mounting rotating targets to an evacuated accelerator beam tube for bombardment of the targets with high-power charged particle beams in vacuum.

  12. Dual rotating shaft seal apparatus

    DOEpatents

    Griggs, J.E.; Newman, H.J.

    1983-06-16

    The report is directed to apparatus suitable for transferring torque and rotary motion through a wall in a manner which is essentially gas impermeable. The apparatus can be used for pressurizing, agitating, and mixing fluids and features two ferrofluidic, i.e., ferrometic seals. Each seal is disposed on one of two supported shafts and each shaft is operably connected at one end to a gear mechanism and at its other end to an adjustable coupling means which is to be connected to a rotatable shaft extending through a wall through which torque and rotary motion are to be transferred.

  13. High temperature sealed electrochemical cell

    SciTech Connect

    Valentin Chung, Brice Hoani; Burke, Paul J.; Sadoway, Donald R.

    2015-10-06

    A cell for high temperature electrochemical reactions is provided. The cell includes a container, at least a portion of the container acting as a first electrode. An extension tube has a first end and a second end, the extension tube coupled to the container at the second end forming a conduit from the container to said first end. A second electrode is positioned in the container and extends out of the container via the conduit. A seal is positioned proximate the first end of the extension tube, for sealing the cell.

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

    PubMed

    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

  15. Sealing Assembly for Sealing a Port and the Like

    NASA Technical Reports Server (NTRS)

    Haas, Jon W. (Inventor); Haupt, Charles W. (Inventor)

    2000-01-01

    The sealing assembly for a port of a valve or the like is disclosed. In detail, the sealing assembly includes the port having a circular shaped end with a circular shaped knife-edge thereon. The sealing assembly further includes a hollow cap having a closed first end with an aperture therethrough and an open second end. The cap further includes internal threads adapted to mate with the external threads of the port. A gasket is mounted within the cap having flat first and second principle sides and made of a deformable metal, the first principle side of the gasket for mounting against the circular shaped knife edge of the port. A plunger having a circular shaped disc portion is adapted to fit within the hollow cap and is engagable with the first principle surface of the gasket and includes a shaft portion extending out of the aperture. The cap and shaft of the plunger include external wrenching flats. Thus when the cap is screwed onto the port and the plunger is prevented from rotating by a wrench mounted on the wrenching flats of the shaft portion of the plunger, the gasket is forced into engagement with the knife edge in pure compression and no rotation of the gasket occurs causing the knife edge to locally deform the gasket sealing of the port.

  16. High temperature seal for large structural movements

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor); Dunlap, Jr., Patrick H. (Inventor)

    2004-01-01

    A high temperature sealing system is operative to seal an interface between adjacent hot structures and to minimize parasitic flow between such structures that move relative to one another in-plane or out-of-plane. The sealing system may be used to seal thrust-directing ramp structures of a reusable launch vehicle and includes a channel and a plurality of movable segmented sealing elements. Adjacent ramp structures include edge walls which extend within the channel. The sealing elements are positioned along the sides of the channel and are biased to engage with the inner surfaces of the ramp structures. The segmented sealing elements are movable to correspond to the contour of the thrust-directing ramp structures. The sealing system is operative to prevent high temperature thrust gases that flow along the ramp structures from infiltrating into the interior of the vehicle.

  17. Knife-edge seal for vacuum bagging

    NASA Technical Reports Server (NTRS)

    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.

  18. Seal Apparatus and Methods to Manufacture Thereof

    NASA Technical Reports Server (NTRS)

    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.

  19. Overview of LIDS Docking Seals Development

    NASA Technical Reports Server (NTRS)

    Dunlap, Patrick; Steinetz, Bruce; Daniels, Christopher

    2009-01-01

    GRC is supporting JSC by developing LIDS main interface seals Seal development and testing is occurring at both sub-scale and full-scale levels: a) Small-scale tests performed to define seal materials and evaluate exposure to space environments. b) Medium-scale testing: 1) Permits evaluation of candidate seal designs at faster pace than for full-scale seals. 2) Leak rates and loads can be scaled up to full-scale for indication of seal performance. c) Full-scale test rigs used for seal development and flight qualification tests and to assess on-orbit anomalies if needed. GRC responsible for delivering flight hardware seals to JSC approx.2013 for integration into LIDS flight units.

