Integration of geoelectric and geochemical data using Self-Organizing Maps (SOM) to characterize a landfill

Leachates from garbage dumps can significantly compromise their surrounding area. Even if the distance between these and the populated areas could be considerable, the risk of affecting the aquifers for public use is imminent in most cases. For this reason, the delimitation and monitoring of the leachate plume are of significant importance. Geoelectric data (resistivity and IP), and surface methane measurements, are integrated and classified using an unsupervised Neural Network to identify possible risk zones in areas surrounding a landfill. The Neural Network used is a Kohonen type, which generates; as a result, Self-Organizing Classification Maps or SOM (Self-Organizing Map). Two graphic outputs were obtained from the training performed in which groups of neurons that presented a similar behaviour were selected. Contour maps corresponding to the location of these groups and the individual variables were generated to compare the classification obtained and the different anomalies associated with each of these variables. Two of the groups resulting from the classification are related to typical values of liquids percolated in the landfill for the parameters evaluated individually. In this way, a precise delimitation of the affected areas in the studied landfill was obtained, integrating the input variables via SOMs. The location of the study area is not detailed for confidentiality reasons.Comment: 11 pages, 7 figure

INFERENCIA DE VELOCIDADES DE ONDAS S MEDIANTE LA TÉCNICA DE REDES NEURO-DIFUSAS

 In this work we use neuro fuzzy system (NFS) in order to obtain inference equations of shear velocity (Vs) of a well in terms of the logarithmic of its porosity (φ), its water saturation (Sw) and its clay volume (Vsh) data. The data belong to a well of the Guafita Field located in the Sub-basin of Apure, Venezuela. For training of NFS were used as input values: φ, Sw, Vsh; and Vs a s output. The training was made with multiple combinations of the independent parameters φ, Vsh and Sw. The results suggest that the use of the three types of registers simultaneously improves notoriously Vs inference, compared with the use of only one of them or combinations of two parameters. The number of fuzzy rules was changed for all combinations of parameters. It was observed that increasing the number of rules does not produce a marked improvement in the results.En este trabajo utilizamos la técnica de redes neuronales difusas (RND) con la finalidad de obtener ecuaciones que permitan predecir Velocidades de Cizalla (Vs) a partir de registros de porosidad (φ), saturación de agua (Sw) y volumen de arcilla (Vsh) pertenecientes a un pozo petrolero. Para el entrenamiento de las RND se utilizaron como datos de entrada valores de φ, Vsh y Sw y, como salida el registro de Vs. Los registros corresponden a un pozo perteneciente del Campo Guafita, ubicado en la subcuenca de Apure. El entrenamiento se realizó con múltiples combinaciones de los parámetros independientes φ, Vsh y Sw. Los resultados obtenidos sugieren que el uso de los tres tipos de registros simultáneamente mejora de forma notoria la inferencia de Vs, comparado con el uso de sólo uno de ellos o combinaciones de dos. El número de reglas difusas se varió para todas las combinaciones de parámetros. Se observó que un aumento del número de reglas no produce una mejoría notoria en los resultados

INFERENCE OF SHEAR WAVE VELOCITIES (VS) USING FUZZY NEURAL NETWORKS

En este trabajo utilizamos la técnica de redes neuronales difusas (RND) con la finalidad de obtener ecuaciones que permitan predecir Velocidades de Cizalla (Vs) a partir de registros de porosidad (φ), saturación de agua (Sw) y volumen de arcilla (Vsh) pertenecientes a un pozo petrolero. Para el entrenamiento de las RND se utilizaron como datos de entrada valores de φ, Vsh y Sw y, como salida el registro de Vs. Los registros corresponden a un pozo perteneciente del Campo Guafita, ubicado en la subcuenca de Apure. El entrenamiento se realizó con múltiples combinaciones de los parámetros independientes φ, Vsh y Sw. Los resultados obtenidos sugieren que el uso de los tres tipos de registros simultáneamente mejora de forma notoria la inferencia de Vs, comparado con el uso de sólo uno de ellos o combinaciones de dos. El número de reglas difusas se varió para todas las combinaciones de parámetros. Se observó que un aumento del número de reglas no produce una mejoría notoria en los resultados. In this work we use neuro fuzzy system (NFS) in order to obtain inference equations of shear velocity (Vs) of a well in terms of the logarithmic of its porosity (φ), its water saturation (Sw) and its clay volume (Vsh) data. The data belong to a well of the Guafita Field located in the Sub-basin of Apure, Venezuela. For training of NFS were used as input values: φ, Sw, Vsh; and Vs a s output. The training was made with multiple combinations of the independent parameters φ, Vsh and Sw. The results suggest that the use of the three types of registers simultaneously improves notoriously Vs inference, compared with the use of only one of them or combinations of two parameters. The number of fuzzy rules was changed for all combinations of parameters. It was observed that increasing the number of rules does not produce a marked improvement in the results

