Journal articles on the topic 'Seals'
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1
Miller, Meredith L. "Seals, Joints, Seams, Leaks." Journal of Architectural Education 68, no. 1 (January 2, 2014): 82–93. http://dx.doi.org/10.1080/10464883.2013.817880.
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Darden, J. M., E. M. Earhart, and G. T. Flowers. "Comparison of the Dynamic Characteristics of Smooth Annular Seals and Damping Seals." Journal of Engineering for Gas Turbines and Power 123, no. 4 (March 1, 1999): 857–63. http://dx.doi.org/10.1115/1.1383256.
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Annular seals are known to enhance rotordynamic stability margins and minimize vibration response levels in high-speed rotating machinery. Theoretical predictions for the rotordynamic characteristics of annular seals exist but additional experimental data is needed to properly anchor these results. NASA’s Marshall Space Flight Center (MSFC) has developed an annular seal test rig and facility to experimentally characterize axially fed annular seals. Annular seals with deliberately roughened stators (i.e., damping seals) have been shown analytically to increase stability margins of rocket engine turbomachinery by reducing the seal’s whirl frequency ratio. The capabilities of MSFC’s annular seal test rig have been enhanced to allow high fluid inlet preswirl testing that is more representative of actual turbopump seal boundary conditions. The purpose of this paper is to describe the effect of this realistic preswirl on the stabilizing capability of both damping and smooth seals. Centered seal results are presented for both a smooth annular seal and a damping seal. These results were obtained for a range of seal pressure differentials, shaft rotational speeds, and two levels of inlet fluid preswirl.
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Murie, D. J., and D. M. Lavigne. "Interpretation of otoliths in stomach content analyses of phocid seals: quantifying fish consumption." Canadian Journal of Zoology 64, no. 5 (May 1, 1986): 1152–57. http://dx.doi.org/10.1139/z86-174.
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Thirteen captive phocid seals (10 grey seals (Halichoerus grypus), 2 harp seals (Phoca groenlandica), and 1 ringed seal (P. hispida)) were fed Atlantic herring (Clupea harengus harengus) in experiments designed to examine the use of otoliths recovered in stomach contents to interpret food consumption of wild seals. The percentage of ingested otoliths recovered in the stomach contents decreased with the time elapsed after feeding; 100% of otoliths were recovered between 0 and 3 h after feeding and 0% were recovered by 12.9 h after feeding. Absence of otoliths in the large intestine of seals having fed 3 to 6 h previous indicated that unrecovered otoliths had been digested (i.e., a complete disappearance of whole otoliths) while in the stomach. A significant relationship was also evident between the state of digestion of a seal's stomach contents, as measured by the proportion of otoliths remaining in skull cases (skull-recovered otoliths), and the duration of time since it had fed. These relationships have potential application in the estimation of daily fish consumption of seals feeding in the wild.
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Musin, A. "Small lead seals from Drochiczyn and small lead seals of “Drochiczyn type”: new light on the research on medieval “seal tags” in East-Central Europe." Archaeological News 31 (2021): 290–318. http://dx.doi.org/10.31600/1817-6976-2021-31-290-318.
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The article argues the commercial and fiscal nature of medieval small lead seals. For the first time, seal tags of the Piast dynasty are attested. Their symbols correlated with Polish Hohlpfennigs. The concentration of Rus’ and Polish seals on the border may indicate its dual jurisdiction. The practice of European small lead seals is regarded as transfers of the Byzantine tradition.
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Maaß, Eric, and Frederike D. Hanke. "Distance Estimation in Reproduction Tasks in a Harbor Seal (Phoca vitulina)." Water 13, no. 7 (March 30, 2021): 938. http://dx.doi.org/10.3390/w13070938.
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Harbor seals commute between haul-out places and feeding grounds close to the shore or in the open ocean, which is considered a low structured environment, at first sight not providing many cues for orientation/navigation. Nevertheless, seals are well-oriented. For returning to a specific location, seals may use both external and internal cues to, for example, perform path integration requiring the integration of distances traveled and angles steered. We herein assessed the seal’s ability to estimate distances, previously swum or unknown, in reproduction tasks. Reproduction tasks refer to an experimental paradigm in which the experimental animal is required to swim a specific distance first and subsequently reproduce this distance, with visual cues present or absent. The seal was able to estimate and then reproduce distances (0.5–18.5 m) with the smallest error below 10% of the actual distance, and its precision was higher with distances repeatedly swum compared to its performance with unfamiliar distances. In the absence of visual cues, the seal’s performance slightly dropped; however, it was still able to perform the task with an error of 21%. In conclusion, distance estimation may help seals to navigate precisely towards their goals, even if, for example, visual information is not available.
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You, Jia. "Gray seals: the North Sea's great whites?" Science 346, no. 6214 (December 4, 2014): 1196.4–1196. http://dx.doi.org/10.1126/science.346.6214.1196-d.
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Drabek, Charles M., and Jennifer M. Burns. "Heart and aorta morphology of the deep-diving hooded seal (Cystophora cristata)." Canadian Journal of Zoology 80, no. 11 (November 1, 2002): 2030–36. http://dx.doi.org/10.1139/z02-181.
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An investigation of the heart morphology of 8 male and 15 female hooded seals (Cystophora cristata) revealed that the heart is proportionately large and the aortic bulb is larger than that reported for most seals. Hooded seals of all ages have large hearts (0.64% of the body mass) and the right ventricle is proportionately longer and more muscular than reported for other seals. The bulb of the ascending aorta shows the large-diameter characteristic of seals capable of making long deep dives, and is constricted to a diameter of less than one-third in the descending aorta. In addition, the ascending aorta has a much greater concentration of elastin fibers than does the descending aorta. In combination with the large right ventricle, these features probably serve to increase lung perfusion during the hooded seal's surface recovery, and to maintain a high blood pressure throughout the cardiac cycle during diving bradycardia. That there was no substantive difference in the heart morphology of pups, yearlings, and adults, suggests that these features are important in the development of diving behavior, and agrees with the rapid behavioral and physiological development of hooded seal neonates.
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Zhang, Guoyuan, Yangyang Zhao, Weigang Zhao, Xiutian Yan, and Maotan Liang. "An experimental study on the cryogenic face seal at different inlet pressures." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 234, no. 9 (December 19, 2019): 1470–81. http://dx.doi.org/10.1177/1350650119896455.
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An experimental test system for cryogenic high-speed hydrodynamic non-contact mechanical seals is developed. Based on this system, the performances of seals under different working conditions are studied in detail in this paper. With the experimental results, the main performances of the seals (such as inlet and outlet temperatures, separated speed, face temperature, friction force, friction coefficient, leakage rate) are obtained, and the relationships of the performances with the inlet fluid pressure, the closing force and the rotational speed are discussed. The results show that the difference between the outlet and inlet temperatures decreases with increasing inlet fluid pressure. As the speed increases, the friction force varies little and remains at a constant value. The friction coefficient of the seal is approximately 0.12 and basically does not change with the speed. The leakage rate is also maintained at approximately 190 g/s. With the increase in the closing force, the friction at the seal’s face does not change greatly, which indicates that the friction at the face is always in a stable state with the seal’s closing force.