  20. Field testing of the Cobra Seal System

    SciTech Connect

    Yellin, E.; Vodrazka, P. ); Ystesund, K.; Drayer, D. )

    1990-01-01

    The Cobra Seal System consists of a passive fiber optic seal and verification equipment which have been modified to take advantage of current technology. The seal permits on-site verification without requiring replacement of the seal. The modifications to the original Cobra Seal System extended the maximum fiber optic cable length from 1 meter to 10 meters. This improvement allowed the Cobra Seal to be considered for application on dry irradiated fuel storage canisters at two Canadian facilities. These canisters are located in an exterior environment exposed to extreme weather conditions. This paper describe the application of the Cobra Seal to these canisters, a housing for the protection of the Cobra Seal body from the environment, and some preliminary results of the IAEA field tests. 4 refs.

  1. Film riding seals for rotary machines

    DOEpatents

    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.

  2. Compensating For Shrinkage In A Cryogenic Seal

    NASA Technical Reports Server (NTRS)

    Hill, Arnold E.

    1993-01-01

    Proposed design for seals in liquid-hydrogen plumbing eliminates leaks caused by contraction of seals at low operating temperature. Each seal consists of rubber, polytetrafluorethylene, or lead O-ring including hollow core filled with water. At temperature of liquid hydrogen, anomalous expansion of water keeps seal gland filled and leaktight despite shrinkage of surrounding O-ring material. Design also used in systems using cryogenic fluids other than liquid hydrogen.

  3. Dynamic Tester For Rotor Seals And Bearings

    NASA Technical Reports Server (NTRS)

    Von Pragenau, George L.

    1991-01-01

    Simplified apparatus measures performance under vibration. Measures some of dynamic parameters of rotor seals and bearings. Tests damping seals, damping bearings, conventional seals, and conventional bearings. Used with variety of pumped liquids, from water to liquid oxygen or hydrogen. Designed to test bearings and seals of turbopumps, tester rotates shaft at high speed while liquid flows much as it would in real turbopump. Also measures deflections of components.

  4. Non Destructive Seal Testing Polymeric Tray

    DTIC Science & Technology

    2006-10-01

    for 2 hours, the outside of the container seal is observed with a UV light to detect if the dye had penetrated through the seal. The dye test has been...electricity was 1micron (µm) in diameter and verified using transmitted light and a 1000-power microscope (Arndt et al., 1995). 3.1.8 Scanning...transmittance of heat energy (infrared light ) in a package or seal. Infrared light may be absorbed, transmitted, and emitted by a package or a seal

  5. Multi-layer seal for electrochemical devices

    DOEpatents

    Chou, Yeong-Shyung [Richland, WA; Meinhardt, Kerry D [Kennewick, WA; Stevenson, Jeffry W [Richland, WA

    2010-11-16

    Multi-layer seals are provided that find advantageous use for reducing leakage of gases between adjacent components of electrochemical devices. Multi-layer seals of the invention include a gasket body defining first and second opposing surfaces and a compliant interlayer positioned adjacent each of the first and second surfaces. Also provided are methods for making and using the multi-layer seals, and electrochemical devices including said seals.

  6. Multi-layer seal for electrochemical devices

    DOEpatents

    Chou, Yeong-Shyung [Richland, WA; Meinhardt, Kerry D [Kennewick, WA; Stevenson, Jeffry W [Richland, WA

    2010-09-14

    Multi-layer seals are provided that find advantageous use for reducing leakage of gases between adjacent components of electrochemical devices. Multi-layer seals of the invention include a gasket body defining first and second opposing surfaces and a compliant interlayer positioned adjacent each of the first and second surfaces. Also provided are methods for making and using the multi-layer seals, and electrochemical devices including said seals.

  7. Sealing apparatus utilizing a conformable member

    DOEpatents

    Neef, William S.; Lambert, Donald R.

    1988-01-01

    Sealing apparatus and method, comprising first and second surfaces or membranes, at least one of which surfaces is deformable, placed in proximity to one another. Urging means cause these surfaces to contact one another in a manner such that the deformable surface "deforms" to conform to the geometry of the other surface, thereby creating a seal. The seal is capable of undergoing multiple cycles of sealing and unsealing.

  8. Compressor seal rub energetics study

    NASA Technical Reports Server (NTRS)

    Laverty, W. F.

    1978-01-01

    The rub mechanics of compressor abradable blade tip seals at simulated engine conditions were investigated. Twelve statistically planned, instrumented rub tests were conducted with titanium blades and Feltmetal fibermetal rubstrips. The tests were conducted with single stationary blades rubbing against seal material bonded to rotating test disks. The instantaneous rub torque, speed, incursion rate and blade temperatures were continuously measured and recorded. Basic rub parameters (incursion rate, rub depth, abradable density, blade thickness and rub velocity) were varied to determine the effects on rub energy and heat split between the blade, rubstrip surface and rub debris. The test data was reduced, energies were determined and statistical analyses were completed to determine the primary and interactive effects. Wear surface morphology, profile measurements and metallographic analysis were used to determine wear, glazing, melting and material transfer. The rub energies for these tests were most significantly affected by the incursion rate while rub velocity and blade thickness were of secondary importance. The ratios of blade wear to seal wear were representative of those experienced in engine operation of these seal system materials.

