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Search Results: 1 - 10 of 13857 matches for " Rafael Angulo-Jaramillo "
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Combined Effect of Infiltration, Capillary Barrier and Sloping Layered Soil on Flow and Solute Transfer in a Heterogeneous Lysimeter  [PDF]
Le Binh Bien, Dieuseul Predelus, Laurent Lassabatere, Thierry Winiarski, Rafael Angulo-Jaramillo
Open Journal of Modern Hydrology (OJMH) , 2013, DOI: 10.4236/ojmh.2013.33018
Abstract: This aim of this paper is to describe a study of the combined effect of infiltration, capillary barrier and sloping layered soil on both flow and solute transport processes in a large, physical model (1 × 1 × 1.6 m3) called LUGH (Lysimeter for Urban Groundwater Hydrology) and a 3D numerical flow model. Sand and a soil composed of a bimodal sand-gravel mixture were placed in the lysimeter to simulate one of the basic structural and textural elements of the heterogeneity observed in the vadose zone under an infiltration basin of Lyon (France). Water and an inert tracer (KBr) were injected from the top of the lysimeter using a specific water sprinkler system and collected at 15 different outlets at the bottom. The outlet flows and the 15 breakthrough curves obtained presented high heterogeneity, emphasising the establishment of preferential flows resulting from both capillary barrier and soil layer dip effects. Numerical modelling led to better understanding of the mechanisms responsible for these heterogeneous transfers and it was also used to perform a sensitivity analysis of the effects of water velocity (water and solute flux fed by the sprinkler) and the slope interface. The results show that decreasing velocity and increasing the slope of the interface can lead to the development of preferential flows. In addition, the offset of the centre of gravity of the flow distribution at the output increases linearly as a function of the slope angle of the layered soil. This paper provides relevant information on the coupling between hydrodynamic processes and pollutant transfer in unsaturated heterogeneous soil and emphasizes the role of the geometry of the interfaces between materials and boundary conditions as key factors for preferential flow.

Tracing Water Flow and Colloidal Particles Transfer in an Unsaturated Soil  [PDF]
Dieuseul Prédélus, Laurent Lassabatere, Artur Paiva Coutinho, Cédric Louis, Thomas Brichart, Erij Ben Slimène, Thierry Winiarski, Rafael Angulo-Jaramillo
Journal of Water Resource and Protection (JWARP) , 2014, DOI: 10.4236/jwarp.2014.67067

In recent years, many studies have been carried out on colloidal particle transfer in the unsaturated zone because they can be a risk to the environment either directly or as a vector of pollutants. A study was conducted on the influence of porous media structure in unsaturated conditions on colloidal particle transport. Three granular materials were set up in columns to replicate a fluvio-glacial soil from the unsaturated zone in the Lyon area (France). It is a sand, a bimodal mixture in equal proportion by weight of sand and gravel, and a fraction of bimodal mixture. Nanoparticles of silica (SiO2-Au-FluoNPs), having a hydrodynamic diameter between 50 and 60 nm, labeled by organic fluorescent molecules were used to simulate the transport of colloidal particles. A nonreactive tracer, bromide ion (Br-) at a concentration of C0,s = 10-2 M was used to determine the hydrodispersive properties of porous media. The tests were carried out first, with a solution of nanoparticles (C0,p = 0.2 g/L) and secondly, with a solution of nanoparticles and bromine. The transfer model based on fractionation of water into two phases, mobile and immobile, MIM, correctly fits the elution curves. The retention of colloidal particles is greater in the two media of bimodal particle size than that in the sand, which clearly demonstrates the role of textural heterogeneity in the retention mechanism. The increase in ionic strength produced by alimenting the columns with colloidal particle suspension in the presence of bromide, increases retention up to 25% in the sand. The total concentration profile of nanoparticles collected at the end of the experiment shows that the colloidal particles are retained primarily at the entrance of the columns. Hydrodispersive calculated parameters indicate

Vadose Zone Heterogeneity Effect on Unsaturated Water Flow Modeling at Meso-Scale  [PDF]
Artur Paiva Coutinho, Laurent Lassabatere, Thierry Winiarski, Jaime Joaquim da Silva Pereira Cabral, Antonio Celso Dantas Antonino, Rafael Angulo-Jaramillo