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Kienle, Sarah S., Jezebel Powers, Traci Kendall, Beau Richter, Leann Castle, Gwen Lentes, Daniel Costa, and Rita S. Mehta. "Context Matters: Hawaiian Monk Seals Switch Between Feeding Strategies Depending on Ecological Context." Integrative and Comparative Biology 60, no. 2 (July 29, 2020): 425–39. http://dx.doi.org/10.1093/icb/icaa075.
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Synopsis The ability to expand the behavioral repertoire past seemingly rigid morphological features enables animals to succeed in a variety of ecological contexts. The integration of morphology, performance, and behavior produces diverse animal feeding strategies. These different strategies reflect trade-offs between specialization, prey choice, and energetic expenditure, which have important consequences for understanding individual and population-level flexibility in response to environmental change. Here we examined the feeding strategies used by the Hawaiian monk seal (Neomonachus schauinslandi), an endangered marine predator. We tested how Hawaiian monk seal feeding strategies change in response to ecological context, specifically prey size and prey location at different depths. Seven captive Hawaiian monk seals were fed five prey types across a continuum of sizes, and prey were presented at three depths to represent surface, pelagic, and benthic feeding. Hawaiian monk seals used suction feeding and biting strategies, and these strategies were associated with significant differences in behavior and kinematic performance. Hawaiian monk seals used suction feeding most frequently when targeting small to medium prey (0–79% of the seal’s head length) but switched to biting when consuming large prey (>80% of the seal’s head length). These results demonstrate that prey size drives the transition between suction feeding and biting strategies. Seals also switched strategies based on prey position in the water column, primarily using suction feeding when prey were benthic and pelagic, and biting when prey were at the water’s surface. Overall, suction feeding was three to five times faster than biting, required a smaller gape, and used fewer jaw movements, allowing seals to quickly consume numerous small to medium sized prey. In contrast, biting was slower but resulted in the ability to target larger, potentially more energy rich prey. Our results show that Hawaiian monk seals exhibit flexibility in their use of different feeding strategies, which likely facilitates increased foraging success when feeding in spatially and temporally dynamic marine environments.
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Muir, Shona F., David K. A. Barnes, and Keith Reid. "Interactions between humans and leopard seals." Antarctic Science 18, no. 1 (March 2006): 61–74. http://dx.doi.org/10.1017/s0954102006000058.
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In July 2003 Kirsty Brown, a marine biologist at Rothera Research Station (West Antarctic Peninsula), was attacked and drowned by a leopard seal (Hydrurga leptonyx). As a direct consequence, a study was initiated to analyse interactions between humans and leopard seals over the last thirty years utilising humanistic and observational data. The response of leopard seals to humans in different situations was considered using a categorical response scale. Location of the leopard seal and human had the greatest influence on the response of the leopard seal. More specifically, interactions occurring at the ice edge, where leopard seals seek out prey, resulted in the highest response from leopard seals. ‘In water’ interactions, examined through SCUBA dive and snorkelling logs, generally described the seal’s behaviour as displaying curiosity and occurred most frequently at the surface. Although leopard seals approached close to observers and displayed behaviour that appeared aggressive, there were no records of interactions where ‘curious’ leopard seals showed subsequent hunting, or attack behaviour. In contrast, in most interactions (only a few occasions) where physical contact was initiated by a seal, in the form of an attack, the seal was not seen prior to the attack. Kirsty’s incident is the only known account of its kind, given that physical contact occurred at the surface of the water, and the seal had not been seen prior to the attack. This suggests that the commonly cited descriptions of leopard seals interacting with humans in the water are a distinctly different behaviour to that displayed in the attack on Kirsty. Although leopard seal behaviour was generally described by divers as curious, the death of Kirsty Brown indicates that leopard seals can display predatory behaviour towards humans.
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Periyasamy, Mookkan, Carmen J. Quartapella, Nicholas P. Piacente, Gary Reichl, and Brian Lynn. "Smart Quantum Tunneling Composite Sensors to Monitor FKM and FFKM Seals." Sensors 23, no. 3 (January 25, 2023): 1342. http://dx.doi.org/10.3390/s23031342.
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Operators of industrial machinery relentlessly pursue improving safety, increasing productivity, and minimizing unplanned downtime. Elastomer seals are ubiquitous components of this machinery. In general, static seals are designed to be compressed at a fixed level of compression, taking gland geometry, loading condition, temperature range of operation, fluid media exposure, and other factors into account to ensure the safe operation of equipment. Over time, seals experience compression set, chemical-induced swelling, erosion, and other phenomena which can compromise the compressive force generated by the seal and cause leaking. This is particularly important in critical applications, where high pressure, high temperature, and aggressive media are present, and fluorinated elastomers are common materials for seals. Further, changes in operating conditions at manufacturing plants, either intentional or through regular process variation, create unknown operating conditions for seals. This unknown and variable application environment makes seal performance hard to predict. Therefore, machinery utilizing seals is, at best, serviced preventatively at certain intervals, where seals are removed, and the remaining useful life of the seal is unknown. This leads to unnecessary machinery downtime and increases consumable costs for manufacturers. In the worst case, the seal is run to failure, creating machinery and plant safety concerns. Both scenarios are undesirable for manufacturers using industrial machinery. This paper reports on the development of “smart” intrinsic self-sensing seals, which enable performance monitoring of the compression behavior of seals while in use. In addition, this paper examines quantum tunneling elastomeric composites (QTC) to demonstrate a method of component performance monitoring by modifying the underlying elastomeric material itself. This paper studies QTC sensor-based fluorinated (FKM) and per-fluorinated (FFKM) compositions, which are modified to incorporate varying levels of carbon nanostructure (CNS) material. The resulting seal’s resistive properties are shown to be a function of the level of compression, the first time this phenomenon has been demonstrated in high-performing FKM and FFKM seal materials.
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Ryg, Morten, Thomas G. Smith, and Nils Are Øritsland. "Seasonal changes in body mass and body composition of ringed seals (Phoca hispida) on Svalbard." Canadian Journal of Zoology 68, no. 3 (March 1, 1990): 470–75. http://dx.doi.org/10.1139/z90-069.
