Science.gov

Sample records for adult harbor seals

  1. 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

  2. 78 FR 21597 - Marine Mammals: Alaska Harbor Seal Habitats

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-11

    ... National Oceanic and Atmospheric Administration RIN 0648-BB71 Marine Mammals: Alaska Harbor Seal Habitats... measures to protect glacially-associated harbor seal habitats in Alaska (78 FR 15669; March 12, 2013). During the workshops NMFS will present information regarding harbor seal habitat usage and...

  3. 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.

  4. Effects of sonic booms on breeding gray seals and harbor seals on Sable Island, Canada.

    PubMed

    Perry, Elizabeth A; Boness, Daryl J; Insley, Stephen J

    2002-01-01

    The Concorde produces audible sonic booms as it passes 15 km north of Sable Island, Nova Scotia, where gray and harbor seals occur year round. The purpose of this research was to assess how sonic booms affect these seals. The intensity of the booms was measured and three types of data (beach counts, frequency of behavior, and heart rate) were collected before and after booms during the breeding seasons of the two species. In addition to the data taken during breeding, beach counts were made before and after booms during the gray seal moult. The greatest range in overpressure within a single boom was 2.70 psf during gray seal breeding and 2.07 psf during harbor seal breeding. No significant differences were found in the behavior or beach counts of gray seals following sonic booms, regardless of the season. Beach counts and most behaviors of harbor seals also did not differ significantly following booms, however, harbor seals became more vigilant. The heart rates of four gray seal mothers and three pups showed no clear change as a result of booms, but six male harbor seals showed a nonsignificant tendency toward elevated heart rates during the 15-s interval of the boom. These results suggest sonic booms produced by the Concorde, in level flight at altitude and producing on average a sonic boom of 0.9 psf, do not substantially affect the breeding behavior of gray or harbor seals.

  5. Effects of sonic booms on breeding gray seals and harbor seals on Sable Island, Canada

    NASA Astrophysics Data System (ADS)

    Perry, Elizabeth A.; Boness, Daryl J.; Insley, Stephen J.

    2002-01-01

    The Concorde produces audible sonic booms as it passes 15 km north of Sable Island, Nova Scotia, where gray and harbor seals occur year round. The purpose of this research was to assess how sonic booms affect these seals. The intensity of the booms was measured and three types of data (beach counts, frequency of behavior, and heart rate) were collected before and after booms during the breeding seasons of the two species. In addition to the data taken during breeding, beach counts were made before and after booms during the gray seal moult. The greatest range in overpressure within a single boom was 2.70 psf during gray seal breeding and 2.07 psf during harbor seal breeding. No significant differences were found in the behavior or beach counts of gray seals following sonic booms, regardless of the season. Beach counts and most behaviors of harbor seals also did not differ significantly following booms, however, harbor seals became more vigilant. The heart rates of four gray seal mothers and three pups showed no clear change as a result of booms, but six male harbor seals showed a nonsignificant tendency toward elevated heart rates during the 15-s interval of the boom. These results suggest sonic booms produced by the Concorde, in level flight at altitude and producing on average a sonic boom of 0.9 psf, do not substantially affect the breeding behavior of gray or harbor seals.

  6. Dolphin Morbillivirus Infection in a Captive Harbor Seal (Phoca vitulina)

    PubMed Central

    Peletto, Simone; Mondin, Alessandra; Centelleghe, Cinzia; Di Guardo, Giovanni; Di Francesco, Cristina Esmeralda; Casalone, Cristina; Acutis, Pier Luigi

    2013-01-01

    During the second morbillivirus epidemic (2007 to 2011) in cetaceans along the Italian coastline, dolphin morbillivirus (DMV) was detected by molecular analyses in a captive harbor seal (Phoca vitulina), with pathological findings consistent with morbillivirus infection. This report confirms interspecies DMV transmission from cetaceans to pinnipeds. PMID:23224101

  7. Endocrine changes in harbor seal (Phoca vitulina) pups undergoing rehabilitation.

    PubMed

    Trumble, Stephen J; O'Neil, Danielle; Cornick, Leslie A; Gulland, Frances M D; Castellini, Michael A; Atkinson, Shannon

    2013-03-01

    Rehabilitating pinniped pups are often admitted to care centers as neonates and generally lack maternal investment and are in poor body condition. Upon admittance to a rehabilitation facility, pups are typically fed a milk replacement formula via gavage, which is switched to frozen fish upon weaning. While rehabilitation has been successful in terms of recovery and release, preweaning growth rates in captivity are consistently lower than in the wild. Indicators of stress (cortisol and total thyroxine; TT4), and standard morphometrics, of harbor seal pups in rehabilitation (n = 20) were determined for both preweaned and weaned pups. Hormone concentrations and standard morphometrics from pups in care were compared with free-ranging harbor seal pups (n = 59). Pups in rehabilitation gained mass on both milk and fish diets. Preweaned pups had greater mean serum cortisol and similar TT4 concentrations than weaned pups. Free-ranging harbor seal pups were heavier and longer than preweaned and weaned pups in rehabilitation. The free-ranging pups had the lowest cortisol and highest TT4 concentrations of any of the pups. These results suggest that weaned pups that have undergone rehabilitation are not physiologically equivalent to free-ranging weaned pups. Additional research is needed regarding physiological changes in endocrine values during early development under captive care conditions. This information should be useful to marine mammal rehabilitation centers in their development of care protocols and release criteria for rehabilitating harbor seal pups.

  8. Spatially Estimating Disturbance of Harbor Seals (Phoca vitulina)

    PubMed Central

    Jansen, John K.; Brady, Gavin M.; Ver Hoef, Jay M.; Boveng, Peter L.

    2015-01-01

    Tidewater glacial fjords in Alaska provide habitat for some of the largest aggregations of harbor seals (Phoca vitulina), with calved ice serving as platforms for birthing and nursing pups, molting, and resting. These fjords have also been popular destinations for tour ships for more than a century, with dramatic increases in vessel traffic since the 1980s. Seals on ice are known to flush into the water when approached by tour ships, but estimating the exposure to disturbance across populations is difficult. Using aerial transect sampling while simultaneously tracking vessel movements, we estimated the spatial overlap between seals on ice and cruise ships in Disenchantment Bay, Alaska, USA. By integrating previously estimated rates of disturbance as a function of distance with an ‘intensity surface’ modeled spatially from seal locations in the surveys, we calculated probabilities of seals flushing during three separate ship visits. By combining our estimate of seals flushed with a modeled estimate of the total fjord population, we predict that up to 14% of the seals (up to 11% of pups) hauled out would have flushed into the water, depending on the route taken by ships relative to seal aggregations. Such high potential for broad-scale disturbance by single vessels (when up to 4 ships visit per day) was unexpected and underscores the need to 1) better understand long-term effects of disturbance; 2) regularly monitor populations exposed to high vessel traffic; and 3) develop conservation measures to reduce seal-ship overlap. PMID:26132083

  9. Hiatal hernia in a harbor seal (Phoca vitulina) pup.

    PubMed

    Biancani, Barbara; Field, Cara L; Dennison, Sophie; Pulver, Robert; Tuttle, Allison D

    2012-06-01

    A 2-wk-old stranded harbor seal (Phoca vitulina) rescued by Mystic Aquarium showed signs of the presence of a hiatal hernia during rehabilitation. Contrast radiographs of esophagus and stomach revealed an intrathoracic radiodensity that contains filling defects typical of stomach, consistent with gastric rugal folds. Mural thickening was observed at the level of the cardia consistent with a diagnosis of a hiatal hernia. Although clinical improvement was noted with medical therapy and tube feeding, surgical correction of the hiatal hernia was considered necessary for full resolution. However, owing to the animal's low body weight, the corrective hernia surgery was postponed until the body condition improved. The seal needed to be surgically treated for a corneal ulcer, and while anesthetized with isoflurane, the seal became dyspneic and developed cardiac arrhythmias; ultimately cardiac arrest ensued. Resuscitation was unsuccessfully attempted and the seal was euthanized. Necropsy confirmed the radiographic diagnosis and further characterized a paraesophageal hiatal hernia.

  10. Seroprevalence of Toxoplasma gondii in North-eastern Atlantic harbor seal (Phoca vitulina vitulina) and grey seal (Halichoerus grypus).

    PubMed

    Cabezón, O; Hall, A J; Vincent, C; Pabón, M; García-Bocanegra, I; Dubey, J P; Almería, S

    2011-06-30

    Antibodies to Toxoplasma gondii were determined in serum samples from 47 grey seals (Halichoerus grypus) and 56 harbor seals (Phoca vitulina vitulina) from the Atlantic coasts of United Kingdom and France. Antibodies to T. gondii assayed by the modified agglutination test (MAT) were found in 14 (13.6%; IC(95%): 7.0-20.2) of 103 seals tested, with titres of 1:25 in 13 seals and 1:50 in 1 seal. Seroprevalence against T. gondii (MAT 1:25 or higher) was significantly higher in grey seals (23.4%) compared to harbor seals (5.4%). No significant differences were found between seroprevalence against T. gondii and sex, age or geographical locations. These results show natural exposure of European harbor and grey seals to T. gondii oocysts in the Atlantic Ocean. To the best of our knowledge, this is the first serological survey of T. gondii in European grey and harbor seals.

  11. New insights into the diets of harbor seals in the Salish Sea revealed by quantitative fatty acid signature analysis

    USGS Publications Warehouse

    Bromaghin, Jeffrey F.; Lance, Monique M.; Elliott, Elizabeth W.; Jeffries, Steven J.; Acevedo-Gutiérrez, Alejandro; Kennish, John M.

    2012-01-01

    Harbor seals (Phoca vitulina) are an abundant predator along the west coast of North America, and there is considerable interest in their diet composition, especially in regard to predation on valued fish stocks. Available information on harbor seal diets, primarily derived from scat analysis, suggests that adult salmon (Oncorhynchus spp.), Pacific Herring (Clupea pallasii), and gadids predominate. Because diet assessments based on scat analysis may be biased, we investigated diet composition through quantitative analysis of fatty acid signatures. Blubber samples from 49 harbor seals captured in western North America from haul-outs within the area of the San Juan Islands and southern Strait of Georgia in the Salish Sea were analyzed for fatty acid composition, along with 269 fish and squid specimens representing 27 potential prey classes. Diet estimates varied spatially, demographically, and among individual harbor seals. Findings confirmed the prevalence of previously identified prey species in harbor seal diets, but other species also contributed significantly. In particular, Black (Sebastes melanops) and Yellowtail (S. flavidus) Rockfish were estimated to compose up to 50% of some individual seal diets. Specialization and high predation rates on Black and Yellowtail Rockfish by a subset of harbor seals may play a role in the population dynamics of these regional rockfish stocks that is greater than previously realized.

  12. Long Distance Movements and Disjunct Spatial Use of Harbor Seals (Phoca vitulina) in the Inland Waters of the Pacific Northwest

    PubMed Central

    Peterson, Sarah H.; Lance, Monique M.; Jeffries, Steven J.; Acevedo-Gutiérrez, Alejandro

    2012-01-01

    Background Worldwide, adult harbor seals (Phoca vitulina) typically limit their movements and activity to <50 km from their primary haul-out site. As a result, the ecological impact of harbor seals is viewed as limited to relatively small spatial scales. Harbor seals in the Pacific Northwest are believed to remain <30 km from their primary haul-out site, one of several contributing factors to the current stock designation. However, movement patterns within the region are not well understood because previous studies have used radio-telemetry, which has range limitations. Our objective was to use satellite-telemetry to determine the regional spatial scale of movements. Methodology/Principal Findings Satellite tags were deployed on 20 adult seals (n=16 males and 4 females) from two rocky reefs and a mudflat-bay during April–May 2007. Standard filtering algorithms were used to remove outliers, resulting in an average (± SD) of 693 (±377) locations per seal over 110 (±32) days. A particle filter was implemented to interpolate locations temporally and decrease erroneous locations on land. Minimum over-water distances were calculated between filtered locations and each seal's capture site to show movement of seals over time relative to their capture site, and we estimated utilization distributions from kernel density analysis to reflect spatial use. Eight males moved >100 km from their capture site at least once, two of which traveled round trip to and from the Pacific coast, a total distance >400 km. Disjunct spatial use patterns observed provide new insight into general harbor seal behavior. Conclusions/Significance Long-distance movements and disjunct spatial use of adult harbor seals have not been reported for the study region and are rare worldwide in such a large proportion of tagged individuals. Thus, the ecological influence of individual seals may reach farther than previously assumed. PMID:22723925

  13. PIV Analysis of Wake Induced by Real Harbor Seal Whiskers

    NASA Astrophysics Data System (ADS)

    Bunjevac, Joseph; Rinehart, Aidan; Flaherty, Justin; Zhang, Wei

    2016-11-01

    Harbor Seals are able to accurately detect minute disturbances in the ambient flow using their whiskers, which is attributed to the exceptional capability of the whiskers to suppress vortex-induced vibrations in the wake. To explore potential applications for designing smart devices, such as high-sensitivity underwater flow sensors and drag reduction components, research has studied the role of key parameters of the whisker morphology on wake structure. Due to the inherent variation in size and angle of incidence along the length of whiskers, it is not well understood how a real seal whisker changes wake structure, in particular the vortex shedding behavior. This work aims to understand the flow around a single real seal whisker using Particle Image Velocimetry at low Reynolds numbers (i.e. a few hundred) in a water channel. Variations in flow structure are inspected between several different real whiskers and whisker models. The results will provide insights of the effects of the natural geometry of the harbor seal whiskers on wake flow compared to idealized whisker-like models.

  14. Comparative temporary threshold shifts in a harbor porpoise and harbor seal, and severe shift in a seal.

    PubMed

    Kastelein, Ronald A; Gransier, Robin; Hoek, Lean

    2013-07-01

    Anthropogenic noise may cause temporary hearing threshold shifts (TTSs) in marine mammals. Tests with identical methods show that harbor porpoises are more susceptible to TTS induced by octave-band white noise (OBN) centered around 4 kHz than harbor seals, although their unmasked (basic) hearing thresholds for that frequency are similar. A harbor seal was exposed for 1 h to an OBN with a very high sound pressure level (SPL), 22-30 dB above levels causing TTS onset. This elicited 44 dB TTS; hearing recovered within 4 days. Thus, for this signal and this single exposure, permanent threshold shift requires levels at least 22 dB above TTS onset levels. The severe TTS in the seal suggests that the critical level (above which TTS increases rapidly with increasing SPL) is between 150 and 160 dB re 1 μPa for a 60 min exposure to OBN centered at 4 kHz. In guidelines on TTS in marine mammals produced by policy makers in many countries, TTS is assumed to follow the equal energy hypothesis, so that when the sound exposure levels of fatiguing sounds are equal, the same TTS is predicted to be induced. However, like previous studies, the present study calls this model into question.

  15. Harbor Seals (Phoca vitulina) Can Perceive Optic Flow under Water

    PubMed Central

    Gläser, Nele; Mauck, Björn; Kandil, Farid I.; Lappe, Markus; Dehnhardt, Guido; Hanke, Frederike D.

    2014-01-01

    Optic flow, the pattern of apparent motion elicited on the retina during movement, has been demonstrated to be widely used by animals living in the aerial habitat, whereas underwater optic flow has not been intensively studied so far. However optic flow would also provide aquatic animals with valuable information about their own movement relative to the environment; even under conditions in which vision is generally thought to be drastically impaired, e. g. in turbid waters. Here, we tested underwater optic flow perception for the first time in a semi-aquatic mammal, the harbor seal, by simulating a forward movement on a straight path through a cloud of dots on an underwater projection. The translatory motion pattern expanded radially out of a singular point along the direction of heading, the focus of expansion. We assessed the seal's accuracy in determining the simulated heading in a task, in which the seal had to judge whether a cross superimposed on the flow field was deviating from or congruent with the actual focus of expansion. The seal perceived optic flow and determined deviations from the simulated heading with a threshold of 0.6 deg of visual angle. Optic flow is thus a source of information seals, fish and most likely aquatic species in general may rely on for e. g. controlling locomotion and orientation under water. This leads to the notion that optic flow seems to be a tool universally used by any moving organism possessing eyes. PMID:25058490

  16. Influenza A(H10N7) Virus in Dead Harbor Seals, Denmark

    PubMed Central

    Hansen, Mette S.; Holm, Elisabeth; Hjulsager, Charlotte K.; Chriél, Mariann; Pedersen, Karl; Andresen, Lars O.; Abildstrøm, Morten; Jensen, Trine H.; Larsen, Lars E.

    2015-01-01

    Since April 2014, an outbreak of influenza in harbor seals has been ongoing in northern Europe. In Denmark during June–August, 152 harbor seals on the island of Anholt were found dead from severe pneumonia. We detected influenza A(H10N7) virus in 2 of 4 seals examined. PMID:25811098

  17. 33 CFR 334.930 - Anaheim Bay Harbor, Calif.; Naval Weapons Station, Seal Beach.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Weapons Station, Seal Beach. 334.930 Section 334.930 Navigation and Navigable Waters CORPS OF ENGINEERS... Bay Harbor, Calif.; Naval Weapons Station, Seal Beach. (a) The restricted area. The water of Anaheim Bay Harbor between the east and west jetties at the United States Naval Weapons Station, Seal...

  18. 33 CFR 334.930 - Anaheim Bay Harbor, Calif.; Naval Weapons Station, Seal Beach.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Weapons Station, Seal Beach. 334.930 Section 334.930 Navigation and Navigable Waters CORPS OF ENGINEERS... Bay Harbor, Calif.; Naval Weapons Station, Seal Beach. (a) The restricted area. The water of Anaheim Bay Harbor between the east and west jetties at the United States Naval Weapons Station, Seal...

  19. 33 CFR 334.930 - Anaheim Bay Harbor, Calif.; Naval Weapons Station, Seal Beach.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Weapons Station, Seal Beach. 334.930 Section 334.930 Navigation and Navigable Waters CORPS OF ENGINEERS... Bay Harbor, Calif.; Naval Weapons Station, Seal Beach. (a) The restricted area. The water of Anaheim Bay Harbor between the east and west jetties at the United States Naval Weapons Station, Seal...

  20. 33 CFR 334.930 - Anaheim Bay Harbor, Calif.; Naval Weapons Station, Seal Beach.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Weapons Station, Seal Beach. 334.930 Section 334.930 Navigation and Navigable Waters CORPS OF ENGINEERS... Bay Harbor, Calif.; Naval Weapons Station, Seal Beach. (a) The restricted area. The water of Anaheim Bay Harbor between the east and west jetties at the United States Naval Weapons Station, Seal...

  1. 33 CFR 334.930 - Anaheim Bay Harbor, Calif.; Naval Weapons Station, Seal Beach.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Weapons Station, Seal Beach. 334.930 Section 334.930 Navigation and Navigable Waters CORPS OF ENGINEERS... Bay Harbor, Calif.; Naval Weapons Station, Seal Beach. (a) The restricted area. The water of Anaheim Bay Harbor between the east and west jetties at the United States Naval Weapons Station, Seal...

  2. Emergence of Fatal Avian Influenza in New England Harbor Seals

    PubMed Central

    Anthony, S. J.; St. Leger, J. A.; Pugliares, K.; Ip, H. S.; Chan, J. M.; Carpenter, Z. W.; Navarrete-Macias, I.; Sanchez-Leon, M.; Saliki, J. T.; Pedersen, J.; Karesh, W.; Daszak, P.; Rabadan, R.; Rowles, T.; Lipkin, W. I.

    2012-01-01

    ABSTRACT From September to December 2011, 162 New England harbor seals died in an outbreak of pneumonia. Sequence analysis of postmortem samples revealed the presence of an avian H3N8 influenza A virus, similar to a virus circulating in North American waterfowl since at least 2002 but with mutations that indicate recent adaption to mammalian hosts. These include a D701N mutation in the viral PB2 protein, previously reported in highly pathogenic H5N1 avian influenza viruses infecting people. Lectin staining and agglutination assays indicated the presence of the avian-preferred SAα-2,3 and mammalian SAα-2,6 receptors in seal respiratory tract, and the ability of the virus to agglutinate erythrocytes bearing either the SAα-2,3 or the SAα-2,6 receptor. The emergence of this A/harbor seal/Massachusetts/1/2011 virus may herald the appearance of an H3N8 influenza clade with potential for persistence and cross-species transmission. PMID:22851656

  3. Emergence of fatal avian influenza in New England harbor seals

    USGS Publications Warehouse

    Anthony, S.J.; St. Leger, J. A.; Pugliares, K.; Ip, H.S.; Chan, J.M.; Carpenter, Z.W.; Navarrete-Macias, I.; Sanchez-Leon, M.; Saliki, J.T.; Pedersen, J.; Karesh, W.; Daszak, P.; Rabadan, R.; Rowles, T.; Lipkin, W.I.

    2012-01-01

    From September to December 2011, 162 New England harbor seals died in an outbreak of pneumonia. Sequence analysis of postmortem samples revealed the presence of an avian H3N8 influenza A virus, similar to a virus circulating in North American waterfowl since at least 2002 but with mutations that indicate recent adaption to mammalian hosts. These include a D701N mutation in the viral PB2 protein, previously reported in highly pathogenic H5N1 avian influenza viruses infecting people. Lectin staining and agglutination assays indicated the presence of the avian-preferred SAα-2,3 and mammalian SAα-2,6 receptors in seal respiratory tract, and the ability of the virus to agglutinate erythrocytes bearing either the SAα-2,3 or the SAα-2,6 receptor. The emergence of this A/harbor seal/Massachusetts/1/2011 virus may herald the appearance of an H3N8 influenza clade with potential for persistence and cross-species transmission.

  4. Harbor Seal Vibrissa Morphology Reduces Vortex-Induced Vibrations

    NASA Astrophysics Data System (ADS)

    Beem, Heather; Dahl, Jason; Triantafyllou, Michael

    2011-11-01

    Studies show that harbor seals are adept at tracking small movements in the water, such as those left in the wake of fish, by using their highly sensitive whiskers to detect fluid structures, even without auditory or visual cues. The present work investigates the intriguing claim that the unique morphology of the harbor seal whisker suppresses Vortex Induced Vibrations (VIV). This implies that the geometry is specialized to reduce the background noise caused by the whisker's own wake in the detection of the upstream target. Forces on a rigid whisker model (scale: 50x) being towed steadily down a water tank while experiencing imposed oscillations are measured. A range of frequencies and amplitudes are tested, the hydrodynamic lift coefficient in phase with velocity (CL,v) is calculated for each, and values are combined in a contour plot. The region of positive CL,v peaks at an amplitude ratio of 0.1, indicating that the whisker's undulatory, asymmetric structure considerably reduces (but does not entirely suppress) regions where the structure experiences VIV in comparison with a standard cylinder, whose peak reaches an amplitude ratio of 0.8.

  5. Behavioral effects of environmental enrichment on harbor seals (Phoca vitulina concolor) and gray seals (Halichoerus grypus)

    USGS Publications Warehouse

    Hunter, S.A.; Bay, M.S.; Martin, M.L.; Hatfield, J.S.

    2002-01-01

    Zoos and aquariums have been incorporating environmental enrichment into their animal care programs for the past 30 years to increase mental stimulation and promote natural behaviors. However, most attempts to document the effects of enrichment on animal behavior have focused on terrestrial mammals. Staff at the National Aquarium in Baltimore conducted an investigation of the behavioral effects of enrichment on the seven harbor seals and two gray seals housed in the aquarium's outdoor seal exhibit. We expected that enrichment would change the amount of time the animals spent engaged in specific behaviors. The behaviors recorded were: resting in water, resting hauled out, maintenance, breeding display, breeding behavior, aggression, pattern swimming, random swimming, exploration, and out of sight. Activity levels (random swimming and exploration) were expected to increase, while stereotypic behaviors (pattern swimming) were expected to decrease. The frequency and duration of behaviors were documented for 90 hr in both the control phase (without enrichment) and the experimental phase (with enrichment). Statistically significant differences (P < 0.05) in the time spent in pattern swimming, random swimming, exploration, and out of sight were observed between the two phases. With enrichment, pattern swimming and out of sight decreased, while random swimming and exploration behavior increased. These findings demonstrate that enrichment can promote behaviors (random swimming and exploration) that are likely to be normal for phocids in the wild, and that may contribute to the behavioral complexity of these seals in captivity. ?? 2002 Wiley-Liss, Inc.

  6. Behavioral effects of environmental enrichment on harbor seals (Phoca vitulina concolor) and gray seals (Hafichoerus grypus)

    USGS Publications Warehouse

    Hunter, S.A.; Bay, M.S.; Martin, M.L.; Hatfield, J.S.

    2002-01-01

    Zoos and aquariums have been incorporating environmental enrichment into their animal care programs for the past 30 years to increase mental stimulation and promote natural behaviors. However, most attempts to document the effects of enrichment on animal behavior have focused on terrestrial mammals. Staff at the National Aquarium in Baltimore conducted an investigation of the behavioral effects of enrichment on the seven harbor seals and two gray seals housed in the aquarium's outdoor seal exhibit. We expected that enrichment would change the amount of time the animals spent engaged in specific behaviors. The behaviors recorded were: resting in water, resting hauled out, maintenance, breeding display, breeding behavior, aggression, pattern swimming, random swimming, exploration, and out of sight. Activity levels (random swimming and exploration) were expected to increase, while stereotypic behaviors (pattern swimming) were expected to decrease. The frequency and duration of behaviors were documented for 90 hr in both the control phase (without enrichment) and the experimental phase (with enrichment). Statistically significant differences (P<0.05) in the time spent in pattern swimming, random swimming, exploration, and out of sight were observed between the two phases. With enrichment, pattern swimming and out of sight decreased, while random swimming and exploration behavior increased. These findings demonstrate that enrichment can promote behaviors (random swimming and exploration) that are likely to be normal for phocids in the wild, and that may contribute to the behavioral complexity of these seals in captivity.

  7. Electrostatic stabilization in sperm whale and harbor seal myoglobins

    SciTech Connect

    Gurd, F.R.N.; Friend, S.H.; Rothgeb, T.M.; Gurd, R.S.; Scouloudi, H.

    1980-10-01

    The compact, largely helical structure of sperm whale and harbor seal myoglobins undergoes an abrupt one-step transition between pH 4.5 and 3.5 as monitored by changes in either the heme Soret band absorbance or circular dichroism probes of secondary structure, for which a modified Tanford-Kirkwood theory provides identification of certain dominant electrostatic interactions responsible for the loss of stability. A similar treatment permits identification of the electrostatic interactions primarily responsible for a process in which the anchoring of the A helix to other parts of the molecule is weakened. This process is detected with both myoglobins, in a pH range approx. 1 unit higher than the onset of the overall unfolding process, through changes in the circular dichroic spectra near 295 nm which correspond to the L/sub a/O-O band of the only two tryptophan residues in these proteins, residues 7 and 14. In each case protonation of certain sites in neighboring parts of the molecule can be identified as producing destabilizing interactions with components of the A helix, particularly with lysine 16.

  8. Toxic elements and organochlorines in harbor seals (Phoca vitulina richardsi), Kodiak, Alaska, USA

    USGS Publications Warehouse

    Miles, A.K.; Calkins, D.G.; Coon, N.C.

