Hydrodynamical simulations of massive stars collisions

openSince the detection of gravitational waves traveling through our universe, a new field of astrophysics has opened up, and with it many hypotheses and theoretical predictions have been put to the test. This is the case of the pair-instability mass gap (60 and 120 Msun. Gravitational wave signals have been detected whose primary and secondary black holes fall within the mass range where it was previously thought unthinkable that they could exist as a product of stellar evolution. Different mechanisms could explain these observations, among which the gravitational collapse of a particular type of remnant from a collision between two predecessor stars stands out. Multiple studies support this hypothesis, however, it is necessary to determine the incidence of the collision parameters on the main characteristics of the post-coalescence star, especially to corroborate that its final mass and chemical composition made it a suitable remnant to produce these special black holes. To achieve this goal, the hydrodynamic simulations of stellar collisions are a perfect tool. In this thesis, we have analyzed a set of simulations produced with the smoothed particle hydrodynamics code StarSmasher. This set explores different configurations of mass, radius, stellar evolution time, velocity at infinity and impact parameter for the two colliding stars. We have been able to analyze the temporal evolution of the percentage of unbound mass for all cases, obtaining that collisions produce a range of mass loss between 9.7 % and 19.3 %, with the impact parameter being the most influential value in the increase of this percentage. We have also visualized that the relaxation of the final remnant occurs quite quickly after the impact as long as the collision is radial. Only two days are necessary for the remnant mass to remain stable, as well as its velocity. In the case of non-radial collisions, the relaxation of the post-coalescence star is much more complex, since it is altered by successive collisions between the cores of the two primary stars. Finally, we also found that non-radial collisions are the only ones that result in a remnant with tangential rotational velocity, a fact that would favor the chemical enrichment of its constituent layers and modify its subsequent evolution.Since the detection of gravitational waves traveling through our universe, a new field of astrophysics has opened up, and with it many hypotheses and theoretical predictions have been put to the test. This is the case of the pair-instability mass gap (60 and 120 Msun. Gravitational wave signals have been detected whose primary and secondary black holes fall within the mass range where it was previously thought unthinkable that they could exist as a product of stellar evolution. Different mechanisms could explain these observations, among which the gravitational collapse of a particular type of remnant from a collision between two predecessor stars stands out. Multiple studies support this hypothesis, however, it is necessary to determine the incidence of the collision parameters on the main characteristics of the post-coalescence star, especially to corroborate that its final mass and chemical composition made it a suitable remnant to produce these special black holes. To achieve this goal, the hydrodynamic simulations of stellar collisions are a perfect tool. In this thesis, we have analyzed a set of simulations produced with the smoothed particle hydrodynamics code StarSmasher. This set explores different configurations of mass, radius, stellar evolution time, velocity at infinity and impact parameter for the two colliding stars. We have been able to analyze the temporal evolution of the percentage of unbound mass for all cases, obtaining that collisions produce a range of mass loss between 9.7 % and 19.3 %, with the impact parameter being the most influential value in the increase of this percentage. We have also visualized that the relaxation of the final remnant occurs quite quickly after the impact as long as the collision is radial. Only two days are necessary for the remnant mass to remain stable, as well as its velocity. In the case of non-radial collisions, the relaxation of the post-coalescence star is much more complex, since it is altered by successive collisions between the cores of the two primary stars. Finally, we also found that non-radial collisions are the only ones that result in a remnant with tangential rotational velocity, a fact that would favor the chemical enrichment of its constituent layers and modify its subsequent evolution

Mejora en la distribución de áreas y equipos en el proceso de introducción y práctica en la especialidad de mecánica automotriz, del SENATI Callao Ventanilla

El autor no autorizó la publicación de la tesis

Use of 3D models as a didactic resource in archaeology. A case study analysis

The generation of 3D models through Terrestrial Laser Scanning has proved to be valuable tools for the study, documentation and recreation of archaeological remains. In this context, it is described how to generate a physical model to provide not only to researchers, but also as teaching material for teachers for university students, facilitating their access and study. As a practical case, this article describes the acquisition, processing and management of archaeological data in the archaeological site of Cástulo, Jaén, in South Spain. We expound how to get the 3D-printed model of the Muslim tower, showing how it is possible to generate a scale and very reliable reproduction of the structure, being also an useful and tangible material in the teaching of cultural heritage

¿Por qué la energía solar rompió récords en 2017?

"La energía solar, más que cualquier otra fuente renovable, ha impulsado el crecimiento de las formas alternativas de generación de energía en el mundo. Una de las causas, según explica Carlos Arredondo, investigador del programa de ingeniería en energía de la Universidad de Medellín, es ""un aumento en la demanda de energía solar en los últimos años que, junto con la innovación tecnológica, ha permitido la reducción de los costos de producción de energía solar"".