Journal of Water Resource and Protection (JWARP) , 2015, DOI: 10.4236/jwarp.2015.74028
Abstract: The understanding of unsaturated flow in heterogeneous formations is a prerequisite to the understanding of pollutant transfer in the vadose zone and the proper management of infiltration basins settled over such heterogeneous formations. This study addresses the effect of lithological heterogeneity of a glaciofluvial deposit on flow in the vadose zone underneath an infiltration basin settled in the Lyon suburbs. The basin had already been the subject of several previous studies, some of which demonstrated the impact of soil heterogeneity. But all of them were only based on the sedimentological study of a trench and no study addressed the potential spatial variability of results due to the spatial variability of soil heterogeneity. In this study, we model flow in the vadose zone for several case studies, including drainage, water infiltration during a rainfall event, and a complete meteorological chronic. These calculations were conducted for several sections, previously characterized in the basin using GPR and sedimentological study and compared with a blank (homogeneous section). The results clearly show that heterogeneity impacts unsaturated flow and that these impacts depend upon the section considered. Some geometrical architectural and textural parameters were proposed to explain the spatial variability and effect of the soil heterogeneity on unsaturated flow, thus establishing the first step towards modeling unsaturated flow in the basin at the meso-scale.
Caracteriza??o hidrodinamica de solos: aplica??o do método Beerkan
Souza, Eduardo S. de;Antonino, Antonio C. D.;Angulo-Jaramillo, Rafael;Netto, André Maciel;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2008, DOI: 10.1590/S1415-43662008000200004
Abstract: knowledge of the soil hydraulic properties, such as the water retention q(h) and hydraulic conductivity k(q) curves, is indispensable for water and pollutant transport modeling of agricultural systems. several experimental techniques have been proposed to determine these characteristic curves of the soil in the field. however, the complexity, the high costs and the time of execution of measurements are limiting factors for obtaining these characteristic curves in large areas. in this work, a simple methodology is shown, known as "beerkan", which secks to overcome these difficulties. it uses experimental data of infiltration, bulk density and the particle-size distribution for estimating the q(h) and k(q) curves. this method was applied to two soils with different textural classification (three of an oxisoil and three of an alluvial soil). for the hydrodynamic characterization, the shape and the normalization parameters of the q(h) and of k(q) curves were determined. the shape parameters depend upon the soil texture and they were obtained from the cumulative particle-size distribution curve; the normalization parameters depend on soil structure and they were obtained from the infiltration experiments using the simple ring infiltrometer. the beerkan method proved to be robust and adapted to modeling the three-dimensional infiltration in field, as well as allowing the hydrodynamic characterization of the two soils.
Distribui??o probabilística do fator de escala de dois solos do Estado da Paraíba
Antonino, Antonio C. D.;Ruiz, Carlos F.;Souza, Eduardo S. de;Netto, André M.;Angulo-Jaramillo, Rafael;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2004, DOI: 10.1590/S1415-43662004000200009
Abstract: the probabilistic distribution of the scale factor of superficial layer was determined, considering the similar fractal theory for two soils in the paraíba state. the study was performed at two experimental sites, with different climate and soil conditions of approximately 4 ha. the first was located in the várzea grande farm, in the municipality of s?o jo?o do cariri, pb (7o23's e 36o31'o). the soil was classified as fluvent. the second was located in the centro de ciências agrárias, of the ufpb, in the municipality of areia, pb (6o58's, 35o41'w). the soil was classified as oxisol. to estimate the soil saturated hydraulic conductivity, infiltration experiments were performed using a ring infiltrometer (15 cm diameter) on the soil surface, at 80 points on a regular mesh of 25 x 25 m. for both soils, the logarithms of the scale factors followed a gaussian distribution or normal distribution. the probabilistic distribution function allowed the estimation of the fractal dimension of the porous media that represent the studied soils.