INFERENCE OF SHEAR WAVE VELOCITIES (VS) USING FUZZY NEURAL NETWORKS

En este trabajo utilizamos la técnica de redes neuronales difusas (RND) con la finalidad de obtener ecuaciones que permitan predecir Velocidades de Cizalla (Vs) a partir de registros de porosidad (φ), saturación de agua (Sw) y volumen de arcilla (Vsh) pertenecientes a un pozo petrolero. Para el entrenamiento de las RND se utilizaron como datos de entrada valores de φ, Vsh y Sw y, como salida el registro de Vs. Los registros corresponden a un pozo perteneciente del Campo Guafita, ubicado en la subcuenca de Apure. El entrenamiento se realizó con múltiples combinaciones de los parámetros independientes φ, Vsh y Sw. Los resultados obtenidos sugieren que el uso de los tres tipos de registros simultáneamente mejora de forma notoria la inferencia de Vs, comparado con el uso de sólo uno de ellos o combinaciones de dos. El número de reglas difusas se varió para todas las combinaciones de parámetros. Se observó que un aumento del número de reglas no produce una mejoría notoria en los resultados. In this work we use neuro fuzzy system (NFS) in order to obtain inference equations of shear velocity (Vs) of a well in terms of the logarithmic of its porosity (φ), its water saturation (Sw) and its clay volume (Vsh) data. The data belong to a well of the Guafita Field located in the Sub-basin of Apure, Venezuela. For training of NFS were used as input values: φ, Sw, Vsh; and Vs a s output. The training was made with multiple combinations of the independent parameters φ, Vsh and Sw. The results suggest that the use of the three types of registers simultaneously improves notoriously Vs inference, compared with the use of only one of them or combinations of two parameters. The number of fuzzy rules was changed for all combinations of parameters. It was observed that increasing the number of rules does not produce a marked improvement in the results

Paleomagnetic and rock magnetic study in the Saldaña Formation and Overlying Cretaceous Units in the northern Upper Magdalena Valley, Colombia

Rocas pertenecientes a las Formaciones Saldaña (Triásico Superior-Jurásico Inferior), Yaví y Alpujarra (Aptiano) en el sector Norte del Valle Superior del Magdalena en las localidades de Olaya Herrera y Alpujarra, se de smagnetizaron por los métodos térmico y de campo alterno con el fin de aislar componentes de magnetización y establecer su edad relativa a partir de pruebas de campo (horizontalización de capas, prueba de dique y discordancia). Análisis de mineralogía magnética permitieron reconocer qué minerales magnéticos registran dichos componentes. En estas unidades se logró aislar tanto el componente que registra la dirección del dipolo actual, así como componentes estables (característicos y primarios) de magnetización correspondientes a la edad de formación de cada unidad. El componente primario de la Fm. Saldaña se aisló confiablemente en el sector de Olaya Herrera (D=179.9 I=7.1 N=8 k=17.19 a95=13.7), en donde se documentan rotaciones de bloques anti-horario de 43º previo a la acumulación de la Fm. Yaví; se determinó que el mineral que registra este componente es principalmente magnetita. El componente estable de la Fm. Yaví se aisló en lavas y lodolitas del sector de Alpujarra y su dirección (D=5.2 I=6.2 N=7 k=40.15 a95=9.6) sugiere un tiempo de magnetización pre-deformación del Yaví. Hematita y magnetita son los minerales magnéticos que llevan este componente en la Fm. Yaví.Lavas, mudstones and volcaniclastics rocks from the Saldaña (Upper Triassic - Lower Jurassic), Yaví and Alpujarra (Aptian) formations in the northern Upper Magdalena Valley were demagnetized using thermal and alternating field methods in order to isolate magnetic components and to establish a relative age of magnetization using several field tests. Magnetic mineralogy analyses permit the identification of the minerals that record uncovered magnetic components. Isolated components represent different events of magnetization. Directions parallel to the present Earth magnetic field were isolated in all the studied units. Characteristic components isolated from the Yaví Formation in Alpujarra area and from the Saldaña Formation in Olaya Herrera area, may correspond to primary or near-to-deposition events of magnetization. In Olaya Herrera, the characteristic component of the Saldaña Formation (D=179.9 I=7.1 N=8 k=17.19 α95=13.7) is carried by magnetite. Characteristic components uncovered in two different structural domains document 43±29ºcounterclockwise rotations previous to deposition of the Aptian Yaví Formation. Characteristic directions of the Yaví Formation are carried by hematite and magnetite, and the mean-site direction (D=5.2 I=6.2 N=7 k=40.15 α95=9.6) suggests a pre-folding event of magnetization.Fil: Bayona, Germán. Corporación Geológica ARES; ColombiaFil: Silva, Carlos. Corporación Geológica ARES; Colombia. Universidad Nacional de Colombia; ColombiaFil: Rapalini, Augusto Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Costanzo-Alvarez, Vincenzo. Universidad Simón Bolívar; VenezuelaFil: Aldana, Milagrosa. Universidad Simón Bolívar; VenezuelaFil: Roncancio, Juan. Corporación Geológica ARES; Colombi