Autonomía de los menores en Colombia, una de las mayo

El 9 marzo del 2017, un joven colombiano de 13 años murió luego de padecer durante toda su vida parálisis cerebral y epilepsia. Sus padres llevaban un año pidiendo que se le practicara la eutanasia, pero su petición fue rechazada por tratarse de un menor de edad. (Mención: Universidad de Medellín)

Metodología para calcular requisitos de participación en contratos públicos de vías

El presente trabajo busca dar una breve explicación de en qué consiste la contratación estatal y que leyes la regulan. Una vez claro las fases de una contratación se mostrarán y analizaran en paralelo varios procesos de contratación de proyectos viales en el Departamento de Antioquia con objetos similares pero con diferencias enormes en los criterios de selección. Es una propuesta metodológica para definir los requisitos de participación en procesos de contratación pública suyo objeto principal incluye actividades de construcción o mantenimiento de vías

Metodología de priorización de servicios urbanos en ciudades intermedias. Aporte a la sostenibilidad urbana

Para facilitar la toma de decisiones a nivel territorial, se deben generar estrategias integrales que relacionen tanto la capacidad que tienen los ecosistemas para suplir las demandas de la ciudad, así como los servicios que ofrece al conjunto de población. En ese sentido en el presente trabajo de grado se formuló una metodología como aporte a la gestión ambiental territorial, la cual permite orientar la toma de decisiones en la planificación de servicios urbanos de ciudades intermedias, en base a la función socioeconómica predominante de la misma, direccionando el territorio a escenarios de sostenibilidad urbana. Por lo tanto se caracterizaron los servicios urbanos determinantes de la sostenibilidad urbana; se definieron criterios que permitieron estructurar la metodología los cuales están asociados a las funciones ecosistémicas que abarcan los servicios urbanos demandados por la función socioeconómica predominantes, se validó la metodología en el municipio de Pereira, encontrando la función predominante de la misma y los servicios urbanos prioritarios sobre los que se debe hacer gestión ambiental para aportar a la sostenibilidad urbana de la ciudad. El fin último es identificar hacia donde se debe dirigir la gestión ambiental de ciudades intermedias.To ease decision-making processes at a territorial level, integral strategies that relate both the ecosystems capacity to supply the demand of the city and the services to the population have to be generated. In that sense, in the present thesis a methodology as an input to the territorial environmental management was formulated. This methodology enables to guide the decision-making in the planning of urban services in intermediate cities, based on the prevailing socioeconomic function of them. Directing the territory towards urban sustainability scenarios. Hence, the determinant urban services for the urban sustainability were characterized. There were defined the criteria that enable to structure the methodology. These criteria are associated to the ecosystemic functions that cover the demanded urban services by the prevailing socioeconomic function. The methodology was validated in the municipality of Pereira, finding its prevailing function, as well as the priority urban services upon which environmental management must be implemented in order to contribute to the urban sustainability of the city. The ultimate aim is to identify where the environmental management of intermediate cities must be oriented

Ecuaciones diferenciales del c?lculo de variaciones

46 p. Recurso Electr?nic

Juan Manuel Aria a Juan Facundo Quiroga

Comunicando el vencimiento del plazo para la entrega de las monedas Güemes. Señala que no se ha presentado nadie a devolverlas. Evitará que se burle la disposició

Significados de Felicidad en Narrativas de Ciudadanos de Manizales, Caldas

Maestría en Desarrollo Sostenible y Medio Ambiente, Facultad de Ciencias Contables, Económicas y Administrativas.La investigación "significados de felicidad en ciudadanos de Manizales, Caldas" aborda la problemática de una sociedad que busca su felicidad al rededor de las premisas del capitalismo. El consumismo y la acumulación de bienes materiales enmarcan conductas e imaginarios colectivos donde le ser humano pretende ser feliz, no obstante, la naturaleza del mismo, abordada desde una perspectiva moral-filosófica como el Utilitarismo de John Stuart Mill, plantea la posibilidad de encontrar en los placeres más sublimes una alternativa para rescatar la sensibilidad de las personas hacía los demás en aras de alcanzar una felicidad colectiva. En tanto que, la Filosofía Hermenéutica de Hans-Georg Gadamer, permite soportar teórica y metodológicamente el entramado de la felicidad en los ciudadanos de Manizales Caldas para el año 2018 desde sus significados, donde el interpretar, comprender y dotar de sentido a una realidad oculta en los textos productos de las narrativas de los ciudadanos, se convierte en el desenlace de este trabajo investigativo