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Sample records for aquatic suction feeding

  1. Hydroponic Feed With Suction

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    Cox, William M.; Brown, Christopher S.; Dreschel, Thomas W.

    1994-01-01

    Placing nutrient solution under suction increases growth. Foam plug seals growing stem of plant, making it possible to maintain suction in nutrient liquid around roots. Jar wrapped in black tape to keep out light. Potential use in terrestrial applications in arid climates or in labor-intensive agricultural situations.

  2. An integrative modeling approach to elucidate suction-feeding performance.

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    Holzman, Roi; Collar, David C; Mehta, Rita S; Wainwright, Peter C

    2012-01-01

    Research on suction-feeding performance has mostly focused on measuring individual underlying components such as suction pressure, flow velocity, ram or the effects of suction-induced forces on prey movement during feeding. Although this body of work has advanced our understanding of aquatic feeding, no consensus has yet emerged on how to combine all of these variables to predict prey-capture performance. Here, we treated the aquatic predator-prey encounter as a hydrodynamic interaction between a solid particle (representing the prey) and the unsteady suction flows around it, to integrate the effects of morphology, physiology, skull kinematics, ram and fluid mechanics on suction-feeding performance. We developed the suction-induced force-field (SIFF) model to study suction-feeding performance in 18 species of centrarchid fishes, and asked what morphological and functional traits underlie the evolution of feeding performance on three types of prey. Performance gradients obtained using SIFF revealed that different trait combinations contribute to the ability to feed on attached, evasive and (strain-sensitive) zooplanktonic prey because these prey types impose different challenges on the predator. The low overlap in the importance of different traits in determining performance also indicated that the evolution of suction-feeding ability along different ecological axes is largely unconstrained. SIFF also yielded estimates of feeding ability that performed better than kinematic traits in explaining natural patterns of prey use. When compared with principal components describing variation in the kinematics of suction-feeding events, SIFF output explained significantly more variation in centrarchid diets, suggesting that the inclusion of more mechanistic hydrodynamic models holds promise for gaining insight into the evolution of aquatic feeding performance.

  3. Swimming muscles power suction feeding in largemouth bass.

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    Camp, Ariel L; Roberts, Thomas J; Brainerd, Elizabeth L

    2015-07-14

    Most aquatic vertebrates use suction to capture food, relying on rapid expansion of the mouth cavity to accelerate water and food into the mouth. In ray-finned fishes, mouth expansion is both fast and forceful, and therefore requires considerable power. However, the cranial muscles of these fishes are relatively small and may not be able to produce enough power for suction expansion. The axial swimming muscles of these fishes also attach to the feeding apparatus and have the potential to generate mouth expansion. Because of their large size, these axial muscles could contribute substantial power to suction feeding. To determine whether suction feeding is powered primarily by axial muscles, we measured the power required for suction expansion in largemouth bass and compared it to the power capacities of the axial and cranial muscles. Using X-ray reconstruction of moving morphology (XROMM), we generated 3D animations of the mouth skeleton and created a dynamic digital endocast to measure the rate of mouth volume expansion. This time-resolved expansion rate was combined with intraoral pressure recordings to calculate the instantaneous power required for suction feeding. Peak expansion powers for all but the weakest strikes far exceeded the maximum power capacity of the cranial muscles. The axial muscles did not merely contribute but were the primary source of suction expansion power and generated up to 95% of peak expansion power. The recruitment of axial muscle power may have been crucial for the evolution of high-power suction feeding in ray-finned fishes.

  4. Origins, Innovations, and Diversification of Suction Feeding in Vertebrates.

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    Wainwright, Peter C; McGee, Matthew D; Longo, Sarah J; Hernandez, L Patricia

    2015-07-01

    We review the origins, prominent innovations, and major patterns of diversification in suction feeding by vertebrates. Non-vertebrate chordates and larval lamprey suspension-feed by capturing small particles in pharyngeal mucous. In most of these lineages the gentle flows that transport particles are generated by buccal cilia, although larval lamprey and thaliacean urochordates have independently evolved a weak buccal pump to generate an oscillating flow of water that is powered by elastic recovery of the pharynx following compression by buccal muscles. The evolution of jaws and the hyoid facilitated powerful buccal expansion and high-performance suction feeding as found today throughout aquatic vertebrates. We highlight three major innovations in suction feeding. Most vertebrate suction feeders have mechanisms that occlude the corners of the open mouth during feeding. This produces a planar opening that is often nearly circular in shape. Both features contribute to efficient flow of water into the mouth and help direct the flow to the area directly in front of the mouth's aperture. Among several functions that have been identified for protrusion of the upper jaw, is an increase in the hydrodynamic forces that suction feeders exert on their prey. Protrusion of the upper jaw has evolved five times in ray-finned fishes, including in two of the most successful teleost radiations, cypriniforms and acanthomorphs, and is found in about 60% of living teleost species. Diversification of the mechanisms of suction feeding and of feeding behavior reveals that suction feeders with high capacity for suction rarely approach their prey rapidly, while slender-bodied predators with low capacity for suction show the full range of attack speeds. We hypothesize that a dominant axis of diversification among suction feeders involves a trade-off between the forces that are exerted on prey and the volume of water that is ingested.

  5. Hydrodynamics of suction feeding in fish

    NARCIS (Netherlands)

    Muller, M.

    1983-01-01

    1. Suction feeding is the dominant way to obtain food in teleosts. Its high demands on structures due to the required velocities and forces leads to the expectation that a biophysical analysis will aid to reveal the adaptive significance of head and body structures related to this action.2. A main f

  6. Suction, Ram, and Biting: Deviations and Limitations to the Capture of Aquatic Prey.

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    Ferry, Lara A; Paig-Tran, E Misty; Gibb, Alice C

    2015-07-01

    When feeding, most aquatic organisms generate suction that draws prey into the mouth. The papers in this volume are a demonstration of this fact. However, under what circumstances is suction ineffective as a feeding mechanism? Here we consider the interplay between suction, ram, and biting, and analyze the contribution of each to the capture of prey by a wide variety of species of fish. We find, not surprisingly, that ram is the dominant contributor to feeding because suction, and biting, are only effective when very close to the prey. As species utilize more strongly ram-dominated modes of feeding, they may be released from the morphological and behavioral constraints associated with the need to direct a current of water into the head. Morphological and behavioral changes that facilitate larger gapes and stronger jaws are explored here, including predators that lack a protrusile upper jaw, predators with elongate jaws, predators that rely on suspension feeding, and predators that bite. Interestingly, while the mobility of the jaws and the shape of the opening of the mouth are modified in species that have departed from a primary reliance on suction feeding, the anterior-to-posterior wave of expansion persists. This wave may be greatly slowed in ram and biting species, but its retention suggests a fundamental importance to aquatic feeding.

  7. Independent Evolution of Suction Feeding in Neobatrachia: Feeding Mechanisms in Two Species of Telmatobius (Anura:Telmatobiidae).

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    Barrionuevo, José Sebastián

    2016-02-01

    The most common feeding mechanism among aquatic vertebrates as fishes, turtles, and salamanders is inertial suction. However, among the more than 6,400 species of anurans, suction feeding occurs only in pipids. Pipidae is a small basal lineage relative to Neobatrachia, an enormous clade that contains about 96% of extant anurans. The Andean neobatrachian frogs of the genus Telmatobius include strictly aquatic and semiaquatic species. Diet analyses indicate that some species of Telmatobius feed on strictly aquatic prey, but until now their feeding mechanisms have been unknown. Herein, the feeding mechanisms in two species of Telmatobius, that represent the two predominant modes of life in the genus, are explored. The semiaquatic T. oxycephalus and the fully aquatic T. rubigo are studied using high-speed cinematography and standard anatomical techniques to provide a qualitative approach to feeding behavior and a detailed morphological description of the mouth, tongue, hyoid and related muscles. T. oxycephalus uses similar mechanisms of aquatic prey capture as do the vast majority of anurans that are capable of forage in water, whereas the fully aquatic T. rubigo is an inertial suction feeder. This is the first report of an objective record of this unique feeding behavior in a Neobatrachian. Several morphological characters seem to be related with this function and are convergent with those of pipids.

  8. Feeding kinematics, suction, and hydraulic jetting performance of harbor seals (Phoca vitulina).

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    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; Pfeeding 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; Pforce 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, generalized feeding ecology and concomitant breadth of diet.

  9. Body ram, not suction, is the primary axis of suction-feeding diversity in spiny-rayed fishes.

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    Longo, Sarah J; McGee, Matthew D; Oufiero, Christopher E; Waltzek, Thomas B; Wainwright, Peter C

    2016-01-01

    Suction-feeding fishes exhibit diverse prey-capture strategies that vary in their relative use of suction and predator approach (ram), which is often referred to as the ram-suction continuum. Previous research has found that ram varies more than suction distance among species, such that ram accounts for most differences in prey-capture behaviors. To determine whether these findings hold at broad evolutionary scales, we collected high-speed videos of 40 species of spiny-rayed fishes (Acanthomorpha) feeding on live prey. For each strike, we calculated the contributions of suction, body ram (swimming) and jaw ram (mouth movement relative to the body) to closing the distance between predator and prey. We confirm that the contribution of suction distance is limited even in this phylogenetically and ecologically broad sample of species, with the extreme suction area of prey-capture space conspicuously unoccupied. Instead of a continuum from suction to ram, we find that variation in body ram is the major factor underlying the diversity of prey-capture strategies among suction-feeding fishes. Independent measurement of the contribution of jaw ram revealed that it is an important component of diversity among spiny-rayed fishes, with a number of ecomorphologies relying heavily on jaw ram, including pivot feeding in syngnathiforms, extreme jaw protruders and benthic sit-and-wait ambush predators. A combination of morphological and behavioral innovations has allowed fish to invade the extreme jaw ram area of prey-capture space. We caution that while two-species comparisons may support a ram-suction trade-off, these patterns do not speak to broader patterns across spiny-rayed fishes.

  10. A giant chelonioid turtle from the late Cretaceous of Morocco with a suction feeding apparatus unique among tetrapods.

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    Nathalie Bardet

    Full Text Available BACKGROUND: Secondary adaptation to aquatic life occurred independently in several amniote lineages, including reptiles during the Mesozoic and mammals during the Cenozoic. These evolutionary shifts to aquatic environments imply major morphological modifications, especially of the feeding apparatus. Mesozoic (250-65 Myr marine reptiles, such as ichthyosaurs, plesiosaurs, mosasaurid squamates, crocodiles, and turtles, exhibit a wide range of adaptations to aquatic feeding and a broad overlap of their tooth morphospaces with those of Cenozoic marine mammals. However, despite these multiple feeding behavior convergences, suction feeding, though being a common feeding strategy in aquatic vertebrates and in marine mammals in particular, has been extremely rarely reported for Mesozoic marine reptiles. PRINCIPAL FINDINGS: A relative of fossil protostegid and dermochelyoid sea turtles, Ocepechelon bouyai gen. et sp. nov. is a new giant chelonioid from the Late Maastrichtian (67 Myr of Morocco exhibiting remarkable adaptations to marine life (among others, very dorsally and posteriorly located nostrils. The 70-cm-long skull of Ocepechelon not only makes it one of the largest marine turtles ever described, but also deviates significantly from typical turtle cranial morphology. It shares unique convergences with both syngnathid fishes (unique long tubular bony snout ending in a rounded and anteriorly directed mouth and beaked whales (large size and elongated edentulous jaws. This striking anatomy suggests extreme adaptation for suction feeding unmatched among known turtles. CONCLUSION/SIGNIFICANCE: The feeding apparatus of Ocepechelon, a bony pipette-like snout, is unique among tetrapods. This new taxon exemplifies the successful systematic and ecological diversification of chelonioid turtles during the Late Cretaceous. This new evidence for a unique trophic specialization in turtles, along with the abundant marine vertebrate faunas associated to

  11. Characterization of zebrafish larvae suction feeding flow using μPIV and optical coherence tomography

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    Pekkan, Kerem; Chang, Brian; Uslu, Fazil; Mani, Karthick; Chen, Chia-Yuan; Holzman, Roi

    2016-07-01

    The hydrodynamics of suction feeding is critical for the survival of fish larvae; failure to capture food during the onset of autonomous feeding can rapidly lead to starvation and mortality. Fluid mechanics experiments that investigate the suction feeding of suspended particles are limited to adult fishes, which operate at large Reynolds numbers. This manuscript presents the first literature results in which the external velocity fields generated during suction feeding of early zebrafish larvae (2500-20,000 μm total length) are reported using time-resolved microscopic particle image velocimetry. For the larval stages studied, the maximum peak suction velocity of the inflow bolus is measured at a finite distance from the mouth tip and ranges from 1 to 8 mm/s. The average pressure gradient and the velocity profile proximal to the buccal (mouth) cavity are calculated, and two distinct trends are identified. External recirculation regions and reverse flow feeding cycles are also observed and quantified. One of the unresolved questions in fish suction feeding is the shape and dynamics of the buccal cavity during suction feeding; optical coherence tomography imaging is found to be useful for reconstructing the mouth kinematics. The projected area of the mouth cavity during the feeding cycle varies up to 160 and 22 % for the transverse and mid-sagittal planes, respectively. These findings can inspire novel hydrodynamically efficient biomedical and microfluidic devices.

  12. Absence of suction feeding ichthyosaurs and its implications for triassic mesopelagic paleoecology.

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    Motani, Ryosuke; Ji, Cheng; Tomita, Taketeru; Kelley, Neil; Maxwell, Erin; Jiang, Da-yong; Sander, Paul Martin

    2013-01-01

    Mesozoic marine reptiles and modern marine mammals are often considered ecological analogs, but the extent of their similarity is largely unknown. Particularly important is the presence/absence of deep-diving suction feeders among Mesozoic marine reptiles because this would indicate the establishment of mesopelagic cephalopod and fish communities in the Mesozoic. A recent study suggested that diverse suction feeders, resembling the extant beaked whales, evolved among ichthyosaurs in the Triassic. However, this hypothesis has not been tested quantitatively. We examined four osteological features of jawed vertebrates that are closely linked to the mechanism of suction feeding, namely hyoid corpus ossification/calcification, hyobranchial apparatus robustness, mandibular bluntness, and mandibular pressure concentration index. Measurements were taken from 18 species of Triassic and Early Jurassic ichthyosaurs, including the presumed suction feeders. Statistical comparisons with extant sharks and marine mammals of known diets suggest that ichthyosaurian hyobranchial bones are significantly more slender than in suction-feeding sharks or cetaceans but similar to those of ram-feeding sharks. Most importantly, an ossified hyoid corpus to which hyoid retractor muscles attach is unknown in all but one ichthyosaur, whereas a strong integration of the ossified corpus and cornua of the hyobranchial apparatus has been identified in the literature as an important feature of suction feeders. Also, ichthyosaurian mandibles do not narrow rapidly to allow high suction pressure concentration within the oral cavity, unlike in beaked whales or sperm whales. In conclusion, it is most likely that Triassic and Early Jurassic ichthyosaurs were 'ram-feeders', without any beaked-whale-like suction feeder among them. When combined with the inferred inability for dim-light vision in relevant Triassic ichthyosaurs, the fossil record of ichthyosaurs does not suggest the establishment of modern

  13. Absence of suction feeding ichthyosaurs and its implications for triassic mesopelagic paleoecology.

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    Ryosuke Motani

    Full Text Available Mesozoic marine reptiles and modern marine mammals are often considered ecological analogs, but the extent of their similarity is largely unknown. Particularly important is the presence/absence of deep-diving suction feeders among Mesozoic marine reptiles because this would indicate the establishment of mesopelagic cephalopod and fish communities in the Mesozoic. A recent study suggested that diverse suction feeders, resembling the extant beaked whales, evolved among ichthyosaurs in the Triassic. However, this hypothesis has not been tested quantitatively. We examined four osteological features of jawed vertebrates that are closely linked to the mechanism of suction feeding, namely hyoid corpus ossification/calcification, hyobranchial apparatus robustness, mandibular bluntness, and mandibular pressure concentration index. Measurements were taken from 18 species of Triassic and Early Jurassic ichthyosaurs, including the presumed suction feeders. Statistical comparisons with extant sharks and marine mammals of known diets suggest that ichthyosaurian hyobranchial bones are significantly more slender than in suction-feeding sharks or cetaceans but similar to those of ram-feeding sharks. Most importantly, an ossified hyoid corpus to which hyoid retractor muscles attach is unknown in all but one ichthyosaur, whereas a strong integration of the ossified corpus and cornua of the hyobranchial apparatus has been identified in the literature as an important feature of suction feeders. Also, ichthyosaurian mandibles do not narrow rapidly to allow high suction pressure concentration within the oral cavity, unlike in beaked whales or sperm whales. In conclusion, it is most likely that Triassic and Early Jurassic ichthyosaurs were 'ram-feeders', without any beaked-whale-like suction feeder among them. When combined with the inferred inability for dim-light vision in relevant Triassic ichthyosaurs, the fossil record of ichthyosaurs does not suggest the

  14. Role of axial muscles in powering mouth expansion during suction feeding in largemouth bass (Micropterus salmoides).

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    Camp, Ariel L; Brainerd, Elizabeth L

    2014-04-15

    Suction-feeding fishes capture food by fast and forceful expansion of the mouth cavity, and axial muscles probably provide substantial power for this feeding behavior. Dorsal expansion of the mouth cavity can only be powered by the epaxial muscles, but both the sternohyoid, shortening against an immobile pectoral girdle to retract the hyoid, and the hypaxial muscles, shortening to retract both the pectoral girdle and hyoid, could contribute ventral expansion power. To determine whether hypaxial muscles generate power for ventral expansion, and the rostrocaudal extent of axial muscle shortening during suction feeding, we measured skeletal kinematics and muscle shortening in largemouth bass (Micropterus salmoides). The three-dimensional motions of the cleithrum and hyoid were measured with X-ray reconstruction of moving morphology (XROMM), and muscle shortening was measured with fluoromicrometry, wherein changes in the distance between radio-opaque intramuscular markers are measured using biplanar X-ray video recording. We found that the hypaxials generated power for ventral suction expansion, shortening (mean of 6.2 mm) to rotate the pectoral girdle caudoventrally (mean of 9.3 deg) and retract the hyoid (mean of 8.5 mm). In contrast, the sternohyoid shortened minimally (mean of 0.48 mm), functioning like a ligament to transmit hypaxial shortening to the hyoid. Hypaxial and epaxial shortening were not confined to the rostral muscle regions, but extended more than halfway down the body during suction expansion. We conclude that hypaxial and epaxial muscles are both crucial for powering mouth expansion in largemouth bass, supporting the integration of axial and cranial musculoskeletal systems for suction feeding.

  15. Kinematics of benthic suction feeding in Callichthyidae and Mochokidae, with functional implications for the evolution of food scraping in catfishes.

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    Van Wassenbergh, Sam; Lieben, Tim; Herrel, Anthony; Huysentruyt, Frank; Geerinckx, Tom; Adriaens, Dominique; Aerts, Peter

    2009-01-01

    Food scraping has independently evolved twice from suction feeding in the evolution of catfishes: within neotropical Loricarioidea and paleotropical Mochokidae. To gain insight in the evolutionary transitions associated with the evolution towards scraping, we analyzed prey capture kinematics in two species of benthic suction feeders which belong to taxa that are closely related to the scraper lineages (respectively, Corydoras splendens and Synodontis multipunctatus), and compared it to prey capture in a more distantly related, generalist suction feeder (Clarias gariepinus). Simultaneous ventral and lateral view high-speed videos were recorded to quantify the movements of the lower jaw, hyoid, pectoral girdle and neurocranium. Additionally, ellipse modeling was applied to relate head shape differences to buccal expansion kinematics. Similarly to what has been observed in scrapers, rotations of the neurocranium are minimal in the benthic suction feeders, and may consequently have facilitated the evolution of a scraping feeding mechanism. The hypothesis that fish with a more laterally compressed head rely more heavily on lateral expansion of the buccal cavity to generate suction, was confirmed in our sample of catfish species. Since an important contribution of lateral expansion of the head to suction may avoid the need for a strong, ventral depression of the mouth floor during feeding, we hypothesized that this may have allowed a closer association with the substrate in the ancestors of scrapers. However, our hypothesis was not supported by an ancestral state reconstruction, which suggests that scraping probably evolved from sub-terminal mouthed ancestors with dorsoventrally flattened heads.

  16. Time management and nectar flow: flower handling and suction feeding in long-proboscid flies (Nemestrinidae: Prosoeca)

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    Karolyi, Florian; Morawetz, Linde; Colville, Jonathan F.; Handschuh, Stephan; Metscher, Brian D.; Krenn, Harald W.

    2013-11-01

    A well-developed suction pump in the head represents an important adaptation for nectar-feeding insects, such as Hymenoptera, Lepidoptera and Diptera. This pumping organ creates a pressure gradient along the proboscis, which is responsible for nectar uptake. The extremely elongated proboscis of the genus Prosoeca (Nemestrinidae) evolved as an adaptation to feeding from long, tubular flowers. According to the functional constraint hypothesis, nectar uptake through a disproportionately elongated, straw-like proboscis increases flower handling time and consequently lowers the energy intake rate. Due to the conspicuous length variation of the proboscis of Prosoeca, individuals with longer proboscides are hypothesised to have longer handling times. To test this hypothesis, we used field video analyses of flower-visiting behaviour, detailed examinations of the suction pump morphology and correlations of proboscis length with body length and suction pump dimensions. Using a biomechanical framework described for nectar-feeding Lepidoptera in relation to proboscis length and suction pump musculature, we describe and contrast the system in long-proboscid flies. Flies with longer proboscides spent significantly more time drinking from flowers. In addition, proboscis length and body length showed a positive allometric relationship. Furthermore, adaptations of the suction pump included an allometric relationship between proboscis length and suction pump muscle volume and a combination of two pumping organs. Overall, the study gives detailed insight into the adaptations required for long-proboscid nectar feeding, and comparisons with other nectar-sucking insects allow further considerations of the evolution of the suction pump in insects with sucking mouthparts.

  17. Timing is everything: coordination of strike kinematics affects the force exerted by suction feeding fish on attached prey.

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    Holzman, Roi; Day, Steven W; Wainwright, Peter C

    2007-10-01

    During aquatic suction feeding, the predator opens its mouth and rapidly expands its buccal cavity, generating a flow field external to the mouth. The rapid expansion of the buccal cavity produces high fluid velocities and accelerations that extend only a short distance from the mouth (about half of one mouth diameter), and only persist for several milliseconds. Therefore, the predator must precisely time its strike to locate the prey within the narrow region of high flow, during the brief period when flow is at its peak. With flow being the agent for transferring force to the prey, the predator may enhance these forces by producing higher water velocities and faster acceleration at the mouth, but also through increasing the strike's accuracy, i.e. locating the prey closer to the mouth at the instant of peak flow speed. The objectives of this study were to directly measure forces exerted by bluegill Lepomis macrochirus on their prey and to determine how bluegill modify force output. Bluegill were offered ghost shrimp tethered to a load cell that recorded force at 5000 Hz, and feeding sequences were synchronously recorded using 500 Hz video. Peak forces exerted on attached 20 mm shrimp ranged from 0.005 N to 0.506 N. In accordance with the short duration of the strikes (average time to peak gape of approximately 13 ms), the forces recorded were brief (approximately 12 ms from initiation to peak force), and force magnitude declined rapidly after peak force. Statistical analysis indicated that rate of buccal expansion, and prey size, but not strike initiation distance, significantly affected peak force. These observed variables were used with results from flow visualization studies to estimate the flow at the prey's location, which allowed the calculation of drag, pressure gradient force and acceleration reaction force. The relationship between these calculated forces and the measured forces was strong, indicating that the model can be used to estimate forces from

  18. Australian fur seals (Arctocephalus pusillus doriferus use raptorial biting and suction feeding when targeting prey in different foraging scenarios.

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    David P Hocking

    Full Text Available Foraging behaviours used by two female Australian fur seals (Arctocephalus pusillus doriferus were documented during controlled feeding trials. During these trials the seals were presented with prey either free-floating in open water or concealed within a mobile ball or a static box feeding device. When targeting free-floating prey both subjects primarily used raptorial biting in combination with suction, which was used to draw prey to within range of the teeth. When targeting prey concealed within either the mobile or static feeding device, the seals were able to use suction to draw out prey items that could not be reached by biting. Suction was followed by lateral water expulsion, where water drawn into the mouth along with the prey item was purged via the sides of the mouth. Vibrissae were used to explore the surface of the feeding devices, especially when locating the openings in which the prey items had been hidden. The mobile ball device was also manipulated by pushing it with the muzzle to knock out concealed prey, which was not possible when using the static feeding device. To knock prey out of this static device one seal used targeted bubble blowing, where a focused stream of bubbles was blown out of the nose into the openings in the device. Once captured in the jaws, prey items were manipulated and re-oriented using further mouth movements or chews so that they could be swallowed head first. While most items were swallowed whole underwater, some were instead taken to the surface and held in the teeth, while being vigorously shaken to break them into smaller pieces before swallowing. The behavioural flexibility displayed by Australian fur seals likely assists in capturing and consuming the extremely wide range of prey types that are targeted in the wild, during both benthic and epipelagic foraging.

  19. New fossil insect order Permopsocida elucidates major radiation and evolution of suction feeding in hemimetabolous insects (Hexapoda: Acercaria)

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    Huang, Di-Ying; Bechly, Günter; Nel, Patricia; Engel, Michael S.; Prokop, Jakub; Azar, Dany; Cai, Chen-Yang; van de Kamp, Thomas; Staniczek, Arnold H.; Garrouste, Romain; Krogmann, Lars; Dos Santos Rolo, Tomy; Baumbach, Tilo; Ohlhoff, Rainer; Shmakov, Alexey S.; Bourgoin, Thierry; Nel, André

    2016-03-01

    With nearly 100,000 species, the Acercaria (lice, plant lices, thrips, bugs) including number of economically important species is one of the most successful insect lineages. However, its phylogeny and evolution of mouthparts among other issues remain debatable. Here new methods of preparation permitted the comprehensive anatomical description of insect inclusions from mid-Cretaceous Burmese amber in astonishing detail. These “missing links” fossils, attributed to a new order Permopsocida, provide crucial evidence for reconstructing the phylogenetic relationships in the Acercaria, supporting its monophyly, and questioning the position of Psocodea as sister group of holometabolans in the most recent phylogenomic study. Permopsocida resolves as sister group of Thripida + Hemiptera and represents an evolutionary link documenting the transition from chewing to piercing mouthparts in relation to suction feeding. Identification of gut contents as angiosperm pollen documents an ecological role of Permopsocida as early pollen feeders with relatively unspecialized mouthparts. This group existed for 185 million years, but has never been diverse and was superseded by new pollenivorous pollinators during the Cretaceous co-evolution of insects and flowers. The key innovation of suction feeding with piercing mouthparts is identified as main event that triggered the huge post-Carboniferous radiation of hemipterans, and facilitated the spreading of pathogenic vectors.

  20. Anterior-to-posterior wave of buccal expansion in suction feeding fishes is critical for optimizing fluid flow velocity profile.

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    Bishop, Kristin L; Wainwright, Peter C; Holzman, Roi

    2008-11-01

    In fishes that employ suction feeding, coordinating the timing of peak flow velocity with mouth opening is likely to be an important feature of prey capture success because this will allow the highest forces to be exerted on prey items when the jaws are fully extended and the flow field is at its largest. Although it has long been known that kinematics of buccal expansion in feeding fishes are characterized by an anterior-to-posterior wave of expansion, this pattern has not been incorporated in most previous computational models of suction feeding. As a consequence, these models have failed to correctly predict the timing of peak flow velocity, which according to the currently available empirical data should occur around the time of peak gape. In this study, we use a simple fluid dynamic model to demonstrate that the inclusion of an anterior-to-posterior wave of buccal expansion can correctly reproduce the empirically determined flow velocity profile, although only under very constrained conditions, whereas models that do not allow this wave of expansion inevitably predict peak velocity earlier in the strike, when the gape is less than half of its maximum. The conditions that are required to produce a realistic velocity profile are as follows: (i) a relatively long time lag between mouth opening and expansion of the more posterior parts of the mouth, (ii) a short anterior portion of the mouth relative to more posterior sections, and (iii) a pattern of movement that begins slowly and then rapidly accelerates. Greater maximum velocities were generated in simulations without the anterior-to-posterior wave of expansion, suggesting a trade-off between maximizing fluid speed and coordination of peak fluid speed with peak gape.

  1. Mechanics of snout expansion in suction-feeding seahorses: musculoskeletal force transmission.

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    Van Wassenbergh, Sam; Leysen, Heleen; Adriaens, Dominique; Aerts, Peter

    2013-02-01

    Seahorses and other syngnathid fishes rely on a widening of the snout to create the buccal volume increase needed to suck prey into the mouth. This snout widening is caused by abduction of the suspensoria, the long and flat bones outlining the lateral sides of the mouth cavity. However, it remains unknown how seahorses can generate a forceful abduction of the suspensoria. To understand how force is transmitted to the suspensoria via the hyoid and the lower jaw, we performed mathematical simulations with models based on computerized tomography scans of Hippocampus reidi. Our results show that the hinge joint between the left and right hyoid bars, as observed in H. reidi, allows for an efficient force transmission to the suspensorium from a wide range of hyoid angles, including the extremely retracted hyoid orientations observed in vivo for syngnathids. Apart from the hyoid retraction force by the sternohyoideus-hypaxial muscles, force generated in the opposite direction on the hyoid by the mandibulohyoid ligament also has an important contribution to suspensorium abduction torque. Forces on the lower jaw contribute only approximately 10% of the total suspensorium torque. In particular, when dynamical aspects of hyoid retraction are included in the model, a steep increase is shown in suspensorium abduction torque at highly retracted hyoid positions, when the linkages to the lower jaw counteract further hyoid rotation in the sagittal plane. A delayed strain in these linkages allows syngnathids to postpone suction generation until the end of cranial rotation, a fundamental difference from non-syngnathiform fishes.

  2. Aquatic macrophytes as feeding site for small fishes in the Rosana Reservoir, Paranapanema River, southeastern Brazil.

    Science.gov (United States)

    Casatti, L; Mendes, H F; Ferreira, K M

    2003-05-01

    In the present investigation we studied the feeding habits of the fishes associated with aquatic macrophytes in the Rosana Reservoir, southeastern Brazil. Twenty fish species were collected during four field trips, regularly distributed across the dry and wet seasons. Focal snorkeling observations of the fishes were made over a total of six hours. Nine species were present in abundances of more than 1% and, therefore, had their feeding habits analyzed. Hemigrammus marginatus, Roeboides paranensis, Hyphessobrycon eques, Astyanax altiparanae, Serrasalmus spilopleura, and Bryconamericus stramineus were predominantly invertivores, with predominance of aquatic insects (Diptera, Ephemeroptera, and Trichoptera immatures) among their food items. The predominantly algivores were Apareiodon affinis, Serrapinnus notomelas, and Satanoperca pappaterra, with high frequency of filamentous blue-green algae, diatoms, clorophyts, and periderm. The different microhabitat exploitation plus diet composition suggests partitioning of resources and absence of food competition among the most representative fish species in the studied community, indicating the importance of the naturalistic approach to fish ecology studies.

  3. Suction Buckets

    DEFF Research Database (Denmark)

    Feld, T.

    on the performed numerical simulations, the analytical models and concepts like penetration resistance and critical suction. The employment of finite element calculations in the design of bucket foundation is evaluated and found necessary in the detailed design. However, introductory the determination......This Ph.D. thesis deals with bucket foundations and their applicability for offshore wind turbines. The main concern is the establishment of an analytical model for frictional materials, combined with simulations of buckets with varying geometry. An analytical model is proposed, consisting...... of different parts describing the penetration resistance during installation, the phenomenon critical suction and calculation methods for determination of the pullout force, respectively the response under combined loading, equivalent to ship impact, wave actions etc. A series of experimental tests conducted...

  4. Suction patterns in preterm infants.

    Science.gov (United States)

    Martell, M; Martínez, G; González, M; Díaz Rosselló, J L

    1993-01-01

    The suction pattern for breast and bottle feeding in two groups of preterm infants is described. The time elapsed between birth and the moment of suction was longer in preterm neonates born at lower gestational ages for both groups studied, breast and bottle fed (figure 1). The evolution of suckling in breastfeeding was analyzed in a composite study (longitudinal and transverse) in a group of 16 neonates starting from 32 weeks of gestation. The velocity of milk extraction during suckling varied with gestational age. It was uniform at lower gestational ages, then it became faster in the first minutes and at the 36th week, it was very similar to that of mature neonates (figure 2 and table I). The evaluation of bottle feeding was performed in a transverse study in 46 preterm neonates which had been exclusively bottle fed during 1 or 2 weeks. All of them had previously been fed using an orogastric tube. Nourishing time was shorter than in breastfeeding; the average duration was 3.7 minutes (table II). The greatest volume was ingested in the first minute, 40% (range between 44 and 25%) (figure 3). The frequency of suction did not change the duration of feeding, but it was found that the efficiency of suction (number of suctions to ingest 1 cc) was significantly lower in the first minute (Anova, p < 0.05) (figure 4).

  5. Does aquatic foraging impact head shape evolution in snakes?

    Science.gov (United States)

    Segall, Marion; Cornette, Raphaël; Fabre, Anne-Claire; Godoy-Diana, Ramiro; Herrel, Anthony

    2016-08-31

    Evolutionary trajectories are often biased by developmental and historical factors. However, environmental factors can also impose constraints on the evolutionary trajectories of organisms leading to convergence of morphology in similar ecological contexts. The physical properties of water impose strong constraints on aquatic feeding animals by generating pressure waves that can alert prey and potentially push them away from the mouth. These hydrodynamic constraints have resulted in the independent evolution of suction feeding in most groups of secondarily aquatic tetrapods. Despite the fact that snakes cannot use suction, they have invaded the aquatic milieu many times independently. Here, we test whether the aquatic environment has constrained head shape evolution in snakes and whether shape converges on that predicted by biomechanical models. To do so, we used three-dimensional geometric morphometrics and comparative, phylogenetically informed analyses on a large sample of aquatic snake species. Our results show that aquatic snakes partially conform to our predictions and have a narrower anterior part of the head and dorsally positioned eyes and nostrils. This morphology is observed, irrespective of the phylogenetic relationships among species, suggesting that the aquatic environment does indeed drive the evolution of head shape in snakes, thus biasing the evolutionary trajectory of this group of animals.

  6. Spatial distribution and functional feeding groups of aquatic insects in a stream of Chakrashila Wildlife Sanctuary, Assam, India

    Directory of Open Access Journals (Sweden)

    Barman B.

    2015-01-01

    Full Text Available Aquatic insects play important role in ecosystem functioning viz. nutrient cycling, primary production, decomposition and material translocation. The functional feeding group (FFG approach is an attempt to classify organisms, especially insects, according to their role in the processing of organic matter. An investigation during 2011–2013 was carried out on aquatic insects in different stretches of a stream of Chakrashila Wildlife Sanctuary located in western Assam, North East India which is designated as Key Biodiversity Area (KBA by IUCN. Physico-chemical properties of water of the stream like water temperature, dissolved oxygen, free-carbondioxide, pH, total alkalinity, electrical conductivity, phosphate and nitrate were estimated to correlate the aquatic insects of specific functional feeding groups with water quality. A total of seventeen species was recorded during the study period. Record of nine species in first year and fourteen species in second year under different functional feeding groups (FFG showed altitudinal variation. Highest percentage of predators was found in upstream. Collectors were recorded in upstream and downstream and shredders were recorded in midstream.

  7. Dining dichotomy: aquatic and terrestrial prey capture behavior in the Himalayan newt Tylototriton verrucosus

    Science.gov (United States)

    De Vylder, Marie

    2016-01-01

    ABSTRACT Transitions between aquatic and terrestrial prey capture are challenging. Trophic shifts demand a high degree of behavioral flexibility to account for different physical circumstances between water and air to keep performance in both environments. The Himalayan newt, Tylototriton verrucosus, is mostly terrestrial but becomes aquatic during its short breeding period. Nonetheless, it was assumed that it lacks the capability of trophic behavioral flexibility, only captures prey on land by its tongue (lingual prehension) and does not feed in water. This theory was challenged from stomach content analyses in wild populations that found a variety of aquatic invertebrates in the newts' stomachs during their breeding season. Accordingly, we hypothesized that T. verrucosus actively changes its terrestrial prey capture mechanism to hunt for aquatic prey at least during its aquatic stage. In fact, the kinematic analyses showed that T. verrucosus uses lingual prehension to capture prey on land but changes to suction feeding for aquatic strikes. The statistical analyses revealed that terrestrial and aquatic strikes differ significantly in most kinematic parameters while behavioral variability does not differ between both behaviors. In turn, the movement patterns in suction feeding showed a higher degree of coordination between jaw and hyoid movements compared to the putative primary feeding mode, namely lingual prehension. We conclude that T. verrucosus, though relatively slow compared to trophic specialists, benefits from a high degree of behavioral flexibility that allows exploiting food sources efficiently from two very different habitats. PMID:27612510

  8. Functional feeding groups of aquatic insect families in Latin America: a critical analysis and review of existing literature.

    Science.gov (United States)

    Ramírez, Alonso; Gutiérrez-Fonseca, Pablo E

    2014-04-01

    Aquatic macroinvertebrates are involved in numerous processes within aquatic ecosystems. They often have important effects on ecosystem processes such as primary production (via grazing), detritus breakdown, and nutrient mineralization and downstream spiraling. The functional feeding groups (FFG) classification was developed as a tool to facilitate the incorporation of macroinvertebrates in studies of aquatic ecosystems. This classification has the advantage of combining morphological characteristics (e.g., mouth part specialization) and behavioral mechanisms (e.g., way of feeding) used by macroinvertebrates when consuming resources. Although recent efforts have greatly advanced our ability to identify aquatic macroinvertebrates, there is limited information on FFG assignment. Furthermore, there has been some variation in the use of the FFG classification, in part due to an emphasis on using gut content analysis to assign FFG, which is more appropriate for assigning trophic guilds. Thus, the main goals of this study are to (1) provide an overview of the value of using the FFG classification, (2) make an initial attempt to summarize available information on FFG for aquatic insects in Latin America, and (3) provide general guidelines on how to assign organisms to their FFGs. FFGs are intended to reflect the potential effects of organisms in their ecosystems and the way they consume resources. Groups include scrapers that consume resources that grow attached to the substrate by removing them with their mouth parts; shredders that cut or chew pieces of living or dead plant material, including all plant parts like leaves and wood; collectors-gatherers that use modified mouth parts to sieve or collect small particles (< 1 mm) accumulated on the stream bottom; filterers that have special adaptations to remove particles directly from the water column; and predators that consume other organisms using different strategies to capture them. In addition, we provide details on

  9. Can sacrificial feeding areas protect aquatic plants from herbivore grazing? Using behavioural ecology to inform wildlife management.

    Science.gov (United States)

    Wood, Kevin A; Stillman, Richard A; Daunt, Francis; O'Hare, Matthew T

    2014-01-01

    Effective wildlife management is needed for conservation, economic and human well-being objectives. However, traditional population control methods are frequently ineffective, unpopular with stakeholders, may affect non-target species, and can be both expensive and impractical to implement. New methods which address these issues and offer effective wildlife management are required. We used an individual-based model to predict the efficacy of a sacrificial feeding area in preventing grazing damage by mute swans (Cygnus olor) to adjacent river vegetation of high conservation and economic value. The accuracy of model predictions was assessed by a comparison with observed field data, whilst prediction robustness was evaluated using a sensitivity analysis. We used repeated simulations to evaluate how the efficacy of the sacrificial feeding area was regulated by (i) food quantity, (ii) food quality, and (iii) the functional response of the forager. Our model gave accurate predictions of aquatic plant biomass, carrying capacity, swan mortality, swan foraging effort, and river use. Our model predicted that increased sacrificial feeding area food quantity and quality would prevent the depletion of aquatic plant biomass by swans. When the functional response for vegetation in the sacrificial feeding area was increased, the food quantity and quality in the sacrificial feeding area required to protect adjacent aquatic plants were reduced. Our study demonstrates how the insights of behavioural ecology can be used to inform wildlife management. The principles that underpin our model predictions are likely to be valid across a range of different resource-consumer interactions, emphasising the generality of our approach to the evaluation of strategies for resolving wildlife management problems.

  10. Longitudinal Distribution of the Functional Feeding Groups of Aquatic Insects in Streams of the Brazilian Cerrado Savanna.

    Science.gov (United States)

    Brasil, L S; Juen, L; Batista, J D; Pavan, M G; Cabette, H S R

    2014-10-01

    We demonstrate that the distribution of the functional feeding groups of aquatic insects is related to hierarchical patch dynamics. Patches are sites with unique environmental and functional characteristics that are discontinuously distributed in time and space within a lotic system. This distribution predicts that the occurrence of species will be based predominantly on their environmental requirements. We sampled three streams within the same drainage basin in the Brazilian Cerrado savanna, focusing on waterfalls and associated habitats (upstream, downstream), representing different functional zones. We collected 2,636 specimens representing six functional feeding groups (FFGs): brushers, collector-gatherers, collector-filterers, shredders, predators, and scrapers. The frequency of occurrence of these groups varied significantly among environments. This variation appeared to be related to the distinct characteristics of the different habitat patches, which led us to infer that the hierarchical patch dynamics model can best explain the distribution of functional feeding groups in minor lotic environments, such as waterfalls.

  11. Phenotypic flexibility of gape anatomy fine-tunes the aquatic prey-capture system of newts

    Science.gov (United States)

    van Wassenbergh, Sam; Heiss, Egon

    2016-07-01

    A unique example of phenotypic flexibility of the oral apparatus is present in newts (Salamandridae) that seasonally change between an aquatic and a terrestrial habitat. Newts grow flaps of skin between their upper and lower jaws, the labial lobes, to partly close the corners of the mouth when they adopt an aquatic lifestyle during their breeding season. Using hydrodynamic simulations based on μCT-scans and cranial kinematics during prey-capture in the smooth newt (Lissotriton vulgaris), we showed that this phenotypic flexibility is an adaptive solution to improve aquatic feeding performance: both suction distance and suction force increase by approximately 15% due to the labial lobes. As the subsequent freeing of the corners of the mouth by resorption of the labial lobes is assumed beneficial for the terrestrial capture of prey by the tongue, this flexibility of the mouth fine-tunes the process of capturing prey throughout the seasonal switching between water and land.

  12. Closed suction drain with bulb

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000039.htm Closed suction drain with bulb To use the sharing features on this page, please enable JavaScript. A closed suction drain is used to remove fluids that build up ...

  13. On Marketing Innovation of Aquatic Feed%水产饲料营销创新的理念与方法

    Institute of Scientific and Technical Information of China (English)

    朱善国

    2012-01-01

    经过多年的高速发展,水产饲料买方市场基本形成。本文分析了水产饲料销售的现状及存在问题,指出水产饲料企业要摆脱困境,必须实施营销创新,采用顾客满意的理念,准确定位,重视品牌建设与维护,并提出具有实践意义的营销创新方向。特别在营销理念创新、产品创新、定位创新、渠道创新、促销创新、组织创新和服务营销等方面提出具体的措施与方法。建议水产饲料企业要善于分析市场,秉承顾客满意的理念,运用STP理论,努力寻找差异化,找到属于自己品牌的蓝海。%The buyer market of aquatic feed has been formed after the high speed development of several years. This paper analyzes the present situation of aquatic feed sales and the existing problems, and points out that if the aquatic feed enterprises want to get out of business difficulty, they must carry out marketing innovation. The aquatic feed enterprises can use the concept of customer satisfaction and accurate positioning, and pay attention to the brand construction and maintenance. This paper also puts forward measures and methods of marketing innovation. Practical measures and methods of marketing innovation are also discussed in many specific fields such as marketing philosophy innovation, product innovation, positioning innovation, promotion innovation, organization innovation and services marketing innovation. Finally this paper gives advices to enterprises in industry of aquatic feed that they should be good at analyzing market, should apply philosophy of customer satisfaction, theory of STP, and try to find differentiation and find out market opportunity of brand competition.

  14. Dynamic stiffness of suction caissons

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Liingaard, Morten; Andersen, Lars

    The purpose of this report is to evaluate the dynamic soil-structure interaction of suction caissons for offshore wind turbines. The investigation is limited to a determination of the vertical dynamic stiffness of suction caissons. The soil surrounding the foundation is homogenous with linear...... of the skirt length, Poisson's ratio and the ratio between soil stiffness and skirt stiffness. Finally the dynamic behaviour at high frequencies is investigated....... viscoelastic properties. The dynamic stiffness of the suction caisson is expressed by dimensionless frequency-dependent dynamic stiffness coefficients corresponding to the vertical degree of freedom. The dynamic stiffness coefficients for the foundations are evaluated by means of a dynamic three...

  15. Replacement of cowdung by fermentation of aquatic and terrestrial plants for use as fuel, fertilizer and biogas plant feed

    Energy Technology Data Exchange (ETDEWEB)

    Das, C.R.; Ghatnekar, S.D.

    1979-01-01

    With 85% of the entire Indian population living in villages and 98% of the household energy requirement of the rural population demanded for cooking, research was undertaken on the supply of biomass for those Indians who do not have cattle. This research was carried out on the fermentation of aquatic and terrestrial plants for use in biogas generation. The plants utilized for biogas generation are: water hyacinth, water lettuce, African payal, duck weed, water spinach, cattail ramban, ipil-ipil, morning glory, paragrass, purple nutsedge, and durva grass.

  16. Landscape composition as a determinant of diversity and functional feeding groups of aquatic macroinvertebrates in southern rivers of the Araucanía, Chile

    Directory of Open Access Journals (Sweden)

    Pablo Fierro

    2015-03-01

    Full Text Available Changes in land use which directly or indirectly affect freshwater fauna constitute one of the principal anthropic factors which have caused world biological diversity to disappear rapidly during recent decades. This fauna includes aquatic benthic macroinvertebrates, organisms presenting temporal and spatial variation due to a variety of factors, one of which is the diverse food resources available in the rivers. To assess the effect of anthropic activities on this fauna, the distribution, abundance and characterisation of the functional feeding groups of aquatic macroinvertebrates were analysed, together with the physical and chemical variables in the environments of four coastal river basins of southern south-central Chile. A total of 104 taxa of macroinvertebrates were recorded, the principal component of the community being the Diptera (26 taxa. The abundance and richness of taxa were greater in summer and lower in winter. The most abundant species belong to the order Ephemeroptera and Plecoptera. Macroinvertebrates were affected by different land use: stations with less anthropic activity and greater altitude had higher macroinvertebrates abundance, while the lowest abundance was found at the lowest stations. The functional feeding groups which were most abundant spatially and temporally were the collector-gatherers and the shredders. The physical and chemical water quality variables proved to be of exceptional quality in all the stations. These results suggest that policies governing changes in land use in central and southern Chile should take into account the dramatic alterations that these changes impose on the macroinvertebrates community. Policies for biodiversity conservation should therefore focus on these small but important organisms in the north Patagonian region of South America, which is a hotspot of world diversity.

  17. Bathtub suction-induced purpura.

    Science.gov (United States)

    Landers, Maeran C; Schroeder, Theresa L

    2004-01-01

    We report two cases of bathtub suction-induced purpura. Two girls, ages 9 and 14 years, developed recurring purpura "spontaneously" in the same lower back location and in the same U-shaped distribution. The patients had similar histopathologic findings, with extravasated erythrocytes and a sparse superficial inflammatory infiltrate. After extensive evaluation, one patient eventually admitted to self-inducing her lesions by creating suction against a bathtub. The second patient denied self-inflicting her lesions; however, her purpura improved when she stopped taking baths.

  18. Dynamic stiffness of suction caissons

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Liingaard, Morten; Andersen, Lars

    This report concerns the dynamic soil-structure interaction of steel suction caissons applied as foundations for offshore wind turbines. An emphasis is put on torsional vibrations and coupled sliding/rocking motion, and the influence of the foundation geometry and the properties of the surrounding...

  19. 用引射技术提高离心泵的汽蚀性能%Improving suction performance of Centrifugal Pumps by Using Jetting Device

    Institute of Scientific and Technical Information of China (English)

    崔宝玲; 朱祖超; 张剑慈; 吴昱; 陈鹰

    2004-01-01

    Improving the suction performance of centrifugal pumps by using jetting device is presented. The theoretical analysis, experimental study and engineering implementation show that suction performance of centrifugal pump can be improved with jetting device and be used for delivering the liquid media requiring high suction performance, whereas the efficiency and head of the pump will decrease a little. The effect of feed-back jetting on suction performance is the most obvious at design point. The suitable rate of feed-back flow is 2%-5%.

  20. Analysis of Tank 38H (HTF-38-15-119, 127) Surface, Subsurface and Tank 43H (HTF-43-15-116, 117 and 118) Surface, Feed Pump Suction and Jet Suction Subsurface Supernatant Samples in Support of Enrichment, Corrosion Control and Salt Batch Planning Programs

    Energy Technology Data Exchange (ETDEWEB)

    Oji, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-12-17

    Compositional feed limits have been established to ensure that a nuclear criticality event for the 2H and 3H Evaporators is not possible. The Enrichment Control Program (ECP) requires feed sampling to determine the equivalent enriched uranium content prior to transfer of waste other than recycle transfers (requires sampling to determine the equivalent enriched uranium at two locations in Tanks 38H and 43H every 26 weeks) The Corrosion Control Program (CCP) establishes concentration and temperature limits for key constituents and periodic sampling and analysis to confirm that waste supernate is within these limits. This report provides the results of analyses on Tanks 38H and 43H surface and subsurface supernatant liquid samples in support of the ECP, the CCP, and the Salt Batch 10 Planning Program.

  1. ZOONOSIS OF AQUATICAL ORGANISMS

    OpenAIRE

    2001-01-01

    Aquatic organisms play a very important role in human nutrition. They also pose a real threat for human health by causing various diseases. Parasites, bacteria and viruses may either directly or indirectly be carried from aquatic organisms to humans. Disease outbreaks are influenced by many factors among which decreased immune response and feeding habits and higyene are most important. More frequent occuence of foodborne diseases has a number of reasons, including international travel and tra...

  2. Impedance of flexible suction caissons

    DEFF Research Database (Denmark)

    Liingaard, Morten; Andersen, Lars; Ibsen, Lars Bo

    2007-01-01

    and coupled sliding-rocking vibrations, influence of the foundation geometry and examination on the properties of the surrounding soil. The soil is simplified as a homogenous linear viscoelastic material and the dynamic stiffness of the suction caisson is expressed in terms of dimensionless frequency......-dependent coefficients corresponding to different degrees of freedom. The dynamic stiffness coefficients for the skirted foundation are evaluated using a three-dimensional coupled boundary element/finite element model. Comparisons with known analytical and numerical solutions indicate that the static and dynamic...

  3. Suction caissons subjected to monotonic combined loading

    DEFF Research Database (Denmark)

    Penzes, P.; Jensen, M.R.; Zania, Varvara

    2016-01-01

    Suction caissons are being increasingly used as offshore foundation solutions in shallow and intermediate water depths. The convenient installation method through the application of suction has rendered this type of foundation as an attractive alternative to the more traditional monopile foundation...... for offshore wind turbines. The combined loading imposed typically to a suction caisson has led to the estimation of their bearing capacity by means of 3D failure envelopes. This study aims to analyse the behaviour of suction caissons for offshore wind turbines subjected to combined loading. Finite element...

  4. Advanced Capabilities Medical Suction Device Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A compact microgravity and hypogravity compatible vacuum device is proposed to provide medical suction and containment of extracted fluids. The proposed aspirator...

  5. Endotracheal suctioning versus minimally invasive airway suctioning in intubated patients : a prospective randomised controlled trial

    NARCIS (Netherlands)

    Van de Leur, JP; Zwaveling, JH; Loef, BG; Van der Schans, CP

    2003-01-01

    Study objective: Endotracheal suctioning in intubated patients is routinely applied in most ICUs but may have negative side effects. We hypothesised that on-demand minimally invasive suctioning would have fewer side effects than routine deep endotracheal suctioning, and would be comparable in durati

  6. Dynamic behaviour of suction caissons

    Energy Technology Data Exchange (ETDEWEB)

    Liingaard, M.

    2006-12-15

    Offshore wind energy is a promising source of energy in the near future, and is rapidly becoming competitive with other power generating technologies. The continuous improvement in wind turbine technology means that the wind turbines have increased tremendously in both size and performance during the last 25 years. In order to reduce the costs, the overall weight of the wind turbine components is minimized, which means that the wind turbine structures become more flexible and thus more sensitive to dynamic excitation. Since the first resonance frequency of the modern offshore wind turbines is close to the excitation frequencies of the rotor system, it is of outmost importance to be able to evaluate the resonance frequencies of the wind turbine structure accurately as the wind turbines increase in size. In order to achieve reliable responses of the wind turbine structure during working loads it is necessary to account for the possibilities of dynamic effects of the soil-structure interaction. The aim of this thesis is to evaluate the dynamic soil-structure interaction of foundations for offshore wind turbines, with the intention that the dynamic properties of the foundation can be properly included in a composite structure-foundation system. The work has been focused on one particular foundation type; the suction caisson. The frequency dependent stiffness (impedance) of the suction caisson has been investigated by means of a three-dimensional coupled Boundary Element/Finite Element model, where the soil is simplified as a homogenous linear viscoelastic material. The dynamic stiffness of the suction caisson is expressed in terms of dimensionless frequencydependent coefficients corresponding to the different degrees of freedom. Comparisons with known analytical and numerical solutions indicate that the static and dynamic behaviour of the foundation are predicted accurately with the applied model. The analysis has been carried out for different combinations of the

  7. Relação clínica entre hábitos de sucção, má oclusão, aleitamento e grau de informação prévia das mães Clinical relationship among suction oral habits, malocclusion, infant feeding and mother's previous knowledge

    Directory of Open Access Journals (Sweden)

    Daniela Feu Rosa Kroeff de Souza

    2006-12-01

    Full Text Available OBJETIVO: este estudo avaliou a relação clínica entre a forma de aleitamento da criança, orientação prévia das mães sobre amamentação natural, instalação de hábitos de sucção não-nutritivos e a presença de más oclusões. METODOLOGIA: foram examinadas 79 crianças (39 com hábitos de sucção e 40 sem hábitos de sucção, de ambos os gêneros, entre 2 e 5 anos, com a dentadura decídua completa e sem perda de tecido dentário interproximal, selecionadas de maneira randomizada, que participavam do Projeto de Bebês da Universidade Federal do Espírito Santo. Apenas um examinador (Kappa intra-examinador: 0,96 avaliou as características faciais e oclusais das crianças, no sentido ântero-posterior, transversal e vertical. As mães foram instruídas a responderem um questionário sobre o desenvolvimento da criança e o grau de orientação prévia que receberam sobre amamentação natural, hábitos, más oclusões e respiração bucal. Foram empregados os testes estatísticos qui-quadrado, teste exato de Fischer, t de Student e Odds Ratio. RESULTADOS: os resultados mostraram que: 1 existe uma relação estatisticamente significante entre o prolongamento do aleitamento materno e a redução da instalação de hábitos de sucção (pAIM: the proposal of this study was to associate infant feeding methods, mother’s previous knowledge about breast-feeding, installation of oral habits and presence of malocclusions. METHODS: 79 children (39 with suction habits and 40 without habits, both genres, from ages between 2 and 5 years old, with complete health deciduous dentition were randomizedly selected from the ones attended at Baby’s Clinic, in Federal University of Espírito Santo. Only one examiner (Kappa intra-examiner= 0.96 evaluated facial characteristics and the occlusion at transversal, antero-posterior and vertical relation. Each mother was oriented to answer a questionnaire concerning child’s development and the degree of

  8. Destabilizing Taylor-Couette flow with suction

    CERN Document Server

    Gallet, Basile; Spiegel, Edward A

    2009-01-01

    We consider the effect of radial fluid injection and suction on Taylor-Couette flow. Injection at the outer cylinder and suction at the inner cylinder generally results in a linearly unstable steady spiralling flow, even for cylindrical shears that are linearly stable in the absence of a radial flux. We study nonlinear aspects of the unstable motions with the energy stability method. Our results, though specialized, may have implications for drag reduction by suction, accretion in astrophysical disks, and perhaps even in the flow in the earth's polar vortex.

  9. Rayleigh's Problem in Magnetohydrodynamics with Suction

    Directory of Open Access Journals (Sweden)

    Girish Chandra Pandey

    1970-01-01

    Full Text Available The extension of Reyleigh's problem to magnetohynamics with suction is considered when the P'ate is non-magnetic and non-conducting. The suction velocity is assumed to be varying as (time-1/2. Series solutions for velocity and skin-friction are obtained under the assumption that the hydromagnetic parameter K is small. It is seen that the skin-friction increases with the magnetic field.

  10. Study on all-involvement innovations of aquatic feed enterprises%我国水产饲料企业的全员创新管理研究

    Institute of Scientific and Technical Information of China (English)

    李春祥

    2016-01-01

    Facing slowdown, overcapacity, intensified competition and decreased profit, aquatic feed enterprises of China need to make all-involvement innovations nowadays. Explaining the connotation of all-involvement innovation from total innovation management perspective,and analyzing the current situation, the problems and their causes, the paper comes up with the improvement solutions to all-involvement innovations of aquatic feed enterprises of China.%当前,我国水产饲料企业面临增速放缓、产能过剩、竞争加剧、利润减少的现状,需要进行全员创新。本文阐述了全面创新管理视角下全员创新的内涵,分析了我国水产饲料企业全员创新的现状与问题,以及问题产生的原因,提出全员创新的改进方案。

  11. Feeding of the megamouth shark (Pisces: Lamniformes: Megachasmidae) predicted by its hyoid arch: a biomechanical approach.

    Science.gov (United States)

    Tomita, Taketeru; Sato, Keiichi; Suda, Kenta; Kawauchi, Junro; Nakaya, Kazuhiro

    2011-05-01

    Studies of the megamouth shark, one of three planktivorous sharks, can provide information about their evolutionary history. Megamouth shark feeding has never been observed in life animals, but two alternative hypotheses on biomechanics suggest either feeding, i.e., ram feeding or suction feeding. In this study, the second moment of area of the ceratohyal cartilages, which is an indicator of the flexural stiffness of the cartilages, is calculated for 21 species of ram- and suction-feeding sharks using computed tomography. The results indicate that suction-feeding sharks have ceratohyal cartilages with a larger second moment of area than ram-feeding sharks. The result also indicates that the ram-suction index, which is an indicator of relative contribution of ram and suction behavior, is also correlated with the second moment of area of the ceratohyal. Considering that large bending stresses are expected to be applied to the ceratohyal cartilage during suction, the larger second moment of area of the ceratohyal of suction-feeding sharks can be interpreted as an adaptation for suction feeding. Based on the small second moment of area of the ceratohyal cartilage of the megamouth shark, the feeding mode of the megamouth shark is considered to be ram feeding, similar to the planktivorous basking shark. From these results, an evolutionary scenario of feeding mechanics of three species of planktivorous sharks can be suggested. In this scenario, the planktivorous whale shark evolved ram feeding from a benthic suction-feeding ancestor. Ram feeding in the planktivorous megamouth shark and the basking shark evolved from ram feeding swimming-type ancestors and that both developed their unique filtering system to capture small-sized prey.

  12. Aquatic plants

    DEFF Research Database (Denmark)

    Madsen, T. V.; Sand-Jensen, K.

    2006-01-01

    Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between...... terrestrial and aquatic environments continues today and is very intensive along stream banks. In this chapter we describe the physical and chemical barriers to the exchange of plants between land and water....

  13. Falling liquid films with blowing and suction

    CERN Document Server

    Thompson, Alice B; Papageorgiou, Demetrios T

    2015-01-01

    Flow of a thin viscous film down a flat inclined plane becomes unstable to long wave interfacial fluctuations when the Reynolds number based on the mean film thickness becomes larger than a critical value (this value decreases as the angle of inclination with the horizontal increases, and in particular becomes zero when the plate is vertical). Control of these interfacial instabilities is relevant to a wide range of industrial applications including coating processes and heat or mass transfer systems. This study considers the effect of blowing and suction through the substrate in order to construct from first principles physically realistic models that can be used for detailed passive and active control studies of direct relevance to possible experiments. Two different long-wave, thin-film equations are derived to describe this system; these include the imposed blowing/suction as well as inertia, surface tension, gravity and viscosity. The case of spatially periodic blowing and suction is considered in detail...