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Seasonal changes in body mass and body composition of ringed seals (Phoca hispida) from the Svalbard Islands are described. The blubber content of adult females decreased from a high of about 50% at the beginning of the pupping season in March–April to a low of 31% during moulting in June. In adult males, the blubber content decreased from 41% in March to 29% in June. By estimating an individual seal's body mass by 1 April from its standard body length, we calculated an average daily loss of body mass of 160 g/day in adult females and 100 g/day in adult males from the start of lactation to the middle of moulting. The blubber content of sexually immature seals was less in June and July than in April, but the seasonal changes were smaller than in adult seals. We found no evidence of significant changes in core mass in adult seals, and suggest that the seasonal body mass changes are mostly due to changes in body fat content.
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Clark, Quentin. "Symbolizing Reverence and Imperial Identity: The Elephant on the epi ton barbaron Seal." Comitatus: A Journal of Medieval and Renaissance Studies 54, no. 1 (2023): 1–18. http://dx.doi.org/10.1353/cjm.2023.a912669.
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Abstract: Recent scholarship on Byzantine seals has broadened our understanding of both the practical and symbolic functions of these objects, as it primarily concerns their material, iconographic, and epigraphic content. This article focuses on one of only two known Byzantine seals featuring an image of an elephant. This eleventh-century seal belonged to an individual bearing the title “ἐπὶ τῶν βαρβάρων” ( epi ton barbaron ). Receiving little scholarly attention, this object is generally discussed in the context of other seals of the Byzantine period. I offer a new reading of this object and its image, arguing that the elephant on this seal served two primary functions: it represented its owner’s claim to imperial identity, and it also symbolized its owner’s reverence for the emperor. Through close iconographic and social art historical analysis, I examine the elephant’s use during the Roman and Byzantine periods in three distinct categories: as a motif, as material, and as a living animal. I draw upon primary texts, seals, and ivory objects of the Byzantine period to emphasize the elephant’s imperial associations. I also analyze this seal’s image in conjunction with the administrative titles present in this object’s inscription— epi ton barbaron , in particular. This article expands the ways in which both the iconographic and epigraphic content of Byzantine seals can be used to interpret the symbolic identities their owner’s often project.
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Dodd, Wayne. "Seals." Antioch Review 48, no. 1 (1990): 86. http://dx.doi.org/10.2307/4612148.
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Davis, Rachel Meredith. "Material evidence? Re-approaching elite women’s seals and charters in late medieval Scotland." Proceedings of the Society of Antiquaries of Scotland 150 (November 30, 2021): 301–26. http://dx.doi.org/10.9750/psas.150.1318.
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Medieval Scottish women’s seals remain largely unexplored compared to the scholarship on seals and sealing practice elsewhere in medieval Britain. This article has two chief aims. First, it seeks to demonstrate the insufficiencies of the 19th- and 20th-century Scottish seal catalogues as a mediated record of material evidence and the use of them as comprehensive and go-to reference texts within current research on late medieval Scotland. This includes a discussion of the ways in which medieval seals survive as original impressions, casts and illustrations and how these different types of evidence can be used in the construction and reconstruction of the seal’s and charter’s context. Second, this paper will explore the materiality and interconnectedness of seals and the charters to which they are attached. A reading of these two objects together emphasises the legal function of the seal and shows its distinctive purpose as a representational object. While the seal was used in con-texts beyond the basic writ charter, it remained a legally functional and (auto)biographical object, and, as such, the relationship between seal and charter informs meaning in representational identities expressed in both. The article will apply this approach to several examples of seals belonging to 14th- and 15th-century Scottish countesses. Evidence reviewed this way provides new insight into Scottish women’s sealing practice and female use of heraldic device. The deficiencies of assuming women’s design to be formulaic or that their seals can be usefully interpreted in isolation from the charters to which they were attached will be highlighted. The interconnectedness of word and image conveyed personal links and elite ambitions, and promoted noble lineage within the legal context of charter production.
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Zhang, Xiumin, Mingfu Yin, and Huilai Sun. "Establishment and solution of governing equation for plana-grooved liquid seals based on three-control-volume theory." Industrial Lubrication and Tribology 72, no. 3 (November 18, 2019): 257–66. http://dx.doi.org/10.1108/ilt-06-2019-0228.
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Purpose This paper aims to study the dynamic characteristics of the straight-through labyrinth seals, which is applied on an oil sealing belt of hydrostatic support system (HSS) oil pocket, the establishment and solution process of seal governing equation is deduced. Design/methodology/approach The three-control-volume model theory is an efficient approach that is applied well. This paper starts with three relative governing equations for the flow characteristics of straight-through labyrinth seals in the plane direction. Referring to the establishment process of governing equations for circumferentially-grooved liquid seals, the governing equation based on space rectangular coordinate system is established, which are transformed into dimensionless equations through a nondimensionalized process and solved by a perturbation method. It contains a zeroth-order equation, through which a steady fluid distribution is determined, and a first-order equation, through which the seal’s dynamic coefficients can be acquired. Findings The governing equation for plane-grooved straight-through labyrinth seals can be established and solved by the three-control-volume theory. Practical implications This study have important guiding significance for further theoretical research and structural design of the straight-through labyrinth seals on the oil sealing belt of HSS oil pocket. Originality/value In this paper, a straight-through labyrinth seal is installed in an oil sealing belt. The three-control-volume governing equations is established in space rectangular coordinate system, and the shear force of the fluid Y-direction is different from the previous model.
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Khoyetskyy, Pavlo B. "Monitoring of the leopard seal population (Hydrurga leptonyx) in waters of the Argentine Islands (Ant-arctica)." Theriologia Ukrainica 2020, no. 19 (August 27, 2020): 138–47. http://dx.doi.org/10.15407/tu1916.
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The state of the leopard seal population (Hydrurga leptonyx Blainville, 1828) in waters of the Argentine Islands was studied during the periods April 2015 — March 2016 and April 2018 — March 2019 according to the objectives of the State Target Scientific and Technical Research Programme of Ukraine in Antarctica for the period 2011–2020. During the study period, 14 males and 16 females were recorded within the archipelago (1M : 1.1F ratio). About 7 % of the seals were young individuals and more than 90% were adults. Leopard seals were recorded during all periods of the year. In the summer-autumn period, within the archipelago, there were 2 to 4 individuals simultaneously. The maximum period of stay of the predators in waters of the archipelago was about two weeks. Two individuals for at least two weeks were recorded twice in waters of the archipelago. The maximum period of absence of the seals in waters of the archipelago was 118 days. It was found that the occurrence of leopard seals and hence the traces of their life activities in various years were of different nature. In the autumn (April–May) of 2015, they were seen less frequently, on average every 6.3 ± 2.5 days, and in the autumn of 2018, on the contrary, more frequently, on average every 2.5 ± 0.5 days. The activity of the leopard seal in the winter (June, August) of 2015 decreased by half. It was recorded that the animals appeared in waters of the archipelago on average every 12.7 ± 5.5 days, and in the winter of 2018 — 5.5 ± 1.9 days. In the autumn of 2018, the predators and traces of their vital activities were seen less often — every 6.6 ± 1.6 days. During the study period, out of 78 recorded cases of the leopard seal’s occurrence, about 56 % of cases were recorded when they were on ice floes, in other cases (44 %) — when they were in water. In addition, several crabeater seals were recorded three times on an ice floe at an insignificant distance from a leopard seal. One of the main prey items for leopard seals within the archipelago are birds, in particular the gentoo penguin (Pygoscelis papua), as well as crabeater seals (Lobodon carcinophagus). The presence of two penguin colonies on Galindez Island attracts leopard seals to the archipelago. During the study period, successful leopard seal predation on penguins was recorded more than 20 times. Penguins were the most frequent prey of leopard seals in spring and summer, while crabeater seals in winter.