  9. Pre-sealing risk analysis

    SciTech Connect

    Ensminger, D.A.; Hough, M.E.; Oston, S.G.

    1980-01-07

    This report describes studies of accidents involving high-level radioactive waste before sealing the waste into a repository. The report summarizes work done in this area during Fiscal Year 1978 and supplements previous work. Models of accident probability, severity, and consequences are refined and extended.

  10. SEAL /Subnetwork Enumeration And Listing/

    NASA Technical Reports Server (NTRS)

    Happ, W. W.; Mc Intosh, F. J.

    1968-01-01

    SEAL /Subnetwork Enumeration And Listing/ computer program uses combinatorial techniques to generate all of the nonredundant subnetwork configurations derivable from an asymmetrical network or device. This is accomplished by a systematic shorting and opening of accessible terminals to obtain the desired allowable configurations.

  11. FLUID PURIFIER AND SEALING VALVE

    DOEpatents

    Swanton, W.F.

    1962-04-24

    An improved cold trap designed to condense vapors and collect foreign particles in a flowing fluid is described. In the arrangement, a valve is provided to prevent flow reversal in case of pump failure and to act as a sealing valve. Provision is made for reducing the temperature of the fluid being processed, including a pre-cooling stage. (AEC)

  12. Hermetic Edge Seals for Photovoltaic Modules

    NASA Technical Reports Server (NTRS)

    Nowlan, M. J.

    1986-01-01

    Corrosive atmospheric agents excluded to prolong cell life. Combination of two sealing techniques makes possible to protect solar cells from water vapor, oxygen, and other corrosive atmospheric constituents. Using three-step process, glass-to-metal hermetic seal formed around edge of solar-cell module. Elastomer seals used previously not as effective because they are permeable to water vapor and atmospheric gases.

  13. Improved Seals for High Temperature Airframe Applications

    NASA Technical Reports Server (NTRS)

    DeMange, Jeffrey J.; Dunlap, Patrick H.; Steinetz, Bruce M.

    2006-01-01

    Current thermal barrier seals, such as those used on the Space Shuttle, are insufficient to fully meet the demands of future hypersonic vehicles and reentry spacecraft. Previous investigations have demonstrated limited usage temperatures, as evidenced by a decreased ability to maintain sealing effectiveness at high temperatures (i.e., inadequate resiliency). In order to improve resiliency at elevated temperatures, Rene 41 (Allvac) was substituted for Inconel X-750 (Special Metals Corp.) as the spring tube material in the existing seal design. A seal construction incorporating the Rene 41 spring tube was fabricated and tested against the baseline Inconel X-750 spring tube seal. Although resiliency improvements were not as dramatic as in previous tests with the spring tubes alone, seals incorporating the Rene 41 spring tube exhibited an average 20 percent resiliency enhancement up to 1750 F when compared to seals containing the Inconel spring tube. In addition, the seals with the Rene 41 spring tubes showed less reduction in resiliency as temperatures increased above 1200 F. Results also indicated the Saffil (Saffil Ltd.) insulation in the core of the seal contributed more to resiliency than previously thought. Leakage data did not demonstrate an improvement with the seal containing the Rene 41 spring tube. However, based upon resiliency results, one could reasonably expect the Rene 41 version of the seal to track gap openings over a wider range. Therefore it would exhibit lower leakage than the Inconel X-750 version as the seal gap opens during a typical mission.

  14. Piston rod seal for a Stirling engine

    SciTech Connect

    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.

  15. A Sample Return Container with Hermetic Seal

    NASA Technical Reports Server (NTRS)

    Kong, Kin Yuen; Rafeek, Shaheed; Sadick, Shazad; Porter, Christopher C.