  14. Naevus depiomentosus treated with suction blister grafting

    Directory of Open Access Journals (Sweden)

    Ravikumar B

    2000-01-01

    Full Text Available Naevus depigmentosus is a congenital hypomelanotic condition in which the off white lesions are permanent and cosmetically embarassing. There has been no effective treatment reported so for for this condition. Here we are reporting a patient of naevus depigmentosus on whom we performed suction blister grafting and the resultant pigmentation was satisfactory

  15. Numerical Analysis of Soil Plug Inside Suction Foundations During Suction Penetration by Discrete Element Method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The phenomenon of the soil plug usually rising inside the suction foundations during suction penetration was quantitatively described and predicted. The formation process of the soil plug was simulated and calculated by DEM (discrete element method) model. The seepage flow, the self-weight of soil, the friction on the chamber wall as well as the suction inside the chamber are considered as the main external forces in the process. The results are compared with a set of laboratory model tests performed by using three soil types (sand, silty clay and clay) in the Bohai Sea area. The heights of soil plug from numerical estimations are lower than those from model test results, mainly because the suction pressure and friction resistance are applied in an ideal way under the numerical simulation.

  16. ZOONOSIS OF AQUATICAL ORGANISMS

    Directory of Open Access Journals (Sweden)

    Božidar Kurtović

    2001-12-01

    Full Text Available Aquatic organisms play a very important role in human nutrition. They also pose a real threat for human health by causing various diseases. Parasites, bacteria and viruses may either directly or indirectly be carried from aquatic organisms to humans. Disease outbreaks are influenced by many factors among which decreased immune response and feeding habits and higyene are most important. More frequent occuence of foodborne diseases has a number of reasons, including international travel and trade, microbial adaptation and changes in the food production system. Parasitic diseases occur most frequently as a result of human role in parasites life cycles. The prevalence is further increased by consuming raw fish and shellfish. The main feature of bacterial infections is facultative pathogenicity of most ethiological agents. In most cases disease occures as a result of decreased immunoreactivity. Several bacteria are, however, hightly pathogenic and capable of causing high morbidity and mortality in human. To date it has not been reported the case of human infection with viruses specific for aquatic organisms. Human infections are caused with human viruses and aquatic organisms play role only as vechicles. The greatest risk in that respect present shellfish. Fish and particularly shellfish are likely to cause food poisoning in humans. In most cases the cause are toxins of phithoplancton origins accumulating in shellfish and fish.

  17. Critical Suction Characteristic Analyses of a Wall Climbing Robot

    Institute of Scientific and Technical Information of China (English)

    XU Dai-jun; GAO Xue-shan; WU Xiao-bing; FAN Ning-jun; LI Ke-jie; ZHU Wei

    2007-01-01

    A new method called critical suction is used based on the wall climbing robot demands of miniature structure, moving smartly and low noise.It makes the robot achieve the homeostasis state in the suction cup, and in this condition the robot can stay on the wall reliably and move smartly.The fluid mechanics model and fluid network model are set up to analyze the robot suction system when the airflow is steady or changes suddenly.Furthermore, simulation results indicate the close relation between the key parameters of robot structure and the suction system.Finally the method of critical suction proves correct in theory.

  18. The influence of aquatic macrophytes on distribution and feeding habit of two Asplanchna species (A. priodonta and A. herrickii in shallow wetlands, South Korea

    Directory of Open Access Journals (Sweden)

    Jong-Yun Choi

    2014-06-01

    Full Text Available We tested the hypothesis that the spatial distribution and diet composition of Asplanchna species might be affected by the presence of aquatic macrophytes in 33 wetlands in South Korea. We estimated the densities of Asplanchna and other rotifer and crustacean, together with environmental parameters, in both vegetated and open water zones, from May to June 2011. In the present study, two species of Asplanchna, A. priodonta and A. herrickii, were observed and significantly more abundant in open water zones lacking macrophytes. In particular, the density of A. priodonta was higher than that of A. herrickii, and the density of A. priodonta was strongly positively correlated with the area of open water. In addition, gut content analysis was used to determine their dietary preferences, with the finding that there was apparent differentiation in food source utilisation between the two Asplanchna species; A. priodonta consumed some protozoa, phytoplankton, and exclusively pelagic rotifer, while A. herrickii consumed primarily Euglena. In particular, Keratella and Polyarthra were most commonly consumed by A. priodonta in open water. Macrophytes represent a suitable habitat for epiphytic rotifer but not for pelagic rotifer; this characteristic drives pelagic rotifer such as Asplanchna towards open water and may be responsible for the significant negative correlation that we observed between macrophyte and Asplanchna densities.

  19. Bernoulli Suction Effect on Soap Bubble Blowing?

    Science.gov (United States)

    Davidson, John; Ryu, Sangjin

    2015-11-01

    As a model system for thin-film bubble with two gas-liquid interfaces, we experimentally investigated the pinch-off of soap bubble blowing. Using the lab-built bubble blower and high-speed videography, we have found that the scaling law exponent of soap bubble pinch-off is 2/3, which is similar to that of soap film bridge. Because air flowed through the decreasing neck of soap film tube, we studied possible Bernoulli suction effect on soap bubble pinch-off by evaluating the Reynolds number of airflow. Image processing was utilized to calculate approximate volume of growing soap film tube and the volume flow rate of the airflow, and the Reynolds number was estimated to be 800-3200. This result suggests that soap bubbling may involve the Bernoulli suction effect.

  20. Dynamic stiffness of suction caissons - vertical vibrations

    Energy Technology Data Exchange (ETDEWEB)

    Ibsen, Lars Bo; Liingaard, M.; Andersen, Lars

    2006-12-15

    The dynamic response of offshore wind turbines are affected by the properties of the foundation and the subsoil. The purpose of this report is to evaluate the dynamic soil-structure interaction of suction caissons for offshore wind turbines. The investigation is limited to a determination of the vertical dynamic stiffness of suction caissons. The soil surrounding the foundation is homogenous with linear viscoelastic properties. The dynamic stiffness of the suction caisson is expressed by dimensionless frequency-dependent dynamic stiffness coefficients corresponding to the vertical degree of freedom. The dynamic stiffness coefficients for the foundations are evaluated by means of a dynamic three-dimensional coupled Boundary Element/Finite Element model. Comparisons are made with known analytical and numerical solutions in order to evaluate the static and dynamic behaviour of the Boundary Element/Finite Element model. The vertical frequency dependent stiffness has been determined for different combinations of the skirt length, Poisson's ratio and the ratio between soil stiffness and skirt stiffness. Finally the dynamic behaviour at high frequencies is investigated. (au)

  1. Analysis and Evaluation of Aquatic Feeds Quality in Shaanxi Province%陕西地区水产饲料质量分析与评估

    Institute of Scientific and Technical Information of China (English)

    钟雷; 吉红; 张建禄

    2012-01-01

    在陕西省饲料企业和水产养殖场随机抽取19种鲤草鱼饲料样品,对其物理性状和营养成分进行检测,并依据水产饲料行业标准进行分析和评价.检测结果发现:(1)饲料物理性状均符合行业标准;(2)水分检测值均符合标签值和标准值,但偏低;(3)蛋白检测值与标签值的符合率为78.9%,与标准值的符合率为94.7%;(4)粗脂肪检测值均符合标签值,与标准值的符合率为73.7%;(5)粗纤维检测值与标签值的符合率为94.7%,与标准值的符合率73.7%;(6)粗灰分检测值与标签值的符合率为94.7%,与标准值的符合率为94.7%.说明陕西地区水产饲料质量情况基本良好,但仍存在重视蛋白水平、忽视水分和脂肪水平等问题,建议陕西省水产饲料企业重视养分均衡供应,进一步提高饲料质量.%19 common carp and grass carp feed were collected in Shaanxi province. The physical properties and nutrition indices of the samples were tested according to the latest testing standards,and analyzed based on the latest industry standards. The physical properties were in line with the industry standards, all the moisture content detection values conformed with the label values and standard values, but the results showed that the moisture values of partial samples were lower than standard values. Coincidence rate of detection values and label values for protein content was 78. 9%, while that for detection values and standard values was 94. 7%. The coincidence rate of crude fat content for detention values was 100% and 73. 7% for standard values. Likewise,the conincidence rate of detented valves and label values for crude fiber was 94. 7%,that of standard values was 73. 7%;both of which for crude ash was 94. 7%. The results indicate that the aquafeeds in Shaanxi province are qualified, but the problems such as focusing on protein level but ignoring moisture and fat level still exist. It is proposed that the aquafeeds

  2. Preliminary Analysis on Matric Suction for Barren Soil

    Science.gov (United States)

    Azhar, A. T. S.; Fazlina, M. I. S.; Aziman, M.; Fairus, Y. M.; Azman, K.; Hazreek, Z. A. M.

    2016-11-01

    Most research conducted on slope failures can broadly be attributed to the convergence of three factors, i.e. rainfall, steepness of slope, and soil geological profile. The mechanism of the failures is mainly due to the loss of matric suction of soils by rainwater. When rainwater infiltrates into the slopes, it will start to saturate the soil, i.e., reduce the matric suction. A good understanding of landslide mechanisms and the characteristics of unsaturated soil and rock in tropical areas is crucial in landslide hazard formulation. Most of the slope failures in unsaturated tropical residual soil in Malaysia are mainly due to infiltration, especially during intense and prolonged rainfall, which reduces the soil matric suction and hence decreases the stability of the slope. Therefore, the aim of this research is to determine the matric suction for barren soil and to model an unsaturated slope with natural rainfall to evaluate the effects of matric suction on rainfall intensity. A field test was carried out using the Watermark Soil Moisture Sensor to determine the matric suction. The sensor was connected to a program called SpecWare 9 Basic which also used Data Logging Rain gauge Watermark 1120 to measure the intensity and duration of rainfall. This study was conducted at the Research Centre for Soft Soil which is a new Research and Development (R & D) initiative by Universiti Tun Hussein Onn Malaysia, Parit Raja. Field observation showed that the highest daily suction was recorded during noon while the lowest suction was obtained at night and early morning. The highest matric suction for loose condition was 31.0 kPa while the highest matric suction for compacted condition was 32.4 kPa. The results implied that the field suction variation was not only governed by the rainfall, but also the cyclic evaporation process. The findings clearly indicated that the changes in soil suction distribution patterns occurred due to different weather conditions.

  3. Suction socket suspension for below-knee amputees.

    Science.gov (United States)

    Roberts, R A

    1986-03-01

    In this study the current use of suction suspension for below-knee prostheses is examined by means of two questionnaire surveys. The experience of 56 below-knee (B-K) amputees wearing suction socket prostheses is evaluated comparing suction prostheses with previously worn limbs. A high degree of satisfaction was found, with amputees on the whole reporting improved skin condition, diminished pain, and increased activity levels compared to previous prosthetic history. The experience and opinions of 466 certified prosthetist members of the American Orthotist Prosthetist Association are examined in the second survey, including degree of contact, success, and evaluation of problems in using suction suspension for the B-K amputee. This survey indicated limited contact and familiarity with B-K suction suspension, with only 22% stating they had made this type of prosthesis. Prosthetists cited characteristics of the B-K residual limb as the chief deterrent to a successful fitting.

  4. Suction effects in deep Boom clay block samples

    CERN Document Server

    Delage, Pierre; Tang, Anh-Minh; Cui, Yu-Jun; Li, Xiang-Ling

    2008-01-01

    Extensive investigations have been and are being carried out on a stiff clay from an underground research laboratory located at Mol (Belgium) called Boom clay, in the context of research into deep nuclear waste disposal. Suction effects in deep Boom clay block samples were investigated through the characterisation of the water retention and of the swelling properties of the clay. The data obtained allowed an estimation of the sample initial suction that was reasonably compatible with the in-situ state of stress at a depth of 223 m. The relationship between suction and stress changes during loading and unloading sequences were also examined by running oedometer tests with suction measurements. A rather wide range of the ratio s/sigma 'v (being s the suction and sigma 'v the effective vertical stress) was obtained (0.61 - 1), different from that proposed by Bishop et al; (1974). Finally, the effect of suction release under an isotropic stress close to the estimated sample suction was investigated. A slight swel...

  5. Does the suction drain diameter matter? Bleeding analysis after total knee replacement comparing different suction drain gauges ☆

    OpenAIRE

    Marcos George de Souza Leao; Gladys Martins Pedroza Neta; Thiago Montenegro da Silva; Yacov Machado Costa Ferreira; Waryla Raissa Vasconcelos Dias

    2016-01-01

    ABSTRACT OBJECTIVES: To evaluate bleeding and the estimated blood loss in patients who underwent total knee replacement (TKR) with different closed suction drains (3.2-mm and 4.8-mm gauge). METHODS: This was a randomized controlled trial with 22 patients who underwent TKR and were divided into two groups: Group I, with 11 patients in whom the 3.2-mm suction drain was used, and Group II, with 11 patients in whom the 4.8-mm suction drain was used. The hematocrit was measured after 24, 48 an...

  6. An evaluation of the osmotic method of controlling suction

    CERN Document Server

    Delage, Pierre

    2008-01-01

    Experimental techniques of testing the mechanical properties of unsaturated soils are complex and difficult to conduct. As a consequence, complete sets of parameters that characterise the behaviour of unsaturated soils remain scarce and necessary. In this context, it has been found useful to gather the information obtained after some years of practice of the osmotic technique of controlling suction. As compared to the more documented axis-translation technique, the osmotic technique has its own advantages and drawbacks that are discussed in this paper, together with some potential future developments. The osmotic method has been developed by soil scientists in the 1960s and adapted to geotechnical testing in the early 1970s. This paper presents the osmotic technique and comments on its advantages (including suction condition close to reality and higher suctions easily attained) and drawbacks (including some concern with the membrane resistance and some membrane effects in the suction/concentration calibration...

  7. Influence of localised double suction on a turbulent boundary layer

    Science.gov (United States)

    Oyewola, O.; Djenidi, L.; Antonia, R. A.

    2007-07-01

    The effects of localised suction applied through a pair of porous wall strips on a turbulent boundary layer have been quantified through the measurements of mean velocity and Reynolds stresses. The results indicate that the use of second strip extends the pseudo-relaminarisation zone but also reduces the overshoot in the longitudinal and normal r.m.s. velocities. While the minimum r.m.s. occurs at x/δo=3.0 (one strip) and x/δo=12 (two strips), the reduction observed for the latter case is larger. Relative to no suction, the turbulence level is modified by suction and the effect is enhanced with double suction. This increased effectiveness reflects the fact that the second strip acts on a boundary layer whose near-wall active motion has been seriously weakened by the first strip.

  8. The Cranial Osteology and Feeding Ecology of the Metriorhynchid Crocodylomorph Genera Dakosaurus and Plesiosuchus from the Late Jurassic of Europe

    Science.gov (United States)

    Young, Mark T.; Brusatte, Stephen L.; de Andrade, Marco Brandalise; Desojo, Julia B.; Beatty, Brian L.; Steel, Lorna; Fernández, Marta S.; Sakamoto, Manabu; Ruiz-Omeñaca, Jose Ignacio; Schoch, Rainer R.

    2012-01-01

    Background Dakosaurus and Plesiosuchus are characteristic genera of aquatic, large-bodied, macrophagous metriorhynchid crocodylomorphs. Recent studies show that these genera were apex predators in marine ecosystems during the latter part of the Late Jurassic, with robust skulls and strong bite forces optimized for feeding on large prey. Methodology/Principal Findings Here we present comprehensive osteological descriptions and systematic revisions of the type species of both genera, and in doing so we resurrect the genus Plesiosuchus for the species Dakosaurus manselii. Both species are diagnosed with numerous autapomorphies. Dakosaurus maximus has premaxillary ‘lateral plates’; strongly ornamented maxillae; macroziphodont dentition; tightly fitting tooth-to-tooth occlusion; and extensive macrowear on the mesial and distal margins. Plesiosuchus manselii is distinct in having: non-amblygnathous rostrum; long mandibular symphysis; microziphodont teeth; tooth-crown apices that lack spalled surfaces or breaks; and no evidence for occlusal wear facets. Our phylogenetic analysis finds Dakosaurus maximus to be the sister taxon of the South American Dakosaurus andiniensis, and Plesiosuchus manselii in a polytomy at the base of Geosaurini (the subclade of macrophagous metriorhynchids that includes Dakosaurus, Geosaurus and Torvoneustes). Conclusions/Significance The sympatry of Dakosaurus and Plesiosuchus is curiously similar to North Atlantic killer whales, which have one larger ‘type’ that lacks tooth-crown breakage being sympatric with a smaller ‘type’ that has extensive crown breakage. Assuming this morphofunctional complex is indicative of diet, then Plesiosuchus would be a specialist feeding on other marine reptiles while Dakosaurus would be a generalist and possible suction-feeder. This hypothesis is supported by Plesiosuchus manselii having a very large optimum gape (gape at which multiple teeth come into contact with a prey-item), while Dakosaurus

  9. The cranial osteology and feeding ecology of the metriorhynchid crocodylomorph genera Dakosaurus and Plesiosuchus from the late Jurassic of Europe.

    Directory of Open Access Journals (Sweden)

    Mark T Young

    Full Text Available BACKGROUND: Dakosaurus and Plesiosuchus are characteristic genera of aquatic, large-bodied, macrophagous metriorhynchid crocodylomorphs. Recent studies show that these genera were apex predators in marine ecosystems during the latter part of the Late Jurassic, with robust skulls and strong bite forces optimized for feeding on large prey. METHODOLOGY/PRINCIPAL FINDINGS: Here we present comprehensive osteological descriptions and systematic revisions of the type species of both genera, and in doing so we resurrect the genus Plesiosuchus for the species Dakosaurus manselii. Both species are diagnosed with numerous autapomorphies. Dakosaurus maximus has premaxillary 'lateral plates'; strongly ornamented maxillae; macroziphodont dentition; tightly fitting tooth-to-tooth occlusion; and extensive macrowear on the mesial and distal margins. Plesiosuchus manselii is distinct in having: non-amblygnathous rostrum; long mandibular symphysis; microziphodont teeth; tooth-crown apices that lack spalled surfaces or breaks; and no evidence for occlusal wear facets. Our phylogenetic analysis finds Dakosaurus maximus to be the sister taxon of the South American Dakosaurus andiniensis, and Plesiosuchus manselii in a polytomy at the base of Geosaurini (the subclade of macrophagous metriorhynchids that includes Dakosaurus, Geosaurus and Torvoneustes. CONCLUSIONS/SIGNIFICANCE: The sympatry of Dakosaurus and Plesiosuchus is curiously similar to North Atlantic killer whales, which have one larger 'type' that lacks tooth-crown breakage being sympatric with a smaller 'type' that has extensive crown breakage. Assuming this morphofunctional complex is indicative of diet, then Plesiosuchus would be a specialist feeding on other marine reptiles while Dakosaurus would be a generalist and possible suction-feeder. This hypothesis is supported by Plesiosuchus manselii having a very large optimum gape (gape at which multiple teeth come into contact with a prey-item, while

  10. Suction blister fluid as potential body fluid for biomarker proteins.

    Science.gov (United States)

    Kool, Jeroen; Reubsaet, Léon; Wesseldijk, Feikje; Maravilha, Raquel T; Pinkse, Martijn W; D'Santos, Clive S; van Hilten, Jacobus J; Zijlstra, Freek J; Heck, Albert J R

    2007-10-01

    Early diagnosis is important for effective disease management. Measurement of biomarkers present at the local level of the skin could be advantageous in facilitating the diagnostic process. The analysis of the proteome of suction blister fluid, representative for the interstitial fluid of the skin, is therefore a desirable first step in the search for potential biomarkers involved in biological pathways of particular diseases. Here, we describe a global analysis of the suction blister fluid proteome as potential body fluid for biomarker proteins. The suction blister fluid proteome was compared with a serum proteome analyzed using identical protocols. By using stringent criteria allowing less than 1% false positive identifications, we were able to detect, using identical experimental conditions and amount of starting material, 401 proteins in suction blister fluid and 240 proteins in serum. As a major result of our analysis we construct a prejudiced list of 34 proteins, relatively highly and uniquely detected in suction blister fluid as compared to serum, with established and putative characteristics as biomarkers. We conclude that suction blister fluid might potentially serve as a good alternative biomarker body fluid for diseases that involve the skin.

  11. Nitrous oxide emission by aquatic macrofauna

    DEFF Research Database (Denmark)

    Stief, Peter; Poulsen, Morten; Nielsen, Lars Peter

    2009-01-01

      A large variety of aquatic animals was found to emit the potent greenhouse gas nitrous oxide when nitrate was present in the environment. The emission was ascribed to denitrification by ingested bacteria in the anoxic animal gut, and the exceptionally high N2O-to-N2 production ratio suggested...... delayed induction of the last step of denitrification. Filter- and deposit-feeding animal species showed the highest rates of nitrous oxide emission and predators the lowest, probably reflecting the different amounts of denitrifying bacteria in the diet. We estimate that nitrous oxide emission by aquatic...... animals is quantitatively important in nitraterich aquatic environments like freshwater, coastal marine, and deep-sea ecosystems. The contribution of this source to overall nitrous oxide emission from aquatic environments might further increase because of the projected increase of nitrate availability...

  12. Octopus-like suction cups: from natural to artificial solutions.

    Science.gov (United States)

    Tramacere, F; Follador, M; Pugno, N M; Mazzolai, B

    2015-05-13

    Octopus suckers are able to attach to all nonporous surfaces and generate a very strong attachment force. The well-known attachment features of this animal result from the softness of the sucker tissues and the surface morphology of the portion of the sucker that is in contact with objects or substrates. Unlike artificial suction cups, octopus suckers are characterized by a series of radial grooves that increase the area subjected to pressure reduction during attachment. In this study, we constructed artificial suction cups with different surface geometries and tested their attachment performances using a pull-off setup. First, smooth suction cups were obtained for casting; then, sucker surfaces were engraved with a laser cutter. As expected, for all the tested cases, the engraving treatment enhanced the attachment performance of the elastomeric suction cups compared with that of the smooth versions. Moreover, the results indicated that the surface geometry with the best attachment performance was the geometry most similar to octopus sucker morphology. The results obtained in this work can be utilized to design artificial suction cups with higher wet attachment performance.

  13. Dielectric elastomer actuators for octopus inspired suction cups.

    Science.gov (United States)

    Follador, M; Tramacere, F; Mazzolai, B

    2014-09-25

    Suction cups are often found in nature as attachment strategy in water. Nevertheless, the application of the artificial counterpart is limited by the dimension of the actuators and their usability in wet conditions. A novel design for the development of a suction cup inspired by octopus suckers is presented. The main focus of this research was on the modelling and characterization of the actuation unit, and a first prototype of the suction cup was realized as a proof of concept. The actuation of the suction cup is based on dielectric elastomer actuators. The presented device works in a wet environment, has an integrated actuation system, and is soft. The dimensions of the artificial suction cups are comparable to proximal octopus suckers, and the attachment mechanism is similar to the biological counterpart. The design approach proposed for the actuator allows the definition of the parameters for its development and for obtaining a desired pressure in water. The fabricated actuator is able to produce up to 6 kPa of pressure in water, reaching the maximum pressure in less than 300 ms.

  14. Aquatic Therapy for Children

    Science.gov (United States)

    Kucher, Greta; Moore, Kelsey; Rodia, Rachel; Moser, Christy Szczech

    2015-01-01

    Aquatic therapy has long been highlighted in the literature as a potentially powerful therapeutic intervention. This review will highlight basic definitions of aquatic therapy, review salient research, and identify specific diagnoses that may benefit from aquatic therapy. Online resources, blogs, and books that occupational therapists may find…

  15. Monitoring field soil suction using a miniature tensiometer

    CERN Document Server

    Cui, Yu-Jun; Mantho, Altin Theodore; De Laure, Emmanuel

    2008-01-01

    An experimental device was developed to monitor the field soil suction using miniature tensiometer. This device consists of a double tube system that ensures a good contact between the tensiometer and the soil surface at the bottom of the testing borehole. This system also ensures the tensiometer periodical retrieving without disturbing the surrounding soil. This device was used to monitor the soil suction at the site of Boissy-le-Ch\\^atel, France. The measurement was performed at two depths (25 and 45 cm) during two months (May and June 2004). The recorded suction data are analyzed by comparing with the volumetric water content data recorded using TDR (Time Domain Reflectometer) probes as well as the meteorological data. A good agreement between these results was observed, showing a satisfactory performance of the developed device.

  16. Nonparallel stability of boundary layers with pressure gradients and suction

    Science.gov (United States)

    Saric, W. S.; Nayfeh, A. H.

    1977-01-01

    An analysis is presented for the linear nonparallel stability of boundary layer flows with pressure gradients and suction. The effect of the boundary layer growth is included by using the method of multiple scales. The present analysis is compared with those of Bouthier and Gaster and the roles of the different definitions of the amplification rates are discussed. The results of these theories are compared with experimental data for the Blasius boundary layer. Calculations are presented for stability characteristics of boundary layers with pressure gradients and nonsimilar suction distributions.

  17. Stability of flow over plates with porous suction strips

    Science.gov (United States)

    Reed, H. L.; Nayfeh, A. H.

    1981-01-01

    This paper addresses the stability of two-dimensional, incompressible boundary-layer flow over plates with suction through porous strips. The mean flow is calculated using linearized triple-deck, closed-form solutions. The stability results of the triple-deck theory are shown to be in good agreement with those of the interacting boundary layers. Then different configurations of number, spacing, and mass flow rate through such porous strips are analyzed and compared with nonsimilar uniform-suction stability results from the point of view of applicability to laminar flow control.

  18. 3000m3/h cutter-suction dredge

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ In October 2004, the Fumin 9 3000 m3/h cutter-suction dredge co-designed by the Dutch IHC and Guangzhou Wenchong Shipyard went through a dock usability test and a 25 meter clean water test. The dredge is the largest of its kind in China, and the most advanced and most efficient cutter-suction dredge in the world. The IHC was responsible for the design of the ship till its working design was taken over by Guangzhou Wenchong Shipyard, the builder of the dredge, who had started its construction on October 23, 2003.

  19. Anatomical adaptations of aquatic mammals.

    Science.gov (United States)

    Reidenberg, Joy S

    2007-06-01

    This special issue of the Anatomical Record explores many of the anatomical adaptations exhibited by aquatic mammals that enable life in the water. Anatomical observations on a range of fossil and living marine and freshwater mammals are presented, including sirenians (manatees and dugongs), cetaceans (both baleen whales and toothed whales, including dolphins and porpoises), pinnipeds (seals, sea lions, and walruses), the sea otter, and the pygmy hippopotamus. A range of anatomical systems are covered in this issue, including the external form (integument, tail shape), nervous system (eye, ear, brain), musculoskeletal systems (cranium, mandible, hyoid, vertebral column, flipper/forelimb), digestive tract (teeth/tusks/baleen, tongue, stomach), and respiratory tract (larynx). Emphasis is placed on exploring anatomical function in the context of aquatic life. The following topics are addressed: evolution, sound production, sound reception, feeding, locomotion, buoyancy control, thermoregulation, cognition, and behavior. A variety of approaches and techniques are used to examine and characterize these adaptations, ranging from dissection, to histology, to electron microscopy, to two-dimensional (2D) and 3D computerized tomography, to experimental field tests of function. The articles in this issue are a blend of literature review and new, hypothesis-driven anatomical research, which highlight the special nature of anatomical form and function in aquatic mammals that enables their exquisite adaptation for life in such a challenging environment.

  20. Aquatic versus terrestrial attachment: Water makes a difference

    Directory of Open Access Journals (Sweden)

    Petra Ditsche

    2014-12-01

    Full Text Available Animal attachment to a substrate is very different in terrestrial and aquatic environments. We discuss variations in both the forces acting to detach animals and forces of attachment. While in a terrestrial environment gravity is commonly understood as the most important detachment force, under submerged conditions gravity is nearly balanced out by buoyancy and therefore matters little. In contrast, flow forces such as drag and lift are of higher importance in an aquatic environment. Depending on the flow conditions, flow forces can reach much higher values than gravity and vary in magnitude and direction. For many of the attachment mechanisms (adhesion including glue, friction, suction and mechanical principles such as hook, lock, clamp and spacer significant differences have to be considered under water. For example, the main principles of dry adhesion, van der Waals forces and chemical bonding, which make a gecko stick to the ceiling, are weak under submerged conditions. Capillary forces are very important for wet adhesion, e.g., in terrestrial beetles or flies, but usually do not occur under water. Viscous forces are likely an important contributor to adhesion under water in some mobile animals such as torrent frogs and mayflies, but there are still many open questions to be answered. Glue is the dominant attachment mechanism of sessile aquatic animals and the aquatic realm presents many challenges to this mode of attachment. Viscous forces and the lack of surface tension under submerged conditions also affect frictional interactions in the aquatic environment. Moreover, the limitation of suction to the pressure difference at vacuum conditions can be ameliorated under water, due to the increasing pressure with water depth.

  1. Aquatic Plant Control Research Program: The Habitat Value of Aquatic Macrophytes for Macroinvertebrates

    Science.gov (United States)

    1989-11-01

    feed on abunaant organisms provided that they are palatable. Notable predators occur among the orders Coleoptera (beetles), Odonata (damselflies and...Westfall, M. J., Jr. 1984. " Odonata ," An Introduction to the Aquatic Insects of North America, 2d ed., R. W. Merritt and K. W. Cummins, eds., Kendall

  2. Patient recollection of airway suctioning in the ICU : routine versus a minimally invasive procedure

    NARCIS (Netherlands)

    Van de Leur, JP; Zwaveling, JH; Loef, BG; Van der Schans, CP

    2003-01-01

    Objective: Many patients have an unpleasant recollection of routine endotracheal suctioning after discharge from the Intensive Care Unit (ICU). We hypothesized that through minimally invasive airway suctioning discomfort and stress may be prevented, resulting in less recollection. Design: A prospect

  3. Dual-durometer soft suction foot robot for concrete inspection

    Science.gov (United States)

    Huston, Dryver; Burns, Dylan; Gardner-Morse, John; Montane, Paul; Angola, Enrique

    2014-03-01

    Climbing on concrete, masonry and brick with automated machines is difficult due to the uneven surfaces that prevent getting a good grip. This paper describes developments in using dual-durometer pneumatic suction feet for gripping onto concrete surfaces as part of a multi-legged robotic climbing system for inspecting concrete structures with vertical walls. The dual durometer technique presents a compliant suction tip to the concrete thereby producing a good seal against an irregular surface, and stiff component to deliver the structural rigidity needed for walking and climbing. Individually actuated pneumatic Venturi vacuum generators provide the suction from positive pneumatic pressure in a manner that is robust against leaks that cause the systemic vacuum collapse that can plague other vacuum configurations. The feet are attached to a six-legged robot that with a nominal floor walking capability and gait. Climbing a wall requires modification to leg actuation and gait, along with suction feet. System design, integration, concrete wall climbing performance and sensor deployment in the form of a lightweight ground penetrating radar system are presented.

  4. Determination of Minimum Suction Level Necessary for Field Dental Units

    Science.gov (United States)

    2010-04-01

    as fractured dental restorations and teeth, loose/ lost crowns and bridges, and endodontic and periodontal dis- ease.’"’ For the U.S. Marine Corps and...of blood, saliva , and debris. In some situations where traumatic injuries to the oral cavity have occurred, adequate suction may be required to

  5. Improved suction technique for the characterization of construction materials

    DEFF Research Database (Denmark)

    Thygesen, Lisbeth Garbrecht; Hansen, Kurt Kielsgaard

    2007-01-01

    The suction technique is a method from soil science that is used for the study of moisture storage capacity in porous construction materials at high relative humidity levels (above approximately 93 %). The samples to be studied are placed in a pressurized container (an extractor) on a water satur...

  6. Estudo comparativo da dieta, hábitos alimentares e morfologia trófica de duas espécies simpátricas, de peixes de pequeno porte, associados à macrófitas aquáticas = Comparative study about diet, feeding habits and trophic morphology of two sympatric species of small fishes in association with aquatic macrophytes

    Directory of Open Access Journals (Sweden)

    Norma Segatti Hahn

    2006-10-01

    Full Text Available Nesse estudo foram avaliados aspectos da dieta e morfologia trófica de duas espécies simpátricas, uma de Cheirodontinae e uma de Aphyocharacinae, associadas a macrofitas aquáticas, em nove lagoas isoladas da planície de inundação do alto rio Paraná, Brasil, no ano de 2001. A análise da dieta mostrou que Aphyocharax anisitsi consumiupredominantemente microcrustáceos e Serrapinnus notomelas predominantemente algas. A morfologia do trato alimentar, incluindo boca, dentes, rastros branquiais e estômago, apresentou, aparentemente, o mesmo padrão para as duas espécies. Entretanto, os dentes são mais robustos em S. notomelas. Houve interação significativa entre o comprimento padrão (F2,215 = 74,89; pIn this study we analyzed the diet and trophic morphology of two species, one of Cheirodontinae and one of Aphyocharacinae, associated with aquatic macrophytes in nine isolated lagoons of the Paraná river floodplain, Brazil, during 2001. Diet showed that Aphyocharax anisitsi feed mainly on microcrustaceans and Serrapinnus notomelas feed mainly on algae. Trophic morphology, including mouth, tooth, gill rakers and stomach showed apparently the same pattern for the two species. However, teeth are the biggest and the hardest in S. notomelas. Regarding intestine length there was significant interaction between standard length (F2.215 = 74.89; p<0.0001 and the species (F1.215 = 4.72; p<0.0001. Higher mean of intestine length was verified in S. notomelas and a smaller mean in A. anisitsi. Based on dates of diet and morphology, it is possible to conclude that there are trophic segregation between the two species. Thus, the co-existence of these species is possible in function ofthe wide food supply given by aquatic macrophytes.

  7. Lake Bathymetric Aquatic Vegetation

    Data.gov (United States)

    Minnesota Department of Natural Resources — Aquatic vegetation represented as polygon features, coded with vegetation type (emergent, submergent, etc.) and field survey date. Polygons were digitized from...

  8. Does the suction drain diameter matter? Bleeding analysis after total knee replacement comparing different suction drain gauges

    Directory of Open Access Journals (Sweden)

    Marcos George de Souza Leao

    Full Text Available ABSTRACT OBJECTIVES: To evaluate bleeding and the estimated blood loss in patients who underwent total knee replacement (TKR with different closed suction drains (3.2-mm and 4.8-mm gauge. METHODS: This was a randomized controlled trial with 22 patients who underwent TKR and were divided into two groups: Group I, with 11 patients in whom the 3.2-mm suction drain was used, and Group II, with 11 patients in whom the 4.8-mm suction drain was used. The hematocrit was measured after 24, 48 and 72 h after surgery in order to calculate the estimated blood loss. The drained volume was measured 3, 6, 12, 24, and 48 h after TKR, and thereafter both groups were compared. RESULTS: Regarding the hematocrit, there were no differences between groups in measured periods (24, 48, and 72 h after surgery. The total bleeding measured at the suction drains within 48 h was higher in Group II, with a statistically significant difference (p = 0.005; in the first 24 h, there was major bleeding in Group II (mean 893 mL, with a significant difference (p = 0.004. Between 24 and 48 h, there was no statistically significant difference in both groups (p = 0.710. The total estimated bleeding was higher in Group I, with mean of 463 mL, versus 409 mL in Group II, with no statistical significance (p = 0.394. CONCLUSIONS: Bleeding was higher in the group that used the 4.8 mm gauge suction drain, with no differences in hematocrit and estimated blood loss.

  9. Compressor bleed cooling fluid feed system

    Science.gov (United States)

    Donahoo, Eric E; Ross, Christopher W

    2014-11-25

    A compressor bleed cooling fluid feed system for a turbine engine for directing cooling fluids from a compressor to a turbine airfoil cooling system to supply cooling fluids to one or more airfoils of a rotor assembly is disclosed. The compressor bleed cooling fluid feed system may enable cooling fluids to be exhausted from a compressor exhaust plenum through a downstream compressor bleed collection chamber and into the turbine airfoil cooling system. As such, the suction created in the compressor exhaust plenum mitigates boundary layer growth along the inner surface while providing flow of cooling fluids to the turbine airfoils.

  10. Ontogenetic differences in the feeding biomechanics of oviparous and viviparous caecilians (Lissamphibia: Gymnophiona).

    Science.gov (United States)

    Kleinteich, Thomas

    2010-10-01

    Caecilians have a unique dual jaw-closing system in that jaw closure is driven by the ancestral jaw-closing muscles (mm. levatores mandibulae) plus a secondarily recruited hyobranchial muscle (m. interhyoideus posterior). There is a variety of feeding habits (suction feeding, skin feeding, intrauterine scraping, and biting) during ontogeny that relate to reproductive modes in different caecilian species. This study examines the cranial biomechanics of caecilians in the suction-feeding larva of Ichthyophis cf. kohtaoensis, in the embryo and juvenile of the skin-feeding Boulengerula taitana, and in a newborn of the intrauterine feeder Typhlonectes natans. A lever arm model was applied to calculate effective mechanical advantages of jaw-closing muscles over gape angles and to predict total bite force in developing caecilians. In I. cf. kohtaoensis, Notable differences were found in the larval jaw-closing system compared to that of the adult. The suction-feeding larva of I. cf. kohtaoensis has comparatively large mm. levatores mandibulae that insert with an acute muscle fiber angle to the lower jaw and a m. interhyoideus posterior that has its optimal leverage at small gape angles. Conversely, the skin-feeding juvenile of B. taitana and the neonate T. natans are very similar in the feeding parameters considered herein compared to adult caecilians. Some ontogenetic variation in the feeding system of B. taitana before the onset of feeding was present. This study contributes to our understanding of the functional demands that feeding habits put on the development of cranial structures.

  11. Detection of ventricular suction in an implantable rotary blood pump using support vector machines.

    Science.gov (United States)

    Wang, Yu; Faragallah, George; Divo, Eduardo; Simaan, Marwan A

    2011-01-01

    A new suction detection algorithm for rotary Left Ventricular Assist Devices (LVAD) is presented. The algorithm is based on a Lagrangian Support Vector Machine (LSVM) model. Six suction indices are derived from the LVAD pump flow signal and form the inputs to the LSVM classifier. The LSVM classifier is trained and tested to classify pump flow patterns into three states: No Suction, Approaching Suction, and Suction. The proposed algorithm has been tested using existing in vivo data. When compared to three existing methods, the proposed algorithm produced superior performance in terms of classification accuracy, stability, and learning speed. The ability of the algorithm to detect suction provides a reliable platform in the development of a pump speed controller that has the capability of avoiding suction.

  12. Response of mean turbulent energy dissipation rate and spectra to concentrated wall suction

    Science.gov (United States)

    Oyewola, O.; Djenidi, L.; Antonia, R. A.

    2008-01-01

    The response of mean turbulent energy dissipation rate and spectra to concentrated suction applied through a porous wall strip has been quantified. Both suction and no suction data of the spectra collapsed reasonably well for Kolmogorov normalised wavenumber k {1/*} > 0.2. Similar results were also observed for second-order structure functions (not shown) for Kolmogorov normalised radius r* suction results shows a significant departure from the no suction case of the Kolmogorov normalised spectra and second-order structure functions for k {1/*} 20, respectively. The departure at the larger scales with collapse at the small scales suggests that suction induce a change in the small-scale motion. This is also reflected in the alteration of mean turbulent energy dissipation rate and Taylor microscale Reynolds number. This change is a result of the weakening of the large-scale structures. The effect is increased as the suction rate is increased.

  13. Endotracheal suctioning of the adult intubated patient--what is the evidence?

    DEFF Research Database (Denmark)

    Pedersen, Carsten M; Rosendahl-Nielsen, Mette; Hjermind, Jeanette

    2008-01-01

    Intubated patients may be unable to adequately cough up secretions. Endotracheal suctioning is therefore important in order to reduce the risk of consolidation and atelectasis that may lead to inadequate ventilation. The suction procedure is associated with complications and risks including...... bleeding, infection, atelectasis, hypoxemia, cardiovascular instability, elevated intracranial pressure, and may also cause lesions in the tracheal mucosa. The aim of this article was to review the available literature regarding endotracheal suctioning of adult intubated intensive care patients...... and to provide evidence-based recommendations The major recommendations are suctioning only when necessary, using a suction catheter occluding less than half the lumen of the endotracheal tube, using the lowest possible suction pressure, inserting the catheter no further than carina, suctioning no longer than 15...

  14. Stability of flow over axisymmetric bodies with porous suction strips

    Science.gov (United States)

    Nayfeh, A. H.; Reed, H. L.

    1982-01-01

    Linear triple deck, closed form solutions for mean-flow quantities are developed for axisymmetric incompressible flow past a body with porous strips. The solutions account for upstream influence and are linear superpositions of the flow past the body without suction plus the perturbations due to the suction strips. Flow past the suctionless body is calculated using the Transition Analysis Program System, and a simple linear optimization scheme to determine number, spacing, and mass flow rate through the strips on an axisymmetric body is developed using the linear, triple-deck, closed-form solutions. The theory is demonstrated by predicting optimal strip distributions, and the effect of various adverse pressure-gradient situations on stability is studied.

  15. Prolonged suction drainage prevents serous wound discharge after cardiac surgery.

    Science.gov (United States)

    Kockelbergh, R C; Harris, A M; John, R M; Bailey, J S; Firmin, R K

    1994-01-01

    A series of 180 patients was randomised to two groups after median sternotomy performed for cardiac surgery in order to evaluate the effect of suction drainage on serous wound discharge. In group A all wounds were drained using two conventional mediastinal drains, while in group B one suction drain and one conventional mediastinal drain were employed. Five patients developed serous wound discharge in group B compared with 14 in group A (chi 2, P < 0.02). There were no significant differences between the rates of major wound infection (group A, n = 1; group B, n = 1) or the incidence of postoperative pericardial effusion assessed by echocardiography (group A, n = 10; group B, n = 5).

  16. The use of postoperative suction drainage in total hip arthroplasty.

    Science.gov (United States)

    Acus, R W; Clark, J M; Gradisar, I A; Kovacik, M W

    1992-11-01

    Two hundred eight primary total hip arthroplasties were reviewed to evaluate the effect of closed suction drainage. This review included 45 hips in which closed drains were used and 163 hips in which drains were not used. These two groups were compared for possible differences in wound problems, temperature elevations, changes in Hgb/Hct, and the need for transfusions. There was no statistically significant difference in postoperative temperatures or decrease in Hgb. However, there were four superficial wound infections in the drained group and three superficial wound infections in the non-drained group (P < .025). There were no deep infections in either group. These findings suggest closed suction drainage provides no apparent advantage in uncomplicated primary total hip arthroplasty.

  17. A practical method for suction estimation in unsaturated soil testing

    OpenAIRE

    Amaral, M.F.; Viana da Fonseca, A.; Romero Morales, Enrique Edgar; Arroyo Alvarez de Toledo, Marcos

    2013-01-01

    This research presents an alternative methodology to estimate suction in triaxial tests carried out under constant water content. A preliminary determination of the retention curve is proposed using two complementary techniques, namely psychrometer measurements and mercury intrusion porosimetry results. Starting with the definition of a set of retention curves at different void ratios, an attempt is made for establishing a correspondence of the measured retention curves with the results of a ...

  18. Face and neck suction-assisted lipectomy associated with rhytidectomy.

    Science.gov (United States)

    Teimourian, B

    1983-11-01

    A technique is described in which suction-assisted lipectomy is used for excessive fat removal in association with the standard rhytidectomy. It is safe, reliable, and can be performed through a small horizontal submental incision. A more natural appearing neck is produced by adjusting the amount of fat removed. Areas previously considered dangerous for excision because of possible damage to branches of the facial nerves, such as the cheek areas, jowls, parotid, and nasolabial folds, can now be approached.

  19. Abdominal drainage following cholecystectomy: high, low, or no suction?

    OpenAIRE

    McCormack, T T; Abel, P D; Collins, C. D.

    1983-01-01

    A prospective trial to assess the effect of suction in an abdominal drain following cholecystectomy was carried out. Three types of closed drainage system were compared: a simple tube drain, a low negative pressure drain, and a high negative pressure drain: 120 consecutive patients undergoing cholecystectomy were randomly allocated to one of the three drainage groups. There was no significant difference in postoperative pyrexia, wound infection, chest infection, or hospital stay. This study f...

  20. Reliable site for suction blister induction and harvesting

    Directory of Open Access Journals (Sweden)

    Laxmisha Chandrashekar

    2005-01-01

    Full Text Available Background: Suction blister grafting is a useful modality of treatment of patients with resistant and stable vitiligo. However, there have been no detailed studies to find out the best donor site for blister formation. Methods: The study was conducted between the period of October 2004 and February 2005 in the dermatology department at a tertiary care center. Nine patients with vitiligo (focal vitiligo, 3; mucosal vitiligo, 2; acrofacial vitiligo, 2; vitiligo vulgaris, 1; and segmental vitiligo, 1 were selected for blister harvesting and grafting. The blisters were raised using the method described by Gupta et al. Results: Suction blisters were attempted to be raised at 52 sites, but only 38 blisters could be raised, 24 complete and 14 incomplete. Blisters were raised in all the three cases on the flexor aspect of the arm (100%, 15 of 17 cases (88.2% on the flexor aspect of the forearm, 4 of 5 cases (80% on the abdomen, 11 of 16 cases (68.7% on the anterolateral thigh, and less frequently over leg or foot. Complete blisters were formed in 13/15 cases (86.6% on the flexor aspect of the forearm, 6/11 cases (54.5% on the anterolateral thigh, and in all cases over leg. Conclusion: The flexor aspect of the forearm is a good site for suction blister harvesting.

  1. Turbulence transition in the asymptotic suction boundary layer

    CERN Document Server

    Kreilos, Tobias; Schneider, Tobias M; Veble, Gregor; Duguet, Yohann; Schlatter, Philipp; Henningson, Dan S; Eckhardt, Bruno

    2015-01-01

    We study the transition to turbulence in the asymptotic suction boundary layer (ASBL) by direct numerical simulation. Tracking the motion of trajectories intermediate between laminar and turbulent states we can identify the invariant object inside the laminar-turbulent boundary, the edge state. In small domains, the flow behaves like a travelling wave over short time intervals. On longer times one notes that the energy shows strong bursts at regular time intervals. During the bursts the streak structure is lost, but it reforms, translated in the spanwise direction by half the domain size. Varying the suction velocity allows to embed the flow into a family of flows that interpolate between plane Couette flow and the ASBL. Near the plane Couette limit, the edge state is a travelling wave. Increasing the suction, the travelling wave and a symmetry-related copy of it undergo a saddle-node infinite-period (SNIPER) bifurcation that leads to bursting and discrete-symmetry shifts. In wider domains, the structures loc...

  2. Manipulation of Leading-Edge Vortex Evolution by Applied Suction

    Science.gov (United States)

    Buchholz, James; Akkala, James

    2016-11-01

    The generation and shedding of vortices from unsteady maneuvering bodies can be characterized within a framework of vorticity transport, accounting for the effects of multiple sources and sinks of vorticity on the overall circulation of the vortex system. On a maneuvering wing, the diffusive flux of secondary vorticity from the surface is a critical contributor to the strength and dynamics of the leading-edge vortex, suggesting that flow control strategies targeting the manipulation of the secondary vorticity flux and the secondary vortex may provide an effective means of manipulating vortex development. Suction has been applied in the vicinity of the secondary vortex during the downstroke of a periodically-plunging flat-plate airfoil, and the flow evolution and aerodynamic loads are compared to the baseline case in which suction is not applied. Observation of the resulting surface pressure distribution and flow evolution suggest that the secondary flux of vorticity and the evolution of the flow field can be altered subject to appropriate position of the suction ports relative to the developing vortex structures, and at a specific temporal window in the development of the vortex. This work was supported by the Air Force Office of Scientific Research, Grant Number FA9550-16-1-0107 and NSF EPSCoR Grant Number EPS1101284.

  3. Effect of wall suction on the stability of compressible subsonic flows over smooth two-dimensional backward-facing steps

    Science.gov (United States)

    Al-Maaitah, Ayman A.; Nayfeh, Ali H.; Ragab, Saad A.

    1989-01-01

    The effect of suction on the stability of compressible flows over backward-facing steps is investigated. Mach numbers up to 0.8 are considered. The results show that continuous suction stabilizes the flow outside the separation bubble, but it destabilizes the flow inside it. Nevertheless, the overall N factor decreases as the suction level increases due to the considerable reduction of the separation bubble. For the same suction flow rate, properly distributed suction strips stabilize the flow more than continuous suction. The size of the separation bubble, and hence its effect on the instability can be considerably reduced by placing strips with high suction velocities in the separation region.

  4. Feeding mechanics and bite force modelling of the skull of Dunkleosteus terrelli, an ancient apex predator.

    Science.gov (United States)

    Anderson, Philip S L; Westneat, Mark W

    2007-02-22

    Placoderms are a diverse group of armoured fishes that dominated the aquatic ecosystems of the Devonian Period, 415-360 million years ago. The bladed jaws of predators such as Dunkleosteus suggest that these animals were the first vertebrates to use rapid mouth opening and a powerful bite to capture and fragment evasive prey items prior to ingestion. Here, we develop a biomechanical model of force and motion during feeding in Dunkleosteus terrelli that reveals a highly kinetic skull driven by a unique four-bar linkage mechanism. The linkage system has a high-speed transmission for jaw opening, producing a rapid expansion phase similar to modern fishes that use suction during prey capture. Jaw closing muscles power an extraordinarily strong bite, with an estimated maximal bite force of over 4400 N at the jaw tip and more than 5300 N at the rear dental plates, for a large individual (6 m in total length). This bite force capability is the greatest of all living or fossil fishes and is among the most powerful bites in animals.

  5. Comparison the Effects of Shallow and Deep Endotracheal Tube Suctioning on Respiratory Rate, Arterial Blood Oxygen Saturation and Number of Suctioning in Patients Hospitalized in the Intensive Care Unit: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Mohammad Abbasinia

    2014-09-01

    Full Text Available Introduction: Endotracheal tube suctioning is essential for improve oxygenation in the patients undergoing mechanical ventilation. There are two types of shallow and deep endotracheal tube suctioning. This study aimed to evaluate the effect of shallow and deep suctioning methods on respiratory rate (RR, arterial blood oxygen saturation (SpO2 and number of suctioning in patients hospitalized in the intensive care units of Al-Zahra Hospital, Isfahan, Iran. Methods: In this randomized controlled trial, 74 patients who hospitalized in the intensive care units of Isfahan Al-Zahra Hospital were randomly allocated to the shallow and deep suctioning groups. RR and SpO2 were measured immediately before, immediately after, 1 and 3 minute after each suctioning. Number of suctioning was also noted in each groups. Data were analyzed using repeated measures analysis of variance (RMANOVA, chi-square and independent t-tests. Results: RR was significantly increased and SpO2 was significantly decreased after each suctioning in the both groups. However, these changes were not significant between the two groups. The numbers of suctioning was significantly higher in the shallow suctioning group than in the deep suctioning group. Conclusion: Shallow and deep suctioning had a similar effect on RR and SpO2. However, shallow suctioning caused further manipulation of patient’s trachea than deep suctioning method. Therefore, it seems that deep endotracheal tube suctioning method can be used to clean the airway with lesser manipulation of the trachea.

  6. Suction characteristics of compacted zeolite-bentonite and sand-bentonite mixtures.

    Science.gov (United States)

    Durukan, Seda; Pulat, Hasan Firat; Yukselen-Aksoy, Yeliz

    2014-02-01

    Soil suction is one of the most important parameters describing soil moisture conditions for unsaturated soils used in landfill liners. However, few studies have been conducted on the suction characteristics of compacted zeolite-bentonite mixtures (ZBMs) and sand-bentonite mixtures (SBMs), which are proposed for use as liner materials. Nevertheless, zeolite is known for its microporous skeleton containing cages and tunnels and it has a great physical affiliation to water uptake. Zeolite and bentonite, in a mixture, are thought to be in competition for water uptake and this may alter the distribution of water content for each soil in the mixture. The present study investigated the suction properties of compacted ZBMs and SBMs for varying mixing ratios and compaction water contents. The soil suction measurement technique chosen was the filter-paper method. The suction characteristics of powdered, granular, and block zeolites, as well as 0, 10, and 20% bentonite in ZBMs and SBMs were measured and compared with each other. Contaminated compacted ZBMs are compared with those of uncontaminated compacted ones at the optimum water content for the 10% and 20% mixtures. The results show that suction capacity of zeolite increases with grain size. As bentonite content increases, both matric and total suction increase for both mixtures. ZBMs have higher matric suction values than SBMs, but not total suction values. Contaminated total suction values are found to be higher than those of uncontaminated samples due to an increase in dissolved ion concentration.

  7. Numerical simulation of installation process and uplift resistance for an integrated suction foundation in deep ocean

    Science.gov (United States)

    Li, Ying; Yang, Shu-geng; Yu, Shu-ming

    2016-03-01

    A concept design, named integrated suction foundation, is proposed for a tension leg platform (TLP) in deep ocean. The most important improvement in comparing with the traditional one is that a pressure-resistant storage module is designed. It utilizes the high hydrostatic pressure in deep ocean to drive water into the module to generate negative pressure for bucket suction. This work aims to further approve the feasibility of the concept design in the aspect of penetration installation and the uplift force in-place. Seepage is generated during suction penetration, and can have both positive and negative effects on penetration process. To study the effect of seepage on the penetration process of the integrated suction foundation, finite element analysis (FEA) is carried out in this work. In particular, an improved methodology to calculate the penetration resistance is proposed for the integrated suction foundation with respect to the reduction factor of penetration resistance. The maximum allowable negative pressure during suction penetration is calculated with the critical hydraulic gradient method through FEA. The simulation results of the penetration process show that the integrated suction foundation can be installed safely. Moreover, the uplift resistance of the integrated suction foundation is calculated and the feasibility of the integrated suction foundation working on-site is verified. In all, the analysis in this work further approves the feasibility of the integrated suction foundation for TLPs in deep ocean applications.

  8. Numerical Simulation of Installation Process and Uplift Resistance for An Integrated Suction Foundation in Deep Ocean

    Institute of Scientific and Technical Information of China (English)

    李英; 杨树耕; 于书铭

    2016-01-01

    A concept design, named integrated suction foundation, is proposed for a tension leg platform (TLP) in deep ocean. The most important improvement in comparing with the traditional one is that a pressure-resistant storage module is designed. It utilizes the high hydrostatic pressure in deep ocean to drive water into the module to generate negative pressure for bucket suction. This work aims to further approve the feasibility of the concept design in the aspect of penetration installation and the uplift force in-place. Seepage is generated during suction penetration, and can have both positive and negative effects on penetration process. To study the effect of seepage on the penetration process of the integrated suction foundation, finite element analysis (FEA) is carried out in this work. In particular, an improved methodology to calculate the penetration resistance is proposed for the integrated suction foundation with respect to the reduction factor of penetration resistance. The maximum allowable negative pressure during suction penetration is calculated with the critical hydraulic gradient method through FEA. The simulation results of the penetration process show that the integrated suction foundation can be installed safely. Moreover, the uplift resistance of the integrated suction foundation is calculated and the feasibility of the integrated suction foundation working on-site is verified. In all, the analysis in this work further approves the feasibility of the integrated suction foundation for TLPs in deep ocean applications.

  9. A suction detection system for rotary blood pumps based on the Lagrangian support vector machine algorithm.

    Science.gov (United States)

    Wang, Yu; Simaan, Marwan A

    2013-05-01

    The Left Ventricular Assist Device (LVAD) is a rotary mechanical pump that is implanted in patients with congestive heart failure to help the left ventricle in pumping blood in the circulatory system. However, using such a device may result in a very dangerous event, called ventricular suction that can cause ventricular collapse due to overpumping of blood from the left ventricle when the rotational speed of the pump is high. Therefore, a reliable technique for detecting ventricular suction is crucial. This paper presents a new suction detection system that can precisely classify pump flow patterns, based on a Lagrangian Support Vector Machine (LSVM) model that combines six suction indices extracted from the pump flow signal to make a decision about whether the pump is in suction, approaching suction, or not in suction. The proposed method has been tested using in vivo experimental data based on two different pumps. The simulation results show that the system can produce superior performance in terms of classification accuracy, stability, learning speed, and good robustness compared to three other existing suction detection methods and the original SVM-based algorithm. The ability of the proposed algorithm to detect suction provides a reliable platform for the development of a feedback control system to control the speed of the pump while at the same time ensuring that suction is avoided.

  10. Aquatic Research Laboratory (ARL)

    Data.gov (United States)

    Federal Laboratory Consortium — Columbia River and groundwater well water sources are delivered to the Aquatic Research Laboratory (ARL), where these resources are used to conduct research on fish...

  11. Aquatic Life Benchmarks

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Aquatic Life Benchmarks is an EPA-developed set of criteria for freshwater species. These benchmarks are based on toxicity values reviewed by EPA and used in the...

  12. Respiration in Aquatic Insects.

    Science.gov (United States)

    MacFarland, John

    1985-01-01

    This article: (1) explains the respiratory patterns of several freshwater insects; (2) describes the differences and mechanisms of spiracular cutaneous, and gill respiration; and (3) discusses behavioral aspects of selected aquatic insects. (ML)

  13. Molecular ecology of aquatic microbes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    Abstracts of reports are presented from a meeting on Molecular Ecology of Aquatic Microbes. Topics included: opportunities offered to aquatic ecology by molecular biology; the role of aquatic microbes in biogeochemical cycles; characterization of the microbial community; the effect of the environment on aquatic microbes; and the targeting of specific biological processes.

  14. Flow Modification over Rotor Blade with Suction Boundary Layer Control Technique

    Directory of Open Access Journals (Sweden)

    Navneet Kumar

    2016-06-01

    Full Text Available The efficiency of transonic aircraft engines depend upon the performance of compressor rotor. To increase compressor rotors performance flow separation around rotor blades must be delayed and controlled. The aim was to control the flow separation of blades using suction boundary layer control method. Rotor blade has been modelled in designing software CATIA and then a suction surface has been created on blade and then import these geometries to ANSYS-CFX 14.5 for computational analysis of flow around blades. Suction slot has been applied at the trailing edge of suction surface and Shear stress transport model has been used for computational analysis. Two different suction mass flow rates 1 kg/s and 1.5 kg/s have been used here and boundary layer separation effects have been changed and this could be readily seen that the velocity vectors have reattached, preventing the boundary layer separation at the suction surface of the blade.

  15. Centrifugal experimental study of suction bucket foundations under dynamic loading

    Science.gov (United States)

    Lu, Xiaobing; Wu, Yongren; Jiao, Bintian; Wang, Shuyun

    2007-12-01

    Centrifugal experiments were carried out to investigate the responses of suction bucket foundations under horizontal and vertical dynamic loading. It is shown that when the loading amplitude is over a critical value, the sand at the upper part around the bucket is softened or even liquefied. The excess pore pressure decreases from the upper part to the lower part of the sand layer in the vertical direction and decreases radially from the bucket’s side wall in the horizontal direction. Large settlements of the bucket and the sand layer around the bucket are induced by dynamic loading. The dynamic responses of the bucket with smaller height (the same diameter) are heavier.

  16. Radon Sub-slab Suctioning System Integrated in Insulating Layer

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2013-01-01

    of prefabricated lightweight elements were introduced and demonstrated. The principle was demonstrated on a concrete ground slab floor with a concrete slab on top of a thermal insulation layer above a capillary-breaking layer mounted on stable ground. The thermal insulation and the capillary-breaking layer...... consisted of a rigid insulation material. The new solution integrates the capillary-breaking layer and a pressure reduction zone,denoted the radon–suctioning layer, in one element. The new solution introduces the radonsuctioning layer as a horizontal grid of air ducts with low pressure to catch air...

