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41.
Soares Wilson Cartaxo Coutinho Roberto Quental da Cunha Renato Pinto 《Geotechnical and Geological Engineering》2021,39(8):5599-5618
Geotechnical and Geological Engineering - Hollow auger piles are a new solution technique being used more often in recent years as a foundation for buildings of 15 floors or less in the coastal... 相似文献
42.
Quintaneiro C Monteiro M Pastorinho R Soares AM Nogueira AJ Morgado F Guilhermino L 《Marine pollution bulletin》2006,52(11):1406-1413
The degradation of estuaries is a result of human activities which overloads the environment with substances of both industrial and/or natural origins. Bioindicators have been consistently used to interpret effects of contaminants in the environment. In this study, the use of biomarkers (particular measurable characteristics of a bioindicator organism) was used to evaluate the contamination by xenobiotics of Crangon crangon natural populations. The central aim was to evaluate the capability of a battery of biomarkers to discriminate sites with different types of contamination. The activity of the enzymes cholinesterases (ChE), lactate dehydrogenase (LDH) and glutathione S-transferases (GST) were used as biomarkers. In addition, the ChE form(s) present in the cephalotorax of C. crangon were characterised. Organisms were seasonally sampled from winter 2001/2002 to autumn of 2002, at "reference" sites and at sites that receive agricultural, industrial and/or urban effluents. Results obtained in the characterisation of ChE with different substrates and selective inhibitors demonstrate that the form of ChE present in the cephalotorax of C. crangon shows proprieties of vertebrates' AChE and therefore it may be classified as true AChE-like ChE. The battery of biomarkers exhibited seasonal and local variations, apparently related to agricultural, industrial or urban effluent contamination. The tested biomarkers proved to be able to discriminate sources of environmental contamination, and confirms C. crangon as a sensitive species suitable to be used as a bioindicator. 相似文献
43.
The practice of stochastic simulation for different environmental and earth sciences applications creates new theoretical
problems that motivate the improvement of existing algorithms. In this context, we present the implementation of a new version
of the direct sequential co-simulation (Co-DSS) algorithm. This new approach, titled Co-DSS with joint probability distributions,
intends to solve the problem of mismatch between co-simulation results and experimental data, i.e. when the final biplot of
simulated values does not respect the experimental relation known for the original data values. This situation occurs mostly
in the beginning of the simulation process. To solve this issue, the new co-simulation algorithm, applied to a pair of covariates
Z
1(x) and Z
2(x), proposes to resample Z
2(x) from the joint distribution F(z
1,z
2) or, more precisely, from the conditional distribution of Z
2(x
0), at a location x
0, given the previously simulated value
z1(l)(x0)z_{1}^{(l)}(x_{0})
(F(Z2|Z1=z1(l)(x0)F(Z_{2}|Z_{1}=z_{1}^{(l)}(x_{0})
). The work developed demonstrates that Co-DSS with joint probability distributions reproduces the experimental bivariate
cdf and, consequently, the conditional distributions, even when the correlation coefficient between the covariates is low. 相似文献
44.
B. J. Vieira M. C. Freitas A. F. Rodrigues A. M. G. Pacheco P. M. Soares N. Correia 《Journal of Atmospheric Chemistry》2004,49(1-3):231-249
In this study, more than 20 minor and trace elements have been determined by INAA (instrumental neutron activation analysis), in different species of lichens in three Portuguese islands of the Central North Atlantic (Santa Maria, Terceira, and Madeira Islands). The foliose species Parmotrema bangii, Parmotrema robustum, Parmotrema crinitum, Flavoparmelia caperata, Platismatia glauca, and the fruiticose species Ramalina canariensis, Ramalina farinacea, Ramalina implectens, Ramalina pusilla, Cladonia furcata, Cladonia coniocraea, Usnea dasaea, Usnea esperantiana, were the collected species. Samples of superficial soils were also collected and the fraction below 64 m was analysed. The enrichment factors relative to this fraction using Al as the normalising element were calculated. Fruiticose and foliose lichens displayed different EF values concerning bromine and potassium. The first was more enriched in the foliose species while the latter was more enriched in the fruiticose species and was assigned to the physiological response. Enrichment was found for Mg, Cs, As, Hg, Na, Zn, and Cl, in all the species. Lichen-based concentration patterns were shown for Na, Al, Cl, Br, Sb, Ce, and Hg and compared to similar patterns in Portugal mainland. In general, the patterns compared well except for Cl, Na, and Br. Background levels of the epiphytic lichens collected in the islands were obtained. 相似文献
45.