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Tryland, Morten, Ingebjørg H. Nymo, Ole Nielsen, Erling S. Nordøy, Kit M. Kovacs, Bjørn A. Krafft, Stein I. Thoresen, et al. "SERUM CHEMISTRY AND ANTIBODIES AGAINST PATHOGENS IN ANTARCTIC FUR SEALS, WEDDELL SEALS, CRABEATER SEALS, AND ROSS SEALS." Journal of Wildlife Diseases 48, no. 3 (July 2012): 632–45. http://dx.doi.org/10.7589/0090-3558-48.3.632.
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Eron, C. "Dog Virus Seals Fate of European Seals." Science News 134, no. 10 (September 3, 1988): 149. http://dx.doi.org/10.2307/3972968.
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Iskakov, A. A., A. U. Shagilbaev, and M. T. Baimukanov. "Feeding of the caspian seal (Pusa caspica Gmelin, 1788) during haul out periods at the Kenderli rookery (Middle Caspian)." Bulletin of the Karaganda University “Biology medicine geography Series” 11429, no. 2 (June 29, 2024): 21–28. http://dx.doi.org/10.31489/2024bmg2/21-28.
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The Kendirli Haul-Out Site of the Caspian Seal served as the sole haul-out location in the Central Caspian Sea. Consequently, data obtained regarding the seal's diet at this site holds significant importance for the study and conservation of the Caspian Seal population. This study analyzed the diet of the Caspian Seal based on fecal collections from the Kendirli Haul-Out Site spanning from 2015 to 2019. Given the Caspian Seal's endangered status, a vital in vivo method of coprological analysis was employed to assess its diet. Comparative analysis of the seal's diet was conducted across seasons and years, and fish lengths consumed by seals were determined using otoliths extracted from feces. The study revealed that the Caspian Seal's diet at the Kendirli Haul-Out Site comprises 11 fish species, including species of the Cyprinidae family and Benthophilus genus, along with unidentified species of gobies. It was observed that the seal's diet varies seasonally; during autumn, the primary food source consists of gobies, whereas in spring, Atherina caspia predominates the diet. Additionally, carp species, Clupeonella caspia, and Alosa braschnikowi are present in the spring diet but absent in the autumn diet. Reconstruction of fish length ranges for three fish species — Neogobius melanostomus affinis, N. pallasi, and Alosa braschnikowi — demonstrated that seals consume fish ranging from 30 to 260 mm in length.
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He, Tao, Qiangqiang Zhang, Ying Yan, Jintong Dong, and Ping Zhou. "Numerical Simulation of a New Designed Mechanical Seals with Spiral Groove Structures." Lubricants 11, no. 2 (February 9, 2023): 70. http://dx.doi.org/10.3390/lubricants11020070.
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The spiral groove seal has a strong hydrodynamic effect, but it has poor pollution resistance at the seal’s end and has unfavorable sealing stability. Circumferential waviness seals can use the fluid to clean the surface and have a strong ability to self-rush, protecting the main cover from contamination. This study presents a novel wave-tilt-dam seal design that integrates spiral groove structures to enhance the hydrodynamic performance of circumferential waviness seals. The objective of the research is to evaluate the mechanical effectiveness of this new design through simulation modeling, with a focus on the impact of structural parameters such as rotational speed and seal pressure on the hydrodynamic behavior under various operating conditions. The results of the study indicate that the new structure effectively improves the hydrodynamic performance of the liquid seal, resulting in a significant increase in film rigidity. Additionally, the study identifies optimal values for structural parameters under specific conditions. By addressing the limitations of traditional spiral groove seals and improving their hydrodynamic performance, this research contributes to the advancement of seal technology.
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Bei, Guangyao, Xiaodong Xu, Chenbo Ma, Jianjun Sun, Yuyan Zhang, and Qiuping Yu. "Reliability Evaluation of a Dynamic-Pressure Mechanical Seal Based on Liquid Film Vaporization Phase Transition." Coatings 14, no. 2 (February 17, 2024): 233. http://dx.doi.org/10.3390/coatings14020233.
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Aiming at the problem of researching the reliability of dynamic-pressure mechanical seals, this paper proposes a reliability evaluation method for dynamic-pressure mechanical seals based on the Monte Carlo method. Based on the influence of the mass transfer coefficient on vaporization phase transition, a liquid film vaporization model of a hydrodynamic mechanical seal’s end face is established, and the working condition parameters and groove structure parameters are designed using the experimental design method. The vaporization characteristics of the liquid film under various parameters are analyzed, and the functional functions of the vaporization characteristics are obtained by fitting. Combined with the maximum vapor phase volume fraction when the dynamic-pressure mechanical seal changes from the liquid miscible phase to the vapor miscible phase, the limit state equation of the vapor phase volume fraction is obtained. Finally, based on the Monte Carlo simulation method, the sealing reliability under specific groove structure parameters is calculated. Our research shows that this method has practicability and effectiveness for the reliability evaluation of mechanical seals with different working conditions and different groove structures.
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Fedak, M. A., M. R. Pullen, and J. Kanwisher. "Circulatory responses of seals to periodic breathing: heart rate and breathing during exercise and diving in the laboratory and open sea." Canadian Journal of Zoology 66, no. 1 (January 1, 1988): 53–60. http://dx.doi.org/10.1139/z88-007.
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In terms of a seal's success as a predator, the ability to spend a high fraction of time submerged and yet remain in a steady state is at least as important as that to make long dives. This aspect of seal physiology has received much less attention than has the ability to dive for extended periods and yet is important to the context in which dive-related morphological and physiological specializations are considered. We found, in seals exercising in the laboratory, that as [Formula: see text] increased, heart rate during breathing bouts was high and unchanging. Heart rate during dives was 25 to 33% of the rate during breathing and was insensitive to metabolic rate. However, the fraction of time seals spent breathing and overall average heart rate increased with exercise. We have confirmed these patterns using very high frequency and acoustic telemetry in freely diving harbour seals in the open sea. Heart rate at the surface was virtually constant at 120 beats/min and independent of dive duration. While the seals were diving, heart rate fell to 40 beats/min. Average heart rate depended almost entirely on the proportion of time spent below the surface and only to a minor extent on dive length. The exceedingly low heart rates seen during forced dives in the laboratory were never observed at sea.