  17. Studies of stability of blade cascade suction surface boundary layer

    Institute of Scientific and Technical Information of China (English)

    DONG Xue-zhi; YAN Pei-gang; HAN Wan-jin

    2007-01-01

    Compressible boundary layers stability on blade cascade suction surface was discussed by wind tunnel experiment and numerical solution. Three dimensional disturbance wave Parabolized Stability Equations(PSE) of orthogonal Curvilinear Coordinates in compressible flow was deducted. The surface pressure of blade in wind tunnel experiment was measured. The Falkner-Skan equation was solved under the boundary conditions of experiment result, and velocity, pressure and temperature of average flow were obtained. Substituted this result for discretization of the PSE Eigenvalue Problem, the stability problem can be solved.

  18. Radon Sub-slab Suctioning System Integrated in Insulating Layer

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    This poster presents a new radon sub-slab suctioning system. This system makes use of a grid of horizontal pressurised air ducts located within the lower part of the rigid insulation layer of the ground floor slab. For this purpose a new system of prefabricated lightweight elements is introduced....... The system is shown to be effective in preventing radon from polluting the indoor air by introducing low pressure in the horizontal grid of air ducts. How to implement and use the system in an effective way is described....

  19. Oronasopharyngeal suction at birth: effects on arterial oxygen saturation.

    Science.gov (United States)

    Carrasco, M; Martell, M; Estol, P C

    1997-05-01

    The effect of oronasopharyngeal suction (ONPS) on arterial oxygen saturation (SaO2) is described in a controlled study of 30 normal term newborn infants. In 15 of them, ONPS was performed immediately after birth. The SaO2 value was recorded through a pulse oximeter. The ONPS group had a significantly lower SaO2 between the first and the sixth minutes of life and took longer to reach 86% and 92% saturation. According to this study, ONPS should not be performed as a routine procedure in normal, term, vaginally born infants.

  20. Aquatic Plant Control Research Program. Allelopathic Aquatic Plants for Aquatic Plant Management: A Feasibility Study

    Science.gov (United States)

    1989-10-01

    block number) FIELD GROUP SUB-GROUP Allelopathy "Bioassay . Growth inhibition. Aquatic macrophytes. Biocontrol Lena minor 19. ABSTRACT (Continue on...Bibliography of Aquatic Plant Allelopathy ........ Al 2 ALLELOPATHIC AQUATIC PLANTS FOR AQUATIC PLANT MANAGEMENT; A FEASIBILITY STUDY Introduction Background 1...nutrients, water, and other biotic effects could have overriding effects that appear as competition or allelopathy . These biotic factors must be

  1. BASIC FLOW PATTERNS AND OPTIMUM HYDRAULIC DESIGN OF A SUCTION BOX OF PUMPING STATION

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A numerical method based on 3-D turbulence flow was applied to simulate the flow pattern in suction boxes of six different types.In light of the computational results, the basic flow patterns in the boxes were revealed and a theoretical method to optimize hydraulically design of the suction box is developed.The box geometrical parameters, which influence the flow pattern in the box, could be optimized.The optimum criteria for the hydraulic design of the suction boxes of six types established, respectively.Furthermore, a summarization is given here based on the classification of the basic flow patterns in order to systematically understand the hydraulic design of suction boxes.

  2. Numerical Investigation on Aerodynamic Force of Streamlined Box Girder with Uniform Air Suction

    Directory of Open Access Journals (Sweden)

    Tang Ke

    2014-06-01

    Full Text Available In the present study, the flow around a streamlined box girder with uniform air suction has been investigated numerically. Two-dimensional incompressible unsteady Reynolds averaged Navier-Stokes (URANS equations are solved in conjunction with the SST k −ω turbulence model in simulations. Taking the Great Belt Bridge girder as an example, cases of different suction positions on the girder section were discussed. The effect of the suction ratio and the angle of attack (AOA of wind also were investigated. The result showed that the aerodynamic drag force was influenced by the uniform suction through either upper surface or lower surface of the box girder. The larger the suction ratio was, the more the drag-reducing could be. The suction position and AOA had a comprehensive effect on the drag force. The vortex shedding frequency was also affected by air suction. For the aerodynamic lift force and moment, air suction showed no obvious influence. If necessary, using a combined suction scheme to reduce the aerodynamic drag force or to control the flow wake would be more efficient in engineering design.

  3. Use of a Yankauer suction tip combined with the Colpo-Pneumo Occluder balloon to suction the surgical field at the vaginal cuff during robotic hysterectomy.

    Science.gov (United States)

    Stitely, Michael L; Hashmi, Mahreen; Jain, Preiya; Hochberg, Charles

    2011-01-01

    A 39-year-old patient with complex endometrial hyperplasia without atypia underwent robotic total laparoscopic hysterectomy with bilateral salpingo-oophorectomy. The procedure was technically challenging because of the patient's obesity (body mass index 50 kg/m(2)). Concomitant suction of pooled blood and retraction of bowel and omentum were necessary to close the vaginal cuff. An endoscopic retractor was used through the assistant's port, and a Yankauer suction tip was placed through an inflated Colpo-Pneumo Occluder balloon in the vagina to provide directed suction to the vagina cuff. This technique enabled efficient closure of the vaginal cuff.

  4. Suction based mechanical characterization of superficial facial soft tissues.

    Science.gov (United States)

    Weickenmeier, J; Jabareen, M; Mazza, E

    2015-12-16

    The present study is aimed at a combined experimental and numerical investigation of the mechanical response of superficial facial tissues. Suction based experiments provide the location, time, and history dependent behavior of skin and SMAS (superficial musculoaponeurotic system) by means of Cutometer and Aspiration measurements. The suction method is particularly suitable for in vivo, multi-axial testing of soft biological tissue including a high repeatability in subsequent tests. The campaign comprises three measurement sites in the face, i.e. jaw, parotid, and forehead, using two different loading profiles (instantaneous loading and a linearly increasing and decreasing loading curve), multiple loading magnitudes, and cyclic loading cases to quantify history dependent behavior. In an inverse finite element analysis based on anatomically detailed models an optimized set of material parameters for the implementation of an elastic-viscoplastic material model was determined, yielding an initial shear modulus of 2.32kPa for skin and 0.05kPa for SMAS, respectively. Apex displacements at maximum instantaneous and linear loading showed significant location specificity with variations of up to 18% with respect to the facial average response while observing variations in repeated measurements in the same location of less than 12%. In summary, the proposed parameter sets for skin and SMAS are shown to provide remarkable agreement between the experimentally observed and numerically predicted tissue response under all loading conditions considered in the present study, including cyclic tests.

  5. A novel shaft-less double suction mini pump

    Institute of Scientific and Technical Information of China (English)

    NISHI; Michihiro

    2010-01-01

    A novel double suction shaft-less mini pump was developed for heat control of small energy systems in this study.The mini pump impeller with an exit diameter of 40 mm was combined with the motor rotor supported by the hybrid dynamic bearing.The specific speed of the pump was 125 min-1 m3 min-1 m.The hydraulic performance of the pump was investigated experimen-tally under four rotational speeds.From the test results,it was recognized that the pump could provide a flow discharge of 5 L/min and head of 1.5 m,which are applicable for the heat control system of a 3 kW fuel cell.A three-dimensional turbulent flow simulation in the pump was also conducted near the design point.The numerical results showed that the average hydraulic performance of the mini pump was predicted reasonably.From the internal flow simulation,it was revealed that the favorable inflow condition upstream of impeller inlet could be attained by applying the double suction shaft-less design for the mini pump.

  6. The impact of soil suction variation on earthquake intensity indices

    Directory of Open Access Journals (Sweden)

    Biglari Mahnoosh

    2016-01-01

    Full Text Available Soil properties can completely change the ground motion characteristics as they travel from the bedrock to the surface because, soil as a low-pass filter, may amplify or deamplify seismic motions in some frequencies on the wave travelling path. Recent studies about the advanced unsaturated soil mechanics clearly shows that dynamic properties of soils, including small-strain shear modulus (Gmax, shear modulus reduction (G/Gmax, and damping ratio (D curves are affected by changes in the soil suction level. The current study present nonlinear time-dependent analysis of three different unsaturated soils available in the literature with different ranges of nonlinear behaviour that earlier have been studied on unsaturated dynamic models. Since, the earthquake intensity parameters can be used to describe the damage potential of an earthquake, the focus of this paper is to evaluate the impact of the suction variation on the engineering ground motion parameters, including peak values of strong motion, Vmax/Amax, root-mean-square acceleration, Arias intensity, characteristic intensity, cumulative absolute velocity, acceleration spectrum intensity, effective design acceleration, A95 parameter and predominant period separately under the near-field and the far-field seismicity categories.

  7. Failure Loci of Suction Caisson Foundations Under Combined Loading Conditions

    Institute of Scientific and Technical Information of China (English)

    WANG Dong; JIN Xia

    2008-01-01

    Suction caissons are widely used to support offshore fixed platforms in coastal areas. The loadings transferred to suction caissons include the eccentric lateral force induced by waves and self weight of the platform structure. However, under this kind of combined loading conditions, the failure mechanism of caissons with shallow embedment depths is quite different from conventional deep foundations or onshore shallow footings. The behaviour of caissons subjected to combined loadings may be described with the "failure locus" in force resultant spaces. Here the failure loci of smooth caissons are studied by use of finite element approach, with the embedment ratio of caissons varying in the range of 0.25~1.0 and eccentricity ratio of horizontal loadings in 0~10. The platform settlement and tilt limits are involved into determination of failure loci, thus the platforms can avoid significant displacements for the combined loadings located inside the failure locus. Three families of loading paths are used to map out the locus. It is found that the shape of failure loci depends on 3 non-dimensional parameters, and the failure locus of a given caisson changes gradually from the elliptical curve to hooked curve with increasing shear strength of soil. The lateral capacity of short caissons may be enhanced by vertical forces, compared with the maximum lateral capacity of long caissons occurring at the vertical force being zero. The critical embedment ratios partitioning elliptical and hooked loci are proposed.

  8. An Ultrasonic Suction Pump with No Physically Moving Parts

    Science.gov (United States)

    Yun, Cheol-Ho; Hasegawa, Takeshi; Nakamura, Kentaro; Ueha, Sadayuki

    2004-05-01

    A new ultrasonic suction pump is described in this paper. The pump uses the suction force of a rigid cylinder tube vibrating at an ultrasonic frequency and has no physically moving parts. The pump consists of a longitudinal bolt-clamped Langevin transducer (BLT) combined with a stepped horn working at a resonance frequency of 24 kHz. A glass tube with the length of the half-wavelength-resonance is glued at the tip of the horn. To enhance pump performance, we introduced a reflection plate and a thin rod installed to the end of the glass tube with a small gap. Maximum pressures of 7.2 kPa and 23.5 kPa were recorded using the reflection plate and the thin rod, respectively. In this study, we experimentally investigate the characteristics of the pump and the operating physics. The maximum pressure is a function of the vibration velocity of the end surface of the glass tube and of the gap.

  9. Dynamic stiffness of suction caissons - torsion, sliding and rocking

    Energy Technology Data Exchange (ETDEWEB)

    Ibsen, Lars Bo; Liingaard, M.; Andersen, Lars

    2006-12-15

    This report concerns the dynamic soil-structure interaction of steel suction caissons applied as foundations for offshore wind turbines. An emphasis is put on torsional vibrations and coupled sliding/rocking motion, and the influence of the foundation geometry and the properties of the surrounding soil is examined. The soil is simplified as a homogenous linear viscoelastic material and the dynamic stiffness of the suction caisson is expressed in terms of dimensionless frequency-dependent coefficients corresponding to the different degrees of freedom. The dynamic stiffness coefficients for the skirted foundation are evaluated by means of a three-dimensional coupled boundary element/finite element model. Comparisons with known analytical and numerical solutions indicate that the static and dynamic behaviour of the foundation are predicted accurately with the applied model. The analysis has been carried out for different combinations of the skirt length and the Poisson's ratio of the subsoil. Finally, the high-frequency impedance has been determined for future use in lumped-parameter models of wind turbine foundations in aero-elastic codes. (au)

  10. Successful closed suction drain management of a canine elbow hygroma.

    Science.gov (United States)

    Pavletic, M M; Brum, D E

    2015-07-01

    A 1-year-old castrated male St. Bernard dog presented to Angell Animal Medical Center with bilateral elbow hygromas which had been present for several weeks. The largest hygroma involving the left elbow was managed with a closed suction (active) drain system to continuously collapse the hygroma pocket over a 3-week period. Soft bedding was used to protect the elbows from further impact trauma to the olecranon areas. Following drain removal, there was no evidence of hygroma recurrence based on periodic examinations over an 18-month period. The smaller non-operated right elbow hygroma had slightly enlarged during this period. Closed suction drain management of the hygroma proved to be a simple and economical method of collapsing the left elbow hygroma. This closed drainage system eliminated the need for the postoperative bandage care required with the use of the Penrose (passive) drain method of managing elbow hygromas. The external drain tube should be adequately secured in order to minimise the risk of its inadvertent displacement.

  11. [Swimming pool suction injury: etiology, profylaxis and management].

    Science.gov (United States)

    Škach, J; Kašák, P; Šrám, J

    2015-01-01

    Swimming pool suction injuries are unique and rare with a substantive risk of fatal consequences. Little children under the age of 8 are the most frequent victims with serious injuries. Drownings of different seriousness are also a usual part of accidents. The case of a 19 year old man trapped in the gluteal area by a unsecured suction drainage hole illustrates the uniqueness of this problem in an interesting way. Prophylactic arrangements are well known but the problem is with their strict application. Fatal causes excluding drowning include hypovolemic shock from the sudden redistribution of intersticial fluid and blood and also the evisceration of the bowel and other abdominal organs. Localised often bizarre and large swellings and sufusions can be treated nonoperatively in the vast majority of cases. For the prevention of these injuries it is important to inform the public and increase their awareness to these injuries. It is also crucial for the correct management of these injuries a deeper awareness of this issue and a sharing of experiences and solutions with other experts.Key words: vacuum - accident - entrapment - compartment syndrome.

  12. Temperature Measurement in WTE Boilers Using Suction Pyrometers

    Directory of Open Access Journals (Sweden)

    Fabio Rinaldi

    2013-11-01

    Full Text Available The temperature of the flue-gas in the post combustion zone of a waste to energy (WTE plant has to be maintained within a fairly narrow range of values, the minimum of which is prescribed by the European Waste Directive 2000/76/CE, whereas the maximum value must be such as to ensure the preservation of the materials and the energy efficiency of the plant. A high degree of accuracy in measuring and controlling the aforementioned temperature is therefore required. In almost the totality of WTE plants this measurement process is carried out by using practical industrial thermometers, such as bare thermocouples and infrared radiation (IR pyrometers, even if affected by different physical contributions which can make the gas temperature measurements incorrect. The objective of this paper is to analyze errors and uncertainties that can arise when using a bare thermocouple or an IR pyrometer in a WTE plant and to provide a method for the in situ calibration of these industrial sensors through the use of suction pyrometers. The paper describes principle of operation, design, and uncertainty contributions of suction pyrometers, it also provides the best estimation of the flue-gas temperature in the post combustion zone of a WTE plant and the estimation of its expanded uncertainty.

  13. Effect of suction pipe leaning angle and water level on the internal flow of pump sump

    Science.gov (United States)

    Chen, Z.-M.; Lee, Y.-B.; Kim, K.-Y.; Park, S.-H.; Choi, Y.-D.

    2016-11-01

    The pump sump, which connects forebay and intake of pump station, supplies good flow condition for the intake of the pump. If suction sumps are improperly shaped or sized, air entraining vortices or submerged vortices may develop. This may greatly affect pump operation if vortices grow to an appreciable extent. Moreover, the noise and vibration of the pump can be increased by the remaining of vortices in the pump flow passage. Therefore, the vortices in the pump flow passage have to be reduced for a good performance of pump sump station. In this study, the effect of suction pipe leaning angle on the pump sump internal flow with different water level has been investigated by CFD analysis. Moreover, an elbow type pipe was also investigated. There are 3 leaning angles with 0°, 45° and 90° for the suction pipe. The suction pipe inlet centre is kept same for all the cases. In addition, the three different water levels of H/D=1.85, 1.54, and 1.31, is applied to different suction pipe types. The result shows that the amount of air sucked into the suction pipe increases with increasing the suction pipe leaning angle. Especially for the horizontal suction pipe, there is maximum air sucked into the suction pipe. However, there is certain effect of the elbow type bell mouth installation in the horizontal suction pipe on suppressing the amount of air sucked into the pipe. Moreover, vertical suction pipe plays an effective role on reducing the free surface vortex intake area.

  14. Theoretical and Experimental Teaching Reform and Thinking of Aquatic Animal Nutrition and Feed Science Course%《水产动物营养与饲料学》课程理论与实验教学的改革与思考

    Institute of Scientific and Technical Information of China (English)

    任洪涛

    2013-01-01

    In order to stimulate students′interest in learning Aquatic Animal Nutrition and Feed Science course and improve the teaching effect, the teaching content, teaching methods and assessment methods were reformed in teaching practice. Recent progress and new technologies were introduced in teaching content to stimulate the students′initiative. Multimedia and internet technology was comprehensively applied to enhance teaching intuitiveness. Opening experimental content was set to improve creative ability of students. Assessment methods were reformed to stimulate learning motivation.%为了激发学生对《水产动物营养与饲料学》课程的学习兴趣,提高教学效果,对该课程的教学内容、教学方法和考核方式进行了探索和教学实践。在教学内容上,引入该学科的研究进展和新技术,调动学生的主动性;应用多媒体网络技术,增强教学的直观性;开设开放性实验内容,提高学生的创新能力;改变考核方式,激发学生学习动力。

  15. Measuring the effects of cutter suction dredge operating parameters on minor losses due to fixed screens installed at the suction inlet

    OpenAIRE

    Lewis, Joshua Mark

    2014-01-01

    CIVINS One of the most efficient and versatile types of modern dredges is the cutter suction dredge. Specific regulations mandate the placement of screens over the suction mouth during dredging operations to prevent ordnance, wildlife, and other debris from entering the system; however, these screens change the operational capability of the dredge in the form of an additional minor loss. The goal of this experiment was to determine the effects of different dredge operating p...

  16. Cardiopulmonary and intracranial pressure changes related to endotracheal suctioning in preterm infants.

    Science.gov (United States)

    Durand, M; Sangha, B; Cabal, L A; Hoppenbrouwers, T; Hodgman, J E

    1989-06-01

    Although endotracheal (ET) suctioning is performed frequently in sick newborn infants, its effects on cardiorespiratory variables and intracranial pressure (ICP) have not been thoroughly documented in neonates greater than 24 h who were not paralyzed while receiving mechanical ventilation. This study evaluates these changes in preterm infants who required ventilatory assistance. We measured transcutaneous PO2 and PCO2 (PtcO2 and PtcCO2, respectively), intra-arterial BP, heart rate, ICP, and cerebral perfusion pressure (CPP) before, during, and for at least 5 min after ET suctioning in 15 low birth weight infants less than 1500 g and less than or equal to 30 days of age. One infant was studied twice. A suction adaptor was used to avoid disconnecting the patient from the ventilator and to attempt to minimize hypoxemia and hypercapnia during suctioning. The patients were studied in the supine position and muscle relaxants were not used. PtcO2 decreased 12.1% while PtcCO2 increased 4.7% 1 min after suctioning; however, greater increases in mean BP (33%) and ICP (117%) were observed during suctioning. CPP also increased during the procedure. ICP returned to baseline almost immediately, whereas BP remained slightly elevated 1 min after suctioning. Our findings demonstrate that ET suctioning significantly increases BP, ICP, and CPP in preterm infants on assisted ventilation in the first month of life. These changes appear to be independent of changes observed in oxygenation and ventilation.

  17. Micropolar boundary layer flow at a stagnation point on a moving wall with suction and injection

    Science.gov (United States)

    Hassanien, I. A.; Hady, F. M.

    1988-10-01

    The flow of a micropolar fluid at a two-dimensional stagnation point on a moving wall with suction and injection is studied. Numerical computations were carried out on a VME-2955 computer. The effects of the suction/injection parameter and dimensionless material parameters are discussed.

  18. The effects and safety of closed versus open tracheal suction system:a meta analysis

    Institute of Scientific and Technical Information of China (English)

    董亮

    2012-01-01

    Objective To evaluate the effects and safety of closed tracheal suction system (CTSS) versus open tracheal suction system(OTSS) for mechanically ventilated patients. Methods All randomized controlled trials (RCTs) comparing CTSS with OTSS for mechanically ventilated patients home and abroad

  19. Effects of suction-dredging for cockles on non-target fauna in the Wadden Sea

    NARCIS (Netherlands)

    Hiddink, JG

    2003-01-01

    Suction dredging for cockles removes large cockles from tidal flats and may also cause mortality of non-target fauna and make the habitat less suitable for some species. This study examines whether suction dredging for cockles on tidal flats of the Dutch Wadden Sea had affected densities of non-targ

  20. 46 CFR 134.180 - Piping for fire-main suction.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Piping for fire-main suction. 134.180 Section 134.180 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS ADDED PROVISIONS FOR LIFTBOATS § 134.180 Piping for fire-main suction. (a) Except as provided by paragraph (b) of...

  1. Tono-Pen XL tonometry during application of a suction ring in rabbits

    Directory of Open Access Journals (Sweden)

    Kounis Georgios A

    2008-07-01

    Full Text Available Abstract Background The purpose of this study is to evaluate the use of Tono-Pen XL in measuring IOP during the application of a suction ring in rabbit eyes with manometrically controlled IOP. Methods Tono-Pen XL was calibrated against direct manometry in 10 rabbit eyes. A suction ring was then applied in 4 rabbit eyes and the IOP was determined manometrically during suction ring application at 350 mmHg vacuum pressure. Finally, in 6 catheterized rabbit eyes the IOP was measured with Tono-Pen XL during suction ring application at suction vacuum from 350 to 650 mmHg, while keeping actual IOP stable at 30 mmHg and 60 mmHg. Results Linear regression analysis revealed that the Tono-pen XL was reliable for IOPs between 10 and 70 mmHg (R2 = 0.9855. Direct manometry during suction ring application showed no statistically significant variation of Tono-Pen XL readings when the incanulation manometry intraocular pressure changed from 30 mmHg to 60 mmHg and no statistically significant correlation between suction vacuum and IOP measurements. Conclusion Tono-Pen XL measurements are unreliable during the application of a suction ring on living rabbit eyes even when the actual IOP is forced to be within the validated range of Tono-Pen XL measurements. This inaccuracy is probably related to altered corneal and scleral geometry and stress.

  2. Stability of boundary layers with porous suction strips: Experiment and theory

    Science.gov (United States)

    Reynolds, G. A.; Saric, W. S.; Reed, H. L.; Nayfeh, A. H.

    1982-01-01

    Low turbulence tunnel experiments on the stability and transition of 2 D boundary layers on flat plates with and without suction are described. A number of general suction cases are discussed. Test results showed that the maximum stabilization occurred when the suction was moved toward the Branch I neutral point. An analytical study of the stability of two dimensional, incompressible boundary layer flows over plates with suction through porous strips was performed. The mean flow was calculated using linearized triple deck, closed form solutions. The stability results of the triple deck theory are shown to be in good agreement with those of the interacting boundary layers. An analytical optimization scheme for the suction configuration was developd. Numerical calculations were performed corresponding to the experimental configurations. In each case, the theory correctly predicts the experimental results.

  3. Seepage Study for Suction Installation of Bucket Foundation in Different Soil Combinations

    DEFF Research Database (Denmark)

    Koteras, Aleksandra Katarzyna; Ibsen, Lars Bo; Clausen, Johan Christian

    2016-01-01

    Research has proven the bucket foundation to be a feasible and an attractive solution for offshore wind turbines. Its potential derives partly from the cost-effectiveness due to the suction-assisted installation. The suction applied under the bucket lid produces a downward driving force...... solutions. A series of numerical simulations performed on the flow analysis around the bucket penetrating into sand are presented in this paper. The characteristics of seepage arising from applied suction are investigated. The cases included in the research cover a wide range of bucket dimensions...... around the bucket skirt. The exceedance of critical suction might lead to installation failure due to formation of piping channels, which break the hydraulic seal between the skirt and soil. The excess pore pressure arising due to applied suction changes the effective stress, hence the penetration...

  4. The suction pouch for management of simple or complex enterocutaneous fistulae.

    Science.gov (United States)

    Franklin, Christoph

    2010-01-01

    Containing effluent from an enterocutaneous fistula (ECF) requires expertise, critical thinking skills, and creativity. Using a combination of products readily available to WOC nurses practicing in the United States, I have designed a suction pouch that reliably contains fistula output. A standard ostomy pouch can be converted into a suction pouch by adding a large, single-lumen catheter into the pouch, sealing it, and connecting the assembly to low continuous suction. The resulting pouch can be used by itself to drain effluent from an ECF or it can be used in combination with wound dressings, or a negative pressure wound therapy system. Application of a suction pouch extends the integrity of the appliance and diverts succus away from the wound bed or the newly applied skin graft with increased reliability. This article describes the technique used to create a suction pouch, followed by 4 brief case descriptions that demonstrate feasibility of its use for the management of ECFs.

  5. The better to eat you with: the comparative feeding morphology of phocid seals (Pinnipedia, Phocidae).

    Science.gov (United States)

    Kienle, Sarah S; Berta, Annalisa

    2016-03-01

    One adaptation crucial to the survival of mammalian lineages that secondarily transitioned from land to water environments was the ability to capture and consume prey underwater. Phocid seals have evolved diverse feeding strategies to feed in the marine environment, and the objectives of this study were to document the specialized feeding morphologies and identify feeding strategies used by extant phocids. This study used principal component analysis (PCA) to determine the major axes of diversification in the skull for all extant phocid taxa and the recently extinct Caribbean monk seal (n = 19). Prey data gathered from the literature and musculoskeletal data from dissections were included to provide a comprehensive description of each feeding strategy. Random Forest analysis was used to determine the morphological, ecological and phylogenetic variables that best described each feeding strategy. There is morphological evidence for four feeding strategies in phocids: filter; grip and tear; suction; and pierce feeding. These feeding strategies are supported by quantitative cranial and mandibular characters, dietary information, musculoskeletal data and, for some species, behavioral observations. Most phocid species are pierce feeders, using a combination of biting and suction to opportunistically catch prey. Grip and tear and filter feeding are specialized strategies with specific morphological adaptations. These unique adaptations have allowed leopard seals (Hydrurga leptonyx) and crabeater seals (Lobodon carcinophaga) to exploit novel ecological niches and prey types. This study provides the first cranial and mandibular morphological evidence for the use of specialized suction feeding in hooded seals (Cystophora cristata), northern elephant seals (Mirounga angustirostris) and southern elephant seals (Mirounga leonina). The most important variables in determining the feeding strategy of a given phocid species were cranial and mandibular shape, diet, and phylogeny

  6. Method for mitigating the negative effect of vortex motion inside the suction chambers of centrifugal pumps

    Directory of Open Access Journals (Sweden)

    Adrian CIOCANEA

    2013-09-01

    Full Text Available The paper presents a method for mitigating the negative effect of vortex motion inside the suction chambers of centrifugal pumps in order to obtain better use of water resource and decrease the risk related to loss of prime. It was studied the influence of a rotating device on the vortex motion in the case of a vertical suction pipe. The device is consisting of three thin vertical cylinders symmetrically mounted on a horizontal rotating disk placed in front of the inlet section of the suction pipe. The experimental research was conducted for various diameters of the cylinders, water levels in the suction chamber and pump flow rates. It was assessed the vortex type, frequency of arising and living life of vortices. The experimental results are compared with the case the device is absent in order to assess the efficiency of the solution. By using the device a decrease of about 1215% of vortex arising is observed for most of the water levels in the suction chamber and for 80 -90 % of the centrifugal pump flow rates. If high flow rates and low water level in the suction chamber are simultaneously present, violent vortex motion is blocking the rotating device and the volume of air entered the pipe is massive - extreme regime. The flow pattern in the suction chamber was visualized using a laser sheet. At the inlet section of the suction pipe one can observe two main flow patterns: central vortex entrance for high water level in the suction chamber and reduce flow rates of the centrifugal pump and lateral vortex entrance for low water level and high flow rates. The conclusions of the experiment confirm the energy dissipation of the vortices arising in the suction chamber, due to utilization of the rotating device, in most of the centrifugal pump regimes.

  7. Aquatic Environment 2000

    DEFF Research Database (Denmark)

    Svendsen, L. M.; Bijl, L. van der; Boutrup, S.

    The report summarizes the results of the Danish Aquatic Monitoring and Assessment Programme 1998-2003. Danish Environmental Protection Agency 2000: NOVA-2003. Programbeskrivelse for det nationale program for overvågning af vandmiljøet 1998-2003. 397 pp. - Redegørelse fra Miljøstyrelsen nr. 1 (in...

  8. Aquatic Equipment Information.

    Science.gov (United States)

    Sova, Ruth

    Equipment usually used in water exercise programs is designed for variety, intensity, and program necessity. This guide discusses aquatic equipment under the following headings: (1) equipment design; (2) equipment principles; (3) precautions and contraindications; (4) population contraindications; and (5) choosing equipment. Equipment is used…

  9. Flow over plates with suction through porous strips

    Science.gov (United States)

    Nayfeh, A. H.; Reed, H. L.; Ragab, S. A.

    1980-01-01

    This paper addresses the steady, incompressible, two-dimensional flow past a flat plate with suction through porous strips. Closed-form solutions for each flow quantity are developed in the context of linearized triple-deck theory using Fourier transforms. To demonstrate the validity of these closed-form solutions, we compare the wall shear stress and pressure coefficients and the streamwise velocity profiles from the linearized theory with those obtained by the numerical integration of both interacting and nonsimilar boundary-layer equations. The agreement between the linearized triple-deck and interacting boundary-layer equations is good; however, the nonsimilar boundary layers, which fail to account for upstream influence, are shown to be in poor agreement with both interacting boundary layers and the linearized triple deck. The linearized closed-form solutions will therefore be very useful in future stability calculations.

  10. Suction blister grafting - Modifications for easy harvesting and grafting

    Directory of Open Access Journals (Sweden)

    2012-01-01

    Full Text Available Suction blister grafting is a simple modality of treatment of patients with resistant and stable vitiligo. But raising the blisters may be time consuming and transferring to the recipient site may be difficult as the graft is ultrathin. By doing some modifications we can make the technique simpler and easier. We can decrease the blister induction time by intradermal injection of saline, exposure to Wood′s lamp, intrablister injection of saline. By these methods we can decrease the blister induction time from 2-3 hrs to 45-90 minutes. After harvesting the graft, it can be transferred to the recipient area by taking the graft on a sterile glass slide, on the gloved finger, rolling the graft over a sterile syringe and then spreading on the recipient area, or taking on the sterile wrapper of paraffin dressing and then placing over the recipient area.

  11. Study on analysis of flow field in ejector suction pipe

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Noh Hyeong [GS Caltex Corporation, Seoul (Korea, Republic of)

    2012-10-15

    An ejector is a fluid transportation device that operates based on the principle that a high pressure fluid is spouted through a driving pipe and the pressure of a low pressure fluid is increased through exchange of momentum with a low pressure gas. Steam steam ejectors have been widely used for suction, mixture, and dehydration. They can be easily used in places where fluid moves and expenses are reasonable. In addition, such ejectors are a semi permanent fluid device that requires little maintenance. In this study, we present an optimized design by analyzing what cannot be obtained through experiments in order to improve the device performance, analyze general contents of a flow by acquiring exact test data on specific and interpretative areas using more advanced experimental techniques, and identify the flow characteristics of a branch pipe by examining the validity of experiments using computer hydrodynamics simulations.

  12. Centrifugal experimental study of suction bucket foundations under dynamic loading

    Institute of Scientific and Technical Information of China (English)

    Xiaobing Lu; Yongren Wu; Bintian Jiao; Shuyun Wang

    2007-01-01

    Centrifugal experiments were carded out to investigate the responses of suction bucket foundations under horizontal and vertical dynamic loading. It is shown that when the loading amplitude is over a critical value, the sand at the upper part around the bucket is softened or even liq-uefied. The excess pore pressure decreases from the upper part to the lower part of the sand layer in the vertical direc-tion and decreases radially from the bucket's side wall in the horizontal direction. Large settlements of the bucket and the sand layer around the bucket are induced by dynamic load-ing. The dynamic responses of the bucket with smaller height (the same diameter) are heavier.

  13. Localized travelling waves in the asymptotic suction boundary layer

    CERN Document Server

    Kreilos, Tobias; Schneider, Tobias M

    2016-01-01

    We present two spanwise-localized travelling wave solutions in the asymptotic suction boundary layer, obtained by continuation of solutions of plane Couette flow. One of the solutions has the vortical structures located close to the wall, similar to spanwise-localized edge states previously found for this system. The vortical structures of the second solution are located in the free stream far above the laminar boundary layer and are supported by a secondary shear gradient that is created by a large-scale low-speed streak. The dynamically relevant eigenmodes of this solution are concentrated in the free stream, and the departure into turbulence from this solution evolves in the free stream towards the walls. For invariant solutions in free-stream turbulence, this solution thus shows that that the source of energy of the vortical structures can be a dynamical structure of the solution itself, instead of the laminar boundary layer.

  14. Improved Suction Technique for the Characterization of Construction Materials

    DEFF Research Database (Denmark)

    Thygesen, Lisbeth Garbrecht; Hansen, Kurt Kielsgaard

    2007-01-01

    The suction technique is a method from soil science that is used for the study of moisture storage capacity in porous construction materials at high relative humidity levels (above approximately 93%). The samples to be studied are placed in a pressurized container (an extractor) on a water...... procedure for determining the equilibrium moisture content of samples during the experiment. The method (refered to as the balance method) is to simply keep track of all water entering and leaving the system and use these data to estimate the moisture content of the samples. The advantage of this approach...... is that the experiment does not need to be stopped and restarted for each relative humidity level tested. The main disadvantage of the method is that the estimation of the moisture content in the samples depends on a correct estimation of the moisture content of the ceramic disc. The second adjustment is the development...

  15. Introduced aquatic plants and algae

    Science.gov (United States)

    Non-native aquatic plants such as waterhyacinth and hydrilla severely impair the uses of aquatic resources including recreational faculties (lakes, reservoirs, rivers) as well as timely delivery of irrigation water for agriculture. Costs associated with impacts and management of all types of aquatic...

  16. Aquatic Plants and their Control.

    Science.gov (United States)

    Michigan State Dept. of Natural Resources, Lansing.

    Aquatic plants can be divided into two types: algae and macrophytes. The goal of aquatic plant management is to maintain a proper balance of plants within a lake and still retain the lake's recreational and economic importance. Aquatic plant management programs have two phases: long-term management (nutrient control), and short-term management…

  17. [Development of oral feeding skills in the preterm infant].

    Science.gov (United States)

    Lau, C

    2007-09-01

    Preterm infants cannot readily transition from tube to oral feeding. Such difficulty often delays their discharge from the hospital and mother-infant reunion. Therefore, understanding the development of the necessary skills preterm infants need to acquire for safe and successful oral feeding is essential. It is now recognized that a mature sucking pattern consisting of the rhythmic alternation of suction and expression is not sufficient for an infant to feed by mouth safely. Rather, an adequate coordination of sucking, swallowing, and respiration appear to be crucial if the infant is to feed with no episodes of desaturation, apnea, bradycardia, and/or aspiration. Studies have shown the benefits of some interventions in facilitating oral feeding in the preterm infant. However, it remains to be determined whether these effects can be generalized.

  18. A computed tomographic scan assessment of endotracheal suctioning-induced bronchoconstriction in ventilated sheep.

    Science.gov (United States)

    Lu, Q; Capderou, A; Cluzel, P; Mourgeon, E; Abdennour, L; Law-Koune, J D; Straus, C; Grenier, P; Zelter, M; Rouby, J J

    2000-11-01

    This study was directed at assessing changes in bronchial cross-sectional surface areas (BCSA) and in respiratory resistance induced by endotracheal suctioning in nine anesthetized sheep. Cardiorespiratory parameters (Swan-Ganz catheter), respiratory resistance (inspiratory occlusion technique), BCSA, and lung aeration (computed tomography) were studied at baseline, during endotracheal suctioning, and after 20 consecutive hyperinflations. Measurements performed initially at an inspired oxygen fraction (FI(O(2))) of 0.3 were repeated at an FI(O(2)) of 1.0. At an FI(O(2)) of 0.3, endotracheal suctioning resulted in atelectasis, a reduction in BCSA of 29 +/- 23% (mean +/- SD), a decrease in arterial oxygen saturation from 95 +/- 3% to 87 +/- 12% (p = 0.02), an increase in venous admixture from 19 +/- 10% to 31 +/- 19% (p = 0. 006), and an increase in lung tissue resistance (DR(rs)) (p = 0. 0003). At an FI(O(2)) of 1.0, despite an extension of atelectasis and an increase in pulmonary shunt from 19 +/- 5% to 36 +/- 2% (p sheep, the endotracheal suctioning-induced reduction of BCSA was entirely prevented. These data suggest that the endotracheal suctioning-induced decrease in BCSA is related to atelectasis and bronchoconstriction. Both effects can be reversed by hyperoxygenation maneuver before suctioning in combination with recruitment maneuver after suctioning.

  19. Scaling macroscopic aquatic locomotion

    Science.gov (United States)

    Gazzola, Mattia; Argentina, Mederic; Mahadevan, Lakshminarayanan

    2014-11-01

    Inertial aquatic swimmers that use undulatory gaits range in length L from a few millimeters to 30 meters, across a wide array of biological taxa. Using elementary hydrodynamic arguments, we uncover a unifying mechanistic principle characterizing their locomotion by deriving a scaling relation that links swimming speed U to body kinematics (tail beat amplitude A and frequency ω) and fluid properties (kinematic viscosity ν). This principle can be simply couched as the power law Re ~ Swα , where Re = UL / ν >> 1 and Sw = ωAL / ν , with α = 4 / 3 for laminar flows, and α = 1 for turbulent flows. Existing data from over 1000 measurements on fish, amphibians, larvae, reptiles, mammals and birds, as well as direct numerical simulations are consistent with our scaling. We interpret our results as the consequence of the convergence of aquatic gaits to the performance limits imposed by hydrodynamics.

  20. Spatial distribution and functional feeding groups of aquatic insect communities in Serra da Bocaina streams, southeastern Brazil Distribuição espacial e categorização funcional trófica de comunidades de insetos aquáticos em rios na Serra da Bocaina, Sudeste Brasil

    Directory of Open Access Journals (Sweden)

    Ana Lucia Henriques de Oliveira

    2010-12-01

    Full Text Available AIM: The aim of this paper was to study the spatial distribution and functional feeding structure of aquatic insect communities of 18 streams at different altitudes in Mambucaba River Basin, Serra da Bocaina, Southeastern Brazil; METHODS: Samples were collected in two consecutive dry periods (August of 2003 and 2004 being sampled four substrate types in each stream: litter from riffles, litter from pools, rocks and gravel; RESULTS: We identified 75,581 aquatic insect individuals belonging to 201 taxa. Most of the fauna was found in litter substrates (64%, and riffle litter substrate had the majority of the specimens (32,572 individuals. Gravel was the substrate with highest values of richness (29.84 taxa expected for 187 individuals; rarefaction method and Shannon's diversity (H' = 2.370. Rock substrate showed the lowest richness (20.24 taxa. Distribution of taxa across substrates shows that only 28 taxa are restricted to a single substrate, while 78 taxa occurred in all substrates. The indicator analysis showed that 20 taxa were characteristic of pool litter, 25 of riffle litter, 22 of gravel and only nine to rock. In relation to organic and inorganic substrates, 29 taxa were characteristic of litter, and 17 of inorganic substrates. Cluster analysis based on Bray-Curtis dissimilarity index and UPGMA linkage method showed that aquatic insects were distributed according to substrate and food resource. In all substrates, the main functional feeding group was collector-gatherer (40.64%, and the least representative was shredder (6.67%. ANOVA and Tukey HSD tests showed that collector-gatherers and shredders were predominant in pool substrates, collector-filters in riffle substrate and scrapers in hard substrates; CONCLUSION: Ours results show that independently of stream or altitude, substrate of the same type have similar faunal assemblages. The abundance and relative proportion of the functional feeding group showed variation across habitats

  1. Numerical Buckling Analysis of Large Suction Caissons for Wind Turbines on Deep Water

    DEFF Research Database (Denmark)

    Madsen, Søren; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

    2013-01-01

    the suction caisson is loaded by external pressure (internal suction) due to evacuation of water inside the bucket and vertical forces due to gravity. The risk of structural buckling during installation of large-diameter suction caissons is addressed using numerical methods. Initial imperfect geometries...... are introduced, based on the buckling mode shapes from a linear eigenvalue buckling analysis. Different imperfect geometries are introduced to reveal how sensitive the buckling load is to these imperfections. Including the first 21 mode shapes as imperfect geometries will reduce the buckling pressure compared...... to only considering mode 1. The results of the finite element analysis are compared with current standards for evaluating buckling loads....

  2. An improvised two in one syringe suction drain for surgeries of extremities.

    Directory of Open Access Journals (Sweden)

    Kamath J

    2005-01-01

    Full Text Available Use of an improvised two in one syringe suction drain is being presented for a case with two adjacent non-communicating surgical wounds following release of Duputryn′s contracture primarily involving the longitudinal band of the palmar fascia of the hand, in line with the middle and ring finger. Instead of using two separate closed suction drainage system we modified our method by using a 3 way cannula which could accept 2 draining tubes to be connected to one 50cc syringe with negative suction pressure.

  3. A compliant underactuated hand with suction flow for underwater mobile manipulation

    KAUST Repository

    Stuart, Hannah S.

    2014-05-01

    © 2014 IEEE. Fingertip suction is investigated using a compliant, underactuated, tendon-driven hand designed for underwater mobile manipulation. Tendon routing and joint stiffnesses are designed to provide ease of closure while maintaining finger rigidity, allowing the hand to pinch small objects, as well as secure large objects, without diminishing strength. While the hand is designed to grasp a range of objects, the addition of light suction flow to the fingertips is especially effective for small, low-friction (slippery) objects. Numerical simulations confirm that changing suction parameters can increase the object acquisition region, providing guidelines for future versions of the hand.

  4. Linear stability analysis of Poiseuille flow in porous medium with small suction and injection

    CERN Document Server

    Hinvi, L A; Orou, J B Chabi

    2014-01-01

    We investigate the effect of small suction Reynolds number and permeability parameter on the stability of Poiseuille fluid flow in a porous medium between two parallel horizontal stationary porous plates . We have shown that the perturbed flow is governed by an equation named modified Orr-Sommerfeld equation. We find also that the normalization of the wall-normal velocity with characteristic small suction (or small injection) velocity is important for a perfect command of porous medium fluid flow stability analysis. The stabilizing effect of the parameters in general and small suction Reynolds number and permeability parameters in particular on the linear stability are found.

  5. A law of the wall for turbulent boundary layers with suction: Stevenson's formula revisited

    Science.gov (United States)

    Vigdorovich, Igor

    2016-08-01

    The turbulent velocity field in the viscous sublayer of the boundary layer with suction to a first approximation is homogeneous in any direction parallel to the wall and is determined by only three constant quantities — the wall shear stress, the suction velocity, and the fluid viscosity. This means that there exists a finite algebraic relation between the turbulent shear stress and the longitudinal mean-velocity gradient, using which as a closure condition for the equations of motion, we establish an exact asymptotic behavior of the velocity profile at the outer edge of the viscous sublayer. The obtained relationship provides a generalization of the logarithmic law to the case of wall suction.

  6. 不同蛋白质源对高蛋白质水产饲料膨化工艺参数和加工质量的影响%Effects of Different Protein Sources on Extrusion Processing Parameters and Processing Quality for High Protein Aquatic Feed

    Institute of Scientific and Technical Information of China (English)

    梁晓芳; 李军国; 薛敏; 王嘉; 吴秀峰; 郑银桦; 韩芳; 秦玉昌

    2016-01-01

    In this study, we determined the effects of fish meal ( FM) , cottonseed protein concentrate ( CPC) and fermented soybean meal ( FSM) formulated as sole or combined protein sources in aquatic feed on the ex⁃trusion processing parameters and processing quality. Extrusion processing was conducted by a twin⁃screw ex⁃truder with steam heating and pre⁃conditioning system. FM diet was set as control diet, CPC and FSM were sole or combined used to replace 47% or 100% of FM, and then, seven diets with 45.45% to 48.55% crude protein and 18.11 to 20.33 MJ/kg gross energy were formulated and named as FM, FM×CPC, FM×FSM, CPC, FM×CPC×FSM, FSM and CPC×FSM, respectively. The results showed that the reduction of extrusion temperature and increase of screw speed and energy consumption were caused after the FM was replaced by plant proteins. With the plant protein proportion increasing, the extrusion temperature was reduced, and there was a significant negative correlation between them ( R2=0.926 2) . Processing quality parameters except dura⁃ble index of extrusion feed were significantly affected by different protein sources. The bulk density and stabili⁃ty in water in FM group were significantly higher than those in other group ( P<0.05) . On the contrary, with the increase of plant protein proportion, hardness and expansion degree of extrusion feed were increased. More⁃over, the radial expansion degree in CPC group was significantly higher than that in other groups ( P< 0.05) , and there was a significant positive correlation between the supplementation of fermented soybean meal and hardness of extrusion feed (R2=0.978 1). In conclusion, both FSM and CPC can significantly increase feed radial expansion and energy consumption compared with FM. Moreover, the bulk density of CPC is significant⁃ly lower than that of FSM and FM, which is beneficial to the production of floating feed, but not good to the production of sinking feed.%

  7. Study on the performance improvement of multiblade fans. Effects of suction cones; Tayoku fan no seino kaizen ni kansuru kenkyu. Suction cone no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Kuratani, F.; Ogawa, T. [Hyogo University of Teacher Education, Hyogo (Japan); Yamamoto, S.

    1999-07-25

    In order to improve the performance of a multiblade fan, the effects of three types of suction cones of the fan casing on the fan efficiency and noise are investigated experimentally. The first type of the suction cone is the insertion type, which is inserted into the inside of the fan impeller. The second type is the extrusion type, which extrudes outside from the casing surface. The third type is the combination type of two types. The results of those three types are compared with those of the commonly used suction cone. The followings are made clear: (1) The insertion type and the extrusion type are effective in improving the efficiency and reducing noise. (2) The optimal lengths of the insertion and the extrusion exist. (3) The combination type is more effective in improving the efficiency. (4) The combination type with the skewed cutoff of the fan casing shows the best effect. (author)

  8. Evaluation of Karl Storz CMAC TipTM Device Versus Traditional Airway Suction in a Cadaver Model

    Directory of Open Access Journals (Sweden)

    Demis N. Lipe

    2014-07-01

    Full Text Available Introduction: We compared the efficacy of Karl Storz CMAC TipTM with inline suction to CMAC with traditional suction device in cadaveric models simulating difficult airways, using media mimicking pulmonary edema and vomit. Methods: This was a prospective, cohort study in which we invited emergency medicine faculty and residents to participate. Each participant intubated 2 cadavers (one with simulated pulmonary edema and one with simulated vomit, using CMAC with inline suction and CMAC with traditional suction. Thirty emergency medicine providers performed 4 total intubations each in a crossover trial comparing the CMAC with inline suction and CMAC with traditional suction. Two intubations were performed with simulated vomit and two with simulated pulmonary edema. The primary outcome was time to successful intubation; and the secondary outcome was proportion of successful intubation. Results: The median time to successful intubation using the CMAC with inline suction versus traditional suction in the pulmonary edema group was 29s and 30s respectively (p=0.54. In the vomit simulation, the median time to successful intubation was 40s using the CMAC with inline suction and 41s using the CMAC with traditional suction (p=0.70. There were no significant differences in time to successful intubation between the 2 devices. Similarly, the proportions of successful intubation were also not statistically significant between the 2 devices. The proportions of successful intubations using the inline suction were 96.7% and 73.3%, for the pulmonary edema and vomit groups, respectively. Additionally using the handheld suction device, the proportions for the pulmonary edema and vomit group were 100% and 66.7%, respectively. Conclusion: CMAC with inline suction was no different than CMAC with traditional suction and was associated with no statistically significant differences in median time to intubation or proportion of successful intubations. [West J Emerg Med

  9. Mass-Transfer Characteristics of Air- Suction Type Fermentors

    Directory of Open Access Journals (Sweden)

    Alaa K. M.

    2008-01-01

    Full Text Available Liquid-side mass-transfer coefficients (KLa were measured in air-suction type fermentors using physical absorption of oxygen. A fermentor of 0. 5 m i.d. was used with a working capacity of 60 liters of liquid. Tap water was used as the liquid phase, and air was used as the gas phase. The bioreactor mixing system consists of shrouded-disk/curved-blade turbine with six evacuated bending blades. The effect of liquid submergence (S was investigated. Further, the effects of the ratio of the impeller diameter (D to the tank diameter (T, and the clearance of the impeller from the tank bottom(C were also studied. The agitation speed (N was varied in the range of 50-800 rpm. It was found that the value of KLa increased as the impeller diameter increased, while it was decreased continuously with increasing the clearance. The effect of impeller submergence on the value of mass transfer coefficient (KLa is not much pronounced.Suitable correlation was developed for estimating mass transfer coefficient (KLa in this type of bioreactors.

  10. Closed versus partially ventilated endotracheal suction in extremely preterm neonates: physiologic consequences.

    Science.gov (United States)

    Tan, A M; Gomez, J M; Mathews, J; Williams, M; Paratz, J; Rajadurai, V S

    2005-08-01

    This randomized cross over study aimed to compare the severity and incidences of desaturation and bradycardia between the partially ventilated endotracheal suction method (PVETS) and closed tracheal suction system (CTSS) in extremely preterm neonates. Fifteen intubated and ventilated extremely low birth weight preterm infants (mean birth weight 689g) randomly underwent both suction techniques within a 12-h period to obtain a paired reading group. The process was repeated 24-48h apart until three pairs of reading groups were collected. Changes in oxygen saturation measured with pulse oximetry and heart rate changes measured with electrocardiogram were recorded using Hewlett-Packard m240A monitor trending software. The mean of each parameter's variation from baseline was obtained using SPSS descriptive statistics and analyzed using SPSS repeated measures ANOVA. Fisher Exact Test was used to analyze the incidence of desaturation and bradycardia. The closed tracheal suction system reported a significantly smaller degree of oxygen saturation fall (Ppreterm population.

  11. Volume of blood suctioned during vacuum-assisted breast biopsy predicts later hematoma formation

    Directory of Open Access Journals (Sweden)

    Panopoulou Effrosyni

    2010-03-01

    Full Text Available Abstract Background To evaluate whether the volume of blood suctioned during vacuum-assisted breast biopsy (VABB is associated with hematoma formation and progression, patient's age and histology of the lesion. Findings 177 women underwent VABB according to standardized protocol. The volume of blood suctioned and hematoma formation were noted at the end of the procedure, as did the subsequent development and progression of hematoma. First- and second-order logistic regression was performed, where appropriate. Cases with hematoma presented with greater volume of blood suctioned (63.8 ± 44.7 cc vs. 17.2 ± 32.9 cc; p Conclusion The likelihood of hematoma is increasing along with increasing amount of blood suctioned, reaching a plateau approximately at 80 cc of blood lost.

  12. Aerodynamic Drag Reduction for A Generic Sport Utility Vehicle Using Rear Suction

    Directory of Open Access Journals (Sweden)

    Abdellah Ait Moussa

    2014-08-01

    Full Text Available The high demand for new and improved aerodynamic drag reduction devices has led to the invention of flow control mechanisms and continuous suction is a promising strategy that does not have major impact on vehicle geometry. The implementation of this technique on sport utility vehicles (SUV requires adequate choice of the size and location of the opening as well as the magnitude of the boundary suction velocity. In this paper we introduce a new methodology to identifying these parameters for maximum reduction in aerodynamic drag. The technique combines automatic modeling of the suction slit, computational fluid dynamics (CFD and a global search method using orthogonal arrays. It is shown that a properly designed suction mechanism can reduce drag by up to 9%..

  13. Suction removal of sediment from between armour blocks. Part 2. Waves

    DEFF Research Database (Denmark)

    Dixen, Figen Hatipoglu; Sumer, B. Mutlu; Fredsøe, Jørgen

    2008-01-01

    When a stone/armor layer on a sand bed is exposed to flow, the sand underneath will be agitated by the flow turbulence. When the flow velocity reaches a critical value, the sand will be sucked (winnowed out) from between the armor blocks. In a previous investigation, we studied suction removal...... of sediment in steady currents. The present study is an extension of our previous investigation to waves. The critical condition for the onset of suction is determined. It is found that the onset of suction is governed by three parameters: (1) the sediment mobility number (based on the sediment size); (2......) the ratio of sediment size to stone size, d/D; and (3) the Keulegan-Carpenter (KC) number, based on the armor block/stone size. The variation of the critical mobility number for suction as a function of d/D and KC is determined for the ranges of the parameters 0.001

  14. Bifurcation Behaviour in the Reverse-Flow Boundary Layer with Special Injection or Suction

    Institute of Scientific and Technical Information of China (English)

    ZHENG Lian-Cun; ZHANG Xin-Xin; HE Ji-Cheng

    2003-01-01

    Bifurcation solutions are numerically presented for reverse Bow boundary layer equations with special suction/injection by utilizing similarity transformation and shooting technique. The results indicate that both superior solution and inferior solution are noticeable. The skin friction and shear stress for the superior solution decrease with the increases of the ratio of surface velocity to free stream velocity and suction/injection. The behaviour is opposite to that for the inferior solution. Both the skin frictions for the superior and inferior solutions decrease with increasing the power law parameter. The inferior solution approaches the superior solution with increasing the velocity ratio and suction/injection. When power law is unit and suction/injection is zero, the superior solution approaches the classical Blasius solution as the velocity ratio approaches zero.

  15. Similarity transformation for equilibrium flows, including effects of blowing and suction

    CERN Document Server

    Chen, Xi

    2016-01-01

    A similarity transformation for the mean velocity profiles is obtained in sink flow turbulent boundary layers (TBL), including effects of blowing and suction. It is based on symmetry analysis which transforms the governing partial differential equations (for mean mass and momentum) into an ordinary differential equation and yields a new result including an exact, linear relation between the mean normal ($V$) and streamwise ($U$) velocities. A characteristic length is further introduced which, under a first order expansion in wall blowing/suction velocity, leads to the similarity transformation for $U$. This transformation is shown to be a group invariant under a generalized symmetry analysis and maps different $U$ profiles under different blowing/suction conditions into a (universal) profile under no blowing/suction. Its inverse transformation enables predictions of all mean quantities in the mean mass and momentum equations - $U$, $V$ and the Reynolds shear stress - in good agreement with direct numerical si...

  16. A parametric optimization procedure for the suction system of reciprocating compressors

    Science.gov (United States)

    Ferreira, W. M.; Silva, E.; Deschamps, C. J.

    2015-08-01

    The design of the suction system of compressors is of fundamental importance for efficiency and reliability. This paper reports a method developed to optimize the suction system of a reciprocating compressor, by using the genetic algorithm NSGA-II. The isentropic and volumetric efficiencies are used as objective functions, while the bending fatigue stress is used as a constraint to meet valve reliability. A simulation model of the compression cycle was coupled to the optimization procedure, with correlations for flow and force effective areas in terms of geometric parameters of the suction valve. Valve dynamics was numerically solved via the finite element method. The proposed optimization procedure was applied to a reciprocating compressor adopted for household refrigeration, identifying suction system geometries more efficient than the original design.

  17. Recent developments in the techniques of controlling and measuring suction in unsaturated soils

    CERN Document Server

    Delage, Pierre; Tarantino, Alessandro

    2008-01-01

    The difficulty of measuring and controlling suction in unsaturated soils is one of the reasons why the development of the mechanics of unsaturated soils has not been as advanced as that of saturated soils. However, significant developments have been carried out in the last decade in this regard. In this paper, a re-view of some developments carried out in the techniques of controlling suction by using the axis translation, the osmotic method and the vapour control technique is presented. The paper also deals with some recent de-velopments in the direct measurement of suction by using high capacity tensiometers and in the measurement of high suction by using high range psychrometers. The recent progresses made in these techniques have been significant and will certainly help further experimental investigation of the hydromechanical behaviour of un-saturated soils.

  18. Review of theModern developments in Suction processes of IC Engines

    OpenAIRE

    Dhruv Chawda; Subhajit Dey

    2014-01-01

    This review paper deals with the evolution of the general processes employed in the suction process of IC Engines. The suction process has evolved from the traditional use of carburettors to much more sophisticated systems like CRDi, MPFi, etc. used in modern days. In doing so, various parameters such as the volumetric efficiency and the turbulence, etc. inside the engine have to be considered. Additional processes such as supercharging and turbocharging are employed to improv...

  19. Secondary subharmonic instability of boundary layers with pressure gradient and suction

    Science.gov (United States)

    El-Hady, Nabil M.

    1988-01-01

    Three-dimensional linear secondary instability is investigated for boundary layers with pressure gradient and suction in the presence of a finite amplitude TS wave. The focus is on principal parametric resonance responsible for a strong growth of subharmonics in a low disturbance environment. Calculations are presented for the effect of pressure gradients and suction on controlling the onset and amplification of the secondary instability.

  20. Supermarket refrigeration. Optimization of suction pressure in existing refrigerators; Supermarktkaelte. Saugdruck optimieren in Bestandskaelteanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Philipp; Mueller, Markus [Eckelmann AG, Wiesbaden (Germany)

    2012-06-15

    The new E*LDS firmware E*COP{sup +} from Eckelmann AG (Wiesbaden, Federal Republic of Germany) for the optimization of the suction pressure supplies a demand-oriented adaptation of the suction pressure. The new feature is ideal for an update of existing systems with thermostatic expansion valves. Using this update operators of supermarket operators may save about 10% energy with little effort.

  1. VORCAM: A computer program for calculating vortex lift effect of cambered wings by the suction analogy

    Science.gov (United States)

    Lan, C. E.; Chang, J. F.

    1981-01-01

    A user's guide to an improved version of Woodward's chord plane aerodynamic panel computer code is presumed. The guide can be applied to cambered wings exhibiting edge separated flow, including those with leading edge vortex flow at subsonic and supersonic speeds. New orientations for the rotated suction force are employed based on the momentum principal. The supersonic suction analogy method is improved by using an effective angle of attack defined through a semiempirical method.

  2. Suction drain tip culture in orthopaedic surgery: a prospective study of 214 clean operations

    OpenAIRE

    Sankar, B.; P Ray; Rai, J.

    2004-01-01

    We conducted a prospective cohort study in order to determine whether suction drain specimen cultures from orthopaedic surgery predicted an early wound infection. We included 218 consecutive clean orthopaedic operations requiring drains in one unit over a period of 1 year. The suction drain tip, drain fluid and wound discharge specimens were cultured, and the surgical wound was followed up for 3 months. There were six deep and two superficial wound infections. Wound infection was significantl...

  3. The role of subgaleal suction drain placement in chronic subdural hematoma evacuation

    OpenAIRE

    Yadav, Yad Ram; Parihar, Vijay; Chourasia, Ishwar D.; Bajaj, Jitin; Namdev, Hemant

    2016-01-01

    Introduction: There is lack of uniformity about the preferred surgical treatment, role of drain, and type of drain among various surgeons in chronic subdural hematoma (CSDH). The present study is aimed to evaluate role of subgaleal drain. Materials and Methods: This was a prospective study of 260 patients of CSDH treated surgically. Burr-hole irrigation with and without suction drain was done in 140 and 120 patients, respectively. Out of 120 patients without suction drain 60 each were managed...