Hydrocarbon-induced magnetic contrasts in some Venezuelan and Colombian oil wells

In this work we present a review of our current research on the subject of near-surface hydrocarbon-induced magnetic contrasts. Samples are drill cuttings from number of Venezuelan and Colombian oil fields, and some soils from an oil prospective area. Results from rock magnetic, electronic paramagnetic resonance (EPR), extractable organic matter (EOM) and scanning electron microscopy (SEM) are discussed in light of new experiments. Two types of magnetic susceptibility (MS) anomalies have been recognized in oil well samples (i.e. A and B-like). A-like anomalies are probably associated to a reducing environment caused by the underlying reservoirs, whereas B-like anomalies might reflect lithological contrasts. Samples from A-like anomalous levels reveal the restrictive presence of authigenic spherical aggregates of submicronic Fe-rich magnetic crystals. Peaks of organic matter free radical concentration (OMFRC) and EOM are also observed at depth levels that lie close to those with A-like anomalies. Hysteresis ratios J rs /J s and H cr /H c could be used as additional criteria to recognize A-like magnetic contrasts. In soil samples, MS and OMFRC anomalies coincide with peaks of ethane concentration and an area underneath where source rock has reached appropriate conditions of pressure and temperature to generate hydrocarbons (Cretaceous kitchen). Different types of crude oils and subsurface structures could have also a direct effect on the observed amplitude of A-like anomalies

Paleomagnetismo y mineralogia magnetica en las unidades del Mesozoico de Bucaramanga y Macizo de Floresta

Análisis de paleomagnetismo y de mineralogía magnética en rocas del Jurásico y Cretácico Inferior del área de Bucaramanga (Fms. Bocas, Jordán, Girón y Los Santos), y del sur del Macizo de Floresta (Fms. Girón y Tibasosa) permitieron determinar componentes característicos y secundarios de magnetización, y establecer el mineral asociado a dicho componente magnético. Componentes secundarios con una dirección paralela a la dirección del campo magnético actual fueron aislados en todas las unidades y en rango de temperaturas bajas a intermedias ( 4 km) entre estas dos áreas soporta la posibilidad de rotación y/o basculamiento de bloques tectónicos previos a los eventos de magnetización de la Fm. Girón. Los componentes magnéticos característicos (primarios) aislados en ambos sectores muestran una clara diferencia entre las paleolatitudes del Jurásico Temprano- Cretácico Temprano con las determinadas para unidades de edad similar en el cratón, sugiriendo así posibles movimientos translacionales de bloques con respecto a la margen occidental del Cratón Suramericano.Paleomagnetic and magnetic mineralogy analyses from Jurassic – Lower Cretaceous rocks (Bocas, Jordán, Girón, Los Santos Fms) in the Bucaramanga area and in the southern segment of the Floresta Massif (Girón and Tibasosa Fms.) allow to determine characteristic (primary) and secondary magnetic components and to identify the carrying minerals. Secondary components have directions parallel to the current magnetic field direction; they were isolated in all the units and in unblocking temperature below 620ºC or by Alternating Field. Characterisitc (primary) components were isolated at unblocking temperatures ranging between 550º and 700ºC, with exception of limestones of the Tibasosa Formation that had unblocking temperatures between 300º and 500ºC. The relative time of magnetization was constrained from fold, conglomerate, unconformity, and baked contact tests. The characteristic component isolated in the Middle(?) Jurassic Jordan Fm. constrains 96±16º counterclockwise rotation of fault-bounded blocks at La Mesa de Los Santos area with respect to the Rionegro area. In addition, abrupt thickness change in the Girón Fm. from 100m to >4 km between those areas support the possibility of rotation and/or tilting of tectonic blocks, previous to the time of magnetization of the Girón Fm. The characteristic (primary) magnetic components isolated in both areas show a noticeable difference among the Early Jurassic-Early Cretaceous paleolatitudes and paleolatitudes calculated by other authors in rocks of the same age in the stable craton, suggesting possible translations of these blocks with respect to the western plate margin of South America.Fil: Ayala Calvo, Rosa Carolina. Corporación Geológica ARES; ColombiaFil: Veloza Fajardo, Gabriel Eduardo. Corporación Geológica ARES; ColombiaFil: Bayona, Germán. Corporación Geológica ARES; ColombiaFil: Gomez Casallas, Mayeli. Ministerio de Minas y Energía. Servicio Geológico Colombiano; ColombiaFil: Rapalini, Augusto Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Costanzo-Alvarez, Vincenzo. Universidad Simón Bolivar; VenezuelaFil: Aldana, Milagrosa. Universidad Simón Bolivar; VenezuelaFil: Cortés, Martín. Corporación Geológica ARES; Colombi

