Interaction of Tidal and Fluvial Processes in the Transition Zone of the Santee River, SC, USA     

Alexander E. Yankovsky  Raymond Torres  Legna M. Torres-Garcia  Kyungho Jeon 《Estuaries and Coasts》2012,35(6):1500-1509

This study was conducted in the freshwater reach of the Santee River approximately 55?±?4?km from the mouth, a transition zone from a fluvial to an estuarine tidal regime. The dataset comprises bathymetric surveys, current profile and bottom pressure measurements at two locations, and time series of discharge. Our data indicate that the transition zone is characterized by strong tidal dissipation and distinctive channel geometry. Tidal dissipation is evident in the rapid decrease of the M₂ amplitude to the mean along-channel velocity ratio from 2.1 to 0.9 over a ??6-km distance. Channel cross-sectional area in the transition zone converges at a higher rate than both upstream and downstream while channel depth reveals threefold variations in the form of adjacent shoals and deeps. We hypothesize that the enhanced tidal dissipation is at the same time a cause and a result of strongly convergent bathymetry in the transition zone.  相似文献   

The First DIRECT Distance to a Detached Eclipsing Binary in M33     

A. Z. Bonanos  K. Z. Stanek  R. P. Kudritzki  L. Macri  D. D. Sasselov  J. Kaluzny  D. Bersier  F. Bresolin  T. Matheson  B. J. Mochejska  N. Przybilla  A. H. Szentgyorgyi  J. Tonry  G. Torres 《Astrophysics and Space Science》2006,304(1-4):207-209

We present the first direct distance determination to a detached eclipsing binary in M33, which was found by the DIRECT Project. Located in the OB 66 association, it was one of the most suitable detached eclipsing binaries found by DIRECT for distance determination, given its 4.8938 day period. We obtained follow-up BV photometry and spectroscopy from which we determined the parameters of the system. It contains two O7 main sequence stars with masses of and and radii of and , respectively. We derive temperatures of K and K and determine the reddening . Using HST photometry for flux calibration in the V band, we obtain a preliminary distance modulus of mag ( kpc). The photometry and thus distance is subject to revision in the final paper.  相似文献   

Rocky-shore communities as indicators of water quality: a case study in the Northwestern Mediterranean     

Pinedo S  García M  Satta MP  de Torres M  Ballesteros E 《Marine pollution bulletin》2007,55(1-6):126-135

The collection of 152 samples from the upper sublittoral zone along the rocky coasts of Catalonia (Northwestern Mediterranean) was carried out in 1999 in order to test the suitability of littoral communities to be used as indicators of water quality in the frame of the European Water Framework Directive. Detrended correspondence analysis were performed to distinguish between different communities and to relate communities composition to water quality. Samples collected in reference sites were included in the analysis. Mediterranean rocky shore communities situated in the upper sublittoral zone can be used as indicators of the water quality: there is a gradient from high to bad status that comprises from dense Cystoseira mediterranea forests to green algae dominated communities. The geographical patterns in the distribution of these communities show that the best areas are situated in the Northern coast, where tourism is the main economic resource of the area, and the worst area is situated close to the metropolitan zone of Barcelona with high population and industrial development. Thus, Mediterranean sublittoral rocky shore communities are useful indicators of water quality and multivariate analysis are a suitable statistical tool for the assessment of the ecological status.  相似文献   

The η Carinæ optical 2009.0 event,a new “eclipse-like” phenomenon     

E. Fernández-Lajús  C. Fariña  J.P. Calderón  N. Salerno  A.F. Torres  M.A. Schwartz  C. von Essen  F. Giudici  F.A. Bareilles 《New Astronomy》2010,15(1):108-112

  相似文献   

The impact of a merger episode in the galactic disc white dwarf population     

Santiago Torres  Enrique García-Berro  reas Burkert  Jordi Isern 《Monthly notices of the Royal Astronomical Society》2001,328(2):492-500

In this paper we analyse the consequences in the white dwarf population of a hypothetical merger episode in our Galactic disc. We have studied several different merging scenarios with our Monte Carlo simulator. For each one of these scenarios we have derived the main characteristics of the resulting white dwarf population and we have compared them with the available observational data, namely the white dwarf luminosity function and the kinematic properties of the white dwarf population. Our results indicate that very recent (less than ∼6 Gyr ago) and massive (∼16 per cent of the mass of our Galaxy) merger episodes are quite unlikely in view of the available kinematical properties of the disc white dwarf population. Smaller merger episodes (of the order of ∼4 per cent of the mass of our Galaxy) are, however, compatible with our current knowledge of those kinematical properties. Finally, we prove that the white dwarf luminosity function is quite insensitive to such a merger episode.  相似文献   

Lessons from co-impacts assessment under the Mitigation Action Plans and Scenarios (MAPS) Programme     

Brett Cohen  Emily Tyler  Marta Torres Gunfaus 《Climate Policy》2013,13(8):1065-1075

The MAPS Programme has been active in Brazil, Chile, Colombia and Peru in supporting the development of an evidence base to inform the processes involved in climate mitigation policy-making. The programme combines detailed quantitative analysis with an extensive stakeholder engagement process to provide policy and decision makers with the information required for long-term climate mitigation planning.