  4. Pain in aquatic animals.

    Science.gov (United States)

    Sneddon, Lynne U

    2015-04-01

    Recent developments in the study of pain in animals have demonstrated the potential for pain perception in a variety of wholly aquatic species such as molluscs, crustaceans and fish. This allows us to gain insight into how the ecological pressures and differential life history of living in a watery medium can yield novel data that inform the comparative physiology and evolution of pain. Nociception is the simple detection of potentially painful stimuli usually accompanied by a reflex withdrawal response, and nociceptors have been found in aquatic invertebrates such as the sea slug Aplysia. It would seem adaptive to have a warning system that allows animals to avoid life-threatening injury, yet debate does still continue over the capacity for non-mammalian species to experience the discomfort or suffering that is a key component of pain rather than a nociceptive reflex. Contemporary studies over the last 10 years have demonstrated that bony fish possess nociceptors that are similar to those in mammals; that they demonstrate pain-related changes in physiology and behaviour that are reduced by painkillers; that they exhibit higher brain activity when painfully stimulated; and that pain is more important than showing fear or anti-predator behaviour in bony fish. The neurophysiological basis of nociception or pain in fish is demonstrably similar to that in mammals. Pain perception in invertebrates is more controversial as they lack the vertebrate brain, yet recent research evidence confirms that there are behavioural changes in response to potentially painful events. This review will assess the field of pain perception in aquatic species, focusing on fish and selected invertebrate groups to interpret how research findings can inform our understanding of the physiology and evolution of pain. Further, if we accept these animals may be capable of experiencing the negative experience of pain, then the wider implications of human use of these animals should be considered.

  5. Suction characteristics of a thick material pump at high concentrations of coal slime

    Institute of Scientific and Technical Information of China (English)

    MA Xing-min; ZHAO Qiao-zhi; GAO Shao-gang; WU Miao

    2008-01-01

    A test system was designed to study the parameters affecting the volumetric efficiency of a thick-material pump for coal slime. The parameters studied included solid concentration, the slenderness ratio of the suction cylinder and the running speed of the hydraulic cylinder. In the experiment the concentrations of coal slime were 75.7%, 76.3%, 74.4%, 73.5%, 72.1% and 70.63%; the running speeds were 0.23, 0.18, 0.13, 0.10 and 0.08 m/s; and the slenderness ratios of the suction cylinder were 1.63, 2.26, 2.88, 3.50, 4.13, 4.78 and 5.38. The results show that the suction volumetric efficiency decreases gradually with an increase in material concentration. The critical concentration value is 72%; below 72% the suction volumetric efficiency is above 90%, otherwise it decreases rapidly. When the solid concentration reaches 76.3%, the suction volumetric efficiency is only 40%. When the running speed of the piston is less than or equal to 0.23 m/s, the suction volumetric efficiency increases with an increase in running speed.

  6. Conceptual Framework for Aquatic Interfaces

    Science.gov (United States)

    Lewandowski, J.; Krause, S.

    2015-12-01

    Aquatic interfaces are generally characterized by steep gradients of physical, chemical and biological properties due to the contrast between the two adjacent environments. Innovative measurement techniques are required to study the spatially heterogeneous and temporally variable processes. Especially the different spatial and temporal scales are a large challenge. Due to the steep biogeochemical gradients and the intensive structural and compositional heterogeneity, enhanced biogeochemical processing rates are inherent to aquatic interfaces. Nevertheless, the effective turnover depends strongly on the residence time distribution along the flow paths and in sections with particular biogeochemical milieus and reaction kinetics. Thus, identification and characterization of the highly complex flow patterns in and across aquatic interfaces are crucial to understand biogeochemical processing along exchange flow paths and to quantify transport across aquatic interfaces. Hydrodynamic and biogeochemical processes are closely coupled at aquatic interfaces. However, interface processing rates are not only enhanced compared to the adjacent compartments that they connect; also completely different reactions might occur if certain thresholds are exceeded or the biogeochemical milieu differs significantly from the adjacent environments. Single events, temporal variability and spatial heterogeneity might increase overall processing rates of aquatic interfaces and thus, should not be neglected when studying aquatic interfaces. Aquatic interfaces are key zones relevant for the ecological state of the entire ecosystem and thus, understanding interface functioning and controls is paramount for ecosystem management. The overall aim of this contribution is a general conceptual framework for aquatic interfaces that is applicable to a wide range of systems, scales and processes.

  7. Extreme adaptations for aquatic ectoparasitism in a Jurassic fly larva.

    Science.gov (United States)

    Chen, Jun; Wang, Bo; Engel, Michael S; Wappler, Torsten; Jarzembowski, Edmund A; Zhang, Haichun; Wang, Xiaoli; Zheng, Xiaoting; Rust, Jes

    2014-06-24

    The reconstruction of ancient insect ectoparasitism is challenging, mostly because of the extreme scarcity of fossils with obvious ectoparasitic features such as sucking-piercing mouthparts and specialized attachment organs. Here we describe a bizarre fly larva (Diptera), Qiyia jurassica gen. et sp. nov., from the Jurassic of China, that represents a stem group of the tabanomorph family Athericidae. Q. jurassica exhibits adaptations to an aquatic habitat. More importantly, it preserves an unusual combination of features including a thoracic sucker with six radial ridges, unique in insects, piercing-sucking mouthparts for fluid feeding, and crocheted ventral prolegs with upward directed bristles for anchoring and movement while submerged. We demonstrate that Q. jurassica was an aquatic ectoparasitic insect, probably feeding on the blood of salamanders. The finding reveals an extreme morphological specialization of fly larvae, and broadens our understanding of the diversity of ectoparasitism in Mesozoic insects.DOI: http://dx.doi.org/10.7554/eLife.02844.001.

  8. STUDY ON THE CHARACTERISTICS OF THE AMMONIA-NIROGEN AND RESIDUAL FEEDS DEGRADATION IN AQUATIC WATER BY BACILLUS LICHENIFORMIS%地衣芽孢杆菌对养殖水体氨氮、残饵降解特性研究

    Institute of Scientific and Technical Information of China (English)

    张庆华; 封永辉; 王娟; 郭婧; 张永华; 高建忠; 宋增福

    2011-01-01

    It is well known that ammonia-nitrogen is one of the toxic factors to affect the growth performances and increase the susceptibility of the aquatic animal in the culture ponds water.With the development of aquaculture, the intensive and high-density culture aggravate the serious pollution problem of the ammonium nitrogen; however, the traditional physical and chemical methods to remove the ammonia-nitrogen will be cut down for the secondary pollution step by step.Meanwhile, the biological methods to remove ammonia-nitrogen and bioremediation have attracted much more attentions from the scientists for the characteristics of high-efficiency, low cost, no residue and environmental friendly,which become more and more popular in the practices.The present studies were focused on the Bacillus subtitles, Bacillus cereus and Sporolactobacillus.Large yellow croaker (Pseudosciaena crocea) is one of the traditional Chinese Four Seafood that is the offshore main economic fishes, which culture widely in the China eastern offshore.In the present experiment, a Bacillus licheniformis strain X3914 as a potential probiotics was isolated from gastrointestinal tract of healthy large yellow croaker (Pseudosciaena crocea) cultured in Xiangshan, Zhejiang Province.The aim of the study is to explore the degradation rules of ammonia-nitrogen, protein and starch of residual feeds by Bacillus licheniformis strain X3914, which probably offers the guidance to the practices in aquaculture.In the present experiment, the ability to remove the ammonia-nitrogen of the Bacillus licheniformis strain X3914 was tested in the simulated waste water, the results indicated that the growth of the strain X3914 was synchronized with the degradation of ammonia-nitrogen and degradation rate of ammonia-nitrogen reached to 36.2% in 24h.Furthermore,Ammonia-nitrogen containing the ammonium ions, and ammonia molecules, as the toxicity of ammonium ions was influenced significantly by environmental factors, such as

  9. Effect of pesticides on microbial communities in container aquatic habitats

    Science.gov (United States)

    Muturi, Ephantus J.; Donthu, Ravi Kiran; Fields, Christopher J.; Moise, Imelda K.; Kim, Chang-Hyun

    2017-01-01

    Container aquatic habitats support a specialized community of macroinvertebrates (e.g. mosquitoes) that feed on microbial communities associated with decaying organic matter. These aquatic habitats are often embedded within and around agricultural lands and are frequently exposed to pesticides. We used a microcosm approach to examine the single and combined effects of two herbicides (atrazine, glyphosate), and three insecticides (malathion, carbaryl, permethrin) on microbial communities of container aquatic habitats. MiSeq sequencing of the V4 region of both bacterial and archaeal 16S rRNA gene was used to characterize the microbial communities of indoor microcosms that were either exposed to each pesticide alone, a mix of herbicides, a mix of insecticides, or a mix of all five insecticides. Individual insecticides but not herbicides reduced the microbial diversity and richness and two insecticides, carbaryl and permethrin, also altered the microbial community structure. A mixture of herbicides had no effect on microbial diversity or structure but a mixture of insecticides or all five pesticides reduced microbial diversity and altered the community structure. These findings suggest that exposure of aquatic ecosystems to individual pesticides or their mixtures can disrupt aquatic microbial communities and there is need to decipher how these changes affect resident macroinvertebrate communities. PMID:28300212

  10. Effect of pesticides on microbial communities in container aquatic habitats.

    Science.gov (United States)

    Muturi, Ephantus J; Donthu, Ravi Kiran; Fields, Christopher J; Moise, Imelda K; Kim, Chang-Hyun

    2017-03-16

    Container aquatic habitats support a specialized community of macroinvertebrates (e.g. mosquitoes) that feed on microbial communities associated with decaying organic matter. These aquatic habitats are often embedded within and around agricultural lands and are frequently exposed to pesticides. We used a microcosm approach to examine the single and combined effects of two herbicides (atrazine, glyphosate), and three insecticides (malathion, carbaryl, permethrin) on microbial communities of container aquatic habitats. MiSeq sequencing of the V4 region of both bacterial and archaeal 16S rRNA gene was used to characterize the microbial communities of indoor microcosms that were either exposed to each pesticide alone, a mix of herbicides, a mix of insecticides, or a mix of all five insecticides. Individual insecticides but not herbicides reduced the microbial diversity and richness and two insecticides, carbaryl and permethrin, also altered the microbial community structure. A mixture of herbicides had no effect on microbial diversity or structure but a mixture of insecticides or all five pesticides reduced microbial diversity and altered the community structure. These findings suggest that exposure of aquatic ecosystems to individual pesticides or their mixtures can disrupt aquatic microbial communities and there is need to decipher how these changes affect resident macroinvertebrate communities.

  11. Evaluation of suction detection during different pumping states in an implantable rotary blood pump.

    Science.gov (United States)

    Ng, Siew-Cheok; Lim, Einly; Mason, David G; Avolio, Alberto P; Lovell, Nigel H

    2013-08-01

    In recent times, the problem of noninvasive suction detection for implantable rotary blood pumps has attracted substantial research interest. Here, we compare the performance of various suction indices for different types of suction and non-suction events based on pump speed irregularity. A total of 171 different indices that consist of previously proposed as well as newly introduced suction indices are tested using regularized logistic regression. These indices can be classified as amplitude based (derived from the mean, maximum, and minimum values of a cycle), duration based (derived from the duration of a cycle), gradient based (derived from the first order as well as higher order differences) and frequency based (derived from the power spectral density). The non-suction event data consists of ventricular ejection with or without arrhythmia and intermittent and continuous non-opening of the aortic valve. The suction event data consists of partial ventricular collapse that occurs intermittently as well as continuously with or without arrhythmia. In addition, we also attempted to minimize the usage of multiple indices by applying the sequential forward floating selection method to find which combination of indices gives the best performance. In general, the amplitude-based and gradient-based indices performed quite well while the duration-based and frequency-based indices performed poorly. By having only two indices ([i] the maximum gradient change in positive slope; and [ii] the standard deviation of the maximum value in a cycle), we were able to achieve a sensitivity of 98.9% and a specificity of 99.7%.

  12. Some physiological responses of wheat and bean to soil salinity at low matric suctions

    Science.gov (United States)

    Khatar, Mahnaz; Mohammadi, Mohammad Hossein; Shekari, Farid

    2017-01-01

    The effect of soil matric suction (2-33 kPa) and salinity (soil solution electrical conductivity 0.7-8 dS m-1 for bean and 2-20 dS m-1 for wheat) on some physiological characteristics of bean and wheat in a clay loam soil under greenhouse condition was investigated. The results showed that the leaf chlorophyll content index and potassium concentration decrease under salinity stress and increase with matric suction from 2 to 33 kPa suction for both plants. The wheat chlorophyll content index declines during the stress spell but bean chlorophyll content index remains nearly constant. The lowest values of the content of soluble sugars and the highest values of leaf proline content are observed at2 kPa matric suction (highest aeration stress) for bean and wheat. As matric suction increases from 2 to 6 kPa, the soluble sugars increases and proline content decreases significantly and then soluble sugars decreases and proline content increases until 10 kPa suction, and the soluble sugars remains nearly constant at the higher matric suctions for both plants. While the electrical conductivity effect on the soluble sugars is not significant, the values of proline content for both crop increase significantly with electrical conductivity. It was shown that the aeration stress can result in more considerable and rapid physiological responses, in comparison with salinity stress. There is a strong correlation between wheat and bean chlorophyll content index and potassium concentration under salinity and aeration stresses.

  13. An analysis of quantitative measurements of drainage exudate using negative suction in 96 microtia ear reconstructions.

    Science.gov (United States)

    Xu, Zhicheng; Zhang, Ruhong; Zhang, Qun; Xu, Feng

    2012-01-01

    Negative suction drainage is commonly used for the prevention of seromas or hematomas in auricular reconstruction surgery; however, there are few reports regarding the quantitative measurement of negative suction and its relation to disposed time, patient age or microtia type. In the present study, the authors recorded the volume of suction exudate in microtia reconstruction and elaborate on the relevant details of controlling negative suction. A negative suction drainage system was applied in 96 microtia patients between 2007 and 2010. Two small polyethylene drains were inserted adjacent to the concha and the scapha, respectively. The volume of exudate was recorded for three days after surgery and was analyzed according to disposed time, patient age and microtia type. The drains were removed on the third postoperative day, when only a small amount of exudate remained. A significant change in drainage was observed over three days postoperatively, and the quantity decreased progressively on the third postoperative day. Comparison of age groups showed that the volume of drainage from adults was greater than that from children or adolescents in the first two postoperative days, regardless of whether the drains were inserted in the scapha or concha. No statistical differences were found on the third postoperative day. A comparison of drain types revealed no statistically significant differences between scapha and concha drains three days postoperatively. The analysis demonstrated that drainage quantity is related to disposed time and patient age, but not to microtia type. The authors recommend removal of suction drains on the third postoperative day. Moreover, individualized negative suction treatment according to age or microtia type provides a safe and consistent approach to achieving acceptable results and fewer complications.

  14. The aquatic habit and host plants of Paracles klagesi (Rothschild (Lepidoptera, Erebidae, Arctiinae in Brazil

    Directory of Open Access Journals (Sweden)

    Aurélio R. Meneses

    2013-09-01

    Full Text Available The aquatic habit and host plants of Paracles klagesi (Rothschild (Lepidoptera, Erebidae, Arctiinae in Brazil. The aquatic caterpillar Paracles klagesi (Rothschild, 1910 was collected from the headwaters of a stream in an ecotone between Cerrado and Babaçu forest in northeastern Brazil. The single caterpillar found was observed feeding on the macrophyte Tonina fluviatilis Aubl. (Eriocaulaceae and other aquatic plants of the family Nymphaeaceae present in the area, but also accepted as food Elodea canadensis Michx. (Hydrocharitaceae and Cabomba sp. (Cabombaceae under laboratory conditions.

  15. Assessment of vector/host contact: comparison of animal-baited traps and UV-light/suction trap for collecting Culicoides biting midges (Diptera: Ceratopogonidae, vectors of Orbiviruses

    Directory of Open Access Journals (Sweden)

    Delécolle Jean-Claude

    2011-06-01

    Full Text Available Abstract Background The emergence and massive spread of bluetongue in Western Europe during 2006-2008 had disastrous consequences for sheep and cattle production and confirmed the ability of Palaearctic Culicoides (Diptera: Ceratopogonidae to transmit the virus. Some aspects of Culicoides ecology, especially host-seeking and feeding behaviors, remain insufficiently described due to the difficulty of collecting them directly on a bait animal, the most reliable method to evaluate biting rates. Our aim was to compare typical animal-baited traps (drop trap and direct aspiration to both a new sticky cover trap and a UV-light/suction trap (the most commonly used method to collect Culicoides. Methods/results Collections were made from 1.45 hours before sunset to 1.45 hours after sunset in June/July 2009 at an experimental sheep farm (INRA, Nouzilly, Western France, with 3 replicates of a 4 sites × 4 traps randomized Latin square using one sheep per site. Collected Culicoides individuals were sorted morphologically to species, sex and physiological stages for females. Sibling species were identified using a molecular assay. A total of 534 Culicoides belonging to 17 species was collected. Abundance was maximal in the drop trap (232 females and 4 males from 10 species whereas the diversity was the highest in the UV-light/suction trap (136 females and 5 males from 15 species. Significant between-trap differences abundance and parity rates were observed. Conclusions Only the direct aspiration collected exclusively host-seeking females, despite a concern that human manipulation may influence estimation of the biting rate. The sticky cover trap assessed accurately the biting rate of abundant species even if it might act as an interception trap. The drop trap collected the highest abundance of Culicoides and may have caught individuals not attracted by sheep but by its structure. Finally, abundances obtained using the UV-light/suction trap did not estimate

  16. Screening level dose assessment of aquatic biota downstream of the Marcoule nuclear complex in southern France.

    Science.gov (United States)

    St-Pierre, S; Chambers, D B; Lowe, L M; Bontoux, J G

    1999-09-01

    Aquatic biota in the Rhone River downstream of the Marcoule nuclear complex in France are exposed to natural sources of radiation and to radioactivity released from the Marcoule complex. A simple conservative screening level model was used to estimate the range of concentrations in aquatic media (water, sediments, and aquatic organisms) of both artificial and natural radionuclides and the consequent absorbed (whole body) dose rates for aquatic organisms. Five categories of aquatic organisms were studied, namely, submerged aquatic plants (phanerogam), non-bottom-feeding fish, bottom-feeding fish, mollusca, and fish-eating birds. The analysis was based on the radionuclide concentrations reported in four consecutive annual radioecological monitoring reports published by French agencies with nuclear regulatory responsibilities. The results of this assessment were used to determine, qualitatively, the magnitude of any potential health impacts on each of the five categories of aquatic organisms studied. The range of dose rate estimates ranged over three orders of magnitude, with maximum dose rates estimated to be in the order of 1 to 10 microGy h(-1). These maximum dose rates are a factor 40 or more below the international guideline intended to ensure the protection of aquatic populations (about 400 microGy h(-1)), and a factor ten or more below the level which may trigger the need for a more detailed evaluation of potential ecological consequences to the exposed populations (about 100 microGy h(-1)). As a result, chronic levels of radioactivity, artificial and natural, measured in aquatic media downstream of Marcoule are unlikely to result in adverse health impacts on the categories and species of aquatic organisms studied. Thus, based on the screening level analysis discussed in this paper, a more detailed evaluation of the dose rates does not appear to be warranted.

  17. Hydrodynamics of Microbial Filter-Feeding

    Science.gov (United States)

    Andersen, Anders; Nielsen, Lasse Tor; Dolger, Julia; Kiorboe, Thomas

    2016-11-01

    Microbial filter-feeders form an important group of plankton with significance to the aquatic food webs. While the concept of filter-feeding is straightforward, our quantitative understanding of microbial filter-feeding leaves a lot to be desired. As a model organism, we focus on the filter-feeding choanoflagellate Diaphanoeca grandis. We quantify the feeding flow using particle tracking, and demonstrate that hydrodynamic theory underestimates the observed clearance rate by an order of magnitude. We find similar discrepancies for other choanoflagellate species, highlighting an apparent paradox. To resolve the paradox we argue that D. grandis and other choanoflagellates must have so far unbeknownst morphological features. Specifically, we suggest a flagellar vane that connects the flagellum to the filter, as known in choanocytes of sponges, creating a radically different, and order of magnitude more capable, pumping mechanism. The Centre for Ocean Life is a VKR Centre of Excellence supported by the Villum Foundation.

  18. Open and Closed Endotracheal Suctioning and Arterial Blood Gas Values: A Single-Blind Crossover Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Azam Faraji

    2015-01-01

    Full Text Available Aim. This study was aimed at comparing the effects of the open and closed suctioning techniques on the arterial blood gas values in patients undergoing open-heart surgery. Methods. In a clinical trial, we recruited 42 patients after open-heart surgery in an educational hospital. Each patient randomly underwent both open and closed suctioning. ABGs, PaO2, SaO2, PaCO2, were analyzed before and one, five, and fifteen minutes after each suctioning episode. Results. At first the pressure of oxygen in arterial blood increased; however, this increase in the open technique was greater than that of the closed system (P<0.001. The pressure of oxygen decreased five and fifteen minutes after both suctioning techniques (P<0.05. The trends of carbon dioxide variations after the open and closed techniques were upward and downward, respectively. Moreover, the decrease in the level of oxygen saturation five and fifteen minutes after the open suctioning was greater than that of the closed suctioning technique (P<0.05.  Conclusion. Arterial blood gas disturbances in the closed suctioning technique were less than those of the open technique. Therefore, to eliminate the unwanted effects of endotracheal suctioning on the arterial blood gases, the closed suctioning technique is recommended.

  19. Numerical Study of Piping Limits for Suction Installation of Offshore Skirted Foundations an Anchors in Layered Sand

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Thilsted, C. L.

    2010-01-01

    to obtain the required capacity. In order to overcome the high penetration resistance in sand suction assisted penetration is needed. Suction installation may cause the formation of piping channels, which break down the hydraulic seal and prevent further installation. This paper presents a numerical study...... of suction thresholds against piping. These closed form solutions are compared with large scale tests, performed in a natural seabed at a test site in Frederikshavn, Denmark. These solutions are also valid for penetration studies of other offshore skirted foundations and anchors using suction assisted...

  20. Numerical and Experimental Investigation of Pressure Losses at Suction of a Twin Screw Compressor

    Science.gov (United States)

    Arjeneh, M.; Kovacevic, A.; Rane, S.; Manolis, M.; Stosic, N.

    2015-08-01

    Rotary twin screw machines are used in the wide range of industrial applications and are capable of handling single and multiphase fluids as compressors, expanders and pumps. Concentration of liquid in the inlet flow can influence the performance of the machine significantly. Characteristics of the multiphase flow at the suction of a screw compressor depend on the local flow velocities and concentration. Local flow velocity measurements inside the screw compressors are difficult to obtain. However other flow properties such as local pressures are easier to attain. It is therefore useful to carry out experiments with local pressure variations in the suction which can be used to validate the 3D numerical Computational Fluid Dynamic (CFD) models that could help in studying the single and multiphase flow behaviour in screw compressors. This paper presents experimental efforts to measure the local pressure losses inside the suction plenum of the screw compressor. Pressure variations are measured at 23 locations in the suction port at various operating conditions and compared with 3D CFD model. The grid generator SCORGTM was used for generating numerical mesh of rotors. The flow calculations were carried out using commercial 3D solver ANSYS CFX. It was found that the local pressure changes predicted by the CFD model are in the good agreement with measured pressures. This validated the use of CFD for modelling of the single phase flows in suction of screw machines.

  1. Hydrodynamic Analysis of the Flow Field Induced by a Symmetrical Suction Elbow at the Pump Inlet

    Science.gov (United States)

    Muntean, S.; Bosioc, A. I.; Drăghici, I.; Anton, L. E.

    2016-11-01

    The paper investigates the hydrodynamic field generated by the symmetrical suction elbow at the pump impeller inlet. The full three-dimensional turbulent numerical investigation of the flow in the symmetrical suction elbow is performed using FLUENT then the flow non-uniformity generated by it is numerically computed. The numerical results on the annular cross section are qualitatively and quantitatively validated against LDV data. A good agreement between numerical results and experimental data is obtained on this cross section located downstream to the suction elbow and upstream to the pump impeller. The hydrodynamic flow structure with four vortices is identified plotting the vorticity field. The largest values of the vorticity magnitude are identified in the center of both vortices located behind the shaft. The vortex core location is plotted on four annular cross sections located along to the cylindrical part between the suction elbow and the pump inlet. Also, the three-dimensional distribution of the vortex core filaments is visualized and extracted. The shapes of vortex core filaments located behind the pump shaft agree well with its visualization performed on the test rig. As a result, the three-dimensional complex geometry of the suction elbow and the pump shaft are identified as the main sources of the flow non-uniformity at the pump inlet.

  2. Digital suction and family functionality in children in Health Area II. Cienfuegos.

    Directory of Open Access Journals (Sweden)

    Ana María Nápoles Quintero

    2007-12-01

    Full Text Available Bakground: Digital suction is a pernicious habit that can produce not only alterations of dental-facial's structures, but also of child's social relationships and its self-esteem. Objective: To evaluate the existent relationship between finger suction habit in children and family functionality. Method: An analytic study of cases and controls was carried out, in girls and boys of 5th and 6th levels in 8 day-care centres belonging to Area II of Cienfuegos municipality during the course 2005-2006. The studied variables were: finger suction habit, age, level, sex, and family functionality. Family functionality was perceived through the test FF-SIL. Chi square test was used to determine the relationship among the studied variables. Results: The finger suction habit prevailed in girls; functional families prevailed in the study. Most of the children with this habit come from dysfunctional families. Conclusion: Dysfunctional and severely dysfunctional families are proportionally major in the group of girls and boys with this habit, being shown the dependence between the variables finger suction and family function.

  3. Vortex lift augmentation by suction on a 60 deg swept Gothic wing

    Science.gov (United States)

    Taylor, A. H.; Jackson, L. R.; Huffman, J. K.

    1982-01-01

    An experimental investigation was conducted in the Langley high-speed 7- by 10-foot wind tunnel to determine the aerodynamic performance of suction applied near the wing tips above the trailing edge of a 60 deg swept Gothic wing. Moveable suction inlets were symmetrically mounted in the proximity of the trailing edge, and the amount of suction was varied to maximize wing lift. Tests were conducted at Mach 0.15, 0.30, and 0.45, and the angle of attack was varied from -4 to 50 deg. The suction augmentation increases the lift coefficient over the entire range of angle of attack. The lift improvement exceeds the unaugmented wing lift by over 20%. Moreover, the augmented lift exceeds the lift predicted by vortex lattice theory to 30 deg angle of attack. Suction augmentation is postulated to strengthen the vortex system by increasing its velocity and making it more concentrated. This causes the vortex breakdown to be delayed to a higher angle of attack

  4. Analysis of wound filter performance from DREF yarn spun at different suction pressure

    Directory of Open Access Journals (Sweden)

    Pragnya S. Kanade

    2017-03-01

    Full Text Available Wound filters are quite popular in the domestic water purification systems. The performance of these filters is based on the distinctive yarn and winding variables. Yarn used for filtration application is normally produced on DREF spinning system. Several researchers have reported the influence of DREF spinning variables on yarn properties. However none of them are in context of filtration application. Since elucidation of influence of winding parameters on the filter performance has already been reported; it thus becomes intriguing to explore the influence of spinning suction pressure on filtration behavior. Yarn spun at different suction pressures was used to produce wound filter cartridges, keeping winding variables unchanged. Filters wound using yarn spun at higher spinning suction pressure resulted in greater pressure drop but showed better micron rating. However the pressure drop encountered also affects the retention capacity of the wound filter. The outcome of this study helps in establishing the relation between spinning suction pressure and performance parameters of wound filters. Design expert® software was used to develop regression equations to predict performance of wound filter for the given spinning suction pressure which is of practical significance for yarn and filter manufacturers, without performing filter test.

  5. Effects of music therapy on oxygen saturation in premature infants receiving endotracheal suctioning.

    Science.gov (United States)

    Chou, Lih-Lih; Wang, Ru-Hwa; Chen, Shu-Jen; Pai, Lu

    2003-09-01

    The purpose of this study was to investigate how premature infants' oxygen saturation changed in response to music therapy while they were receiving endotracheal suctioning. A convenience sample of 30 premature infants was selected from three neonatal intensive care units. A one-group repeated measures design was adopted for this study. The oxygen saturation of all subjects was first measured while they were receiving endotracheal suctioning during a four-hour control period with regular care. Then, four hours after the control period was completed, an experimental period began in which the music " Transitions " was played. One minute before suctioning, the level of oxygen saturation was measured to provide the baseline data. During a period of 30 minutes after suctioning, the oxygen saturation was recorded every minute to analyze the clinical effects of music therapy. The results showed that premature infants receiving music therapy with endotracheal suctioning had a significantly higher SPO(2); than that when not receiving music therapy (p music therapy (p music therapy as developmental care to premature infants when performing any nursing intervention may enhance not only the quality of nursing care but also quality of the infant's life.

  6. Bio-inspired Miniature Suction Cups Actuated by Shape Memory Alloy

    Directory of Open Access Journals (Sweden)

    Hu Bing-shan

    2010-02-01

    Full Text Available Wall climbing robots using negative pressure suction always employ air pumps which have great noise and large volume. Two prototypes of bio-inspired miniature suction cup actuated by shape memory alloy (SMA are designed based on studying characteristics of biologic suction apparatuses, and the suction cups in this paper can be used as adhesion mechanisms for miniature wall climbing robots without air pumps. The first prototype with a two-way shape memory effect (TWSME extension TiNi spring imitates the piston structure of the stalked sucker; the second one actuated by a one way SMA actuator with a bias has a basic structure of stiff margin, guiding element, leader and elastic element. Analytical model of the second prototype is founded considering the constitutive model of the SMA actuator, the deflection of the thin elastic plate under compound load and the thermo-dynamic model of the sealed air cavity. Experiments are done to test their suction characteristics, and the analytical model of the second prototype is simulated on Matlab/simulink platform and validated by experiments.

  7. Feeding Your Newborn

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Feeding Your Newborn KidsHealth > For Parents > Feeding Your Newborn ... giving up the breast. previous continue About Formula Feeding Commercially prepared infant formula is a nutritious alternative ...

  8. Aquatic Invertebrate Development Working Group

    Science.gov (United States)

    Meyers, D.

    1985-01-01

    Little definitive evidence exists to show that gravity plays a major role in embyrogenesis of aquatic invertebrates. Two reasons for this may be: (1) few studies have been done that emphasize the role of gravity; and (2) there simply may not be any gravity effect. The buoyant nature of the aquatic environment could have obscured any evolutionary effect of gravity. The small size of most eggs and their apparent lack of orientation suggests reduced gravitational influence. Therefore, it is recommended that the term development, as applied to aquatic invertebrates, be loosely defined to encompass behavioral and morphological parameters for which baseline data already exist.

  9. Characterization of the developmental stages of sucking in preterm infants during bottle feeding.

    Science.gov (United States)

    Lau, C; Alagugurusamy, R; Schanler, R J; Smith, E O; Shulman, R J

    2000-07-01

    It is acknowledged that the difficulty many preterm infants have in feeding orally results from their immature sucking skills. However, little is known regarding the development of sucking in these infants. The aim of this study was to demonstrate that the bottle-feeding performance of preterm infants is positively correlated with the developmental stage of their sucking. Infants' oral-motor skills were followed longitudinally using a special nipple/bottle system which monitored the suction and expression/compression component of sucking. The maturational process was rated into five primary stages based on the presence/absence of suction and the rhythmicity of the two components of sucking, suction and expression/compression. This five-point scale was used to characterize the developmental stage of sucking of each infant. Outcomes of feeding performance consisted of overall transfer (percent total volume transferred/volume to be taken) and rate of transfer (ml/min). Assessments were conducted when infants were taking 1-2, 3-5 and 6-8 oral feedings per day. Significant positive correlations were observed between the five stages of sucking and postmenstrual age, the defined feeding outcomes, and the number of daily oral feedings. Overall transfer and rate of transfer were enhanced when infants reached the more mature stages of sucking. We have demonstrated that oral feeding performance improves as infants' sucking skills mature. In addition, we propose that the present five-point sucking scale may be used to assess the developmental stages of sucking of preterm infants. Such knowledge would facilitate the management of oral feeding in these infants.

  10. Estudo comparativo da dieta, hábitos alimentares e morfologia trófica de duas espécies simpátricas, de peixes de pequeno porte, associados à macrófitas aquáticas - DOI: 10.4025/actascibiolsci.167 Comparative study about diet, feeding habits and trophic morphology of two sympatric species of small fishes in association with aquatic macrophytes- DOI: 10.4025/actascibiolsci.167

    Directory of Open Access Journals (Sweden)

    Valdirene Esgarbossa Loureiro-Crippa

    2007-11-01

    Full Text Available Nesse estudo foram avaliados aspectos da dieta e morfologia trófica de duas espécies simpátricas, uma de Cheirodontinae e uma de Aphyocharacinae, associadas a macrofitas aquáticas, em nove lagoas isoladas da planície de inundação do alto rio Paraná, Brasil, no ano de 2001. A análise da dieta mostrou que Aphyocharax anisitsi consumiu predominantemente microcrustáceos e Serrapinnus notomelas predominantemente algas. A morfologia do trato alimentar, incluindo boca, dentes, rastros branquiais e estômago, apresentou, aparentemente, o mesmo padrão para as duas espécies. Entretanto, os dentes são mais robustos em S. notomelas. Houve interação significativa entre o comprimento padrão (F2,215 = 74,89; p1,215 = 4,72; pS. notomelas e a menor para A. anisitsi, sendo essa diferença significativa. Os dados de dieta e morfologia, analisados conjuntamente, permitem inferir que há segregação trófica entre as duas espécies examinadas. E, ainda, que a co-existência dessas espécies é favorecida pelo amplo suprimento alimentar fornecido pelas macrófitas aquáticas.In this study we analyzed the diet and trophic morphology of two species, one of Cheirodontinae and one of Aphyocharacinae, associated with aquatic macrophytes in nine isolated lagoons of the Paraná river floodplain, Brazil, during 2001. Diet showed that Aphyocharax anisitsi feed mainly on microcrustaceans and Serrapinnus notomelas feed mainly on algae. Trophic morphology, including mouth, tooth, gill rakers and stomach showed apparently the same pattern for the two species. However, teeth are the biggest and the hardest in S. notomelas. Regarding intestine length there was significant interaction between standard length (F2.215 = 74.89; p1.215 = 4.72; pS. notomelas and a smaller mean in A. anisitsi. Based on dates of diet and morphology, it is possible to conclude that there are trophic segregation between the two species. Thus, the co-existence of these species is possible in

  11. Closed versus open endotracheal suctioning in preterm infants: effects on cerebral oxygenation and blood volume.

    Science.gov (United States)

    Mosca, F A; Colnaghi, M; Lattanzio, M; Bray, M; Pugliese, S; Fumagalli, M

    1997-01-01

    The aim of our study was to compare, using near-infrared spectroscopy (NIRS), the effects on cerebral intracellular oxygenation and cerebral blood volume (CBV) of closed endotracheal suctioning (CS), which permits continuous ventilation of the patient, with open endotracheal suctioning (OS), which requires disconnection from the ventilator. Eleven preterm infants were studied. Each patient underwent one CS, followed, after 60 min, by one OS, or vice versa, three times during the same day. Modifications in CBV and oxidized cytochrome oxidase (CytO2) were continuously detected by NIRS; arterial oxygen saturation (SaO2) heart rate (HR), transcutaneous carbon dioxide tension and mean arterial blood pressure were simultaneously recorded. Significant reductions in HR and SaO2 were observed following OS; the magnitude and duration of these negative effects of suctioning were significantly reduced with CS. In addition, the decrease in CBV was more pronounced than following CS. No changes in CytO2 concentration were seen.

  12. Functional morphology of suction discs and attachment performance of the Mediterranean medicinal leech (Hirudo verbana Carena).

    Science.gov (United States)

    Kampowski, Tim; Eberhard, Laura; Gallenmüller, Friederike; Speck, Thomas; Poppinga, Simon

    2016-04-01

    Medicinal leeches use their suction discs for locomotion, adhesion to the host and, in the case of the anterior disc, also for blood ingestion. The biomechanics of their suction-based adhesion systems has been little understood until now. We investigated the functional morphology of the anterior and posterior suckers ofH irudo verbena by using light and scanning electron microscopy. Furthermore, we analysed the adhesion qualitatively and quantitatively by conducting behavioural and mechanical experiments. Our high-speed video analyses provide new insights into the attachment and detachment processes and we present a detailed description of the leech locomotion cycle. Pull-off force measurements of the anterior and posterior suction organs on seven different substrates under both aerial and water-submersed conditions reveal a significant influence of the surrounding medium, the substrate surface roughness and the tested organ on attachment forces and tenacities.

  13. Radiation Effect on Mhd Heat and Mass Transfer Flow over a Shrinking Sheet with Mass Suction

    Directory of Open Access Journals (Sweden)

    patkar ramesh

    2014-01-01

    Full Text Available A numerical analysis has been carried out to study the effects radiation and heat source/sink on the steady two dimensional magnetohydrodynamic (MHD boundary layer flow of heat and mass transfer past a shrinking sheet with wall mass suction. In the dynamic system, a uniform magnetic field acts normal to the plane of flow. The governing partial differential equations are transformed into self-similar equations are solved by employing finite difference using the quasilinearization technique. From the analysis it is found that the velocity inside the boundary layer increases with increase of wall mass suction and magnetic field and accordingly the thickness of the momentum boundary layer decreases. The temperature decreases with Hartmann number, Prandtl number, and heat sink parameter and the temperature increases with heat source parameter, radiation parameter. The concentration decreases with an increase of Hartmann number, mass suction parameter, Schmidt number, chemical reaction parameter.

  14. On the dynamic suction pumping of blood cells in tubular hearts

    CERN Document Server

    Battista, Nicholas A; Miller, Laura A

    2016-01-01

    Around the third week after gestation in embryonic development, the human heart consists only of a valvless tube, unlike a fully developed adult heart, which is multi-chambered. At this stage in development, the heart valves have not formed and so net flow of blood through the heart must be driven by a different mechanism. It is hypothesized that there are two possible mechanisms that drive blood flow at this stage - Liebau pumping (dynamic suction pumping or valveless pumping) and peristaltic pumping. We implement the immersed boundary method with adaptive mesh refinement (IBAMR) to numerically study the effect of hematocrit on the circulation around a valveless. Both peristalsis and dynamic suction pumping are considered. In the case of dynamic suction pumping, the heart and circulatory system is simplified as a flexible tube attached to a relatively rigid racetrack. For some Womersley number (Wo) regimes, there is significant net flow around the racetrack. We find that the addition of flexible blood cells ...

  15. Tunison Laboratory of Aquatic Science

    Data.gov (United States)

    Federal Laboratory Consortium — Tunison Laboratory of Aquatic Science (TLAS), located in Cortland, New York, is a field station of the USGS Great Lakes Science Center (GLSC). TLAS was established...

  16. Production in aquatic macrophyte communities

    DEFF Research Database (Denmark)

    Binzer, Thomas; Sand-Jensen, Kaj

    2002-01-01

    Many terrestrial plant canopies regulate spatial patterns in leaf density and leaf inclination to distribute light evenly between the photosynthetic tissue and to optimize light utilization efficiency. Sessile aquatic macrophytes, however, cannot maintain the same well-defined three......-dimensional structure because of the strong drag and shear forces of moving water. This difference in canopy structure has been suggested to account for the three- to fivefold higher gross production rates in terrestrial than aquatic communities. To evaluate the effect of community structure in aquatic habitats, we...... was markedly enhanced by a vertical orientation of thalli when absorptance and community density were both high. This result implies that aquatic macrophytes of high thallus absorptance and community density exposed to high light are limited in attaining high gross production rates because of their inability...

  17. Aquatic Remediation of Communication Disorders.

    Science.gov (United States)

    Smith, Virginia M.

    1985-01-01

    A 10-day aquatics program for learning disabled children with hand-eye coordination problems and low self-esteem is described. Activities for each session (including relaxation exercises) are listed. (CL)

  18. Mechanical Design and Research on Process of Air Suction Drawing System of Spunbonded Nonwoven

    Institute of Scientific and Technical Information of China (English)

    WANG Hong; JIN Xiang-yu; WU Hai-bo; YIN Bao-pu; TANG Shou-xin

    2008-01-01

    The design guideline for the air suction drawing system with auxiliary air was analyzed, a spunbonding nonwoven system named PADHL1-3200 was designed and polypropylene (PP) spunbonded nonwoven fabrics with excellent properties were achieved after many trial runs. On the other hand, the suction air velocity (VA) was calculated and the influence of VA on the bonding strengh of PP nonwoven fabrics was studied as well. It was found that VA is 1.5-2.5 times of the spinning velocity. With the increase of VA, PP fibers become finer and the bonding strength of PP nonwoven fabrics increases as well.

  19. Can pharmacologic hyperprolactinemia and breast-suction induce lactation in women with normal menstrual cycles?

    Science.gov (United States)

    Polatti, F; Brambilla, A; Mandelli, B; Forgione, A

    1984-01-01

    Six women--age range 21/24--with regular ovulatory cycles, voluntarily underwent with L-Sulpiride (100 mg/die) from the 5th to the 19th day of the cycle. On the 13th, 14th and 15th day of therapy breast suction by syringe breast-pump was performed on each woman every 6 hours and for 4' from either breast. Milk secretion was poor and showed no noticeable increase in the three days of breast suction. L-Sulpiride-induced hyperprolactinemia combined with nipple stimulation-induced increased PRL secretion failed to stimulate milk secretion at a level comparable with physiologic lactation in puerperium.

  20. The influence of total suction on the brittle failure characteristics of clay shales

    Science.gov (United States)

    Amann, F.; Linda, W.; Zimmer, S.; Thoeny, R.

    2013-12-01

    Clay shale testing is challenging and the results obtained from standard laboratory tests may not always reflect the strength of the clay shale in-situ. This is to a certain extend associated with the sensitivity of these rock types to desaturation processes during drilling, sample storage, and sample preparation. In this study the relationship between total suction, uniaxial compressive strength and Brazilian tensile (BTS) strength of cylindrical samples of Opalinus Clay was established in a systematic manner. Unconfined uniaxial compression and BTS tests were performed utilizing a servo-controlled testing procedure. Total suctions in the specimens was generated in air tight desiccators using supersaturated saline solutions which establish a relative humidity ranging from 20% to 99%. For unconfined compressive strength tests loading of the specimens occurred parallel to bedding. For BTS tests loading was either oriented normal or perpendicular to bedding. Both, the crack initiation and volumetric strain reversal threshold values were determined using volumetric and radial stress-strain methods. The results of BTS tests show that the tensile strength normal and perpendicular to bedding increases by a factor of approximately 3 when total suction is increased from 0 to 90 MPa (i.e. saturation decreases from 1.0 to 0.7) . Beyond 90 MPa total suction no further increase in tensile strength was observed, most probably due to shrinkage cracks which alter the tensile strength of the clay shale. Results obtained from UCS tests suggest that higher total suctions result in higher UCS values. Between total suctions of 0 to 90 MPa, the strength increase is almost linear (i.e. the UCS increases by a factor of 1.5 MPa). Beyond 90 MPa total suction no further strength increase was observed. A similar trend can be observed for crack initiation and crack damage values. In the same range of total suction the crack initiation stress increases by a factor of 5 (from 2 MPa to 10 MPa

  1. External suction versus water seal after selective pulmonary resection for lung neoplasm: a systematic review.

    Directory of Open Access Journals (Sweden)

    Tong Qiu

    Full Text Available OBJECTIVE: To evaluate whether external suction is more advantageous than water seal in patients undergoing selective pulmonary resection (SPR for lung neoplasm. SUMMARY OF BACKGROUND DATA: Whether external suction should be routinely applied in postoperative chest drainage is still unclear, particularly for lung neoplasm patients. To most surgeons, the decision is based on their clinical experience. METHODS: Randomized control trials were selected. The participants were patients undergoing SPR with lung neoplasm. Lung volume reduction surgery and pneumothorax were excluded. Suction versus non-suction for the intervention. The primary outcome was the incidence of persistent air leak (PAL. The definition of PAL was air leak for more than 3-7 days. The secondary outcomes included air leak duration, time of drainage, postoperative hospital stay and the incidence of postoperative pneumothorax. Studies were identified from literature collections through screening. Bias was analyzed and meta-analysis was used. RESULTS: From the 1824 potentially relevant trials, 6 randomized control trials involving 676 patients were included. There was no difference between external suction and water seal in decreasing the incidence of PAL [95% confidence interval (CI 0.81-2.16; z = 1.10; P = 0.27]. Regarding secondary outcomes, there were no differences in time of drainage (95% CI-0.36-1.56, P = 0.22, postoperative hospital stay (95% CI -.31-.54, P = 0.87 or incidence of postoperative pneumothorax (95% CI 0.18-.02, P = 0.05 between external suction and water seal. CONCLUSIONS: For participants, no differences are identified in terms of PAL incidence, drainage time, length of postoperative hospital stay or incidence of postoperative pneumothorax between external suction and water seal. The bias analysis should be emphasized. To the limitations of the bias and methodological differences among the included studies, we have no recommendation on

  2. Closed suction drainage using Lichtenstein technique in preventing wound complications following inguinal hernioplasty: brief report

    Directory of Open Access Journals (Sweden)

    Hamid Reza Hemmati

    2015-03-01

    Results: No adverse event including hematoma, seroma or wound infection occurred in either group with or without closed suction drainage in the first 10 days after surgery. Only one patient carried wound infection during days 10 to 15 following operation who was in the group with closed drainage (P=1.00. Conclusion: In this study, Seroma and hematoma was not observed in patients with and without closed suction drainage. To avoid drains' complications, indiscriminate use of antibiotics, prolonged hospital stay, we do not recommend the use of drains in this type of surgery.

  3. Aquatic Plants Aid Sewage Filter

    Science.gov (United States)

    Wolverton, B. C.

    1985-01-01

    Method of wastewater treatment combines micro-organisms and aquatic plant roots in filter bed. Treatment occurs as liquid flows up through system. Micro-organisms, attached themselves to rocky base material of filter, act in several steps to decompose organic matter in wastewater. Vascular aquatic plants (typically, reeds, rushes, cattails, or water hyacinths) absorb nitrogen, phosphorus, other nutrients, and heavy metals from water through finely divided roots.

  4. A Study on Suction-rainfall Response of a Cut Slope in Unsaturated Residual Soil Using a Field Rain Simulator

    Directory of Open Access Journals (Sweden)

    Bujang B.K. Huat

    2005-01-01

    Full Text Available This research describes the design and construction of an artificial rain simulator system and the results obtained with regards to suction-rainfall response of a cut slope in unsaturated residual soil of weathered sandstone of various weathering grades. From the field measurements, the shallow tensiometers are found to record an immediate initial increase in matric suction within the first 20 min of the simulated rain before a gradual drop in suction takes place. However no such initial spikes in suction readings were recorded by the deeper tensiometers. With constant rainfall for the next 130 min, a clear drop in soil suction was observed in all cases illustrating the effect of net infiltration process. Positive pore water pressure was even recorded by some of the deeper tensiometers. The suction recorded by the shallow tensiometers was always higher than those of the deeper tensiometers, indicating a reduction in suction with depth below the ground surface. In term of weathering grades, residual soil of weathered sandstone of weathering grade III has the highest infiltration rate indicating the more porous nature of this soil material. Like wise there is a steeper drop in suction during the rain at the said location.

  5. CFD SIMULATION OF 3D FLOW IN LARGE-BORE AXIAL-FLOW PUMP WITH HALF-ELBOW SUCTION SUMP

    Institute of Scientific and Technical Information of China (English)

    WANG Fu-jun; LI Yao-jun; CONG Guo-hui; WANG Wen-e; WANG Hai-song

    2006-01-01

    Numerical simulations of 3D turbulent flow in a large-bore axial-flow pump coupled with half-elbow suction sump were performed by using CFD approach. The numerical model and velocity and pressure distributions in entire flow passage were presented. The obvious backflow in half-elbow suction sump and strong flow nonuniformity at suction sump outlet were observed, whereas these phenomena were not observed in existing studies performed for a separate suction sump by either experimental or numerical approach. This result indicates that the interaction between half-elbow suction sump and impeller has significant effect on the flow distribution in the pump passage. The change of pump efficiency caused by the interaction was discussed.

  6. More than Meets the Eye: Functionally Salient Changes in Internal Bone Architecture Accompany Divergence in Cichlid Feeding Mode

    Directory of Open Access Journals (Sweden)

    R. Craig Albertson

    2012-01-01

    Full Text Available African cichlids have undergone extensive and repeated adaptive radiations in foraging habitat. While the external morphology of the cichlid craniofacial skeleton has been studied extensively, biomechanically relevant changes to internal bone architecture have been largely overlooked. Here we explore two fundamental questions: (1 Do changes in the internal architecture of bone accompany shifts in foraging mode? (2 What is the genetic basis for this trait? We focus on the maxilla, which is an integral part of the feeding apparatus and an element that should be subjected to significant bending forces during biting. Analyses of μCT scans revealed clear differences between the maxilla of two species that employ alternative foraging strategies (i.e., biting versus suction feeding. Hybrids between the two species exhibit maxillary geometries that closely resemble those of the suction feeding species, consistent with a dominant mode of inheritance. This was supported by the results of a genetic mapping experiment, where suction feeding alleles were dominant to biting alleles at two loci that affect bone architecture. Overall, these data suggest that the internal structure of the cichlid maxilla has a tractable genetic basis and that discrete shifts in this trait have accompanied the evolution of alternate feeding modes.

  7. Mechanics of sucking: comparison between bottle feeding and breastfeeding

    Directory of Open Access Journals (Sweden)

    Ustrell Josep M

    2010-02-01

    Full Text Available Abstract Background There is very little evidence of the similarity of the mechanics of maternal and bottle feeding. We assessed the mechanics of sucking in exclusive breastfeeding, exclusive bottle feeding, and mixed feeding. The hypothesis established was that physiological pattern for suckling movements differ depending on the type of feeding. According to this hypothesis, babies with breastfeeding have suckling movements at the breast that are different from the movements of suckling a teat of babies fed with bottle. Children with mixed feeding mix both types of suckling movements. Methods Cross-sectional study of infants aged 21-28 days with only maternal feeding or bottle feeding (234 mother-infant pairs, and a randomized open cross-over field trial in newborns aged 21-28 days and babies aged 3-5 months with mixed feeding (125 mother-infant pairs. Primary outcome measures were sucks and pauses. Results Infants aged 21-28 days exclusively bottle-fed showed fewer sucks and the same number of pauses but of longer duration compared to breastfeeding. In mixed feeding, bottle feeding compared to breastfeeding showed the same number of sucks but fewer and shorter pauses, both at 21-28 days and at 3-5 months. The mean number of breastfeedings in a day (in the mixed feed group was 5.83 ± 1.93 at 21-28 days and 4.42 ± 1.67 at 3-5 months. In the equivalence analysis of the mixed feed group, the 95% confidence interval for bottle feeding/breastfeeding ratio laid outside the range of equivalence, indicating 5.9-8.7% fewer suction movements, and fewer pauses, and shorter duration of them in bottle feeding compared with breastfeeding. Conclusions The mechanics of sucking in mixed feeding lay outside the range of equivalence comparing bottle feeding with breastfeeding, although differences were small. Children with mixed feeding would mix both types of sucking movements (breastfeeding and bottle feeding during the learning stage and adopt their own

  8. Particle-capture mechanisms in suspension-feeding invertebrates

    DEFF Research Database (Denmark)

    Riisgård, Hans Ulrik; Larsen, Poul Scheel

    2010-01-01

    A large number of suspension-feeding animals (e.g. bivalves, polychaetes, ascidians, bryozoans, crustaceans, sponges, echinoderms, cnidarians) have specialized in grazing on not only the 2 to 200 µm phytoplankton but frequently also the 0.5 to 2 µm free-living bacteria in the aquatic environment...

  9. Numerical-perturbation technique for stability of flat-plate boundary layers with suction

    Science.gov (United States)

    Reed, H. L.; Nayfeh, A. H.

    1986-01-01

    A numerical-perturbation scheme is proposed for determining the stability of flows over plates with suction through a finite number of porous suction strips. The basic flow is calculated as the sum of the Blasius flow and closed-form linearized triple-deck solutions of the flow due to the strips. A perturbation technique is used to determine the increment a(ij) in the complex wavenumber at a given location x(j) due to the presence of a strip centered at x(i). The end result is a set of influence coefficients that can be used to determine the growth rates and amplification factors for any suction levels without repeating the calculations. The numerical-perturbation results are verified by comparison with interacting boundary layers for the case of six strips and the experimental data of Reynolds and Saric for single- and multiple-strip configurations. The influence coefficient form of the solution suggests a scheme for optimizing the strip configuration. The results show that one should concentrate the suction near branch I of the neutral stability curve, a conclusion verified by the experiments.

  10. Beneficial effects of intermittent suction and pressure treatment in intermittent claudication

    DEFF Research Database (Denmark)

    Mehlsen, J; Himmelstrup, H; Himmelstrup, Bodil;

    1993-01-01

    The present study reports on the effects of a physical treatment modality in patients with intermittent claudication. During this treatment a major part of the skin surface is subjected to intermittent suction and pressure. In a previous, preliminary study the authors found a beneficial effect of...

  11. Comparison of numerical formulations for the modeling of tensile loaded suction buckets

    DEFF Research Database (Denmark)

    Sørensen, Emil Smed; Clausen, Johan Christian; Damkilde, Lars

    2017-01-01

    The tensile resistance of a suction bucket is investigated using three different numerical formulations. The first formulation utilizes the three-field u-p-U formulation accounting for solid and fluid displacements, u and U, as well as the pore-fluid pressure, p. The two other formulations compri...

  12. Experimental observation of gravity-capillary solitary waves generated by a moving air-suction

    Science.gov (United States)

    Park, Beomchan; Cho, Yeunwoo

    2016-11-01

    Gravity-capillary solitary waves are generated by a moving "air-suction" forcing instead of a moving "air-blowing" forcing. The air-suction forcing moves horizontally over the surface of deep water with speeds close to the minimum linear phase speed cmin = 23 cm/s. Three different states are observed according to forcing speed below cmin. At relatively low speeds below cmin, small-amplitude linear circular depressions are observed, and they move steadily ahead of and along with the moving forcing. As the forcing speed increases close to cmin, however, nonlinear 3-D gravity-capillary solitary waves are observed, and they move steadily ahead of and along with the moving forcing. Finally, when the forcing speed is very close to cmin, oblique shedding phenomena of 3-D gravity-capillary solitary waves are observed ahead of the moving forcing. We found that all the linear and nonlinear wave patterns generated by the air-suction forcing correspond to those generated by the air-blowing forcing. The main difference is that 3-D gravity-capillary solitary waves are observed "ahead of" the air-suction forcing, whereas the same waves are observed "behind" the air-blowing forcing. This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2014R1A1A1002441).

  13. Hirschsprung’s disease: Role of rectal suction biopsy - data on 216 specimens

    Science.gov (United States)

    Rahman, Zillur; Hannan, Jafrul; Islam, Saiful

    2010-01-01

    Background: The diagnosis of Hirschsprung’s disease (HD) is dependent on the histological study of rectal ganglion cells, and an open rectal biopsy was the mainstay that required general anaesthesia (GA) and carried risk of postoperative rectal bleeding. Suction rectal biopsy later gained wide acceptance and became the choice as there is no requirement of GA and virtual absence of any complications. Materials and Methods: A retrospective review of the histological findings of 216 rectal suction biopsies studied from 2005 to 2009. Results: There were 143 male and 73 female children. 196 (90.7%) children were within 1 year of age. Among 216 rectal suction biopsies 181 (83.80%) were aganglionic, 27 (12.5%) were ganglionic and 8 (3.7%) were inadequate. Majority of patients were of less than 1 year of age (94.47%). Conclusions: The rectal suction biopsy is a bed side procedure, safe, cheap and time saving. There is high degree of accuracy, simplicity and absence of complications. PMID:20975783

  14. Hirschsprung′s disease: Role of rectal suction biopsy - data on 216 specimens

    Directory of Open Access Journals (Sweden)

    Rahman Zillur

    2010-01-01

    Full Text Available Background: The diagnosis of Hirschsprung′s disease (HD is dependent on the histological study of rectal ganglion cells, and an open rectal biopsy was the mainstay that required general anaesthesia (GA and carried risk of postoperative rectal bleeding. Suction rectal biopsy later gained wide acceptance and became the choice as there is no requirement of GA and virtual absence of any complications. Materials and Methods: A retrospective review of the histological findings of 216 rectal suction biopsies studied from 2005 to 2009. Results: There were 143 male and 73 female children. 196 (90.7% children were within 1 year of age. Among 216 rectal suction biopsies 181 (83.80% were aganglionic, 27 (12.5% were ganglionic and 8 (3.7% were inadequate. Majority of patients were of less than 1 year of age (94.47%. Conclusions : The rectal suction biopsy is a bed side procedure, safe, cheap and time saving. There is high degree of accuracy, simplicity and absence of complications.

  15. Modeling of Filling and Solidification Process for TiAl Exhaust Valves During Suction Casting

    Institute of Scientific and Technical Information of China (English)

    Chao XIONG; Yingche MA; Bo CHEN; Kui LIU; Yiyi LI

    2013-01-01

    Investment and suction casting (ISC) represents an economic and promising process route to fabricate automotive exhaust valves ofγ-TiAl based alloys,but information available on the metal flow and the temperature changes during mould filling and solidification process for the ISC process is meager.A sequentially coupled mathematical flow-thermal model,based on the commercial finite-volume/finite-difference code FLOW-3D and the finite-element code PROCAST,has been developed to investigate the ISC process.In term of calculating the flow and temperature fields during the filling and solidification stages,potential defects including the gas bubbles and the surface air entrainment occurred in the mould filling process and the shrinkage porosities formed in the solidification process are predicted and the reasons for the formation of these defects are also analyzed.The effects of filling pressure difference control methods and moulds on gas bubble and surface air entrainment behavior are presented.It is found that by changing the filling pressure difference control methods from general suction casting to "air leakage" suction casting and reducing air leakage flow rates,the gas bubbles are eliminated effectively,and the surface air entrainment attenuate dramatically.With resort to a mould with a tetragonal runner,the surface air entrainment decrease to the lowest level.Finally,the water analogue and suction casting experiments of exhaust valves are implemented for further validation of the simulation results.

  16. Influence of saturation degree and role of suction in unsaturated soils behaviour: application to liquefaction

    Directory of Open Access Journals (Sweden)

    Vernay Mathilde

    2016-01-01

    Full Text Available The effect of the pore fluid compressibility on liquefaction has been studied by various authors. But few papers have been published about the role of suction in cyclic behavior of unsaturated soils. Most of these works use Skempton coefficient B as a reference in terms of saturation degree to analyze their results. The use of B in experimental conditions is convenient, but is not accurate when studying liquefaction behavior, since effects of suction are neglected. In this paper, the influence of saturation degree on mechanical behavior of a soil under dynamic loads is studied. Cyclic undrained triaxial tests were performed on sand samples, under various levels of saturation. Soil-water characteristic curve was used, in order to study influence of suction. The first results confirm that when the degree of saturation decreases, the resistance increases. Initial positive suction tends to stiffen the soil. It also appears that the presence of air delays the occurrence of liquefaction, but doesn’t prevent it. Indeed, liquefaction is observed, whether the soil is saturated or not.

  17. Effect of suction-dependent soil deformability on landslide susceptibility maps

    Science.gov (United States)

    Lizarraga, Jose J.; Buscarnera, Giuseppe; Frattini, Paolo; Crosta, Giovanni B.

    2016-04-01

    This contribution presents a physically-based, spatially-distributed model for shallow landslides promoted by rainfall infiltration. The model features a set of Factor of Safety values aimed to capture different failure mechanisms, namely frictional slips with limited mobility and flowslide events associated with the liquefaction of the considered soils. Indices of failure associated with these two modes of instability have been derived from unsaturated soil stability principles. In particular, the propensity to wetting-induced collapse of unsaturated soils is quantified through the introduction of a rigid-plastic model with suction-dependent yielding and strength properties. The model is combined with an analytical approach (TRIGRS) to track the spatio-temporal evolution of soil suction in slopes subjected to transient infiltration. The model has been tested to reply the triggering of shallow landslides in pyroclastic deposits in Sarno (1998, Campania Region, Southern Italy). It is shown that suction-dependent mechanical properties, such as soil deformability, have important effects on the predicted landslide susceptibility scenarios, resulting on computed unstable zones that may encompass a wide range of slope inclinations, saturation levels, and depths. Such preliminary results suggest that the proposed methodology offers an alternative mechanistic interpretation to the variability in behavior of rainfall-induced landslides. Differently to standard methods the explanation to this variability is based on suction-dependent soil behavior characteristics.