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Gosselin, Jean-François, Lena N. Measures, and Jean Huot. "Lungworm (Nematoda: Metastrongyloidea) infections in Canadian phocids." Canadian Journal of Fisheries and Aquatic Sciences 55, no. 4 (April 1, 1998): 825–34. http://dx.doi.org/10.1139/f97-306.
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Otostrongylus circumlitus (Railliet, 1899) was found in 5% (16/308) of grey seals (Halichoerus grypus), 6% (1/17; intensity = 38) of harbour seals (Phoca vitulina), and none of 100 harp seals (Phoca groenlandica) from eastern Canada and none of 31 ringed seals (Phoca hispida) from Holman, Northwest Territories. Eighty-two percent of these infections were observed in young-of-the-year seals. Filaroides (Parafilaroides) gymnurus (Railliet, 1899), detected in nodules in the superficial parenchyma of the lungs, infected 24% (5/16) of grey seals, 27% (4/15) of harbour seals, 57% (29/51) of harp seals, 81% (25/31) of ringed seals, and one stranded bearded seal (Erignathus barbatus) (new host report for harp, ringed, and bearded seals; new locality report for Holman). Filaroides (Parafilaroides) hispidus Kennedy, 1986 was found in systematically sliced lungs of grey seals (2/3; new host report) and ringed seals (2/7) but not in harp seals (n = 11) or harbour seals (n = 5). Intensity ranged from 37 to 3570 for F. (P.) gymnurus and from 295 to 1196 for F. (P.) hispidus. No detrimental effect on body condition of seals could be associated with infection by lungworms.
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Bester, M. N., J. W. H. Ferguson, and F. C. Jonker. "Population densities of pack ice seals in the Lazarev Sea, Antarctica." Antarctic Science 14, no. 2 (June 2002): 123–27. http://dx.doi.org/10.1017/s0954102002000676.
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From 15 December 1992–4 January 1993 aerial surveys of ice seals were undertaken by Puma helicopter across the pack ice off Dronning Maud Land. The 31 transects of 1/2 nautical mile (n.m.) width were flown at an elevation of 200 ft and a ground speed of 60 knots and covered 805.6 n.m.2 of pack ice. The overall species composition of the seals was 97.8% crabeater seals, 1.67% Ross seals, 0.34% leopard seals and 0.15% Weddell seals. The density abundance of seals was 2.47 n.m.−2 for crabeater, 0.01 n.m.−2 for leopard, 0.004 n.m.−2 for Weddell and 0.04 n.m.−2 for Ross seals. Leopard seals were largely found near the outer edge of the pack, Ross seals were absent only in the outer pack, whilst Weddell seals were virtually absent in the pack ice. Present throughout, crabeater seals and Ross seals showed a statistically significant preference for the inner pack, the reasons for this being unclear.
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Moon, Sang-leun(Ven Jung-Gak). "Korean acceptance and development of seals, such as Buddha-seals and Stupa-seals." Dongak Art History 34 (December 31, 2023): 89–125. http://dx.doi.org/10.17300/dah.2023.34.4.
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Dehn, Larissa-A., Gay G. Sheffield, Erich H. Follmann, Lawrence K. Duffy, Dana L. Thomas, Gerald R. Bratton, Robert J. Taylor, and Todd M. O'Hara. "Trace elements in tissues of phocid seals harvested in the Alaskan and Canadian Arctic: influence of age and feeding ecology." Canadian Journal of Zoology 83, no. 5 (May 1, 2005): 726–46. http://dx.doi.org/10.1139/z05-053.
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Concentrations of selected trace elements (Ag, Cu, Cd, Se, Zn, THg, and MeHg) were measured in tissues of subsistence-harvested ringed (Pusa hispida (Schreber, 1775)), bearded (Erignathus barbatus (Erxleben, 1777)), and spotted (Phoca largha Pallas, 1811) seals from Alaska and ringed seals from Canada. Most variables differed significantly in tissues of phocids analyzed. Concentration of renal Cd was highest in ringed seals from Canada and bearded seals from Alaska, while spotted seals had the lowest concentrations. Concentrations of Cd increased with age to a maximum in ringed and bearded seals, followed by a slow decline with increasing age. Spotted seals had the highest proportion of MeHg to THg (%MeHg) in liver and bearded seals the lowest ratio. THg in seal tissues followed the opposite trend. %MeHg in ringed and bearded seals followed a hyperbolic decay function with age, but was highly variable in spotted seals. Seals with lesions had a higher relative occurrence of MeHg in liver. The molar ratio of Se:THg in liver exceeded 1:1 in most seals and was negatively correlated with age in ringed and spotted seals. Hepatic Ag was higher in bearded seals than in ringed and spotted seals. A correlation of Ag with age was not documented.
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Mokerova, E. Yu, and K. N. Tarasov. "Vyatka Church Seals of Synodal Period: an Attempt at Classification (Collection of Sphragistics at P.V. Alabin Kirov Regional Local Lore Museum)." Nauchnyi dialog 12, no. 10 (December 23, 2023): 395–413. http://dx.doi.org/10.24224/2227-1295-2023-12-10-395-413.
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This article proposes a classification of Vyatka church seals from the 18th to the early 20th century based on materials from the collection of sphragistics at the P. V. Alabin Kirov Regional Local Lore Museum. The criteria for classification include the affiliation of the seals with specific individuals and institutions, as well as the specific images depicted on the seals. The article identifies four groups of seals: seals of church administration, seals of spiritual educational institutions, seals of churches, and personal seals of clergy. The study reveals that state symbols, such as the doubleheaded eagle, were typically depicted on seals of church administration and spiritual educational institutions. Seals of parish churches depicted real church buildings or saints until the first third of the 19th century when they were replaced by a standardized image of a three-domed church. Seals belonging to Vyatka bishops were typically twosided with images of a blessing hand and the Holy Trinity. From the mid-19th century, they were replaced by one-sided seals with images of two blessing hands. All personal seals of bishops have circular legends with their names. Seals belonging to other clergy members contain information about the owner’s name, initials, surname, and sometimes their rank. The most popular symbol for all groups of seals was the All-Seeing Eye, symbolizing God’s omniscience.
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Measures, L. N., J. F. Gosselin, and E. Bergeron. "Heartworm, Acanthocheilonema spirocauda (Leidy, 1858), infections in Canadian phocid seals." Canadian Journal of Fisheries and Aquatic Sciences 54, no. 4 (April 1, 1997): 842–46. http://dx.doi.org/10.1139/f96-342.
