931 resultados para basin listing
Resumo:
High-resolution numerical model simulations have been used to study the local and mesoscale thermal circulations in an Alpine lake basin. The lake (87 km(2)) is situated in the Southern Alps, New Zealand and is located in a glacially excavated rock basin surrounded by mountain ranges that reach 3000 m in height. The mesoscale model used (RAMS) is a three-dimensional non-hydrostatic model with a level 2.5 turbulence closure scheme. The model demonstrates that thermal forcing at local (within the basin) and regional (coast-to-basin inflow) scales drive the observed boundary-layer airflow in the lake basin during clear anticyclonic summertime conditions. The results show that the lake can modify (perturb) both the local and regional wind systems. Following sunrise, local thermal circulations dominate, including a lake breeze component that becomes embedded within the background valley wind system. This results in a more divergent flow in the basin extending across the lake shoreline. However, a closed lake breeze circulation is neither observed nor modelled. Modelling results indicate that in the latter part of the day when the mesoscale (coast-to-basin) inflow occurs, the relatively cold pool of lake air in the basin can cause the intrusion to decouple from the surface. Measured data provide qualitative and quantitative support for the model results.
Options listing and the volatility of the underling asset: a study on the derivative market function
Resumo:
There are basic misunderstandings on derivative markets. Some professionals believe that they are a kind of casinos and have no utility for the investors. This work looks at the effects of options introduction in the Brazilian market, seeking for another benefit for this introduction: changes in the stocks risk leveI. Our results are the same found in the US and other markets: the options introduction reduces the stocks volatility. We also found that there is a slight indication that the volatility becames more stochastic with this alternative.
Resumo:
This article compares capital budgeting techniques employed in listed and unlisted companies in Brazil. We surveyed the Chief Financial Officers (CFOs) of 398 listed companies and 300 large unlisted companies, and based on 91 respondents, the results suggest that the CFOs of listed companies tend to use less simplistic methods more often, for example: NPV and CAPM, and that CFOs of unlisted companies are less likely to estimate the cost of equity, despite being large companies. These findings indicate that stock exchange listing may require greater sophistication of the capital budgeting process.
Resumo:
This study on middle Miocene Charophytes from the Tagus'basin indicates the presence of two species. hitherto undescribed from these strata in Portugal, Correlation diagrams of height and width of gyrogonite demonstrate that the populations of Nitellopsis (Tectochara) etrusca from the localities Póvoa de Santarém and Pêro Filho are identical to that from La Grenatière (Hérault, France), The population of Lychnothamnus duplicicarinatus from Tremês is identical to that already known from Anwill (Switzerland). The age of this flora is therefore suggested as being the upper part of the middle Miocene. The results of Charophyte studies are in accordance with stratigraphical conclusions from previously conducted mammalian studies (Antunes and Mein), A table showing the distribution of species in the three portuguese localities is given.
Resumo:
The lignite-clays of Póvoa de Santarém dated as Upper «Vindobonian» (mammalian zone MN6), fielded abundant remains of animals and plants (spores, pollens, seeds, etc.). The forms identified are indicative of several environments. Plants, either aquatic or belonging to swampy areas are predominant (Nuphar sp., Sparganium sp., Stratiotes kaltennordheimensis, cf. Ranunculus sp.). There are also remains of plants characteristiques of a humid rather than a swampy soil such as Polypodiaceae, Myrica ceriferiformis, Toddalia maii, Spirematospermum wetzeleri. The genera Vitis and Ephedra, although rare, point fowards the existence of drier regions in the neighbourhood. The presence of polens such as Picea indicate the presence at some distance less warm upland forest areas.
Resumo:
The Upper Jurassic evolution of the Lusitanian Basin is shown to be linked to the rifting phase which preceded the separation of Iberia and the Grand Banks. Structural controls on sedimentation include both NNE-SSW trending faults in the Hercynian basement, and contemporaneous movement of salt diapirs. At the beginning of Upper Oxfordian times, the entire basin had been levelled to within a few metres of sea level, so that the freshwater algal marsh and marginal marine facies of the Cabaços and Vale Verde Beds rest on Triassic to Callovian strata. In the latter part of the Upper Oxfordian. carbonate sedimentation continued, with fluctuating salinity lagoons in the north (Pholodomya protei Beds) separated from shallow open marine carbonates in the south (Montejunto Beds) by the Caldas da Rainha diapir-barrier island complex. The commencement of rifting is recorded in the Kimmeridgian by the sudden influx of terrigenous clastics (developed in both fluviatile and deltaic/submarine fan environments) and accelerated depositional rates in excess of 10cm/10 k.yrs in association with contemporaneous faulting along the SE margin of the Arruda sub-basin. The Caldas-Santa Cruz chain of diapiric structures continued to influence the distribution of carbonate and clastic sediments. In the Portlandian, a simpler facies pattern occurs, with fluviatile clastics interfingering to the south with shallow low energy carbonates.
Resumo:
This study on middle Miocene Charophytes from the Tagus' basin indicates the presence of two species, hitherto undescribed from these strata in Portugal. Correlation diagrams of height and width of gyrogonite demonstrate that the populations of Nitellopsis (Tectochara) etrusca from the localities Póvoa de Santarém and Pêro Filho are identical to that from La Grenatière (Hérault, France), The population of Lychnothamnus duplicicarinatus from Tremês is identical to that already known from Anwill (Switzerland). The age of this flora is therefore suggested as being the upper part of the middle Miocene. The results of Charophyte studies are in accordance with stratigraphical conclusions from previously conducted mammalian studies (Antunes and Mein). A table showing the distribution of species in the three portuguese localities is given.
Resumo:
The lignite-clays of Póvoa de Santarém dated as Upper «Vindobonian» (mammalian zone MN6), fielded abundant remains of animals and plants (spores, pollens, seeds, etc.). The forms identified are indicative of several environments. Plants, either aquatic or belonging to swampy areas are predominant (Nuphar sp., Sparganium sp., Stratiotes kaltennordheimensis, cf. Ranunculus sp.). There are also remains of plants characteristiques of a humid rather than a swampy soil such as Polypodiaceae, Myrica ceriferiformis, Toddalia maii, Spirematospermum wetzeleri. The genera Vitis and Ephedra, although rare, point fowards the existence of drier regions in the neighbourhood. The presence of polens such as Picea indicate the presence at some distance less warm upland forest areas.
Resumo:
Forty-five species of ostracoda from the Aquitanian of the Lisbon area, belonging in thirty-two genera, are presented. These are the first species belonging to this group reported for the Miocene formations in Portugal. Ostracoda assemblages are typical of fresh water, brackish and marine environments (littoral and inner continental shelf). References are made to the stratigraphically more significant species. Data on the paleoenvironments are also presented. A list of the studied species includes a comparison with their distribution in the Aquitaine and Rhone Miocene basins.
Resumo:
Twelve new species of miocene ostracoda from the Tagus basin (Portugal) are described. Paleoenvironments concerning each of these species are given.
Resumo:
Revista Española de Paleontologia 19 (2), 229-242
Resumo:
Revista electrónica de Ciências da Terra,http://e-terra.geopor.pt,Geociences on-line journal, Vol. 6, nº1
Resumo:
Dissertação apresentada para a obtenção do grau de Doutor em Conservação e Restauro pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia
Resumo:
Rev. Soc. Geol. España, 12(1), ano 1999