  18. Long term effects of cyclic loading on suction caisson foundations in sand

    NARCIS (Netherlands)

    Lupea, C.; Thijssen, R.; Van Tol, A.F.

    2014-01-01

    Offshore wind turbine projects have been characterised by an increase in costs, sizes and distances from shore, EWEA 2012 This created a need of investigating the adequacy of alternative and more fìnancially attractive foundation types such as suction caissons. Within a multi-footing configuration,

  19. EFFECT OF SUCTION PIPE DIAMETER AND SUBMERGENCE RATIO ON AIR LIFT PUMPING RATE

    Directory of Open Access Journals (Sweden)

    Salam J. AlMaliky

    2013-05-01

    Full Text Available The increasingly importance for the uses of the air lift pump in widespread list of fields (mining, nuclear industries, agricultural uses, petroleum industries...etc. makes it very interested for the researchers to find tools to raise the performance outcome of such pumps.An air lift pump system is setup to study the effect of the suction pipe diameter and submergence ratio on the liquid (water pumping rate. The system has a lift pipe of (0.021 m diameter and (1.25 m length. Five diameters for the suction pipe (0.021, 0.027, 0.033, 0.048 and 0.063 m with  a fixed length of (0.3 m, are tested for each of the submergence ratios (0.2, 0.3, 0.4, 0.5 respectively.        Results indicate that the higher the diameter of suction pipe is the higher the pumping rate for a fixed submergence ratio. From another side, the higher the submergence ratio is the higher the pumping rate for a fixed suction pipe diameter. Also, under high submergence ratios, high pumping rates are achieved by the use of lower air flow rates compared with those used with lower submergence ratios. The experimental results show good compatibility with the model suggested by Stenning and Martin for the performance of an air lift pump.

  20. The use of the Mini-Flap wound suction drain in maxillofacial surgery.

    OpenAIRE

    Nasser, N. A.

    1986-01-01

    Preliminary experience using the Mini-Flap closed suction drain after maxillofacial surgery is described. The drain fulfils many of the criteria required for drainage of small wounds about the face and neck, and is associated with a low incidence of postoperative haematoma, oozing and infection.

  1. Present knowledge about Laboratory Testing of Axial Loading on Suction Caissons

    DEFF Research Database (Denmark)

    Manzotti, E.; Vaitkunaite, Evelina; Ibsen, Lars Bo

    on the structure is resisted by push-pull loads on the vertical axis of each suction caisson. Relevant works where this situation is examined by means of laboratory testing are summarized in this article, then different conclusions are followed by discussion and comparison. In the initial theoretical section...

  2. Bacteremia during adenoidectomy: a comparison of suction diathermy adenoid ablation and adenoid curettage.

    LENUS (Irish Health Repository)

    Casserly, Paula

    2010-08-01

    Transient bacteremia is induced by adenoidectomy when the integrity of the nasopharyngeal membrane is broken. The aim of this study was to determine the incidence of bacteremia in patients undergoing adenoidectomy, to identify the causative organisms, and to compare the incidences of bacteremia between the two techniques suction diathermy and curettage.

  3. Can aquatic worms enhance methane production from waste activated sludge?

    Science.gov (United States)

    Serrano, Antonio; Hendrickx, Tim L G; Elissen, Hellen H J; Laarhoven, Bob; Buisman, Cees J N; Temmink, Hardy

    2016-07-01

    Although literature suggests that aquatic worms can help to enhance the methane production from excess activated sludge, clear evidence for this is missing. Therefore, anaerobic digestion tests were performed at 20 and at 30°C with sludge from a high-loaded membrane bioreactor, the aquatic worm Lumbriculus variegatus, feces from these worms and with mixtures of these substrates. A significant synergistic effect of the worms or their feces on methane production from the high-loaded sludge or on its digestion rate was not observed. However, a positive effect on low-loaded activated sludge, which generally has a lower anaerobic biodegradability, cannot be excluded. The results furthermore showed that the high-loaded sludge provides an excellent feed for L. variegatus, which is promising for concepts where worm biomass is considered a resource for technical grade products such as coatings and glues.

  4. Tritium in the aquatic environment

    Energy Technology Data Exchange (ETDEWEB)

    Blaylock, B.G.; Hoffman, F.O.; Frank, M.L.

    1986-02-01

    Tritium is of environmental importance because it is released from nuclear facilities in relatively large quantities and because it has a half life of 12.26 y. Most of the tritium released into the atmosphere eventually reaches the aqueous environment, where it is rapidly taken up by aquatic organisms. This paper reviews the current literature on tritium in the aquatic environment. Conclusions from the review, which covered studies of algae, aquatic macrophytes, invertebrates, fish, and the food chain, were that aquatic organisms incorporate tritium into their tissue-free water very rapidly and reach concentrations near those of the external medium. The rate at which tritium from tritiated water is incorporated into the organic matter of cells is slower than the rate of its incorporation into the tissue-free water. If organisms consume tritiated food, incorporation of tritium into the organic matter is faster, and a higher tritium concentration is reached than when the organisms are exposed to only tritiated water alone. Incorporation of tritium bound to molecules into the organic matter depends on the chemical form of the ''carrier'' molecule. No evidence was found that biomagnification of tritium occurs at higher trophic levels. Radiation doses from tritium releases to large populations of humans will most likely come from the consumption of contaminated water rather than contaminated aquatic food products.

  5. Aquatic plants for removal of mevinphos from the aquatic environment

    Science.gov (United States)

    Wolverton, B. C.

    1975-01-01

    Fragrant waterlily (Nymphaea odorata, Ait.), joint-grass (Paspalum distichum L.), and rush (Juncus repens, Michx.) were used to evaluate the effectiveness of vascular aquatic plants in removing the insecticide mevinphos (dimethyl-1-carbomethoxy-1propen-2-yl phosphate) from waters contaminated with this chemical. The emersed aquatic plants fragrant waterlily and joint-grass removed 87 and 93 ppm of mevinphos from water test systems in less than 2 weeks without apparent damage to the plants; whereas rush, a submersed plant, removed less insecticide than the water-soil controls. Water-soil control still contained toxic levels of this insecticide, as demonstrated by fish bioassay studies, after 35 days.

  6. The effects of suction and pin/lock suspension systems on transtibial amputees' gait performance.

    Directory of Open Access Journals (Sweden)

    Hossein Gholizadeh

    Full Text Available BACKGROUND: The suction sockets that are commonly prescribed for transtibial amputees are believed to provide a better suspension than the pin/lock systems. Nevertheless, their effect on amputees' gait performance has not yet been fully investigated. The main intention of this study was to understand the potential effects of the Seal-in (suction and the Dermo (pin/lock suspension systems on amputees' gait performance. METHODOLOGY/PRINCIPAL FINDINGS: Ten unilateral transtibial amputees participated in this prospective study, and two prostheses were fabricated for each of them. A three-dimensional motion analysis system was used to evaluate the temporal-spatial, kinematics and kinetics variables during normal walking. We also asked the participants to complete some part of Prosthesis Evaluation Questionnaire (PEQ regarding their satisfaction and problems with both systems. The results revealed that there was more symmetry in temporal-spatial parameters between the prosthetic and sound limbs using the suction system. However, the difference between two systems was not significant (p<0.05. Evaluation of kinetic data and the subjects' feedback showed that the participants had more confidence using the suction socket and the sockets were more fit for walking. Nevertheless, the participants had more complaints with this system due to the difficulty in donning and doffing. CONCLUSION: It can be concluded that even though the suction socket could create better suspension, fit, and gait performance, overall satisfaction was higher with the pin/lock system due to easy donning and doffing of the prosthesis. TRIAL REGISTRATION: irct.ir IRCT2014012816395N1.

  7. Feeding tube insertion - gastrostomy

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002937.htm Feeding tube insertion - gastrostomy To use the sharing features on this page, please enable JavaScript. A gastrostomy feeding tube insertion is the placement of a feeding ...

  8. Breastfeeding vs. Formula Feeding

    Science.gov (United States)

    ... 1- to 2-Year-Old Breastfeeding vs. Formula Feeding KidsHealth > For Parents > Breastfeeding vs. Formula Feeding Print ... a lactation specialist. previous continue All About Formula Feeding Commercially prepared infant formulas are a nutritious alternative ...

  9. Animal Feeding Operations

    Science.gov (United States)

    ... What's this? Submit Button Healthy Water Home Animal Feeding Operations Recommend on Facebook Tweet Share Compartir On ... Concentrated Animal Feeding Operations (CAFOs) What are Animal Feeding Operations (AFOs)? According to the United States Environmental ...

  10. Breastfeeding vs. Formula Feeding

    Science.gov (United States)

    ... A What's in this article? All About Breastfeeding Breastfeeding Challenges All About Formula Feeding Formula Feeding Challenges Making a Choice en español Lactancia materna versus lactancia artificial Choosing whether to breastfeed or formula feed their ...

  11. Marine and other aquatic dermatoses

    Directory of Open Access Journals (Sweden)

    Jandhyala Sridhar

    2017-01-01

    Full Text Available Occupational and recreational aquatic activity predisposes our population to a wide variety of dermatoses. Sunburn, urticaria, jellyfish stings, and contact dermatitis to rubber equipment are common allergies that are encountered in the aquatic environment. Among the infections, tinea versicolor, intertrigo, and verruca vulgaris are widespread. Swimmer's itch may occur due to skin penetration by schistosome cercariae, while free-floating nematocysts of marine coelenterates may precipitate seabather's eruption. “Suit squeeze” due to cutaneous barotrauma and lymphoedematous peau d'orange due to decompression are rare, described entities. This review serves as a ready reckoner for Indian dermatologists and medical practitioners to identify and manage these conditions.

  12. A comparison of the suction laryngoscope and the Macintosh laryngoscope in emergency medical technicians: a manikin model of severe airway haemorrhage.

    Science.gov (United States)

    Mitterlechner, T; Wipp, A; Herff, H; Wenzel, V; Strasak, A M; Felbinger, T W; Schmittinger, C A

    2012-01-01

    The use of a suction laryngoscope that enables simultaneous suction and laryngoscopy was evaluated. 34 emergency medical technicians intubated the trachea of a manikin with simulated upper airway haemorrhage using the suction laryngoscope and the Macintosh laryngoscope, in random order. When using the suction laryngoscope, the number of oesophageal intubations was lower (3/34 vs 11/34; p=0.021) and the time taken to intubation was shorter (mean (SD) 50 (15) vs 58 (27) s; p=0.041). In cases of airway haemorrhage, the use of the suction laryngoscope might be beneficial.

  13. Linear stability analysis of fluid flow between two parallel porous stationary plates with small suction and injection

    CERN Document Server

    Hinvi, L A; Orou, J B Chabi

    2013-01-01

    In this work, the linear stability of the viscous incompressible fluid flow between two parallel horizontal porous stationary plates with the assumption that there is a small constant suction at upper plate and a small constant injection at the lower plate is studied.The Navier-Stokes and continuous equations are reduced to an equation modified by the suction Reynolds number, which we call modified Orr-Sommerfeld equation. This equation is rewritten as an eigenvalue problem and is solved numerically using Matlab (Windows Version). The effect of small suction Reynolds number on the linear stability fluid flow is discussed.

  14. No drain, autologous transfusion drain or suction drain? A randomised prospective study in total hip replacement surgery of 168 patients

    OpenAIRE

    Cheung, G.; Carmont, MR; Bing, AJ; Kuiper, JH; Alcock, RJ; Graham, NM

    2010-01-01

    We performed a prospective, randomised controlled trial to assess the differences in the use of a conventional suction drain, an Autologous Blood Transfusion (ABT) drain and no drain, in 168 patients. There was no significant difference between the drainage from ABT drains ( mean : 345 ml) and the suction drain (314 ml). Forty percent of patients receiving a suction drain had a haemoglobin level less than 10 g/dL at 24 hours, compared to 35% with no drain and 28% with an ABT drain. Patients t...

  15. Aquatic Plant Water Quality Criteria

    Science.gov (United States)

    The USEPA, as stated in the Clean Water Act, is tasked with developing numerical Aquatic Life Critiera for various pollutants found in the waters of the United States. These criteria serve as guidance for States and Tribes to use in developing their water quality standards. The G...

  16. Aquatic Exercise for the Aged.

    Science.gov (United States)

    Daniel, Michael; And Others

    The development and implementation of aquatic exercise programs for the aged are discussed in this paper. Program development includes a discussion of training principles, exercise leadership and the setting up of safe water exercise programs for the participants. The advantages of developing water exercise programs and not swimming programs are…

  17. Morbillivirus infections in aquatic mammals

    NARCIS (Netherlands)

    I.K.G. Visser (Ilona); M.F. van Bressem; T. Barrett (Thomas); A.D.M.E. Osterhaus (Albert)

    1993-01-01

    textabstractInfections with morbilliviruses have caused heavy losses among different populations of aquatic mammals during the last 5 years. Two different morbilliviruses were isolated from disease outbreaks among seals in Europe and Siberia: phocid distemper virus-1 (PDV-1) and phocid distemper vir

  18. Aquatic Macrophyte Risk Assessment for Pesticides

    NARCIS (Netherlands)

    Maltby, L.; Arnold, D.; Arts, G.H.P.; Davies, J.; Heimbach, F.; Pickl, C.; Poulsen, V.

    2009-01-01

    Given the essential role that primary producers play in aquatic ecosystems, it is imperative that the potential risk of pesticides to the structure and functioning of aquatic plants is adequately assessed. This book discusses the assessment of the risk of pesticides with herbicidal activity to aquat

  19. Airfoil profile optimization of an air suction equipment with an air duct

    Directory of Open Access Journals (Sweden)

    Qiu Li

    2015-01-01

    Full Text Available On the basis of boundary layer with the airfoil profile, this research attempts to investigate the effect of the angle of spread of the winged air suction equipment on the efficiency of operation. The application of Fluent with the split-middle method under the identical operation mode is expected to optimize the spread angle. The investigated airfoil profile is NACA6413, of which the restrictions on the critical angle of spread suggested in literature will be overcome through the interactions between the internal and external flow fields. As a result, the air speed might increase. The wind tunnel test employed in this research offers the solid evidences to support this hypothesis. The test demonstrates that when the angle of spread is larger than 12°, the effect of accelerating the air flow is still observable. Following the optimization, the air suction effect of the equipment would be optimal when its angle of spread reached 30°.

  20. Laminar flow across an unbounded square cylinder with suction or injection

    Science.gov (United States)

    Pantokratoras, Asterios

    2017-02-01

    The flow around a horizontal square cylinder with uniform suction or injection at the front and rear sides is considered in the present paper. The problem is investigated numerically with a finite volume method using the SIMPLE algorithm. This flow has been investigated in the past for Reynolds numbers greater than 70. In the present work, the investigation is extended to very low Reynolds numbers (up to 0.001, Stokes flow) including eight different cases concerning suction-injection at the two sides. It is found that the drag coefficient takes negative and zero values in many cases and varies linearly at low Re numbers. In all eight cases, the vortices around the cylinder have been calculated. It is found that at low Re numbers, some vortices are symmetrical both about the horizontal and vertical cylinder axes.

  1. Study of swelling-shrinkage regularity of montmorillonite crystal and its relation with matric suction

    Institute of Scientific and Technical Information of China (English)

    谭罗荣; 孔令伟

    2001-01-01

    The swell-shrinking mineral of saturated and unsaturated expansive soil has important effect on engineering mechanical behavior. Based on the swelling-shrinkage change regularity of montmorillonite crystal in this paper, the actions between various interlayers of montmorillonite crystal are generally summarized as two kinds of action potentials-shrinkage potential and swelling potential. Moreover, through the experimental research and analysis, the expression formula for variations of the swelling potential and shrinkage potential with interlayer distance is presented, and the regularity of matric suction variations with interlayer distance is also obtained for unsaturated expansive soil. It may provide a new theoretical basis and research path for further research on the swelling-shrinkage mechanism of expansive soil and matric suction potential of unsaturated soil.

  2. Fluid Model of Sliding Suction Cup of Wall-climbing Robots

    Directory of Open Access Journals (Sweden)

    Fu Zhuang

    2008-11-01

    Full Text Available The adhering capability, one of the most important performance indexes of wall-climbing robots(WCRs, should be taken into account when a WCR is designed. This paper proposes a novel approach for investigating the adhering characteristics of the sliding suction cup (SSCs using fluid network theory to enhance the adhering capability of WCRs. The fluid models of the SSCs of two WCRs are developed and equivalent circuits in three cases are presented. The dynamic responses of negative pressure in SSCs are obtained and validated by a set of experiments. It indicated that the theoretical analysis is reasonable and can give some valuable design criteria on the structure parameters of SSCs and control strategies of suction force of SSCs.

  3. Hysteroscopy and suction evacuation of cesarean scar pregnancies: a case report and review.

    Science.gov (United States)

    Fylstra, Donald L

    2014-03-01

    Implantation of a pregnancy into the scar of a prior cesarean is an uncommon type of ectopic pregnancy. The incidence of cesarean scar pregnancy is thought to be one in 1800-2216 pregnancies. The increase in the incidence of cesarean scar pregnancy is thought to be a consequence of the increasing rates of cesarean delivery. The natural history of cesarean scar pregnancy is unknown. However, if such a pregnancy is allowed to continue, uterine scar rupture with hemorrhage and possible hysterectomy seem likely. Two early diagnosed cesarean scar pregnancies were treated with hysteroscopy and suction curettage removal. One required intramuscular methotrexate to resolve a persistent cesarean scar ectopic pregnancy. It would seem reasonable that simple suction evacuation would frequently leave chorionic villi imbedded within the cesarean scar, as the pregnancy is not within the endometrial cavity.

  4. Laboratory Setup for Vertically Loaded Suction Caisson Foundation in Sand and Validation of Responses

    DEFF Research Database (Denmark)

    Manzotti, E.; Vaitkunaite, Evelina; Ibsen, Lars Bo

    Wind energy obtained by means of wind turbine has been proved to be a concrete resource of green energy. Development of such structures requires research on offshore construction, since this is the direction for future improvement on this field. Wind turbines are relatively light and slender...... devices usually installed in farms, therefore many inexpensive foundations are needed. Suction Bucket foundations are a suitable option for this purpose, but for large scale utilization more research is required, especially for in-service performance. Size of offshore wind turbine has been increasing...... during the last years and, following this trend, design choice will turn into foundation composed of three or four suction bucket foundations, called respectively tripod and tetrapod. Overturning moment in tripod and tetrapod is carried by vertical loading; therefore vertical pull-out capacity is tested...

  5. Influence of Splitter Blades on the Cavitation Performance of a Double Suction Centrifugal Pump

    Directory of Open Access Journals (Sweden)

    Wei Yang

    2014-04-01

    Full Text Available In order to study the influence of splitter blades on double suction centrifugal pumps two impellers with and without splitter blades were investigated numerically and experimentally. Three-dimensional turbulence simulations with and without full cavitation model were applied to simulate the flow in the two pumps with different impellers. The simulation results agreed with the experiment results and the internal flows were analyzed. Both the numerical and experimental results show that by adding splitter blades the hydraulic performance and the cavitation performance of the pump are improved. The pump efficiency is increased especially at high flow rate condition. The pump high efficiency area is extended dramatically. At the same time since the splitter blades share some part of the blade loading, the pump critical NPSH value is decreased. Obvious pressure increase and velocity decrease at blade suction surface near leading edge were observed in the pump impeller with splitter blades. And the pump cavitation performance was improved consequently.

  6. Flow of an Elastico-viscous Fluid Past an Infinite Platewith Variable Suction

    Directory of Open Access Journals (Sweden)

    Ch. V. Ramana Murthy

    2007-07-01

    Full Text Available Unsteady state flow of an incompressible elastico-viscous fluid of second-order type pastan infinite vertical porous flat plate by considering uniform and variable suction normal to theplate has been studied  and an exact solution is obtained for the velocity field. In the presentsituation, only two prescribed boundary conditions are available while the governing equationof motion is of third-order due to the presence of elastico-viscosity parameter.  The conceptfollowing Walters has been used for a much more meaningful solution.  The results for thevelocity distribution and skin friction have been analysed and discussed for different values ofthe parameters encountered in the governing equation of motion and skin friction on the plate.It is found that the effect of elastico-viscosity  and suction has significant contribution on thebackflow at the wall

  7. Airway and feeding problems in infants with Fairbairn-Robin triad deformities

    Directory of Open Access Journals (Sweden)

    Susanna M. du Plessis

    2013-01-01

    Full Text Available Background: The majority of patients with Pierre Robin sequence in the subdivision Fairbairn-Robin triad (FRT, are born with glossoptosis, retro-/micrognathia and cleft or agenesis of the palate leading to feeding difficulties and airway obstruction. There is limited literature on these problems, and on methods used to address them.Objectives: Community nurses in the Facial Cleft Deformity Clinic evaluate associated airway obstruction and feeding problems and devise nursing interactions to address these. This retrospective study examined the incidence of airway and feeding difficulties in the neonatal, pre-surgical period, as well as the surgical and nutritional management of these infants.Method: Retrospective records of 215 infants with FRT were examined and data on incidence, airway and feeding difficulties and surgical and nutritional management was collected. Descriptive statistics, including average and percentage values, were compiled.Results: The incidence of FRT amongst the cleft palate patients was 6.0%, with 37.7% of these having feeding difficulties. However, surgical interventions such as glossopexy (5.6%, distraction osteogenesis (0.9% and tracheotomy (2.3% for airway management were seldom required. Most of the infants who had upper airway obstruction and feeding problems were handled by means of suction and drinking plates, along with additional specific feeding aids. This reduced airway obstruction in 70.6%, and feeding problems in 62.4% of these infants.Conclusion: Based on this study’s finding the introduction of the suction and drinking plate and the use of specific types of feeding devices and surgical management can improve growth and development in infants with FRT.

  8. Durophagy in sharks: feeding mechanics of the hammerhead Sphyrna tiburo.

    Science.gov (United States)

    Wilga, C D; Motta, P J

    2000-09-01

    This study investigates the motor pattern and head movements during feeding of a durophagus shark, the bonnethead Sphyrna tiburo, using electromyography and simultaneous high-speed video. Sphyrna tiburo feeds almost exclusively on hard-shelled crabs, with shrimp and fish taken occasionally. It captures crabs by ram feeding, then processes or reduces the prey by crushing it between molariform teeth, finally transporting the prey by suction for swallowing. The prey-crushing mechanism is distinct from that of ram or bite capture and suction transport. This crushing mechanism is accomplished by altering the duration of jaw adductor muscle activity and modifying jaw kinematics by the addition of a second jaw-closing phase. In crushing events, motor activity of the jaw adductor muscles continues (biting of the prey occurs as the jaws close and continues after the jaws have closed) throughout a second jaw-closing phase, unlike capture and transport events during which motor activity (biting) ceases at jaw closure. Sphyrna tiburo is able to take advantage of a resource (hard prey) that is not readily available to most sharks by utilizing a suite of durophagous characteristics: molariform teeth, a modified jaw protrusor muscle, altered jaw adductor activity and modified jaw kinematics. Sphyrna tiburo is a specialist feeder on crab prey as demonstrated by the lack of differences in kinematic or motor patterns when offered prey of differing hardness and its apparent lack of ability to modulate its behavior when feeding on other prey. Functional patterns are altered and coupled with modifications in dental and jaw morphology to produce diverse crushing behaviors in elasmobranchs.

  9. Analysis of Bearing Capacity of Suction Bucket Foundation Subjected to Horizontal and Moment Loadings

    OpenAIRE

    W.U. Ke; M.A. Mingyue

    2013-01-01

    The suction bucket foundation is not only supporting the vertical loading such as the sea platform and weight itself, but also subjecting to horizontal and moment loading due to wind and wave. The response of bucket foundation to combined Horizontal (H) and Moment (M) loading has been studied using 3D finite element analysis Then the proposed method is numerically implemented in the framework of the general-purpose FEM software ABAQUS. Relationship curve between the coefficient of ultimate be...

  10. Laboratory Setup for Vertically Loaded Suction Caisson Foundation in Sand and Validation of Responses

    OpenAIRE

    Manzotti, E.; Vaitkunaite, Evelina; Ibsen, Lars Bo

    2014-01-01

    Wind energy obtained by means of wind turbine has been proved to be a concrete resource of green energy. Development of such structures requires research on offshore construction, since this is the direction for future improvement on this field. Wind turbines are relatively light and slender devices usually installed in farms, therefore many inexpensive foundations are needed. Suction Bucket foundations are a suitable option for this purpose, but for large scale utilization more research is r...

  11. Study on diving behavior of sperm whales using suction cup attached TDR tag: an overview

    OpenAIRE

    Amano, Masao; YOSHIOKA, Motoi; MORI, Kyoichi

    2003-01-01

    Studies on diving behavior of marine mammals using data loggers including time depth recorders (TDR) are becoming popular these days. However, cetaceans, which do not come up to the land, have a difficulty in capturing the animal to attach these equipments. This has hindered wide usage of data loggers. Development of the method using suction cup to deploy the tag with data logger directly to swimming animals solved the problem accompanied with capture. We have applied this method to sperm wha...

  12. Active technique by suction to control the flow structure over a van model

    Science.gov (United States)

    Harinaldi, Budiarso, Warjito, Kosasih, Engkos A.; Tarakka, Rustan; Simanungkalit, Sabar P.

    2012-06-01

    Today research trend in car aerodynamics are carried out from the point of view of the durable development. Some car companies have the objective to develop control solution that enable to reduce the aerodynamic drag of vehicle. It provides the possibility to modify the flow separation to reduce the development of the swirling structures around the vehicle. In this study, a family van is modeled with a modified form of Ahmed's body by changing the orientation of the flow from its original form (modified/reversed Ahmed Body). This model is equipped with a suction on the rear side to comprehensively examine the pressure field modifications that occur. The investigation combines computational and experimental work. The computational simulation used is k-epsilon flow turbulence model. The reversed Ahmed body used in the investigation has slant angle (φ) 35° at the front part. In the computational work, meshing type is tetra/hybrid element with hex core type and the grid number is more than 1.7 million in order to ensure detail discretization and more accurate calculation results. The boundary condition is upstream velocity of 11.1 m/s. Mean free stream at far upstream region is assumed in a steady state condition and uniform. The suction velocity is set at 1 m/s. Meanwhile in the experimental work a reversed Ahmed model is tested in a controlled wind tunnel experiments. The main measurement is the drag aerodynamic measurement at rear of the body of the model using strain gage. The results show that the application of a suction in the rear part of the van model give the effect of reducing the wake and the vortex is formed. Aerodynamic drag reduction close to 24% for the computational approach and 14.8% for the experimental approach by introducing a suction have been obtained.

  13. Modeling Aquatic Macroinvertebrate Richness Using Landscape Attributes

    Directory of Open Access Journals (Sweden)

    Marcia S. Meixler

    2015-01-01

    Full Text Available We used a rapid, repeatable, and inexpensive geographic information system (GIS approach to predict aquatic macroinvertebrate family richness using the landscape attributes stream gradient, riparian forest cover, and water quality. Stream segments in the Allegheny River basin were classified into eight habitat classes using these three landscape attributes. Biological databases linking macroinvertebrate families with habitat classes were developed using life habits, feeding guilds, and water quality preferences and tolerances for each family. The biological databases provided a link between fauna and habitat enabling estimation of family composition in each habitat class and hence richness predictions for each stream segment. No difference was detected between field collected and modeled predictions of macroinvertebrate families in a paired t-test. Further, predicted stream gradient, riparian forest cover, and total phosphorus, total nitrogen, and suspended sediment classifications matched observed classifications much more often than by chance alone. High gradient streams with forested riparian zones and good water quality were predicted to have the greatest macroinvertebrate family richness and changes in water quality were predicted to have the greatest impact on richness. Our findings indicate that our model can provide meaningful landscape scale macroinvertebrate family richness predictions from widely available data for use in focusing conservation planning efforts.

  14. Cyanotoxins: Bioaccumulation and Effects on Aquatic Animals

    Directory of Open Access Journals (Sweden)

    Betina Kozlowsky-Suzuki

    2011-12-01

    Full Text Available Cyanobacteria are photosynthetic prokaryotes with wide geographic distribution that can produce secondary metabolites named cyanotoxins. These toxins can be classified into three main types according to their mechanism of action in vertebrates: hepatotoxins, dermatotoxins and neurotoxins. Many studies on the effects of cyanobacteria and their toxins over a wide range of aquatic organisms, including invertebrates and vertebrates, have reported acute effects (e.g., reduction in survivorship, feeding inhibition, paralysis, chronic effects (e.g., reduction in growth and fecundity, biochemical alterations (e.g., activity of phosphatases, GST, AChE, proteases, and behavioral alterations. Research has also focused on the potential for bioaccumulation and transferring of these toxins through the food chain. Although the herbivorous zooplankton is hypothesized as the main target of cyanotoxins, there is not unquestionable evidence of the deleterious effects of cyanobacteria and their toxins on these organisms. Also, the low toxin burden in secondary consumers points towards biodilution of microcystins in the food web as the predominant process. In this broad review we discuss important issues on bioaccumulation and the effects of cyanotoxins, with emphasis on microcystins, as well as drawbacks and future needs in this field of research.

  15. 真空吸铸设备的发展与展望%Development of Vacuum Suction Casting Equipments

    Institute of Scientific and Technical Information of China (English)

    陈善贤; 郝启堂; 李强; 李铁麟

    2012-01-01

    综述了国内外真空吸铸工艺以及真空吸铸设备的发展状况,描述了各种真空吸铸设备的结构和原理.重点介绍了美国Hitchiner公司开发的CLA法、CPV法、CV法、C3法等反重力真空吸铸工艺及其设备.展望了真空吸铸设备的发展趋势.%The development of the vacuum suction casting process and equipments both in domestic and overseas was summarized, and the structures and principles of some vacuum suction casting machines were also presented. Antigravity the vacuum suction casting process and equipments developed by Hitchiner, such as CLA, CPV, CV and C3, were emphasisly introduced. The development tendency of suction casting machines was prospected.

  16. A global approach to turbomachinery flow control: Loss reduction using endwall suction and midspan vortex generator jet blowing

    Science.gov (United States)

    Bloxham, Matthew Jon

    A flow control scheme using endwall suction and vortex generator jet (VGJ) blowing was employed in an effort to reduce the turbine passage losses associated with the endwall flow field and midspan separation. Unsteady midspan control at low Re had a significant impact on the wake area-average total pressure losses, decreasing the losses by 54%. Initially, the focus of the endwall control was the horseshoe vortex system. The addition of leading edge endwall suction resulted in an area-average total pressure loss reduction of 57%. The minimal additional gains achieved with leading edge endwall suction showed that the horseshoe vortex was a secondary contributor to endwall loss production (primary contributor-passage vortex). A similar flow control strategy was then employed with an emphasis on passage vortex (PV) control. During the design, a theoretical model was used that effectively predicted the trajectory of the passage vortex. The model required inviscid results obtained from two-dimensional CFD. It was used in the design of two flow control approaches, the removal and redirection approaches. The emphasis of the removal approach was the direct application of flow control on the endwall below the passage vortex trajectory. The redirection approach attempted to alter the trajectory of the PV by removing boundary layer fluid through judiciously placed suction holes. Suction hole positions were chosen using a potential flow model that emphasized the alignment of the endwall flow field with inviscid streamlines. Model results were validated using flow visualization and particle image velocimetry (PIV) in a linear turbine cascade comprised of the highly-loaded L1A blade profile. Detailed wake total pressure losses were measured while matching the suction and VGJ massflow rates, for the removal and redirection approaches at ReCx=25000 and blowing ratio, B, of 2. When compared with the no control results, the addition of steady VGJs and endwall suction reduced the wake

  17. Oro-naso-pharyngeal suction at birth: effects on respiratory adaptation of normal term vaginally born infants.

    Science.gov (United States)

    Estol, P C; Piriz, H; Basalo, S; Simini, F; Grela, C

    1992-01-01

    The effect of oro-naso-pharyngeal suction at birth on pulmonary mechanics is described in a random assigned controlled study of 40 normal term vaginally born infants. Twenty cases had their oro-naso-pharynx suctioned immediately after birth (S Group), whereas 20 were not suctioned in the neonatal period (NS Group). A computerized pneumotachographic system (MECVENT) was used for the assessment of respiratory mechanics (Dynamic Compliance (C. Dyn.) and Total Pulmonary Resistance (R) in inspiration and expiration at 10, 30 and 120 minutes after birth. In both groups the C. Dyn increased during the study period whereas the R decreased, mainly in the initial 30 minutes. No significant differences were observed between S and NS groups for any of the parameters of respiratory mechanics. The results obtained in this study provide no physiological basis to recommend routine airway suction at birth in normal, term, vaginally born infants.

  18. Comparison between nasal endoscopic suction cutter treatment of adenoidal hypertrophy and blind adenoid scraping by spatula

    Institute of Scientific and Technical Information of China (English)

    Hong-Xia Zhang; Zhu-Lin Chen; Duo-Xi Mao; Jing Liu

    2016-01-01

    Objective:To analyze the wound degree during suction cutter treatment of adenoidal hypertrophy and its effect on postoperative ventilation function.Methods: A total of 112 patients with adenoidal hypertrophy were randomly divided into observation group and control group (n=56), control group received blind adenoid scraping by spatula, observation group received suction cutter treatment, and then differences in serum levels of inflammatory cytokines and apoptosis factors as well as nasal ventilation function and lung function indexes were compared between two groups of patients after treatment.Results:Inflammatory cytokines IL-4, IL-6, TNF-α, ECP and ICAM-1 content in serum of observation group 2d after treatment were lower than those of control group, and apoptotic factors survivin, caspase-3, sFas and sFasL content in serum were lower than those of control group (P<0.05); nasal ventilation function parameters TIR, TER, NPRi and NPRe levels of observation group 1 week after treatment were lower than those of control group while IC and EC levels were higher than those of control group, and pulmonary function parameters VT, MV, PIEF, FEF25%, FEF50% and FEF75% levels were higher than those of control group (P<0.05). Conclusions:Suction cutter treatment of adenoid hypertrophy outstandingly improves the patients’ ventilation function, and also has the advantage of small wound.

  19. MHD Boundary Layer Flow of Dilatant Fluid in a Divergent Channel with Suction or Blowing

    Institute of Scientific and Technical Information of China (English)

    Krishnendu Bhattacharyya; G.C.Layek

    2011-01-01

    @@ An analysis is carried out to study a steady magnetohydrodynamic(MHD) boundary layer How of an electrically conducting incompressible power-law non-Newtonian fluid through a divergent channel.The channel walls are porous and subjected to either suction or blowing of equal magnitude of the same kind of fluid on both walls.The fluid is permeated by a magnetic field produced by electric current along the line of intersection of the channel walls.The governing partial differential equation is transformed into a self-similar nonlinear ordinary differential equation using similarity transformations.The possibility of boundary layer flow in a divergent channel is analyzed with the power-law fluid model.The analysis reveals that the boundary layer flow (without separation) is possible for the case of the dilatant fluid model subjected to suitable suction velocity applied through its porous walls,even in the absence of a magnetic field.Further, it is found that the boundary layer flow is possible even in the presence of blowing for a suitable value of the magnetic parameter.It is found that the velocity increases with increasing values of the power-law index for the case of dilatant fluid.The effects of suction/blowing and magnetic field on the velocity are shown graphically and discussed physical尔

  20. A pseudoepidemic of Mycobacterium chelonae infection caused by contamination of a fibreoptic bronchoscope suction channel.

    Science.gov (United States)

    Wang, H C; Liaw, Y S; Yang, P C; Kuo, S H; Luh, K T

    1995-08-01

    An unusual increase in the frequency of isolation of Mycobacterium chelonae subspecies chelonae from specimens of bronchial washings was found between September and December 1992 in National Taiwan University Hospital. During this period, a total of 123 patients underwent fibreoptic bronchoscopy with an Olympus P20. Seventy six patients had bronchial washing for bacteriological study and cytological examination. Acid-fast bacilli were found in 21 patients, in 18 of whom Mycobacterium chelonae were isolated from bronchial washing cultures. Eight patients were treated as mycobacterial infected, because of the presence of unexplained pulmonary lesion, positive acid-fast stain and culture for Mycobacterium chelonae. Diagnosis of lung cancer was delayed in one patient because of the initial negative cytological study and positive bacterial culture. The fibreoptic bronchoscope was disinfected by automated washing machine (EW-20, Olympus) using 2.3% glutaraldehyde according to a standard protocol. From a survey to search for possible sources of contamination, they were identified at the suction channel of four different bronchoscopes. This episode proved to be a pseudoepidemic. The contamination was controlled by extensive suction and rinsing of the channel with 70% alcohol immediately after disinfection by the automated bronchoscope disinfection machine. This study shows that, despite using the disinfection machine, the suction channel could still be contaminated with Mycobacterium chelonae. This may cause diagnostic confusion and unnecessary antimycobacterial treatment.

  1. Statistical characteristics of suction pressure signals for a centrifugal pump under cavitating conditions

    Science.gov (United States)

    Li, Xiaojun; Yu, Benxu; Ji, Yucheng; Lu, Jiaxin; Yuan, Shouqi

    2017-02-01

    Centrifugal pumps are often used in operating conditions where they can be susceptible to premature failure. The cavitation phenomenon is a common fault in centrifugal pumps and is associated with undesired effects. Among the numerous cavitation detection methods, the measurement of suction pressure fluctuation is one of the most used methods to detect or diagnose the degree of cavitation in a centrifugal pump. In this paper, a closed loop was established to investigate the pump cavitation phenomenon, the statistical parameters for PDF (Probability Density Function), Variance and RMS (Root Mean Square) were used to analyze the relationship between the cavitation performance and the suction pressure signals during the development of cavitation. It is found that the statistical parameters used in this research are able to capture critical cavitation condition and cavitation breakdown condition, whereas difficult for the detection of incipient cavitation in the pump. At part-load conditions, the pressure fluctuations at the impeller inlet show more complexity than the best efficiency point (BEP). Amplitude of PDF values of suction pressure increased steeply when the flow rate dropped to 40 m3/h (the design flow rate was 60 m3/h). One possible reason is that the flow structure in the impeller channel promotes an increase of the cavitation intensity when the flow rate is reduced to a certain degree. This shows that it is necessary to find the relationship between the cavitation instabilities and flow instabilities when centrifugal pumps operate under part-load flow rates.

  2. Comparison of paracetamol and fentanyl for pain relief during and after suction termination

    Science.gov (United States)

    Şahin, Ayça S.; Gülleroğlu, Aykan; Toker, Melike K.; Karabay, Ayşe G.; Adıyeke, Özal; Demiraran, Yavuz

    2016-01-01

    Objectives: To compare the combination of paracetamol (20 mg/kg) and propofol to fentanyl (1 µg/kg) and propofol in terms of providing adequate analgesia and a comparable recovery profile in suction termination procedures. Methods: This is a prospective, randomized clinical study in which we obtained informed consents from 146 women (fentanyl group: 76 [52.1%], paracetamol group: 70 [47.9%]) who were scheduled for suction curettage at the Istanbul Kanuni Sultan Suleyman Education and Training Hospital, Istanbul, Turkey in January 2015. Patients were randomly allocated into a fentanyl group or a paracetamol group. Visual analogue scores, modified Aldrete scores, and hemodynamic parameters were recorded during and after the surgical procedure. A record was also maintained of any adverse events. Results: When the modified Aldrete scores at 60 minutes, systolic pressures at 0 minutes, oxygen saturation at 10, 15, 20 minutes, diastolic blood pressure at 10, 15, 20 minutes, heart rates, and visual analogue scores were compared, there was no significant difference between groups (p>0.05). In the fentanyl group, systolic blood pressures at 5, 10, 15, 20 minutes and diastolic blood pressure at 5 minutes and oxygen saturation at 5 minutes were significantly lower (p<0.05). Conclusion: Our study demonstrates that the analgesic properties and recovery profiles of intravenous paracetamol is as effective as fentanyl when used in suction termination procedures. Further larger studies are still required. PMID:27146615

  3. Internal flow numerical simulation of double-suction centrifugal pump using DES model

    Science.gov (United States)

    Zhou, P. J.; Wang, F. J.; Yang, M.

    2012-11-01

    It is a challenging task for the flow simulation for a double-suction centrifugal pump, because the wall effects are strong in this type of pumps. Detached-eddy simulation (DES), referred as a hybrid RANS-LES approach, has emerged recently as a potential compromise between RANS based turbulence models and Large Eddy Simulation. In this approach, the unsteady RANS model is employed in the boundary layer, while the LES treatment is applied to the separated region. In this paper, S-A DES method and SST k-ω DES method are applied to the numerical simulation for the 3D flow in whole passage of a double-suction centrifugal pump. The unsteady flow field including velocity and pressure distributions is obtained. The head and efficiency of the pump are predicted and compared with experimental results. According to the calculated results, S-A DES model is easy to control the partition of the simulation when using near wall grid with 30 suction centrifugal pump. S-A DES method can capture more flow phenomenon than SST k - ω DES method. In addition, it can accurately predict the power performance under different flow conditions, and can reflect pressure fluctuation characteristics.

  4. MHD flow over a permeable stretching/shrinking sheet of a nanofluid with suction/injection

    Directory of Open Access Journals (Sweden)

    Sandeep Naramgari

    2016-06-01

    Full Text Available In this study we analyzed the influence of thermal radiation and chemical reaction on two dimensional steady magnetohydrodynamic flow of a nanofluid past a permeable stretching/shrinking sheet in the presence of suction/injection. We considered nanofluid volume fraction on the boundary is submissive controlled, which makes the present study entirely different from earlier studies and physically more realistic. The equations governing the flow are solved numerically. Effects of non-dimensional governing parameters on velocity, temperature and concentration profiles are discussed and presented through graphs. Also, coefficient of skin friction and local Nusselt number is investigated for stretching/shrinking and suction/injection cases separately and presented through tables. Comparisons with existed results are presented. Present results have an excellent agreement with the existed studies under some special assumptions. Results indicate that the enhancement in Brownian motion and thermophoresis parameters depreciates the nanoparticle concentration and increases the mass transfer rate. Dual solutions exist only for certain range of stretching/shrinking and suction/injection parameters.

  5. Effect of suction change on water content and total volume of an expansive clay

    Institute of Scientific and Technical Information of China (English)

    ZHAN Liang-tong; CHEN Ping; NG C.W.W.

    2007-01-01

    A laboratory study was carried out on both natural and compacted specimens to investigate the complex soil-water interaction in an unsaturated expansive clay. The laboratory study includes the measurement of soil-water characteristic curves, 1D free swelling tests, measurement of swelling pressure and shrinkage tests. The test results revealed that the air-entry value of the natural specimen was quite low due to cracks and fissures present. The hydraulic hysteresis of the natural specimen was relatively insignificant as compared with the compacted specimen. Within a suction range 0 to 500 kPa, a bilinear relationship between free swelling strain (or swelling pressure) and initial soil suction was observed for both the natural and compacted specimens. As a result of over-consolidation and secondary structures such as cementation and cracks, the natural specimens exhibited significant lower swelling (or swelling pressure) than the compacted specimen. The change of matric suction exerts a more significant effect on the water phase than on the soil skeleton for this expansive clay.

  6. Proposed Release Guides to Protect Aquatic Biota

    Energy Technology Data Exchange (ETDEWEB)

    Marter, W.L.

    2001-03-28

    At the request of South Carolina Department of Health and Environmental Control (SCDHEC) and the Department of Energy (DOE), the Savannah River Laboratory was assigned the task of developing the release guides to protect aquatic biota. A review of aquatic radioecology literature by two leading experts in the field of radioecology concludes that exposure of aquatic biota at one rad per day or less will not produce detectable deleterious effects on aquatic organisms. On the basis of this report, DOE recommends the use of one rad per day as an interim dose standard to protect aquatic biota.

  7. NEBULIZED VERSUS INTRAVENOUS LIGNOCAINE TO SUPPRESS THE HAEMODYNAMIC RESPONSE TO ENDOTRACHEAL SUCTION IN PATIENTS ON MECHANICAL VENTILATION

    Directory of Open Access Journals (Sweden)

    Ramana Prasad

    2015-09-01

    Full Text Available BACKGROUND: Cardiovascular response to tracheal suction is generally obtunded by intravenous lignocaine. We proposed that nebulized lignocaine in an equivalent dose could achieve a comparable suppression. PATIENTS & METHODS: The study was conducted in AMCU ACSR Govt . Medical College Nellore, d uring the period of Jan uary 2015 to April 2015. Twenty - six patients requiring tracheal suction through an endotra cheal or tracheostomy tube received 1.5 mg kg" 1 of lignocaine in the nebulized form or as an intravenous injection on two different occasions. Heart rate (HR and mean arterial pressure (MAP were recorded at baseline, after the administration of lignocain e, after two successive suctions and once in two minutes for the next 16 minutes. RESULTS: HR and MAP showed significant changes in both groups. HR increased significantly in both the groups at the end of the two suctions but returned back to the baseline by minute 4 in the IV lignocaine group (p<0.01 and minute 6 in the nebulization group (p<0.05. In the nebulized lignocaine group, MAP at the end of suction 2 was significantly higher than the MAP at the end of nebu l ization (p - 0.03. It decreased signific antly by minute 4 with values at minute 4 - 8 being significantly lower than at the end of suction 2 (p<0.05. In the intravenous lignocaine group, MAP at minute 4 - 16 was lower than MAP at the end of suction 2 (p<0.05. The MAP values at minute 6 - 16 were, in fact, lower than the baseline values (p<0.02. HR and MAP changes were not significantly different between the two routes of lignocaine administration. CONCLUSION: Cardiovascular response to tracheal suction is similar when lignocaine is administered either by intravenous or nebulized form.

  8. Septic arthritis of the knee: Presentation of a novel irrigation-suction system tested in a cadaver study

    Directory of Open Access Journals (Sweden)

    Weise Kuno

    2011-08-01

    Full Text Available Abstract Background The established treatment for bacterial arthritis of the knee joint is arthroscopic surgery with irrigation and debridement. The aim of this article is to summarize the relevant data in treating bacterial arthritis of the knee joint, and based on these findings to present a novel irrigation suction system, tested in a cadaver study, as an additional tool in the postoperative treatment phase of arthroscopic surgery for knee joint infections. Method The novel automated irrigation-suction system presented here was compared to conventional continuous suction irrigation in a total of six knee joints. All knee joints were filled with 80 ml methylene blue stain and rinsed by two different methods. Fluid specimens were taken after ten and twenty minutes to be compared by photometric extinction measurement at a wave length of 500 nm. Results After ten minutes, the average extinction was e1C = 0.8 for the continuous suction irrigation and e1N = 0.4 for the novel irrigation-suction system. After twenty minutes, we recorded an average extinction of e2C = 0.3 for continuous suction irrigation and e2N = 0.001 for the novel irrigation-suction system. The students t-test revealed superior results after ten and twenty minutes of washing out the knee joints with a p Conclusion A novel irrigation-suction system may be an effective tool for postoperative knee joint irrigation in arthroscopic therapy for bacterial arthritis of the knee. Further animal studies are needed to verify the effects in vivo.

  9. Production in aquatic macrophyte communities

    DEFF Research Database (Denmark)

    Binzer, Thomas; Sand-Jensen, Kaj

    2002-01-01

    -dimensional structure because of the strong drag and shear forces of moving water. This difference in canopy structure has been suggested to account for the three- to fivefold higher gross production rates in terrestrial than aquatic communities. To evaluate the effect of community structure in aquatic habitats, we...... to distribute photons evenly between the photosynthetic tissues. As scattering and attenuation in the water column increase, the effect of thallus structure on production declines and thin transparent macrophytes are more efficient at utilizing light than thick opaque macrophytes. The results confirm...... combined a simple mechanistic model and empirical measurements on artificially structured macroalgal communities (Ulva lactuca) with varying thallus absorptance and community density. Predicted and measured values corresponded closely and revealed that gross production in high-light environments...

  10. Oxidation mechanism and overall removal rates of endocrine disrupting chemicals by aquatic plants.

    Science.gov (United States)

    Reis, A R; Tabei, K; Sakakibara, Y

    2014-01-30

    The purpose of this study was to evaluate experimentally and theoretically the oxidation mechanisms and overall removal rates of phenolic endocrine disrupting chemicals (EDCs) by aquatic plants. EDCs used in this study were bisphenol-A (BPA), 2,4-dichlorophenol (2,4-DCP), 4-tert-octylphenol (4-t-OP), and pentachlorophenol (PCP). Referring to reported detection levels in aquatic environments and contaminated sites, the feed concentration of each EDC was set from 1 to 100μg/L. Experimental results showed that, except for PCP, phenolic EDCs were stably and concurrently removed by different types of aquatic plants over 70 days in long-term continuous treatments. Primal enzymes responsible for oxidation of BPA, 2,4-DCP, and 4-t-OP were peroxidases (POs). Moreover, enzymatic removal rates of BPA, 2,4-DCP, and 4-t-OP by POs were more than 2 orders of magnitude larger than those by aquatic plants. Assuming that overall removal rates of EDCs are controlled by mass transfer rates onto liquid films on the surface of aquatic plants, an electrochemical method based on the limiting current theory was developed to measure the mass transfer rates of EDCs. Because of extremely large removal rates of EDCs by POs, observed removal rates by aquatic plants were in reasonably good agreement with calculated results by a mathematical model developed based on an assumption that mass transfer limitation is a rate-limiting step.

  11. Feeding tube - infants

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007235.htm Feeding tube - infants To use the sharing features on this page, please enable JavaScript. A feeding tube is a small, soft, plastic tube placed ...

  12. Jejunostomy feeding tube

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000181.htm Jejunostomy feeding tube To use the sharing features on this ... vomiting Your child's stomach is bloated Alternate Names Feeding - jejunostomy tube; G-J tube; J-tube; Jejunum ...

  13. Nasogastric feeding tube

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000182.htm Nasogastric feeding tube To use the sharing features on this ... the nose. It can be used for all feedings or for giving a person extra calories. It ...

  14. Tube Feeding Troubleshooting Guide

    Science.gov (United States)

    Tube Feeding Troubleshoot ing Guide This guide is a tool to assist you, and should not replace your doctor’s ... everyone. table of contents Going Home with Tube Feedings....................................................2 Nausea and ... ...

  15. Breastfeeding vs. Formula Feeding

    Science.gov (United States)

    ... Parks EP, Shaikhkhalil A, Groleau V, Wendel D, Stallings VA. Feeding healthy infants, children, and adolescents. In: ... 2016:chap. Stettler N, Bhatia J, Parish A, Stallings VA. Feeding healthy infants, children, and adolescents. In: ...

  16. Feeding Your Newborn

    Science.gov (United States)

    ... for your child. These guidelines on breastfeeding and bottle feeding can help you make the decision that's right ... formula is a nutritious alternative to breast milk. Bottle feeding can offer more freedom and flexibility for moms, ...

  17. Neonatal herpes simplex virus infection following Jewish ritual circumcisions that included direct orogenital suction - New York City, 2000-2011.

    Science.gov (United States)

    2012-06-08

    Herpes simplex virus (HSV) infection commonly causes "cold sores" (HSV type 1 [HSV-1]) and genital herpes (HSV-1 or HSV type 2 [HSV-2]); HSV infection in newborns can result in death or permanent disability. During November 2000-December 2011, a total of 11 newborn males had laboratory-confirmed HSV infection in the weeks following out-of-hospital Jewish ritual circumcision, investigators from the New York City Department of Health and Mental Hygiene (DOHMH) learned. Ten of the 11 newborns were hospitalized; two died. In six of the 11 cases, health-care providers confirmed parental reports that the ritual circumcision included an ultra-Orthodox Jewish practice known as metzitzah b'peh, in which the circumciser (mohel, plural: mohelim) places his mouth directly on the newly circumcised penis and sucks blood away from the circumcision wound (direct orogenital suction). In the remaining cases, other evidence suggested that genital infection was introduced by direct orogenital suction (probable direct orogenital suction). Based on cases reported to DOHMH during April 2006-December 2011, the risk for neonatal herpes caused by HSV-1 and untyped HSV following Jewish ritual circumcision with confirmed or probable direct orogenital suction in New York City was estimated at 1 in 4,098 or 3.4 times greater than the risk among male infants considered unlikely to have had direct orogenital suction. Oral contact with a newborn's open wound risks transmission of HSV and other pathogens. Circumcision is a surgical procedure that should be performed under sterile conditions. Health-care professionals advising parents and parents choosing Jewish ritual circumcision should inquire in advance whether direct orogenital suction will be performed, and orogenital suction should be avoided.

  18. Use of closed suction drain after primary total knee arthroplasty – an overrated practice

    Directory of Open Access Journals (Sweden)

    Sharma Gaurav M.

    2016-01-01

    Full Text Available Purpose: The age-old practice of closed suction drain following orthopedic procedures has been challenged since past few decades. Our aim was to assess the effectiveness of closed suction drain after total knee arthroplasty. Materials and methods: One hundred twenty patients (135 knees with primary Total Knee Arthroplasty were divided into a study group (no drain and a control group (drain used. Inclusion criteria were grade 3 and grade 4 osteoarthritis of the knee. Revision cases and rheumatoid arthritis were excluded. Parameters assessed were pain, pre and post-op Hb, dressing change, early infection, ecchymosis and duration of stay. Results were calculated using Western Ontario and McMaster Universities Osteoarthritis Index and Oxford Knee scoring systems at two weeks, six months and one year. Results: Mean age was 72.03 ± 6.68 in study group and 71.38 ± 7.02 in control group. Pre and post op Hb was 12.1678 ± 1.3220 (study group, 12.1803 ± 1.2717 (control group and 9.8373 ± 1.5703 (study group, 9.7918 ± 1.4163 (control group. There was one case of early infection in both groups which was controlled by oral antibiotics. Change of dressing and ecchymosis were more in the study group. Duration of hospital stay was more in the control group p < 0.0006 (statistically significant. Conclusion: There is no added advantage of closed suction drain over no drain usage and this practice can safely be brought to a halt.

  19. Manual vibrocompression and nasotracheal suctioning in post-operative period of infants with heart deffects

    Directory of Open Access Journals (Sweden)

    Maíra Seabra de Assumpção

    2013-12-01

    Full Text Available OBJECTIVE: To evaluate the impact of manual vibrocompression and nasotracheal suctioning on heart (hr and respiratory (rr rates, peripheral oxygen saturation (SpO2, pain and respiratory distress in infants in the postoperative period of a cardiac surgery. METHODS: Randomized controlled trial, in which the assessments were performed by the same physiotherapist in two moments: before and after the procedure. The infants were randomly divided into two groups: Intervention (IG, with manual chest vibrocompression, nasotracheal suctioning and resting; and Control CG, with 30 minutes of rest. Cardiorespiratory data (SpO2; hr; rr were monitored and the following scales were used: Neonatal Infant Pain Scale (NIPS, for pain evaluation, and Bulletin of Silverman-Andersen (BSA, for respiratory distress assessment. The data were verified by analysis of variance (ANOVA for repeated measures, being significant p<0.05. RESULTS: 20 infants with heart disease, ten in each group (seven acyanotic and three cyanotic were enrolled, with ages ranging from zero to 12 months. In the analysis of the interaction between group and time, there was a significant difference in the variation of SpO2 (p=0.016, without changes in the other variables. Considering the main effect on time, only rr showed a significant difference (p=0.001. As for the group main effect, there were no statistical differences (SpO2 - p=0.77, hr - p=0.14, rr - p=0.17, NIPS - p=0.49 and BSA - p=0.51 . CONCLUSIONS: The manual vibrocompression and the nasotracheal suctioning applied to infants in postoperative of cardiac surgery did not altered SpO2 and rr, and did not trigger pain and respiratory distress. [Brazilian Registry of Clinical Trials (ReBEC: REQ: 1467].

  20. EPA Region 7 Aquatic Focus Areas (ECO_RES.R7_AQUATIC_FOCUS_AREAS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This shapefile consists of 347 individual Aquatic Ecological System (AES) polygons that are the Aquatic Conservation Focus Areas for EPA Region 7. The focus areas...

  1. Aquatic and Terrestrial Environment 2004

    DEFF Research Database (Denmark)

    Andersen, J. M.; Boutrup, S.; Bijl, L. van der

    This report presents the 2004 results of the Danish National Monitoring and Assess-ment Programme for the Aquatic and Terrestrial Environments (NOVANA). 2004 was the first year in which terrestrial nature was included in the monitoring pro-gramme. The report reviews the state of the groundwater......, watercourses, lakes and marine waters and the pressures upon them and reviews the monitoring of terrestrial natural habitats and selected plants and animals. The report is based on the annual reports prepared for each subprogramme by the Topic Centres. The latter reports are mainly based on data collected...

  2. Food and feeding behaviour of Mozambique tilapia (Oreochromis mossambicus Peters from Borna Reservoir of Maharashtra, India

    Directory of Open Access Journals (Sweden)

    Vishwas balasaheb Sakhare

    2016-12-01

    Full Text Available The food analysis of 80 specimens of Oreochromis mossambicus collected from Borna Reservoir of Maharashtra, India revealed that the food of juveniles mainly consisted of rotifers (35%, followed by copepods (30%, Chlorophyceae (20%, Bacillariophyceae (10% and aquatic insects (5%. While the food items recorded in the gut of adults were Chlorophyceae (40%, followed by Bacillariophyceae (30%, rotifers (15%, copepods (10% and aquatic insects (5%. During present study it was found that the juveniles of O. mossamobicus mainly feed on zooplankton, and adults on phytoplankton. Intense feeding was noticed during summer season and juveniles were the active feeders.

  3. Breast-Feeding Twins: Making Feedings Manageable

    Science.gov (United States)

    ... more than one baby? Here's help breast-feeding twins or other multiples, from getting positioned and ensuring ... babies who are born prematurely, as are many twins and higher order multiples. Breast milk is easier ...

  4. Radiation effect on temperature distribution in three-dimensional Couette flow with suction or injection

    Institute of Scientific and Technical Information of China (English)

    Bhupendra.Kumar Sharma; Mamta Agarwal; R.C.Chaudhary

    2007-01-01

    A theoretical analysis of three-dimensional Couette flow with radiation effect on temperature distribution has been analysed, when the injection of the fluid at the lower stationary plate is a transverse sinusoidal one and its corresponding removal by constant suction through the upper porous plate is in uniform motion. Due to this type of injection velocity, the flow becomes three-dimensional. The effect of Prandtl number,radiation parameter and injection parameter on rate of heat transfer has been examined by the help of graphs. The Prandtl number has a much greater effect on the temperature distribution than the injection or radiation parameter.