    2000-01-01

    A sample return container is being developed by Honeybee Robotics to receive samples from a derivative of the Champollion/ST4 Sample Acquisition and Transfer Mechanism or other samplers and then hermetically seal samples for a sample return mission. The container is enclosed in a phase change material (PCM) chamber to prevent phase change during return and re-entry to earth. This container is designed to operate passively with no motors and actuators. Using the sampler's featured drill tip for interfacing, transfer-ring and sealing samples, the container consumes no electrical power and therefore minimizes sample temperature change. The circular container houses a few isolated canisters, which will be sealed individually for samples acquired from different sites or depths. The drill based sampler indexes each canister to the sample transfer position, below the index interface for sample transfer. After sample transfer is completed, the sampler indexes a seal carrier, which lines up seals with the openings of the canisters. The sampler moves to the sealing interface and seals the sample canisters one by one. The sealing interface can be designed to work with C-seals, knife edge seals and cup seals. Again, the sampler provides all sealing actuation. This sample return container and co-engineered sample acquisition system are being developed by Honeybee Robotics in collaboration with the JPL Exploration Technology program.

  16. Annular Pressure Seals and Hydrostatic Bearings

    DTIC Science & Technology

    2006-11-01

    affecting the rotordynamics of liquid turbopumps, in particular those handling large density fluids. Highlights on the bulk-flow analysis of annular seals... rotordynamic stability. Hydrostatic bearings rely on external fluid pressurization to generate load support and large centering stiffnesses, even in...SEALS IN PUMP APPLICATIONS Seal rotordynamic characteristic have a primary influence on the stability response of high-performance turbomachinery [1

  17. 1 CFR 18.8 - Seal.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 1 General Provisions 1 2010-01-01 2010-01-01 false Seal. 18.8 Section 18.8 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER PREPARATION, TRANSMITTAL, AND PROCESSING OF DOCUMENTS PREPARATION AND TRANSMITTAL OF DOCUMENTS GENERALLY § 18.8 Seal. Use of a seal on an original document...

  18. 19 CFR 201.0 - Seal.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 3 2013-04-01 2013-04-01 false Seal. 201.0 Section 201.0 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION GENERAL RULES OF GENERAL APPLICATION § 201.0 Seal. (a) Pursuant to... Trade Commission has adopted an official seal, the depiction of which follows: EC05OC91.026 (b)...

  19. 28 CFR 0.146 - Seals.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Seals. 0.146 Section 0.146 Judicial... Personnel and Certain Administrative Matters § 0.146 Seals. The Director of the Federal Bureau of... the U.S. Marshals Service shall each have custody of the seal pertaining to his...

  20. 19 CFR 201.0 - Seal.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 3 2014-04-01 2014-04-01 false Seal. 201.0 Section 201.0 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION GENERAL RULES OF GENERAL APPLICATION § 201.0 Seal. (a) Pursuant to... Trade Commission has adopted an official seal, the depiction of which follows: EC05OC91.026 (b)...

  1. 19 CFR 201.0 - Seal.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 3 2012-04-01 2012-04-01 false Seal. 201.0 Section 201.0 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION GENERAL RULES OF GENERAL APPLICATION § 201.0 Seal. (a) Pursuant to... Trade Commission has adopted an official seal, the depiction of which follows: EC05OC91.026 (b)...

  2. 40 CFR 147.3103 - Fluid seals.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Fluid seals. 147.3103 Section 147.3103... Tribes § 147.3103 Fluid seals. Notwithstanding §§ 144.28(f)(2) and 146.12(c) of this chapter, owners and operators shall not use a fluid seal as an alternative to a packer....

  3. 14 CFR 187.7 - Copies; seal.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Copies; seal. 187.7 Section 187.7... REGULATIONS FEES § 187.7 Copies; seal. The fees for furnishing photostatic or similar copies of documents and for affixation of the seal for a certification or validation are the same as those provided in...

  4. 28 CFR 0.146 - Seals.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Seals. 0.146 Section 0.146 Judicial... Personnel and Certain Administrative Matters § 0.146 Seals. The Director of the Federal Bureau of... the U.S. Marshals Service shall each have custody of the seal pertaining to his...

  5. 29 CFR 4002.11 - Seal.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 9 2014-07-01 2014-07-01 false Seal. 4002.11 Section 4002.11 Labor Regulations Relating to Labor (Continued) PENSION BENEFIT GUARANTY CORPORATION GENERAL BYLAWS OF THE PENSION BENEFIT GUARANTY CORPORATION § 4002.11 Seal. The seal of the Corporation shall be in such form as may be approved from time...

  6. 40 CFR 147.3103 - Fluid seals.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Fluid seals. 147.3103 Section 147.3103... Tribes § 147.3103 Fluid seals. Notwithstanding §§ 144.28(f)(2) and 146.12(c) of this chapter, owners and operators shall not use a fluid seal as an alternative to a packer....