    1992-01-01

    Marine and estuarine habitats near urban or industrialized regions are vulnerable to contaminated runoff. Harbor seals (Phoca vitulina richardsi), which occur throughout much of the northern hemisphere, are useful mammalian biomonitors because they feed, reproduce, and rest near or on shore and are high-level trophic consumers. They have often been monitored for contaminants in Europe (Wagemann and Muir 1984). To date, no studies have been reported on contaminants in harbor seals from industrialized areas of Alaska. In the vicinity of Anchorage, Alaska's largest urban and industrial city, harbor seals are sedentary and limited to coastal waters; some movements have been documented but there is no evidence of extensive migrations. Although some harbor seals in the Kodiak Archipelago move up to 100 km along the shore, strong fidelity to specific haulout sites is more common (Pitcher and Calkins 1979). These seals eat mainly non-migratory fishes and octopi. Harbor seal numbers have declined substantially from unknown causes in the southern part of the Kodiak Archipelago. The Alaska Department of Fish and Game (ADF&G) suggested that the decline is a trend for the entire Kodiak region and other Alaskan waters. Contaminants have been suggested as a possible reason for the precipitous decline of Steller sea lions (Eumetopias jubatus) in the region (Braham et al. 1980), and were suspected in the decline of harbor seals. In this study, harbor seals were sampled from throughout the Kodiak Archipelago to determine concentrations of certain metals, metalloids, polychlorinated biphenyls (PCBs), and organochlorine pesticides, and to determine if these concentrations varied by sex or accumulated with age. All seals were collected within 75 km of Cook Inlet, an estuary next to Anchorage. The targeted elements or compounds were known to be toxic to a wide spectrum of organisms (e.g., MARC 1980; Eisler 1986).

  9. Underwater noise from three types of offshore wind turbines: estimation of impact zones for harbor porpoises and harbor seals.

    PubMed

    Tougaard, Jakob; Henriksen, Oluf Damsgaard; Miller, Lee A

    2009-06-01

    Underwater noise was recorded from three different types of wind turbines in Denmark and Sweden (Middelgrunden, Vindeby, and Bockstigen-Valar) during normal operation. Wind turbine noise was only measurable above ambient noise at frequencies below 500 Hz. Total sound pressure level was in the range 109-127 dB re 1 microPa rms, measured at distances between 14 and 20 m from the foundations. The 1/3-octave noise levels were compared with audiograms of harbor seals and harbor porpoises. Maximum 1/3-octave levels were in the range 106-126 dB re 1 microPa rms. Maximum range of audibility was estimated under two extreme assumptions on transmission loss (3 and 9 dB per doubling of distance, respectively). Audibility was low for harbor porpoises extending 20-70 m from the foundation, whereas audibility for harbor seals ranged from less than 100 m to several kilometers. Behavioral reactions of porpoises to the noise appear unlikely except if they are very close to the foundations. However, behavioral reactions from seals cannot be excluded up to distances of a few hundred meters. It is unlikely that the noise reaches dangerous levels at any distance from the turbines and the noise is considered incapable of masking acoustic communication by seals and porpoises.

  10. Seroprevalence of Toxoplasma gondii and Neospora caninum in north-eastern Atlantic Harbor seal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antibodies to Toxoplasma gondii and Neospora caninum were determined in serum samples from 47 grey seals (Halichoerus grypus) and 56 harbor seals (Phoca vitulina vitulina) from the Atlantic coasts of United Kingdom and France. Antibodies to T. gondii assayed by the modified agglutination test (MAT) ...

  11. Measuring hearing in the harbor seal (Phoca vitulina): comparison of behavioral and auditory brainstem response techniques.

    PubMed

    Wolski, Lawrence F; Anderson, Rindy C; Bowles, Ann E; Yochem, Pamela K

    2003-01-01

    Auditory brainstem response (ABR) and standard behavioral methods were compared by measuring in-air audiograms for an adult female harbor seal (Phoca vitulina). Behavioral audiograms were obtained using two techniques: the method of constant stimuli and the staircase method. Sensitivity was tested from 0.250 to 30 kHz. The seal showed good sensitivity from 6 to 12 kHz [best sensitivity 8.1 dB (re 20 microPa2 x s) RMS at 8 kHz]. The staircase method yielded thresholds that were lower by 10 dB on average than the method of constant stimuli. ABRs were recorded at 2, 4, 8, 16, and 22 kHz and showed a similar best range (8-16 kHz). ABR thresholds averaged 5.7 dB higher than behavioral thresholds at 2, 4, and 8 kHz. ABRs were at least 7 dB lower at 16 kHz, and approximately 3 dB higher at 22 kHz. The better sensitivity of ABRs at higher frequencies could have reflected differences in the seal's behavior during ABR testing and/or bandwidth characteristics of test stimuli. These results agree with comparisons of ABR and behavioral methods performed in other recent studies and indicate that ABR methods represent a good alternative for estimating hearing range and sensitivity in pinnipeds, particularly when time is a critical factor and animals are untrained.

  12. Measuring hearing in the harbor seal (Phoca vitulina): Comparison of behavioral and auditory brainstem response techniques

    NASA Astrophysics Data System (ADS)

    Wolski, Lawrence F.; Anderson, Rindy C.; Bowles, Ann E.; Yochem, Pamela K.

    2003-01-01

    Auditory brainstem response (ABR) and standard behavioral methods were compared by measuring in-air audiograms for an adult female harbor seal (Phoca vitulina). Behavioral audiograms were obtained using two techniques: the method of constant stimuli and the staircase method. Sensitivity was tested from 0.250 to 30 kHz. The seal showed good sensitivity from 6 to 12 kHz [best sensitivity 8.1 dB (re 20 μPa2.s) RMS at 8 kHz]. The staircase method yielded thresholds that were lower by 10 dB on average than the method of constant stimuli. ABRs were recorded at 2, 4, 8, 16, and 22 kHz and showed a similar best range (8-16 kHz). ABR thresholds averaged 5.7 dB higher than behavioral thresholds at 2, 4, and 8 kHz. ABRs were at least 7 dB lower at 16 kHz, and approximately 3 dB higher at 22 kHz. The better sensitivity of ABRs at higher frequencies could have reflected differences in the seal's behavior during ABR testing and/or bandwidth characteristics of test stimuli. These results agree with comparisons of ABR and behavioral methods performed in other recent studies and indicate that ABR methods represent a good alternative for estimating hearing range and sensitivity in pinnipeds, particularly when time is a critical factor and animals are untrained.

  13. Patterns of chlorinated biphenyl congeners in harbor seals (Phoca vitulina) and in their food: statistical analysis.

    PubMed

    Storr-Hansen, E; Spliid, H; Boon, J P

    1995-01-01

    Patterns of chlorinated biphenyl (CB) congeners have been compared in two groups of samples, namely blood samples from harbor seals (Phoca vitulina) and muscle tissue samples in the fish with which the seals were fed. The data originate from a Dutch controlled feeding study, performed in 1981 and 1983. The seals were living in captivity in two separate groups, and the fish samples were plaice (Pleuronectes platessa) from the Dutch part of the Wadden sea and mackerel (Scomber scombrus) from the Atlantic ocean. The levels of CB congeners were different in the two types of fish. The CB congener patterns of these four "matrices" were compared by analysis of principal components, and were found to be different in the two groups of harbor seals, which were fed the different types of fish. The corresponding CB congener patterns of the two groups of fish were also different. There was no indication for a relatively larger impact of biotransformation due to induction of isoforms of the cytochrome P450-system at the higher absolute CB congener levels in the Wadden sea group of seals compared to the Atlantic group of seals. The differentiation between the CB congener patterns in the two groups of seals in the Dutch study can be ascribed solely to different CB congener patterns in their food. The difference between CB congener patterns in the seals and in their diet can be explained by the structure-related biotransformation of the CB congeners in the harbor seal.

  14. Surveillance for zoonotic and selected pathogens in harbor seals Phoca vitulina from central California

    USGS Publications Warehouse

    Greig, Denise J.; Ip, Hon S.; Gulland, Frances M. D.; Miller, Woutrina A.; Conrad, Patricia A.; Field, Cara L.; Fleetwood, Michelle; Harvey, James T.; Jang, Spencer; Packham, Andrea; Wheeler, Elizabeth; Hall, Ailsa J.

    2014-01-01

    The infection status of harbor seals Phoca vitulina in central California, USA, was evaluated through broad surveillance for pathogens in stranded and wild-caught animals from 2001 to 2008, with most samples collected in 2007 and 2008. Stranded animals from Mendocino County to San Luis Obispo County were sampled at a rehabilitation facility: The Marine Mammal Center (TMMC, n = 175); wild-caught animals were sampled at 2 locations: San Francisco Bay (SF, n = 78) and Tomales Bay (TB, n = 97), that differed in degree of urbanization. Low prevalences of Salmonella, Campylobacter, Giardia, and Cryptosporidium were detected in the feces of stranded and wild-caught seals. Clostridium perfringens and Escherichia coli were more prevalent in the feces of stranded (58% [78 out of 135] and 76% [102 out of 135]) than wild-caught (42% [45 out of 106] and 66% [68 out of 106]) seals, whereas Vibrio spp. were 16 times more likely to be cultured from the feces of seals from SF than TB or TMMC (p < 0.005). Brucella DNA was detected in 3.4% of dead stranded harbor seals (2 out of 58). Type A influenza was isolated from feces of 1 out of 96 wild-caught seals. Exposure to Toxoplasma gondii, Sarcocystis neurona, and type A influenza was only detected in the wild-caught harbor seals (post-weaning age classes), whereas antibody titers to Leptospira spp. were detected in stranded and wild-caught seals. No stranded (n = 109) or wild-caught (n = 217) harbor seals had antibodies to phocine distemper virus, although a single low titer to canine distemper virus was detected. These results highlight the role of harbor seals as sentinel species for zoonotic and terrestrial pathogens in the marine environment.

  15. Surveillance for zoonotic and selected pathogens in harbor seals Phoca vitulina from central California.

    PubMed

    Greig, Denise J; Gulland, Frances M D; Smith, Woutrina A; Conrad, Patricia A; Field, Cara L; Fleetwood, Michelle; Harvey, James T; Ip, Hon S; Jang, Spencer; Packham, Andrea; Wheeler, Elizabeth; Hall, Ailsa J

    2014-09-30

    The infection status of harbor seals Phoca vitulina in central California, USA, was evaluated through broad surveillance for pathogens in stranded and wild-caught animals from 2001 to 2008, with most samples collected in 2007 and 2008. Stranded animals from Mendocino County to San Luis Obispo County were sampled at a rehabilitation facility: The Marine Mammal Center (TMMC, n = 175); wild-caught animals were sampled at 2 locations: San Francisco Bay (SF, n = 78) and Tomales Bay (TB, n = 97), that differed in degree of urbanization. Low prevalences of Salmonella, Campylobacter, Giardia, and Cryptosporidium were detected in the feces of stranded and wild-caught seals. Clostridium perfringens and Escherichia coli were more prevalent in the feces of stranded (58% [78 out of 135] and 76% [102 out of 135]) than wild-caught (42% [45 out of 106] and 66% [68 out of 106]) seals, whereas Vibrio spp. were 16 times more likely to be cultured from the feces of seals from SF than TB or TMMC (p < 0.005). Brucella DNA was detected in 3.4% of dead stranded harbor seals (2 out of 58). Type A influenza was isolated from feces of 1 out of 96 wild-caught seals. Exposure to Toxoplasma gondii, Sarcocystis neurona, and type A influenza was only detected in the wild-caught harbor seals (post-weaning age classes), whereas antibody titers to Leptospira spp. were detected in stranded and wild-caught seals. No stranded (n = 109) or wild-caught (n = 217) harbor seals had antibodies to phocine distemper virus, although a single low titer to canine distemper virus was detected. These results highlight the role of harbor seals as sentinel species for zoonotic and terrestrial pathogens in the marine environment.

  16. Influenza A (H10N7) Virus Causes Respiratory Tract Disease in Harbor Seals and Ferrets

    PubMed Central

    Herfst, Sander; Bodewes, Rogier; Pfankuche, Vanessa M.; van de Bildt, Marco W. G.; Seehusen, Frauke; Puff, Christina; Richard, Mathilde; Siebert, Ursula; Lehnert, Kristina; Bestebroer, Theo; Lexmond, Pascal; Fouchier, Ron A. M.; Prenger-Berninghoff, Ellen; Herbst, Werner; Koopmans, Marion; Osterhaus, Albert D. M. E.

    2016-01-01

    Avian influenza viruses sporadically cross the species barrier to mammals, including humans, in which they may cause epidemic disease. Recently such an epidemic occurred due to the emergence of avian influenza virus of the subtype H10N7 (Seal/H10N7) in harbor seals (Phoca vitulina). This epidemic caused high mortality in seals along the north-west coast of Europe and represented a potential risk for human health. To characterize the spectrum of lesions and to identify the target cells and viral distribution, findings in 16 harbor seals spontaneously infected with Seal/H10N7 are described. The seals had respiratory tract inflammation extending from the nasal cavity to bronchi associated with intralesional virus antigen in respiratory epithelial cells. Virus infection was restricted to the respiratory tract. The fatal outcome of the viral infection in seals was most likely caused by secondary bacterial infections. To investigate the pathogenic potential of H10N7 infection for humans, we inoculated the seal virus intratracheally into six ferrets and performed pathological and virological analyses at 3 and 7 days post inoculation. These experimentally inoculated ferrets displayed mild clinical signs, virus excretion from the pharynx and respiratory tract inflammation extending from bronchi to alveoli that was associated with virus antigen expression exclusively in the respiratory epithelium. Virus was isolated only from the respiratory tract. In conclusion, Seal/H10N7 infection in naturally infected harbor seals and experimentally infected ferrets shows that respiratory epithelial cells are the permissive cells for viral replication. Fatal outcome in seals was caused by secondary bacterial pneumonia similar to that in fatal human cases during influenza pandemics. Productive infection of ferrets indicates that seal/H10N7 may possess a zoonotic potential. This outbreak of LPAI from wild birds to seals demonstrates the risk of such occasions for mammals and thus humans

  17. Effect of angle of attack on the flow past a harbor seal vibrissa shaped cylinder

    NASA Astrophysics Data System (ADS)

    Kim, Hyo Ju; Yoon, Hyun Sik

    2016-11-01

    The present study considered the geometric disturbance inspired by a harbor seal vibrissa of which undulated surface structures are known as a detecting device to capture the water movement induced by prey fish. In addition, this vibrissa plays an important role to suppress vortex-induced vibration, which has been reported by the previous researches. The present study aims at finding the effect of the angle of attack (AOA) on flow characteristics around the harbor seal vibrissa shaped cylinder, since the flow direction facing the harbor seal vibrissa with the elliptic shape can be changed during the harbor seal's movements and surrounding conditions. Therefore, we considered a wide range of AOA varying from 0 to 90 degree. We carried out large eddy simulation (LES) to investigate the flow around inclined vibrissa shaped cylinder for the Reynolds number (Re) of 500 based hydraulic diameter of a harbor seal vibrissa shape. For comparison, the flow over the elliptic cylinder was also simulated according to AOA at the same Re. The vortical structures of both vibrissa shaped and elliptic cylinders have been compared to identify the fundamental mechanism making the difference flow quantities. This subject is supported by Korea Ministry of Environment (MOE) as "the Chemical Accident Prevention Technology Development Project.", National Research Foundation of Korea (NRF) Grant through GCRCSOP (No.20110030013) and (NRF-2015R1D1A3A01020867).

  18. Hearing thresholds of two harbor seals (Phoca vitulina) for playbacks of multiple pile driving strike sounds.

    PubMed

    Kastelein, Ronald A; Hoek, Lean; Gransier, Robin; Jennings, Nancy

    2013-09-01

    Pile driving, which creates high amplitude sounds with potentially negative impacts on the marine environment, is used to attach wind turbines to the sea bed. To quantify the distance at which pile driving sounds can be detected by harbor seals, unmasked hearing thresholds were obtained for series of five pile driving sounds recorded at 100 and 800 m from a pile driving location. The played back spectra resembled the spectra of sounds recorded under certain conditions 10-50 km from an offshore pile driving site. The lower the received level, the later within the series of sounds the harbor seals responded. The mean 50% detection threshold sound exposure levels for any sound in the series were: 40 (seal 01, 100 m), 39 (seal 01, 800 m), 43 (seal 02, 100 m), and 43 (seal 02, 800 m) dB re 1 μPa(2)s (add 9 dB for sound pressure level, dB re 1 μPa). The mean 50% detection thresholds based on detection of only the first sound of the series were ca. 5 dB higher. Detection at sea depends on the actual propagation conditions and on the degree of masking of the sounds by ambient noise, but the present study suggests that pile driving sounds are audible to harbor seals up to hundreds of kilometers from pile driving sites.

  19. Effects of growth, diving history, and high altitude on blood oxygen capacity in harbor seals

    NASA Technical Reports Server (NTRS)

    Kodama, A. M.; Elsner, R.; Pace, N.

    1977-01-01

    Blood volume and body composition for diving and nondiving harbor seals were measured at six-week intervals during a 10-month period of captitivity. Whole body hematocrit, red cell volume per kg of lean body mass, and total circulating hemoglobin per kg lean body mass were significantly higher in the diving group, but relatively large blood volumes expressed in terms of body weight (11-12%) were found in both groups. A pair of harbor seals exposed to high altitude for about three months registered significant increases in red cell volume, blood hemoglobin levels, and blood volume expressed in terms of body weight; results of alveolar gas analyses indicate that hyperventilation also occurred. These typical mammalian responses to hypoxia suggest that the harbor seal's large blood volume and high hemoglobin content are an expression of phylogenetic control, and that in spite of its adaptability to apnea during its diving life, the animal cannot be considered preacclimatized to high altitude.

  20. Individual-based energetic model suggests bottom up mechanisms for the impact of coastal hypoxia on Pacific harbor seal (Phoca vitulina richardii) foraging behavior.

    PubMed

    Steingass, Sheanna; Horning, Markus

    2017-03-07

    Wind-driven coastal hypoxia represents an environmental stressor that has the potential to drive redistribution of gilled marine organisms, and thereby indirectly affect the foraging characteristics of air-breathing upper trophic-level predators. We used a conceptual individual-based model to simulate effects of coastal hypoxia on the spatial foraging behavior and efficiency of a marine mammal, the Pacific harbor seal (Phoca vitulina richardii) on the Oregon coast. Habitat compression of fish was simulated at varying intensities of hypoxia. Modeled hypoxia affected up to 80% of the water column and half of prey species' horizontal habitat. Pacific sand lance (Ammodytes hexapterus), Pacific herring (Clupea pallasii), and English sole (Parophrys vetulus) were selected as representative harbor seal prey species. Model outputs most affected by coastal hypoxia were seal travel distance to foraging sites, time spent at depth during foraging dives, and daily energy balance. For larger seals, English sole was the most optimal prey during normoxia, however during moderate to severe hypoxia Pacific sand lance was the most beneficial prey. For smaller seals, Pacific herring was the most efficient prey species during normoxia, but sand lance became more efficient as hypoxia increased. Sand lance represented the highest increase in foraging efficiency during severe hypoxic events for all seals. Results suggest that during increasing hypoxia, smaller adult harbor seals could benefit by shifting from foraging on larger neritic schooling fishes to foraging closer inshore on less energetically-dense forage fish. Larger adult seals may benefit by shifting from foraging on groundfish to smaller, schooling neritic fishes as hypoxia increases. The model suggests a mechanism by which hypoxia may result in increased foraging efficiency of Pacific harbor seals, and therefore increased rates of predation on coastal fishes on the continental shelf during hypoxic events.

  1. Novel B19-Like Parvovirus in the Brain of a Harbor Seal

    PubMed Central

    Bodewes, Rogier; Rubio García, Ana; Wiersma, Lidewij C. M.; Getu, Sarah; Beukers, Martijn; Schapendonk, Claudia M. E.; van Run, Peter R. W. A.; van de Bildt, Marco W. G.; Poen, Marjolein J.; Osinga, Nynke; Sánchez Contreras, Guillermo J.; Kuiken, Thijs; Smits, Saskia L.; Osterhaus, Albert D. M. E.

    2013-01-01

    Using random PCR in combination with next-generation sequencing, a novel parvovirus was detected in the brain of a young harbor seal (Phoca vitulina) with chronic non-suppurative meningo-encephalitis that was rehabilitated at the Seal Rehabilitation and Research Centre (SRRC) in the Netherlands. In addition, two novel viruses belonging to the family Anelloviridae were detected in the lungs of this animal. Phylogenetic analysis of the coding sequence of the novel parvovirus, tentatively called Seal parvovirus, indicated that this virus belonged to the genus Erythrovirus, to which human parvovirus B19 also belongs. Although no other seals with similar signs were rehabilitated in SRRC in recent years, a prevalence study of tissues of seals from the same area collected in the period 2008-2012 indicated that the Seal parvovirus has circulated in the harbor seal population at least since 2008. The presence of the Seal parvovirus in the brain was confirmed by real-time PCR and in vitro replication. Using in situ hybridization, we showed for the first time that a parvovirus of the genus Erythrovirus was present in the Virchow-Robin space and in cerebral parenchyma adjacent to the meninges. These findings showed that a parvovirus of the genus Erythrovirus can be involved in central nervous system infection and inflammation, as has also been suspected but not proven for human parvovirus B19 infection. PMID:24223918

  2. Novel B19-like parvovirus in the brain of a harbor seal.

    PubMed

    Bodewes, Rogier; Rubio García, Ana; Wiersma, Lidewij C M; Getu, Sarah; Beukers, Martijn; Schapendonk, Claudia M E; van Run, Peter R W A; van de Bildt, Marco W G; Poen, Marjolein J; Osinga, Nynke; Sánchez Contreras, Guillermo J; Kuiken, Thijs; Smits, Saskia L; Osterhaus, Albert D M E

    2013-01-01

    Using random PCR in combination with next-generation sequencing, a novel parvovirus was detected in the brain of a young harbor seal (Phoca vitulina) with chronic non-suppurative meningo-encephalitis that was rehabilitated at the Seal Rehabilitation and Research Centre (SRRC) in the Netherlands. In addition, two novel viruses belonging to the family Anelloviridae were detected in the lungs of this animal. Phylogenetic analysis of the coding sequence of the novel parvovirus, tentatively called Seal parvovirus, indicated that this virus belonged to the genus Erythrovirus, to which human parvovirus B19 also belongs. Although no other seals with similar signs were rehabilitated in SRRC in recent years, a prevalence study of tissues of seals from the same area collected in the period 2008-2012 indicated that the Seal parvovirus has circulated in the harbor seal population at least since 2008. The presence of the Seal parvovirus in the brain was confirmed by real-time PCR and in vitro replication. Using in situ hybridization, we showed for the first time that a parvovirus of the genus Erythrovirus was present in the Virchow-Robin space and in cerebral parenchyma adjacent to the meninges. These findings showed that a parvovirus of the genus Erythrovirus can be involved in central nervous system infection and inflammation, as has also been suspected but not proven for human parvovirus B19 infection.

  3. 78 FR 15669 - Marine Mammals: Alaska Harbor Seal Habitats

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-12

    ... fjords that do not have specific rules regarding approaches to seals, and a recent study indicates that... regulations for vessel approaches to marine mammals, pursuant sections 112(a) of the MMPA and 11(f) of the ESA... the regulations. To date, NMFS has regulated close vessel approaches to marine mammals in...

  4. Selenium and mercury concentrations in harbor seals (Phoca vitulina) from central California: health implications in an urbanized estuary

    USGS Publications Warehouse

    McHuron, Elizabeth A.; Harvey, James T.; Castellini, J. Margaret; Stricker, Craig A.; O'Hara, Todd M.

    2014-01-01

    We measured total selenium and total mercury concentrations ([TSe] and [THg]) in hair (n = 138) and blood (n = 73) of harbor seals (Phoca vitulina) from California to assess variation by geography and sex, and inferred feeding relationships based on carbon, nitrogen, and sulfur stable isotopes. Harbor seals from Hg-contaminated sites had significantly greater [THg], and lesser [TSe] and TSe:THg molar ratios than seals from a relatively uncontaminated site. Males had significantly greater [THg] than females at all locations. Sulfur stable isotope values explained approximately 25% of the variability in [THg], indicating increased Hg exposure for seals with a greater use of estuarine prey species. Decreased [TSe] in harbor seals from Hg-contaminated regions may indicate a relative Se deficiency to mitigate the toxic effects of Hg. Further investigation into the Se status and the potential negative impact of Hg on harbor seals from Hg-contaminated sites is warranted.

  5. Saxitoxin increases phocine distemper virus replication upon in-vitro infection in harbor seal immune cells.

    PubMed

    Bogomolni, Andrea L; Bass, Anna L; Fire, Spencer; Jasperse, Lindsay; Levin, Milton; Nielsen, Ole; Waring, Gordon; De Guise, Sylvain

    2016-01-01

    Several marine mammal epizootics have been closely linked to infectious diseases, as well as to the biotoxins produced by harmful algal blooms (HABs). In two of three saxitoxin (STX) associated mortality events, dolphin morbillivirus (DMV) or phocine distemper virus (PDV) was isolated in affected individuals. While STX is notorious for its neurotoxicity, immunotoxic effects have also been described. This study investigated the role of STX in altering immune function, specifically T lymphocyte proliferation, in harbor seals (Phoca vitulina concolor) upon in-vitro exposure. In addition, the study also examined whether exposure to STX could alter the susceptibility of harbor seal immune cells to PDV infection upon in-vitro exposure. STX caused an increase in harbor seal lymphocyte proliferation at 10ppb and exposure to STX significantly increased the amount of virus present in lymphocytes. These results suggest that low levels of STX within the range of those reported in northeast U.S. seals may affect the likelihood of systemic PDV infection upon in-vivo exposure in susceptible seals. Given the concurrent increase in morbillivirus epizootics and HAB events in the last 25 years, the relationship between low level toxin exposure and host susceptibility to morbillivirus needs to be further explored.

  6. Diving Related Changes in the Blood Oxygen Stores of Rehabilitating Harbor Seal Pups (Phoca vitulina).

    PubMed

    Thomas, Amber; Ono, Kathryn

    2015-01-01

    Harbor seal (Phoca vitulina) pups begin diving within hours of birth, stimulating the development of the blood oxygen (O2) stores necessary to sustain underwater aerobic metabolism. Since harbor seals experience a brief nursing period, the early-life development of these blood O2 stores is necessary for successful post-weaning foraging. If mothers and pups become prematurely separated, the pup may be transported to a wildlife rehabilitation center for care. Previous studies suggest that the shallow pools and lack of diving in rehabilitation facilities may lead to under-developed blood O2 stores, but diving behavior during rehabilitation has not been investigated. This study aimed to simultaneously study the diving behaviors and blood O2 store development of rehabilitating harbor seal pups. Standard hematology measurements (Hct, Hb, RBC, MCV, MCH, MCHC) were taken to investigate O2 storage capacity and pups were equipped with time-depth recorders to investigate natural diving behavior while in rehabilitation. Linear mixed models of the data indicate that all measured blood parameters changed with age; however, when compared to literature values for wild harbor seal pups, rehabilitating pups have smaller red blood cells (RBCs) that can store less hemoglobin (Hb) and subsequently, less O2, potentially limiting their diving capabilities. Wild pups completed longer dives at younger ages (maximum reported <25 days of age: 9 min) in previous studies than the captive pups in this study (maximum <25 days of age: 2.86 min). However, captivity may only affect the rate of development, as long duration dives were observed (maximum during rehabilitation: 13.6 min at 89 days of age). Further, this study suggests that there may be a positive relationship between RBC size and the frequency of long duration dives. Thus, rehabilitating harbor seal pups should be encouraged to make frequent, long duration dives to prepare themselves for post-release foraging.