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Heartworm, Acanthocheilonema spirocauda, was observed in four of six species of seals (19 seals of 701) examined from the Atlantic coast of Canada including the Canadian Arctic. Fourteen of 221 ringed seals (Phoca hispida), 2 of 18 harbour seals (Phoca vitulina), 2 of 186 harp seals (Phoca groenlandica) (new host record), and the only hooded seal examined (Cystophora cristata) were infected with A. spirocauda. Intensity of infection ranged from 1 to 31. Infected seals were age 0 to 14, but 8 of the 14 infected ringed seals were age 0. All worms were found in the right ventricle except in three cases. In one ringed seal and one harp seal, worms were found in the pulmonary artery, and in another ringed seal, worms were found deep within the lungs. No infections were found in grey seals (Halichoerus grypus) (N = 271) or bearded seals (Erignathus barbatus) (N = 4). Heartworm is primarily a parasite of young seals. Its apparent absence in grey seals examined to date suggests either that a much larger sample of young seals from a broad geographic area is needed or that grey seals are refractory to infection or do not survive infections.
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Song, Xiaolei, Meihong Liu, Junfeng Sun, Juan Wang, and Kun Wang. "Temperature Field and Performance Analysis of Brush Seals Based on FEA-CFD and the Porous Medium of Anisotropic Heat Transfer Models." Energies 16, no. 21 (October 28, 2023): 7306. http://dx.doi.org/10.3390/en16217306.
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A brush seal is a type of contact sealing technology that generates a great amount of heat during operations. The heat can affect the seal’s performance and lifespan. To study the brush seals’ temperature distribution, a new model considering the anisotropic heat transfer effect is established in this paper. The friction heat effect at the bristles’ tip is studied. The temperature field and leakage rates are obtained by using combined finite element analysis (FEA)-computational fluid dynamics (CFD) analysis and the anisotropic heat transfer theory. The influence of operating and structural parameters on the temperature field and the sealing properties of the brush seal are investigated. It is shown that the value of the rotation rate and the interference can cause the temperature of the brush seal to increase. The pressure difference enhances the convective heat transfer from the brush seals. While the temperature at the bristles’ tip increases, the radial average temperature of the bristles decreases significantly. In the case of a small pressure difference, the fence’s height can increase the windward area, leading to stiff bristles and resulting in a temperature increase at the bristles’ tip; however, the effective flow area increases, resulting in an acceleration of the radial temperature’s decrease. To summarize, the porous medium model of anisotropic heat transfer provides a new method for studying brush seals, and it can reflect the temperature distribution and leakage performance of brush seals.
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Chen, Hanqing, Ruqi Yan, Xianzhi Hong, Xin Bao, and Xuexing Ding. "Micro-Groove Optimisation of High-Speed Inner Ring Micro-Grooved Pumping Seal for New Energy Electric Vehicles." Processes 12, no. 6 (June 20, 2024): 1281. http://dx.doi.org/10.3390/pr12061281.
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Traditional oil seals are insufficient for the high-speed and bi-directional rotation of new energy electric vehicles. Therefore, we developed a Python program focusing on micro-groove pump seals and examined the unexplored non-contact oil–air biphasic internal end-face seals. Real gas effects were described using the virial and Lucas equations. We introduced an oil–air ratio to determine the equivalent density and viscosity of the two-phase fluid in the seal. Furthermore, we solved the compressible steady-state Reynolds equation using the finite difference method. Analysing the seal’s pumping mechanisms and the effects of operating parameters on sealing performance, we assessed 17 types of hydrodynamic grooves. The results demonstrate that inverse fir tree-like grooves perform well under typical sealing conditions. Under the conditions given in this study, the pumping rate of the optimal groove type compared to other groove types even reached 633.54%. In the oil–air biphasic state, the micro-groove pump seal exerts significant dynamic pressure on the sealing surface. Seal opening force increases with rotational velocity, oil–air ratio, and inlet pressure but decreases with temperature. The pumping rate first increases and then decreases with rotational velocity, increases with oil–air ratio and temperature, and then decreases with inlet pressure. Some special working points require consideration in sealing design. Our results provide insights into designing micro-grooved pumping seals for new energy electric vehicles.
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DeMaster, Douglas P. "Elephant Seals." Ecology 76, no. 8 (December 1995): 2673–74. http://dx.doi.org/10.2307/2265843.
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Drickamer, Lee C. "Elephant Seals." Ecology 76, no. 8 (December 1995): 2676–77. http://dx.doi.org/10.2307/2265844.
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Doyle, James. "The Seals." Iowa Review 37, no. 1 (April 2007): 145. http://dx.doi.org/10.17077/0021-065x.6585.
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Wilson, Bill. "Mechanical seals." Industrial Lubrication and Tribology 47, no. 2 (April 1995): 4–11. http://dx.doi.org/10.1108/00368799510781187.
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Naini, F. B. "Lip seals." British Dental Journal 209, no. 3 (August 2010): 106. http://dx.doi.org/10.1038/sj.bdj.2010.682.
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Bechmann-Pasquinucci, H. "Quantum Seals." International Journal of Quantum Information 01, no. 02 (June 2003): 217–24. http://dx.doi.org/10.1142/s0219749903000139.
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A quantum seal is a way of encoding a classical message into quantum states, so that everybody can read the message error-free, but at the same time the sender and all intended readers who have some prior knowledge of the quantum seal, can check if the seal has been broken and the message read. The verification is done without reading nor disturbing the sealed message.
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Singh, Sudhir Kumar, and R. Srikanth. "Quantum Seals." Physica Scripta 71, no. 5 (January 1, 2005): 433–35. http://dx.doi.org/10.1238/physica.regular.071a00433.
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Levy, Eythan. "Hebrew Seals." Near Eastern Archaeology 86, no. 4 (December 1, 2023): 302–10. http://dx.doi.org/10.1086/727585.
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Teh Gallop, Annabel. "ONE SEAL GOOD, TWO SEALS BETTER, THREE SEALS BEST? MULTIPLE IMPRESSIONS OF MALAY SEALS." Indonesia and the Malay World 34, no. 100 (November 2006): 407–26. http://dx.doi.org/10.1080/13639810601130275.
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Osinga, Nynke, Pieter 't Hart, and Pieter van Voorst Vader. "Albinistic common seals (Phoca vitulina) and melanistic grey seals (Halichoerus grypus) rehabilitated in the Netherlands." Animal Biology 60, no. 3 (2010): 273–81. http://dx.doi.org/10.1163/157075610x516493.