  7. 19 CFR 201.0 - Seal.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Seal. 201.0 Section 201.0 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION GENERAL RULES OF GENERAL APPLICATION § 201.0 Seal. (a) Pursuant to... Trade Commission has adopted an official seal, the depiction of which follows: EC05OC91.026 (b)...

  8. 28 CFR 0.146 - Seals.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Seals. 0.146 Section 0.146 Judicial... Personnel and Certain Administrative Matters § 0.146 Seals. The Director of the Federal Bureau of... the U.S. Marshals Service shall each have custody of the seal pertaining to his...

  9. 19 CFR 201.0 - Seal.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 3 2011-04-01 2011-04-01 false Seal. 201.0 Section 201.0 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION GENERAL RULES OF GENERAL APPLICATION § 201.0 Seal. (a) Pursuant to... Trade Commission has adopted an official seal, the depiction of which follows: EC05OC91.026 (b)...

  10. 29 CFR 4002.11 - Seal.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 9 2012-07-01 2012-07-01 false Seal. 4002.11 Section 4002.11 Labor Regulations Relating to Labor (Continued) PENSION BENEFIT GUARANTY CORPORATION GENERAL BYLAWS OF THE PENSION BENEFIT GUARANTY CORPORATION § 4002.11 Seal. The seal of the Corporation shall be in such form as may be approved from time...

  11. 14 CFR 187.7 - Copies; seal.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Copies; seal. 187.7 Section 187.7... REGULATIONS FEES § 187.7 Copies; seal. The fees for furnishing photostatic or similar copies of documents and for affixation of the seal for a certification or validation are the same as those provided in...

  12. 1 CFR 18.8 - Seal.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 1 General Provisions 1 2013-01-01 2012-01-01 true Seal. 18.8 Section 18.8 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER PREPARATION, TRANSMITTAL, AND PROCESSING OF DOCUMENTS PREPARATION AND TRANSMITTAL OF DOCUMENTS GENERALLY § 18.8 Seal. Use of a seal on an original document...

  13. 14 CFR 187.7 - Copies; seal.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Copies; seal. 187.7 Section 187.7... REGULATIONS FEES § 187.7 Copies; seal. The fees for furnishing photostatic or similar copies of documents and for affixation of the seal for a certification or validation are the same as those provided in...

  14. 29 CFR 4002.11 - Seal.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 9 2011-07-01 2011-07-01 false Seal. 4002.11 Section 4002.11 Labor Regulations Relating to Labor (Continued) PENSION BENEFIT GUARANTY CORPORATION GENERAL BYLAWS OF THE PENSION BENEFIT GUARANTY CORPORATION § 4002.11 Seal. The seal of the Corporation shall be in such form as may be approved from time...

  15. 29 CFR 4002.11 - Seal.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 9 2013-07-01 2013-07-01 false Seal. 4002.11 Section 4002.11 Labor Regulations Relating to Labor (Continued) PENSION BENEFIT GUARANTY CORPORATION GENERAL BYLAWS OF THE PENSION BENEFIT GUARANTY CORPORATION § 4002.11 Seal. The seal of the Corporation shall be in such form as may be approved from time...

  16. 1 CFR 18.8 - Seal.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 1 General Provisions 1 2012-01-01 2012-01-01 false Seal. 18.8 Section 18.8 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER PREPARATION, TRANSMITTAL, AND PROCESSING OF DOCUMENTS PREPARATION AND TRANSMITTAL OF DOCUMENTS GENERALLY § 18.8 Seal. Use of a seal on an original document...

  17. 14 CFR 187.7 - Copies; seal.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Copies; seal. 187.7 Section 187.7... REGULATIONS FEES § 187.7 Copies; seal. The fees for furnishing photostatic or similar copies of documents and for affixation of the seal for a certification or validation are the same as those provided in...

  18. 1 CFR 18.8 - Seal.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 1 General Provisions 1 2011-01-01 2011-01-01 false Seal. 18.8 Section 18.8 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER PREPARATION, TRANSMITTAL, AND PROCESSING OF DOCUMENTS PREPARATION AND TRANSMITTAL OF DOCUMENTS GENERALLY § 18.8 Seal. Use of a seal on an original document...

  19. 40 CFR 147.3103 - Fluid seals.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Fluid seals. 147.3103 Section 147.3103... Tribes § 147.3103 Fluid seals. Notwithstanding §§ 144.28(f)(2) and 146.12(c) of this chapter, owners and operators shall not use a fluid seal as an alternative to a packer....

  20. 29 CFR 4002.11 - Seal.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Seal. 4002.11 Section 4002.11 Labor Regulations Relating to Labor (Continued) PENSION BENEFIT GUARANTY CORPORATION GENERAL BYLAWS OF THE PENSION BENEFIT GUARANTY CORPORATION § 4002.11 Seal. The seal of the Corporation shall be in such form as may be approved from time...

