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21.
Flume experiments with a scale-model of a wave driven seawater pump in monochromatic waves are described. A tuning mechanism optimises the pump performance by keeping it at resonance with the waves. The pumping process itself was found to de-tune the system because of the reduced gravity restoring force due to spilling in the compression chamber. A perturbation analysis of the pump equations shows that performance of the system can be increased by optimising the shape of the pump intake to minimise losses due to vortex formation. An algorithm is derived, using a numerical model of the pump, which accurately determines the required volume of air in the compression chamber to induce resonance given variations in the wave frequency, the wave height and the tides. A sustainable development project to use a seawater pump to manage fisheries at a coastal lagoon in Mexico is described. 相似文献
22.
César Augusto Moreira Antonio Celso de Oliveira Braga Letícia Hirata Godoy Diego de Sousa Sardinha 《Geofísica Internacional》2013,52(4):375-383
The geophysical methods are effective tools for determining changes in physical parameters of the geological environment, as soil or groundwater in the presence of contamination. This work consisted on analyzing the natural electric potential obtained over domestic solid waste ditches with controlled closure dates. The interpretation data suggest the generation of electric potential predominantly through the redox phenomenon, as opposed to the flow potential phenomenon. The statistical data analysis indicates a correlation between residence time of the waste and growing variations of voltage. In addition highlights that eight years are required to achieve the reported values for the area with absence of waste, time estimated for decomposition of most organic matter contained in the buried waste. 相似文献
23.
Julio Godoy John Atkinson 《International journal of geographical information science》2013,27(1):149-170
Geo-referencing is a key task for geographical information retrieval because it allows unstructured or textual documents (i.e., Web pages) to be associated with geographical locations, which are then used by geo-search engines to index documents and search information by spatial criteria. This work proposes a strategy to extract geo-references from textual documents that combine natural language-processing techniques and co-reference solving heuristics, which in turn can be used to expand a geographical gazetteer. Implicit geographical entities (i.e., those entities referred to by pronouns) are recognized and incorporated into the gazetteer that is updated and used for geo-referencing tasks. Experiments show the promise of the approach to geo-referencing Web pages when dealing with implicit and/or indirect geo-references. 相似文献
24.
M.C. Geraldes A.H. Paula J.M. Godoy C.M. Valeriano 《Journal of Geochemical Exploration》2006,88(1-3):384
Sediments from Guanabara Bay and two rivers were analyzed for Pb isotope composition. The results define linear groups interpreted as different sources of Pb. The samples from Iriri and Surui rivers present different Pb compositions probably resulting from two active pollutants which are transported in the waters to the Guanabara Bay, where they are mixed. The 206Pb/207Pb values of 1.151 and 1.091 presented here are in the range of Brazilian galena ore signature. 相似文献
25.
Despite being endangered internationally and protected nationally, little consideration has been given to the occurrence of green turtles (Chelonia mydas) in New Zealand. New Zealand lies on the southern boundary of the distributional range of green turtles in the southwestern Pacific, with individuals found within these waters historically considered to be occasional visitors or stragglers incidentally carried by ocean currents. However, the present work shows that green turtles are present year round in New Zealand’s northern waters (c. 34°–38° S). A review of sighting, stranding and incidental capture data collected between 1895 and 2013 illustrate New Zealand’s green turtle population comprises post-pelagic immature juveniles to large subadults. The female:male sex ratio of 1.7:1 is similar to those reported from warm temperate foraging grounds in eastern Australia. A subsample of new recruits indicates green turtles recruit to neritic habitats at approximately 40.8?cm curved carapace length. This study suggests that New Zealand’s neritic habitats constitute a transitional developmental ground for post-pelagic immature green turtles. We observed an exponential increase in the number of documented records over time, though whether this is due to increased numbers of turtles or increased reporting rates, or both, is unclear and warrants further investigation. More broadly, this work provides a baseline understanding of the ecology of green turtles at the edge of their range, providing opportunities to investigate regional niche modelling and connectivity of this highly mobile species, while also monitoring broad-scale effects of climate-induced environmental change. 相似文献
26.