Determina??o da condutividade hidráulica e da sorvidade de um solo com infiltr?metro a disco
Antonino, Antonio C. D.;Angulo-Jaramillo, Rafael;Souza, Eduardo S. de;Maciel Netto, André;Carneiro, Clemente J. G.;Montenegro, Abelardo A. A.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2001, DOI: 10.1590/S1415-43662001000200012
Abstract: hydraulic conductivity (k) and sorptivity (s) of two layers with different textural classes of a fluvents soil from flocos dams, located in tuparetama, pe, brazil were determined using the cumulative infiltration data measured with an infiltrometer disk. during the infiltration experiments, water was applied to the soil by an infiltrometer disk at potentials equivalent to 0, -3, -6 e -12 cm of water columm. three methods were used to evaluate k and s: i) van genuchten (vg); ii) russo (gr); e iii) zhang & van genuchten (zv). these methods based on the previous knowledge of the soil-moisture characteristic curve, which were obtained by the adjustment of the functions proposed by each method. the equation of cumulative infiltration described with precision the infiltration experiments, and yielded determination coefficients (r2) greater than 0.995. the method gr is the less adequate, since it systematically overestimated values and did not predict well the normalized k for the two soil layers. on the other hand, the vg method yielded good predictions of normalized k for both soil layers.
Variabilidade espacial dos parametros hidrodinamicos de duas parcelas agrícolas no estado da Paraíba
Souza, Eduardo Soares de;Antonino, Antonio Celso Dantas;Jaramillo, Rafael Angulo;Netto, Andre Maciel;Montenegro, Suzana Maria Gico Lima;Silva, Edvane Borges da;
Revista Brasileira de Ciência do Solo , 2008, DOI: 10.1590/S0100-06832008000500001
Abstract: knowledge on soil hydraulic properties such as water retention and hydraulic conductivity curves is indispensable for water and pollutant transport modeling of agricultural systems. this soil hydraulic properties are affected by numerous sources of variability, mostly associated with spatial, temporal, and management-related factors. the objective of this study was to analyze the spatial variability of parameters of water retention (van genuchten) and hydraulic conductivity (brooks & corey) curves obtained with the "beerkan" method based on simple infiltration experiments and soil texture data. these parameters are related to shape or texture (fitting parameters that shape the curves) and normalization or structure (saturated water content, saturated hydraulic conductivity and air entry potential). the field tests were carried out in a 25 x 25 m grid in a fluvent soil and in an oxisoil planted with beans (vigna unguiculata (l.) walp.). for both soils, spatial dependence was verified in the values of parameters of shape, saturated water content, logarithms of the saturated hydraulic conductivity and air entry potential. the values of saturated water content and air entry potential were more sensitive to variation at short distances in the fluvent than in the oxisoil. the spatial dependence in the variograms was weak.
Tumor de Células Cromófobas: A propósito de un caso
Fanny Angulo,Ana Castillo,Rafael Angulo
CIMEL. Ciencia e Investigación Médica Estudiantil Latinoamericana , 2007,
Abstract: El carcinoma de células renales representa más del 90% de los tumores malignos del ri ón y se observa con mayor frecuencia en varones entre la 60 a 70 a os. El carcinoma de células cromófobas representa de 5 a 8% de los carcinomas de células renales. Sus metástasis más frecuentes son a pulmón (50%) y a hueso (33%). El tratamiento de elección es la nefrectomía radical con una sobrevida en 5 a os del 45%. Presentamos el caso clínico de una paciente de 63 a os, con dolor lumbar de leve intensidad. Los estudios imagenológicos revelan tumoración en polo inferior de ri ón izquierdo de 6x6cm aproximadamente. Se realiza laparotomía exploradora y se decide nefrectomía radical. El estudio histopatológico informa carcinoma renal de células cromófobas. Se indica quimioterapia con evolución satisfactoria.