  1. 14 CFR 187.7 - Copies; seal.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Copies; seal. 187.7 Section 187.7... REGULATIONS FEES § 187.7 Copies; seal. The fees for furnishing photostatic or similar copies of documents and for affixation of the seal for a certification or validation are the same as those provided in...

  2. 1 CFR 18.8 - Seal.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 1 General Provisions 1 2014-01-01 2012-01-01 true Seal. 18.8 Section 18.8 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER PREPARATION, TRANSMITTAL, AND PROCESSING OF DOCUMENTS PREPARATION AND TRANSMITTAL OF DOCUMENTS GENERALLY § 18.8 Seal. Use of a seal on an original document...

  3. Rubber valve seal with tough skin

    NASA Technical Reports Server (NTRS)

    Martin, J. W.

    1979-01-01

    Curing technique for producing variable viscosity seal has hard sealing surface supported by softer rubber. Valve seal is clamped between two jaws for curing with hotter jaw at temperature of approximately 350 F and lower at room temperature. Result is durable tight valve-seat.

  4. Advanced bristle seals for gas turbine engines

    NASA Astrophysics Data System (ADS)

    Cabe, Jerry L.

    1993-01-01

    A seven month proof-of-concept program was conducted for an advanced bristle seal, called a bush seal, for use in gas turbine engines. This program was performed as a Small Business Innovation Research (SBIR) Phase 1 project. Bush seal specimen and a full ring bush seal were designed, evaluated, and manufactured for testing. An analytical study of the potential of the bush seal relative to a labyrinth seal was conducted. Static and dynamic testing of the bush seal was performed to determine the behavior of the bristles under pressurization and during contact with a rotating labyrinth tooth. Stable behavior of the bristle elements was observed during static pressurization of a full ring bush seal. The dynamic testing of various configurations of bush seal against a rotating labyrinth tooth showed minimal wear of the bristles relative to a conventional labyrinth seal. The development and application of the bush seal concept to gas turbine engines has the potential of improving the engine's performance while decreasing the degradation of the seal performance over time.

  5. High-Temperature, Bellows Hybrid Seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor); Sirocky, Paul J. (Inventor)

    1994-01-01

    A high-temperature hybrid seal is constructed of multiple elements to meet the many demands placed on the seal. The primary elements are: a central high-temperature bellows, a braided ceramic sheath covering the bellows, an outer abrasion resistant sheath covering the ceramic sheath, and a structurally-sound seal-end termination.

  6. Aerodynamic seal assemblies for turbo-machinery

    DOEpatents

    Bidkar, Rahul Anil; Wolfe, Christopher; Fang, Biao

    2015-09-29

    The present application provides an aerodynamic seal assembly for use with a turbo-machine. The aerodynamic seal assembly may include a number of springs, a shoe connected to the springs, and a secondary seal positioned about the springs and the shoe.

  7. ICESat Observations of Seasonal and Interannual Variations of Sea-Ice Freeboard and Estimated Thickness in the Weddell Sea, Antarctica (2003-2009)

    NASA Technical Reports Server (NTRS)

    Yi, Donghui; Robbins, John W.

    2010-01-01

    Sea-ice freeboard heights for 17 ICESat campaign periods from 2003 to 2009 are derived from ICESat data. Freeboard is combined with snow depth from Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) data and nominal densities of snow, water and sea ice, to estimate sea-ice thickness. Sea-ice freeboard and thickness distributions show clear seasonal variations that reflect the yearly cycle of growth and decay of the Weddell Sea (Antarctica) pack ice. During October-November, sea ice grows to its seasonal maximum both in area and thickness; the mean freeboards are 0.33-0.41 m and the mean thicknesses are 2.10-2.59 m. During February-March, thinner sea ice melts away and the sea-ice pack is mainly distributed in the west Weddell Sea; the mean freeboards are 0.35-0.46 m and the mean thicknesses are 1.48-1.94 m. During May-June, the mean freeboards and thicknesses are 0.26-0.29 m and 1.32-1.37 m, respectively. The 6 year trends in sea-ice extent and volume are (0.023+/-0.051) x 10(exp 6)sq km/a (0.45%/a) and (0.007+/-1.0.092) x 10(exp 3)cu km/a (0.08%/a); however, the large standard deviations indicate that these positive trends are not statistically significant.

  8. Dampers for Stationary Labyrinth Seals

    NASA Technical Reports Server (NTRS)

    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

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

    PubMed

    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.

