Active flow control of flow past SD7003 airfoil with synthetic Jets at Re=60000

Active Flow Control (AFC) can improve markedly the aerodynamic capabilities of airfoils. Focusing on one of its strategies employing Synthetic Jet Actuators (SJA), the present bachelor thesis studied the performance of two synthetic jet configuration implementations via an unsteady Reynolds-Averaged Navier-Stokes (RANS) solver using three different turbulence models. The mesh employed to conduct the different studies consisted of a hybrid C-type grid which was developed via a hand-made python program. The airfoil considered was the Selig-Donovan 7003 (SD7003) in a post-stall angle of attack $\alpha=14\degree$ at Reynolds number $Re=6\cdot 10^4$. One of the first findings of the study was that two of the three selected turbulence models, concretely $realizable-k-\epsilon$ and $SST-k-\omega$, failed to solve correctly the flow in the post-stall conditions of the baseline case. From that point on, only the Spalart-Allmaras model was used to conduct the following actuated studies. To ensure the veracity of the results obtained from the different baseline and actuated cases, they were compared to the available literature whenever possible. The first study addressed the sensitivity of the Spalart-Allmaras results on the boundary condition value chosen for the turbulent viscosity. Results concluded that a notable influence was present and that the value that produced the most accurate results when compared to LES ones from literature was $\tilde{\nu}/\nu = 10^{-5}$. Next, a study addressing the performance of a tangential jet implementation for AFC purposes was conducted by testing six different combinations of SJA parameters. From the obtained results was concluded that the non-dimensional frequency $F^+$ played a vital role in the stability of the velocity field within the boundary layer in this jet configuration. In addition, the study showed promising results as six mere combinations of different SJA parameters were already able of providing outstanding improvements on both the lift and aerodynamic efficiency of the airfoil

Glory revealed in disk-integrated photometry of Venus

Context. Reflected light from a spatially unresolved planet yields unique insight into the overall optical properties of the planet cover. Glories are optical phenomena caused by light that is backscattered within spherical droplets following a narrow distribution of sizes; they are well known on Earth as localised features above liquid clouds. Aims. Here we report the first evidence for a glory in the disk-integrated photometry of Venus and, in turn, of any planet. Methods. We used previously published phase curves of the planet that were reproduced over the full range of phase angles with model predictions based on a realistic description of the Venus atmosphere. We assumed that the optical properties of the planet as a whole can be described by a uniform and stable cloud cover, an assumption that agrees well with observational evidence. Results. We specifically show that the measured phase curves mimic the scattering properties of the Venus upper-cloud micron-sized aerosols, also at the small phase angles at which the glory occurs, and that the glory contrast is consistent with what is expected after multiple scattering of photons. In the optical, the planet appears to be brighter at phase angles of 11-13 deg than at full illumination; it undergoes a maximum dimming of up to 10 percent at phases in between. Conclusions. Glories might potentially indicate spherical droplets and, thus, extant liquid clouds in the atmospheres of exoplanets. A prospective detection will require exquisite photometry at the small planet-star separations of the glory phase angles.Comment: In press. Astronomy & Astrophysics. Letter to the Editor; 201

Online advertising: analysis of privacy threats and protection approaches

Online advertising, the pillar of the “free” content on the Web, has revolutionized the marketing business in recent years by creating a myriad of new opportunities for advertisers to reach potential customers. The current advertising model builds upon an intricate infrastructure composed of a variety of intermediary entities and technologies whose main aim is to deliver personalized ads. For this purpose, a wealth of user data is collected, aggregated, processed and traded behind the scenes at an unprecedented rate. Despite the enormous value of online advertising, however, the intrusiveness and ubiquity of these practices prompt serious privacy concerns. This article surveys the online advertising infrastructure and its supporting technologies, and presents a thorough overview of the underlying privacy risks and the solutions that may mitigate them. We first analyze the threats and potential privacy attackers in this scenario of online advertising. In particular, we examine the main components of the advertising infrastructure in terms of tracking capabilities, data collection, aggregation level and privacy risk, and overview the tracking and data-sharing technologies employed by these components. Then, we conduct a comprehensive survey of the most relevant privacy mechanisms, and classify and compare them on the basis of their privacy guarantees and impact on the Web.Peer ReviewedPostprint (author's final draft

Interstitial Cells of Cajal and Enteric Nervous System in Gastrointestinal and Neurological Pathology, Relation to Oxidative Stress