  5. A suction blister model reliably assesses skin barrier restoration and immune response.

    Science.gov (United States)

    Smith, Tracey J; Wilson, Marques A; Young, Andrew J; Montain, Scott J

    2015-02-01

    Skin wound healing models can be used to detect changes in immune function in response to interventions. This study used a test-retest format to assess the reliability of a skin suction blister procedure for quantitatively evaluating human immune function in repeated measures type studies. Up to eight suction blisters (~30 mm(2)) were induced via suction on each participant's left and right forearm (randomized order; blister session 1 and 2), separated by approximately one week. Fluid was sampled from each blister, and the top layer of each blister was removed to reveal up to eight skin wounds. Fluid from each wound was collected 4, 7 and 24h after blisters were induced, and proinflammatory cytokines were measured. Transepidermal water loss (TEWL), to assess skin barrier recovery, was measured daily at each wound site until values were within 90% of baseline values (i.e., unbroken skin). Sleep, stress and inflammation (i.e., factors that affect wound healing and immune function), preceding the blister induction, were assessed via activity monitors (Actical, Philips Respironics, Murrysville, Pennsylvania), the Perceived Stress Scale (PSS) and C-reactive protein (CRP), respectively. Area-under-the-curve and TEWL, between blister session 1 and 2, were compared using Pearson correlations and partial correlations (controlling for average nightly sleep, PSS scores and CRP). The suction blister method was considered reliable for assessing immune response and skin barrier recovery if correlation coefficients reached 0.7. Volunteers (n=16; 12 M; 4F) were 23 ± 5 years [mean ± SD]. Time to skin barrier restoration was 4.9 ± 0.8 and 4.8 ± 0.9 days for sessions 1 and 2, respectively. Correlation coefficients for skin barrier restoration, IL-6, IL-8 and MIP-1α were 0.9 (Pblister method is sufficiently reliable for assessing skin barrier restoration and immune responsiveness. This data can be used to determine sample sizes for cross-sectional or repeated-measures types of

  6. Effects of mass transfer on MHD flow of casson fluid with chemical reaction and suction

    Directory of Open Access Journals (Sweden)

    S. A. Shehzad

    2013-03-01

    Full Text Available Effect of mass transfer in the magnetohydrodynamic flow of a Casson fluid over a porous stretching sheet is addressed in the presence of a chemical reaction. A series solution for the resulting nonlinear flow is computed. The skin friction coefficient and local Sherwood number are analyzed through numerical values for various parameters of interest. The velocity and concentration fields are illustrated for several pertinent flow parameters. We observed that the Casson parameter and Hartman number have similar effects on the velocity in a qualitative sense. We further analyzed that the concentration profile decreases rapidly in comparison to the fluid velocity when we increased the values of the suction parameter.

  7. Blood loss in major liposuction procedures: a comparison study using suction-assisted versus ultrasonically assisted lipoplasty.

    Science.gov (United States)

    Karmo, F R; Milan, M F; Silbergleit, A

    2001-07-01

    The blood loss that accompanies liposuction procedures has always been a concern. Tumescent injection of the targeted area of liposuction with dilute lidocaine and epinephrine solution has minimized intraoperative blood loss. Proponents of a newer ultrasonically assisted lipoplasty technique have claimed many benefits over traditional suction-assisted lipoplasty. However, few quantitative data are available on the intraoperative blood loss and the significance of postoperative anemia using the ultrasonic method. A prospective clinical observational design was used to investigate 38 patients undergoing suction-assisted lipoplasty and 37 patients undergoing ultrasound-assisted lipoplasty in whom the liposuction aspirate was expected to be more than 1000 ml. These patients were investigated with preoperative measurement of hemoglobin, platelet count, prothrombin time, partial thromboplastin time, and postoperative measurement of hemoglobin on the seventh postoperative day. In addition, hemoglobin concentration and whole blood volume were calculated from the infranatant portion of the liposuction aspirate. The mean +/- SD volume of the liposuction aspirate was 2901 +/- 1471 ml for suction-assisted compared with 2741 +/- 1086 ml for ultrasound-assisted lipoplasty. The mean +/- SD of whole blood volume in liposuction aspirate per case was 36 +/- 50.82 ml for suction-assisted lipoplasty and 36 +/- 28.62 ml for ultrasound-assisted lipoplasty. The mean +/- SD of the preoperative hemoglobin concentration was 13.93 +/- 0.99 g/dl for suction-assisted lipoplasty and 14.05 +/- 1.16 g/dl for ultrasound-assisted lipoplasty, whereas the mean +/- SD of the postoperative hemoglobin concentration was 13 +/- 1.42 g/dl for suction-assisted lipoplasty and 13.05 +/- 1.32 g/dl for ultrasound-assisted lipoplasty. The mean decrease in hemoglobin on the seventh postoperative day was 0.93 +/- 0.92 g/dl for suction-assisted lipoplasty and 1 +/- 0.64 g/dl for ultrasound-assisted lipoplasty. The

  8. Thopaz Portable Suction Systems in Thoracic Surgery: An end user assessment and feedback in a tertiary unit

    Directory of Open Access Journals (Sweden)

    Cantlin Teresa

    2011-04-01

    Full Text Available Abstract Background Thoracic surgical patients have chest drains inserted to enable re-expansion of lungs, to clear contents from the pleural cavity which sometimes require negative suction. Suction impedes mobility, may have variable suction delivery and increases risk of infection. Assessment of air-leak in conventional drains is not scientific and is subjective. Thopaz chest drain system is a portable suction unit which allows mobilization of the patient, with scientific digital flow recordings and an in built alarm system. Methods We evaluated the utility, staff and patient feedback of this device in a pilot evaluation in a regional thoracic unit in a structured format over a period of two months. Staff responses were graded on a scale of 1 to 6 [1 Excellent to 6 Poor]. Results 120 patients who underwent elective bullectomy/pleurectomy, VATS lung biopsies, VATS metastectomy and lung resections were evaluated. The staff feedback forms were positive. The staff liked the system as it was more scientific and accurately recordable. It made nursing and physiotherapy easier as they could mobilise patients early. The patients liked the compact design, weightlessness and the silence. It enabled mobilisation of the patients and scientific removal of chest drain. Conclusions Thopaz digital suction units were found to be user friendly and were liked by the staff and patients. The staff feedback stated the devices to be objective and scientific in making decisions about removal and enabled mobilisation.

  9. Numerical Investigation of Wall Cooling and Suction Effects on Supersonic Flat-Plate Boundary Layer Transition Using Large Eddy Simulation

    Directory of Open Access Journals (Sweden)

    Suozhu Wang

    2015-02-01

    Full Text Available Reducing friction resistance and aerodynamic heating has important engineering significance to improve the performances of super/hypersonic aircraft, so the purpose of transition control and turbulent drag reduction becomes one of the cutting edges in turbulence research. In order to investigate the influences of wall cooling and suction on the transition process and fully developed turbulence, the large eddy simulation of spatially evolving supersonic boundary layer transition over a flat-plate with freestream Mach number 4.5 at different wall temperature and suction intensity is performed in the present work. It is found that the wall cooling and suction are capable of changing the mean velocity profile within the boundary layer and improving the stability of the flow field, thus delaying the onset of the spatial transition process. The transition control will become more effective as the wall temperature decreases, while there is an optimal wall suction intensity under the given conditions. Moreover, the development of large-scale coherent structures can be suppressed effectively via wall cooling, but wall suction has no influence.

  10. Effect of tracheobronchial suction on respiratory resistance in intubated preterm babies.

    Science.gov (United States)

    Prendiville, A; Thomson, A; Silverman, M

    1986-12-01

    Measurements of the resistance, time constant, and compliance of the respiratory system were made in 25 mechanically ventilated, preterm babies on 32 occasions, using the single breath technique. Patients were classified according to the level of respiratory resistance by reference to a population of 36 babies studied over the first two days of life before airway secretions had become apparent. There was a highly significant fall in both the resistance and time constant measurements after tracheobronchial suction or lavage for infants whose pretreatment values of resistance were greater than the reference mean. When tracheobronchial toilet was effective in removing secretions the changes in resistance and time constant values were again significant. No changes in compliance values were noted. Severe but clinically inapparent mucous obstruction of the airways was revealed in two infants by a progressively rising respiratory system resistance during continuous monitoring. The need for and efficacy of tracheobronchial suction and lavage could be determined by such techniques for monitoring the resistance of the respiratory system during mechanical ventilation.

  11. Review of theModern developments in Suction processes of IC Engines

    Directory of Open Access Journals (Sweden)

    Dhruv Chawda

    2014-09-01

    Full Text Available This review paper deals with the evolution of the general processes employed in the suction process of IC Engines. The suction process has evolved from the traditional use of carburettors to much more sophisticated systems like CRDi, MPFi, etc. used in modern days. In doing so, various parameters such as the volumetric efficiency and the turbulence, etc. inside the engine have to be considered. Additional processes such as supercharging and turbocharging are employed to improve these parameters. It is also highly desirable to vary the Air-Fuel ratio effectively according to the speed of the engine for better power output and mileage. Thus researchers have developed several ways over the years to achieve it. Recent research work being carried out in this field is in the areas of Pressure Wave Superchargers, Variable Geometry Turbochargers, Multiple Intake valves, Shrouded Intake Valves, Camless Engines etc. Many of these technologies have been employed in the industry such as the DTS-Si, TDi&i-vtec Engines. Thus, the Automobile Industry has come a long way in evolving the intake processes and further developments will always be on the way.

  12. Suction sampling as a significant source of error in molecular analysis of predator diets.

    Science.gov (United States)

    King, R A; Davey, J S; Bell, J R; Read, D S; Bohan, D A; Symondson, W O C

    2012-06-01

    The molecular detection of predation is a fast growing field, allowing highly specific and sensitive detection of prey DNA within the gut contents or faeces of a predator. Like all molecular methods, this technique is prone to potential sources of error that can result in both false positive and false negative results. Here, we test the hypothesis that the use of suction samplers to collect predators from the field for later molecular analysis of predation will lead to high numbers of false positive results. We show that, contrary to previous published work, the use of suction samplers resulted in previously starved predators testing positive for aphid and collembolan DNA, either as a results of ectopic contamination or active predation in the collecting cup/bag. The contradictory evidence for false positive results, across different sampling protocols, sampling devices and different predator-prey systems, highlights the need for experimentation prior to mass field collections of predators to find techniques that minimise the risk of false positives.

  13. A History of Suction-Type Laminar Flow Control with Emphasis on Flight Research

    Science.gov (United States)

    Braslow, Albert L.

    1999-01-01

    Laminar-flow control is an area of aeronautical research that has a long history at NASA's Langley Research Center, Dryden Flight Research Center, their predecessor organizations, and elsewhere. In this monograph, the author, who spent much of his career at Langley working with this research, presents a history of that portion of laminar-flow technology known as active laminar-flow control, which employs suction of a small quantity of air through airplane surfaces. This important technique offers the potential for significant reduction in drag and, thereby, for large increases in range or reductions in fuel usage for aircraft. For transport aircraft, the reductions in fuel consumed as a result of laminar-flow control may equal 30 percent of present consumption. Given such potential, it is obvious that active laminar-flow control with suction is an important technology. In this study, the author covers the early history of the subject and brings the story all the way to the mid-1990s with an emphasis on flight research, much of which has occurred at Dryden. This is an important monograph that not only encapsulates a lot of history in a brief compass but also does so in language that is accessible to non-technical readers. NASA is publishing it in a format that will enable it to reach the wide audience the subject deserves.

  14. Transport of bromide measured by soil coring, suction plates, and lysimeters under transient flow conditions.

    Science.gov (United States)

    Kasteel, R.; Pütz, Th.; Vereecken, H.

    2003-04-01

    Lysimeter studies are one step within the registration procedure of pesticides. Flow and transport in these free-draining lysimeters do not reflect the field situation mainly because of the occurence of a zone of local saturation at the lower boundary (seepage face). The objective of this study is to evaluate the impact of flow and transport behaviour of bromide detected with different measuring devices (lysimeters, suction plates, and soil coring) by comparing experimental results with numerical simulations in heterogeneous flow domains. We applied bromide as a small pulse to the bare soil surface (Orthic Luvisol) of the three devices and the displacement of bromide was regurlarly sampled for three years under natural wheather conditions. Based on the mean breakthrough curves we observe experimentally that lysimeters have a lower effective pore-water velocity and exhibit more solute spreading resulting in a larger dispersivity than the suction plates. This can be ascribed to the artefact of the lower boundary. We performed numerical transport simulations in 2-D heterogeneous flow fields (scaling approach) choosing appropriate boundary conditions for the various devices. The simulations allow to follow the temporal evolution of flow and transport processes in the various devices and to gain additional process understanding. We conclude that the model is essentially capable to reproduce the main experimental findings only if we account for the spatial correlation structure of the hydraulic properties, i.e. soil heterogeneity.

  15. Analysis and control of flow at suction connection in high-speed centrifugal pump

    Directory of Open Access Journals (Sweden)

    Wen-wu Song

    2016-12-01

    Full Text Available The backflow vortexes at the suction connection in high-speed centrifugal pumps have negative effect on the flow field. Setting an orifice plate in front of the inducer is able to decrease the negative effect caused by backflow vortexes. The traditional plate is able to partially control the backflow vortexes, but a small part of the vortex is still in the inlet and the inducer. Four new types of orifice plates were created, and the control effects on backflow vortexes were analyzed. The ANSYS-CFX software was used to numerically simulate a high-speed centrifugal pump. The variations of streamline and velocity vectors at the suction connection were analyzed. Meanwhile, the effects of these plates on the impeller pressure and the internal flow field of the inducer were analyzed. Numerically, simulation and experimental data analysis methods were used to compare the head and efficiency of the high-speed pumps. The results show that the C-type orifice plate can improve the backflow vortex, reduce the low-pressure area, and improve the hydraulic performance of the high-speed pump.

  16. Finite Element Analysis of Laterally Loaded Suction Caisson in Anisotropic Clay

    Institute of Scientific and Technical Information of China (English)

    WANG Dong; JIN Xia

    2006-01-01

    Naturally deposited clay is usually characterized by strength anisotropy; however, the effect of anisotropy on the capacity of a suction caisson was seldom investigated. The conventional Hill yield surface includes undrained strengths in triaxial shear, simple shear and pressuremeter shear simultaneously but it can not specify differences in respect to the mode of loading for a given shearing mode. A new technique of updating strength is integrated into incremental finite element (FE) calculation to consider the mode of loading, which is applied to the study of variation of capacity with the aspect ratio of suction caissons in anisotropic clay. Compared with the upper bound limit analysis, FE simulation is capable of offering the lateral capacity of short caissons. In the normal range of anisotropic strength properties, the Mises yield surface with simple shear strength predicts the horizontal capacity of which the error is less than 10% for rough caissons and 15% for smooth caissons. It is also found that the friction of caisson affects the capacity significantly.

  17. Neonatal Herpes Simplex Virus Type 1 Infection and Jewish Ritual Circumcision With Oral Suction: A Systematic Review.

    Science.gov (United States)

    Leas, Brian F; Umscheid, Craig A

    2015-06-01

    Jewish ritual circumcision rarely but occasionally includes a procedure involving direct oral suction of the wound, which can expose an infant to infection with herpes simplex virus type 1 (HSV-1). This practice has provoked international controversy in recent years, but no systematic review of the clinical literature has previously been published. We designed this review to identify and synthesize all published studies examining the association between circumcision with direct oral suction and HSV-1 infection. Our search strategy identified 6 published case series or case reports, documenting 30 cases between 1988 and 2012. Clinical findings were consistent with transmission of infection during circumcision, although the evidence base is limited by the small number of infections and incomplete case data. Published evidence suggests that circumcision with direct oral suction has resulted in severe neonatal illness and death from HSV-1 transmission, but further research is necessary to clarify the risk of infection.

  18. Numerical Solution for the Effect of Suction or Injection on Flow of Nanofluids Past a Stretching Sheet

    Science.gov (United States)

    Abd Elazem, Nader Y.

    2016-06-01

    The flow of nanofluids past a stretching sheet has attracted much attention owing to its wide applications in industry and engineering. Numerical solution has been discussed in this article for studying the effect of suction (or injection) on flow of nanofluids past a stretching sheet. The numerical results carried out using Chebyshev collocation method (ChCM). Useful results for temperature profile, concentration profile, reduced Nusselt number, and reduced Sherwood number are discussed in tabular and graphical forms. It was also demonstrated that both temperature and concentration profiles decrease by an increase from injection to suction. Moreover, the numerical results show that the temperature profiles decrease at high values of Prandtl number Pr. Finally, the present results showed that the reduced Nusselt number is a decreasing function, whereas the reduced Sherwood number is an increasing function at fixed values of Prandtl number Pr, Lewis number Le and suction (or injection) parameter s for variation of Brownian motion parameter Nb, and thermophoresis parameter Nt.

  19. The concentration distribution around a growing gas bubble in a bio tissue under the effect of suction process.

    Science.gov (United States)

    Mohammadein, S A

    2014-07-01

    The concentration distribution around a growing nitrogen gas bubble in the blood and other bio tissues of divers who ascend to surface too quickly is obtained by Mohammadein and Mohamed model (2010) for variant and constant ambient pressure through the decompression process. In this paper, the growing of gas bubbles and concentration distribution under the effect of suction process are studied as a modification of Mohammadein and Mohamed model (zero suction). The growth of gas bubble is affected by ascent rate, tissue diffusivity, initial concentration difference, surface tension and void fraction. Mohammadein and Mohamed model (2010) is obtained as a special case from the present model. Results showed that, the suction process activates the systemic blood circulation and delay the growth of gas bubbles in the bio tissues to avoid the incidence of decompression sickness (DCS).

  20. Effects of hydrologic connectivity on aquatic macroinvertebrate assemblages in different marsh types

    Science.gov (United States)

    Kang, Sung-Ryong; King, Sammy L.

    2013-01-01

    Hydrologic connectivity can be an important driver of aquatic macroinvertebrate assemblages. Its effects on aquatic macroinvertebrate assemblages in coastal marshes, however, are relatively poorly studied. We evaluated the effects of lateral hydrologic connectivity (permanently connected ponds: PCPs; temporary connected ponds: TCPs), and other environmental variables on aquatic macroinvertebrate assemblages and functional feeding groups (FFGs) in freshwater, brackish, and saline marshes in Louisiana, USA. We hypothesized that (1) aquatic macroinvertebrate assemblages in PCPs would have higher assemblage metric values (density, biomass, Shannon-Wiener diversity) than TCPs and (2) the density and proportional abundance of certain FFGs (i.e. scrapers, shredders, and collectors) would be greater in freshwater marsh than brackish and saline marshes. The data in our study only partially supported our first hypothesis: while freshwater marsh PCPs had higher density and biomass than TCPs, assemblage metric values in saline TCPs were greater than saline PCPs. In freshwater TCPs, long duration of isolation limited access of macroinvertebrates from adjacent water bodies, which may have reduced assemblage metric values. However, the relatively short duration of isolation in saline TCPs provided more stable or similar habitat conditions, facilitating higher assemblage metric values. As predicted by our second hypothesis, freshwater PCPs and TCPs supported a greater density of scrapers, shredders, and collectors than brackish and saline ponds. Aquatic macroinvertebrate assemblages seem to be structured by individual taxa responses to salinity as well as pond habitat attributes.

  1. Purification of Water by Aquatic Plants

    OpenAIRE

    Morimitsu, Katsuhito; Kawahigashi, Tatsuo

    2013-01-01

    [Abstract] Water quality purification of many water systems including those occurring in rivers depends to a great degree on water quality purification activities of aquatic plants and microbes. This paper presents a discussion of results, based on laboratory experiments, of purification by aquatic plants.

  2. Control of Fish and Aquatic Plants.

    Science.gov (United States)

    Hesser, R. B.; And Others

    This agriculture extension service publication from Pennsylvania State University is a handbook for the water body manager. The bulk of the contents deals with aquatic plant control. The different types of aquatic plants, their reproduction and growth, and their role in the ecology of the water body are introduced in this main section. Also, the…

  3. Aquatic Therapy: A Viable Therapeutic Recreation Intervention.

    Science.gov (United States)

    Broach, Ellen; Dattilo, John

    1996-01-01

    Reviews literature on the effects of aquatic therapy (swimming and exercise) to improve function. Research shows that aquatic therapy has numerous psychological and physical benefits, and it supports the belief that participation can provide a realistic solution to maintaining physical fitness and rehabilitation goals while engaging in enjoyable…

  4. Aquatic Therapy. Making Waves in Therapeutic Recreation.

    Science.gov (United States)

    Broach, Ellen; Dattilo, John

    1996-01-01

    Therapeutic recreation professionals often use aquatic therapy to improve physiological and psychological functioning, and they have reported improvements for people with many different types of disabilities. The paper discusses aquatic therapy methods, water as a therapeutic environment, professional training and development, and lifestyle…

  5. Estimating Aquatic Insect Populations. Introduction to Sampling.

    Science.gov (United States)

    Chihuahuan Desert Research Inst., Alpine, TX.

    This booklet introduces high school and junior high school students to the major groups of aquatic insects and to population sampling techniques. Chapter 1 consists of a short field guide which can be used to identify five separate orders of aquatic insects: odonata (dragonflies and damselflies); ephemeroptera (mayflies); diptera (true flies);…

  6. Half versus full vacuum suction drainage after modified radical mastectomy for breast cancer- a prospective randomized clinical trial[ISRCTN24484328

    Directory of Open Access Journals (Sweden)

    Singh JP

    2005-01-01

    Full Text Available Abstract Background Suction drains are routinely used after modified radical mastectomy and are an important factor contributing to increased hospital stay as the patients are often discharged only after their removal. Amongst various factors that influence the amount of postoperative drainage, the negative suction pressure applied to the drain has been reported to be of great significance. While a high negative suction pressure is expected to drain the collection and reduce the dead space promptly, it may also prevent the leaking lymphatics from closing and lead to increased drainage from the wound. Against this background a prospective randomized clinical study was conducted to compare the amount and duration of drainage between a half negative suction and full vacuum suction drainage in patients following modified radical mastectomy. The associated postoperative morbidity was also compared between the two groups. Methods 85 FNAC (fine needle aspiration cytology proven cases of locally advanced breast cancer were randomized. (Using randomly ordered sealed envelops, which were opened immediately before the closure of the wound in to 50 patients with full vacuum suction (pressure = 700 g/m2 and 35 cases in to half vacuum suction drainage (pressure = 350 g/m2 groups. The two groups were comparable in respect of age, weight, and technique of operation and extent of axillary dissection. Surgery was performed by the same surgical team comprising of five surgeons (two senior and three resident surgeons using a standardized technique with electrocautery. External compression dressing was provided over the axilla for first 48 hrs and following that patients were encouraged to do active and passive shoulder exercises. The outcomes measured were postoperative morbidity and the length of hospital stay. Statistical methods used: Descriptive studies were performed with SPSS version 10 and group characteristics were compared using student t-test. Results

  7. Unsteady boundary layer flow and heat transfer over an exponentially shrinking sheet with suction in a copper-water nanofluid

    Institute of Scientific and Technical Information of China (English)

    Aurang Zaib; Krishnendu Bhattacharyya; Sharidan Shafie

    2015-01-01

    An analysis of unsteady boundary layer flow and heat transfer over an exponentially shrinking porous sheet filled with a copper-water nanofluid is presented. Water is treated as a base fluid. In the investigation, non-uniform mass suction through the porous sheet is considered. Using Keller-box method the transformed equations are solved numerically. The results of skin friction coefficient, the local Nusselt number as well as the velocity and temperature profiles are presented for different flow parameters. The results showed that the dual non-similar solutions exist only when certain amount of mass suction is applied through the porous sheet for various unsteady parameters and nanoparticle volume fractions. The ranges of suction where dual non-similar solution exists, become larger when values of unsteady parameter as well as nanoparticle volume fraction increase. So, due to unsteadiness of flow dynamics and the presence of nanoparticles in flow field, the requirement of mass suction for existence of solution of boundary layer flow past an exponentially shrinking sheet is less. Furthermore, the velocity boundary layer thickness decreases and thermal boundary layer thickness increases with increasing of nanoparticle volume fraction in both non-similar solutions. Whereas, for stronger mass suction, the velocity boundary layer thickness becomes thinner for the first solution and the effect is opposite in the case of second solution. The temperature inside the boundary layer increases with nanoparticle volume fraction and decreases with mass suction. So, for the unsteadiness and for the presence of nanoparticles, the flow separation is delayed to some extent.

  8. Is gastric sham feeding really sham feeding?

    Science.gov (United States)

    Sclafani, A; Nissenbaum, J W

    1985-03-01

    Rats were fitted with gastric cannulas, food deprived, and allowed to drink a sugar solution that drained out of the opened cannula; i.e., the rats sham-fed. Although this procedure is thought to prevent absorption of ingested food, it was found that the sham feeding of a 32% glucose or sucrose solution significantly elevated blood glucose levels. The addition of acarbose, a drug that inhibits the digestion of sucrose, to the 32% sucrose solution blocked the blood glucose rise, as did closing the pylorus with an inflatable pyloric cuff. Neither the drug nor the cuff, however, reduced the amount of sucrose solution consumed. These findings indicate that gastric sham feeding does not necessarily prevent the digestion and absorption of food, although absorption is not essential for the appearance of a vigorous sham-feeding response. Nevertheless the possibility that neural or hormonal feedback from the stomach contributes to the sham-feeding response cannot be excluded, and until this issue is resolved the results of gastric sham-feeding studies should be interpreted with caution.

  9. Complex Feeding Decisions

    Directory of Open Access Journals (Sweden)

    Anna Miles PhD

    2016-08-01

    Full Text Available Objective: Where swallowing difficulties are chronic or progressive, or a patient is palliative, tube feeding is often not deemed appropriate. Instead, patients continue to eat and drink despite the risks of pneumonia and death. There is currently little evidence to guide clinical practice in this field often termed “risk feeding.” This qualitative study investigated staff, patient, and family member perceptions of risk feeding practices in one New Zealand hospital. Method: Twenty-nine staff members and six patients and/or their family were interviewed. Results: Thematic analysis revealed four global themes: supporting practice, communication, complexity of feeding decisions, and patient and family-centered care. Staff described limited education and organizational policy around risk feeding decisions. Communication was considered a major factor in the success. Conclusion: Feeding decisions are complex in the hospital environment. The themes identified in this study provide a foundation for hospital guideline development and implementation.

  10. Unsteady Stagnation Point Flow and Heat Transfer over a Stretching/Shrinking Sheet with Suction or Injection

    Directory of Open Access Journals (Sweden)

    M. Suali

    2012-01-01

    Full Text Available The unsteady stagnation point flow and heat transfer over a stretching/shrinking sheet with suction/injection is studied. The governing partial differential equations are converted into nonlinear ordinary differential equations using a similarity transformation and solved numerically. Both stretching and shrinking cases are considered. Results for the skin friction coefficient, local Nusselt number, velocity, and temperature profiles are presented for different values of the governing parameters. It is found that the dual solutions exist for the shrinking case, whereas the solution is unique for the stretching case. Numerical results show that the range of dual solutions increases with mass suction and decreases with mass injection.

  11. Linear Stabily analysis of hydromagnetic Couette flow with small injection/suction through the modified Orr-Sommerfeld equation

    CERN Document Server

    Hinvi, L A; Orou, J B Chabi

    2013-01-01

    This paper analyses the effects of small injection/suction Reynolds number, Hartmann number, permeability parameter and wave number on a viscous incompressilbe electrically conduction fluid flow in a parallel porous channel. The plates of the channel with small constant injection/suction, have constant temperature. The upper plate is allowed to mouve in flow direction and the lower plate is kept at rest. A magnetic field of uniform strength is also applied normally to the plates what are parallel. The originality of the paper is to study the effect of the above parameter in temporal linear stabilty analysis of the flow throught the modified Orr-Sommerfeld equation.

  12. Post-pyloric feeding

    Institute of Scientific and Technical Information of China (English)

    Eva Niv; Zvi Fireman; Nachum Vaisman

    2009-01-01

    Postpyloric feeding is an important and promising alternative to parenteral nutrition. The indications for this kind of feeding are increasing and include a variety of clinical conditions, such as gastroparesis, acute pancreatitis, gastric outlet stenosis, hyperemesis (including gravida), recurrent aspiration, tracheoesophageal fistula and stenosis in gastroenterostomy. This review discusses the differences between pre- and postpyloric feeding, indications and contraindications, advantages and disadvantages, and provides an overview of the techniques of placement of various postpyloric devices.

  13. Cetacean brains: how aquatic are they?

    Science.gov (United States)

    Marino, Lori

    2007-06-01

    The adaptation of cetaceans to a fully aquatic lifestyle represents one of the most dramatic transformations in mammalian evolutionary history. Two of the most salient features of modern cetaceans are their fully aquatic lifestyle and their large brains. This review article will offer an overview of comparative neuroanatomical research on aquatic mammals, including analyses of odontocete cetacean, sirenian, pinniped, and fossil archaeocete brains. In particular, the question of whether a relationship exists between being fully aquatic and having a large brain is addressed. It has been hypothesized that the large, well-developed cetacean brain is a direct product of adaptation to a fully aquatic lifestyle. The current consensus is that the paleontological evidence on brain size evolution in cetaceans is not consistent with this hypothesis. Cetacean brain enlargement took place millions of years after adaptation to a fully aquatic existence. Neuroanatomical comparisons with sirenians and pinnipeds provide no evidence for the idea that the odontocete's large brain, high encephalization level, and extreme neocortical gyrification is an adaptation to a fully aquatic lifestyle. Although echolocation has been suggested as a reason for the high encephalization level in odontocetes, it should be noted that not all aquatic mammals echolocate and echolocating terrestrial mammals (e.g., bats) are not particularly highly encephalized. Echolocation is not a requirement of a fully aquatic lifestyle and, thus, cannot be considered a sole effect of aquaticism on brain enlargement. These results indicate that the high encephalization level of odontocetes is likely related to their socially complex lifestyle patterns that transcend the influence of an aquatic environment.

  14. Largemouth bass (Micropterus salmoides) switch feeding modalities in response to sensory deprivation.

    Science.gov (United States)

    Gardiner, Jayne M; Motta, Philip J

    2012-04-01

    Animals use a suite of sensory modalities to precisely locate and capture prey. While numerous studies have examined the effects of sensory deprivation on the behaviors leading to prey capture and while it is generally believed that information in the pre-strike period determines the way fish capture prey, this study is the first to examine the contribution of sensory information to jaw kinematics during capture. Largemouth bass were filmed using high-speed videography while capturing live mosquitofish. Bass were examined intact, with visual deprivation under infrared light, and with lateral line deprivation following treatment with cobalt chloride. Deprived of visual cues, this visual ram-feeding predator switches towards suction-based feeding to successfully capture prey. They approach prey slowly but open their mouths more rapidly, which has been shown to result in greater buccal pressure, causing their prey to move a greater distance at a more rapid velocity as they are being drawn into the predators' mouths. Deprived of lateral line cues, bass have higher forward velocities during capture and capture prey earlier in the gape cycle. This study demonstrates that sensory pre-strike information directly affects the capture modality employed by fishes and that fish can modulate between ram and suction not only by adjusting the amount of ram by increasing or decreasing their movements, but also by actively increasing the amount of suction used. These results suggest that the ability to modulate feeding behavior may allow animals to not only exploit a broader breadth of prey items, but also to be capable of doing so in a wider variety of environments.

  15. Danger of zooplankton feeding

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Jiang, H.; Colin, S.P.

    2010-01-01

    Zooplankton feed in any of three ways: they generate a feeding current while hovering, cruise through the water or are ambush feeders. Each mode generates different hydrodynamic disturbances and hence exposes the grazers differently to mechanosensory predators. Ambush feeders sink slowly and ther......Zooplankton feed in any of three ways: they generate a feeding current while hovering, cruise through the water or are ambush feeders. Each mode generates different hydrodynamic disturbances and hence exposes the grazers differently to mechanosensory predators. Ambush feeders sink slowly...

  16. Infant feeding: formula, solids.

    Science.gov (United States)

    Barness, L A

    1985-04-01

    This article discusses and evaluates current formulas, traces their continual improvement (based largely on new information on breast milk composition), and then discusses the question of supplemental feedings.

  17. Bite force and feeding kinematics in the eastern North Pacific Kyphosidae.

    Science.gov (United States)

    Moran, Clinton Joseph; Ferry, Lara

    2014-04-01

    Some fishes that feed on attached food items possess an intramandibular joint (IMJ), which is thought to increase maximum gape and facilitate contact between the tooth-bearing surface and the substrate. However, the mechanical consequences of using an IMJ to remove attached food items from the substrate are still poorly understood. We examined the most prominent eastern North Pacific kyphosid, the scraper: Girella nigricans and two other kyphosids, Medialuna californiensis and Hermosilla azurea, which occupy similar habitats. Of the three species, G. nigricans had the highest theoretical bite force per unit length. We examined the feeding mechanics of G. nigricans in two different feeding scenarios: a scraping behavior elicited on a block of brine shrimp gelatin and a picking behavior elicited on Ulva sp. We measured cranial elevation, lower jaw rotation, premaxillary protrusion, premaxillary rotation, gape maximum, and intramandibular rotation. Ulva treatments produced significantly greater cranial rotation, when compared to gelatin treatments. Gelatin treatments were associated with greater lower jaw rotation and larger gape. Premaxillary rotation and premaxillary protrusion did not differ between treatments. Intramandibular rotation occurred only when G. nigricans physically contacted the gelatin, suggesting the IMJ is a passive joint with no associated musculature. We also noted that G. nigricans do not appear to use suction to draw food into the mouth. The lack of suction and the presence of the IMJ suggest that the jaws of G. nigricans are specialized for maximizing jaw force when scraping.

  18. Aquatic polymers can drive pathogen transmission in coastal ecosystems.

    Science.gov (United States)

    Shapiro, Karen; Krusor, Colin; Mazzillo, Fernanda F M; Conrad, Patricia A; Largier, John L; Mazet, Jonna A K; Silver, Mary W

    2014-11-22

    Gelatinous polymers including extracellular polymeric substances (EPSs) are fundamental to biophysical processes in aquatic habitats, including mediating aggregation processes and functioning as the matrix of biofilms. Yet insight into the impact of these sticky molecules on the environmental transmission of pathogens in the ocean is limited. We used the zoonotic parasite Toxoplasma gondii as a model to evaluate polymer-mediated mechanisms that promote transmission of terrestrially derived pathogens to marine fauna and humans. We show that transparent exopolymer particles, a particulate form of EPS, enhance T. gondii association with marine aggregates, material consumed by organisms otherwise unable to access micrometre-sized particles. Adhesion to EPS biofilms on macroalgae also captures T. gondii from the water, enabling uptake of pathogens by invertebrates that feed on kelp surfaces. We demonstrate the acquisition, concentration and retention of T. gondii by kelp-grazing snails, which can transmit T. gondii to threatened California sea otters. Results highlight novel mechanisms whereby aquatic polymers facilitate incorporation of pathogens into food webs via association with particle aggregates and biofilms. Identifying the critical role of invisible polymers in transmission of pathogens in the ocean represents a fundamental advance in understanding and mitigating the health impacts of coastal habitat pollution with contaminated runoff.

  19. Selection of Feed Intake or Feed Efficiency

    DEFF Research Database (Denmark)

    Veerkamp, Roel F; Pryce, Jennie E; Spurlock, Diane

    2013-01-01

    . In February 2013, the co-authors discussed how information on DMI should be incorporated in the breeding decisions. The aim of this paper is to present the overall discussion and main positions taken by the group on four topics related to feed efficiency: i) breeding goal definition; ii) biological variation...

  20. Creep Feeding Beef Calves

    OpenAIRE

    2005-01-01

    Creep feeding is the managerial practice of supplying supplemental feed (usually concentrates) to the nursing calf. Milk from a lactating beef cow furnishes only about 50 percent of the nutrients that a 3-4 month-old calf needs for maximum growth.

  1. [Application of deactivating properties of some sorbents in aquaculture feed production].

    Science.gov (United States)

    Vasukevich, T A; Nitievskaya, L S

    2014-01-01

    The possibility and effectiveness of application of selective sorbents for fish feed production in aquaculture in the area exposed to the radioactive pollution were studied. The investigations of the fish feed deactivating properties with additives of ferrocyn and potassium alginate, and magnesium on whitefish fry-fingerlings and yearlings were carried out. The study has shown that the ferrocyn performance is greater than 99% regardless of the fish age. 1% ferrocyn addition to feed allows increasing the acceptable concentration of feed compo- nents polluted by the above norm cesium radionuclide up to 20 times. The alginate additives in feed provide almost double decrease in the activity of fish tissues. The optimally effective alginate dose should exceed the calcium concentration in feed up to 4 times. It was found that utilization of the feedstock (fish meal, crops and legumes, oil meal and oil cake) polluted by radionuclides is possible in combined aquaculture feed pro- duction. The application of sorbents in feed will allow increasing the amount permissible for use of the feed components polluted above the norm; ensure the radiation safety of feed and, finally, the protection of aquatic biological resources from radioactive contamination. It is shown that the sorbent additive in feed is also jus- tified in case of fish farming in closed waters affected by radioactive pollution. Feeding by mixed fodder with the sorbent additives prevents fish from radionuclide intake from natural food sources.

  2. NASDA next-generation aquatic habitat for space shuttle and ISS

    Science.gov (United States)

    Masukawa, M.; Ochiai, T.; Kamigaichi, S.; Uchida, S.; Kono, Y.; Takamatsu, T.; Sakimura, T.

    The National Space Development Agency of Japan (NASDA) has more than 20 years of experience developing aquatic animal experiment facilities. These include the Vestibular Function Experiment Unit (VFEU), Aquatic Animal Experiment Unit (AAEU) and another VFEU for marine fish. Each facility had functions such as life support for up to 15 days, water quality control system, gas exchange by artificial lung, video observation through a window by a crewmember, day/night cycle control, feeding system for medaka (AAEU only), and more. We are now studying the next -generation aquatic animal experiment facility or the Aquatic Habitat (AQH) for both Space Shuttle and Space Station use. AQH will have many new capabilities missing in earlier facilities. The following functions are of particular importance: long-term life support for up to 90 days, multigeneration breeding (for medaka and zebrafish), automatic feeding system adaptable for young of fish and amphibians, water quality control for long-term experiments, air-water interface, a computer-driven specimen-monitoring system housed in the facilities, and a specimen sampling system including eggs. A prototype breeding system and the specimen-monitoring system were designed and tested. The prototype breeding system consists of a closed water loop, two 700ml fish chambers with LED lighting, a small artificial lung, and a nitrification bacteria filter. Medaka adult fish were able to mate and spawn in this small breeding system, and the young could grow to adult fish. The water quality control system also worked successfully. For amphibians, the breeding test using tadpoles of xenopus is also starting. We have many difficult technological problems to resolve, but development of AQH is going well. In this paper, we will introduce the results of the component-level test and the concept of AQH. In the future, many space biological experiments will be conducted, especially in the areas of developmental biology, neurophisiology, and

  3. Transition feeding of sows

    DEFF Research Database (Denmark)

    Theil, Peter Kappel

    2015-01-01

    becomes catabolic due to the high priority of milk production and to current feeding practices. Indeed, feed is changed from a gestation to a lactation diet for most sows and the feed supply typically goes from a restricted supply to an ad libitum allowance. In addition, transition sows are often exposed...... the first few days of lactation, and milk yield increases throughout the transition period and becomes the most important determinant of nutrient requirements. Thus, nutrient requirements of transition sows are affected by many intrinsic factors and these requirements change rapidly, yet, sow feeding...... practices do not acknowledge these changes. Development of new feeding strategies specifically adapted for the transition sow is likely of importance to match the rapid changes in nutrient requirements....

  4. Human Exploitation of Aquatic Landscapes. Editorial

    Directory of Open Access Journals (Sweden)

    Ricardo Fernandes

    2014-11-01

    Full Text Available Aquatic landscapes such as rivers, lakes, and seas played an important role in past human behaviour, affecting modes of subsistence, patterns of mobility, access to material resources, and technological choices and their developments. The interaction with aquatic landscapes was also influential in the establishment of economic and social structures and in the formation of communal identities. The aim of this special themed issue of Internet Archaeology is to contribute to a better understanding of different forms of human interaction with aquatic landscapes.

  5. Aquatic invasive species: Lessons from cancer research

    Science.gov (United States)

    Sepulveda, Adam; Ray, Andrew; Al-Chokhachy, Robert K.; Muhlfeld, Clint C.; Gresswell, Robert E.; Gross, Jackson A.; Kershner, Jeffrey L.

    2014-01-01

    Aquatic invasive species are disrupting ecosystems with increasing frequency. Successful control of these invasions has been rare: Biologists and managers have few tools for fighting aquatic invaders. In contrast, the medical community has long worked to develop tools for preventing and fighting cancer. Its successes are marked by a coordinated research approach with multiple steps: prevention, early detection, diagnosis, treatment options and rehabilitation. The authors discuss how these steps can be applied to aquatic invasive species, such as the American bullfrog (Lithobates catesbeianus), in the Northern Rocky Mountain region of the United States, to expedite tool development and implementation along with achievement of biodiversity conservation goals.

  6. A Mixed Picture of AQUATIC PRODUCTS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Aquatic products constitute an important part of China's international trade in agricultural products with the strongest competitiveness for export.The aquatic products industry of apparent competitive edge has maintained a considerable trade surplus despite the general trend of trade deficit among agricultural products in recent years.Nevertheless,the great changes taking place in the global economic and trade pattern in late years have given rise to the increasing uncertainties of the supply and demand as well as the price in the international aquatic products market.

  7. The effect of resonant driving and damping on dynamic suction pumping

    Science.gov (United States)

    Battista, Nicholas; Miller, Laura

    2016-11-01

    Impedance pumping (or dynamic suction pumping) drives flow through a a flexible valveless tube with a single region of actuation. It is a profoundly complex pumping mechanism given that the flow velocities and directions generated depend nonlinearly upon the driving frequency, material properties, duty factor, and location of the actuation point. Given the simplicity of its actuation, it is used in biomedical devices and is thought to generate flow in a number of biological systems. In this study, we numerically simulate an elastic tube with mass using the immersed boundary method and explore the performance when it is driven over a range of frequencies and damping factors. Flow is maximized during resonance, and bulk transport is minimal when the tube is over-damped.

  8. Alternative Shape of Suction Caisson to Reduce Risk of Buckling under high Pressure

    DEFF Research Database (Denmark)

    Madsen, Søren; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

    2013-01-01

    by uniform external pressure and vertical forces. The bucket foundation does not require heavy installation equipment, but since it is constructed as a thin steel shell structure, instability, in the form of buckling, becomes a crucial issue during installation. Typically, the bucket foundation is a large...... cylindrical monopod foundation made of steel. In this paper, an alternative design/shape of the suction caisson, having a smaller risk of buckling under high pressure is presented. The risk of structural buckling is addressed using numerical methods to determine the buckling pressures of the re......-designed bucket foundation during installation. Further, the effect of the lateral restraint offered by the surrounding soil on the buckling pressures is analysed. It is found that the new design enables a significantly larger buckling load compared to the traditional design....

  9. The magnetohydrodynamic stagnation point flow of a nanofluid over a stretching/shrinking sheet with suction.

    Science.gov (United States)

    Mansur, Syahira; Ishak, Anuar; Pop, Ioan

    2015-01-01

    The magnetohydrodynamic (MHD) stagnation point flow of a nanofluid over a permeable stretching/shrinking sheet is studied. Numerical results are obtained using boundary value problem solver bvp4c in MATLAB for several values of parameters. The numerical results show that dual solutions exist for the shrinking case, while for the stretching case, the solution is unique. A stability analysis is performed to determine the stability of the dual solutions. For the stable solution, the skin friction is higher in the presence of magnetic field and increases when the suction effect is increased. It is also found that increasing the Brownian motion parameter and the thermophoresis parameter reduces the heat transfer rate at the surface.

  10. Analysis of Bearing Capacity of Suction Bucket Foundation Subjected to Horizontal and Moment Loadings

    Directory of Open Access Journals (Sweden)

    W.U. Ke

    2013-07-01

    Full Text Available The suction bucket foundation is not only supporting the vertical loading such as the sea platform and weight itself, but also subjecting to horizontal and moment loading due to wind and wave. The response of bucket foundation to combined Horizontal (H and Moment (M loading has been studied using 3D finite element analysis Then the proposed method is numerically implemented in the framework of the general-purpose FEM software ABAQUS. Relationship curve between the coefficient of ultimate bearing capacity and displacement is obtained by the application of load-displacement controlled method in homogeneous soft foundation the failure envelope of foundation in the M-H is obtained by the application of swipe testing. The behavior is explained using upper bound plasticity mechanisms suggested by the soil deformation mechanisms observed in the finite element analysis. The numerical results computed by the proposed method will be helpful in engineering practices.

  11. The Magnetohydrodynamic Stagnation Point Flow of a Nanofluid over a Stretching/Shrinking Sheet with Suction

    Science.gov (United States)

    Mansur, Syahira; Ishak, Anuar; Pop, Ioan

    2015-01-01

    The magnetohydrodynamic (MHD) stagnation point flow of a nanofluid over a permeable stretching/shrinking sheet is studied. Numerical results are obtained using boundary value problem solver bvp4c in MATLAB for several values of parameters. The numerical results show that dual solutions exist for the shrinking case, while for the stretching case, the solution is unique. A stability analysis is performed to determine the stability of the dual solutions. For the stable solution, the skin friction is higher in the presence of magnetic field and increases when the suction effect is increased. It is also found that increasing the Brownian motion parameter and the thermophoresis parameter reduces the heat transfer rate at the surface. PMID:25760733

  12. Dissipation on Steady MHD Marangoni Convection Flow over a Flat Surface with Suction and Injection

    Directory of Open Access Journals (Sweden)

    S. Mohammed Ibrahim

    2013-01-01

    Full Text Available The combined effects of radiation and mass transfer on a steady MHD two-dimensional Marangoni convection flow over a flat surface in presence of Joule heating and viscous dissipation under influence of suction and injection is studied numerically. The general governing partial differential equations are transformed into a set of nonlinear ordinary differential equations by using unique similarity transformation. Numerical solutions of the similarity equations are obtained using the Runge-Kutta method along with shooting technique. The effects of governing parameters on velocity, temperature, and concentration as well as interface velocity, the surface temperature gradient, and the surface concentration gradient were presented in graphical and tabular forms. Comparisons with previously published work are performed and the results are found to be in excellent agreement.

  13. Stability and coherent structures of the asymptotic suction boundary layer over a heated plate

    CERN Document Server

    Zammert, Stefan; Eckhardt, Bruno

    2016-01-01

    The asymptotic suction boundary layer (ASBL) is a parallel shear flow that becomes turbulent in a bypass transition in parameter regions where the laminar profile is stable. We here add a temperature gradient perpendicular to the plate and explore the interaction between convection and shear in determining the transition. We find that the laminar state becomes unstable in a subcritical bifurcation and that the critical Rayleigh number and wave number depend strongly on the Prandtl number. We also track several secondary bifurcations and identify states that are localized in two directions, showing different symmetries. In the subcritical regime, transient turbulent states which are connected to exact coherent states and follow the same transition scenario as found in linearly stable shear flows are identified and analyzed. The study extends the bypass transition scenario from shear flows to thermal boundary layers and shows the intricate interactions between thermal and shear forces in determining critical po...

  14. Numerical Computation of Flow and Heat Transfer from an Enclosed Rotating Disk with Suction and Injection

    Directory of Open Access Journals (Sweden)

    R. S. Agarwal

    1980-04-01

    Full Text Available The Newton Raphson technique has been employed to solve the set of non-linear equations governing the problem of flow and heat transfer from an enclosed rotating disc. /The disc called rotor is subjected to uniform injection while the top of the housing called stator, to an equal suction. The results for small Reynold numbers are found in good agreement to that obtained earlier by series solution. The radial and transverse velocity profiles for large Reynolds have been plotted in the regions of no recirculation. The effect of net radial inflow and outflow on temperature in the no-recirculation region has also been studied. The method is significant in this respect that it yields satisfactory results for large Reynolds numbers.

  15. Cooperative Suction by Vertical Capillary Array Pump for Controlling Flow Profiles of Microfluidic Sensor Chips

    Directory of Open Access Journals (Sweden)

    Emi Tamechika

    2012-10-01

    Full Text Available A passive pump consisting of integrated vertical capillaries has been developed for a microfluidic chip as an useful component with an excellent flow volume and flow rate. A fluidic chip built into a passive pump was used by connecting the bottoms of all the capillaries to a top surface consisting of a thin layer channel in the microfluidic chip where the thin layer channel depth was smaller than the capillary radius. As a result the vertical capillaries drew fluid cooperatively rather than independently, thus exerting the maximum suction efficiency at every instance. This meant that a flow rate was realized that exhibited little variation and without any external power or operation. A microfluidic chip built into this passive pump had the ability to achieve a quasi-steady rather than a rapidly decreasing flow rate, which is a universal flow characteristic in an ordinary capillary.

  16. The magnetohydrodynamic stagnation point flow of a nanofluid over a stretching/shrinking sheet with suction.

    Directory of Open Access Journals (Sweden)

    Syahira Mansur

    Full Text Available The magnetohydrodynamic (MHD stagnation point flow of a nanofluid over a permeable stretching/shrinking sheet is studied. Numerical results are obtained using boundary value problem solver bvp4c in MATLAB for several values of parameters. The numerical results show that dual solutions exist for the shrinking case, while for the stretching case, the solution is unique. A stability analysis is performed to determine the stability of the dual solutions. For the stable solution, the skin friction is higher in the presence of magnetic field and increases when the suction effect is increased. It is also found that increasing the Brownian motion parameter and the thermophoresis parameter reduces the heat transfer rate at the surface.

  17. Dust control equipment of UO type used in the suction or combined ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Frydel, W.; Steindor, M. [KOMAG, Gliwice (Poland). Mining Mechanization Centre

    2001-07-01

    Systems for dust control and ventilation of roadways, using suction or forced (combined) ventilation, are a combination of dust control installations of the UO type and the equipment for the ventilation of roadways. The electrical equipment, essential for supplying and controlling the installation as well as methane detectors, are incorporated. The system ensures safe and efficient dust control and ventilation of roadways and guarantees proper inter co-ordination of units, which form part of it. Satisfactory solutions for the system have been possible by the installation of efficient and safe dust control equipment and the use of special vortex ventubes, removing methane accumulated under the roof and operating under conditions of high dust concentration and methane explosion risk. The solutions described are used in all in Polish workings mine. Since their installation no dust or methane explosions have occurred. At the same time the incidence of pneumoconiosis cases has been reduced. 2 figs.

  18. Effect of closed endotracheal suction in high-frequency ventilated premature infants measured with electrical impedance tomography

    NARCIS (Netherlands)

    M.B. van Veenendaal; M. Miedema; F.H.C. de Jongh; J.H. van der Lee; I. Frerichs; A.H. van Kaam

    2009-01-01

    Objective: To determine the global and regional changes in lung volume during and after closed endotracheal tube (ETT) suction in high-frequency ventilated preterm infants with respiratory distress syndrome (RDS). Design: Prospective observational clinical study. Setting: Neonatal intensive care uni

  19. Systematic review and meta-analysis of closed suction drainage versus non-drainage in primary hip arthroplasty.

    LENUS (Irish Health Repository)

    Kelly, Enda G

    2014-03-01

    The routine use of drains in surgery has been dogmatically instituted in some disciplines. Orthopaedic surgery is one such sub-speciality. The use of postoperative closed suction drainage in total hip arthroplasty (THA) has become increasingly controversial with multiple randomised control trials performed to assess the benefit to outcome in THA. The hypothesis of this systematic review is that closed suction drainage does not infer a benefit and increase transfusion requirements of primary total hip arthroplasty patients. A systematic review and meta-analysis was conducted adhering to the PRISMA guidelines. A search of the available literature was performed on PubMed, Cochrane Central Registry of Controlled Trials, MEDLINE (OVID) and EMBASE using a combination of MeSH terms and Boolean operators. All data analysis was performed using the Cochrane Collaboration\\'s Review Manager 5.1. Sixteen studies (n=2705) were included in the analysis. Post-operative closed suction drainage was found to increase total blood loss and blood transfusion requirements (p<0.05). Surgical site infection demonstrated no significant difference between the two groups (p=0.82). No significant difference in haematoma formation between groups (p=0.19) was elicited. The routine use of closed suction drainage systems post primary hip arthroplasty is not supported by this meta-analysis. However, the heterogeneity between studies does limit the accuracy of the meta-analysis.

  20. Severe hypotension related to high negative pressure suction drainage on a thoracic epidural drain during multilevel spinal fixation.

    Science.gov (United States)

    Brahmbhatt, Anjalee; Hall, Nicholas D P; Bradley, William Pierre Litherland

    2013-11-15

    Hypotension or bradycardia or both related to intracranial hypotension after craniotomy has been reported in the literature. However, such reports are uncommon with thoracic epidural drains. We describe a case in which application of high negative pressure suction to a thoracic epidural drain caused a sudden decrease in arterial blood pressure.

  1. No drain, autologous transfusion drain or suction drain? A randomised prospective study in total hip replacement surgery of 168 patients.

    Science.gov (United States)

    Cheung, Graham; Carmont, Michael R; Bing, Andrew J F; Kuiper, Jan-Herman; Alcock, Robert J; Graham, Niall M

    2010-10-01

    We performed a prospective, randomised controlled trial to assess the differences in the use of a conventional suction drain, an Autologous Blood Transfusion (ABT) drain and no drain, in 168 patients. There was no significant difference between the drainage from ABT drains ( mean : 345 ml) and the suction drain (314 ml). Forty percent of patients receiving a suction drain had a haemoglobin level less than 10 g/dL at 24 hours, compared to 35% with no drain and 28% with an ABT drain. Patients that had no drains had wounds that were dry significantly sooner, mean 3.0 days compared to a mean of 3.9 days with an ABT drain and a mean of 4 days with a suction drain. Patients that did not have a drain inserted stayed in hospital a significantly shorter period of time, compared with drains. We feel the benefits of quicker drying wounds, shorter hospital stays and the economic savings justify the conclusion that no drain is required after hip replacement.

  2. Conceptual Design of Portable Filtered Air Suction Systems For Prevention of Released Radioactive Gas under Severe Accidents of NPP

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Beom W.; Choi, Su Y.; Yim, Man S.; Rim, Chun T. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    It becomes evident that severe accidents may occur by unexpected disasters such as tsunami, heavy flood, or terror. Once radioactive material is released from NPP through severe accidents, there are no ways to prevent the released radioactive gas spreading in the air. As a remedy for this problem, the idea on the portable filtered air suction system (PoFASS) for the prevention of released radioactive gas under severe accidents was proposed. In this paper, the conceptual design of a PoFASS focusing on the number of robot fingers and robot arm rods are proposed. In order to design a flexible robot suction nozzle, mathematical models for the gaps which represent the lifted heights of extensible covers for given convex shapes of pipes and for the covered areas are developed. In addition, the system requirements for the design of the robot arms of PoFASS are proposed, which determine the accessible range of leakage points of released radioactive gas. In this paper, the conceptual designs of the flexible robot suction nozzle and robot arm have been conducted. As a result, the minimum number of robot fingers and robot arm rods are defined to be four and three, respectively. For further works, extensible cover designs on the flexible robot suction nozzle and the application of the PoFASS to the inside of NPP should be studied because the radioactive gas may be released from connection pipes between the containment building and auxiliary buildings.

  3. Two-Factor Model of Soil Suction from Capillarity, Shrinkage, Adsorbed Film, and Intra-aggregate Structure

    CERN Document Server

    Chertkov, V Y

    2014-01-01

    The objective of this work is to derive the soil water retention from the soil structure without curve-fitting and only using the physical parameters found irrespective of an experimental retention curve. Two key points underlie the work: (i) the soil suction at drying coincides with that of the soil intra-aggregate matrix and contributive clay; and (ii) both the soil suction and volume shrinkage at drying depend on the same soil water content. In addition the two following results are used: (i) the available two-factor (capillarity and shrinkage) model of clay suction enables one to connect a clay suction and clay water content using the clay matrix structure; and (ii) the recent reference shrinkage curve model based on the concepts of intra-aggregate soil structure permits one to connect the soil water content at shrinkage with the water content of the contributive clay. With that the available two-factor model was essentially modified and, in particular, the effect of adsorbed water film was taken into acc...

  4. A Comparison of delO18 Composition of Water Extracted from Suction Lysimeters, Centrifugation, and Azeotropic Distillation

    Science.gov (United States)

    Figueroa, A.; Tindall, J. A.; Friedel, M. J.

    2005-12-01

    Concentration of delO18 in water samples extracted by suction lysimeters is compared to samples obtained by methods of centrifugation and azeotropic distillation. Intact soil cores (30 cm diameter by 40 cm height) were extracted from two different sites. Site 1 was rapid infiltration basin number 50, near Altamonte Springs in Seminole County, Florida on properties belonging to the Walt Disney World Resort Complex. Site 2 was the Missouri Management System Evaluation Area (MSEA) near Centralia in Boone County, Missouri. The delO18 water was analyzed on a mass spectrophotometer. Potassium Bromide (KBr) was also used as a tracer and analyzed by ion chromatography. A portion of the data obtained was modeled using CXTFIT. Water collected by centrifugation and azeotropic distillation data were about 2-5% more negative than that collected by suction lysimeter values from the Florida (sandy) soil and about 5-7 % more negative from the Missouri (well structured clay) soil. Results indicate that the majority of soil water in well structured soil is strongly bound to soil grain surfaces and is not easily sampled by suction lysimeters. Also, it is plausible that evaporation caused some delO18 enrichment in the suction lysimeters. Suction lysimeters preferentially sampled water held at lower matric potentials, which may not represent total soil water. In cases where a sufficient volume of water has passed through the soil profile and displaced all previous pore water, suction lysimeters will however collect a representative sample of all the water at that depth interval. It is suggested that for stable isotope studies monitoring precipitation and soil water, suction lysimeters be installed at shallow depths (10 cm). Samples should also be coordinated with precipitation events. The CXTFIT program worked well for Florida soils (a more homogeneous sand), but gave poor performance for Missouri soils (well structured clays) except for deeper depths where clay structure was less

  5. Dietary supplements for aquatic sports.

    Science.gov (United States)

    Derave, Wim; Tipton, Kevin D

    2014-08-01

    Many athletes use dietary supplements, with use more prevalent among those competing at the highest level. Supplements are often self-prescribed, and their use is likely to be based on an inadequate understanding of the issues at stake. Supplementation with essential micronutrients may be useful when a diagnosed deficiency cannot be promptly and effectively corrected with food-based dietary solutions. When used in high doses, some supplements may do more harm than good: Iron supplementation, for example, is potentially harmful. There is good evidence from laboratory studies and some evidence from field studies to support health or performance benefits from appropriate use of a few supplements. The available evidence from studies of aquatic sports is small and is often contradictory. Evidence from elite performers is almost entirely absent, but some athletes may benefit from informed use of creatine, caffeine, and buffering agents. Poor quality assurance in some parts of the dietary supplements industry raises concerns about the safety of some products. Some do not contain the active ingredients listed on the label, and some contain toxic substances, including prescription drugs, that can cause health problems. Some supplements contain compounds that will cause an athlete to fail a doping test. Supplement quality assurance programs can reduce, but not entirely eliminate, this risk.

  6. VT Biodiversity Project - Aquatic Sites boundary lines

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) Exemplary aquatic sites in Vermont, both standing water and running water, are represented in this dataset. It is the result of an analysis by the...

  7. Submerged Aquatic Vegetation (SAV) - Volusia County Seagrass

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Aquatic vegetation in Volusia County. DEP SEA_GRASSES This polygon GIS data set represents a compilation of statewide seagrass data from various source agencies and...

  8. Nonindigenous Aquatic Species Database Marine Fishes

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Nonindigenous Aquatic Species Database (NAS) information resource is an established central repository for spatially referenced biogeographic accounts of...

  9. 76 FR 60863 - Aquatic Nuisance Species Task Force Meeting

    Science.gov (United States)

    2011-09-30

    ... include: Commercial harvest of aquatic invasive species, State Aquatic Nuisance Species Management Plans...-Chair, Aquatic Nuisance Species Task Force, Acting Assistant Director--Fisheries and Habitat... Fish and Wildlife Service Aquatic Nuisance Species Task Force Meeting AGENCY: Fish and Wildlife...

  10. Using AquaticHealth.net to Detect Emerging Trends in Aquatic Animal Health

    Directory of Open Access Journals (Sweden)

    Geoff Grossel

    2013-05-01

    Full Text Available AquaticHealth.net is an open-source aquatic biosecurity intelligence application. By combining automated data collection and human analysis, AquaticHealth.net provides fast and accurate disease outbreak detection and forecasts, accompanied with nuanced explanations. The system has been online and open to the public since 1 January 2010, it has over 200 registered expert users around the world, and it typically publishes about seven daily reports and two weekly disease alerts. We document the major trends in aquatic animal health that the system has detected over these two years, and conclude with some forecasts for the future.

