988 resultados para drifting
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Restoring a misaligned tooth with an inadequate contact point is a challenge to the practitioner. In some instances, teeth that could be repositioned and adequately restored are extracted. Thus, the aim of this article was to describe a treatment using orthodontic and prosthetic techniques to restore esthetics and function in a patient with a distally drifted maxillary lateral incisor. The patient's functional and esthetic expectations were successfully met with the outlined treatment.
The cetacean offal connection: Feces and vomits of spinner dolphins as a food source for reef fishes
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At Fernando de Noronha Archipelago, southwest Atlantic, reef fishes associated with spinner dolphins (Stenella longirostris) were recorded when the cetaceans congregated in a shallow inlet. In the reef waters the dolphins engaged in several behaviors such as resting, aerial displays and other social interactions, as well as eliminative behaviors such as defecating and vomiting. Twelve fish species in seven families were recorded feeding on dolphin offal. The black durgon (Melichthys niger) was the most ubiquitous waste-eater, and its group size was positively and significantly correlated with dolphin group size. The durgons recognized the postures a dolphin adopts prior to defecating or vomiting, and began to converge to an individual shortly before it actually voided. Offal was quickly fed upon, and the fishes concentrated in the area occupied by the dolphins until the latter left the shallows. Since all the recorded offal-feeding species feed on plankton or drifting algae, feeding on cetacean droppings may be regarded as a switch from foraging on drifting organisms to foraging on drifting offal, a predictable food source in the inlet. Further instances of this cetacean-fish association are predicted to occur at sites where these mammals congregate over reefs with clear water and plankton-eating fishes.
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Recent studies have demonstrated that the sheath dynamics in plasma immersion ion implantation (PIII) is significantly affected by an external magnetic field. In this paper, a two-dimensional computer simulation of a magnetic-field-enhanced PHI system is described. Negative bias voltage is applied to a cylindrical target located on the axis of a grounded vacuum chamber filled with uniform molecular nitrogen plasma. A static magnetic field is created by a small coil installed inside the target holder. The vacuum chamber is filled with background nitrogen gas to form a plasma in which collisions of electrons and neutrals are simulated by the Monte Carlo algorithm. It is found that a high-density plasma is formed around the target due to the intense background gas ionization by the magnetized electrons drifting in the crossed E x B fields. The effect of the magnetic field intensity, the target bias, and the gas pressure on the sheath dynamics and implantation current of the PHI system is investigated.
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Previous ecological studies on foraminifera and ostracoda from the tropical Sepetiba Bay, located in the southern part of the State of Rio de Janeiro, Brazil, have noted the presence in this area of some cool water taxons typical of the Argentine continental platform. These studies have proposed that parcels of these temperate waters with their associated biological indicators are advected northward along the platform, penetrating into some tropical entrances of the southeast coast of Brazil. In the present study, ecological data (foraminifera, ostracoda and microbivalves), are used together with information obtained by satellite tracked drifting buoys and digital thermal imagery obtained from NOAA satellites to indicate the path taken by these high latitude species along the southern Brazilian coast to arrive in the Sepetiba Bay, near the city of Rio de Janeiro. Our general conclusion is that biotic elements native to the colder, less saline marine waters seen to the south of Brazil have been and are being advected northward along the inner part of the continental platform to about 22 degrees S. Water parcels containing this biota may, in a sporadic fashion, enter into the tropical Sepetiba Bay. The passage of meteorological fronts through the region is considered to be an important if not the principal mechanism for the sporadic entry of the cool water into the Southern Coastal Entrance of the State of Rio de Janeiro. (C) 1998 Elsevier B.V.s Ltd. All rights reserved.
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The effect of magnetic field enhanced plasma immersion ion implantation (PIII) in silicon substrate has been investigated at low and high pulsed bias voltages. The magnetic field in magnetic bottle configuration was generated by two magnetic coils installed outside the vacuum chamber. The presence of both, electric and magnetic field in PIII creates a system of crossed E x B fields, promoting plasma rotation around the target. The magnetized electrons drifting in crossed E x B fields provide electron-neutral collision. Consequently, the efficient background gas ionization augments the plasma density around the target where a magnetic confinement is achieved. As a result, the ion current density increases, promoting changes in the samples surface properties, especially in the surface roughness and wettability and also an increase of implantation dose and depth. (C) 2012 Elsevier B. V. All rights reserved.
