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201.
F. Javier Torrijo Julio Garzón-Roca Santiago Alija Mário Quinta-Ferreira 《Environmental Earth Sciences》2017,76(19):658
This paper presents an assessment on the use of dynamic compaction as a ground improvement technique in a port’s hydraulic fill in the new southern dock of Sagunto’s Harbor near Valencia (Spain). Soil behavior improvement was monitored by several in situ techniques such as boreholes with SPTs, DPSH, CPTU and CSWS geophysical tests. A total energy between 2188 and 3125 kN/m2 (depending the area) was applied to the hydraulic fill by the dynamic compaction procedure. In situ techniques led to evaluate dynamic compaction efficiency, as well as controlling ground modifications that might cause potential damages to adjacent buildings. The dynamic compaction carried out was capable of fulfilling requirements established to use the area, that is, an average deformability modulus (E′) of 30 MPa with a minimum of 20 MPa, in a depth of 10 m. Moreover, dynamic compaction increased hydraulic fill relative density by about 75%. 相似文献
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Assessment of evaporation and water fluxes in a column of dry saline soil subject to different water table levels 总被引:1,自引:0,他引:1 下载免费PDF全文
María Fernanda Hernández‐López Jorge Gironás Isabelle Braud Francisco Suárez José Francisco Muñoz 《水文研究》2014,28(10):3655-3669
Dry saline soils are common in the arid and hyper‐arid basins located in the Chilean Altiplano, where evaporation from shallow groundwater is typically the major component of the water balance. Thus, a good understanding of evaporation processes is necessary for improving water resource planning and management in these regions. In this study, we conducted laboratory experiments with a natural saline soil column to estimate evaporation rates and assess the liquid and water vapor fluxes under different water table levels. Water content, electrical conductivity and temperature at different depths were utilized to assess the liquid and water vapor fluxes in the soil column. We observed movement of water that dissolves salts from the soil and transports them to areas in the column where they accumulate. Isothermal liquid flux was predominant, while thermal and isothermal liquid and thermal water vapor fluxes were negligible, except for deep water table levels where isothermal and thermal water vapor fluxes had similar magnitude but opposite directions. Differences observed in total fluxes for all water table levels were due to different upward and downward fluxes, which depend on changes in water content and temperature within the soil profile. Both the vapor flux magnitude and direction were found to be very sensitive to the choice of empirical parameters used in flux quantification, such as tortuosity and the enhancement factor for local temperature gradients in the air phase within the column. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
206.
José M. Angulo Francisco J. Esquivel 《Stochastic Environmental Research and Risk Assessment (SERRA)》2014,28(5):1187-1206
Different approaches and tools have been adopted for the analysis and characterization of regional seismicity based on spatio–temporal series of event occurrences. Two main aspects of interest in this context concern scaling properties and dimensional interaction. This paper is focused on the statistical use of information-theoretic concepts and measures in the analysis of structural complexity of seismic distributional patterns. First, contextual significance is motivated, and preliminary elements related to informational entropy, complexity and multifractal analysis are introduced. Next, several technical and methodological extensions are proposed. Specifically, limiting behaviour of some complexity measures in connection with generalized dimensions is established, justifying a concept of multifractal complexity. Under scaling behaviour, a mutual-information-related dependence coefficient for assessing spatio–temporal interaction is defined in terms of generalized dimensions. Also, an alternative form of generalized dimensions based on Tsallis entropy convergence rates is formulated. Further, possible incorporation of effects, such as earthquake magnitude, is achieved in terms of weighted box-counting distributions. Different aspects in relation to the above elements are analyzed and illustrated using two well-known series of seismic event data of an underlying different nature, occurred in the areas of Agrón (Granada, Spain) and El Hierro (Canary Islands, Spain). Finally, various related directions for continuing research are indicated. 相似文献
207.
