Examinando por Materia "quantitative analysis"

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    Expanding level of coastal armouring: Case studies from different countries
    (COASTAL EDUCATION & RESEARCH FOUNDATION, 2011-01-01) Stancheva, M.; Rangel-Buitrago, N.; Anfuso, G.; Palazov, A.; Stanchev, H.; Correa, I.; Universidad EAFIT. Departamento de Ingeniería; Ciencias del Mar
    Concreting the natural shoreline by use of traditional hard protective structures, as well as by port/harbour developments is commonly known as coastal armouring. Over the recent decades the expanding level of coastline hardening and its adverse impacts on the environment has arisen as one of the most critical problems all over the world. Therefore, our goal in this study was to demonstrate the crucial issue of progressive extent of technogenous coastal occupation by two case studies from different countries in Europe and in South America: Bulgaria and Colombia. To assess direct impact of armouring on the coastline and adjacent areas two case areas were selected for detailed investigation: an 18 km long coastline of the large Varna Bay (Bulgarian Black Sea coast) and 349 km long littoral of the Cartagena municipality (Caribbean coastline of Colombia). An indicative coastal segmentation of the both case sites by geomorphologic and engineering criteria was first implemented in GIS environment. As well as, for quantitative assessment of the influence of all maritime structures (port and coast-protection) on the studied coasts the coefficient of technogenous impact K was explored. A GIS methodology was applied for data processing, mapping the natural landforms/structures and to evaluate the technogenous impact on the both coastlines. The identified high extent of impacts due to built hard defence structures along the selected study areas in Bulgaria and Colombia could be considered as indicative of the large technogenous occupation of the coasts and the increasing level of shoreline armouring as a global issue.
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    Quantitative biostratigraphic model for the tertiary of the lower Magdalena Basin, Colombian Caribbean
    (Ecopetrol, 2006-01-01) Cuartas, C.; Jaramillo, C.; Martínez, J.-I.; Universidad EAFIT. Departamento de Geología; Ciencias del Mar
    The reinterpretation of biostratigraphic information by new models and quantitative correlation techniques substantially improves its resolution and its correlative potential, thus minimizing oil exploration risks. With this aim, biostratigraphic information, i.e. first (FO) and last (LO) occurrence events of benthonic and planktonic foraminifera was analysed from sixteen wells from the Lower Magdalena Valley (LMV). The inconsistencies found in the biostratigraphic record, i.e. varying successions of first and last appearances of species from well to well as a result of several factors such incomplete sampling and preservation, true variation in the distribution of fosil taxa, etc., and the great amount of biostratigraphic data makes it practically impossible to accurately constrain basin history from biostratigraphic information by unaided visual inspection. This motivates the treatment of biostratigraphic information with new quantitative approaches, such as constrained optimization (CONOP9 software) and graphic correlation concepts (GraphCor 3,0) and the comparative method approach of Cooper et al. (2001). The succession of biostratigraphic events found through the application of each technique was statistically filtered and compared with Kendall tau coefficients whose values were 0,8. An optimal biostratigraphic succession of LOs was found and calibrated with the Berggren et al. (1995) global time scale by a LOESS regression model for the middle Eocene-Pliocene interval, thus revealing three major changes in sediment accumulation rates for the basin during this time interval: (1) middle Eocene to Oligocene, with low accumulation rates, (2) early Miocene to middle Miocene, with high accumulation rates and (3) late Miocene to Pliocene, with lower accumulation rates. The calibrated composite succession enabled the construction of age-well depth plots, which indicate periods of local deposition and accumulation rates, and periods of erosion, no deposition or very low accumulation rates (unconformities). The best plots were used to build a model for the correlation of unconformities, which shows that they are heterochronous, lasted at least 2,5 Ma, and are of limited extent. Finally, a correlation model was proposed that includes: (1) a time-calibrated succession of biostratigraphic events, and (2) a Haq curve that shows how each geologic period is recorded in each well.
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    Treatment of automotive industry oily wastewater by electrocoagulation: statistical optimization of the operational parameters.
    (IWA PUBLISHING, 2009-11-01) GilPavas, Edison; Molina-Tirado, Kevin; Angel Gomez-Garcia, Miguel; GilPavas, Edison; Molina-Tirado, Kevin; Angel Gomez-Garcia, Miguel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
    An electrocoagulation process was used for the treatment of oily wastewater generated from an automotive industry in Medellin (Colombia). An electrochemical cell consisting of four parallel electrodes (Fe and Al) in bipolar configuration was implemented. A multifactorial experimental design was used for evaluating the influence of several parameters including: type and arrangement of electrodes, pH, and current density. Oil and grease removal was defined as the response variable for the statistical analysis. Additionally, the BOD(5), COD, and TOC were monitored during the treatment process. According to the results, at the optimum parameter values (current density = 4.3 mA/cm(2), distance between electrodes = 1.5 cm, Fe as anode, and pH = 12) it was possible to reach a c.a. 95% oils removal, COD and mineralization of 87.4% and 70.6%, respectively. A final biodegradability (BOD(5)/COD) of 0.54 was reached.