The enteric nervous system (ENS) is organized into two plexuses—submucosal and myenteric—which regulate smooth muscle contraction, secretion, and blood flow along the gastrointestinal tract under the influence of the rest of the autonomic nervous system (ANS). Interstitial cells of Cajal (ICCs) are mainly located in the submucosa between the two muscle layers and at the intramuscular level. They communicate with neurons of the enteric nerve plexuses and smooth muscle fibers and generate slow waves that contribute to the control of gastrointestinal motility. They are also involved in enteric neurotransmission and exhibit mechanoreceptor activity. A close relationship appears to exist between oxidative stress and gastrointestinal diseases, in which ICCs can play a prominent role. Thus, gastrointestinal motility disorders in patients with neurological diseases may have a common ENS and central nervous system (CNS) nexus. In fact, the deleterious effects of free radicals could affect the fine interactions between ICCs and the ENS, as well as between the ENS and the CNS. In this review, we discuss possible disturbances in enteric neurotransmission and ICC function that may cause anomalous motility in the gut

Plan de comercialización "Sabor y Delicias"

Sabor y Delicias es una empresa conformada por un grupo de mujeres emprendedoras, todas ellas cabeza de hogar, auspiciadas por la Alcaldía de Medellín y EAFIT Social -- El presente trabajo está orientado a responder a la necesidad que tiene Sabor y Delicias de incrementar su volumen de ventas, de manera que le permita mejorar su cobertura de mercado, incrementar su nivel de ingresos y garantizar sus utilidades en el presente -- Para cumplir con el objetivo planteado, se elaboró un plan simple pero con una propuesta efectiva; este plan parte de la generación de dos objetivos, cada uno con sus correspondientes iniciativas estratégicas y tácticas -- En el desarrollo del plan se entrevistó al grupo de emprendedoras se hicieron recomendaciones y se analizó la situación actual del negocio -- En este cometido se recopiló información acerca de Sabor y Delicias, se realizó un análisis DOFA, que permitió definir las iniciativas estratégicas presentadas y, con base en ellas, se recomiendan los respectivos indicadores que permitan retroalimentar la gestión del plan de mercadeo propuesto -- Los objetivos planteados están orientados a lograr un incremento en el volumen de ventas del negocio, el primero busca incrementar el número de clientes y el segundo está dirigido a mejorar la oferta de productos existente, que, como se mencionó arriba, cuenta con las estrategias y tácticas diseñadas para llevarlo a cabo -- Este trabajo se presentará a dicha empresa con el fin de que pueda implementar estas acciones y mejorar sus ingreso

Formulación de estrategias a partir de la Investigación Acción Participativa (IAP), para el fortalecimiento de la ciudadanía ambiental en la Vereda el Rosal, Corregimiento de la Gallera, Municipio del Tambo, Cauca.

Imagenes, graficos,diagramas, Infografia.La Vereda el Rosal, se ubica en el corregimiento de la Gallera, Municipio del Tambo, Departamento del Cauca, caracterizada por su abundancia natural, en este contexto el problema principal se centra en la frágil ciudadanía ambiental en la comunidad, implicando que la población en su deber no asume la responsabilidad de preservar las riquezas naturales de la localidad, afectando indiscriminadamente la flora y fauna en gran parte endémica de la localidad, y como derecho el territorio se ve excluido en la participación de las políticas públicas que permitan el desarrollo, social, económico y ambiental de la región. De allí la importancia desde el punto de vista sociológico de fortalecer la ciudadanía ambiental de la comunidad, teniendo como fundamento la aplicación de la investigación acción participativa. El proyecto aplicado pretende entonces responder: ¿Qué estrategias serian pertinentes para el fortalecimiento de la ciudadanía ambiental, en la Vereda el Rosal, Corregimiento de la Gallera, Municipio de El Tambo, Cauca? El Objetivo general es: Plantear estrategias que permitan fortalecer la ciudadanía ambiental en la Vereda el Rosal, Corregimiento la Gallera Municipio Tambo Cauca. El proyecto aplicado demuestra que en los hallazgos investigativos, a partir de la IAP, existe una fragilidad respecto al tema de la ciudadanía ambiental en la vereda el Rosal, y es necesario la aplicación de estrategias para su fortalecimiento.The Vereda el Rosal is located in the district of Gallera, Municipality of Tambo, Department of Cauca, characterized by its natural abundance. In this context, the main problem focuses on the fragile environmental citizenship in the community, implying that the population in its duty does not assume the responsibility of preserving the natural wealth of the locality, indiscriminately affecting the flora and fauna, a large part of which is endemic to the locality, and as a right the territory is excluded from the participation of public policies that allow development, social, economic and environmental of the region. Hence the importance from the sociological point of view of strengthening the environmental citizenship of the community, based on the application of participatory action research. The applied project then intends to answer: What strategies would be relevant for the strengthening of environmental citizenship, in the Vereda el Rosal, Corregimiento de la Gallera, Municipality of El Tambo, Cauca? The general objective is: To propose strategies that allow strengthening environmental citizenship in the Vereda el Rosal, Corregimiento la Gallera Municipality of Tambo Cauca. The applied project shows that in the investigative findings, from the IAP, there is a fragility regarding the issue of environmental citizenship in the village of El Rosal, and the application of strategies for its strengthening is necessary