  11. Nutrition and training adaptations in aquatic sports.

    Science.gov (United States)

    Mujika, Iñigo; Stellingwerff, Trent; Tipton, Kevin

    2014-08-01

    The adaptive response to training is determined by the combination of the intensity, volume, and frequency of the training. Various periodized approaches to training are used by aquatic sports athletes to achieve performance peaks. Nutritional support to optimize training adaptations should take periodization into consideration; that is, nutrition should also be periodized to optimally support training and facilitate adaptations. Moreover, other aspects of training (e.g., overload training, tapering and detraining) should be considered when making nutrition recommendations for aquatic athletes. There is evidence, albeit not in aquatic sports, that restricting carbohydrate availability may enhance some training adaptations. More research needs to be performed, particularly in aquatic sports, to determine the optimal strategy for periodizing carbohydrate intake to optimize adaptations. Protein nutrition is an important consideration for optimal training adaptations. Factors other than the total amount of daily protein intake should be considered. For instance, the type of protein, timing and pattern of protein intake and the amount of protein ingested at any one time influence the metabolic response to protein ingestion. Body mass and composition are important for aquatic sport athletes in relation to power-to-mass and for aesthetic reasons. Protein may be particularly important for athletes desiring to maintain muscle while losing body mass. Nutritional supplements, such as b-alanine and sodium bicarbonate, may have particular usefulness for aquatic athletes' training adaptation.

  12. Fermented liquid feed for pigs

    OpenAIRE

    Missotten, Joris; Michiels, Joris; Ovyn, Anneke; De Smet, Stefaan; Dierick, Noël

    2010-01-01

    Since the announcement of the ban on the use of antibiotics as antimicrobial growth promoters in the feed of pigs in 2006 the investigation towards alternative feed additives has augmented considerably. Although fermented liquid feed is not an additive, but a feeding strategy, the experimental work examining its possible advantages also saw a rise. The use of fermented liquid feed (FLF) has two main advantages, namely that the simultaneous provision of feed and water may result in an alleviat...

  13. The potential of the fresh-water fern Azolla in aquatic farming systems

    Science.gov (United States)

    Bijl, Peter K.; Werf, vd, Adrie; Schluepmann, Henriette; Reichart, Gert-Jan; Brouwer, Paul; Nierop, Klaas G. J.; Hellgardt, Klaus; Brinkhuis, Henk

    2014-05-01

    With aquatic farming systems a new avenue in agriculture is explored, in which the competition with conventional arable land is avoided. The aquatic, ubiquitous, floating fern Azolla is not yet widely explored as potential crop in such farming systems, despite its high potential because it grows in many natural systems under low-light intensities, has an enormous annual yield, and has special biomass qualities for applications in food, feed and specialty chemical industries. But, what makes Azolla particularly interesting as cost-effective crop is its capability to take up atmospheric nitrogen through symbiosis with nitrogen-fixing bacteria Anabaena azollae. This makes Azolla independent of nitrogen fertilization. In order to explore the potential of Azolla as a crop for a suite of applications, we have assembled a team of expertise: AZOFAST, consisting of agricultural engineers, plant physiologists, chemical engineers and organic chemists. Our growth experiments reveal high annual production yields with constant harvest. We are developing a germination and spore collecting/preservation protocol as a first step to domestication. Finally we have explored the biomass quality of different species of extant Azolla. We performed organic chemical analyses on lipid and tannin extracts, and quantified yields of specific compounds within these fractions. In our presentation we will present some of our results to show the potential of Azolla as a new, sustainable aquatic crop serving all kinds of industrial streams from protein feed to platform chemicals.

  14. Suction/inspiration against resistance or standardized Mueller maneuver: a new breathing technique to improve contrast density within the pulmonary artery: a pilot CT study

    Energy Technology Data Exchange (ETDEWEB)

    Gutzeit, Andreas [Paracelsus Medical University Salzburg, Department of Radiology, Salzburg (Austria); Hirslanden Hospital St. Anna, Institute of Radiology and Nuclear Medicine, Clinical Research Unit, Lucerne (Switzerland); Kantonsspital Winterthur, Department of Radiology, Winterthur (Switzerland); Froehlich, Johannes M.; Weymarn, Constantin von; Goyen, Matthias [Hirslanden Hospital St. Anna, Institute of Radiology and Nuclear Medicine, Clinical Research Unit, Lucerne (Switzerland); Waelti, Stephan [Cantonal Hospital St. Gallen, Department of Radiology and Nuclear Medicine, St. Gallen (Switzerland); Roos, Justus E. [Duke University Medical Center, Department of Radiology, Durham, NC (United States); Meissnitzer, Matthias; Hergan, Klaus [Paracelsus Medical University Salzburg, Department of Radiology, Salzburg (Austria); Czell, David [Cantonal Hospital Winterthur, Department of Neurology, Winterthur (Switzerland); Reischauer, Carolin [Paracelsus Medical University Salzburg, Department of Radiology, Salzburg (Austria); Hirslanden Hospital St. Anna, Institute of Radiology and Nuclear Medicine, Clinical Research Unit, Lucerne (Switzerland)

    2015-11-15

    Our aim was to prospectively investigate whether the recently introduced suction/inspiration against resistance breathing method leads to higher computed tomography (CT) contrast density in the pulmonary artery compared to standard breathing. The present study was approved by the Medical Ethics committee and all subjects gave written informed consent. Fifteen patients, each without suspicious lung emboli, were randomly assigned to four different groups with different breathing maneuvers (suction against resistance, Valsalva, inspiration, expiration) during routine CT. Contrast enhancement in the central and peripheral sections of the pulmonary artery were measured and compared with one another. Peripheral enhancement during suction yielded increased mean densities of 138.14 Hounsfield units (HU) (p = 0.001), compared to Valsalva and a mean density of 67.97 HU superior to inspiration (p = 0.075). Finally, suction in comparison to expiration resulted in a mean increase of 30.51 HU (p = 0.42). Central parts of pulmonary arteries presented significantly increased enhancement values (95.74 HU) for suction versus the Valsalva technique (p = 0.020), while all other mean densities were in favour of suction (versus inspiration: p = 0.201; versus expiration: p = 0.790) without reaching significance. Suction/Inspiration against resistance is a promising technique to improve contrast density within pulmonary vessels, especially in the peripheral parts, in comparison to other breathing maneuvers. (orig.)

  15. Unifying Rules for Aquatic Locomotion

    Science.gov (United States)

    Saadat, Mehdi; Domel, August; di Santo, Valentina; Lauder, George; Haj-Hariri, Hossein

    2016-11-01

    Strouhal number, St (=fA/U) , a scaling parameter that relates speed, U, to the tail-beat frequency, f, and tail-beat amplitude, A, has been used many times to describe animal locomotion. It has been observed that swimming animals cruise at 0.2 experimental evidence of a self-propelled fish-like swimmer, we show that when cruising at minimum hydrodynamic input power, St is predetermined, and is only a function of the shape, i.e. drag coefficient and area. The narrow range for St, 0.2-0.4, has been previously associated with optimal propulsive efficiency. However, St alone is insufficient for deciding optimal motion. We show that hydrodynamic input power (energy usage to propel over a unit distance) in fish locomotion is minimized at all cruising speeds when A* (= A/L), a scaling parameter that relates tail-beat amplitude, A, to the length of the swimmer, L, is constrained to a narrow range of 0.15-0.25. Our analysis proposes a constraint on A*, in addition to the previously found constraint on St, to fully describe the optimal swimming gait for fast swimmers. A survey of kinematics for dolphin, as well as new data for trout, show that the range of St and A* for fast swimmers indeed are constrained to 0.2-0.4 and 0.15-0.25, respectively. Our findings provide physical explanation as to why fast aquatic swimmers cruise with relatively constant tail-beat amplitude at approximately 20 percent of body length, while their swimming speed is linearly correlated with their tail-beat frequency.

  16. Experiences of countries with new aquatic industries: the development of aquaculture in Iran.

    Science.gov (United States)

    Rajaby, M

    2008-04-01

    Although caviar is the most significant and famous fishery product of Iran, in recent years the country has gained a lot of experience and had some significant success with other fishery and aquaculture products. Iranian fisheries and aquaculture production reached 522,000 metric tons in 2005, of which 75% originated from capture fishery and 25% from aquaculture activities. Various fishery and aquaculture activities take place in Iran to help meet domestic demand for aquaculture products and to maintain the existing level of natural resources in seas and rivers (restocking natural sources). The ways in which Iran has been able to make progress in developing aquaculture--which could serve as a model for other countries in the region and for developing countries--are as follows: a) optimising the use of climatic diversity in raising various aquatic species; b) establishing the required governmental and nongovernmental organisations for raising aquatic animals, and planning and creating appropriate relationships between those organisations and entities; c) training skilful manpower and educating specialists in the field of aquatic animal health and diseases; d) increasing per capita consumption of fishery products through sensitising public opinion; and e) meeting the requirements for raising the rate of aquatic animal culture and developing the export of fishery products, i.e. by supplying eyed eggs, feed, broodstock, etc.

  17. Selenium biotransformations in an engineered aquatic ecosystem for bioremediation of agricultural wastewater via brine shrimp production.

    Science.gov (United States)

    Schmidt, Radomir; Tantoyotai, Prapakorn; Fakra, Sirine C; Marcus, Matthew A; Yang, Soo In; Pickering, Ingrid J; Bañuelos, Gary S; Hristova, Krassimira R; Freeman, John L

    2013-05-21

    An engineered aquatic ecosystem was specifically designed to bioremediate selenium (Se), occurring as oxidized inorganic selenate from hypersalinized agricultural drainage water while producing brine shrimp enriched in organic Se and omega-3 and omega-6 fatty acids for use in value added nutraceutical food supplements. Selenate was successfully bioremediated by microalgal metabolism into organic Se (seleno-amino acids) and partially removed via gaseous volatile Se formation. Furthermore, filter-feeding brine shrimp that accumulated this organic Se were removed by net harvest. Thriving in this engineered pond system, brine shrimp ( Artemia franciscana Kellogg) and brine fly (Ephydridae sp.) have major ecological relevance as important food sources for large populations of waterfowl, breeding, and migratory shore birds. This aquatic ecosystem was an ideal model for study because it mimics trophic interactions in a Se polluted wetland. Inorganic selenate in drainage water was metabolized differently in microalgae, bacteria, and diatoms where it was accumulated and reduced into various inorganic forms (selenite, selenide, or elemental Se) or partially incorporated into organic Se mainly as selenomethionine. Brine shrimp and brine fly larva then bioaccumulated Se from ingesting aquatic microorganisms and further metabolized Se predominately into organic Se forms. Importantly, adult brine flies, which hatched from aquatic larva, bioaccumulated the highest Se concentrations of all organisms tested.

  18. Magnetohydrodynamics effect on three-dimensional viscous incompressible flow between two horizontal parallel porous plates and heat transfer with periodic injection/suction

    Directory of Open Access Journals (Sweden)

    R. C. Chaudhary

    2004-11-01

    Full Text Available We investigate the hydromagnetic effect on viscous incompressible flow between two horizontal parallel porous flat plates with transverse sinusoidal injection of the fluid at the stationary plate and its corresponding removal by periodic suction through the plate in uniform motion. The flow becomes three dimensional due to this injection/suction velocity. Approximate solutions are obtained for the flow field, the pressure, the skin-friction, the temperature field, and the rate of heat transfer. The dependence of solution on M (Hartmann number and λ (injection/suction is investigated by the graphs and tables.

  19. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed....

  20. How Doth the Little Crocodilian: Analyzing the Influence of Environmental Viscosity on Feeding Performance of Juvenile Alligator mississippiensis.

    Science.gov (United States)

    Kerfoot, James R; Easter, Emily; Elsey, Ruth M

    2016-09-30

    Wetland habitats are used as nursery sites for hatchling and juvenile alligators (Alligator mississippiensis), where they utilize prey from aquatic and terrestrial settings. However, little is known about how viscosity of the medium influences feeding performance. We hypothesized that timing and linear excursion feeding kinematic variables would be different for individuals feeding on prey above the water compared with the same individuals feeding underwater. Individuals were fed immobile fish prey and feeding events were recorded using a high speed video camera. Feeding performance was summarized by analyzing three feeding kinematic variables (maximum gape, maximum gape velocity, duration of feeding bout) and success of strike. Results of a series of paired t-tests indicated no significant difference in kinematic variables between feeding events above water compared with underwater. Similarity in feeding performance could indicate that prey-capture is not altered by environmental viscosity or that feeding behavior can mitigate its influence. Behavioral differences were observed during feeding events with alligators approaching underwater prey having their mouths partially opened versus fully closed when feeding above water. This behavior could be an indication of a strategy used to overcome water viscosity.

  1. How Doth the Little Crocodilian: Analyzing the Influence of Environmental Viscosity on Feeding Performance of Juvenile Alligator mississippiensis

    Directory of Open Access Journals (Sweden)

    James R. Kerfoot

    2016-09-01

    Full Text Available Wetland habitats are used as nursery sites for hatchling and juvenile alligators (Alligator mississippiensis, where they utilize prey from aquatic and terrestrial settings. However, little is known about how viscosity of the medium influences feeding performance. We hypothesized that timing and linear excursion feeding kinematic variables would be different for individuals feeding on prey above the water compared with the same individuals feeding underwater. Individuals were fed immobile fish prey and feeding events were recorded using a high speed video camera. Feeding performance was summarized by analyzing three feeding kinematic variables (maximum gape, maximum gape velocity, duration of feeding bout and success of strike. Results of a series of paired t-tests indicated no significant difference in kinematic variables between feeding events above water compared with underwater. Similarity in feeding performance could indicate that prey-capture is not altered by environmental viscosity or that feeding behavior can mitigate its influence. Behavioral differences were observed during feeding events with alligators approaching underwater prey having their mouths partially opened versus fully closed when feeding above water. This behavior could be an indication of a strategy used to overcome water viscosity.

  2. MHD flow of nanofluids over an exponentially stretching sheet embedded in a stratified medium with suction and radiation effects

    Directory of Open Access Journals (Sweden)

    Loganathan Parasuraman

    2015-01-01

    Full Text Available An analysis has been carried out to investigate the influence of combined effects of MHD, suction and radiation on forced convection boundary layer flow of a nanofluid over an exponentially stretching sheet, embedded in a thermally stratified medium. The governing boundary layer equations of the problem are formulated and transformed into ordinary differential equations, using a similarity transformation. The resulting ordinary differential equations are solved numerically, by the shooting method. The effects of the governing parameters on the flow and heat transfer characteristics are studied and discussed in detail. Different types of nanoparticles, namely, Cu, Ag, Al2O3 and TiO2, with water as the base fluid, are studied. It is found that the effects of the radiation parameter, volume fraction and suction are same on the temperature profiles, in contrast to the effects of the thermal stratification. Comparisons with previously published works are performed in some special cases, and found to be in good agreement.

  3. Mass Transfer Effects on Unsteady Free Convective Flow Past an Infinite, Vertical Porous Plate with Variable Suction

    Directory of Open Access Journals (Sweden)

    C.V. Ramana Kumari

    1995-10-01

    Full Text Available A two-dimensional unsteady flow of a viscous incompressible dissipative fluid past an infinite, vertical porous plate with variable suction, is studied. Approximate solutions to the coupled non linear equations governing the flow are derived and expressions for the fluctuating parts of the velocity, the transient velocity, temperature and concentration, the amplitude and the phase of the skin-friction, and the rate of heat transfer, are derived. The effects of w(Omega(frequency, Gr (Grashof number, Gc (modified Grashof number, Sc (Schmidt number, P (Prandtl number and A (variable suction parameter, on the above physical quantities are calculated numerically and presented in figures and table. Problems of this nature find place in ablative cooling, transpiration and film cooling of rocket and jet engines.

  4. Tumescent suction curettage vs. curettage only for treatment of axillary hyperhidrosis evaluated by subjective and new objective methods.

    Science.gov (United States)

    Tronstad, Christian; Helsing, Per; Tønseth, Kim Alexander; Grimnes, Sverre; Krogstad, Anne Lene

    2014-03-01

    The main purpose of this study was to compare the effect of the 2 minimally invasive surgical techniques for treating axillary hyperhidrosis: superficial tumescent suction curettage and curettage only. A total of 22 patients diagnosed with axillary hyperhidrosis received one type of treatment at each side, randomized. Examinations were performed pre-operatively and at 3, 6 and 12 months following treatment. Sweating was measured by gravimetry and a new skin conductance method. Subjective rating of sweating was assessed by a visual analogue scale. Skin conductance was recorded during a stress-test including acoustic, mental and physical stressors. Five patients withdrew or did not meet for any follow-up examination, giving 17 subjects in total for data analysis. Significant reduction in sweating after surgery lasting at least 12 months was found based on skin conductance, gravimetry and visual analogue scale scoring. Comparison between types of treatment revealed a significantly better effect of tumescent suction curettage than curettage only.

  5. Trait modality distribution of aquatic macrofauna communities as explained by pesticides and water chemistry.

    Science.gov (United States)

    Ieromina, O; Musters, C J M; Bodegom, P M; Peijnenburg, W J G M; Vijver, M G

    2016-08-01

    Analyzing functional species' characteristics (species traits) that represent physiological, life history and morphological characteristics of species help understanding the impacts of various stressors on aquatic communities at field conditions. This research aimed to study the combined effects of pesticides and other environmental factors (temperature, dissolved oxygen, dissolved organic carbon, floating macrophytes cover, phosphate, nitrite, and nitrate) on the trait modality distribution of aquatic macrofauna communities. To this purpose, a field inventory was performed in a flower bulb growing area of the Netherlands with significant variation in pesticides pressures. Macrofauna community composition, water chemistry parameters and pesticide concentrations in ditches next to flower bulb fields were determined. Trait modalities of nine traits (feeding mode, respiration mode, locomotion type, resistance form, reproduction mode, life stage, voltinism, saprobity, maximum body size) likely to indicate pesticides impacts were analyzed. According to a redundancy analysis, phosphate -and not pesticides- constituted the main factor structuring the trait modality distribution of aquatic macrofauna. The functional composition could be ascribed for 2-4 % to pesticides, and for 3-11 % to phosphate. The lack of trait responses to pesticides may indicate that species may have used alternative strategies to adapt to ambient pesticides stress. Biomass of animals exhibiting trait modalities related to feeding by predation and grazing, presence of diapause form or dormancy, reproduction by free clutches and ovoviviparity, life stage of larvae and pupa, was negatively correlated to the concentration of phosphate. Hence, despite the high pesticide pollution in the area, variation in nutrient-related stressors seems to be the dominant driver of the functional composition of aquatic macrofauna assembly in agricultural ditches.

  6. Enteral feeding without pancreatic stimulation

    DEFF Research Database (Denmark)

    Kaushik, Neeraj; Pietraszewski, Marie; Holst, Jens Juul

    2005-01-01

    OBJECTIVE: All forms of commonly practiced enteral feeding techniques stimulate pancreatic secretion, and only intravenous feeding avoids it. In this study, we explored the possibility of more distal enteral infusions of tube feeds to see whether activation of the ileal brake mechanism can result...... in enteral feeding without pancreatic stimulation, with particular reference to trypsin, because the avoidance of trypsin stimulation may optimize enteral feeding in acute pancreatitis. METHODS: The pancreatic secretory responses to feeding were studied in 36 healthy volunteers by standard double......-lumen duodenal perfusion/aspiration techniques over 6 hours. Subjects were assigned to no feeding (n = 7), duodenal feeding with a polymeric diet (n = 7) or low-fat elemental diet (n = 6), mid-distal jejunal feeding (n = 11), or intravenous feeding (n = 5). All diets provided 40 kcal/kg ideal body weight/d and 1...

  7. Feeding Behavior of Subadult Sixgill Sharks (Hexanchus griseus at a Bait Station.

    Directory of Open Access Journals (Sweden)

    Bryan McNeil

    Full Text Available This is the first in-situ study of feeding behaviors exhibited by bluntnose sixgill sharks. Bait was placed beneath the Seattle Aquarium pier situated on the waterfront in Elliott Bay, Puget Sound, Washington at 20m of water depth. Cameras and lights were placed around the bait box to record sixgill shark presence and behavior while feeding. Analysis of feeding behavior revealed that sixgills utilize a bite comparable to many other elasmobranchs and aquatic vertebrates, have the ability to protrude their upper jaw, change their feeding behavior based on the situation, and employ sawing and lateral tearing during manipulation. The versatility of their feeding mechanism and the ability of sixgills to change their capture and food manipulation behaviors may have contributed to the species' worldwide distribution and evolutionary success.

  8. Study on Air-Aided Transport Means of Cutter-Suction Dredger

    Directory of Open Access Journals (Sweden)

    Ting Xiong

    2013-06-01

    Full Text Available This study proves the effectiveness of air-aided transport in reducing pipeline resistance and lengthening transport distance. The adopted experimental apparatus is unique in its chosen pipes (120 mm, transmission mediums (including clean water and slurries concentrated at 10, 20 and 30%, respectively and experiment comparisons between air-aided transport and traditional relay pump transport. Factors such as resistance, transport distance and energy consumption are compared through the data from laboratory experiments, thus proving the evident advantages from air-aided transport. The total energy consumption in air-aided transport is less than that of relay pump, especially within its resistance reducing scope, where slurry flow ranges from 65m3/h to 90 m3/h. It also exists within resistance reducing scope where slurry flow of air-aided transport is less than that of relay pump transport and may reach its limited effective distance. Thus, the findings of this study can provide valuable insight for the optimization design of air-aided transport of cutter-suction dredger.

  9. Experimental Study of Pore Pressure and Deformation of Suction Bucket Foundations Under Horizontal Dynamic Loading

    Institute of Scientific and Technical Information of China (English)

    LU Xiao-bing; WANG Shu-yun; ZHANG Jian-hong; SUN Guo-liang; SHI Zhong-min

    2005-01-01

    Centrifuge experiments are carried out to investigate the responses of suction bucket foundations under horizontal dynamic loading. The effects of loading amplitude, the size of the bucket and the structural weight on the dynamic responses are investigated. It is shown that, when the loading amplitude is over a critical value, the sand at the upper part around the bucket softens or even liquefies. The liquefaction index (excess pore pressure divided by initial effective stress. In this paper, the developmental degree of excess pore pressure is described by liquefaction index) decreases from the upper part to the lower part of the sand foundation in the vertical direction and decreases from near to far away from the bucket′s side wall in the horizontal direction. Large settlements of the bucket and the sand around the bucket are induced by the horizontal dynamic loading. The dynamic responses of the bucket of a smaller height (when the diameter is the same) are heavier. A cyclic crack some distance near the bucket occurs in the sand.

  10. Coma from wall suction-induced CSF leak complicating spinal surgery.

    Science.gov (United States)

    Fehnel, Corey R; Razmara, Ali; Feske, Steven K

    2014-03-12

    A 72-year-old woman was admitted for elective L4/L5 laminectomy. The operative procedure was extradural, and a Jackson-Pratt (JP) drain was placed in the tissue bed and set to wall suction during skin closure. During closure, the patient developed a 15 s period of asystole. The patient was haemodynamically stable, but was comatose for 3 days postoperatively. Cardiac enzymes and EEG were unrevealing. Head CT showed traces of subarachnoid haemorrhage and signs suggestive of cerebral anoxia. JP drain at the incision produced 170-210 mL/day of fluid, positive for β-2 transferrin, indicating cerebrospinal fluid (CSF). The patient fully returned to baseline on hospital day 10. MRI on hospital day 8 normalised. The reversible coma and radiographic findings were most consistent with acute intracranial hypotension relating to acute loss of CSF. Because radiographic findings can mimic hypoxic-ischaemic injury, acute intracranial hypotension should be considered in the differential diagnosis of postoperative coma after cranial or spinal surgery.

  11. Composite Behavior of Insulated Concrete Sandwich Wall Panels Subjected to Wind Pressure and Suction

    Directory of Open Access Journals (Sweden)

    Insub Choi

    2015-03-01

    Full Text Available A full-scale experimental test was conducted to analyze the composite behavior of insulated concrete sandwich wall panels (ICSWPs subjected to wind pressure and suction. The experimental program was composed of three groups of ICSWP specimens, each with a different type of insulation and number of glass-fiber-reinforced polymer (GFRP shear grids. The degree of composite action of each specimen was analyzed according to the load direction, type of the insulation, and number of GFRP shear grids by comparing the theoretical and experimental values. The failure modes of the ICSWPs were compared to investigate the effect of bonds according to the load direction and type of insulation. Bonds based on insulation absorptiveness were effective to result in the composite behavior of ICSWP under positive loading tests only, while bonds based on insulation surface roughness were effective under both positive and negative loading tests. Therefore, the composite behavior based on surface roughness can be applied to the calculation of the design strength of ICSWPs with continuous GFRP shear connectors.

  12. Equilibrium turbulent boundary layers with wall suction/blowing and pressure gradients

    Science.gov (United States)

    Patwardhan, Saurabh; Ramesh, O. N.

    2012-11-01

    Conditions for the equilibrium conditions in turbulent boundary layers with suction or blowing across a no slip wall and pressure gradients are derived from the governing equations. It is also shown that under these conditions the governing equations show self similarity in the conventional inner co-ordinates as well as ``laminar-like'' co-ordinates. The only turbulent boundary layer in ``perfect equilibrium'' known as sink flow turbulent boundary layer forms a subset of this more general equilibrium concept. Direct numerical simulations were carried out to investigate this hypothesis for the case of favourable pressure gradient with small blowing at the wall. Reynolds number invariance and complete self similarity of mean velocity profile and second order turbulence statistics is observed along the flow direction similar to the sink flow boundary layer. A comparison between the case with wall blowing and imposed favourable pressure gradient and the sink flow case for same value of pressure gradient parameter reveals a shift in log law in mean velocity profile and increase in peak turbulence intensities.

  13. Thermodynamic analysis of a refrigeration cycle using regenerative heat exchanger - suction/liquid line

    Energy Technology Data Exchange (ETDEWEB)

    Tebchirani, Tarik Linhares; Matos, Rudmar Serafim [Pos graduate Programme in Mechanical Engineering (PGMEC), Universidade Federal do Parana, Curitiba, PR (Brazil)], e-mails: tarik@utfpr.edu.br, rudmar@demec.ufpr.br

    2010-07-01

    This paper presents results from thermodynamic comparison of a conventional compression cycle and a steam cycle that uses a heat exchanger countercurrent (liquid line/suction line) in an air conditioning system split. The main objective is to study the relationship between the COP and the mass variation of refrigerant to the effectiveness of the heat exchanger. The papers presented in the literature discuss the matter in a theoretical way, are summarized in tables of rare loss statements without specification of methods. The methodology of work is based on testing of an air conditioner operating conventionally and also with the heat exchanger for the determination of values and parameters of interest. The tests were performed in a thermal chamber with temperature controlled and equipped with a data acquisition system for reading and storage results. The refrigerant was R22. Besides making possible an assessment of the feasibility of cost-benefit thermodynamics, it is suggested a different method for installing the equipment type split. (author)

  14. Study on particle distribution in A356/SiCp upward suction castings.

    Science.gov (United States)

    Chen, Feifan; Zhao, Haidong; Sun, Fengzhen; Zhao, Yu

    2014-10-01

    In this investigation, cylindrical A356-5%50 μm SiCp and A356-10%100 μm SiCp castings of 40 mm diameter and 350 mm height were produced by stirring preparation and vertically upward suction casting process. The SiCp fractions in the casting different sections along the filling direction were quantitatively measured. The composite slurry flow during the casting mold filling was simulated based on the Euler method while the particle flow was calculated with the Lagrangian method for predicting the SiCp distribution. The simulated distributions were compared and validated with the experiment. It has shown that as the filling distance increased, the particle fractions decreased dramatically in the A356-10%100 μm SiCp casting while varied slightly in the A356-5%50 μm SiCp casting, and that the particles were prone to be aggregated near the mold wall at the filling beginning parts whereas more particles concentrated in the centre and fewer particles were present near the wall region in the casting front.

  15. Investigating soil water retention characteristics at high suctions using relative humidity control

    Directory of Open Access Journals (Sweden)

    Mantikos Vasileios

    2016-01-01

    Full Text Available A technique for controlling relative humidity (RH is presented, which involves supplying a sealed chamber with a continuous flow of air at a computer-regulated RH. The desired value of RH is achieved by mixing dry and wet air at appropriate volumes and is measured for servo-control at three locations in the chamber with capacitive RH sensors and checked with a sensitive VAISALA sensor. The setup is capable of controlling RH steadily and continuously with a deviation of less than 0.2% RH. The technique was adopted to determine wetting soil-water retention curves (SWRC of statically compacted London Clay, under both free-swelling and constant volume conditions. The RH within the chamber was increased in a step-wise fashion, with each step maintained until vapour equilibrium between the chamber atmosphere and the soil samples was established. Independent filter paper measurements further validate the method, while the obtained retention curves complement those available in the literature for lower ranges of suction.

  16. Suction energy and offset configuration for double-walled carbon nanotubes

    Science.gov (United States)

    Baowan, Duangkamon; Thamwattana, Ngamta; Hill, James M.

    2008-09-01

    Nanostructures such as carbon nanotubes and fullerenes offer the means to create new mechanical devices operating at the nanoscale. Such devices include oscillators constructed from an inner carbon nanotube sliding inside another carbon nanotube. The resultant oscillatory frequency is found to be in the gigahertz range and they have applications in the computing industry for signalling devices, such as an ultra-fast optical filter. While most research in the area is dominated by molecular dynamics simulations, our approach here is to use elementary mechanical principles and classical applied mathematical modelling techniques to formulate explicit analytical criteria and ideal model behaviour. In this paper, we first investigate the suction force experienced by a single-walled carbon nanotube located near an open end of a semi-infinite single-walled carbon nanotube, using the Lennard-Jones potential and the continuum approximation. Second the equilibrium position of an offset inner tube with reference to the cross-section of the outer tube is determined.

  17. Edge states for the turbulence transition in the asymptotic suction boundary layer

    CERN Document Server

    Kreilos, Tobias; Schneider, Tobias M; Eckhardt, Bruno

    2013-01-01

    We demonstrate the existence of an exact invariant solution to the Navier-Stokes equations for the asymptotic suction boundary layer. The identified periodic orbit with a very long period of several thousand advective time units is found as a local dynamical attractor embedded in the stability boundary between laminar and turbulent dynamics. Its dynamics captures both the interplay of downstream oriented vortex pairs and streaks observed in numerous shear flows as well as the energetic bursting that is characteristic for boundary layers. By embedding the flow into a family of flows that interpolates between plane Couette flow and the boundary layer we demonstrate that the periodic orbit emerges in a saddle-node infinite-period (SNIPER) bifurcation of two symmetry-related travelling wave solutions of plane Couette flow. Physically, the long period is due to a slow streak instability which leads to a violent breakup of a streak associated with the bursting and the reformation of the streak at a different spanwi...

  18. Unusual Solidification Behavior of the Suction-Cast Cu-Zr-Al-Y Alloy Doped with Fe

    Science.gov (United States)

    Kozieł, Tomasz; Cios, Grzegorz; Latuch, Jerzy; Pajor, Krzysztof; Bała, Piotr

    2017-04-01

    The effect of iron addition on the microstructure of the Cu-Zr-Al-Y glass-forming alloy was studied. Despite a high superficial cooling rate, small Fe additions (1.5 and 3 pct) induced formation of crystalline CuZr and AlCu2Zr phases on the outer layers of suction-cast rods. As the melt composition near the solid/liquid interface was depleted in Fe, the remaining melt vitrified at a relatively low cooling rate.

  19. Aquatic exercise & balneotherapy in musculoskeletal conditions.

    Science.gov (United States)

    Verhagen, Arianne P; Cardoso, Jefferson R; Bierma-Zeinstra, Sita M A

    2012-06-01

    This is a best-evidence synthesis providing an evidence-based summary on the effectiveness of aquatic exercises and balneotherapy in the treatment of musculoskeletal conditions. The most prevalent musculoskeletal conditions addressed in this review include: low back pain, osteoarthritis, fibromyalgia and rheumatoid arthritis. Over 30 years of research demonstrates that exercises in general, and specifically aquatic exercises, are beneficial for reducing pain and disability in many musculoskeletal conditions demonstrating small to moderate effect sizes ranging between 0.19 and 0.32. Balneotherapy might be beneficial, but the evidence is yet insufficient to make a definitive statement about its use. High-quality trials are needed on balneotherapy and aquatic exercises research especially in specific patient categories that might benefit most.

  20. Endocrine disruption in aquatic insects: a review.

    Science.gov (United States)

    Soin, Thomas; Smagghe, Guy

    2007-02-01

    There is mounting evidence that a wide variety of compounds can have endocrine disrupting effects on humans and wildlife. However, investigations so far have focused primarily on exposure to human and other vertebrates, with invertebrate findings largely restricted to marine mollusks or to the ecdysteroid and juvenile hormone agonists as purposely synthesized endocrine disrupters for the pest management of insects. This article provides a brief description of the insect hormone system, a short sum-up of the relevant insect groups with aquatic life stages, and an overview of the additional evidence for endocrine disruption in aquatic insects from laboratory and field studies since 1999. In addition, the suitability of insects as sentinels for endocrine disrupting chemicals in aquatic ecosystems is discussed. Conclusions are drawn and research needs are defined.

  1. Nutrition, illness, and injury in aquatic sports.

    Science.gov (United States)

    Pyne, David B; Verhagen, Evert A; Mountjoy, Margo

    2014-08-01

    In this review, we outline key principles for prevention of injury and illness in aquatic sports, detail the epidemiology of injury and illness in aquatic athletes at major international competitions and in training, and examine the relevant scientific evidence on nutrients for reducing the risk of illness and injury. Aquatic athletes are encouraged to consume a well-planned diet with sufficient calories, macronutrients (particularly carbohydrate and protein), and micronutrients (particularly iron, zinc, and vitamins A, D, E, B6, and B12) to maintain health and performance. Ingesting carbohydrate via sports drinks, gels, or sports foods during prolonged training sessions is beneficial in maintaining energy availability. Studies of foods or supplements containing plant polyphenols and selected strains of probiotic species are promising, but further research is required. In terms of injury, intake of vitamin D, protein, and total caloric intake, in combination with treatment and resistance training, promotes recovery back to full health and training.

  2. Estimation of Heights of Soil Plug Inside Bucket Foundations During Suction Penetration by Deformable Discrete Element Modeling

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The soil plug phenomenon involving the rising of the surface soil inside the bucket chamber under the suction pressure and seepage forces was simulated and calculated by deformable discrete element method (DDEM) models. The seepage forces, the effective gravity of soil, the friction on the chamber wall and the suction inside the chamber are considered as the main external forces of DDEM specimen. Three typical types of soil (silty clay, silt and sand) in the Bohai Sea are set as the main environmental conditions in the formation process of soil plug. It is found that the heights of soil plug simulated by DDEM models are 161.85 mm in silty clay, 125.22 mm in silt and 167.56 mm in sand, which are close to model test results and higher than those estimated by discrete element method (DEM). DDEM is an effective method to estimate and predict the heights of soil plug before suction penetration of bucket foundations on site.

  3. Treatment of herniated lumbar disc by percutaneous laser disc decompression combined with synchronous suction technique through syringe

    Institute of Scientific and Technical Information of China (English)

    Dhir B. Gurung; Gaojian Tao; Hongyi Lin; Yanning Qian; Jian Lin

    2007-01-01

    Objective: To compare the outcomes of percutaneous laser disc decompression (PLDD) and PLDD with synchronous suction through syringe in the patients with herniated lumbar disc (HLD). Methods: Forty-two patients with HLD on MRI and those who did not respond to conservative treatment for 6 weeks were randomly divided into group A and group B. In group A, the patients were treated with PLDD and those in group B with PLDD and synchronous suction through syringe. GaAIAS diode laser at 810 nm was used for the ablation in both groups. The treatment effect was evaluated by modified MacNab's criteria on the 7th, 30th and 90th day. Results: Evaluated by modified MacNab's criteria, the percentages of the excellent and good cases in total patients treated for group B and A were 80.95% and 57.14% on the 7th follow-up day, 85.71% and 66.67% on the 30th follow-up day, and 95.24% and 71.43% on the 90th follow-up day, respectively. Conclusion: Synchronous suction technique through syringe during PLDD improves the overall outcome in the treatment of herniated lumbar disc.

  4. Approximate Analysis of MHD Squeeze Flow between Two Parallel Disks with Suction or Injection by Homotopy Perturbation Method

    Directory of Open Access Journals (Sweden)

    G. Domairry

    2009-01-01

    Full Text Available An analysis has been performed to study magneto-hydrodynamic (MHD squeeze flow between two parallel infinite disks where one disk is impermeable and the other is porous with either suction or injection of the fluid. We investigate the combined effect of inertia, electromagnetic forces, and suction or injection. With the introduction of a similarity transformation, the continuity and momentum equations governing the squeeze flow are reduced to a single, nonlinear, ordinary differential equation. An approximate solution of the equation subject to the appropriate boundary conditions is derived using the homotopy perturbation method (HPM and compared with the direct numerical solution (NS. Results showing the effect of squeeze Reynolds number, Hartmann number and the suction/injection parameter on the axial and radial velocity distributions are presented and discussed. The approximate solution is found to be highly accurate for the ranges of parameters investigated. Because of its simplicity, versatility and high accuracy, the method can be applied to study linear and nonlinear boundary value problems arising in other engineering applications.

  5. Diagnostic Value of Endometrial Sampling with Pipelle Suction Curettage for Identifying Endometrial Lesions in Patients with Abnormal Uterine Bleeding

    Directory of Open Access Journals (Sweden)

    F Behnamfar

    2004-06-01

    Full Text Available Background: While determining the cause of abnormal uterine bleeding, sampling from the endometrium is necessary. Considering that pipelle suction curettage can be performed on an out patient basis and does not require hospitalization, using anesthesia and cervical dilatation, we performed this study. The aim of this study was to compare the diagnostic value of dilatation and curettage (D&C with pipelle suction curettage. Methods: This study was quasiexperimental on 200 pre and postmenopausal patients with abnormal uterine bleeding who refered to Shabihkhani hospital in Kashan, Iran. Endometrial sampling was performed in all patients with two methods namely pipelle and D&C. A pathologist examined the samples each having a predetermined code. Results: The mean age of subjects was 46.2 ±6.2 years, minimum age was 35 years and the maximum was 70 years. The various pathological lab findings were proliferative endometrium, secretory endometrium, athrophic, decidua, cystic and adenomatous hyperplasia. The reports were the same in two methods except for 2 cases where they were different: secretory endometrium with D&C but cystic hyperplasia in pipelle method. Conclusions: The result of our study shows the comparability of obtaining endometrial sample by pipelle with D&C. Due to comfort and convenience of patients in pipelle methode especially in the office setting which does not need anesthesia, pipelle method can easily be employed instead of D&C. Keywords: Pipelle Suction Curette, Dilatation and Curettage, Premenopause, Postmenopause.

  6. Drag Force of Non-newtonian Fluid on a Continuous Moving Surface with Strong Suction/Blowing

    Institute of Scientific and Technical Information of China (English)

    郑连存; 张欣欣; 赫冀成

    2003-01-01

    A theoretical analysis for the laminar boundary layer flow of a non-Newtonian fluid on a continuous moving flat plate with surface strong suction/blowing is made. The types of potential flows necessary for similar solutions to the boundary layer are determined and both analytical and numerical solutions are presented. It is shown that the solution of the boundary layer problem depends not only on the ratio of the velocity of the plate to the velocity of the free stream, but also on the suction/blowing parameter. The skin friction decreases with increasing the parameters of power law and blowing. In the case of existing suction, the shear force decreases with the increases of tangential velocity, the largest shear force occurs at wall and the smallest shear force occurs at the edge of the boundary layer. However, in the case of existing surface blowing, the shear force initially increases with tangentialvelocity and the biggest shear force occurs at the interior of the boundary layer, the skin friction approaches to zero as the blowing rate approaches the critical value.

  7. Systematic review and meta-analysis of closed suction drainage versus non-drainage in primary hip arthroplasty.

    Science.gov (United States)

    Kelly, Enda G; Cashman, James P; Imran, Farrah H; Conroy, Ronán; O'Byrne, John

    2014-03-01

    The routine use of drains in surgery has been dogmatically instituted in some disciplines. Orthopaedic surgery is one such sub-speciality. The use of postoperative closed suction drainage in total hip arthroplasty (THA) has become increasingly controversial with multiple randomised control trials performed to assess the benefit to outcome in THA. The hypothesis of this systematic review is that closed suction drainage does not infer a benefit and increase transfusion requirements of primary total hip arthroplasty patients. A systematic review and meta-analysis was conducted adhering to the PRISMA guidelines. A search of the available literature was performed on PubMed, Cochrane Central Registry of Controlled Trials, MEDLINE (OVID) and EMBASE using a combination of MeSH terms and Boolean operators. All data analysis was performed using the Cochrane Collaboration's Review Manager 5.1. Sixteen studies (n=2705) were included in the analysis. Post-operative closed suction drainage was found to increase total blood loss and blood transfusion requirements (psuction drainage systems post primary hip arthroplasty is not supported by this meta-analysis. However, the heterogeneity between studies does limit the accuracy of the meta-analysis.

  8. Viscous Flows Driven by Uniform Shear over a Porous Stretching Sheet in the Presence of Suction/Blowing

    Directory of Open Access Journals (Sweden)

    Samir Kumar Nandy

    2014-01-01

    Full Text Available An analysis is carried out to study the steady two-dimensional flow of an incompressible viscous fluid past a porous deformable sheet, which is stretched in its own plane with a velocity proportional to the distance from the fixed point subject to uniform suction or blowing. A uniform shear flow of strain rate β is considered over the stretching sheet. The analysis of the result obtained shows that the magnitude of the wall shear stress increases with the increase of suction velocity and decreases with the increase of blowing velocity and this effect is more pronounced for suction than blowing. It is seen that the horizontal velocity component (at a fixed streamwise position along the plate increases with the increase in the ratio of shear rate β and stretching rate (c (i.e., β/c and there is an indication of flow reversal. It is also observed that this flow reversal region increases with the increase in β/c.

  9. Estimation of the Variation of Matric Suction with Respect to Depth in a Vertical Unsaturated Soil Trench Associated with Rainfall Infiltration

    OpenAIRE

    Oh Won Taek; Vanapalli Sai K.; Qi Shunchao; Han Zhong

    2016-01-01

    Soil trenching is extensively used in geotechnical, mining, tunneling and geo-environmental infrastructures. Safe height and stand-up time are two key factors that are required for the rational design of soil trenches. Rainfall infiltration has a significant influence on the safe height and stand-up time of unsaturated soil trenches since it can significantly alter the shear strength of soils by influencing the matric suction. In other words, predicting the variation of matric suction of soil...

  10. Aquatic macroinvertebrates of the Jablanica river, Serbia

    Directory of Open Access Journals (Sweden)

    Stefanović Katarina S.

    2009-01-01

    Full Text Available Research on the community of aquatic macroinvertebrates was carried out during 2005 and 2006 at four sampling sites along the Jablanica River, a right-hand tributary of the Kolubara River. Fifty-seven taxa were recorded in the course of the investigation. The most diverse group was Ephemeroptera, followed by Trichoptera and Plecoptera. Members of the Rhitrogena semicolorata group were the most abundant. Our results could be the basis for evaluation of the influence of damming of the Jablanica River on the status of its water and can serve as a model for studying the influ­ence of hydromorphological degradation of aquatic ecosystems.

  11. Microbial ecology of Antarctic aquatic systems.

    Science.gov (United States)

    Cavicchioli, Ricardo

    2015-11-01

    The Earth's biosphere is dominated by cold environments, and the cold biosphere is dominated by microorganisms. Microorganisms in cold Southern Ocean waters are recognized for having crucial roles in global biogeochemical cycles, including carbon sequestration, whereas microorganisms in other Antarctic aquatic biomes are not as well understood. In this Review, I consider what has been learned about Antarctic aquatic microbial ecology from 'omic' studies. I assess the factors that shape the biogeography of Antarctic microorganisms, reflect on some of the unusual biogeochemical cycles that they are associated with and discuss the important roles that viruses have in controlling ecosystem function.

  12. Global meta-analysis of native and nonindigenous trophic traits in aquatic ecosystems.

    Science.gov (United States)

    McKnight, Ella; García-Berthou, Emili; Srean, Pao; Rius, Marc

    2016-10-26

    Ecologists have recently devoted their attention to the study of species traits and their role in the establishment and spread of nonindigenous species (NIS). However, research efforts have mostly focused on studies of terrestrial taxa, with lesser attention being dedicated to aquatic species. Aquatic habitats comprise of interconnected waterways, as well as exclusive introduction vectors that allow unparalleled artificial transport of species and their propagules. Consequently, species traits that commonly facilitate biological invasions in terrestrial systems may not be as represented in aquatic environments. We provide a global meta-analysis of studies conducted in both marine and freshwater habitats. We selected studies that conducted experiments with native and NIS under common environmental conditions to allow detailed comparisons among species traits. In addition, we explored whether different factors such as species relatedness, functional feeding groups, latitude, climate, and experimental conditions could be linked to predictive traits. Our results show that species with traits that enhance consumption and growth have a substantially increased probability of establishing and spreading when entering novel ecosystems. Moreover, traits associated with predatory avoidance were more prevalent in NIS and therefore favour invasive species in aquatic habitats. When we analysed NIS interacting with taxonomically distinctive native taxa, we found that consumption and growth were particularly important traits. This suggests that particular attention should be paid to newly introduced species for which there are no close relatives in the local biota. Finally, we found a bias towards studies conducted in temperate regions, and thus, more studies in other climatic regions are needed. We conclude that studies aiming at predicting future range shifts should consider trophic traits of aquatic NIS as these traits are indicative of multiple interacting mechanisms involved

  13. Representing infant feeding: content analysis of British media portrayals of bottle feeding and breast feeding

    OpenAIRE

    Henderson, L.; KITZINGER, Jenny; Green, J.

    2001-01-01

    Objective: To examine how breast feeding and bottle feeding are represented by the British media.\\ud Design: Content analysis.\\ud Subjects: Television programmes and newspaper articles that made reference to infant feeding during March 1999.\\ud Setting: UK mass media.\\ud Main outcome measures: Visual and verbal references to breast or bottle feeding in newspapers and television programmes.\\ud Results: Overall, 235 references to infant feeding were identified in the television sample and 38 in...

  14. The role of "the aquatic" in human evolution: constraining the aquatic ape hypothesis.

    Science.gov (United States)

    Foley, Robert; Lahr, Marta Mirazón

    2014-01-01

    Few things show the distinctiveness of human evolution research better than the Aquatic Ape Hypothesis (AAH). On one hand, we have "orthodox" research into human evolution, firmly based on land; on the other, we have the aquatic ape community, convinced not only that our ancestors went through an aquatic phase, but that the professional scientific community ignores their work and keeps it out of the mainstream. How many fields of science have two entirely parallel communities that essentially are hermetically sealed from each other?

  15. Application of vascular aquatic plants for pollution removal, energy and food production in a biological system

    Science.gov (United States)

    Wolverton, B. C.; Barlow, R. M.; Mcdonald, R. C.

    1975-01-01

    Vascular aquatic plants such as water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxeroides) (Mart.) Griesb., when utilized in a controlled biological system (including a regular program of harvesting to achieve maximum growth and pollution removal efficiency), may represent a remarkably efficient and inexpensive filtration and disposal system for toxic materials and sewage released into waters near urban and industrial areas. The harvested and processed plant materials are sources of energy, fertilizer, animal feed, and human food. Such a system has industrial, municipal, and agricultural applications.

  16. Low Emission Feed

    NARCIS (Netherlands)

    Klop, G.

    2016-01-01

    Research into manipulating methane (CH4) production as a result of enteric fermentation in ruminants currently receives global interest. Using feed additives may be a feasible strategy to mitigate CH4 as they are supplied in such amounts that the basal diet composition will not be largely affected.

  17. Feeding of Diarmis Proboscis

    Science.gov (United States)

    Young, Jocelyn

    2005-01-01

    The feeding of Diarmis proboscis is an exciting outdoor laboratory activity that demonstrates a single concept of adaptations--cryptic colorations. The students are "transformed" into D. proboscis (no Harry Potter magic needed) in order to learn how adaptations work in the natural world. Prior to beginning this activity, students should have a…

  18. Feed sources for livestock

    NARCIS (Netherlands)

    Zanten, van H.H.E.

    2016-01-01

    Production of food has re-emerged at the top of the global political agenda, driven by two contemporary challenges: the challenge to produce enough nutritious food to feed a growing and more prosperous human population, and the challenge to produce this food in an environmentally sustainable way. Cu

  19. Differences in ichthyofauna feeding habits among lateral lagoons and the river channel in a large reservoir.

    Science.gov (United States)

    Ferrareze, M; Nogueira, M G; Casatti, L

    2015-05-01

    In this study, we investigated differences in feeding habits of small-sized ichthyofauna among lateral lagoons and the river channel in a large reservoir. The study was performed in four lagoons and in one sampling site of the main channel in Rosana Reservoir, Paranapanema River, Brazil. The samples were taken in September and November of 2004 and in January, March, May, and August of 2005. Fish were sampled with a 7.5 m2 hand net. Five manual throws were made toward aquatic macrophytes stands. The sampling design favored the collection of small-sized fish fauna (juveniles/small-sized species). The stomach contents of 42 species were analyzed. A total of 183 different items were consumed by fish. These items were grouped in 11 food categories, which were used to classify fish into seven trophic guilds. Aquatic insects were consumed by 32 species and were the predominant feeding item. In the river, the most consumed items were aquatic insects, cladocerans, and phytoplankton, whereas in the lagoons aquatic insects, copepods, and cladocerans were the main items. By comparing each trophic guild, the number of insectivores, algivores, and zooplanktivores species was higher in the lagoons than in the river, and the opposite was found only for omnivore fish. Low niche width in all sites indicates high trophic specialization and low niche overlap between pairs of species. Fish assemblage in the lateral lagoons presents feeding habits distinct from those of the river species, indicating that the coexistence and high abundance of small-sized fish in the sampling sites are explained by their high feeding adaptability, which includes a tendency toward dietary specialization, low feeding overlap, and resource partitioning, along with different temporal resource uses.

  20. Differences in ichthyofauna feeding habits among lateral lagoons and the river channel in a large reservoir

    Directory of Open Access Journals (Sweden)

    M. Ferrareze

    Full Text Available In this study, we investigated differences in feeding habits of small-sized ichthyofauna among lateral lagoons and the river channel in a large reservoir. The study was performed in four lagoons and in one sampling site of the main channel in Rosana Reservoir, Paranapanema River, Brazil. The samples were taken in September and November of 2004 and in January, March, May, and August of 2005. Fish were sampled with a 7.5 m2 hand net. Five manual throws were made toward aquatic macrophytes stands. The sampling design favored the collection of small-sized fish fauna (juveniles/small-sized species. The stomach contents of 42 species were analyzed. A total of 183 different items were consumed by fish. These items were grouped in 11 food categories, which were used to classify fish into seven trophic guilds. Aquatic insects were consumed by 32 species and were the predominant feeding item. In the river, the most consumed items were aquatic insects, cladocerans, and phytoplankton, whereas in the lagoons aquatic insects, copepods, and cladocerans were the main items. By comparing each trophic guild, the number of insectivores, algivores, and zooplanktivores species was higher in the lagoons than in the river, and the opposite was found only for omnivore fish. Low niche width in all sites indicates high trophic specialization and low niche overlap between pairs of species. Fish assemblage in the lateral lagoons presents feeding habits distinct from those of the river species, indicating that the coexistence and high abundance of small-sized fish in the sampling sites are explained by their high feeding adaptability, which includes a tendency toward dietary specialization, low feeding overlap, and resource partitioning, along with different temporal resource uses.

  1. Malheur NWR: Initial Survey Instructions for Lacustrine Submergent Aquatic Vegetation

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Submergent aquatic vegetation (SAV) provides the foundation for wildlife use in aquatic systems. Sago pondweed is of particular significance in providing protein by...

  2. Why Care About Aquatic Insects: Uses, Benefits, and Services

    Science.gov (United States)

    Mayflies and other aquatic insects are common subjects of ecological research, and environmental monitoring and assessment. However, their important role in protecting and restoring aquatic ecosystems is often challenged, because their benefits and services to humans are not obv...

  3. Chapter 5. Assessing the Aquatic Hazards of Veterinary Medicines

    Science.gov (United States)

    In recent years, there has been increasing awareness of the widespread distribution of low concentrations of veterinary medicine products and other pharmaceuticals in the aquatic environment. While aquatic hazard for a select group of veterinary medicines has received previous s...

  4. Climate Change and Aquatic Invasive Species (Final Report)

    Science.gov (United States)

    EPA announced the availability of the final report, Climate Change and Aquatic Invasive Species. This report reviews available literature on climate-change effects on aquatic invasive species (AIS) and examines state-level AIS management activities. Data on management ...

  5. Aquatic Habitats: Exploring Desktop Ponds. Teacher's Guide.

    Science.gov (United States)

    Barrett, Katharine; Willard, Carolyn

    This book, for grades 2-6, is designed to provide students with a highly motivating and unique opportunity to investigate an aquatic habitat. Students set up, observe, study, and reflect upon their own "desktop ponds." Accessible plants and small animals used in these activities include Elodea, Tubifex worms, snails, mosquito larvae, and fish.…

  6. Teachers and Aquatic Education--A Survey.

    Science.gov (United States)

    Rakow, Steven J.

    The Minnesota Sea Grant Education Sub-program provided funds to the University of Minnesota in 1980 to develop aquatic education materials (dealing with freshwater systems) for grades 5-9. The project resulted in the development and classroom testing of 13 instructional modules. A second grant (1982) funded workshops to introduce Minnesota…

  7. The neurotoxin BMAA in aquatic systems

    NARCIS (Netherlands)

    Faassen, E.J.

    2016-01-01

    Eutrophication is a major water quality issue and in many aquatic systems, it leads to the proliferation of toxic phytoplankton species. The neurotoxin β-N-methylamino-L-alanine (BMAA) is one of the compounds that can be present in phytoplankton. BMAA has been suggested to play a role in the ne

  8. Aquatics Therapy and the Halliwick Concept

    Science.gov (United States)

    Skinner, Alison; Thomson, Ann

    2008-01-01

    Aquatic therapy is the use of the properties of water for the therapeutic benefit of people of all ages and abilities. This article illustrates how people with disabilities may maximize the benefits of activities in water, including individual and group work and swimming. The overall aim is to encourage family activity and social interaction. The…

  9. Adapted Aquatics for Children with Autism

    Science.gov (United States)

    Martinez, Coleen A.

    2006-01-01

    This article provides information for physical education teachers to use while teaching their students with autism in an adapted aquatics unit plan. Crollick, Mancil, & Stopka (2006) have found that activities such as running, cycling, or swimming can reduce inappropriate behaviors in children who are autistic. They recommend further that…

  10. Aquatic Exercise and Heat-Related Injuries.

    Science.gov (United States)

    Sova, Ruth

    1991-01-01

    Heat-related injuries in aquatics classes are possible, though 100 percent preventable. The article discusses heat-related syndromes; how bodies generate and dissipate heat; how elevated heart rates that burn calories differ from those that dissipate heat; and modification of exercise intensity to provide calorie-burning workouts without…

  11. Black magic in the aquatic environment

    NARCIS (Netherlands)

    Jonker, M.T.O.

    2004-01-01

    Sorption to sediment controlsthe actual fate and risks ofhydrophobic organic contaminants (HOCs)in most aquatic environments. Sediment-bound HOCs are not readily available for uptake by organisms and degra

  12. Applicator Training Manual for: Aquatic Weed Control.

    Science.gov (United States)

    Herron, James W.

    The aquatic weeds discussed in this manual include algae, floating weeds, emersed weeds, and submerged weeds. Specific requirements for pesticide application are given for static water, limited flow, and moving water situations. Secondary effects of improper application rates and faulty application are described. Finally, techniques of limited…

  13. Toxicokinetic modeling challenges for aquatic nanotoxicology

    Directory of Open Access Journals (Sweden)

    Wei-Yu eChen

    2016-01-01

    Full Text Available Nanotoxicity has become of increasing concern since the rapid development of metal nanoparticles (NPs. Aquatic nanotoxicity depends on crucial qualitative and quantitative properties of nanomaterials that induce adverse effects on subcellular, tissue, and organ level. The dose-response effects of size-dependent metal NPs, however, are not well investigated in aquatic organisms. In order to determine the uptake and elimination rate constants for metal NPs in the metabolically active/ detoxified pool of tissues, a one-compartmental toxicokinetic model can be applied when subcellular partitioning of metal NPs data would be available. The present review is an attempt to describe the nano-characteristics of toxicokinetics and subcellular partitioning on aquatic organisms with the help of the mechanistic modeling for NP size-dependent physiochemical properties and parameters. Physiologically-based pharmacokinetic (PBPK models can provide an effective tool to estimate the time course of NP accumulation in target organs and is useful in quantitative risk assessments. NP accumulation in fish should take into account different effects of different NP sizes to better understand tissue accumulative capacities and dynamics. The size-dependent NP partition coefficient is a crucial parameter that influences tissue accumulation levels in PBPK modeling. Further research is needed to construct the effective systems-level oriented toxicokinetic model that can provide a useful tool to develop quantitatively the robustly approximate relations that convey a better insight into the impacts of environmental metal NPs on subcellular and tissue/organ responses in aquatic organisms.

  14. Systems and Cycles: Learning about Aquatic Ecosystems

    Science.gov (United States)

    Hmelo-Silver, Cindy E.; Jordan, Rebecca; Eberbach, Catherine; Rugaber, Spencer; Goel, Ashok

    2011-01-01

    In this research, the authors present both the design and preliminary testing of a technology-intensive classroom intervention designed to support middle schools students' understanding of an aquatic ecosystem. The goals of their intervention are to help learners develop deep understanding of ecosystems and to use tools that make the relationships…

  15. Thermal Pollution Impact upon Aquatic Life.

    Science.gov (United States)

    Shiomoto, Gail T.; Olson, Betty H.

    1978-01-01

    Conventional and nuclear power plants release waste heat to cooling water which then returns to receiving bodies of surface water. This thermal pollution causes a variety of effects in the aquatic ecosystem. More must be learned about these effects to ensure adequate regulation of thermal discharges. (RE)

  16. Aquatic Habitats, Level 4-9.

    Science.gov (United States)

    Weigel, Margaret

    Designed to acquaint students in grades 4-9 with aquatic plants and animals, this guide provides materials which can be used in preparation for field trips or laboratory work, for individual projects, as supplemental activities for a unit, or for learning center projects. Teacher background notes and an answer key for the student activites are…

  17. Science to support aquatic animal health

    Science.gov (United States)

    Purcell, Maureen K.; Harris, M. Camille

    2016-10-18

    Healthy aquatic ecosystems are home to a diversity of plants, invertebrates, fish and wildlife. Aquatic animal populations face unprecedented threats to their health and survival from climate change, water shortages, habitat alteration, invasive species and environmental contaminants. These environmental stressors can directly impact the prevalence and severity of disease in aquatic populations. For example, periodic fish kills in the upper Chesapeake Bay Watershed are associated with many different opportunistic pathogens that proliferate in stressed fish populations. An estimated 80 percent of endangered juvenile Puget Sound steelhead trout die within two weeks of entering the marine environment, and a role for disease in these losses is being investigated. The introduction of viral hemorrhagic septicemia virus (VHSV) into the Great Lakes—a fishery worth an estimated 7 billion dollars annually—resulted in widespread fish die-offs and virus detections in 28 different fish species. Millions of dying sea stars along the west coast of North America have led to investigations into sea star wasting disease. U.S. Geological Survey (USGS) scientists are assisting managers with these issues through ecological investigations of aquatic animal diseases, field surveillance, and research to promote the development of mitigation strategies.

  18. Biodegradation of Guanidinium By Aquatic Microorganisms.

    Science.gov (United States)

    1985-12-01

    Linear Alkylbenzene Sulfonates . Appl. Microbiol. 30:922-929. 21. Pfaender, F.K. and G.W. Bartholomew. 1982. Measurement of Aquatic Biodegradation Rates by...incubation, after which time its disappearance became linear , and it could no longer be detected by the 20th day. Results for an identical water sample

  19. Comparative efficacy of three suction traps for collecting phlebotomine sand flies (Diptera: Psychodidae) in open habitats.