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AbstractThe Seal Rehabilitation and Research Centre (SRRC) in Pieterburen, The Netherlands, rehabilitates seals from the waters of the Wadden Sea, North Sea and Southwest Delta area. Incidental observations of albinism and melanism in common and grey seals are known from countries surrounding the North Sea. However, observations on colour aberrations have not been systematically recorded. To obtain the frequency of occurrence of these colour aberrations, we analysed data of all seals admitted to our centre over the past 38 years. In the period 1971-2008, 3000 common seals (Phoca vitulina) were rehabilitated, as well as 1200 grey seals (Halichoerus grypus). A total of five albinistic common seals and four melanistic grey seals were identified. This results in an estimated incidence of albinism in common seals of approximately 1/600, and of melanism in grey seals of approximately 1/300. The seals displayed normal behaviour, although in the albinistic animals, a photophobic reaction was observed in daylight.
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Webb, P. M., D. E. Crocker, S. B. Blackwell, D. P. Costa, and B. J. Boeuf. "Effects of buoyancy on the diving behavior of northern elephant seals." Journal of Experimental Biology 201, no. 16 (August 15, 1998): 2349–58. http://dx.doi.org/10.1242/jeb.201.16.2349.
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Marine mammals experience radical seasonal changes in body composition, which would be expected to affect their buoyancy in the water. The aim of this study was to examine the relationship between such changes in buoyancy and diving behavior in northern elephant seals Mirounga angustirostris. This was achieved by modifying the buoyancy of 13 juvenile elephant seals translocated from Año Nuevo State Reserve, CA, USA, and released at various sites in Monterey Bay, CA, USA. The buoyancy of each seal was calculated and was increased or decreased using syntactic foam or lead weights, and their diving behavior was recorded as they returned to Año Nuevo. The seals were divided into three groups: increased buoyancy (B+), reduced buoyancy (B-) and control seals (Bc). Mean descent rates were 0.77+/-0.3 ms-1 for the B+ seals, 0.82+/-0.2 ms-1 for the control seals and 0.87+/-0.3 ms-1 for the B- seals, and were significantly different. Mean ascent rates for the three treatments were 0.82+/-0.3 ms-1 for the B+ seals, 0.86+/-0.3 ms-1 for the control seals and 0.82+/-0.3 ms-1 for the B- seals. All the B+ seals ascended faster than they descended, while four of the five B- seals descended faster than they ascended. There was a significant negative correlation between buoyancy and descent rate, with less buoyant seals descending faster than more buoyant seals. There was, however, no correlation between ascent rate and buoyancy. This suggests that seals may use negative buoyancy to drift passively during descent, but that all seals may swim continuously during ascent. There was a significant correlation between buoyancy and the drift descent rate of C-type drift dives, including upwards drift in the most buoyant seal. Buoyancy was not correlated with diving depth, trip duration, dive duration or surface-interval duration. This study demonstrates that buoyancy plays a significant role in shaping diving behavior in northern elephant seals and that elephant seals may adjust their behavior to suit their buoyancy, rather than adjusting their buoyancy to suit a dive. This study also validated the truncated cones method of calculating body composition in this species by comparing it with body composition determined using tritium dilution.
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Holii, Roman. "Jubilee album on the ocassion of 30th anniversary of metropolitan work of Andrew Sheptytsky as a sphragistic source (from collection of Research Institute for Library's Art Resources, Vasyl Stefanyk National Scientific Library of Ukraine in Lviv)." Proceedings of Vasyl Stefanyk National Scientific Library of Ukraine in Lviv, no. 14(30) (December 2022): 327–45. http://dx.doi.org/10.37222/2524-0315-2022-14(30)-13.
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The anniversary album of A. Sheptytsky belongs to the unique historical sources of 1930–1931. There are almost 150 seals in the album. This seals are represented by Ukrainian sphragistics of the end of the 19th – the first third of the 20th centuries. The album contains church deanery and parish seals of the Stryi Protopresbytery of the Lviv Diocese, which included the Bolehivskyi, Dolynskyi, Zhydachivskyi, Zhuravenskyi, Lyubinetskyi, Mykolaivskyi, Peregyn- s- kyi, Rozhnyativskyi, Skolivskyi, Stryiskyi, Tukhlyanskyi deaneries. During the study, the methods of comparison, classification and reconstruction of seals were used. Due to the comparison of seals, it was concluded that some seals were replaced. There are statistics on the authenticity of this sphragistic source in the conclusions. These seals can be a valuable source for special historical disciplines, as well as for research into the development of the Ukrainian language, local and church history, and other aspects of the social life of Galicia in the XIX–XX centuries. But there are 9 % of undefined images of parish seals in the album. About 4 % of the seals are errors or substitutions. However, these shortcomings also contain some information about the attitude of seal owners to their use. There are four types of seals in the album: emblematic, hagiographic, titular, onomastic. The most common symbol on seals is the cross. There are four ver-sions of the cross on deanery seals (mostly accompanied by a hat with tassels), and there are eleven versions on parish seals. Hagiographic images on the seals most often reflect the name of the church, although there are cases in the album of inconsistencies between the image on the seal and the name of the church. Keywords: sphragistics, parish seals, Galicia, A. Sheptytsky, anniversary album, critique of sphragistic sources.
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COŞKUN, İsmail, and Yenal SÜRÜN. "URUK SEALS OF EASTERN ANATOLIA: ARCHAEOLOGICAL FINDINGS AND INTERPRETATIONS." SOCIAL SCIENCE DEVELOPMENT JOURNAL 8, no. 38 (July 15, 2023): 120–29. http://dx.doi.org/10.31567/ssd.955.
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The phase after the Ubaid Period in Mesopotamia is called the Uruk Period. This culture coincides with the Chalcolithic Period of Eastern Anatolia. During the Uruk Period, Mesopotamia developed agriculturally. However, due to its insufficiency in terms of natural resources such as minerals and timber, they established a trade strategy centered on Eastern Anatolia, especially in the 4th millennium BC. One of the most important evidences of this trade system is seals. Made of various materials such as stone, metal, wood, glass, bone, faience and clay, seals can be of various types including stamp, cylinder and stamp-cylinder. Seals with functions such as ornamentation, protection from evil forces, confirmation and security were unearthed at Çatalhöyük in the Neolithic Period in Anatolia. Seals from the Uruk Period were also found in centers such as Elazığ-Norşuntepe and Çınaz Höyük and Malatya-Arslantepe in the Eastern Anatolia Region. While the seals of Elazığ-Norşuntepe and Çınaz Höyük consist of stamp seals, Malatya-Arslantepe has cylinder seals as well as stamp seals. The stamp seals found at Norşuntepe and Çınaz Höyük are predominantly round stamps, but there are also square stamps. Geometric motifs and stylized animal figures were used as decoration elements. They usually have round rope holes on the back. The stamp seals from Malatya-Arslantepe are round in shape. Geometric motifs and stylized depictions of humans, snakes, rams, deer and mixed creatures are found on this type of seals. In addition to stamp seals, there are also cylinder seals at Arslantepe. This type of seals mostly depict agricultural activities. They depict people plowing fields with oxen pulling the plow. Although the seals found in the mentioned centers are similar in form, they show some differences in terms of decoration. However, it is possible to say that all the examples are influenced by the seals of the Uruk Period in terms of decoration and subject matter.