Herramientas tecnológicas en la práctica profesional de estudiantes técnicos de enfermería de un instituto de Lima Norte – 2022

El trabajo de investigación tuvo como título: Herramientas tecnológicas en la práctica profesional de estudiantes técnicos de enfermería de un Instituto de Lima Norte – 2022, cuyo propósito fue determinar de qué manera las Herramientas tecnológicas influyen en la práctica profesional de estudiantes técnicos de enfermería, sustentada en una metodología de tipo básico, de diseño no experimental transversal, enfoque cuantitativo, con muestra de estudio a 56 estudiantes del V ciclo. Los resultados conforme a la prueba de contraste de la razón de verosimilitud indicaron que el modelo logístico es significativo con un Chi cuadrado de 4,096 con valor de significancia de 0,132, siendo valor inferior al α de 0,05, determinado que las herramientas digitales influyen significativamente en la práctica profesional. La conclusión conforme a la prueba de contraste de la razón de verosimilitud indicó que el modelo logístico es significativo con un Chi cuadrado de 4,096 y un valor de significancia de 0,132, siendo un valor inferior al α de 0,05, determinado que las herramientas digitales influyen significativamente en la práctica profesional, siendo alta, obteniéndose un valor de < 0,05 la cual rechaza la H0, aceptando la Hi alterna. influyen significativamente en la práctica profesional de los estudiantes técnicos de enfermería

Soil moisture dynamics in water- and energy-limited ecosystems. Application to slope stability

I investigate the daily dynamics of the soil-water-climate system in water- and energy-limited environments. I analyze the stochastic component of radiation at the Earth's surface in the photosynthetically active spectral band in 28 sites located around the world and propose a clear-sky based methodology to model it. In order to study the e_ect of stochastic radiation on soil moisture and evapotranspiration, we use the proposed radiation model and the ecohydrological model of Rodr__guez-Iturbe et al. I introduce a semi-analytical equation to analyze the dynamics of evapotranspiration as a function of stochastic rainfall and radiation. With climatic and physiological measurements from the FLUXNET dataset, and taking into account the coupling of water and CO2 uxes through the leaf plant, I parameterize the link of transpiration and available energy, which is used to extend the ecohydrological model to energy-limited ecosystems. Finally, I carry out an application to landslides triggered by rainfall, relating the factor of safety of a slope to soil moisture, and examine the widely used threshold rainfall approach to estimate the landslides occurrence.Resumen: En esta tesis se investiga la dinámica diaria del agua en el sistema clima-suelo-vegetación en ambientes limitados por agua y energía. Se analiza la componente estocástica de la radiación fotosintéticamente activa en superficie en 28 sitios localizados alrededor del mundo, y se propone una metodóloga basada en el índice clear-sky para modelar su comportamiento. Con el modelo de radiación se estudia el efecto de la estocasticidad de la energía disponible en la dinámica de la humedad del suelo y de la evapotranspiración, proponiendo una ecuación semianalitica para modelar la transpiración en función de la lluvia y la radiación estocásticas. Usando mediciones de diferentes variables climáticas y fisiológicas, y considerando el acoplamiento de los flujos de agua y CO2 a través de la planta, se parametriza la relación entre la transpiración y la energía disponible, y se extiende el modelo ecohidrolóogico de Rodríguez-Iturbe et al. a ecosistemas limitados por energía. Por _último, se hace una aplicación a deslizamientos detonados por lluvias, relacionando el factor de seguridad de una ladera con la humedad del suelo, y se examina el enfoque de umbrales de lluvia en la determinación de la ocurrencia de deslizamientos.Doctorad

Estudio agroeconómico del cultivo de la caña de azúcar en la parte sur-occidental de la zona cafetera de Nariño.

Caña de azúcar-Saccharum officinarumMaestría en CienciasMaestrí