  10. Factors affecting harp seal (Pagophilus groenlandicus) strandings in the Northwest Atlantic.

    PubMed

    Soulen, Brianne K; Cammen, Kristina; Schultz, Thomas F; Johnston, David W

    2013-01-01

    The effects of climate change on high latitude regions are becoming increasingly evident, particularly in the rapid decline of sea ice cover in the Arctic. Many high latitude species dependent on sea ice are being forced to adapt to changing habitats. Harp seals (Pagophilus groenlandicus) are an indicator species for changing high-latitude ecosystems. This study analyzed multiple factors including ice cover, demographics, and genetic diversity, which could affect harp seal stranding rates along the eastern coast of the United States. Ice cover assessments were conducted for the month of February in the Gulf of St. Lawrence whelping region from 1991-2010 using remote sensing data, and harp seal stranding data were collected over the same time period. Genetic diversity, which may affect how quickly species can adapt to changing climates, was assessed using ten microsatellite markers to determine mean d (2) in a subset of stranded and by-caught (presumably healthy) seals sampled along the northeast U.S. coast. Our study found a strong negative correlation (R (2) = 0.49) between ice cover in the Gulf of St. Lawrence and yearling harp seal strandings, but found no relationship between sea ice conditions and adult strandings. Our analysis revealed that male seals stranded more frequently than females during the study period and that this relationship was strongest during light ice years. In contrast, we found no significant difference in mean d (2) between stranded and by-caught harp seals. The results demonstrate that sea ice cover and demographic factors have a greater influence on harp seal stranding rates than genetic diversity, with only a little of the variance in mean d (2) among stranded seals explained by ice cover. Any changes in these factors could have major implications for harp seals, and these findings should be considered in the development of future management plans for the Arctic that incorporate climate variability.

  11. Actively controlled shaft seals for aerospace applications

    NASA Technical Reports Server (NTRS)

    Salant, Richard F.

    1994-01-01

    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 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 100 C. 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 changed suddenly.

  12. Method for producing a fuel cell manifold seal

    DOEpatents

    Grevstad, Paul E.; Johnson, Carl K.; Mientek, Anthony P.

    1982-01-01

    A manifold-to-stack seal and sealing method for fuel cell stacks. This seal system solves the problem of maintaining a low leak rate manifold seal as the fuel cell stack undergoes compressive creep. The seal system eliminates the problem of the manifold-to-stack seal sliding against the rough stack surface as the stack becomes shorter because of cell creep, which relative motion destroys the seal. The seal system described herein utilizes a polymer seal frame firmly clamped between the manifold and the stack such that the seal frame moves with the stack. Thus, as the stack creeps, the seal frame creeps with it, and there is no sliding at the rough, tough to seal, stack-to-seal frame interface. Here the sliding is on a smooth easy to seal location between the seal frame and the manifold.

  13. Challenges Of Interpreting Antarctic Pliocene Climate From The Sediment Record At ODP Sites 693 And 697 In The Weddell Sea

    NASA Astrophysics Data System (ADS)

    OConnell, S.; Cullen, K.; Flores, C.; Hall, J. T.; Kaufman, Z. S.

    2015-12-01

    The Weddell Sea receives sediment from both East and West Antarctica and records cryospheric changes in both ice sheets. Examination of Pliocene sediment from two ODP Sites (693 and 697) provides a history of ice rafted detritus (IRD), biosilica production and orbital pacing. Age dating at both sites is limited to shipboard biostratigraphy and paleomagnetics, yielding low age resolution. Using this age data we have attempted to correlate sedimentary changes with the LR04 benthic stack to provide a context with global oceanographic changes. Site 693 is adjacent to Dronning Maud Land on a shelf bench in 2480 m water and receives sediment exclusively from the East Antarctic Ice Sheet (EAIS). Detailed analysis of Core 8R, (approximately 1 sample/2-3 kyr) within Chron 2Ar (3.58-4.18 my) shows little variation in wt% biosilica and wt% IRD (fraction >63um). The exception is around 4 Ma when IRD is relatively constant at 2 wt%, while biosilica ranges 6 to 14%. These changes do not parallel the LR04 stack, suggesting limited interaction at this site with the global ocean. 40Ar/39Ar dating of hornblendes and biotites give a consistent age between 400-650 Ma (Pan African orogeny). The limited age range and composition, as well as small variation in % of IRD and biosilica suggest a single source and support the interpretation that this portion of the EAIS was relatively stable at this time. Site 697, in 3480 m water, lies in the Jane Basin, adjacent to the South Orkney Islands. The interval between 3.0 and 3.8 Ma has higher variation in both IRD (1-13%) and biosilica (2-12%) than Site 693, an expected outcome because its terrigeneous sediment source is dominated by the less stable West Antarctic Ice Sheet. Clear obliquity pacing, correlateable with part of the LR04 stack, is observed. However after 3.3 Ma, near the beginning of the Pliocene warm period, wt% IRD is less than 2% and biosilica increases to it's highest values. This suggests that few icebergs are reaching this far

  14. Dynamic analysis of noncontacting face seals

    NASA Technical Reports Server (NTRS)

    Etsion, I.

