9,663 research outputs found
Tidal dynamics on the North Patagonian Argentinean Gulfs
Semidiurnal (M2, S2, N2 and K2), diurnal (K1,O1 and P1) and quarter-diurnal (M4, MN4 and MS4) barotropic tides over the North Patagonian Gulfs of Argentina: San MatĂas, (SMG), Nuevo (NG) and San JosĂ© (SJG) are examined using a regional numerical model. Detailed comparison of computed elevations and currents with those obtained from harmonic analysis of few long-term observational records showed good agreement. A large amplification of all semidiurnal waves is recorded when they cross SMG mouth. Most of the tidal energy coming from the south at this frequency dissipates to the northeast of ValdĂ©s PenĂnsula, where the largest tidal currents are located. While M2 currents (up to 2–2.5 m/s) are dominant, there are large S2 and N2 currents and locally intensified diurnal currents (5–10 cm/s) in some outer shelf locations. At difference with the semidiurnal and diurnal tides the higher harmonics M4, MS4 and MN4 develop a large amplification inside the NG. The model revealed a complex field of tidal residual currents. The intensity of such currents in some locations are of the same order of magnitude as those generated by winds or offshore forcing. We have identified three main patterns of residual circulation: regional coastal currents and gulf-wide gyres; inlet eddies and, topographic eddies. Vorticity balances and sensitivity experiments indicate that non-linear advection and bottom topography are the key mechanisms involved in the generation of these residual structures.Fil: Tonini, Mariano Hernan. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro Nacional PatagĂłnico; ArgentinaFil: Palma, Elbio Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Instituto Argentino de OceanografĂa. Universidad Nacional del Sur. Instituto Argentino de OceanografĂa; Argentina. Universidad Nacional del Sur. Departamento de FĂsica; Argentin
The species composition and nutrition of dominant species of fish of Absheron Gulfs of the Caspian Sea
The analysis of net catches made in Absheron Gulfs of the Caspian Sea during 2011-2012 is provided. The ichthyofauna of Absheron Gulfs, including 26 species found in the North Gulf, and 33 species and subspecies found in the South Gulf was studied for the first time. A taxonomical and ecological diversity of the fish fauna of North and South Absheron Gulfs is characterized. The peculiarities of distribution and population densities of all species of fishes from different families within the studied territories were analyzed. For each of hydrological seasons, numerous, common, infrequent and rare species were revealed. On migration patterns and catch, the lowest biomass of fishes was observed in the warm season, while the highest was in the winter and spring seasons. The tendency of expansion of ranges of some marine fishes - Gasankuli herring Alosa braschnikowi kisselewitschi, Sara herring A. braschnikowi sarensis, big-eyed herring A. braschnikowi autumnalis, Sara shad A.caspia knipowitschi - to the north was recorded
Coastal zone water quality: Calibration of a water-turbidity equation for MODIS data
A nephelometric turbidity algorithm has been specifically calibrated for coastal waters in Sicily. To this purpose, intensive field campaigns were performed in July, August and September 2008. Measurements were collected in situ in three different gulfs. Statistical analysis suggests that field data should be spatially grouped but temporally separated; hence, new calibration parameters have been proposed. Turbidity retrieved by applying the algorithm using literature coefficients and the ones calibrated in situ are shown and compared. The comparison demonstrated that a specific calibration was necessary for quantitatively monitoring turbidity in Sicilian gulfs
Foreword
This report provides a study and a simulation of a feasible system configuration for the implementation of a Stirling engine for electrification of rural areas in Bolivia. The aim of the review is to determine if a hybrid system combining a biomass-fired Stirling engine and photovoltaic technology may respond to a basic electricity need. An introductory literature study about the Stirling engine technology and the energy resources and characteristics of Bolivia leads to a further proposal of the selected system for rural electrification. The chosen Stirling engine for this study is a 3 kW electric output engine combined with a PV array of 0.9 kW and a battery bank with a capacity of 1200 Ah. The power demand that must be satisfied is based on a rural village in the department of Beni with an amount of 24 households. The simulation is performed in the software Homer Energy where an energy balance between the generated power and the demand can be analysed in order to optimise the power generation strategy. Two scenarios are simulated with monthly demands of 45 and 60 kWh per household. Results from the study indicate that the decision on the size of the Stirling engine must be attached to the demand that is going to satisfy in order to avoid insufficient or excessive power production. In addition, although the PV technology allows an increase on the power demand that the system can handle and makes it more flexible, its contribution is not of the same order of the Stirling engine. The described system configuration is able to attend a demand up to 55 kWh/day and a peak power of 3.8 kW. In conclusion, Stirling engines have the potential to become a good solution for rural electrification, especially when making use of CHP strategies to increase the overall efficiency of the energy generation and fulfil both the electric and thermal demands of rural populations.
Towards engineering ontologies for cognitive profiling of agents on the semantic web
Research shows that most agent-based collaborations
suffer from lack of flexibility. This is due to the fact that
most agent-based applications assume pre-defined
knowledge of agents’ capabilities and/or neglect basic
cognitive and interactional requirements in multi-agent
collaboration. The highlight of this paper is that it brings
cognitive models (inspired from cognitive sciences and HCI)
proposing architectural and knowledge-based requirements
for agents to structure ontological models for cognitive
profiling in order to increase cognitive awareness between
themselves, which in turn promotes flexibility, reusability
and predictability of agent behavior; thus contributing
towards minimizing cognitive overload incurred on humans.
The semantic web is used as an action mediating space,
where shared knowledge base in the form of ontological
models provides affordances for improving cognitive
awareness
The Reef-fish Fauna of the Northern Patagonian Gulfs, Argentina, South-western Atlantic
A checklist containing 29 species of reef fishes recorded at the gulfs San JosĂ© and Nuevo in Argentina (42°-43°S) is provided. The reef-fish assemblages of the San JosĂ© and Nuevo gulfs are a mix of warm-temperate fauna from the South-western Atlantic Province, and cold-temperate species from the South-American Province; however, warm-temperate fishes dominated in both gulfs. The presence of the families Bovichtidae, Eleginopidae, Nototheniidae, Congiopodidae, Sebastidae and Moridae distinguished the Patagonian region from the rest of the Atlantic coast.Fil: Galvan, David Edgardo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Centro Nacional PatagĂłnico; ArgentinaFil: Venerus, Leonardo Ariel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Centro Nacional PatagĂłnico; ArgentinaFil: Irigoyen, Alejo Joaquin. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Centro Nacional PatagĂłnico; Argentin
Jenny Jones: “my vision for London is of a more sustainable, fairer and cleaner city”
Green Party candidate for London Mayor Jenny Jones details her proposals to encourage a 10:1 ratio of company pay, to boost contracts to smaller firms through her mayoral office and how Londoners could have a safer and healthier life in the city. This is the third in a three part series with the mayoral candidates, including Brian Paddick and Ken Livingstone, with an introduction by Tony Travers
Not Burns – Duncan Ban MacIntyre and his Gaelic manifesto for land reform
No abstract available
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