    Science.gov (United States)

    Faiman, Roy; Cuño, Ruben; Warburg, Alon

    2009-06-01

    The efficacy of three suction traps for trapping phlebotomine sand flies (Diptera: Psychodidae) was compared. Traps were baited with Co(2) and used without any light source. CO(2)-baited CDC traps were evaluated either in their standard downdraft orientation or inverted (iCDC traps). Mosquito Magnet-X (MMX) counterflow geometry traps were tested in the updraft orientation only. Both updraft traps (iCDC and MMX) were deployed with their opening ∼10 cm from the ground while the opening of the downdraft (CDC) trap was ∼40 cm above ground. Comparisons were conducted in two arid locations where different sand fly species prevail. In the Jordan Valley, 3,367 sand flies were caught, 2,370 of which were females. The predominant species was Phlebotomus (Phlebotomus) papatasi, Scopoli 1786 (>99%). The updraft-type traps iCDC and MMX caught an average of 118 and 67.1 sand flies per trap night, respectively. The CDC trap caught 32.9 sand flies on average per night, significantly less than the iCDC traps. In the Judean desert, traps were arranged in a 3 × 3 Latin square design. A total of 565 sand flies were caught, 345 of which were females. The predominant species was P. (Paraphlebotomus) sergenti Parrot 1917 (87%). The updraft traps iCDC and MMX caught an average of 25.6 and 17.9 sand flies per trap per night, respectively. The CDC trap caught 7.8 sand flies on average per night, significantly less than the iCDC traps. The female to male ratio was 1.7 on average for all trap types. In conclusion, updraft traps deployed with their opening close to the ground are clearly more effective for trapping sand flies than downdraft CDC traps in open habitats.

  20. Suction catheter guided insertion of ProSeal laryngeal mask airway: Experience by untrained physicians

    Directory of Open Access Journals (Sweden)

    Valter Perilli

    2014-01-01

    Full Text Available Background: The use of suction catheter (SC has been shown to improve success rate during ProSeal laryngeal mask airway (PLMA insertion in expert users. Aims: The aim of this study was to compare insertion of PLMA performed by untrained physicians using a SC or the digital technique (DT in anaesthetised non-paralysed patients. Methods: In this prospective randomised double-blind study, conducted in the operating setting, 254 patients (American Society of Anaesthesiologists I-II, aged 18-65 years, undergoing minor surgery were enrolled. Exclusion criteria were body mass index >35 kg/m 2 , laryngeal or oesophageal varices, risk of aspiration or difficult face mask ventilation either referred or suspected (Langeron′s criteria ≥2 and modified Mallampati classification score >2. Participants were randomly allocated to one of the two groups in which PLMA was inserted using DT (DT-group or SC (SC-group. Statistical Analysis: Chi-square test with Yates′ correction, Mann-Whitney U-test or Student′s t-test were carried-out as appropriate. Results: The final insertion success rate was greater in SC-groupcompared with DT-group 90.1% (n = 109 versus 74.4% (n = 99 respectively (P = 0.002. Mean airway leak pressure was higher in SC-group compared to DT-group (23.7 ± 3.9 vs. 21.4 ± 3.2 respectively; (P = 0.001. There were no differences in insertion time, post-operative airway morbidity and complications. Conclusion: The findings of this study suggest that SC-technique improves the success rate of PLMA insertion by untrained physicians.

  1. The Effects of Aquatic Exercise on Physiological and Biomechanical Responses

    OpenAIRE

    Denning, Matthew M.

    2010-01-01

    Due to recent advances in aquatic research, technology, and facilities, many modes of aquatic therapy now exist. These aquatic modes assist individuals (e.g., osteoarthritis patients) in the performance of activities that may be too difficult to complete on land. However, the biomechanical requirements of each aquatic therapy mode may elicit different physiological and functional responses. Therefore, the purpose of this thesis was to: (a) provide a review of the physiological and biomechani...

  2. Aquatic macrophyte diversity of the Pantanal wetland and upper basin

    OpenAIRE

    VJ. Pott; Pott, A; LCP. Lima; SN. Moreira; AKM Oliveira

    2011-01-01

    This is a short review of the state of the art concerning diversity of aquatic macrophytes and the main aquatic vegetation types in the Brazilian Pantanal wetland and upper watershed. There are ca. 280 species of aquatic macrophytes on the Pantanal floodplain, with scarce endemism. On the upper watershed, Cerrado wetlands (veredas) and limestone springs have a distinct flora from the Pantanal, with twice the species richness. As a representative case of aquatic habitats influenced by river fl...

  3. Aquatic Plant Control Research Program: Effects of Water Chemistry on Submersed Aquatic Plants: A Synthesis

    Science.gov (United States)

    1990-07-01

    plants exhibiting C4 photosynthesis, C is conserved by refixing photorespired CO2. These terres- trial adaptations have counterparts in the aquatic...such as low photorespiration rates and low CO2 compensation points. The advantages of this photosynthetic pathway include conservation of... photorespired C and efficient C assimilation under the high dissolved oxygen and low free CO2 concentrations common in dense submersed aquatic plant populations

  4. Are sugarcane leaf-detritus well colonized by aquatic macroinvertebrates?

    Directory of Open Access Journals (Sweden)

    Luciene Aparecida Leite-Rossi

    Full Text Available AIM: The aim was to compare the kinetics of decomposition and the colonization of leaf litter of two plant species, the native Talauma ovata (pinha-do-brejo and the exotic Saccharum officinarum (sugarcane, by aquatic macroinvertebrates; METHODS: From each substrate, three recipients of colonization were taken from a stream, and the specimens identified to the lowest taxonomic level on days 7, 15, 34, 44, 61 and 75. The debris was weighed at the beginning and end of the experiment and determined their cell wall fractions; RESULTS: The coefficients of mineralization indicated higher velocity decay of organic matter refractory in T. ovata. There was no difference in taxonomic structure of macroinvertebrates, between the two substrates, but the community exhibited distinct functional feeding groups in the peak of colonization, with a greater number of shredders in T. ovata. The successive states of decomposition of the two plant detritus showed distinct macroinvertebrate densities; CONCLUSIONS: The amount and state of the plant biomass were important factors influencing the density and diversity of the macroinvertebrate fauna throughout the process of organic decomposition.

  5. Feed sources for livestock

    OpenAIRE

    Zanten, van, H.H.E.

    2016-01-01

    Production of food has re-emerged at the top of the global political agenda, driven by two contemporary challenges: the challenge to produce enough nutritious food to feed a growing and more prosperous human population, and the challenge to produce this food in an environmentally sustainable way. Current levels of production of especially animal-source food (ASF), pose severe pressure on the environment via their emissions to air, water, and soil; and their use of scarce resources, such as la...

  6. Live feeds in aquaculture

    OpenAIRE

    Dhert, Ph.; Sorgeloos, P

    1995-01-01

    Over the past two decades intensive larviculture of several fish and shellfish species has expanded into a multimillion dollar industry. Although much progress has been made in identifying the dietary requirements of the larvae of various aquaculture species, the mass culture of their early larval stages still requires the use of live feeds. Selected either through trial and error approaches or because of their convenience in mass production and use, hatcheries are relying today on three grou...

  7. Food Safety Information RSS feed

    Data.gov (United States)

    U.S. Department of Health & Human Services — This is an RSS Feed of Food Safety information that’s produced in real-time by the CDC. This RSS feed is the integration of two other XML feeds, one from the USDA's...

  8. Coupling between crossed dipole feeds

    DEFF Research Database (Denmark)

    Andersen, J.; Schjær-Jacobsen, Hans; Lessow, H.

    1974-01-01

    as a function of orientation and feeding network properties. The antennas are used as feeds for a parabolic reflector, and the effect of coupling on the secondary fields is analyzed. Especially significant is the polarization loss and it may, to some extent, be reduced by a proper choice of feeding network....

  9. Partitioning taxonomic diversity of aquatic insect assemblages and functional feeding groups in Neotropical Savanna headwater streams

    Science.gov (United States)

    Biological diversity can be divided into: alpha (α, local), beta (β, difference in assemblage composition among locals), and gamma (γ, total diversity). We assessed the partitioning of taxonomic diversity of Ephemeroptera, Plecoptera and Trichoptera (EPT) and of ...

  10. Enzymatic degradation of endocrine-disrupting chemicals in aquatic plants and relations to biological Fenton reaction.

    Science.gov (United States)

    Reis, A R; Sakakibara, Y

    2012-01-01

    In order to evaluate the removal performance of trace phenolic endocrine-disrupting chemicals (EDCs) by aquatic plants, batch and continuous experiments were conducted using floating and submerged plants. The EDCs used in this study were bisphenol A, 2,4-dichlorophenol, 4-tert-octylphenol, pentachlorophenol, and nonylphenol. The feed concentration of each EDC was set at 100 μg/L. Continuous experiments showed that every EDC except pentachlorophenol was efficiently removed by different aquatic plants through the following reaction, catalyzed by peroxidases: EDCs+H(2)O(2)→Products+H(2)O(2). Peroxidases were able to remove phenolic EDCs in the presence of H(2)O(2) over a wide pH range (from 3 to 9). Histochemical localization of peroxidases showed that they were located in every part of the root cells, while highly concentrated zones were observed in the epidermis and in the vascular tissues. Although pentachlorophenol was not removed in the continuous treatment, it was rapidly removed by different aquatic plants when Fe(2+) was added, and this removal occurred simultaneously with the consumption of endogenous H(2)O(2). These results demonstrated the occurrence of a biological Fenton reaction and the importance of H(2)O(2) as a key endogenous substance in the treatment of EDCs and refractory toxic pollutants.

  11. Functional Process Zones Characterizing Aquatic Insect Communities in Streams of the Brazilian Cerrado.

    Science.gov (United States)

    Godoy, B S; Simião-Ferreira, J; Lodi, S; Oliveira, L G

    2016-04-01

    Stream ecology studies see to understand ecological dynamics in lotic systems. The characterization of streams into Functional Process Zones (FPZ) has been currently debated in stream ecology because aquatic communities respond to functional processes of river segments. Therefore, we tested if different functional process zones have different number of genera and trophic structure using the aquatic insect community of Neotropical streams. We also assessed whether using physical and chemical variables may complement the approach of using FPZ to model communities of aquatic insects in Cerrado streams. This study was conducted in 101 streams or rivers from the central region of the state of Goiás, Brazil. We grouped the streams into six FPZ associated to size of the river system, presence of riparian forest, and riverbed heterogeneity. We used Bayesian models to compare number of genera and relative frequency of the feeding groups between FPZs. Streams classified in different FPZs had a different number of genera, and the largest and best preserved rivers had an average of four additional genera. Trophic structure exhibited low variability among FPZs, with little difference both in the number of genera and in abundance. Using functional process zones in Cerrado streams yielded good results for Ephemeroptera, Plecoptera, and Trichoptera communities. Thus, species distribution and community structure in the river basin account for functional processes and not necessarily for the position of the community along a longitudinal dimension of the lotic system.

  12. Insights into the Underwater Diving, Feeding, and Calling Behavior of Blue Whales from a Suction-Cup-Attached Video-Imaging Tag (CRITTERCAM)

    Science.gov (United States)

    2008-01-01

    San Diego Diane Gendron Centro Interdisciplinario de Ciencias Marinas Kelly Robertson Southwest Fisheries Science Center- NMFS/NOAA P A P E R Insights...on the remaining two could not be determined). Males were either alone or the trailing animal in a pair or trio. The two fe - males were always the

  13. Active control of vortex-induced vibrations of a circular cylinder using windward-suction- leeward-blowing actuation

    Science.gov (United States)

    Wang, Chenglei; Tang, Hui; Yu, Simon C. M.; Duan, Fei

    2016-05-01

    This paper studies the control of two-dimensional vortex-induced vibrations (VIVs) of a single circular cylinder at a Reynolds number of 100 using a novel windward-suction-leeward-blowing (WSLB) concept. A lattice Boltzmann method based numerical framework is adopted for this study. Both open-loop and closed-loop controls are implemented. In the open-loop control, three types of actuation arrangements, including the pure suction on the windward side of the cylinder, the pure blowing on the leeward side, and the general WSLB on both sides, are implemented and compared. It is found that the general WSLB is the most effective, whereas the pure suction is the least effective. In the closed-loop control, the proportional (P), integral (I), and proportional-integral (PI) control schemes are applied to adjust the WSLB velocities according to the flow information obtained from a sensor. The effects of four key control parameters including the proportional gain constant, the integral gain constant, the length of data history used for the feedback, and the location of the sensor are investigated. It is found that the use of only P control fails to completely suppress the VIV, the use of only I control can achieve the complete suppression, and the PI control performs the best in terms of both the control effectiveness and efficiency. In the PI control, there exists an optimal length of data history for the feedback, at which the VIV control is the most efficient. There also exist the minimum required WSLB velocities for the VIV suppression, independent of the control schemes. Moreover, it is found that the VIV control is independent of the sensor location.

  14. Toxicological effects of pyrethroids on non-target aquatic insects.

    Science.gov (United States)

    Antwi, Frank B; Reddy, Gadi V P

    2015-11-01

    The toxicological effects of pyrethroids on non-target aquatic insects are mediated by several modes of entry of pyrethroids into aquatic ecosystems, as well as the toxicological characteristics of particular pyrethroids under field conditions. Toxicokinetics, movement across the integument of aquatic insects, and the toxicodynamics of pyrethroids are discussed, and their physiological, symptomatic and ecological effects evaluated. The relationship between pyrethroid toxicity and insecticide uptake is not fully defined. Based on laboratory and field data, it is likely that the susceptibility of aquatic insects (vector and non-vector) is related to biochemical and physiological constraints associated with life in aquatic ecosystems. Understanding factors that influence aquatic insects susceptibility to pyrethroids is critical for the effective and safe use of these compounds in areas adjacent to aquatic environments.

  15. Widespread and persistent invasions of terrestrial habitats coincident with larval feeding behavior transitions during snail-killing fly evolution (Diptera: Sciomyzidae

    Directory of Open Access Journals (Sweden)

    Chapman Eric G

    2012-09-01

    Full Text Available Abstract Background Transitions in habitats and feeding behaviors were fundamental to the diversification of life on Earth. There is ongoing debate regarding the typical directionality of transitions between aquatic and terrestrial habitats and the mechanisms responsible for the preponderance of terrestrial to aquatic transitions. Snail-killing flies (Diptera: Sciomyzidae represent an excellent model system to study such transitions because their larvae display a range of feeding behaviors, being predators, parasitoids or saprophages of a variety of mollusks in freshwater, shoreline and dry terrestrial habitats. The remarkable genus Tetanocera (Tetanocerini occupies five larval feeding groups and all of the habitat types mentioned above. This study has four principal objectives: (i construct a robust estimate of phylogeny for Tetanocera and Tetanocerini, (ii estimate the evolutionary transitions in larval feeding behaviors and habitats, (iii test the monophyly of feeding groups and (iv identify mechanisms underlying sciomyzid habitat and feeding behavior evolution. Results Bayesian inference and maximum likelihood analyses of molecular data provided strong support that the Sciomyzini, Tetanocerini and Tetanocera are monophyletic. However, the monophyly of many behavioral groupings was rejected via phylogenetic constraint analyses. We determined that (i the ancestral sciomyzid lineage was terrestrial, (ii there was a single terrestrial to aquatic habitat transition early in the evolution of the Tetanocerini and (iii there were at least 10 independent aquatic to terrestrial habitat transitions and at least 15 feeding behavior transitions during tetanocerine phylogenesis. The ancestor of Tetanocera was aquatic with five lineages making independent transitions to terrestrial habitats and seven making independent transitions in feeding behaviors. Conclusions The preponderance of aquatic to terrestrial transitions in sciomyzids goes against the trend

  16. Physiologic changes induced by endotracheal instillation and suctioning in critically ill preterm infants with and without sedation.

    Science.gov (United States)

    Ninan, A; O'Donnell, M; Hamilton, K; Tan, L; Sankaran, K

    1986-04-01

    Endotracheal instillation and subsequent suctioning produces fluctuations of intracranial pressure (ICP), mean arterial pressure (MAP), and cerebral perfusion pressure (CPP) in sick preterm infants. In an attempt to observe if these fluctuations could be minimized using sedation, we studied a group of seven sick mechanically ventilated preterm infants with and without sedation. Continuous monitoring of ICP, MAP, heart rate, CPP, and arterial oxygen tension (PaO2) were obtained. The statistical analysis of the data revealed significant blunting of fluctuations of MAP, ICP, and CPP with sedation.

  17. Effects of Radiation and Chemical Reaction on MHD Convective Flow over a Permeable Stretching Surface with Suction and Heat Generation

    Directory of Open Access Journals (Sweden)

    Penem Mohan KRISNA

    2014-03-01

    Full Text Available In this study, we analyze the effects of thermal radiation and chemical reaction on the steady 2 dimensional stagnation point flow of a viscous incompressible electrically conducting fluid over a stretching surface, with suction and heat generation. The partial differential equations governing the flow are solved numerically by using the shooting technique. The effects of various parameters on velocity, temperature, and concentration profiles, as well as Nusselt number, Skin friction coefficient, and Sherwood number, are examined, and presented graphically and through tables. It is found that velocity, temperature, and rate of heat transfer of the fluid are influenced more by radiation and chemical reaction parameters, along with applied magnetic field.

  18. Hydromagnetic convective flow past a vertical porous plate through a porous medium with suction and heat source

    Directory of Open Access Journals (Sweden)

    S.S.Das, U.K.Tripathy, J.K.Das

    2010-05-01

    Full Text Available This paper theoretically analyzes the unsteady hydromagnetic free convective flow of a viscous incompressible electrically conducting fluid past an infinite vertical porous plate through a porous medium in presence of constant suction and heat source. Approximate solutions are obtained for velocity field, temperature field, skin friction and rate of heat transfer using multi-parameter perturbation technique. The effects of the flow parameters on the flow field are analyzed with the aid of figures and tables. The problem has some relevance in the geophysical and astrophysical studies.

  19. Malignant ventricular dysrhythmias in a patient with isovaleric acidemia receiving general and local anesthesia for suction lipectomy.

    Science.gov (United States)

    Weinberg, G L; Laurito, C E; Geldner, P; Pygon, B H; Burton, B K

    1997-12-01

    We report the occurrence of severe ventricular arrhythmias in a patient with isovaleric acidemia during general anesthesia for suction lipectomy. The timing of events and character of the ECG changes are most consistent with bupivacaine toxicity after subcutaneous injection of tumescence solution containing this local anesthetic. The patient had previously documented carnitine deficiency, a condition which, we speculate, may lower the threshold for bupivacaine induced cardiotoxicity. We review clinical considerations in isovaleric acidemia and conclude that the use of bupivacaine in these patients probably should be avoided.

  20. Sustainable exploitation and management of aquatic resources

    DEFF Research Database (Denmark)

    Neuenfeldt, Stefan; Köster, Fritz

    2014-01-01

    DTU Aqua conducts research, provides advice,educates at university level and contributes toinnovation in sustainable exploitation andmanagement of aquatic resources. The vision of DTUAqua is to enable ecologically and economicallysustainable exploitation of aquatic resourcesapplying an integrated...... management. Marineecosystems aims at understanding the mechanisms that govern the interaction between individuals,species and populations in an ecosystem enabling us to determine the stability and flexibility of theecosystem.Marine living resources looks at the sustainable utilization of fish and shellfish...... stocks.Ecosystem effects expands from the ecosystem approach to fisheries management to an integratedapproach where other human activities are taken into consideration. Fisheries management developsmethods, models and tools for predicting and evaluating the effects of management measures andregulations...

  1. Stall margin improvement of an axial flow fan with end wall injection and suction; Hekimen fukidashi suidashi ni yoru han'yo jikuryu sofuki no shissoku kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Nishioka, K.; Kuroda, H.; Obata, S.; Chimura, O. [National Defense Academy, Kanagawa (Japan)

    1999-06-25

    The experimental studies are conducted to reveal the mechanism of stall margin improvement of an axial flow fan by injection or suction from the end wall. In case of injection, the largest improvement is obtained by the injection at about 0. 14 {approx} 0 .21 times axial chord length downstream from leading edge. The reason for large improvement is that stall vortex, shed intermittent separation vortex and tip leakage vortex are dissipated by this injection, and also that this blowing suppresses the separation of boundary layer. In case of suction, the largest improvement is found for the suction from the end wall near leading edge. The amplitude of periodic static pressure after stall inception becomes smaller in comparison with injection cases. These effects are increased with the increase of suction flow rate, because the discharge of the vortex occurs more easily. On the other hand, the suction from the upstream of leading edge reduces the axial velocity near rotor tip, and then it induces stall. Also we tried to visualize the tip region flow, The suppression mechanism is discussed based on the visualization. The suppression of stall is successfully photographed. (author)

  2. Differential Effects of Endotracheal Suctioning on Gas Exchanges in Patients with Acute Respiratory Failure under Pressure-Controlled and Volume-Controlled Ventilation

    Directory of Open Access Journals (Sweden)

    Xiao-Wei Liu

    2015-01-01

    Full Text Available This study was conducted to evaluate the effects of open endotracheal suctioning on gas exchange and respiratory mechanics in ARF patients under the modes of PCV or VCV. Ninety-six ARF patients were treated with open endotracheal suctioning and their variations in respiratory mechanics and gas exchange after the suctions were compared. Under PCV mode, compared with the initial level of tidal volume (VT, ARF patients showed 30.0% and 27.8% decrease at 1 min and 10 min, respectively. Furthermore, the initial respiratory system compliance (Crs decreased by 29.6% and 28.5% at 1 min and 10 min, respectively. Under VCV mode, compared with the initial level, 38.6% and 37.5% increase in peak airway pressure (PAP were found at 1 min and 10 min, respectively. Under PCV mode, the initial PaO2 increased by 6.4% and 10.2 % at 3 min and 10 min, respectively, while 18.9% and 30.6% increase of the initial PaO2 were observed under VCV mode. Summarily, endotracheal suctioning may impair gas exchange and decrease lung compliance in ARF patients receiving mechanical ventilation under both PCV and VCV modes, but endotracheal suctioning effects on gas exchange were more severe and longer-lasting under PCV mode than VCV.

  3. Fermented liquid feed for pigs.

    Science.gov (United States)

    Missotten, Joris A M; Michiels, Joris; Ovyn, Anneke; De Smet, Stefaan; Dierick, Noël A

    2010-12-01

    Since the announcement of the ban on the use of antibiotics as antimicrobial growth promoters in the feed of pigs in 2006 the investigation towards alternative feed additives has augmented considerably. Although fermented liquid feed is not an additive, but a feeding strategy, the experimental work examining its possible advantages also saw a rise. The use of fermented liquid feed (FLF) has two main advantages, namely that the simultaneous provision of feed and water may result in an alleviation of the transition from the sow milk to solid feed and may also reduce the time spent to find both sources of nutrients, and secondly, that offering FLF with a low pH may strengthen the potential of the stomach as a first line of defence against possible pathogenic infections. Because of these two advantages, FLF is often stated as an ideal feed for weaned piglets. The results obtained so far are rather variable, but in general they show a better body weight gain and worse feed/gain ratio for the piglets. However, for growing-finishing pigs on average a better feed/gain ratio is found compared to pigs fed dry feed. This better performance is mostly associated with less harmful microbiota and better gut morphology. This review provides an overview of the current knowledge of FLF for pigs,dealing with the FLF itself as well as its effect on the gastrointestinal tract and animal performance.

  4. Environmental health impacts of feeding crops to farmed fish.

    Science.gov (United States)

    Fry, Jillian P; Love, David C; MacDonald, Graham K; West, Paul C; Engstrom, Peder M; Nachman, Keeve E; Lawrence, Robert S

    2016-05-01

    Half of the seafood consumed globally now comes from aquaculture, or farmed seafood. Aquaculture therefore plays an increasingly important role in the global food system, the environment, and human health. Traditionally, aquaculture feed has contained high levels of wild fish, which is unsustainable for ocean ecosystems as demand grows. The aquaculture industry is shifting to crop-based feed ingredients, such as soy, to replace wild fish as a feed source and allow for continued industry growth. This shift fundamentally links seafood production to terrestrial agriculture, and multidisciplinary research is needed to understand the ecological and environmental health implications. We provide basic estimates of the agricultural resource use associated with producing the top five crops used in commercial aquaculture feed. Aquaculture's environmental footprint may now include nutrient and pesticide runoff from industrial crop production, and depending on where and how feed crops are produced, could be indirectly linked to associated negative health outcomes. We summarize key environmental health research on health effects associated with exposure to air, water, and soil contaminated by industrial crop production. Our review also finds that changes in the nutritional content of farmed seafood products due to altered feed composition could impact human nutrition. Based on our literature reviews and estimates of resource use, we present a conceptual framework describing the potential links between increasing use of crop-based ingredients in aquaculture and human health. Additional data and geographic sourcing information for crop-based ingredients are needed to fully assess the environmental health implications of this trend. This is especially critical in the context of a food system that is using both aquatic and terrestrial resources at unsustainable rates.

  5. First feeding of larval herring

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Munk, Peter; Støttrup, Josianne

    1985-01-01

    The transition period from endogenous to exogenous feeding by larval herring was investigated in the laboratory for four herring stocks in order to evaluate the chances of survival at the time of fiest feeding. Observations on larval activity, feeding and growth were related to amount of yolk......, visual experience with potential prey organisms prior to first feeding and prey density. Herring larvae did not initiate exogenous feeding until around the time of yolk resorption. The timing of first feeding was not influenced by prior exposure to potential prey organisms during the yolk sac stage....... In the light of these observations, the ecological significance of the yolk sac stage is discussed. Initiation of exogenous feeding was delayed by 1-4 days at a low (7.5 nauplii .cntdot. l-1) compared to a high (120 nauplii .cntdot. l-1) prey density, but even at prey densities corresponding to the lower end...

  6. Pectinases in leaf degradation by aquatic Hyphomycetes

    OpenAIRE

    Chamier, Anne-Carole

    1980-01-01

    Packs of oak and alder leaves were submerged in late autumn in the River Bourne, a moderately eutrophic stream in Surrey so that the colonization pattern of aquatic Hyphomycetes on the leaves could be quantified as the leaves were degraded. The physico-chemical of the water was monitored over the experimental period and the inoculum available for leaf colonization was measured by filter counts of conidia in the stream. Colonization of the leaves by pectolytic bacteria was also measured. There...

  7. Toxicity of trifluoroacetate to aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Berends, A.G.; Rooij, C.G. de [Solvay S.A., Brussels (Belgium); Boutonnet, J.C. [Elf Atochem, Levallois-Perret (France); Thompson, R.S. [Zeneca Ltd., Devon (United Kingdom). Brixham Environmental Lab.

    1999-05-01

    As a result of the atmospheric degradation of several hydrofluorocarbons and hydrochlorofluorocarbons, trifluoroacetate (TFA) will be formed. Through precipitation, TFA will enter aquatic ecosystems. To evaluate the impact on the aquatic environment, an aquatic toxicity testing program was carried out with sodium trifluoroacetate (NaTFA). During acute toxicity tests, no effects of NaTFA on water fleas (Daphnia magna) and zebra fish (Danio retrio) were found at a concentration of 1,200 mg/L. A 7-d study with duckweed (Lemna gibba Ge) revealed a NOEC of 300 mg/L. On the basis of the results of five toxicity tests with Selenastrum capricornutum, they determined a NOEC of 0.12 mg/L. However, algal toxicity tests with NaTFA and Chlorella vulgaris, Scenedesmus subspicatus, Chlamydomonas reinhardtii, Dunaliella tertiolecta, Eugelan gracilis, Phaeodactylum tricornutum, Navicula pelliculosa, Skeletonema costatum, Anabaena flos-aquae, and Microcystis aeruginosa resulted in EC50 values that were all higher than 100 mg/L. The toxicity of TFA to S. capricornutum could be due to metabolic defluorination to monofluoroacetate (MFA), which is known to inhibit the citric acid cycle. A toxicity test with MFA and S. capricornutum revealed it to be about three orders of magnitude more toxic than TFA. However, a bioactivation study revealed that defluorination of TFA was less than 4%. On the other hand, S. capricornutum exposed to a toxic concentration of NaTFA showed a recovery of growth when citric acid was added, suggesting that TFA (or a metabolite of TFA) interferes with the citric acid cycle. A recovery of the growth of S. capricornutum was also found when TFA was removed from the test solutions. Therefore, TFA should be considered algistatic and not algicidic for S. capricornutum. On the basis of the combined results of the laboratory tests and a previously reported semi-field study, they can consider a TFA concentration of 0.10 mg/L as safe for the aquatic ecosystem.

  8. Aspects of Aquatic Pollution in Nigeria

    OpenAIRE

    A.T. Ekubo; J.F.N. Abowei

    2011-01-01

    Water pollution is a major problem in the global context. Yet aquatic resources consists of extremely wide range of floral and fauna resources which offer a broad array of goods with potential utilitarian application in agriculture, innovative industry and the pharmaceutical industry which renders valuable benefits and services. The slow poisoning of the waters is witnessed in Nigeria and the destruction of vegetation and agricultural land by oil spills which occur during petroleum operations...

  9. Fisheries and aquatic resources--fish health

    Science.gov (United States)

    Panek, Frank

    2008-01-01

    Fish health research at Leetown had its origin in the 1930’s when the Leetown Fish Hatchery and Experiment Station was constructed. In 1978, the National Fish Health Research Laboratory, now a component of the Leetown Science Center, was established to solve emerging and known disease problems affecting fish and other aquatic organisms critical to species restoration programs. Center scientists develop methods for the isolation, detection, and identification of fish pathogens and for prevention and control of fish diseases.

  10. Analysis of self-feeding in children with feeding disorders.

    Science.gov (United States)

    Rivas, Kristi M; Piazza, Cathleen C; Roane, Henry S; Volkert, Valerie M; Stewart, Victoria; Kadey, Heather J; Groff, Rebecca A

    2014-01-01

    In the current investigation, we evaluated a method for increasing self-feeding with 3 children with a history of food refusal. The children never (2 children) or rarely (1 child) self-fed bites of food when the choice was between self-feeding and escape from eating. When the choice was between self-feeding 1 bite of food or being fed an identical bite of food, self-feeding was low (2 children) or variable (1 child). Levels of self-feeding increased for 2 children when the choice was between self-feeding 1 bite of food or being fed multiple bites of the same food. For the 3rd child, self-feeding increased when the choice was between self-feeding 1 bite of food or being fed multiple bites of a less preferred food. The results showed that altering the contingencies associated with being fed increased the probability of self-feeding, but the specific manipulations that produced self-feeding were unique to each child.

  11. Aquatic therapy for patients with rheumatic disease.

    Science.gov (United States)

    McNeal, R L

    1990-11-01

    Aquatic therapy is justifiably a rapidly expanding, beneficial form of patient treatment. The goals established at the initial and subsequent evaluations usually are met as quickly and as sensibly as possible. Understanding the theory of water techniques is essential in implementing an aquatic therapy program. The success of the program, however, will always depend on the pleasure and benefits achieved by the patients. Remember, rheumatic patients most likely will need to modify their previous daily functioning. Patients need to be aware of the long-term ramifications of the disease process and understand how treatment and care may be altered during various stages of exacerbation and remission. Patient education is critical in ensuring individual responsibility for the changes that must be made when not supervised by a professional. Aquatic therapy is a step in molding a positive lifestyle change for the patient. The patient can be encouraged to be fitness oriented and, at the same time, exercise in a manner that is safe, effective, and biomechanically and physiologically sound. The environment, hopefully, also will be conductive to family and social interaction that ultimately encourages the compliance of long-term exercise programs.

  12. Feeding and Swallowing Disorders (Dysphagia) in Children

    Science.gov (United States)

    ... for the Public / Speech, Language and Swallowing / Swallowing Feeding and Swallowing Disorders (Dysphagia) in Children What are ... children with feeding and swallowing disorders ? What are feeding and swallowing disorders? Feeding disorders include problems gathering ...

  13. Feeding Tips For Your Baby with CHD

    Science.gov (United States)

    ... How To Feed Your Baby Either breast- or bottle-feeding works well for babies with heart problems, but ... do best with a combination of breast- and bottle-feeding. Breast-Feeding Your Baby If your baby is ...

  14. Feeding the Beast

    DEFF Research Database (Denmark)

    Hellström, Anders; Hervik, Peter

    2014-01-01

    of fear, we argue, this predisposes people to vote for anti-immigration parties. Our analysis highlights the position of anti-immigration parties; hence, the Sweden Democrats (SD) in Sweden and the Danish People’s Party (DPP) in Denmark. We use frame analysis to detect recurrent frames in the media debate...... as such plays a similar role and provides the DPP with an identity. We conclude that we are confronted with a two-faced beast that feeds on perceptions of the people as ultimately afraid of what are not recognized as native goods....

  15. Re-feeding syndrome.

    Science.gov (United States)

    Shadaba, A; Paine, J; Adlard, R; Dilkes, M

    2001-09-01

    The effect of a therapeutically administered high calorie diet in a severely malnourished patient is discussed in this case report. In patients with advanced head and neck cancer prolonged periods of malnutrition prior to admission are frequently encountered. This case report highlights the need to constantly monitor the electrolyte and vitamin levels during the early stages of instituting enteral or parenteral nutrition. By vigilant monitoring and a high index of suspicion re-feeding syndrome or severe hypophosphataemia and its associated complications can be avoided.

  16. Aquatic insects as the main food resource of fish the community in a Neotropical reservoir

    Directory of Open Access Journals (Sweden)

    Ana Paula Vidotto-Magnoni

    Full Text Available We evaluated the feeding of fish species of the Nova Avanhandava Reservoir, low Tietê River, São Paulo State, Brazil. Fishes were collected in two stretches of the reservoir: Santa Bárbara (14 samples and Bonito (two samples between September 2002 and March 2004, using gill and seining nets. The results of stomach contents analysis were expressed with the frequency of occurrence and gravimetric method, combined in the Alimentary Index (AI. The 20 species studied consumed 52 food items, grouped in 10 food categories: aquatic insects, terrestrial insects, crustaceans, fish, macroinvertebrates, microcrustaceans, algae, vegetal matter, detritus/sediment and scales. The aquatic insects (mainly Chironomidae, Odonata and Ephemeroptera were the most common food resources, consumed by 18 species. The diet composition of the community (species grouped indicated that the dominant food category in the diet of fishes was aquatic insects (AI = 77.6%, followed by crustaceans (AI = 7.1%. Four trophic guilds were identified according a cluster analysis (Pearson distance: insectivorous (10 species, omnivorous (4 species, detritivorous (3 species and piscivorous/carcinophagous (3 species. Despite the highest number of species, the insectivorous guild was responsible for more than 80% in captures in number and biomass (CPUEn and CPUEb. The low values of niche breadth presented by all species, along with the low values of diet overlap between species pairs indicate a high degree of food resources partitioning among species. The aquatic insects, despite being the main food resource of insectivorous fishes, also complemented the diet of other species, which demonstrate the importance of this food resource for the fish community, sustaining a high diversity, abundance and biomass of fishes.

  17. Baseline tissue concentrations of metal in aquatic oligochaetes: Field and laboratory approaches.

    Science.gov (United States)

    Méndez-Fernández, Leire; Martinez-Madrid, Maite; Pardo, Isabel; Rodriguez, Pilar

    2017-04-01

    Metal tissue residue evaluation in benthic macroinvertebrates is an important component of an integrated approach to ecological risk assessment of metals and metalloids in the Nalón River basin (North Spain), where historic mining activities took place. The purpose of this study was to know the baseline tissue concentration of 7 metals (Cd, Cu, Cr, Hg, Ni, Pb, and Zn) and one metalloid (As) in aquatic oligochaetes, sediment burrower organisms, representative of the collector-gatherer functional feeding group in the macroinvertebrate community. Metal concentration was measured in sediment and field aquatic oligochaetes at several reference (minimally disturbed) sites of the Nalón River basin, selected following Water Framework Directive criteria. Metal tissue residues were measured separately in field microdriles and lumbricids and compared with tissue concentrations measured in the aquatic oligochaete Tubifex tubifex exposed to reference sediments from the Nalón and other Cantabrian River basins in 28-d chronic laboratory bioassays. Metal tissue residues in bioassay organisms attained usually higher levels than in field worms, in special for As, Cu, Hg and Zn, although metal levels were within the same order of magnitude. The baseline values for metals were calculated from 90(th) percentile (P90) values in field aquatic oligochaetes (microdriles and lumbricids). The P90 for Hg, As and Zn could efficiently discriminate Toxic and Non-Toxic sites, while baseline values calculated for the other metals deserve further research due either to the low range of values found in the present study, or to the regulation of the metal body concentration, as in the case of Cu.

  18. Perancangan Sistem Permesinan Dan Sistem Penggerak Pada Auger Cutter Suction Dredger (ACSD Sebagai Metode Pengerukan Di Waduk

    Directory of Open Access Journals (Sweden)

    Andri Prasetyo

    2014-03-01

    Full Text Available Auger Cutter Suction Dredger (ACSD adalah salah salah satu jenis kapal keruk dari beberapa jenis kapal keruk yang ada. Sistem permesinan yang beroperasi pun lebih bervariatif karena selain kapal harus bergerak (moving kapal juga melakukan aktivitasnya dalam melakukan pengerukan. Dalam operasinya, kapal keruk ini akan bekerja di area waduk. Dan juga sangat cocok diaplikasikan di sungai dan rawa. Dalam perancangan sistem permesinannya ada beberapa parameter yang perlu diperhatikan antara lain lokasi pengerukan, kapasitas produksi, kedalaman pengerukan, jenis material yang akan dikeruk, ukuran kapal, dan akses menuju ke tempat kerja. Dalam skripsi ini, akan dilakukan beberapa variasi perhitungan, analisa dan desain rencana umum kapal keruk (ACSD. Perhitungan dan analisa yang dilakukan pada sistem permesinannya antara lain perhitungan kapasitas dan penentuan pompa hisap, perhitungan dan pemilihan mesin Independen drive, pemilihan cutterhead, perhitungan kapasitas dan penentuan ladder winch suction pipe, desain kapal keruk yang direncanakan. Selanjutnya, setelah dilakukan perhitungan dan analisa tersebut, penentuan spesifikasi dijadikan dasar dalam pemilihan komponen / unit pada sistem permesinan kapal keruk ACSD tersebut.

  19. Effect of Suction Nozzle Pressure Drop on the Performance of an Ejector-Expansion Transcritical CO2 Refrigeration Cycle

    Directory of Open Access Journals (Sweden)

    Zhenying Zhang

    2014-08-01

    Full Text Available The basic transcritical CO2 systems exhibit low energy efficiency due to their large throttling loss. Replacing the throttle valve with an ejector is an effective measure for recovering some of the energy lost in the expansion process. In this paper, a thermodynamic model of the ejector-expansion transcritical CO2 refrigeration cycle is developed. The effect of the suction nozzle pressure drop (SNPD on the cycle performance is discussed. The results indicate that the SNPD has little impact on entrainment ratio. There exists an optimum SNPD which gives a maximum recovered pressure and COP under a specified condition. The value of the optimum SNPD mainly depends on the efficiencies of the motive nozzle and the suction nozzle, but it is essentially independent of evaporating temperature and gas cooler outlet temperature. Through optimizing the value of SNPD, the maximum COP of the ejector-expansion cycle can be up to 45.1% higher than that of the basic cycle. The exergy loss of the ejector-expansion cycle is reduced about 43.0% compared with the basic cycle.

  20. Unsteady MHD Slip Flow of a Non-Newtonian Casson Fluid due to Stretching Sheet with Suction or Blowing Effect

    Directory of Open Access Journals (Sweden)

    A Mahdy

    2016-01-01

    Full Text Available In this contribution a numerical study is carried out to analyze the effect of slip at the boundary of unsteady two-dimensional MHD flow of a non-Newtonian fluid over a stretching surface having a prescribed surface temperature in the presence of suction or blowing at the surface. Casson fluid model is used to characterize the non-Newtonian fluid behavior. With the help of similarity transformations, the governing partial differential equations corresponding to the momentum and heat transfer are reduced to a set of non-linear ordinary differential equations, which are then solved for local similar solutions using the very robust computer algebra software MATLAB. The flow features and heat transfer characteristics for different values of the governing parameters are graphically presented and discussed in detail. Comparison with available results for certain cases is excellent. The effect of increasing values of the Casson parameter is seen to suppress the velocity field. But the temperature is enhanced with increasing Casson parameter. For increasing slip parameter, velocity increases and thermal boundary layer becomes thinner in the case of suction or blowing.

  1. Interrupting characteristics of puffer and suction type SF/sub 6/ gas interrupter especially in thermal breakdown region

    Energy Technology Data Exchange (ETDEWEB)

    Natsui, K.; Hirasawa, K.; Hirata, K.; Nakamura, I.; Takasuna, T.; Yoshioka, Y.

    1984-04-01

    Interrupting characteristics in thermal region within the range of 30-60kA current levels have been examined with an experimental model breaker under some SF/sub 6/ gas pressures of 4.5-15 bars. The interrupter tested with the breaker was designed to shorten the arcing time based on the puffer principle with the aid of a suction chamber. Arcing time was shortened with the fastly established gas-flow into the suction chamber in comparison with conventional puffer type interrupters. Interrupting characteristics in short arcing time region were much influenced by interrupter structures, interrupting currents, filling gas pressures and rates of rise of recovery voltage (rrrV). Particularly, in large current region over 50kA, the minimum arcing time was sensitively affected by moving side interrupter structures. Using a newly developed interrupter characterized by a follower type insulating nozzle, it has demonstrated a minimum arcing time of 0.37 cycles for the 63kA 90% short line fault (SLF) condition for two breaks per pole under an SF/sub 6/ gas pressure of 10 bars, and also has demonstrated 0.33 cycles for the 50kA 90% SLF condition under a pressure of 6 bars.

  2. [Postoperative closed suction drainage following hip and knee aloarthroplasty: drain removal after 24 or after 48 hours?].

    Science.gov (United States)

    Erceg, Marinko; Becić, Kristijan

    2008-01-01

    The use of closed-suction drainage systems after total hip and knee replacement is a common practice. It is believed that drainage reduces the haematomas and infection. The usual time to remove drains is 48 hours. Usefulness of the long time drainage of the haematomas and possible harmfulness of infection is still a subject of discussion. In this article, using our own operative material, we want to show the justification of the 48 hour duration of closed-suction drainage. The investigation was done on the patients with hip replacement (45 patients) and knee replacement (11 patients). The amount of blood in the drainage systems in the first 24 hours after the surgery and after 24 hours till the removal of drainage was observed. The results show that the amount of blood lost in the drainage system in the first 24 hours was on average 95.29%, and only 4.71% in the next 24 hours. This article supports the opinion that postoperative drainage has to be removed after 24 hours, i.e. the 48 hours-drainage seems not to be justified.

  3. A Numerical Study on the Improvement of Suction Performance and Hydraulic Efficiency for a Mixed-Flow Pump Impeller

    Directory of Open Access Journals (Sweden)

    Sung Kim

    2014-01-01

    Full Text Available This paper describes a numerical study on the improvement of suction performance and hydraulic efficiency of a mixed-flow pump by impellers. The design of these impellers was optimized using a commercial CFD (computational fluid dynamics code and DOE (design of experiments. The design variables of meridional plane and vane plane development were defined for impeller design. In DOE, variables of inlet part were selected as main design variables in meridional plane, and incidence angle was selected in vane plane development. The verification of the experiment sets that were generated by 2k factorial was done by numerical analysis. The objective functions were defined as the NPSHre (net positive suction head required, total efficiency, and total head of the impellers. The importance of the geometric design variables was analyzed using 2k factorial designs. The interaction between the NPSHre and total efficiency, according to the meridional plane and incidence angle, was discussed by analyzing the 2k factorial design results. The performance of optimally designed model was verified by experiments and numerical analysis and the reliability of the model was retained by comparison of numerical analysis and comparative analysis with the reference model.

  4. Oxytocin, feeding and satiety

    Directory of Open Access Journals (Sweden)

    Nancy eSabatier

    2013-03-01

    Full Text Available Oxytocin neurones have a physiological role in food intake and energy balance. Central administration of oxytocin is powerfully anorexigenic, reducing food intake and meal duration. The central mechanisms underlying this effect of oxytocin have become better understood in the past few years. Parvocellular neurones of the paraventricular nucleus project to the caudal brainstem to regulate feeding via autonomic functions including the gastrointestinal vago-vagal reflex. In contrast, magnocellular neurones of the supraoptic and paraventricular nuclei release oxytocin from their dendrites to diffuse to distant hypothalamic targets involved in satiety.The ventromedial hypothalamus, for example, expresses a high density of oxytocin receptors but does not contain detectable oxytocin nerve fibres. Magnocellular neurones represent targets for the anorexigenic neuropeptide α-melanocyte stimulating hormone. . In addition to homeostatic control, oxytocin may also have a role in reward-related feeding. Evidence suggests that oxytocin can selectively suppress sugar intake and that it may have a role in limiting the intake of palatable food by inhibiting the reward pathway.

  5. Advanced Liquid Feed Experiment

    Science.gov (United States)

    Distefano, E.; Noll, C.

    1993-06-01

    The Advanced Liquid Feed Experiment (ALFE) is a Hitchhiker experiment flown on board the Shuttle of STS-39 as part of the Space Test Payload-1 (STP-1). The purpose of ALFE is to evaluate new propellant management components and operations under the low gravity flight environment of the Space Shuttle for eventual use in an advanced spacecraft feed system. These components and operations include an electronic pressure regulator, an ultrasonic flowmeter, an ultrasonic point sensor gage, and on-orbit refill of an auxiliary propellant tank. The tests are performed with two transparent tanks with dyed Freon 113, observed by a camera and controlled by ground commands and an on-board computer. Results show that the electronic pressure regulator provides smooth pressure ramp-up, sustained pressure control, and the flexibility to change pressure settings in flight. The ultrasonic flowmeter accurately measures flow and detects gas ingestion. The ultrasonic point sensors function well in space, but not as a gage during sustained low-gravity conditions, as they, like other point gages, are subject to the uncertainties of propellant geometry in a given tank. Propellant transfer operations can be performed with liquid-free ullage equalization at a 20 percent fill level, gas-free liquid transfer from 20-65 percent fill level, minimal slosh, and can be automated.

  6. Refraction changes during elevation of intraocular pressure by suction cup, their reflection in the pattern visual evoked cortical potential and their compensation.

    Science.gov (United States)

    Bernd, A; Ulrich, W D; Teubel, H; Rohrwacher, F; Barth, T

    1993-01-01

    Visual evoked cortical potential studies using pattern stimuli with the intraocular pressure raised artificially by the suction cup method have been reported. Possible changes in the refraction of the eye due to the method employed and their influence on the pattern visual evoked cortical potential have not been considered. Changes in the refraction of the eye during artificial intraocular pressure elevation and the influence of such changes on pattern visual evoked cortical potentials were studied. The refraction changes were found to depend on the shape of the suction cup. They could be compensated for by employing properly shaped suction cups and contact lenses. The behavior of amplitude and latency of the pattern visual evoked cortical potential at artificially elevated intraocular pressure with compensation for refraction changes has been studied and found to depend in a characteristic manner on ocular perfusion pressure.

  7. 流体力学泊肃叶定律在吸痰术中的应用%Application of Fluid Mechanics Poiseuille Law on Sputum Suctioning

    Institute of Scientific and Technical Information of China (English)

    胡霞; 范英英

    2014-01-01

    Objective To discuss the application of fluid mechanics Poiseuille law on sputum suctioning. Methods The sputum was divided into two samples of rice-water alike or white foam alike thin phlegm and turbid yellow sticky phlegm.The sputum suction effects under four suctioning pressure (-0.01,-0.02,-0.03,-0.04 MPa)were evaluated by testing three sized of pipe 6 Fr、8 Fr、10 Fr using in vitro children sputum suction apparatus.Results The suctioning time of 5 ml thin phlegm in 6 Fr、8 Fr、10 Fr three sizes of the pipe were 38,12 and 5 s under the suctioning pressure of -0.01 MPa,while the suctioning time for 5 ml sticky phlegm were >600,600,357 s.With the increasing of suctioning pressure from -0.01 to -0.02,-0.03,-0.04 MPa,the amount of sputum suction within 15 s of 6 Fr、8 Fr、10 Fr three sizes of the pipe were 0,0,0,0.27 ml;0.125,0.25,0.83,0.15 ml and 0.21,0.83,2.5,3.75 ml. Conclusion The sputum suctioning needs to evaluate the relationship between size of the pipe,suctioning pressure and viscosity of sputum.In sputum suctioning,low pressure and big size pipe were equally effec-tive as high pressure small size pipe,if there was no change in pressure and the size of the pipe,thin phlegm was the best choice for reduce the flow resistance.%探讨流体力学泊肃叶定律在吸痰术中的应用.方法将收集痰液分成米汤样或白色泡沫样的稀痰与浊黄色凝成痂块的黏痰两种样品,在体外用小儿吸痰器测试6 Fr、8 Fr、10 Fr 三种管径吸痰管在四种吸引压力(-0.01、-0.02、-0.03、-0.04 MPa)下的吸痰效果.结果6 Fr、8 Fr、10 Fr三种管径吸痰管,在吸引压为-0.01 MPa时吸引5 ml 稀痰所需时间分别为38、12、5 s;5 ml黏痰时所需时间分别为>600、600、357 s.随着吸引压力由-0.01、向-0.02、-0.03、-0.04 MPa的递增,6 Fr 、8 Fr、10 Fr三种吸痰管在15 s内吸引黏痰的量分别为0、0、0、0.27 ml;0.125、0.25、0.83、0.15 ml 和0.21、0.83

  8. Effects of radial diffuser hydraulic design on a double-suction centrifugal pump

    Science.gov (United States)

    Hou, H. C.; Zhang, Y. X.; Xu, C.; Zhang, J. Y.; Li, Z. L.

    2016-05-01

    In order to study effects of radial diffuser on hydraulic performance of crude oil pump, the steady CFD numerical method is applied and one large double-suction oil pump running in long-distance pipeline is considered. The research focuses on analysing the influence of its diffuser vane profile on hydraulic performance of oil pump. The four different types of cylindrical vane have been designed by in-house codes mainly including double arcs (DA), triple arcs (TA), equiangular spiral line (ES) and linear variable angle spiral line (LVS). During design process diffuser vane angles at inlet and outlet are tentatively given within a certain range and then the wrapping angle of the four types of diffuser vanes can be calculated automatically. Under the given inlet and outlet angles, the linear variable angle spiral line profile has the biggest wrapping angle and profile length which is good to delay channel diffusion but bring more friction hydraulic loss. Finally the vane camber line is thickened at the certain uniform thickness distribution and the 3D diffuser models are generated. The whole flow passage of oil pump with different types of diffusers under various flow rate conditions are numerically simulated based on RNG k-ɛ turbulent model and SIMPLEC algorithm. The numerical results show that different types of diffusers can bring about great difference on the hydraulic performance of oil pump, of which the ES profile diffuser with its proper setting angle shows the best hydraulic performance and its inner flow field is improved obviously. Compared with the head data from model sample, all designed diffusers can make a certain improvement on head characteristic. At the large flow rate conditions the hydraulic efficiency increases obviously and the best efficiency point shift to the large flow rate range. The ES profile diffuser embodies the better advantages on pump performance which can be explained theoretically that the diffuser actually acts as a diffusion

  9. Investigation of seepage around the bucket skirt during installation in sand:AAU CPT-based method for the installation of suction bucket

    OpenAIRE

    Koteras, Aleksandra Katarzyna; Ibsen, Lars Bo

    2015-01-01

    First aim of this study is to evaluate a pore pressure factor, . The factor describes the ratio between the excess pore pressure generated on the bucket tip and the applied suction under the bucket lid. The pore pressure factor can be then used for prediction of excess pore pressure at the tip or along bucket skirt with known soil condition, bucket geometry and applied suction.The second aim of the study is to evaluate expressions for normalized seepage length, s/h, for different soil combina...

  10. An experimental investigation of the independent effect of suction and degree of saturation on very small-strain stiffness of unsaturated sand

    Directory of Open Access Journals (Sweden)

    Pagano Arianna

    2016-01-01

    Full Text Available The paper presents an experimental investigation of very small strain stiffness of unsaturated sand. A triaxial test apparatus was equipped with bender elements and compression discs in order to assess the stiffness at very small strains by measuring the velocity of propagation of shear and compression waves through an unsaturated sample. The negative water column method was adopted to apply suction at the base of the sample. The experiments were designed to investigate the independent effect of suction and degree of saturation on the wave propagation velocities. This was achieved by testing the sand sample on both the drying and wetting path.

  11. 非饱和土吸力控制的渗析技术%Osmosis of Suction Pressure Control in Unsaturated Soil

    Institute of Scientific and Technical Information of China (English)

    毛尚之

    2000-01-01

    本文介绍了非饱和土试验中的吸力控制方法,并着重介绍了渗析技术的方法及其应用,该方法具有安全、简便、控制吸力的范围大且效果好的特点,值得参考借鉴。%The way to control suction pressure in the test of unsaturated soil is introduced. Technique and application of osmosis are stressed, which is safe, simple, with large range of suction controlling and the result is satisfactory.

  12. Effects of Ostomy Suction on Perianal Skin Care of Critically Ill Patients with Fecal Incontinence%造口袋负压吸引用于危重病人大便失禁肛周皮肤护理的效果观察

    Institute of Scientific and Technical Information of China (English)

    魏红云; 张艳; 周燕莉; 史秀英; 傅卫军

    2013-01-01

    Objective To explore the effects of ostomy suction on perianal skin care of critically ill patients with fecal incontinence. Methods The participants included 25 patients with fecal incontinence. The anal ostomy bags were connected with two disposable drainage tubes. Tube A was connected with a central suction device, and was set in an intermittent or continuous negative pressure of-20~-40 kPa and tube B was regularly cleaned by feeding empty needle extracting warm water or saline, and was then bundled with rubber bands after rinse. Results Among 25 patients, the maximum duration of the ostomy bag connecting suction device was 15.6 days, and the minimum 3.3 days. Except one patients with Ⅲ perianal skin damage had died, sixteen patients with I and II perianal skin damage recovered and their skin flushing were subsided;eight patients with intact perianal skin showed no skin damage after the usage of ostomy bag connecting suction devices. Conclusion The ostomy bag connecting suction devices is effective for avoiding the perianal skin irritation of stool and protecting perianal skin intact, which is also helpful in ensuring the security of critically ill patients and reducing care costs. Meanwhile, ostomy bag connecting suction devices effectively reduce the workload of nurses and could be widely promoted in ICU care.%  目的探讨造口负压吸引装置在合并大便失禁的危重病人肛周皮肤护理中的效果。方法对于大便失禁的危重病人,通过对肛门使用造口袋连接2根一次性引流管,将1根连接中心负压吸引装置进行间断或者持续负压吸引为吸引管,压力-20~-40 kPa,另1根定期用灌食空针抽取温开水或生理盐水清洗为冲洗管,冲洗结束后用橡皮筋捆扎。结果25例发生大便失禁危重病人中,造口袋连接负压吸引装置使用最长15.6 d,最短3.3 d,平均6.7 d;除1例Ⅲ度肛周皮肤损伤病人死亡外,肛周皮肤损伤Ⅰ度和Ⅱ度共16例

  13. Oligochaeta (Annelida: Clitellata) associated to aquatic macrophytes in Brazil

    OpenAIRE

    Nathalie Aparecida de Oliveira Sanches; Marina Gulo Alcorinte; Lucas Henrique Sahm; Guilherme Rossi Gorni; Maria Lúcia Ribeiro

    2016-01-01

    Oligochaeta are still characterized as a poorly studied group among the aquatic macroinvertebrates and few studies about their ecology were conducted in Brazil. Thus, our study aimed to provide an overview of the association between Oligochaeta and macrophytes, in Brazilian continental aquatic environments, by means of a literature review along with an inventory of species associated to aquatic macrophytes on marginal lagoons in the reservoir Ribeirão das Anhumas (Américo Brasiliense, São Pau...

  14. Prey perception in feeding-current feeding copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Goncalves, Rodrigo J.; Florian Couespel, Damien

    2016-01-01

    We reply to the comments of Paffenhöfer and Jiang () who argues that remote chemical prey perception is necessary for feeding-current feeding copepods to fulfill their nutritional requirements in a dilute ocean, that remote chemical prey detection may only be observed at very low prey concentrati...

  15. Inland Aquatic Resources and Biogeochemical Cycles

    Science.gov (United States)

    Melack, J. M.

    1984-01-01

    The biosphere is the entire planetary system that includes, sustains and is influenced by life. The central issue of the science of the biosphere is the extent to which the Earth's surface, atmosphere and hydrosphere is the result of biological rather than abiotic processes. Space science and technology accelerates the understanding of global biological processes by providing repetive synoptic observations on large spatial scales once the relationships between the processes and the remotely sensed quantities are established. Especially promising applications of space technology are the measurement of biological productivity and portions of geochemical cycles in aquatic ecosystems and the evaluation and management of the quality of freshwater resources.

  16. Decomposition of aquatic plants in lakes

    Energy Technology Data Exchange (ETDEWEB)

    Godshalk, G.L.

    1977-01-01

    This study was carried out to systematically determine the effects of temperature and oxygen concentration, two environmental parameters crucial to lake metabolism in general, on decomposition of five species of aquatic vascular plants of three growth forms in a Michigan lake. Samples of dried plant material were decomposed in flasks in the laboratory under three different oxygen regimes, aerobic-to-anaerobic, strict anaerobic, and aerated, each at 10/sup 0/C and 25/sup 0/C. In addition, in situ decomposition of the same species was monitored using the litter bag technique under four conditions.

  17. Monitoring aquatic environments with autonomous systems

    DEFF Research Database (Denmark)

    Christensen, Jesper Philip Aagaard

    High frequency measurements from autonomous sensors have become a widely used tool among aquatic scientists. This report focus primarily on the use of ecosystem metabolism based on high frequency oxygen measurements and relates the calculations to spatial variation, biomass of the primary producers...... and in shallow systems the macrophytes can completely dominate primary production. This was despite the fact that the plants in the studied system were light-saturated most of the light hours and occasionally carbon limited. It was also shown that the GPP and the total phytoplankton biomass in a nutrient...

  18. Aquatic species project report: FY 1991

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.M. [National Renewable Energy Lab., Golden, CO (United States); Sprague, S. [USDOE, Washington, DC (United States)

    1992-04-01

    This report summarizes the progress and research accomplishments of the Aquatic Species Project, which is managed by the National Renewable Energy Laboratory for the US Department of Energy. The project is focused on applying genetic engineering techniques to enhance the lipid, or oil, production of microalgae. Those lipids can be extracted and processed into high-energy liquid fuels such as diesel. Because microalgae require carbon dioxide, a major ``greenhouse`` gas, as a nutrient, project researchers also study the role that microalgae could play in a possible global climate change mitigation strategy.

  19. Aquatic species project report: FY 1991

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.M. (National Renewable Energy Lab., Golden, CO (United States)); Sprague, S. (USDOE, Washington, DC (United States))

    1992-04-01

    This report summarizes the progress and research accomplishments of the Aquatic Species Project, which is managed by the National Renewable Energy Laboratory for the US Department of Energy. The project is focused on applying genetic engineering techniques to enhance the lipid, or oil, production of microalgae. Those lipids can be extracted and processed into high-energy liquid fuels such as diesel. Because microalgae require carbon dioxide, a major greenhouse'' gas, as a nutrient, project researchers also study the role that microalgae could play in a possible global climate change mitigation strategy.

  20. Aquatic Exercise and Thermoregulation in Pregnancy.

    Science.gov (United States)

    Soultanakis, Helen N

    2016-09-01

    Aquatic exercise, in a general sense, is any type of movement performed in the water for the purpose of improving health and fitness. Water, with its properties, provides buoyancy to lighten the "load" of pregnancy, hydrostatic pressure to alleviate pregnancy-induced edema, and many other benefits. Sports in extreme temperatures may involve some risks. The fact that a person's conductivity increases about 25 times in water comes with a great loss, which is the depression of the evaporative mechanism. Altered thermal control mechanisms in water, both in the gravid and the nongravid state, will be addressed in this review. convenience.