On the Use of Random Material in Dam Cores: Case of the Manso Dam,Brazil     

Ferreira  Breno S.  Almeida  Marcio S. S.  Lopes  Francisco R.  Reis Cavalcanti  Maria do Carmo  Pires Filho  Celso José 《Geotechnical and Geological Engineering》2022,40(4):1973-1987

Geotechnical and Geological Engineering - The Manso Dam, in the Brazilian State of Mato Grosso, intended for flood control and electricity generation, was built by a state-owned energy company in...  相似文献   

Volcanism–sedimentation interaction in the Campo de Calatrava Volcanic Field (Spain): a magnetostratigraphic and geochronological study     

Antonio Herrero-Hernández  Francisco Javier López-Moro  José Luis Gallardo-Millán  Ángel Martín-Serrano  Fernando Gómez-Fernández 《International Journal of Earth Sciences》2015,104(1):103-122

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Human-induced coastal landslide reactivation. Monitoring by PSInSAR techniques and urban damage survey (SE Spain)   总被引：1，自引：1，他引：0  

Davide Notti  Jorge Pedro Galve  Rosa María Mateos  Oriol Monserrat  Francisco Lamas-Fernández  Francisca Fernández-Chacón  Francisco Javier Roldán-García  José Vicente Pérez-Peña  Michele Crosetto  José Miguel Azañón 《Landslides》2015,12(5):1007-1014

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The droughts of 1997 and 2005 in Amazonia: floodplain hydrology and its potential ecological and human impacts     

Javier Tomasella  Patrícia F. Pinho  Laura S. Borma  José A. Marengo  Carlos A. Nobre  Olga R. F. O. Bittencourt  Maria C. R. Prado  Daniel A. Rodriguez  Luz A. Cuartas 《Climatic change》2013,116(3-4):723-746

It is well known that most of the severe droughts in Amazonia, such as that of 1997, are El Niño-related. However, in 2005, the Amazon was affected by a severe drought that was not El Niño-related, as most of the rainfall anomalies that have happened in southwestern Amazonia are driven by sea surface temperature anomalies in the tropical North Atlantic. Earlier studies have analyzed both droughts in terms of their meteorological causes and impacts in terra firme (non-flooded) forests. This study compares the hydrological effects of both droughts on the Amazonian floodplain and discusses their potential ecological and human impacts based on an extensive literature review. The results revealed that the effects of the 2005 drought were exacerbated because rainfall was lower and evaporation rates were higher at the peak of the dry season compared to the 1997 drought. This induced a more acute depletion of water levels in floodplain lakes and was most likely associated with higher fish mortality rates. Based on the fact that the stem growth of many floodplain species is related to the length of the non-flooded period, it is hypothesized that the 1997 drought had more positive effects on floodplain forest growth than the 2005 drought. The fishing community of Silves in central Amazonia considered both droughts to have been equally severe. However, the 2005 drought was widely broadcasted by the press; therefore, the governmental mitigation efforts were more comprehensive. It is suggested that the availability of new communication technology and greater public awareness regarding environmental issues, combined with the new legal framework for assessing the severity of calamities in Brazil, are among the primary factors that explain the difference in societal response between the two droughts.  相似文献   

Modeling monthly mean air temperature for Brazil   总被引：1，自引：1，他引：0  

Clayton Alcarde Alvares  José Luiz Stape  Paulo Cesar Sentelhas  José Leonardo de Moraes Gonçalves 《Theoretical and Applied Climatology》2013,113(3-4):407-427

Air temperature is one of the main weather variables influencing agriculture around the world. Its availability, however, is a concern, mainly in Brazil where the weather stations are more concentrated on the coastal regions of the country. Therefore, the present study had as an objective to develop models for estimating monthly and annual mean air temperature for the Brazilian territory using multiple regression and geographic information system techniques. Temperature data from 2,400 stations distributed across the Brazilian territory were used, 1,800 to develop the equations and 600 for validating them, as well as their geographical coordinates and altitude as independent variables for the models. A total of 39 models were developed, relating the dependent variables maximum, mean, and minimum air temperatures (monthly and annual) to the independent variables latitude, longitude, altitude, and their combinations. All regression models were statistically significant (α?≤?0.01). The monthly and annual temperature models presented determination coefficients between 0.54 and 0.96. We obtained an overall spatial correlation higher than 0.9 between the models proposed and the 16 major models already published for some Brazilian regions, considering a total of 3.67?×?10⁸?pixels evaluated. Our national temperature models are recommended to predict air temperature in all Brazilian territories.  相似文献   

Investment risk and return under renewable decarbonization of a power market     

José I. Muñoz 《Climate Policy》2013,13(2):87-105

How does financial performance risk affect investments in low-carbon electricity-generating technologies to achieve climate policy targets? A detailed risk simulation of price formation in the Great Britain wholesale power market is used to show that the increasing replacement of fossil facilities with wind, ceteris paribus, may cause a deterioration of the financial risk–return performance metrics for incremental investments. Low-carbon investments appear to be high risk, low return, and as such may require a progressively higher level of support over time than envisaged by the conventional degression trajectories. The increasing riskiness of the wholesale market will to some extent offset the benefits of lower capital costs and operational efficiencies if investors need to satisfy cautious debt coverage ratios alongside positive expected returns. This increased risk is additional to the well-known ‘merit order effect’ of low-carbon investments progressively depressing wholesale prices and hence their expected investment returns.

