Dynamics of a Prorocentrum minimum bloom along the northern coast of Sinaloa,Mexico     

Aída Martínez-López  Diana Cecilia Escobedo-Urías  Ana Elsi Ulloa-Pérez  Raul Aguirre 《Continental Shelf Research》2008

To investigate the relative importance of mesoscale physical events, such as upwellings and physical and chemical variables during an algae bloom of Prorocentrum minimum, 25 sampling sites were established offshore of the Navachiste Lagoon Complex on the east side of the Gulf of California. Samples were analyzed for phytoplankton concentration, water chemistry, and temperature during November 1999, January, March, April, May, and August 2000. Satellite imagery of sea surface temperature (SST) for April 2000 was processed to obtain a synoptic view of the area during the extraordinary bloom of P. minimum in the open waters of the Gulf of California. The bloom was associated with change of oceanographic conditions from moderate winds to calm period, temperature increase and high nitrate (NO₃⁻-N) and ammonia (NH₄⁺-N) content in the offshore waters. Depletion of these nutrients during the bloom suggests that this species uses both types of nitrogen substrates. Cysts in the northernmost sampling stations in January and March indicate that upwelling water, rich in nitrates, also carried a seed stock population of P. minimum. SST patterns in the satellite imagery suggest wind-forcing as the responsible mechanisms triggering the algal bloom offshore of the Navachiste Lagoon Complex.  相似文献   

Constructed wetlands increase the taxonomic and functional diversity of a degraded floodplain   总被引：1，自引：0，他引：1  

Cecilia Español  Belinda Gallardo  Francisco A. Comín  M. Rosa Pino 《Aquatic Sciences - Research Across Boundaries》2015,77(1):27-44

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An Auxiliary Tool to Determine the Height of the Boundary Layer     

Cecilia Johansson  Hans Bergström 《Boundary-Layer Meteorology》2005,115(3):423-432

Results from radiosoundings, performed both over land and over sea, show that the ascent rate of a radiosounding balloon, the vertical velocity of the balloon, can be used to determine the height of the boundary layer. In many cases the balloon has a higher ascent rate in the boundary layer and a lower, less variable, ascent rate above. The decrease in ascending velocity appears as a jump at the top of the boundary layer. Two examples of potential temperature profiles for unstable stratification and one profile for stable conditions are shown with the corresponding ascent rates. A comparison between the boundary-layer height determined from potential temperature profiles and from ascent rates is presented for a larger dataset. The different ascent rates of the balloon in the boundary layer and above can be explained by a decrease in drag on the balloon in combination with a lowering of the critical Reynolds number in the boundary layer caused by turbulence. Hence, by simply logging the time from release of a radiosonde, it is possible to obtain additional information that can be used to estimate the height of both the unstable and stable boundary layers.  相似文献   

Sewage Sludge Activated Carbon as an Adsorbent and Catalytic Support: Evaluation of Nitrate Removal and Suzuki-Miyaura Cross-Coupling     

Clarissa H. Rosa  Cristiane R. Schmitt  Cecilia S. Fonseca  João Henrique Z. dos Santos  Toni J. Lopes  Gilber R. Rosa 《洁净——土壤、空气、水》2023,51(1):2100399

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Accounting for directionality as a function of structural typology in performance‐based earthquake engineering design          下载免费PDF全文

Cecilia I. Nievas  Timothy J. Sullivan 《地震工程与结构动力学》2017,46(5):791-809

For the seismic design of a structure, horizontal ground shaking is usually considered in two perpendicular directions, even though real horizontal ground motions are complex two‐dimensional phenomena that impose different demands at different orientations. While the issue of ground motion dependence on the orientation of the recording devices has been the focus of many significant developments during the last decade, the effects of directionality on the characteristics of the structure have received less attention. This work presents a proposal to calculate the probability of exceedance of elastic spectral displacements accounting for structural typology and illustrates its relevance by means of its application to two case‐study buildings. In order to ease its implementation in seismic design codes, a simplification is developed by means of a detailed statistical analysis of the results obtained using four sets of real hazard curves. The framework presented herein is considered to represent an important contribution to the field of performance‐based earthquake engineering, permitting improved treatment of directionality effects within seismic risk design and assessment. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献