In recognition of the critical need to consider the developmental context and agenda in climate policy-making, the projects undertaken in these countries have experimented with various types of assessments of developmental impacts at both the macro and micro levels. These impacts have been collectively termed co-impacts to reflect the fact that these may be either positive or negative. In this article the value and challenges associated with co-impacts work for climate mitigation policy are considered. The value of including co-impacts analysis in the MAPS processes included increased stakeholder buy-in, making the case for mitigation action, informing INDCs and the prioritization of particular mitigation actions. Challenges include those associated with obtaining locally relevant data, the selection and operation of appropriate macro-economic models and analytical approaches and working with multidisciplinary teams.

The article concludes by making some suggestions to optimize co-impacts work, through reference to other bodies of literature. The authors highlight that this article is situated within a dominant approach to climate mitigation policy work in developing countries, which implicitly places the non-climate benefits of any action as secondary to the primary benefit of climate change mitigation and constructs an artificial separation of policy formulation and implementation. Practitioners are encouraged to reflect on the implications of these considerations in future efforts.

Policy relevance

One of the primary challenges to advancing climate mitigation policy in developing countries is that of perceived relevance: near-term development priorities are overwhelming. Identifying, understanding and engaging with the co-impacts of mitigation actions has emerged as one way of addressing this challenge. Although still at an experimental phase, experience with co-impacts analysis in the MAPS countries provides some useful lessons in how to develop this area of work.  相似文献   

A global analysis of austral summer ocean wave variability during SAM–ENSO phase combinations     

Victor A. Godoi  Audalio R. Torres J&#;nior 《Climate Dynamics》2020,54(9):3991-4004

Anticipating and mitigating wave-related hazards rely heavily on understanding wave variability drivers. Here, we describe wave conditions related to concurrent Southern Annular Mode (SAM) and El Niño–Southern Oscillation (ENSO) phases during the austral summer. To identify such conditions, significant wave height (Hs) and peak wave period (Tp) daily anomalies were composited during different SAM–ENSO phase combinations over the last four decades (1979–2018). Surface wind anomalies were also composited to assist in the interpretation of wave conditions. The composites show significant wave variability across all ocean basins and in several semi-enclosed seas throughout the different SAM–ENSO phase combinations. The Southern, Indian, and Pacific Oceans generally experience the strongest Tp anomalies during combinations of SAM phases with El Niño, and the weakest Tp anomalies during combinations of SAM phases with La Niña. The anomalously large waves observed in the south-western Pacific, Tasman Sea, and the Southern Ocean, previously ascribed to ENSO conditions, seem to be instead associated with the SAM variability. SAM-related atmospheric conditions are found to be able to modulate the intensity of ENSO-related winds over the South China Sea, which, in turn, alter the magnitude of waves in that region. These and other wave anomaly structures described here, especially those contrasting the behaviour expected for a given ENSO phase, such as the one found along the California coast, stress the importance of understanding relationships between wave parameters and climate patterns interactions.  相似文献   

Response surface methodology for lead biosorption on Aspergillus terreus     

F. J. Cerino Córdova Ph.D.  A. M. García León Ph.D.  R. B. Garcia Reyes Ph.D.  M. T. Garza González Ph.D.  E. Soto Regalado Ph.D.  M. N. Sánchez González Ph D.  I. Quezada López 《International Journal of Environmental Science and Technology》2011,8(4):695-704

A central composite face-centered design was used to study and to optimize lead biosorption from aqueous solution on Aspergillus terreus biomass. Four factors such as stirring speed, temperature, solution pH and biomass dose at different levels were studied.The hierarchical quadratic model were established by adding replicates at the central point and axial points to the initial full factorial design (2⁴). The percentage removal of lead was affected by biomass dose, pH, and interactions between pH and biomass dose, pH and stirring speed, pH and temperature. The hierarchical quadratic model described adequately the response surface based on the adjusted determination coefficient (R² _Adj= 0.97) and the adequate precision ratio (42.21). According to this model, the optimal conditions to remove lead completely from aqueous solutions (at initial lead concentration of 50 mg/L and solutions of 100 mL) with Aspergillus terreus were at pH 5.2, 50 °C, stirring speed of 102/min and a biomass dose of 139 mg.The response surface methodology can be used to determine the optimal conditions for metal adsorption on several adsorbents. In addition, results reported in this research demonstrated the feasibility of employing A. terreus as biosorbent for lead removal.  相似文献   

Electromagnetic radiation from a source at the center of a static charged dust sphere     

L. F. Bloomfield Torres  J. A. Souza 《Astrophysics and Space Science》1993,204(1):1-8

Using Maxwell equations in a background metric discovered by Bonnor, which describes the gravitational field generated by an optimally charged dust ball, we calculate the external radiation field from an electric dipole source at the center the ball. Possible applications to stellar mode 1 s are discussed in the conclusions.  相似文献   

Time-resolved spectroscopy of the M15 X-ray binary AC211/X2127+119     

M. A. P. Torres  P. J. Callanan  M. R. Garcia 《Monthly notices of the Royal Astronomical Society》2003,341(4):1231-1238

  相似文献