Policy relevance

Policy support for renewable technologies such as wind is usually based upon levelized costs and is expected to reduce over time as capital costs and operational efficiencies improve. However, levelized costs do not take full account of the risk aversion that investors may have in practice. Expected policy support reductions may be moderated to some extent by the increased financial performance risk that intermittent technologies bring to the power market. The annual risk-return profiles for incremental investments deteriorate for all technologies as wind replaces fossil fuels. This extra risk premium will need to be incorporated into evaluating policy incentives for new investments in a decarbonizing power market.  相似文献   

Behaviour of the SMF method for the numerical integration of satellite orbits     

Pablo Martín  José M. Ferrándiz 《Celestial Mechanics and Dynamical Astronomy》1995,63(1):29-40

The SMF algorithms were recently developed by the authors as a multistep generalization of the ScheifeleG-functions one-step method. Like the last, the proposed codes integrate harmonic oscillations without truncation error and the perturbing parameter appears as a factor of that error when integrating perturbed oscillations. Therefore they seemed to be convenient for the accurate integration of orbital problems after the application of linearizing transformations, such as KS or BF. In this paper we present several numerical experiments concerning the propagation of Earth satellite orbits, that illustrate the performance of the the SMF method. In general, it provides greater accuracy than the usual standard algorithms for similar computational cost.  相似文献   

A New Symbolic Processor for the Earth Rotation Theory     

Juan F. Navarro  José M. Ferrándiz 《Celestial Mechanics and Dynamical Astronomy》2002,82(3):243-263

In this paper we present a new symbolic processor specially suited for the Earth rotation theory. This processor works with a more general kind of Poisson series called Kinoshita series, which has resulted to be very useful in the Earth rotation theory. Its structure is adapted for dealing with the more general analytical expressions that appear in the Earth rotation theory. This new algebraic processor has been successfully used for computing different contributions to the nutation series of the rigid Earth.This revised version was published online in October 2005 with corrections to the Cover Date.  相似文献   

Orbital Elements of 2004 Perseid Meteoroids Perturbed by Jupiter     

Josep Maria Trigo-Rodriguez  Jeremie Vaubaillon  José Luís Ortiz  Alberto Castro-Tirado  Jordi Llorca  Esko Lyytinen  Martin Jelínek  Antonio de Ugarte Postigo  Pablo Santos Sanz  Francisco J. Aceituno Castro  Albert Sánchez Caso  Antonio Bernal González  Juan Pastor Erades  Francisco Ocaña 《Earth, Moon, and Planets》2005,97(3-4):269-278

Jupiter and Saturn produce important gravitational impulses on meteoroids released by comet 109P/Swift-Tuttle. The meteoroids from this comet once released follow retrograde orbits that during their periodic approaches to these planets (within 1.6 and 0.9 A.U., respectively) are impulsed gaining orbital energy. This perturbation effect is translated into a net inward shift in the node of the perturbed meteoroids. Such geometry with Jupiter occurred in 2004 over a meteoroid trail ejected by this comet during the 1862 A.D. return of the comet to perihelion. In order to study the predicted outburst produced by one-revolution meteoroids, the Spanish Photographic Meteor Network (SPMN) performed an extensive campaign. As a part of this observational effort here are presented 10 accurate meteoroid orbits. We discuss their origin by comparing them with the theoretical orbital elements of the dust trails intercepting the Earth during the 2004 Perseid return.  相似文献   

Light curves of the eclipsing systems of RS CVn-type     

María Lina Berríos-Salas  Margarita Guzmán-Vega  José Fernández-Labra  Manlio Maldini-Sánchez 《Astrophysics and Space Science》1989,162(2):205-209

This work presents the light curves for rotating spotted stars generated by a computational code developed by us. This code is based in a model of the system and its analytical solution. The work also present an analysis of the photometric curve variations with the changes in the model's parameters.As a first result we have simulated a temporal evolution of the light curve when the photospheric spot varies its size and position and we reproduced some observational light curves of the II Peg star.Work supported by Dirección de Investigación, Universidad de La Serena, Chile.  相似文献