  7. Diving Related Changes in the Blood Oxygen Stores of Rehabilitating Harbor Seal Pups (Phoca vitulina)

    PubMed Central

    Thomas, Amber; Ono, Kathryn

    2015-01-01

    Harbor seal (Phoca vitulina) pups begin diving within hours of birth, stimulating the development of the blood oxygen (O2) stores necessary to sustain underwater aerobic metabolism. Since harbor seals experience a brief nursing period, the early-life development of these blood O2 stores is necessary for successful post-weaning foraging. If mothers and pups become prematurely separated, the pup may be transported to a wildlife rehabilitation center for care. Previous studies suggest that the shallow pools and lack of diving in rehabilitation facilities may lead to under-developed blood O2 stores, but diving behavior during rehabilitation has not been investigated. This study aimed to simultaneously study the diving behaviors and blood O2 store development of rehabilitating harbor seal pups. Standard hematology measurements (Hct, Hb, RBC, MCV, MCH, MCHC) were taken to investigate O2 storage capacity and pups were equipped with time-depth recorders to investigate natural diving behavior while in rehabilitation. Linear mixed models of the data indicate that all measured blood parameters changed with age; however, when compared to literature values for wild harbor seal pups, rehabilitating pups have smaller red blood cells (RBCs) that can store less hemoglobin (Hb) and subsequently, less O2, potentially limiting their diving capabilities. Wild pups completed longer dives at younger ages (maximum reported <25 days of age: 9 min) in previous studies than the captive pups in this study (maximum <25 days of age: 2.86 min). However, captivity may only affect the rate of development, as long duration dives were observed (maximum during rehabilitation: 13.6 min at 89 days of age). Further, this study suggests that there may be a positive relationship between RBC size and the frequency of long duration dives. Thus, rehabilitating harbor seal pups should be encouraged to make frequent, long duration dives to prepare themselves for post-release foraging. PMID:26061662

  8. 33 CFR 110.215 - Anaheim Bay Harbor, California; U.S. Naval Weapons Station, Seal Beach, California; Naval...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ....S. Naval Weapons Station, Seal Beach, California; Naval Explosives Anchorage. 110.215 Section 110... REGULATIONS Anchorage Grounds § 110.215 Anaheim Bay Harbor, California; U.S. Naval Weapons Station, Seal Beach... permission from the Commanding Officer, Naval Weapons Station, Seal Beach, California. This officer...

  9. 33 CFR 110.215 - Anaheim Bay Harbor, California; U.S. Naval Weapons Station, Seal Beach, California; Naval...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....S. Naval Weapons Station, Seal Beach, California; Naval Explosives Anchorage. 110.215 Section 110... REGULATIONS Anchorage Grounds § 110.215 Anaheim Bay Harbor, California; U.S. Naval Weapons Station, Seal Beach... permission from the Commanding Officer, Naval Weapons Station, Seal Beach, California. This officer...

  10. 33 CFR 110.215 - Anaheim Bay Harbor, California; U.S. Naval Weapons Station, Seal Beach, California; Naval...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....S. Naval Weapons Station, Seal Beach, California; Naval Explosives Anchorage. 110.215 Section 110... REGULATIONS Anchorage Grounds § 110.215 Anaheim Bay Harbor, California; U.S. Naval Weapons Station, Seal Beach... permission from the Commanding Officer, Naval Weapons Station, Seal Beach, California. This officer...

  11. 33 CFR 110.215 - Anaheim Bay Harbor, California; U.S. Naval Weapons Station, Seal Beach, California; Naval...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....S. Naval Weapons Station, Seal Beach, California; Naval Explosives Anchorage. 110.215 Section 110... REGULATIONS Anchorage Grounds § 110.215 Anaheim Bay Harbor, California; U.S. Naval Weapons Station, Seal Beach... permission from the Commanding Officer, Naval Weapons Station, Seal Beach, California. This officer...

  12. 33 CFR 110.215 - Anaheim Bay Harbor, California; U.S. Naval Weapons Station, Seal Beach, California; Naval...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....S. Naval Weapons Station, Seal Beach, California; Naval Explosives Anchorage. 110.215 Section 110... REGULATIONS Anchorage Grounds § 110.215 Anaheim Bay Harbor, California; U.S. Naval Weapons Station, Seal Beach... permission from the Commanding Officer, Naval Weapons Station, Seal Beach, California. This officer...

  13. Tissue-specific accumulation of polybrominated diphenyl ethers (PBDEs) including Deca-BDE and hexabromocyclododecanes (HBCDs) in harbor seals from the northwest Atlantic.

    PubMed

    Shaw, Susan D; Berger, Michelle L; Weijs, Liesbeth; Covaci, Adrian

    2012-09-01

    Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) are widely used flame retardants that enter coastal waters from multiple sources and biomagnify in marine food webs. PBDEs have been detected at relatively high concentrations in harbor seals, apex predators in the northwest Atlantic. Whereas tri- to hexa-BDEs readily biomagnified from prey fishes to seal blubber, Deca-BDE (BDE-209) did not biomagnify in blubber. To explore tissue-specific differences in the accumulation/biomagnification of BFRs, we analyzed tri- to Deca-BDES in liver of 56 harbor seals (6 adult males, 50 pups), and compared hepatic concentrations and biomagnification potential with those in blubber. HBCDs were analyzed in seal liver and blubber to enable similar comparisons. Hepatic ΣPBDE (tri- to Octa-BDE) concentrations (range 35-19,547ng/glipid weight, lw) were similar to blubber concentrations, while α-HBCD levels in seal liver (range 2-279ng/glw) were significantly higher than levels in blubber. Tissue distribution of PBDEs and α-HBCD varied significantly by age and, surprisingly, by gender among the pups. Biomagnification of α-HBCD from fish to seal liver and blubber was negligible to low, implying that harbor seals can metabolize this persistent isomer. Similar to the patterns in blubber, tri- through hexa-BDEs were highly biomagnified from fish to seal liver. In contrast, BDE-209 concentrations in liver were up to five times higher than those in blubber, which is consistent with observations that BDE-209 migrates to perfused tissues such as the liver in biota. Although detection frequency was low, BDE-209 levels in seal liver were up to ten times higher than those in their prey fish, suggesting that the accumulation/biomagnification of Deca-BDE in marine food webs is tissue-specific. As BDE-209 is the dominant PBDE found in marine sediments, its biomagnification in marine ecosystems is of concern.

  14. Phocine herpesvirus 1 (PhHV-1) in harbor seals from Svalbard, Norway.

    PubMed

    Roth, Swaantje J; Tischer, B Karsten; Kovacs, Kit M; Lydersen, Christian; Osterrieder, Nikolaus; Tryland, Morten

    2013-06-28

    Phocine herpesvirus 1 (PhHV-1) infections in seals are associated with disease and sometimes high mortality, primarily in young animals. PhHV-1 has been detected in seals from European waters as well as in waters on both coasts of North America. Serological surveys of various pinniped species have indicated a wide geographical distribution of PhHV-1. A quantitative and sensitive real-time PCR assay targeting the gene encoding glycoprotein B of PhHV-1 was developed for detection of PhHV-1 in ocular and nasal swab samples from wild harbor seals (Phoca vitulina) from Svalbard (Norway). PhHV-1 DNA was detected in samples from 6 (8%) seals collected in 2009 and 2 (3%) in 2010; all had herpesvirus DNA in the ocular swab sample, whereas only one of these animals also had herpesvirus DNA in the nasal swab sample. Four PCR positive animals were approximately 1 year of age and four were pups of the year. Serum samples obtained in 1998 (n=59), 1999 (n=74), 2000 (n=81), 2009 (n=69) and 2010 (n=83) were tested for anti-PhHV-1 antibodies in an indirect ELISA. The PhHV-1 seroprevalence in the population remained high throughout this period, varying from 77 to 100% between years. No eye disease was observed in this harbor seal population, but the ELISA and PCR findings reported here suggest that PhHV-1 is endemic in this globally northernmost harbor seal colony, and that the virus is shed on the mucosa of the eye and nose.

  15. Seasonal Variation of Harbor Seal's Diet from the Wadden Sea in Relation to Prey Availability

    PubMed Central

    de la Vega, Camille; Lebreton, Benoit; Siebert, Ursula; Guillou, Gael; Das, Krishna; Asmus, Ragnhild; Asmus, Harald

    2016-01-01

    The Wadden Sea has an important role for marine mammals in terms of resting, nursing and foraging. Harbor seal is the most abundant marine mammal species in this area. The use of the food resources of the Wadden Sea by seals is not clear, and previous studies showed that this species can travel kilometers away from their haul-outs to forage in the North Sea. In this study, we analyzed the stable isotopes of vibrissae from 23 dead harbor seals found on the island of Sylt to investigate their diet. The predator´s carbon and nitrogen isotope compositions were compared to the compositions of different potential prey items from the Sylt-Rømø Bight and from the North Sea in order to study seasonal pattern in the diet and in the foraging location. In parallel, seasonal variation of abundance and biomass of the potential prey items from the Sylt-Rømø Bight were studied and compare to their contribution to the seal´s diet. The results revealed a change in the seal´s diet from pelagic sources in spring to a benthic based diet in summer, and an increasing use of the North Sea resources in fall and winter in accordance with the seasonal variation of the availability of prey in the Sylt-Rømø Bight. PMID:27176227

  16. Seasonal Variation of Harbor Seal's Diet from the Wadden Sea in Relation to Prey Availability.

    PubMed

    de la Vega, Camille; Lebreton, Benoit; Siebert, Ursula; Guillou, Gael; Das, Krishna; Asmus, Ragnhild; Asmus, Harald

    2016-01-01

    The Wadden Sea has an important role for marine mammals in terms of resting, nursing and foraging. Harbor seal is the most abundant marine mammal species in this area. The use of the food resources of the Wadden Sea by seals is not clear, and previous studies showed that this species can travel kilometers away from their haul-outs to forage in the North Sea. In this study, we analyzed the stable isotopes of vibrissae from 23 dead harbor seals found on the island of Sylt to investigate their diet. The predator´s carbon and nitrogen isotope compositions were compared to the compositions of different potential prey items from the Sylt-Rømø Bight and from the North Sea in order to study seasonal pattern in the diet and in the foraging location. In parallel, seasonal variation of abundance and biomass of the potential prey items from the Sylt-Rømø Bight were studied and compare to their contribution to the seal´s diet. The results revealed a change in the seal´s diet from pelagic sources in spring to a benthic based diet in summer, and an increasing use of the North Sea resources in fall and winter in accordance with the seasonal variation of the availability of prey in the Sylt-Rømø Bight.

  17. Assay dependence of Brucella antibody prevalence in a declining Alaskan harbor seal (Phoca vitulina) population

    PubMed Central

    2013-01-01

    Background Brucella is a group of bacteria that causes brucellosis, which can affect population health and reproductive success in many marine mammals. We investigated the serological prevalence of antibodies against Brucella bacteria in a declining harbor seal population in Glacier Bay National Park, Alaska. Results Prevalence ranged from 16 to 74 percent for those tests detecting antibodies, indicating that harbor seals in Glacier Bay have been exposed to Brucella bacteria. However, the actual level of serological prevalence could not be determined because results were strongly assay-dependent. Conclusions This study reinforces the need to carefully consider assay choice when comparing different studies on the prevalence of anti–Brucella antibodies in pinnipeds and further highlights the need for species- or taxon-specific assay validation for both pathogen and host species. PMID:23324565

  18. Underwater sound localization of pure tones in the median plane by harbor seals (Phoca vitulina).

    PubMed

    Byl, Jenny Ann; Miersch, Lars; Wieskotten, Sven; Dehnhardt, Guido

    2016-12-01

    In an underwater environment the physical characteristics of sound propagation differ considerably from those in air. For this reason, sound localization underwater is associated with difficulties, especially in the median plane. It was the approach of the present study to investigate whether harbor seals (Phoca vitulina) are able to determine the direction of a tonal signal form above or below in the underwater environment. Minimum audible angles (MAAs) or the angular range in which the animals could localize a pure tone stimulus in the vertical plane were obtained for frequencies from 0.35 up to 16 kHz. Testing was conducted with four male harbor seals in a semi-circle area of 6 m in diameter in about 2.5 m depth, by using a two alternative forced choice method. The results show that harbor seals are able to localize a pure tone in the median plane under water with a high performance for low frequency stimuli between 350 Hz and 2 kHz with MAAs ranging from below 2.5° up to about 25°. For higher frequencies the animals show strong individual differences.

  19. Alaska harbor seal (Phoca vitulina) contaminants: A review with annotated bibliography

    SciTech Connect

    Papa, R.S.; Becker, P.R.

    1998-10-01

    The numbers of harbor seals (Phoca vitulina) have declined steadily and substantially over the last two decades in the Central and Western Gulf of Alaska, including Prince William Sound. Although the reasons for this decline have not been identified, hypotheses have included fishery interactions, changes in availability of food resources, human harvests, disease, increase in predation, increase in disturbance, and pollution. Although the presence of contaminants has been suggested as one possible causative factor in the decline of both the harbor seal and Steller sea lion, very little information is readily available on contaminant concentrations in these animals. As an initial step in the development of a database that can be used to define the types of studies needed to address the possible role of anthropogenic contaminants in the decline of this species, existing data and information on levels of contaminants in the harbor seals of Alaska, the contiguous U.S., and other areas of the world were reviewed. This report provides references and current scientific literature, as well as gray literature and unpublished databases. This report is divided into three sections: (1) a synthesis of information based on the review, (2) tables that summarize the published data, and (3) an annotated bibliography.

  20. New England harbor seal H3N8 influenza virus retains avian-like receptor specificity

    PubMed Central

    Hussein, Islam T. M.; Krammer, Florian; Ma, Eric; Estrin, Michael; Viswanathan, Karthik; Stebbins, Nathan W.; Quinlan, Devin S.; Sasisekharan, Ram; Runstadler, Jonathan

    2016-01-01

    An influenza H3N8 virus, carrying mammalian adaptation mutations, was isolated from New England harbor seals in 2011. We sought to assess the risk of its human transmissibility using two complementary approaches. First, we tested the binding of recombinant hemagglutinin (HA) proteins of seal H3N8 and human-adapted H3N2 viruses to respiratory tissues of humans and ferrets. For human tissues, we observed strong tendency of the seal H3 to bind to lung alveoli, which was in direct contrast to the human-adapted H3 that bound mainly to the trachea. This staining pattern was also consistent in ferrets, the primary animal model for human influenza pathogenesis. Second, we compared the binding of the recombinant HAs to a library of 610 glycans. In contrast to the human H3, which bound almost exclusively to α-2,6 sialylated glycans, the seal H3 bound preferentially to α-2,3 sialylated glycans. Additionally, the seal H3N8 virus replicated in human lung carcinoma cells. Our data suggest that the seal H3N8 virus has retained its avian-like receptor binding specificity, but could potentially establish infection in human lungs. PMID:26888262

  1. Haul-out behavior of harbor seals (Phoca vitulina) in Hood Canal, Washington.

    PubMed

    London, Josh M; Ver Hoef, Jay M; Jeffries, Steven J; Lance, Monique M; Boveng, Peter L

    2012-01-01

    The goal of this study was to model haul-out behavior of harbor seals (Phoca vitulina) in the Hood Canal region of Washington State with respect to changes in physiological, environmental, and temporal covariates. Previous research has provided a solid understanding of seal haul-out behavior. Here, we expand on that work using a generalized linear mixed model (GLMM) with temporal autocorrelation and a large dataset. Our dataset included behavioral haul-out records from archival and VHF radio tag deployments on 25 individual seals representing 61,430 seal hours. A novel application for increased computational efficiency allowed us to examine this large dataset with a GLMM that appropriately accounts for temporal autocorellation. We found significant relationships with the covariates hour of day, day of year, minutes from high tide and year. Additionally, there was a significant effect of the interaction term hour of day : day of year. This interaction term demonstrated that seals are more likely to haul out during nighttime hours in August and September, but then switch to predominantly daylight haul-out patterns in October and November. We attribute this change in behavior to an effect of human disturbance levels. This study also examined a unique ecological event to determine the role of increased killer whale (Orcinus orca) predation on haul-out behavior. In 2003 and 2005 these harbor seals were exposed to unprecedented levels of killer whale predation and results show an overall increase in haul-out probability after exposure to killer whales. The outcome of this study will be integral to understanding any changes in population abundance as a result of increased killer whale predation.

  2. Haul-Out Behavior of Harbor Seals (Phoca vitulina) in Hood Canal, Washington

    PubMed Central

    London, Josh M.; Ver Hoef, Jay M.; Jeffries, Steven J.; Lance, Monique M.; Boveng, Peter L.

    2012-01-01

    The goal of this study was to model haul-out behavior of harbor seals (Phoca vitulina) in the Hood Canal region of Washington State with respect to changes in physiological, environmental, and temporal covariates. Previous research has provided a solid understanding of seal haul-out behavior. Here, we expand on that work using a generalized linear mixed model (GLMM) with temporal autocorrelation and a large dataset. Our dataset included behavioral haul-out records from archival and VHF radio tag deployments on 25 individual seals representing 61,430 seal hours. A novel application for increased computational efficiency allowed us to examine this large dataset with a GLMM that appropriately accounts for temporal autocorellation. We found significant relationships with the covariates hour of day, day of year, minutes from high tide and year. Additionally, there was a significant effect of the interaction term hour of day : day of year. This interaction term demonstrated that seals are more likely to haul out during nighttime hours in August and September, but then switch to predominantly daylight haul-out patterns in October and November. We attribute this change in behavior to an effect of human disturbance levels. This study also examined a unique ecological event to determine the role of increased killer whale (Orcinus orca) predation on haul-out behavior. In 2003 and 2005 these harbor seals were exposed to unprecedented levels of killer whale predation and results show an overall increase in haul-out probability after exposure to killer whales. The outcome of this study will be integral to understanding any changes in population abundance as a result of increased killer whale predation. PMID:22723851

  3. Behavior associated with forced copulation of juvenile Pacific harbor seals (Phoca vitulina richardsi) by southern sea otters (Enhydra lutris nereis)

    USGS Publications Warehouse

    Harris, Heather S.; Oates, Stori C.; Staedler, Michelle M.; Tinker, M. Tim; Jessup, David A.; Harvey, James T.; Miller, Melissa A.

    2010-01-01

    Nineteen occurrences of interspecific sexual behavior between male southern sea otters (Enhydra lutris nereis) and juvenile Pacific harbor seals (Phoca vitulina richardsi) were reported in Monterey Bay, California, between 2000 and 2002. At least three different male sea otters were observed harassing, dragging, guarding, and copulating with harbor seals for up to 7 d postmortem. Carcasses of 15 juvenile harbor seals were recovered, and seven were necropsied in detail by a veterinary pathologist. Necropsy findings from two female sea otters that were recovered dead from male sea otters exhibiting similar behavior are also presented to facilitate a comparison of lesions. The most frequent lesions included superficial skin lacerations; hemorrhage around the nose, eyes, flippers, and perineum; and traumatic corneal erosions or ulcers. The harbor seals sustained severe genital trauma, ranging from vaginal perforation to vagino-cervical transection, and colorectal perforations as a result of penile penetration. One harbor seal developed severe pneumoperitoneum subsequent to vaginal perforation, which was also observed in both female sea otters and has been reported as a postcoital lesion in humans. This study represents the first description of lesions resulting from forced copulation of harbor seals by sea otters and is also the first report of pneu-moperitoneum secondary to forced copulation in a nonhuman animal. Possible explanations for this behavior are discussed in the context of sea otter biology and population demographics.

  4. The effects of experimentally induced hyperthyroidism on the diving physiology of harbor seals (Phoca vitulina)

    PubMed Central

    Weingartner, Gundula M.; Thornton, Sheila J.; Andrews, Russel D.; Enstipp, Manfred R.; Barts, Agnieszka D.; Hochachka, Peter W.

    2012-01-01

    Many phocid seals are expert divers that remain submerged longer than expected based on estimates of oxygen storage and utilization. This discrepancy is most likely due to an overestimation of diving metabolic rate. During diving, a selective redistribution of blood flow occurs, which may result in reduced metabolism in the hypoperfused tissues and a possible decline in whole-body metabolism to below the resting level (hypometabolism). Thyroid hormones are crucial in regulation of energy metabolism in vertebrates and therefore their control might be an important part of achieving a hypometabolic state during diving. To investigate the effect of thyroid hormones on diving physiology of phocid seals, we measured oxygen consumption, heart rate, and post-dive lactate concentrations in five harbor seals (Phoca vitulina) conducting 5 min dives on command, in both euthyroid and experimentally induced hyperthyroid states. Oxygen consumption during diving was significantly reduced (by 25%) in both euthyroid and hyperthyroid states, confirming that metabolic rate during diving falls below resting levels. Hyperthyroidism increased oxygen consumption (by 7–8%) when resting in water and during diving, compared with the euthyroid state, illustrating the marked effect of thyroid hormones on metabolic rate. Consequently, post-dive lactate concentrations were significantly increased in the hyperthyroid state, suggesting that the greater oxygen consumption rates forced seals to make increased use of anaerobic metabolic pathways. During diving, hyperthyroid seals also exhibited a more profound decline in heart rate than seals in the euthyroid state, indicating that these seals were pushed toward their aerobic limit and required a more pronounced cardiovascular response. Our results demonstrate the powerful role of thyroid hormones in metabolic regulation and support the hypothesis that thyroid hormones play a role in modulating the at-sea metabolism of phocid seals. PMID:23060807

  5. Re-alimentation in harbor seal pups: effects on the somatotropic axis and growth rate.

    PubMed

    Richmond, Julie P; Norris, Tenaya; Zinn, Steven A

    2010-01-15

    The metabolic hormones, growth hormone (GH) and insulin-like growth factor (IGF)-I, together with IGF binding proteins (IGFBP), have been well studied in domestic species and are the primary components of the somatotropic axis. This hormone axis is responsive to nutrient intake, associated with growth rate, and accretion of protein and adipose. However, this relationship has not been evaluated in species that rely heavily on adipose stores for survival, such as pinnipeds. The primary objectives of this research were to investigate the response of the somatotropic axis to reduced nutrient intake and re-alimentation in rehabilitated harbor seal pups, and to assess if these hormones are related to nutritional status and growth rate in harbor seals. Stranded harbor seal pups (n=24) arrived at the rehabilitation facility very thin after fasting for several days (nutritional nadir). Throughout rehabilitation nutrient intake increased and pups gained mass and body condition. Concentrations of GH and IGFBP-2 decreased with re-alimentation, while IGF-I and IGFBP-3 concentrations increased. Overall, GH and IGFBP-2 were negatively associated and IGF-I and IGFBP-3 were positively associated with growth rate and increased body condition of harbor sea pups. Further, the magnitude of the growth response was related to the magnitude in response of the somatotropic axis to varied levels of intake. These data suggest that multiple components of the somatotropic axis may be used to assess the energy status of individuals and may also provide information on the level of feed intake that is predictive of growth rate.

  6. Spatio-temporal Variation in Glacier Ice as Habitat for Harbor Seals in an Alaskan Tidewater Glacier Fjord

    NASA Astrophysics Data System (ADS)

    Womble, J. N.; McNabb, R. W.; Gens, R.; Prakash, A.

    2015-12-01

    Some of the largest aggregations of harbor seals (Phoca vitulina richardii) in Alaska occur in tidewater glacier fjords where seals rest upon icebergs that are calved from tidewater glaciers into the marine environment. The distribution, amount, and size of floating ice in fjords are likely important factors influencing the spatial distribution and abundance of harbor seals; however, fine-scale characteristics of ice habitat that are used by seals have not been quantified using automated methods. We quantified the seasonal changes in ice habitat for harbor seals in Johns Hopkins Inlet, a tidewater glacier fjord in Glacier Bay National Park, Alaska, using aerial photography, object-based image analysis, and spatial models. Aerial photographic surveys (n = 53) were conducted of seals and ice during the whelping (June) and molting (August) seasons from 2007-2014. Surveys were flown along a grid of 12 transects and high-resolution digital photos were taken directly under the plane using a vertically aimed camera. Seal abundance and spatial distribution was consistently higher during June (range: 1,672-4,340) than August (range: 1,075-2,582) and corresponded to the spatial distribution and amount of ice. Preliminary analyses from 2007 suggest that the average percent of icebergs (ice ≥ than 1.6m2) and brash ice (ice < 1.6m2) per scene were greater in June (icebergs: 1.8% ± 1.6%; brash ice: 43.8% ± 38.9%) than August (icebergs: 0.2% ± 0.7%; brash ice; 15.8% ± 26.4%). Iceberg angularity (an index of iceberg shape) was also greater in June (1.7 ± 0.9) than August (0.9 ± 0.9). Potential factors that may influence the spatio-temporal variation in ice habitat for harbor seals in tidewater glacier fjords include frontal ablation rates of glaciers, fjord circulation, and local winds. Harbor seals exhibit high seasonal fidelity to tidewater glacier fjords, thus understanding the relationships between glacier dynamics and harbor seal distribution will be critical for

  7. Digestive constraints on an aquatic carnivore: effects of feeding frequency and prey composition on harbor seals.

    PubMed

    Trumble, S J; Barboza, P S; Castellini, M A

    2003-08-01

    We hypothesized that increased feeding frequency in captive harbor seals would increase nutrient loads and thus reduce retention time and the digestive efficiency of natural prey. We measured daily feed intake and excretion during 6 feeding trials and fed herring (49% lipid), pollock (22% lipid) or an equal mix of each diet over 24 months. Animals were accustomed to feeding at either high or low frequency. Body mass and intake did not vary with season. Although mean retention times were similar between diets and feeding frequencies, solute and particulate digesta markers separated at high feeding frequency. Consistent dry matter digestibility resulted in greater gut fill from pollock than from herring. Digestible energy intakes from pollock were approximately 25% greater than from either herring or the mixed diet. Lipid digestibility of herring declined from 90% to 50% when lipid intake exceeded 60 g kg(-0.75) day(-1). Our hypothesis of a trade-off between intake and digestion was not supported for protein but was supported for lipid. Results of this study imply that a flexible digestive system for harbor seals can compensate for ingesting prey of lower energy density by increasing gut fill and enhancing protein and lipid assimilation, to sustain digestible energy intake.

