Using probabilistic analysis to improve greenhouse gas baseline forecasts in developing country contexts: the case of Chile     

Raul O’ Ryan  Carlos Benavides  Juan Pablo San Martín  Javier Mallea 《Climate Policy》2019,19(3):299-314

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Bacterially mediated mineralization of vaterite   总被引：1，自引：0，他引：1  

Carlos Rodriguez-Navarro  Concepcion Jimenez-Lopez  Maria Teresa Gonzalez-Muñoz 《Geochimica et cosmochimica acta》2007,71(5):1197-1213

Myxococcus xanthus, a common soil bacterium, plays an active role in the formation of spheroidal vaterite. Bacterial production of CO₂ and NH₃ and the transformation of the NH₃ to and OH⁻, thus increasing solution pH and carbonate alkalinity, set the physicochemical conditions (high supersaturation) leading to vaterite precipitation in the microenvironment around cells, and directly onto the surface of bacterial cells. In the latter case, fossilization of bacteria occurs. Vaterite crystals formed by aggregation of oriented nanocrystals with c-axis normal to the bacterial cell-wall, or to the core of the spherulite when bacteria were not encapsulated. While preferred orientation of vaterite c-axis appears to be determined by electrostatic affinity (ionotropic effect) between vaterite crystal (0001) planes and the negatively charged functional groups of organic molecules on the bacterium cell-wall or on extracellular polymeric substances (EPS), analysis of the changes in the culture medium chemistry as well as high resolution transmission electron microscopy (HRTEM) observations point to polymorph selection by physicochemical (kinetic) factors (high supersaturation) and stabilization by organics, both connected with bacterial activity. The latter is in agreement with inorganic precipitation of vaterite induced by NH₃ and CO₂ addition in the protein-rich sterile culture medium. Our results as well as recent studies on vaterite precipitation in the presence of different types of bacteria suggest that bacterially mediated vaterite precipitation is not strain-specific, and could be more common than previously thought.  相似文献   

Electrooxidation Combined with Ozonation in Hospital Laundry Effluents Treatment          下载免费PDF全文

Carlos Alexandre Lutterbeck  Rômulo de Oliveira Schwaickhardt  Alexandre Straatmann  Lourdes Teresinha Kist  Eduardo A. Lobo  Ênio Leandro Machado 《洁净——土壤、空气、水》2014,42(5):601-608

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Guest editorial: old masonry under seismic loading     

Carlos Sousa Oliveira  Anibal Costa 《Bulletin of Earthquake Engineering》2012,10(1):1-5

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Ozone Weekend Effect Analysis in Three European Urban Areas     

José Carlos M. Pires 《洁净——土壤、空气、水》2012,40(8):790-797

This paper aims to apply statistical procedures to analyse the ozone weekend effect (OWE) in three European urban areas: Lisbon, Oporto and London. Seasonal variations of surface ozone (O₃) and total oxidant species (O_x) concentrations are presented. The studied period was from January 2007 to December 2009. The O₃ annual average profile in London was significantly different from the ones achieved for Lisbon and Oporto, due to the high emissions of nitrogen oxides and low temperatures (associated with low solar radiations). The influence of nitrogen oxides in atmospheric chemistry of London was analysed by linear correlations between O₃ concentrations and NO₂/NO ratio. High values during almost all period showed that O₃ concentrations are mainly influenced by NO? NO₂? O₃ chemical reaction. On the other hand, the linear correlations between O₃ and NO₂ concentrations only presented positive values in Lisbon and Oporto. This behaviour is associated with photo‐dissociation of NO₂, producing O₃ during the spring and summer periods. Additionally, cluster analysis was applied to group the days of week according the correspondent O₃ behaviour. The weekend and some weekdays (immediately after or before) were grouped in the same cluster, showing that OWE occurs in all urban areas selected in this study. These findings suggest that the applied statistical procedures should be used to analyse the OWE and that the causes for the different O₃ behaviours during the week may be influenced by meteorological variables.  相似文献   