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Svetocheva, Olga N., and Vladislav N. Svetochev. "Analysis of seasonality in trophic relationships of true seals (Phocideae) in the White Sea." Czech Polar Reports 5, no. 2 (June 1, 2015): 230–40. http://dx.doi.org/10.5817/cpr2015-2-20.
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The analysis of interspecific trophic relations of true seals in the White Sea on the basis of long-term study, done on feeding, is shown. Main finding is that the ringed and bearded seals have no competitive interrelations. Contrastingly, the harp seal had an impact on background seals, intensity of the competition was, however, insignificant due of harp seal seasonal stay in the White Sea. The ice-free seals, i.e. grey and harbor seals, did not show a trophic competition with ice-liking seals thanks to seasonality of stay in the White Sea and insignificant number. The trophic competition of these seals to other pinnipeds is possible at restoration of areas.
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Chupp, R. E., and C. A. Dowler. "Performance Characteristics of Brush Seals for Limited-Life Engines." Journal of Engineering for Gas Turbines and Power 115, no. 2 (April 1, 1993): 390–96. http://dx.doi.org/10.1115/1.2906721.
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Brush seals are potential replacements for air-to-air labyrinth seals in gas turbine engines. An investigation has been conducted to determine the performance characteristics of brush seals for application in limited-life gas turbine engines. An elevated temperature, rotating test rig was designed and built to test labyrinth and brush seals in simulated subsonic and supersonic engine conditions. Results from initial tests for subsonic applications demonstrated that brush seals exhibit appreciably lower leakage compared to labyrinth seals, and thus offer significant engine performance improvements. Performance results have been obtained showing the effect of various brush seal parameters, including: initial interference, backplate gap, and multiple brush seals in series.
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Kanki, H., and T. Kawakami. "Experimental Study on the Static and Dynamic Characteristics of Screw Grooved Seals." Journal of Vibration and Acoustics 110, no. 3 (July 1, 1988): 326–31. http://dx.doi.org/10.1115/1.3269520.
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Screw grooved annular seals are used in many heavy duty pumps such as boiler feed pumps. These annular seals have a significant effect on rotordynamic characteristics of the pumps. Studies on the dynamic characteristics of plain and circumferentially grooved annular seals have been published by many researchers. However, published works on screw grooved seals are few, and pump designers have not fully recognized the basic characteristics of screw grooved seals. Extensive experimental studies have been conducted for determining the basic characteristics of screw grooved seals. The leakage characteristics, load capacity, and dynamic characteristics for rotordynamic analysis were determined by using a specially designed test facility and test method. The test results were compared to the results of plain seals [3] and the basic differences were extracted for effective application of screw grooved seals.
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McCormack, Edward, Mark Jensen, and Al Hovde. "Evaluating the Use of Electronic Door Seals (E-Seals) on Shipping Containers." International Journal of Applied Logistics 1, no. 4 (October 2010): 13–29. http://dx.doi.org/10.4018/jal.2010100102.
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In this study, electronic door seals (E-seals) are tested on shipping containers that traveled through ports, over borders, and on roadways. The findings show that using RFID devices increases supply chain efficiency and improves the security of containerized cargo movements, particularly when E-seals replace common mechanical seals. Before the benefits of E-seals can be realized, several barriers must be addressed. A lack of frequency standards for E-seals is a major problem, hindering their acceptability for global trade. Routine use of E-seals also requires new processes that may slow their acceptance by the shipping industry. Disposable E-seals, which decrease industry concerns about costs and enforcement agency concerns about security by eliminating the need to recycle E-seals, are not common because they must be manufactured in large quantities to be cost effective. Compatibility with existing highway systems could also promote E-seal acceptance, as containers could be tracked on roadways.
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Southwell, Colin J., Charles G. M. Paxton, David L. Borchers, Peter L. Boveng, Erling S. Nordøy, Arnoldus Schytte Blix, and William K. De La Mare. "Estimating population status under conditions of uncertainty: the Ross seal in East Antarctica." Antarctic Science 20, no. 2 (January 4, 2008): 123–33. http://dx.doi.org/10.1017/s0954102007000879.
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AbstractThe Ross seal (Ommatophoca rossii) is the least studied of the Antarctic ice-breeding phocids. In particular, estimating the population status of the Ross seal has proved extremely difficult. The Protocol on Environmental Protection to the Antarctic Treaty currently designates the Ross seal as a ‘Specially Protected Species’, contrasting with the IUCN's classification of ‘Least Concern’. As part of a review of the Ross seal's classification under the Protocol, a survey was undertaken in 1999/2000 to estimate the status of the Ross seal population in the pack ice off East Antarctica between 64–150°E. Shipboard and aerial sighting surveys were carried out along 9476 km of transect to estimate the density of Ross seals hauled out on the ice, and satellite dive recorders deployed on a sample of Ross seals to estimate the proportion of time spent on the ice. The survey design and analysis addressed the many sources of uncertainty in estimating the abundance of this species in an effort to provide a range of best and plausible estimates. Best estimates of abundance in the survey region ranged from 41 300–55 900 seals. Limits on plausible estimates ranged from 20 500 (lower 2.5 percentile) to 226 600 (upper 97.5 percentile).
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Osinga, Nynke, and Pieter ‘t Hart. "Harbour seals (Phoca vitulina) and rehabilitation." NAMMCO Scientific Publications 8 (September 1, 2010): 355. http://dx.doi.org/10.7557/3.2699.
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Throughout the past few decades, rehabilitation of seals has become an activity that is anchored in the present day society of many countries. Seals are primarily rehabilitated to help individual animals in distress. At the same time, the release of seals which would have otherwise died can be considered as a contribution to the population. Most rehabilitated seals are animals under one year of age. They are mainly orphans, weaned seals with complications and seals with a parasiticbronchopneumonia. For the optimal handling of seals and their diseases, centralised operations with quality standards are essential. Rehabilitation provides an instrument to monitor the health of the seal population and its ecosystem. Changes in stranding trends or the appearance of new diseases can be monitored. Moreover, rehabilitation is important to show the general public thestate of the marine environment. In the Netherlands there is significant social support for the rehabilitation of seals. Experience obtained with seal care is of importance in countries where urgent help of threatened seal species is required. Here individual seals are also ambassadors to raise support for the protection of this species in general. Given that the anthropogenic impact on the seals and their environment is extensive in the Wadden Sea, rehabilitation centres can compensate the consequences of this impact on individual seals as well as the population as a whole.