  8. Chemical and biological pollution contribute to the immunological profiles of free-ranging harbor seals.

    PubMed

    Mos, Lizzy; Morsey, Brenda; Jeffries, Steven J; Yunker, Mark B; Raverty, Stephen; De Guise, Sylvain; Ross, Peter S

    2006-12-01

    Polychlorinated biphenyls and other persistent organic pollutants have been associated with immunotoxicity and outbreaks of (infectious) disease in marine mammals by rendering them vulnerable to infection by pathogens such as viruses and bacteria. In an immunotoxicological study of free-ranging harbor seals (Phoca vitulina), we obtained samples of blood and blubber from seal pups that were live-captured from two remote and two near-urban sites in British Columbia, Canada, and Washington state, USA. Using these samples, we quantified hematology, innate immune function, adaptive immune function, and polychlorinated biphenyl accumulation. While controlling for confounding factors (age, sex, and condition), univariate correlations between phagocytosis (r2 = 0.30, p = 0.002), respiratory burst (r2 =0.45, p= 0.000), T-lymphocyte function (r2 = 0.16, p = 0.028), lymphocyte signaling (r2 = 0.17, p = 0.025), and lymphocyte counts (r2 = 0.29, p = 0.002), and polychlorinated biphenyl concentrations suggested chemical-associated immunotoxicity. Principal component analysis of immunological endpoints provided additional evidence of immunotoxic effects in seals. However, principal component analysis also identified a noncontaminant-related factor by distinguishing between seals inhabiting urban versus remote sites, with results being consistent with increased pathogen exposure. Elevated fecal coliform concentrations in water, and observations of terrestrial spill-over pathogens in local seals, further support the notion of biological pollution at these sites. Although our study highlights the role that environmental contaminants might play in rendering marine mammal populations vulnerable to disease through immunotoxicity, it also suggests that biological pollution represents an emerging conservation concern.

  9. Comparative analysis of the fecal bacterial community of five harbor seals (Phoca vitulina).

    PubMed

    Numberger, Daniela; Herlemann, Daniel P R; Jürgens, Klaus; Dehnhardt, Guido; Schulz-Vogt, Heide

    2016-10-01

    The gut microbiota has many beneficial effects on host metabolism and health, and its composition is determined by numerous factors. It is also assumed that there was a co-evolution of mammals and the bacteria inhabiting their gut. Current knowledge of the mammalian gut microbiota mainly derives from studies on humans and terrestrial animals, whereas those on marine mammals are sparse. However, they could provide additional information on influencing factors, such as the role of diet and co-evolution with the host. In this study, we investigated and compared the bacterial diversity in the feces of five male harbor seals (Phoca vitulina). Because this small population included two half-brother pairs, each sharing a common father, it allowed an evaluation of the impact of host relatedness or genetic similarity on the gut microbial community. Fresh feces obtained from the seals by an enema were analyzed by fluorescence in situ hybridization and amplicon sequencing of 16S rRNA genes. The results showed that the bacterial communities in the seals' feces mainly consisted of the phyla Firmicutes (19-43%), Bacteroidetes (22-36%), Fusobacteria (18-32%), and Proteobacteria (5-17%) . Twenty-one bacterial members present in the fecal samples of the five seals contributed an average relative abundance of 93.7 + 8.7% of the total fecal microbial community. Contrary to all expectations based on previous studies a comparison of the fecal community between individual seals showed a higher similarity between unrelated than related individuals.

  10. Feeding Kinematics, Suction, and Hydraulic Jetting Performance of Harbor Seals (Phoca vitulina)

    PubMed Central

    Marshall, Christopher D.; Wieskotten, Sven; Hanke, Wolf; Hanke, Frederike D.; Marsh, Alyssa; Kot, Brian; Dehnhardt, Guido

    2014-01-01

    The feeding kinematics, suction and hydraulic jetting capabilities of captive harbor seals (Phoca vitulina) were characterized during controlled feeding trials. Feeding trials were conducted using a feeding apparatus that allowed a choice between biting and suction, but also presented food that could be ingested only by suction. Subambient pressure exerted during suction feeding behaviors was directly measured using pressure transducers. The mean feeding cycle duration for suction-feeding events was significantly shorter (0.15±0.09 s; P<0.01) than biting feeding events (0.18±0.08 s). Subjects feeding in-water used both a suction and a biting feeding mode. Suction was the favored feeding mode (84% of all feeding events) compared to biting, but biting comprised 16% of feeding events. In addition, seals occasionally alternated suction with hydraulic jetting, or used hydraulic jetting independently, to remove fish from the apparatus. Suction and biting feeding modes were kinematically distinct regardless of feeding location (in-water vs. on-land). Suction was characterized by a significantly smaller gape (1.3±0.23 cm; P<0.001) and gape angle (12.9±2.02°), pursing of the rostral lips to form a circular aperture, and pursing of the lateral lips to occlude lateral gape. Biting was characterized by a large gape (3.63±0.21 cm) and gape angle (28.8±1.80°; P<0.001) and lip curling to expose teeth. The maximum subambient pressure recorded was 48.8 kPa. In addition, harbor seals were able to jet water at food items using suprambient pressure, also known as hydraulic jetting. The maximum hydraulic jetting force recorded was 53.9 kPa. Suction and hydraulic jetting where employed 90.5% and 9.5%, respectively, during underwater feeding events. Harbor seals displayed a wide repertoire of behaviorally flexible feeding strategies to ingest fish from the feeding apparatus. Such flexibility of feeding strategies and biomechanics likely forms the basis of their opportunistic

  11. In Vitro Exposure of Harbor Seal Immune Cells to Aroclor 1260 Alters Phocine Distemper Virus Replication.

    PubMed

    Bogomolni, Andrea; Frasca, Salvatore; Levin, Milton; Matassa, Keith; Nielsen, Ole; Waring, Gordon; De Guise, Sylvain

    2016-01-01

    In the last 30 years, several large-scale marine mammal mortality events have occurred, often in close association with highly polluted regions, leading to suspicions that contaminant-induced immunosuppression contributed to these epizootics. Some of these recent events also identified morbillivirus as a cause of or contributor to death. The role of contaminant exposures regarding morbillivirus mortality is still unclear. The results of this study aimed to address the potential for a mixture of polychlorinated biphenyls (PCBs), specifically Aroclor 1260, to alter harbor seal T-lymphocyte proliferation and to assess if exposure resulted in increased likelihood of phocine distemper virus (PDV USA 2006) to infect susceptible seals in an in vitro system. Exposure of peripheral blood mononuclear cells to Aroclor 1260 did not significantly alter lymphocyte proliferation (1, 5, 10, and 20 ppm). However, using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), lymphocytes exposed to 20 ppm Aroclor 1260 exhibited a significant decrease in PDV replication at day 7 and a significant increase at day 11 compared with unexposed control cells. Similar and significant differences were apparent on exposure to Aroclor 1260 in monocytes and supernatant. The results here indicate that in harbor seals, Aroclor 1260 exposure results in a decrease in virus early during infection and an increase during late infection. The consequences of this contaminant-induced infection pattern in a highly susceptible host could result in a greater potential for systemic infection with greater viral load, which could explain the correlative findings seen in wild populations exposed to a range of persistent contaminants that suffer from morbillivirus epizootics.

  12. Factors Affecting Haul-Out Behavior of Harbor Seals (Phoca vitulina) in Tidewater Glacier Inlets in Alaska: Can Tourism Vessels and Seals Coexist?

    PubMed

    Blundell, Gail M; Pendleton, Grey W

    2015-01-01

    Large numbers of harbor seals (Phoca vitulina) use habitat in tidewater glaciers in Alaska for pupping, breeding, and molting. Glacial fjords are also popular tourist destinations; however, visitation by numerous vessels can result in disturbance of seals during critical life-history phases. We explored factors affecting haul-out behavior of harbor seals at a glacial site frequented by tourism vessels. In 2008-10, we deployed VHF transmitters on 107 seals in Endicott Arm, Alaska. We remotely monitored presence and haul-out behavior of tagged seals and documented vessel presence with time-lapse cameras. We evaluated the influence of environmental and physical factors on the probability of being hauled out, duration of haul-out bouts, and as factors associated with the start and end of a haulout. Location, season, hour, and interactions of location by year, season, hour, and sex significantly influenced haul-out probability, as did ice, weather, and vessels. Seals were more likely to be hauled out with greater ice availability during the middle of the day, and less likely to be hauled out if vessels were present. Cruise ships had the strongest negative effect; however, most vessel types negatively affected haul-out probability. Haul-out duration was longest in association with starting on incoming tides, clear skies, no precipitation, occurring in the middle of the day, and ending in the late afternoon or evening. End of haulouts was associated with increasing cloud cover, low ice availability, and vessel presence; large-sized tourism vessels or all-vessel-types combined were significant predictors of ending a haul-out bout. Probability of being hauled out was highest in June, during pupping season. Potential disturbances of harbor seals could be reduced, enabling longer resting times for seals and fewer interruptions for nursing pups, if vessels focused the majority of visits to glacial habitat to before or after the hours of 08:00-17:00 or, less optimally, 09:00-16:00.

  13. Metagenomic identification of a novel anellovirus in Pacific harbor seal (Phoca vitulina richardsii) lung samples and its detection in samples from multiple years.

    PubMed

    Ng, Terry Fei Fan; Wheeler, Elizabeth; Greig, Denise; Waltzek, Thomas B; Gulland, Frances; Breitbart, Mya

    2011-06-01

    To investigate viral pathogens potentially involved in a mortality event of 21 Pacific harbor seals (Phoca vitulina richardsii) in California in 2000, viral metagenomics was performed directly on lung samples from five individuals. Metagenomics revealed a novel seal anellovirus (SealAV), which clusters phylogenetically with anelloviruses from California sea lions and domestic cats. Using specific PCR, SealAV was identified in lung tissue from two of five animals involved in the 2000 mortality event, as well as one of 20 harbor seal samples examined post-mortem in 2008. The identification of SealAV in multiple years demonstrates that this virus is persistent in the harbor seal population. SealAV is the second anellovirus reported in the lungs of pinnipeds, suggesting that anellovirus infections may be common amongst marine mammals and that more research is needed to understand the roles of these viruses in marine mammal health and disease.

  14. Quantification of total mercury in liver and heart tissue of Harbor Seals (Phoca vitulina) from Alaska USA

    SciTech Connect

    Marino, Kady B.; Hoover-Miller, Anne; Conlon, Suzanne; Prewitt, Jill; O'Shea, Stephen K.

    2011-11-15

    This study quantified the Hg levels in the liver (n=98) and heart (n=43) tissues of Harbor Seals (Phoca vitulina) (n=102) harvested from Prince William Sound and Kodiak Island Alaska. Mercury tissue dry weight (dw) concentrations in the liver ranged from 1.7 to 393 ppm dw, and in the heart from 0.19 to 4.99 ppm dw. Results of this study indicate liver and heart tissues' Hg ppm dw concentrations significantly increase with age. Male Harbor Seals bioaccumulated Hg in both their liver and heart tissues at a significantly faster rate than females. The liver Hg bioaccumulation rates between the harvest locations Kodiak Island and Prince William Sound were not found to be significantly different. On adsorption Hg is transported throughout the Harbor Seal's body with the partition coefficient higher for the liver than the heart. No significant differences in the bio-distribution (liver:heart Hg ppm dw ratios (n=38)) values were found with respect to either age, sex or geographic harvest location. In this study the age at which Hg liver and heart bioaccumulation levels become significantly distinct in male and female Harbor Seals were identified through a Tukey's analysis. Of notably concern to human health was a male Harbor Seal's liver tissue harvested from Kodiak Island region. Mercury accumulation in this sample tissue was determined through a Q-test to be an outlier, having far higher Hg concentrarion (liver 392 Hg ppm dw) than the general population sampled. - Highlights: Black-Right-Pointing-Pointer Mercury accumulation in the liver and heart of seals exceed food safety guidelines. Black-Right-Pointing-Pointer Accumulation rate is greater in males than females with age. Black-Right-Pointing-Pointer Liver mercury accumulation is greater than in the heart tissues. Black-Right-Pointing-Pointer Mercury determination by USA EPA Method 7473 using thermal decomposition.

  15. 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.

  16. Xenobiotic and Immune-Relevant Molecular Biomarkers in Harbor Seals as Proxies for Pollutant Burden and Effects.

    PubMed

    Lehnert, Kristina; Ronnenberg, Katrin; Weijs, Liesbeth; Covaci, Adrian; Das, Krishna; Hellwig, Veronika; Siebert, Ursula

    2016-01-01

    Harbor seals are exposed to increasing pressure caused by anthropogenic activities in their marine environment. Persistent organic pollutants (POPs) and trace elements are hazardous contaminants that accumulate in tissues of harbor seals. POPs and trace elements can negatively affect the immune-system and have been reported, e.g., to increase susceptibility to viral infections in seals. Biomarkers of the xenobiotic metabolism, cytokines, and heat-shock protein as cell mediators of the immune-system were established to evaluate the impact of environmental stressors on harbor seals. Harbor seals (n = 54) were captured on sandbanks in the North Sea during 2009-2012. Health assessments, including hematology, were performed, and RNAlater blood samples were taken and analyzed using quantitative polymerase chain reaction. Normalized transcript copy numbers were correlated to hematology and POP concentration in blood and trace metals in blood and fur. A significant correlation between xenobiotic markers and contaminant burden was found. Significant interrelationships between markers and POP compounds, as well as with season, weight, and hematology values, indicate that biomarkers reflect pollutant exposure and effects. A significant relationship between cortisol levels and heat-shock protein expression was observed indicating stress experienced during restraint of the seals. Interleukin-10 transcription showed significant correlations with trace elements in fur pointing toward immune regulatory effects of metal exposure. The molecular markers prove to be an important noninvasive tool that reflects contaminant exposure and the impact of anthropogenic stressors in seal species. The connection between interleukin-2, xenobiotic markers, and pollutants may indicate immune suppression in animals exposed to contaminants with subsequent susceptibility to inflammatory disease.

  17. Post-Breeding Season Migrations of a Top Predator, the Harbor Seal (Phoca vitulina richardii), from a Marine Protected Area in Alaska

    PubMed Central

    Womble, Jamie N.; Gende, Scott M.

    2013-01-01

    Marine protected areas (MPAs) are increasingly being used as a conservation tool for highly mobile marine vertebrates and the focus is typically on protecting breeding areas where individuals are aggregated seasonally. Yet movements during the non-breeding season can overlap with threats that may be equally as important to population dynamics. Thus understanding habitat use and movements of species during the non-breeding periods is critical for conservation. Glacier Bay National Park, Alaska, is one of the largest marine mammal protected areas in the world and has the only enforceable protection measures for reducing disturbance to harbor seals in the United States. Yet harbor seals have declined by up to 11.5%/year from 1992 to 2009. We used satellite-linked transmitters that were attached to 37 female harbor seals to quantify the post-breeding season migrations of seals and the amount of time that seals spent inside vs. outside of the MPA of Glacier Bay. Harbor seals traveled extensively beyond the boundaries of the MPA of Glacier Bay during the post-breeding season, encompassing an area (25,325 km2) significantly larger than that used by seals during the breeding season (8,125 km2). These movements included the longest migration yet recorded for a harbor seal (3,411 km) and extended use (up to 23 days) of pelagic areas by some seals. Although the collective utilization distribution of harbor seals during the post-breeding season was quite expansive, there was a substantial degree of individual variability in the percentage of days that seals spent in the MPA. Nevertheless, harbor seals demonstrated a high degree of inter-annual site fidelity (93%) to Glacier Bay the following breeding season. Our results highlight the importance of understanding the threats that seals may interact with outside of the boundaries of the MPA of Glacier Bay for understanding population dynamics of seals in Glacier Bay. PMID:23457468

  18. Brain Meta-Transcriptomics from Harbor Seals to Infer the Role of the Microbiome and Virome in a Stranding Event

    PubMed Central

    Rosales, Stephanie M.; Vega Thurber, Rebecca

    2015-01-01

    Marine diseases are becoming more frequent, and tools for identifying pathogens and disease reservoirs are needed to help prevent and mitigate epizootics. Meta-transcriptomics provides insights into disease etiology by cataloguing and comparing sequences from suspected pathogens. This method is a powerful approach to simultaneously evaluate both the viral and bacterial communities, but few studies have applied this technique in marine systems. In 2009 seven harbor seals, Phoca vitulina, stranded along the California coast from a similar brain disease of unknown cause of death (UCD). We evaluated the differences between the virome and microbiome of UCDs and harbor seals with known causes of death. Here we determined that UCD stranded animals had no viruses in their brain tissue. However, in the bacterial community, we identified Burkholderia and Coxiella burnetii as important pathogens associated with this stranding event. Burkholderia were 100% prevalent and ~2.8 log2 fold more abundant in the UCD animals. Further, while C. burnetii was found in only 35.7% of all samples, it was highly abundant (~94% of the total microbial community) in a single individual. In this harbor seal, C. burnetii showed high transcription rates of invading and translation genes, implicating it in the pathogenesis of this animal. Based on these data we propose that Burkholderia taxa and C. burnetii are potentially important opportunistic neurotropic pathogens in UCD stranded harbor seals. PMID:26630132

  19. Complete Genome Sequence of Phocine Distemper Virus Isolated from a Harbor Seal (Phoca vitulina) during the 1988 North Sea Epidemic

    PubMed Central

    de Vries, Rory D.; Verburgh, R. Joyce; van de Bildt, Marco W. G.; Osterhaus, Albert D. M. E.

    2013-01-01

    Phocine distemper virus (PDV) was identified as the cause of a large morbillivirus outbreak among harbor seals in the North Sea in 1988. PDV is a member of the family Paramyxoviridae, genus Morbillivirus. Until now, no full-genome sequence of PDV has been available. PMID:23814028

  20. Genome Sequence of Streptococcus phocae subsp. phocae Strain ATCC 51973T Isolated from a Harbor Seal (Phoca vitulina)

    PubMed Central

    Poblete-Morales, Matías

    2015-01-01

    Streptococcus phocae subsp. phocae is a pathogen that affects different pinniped and mammalian species. This announcement reports the genome sequence of the type strain ATCC 51973 isolated in Norway from clinical specimens of harbor seal (Phoca vitulina), revealing interesting genes related to possible virulence factors. PMID:26586875

  1. Brain Meta-Transcriptomics from Harbor Seals to Infer the Role of the Microbiome and Virome in a Stranding Event.

    PubMed

    Rosales, Stephanie M; Thurber, Rebecca Vega

    2015-01-01

    Marine diseases are becoming more frequent, and tools for identifying pathogens and disease reservoirs are needed to help prevent and mitigate epizootics. Meta-transcriptomics provides insights into disease etiology by cataloguing and comparing sequences from suspected pathogens. This method is a powerful approach to simultaneously evaluate both the viral and bacterial communities, but few studies have applied this technique in marine systems. In 2009 seven harbor seals, Phoca vitulina, stranded along the California coast from a similar brain disease of unknown cause of death (UCD). We evaluated the differences between the virome and microbiome of UCDs and harbor seals with known causes of death. Here we determined that UCD stranded animals had no viruses in their brain tissue. However, in the bacterial community, we identified Burkholderia and Coxiella burnetii as important pathogens associated with this stranding event. Burkholderia were 100% prevalent and ~2.8 log2 fold more abundant in the UCD animals. Further, while C. burnetii was found in only 35.7% of all samples, it was highly abundant (~94% of the total microbial community) in a single individual. In this harbor seal, C. burnetii showed high transcription rates of invading and translation genes, implicating it in the pathogenesis of this animal. Based on these data we propose that Burkholderia taxa and C. burnetii are potentially important opportunistic neurotropic pathogens in UCD stranded harbor seals.

  2. Hematology and serum chemistry comparisons between free-ranging and rehabilitated harbor seal (Phoca vitulina richardsi) pups.

    PubMed

    Lander, Michelle E; Harvey, James T; Gulland, Frances M

    2003-07-01

    The objectives of this study were to compare the hematology and serum chemistry values between free-ranging and stranded harbor seal (Phoca vitulina richardsi) pups and to ascertain how blood values of stranded pups changed during the rehabilitation process. Coincident with these comparisons, reference values were obtained for free-ranging pups. Stranded harbor seal pups (n = 28) recovered from areas between Pebble Beach and Moss Landing, California (USA) were admitted to The Marine Mammal Center, Sausalito, from March to May 1995, 1996, and 1998. Blood samples were collected from harbor seal pups before and after rehabilitation. As a control group, wild harbor seal pups were captured at Pebble Beach and Elkhorn Slough (n = 42) during the 1995, 1996, and 1998 pupping seasons. Mean eosinophil and calcium values of wild pups were significantly greater than those of newly admitted pups, whereas mean bands, aspartate aminotransferase, alanine aminotransferase, total bilirubin, and chloride values were significantly lower (P < or = 0.05). Mean neutrophil, band, lymphocyte, eosinophil, basophil, calcium, phosphorus, blood urea nitrogen, potassium, total protein, and globulin values of rehabilitated pups increased significantly after 2-3 mo in captivity, whereas, mean red blood cell, hemoglobin, hematocrit, cholesterol, and total bilirubin values decreased significantly (P < or = 0.05).

  3. GC/MS ANALYSIS OF PCB CONGENERS IN BLOOD OF THE HARBOR SEAL PHOCA VITULINA FROM SAN FRANCISCO BAY

    EPA Science Inventory

    Here we report a validated technique for quantifying up to 20 specific PCB congeners in 1-2 g samples of whole blood with a detection limit below 1 ng/g (ppb) wet weight. Specimens were analyzed from 14 harbor seals sampled in south San Francisco Bay, California during 1991-1992....

  4. Immune status and function in harbor seal pups during the course of rehabilitation.

    PubMed

    Frouin, H; Haulena, M; Akhurst, L M F; Raverty, S A; Ross, P S

    2013-09-01

    Routine hematological and serum chemistry parameters are important tools for the evaluation of health and the treatment of marine mammals admitted to rehabilitation centers. The evaluation of phagocytosis, oxidative burst and immunoglobulin G (IgG), as markers of immune system function, and haptoglobin (Hp), as a stress marker, were evaluated alongside routine hematology and chemistry as potentially informative diagnostic tools for marine mammal health assessments. Blood samples from harbor seal pups (Phoca vitulina) admitted to (n=46), and released from (n=28), the Vancouver Aquarium's Marine Mammal Rescue Center (VAMMRC) were collected (1) to perform routine and novel functional approaches to evaluate the health of pups at admission; (2) to determine how these parameters changed during the rehabilitation process; and (3) to generate baseline values for reference purposes. Sodium was the only blood parameter which differed between seal pups that survived and those that died, with the surviving pups exhibiting higher levels on admission diagnostics. Positive correlations between total protein concentrations, IgG and Hp levels were observed with globulin concentrations of seal pups. Changes in serum chemistry values between admission and release included a decrease in red blood cells (RBCs), glucose, bicarbonate, total bilirubin, γ-glutamyltransferase (GGT) levels, and an increase in mean cell volume (MCV), mean cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC), lymphocytes, eosinophils, urea, potassium, anion gap, calcium, phosphorus, total protein, albumin, globulin and osmolality levels. During the rehabilitation process, phagocytosis decreased, while Hp levels increased. Age and improved health appeared to underlie changes in these parameters during the rehabilitation period.

  5. Factors Affecting Haul-Out Behavior of Harbor Seals (Phoca vitulina) in Tidewater Glacier Inlets in Alaska: Can Tourism Vessels and Seals Coexist?

    PubMed Central

    2015-01-01

    Large numbers of harbor seals (Phoca vitulina) use habitat in tidewater glaciers in Alaska for pupping, breeding, and molting. Glacial fjords are also popular tourist destinations; however, visitation by numerous vessels can result in disturbance of seals during critical life-history phases. We explored factors affecting haul-out behavior of harbor seals at a glacial site frequented by tourism vessels. In 2008-10, we deployed VHF transmitters on 107 seals in Endicott Arm, Alaska. We remotely monitored presence and haul-out behavior of tagged seals and documented vessel presence with time-lapse cameras. We evaluated the influence of environmental and physical factors on the probability of being hauled out, duration of haul-out bouts, and as factors associated with the start and end of a haulout. Location, season, hour, and interactions of location by year, season, hour, and sex significantly influenced haul-out probability, as did ice, weather, and vessels. Seals were more likely to be hauled out with greater ice availability during the middle of the day, and less likely to be hauled out if vessels were present. Cruise ships had the strongest negative effect; however, most vessel types negatively affected haul-out probability. Haul-out duration was longest in association with starting on incoming tides, clear skies, no precipitation, occurring in the middle of the day, and ending in the late afternoon or evening. End of haulouts was associated with increasing cloud cover, low ice availability, and vessel presence; large-sized tourism vessels or all-vessel-types combined were significant predictors of ending a haul-out bout. Probability of being hauled out was highest in June, during pupping season. Potential disturbances of harbor seals could be reduced, enabling longer resting times for seals and fewer interruptions for nursing pups, if vessels focused the majority of visits to glacial habitat to before or after the hours of 08:00-17:00 or, less optimally, 09

  6. The effect of signal onset/offset envelope on underwater detection thresholds of a harbor seal (Phoca vitulina).

    PubMed

    Turnbull, S D; Terhune, J M

    1995-07-01

    The effects of signal onset/offset envelope on the underwater hearing thresholds of a harbor seal (Phoca vitulina) were measured. Pure-tone, 540-ms pulses at 2, 4, 8, and 16 kHz were presented as test signals. An ANOVA revealed that there were no significant differences between repeated threshold measures for abrupt onset/offset signal envelopes versus slow onset/offset signal envelopes [F = 4.380, d.f. = (1,18), p > 0.05]. Seal vocalizations which have an abrupt onset/offset may be serving a short-range communicative function by helping the listener determine the direction of a nearby sender.

  7. Parapoxvirus infection in harbor seals (Phoca vitulina) from the German North Sea.

    PubMed

    Müller, G; Gröters, S; Siebert, U; Rosenberger, T; Driver, J; König, M; Becher, P; Hetzel, U; Baumgärtner, W

    2003-07-01

    In the summer of 2000, proliferative lesions of the skin and oral mucosa were observed in 26 young harbor seals (Phoca vitulina) from a rehabilitation center in Schleswig-Holstein, Germany. Verrucose, roundish nodules, approximately 1-2 cm in diameter, were presented in the oral cavity, especially on the tongue. Some animals developed similarly sized spherical dermal elevations with ulceration on flippers, chest, neck, and perineum. Necropsy of one animal showed multifocal, verrucose nodules in the oral cavity and a mild tonsillitis. Histologically, the nodules were characterized by ballooning degeneration of the outer parts of the spiny layer and stratum granulosum, with large eosinophilic cytoplasmic inclusions and a perivascular to interstitial lymphohistiocytic infiltration accompanied by fibroblastic proliferation and neovascularization. Negative staining of mucosal tissue homogenates demonstrated parapoxvirus-like particles. The presence of parapoxvirus was confirmed by polymerase chain reaction, using primers specific for parapoxvirus of ungulates. By in situ hybridization, using a parapox-specific, digoxigenin-labeled DNA probe, abundant parapoxvirus DNA-positive epithelial cells were detected in the stratum granulosum and the outer parts of the spiny layer. There was no parapoxvirus-positive signal in the adjacent submucosa. Although DNA analysis revealed that the causative agent can clearly be distinct from terrestrial parapoxviruses, lesions resembled parapoxvirus infections in other terrestrial species, and the pattern of virus DNA distribution indicated a direct effect of the virus on keratinocytes. In contrast, changes in the corium may be considered an indirect response mediated by the virus or the immune system.

  8. A Comparative Morphometric Analysis of Three Cranial Nerves in Two Phocids: The Hooded Seal (Cystophora cristata) and the Harbor Seal (Phoca vitulina).