Rinosporidiosis Nasal: A propósito de un caso
Fanny Angulo,Ana Castillo,Rafael Angulo
CIMEL. Ciencia e Investigación Médica Estudiantil Latinoamericana , 2007,
Abstract: La rinosporidiosis es una enfermedad crónica granulomatosa que afecta principalmente las mucosas, predominantemente nasal y nasofaríngea, y con menos frecuencia la conjuntiva ocular y saco lacrimal. El Rhinosporidium actualmente se considera una cianobacteria Microcystis aeruginosa. La mayoría de los casos han sido reportados en la India y en Sri Lanka, afectando a jóvenes entre 20 y 40, en nuestro país se presenta con mayor incidencia en los estados Portuguesa y Barinas. Presentamos el caso de un joven de 15 a os con rinosporidiosis localizado en mucosa nasal, a quien se le hizo un estudio histológico que reportó hiperplasia de la mucosa y presencia de estructuras quísticas ocupadas por endosporas e infiltrado inflamatorio de severidad variable; el tratamiento fue la resección quirúrgica de la lesión con evolución satisfactoria.
Diferenciación genética de tres poblaciones colombianas de Triatoma dimidiata (Latreille, 1811) mediante análisis molecular del gen mitocondrial ND4 Genetic differentiation of three Colombian populations of Triatoma dimidiata (Heteroptera: Reduviidae) by ND4 mitochondrial gene molecular analysis
Nelson Grisales,Omar Triana,Víctor Angulo,Nicolás Jaramillo
Biomédica , 2010,
Abstract: Introducción. Triatoma dimidiata es el segundo vector más importante de la enfermedad de Chagas en Colombia, después de Rhodnius prolixus. El conocimiento de la composición genética y la diferenciación de poblaciones es fundamental para el adecuado dise o e implementación de estrategias de control y vigilancia vectorial. Objetivo. Determinar el nivel de variabilidad y diferenciación genética en tres poblaciones colombianas de T. dimidiata provenientes de distintas localidades y hábitats, mediante el análisis molecular de un fragmento del gen mitocondrial ND4. Materiales y métodos. Se analizó el nivel de polimorfismo y la estructura genética de dos poblaciones silvestres de los departamentos de La Guajira (n=10) y Santander (n=10), y de una población intradomiciliaria (n=15) y peridomiciliaria (n=5) del Cesar. Para tal fin, se analizaron las secuencias de nucleótidos de un fragmento del gen mitocondrial ND4. Resultados. T. dimidiata en Colombia demostró tener gran diversidad genética, tanto a nivel de nucleótidos (π: 0,034) como de haplotipo (Hd: 0,863), además de una significativa estructuración de población (fST: 0,761) con un bajo número de migrantes (Nm: 0,157). Las distancias genéticas y las diferencias en los niveles de variabilidad genética entre las tres poblaciones fueron coherentes con una posible subdivisión de población. Conclusión. Este trabajo demostró diferenciación genética entre las poblaciones de T. dimidiata de La Guajira, Cesar y Santander. Se sugiere una posible relación entre tal subdivisión y algunas características eco-epidemiológicas que posee T. dimidiata en el centro-oriente y en el norte de Colombia. Finalmente, este trabajo describe, por primera vez, la utilidad del ND4 como un marcador molecular para el estudio de poblaciones naturales de T. dimidiata. Introduction. Triatoma dimidiata is the second most important vector of Chagas disease in Colombia after Rhodnius prolixus. Population genetic studies are essential for the adequate design and implementation of vector control and surveillance strategies. Objective. The level of genetic variability and population differentiation was surveyed among three Colombian populations of T. dimidiata from different geographic locations and ecotopes, using ND4 mitochondrial gene. Materials and methods. Genetic comparison was made between two wild populations from La Guajira (n=10) and Santander (n=10) provinces, and one intra (n=15) and one peridomiciliary (n=5) population from the Cesar province. The polymorphism frequencies of the ND4 mitochondrial gene sequence were analyzed to deduce p
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