National rare diseases registry in Spain: pilot study of the Spanish Rare Diseases Registries Research Network (SpainRDR)

Supplement 7th European Conference on Rare Diseases and Orphan Products (ERCD 2014)Background The development of a national Rare Diseases (RD) registry in Spain was launched in 2012 with the project SpainRDR, supported by the International Rare Diseases Research Consortium (IRDiRC). SpainRDR includes two different strategies: patient registries addressed to patient outcome research and population-based registries addressed to epidemiologic research, health and social planning [1]. The pilot study aims to detect the difficulties of developing the national and population-based RD registry

THREE STRATEGIES TO SOLVE THE WAVE PROPAGATION PROBLEM IN A 3D FLUID-SOLID INTERFACE / Tres estrategias para resolver el problema de propagación de ondas en una interfase 3D fluido-sólido

Two implicit strategies and an explicit approach have been used to solve the problem of a fluid-solid interface in a 3D medium. One of the implicit strategies considers a transitional zone and the other is the traditional one. To solve the boundary conditions at the interface using the explicit strategy, two planes of “fictitious points” were added to the grid. A predictor-corrector approach was considered in this case. A Finite Difference Staggered-Grid method was used to solve the wave propagation problem in all the cases. The results obtained show a marked difference between the three strategies. For the study configuration and the hardware and software conditions of this work, the traditional implicit strategy seems to better model the fluid-solid interface. In this case, the internal interface is not treated by explicit boundary conditions, as it is represented naturally by changes of the elastic parameters and the densities. On the other hand, the reflected wave field shows higher amplitudes than those expected for this problem in the images obtained with both, the explicit strategy and the one that incorporates the transitional zone. Such undesirable effects could be the result of the combination, in the first case, of the small size of the propagation volume considered in this work, the low performance of the boundary condition function applied at the external surfaces of the volume and the predictor-corrector method for the explicit strategy. The first two aspects combined with the presence of the transitional zone could be responsible of the behavior observed for the second implicit strategyRESUMENDos estrategias de naturaleza implícita y una de tipo explícito son utilizadas para resolver el problema que considera una interfase fluido-sólido en un medio 3D. Una estrategia implícita considera una zona transicional y la otra es la tradicional. Las condiciones de borde en la interfase en la estrategia explícita se resuelven agregando dos planos de “puntos ficticios” a la malla y se aplica una estrategia predictor-corrector. Se usó un método staggered-grid en Diferencias Finitas en todos los casos. Los resultados indican una diferencia marcada entre las tres estrategias. Para el ejemplo estudiado y las condiciones de hardware-software usadas, la estrategia implícita tradicional parece ser la que mejor modela la interfase fluido-sólido. La interfase interna no es tratada de forma explícita ya que los cambios de los parámetros elásticos y las densidades son naturalmente representados. El campo de ondas en las imágenes obtenidas con la estrategia explícita y la que incorpora la zona de transición, muestra intensidades mayores a las esperadas en este tipo de problema. Los efectos indeseables pudieran ser consecuencia de la combinación, en el primer caso, del pequeño tamaño del volumen de propagación considerado en este trabajo, del débil efecto de la función de absorción aplicada en las superficies externas del volumen y del método predictor-corrector para la estrategia explícita. Los dos primeros aspectos, combinados con la presencia de la zona transicional, podrían ser la causa del comportamiento observado con la segunda estrategia implícita.Palabras clave: Interfase, Fluido-sólido, Propagación de onda, Diferencias finitas, Staggered-grid