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The Paraná Basin is a Western Gondwanan cratonic basin that is better defined as the Paraná depositional site, since it has a diverse history as a basin. Sedimentation started in the Ordovician-Silurian, followed by extensive marine Devonian deposition. A Late Paleozoic/ Triassic facies cycle wedge was clearly built during Pangean time. The Early Cretaceous was characterized by extensive basaltic lava flows immediately before the break-up of Pangea. Following these rifting and drifting processes, the basin's structural framework was totally rebuilt, generating new depositional sites in the Late Cretaceous to Tertiary. Based on more recent data, at least two different basins may be defined during the evolution of what was once considered a unique basin. Nevertheless, even if considered as a single basin, the sedimentary pile of the Paraná Basin has considerable economic potential, until now exploited only rudimentarily, except for its groundwater resources. Aggregates, limestones, clays, industrial sands, gems, dimension stones, hydrocarbons, coal, peat, and uranium are some of the potential mineral resources of this basin. Copyright © 1997 by V. H. Winston & Son, Inc. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Desenvolvendo tema tão privilegiado pela literatura quanto o da orgânica relação entre corpo e linguagem, o romance Ó, de Nuno Ramos, tangencia os limites entre escrita do corpo e escrita da morte a partir de uma crise da linguagem desencadeada pela degenerescência do corpo. A crise provoca um estranhamento entre subjetividade e corpo, identidade e linguagem que, em consequência, instaura uma escrita da deriva. A dimensão da deriva passa a ser encenada por meio da articulação entre a tradição literária e a fratura causada na linguagem pelo contato com o residual. Nesse movimento, a obra de Nuno Ramos abandona a noção tradicional de realismo e representação em nome da teatralização dessa mesma tradição e da própria escrita. Seguindo estes caminhos de reflexão, buscarei retratar os aspectos abordados pela obra de Nuno Ramos dentro de uma perspectiva da literatura brasileira contemporânea que ressignifica questões de fundo problematizadas pela tradição literária brasileira e por precursores da estética contemporânea, como Clarice Lispector.
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A comparison between experimental measurements and numerical calculations of the ion current distribution in plasma immersion ion implantation (PIII) with external magnetic field is presented. Later, Silicon samples were implanted with nitrogen ion to analyze the effect on them. The magnetic field considered is essentially non-uniform and is generated by two magnetic coils installed on vacuum chamber. The presence of both, electric and magnetic field in PIII create a crossed ExB field system, promoting drift velocity of the plasma around the target. The results found shows that magnetized electrons drifting in ExB field provide electron-neutral collision. The efficient ionization increases the plasma density around the target where a magnetic confinement is formed. As result, the ion current density increases, promoting significant changes in the samples surface properties, especially in the surface wettability.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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[EN] Habitats dominated by algal canopies are often altered by physical disturbances of varying severity, changing environmental conditions and biological processes. We used Artificial Seaweed Units (ASUs) to test whether severity of physical disturbances on algal canopies affects the post-disturbance colonization of gastropods on subtidal reefs. Specifically, we examined patterns of assemblage structure of gastropods to test the hypothesis that the extent and intensity of canopy removal affects the post-disturbance colonization of ASUs, testing the consistency of these effects among four regions encompassing a 68 latitudinal gradient in southwestern Australia. Because adjacent habitats can act as a source of new colonists (either as drifting migrants or as a source of propagules) from the perimeter surrounding perturbed areas, we also predicted that patterns of colonization (types and total abundances of colonizers) were influenced by the available pool of individuals at the scale of reefs. Three reefs were selected within each region. On each reef, ASUs were placed in the centre of circular canopy clearings of different size (0, 3, 13 and 50 m2) and intensity (50% vs 100%), and retrieved after 3 months. Resulting assemblages occupying the ASUs were quantitatively representative of the adjacent (undisturbed), algal-associated, assemblages at the scale of reef. Within reefs, recruited assemblages largely mimicked those associated with erect red algae. However, neither disturbance size nor intensity affected the colonization patterns across reefs and regions. These results suggest that algal-associated gastropods, regardless of the prevalent mode of dispersion, are resilient to physical disturbances to canopies across broad geographical regions as long as the pool of potential colonists is maintained. A high dispersal ability of gastropods likely ensures a quick colonization of recovering algal habitats.
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[EN]The lagrangian evolution of 4 months old anticyclonic intrathermocline eddy of the Canary Eddy Corridor is investigated from the trajectories of 5 satellites tracked drifting buoys. Buoys were drogued below and above the Ekman depth at 15 m and 100 m, respectively. One buoy remained inside the eddy during almost 4 months being thus a long lived coherent feature with a life span of at least 8 months. The eddy consisted in a central core rotating in solid body rotation with a rather constant periodicity of 4 days and in an outer ring rotating much more slowly with periodicities between 8 and 12 days…
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[EN]The capacity of the ocean to sequester atmospheric carbon (CO2) depends to a large extent on the dynamics of biogenic carbon in the water column. However, most current global and regional estimates of carbon balances are solely based on particles collected with drifting and moored sediment traps. As a consequence, construction of ocean carbon budgets has long been guided by the simplification introduced by sediment traps, which give a 1D vision of the whole picture. In this thesis we have assessed a quantitative analysis of the flux magnitude and the mechanisms of transport of the whole particle spectrum (suspended, slowly-sinking and sinking particles).