A procedural paleosurface mapping tool, using hypsometric curves and digital elevation models, was developed and applied to
three hydrographic basins that erode common areas in the coastal ranges of Brazil, in southeastern South America. The method
consists of identifying areas favorable for the occurrence of paleosurfaces and their corresponding surficial formations as
correlated to specific erosion events. Attributes from hypsometric curves, and logarithmic functions fitted to proper curve
segments, are combined with common morphometric properties of paleosurfaces given a set of criteria. Zones satisfying the
criteria are mapped as pertaining to specific paleosurfaces. Field survey confirms the agreement between predicted and observed
occurrence and absence of paleosurfaces. 相似文献
46.
Sidnei Pires Rostirolla Paulo César Soares Hung Kiang Chang 《Natural Resources Research》1998,7(1):7-24
A methology to define favorable areas in petroleum and mineral exploration is applied, which consists in weighting the exploratory variables, in order to characterize their importance as exploration guides. The exploration data are spatially integrated in the selected area to establish the association between variables and deposits, and the relationships among distribution, topology, and indicator pattern of all variables. Two methods of statistical analysis were compared. The first one is the Weights of Evidence Modeling, a conditional probability approach (Agterberg, 1989a), and the second one is the Principal Components Analysis (Pan, 1993). In the conditional method, the favorability estimation is based on the probability of deposit and variable joint occurrence, with the weights being defined as natural logarithms of likelihood ratios. In the multivariate analysis, the cells which contain deposits are selected as control cells and the weights are determined by eigendecomposition, being represented by the coefficients of the eigenvector related to the system’s largest eigenvalue. The two techniques of weighting and complementary procedures were tested on two case studies: 1. Recôncavo Basin, Northeast Brazil (for Petroleum) and 2. Itaiacoca Formation of Ribeira Belt, Southeast Brazil (for Pb-Zn Mississippi Valley Type deposits). The applied methdology proved to be easy to use and of great assistance to predict the favorability in large areas, particularly in the initial phase of exploration programs. 相似文献
47.
The existence of a transition in the slope of the wind-generated gravity wave spectrum from a f−4 to a f−5 power law, at a given frequency in the high frequency range, is examined. Evidence of its existence and of the non-uniqueness of the wave spectrum slope in the equilibrium range is presented. Furthermore, it is demonstrated that the statistical variability of the spectral estimates makes it difficult to obtain reliable results from limited sets of finite length wave records. 相似文献
48.
Leonardo Azevedo Rúben Nunes Amílcar Soares Guenther Schwedersky Neto Teresa S. Martins 《Geophysical Prospecting》2018,66(Z1):116-131
Seismic inversion plays an important role in reservoir modelling and characterisation due to its potential for assessing the spatial distribution of the sub‐surface petro‐elastic properties. Seismic amplitude‐versus‐angle inversion methodologies allow to retrieve P‐wave and S‐wave velocities and density individually allowing a better characterisation of existing litho‐fluid facies. We present an iterative geostatistical seismic amplitude‐versus‐angle inversion algorithm that inverts pre‐stack seismic data, sorted by angle gather, directly for: density; P‐wave; and S‐wave velocity models. The proposed iterative geostatistical inverse procedure is based on the use of stochastic sequential simulation and co‐simulation algorithms as the perturbation technique of the model parametre space; and the use of a genetic algorithm as a global optimiser to make the simulated elastic models converge from iteration to iteration. All the elastic models simulated during the iterative procedure honour the marginal prior distributions of P‐wave velocity, S‐wave velocity and density estimated from the available well‐log data, and the corresponding joint distributions between density versus P‐wave velocity and P‐wave versus S‐wave velocity. We successfully tested and implemented the proposed inversion procedure on a pre‐stack synthetic dataset, built from a real reservoir, and on a real pre‐stack seismic dataset acquired over a deep‐water gas reservoir. In both cases the results show a good convergence between real and synthetic seismic and reliable high‐resolution elastic sub‐surface Earth models. 相似文献
49.
Soares Gabriel Yamazaki Yosuke Matzka Jürgen Pinheiro Katia Stolle Claudia Alken Patrick Yoshikawa Akimasa Uozumi Teiji Fujimoto Akiko Kulkarni Atul 《Studia Geophysica et Geodaetica》2019,63(2):304-319
Studia Geophysica et Geodaetica - Ground and space-based geomagnetic data were used in the investigation of the longitudinal, seasonal and lunar phase dependence of the equatorial counter... 相似文献
50.