    PubMed

    Wohlert, Dennis; Kröger, Jürgen; Witt, Martin; Schmitt, Oliver; Wree, Andreas; Czech-Damal, Nicole; Siebert, Ursula; Folkow, Lars; Hanke, Frederike D

    2016-03-01

    While our knowledge about the senses of pinnipeds has increased over the last decades almost nothing is known about the organization of the neuroanatomical pathways. In a first approach to this field of research, we assessed the total number of myelinated axons of three cranial nerves (CNs) in the harbor (Phoca vitulina, Pv) and hooded seal (Cystophora cristata, Cc). Axons were counted in semithin sections of the nerves embedded in Epon and stained with toluidine blue. In both species, the highest axon number was found within the optic nerve (Pv 187,000 ± 8,000 axons, Cc 481,600 ± 1,300 axons). Generally, considering absolute axon numbers, far more axons were counted within the optic and trigmenial nerve (Pv 136,700 ± 2,500 axons, Cc 179,300 ± 6,900 axons) in hooded in comparison to harbor seals. The axon counts of the vestibulocochlear nerve are nearly identical for both species (Pv 87,100 ± 8,100 axons, Cc 86,600 ± 2,700 axons). However, when comparing cell density, the cell density is almost equal for all nerves for both species except for the optic nerve in which cell density was particularly higher than in the other nerves and higher in hooded in comparison to harbor seals. We here present the first comparative analysis of three CNs in two phocid seals. While the CNs of these closely related species share some general characteristics, pronounced differences in axon numbers/densities are apparent. These differences seem to reflect differences in e.g. size, habitat, and/or functional significance of the innervated sensory systems.

  9. INFECTIOUS DISEASE AND TOXICOLOGICAL MONITORING OF STRANDED PACIFIC HARBOR SEALS (PHOCA VITULINA RICHARDSI) IN COOK INLET AS SURROGATES FOR MONITORING ENDANGERED BELUGAS (DELPHINAPTERUS LEUCAS).

    PubMed

    Bauer, Kendra L; Goertz, Caroline E C; Belovarac, Jane A; Walton, Robert W; Dunn, J Lawrence; Tuomi, Pamela

    2016-09-01

      Pacific harbor seals ( Phoca vitulina richardsi) and belugas ( Delphinapterus leucas ) eat many of the same prey species, occupy the same geographic area, and demonstrate site fidelity in Cook Inlet, Alaska. Although most direct research involving the critically endangered belugas is currently prohibited, studying harbor seals may provide important information about this beluga population. In recent years, harbor seal populations in Alaska have declined for unknown reasons. As part of its stranding program, the Alaska SeaLife Center (ASLC) managed 59 cases of live and dead stranded harbor seals from Cook Inlet between 1997 and 2011. Animals were screened for a variety of diseases and contaminants of concern. Animals were negative by serology to the following diseases: avian influenza, canine distemper virus, dolphin morbillivirus, porpoise morbillivirus, Leptospira canicola, L. grippotyphosa, L. pomona, Neospora caninum , Sarcocystis neurona , and Toxoplasma gondii . Positive titers were found against Brucella spp., phocine distemper virus, seal herpesvirus-1, L. bratislava, L. hardjo, and L. icterohemorrhagiae. All titers were stable or declining except in one animal with an increasing titer for seal herpesvirus-1. Fecal pathogen screenings identified normal flora as well as stable or declining low levels of potentially pathogenic and opportunistic bacteria, though most were of little concern for seal health. In most animals, toxicology screening showed that the majority of tested contaminants were below detectable limits. The level of evidence of exposure to pathogens of concern was low in harbor seals. Although the infectious disease burden and contaminant levels in belugas in Cook Inlet cannot be definitively determined without direct testing, pathogen and contaminant exposure is expected to be similar to that found in harbor seals in this region, as the harbor seals and belugas share the habitat and food resources.

  10. Brain transcriptomes of harbor seals demonstrate gene expression patterns of animals undergoing a metabolic disease and a viral infection

    PubMed Central

    Vega Thurber, Rebecca L.

    2016-01-01

    Diseases of marine mammals can be difficult to diagnose because of their life history and protected status. Stranded marine mammals have been a particularly useful resource to discover and comprehend the diseases that plague these top predators. Additionally, advancements in high-throughput sequencing (HTS) has contributed to the discovery of novel pathogens in marine mammals. In this study, we use a combination of HTS and stranded harbor seals (Phoca vitulina) to better understand a known and unknown brain disease. To do this, we used transcriptomics to evaluate brain tissues from seven neonatal harbor seals that expired from an unknown cause of death (UCD) and compared them to four neonatal harbor seals that had confirmed phocine herpesvirus (PhV-1) infections in the brain. Comparing the two disease states we found that UCD animals showed a significant abundance of fatty acid metabolic transcripts in their brain tissue, thus we speculate that a fatty acid metabolic dysregulation contributed to the death of these animals. Furthermore, we were able to describe the response of four young harbor seals with PhV-1 infections in the brain. PhV-1 infected animals showed a significant ability to mount an innate and adaptive immune response, especially to combat viral infections. Our data also suggests that PhV-1 can hijack host pathways for DNA packaging and exocytosis. This is the first study to use transcriptomics in marine mammals to understand host and viral interactions and assess the death of stranded marine mammals with an unknown disease. Furthermore, we show the value of applying transcriptomics on stranded marine mammals for disease characterization. PMID:28028481

  11. Lesions and behavior associated with forced copulation of juvenile Pacific harbor seals (Phoca vitulina richardsi) by southern sea otters (Enhydra lutris nereis)

    USGS Publications Warehouse

    Harris, H.S.; Oates, S.C.; Staedler, M.M.; Tinker, M.T.; Jessup, David A.; Harvey, J.T.; Miller, M.A.

    2010-01-01

    Nineteen occurrences of interspecific sexual behavior between male southern sea otters (Enhydra lutris nereis) and juvenile Pacific harbor seals (Phoca vitulina richardsi) were reported in Monterey Bay, California, between 2000 and 2002. At least three different male sea otters were observed harassing, dragging, guarding, and copulating with harbor seals for up to 7 d postmortem. Carcasses of 15 juvenile harbor seals were recovered, and seven were necropsied in detail by a veterinary pathologist. Necropsy findings from two female sea otters that were recovered dead from male sea otters exhibiting similar behavior are also presented to facilitate a comparison of lesions. The most frequent lesions included superficial skin lacerations; hemorrhage around the nose, eyes, flippers, and perineum; and traumatic corneal erosions or ulcers. The harbor seals sustained severe genital trauma, ranging from vaginal perforation to vagino-cervical transection, and colorectal perforations as a result of penile penetration. One harbor seal developed severe pneumoperitoneum subsequent to vaginal perforation, which was also observed in both female sea otters and has been reported as a postcoital lesion in humans. This study represents the first description of lesions resulting from forced copulation of harbor seals by sea otters and is also the first report of pneumoperitoneum secondary to forced copulation in a nonhuman animal. Possible explanations for this behavior are discussed in the context of sea otter biology and population demographics.

  12. Underwater detection of tonal signals between 0.125 and 100 kHz by harbor seals (Phoca vitulina).

    PubMed

    Kastelein, Ronald A; Wensveen, Paul J; Hoek, Lean; Verboom, Willem C; Terhune, John M

    2009-02-01

    The underwater hearing sensitivities of two 1-year-old female harbor seals were quantified in a pool built for acoustic research, using a behavioral psychoacoustic technique. The animals were trained to respond when they detected an acoustic signal and not to respond when they did not (go/no-go response). Pure tones (0.125-0.25 kHz) and narrowband frequency modulated (tonal) signals (center frequencies 0.5-100 kHz) of 900 ms duration were tested. Thresholds at each frequency were measured using the up-down staircase method and defined as the stimulus level resulting in a 50% detection rate. The audiograms of the two seals did not differ statistically: both plots showed the typical mammalian U-shape, but with a wide and flat bottom. Maximum sensitivity (54 dB re 1 microPa, rms) occurred at 1 kHz. The frequency range of best hearing (within 10 dB of maximum sensitivity) was from 0.5 to 40 kHz (6(1/3) octaves). Higher hearing thresholds (indicating poorer sensitivity) were observed below 1 and above 40 kHz. Thresholds below 4 kHz were lower than those previously described for harbor seals, which demonstrates the importance of using quiet facilities, built specifically for acoustic research, for hearing studies in marine mammals. The results suggest that under unmasked conditions many anthropogenic noise sources and sounds from conspecifics are audible to harbor seals at greater ranges than formerly believed.

  13. Co-occurrence of Pacific sleeper sharks Somniosus pacificus and harbor seals Phoca vitulina in Glacier Bay

    USGS Publications Warehouse

    Taggart, S.J.; Andrews, A.G.; Mondragon, Jennifer; Mathews, E.A.

    2005-01-01

    We present evidence that Pacific sleeper sharks Somniosus pacificus co-occur with harbor seals Phoca vitulina in Glacier Bay, Alaska, and that these sharks scavenge or prey on marine mammals. In 2002, 415 stations were fished throughout Glacier Bay on a systematic sampling grid. Pacific sleeper sharks were caught at 3 of the 415 stations, and at one station a Pacific halibut Hippoglossus stenolepis was caught with a fresh bite, identified as the bite of a sleeper shark. All 3 sharks and the shark-bitten halibut were caught at stations near the mouth of Johns Hopkins Inlet, a glacial fjord with the highest concentration of seals in Glacier Bay. Using a bootstrap technique, we estimated the probability of sampling the sharks (and the shark-bitten halibut) in the vicinity of Johns Hopkins Inlet. If sharks were randomly distributed in Glacier Bay, the probability of sampling all 4 pots at the mouth of Johns Hopkins Inlet was very low (P = 0.00002). The highly non-random distribution of the sleeper sharks located near the largest harbor seal pupping and breeding colony in Glacier Bay suggests that these 2 species co-occur and may interact ecologically in or near Johns Hopkins Inlet.

  14. Geographic variation and acoustic structure of the underwater vocalization of harbor seal (Phoca vitulina) in Norway, Sweden and Scotland.

    PubMed

    Bjørgesaeter, Anders; Ugland, Karl Inne; Bjørge, Arne

    2004-10-01

    The male harbor seal (Phoca vitulina) produces broadband nonharmonic vocalizations underwater during the breeding season. In total, 120 vocalizations from six colonies were analyzed to provide a description of the acoustic structure and for the presence of geographic variation. The complex harbor seal vocalizations may be described by how the frequency bandwidth varies over time. An algorithm that identifies the boundaries between noise and signal from digital spectrograms was developed in order to extract a frequency bandwidth contour. The contours were used as inputs for multivariate analysis. The vocalizations' sound types (e.g., pulsed sound, whistle, and broadband nonharmonic sound) were determined by comparing the vocalizations' spectrographic representations with sound waves produced by known sound sources. Comparison between colonies revealed differences in the frequency contours, as well as some geographical variation in use of sound types. The vocal differences may reflect a limited exchange of individuals between the six colonies due to long distances and strong site fidelity. Geographically different vocal repertoires have potential for identifying discrete breeding colonies of harbor seals, but more information is needed on the nature and extent of early movements of young, the degree of learning, and the stability of the vocal repertoire. A characteristic feature of many vocalizations in this study was the presence of tonal-like introductory phrases that fit into the categories pulsed sound and whistles. The functions of these phrases are unknown but may be important in distance perception and localization of the sound source. The potential behavioral consequences of the observed variability may be indicative of adaptations to different environmental properties influencing determination of distance and direction and plausible different male mating tactics.

  15. Dynamics of Vibrio with virulence genes detected in Pacific harbor seals (Phoca vitulina richardii) off California: implications for marine mammal health.

    PubMed

    Hughes, Stephanie N; Greig, Denise J; Miller, Woutrina A; Byrne, Barbara A; Gulland, Frances M D; Harvey, James T

    2013-05-01

    Given their coastal site fidelity and opportunistic foraging behavior, harbor seals (Phoca vitulina) may serve as sentinels for coastal ecosystem health. Seals using urbanized coastal habitat can acquire enteric bacteria, including Vibrio that may affect their health. To understand Vibrio dynamics in seals, demographic and environmental factors were tested for predicting potentially virulent Vibrio in free-ranging and stranded Pacific harbor seals (Phoca vitulina richardii) off California. Vibrio prevalence did not vary with season and was greater in free-ranging seals (29 %, n = 319) compared with stranded seals (17 %, n = 189). Of the factors tested, location, turbidity, and/or salinity best predicted Vibrio prevalence in free-ranging seals. The relationship of environmental factors with Vibrio prevalence differed by location and may be related to oceanographic or terrestrial contributions to water quality. Vibrio parahaemolyticus, Vibrio alginolyticus, and Vibrio cholerae were observed in seals, with V. cholerae found almost exclusively in stranded pups and yearlings. Additionally, virulence genes (trh and tdh) were detected in V. parahaemolyticus isolates. Vibrio cholerae isolates lacked targeted virulence genes, but were hemolytic. Three out of four stranded pups with V. parahaemolyticus (trh+ and/or tdh+) died in rehabilitation, but the role of Vibrio in causing mortality is unclear, and Vibrio expression of virulence genes should be investigated. Considering that humans share the environment and food resources with seals, potentially virulent Vibrio observed in seals also may be of concern to human health.

  16. Association between lymphocyte proliferation and polychlorinated biphenyls in free-ranging harbor seal (Phoca vitulina) pups from British Columbia, Canada.

    PubMed

    Levin, Milton; De Guise, Sylvain; Ross, Peter S

    2005-05-01

    Recent pinniped die-offs have led to the speculation that persistent organic pollutants (POPs) are immunomodulatory, making individuals more susceptible to viral infections. Eighteen healthy harbor seal (Phoca vitulina) pups (aged 3-4 weeks) were live-captured from southern British Columbia, Canada, and maintained temporarily in captivity for an immunotoxicological assessment. The relationships between mitogen-induced peripheral blood lymphocyte proliferation and blubber concentrations of three major immunotoxic POP classes (the polychlorinated biphenyls [PCBs], polychlorinated dibenzo-p-dioxins [PCDDs], and the polychlorinated dibenzofurans [PCDFs]) were evaluated. A significant body weight-independent positive correlation was observed between both T-cell mitogen (phytohemagglutinin [PHA])- and B-cell mitogen (lipopolysaccharide [LPS])-induced lymphocyte proliferation and the blubber concentrations of total PCB. Best subset regression analysis revealed that total PCBs, and not total PCDD or total PCDF, explained 24 and 29% of the changes in both T-cell mitogen-and B-cell mitogen-induced lymphocyte proliferation, respectively. Further regression analysis performed on the PCB classes measured in this study showed that di-ortho PCBs accounted for 25 and 30% of the changes in both T-cell and B-cell lymphocyte proliferation, respectively. Results suggest that POPs, and PCBs in particular, are associated with changes in lymphocyte proliferation, something that could result in increased susceptibility to infections in harbor seal pups. Further research is needed to evaluate the relative roles of natural and contaminant-related influences on the immune system of marine mammals.

  17. APHAKIC PHACOEMULSIFICATION AND AUTOMATED ANTERIOR VITRECTOMY, AND POSTRETURN MONITORING OF A REHABILITATED HARBOR SEAL (PHOCA VITULINA RICHARDSI) PUP.

    PubMed

    Esson, Douglas W; Nollens, Hendrik H; Schmitt, Todd L; Fritz, Kevin J; Simeone, Claire A; Stewart, Brent S

    2015-09-01

    A female harbor seal pup rescued along the coast of San Diego on 13 June 2012 was diagnosed with bilateral mature cataracts, apparently congenital, in association with vitreal herniation in the anterior chamber of each eye. The cataracts were surgically removed on 1 August 2012 with single-port aphakic phacoemulsification and automated anterior vitrectomy. Postoperative monitoring during the next several weeks indicated that vision had been functionally repaired and that she could visually orient to and capture live fish in three different environments and in the presence of other animals. Consequently, we equipped the seal with a satellite-linked radio transmitter and returned her to the Pacific Ocean on 21 November 2012, and then monitored her movements until radio contact ended on 2 March 2013. She remained along the San Diego coast from 21 November until 5 December 2012 when she relocated to the Coronado Islands and remained there until 26 December. She then traveled directly to San Clemente Island and remained foraging in the near-shore kelp beds there through 2 March 2013, when radio contact ended. To our knowledge, this is the first published report of cataract treatment in a marine mammal using high-frequency ultrasound to emulsify the lenses followed by suction removal of the emulsified microfragments (i.e., phacoemulsification). Moreover, the rapid postoperative recovery of the seal and its quick acclimation, orientation, navigation, and foraging in marine habitats after return to the Pacific Ocean indicates that these surgical procedures can be safe and effective treatments for cataracts in seals, with substantially reduced postsurgical complications relative to other types of lens fragmentation and removal procedures.

  18. Harbor seals (Phoca vitulina) in British Columbia, Canada, and Washington State, USA, reveal a combination of local and global polychlorinated biphenyl, dioxin, and furan signals.

    PubMed

    Ross, Peter S; Jeffries, Steven J; Yunker, Mark B; Addison, Richard F; Ikonomou, Michael G; Calambokidis, John C

    2004-01-01

    The harbor seal (Phoca vitulina) can serve as a useful indicator of food web contamination by persistent organic pollutants (POPs) because of its high trophic level, wide distribution in temperate coastal waters of the Northern Hemisphere, and relative ease of capture. In 1996 through 1997, we live-captured 60 harbor seal pups from three regions, spanning remote (Queen Charlotte Strait, BC, Canada), moderately industrialized (Strait of Georgia, BC, Canada), and heavily industrialized (Puget Sound, WA, USA) marine basins straddling the Canada-United States border. Biopsy samples of blubber were taken and analyzed for congener-specific polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) by using high-resolution gas chromatography-high-resolution mass spectrometry. Harbor seals in Puget Sound were heavily contaminated with PCBs, whereas seals from the Strait of Georgia had relatively high concentrations of PCDDs and PCDFs. Pattern evaluation and principal components analysis suggested that proximity to sources influenced the mixture to which seals were exposed, with those inhabiting more remote areas being exposed to lighter PCB congeners (those with lower Henry's law constant and K(ow)) that disperse more readily through atmospheric and other processes. Total toxic equivalents to 2,3,7,8-tetrachlorodibenzo-p-dioxin for the PCBs, PCDDs, and PCDFs suggest that Puget Sound seals are at greatest risk for adverse health effects, and that PCBs represent the class of dioxinlike contaminants of greatest concern at all sites.

  19. Mycotic dermatitis in an Atlantic white-sided dolphin, a pygmy sperm whale, and two harbor seals.

    PubMed

    Frasca, S; Dunn, J L; Cooke, J C; Buck, J D

    1996-03-01

    An Atlantic white-sided dolphin (Lagenorhynchus acutus), a pygmy sperm whale (Kogia breviceps), 2 harbor seals (Phoca vitulina) developed raised, firm, erythematous, cutaneous nodules that were most prominent on their heads, trunks, and on the caudal portions of their bodies. Prior to the onset of the condition, all 4 animals may have been stressed by factors such as being stranded on a beach, being transported long distances, or being relocated locally. Microbial culturing of the lesions on multiple media yielded fungal isolates containing conidia characteristic of Fusarium spp. Hyphae consistent with those of an ascomycete were evident on histologic examination of lesions. In each treated animal, the dermatitis resolved 3 to 4 weeks after completing treatment with ketoconazole. Fusarium spp may be opportunistic invaders of the skin of marine mammals that have decreased immunocompetence or integumentary compromise.

  20. Analysis of blood gases, serum fat and serum protein: a new approach to estimate survival chances of stranded Harbor seal (Phoca vitulina) pups from the German North Sea

    PubMed Central

    2014-01-01

    Background Facing numerous challenges, such as illness, storms or human disturbance, some harbor seal (Phoca vitulina) pups lose contact to their dams and are found abandoned along the North Sea coast. In Schleswig-Holstein, pups with the prospect of surviving rehabilitation are admitted to the Seal Center Friedrichskoog. Despite elaborate clinical health assessments on admission, including differential hematology, in 2010, 17% of 108 admitted pups did not survive the first 20 days. The death rate during the years 2006 and 2009 varied between 9 and 19%. To broaden the spectrum of variables which could be predictive for survival, blood gas and serum analyses were performed for 99 pups using venous blood. Variables included total CO2, pH, partial CO2, HCO3–, base excess and anion gap as well as glucose, urea nitrogen, sodium, potassium and chloride. Moreover, total serum protein and fat (triglyceride) concentrations were measured for all pups on admission. Results Repeated measurements of 12 randomly selected individuals revealed a significant (p = 0.002) positive influence of time in rehabilitation on triglyceride concentrations. This trend probably shows the improvement of the pups’ nutritional status as a consequence of the shift from milk replacer formula to fish. No such positive influence was detected for total protein concentrations though. Hematologic values, including blood gases, were not predictive for survival. Conclusions For the first time blood gas values are reported in this study for a large sample size (N = 99) of seal pups (regardless of their health status). The ranges and medians calculated from the data can serve as a stepping stone towards the establishment of reference values for neonate harbor seals. However, future investigations on the development of blood gases in harbor seals with different health conditions and ages over time are necessary to allow for a better understanding of acid–base regulation in harbor seals. PMID:24490584

  1. Immunotoxic effects of single and combined pharmaceuticals exposure on a harbor seal (Phoca vitulina) B lymphoma cell line.

    PubMed

    Kleinert, Christine; Lacaze, Emilie; Mounier, Méryl; De Guise, Sylvain; Fournier, Michel

    2017-03-02

    The potential risk of pharmaceuticals in the environment to top-predators is still largely unknown. In this study, we assessed the immunotoxic effects of ten pharmaceuticals individually and as mixtures on a harbor seal (Phoca vitulina) B lymphoma cell line. A significant reduction in lymphocyte transformation was observed following an exposure to 12,500μg/L 17α-ethinyl estradiol and 25,000μg/L naproxen. Exposure to 12,500μg/L 17α-ethinyl estradiol decreased the percentage of cell in the G0/G1 phase of the cell cycle while increasing the percentage of cells in the S phase. Carbamazepine exposure increased the amount of cells in the G2/M phase. Binary mixtures showed synergistic effects in lymphocyte transformation, cell cycle and apoptosis assays. Concentrations inducing toxic effects in the cell line were similar to those affecting fish in previous studies. A reduction of functional activities of the immune system may lead to altered host resistance to pathogens in free-ranging pinnipeds.

  2. Polychlorinated biphenyls, DDT, polybrominated diphenyl ethers, and organic pesticides in United Kingdom harbor seals (Phoca vitulina)--mixed exposures and thyroid homeostasis.

    PubMed

    Hall, Ailsa J; Thomas, Gareth O

    2007-05-01

    Polychlorinated biphenyls, DDT and its metabolites, polybrominated diphenyl ethers, and selected organochlorine pesticide concentrations were measured in blubber samples from 60 free-living harbor seals in 2003 from five sites around the United Kingdom coast. Significant regional differences among contaminant levels were found, with seals on Islay and Jura (southwest Scotland) having the highest levels of polychlorinated biphenyls and seals in the Wash (eastern England) having the highest polybrominated diphenyl ether levels. Animals from the north and northeast of Scotland (Orkney and the Moray Firth) had the lowest levels of all the contaminant groups studied. Congener-specific profiles of polychlorinated biphenyls and polybrominated diphenyl ethers showed relatively higher levels of the lower chlorinated and brominated compounds at the more northerly sites, with the lowest total levels of both chemical groups. Significant positive relationships between blubber contaminants and total triiodothyronine (TT3) concentrations were found after controlling for the potential effects of confounding because of sex, mass, and season. Increased serum TT3 levels were significantly related to higher blubber contaminant concentrations in the following order: sum of all contaminants > polybrominated diphenyl ethers > polychlorinated biphenyls > DDT. Serum TT3 levels in the harbor seals with the highest exposures might be indicative of a T3 thyrotoxicosis, but without information on free T3 and circulating thyroid-stimulating hormone levels, it is difficult to determine the importance of this observation for the health of the individuals or populations. However, the mixture of contaminants to which United Kingdom harbor seals are exposed has changed over the last few decades, and the toxicological and epidemiological importance of adding the brominated compounds to the classical organochlorine and heavy metal mixture is not known.

  3. PCB-related alteration of thyroid hormones and thyroid hormone receptor gene expression in free-ranging harbor seals (Phoca vitulina).

    PubMed

    Tabuchi, Maki; Veldhoen, Nik; Dangerfield, Neil; Jeffries, Steven; Helbing, Caren C; Ross, Peter S

    2006-07-01

    Persistent organic pollutants are environmental contaminants that, because of their lipophilic properties and long half-lives, bioaccumulate within aquatic food webs and often reach high concentrations in marine mammals, such as harbor seals (Phoca vitulina). Exposure to these contaminants has been associated with developmental abnormalities, immunotoxicity, and reproductive impairment in marine mammals and other high-trophic-level wildlife, mediated via a disruption of endocrine processes. The highly conserved thyroid hormones (THs) represent one vulnerable endocrine end point that is critical for metabolism, growth, and development in vertebrates. We characterized the relationship between contaminants and specific TH receptor (TR) gene expression in skin/blubber biopsy samples, as well as serum THs, from free-ranging harbor seal pups (n = 39) in British Columbia, Canada, and Washington State, USA. We observed a contaminant-related increase in blubber TR-alpha gene expression [total polychlorinated biphenyls (capital sigmaPCBs); r = 0.679; p < 0.001] and a concomitant decrease in circulating total thyroxine concentrations (capital sigmaPCBs; r = -0.711; p < 0.001) . Consistent with results observed in carefully controlled laboratory and captive feeding studies, our findings suggest that the TH system in harbor seals is highly sensitive to disruption by environmental contaminants. Such a disruption not only may lead to adverse effects on growth and development but also could have important ramifications for lipid metabolism and energetics in marine mammals.

  4. PCB-Related Alteration of Thyroid Hormones and Thyroid Hormone Receptor Gene Expression in Free-Ranging Harbor Seals (Phoca vitulina)

    PubMed Central

    Tabuchi, Maki; Veldhoen, Nik; Dangerfield, Neil; Jeffries, Steven; Helbing, Caren C.; Ross, Peter S.

    2006-01-01

    Persistent organic pollutants are environmental contaminants that, because of their lipophilic properties and long half-lives, bioaccumulate within aquatic food webs and often reach high concentrations in marine mammals, such as harbor seals (Phoca vitulina). Exposure to these contaminants has been associated with developmental abnormalities, immunotoxicity, and reproductive impairment in marine mammals and other high-trophic-level wildlife, mediated via a disruption of endocrine processes. The highly conserved thyroid hormones (THs) represent one vulnerable endocrine end point that is critical for metabolism, growth, and development in vertebrates. We characterized the relationship between contaminants and specific TH receptor (TR ) gene expression in skin/blubber biopsy samples, as well as serum THs, from free-ranging harbor seal pups (n = 39) in British Columbia, Canada, and Washington State, USA. We observed a contaminant-related increase in blubber TR-α gene expression [total polychlorinated biphenyls (∑PCBs); r = 0.679; p < 0.001] and a concomitant decrease in circulating total thyroxine concentrations (∑PCBs; r = −0.711; p < 0.001). Consistent with results observed in carefully controlled laboratory and captive feeding studies, our findings suggest that the TH system in harbor seals is highly sensitive to disruption by environmental contaminants. Such a disruption not only may lead to adverse effects on growth and development but also could have important ramifications for lipid metabolism and energetics in marine mammals. PMID:16835054

  5. Near-threshold equal-loudness contours for harbor seals (Phoca vitulina) derived from reaction times during underwater audiometry: a preliminary study.

