Binary Evolution and the Progenitor of SN 1987A

Since the majority of massive stars are members of binary systems, an understanding of the intricacies of binary interactions is essential for understanding the large variety of supernova types and sub-types. I therefore briefly review the basic elements of binary evolution theory and discuss how binary interactions affect the presupernova structure of massive stars and the resulting supernovae. SN 1987A was a highly anomalous supernova, almost certainly because of a previous binary interaction. The most likely scenario at present is that the progenitor was a member of a massive close binary that experienced dynamical mass transfer during its second red-supergiant phase and merged completely with its companion as a consequence. This can naturally explain the three main anomalies of SN 1987A: the blue color of the progenitor, the chemical anomalies and the complex triple-ring nebula.Comment: Proceedings for the conference "SN 1987A: Ten Years After", eds. M. M. Phillips and N. B. Suntzeff, which took place in 1997, but which still has to appear in print. Proceedings are made public as a source of historical referenc

Neutral face generator using variational autoencoders

Treballs Finals de Grau d'Enginyeria Informàtica, Facultat de Matemàtiques, Universitat de Barcelona, Any: 2020, Director: Meysam Madadi[en] The aim of this project is to develop a model which is able to generate a neutral face from a sample of images of the same person with different expressions. This expressions can be gathered from a video of that person just talking frontally to the camera. For doing this we will need a model which as it is able to learn meaningful features of the frontal faces. Also this model should be capable of reconstructing faces from this learned features

Generation of Synthetic Solar Images with GANs

This works presents an alternative solution to the already existing physical simulations for the Sun's photosphere which are used to output a single tex- ture image from the Sun's surface. This simulations are slow and require huge computational power, a cheaper alternative in time and resources is introduced. Architectures for a Generative Adversarial Network and a Variational Au- toeconder are considered and trained in the generation of small image tiles (128x128px) that resemble the surface of the Sun around an area of approxi- mately 2:62 107km2 which with the proposed method can be composed into an image of arbitrarily any size given enough tiles. Di erent architectures along with ne tuning is used to obtain the best net- work possible in both cases. Their results are compared, but the Generative Adversarial Network shows a powerful improvement on the generation of said tiles compared to the Variational Autoencoder. Lastly some methodologies for stitching together the generated tiles are pre- sented including a technique that uses a Genetic Algorithm approach to modify the generated tiles

Reglas de combinación de las componentes sísmicas en el diseño de puentes

81 páginas. Maestría en Ingeniería Estructural.En el presente trabajo se analizan tres modelos de puentes simples, para comprender su comportamiento elástico ante cargas sísmicas. Estos modelos se someten a veinte sismos registrados principalmente en la costa Pacífica Mexicana y centro del país por su alta actividad sísmica, cercanía a los epicentros y riesgo para puentes tipo carreteros. De los análisis elásticos para estas estructuras se realizan comparaciones según las diferentes propuestas de combinación de componentes sísmicos, y de acuerdo con los resultados, se constata si existen beneficios o vacíos que puedan presentarse al realizar un diseño seguro y económico de puentes. El objetivo final de este trabajo será confrontar los resultados obtenidos de manera rigurosa y compararlos con aquéllos derivados de los códigos y propuestas actuales de diseño de puentes; de acuerdo con los resultados obtenidos emitir algunas primeras recomendaciones que se espera ofrezca beneficios para el diseño de puentes. Se reconoce, sin embargo, que son necesarios más estudios que consideren otros tipos de puentes y el análisis de más señales, algunas registradas fuera de México

Ophiolites in the Eastern Cordillera of the central Peruvian Andes

A discoutinuous NNW-SSE trending belt of scattered ultraiuafic (UM) and subordínate mafic (M) rocks ís exposed alona some 250 km in the Eastern Cordillera of the peruvian Andes (Junin and Huanuco Departnients. -°"-12° S). New data questiou tlieír pieviousty assuuned [1.2] intrusive origin. Work, in progress shows tLat the essential geologic and tecronk featiires are comnion to most of them, as will t e shown on the southeniniost occurrences: Tapo and Acobaniba (Tarraa proviuce). The Tapo massif is the most conspkuoiis and the oaty one with chiomite mining history. It is a lens-shaped body, 5 km long [NV-SE direction) and 1 -2 km wide. lying on detritaí sedirnents of the Lower Carboniferous Ambo Group [3], and comprising extreniely tectomsed and serpentinised peridotiles wilh subordínate podiform chroirdtite bodies. nieta-gabbros or amphibolites The Acobamba oecurrences couiprise serpentinites aud subordínate meta-gabbros [A]. in contact with phyllites of the Precarnbnan (?) Huacar Group (Maraáón Complex)

La función reguladora del Estado: ¿qué regular y por qué? Conceptualización y el caso de Colombia

Resumen La regulación es una de las formas que tiene el Estado para intervenir en la Economía. Pero a menudo en la literatura no es claro el alcance de esta función, pues en muchos casos se restringe solo al análisis de las acciones del Estado para promover la competencia y, en otros, hace referencia a políticas para corregir cualquier fallo del mercado. El objetivo de este trabajo es hacer una revisión bibliográfica para establecer un concepto claro de regulación y estudiar la forma en que se ejerce esta forma de intervención en Colombia. Para esto, se ofrece una revisión bibliográfica que trata de responder ¿qué es la regulación? En segundo lugar, se estudian las generalidades del esquema regulatorio en Colombia; en tercer lugar se exponen dos casos de estudio en el país. Finalmente se ofrecen las conclusiones.regulación, fallos del mercado, intervención del Estado, competencia

Neoproterozoic ultramafic and mafic magmatism in the Eastern Cordillera of the central peruvian Andes: the Tapo Massif

A highly dismembered assemblage of ultramafic and mafic rocks is exposed in the Eastern Cordillera of the Central Peruvian Andes, extending along a discontinuous NW-SE belt over some 250 km between 12° and 9° S of latitude. One of the most important occurrences is the Tapo Mafic-Ultramafic Complex, which occurs at 3750 to 4200 m above sea level, 2 km to the west of Tapo locality, in the Tarma province, about 200 Km west of Lima. The Tapo complex is a lens-shaped body, 5 km long and 1-2 km wide, that consists mainly of strongly serpentinized peridotites and some gabbros. Several small open pits won chromite from podiform chromitite lenses ( ≥60 chromite) and from disseminated chromite in serpentinite. The main structural trend of the Tapo Complex is NW – SE and the massif is tectonically emplaced upon Lower Carboniferous sedimentary rocks. The rocks of the Tapo massif are overprinted by metamorphism reaching amphibolite facies (see Willner et al, 2010, for more information on the metamorphic conditions). The main purpose of this work is to constrain the age determination of the Tapo Complex, using Sm-Nd technique direct dating of chromites and, also, amphibole, plagioclase and whole-rock samples from the host gabbro. In addition K-Ar age determination on amphibole is presented to date the metamorphic overprint