    1980-01-01

    The dynamic behavior of a noncontacting coned face seal is analyzed taking into account various design parameters and operating conditions. The primary seal ring motion is expressed by a set of nonlinear equations for three degrees of freedom. These equations, which are solved numerically, allow identification of two dimensionless groups of parameters that affect the seal dynamic behavior. Stability maps for various seals are presented. These maps contain a stable-to-unstable transition region in which the ring wobbles at half the shaft frequency. The effect of various parameters on seal stability is discussed and an empirical expression for critical stability is offered.

  15. Turbine Seal Research at NASA GRC

    NASA Technical Reports Server (NTRS)

    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.

  16. Energy conversion device with improved seal

    DOEpatents

    Miller, Gerald R.; Virkar, Anil V.

    1980-01-01

    An energy conversion device comprising an improved sealing member adapted to seal a cation-permeable casing to the remainder of the device. The sealing member comprises a metal substrate which (i) bears a nonconductive and corrosion resistant coating on the major surface to which said casing is sealed, and (ii) is corrugated so as to render it flexible, thereby allowing said member to move relative to said casing without cracking the seal therebetween. Corrugations may be circumferential, radial, or both radial and circumferential so as to form dimples. The corrugated member may be in form of a bellows or in a substantially flat form, such as a disc.

  17. Actively controlled shaft seals for aerospace applications

    NASA Technical Reports Server (NTRS)

    Salant, Richard F.

    1991-01-01

    The main objective is to determine the feasibility of utilizing controllable mechanical seals for aerospace applications. A potential application was selected as a demonstration case: the buffer gas seal in a LOX (liquid oxygen) turbopump. Currently, floating ring seals are used in this application. Their replacement with controllable mechanical seals would result in substantially reduced leakage rates. This would reduce the required amount of stored buffer gas, and therefore increase the vehicle payload. For such an application, a suitable controllable mechanical seal was designed and analyzed.

  18. Pump seal standard API 682 has deficiencies

    SciTech Connect

    Iyer, K.R.

    1997-08-01

    Struggling to meet ever-tightening, stringent emission regulations, hydrocarbon processing plants are evaluating all possible alternatives that can cut or eliminate fugitive releases. Nearly 70% of centrifugal pump maintenance is due to mechanical seal failures, a leading contributor to fugitive emissions. The new standard--API 682 was developed exclusively to set guidelines that dictate mechanical seal performance and specifications. API 682`s goal: define centrifugal pump seal-sealing systems performance and design criteria that will improve reliability, increase pump-seal service life and help control VOC emissions. The article reviews the pros and cons for API 682 from the pump-user`s viewpoint.

  19. Shape memory alloy seals for geothermal applications

    SciTech Connect

    Friske, Warren H.; Schwartzbart, Harry

    1982-10-08

    Rockwell International's Energy Systems Group, under contract to Brookhaven National Laboratory, has completed a 2-year program to develop a novel temperature-actuated seal concept for geothermal applications. This seal concept uses the unique properties of a shape memory alloy (Nitinol) to perform the sealing function. The several advantages of the concept are discussed in the paper. Demonstration tests of both face and shaft seals have shown that leaktight seals are feasible. Supporting materials studies have included corrosion tests in geothermal fluids, elevated temperature tensile tests, experimental electroplating and metallographic evaluations of microstructures.

  20. Experimental rotordynamic coefficient results for honeycomb seals

    NASA Technical Reports Server (NTRS)

    Elrod, David A.; Childs, Dara W.

    1988-01-01

    Test results (leakage and rotordynamic coefficients) are presented for seven honeycomb-stator smooth-rotor seals. Tests were carried out with air at rotor speeds up to 16,000 cpm and supply pressures up to 8.2 bars. Test results for the seven seals are compared, and the most stable configuration is identified based on the whirl frequency ratio. Results from tests of a smooth-rotor/smooth-stator seal, a teeth-on-stator labyrinth seal, and the most stable honeycomb seal are compared.