    PubMed

    Kastelein, Ronald A; Wensveen, Paul J; Terhune, John M; de Jong, Christ A F

    2011-01-01

    Equal-loudness functions describe relationships between the frequencies of sounds and their perceived loudness. This pilot study investigated the possibility of deriving equal-loudness contours based on the assumption that sounds of equal perceived loudness elicit equal reaction times (RTs). During a psychoacoustic underwater hearing study, the responses of two young female harbor seals to tonal signals between 0.125 and 100 kHz were filmed. Frame-by-frame analysis was used to quantify RT (the time between the onset of the sound stimulus and the onset of movement of the seal away from the listening station). Near-threshold equal-latency contours, as surrogates for equal-loudness contours, were estimated from RT-level functions fitted to mean RT data. The closer the received sound pressure level was to the 50% detection hearing threshold, the more slowly the animals reacted to the signal (RT range: 188-982 ms). Equal-latency contours were calculated relative to the RTs shown by each seal at sound levels of 0, 10, and 20 dB above the detection threshold at 1 kHz. Fifty percent detection thresholds are obtained with well-trained subjects actively listening for faint familiar sounds. When calculating audibility ranges of sounds for harbor seals in nature, it may be appropriate to consider levels 20 dB above this threshold.

  6. Underwater hearing sensitivity of harbor seals (Phoca vitulina) for narrow noise bands between 0.2 and 80 kHz.

    PubMed

    Kastelein, Ronald A; Wensveen, Paul; Hoek, Lean; Terhune, John M

    2009-07-01

    The underwater hearing sensitivities of two 1.5-year-old female harbor seals were quantified in a quiet pool built specifically for acoustic research, by using a behavioral psychoacoustic technique. The animals were trained to respond when they detected an acoustic signal and not to respond when they did not ("go/no-go" response). Fourteen narrowband noise signals (1/3-octave bands but with some energy in adjacent bands), at 1/3-octave center frequencies of 0.2-80 kHz, and of 900 ms duration, were tested. Thresholds at each frequency were measured using the up-down staircase method and defined as the stimulus level resulting in a 50% detection rate. Between 0.5 and 40 kHz, the thresholds corresponded to a 1/3-octave band noise level of approximately 60 dB re 1 microPa (SD+/-3.0 dB). At lower frequencies, the thresholds increased to 66 dB re 1 microPa and at 80 kHz the thresholds rose to 114 dB re 1 microPa. The 1/3-octave noise band thresholds of the two seals did not differ from each other, or from the narrowband frequency-modulated tone thresholds at the same frequencies obtained a few months before for the same animals. These hearing threshold values can be used to calculate detection ranges of underwater calls and anthropogenic noises by harbor seals.

  7. Object-Based Image Classification of Floating Ice Used as Habitat for Harbor Seals in a Tidewater Glacier Fjord in Alaska

    NASA Astrophysics Data System (ADS)

    McNabb, R. W.; Womble, J. N.; Prakash, A.; Gens, R.; Ver Hoef, J.

    2014-12-01

    Tidewater glaciers play an important role in many landscape and ecosystem processes in fjords, terminating in the sea and calving icebergs and discharging meltwater directly into the ocean. Tidewater glaciers provide floating ice for use as habitat for harbor seals (Phoca vitulina richardii) for resting, pupping, nursing, molting, and avoiding predators. Tidewater glaciers are found in high concentrations in Southeast and Southcentral Alaska; currently, many of these glaciers are retreating or have stabilized in a retracted state, raising questions about the future availability of ice in these fjords as habitat for seals. Our primary objective is to investigate the relationship between harbor seal distribution and ice availability at an advancing tidewater glacier in Johns Hopkins Inlet, Glacier Bay National Park, Alaska. To this end, we use a combination of visible and infrared aerial photographs, object-based image analysis (OBIA), and statistical modeling techniques. We have developed a workflow to automate the processing of the imagery and the classification of the fjordscape (e.g., individual icebergs, brash ice, and open water), providing quantitative information on ice coverage as well as properties not typically found in traditional pixel-based classification techniques, such as block angularity and seal density across the fjord. Reflectance variation in the red channel of the optical images has proven to be the most important first-level criterion to separate open water from floating ice. This first-level criterion works well in areas without dense brash ice, but tends to misclassify dense brash ice as single icebergs. Isolating these large misclassified regions and applying a higher reflectance threshold as a second-level criterion helps to isolate individual ice blocks surrounded by dense brash ice. We present classification results from surveys taken during June and August, 2007-2013, as well as preliminary results from statistical modeling of the

  8. Trends in Stranding and By-Catch Rates of Gray and Harbor Seals along the Northeastern Coast of the United States: Evidence of Divergence in the Abundance of Two Sympatric Phocid Species?

    PubMed Central

    Johnston, David W.; Frungillo, Jaime; Smith, Ainsley; Moore, Katie; Sharp, Brian; Schuh, Janelle; Read, Andrew J.

    2015-01-01

    Harbor seals and gray seals are sympatric phocid pinnipeds found in coastal waters of the temperate and sub-Arctic North Atlantic. In the Northwest Atlantic, both species were depleted through a combination of subsistence hunts and government supported bounties, and are now re-occupying substantial portions of their original ranges. While both species appear to have recovered during the past 2 decades, our understanding of their population dynamics in US waters is incomplete. Here we describe trends in stranding and bycatch rates of harbor and gray seals in the North East United States (NEUS) over the past 16 years through an exploratory curve-fitting exercise and structural break-point analysis. Variability in gray seal strandings in Southern New England and bycatch in the Northeast Sink Gillnet Fishery were best described by fitting positive exponential and linear models, and exhibited rates of increase as high as 22%. In contrast, neither linear nor exponential models fit the oscillation of harbor seal strandings and bycatch over the study period. However, a breakpoint Chow test revealed that harbor seal strandings in the Cape Cod, Massachusetts region and harbor seal bycatch in the Northeast Sink Gillnet Fishery increased in the 1990s and then started declining in the early to mid-2000s. Our analysis indicates that ongoing variation in natural and anthropogenic mortality rates of harbor and gray seals in the NEUS is not synchronous, and likely represents diverging trends in abundance of these species as they assume new roles in the marine ecosystems of the region. PMID:26200461

  9. Trends in Stranding and By-Catch Rates of Gray and Harbor Seals along the Northeastern Coast of the United States: Evidence of Divergence in the Abundance of Two Sympatric Phocid Species?

    PubMed

    Johnston, David W; Frungillo, Jaime; Smith, Ainsley; Moore, Katie; Sharp, Brian; Schuh, Janelle; Read, Andrew J

    2015-01-01

    Harbor seals and gray seals are sympatric phocid pinnipeds found in coastal waters of the temperate and sub-Arctic North Atlantic. In the Northwest Atlantic, both species were depleted through a combination of subsistence hunts and government supported bounties, and are now re-occupying substantial portions of their original ranges. While both species appear to have recovered during the past 2 decades, our understanding of their population dynamics in US waters is incomplete. Here we describe trends in stranding and bycatch rates of harbor and gray seals in the North East United States (NEUS) over the past 16 years through an exploratory curve-fitting exercise and structural break-point analysis. Variability in gray seal strandings in Southern New England and bycatch in the Northeast Sink Gillnet Fishery were best described by fitting positive exponential and linear models, and exhibited rates of increase as high as 22%. In contrast, neither linear nor exponential models fit the oscillation of harbor seal strandings and bycatch over the study period. However, a breakpoint Chow test revealed that harbor seal strandings in the Cape Cod, Massachusetts region and harbor seal bycatch in the Northeast Sink Gillnet Fishery increased in the 1990s and then started declining in the early to mid-2000s. Our analysis indicates that ongoing variation in natural and anthropogenic mortality rates of harbor and gray seals in the NEUS is not synchronous, and likely represents diverging trends in abundance of these species as they assume new roles in the marine ecosystems of the region.

  10. Analysis of organochlorines in harbor seal (Phoca vitulina) tissue samples from Alaska using gas chromatography/ion trap mass spectrometry by an isotopic dilution technique.

    PubMed

    Wang, Dongli; Atkinson, Shannon; Hoover-Miller, Anne; Li, Qing X

    2005-01-01

    A gas chromatography/ion trap mass spectrometry (GC/ITMS) method was developed for the determination of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in harbor seal (Phoca vitulina) tissues. Tissue samples were homogenized, lyophilized and fortified with (13)C-PCBs 28, 123, 169 and 170, and then extracted with an accelerated solvent extractor with a mixture of hexane and methylene chloride (1:1, v/v). After lipid removal using a 40% H(2)SO(4)-modified silica gel column, all organochlorines were collected in one fraction and further fractionated with an activated carbon/silica gel (1:20) column into a first fraction containing OCPs, non-coplanar PCBs and (13)C-PCBs 28, 123 and 170, and a second containing PCNs, coplanar PCBs and (13)C-PCB 169. Prior to GC/MS/MS analysis, (13)C-PCB 169 was added into the first fraction as an injection standard and (13)C-PCB 170 into the second fraction to calibrate the recoveries of the fortified internal standards. This method can effectively eliminate matrix interferences, and has high selectivity and sensitivity. Recoveries averaged 45-86% for OCPs with relative standard deviations (RSDs) of 2-14%, 52-137% for PCBs with RSDs of 3-29% and 36-152% for PCNs with RSDs of 7-29% from lard and chicken heart samples, which were used as alternative matrices to harbor seal samples in recovery studies. The limits of detection for OCPs, PCBs and PCNs were 0.7-1.9, 1.5-8.9 and 0.5-10 pg/g dry weight, respectively. This method can be used to analyze OCPs, PCBs and PCNs in harbor seal blubber, liver and kidney samples.

  11. 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.

  12. Geography and stage of development affect persistent organic pollutants in stranded and wild-caught harbor seal pups from central California.

    PubMed

    Greig, Denise J; Ylitalo, Gina M; Wheeler, Elizabeth A; Boyd, Daryle; Gulland, Frances M D; Yanagida, Gladys K; Harvey, James T; Hall, Ailsa J

    2011-08-15

    Persistent organic pollutants have been associated with disease susceptibility and decreased immunity in marine mammals. Concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), polybrominated diphenyl ethers (PBDEs), chlordanes (CHLDs), and hexachlorocyclohexane isomers (HCHs) were evaluated in terms of stage of development and likely exposure routes (in utero, suckling, fasting) in the blubber of 202 stranded and wild-caught, primarily young of the year (n=177), harbor seals (Phoca vitulina) in the central California coast. This is the first report of HCH concentrations in the blubber of California seals. Lipid normalized concentrations ranged from 200 to 330,000 ng/g for sum PCBs, 320-1,500,000 ng/g for sum DDTs, 23-63,000 ng/g for sum PBDEs, 29-29,000 ng/g for sum CHLDs, and 2-780 ng/g for sum HCHs. The highest concentrations were observed in harbor seal pups that suckled in the wild and then lost mass during the post-weaning fast. Among the pups sampled in the wild and those released from rehabilitation, there were no differences in mass, blubber depth, or percent lipid although contaminant concentrations were significantly higher in the pups which nursed in the wild. When geographic differences were evaluated in a subset of newborn animals collected near their birth locations, the ratio of sum DDTs to sum PCBs was significantly greater in samples from an area with agricultural inputs (Monterey), than one with industrial inputs (San Francisco Bay). A principal components analysis distinguished between seals from San Francisco Bay and Monterey Bay based on specific PCB and PBDE congeners and DDT metabolites. These data illustrate the important influence of life stage, nutritional status, and location on blubber contaminant levels, and thus the need to consider these factors when interpreting single sample measurements in marine mammals.

  13. Exxon Valdez oil spill. State/federal natural resource damage assessment. Assessment of injury to harbor seals in Prince William Sound, Alaska, and adjacent areas following the Exxon Valdez oil spill. Marine mammal study number 5. Restoration study number 73. Final report

    SciTech Connect

    1994-05-01

    The goal of the project was to determine whether the Exxon Valdez oil spill (EVOS) had a measurable impact on harbor seals, Phocavitulina richardsi, in Prince William Sound (PWS) and adjacent areas. During the EVOS, harbor seals were exposed to oil both in the water and on land. The study was designed to investigate and quantify, as possible, the effects of oil and the disturbance associated with cleanup on distribution, abundance, and health of harbor seals in the affected area.

  14. Quantifying the Availability of Tidewater Glacial Ice as Habitat for Harbor Seals in a Tidewater Glacial Fjord in Alaska Using Object-Based Image Analysis of Airborne Visible Imagery

    NASA Astrophysics Data System (ADS)

    Prakash, A.; Haselwimmer, C. E.; Gens, R.; Womble, J. N.; Ver Hoef, J.

    2013-12-01

    Tidewater glaciers are prominent landscape features that play a significant role in landscape and ecosystem processes along the southeastern and southcentral coasts of Alaska. Tidewater glaciers calve large icebergs that serve as an important substrate for harbor seals (Phoca vitulina richardii) for resting, pupping, nursing young, molting, and avoiding predators. Many of the tidewater glaciers in Alaska are retreating, which may influence harbor seal populations. Our objectives are to investigate the relationship between ice conditions and harbor seal distributions, which are poorly understood, in John's Hopkins Inlet, Glacier Bay National Park, Alaska, using a combination of airborne remote sensing and statistical modeling techniques. We present an overview of some results from Object-Based Image Analysis (OBIA) for classification of a time series of very high spatial resolution (4 cm pixels) airborne imagery acquired over John's Hopkins Inlet during the harbor seal pupping season in June and during the molting season in August from 2007 - 2012. Using OBIA we have developed a workflow to automate processing of the large volumes (~1250 images/survey) of airborne visible imagery for 1) classification of ice products (e.g. percent ice cover, percent brash ice, percent ice bergs) at a range of scales, and 2) quantitative determination of ice morphological properties such as iceberg size, roundness, and texture that are not found in traditional per-pixel classification approaches. These ice classifications and morphological variables are then used in statistical models to assess relationships with harbor seal abundance and distribution. Ultimately, understanding these relationships may provide novel perspectives on the spatial and temporal variation of harbor seals in tidewater glacial fjords.

  15. 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.

  16. Hearing threshold shifts and recovery in harbor seals (Phoca vitulina) after octave-band noise exposure at 4 kHz.

    PubMed

    Kastelein, Ronald A; Gransier, Robin; Hoek, Lean; Macleod, Amy; Terhune, John M

    2012-10-01

    Safety criteria for underwater sounds from offshore pile driving are needed to protect marine mammals. As a first step toward understanding effects of impulsive sounds, two harbor seals were exposed to octave-band white noise centered at 4 kHz at three mean received sound pressure levels (SPLs; 124, 136, and 148 dB re 1 μPa) at up to six durations (7.5, 15, 30, 60, 120, and 240 min); mean received sound exposure level (SEL) range was 166-190 dB re 1 μPa(2) s. Hearing thresholds were determined before and after exposure. Temporary hearing threshold shifts (TTS) and subsequent recovery were quantified as changes in hearing thresholds at 1-4, 4-8, 8-12, 48, and 96 min after noise exposure in seal 01, and at 12-16, 16-20, 20-24, 60, and 108 min after exposure in seal 02. Maximum TTS (1-4 min after 120 min exposure to 148 dB re 1 μPa; 187 dB SEL) was 10 dB. Recovery occurred within ~60 min. Statistically significant TTSs (>2.5 dB) began to occur at SELs of ~170 (136 SPL, 60 min) and 178 dB re 1 μPa(2) s (148 SPL, 15 min). However, SEL is not an optimal predictor of TTS for long duration, low SPL continuous noise, as duration and SPL play unequal roles in determining induced TTS.

  17. Outcome of allogeneic hematopoietic stem cell transplantation in adult patients with acute myeloid leukemia harboring trisomy 8.

    PubMed

    Konuma, Takaaki; Kondo, Tadakazu; Yamashita, Takuya; Uchida, Naoyuki; Fukuda, Takahiro; Ozawa, Yukiyasu; Ohashi, Kazuteru; Ogawa, Hiroyasu; Kato, Chiaki; Takahashi, Satoshi; Kanamori, Heiwa; Eto, Tetsuya; Nakaseko, Chiaki; Kohno, Akio; Ichinohe, Tatsuo; Atsuta, Yoshiko; Takami, Akiyoshi; Yano, Shingo

    2017-03-01

    Trisomy 8 (+8) is one of the most common cytogenetic abnormalities in adult patients with acute myeloid leukemia (AML). However, the outcome of allogeneic hematopoietic stem cell transplantation (HSCT) in adult patients with AML harboring +8 remains unclear. To evaluate, the outcome and prognostic factors in patients with AML harboring +8 as the only chromosomal abnormality or in association with other abnormalities, we retrospectively analyzed the Japanese registration data of 631 adult patients with AML harboring +8 treated with allogeneic HSCT between 1990 and 2013. In total, 388 (61%) patients were not in remission at the time of HSCT. With a median follow-up of 38.5 months, the probability of overall survival and the cumulative incidence of relapse at 3 years were 40 and 34%, respectively. In the multivariate analysis, two or more additional cytogenetic abnormalities and not being in remission at the time of HSCT were significantly associated with a higher overall mortality and relapse. Nevertheless, no significant impact on the outcome was observed in cases with one cytogenetic abnormality in addition to +8. Although more than 60% of the patients received HSCT when not in remission, allogeneic HSCT offered a curative option for adult patients with AML harboring +8.

  18. The effect of diet and feeding level on survival and weight gain of hand-raised harbor seal pups (Phoca vitulina).

    PubMed

    MacRae, A M; Haulena, M; Fraser, D

    2011-01-01

    Hundreds of stranded harbor seals pups (Phoca vitulina) are brought to wildlife rescue centers every year. Typical hand-rearing diets include artificial milk-replacers and diets based on macerated fish fed via gavage, but weight gains are often low and mortality rates can be high. This study compared survival and weight gain of orphaned seal pups fed either artificial milk-replacer or fish-formula. Pups admitted to the facility in summer 2007 (n=145) and 2008 (n=98) were randomly assigned to one of two diets and fed by gavage until weaning. In 2007, pups fed milk-replacer gained more (43 ± 12 g/d) than those fed fish-formula (loss of 13 ± 6 g/d; P<0.002). In 2008, when intake was increased from 8 to 11% of body weight daily, weight gain improved for both diets but remained higher in pups fed milk-replacer (123 ± 12 g/d, vs. loss of 6 ± 8 g/day; P<0.001). Pup survival to weaning was significantly higher in 2008 than 2007 (P<0.001) and was higher for pups on milk-replacer compared with those on fish-formula (P<0.05). Survival was also correlated with body weight at admittance (P<0.001). Although neither diet achieved the weight gains recorded in mother-raised pups (400-800 g/d), the artificial milk-replacer was clearly more successful, and pups fared better in the second year of the study when intake was higher.

  19. 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.

  20. Assessment of injury to harbor seals in Prince William Sound, Alaska and adjacent areas following the Exxon Valdez oil spill. Marine mammal study number 5. (Restoration study number 73). Exxon Valdez oil spill, state/federal natural resource damage assessment final report

    SciTech Connect

    Frost, K.J.; Lowry, L.F.

    1994-05-01

    In the weeks following the Exxon Valdez oil spill (EVOS) harbor seals, Phocavitulina richardsi, swam through oil and inhaled aromatic hydrocarbons as they breathed at the air/water interface. Concentrations of fluorescent aromatic compounds in bile clearly indicated that most seals from oiled areas had been exposed to hydrocarbons. Before the EVOS, harbor seals in Prince William Sound were declining at an average annual rate of 12% in both oiled and unoiled areas. Aerial surveys in 1989 indicated a 43% decline at oiled sites versus an 11% decline at unoiled sites. By 1992, there were still 34% fewer seals at oiled sites than before the spill.

  1. Hair sampling location in harbor seals (Phoca vitulina) affects selenium and mercury concentrations: implications for study design of trace element determination in pinnipeds.

    PubMed

    McHuron, Elizabeth A; Harvey, James T; Castellini, J Margaret; O'Hara, Todd M

    2012-11-01

    Hair is used to determine trace elements exposure and status of pinnipeds because it is an excretory route for many elements and can be collected non-lethally. Despite increased use, there have been few studies on how sampling designs and procedures (e.g., hair type, collection site) affect results. The objective of this study was to determine whether concentrations of an essential (selenium; Se) and non-essential element (mercury; Hg) differed between hair samples collected from two body locations on harbor seals (Phoca vitulina). Concentrations of Se and total Hg (THg) differed between mid-dorsal midline and neck samples, and although the absolute differences were relatively small (Δ(absolute) Se = 0.69 μg g(-1), Δ(absolute) THg = 2.86 μg g(-1)), the relative differences were large (Δ(relative) Se = 49%, Δ(relative) THg = 17%). These differences highlight the need to standardize the collection site for trace element determination in pinnipeds.

  2. 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.

  3. 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.

  4. Immunohistochemical characterization of selected cell markers for the detection of hematopoietic cells in formalin-fixed, paraffin wax-embedded lymphoid tissues of harbor seals (Phoca vitulina) and walruses (Odobenus rosmarus rosmarus).

    PubMed

    Seibel, H; Stimmer, L; Siebert, U; Beineke, A

    2010-10-15

    To facilitate a detailed investigation of pinniped lymphoid organs, 30 monoclonal antibodies (mAb) as well as eight polyclonal antibodies (pAb) of different species specificities directed against cell antigens of the hematopoietic system were tested for immunohistochemical cross-reactivity on formalin-fixed, paraffin wax-embedded tissues of harbor seals (Phoca vitulina) and a walrus (Odobenus rosmarus rosmarus). Six monoclonal and eight polyclonal antibodies showed specific immunoreactivities. Lymphocytes were immunolabeled by an anti-CD3 pAb, anti-Foxp3 mAb and anti-CD79 alpha mAb, while plasma cell subpopulations were recognized by anti-IgA pAb, anti-IgG pAb and anti-IgM pAb as well as by anti-kappa- and anti-lambda light chain pAb. Cells of the histiocytic lineage were recognized by lysozyme-, myeloid/histiocyte antigen-, and CD68-specific markers. Furthermore, dendritic cell-like cells were detected by an anti-S100 protein pAb. The MHC class II antigen was labeled on the majority of immune cells of the harbor seal and walrus using a bovine mAb. Mast cells were stained by an anti-mast cell tryptase mAb. Thus, using these antibodies from various species, it is now possible to determine phenotypical changes in lymphoid organs and detect different leukocyte subsets involved in inflammatory responses in archived tissue samples of these pinniped species.

  5. 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.

  6. The effect of signal duration on the underwater hearing thresholds of two harbor seals (Phoca vitulina) for single tonal signals between 0.2 and 40 kHz.

    PubMed

    Kastelein, Ronald A; Hoek, Lean; Wensveen, Paul J; Terhune, John M; de Jong, Christ A F

    2010-02-01

    The underwater hearing sensitivities of two 2-year-old female harbor seals were quantified in a pool built for acoustic research by using a behavioral psycho-acoustic technique. The animals were trained only to respond when they detected an acoustic signal ("go/no-go" response). Detection thresholds were obtained for pure tone signals (frequencies: 0.2-40 kHz; durations: 0.5-5000 ms, depending on the frequency; 59 frequency-duration combinations). Detection thresholds were quantified by varying the signal amplitude by the 1-up, 1-down staircase method, and were defined as the stimulus levels, resulting in a 50% detection rate. The hearing thresholds of the two seals were similar for all frequencies except for 40 kHz, for which the thresholds differed by, on average, 3.7 dB. There was an inverse relationship between the time constant (tau), derived from an exponential model of temporal integration, and the frequency [log(tau)=2.86-0.94 log(f);tau in ms and f in kHz]. Similarly, the thresholds increased when the pulse was shorter than approximately 780 cycles (independent of the frequency). For pulses shorter than the integration time, the thresholds increased by 9-16 dB per decade reduction in the duration or number of cycles in the pulse. The results of this study suggest that most published hearing thresholds harbor seals are probably not absolute, as they were derived from signals with durations shorter than the time constants for those frequencies.

  7. 78 FR 29098 - Endangered and Threatened Wildlife; 90-Day Finding on a Petition To List Iliamna Lake Seals as a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-17

    ... Diversity (CBD) to list the harbor seals in Iliamna Lake, Alaska as a threatened or endangered species under... considered as part of the Bristol Bay harbor seal stock. CBD asserts that the harbor seals found in Iliamna... seals.'' CBD asserts that the seals in Iliamna Lake face the following threats: (1) Habitat...

  8. Molecular cloning and expression of leptin in gray and harbor seal blubber, bone marrow, and lung and its potential role in marine mammal respiratory physiology.

    PubMed

    Hammond, John A; Bennett, Kimberley A; Walton, Michael J; Hall, Ailsa J

    2005-08-01

    Leptin is a multifunctional hormone, produced predominantly in adipocytes. It regulates energy balance through its impact on appetite and fat metabolism, and its concentration indicates the size of body fat reserves. Leptin also plays a vital role in stretch-induced surfactant production during alveolar development in the fetus. The structure, expression pattern, and role of leptin have not previously been explored in marine mammals. Phocid seals undergo cyclical changes in body composition as a result of prolonged fasting and intensive foraging bouts and experience rapid, dramatic, and repeated changes in lung volume during diving. Here, we report the tissue-specific expression pattern of leptin in these animals. This is the first demonstration of leptin expression in the lung tissue of a mature mammal, in addition to its expression in the blubber and bone marrow, in common with other animals. We propose a role for leptin in seal pulmonary surfactant production, in addition to its likely role in long-term energy balance. We identify substitutions in the phocine leptin sequence in regions normally highly conserved between widely distinct vertebrate groups, and, using a purified seal leptin antiserum, we confirm the presence of the leptin protein in gray seal lung and serum fractions. Finally, we report the substantial inadequacies of using heterologous antibodies to measure leptin in unextracted gray seal serum.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. Infections in intensive care unit adult patients harboring multidrug-resistant Pseudomonas aeruginosa: implications for prevention and therapy.

    PubMed

    Borgatta, B; Lagunes, L; Imbiscuso, A T; Larrosa, M N; Lujàn, M; Rello, J

    2017-01-16

    The purpose of this paper was to report the burden and characteristics of infection by multidrug-resistant Pseudomonas aeruginosa (MDR-PA) in clinical samples from intensive care unit (ICU) adults, and to identify predictors. This was a retrospective observational study at four medical-surgical ICUs. The case cohort comprised adults with documented isolation of an MDR-PA strain from a clinical specimen during ICU stay. Multivariate analysis was performed to identify predictors for MDR-PA infection. During the study period, 5667 patients were admitted to the ICU and P. aeruginosa was isolated in 504 (8.8%). MDR-PA was identified in 142 clinical samples from 104 patients (20.6%); 62 (43.6%) of these samples appeared to be true infections. One hundred and eighteen (83.1%) isolates were susceptible only to amikacin and colistin, and 13 (9.2%) were susceptible only to colistin. Overall, the MIC50 to meropenem was 16 μg/mL and the MIC90 was >32 μg/mL, with 60.4% of respiratory samples being MIC >32 μg/mL to meropenem. Independent predictors for MDR-PA infection were fever/hypothermia [odds ratio (OR) 9.09], recent antipseudomonal cephalosporin therapy (OR 6.31), vasopressors at infection onset (OR 4.40), and PIRO (predisposition, infection, response, and organ dysfunction) score >2 (OR 2.06). This study provides novel information that may be of use for the clinical management of patients harboring MDR-PA and for the control of the spread of this organism.