Luis A. Godoy 《Applied Ocean Research》1985,7(3):152-157
Forced vibrations of the walls of a vertical cylindrical shell under the impact of a breaking wave are studied theoretically. The wave action is modelled as a pressure distribution which varies in time and space. A linear dynamic analysis of the transient response is carried out by means of the modal superposition technique, in which the static stresses are considered. The results show that in thin shells, the transient displacements could be of the order of the thickness of the shell. It is suggested that these large displacements could play an important role in eroding the buckling capacity of the structural component. The problem of limiting the dynamic displacements is discussed by interaction diagrams for static axial load-dynamic lateral pressure, and by examination of the confluence of shell and wave parameters for which the transient displacements do not exceed a given value. 相似文献
27.
Journal of Earth System Science - Hydrological models are simplified representations of natural processes and subject to errors. Uncertainty bounds are a commonly used way to assess the impact of... 相似文献
28.
Marta M. Cassiano Pierre Kaufmann Rogério Marcon Amauri S. Kudaka Adolfo Marun Rodolfo Godoy Pablo Pereyra Arline M. Melo Hugo Levato 《Solar physics》2010,264(1):71-79
Solar observations in the mid-infrared 8 – 14 μm band continuum were carried out with cadence of 5 frames per second, in December 2007.
Rapid small heated sources, with a typical duration of the order of seconds, were found on the bright plage-like areas around
sunspots, in association with relatively weak GOES soft X-ray bursts. This work presents the analysis of fast mid-infrared
flashes detected during a GOES B2.0-class event on 10 December 2007, beginning at about 10:40 UT. Rapid brightness temperature
enhancements of 0.5 to 2.0 K were detected at the Earth by a microbolometer array, using a telescope with 10.5 cm diameter
aperture producing a diffraction-limited photometric beam of 25 arc sec. The minimum detectable temperature change was of
0.1 K. The corresponding fluxes are 30 – 130 solar flux units. At the solar surface the estimated rapid brightenings represented
a temperature enhancement of 50 – 150 K. 相似文献
29.
Stefan Gelcich Omar Defeo Oscar Iribarne Graciano Del Carpio Random DuBois Sebastian Horta Juan Pablo Isacch Natalio Godoy Pastor Coayla Pealoza Juan Carlos Castilla 《Marine Policy》2009,33(5):801-806
Ecosystem-based management (EBM) has recently received considerable attention. However, examples of empirical approaches to marine EBM are scarce. Therefore, empirical information on the presence of EBM elements within existing policies and the way they may provide settings and lessons for EBM implementation is timely. This study analyses stakeholders’ perceptions on the existence of EBM principles in current marine management practices and policies, and how they determine perceptions for success and satisfaction regarding coastal management within selected case studies drawn from four developing countries in the Southern Cone of South America. Patterns of response across study sites show that although EBM principles as such are not explicitly included in management/conservation plans, there are policies (mainly local), which generate conditions for more explicit inclusion of them. These are based on participatory bottom-up planning, place-based management and consensus reaching: all elements included within the theoretical literature on EBM implementation. 相似文献
30.
Franciane de Carvalho Gomes Jos Marcus Godoy Maria Luiza D.P. Godoy Zenildo Lara de Carvalho Ricardo Tadeu Lopes Joan Albert Sanchez-Cabeza Luiz Drude de Lacerda Julio Cesar Wasserman 《Marine pollution bulletin》2009,59(4-7):123
Three sediment cores were sampled at Sepetiba Bay and four cores at Ribeira Bay, Rio de Janeiro State, Brazil. Sediment accumulation rates and chronologies were obtained from 210Pb activity-depth profiles. Sediment accumulation rates in Ribera Bay ranged from 1.2 mm y−1 in the inner bay to 2.6 mm y−1 close to its entrance. In Sepetiba Bay two sediment accumulation rates were observed: a lower rate of 0.35 cm y−1 before the 1960s and 0.76 cm y−1 since then. The cause of this change is due to the construction of the Santa Cecília impoundment (1955) that brings water from the Paraíba do Sul Basin into the Guandu River, which increased its flow from the original 20 m3 s−1 to 160 m3 s−1. Concentration of 44 elements was obtained by ICP-MS after total dissolution of samples from two selected cores. The relative differences between the concentrations of crustal elements, such as Al, Fe and Ti are only about 20% (p < 0.05). Cd and Zn are 15 and four times larger in Sepetiba Bay than in Ribeira Bay, respectively. Other major and minor elements show lower statistically significant differences. The enrichment factors and metal inventories show that Sepetiba Bay can be considered polluted with Bi, Cd, Cr, Cu, Sb and Zn. Particularly, Cd and Zn present concentrations three and four times higher than the Brazilian existing limits. 相似文献