Zone of main contribution to the measured signal for a circular current loop source and receiver on the surface of a conductive half‐space     

Marcos Vitor Barbosa Machado  Carlos Alberto Dias 《Geophysical Prospecting》2012,60(6):1167-1185

The electric and magnetic fields generated by an individual horizontal current ring induced inside a homogeneous conductive half‐space, originating from an external large circular loop source of current in the presence of a flat half‐space, are deduced. A check of self‐consistency for these expressions led to the known general functions for these fields due to the same external source in the presence of that medium. The current rings’ mutual coupling related to the magnetic field's radial component is thoroughly analysed and its specific members are presented. The existence of a relatively small zone inside the half‐space responsible for the main contribution for the signal measured at the observation point, with the source and receiver on the ground surface, is made evident. For increasing values of frequency, at a given transmitter‐receiver (T–R) configuration, this zone shrinks and its central point moves away from a maximum depth of about 30% and horizontal distance of nearly 85%, of the T–R separation, to a point very close to the receiver position. The coordinates of the central point of this zone of main contribution are provided as approximated functions in terms of the induction number .  相似文献   

Uncertainty analysis along the ecological quality status of water bodies: the response of the Posidonia oceanica multivariate index (POMI) in three Mediterranean regions     

Mascaró O  Bennett S  Marbà N  Nikolić V  Romero J  Duarte CM  Alcoverro T 《Marine pollution bulletin》2012,64(5):926-931

Uncertainty analyses allow the identification and quantification of the factors that contribute to the potential misclassification of the ecological status of water bodies, helping to improve the sampling design used in monitoring. Here we used a Posidonia oceanica multivariate index (POMI) bio-monitoring dataset covering a total of 81 sites distributed throughout 28 water bodies from the coast of Catalonia, Balearic Islands and Croatia to determine the levels of uncertainty associated with each region and how they change according to the quality status of water bodies. Overall, variability among sites (meadows) within water bodies was the factor that generated the greatest risk of misclassification among the three regions, within which the Balearic Islands had the lowest uncertainty, followed by Croatia and Catalonia. When water bodies classified in good/high quality were separated from those in moderate/poor status classes, we found that the latter displayed higher levels of uncertainty than the former.  相似文献   

Evaluation of the Optimal Utility of Some Investment Projects with Irreversible Environmental Effects     

Iñigo Arregui  Carlos Vázquez 《Pure and Applied Geophysics》2015,172(1):149-165

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Spatial and environmental analysis of an ostracod metacommunity from endorheic lakes     

Andreu Castillo-Escrivà  Luis Valls  Carlos Rochera  Antonio Camacho  Francesc Mesquita-Joanes 《Aquatic Sciences - Research Across Boundaries》2016,78(4):707-716

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Salt body detection from seismic data via sparse representation          下载免费PDF全文

Carlos Ramirez  German Larrazabal  Gladys Gonzalez 《Geophysical Prospecting》2016,64(2):335-347

In seismic interpretation and seismic data analysis, it is of critical importance to effectively identify certain geologic formations from very large seismic data sets. In particular, the problem of salt characterization from seismic data can lead to important savings in time during the interpretation process if solved efficiently and in an automatic manner. In this work, we present a novel numerical approach that is able to automatically segmenting or identifying salt structures from a post‐stack seismic data set with a minimum intervention from the interpreter. The proposed methodology is based on the recent theory of sparse representation and consists in three major steps: first, a supervised learning assisted by the user which is performed only once, second a segmentation process via unconstrained ?₁ optimization, and finally a post‐processing step based on signal separation. Furthermore, since the second step only depends upon local information at each time, the whole process greatly benefits from parallel computing platforms. We conduct numerical experiments in a synthetic 3D seismic data set demonstrating the viability of our method. More specifically, we found that the proposed approach matches up to 98.53% with respect to the corresponding 3D velocity model available in advance. Finally, in appendixes A and B, we present a convergence analysis providing theoretical guarantees for the proposed method.  相似文献