  17. Disruption of Functional Connectivity in Clinically Normal Older Adults Harboring Amyloid Burden

    PubMed Central

    Hedden, Trey; Van Dijk, Koene R. A.; Becker, J. Alex; Mehta, Angel; Sperling, Reisa A.; Johnson, Keith A.; Buckner, Randy L.

    2009-01-01

    Amyloid deposition is present in 20–50% of nondemented older adults yet the functional consequences remain unclear. The current study found that amyloid accumulation is correlated with functional disruption of the default network as measured by intrinsic activity correlations. Clinically normal participants (n=38, aged 60–88) were characterized using [11C]-Pittsburgh Compound B (PiB) PET imaging to estimate fibrillar amyloid burden and, separately, underwent functional MRI (fMRI). The integrity of the default network was estimated by correlating rest-state fMRI time courses extracted from a priori regions including the posterior cingulate, lateral parietal, and medial prefrontal cortices. Clinically normal participants with high amyloid burden displayed significantly reduced functional correlations within the default network relative to participants with low amyloid burden. These reductions were also observed when amyloid burden was treated as a continuous, rather than a dichotomous, measure and when controlling for age and structural atrophy. Whole-brain analyses initiated by seeding the posterior cingulate cortex, a region of high amyloid burden in Alzheimer1s disease (AD), revealed significant disruption in the default network including functional disconnection of the hippocampal formation. PMID:19812343

  18. 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…

  19. 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

  20. Structural characterisation of Toll-like receptor 1 (TLR1) and Toll-like receptor 6 (TLR6) in elephant and harbor seals.

    PubMed

    Woodman, Sally; Gibson, Amanda J; García, Ana Rubio; Contreras, Guillermo Sanchez; Rossen, John W; Werling, Dirk; Offord, Victoria

    2016-01-01

    Pinnipeds are a diverse clade of semi-aquatic mammals, which act as key indicators of ecosystem health. Their transition from land to marine environments provides a complex microbial milieu, making them vulnerable to both aquatic and terrestrial pathogens, thereby contributing to pinniped population decline. Indeed, viral pathogens such as influenza A virus and phocine distemper virus (PDV) have been identified as the cause of several of these mass mortality events. Furthermore, bacterial infection with mammalian Brucella sp. and methicillin-resistant Staphylococcus aureus strains have also been observed in marine mammals, posing further risk to both co-habiting endangered species and public health. During these disease outbreaks, mortality rates have varied amongst different pinniped species. Analyses of innate immune receptors at the host-pathogen interface have previously identified variants which may drive these species-specific responses. Through a combination of both sequence- and structure-based methods, this study characterises members of the Toll-like receptor (TLR) 1 superfamily from both harbour and elephant seals, identifying variations which will help us to understand these species-specific innate immune responses, potentially aiding the development of specific vaccine-adjuvants for these species.

  1. 78 FR 57319 - Children's Online Privacy Protection Rule Safe Harbor Proposed Self-Regulatory Guidelines...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-18

    ... Harbor Proposed Self-Regulatory Guidelines; kidSAFE Seal Program Application for Safe Harbor AGENCY... the kidSAFE Seal Program (``kidSAFE''), owned and operated by Samet Privacy, LLC, under the safe... section below. Write ``kidSAFE Application for Safe Harbor, Project No. P-135418'' on your comment,...

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. [Pearl Harbor.

    ERIC Educational Resources Information Center

    Johnson, Jennifer, Ed.

    1992-01-01

    This issue of "Loblolly Magazine" was written in observance of the 50th anniversary of the U.S. entrance into World War II. The publication features interviews conducted by East Texas high school students with Clarence Otterman, one of the few survivors of the crew of the USS Arizona, which was bombed during the attack on Pearl Harbor,…

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Update on the prevalence of the hookworm, Uncinaria lucasi, in northern fur seals (Callorhinus ursinus) on St. Paul Island, Alaska, 2011.

    PubMed

    Lyons, Eugene T; Kuzmina, Tetiana A; Tolliver, Sharon C; Spraker, Terry R

    2012-09-01

    Prevalence of hookworms (Uncinaria lucasi Stiles, 1901) was determined in the northern fur seal (Callorhinus ursinus Linnaeus, 1758) on St. Paul Island (SPI), Alaska in July and August, 2011. Three of 61 (4.9%) dead pups harbored 1 to 13 adult hookworms each in their intestines. Parasitic larvae (L(3)) of hookworms were recovered from the blubber of 4 of 133 (3%) of subadult males (SAMs) examined. One parasitic L(3) was detected from each infected SAM. Adult U. lucasi (n = 3) were found in the intestine of 1 of 105 SAMs examined (0.95%). This is the first documented finding of adult U. lucasi in SAMs of the northern fur seals. Continued low prevalence of hookworms the last several years parallels the tremendous decline in the number of fur seals on SPI over a similar time period.

  17. 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.

  18. Confocal laser scanning microscopic observation on adult Schistosoma japonicum harbored in mice following treatment with single-dose mefloquine.

    PubMed

    Xiao, Shu-Hua; Sun, Jun; Xue, Jian

    2012-06-01

    The aim of the present study is to assess the mefloquine-induced alteration of adult Schistosoma japonicum using confocal laser scanning microscopy (CLSM). Eight out of ten mice infected with 60-80 S. japonicum cercariae for 35 days were treated orally with mefloquine at a single dose of 400 mg/kg. Four groups of two mice were killed at 24 h and 3, 7, and 14 days post-treatment, and schistosomes were collected by perfusion from the liver and mesenteric veins, fixed in 70% alcohol, stained with acid carmine, and examined by CLSM. Worms obtained from untreated mice served as controls. Twenty-four hours post-treatment, focal tegument of adult male and female worms, which composed of fine and short villus-like materials, became thicker and longer, or disorder arrangement, while the musculatures beneath the tegument revealed in focal and irregular swelling with various degrees. In the gut of male and female schistosomes, severe dilatation accompanied by swelling, collapse, and peeling of gut mucosa was universal. In the reproductive organs, no apparent alteration in the testis structure of male worms was seen, while in female worms, slight damage to the ovary included loose arrangement of mature ovary cells accompanied by some of them degenerated and collapsed. As to vitelline glands, severe damage, such as swelling, indistinction, fusion or collapse of vitelline cells, and apparent swelling of parenchymal tissues in vitelline gland lobules, was seen. Meanwhile, abnormal ova emerged in the uterus at this time point. Three to 7 days post-treatment, the damage to the worms aggravated either in extent or in severity along with time. In some focally swollen worm body, the parenchymal tissues revealed in severe swelling. In addition, a large piece of degenerated and necrotic parenchymal tissues emerged closed to the severe destructed oral or ventral sucker. In the gut of male and female worms, the major alterations manifested by focal collapse or peeling of mucosa, and

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 77 FR 38587 - Takes of Marine Mammals Incidental to Specified Activities; Harbor Activities Related to the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-28

    .../sars/po2011.pdf . California (southern) sea otters (Enhydra lutris nereis) are listed as threatened... California sea lions (Zalophus californianus), Pacific harbor seals (Phoca vitulina), and Northern elephant...; California sea lions; and Northern elephant seals by Level B harassment only. To date, we have issued...

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Temporal processing of low-frequency sounds by seals (L).

    PubMed

    Reichmuth, Colleen; Ghoul, Asila; Southall, Brandon L

    2012-10-01

    In a recent study, Kastelein et al. [(2010) J. Acoust. Soc. Am. 127, 1135-1145] reported auditory integration times for harbor seals (Phoca vitulina) exceeding 3000 ms for 200 Hz tonal signals. This finding is unexpected and potentially significant given that time constants measured in mammals for tones above 1 kHz are typically less than 500 ms. To further explore this result, the hearing of another harbor seal was measured in air and water for 200 Hz tones with durations of 500 and 2500 ms. Threshold comparisons, as well as reaction time measures, revealed no gain in audibility as signal duration increased above 500 ms.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. HERPESVIRUSES INCLUDING NOVEL GAMMAHERPESVIRUSES ARE WIDESPREAD AMONG PHOCID SEAL SPECIES IN CANADA.

    PubMed

    Bellehumeur, Christian; Nielsen, Ole; Measures, Lena; Harwood, Lois; Goldstein, Tracey; Boyle, Brian; Gagnon, Carl A

    2016-01-01

    Little is known about herpesviruses in Canadian pinnipeds. We measured prevalence of antibodies to herpesviruses in the sera from Canadian phocid seals by an indirect enzyme-linked immunosorbent assay. Wild harbor seals (Phoca vitulina) and captive harbor seals were positive for antibodies to Phocid herpesvirus 1 (PhoHV-1) at prevalences of 91% and 100%, respectively. Sera from wild hooded seals (Cystophora cristata), harp seals (Pagophilus groenlandica), and grey seals (Halichoerus grypus) were positive for antibodies to PhoHV-1 antigenically related herpesvirus antigens at 73%, 79%, and 96%, respectively. We isolated new herpesviruses in cell culture from two hunter-harvested ringed seals (Pusa hispida) in poor body condition from Ulukhaktok, Northwest Territories, Canada; one lethargic hooded seal from the St. Lawrence Estuary, Québec, Canada; and one captive, asymptomatic harp seal from the Magdalen Islands, Québec. Partial sequencing of the herpesvirus DNA polymerase gene revealed that all four virus isolates were closely related to PhoHV-2, a member of the Gammaherpesvirinae subfamily, with nucleotide similarity ranging between 92.8% and 95.3%. The new seal herpesviruses were genetically related to other known pinniped herpesviruses, such as PhoHV-1, Otariid herpesvirus 3, Hawaiian monk (Monachus schauinslandi) seal herpesvirus, and Phocid herpesvirus 5 with 47-48%, 55%, 77%, and 70-77% nucleotide similarities, respectively. The harp seal herpesvirus and both ringed seal herpesviruses were almost identical to each other, whereas the hooded seal herpesvirus was genetically different from the three others (92.8% nucleotide similarity), indicating detection of at least two novel seal herpesviruses. These findings are the first isolation, partial genome sequencing, and identification of seal gammaherpesviruses in three species of Canadian phocid seals; two species of which were suspected of exposure to one or more antigenically related herpesviruses based on

  13. Seasonal energetics of northern phocid seals.

    PubMed

    Ochoa-Acuña, Hugo G; McNab, Brian K; Miller, Edward H

    2009-03-01

    The metabolic rate of harp (Pagophilus groenlandicus), harbor (Phoca vitulina), and ringed seals (Pusa hispida) was measured at various temperatures in air and water to estimate basal metabolic rates (BMRs) in these species. The basal rate and body composition of three harp seals were also measured throughout the year to examine the extent to which they vary seasonally. Marine mammalian carnivores generally have BMRs that are over three times the rates expected from body mass in mammals generally, both as a response to a cold-water distribution and to carnivorous food habits with the basal rates of terrestrial carnivores averaging about 1.8 times the mean of mammals. Phocid seals, however, have basal rates of metabolism that are 30% lower than other marine carnivores. Captive seals undergo profound changes in body mass and food consumption throughout the year, and after accounting for changes in body mass, the lowest rate of food intake occurs in summer. Contrary to earlier observations, harp seals also have lower basal rates during summer than during winter, but the variation in BMR, relative to mass expectations, was not associated with changes in the size of fat deposits. The summer reduction in energy expenditure and food consumption correlated with a reduction in BMR. That is, changes in BMR account for a significant portion of the seasonal variation in energy expenditure in the harp seal. Changes in body mass of harp seals throughout the year were due not only to changes in the size of body fat deposits, but also to changes in lean body mass. These results suggest that bioenergetics models used to predict prey consumption by seals should include time-variant energy requirements.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Great Lakes Harbors Study

    DTIC Science & Technology

    1966-11-01

    Locally.assigned Library of Congress number: HE396 S25 U55 Nj 19. KEY WORDS (Continue on reverse side if necessary and identify by block number) 1. HARBORS 2... WATER TRANSPORTATION 3. ECONOMIC ANALYSIS 4. GREAT LJAKES - 20. ABSTRACT (Continue on ie.er.se side It necesaty nd identify by blocA number) Harbor...Scope 2 DESCRIPTION AND ECONOMIC DEVELOPMENT 3 Great Lakes-St. Lawrence Navigation System 2 4 Navigation Season 3 5 Water Levels 4 6 Tributary Area 6

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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).

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. HIV-positive nigerian adults harbor significantly higher serum lumefantrine levels than HIV-negative individuals seven days after treatment for Plasmodium falciparum infection.

    PubMed

    Chijioke-Nwauche, Ifeyinwa; van Wyk, Albert; Nwauche, Chijioke; Beshir, Khalid B; Kaur, Harparkash; Sutherland, Colin J

    2013-09-01

    Management of coinfection with malaria and HIV is a major challenge to public health in developing countries, and yet potential drug-drug interactions between antimalarial and antiviral regimens have not been adequately investigated in people with both infections. Each of the constituent components of artemether-lumefantrine, the first-line regimen for malaria treatment in Nigeria, and nevirapine, a major component of highly active antiretroviral therapy, are drugs metabolized by the cytochrome P450 3A4 isoenzyme system, which is also known to be induced by nevirapine. We examined potential interactions between lumefantrine and nevirapine in 68 HIV-positive adults, all of whom were diagnosed with asymptomatic Plasmodium falciparum infections by microscopy. Post hoc PCR analysis confirmed the presence of P. falciparum in only a minority of participants. Day 7 capillary blood levels of lumefantrine were significantly higher in HIV-positive participants than in 99 HIV-negative controls (P = 0.0011). Associations between day 7 levels of lumefantrine and risk of persistent parasitemia could not be evaluated due to inadequate power. Further investigations of the impact of nevirapine on in vivo malaria treatment outcomes in HIV-infected patients are thus needed.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Port and Harbor Security

    SciTech Connect

    Saito, T; Guthmuller, H; DeWeert, M

    2004-12-15

    Port and Harbor Security is a daunting task to which optics and photonics offers significant solutions. We are pleased to report that the 2005 Defense and Security Symposium (DSS, Orlando, FL) will include reports on active and passive photonic systems operating from both airborne and subsurface platforms. In addition to imaging techniques, there are various photonic applications, such as total internal reflection fluorescence (TIRF), which can be used to ''sniff'' for traces of explosives or contaminants in marine. These non-imaging technologies are beyond the scope of this article, but will also be represented at DSS 2005. We encourage colleagues to join our technical group to help us to make our ports and harbors safer and more secure.

  1. Pearl Harbor Biological Survey

    DTIC Science & Technology

    1974-08-30

    Scalloped Hammerhead Shark , Sphyma leuini. In Hawaii", Pacific Science, 25(2):133-144. 2.1-11 "Surveillance, Sewage and Surprises", Navy Action 󈨌...Some fish tagged in the harbor were caught off Sand Island; others were returned from the Honolulu fish markets. The hammerhead shark {Sphyma...MYLIOBATIDAE Scalloped hammerhead shark ; Mano kihlkihi Sphyma lewini after K, S 4 W (16130101) ELOPIDAE fit. Spotted eagle ray; Hihimanu AetobatuB

  2. 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.

  3. 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)

  4. 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.

  5. 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

  6. 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.

  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. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. Organochlorine contaminants in blubber of four seal species: integrating biomonitoring and specimen banking.

    PubMed

    Krahn, M M; Becker, P R; Tilbury, K L; Stein, J E

    1997-05-01

    Blubber samples from four Alaska seal species (bearded seal, Erignathus barbatus, harbor seal, Phoca vitulina, northern fur seal, Callorhinus ursinus, ringed seal, P. hispida) were collected for inclusion in the US National Biomonitoring Specimen Bank, as well as for immediate analysis as part of the contaminant monitoring component of the US National Marine Fisheries Service's Marine Mammal Health and Stranding Response Program. The blubber samples were analyzed for organochlorine (OC) contaminants (e.g., PCB congeners, pesticides, DDTs). Results for bearded and ringed seals from the Alaska Arctic revealed low blubber concentrations of OC contaminants. Harbor seals from Prince William Sound. Gulf of Alaska, had somewhat higher blubber concentrations of OC contaminants. In contrast, northern fur seals sampled from the Pribilof Islands had blubber concentrations of certain OC contaminants that were about an order of magnitude higher than those found in the other seal species. Differences in contaminant concentrations among the Alaska seals may be explained by differences in feeding habits and migratory patterns, age or gender did not appear to account for the differences observed. The highest concentrations of OCs were found in harbor seals stranded along the northwestern US mainland, which is consistent with higher concentrations of anthropogenic contaminants being found in urban coastal areas than in more remote Arctic environments. The integration of real-time contaminant monitoring with specimen banking provides important baseline data that can be used to plan and manage banking activities. This includes identifying appropriate specimens that are useful in assessing temporal trends and increasing the utility of the banked samples in assessing chemical contaminant accumulation and relationships to biological effects.

  6. 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.

  7. 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.

  8. 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.

  9. 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)

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Norovirus Infection in Harbor Porpoises

    PubMed Central

    Bodewes, Rogier; van Elk, Cornelis E.; van de Bildt, Marco; Getu, Sarah; Aron, Georgina I.; Verjans, Georges M.G.M.; Osterhaus, Albert D.M.E.; van den Brand, Judith M.A.; Kuiken, Thijs; Koopmans, Marion P.G.

    2017-01-01

    A norovirus was detected in harbor porpoises, a previously unknown host for norovirus. This norovirus had low similarity to any known norovirus. Viral RNA was detected primarily in intestinal tissue, and specific serum antibodies were detected in 8 (24%) of 34 harbor porpoises from the North Sea. PMID:27983498

  18. 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.

  19. Molecular Epidemiology of Seal Parvovirus, 1988–2014

    PubMed Central

    Bodewes, Rogier; Hapsari, Rebriarina; Rubio García, Ana; Sánchez Contreras, Guillermo J.; van de Bildt, Marco W. G.; de Graaf, Miranda; Kuiken, Thijs; Osterhaus, Albert D. M. E.

    2014-01-01

    A novel parvovirus was discovered recently in the brain of a harbor seal (Phoca vitulina) with chronic meningo-encephalitis. Phylogenetic analysis of this virus indicated that it belongs to the genus Erythroparvovirus, to which also human parvovirus B19 belongs. In the present study, the prevalence, genetic diversity and clinical relevance of seal parvovirus (SePV) infections was evaluated in both harbor and grey seals (Halichoerus grypus) that lived in Northwestern European coastal waters from 1988 to 2014. To this end, serum and tissue samples collected from seals were tested for the presence of seal parvovirus DNA by real-time PCR and the sequences of the partial NS gene and the complete VP2 gene of positive samples were determined. Seal parvovirus DNA was detected in nine (8%) of the spleen tissues tested and in one (0.5%) of the serum samples tested, including samples collected from seals that died in 1988. Sequence analysis of the partial NS and complete VP2 genes of nine SePV revealed multiple sites with nucleotide substitutions but only one amino acid change in the VP2 gene. Estimated nucleotide substitution rates per year were 2.00×10−4 for the partial NS gene and 1.15×10−4 for the complete VP2 gene. Most samples containing SePV DNA were co-infected with phocine herpesvirus 1 or PDV, so no conclusions could be drawn about the clinical impact of SePV infection alone. The present study is one of the few in which the mutation rates of parvoviruses were evaluated over a period of more than 20 years, especially in a wildlife population, providing additional insights into the genetic diversity of parvoviruses. PMID:25390639

  20. Molecular epidemiology of seal parvovirus, 1988-2014.

    PubMed

    Bodewes, Rogier; Hapsari, Rebriarina; Rubio García, Ana; Sánchez Contreras, Guillermo J; van de Bildt, Marco W G; de Graaf, Miranda; Kuiken, Thijs; Osterhaus, Albert D M E

    2014-01-01

    A novel parvovirus was discovered recently in the brain of a harbor seal (Phoca vitulina) with chronic meningo-encephalitis. Phylogenetic analysis of this virus indicated that it belongs to the genus Erythroparvovirus, to which also human parvovirus B19 belongs. In the present study, the prevalence, genetic diversity and clinical relevance of seal parvovirus (SePV) infections was evaluated in both harbor and grey seals (Halichoerus grypus) that lived in Northwestern European coastal waters from 1988 to 2014. To this end, serum and tissue samples collected from seals were tested for the presence of seal parvovirus DNA by real-time PCR and the sequences of the partial NS gene and the complete VP2 gene of positive samples were determined. Seal parvovirus DNA was detected in nine (8%) of the spleen tissues tested and in one (0.5%) of the serum samples tested, including samples collected from seals that died in 1988. Sequence analysis of the partial NS and complete VP2 genes of nine SePV revealed multiple sites with nucleotide substitutions but only one amino acid change in the VP2 gene. Estimated nucleotide substitution rates per year were 2.00 × 10(-4) for the partial NS gene and 1.15 × 10(-4) for the complete VP2 gene. Most samples containing SePV DNA were co-infected with phocine herpesvirus 1 or PDV, so no conclusions could be drawn about the clinical impact of SePV infection alone. The present study is one of the few in which the mutation rates of parvoviruses were evaluated over a period of more than 20 years, especially in a wildlife population, providing additional insights into the genetic diversity of parvoviruses.

  1. 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.

  2. Detection of Complex Sounds in Quiet Conditions by Seals and Sea Lions.

    PubMed

    Cunningham, Kane A; Southall, Brandon L; Reichmuth, Colleen

    2016-01-01

    To test how accurately baseline audiometric data predict detection of complex stimuli, absolute detection thresholds for frequency-modulated (FM), amplitude-modulated (AM), and harmonic stimuli were obtained for one Phoca vitulina (harbor seal) and one Zalophus californianus (California sea lion) at frequencies spanning the functional range of hearing. These thresholds were then compared with a priori predictions based on the tonal audiograms of these subjects. Predicted thresholds were accurate for most FM signals and for AM signals for the California sea lion. Predictions were unreliable for harmonic signals for both species and for AM signals for the harbor seal.

  3. 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.

  4. Gulf of Maine Seals - Populations, Problems and Priorities

    DTIC Science & Technology

    2010-06-01

    needs for future study. 9 Pinnipeds in the Gulf of Maine: Status, Issues and Management, 1995 In 1995 the New England Aquarium in Boston...warranted. Meeting on Harbor seals of the Northeast (U.S.) region, 2002 and 2004 In 2004, the Maritime Aquarium at Norwalk sponsored a one-day...M. L., and G. S. Stone (Editors). 1995. Pinniped populations in the Gulf of Maine: status, issues and management. New England Aquarium Aquatic Forum

  5. Brightness discrimination in the South African fur seal (Arctocephalus pusillus).

    PubMed

    Scholtyssek, C; Dehnhardt, G

    2013-05-24

    Underwater, the contrast between object and background is much larger reduced with increasing distance between object and observer than in air. For marine predators, such as pinnipeds, it would therefore be advantageous to possess a high sensitivity for brightness differences, since this would increase the distance at which prey can be detected visually. Few studies have examined the brightness discrimination thresholds of pinnipeds. Two studies with phocid seals have confirmed low brightness discrimination thresholds in pinnipeds whereas the threshold obtained for the South African fur seal seems to be twice as high as that of the phocids. However, the experiments with the South African fur seal have been conducted under inadequate conditions which likely resulted in an underestimation of the brightness discrimination ability of this species. The study at hand reinvestigated the brightness discrimination threshold of the South African fur seal under well controlled conditions. In a two alternative forced choice task, one fur seal was trained to indicate the position of the brighter of two gray discs presented on a black background on a monitor. The thresholds were determined for 11 standard intensities each tested against 8 lower comparison intensities. It was found that the fur seal was able to perceive brightness differences of 8-10%, which is better than the phocid species tested so far. For low standard intensities, however, the threshold increased which could to be due to a relative slow dark adaptation rate of the fur seal. The results are discussed in terms of the relevance of visual information for pinnipeds during foraging dives and are directly compared to the results obtained for the harbor seal which has been tested under the same conditions as the fur seal in a previous study.

  6. Genetics Home Reference: Floating-Harbor syndrome

    MedlinePlus

    ... Understand Genetics Home Health Conditions Floating-Harbor syndrome Floating-Harbor syndrome Enable Javascript to view the expand/ ... boxes. Download PDF Open All Close All Description Floating-Harbor syndrome is a disorder involving short stature, ...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. High-frequency hearing in seals and sea lions.

    PubMed

    Cunningham, Kane A; Reichmuth, Colleen

    2016-01-01

    Existing evidence suggests that some pinnipeds (seals, sea lions, and walruses) can detect underwater sound at frequencies well above the traditional high-frequency hearing limits for their species. This phenomenon, however, is not well studied: Sensitivity patterns at frequencies beyond traditional high-frequency limits are poorly resolved, and the nature of the auditory mechanism mediating hearing at these frequencies is unknown. In the first portion of this study, auditory sensitivity patterns in the 50-180 kHz range were measured for one California sea lion (Zalophus californianus), one harbor seal (Phoca vitulina), and one spotted seal (Phoca largha). Results show the presence of two distinct slope-regions at the high-frequency ends of the audiograms of all three subjects. The first region is characterized by a rapid decrease in sensitivity with increasing frequency-i.e. a steep slope-followed by a region of much less rapid sensitivity decrease-i.e. a shallower slope. In the second portion of this study, a masking experiment was conducted to investigate how the basilar membrane of a harbor seal subject responded to acoustic energy from a narrowband masking noise centered at 140 kHz. The measured masking pattern suggests that the initial, rapid decrease in sensitivity on the high-frequency end of the subject's audiogram is not due to cochlear constraints, as has been previously hypothesized, but rather to constraints on the conductive mechanism.

  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. Sediment toxicity in Savannah Harbor

    USGS Publications Warehouse

    Winger, P.V.; Lasier, P.J.

    1995-01-01

    Savannah Harbor, located near the mouth of the Savannah River, Georgia and South Carolina, is impacted by industrial and municipal effluents. Potential release of contaminants stored in harbor sediments through dredging and shipping operations requires that contaminated areas be identified for proper management of the system and protection of wildlife resources. During 1991, Hyalella azteca were exposed in 10-d static-renewal toxicity tests to pore-water and solid-phase sediment samples collected from 26 sites within Savannah Harbor. Pore-water toxicity was more pronounced than that for solidphase sediment. Toxicity and reduced leaf consumption demonstrated impaired sediment quality at specific sites within Savannah Harbor and Back River. Factors responsible for the decreased sediment quality were ammonia, alkalinity, and metal concentrations (cadmium, chromium, lead, molybdenum, and nickel). Elevated concentrations of metals and toxicities in Back River sediments indicated impacts from adjacent dredge-spoil areas.

  15. 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.

  16. 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.