André Francisco Pilon 《Environmental Geology》2009,57(2):337-345
For the diagnosis and prognosis of the problems of quality of life, a multidisciplinary ecosystemic approach encompasses four
dimensions of being-in-the-world, as donors and recipients: intimate, interactive, social and biophysical. Social, cultural
and environmental vulnerabilities are understood and dealt with, in different circumstances of space and time, as the conjugated
effect of all dimensions of being-in-the-world, as they induce the events (deficits and assets), cope with consequences (desired
or undesired) and contribute for change. Instead of fragmented and reduced representations of reality, diagnosis and prognosis
of cultural, educational, environmental and health problems considers the connections (assets) and ruptures (deficits) between
the different dimensions, providing a planning model to develop and evaluate research, teaching programmes, public policies
and field projects. The methodology is participatory, experiential and reflexive; heuristic-hermeneutic processes unveil cultural
and epistemic paradigms that orient subject-object relationships; giving people the opportunity to reflect on their own realities,
engage in new experiences and find new ways to live better in a better world. The proposal is a creative model for thought
and practice, providing many opportunities for discussion, debate and development of holistic projects integrating different
scientific domains (social sciences, psychology, education, philosophy, etc.).
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
相似文献
André Francisco PilonEmail: |
208.
Javier Alcántara-Carrió Silvia Albarracín Isabel Montoya Montes Germán Flor-Blanco Ángela Fontán Bouzas Jorge Rey Salgado 《Geo-Marine Letters》2013,33(2-3):209-216
The objective of this study is to document and interpret a recently discovered carbonate-cemented coastal barrier on the inner shelf of the Gulf of Valencia (western Mediterranean Sea). The coastal barrier was identified in a high-resolution digital bathymetric model based on a cartographic survey of the study area using a multibeam echosounder. Moreover, radiocarbon dating and petrographic analyses were performed on a rock sample recovered from the seabed. The data reveal the submerged coastal barrier to be approx. 1.7 km wide and 70 km long, and incised by channels of various dimensions. Aligned more or less parallel to the modern coastline, it is interpreted as corresponding to the shoreline of a former sea-level stillstand. The barrier and lagoon system became stranded above sea level in the course of a subsequent forced regression, which also caused the incision of the river courses. Age dating of the cemented rock suggests that the fossil coastal barrier most probably formed during the prolonged Tyrrhenian (Eemian) sea-level highstand, induration taking place by carbonate cementation at the contact between freshwater and seawater (beach-rock formation). The fact that the fossil barrier is today submerged below modern sea level is explained by the sustained subsidence affecting the region. 相似文献
209.
Carreras-Aubets M Montero FE Kostadinova A Carrassón M 《Marine pollution bulletin》2012,64(9):1853-1860
We examined parasite populations and communities in the Mediterranean sentinel fish species, Mullus barbatus, sampled at a small-scale PCB gradient at the shelf sediments off Catalonian coasts of the Western Mediterranean. A recurrent feature at both the population and community level was the differentiation of the samples along the increasing PCB levels simultaneously registered in the sediments. Both directly transmitted ectoparasites and endoparasites with complex life-cycles transmitted via food chains exhibited a decrease in abundance with the increase in PCB levels. Parasite numerical responses translated into significant differences in infracommunity structure with decreasing predictability associated with increasing PCB levels. The abundance of two species, the specialist Opecoeloides furcatus and the generalist nematode Hysterothylacium fabri, contributed substantially to the observed dissimilarity between infracommunity samples along the gradient. The observed parasite responses to moderate levels of pollution were simultaneously validated by both chemical monitoring and effect biomarkers. 相似文献
210.
Space- and ground-based measurements of sulphur dioxide emissions from Turrialba Volcano (Costa Rica) 总被引:2,自引:0,他引:2
Robin Campion Maria Martinez-Cruz Thomas Lecocq Corentin Caudron Javier Pacheco Gaia Pinardi Christian Hermans Simon Carn Alain Bernard 《Bulletin of Volcanology》2012,74(7):1757-1770
Remotely sensed measurements of sulphur dioxide (SO2) emitted by Turrialba Volcano (Costa Rica) are reported for the period September 2009–January 2011. These measurements were obtained using images from Advanced Spaceborne Thermal Emission and Reflexion radiometer, Ozone Monitoring Instrument and a ground-based UV camera. These three very different instruments provide flux measurements in good agreement with each other, which demonstrate that they can be integrated for monitoring SO2 fluxes. Fluxes from Turrialba increased fourfold in January 2010, following a phreatic explosion that formed a degassing vent in the W crater of Turrialba. Since then, the SO2 flux has remained high (30–50?kg/s) but seems to be showing a slowly decreasing trend. We interpret this evolution as the start of open vent degassing from a recently intruded magma body. The opening of the degassing vent decreased the confining pressure of the magma body and allowed the gases to bypass the hydrothermal system. 相似文献