  17. Histopathologic and immunocytochemical studies of distemper in harbor porpoises.

    PubMed

    Kennedy, S; Smyth, J A; Cush, P F; McAliskey, M; McCullough, S J; Rima, B K

    1991-01-01

    During 1988 thousands of harbor seals (Phoca vitulina) died in European seas as a result of morbillivirus infection. Six harbor porpoises (Phocoena phocoena) found stranded on the coast of Northern Ireland in late 1988 were submitted to our laboratory for necropsy. Pneumonia was the main necropsy finding in three of these animals. Microscopic lung lesions characterized by necrosis of bronchial and bronchiolar epithelium and infiltration of alveoli with leukocytes, lymphoid cells, macrophages, and multinucleate syncytia were seen in all six porpoises. Cytoplasmic and nuclear acidophilic inclusions characteristic of morbillivirus infection were common in bronchial and bronchiolar epithelial cells and in alveolar macrophages and syncytia. Brain alterations included degeneration and necrosis of neurons, microglial infiltration, and perivascular cuffing. There were cytoplasmic and nuclear acidophilic inclusions in many neurons. Immunoperoxidase staining of morbillivirus antigen was seen in many tissues including lung, brain, spleen, and urinary bladder. Alterations in our porpoises were similar to those seen in distemper in seals and many species of terrestrial mammals. Systemic viral disease has not previously been documented in Cetacea.

  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. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. Detection of Cryptosporidium sp. in two new seal species, Phoca vitulina and Cystophora cristata, and a novel Cryptosporidium genotype in a third seal species, Pagophilus groenlandicus, from the Gulf of Maine.

    PubMed

    Bass, A L; Wallace, C C; Yund, P O; Ford, T E

    2012-04-01

    Data on the geographic distribution and host specificity of Cryptosporidium spp. are critical for developing an understanding of likely transmission patterns in nature. During a molecular-based survey of fecal samples from 293 terrestrial and aquatic animals in Maine, USA, we detected Cryptosporidium sp. in 11 harbor seals (Phoca vitulina), 1 hooded seal (Cystophora cristata), and 1 harp seal (Pagophilus groenlandicus). None of the terrestrial or freshwater mammal fecal samples or bird samples tested positive for Cryptosporidium sp. However, the sequencing results of the small subunit (ssu) rRNA gene indicate that the seals were infected with an undescribed species of Cryptosporidium , previously isolated only from ringed seals (Phoca hispida) in northern Quebec, Canada. In addition, the Cryptosporidium sp. detected in the harp seal is significantly different from the previously observed Cryptosporidium sp. in other seals. We confirmed the genetic distinctiveness of this Cryptosporidium genotype and the identity of the other Cryptosporidium sp. seal ssu rRNA sequences by using data from the 70-kDa heat shock protein gene. Based on phylogenetic reconstructions of both genes, it seems that either Cryptosporidium canis or C. felis are sister species to the seal associated Cryptosporidium spp. Our findings extend the range of " Cryptosporidium sp. seal" well south of the 55th parallel, add other species to the list of seals affected by Cryptosporidium sp., and highlight the presence of unrecognized population and potentially species level variation in Cryptosporidium.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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)

  18. 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.

  19. "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…

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Comparison of toxaphene congeners levels in five seal species from eastern Canada: what is the importance of biological factors?

    PubMed

    Gouteux, Bruno; Lebeuf, Michel; Hammill, Mike O; Muir, Derek C G; Gagné, Jean-Pierre

    2005-03-15

    Environmentally relevant chlorobornanes (CHBs) were measured in blubber samples of harbor (Phoca vitulina), gray (Halichoerus grypus), harp (Phoca groenlandica), and hooded seals (Cystophora cristata) sampled in different part of the St. Lawrence marine ecosystem (SLME) and ringed seals (Phoca hispida) sampled in the eastern Canadian Arctic waters. The purpose of this study was to compare the levels of six CHBs (Parlar-26, -40/-41, -44, -50, and -62) among the five seal species. Seal species could be separated into three groups based on their respective sigmaCHB mean concentrations (+/-standard error): gray (49+/-3.9 ng/g lipid weight) and harbor (80+/-20 ng/g lipid weight) seals were more contaminated than ringed seals (18+/-7.6 ng/g lipid weight) but less contaminated than harp (370+/-87 ng/g lipid weight) and hooded (680+/-310 ng/g lipid weight) seals. These differences are not expected to be related to different sources of toxaphene contamination, since both the SLME and the eastern Canadian Arctic environments are thought to be mainly contaminated via atmospheric transportfrom the southeastern part of the United States. Thus, biological factors such as sex, age, nutritive condition, metabolism capacity, and diet of the animals collected were considered. Results reported in this study indicated that the diet is likely the main factor accounting for interspecies variations in toxaphene contamination in seals from eastern Canada.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Accelerated Implementation of Harbor Processes Research

    DTIC Science & Technology

    2006-05-31

    WATERSHEDS, *BIODEGRADATION, *SEDIMENTS, INDUSTRIES, STRATEGY, WATER, NAVY, SITES, SEASONAL VARIATIONS, SAMPLING, CONTAMINANTS, HARBORS, OCEAN BOTTOM, ANALYTICAL CHEMISTRY , TOXICOLOGY, OCEANOGRAPHY, ESTUARIES.

  16. 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.

  17. 33 CFR 207.480 - Lake Huron, Mich.; Harbor of refuge, Harbor Beach; use and navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Lake Huron, Mich.; Harbor of refuge, Harbor Beach; use and navigation. 207.480 Section 207.480 Navigation and Navigable Waters CORPS... Huron, Mich.; Harbor of refuge, Harbor Beach; use and navigation. (a) All boats, barges, and...

  18. 33 CFR 207.480 - Lake Huron, Mich.; Harbor of refuge, Harbor Beach; use and navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Lake Huron, Mich.; Harbor of refuge, Harbor Beach; use and navigation. 207.480 Section 207.480 Navigation and Navigable Waters CORPS... Huron, Mich.; Harbor of refuge, Harbor Beach; use and navigation. (a) All boats, barges, and...

  19. 33 CFR 207.480 - Lake Huron, Mich.; Harbor of refuge, Harbor Beach; use and navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Lake Huron, Mich.; Harbor of refuge, Harbor Beach; use and navigation. 207.480 Section 207.480 Navigation and Navigable Waters CORPS... Huron, Mich.; Harbor of refuge, Harbor Beach; use and navigation. (a) All boats, barges, and...

  20. 33 CFR 207.480 - Lake Huron, Mich.; Harbor of refuge, Harbor Beach; use and navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Lake Huron, Mich.; Harbor of refuge, Harbor Beach; use and navigation. 207.480 Section 207.480 Navigation and Navigable Waters CORPS... Huron, Mich.; Harbor of refuge, Harbor Beach; use and navigation. (a) All boats, barges, and...

  1. Amphibious hearing in ringed seals (Pusa hispida): underwater audiograms, aerial audiograms and critical ratio measurements.

    PubMed

    Sills, Jillian M; Southall, Brandon L; Reichmuth, Colleen

    2015-07-01

    Ringed seals (Pusa hispida) are semi-aquatic marine mammals with a circumpolar Arctic distribution. In this study, we investigate the amphibious hearing capabilities of ringed seals to provide auditory profiles for this species across the full range of hearing. Using psychophysical methods with two trained ringed seals, detection thresholds for narrowband signals were measured under quiet, carefully controlled environmental conditions to generate aerial and underwater audiograms. Masked underwater thresholds were measured in the presence of octave-band noise to determine critical ratios. Results indicate that ringed seals possess hearing abilities comparable to those of spotted seals (Phoca largha) and harbor seals (Phoca vitulina), and considerably better than previously reported for ringed and harp seals. Best sensitivity was 49 dB re. 1 µPa (12.8 kHz) in water, and -12 dB re. 20 µPa (4.5 kHz) in air, rivaling the acute hearing abilities of some fully aquatic and terrestrial species in their respective media. Critical ratio measurements ranged from 14 dB at 0.1 kHz to 31 dB at 25.6 kHz, suggesting that ringed seals--like other true seals--can efficiently extract signals from background noise across a broad range of frequencies. The work described herein extends similar research on amphibious hearing in spotted seals recently published by the authors. These parallel studies enhance our knowledge of the auditory capabilities of ice-living seals, and inform effective management strategies for these and related species in a rapidly changing Arctic environment.

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. Army Engineers at Pearl Harbor

    DTIC Science & Technology

    2011-01-01

    the Honolulu Engi- neer District, then part of the South Pacific Division. Colonel Albert K.B. Lyman , a native Hawaiian who later attained the rank...aircraft dis- persal at Wheeler Field. On the civil side, Lieutenant Colonel Theodore Wyman, the Honolulu District Engineer, had offices employing 10...Army Engineers at Pearl Harbor Past in Review Native Hawaiian Colonel Albert K.B. Lyman , the Army’s Ha- waiian Department engineer during the attack

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Model of Dredging Impact on Dungeness Crab in Grays Harbor, Washington

    DTIC Science & Technology

    1987-06-01

    along the coast for the largest juvenile stage and adult instar stages Al - A3 ....................... 26 2.3 Correspondence between age and instar...46 2.19 Refined schematic showing generalized movements of juvenile Dungeness crab to and from Grays Harbor and the the...the Grays Harbor subtidal at certain times of the year. Natural survival of juvenile crab was estimated from age-class abundance estimates from a Sea

  17. Effects of sediment remediation on reproductive function in English sole from Eagle Harbor, WA

    SciTech Connect

    Johnson, L.L.; Sol, S.Y.; Lomax, D.P.; Myers, M.S.; Collier, T.K.

    1995-12-31

    Eagle Harbor, near Bainbridge Island in Puget Sound, WA is currently designated as an EPA Superfund site because of high levels of creosote-derived PAHs in the sediments. In 1986--88, the authors conducted a series of studies evaluating reproductive function in English sole from Eagle Harbor. These studies showed that only about 60% of adult female sole from the Eagle Harbor site entered vitellogenesis, in comparison to 80--90% of females of comparable age and size from minimally contaminated Puget Sound sites. Eagle Harbor fish also exhibited reduced spawning success and lowered egg viability in comparison to fish from unpolluted sites. Both types of reproductive function were associated with depressed plasma levels of reproductive steroids (e.g. 17-B estradiol) in Eagle Harbor fish. In September of 1993 the EPA began placement of a cap of uncontaminated sediment over the most contaminated portions of Eagle Harbor, as a means of providing clean habitat for benthic organisms and reducing risk from the contaminants contained in the sediments. Since the time of capping, the authors have been monitoring reproductive development in English sole and related benthic flatfish to determine whether this restoration will result in improved reproductive success in the resident flatfish of Eagle Harbor. Preliminary results indicate that the proportion of maturing females has increased to approximately 75%. Other reproductive parameters, including plasma steroid hormone concentration and ovarian atresia, are currently being assessed. Nonetheless, the initial data suggest that sediment remediation is associated with improved reproductive function in Eagle Harbor bottom fish.

  18. 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.

  19. 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.

  20. 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.

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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

  16. 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.

  17. Metagenomic Survey of Viral Diversity Obtained from Feces of Subantarctic and South American Fur Seals

    PubMed Central

    Kluge, Mariana; Campos, Fabrício Souza; Tavares, Maurício; de Amorim, Derek Blaese; Valdez, Fernanda Pedone; Giongo, Adriana; Roehe, Paulo Michel; Franco, Ana Claudia

    2016-01-01

    The Brazilian South coast seasonally hosts numerous marine species, observed particularly during winter months. Some animals, including fur seals, are found dead or debilitated along the shore and may harbor potential pathogens within their microbiota. In the present study, a metagenomic approach was performed to evaluate the viral diversity in feces of fur seals found deceased along the coast of the state of Rio Grande do Sul. The fecal virome of two fur seal species was characterized: the South American fur seal (Arctocephalus australis) and the Subantarctic fur seal (Arctocephalus tropicalis). Fecal samples from 10 specimens (A. australis, n = 5; A. tropicalis, n = 5) were collected and viral particles were purified, extracted and amplified with a random PCR. The products were sequenced through Ion Torrent and Illumina platforms and assembled reads were submitted to BLASTx searches. Both viromes were dominated by bacteriophages and included a number of potentially novel virus genomes. Sequences of picobirnaviruses, picornaviruses and a hepevirus-like were identified in A. australis. A rotavirus related to group C, a novel member of the Sakobuvirus and a sapovirus very similar to California sea lion sapovirus 1 were found in A. tropicalis. Additionally, sequences of members of the Anelloviridae and Parvoviridae families were detected in both fur seal species. This is the first metagenomic study to screen the fecal virome of fur seals, contributing to a better understanding of the complexity of the viral community present in the intestinal microbiota of these animals. PMID:26986573

  18. Metagenomic Survey of Viral Diversity Obtained from Feces of Subantarctic and South American Fur Seals.

    PubMed

    Kluge, Mariana; Campos, Fabrício Souza; Tavares, Maurício; de Amorim, Derek Blaese; Valdez, Fernanda Pedone; Giongo, Adriana; Roehe, Paulo Michel; Franco, Ana Claudia

    2016-01-01

    The Brazilian South coast seasonally hosts numerous marine species, observed particularly during winter months. Some animals, including fur seals, are found dead or debilitated along the shore and may harbor potential pathogens within their microbiota. In the present study, a metagenomic approach was performed to evaluate the viral diversity in feces of fur seals found deceased along the coast of the state of Rio Grande do Sul. The fecal virome of two fur seal species was characterized: the South American fur seal (Arctocephalus australis) and the Subantarctic fur seal (Arctocephalus tropicalis). Fecal samples from 10 specimens (A. australis, n = 5; A. tropicalis, n = 5) were collected and viral particles were purified, extracted and amplified with a random PCR. The products were sequenced through Ion Torrent and Illumina platforms and assembled reads were submitted to BLASTx searches. Both viromes were dominated by bacteriophages and included a number of potentially novel virus genomes. Sequences of picobirnaviruses, picornaviruses and a hepevirus-like were identified in A. australis. A rotavirus related to group C, a novel member of the Sakobuvirus and a sapovirus very similar to California sea lion sapovirus 1 were found in A. tropicalis. Additionally, sequences of members of the Anelloviridae and Parvoviridae families were detected in both fur seal species. This is the first metagenomic study to screen the fecal virome of fur seals, contributing to a better understanding of the complexity of the viral community present in the intestinal microbiota of these animals.

  19. 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.

  20. Amphibious hearing in spotted seals (Phoca largha): underwater audiograms, aerial audiograms and critical ratio measurements.

    PubMed

    Sills, Jillian M; Southall, Brandon L; Reichmuth, Colleen

    2014-03-01

    Spotted seals (Phoca largha) inhabit Arctic regions that are facing both rapid climate change and increasing industrialization. While little is known about their sensory capabilities, available knowledge suggests that spotted seals and other ice seals use sound to obtain information from the surrounding environment. To quantitatively assess their auditory capabilities, the hearing of two young spotted seals was tested using a psychophysical paradigm. Absolute detection thresholds for tonal sounds were measured in air and under water over the frequency range of hearing, and critical ratios were determined using octave-band masking noise in both media. The behavioral audiograms show a range of best sensitivity spanning four octaves in air, from approximately 0.6 to 11 kHz. The range of sensitive hearing extends across seven octaves in water, with lowest thresholds between 0.3 and 56 kHz. Critical ratio measurements were similar in air and water and increased monotonically from 12 dB at 0.1 kHz to 30 dB at 25.6 kHz, indicating that the auditory systems of these seals are quite efficient at extracting signals from background noise. This study demonstrates that spotted seals possess sound reception capabilities different from those previously described for ice seals, and more similar to those reported for harbor seals (Phoca vitulina). The results are consistent with the amphibious lifestyle of these seals and their apparent reliance on sound. The hearing data reported herein are the first available for spotted seals and can inform best management practices for this vulnerable species in a changing Arctic.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Neuroglobin of seals and whales: evidence for a divergent role in the diving brain.

    PubMed

    Schneuer, M; Flachsbarth, S; Czech-Damal, N U; Folkow, L P; Siebert, U; Burmester, T

    2012-10-25

    Although many physiological adaptations of diving mammals have been reported, little is known about how their brains sustain the high demands for metabolic energy and thus O(2) when submerged. A recent study revealed in the deep-diving hooded seal (Cystophora cristata) a unique shift of the oxidative energy metabolism and neuroglobin, a respiratory protein that is involved in neuronal hypoxia tolerance, from neurons to astrocytes. Here we have investigated neuroglobin in another pinniped species, the harp seal (Pagophilus groenlandicus), and in two cetaceans, the harbor porpoise (Phocoena phocoena) and the minke whale (Balaenoptera acutorostrata). Neuroglobin sequences, expression levels and patterns were compared with those of terrestrial relatives, the ferret (Mustela putorius furo) and the cattle (Bos taurus), respectively. Neuroglobin sequences of whales and seals only differ in two or three amino acids from those of cattle and ferret, and are unlikely to confer functional differences, e.g. in O(2) affinity. Neuroglobin is expressed in the astrocytes also of P. groenlandicus, suggesting that the shift of neuroglobin and oxidative metabolism is a common adaptation in the brains of deep-diving phocid seals. In the cetacean brain neuroglobin resides in neurons, like in terrestrial mammals. However, neuroglobin mRNA expression levels were 4-15 times higher in the brains of harbor porpoises and minke whales than in terrestrial mammals or in seals. Thus neuroglobin appears to play a specific role in diving mammals, but seals and whales have evolved divergent strategies to cope with cerebral hypoxia. The specific function of neuroglobin that conveys hypoxia tolerance may either relate to oxygen supply or protection from reactive oxygen species. The different strategies in seals and whales resulted from a divergent evolution and an independent adaptation to diving.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 33 CFR 100.109 - Winter Harbor Lobster Boat Race, Winter Harbor, ME.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Winter Harbor Lobster Boat Race, Winter Harbor, ME. 100.109 Section 100.109 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Lobster Boat Race, Winter Harbor, ME. (a) Regulated area. The regulated area includes all waters of...

  9. Entry and elimination of marine mammal Brucella spp. by hooded seal (Cystophora cristata) alveolar macrophages in vitro.

    PubMed

    Larsen, Anett K; Nymo, Ingebjørg H; Boysen, Preben; Tryland, Morten; Godfroid, Jacques

    2013-01-01

    A high prevalence of Brucellapinnipedialis serology and bacteriology positive animals has been found in the Northeast Atlantic stock of hooded seal (Cystophoracristata); however no associated gross pathological changes have been identified. Marine mammal brucellae have previously displayed different infection patterns in human and murine macrophages. To investigate if marine mammal Brucella spp. are able to invade and multiply in cells originating from a presumed host species, we infected alveolar macrophages from hooded seal with a B. pinnipedialis hooded seal isolate. Hooded seal alveolar macrophages were also challenged with B. pinnipedialis reference strain (NCTC 12890) from harbor seal (Phocavitulina), B. ceti reference strain (NCTC 12891) from harbor porpoise (Phocoenaphocoena) and a B. ceti Atlantic white-sided dolphin (Lagenorhynchusacutus) isolate (M83/07/1), to evaluate possible species-specific differences. Brucella suis 1330 was included as a positive control. Alveolar macrophages were obtained by post mortem bronchoalveolar lavage of euthanized hooded seals. Phenotyping of cells in the lavage fluid was executed by flow cytometry using the surface markers CD14 and CD18. Cultured lavage cells were identified as alveolar macrophages based on morphology, expression of surface markers and phagocytic ability. Alveolar macrophages were challenged with Brucella spp. in a gentamicin protection assay. Following infection, cell lysates from different time points were plated and evaluated quantitatively for colony forming units. Intracellular presence of B. pinnipedialis hooded seal isolate was verified by immunocytochemistry. Our results show that the marine mammal brucellae were able to enter hooded seal alveolar macrophages; however, they did not multiply intracellularly and were eliminated within 48 hours, to the contrary of B. suis that showed the classical pattern of a pathogenic strain. In conclusion, none of the four marine mammal strains tested were able

  10. Entry and Elimination of Marine Mammal Brucella spp. by Hooded Seal (Cystophora cristata) Alveolar Macrophages In Vitro

    PubMed Central

    Larsen, Anett K.; Nymo, Ingebjørg H.; Boysen, Preben; Tryland, Morten; Godfroid, Jacques

    2013-01-01

    A high prevalence of Brucellapinnipedialis serology and bacteriology positive animals has been found in the Northeast Atlantic stock of hooded seal (Cystophoracristata); however no associated gross pathological changes have been identified. Marine mammal brucellae have previously displayed different infection patterns in human and murine macrophages. To investigate if marine mammal Brucella spp. are able to invade and multiply in cells originating from a presumed host species, we infected alveolar macrophages from hooded seal with a B. pinnipedialis hooded seal isolate. Hooded seal alveolar macrophages were also challenged with B. pinnipedialis reference strain (NCTC 12890) from harbor seal (Phocavitulina), B. ceti reference strain (NCTC 12891) from harbor porpoise (Phocoenaphocoena) and a B. ceti Atlantic white-sided dolphin (Lagenorhynchusacutus) isolate (M83/07/1), to evaluate possible species-specific differences. Brucella suis 1330 was included as a positive control. Alveolar macrophages were obtained by post mortem bronchoalveolar lavage of euthanized hooded seals. Phenotyping of cells in the lavage fluid was executed by flow cytometry using the surface markers CD14 and CD18. Cultured lavage cells were identified as alveolar macrophages based on morphology, expression of surface markers and phagocytic ability. Alveolar macrophages were challenged with Brucella spp. in a gentamicin protection assay. Following infection, cell lysates from different time points were plated and evaluated quantitatively for colony forming units. Intracellular presence of B. pinnipedialis hooded seal isolate was verified by immunocytochemistry. Our results show that the marine mammal brucellae were able to enter hooded seal alveolar macrophages; however, they did not multiply intracellularly and were eliminated within 48 hours, to the contrary of B. suis that showed the classical pattern of a pathogenic strain. In conclusion, none of the four marine mammal strains tested were able

  11. 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.

  12. 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.

  13. 33 CFR 117.1061 - Tacoma Harbor.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Tacoma Harbor. 117.1061 Section 117.1061 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Washington § 117.1061 Tacoma Harbor. (a) When...

  14. 33 CFR 117.1061 - Tacoma Harbor.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Tacoma Harbor. 117.1061 Section 117.1061 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Washington § 117.1061 Tacoma Harbor. (a) When...

  15. 33 CFR 117.1061 - Tacoma Harbor.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Tacoma Harbor. 117.1061 Section 117.1061 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Washington § 117.1061 Tacoma Harbor. (a) When...

  16. 33 CFR 117.1061 - Tacoma Harbor.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Tacoma Harbor. 117.1061 Section 117.1061 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Washington § 117.1061 Tacoma Harbor. (a) When...

  17. 33 CFR 117.1061 - Tacoma Harbor.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Tacoma Harbor. 117.1061 Section 117.1061 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Washington § 117.1061 Tacoma Harbor. (a) When...

  18. 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.

  19. 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...

  20. 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...

  1. 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....

  2. 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...

  3. 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)...

  4. 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....

  5. 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...

  6. 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...

  7. 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....

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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)...

  15. 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)...

  16. 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...

  17. 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...

  18. 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...

  19. 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....

  20. 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...

  1. 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...

  2. 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)...

  3. 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...

  4. 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)...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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....

  14. 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...

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  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. Minimum audible angles for aerial pure tones in a northern elephant seal (Mirounga angustirostris)

    NASA Astrophysics Data System (ADS)

    Holt, Marla M.; Schusterman, Ronald J.; Southall, Brandon L.; Kastak, David

    2005-04-01

    Recent work has shown that several pinniped species localize aerial broadband signals as accurately as some terrestrial carnivores. Additionally, both harbor seals and California sea lions can better localize both the lower and higher frequencies of their hearing range compared to performance at intermediate frequencies. These results are congruent with the duplex theory of sound localization which states that low frequencies are localized by interaural time differences while high frequencies are localized by interaural intensity differences. Northern elephant seals are land breeding pinnipeds whose range of best hearing sensitivity is shifted toward lower frequencies compared to other pinnipeds tested thus far. In this study, we tested a female northern elephant seal in a hemi-anechoic chamber at six frequencies ranging between 0.8 and 16 kHz that were presented at levels approximately 25 dB above threshold. A left/right behavioral procedure was used to measure minimum audible angles (MAAs) at 75 percent correct discrimination. MAAs ranged from approximately three to fifteen degrees. Best performance occurred at the lower frequencies while worse performance occurred at the two highest test frequencies. Unlike sea lions and harbor seals, this subject showed a decreased ability to utilize interaural intensity differences above 4 kHz.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Hospital Room Floors May Harbor 'Superbugs'

    MedlinePlus

    ... fullstory_163886.html Hospital Room Floors May Harbor 'Superbugs' But that area often overlooked when it comes ... Hospital room floors may be more of a "superbug" threat than many hospital staffers realize, new research ...

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. West Harbor, Ohio Recreational Navigation Improvement. Revision.

    DTIC Science & Technology

    1979-03-01

    natural sand beach at Gem Beach, and a length of shoreline which is essentially stable but which periodically ex- periences slight fluctuations in...dually to form an essentially flat plateau of land in the shoreward -11- direction. However, a few hundred feet to the east the beach rises from the...Harbor, which has remained essentially in its natural state in spite of the recreational and residential development of East and West Harbors, has been

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. Accumulation features and temporal trends of PCDDs, PCDFs and PCBs in Baikal seals (Pusa sibirica).

    PubMed

    Imaeda, Daisuke; Kunisue, Tatsuya; Ochi, Yoko; Iwata, Hisato; Tsydenova, Oyuna; Takahashi, Shin; Amano, Masao; Petrov, Evgeny A; Batoev, Valeriy B; Tanabe, Shinsuke

    2009-03-01

    This study investigated the accumulation features and temporal trends of PCDD/Fs, dioxin-like PCBs (DL-PCBs) and non-dioxin-like PCBs (NDL-PCBs) in the blubber of Baikal seals collected in 1992 and 2005. DL-PCBs (480-3600ng/g) and NDL-PCBs (980-35,000ng/g) were dominant contaminants. Concentrations of PCDDs and PCBs in males were significantly higher than in females. In males, age-dependent accumulation was observed for PCDDs, mono-ortho PCBs and NDL-PCBs. PCDFs and non-ortho PCBs showed no such trends, implying that exposure of seals to these contaminants has been decreasing in recent years. No decreasing temporal trend was observed for PCDDs, mono-ortho PCBs and NDL-PCBs, suggesting that Baikal seals are still exposed to PCDDs and PCBs. TEQs of PCDDs and mono-ortho PCBs in seals collected in 2005 accounted for 62-77% of total TEQs. The TEQ levels in 40% of the specimens exceeded the threshold level for immunosuppression observed in harbor seals (209pg/g).

  18. 33 CFR 80.1122 - Channel Islands Harbor, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Channel Islands Harbor, CA. 80... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1122 Channel Islands Harbor, CA. (a) A line drawn from Channel Islands Harbor South Jetty Light 2 to Channel Islands Harbor...

  19. 33 CFR 80.1122 - Channel Islands Harbor, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Channel Islands Harbor, CA. 80... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1122 Channel Islands Harbor, CA. (a) A line drawn from Channel Islands Harbor South Jetty Light 2 to Channel Islands Harbor...

  20. 33 CFR 80.1122 - Channel Islands Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Channel Islands Harbor, CA. 80... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1122 Channel Islands Harbor, CA. (a) A line drawn from Channel Islands Harbor South Jetty Light 2 to Channel Islands Harbor...